RU2744881C2 - Electrode for electrolysis, layered product, winding, electrolyser, method for manufacturing electrolyser, method for renewing the electrode, method for renewing layered products and method for manufacturing the electrolyser - Google Patents

Abstract

FIELD: electrolysis.

SUBSTANCE: invention relates to two variants of a layered product for electrolysis. According to one embodiment, the article comprises: an electrolysis electrode, a membrane or a supply conductor in contact with an electrolysis electrode, and a liquid enclosed between the electrolysis electrode and a membrane or a supply conductor, wherein the liquid allows the electrolysis electrode and the membrane or supply conductor to adhere with each other due to adhesion and has a surface tension of 20 mN / m to 80 mN / m.

EFFECT: proposed invention simplifies the work when the operation of a new electrolyzer begins or a worn-out electrode is renewed in it.

29 cl, 7 ex, 7 tbl, 122 dwg

Description

The technical field to which the invention relates

[0001] The present invention relates to an electrode for electrolysis, a laminated article, a winding, an electrolyzer, a method for manufacturing an electrolyzer, a method for renewing an electrode, a method for renewing a laminated article, and a method for making a winding.

Background of the invention

[0002] For the electrolysis of an aqueous solution of an alkali metal chloride, such as a salt solution, and the electrolysis of water, methods have been used using an electrolytic cell including a membrane, more specifically, an ion exchange membrane or a microporous membrane. In many cases, this electrolyzer contains a plurality of electrolytic cells connected in series therein. For electrolysis, a membrane is placed between each of the electrolytic cells. In the electrolytic cell, the cathode chamber, including the cathode, and the anode chamber, including the anode, are located close to each other, with a dividing wall (back plate) installed between them or pressed by pressing on a press, tightened by bolts or the like. Now, each anode and cathode for use in these cells is attached to the anode compartment or cathode compartment of the electrolytic cell in a manner such as welding or creasing / rolling, and then stored or transported to consumers. Meanwhile, each membrane is stored or transported to consumers in a state in which it is wrapped once around a vinyl chloride (VC) pipe. Each consumer places an electrolytic cell on the electrolytic cell frame and places a membrane between the electrolytic cells, assembling the cell. Thus, electrolytic cells are manufactured and the electrolyser is assembled by each consumer. Each of Patent Documents 1 and 2 discloses a structure formed by combining a membrane and an electrode into a structure applicable to such an electrolyzer.

List of links

Patent Literature

[0003] Patent Document 1: Japanese Patent Laid-Open No. 58-048686

Patent Document 2: Japanese Patent Laid-Open No. 55-148775

The essence of the invention

Technical problem

[0004] When the electrolysis process starts and continues, each part wears out and the performance of the electrolysis (electrolytic process) decreases due to various factors, and each part is replaced at a certain point in time. The membrane can be easily renewed by removing it from the electrolytic cell and inserting a new membrane. On the contrary, the anode and the cathode are fixed in the electrolytic cell, and thus there is the problem of the need for an extremely complex work to renew the electrode, in which the electrolytic cell is removed from the electrolyzer and transferred to a designated repair facility, fasteners such as welded ones are removed, and the old electrode is dismantled, then a new electrode is placed and secured in a manner such as welding, and the cell is transferred to the electrolysis plant and placed back into the electrolyzer. It is considered here that the above-described upgrade uses a structure formed by combining a membrane and an electrode by thermal compression described in Patent Documents 1 and 2, but a structure that can be fabricated relatively easily on a laboratory scale is not easily fabricated to fit an actual electrolytic cell. commercially available size (e.g. 1.5 m long, 3 m wide). Moreover, the characteristics of the electrolytic process (such as electrolysis voltage, current efficiency and total salt concentration in caustic soda) and service life are extremely poor, and chlorine gas and hydrogen gas are generated at the membrane-mated electrode. Thus, when used in electrolysis for a long period of time, complete delamination occurs, and the structure can hardly be used. The present invention has been made in view of the above problems in the prior art, and is intended to provide an electrolysis electrode, laminated product, winding, electrolyzer, electrolytic cell manufacturing method, electrode renewal method, laminated article renewal method, and winding production method described below.

(First target)

[0005] An object of the present invention is to provide an electrolysis electrode, laminated article, and winding that facilitates transport and handling, greatly simplifies work when a new electrolysis cell is started or a worn electrode is renewed, and in addition can also maintain or improve the operating parameters of the electrolytic process.

(Second target)

[0006] An object of the present invention is to provide a laminated article that can improve operational efficiency during the renewal of an electrode in an electrolytic cell, and furthermore, can exhibit excellent electrolytic performance also after renewal.

(Third goal)

[0007] An object of the present invention is to provide a laminated article that can improve operating efficiency during the renewal of an electrode in an electrolytic cell, and furthermore, can exhibit excellent electrolytic performance also after renewal, from a position other than the above-described second object.

(Fourth goal)

[0008] A fourth object of the present invention is to provide an electrolytic cell, a method for manufacturing an electrolytic cell, and a method for updating a laminated article, which provide excellent performance in the electrolytic process and can also prevent membrane damage.

(Fifth goal)

[0009] An object of the present invention is to provide a method for manufacturing an electrolytic cell, a method for renewing an electrode, and a method for making a winding, which can improve the efficiency during the renewal of an electrode in the cell.

(Sixth goal)

[0010] An object of the present invention is to provide a method for manufacturing an electrolytic cell that can improve operating efficiency during the renewal of an electrode in an electrolytic cell from a position other than the fifth object described above.

(Seventh goal)

[0011] An object of the present invention is to provide a method for manufacturing an electrolytic cell that can improve operational efficiency during the renewal of an electrode in an electrolytic cell from a position other than the fifth and sixth objectives described above.

Solution to the problem

[0012] As a result of intensive research carried out by the present inventors to achieve the first object, an electrolysis electrode has been obtained that has a low mass per unit area and can be connected to a membrane such that an ion exchange membrane and a microporous membrane or a worn electrode facilitate transportation. and carrying out loading and unloading with less effort, can greatly simplify the operation when a new electrolytic cell is started up or a worn electrode is renewed, and further can markedly improve performance over that of the prior art electrolytic process. In addition, the inventors of the present invention have found that performance can be equivalent to or better than the electrolysis performance of a conventional electrolytic cell, for which refurbishment work is difficult, thereby completing the present invention. Thus, the present invention comprises the following.

[1] An electrolysis electrode having a mass per unit area of 48 mg / cm ² or less and a force applied per unit mass · unit area of 0.08 N / (mg · cm ² ) or more.

[2] An electrolysis electrode according to [1], comprising an electrolysis electrode substrate having a thickness of 300 µm or less and a catalyst layer.

[3] Electrolysis electrode according to [1] or [2], in which the proportion measured by the following method (3) is 75% or more:

[Method (3)]

a membrane (square with a side of 170 mm), which is obtained by depositing particles of inorganic material and a binder on both surfaces of a membrane made of a perfluorocarbon polymer into which an ion-exchange group is introduced, and an electrode sample for electrolysis (square with a side of 130 mm) are layered in this order; and the laminated product is placed on the curved surface of the polyethylene pipe (outer diameter: 145 mm) so that the electrode sample for electrolysis in this laminated product is positioned externally under a temperature of 23 ± 2 ° C and a relative humidity of 30 ± 5%, the laminated product and the pipe in sufficiently immersed in clean water, remove excess water deposited on the surface of the laminate and the pipe, and then, one minute after this removal, measure the area fraction (%) of the area where the electrode sample for electrolysis is in close contact with the membrane, obtained by applying particles of inorganic material and a binder on both surfaces of the membrane made of perfluorocarbon polymer, into which an ion-exchange group is introduced.

[4] An electrolysis electrode according to any one of [1] to [3], wherein the electrolysis electrode has a porous structure and an open porosity ratio of 5 to 90%.

[5] An electrolysis electrode according to any one of [1] to [4], the electrolysis electrode having a porous structure and an open porosity ratio of 10 to 80%.

[6] An electrolysis electrode according to any one of [1] to [5], the electrolysis electrode having a thickness of 315 µm or less.

[7] An electrolysis electrode according to any one of [1] to [6], wherein the value obtained by measuring the electrolysis electrode by the following method (A) is 40 mm or less:

[Method (A)]

At a temperature of 23 ± 2 ° C and a relative humidity of 30 ± 5%, a sample obtained by layering an ion exchange membrane and an electrolysis electrode is wound around and fixed on the curved surface of a sleeve made of polyvinyl chloride with an outer diameter of ∅ 32 mm and allowed to stand within 6 hours; thereafter, when the electrolysis electrode is separated from the sample and placed on the flat plate, the heights L ₁ and L ₂ in the vertical direction at both edges of the electrolysis electrode are measured, and their average value is used as the measurement value.

[8] An electrolysis electrode according to any one of [1] to [7], wherein the ventilation resistance measured at a temperature of 24 ° C, a relative humidity of 32%, a piston speed of 0.2 cm / s and a ventilation volume of 0.4 cm ³ / cm ² / s is 24 kPa · s / m or less when the electrolysis electrode has a size of 50 mm × 50 mm.

[9] An electrode for electrolysis according to any one of items [1] to [8], wherein the electrode comprises at least one member selected from nickel (Ni) and titanium (Ti).

[10] A laminated article containing an electrode for electrolysis according to any one of items [1] to [9].

[11] A winding comprising an electrolysis electrode according to any one of items [1] to [9] or a laminated article according to item [10].

[0013] As a result of intensive research aimed at achieving the second objective, the inventors of the present invention have found that a laminated article that contains an electrode connected to a membrane such as an ion exchange membrane and a microporous membrane and a supply conductor such as a worn-out existing electrode, facilitates transportation and handling with less effort, can significantly simplify operation when a new electrolyzer starts to operate or a worn electrode is renewed, and, moreover, can markedly improve electrolysis productivity, thereby completing the present invention.

Thus, the present invention comprises the following aspects.

[2–1] Laminated article containing:

electrolysis electrode and

membrane or supply conductor in contact with the electrolysis electrode,

moreover, the force applied per unit mass · unit area of the electrode for electrolysis on the membrane or supply conductor is less than 1.5 N / (mg · cm ² ).

[2–2] A laminated article according to [2–1], wherein the force applied per unit mass · unit area of the electrolysis electrode on the membrane or supply conductor is more than 0.005 N / (mg · cm ² ).

[2–3] A laminated product according to [2–1] or [2–2], wherein the supply conductor is a wire mesh, metal nonwoven fabric, perforated metal sheet, expanded metal sheet or porous metal.

[2-4] A layered article according to any one of paragraphs [2-1] to [2-3], containing, as at least one surface layer of the membrane, a layer containing a mixture of particles of hydrophilic oxide and polymer, which introduced ion-exchange groups ...

[2-5] A laminated article according to any one of [2-1] to [2-4], wherein a liquid is disposed between the electrolysis electrode and the membrane or supply conductor.

[0014] As a result of intensive research aimed at achieving the third object, the present inventors have found that the above-described problems can be solved by a laminated article in which a membrane and an electrolysis electrode are partially fixed, thereby completing the present invention.

Thus, the present invention comprises the following aspects.

[3–1] Laminated article containing:

membrane and

an electrolysis electrode attached to at least one portion of the membrane surface,

moreover, the proportion of this area of the membrane surface is more than 0% and less than 93%.

[3-2] A layered article according to [3-1], wherein the electrolysis electrode contains at least one catalytic component selected from the group consisting of Ru, Rh, Pd, Ir, Pt, Au, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Ag, Ta, W, Re, Os, Al, In, Sn, Sb, Ga, Ge, B, C, N, O, Si, P, S, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb and Dy.

[3–3] A laminated article according to item [3–1] or [3–2], in which at least a portion of the electrolysis electrode penetrates the membrane and is thereby fixed to said portion.

[3-4] The laminated article according to any one of items [3-1] to [3-3], in which at least a part of the electrode for electrolysis is located inside the membrane and thereby is fixed on the said portion.

[3-5] The laminated article according to any one of items [3-1] to [3-4], further comprising a fastener for securing the membrane and the electrode for electrolysis.

[3-6] The laminated article according to [3-5], in which at least a portion of the fastener grips the membrane and the electrolysis electrode from the outside.

[3-7] A laminated article according to [3-5] or [3-6], wherein at least a portion of the fastener secures the membrane and the electrolysis electrode with magnetic force.

[3-8] A laminated product according to any one of paragraphs [3-1] - [3-7], in which

the membrane contains an ion exchange membrane containing a surface layer comprising an organic resin, and

organic resin is present at the said site.

[3-9] A laminated article according to any one of [3-1] to [3-8], wherein the membrane comprises a first ion exchange resin layer and a second ion exchange resin layer having an ion exchange capacity (EW) value different from the EW layer of the first ion exchange resin.

[3-10] A laminated article according to any one of [3-1] to [3-8], wherein the membrane comprises a first ion exchange resin layer and a second ion exchange resin layer having a functional group different from that of the first ion exchange resin layer.

[0015] As a result of intensive research aimed at achieving the fourth objective, the inventors of the present invention have found that the above-described problems can be solved by interposing at least a portion of a laminated membrane article and an electrolysis electrode between the anode side seal and the cathode side seal, thus thus completing the present invention.

Thus, the present invention comprises the following aspects.

[4–1] An electrolyzer containing:

anode,

an anode frame that holds the anode,

anode side seal, which is placed on the anode frame,

the cathode, which is opposite the anode,

a cathode frame that holds the cathode,

a cathode side seal that is located on the cathode frame and is opposite the anode side seal, and

a laminated product of a membrane and an electrode for electrolysis, placed between the anode side seal and the cathode side seal,

wherein at least a portion of the laminate is sandwiched between the anode side seal and the cathode side seal, and

the ventilation resistance, measured at a temperature of 24 ° C, a relative humidity of 32%, a piston speed of 0.2 cm / s and a ventilation volume of 0.4 cm ³ / cm ² / s, is 24 kPa s / m or less when the electrode for electrolysis has a size of 50 mm × 50 mm.

[4-2] An electrolyzer according to [4-1], in which the electrode for electrolysis has a thickness of 315 µm or less.

[4–3] Cell according to [4–1] or [4–2], where the value obtained by measuring the electrolysis electrode using method (A) below is 40 mm or less:

[4 – Method (A)] At 23 ± 2 ° C and 30 ± 5% relative humidity, a sample obtained by layering an ion exchange membrane and an electrolysis electrode is wound around and secured to the curved surface of a PVC sleeve having an outer diameter ∅ 32 mm, and leave standing for 6 hours; thereafter, when the electrolysis electrode is separated from the sample and placed on the flat plate, the heights L1 and L2 in the vertical direction at both edges of the electrolysis electrode are measured, and their average value is used as the measurement value.

[4-4] An electrolyzer according to any one of [4-1] to [4-3], wherein the mass per unit area of the electrolysis electrode is 48 mg / cm ² or less.

[4-5] An electrolyzer according to any one of [4-1] to [4-4], wherein the force applied per unit mass · unit area of the electrode for electrolysis is more than 0.005 N / (mg · cm ² ).

[4-6] An electrolyzer according to any one of [4-1] to [4-5], wherein the outermost perimeter of the laminate is further outward than the outermost perimeter of each of the anode side seal and the cathode side seal towards the conductive surface ...

[4-7] An electrolyzer according to any one of [4-1] to [4-6], wherein the electrolysis electrode contains at least one catalytic component selected from the group consisting of Ru, Rh, Pd, Ir, Pt , Au, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Ag, Ta, W, Re, Os, Al, In, Sn, Sb, Ga, Ge , B, C, N, O, Si, P, S, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb and Dy.

[4-8] An electrolyzer according to any one of [4-1] to [4-7], wherein at least a portion of the electrolysis electrode penetrates the membrane and is thereby fixed in the laminated article.

[4-9] An electrolyzer according to any one of [4-1] to [4-7], wherein at least a portion of the electrolysis electrode is located inside the membrane and thereby fixed in the laminated article.

[4-10] An electrolyzer according to any one of [4-1] to [4-9], wherein the laminated article further comprises a fastener for securing a membrane and an electrolysis electrode.

[4-11] An electrolytic cell according to [4-10], wherein in the laminated article at least a portion of the fastener penetrates the membrane and the electrolysis electrode and thereby fixes them.

[4–12] An electrolyzer according to [4–10] or [4–11], in which the fastener contains a soluble material in the laminated article that dissolves in the electrolyte solution.

[4-13] An electrolytic cell according to any one of [4-10] to [4-12], wherein in the laminated article, at least a portion of the fastener grips the membrane and the electrolysis electrode from the outside.

[4-14] An electrolytic cell according to any one of [4-10] to [4-13], wherein in the laminated article at least a portion of the fastener secures the membrane and the electrolysis electrode by magnetic force.

[4-15] An electrolyzer according to any one of paragraphs [4-1] - [4-14], in which

the membrane contains an ion exchange membrane containing a surface layer comprising an organic resin, and

the electrolysis electrode is attached with organic resin.

[4-16] The cell according to any one of [4-1] to [4-15], wherein the membrane comprises a first ion exchange resin layer and a second ion exchange resin layer having an EW value different from the EW of the first ion exchange resin layer.

[4-17] A method for manufacturing an electrolytic cell according to any one of paragraphs [4-1] - [4-16], including:

the step of laying the laminate between the anode side seal and the cathode side seal.

[4-18] A method for updating a layered product in an electrolytic cell according to any one of paragraphs [4-1] - [4-16], including:

a step of separating the laminated article from the anode side seal and sealing the cathode side thereby removing the laminated article from the electrolyzer, and

the step of laying a new laminate between the anode side seal and the cathode side seal.

[0016] As a result of intensive research aimed at achieving the fifth objective, the inventors of the present invention found that the above-described problems can be solved by using an electrolysis electrode or a laminated article of an electrolysis electrode and a new membrane in the form of a coil, thereby completing the present invention ...

Thus, the present invention comprises the following aspects.

[5-1] A method of making a new electrolysis cell by placing an electrolysis electrode or a layered article from an electrolysis electrode and a new membrane in an existing electrolysis cell, including an anode, a cathode that is opposite the anode, and a membrane that is located between the anode and cathode,

this uses an electrolysis electrode or laminated product in the form of a winding.

[5-2] The method of manufacturing an electrolysis cell according to [5-1], comprising the step (A) of holding the electrolysis electrode or laminated article in a wound state, thereby obtaining a winding.

[5-3] A method for manufacturing an electrolytic cell according to item [5-1] or [5-2], comprising a step (B) of releasing a winding from a coiled state.

[5-4] The method of manufacturing an electrolysis cell according to [5-3], comprising the step (C) of placing an electrolysis electrode or laminated article on the surface of at least one of the anode and the cathode after step (B).

[5-5] A method of renewing an existing electrode using an electrolysis electrode,

wherein an electrolysis electrode is used in the form of a coil.

[5-6] The method for renewing an electrode according to [5-5], comprising the step (A ') of holding the electrolysis electrode in a wound state, thereby obtaining a winding.

[5-7] A method for renewing an electrode according to item [5-5] or [5-6], comprising the step (B ') of releasing the winding from the wound state.

[5-8] The method for renewing an electrode according to item [5-7], comprising the step (C ') of placing the electrode for electrolysis on the surface of the existing electrode after the step (B').

[5-9] A method of obtaining a winding used to renovate an existing electrolyzer, including an anode, a cathode that is opposite the anode, and a membrane that is placed between the anode and cathode, including:

a step of winding the electrolysis electrode or laminated article from the electrolysis electrode and a new membrane, thereby forming a winding.

[0017] As a result of intensive research aimed at achieving the sixth objective, the present inventors found that the above-described problems can be solved by combining an electrolysis electrode with a new membrane at a temperature at which the membrane does not melt, thereby completing the present invention.

Thus, the present invention comprises the following aspects.

[6-1] A method of manufacturing a new electrolyzer by placing a layered product in an existing electrolyzer, including an anode, a cathode that is opposite the anode, and a membrane that is located between the anode and cathode, including:

a step (A) of combining the electrolysis electrode with the new membrane at a temperature at which the membrane does not melt, thereby obtaining a laminated article, and

step (B) replacing the membrane in the existing electrolytic cell with a laminated article after step (A).

[6-2] The method of manufacturing an electrolytic cell according to paragraph [6-1], in which the combination is carried out at normal pressure.

[0018] As a result of intensive research aimed at achieving the seventh objective, the inventors of the present invention found that the above-described problems can be solved by operation on the cell frame, thereby completing the present invention.

Thus, the present invention comprises the following aspects.

[7-1] A method of manufacturing a new electrolyzer by placing a layered article, including an electrode for electrolysis and a new membrane, in an existing electrolyzer, including an anode, a cathode that is opposite the anode, a membrane that is fixed between the anode and cathode, and an electrolyzer frame that supports the anode, cathode and membrane, the method comprising:

step (A) of releasing the membrane secured in the cell frame, and

step (B) replacing the membrane with a laminated article after step (A).

[7-2] The method for manufacturing an electrolytic cell according to [7-1], in which step (A) is performed by extending the anode and cathode in the direction of their placement, respectively.

[7-3] A method for manufacturing an electrolytic cell according to item [7-1] or [7-2], in which the laminated article is fixed in the cell frame by pressing the anode and cathode after step (B).

[7-4] The method of manufacturing an electrolytic cell according to any one of items [7-1] to [7-3], in which the layered article is fixed on the surface of at least one of the anode and the cathode at a temperature at which the layered article does not melt, on stage (B).

[7-5] A method of making a new electrolysis cell by placing an electrode for electrolysis in an existing electrolysis cell, including an anode, a cathode that is opposite the anode, a membrane that is fixed between the anode and cathode, and an electrolyzer frame that supports the anode, cathode and membrane, and method includes:

step (A) of releasing the membrane secured in the cell frame, and

step (B ') placing the electrolysis electrode between the membrane and the anode or cathode after step (A).

Advantageous Effects of the Invention

[0019] (1) According to the electrode for electrolysis according to the present invention, it is possible to facilitate transportation and handling, greatly simplify the work when the operation of a new electrolysis cell is started or a worn-out electrode is renewed, and in addition, the operation can be maintained or improved. parameters of the electrolytic process.

[0020] (2) According to the laminated article according to the present invention, it is possible to improve the working efficiency during the renewal of the electrode in the electrolytic cell, and furthermore also provide excellent electrolysis performance after the renewal.

[0021] (3) According to the layered article according to the present invention, it is possible to improve the working efficiency during the renewal of the electrode in the electrolytic cell, and furthermore, also provide excellent electrolysis performance after the renewal from a position other than the above (2).

[0022] (4) According to the electrolytic cell according to the present invention, the cell exhibits excellent electrolysis performance and can also prevent membrane damage.

[0023] (5) According to the method for manufacturing an electrolytic cell according to the present invention, it is possible to improve the working efficiency during the renewal of the electrode in the cell.

[0024] (6) According to the method for manufacturing an electrolytic cell according to the present invention, it is possible to improve the working efficiency during the renewal of the electrode in the electrolytic cell from a position other than the above-described item (5).

[0025] (7) According to the method for manufacturing an electrolytic cell according to the present invention, it is possible to improve the working efficiency during the renewal of the electrode in the electrolytic cell from a different position than in the above-described items (5) and (6).

Brief Description of Drawings

[0026] [Figure 1] Figure 1 illustrates a schematic sectional view of an electrode for electrolysis according to one embodiment of the present invention.

[Figure 2] Figure 2 illustrates a schematic sectional view showing an ion exchange membrane in one embodiment.

[Figure 3] Figure 3 illustrates a schematic view for explaining the relative opening of the core reinforcing materials constituting the ion exchange membrane.

[Figure 4] Figure 4 illustrates a schematic view for explaining a method of forming vias in an ion exchange membrane.

[Figure 5] Figure 5 illustrates a schematic sectional view of an electrolytic cell.

[Figure 6] Figure 6 is a schematic sectional view showing the state of two electrolytic cells connected in series.

[Figure 7] Figure 7 illustrates a schematic view of an electrolytic cell.

[Figure 8] Figure 8 illustrates a schematic perspective view showing an assembly step of an electrolytic cell.

[Figure 9] Figure 9 illustrates a schematic sectional view of a reverse current absorber included in an electrolytic cell.

[Figure 10] Figure 10 illustrates a schematic view of a method for evaluating a force applied per unit mass · unit area (1) described in Examples.

[Figure 11] Figure 11 illustrates a schematic view of a method for evaluating winding around a 280 mm diameter string (1) described in the Examples.

[Figure 12] Figure 12 illustrates a schematic view of a method for evaluating a winding around a 280 mm diameter string (2) described in the Examples.

[Figure 13] Figure 13 illustrates a schematic view of a method for evaluating winding around a 145 mm diameter string (3) described in the Examples.

[Figure 14] Figure 14 illustrates a schematic view of the elastic deformation test of an electrode described in Examples.

[Figure 15] Figure 15 illustrates a schematic view of a method for evaluating softness after plastic deformation.

[Figure 16] Figure 16 illustrates a schematic view of an electrode manufactured in Comparative Example 13.

[Figure 17] Figure 17 illustrates a schematic view of a structure used to accommodate the electrode manufactured in Comparative Example 13 on a nickel mesh supply conductor.

[Figure 18] Figure 18 illustrates a schematic view of an electrode manufactured in Comparative Example 14.

[Figure 19] Figure 19 illustrates a schematic view of a structure used to accommodate the electrode made in Comparative Example 14 on a nickel mesh supply conductor.

[Figure 20] Figure 20 illustrates a schematic view of an electrode manufactured in Comparative Example 15.

[Figure 21] Figure 21 illustrates a schematic view of a structure used to accommodate an electrode made in Comparative Example 15 on a nickel mesh supply conductor.

[Figure 22] Figure 22 illustrates a schematic sectional view of an electrode for electrolysis in one embodiment of the present invention.

[Figure 23] Figure 23 illustrates a schematic sectional view showing an ion exchange membrane in one embodiment.

[Figure 24] Figure 24 illustrates a schematic view for explaining a relative opening of the core reinforcing materials constituting the ion exchange membrane.

[Figure 25] Figure 25 illustrates a schematic view for explaining a method of forming vias in an ion exchange membrane.

[Figure 26] Figure 26 illustrates a schematic sectional view of an electrolytic cell.

[Figure 27] Figure 27 illustrates a schematic sectional view showing the state of two electrolytic cells connected in series.

[Figure 28] Figure 28 illustrates a schematic view of an electrolytic cell.

[Figure 29] Figure 29 illustrates a schematic perspective view showing an assembly step of an electrolytic cell.

[Figure 30] Figure 30 illustrates a schematic sectional view of a reverse current absorber included in an electrolytic cell.

[Figure 31] Figure 31 illustrates a schematic view of a method for evaluating a force applied per unit mass · unit area (1) described in Examples.

[Figure 32] Figure 32 illustrates a schematic view of a method for evaluating winding around a 280 mm diameter string (1) described in the Examples.

[Figure 33] Figure 33 illustrates a schematic view of a method for evaluating a winding around a 280 mm diameter string (2) described in the Examples.

[Figure 34] Figure 34 illustrates a schematic view of a method for evaluating a winding around a 145 mm diameter string (3) described in the Examples.

[Figure 35] Figure 35 illustrates a schematic view of the elastic deformation test of an electrode described in Examples.

[Figure 36] Figure 36 illustrates a schematic view of a method for evaluating softness after plastic deformation.

[Figure 37] Figure 37 illustrates a schematic view of an electrode manufactured in Example 34.

[Figure 38] Figure 38 illustrates a schematic view of a structure used to accommodate the electrode made in Example 34 on a nickel mesh supply conductor.

[Figure 39] Figure 39 illustrates a schematic view of an electrode manufactured in Example 35.

[Figure 40] Figure 40 illustrates a schematic view of a structure used to accommodate the electrode made in Example 35 on a nickel mesh supply conductor.

[Figure 41] Figure 41 illustrates a schematic view of an electrode manufactured in Example 36.

[Figure 42] Figure 42 illustrates a schematic view of a structure used to accommodate the electrode made in Example 36 on a nickel mesh supply conductor.

[Figure 43] Figure 43 illustrates a schematic sectional view of an electrode for electrolysis in one embodiment of the present invention.

[Figure 44] Figure 44 is a schematic sectional view illustrating an ion exchange membrane in one embodiment.

[Figure 45] Figure 45 illustrates a schematic view for explaining a relative opening of the core reinforcing materials constituting the ion exchange membrane.

[Figure 46] Figure 46 illustrates a schematic view for explaining a method of forming vias in an ion exchange membrane.

[Figure 47] Figure 47A illustrates a schematic sectional view of a laminated article illustrating an aspect in which at least a portion of the electrolysis electrode penetrates and thereby secures the membrane. Fig. 47B is an explanatory view illustrating the step of obtaining the structure of Fig. 47A.

[Figure 48] Figure 48A illustrates a schematic sectional view of a laminated article illustrating an aspect in which at least a portion of an electrolysis electrode is housed within the membrane and thereby secures the membrane. Figure 48B is an explanatory view illustrating the step of obtaining the structure of Figure 48A.

[Figure 49] Figures 49A to 49C illustrate schematic cross-sectional views of a material illustrating an aspect in which a yarn-type fastener is used for anchoring as a fastener for attaching a membrane and an electrolysis electrode.

[Figure 50] Figure 50 illustrates a schematic sectional view of a laminated article illustrating an aspect in which an organic resin is used for anchoring as a fastener for attaching a membrane and an electrolysis electrode.

[Figure 51] Figure 51A illustrates a schematic cross-sectional view of a laminated article illustrating an aspect in which at least a portion of the fastener grips the membrane and the electrolysis electrode from the outside, holding them together. Figure 51B illustrates a schematic sectional view of a laminated article illustrating an aspect in which at least a portion of the fastener secures the membrane and the electrolysis electrode with magnetic force.

[Figure 52] Figure 52 illustrates a schematic sectional view of an electrolytic cell.

[Figure 53] Figure 53 is a schematic sectional view showing the state of two electrolytic cells connected in series.

[Figure 54] Figure 54 illustrates a schematic view of an electrolytic cell.

[Figure 55] Figure 55 is a schematic perspective view showing a step of assembling an electrolytic cell.

[Figure 56] Figure 56 illustrates a schematic sectional view of a reverse current absorber that may be included in an electrolytic cell.

[Figure 57] Figure 57 illustrates an explanatory view showing the laminated article in Example 1.

[Figure 58] Figure 58 illustrates an explanatory view showing the laminated article in Example 2.

[Figure 59] Figure 59 illustrates an explanatory view showing the laminated article in Example 3.

[Figure 60] Figure 60 illustrates an explanatory view showing the laminated article in Example 4.

[Figure 61] Figure 61 illustrates an explanatory view showing the laminated article in Example 5.

[Figure 62] Figure 62 illustrates an explanatory view showing the laminated article in Example 6.

[Figure 63] Figure 63 illustrates a schematic sectional view of an electrolytic cell.

[Figure 64] Figure 64A illustrates a schematic sectional view showing the state of two electrolytic cells connected in series in a conventional electrolytic cell. Fig. 64B is a schematic cross-sectional view showing the state of two electrolytic cells connected in series in the electrolytic cell of the present embodiment.

[Figure 65] Figure 65 illustrates a schematic view of an electrolytic cell.

[Figure 66] Figure 66 is a schematic perspective view showing a step of assembling an electrolytic cell.

[Figure 67] Figure 67 illustrates a schematic sectional view of a reverse current absorber that may be included in an electrolytic cell.

[Figure 68] Figure 68 illustrates a schematic sectional view of an electrode for electrolysis in one embodiment of the present invention.

[Figure 69] Figure 69 is a schematic sectional view illustrating an ion exchange membrane in one embodiment.

[Figure 70] Figure 70 illustrates a schematic view for explaining the opening ratio of the core reinforcing materials constituting the ion exchange membrane.

[Figure 71] Figure 71 illustrates a schematic view for explaining a method of forming vias in an ion exchange membrane.

[Figure 72] Figure 72 illustrates an explanatory view for explaining the mutual relative position of the laminate and the seals.

[Figure 73] Figure 73 illustrates an explanatory view for explaining the mutual relative position of the laminate and the seals.

[Figure 74] Figure 74A illustrates a schematic sectional view of a laminated article illustrating an aspect in which at least a portion of the electrolysis electrode penetrates and thereby secures the membrane. Figure 74B is an explanatory view illustrating a step for obtaining the structure of Figure 12A.

[Figure 75] Figure 75A illustrates a schematic sectional view of a laminated article illustrating an aspect in which at least a portion of an electrolysis electrode is housed within the membrane and thereby secured it. Figure 13B is an explanatory view illustrating the step of obtaining the structure of Figure 75A.

[Figure 76] Figures 76A-C illustrate schematic cross-sectional views of a laminated article illustrating an aspect in which a yarn-type fastener is used for fastening as a fastener for fastening the membrane and electrolysis electrode.

[Figure 77] Figure 77 illustrates a schematic sectional view of a laminated article illustrating an aspect in which an organic resin is used for anchoring as a fastener for attaching a membrane and an electrolysis electrode.

[Figure 78] Figure 78A illustrates a schematic sectional view of a laminated article illustrating an aspect in which at least a portion of the fastener grips the membrane and the electrolysis electrode from the outside to secure them. Figure 78B illustrates a schematic sectional view of a laminated article illustrating an aspect in which at least a portion of the fastener secures the membrane and the electrolysis electrode with magnetic force.

[Figure 79] Figure 79 illustrates a schematic view of a method for evaluating a force applied per unit mass · unit area (1) described in Examples.

[Figure 80] Figure 80 illustrates a schematic view of a method for evaluating winding around a 280 mm diameter string (1) described in the Examples.

[Figure 81] Figure 81 illustrates a schematic view of a method for evaluating a winding around a 280 mm diameter string (2) described in the Examples.

[Figure 82] Figure 82 illustrates a schematic view of a method for evaluating winding around a 145 mm diameter string (3) described in the Examples.

[Figure 83] Figure 83 illustrates a schematic view of evaluating the flexibility of an electrode described in Examples.

[Figure 84] Figure 84 illustrates a schematic view of evaluating softness after plastic deformation.

[Figure 85] Figure 85 illustrates a schematic view of an electrode manufactured in Example 35.

[Figure 86] Figure 86 illustrates a schematic view of a structure used to accommodate the electrode made in Example 35 on a nickel mesh supply conductor.

[Figure 87] Figure 87 illustrates a schematic view of an electrode manufactured in Example 36.

[Figure 88] Figure 88 illustrates a schematic view of a structure used to accommodate the electrode made in Example 36 on a nickel mesh supply conductor.

[Figure 89] Figure 89 illustrates a schematic view of an electrode manufactured in Example 37.

[Figure 90] Figure 90 illustrates a schematic view of a structure used to accommodate the electrode made in Example 37 on a nickel mesh supply conductor.

[Figure 91] Figure 91 illustrates a schematic sectional view of an electrolytic cell.

[Figure 92] Figure 92 illustrates a schematic sectional view showing the state of two electrolytic cells connected in series.

[Figure 93] Figure 93 illustrates a schematic view of an electrolytic cell.

[Figure 94] Figure 94 is a schematic perspective view showing a step of assembling an electrolytic cell.

[Figure 95] Figure 95 illustrates a schematic sectional view of a reverse current absorber that may be included in an electrolytic cell.

[Figure 96] Figure 96 illustrates a schematic sectional view of an electrode for electrolysis in one embodiment of the present invention.

[Figure 97] Figure 97 illustrates a schematic sectional view of an ion exchange membrane in one embodiment.

[Figure 98] Figure 98 illustrates a schematic view for explaining a relative opening of the core reinforcing materials constituting the ion exchange membrane.

[Figure 99] Figure 99 illustrates a schematic view for explaining a method of forming vias in an ion exchange membrane.

[Figure 100] Figure 100 illustrates a schematic view of a laminated article obtained in Example 1.

[Figure 101] Figure 101 illustrates a schematic view of a situation where the laminated article obtained in Example 1 is wound to form a winding.

[Figure 102] Figure 102 illustrates a schematic view of a laminated article obtained in Example 4.

[Figure 103] Figure 103 illustrates a schematic sectional view of an electrolytic cell.

[Figure 104] Figure 104 illustrates a schematic cross-sectional view showing the state of two electrolytic cells connected in series.

[Figure 105] Figure 105 illustrates a schematic view of an electrolytic cell.

[Figure 106] Figure 106 illustrates a schematic perspective view showing a step in assembling an electrolytic cell.

[Figure 107] Figure 107 illustrates a schematic sectional view of a reverse current absorber that may be included in an electrolytic cell.

[Figure 108] Figure 108 illustrates a schematic sectional view of an electrode for electrolysis in one embodiment of the present invention.

[Figure 109] Figure 109 illustrates a schematic sectional view of an ion exchange membrane in one embodiment.

[Figure 110] Figure 110 illustrates a schematic view for explaining a relative opening of the core reinforcing materials constituting the ion exchange membrane.

[Figure 111] Figure 111 illustrates a schematic view for explaining a method of forming vias in an ion exchange membrane.

[Figure 112] Figure 112 illustrates a schematic sectional view of an electrolytic cell.

[Figure 113] Figure 113 is a schematic cross-sectional view showing the state of two electrolytic cells connected in series.

[Figure 114] Figure 114 illustrates a schematic view of an electrolytic cell.

[Figure 115] Figure 115 illustrates a schematic perspective view showing a step of assembling an electrolytic cell.

[Figure 116] Figure 116 illustrates a schematic sectional view of a reverse current absorber that may be included in an electrolytic cell.

[Figure 117] Figure 117 (A) illustrates a schematic view of an electrolytic cell for explaining one example of each step according to the first aspect of the present embodiment. Figure 117 (B) illustrates a schematic perspective view corresponding to Figure 117 (A).

[Figure 118] Figure 118 (A) illustrates a schematic view of an electrolytic cell for explaining one example of each step according to a second aspect of the present embodiment. Figure 118 (B) illustrates a schematic perspective view corresponding to Figure 118 (A).

[Figure 119] Figure 119 illustrates a schematic sectional view of an electrode for electrolysis in one embodiment of the present invention.

[Figure 120] Figure 120 illustrates a schematic sectional view of an ion exchange membrane in one embodiment.

[Figure 121] Figure 121 illustrates a schematic view for explaining the opening ratio of the core reinforcing materials constituting the ion exchange membrane.

[Figure 122] Figure 122 illustrates a schematic view for explaining a method of forming vias in an ion exchange membrane.

Description of embodiments of the invention

[0027] Hereinafter, as embodiments of the present invention (hereinafter may be referred to as the present embodiments), detailed descriptions of each <First Embodiment> to <Seventh Embodiment> will be made with reference to the drawings as necessary. The following embodiments are illustrations for explaining the present invention, and the present invention is not limited to the content set forth below. The accompanying drawings illustrate one example of embodiments, and the embodiments are not to be construed as limited thereto. The present invention can be appropriately modified and practiced within its spirit. In the drawings, positional relationships such as top, bottom, left, and right are based on the mutual relative orientations shown in the drawings, unless otherwise indicated. The dimensions and relationships in the drawings are not limited to those shown.

<First embodiment>

[0028] Here, a first embodiment of the present invention will be described in detail with reference to Figures 1-21.

[0029] [Electrolysis Electrode]

The electrolysis electrode in the first embodiment (hereinafter in the <First Embodiment>, referred to simply as "the present embodiment") can provide good processing performance, has good adhesion to a membrane such as an ion exchange membrane and a microporous membrane, with a worn electrode , a feed conductor not having a catalytic coating, and the like, and further has a mass per unit area of 48 mg / cm ² or less in terms of economy. The mass per unit area is preferably 30 mg / cm ² or less, more preferably 20 mg / cm ² or less in view of the above, and furthermore is preferably 15 mg / cm ² or less for general reasons including manufacturability (carrying out loading and unloading operations), adhesion strength and efficiency. The lower limit is not particularly limited, but is, for example, on the order of 1 mg / cm ² .

The above-described mass per unit area may be within the above-described range, for example, by appropriately adjusting, for example, the open porosity ratio, electrode thickness, and the like described below. More specifically, for example, when the thickness is constant, a higher open porosity ratio results in a decrease in mass per unit area, and a lower open porosity ratio results in a higher mass per unit area.

The electrode for electrolysis of the present embodiment should provide a force per unit mass · unit area of 0.08 N / (mg · cm ² ) or more from the viewpoint of good workability, and have good adhesion to a membrane such as an ion exchange membrane. or a microporous membrane with a worn electrode, a supply conductor not having a catalytic coating, and the like. The force applied per unit mass unit area is preferably 0.1 N / (mg cm ² ) or more, more preferably 0.14 N / (mg cm ² ) or more with respect to the above, and more preferably 0, 2 N / (mg · cm ² ) or more from the point of view of additional facilitation of loading and unloading at a large size (for example, size 1.5 m × 2.5 m). The upper limit is not particularly limited, but is preferably 1.6 N / (mg cm ² ) or less, more preferably less than 1.6 N / (mg cm ² ), further preferably 1.5 N / (mg cm 2) ² ), even more preferably 1.2 N / (mg · cm ² ) or less, even more preferably 1.20 N / (mg · cm ² ) or less. The upper limit value is even more preferably 1.1 N / (mg cm ² ) or less, further even more preferably 1.10 N / (mg cm ² ) or less, particularly preferably 1.0 N / (mg · Cm ² ) or less, particularly preferably 1.00 N / (mg · cm ² ) or less.

[0030] Considering that the electrode for electrolysis of the present embodiment, if it is an electrode having a wide elastic deformation range, can provide better workability and has better adhesion to a membrane such as an ion exchange membrane or a microporous membrane with a worn electrode , a feed conductor not having a catalytic coating, and the like, the thickness of the electrode for electrolysis is preferably 315 μm or less, more preferably 220 μm or less, even more preferably 170 μm or less, even more preferably 150 μm or less, especially preferably 145 µm or less, even more preferably 140 µm or less, further even more preferably 138 µm or less, even more preferably 135 µm or less. A thickness of 135 µm or less can provide good workability. In addition, for reasons similar to the above, the thickness is preferably 130 µm or less, more preferably less than 130 µm, further preferably 115 µm or less, even more preferably 65 µm or less. The lower limit is not particularly limited, but is preferably 1 µm or more, more preferably 5 µm or more for practical reasons, more preferably 20 µm or more. In the present embodiment, “having a wide elastic range” means that when the electrolysis electrode is wound to form a winding, it is unlikely that winding-induced warping will occur after being released from the wound state. The thickness of the electrolysis electrode when the below-mentioned catalyst layer is provided refers to the total thickness of both the electrolysis electrode support and the catalyst layer.

[0031] The electrolysis electrode of the present embodiment, which has good adhesion to a membrane such as an ion exchange membrane or a microporous membrane, with a worn electrode, an uncatalyzed supply conductor, and the like, as described above, can be combined with a membrane such as an ion exchange membrane or a microporous membrane, and is used. On this basis, when the electrode is renewed, the electrode can be renewed under the conditions of such a simple operation as membrane renewal, without complex replacement work such as pulling out the electrode attached to the electrolytic cell, and thereby noticeably improve the working efficiency. Even in the case where only the supply conductor is placed in the new electrolytic cell (i.e., an electrode having no catalyst layer is placed), the operation of the electrode only ensures that the electrolysis electrode of the present embodiment is connected to the supply conductor. Thus, appreciable reduction or elimination of the catalytic coating can also be possible.

[0032] In addition, according to the electrode for electrolysis of the present embodiment, it is possible to make the electrolysis performance (electrolytic process) comparable to or better than that of the new electrode.

The electrolysis electrode of the present embodiment can be stored or transported to consumers in a state where the electrode is wound around a vinyl chloride pipe or the like (in a wound state or the like), greatly facilitating handling.

The applied force can be measured by methods (i) or (ii) described below, which are as detailed in the Examples. With regard to the applied force, the value obtained by measuring by method (i) (also called "applied force (1)") and the value obtained by measuring by method (ii) (also called "applied force (2)") may be the same or different, and each value is 0.08 N / (mg · cm ² ) or more.

The above-described applied force may be within the above-described range by appropriately adjusting, for example, the below-described open porosity ratio, electrode thickness, arithmetic mean of surface roughness, and the like. For example, more specifically, a higher open porosity ratio results in less applied force, and a lower open porosity ratio results in more applied force.

[0033] [Method (i)]

Nickel plate, obtained by blasting with alumina with a grain number (grain size) of 320 (thickness 1.2 mm, square with a side of 200 mm), ion exchange membrane, which is obtained by applying particles of inorganic material and a binder to both surfaces of a perfluorocarbon polymer into which an ion exchange group (170 mm square, details of the ion exchange membrane disclosed herein are described in the Examples), and an electrolysis electrode sample (130 mm square) are layered in that order. Thereafter, the laminated product is sufficiently immersed in clean water, and excess water deposited on the surface of the laminated product is removed to obtain a sample for measurement. The arithmetic mean (Ra) of the surface roughness of the nickel plate after blasting was 0.7 μm. A specific method for calculating the arithmetic mean (Ra) of the surface roughness is described in the Examples.

Under the condition of temperature 23 ± 2 ° C and relative humidity 30 ± 5%, only the electrolysis electrode sample in this measurement sample is lifted in the vertical direction at a speed of 10 mm / minute using a tensile compression machine and the load is measured when the sample the electrolysis electrode rises 10 mm in the vertical direction. This measurement is repeated three times and the average is calculated.

This average value is divided by the area of the overlapping area of the electrolysis electrode sample and the ion exchange membrane and by the mass of the ion exchange membrane in the area of overlapping with the electrolysis electrode sample to calculate the applied force per unit mass unit area (1) (N / (mg cm ² ) ).

[0034] The applied force per unit mass · unit area (1) obtained by method (i) is 0.08 N / (mg · cm ² ) or more, preferably 0.1 N / (mg · cm ² ) or more from the point of view of providing good processability and good adhesion to a membrane such as an ion exchange membrane or a microporous membrane, a worn electrode and an uncatalyzed supply conductor, and more preferably 0.2 N / (mg cm ² ) or more with positions for additional facilitation of loading and unloading with a large size (for example, size 1.5 m × 2.5 m). The upper limit is not particularly limited, but is preferably 1.6 N / (mg cm ² ) or less, more preferably less than 1.6 N / (mg cm ² ), further preferably 1.5 N / (mg cm 2) ² ), even more preferably 1.2 N / (mg · cm ² ) or less, even more preferably 1.20 N / (mg · cm ² ) or less. The upper limit value is even more preferably 1.1 N / (mg cm ² ) or less, further even more preferably 1.10 N / (mg cm ² ) or less, particularly preferably 1.0 N / (mg · Cm ² ) or less, particularly preferably 1.00 N / (mg · cm ² ) or less.

[0035] When the electrode for electrolysis of the present embodiment satisfies the applied force (1), the electrode may be combined with a membrane such as an ion exchange membrane or a microporous membrane, for example, and used. Thus, when the electrode is renewed, the operation of replacing the cathode and anode fixed to the electrolytic cell in a manner such as welding is eliminated, and the work efficiency is noticeably improved. In addition, by using the electrolysis electrode of the present embodiment as the electrode combined with the ion exchange membrane, the electrolysis performance can be made comparable to or better than that of the new electrode.

When a new electrolytic cell is shipped, the electrode attached to the electrolytic cell has traditionally been catalytically coated. Since only the combination of the uncatalyzed electrode with the electrolysis electrode of the present embodiment can function the electrode as an electrode, the production step and the volume of the catalyst for the catalytic coating can be significantly reduced or eliminated. A conventional electrode whose catalytic coating has been markedly reduced or removed may be electrically connected to the electrolysis electrode of the present embodiment and left serving as a supply conductor for passing electric current.

[0036] [Method (ii)]

A nickel plate blasted with alumina 320 grit (thickness 1.2 mm, square with a side of 200 mm, a nickel plate similar to the plate in the above method (i)) and an electrolysis electrode sample (square with a side of 130 mm) are layered in that order. Thereafter, the laminated product is sufficiently immersed in clean water, and excess water deposited on the surface of the laminated product is removed to obtain a sample for measurement. Under the condition of temperature 23 ± 2 ° C and relative humidity 30 ± 5%, only the electrolysis electrode sample in this measurement sample is lifted in the vertical direction at a speed of 10 mm / minute using a tensile compression machine and the load is measured when the sample the electrolysis electrode rises 10 mm in the vertical direction. This measurement is repeated three times and the average is calculated.

This average value is divided by the area of the overlapping area of the electrolysis electrode sample and the nickel plate, and by the mass of the electrolysis electrode sample in the overlapping area with the nickel plate to calculate the applied force per unit mass unit area (2) (N / (mg cm ² )).

[0037] The applied force per unit mass · unit area (2) obtained by method (ii) is 0.08 N / (mg · cm ² ) or more, preferably 0.1 N / (mg · cm ² ) or more from the point of view of ensuring good processability and good adhesion to a membrane such as an ion exchange membrane or a microporous membrane, a worn electrode, and an uncatalyzed supply conductor, and more preferably 0.14 N / (mg cm ² ) or more from the position of additional facilitation of loading and unloading with a large size (for example, size 1.5 mx 2.5 m). The upper limit is not particularly limited, but is preferably 1.6 N / (mg cm ² ) or less, more preferably less than 1.6 N / (mg cm ² ), further preferably 1.5 N / (mg cm 2) ² ), even more preferably 1.2 N / (mg · cm ² ) or less, even more preferably 1.20 N / (mg · cm ² ) or less. The upper limit value is even more preferably 1.1 N / (mg cm ² ) or less, further even more preferably 1.10 N / (mg cm ² ) or less, particularly preferably 1.0 N / (mg · Cm ² ) or less, particularly preferably 1.00 N / (mg · cm ² ) or less.

The electrolysis electrode of the present embodiment, if satisfies the applied force (2), can be stored or transported to consumers in a state where the electrode is wound around a vinyl chloride pipe or the like (in a wound state or the like), greatly facilitating handling. By connecting the electrolysis electrode of the present embodiment to a worn electrode, electrolysis performance can be made comparable to or better than that of a new electrode.

[0038] In the present embodiment, as a liquid enclosed between a membrane such as an ion exchange membrane or a microporous membrane, an electrolysis electrode or a supply conductor (a worn electrode or an electrode not having a catalytic coating), and an electrolysis electrode, any liquid such as water or organic solvents, provided that the liquid creates surface tension. The higher the surface tension of the liquid, the greater the force applied between the membrane and the electrolysis electrode or between the metal plate and the electrolysis electrode. Thus, a liquid having a higher surface tension is preferred. Examples of a liquid include the following (the numerical value in parentheses represents the surface tension of the liquid).

[0039] Hexane (20.44 mN / m), acetone (23.30 mN / m), methanol (24.00 mN / m), ethanol (24.05 mN / m), ethylene glycol (50.21 mN / m) and water (72.76 mN / m).

[0040] The liquid having a high surface tension allows the membrane and the electrolysis electrode, or the porous metal plate or metal plate (supply conductor) and the electrolysis electrode (to form a laminated article) to be combined, thereby facilitating the renewal of the electrode. The liquid between the membrane and the electrolysis electrode, or between the porous metal plate or the metal plate (supply conductor) and the electrolysis electrode, may be present in such an amount that both of them adhere to each other (adhere to each other) under the action of surface tension. As a result, after placing the layered article in the electrolytic cell, the liquid, if mixed with the electrolyte solution, does not affect the electrolysis itself due to the small amount of liquid.

From a practical point of view, as the liquid, a liquid having a surface tension of 20 mN / m to 80 mN / m such as ethanol, ethylene glycol and water is preferably used. Particularly preferred is water or an aqueous alkali solution obtained by dissolving caustic soda, potassium hydroxide, lithium hydroxide, sodium hydrogencarbonate, potassium hydrogencarbonate, sodium carbonate, potassium carbonate or the like in water. Alternatively, the surface tension can be adjusted by bringing these fluids into contact with a surfactant. When a surfactant is contained, the adhesion (bond strength) between the membrane and the electrolysis electrode, or between the metal plate and the electrolysis electrode, is changed, allowing processability to be adjusted. The surfactant is not particularly limited, and both ionic surfactants and nonionic surfactants can be used.

[0041] The electrolysis electrode of the present embodiment preferably comprises an electrolysis electrode support and a catalyst layer. The thickness of the electrode substrate for electrolysis (measured thickness) is not particularly limited, but is preferably 300 μm or less, more preferably 205 μm or less, even more preferably 155 μm or less, further preferably 135 μm or less, even more preferably 125 μm or less , even more preferably 120 µm or less, even more preferably 100 µm or less from the point of view of ensuring good processability, achieving good adhesion to a membrane such as an ion exchange membrane or a microporous membrane, with a worn electrode and a supply conductor not having a catalytic coating being capable of being rolled and satisfactorily foldable and facilitating handling at a large size (e.g., 1.5 m × 2.5 m), and in addition, even more preferably 50 μm or less, with the point of view of manufacturability and efficiency. The lower limit is not particularly limited, but is, for example, 1 µm, preferably 5 µm, more preferably 15 µm.

[0042] The proportion measured by method (2) on the electrode for electrolysis of the present embodiment is not particularly limited, but is preferably 90% or more, more preferably 92% or more from the viewpoint of good workability and good membrane adhesion. , such as an ion exchange membrane or a microporous membrane, with a worn electrode, a feed conductor not having a catalytic coating, and additionally preferably 95% or more in terms of further facilitating loading and unloading at a large size (for example, size 1.5 m × 2 , 5 m). The upper limit value is 100%.

[Method (2)]

An ion exchange membrane (170 mm square) and a sample electrolysis electrode (130 mm square) are layered in this order. The laminated article is placed on the curved surface of a polyethylene pipe (outer diameter: 280 mm) so that the electrode sample for electrolysis in this laminated article is positioned outside at a temperature of 23 ± 2 ° C and a relative humidity of 30 ± 5%, the laminated article and pipe are sufficient immersed in clean water, remove the excess water deposited on the surface of the laminated product and the pipe, and then, one minute after this removal, measure the fraction (%) of the area of the area in which the ion-exchange membrane (square with a side of 170 mm) is in a dense contact with the electrolysis electrode.

[0043] The proportion measured by the following method (3) on the electrolysis electrode of the present embodiment is not particularly limited, but is preferably 75% or more, more preferably 80% or more from the viewpoint of providing good workability, achieving good adhesion strength with membrane, such as an ion exchange membrane or microporous membrane, with a worn electrode, an uncatalytically coated supply conductor and for proper roll-winding and satisfactory creasing, and additionally preferably 90% or more in terms of further facilitating conduction loading and unloading at a large size (for example, size 1.5 mx 2.5 m). The upper limit value is 100%.

[Method (3)]

An ion exchange membrane (170 mm square) and a sample electrolysis electrode (130 mm square) are layered in this order. The laminated product is placed on the curved surface of a polyethylene pipe (outer diameter: 145 mm) so that the sample electrode for electrolysis in this laminated product is positioned outside at a temperature of 23 ± 2 ° C and a relative humidity of 30 ± 5%, the laminated product and the pipe are sufficient immersed in clean water, remove the excess water deposited on the surface of the laminated product and the pipe, and then, one minute after this removal, measure the fraction (%) of the area of the area in which the ion-exchange membrane (square with a side of 170 mm) is in a dense contact with the electrolysis electrode.

The electrode for electrolysis of the present embodiment has, but is not specifically limited to, a porous structure and an open porosity ratio or void ratio of 5 to 90% or less in terms of ensuring good processability, achieving good adhesion to a membrane such as an ion exchange membrane, or microporous membrane, with a worn electrode, and with a supply conductor not having a catalytic coating, and preventing the accumulation of gas evolved during electrolysis. The open porosity ratio is more preferably 10 to 80% or less, more preferably 20 to 75%.

The open porosity ratio is the fraction of the lumen areas per unit volume. The calculation method may differ depending on whether sub-micron-sized lumen regions are considered or only visible lumens (holes) are considered. In the present embodiment, the volume V was calculated from the values of the measured thickness, the width and the length of the electrode, and in addition, the weight W was measured to thereby calculate the open porosity coefficient A by the following formula:

A = (1– (W / (V × ρ)) × 100

[0044] ρ is the density of the electrode material (g / cm ³ ). For example, the ρ of nickel is 8.908 g / cm ³ and the ρ of titanium is 4.506 g / cm ³ . The open porosity ratio is appropriately controlled by changing the area of perforated metal per unit area in the case of a perforated metal sheet, changing the values of SW (short diameter), LW (long diameter), and feed in the case of expanded metal sheet, changing the linear dimensions of the diameter of the metal fiber, and sieve numbers in the case of a mesh, a change in the photoresist pattern used in the case of electrospinning, a change in the diameter of the metal fiber and the density of the fiber in the case of a nonwoven fabric, a change in the mold for forming cavities in the case of a porous metal, or the like.

[0045] The value obtained by measuring by the following method (A) of the electrode for electrolysis of the present embodiment is preferably 40 mm or less, more preferably 29 mm or less, further preferably 10 mm or less, even more preferably 6.5 mm or less from the standpoint of manufacturability. The specific measurement method is as described in the Examples.

[Method (A)]

At a temperature of 23 ± 2 ° C and a relative humidity of 30 ± 5%, a sample obtained by layering an ion exchange membrane and an electrolysis electrode is wound around and fixed on the curved surface of a sleeve (core) made of polyvinyl chloride and having an outer diameter of ∅ 32 mm, and leave standing for 6 hours; thereafter, when the electrolysis electrode is separated from the sample and placed on the flat plate, the heights L ₁ and L ₂ in the vertical direction at both edges of the electrolysis electrode are measured, and their average value is used as the measurement value.

[0046] In the electrolysis electrode in the present embodiment, the ventilation resistance measured under conditions of a temperature of 24 ° C, a relative humidity of 32%, a piston speed of 0.2 cm / s and a ventilation volume of 0.4 cm ³ / cm ² / s (here hereinafter also referred to as “measurement condition 1”) is preferably 24 kPa · s / m or less when the electrolysis electrode has a size of 50 mm × 50 mm (hereinafter also referred to as “ventilation resistance 1”). A high ventilation resistance means that the air flows with more difficulty and belongs to a high density state. In this state, the electrolysis product remains in the electrode, and the reagents are more difficult to diffuse into the inside of the electrode, and thus the electrolysis operating parameters (such as voltage) tend to deteriorate. The concentration on the membrane surface tends to increase. More specifically, the concentration of caustic soda increases at the surface of the cathode, and the supply of brine to the surface of the anode tends to decrease. As a result, the product accumulates to a high concentration at the interface where the membrane contacts the electrode. This build-up leads to damage to the membrane at the cathode surface and damage to the membrane at the anode surface. In the present embodiment, in order to prevent these defects, the ventilation resistance is preferably controlled to 24 kPa · s / m or less. For similar reasons, as above, the ventilation resistance is more preferably less than 0.19 kPa · s / m, further preferably 0.15 kPa · s / m or less, even more preferably 0.07 kPa · s / m or less.

In the present embodiment, when the ventilation resistance is higher than a certain value, NaOH evolved at the electrode tends to accumulate at the interface between the electrode and the membrane, resulting in a high concentration in the case of the cathode, and the brine supply tends to be reduced, causing the brine concentration to decrease. case of the anode. To prevent damage to the membrane that can be caused by such accumulation, the ventilation resistance is preferably less than 0.19 kPa s / m, more preferably 0.15 kPa s / m or less, even more preferably 0.07 kPa s / m or less.

In contrast, when the ventilation resistance is low, the area of the electrode is reduced and the area over which electrolysis occurs is reduced. Thus, electrolysis operating parameters (such as voltage) may deteriorate. When the ventilation resistance becomes zero, the supply conductor acts as an electrode since no electrode for electrolysis is provided, and the electrolysis operating parameters (such as voltage) tend to deteriorate markedly. From this point of view, the preferable lower limit value identified as ventilation resistance 1 is not particularly limited, but is preferably more than 0 kPa s / m, more preferably 0.0001 kPa s / m or more, even more preferably 0.001 kPa s / m or more.

When the ventilation resistance 1 is 0.07 kPa · s / m or less, sufficient measurement accuracy may not be achieved by the measurement method used. From this point of view, it is also possible to evaluate an electrolysis electrode having a ventilation resistance 1 of 0.07 kPa · s / m or less using a ventilation resistance (hereinafter also referred to as "ventilation resistance 2") obtained by the following measurement method ( hereinafter also referred to as "measurement condition 2"). That is, the ventilation resistance 2 is the ventilation resistance measured when the electrolysis electrode has a size of 50 mm × 50 mm, under conditions of a temperature of 24 ° C, a relative humidity of 32%, a piston speed of 0.2 cm / s and a ventilation volume of 0.4. cm ³ / cm ² / s.

Specific methods for measuring ventilation resistances 1 and 2 are described in Examples.

Ventilation resistances 1 and 2 can be within the above-described range by appropriately adjusting, for example, open porosity ratio, electrode thickness, and the like. More specifically, for example, when the thickness is constant, a higher open porosity ratio tends to lead to lower ventilation resistance values 1 and 2, and a lower open porosity ratio leads to higher ventilation resistance values 1 and 2.

[0047] Hereinafter, one aspect of the electrolysis electrode of the present embodiment will be described.

The electrolysis electrode of the present embodiment preferably comprises an electrolysis electrode support and a catalyst layer. The catalyst bed can be composed of multiple layers, as shown below, or can have a single layer configuration.

As shown in FIG. 1, the electrolysis electrode 100 of the present embodiment includes an electrolysis electrode substrate 10 and a pair of first layers 20 that cover both surfaces of the electrolysis electrode substrate 10. The first layers 20 preferably cover the entire electrode substrate 10 for electrolysis. Apparently, this coating increases the catalytic activity and durability of the electrode. One first layer 20 can only be laminated to one surface of the electrolysis electrode substrate 10.

Figure 1 also shows that the surfaces of the first layers 20 can be covered with the second layers 30. The first layers 20 are preferably covered with the second layers 30 in their entirety. Alternatively, one second layer 30 may be laminated to only one surface of the first layer 20.

[0048] (Electrode support for electrolysis)

As the electrode substrate 10 for electrolysis, for example, nickel, nickel alloys, stainless steel, and, in addition, valve metals, including titanium, can be used, although not limited thereto. Preferably, at least one element selected from nickel (Ni) and titanium (Ti) is used. That is, the electrode substrate for electrolysis preferably contains at least one member selected from nickel (Ni) and titanium (Ti).

When stainless steel is used in an aqueous alkali solution of high concentration, iron and chromium are washed out and the electrical conductivity is in the order of one tenth that of nickel. In view of the above, as the electrode substrate for electrolysis, a substrate containing nickel (Ni) is preferable.

Alternatively, when the electrode substrate 10 for electrolysis is used in a brine with a high concentration close to saturation, in an atmosphere in which chlorine gas is generated, the material of the electrode substrate 10 is also preferably titanium having high corrosion resistance.

[0049] The shape of the electrode substrate 10 for electrolysis is not particularly limited, and a shape suitable for this purpose can be selected. As the mold, any of a perforated metal sheet, a nonwoven fabric, a porous metal, an expanded metal sheet, an electrospinning metal porous foil, a so-called woven metal mesh formed by an interlacing of metal filaments, and the like can be used. Of these, perforated metal sheet or expanded metal sheet is preferable. Electrospinning is a method of producing a thin metal foil having a precisely shaped pattern using photolithography and electrodeposition in combination. It is a method including patterning a substrate with a photoresist and electrodeposition of a portion not protected by the resist to form a metal thin film.

With regard to the shape of the electrode support for electrolysis, a suitable specification depends on the distance between the anode and the cathode in the electrolysis cell. In the case where the distance between the anode and the cathode is finite, the shape of an expanded metal sheet or a perforated metal sheet can be used, and in the case of a so-called zero-gap electrolyzer in which the ion exchange membrane is in contact with the electrode, a formed interlacing of fine metal filaments, woven metal mesh, porous metal, metal nonwoven fabric, expanded metal sheet, perforated metal sheet, metal porous foil, and the like, although not limited thereto.

[0050] Examples of the electrode substrate 10 for electrolysis include metal foil, wire mesh, metal nonwoven fabric, perforated metal sheet, expanded metal sheet, or porous metal.

As the plate material before being processed to form a perforated metal sheet or expanded metal sheet, rolled plate materials and electrolytic foils are preferred. The electrolytic foil is preferably subjected to a further electrodeposition treatment using the same element as its base material as a further treatment to thereby form roughness on its surface.

The thickness of the electrolysis electrode substrate 10 as mentioned above is preferably 300 µm or less, more preferably 205 µm or less, further preferably 155 µm or less, even more preferably 135 µm or less, even more preferably 125 µm or less, even more preferably 120 µm or less, even more preferably 100 µm or less, and further even more preferably 50 µm or less in terms of processability and economy. The lower limit is not particularly limited, but is, for example, 1 µm, preferably 5 µm, more preferably 15 µm.

In the electrolysis electrode substrate, residual stress during processing is preferably relieved by annealing the electrolysis electrode substrate in an oxidizing atmosphere. It is preferable to form roughness (protrusions) using a steel grid, an alumina grid or the like on the surface of the electrode substrate for electrolysis, followed by acid treatment to increase its surface area in order to improve adhesion to the catalyst layer that is coated on the surface. It is preferable to carry out the electrodeposition treatment using the same element as the substrate in order to increase the surface area.

To bring the first layer 20 into intimate contact with the surface of the electrolysis electrode substrate 10, the electrolysis electrode substrate 10 is preferably subjected to a surface area increasing treatment. Examples of surface area enhancing treatments include chopped wire blasting, steel grating, alumina grating or the like, acidizing using sulfuric acid or hydrochloric acid, and electrodeposition using the same element as in the substrate. The arithmetic mean (Ra) of the surface roughness on the surface of the substrate is not particularly limited, but is preferably 0.05 µm to 50 µm, more preferably 0.1 to 10 µm, even more preferably 0.1 to 5 µm.

[0051] Next, a case will be described where the electrolysis electrode of the present embodiment is used as an anode for conventional salt electrolysis.

(First layer)

In Figure 1, the first layer 20 contains at least one of ruthenium oxides, iridium oxides and titanium oxides as a catalyst layer. Examples of ruthenium oxide include RuO ₂ . Examples of iridium oxide include IrO ₂ . Examples of titanium oxide include TiO ₂ . The first layer 20 preferably contains two oxides: ruthenium oxide and titanium oxide, or three oxides: ruthenium oxide, iridium oxide and titanium oxide. This makes the first layer 20 more stable and further improves adhesion (adhesive strength) to the second layer 30.

When the first layer 20 contains two oxides: ruthenium oxide and titanium oxide, the first layer 20 preferably contains from 1 to 9 moles, more preferably from 1 to 4 moles of titanium oxide, based on 1 mole of ruthenium oxide contained in the first layer 20. In a composite the ratio of two oxides in this range, the electrolysis electrode 100 exhibits excellent resistance.

When the first layer 20 contains three oxides: ruthenium oxide, iridium oxide and titanium oxide, the first layer 20 preferably contains 0.2 to 3 moles, more preferably 0.3 to 2.5 moles of iridium oxide, based on 1 mole of ruthenium oxide contained in the first layer 20. The first layer 20 preferably contains from 0.3 to 8 moles, more preferably from 1 to 7 moles of titanium oxide, based on 1 mole of ruthenium oxide contained in the first layer 20. With a compositional ratio of three oxides in this Electrolysis electrode 100 exhibits excellent resistance in the range.

When the first layer 20 contains at least two of ruthenium oxide, iridium oxide and titanium oxide, these oxides preferably form a solid solution. The formation of a solid solution of the oxides allows the electrolysis electrode 100 to exhibit excellent resistance.

[0052] In addition to the above-described compositions, oxides of various compositions can be used, provided that at least one of ruthenium oxide, iridium oxide and titanium oxide is contained. For example, an oxide coating called DSA (R), which contains ruthenium, iridium, tantalum, niobium, titanium, tin, cobalt, manganese, platinum, and the like, can be used as the first layer 20.

The first layer 20 need not be a single layer and may include multiple layers. For example, the first layer 20 may include a three-oxide layer and a two-oxide layer. The thickness of the first layer 20 is preferably 0.05 to 10 µm, more preferably 0.1 to 8 µm.

[0053] (Second layer)

The second layer 30 preferably contains ruthenium and titanium. This makes it possible to further reduce the electrical overvoltage of chlorine immediately after electrolysis.

The second layer 30 preferably contains palladium oxide, a solid solution of palladium-platinum oxide, or a palladium-platinum alloy. This makes it possible to further reduce the electrical overvoltage of chlorine immediately after electrolysis.

The thicker second layer 30 can maintain the electrolysis performance for a long period of time, but from an economic standpoint, the thickness is preferably 0.05 to 3 µm.

[0054] Next, a situation will be described where the electrolysis electrode of the present embodiment is used as a cathode for conventional salt electrolysis.

(First layer)

Examples of the components of the first layer 20 as a catalyst layer include elements such as C, Si, P, S, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, In, Sn, Ta, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu, as well as metal oxides and hydroxides.

When the first layer 20 contains at least one of platinum group metals, platinum group metal oxides, platinum group metal hydroxides and alloys containing a platinum group metal, platinum group metals, platinum group metal oxides, platinum group metal hydroxides, and platinum metal containing alloys the groups preferably contain at least one platinum group metal from platinum, palladium, rhodium, ruthenium and iridium.

The platinum group metal is preferably platinum.

As the oxide of the platinum group metal, ruthenium oxide is preferably contained.

As the hydroxide of the platinum group metal, ruthenium hydroxide is preferably contained.

As an alloy of platinum group metals, an alloy of platinum with nickel, iron and cobalt is preferably included.

[0055] In addition, if necessary, an oxide or hydroxide of a lanthanide element is preferably contained as the second component. This allows the electrolysis electrode 100 to exhibit excellent resistance.

As the oxide or hydroxide of the lanthanide element, preferably at least one selected from lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium and dysprosium is contained.

In addition, if necessary, a transition metal oxide or hydroxide is preferably contained as the third component.

The addition of the third component allows the electrolysis electrode 100 to exhibit superior resistance and lower electrolysis voltage.

Examples of a preferred combination include only ruthenium, ruthenium + nickel, ruthenium + cerium, ruthenium + lanthanum, ruthenium + lanthanum + platinum, ruthenium + lanthanum + palladium, ruthenium + praseodymium, ruthenium + praseodymium + platinum, ruthenium + praseodymium + platinum + palladium, ruthenium + neodymium, ruthenium + neodymium + platinum, ruthenium + neodymium + manganese, ruthenium + neodymium + iron, ruthenium + neodymium + cobalt, ruthenium + neodymium + zinc, ruthenium + neodymium + gallium, ruthenium + neodymium + sulfur, ruthenium + neodymium + lead , ruthenium + neodymium + nickel, ruthenium + neodymium + copper, ruthenium + samarium, ruthenium + samarium + manganese, ruthenium + samarium + iron, ruthenium + samarium + cobalt, ruthenium + samarium + zinc, ruthenium + samarium + gallium, ruthenium + samarium + sulfur, ruthenium + samarium + lead, ruthenium + samarium + nickel, platinum + cerium, platinum + palladium + cerium, platinum + palladium + lanthanum + cerium, platinum + iridium, platinum + palladium, platinum + iridium + palladium, platinum + nickel + palladium, platinum + nickel + ruthenium, platinum and nickel alloys, platinum and cobalt alloys and platinum and iron alloys.

[0056] When platinum-group metals, platinum-group metal oxides, platinum-group metal hydroxides, and platinum-group metal-containing alloys are not contained, the main component of the catalyst is preferably the element nickel.

Preferably, at least one of nickel metal, nickel oxides and hydroxides is contained.

[0057] A transition metal can be added as a second component. As the second added component, at least one of titanium, tin, molybdenum, cobalt, manganese, iron, sulfur, zinc, copper and carbon is preferably contained.

Examples of a preferred combination include nickel + tin, nickel + titanium, nickel + molybdenum, and nickel + cobalt.

If necessary, an intermediate layer may be disposed between the first layer 20 and the electrolysis electrode substrate 10. By placing the intermediate layer, the resistance of the electrolysis electrode 100 can be improved.

Preferred as the intermediate layer are those which have an affinity for both the first layer 20 and the electrode substrate 10 for electrolysis. As the intermediate layer, preferred are nickel oxides, platinum group metals, platinum group metal oxides and platinum group metal hydroxides. The intermediate layer can be formed by applying and firing a solution containing the component that forms the intermediate layer. Alternatively, a surface oxide layer can also be formed by subjecting the substrate to heat treatment at a temperature of 300 to 600 ° C. in an air atmosphere. In addition, this layer can be formed by a known method such as a thermal spraying method and an ionic deposition method.

(Second layer)

[0058] Examples of the components of the first layer 30 as the catalyst layer include elements such as C, Si, P, S, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb , Mo, Ru, Rh, Pd, Ag, Cd, In, Sn, Ta, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu , Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu, as well as metal oxides and hydroxides. The first layer 30 may or may not contain at least one of platinum group metals, platinum group metal oxides, platinum group metal hydroxides, and platinum group metal containing alloys. Examples of a preferred combination of elements contained in the second layer include those listed for the first layer. The combination of the first layer and the second layer can be a combination in which the compositions are the same and the compositional ratios are different, or it can be a combination of different compositions.

[0059] With regard to the thickness of the catalyst layer, the total thickness of the formed catalyst layer and the intermediate layer is preferably 0.01 µm to 20 µm. With a thickness of 0.01 µm or more, the catalyst layer can sufficiently serve as a catalyst. With a thickness of 20 µm or less, a strong catalyst layer can be formed that is unlikely to separate from the support. The thickness is more preferably 0.05 µm to 15 µm. The thickness is more preferably 0.1 to 10 µm. Even more preferably, the thickness is 0.2 to 8 µm.

[0060] The thickness of the electrode, that is, the combined thickness of the electrolysis electrode support and the catalyst layer, is preferably 315 µm or less, more preferably 220 µm or less, further preferably 170 µm or less, even more preferably 150 µm or less, particularly preferably 145 µm or less, even more preferably 140 µm or less, even more preferably 138 µm or less, further even more preferably 135 µm or less, with respect to the workability of the electrode. A thickness of 135 µm or less can provide good workability. In addition, for similar reasons as above, the thickness is preferably 130 µm or less, more preferably less than 130 µm, even more preferably 115 µm or less, further more preferably 65 µm or less. The lower limit is not particularly limited, but is preferably 1 µm or more, more preferably 5 µm or more for practical reasons, more preferably 20 µm or more. The thickness of the electrode can be determined by measuring with a digital thickness gauge (from Mitutoyo Corporation, minimum scale 0.001 mm). The thickness of the electrode substrate for electrolysis can be measured in the same manner as the thickness of the electrode. The thickness of the catalyst layer can be determined by subtracting the thickness of the electrolysis electrode support from the thickness of the electrode.

[0061] (Method for Manufacturing Electrolysis Electrode)

Next, one embodiment of a method for manufacturing an electrode 100 for electrolysis will be described in detail.

In the present embodiment, the electrolysis electrode 100 can be obtained by forming a first layer 20, preferably a second layer 30 on the electrolysis electrode substrate by a method such as firing a coating film in an oxygen atmosphere (pyrolysis) or ion deposition, electrodeposition, or thermal sputtering. Of these, a pyrolysis method, an electrodeposition method and an ion-plating method are preferable, since the catalyst layer can be formed while preventing deformation of the electrode substrate for electrolysis. If, in addition, productivity is considered, an electrodeposition method and a pyrolysis method are further preferred. The production method of the present embodiment can achieve high formation productivity of the electrolysis electrode 100. More specifically, in the pyrolysis method, a catalyst layer is formed on the electrode support for electrolysis by an application step in which a coating liquid containing the catalyst is applied, a drying step in which the coating liquid is dried, and a pyrolysis step in which pyrolysis is performed. Pyrolysis here means that a metal salt, which is to be a precursor, decomposes by heating into a metal or metal oxide and a gaseous substance. The decomposition product depends on the nature of the metal used, the type of salt and the atmosphere in which the pyrolysis is carried out, and many metals tend to form oxides in an oxidizing atmosphere. In an industrial process for making an electrode for electrolysis, pyrolysis is usually performed in air, and in many cases a metal oxide or metal hydroxide is formed.

[0062] (Formation of the first layer of the anode)

(Application stage)

The first layer 20 is obtained by applying a solution in which at least one metal salt of ruthenium, iridium and titanium (first coating liquid) is dissolved on the electrode substrate for electrolysis, and then pyrolysis (calcining) the coating liquid in the presence of oxygen. The content of ruthenium, iridium and titanium in the first cover liquid is substantially equivalent to that in the first layer 20.

Metal salts can be chlorides, nitrates, sulfates, metal alkoxides, and any other form. The solvent of the first coating liquid can be selected depending on the type of metal salt, and water and alcohols such as butanol can be used. As the solvent, water or a mixed solvent of water and alcohol is preferred. The total metal concentration in the first coating liquid in which the metal salts are dissolved is not particularly limited, but is preferably in the range of 10 to 150 g / L in consideration of the thickness of the coating film formed by a single application.

Examples of a method used as a method for applying the first coating liquid to the electrolysis electrode substrate 10 include a method for dipping the electrolysis electrode substrate 10 into a first coating liquid, a method for applying a first coating liquid with a brush, a rolling method using a sponge roll impregnated with the first coating liquid. and an electrostatic coating method in which the electrolysis electrode substrate 10 and the first coating liquid are charged with opposite charges and sputtering is performed. Among them, a rolling method or an electrostatic coating method is preferable, which has excellent production performance on an industrial scale.

[0063] (Drying Step and Pyrolysis Step)

After applying the first coating liquid to the electrode substrate 100 for electrolysis, it is dried at a temperature of 10 to 90 ° C and subjected to pyrolysis in a roasting furnace heated to a temperature of 350 to 650 ° C. Between drying and pyrolysis, if necessary, a pre-firing can be performed at a temperature of 100 to 350 ° C. The temperature for drying, pre-firing and pyrolysis is appropriately selected depending on the composition and type of solvent of the first coating liquid. A longer period of pyrolysis time in each step is preferable, but from the viewpoint of productivity of producing an electrode, 3 to 60 minutes, more preferably 5 to 20 minutes are preferable.

The cycle of the above-described application, drying and pyrolysis is repeated to form a coating (first layer 20) to a predetermined thickness. After the first layer 20 is formed and then further post-baked for an extended period of time as required, this can further increase the stability of the first layer 20.

[0064] (Formation of the second layer of the anode)

The second layer 30, which is formed if necessary, is obtained, for example, by applying a solution containing a palladium compound and a platinum compound or a solution containing a ruthenium compound and a titanium compound (second coating liquid) on the first layer 20, and then the coating liquid is subjected to pyrolysis in presence of oxygen.

[0065] (Formation of the first cathode layer by pyrolysis method)

(Application stage)

The first layer 20 is obtained by applying a solution in which metal salts in various combinations are dissolved (first coating liquid) on an electrode substrate for electrolysis, and then pyrolysis (calcining) the coating liquid in the presence of oxygen. The metal content in the first coating liquid is substantially equivalent to that in the first layer 20.

Metal salts can be chlorides, nitrates, sulfates, metal alkoxides, and any other form. The solvent of the first coating liquid can be selected depending on the type of metal salt, and water and alcohols such as butanol can be used. As the solvent, water or a mixed solvent of water and alcohol is preferred. The total metal concentration in the first coating liquid in which the metal salts are dissolved is not particularly limited, but is preferably in the range of 10 to 150 g / L in consideration of the thickness of the coating film formed by a single application.

Examples of a method used as a method for applying the first coating liquid to the electrolysis electrode substrate 10 include a method for dipping the electrolysis electrode substrate 10 into a first coating liquid, a method for applying a first coating liquid with a brush, a rolling method using a sponge roll impregnated with the first coating liquid. and an electrostatic coating method in which the electrolysis electrode substrate 10 and the first coating liquid are charged with opposite charges and sputtering is performed. Among them, a rolling method or an electrostatic coating method is preferable, which has excellent production performance on an industrial scale.

[0066] (Drying Step and Pyrolysis Step)

After applying the first coating liquid to the electrode substrate 100 for electrolysis, it is dried at a temperature of 10 to 90 ° C and subjected to pyrolysis in a roasting furnace heated to a temperature of 350 to 650 ° C. Between drying and pyrolysis, if necessary, a pre-firing can be performed at a temperature of 100 to 350 ° C. The temperature for drying, pre-firing and pyrolysis is appropriately selected depending on the composition and type of solvent of the first coating liquid. A longer period of pyrolysis time in each step is preferable, but from the viewpoint of productivity of producing an electrode, 3 to 60 minutes, more preferably 5 to 20 minutes are preferable.

The cycle of the above-described application, drying and pyrolysis is repeated to form a coating (first layer 20) to a predetermined thickness. After the first layer 20 is formed and then further additionally fired for a long period of time as required, heating at a temperature in the range of 350 ° C to 650 ° C can further improve the stability of the first layer 20.

[0067] (Interlayer Formation)

The intermediate layer, which is formed, if necessary, is obtained, for example, by applying a solution containing a palladium compound or a platinum compound (second coating liquid) to a substrate, and then pyrolysis of the coating liquid in the presence of oxygen. Alternatively, an intermediate nickel oxide layer can be formed on the surface of the substrate by heating the substrate only, without applying a solution, at a temperature in the range from 300 ° C to 580 ° C for a time from one minute to 60 minutes.

[0068] (Formation of the first cathode layer by ion deposition)

The first layer 20 can also be formed by ion deposition.

The example comprises a method in which a substrate is fixed in a chamber and a ruthenium metal target is irradiated with an electron beam. Particles of vaporized metallic ruthenium are positively charged in the plasma in the chamber, deposited on a negatively charged substrate. The plasma atmosphere is argon and / or oxygen and ruthenium is deposited on the substrate as ruthenium oxide.

[0069] (Formation of the first cathode layer by electrodeposition)

The first layer 20 can also be formed by electrodeposition.

As an example, when the substrate is used as a cathode and is subjected to plating in an electrolyte solution containing nickel and tin, an electrolytic plating of a nickel-tin alloy can be formed.

[0070] (Formation of the first layer of the cathode by thermal spraying)

The first layer 20 can also be formed by thermal spraying.

By way of example, nickel oxide particles sprayed by plasma onto a substrate may form a catalyst bed in which nickel metal and nickel oxide are mixed.

The electrolysis electrode of the present embodiment may be combined with a membrane such as an ion exchange membrane or a microporous membrane and used. Thus, the electrode can be used as an electrode combined with a membrane. Then the work of replacing the cathode and anode is eliminated when renewing the electrode and the work efficiency is noticeably improved.

The electrolysis electrode of the present embodiment forms a laminated article with a membrane, such as an ion exchange membrane or a microporous membrane, constituting a combined membrane and an electrode, and then can make the electrolysis performance comparable to or better than that with the new electrode. The membrane is not particularly limited as long as the membrane can be laminated to the electrode, and will be described in detail below.

[0071] [Ion exchange membrane]

The ion exchange membrane has a membrane body containing a hydrocarbon polymer or a fluorine-containing polymer having an ion exchange group, and a coating layer provided on at least one surface of the membrane body. The coating layer contains particles of inorganic material and a binder, and the specific surface area of the coating layer is 0.1 to 10 m ² / g. In an ion exchange membrane having such a structure (structure), the effect of the gas evolved during electrolysis on the electrolysis performance is small, and stable electrolysis performance can be demonstrated.

The above-described ion exchange membrane contains one of either a sulfonic acid layer having an ion exchange group derived from a sulfo group (a group represented by —SO ₃ ^- , hereinafter also referred to as a “sulfonic acid group”) or a carboxylic acid layer having an ion exchange group derived from a carboxyl group (a group represented as —CO ₂ ^- , hereinafter also referred to as a “carboxylic acid group”). From the point of view of strength and dimensional stability, it is preferable to additionally include core reinforcing materials.

The inorganic material particles and the binder will be described in detail below in the coating layer description section.

[0072] Figure 2 illustrates a schematic sectional view showing one embodiment of an ion exchange membrane. The ion exchange membrane 1 has a membrane body 10 containing a hydrocarbon polymer or a fluorine-containing polymer having an ion exchange group, and coating layers 11a and 11b formed on both surfaces of the membrane body 10.

In the ion exchange membrane 1, the membrane body 10 includes a sulfonic acid layer 3 and a carboxylic acid layer 2, and core reinforcing materials 4 that increase strength and dimensional stability. An ion exchange membrane 1 including a sulfonic acid layer 3 and a carboxylic acid layer 2 is suitably used as an ion exchange membrane.

The ion exchange membrane may include one of a sulfonic acid layer and a carboxylic acid layer. The ion exchange membrane does not need to be reinforced with core reinforcing materials, and the arrangement of the core reinforcing materials is not limited to the example in FIG. 2.

[0073] (Membrane Body)

First, the membrane body 10 constituting the ion exchange membrane 1 will be described.

The body 10 of the membrane should be such that its function is to provide selective permeation of cations, and contains a hydrocarbon polymer or a fluorine-containing polymer having an ion exchange group. Its configuration and material are not particularly limited, and preferable ones can be appropriately selected.

The hydrocarbon polymer or fluorine-containing polymer having an ion exchange group in the membrane body 10 can be obtained from a hydrocarbon polymer or a fluorine-containing polymer having an ion exchange group precursor capable of forming an ion exchange group by hydrolysis or the like. More specifically, for example, after a polymer containing a fluorinated hydrocarbon backbone having a side chain that is converted to an ion exchange group by hydrolysis or the like (ion exchange group precursor) is used to obtain a precursor of the membrane body 10, and melt-processable ( below in some cases referred to as "fluorine-containing polymer (s)"), the membrane body 10 can be obtained by converting a precursor of an ion exchange group into an ion exchange group.

[0074] The fluorine-containing polymer (s) can be obtained, for example, by copolymerizing at least one monomer selected from the next first group and at least one monomer selected from the next second group and / or the next third group. The fluorine-containing polymer (s) can also be obtained by homopolymerizing one monomer selected from any of the next first group, the next second group, and the next third group.

Examples of monomers of the first group include vinyl fluoride compounds. Examples of vinyl fluoride compounds include vinyl fluoride, tetrafluoroethylene, hexafluoropropylene, vinylidene fluoride, trifluoroethylene, chlorotrifluoroethylene, and perfluoroalkyl vinyl ethers. In particular, when an ion exchange membrane is used as a membrane for alkaline electrolysis, the vinyl fluoride compound is preferably a perfluorinated monomer, and a perfluorinated monomer selected from the group consisting of tetrafluoroethylene, hexafluoropropylene and perfluoroalkyl vinyl ethers is preferred.

[0075] Examples of monomers of the second group include vinyl compounds having a functional group convertible to an ion exchange group such as a carboxylic acid (carboxylic acid group). Examples of vinyl compounds having a functional group convertible to a carboxylic acid ion exchange group include monomers represented by the formula CF ₂ = CF (OCF ₂ CYF) _s –O (CZF) _t –COOR, in which s is an integer from 0 to 2, t is an integer from 1 to 12, each of Y and Z is independently F or CF ₃ and R is a lower alkyl group (a lower alkyl group is an alkyl group having, for example, 1 to 3 carbon atoms).

Among them, preferred are compounds represented by the formula CF ₂ = CF (OCF ₂ CYF) _{n -} O (CF ₂ ) _{m -} COOR, in which n represents an integer from 0 to 2, m represents an integer from 1 to 4, Y represents F or CF ₃ and R is CH ₃ , C ₂ H _5, or C ₃ H ₇ .

When an ion exchange membrane is used as a cation exchange membrane for alkaline electrolysis, the perfluoro compound is preferably used at least as a monomer, but the alkyl group (see R values above) of the ester group is lost from the polymer during hydrolysis, and therefore the alkyl group (R) need not be a perfluoroalkyl group in which all hydrogen atoms are replaced by fluorine atoms.

[0076] Of the above monomers, the following monomers are more preferred as monomers of the second group:

CF ₂ = CFOCF ₂ –CF (CF ₃ ) OCF ₂ COOCH ₃ ,

CF ₂ = CFOCF ₂ CF (CF ₃ ) O (CF ₂ ) ₂ COOCH ₃ ,

CF ₂ = CF [OCF ₂ –CF (CF ₃ )] ₂ O (CF ₂ ) ₂ COOCH ₃ ,

CF ₂ = CFOCF ₂ CF (CF ₃ ) O (CF ₂ ) ₃ COOCH ₃ ,

CF ₂ = CFO (CF ₂ ) ₂ COOCH ₃ and

CF ₂ = CFO (CF ₂ ) ₃ COOCH ₃ .

[0077] Examples of monomers of the third group include vinyl compounds having a functional group convertible to an ion exchange group of the sulfone type (sulfonic acid group). As vinyl compounds having a functional group convertible to a sulfonic acid ion exchange group, for example, monomers represented by the formula CF ₂ = CFO — X — CF ₂ —SO ₂ F in which X is a perfluoroalkylene group are preferred. Specific examples include the following monomers:

CF ₂ = CFOCF ₂ CF ₂ SO ₂ F,

CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₂ F,

CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ CF ₂ SO ₂ F,

CF ₂ = CF (CF ₂ ) ₂ SO ₂ F,

CF ₂ = CFO [CF ₂ CF (CF ₃ ) O] ₂ CF ₂ CF ₂ SO ₂ F and

CF ₂ = CFOCF ₂ CF (CF ₂ OCF ₃ ) OCF ₂ CF ₂ SO ₂ F.

[0078] Among them, CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ CF ₂ SO ₂ F and CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₂ F are more preferable.

The copolymer obtained from these monomers can be formed by a polymerization process designed for the homopolymerization and copolymerization of ethylene fluoride, in particular by the general polymerization process used for tetrafluoroethylene. For example, in a method using a non-aqueous medium, the polymerization reaction can be carried out in the presence of a free radical polymerization initiator such as a perfluorocarbon peroxide or an azo compound, under conditions of a temperature of 0 to 200 ° C and a pressure of 0.1 to 20 MPa, using an inert solvent, such as a perfluorocarbon or a chlorofluorocarbon.

[0079] In the above copolymerization, the type of combination of the above monomers and their proportions are not particularly limited and are determined depending on the type and amount of functional groups that it is desirable to introduce into the resulting fluorine-containing polymer. For example, when a fluorine-containing polymer containing only a carboxylic acid group is produced, at least one polymer must be selected from each of the above-described first group and second group and copolymerized. In addition, when a fluorine-containing polymer containing only a sulfonic acid group is prepared, at least one polymer must be selected from each of the first group and the third group, and copolymerized. In addition, when a fluorine-containing polymer having a carboxylic acid group and a sulfonic acid group is produced, at least one monomer must be selected from each of the above-described first group, second group and third group and copolymerized. In this case, the target fluorine-containing polymer can also be obtained by separately forming a copolymer including monomers of the above-described first group and second group, and a copolymer including monomers of the above-described first group and third group, and then mixing these copolymers. The composition of the mixture of monomers is not particularly limited, and when the number of functional groups per structural unit of the polymer increases, the proportion of monomers selected from the above-described second group and third group must increase.

The total ion exchange capacity of the fluorine-containing copolymer is not particularly limited, but is preferably 0.5 to 2.0 mg-eq / g, more preferably 0.6 to 1.5 mg-eq / g. The total ion exchange capacity here refers to the equivalent of the exchange group per unit weight of dry resin and can be measured by neutralization titration or the like.

[0080] In the membrane body 10 of the ion exchange membrane 1, a sulfonic acid layer 3 containing a fluorine-containing polymer having a sulfonic acid group and a carboxylic acid layer 2 containing a fluorine-containing polymer having a carboxylic acid group are laminated. By providing the membrane body 10 having such a layer configuration, the selective permeability to cations such as sodium ions can be further improved.

The ion exchange membrane 1 is placed in the cell so that typically the sulfonic acid layer 3 is on the anode side of the cell and the carboxylic acid layer 2 is on the cathode side of the cell.

The sulfonic acid layer 3 is preferably composed of a material having a low electrical resistance and is thicker than the carboxylic acid layer 2 in terms of membrane strength. The thickness of the sulfonic acid layer 3 is preferably 2 to 25 times, more preferably 3 to 15 times the thickness of the carboxylic acid layer 2.

The carboxylic acid layer 2 preferably has high anion exclusion characteristics, even if it is thin. The anion exclusion characteristics herein refer to the characteristic of hindering the incorporation and penetration of anions into or through the ion exchange membrane 1. In order to improve the anion exclusion characteristics, it is effective to place a carboxylic acid layer having a low ion exchange capacity compared to the sulfonic acid layer.

As the fluorine-containing polymer for use in the sulfonic acid layer 3, a polymer obtained using CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₂ F is preferred as the third group monomer.

As the fluorine-containing polymer for use in the carboxylic acid layer 2, a polymer obtained using CF ₂ = CFOCF ₂ CF (CF ₂ ) O (CF ₂ ) ₂ COOCH ₃ as the second group monomer is preferable.

[0081] (Coating layer)

The ion exchange membrane has a coating layer on at least one surface of the membrane body. As shown in FIG. 2, in the ion exchange membrane 1, coating layers 11a and 11b are formed on both surfaces of the membrane body 10.

The coating layers contain particles of inorganic material and a binder.

The average particle size of the inorganic material is preferably 0.90 µm or more. When the average particle size of the inorganic material is 0.90 µm or more, impurity resistance is greatly improved in addition to gas attachment. That is, by increasing the average particle size of the inorganic material as well as keeping the above-mentioned specific surface area, a particularly noticeable effect can be achieved. Uneven particles of inorganic material are preferred insofar as the above average particle size and specific surface area are satisfied. Melted inorganic material particles and raw ore milling inorganic particles can be used. Preferably, particles of inorganic material obtained by milling raw ore are used.

The average particle size of the inorganic material may be 2 µm or less. When the average particle size of the inorganic material is 2 µm or less, damage to the membrane by the inorganic material can be prevented. The average particle size of the inorganic material is more preferably 0.90 to 1.2 µm.

Here, the average particle size can be measured with a particle size analyzer ("SALD2200", manufactured by SHIMADZU CORPORATION).

The particles of inorganic material are preferably irregular in shape. Such shapes further improve the resistance to impurities. The particles of inorganic material preferably have a wide particle size distribution.

The particles of inorganic material preferably contain at least one inorganic material selected from the group consisting of oxides of Group IV elements of the Periodic Table (chemical elements), nitrides of Group IV elements of the Periodic Table, and carbides of Group IV elements of the Periodic Table. From the standpoint of resistance, zirconium oxide particles are more preferable.

Particles of inorganic material are preferably particles of inorganic material obtained by grinding raw ore from particles of inorganic material, or particles of inorganic material in the form of spherical particles having a uniform diameter, obtained by refining a melt of raw ore from particles of inorganic material

[0082] Examples of means for grinding raw ore include, but are not specifically limited to, ball mills, bead mills, colloid mills, cone grinders, disk mills, runners, grain mills, hammer mills, granulators, vertical shaft impact crushers (VSI ), leather mills (Wiley mills), roller mills and jet mills. After grinding, the particles are preferably washed. As a washing method, the particles are preferably treated with an acid. This treatment can reduce the amount of impurities such as iron adhered to the surface of the inorganic material particles.

The coating layer preferably contains a binder. The binder is the component that forms the coating layers by retaining particles of inorganic material on the surface of the ion exchange membrane. The binder preferably contains a fluorine-containing polymer from the standpoint of resistance to electrolyte solution and electrolysis products.

[0083] As a binder, a fluorine-containing polymer having a carboxylic acid group or a sulfonic acid group is more preferable in terms of resistance to electrolyte solution and electrolysis products and adhesion strength to the surface of the ion exchange membrane. When the coating layer is provided on the layer containing the fluorine-containing polymer having a sulfonic acid group (sulfonic acid layer), the fluorine-containing polymer having a sulfonic acid group is even more preferably used as the tie layer of the coating. Alternatively, when the coating layer is provided on a layer containing a fluorine-containing polymer having a carboxylic acid group (carboxylic acid layer), a fluorine-containing polymer having a carboxylic acid group is more preferably used as the tie layer of the coating.

The content of the particles of inorganic material in the coating layer is preferably 40 to 90% by mass, more preferably 50 to 90% by mass. The content of the binder is preferably 10 to 60% by mass, more preferably 10 to 50% by mass.

The distribution density of the coating layer in the ion exchange membrane is preferably 0.05 to 2 mg per cm ² . When the ion exchange membrane has ridges (roughness) on its surface, the distribution density of the coating layer is preferably 0.5 to 2 mg per cm ² .

As a method for manufacturing the coating layer, which is not particularly limited, a known method can be applied. An example is a method comprising applying by spray or the like a coating liquid obtained by dispersing particles of an inorganic material in a solution containing a binder.

[0084] (Core Reinforcement Materials)

The ion exchange membrane preferably has core reinforcing materials disposed within the membrane body.

Core reinforcement materials are elements that increase the strength and dimensional stability of the ion exchange membrane. By placing the reinforcing materials of the core within the body of the membrane, it is possible, in particular, to control the expansion and contraction of the ion exchange membrane in the desired range. Such an ion exchange membrane does not expand or contract more than necessary during electrolysis and the like, and can maintain excellent dimensional stability for a long time.

The configuration of the core reinforcing materials is not particularly limited, and, for example, the core reinforcing materials may be formed by woven yarns (filaments) called reinforcing yarns. Reinforcing yarns herein refer to yarns that constitute the constituent core reinforcing materials, can provide the desired dimensional stability and mechanical strength to the ion exchange membrane, and can be stably present in the ion exchange membrane. By using core reinforcing materials obtained by weaving such reinforcing yarns, better dimensional stability and mechanical strength can be imparted to the ion exchange membrane.

The material for the reinforcing materials of the core and the reinforcing yarns used therefor is not particularly limited, but is preferably a material resistant to acids, alkalis, etc., and a fiber including a fluorine-containing polymer is preferable since long-term heat resistance and chemical resistance are required.

Examples of the fluoropolymer used in core reinforcing materials include polytetrafluoroethylene (PTFE), copolymers of tetrafluoroethylene and perfluoroalkyl vinyl ethers (PFA), copolymers of tetrafluoroethylene and ethylene (ETFE), copolymers of tetrafluoroethylene and trifluoroethylene copolymers and copolymers of tetrafluoroethylene and trifluoroethylene copolymers and hexafluoroethylene copolymers. Among them, fibers including polytetrafluoroethylene are preferably used in terms of heat resistance and chemical resistance.

The diameter of the reinforcing yarns used for the core reinforcing materials is not particularly limited, but is preferably 20 to 300 denier, more preferably 50 to 250 denier. The weave density (web density per unit length) is preferably 5 to 50 / inch. The shape of the core reinforcing materials is not particularly limited, for example, woven fabric, non-woven fabric and knitted fabric are used, but preferably in the form of woven fabric. The thickness of the woven fabric used is preferably 30 to 250 µm, more preferably 30 to 150 µm.

As the woven fabric or knitted fabric, monofilaments, multifilaments or yarns thereof, twisted yarns with broken threads or the like can be used, and various types of weaving methods can be used such as plain weave, leno weave, knitted weave, cord weave and seersucker.

[0085] The braiding and placement of the core reinforcing materials in the membrane body are not particularly limited, and the preferred placement can be appropriately provided in consideration of the size and shape of the ion exchange membrane, physical properties desired for the ion exchange membrane, environmental conditions in use, and the like.

For example, the core reinforcing materials may be placed along a predetermined direction of the membrane body, but from a dimensional stability point of view, it is preferable that the core reinforcing materials are placed along the predetermined first direction and other core reinforcing materials are placed along a predetermined second direction substantially perpendicular to the first. direction. By placing multiple core reinforcement materials substantially orthogonal within the membrane body, better dimensional stability and mechanical strength in many directions can be imparted. For example, a configuration is preferable in which core reinforcing materials disposed along the longitudinal direction (warp yarns) and core reinforcing materials disposed along the transverse direction (weft yarns) are woven on the surface side of the membrane body. A more preferred configuration is in the form of a plain weave made and woven by allowing the warp and weft yarns to pass alternately above and below each other, a leno weave in which two base strands are woven into the weft strands in a twist, a matting weave made and woven by inserting the same number of weft yarns or the like into two or more parallel warp yarns, or the like, from the standpoint of dimensional stability, mechanical strength and ease of manufacture.

[0086] It is particularly preferred that the core reinforcing materials are disposed along both directions MD (longitudinal direction) and TD (transverse direction) of the ion exchange membrane. In other words, the core reinforcing materials are preferably plain weave in MD and TD. Here, MD means the direction in which the membrane body and various core materials (for example, reinforcing core materials, reinforcing yarns and consumable yarns described later) move in the later described stage of obtaining the ion exchange membrane (flow direction), and TD means a direction substantially perpendicular to MD ... The yarns weaved along the MD are called MD yarns, and the yarns weaved along the TD are called TD yarns. Typically, the ion exchange membrane used for electrolysis is rectangular, and in many cases, the longitudinal direction is MD and the width direction is TD. By weaving reinforcing core materials that are MD yarns and reinforcing core materials that are TD yarns, better dimensional stability and mechanical strength can be achieved in many directions.

The placement range of the core reinforcing materials is not particularly limited, and the preferred placement can be appropriately provided in consideration of the physical properties desired for the ion exchange membrane, the environmental conditions in use, and the like.

The opening ratio (open porosity ratio) of the core reinforcing materials is not particularly limited, but is preferably 30% or more, more preferably 50% or more and 90% or less. The opening ratio is preferably 30% or more in terms of the electrochemical characteristics of the ion exchange membrane, and preferably 90% or less in terms of the mechanical strength of the ion exchange membrane.

The relative aperture (coefficient of open porosity) for core reinforcing materials here refers to the ratio (B / A) of the total surface area (B) through which substances such as ions (electrolyte solution and contained cations (e.g. sodium ions) can pass) ), to the area (A) of any one surface of the body of the ion-exchange membrane. The total surface area (B) through which substances such as ions can pass may refer to the total areas of regions in which cations, electrolyte solution and the like are not retained in the ion exchange membrane by the reinforcing materials of the core and the like contained in the ion exchange membrane. membrane.

[0087] Figure 3 illustrates a schematic view for explaining the opening ratio (open porosity ratio) of the core reinforcing materials constituting the ion exchange membrane. Figure 3, in which part of the ion exchange membrane is shown enlarged, shows only the configuration of the reinforcing materials 21 and 22 of the core in these regions, without showing other elements.

By subtracting the total area (C) of the core reinforcing materials from the area of the region surrounded by the core reinforcing materials 21 located along the longitudinal direction and the core reinforcing materials 22 located along the transverse direction, the area including the area (A) of the core reinforcing materials can be obtained. area (B) of areas through which substances such as ions can pass in area (A) of the above-described area. That is, the relative aperture can be determined by the following formula (I):

Relative aperture = (B) / (A) = ((A) - (C)) / (A) (I)

[0088] Among the reinforcing materials of the core, a particularly preferred form is film textile yarns or highly oriented monofilaments including PTFE in terms of chemical resistance and heat resistance. More specifically, more preferred are plain weave core reinforcing materials using 50 to 300 denier film textile yarns (yarns) obtained by cutting a PTFE-containing high strength porous sheet into ribbon-shaped fragments, or comprising highly oriented PTFE monofilaments with a size of from 50 to 300 denier, and which have a weave density of 10 to 50 threads (yarns) or monofilaments per inch and have a thickness in the range from 50 to 100 microns. The opening ratio of the ion exchange membrane including such core reinforcing materials is more preferably 60% or more.

Examples of the shape of the reinforcing yarns include round yarns and film yarns (yarns).

[0089] (Through holes)

The ion exchange membrane preferably has through holes within the membrane body.

Through holes refer to holes that can form channels for the ions generated during electrolysis and for the electrolyte solution. Through holes, which are tubular holes formed within the membrane body, are formed by dissolving the core consumables (or consumable yarns) described below. The shape, diameter, or the like of the through holes can be controlled by selecting the shape or diameter of the core consumable materials (the consumable yarns).

The formation of through holes inside the ion exchange membrane can provide mobility of the electrolyte solution during electrolysis. The shape of the through holes is not particularly limited, but may be the shape of the core consumable materials used to form the through holes according to the production method described below.

The through holes are preferably formed to alternately pass on the anode side (sulfonic acid layer side) and cathode side (carboxylic acid layer side) of the core reinforcing materials. With this arrangement, in the region in which the through holes are formed on the cathode side of the core reinforcing materials, ions (such as sodium ions) supplied by the electrolyte solution filling the through holes can also flow to the cathode side of the core reinforcing materials. As a result, the flow of cations is not interrupted, and thus an additional reduction in the electrical resistance of the ion-exchange membrane is possible.

The through holes may be formed along only one predetermined direction of the membrane body constituting the ion exchange membrane, but are preferably formed along both the longitudinal direction and the transverse direction of the membrane body in terms of exhibiting more stable electrolysis characteristics.

[0090] [Manufacturing Method]

A suitable example of a method for manufacturing an ion exchange membrane includes a method comprising the following steps (1) to (6):

Step (1): a step for producing a fluorine-containing polymer having an ion exchange group or an ion exchange group precursor capable of forming an ion exchange group by hydrolysis.

Step (2): a step of weaving at least a plurality of core reinforcing materials, if necessary, and consumable yarns that dissolve in acid or alkali and form through holes, to obtain a reinforcing material in which the consumable yarns are interposed between the core reinforcing materials, being adjacent to each other.

Step (3): a step of converting into a film the above fluorine-containing polymer having an ion exchange group or an ion exchange group precursor capable of forming an ion exchange group by hydrolysis.

Step (4): the step of introducing the above reinforcing materials, if necessary, into the above film to obtain a membrane body, inside which the reinforcing materials are placed.

Stage (5): stage of hydrolysis of the membrane body obtained in stage (4) (stage of hydrolysis) and

Step (6): The step of creating a coating layer on the membrane body obtained in step (5) (application step).

[0091] Next, each of the steps will be described in detail.

Stage (1): obtaining a fluorine-containing polymer

In step (1), the monomeric starting materials described above in groups one to three are used to prepare the fluoropolymer. To regulate the ion-exchange capacity of the fluorine-containing polymer, the composition of the mixture of the starting monomer materials must be controlled during the production of the fluorine-containing polymer forming the said layers.

[0092] Step (2): a step of obtaining reinforcing materials

The reinforcing material is a woven fabric obtained by weaving reinforcing yarns or the like. The reinforcing material is embedded in the membrane to thereby form core reinforcing materials. When an ion-exchange membrane with through holes is formed, consumable yarns are additionally woven into the reinforcing material. The amount of consumable yarns contained in this case is preferably 10 to 80% by mass, more preferably 30 to 70% by mass, based on the total reinforcing material. The weaving of the consumable yarns can also prevent slippage of the yarns of the core reinforcing materials.

Viscose, polyethylene terephthalate (PET), cellulose, polyamide and the like are used as consumable yarns, which are dissolved at the stage of obtaining a membrane or in an electrolysis environment. Also preferred are monofilaments or multifilaments having a thickness of 20 to 50 denier and including polyvinyl alcohol and the like.

In step (2), the aperture ratio, the placement of the through holes, and the like can be adjusted by adjusting the placement of the core reinforcing materials and the yarns consumed.

[0093] Step (3): Film forming step

In step (3), the fluoropolymer obtained in step (1) is formed into a film using an extruder. The film may have a single layer configuration, a two layer configuration of a sulfonic acid layer and a carboxylic acid layer as mentioned above, or a multilayer configuration of three or more layers.

Examples of the film forming method include the following:

a method in which a fluorine-containing polymer having a carboxylic acid group and a fluorine-containing polymer having a sulfonic acid group are separately formed into films; and

a method in which a fluorine-containing polymer having a carboxylic acid group and a fluorine-containing polymer having a sulfonic acid group are coextruded to form a composite film.

The number of each film can be more than one. Co-extrusion of different films is preferred because of their contribution to the increase in bond strength at the interface.

[0094] Step (4): the step of obtaining the membrane body

In step (4), the reinforcing material obtained in step (2) is embedded in the film obtained in step (3) to form a membrane body containing the reinforcing material.

Preferred examples of a method for forming a membrane body include (i) a method in which a fluorine-containing polymer having a precursor of a carboxylic acid group (e.g., a carboxylate functional group) (hereinafter referred to as a first layer) disposed on the cathode side, and a fluorine-containing polymer having a precursor sulfonic acid groups (e.g., sulfonyl fluoride functionality) (hereinafter referred to as the second layer) are coextruded into a film and, if necessary using a heat source and a vacuum source, the reinforcing material and composite film from the second layer / first layer are laminated in this order, onto an air-permeable, heat-resistant release paper on a flat plate or drum having multiple pores on its surface, and combined at a temperature at which each polymer is melted while evacuating air from under each of the layers by means of reduced pressure; and (ii) a method in which, in addition to the composite film of the second layer / first layer, a fluorine-containing polymer having a precursor of a sulfonic acid group is separately preformed into a film (third layer), and optionally using a heat source and a source vacuum, the third layer film, the core reinforcing materials and the composite film from the second layer / first layer are laminated in this order on a breathable heat-resistant release paper on a flat plate or drum having multiple pores on their surface and combined at a temperature at which each polymer is melted while pumping air out from under each of the layers by means of reduced pressure.

Co-extrusion of the first and second layers here helps to increase the bond strength at the interface.

The method of combining under reduced pressure is characterized by making the third layer on the reinforcing material thicker than in the press-applied method. In addition, since the reinforcing material is fixed to the inner surface of the membrane body, the method provides sufficient retention of the mechanical strength of the ion exchange membrane.

Variants of the layering methods described herein are exemplary, and coextrusion can be performed after the preferred layering configuration (eg, a combination of layers) is appropriately selected based on the desired configurations of the layers of the membrane body and physical properties, and the like.

In order to further improve the electrical characteristics of the ion exchange membrane, it is also possible to additionally place a fourth layer comprising a fluorine-containing polymer having both a precursor of a carboxylic acid group and a precursor of a sulfonic acid group between the first layer and the second layer, or using a fourth layer comprising a fluorine-containing polymer, having both a precursor of a carboxylic acid group and a precursor of a sulfonic acid group instead of the second layer.

The method for forming the fourth layer may be a method in which a fluorine-containing polymer having a precursor of a carboxylic acid group and a fluorine-containing polymer having a precursor of a sulfonic acid group are separately prepared and then mixed, or it may be a method in which a monomer having a precursor is copolymerized a carboxylic acid group; and a monomer having a sulfonic acid precursor.

When the fourth layer is used as a component of the ion exchange membrane, a coextruded film of the first layer and the fourth layer is formed, in addition, the third layer and the second layer are separately formed into films, and laminating can be performed in the above manner. Alternatively, three layers of the first layer / fourth layer / second layer can be coextruded simultaneously to form a film.

[0095] In this case, the direction in which the extruded film flows out is MD. As mentioned above, it is possible to form a membrane body containing a fluorine-containing polymer having an ion exchange group on the reinforcing material.

In addition, the ion exchange membrane preferably has protrusions constituted by a fluoropolymer having a sulfonic acid group, that is, protrusions on the side of the surface constituted by the sulfonic acid layer. As a method for forming such protrusions, which is not particularly limited, a known method including forming protrusions on a resin surface can also be applied. A specific example of the method is a method for embossing the surface of a membrane body. For example, the aforementioned protrusions can be formed using the pre-embossed release paper when the above composite film, reinforcing material, and the like are combined. In the case where the protrusions are formed by embossing, the height and density of the protrusions can be controlled by the shape of the transferred relief (the shape of the release paper).

[0096] (5) Step of hydrolysis

At step (5), the stage of hydrolysis of the membrane body obtained at stage (4) is performed to convert the precursor of the ion-exchange group into an ion-exchange group (stage of hydrolysis).

In step (5), it is also possible to dissolve holes in the membrane body by dissolving and removing consumable yarns introduced into the membrane body by the action of an acid or alkali. The consumable yarns can remain in the through holes without being completely dissolved and removed. The consumable yarns remaining in the through holes can be dissolved and removed by the electrolyte solution when the ion exchange membrane is subjected to electrolysis.

The consumable yarn is dissolved in acid or alkali at the stage of obtaining the ion-exchange membrane or in the electrolysis environment. The consumable yarns are washed out, thereby forming the through-holes at the appropriate locations.

Step (5) can be performed by immersing the membrane body obtained in step (4) in a hydrolyzing solution containing an acid or alkali. An example of a hydrolysis solution that can be used is a mixed solution containing KOH and dimethyl sulfoxide (DMSO).

[0097] The mixed solution preferably contains KOH at normal concentration from 2.5 to 4.0 and DMSO from 25 to 35% by weight.

The hydrolysis temperature is preferably 70 to 100 ° C. The higher the temperature, the greater the apparent (visible) thickness can be. The temperature is more preferably 75 to 100 ° C.

The duration of the hydrolysis is preferably 10 to 120 minutes. The longer the hydrolysis, the greater the apparent (visible) thickness can be. The duration of the hydrolysis is preferably 20 to 120 minutes.

The step of forming the through holes by washing out the sacrificial yarns will now be described in more detail. Figures 4 (a) and (b) are schematic views for explaining a method of forming vias in an ion exchange membrane.

[0098] Figures 4 (a) and (b) show reinforcing yarns 52, sacrificial yarns 504a, and through holes 504 formed by sacrificial yarns 504a alone, without illustrating other features such as a membrane body.

First, the reinforcing yarns 52, which are to constitute the core reinforcing materials in the ion exchange membrane, and the consumable yarns 504a for forming the through holes 504 in the ion exchange membrane are used as interlaced reinforcing materials. Then, in step (5), the consumable yarns 504a are washed out to form the through holes 504.

The above method is simple, since the method of interlacing reinforcing yarns 52 and consumable yarns 504a can be adjusted depending on the order of placement of the reinforcing materials of the core and the through holes in the body of the ion exchange membrane.

Figure 4 (a) shows an example of a plain weave reinforcing material in which the reinforcing yarns 52 and the sacrificial yarns 504a are interlaced in both the longitudinal direction and the transverse direction in the paper, and optionally the order of placement of the reinforcing yarns 52 and the sacrificial yarns 504a in reinforcing material can be changed.

[0099] (6) Application Step

In step (6), a coating layer can be formed by preparing a coating liquid containing particles of inorganic material obtained by grinding raw ore or melting raw ore and a binder, applying a coating liquid to the surface of the ion exchange membrane obtained in step (5), and drying the coating liquids.

A preferred binder is a binder obtained by hydrolysis of a fluoropolymer having an ion exchange group precursor with an aqueous solution containing dimethyl sulfoxide (DMSO) and potassium hydroxide (KOH), and then immersing the polymer in hydrochloric acid to replace the counterion of the ion exchange group with an H ⁺ ion (e.g. polymer having a carboxyl group or sulfo group). Thus, the polymer is more likely to dissolve in water or ethanol, as mentioned below, which is preferred.

This binder dissolves in a mixed solution of water and ethanol. The volume ratio between water and ethanol is preferably 10: 1 to 1:10, more preferably 5: 1 to 1: 5, even more preferably 2: 1 to 1: 2. The particles of inorganic material are dispersed in the dissolving liquid by means of a ball mill, thereby forming a coating liquid. In this case, it is also possible to correct the average particle size and the like of particles by adjusting the duration and speed of rotation during dispersion. The preferred amount of the mixed particles of inorganic material and binder is as mentioned above.

The concentration of the particles of inorganic material and binder in the coating liquid is not particularly limited, but a free-flowing coating liquid is preferable. This makes it possible to uniformly apply the ion exchange membrane to the surface.

In addition, a surfactant can be added to the dispersion when particles of inorganic material are dispersed. As the surfactant, nonionic surfactants are preferred and examples include HS-210, NS-210, P-210 and E-212 from NOF CORPORATION.

The resulting coating liquid is applied to the surface of the ion exchange membrane by spray application or roller coating, thereby forming an ion exchange membrane.

[0100] [Microporous Membrane]

The microporous membrane of the present embodiment is not particularly limited as long as the membrane can be formed to form an electrode laminated article for electrolysis as mentioned above. A variety of microporous membranes can be used.

The porosity of the microporous membrane of the present embodiment is not particularly limited, but may be, for example, 20 to 90, and preferably 30 to 85. The above porosity can be calculated by the following formula:

Porosity = (1– (dry weight of the membrane) / (weight calculated from the volume, calculated from the values of the thickness, width and length of the membrane, and the density of the membrane material)) × 100

[0101] The average pore size in the microporous membrane of the present embodiment is not particularly limited and may be, for example, 0.01 µm to 10 µm, preferably 0.05 µm to 5 µm. With regard to the average pore size, for example, the membrane is cut vertically in the direction of thickness, and the cross section is examined by field emission scanning electron microscopy (FE-SEM). The average pore size can be obtained by measuring the diameter of about 100 pores and averaging the results.

The thickness of the microporous membrane of the present embodiment is not particularly limited and may be, for example, 10 µm to 1000 µm, preferably 50 µm to 600 µm. The above thickness can be measured using, for example, a micrometer (manufactured by Mitutoyo Corporation) or the like.

Specific examples of a microporous membrane as above include Zirfon Perl UTP 500 manufactured by Agfa (also referred to as a Zirfon membrane in this embodiment) and are described in International Publication No. WO 2013-183584 and International Publication No. WO 2016-203701.

[0102] [Laminate Product]

The laminated article of the present embodiment comprises an electrolysis electrode of the present embodiment and a membrane or a supply conductor in contact with the electrolysis electrode. The laminated article of the present embodiment, configured as described above, can improve the operating efficiency during the renewal of the electrode in the electrolytic cell, and in addition, can exhibit excellent electrolysis performance even after the renewal.

That is, according to the layered article of the present embodiment, when renewing the electrode, the electrode can be renewed as simple as renewing the membrane without complicated work such as disassembling the electrode attached to the electrolytic cell, and thereby noticeably improve the working efficiency.

In addition, according to the layered article of the present embodiment, it is possible to maintain an electrolysis productivity comparable to that with a new electrode, or improve the electrolysis productivity. Even in the case where only the supply conductor is placed in the new electrolytic cell (i.e., an electrode not containing the catalyst bed is placed), only the connection of the electrolysis electrode of the present embodiment to the supply conductor enables the electrode to function. Thus, appreciable reduction or elimination of the catalytic coating can also be possible.

[0103] The laminated article of the present embodiment can be stored or transported to consumers in a state where the laminated article is wound around a vinyl chloride pipe or the like (in a wound state or the like), greatly facilitating handling.

As the supply conductor of the present embodiment, various substrates mentioned below, such as a worn electrode (i.e., an existing electrode) and an electrode not having a catalytic coating, can be used.

In the laminated article of the present embodiment, the force applied per unit mass unit area of the electrolysis electrode on the membrane or supply conductor is preferably 0.08 N / (mg cm ² ) or more, more preferably 0.1 N / (mg · Cm ² ) or more, even more preferably 0.14 N / (mg · cm ² ) or more, or even more preferably, from the point of view of further simplification of loading and unloading at a large size (for example, 1.5 m × 2.5 m) is 0.2 N / (mg · cm ² ) or more. The upper limit is not particularly limited, but is preferably 1.6 N / (mg cm ² ) or less, more preferably less than 1.6 N / (mg cm ² ), further preferably 1.5 N / (mg cm 2) ² ), even more preferably 1.2 N / (mg · cm ² ) or less, even more preferably 1.20 N / (mg · cm ² ) or less. The upper limit value is even more preferably 1.1 N / (mg cm ² ) or less, further even more preferably 1.10 N / (mg cm ² ) or less, particularly preferably 1.0 N / (mg · Cm ² ) or less, particularly preferably 1.00 N / (mg · cm ² ) or less.

[0104] [Winding]

The winding of the present embodiment comprises an electrolysis electrode of the present embodiment or a laminated article of the present embodiment. That is, the winding of the present embodiment is obtained by winding the electrolysis electrode of the present embodiment or the laminated article of the present embodiment. Reducing the size of the electrolysis electrode of the present embodiment or the laminated article of the present embodiment by winding as the winding of the present embodiment can further improve workability.

[0105] [Electrolyzer]

The electrolyzer of the present embodiment comprises an electrode for electrolysis of the present embodiment. Next, a case of performing conventional salt electrolysis using an ion exchange membrane as the membrane will be given by way of example, and one embodiment of the electrolytic cell will be described in detail.

[0106] [Electrolytic Cell]

Figure 5 illustrates a sectional view of an electrolytic cell 1.

The electrolytic cell 1 contains an anode chamber 10, a cathode chamber 20, a dividing wall 30 located between the anode chamber 10 and the cathode chamber 20, an anode 11 located in the anode chamber 10, and a cathode 21 located in the cathode chamber 20. If necessary, an electrolytic cell 1 has a substrate 18a and a reverse current absorbing layer 18b formed on the substrate 18a, and may include a reverse current absorber 18 disposed in the cathode chamber. The anode 11 and the cathode 21, which are part of the electrolytic cell 1, are electrically connected to each other. In other words, the electrolytic cell 1 contains the following cathode structure. The cathode structure 40 comprises a cathode chamber 20, a cathode 21 disposed in the cathode chamber 20, and a reverse current absorber 18 disposed in the cathode chamber 20, the reverse current absorber 18 having a substrate 18a and a reverse current absorbing layer 18b formed on the substrate 18a as shown in Figure 9, and the cathode 21 and the reverse current absorbing layer 18b are electrically connected. In addition, the cathode chamber 20 has a current collector 23, a holder 24 supporting the current collector, and a metal elastic body 22. The metal elastic body 22 is placed between the current collector 23 and the cathode 21. The holder 24 is located between the current collector 23 and the partition 30. The current collector 23 is electrically connected to cathode 21 through the metal elastic body 22. The separating wall 30 is electrically connected to the current collector 23 through the holder 24. Accordingly, the separating wall 30, the holder 24, the current collector 23, the metal elastic body 22 and the cathode 21 are electrically connected to each other. The cathode 21 and the reverse current absorbing layer 18b are electrically connected. The cathode 21 and the reverse current absorbing layer may be connected directly, or may be connected indirectly through a down conductor, a holder, a metal resilient body, a baffle, or the like. The entire surface of the cathode 21 is preferably coated with a catalyst layer for the reduction reaction. The form of the electrical connection may be a form in which the baffle 30 and the support 24, the support 24 and the collector 23 and the collector 23 and the metal resilient body 22 are in each case directly connected to each other, and the cathode 21 is laminated on the metal resilient body 22. Examples methods for directly attaching these structural elements to each other include welding and the like. Alternatively, the reverse current absorber 18, cathode 21, and current collector 23 may be collectively referred to as cathode structure 40.

[0107] Figure 6 illustrates a cross-sectional view of two electrolytic cells 1 that are adjacent in electrolytic cell 4. Figure 7 shows electrolytic cell 4. Figure 8 shows a step of assembling electrolytic cell 4. As shown in Figure 6, electrolytic cell 1, cation exchange membrane 2 and electrolytic cell 1 are placed sequentially in the order shown. The ion exchange membrane 2 is placed between the anode chamber of one electrolytic cell 1 of two electrolytic cells that are adjacent (adjacent) in the electrolyzer, and the cathode chamber of another electrolytic cell 1. That is, the anode chamber 10 of the electrolytic cell 1 and the cathode chamber 20 of the adjacent electrolytic cell 1 are separated by a cation exchange membrane 2. As shown in Figure 7, the electrolyzer 4 consists of a plurality of electrolytic cells 1 connected in series through an ion exchange membrane 2. That is, the electrolyzer 4 is a bipolar electrolyzer including a plurality of electrolytic cells 1 and ion exchange membranes 2 arranged in series. in each case, placed between adjacent electrolytic cells 1. As shown in Figure 8, the electrolytic cell 4 is assembled by placing a plurality of electrolytic cells 1 in series connection through the ion exchange membrane 2 and bonding the cells by means of a clamping device 5.

[0108] Electrolyzer 4 has an anode lead 7 and a cathode lead 6 that are connected to a power supply. An anode 11 of an electrolytic cell 1 located at the farthest end of a plurality of electrolytic cells 1 connected in series in an electrolysis cell 4 is electrically connected to an anode terminal 7. A cathode 21 of an electrolytic cell located at an end opposite to the anode terminal 7 among the plurality of electrolytic cells 1, connected in series in the electrolytic cell 4, electrically connected to the cathode terminal 6. Electric current during electrolysis flows from the side of the anode terminal 7 through the anode and the cathode of each electrolytic cell 1 towards the cathode terminal 6. At both ends of the connected electrolytic cells 1 there may be an electrolytic cell, having only an anode chamber (anode outlet cell), and an electrolytic cell having only a cathode chamber (cathode outlet cell). In this case, the anode terminal 7 is connected to an anode terminal cell located at one end, and the cathode terminal 6 is connected to a cathode terminal cell located at the other end.

In the case of brine electrolysis, brine is supplied to each anode chamber 10, and pure water or low-concentration aqueous sodium hydroxide solution is supplied to each cathode chamber 20. Each liquid is supplied from an electrolyte solution supply pipe (not shown in the figure) through an electrolyte solution supply hose. (not shown in the figure) to each electrolytic cell 1. The electrolyte solution and electrolysis products are removed from the pipe for removing the electrolyte solution (not shown in the figure). During electrolysis, sodium ions in the brine migrate from the anode chamber 10 of one electrolytic cell 1 through the ion exchange membrane 2 to the cathode chamber 20 of the adjacent electrolytic cell 1. Thus, the electric current during electrolysis flows in the direction in which the electrolytic cells 1 are connected in series. That is, an electric current flows through the cation exchange membrane 2 from the anode chamber 10 towards the cathode chamber 20. When the brine is electrolyzed, chlorine gas is generated on the anode 11 side, and sodium hydroxide (dissolved) and hydrogen gas are generated on the cathode 21 side.

[0109] (Anode chamber)

The anode chamber 10 has an anode 11 or an anode supply conductor 11. When the electrolysis electrode of the present embodiment is inserted on the anode side, 11 serves as an anode supply conductor. When the electrolysis electrode of the present embodiment is not inserted on the anode side, 11 serves as an anode. The anode chamber 10 has an anode side electrolyte solution supply unit that supplies electrolyte solution to the anode chamber 10, a baffle plate that is positioned above the anode side electrolyte solution supply unit so as to be substantially parallel or inclined with respect to the dividing wall 30, and a gas-liquid an anode-side separator located above the baffle plate for separating the gas from the electrolyte solution including the admixed gas.

[0110] (Anode)

When the electrolysis electrode of the present embodiment is not inserted on the anode side, the anode 11 is in the frame of the anode chamber 10. A metal electrode such as a so-called DSA (R) can be used as the anode 11. DSA is an electrode including a titanium substrate, the surface of which is coated with an oxide including ruthenium, iridium and titanium as components.

As for the shape, any of a perforated metal sheet, a nonwoven fabric, a porous metal, an expanded metal sheet, an electrospinning metal porous foil, a so-called woven metal mesh formed by interlacing of thin metal filaments, and the like can be used.

[0111] (Anode supply conductor)

When the electrode for electrolysis of the present embodiment is inserted on the anode side, an anode supply conductor 11 is provided on the frame of the anode chamber 10. A metal electrode such as a so-called DSA (R) can be used as the anode supply conductor 11, and can also be used titanium without catalytic coating. Alternatively, a DSA having a thinner catalytic coating can also be used. In addition, an already used anode can also be used.

As for the shape, any of a perforated metal sheet, a nonwoven fabric, a porous metal, an expanded metal sheet, an electrospinning metal porous foil, a so-called woven metal mesh formed by interlacing of thin metal filaments, and the like can be used.

[0112] (Anode side electrolyte solution supply unit)

An anode-side electrolyte solution supply unit that supplies an electrolyte solution to the anode chamber 10 is connected to a pipe for supplying an electrolyte solution. The anode side electrolyte solution supply unit is preferably disposed under the anode chamber 10. As the anode side electrolyte solution supply unit, for example, a pipe on the surface of which lumen portions (dispersion tube) and the like can be used. Such a tube is more preferably located along the surface of the anode 11 and parallel to the bottom 19 of the electrolytic cell. This pipe is connected to a pipe for supplying an electrolyte solution (a liquid supply pipe), which supplies an electrolyte solution to an electrolytic cell 1. The electrolyte solution supplied from a liquid supply pipe is passed through a pipe into an electrolytic cell 1 and is fed from holes made on the pipe surface inside the anode chambers 10. Placing the pipe along the surface of the anode 11 and parallel to the bottom 19 of the electrolytic cell is preferable because the electrolyte solution can be uniformly supplied to the inside of the anode chamber 10.

[0113] (Anode side gas-liquid separator)

The anode-side gas-liquid separator is preferably located above the baffle plate. The purpose of the anode side gas-liquid separator is to separate the generated gas, such as chlorine, from the electrolyte solution during electrolysis. Unless otherwise specified, "above" means an upward direction in an electrolytic cell 1 in FIG. 5, and "under" means a downward direction in an electrolytic cell 1 in FIG. 5.

The gas generated during electrolysis, evolved in the electrolytic cell 1, and the electrolyte solution form a mixed phase (gas-liquid mixed phase), which is then discharged from the system. As a consequence, pressure fluctuations within the electrolytic cell 1 cause vibration, which can lead to physical damage to the ion exchange membrane. To prevent this phenomenon, the electrolytic cell 1 of the present embodiment is preferably equipped with an anode-side gas-liquid separator for separating gas from liquid. The anode-side gas-liquid separator is preferably provided with a defoamer plate to eliminate bubbles. When the gas-liquid mixed phase stream flows through the defoamer plate, the bubbles burst, thereby separating the electrolyte solution and gas. As a result, vibration during electrolysis can be prevented.

[0114] (Baffle plate)

The baffle plate is preferably positioned above the anode side electrolyte solution supply unit and is positioned substantially parallel or obliquely with respect to the baffle 30. The baffle plate is a baffle plate that controls the flow of electrolyte solution into the anode chamber 10. When the baffle plate is provided, it can cause circulation electrolyte solution (brine or the like) inside the anode chamber 10, thereby making the concentration more uniform. To create internal circulation, the baffle plate is preferably positioned so as to separate the space near the anode 11 from the space near the baffle 30. For this reason, the baffle plate is preferably positioned so that it is opposite the surface of the anode 11 and the surface of the baffle 30. In the space near the anode separated by the baffle plate, electrolysis occurs, the concentration of the electrolyte solution (brine concentration) decreases, and a generated gas such as chlorine is released. This leads to a difference in the specific gravity of the gas-liquid mixture between the space near the anode 11 and the space near the dividing wall 30, separated by a baffle plate. Using this difference, it is possible to stimulate the internal circulation of the electrolyte solution in the anode chamber 10, thereby making the concentration distribution of the electrolyte solution in the anode chamber 10 more uniform.

Although not shown in FIG. 5, a down conductor may also be additionally provided within the anode chamber 10. The material and configuration of such a current collector can be the same as for the aforementioned collector of the cathode chamber. In the anode chamber 10, the anode 11 itself can also serve as a down conductor.

[0115] (Divider)

The dividing wall 30 is disposed between the anode chamber 10 and the cathode chamber 20. The dividing wall 30 may be referred to as a separator, and the anode chamber 10 and the cathode chamber 20 are separated from each other by a dividing wall 30. As the dividing wall 30, a baffle known as a separator can be used. electrolysis, and an example thereof comprises a baffle formed by welding a nickel-containing plate on the cathode side and a titanium-containing plate on the anode side.

[0116] (Cathode Chamber)

In the cathode compartment 20, when the electrolysis electrode of the present embodiment is inserted on the cathode side, 21 serves as a cathode supply conductor. When the electrolysis electrode of the present embodiment is not inserted on the cathode side, 21 serves as the cathode. When a return current absorber is present, the cathode or cathode supply conductor 21 is electrically connected to the return current absorber. The cathode chamber 20, like the anode chamber 10, preferably has a cathode-side electrolyte solution supply unit and a cathode-side gas-liquid separator. Among the components constituting the cathode compartment 20, components similar to those constituting the anode compartment 10 will not be described.

[0117] (Cathode)

When the electrolysis electrode of the present embodiment is not inserted on the cathode side, the cathode 21 is in the frame of the cathode chamber 20. The cathode 21 preferably has a nickel substrate and a catalyst layer that covers the nickel substrate. Examples of catalyst bed components include elements such as Ru, C, Si, P, S, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Rh, Pd , Ag, Cd, In, Sn, Ta, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho , Er, Tm, Yb and Lu, as well as oxides and hydroxides of these metals. Examples of the method for forming the catalyst layer include electrodeposition, alloy electrodeposition, dispersion / composite electrodeposition, chemical vapor deposition (CVD), physical vapor deposition (PVD), pyrolysis, and sputtering. These methods can be used in combination. The catalyst bed can have multiple layers and multiple elements as needed. The cathode 21 can be subjected to a reduction treatment, if necessary. Nickel, nickel alloys and nickel-plated iron or stainless steel can be used as the substrate for the cathode 21.

As for the shape, any of a perforated metal sheet, a nonwoven fabric, a porous metal, an expanded metal sheet, an electrospinning metal porous foil, a so-called woven metal mesh formed by interlacing of thin metal filaments, and the like can be used.

[0118] (Cathode supply conductor)

When the electrode for electrolysis of the present embodiment is inserted on the cathode side, a cathode supply conductor 21 is provided in the frame of the cathode chamber 20. The cathode supply conductor 21 may be coated with a catalyst component. The catalyst component can be a component that is initially used as a cathode and is stored. Examples of catalyst bed components include elements such as Ru, C, Si, P, S, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Rh, Pd , Ag, Cd, In, Sn, Ta, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho , Er, Tm, Yb and Lu, as well as oxides and hydroxides of these metals. Examples of the method for forming the catalyst layer include electrodeposition, alloy electrodeposition, dispersion / composite electrodeposition, CVD, FOPP, pyrolysis, and sputtering. These methods can be used in combination. The catalyst bed can have multiple layers and multiple elements as needed. Nickel, nickel alloys and nickel-plated iron or stainless steel can be used as the substrate for the cathode supply conductor 21.

Nickel, nickel alloys, and nickel-plated iron or stainless steel without a catalytic coating can be used as the cathode supply conductor 21.

As for the shape, any of a perforated metal sheet, a nonwoven fabric, a porous metal, an expanded metal sheet, an electrospinning metal porous foil, a so-called woven metal mesh formed by interlacing of thin metal filaments, and the like can be used.

[0119] (Reverse Current Absorbing Layer)

As the material for the layer that absorbs the reverse current, a material that is less noble in terms of the redox potential than the redox potential of the element for the aforementioned catalyst layer of the cathode can be selected. Examples include nickel and iron.

[0120] (Down conductor)

The cathode chamber 20 preferably contains a current collector 23. The current collector 23 improves the efficiency of current extraction. In the present embodiment, the collector 23 is a porous plate and is preferably disposed substantially parallel to the surface of the cathode 21.

The collector 23 preferably contains an electrically conductive metal such as nickel, iron, copper, silver and titanium. The current collector 23 can be a mixture, alloy or complex oxide of these metals. The collector 23 may be of any shape as long as the shape allows the collector to function and may be in the form of a plate or mesh.

[0121] (Metallic elastic body)

By placing the metal elastic body 22 between the current collector 23 and the cathode 21, each cathode 21 of a plurality of electrolytic cells 1 connected in series is pressed against the ion exchange membrane 2 to shorten the distance between each anode 11 and each cathode 21. Thus, it is possible to reduce the voltage applied to the entire plurality of electrolytic cells connected in series. cells 1. Reducing voltage helps to reduce power consumption. When the metal resilient body 22 is placed, the pressing pressure created by the metal resilient body 22 allows the electrolysis electrode to stably maintain its position in place when the laminated article containing the electrolysis electrode of the present embodiment is placed in the electrolytic cell.

As the metal resilient body 22, spring elements such as coil and coil springs and damping mats can be used. As the metal elastic body 22, an element can be appropriately applied in consideration of mechanical stress due to pressure on the ion exchange membrane and the like. The metal resilient body 22 may be located on the surface of the collector 23 on the side of the cathode chamber 20, or may be provided on the surface of the partition wall on the side of the anode chamber 10. The two chambers are usually separated so that the cathode chamber 20 becomes smaller than the anode chamber 10. Thus In terms of frame strength and the like, the metal resilient body 22 is preferably placed between the collector 34 and the cathode 21 in the cathode chamber 20. The metal resilient body 22 preferably contains an electrically conductive metal such as nickel, iron, copper, silver and titanium.

[0122] (Holder)

The cathode chamber 20 preferably comprises a holder 24 which electrically connects the collector 23 to the baffle 30. This can achieve an efficient current flow.

The holder 24 preferably contains an electrically conductive metal such as nickel, iron, copper, silver, and titanium. The holder 24 can be of any shape as long as the holder can support the collector 23 and can be in the form of a rod, plate, or mesh. The holder 24 is in the form of a plate, for example. A plurality of holders 24 are disposed between the baffle 30 and the down conductor 23. The plurality of holders 24 are aligned so that their surfaces are parallel to each other. The holders 24 are located substantially perpendicular to the baffle 30 and the down conductor 23.

[0123] (Anode side seal and cathode side seal)

The anode side seal is preferably located on the surface of the frame constituting the anode chamber 10. The cathode side seal is preferably positioned on the surface of the frame constituting the cathode compartment 20. The electrolytic cells are interconnected such that the anode side seal located in one electrolytic cell and the cathode side seal an ion-exchange membrane 2 is laid on an adjacent electrolytic cell (see Figures 5 and 6). These seals can create airtightness at the junctions when a plurality of electrolytic cells 1 are connected in series through an ion exchange membrane 2.

The seals form a seal between the ion exchange membrane and the electrolytic cells. Specific examples of seals include picture frame-like rubber sheets in the center of which an opening is formed. The seals must be resistant to corrosive electrolyte solutions or generated gas and be functional for a long period of time. Thus, with regard to chemical resistance and hardness, vulcanized products and peroxide-crosslinked products of ethylene-propylene-diene rubber (EPDM-rubber) and ethylene-propylene rubber (EPM-rubber) are usually used as seals. Alternatively, if desired, seals can be used in which the area in contact with the liquid (the area in contact with the liquid) is coated with a fluorine-containing resin such as polytetrafluoroethylene (PTFE) and copolymers of tetrafluoroethylene and perfluoroalkylvinyl ethers (PFA). These seals may in each case have an opening that does not impede the flow of the electrolyte solution, and the shape of the opening is not particularly limited. For example, a seal in the form of a picture frame is attached by means of an adhesive or the like along the peripheral edge of each opening of the anode chamber frame constituting the anode compartment 10 or the cathode compartment frame constituting the cathode compartment 20. Then, for example, in the case where two electrolytic cells 1 are connected through ion exchange membrane 2 (see Figure 6), each electrolytic cell 1 to which a seal is attached must be sealed by means of an ion exchange membrane 2. This seal can prevent electrolyte solution, alkali metal hydroxide, chlorine gas, hydrogen gas from escaping from the electrolytic cells 1 and the like formed by electrolysis.

[0124] (Ion exchange membrane 2)

The ion exchange membrane 2 is as described in the above section on the ion exchange membrane.

[0125] (Water electrolysis)

The electrolytic cell of the present embodiment as an electrolysis cell in the case of water electrolysis has a configuration in which an ion exchange membrane in the electrolysis cell for use in the case of the above conventional salt electrolysis is replaced with a microporous membrane. The supplied raw material, which is water, is different from the material for the electrolytic cell in the case of the above-mentioned conventional salt electrolysis. As for other components, parts similar to those of the electrolysis cell in the case of conventional salt electrolysis can also be used in a water electrolysis cell. Since chlorine gas is generated in the anode chamber in conventional salt electrolysis, titanium is used as the anode chamber material, but in the case of water electrolysis, only oxygen gas is emitted in the anode chamber. Thus, a material identical to that of the cathode chamber can be used. Nickel is one example of this. A catalytic coating for generating oxygen is suitable for coating the anode. Examples of the catalytic coating include metals, oxides and hydroxides of platinum group metals and metals from the transition metal group. For example, elements such as platinum, iridium, palladium, ruthenium, nickel, cobalt, and iron can be used.

[0126] <Second embodiment>

Here, a second embodiment of the present invention will be described in detail with reference to Figures 22-42.

[0127] [Laminate Product]

The laminated article according to the second embodiment (hereinafter in the section <Second Embodiment> simply referred to as "the present embodiment") comprises an electrode for electrolysis and a membrane or supply conductor in contact with the electrode for electrolysis, wherein the force applied per unit mass · unit area of the electrode for electrolysis on a membrane or a supply conductor, is less than 1.5 N / (mg · cm ² ). The laminated article of the present embodiment, configured as described above, can improve the operating efficiency during the renewal of the electrode in the electrolytic cell, and in addition, can exhibit excellent electrolysis performance even after the renewal.

That is, according to the layered article of the present embodiment, when the electrode is renewed, the electrode can be renewed as simple as renewing the membrane without complicated work such as disassembling an existing electrode attached to the electrolytic cell, and thereby noticeably improve the working efficiency.

In addition, according to the layered article of the present embodiment, it is possible to maintain or improve the electrolysis performance of the new electrode. Thus, an electrode attached to a standard new electrolytic cell and serving as anode and / or cathode should only serve as a supply conductor. Thus, appreciable reduction or elimination of the catalytic coating can also be possible.

The laminated article of the present embodiment can be stored or transported to consumers in a state where the laminated article is wound around a vinyl chloride pipe or the like (in a wound state or the like), greatly facilitating handling.

As the supply conductor of the present embodiment, various substrates mentioned below, such as a worn electrode (i.e., an existing electrode) and an electrode not having a catalytic coating, can be used.

The laminated product of the present embodiment may have a partially fixed portion provided that the laminated product has the above-described configuration. That is, in the case where the laminated article of the present embodiment has a fixed portion, the non-fixed portion is measured, and the obtained value of the force applied per unit mass · unit area of the electrolysis electrode should be less than 1.5 N / (mg Cm ² ).

[0128] [Electrolysis Electrode]

The electrolysis electrode of the present embodiment has a force applied per unit mass · unit area of less than 1.5 N / (mg · cm ² ), preferably 1.2 N / (mg · cm ² ) or less, more preferably 1, 20 N / (mg · cm ² ) or less from the viewpoint of providing good workability and good adhesion to a membrane such as an ion exchange membrane and a microporous membrane, with a supply conductor (worn electrode and an electrode not having a catalytic coating) and the like. The force is even more preferably 1.1 N / (mg cm ² ) or less, further more preferably 1.10 N / (mg cm ² ) or less, even more preferably 1.0 N / (mg cm ² ) or less, even more preferably 1.00 N / (mg · cm ² ) or less.

From the viewpoint of further improving the electrolysis productivity, the force is preferably more than 0.005 N / (mg cm ² ), more preferably 0.08 N / (mg cm ² ) or more, further preferably 0.1 N / (mg cm ² ) or more, even more preferably 0.14 N / (mg · cm ² ) or more. Even more preferably, the force is 0.2 N / (mg · cm ² ) or more from the viewpoint of further facilitating the handling of a large size (eg, 1.5 mx 2.5 m).

The above-described applied force may be within the above-described range by appropriately adjusting, for example, the below-described open porosity ratio, electrode thickness, arithmetic mean of surface roughness, and the like. For example, more specifically, a higher open porosity ratio results in a lower applied force, and a lower open porosity ratio results in a higher applied force.

The mass per unit area is preferably 48 mg / cm ² or less, more preferably 30 mg / cm ² or less, even more preferably 20 mg / cm ² or less from the standpoint of providing good processability and good adhesion to the membrane, such as an ion exchange membrane and a microporous membrane, with a worn electrode, with a feed conductor not having a catalytic coating, and economy, and moreover, is preferably 15 mg / cm ² or less, for general reasons including manufacturability, adhesion strength and economy. The lower limit is not particularly limited, but is, for example, on the order of 1 mg / cm ² .

The above-described mass per unit area may be within the above-described range, for example, by appropriately adjusting the below-described open porosity ratio, electrode thickness, and the like. More specifically, for example, when the thickness is constant, a higher open porosity ratio results in a decrease in mass per unit area, and a lower open porosity ratio results in a higher mass per unit area.

[0129] The applied force can be measured by methods (i) or (ii) described below, which are as detailed in the Examples. With regard to the applied force, the value obtained by measuring by method (i) (also called "applied force (1)") and the value obtained by measuring by method (ii) (also called "applied force (2)") may be the same or different, and each of the values is less than 1.5 N / (mg · cm ² ).

[0130] [Method (i)]

Nickel plate blasted with alumina 320 grit (thickness 1.2 mm, square with side 200 mm), ion-exchange membrane obtained by applying particles of inorganic material and a binder to both surfaces of a perfluorocarbon polymer into which an ion-exchange group is introduced (square 170 mm side, details of the ion exchange membrane disclosed herein are described in the Examples), and a sample electrolysis electrode (130 mm square) is layered in that order. Thereafter, the laminated product is sufficiently immersed in clean water, and excess water deposited on the surface of the laminated product is removed to obtain a sample for measurement. The arithmetic mean (Ra) of the surface roughness of a nickel plate after blasting is 0.5 to 0.8 μm. A specific method for calculating the arithmetic mean (Ra) of the surface roughness is described in the Examples.

Under the condition of temperature 23 ± 2 ° C and relative humidity 30 ± 5%, only the electrode sample in this measurement sample is lifted in the vertical direction at a speed of 10 mm / minute using a tensile compression machine and the load is measured when the electrode sample is lifted 10 mm vertically. This measurement is repeated three times and the average is calculated.

This average value is divided by the area of the overlapping area of the electrode sample and the ion exchange membrane and by the mass of the ion exchange membrane in the area of overlapping with the electrode sample to calculate the applied force per unit mass · unit area (1) (N / (mg · cm ² )).

[0131] The applied force per unit mass · unit area (1) obtained by method (i) is less than 1.5 N / (mg · cm ² ), preferably 1.2 N / (mg · cm ² ) or less, more preferably 1.20 N / (mg cm ² ) or less, even more preferably 1.1 N / (mg cm ² ) or less, further even more preferably 1.10 N / (mg cm ² ) or less, particularly preferably 1.0 N / (mg cm ² ) or less, particularly preferably 1.00 N / (mg cm ² ) or less from the viewpoint of providing good processability and good adhesion to a membrane such as ion exchange membrane or microporous membrane, a worn electrode, and a supply conductor that does not have a catalytic coating. The force is preferably more than 0.005 N / (mg cm ² ), more preferably 0.08 N / (mg cm ² ) or more, further preferably 0.1 N / (mg cm ² ) or more in view of further improvement electrolysis productivity, and, moreover, more preferably 0.14 N / (mg cm ² ), even more preferably 0.2 N / (mg cm ² ) or more from the standpoint of further facilitating handling of loading and unloading at a large size (for example, size 1.5 mx 2.5 m).

When the electrode for electrolysis of the present embodiment satisfies the applied force (1), the electrode can be combined with a membrane such as an ion exchange membrane or a microporous membrane, or with a supply conductor, and used (i.e., as a laminated article). Thus, when the electrode is renewed, the operation of replacing the cathode and anode fixed to the electrolytic cell in a manner such as welding is eliminated, and the work efficiency is noticeably improved. In addition, by using the electrolysis electrode of the present embodiment as a laminated article combined with an ion exchange membrane, a microporous membrane, or a supply conductor, electrolysis performance can be made comparable to or better than that of the new electrode.

When a new electrolytic cell is shipped, the electrode attached to the electrolytic cell has traditionally been catalytically coated. Since only the combination of the uncatalyzed electrode with the electrolysis electrode of the present embodiment can function the electrode as an electrode, the production step and the volume of the catalyst for the catalytic coating can be significantly reduced or eliminated. A conventional electrode whose catalytic coating has been markedly reduced or removed may be electrically connected to the electrolysis electrode of the present embodiment, and left serving as a supply conductor for passing electric current.

[0132] [Method (ii)]

A nickel plate blasted with alumina 320 grit (thickness 1.2 mm, square with a side of 200 mm, a nickel plate similar to the plate in the above method (i)), and an electrode sample (square with a side of 130 mm) is layered in this okay. Thereafter, the laminated product is sufficiently immersed in clean water, and excess water deposited on the surface of the laminated product is removed to obtain a sample for measurement. Under the condition of temperature 23 ± 2 ° C and relative humidity 30 ± 5%, only the electrode sample in this measurement sample is lifted in the vertical direction at a speed of 10 mm / minute using a tensile compression machine and the load is measured when the electrode sample is lifted 10 mm vertically. This measurement is repeated three times and the average is calculated.

This average value is divided by the area of the overlapping area of the electrode sample and the nickel plate and by the weight of the electrode sample in the overlapping area with the nickel plate to calculate the applied force per unit mass · unit area (2) (N / (mg · cm ² )).

[0133] The applied force per unit mass · unit area (2) obtained by method (ii) is less than 1.5 N / (mg · cm ² ), preferably 1.2 N / (mg · cm ² ) or less, more preferably 1.20 N / (mg cm ² ) or less, even more preferably 1.1 N / (mg cm ² ) or less, further even more preferably 1.10 N / (mg cm ² ) or less, particularly preferably 1.0 N / (mg cm ² ) or less, particularly preferably 1.00 N / (mg cm ² ) or less from the viewpoint of providing good processability and good adhesion to a membrane such as ion exchange membrane or microporous membrane, a worn electrode, and a supply conductor that does not have a catalytic coating. The force is preferably more than 0.005 N / (mg cm ² ), more preferably 0.08 N / (mg cm ² ) or more, further preferably 0.1 N / (mg cm ² ) or more in view of further improvement productivity of electrolysis, and, moreover, is more preferably 0.14 N / (mg · cm ² ), from the point of view of additional facilitation of carrying out loading and unloading at a large size (for example, size 1.5 mx 2.5 m).

The electrolysis electrode of the present embodiment, if satisfies the applied force (2), can be stored or transported to consumers in a state where the electrode is wound around a vinyl chloride pipe or the like (in a wound state or the like), greatly facilitating handling. By connecting the electrolysis electrode of the present embodiment to a worn out existing electrode to form a laminated article, electrolysis performance can be made comparable to or better than that of the new electrode.

[0134] Considering that the electrode for electrolysis of the present embodiment, if it is an electrode having a wide elastic deformation range, can provide better workability and has better adhesion to a membrane such as an ion exchange membrane or a microporous membrane with a worn electrode , with a supply conductor not having a catalytic coating and the like, the thickness of the electrode for electrolysis is preferably 315 μm or less, more preferably 220 μm or less, even more preferably 170 μm or less, even more preferably 150 μm or less, especially preferably 145 µm or less, even more preferably 140 µm or less, further even more preferably 138 µm or less, even more preferably 135 µm or less. A thickness of 135 µm or less can provide good workability. In addition, for reasons similar to the above, the thickness is preferably 130 µm or less, more preferably less than 130 µm, further preferably 115 µm or less, even more preferably 65 µm or less. The lower limit is not particularly limited, but is preferably 1 µm or more, more preferably 5 µm or more for practical reasons, more preferably 20 µm or more. In the present embodiment, “having a wide elastic range” means that when the electrolysis electrode is wound to form a winding, it is unlikely that winding-induced warping will occur after being released from the wound state. The thickness of the electrolysis electrode when the below-mentioned catalyst layer is provided refers to the total thickness of both the electrolysis electrode support and the catalyst layer.

[0135] The electrolysis electrode of the present embodiment preferably comprises an electrolysis electrode support and a catalyst layer. The thickness of the electrode substrate for electrolysis (measured thickness) is, but is not particularly limited, preferably 300 μm or less, more preferably 205 μm or less, even more preferably 155 μm or less, further preferably 135 μm or less, even more preferably 125 μm or less, even more preferably 120 μm or less, even more preferably 100 μm or less from the point of view of ensuring good processability, achieving good adhesion to a membrane such as an ion exchange membrane or a microporous membrane, with a worn electrode (supply conductor) and an electrode ( feed conductor), which does not have a catalytic coating, being suitable for roll-up and satisfactory folding into folds and facilitates loading and unloading at a large size (for example, size 1.5 mx 2.5 m), and, in addition, still more preferably 50 µm or less in terms of processability and economy. The lower limit is not particularly limited, but is, for example, 1 µm, preferably 5 µm, more preferably 15 µm.

[0136] In the present embodiment, between a membrane such as an ion exchange membrane or a microporous membrane and an electrode or metal porous plate or metal plate (i.e., a supply conductor), such as a worn out existing electrode and an electrode not having a catalytic coating, and an electrode for electrolysis , preferably liquid is placed. Any liquid such as water or organic solvents can be used as the liquid, provided that the liquid creates surface tension. The higher the surface tension of the liquid, the greater the force applied between the membrane and the electrolysis electrode, or between the porous metal plate or the metal plate and the electrolysis electrode. Thus, a liquid having a higher surface tension is preferred. Examples of liquid include the following (the numerical value in parentheses represents the surface tension of the liquid at 20 ° C):

hexane (20.44 mN / m), acetone (23.30 mN / m), methanol (24.00 mN / m), ethanol (24.05 mN / m), ethylene glycol (50.21 mN / m) and water (72.76 mN / m).

The liquid having a high surface tension allows the membrane and the electrolysis electrode or the porous metal plate or metal plate (feed conductor) and the electrolysis electrode to combine (to form a laminated article), thereby facilitating the renewal of the electrode. The liquid between the membrane and the electrolysis electrode, or between the porous metal plate or the metal plate (supply conductor) and the electrolysis electrode, may be present in such an amount that both of them adhere to each other under the action of surface tension. As a result, after placing the layered article in the electrolytic cell, the liquid, if mixed with the electrolyte solution, does not affect the electrolysis itself due to the small amount of liquid.

From a practical point of view, a liquid having a surface tension of 24 mN / m to 80 mN / m such as ethanol, ethylene glycol and water is preferably used as the liquid. Particularly preferred is water or an aqueous alkali solution obtained by dissolving caustic soda, potassium hydroxide, lithium hydroxide, sodium hydrogencarbonate, potassium hydrogencarbonate, sodium carbonate, potassium carbonate or the like in water. Alternatively, the surface tension can be adjusted by bringing these fluids into contact with a surfactant. When a surfactant is contained, the bond strength between the membrane and the electrolysis electrode or between the porous metal plate or the metal plate (supply conductor) and the electrolysis electrode is changed, allowing processability to be adjusted. The surfactant is not particularly limited, and both ionic surfactants and nonionic surfactants can be used.

[0137] The proportion measured by the following method (2) on the electrode for electrolysis of the present embodiment is not particularly limited, but is preferably 90% or more, more preferably 92% or more from the viewpoint of ensuring good processability and achieving good adhesion strength with membrane, such as an ion exchange membrane or a microporous membrane, with a worn electrode (supply conductor) and an electrode (supply conductor) not having a catalytic coating, and additionally preferably 95% or more from the point of view of further facilitating handling when large size (for example , size 1.5 m × 2.5 m). The upper limit value is 100%.

[Method (2)]

An ion exchange membrane (170 mm square) and an electrode sample (130 mm square) are layered in this order. The laminated product is placed on the curved surface of a polyethylene pipe (outer diameter: 280 mm) so that the electrode sample in this laminated product is positioned outside at a temperature of 23 ± 2 ° C and a relative humidity of 30 ± 5%, the laminated product and the pipe are sufficiently immersed into clean water, remove the excess water deposited on the surface of the laminated product and the pipe, and then, one minute after this removal, measure the fraction (%) of the area of the area in which the ion-exchange membrane (square with a side of 170 mm) is in close contact with electrode.

[0138] The proportion measured by the following method (3) on the electrode for electrolysis of the present embodiment is not particularly limited, but is preferably 75% or more, more preferably 80% or more from the viewpoint of ensuring good workability, achieving good adhesion strength with membrane, such as an ion exchange membrane or microporous membrane, with a worn electrode (supply conductor) and an electrode (supply conductor) not having a catalytic coating, and for proper roll-winding and satisfactory creasing, and is additionally preferably 90% or more from the point of view of additional facilitation of loading and unloading at a large size (for example, size 1.5 m × 2.5 m). The upper limit value is 100%.

[Method (3)]

An ion exchange membrane (170 mm square) and an electrode sample (130 mm square) are layered in this order. The laminated product is placed on the curved surface of a polyethylene pipe (outer diameter: 145 mm) so that the electrode sample in this laminated product is positioned externally at a temperature of 23 ± 2 ° C and a relative humidity of 30 ± 5%, the laminated product and the pipe are sufficiently immersed into clean water, remove the excess water deposited on the surface of the laminated product and the pipe, and then, one minute after this removal, measure the fraction (%) of the area of the area in which the ion-exchange membrane (square with a side of 170 mm) is in close contact with electrode.

[0139] The electrode for electrolysis of the present embodiment has a porous structure and an open porosity ratio or void ratio of 5 to 90% or less in terms of providing good processability, achieving good adhesion to a membrane such as an ion exchange membrane or a microporous membrane, with a worn electrode (supply conductor) and an electrode (supply conductor) not having a catalytic coating, and preventing the accumulation of gas evolved during electrolysis, although not specifically limited thereto. The open porosity ratio is more preferably 10 to 80% or less, more preferably 20 to 75%.

The Open Porosity Ratio represents the fraction of lumen areas per unit volume. The calculation method may differ depending on whether sub-micron-sized gaps are considered or only visible gaps are considered. In the present embodiment, the volume V was calculated from the values of the measured thickness, the width and the length of the electrode, and in addition, the weight W was measured to thereby calculate the open porosity coefficient A by the following formula.

A = (1– (W / (V × ρ)) × 100

ρ is the density of the electrode material (g / cm ³ ). For example, the ρ of nickel is 8.908 g / cm ³ and the ρ of titanium is 4.506 g / cm ³ . The open porosity ratio is appropriately controlled by changing the area of perforated metal per unit area in the case of a perforated metal sheet, changing the values of SW (short diameter), LW (long diameter), and feed in the case of expanded metal sheet, changing the linear dimensions of the diameter of the metal fiber, and sieve numbers in the case of a mesh, a change in the photoresist pattern used in the case of electrospinning, a change in the diameter of the metal fiber and the density of the fiber in the case of a nonwoven fabric, a change in the mold for forming cavities in the case of a porous metal, or the like.

[0140] The value obtained by measuring by the following method (A) of the electrode for electrolysis of the present embodiment is preferably 40 mm or less, more preferably 29 mm or less, further preferably 10 mm or less, even more preferably 6.5 mm or less from the standpoint of manufacturability. The specific measurement method is as described in the Examples.

[Method (A)]

At a temperature of 23 ± 2 ° C and a relative humidity of 30 ± 5%, a sample obtained by layering an ion exchange membrane and an electrolysis electrode is wound around and fixed to the curved surface of a sleeve made of polyvinyl chloride having an outer diameter of φ 32 mm, and within 6 hours; thereafter, when the electrolysis electrode is separated from the sample and placed on the flat plate, the heights L ₁ and L ₂ in the vertical direction at both edges of the electrolysis electrode are measured, and their average value is used as the measurement value.

[0141] In the electrolysis electrode in the present embodiment, the ventilation resistance measured at a temperature of 24 ° C, a relative humidity of 32%, a piston speed of 0.2 cm / s and a ventilation volume of 0.4 cm ³ / cm ² / s (here hereinafter also referred to as “measurement condition 1”) is preferably 24 kPa · s / m or less when the electrolysis electrode has a size of 50 mm × 50 mm (hereinafter also referred to as “ventilation resistance 1”). A high ventilation resistance means that the air flows with more difficulty and belongs to a high density state. In this state, the electrolysis product remains in the electrode, and the reagents are more difficult to diffuse into the inside of the electrode, and thus the electrolysis operating parameters (such as voltage) tend to deteriorate. The concentration on the membrane surface tends to increase. More specifically, the concentration of caustic soda increases at the surface of the cathode, and the supply of brine to the surface of the anode tends to decrease. As a result, the product accumulates to a high concentration at the interface where the membrane contacts the electrode. This build-up leads to damage to the membrane at the cathode surface and damage to the membrane at the anode surface. In the present embodiment, in order to prevent these defects, the ventilation resistance is preferably controlled to 24 kPa · s / m or less. For similar reasons, as above, the ventilation resistance is more preferably less than 0.19 kPa · s / m, further preferably 0.15 kPa · s / m or less, even more preferably 0.07 kPa · s / m or less.

In the present embodiment, when the ventilation resistance is higher than a certain value, NaOH evolved at the electrode tends to accumulate at the interface between the electrode and the membrane, resulting in a high concentration in the case of the cathode, and the brine supply tends to be reduced, causing the brine concentration to decrease. case of the anode. To prevent damage to the membrane that can be caused by such accumulation, the ventilation resistance is preferably less than 0.19 kPa s / m, more preferably 0.15 kPa s / m or less, even more preferably 0.07 kPa s / m or less.

In contrast, when the ventilation resistance is low, the area of the electrode is reduced and the area over which electrolysis occurs is reduced. Thus, electrolysis operating parameters (such as voltage) may deteriorate. When the ventilation resistance becomes zero, the supply conductor acts as an electrode since no electrode for electrolysis is provided, and the electrolysis operating parameters (such as voltage) tend to deteriorate markedly. From this point of view, the preferable lower limit value identified as ventilation resistance 1 is not particularly limited, but is preferably more than 0 kPa s / m, more preferably 0.0001 kPa s / m or more, even more preferably 0.001 kPa s / m or more.

When the ventilation resistance 1 is 0.07 kPa · s / m or less, sufficient measurement accuracy may not be achieved by the measurement method used. From this point of view, it is also possible to evaluate an electrolysis electrode having a ventilation resistance 1 of 0.07 kPa · s / m or less using a ventilation resistance (hereinafter also referred to as "ventilation resistance 2") obtained by the following measurement method ( hereinafter also referred to as "measurement condition 2"). That is, the ventilation resistance 2 is the ventilation resistance measured when the electrolysis electrode has a size of 50 mm × 50 mm, under conditions of a temperature of 24 ° C, a relative humidity of 32%, a piston speed of 0.2 cm / s and a ventilation volume of 0.4. cm ³ / cm ² / s.

Specific methods for measuring ventilation resistances 1 and 2 are described in Examples.

Ventilation resistances 1 and 2 can be within the above-described range by appropriately adjusting, for example, open porosity ratio, electrode thickness, and the like. More specifically, for example, when the thickness is constant, a higher open porosity ratio tends to lead to lower ventilation resistance values 1 and 2, and a lower open porosity ratio leads to higher ventilation resistance values 1 and 2.

[0142] In the electrolysis electrode of the present embodiment, as mentioned above, the force applied per unit mass · unit area of the electrolysis electrode on the membrane or supply conductor is less than 1.5 N / (mg · cm ² ). Thereby, the electrolysis electrode of the present embodiment is pressed with moderate adhesion to the membrane or supply conductor (eg, an existing anode or cathode in an electrolytic cell), thereby allowing the membrane and supply conductor laminate to be formed. That is, there is no need to create a strong attachment of the membrane or the supply conductor with the electrode for electrolysis by a complex method, such as thermocompression. The laminate is formed only under a relatively weak force, for example, by surface tension due to moisture contained in a membrane such as an ion exchange membrane and a microporous membrane, and thus any scale laminate can be easily assembled. In addition, such a laminated article exhibits excellent electrolysis characteristics. Thus, the laminated article of the present embodiment is suitable for use in electrolysis and can be particularly advantageously used in applications such as cell cells and cell refurbishment.

[0143] Hereinafter, one aspect of the electrolysis electrode of the present embodiment will be described.

The electrolysis electrode of the present embodiment preferably comprises an electrolysis electrode support and a catalyst layer. The catalyst bed can be composed of multiple layers, as shown below, or can have a single layer configuration.

As shown in FIG. 22, the electrolysis electrode 100 of the present embodiment includes an electrolysis electrode substrate 10 and a pair of first layers 20 that cover both surfaces of the electrolysis electrode substrate 10. The first layers 20 preferably cover the entire electrode substrate 10 for electrolysis. Apparently, this coating increases the catalytic activity and durability (resistance) of the electrode. One first layer 20 can only be laminated to one surface of the electrolysis electrode substrate 10.

Figure 22 also shows that the surfaces of the first layers 20 can be covered with the second layers 30. The first layers 20 are preferably covered with the second layers 30 in their entirety. Alternatively, one second layer 30 may be laminated to only one surface of the first layer 20.

[0144] (Electrode support for electrolysis)

As the electrode substrate 10 for electrolysis, for example, nickel, nickel alloys, stainless steel, and, in addition, valve metals, including titanium, can be used, although not limited thereto. Substrate 10 preferably contains at least one element selected from nickel (Ni) and titanium (Ti).

When stainless steel is used in an aqueous alkali solution of high concentration, iron and chromium are washed out and the electrical conductivity is in the order of one tenth that of nickel. In view of the above, as the electrode substrate for electrolysis, a substrate containing nickel (Ni) is preferable.

Alternatively, when the electrode substrate 10 for electrolysis is used in a brine with a high concentration close to saturation, in an atmosphere in which chlorine gas is generated, the material of the electrode substrate 10 is also preferably titanium having high corrosion resistance.

The shape of the electrode substrate 10 for electrolysis is not particularly limited, and a shape suitable for this purpose can be selected. As the mold, any of a perforated metal sheet, a nonwoven fabric, a porous metal, an expanded metal sheet, an electrospinning metal porous foil, a so-called woven metal mesh, and the like can be used. Of these, perforated metal sheet or expanded metal sheet is preferable. Electrospinning is a method of producing a thin metal foil having a precisely shaped pattern using photolithography and electrodeposition in combination. It is a method involving patterning a substrate with a photoresist and electrodeposition of a portion not protected by the resist to form a metal thin film.

With regard to the shape of the electrode support for electrolysis, a suitable specification depends on the distance between the anode and the cathode in the electrolysis cell. In the case where the distance between the anode and the cathode is finite, the shape of an expanded metal sheet or a perforated metal sheet can be used, and in the case of a so-called zero-gap electrolyzer in which the ion exchange membrane is in contact with the electrode, a formed interlacing of fine metal filaments woven metal mesh, wire mesh, porous metal, metal nonwoven fabric, expanded metal sheet, perforated metal sheet, metal porous foil, and the like, although not limited thereto.

Examples of the electrode substrate 10 for electrolysis include metal porous foil, wire mesh, metal nonwoven fabric, perforated metal sheet, expanded metal sheet, and porous metal.

As the plate material before being processed to form a perforated metal sheet or expanded metal sheet, rolled plate materials and electrolytic foils are preferred. The electrolytic foil is preferably subjected to a further electrodeposition treatment using the same element as its base material as a further treatment to thereby form roughness on one or both of its surfaces.

The thickness of the electrolysis electrode substrate 10 as mentioned above is preferably 300 µm or less, more preferably 205 µm or less, further preferably 155 µm or less, even more preferably 135 µm or less, even more preferably 125 µm or less, even more preferably 120 µm or less, even more preferably 100 µm or less, and further even more preferably 50 µm or less in terms of processability and economy. The lower limit is not particularly limited, but is, for example, 1 µm, preferably 5 µm, more preferably 15 µm.

[0145] In the electrolysis electrode substrate, residual stress during processing is preferably relieved by annealing the electrolysis electrode substrate in an oxidizing atmosphere. It is preferable to form roughness using a steel grid, an alumina grid or the like on the surface of the electrode substrate for electrolysis, followed by acid treatment to increase its surface area in order to improve adhesion to the catalyst layer that is coated on the surface. Alternatively, it is preferable to carry out the electrodeposition treatment using the same element as the substrate to increase the surface area.

[0146] To bring the first layer 20 into intimate contact with the surface of the electrolysis electrode substrate 10, the electrolysis electrode substrate 10 is preferably subjected to a surface area increase treatment. Examples of surface area enhancing treatments include chopped wire blasting, steel grating, alumina grating or the like, acidizing using sulfuric acid or hydrochloric acid, and electrodeposition using the same element as in the substrate. The arithmetic mean (Ra) of the surface roughness on the surface of the substrate is not particularly limited, but is preferably 0.05 µm to 50 µm, more preferably 0.1 to 10 µm, even more preferably 0.1 to 8 µm.

[0147] Next, a case will be described where the electrolysis electrode of the present embodiment is used as an anode for conventional salt electrolysis.

(First layer)

In Figure 22, the first layer 20 contains at least one of ruthenium oxides, iridium oxides and titanium oxides as a catalyst layer. Examples of ruthenium oxide include RuO ₂ . Examples of iridium oxide include IrO ₂ . Examples of titanium oxide include TiO ₂ . The first layer 20 preferably contains two oxides: ruthenium oxide and titanium oxide, or three oxides: ruthenium oxide, iridium oxide and titanium oxide. This makes the first layer 20 more stable and further improves the adhesion to the second layer 30.

[0148] When the first layer 20 contains two oxides: ruthenium oxide and titanium oxide, the first layer 20 preferably contains from 1 to 9 moles, more preferably from 1 to 4 moles of titanium oxide, based on 1 mole of ruthenium oxide contained in the first layer 20 With the compositional ratio of the two oxides in this range, the electrolysis electrode 100 exhibits excellent resistance.

[0149] When the first layer 20 contains three oxides: ruthenium oxide, iridium oxide and titanium oxide, the first layer 20 preferably contains 0.2 to 3 moles, more preferably 0.3 to 2.5 moles of iridium oxide per 1 mol of ruthenium oxide contained in the first layer 20. The first layer 20 preferably contains from 0.3 to 8 moles, more preferably from 1 to 7 moles of titanium oxide, based on 1 mole of ruthenium oxide contained in the first layer 20. With a compositional ratio of three oxides in this range, the electrolysis electrode 100 exhibits excellent resistance.

[0150] When the first layer 20 contains at least two of ruthenium oxide, iridium oxide and titanium oxide, these oxides preferably form a solid solution. The formation of a solid solution of the oxides allows the electrolysis electrode 100 to exhibit excellent resistance.

[0151] In addition to the above-described compositions, oxides of various compositions can be used, provided that at least one of ruthenium oxide, iridium oxide, and titanium oxide is contained. For example, an oxide coating called DSA (R), which contains ruthenium, iridium, tantalum, niobium, titanium, tin, cobalt, manganese, platinum, and the like, can be used as the first layer 20.

[0152] The first layer 20 need not be a single layer and may include multiple layers. For example, the first layer 20 may include a three-oxide layer and a two-oxide layer. The thickness of the first layer 20 is preferably 0.05 to 10 µm, more preferably 0.1 to 8 µm.

[0153] (Second layer)

The second layer 30 preferably contains ruthenium and titanium. This makes it possible to further reduce the electrical overvoltage of chlorine immediately after electrolysis.

[0154] The second layer 30 preferably contains palladium oxide, a solid solution of palladium and platinum oxide, or an alloy of palladium and platinum. This makes it possible to further reduce the electrical overvoltage of chlorine immediately after electrolysis.

[0155] The thicker second layer 30 can maintain the electrolysis performance for a long period of time, but from the standpoint of economy, the thickness is preferably 0.05 to 3 µm.

[0156] Next, a situation will be described where the electrolysis electrode of the present embodiment is used as a cathode for conventional salt electrolysis.

(First layer)

Examples of the components of the first layer 20 as a catalyst layer include elements such as C, Si, P, S, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, In, Sn, Ta, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu, as well as metal oxides and hydroxides.

The first layer 20 may or may not contain at least one of platinum group metals, platinum group metal oxides, platinum group metal hydroxides, and platinum group metal containing alloys.

When the first layer 20 contains at least one of platinum group metals, platinum group metal oxides, platinum group metal hydroxides and alloys containing a platinum group metal, platinum group metals, platinum group metal oxides, platinum group metal hydroxides, and platinum metal containing alloys the groups preferably contain at least one platinum group metal from platinum, palladium, rhodium, ruthenium and iridium.

The platinum group metal is preferably platinum.

As the oxide of the platinum group metal, ruthenium oxide is preferably contained.

As the hydroxide of the platinum group metal, ruthenium hydroxide is preferably contained.

As an alloy of platinum group metals, an alloy of platinum with nickel, iron and cobalt is preferably included.

In addition, if necessary, an oxide or hydroxide of a lanthanide element is preferably contained as the second component. This allows the electrolysis electrode 100 to exhibit excellent resistance.

As the oxide or hydroxide of the lanthanide element, preferably at least one selected from lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium and dysprosium is contained.

In addition, if necessary, a transition metal oxide or hydroxide is preferably contained as the third component.

The addition of the third component allows the electrolysis electrode 100 to exhibit superior resistance and lower electrolysis voltage.

Examples of a preferred combination include only ruthenium, ruthenium + nickel, ruthenium + cerium, ruthenium + lanthanum, ruthenium + lanthanum + platinum, ruthenium + lanthanum + palladium, ruthenium + praseodymium, ruthenium + praseodymium + platinum, ruthenium + praseodymium + platinum + palladium, ruthenium + neodymium, ruthenium + neodymium + platinum, ruthenium + neodymium + manganese, ruthenium + neodymium + iron, ruthenium + neodymium + cobalt, ruthenium + neodymium + zinc, ruthenium + neodymium + gallium, ruthenium + neodymium + sulfur, ruthenium + neodymium + lead , ruthenium + neodymium + nickel, ruthenium + neodymium + copper, ruthenium + samarium, ruthenium + samarium + manganese, ruthenium + samarium + iron, ruthenium + samarium + cobalt, ruthenium + samarium + zinc, ruthenium + samarium + gallium, ruthenium + samarium + sulfur, ruthenium + samarium + lead, ruthenium + samarium + nickel, platinum + cerium, platinum + palladium + cerium, platinum + palladium + lanthanum + cerium, platinum + iridium, platinum + palladium, platinum + iridium + palladium, platinum + nickel + palladium, platinum + nickel + ruthenium, platinum and nickel alloys, platinum and cobalt alloys and platinum and iron alloys.

When platinum-group metals, platinum-group metal oxides, platinum-group metal hydroxides, and platinum-group metal-containing alloys are not contained, the main component of the catalyst is preferably the element nickel.

Preferably, at least one of nickel metal, nickel oxides and hydroxides is contained.

A transition metal can be added as a second component. As the second added component, at least one of titanium, tin, molybdenum, cobalt, manganese, iron, sulfur, zinc, copper and carbon is preferably contained.

Examples of a preferred combination include nickel + tin, nickel + titanium, nickel + molybdenum, and nickel + cobalt.

If necessary, an intermediate layer may be disposed between the first layer 20 and the electrolysis electrode substrate 10. By placing the intermediate layer, the resistance of the electrolysis electrode 100 can be improved.

Preferred as the intermediate layer are those which have an affinity for both the first layer 20 and the electrode substrate 10 for electrolysis. As the intermediate layer, preferred are nickel oxides, platinum group metals, platinum group metal oxides and platinum group metal hydroxides. The intermediate layer can be formed by applying and firing a solution containing the component that forms the intermediate layer. Alternatively, a surface oxide layer can also be formed by subjecting the substrate to heat treatment at a temperature of 300 to 600 ° C. in an air atmosphere. In addition, this layer can be formed by a known method such as a thermal spraying method and an ionic deposition method.

[0157] (Second layer)

Examples of the components of the first layer 30 as a catalyst layer include elements such as C, Si, P, S, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, In, Sn, Ta, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu, as well as metal oxides and hydroxides.

The first layer 30 may or may not contain at least one of platinum group metals, platinum group metal oxides, platinum group metal hydroxides, and platinum group metal containing alloys. Examples of a preferred combination of elements contained in the second layer include those listed for the first layer. The combination of the first layer and the second layer can be a combination in which the compositions are the same and the compositional ratios are different, or it can be a combination of different compositions.

[0158] With regard to the thickness of the catalyst layer, the total thickness of the formed catalyst layer and the intermediate layer is preferably 0.01 µm to 20 µm. With a thickness of 0.01 µm or more, the catalyst layer can sufficiently serve as a catalyst. With a thickness of 20 µm or less, a strong catalyst layer can be formed that is unlikely to separate from the support. The thickness is more preferably 0.05 µm to 15 µm. The thickness is more preferably 0.1 to 10 µm. Even more preferably, the thickness is 0.2 to 8 µm.

[0159] The thickness of the electrode, that is, the combined thickness of the electrolysis electrode support and the catalyst layer, is preferably 315 µm or less, more preferably 220 µm or less, further preferably 170 µm or less, even more preferably 150 µm or less, particularly preferably 145 µm or less, even more preferably 140 µm or less, even more preferably 138 µm or less, further even more preferably 135 µm or less, with respect to the workability of the electrode. A thickness of 135 µm or less can provide good workability. In addition, for similar reasons as above, the thickness is preferably 130 µm or less, more preferably less than 130 µm, even more preferably 115 µm or less, further more preferably 65 µm or less. The lower limit is not particularly limited, but is preferably 1 µm or more, more preferably 5 µm or more for practical reasons, more preferably 20 µm or more. The thickness of the electrode can be determined by measuring with a digital thickness gauge (from Mitutoyo Corporation, minimum scale 0.001 mm). The thickness of the substrate of the electrolysis electrode can be measured in the same manner as in the case of the electrolysis electrode. The thickness of the catalyst layer can be determined by subtracting the thickness of the electrolysis electrode support from the thickness of the electrolysis electrode.

[0160] (Method for Manufacturing Electrolysis Electrode)

Next, one embodiment of a method for manufacturing an electrode 100 for electrolysis will be described in detail.

In the present embodiment, the electrolysis electrode 100 can be obtained by forming a first layer 20, preferably a second layer 30 on the electrolysis electrode substrate by a method such as firing a coating film in an oxygen atmosphere (pyrolysis) or ion deposition, electrodeposition, or thermal sputtering. The production method of the present embodiment as mentioned above can achieve high formation productivity of the electrolysis electrode 100. More specifically, a catalyst layer is formed on the electrode support for electrolysis by an application step in which a coating liquid containing the catalyst is applied, a drying step in which the coating liquid is dried, and a pyrolysis step in which pyrolysis is performed. Pyrolysis here means that a metal salt, which is to be a precursor, decomposes by heating into a metal or metal oxide and a gaseous substance. The decomposition product depends on the nature of the metal used, the type of salt and the atmosphere in which the pyrolysis is carried out, and many metals tend to form oxides in an oxidizing atmosphere. In the industrial process for making an electrode, pyrolysis is usually performed in air and in many cases a metal oxide or metal hydroxide is formed.

[0161] (Formation of the first layer of the anode)

(Application stage)

The first layer 20 is obtained by applying a solution in which at least one metal salt of ruthenium, iridium and titanium (first coating liquid) is dissolved on the electrode substrate for electrolysis, and then pyrolysis (calcining) the coating liquid in the presence of oxygen. The content of ruthenium, iridium and titanium in the first cover liquid is substantially equivalent to that in the first layer 20.

[0162] The metal salts can be chlorides, nitrates, sulfates, metal alkoxides, and any other form. The solvent of the first coating liquid can be selected depending on the type of metal salt, and water and alcohols such as butanol can be used. As the solvent, water or a mixed solvent of water and alcohol is preferred. The total metal concentration in the first coating liquid in which the metal salts are dissolved is not particularly limited, but is preferably in the range of 10 to 150 g / L in consideration of the thickness of the coating film formed by a single application.

[0163] Examples of the method used as the method for applying the first coating liquid to the electrolysis electrode substrate 10 include a method of dipping the electrolysis electrode substrate 10 into the first coating liquid, a method for applying the first coating liquid with a brush, a rolling method using a sponge roller impregnated the first coating liquid, and an electrostatic coating method in which the electrode substrate 10 for electrolysis and the first coating liquid are charged with opposite charges and sputtering is performed. Among them, a rolling method or an electrostatic coating method is preferable, which has excellent production performance on an industrial scale.

[0164]

(Drying step and pyrolysis step)

After applying the first coating liquid to the electrode substrate 100 for electrolysis, it is dried at a temperature of 10 to 90 ° C and subjected to pyrolysis in a roasting furnace heated to a temperature of 350 to 650 ° C. Between drying and pyrolysis, if necessary, a pre-firing can be performed at a temperature of 100 to 350 ° C. The temperature for drying, pre-firing and pyrolysis is appropriately selected depending on the composition and type of solvent of the first coating liquid. A longer period of pyrolysis time in each step is preferable, but from the viewpoint of productivity of producing an electrode, 3 to 60 minutes, more preferably 5 to 20 minutes are preferable.

[0165] The cycle of the above-described application, drying and pyrolysis is repeated to form a coating (first layer 20) to a predetermined thickness. After the first layer 20 is formed and then further post-baked for an extended period of time as required, this can further increase the stability of the first layer 20.

[0166] (Formation of the second layer of the anode)

The second layer 30, which is formed if necessary, is obtained, for example, by applying a solution containing a palladium compound and a platinum compound or a solution containing a ruthenium compound and a titanium compound (second coating liquid) on the first layer 20, and then the coating liquid is subjected to pyrolysis in presence of oxygen.

[0167] (Formation of the first cathode layer by pyrolysis method)

(Application stage)

The first layer 20 is obtained by applying a solution in which metal salts in various combinations are dissolved (first coating liquid) on an electrode substrate for electrolysis, and then pyrolysis (calcining) the coating liquid in the presence of oxygen. The metal content in the first coating liquid is substantially equivalent to that in the first layer 20.

[0168] The metal salts can be chlorides, nitrates, sulfates, metal alkoxides, and any other form. The solvent of the first coating liquid can be selected depending on the type of metal salt, and water and alcohols such as butanol can be used. As the solvent, water or a mixed solvent of water and alcohol is preferred. The total metal concentration in the first coating liquid in which the metal salts are dissolved is not particularly limited, but is preferably in the range of 10 to 150 g / L in consideration of the thickness of the coating film formed by a single application.

[0169] Examples of the method used as the method for applying the first coating liquid to the electrolysis electrode substrate 10 include a method for dipping the electrolysis electrode substrate 10 into the first coating liquid, a method for applying the first coating liquid with a brush, a rolling method using a sponge roller impregnated the first coating liquid, and an electrostatic coating method in which the electrode substrate 10 for electrolysis and the first coating liquid are charged with opposite charges and sputtering is performed. Among them, a rolling method or an electrostatic coating method is preferable, which has excellent production performance on an industrial scale.

[0170] (Drying Step and Pyrolysis Step)

After applying the first coating liquid to the electrode substrate 100 for electrolysis, it is dried at a temperature of 10 to 90 ° C and subjected to pyrolysis in a roasting furnace heated to a temperature of 350 to 650 ° C. Between drying and pyrolysis, if necessary, a pre-firing can be performed at a temperature of 100 to 350 ° C. The temperature for drying, pre-firing and pyrolysis is appropriately selected depending on the composition and type of solvent of the first coating liquid. A longer period of pyrolysis time in each step is preferable, but from the viewpoint of productivity of producing an electrode, 3 to 60 minutes, more preferably 5 to 20 minutes are preferable.

[0171] The cycle of the above-described application, drying and pyrolysis is repeated to form a coating (first layer 20) to a predetermined thickness. After the first layer 20 is formed and then further post-baked for an extended period of time as required, this can further increase the stability of the first layer 20.

[0172] (Interlayer Formation)

The intermediate layer, which is formed, if necessary, is obtained, for example, by applying a solution containing a palladium compound or a platinum compound (second coating liquid) to a substrate, and then pyrolysis of the coating liquid in the presence of oxygen. Alternatively, the nickel oxide intermediate layer can be formed on the surface of the substrate by heating the substrate only, without applying a solution thereto.

[0173] (Formation of the first cathode layer by ion deposition)

The first layer 20 can also be formed by ion deposition.

The example comprises a method in which a substrate is fixed in a chamber and a ruthenium metal target is irradiated with an electron beam. Particles of vaporized metallic ruthenium are positively charged in the plasma in the chamber, deposited on a negatively charged substrate. The plasma atmosphere is argon and / or oxygen and ruthenium is deposited on the substrate as ruthenium oxide.

[0174] (Formation of the first cathode layer by electrodeposition)

The first layer 20 can also be formed by electrodeposition.

As an example, when the substrate is used as a cathode and is subjected to plating in an electrolyte solution containing nickel and tin, an electrolytic plating of a nickel-tin alloy can be formed.

[0175] (Formation of the first layer of the cathode by thermal spraying)

The first layer 20 can also be formed by thermal spraying.

By way of example, nickel oxide particles sprayed by plasma onto a substrate may form a catalyst bed in which nickel metal and nickel oxide are mixed.

[0176] The electrolysis electrode of the present embodiment may be combined with a membrane such as an ion exchange membrane or a microporous membrane and used. Thus, the electrode can be used as an electrode combined with a membrane. Then the work of replacing the cathode and anode is eliminated when renewing the electrode and the work efficiency is noticeably improved.

An electrode combined with a membrane, such as an ion exchange membrane and a microporous membrane, can make electrolysis performance comparable to or better than that with a new electrode.

[0177] Next, the ion exchange membrane will be described in detail.

[Ion exchange membrane]

The ion exchange membrane has a membrane body containing a hydrocarbon polymer or a fluorine-containing polymer having an ion exchange group, and a coating layer provided on at least one surface of the membrane body. The coating layer contains particles of inorganic material and a binder, and the specific surface area of the coating layer is 0.1 to 10 m ² / g. In an ion exchange membrane having such a structure, the effect of gas evolved during electrolysis on the electrolysis performance is small, and stable electrolysis performance can be demonstrated.

The above-described fluoropolymer ion exchange membrane into which an ion exchange group has been introduced contains one of either a sulfonic acid layer having an ion exchange group derived from a sulfo group (a group represented by —SO ₃ ^- , hereinafter also referred to as a “sulfonic acid group”), or a carboxylic acid layer having an ion exchange group derived from a carboxyl group (a group represented as —CO ₂ ^- , hereinafter also referred to as a “carboxylic acid group”). From the point of view of strength and dimensional stability, it is preferable to additionally include core reinforcing materials.

The inorganic material particles and the binder will be described in detail below in the coating layer description section.

[0178] Figure 23 illustrates a schematic sectional view showing one embodiment of an ion exchange membrane. The ion exchange membrane 1 has a membrane body 10 containing a hydrocarbon polymer or a fluorine-containing polymer having an ion exchange group, and coating layers 11a and 11b formed on both surfaces of the membrane body 10.

[0179] In the ion exchange membrane 1, the membrane body 10 includes a sulfonic acid layer 3 having an ion exchange group derived from a sulfo group (a group represented by —SO ₃ ^- , hereinafter also referred to as a “sulfonic acid group”), and a carboxylic acid layer 2, having an ion exchange group derived from a carboxyl group (a group represented by —CO ₂ ^- , hereinafter also referred to as a “carboxylic acid group”), and core reinforcing materials 4 that increase strength and dimensional stability. An ion exchange membrane 1 including a sulfonic acid layer 3 and a carboxylic acid layer 2 is suitably used as an anion exchange membrane.

[0180] The ion exchange membrane may include one of a sulfonic acid layer and a carboxylic acid layer. The ion exchange membrane does not need to be reinforced with core reinforcing materials, and the arrangement of the core reinforcing materials is not limited to the example in FIG. 23.

[0181] (Membrane Body)

First, the membrane body 10 constituting the ion exchange membrane 1 will be described.

The body 10 of the membrane should be such that its function is to provide selective permeation of cations, and contains a hydrocarbon polymer or a fluorine-containing polymer having an ion exchange group. Its configuration and material are not particularly limited, and preferable ones can be appropriately selected.

[0182] The hydrocarbon polymer or fluorine-containing polymer having an ion exchange group in the membrane body 10 can be obtained from a hydrocarbon polymer or fluorine-containing polymer having an ion exchange group precursor capable of forming an ion exchange group by hydrolysis or the like. More specifically, for example, after a polymer containing a fluorinated hydrocarbon backbone having a side chain that is converted to an ion exchange group by hydrolysis or the like (ion exchange group precursor) is used to obtain a precursor of the membrane body 10, and melt-processable ( below in some cases referred to as "fluorine-containing polymer (s)"), the membrane body 10 can be obtained by converting a precursor of an ion exchange group into an ion exchange group.

[0183] The fluorine-containing polymer (s) can be obtained, for example, by copolymerizing at least one monomer selected from the next first group and at least one monomer selected from the next second group and / or the next third group. The fluorine-containing polymer (s) can also be obtained by homopolymerizing one monomer selected from any of the next first group, the next second group, and the next third group.

[0184] Examples of monomers of the first group include vinyl fluoride compounds. Examples of vinyl fluoride compounds include vinyl fluoride, tetrafluoroethylene, hexafluoropropylene, vinylidene fluoride, trifluoroethylene, chlorotrifluoroethylene, and perfluoroalkyl vinyl ethers. In particular, when an ion exchange membrane is used as a membrane for alkaline electrolysis, the vinyl fluoride compound is preferably a perfluorinated monomer, and a perfluorinated monomer selected from the group consisting of tetrafluoroethylene, hexafluoropropylene and perfluoroalkyl vinyl ethers is preferred.

[0185] Examples of monomers of the second group include vinyl compounds having a functional group convertible to an ion exchange group of the carboxylic acid type (carboxylic acid group). Examples of vinyl compounds having a functional group convertible to a carboxylic acid ion exchange group include monomers represented by the formula CF ₂ = CF (OCF ₂ CYF) _s –O (CZF) _t –COOR, in which s is an integer from 0 to 2, t is an integer from 1 to 12, each of Y and Z is independently F or CF ₃ and R is a lower alkyl group (a lower alkyl group is an alkyl group having, for example, 1 to 3 carbon atoms).

[0186] Among them, preferred are compounds represented by the formula CF ₂ = CF (OCF ₂ CYF) _n —O (CF ₂ ) _m —COOR, in which n represents an integer from 0 to 2, m represents an integer from 1 to 4, Y is F or CF ₃ and R is CH ₃ , C ₂ H ₅ or C ₃ H ₇ .

[0187] When the ion exchange membrane is used as a cation exchange membrane for alkaline electrolysis, the perfluoro compound is preferably used at least as a monomer, but the alkyl group (see R values above) of the ester group is lost from the polymer during hydrolysis, and therefore the alkyl group (R) is not must necessarily be a perfluoroalkyl group in which all hydrogen atoms are replaced by fluorine atoms.

[0188] Of the above monomers, the following monomers are more preferred as monomers of the second group:

CF ₂ = CFOCF ₂ –CF (CF ₃ ) OCF ₂ COOCH ₃ ,

CF ₂ = CFOCF ₂ CF (CF ₃ ) O (CF ₂ ) ₂ COOCH ₃ ,

CF ₂ = CF [OCF ₂ –CF (CF ₃ )] ₂ O (CF ₂ ) ₂ COOCH ₃ ,

CF ₂ = CFOCF ₂ CF (CF ₃ ) O (CF ₂ ) ₃ COOCH ₃ ,

CF ₂ = CFO (CF ₂ ) ₂ COOCH ₃ and

CF ₂ = CFO (CF ₂ ) ₃ COOCH ₃ .

[0189] Examples of monomers of the third group include vinyl compounds having a functional group convertible to an ion exchange group of the sulfone type (sulfonic acid group). As vinyl compounds having a functional group convertible to a sulfonic acid ion exchange group, for example, monomers represented by the formula CF ₂ = CFO — X — CF ₂ —SO ₂ F in which X is a perfluoroalkylene group are preferred. Specific examples include the following monomers:

CF ₂ = CFOCF ₂ CF ₂ SO ₂ F,

CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₂ F,

CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ CF ₂ SO ₂ F,

CF ₂ = CF (CF ₂ ) ₂ SO ₂ F,

CF ₂ = CFO [CF ₂ CF (CF ₃ ) O] ₂ CF ₂ CF ₂ SO ₂ F and

CF ₂ = CFOCF ₂ CF (CF ₂ OCF ₃ ) OCF ₂ CF ₂ SO ₂ F.

[0190] Among them, CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ CF ₂ SO ₂ F and CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₂ F are more preferable.

[0191] The copolymer obtained from these monomers can be formed by a polymerization process designed for homopolymerization and copolymerization of ethylene fluoride, in particular by a general polymerization process used for tetrafluoroethylene. For example, in a method using a non-aqueous medium, the polymerization reaction can be carried out in the presence of a free radical polymerization initiator such as a perfluorocarbon peroxide or an azo compound, under conditions of a temperature of 0 to 200 ° C and a pressure of 0.1 to 20 MPa, using an inert solvent, such as a perfluorocarbon or a chlorofluorocarbon.

[0192] In the above copolymerization, the type of combination of the above monomers and their proportions are not particularly limited and are determined depending on the type and amount of functional groups that it is desirable to introduce into the resulting fluorine-containing polymer. For example, when a fluorine-containing polymer containing only a carboxylic acid group is produced, at least one polymer must be selected from each of the above-described first group and second group and copolymerized. In addition, when a fluorine-containing polymer containing only a sulfonic acid group is prepared, at least one polymer must be selected from each of the first group and the third group, and copolymerized. In addition, when a fluorine-containing polymer having a carboxylic acid group and a sulfonic acid group is produced, at least one monomer must be selected from each of the above-described first group, second group and third group and copolymerized. In this case, the target fluorine-containing polymer can also be obtained by separately forming a copolymer including monomers of the above-described first group and second group, and a copolymer including monomers of the above-described first group and third group, and then mixing these copolymers. The composition of the mixture of monomers is not particularly limited, and when the number of functional groups per structural unit of the polymer increases, the proportion of monomers selected from the above-described second group and third group must increase.

[0193] The total ion exchange capacity of the fluorine-containing copolymer is not particularly limited, but is preferably 0.5 to 2.0 mg⋅eq / g, more preferably 0.6 to 1.5 mg⋅eq / g. The total ion exchange capacity here refers to the equivalent of the exchange group per unit weight of dry resin and can be measured by neutralization titration or the like.

[0194] In the membrane body 10 of the ion exchange membrane 1, a sulfonic acid layer 3 containing a fluorine-containing polymer having a sulfonic acid group and a carboxylic acid layer 2 containing a fluorine-containing polymer having a carboxylic acid group are laminated. By providing the membrane body 10 having such a layer configuration, the selective permeability to cations such as sodium ions can be further improved.

[0195] The ion exchange membrane 1 is placed in the electrolytic cell so that generally the sulfonic acid layer 3 is on the anode side of the cell and the carboxylic acid layer 2 is on the cathode side of the cell.

[0196] The sulfonic acid layer 3 is preferably composed of a material having a low electrical resistance and is thicker than the carboxylic acid layer 2 in terms of membrane strength. The thickness of the sulfonic acid layer 3 is preferably 2 to 25 times, more preferably 3 to 15 times the thickness of the carboxylic acid layer 2.

[0197] The carboxylic acid layer 2 preferably has high anion exclusion characteristics even if it is thin. The anion exclusion characteristics herein refer to the characteristic of hindering the incorporation and penetration of anions into or through the ion exchange membrane 1. In order to improve the anion exclusion characteristics, it is effective to place a carboxylic acid layer having a low ion exchange capacity compared to the sulfonic acid layer.

[0198] As the fluorine-containing polymer for use in the sulfonic acid layer 3, a polymer obtained using CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₂ F as the third group monomer is preferable.

[0199] As the fluorine-containing polymer for use in the carboxylic acid layer 2, a polymer obtained using CF ₂ = CFOCF ₂ CF (CF ₂ ) O (CF ₂ ) ₂ COOCH _{3 is} preferred as the monomer of the second group.

[0200] (Coating layer)

The ion exchange membrane has a coating layer on at least one surface of the membrane body. As shown in Figure 23, in the ion exchange membrane 1, coating layers 11a and 11b are formed on both surfaces of the membrane body 10.

The coating layers contain particles of inorganic material and a binder.

[0201] The average particle size of the inorganic material is preferably 0.90 µm or more. When the average particle size of the inorganic material is 0.90 µm or more, impurity resistance is greatly improved in addition to gas attachment. That is, by increasing the average particle size of the inorganic material as well as keeping the above-mentioned specific surface area, a particularly noticeable effect can be achieved. Uneven particles of inorganic material are preferred insofar as the above average particle size and specific surface area are satisfied. Melting inorganic material particles and raw ore milling inorganic material particles can be used. Preferably, particles of inorganic material obtained by milling raw ore are used.

[0202] The average particle size of the particles of the inorganic material may be 2 µm or less. When the average particle size of the inorganic material is 2 µm or less, damage to the membrane by the inorganic material can be prevented. The average particle size of the inorganic material is more preferably 0.90 to 1.2 µm.

[0203] Here, the average particle size can be measured with a particle size analyzer ("SALD2200", manufactured by SHIMADZU CORPORATION).

[0204] The particles of inorganic material are preferably irregular in shape. Such shapes further improve the resistance to impurities. The particles of inorganic material preferably have a wide particle size distribution.

[0205] The particles of inorganic material preferably contain at least one inorganic material selected from the group consisting of oxides of Group IV elements of the Periodic Table, nitrides of Group IV elements of the Periodic Table, and carbides of Group IV elements of the Periodic Table. From the standpoint of resistance, zirconium oxide particles are more preferable.

[0206] The inorganic material particles are preferably inorganic material particles obtained by grinding raw ore from inorganic material particles, or inorganic material particles in the form of spherical particles having a uniform diameter obtained by refining a raw ore melt from inorganic material particles.

[0207] Examples of means for grinding raw ore include, but are not specifically limited to, ball mills, bead mills, colloid mills, cone grinders, disc mills, runners, grain mills, hammer mills, granulators, vertical shaft impact crushers (VSI ), leather mills (Wiley mills), roller mills and jet mills. After grinding, the particles are preferably washed. As a washing method, the particles are preferably treated with an acid. This treatment can reduce the amount of impurities such as iron adhered to the surface of the inorganic material particles.

[0208] The coating layer preferably contains a binder. The binder is the component that forms the coating layers by retaining particles of inorganic material on the surface of the ion exchange membrane. The binder preferably contains a fluorine-containing polymer from the standpoint of resistance to electrolyte solution and electrolysis products.

[0209] As the binder, a fluorine-containing polymer having a carboxylic acid group or a sulfonic acid group is more preferable in terms of resistance to electrolyte solution and electrolysis products and adhesion strength to the surface of the ion exchange membrane. When the coating layer is provided on a layer containing a fluorine-containing polymer having a sulfonic acid group (sulfonic acid layer), the fluorine-containing polymer having a sulfonic acid group is even more preferably used as a binder for the coating layer. Alternatively, when the coating layer is provided on a layer containing a fluorine-containing polymer having a carboxylic acid group (carboxylic acid layer), a fluorine-containing polymer having a carboxylic acid group is more preferably used as a binder for the coating layer.

[0210] The content of the particles of inorganic material in the coating layer is preferably 40 to 90% by mass, more preferably 50 to 90% by mass. The content of the binder is preferably 10 to 60% by mass, more preferably 10 to 50% by mass.

[0211] The distribution density of the coating layer in the ion exchange membrane is preferably 0.05 to 2 mg per cm ² . When the ion exchange membrane has ridges (roughness) on its surface, the distribution density of the coating layer is preferably 0.5 to 2 mg per cm ² .

[0212] As a method for manufacturing the coating layer, which is not particularly limited, a known method can be applied. An example is a method comprising applying by spray or the like a coating liquid obtained by dispersing particles of an inorganic material in a solution containing a binder.

[0213] (Core Reinforcement Materials)

The ion exchange membrane preferably has core reinforcing materials disposed within the membrane body.

[0214] Reinforcing materials of the core are elements that increase the strength and dimensional stability of the ion exchange membrane. By placing the reinforcing materials of the core within the body of the membrane, it is possible, in particular, to control the expansion and contraction of the ion exchange membrane in the desired range. Such an ion exchange membrane does not expand or contract more than necessary during electrolysis and the like, and can maintain excellent dimensional stability for a long time.

[0215] The configuration of the core reinforcing materials is not particularly limited, and, for example, the core reinforcing materials may be formed by woven yarns called reinforcing yarns. Reinforcing yarns herein refer to yarns that constitute the constituent core reinforcing materials, can provide the desired dimensional stability and mechanical strength to the ion exchange membrane, and can be stably present in the ion exchange membrane. By using core reinforcing materials obtained by weaving such reinforcing yarns, better dimensional stability and mechanical strength can be imparted to the ion exchange membrane.

[0216] The material of the reinforcing materials of the core and the reinforcing yarns used therefor is not particularly limited, but is preferably a material resistant to acids, alkalis, etc., and a fiber including a fluorine-containing polymer is preferable since long-term heat resistance and chemical resistance are required. ...

[0217] Examples of the fluoropolymer used in the reinforcing materials of the core include polytetrafluoroethylene (PTFE), copolymers of tetrafluoroethylene and perfluoroalkyl vinyl ether (PFA), copolymers of tetrafluoroethylene and ethylene (ETFE), copolymers of tetrafluoroethylene copolymers and copolymers of tetrafluoroethylene copolymers and copolymers of tetrafluoroethylene copolymers PVDF). Among them, fibers including polytetrafluoroethylene are preferably used in terms of heat resistance and chemical resistance.

[0218] The diameter of the reinforcing yarns used for the core reinforcing materials is not particularly limited, but is preferably 20 to 300 denier, more preferably 50 to 250 denier. The weave density (web density per unit length) is preferably 5 to 50 / inch. The shape of the core reinforcing materials is not particularly limited, for example, woven fabric, non-woven fabric and knitted fabric are used, but preferably in the form of woven fabric. The thickness of the woven fabric used is preferably 30 to 250 µm, more preferably 30 to 150 µm.

[0219] As the woven fabric or knitted fabric, monofilaments, multifilaments or yarns thereof, twisted yarns with dangling yarns or the like can be used, and various types of weaving methods can be used such as plain weave, leno weave, knitted weave, cord weave and seersucker.

[0220] The braiding and placement of the core reinforcing materials in the membrane body are not particularly limited, and the preferred placement can be appropriately provided in consideration of the size and shape of the ion exchange membrane, physical properties desired for the ion exchange membrane, environmental conditions in use, and the like.

[0221] For example, the core reinforcing materials may be placed along a predetermined direction of the membrane body, but from a dimensional stability point of view, it is preferable that the core reinforcing materials are placed along the predetermined first direction, and other core reinforcing materials are placed along the predetermined second direction along essentially perpendicular to the first direction. By placing multiple core reinforcement materials substantially orthogonal within the membrane body, better dimensional stability and mechanical strength in many directions can be imparted. For example, a configuration is preferable in which core reinforcing materials disposed along the longitudinal direction (warp yarns) and core reinforcing materials disposed along the transverse direction (weft yarns) are woven on the surface side of the membrane body. A more preferred configuration is in the form of a plain weave, made and woven by allowing the warp and weft yarns to pass alternately above and below each other, a leno in which the two base yarns are woven with twist weft yarns, a matting weave made and woven by inserting the same number of weft yarns or the like into two or more parallel warp yarns, or the like, from the standpoint of dimensional stability, mechanical strength and ease of manufacture.

[0222] It is particularly preferred that the core reinforcing materials are disposed along both directions MD (longitudinal direction) and TD (transverse direction) of the ion exchange membrane. In other words, the core reinforcing materials are preferably plain weave in MD and TD. Here, MD means the direction in which the membrane body and various core materials (for example, reinforcing core materials, reinforcing yarns and consumable yarns described later) move in the later described stage of obtaining the ion exchange membrane (flow direction), and TD means a direction substantially perpendicular to MD ... The yarns weaved along the MD are called MD yarns, and the yarns weaved along the TD are called TD yarns. Typically, the ion exchange membrane used for electrolysis is rectangular, and in many cases, the longitudinal direction is MD and the width direction is TD. By weaving reinforcing core materials that are MD yarns and reinforcing core materials that are TD yarns, better dimensional stability and mechanical strength can be achieved in many directions.

[0223] The placement range of the core reinforcing materials is not particularly limited, and the preferred placement can be appropriately provided in consideration of the physical properties desired for the ion exchange membrane, the environmental conditions in use, and the like.

[0224] The opening ratio of the core reinforcing materials is not particularly limited, but is preferably 30% or more, more preferably 50% or more and 90% or less. The opening ratio is preferably 30% or more in terms of the electrochemical characteristics of the ion exchange membrane, and preferably 90% or less in terms of the mechanical strength of the ion exchange membrane.

[0225] The opening ratio of the reinforcing materials of the core herein refers to the ratio (B / A) of the total surface area (B) through which substances such as ions (electrolyte solution and cations (eg sodium ions) contained therein) can pass to area (A) of any one surface of the body of the ion-exchange membrane. The total surface area (B) through which substances such as ions can pass may refer to the total areas of regions in which cations, electrolyte solution and the like are not retained in the ion exchange membrane by the reinforcing materials of the core and the like contained in the ion exchange membrane. membrane.

[0226] Figure 24 illustrates a schematic view for explaining the relative opening of the core reinforcement materials constituting the ion exchange membrane. Figure 24, in which a portion of the ion exchange membrane is shown enlarged, shows only the configuration of the reinforcing materials 21 and 22 of the core in these regions, without showing other elements.

[0227] By subtracting the total area (C) of the core reinforcing materials from the area of the area surrounded by the core reinforcing materials 21 along the longitudinal direction and the core reinforcing materials 22 located along the transverse direction, the area including the area (A) of the core reinforcing materials can the total area (B) of the regions through which substances such as ions can pass in the area (A) of the above-described region can be obtained. That is, the relative aperture can be determined by the following formula (I):

Relative aperture = (B) / (A) = ((A) - (C)) / (A) (I)

[0228] Among the reinforcing materials of the core, a film textile thread (yarn) or highly oriented monofilaments including PTFE are particularly preferred in terms of chemical resistance and heat resistance. More specifically, more preferred are plain weave core reinforcing materials that use 50 to 300 denier film textile yarns made by cutting a PTFE-containing high tenacity porous sheet into ribbon-shaped pieces, or comprising highly oriented PTFE monofilaments of 50 to 300 denier sizes. 300 denier, and which have a weave density of 10 to 50 threads or monofilaments per inch and have a thickness in the range of 50 to 100 microns. The opening ratio of the ion exchange membrane including such core reinforcing materials is more preferably 60% or more.

[0229] Examples of the shape of the reinforcing yarns include round yarns and film yarns.

[0230] (Through Holes)

The ion exchange membrane preferably has through holes within the membrane body.

[0231] Through holes refer to holes that can form passages for ions generated during electrolysis and for an electrolyte solution. Through holes, which are tubular holes formed within the membrane body, are formed by dissolving the core consumables (or yarns) described below. The shape, diameter, or the like of the through holes can be controlled by selecting the shape or diameter of the core consumables (yarn consumables).

[0232] The formation of through holes within the ion exchange membrane can provide mobility of the electrolyte solution during electrolysis. The shape of the through holes is not particularly limited, but may be the shape of the core consumable materials used to form the through holes according to the production method described below.

[0233] The through holes are preferably formed to alternately extend on the anode side (sulfonic acid layer side) and cathode side (carboxylic acid layer side) of the core reinforcing materials. With this arrangement, in the region in which the through holes are formed on the cathode side of the core reinforcing materials, ions (such as sodium ions) supplied by the electrolyte solution filling the through holes can also flow to the cathode side of the core reinforcing materials. As a result, the flow of cations is not interrupted, and thus an additional reduction in the electrical resistance of the ion-exchange membrane is possible.

[0234] The through holes may be formed along only one predetermined direction of the membrane body constituting the ion exchange membrane, but are preferably formed along both the longitudinal direction and the transverse direction of the membrane body in view of exhibiting more stable electrolysis characteristics.

[0235] [Manufacturing Method]

A suitable example of a method for manufacturing an ion exchange membrane includes a method comprising the following steps (1) to (6):

Step (1): a step for producing a fluorine-containing polymer having an ion exchange group or an ion exchange group precursor capable of forming an ion exchange group by hydrolysis.

Step (2): a step of weaving at least a plurality of core reinforcing materials, if necessary, and consumable yarns that dissolve in acid or alkali and form through holes, to obtain a reinforcing material in which the consumable yarns are interposed between the core reinforcing materials, being adjacent to each other.

Step (3): a step of converting into a film the above fluorine-containing polymer having an ion exchange group or an ion exchange group precursor capable of forming an ion exchange group by hydrolysis.

Step (4): the step of introducing the above reinforcing materials, if necessary, into the above film to obtain a membrane body, inside which the reinforcing materials are placed.

Stage (5): stage of hydrolysis of the membrane body obtained in stage (4) (stage of hydrolysis) and

Step (6): The step of creating a coating layer on the membrane body obtained in step (5) (application step).

[0236] Next, each of the steps will be described in detail.

[0237] Step (1): the step of obtaining a fluoropolymer

In step (1), the monomeric starting materials described above in groups one to three are used to prepare the fluoropolymer. To regulate the ion-exchange capacity of the fluorine-containing polymer, the composition of the mixture of the starting monomer materials must be controlled during the production of the fluorine-containing polymer forming the said layers.

[0238] Step (2): the step of obtaining reinforcing materials

The reinforcing material is a woven fabric obtained by weaving reinforcing yarns or the like. The reinforcing material is embedded in the membrane to thereby form core reinforcing materials. When an ion-exchange membrane with through holes is formed, consumable yarns are additionally woven into the reinforcing material. The amount of consumable yarns contained in this case is preferably 10 to 80% by mass, more preferably 30 to 70% by mass, based on the total reinforcing material. The weaving of the consumable yarns can also prevent slippage of the yarns of the core reinforcing materials.

[0239] Viscose, polyethylene terephthalate (PET), cellulose, polyamide and the like are used as the consumable yarns that are dissolved in the membrane production step or in the electrolysis environment. Also preferred are monofilaments or multifilaments having a thickness of 20 to 50 denier and including polyvinyl alcohol and the like.

[0240] In step (2), the aperture ratio, the placement of the through holes, and the like can be controlled by adjusting the placement of the core reinforcing materials and the yarns consumed.

[0241] Step (3): Film forming step

In step (3), the fluoropolymer obtained in step (1) is formed into a film using an extruder. The film may have a single layer configuration, a two layer configuration of a sulfonic acid layer and a carboxylic acid layer as mentioned above, or a multilayer configuration of three or more layers.

[0242] Examples of the film forming method include the following:

a method in which a fluorine-containing polymer having a carboxylic acid group and a fluorine-containing polymer having a sulfonic acid group are separately formed into films; and

a method in which a fluorine-containing polymer having a carboxylic acid group and a fluorine-containing polymer having a sulfonic acid group are coextruded to form a composite film.

[0243] The number of each film can be more than one. Co-extrusion of different films is preferred because of their contribution to the increase in bond strength at the interface.

[0244] Step (4): The step of obtaining the membrane body

In step (4), the reinforcing material obtained in step (2) is embedded in the film obtained in step (3) to form a membrane body containing the reinforcing material.

[0245] Preferred examples of a method for forming a membrane body include (i) a method in which a fluorine-containing polymer having a precursor of a carboxylic acid group (e.g., a carboxylate functional group) (hereinafter referred to as a first layer) disposed on the cathode side and a fluorine-containing polymer having a precursor of a sulfonic acid group (for example, a sulfonyl fluoride functional group) (hereinafter, including this layer is called the second layer), is formed into a film by the method of coextrusion, and, if necessary, using a heat source and a vacuum source, a reinforcing material and a composite film from the second layer / the first layer is laminated in this order onto a breathable heat-resistant release paper on a flat plate or drum having numerous pores on their surface and combined at a temperature at which each polymer melts while at the same time evacuating air from under each of the layers by means of reduced pressure ; and (ii) a method in which, in addition to the composite film of the second layer / first layer, a fluorine-containing polymer having a precursor of a sulfonic acid group is separately preformed into a film (third layer), and optionally using a heat source and a source vacuum, the third layer film, the core reinforcing materials and the composite film from the second layer / first layer are laminated in this order on a breathable heat-resistant release paper on a flat plate or drum having multiple pores on their surface and combined at a temperature at which each polymer is melted while pumping air out from under each of the layers by means of reduced pressure.

[0246] Co-extrusion of the first and second layer here helps to increase the bond strength at the interface.

[0247] The method of combining under reduced pressure is characterized by making the third layer on the reinforcing material thicker than in the press-applied method. In addition, since the reinforcing material is fixed to the inner surface of the membrane body, the method provides sufficient retention of the mechanical strength of the ion exchange membrane.

[0248] Embodiments of the layering methods described herein are exemplary, and coextrusion may be performed after a preferred layering configuration (eg, a combination of layers) is appropriately selected in consideration of the desired membrane body layer configurations and physical properties, and the like.

[0249] In order to further improve the electrical characteristics of the ion exchange membrane, it is also possible to additionally place a fourth layer comprising a fluorine-containing polymer having both a precursor of a carboxylic acid group and a precursor of a sulfonic acid group between the first layer and the second layer, or the use of a fourth layer comprising a fluorine-containing polymer having both a precursor of a carboxylic acid group and a precursor of a sulfonic acid group instead of the second layer.

[0250] The method for forming the fourth layer may be a method in which a fluorine-containing polymer having a precursor of a carboxylic acid group and a fluorine-containing polymer having a precursor of a sulfonic acid group are separately prepared and then mixed, or it may be a method in which a monomer is copolymerized having a precursor of a carboxylic acid group; and a monomer having a sulfonic acid precursor.

[0251] When the fourth layer is used as a component of the ion exchange membrane, a coextruded film of the first layer and the fourth layer is formed, in addition, the third layer and the second layer are separately formed into films, and the laminating can be performed in the above manner. Alternatively, three layers of the first layer / fourth layer / second layer can be coextruded simultaneously to form a film.

[0252] In this case, the direction in which the extruded film flows out is MD. As mentioned above, it is possible to form a membrane body containing a fluorine-containing polymer having an ion exchange group on the reinforcing material.

[0253] In addition, the ion exchange membrane preferably has protrusions constituted by a fluoropolymer having a sulfonic acid group, that is, protrusions on the side of the surface constituted by the sulfonic acid layer. As a method for forming such protrusions, which is not particularly limited, a known method including forming protrusions on a resin surface can also be applied. A specific example of the method is a method for embossing the surface of a membrane body. For example, the aforementioned protrusions can be formed using the pre-embossed release paper when the above composite film, reinforcing material, and the like are combined. In the case where the protrusions are formed by embossing, the height and density of the protrusions can be controlled by the shape of the transferred relief (the shape of the release paper).

[0254] (5) Hydrolysis Step

At step (5), the stage of hydrolysis of the membrane body obtained at stage (4) is performed to convert the precursor of the ion-exchange group into an ion-exchange group (stage of hydrolysis).

[0255] In step (5), it is also possible to dissolve holes in the membrane body by dissolving and removing consumable yarns introduced into the membrane body by the action of an acid or alkali. The consumable yarns can remain in the through holes without being completely dissolved and removed. The consumable yarns remaining in the through holes can be dissolved and removed by the electrolyte solution when the ion exchange membrane is subjected to electrolysis.

[0256] The consumable yarn is dissolved in acid or alkali during the ion exchange membrane preparation step or in the electrolysis environment. The consumable yarns are washed out, thereby forming the through-holes at the appropriate locations.

[0257] Step (5) may be performed by immersing the membrane body obtained in step (4) in a hydrolysis solution containing an acid or alkali. An example of a hydrolysis solution that can be used is a mixed solution containing KOH and dimethyl sulfoxide (DMSO).

[0258] The mixed solution preferably contains KOH at a normal concentration of 2.5 to 4.0 and DMSO of 25 to 35% by weight.

[0259] The temperature in the hydrolysis is preferably 70 to 100 ° C. The higher the temperature, the greater the apparent thickness can be. The temperature is more preferably 75 to 100 ° C.

[0260] The duration of the hydrolysis is preferably 10 to 120 minutes. The longer the hydrolysis takes, the greater the apparent thickness can be. The duration of the hydrolysis is preferably 20 to 120 minutes.

[0261] The step of forming the through holes by washing out the sacrificial yarns will now be described in more detail. Figures 25 (a) and (b) are schematic views for explaining a method of forming vias in an ion exchange membrane.

[0262] Figures 25 (a) and (b) show reinforcing yarns 52, sacrificial yarns 504a and through holes 504 formed only by sacrificial yarns 504a, without illustrating other features such as a membrane body.

[0263] First, the reinforcing yarns 52, which are to constitute the core reinforcing materials in the ion exchange membrane, and the consumable yarns 504a for forming the through holes 504 in the ion exchange membrane are used as interlaced reinforcing materials. Then, in step (5), the consumable yarns 504a are washed out to form the through holes 504.

[0264] The above method is simple because the method of interlacing the reinforcing yarns 52 and the consumable yarns 504a can be adjusted depending on the placement order of the core reinforcing materials and the through holes in the body of the ion exchange membrane.

[0265] Figure 25 (a) illustrates an example of a plain weave reinforcing material in which the reinforcing yarns 52 and the sacrificial yarns 504a are interlaced in both the longitudinal direction and the transverse direction in the paper, and optionally the order of placement of the reinforcing yarns 52 and the sacrificial yarn 504a in the reinforcing material can be changed.

[0266] (6) Application Stage

In step (6), a coating layer can be formed by preparing a coating liquid containing particles of inorganic material obtained by grinding raw ore or melting raw ore and a binder, applying a coating liquid to the surface of the ion exchange membrane obtained in step (5), and drying the coating liquids.

[0267] A preferred binder is a binder obtained by hydrolysis of a fluorine-containing polymer having an ion exchange group precursor with an aqueous solution containing dimethyl sulfoxide (DMSO) and potassium hydroxide (KOH), and then immersing the polymer in hydrochloric acid to replace the counter ion of the ion exchange group with H ⁺ ( for example, a fluorine-containing polymer having a carboxyl group or a sulfo group). Thus, the polymer is more likely to dissolve in water or ethanol, as mentioned below, which is preferred.

[0268] This binder is dissolved in a mixed solution of water and ethanol. The volume ratio between water and ethanol is preferably 10: 1 to 1:10, more preferably 5: 1 to 1: 5, even more preferably 2: 1 to 1: 2. The particles of inorganic material are dispersed in the dissolving liquid by means of a ball mill, thereby forming a coating liquid. In this case, it is also possible to correct the average particle size and the like of particles by adjusting the duration and speed of rotation during dispersion. The preferred amount of the mixed particles of inorganic material and binder is as mentioned above.

[0269] The concentration of the particles of inorganic material and binder in the coating liquid is not particularly limited, but a free-flowing coating liquid is preferable. This makes it possible to uniformly apply the ion exchange membrane to the surface.

[0270] In addition, a surfactant may be added to the dispersion when particles of inorganic material are dispersed. As the surfactant, nonionic surfactants are preferred and examples include HS-210, NS-210, P-210 and E-212 from NOF CORPORATION.

[0271] The resulting coating liquid is applied to the surface of the ion exchange membrane by a spray application or roller coating, thereby forming an ion exchange membrane.

[0272] [Microporous Membrane]

The microporous membrane of the present embodiment is not particularly limited as long as the membrane can be formed to form an electrode laminated article for electrolysis as mentioned above. A variety of microporous membranes can be used.

The porosity of the microporous membrane of the present embodiment is not particularly limited, but may be, for example, 20 to 90, and preferably 30 to 85. The above porosity can be calculated by the following formula:

Porosity = (1– (dry weight of the membrane) / (weight calculated from the volume, calculated from the values of the thickness, width and length of the membrane, and the density of the membrane material)) × 100

The average pore size in the microporous membrane of the present embodiment is not particularly limited and may be, for example, 0.01 µm to 10 µm, preferably 0.05 µm to 5 µm. With regard to the average pore size, for example, the membrane is cut vertically in the direction of thickness, and the cross section is examined by field emission scanning electron microscopy (FE-SEM). The average pore size can be obtained by measuring the diameter of about 100 pores and averaging the results.

The thickness of the microporous membrane of the present embodiment is not particularly limited and may be, for example, 10 µm to 1000 µm, preferably 50 µm to 600 µm. The above thickness can be measured using, for example, a micrometer (manufactured by Mitutoyo Corporation) or the like.

Specific examples of a microporous membrane as above include Zirfon Perl UTP 500 manufactured by Agfa (also referred to as a Zirfon membrane in this embodiment) and are described in International Publication No. WO 2013-183584 and International Publication No. WO 2016-203701.

[0273] The reason why the layered article of the present embodiment provides excellent electrolysis performance is assumed as follows. When the membrane and electrode are pressed tightly against each other in a manner such as thermocompression, which is the standard method, the electrode is pressed into the membrane and thereby physically adheres (adheres) to it. This adhered region prevents the migration of sodium ions into the membrane, thereby significantly increasing the electrical voltage. Meanwhile, suppression of migration of sodium ions into the membrane, which has been a problem in the prior art, is eliminated by the fact that the electrolysis electrode is adjacent to the membrane or to the supply conductor with a moderate adhesion force, as in the present embodiment. According to the above, when the membrane or the supply conductor is adjacent to the electrolysis electrode with a moderate adhesive force, the membrane or the supply conductor and the electrolysis electrode, although they constitute an integrated unit, can provide excellent electrolysis performance.

[0274] [Winding]

The winding of the present embodiment comprises the laminated article of the present embodiment. That is, the winding of the present embodiment is obtained by winding the laminated article of the present embodiment. Reducing the size of the laminated article of the present embodiment by winding in the form of the winding of the present embodiment can further improve workability.

[0275] [Electrolyzer]

The electrolyzer of the present embodiment comprises the laminated article of the present embodiment. Next, a case of performing conventional salt electrolysis using an ion exchange membrane as the membrane will be given by way of example, and one embodiment of the electrolytic cell will be described in detail.

[0276] [Electrolytic Cell]

Figure 26 illustrates a sectional view of an electrolytic cell 1.

The electrolytic cell 1 contains an anode chamber 10, a cathode chamber 20, a dividing wall 30 located between the anode chamber 10 and the cathode chamber 20, an anode 11 located in the anode chamber 10, and a cathode 21 located in the cathode chamber 20. If necessary, an electrolytic cell 1 has a substrate 18a and a reverse current absorbing layer 18b formed on the substrate 18a, and may include a reverse current absorber 18 disposed in the cathode chamber. The anode 11 and the cathode 21, which are part of the electrolytic cell 1, are electrically connected to each other. In other words, the electrolytic cell 1 contains the following cathode structure. The cathode structure 40 comprises a cathode chamber 20, a cathode 21 disposed in the cathode chamber 20, and a reverse current absorber 18 disposed in the cathode chamber 20, the reverse current absorber 18 having a substrate 18a and a reverse current absorbing layer 18b formed on the substrate 18a as shown in Figure 30, and the cathode 21 and the reverse current absorbing layer 18b are electrically connected. In addition, the cathode chamber 20 has a current collector 23, a holder 24 supporting the current collector, and a metal elastic body 22. The metal elastic body 22 is placed between the current collector 23 and the cathode 21. The holder 24 is located between the current collector 23 and the partition 30. The current collector 23 is electrically connected to cathode 21 through the metal elastic body 22. The separating partition 30 is electrically connected to the current collector 23 through the holder 24. Accordingly, the separating partition 30, the holder 24, the current collector 23, the metal elastic body 22 and the cathode 21 are electrically connected to each other. The cathode 21 and the reverse current absorbing layer 18b are electrically connected. The cathode 21 and the reverse current absorbing layer may be connected directly, or may be connected indirectly through a down conductor, a holder, a metal resilient body, a baffle, or the like. The entire surface of the cathode 21 is preferably coated with a catalyst layer for the reduction reaction. The form of the electrical connection may be a form in which the baffle 30 and the support 24, the support 24 and the collector 23 and the collector 23 and the metal resilient body 22 are in each case directly connected to each other, and the cathode 21 is laminated on the metal resilient body 22. Examples methods for directly attaching these structural elements to each other include welding and the like. Alternatively, the reverse current absorber 18, cathode 21, and current collector 23 may be collectively referred to as cathode structure 40.

[0277] Figure 27 illustrates a cross-sectional view of two electrolytic cells 1 that are adjacent in electrolytic cell 4. Figure 28 shows electrolytic cell 4. Figure 29 shows a step of assembling electrolytic cell 4. As shown in Figure 27, electrolytic cell 1, cation exchange membrane 2 and electrolytic cell 1 are placed sequentially in the order shown. The ion exchange membrane 2 is placed between the anode chamber of one electrolytic cell 1 of two electrolytic cells that are adjacent in the electrolyzer and the cathode chamber of another electrolytic cell 1. That is, the anode chamber 10 of the electrolytic cell 1 and the cathode chamber 20 of the adjacent electrolytic cell 1 are separated by a cation exchange membrane 2. As shown in Figure 28, electrolyzer 4 consists of a plurality of electrolytic cells 1 connected in series through an ion exchange membrane 2. That is, electrolyzer 4 is a bipolar electrolyzer including a plurality of electrolytic cells 1 in series and ion exchange membranes 2, in each case arranged between adjacent electrolytic cells 1. As shown in Figure 29, cell 4 is assembled by placing a plurality of electrolytic cells 1 in series through the ion exchange membrane 2 and bonding the cells by means of a clamping device 5.

[0278] The cell 4 has an anode terminal 7 and a cathode terminal 6 that are connected to a power supply. An anode 11 of an electrolytic cell 1 located at the farthest end of a plurality of electrolytic cells 1 connected in series in an electrolysis cell 4 is electrically connected to an anode terminal 7. A cathode 21 of an electrolytic cell located at an end opposite to the anode terminal 7 among the plurality of electrolytic cells 1, connected in series in the electrolytic cell 4, electrically connected to the cathode terminal 6. Electric current during electrolysis flows from the side of the anode terminal 7 through the anode and the cathode of each electrolytic cell 1 towards the cathode terminal 6. At both ends of the connected electrolytic cells 1 there may be an electrolytic cell, having only an anode chamber (anode outlet cell), and an electrolytic cell having only a cathode chamber (cathode outlet cell). In this case, the anode terminal 7 is connected to an anode terminal cell located at one end, and the cathode terminal 6 is connected to a cathode terminal cell located at the other end.

[0279] In the case of brine electrolysis, brine is supplied to each anode chamber 10, and pure water or low concentration aqueous sodium hydroxide solution is supplied to each cathode chamber 20. Each liquid is supplied from an electrolyte solution supply pipe (not shown) through a hose for supplying an electrolyte solution (not shown in the figure) to each electrolytic cell 1. The electrolyte solution and electrolysis products are removed from the pipe for removing the electrolyte solution (not shown in the figure). During electrolysis, sodium ions in the brine migrate from the anode chamber 10 of one electrolytic cell 1 through the ion exchange membrane 2 to the cathode chamber 20 of the adjacent electrolytic cell 1. Thus, the electric current during electrolysis flows in the direction in which the electrolytic cells 1 are connected in series. That is, an electric current flows through the cation exchange membrane 2 from the anode chamber 10 towards the cathode chamber 20. When the brine is electrolyzed, chlorine gas is generated on the anode 11 side, and sodium hydroxide (dissolved) and hydrogen gas are generated on the cathode 21 side.

[0280] (Anode chamber)

The anode chamber 10 has an anode 11 or an anode supply conductor 11. When the electrolysis electrode of the present embodiment is inserted on the anode side, 11 serves as an anode supply conductor. When the electrolysis electrode of the present embodiment is not inserted on the anode side, 11 serves as an anode. The anode chamber 10 has an anode side electrolyte solution supply unit that supplies electrolyte solution to the anode chamber 10, a baffle plate that is positioned above the anode side electrolyte solution supply unit so as to be substantially parallel or inclined with respect to the dividing baffle 30, and an anode gas-liquid separator. side positioned above the baffle plate to separate the gas from the electrolyte solution including the admixed gas.

[0281] (Anode)

When the electrolysis electrode of the present embodiment is not inserted on the anode side, the anode 11 is in the frame of the anode chamber 10. A metal electrode such as a so-called DSA (R) can be used as the anode 11. DSA is an electrode including a titanium substrate, the surface of which is coated with an oxide including ruthenium, iridium and titanium as components.

As for the shape, any of a perforated metal sheet, a nonwoven fabric, a porous metal, an expanded metal sheet, an electrospinning metal porous foil, a so-called woven metal mesh formed by interlacing of thin metal filaments, and the like can be used.

[0282] (Anode Supply Conductor)

When the electrode for electrolysis of the present embodiment is inserted on the anode side, an anode supply conductor 11 is provided on the frame of the anode chamber 10. A metal electrode such as a so-called DSA (R) can be used as the anode supply conductor 11, and can also be used titanium without catalytic coating. Alternatively, a DSA having a thinner catalytic coating can also be used. In addition, an already used anode can also be used.

As for the shape, any of a perforated metal sheet, a nonwoven fabric, a porous metal, an expanded metal sheet, an electrospinning metal porous foil, a so-called woven metal mesh formed by interlacing of thin metal filaments, and the like can be used.

[0283] (Anode side electrolyte solution supply unit)

An anode-side electrolyte solution supply unit that supplies an electrolyte solution to the anode chamber 10 is connected to a pipe for supplying an electrolyte solution. The anode side electrolyte solution supply unit is preferably disposed under the anode chamber 10. As the anode side electrolyte solution supply unit, for example, a pipe on the surface of which lumen portions (dispersion tube) and the like can be used. Such a tube is more preferably located along the surface of the anode 11 and parallel to the bottom 19 of the electrolytic cell. This pipe is connected to a pipe for supplying an electrolyte solution (a liquid supply pipe), which supplies an electrolyte solution to an electrolytic cell 1. The electrolyte solution supplied from a liquid supply pipe is passed through a pipe into an electrolytic cell 1 and is fed from holes made on the pipe surface inside the anode chambers 10. Placing the pipe along the surface of the anode 11 and parallel to the bottom 19 of the electrolytic cell is preferable because the electrolyte solution can be uniformly supplied to the inside of the anode chamber 10.

[0284] (Anode side gas-liquid separator)

The anode-side gas-liquid separator is preferably located above the baffle plate. The purpose of the anode-side gas-liquid separator is to separate the generated gas, such as chlorine gas, from the electrolyte solution during electrolysis. Unless otherwise indicated, "above" means an upward direction in an electrolytic cell 1 in FIG. 26, and "under" means a downward direction in an electrolytic cell 1 in FIG. 26.

[0285] The gas generated during electrolysis evolved in the electrolytic cell 1 and the electrolyte solution form a mixed phase (gas-liquid mixed phase), which is then discharged from the system. As a consequence, pressure fluctuations within the electrolytic cell 1 cause vibration, which can lead to physical damage to the ion exchange membrane. To prevent this phenomenon, the electrolytic cell 1 of the present embodiment is preferably equipped with an anode-side gas-liquid separator for separating gas from liquid. The anode-side gas-liquid separator is preferably provided with a defoamer plate to eliminate bubbles. When the gas-liquid mixed phase stream flows through the defoamer plate, the bubbles burst, thereby separating the electrolyte solution and gas. As a result, vibration during electrolysis can be prevented.

[0286] (Baffle Plate)

The baffle plate is preferably positioned above the anode side electrolyte solution supply unit and is positioned substantially parallel or obliquely with respect to the baffle 30. The baffle plate is a baffle plate that controls the flow of electrolyte solution into the anode chamber 10. When the baffle plate is provided, it can cause circulation electrolyte solution (brine or the like) inside the anode chamber 10, thereby making the concentration more uniform. To create internal circulation, the baffle plate is preferably positioned so as to separate the space near the anode 11 from the space near the baffle 30. For this reason, the baffle plate is preferably positioned so that it is opposite the surface of the anode 11 and the surface of the baffle 30. In the space near the anode separated by the baffle plate, electrolysis occurs, the concentration of the electrolyte solution (brine concentration) decreases, and a generated gas such as chlorine gas is released. This leads to a difference in the specific gravity of the gas-liquid mixture between the space near the anode 11 and the space near the dividing wall 30, separated by a baffle plate. Using this difference, it is possible to stimulate the internal circulation of the electrolyte solution in the anode chamber 10, thereby making the concentration distribution of the electrolyte solution in the anode chamber 10 more uniform.

[0287] Although not shown in Figure 26, a down conductor may also optionally be provided within the anode chamber 10. The material and configuration of such a current collector can be the same as for the aforementioned collector of the cathode chamber. In the anode chamber 10, the anode 11 itself can also serve as a down conductor.

[0288] (Divider)

The dividing wall 30 is disposed between the anode chamber 10 and the cathode chamber 20. The dividing wall 30 may be referred to as a separator, and the anode chamber 10 and the cathode chamber 20 are separated from each other by a dividing wall 30. As the dividing wall 30, a baffle known as a separator can be used. electrolysis, and an example thereof comprises a baffle formed by welding a nickel-containing plate on the cathode side and a titanium-containing plate on the anode side.

[0289] (Cathode Chamber)

In the cathode compartment 20, when the electrolysis electrode of the present embodiment is inserted on the cathode side, 21 serves as a cathode supply conductor. When the electrolysis electrode of the present embodiment is not inserted on the cathode side, 21 serves as the cathode. When a return current absorber is present, the cathode or cathode supply conductor 21 is electrically connected to the return current absorber. The cathode chamber 20, like the anode chamber 10, preferably has a cathode-side electrolyte solution supply unit and a cathode-side gas-liquid separator. Among the components constituting the cathode compartment 20, components similar to those constituting the anode compartment 10 will not be described.

[0290] (Cathode)

When the electrolysis electrode of the present embodiment is not inserted on the cathode side, the cathode 21 is in the frame of the cathode chamber 20. The cathode 21 preferably has a nickel substrate and a catalyst layer that covers the nickel substrate. Examples of catalyst bed components include elements such as Ru, C, Si, P, S, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Rh, Pd , Ag, Cd, In, Sn, Ta, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho , Er, Tm, Yb and Lu, as well as oxides and hydroxides of these metals. Examples of the method for forming the catalyst layer include electrodeposition, alloy electrodeposition, dispersion / composite electrodeposition, CVD, FOPP, pyrolysis, and sputtering. These methods can be used in combination. The catalyst bed can have multiple layers and multiple elements as needed. The cathode 21 can be subjected to a reduction treatment, if necessary. Nickel, nickel alloys and nickel-plated iron or stainless steel can be used as the substrate for the cathode 21.

As for the shape, any of a perforated metal sheet, a nonwoven fabric, a porous metal, an expanded metal sheet, an electrospinning metal porous foil, a so-called woven metal mesh formed by interlacing of thin metal filaments, and the like can be used.

[0291] (Cathode supply conductor)

When the electrode for electrolysis of the present embodiment is inserted on the cathode side, a cathode supply conductor 21 is provided in the frame of the cathode chamber 20. The cathode supply conductor 21 may be coated with a catalyst component. The catalyst component can be a component that is initially used as a cathode and is stored. Examples of catalyst bed components include elements such as Ru, C, Si, P, S, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Rh, Pd , Ag, Cd, In, Sn, Ta, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho , Er, Tm, Yb and Lu, as well as oxides and hydroxides of these metals. Examples of the method for forming the catalyst layer include electrodeposition, alloy electrodeposition, dispersion / composite electrodeposition, CVD, FOPP, pyrolysis, and sputtering. These methods can be used in combination. The catalyst bed can have multiple layers and multiple elements as needed. Alternatively, nickel, nickel alloys, and nickel-plated iron or stainless steel without catalytic coating can be used. Nickel, nickel alloys and nickel-plated iron or stainless steel can be used as the substrate for the cathode supply conductor 21.

As for the shape, any of a perforated metal sheet, a nonwoven fabric, a porous metal, an expanded metal sheet, an electrospinning metal porous foil, a so-called woven metal mesh formed by interlacing of thin metal filaments, and the like can be used.

[0292] (Reverse Current Absorbing Layer)

As the material for the layer that absorbs the reverse current, a material that is less noble in terms of the redox potential than the redox potential of the element for the aforementioned catalyst layer of the cathode can be selected. Examples include nickel and iron.

[0293] (Down conductor)

The cathode chamber 20 preferably contains a current collector 23. The current collector 23 improves the efficiency of current extraction. In the present embodiment, the collector 23 is a porous plate and is preferably disposed substantially parallel to the surface of the cathode 21.

[0294] The collector 23 preferably contains an electrically conductive metal such as nickel, iron, copper, silver and titanium. The current collector 23 can be a mixture, alloy or complex oxide of these metals. The collector 23 may be of any shape as long as the shape allows the collector to function and may be in the form of a plate or mesh.

[0295] (Metallic elastic body)

By placing the metal elastic body 22 between the current collector 23 and the cathode 21, each cathode 21 of a plurality of electrolytic cells 1 connected in series is pressed against the ion exchange membrane 2 to shorten the distance between each anode 11 and each cathode 21. Thus, it is possible to reduce the voltage applied to the entire plurality of electrolytic cells connected in series. cells 1. Reducing voltage helps to reduce power consumption. When the metal resilient body 22 is placed, the pressing pressure created by the metal resilient body 22 allows the electrolysis electrode to stably maintain its position in place when the laminated article containing the electrolysis electrode of the present embodiment is placed in the electrolytic cell.

[0296] As the metal resilient body 22, spring members such as coil and coil springs and damping mats can be used. As the metal elastic body 22, an element can be appropriately applied in consideration of mechanical stress due to pressure on the ion exchange membrane and the like. The metal resilient body 22 may be located on the surface of the collector 23 on the side of the cathode chamber 20, or may be provided on the surface of the partition wall on the side of the anode chamber 10. The two chambers are usually separated so that the cathode chamber 20 becomes smaller than the anode chamber 10. Thus In terms of frame strength and the like, the metal resilient body 22 is preferably placed between the collector 34 and the cathode 21 in the cathode chamber 20. The metal resilient body 22 preferably contains an electrically conductive metal such as nickel, iron, copper, silver and titanium.

[0297] (Holder)

The cathode chamber 20 preferably comprises a holder 24 which electrically connects the collector 23 to the baffle 30. This can achieve an efficient current flow.

[0298] The holder 24 preferably contains an electrically conductive metal such as nickel, iron, copper, silver, and titanium. The holder 24 can be of any shape as long as the holder can support the collector 23 and can be in the form of a rod, plate, or mesh. The holder 24 is in the form of a plate, for example. A plurality of holders 24 are disposed between the baffle 30 and the down conductor 23. The plurality of holders 24 are aligned so that their surfaces are parallel to each other. The holders 24 are located substantially perpendicular to the baffle 30 and the down conductor 23.

[0299] (Anode side seal and cathode side seal)

The anode side seal is preferably located on the surface of the frame constituting the anode chamber 10. The cathode side seal is preferably positioned on the surface of the frame constituting the cathode compartment 20. The electrolytic cells are interconnected such that the anode side seal in one electrolytic cell and the cathode side seal an ion exchange membrane 2 is laid on an adjacent electrolytic cell (see Figures 26 and 27). These seals can create airtightness at the junctions when a plurality of electrolytic cells 1 are connected in series through an ion exchange membrane 2.

[0300] The seals form a seal between the ion exchange membrane and the electrolytic cells. Specific examples of seals include picture frame-like rubber sheets in the center of which an opening is formed. The seals must be resistant to corrosive electrolyte solutions or generated gas and be functional for a long period of time. Thus, with regard to chemical resistance and hardness, vulcanized products and peroxide-crosslinked products of ethylene-propylene-diene rubber (EPDM-rubber) and ethylene-propylene rubber (EPM-rubber) are usually used as seals. Alternatively, if necessary, seals can be used in which the area in contact with the liquid (the area in contact with the liquid) is coated with a fluorine resin such as polytetrafluoroethylene (PTFE) and copolymers of tetrafluoroethylene and perfluoroalkyl vinyl ethers (PFA). These seals may in each case have an opening that does not impede the flow of the electrolyte solution, and the shape of the opening is not particularly limited. For example, a seal in the form of a picture frame is attached by means of an adhesive or the like along the peripheral edge of each opening of the anode chamber frame constituting the anode compartment 10 or the cathode compartment frame constituting the cathode compartment 20. Then, for example, in the case where two electrolytic cells 1 are connected through ion exchange membrane 2 (see Figure 27), each electrolytic cell 1 to which a seal is attached must be sealed by means of an ion exchange membrane 2. This seal can prevent electrolyte solution, alkali metal hydroxide, chlorine gas, hydrogen gas from escaping from the electrolytic cells 1 and the like formed by electrolysis.

[0301] (Ion exchange membrane 2)

The ion exchange membrane 2 is as described in the above section on the ion exchange membrane.

[0302] (Water electrolysis)

The electrolytic cell of the present embodiment as an electrolysis cell in the case of water electrolysis has a configuration in which an ion exchange membrane in the electrolysis cell for use in the case of the above conventional salt electrolysis is replaced with a microporous membrane. The supplied raw material, which is water, is different from the material for the electrolytic cell in the case of the above-mentioned conventional salt electrolysis. As for other components, parts similar to those of the electrolysis cell in the case of conventional salt electrolysis can also be used in a water electrolysis cell. Since chlorine gas is generated in the anode chamber in conventional salt electrolysis, titanium is used as the anode chamber material, but in the case of water electrolysis, only oxygen gas is emitted in the anode chamber. Thus, a material identical to that of the cathode chamber can be used. Nickel is one example of this. A catalytic coating for generating oxygen is suitable for coating the anode. Examples of the catalytic coating include metals, oxides and hydroxides of platinum group metals and metals from the transition metal group. For example, elements such as platinum, iridium, palladium, ruthenium, nickel, cobalt, and iron can be used.

[0303] (Application of a laminated product)

The laminated article of the present embodiment can improve the working efficiency during the renewal of the electrode in the electrolytic cell, and in addition, can provide excellent electrolysis performance even after the renewal, as mentioned above. In other words, the laminated product of the present embodiment can be usefully used as a laminated product for replacing an element in an electrolytic cell. The laminate used in such applications is more specifically referred to as a "membrane-electrode assembly".

[0304] (Packing)

The laminate of the present embodiment is preferably transported or similarly handled by enclosing it in a packaging material. That is, the package of the present embodiment contains the laminate of the present embodiment and a packaging material in which the laminate is packed. The packaging of the present embodiment configured as described above can prevent dirt adhesion and damage that may occur during transportation or the like of the laminated article of the present embodiment. When the laminated article is used to replace cell elements, it is particularly preferably transported or similarly handled in the package of the present embodiment. As the packaging material of the present embodiment, which is not particularly limited, a variety of known packaging materials can be used. Alternatively, the package of the present embodiment may be manufactured, for example, by a method comprising packaging the laminate of the present embodiment in a blank packaging material followed by sealing or the like, although not limited thereto.

[0305] <Third embodiment>

Here, a third embodiment of the present invention will be described in detail with reference to Figures 43-62.

[0306] [Laminated Product]

The laminated article according to the third embodiment (hereinafter in the section <Third Embodiment> simply referred to as the “present embodiment”) comprises a membrane and an electrolysis electrode secured by at least one “membrane” surface area (hereinafter simply called “attachment area”), and the amount of this area on the surface of the membrane is more than 0% and less than 93%. The laminated article of the present embodiment, configured as described above, can improve the operating efficiency during the renewal of the electrode in the electrolytic cell, and in addition, can exhibit excellent electrolysis performance even after the renewal.

That is, according to the layered article of the present embodiment, when the electrode is renewed, the electrode can be renewed as simple as renewing the membrane without complicated work such as disassembling an existing electrode attached to the electrolytic cell, and thereby noticeably improve the working efficiency.

In addition, according to the layered article of the present embodiment, it is possible to maintain the electrolysis productivity with the existing electrolytic cell compared to the performance of the new electrode, or improve the electrolysis productivity. Thus, an electrode attached to an existing electrolytic cell and serving as anode and / or cathode should only act as a supply conductor. Thus, appreciable reduction or elimination of the catalytic coating can also be possible. The supply conductor here means a worn-out electrode (i.e., an existing electrode), an electrode not having a catalytic coating, and the like.

[0307] [Electrolysis Electrode]

The electrolysis electrode of the present embodiment is not particularly limited as long as the electrode is an electrode used for electrolysis, and preferably has a surface area opposite the membrane of the electrolysis electrode (corresponding to the following conductive surface area S2) of 0.01 m ² or more ... "Opposite to the membrane" means the surface of the surfaces of the electrolysis electrode on which the membrane is located. That is, the surface opposite the membrane in the electrolysis electrode may also be a surface that is adjacent to the membrane surface. When the surface area opposite the membrane in the electrolysis electrode is 0.01 m ² or more, sufficient productivity can be achieved, and especially when electrolysis is carried out on an industrial scale, sufficient productivity can be obtained. Thus, from the viewpoint of achieving sufficient productivity and practicality of the laminated article used for renewing an electrolytic cell, the surface area opposite the membrane in the electrolysis electrode is more preferably 0.1 m ² or more, further preferably 1 m ² or more. The area can be measured, for example, in the manner described in the Examples.

[0308] The electrode for electrolysis of the present embodiment has a force applied per unit mass · unit area, preferably 1.6 N / (mg · cm ² ) or less, more preferably less than 1.6 N / (mg · cm ² ) , further preferably less than 1.5 N / (mg cm ² ), even more preferably 1.2 N / (mg cm ² ) or less, even more preferably 1.20 N / (mg cm ² ) or less with from the point of view of providing good workability and good adhesion to a membrane such as an ion exchange membrane and a microporous membrane, with a supply conductor (a worn electrode and an electrode not having a catalytic coating) and the like. The applied force is even more preferably 1.1 N / (mg cm ² ) or less, further more preferably 1.10 N / (mg cm ² ) or less, even more preferably 1.0 N / (mg cm ²⁾ ) or less, even more preferably 1.00 N / (mg · cm ² ) or less.

From the viewpoint of further improving the electrolysis productivity, the force is preferably more than 0.005 N / (mg cm ² ), more preferably 0.08 N / (mg cm ² ) or more, further preferably 0.1 N / (mg cm ² ) or more, even more preferably 0.14 N / (mg · cm ² ) or more. Even more preferably, the force is 0.2 N / (mg · cm ² ) or more from the viewpoint of further facilitating the handling of a large size (eg, 1.5 mx 2.5 m).

The above-described applied force may be within the above-described range by appropriately adjusting, for example, the below-described open porosity ratio, electrode thickness, arithmetic mean of surface roughness, and the like. For example, more specifically, a higher open porosity ratio results in a lower applied force, and a lower open porosity ratio results in a higher applied force.

The mass per unit area is preferably 48 mg / cm ² or less, more preferably 30 mg / cm ² or less, even more preferably 20 mg / cm ² or less from the viewpoint of providing good processability and good adhesion to the membrane, such as an ion exchange membrane and a microporous membrane, with a worn electrode, with a feed conductor not having a catalytic coating, and economy, and moreover, is preferably 15 mg / cm ² or less, for general reasons including manufacturability, adhesion strength and economy. The lower limit is not particularly limited, but is, for example, on the order of 1 mg / cm ² .

The above-described mass per unit area may be within the above-described range, for example, by appropriately adjusting the below-described open porosity ratio, electrode thickness, and the like. More specifically, for example, when the thickness is constant, a higher open porosity ratio results in a decrease in mass per unit area, and a lower open porosity ratio results in a higher mass per unit area.

[0309] The applied force can be measured by methods (i) or (ii) described below. The value obtained by measuring method (i) (also called "applied force (1)") and the value obtained by measuring method (ii) (also called "applied force (2)") may be the same or different, and each of the values is preferably less than 1.5 N / (mg · cm ² ).

[0310] [Method (i)]

Nickel plate blasted with alumina 320 grit (thickness 1.2 mm, square with side 200 mm), ion-exchange membrane obtained by applying particles of inorganic material and a binder to both surfaces of a perfluorocarbon polymer into which an ion-exchange group is introduced (square 170 mm side) and a sample electrolysis electrode (130 mm square) are layered in that order. Thereafter, the laminated product is sufficiently immersed in clean water, and excess water deposited on the surface of the laminated product is removed to obtain a sample for measurement. The arithmetic mean (Ra) of the surface roughness of a nickel plate after blasting is 0.5 to 0.8 μm. A specific method for calculating the arithmetic mean (Ra) of the surface roughness is described in the Examples.

Under the condition of temperature 23 ± 2 ° C and relative humidity 30 ± 5%, only the electrode sample in this measurement sample is lifted in the vertical direction at a speed of 10 mm / minute using a tensile compression machine and the load is measured when the electrode sample is lifted 10 mm vertically. This measurement is repeated three times and the average is calculated.

This average value is divided by the area of the overlapping area of the electrode sample and the ion exchange membrane and by the mass of the ion exchange membrane in the area of overlapping with the electrode sample to calculate the applied force per unit mass · unit area (1) (N / (mg · cm ² )).

[0311] The applied force per unit mass · unit area (1) obtained by method (i) is preferably 1.6 N / (mg · cm ² ) or less, more preferably less than 1.6 N / (mg · cm ² ), further preferably less than 1.5 N / (mg cm ² ), even more preferably 1.2 N / (mg cm ² ) or less, even more preferably 1.20 N / (mg cm ² ) or less in terms of providing good processability and good adhesion to a membrane such as an ion exchange membrane or a microporous membrane, a worn electrode, and an uncatalyzed supply conductor. The applied force is even more preferably 1.1 N / (mg cm ² ) or less, further more preferably 1.10 N / (mg cm ² ) or less, particularly preferably 1.0 N / (mg cm ² ) or less, particularly preferably 1.00 N / (mg · cm ² ) or less. The force is preferably more than 0.005 N / (mg cm ² ), more preferably 0.08 N / (mg cm ² ) or more, further preferably 0.1 N / (mg cm ² ) or more in view of further improvement productivity of electrolysis, and, moreover, more preferably 0.14 N / (mg cm ² ), even more preferably 0.2 N / (mg cm ² ) or more, from the standpoint of further facilitating the handling of large size (for example, size 1.5m × 2.5m).

[0312] [Method (ii)]

A nickel plate blasted with alumina 320 grit (thickness 1.2 mm, square with a side of 200 mm, a nickel plate similar to the plate in the above method (i)), and an electrode sample (square with a side of 130 mm) is layered in this okay. Thereafter, the laminated product is sufficiently immersed in clean water, and excess water deposited on the surface of the laminated product is removed to obtain a sample for measurement. Under the condition of temperature 23 ± 2 ° C and relative humidity 30 ± 5%, only the electrode sample in this measurement sample is lifted in the vertical direction at a speed of 10 mm / minute using a tensile compression machine and the load is measured when the electrode sample is lifted 10 mm vertically. This measurement is repeated three times and the average is calculated.

This average value is divided by the area of the overlapping area of the electrode sample and the nickel plate and by the weight of the electrode sample in the overlapping area with the nickel plate to calculate the applied force per unit mass · unit area (2) (N / (mg · cm ² )).

[0313] The applied force per unit mass · unit area (2) obtained by method (ii) is preferably 1.6 N / (mg · cm ² ) or less, more preferably less than 1.6 N / (mg · cm ² ), further preferably less than 1.5 N / (mg cm ² ), even more preferably 1.2 N / (mg cm ² ) or less, even more preferably 1.20 N / (mg cm ² ) or less in terms of providing good processability and good adhesion to a membrane such as an ion exchange membrane or a microporous membrane, a worn electrode, and an uncatalyzed supply conductor. The applied force is even more preferably 1.1 N / (mg cm ² ) or less, further more preferably 1.10 N / (mg cm ² ) or less, particularly preferably 1.0 N / (mg cm ² ) or less, particularly preferably 1.00 N / (mg · cm ² ) or less. In addition, the force is preferably more than 0.005 N / (mg cm ² ), more preferably 0.08 N / (mg cm ² ) or more, further preferably 0.1 N / (mg cm ² ) or more from the point in terms of further improving the productivity of electrolysis, and, moreover, more preferably is 0.14 N / (mg cm ² ) from the position of further facilitating the handling of a large size (for example, size 1.5 m × 2.5 m) ...

[0314] The electrolysis electrode of the present embodiment preferably comprises an electrolysis electrode support and a catalyst layer. The thickness of the electrode substrate for electrolysis (measured thickness) is, but is not particularly limited, preferably 300 μm or less, more preferably 205 μm or less, even more preferably 155 μm or less, further preferably 135 μm or less, even more preferably 125 μm or less, even more preferably 120 μm or less, even more preferably 100 μm or less from the point of view of ensuring good processability, achieving good adhesion to a membrane such as an ion exchange membrane or a microporous membrane, with a worn electrode (supply conductor) and an electrode ( feed conductor), which does not have a catalytic coating, being suitable for roll-up and satisfactory folding into folds and facilitates loading and unloading at a large size (for example, size 1.5 mx 2.5 m), and, in addition, still more preferably 50 µm or less in terms of processability and economy. The lower limit is not particularly limited, but is, for example, 1 µm, preferably 5 µm, more preferably 15 µm.

[0315] The proportion measured by the following method (2) on the electrode for electrolysis of the present embodiment is not particularly limited, but is preferably 90% or more, more preferably 92% or more from the viewpoint of ensuring good processability and achieving good adhesion strength with membrane, such as an ion exchange membrane or a microporous membrane, with a worn electrode (supply conductor) and an electrode (supply conductor) not having a catalytic coating, and additionally preferably 95% or more from the point of view of further facilitating handling when large size (for example , size 1.5 m × 2.5 m). The upper limit value is 100%.

[Method (2)]

An ion exchange membrane (170 mm square) and an electrode sample (130 mm square) are layered in this order. The laminated product is placed on the curved surface of a polyethylene pipe (outer diameter: 280 mm) so that the electrode sample in this laminated product is positioned outside at a temperature of 23 ± 2 ° C and a relative humidity of 30 ± 5%, the laminated product and the pipe are sufficiently immersed into clean water, remove the excess water deposited on the surface of the laminated product and the pipe, and then, one minute after this removal, measure the fraction (%) of the area of the area in which the ion-exchange membrane (square with a side of 170 mm) is in close contact with electrode.

[0316] The proportion measured by the following method (3) on the electrode for electrolysis of the present embodiment is not particularly limited, but is preferably 75% or more, more preferably 80% or more from the viewpoint of ensuring good workability, achieving good adhesion strength with membrane, such as an ion exchange membrane or microporous membrane, with a worn electrode (supply conductor) and an electrode (supply conductor) not having a catalytic coating, and for proper roll-winding and satisfactory creasing, and is additionally preferably 90% or more from the point of view of additional facilitation of loading and unloading at a large size (for example, size 1.5 m × 2.5 m). The upper limit value is 100%.

[Method (3)]

An ion exchange membrane (170 mm square) and an electrode sample (130 mm square) are layered in this order. The laminated product is placed on the curved surface of a polyethylene pipe (outer diameter: 145 mm) so that the electrode sample in this laminated product is positioned externally at a temperature of 23 ± 2 ° C and a relative humidity of 30 ± 5%, the laminated product and the pipe are sufficiently immersed into clean water, remove the excess water deposited on the surface of the laminated product and the pipe, and then, one minute after this removal, measure the fraction (%) of the area of the area in which the ion-exchange membrane (square with a side of 170 mm) is in close contact with electrode.

[0317] The electrode for electrolysis of the present embodiment has a porous structure and an open porosity ratio or void ratio of 5 to 90% or less in terms of ensuring good processability, achieving good adhesion to a membrane such as an ion exchange membrane or a microporous membrane, with a worn electrode (supply conductor) and an electrode (supply conductor) not having a catalytic coating, and preventing the accumulation of gas evolved during electrolysis, although not specifically limited thereto. The open porosity ratio is more preferably 10 to 80% or less, more preferably 20 to 75%.

The Open Porosity Ratio represents the fraction of lumen areas per unit volume. The calculation method may differ depending on whether sub-micron-sized gaps are considered or only visible gaps are considered. In the present embodiment, the volume V was calculated from the values of the measured thickness, the width and the length of the electrode, and in addition, the weight W was measured to thereby calculate the open porosity coefficient A by the following formula.

A = (1– (W / (V × ρ)) × 100

ρ is the density of the electrode material (g / cm ³ ). For example, the ρ of nickel is 8.908 g / cm ³ and the ρ of titanium is 4.506 g / cm ³ . The open porosity ratio is appropriately controlled by changing the area of perforated metal per unit area in the case of a perforated metal sheet, changing the values of SW (short diameter), LW (long diameter), and feed in the case of expanded metal sheet, changing the linear dimensions of the diameter of the metal fiber, and sieve numbers in the case of a mesh, a change in the photoresist pattern used in the case of electrospinning, a change in the diameter of the metal fiber and the density of the fiber in the case of a nonwoven fabric, a change in the mold for forming cavities in the case of a porous metal, or the like.

[0318] Hereinafter, one aspect of the electrolysis electrode of the present embodiment will be described.

The electrolysis electrode of the present embodiment preferably comprises an electrolysis electrode support and a catalyst layer. The catalyst bed can be composed of multiple layers, as shown below, or can have a single layer configuration.

As shown in FIG. 43, the electrolysis electrode 100 of the present embodiment includes an electrolysis electrode substrate 10 and a pair of first layers 20 that cover both surfaces of the electrolysis electrode substrate 10. The first layers 20 preferably cover the entire electrode substrate 10 for electrolysis. Apparently, this coating increases the catalytic activity and durability of the electrode. One first layer 20 can only be laminated to one surface of the electrolysis electrode substrate 10.

In addition, as shown in Figure 43, the surfaces of the first layers 20 may be coated with the second layers 30. The first layers 20 are preferably covered with the second layers 30 in their entirety. Alternatively, one second layer 30 may be laminated to only one surface of the first layer 20.

[0319] (Electrode support for electrolysis)

As the electrode substrate 10 for electrolysis, for example, nickel, nickel alloys, stainless steel, and, in addition, valve metals, including titanium, can be used, although not limited thereto. Substrate 10 preferably contains at least one element selected from nickel (Ni) and titanium (Ti).

When stainless steel is used in an aqueous alkali solution of high concentration, iron and chromium are washed out and the electrical conductivity is in the order of one tenth that of nickel. In view of the above, as the electrode substrate for electrolysis, a substrate containing nickel (Ni) is preferable.

Alternatively, when the electrode substrate 10 for electrolysis is used in a brine with a high concentration close to saturation, in an atmosphere in which chlorine gas is generated, the material of the electrode substrate 10 is also preferably titanium having high corrosion resistance.

The shape of the electrode substrate 10 for electrolysis is not particularly limited, and a shape suitable for this purpose can be selected. As the mold, any of a perforated metal sheet, a nonwoven fabric, a porous metal, an expanded metal sheet, an electrospinning metal porous foil, a so-called woven metal mesh, and the like can be used. Of these, perforated metal sheet or expanded metal sheet is preferable. Electrospinning is a method of producing a thin metal foil having a precisely shaped pattern using photolithography and electrodeposition in combination. It is a method involving patterning a substrate with a photoresist and electrodeposition of a portion not protected by the resist to form a metal thin film.

With regard to the shape of the electrode support for electrolysis, a suitable specification depends on the distance between the anode and the cathode in the electrolysis cell. In the case where the distance between the anode and the cathode is finite, the shape of an expanded metal sheet or a perforated metal sheet can be used, and in the case of a so-called zero-gap electrolyzer in which the ion exchange membrane is in contact with the electrode, a formed interlacing of fine metal filaments woven metal mesh, wire mesh, porous metal, metal nonwoven fabric, expanded metal sheet, perforated metal sheet, metal porous foil, and the like, although not limited thereto.

Examples of the electrode substrate 10 for electrolysis include metal porous foil, wire mesh, metal nonwoven fabric, perforated metal sheet, expanded metal sheet, and porous metal.

As the plate material before being processed to form a perforated metal sheet or expanded metal sheet, rolled plate materials and electrolytic foils are preferred. The electrolytic foil is preferably subjected to a further electrodeposition treatment using the same element as its base material as a further treatment to thereby form roughness on one or both of its surfaces.

The thickness of the electrolysis electrode substrate 10 as mentioned above is preferably 300 µm or less, more preferably 205 µm or less, further preferably 155 µm or less, even more preferably 135 µm or less, even more preferably 125 µm or less, even more preferably 120 µm or less, even more preferably 100 µm or less, and further even more preferably 50 µm or less in terms of processability and economy. The lower limit is not particularly limited, but is, for example, 1 µm, preferably 5 µm, more preferably 15 µm.

[0320] In the electrolysis electrode substrate, residual stress during processing is preferably relieved by annealing the electrolysis electrode substrate in an oxidizing atmosphere. It is preferable to form roughness using a steel grid, an alumina grid or the like on the surface of the electrode substrate for electrolysis, followed by acid treatment to increase its surface area in order to improve adhesion to the catalyst layer that is coated on the surface. Alternatively, it is preferable to carry out the electrodeposition treatment using the same element as the substrate to increase the surface area.

[0321] To bring the first layer 20 into intimate contact with the surface of the electrolysis electrode substrate 10, the electrolysis electrode substrate 10 is preferably subjected to a surface area increase treatment. Examples of surface area enhancing treatments include chopped wire blasting, steel grating, alumina grating or the like, acidizing using sulfuric acid or hydrochloric acid, and electrodeposition using the same element as in the substrate. The arithmetic mean (Ra) of the surface roughness on the surface of the substrate is not particularly limited, but is preferably 0.05 µm to 50 µm, more preferably 0.1 to 10 µm, even more preferably 0.1 to 8 µm.

[0322] Next, a case will be described where the electrolysis electrode of the present embodiment is used as an anode for conventional salt electrolysis.

(First layer)

In Figure 43, the first layer 20 contains at least one of ruthenium oxides, iridium oxides and titanium oxides as a catalyst layer. Examples of ruthenium oxide include RuO ₂ . Examples of iridium oxide include IrO ₂ . Examples of titanium oxide include TiO ₂ . The first layer 20 preferably contains two oxides: ruthenium oxide and titanium oxide, or three oxides: ruthenium oxide, iridium oxide and titanium oxide. This makes the first layer 20 more stable and further improves the adhesion to the second layer 30.

[0323] When the first layer 20 contains two oxides: ruthenium oxide and titanium oxide, the first layer 20 preferably contains from 1 to 9 moles, more preferably from 1 to 4 moles of titanium oxide, based on 1 mole of ruthenium oxide contained in the first layer 20 With the compositional ratio of the two oxides in this range, the electrolysis electrode 100 exhibits excellent resistance.

[0324] When the first layer 20 contains three oxides: ruthenium oxide, iridium oxide and titanium oxide, the first layer 20 preferably contains 0.2 to 3 moles, more preferably 0.3 to 2.5 moles of iridium oxide per 1 mol of ruthenium oxide contained in the first layer 20. The first layer 20 preferably contains from 0.3 to 8 moles, more preferably from 1 to 7 moles of titanium oxide, based on 1 mole of ruthenium oxide contained in the first layer 20. With a compositional ratio of three oxides in this range, the electrolysis electrode 100 exhibits excellent resistance.

[0325] When the first layer 20 contains at least two of ruthenium oxide, iridium oxide and titanium oxide, these oxides preferably form a solid solution. The formation of a solid solution of the oxides allows the electrolysis electrode 100 to exhibit excellent resistance.

[0326] In addition to the above-described compositions, oxides of various compositions can be used, provided that at least one of ruthenium oxide, iridium oxide, and titanium oxide is contained. For example, an oxide coating called DSA (R), which contains ruthenium, iridium, tantalum, niobium, titanium, tin, cobalt, manganese, platinum, and the like, can be used as the first layer 20.

[0327] The first layer 20 need not be a single layer and may include multiple layers. For example, the first layer 20 may include a three-oxide layer and a two-oxide layer. The thickness of the first layer 20 is preferably 0.05 to 10 µm, more preferably 0.1 to 8 µm.

[0328] (Second layer)

The second layer 30 preferably contains ruthenium and titanium. This makes it possible to further reduce the electrical overvoltage of chlorine immediately after electrolysis.

[0329] The second layer 30 preferably contains palladium oxide, a solid solution of palladium and platinum oxide, or an alloy of palladium and platinum. This makes it possible to further reduce the electrical overvoltage of chlorine immediately after electrolysis.

[0330] The thicker second layer 30 can maintain the electrolysis performance for a long period of time, but from the standpoint of economy, the thickness is preferably 0.05 to 3 µm.

[0331] Next, a situation will be described where the electrolysis electrode of the present embodiment is used as a cathode for conventional salt electrolysis.

(First layer)

Examples of the components of the first layer 20 as a catalyst layer include elements such as C, Si, P, S, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, In, Sn, Ta, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu, as well as metal oxides and hydroxides.

The first layer 20 may or may not contain at least one of platinum group metals, platinum group metal oxides, platinum group metal hydroxides, and platinum group metal containing alloys.

When the first layer 20 contains at least one of platinum group metals, platinum group metal oxides, platinum group metal hydroxides and alloys containing a platinum group metal, platinum group metals, platinum group metal oxides, platinum group metal hydroxides, and platinum metal containing alloys the groups preferably contain at least one platinum group metal from platinum, palladium, rhodium, ruthenium and iridium.

The platinum group metal is preferably platinum.

As the oxide of the platinum group metal, ruthenium oxide is preferably contained.

As the hydroxide of the platinum group metal, ruthenium hydroxide is preferably contained.

As an alloy of platinum group metals, an alloy of platinum with nickel, iron and cobalt is preferably included.

In addition, if necessary, an oxide or hydroxide of a lanthanide element is preferably contained as the second component. This allows the electrolysis electrode 100 to exhibit excellent resistance.

As the oxide or hydroxide of the lanthanide element, preferably at least one selected from lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium and dysprosium is contained.

In addition, if necessary, a transition metal oxide or hydroxide is preferably contained as the third component.

The addition of the third component allows the electrolysis electrode 100 to exhibit superior resistance and lower electrolysis voltage.

Examples of a preferred combination include only ruthenium, ruthenium + nickel, ruthenium + cerium, ruthenium + lanthanum, ruthenium + lanthanum + platinum, ruthenium + lanthanum + palladium, ruthenium + praseodymium, ruthenium + praseodymium + platinum, ruthenium + praseodymium + platinum + palladium, ruthenium + neodymium, ruthenium + neodymium + platinum, ruthenium + neodymium + manganese, ruthenium + neodymium + iron, ruthenium + neodymium + cobalt, ruthenium + neodymium + zinc, ruthenium + neodymium + gallium, ruthenium + neodymium + sulfur, ruthenium + neodymium + lead , ruthenium + neodymium + nickel, ruthenium + neodymium + copper, ruthenium + samarium, ruthenium + samarium + manganese, ruthenium + samarium + iron, ruthenium + samarium + cobalt, ruthenium + samarium + zinc, ruthenium + samarium + gallium, ruthenium + samarium + sulfur, ruthenium + samarium + lead, ruthenium + samarium + nickel, platinum + cerium, platinum + palladium + cerium, platinum + palladium + lanthanum + cerium, platinum + iridium, platinum + palladium, platinum + iridium + palladium, platinum + nickel + palladium, platinum + nickel + ruthenium, platinum and nickel alloys, platinum and cobalt alloys and platinum and iron alloys.

When platinum-group metals, platinum-group metal oxides, platinum-group metal hydroxides, and platinum-group metal-containing alloys are not contained, the main component of the catalyst is preferably the element nickel.

Preferably, at least one of nickel metal, nickel oxides and hydroxides is contained.

A transition metal can be added as a second component. As the second added component, at least one of titanium, tin, molybdenum, cobalt, manganese, iron, sulfur, zinc, copper and carbon is preferably contained.

Examples of a preferred combination include nickel + tin, nickel + titanium, nickel + molybdenum, and nickel + cobalt.

If necessary, an intermediate layer may be disposed between the first layer 20 and the electrolysis electrode substrate 10. By placing the intermediate layer, the resistance of the electrolysis electrode 100 can be improved.

Preferred as the intermediate layer are those which have an affinity for both the first layer 20 and the electrode substrate 10 for electrolysis. As the intermediate layer, preferred are nickel oxides, platinum group metals, platinum group metal oxides and platinum group metal hydroxides. The intermediate layer can be formed by applying and firing a solution containing the component that forms the intermediate layer. Alternatively, a surface oxide layer can also be formed by subjecting the substrate to heat treatment at a temperature of 300 to 600 ° C. in an air atmosphere. In addition, this layer can be formed by a known method such as a thermal spraying method and an ionic deposition method.

[0332] (Second layer)

Examples of the components of the first layer 30 as a catalyst layer include elements such as C, Si, P, S, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, In, Sn, Ta, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu, as well as metal oxides and hydroxides.

The first layer 30 may or may not contain at least one of platinum group metals, platinum group metal oxides, platinum group metal hydroxides, and platinum group metal containing alloys. Examples of a preferred combination of elements contained in the second layer include those listed for the first layer. The combination of the first layer and the second layer can be a combination in which the compositions are the same and the compositional ratios are different, or it can be a combination of different compositions.

With regard to the thickness of the catalyst layer, the total thickness of the formed catalyst layer and the intermediate layer is preferably 0.01 µm to 20 µm. With a thickness of 0.01 µm or more, the catalyst layer can sufficiently serve as a catalyst. With a thickness of 20 µm or less, a strong catalyst layer can be formed that is unlikely to separate from the support. The thickness is more preferably 0.05 µm to 15 µm. The thickness is more preferably 0.1 to 10 µm. Even more preferably, the thickness is 0.2 to 8 µm.

[0333] The thickness of the electrode, that is, the combined thickness of the electrolysis electrode support and the catalyst layer, is preferably 315 µm or less, more preferably 220 µm or less, further preferably 170 µm or less, even more preferably 150 µm or less, particularly preferably 145 µm or less, even more preferably 140 µm or less, even more preferably 138 µm or less, further even more preferably 135 µm or less, with respect to the workability of the electrode. A thickness of 135 µm or less can provide good workability. In addition, for similar reasons as above, the thickness is preferably 130 µm or less, more preferably less than 130 µm, even more preferably 115 µm or less, further more preferably 65 µm or less. The lower limit is not particularly limited, but is preferably 1 µm or more, more preferably 5 µm or more for practical reasons, more preferably 20 µm or more. The thickness of the electrode can be determined by measuring with a digital thickness gauge (from Mitutoyo Corporation, minimum scale 0.001 mm). The thickness of the substrate of the electrolysis electrode can be measured in the same manner as in the case of the electrode. The thickness of the catalyst layer can be determined by subtracting the thickness of the electrolysis electrode support from the thickness of the electrode.

[0334] In the present embodiment, the electrode for electrolysis preferably contains at least one catalyst component selected from the group consisting of Ru, Rh, Pd, Ir, Pt, Au, Ti, V, Cr, Mn, Fe, Co, Ni , Cu, Zn, Y, Zr, Nb, Mo, Ag, Ta, W, Re, Os, Al, In, Sn, Sb, Ga, Ge, B, C, N, O, Si, P, S, La , Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb and Dy, from the standpoint of achieving sufficient electrolysis performance.

[0335] In the present embodiment, from the considerations that the electrode for electrolysis of the present embodiment, if it is an electrode having a wide elastic range, can provide better workability and has better adhesion to a membrane such as an ion exchange membrane or a microporous membrane, with a worn electrode, with a supply conductor not having a catalytic coating, and the like, the thickness of the electrode for electrolysis is preferably 315 μm or less, more preferably 220 μm or less, even more preferably 170 μm or less, even more preferably 150 μm or less, particularly preferably 145 µm or less, even more preferably 140 µm or less, further still more preferably 138 µm or less, even more preferably 135 µm or less. A thickness of 135 µm or less can provide good workability. In addition, for reasons similar to the above, the thickness is preferably 130 µm or less, more preferably less than 130 µm, further preferably 115 µm or less, even more preferably 65 µm or less. The lower limit is not particularly limited, but is preferably 1 µm or more, more preferably 5 µm or more for practical reasons, more preferably 20 µm or more. In the present embodiment, “having a wide elastic range” means that when the electrolysis electrode is wound to form a winding, it is unlikely that winding-induced warping will occur after being released from the wound state. The thickness of the electrolysis electrode when the below-mentioned catalyst layer is provided refers to the total thickness of both the electrolysis electrode support and the catalyst layer.

[0336] (Method for Manufacturing Electrolysis Electrode)

Next, one embodiment of a method for manufacturing an electrode 100 for electrolysis will be described in detail.

In the present embodiment, the electrolysis electrode 100 can be obtained by forming a first layer 20, preferably a second layer 30 on the electrolysis electrode substrate by a method such as firing a coating film in an oxygen atmosphere (pyrolysis) or ion deposition, electrodeposition, or thermal sputtering. The production method of the present embodiment as mentioned above can achieve high formation productivity of the electrolysis electrode 100. More specifically, a catalyst layer is formed on the electrode support for electrolysis by an application step in which a coating liquid containing the catalyst is applied, a drying step in which the coating liquid is dried, and a pyrolysis step in which pyrolysis is performed. Pyrolysis here means that a metal salt, which is to be a precursor, decomposes by heating into a metal or metal oxide and a gaseous substance. The decomposition product depends on the nature of the metal used, the type of salt and the atmosphere in which the pyrolysis is carried out, and many metals tend to form oxides in an oxidizing atmosphere. In the industrial process for making an electrode, pyrolysis is usually performed in air and in many cases a metal oxide or metal hydroxide is formed.

[0337] (Formation of the first layer of the anode)

(Application stage)

The first layer 20 is obtained by applying a solution in which at least one metal salt of ruthenium, iridium and titanium (first coating liquid) is dissolved on the electrode substrate for electrolysis, and then pyrolysis (calcining) the coating liquid in the presence of oxygen. The content of ruthenium, iridium and titanium in the first cover liquid is substantially equivalent to that in the first layer 20.

[0338] The metal salts can be chlorides, nitrates, sulfates, metal alkoxides, and any other form. The solvent of the first coating liquid can be selected depending on the type of metal salt, and water and alcohols such as butanol can be used. As the solvent, water or a mixed solvent of water and alcohol is preferred. The total metal concentration in the first coating liquid in which the metal salts are dissolved is not particularly limited, but is preferably in the range of 10 to 150 g / L in consideration of the thickness of the coating film formed by a single application.

[0339] Examples of a method used as a method for applying a first coating liquid to an electrolysis electrode substrate 10 include a method for dipping the electrolysis electrode substrate 10 into a first coating liquid, a method for applying a first coating liquid with a brush, a rolling method using a sponge roller impregnated the first coating liquid, and an electrostatic coating method in which the electrode substrate 10 for electrolysis and the first coating liquid are charged with opposite charges and sputtering is performed. Among them, a rolling method or an electrostatic coating method is preferable, which has excellent production performance on an industrial scale.

[0340] (Drying Step and Pyrolysis Step)

After applying the first coating liquid to the electrode substrate 100 for electrolysis, it is dried at a temperature of 10 to 90 ° C and subjected to pyrolysis in a roasting furnace heated to a temperature of 350 to 650 ° C. Between drying and pyrolysis, if necessary, a pre-firing can be performed at a temperature of 100 to 350 ° C. The temperature for drying, pre-firing and pyrolysis is appropriately selected depending on the composition and type of solvent of the first coating liquid. A longer period of pyrolysis time in each step is preferable, but from the viewpoint of productivity of producing an electrode, 3 to 60 minutes, more preferably 5 to 20 minutes are preferable.

[0341] The cycle of the above-described application, drying and pyrolysis is repeated to form a coating (first layer 20) to a predetermined thickness. After the first layer 20 is formed and then further post-baked for an extended period of time as required, this can further increase the stability of the first layer 20.

[0342] (Formation of the second layer)

The second layer 30, which is formed if necessary, is obtained, for example, by applying a solution containing a palladium compound and a platinum compound or a solution containing a ruthenium compound and a titanium compound (second coating liquid) on the first layer 20, and then the coating liquid is subjected to pyrolysis in presence of oxygen.

[0343] (Formation of the first cathode layer by pyrolysis method)

(Application stage)

The first layer 20 is obtained by applying a solution in which metal salts in various combinations are dissolved (first coating liquid) on an electrode substrate for electrolysis, and then pyrolysis (calcining) the coating liquid in the presence of oxygen. The metal content in the first coating liquid is substantially equivalent to that in the first layer 20.

[0344] The metal salts can be chlorides, nitrates, sulfates, metal alkoxides, and any other form. The solvent of the first coating liquid can be selected depending on the type of metal salt, and water and alcohols such as butanol can be used. As the solvent, water or a mixed solvent of water and alcohol is preferred. The total metal concentration in the first coating liquid in which the metal salts are dissolved is not particularly limited, but is preferably in the range of 10 to 150 g / L in consideration of the thickness of the coating film formed by a single application.

[0345] Examples of the method used as the method for applying the first coating liquid to the electrolysis electrode substrate 10 include a method of dipping the electrolysis electrode substrate 10 into the first coating liquid, a method for applying the first coating liquid with a brush, a rolling method using a sponge roller impregnated the first coating liquid, and an electrostatic coating method in which the electrode substrate 10 for electrolysis and the first coating liquid are charged with opposite charges and sputtering is performed. Among them, a rolling method or an electrostatic coating method is preferable, which has excellent production performance on an industrial scale.

[0346] (Drying Step and Pyrolysis Step)

After applying the first coating liquid to the electrode substrate 100 for electrolysis, it is dried at a temperature of 10 to 90 ° C and subjected to pyrolysis in a roasting furnace heated to a temperature of 350 to 650 ° C. Between drying and pyrolysis, if necessary, a pre-firing can be performed at a temperature of 100 to 350 ° C. The temperature for drying, pre-firing and pyrolysis is appropriately selected depending on the composition and type of solvent of the first coating liquid. A longer period of pyrolysis time in each step is preferable, but from the viewpoint of productivity of producing an electrode, 3 to 60 minutes, more preferably 5 to 20 minutes are preferable.

[0347] The cycle of the above-described application, drying and pyrolysis is repeated to form a coating (first layer 20) to a predetermined thickness. After the first layer 20 is formed and then further post-baked for an extended period of time as required, this can further increase the stability of the first layer 20.

[0348] (Interlayer Formation)

The intermediate layer, which is formed, if necessary, is obtained, for example, by applying a solution containing a palladium compound or a platinum compound (second coating liquid) to a substrate, and then pyrolysis of the coating liquid in the presence of oxygen. Alternatively, the nickel oxide intermediate layer can be formed on the surface of the substrate by heating the substrate only, without applying a solution thereto.

[0349] (Formation of the first cathode layer by ion deposition)

The first layer 20 can also be formed by ion deposition.

The example comprises a method in which a substrate is fixed in a chamber and a ruthenium metal target is irradiated with an electron beam. Particles of vaporized metallic ruthenium are positively charged in the plasma in the chamber, deposited on a negatively charged substrate. The plasma atmosphere is argon and / or oxygen and ruthenium is deposited on the substrate as ruthenium oxide.

[0350] (Formation of the first cathode layer by electrodeposition)

The first layer 20 can also be formed by electrodeposition.

As an example, when the substrate is used as a cathode and is subjected to plating in an electrolyte solution containing nickel and tin, an electrolytic plating of a nickel-tin alloy can be formed.

[0351] (Formation of the first layer of the cathode by thermal spraying)

The first layer 20 can also be formed by thermal spraying.

By way of example, nickel oxide particles sprayed by plasma onto a substrate may form a catalyst bed in which nickel metal and nickel oxide are mixed.

[0352] The electrolysis electrode of the present embodiment may be combined with a membrane such as an ion exchange membrane or a microporous membrane and used. Thus, the laminated article of the present embodiment can be applied as a membrane-integrated electrode. Then the work of replacing the cathode and anode is eliminated when renewing the electrode and the work efficiency is noticeably improved.

An electrode combined with a membrane, such as an ion exchange membrane and a microporous membrane, can make electrolysis performance comparable to or better than that with a new electrode.

[0353] Next, the ion exchange membrane will be described in detail.

[Ion exchange membrane]

The ion exchange membrane is not particularly limited as long as the membrane can be laminated with an electrolysis electrode and a variety of ion exchange membranes can be used. In the present embodiment, an ion exchange membrane is preferably used which has a membrane body containing a hydrocarbon polymer or a fluorine-containing polymer having an ion exchange group and a coating layer provided on at least one surface of the membrane body. It is preferable that the coating layer contains particles of inorganic material and a binder, and the specific surface area of the coating layer is 0.1 to 10 m ² / g. In an ion exchange membrane having such a structure, the effect of gas evolved during electrolysis on the electrolysis performance is small, and stable electrolysis performance can be demonstrated.

The above-described fluoropolymer ion exchange membrane into which an ion exchange group has been introduced contains one of either a sulfonic acid layer having an ion exchange group derived from a sulfo group (a group represented by —SO ₃ ^- , hereinafter also referred to as a “sulfonic acid group”), or a carboxylic acid layer having an ion exchange group derived from a carboxyl group (a group represented as —CO ₂ ^- , hereinafter also referred to as a “carboxylic acid group”). From the point of view of strength and dimensional stability, it is preferable to additionally include core reinforcing materials.

The inorganic material particles and the binder will be described in detail below in the coating layer description section.

[0354] Figure 44 illustrates a schematic sectional view showing one embodiment of an ion exchange membrane. The ion exchange membrane 1 has a membrane body 10 containing a hydrocarbon polymer or a fluorine-containing polymer having an ion exchange group, and coating layers 11a and 11b formed on both surfaces of the membrane body 10.

[0355] In the ion exchange membrane 1, the membrane body 10 includes a sulfonic acid layer 3 having an ion exchange group derived from a sulfo group (a group represented by —SO ₃ ^- , hereinafter also referred to as a “sulfonic acid group”), and a carboxylic acid layer 2, having an ion exchange group derived from a carboxyl group (a group represented by —CO ₂ ^- , hereinafter also referred to as a “carboxylic acid group”), and core reinforcing materials 4 that increase strength and dimensional stability. An ion exchange membrane 1 including a sulfonic acid layer 3 and a carboxylic acid layer 2 is suitably used as an anion exchange membrane.

[0356] The ion exchange membrane may include one of a sulfonic acid layer and a carboxylic acid layer. The ion exchange membrane does not need to be reinforced with core reinforcing materials, and the arrangement of the core reinforcing materials is not limited to the example in FIG. 44.

[0357] (Membrane Body)

First, the membrane body 10 constituting the ion exchange membrane 1 will be described.

The body 10 of the membrane should be such that its function is to provide selective permeation of cations, and contains a hydrocarbon polymer or a fluorine-containing polymer having an ion exchange group. Its configuration and material are not particularly limited, and preferable ones can be appropriately selected.

[0358] The hydrocarbon polymer or fluorine-containing polymer having an ion exchange group in the membrane body 10 can be obtained from a hydrocarbon polymer or fluorine-containing polymer having an ion exchange group precursor capable of forming an ion exchange group by hydrolysis or the like. More specifically, for example, after a polymer containing a fluorinated hydrocarbon backbone having a side chain that is converted to an ion exchange group by hydrolysis or the like (ion exchange group precursor) is used to obtain a precursor of the membrane body 10, and melt-processable ( below in some cases referred to as "fluorine-containing polymer (s)"), the membrane body 10 can be obtained by converting a precursor of an ion exchange group into an ion exchange group.

[0359] The fluorine-containing polymer (s) can be obtained, for example, by copolymerizing at least one monomer selected from the next first group and at least one monomer selected from the next second group and / or the next third group. The fluorine-containing polymer (s) can also be obtained by homopolymerizing one monomer selected from any of the next first group, the next second group, and the next third group.

[0360] Examples of monomers of the first group include vinyl fluoride compounds. Examples of vinyl fluoride compounds include vinyl fluoride, tetrafluoroethylene, hexafluoropropylene, vinylidene fluoride, trifluoroethylene, chlorotrifluoroethylene, and perfluoroalkyl vinyl ethers. In particular, when an ion exchange membrane is used as a membrane for alkaline electrolysis, the vinyl fluoride compound is preferably a perfluorinated monomer, and a perfluorinated monomer selected from the group consisting of tetrafluoroethylene, hexafluoropropylene and perfluoroalkyl vinyl ethers is preferred.

[0361] Examples of monomers of the second group include vinyl compounds having a functional group convertible to an ion exchange group of the carboxylic acid type (carboxylic acid group). Examples of vinyl compounds having a functional group convertible to a carboxylic acid ion exchange group include monomers represented by the formula CF ₂ = CF (OCF ₂ CYF) _s –O (CZF) _t –COOR, in which s is an integer from 0 to 2, t is an integer from 1 to 12, each of Y and Z is independently F or CF ₃ and R is a lower alkyl group (a lower alkyl group is an alkyl group having, for example, 1 to 3 carbon atoms).

[0362] Among them, preferred are compounds represented by the formula CF ₂ = CF (OCF ₂ CYF) _n —O (CF ₂ ) _m —COOR, in which n represents an integer from 0 to 2, m represents an integer from 1 to 4, Y is F or CF ₃ and R is CH ₃ , C ₂ H ₅ or C ₃ H ₇ .

[0363] When an ion exchange membrane is used as a cation exchange membrane for alkaline electrolysis, the perfluoro compound is preferably used at least as a monomer, but the alkyl group (see R values above) of the ester group is lost from the polymer during hydrolysis, and therefore the alkyl group (R) is not must necessarily be a perfluoroalkyl group in which all hydrogen atoms are replaced by fluorine atoms.

[0364] Of the above monomers, the following monomers are more preferred as monomers of the second group:

CF ₂ = CFOCF ₂ –CF (CF ₃ ) OCF ₂ COOCH ₃ ,

CF ₂ = CFOCF ₂ CF (CF ₃ ) O (CF ₂ ) ₂ COOCH ₃ ,

CF ₂ = CF [OCF ₂ –CF (CF ₃ )] ₂ O (CF ₂ ) ₂ COOCH ₃ ,

CF ₂ = CFOCF ₂ CF (CF ₃ ) O (CF ₂ ) ₃ COOCH ₃ ,

CF ₂ = CFO (CF ₂ ) ₂ COOCH ₃ and

CF ₂ = CFO (CF ₂ ) ₃ COOCH ₃ .

[0365] Examples of monomers of the third group include vinyl compounds having a functional group convertible to an ion exchange group of the sulfone type (sulfonic acid group). As vinyl compounds having a functional group convertible to a sulfonic acid ion exchange group, for example, monomers represented by the formula CF ₂ = CFO — X — CF ₂ —SO ₂ F in which X is a perfluoroalkylene group are preferred. Specific examples include the following monomers:

CF ₂ = CFOCF ₂ CF ₂ SO ₂ F,

CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₂ F,

CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ CF ₂ SO ₂ F,

CF ₂ = CF (CF ₂ ) ₂ SO ₂ F,

CF ₂ = CFO [CF ₂ CF (CF ₃ ) O] ₂ CF ₂ CF ₂ SO ₂ F and

CF ₂ = CFOCF ₂ CF (CF ₂ OCF ₃ ) OCF ₂ CF ₂ SO ₂ F.

[0366] Among them, CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ CF ₂ SO ₂ F and CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₂ F are more preferable.

[0367] The copolymer obtained from these monomers can be formed by a polymerization process designed for homopolymerization and copolymerization of ethylene fluoride, in particular by a general polymerization process used for tetrafluoroethylene. For example, in a method using a non-aqueous medium, the polymerization reaction can be carried out in the presence of a free radical polymerization initiator such as a perfluorocarbon peroxide or an azo compound, under conditions of a temperature of 0 to 200 ° C and a pressure of 0.1 to 20 MPa, using an inert solvent, such as a perfluorocarbon or a chlorofluorocarbon.

[0368] In the above copolymerization, the type of combination of the above monomers and their proportions are not particularly limited and are determined depending on the type and amount of functional groups that it is desirable to introduce into the resulting fluorine-containing polymer. For example, when a fluorine-containing polymer containing only a carboxylic acid group is produced, at least one polymer must be selected from each of the above-described first group and second group and copolymerized. In addition, when a fluorine-containing polymer containing only a sulfonic acid group is prepared, at least one polymer must be selected from each of the first group and the third group, and copolymerized. In addition, when a fluorine-containing polymer having a carboxylic acid group and a sulfonic acid group is produced, at least one monomer must be selected from each of the above-described first group, second group and third group and copolymerized. In this case, the target fluorine-containing polymer can also be obtained by separately forming a copolymer including monomers of the above-described first group and second group, and a copolymer including monomers of the above-described first group and third group, and then mixing these copolymers. The composition of the mixture of monomers is not particularly limited, and when the number of functional groups per structural unit of the polymer increases, the proportion of monomers selected from the above-described second group and third group must increase.

[0369] The total ion exchange capacity of the fluorine-containing copolymer is not particularly limited, but is preferably 0.5 to 2.0 mg⋅eq / g, more preferably 0.6 to 1.5 mg⋅eq / g. The total ion exchange capacity here refers to the equivalent of the exchange group per unit weight of dry resin and can be measured by neutralization titration or the like.

[0370] In the membrane body 10 of the ion exchange membrane 1, a sulfonic acid layer 3 containing a fluorine-containing polymer having a sulfonic acid group and a carboxylic acid layer 2 containing a fluorine-containing polymer having a carboxylic acid group are laminated. By providing the membrane body 10 having such a layer configuration, the selective permeability to cations such as sodium ions can be further improved.

[0371] The ion exchange membrane 1 is disposed in the electrolytic cell so that generally the sulfonic acid layer 3 is on the anode side of the cell and the carboxylic acid layer 2 is on the cathode side of the cell.

[0372] The sulfonic acid layer 3 is preferably composed of a material having a low electrical resistance and is thicker than the carboxylic acid layer 2 in terms of membrane strength. The thickness of the sulfonic acid layer 3 is preferably 2 to 25 times, more preferably 3 to 15 times the thickness of the carboxylic acid layer 2.

[0373] The carboxylic acid layer 2 preferably has high anion exclusion characteristics even if it is thin. The anion exclusion characteristics herein refer to the characteristic of hindering the incorporation and penetration of anions into or through the ion exchange membrane 1. In order to improve the anion exclusion characteristics, it is effective to place a carboxylic acid layer having a low ion exchange capacity compared to the sulfonic acid layer.

[0374] As the fluorine-containing polymer for use in the sulfonic acid layer 3, a polymer obtained using CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₂ F as the third group monomer is preferable.

[0375] As the fluorine-containing polymer for use in the carboxylic acid layer 2, a polymer obtained using CF ₂ = CFOCF ₂ CF (CF ₂ ) O (CF ₂ ) ₂ COOCH _{3 is} preferred as the monomer of the second group.

[0376]

(Coating layer)

The ion exchange membrane preferably has a coating layer on at least one surface of the membrane body. As shown in Figure 44, in the ion exchange membrane 1, coating layers 11a and 11b are formed on both surfaces of the membrane body 10.

The coating layers contain particles of inorganic material and a binder.

[0377] The average particle size of the inorganic material is preferably 0.90 µm or more. When the average particle size of the inorganic material is 0.90 µm or more, impurity resistance is greatly improved in addition to gas attachment. That is, by increasing the average particle size of the inorganic material as well as keeping the above-mentioned specific surface area, a particularly noticeable effect can be achieved. Uneven particles of inorganic material are preferred insofar as the above average particle size and specific surface area are satisfied. Melting inorganic material particles and raw ore milling inorganic material particles can be used. Preferably, particles of inorganic material obtained by milling raw ore are used.

[0378] The average particle size of the inorganic material may be 2 µm or less. When the average particle size of the inorganic material is 2 µm or less, damage to the membrane by the inorganic material can be prevented. The average particle size of the inorganic material is more preferably 0.90 to 1.2 µm.

[0379] Here, the average particle size can be measured by a particle size analyzer ("SALD2200", manufactured by SHIMADZU CORPORATION).

[0380] The particles of inorganic material preferably have irregular shapes. Such shapes further improve the resistance to impurities. The particles of inorganic material preferably have a wide particle size distribution.

[0381] The particles of inorganic material preferably contain at least one inorganic material selected from the group consisting of oxides of Group IV elements of the Periodic Table, nitrides of Group IV elements of the Periodic Table, and carbides of Group IV elements of the Periodic Table. From the standpoint of resistance, zirconium oxide particles are more preferable.

[0382] The inorganic material particles are preferably inorganic material particles obtained by grinding raw ore from inorganic material particles, or inorganic material particles in the form of spherical particles having a uniform diameter obtained by refining a raw ore melt from inorganic material particles.

[0383] Examples of means for grinding raw ore include, but are not specifically limited to, ball mills, bead mills, colloid mills, cone grinders, disc mills, runners, grain mills, hammer mills, granulators, vertical shaft impact crushers (VSI ), leather mills (Wiley mills), roller mills and jet mills. After grinding, the particles are preferably washed. As a washing method, the particles are preferably treated with an acid. This treatment can reduce the amount of impurities such as iron adhered to the surface of the inorganic material particles.

[0384] The coating layer preferably contains a binder. The binder is the component that forms the coating layers by retaining particles of inorganic material on the surface of the ion exchange membrane. The binder preferably contains a fluorine-containing polymer from the standpoint of resistance to electrolyte solution and electrolysis products.

[0385] As a binder, a fluorine-containing polymer having a carboxylic acid group or a sulfonic acid group is more preferable in terms of resistance to electrolyte solution and electrolysis products and adhesion strength to the surface of the ion exchange membrane. When the coating layer is provided on a layer containing a fluorine-containing polymer having a sulfonic acid group (sulfonic acid layer), the fluorine-containing polymer having a sulfonic acid group is even more preferably used as a binder for the coating layer. Alternatively, when the coating layer is provided on a layer containing a fluorine-containing polymer having a carboxylic acid group (carboxylic acid layer), a fluorine-containing polymer having a carboxylic acid group is more preferably used as a binder for the coating layer.

[0386] The content of the particles of inorganic material in the coating layer is preferably 40 to 90% by mass, more preferably 50 to 90% by mass. The content of the binder is preferably 10 to 60% by mass, more preferably 10 to 50% by mass.

[0387] The distribution density of the coating layer in the ion exchange membrane is preferably 0.05 to 2 mg per cm ² . When the ion exchange membrane has ridges (roughness) on its surface, the distribution density of the coating layer is preferably 0.5 to 2 mg per cm ² .

[0388] As a method for manufacturing the coating layer, which is not particularly limited, a known method can be applied. An example is a method comprising applying by spray or the like a coating liquid obtained by dispersing particles of an inorganic material in a solution containing a binder.

[0389] (Core Reinforcement Materials)

The ion exchange membrane preferably has core reinforcing materials disposed within the membrane body.

[0390] Reinforcing materials of the core are elements that increase the strength and dimensional stability of the ion exchange membrane. By placing the reinforcing materials of the core within the body of the membrane, it is possible, in particular, to control the expansion and contraction of the ion exchange membrane in the desired range. Such an ion exchange membrane does not expand or contract more than necessary during electrolysis and the like, and can maintain excellent dimensional stability for a long time.

[0391] The configuration of the core reinforcing materials is not particularly limited, and, for example, the core reinforcing materials may be formed by woven yarns called reinforcing yarns. Reinforcing yarns herein refer to yarns that constitute the constituent core reinforcing materials, can provide the desired dimensional stability and mechanical strength to the ion exchange membrane, and can be stably present in the ion exchange membrane. By using core reinforcing materials obtained by weaving such reinforcing yarns, better dimensional stability and mechanical strength can be imparted to the ion exchange membrane.

[0392] The material of the reinforcing materials of the core and the reinforcing yarns used therefor is not particularly limited, but is preferably a material resistant to acids, alkalis, etc., and a fiber including a fluorine-containing polymer is preferable since long-term heat resistance and chemical resistance are required. ...

[0393] Examples of the fluoropolymer used in core reinforcing materials include polytetrafluoroethylene (PTFE), copolymers of tetrafluoroethylene and perfluoroalkyl vinyl ether (PFA), copolymers of tetrafluoroethylene and ethylene (ETFE), copolymers of tetrafluoroethylene copolymers and tetrafluoroethylene copolymers PVDF). Among them, fibers including polytetrafluoroethylene are preferably used in terms of heat resistance and chemical resistance.

[0394] The diameter of the reinforcing yarns used for the core reinforcing materials is not particularly limited, but is preferably 20 to 300 denier, more preferably 50 to 250 denier. The weave density (web density per unit length) is preferably 5 to 50 / inch. The shape of the core reinforcing materials is not particularly limited, for example, woven fabric, non-woven fabric and knitted fabric are used, but preferably in the form of woven fabric. The thickness of the woven fabric used is preferably 30 to 250 µm, more preferably 30 to 150 µm.

[0395] As the woven fabric or knitted fabric, monofilaments, multifilaments or yarns thereof, twisted yarns with dangling yarns or the like can be used, and various types of weaving methods can be used such as plain weave, leno weave, knitted weave, cord weave and crinkled chintz (seersucker).

[0396] The braiding and placement of the core reinforcing materials in the membrane body are not particularly limited, and the preferred placement can be appropriately provided in consideration of the size and shape of the ion exchange membrane, physical properties desired for the ion exchange membrane, environmental conditions in use, and the like.

[0397] For example, the core reinforcing materials may be placed along a predetermined direction of the membrane body, but from a dimensional stability point of view, it is preferable that the core reinforcing materials are placed along a predetermined first direction and other core reinforcing materials are placed along a predetermined second direction along essentially perpendicular to the first direction. By placing multiple core reinforcement materials substantially orthogonal within the membrane body, better dimensional stability and mechanical strength in many directions can be imparted. For example, a configuration is preferable in which core reinforcing materials disposed along the longitudinal direction (warp yarns) and core reinforcing materials disposed along the transverse direction (weft yarns) are woven on the surface side of the membrane body. A more preferred configuration is in the form of a plain weave, made and woven by allowing the warp and weft yarns to pass alternately above and below each other, a leno weave in which two base strands are woven into the weft strands in a twist, a matting weave made and woven by inserting the same number of weft yarns or the like into two or more parallel warp yarns, or the like, from the standpoint of dimensional stability, mechanical strength and ease of manufacture.

[0398] It is particularly preferred that the core reinforcing materials are disposed along both directions MD (longitudinal direction) and TD (transverse direction) of the ion exchange membrane. In other words, the core reinforcing materials are preferably plain weave in MD and TD. Here, MD means the direction in which the membrane body and various core materials (for example, reinforcing core materials, reinforcing yarns and consumable yarns described later) move in the later described stage of obtaining the ion exchange membrane (flow direction), and TD means a direction substantially perpendicular to MD ... The yarns weaved along the MD are called MD yarns, and the yarns weaved along the TD are called TD yarns. Typically, the ion exchange membrane used for electrolysis is rectangular, and in many cases, the longitudinal direction is MD and the width direction is TD. By weaving reinforcing core materials that are MD yarns and reinforcing core materials that are TD yarns, better dimensional stability and mechanical strength can be achieved in many directions.

[0399] The placement range of the core reinforcing materials is not particularly limited, and the preferred placement can be appropriately provided in consideration of the physical properties desired for the ion exchange membrane, the environmental conditions in use, and the like.

[0400] The opening ratio of the core reinforcing materials is not particularly limited, but is preferably 30% or more, more preferably 50% or more and 90% or less. The opening ratio is preferably 30% or more in terms of the electrochemical characteristics of the ion exchange membrane, and preferably 90% or less in terms of the mechanical strength of the ion exchange membrane.

[0401] The opening ratio of the reinforcing materials of the core herein refers to the ratio (B / A) of the total surface area (B) through which substances such as ions (electrolyte solution and the cations (eg sodium ions) contained therein) can pass to area (A) of any one surface of the body of the ion-exchange membrane. The total surface area (B) through which substances such as ions can pass may refer to the total areas of regions in which cations, electrolyte solution and the like are not retained in the ion exchange membrane by the reinforcing materials of the core and the like contained in the ion exchange membrane. membrane.

[0402] Figure 45 illustrates a schematic view for explaining the relative opening of the core reinforcing materials constituting the ion exchange membrane. Figure 45, in which a portion of the ion exchange membrane is shown enlarged, shows only the configuration of the core reinforcement materials 21 and 22 in these regions, without showing other elements.

[0403] By subtracting the total area (C) of the core reinforcing materials from the area of the area surrounded by the core reinforcing materials 21 along the longitudinal direction and the core reinforcing materials 22 located along the transverse direction, the area including the area (A) of the core reinforcing materials can the total area (B) of the regions through which substances such as ions can pass in the area (A) of the above-described region can be obtained. That is, the relative aperture can be determined by the following formula (I):

Relative aperture = (B) / (A) = ((A) - (C)) / (A) (I)

[0404] Among the reinforcing materials of the core, a film textile thread or highly oriented monofilaments including PTFE is particularly preferred in terms of chemical resistance and heat resistance. More specifically, more preferred are plain weave core reinforcing materials that use 50 to 300 denier film textile yarns made by cutting a PTFE-containing high tenacity porous sheet into ribbon-shaped pieces, or comprising highly oriented PTFE monofilaments of 50 to 300 denier sizes. 300 denier, and which have a weave density of 10 to 50 threads or monofilaments per inch and have a thickness in the range of 50 to 100 microns. The opening ratio of the ion exchange membrane including such core reinforcing materials is more preferably 60% or more.

[0405] Examples of the shape of the reinforcing yarns include round yarns and film yarns.

[0406] (Through Holes)

The ion exchange membrane preferably has through holes within the membrane body.

[0407] Through holes refer to holes that can form channels for ions generated during electrolysis and for an electrolyte solution. Through holes, which are tubular holes formed within the membrane body, are formed by dissolving the core consumables (or yarns) described below. The shape, diameter, or the like of the through holes can be controlled by selecting the shape or diameter of the core consumables (yarn consumables).

[0408] The formation of through holes within the ion exchange membrane can provide mobility of the electrolyte solution during electrolysis. The shape of the through holes is not particularly limited, but may be the shape of the core consumable materials used to form the through holes according to the production method described below.

[0409] The through holes are preferably formed to alternately extend on the anode side (sulfonic acid layer side) and cathode side (carboxylic acid layer side) of the core reinforcing materials. With this arrangement, in the region in which the through holes are formed on the cathode side of the core reinforcing materials, ions (eg sodium ions) supplied by the electrolyte solution filling the through holes can also flow to the cathode side of the core reinforcing materials. As a result, the flow of cations is not interrupted, and thus an additional reduction in the electrical resistance of the ion-exchange membrane is possible.

[0410] The through holes may be formed along only one predetermined direction of the membrane body constituting the ion exchange membrane, but are preferably formed along both the longitudinal direction and the transverse direction of the membrane body in view of exhibiting more stable electrolysis characteristics.

[0411] [Manufacturing Method]

A suitable example of a method for manufacturing an ion exchange membrane includes a method comprising the following steps (1) to (6):

Step (1): a step of producing a fluorine-containing polymer having an ion exchange group or an ion exchange group precursor capable of forming an ion exchange group by hydrolysis,

Step (2): a step of weaving at least a plurality of core reinforcing materials, if necessary, and consumable yarns that dissolve in acid or alkali and form through holes, to obtain a reinforcing material in which the consumable yarns are interposed between the core reinforcing materials, being adjacent to each other,

Step (3): a step of converting into a film the above fluorine-containing polymer having an ion exchange group or an ion exchange group precursor capable of forming an ion exchange group by hydrolysis,

Step (4): the step of introducing the above reinforcing materials, if necessary, into the above film to obtain a membrane body, inside which the reinforcing materials are placed,

Stage (5): stage of hydrolysis of the membrane body obtained in stage (4) (stage of hydrolysis) and

Step (6): The step of creating a coating layer on the membrane body obtained in step (5) (application step).

[0412] Next, each of the steps will be described in detail.

[0413] Step (1): a step of obtaining a fluoropolymer

In step (1), the monomeric starting materials described above in groups one to three are used to prepare the fluoropolymer. To regulate the ion-exchange capacity of the fluorine-containing polymer, the composition of the mixture of the starting monomer materials must be controlled during the production of the fluorine-containing polymer forming the said layers.

[0414] Step (2): the step of obtaining reinforcing materials

The reinforcing material is a woven fabric obtained by weaving reinforcing yarns or the like. The reinforcing material is embedded in the membrane to thereby form core reinforcing materials. When an ion-exchange membrane with through holes is formed, consumable yarns are additionally woven into the reinforcing material. The amount of consumable yarns contained in this case is preferably 10 to 80% by mass, more preferably 30 to 70% by mass, based on the total reinforcing material. The weaving of the consumable yarns can also prevent slippage of the yarns of the core reinforcing materials.

[0415] Viscose, polyethylene terephthalate (PET), cellulose, polyamide and the like are used as the consumable yarns that are dissolved in the membrane production step or in the electrolysis environment. Also preferred are monofilaments or multifilaments having a thickness of 20 to 50 denier and including polyvinyl alcohol and the like.

[0416] In step (2), the aperture ratio, the placement of the through holes, and the like can be controlled by adjusting the placement of the core reinforcing materials and the yarns consumed.

[0417] Step (3): Film forming step

In step (3), the fluoropolymer obtained in step (1) is formed into a film using an extruder. The film may have a single layer configuration, a two layer configuration of a sulfonic acid layer and a carboxylic acid layer as mentioned above, or a multilayer configuration of three or more layers.

[0418] Examples of the film forming method include the following:

a method in which a fluorine-containing polymer having a carboxylic acid group and a fluorine-containing polymer having a sulfonic acid group are separately formed into films; and

a method in which a fluorine-containing polymer having a carboxylic acid group and a fluorine-containing polymer having a sulfonic acid group are coextruded to form a composite film.

[0419] The number of each film can be more than one. Co-extrusion of different films is preferred because of their contribution to the increase in bond strength at the interface.

[0420] Step (4): the step of obtaining the membrane body

In step (4), the reinforcing material obtained in step (2) is embedded in the film obtained in step (3) to form a membrane body containing the reinforcing material.

[0421] Preferred examples of a method for forming a membrane body include (i) a method in which a fluorine-containing polymer having a precursor of a carboxylic acid group (e.g., a carboxylate functional group) (hereinafter referred to as a first layer) disposed on the cathode side and a fluorine-containing polymer having a precursor of a sulfonic acid group (for example, a sulfonyl fluoride functional group) (hereinafter, including this layer is called the second layer), is formed into a film by the method of coextrusion, and, if necessary, using a heat source and a vacuum source, a reinforcing material and a composite film from the second layer / the first layer is laminated in this order on a breathable heat-resistant release paper on a flat plate or drum having numerous pores on their surface, and combined at a temperature at which each polymer melts while at the same time evacuating air from under each of the layers by means of reduced pressure ; and (ii) a method in which, in addition to the composite film of the second layer / first layer, a fluorine-containing polymer having a precursor of a sulfonic acid group is separately preformed into a film (third layer), and optionally using a heat source and a source vacuum, the third layer film, the core reinforcing materials and the composite film from the second layer / first layer are laminated in this order on a breathable heat-resistant release paper on a flat plate or drum having multiple pores on their surface and combined at a temperature at which each polymer is melted while pumping air out from under each of the layers by means of reduced pressure.

[0422] Co-extrusion of the first and second layer here helps to increase the bond strength at the interface.

[0423] The method of combining under reduced pressure is characterized by making the third layer on the reinforcing material thicker than in the press-applied method. In addition, since the reinforcing material is fixed to the inner surface of the membrane body, the method provides sufficient retention of the mechanical strength of the ion exchange membrane.

[0424] Embodiments of the layering methods described herein are exemplary, and coextrusion may be performed after the preferred layering configuration (eg, a combination of layers) is appropriately selected in consideration of the desired membrane body layer configurations and physical properties, and the like.

[0425] In order to further improve the electrical characteristics of the ion exchange membrane, it is also possible to additionally place a fourth layer comprising a fluorine-containing polymer having both a precursor of a carboxylic acid group and a precursor of a sulfonic acid group between the first layer and the second layer, or the use of a fourth layer comprising a fluorine-containing polymer having both a precursor of a carboxylic acid group and a precursor of a sulfonic acid group instead of the second layer.

[0426] The method for forming the fourth layer may be a method in which a fluorine-containing polymer having a precursor of a carboxylic acid group and a fluorine-containing polymer having a precursor of a sulfonic acid group are separately prepared and then mixed, or it may be a method in which a monomer is copolymerized having a precursor of a carboxylic acid group; and a monomer having a sulfonic acid precursor.

[0427] When the fourth layer is used as a component of the ion exchange membrane, a coextruded film of the first layer and the fourth layer is formed, in addition, the third layer and the second layer are separately formed into films, and the laminating can be performed in the above manner. Alternatively, three layers of the first layer / fourth layer / second layer can be coextruded simultaneously to form a film.

[0428] In this case, the direction in which the extruded film flows out is MD. As mentioned above, it is possible to form a membrane body containing a fluorine-containing polymer having an ion exchange group on the reinforcing material.

[0429] In addition, the ion exchange membrane preferably has protrusions constituted by a fluoropolymer having a sulfonic acid group, that is, protrusions on the side of the surface constituted by the sulfonic acid layer. As a method for forming such protrusions, which is not particularly limited, a known method including forming protrusions on a resin surface can also be applied. A specific example of the method is a method for embossing the surface of a membrane body. For example, the aforementioned protrusions can be formed using the pre-embossed release paper when the above composite film, reinforcing material, and the like are combined. In the case where the protrusions are formed by embossing, the height and density of the protrusions can be controlled by the shape of the transferred relief (the shape of the release paper).

[0430] (5) Hydrolysis step

At step (5), the stage of hydrolysis of the membrane body obtained at stage (4) is performed to convert the precursor of the ion-exchange group into an ion-exchange group (stage of hydrolysis).

[0431] In step (5), it is also possible to dissolve holes in the membrane body by dissolving and removing consumable yarns introduced into the membrane body by the action of an acid or alkali. The consumable yarns can remain in the through holes without being completely dissolved and removed. The consumable yarns remaining in the through holes can be dissolved and removed by the electrolyte solution when the ion exchange membrane is subjected to electrolysis.

[0432] The consumable yarn is dissolved in acid or alkali at the stage of obtaining the ion exchange membrane or in the electrolysis environment. The consumable yarns are washed out, thereby forming the through-holes at the appropriate locations.

[0433] Step (5) may be performed by immersing the membrane body obtained in step (4) in a hydrolysis solution containing an acid or alkali. An example of a hydrolysis solution that can be used is a mixed solution containing KOH and dimethyl sulfoxide (DMSO).

[0434] The mixed solution preferably contains KOH at normal concentration from 2.5 to 4.0 and DMSO from 25 to 35% by weight.

[0435] The temperature in the hydrolysis is preferably 70 to 100 ° C. The higher the temperature, the greater the apparent thickness can be. The temperature is more preferably 75 to 100 ° C.

[0436] The duration of the hydrolysis is preferably 10 to 120 minutes. The longer the hydrolysis takes, the greater the apparent thickness can be. The duration of the hydrolysis is preferably 20 to 120 minutes.

[0437] The step of forming the through holes by washing out the sacrificial yarns will now be described in more detail. Figures 46 (a) and (b) are schematic views for explaining a method of forming vias in an ion exchange membrane.

[0438] Figures 46 (a) and (b) show reinforcing yarns 52, sacrificial yarns 504a and through holes 504 formed only by sacrificial yarns 504a, without illustrating other features such as a membrane body.

[0439] First, the reinforcing yarns 52, which are to constitute the core reinforcing materials in the ion exchange membrane, and the consumable yarns 504a for forming the through holes 504 in the ion exchange membrane are used as interlaced reinforcing materials. Then, in step (5), the consumable yarns 504a are washed out to form the through holes 504.

[0440] The above method is simple because the method of interlacing the reinforcing yarns 52 and the consumable yarns 504a can be adjusted depending on the placement order of the core reinforcing materials and the through holes in the body of the ion exchange membrane.

[0441] Figure 46 (a) illustrates an example of a plain weave reinforcing material in which the reinforcing yarns 52 and the sacrificial yarns 504a are interlaced in both the longitudinal direction and the transverse direction in the paper, and, if necessary, the order of placement of the reinforcing yarns 52 and the sacrificial yarn 504a in the reinforcing material can be changed.

[0442] (6) Application Step

In step (6), a coating layer can be formed by preparing a coating liquid containing particles of inorganic material obtained by grinding raw ore or melting raw ore and a binder, applying a coating liquid to the surface of the ion exchange membrane obtained in step (5), and drying the coating liquids.

[0443] A preferred binder is a binder obtained by hydrolysis of a fluorine-containing polymer having an ion exchange group precursor with an aqueous solution containing dimethyl sulfoxide (DMSO) and potassium hydroxide (KOH), and then immersing the polymer in hydrochloric acid to replace the counter ion of the ion exchange group with H ⁺ ( for example, a fluorine-containing polymer having a carboxyl group or a sulfo group). Thus, the polymer is more likely to dissolve in water or ethanol, as mentioned below, which is preferred.

[0444] This binder is dissolved in a mixed solution of water and ethanol. The volume ratio between water and ethanol is preferably 10: 1 to 1:10, more preferably 5: 1 to 1: 5, even more preferably 2: 1 to 1: 2. The particles of inorganic material are dispersed in the dissolving liquid by means of a ball mill, thereby forming a coating liquid. In this case, it is also possible to correct the average particle size and the like of particles by adjusting the duration and speed of rotation during dispersion. The preferred amount of the mixed particles of inorganic material and binder is as mentioned above.

[0445] The concentration of the particles of inorganic material and binder in the coating liquid is not particularly limited, but a free-flowing coating liquid is preferable. This makes it possible to uniformly apply the ion exchange membrane to the surface.

[0446] In addition, a surfactant may be added to the dispersion when particles of inorganic material are dispersed. As the surfactant, nonionic surfactants are preferred and examples include HS-210, NS-210, P-210 and E-212 from NOF CORPORATION.

[0447] The resulting coating liquid is applied to the surface of the ion exchange membrane by spray application or roller coating, thereby forming an ion exchange membrane.

[0448] [Microporous Membrane]

The microporous membrane of the present embodiment is not particularly limited as long as the membrane can be formed to form an electrode laminated article for electrolysis as mentioned above. A variety of microporous membranes can be used.

The porosity of the microporous membrane of the present embodiment is not particularly limited, but may be, for example, 20 to 90, and preferably 30 to 85. The above porosity can be calculated by the following formula:

Porosity = (1– (dry weight of the membrane) / (weight calculated from the volume, calculated from the values of the thickness, width and length of the membrane, and the density of the membrane material)) × 100

The average pore size in the microporous membrane of the present embodiment is not particularly limited and may be, for example, 0.01 µm to 10 µm, preferably 0.05 µm to 5 µm. With regard to the average pore size, for example, the membrane is cut vertically in the direction of thickness, and the cross section is examined by field emission scanning electron microscopy (FE-SEM). The average pore size can be obtained by measuring the diameter of about 100 pores and averaging the results.

The thickness of the microporous membrane of the present embodiment is not particularly limited and may be, for example, 10 µm to 1000 µm, preferably 50 µm to 600 µm. The above thickness can be measured using, for example, a micrometer (manufactured by Mitutoyo Corporation) or the like.

Specific examples of a microporous membrane as above include Zirfon Perl UTP 500 manufactured by Agfa (also referred to as a Zirfon membrane in this embodiment) and are described in International Publication No. WO 2013-183584 and International Publication No. WO 2016-203701.

[0449] In the present embodiment, the membrane preferably comprises a first ion exchange resin layer and a second ion exchange resin layer having an EW (ion exchange capacity) value different from the EW of the first ion exchange resin layer. In addition, the membrane preferably contains a first ion exchange resin layer and a second ion exchange resin layer having a different functional group than the functional group in the first ion exchange resin layer. The ion exchange capacity can be adjusted by the introduced functional group, and the functional groups that can be introduced are as mentioned above.

[0450] [Attachment Area]

In the present embodiment, the electrolysis electrode is fixed in at least one region of the membrane surface, and in <Third Embodiment> one or two or many regions are also referred to as attachment regions. The attachment area in the present embodiment is not particularly limited as long as the area is a portion whose purpose is to prevent the electrolysis electrode from separating from the membrane and to attach the membrane to the electrolysis electrode. For example, the electrolysis electrode itself serves as a fastening means to define the attachment area, or a fastener that is separate from the electrolysis electrode can serve as a fastening means to define the attachment area. The attachment area in the present embodiment may be present only at a position corresponding to a conductive surface during electrolysis, or may be extended to a position corresponding to a non-conductive surface. The "conductive surface" corresponds to an area designed to allow electrolyte migration between the anode chamber and the cathode chamber. “Non-conductive surface” means an area other than a conductive surface.

In addition, in the present embodiment, the portion of the attachment area on the membrane surface (hereinafter referred to simply as "fraction α") will be more than 0% and less than 93%. The above proportion can be defined as the proportion of the area of the attachment area (hereinafter referred to simply as "area S3") in the surface area of the membrane (hereinafter referred to simply as "area S1"). In the present embodiment, the “membrane surface” means the surface of the side on which the electrode for electrolysis is present, among the surfaces that the membrane has. The area not covered by the electrolysis electrode in the above membrane surface is also included in the area S1.

From the viewpoint of improving the stability of the laminated article formed by the membrane and the electrolysis electrode, the fraction α (= 100 × S3 / S1) is preferably 0.00000001% or more, more preferably 0.0000001% or more. In contrast, as per standard technology, in the case of the membrane and the electrolysis electrode tightly connected to each other over the entire contact surface between them in a manner such as thermocompression (i.e. in a situation where the proportion is 100%), the entire contact surface of the electrode rests against membrane and thereby physically adheres to it. Such an area of adhesion prevents the migration of sodium ions in the membrane, thereby significantly increasing the electrical voltage. In the present embodiment, in order to create sufficient space for free migration of ions, the above proportion is less than 93%, preferably 90% or less, more preferably 70% or less, even more preferably less than 60%.

[0451] In the present embodiment, from the viewpoint of achieving better electrolysis performance, it is preferable to adjust the area of the region of the conductive surface only (hereinafter simply referred to as “S3’ ”) in the attachment area (S3 area). That is, it is preferable to adjust the area fraction S3 '(hereinafter simply referred to as “β fraction”) in the conductive surface area (hereinafter referred to simply as “S2 area”). The area S2 can be identified as the surface area of the electrolysis electrode (details will be described below). More specifically, in the present embodiment, the proportion β (= 100 × S3 '/ S2) is preferably more than 0% and less than 100%, more preferably 0.0000001% or more and less than 83%, more preferably 0.000001% or more and 70% or less, even more preferably 0.00001% or more and 25% or less.

[0452] The above-described proportions of α and β can be measured, for example, as follows:

First, the surface area S1 of the membrane is calculated. Then, the area S2 of the electrolysis electrode is calculated. The areas S1 and S2 can here be identified as an area when the membrane-electrolysis electrode laminate is viewed from the side of the electrolysis electrode (see Figure 57).

The shape of the electrolysis electrode is not particularly limited, and the electrode may have holes. In the case where the shape is a mesh or the like that has holes and the open porosity ratio is less than 90% (i) as for S2, the hole portions are included in the area S2. In contrast, in the case where the open porosity ratio is 90% or more (ii), the area excluding the hole portions is used to calculate S2 in order to achieve sufficient electrolysis capacity. The open porosity ratio specified here is a numerical value (%; 100 × S '/ S ") obtained by dividing the total area S' of the hole portions in the electrolysis electrode by the area S" of the electrolysis electrode, which is obtained when the hole portions are included. into the area.

The area of the attachment area (area S3 and area S3 ') will be explained below.

As described above, the fraction α (%) of the area on the membrane surface can be determined by calculating 100 × (S3 / S1). In addition, the area fraction β (%) of the area corresponding only to the conductive surface of the attachment area relative to the area of the conductive surface can be determined by calculating 100 × (S3 ’/ S2).

More specifically, the measurement can be performed in the manner described in the Examples below.

[0453] The membrane surface area S1, identified as above, is not particularly limited, but is preferably 1 times or more and 5 times or less, more preferably 1 times or more and 4 times or less, yet more preferably 1 times or more and 3 times or less the area S2 of the conductive surface.

[0454] In the present embodiment, the attachment configuration is not intended to be limited, but, for example, the attachment configuration shown below by way of examples may be applied. Only one mounting configuration may be used, or two or more mounting configurations may be used in combination.

[0455] In the present embodiment, at least a portion of the electrolysis electrode preferably penetrates the membrane and is thereby fixed in the attachment region. This aspect will be described using Figure 47A.

In Figure 47A, at least a portion of the electrolysis electrode 2 penetrates the membrane 3 and is thereby secured. As shown in Figure 47A, a portion of the electrolysis electrode 2 penetrates the membrane 3. Figure 47A shows an example in which the electrolysis electrode 2 is a metal porous electrode. That is, in Figure 47A, a plurality of portions of the electrolysis electrode 2 are shown as separate, but the portions are continuous. Thus, a cross-section of a solid metal porous electrode is shown (the same applies in Figures 48-51 below).

In the configuration of the electrode, when the membrane 3 in a predetermined position (the position that is the attachment region) is pressed against the electrolysis electrode 2, for example, a part of the membrane 3 is pressed into the geometry of the protrusions or the geometry of the holes on the surface of the electrolysis electrode 2. Then, the depressions on the surface of the electrode and the protrusions around the holes penetrate the membrane 3 and preferably penetrate the outer surface 3b of the membrane 3, as shown in Figure 47A.

[0456] As described above, the attachment pattern in Figure 47A can be formed by pressing the membrane 3 against the electrolysis electrode 2. In this case, the membrane 3 is softened by heating and then subjected to thermal compression and thermal vacuum treatment. The electrolysis electrode 2 then penetrates the membrane 3. Alternatively, the membrane 3 can be used in a molten state. In this case, the membrane 3 is preferably sucked from the outer surface 2b side (rear surface side) of the electrolysis electrode 2 in the state shown in FIG. 47B. The area in which the membrane 3 is pressed into the electrolysis electrode 2 constitutes the "attachment area".

[0457] The mount configuration shown in FIG. 47A can be viewed with a magnifying glass (loupe), optical microscope, or electron microscope. Since the electrolysis electrode 2 has penetrated the membrane 3, it is possible to evaluate the attachment configuration in FIG. 47A by testing the conductivity between the outer surface 3b of the membrane 3 and the outer surface 2b of the electrolysis electrode 2 using a tester or the like.

[0458] In Figure 47A, the penetration portions of the membrane separating the anode compartment and the cathode compartment are preferably impermeable to the electrolyte solution. Thus, the pore size in the penetration site is preferably small enough to prevent electrolyte from penetrating through the penetration site. More specifically, it is preferable to exhibit characteristics comparable to the characteristics of the membrane having no penetration portion when the electrolysis test is performed. Alternatively, the piercing site is preferably treated to prevent the penetration of the electrolyte solution. It is preferable to use a material at the permeation site that is not washed out or decomposed by the electrolyte solution of the anode chamber, the products formed in the anode chamber, the electrolyte solution of the cathode chamber and the products formed in the cathode chamber. For example, EPDM and fluorine resins are preferred. More preferred is a fluorine-containing resin having an ion exchange group.

[0459] In the present embodiment, at least a portion of the electrolysis electrode is preferably located inside the membrane and thereby fixed in the attachment region. This aspect will be described using Figure 48A.

[0460] As described above, the surface of the electrolysis electrode 2 has a protrusion geometry and a hole geometry. In the embodiment shown in FIG. 48A, a portion of the electrode surface enters the membrane 3 to reach a predetermined position (the position that is the attachment region) and is thereby secured. The attachment configuration shown in FIG. 48A can be formed by pressing the membrane 3 into the surface of the electrolysis electrode 2. In this case, the fastening configuration of Figure 48A is preferably created by softening the membrane 3 by heating, and then by thermocompression or thermal vacuum treatment of the membrane 3. Alternatively, the fastening configuration of Figure 48A can be formed by melting the membrane 3. In this case, the membrane 3 is preferably sucked from the outside surfaces 2b (sides of the rear surface) of the electrode 2 for electrolysis.

[0461] The mounting configuration shown in FIG. 48A can be observed with a magnifying glass (loupe), an optical microscope, or an electron microscope. Particularly preferred is a method comprising subjecting the sample to a resin embedding treatment, then generating a cross-section with a microtome and examining the cross-section. In the attachment configuration shown in FIG. 48A, the electrolysis electrode 2 does not penetrate the membrane 3. Thus, the conductivity test cannot detect conductivity between the outer side 3b of the membrane 3 and the outer surface 2b of the electrolysis electrode 2.

[0462] In the present embodiment, it is preferable to additionally have an attachment member for securing the membrane and the electrolysis electrode. This aspect will be described using Figures 49A-C.

[0463] The attachment configuration shown in FIG. 49A is a configuration in which an attachment member 7 is used that is separate from the electrolysis electrode 2 and the membrane 3, and the attachment member 7 penetrates and thereby secures the electrolysis electrode 2 and the membrane 3. Electrode 2 for electrolysis need not be pierced by the fastener 7, and must be fixed with the fastener 7 so as not to separate from the membrane 3. The material for the fastener 7 is not particularly limited, and materials consisting of, for example, metal, resin or the like. Examples of the metal include nickel, nichrome, titanium, and stainless steel (SUS). Their oxides can be used. Examples of the resin that can be used include fluorine resins (e.g., polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkoxyethylene (PFA) copolymers, tetrafluoroethylene-ethylene copolymers (ETFE), membrane materials 3 described below, polyvinylidene fluoride) ethylene (PVDF) –Diene rubber (EPDM), polyethylene (PP), polypropylene (PE), nylon and aramid.

For example, the present embodiment employs a filamentary fastener 7 (filamentary metal or polymer) for sewing at a predetermined position (fastening region position) between the outer surface 2b of the electrolysis electrode 2 and the outer surface 3b of the membrane 3, as shown in Figures 49B and C. The filamentous polymer is not particularly limited, but examples thereof include PTFE yarns. It is also possible to secure the electrolysis electrode 2 to the membrane 3 using fastening means such as pins.

[0464] In Figures 49A-C, the electrolyte solution preferably does not penetrate the anode-cathode compartment separating membrane at the piercing site. Thus, the pore size at the penetration site is preferably small enough to prevent the electrolyte solution from penetrating through the penetration site. More specifically, it is preferable to exhibit characteristics comparable to the characteristics of the membrane having no penetration portion when the electrolysis test is performed. Alternatively, the piercing site is preferably treated to prevent the penetration of the electrolyte solution. It is preferable to use a material at the permeation site that is not washed out or decomposed by the electrolyte solution of the anode chamber, the products formed in the anode chamber, the electrolyte solution of the cathode chamber and the products formed in the cathode chamber. For example, EPDM and fluorine resins are preferred. More preferred is a fluorine-containing resin having an ion exchange group.

[0465] The attachment configuration shown in FIG. 50 is a configuration in which attachment is achieved by an organic resin (adhesive layer) interposed between the electrolysis electrode 2 and the membrane 3. That is, FIG. 50 shows a configuration in which an organic resin is used as an attachment. of the element 7 is placed in a predetermined position (the position of the attachment region) between the electrolysis electrode 2 and the membrane 3, to thereby secure them by gluing. For example, an organic resin is applied to the inner surface 2a of the electrolysis electrode 2, the inner surface 3a of the membrane 3, or one or both of the inner surface 2a of the electrolysis electrode 2 and the inner surface 3a of the membrane 3. Then, the attachment configuration shown in FIG. 50 can be formed by laminating the electrolysis electrode 2 to the membrane 3. Materials for the organic resin are not specifically limited, but examples thereof that can be used include fluorine resins (e.g., PTFE, PFA, and ETFE), and resins like the materials constituting the membrane 3, such as mentioned above. Commercially available fluorine adhesives and PTFE dispersions can also be used, as appropriate. In addition, multipurpose vinyl acetate adhesives, adhesives based on ethylene-vinyl acetate copolymers, adhesives based on acrylic resins, α-olefin adhesives, adhesives based on styrene-butadiene rubber latexes, adhesives based on vinyl chloride nitric resins, chlorinated adhesives , urethane rubber adhesives, epoxy adhesives, silicone resin adhesives, modified silicone adhesives, epoxy modified silicone resin adhesives, silylated urethane resin adhesives, cyanoacrylate adhesives, and the like.

In the present embodiment, organic resins that dissolve in an electrolyte solution or dissolve or decompose during electrolysis can be used. Examples of organic resins that dissolve in electrolyte solution, or dissolve or decompose during electrolysis include, but are not limited to, vinyl acetate adhesives, ethylene vinyl acetate copolymer adhesives, acrylic resin adhesives, α-olefin adhesives, styrene-butadiene rubber latexes, adhesives based on vinyl chloride resins, chloroprene adhesives, nitrile rubber adhesives, adhesives based on urethane rubbers, epoxy adhesives, adhesives based on silicone resins, modified silicone adhesives based on adhesives, adhesives based on adhesives resins and cyanoacrylate adhesives.

The mounting configuration shown in FIG. 50 can be observed with an optical microscope or an electron microscope. Particularly preferred is a method comprising subjecting the sample to a resin embedding treatment, then generating a cross-section with a microtome and examining the cross-section.

[0466] In the present embodiment, at least a portion of the fastener preferably grips the membrane and the electrolysis electrode from the outside. This aspect will be described using Figure 51A.

The fastening configuration shown in FIG. 51A is a configuration in which the electrolysis electrode 2 and the membrane 3 are clamped outwardly and fixed. That is, the outer surface 2b of the electrolysis electrode 2 and the outer surface 3b of the membrane 3 are sandwiched between and fastened by the clamping means (fixture) as the fastening member 7. In the fastening configuration shown in FIG. 51A, the state in which the clamping means engages with the electrode 2 is also included. electrolysis and membrane 3. Examples of clamping means include tape and paper clips.

In the present embodiment, a clamping member that dissolves in an electrolyte solution can be used. Examples of a clamping member that dissolves in an electrolyte solution include PET tape and staples, and PVA tape and staples.

[0467] In the attachment configuration shown in Figure 51A, unlike the examples according to Figures 47-50, the electrolysis electrode 2 and the membrane 3 are not connected at the interface between them, but the inner surface 2a of the electrolysis electrode 2 and the inner surface 3a of the membrane 3 only adjoin each other or are opposite each other. By removing the clamping element, it is possible to release the electrolysis electrode 2 and the membrane 3 from the fixed state and separate the electrolysis electrode 2 from the membrane 3.

Although not shown in Figure 51A, it is also possible to secure the electrolysis electrode 2 and membrane 3 using a clamping member in the electrolytic cell.

For example, you can bend the PTFE tape back to secure the diaphragm and electrode.

[0468] In addition, in the present embodiment, at least a part of the fastening member preferably fixes the membrane and the electrolysis electrode by magnetic force. This aspect will be described using Figure 51B.

The fastening configuration shown in FIG. 51B is a configuration in which the electrolysis electrode 2 and the membrane 3 are clamped outwardly and fixed. The difference from the example in Figure 51A is that a pair of magnets is used as the clamping member, which constitutes the holding member. In this aspect of the attachment configuration shown in FIG. 51B, the laminate 1 is attached to the electrolysis cell. Thereafter, during operation of the cell, the clamping member can be left as it is, or it can be removed from the laminate 1.

Although not shown in Figure 51B, it is also possible to secure the electrolysis electrode 2 and membrane 3 using a clamping member in the electrolytic cell. When a magnetic material that adheres to a magnet is used as part of the material for an electrolytic cell, one fastening material is placed on the surface side of the membrane. Then the fastening material and the electrolytic cell can be routed and fixed between the electrolysis electrode 2 and the membrane 3.

[0469] A plurality of lines of attachment areas may be provided. That is, 1, 2, 3, etc., n lines of attachment areas may be placed from one side of the contour towards the inner side of the laminate 1. n represents an integer of 1 or more. The m – th (m <n) line of the fastening areas and the L – th (m <L≤n) line of the fastening areas can in each case be formed having a different fastening pattern.

[0470] The line of attachment regions formed in the electrically conductive region preferably has a linearly symmetrical shape. This allows you to control the concentration of mechanical stresses. For example, when orthogonally intersecting directions are designated X-direction and Y-direction, you can configure the retention area by placing each line of retention areas in X-direction and Y-direction, or place multiple lines of retention areas at equal intervals in X-direction and Y-direction. Y-direction. The number of lines of the attachment areas in each of the X-direction and Y-direction is not limited, but is preferably 100 or less in the X-direction and the Y-direction. From the viewpoint of achieving planarity of the electrically conductive region, the number of lines of the attachment regions is preferably 50 or less in each of the X-direction and Y-direction.

[0471] When the attachment area in the present embodiment has the attachment configuration shown in FIG. 47A or FIG. 49, a sealing / sealing material is preferably applied to the surface of the membrane in the attachment area in order to prevent short circuit caused by contact between the anode and cathode. The materials described for the aforementioned adhesives can be used as a sealing material.

[0472] When the fastener is used, when determining the area S3 and the area S3 'as for the area over which the fastener overlaps, the overlapping portion is not included in the area S3 and the area S3'. For example, when fastening is performed using the above-mentioned PTFE yarns as fasteners, the area in which the PTFE yarns intersect with each other is not included as an overlapping portion in the area. When fastening is performed using the above PTFE tapes, the area where the PTFE tapes intersect with each other is not included as an overlapping portion in the area.

When fixing is performed using the above PTFE yarn or adhesive as the fixing member, the area on the back side of the electrolysis electrode and / or membrane is also included in the S3 area and the S3 'area.

[0473] The laminated article in the present embodiment may have different attachment areas as mentioned above, but the electrolysis electrode preferably satisfies the aforementioned "applied force" value, especially in the area in which there is no attachment area (non-fixed area). That is, the force applied per unit mass · unit area of the electrode for electrolysis is preferably less than 1.5 N / (mg · cm ² ).

[0474] [Electrolyzer]

The electrolyzer of the present embodiment comprises the laminated article of the present embodiment. Next, a case of performing conventional salt electrolysis using an ion exchange membrane as the membrane will be given by way of example, and one embodiment of the electrolytic cell will be described in detail.

[0475] [Electrolytic Cell]

Figure 52 illustrates a sectional view of an electrolytic cell 1.

The electrolytic cell 1 contains an anode chamber 10, a cathode chamber 20, a dividing wall 30 located between the anode chamber 10 and the cathode chamber 20, an anode 11 located in the anode chamber 10, and a cathode 21 located in the cathode chamber 20. If necessary, an electrolytic cell 1 has a substrate 18a and a reverse current absorbing layer 18b formed on the substrate 18a, and may include a reverse current absorber 18 disposed in the cathode chamber. The anode 11 and the cathode 21, which are part of the electrolytic cell 1, are electrically connected to each other. In other words, the electrolytic cell 1 contains the following cathode structure. The cathode structure 40 comprises a cathode chamber 20, a cathode 21 disposed in the cathode chamber 20, and a reverse current absorber 18 disposed in the cathode chamber 20, the reverse current absorber 18 having a substrate 18a and a reverse current absorbing layer 18b formed on the substrate 18a as shown in Figure 56, and the cathode 21 and the reverse current absorbing layer 18b are electrically connected. In addition, the cathode chamber 20 has a current collector 23, a holder 24 supporting the current collector, and a metal elastic body 22. The metal elastic body 22 is placed between the current collector 23 and the cathode 21. The holder 24 is located between the current collector 23 and the partition 30. The current collector 23 is electrically connected to cathode 21 through the metal elastic body 22. The separating partition 30 is electrically connected to the current collector 23 through the holder 24. Accordingly, the separating partition 30, the holder 24, the current collector 23, the metal elastic body 22 and the cathode 21 are electrically connected to each other. The cathode 21 and the reverse current absorbing layer 18b are electrically connected. The cathode 21 and the reverse current absorbing layer 18b may be connected directly, or may be connected indirectly through a down conductor, a holder, a metal resilient body, a baffle, or the like. The entire surface of the cathode 21 is preferably coated with a catalyst layer for the reduction reaction. The form of the electrical connection may be a form in which the baffle 30 and the support 24, the support 24 and the collector 23 and the collector 23 and the metal resilient body 22 are in each case directly connected to each other, and the cathode 21 is laminated on the metal resilient body 22. Examples methods for directly attaching these structural elements to each other include welding and the like. Alternatively, the reverse current absorber 18, cathode 21, and current collector 23 may be collectively referred to as cathode structure 40.

[0476] Figure 53 illustrates a cross-sectional view of two electrolytic cells 1 that are adjacent in electrolytic cell 4. Figure 54 shows electrolytic cell 4. Figure 55 shows a step of assembling electrolytic cell 4. As shown in Figure 53, electrolytic cell 1, cation exchange membrane 2 and electrolytic cell 1 are placed sequentially in the order shown. Ion exchange membrane 2 is located between the anode chamber of one electrolytic cell 1 of two electrolytic cells that are adjacent in the electrolyzer and the cathode chamber of another electrolytic cell 1. That is, the anode chamber 10 of the electrolytic cell 1 and the cathode chamber 20 of the adjacent electrolytic cell 1 are separated by a cation exchange membrane 2. As shown in Figure 54, electrolyzer 4 consists of a plurality of electrolytic cells 1 connected in series through an ion exchange membrane 2. That is, electrolyzer 4 is a bipolar electrolyzer including a plurality of electrolytic cells 1 in series and ion exchange membranes 2, in each case arranged between adjacent electrolytic cells 1. As shown in Figure 55, the cell 4 is assembled by placing a plurality of electrolytic cells 1 in series through the ion exchange membrane 2 and bonding the cells by means of a clamping device 5.

[0477] The cell 4 has an anode terminal 7 and a cathode terminal 6 that are connected to a power supply. An anode 11 of an electrolytic cell 1 located at the farthest end of a plurality of electrolytic cells 1 connected in series in an electrolysis cell 4 is electrically connected to an anode terminal 7. A cathode 21 of an electrolytic cell located at an end opposite to the anode terminal 7 among the plurality of electrolytic cells 1, connected in series in the electrolytic cell 4, electrically connected to the cathode terminal 6. Electric current during electrolysis flows from the side of the anode terminal 7 through the anode and the cathode of each electrolytic cell 1 towards the cathode terminal 6. At both ends of the connected electrolytic cells 1 there may be an electrolytic cell, having only an anode chamber (anode outlet cell), and an electrolytic cell having only a cathode chamber (cathode outlet cell). In this case, the anode terminal 7 is connected to an anode terminal cell located at one end, and the cathode terminal 6 is connected to a cathode terminal cell located at the other end.

[0478] In the case of brine electrolysis, brine is supplied to each anode chamber 10, and pure water or low-concentration aqueous sodium hydroxide solution is supplied to each cathode chamber 20. Each liquid is supplied from an electrolyte solution supply pipe (not shown in the figure) through a hose for supplying an electrolyte solution (not shown in the figure) to each electrolytic cell 1. The electrolyte solution and electrolysis products are removed from the pipe for removing the electrolyte solution (not shown in the figure). During electrolysis, sodium ions in the brine migrate from the anode chamber 10 of one electrolytic cell 1 through the ion exchange membrane 2 to the cathode chamber 20 of the adjacent electrolytic cell 1. Thus, the electric current during electrolysis flows in the direction in which the electrolytic cells 1 are connected in series. That is, an electric current flows through the cation exchange membrane 2 from the anode chamber 10 towards the cathode chamber 20. When the brine is electrolyzed, chlorine gas is generated on the anode 11 side, and sodium hydroxide (dissolved) and hydrogen gas are generated on the cathode 21 side.

[0479] (Anode chamber)

The anode chamber 10 has an anode 11 or an anode supply conductor 11. When the electrolysis electrode of the present embodiment is inserted on the anode side, 11 serves as an anode supply conductor. When the electrolysis electrode of the present embodiment is not inserted on the anode side, 11 serves as an anode. The anode chamber 10 has an anode side electrolyte solution supply unit that supplies electrolyte solution to the anode chamber 10, a baffle plate that is positioned above the anode side electrolyte solution supply unit so as to be substantially parallel or inclined with respect to the dividing wall 30, and a gas-liquid an anode-side separator located above the baffle plate for separating the gas from the electrolyte solution including the admixed gas.

[0480] (Anode)

When the electrolysis electrode of the present embodiment is not inserted on the anode side, the anode 11 is in the frame of the anode chamber 10. A metal electrode such as a so-called DSA (R) can be used as the anode 11. DSA is an electrode including a titanium substrate, the surface of which is coated with an oxide including ruthenium, iridium and titanium as components.

As for the shape, any of a perforated metal sheet, a nonwoven fabric, a porous metal, an expanded metal sheet, an electrospinning metal porous foil, a so-called woven metal mesh formed by interlacing of thin metal filaments, and the like can be used.

[0481] (Anode supply conductor)

When the electrode for electrolysis of the present embodiment is inserted on the anode side, an anode supply conductor 11 is provided on the frame of the anode chamber 10. A metal electrode such as a so-called DSA (R) can be used as the anode supply conductor 11, and can also be used titanium without catalytic coating. Alternatively, a DSA having a thinner catalytic coating can also be used. In addition, an already used anode can also be used.

As for the shape, any of a perforated metal sheet, a nonwoven fabric, a porous metal, an expanded metal sheet, an electrospinning metal porous foil, a so-called woven metal mesh formed by interlacing of thin metal filaments, and the like can be used.

[0482] (Anode side electrolyte solution supply unit)

An anode-side electrolyte solution supply unit that supplies an electrolyte solution to the anode chamber 10 is connected to a pipe for supplying an electrolyte solution. The anode side electrolyte solution supply unit is preferably disposed under the anode chamber 10. As the anode side electrolyte solution supply unit, for example, a pipe on the surface of which lumen portions (dispersion tube) and the like can be used. Such a tube is more preferably located along the surface of the anode 11 and parallel to the bottom 19 of the electrolytic cell. This pipe is connected to a pipe for supplying an electrolyte solution (a liquid supply pipe), which supplies an electrolyte solution to an electrolytic cell 1. The electrolyte solution supplied from a liquid supply pipe is passed through a pipe into an electrolytic cell 1 and is fed from holes made on the pipe surface inside the anode chambers 10. Placing the pipe along the surface of the anode 11 and parallel to the bottom 19 of the electrolytic cell is preferable because the electrolyte solution can be uniformly supplied to the inside of the anode chamber 10.

[0483] (Anode side gas-liquid separator)

The anode-side gas-liquid separator is preferably located above the baffle plate. The purpose of the anode-side gas-liquid separator is to separate the generated gas, such as chlorine gas, from the electrolyte solution during electrolysis. Unless otherwise specified, "above" means an upward direction in an electrolytic cell 1 in FIG. 52, and "under" means a downward direction in an electrolytic cell 1 in FIG. 52.

[0484] The gas generated during electrolysis evolved in the electrolytic cell 1 and the electrolyte solution form a mixed phase (gas-liquid mixed phase), which is then discharged from the system. As a consequence, pressure fluctuations within the electrolytic cell 1 cause vibration, which can lead to physical damage to the ion exchange membrane. To prevent this phenomenon, the electrolytic cell 1 of the present embodiment is preferably equipped with an anode-side gas-liquid separator for separating gas from liquid. The anode-side gas-liquid separator is preferably provided with a defoamer plate to eliminate bubbles. When a gas / liquid mixed phase stream flows through the defoamer plate, the bubbles burst, thereby separating the electrolyte solution from the gas. As a result, vibration during electrolysis can be prevented.

[0485] (Baffle plate)

The baffle plate is preferably positioned above the anode side electrolyte solution supply unit and is positioned substantially parallel or obliquely with respect to the baffle 30. The baffle plate is a baffle plate that controls the flow of electrolyte solution into the anode chamber 10. When the baffle plate is provided, it can cause circulation electrolyte solution (brine or the like) inside the anode chamber 10, thereby making the concentration more uniform. To create internal circulation, the baffle plate is preferably positioned so as to separate the space near the anode 11 from the space near the baffle 30. For this reason, the baffle plate is preferably positioned so that it is opposite the surface of the anode 11 and the surface of the baffle 30. In the space near the anode separated by the baffle plate, electrolysis occurs, the concentration of the electrolyte solution (brine concentration) decreases, and a generated gas such as chlorine gas is released. This leads to a difference in the specific gravity of the gas-liquid mixture between the space near the anode 11 and the space near the dividing wall 30, separated by a baffle plate. Using this difference, it is possible to stimulate the internal circulation of the electrolyte solution in the anode chamber 10, thereby making the concentration distribution of the electrolyte solution in the anode chamber 10 more uniform.

[0486] Although not shown in Figure 52, a down conductor may also be additionally provided within the anode chamber 10. The material and configuration of such a current collector can be the same as for the aforementioned collector of the cathode chamber. In the anode chamber 10, the anode 11 itself can also serve as a down conductor.

[0487] (Divider)

The dividing wall 30 is disposed between the anode chamber 10 and the cathode chamber 20. The dividing wall 30 may be referred to as a separator, and the anode chamber 10 and the cathode chamber 20 are separated from each other by a dividing wall 30. As the dividing wall 30, a baffle known as a separator can be used. electrolysis, and an example thereof comprises a baffle formed by welding a nickel-containing plate on the cathode side and a titanium-containing plate on the anode side.

[0488] (Cathode Chamber)

In the cathode compartment 20, when the electrolysis electrode of the present embodiment is inserted on the cathode side, 21 serves as a cathode supply conductor. When the electrolysis electrode of the present embodiment is not inserted on the cathode side, 21 serves as the cathode. When a return current absorber is present, the cathode or cathode supply conductor 21 is electrically connected to the return current absorber. Cathode chamber 20, like anode chamber 10, preferably has a cathode-side electrolyte solution supply unit and a cathode-side gas-liquid separator. Among the components constituting the cathode compartment 20, components similar to those constituting the anode compartment 10 will not be described.

[0489] (Cathode)

When the electrolysis electrode of the present embodiment is not inserted on the cathode side, the cathode 21 is in the frame of the cathode chamber 20. The cathode 21 preferably has a nickel substrate and a catalyst layer that covers the nickel substrate. Examples of catalyst bed components include elements such as Ru, C, Si, P, S, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Rh, Pd , Ag, Cd, In, Sn, Ta, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho , Er, Tm, Yb and Lu, as well as oxides and hydroxides of these metals. Examples of the method for forming the catalyst layer include electrodeposition, alloy electrodeposition, dispersion / composite electrodeposition, CVD, FOPP, pyrolysis, and sputtering. These methods can be used in combination. The catalyst bed can have multiple layers and multiple elements as needed. The cathode 21 can be subjected to a reduction treatment, if necessary. Nickel, nickel alloys and nickel-plated iron or stainless steel can be used as the substrate for the cathode 21.

As for the shape, any of a perforated metal sheet, a nonwoven fabric, a porous metal, an expanded metal sheet, an electrospinning metal porous foil, a so-called woven metal mesh formed by interlacing of thin metal filaments, and the like can be used.

[0490] (Cathode Supply Conductor)

When the electrode for electrolysis of the present embodiment is inserted on the cathode side, a cathode supply conductor 21 is provided in the frame of the cathode chamber 20. The cathode supply conductor 21 may be coated with a catalyst component. The catalyst component can be a component that is initially used as a cathode and is stored. Examples of catalyst bed components include elements such as Ru, C, Si, P, S, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Rh, Pd , Ag, Cd, In, Sn, Ta, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho , Er, Tm, Yb and Lu, as well as oxides and hydroxides of these metals. Examples of the method for forming the catalyst layer include electrodeposition, alloy electrodeposition, dispersion / composite electrodeposition, CVD, FOPP, pyrolysis, and sputtering. These methods can be used in combination. The catalyst bed can have multiple layers and multiple elements as needed. Nickel, nickel alloys and nickel-plated iron or stainless steel without catalytic coating can be used. Nickel, nickel alloys and nickel-plated iron or stainless steel can be used as the substrate for the cathode supply conductor 21.

As for the shape, any of a perforated metal sheet, a nonwoven fabric, a porous metal, an expanded metal sheet, an electrospinning metal porous foil, a so-called woven metal mesh formed by interlacing of thin metal filaments, and the like can be used.

[0491] (Reverse current absorbing layer)

As the material for the layer that absorbs the reverse current, a material that is less noble in terms of the redox potential than the redox potential of the element for the aforementioned catalyst layer of the cathode can be selected. Examples include nickel and iron.

[0492] (Down conductor)

The cathode chamber 20 preferably contains a current collector 23. The current collector 23 improves the efficiency of current extraction. In the present embodiment, the collector 23 is a porous plate and is preferably disposed substantially parallel to the surface of the cathode 21.

[0493] The collector 23 preferably contains an electrically conductive metal such as nickel, iron, copper, silver and titanium. The current collector 23 can be a mixture, alloy or complex oxide of these metals. The collector 23 may be of any shape as long as the shape allows the collector to function and may be in the form of a plate or mesh.

[0494] (Metallic elastic body)

By placing the metal elastic body 22 between the current collector 23 and the cathode 21, each cathode 21 of a plurality of electrolytic cells 1 connected in series is pressed against the ion exchange membrane 2 to shorten the distance between each anode 11 and each cathode 21. Thus, it is possible to reduce the voltage applied to the entire plurality of electrolytic cells connected in series. cells 1. Reducing voltage helps to reduce power consumption. When the metal resilient body 22 is placed, the pressing pressure created by the metal resilient body 22 allows the electrolysis electrode to stably maintain its position in place when the laminated article containing the electrolysis electrode of the present embodiment is placed in the electrolytic cell.

[0495] As the metal resilient body 22, spring members such as coil and coil springs and damping mats can be used. As the metal elastic body 22, an element can be appropriately applied in consideration of mechanical stress due to pressure on the ion exchange membrane and the like. The metal resilient body 22 may be located on the surface of the collector 23 on the side of the cathode chamber 20, or may be provided on the surface of the partition wall on the side of the anode chamber 10. The two chambers are usually separated so that the cathode chamber 20 becomes smaller than the anode chamber 10. Thus In terms of frame strength and the like, the metal resilient body 22 is preferably placed between the collector 34 and the cathode 21 in the cathode chamber 20. The metal resilient body 22 preferably contains an electrically conductive metal such as nickel, iron, copper, silver and titanium.

[0496] (Holder)

The cathode chamber 20 preferably comprises a holder 24 which electrically connects the collector 23 to the baffle 30. This can achieve an efficient current flow.

[0497] The holder 24 preferably contains an electrically conductive metal such as nickel, iron, copper, silver, and titanium. The holder 24 can be of any shape as long as the holder can support the collector 23 and can be in the form of a rod, plate, or mesh. The holder 24 is in the form of a plate, for example. A plurality of holders 24 are disposed between the baffle 30 and the down conductor 23. The plurality of holders 24 are aligned so that their surfaces are parallel to each other. The holders 24 are located substantially perpendicular to the baffle 30 and the down conductor 23.

[0498] (Anode side seal and cathode side seal)

The anode side seal is preferably located on the surface of the frame constituting the anode chamber 10. The cathode side seal is preferably positioned on the surface of the frame constituting the cathode compartment 20. The electrolytic cells are interconnected such that the anode side seal in one electrolytic cell and the cathode side seal an ion exchange membrane 2 is laid on an adjacent electrolytic cell (see Figures 52 and 53). These seals can create airtightness at the junctions when a plurality of electrolytic cells 1 are connected in series through an ion exchange membrane 2.

[0499] The seals form a seal between the ion exchange membrane and the electrolytic cells. Specific examples of seals include picture frame-like rubber sheets in the center of which an opening is formed. The seals must be resistant to corrosive electrolyte solutions or generated gas and be functional for a long period of time. Thus, with regard to chemical resistance and hardness, vulcanized products and peroxide-crosslinked products of ethylene-propylene-diene rubber (EPDM-rubber) and ethylene-propylene rubber (EPM-rubber) are usually used as seals. Alternatively, if necessary, seals can be used in which the area in contact with the liquid (the area in contact with the liquid) is coated with a fluorine resin such as polytetrafluoroethylene (PTFE) and copolymers of tetrafluoroethylene and perfluoroalkyl vinyl ethers (PFA). These seals may in each case have an opening that does not impede the flow of the electrolyte solution, and the shape of the opening is not particularly limited. For example, a seal in the form of a picture frame is attached by means of an adhesive or the like along the peripheral edge of each opening of the anode chamber frame constituting the anode compartment 10 or the cathode compartment frame constituting the cathode compartment 20. Then, for example, in the case where two electrolytic cells 1 are connected through ion exchange membrane 2 (see Figure 53), each electrolytic cell 1 to which a seal is attached must be sealed by means of an ion exchange membrane 2. This seal can prevent electrolyte solution, alkali metal hydroxide, chlorine gas, hydrogen gas from escaping from the electrolytic cells 1 and the like formed by electrolysis.

[0500] (Ion exchange membrane 2)

The ion exchange membrane 2 is as described in the above section on the ion exchange membrane.

[0501] (Water electrolysis)

The electrolytic cell of the present embodiment as an electrolysis cell in the case of water electrolysis has a configuration in which an ion exchange membrane in the electrolysis cell for use in the case of the above conventional salt electrolysis is replaced with a microporous membrane. The supplied raw material, which is water, is different from the material for the electrolytic cell in the case of the above-mentioned conventional salt electrolysis. As for other components, parts similar to those of the electrolysis cell in the case of conventional salt electrolysis can also be used in a water electrolysis cell. Since chlorine gas is generated in the anode chamber in conventional salt electrolysis, titanium is used as the anode chamber material, but in the case of water electrolysis, only oxygen gas is emitted in the anode chamber. Thus, a material identical to that of the cathode chamber can be used. Nickel is one example of this. A catalytic coating for generating oxygen is suitable for coating the anode. Examples of the catalytic coating include metals, oxides and hydroxides of platinum group metals and metals from the transition metal group. For example, elements such as platinum, iridium, palladium, ruthenium, nickel, cobalt, and iron can be used.

[0502] <Fourth embodiment>

Here, a fourth embodiment of the present invention will be described in detail with reference to Figures 63-90.

[0503] [Electrolyzer]

The electrolyzer according to the fourth embodiment (hereinafter in the section <Fourth Embodiment> simply referred to as "the present embodiment") comprises an anode, an anode frame that supports the anode, an anode side seal that is disposed on the anode frame, a cathode that is opposite the anode, a cathode a frame that supports the cathode, a cathode side seal that is placed on the cathode frame, and a membrane-electrode laminated product for electrolysis, the laminated product being positioned between the anode-side seal and the cathode-side seal, with at least part of the laminated product being sandwiched between the anode seal side and cathode side seal, and the ventilation resistance measured under conditions of temperature 24 ° C, relative humidity 32%, piston speed 0.2 cm / s and ventilation volume 0.4 cm ³ / cm ² / s is 24 kPa s / m or less when the electrolysis electrode has a size of 50 mm × 50 mm. With the above-described configuration, the electrolysis cell of the present embodiment has excellent electrolysis performance and can also prevent membrane damage.

The electrolyzer of the present embodiment contains the above-mentioned structural elements, in other words, it contains an electrolytic cell. Next, a case of performing conventional salt electrolysis using an ion exchange membrane as the membrane will be given by way of example, and one embodiment of the electrolytic cell will be described in detail.

[0504] [Electrolytic Cell]

First, an electrolytic cell that can be applied as an integral part of the electrolytic cell of the present embodiment will be described. Figure 63 illustrates a sectional view of an electrolytic cell.

The electrolytic cell 1 contains an anode chamber 10, a cathode chamber 20, a dividing wall 30 located between the anode chamber 10 and the cathode chamber 20, an anode 11 located in the anode chamber 10, and a cathode 21 located in the cathode chamber 20. If necessary, an electrolytic cell 1 has a substrate 18a and a reverse current absorbing layer 18b formed on the substrate 18a, and may include a reverse current absorber 18 disposed in the cathode chamber. The anode 11 and the cathode 21, which are part of the electrolytic cell 1, are electrically connected to each other. In other words, the electrolytic cell 1 contains the following cathode structure. The cathode structure 40 comprises a cathode chamber 20, a cathode 21 disposed in the cathode chamber 20, and a reverse current absorber 18 disposed in the cathode chamber 20, the reverse current absorber 18 having a substrate 18a and a reverse current absorbing layer 18b formed on the substrate 18a as shown in Figure 67, and the cathode 21 and the reverse current absorbing layer 18b are electrically connected. In addition, the cathode chamber 20 has a current collector 23, a holder 24 supporting the current collector, and a metal elastic body 22. The metal elastic body 22 is placed between the current collector 23 and the cathode 21. The holder 24 is located between the current collector 23 and the partition 30. The current collector 23 is electrically connected to cathode 21 through the metal elastic body 22. The separating partition 30 is electrically connected to the current collector 23 through the holder 24. Accordingly, the separating partition 30, the holder 24, the current collector 23, the metal elastic body 22 and the cathode 21 are electrically connected to each other. The cathode 21 and the reverse current absorbing layer 18b are electrically connected. The cathode 21 and the reverse current absorbing layer 18b may be connected directly, or may be connected indirectly through a down conductor, a holder, a metal resilient body, a baffle, or the like. The entire surface of the cathode 21 is preferably coated with a catalyst layer for the reduction reaction. The form of the electrical connection may be a form in which the baffle 30 and the support 24, the support 24 and the collector 23 and the collector 23 and the metal resilient body 22 are in each case directly connected to each other, and the cathode 21 is laminated on the metal resilient body 22. Examples methods for directly attaching these structural elements to each other include welding and the like. Alternatively, the reverse current absorber 18, cathode 21, and current collector 23 may be collectively referred to as cathode structure 40.

[0505] Figure 64 illustrates a cross-sectional view of two electrolytic cells 1 that are adjacent in electrolytic cell 4. Figure 65 shows electrolytic cell 4. Figure 66 shows a step of assembling cell 4.

[0506] In a standard electrolytic cell, as shown in Figure 64A, an electrolytic cell 1, a membrane (here, a cation exchange membrane) 2, and an electrolytic cell 1 are placed in series in that order. Ion exchange membrane 2 is located between the anode chamber of one electrolytic cell 1 of two electrolytic cells that are adjacent in the electrolyzer and the cathode chamber of another electrolytic cell 1. That is, the anode chamber 10 of the electrolytic cell 1 and the cathode chamber 20 of the adjacent (adjacent) electrolytic cell 1 are separated by a cation exchange membrane 2.

Meanwhile, in the present embodiment, as shown in Figure 64B, an electrolytic cell 1, a laminated article 25 having a membrane (here, a cation exchange membrane) 2, and an electrolysis electrode (here, a refreshing cathode) 21a, and an electrolytic cell 1 are arranged in series in the specified order. Part of the laminated article 25 (upper end portion in FIG. 64B) is sandwiched between the anode seal 12 and the cathode seal 13.

[0507] As shown in Figure 65, the electrolytic cell 4 is composed of a plurality of electrolytic cells 1 connected in series through an ion exchange membrane 2. That is, the cell 4 is a bipolar electrolyzer including a plurality of electrolytic cells 1 in series and ion exchange membranes 2 in each case arranged between adjacent electrolytic cells 1. As shown in Figure 66, the electrolytic cell 4 is assembled by placing a plurality of electrolytic cells 1 in series through the ion exchange membrane 2 and bonding the cells by means of a clamping device 5.

[0508] Electrolyzer 4 has an anode lead 7 and a cathode lead 6 that are connected to a power supply. An anode 11 of an electrolytic cell 1 located at the farthest end of a plurality of electrolytic cells 1 connected in series in an electrolysis cell 4 is electrically connected to an anode terminal 7. A cathode 21 of an electrolytic cell located at an end opposite to the anode terminal 7 among the plurality of electrolytic cells 1, connected in series in the electrolytic cell 4, electrically connected to the cathode terminal 6. Electric current during electrolysis flows from the side of the anode terminal 7 through the anode and the cathode of each electrolytic cell 1 towards the cathode terminal 6. At both ends of the connected electrolytic cells 1 there may be an electrolytic cell, having only an anode chamber (anode outlet cell), and an electrolytic cell having only a cathode chamber (cathode outlet cell). In this case, the anode terminal 7 is connected to an anode terminal cell located at one end, and the cathode terminal 6 is connected to a cathode terminal cell located at the other end.

[0509] In the case of brine electrolysis, brine is supplied to each anode chamber 10, and pure water or low-concentration aqueous sodium hydroxide solution is supplied to each cathode chamber 20. Each liquid is supplied from an electrolyte solution supply pipe (not shown) through a hose for supplying an electrolyte solution (not shown in the figure) to each electrolytic cell 1. The electrolyte solution and electrolysis products are removed from the pipe for removing the electrolyte solution (not shown in the figure). During electrolysis, sodium ions in the brine migrate from the anode chamber 10 of one electrolytic cell 1 through the ion exchange membrane 2 to the cathode chamber 20 of the adjacent electrolytic cell 1. Thus, the electric current during electrolysis flows in the direction in which the electrolytic cells 1 are connected in series. That is, an electric current flows through the cation exchange membrane 2 from the anode chamber 10 towards the cathode chamber 20. When the brine is electrolyzed, chlorine gas is generated on the anode 11 side, and sodium hydroxide (dissolved) and hydrogen gas are generated on the cathode 21 side.

[0510] As mentioned above, the characteristics of the membrane, cathode and anode in the cell usually deteriorate due to the operation of the cell, and soon it becomes necessary to replace them with new ones. In the case of replacing only the membrane, the renewal can be accomplished in a simple way by removing the existing membrane between the electrolytic cells and inserting a new membrane between them, but replacing the anode or cathode by welding is difficult because specialized assembly is required.

Meanwhile, in the present embodiment, the laminated article 25 at its upper portion (upper end portion in FIG. 64B) is sandwiched between the anode seal 12 and the cathode seal 13 as described above. Specifically, in the example shown in Figure 64B, the membrane (here cation exchange membrane) 2 and the electrolysis electrode (here the renewal cathode) 21a can be attached to at least the upper end portion of the laminate by pressing away from the anode seal 12 towards the laminated article 25 and pressing away from the cathode seal 13 towards the laminated article 25. This situation is preferable since there is no need to attach the laminated article 25 (in particular, an electrolysis electrode) to an existing element (eg an existing cathode) by welding. That is, a case where both the electrolysis electrode and the membrane are sandwiched between the anode side seal and the cathode side seal is preferable because the efficiency can be improved during the renovation of the electrolyzer.

In addition, according to the configuration of the electrolysis cell of the present embodiment, the membrane and the electrolysis electrode are sufficiently secured as a laminated article, and thereby excellent electrolysis performance can be achieved.

[0511] (Anode chamber)

The anode chamber 10 has an anode 11 or an anode supply conductor 11. The supply conductor here means a worn electrode (ie, an existing electrode), an electrode not having a catalytic coating, and the like. When the electrolysis electrode of the present embodiment is inserted on the anode side, 11 serves as an anode supply conductor. When the electrolysis electrode of the present embodiment is not inserted on the anode side, 11 serves as an anode. The anode chamber 10 has an anode side electrolyte solution supply unit that supplies electrolyte solution to the anode chamber 10, a baffle plate that is positioned above the anode side electrolyte solution supply unit so as to be substantially parallel or inclined with respect to the dividing baffle 30, and an anode gas-liquid separator. side positioned above the baffle plate to separate the gas from the electrolyte solution including the admixed gas.

[0512] (Anode)

When the electrode for electrolysis of the present embodiment is not inserted on the anode side, the anode 11 is in the frame of the anode chamber 10 (i.e., in the anode frame). As the anode 11, a metal electrode such as a so-called DSA (R) can be used. DSA is an electrode including a titanium substrate, the surface of which is coated with an oxide including ruthenium, iridium and titanium as components.

As for the shape, any of a perforated metal sheet, a nonwoven fabric, a porous metal, an expanded metal sheet, an electrospinning metal porous foil, a so-called woven metal mesh formed by interlacing of thin metal filaments, and the like can be used.

[0513] (Anode supply conductor)

When the electrode for electrolysis of the present embodiment is inserted on the anode side, an anode supply conductor 11 is provided on the frame of the anode chamber 10. A metal electrode such as a so-called DSA (R) can be used as the anode supply conductor 11, and can also be used titanium without catalytic coating. Alternatively, a DSA having a thinner catalytic coating can also be used. In addition, an already used anode can also be used.

As for the shape, any of a perforated metal sheet, a nonwoven fabric, a porous metal, an expanded metal sheet, an electrospinning metal porous foil, a so-called woven metal mesh formed by interlacing of thin metal filaments, and the like can be used.

[0514] (Anode side electrolyte solution supply unit)

An anode-side electrolyte solution supply unit that supplies an electrolyte solution to the anode chamber 10 is connected to a pipe for supplying an electrolyte solution. The anode side electrolyte solution supply unit is preferably disposed under the anode chamber 10. As the anode side electrolyte solution supply unit, for example, a pipe on the surface of which lumen portions (dispersion tube) and the like can be used. Such a tube is more preferably located along the surface of the anode 11 and parallel to the bottom 19 of the electrolytic cell. This pipe is connected to a pipe for supplying an electrolyte solution (a liquid supply pipe), which supplies an electrolyte solution to an electrolytic cell 1. The electrolyte solution supplied from a liquid supply pipe is passed through a pipe into an electrolytic cell 1 and is fed from the holes made on the pipe surface to the inside of the anode chambers 10. The placement of the pipe along the surface of the anode 11 and parallel to the bottom 19 of the electrolytic cell is preferable because the electrolyte solution can be uniformly supplied to the inside of the anode chamber 10.

[0515] (Anode side gas-liquid separator)

The anode-side gas-liquid separator is preferably located above the baffle plate. The purpose of the anode-side gas-liquid separator is to separate the generated gas, such as chlorine gas, from the electrolyte solution during electrolysis. Unless otherwise specified, "above" means an upward direction in an electrolytic cell 1 in FIG. 63, and "under" means a downward direction in an electrolytic cell 1 in FIG. 63.

[0516] The gas generated during electrolysis evolved in the electrolytic cell 1 and the electrolyte solution form a mixed phase (gas-liquid mixed phase), which is then discharged from the system. As a consequence, pressure fluctuations within the electrolytic cell 1 cause vibration, which can lead to physical damage to the ion exchange membrane. To prevent this phenomenon, the electrolytic cell 1 of the present embodiment is preferably equipped with an anode-side gas-liquid separator for separating gas from liquid. The anode-side gas-liquid separator is preferably provided with a defoamer plate to eliminate bubbles. When the gas-liquid mixed phase stream flows through the defoamer plate, the bubbles burst, thereby separating the electrolyte solution and gas. As a result, vibration during electrolysis can be prevented.

[0517] (Baffle plate)

The baffle plate is preferably positioned above the anode side electrolyte solution supply unit and is positioned substantially parallel or obliquely with respect to the baffle 30. The baffle plate is a baffle plate that controls the flow of electrolyte solution into the anode chamber 10. When the baffle plate is provided, it can cause circulation electrolyte solution (brine or the like) inside the anode chamber 10, thereby making the concentration more uniform. To create internal circulation, the baffle plate is preferably positioned so as to separate the space near the anode 11 from the space near the baffle 30. For this reason, the baffle plate is preferably positioned so that it is opposite the surface of the anode 11 and the surface of the baffle 30. In the space near the anode separated by the baffle plate, electrolysis occurs, the concentration of the electrolyte solution (brine concentration) decreases, and a generated gas such as chlorine gas is released. This leads to a difference in the specific gravity of the gas-liquid mixture between the space near the anode 11 and the space near the dividing wall 30, separated by a baffle plate. Using this difference, it is possible to stimulate the internal circulation of the electrolyte solution in the anode chamber 10, thereby making the concentration distribution of the electrolyte solution in the anode chamber 10 more uniform.

[0518] Although not shown in Figure 63, a down conductor may also be additionally provided within the anode chamber 10. The material and configuration of such a current collector can be the same as for the aforementioned collector of the cathode chamber. In the anode chamber 10, the anode 11 itself can also serve as a down conductor.

[0519] (Divider)

The dividing wall 30 is disposed between the anode chamber 10 and the cathode chamber 20. The dividing wall 30 may be referred to as a separator, and the anode chamber 10 and the cathode chamber 20 are separated from each other by a dividing wall 30. As the dividing wall 30, a baffle known as a separator can be used. electrolysis, and an example thereof comprises a baffle formed by welding a nickel-containing plate on the cathode side and a titanium-containing plate on the anode side.

[0520] (Cathode Chamber)

In the cathode compartment 20, when the electrolysis electrode of the present embodiment is inserted on the cathode side, 21 serves as a cathode supply conductor. When the electrolysis electrode of the present embodiment is not inserted on the cathode side, 21 serves as the cathode. When a return current absorber is present, the cathode or cathode supply conductor 21 is electrically connected to the return current absorber. The cathode chamber 20, like the anode chamber 10, preferably has a cathode-side electrolyte solution supply unit and a cathode-side gas-liquid separator. Among the components constituting the cathode compartment 20, components similar to those constituting the anode compartment 10 will not be described.

[0521] (Cathode)

When the electrode for electrolysis of the present embodiment is not inserted on the cathode side, the cathode 21 is in the frame of the cathode chamber 20 (i.e., in the cathode frame). Cathode 21 preferably has a nickel substrate and a catalyst layer that covers the nickel substrate. Examples of catalyst bed components include elements such as Ru, C, Si, P, S, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Rh, Pd , Ag, Cd, In, Sn, Ta, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho , Er, Tm, Yb and Lu, as well as oxides and hydroxides of these metals. Examples of the method for forming the catalyst layer include electrodeposition, alloy electrodeposition, dispersion / composite electrodeposition, CVD, FOPP, pyrolysis, and sputtering. These methods can be used in combination. The catalyst bed can have multiple layers and multiple elements as needed. The cathode 21 can be subjected to a reduction treatment, if necessary. Nickel, nickel alloys and nickel-plated iron or stainless steel can be used as the substrate for the cathode 21.

As for the shape, any of a perforated metal sheet, a nonwoven fabric, a porous metal, an expanded metal sheet, an electrospinning metal porous foil, a so-called woven metal mesh formed by interlacing of thin metal filaments, and the like can be used.

[0522] (Cathode Supply Conductor)

When the electrode for electrolysis of the present embodiment is inserted on the cathode side, a cathode supply conductor 21 is provided in the frame of the cathode chamber 20. The cathode supply conductor 21 may be coated with a catalyst component. The catalyst component can be a component that is initially used as a cathode and is stored. Examples of catalyst bed components include elements such as Ru, C, Si, P, S, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Rh, Pd , Ag, Cd, In, Sn, Ta, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho , Er, Tm, Yb and Lu, as well as oxides and hydroxides of these metals. Examples of the method for forming the catalyst layer include electrodeposition, alloy electrodeposition, dispersion / composite electrodeposition, CVD, FOPP, pyrolysis, and sputtering. These methods can be used in combination. The catalyst bed can have multiple layers and multiple elements as needed. Nickel, nickel alloys and nickel-plated iron or stainless steel without catalytic coating can be used. Nickel, nickel alloys and nickel-plated iron or stainless steel can be used as the substrate for the cathode supply conductor 21.

As for the shape, any of a perforated metal sheet, a nonwoven fabric, a porous metal, an expanded metal sheet, an electrospinning metal porous foil, a so-called woven metal mesh formed by interlacing of thin metal filaments, and the like can be used.

[0523] (Reverse current absorbing layer)

As the material for the layer that absorbs the reverse current, a material that is less noble in terms of the redox potential than the redox potential of the element for the aforementioned catalyst layer of the cathode can be selected. Examples include nickel and iron.

[0524] (Down conductor)

The cathode chamber 20 preferably contains a current collector 23. The current collector 23 improves the efficiency of current extraction. In the present embodiment, the collector 23 is a porous plate and is preferably disposed substantially parallel to the surface of the cathode 21.

[0525] The collector 23 preferably contains an electrically conductive metal such as nickel, iron, copper, silver and titanium. The current collector 23 can be a mixture, alloy or complex oxide of these metals. The collector 23 may be of any shape as long as the shape allows the collector to function and may be in the form of a plate or mesh.

[0526] (Metallic elastic body)

By placing the metal elastic body 22 between the current collector 23 and the cathode 21, each cathode 21 of a plurality of electrolytic cells 1 connected in series is pressed against the ion exchange membrane 2 to shorten the distance between each anode 11 and each cathode 21. Thus, it is possible to reduce the voltage applied to the entire plurality of electrolytic cells connected in series. cells 1. Reducing voltage helps to reduce power consumption. When the metal resilient body 22 is placed, the pressing pressure created by the metal resilient body 22 allows the electrolysis electrode to stably maintain its position in place when the laminated article containing the electrolysis electrode of the present embodiment is placed in the electrolytic cell.

[0527] As the metal resilient body 22, spring members such as coil and coil springs and shock absorbing mats can be used. As the metal elastic body 22, an element can be appropriately applied in consideration of mechanical stress due to pressure on the ion exchange membrane and the like. The metal resilient body 22 may be located on the surface of the collector 23 on the side of the cathode chamber 20, or may be provided on the surface of the partition wall on the side of the anode chamber 10. The two chambers are usually separated so that the cathode chamber 20 becomes smaller than the anode chamber 10. Thus In terms of frame strength and the like, the metal resilient body 22 is preferably placed between the collector 34 and the cathode 21 in the cathode chamber 20. The metal resilient body 22 preferably contains an electrically conductive metal such as nickel, iron, copper, silver and titanium.

[0528] (Holder)

The cathode chamber 20 preferably comprises a holder 24 which electrically connects the collector 23 to the baffle 30. This can achieve an efficient current flow.

[0529] The holder 24 preferably contains an electrically conductive metal such as nickel, iron, copper, silver, and titanium. The holder 24 can be of any shape as long as the holder can support the collector 23 and can be in the form of a rod, plate, or mesh. The holder 24 is in the form of a plate, for example. A plurality of holders 24 are disposed between the baffle 30 and the down conductor 23. The plurality of holders 24 are aligned so that their surfaces are parallel to each other. The holders 24 are located substantially perpendicular to the baffle 30 and the down conductor 23.

[0530] (Anode side seal and cathode side seal)

The anode side seal is preferably located on the surface of the frame constituting the anode chamber 10. The cathode side seal is preferably positioned on the surface of the frame constituting the cathode chamber 20. The electrolytic cells are interconnected such that the anode side seal in one electrolytic cell and the cathode side seal an adjacent electrolytic cell is layered with a laminated article 25 (see Figure 64B). These seals can create airtightness at the junctions when a plurality of electrolytic cells 1 are connected in series through the laminate 25.

[0531] The seals form a seal between the ion exchange membrane and the electrolytic cells. Specific examples of seals include picture frame-like rubber sheets in the center of which an opening is formed. The seals must be resistant to corrosive electrolyte solutions or generated gas and be functional for a long period of time. Thus, with regard to chemical resistance and hardness, vulcanized products and peroxide-crosslinked products of ethylene-propylene-diene rubber (EPDM-rubber) and ethylene-propylene rubber (EPM-rubber) are usually used as seals. Alternatively, if necessary, seals can be used in which the area in contact with the liquid (the area in contact with the liquid) is coated with a fluorine resin such as polytetrafluoroethylene (PTFE) and copolymers of tetrafluoroethylene and perfluoroalkyl vinyl ethers (PFA). These seals may in each case have an opening that does not impede the flow of the electrolyte solution, and the shape of the opening is not particularly limited. For example, a seal in the form of a picture frame is attached by means of an adhesive or the like along the peripheral edge of each opening of the anode chamber frame constituting the anode chamber 10 or the cathode chamber frame constituting the cathode chamber 20. The interposition of the laminated article 25 between the anode seal and the cathode seal can prevent leakage from electrolytic cells 1 of electrolyte solution, alkali metal hydroxide, chlorine gas, hydrogen gas and the like generated by electrolysis.

[0532] [Laminated Product]

The laminated article of the present embodiment comprises a membrane and an electrolysis electrode. The laminated article in the present embodiment can improve the working efficiency during the renewal of the electrode in the electrolytic cell, and furthermore exhibits excellent electrolysis performance even after the renewal. That is, according to the layered article in the present embodiment, when the electrode is renewed, the electrode can be renewed as simple as renewing the membrane without complicated work such as disassembling an existing electrode attached to the electrolytic cell, and thereby noticeably improve the working efficiency.

In addition, according to the laminated article in the present embodiment, it is possible to maintain the electrolysis productivity with the existing electrolytic cell in comparison with the performance of the new electrode, or improve the electrolysis productivity. Thus, an electrode attached to an existing electrolytic cell and serving as anode and / or cathode should only act as a supply conductor. Thus, appreciable reduction or elimination of the catalytic coating can also be possible.

[0533] [Electrolysis Electrode]

In the electrolysis electrode of the present embodiment, the ventilation resistance measured at a temperature of 24 ° C, a relative humidity of 32%, a piston speed of 0.2 cm / s, and a ventilation volume of 0.4 cm ³ / cm ² / s (hereinafter also referred to as "Measurement condition 1") is 24 kPa · s / m or less when the electrolysis electrode has a size of 50 mm × 50 mm (hereinafter also referred to as "ventilation resistance 1""). A high ventilation resistance means that the air flows with more difficulty and belongs to a high density state. In this state, the electrolysis product remains in the electrode, and the reagents diffuse more into the electrode interior with greater difficulty, thereby deteriorating the electrolysis operating parameters (such as voltage). The concentration on the membrane surface increases. More specifically, the concentration of caustic soda increases at the surface of the cathode, and the supply of brine to the surface of the anode tends to decrease. As a result, the product accumulates to a high concentration at the interface where the membrane contacts the electrode. This build-up leads to damage to the membrane, and also causes an increase in electrical voltage and damage to the membrane at the cathode surface and damage to the membrane at the anode surface. In the present embodiment, in order to prevent these defects, the ventilation resistance is preferably controlled to 24 kPa · s / m or less.

In the present embodiment, when the ventilation resistance is higher than a certain value, NaOH evolved at the electrode tends to accumulate at the interface between the electrode and the membrane, resulting in a high concentration in the case of the cathode, and the brine supply tends to be reduced, causing the brine concentration to decrease. case of the anode. To prevent damage to the membrane that can be caused by such accumulation, the ventilation resistance is preferably less than 0.19 kPa s / m, more preferably 0.15 kPa s / m or less, even more preferably 0.07 kPa s / m or less.

In contrast, when the ventilation resistance is low, the electrode area is reduced and the conductive area is reduced. Thus, the operating parameters of the electrolysis (such as voltage) are deteriorated. When the ventilation resistance becomes zero, the supply conductor acts as an electrode since no electrode for electrolysis is provided, and the electrolysis operating parameters (such as voltage) deteriorate markedly. From this point of view, the preferable lower limit value identified as ventilation resistance 1 is not particularly limited, but is preferably more than 0 kPa s / m, more preferably 0.0001 kPa s / m or more, even more preferably 0.001 kPa s / m or more.

When the ventilation resistance 1 is 0.07 kPa · s / m or less, sufficient measurement accuracy may not be achieved by the measurement method used. From this point of view, it is also possible to evaluate an electrolysis electrode having a ventilation resistance 1 of 0.07 kPa · s / m or less using a ventilation resistance (hereinafter also referred to as "ventilation resistance 2") obtained by the following measurement method ( hereinafter also referred to as "measurement condition 2"). That is, the ventilation resistance 2 is the ventilation resistance measured when the electrolysis electrode has a size of 50 mm × 50 mm, under conditions of a temperature of 24 ° C, a relative humidity of 32%, a piston speed of 2 cm / s and a ventilation volume of 4 cm ³ / cm. ² / s.

Specific methods for measuring ventilation resistances 1 and 2 are described in Examples.

Ventilation resistances 1 and 2 can be within the above-described range by appropriately adjusting, for example, open porosity ratio, electrode thickness, and the like. More specifically, for example, when the thickness is constant, a higher open porosity ratio tends to lead to lower ventilation resistance values 1 and 2, and a lower open porosity ratio leads to higher ventilation resistance values 1 and 2.

[0534] The electrode for electrolysis of the present embodiment has a force applied per unit mass · unit area, preferably 1.6 N / (mg · cm ² ) or less, more preferably less than 1.6 N / (mg · cm ² ) , further preferably less than 1.5 N / (mg cm ² ), even more preferably 1.2 N / (mg cm ² ) or less, even more preferably 1.20 N / (mg cm ² ) or less with from the point of view of providing good workability and good adhesion to a membrane such as an ion exchange membrane and a microporous membrane, with a supply conductor (a worn electrode and an electrode not having a catalytic coating) and the like. The applied force is even more preferably 1.1 N / (mg cm ² ) or less, further more preferably 1.10 N / (mg cm ² ) or less, even more preferably 1.0 N / (mg cm ²⁾ ) or less, even more preferably 1.00 N / (mg · cm ² ) or less.

From the viewpoint of further improving the electrolysis productivity, the force is preferably more than 0.005 N / (mg cm ² ), more preferably 0.08 N / (mg cm ² ) or more, further preferably 0.1 N / (mg cm ² ) or more, even more preferably 0.14 N / (mg · cm ² ) or more. Even more preferably, the force is 0.2 N / (mg · cm ² ) or more from the viewpoint of further facilitating the handling of a large size (eg, 1.5 mx 2.5 m).

The above-described applied force may be within the above-described range by appropriately adjusting, for example, the below-described open porosity ratio, electrode thickness, arithmetic mean of surface roughness, and the like. For example, more specifically, a higher open porosity ratio results in a lower applied force, and a lower open porosity ratio results in a higher applied force.

The mass per unit area is preferably 48 mg / cm ² or less, more preferably 30 mg / cm ² or less, even more preferably 20 mg / cm ² or less from the standpoint of providing good processability and good adhesion to the membrane, such as an ion exchange membrane and a microporous membrane, with a worn electrode, with a feed conductor not having a catalytic coating, and economy, and moreover, is preferably 15 mg / cm ² or less, for general reasons including manufacturability, adhesion strength and economy. The lower limit is not particularly limited, but is, for example, on the order of 1 mg / cm ² .

The above-described mass per unit area may be within the above-described range, for example, by appropriately adjusting the below-described open porosity ratio, electrode thickness, and the like. More specifically, for example, when the thickness is constant, a higher open porosity ratio results in a decrease in mass per unit area, and a lower open porosity ratio results in a higher mass per unit area.

[0535] The applied force can be measured by methods (i) or (ii) described below, which are set out in more detail in the Examples. With regard to the applied force, the value obtained by measurement by method (i) (also called “applied force (1)” ") and the value obtained by measurement by method (ii) (also called" applied force (2) ”") , can be the same or different, and each of the values is preferably less than 1.5 N / (mg · cm ² ).

[0536] [Method (i)]

Nickel plate blasted with alumina 320 grit (thickness 1.2 mm, square with side 200 mm), ion-exchange membrane obtained by applying particles of inorganic material and a binder to both surfaces of a perfluorocarbon polymer into which an ion-exchange group is introduced (square with a side of 170 mm, the details of the ion exchange membrane specified here are described in the Examples), and a sample electrode (square with a side of 130 mm) is layered in that order. Thereafter, the laminated product is sufficiently immersed in clean water, and excess water deposited on the surface of the laminated product is removed to obtain a sample for measurement. The arithmetic mean (Ra) of the surface roughness of a nickel plate after blasting is 0.5 to 0.8 μm. A specific method for calculating the arithmetic mean (Ra) of the surface roughness is as described in the Examples.

Under the condition of temperature 23 ± 2 ° C and relative humidity 30 ± 5%, only the electrode sample in this measurement sample is lifted in the vertical direction at a speed of 10 mm / minute using a tensile compression machine and the load is measured when the electrode sample is lifted 10 mm vertically. This measurement is repeated three times and the average is calculated.

This average value is divided by the area of the overlapping area of the electrode sample and the ion exchange membrane and by the mass of the ion exchange membrane in the area of overlapping with the electrode sample to calculate the applied force per unit mass · unit area (1) (N / (mg · cm ² )).

[0537] The applied force per unit mass · unit area (1) obtained by method (i) is preferably 1.6 N / (mg · cm ² ) or less, more preferably less than 1.6 N / (mg · cm ² ), further preferably less than 1.5 N / (mg cm ² ), even more preferably 1.2 N / (mg cm ² ) or less, even more preferably 1.20 N / (mg cm ² ) or less in terms of providing good processability and good adhesion to a membrane such as an ion exchange membrane or a microporous membrane, a worn electrode, and an uncatalyzed supply conductor. The applied force is even more preferably 1.1 N / (mg cm ² ) or less, further more preferably 1.10 N / (mg cm ² ) or less, particularly preferably 1.0 N / (mg cm ² ) or less, particularly preferably 1.00 N / (mg · cm ² ) or less. The force is preferably more than 0.005 N / (mg cm ² ), more preferably 0.08 N / (mg cm ² ) or more, further preferably 0.1 N / (mg cm ² ) or more in view of further improvement electrolysis productivity, and, moreover, more preferably 0.14 N / (mg cm ² ), even more preferably 0.2 N / (mg cm ² ) or more from the standpoint of further facilitating handling of loading and unloading at a large size (for example, size 1.5 mx 2.5 m).

[0538] [Method (ii)]

A nickel plate blasted with alumina 320 grit (thickness 1.2 mm, square with a side of 200 mm, a nickel plate similar to the plate in the above method (i)), and an electrode sample (square with a side of 130 mm) is layered in this okay. Thereafter, the laminated product is sufficiently immersed in clean water, and excess water deposited on the surface of the laminated product is removed to obtain a sample for measurement. Under the condition of temperature 23 ± 2 ° C and relative humidity 30 ± 5%, only the electrode sample in this measurement sample is lifted in the vertical direction at a speed of 10 mm / minute using a tensile compression machine and the load is measured when the electrode sample is lifted 10 mm vertically. This measurement is repeated three times and the average is calculated.

This average value is divided by the area of the overlapping area of the electrode sample and the nickel plate and by the weight of the electrode sample in the overlapping area with the nickel plate to calculate the applied force per unit mass · unit area (2) (N / (mg · cm ² )).

[0539] The applied force per unit mass · unit area (2) obtained by method (ii) is preferably 1.6 N / (mg · cm ² ) or less, more preferably less than 1.6 N / (mg · cm ² ), further preferably less than 1.5 N / (mg cm ² ), even more preferably 1.2 N / (mg cm ² ) or less, even more preferably 1.20 N / (mg cm ² ) or less in terms of providing good processability and good adhesion to a membrane such as an ion exchange membrane or a microporous membrane, a worn electrode, and an uncatalyzed supply conductor. The applied force is even more preferably 1.1 N / (mg cm ² ) or less, further more preferably 1.10 N / (mg cm ² ) or less, particularly preferably 1.0 N / (mg cm ² ) or less, particularly preferably 1.00 N / (mg · cm ² ) or less. In addition, the force is preferably more than 0.005 N / (mg cm ² ), more preferably 0.08 N / (mg cm ² ) or more, further preferably 0.1 N / (mg cm ² ) or more from the point in terms of further improving the productivity of electrolysis, and, moreover, more preferably is 0.14 N / (mg cm ² ) from the position of further facilitating the handling of a large size (for example, size 1.5 m × 2.5 m) ...

[0540] The electrolysis electrode of the present embodiment preferably comprises an electrolysis electrode support and a catalyst layer. The thickness of the electrode substrate for electrolysis (measured thickness) is, but is not particularly limited, preferably 300 µm or less, more preferably 205 µm or less, even more preferably 155 µm or less, further preferably 135 µm or less, even more preferably 125 µm or less, even more preferably 120 μm or less, even more preferably 100 μm or less from the point of view of ensuring good processability, achieving good adhesion to a membrane such as an ion exchange membrane or a microporous membrane, with a worn electrode (supply conductor) and an electrode ( feed conductor), which does not have a catalytic coating, being suitable for roll-up and satisfactory folding into folds and facilitates loading and unloading at a large size (for example, size 1.5 mx 2.5 m), and, in addition, still more preferably 50 µm or less in terms of processability and economy. The lower limit is not particularly limited, but is, for example, 1 µm, preferably 5 µm, more preferably 15 µm.

[0541] The proportion measured by the following method (2) on the electrode for electrolysis in the present embodiment is not particularly limited, but is preferably 90% or more, more preferably 92% or more from the viewpoint of ensuring good workability and achieving good adhesion strength with membrane, such as an ion exchange membrane or a microporous membrane, with a worn electrode (supply conductor) and an electrode (supply conductor) not having a catalytic coating, and additionally preferably 95% or more from the point of view of further facilitating loading and unloading at a large size (for example , size 1.5 m × 2.5 m). The upper limit value is 100%.

[Method (2)]

An ion exchange membrane (170 mm square) and an electrode sample (130 mm square) are layered in this order. The laminated product is placed on the curved surface of a polyethylene pipe (outer diameter: 280 mm) so that the electrode sample in this laminated product is positioned outside at a temperature of 23 ± 2 ° C and a relative humidity of 30 ± 5%, the laminated product and the pipe are sufficiently immersed into clean water, remove the excess water deposited on the surface of the laminated product and the pipe, and then, one minute after this removal, measure the fraction (%) of the area of the area in which the ion-exchange membrane (square with a side of 170 mm) is in close contact with electrode.

[0542] The proportion measured by the following method (3) on the electrode for electrolysis in the present embodiment is not particularly limited, but is preferably 75% or more, more preferably 80% or more from the viewpoint of ensuring good workability, achieving good adhesion strength with membrane, such as an ion exchange membrane or a microporous membrane, with a worn electrode (supply conductor) and an electrode (supply conductor) not having a catalytic coating, and for proper roll-winding and satisfactory creasing, and is additionally preferably 90% or more from the point of view of additional facilitation of loading and unloading at a large size (for example, size 1.5 m × 2.5 m). The upper limit value is 100%.

[Method (3)]

An ion exchange membrane (170 mm square) and an electrode sample (130 mm square) are layered in this order. The laminated product is placed on the curved surface of a polyethylene pipe (outer diameter: 145 mm) so that the electrode sample in this laminated product is positioned externally at a temperature of 23 ± 2 ° C and a relative humidity of 30 ± 5%, the laminated product and the pipe are sufficiently immersed into clean water, remove the excess water deposited on the surface of the laminated product and the pipe, and then, one minute after this removal, measure the fraction (%) of the area of the area in which the ion-exchange membrane (square with a side of 170 mm) is in close contact with electrode.

[0543] The value obtained by measuring by the following method (A) of the electrode for electrolysis in the present embodiment is preferably 40 mm or less, more preferably 29 mm or less, even more preferably 19 mm or less in terms of processability.

[Method (A)]

At a temperature of 23 ± 2 ° C and a relative humidity of 30 ± 5%, a sample obtained by layering an ion-exchange membrane, which is obtained by applying particles of an inorganic material and a binder to both surfaces of the membrane made of a perfluorocarbon polymer into which an ion-exchange group is introduced (square with a side of 170 mm, the details of the ion exchange membrane specified herein are described in Examples) and the electrolysis electrode is wound around and fixed on the curved surface of a sleeve made of polyvinyl chloride having an outer diameter φ 32 mm and left standing for 6 hours; thereafter, when the electrolysis electrode is separated from the sample and placed on the flat plate, the heights L1 and L2 in the vertical direction at both edges of the electrolysis electrode are measured, and their average value is used as the measurement value.

[0544] The electrode for electrolysis in the present embodiment has a porous structure and an open porosity ratio or void ratio of 5 to 90% or less from the viewpoint of ensuring good processability, achieving good adhesion to a membrane such as an ion exchange membrane or a microporous membrane, with a worn electrode (supply conductor) and an electrode (supply conductor) not having a catalytic coating, and preventing the accumulation of gas evolved during electrolysis, although not specifically limited thereto. The open porosity ratio is more preferably 10 to 80% or less, more preferably 20 to 75%.

The open porosity ratio is the fraction of the lumen areas per unit volume. The calculation method may differ depending on whether sub-micron-sized gaps are considered or only visible gaps are considered. In the present embodiment, the volume V was calculated from the values of the measured thickness, the width and the length of the electrode, and in addition, the weight W was measured to thereby calculate the open porosity coefficient A by the following formula.

A = (1– (W / (V × ρ)) × 100

ρ is the density of the electrode material (g / cm ³ ). For example, the ρ of nickel is 8.908 g / cm ³ and the ρ of titanium is 4.506 g / cm ³ . The open porosity ratio is appropriately controlled by changing the area of perforated metal per unit area in the case of a perforated metal sheet, changing the values of SW (short diameter), LW (long diameter), and feed in the case of expanded metal sheet, changing the linear dimensions of the diameter of the metal fiber, and sieve numbers in the case of a mesh, a change in the photoresist pattern used in the case of electrospinning, a change in the diameter of the metal fiber and the density of the fiber in the case of a nonwoven fabric, a change in the mold for forming cavities in the case of a porous metal, or the like.

[0545] Hereinafter, one aspect of the electrode for electrolysis in the present embodiment will be described.

The electrolysis electrode of the present embodiment preferably comprises an electrolysis electrode support and a catalyst layer. The catalyst bed can be composed of multiple layers, as shown below, or can have a single layer configuration.

As shown in FIG. 68, the electrolysis electrode 100 of the present embodiment includes an electrolysis electrode substrate 10 and a pair of first layers 20 that cover both surfaces of the electrolysis electrode substrate 10. The first layers 20 preferably cover the entire electrode substrate 10 for electrolysis. Apparently, this coating increases the catalytic activity and durability of the electrode. One first layer 20 can only be laminated to one surface of the electrolysis electrode substrate 10.

In addition, as shown in Figure 68, the surfaces of the first layers 20 may be coated with the second layers 30. The first layers 20 are preferably covered with the second layers 30 in their entirety. Alternatively, one second layer 30 may be laminated to only one surface of the first layer 20.

[0546] (Electrode support for electrolysis)

As the electrode substrate 10 for electrolysis, for example, nickel, nickel alloys, stainless steel, and, in addition, valve metals, including titanium, can be used, although not limited thereto. Substrate 10 preferably contains at least one element selected from nickel (Ni) and titanium (Ti).

When stainless steel is used in an aqueous alkali solution of high concentration, iron and chromium are washed out and the electrical conductivity is in the order of one tenth that of nickel. In view of the above, as the electrode substrate for electrolysis, a substrate containing nickel (Ni) is preferable.

Alternatively, when the electrode substrate 10 for electrolysis is used in a brine with a high concentration close to saturation, in an atmosphere in which chlorine gas is generated, the material of the electrode substrate 10 is also preferably titanium having high corrosion resistance.

The shape of the electrode substrate 10 for electrolysis is not particularly limited, and a shape suitable for this purpose can be selected. As the mold, any of a perforated metal sheet, a nonwoven fabric, a porous metal, an expanded metal sheet, an electrospinning metal porous foil, a so-called woven metal mesh, and the like can be used. Of these, perforated metal sheet or expanded metal sheet is preferable. Electrospinning is a method of producing a thin metal foil having a precisely shaped pattern using photolithography and electrodeposition in combination. It is a method involving patterning a substrate with a photoresist and electrodeposition of a portion not protected by the resist to form a metal thin film.

With regard to the shape of the electrode support for electrolysis, a suitable specification depends on the distance between the anode and the cathode in the electrolysis cell. In the case where the distance between the anode and the cathode is finite, the shape of an expanded metal sheet or a perforated metal sheet can be used, and in the case of a so-called zero-gap electrolyzer in which the ion exchange membrane is in contact with the electrode, a formed interlacing of fine metal filaments woven metal mesh, wire mesh, porous metal, metal nonwoven fabric, expanded metal sheet, perforated metal sheet, metal porous foil, and the like, although not limited thereto.

Examples of the electrode substrate 10 for electrolysis include metal porous foil, wire mesh, metal nonwoven fabric, perforated metal sheet, expanded metal sheet, and porous metal.

As the plate material before being processed to form a perforated metal sheet or expanded metal sheet, rolled plate materials and electrolytic foils are preferred. The electrolytic foil is preferably subjected to a further electrodeposition treatment using the same element as its base material as a further treatment to thereby form roughness on one or both of its surfaces.

The thickness of the electrolysis electrode substrate 10 as mentioned above is preferably 300 µm or less, more preferably 205 µm or less, further preferably 155 µm or less, even more preferably 135 µm or less, even more preferably 125 µm or less, even more preferably 120 µm or less, even more preferably 100 µm or less, and further even more preferably 50 µm or less in terms of processability and economy. The lower limit is not particularly limited, but is, for example, 1 µm, preferably 5 µm, more preferably 15 µm.

[0547] In the electrolysis electrode substrate, residual stress during processing is preferably relieved by annealing the electrolysis electrode substrate in an oxidizing atmosphere. It is preferable to form roughness using a steel grid, an alumina grid or the like on the surface of the electrode substrate for electrolysis, followed by acid treatment to increase its surface area in order to improve adhesion to the catalyst layer that is coated on the surface. Alternatively, it is preferable to carry out the electrodeposition treatment using the same element as the substrate to increase the surface area.

[0548] To bring the first layer 20 into intimate contact with the surface of the electrolysis electrode substrate 10, the electrolysis electrode substrate 10 is preferably subjected to a surface area increase treatment. Examples of surface area enhancing treatments include chopped wire blasting, steel grating, alumina grating or the like, acidizing using sulfuric acid or hydrochloric acid, and electrodeposition using the same element as in the substrate. The arithmetic mean (Ra) of the surface roughness on the surface of the substrate is not particularly limited, but is preferably 0.05 µm to 50 µm, more preferably 0.1 to 10 µm, even more preferably 0.1 to 8 µm.

[0549] Next, a case will be described where the electrolysis electrode of the present embodiment is used as an anode for conventional salt electrolysis.

(First layer)

In Figure 68, the first layer 20 contains at least one of ruthenium oxides, iridium oxides and titanium oxides as a catalyst layer. Examples of ruthenium oxide include RuO ₂ . Examples of iridium oxide include IrO ₂ . Examples of titanium oxide include TiO ₂ . The first layer 20 preferably contains two oxides: ruthenium oxide and titanium oxide, or three oxides: ruthenium oxide, iridium oxide and titanium oxide. This makes the first layer 20 more stable and further improves the adhesion to the second layer 30.

[0550] When the first layer 20 contains two oxides: ruthenium oxide and titanium oxide, the first layer 20 preferably contains from 1 to 9 moles, more preferably from 1 to 4 moles of titanium oxide, based on 1 mole of ruthenium oxide contained in the first layer 20 With the compositional ratio of the two oxides in this range, the electrolysis electrode 100 exhibits excellent resistance.

[0551] When the first layer 20 contains three oxides: ruthenium oxide, iridium oxide and titanium oxide, the first layer 20 preferably contains 0.2 to 3 moles, more preferably 0.3 to 2.5 moles of iridium oxide per 1 mol of ruthenium oxide contained in the first layer 20. The first layer 20 preferably contains from 0.3 to 8 moles, more preferably from 1 to 7 moles of titanium oxide, based on 1 mole of ruthenium oxide contained in the first layer 20. With a compositional ratio of three oxides in this range, the electrolysis electrode 100 exhibits excellent resistance.

[0552] When the first layer 20 contains at least two of ruthenium oxide, iridium oxide and titanium oxide, these oxides preferably form a solid solution. The formation of a solid solution of the oxides allows the electrolysis electrode 100 to exhibit excellent resistance.

[0553] In addition to the above-described compositions, oxides of various compositions can be used, provided that at least one of ruthenium oxide, iridium oxide, and titanium oxide is contained. For example, an oxide coating called DSA (R), which contains ruthenium, iridium, tantalum, niobium, titanium, tin, cobalt, manganese, platinum, and the like, can be used as the first layer 20.

[0554] The first layer 20 does not have to be a single layer and may include multiple layers. For example, the first layer 20 may include a three-oxide layer and a two-oxide layer. The thickness of the first layer 20 is preferably 0.05 to 10 µm, more preferably 0.1 to 8 µm.

[0555] (Second layer)

The second layer 30 preferably contains ruthenium and titanium. This makes it possible to further reduce the electrical overvoltage of chlorine immediately after electrolysis.

[0556] The second layer 30 preferably contains palladium oxide, a solid solution of palladium and platinum oxide, or an alloy of palladium and platinum. This makes it possible to further reduce the electrical overvoltage of chlorine immediately after electrolysis.

[0557] The thicker second layer 30 can maintain the electrolysis performance for a long period of time, but from the standpoint of economy, the thickness is preferably 0.05 to 3 µm.

[0558] Next, a situation will be described where the electrolysis electrode of the present embodiment is used as a cathode for conventional salt electrolysis.

(First layer)

Examples of the components of the first layer 20 as a catalyst layer include elements such as C, Si, P, S, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, In, Sn, Ta, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu, as well as metal oxides and hydroxides.

The first layer 20 may or may not contain at least one of platinum group metals, platinum group metal oxides, platinum group metal hydroxides, and platinum group metal containing alloys.

When the first layer 20 contains at least one of platinum group metals, platinum group metal oxides, platinum group metal hydroxides and alloys containing a platinum group metal, platinum group metals, platinum group metal oxides, platinum group metal hydroxides, and platinum metal containing alloys the groups preferably contain at least one platinum group metal from platinum, palladium, rhodium, ruthenium and iridium.

The platinum group metal is preferably platinum.

As the oxide of the platinum group metal, ruthenium oxide is preferably contained.

As the hydroxide of the platinum group metal, ruthenium hydroxide is preferably contained.

As an alloy of platinum group metals, an alloy of platinum with nickel, iron and cobalt is preferably included.

In addition, if necessary, an oxide or hydroxide of a lanthanide element is preferably contained as the second component. This allows the electrolysis electrode 100 to exhibit excellent resistance.

As the oxide or hydroxide of the lanthanide element, preferably at least one selected from lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium and dysprosium is contained.

In addition, if necessary, a transition metal oxide or hydroxide is preferably contained as the third component.

The addition of the third component allows the electrolysis electrode 100 to exhibit superior resistance and lower electrolysis voltage.

Examples of a preferred combination include only ruthenium, ruthenium + nickel, ruthenium + cerium, ruthenium + lanthanum, ruthenium + lanthanum + platinum, ruthenium + lanthanum + palladium, ruthenium + praseodymium, ruthenium + praseodymium + platinum, ruthenium + praseodymium + platinum + palladium, ruthenium + neodymium, ruthenium + neodymium + platinum, ruthenium + neodymium + manganese, ruthenium + neodymium + iron, ruthenium + neodymium + cobalt, ruthenium + neodymium + zinc, ruthenium + neodymium + gallium, ruthenium + neodymium + sulfur, ruthenium + neodymium + lead , ruthenium + neodymium + nickel, ruthenium + neodymium + copper, ruthenium + samarium, ruthenium + samarium + manganese, ruthenium + samarium + iron, ruthenium + samarium + cobalt, ruthenium + samarium + zinc, ruthenium + samarium + gallium, ruthenium + samarium + sulfur, ruthenium + samarium + lead, ruthenium + samarium + nickel, platinum + cerium, platinum + palladium + cerium, platinum + palladium + lanthanum + cerium, platinum + iridium, platinum + palladium, platinum + iridium + palladium, platinum + nickel + palladium, platinum + nickel + ruthenium, platinum and nickel alloys, platinum and cobalt alloys and platinum and iron alloys.

When platinum-group metals, platinum-group metal oxides, platinum-group metal hydroxides, and platinum-group metal-containing alloys are not contained, the main component of the catalyst is preferably the element nickel.

Preferably, at least one of nickel metal, nickel oxides and hydroxides is contained.

A transition metal can be added as a second component. As the second added component, at least one of titanium, tin, molybdenum, cobalt, manganese, iron, sulfur, zinc, copper and carbon is preferably contained.

Examples of a preferred combination include nickel + tin, nickel + titanium, nickel + molybdenum, and nickel + cobalt.

If necessary, an intermediate layer may be disposed between the first layer 20 and the electrolysis electrode substrate 10. By placing the intermediate layer, the resistance of the electrolysis electrode 100 can be improved.

Preferred as the intermediate layer are those which have an affinity for both the first layer 20 and the electrode substrate 10 for electrolysis. As the intermediate layer, preferred are nickel oxides, platinum group metals, platinum group metal oxides and platinum group metal hydroxides. The intermediate layer can be formed by applying and firing a solution containing the component that forms the intermediate layer. Alternatively, a surface oxide layer can also be formed by subjecting the substrate to heat treatment at a temperature of 300 to 600 ° C. in an air atmosphere. In addition, this layer can be formed by a known method such as a thermal spraying method and an ionic deposition method.

[0559] (Second layer)

Examples of the components of the first layer 30 as a catalyst layer include elements such as C, Si, P, S, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, In, Sn, Ta, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu, as well as metal oxides and hydroxides.

The first layer 30 may or may not contain at least one of platinum group metals, platinum group metal oxides, platinum group metal hydroxides, and platinum group metal containing alloys. Examples of a preferred combination of elements contained in the second layer include those listed for the first layer. The combination of the first layer and the second layer can be a combination in which the compositions are the same and the compositional ratios are different, or it can be a combination of different compositions.

With regard to the thickness of the catalyst layer, the total thickness of the formed catalyst layer and the intermediate layer is preferably 0.01 µm to 20 µm. With a thickness of 0.01 µm or more, the catalyst layer can sufficiently serve as a catalyst. With a thickness of 20 µm or less, a strong catalyst layer can be formed that is unlikely to separate from the support. The thickness is more preferably 0.05 µm to 15 µm. The thickness is more preferably 0.1 to 10 µm. Even more preferably, the thickness is 0.2 to 8 µm.

[0560] The thickness of the electrode, that is, the combined thickness of the electrolysis electrode support and the catalyst layer, is preferably 315 µm or less, more preferably 220 µm or less, further preferably 170 µm or less, even more preferably 150 µm or less, particularly preferably 145 µm or less, even more preferably 140 µm or less, even more preferably 138 µm or less, further even more preferably 135 µm or less, with respect to the workability of the electrode. A thickness of 135 µm or less can provide good workability. In addition, for similar reasons as above, the thickness is preferably 130 µm or less, more preferably less than 130 µm, even more preferably 115 µm or less, further more preferably 65 µm or less. The lower limit is not particularly limited, but is preferably 1 µm or more, more preferably 5 µm or more for practical reasons, more preferably 20 µm or more. The thickness of the electrode can be determined by measuring with a digital thickness gauge (from Mitutoyo Corporation, minimum scale 0.001 mm). The thickness of the substrate of the electrolysis electrode can be measured in the same manner as in the case of the electrode. The thickness of the catalyst layer can be determined by subtracting the thickness of the electrolysis electrode support from the thickness of the electrode.

[0561] In the present embodiment, the electrode for electrolysis preferably contains at least one catalyst component selected from the group consisting of Ru, Rh, Pd, Ir, Pt, Au, Ti, V, Cr, Mn, Fe, Co, Ni , Cu, Zn, Y, Zr, Nb, Mo, Ag, Ta, W, Re, Os, Al, In, Sn, Sb, Ga, Ge, B, C, N, O, Si, P, S, La , Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb and Dy, from the standpoint of achieving sufficient electrolysis performance.

[0562] In the present embodiment, from the considerations that the electrode for electrolysis of the present embodiment, if it is an electrode having a wide elastic deformation range, can provide better workability and has a better adhesion force to a membrane such as an ion exchange membrane or microporous membrane, with a worn electrode, with a supply conductor not having a catalytic coating, and the like, the thickness of the electrode for electrolysis is preferably 315 μm or less, more preferably 220 μm or less, even more preferably 170 μm or less, even more preferably 150 µm or less, particularly preferably 145 µm or less, even more preferably 140 µm or less, further still more preferably 138 µm or less, even more preferably 135 µm or less. A thickness of 135 µm or less can provide good workability. In addition, for reasons similar to the above, the thickness is preferably 130 µm or less, more preferably less than 130 µm, further preferably 115 µm or less, even more preferably 65 µm or less. The lower limit is not particularly limited, but is preferably 1 µm or more, more preferably 5 µm or more for practical reasons, more preferably 20 µm or more. In the present embodiment, “having a wide elastic range” means that when the electrolysis electrode is wound to form a winding, it is unlikely that winding-induced warping will occur after being released from the wound state. The thickness of the electrolysis electrode when the below-mentioned catalyst layer is provided refers to the total thickness of both the electrolysis electrode support and the catalyst layer.

[0563] (Method for Manufacturing Electrolysis Electrode)

Next, one embodiment of a method for manufacturing an electrode 100 for electrolysis will be described in detail.

In the present embodiment, the electrolysis electrode 100 can be obtained by forming a first layer 20, preferably a second layer 30 on the electrolysis electrode substrate by a method such as firing a coating film in an oxygen atmosphere (pyrolysis) or ion deposition, electrodeposition, or thermal sputtering. The production method of the present embodiment as mentioned above can achieve high formation productivity of the electrolysis electrode 100. More specifically, a catalyst layer is formed on the electrode support for electrolysis by an application step in which a coating liquid containing the catalyst is applied, a drying step in which the coating liquid is dried, and a pyrolysis step in which pyrolysis is performed. Pyrolysis here means that a metal salt, which is to be a precursor, decomposes by heating into a metal or metal oxide and a gaseous substance. The decomposition product depends on the nature of the metal used, the type of salt and the atmosphere in which the pyrolysis is carried out, and many metals tend to form oxides in an oxidizing atmosphere. In the industrial process for making an electrode, pyrolysis is usually performed in air and in many cases a metal oxide or metal hydroxide is formed.

[0564] (Formation of the first layer of the anode)

(Application stage)

The first layer 20 is obtained by applying a solution in which at least one metal salt of ruthenium, iridium and titanium (first coating liquid) is dissolved on the electrode substrate for electrolysis, and then pyrolysis (calcining) the coating liquid in the presence of oxygen. The content of ruthenium, iridium and titanium in the first cover liquid is substantially equivalent to that in the first layer 20.

[0565] Metal salts can be chlorides, nitrates, sulfates, metal alkoxides and any other forms. The solvent of the first coating liquid can be selected depending on the type of metal salt, and water and alcohols such as butanol can be used. As the solvent, water or a mixed solvent of water and alcohol is preferred. The total metal concentration in the first coating liquid in which the metal salts are dissolved is not particularly limited, but is preferably in the range of 10 to 150 g / L in consideration of the thickness of the coating film formed by a single application.

[0566] Examples of the method used as the method for applying the first coating liquid to the electrolysis electrode substrate 10 include a method for dipping the electrolysis electrode substrate 10 into the first coating liquid, a method for applying the first coating liquid with a brush, a rolling method using a sponge roller impregnated the first coating liquid, and an electrostatic coating method in which the electrode substrate 10 for electrolysis and the first coating liquid are charged with opposite charges and sputtering is performed. Among them, a rolling method or an electrostatic coating method is preferable, which has excellent production performance on an industrial scale.

[0567] (Drying step and pyrolysis step)

After applying the first coating liquid to the electrode substrate 100 for electrolysis, it is dried at a temperature of 10 to 90 ° C and subjected to pyrolysis in a roasting furnace heated to a temperature of 350 to 650 ° C. Between drying and pyrolysis, if necessary, a pre-firing can be performed at a temperature of 100 to 350 ° C. The temperature for drying, pre-firing and pyrolysis is appropriately selected depending on the composition and type of solvent of the first coating liquid. A longer period of pyrolysis time in each step is preferable, but from the viewpoint of productivity of producing an electrode, 3 to 60 minutes, more preferably 5 to 20 minutes are preferable.

[0568] The cycle of the above-described application, drying and pyrolysis is repeated to form a coating (first layer 20) to a predetermined thickness. After the first layer 20 is formed and then further post-baked for an extended period of time as required, this can further increase the stability of the first layer 20.

[0569] (Formation of the second layer)

The second layer 30, which is formed if necessary, is obtained, for example, by applying a solution containing a palladium compound and a platinum compound or a solution containing a ruthenium compound and a titanium compound (second coating liquid) on the first layer 20, and then the coating liquid is subjected to pyrolysis in presence of oxygen.

[0570]

(Formation of the first cathode layer by pyrolysis method)

(Application stage)

The first layer 20 is obtained by applying a solution in which metal salts in various combinations are dissolved (first coating liquid) on an electrode substrate for electrolysis, and then pyrolysis (calcining) the coating liquid in the presence of oxygen. The metal content in the first coating liquid is substantially equivalent to that in the first layer 20.

[0571] Metal salts can be chlorides, nitrates, sulfates, metal alkoxides and any other forms. The solvent of the first coating liquid can be selected depending on the type of metal salt, and water and alcohols such as butanol can be used. As the solvent, water or a mixed solvent of water and alcohol is preferred. The total metal concentration in the first coating liquid in which the metal salts are dissolved is not particularly limited, but is preferably in the range of 10 to 150 g / L in consideration of the thickness of the coating film formed by a single application.

[0572] Examples of the method used as the method for applying the first coating liquid to the electrolysis electrode substrate 10 include a method for dipping the electrolysis electrode substrate 10 into the first coating liquid, a method for applying the first coating liquid with a brush, a rolling method using a sponge roller impregnated the first coating liquid, and an electrostatic coating method in which the electrode substrate 10 for electrolysis and the first coating liquid are charged with opposite charges and sputtering is performed. Among them, a rolling method or an electrostatic coating method is preferable, which has excellent production performance on an industrial scale.

[0573] (Drying step and pyrolysis step)

After applying the first coating liquid to the electrode substrate 100 for electrolysis, it is dried at a temperature of 10 to 90 ° C and subjected to pyrolysis in a roasting furnace heated to a temperature of 350 to 650 ° C. Between drying and pyrolysis, if necessary, a pre-firing can be performed at a temperature of 100 to 350 ° C. The temperature for drying, pre-firing and pyrolysis is appropriately selected depending on the composition and type of solvent of the first coating liquid. A longer period of pyrolysis time in each step is preferable, but from the viewpoint of productivity of producing an electrode, 3 to 60 minutes, more preferably 5 to 20 minutes are preferable.

[0574] The cycle of the above-described application, drying and pyrolysis is repeated to form a coating (first layer 20) to a predetermined thickness. After the first layer 20 is formed and then further post-baked for an extended period of time as required, this can further increase the stability of the first layer 20.

[0575] (Interlayer formation)

The intermediate layer, which is formed, if necessary, is obtained, for example, by applying a solution containing a palladium compound or a platinum compound (second coating liquid) to a substrate, and then pyrolysis of the coating liquid in the presence of oxygen. Alternatively, the nickel oxide intermediate layer can be formed on the surface of the substrate by heating the substrate only, without applying a solution thereto.

[0576] (Formation of the first layer of the cathode by ion deposition)

The first layer 20 can also be formed by ion deposition.

The example comprises a method in which a substrate is fixed in a chamber and a ruthenium metal target is irradiated with an electron beam. Particles of vaporized metallic ruthenium are positively charged in the plasma in the chamber, deposited on a negatively charged substrate. The plasma atmosphere is argon and / or oxygen and ruthenium is deposited on the substrate as ruthenium oxide.

[0577] (Formation of the first layer of the cathode by electrodeposition)

The first layer 20 can also be formed by electrodeposition.

As an example, when the substrate is used as a cathode and is subjected to plating in an electrolyte solution containing nickel and tin, an electrolytic plating of a nickel-tin alloy can be formed.

[0578] (Formation of the first layer of the cathode by thermal spraying)

The first layer 20 can also be formed by thermal spraying.

By way of example, nickel oxide particles sprayed by plasma onto a substrate may form a catalyst bed in which nickel metal and nickel oxide are mixed.

[0579] The electrode for electrolysis of the present embodiment may be combined with a membrane such as an ion exchange membrane or a microporous membrane and used. Thus, the laminated article in the present embodiment can be applied as a membrane-integrated electrode. Then the work of replacing the cathode and anode is eliminated when renewing the electrode and the work efficiency is noticeably improved.

An electrode combined with a membrane, such as an ion exchange membrane and a microporous membrane, can make electrolysis performance comparable to or better than that with a new electrode.

[0580] Next, the ion exchange membrane will be described in detail.

[Ion exchange membrane]

The ion exchange membrane is not particularly limited as long as the membrane can be laminated with an electrolysis electrode and a variety of ion exchange membranes can be used. In the present embodiment, an ion exchange membrane is preferably used which has a membrane body containing a hydrocarbon polymer or a fluorine-containing polymer having an ion exchange group and a coating layer provided on at least one surface of the membrane body. It is preferable that the coating layer contains particles of inorganic material and a binder, and the specific surface area of the coating layer is 0.1 to 10 m ² / g. In an ion exchange membrane having such a structure, the effect of gas evolved during electrolysis on the electrolysis performance is small, and stable electrolysis performance can be demonstrated.

The above-described fluoropolymer ion exchange membrane into which an ion exchange group has been introduced contains one of either a sulfonic acid layer having an ion exchange group derived from a sulfo group (a group represented by —SO ₃ ^- , hereinafter also referred to as a “sulfonic acid group”), or a carboxylic acid layer having an ion exchange group derived from a carboxyl group (a group represented as —CO ₂ ^- , hereinafter also referred to as a “carboxylic acid group”). From the point of view of strength and dimensional stability, it is preferable to additionally include core reinforcing materials.

The inorganic material particles and the binder will be described in detail below in the coating layer description section.

[0581] Figure 69 illustrates a schematic sectional view showing one embodiment of an ion exchange membrane. The ion exchange membrane 1 has a membrane body 10 containing a hydrocarbon polymer or a fluorine-containing polymer having an ion exchange group, and coating layers 11a and 11b formed on both surfaces of the membrane body 10.

[0582] In the ion exchange membrane 1, the membrane body 10 includes a sulfonic acid layer 3 having an ion exchange group derived from a sulfo group (a group represented by —SO ₃ ^- , hereinafter also referred to as a “sulfonic acid group”), and a carboxylic acid layer 2, having an ion exchange group derived from a carboxyl group (a group represented by —CO ₂ ^- , hereinafter also referred to as a “carboxylic acid group”), and core reinforcing materials 4 that increase strength and dimensional stability. An ion exchange membrane 1 including a sulfonic acid layer 3 and a carboxylic acid layer 2 is suitably used as an anion exchange membrane.

[0583] The ion exchange membrane may include one of a sulfonic acid layer and a carboxylic acid layer. The ion exchange membrane does not need to be reinforced with core reinforcing materials, and the arrangement of the core reinforcing materials is not limited to the example in FIG. 69.

[0584] (Membrane Body)

First, the membrane body 10 constituting the ion exchange membrane 1 will be described.

The body 10 of the membrane should be such that its function is to provide selective permeation of cations, and contains a hydrocarbon polymer or a fluorine-containing polymer having an ion exchange group. Its configuration and material are not particularly limited, and preferable ones can be appropriately selected.

[0585] The hydrocarbon polymer or fluorine-containing polymer having an ion exchange group in the membrane body 10 can be obtained from a hydrocarbon polymer or a fluorine-containing polymer having an ion exchange group precursor capable of forming an ion exchange group by hydrolysis or the like. More specifically, for example, after a polymer comprising a fluorinated hydrocarbon backbone having a side chain that is converted to an ion exchange group by hydrolysis or the like (ion exchange group precursor) is used to obtain a precursor of the membrane body 10, and melt-processable ( below in some cases referred to as "fluoropolymer (s)" ""), the membrane body 10 can be obtained by converting a precursor of an ion exchange group into an ion exchange group.

[0586] The fluorine-containing polymer (s) can be obtained, for example, by copolymerizing at least one monomer selected from the next first group and at least one monomer selected from the next second group and / or the next third group. The fluorine-containing polymer (s) can also be obtained by homopolymerizing one monomer selected from any of the next first group, the next second group, and the next third group.

[0587] Examples of monomers of the first group include vinyl fluoride compounds. Examples of vinyl fluoride compounds include vinyl fluoride, tetrafluoroethylene, hexafluoropropylene, vinylidene fluoride, trifluoroethylene, chlorotrifluoroethylene, and perfluoroalkyl vinyl ethers. In particular, when an ion exchange membrane is used as a membrane for alkaline electrolysis, the vinyl fluoride compound is preferably a perfluorinated monomer, and a perfluorinated monomer selected from the group consisting of tetrafluoroethylene, hexafluoropropylene and perfluoroalkyl vinyl ethers is preferred.

[0588] Examples of monomers of the second group include vinyl compounds having a functional group convertible to an ion exchange group of the carboxylic acid type (carboxylic acid group). Examples of vinyl compounds having a functional group convertible to a carboxylic acid ion exchange group include monomers represented by the formula CF ₂ = CF (OCF ₂ CYF) _s –O (CZF) _t –COOR, in which s is an integer from 0 to 2, t is an integer from 1 to 12, each of Y and Z is independently F or CF ₃ and R is a lower alkyl group (a lower alkyl group is an alkyl group having, for example, 1 to 3 carbon atoms).

[0589] Among them, preferred are compounds represented by the formula CF ₂ = CF (OCF ₂ CYF) _n —O (CF ₂ ) _m —COOR, in which n represents an integer from 0 to 2, m represents an integer from 1 to 4, Y is F or CF ₃ and R is CH ₃ , C ₂ H ₅ or C ₃ H ₇ .

[0590] When an ion exchange membrane is used as a cation exchange membrane for alkaline electrolysis, the perfluoro compound is preferably used at least as a monomer, but the alkyl group (see R values above) of the ester group is lost from the polymer during hydrolysis, and therefore the alkyl group (R) is not must necessarily be a perfluoroalkyl group in which all hydrogen atoms are replaced by fluorine atoms.

[0591] Of the above monomers, the following monomers are more preferred as monomers of the second group:

CF ₂ = CFOCF ₂ –CF (CF ₃ ) OCF ₂ COOCH ₃ ,

CF ₂ = CFOCF ₂ CF (CF ₃ ) O (CF ₂ ) ₂ COOCH ₃ ,

CF ₂ = CF [OCF ₂ –CF (CF ₃ )] ₂ O (CF ₂ ) ₂ COOCH ₃ ,

CF ₂ = CFOCF ₂ CF (CF ₃ ) O (CF ₂ ) ₃ COOCH ₃ ,

CF ₂ = CFO (CF ₂ ) ₂ COOCH ₃ and

CF ₂ = CFO (CF ₂ ) ₃ COOCH ₃ .

[0592] Examples of monomers of the third group include vinyl compounds having a functional group convertible to an ion exchange group of the sulfone type (sulfonic acid group). As vinyl compounds having a functional group convertible to a sulfonic acid ion exchange group, for example, monomers represented by the formula CF ₂ = CFO — X — CF ₂ —SO ₂ F in which X is a perfluoroalkylene group are preferred. Specific examples include the following monomers:

CF ₂ = CFOCF ₂ CF ₂ SO ₂ F,

CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₂ F,

CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ CF ₂ SO ₂ F,

CF ₂ = CF (CF ₂ ) ₂ SO ₂ F,

CF ₂ = CFO [CF ₂ CF (CF ₃ ) O] ₂ CF ₂ CF ₂ SO ₂ F and

CF ₂ = CFOCF ₂ CF (CF ₂ OCF ₃ ) OCF ₂ CF ₂ SO ₂ F.

[0593] Among them, CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ CF ₂ SO ₂ F and CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₂ F are more preferable.

[0594] The copolymer obtained from these monomers can be formed by a polymerization process designed for homopolymerization and copolymerization of ethylene fluoride, in particular by a general polymerization process used for tetrafluoroethylene. For example, in a method using a non-aqueous medium, the polymerization reaction can be carried out in the presence of a free radical polymerization initiator such as a perfluorocarbon peroxide or an azo compound, under conditions of a temperature of 0 to 200 ° C and a pressure of 0.1 to 20 MPa, using an inert solvent, such as a perfluorocarbon or a chlorofluorocarbon.

[0595] In the above copolymerization, the type of combination of the above monomers and their proportions are not particularly limited and are determined depending on the type and amount of functional groups that it is desirable to introduce into the resulting fluorine-containing polymer. For example, when a fluorine-containing polymer containing only a carboxylic acid group is produced, at least one polymer must be selected from each of the above-described first group and second group and copolymerized. In addition, when a fluorine-containing polymer containing only a sulfonic acid group is prepared, at least one polymer must be selected from each of the first group and the third group, and copolymerized. In addition, when a fluorine-containing polymer having a carboxylic acid group and a sulfonic acid group is produced, at least one monomer must be selected from each of the above-described first group, second group and third group and copolymerized. In this case, the target fluorine-containing polymer can also be obtained by separately forming a copolymer including monomers of the above-described first group and second group, and a copolymer including monomers of the above-described first group and third group, and then mixing these copolymers. The composition of the mixture of monomers is not particularly limited, and when the number of functional groups per structural unit of the polymer increases, the proportion of monomers selected from the above-described second group and third group must increase.

[0596] The total ion exchange capacity of the fluorine-containing copolymer is not particularly limited, but is preferably 0.5 to 2.0 mg⋅eq / g, more preferably 0.6 to 1.5 mg⋅eq / g. The total ion exchange capacity here refers to the equivalent of the exchange group per unit weight of dry resin and can be measured by neutralization titration or the like.

[0597] In the membrane body 10 of the ion exchange membrane 1, a sulfonic acid layer 3 containing a fluorine-containing polymer having a sulfonic acid group and a carboxylic acid layer 2 containing a fluorine-containing polymer having a carboxylic acid group are laminated. By providing the membrane body 10 having such a layer configuration, the selective permeability to cations such as sodium ions can be further improved.

[0598] The ion exchange membrane 1 is placed in the electrolytic cell so that generally the sulfonic acid layer 3 is on the anode side of the cell and the carboxylic acid layer 2 is on the cathode side of the cell.

[0599] The sulfonic acid layer 3 is preferably composed of a material having a low electrical resistance and is thicker than the carboxylic acid layer 2 in terms of membrane strength. The thickness of the sulfonic acid layer 3 is preferably 2 to 25 times, more preferably 3 to 15 times the thickness of the carboxylic acid layer 2.

[0600] The carboxylic acid layer 2 preferably has high anion exclusion characteristics even if it is thin. The anion exclusion characteristics herein refer to the characteristic of hindering the incorporation and penetration of anions into or through the ion exchange membrane 1. In order to improve the anion exclusion characteristics, it is effective to place a carboxylic acid layer having a low ion exchange capacity compared to the sulfonic acid layer.

[0601] As the fluorine-containing polymer for use in the sulfonic acid layer 3, a polymer obtained using CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₂ F as the third group monomer is preferable.

[0602] As the fluorine-containing polymer for use in the carboxylic acid layer 2, a polymer obtained using CF ₂ = CFOCF ₂ CF (CF ₂ ) O (CF ₂ ) ₂ COOCH _{3 is} preferred as the monomer of the second group.

[0603]

(Coating layer)

The ion exchange membrane preferably has a coating layer on at least one surface of the membrane body. As shown in Figure 69, in the ion exchange membrane 1, coating layers 11a and 11b are formed on both surfaces of the membrane body 10.

The coating layers contain particles of inorganic material and a binder.

[0604] The average particle size of the inorganic material is preferably 0.90 µm or more. When the average particle size of the inorganic material is 0.90 µm or more, impurity resistance is greatly improved in addition to gas attachment. That is, by increasing the average particle size of the inorganic material as well as keeping the above-mentioned specific surface area, a particularly noticeable effect can be achieved. Uneven particles of inorganic material are preferred insofar as the above average particle size and specific surface area are satisfied. Melting inorganic material particles and raw ore milling inorganic material particles can be used. Preferably, particles of inorganic material obtained by milling raw ore are used.

[0605] The average particle size of the inorganic material may be 2 µm or less. When the average particle size of the inorganic material is 2 µm or less, damage to the membrane by the inorganic material can be prevented. The average particle size of the inorganic material is more preferably 0.90 to 1.2 µm.

[0606] Here, the average particle size can be measured by a particle size analyzer ("SALD2200", manufactured by SHIMADZU CORPORATION).

[0607] The particles of inorganic material are preferably irregular in shape. Such shapes further improve the resistance to impurities. The particles of inorganic material preferably have a wide particle size distribution.

[0608] The particles of inorganic material preferably contain at least one inorganic material selected from the group consisting of oxides of Group IV elements of the Periodic Table, nitrides of Group IV elements of the Periodic Table, and carbides of Group IV elements of the Periodic Table. From the standpoint of resistance, zirconium oxide particles are more preferable.

[0609] The inorganic material particles are preferably inorganic material particles obtained by grinding raw ore from inorganic material particles, or inorganic material particles in the form of spherical particles having a uniform diameter obtained by refining a raw ore melt from inorganic material particles.

[0610] Examples of means for grinding raw ore include, but are not specifically limited to, ball mills, bead mills, colloid mills, cone grinders, disk mills, runners, grain mills, hammer mills, granulators, vertical shaft impact crushers (VSI ), leather mills (Wiley mills), roller mills and jet mills. After grinding, the particles are preferably washed. As a washing method, the particles are preferably treated with an acid. This treatment can reduce the amount of impurities such as iron adhered to the surface of the inorganic material particles.

[0611] The coating layer preferably contains a binder. The binder is the component that forms the coating layers by retaining particles of inorganic material on the surface of the ion exchange membrane. The binder preferably contains a fluorine-containing polymer from the standpoint of resistance to electrolyte solution and electrolysis products.

[0612] As a binder, a fluorine-containing polymer having a carboxylic acid group or a sulfonic acid group is more preferable in terms of resistance to electrolyte solution and electrolysis products and adhesion strength to the surface of the ion exchange membrane. When the coating layer is provided on a layer containing a fluorine-containing polymer having a sulfonic acid group (sulfonic acid layer), the fluorine-containing polymer having a sulfonic acid group is even more preferably used as a binder for the coating layer. Alternatively, when the coating layer is provided on a layer containing a fluorine-containing polymer having a carboxylic acid group (carboxylic acid layer), a fluorine-containing polymer having a carboxylic acid group is more preferably used as a binder for the coating layer.

[0613] The content of the particles of inorganic material in the coating layer is preferably 40 to 90% by mass, more preferably 50 to 90% by mass. The content of the binder is preferably 10 to 60% by mass, more preferably 10 to 50% by mass.

[0614] The distribution density of the coating layer in the ion exchange membrane is preferably 0.05 to 2 mg per cm ² . When the ion exchange membrane has ridges (roughness) on its surface, the distribution density of the coating layer is preferably 0.5 to 2 mg per cm ² .

[0615] As a method for manufacturing the coating layer, which is not particularly limited, a known method can be applied. An example is a method comprising applying by spray or the like a coating liquid obtained by dispersing particles of an inorganic material in a solution containing a binder.

[0616] (Core Reinforcement Materials)

The ion exchange membrane preferably has core reinforcing materials disposed within the membrane body.

[0617] Reinforcing materials of the core are elements that increase the strength and dimensional stability of the ion exchange membrane. By placing the reinforcing materials of the core within the body of the membrane, it is possible, in particular, to control the expansion and contraction of the ion exchange membrane in the desired range. Such an ion exchange membrane does not expand or contract more than necessary during electrolysis and the like, and can maintain excellent dimensional stability for a long time.

[0618] The configuration of the core reinforcing materials is not particularly limited, and, for example, the core reinforcing materials may be formed by woven yarns called reinforcing yarns. Reinforcing yarns herein refer to yarns that constitute the constituent core reinforcing materials, can provide the desired dimensional stability and mechanical strength to the ion exchange membrane, and can be stably present in the ion exchange membrane. By using core reinforcing materials obtained by weaving such reinforcing yarns, better dimensional stability and mechanical strength can be imparted to the ion exchange membrane.

[0619] The material of the reinforcing materials of the core and the reinforcing yarns used therefor is not particularly limited, but is preferably a material resistant to acids, alkalis, etc., and a fiber including a fluorine-containing polymer is preferable since long-term heat resistance and chemical resistance are required. ...

[0620] Examples of the fluoropolymer used in core reinforcing materials include polytetrafluoroethylene (PTFE), copolymers of tetrafluoroethylene and perfluoroalkyl vinyl ether (PFA), copolymers of tetrafluoroethylene and ethylene (ETFE), copolymers of tetrafluoroethylene copolymers and copolymers of tetrafluoroethylene copolymers and copolymers of tetrafluoroethylene copolymers PVDF). Among them, fibers including polytetrafluoroethylene are preferably used in terms of heat resistance and chemical resistance.

[0621] The diameter of the reinforcing yarns used for the core reinforcing materials is not particularly limited, but is preferably 20 to 300 denier, more preferably 50 to 250 denier. The weave density (web density per unit length) is preferably 5 to 50 / inch. The shape of the core reinforcing materials is not particularly limited, for example, woven fabric, non-woven fabric and knitted fabric are used, but preferably in the form of woven fabric. The thickness of the woven fabric used is preferably 30 to 250 µm, more preferably 30 to 150 µm.

[0622] As the woven fabric or knitted fabric, monofilaments, multifilaments or yarns thereof, twisted yarns with dangling yarns or the like can be used, and various types of weaving methods can be used such as plain weaving, leno weaving, knitted weaving, cord weave and crinkled chintz (seersucker).

[0623] The braiding and placement of the core reinforcing materials in the membrane body are not particularly limited, and the preferred placement can be appropriately provided in consideration of the size and shape of the ion exchange membrane, physical properties desired for the ion exchange membrane, environmental conditions in use, and the like.

[0624] For example, the core reinforcing materials may be placed along a predetermined direction of the membrane body, but from a dimensional stability point of view, it is preferable that the core reinforcing materials are placed along a predetermined first direction and other core reinforcing materials are placed along a predetermined second direction along essentially perpendicular to the first direction. By placing multiple core reinforcement materials substantially orthogonal within the membrane body, better dimensional stability and mechanical strength in many directions can be imparted. For example, a configuration is preferable in which core reinforcing materials disposed along the longitudinal direction (warp yarns) and core reinforcing materials disposed along the transverse direction (weft yarns) are woven on the surface side of the membrane body. A more preferred configuration is in the form of a plain weave, made and woven by allowing the warp and weft yarns to pass alternately above and below each other, a leno weave in which two base strands are woven into the weft strands in a twist, a matting weave made and woven by inserting the same number of weft yarns or the like into two or more parallel warp yarns, or the like, from the standpoint of dimensional stability, mechanical strength and ease of manufacture.

[0625] It is particularly preferable that the core reinforcing materials are disposed along both directions MD (longitudinal direction) and TD (transverse direction) of the ion exchange membrane. In other words, the core reinforcing materials are preferably plain weave in MD and TD. Here, MD means the direction in which the membrane body and various core materials (for example, reinforcing core materials, reinforcing yarns and consumable yarns described later) move in the later described stage of obtaining the ion exchange membrane (flow direction), and TD means a direction substantially perpendicular to MD ... The yarns weaved along the MD are called MD yarns, and the yarns weaved along the TD are called TD yarns. Typically, the ion exchange membrane used for electrolysis is rectangular, and in many cases, the longitudinal direction is MD and the width direction is TD. By weaving reinforcing core materials that are MD yarns and reinforcing core materials that are TD yarns, better dimensional stability and mechanical strength can be achieved in many directions.

[0626] The placement range of the core reinforcing materials is not particularly limited, and the preferred placement can be appropriately provided in consideration of the physical properties desired for the ion exchange membrane, the environmental conditions in use, and the like.

[0627] The opening ratio of the core reinforcing materials is not particularly limited, but is preferably 30% or more, more preferably 50% or more and 90% or less. The opening ratio is preferably 30% or more in terms of the electrochemical characteristics of the ion exchange membrane, and preferably 90% or less in terms of the mechanical strength of the ion exchange membrane.

[0628] The relative aperture (coefficient of open porosity) of the reinforcing materials of the core here refers to the ratio (B / A) of the total surface area (B) through which substances such as ions (electrolyte solution and the cations contained therein (for example, ions sodium)), to the area (A) of any one surface of the body of the ion-exchange membrane. The total surface area (B) through which substances such as ions can pass may refer to the total areas of regions in which cations, electrolyte solution and the like are not retained in the ion exchange membrane by the reinforcing materials of the core and the like contained in the ion exchange membrane. membrane.

[0629] Figure 70 illustrates a schematic view for explaining the relative opening of the core reinforcing materials constituting the ion exchange membrane. Figure 70, in which a portion of the ion exchange membrane is shown enlarged, shows only the configuration of the reinforcing materials 21 and 22 of the core in these regions, without showing other elements.

[0630] By subtracting the total area (C) of the core reinforcing materials from the area of the area surrounded by the core reinforcing materials 21 along the longitudinal direction and the core reinforcing materials 22 located along the transverse direction, the area including the area (A) of the core reinforcing materials can the total area (B) of the regions through which substances such as ions can pass in the area (A) of the above-described region can be obtained. That is, the relative aperture can be determined by the following formula (I):

Relative aperture = (B) / (A) = ((A) - (C)) / (A) (I)

[0631] Among the reinforcing materials of the core, a film textile thread or highly oriented monofilaments including PTFE is particularly preferred in terms of chemical resistance and heat resistance. More specifically, more preferred are plain weave core reinforcing materials that use 50 to 300 denier film textile yarns made by cutting a PTFE-containing high tenacity porous sheet into ribbon-shaped pieces, or comprising highly oriented PTFE monofilaments of 50 to 300 denier sizes. 300 denier, and which have a weave density of 10 to 50 threads or monofilaments per inch and have a thickness in the range of 50 to 100 microns. The opening ratio of the ion exchange membrane including such core reinforcing materials is more preferably 60% or more.

[0632] Examples of the shape of the reinforcing yarns include round yarns and film threads.

[0633] (Through holes)

The ion exchange membrane preferably has through holes within the membrane body.

[0634] Through holes refer to holes that can form channels for ions generated during electrolysis and for an electrolyte solution. Through holes, which are tubular holes formed within the membrane body, are formed by dissolving the core consumables (or yarns) described below. The shape, diameter, or the like of the through holes can be controlled by selecting the shape or diameter of the core consumables (yarn consumables).

[0635] The formation of through holes within the ion exchange membrane can provide mobility of the electrolyte solution during electrolysis. The shape of the through holes is not particularly limited, but may be the shape of the core consumable materials used to form the through holes according to the production method described below.

[0636] The through holes are preferably formed to alternately pass on the anode side (sulfonic acid layer side) and cathode side (carboxylic acid layer side) of the core reinforcing materials. With this arrangement, in the region in which the through holes are formed on the cathode side of the core reinforcing materials, ions (eg sodium ions) supplied by the electrolyte solution filling the through holes can also flow to the cathode side of the core reinforcing materials. As a result, the flow of cations is not interrupted, and thus an additional reduction in the electrical resistance of the ion-exchange membrane is possible.

[0637] The through holes may be formed along only one predetermined direction of the membrane body constituting the ion exchange membrane, but are preferably formed along both the longitudinal direction and the transverse direction of the membrane body in view of exhibiting more stable electrolysis characteristics.

[0638] [Manufacturing Method]

A suitable example of a method for manufacturing an ion exchange membrane includes a method comprising the following steps (1) to (6):

Step (1): a step of producing a fluorine-containing polymer having an ion exchange group or an ion exchange group precursor capable of forming an ion exchange group by hydrolysis,

Step (2): a step of weaving at least a plurality of core reinforcing materials, if necessary, and consumable yarns that dissolve in acid or alkali and form through holes, to obtain a reinforcing material in which the consumable yarns are interposed between the core reinforcing materials, being adjacent to each other,

Step (3): a step of converting into a film the above fluorine-containing polymer having an ion exchange group or an ion exchange group precursor capable of forming an ion exchange group by hydrolysis,

Step (4): the step of introducing the above reinforcing materials, if necessary, into the above film to obtain a membrane body, inside which the reinforcing materials are placed,

Stage (5): stage of hydrolysis of the membrane body obtained in stage (4) (stage of hydrolysis) and

Step (6): The step of creating a coating layer on the membrane body obtained in step (5) (application step).

[0639] Next, each of the steps will be described in detail.

[0640] Step (1): the step of obtaining a fluoropolymer

In step (1), the monomeric starting materials described above in groups one to three are used to prepare the fluoropolymer. To regulate the ion-exchange capacity of the fluorine-containing polymer, the composition of the mixture of the starting monomer materials must be controlled during the production of the fluorine-containing polymer forming the said layers.

[0641] Step (2): a step of obtaining reinforcing materials

The reinforcing material is a woven fabric obtained by weaving reinforcing yarns or the like. The reinforcing material is embedded in the membrane to thereby form core reinforcing materials. When an ion-exchange membrane with through holes is formed, consumable yarns are additionally woven into the reinforcing material. The amount of consumable yarns contained in this case is preferably 10 to 80% by mass, more preferably 30 to 70% by mass, based on the total reinforcing material. The weaving of the consumable yarns can also prevent slippage of the yarns of the core reinforcing materials.

[0642] Viscose, polyethylene terephthalate (PET), cellulose, polyamide and the like are used as the consumable yarns that are dissolved in the membrane preparation step or in the electrolysis environment. Also preferred are monofilaments or multifilaments having a thickness of 20 to 50 denier and including polyvinyl alcohol and the like.

[0643] In step (2), the aperture ratio, the placement of the through holes, and the like can be controlled by adjusting the placement of the core reinforcing materials and the yarns consumed.

[0644] Step (3): Film forming step

In step (3), the fluoropolymer obtained in step (1) is formed into a film using an extruder. The film may have a single layer configuration, a two layer configuration of a sulfonic acid layer and a carboxylic acid layer as mentioned above, or a multilayer configuration of three or more layers.

[0645] Examples of the film forming method include the following:

a method in which a fluorine-containing polymer having a carboxylic acid group and a fluorine-containing polymer having a sulfonic acid group are separately formed into films; and

a method in which a fluorine-containing polymer having a carboxylic acid group and a fluorine-containing polymer having a sulfonic acid group are coextruded to form a composite film.

[0646] The number of each film can be more than one. Co-extrusion of different films is preferred because of their contribution to the increase in bond strength at the interface.

[0647] Step (4): The step of obtaining the membrane body

In step (4), the reinforcing material obtained in step (2) is embedded in the film obtained in step (3) to form a membrane body containing the reinforcing material.

[0648] Preferred examples of a method for forming a membrane body include (i) a method in which a fluorine-containing polymer having a precursor of a carboxylic acid group (e.g., a carboxylate functional group) (hereinafter referred to as a first layer) disposed on the cathode side and a fluorine-containing polymer having a precursor of a sulfonic acid group (for example, a sulfonyl fluoride functional group) (hereinafter, including this layer is called the second layer), is formed into a film by the method of coextrusion, and, if necessary, using a heat source and a vacuum source, a reinforcing material and a composite film from the second layer / the first layer is laminated in this order on a breathable heat-resistant release paper on a flat plate or drum having numerous pores on their surface, and combined at a temperature at which each polymer melts while at the same time evacuating air from under each of the layers by means of reduced pressure ; and (ii) a method in which, in addition to the composite film of the second layer / first layer, a fluorine-containing polymer having a precursor of a sulfonic acid group is separately preformed into a film (third layer), and optionally using a heat source and a source vacuum, the third layer film, the core reinforcing materials and the composite film from the second layer / first layer are laminated in this order on a breathable heat-resistant release paper on a flat plate or drum having multiple pores on their surface and combined at a temperature at which each polymer is melted while pumping air out from under each of the layers by means of reduced pressure.

[0649] Co-extrusion of the first and second layer here helps to increase the bond strength at the interface.

[0650] The method of combining under reduced pressure is characterized by making the third layer on the reinforcing material thicker than in the press-applied method. In addition, since the reinforcing material is fixed to the inner surface of the membrane body, the method provides sufficient retention of the mechanical strength of the ion exchange membrane.

[0651] Embodiments of the layering methods described herein are exemplary, and coextrusion may be performed after a preferred layering configuration (eg, a combination of layers) is appropriately selected in consideration of the desired membrane body layer configurations and physical properties, and the like.

[0652] In order to further improve the electrical characteristics of the ion exchange membrane, it is also possible to additionally place a fourth layer comprising a fluorine-containing polymer having both a precursor of a carboxylic acid group and a precursor of a sulfonic acid group between the first layer and the second layer, or the use of a fourth layer comprising a fluorine-containing polymer having both a precursor of a carboxylic acid group and a precursor of a sulfonic acid group instead of the second layer.

[0653] The method for forming the fourth layer may be a method in which a fluorine-containing polymer having a precursor of a carboxylic acid group and a fluorine-containing polymer having a precursor of a sulfonic acid group are separately prepared and then mixed, or it may be a method in which a monomer is copolymerized having a precursor of a carboxylic acid group; and a monomer having a sulfonic acid precursor.

[0654] When the fourth layer is used as a component of the ion exchange membrane, a coextruded film of the first layer and the fourth layer is formed, in addition, the third layer and the second layer are separately formed into films, and the laminating can be performed in the above manner. Alternatively, three layers of the first layer / fourth layer / second layer can be coextruded simultaneously to form a film.

[0655] In this case, the direction in which the extruded film flows out is MD. As mentioned above, it is possible to form a membrane body containing a fluorine-containing polymer having an ion exchange group on the reinforcing material.

[0656] In addition, the ion exchange membrane preferably has protrusions constituted by a fluoropolymer having a sulfonic acid group, that is, protrusions on the side of the surface constituted by the sulfonic acid layer. As a method for forming such protrusions, which is not particularly limited, a known method including forming protrusions on a resin surface can also be applied. A specific example of the method is a method for embossing the surface of a membrane body. For example, the aforementioned protrusions can be formed using the pre-embossed release paper when the above composite film, reinforcing material, and the like are combined. In the case where the protrusions are formed by embossing, the height and density of the protrusions can be controlled by the shape of the transferred relief (the shape of the release paper).

[0657] (5) Hydrolysis Step

At step (5), the stage of hydrolysis of the membrane body obtained at stage (4) is performed to convert the precursor of the ion-exchange group into an ion-exchange group (stage of hydrolysis).

[0658] In step (5), it is also possible to dissolve holes in the membrane body by dissolving and removing consumable yarns introduced into the membrane body by the action of an acid or alkali. The consumable yarns can remain in the through holes without being completely dissolved and removed. The consumable yarns remaining in the through holes can be dissolved and removed by the electrolyte solution when the ion exchange membrane is subjected to electrolysis.

[0659] The consumable yarn is dissolved in acid or alkali during the ion exchange membrane preparation step or in the electrolysis environment. The consumable yarns are washed out, thereby forming the through-holes at the appropriate locations.

[0660] Step (5) may be performed by immersing the membrane body obtained in step (4) in a hydrolysis solution containing an acid or alkali. An example of a hydrolysis solution that can be used is a mixed solution containing KOH and dimethyl sulfoxide (DMSO).

[0661] The mixed solution preferably contains KOH at normal concentration from 2.5 to 4.0 and DMSO from 25 to 35% by weight.

[0662] The temperature in the hydrolysis is preferably 70 to 100 ° C. The higher the temperature, the greater the apparent thickness can be. The temperature is more preferably 75 to 100 ° C.

[0663] The duration of the hydrolysis is preferably 10 to 120 minutes. The longer the hydrolysis takes, the greater the apparent thickness can be. The duration of the hydrolysis is preferably 20 to 120 minutes.

[0664] The step of forming the through holes by washing out the sacrificial yarns will now be described in more detail. Figures 71 (a) and (b) are schematic views for explaining a method of forming vias in an ion exchange membrane.

[0665] Figures 71 (a) and (b) show reinforcing yarns 52, sacrificial yarns 504a, and through holes 504 formed only by sacrificial yarns 504a, without illustrating other features such as a membrane body.

[0666] First, the reinforcing yarns 52, which are to constitute the core reinforcing materials in the ion exchange membrane, and the consumable yarns 504a for forming the through holes 504 in the ion exchange membrane are used as interlaced reinforcing materials. Then, in step (5), the consumable yarns 504a are washed out to form the through holes 504.

[0667] The above method is simple because the method of interlacing reinforcing yarns 52 and consumable yarns 504a can be adjusted depending on the order of placement of the reinforcing materials of the core and through holes in the body of the ion exchange membrane.

[0668] Figure 71 (a) illustrates an example of a plain weave reinforcing material in which the reinforcing yarns 52 and the sacrificial yarns 504a are interlaced in both the longitudinal direction and the transverse direction in the paper, and, if necessary, the order of placement of the reinforcing yarns 52 and the sacrificial yarn 504a in the reinforcing material can be changed.

[0669] (6) Application Step

In step (6), a coating layer can be formed by preparing a coating liquid containing particles of inorganic material obtained by grinding raw ore or melting raw ore and a binder, applying a coating liquid to the surface of the ion exchange membrane obtained in step (5), and drying the coating liquids.

[0670] A preferred binder is a binder obtained by hydrolysis of a fluorine-containing polymer having an ion exchange group precursor with an aqueous solution containing dimethyl sulfoxide (DMSO) and potassium hydroxide (KOH), and then immersing the polymer in hydrochloric acid to replace the counter ion of the ion exchange group with H ⁺ ( for example, a fluorine-containing polymer having a carboxyl group or a sulfo group). Thus, the polymer is more likely to dissolve in water or ethanol, as mentioned below, which is preferred.

[0671] This binder is dissolved in a mixed solution of water and ethanol. The volume ratio between water and ethanol is preferably 10: 1 to 1:10, more preferably 5: 1 to 1: 5, even more preferably 2: 1 to 1: 2. The particles of inorganic material are dispersed in the dissolving liquid by means of a ball mill, thereby forming a coating liquid. In this case, it is also possible to correct the average particle size and the like of particles by adjusting the duration and speed of rotation during dispersion. The preferred amount of the mixed particles of inorganic material and binder is as mentioned above.

[0672] The concentration of the particles of inorganic material and binder in the coating liquid is not particularly limited, but a free-flowing coating liquid is preferable. This makes it possible to uniformly apply the ion exchange membrane to the surface.

[0673] In addition, a surfactant may be added to the dispersion when particles of inorganic material are dispersed. As the surfactant, nonionic surfactants are preferred and examples include HS-210, NS-210, P-210 and E-212 from NOF CORPORATION.

[0674] The resulting coating liquid is applied to the surface of the ion exchange membrane by spray application or roller coating, thereby forming an ion exchange membrane.

[0675] [Microporous Membrane]

The microporous membrane of the present embodiment is not particularly limited as long as the membrane can be formed to form an electrode laminated article for electrolysis as mentioned above. A variety of microporous membranes can be used.

The porosity of the microporous membrane of the present embodiment is not particularly limited, but may be, for example, 20 to 90, and preferably 30 to 85. The above porosity can be calculated by the following formula:

Porosity = (1– (dry weight of the membrane) / (weight calculated from the volume, calculated from the values of the thickness, width and length of the membrane, and the density of the membrane material)) × 100

The average pore size in the microporous membrane of the present embodiment is not particularly limited and may be, for example, 0.01 µm to 10 µm, preferably 0.05 µm to 5 µm. With regard to the average pore size, for example, the membrane is cut vertically in the direction of thickness, and the cross section is examined by field emission scanning electron microscopy (FE-SEM). The average pore size can be obtained by measuring the diameter of about 100 pores and averaging the results.

The thickness of the microporous membrane of the present embodiment is not particularly limited and may be, for example, 10 µm to 1000 µm, preferably 50 µm to 600 µm. The above thickness can be measured using, for example, a micrometer (manufactured by Mitutoyo Corporation) or the like.

Specific examples of a microporous membrane as above include Zirfon Perl UTP 500 manufactured by Agfa (also referred to as a Zirfon membrane in this embodiment) and are described in International Publication No. WO 2013-183584 and International Publication No. WO 2016-203701.

[0676] In the present embodiment, the membrane preferably comprises a first ion exchange resin layer and a second ion exchange resin layer having an EW (ion exchange capacity) value different from the EW of the first ion exchange resin layer. In addition, the membrane preferably contains a first ion exchange resin layer and a second ion exchange resin layer having a different functional group than the functional group in the first ion exchange resin layer. The ion exchange capacity can be adjusted by the introduced functional group, and the functional groups that can be introduced are as mentioned above.

[0677] In the present embodiment, the portion of the laminate 25 that is sandwiched between the anode seal 12 and the cathode seal 13 is preferably a non-conductive surface. The "conductive surface" corresponds to an area designed to allow migration of electrolytes between the anode chamber and the cathode chamber, and the "non-conductive surface" is an area not corresponding to the conductive surface.

[0678] In the present embodiment, the outermost perimeter of the laminate may be on the inner side or farther outward than the outermost perimeter of the anode side seal and cathode side seal toward the conductive surface, but is preferably further outward. With this configuration, the outermost perimeter farther outward can be used as a clamped edge portion, and thus the workability in the assembly of the cell is improved. The outermost perimeter of the laminate here is the outermost perimeter of the membrane and the electrolysis electrode in combination. That is, when the outermost perimeter of the electrolysis electrode is farther outward with respect to the joint contact surface than the outermost perimeter of the membrane, the outermost perimeter of the laminate means the outermost perimeter of the electrolysis electrode. In contrast, when the outer perimeter of the electrolysis electrode is on the inner side of the joint contact surface than the outermost perimeter of the membrane, the outermost perimeter of the laminate means the outermost perimeter of the membrane.

The positional relationship will be described using Figures 72 and 73. In particular, Figures 72 and 73 show the positional relationship of the seals and the laminate when the two electrolytic cells shown, for example, in Figure 64B are viewed from the α-direction. In Figures 72 and 73, a rectangular seal A having an opening in the center is located on the frontmost side. The rectangular membrane B is behind A and the rectangular electrolysis electrode C is further behind B. That is, the seal opening A is a region corresponding to the conductive surface of the laminate.

In Figure 72, the outermost perimeter A1 of the seal A is on an inner side more than the outermost perimeter B1 of the membrane B and the outermost perimeter C1 of the electrolysis electrode C towards the conductive surface.

In Figure 73, the outermost perimeter A1 of the seal A is further outward than the outermost perimeter C1 of the electrolysis electrode C towards the conductive surface, but the outermost perimeter B1 of membrane B is further outward than the outermost perimeter A1 of the seal A towards the conductive surface.

In the present embodiment, the laminated article must be sandwiched between the anode-side seal and the cathode-side seal, and the electrolysis electrode itself may not be inserted directly between the anode-side seal and the cathode-side seal. That is, provided that the electrolysis electrode itself is fixed to the membrane, only the membrane can be interposed directly between the anode side seal and the cathode side seal. In the present embodiment, from the viewpoint of more stable anchoring of the electrolysis electrode in the electrolysis cell, both the electrolysis electrode and the membrane are preferably sandwiched between the anode side seal and the cathode side seal.

[0679] In the present embodiment, the membrane and the electrolysis electrode are fixed by at least an anode seal and a cathode seal to be in the form of a laminated article, but may take other attachment configurations. For example, the following exemplary attachment configuration may be used, or two or more attachment configurations may be used in combination.

[0680] In the present embodiment, at least a portion of the electrolysis electrode preferably penetrates the membrane and thereby is fixed. This aspect will be described using Figure 74A.

In Figure 74A, at least a portion of the electrolysis electrode 2 penetrates the membrane 3 and is thereby secured. Figure 74A shows an example in which the electrolysis electrode 2 is a metal porous electrode. That is, in Figure 74A, a plurality of portions of the electrolysis electrode 2 are shown as separate, but the portions are continuous. Thus, a cross-sectional view of a solid metal porous electrode is shown (the same applies in Figures 75-78 below).

In the configuration of the electrode, when the membrane 3 in a predetermined position (the position that is the attachment region) is pressed against the electrolysis electrode 2, for example, a part of the membrane 3 is pressed into the geometry of the protrusions or the geometry of the holes on the surface of the electrolysis electrode 2. Then, the depressions on the surface of the electrode and the protrusions around the holes penetrate into the membrane 3 and preferably penetrate the outer surface 3b of the membrane 3, as shown in Figure 74A.

[0681] As described above, the attachment pattern in Figure 74A can be formed by pressing the membrane 3 against the electrolysis electrode 2. In this case, the membrane 3 is softened by heating and then subjected to thermal compression and thermal vacuum treatment. The electrolysis electrode 2 then penetrates the membrane 3. Alternatively, the membrane 3 can be used in a molten state. In this case, the membrane 3 is preferably sucked from the outer surface 2b side (rear surface side) of the electrolysis electrode 2 in the state shown in FIG. 74B. The area in which the membrane 3 is pressed into the electrolysis electrode 2 constitutes the "attachment area".

[0682] The mount configuration shown in Figure 74A can be viewed with a magnifying glass (loupe), optical microscope, or electron microscope. Since the electrolysis electrode 2 has penetrated the membrane 3, it is possible to evaluate the attachment configuration in FIG. 74A by testing the conductivity between the outer surface 3b of the membrane 3 and the outer surface 2b of the electrolysis electrode 2 using a tester or the like.

[0683] In the present embodiment, at least a portion of the electrolysis electrode is preferably located inside the membrane and thereby fixed in the attachment region. This aspect will be described using Figure 75A.

[0684] As described above, the surface of the electrolysis electrode 2 has a protrusion geometry and a hole geometry. In the embodiment shown in FIG. 75A, a portion of the electrode surface enters the membrane 3 to reach a predetermined position (the position that is the attachment region) and is thereby secured. The attachment configuration shown in FIG. 75A may be formed by pressing the membrane 3 into the surface of the electrolysis electrode 2. In this case, the attachment configuration of FIG. 75A is preferably created by softening the membrane 3 by heating, and then by thermocompression or thermal vacuum treatment of the membrane 3. Alternatively, the attachment configuration of FIG. 75A can be formed by melting the membrane 3. In this case, the membrane 3 is preferably sucked from the outside. surfaces 2b (sides of the rear surface) of the electrode 2 for electrolysis.

[0685] The attachment configuration shown in Figure 75A can be observed with a magnifying glass (loupe), an optical microscope, or an electron microscope. Particularly preferred is a method comprising subjecting the sample to a resin embedding treatment, then generating a cross-section with a microtome and examining the cross-section. In the attachment configuration shown in FIG. 75A, the electrolysis electrode 2 does not penetrate the membrane 3. Thus, the conductivity test cannot detect conductivity between the outer side 3b of the membrane 3 and the outer surface 2b of the electrolysis electrode 2.

[0686] In the present embodiment, it is preferable that the laminated article has an attachment member for securing the membrane and the electrolysis electrode. This aspect will be described using Figures 76A-C.

[0687] The fastening configuration shown in Figure 76A is a configuration that uses a fastener 7 that is separate from the electrolysis electrode 2 and the membrane 3, and the fastener 7 penetrates and thereby secures the electrolysis electrode 2 and the membrane 3 The electrolysis electrode 2 need not be pierced by the fastener 7, and must be fixed with the fastener 7 so as not to separate from the membrane 3. The material for the fastener 7 is not particularly limited, and materials consisting of such as metal, resin or the like. Examples of the metal include nickel, nichrome, titanium, and stainless steel (SUS). Their oxides can be used. Examples of the resin that can be used include fluorine resins (e.g., polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkoxyethylene (PFA) copolymers, tetrafluoroethylene-ethylene copolymers (ETFE), membrane materials 3 described below, polyvinylidene fluoride) ethylene (PVDF) –Diene rubber (EPDM), polyethylene (PP), polypropylene (PE), nylon and aramid.

For example, the present embodiment employs a filamentary metal or polymer for crosslinking at a predetermined position (attachment position) between the outer surface 2b of the electrolysis electrode 2 and the outer surface 3b of the membrane 3, as shown in Figures 76B and C. It is also possible to fix electrode 2 for electrolysis with membrane 3 using fastening means such as pins.

[0688] The attachment configuration shown in FIG. 77 is a configuration in which attachment is achieved by an organic resin (adhesive layer) disposed between the electrolysis electrode 2 and the membrane 3. That is, FIG. 77 shows a configuration in which an organic resin is used as an attachment. of the element 7 is placed in a predetermined position (the position of the attachment region) between the electrolysis electrode 2 and the membrane 3 to thereby secure them by gluing. For example, an organic resin is applied to the inner surface 2a of the electrolysis electrode 2, the inner surface 3a of the membrane 3, or one or both of the inner surface 2a of the electrolysis electrode 2 and the inner surface 3a of the membrane 3. Then, the attachment pattern shown in FIG. by laminating the electrolysis electrode 2 to the membrane 3. The materials for the organic resin are not particularly limited, but examples thereof that can be used include fluorine resins (e.g., PTFE, PFA, and ETFE), and resins like the materials constituting the membrane 3, such as mentioned above. Commercially available fluorine adhesives and PTFE dispersions can also be used, as appropriate. In addition, multipurpose vinyl acetate adhesives, adhesives based on ethylene-vinyl acetate copolymers, adhesives based on acrylic resins, α-olefin adhesives, adhesives based on styrene-butadiene rubber latexes, adhesives based on vinyl chloride nitric resins, chlorinated adhesives , urethane rubber adhesives, epoxy adhesives, silicone resin adhesives, modified silicone adhesives, epoxy modified silicone resin adhesives, silylated urethane resin adhesives, cyanoacrylate adhesives, and the like.

In the present embodiment, organic resins that dissolve in an electrolyte solution or dissolve or decompose during electrolysis can be used. Examples of organic resins that dissolve in electrolyte solution or dissolve or decompose during electrolysis include, but are not limited to, vinyl acetate adhesives, ethylene vinyl acetate copolymer adhesives, acrylic resin adhesives, α-olefin adhesives, butadiene adhesives –Styrene rubber latexes, adhesives based on vinyl chloride resins, chloroprene adhesives, nitrile rubber adhesives, adhesives based on urethane rubbers, epoxy adhesives, adhesives based on silicone resins, modified silicone adhesives, modified adhesives based on epoxy resin and cyanoacrylate adhesives.

The mounting configuration shown in FIG. 77 can be observed with an optical microscope or an electron microscope. Particularly preferred is a method comprising subjecting the sample to a resin embedding treatment, then generating a cross-section with a microtome and examining the cross-section.

[0689] In the present embodiment, at least a portion of the fastener preferably grips the membrane and the electrolysis electrode from the outside. This aspect will be described using Figure 78A.

The fastening configuration shown in FIG. 78A is a configuration in which the electrolysis electrode 2 and the membrane 3 are clamped outwardly and fixed. That is, the outer surface 2b of the electrolysis electrode 2 and the outer surface 3b of the membrane 3 are sandwiched between and fastened by the clamping means as the fastening member 7. In the fastening configuration shown in FIG. 78A, the state in which the clamping means engages with the electrolysis electrode 2 and the membrane is also included. 3. Examples of clamping means include tape and paper clips.

In the present embodiment, a clamping member that dissolves in an electrolyte solution can be used. Examples of a clamping member that dissolves in an electrolyte solution include PET tape and staples, and PVA tape and staples.

[0690] In the attachment configuration shown in Figure 78A, unlike the examples of Figures 74 to 77, the electrolysis electrode 2 and the membrane 3 are not connected at the interface therebetween, but the inner surface 2a of the electrolysis electrode 2 and the inner surface 3a of the membrane 3 only adjoin each other or are opposite each other. By removing the clamping element, it is possible to release the electrolysis electrode 2 and the membrane 3 from the fixed state and separate the electrolysis electrode 2 from the membrane 3.

Although not shown in Figure 78A, it is also possible to secure the electrolysis electrode 2 and membrane 3 using a clamping member in the electrolytic cell.

[0691] In addition, in the present embodiment, at least a part of the fastening member preferably fixes the membrane and the electrolysis electrode by magnetic force. This aspect will be described using Figure 78B.

The fastening configuration shown in FIG. 78B is a configuration in which the electrolysis electrode 2 and the membrane 3 are clamped outwardly and fixed. The difference from the example in FIG. 78A is that a pair of magnets is used as the clamping member, which constitutes the holding member. In this aspect of the attachment configuration shown in FIG. 78B, the laminate 1 is attached to the electrolysis cell. Thereafter, during operation of the cell, the clamping member can be left as it is, or it can be removed from the laminate 1.

Although not shown in Figure 78B, it is also possible to secure the electrolysis electrode 2 and membrane 3 using a clamping member in the electrolytic cell. When a magnetic material that adheres to a magnet is used as part of the material for an electrolytic cell, one fastening material is placed on the surface side of the membrane. Then the fastening material and the electrolytic cell can sandwich and fix between them the electrode 2 for electrolysis and the membrane 3.

[0692] A plurality of attachment lines may be provided. That is, 1, 2, 3, etc., n lines of attachment areas may be placed from one side of the contour towards the inner side of the laminate 1. n represents an integer of 1 or more. The m – th (m <n) line of the fastening areas and the L – th (m <L≤n) line of the fastening areas can in each case be formed having a different fastening pattern.

[0693] The line of attachment regions formed in the electrically conductive region preferably has a linear symmetrical shape. This allows you to control the concentration of mechanical stresses. For example, when orthogonally intersecting directions are designated X-direction and Y-direction, you can configure the retention area by placing each line of retention areas in X-direction and Y-direction, or place multiple lines of retention areas at equal intervals in X-direction and Y-direction. Y-direction. The number of lines of the attachment areas in each of the X-direction and Y-direction is not limited, but is preferably 100 or less in the X-direction and the Y-direction. From the viewpoint of achieving planarity of the electrically conductive region, the number of lines of the attachment regions is preferably 50 or less in each of the X-direction and Y-direction.

[0694] When the attachment area in the present embodiment has the attachment configuration shown in FIG. 74A or FIG. 76, a sealing material is preferably applied to the surface of the membrane in the attachment area in order to prevent short circuit caused by contact between the anode and cathode. The materials described for the aforementioned adhesives can be used as a sealing material.

[0695] The laminated article in the present embodiment may have various attachment areas as mentioned above, but from the standpoint of achieving sufficient electrolysis capacity, these attachment areas are preferably present on the non-conductive surface.

[0696] The laminated article in the present embodiment may have different attachment areas as mentioned above, but the electrolysis electrode preferably satisfies the aforementioned "applied force" value, especially in the area in which there is no attachment area (non-fixed area). That is, the force applied per unit mass · unit area of the electrode for electrolysis is preferably less than 1.5 N / (mg · cm ² ).

[0697] In the present embodiment, it is preferable that the membrane includes an ion exchange membrane including a surface layer containing an organic resin, and the electrode for electrolysis is fixed with an organic resin. The organic resin is as mentioned above and can be formed into the surface layer of the ion exchange membrane by a variety of known methods.

[0698] (Water electrolysis)

The electrolytic cell of the present embodiment as an electrolysis cell in the case of water electrolysis has a configuration in which an ion exchange membrane in the electrolysis cell for use in the case of the above conventional salt electrolysis is replaced with a microporous membrane. The supplied raw material, which is water, is different from the material for the electrolytic cell in the case of the above-mentioned conventional salt electrolysis. As for other components, parts similar to those of the electrolysis cell in the case of conventional salt electrolysis can also be used in a water electrolysis cell. Since chlorine gas is generated in the anode chamber in conventional salt electrolysis, titanium is used as the anode chamber material, but in the case of water electrolysis, only oxygen gas is emitted in the anode chamber. Thus, a material identical to that of the cathode chamber can be used. Nickel is one example of this. A catalytic coating for generating oxygen is suitable for coating the anode. Examples of the catalytic coating include metals, oxides and hydroxides of platinum group metals and metals from the transition metal group. For example, elements such as platinum, iridium, palladium, ruthenium, nickel, cobalt, and iron can be used.

[0699] (Method for manufacturing an electrolyzer and a method for updating a laminated article)

The method for updating a laminated article in an electrolytic cell of the present embodiment has the step of separating the laminated article in the present embodiment from the anode side seal and the cathode side sealing, thereby removing the laminated article from the cell, and the step of inserting a new laminated article between the anode side seal and the cathode side seal. A new laminated article means a laminated article in the present embodiment, and at least one of the electrolysis electrode and the membrane must be new.

In the step of laying the above-described laminated article, from the viewpoint of more stable anchoring of the electrolysis electrode in the electrolysis cell, both the electrolysis electrode and the membrane are preferably sandwiched between the anode side seal and the cathode side seal.

In addition, the method for manufacturing an electrolytic cell of the present embodiment has the step of interposing the laminated article in the present embodiment between the anode side seal and the cathode side seal.

The electrolytic cell manufacturing method and the refurbishing method of the layered article of the present embodiment configured as described above can improve the efficiency during refurbishment of the electrode in the cell, and furthermore, can provide excellent electrolysis performance even after refurbishment.

In addition, in the step of laying the above-described laminated article, from the viewpoint of more stable anchoring of the electrolysis electrode in the electrolysis cell, both the electrolysis electrode and the membrane are preferably sandwiched between the anode side seal and the cathode side seal.

[0700] <Fifth embodiment>

Here, a fifth embodiment of the present invention will be described in detail with reference to Figures 91-102.

[0701] [Method for Manufacturing an Electrolyzer]

A method for manufacturing an electrolysis cell according to a fifth embodiment (hereinafter in the section <Fifth Embodiment> simply referred to as “the present embodiment”) is a method for forming a new electrolysis cell by placing an electrolysis electrode or a laminated article from an electrolysis electrode and a new membrane in an existing electrolysis cell including the anode, the cathode, which is opposite the anode, and the membrane, which is located between the anode and the cathode, and an electrode for electrolysis or a laminated article in the form of a winding is used. As described above, according to the method for manufacturing an electrolysis cell according to the present embodiment, an electrolysis electrode or a laminated article of an electrolysis electrode and a new membrane in the form of a coil is used. Thus, the size of the electrolysis electrode or laminated article when used as a cell of an electrolytic cell can be reduced for transportation or the like, and operational efficiency during renewal of the electrode in the cell can be improved.

[0702] In the present embodiment, an existing electrolyzer comprises an anode, a cathode that is opposite the anode, and a membrane that is interposed between the anode and the cathode as a structural member, in other words, contains an electrolytic cell. The existing electrolytic cell is not particularly limited as long as it contains the above-described structural elements, and various known configurations can be used.

[0703] In the present embodiment, the new electrolysis cell further comprises an electrolysis electrode or laminated article, in addition to an element that has already served as an anode or cathode in the existing electrolysis cell. That is, the "electrolysis electrode" placed when forming a new electrolytic cell serves as an anode or cathode, and is separate from the cathode and anode in the existing electrolysis cell. In the present embodiment, even in the case where the efficiency of the anode and / or cathode in electrolysis has deteriorated due to the operation of the existing electrolysis cell, placing the electrolysis electrode separately from them allows the performance of the anode and / or cathode to be restored. In the case where the laminated article is used in the present embodiment, the new ion exchange membrane is placed in combination, and thus the characteristics of the ion exchange membrane that have deteriorated due to operation can be simultaneously updated. As referred to herein, "performance upgrade" means achieving performance that is comparable to the original performance that the existing cell had before operation, or performance that exceeds the original performance.

[0704] In the present embodiment, the existing electrolytic cell is considered to be "an electrolyzer that was already in operation" and a new electrolysis cell is considered to be an "electrolyzer that has not yet been operated". That is, once the cell formed as a new cell starts to be used, the cell becomes the “existing cell in the present embodiment”. Placing an electrolysis electrode or laminated article in this existing electrolysis cell creates a “new electrolysis cell of the present embodiment”.

[0705] Next, a case of performing conventional salt electrolysis using an ion exchange membrane as an exemplary membrane and one embodiment of an electrolyser will be described in detail. In the section <Fifth Embodiment>, unless otherwise stated, “electrolyzer in the present embodiment” provides for both “existing electrolyzer in the present embodiment” and “new electrolyzer of this embodiment”.

[0706] [Electrolytic Cell]

First, an electrolytic cell that can be used as a structural member of an electrolytic cell in the present embodiment will be described. Figure 91 illustrates a cross-sectional view of an electrolytic cell 1.

The electrolytic cell 1 contains an anode chamber 10, a cathode chamber 20, a dividing wall 30 located between the anode chamber 10 and the cathode chamber 20, an anode 11 located in the anode chamber 10, and a cathode 21 located in the cathode chamber 20. If necessary, an electrolytic cell 1 has a substrate 18a and a reverse current absorbing layer 18b formed on the substrate 18a, and may include a reverse current absorber 18 disposed in the cathode chamber. The anode 11 and the cathode 21, which are part of the electrolytic cell 1, are electrically connected to each other. In other words, the electrolytic cell 1 contains the following cathode structure. The cathode structure 40 comprises a cathode chamber 20, a cathode 21 disposed in the cathode chamber 20, and a reverse current absorber 18 disposed in the cathode chamber 20, the reverse current absorber 18 having a substrate 18a and a reverse current absorbing layer 18b formed on the substrate 18a as shown in Figure 95, and the cathode 21 and the reverse current absorbing layer 18b are electrically connected. In addition, the cathode chamber 20 has a current collector 23, a holder 24 supporting the current collector, and a metal elastic body 22. The metal elastic body 22 is placed between the current collector 23 and the cathode 21. The holder 24 is located between the current collector 23 and the partition 30. The current collector 23 is electrically connected to cathode 21 through the metal elastic body 22. The separating partition 30 is electrically connected to the current collector 23 through the holder 24. Accordingly, the separating partition 30, the holder 24, the current collector 23, the metal elastic body 22 and the cathode 21 are electrically connected to each other. The cathode 21 and the reverse current absorbing layer 18b are electrically connected. The cathode 21 and the reverse current absorbing layer 18b may be connected directly, or may be connected indirectly through a down conductor, a holder, a metal resilient body, a baffle, or the like. The entire surface of the cathode 21 is preferably coated with a catalyst layer for the reduction reaction. The form of the electrical connection may be a form in which the baffle 30 and the support 24, the support 24 and the collector 23 and the collector 23 and the metal resilient body 22 are in each case directly connected to each other, and the cathode 21 is laminated on the metal resilient body 22. Examples methods for directly attaching these structural elements to each other include welding and the like. Alternatively, the reverse current absorber 18, cathode 21, and current collector 23 may be collectively referred to as cathode structure 40.

[0707] Figure 92 illustrates a cross-sectional view of two electrolytic cells 1 that are adjacent in electrolytic cell 4. Figure 93 shows electrolytic cell 4. Figure 94 shows a step of assembling cell 4.

[0708] As shown in Figure 92, the electrolytic cell 1, the cation exchange membrane 2, and the electrolytic cell 1 are arranged in series in this order. Ion exchange membrane 2 is located between the anode chamber of one electrolytic cell 1 of two electrolytic cells that are adjacent in the electrolyzer and the cathode chamber of another electrolytic cell 1. That is, the anode chamber 10 of the electrolytic cell 1 and the cathode chamber 20 of the adjacent electrolytic cell 1 are separated by a cation exchange membrane 2. As shown in Figure 93, electrolytic cell 4 consists of a plurality of electrolytic cells 1 connected in series through an ion exchange membrane 2. That is, electrolytic cell 4 is a bipolar electrolyzer including a plurality of electrolytic cells 1 in series and ion exchange membranes 2, in each case arranged between adjacent electrolytic cells 1. As shown in Figure 94, cell 4 is assembled by placing a plurality of electrolytic cells 1 in series through the ion exchange membrane 2 and bonding the cells by means of a clamping device 5.

[0709] Electrolyzer 4 has an anode lead 7 and a cathode lead 6 that are connected to a power supply. An anode 11 of an electrolytic cell 1 located at the farthest end of a plurality of electrolytic cells 1 connected in series in an electrolysis cell 4 is electrically connected to an anode terminal 7. A cathode 21 of an electrolytic cell located at an end opposite to the anode terminal 7 among the plurality of electrolytic cells 1, connected in series in the electrolytic cell 4, electrically connected to the cathode terminal 6. Electric current during electrolysis flows from the side of the anode terminal 7 through the anode and the cathode of each electrolytic cell 1 towards the cathode terminal 6. At both ends of the connected electrolytic cells 1 there may be an electrolytic cell, having only an anode chamber (anode outlet cell), and an electrolytic cell having only a cathode chamber (cathode outlet cell). In this case, the anode terminal 7 is connected to an anode terminal cell located at one end, and the cathode terminal 6 is connected to a cathode terminal cell located at the other end.

[0710] In the case of brine electrolysis, brine is supplied to each anode chamber 10, and pure water or low-concentration aqueous sodium hydroxide solution is supplied to each cathode chamber 20. Each liquid is supplied from an electrolyte solution supply pipe (not shown) through a hose for supplying an electrolyte solution (not shown in the figure) to each electrolytic cell 1. The electrolyte solution and electrolysis products are removed from the pipe for removing the electrolyte solution (not shown in the figure). During electrolysis, sodium ions in the brine migrate from the anode chamber 10 of one electrolytic cell 1 through the ion exchange membrane 2 to the cathode chamber 20 of the adjacent electrolytic cell 1. Thus, the electric current during electrolysis flows in the direction in which the electrolytic cells 1 are connected in series. That is, an electric current flows through the cation exchange membrane 2 from the anode chamber 10 towards the cathode chamber 20. When the brine is electrolyzed, chlorine gas is generated on the anode 11 side, and sodium hydroxide (dissolved) and hydrogen gas are generated on the cathode 21 side.

[0711] (Anode chamber)

The anode chamber 10 has an anode 11 or an anode supply conductor 11. Here, under the supply conductor is meant a worn electrode (ie, an existing electrode), an electrode not having a catalytic coating, and the like. When the electrolysis electrode in the present embodiment is inserted on the anode side, 11 serves as an anode supply conductor. When the electrolysis electrode of the present embodiment is not inserted on the anode side, 11 serves as an anode. The anode chamber 10 preferably has an anode-side electrolyte solution supply unit that supplies electrolyte solution to the anode chamber 10, a baffle plate that is positioned above the anode-side electrolyte solution supply unit so as to be substantially parallel or inclined with respect to the baffle 30, and a gas-liquid separator located above the baffle plate for separating gas from an electrolyte solution including admixed gas.

[0712] (Anode)

When the electrode for electrolysis of the present embodiment is not inserted on the anode side, the anode 11 is in the frame of the anode chamber 10 (i.e., in the anode frame). As the anode 11, a metal electrode such as a so-called DSA (R) can be used. DSA is an electrode including a titanium substrate, the surface of which is coated with an oxide including ruthenium, iridium and titanium as components.

As for the shape, any of a perforated metal sheet, a nonwoven fabric, a porous metal, an expanded metal sheet, an electrospinning metal porous foil, a so-called woven metal mesh formed by interlacing of thin metal filaments, and the like can be used.

[0713] (Anode supply conductor)

When the electrode for electrolysis of the present embodiment is inserted on the anode side, an anode supply conductor 11 is provided on the frame of the anode chamber 10. A metal electrode such as a so-called DSA (R) can be used as the anode supply conductor 11, and can also be used titanium without catalytic coating. Alternatively, a DSA having a thinner catalytic coating can also be used. In addition, an already used anode can also be used.

As for the shape, any of a perforated metal sheet, a nonwoven fabric, a porous metal, an expanded metal sheet, an electrospinning metal porous foil, a so-called woven metal mesh formed by interlacing of thin metal filaments, and the like can be used.

[0714] (Anode side electrolyte solution supply unit)

An anode-side electrolyte solution supply unit that supplies an electrolyte solution to the anode chamber 10 is connected to a pipe for supplying an electrolyte solution. The anode side electrolyte solution supply unit is preferably disposed under the anode chamber 10. As the anode side electrolyte solution supply unit, for example, a pipe on the surface of which lumen portions (dispersion tube) and the like can be used. Such a tube is more preferably located along the surface of the anode 11 and parallel to the bottom 19 of the electrolytic cell. This pipe is connected to a pipe for supplying an electrolyte solution (a liquid supply pipe), which supplies an electrolyte solution to an electrolytic cell 1. The electrolyte solution supplied from a liquid supply pipe is passed through a pipe into an electrolytic cell 1 and is fed from holes made on the pipe surface inside the anode chambers 10. Placing the pipe along the surface of the anode 11 and parallel to the bottom 19 of the electrolytic cell is preferable because the electrolyte solution can be uniformly supplied to the inside of the anode chamber 10.

[0715] (Anode side gas-liquid separator)

The anode side gas / liquid separator is preferably located above the baffle plate. The purpose of the anode side gas / liquid separator is to separate the generated gas, such as chlorine gas, from the electrolyte solution during electrolysis. Unless otherwise indicated, "above" means the upward direction in the electrolytic cell 1 in FIG. 91, and "under" means the downward direction in the electrolytic cell 1 in FIG. 91.

[0716] The gas generated during electrolysis, evolved in the electrolytic cell 1, and the electrolyte solution form a mixed phase (gas-liquid mixed phase), which is then discharged from the system. As a consequence, pressure fluctuations within the electrolytic cell 1 cause vibration, which can lead to physical damage to the ion exchange membrane. To prevent this phenomenon, the electrolytic cell 1 of the present embodiment is preferably equipped with an anode-side gas-liquid separator for separating gas from liquid. The anode-side gas-liquid separator is preferably provided with a defoamer plate to eliminate bubbles. When the gas-liquid mixed phase stream flows through the defoamer plate, the bubbles burst, thereby separating the electrolyte solution and gas. As a result, vibration during electrolysis can be prevented.

[0717] (Baffle plate)

The baffle plate is preferably positioned above the anode side electrolyte solution supply unit and is positioned substantially parallel or obliquely with respect to the baffle 30. The baffle plate is a baffle plate that controls the flow of electrolyte solution into the anode chamber 10. When the baffle plate is provided, it can cause circulation electrolyte solution (brine or the like) inside the anode chamber 10, thereby making the concentration more uniform. To create internal circulation, the baffle plate is preferably positioned so as to separate the space near the anode 11 from the space near the baffle 30. For this reason, the baffle plate is preferably positioned so that it is opposite the surface of the anode 11 and the surface of the baffle 30. In the space near the anode separated by the baffle plate, electrolysis occurs, the concentration of the electrolyte solution (brine concentration) decreases, and a generated gas such as chlorine gas is released. This leads to a difference in the specific gravity of the gas-liquid mixture between the space near the anode 11 and the space near the dividing wall 30, separated by a baffle plate. Using this difference, it is possible to stimulate the internal circulation of the electrolyte solution in the anode chamber 10, thereby making the concentration distribution of the electrolyte solution in the anode chamber 10 more uniform.

[0718] Although not shown in Figure 91, a down conductor may also optionally be provided within the anode chamber 10. The material and configuration of such a current collector can be the same as for the aforementioned collector of the cathode chamber. In the anode chamber 10, the anode 11 itself can also serve as a down conductor.

[0719] (Divider)

The dividing wall 30 is disposed between the anode chamber 10 and the cathode chamber 20. The dividing wall 30 may be referred to as a separator, and the anode chamber 10 and the cathode chamber 20 are separated from each other by a dividing wall 30. As the dividing wall 30, a baffle known as a separator can be used. electrolysis, and an example thereof comprises a baffle formed by welding a nickel-containing plate on the cathode side and a titanium-containing plate on the anode side.

[0720] (Cathode Chamber)

In the cathode compartment 20, when the electrolysis electrode of the present embodiment is inserted on the cathode side, 21 serves as a cathode supply conductor. When the electrolysis electrode of the present embodiment is not inserted on the cathode side, 21 serves as the cathode. When a return current absorber is present, the cathode or cathode supply conductor 21 is electrically connected to the return current absorber. The cathode chamber 20, like the anode chamber 10, preferably has a cathode-side electrolyte solution supply unit and a cathode-side gas-liquid separator. Among the components constituting the cathode compartment 20, components similar to those constituting the anode compartment 10 will not be described.

[0721] (Cathode)

When the electrode for electrolysis of the present embodiment is not inserted on the cathode side, the cathode 21 is in the frame of the cathode chamber 20 (i.e., in the cathode frame). Cathode 21 preferably has a nickel substrate and a catalyst layer that covers the nickel substrate. Examples of catalyst bed components include elements such as Ru, C, Si, P, S, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Rh, Pd , Ag, Cd, In, Sn, Ta, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho , Er, Tm, Yb and Lu, as well as oxides and hydroxides of these metals. Examples of the method for forming the catalyst layer include electrodeposition, alloy electrodeposition, dispersion / composite electrodeposition, CVD, FOPP, pyrolysis, and sputtering. These methods can be used in combination. The catalyst bed can have multiple layers and multiple elements as needed. The cathode 21 can be subjected to a reduction treatment, if necessary. Nickel, nickel alloys and nickel-plated iron or stainless steel can be used as the substrate for the cathode 21.

As for the shape, any of a perforated metal sheet, a nonwoven fabric, a porous metal, an expanded metal sheet, an electrospinning metal porous foil, a so-called woven metal mesh formed by interlacing of thin metal filaments, and the like can be used.

[0722] (Cathode Supply Conductor)

When the electrode for electrolysis of the present embodiment is inserted on the cathode side, a cathode supply conductor 21 is provided in the frame of the cathode chamber 20. The cathode supply conductor 21 may be coated with a catalyst component. The catalyst component can be a component that is initially used as a cathode and is stored. Examples of catalyst bed components include elements such as Ru, C, Si, P, S, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Rh, Pd , Ag, Cd, In, Sn, Ta, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho , Er, Tm, Yb and Lu, as well as oxides and hydroxides of these metals. Examples of the method for forming the catalyst layer include electrodeposition, alloy electrodeposition, dispersion / composite electrodeposition, CVD, FOPP, pyrolysis, and sputtering. These methods can be used in combination. The catalyst bed can have multiple layers and multiple elements as needed. Nickel, nickel alloys and nickel-plated iron or stainless steel without catalytic coating can be used. Nickel, nickel alloys and nickel-plated iron or stainless steel can be used as the substrate for the cathode supply conductor 21.

As for the shape, any of a perforated metal sheet, a nonwoven fabric, a porous metal, an expanded metal sheet, an electrospinning metal porous foil, a so-called woven metal mesh formed by interlacing of thin metal filaments, and the like can be used.

[0723] (Reverse current absorbing layer)

As the material for the layer that absorbs the reverse current, a material that is less noble in terms of the redox potential than the redox potential of the element for the aforementioned catalyst layer of the cathode can be selected. Examples include nickel and iron.

[0724] (Down conductor)

The cathode chamber 20 preferably contains a current collector 23. The current collector 23 improves the efficiency of current extraction. In the present embodiment, the collector 23 is a porous plate and is preferably disposed substantially parallel to the surface of the cathode 21.

[0725] The collector 23 preferably contains an electrically conductive metal such as nickel, iron, copper, silver and titanium. The current collector 23 can be a mixture, alloy or complex oxide of these metals. The collector 23 may be of any shape as long as the shape allows the collector to function and may be in the form of a plate or mesh.

[0726] (Metallic elastic body)

By placing the metal elastic body 22 between the current collector 23 and the cathode 21, each cathode 21 of a plurality of electrolytic cells 1 connected in series is pressed against the ion exchange membrane 2 to shorten the distance between each anode 11 and each cathode 21. Thus, it is possible to reduce the voltage applied to the entire plurality of electrolytic cells connected in series. cells 1. Reducing voltage helps to reduce power consumption. When the metal resilient body 22 is placed, the pressing pressure generated by the metal resilient body 22 allows the electrolysis electrode to stably maintain its position in place when the laminated article containing the electrolysis electrode in the present embodiment is placed in the electrolytic cell.

[0727] As the metal resilient body 22, spring members such as coil and coil springs and damping mats can be used. As the metal elastic body 22, an element can be appropriately applied in consideration of mechanical stress due to pressure on the ion exchange membrane and the like. The metal resilient body 22 may be located on the surface of the collector 23 on the side of the cathode chamber 20, or may be provided on the surface of the partition wall on the side of the anode chamber 10. The two chambers are usually separated so that the cathode chamber 20 becomes smaller than the anode chamber 10. Thus In terms of frame strength and the like, the metal resilient body 22 is preferably placed between the collector 34 and the cathode 21 in the cathode chamber 20. The metal resilient body 22 preferably contains an electrically conductive metal such as nickel, iron, copper, silver and titanium.

[0728] (Holder)

The cathode chamber 20 preferably comprises a holder 24 which electrically connects the collector 23 to the baffle 30. This can achieve an efficient current flow.

[0729] The holder 24 preferably contains an electrically conductive metal such as nickel, iron, copper, silver, and titanium. The holder 24 can be of any shape as long as the holder can support the collector 23 and can be in the form of a rod, plate, or mesh. The holder 24 is in the form of a plate, for example. A plurality of holders 24 are disposed between the baffle 30 and the down conductor 23. The plurality of holders 24 are aligned so that their surfaces are parallel to each other. The holders 24 are located substantially perpendicular to the baffle 30 and the down conductor 23.

[0730] (Anode side seal and cathode side seal)

The anode side seal is preferably located on the surface of the frame constituting the anode chamber 10. The cathode side seal is preferably positioned on the surface of the frame constituting the cathode compartment 20. The electrolytic cells are interconnected so that the anode side seal located in one electrolytic cell and the cathode side seal the adjacent electrolytic cell is laid with an ion exchange membrane 2 (see Figure 92). These seals can create airtightness at the junctions when a plurality of electrolytic cells 1 are connected in series through an ion exchange membrane 2.

[0731] The seals form a seal between the ion exchange membrane and the electrolytic cells. Specific examples of seals include picture frame-like rubber sheets in the center of which an opening is formed. The seals must be resistant to corrosive electrolyte solutions or generated gas and be functional for a long period of time. Thus, with regard to chemical resistance and hardness, vulcanized products and peroxide-crosslinked products of ethylene-propylene-diene rubber (EPDM-rubber) and ethylene-propylene rubber (EPM-rubber) are usually used as seals. Alternatively, if necessary, seals can be used in which the area in contact with the liquid (the area in contact with the liquid) is coated with a fluorine resin such as polytetrafluoroethylene (PTFE) and copolymers of tetrafluoroethylene and perfluoroalkyl vinyl ethers (PFA). These seals may in each case have an opening that does not impede the flow of the electrolyte solution, and the shape of the opening is not particularly limited. For example, a seal in the form of a picture frame is attached by means of an adhesive or the like along the peripheral edge of each opening of the anode chamber frame constituting the anode compartment 10 or the cathode compartment frame constituting the cathode compartment 20. Then, for example, in the case where two electrolytic cells 1 are connected through an ion exchange membrane 2 (see Figure 92), each electrolytic cell 1 to which a seal is attached must be sealed by means of an ion exchange membrane 2. This seal can prevent electrolyte solution, alkali metal hydroxide, chlorine gas, hydrogen gas from escaping from the electrolytic cells 1 and the like formed by electrolysis.

[0732] [Winding Application Phase]

The coil in the present embodiment may be an electrolysis electrode in the form of a coil, or may be a laminated article of an electrolysis electrode and a new membrane in the form of a coil. The method for manufacturing an electrolytic cell of the present embodiment employs a winding. Specific examples of the step of applying the winding include, but are not limited to, a method in which first, in an existing electrolysis cell, adjacent electrolytic cells and an ion exchange membrane are released from a fixed state using a pressing device, providing a gap between the electrolytic cell and the ion exchange membrane, then the electrolysis electrode located in the form of a winding, after its unwinding, is inserted into the gap, and the elements are connected again by means of a clamping device. In the case where a laminated article in the form of a winding is used, examples of the method include a method in which after a gap is formed between the electrolytic cell and the ion exchange membrane as described above, the existing ion exchange membrane to be renewed is removed, then the laminated article located in the form of a winding, after its unwinding, is inserted into the gap, and the elements are connected again with the help of a clamping device. By this method, an electrolysis electrode or laminated article can be placed on the surface of the anode or cathode of an existing electrolyzer and the characteristics of the ion exchange membrane and the anode and / or cathode can be restored.

As described above, in the present embodiment, the step of applying the coil preferably comprises a step (B) of releasing the coil from the wound state, and after step (B) more preferably has the step (C) of placing an electrolysis electrode or laminated article on the surface of at least one of anode and cathode.

[0733] In the present embodiment, the step of applying the winding preferably has the step (A) of holding the electrolysis electrode or the laminated article in a wound state, thereby obtaining a winding. In step (A), the electrolysis electrode or laminate as such may be wound to form a coil, or the electrolysis electrode or laminated product may be wound around the sleeve (core) to form a coil. As the sleeve that can be used here, which is not particularly limited, for example, an element having a substantially cylindrical shape and having a size corresponding to an electrolysis electrode or a laminated article can be used.

[0734] [Electrolysis Electrode]

In the present embodiment, the electrode for electrolysis is not particularly limited as long as the electrode is used as a winding as mentioned above, that is, it is windable. The electrolysis electrode can be an electrode that serves as a cathode in electrolysis, or it can be an electrode that serves as an anode. With regard to the material, shape and the like of the electrode for electrolysis, those suitable for forming the winding can be appropriately selected in consideration of the step of applying the winding, the configuration of the electrolysis cell, and the like in the present embodiment. Preferred aspects of the electrolysis electrode in the present embodiment will be described below, but they are only exemplary aspects preferable for forming a coil. Electrolysis electrodes other than the following aspects can be appropriately used.

[0735] The electrode for electrolysis in the present embodiment has a force applied per unit mass · unit area, preferably 1.6 N / (mg · cm ² ) or less, more preferably less than 1.6 N / (mg · cm ² ) , further preferably less than 1.5 N / (mg cm ² ), even more preferably 1.2 N / (mg cm ² ) or less, even more preferably 1.20 N / (mg cm ² ) or less with from the point of view of providing good workability and good adhesion to a membrane such as an ion exchange membrane and a microporous membrane, with a supply conductor (a worn electrode and an electrode not having a catalytic coating) and the like. The applied force is even more preferably 1.1 N / (mg cm ² ) or less, further more preferably 1.10 N / (mg cm ² ) or less, even more preferably 1.0 N / (mg cm ²⁾ ) or less, even more preferably 1.00 N / (mg · cm ² ) or less.

From the viewpoint of further improving the electrolysis productivity, the force is preferably more than 0.005 N / (mg cm ² ), more preferably 0.08 N / (mg cm ² ) or more, further preferably 0.1 N / (mg cm ² ) or more, even more preferably 0.14 N / (mg · cm ² ) or more. Even more preferably, the force is 0.2 N / (mg · cm ² ) or more from the viewpoint of further facilitating the handling of a large size (eg, 1.5 mx 2.5 m).

The above-described applied force may be within the above-described range by appropriately adjusting, for example, the below-described open porosity ratio, electrode thickness, arithmetic mean of surface roughness, and the like. For example, more specifically, a higher open porosity ratio results in a lower applied force, and a lower open porosity ratio results in a higher applied force.

The mass per unit area is preferably 48 mg / cm ² or less, more preferably 30 mg / cm ² or less, even more preferably 20 mg / cm ² or less from the standpoint of providing good processability and good adhesion to the membrane, such as an ion exchange membrane and a microporous membrane, with a worn electrode, with a feed conductor not having a catalytic coating, and economy, and moreover, is preferably 15 mg / cm ² or less, for general reasons including manufacturability, adhesion strength and economy. The lower limit is not particularly limited, but is, for example, on the order of 1 mg / cm ² .

The above-described mass per unit area may be within the above-described range, for example, by appropriately adjusting the below-described open porosity ratio, electrode thickness, and the like. More specifically, for example, when the thickness is constant, a higher open porosity ratio results in a decrease in mass per unit area, and a lower open porosity ratio results in a higher mass per unit area.

[0736] The applied force can be measured by methods (i) or (ii) described below, which are set out in more detail in the Examples. With regard to the applied force, the value obtained by measurement by method (i) (also called “applied force (1)” ") and the value obtained by measurement by method (ii) (also called" applied force (2) ”") , can be the same or different, and each of the values is preferably less than 1.5 N / (mg · cm ² ).

[0737] [Method (i)]

Nickel plate blasted with alumina 320 grit (thickness 1.2 mm, square with side 200 mm), ion-exchange membrane obtained by applying particles of inorganic material and a binder to both surfaces of a perfluorocarbon polymer into which an ion-exchange group is introduced (square with a side of 170 mm, the details of the ion exchange membrane specified here are described in the Examples), and a sample electrode (square with a side of 130 mm) is layered in that order. Thereafter, the laminated product is sufficiently immersed in clean water, and excess water deposited on the surface of the laminated product is removed to obtain a sample for measurement. The arithmetic mean (Ra) of the surface roughness of a nickel plate after blasting is 0.5 to 0.8 μm. A specific method for calculating the arithmetic mean (Ra) of the surface roughness is as described in the Examples.

Under the condition of temperature 23 ± 2 ° C and relative humidity 30 ± 5%, only the electrode sample in this measurement sample is lifted in the vertical direction at a speed of 10 mm / minute using a tensile compression machine and the load is measured when the electrode sample is lifted 10 mm vertically. This measurement is repeated three times and the average is calculated.

This average value is divided by the area of the overlapping area of the electrode sample and the ion exchange membrane and by the mass of the ion exchange membrane in the area of overlapping with the electrode sample to calculate the applied force per unit mass · unit area (1) (N / (mg · cm ² )).

[0738] The applied force per unit mass · unit area (1) obtained by method (i) is preferably 1.6 N / (mg · cm ² ) or less, more preferably less than 1.6 N / (mg · cm ² ), further preferably less than 1.5 N / (mg cm ² ), even more preferably 1.2 N / (mg cm ² ) or less, even more preferably 1.20 N / (mg cm ² ) or less in terms of providing good processability and good adhesion to a membrane such as an ion exchange membrane or a microporous membrane, a worn electrode, and an uncatalyzed supply conductor. The applied force is even more preferably 1.1 N / (mg cm ² ) or less, further more preferably 1.10 N / (mg cm ² ) or less, particularly preferably 1.0 N / (mg cm ² ) or less, particularly preferably 1.00 N / (mg · cm ² ) or less. The force is preferably more than 0.005 N / (mg cm ² ), more preferably 0.08 N / (mg cm ² ) or more, further preferably 0.1 N / (mg cm ² ) or more in view of further improvement electrolysis productivity, and, moreover, more preferably 0.14 N / (mg cm ² ), even more preferably 0.2 N / (mg cm ² ) or more from the standpoint of further facilitating handling of loading and unloading at a large size (for example, size 1.5 mx 2.5 m).

[0739] [Method (ii)]

A nickel plate blasted with alumina 320 grit (thickness 1.2 mm, square with a side of 200 mm, a nickel plate similar to the plate in the above method (i)), and an electrode sample (square with a side of 130 mm) is layered in this okay. Thereafter, the laminated product is sufficiently immersed in clean water, and excess water deposited on the surface of the laminated product is removed to obtain a sample for measurement. Under the condition of temperature 23 ± 2 ° C and relative humidity 30 ± 5%, only the electrode sample in this measurement sample is lifted in the vertical direction at a speed of 10 mm / minute using a tensile compression machine and the load is measured when the electrode sample is lifted 10 mm vertically. This measurement is repeated three times and the average is calculated.

This average value is divided by the area of the overlapping area of the electrode sample and the nickel plate and by the weight of the electrode sample in the overlapping area with the nickel plate to calculate the applied force per unit mass · unit area (2) (N / (mg · cm ² )).

[0740] The applied force per unit mass · unit area (2) obtained by method (ii) is preferably 1.6 N / (mg · cm ² ) or less, more preferably less than 1.6 N / (mg · cm ² ), further preferably less than 1.5 N / (mg cm ² ), even more preferably 1.2 N / (mg cm ² ) or less, even more preferably 1.20 N / (mg cm ² ) or less in terms of providing good processability and good adhesion to a membrane such as an ion exchange membrane or a microporous membrane, a worn electrode, and an uncatalyzed supply conductor. The applied force is even more preferably 1.1 N / (mg cm ² ) or less, further more preferably 1.10 N / (mg cm ² ) or less, particularly preferably 1.0 N / (mg cm ² ) or less, particularly preferably 1.00 N / (mg · cm ² ) or less. In addition, the force is preferably more than 0.005 N / (mg cm ² ), more preferably 0.08 N / (mg cm ² ) or more, further preferably 0.1 N / (mg cm ² ) or more from the point in view of further improving the electrolysis productivity, and, moreover, is more preferably 0.14 N / (mg cm ² ) or more from the standpoint of further facilitating the handling of a large size (for example, 1.5 m × 2.5 m).

[0741] The electrolysis electrode of the present embodiment preferably comprises an electrolysis electrode support and a catalyst layer. The thickness of the electrode substrate for electrolysis (measured thickness) is, but is not particularly limited, preferably 300 μm or less, more preferably 205 μm or less, even more preferably 155 μm or less, further preferably 135 μm or less, even more preferably 125 μm or less, even more preferably 120 μm or less, even more preferably 100 μm or less from the point of view of ensuring good processability, achieving good adhesion to a membrane such as an ion exchange membrane or a microporous membrane, with a worn electrode (supply conductor) and an electrode ( feed conductor), which does not have a catalytic coating, being suitable for roll-up and satisfactory folding into folds and facilitates loading and unloading at a large size (for example, size 1.5 mx 2.5 m), and, in addition, still more preferably 50 µm or less in terms of processability and economy. The lower limit is not particularly limited, but is, for example, 1 µm, preferably 5 µm, more preferably 15 µm.

[0742] The proportion measured by the following method (2) on the electrode for electrolysis in the present embodiment is not particularly limited, but is preferably 90% or more, more preferably 92% or more from the viewpoint of ensuring good workability and achieving good adhesion strength with membrane, such as an ion exchange membrane or a microporous membrane, with a worn electrode (supply conductor) and an electrode (supply conductor) not having a catalytic coating, and additionally preferably 95% or more from the point of view of further facilitating loading and unloading at a large size (for example , size 1.5 m × 2.5 m). The upper limit value is 100%.

[Method (2)]

An ion exchange membrane (170 mm square) and an electrode sample (130 mm square) are layered in this order. The laminated product is placed on the curved surface of a polyethylene pipe (outer diameter: 280 mm) so that the electrode sample in this laminated product is positioned outside at a temperature of 23 ± 2 ° C and a relative humidity of 30 ± 5%, the laminated product and the pipe are sufficiently immersed into clean water, remove the excess water deposited on the surface of the laminated product and the pipe, and then, one minute after this removal, measure the fraction (%) of the area of the area in which the ion-exchange membrane (square with a side of 170 mm) is in close contact with electrode.

[0743] The proportion measured by the following method (3) on the electrode for electrolysis in the present embodiment is not particularly limited, but is preferably 75% or more, more preferably 80% or more from the viewpoint of ensuring good workability, achieving good adhesion strength with membrane, such as an ion exchange membrane or a microporous membrane, with a worn electrode (supply conductor) and an electrode (supply conductor) not having a catalytic coating, and for proper roll-winding and satisfactory creasing, and is additionally preferably 90% or more from the point of view of additional facilitation of loading and unloading at a large size (for example, size 1.5 m × 2.5 m). The upper limit value is 100%.

[Method (3)]

An ion exchange membrane (170 mm square) and an electrode sample (130 mm square) are layered in this order. The laminated product is placed on the curved surface of a polyethylene pipe (outer diameter: 145 mm) so that the electrode sample in this laminated product is positioned externally at a temperature of 23 ± 2 ° C and a relative humidity of 30 ± 5%, the laminated product and the pipe are sufficiently immersed into clean water, remove the excess water deposited on the surface of the laminated product and the pipe, and then, one minute after this removal, measure the fraction (%) of the area of the area in which the ion-exchange membrane (square with a side of 170 mm) is in close contact with electrode.

[0744] The electrode for electrolysis in the present embodiment has, but is not limited to, a porous structure and an open porosity ratio or void ratio of 5 to 90% or less in terms of ensuring good workability, achieving good adhesion to the membrane, such as an ion exchange membrane or microporous membrane, with a worn electrode (supply conductor) and an electrode (supply conductor) not having a catalytic coating, and preventing the accumulation of gas evolved during electrolysis, although not specifically limited thereto. The open porosity ratio is more preferably 10 to 80% or less, more preferably 20 to 75%.

The open porosity ratio is the fraction of the lumen areas per unit volume. The calculation method may differ depending on whether sub-micron-sized gaps are considered or only visible gaps are considered. In the present embodiment, the volume V was calculated from the values of the measured thickness, the width and the length of the electrode, and in addition, the weight W was measured to thereby calculate the open porosity coefficient A by the following formula.

A = (1– (W / (V × ρ)) × 100

ρ is the density of the electrode material (g / cm ³ ). For example, the ρ of nickel is 8.908 g / cm ³ and the ρ of titanium is 4.506 g / cm ³ . The open porosity ratio is appropriately controlled by changing the area of perforated metal per unit area in the case of a perforated metal sheet, changing the values of SW (short diameter), LW (long diameter), and feed in the case of expanded metal sheet, changing the linear dimensions of the diameter of the metal fiber, and sieve numbers in the case of a mesh, a change in the photoresist pattern used in the case of electrospinning, a change in the diameter of the metal fiber and the density of the fiber in the case of a nonwoven fabric, a change in the mold for forming cavities in the case of a porous metal, or the like.

[0745] Hereinafter, a more specific embodiment of the electrode for electrolysis in the present embodiment will be described.

The electrolysis electrode of the present embodiment preferably comprises an electrolysis electrode support and a catalyst layer. The catalyst bed can be composed of multiple layers, as shown below, or can have a single layer configuration.

As shown in FIG. 96, the electrolysis electrode 100 of the present embodiment includes an electrolysis electrode substrate 10 and a pair of first layers 20 that cover both surfaces of the electrolysis electrode substrate 10. The first layers 20 preferably cover the entire electrode substrate 10 for electrolysis. Apparently, this coating increases the catalytic activity and durability of the electrode. One first layer 20 can only be laminated to one surface of the electrolysis electrode substrate 10.

In addition, as shown in Figure 96, the surfaces of the first layers 20 may be coated with the second layers 30. The first layers 20 are preferably covered with the second layers 30 in their entirety. Alternatively, one second layer 30 may be laminated to only one surface of the first layer 20.

[0746] (Electrode support for electrolysis)

As the electrode substrate 10 for electrolysis, for example, nickel, nickel alloys, stainless steel, and, in addition, valve metals, including titanium, can be used, although not limited thereto. Substrate 10 preferably contains at least one element selected from nickel (Ni) and titanium (Ti).

When stainless steel is used in an aqueous alkali solution of high concentration, iron and chromium are washed out and the electrical conductivity is in the order of one tenth that of nickel. In view of the above, as the electrode substrate for electrolysis, a substrate containing nickel (Ni) is preferable.

Alternatively, when the electrode substrate 10 for electrolysis is used in a brine with a high concentration close to saturation, in an atmosphere in which chlorine gas is generated, the material of the electrode substrate 10 is also preferably titanium having high corrosion resistance.

The shape of the electrode substrate 10 for electrolysis is not particularly limited, and a shape suitable for this purpose can be selected. As the mold, any of a perforated metal sheet, a nonwoven fabric, a porous metal, an expanded metal sheet, an electrospinning metal porous foil, a so-called woven metal mesh, and the like can be used. Of these, perforated metal sheet or expanded metal sheet is preferable. Electrospinning is a method of producing a thin metal foil having a precisely shaped pattern using photolithography and electrodeposition in combination. It is a method involving patterning a substrate with a photoresist and electrodeposition of a portion not protected by the resist to form a metal thin film.

With regard to the shape of the electrode support for electrolysis, a suitable specification depends on the distance between the anode and the cathode in the electrolysis cell. In the case where the distance between the anode and the cathode is finite, the shape of an expanded metal sheet or a perforated metal sheet can be used, and in the case of a so-called zero-gap electrolyzer in which the ion exchange membrane is in contact with the electrode, a formed interlacing of fine metal filaments woven metal mesh, wire mesh, porous metal, metal nonwoven fabric, expanded metal sheet, perforated metal sheet, metal porous foil, and the like, although not limited thereto.

Examples of the electrode substrate 10 for electrolysis include metal porous foil, wire mesh, metal nonwoven fabric, perforated metal sheet, expanded metal sheet, and porous metal.

As the plate material before being processed to form a perforated metal sheet or expanded metal sheet, rolled plate materials and electrolytic foils are preferred. The electrolytic foil is preferably subjected to a further electrodeposition treatment using the same element as its base material as a further treatment to thereby form roughness on one or both of its surfaces.

The thickness of the electrolysis electrode substrate 10 as mentioned above is preferably 300 µm or less, more preferably 205 µm or less, further preferably 155 µm or less, even more preferably 135 µm or less, even more preferably 125 µm or less, even more preferably 120 µm or less, even more preferably 100 µm or less, and further even more preferably 50 µm or less in terms of processability and economy. The lower limit is not particularly limited, but is, for example, 1 µm, preferably 5 µm, more preferably 15 µm.

[0747] In the electrolysis electrode substrate, residual stress during processing is preferably relieved by annealing the electrolysis electrode substrate in an oxidizing atmosphere. It is preferable to form roughness using a steel grid, an alumina grid or the like on the surface of the electrode substrate for electrolysis, followed by acid treatment to increase its surface area in order to improve adhesion to the catalyst layer that is coated on the surface. Alternatively, it is preferable to carry out the electrodeposition treatment using the same element as the substrate to increase the surface area.

[0748] To bring the first layer 20 into intimate contact with the surface of the electrolysis electrode substrate 10, the electrolysis electrode substrate 10 is preferably subjected to a surface area increase treatment. Examples of surface area enhancing treatments include chopped wire blasting, steel grating, alumina grating or the like, acidizing using sulfuric acid or hydrochloric acid, and electrodeposition using the same element as in the substrate. The arithmetic mean (Ra) of the surface roughness on the surface of the substrate is not particularly limited, but is preferably 0.05 µm to 50 µm, more preferably 0.1 to 10 µm, even more preferably 0.1 to 8 µm.

[0749] Next, a case will be described where the electrolysis electrode of the present embodiment is used as an anode for conventional salt electrolysis.

(First layer)

In Figure 96, the first layer 20 contains at least one of ruthenium oxides, iridium oxides and titanium oxides as a catalyst layer. Examples of ruthenium oxide include RuO ₂ . Examples of iridium oxide include IrO ₂ . Examples of titanium oxide include TiO ₂ . The first layer 20 preferably contains two oxides: ruthenium oxide and titanium oxide, or three oxides: ruthenium oxide, iridium oxide and titanium oxide. This makes the first layer 20 more stable and further improves the adhesion to the second layer 30.

[0750] When the first layer 20 contains two oxides: ruthenium oxide and titanium oxide, the first layer 20 preferably contains from 1 to 9 moles, more preferably from 1 to 4 moles of titanium oxide, based on 1 mole of ruthenium oxide contained in the first layer 20 With the compositional ratio of the two oxides in this range, the electrolysis electrode 100 exhibits excellent resistance.

[0751] When the first layer 20 contains three oxides: ruthenium oxide, iridium oxide and titanium oxide, the first layer 20 preferably contains 0.2 to 3 moles, more preferably 0.3 to 2.5 moles of iridium oxide per 1 mol of ruthenium oxide contained in the first layer 20. The first layer 20 preferably contains from 0.3 to 8 moles, more preferably from 1 to 7 moles of titanium oxide, based on 1 mole of ruthenium oxide contained in the first layer 20. With a compositional ratio of three oxides in this range, the electrolysis electrode 100 exhibits excellent resistance.

[0752] When the first layer 20 contains at least two of ruthenium oxide, iridium oxide and titanium oxide, these oxides preferably form a solid solution. The formation of a solid solution of the oxides allows the electrolysis electrode 100 to exhibit excellent resistance.

[0753] In addition to the above-described compositions, oxides of various compositions can be used, provided that at least one of ruthenium oxide, iridium oxide, and titanium oxide is contained. For example, an oxide coating called DSA (R), which contains ruthenium, iridium, tantalum, niobium, titanium, tin, cobalt, manganese, platinum, and the like, can be used as the first layer 20.

[0754] The first layer 20 need not be a single layer and may include multiple layers. For example, the first layer 20 may include a three-oxide layer and a two-oxide layer. The thickness of the first layer 20 is preferably 0.05 to 10 µm, more preferably 0.1 to 8 µm.

[0755] (Second layer)

The second layer 30 preferably contains ruthenium and titanium. This makes it possible to further reduce the electrical overvoltage of chlorine immediately after electrolysis.

[0756] The second layer 30 preferably contains palladium oxide, a solid solution of palladium and platinum oxide, or an alloy of palladium and platinum. This makes it possible to further reduce the electrical overvoltage of chlorine immediately after electrolysis.

[0757] The thicker second layer 30 can maintain the electrolysis performance for a long period of time, but from the viewpoint of economy, the thickness is preferably 0.05 to 3 µm.

[0758] Next, a situation will be described where the electrolysis electrode in the present embodiment is used as a cathode for conventional salt electrolysis.

(First layer)

Examples of the components of the first layer 20 as a catalyst layer include elements such as C, Si, P, S, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, In, Sn, Ta, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu, as well as metal oxides and hydroxides.

The first layer 20 may or may not contain at least one of platinum group metals, platinum group metal oxides, platinum group metal hydroxides, and platinum group metal containing alloys.

When the first layer 20 contains at least one of platinum group metals, platinum group metal oxides, platinum group metal hydroxides and alloys containing a platinum group metal, platinum group metals, platinum group metal oxides, platinum group metal hydroxides, and platinum metal containing alloys the groups preferably contain at least one platinum group metal from platinum, palladium, rhodium, ruthenium and iridium.

The platinum group metal is preferably platinum.

As the oxide of the platinum group metal, ruthenium oxide is preferably contained.

As the hydroxide of the platinum group metal, ruthenium hydroxide is preferably contained.

As an alloy of platinum group metals, an alloy of platinum with nickel, iron and cobalt is preferably included.

In addition, if necessary, an oxide or hydroxide of a lanthanide element is preferably contained as the second component. This allows the electrolysis electrode 100 to exhibit excellent resistance.

As the oxide or hydroxide of the lanthanide element, preferably at least one selected from lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium and dysprosium is contained.

In addition, if necessary, a transition metal oxide or hydroxide is preferably contained as the third component.

The addition of the third component allows the electrolysis electrode 100 to exhibit superior resistance and lower electrolysis voltage.

Examples of a preferred combination include only ruthenium, ruthenium + nickel, ruthenium + cerium, ruthenium + lanthanum, ruthenium + lanthanum + platinum, ruthenium + lanthanum + palladium, ruthenium + praseodymium, ruthenium + praseodymium + platinum, ruthenium + praseodymium + platinum + palladium, ruthenium + neodymium, ruthenium + neodymium + platinum, ruthenium + neodymium + manganese, ruthenium + neodymium + iron, ruthenium + neodymium + cobalt, ruthenium + neodymium + zinc, ruthenium + neodymium + gallium, ruthenium + neodymium + sulfur, ruthenium + neodymium + lead , ruthenium + neodymium + nickel, ruthenium + neodymium + copper, ruthenium + samarium, ruthenium + samarium + manganese, ruthenium + samarium + iron, ruthenium + samarium + cobalt, ruthenium + samarium + zinc, ruthenium + samarium + gallium, ruthenium + samarium + sulfur, ruthenium + samarium + lead, ruthenium + samarium + nickel, platinum + cerium, platinum + palladium + cerium, platinum + palladium + lanthanum + cerium, platinum + iridium, platinum + palladium, platinum + iridium + palladium, platinum + nickel + palladium, platinum + nickel + ruthenium, platinum and nickel alloys, platinum and cobalt alloys and platinum and iron alloys.

When platinum-group metals, platinum-group metal oxides, platinum-group metal hydroxides, and platinum-group metal-containing alloys are not contained, the main component of the catalyst is preferably the element nickel.

Preferably, at least one of nickel metal, nickel oxides and hydroxides is contained.

A transition metal can be added as a second component. As the second added component, at least one of titanium, tin, molybdenum, cobalt, manganese, iron, sulfur, zinc, copper and carbon is preferably contained.

Examples of a preferred combination include nickel + tin, nickel + titanium, nickel + molybdenum, and nickel + cobalt.

If necessary, an intermediate layer may be disposed between the first layer 20 and the electrolysis electrode substrate 10. By placing the intermediate layer, the resistance of the electrolysis electrode 100 can be improved.

Preferred as the intermediate layer are those which have an affinity for both the first layer 20 and the electrode substrate 10 for electrolysis. As the intermediate layer, preferred are nickel oxides, platinum group metals, platinum group metal oxides and platinum group metal hydroxides. The intermediate layer can be formed by applying and firing a solution containing the component that forms the intermediate layer. Alternatively, a surface oxide layer can also be formed by subjecting the substrate to heat treatment at a temperature of 300 to 600 ° C. in an air atmosphere. In addition, this layer can be formed by a known method such as a thermal spraying method and an ionic deposition method.

[0759] (Second layer)

Examples of the components of the first layer 30 as a catalyst layer include elements such as C, Si, P, S, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, In, Sn, Ta, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu, as well as metal oxides and hydroxides.

The first layer 30 may or may not contain at least one of platinum group metals, platinum group metal oxides, platinum group metal hydroxides, and platinum group metal containing alloys. Examples of a preferred combination of elements contained in the second layer include those listed for the first layer. The combination of the first layer and the second layer can be a combination in which the compositions are the same and the compositional ratios are different, or it can be a combination of different compositions.

[0760] With regard to the thickness of the catalyst layer, the total thickness of the formed catalyst layer and the intermediate layer is preferably 0.01 µm to 20 µm. With a thickness of 0.01 µm or more, the catalyst layer can sufficiently serve as a catalyst. With a thickness of 20 µm or less, a strong catalyst layer can be formed that is unlikely to separate from the support. The thickness is more preferably 0.05 µm to 15 µm. The thickness is more preferably 0.1 to 10 µm. Even more preferably, the thickness is 0.2 to 8 µm.

[0761] The thickness of the electrode, that is, the combined thickness of the electrolysis electrode support and the catalyst layer, is preferably 315 µm or less, more preferably 220 µm or less, further preferably 170 µm or less, even more preferably 150 µm or less, particularly preferably 145 µm or less, even more preferably 140 µm or less, even more preferably 138 µm or less, further even more preferably 135 µm or less, with respect to the workability of the electrode. A thickness of 135 µm or less can provide good workability. In addition, for similar reasons as above, the thickness is preferably 130 µm or less, more preferably less than 130 µm, even more preferably 115 µm or less, further more preferably 65 µm or less. The lower limit is not particularly limited, but is preferably 1 µm or more, more preferably 5 µm or more for practical reasons, more preferably 20 µm or more. The thickness of the electrode can be determined by measuring with a digital thickness gauge (from Mitutoyo Corporation, minimum scale 0.001 mm). The thickness of the substrate of the electrolysis electrode can be measured in the same manner as in the case of the electrode. The thickness of the catalyst layer can be determined by subtracting the thickness of the electrolysis electrode support from the thickness of the electrode.

[0762] In the present embodiment, the electrode for electrolysis preferably contains at least one catalyst component selected from the group consisting of Ru, Rh, Pd, Ir, Pt, Au, Ti, V, Cr, Mn, Fe, Co, Ni , Cu, Zn, Y, Zr, Nb, Mo, Ag, Ta, W, Re, Os, Al, In, Sn, Sb, Ga, Ge, B, C, N, O, Si, P, S, La , Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb and Dy, from the standpoint of achieving sufficient electrolysis performance.

[0763] In the present embodiment, from the considerations that the electrode for electrolysis of the present embodiment, if it is an electrode having a wide elastic deformation range, can provide better workability and has better adhesion to a membrane such as an ion exchange membrane or microporous membrane, with a worn electrode, with a supply conductor not having a catalytic coating, and the like, the thickness of the electrode for electrolysis is preferably 315 μm or less, more preferably 220 μm or less, even more preferably 170 μm or less, even more preferably 150 µm or less, particularly preferably 145 µm or less, even more preferably 140 µm or less, further even more preferably 138 µm or less, even more preferably 135 µm or less. A thickness of 135 µm or less can provide good workability. In addition, for reasons similar to the above, the thickness is preferably 130 µm or less, more preferably less than 130 µm, further preferably 115 µm or less, even more preferably 65 µm or less. The lower limit is not particularly limited, but is preferably 1 µm or more, more preferably 5 µm or more for practical reasons, more preferably 20 µm or more. In the present embodiment, “having a wide elastic range” means that when the electrolysis electrode is wound to form a winding, it is unlikely that winding-induced warping will occur after being released from the wound state. The thickness of the electrolysis electrode when the below-mentioned catalyst layer is provided refers to the total thickness of both the electrolysis electrode support and the catalyst layer.

[0764] (Method for Manufacturing Electrolysis Electrode)

Next, one embodiment of a method for manufacturing an electrode 100 for electrolysis will be described in detail.

In the present embodiment, the electrolysis electrode 100 can be obtained by forming a first layer 20, preferably a second layer 30 on the electrolysis electrode substrate by a method such as firing a coating film in an oxygen atmosphere (pyrolysis) or ion deposition, electrodeposition, or thermal sputtering. The production method of the present embodiment as mentioned above can achieve high formation productivity of the electrolysis electrode 100. More specifically, a catalyst layer is formed on the electrode support for electrolysis by an application step in which a coating liquid containing the catalyst is applied, a drying step in which the coating liquid is dried, and a pyrolysis step in which pyrolysis is performed. Pyrolysis here means that a metal salt, which is to be a precursor, decomposes by heating into a metal or metal oxide and a gaseous substance. The decomposition product depends on the nature of the metal used, the type of salt and the atmosphere in which the pyrolysis is carried out, and many metals tend to form oxides in an oxidizing atmosphere. In the industrial process for making an electrode, pyrolysis is usually performed in air and in many cases a metal oxide or metal hydroxide is formed.

[0765] (Formation of the first layer of the anode)

(Application stage)

The first layer 20 is obtained by applying a solution in which at least one metal salt of ruthenium, iridium and titanium (first coating liquid) is dissolved on the electrode substrate for electrolysis, and then pyrolysis (calcining) the coating liquid in the presence of oxygen. The content of ruthenium, iridium and titanium in the first cover liquid is substantially equivalent to that in the first layer 20.

[0766] The metal salts can be chlorides, nitrates, sulfates, metal alkoxides, and any other form. The solvent of the first coating liquid can be selected depending on the type of metal salt, and water and alcohols such as butanol can be used. As the solvent, water or a mixed solvent of water and alcohol is preferred. The total metal concentration in the first coating liquid in which the metal salts are dissolved is not particularly limited, but is preferably in the range of 10 to 150 g / L in consideration of the thickness of the coating film formed by a single application.

[0767] Examples of the method used as the method for applying the first coating liquid to the electrolysis electrode substrate 10 include a method of dipping the electrolysis electrode substrate 10 into the first coating liquid, a method for applying the first coating liquid with a brush, a rolling method using a sponge roller impregnated a first coating liquid, and an electrostatic coating method in which the electrode substrate 10 for electrolysis and the first coating liquid are charged with opposite charges and sputtering is performed. Among them, a rolling method or an electrostatic coating method is preferable, which has excellent production performance on an industrial scale.

[0768] (Drying Step and Pyrolysis Step)

After applying the first coating liquid to the electrode substrate 100 for electrolysis, it is dried at a temperature of 10 to 90 ° C and subjected to pyrolysis in a roasting furnace heated to a temperature of 350 to 650 ° C. Between drying and pyrolysis, if necessary, a pre-firing can be performed at a temperature of 100 to 350 ° C. The temperature for drying, pre-firing and pyrolysis is appropriately selected depending on the composition and type of solvent of the first coating liquid. A longer period of pyrolysis time in each step is preferable, but from the viewpoint of productivity of producing an electrode, 3 to 60 minutes, more preferably 5 to 20 minutes are preferable.

[0769] The cycle of the above-described application, drying and pyrolysis is repeated to form a coating (first layer 20) to a predetermined thickness. After the first layer 20 is formed and then further post-baked for an extended period of time as required, this can further increase the stability of the first layer 20.

[0770] (Formation of the second layer)

The second layer 30, which is formed if necessary, is obtained, for example, by applying a solution containing a palladium compound and a platinum compound or a solution containing a ruthenium compound and a titanium compound (second coating liquid) on the first layer 20, and then the coating liquid is subjected to pyrolysis in presence of oxygen.

[0771] (Formation of the first cathode layer by pyrolysis method)

(Application stage)

The first layer 20 is obtained by applying a solution in which metal salts in various combinations are dissolved (first coating liquid) on an electrode substrate for electrolysis, and then pyrolysis (calcining) the coating liquid in the presence of oxygen. The metal content in the first coating liquid is substantially equivalent to that in the first layer 20.

[0772] The metal salts can be chlorides, nitrates, sulfates, metal alkoxides, and any other form. The solvent of the first coating liquid can be selected depending on the type of metal salt, and water and alcohols such as butanol can be used. As the solvent, water or a mixed solvent of water and alcohol is preferred. The total metal concentration in the first coating liquid in which the metal salts are dissolved is not particularly limited, but is preferably in the range of 10 to 150 g / L in consideration of the thickness of the coating film formed by a single application.

[0773] Examples of the method used as the method for applying the first coating liquid to the electrolysis electrode substrate 10 include a method for dipping the electrolysis electrode substrate 10 into the first coating liquid, a method for applying the first coating liquid with a brush, a rolling method using a sponge roller impregnated the first coating liquid, and an electrostatic coating method in which the electrode substrate 10 for electrolysis and the first coating liquid are charged with opposite charges and sputtering is performed. Among them, a rolling method or an electrostatic coating method is preferable, which has excellent production performance on an industrial scale.

[0774] (Drying Step and Pyrolysis Step)

After applying the first coating liquid to the electrode substrate 100 for electrolysis, it is dried at a temperature of 10 to 90 ° C and subjected to pyrolysis in a roasting furnace heated to a temperature of 350 to 650 ° C. Between drying and pyrolysis, if necessary, a pre-firing can be performed at a temperature of 100 to 350 ° C. The temperature for drying, pre-firing and pyrolysis is appropriately selected depending on the composition and type of solvent of the first coating liquid. A longer period of pyrolysis time in each step is preferable, but from the viewpoint of productivity of producing an electrode, 3 to 60 minutes, more preferably 5 to 20 minutes are preferable.

[0775] The cycle of the above-described application, drying and pyrolysis is repeated to form a coating (first layer 20) to a predetermined thickness. After the first layer 20 is formed and then further post-baked for an extended period of time as required, this can further increase the stability of the first layer 20.

[0776] (Interlayer Formation)

The intermediate layer, which is formed, if necessary, is obtained, for example, by applying a solution containing a palladium compound or a platinum compound (second coating liquid) to a substrate, and then pyrolysis of the coating liquid in the presence of oxygen. Alternatively, the nickel oxide intermediate layer can be formed on the surface of the substrate by heating the substrate only, without applying a solution thereto.

[0777] (Formation of the first cathode layer by ion deposition)

The first layer 20 can also be formed by ion deposition.

The example comprises a method in which a substrate is fixed in a chamber and a ruthenium metal target is irradiated with an electron beam. Particles of vaporized metallic ruthenium are positively charged in the plasma in the chamber, deposited on a negatively charged substrate. The plasma atmosphere is argon and / or oxygen and ruthenium is deposited on the substrate as ruthenium oxide.

[0778] (Formation of the first cathode layer by electrodeposition)

The first layer 20 can also be formed by electrodeposition.

As an example, when the substrate is used as a cathode and is subjected to plating in an electrolyte solution containing nickel and tin, an electrolytic plating of a nickel-tin alloy can be formed.

[0779] (Formation of the first layer of the cathode by thermal spraying)

The first layer 20 can also be formed by thermal spraying.

By way of example, nickel oxide particles sprayed by plasma onto a substrate may form a catalyst bed in which nickel metal and nickel oxide are mixed.

[0780] [Laminated Product]

The electrolysis electrode in the present embodiment may be combined with a membrane such as an ion exchange membrane or a microporous membrane and used as a laminated article. That is, the laminated article in the present embodiment contains an electrode for electrolysis and a new membrane. The new membrane is not particularly limited as long as it is separate from the membrane in the existing cell, and a variety of known "membranes" can be used. The material, shape, physical properties, and the like of the new membrane may be similar to those of the existing electrolyzer.

[0781] Next, an ion exchange membrane according to one aspect of the membrane will be described in detail.

[Ion exchange membrane]

The ion exchange membrane is not particularly limited as long as the membrane can be laminated with an electrolysis electrode and a variety of ion exchange membranes can be used. In the present embodiment, an ion exchange membrane is preferably used which has a membrane body containing a hydrocarbon polymer or a fluorine-containing polymer having an ion exchange group and a coating layer provided on at least one surface of the membrane body. It is preferable that the coating layer contains particles of inorganic material and a binder, and the specific surface area of the coating layer is 0.1 to 10 m ² / g. In an ion exchange membrane having such a structure, the effect of gas evolved during electrolysis on the electrolysis performance is small, and stable electrolysis performance can be demonstrated.

The above-described fluoropolymer ion exchange membrane into which an ion exchange group has been introduced contains one of either a sulfonic acid layer having an ion exchange group derived from a sulfo group (a group represented by —SO ₃ ^- , hereinafter also referred to as a “sulfonic acid group”), or a carboxylic acid layer having an ion exchange group derived from a carboxyl group (a group represented as —CO ₂ ^- , hereinafter also referred to as a “carboxylic acid group”). From the point of view of strength and dimensional stability, it is preferable to additionally include core reinforcing materials.

The inorganic material particles and the binder will be described in detail below in the coating layer description section.

[0782] Figure 97 illustrates a schematic sectional view showing one embodiment of an ion exchange membrane. The ion exchange membrane 1 has a membrane body 10 containing a hydrocarbon polymer or a fluorine-containing polymer having an ion exchange group, and coating layers 11a and 11b formed on both surfaces of the membrane body 10.

[0783] In the ion exchange membrane 1, the membrane body 10 includes a sulfonic acid layer 3 having an ion exchange group derived from a sulfo group (a group represented by —SO ₃ ^- , hereinafter also referred to as a “sulfonic acid group”), and a carboxylic acid layer 2, having an ion exchange group derived from a carboxyl group (a group represented by —CO ₂ ^- , hereinafter also referred to as a “carboxylic acid group”), and core reinforcing materials 4 that increase strength and dimensional stability. An ion exchange membrane 1 including a sulfonic acid layer 3 and a carboxylic acid layer 2 is suitably used as an anion exchange membrane.

[0784] The ion exchange membrane may include one of a sulfonic acid layer and a carboxylic acid layer. The ion exchange membrane does not need to be reinforced with core reinforcing materials, and the arrangement of the core reinforcing materials is not limited to the example in FIG. 97.

[0785] (Membrane Body)

First, the membrane body 10 constituting the ion exchange membrane 1 will be described.

The body 10 of the membrane should be such that its function is to provide selective permeation of cations, and contains a hydrocarbon polymer or a fluorine-containing polymer having an ion exchange group. Its configuration and material are not particularly limited, and preferable ones can be appropriately selected.

[0786] The hydrocarbon polymer or fluorine-containing polymer having an ion exchange group in the membrane body 10 can be obtained from a hydrocarbon polymer or fluorine-containing polymer having an ion exchange group precursor capable of forming an ion exchange group by hydrolysis or the like. More specifically, for example, after a polymer containing a fluorinated hydrocarbon backbone having a side chain that is converted to an ion exchange group by hydrolysis or the like (ion exchange group precursor) is used to obtain a precursor of the membrane body 10, and melt-processable ( below in some cases referred to as "fluoropolymer (s)" ""), the membrane body 10 can be obtained by converting a precursor of an ion exchange group into an ion exchange group.

[0787] The fluorine-containing polymer (s) can be obtained, for example, by copolymerizing at least one monomer selected from the next first group and at least one monomer selected from the next second group and / or the next third group. The fluorine-containing polymer (s) can also be obtained by homopolymerizing one monomer selected from any of the next first group, the next second group, and the next third group.

[0788] Examples of monomers of the first group include vinyl fluoride compounds. Examples of vinyl fluoride compounds include vinyl fluoride, tetrafluoroethylene, hexafluoropropylene, vinylidene fluoride, trifluoroethylene, chlorotrifluoroethylene, and perfluoroalkyl vinyl ethers. In particular, when an ion exchange membrane is used as a membrane for alkaline electrolysis, the vinyl fluoride compound is preferably a perfluorinated monomer, and a perfluorinated monomer selected from the group consisting of tetrafluoroethylene, hexafluoropropylene and perfluoroalkyl vinyl ethers is preferred.

[0789] Examples of monomers of the second group include vinyl compounds having a functional group convertible to an ion exchange group of the carboxylic acid type (carboxylic acid group). Examples of vinyl compounds having a functional group convertible to a carboxylic acid ion exchange group include monomers represented by the formula CF ₂ = CF (OCF ₂ CYF) _s –O (CZF) _t –COOR, in which s is an integer from 0 to 2, t is an integer from 1 to 12, each of Y and Z is independently F or CF ₃ and R is a lower alkyl group (a lower alkyl group is an alkyl group having, for example, 1 to 3 carbon atoms).

[0790] Among them, preferred are compounds represented by the formula CF ₂ = CF (OCF ₂ CYF) _n —O (CF ₂ ) _m —COOR, in which n represents an integer from 0 to 2, m represents an integer from 1 to 4, Y is F or CF ₃ and R is CH ₃ , C ₂ H ₅ or C ₃ H ₇ .

[0791] When the ion exchange membrane is used as a cation exchange membrane for alkaline electrolysis, the perfluoro compound is preferably used at least as a monomer, but the alkyl group (see R values above) of the ester group is lost from the polymer during hydrolysis, and therefore the alkyl group (R) is not must necessarily be a perfluoroalkyl group in which all hydrogen atoms are replaced by fluorine atoms.

[0792] Of the above monomers, the following monomers are more preferred as monomers of the second group:

CF ₂ = CFOCF ₂ –CF (CF ₃ ) OCF ₂ COOCH ₃ ,

CF ₂ = CFOCF ₂ CF (CF ₃ ) O (CF ₂ ) ₂ COOCH ₃ ,

CF ₂ = CF [OCF ₂ –CF (CF ₃ )] ₂ O (CF ₂ ) ₂ COOCH ₃ ,

CF ₂ = CFOCF ₂ CF (CF ₃ ) O (CF ₂ ) ₃ COOCH ₃ ,

CF ₂ = CFO (CF ₂ ) ₂ COOCH ₃ and

CF ₂ = CFO (CF ₂ ) ₃ COOCH ₃ .

[0793] Examples of monomers of the third group include vinyl compounds having a functional group convertible to an ion exchange group of the sulfone type (sulfonic acid group). As vinyl compounds having a functional group convertible to a sulfonic acid ion exchange group, for example, monomers represented by the formula CF ₂ = CFO — X — CF ₂ —SO ₂ F in which X is a perfluoroalkylene group are preferred. Specific examples include the following monomers:

CF ₂ = CFOCF ₂ CF ₂ SO ₂ F,

CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₂ F,

CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ CF ₂ SO ₂ F,

CF ₂ = CF (CF ₂ ) ₂ SO ₂ F,

CF ₂ = CFO [CF ₂ CF (CF ₃ ) O] ₂ CF ₂ CF ₂ SO ₂ F and

CF ₂ = CFOCF ₂ CF (CF ₂ OCF ₃ ) OCF ₂ CF ₂ SO ₂ F.

[0794] Among them, CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ CF ₂ SO ₂ F and CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₂ F.

[0795] The copolymer obtained from these monomers can be formed by a polymerization method designed for homopolymerization and copolymerization of ethylene fluoride, in particular, by a general polymerization method used for tetrafluoroethylene. For example, in a method using a non-aqueous medium, the polymerization reaction can be carried out in the presence of a free radical polymerization initiator such as a perfluorocarbon peroxide or an azo compound, under conditions of a temperature of 0 to 200 ° C and a pressure of 0.1 to 20 MPa, using an inert solvent, such as a perfluorocarbon or a chlorofluorocarbon.

[0796] In the above copolymerization, the type of combination of the above monomers and their proportions are not particularly limited and are determined depending on the type and amount of functional groups that it is desirable to introduce into the resulting fluorine-containing polymer. For example, when a fluorine-containing polymer containing only a carboxylic acid group is produced, at least one polymer must be selected from each of the above-described first group and second group and copolymerized. In addition, when a fluorine-containing polymer containing only a sulfonic acid group is prepared, at least one polymer must be selected from each of the first group and the third group, and copolymerized. In addition, when a fluorine-containing polymer having a carboxylic acid group and a sulfonic acid group is produced, at least one monomer must be selected from each of the above-described first group, second group and third group and copolymerized. In this case, the target fluorine-containing polymer can also be obtained by separately forming a copolymer including monomers of the above-described first group and second group, and a copolymer including monomers of the above-described first group and third group, and then mixing these copolymers. The composition of the mixture of monomers is not particularly limited, and when the number of functional groups per structural unit of the polymer increases, the proportion of monomers selected from the above-described second group and third group must increase.

[0797] The total ion exchange capacity of the fluorine-containing copolymer is not particularly limited, but is preferably 0.5 to 2.0 mg⋅eq / g, more preferably 0.6 to 1.5 mg⋅eq / g. The total ion exchange capacity here refers to the equivalent of the exchange group per unit weight of dry resin and can be measured by neutralization titration or the like.

[0798] In the membrane body 10 of the ion exchange membrane 1, a sulfonic acid layer 3 containing a fluorine-containing polymer having a sulfonic acid group and a carboxylic acid layer 2 containing a fluorine-containing polymer having a carboxylic acid group are laminated. By providing the membrane body 10 having such a layer configuration, the selective permeability to cations such as sodium ions can be further improved.

[0799] The ion exchange membrane 1 is disposed in the electrolytic cell so that generally the sulfonic acid layer 3 is on the anode side of the cell and the carboxylic acid layer 2 is on the cathode side of the cell.

[0800] The sulfonic acid layer 3 is preferably composed of a material having a low electrical resistance and is thicker than the carboxylic acid layer 2 in terms of membrane strength. The thickness of the sulfonic acid layer 3 is preferably 2 to 25 times, more preferably 3 to 15 times the thickness of the carboxylic acid layer 2.

[0801] The carboxylic acid layer 2 preferably has high anion exclusion characteristics even if it is thin. The anion exclusion characteristics herein refer to the characteristic of hindering the incorporation and penetration of anions into or through the ion exchange membrane 1. In order to improve the anion exclusion characteristics, it is effective to place a carboxylic acid layer having a low ion exchange capacity compared to the sulfonic acid layer.

[0802] As the fluorine-containing polymer for use in the sulfonic acid layer 3, a polymer obtained using CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₂ F as the third group monomer is preferable.

[0803] As the fluorine-containing polymer for use in the carboxylic acid layer 2, a polymer obtained using CF ₂ = CFOCF ₂ CF (CF ₂ ) O (CF ₂ ) ₂ COOCH _{3 is} preferred as the monomer of the second group.

[0804] (Coating layer)

The ion exchange membrane preferably has a coating layer on at least one surface of the membrane body. As shown in Figure 97, in the ion exchange membrane 1, coating layers 11a and 11b are formed on both surfaces of the membrane body 10.

The coating layers contain particles of inorganic material and a binder.

[0805] The average particle size of the particles of the inorganic material is preferably 0.90 µm or more. When the average particle size of the inorganic material is 0.90 µm or more, impurity resistance is greatly improved in addition to gas attachment. That is, by increasing the average particle size of the inorganic material as well as keeping the above-mentioned specific surface area, a particularly noticeable effect can be achieved. Uneven particles of inorganic material are preferred insofar as the above average particle size and specific surface area are satisfied. Melting inorganic material particles and raw ore milling inorganic material particles can be used. Preferably, particles of inorganic material obtained by milling raw ore are used.

[0806] The average particle size of the inorganic material may be 2 µm or less. When the average particle size of the inorganic material is 2 µm or less, damage to the membrane by the inorganic material can be prevented. The average particle size of the inorganic material is more preferably 0.90 to 1.2 µm.

[0807] Here, the average particle size can be measured by a particle size analyzer ("SALD2200", manufactured by SHIMADZU CORPORATION).

[0808] The particles of inorganic material are preferably irregular in shape. Such shapes further improve the resistance to impurities. The particles of inorganic material preferably have a wide particle size distribution.

[0809] The particles of inorganic material preferably contain at least one inorganic material selected from the group consisting of oxides of Group IV elements of the Periodic Table, nitrides of Group IV elements of the Periodic Table, and carbides of Group IV elements of the Periodic Table. From the standpoint of resistance, zirconium oxide particles are more preferable.

[0810] The particles of inorganic material are preferably particles of inorganic material obtained by grinding raw ore from particles of inorganic material, or particles of inorganic material in the form of spherical particles having a uniform diameter, obtained by refining a melt of raw ore from particles of inorganic material.

[0811] Examples of means for grinding raw ore include, but are not specifically limited to, ball mills, bead mills, colloid mills, cone grinders, disc mills, runners, grain mills, hammer mills, granulators, vertical shaft impact crushers (VSI ), leather mills (Wiley mills), roller mills and jet mills. After grinding, the particles are preferably washed. As a washing method, the particles are preferably treated with an acid. This treatment can reduce the amount of impurities such as iron adhered to the surface of the inorganic material particles.

[0812] The coating layer preferably contains a binder. The binder is the component that forms the coating layers by retaining particles of inorganic material on the surface of the ion exchange membrane. The binder preferably contains a fluorine-containing polymer from the standpoint of resistance to electrolyte solution and electrolysis products.

[0813] As the binder, a fluorine-containing polymer having a carboxylic acid group or a sulfonic acid group is more preferable in terms of resistance to electrolyte solution and electrolysis products and adhesion strength to the surface of the ion exchange membrane. When the coating layer is provided on a layer containing a fluorine-containing polymer having a sulfonic acid group (sulfonic acid layer), the fluorine-containing polymer having a sulfonic acid group is even more preferably used as a binder for the coating layer. Alternatively, when the coating layer is provided on a layer containing a fluorine-containing polymer having a carboxylic acid group (carboxylic acid layer), a fluorine-containing polymer having a carboxylic acid group is more preferably used as a binder for the coating layer.

[0814] The content of the particles of inorganic material in the coating layer is preferably 40 to 90% by mass, more preferably 50 to 90% by mass. The content of the binder is preferably 10 to 60% by mass, more preferably 10 to 50% by mass.

[0815] The distribution density of the coating layer in the ion exchange membrane is preferably 0.05 to 2 mg per cm ² . When the ion exchange membrane has ridges (roughness) on its surface, the distribution density of the coating layer is preferably 0.5 to 2 mg per cm ² .

[0816] As a method for manufacturing the coating layer, which is not particularly limited, a known method can be applied. An example is a method comprising applying by spray or the like a coating liquid obtained by dispersing particles of an inorganic material in a solution containing a binder.

[0817] (Core Reinforcement Materials)

The ion exchange membrane preferably has core reinforcing materials disposed within the membrane body.

[0818] Reinforcing materials of the core are elements that increase the strength and dimensional stability of the ion exchange membrane. By placing the reinforcing materials of the core within the body of the membrane, it is possible, in particular, to control the expansion and contraction of the ion exchange membrane in the desired range. Such an ion exchange membrane does not expand or contract more than necessary during electrolysis and the like, and can maintain excellent dimensional stability for a long time.

[0819] The configuration of the core reinforcing materials is not particularly limited, and, for example, the core reinforcing materials may be formed by woven yarns called reinforcing yarns. Reinforcing yarns herein refer to yarns that constitute the constituent core reinforcing materials, can provide the desired dimensional stability and mechanical strength to the ion exchange membrane, and can be stably present in the ion exchange membrane. By using core reinforcing materials obtained by weaving such reinforcing yarns, better dimensional stability and mechanical strength can be imparted to the ion exchange membrane.

[0820] The material of the reinforcing materials of the core and the reinforcing yarns used therefor is not particularly limited, but is preferably a material resistant to acids, alkalis, etc., and a fiber including a fluorine-containing polymer is preferable since long-term heat resistance and chemical resistance are required. ...

[0821] Examples of the fluoropolymer used in core reinforcing materials include polytetrafluoroethylene (PTFE), copolymers of tetrafluoroethylene and perfluoroalkyl vinyl ether (PFA), copolymers of tetrafluoroethylene and ethylene (ETFE), copolymers of tetrafluoroethylene copolymers and copolymers of tetrafluoroethylene copolymers and copolymers of tetrafluoroethylene copolymers PVDF). Among them, fibers including polytetrafluoroethylene are preferably used in terms of heat resistance and chemical resistance.

[0822] The diameter of the reinforcing yarns used for the core reinforcing materials is not particularly limited, but is preferably 20 to 300 denier, more preferably 50 to 250 denier. The weave density (web density per unit length) is preferably 5 to 50 / inch. The shape of the core reinforcing materials is not particularly limited, for example, woven fabric, non-woven fabric and knitted fabric are used, but preferably in the form of woven fabric. The thickness of the woven fabric used is preferably 30 to 250 µm, more preferably 30 to 150 µm.

[0823] As the woven fabric or knitted fabric, monofilaments, multifilaments or yarns thereof, twisted yarns with dangling yarns or the like can be used, and various types of weaving methods can be used such as plain weave, leno weave, knitted weave, cord weave and crinkled chintz (seersucker).

[0824] The braiding and placement of the core reinforcing materials in the membrane body are not particularly limited, and the preferred placement can be appropriately provided in consideration of the size and shape of the ion exchange membrane, physical properties desired for the ion exchange membrane, environmental conditions in use, and the like.

[0825] For example, the core reinforcing materials may be placed along a predetermined direction of the membrane body, but from a dimensional stability point of view, it is preferable that the core reinforcing materials are placed along a predetermined first direction and other core reinforcing materials are placed along a predetermined second direction along essentially perpendicular to the first direction. By placing multiple core reinforcement materials substantially orthogonal within the membrane body, better dimensional stability and mechanical strength in many directions can be imparted. For example, a configuration is preferable in which core reinforcing materials disposed along the longitudinal direction (warp yarns) and core reinforcing materials disposed along the transverse direction (weft yarns) are woven on the surface side of the membrane body. A more preferred configuration is a plain weave, made and woven by allowing the warp yarn and the weft yarn to pass alternately above and below each other, a leno weave in which the two warp strands are woven into the twist weft strands, a matting weave, made and woven by inserting the same number of weft yarns into two or more parallel warp yarns, or the like, from the standpoint of dimensional stability, mechanical strength and ease of manufacture.

[0826] It is particularly preferred that the core reinforcing materials are disposed along both directions MD (longitudinal direction) and TD (transverse direction) of the ion exchange membrane. In other words, the core reinforcing materials are preferably plain weave in MD and TD. Here, MD means the direction in which the membrane body and various core materials (for example, reinforcing core materials, reinforcing yarns and consumable yarns described later) move in the later described stage of obtaining the ion exchange membrane (flow direction), and TD means a direction substantially perpendicular to MD ... The yarns weaved along the MD are called MD yarns, and the yarns weaved along the TD are called TD yarns. Typically, the ion exchange membrane used for electrolysis is rectangular, and in many cases, the longitudinal direction is MD and the width direction is TD. By weaving reinforcing core materials that are MD yarns and reinforcing core materials that are TD yarns, better dimensional stability and mechanical strength can be achieved in many directions.

[0827] The placement range of the core reinforcing materials is not particularly limited, and the preferred placement can be appropriately provided in consideration of the physical properties desired for the ion exchange membrane, the environmental conditions in use, and the like.

[0828] The opening ratio of the core reinforcing materials is not particularly limited, but is preferably 30% or more, more preferably 50% or more and 90% or less. The opening ratio is preferably 30% or more in terms of the electrochemical characteristics of the ion exchange membrane, and preferably 90% or less in terms of the mechanical strength of the ion exchange membrane.

[0829] The opening ratio of the reinforcing materials of the core herein refers to the ratio (B / A) of the total surface area (B) through which substances such as ions (electrolyte solution and cations (eg sodium ions) contained therein) can pass to area (A) of any one surface of the body of the ion-exchange membrane. The total surface area (B) through which substances such as ions can pass may refer to the total areas of regions in which cations, electrolyte solution and the like are not retained in the ion exchange membrane by the reinforcing materials of the core and the like contained in the ion exchange membrane. membrane.

[0830] Figure 98 illustrates a schematic view for a relative opening of the core reinforcement materials constituting the ion exchange membrane. Figure 98, in which a portion of the ion exchange membrane is shown enlarged, shows only the configuration of the reinforcing materials 21 and 22 of the core in these regions, without showing other elements.

[0831] By subtracting the total area (C) of the core reinforcing materials from the area of the area surrounded by the core reinforcing materials 21 located along the longitudinal direction and the core reinforcing materials 22 located along the transverse direction, the area including the area (A) of the core reinforcing materials can the total area (B) of the regions through which substances such as ions can pass in the area (A) of the above-described region can be obtained. That is, the relative aperture can be determined by the following formula (I):

Relative aperture = (B) / (A) = ((A) - (C)) / (A) (I)

[0832] Among the reinforcing materials of the core, a film textile thread or highly oriented monofilaments including PTFE is particularly preferred in terms of chemical resistance and heat resistance. More specifically, more preferred are plain weave core reinforcing materials that use 50 to 300 denier film textile yarns made by cutting a PTFE-containing high tenacity porous sheet into ribbon-shaped pieces, or comprising highly oriented PTFE monofilaments of 50 to 300 denier sizes. 300 denier, and which have a weave density of 10 to 50 threads or monofilaments per inch and have a thickness in the range of 50 to 100 microns. The opening ratio of the ion exchange membrane including such core reinforcing materials is more preferably 60% or more.

[0833] Examples of the shape of the reinforcing yarns include round yarns and film threads.

[0834] (Through Holes)

The ion exchange membrane preferably has through holes within the membrane body.

[0835] Through holes refer to holes that can form channels for ions generated during electrolysis and for an electrolyte solution. Through holes, which are tubular holes formed within the membrane body, are formed by dissolving the core consumables (or yarns) described below. The shape, diameter, or the like of the through holes can be controlled by selecting the shape or diameter of the core consumables (yarn consumables).

[0836] The formation of through holes within the ion exchange membrane can provide mobility of the electrolyte solution during electrolysis. The shape of the through holes is not particularly limited, but may be the shape of the core consumable materials used to form the through holes according to the production method described below.

[0837] The through holes are preferably formed to alternately pass on the anode side (sulfonic acid layer side) and cathode side (carboxylic acid layer side) of the core reinforcing materials. With this arrangement, in the region in which the through holes are formed on the cathode side of the core reinforcing materials, ions (eg sodium ions) supplied by the electrolyte solution filling the through holes can also flow to the cathode side of the core reinforcing materials. As a result, the flow of cations is not interrupted, and thus an additional reduction in the electrical resistance of the ion-exchange membrane is possible.

[0838] The through holes may be formed along only one predetermined direction of the membrane body constituting the ion exchange membrane, but are preferably formed along both the longitudinal direction and the transverse direction of the membrane body in view of exhibiting more stable electrolysis characteristics.

[0839] [Manufacturing Method]

A suitable example of a method for manufacturing an ion exchange membrane includes a method comprising the following steps (1) to (6):

Step (1): a step of producing a fluorine-containing polymer having an ion exchange group or an ion exchange group precursor capable of forming an ion exchange group by hydrolysis,

Step (2): a step of weaving at least a plurality of core reinforcing materials, if necessary, and consumable yarns that dissolve in acid or alkali and form through holes, to obtain a reinforcing material in which the consumable yarns are interposed between the core reinforcing materials, being adjacent to each other,

Step (3): a step of converting into a film the above fluorine-containing polymer having an ion exchange group or an ion exchange group precursor capable of forming an ion exchange group by hydrolysis,

Step (4): the step of introducing the above reinforcing materials, if necessary, into the above film to obtain a membrane body, inside which the reinforcing materials are placed,

Stage (5): stage of hydrolysis of the membrane body obtained in stage (4) (stage of hydrolysis) and

Step (6): The step of creating a coating layer on the membrane body obtained in step (5) (application step).

[0840] Next, each of the steps will be described in detail.

[0841] Step (1): the step of obtaining a fluoropolymer

In step (1), the monomeric starting materials described above in groups one to three are used to prepare the fluoropolymer. To regulate the ion-exchange capacity of the fluorine-containing polymer, the composition of the mixture of the starting monomer materials must be controlled during the production of the fluorine-containing polymer forming the said layers.

[0842] Stage (2): the stage of obtaining reinforcing materials

The reinforcing material is a woven fabric obtained by weaving reinforcing yarns or the like. The reinforcing material is embedded in the membrane to thereby form core reinforcing materials. When an ion-exchange membrane with through holes is formed, consumable yarns are additionally woven into the reinforcing material. The amount of consumable yarns contained in this case is preferably 10 to 80% by mass, more preferably 30 to 70% by mass, based on the total reinforcing material. The weaving of the consumable yarns can also prevent slippage of the yarns of the core reinforcing materials.

[0843] Viscose, polyethylene terephthalate (PET), cellulose, polyamide and the like are used as the consumable yarns that are dissolved in the membrane production step or in the electrolysis environment. Also preferred are monofilaments or multifilaments having a thickness of 20 to 50 denier and including polyvinyl alcohol and the like.

[0844] In step (2), the aperture ratio, the placement of the through holes and the like can be adjusted by adjusting the placement of the core reinforcing materials and the yarns consumed.

[0845] Step (3): Film forming step

In step (3), the fluoropolymer obtained in step (1) is formed into a film using an extruder. The film may have a single layer configuration, a two layer configuration of a sulfonic acid layer and a carboxylic acid layer as mentioned above, or a multilayer configuration of three or more layers.

[0846] Examples of the film forming method include the following:

a method in which a fluorine-containing polymer having a carboxylic acid group and a fluorine-containing polymer having a sulfonic acid group are separately formed into films; and

a method in which a fluorine-containing polymer having a carboxylic acid group and a fluorine-containing polymer having a sulfonic acid group are coextruded to form a composite film.

[0847] The number of each film can be more than one. Co-extrusion of different films is preferred because of their contribution to the increase in bond strength at the interface.

[0848] Step (4): The step of obtaining the membrane body

In step (4), the reinforcing material obtained in step (2) is embedded in the film obtained in step (3) to form a membrane body containing the reinforcing material.

[0849] Preferred examples of a method for forming a membrane body include (i) a method in which a fluorine-containing polymer having a precursor of a carboxylic acid group (e.g., a carboxylate functional group) (hereinafter referred to as a first layer) disposed on the cathode side and a fluorine-containing polymer having a precursor of a sulfonic acid group (for example, a sulfonyl fluoride functional group) (hereinafter, including this layer is called the second layer), is formed into a film by the method of coextrusion, and, if necessary, using a heat source and a vacuum source, a reinforcing material and a composite film from the second layer / the first layer is laminated in this order on a breathable heat-resistant release paper on a flat plate or drum having numerous pores on their surface, and combined at a temperature at which each polymer melts while at the same time evacuating air from under each of the layers by means of reduced pressure ; and (ii) a method in which, in addition to the composite film of the second layer / first layer, a fluorine-containing polymer having a precursor of a sulfonic acid group is separately preformed into a film (third layer), and optionally using a heat source and a source vacuum, the third layer film, the core reinforcing materials and the composite film from the second layer / first layer are laminated in this order on a breathable heat-resistant release paper on a flat plate or drum having multiple pores on their surface and combined at a temperature at which each polymer is melted while pumping air out from under each of the layers by means of reduced pressure.

[0850] Co-extrusion of the first and second layer here helps to increase the bond strength at the interface.

[0851] The method of combining under reduced pressure is characterized by making the third layer on the reinforcing material thicker than in the press-applied method. In addition, since the reinforcing material is fixed to the inner surface of the membrane body, the method provides sufficient retention of the mechanical strength of the ion exchange membrane.

[0852] Embodiments of the layering methods described herein are exemplary, and coextrusion may be performed after a preferred layering configuration (eg, a combination of layers) is appropriately selected in consideration of the desired membrane body layer configurations and physical properties, and the like.

[0853] In order to further improve the electrical characteristics of the ion exchange membrane, it is also possible to additionally place a fourth layer comprising a fluorine-containing polymer having both a precursor of a carboxylic acid group and a precursor of a sulfonic acid group between the first layer and the second layer, or the use of a fourth layer comprising a fluorine-containing polymer having both a precursor of a carboxylic acid group and a precursor of a sulfonic acid group instead of the second layer.

[0854] The method for forming the fourth layer may be a method in which a fluorine-containing polymer having a precursor of a carboxylic acid group and a fluorine-containing polymer having a precursor of a sulfonic acid group are separately prepared and then mixed, or it may be a method in which a monomer is copolymerized having a precursor of a carboxylic acid group; and a monomer having a sulfonic acid precursor.

[0855] When the fourth layer is used as a component of the ion exchange membrane, a coextruded film of the first layer and the fourth layer is formed, in addition, the third layer and the second layer are separately formed into films, and the layering can be performed in the above manner. Alternatively, three layers of the first layer / fourth layer / second layer can be coextruded simultaneously to form a film.

[0856] In this case, the direction in which the extruded film flows out is MD. As mentioned above, it is possible to form a membrane body containing a fluorine-containing polymer having an ion exchange group on the reinforcing material.

[0857] In addition, the ion exchange membrane preferably has protrusions constituted by a fluoropolymer having a sulfonic acid group, that is, protrusions on the side of the surface constituted by the sulfonic acid layer. As a method for forming such protrusions, which is not particularly limited, a known method including forming protrusions on a resin surface can also be applied. A specific example of the method is a method for embossing the surface of a membrane body. For example, the aforementioned protrusions can be formed using the pre-embossed release paper when the above composite film, reinforcing material, and the like are combined. In the case where the protrusions are formed by embossing, the height and density of the protrusions can be controlled by the shape of the transferred relief (the shape of the release paper).

[0858] (5) Hydrolysis Step

At step (5), the stage of hydrolysis of the membrane body obtained at stage (4) is performed to convert the precursor of the ion-exchange group into an ion-exchange group (stage of hydrolysis).

[0859] In step (5), it is also possible to dissolve holes in the membrane body by dissolving and removing consumable yarns introduced into the membrane body by the action of an acid or alkali. The consumable yarns can remain in the through holes without being completely dissolved and removed. The consumable yarns remaining in the through holes can be dissolved and removed by the electrolyte solution when the ion exchange membrane is subjected to electrolysis.

[0860] The consumable yarn is dissolved in acid or alkali during the ion exchange membrane preparation step or in the electrolysis environment. The consumable yarns are washed out, thereby forming the through-holes at the appropriate locations.

[0861] Step (5) may be performed by immersing the membrane body obtained in step (4) in a hydrolysis solution containing an acid or alkali. An example of a hydrolysis solution that can be used is a mixed solution containing KOH and dimethyl sulfoxide (DMSO).

[0862] The mixed solution preferably contains KOH at a normal concentration of 2.5 to 4.0 and DMSO from 25 to 35% by weight.

[0863] The temperature in the hydrolysis is preferably 70 to 100 ° C. The higher the temperature, the greater the apparent thickness can be. The temperature is more preferably 75 to 100 ° C.

[0864] The duration of the hydrolysis is preferably 10 to 120 minutes. The longer the hydrolysis takes, the greater the apparent thickness can be. The duration of the hydrolysis is preferably 20 to 120 minutes.

[0865] The step of forming the through holes by washing out the sacrificial yarns will now be described in more detail. Figures 99 (a) and (b) are schematic views for explaining a method of forming vias in an ion exchange membrane.

[0866] Figures 99 (a) and (b) show reinforcing yarns 52, sacrificial yarns 504a and through holes 504 formed only by sacrificial yarns 504a, without illustrating other features such as a membrane body.

[0867] First, the reinforcing yarns 52, which are to constitute the core reinforcing materials in the ion exchange membrane, and the consumable yarns 504a for forming the through holes 504 in the ion exchange membrane are used as interlaced reinforcing materials. Then, in step (5), the consumable yarns 504a are washed out to form the through holes 504.

[0868] The above method is simple because the method of interlacing reinforcing yarns 52 and consumable yarns 504a can be adjusted depending on the order of placement of the reinforcing materials of the core and through holes in the body of the ion exchange membrane.

[0869] Figure 99 (a) illustrates an example of a plain weave reinforcing material in which the reinforcing yarns 52 and the sacrificial yarns 504a are interlaced in both the longitudinal direction and the transverse direction in the paper, and optionally the order in which the reinforcing yarns 52 and the sacrificial yarn 504a in the reinforcing material can be changed.

[0870] (6) Application Phase

In step (6), a coating layer can be formed by preparing a coating liquid containing particles of inorganic material obtained by grinding raw ore or melting raw ore and a binder, applying a coating liquid to the surface of the ion exchange membrane obtained in step (5), and drying the coating liquids.

[0871] A preferred binder is a binder obtained by hydrolysis of a fluoropolymer having an ion exchange group precursor with an aqueous solution containing dimethyl sulfoxide (DMSO) and potassium hydroxide (KOH), and then immersing the polymer in hydrochloric acid to replace the counter ion of the ion exchange group with H ⁺ ( for example, a fluorine-containing polymer having a carboxyl group or a sulfo group). Thus, the polymer is more likely to dissolve in water or ethanol, as mentioned below, which is preferred.

[0872] This binder is dissolved in a mixed solution of water and ethanol. The volume ratio between water and ethanol is preferably 10: 1 to 1:10, more preferably 5: 1 to 1: 5, even more preferably 2: 1 to 1: 2. The particles of inorganic material are dispersed in the dissolving liquid by means of a ball mill, thereby forming a coating liquid. In this case, it is also possible to correct the average particle size and the like of particles by adjusting the duration and speed of rotation during dispersion. The preferred amount of the mixed particles of inorganic material and binder is as mentioned above.

[0873] The concentration of the particles of inorganic material and binder in the coating liquid is not particularly limited, but a free-flowing coating liquid is preferable. This makes it possible to uniformly apply the ion exchange membrane to the surface.

[0874] In addition, a surfactant may be added to the dispersion when particles of inorganic material are dispersed. As the surfactant, nonionic surfactants are preferred and examples include HS-210, NS-210, P-210 and E-212 from NOF CORPORATION.

[0875] The obtained coating liquid is applied to the surface of the ion exchange membrane by a spray application or roller coating, thereby forming an ion exchange membrane.

[0876] [Microporous Membrane]

The microporous membrane of the present embodiment is not particularly limited as long as the membrane can be formed to form an electrode laminated article for electrolysis as mentioned above. A variety of microporous membranes can be used.

The porosity of the microporous membrane of the present embodiment is not particularly limited, but may be, for example, 20 to 90, and preferably 30 to 85. The above porosity can be calculated by the following formula:

Porosity = (1– (dry weight of the membrane) / (weight calculated from the volume, calculated from the values of the thickness, width and length of the membrane, and the density of the membrane material)) × 100

The average pore size in the microporous membrane of the present embodiment is not particularly limited and may be, for example, 0.01 µm to 10 µm, preferably 0.05 µm to 5 µm. With regard to the average pore size, for example, the membrane is cut vertically in the direction of thickness, and the cross section is examined by field emission scanning electron microscopy (FE-SEM). The average pore size can be obtained by measuring the diameter of about 100 pores and averaging the results.

The thickness of the microporous membrane of the present embodiment is not particularly limited and may be, for example, 10 µm to 1000 µm, preferably 50 µm to 600 µm. The above thickness can be measured using, for example, a micrometer (manufactured by Mitutoyo Corporation) or the like.

Specific examples of a microporous membrane as above include Zirfon Perl UTP 500 manufactured by Agfa (also referred to as a Zirfon membrane in this embodiment) and are described in International Publication No. WO 2013-183584 and International Publication No. WO 2016-203701.

[0877] In the present embodiment, the membrane preferably comprises a first ion exchange resin layer and a second ion exchange resin layer having an EW (ion exchange capacity) value different from the EW of the first ion exchange resin layer. In addition, the membrane preferably contains a first ion exchange resin layer and a second ion exchange resin layer having a different functional group than the functional group in the first ion exchange resin layer. The ion exchange capacity can be adjusted by the introduced functional group, and the functional groups that can be introduced are as mentioned above.

[0878] (Water electrolysis)

The electrolyzer in the present embodiment as an electrolysis cell in the case of water electrolysis has a configuration in which an ion exchange membrane in the electrolysis cell for use in the case of the above conventional salt electrolysis is replaced with a microporous membrane. The supplied raw material, which is water, is different from the material for the electrolytic cell in the case of the above-mentioned conventional salt electrolysis. As for other components, parts similar to those of the electrolysis cell in the case of conventional salt electrolysis can also be used in a water electrolysis cell. Since chlorine gas is generated in the anode chamber in conventional salt electrolysis, titanium is used as the anode chamber material, but in the case of water electrolysis, only oxygen gas is emitted in the anode chamber. Thus, a material identical to that of the cathode chamber can be used. Nickel is one example of this. A catalytic coating for generating oxygen is suitable for coating the anode. Examples of the catalytic coating include metals, oxides and hydroxides of platinum group metals and metals from the transition metal group. For example, elements such as platinum, iridium, palladium, ruthenium, nickel, cobalt, and iron can be used.

[0879] [Method of electrode renewal]

The method for manufacturing an electrolytic cell of the present embodiment can also be implemented as a method for renewing an electrode (anode and / or cathode). That is, the method for renewing an electrode of the present embodiment is a method for renewing an existing electrode using an electrolysis electrode using an electrolysis electrode in the form of a coil.

Specific examples of the step of applying a coil include, but are not specifically limited to, a method in which an electrolysis electrode in the form of a coil, after being unwound, is placed on the surface of an existing electrode. By this method, an electrolysis electrode can be placed on the surface of an existing anode or cathode and the characteristics of the anode and / or cathode can be restored.

As described above, in the present embodiment, the step of applying the coil preferably has a step (B ') of releasing the coil from the wound state, and after step (B') more preferably has a step (C ') of placing an electrolysis electrode on the surface of the existing electrode.

[0880] Further, in the method for renewing an electrode of the present embodiment, the step of applying a coil preferably comprises a step (A ') of holding the electrolysis electrode in a wound state, thereby obtaining a coil. In step (A '), the electrolysis electrode may be wound by itself to form a coil, or the electrolysis electrode may be wound around the sleeve to form a coil. As the sleeve that can be used here, which is not particularly limited, for example, a member having a substantially cylindrical shape and having a size corresponding to the electrode for electrolysis can be used.

[0881] [Method of obtaining winding]

In the method for manufacturing an electrolytic cell of the present embodiment and in the method for renewing an electrode of the present embodiment, step (A) or (A ') that can be performed may be performed in the same manner as the method for producing a coil. That is, a method for producing a winding of the present embodiment is a method for producing a winding used to upgrade an existing electrolyzer including an anode, a cathode that is opposite the anode, and a membrane that is disposed between the anode and the cathode, the method including the step of winding an electrode for electrolysis, or a laminated article from an electrolysis electrode and a new membrane, thereby obtaining a winding. In the step of obtaining a winding, the electrolysis electrode can be wound on its own, or the electrolysis electrode can be wound around the sleeve to form a winding. As the core that can be used here, which is not particularly limited, for example, a member having a substantially cylindrical shape and having a size corresponding to an electrode for electrolysis can be used.

[0882] <Sixth embodiment>

Here, a sixth embodiment of the present invention will be described in detail with reference to Figures 103-111.

[0883] [Method of manufacturing an electrolytic cell]

A method for manufacturing an electrolytic cell according to a sixth embodiment (hereinafter in the section <Sixth Embodiment> simply referred to as "the present embodiment") is a method for forming a new electrolytic cell by placing a laminated article in an existing electrolytic cell including an anode, a cathode that is opposite the anode, and a membrane , which is disposed between the anode and the cathode, the method comprising the step (A) of combining the electrolysis electrode with a new membrane at a temperature at which the membrane does not melt, thereby obtaining a layered article, and the step (B) of replacing the membrane in an existing electrolyzer with a layered article after step (A).

As described above, according to the method for manufacturing the electrolytic cell of the present embodiment, it is possible to combine and use the electrolysis electrode and the membrane, but not according to an impractical method such as thermocompression. Thus, it is possible to improve the working efficiency during the renewal of the electrode in the electrolytic cell.

[0884] In the present embodiment, an existing electrolyzer contains an anode, a cathode that is opposite the anode, and a membrane that is interposed between the anode and the cathode as structural members, in other words, contains an electrolytic cell. The existing electrolytic cell is not particularly limited as long as it contains the above-described structural elements, and various known configurations can be applied.

[0885] In the present embodiment, the new electrolysis cell further comprises an electrolysis electrode or laminated article, in addition to an element that has already served as an anode or cathode in the existing electrolysis cell. That is, the "electrolysis electrode" positioned in the formation of a new cell serves as an anode or cathode and is separate from the cathode and anode in the existing cell. In the present embodiment, even in the case where the efficiency of the anode and / or cathode in electrolysis has deteriorated due to the operation of the existing electrolysis cell, placing the electrolysis electrode separately from them allows the performance of the anode and / or cathode to be restored. In addition, a new ion exchange membrane is placed in the combination with the laminated article, and thus the characteristics of the ion exchange membrane, the properties of which have deteriorated due to operation, can be simultaneously updated. As referred to herein, "performance upgrade" means achieving performance that is comparable to the original performance that the existing cell had before operation, or performance that exceeds the original performance.

[0886] In the present embodiment, the existing electrolyzer is considered to be "an electrolyzer that was already in operation", and a new electrolyzer is considered to be an "electrolyzer that has not yet been operated". That is, once the cell formed as a new cell starts to be used, the cell becomes the “existing cell in the present embodiment”. Placing an electrolysis electrode or laminated article in this existing electrolysis cell creates a “new electrolysis cell of the present embodiment”.

[0887] Next, a case of performing conventional salt electrolysis using an ion exchange membrane as an exemplary membrane and one embodiment of an electrolyser will be described in detail. In the section <Sixth Embodiment>, unless otherwise stated, “electrolyzer in the present embodiment” provides for both “an existing electrolyser in the present embodiment” and “a new electrolyser of the present embodiment”.

[0888] [Electrolytic Cell]

First, an electrolytic cell that can be used as a structural member of an electrolytic cell in the present embodiment will be described. Figure 103 illustrates a sectional view of an electrolytic cell 1.

The electrolytic cell 1 contains an anode chamber 10, a cathode chamber 20, a dividing wall 30 located between the anode chamber 10 and the cathode chamber 20, an anode 11 located in the anode chamber 10, and a cathode 21 located in the cathode chamber 20. If necessary, an electrolytic cell 1 has a substrate 18a and a reverse current absorbing layer 18b formed on the substrate 18a, and may include a reverse current absorber 18 disposed in the cathode chamber. The anode 11 and the cathode 21, which are part of the electrolytic cell 1, are electrically connected to each other. In other words, the electrolytic cell 1 contains the following cathode structure. The cathode structure 40 comprises a cathode chamber 20, a cathode 21 disposed in the cathode chamber 20, and a reverse current absorber 18 disposed in the cathode chamber 20, the reverse current absorber 18 having a substrate 18a and a reverse current absorbing layer 18b formed on the substrate 18a as shown in Figure 107, and the cathode 21 and the reverse current absorbing layer 18b are electrically connected. In addition, the cathode chamber 20 has a current collector 23, a holder 24 supporting the current collector, and a metal elastic body 22. The metal elastic body 22 is placed between the current collector 23 and the cathode 21. The holder 24 is located between the current collector 23 and the partition 30. The current collector 23 is electrically connected to cathode 21 through the metal elastic body 22. The separating partition 30 is electrically connected to the current collector 23 through the holder 24. Accordingly, the separating partition 30, the holder 24, the current collector 23, the metal elastic body 22 and the cathode 21 are electrically connected to each other. The cathode 21 and the reverse current absorbing layer 18b are electrically connected. The cathode 21 and the reverse current absorbing layer 18b may be connected directly, or may be connected indirectly through a down conductor, a holder, a metal resilient body, a baffle, or the like. The entire surface of the cathode 21 is preferably coated with a catalyst layer for the reduction reaction. The form of the electrical connection may be a form in which the baffle 30 and the support 24, the support 24 and the collector 23 and the collector 23 and the metal resilient body 22 are in each case directly connected to each other, and the cathode 21 is laminated on the metal resilient body 22. Examples methods for directly attaching these structural elements to each other include welding and the like. Alternatively, the reverse current absorber 18, the cathode 21, and the current collector 23 may be collectively referred to as the cathode structure 40.

[0889] Figure 104 illustrates a cross-sectional view of two electrolytic cells 1 that are adjacent in electrolytic cell 4. Figure 105 shows electrolytic cell 4. Figure 106 shows a step of assembling cell 4.

[0890] As shown in Figure 104, the electrolytic cell 1, the cation exchange membrane 2, and the electrolytic cell 1 are arranged in series in this order. Ion exchange membrane 2 is located between the anode chamber of one electrolytic cell 1 of two electrolytic cells that are adjacent in the electrolyzer and the cathode chamber of another electrolytic cell 1. That is, the anode chamber 10 of the electrolytic cell 1 and the cathode chamber 20 of the adjacent electrolytic cell 1 are separated by a cation exchange membrane 2. As shown in Figure 105, electrolyzer 4 consists of a plurality of electrolytic cells 1 connected in series through an ion exchange membrane 2. That is, electrolyzer 4 is a bipolar electrolyzer including a plurality of electrolytic cells 1 in series and ion exchange membranes 2, in each case arranged between adjacent electrolytic cells 1. As shown in Figure 106, cell 4 is assembled by placing a plurality of electrolytic cells 1 in series through the ion exchange membrane 2 and bonding the cells by means of a clamping device 5.

[0891] Electrolyzer 4 has an anode lead 7 and a cathode lead 6, which are connected to a power supply. An anode 11 of an electrolytic cell 1 located at the farthest end of a plurality of electrolytic cells 1 connected in series in an electrolysis cell 4 is electrically connected to an anode terminal 7. A cathode 21 of an electrolytic cell located at an end opposite to the anode terminal 7 among the plurality of electrolytic cells 1, connected in series in the electrolytic cell 4, electrically connected to the cathode terminal 6. Electric current during electrolysis flows from the side of the anode terminal 7 through the anode and the cathode of each electrolytic cell 1 towards the cathode terminal 6. At both ends of the connected electrolytic cells 1 there may be an electrolytic cell, having only an anode chamber (anode outlet cell), and an electrolytic cell having only a cathode chamber (cathode outlet cell). In this case, the anode terminal 7 is connected to an anode terminal cell located at one end, and the cathode terminal 6 is connected to a cathode terminal cell located at the other end.

[0892] In the case of brine electrolysis, brine is supplied to each anode chamber 10, and pure water or low concentration aqueous sodium hydroxide solution is supplied to each cathode chamber 20. Each liquid is supplied from an electrolyte solution supply pipe (not shown) through a hose for supplying an electrolyte solution (not shown in the figure) to each electrolytic cell 1. The electrolyte solution and electrolysis products are removed from the pipe for removing the electrolyte solution (not shown in the figure). During electrolysis, sodium ions in the brine migrate from the anode chamber 10 of one electrolytic cell 1 through the ion exchange membrane 2 to the cathode chamber 20 of the adjacent electrolytic cell 1. Thus, the electric current during electrolysis flows in the direction in which the electrolytic cells 1 are connected in series. That is, an electric current flows through the cation exchange membrane 2 from the anode chamber 10 towards the cathode chamber 20. When the brine is electrolyzed, chlorine gas is generated on the anode 11 side, and sodium hydroxide (dissolved) and hydrogen gas are generated on the cathode 21 side.

[0893] (Anode chamber)

The anode chamber 10 has an anode 11 or an anode supply conductor 11. Here, under the supply conductor is meant a worn electrode (ie, an existing electrode), an electrode not having a catalytic coating, and the like. When the electrolysis electrode in the present embodiment is inserted on the anode side, 11 serves as an anode supply conductor. When the electrolysis electrode of the present embodiment is not inserted on the anode side, 11 serves as an anode. The anode chamber 10 preferably has an anode-side electrolyte solution supply unit that supplies electrolyte solution to the anode chamber 10, a baffle plate that is positioned above the anode-side electrolyte solution supply unit so as to be substantially parallel or inclined with respect to the baffle 30, and a gas an anode-side liquid separator located above the baffle plate for separating gas from an electrolyte solution including an admixed gas.

[0894] (Anode)

When the electrode for electrolysis of the present embodiment is not inserted on the anode side, the anode 11 is in the frame of the anode chamber 10 (i.e., in the anode frame). As the anode 11, a metal electrode such as a so-called DSA (R) can be used. DSA is an electrode including a titanium substrate, the surface of which is coated with an oxide including ruthenium, iridium and titanium as components.

As for the shape, any of a perforated metal sheet, a nonwoven fabric, a porous metal, an expanded metal sheet, an electrospinning metal porous foil, a so-called woven metal mesh formed by interlacing of thin metal filaments, and the like can be used.

[0895] (Anode Supply Conductor)

When the electrode for electrolysis of the present embodiment is inserted on the anode side, an anode supply conductor 11 is provided on the frame of the anode chamber 10. A metal electrode such as a so-called DSA (R) can be used as the anode supply conductor 11, and can also be used titanium without catalytic coating. Alternatively, a DSA having a thinner catalytic coating can also be used. In addition, an already used anode can also be used.

As for the shape, any of a perforated metal sheet, a nonwoven fabric, a porous metal, an expanded metal sheet, an electrospinning metal porous foil, a so-called woven metal mesh formed by interlacing of thin metal filaments, and the like can be used.

[0896] (Anode side electrolyte solution supply unit)

An anode-side electrolyte solution supply unit that supplies an electrolyte solution to the anode chamber 10 is connected to a pipe for supplying an electrolyte solution. The anode side electrolyte solution supply unit is preferably disposed under the anode chamber 10. As the anode side electrolyte solution supply unit, for example, a pipe on the surface of which lumen portions (dispersion tube) and the like can be used. Such a tube is more preferably located along the surface of the anode 11 and parallel to the bottom 19 of the electrolytic cell. This pipe is connected to a pipe for supplying an electrolyte solution (a liquid supply pipe), which supplies an electrolyte solution to an electrolytic cell 1. The electrolyte solution supplied from a liquid supply pipe is passed through a pipe into an electrolytic cell 1 and is fed from holes made on the pipe surface inside the anode chambers 10. Placing the pipe along the surface of the anode 11 and parallel to the bottom 19 of the electrolytic cell is preferable because the electrolyte solution can be uniformly supplied to the inside of the anode chamber 10.

[0897] (Anode side gas-liquid separator)

The anode-side gas-liquid separator is preferably located above the baffle plate. The purpose of the anode-side gas-liquid separator is to separate the generated gas, such as chlorine gas, from the electrolyte solution during electrolysis. Unless otherwise specified, "above" means the upward direction in the electrolytic cell 1 in FIG. 103, and "under" means the downward direction in the electrolytic cell 1 in FIG. 103.

[0898] The gas generated during electrolysis evolved in the electrolytic cell 1 and the electrolyte solution form a mixed phase (gas-liquid mixed phase), which is then discharged from the system. As a consequence, pressure fluctuations within the electrolytic cell 1 cause vibration, which can lead to physical damage to the ion exchange membrane. To prevent this phenomenon, the electrolytic cell 1 of the present embodiment is preferably equipped with an anode-side gas-liquid separator for separating gas from liquid. The anode-side gas-liquid separator is preferably provided with a defoamer plate to eliminate bubbles. When the gas-liquid mixed phase stream flows through the defoamer plate, the bubbles burst, thereby separating the electrolyte solution and gas. As a result, vibration during electrolysis can be prevented.

[0899] (Baffle plate)

The baffle plate is preferably positioned above the anode side electrolyte solution supply unit and is positioned substantially parallel or obliquely with respect to the baffle 30. The baffle plate is a baffle plate that controls the flow of electrolyte solution into the anode chamber 10. When the baffle plate is provided, it can cause circulation electrolyte solution (brine or the like) inside the anode chamber 10, thereby making the concentration more uniform. To create internal circulation, the baffle plate is preferably positioned so as to separate the space near the anode 11 from the space near the baffle 30. For this reason, the baffle plate is preferably positioned so that it is opposite the surface of the anode 11 and the surface of the baffle 30. In the space near the anode separated by the baffle plate, electrolysis occurs, the concentration of the electrolyte solution (brine concentration) decreases, and a generated gas such as chlorine gas is released. This leads to a difference in the specific gravity of the gas-liquid mixture between the space near the anode 11 and the space near the dividing wall 30, separated by a baffle plate. Using this difference, it is possible to stimulate the internal circulation of the electrolyte solution in the anode chamber 10, thereby making the concentration distribution of the electrolyte solution in the anode chamber 10 more uniform.

[0900] Although not shown in Figure 103, a down conductor may also optionally be provided within the anode chamber 10. The material and configuration of such a current collector can be the same as for the aforementioned collector of the cathode chamber. In the anode chamber 10, the anode 11 itself can also serve as a down conductor.

[0901] (Divider)

The dividing wall 30 is disposed between the anode chamber 10 and the cathode chamber 20. The dividing wall 30 may be referred to as a separator, and the anode chamber 10 and the cathode chamber 20 are separated from each other by a dividing wall 30. As the dividing wall 30, a baffle known as a separator can be used. electrolysis, and an example thereof comprises a baffle formed by welding a nickel-containing plate on the cathode side and a titanium-containing plate on the anode side.

[0902] (Cathode Chamber)

In the cathode compartment 20, when the electrolysis electrode of the present embodiment is inserted on the cathode side, 21 serves as a cathode supply conductor. When the electrolysis electrode of the present embodiment is not inserted on the cathode side, 21 serves as the cathode. When a return current absorber is present, the cathode or cathode supply conductor 21 is electrically connected to the return current absorber. Cathode chamber 20, like anode chamber 10, preferably has a cathode-side electrolyte solution supply unit and a cathode-side gas-liquid separator. Among the components constituting the cathode compartment 20, components similar to those constituting the anode compartment 10 will not be described.

[0903] (Cathode)

When the electrode for electrolysis of the present embodiment is not inserted on the cathode side, the cathode 21 is in the frame of the cathode chamber 20 (i.e., in the cathode frame). Cathode 21 preferably has a nickel substrate and a catalyst layer that covers the nickel substrate. Examples of catalyst bed components include elements such as Ru, C, Si, P, S, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Rh, Pd , Ag, Cd, In, Sn, Ta, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho , Er, Tm, Yb and Lu, as well as oxides and hydroxides of these metals. Examples of the method for forming the catalyst layer include electrodeposition, alloy electrodeposition, dispersion / composite electrodeposition, CVD, FOPP, pyrolysis, and sputtering. These methods can be used in combination. The catalyst bed can have multiple layers and multiple elements as needed. The cathode 21 can be subjected to a reduction treatment, if necessary. Nickel, nickel alloys and nickel-plated iron or stainless steel can be used as the substrate for the cathode 21.

As for the shape, any of a perforated metal sheet, a nonwoven fabric, a porous metal, an expanded metal sheet, an electrospinning metal porous foil, a so-called woven metal mesh formed by interlacing of thin metal filaments, and the like can be used.

[0904] (Cathode Supply Conductor)

When the electrode for electrolysis of the present embodiment is inserted on the cathode side, a cathode supply conductor 21 is provided in the frame of the cathode chamber 20. The cathode supply conductor 21 may be coated with a catalyst component. The catalyst component can be a component that is initially used as a cathode and is stored. Examples of catalyst bed components include elements such as Ru, C, Si, P, S, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Rh, Pd , Ag, Cd, In, Sn, Ta, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho , Er, Tm, Yb and Lu, as well as oxides and hydroxides of these metals. Examples of the method for forming the catalyst layer include electrodeposition, alloy electrodeposition, dispersion / composite electrodeposition, CVD, FOPP, pyrolysis, and sputtering. These methods can be used in combination. The catalyst bed can have multiple layers and multiple elements as needed. Nickel, nickel alloys and nickel-plated iron or stainless steel without catalytic coating can be used. Nickel, nickel alloys and nickel-plated iron or stainless steel can be used as the substrate for the cathode supply conductor 21.

As for the shape, any of a perforated metal sheet, a nonwoven fabric, a porous metal, an expanded metal sheet, an electrospinning metal porous foil, a so-called woven metal mesh formed by interlacing of thin metal filaments, and the like can be used.

[0905] (Reverse current absorbing layer)

As the material for the layer that absorbs the reverse current, a material that is less noble in terms of the redox potential than the redox potential of the element for the aforementioned catalyst layer of the cathode can be selected. Examples include nickel and iron.

[0906] (Down conductor)

The cathode chamber 20 preferably contains a current collector 23. The current collector 23 improves the efficiency of current extraction. In the present embodiment, the collector 23 is a porous plate and is preferably disposed substantially parallel to the surface of the cathode 21.

[0907] The collector 23 preferably contains an electrically conductive metal such as nickel, iron, copper, silver and titanium. The current collector 23 can be a mixture, alloy or complex oxide of these metals. The collector 23 may be of any shape as long as the shape allows the collector to function and may be in the form of a plate or mesh.

[0908] (Metallic elastic body)

By placing the metal elastic body 22 between the current collector 23 and the cathode 21, each cathode 21 of a plurality of electrolytic cells 1 connected in series is pressed against the ion exchange membrane 2 to shorten the distance between each anode 11 and each cathode 21. Thus, it is possible to reduce the voltage applied to the entire plurality of electrolytic cells connected in series. cells 1. Reducing voltage helps to reduce power consumption. When the metal resilient body 22 is placed, the pressing pressure generated by the metal resilient body 22 allows the electrolysis electrode to stably maintain its position in place when the laminated article containing the electrolysis electrode in the present embodiment is placed in the electrolytic cell.

[0909] As the metal resilient body 22, spring members such as coil and coil springs and damping mats can be used. As the metal elastic body 22, an element can be appropriately applied in consideration of mechanical stress due to pressure on the ion exchange membrane and the like. The metal resilient body 22 may be located on the surface of the collector 23 on the side of the cathode chamber 20, or may be provided on the surface of the partition wall on the side of the anode chamber 10. The two chambers are usually separated so that the cathode chamber 20 becomes smaller than the anode chamber 10. Thus In terms of frame strength and the like, the metal resilient body 22 is preferably placed between the collector 34 and the cathode 21 in the cathode chamber 20. The metal resilient body 22 preferably contains an electrically conductive metal such as nickel, iron, copper, silver and titanium.

[0910] (Holder)

The cathode chamber 20 preferably comprises a holder 24 which electrically connects the collector 23 to the baffle 30. This can achieve an efficient current flow.

[0911] The holder 24 preferably contains an electrically conductive metal such as nickel, iron, copper, silver, and titanium. The holder 24 can be of any shape as long as the holder can support the collector 23 and can be in the form of a rod, plate, or mesh. The holder 24 is in the form of a plate, for example. A plurality of holders 24 are disposed between the baffle 30 and the down conductor 23. The plurality of holders 24 are aligned so that their surfaces are parallel to each other. The holders 24 are located substantially perpendicular to the baffle 30 and the down conductor 23.

[0912] (Anode side seal and cathode side seal)

The anode side seal is preferably located on the surface of the frame constituting the anode chamber 10. The cathode side seal is preferably positioned on the surface of the frame constituting the cathode chamber 20. The electrolytic cells are interconnected such that the anode side seal in one electrolytic cell and the cathode side seal the adjacent electrolytic cell is laid with an ion exchange membrane 2 (see Figure 104). These seals can create airtightness at the junctions when a plurality of electrolytic cells 1 are connected in series through an ion exchange membrane 2.

[0913] The seals form a seal between the ion exchange membrane and the electrolytic cells. Specific examples of seals include picture frame-like rubber sheets in the center of which an opening is formed. The seals must be resistant to corrosive electrolyte solutions or generated gas and be functional for a long period of time. Thus, with regard to chemical resistance and hardness, vulcanized products and peroxide-crosslinked products of ethylene-propylene-diene rubber (EPDM-rubber) and ethylene-propylene rubber (EPM-rubber) are usually used as seals. Alternatively, if necessary, seals can be used in which the area in contact with the liquid (the area in contact with the liquid) is coated with a fluorine resin such as polytetrafluoroethylene (PTFE) and copolymers of tetrafluoroethylene and perfluoroalkyl vinyl ethers (PFA). These seals may in each case have an opening that does not impede the flow of the electrolyte solution, and the shape of the opening is not particularly limited. For example, a seal in the form of a picture frame is attached by means of an adhesive or the like along the peripheral edge of each opening of the anode chamber frame constituting the anode compartment 10 or the cathode compartment frame constituting the cathode compartment 20. Then, for example, in the case where two electrolytic cells 1 are connected through an ion exchange membrane 2 (see Figure 104), each electrolytic cell 1 to which a seal is attached must be sealed by means of an ion exchange membrane 2. This seal can prevent electrolyte solution, alkali metal hydroxide, chlorine gas, hydrogen gas from escaping from the electrolytic cells 1 and the like formed by electrolysis.

[0914] [Laminated Product]

The electrolysis electrode in the present embodiment is used as a laminated article with a membrane such as an ion exchange membrane or a microporous membrane. That is, the laminated article in the present embodiment contains an electrolysis electrode and a new membrane. The new membrane is not particularly limited as long as it is separate from the membrane in the existing cell, and a variety of known "membranes" can be used. The material, shape, physical properties, and the like of the new membrane may be similar to those of the existing electrolyzer. Specific examples of the electrolysis electrode and membrane will be described in detail below.

[0915] (Stage (A))

In step (A) of the present embodiment, the electrolysis electrode and the new membrane are combined at a temperature at which the membrane does not melt, thereby obtaining a laminated article.

The “temperature at which the membrane does not melt” can be identified as the softening point of the new membrane. The temperature may vary depending on the material constituting the membrane, but preferably ranges from 0 to 100 ° C, more preferably from 5 to 80 ° C, even more preferably from 10 to 50 ° C.

The above combination is preferably performed at normal pressure.

[0916] As a specific example of the above combination, which is not specifically limited, all types of methods can be used except for typical membrane melting methods such as thermal compression. One preferred example is a method in which a liquid is placed between the electrolysis electrode below and a membrane and the surface tension of the liquid is used to combine the electrode and the “membrane”.

[0917] [Stage (B)]

In step (B) in the present embodiment, the membrane in the existing electrolytic cell is replaced with a laminated body after step (A). The replacement method is not particularly limited, and examples thereof include a method in which first, in an existing electrolytic cell, adjacent electrolytic cells and an ion exchange membrane are released from a fixed state with a pressing device, providing a gap between the electrolytic cell and the ion exchange membrane, then the existing ion exchange membrane to be renewed is removed, the laminate and the membrane are then inserted into the gap and reattached by the pressing device. By this method, the laminated article can be placed on the anode or cathode surface of an existing cell and the characteristics of the ion exchange membrane and the anode and / or cathode can be restored.

[0918] [Electrolysis Electrode]

In the present embodiment, the electrode for electrolysis is not particularly limited as long as the electrode can be combined with a new membrane as above, that is, be suitable for integration. The electrolysis electrode can be an electrode that serves as a cathode in electrolysis, or it can be an electrode that serves as an anode. As for the material, shape, and the like of the electrolysis electrode, suitable ones can be appropriately selected in consideration of steps (A) and (B), the configuration of the electrolytic cell and the like in the present embodiment. Preferred aspects of the electrolysis electrode in the present embodiment will be described below, but they are only exemplary aspects preferable to be combined with the new membrane. Electrolysis electrodes other than the following aspects can be appropriately used.

[0919] The electrode for electrolysis in the present embodiment has a force applied per unit mass · unit area, preferably 1.6 N / (mg · cm ² ) or less, more preferably less than 1.6 N / (mg · cm ² ) , further preferably less than 1.5 N / (mg cm ² ), even more preferably 1.2 N / (mg cm ² ) or less, even more preferably 1.20 N / (mg cm ² ) or less with from the point of view of providing good workability and good adhesion to a membrane such as an ion exchange membrane and a microporous membrane, with a supply conductor (a worn electrode and an electrode not having a catalytic coating) and the like. The applied force is even more preferably 1.1 N / (mg cm ² ) or less, further more preferably 1.10 N / (mg cm ² ) or less, even more preferably 1.0 N / (mg cm ²⁾ ) or less, even more preferably 1.00 N / (mg · cm ² ) or less.

From the viewpoint of further improving the electrolysis productivity, the force is preferably more than 0.005 N / (mg cm ² ), more preferably 0.08 N / (mg cm ² ) or more, further preferably 0.1 N / (mg cm ² ) or more, even more preferably 0.14 N / (mg · cm ² ) or more. Even more preferably, the force is 0.2 N / (mg · cm ² ) or more from the viewpoint of further facilitating the handling of a large size (eg, 1.5 mx 2.5 m).

The above-described applied force may be within the above-described range by appropriately adjusting, for example, the below-described open porosity ratio, electrode thickness, arithmetic mean of surface roughness, and the like. For example, more specifically, a higher open porosity ratio results in a lower applied force, and a lower open porosity ratio results in a higher applied force.

The mass per unit area is preferably 48 mg / cm ² or less, more preferably 30 mg / cm ² or less, even more preferably 20 mg / cm ² or less from the standpoint of providing good processability and good adhesion to the membrane, such as an ion exchange membrane and a microporous membrane, with a worn electrode, with a feed conductor not having a catalytic coating, and economy, and moreover, is preferably 15 mg / cm ² or less, for general reasons including manufacturability, adhesion strength and economy. The lower limit is not particularly limited, but is, for example, on the order of 1 mg / cm ² .

The above-described mass per unit area may be within the above-described range, for example, by appropriately adjusting the below-described open porosity ratio, electrode thickness, and the like. More specifically, for example, when the thickness is constant, a higher open porosity ratio results in a decrease in mass per unit area, and a lower open porosity ratio results in a higher mass per unit area.

[0920] The applied force can be measured by methods (i) or (ii) described below, which are set out in more detail in the Examples. With regard to the applied force, the value obtained by measurement by method (i) (also called “applied force (1)” ") and the value obtained by measurement by method (ii) (also called" applied force (2) ”") , can be the same or different, and each of the values is preferably less than 1.5 N / (mg · cm ² ).

[0921] [Method (i)]

Nickel plate blasted with alumina 320 grit (thickness 1.2 mm, square with side 200 mm), ion-exchange membrane obtained by applying particles of inorganic material and a binder to both surfaces of a perfluorocarbon polymer into which an ion-exchange group is introduced (square with a side of 170 mm, the details of the ion exchange membrane specified here are described in the Examples), and a sample electrode (square with a side of 130 mm) is layered in that order. Thereafter, the laminated product is sufficiently immersed in clean water, and excess water deposited on the surface of the laminated product is removed to obtain a sample for measurement. The arithmetic mean (Ra) of the surface roughness of a nickel plate after blasting is 0.5 to 0.8 μm. A specific method for calculating the arithmetic mean (Ra) of the surface roughness is as described in the Examples.

Under the condition of temperature 23 ± 2 ° C and relative humidity 30 ± 5%, only the electrode sample in this measurement sample is lifted in the vertical direction at a speed of 10 mm / minute using a tensile compression machine and the load is measured when the electrode sample is lifted 10 mm vertically. This measurement is repeated three times and the average is calculated.

This average value is divided by the area of the overlapping area of the electrode sample and the ion exchange membrane and by the mass of the ion exchange membrane in the area of overlapping with the electrode sample to calculate the applied force per unit mass · unit area (1) (N / (mg · cm ² )).

[0922] The applied force per unit mass · unit area (1) obtained by method (i) is preferably 1.6 N / (mg · cm ² ) or less, more preferably less than 1.6 N / (mg · cm ² ), further preferably less than 1.5 N / (mg cm ² ), even more preferably 1.2 N / (mg cm ² ) or less, even more preferably 1.20 N / (mg cm ² ) or less in terms of providing good processability and good adhesion to a membrane such as an ion exchange membrane or a microporous membrane, a worn electrode, and an uncatalyzed supply conductor. The applied force is even more preferably 1.1 N / (mg cm ² ) or less, further more preferably 1.10 N / (mg cm ² ) or less, particularly preferably 1.0 N / (mg cm ² ) or less, particularly preferably 1.00 N / (mg · cm ² ) or less. The force is preferably more than 0.005 N / (mg cm ² ), more preferably 0.08 N / (mg cm ² ) or more, further preferably 0.1 N / (mg cm ² ) or more in view of further improvement electrolysis productivity, and, moreover, more preferably 0.14 N / (mg cm ² ), even more preferably 0.2 N / (mg cm ² ) or more from the standpoint of further facilitating handling of loading and unloading at a large size (for example, size 1.5 mx 2.5 m).

[0923] [Method (ii)]

A nickel plate blasted with alumina 320 grit (thickness 1.2 mm, square with a side of 200 mm, a nickel plate similar to the plate in the above method (i)), and an electrode sample (square with a side of 130 mm) is layered in this okay. Thereafter, the laminated product is sufficiently immersed in clean water, and excess water deposited on the surface of the laminated product is removed to obtain a sample for measurement. Under the condition of temperature 23 ± 2 ° C and relative humidity 30 ± 5%, only the electrode sample in this measurement sample is lifted in the vertical direction at a speed of 10 mm / minute using a tensile compression machine and the load is measured when the electrode sample is lifted 10 mm vertically. This measurement is repeated three times and the average is calculated.

This average value is divided by the area of the overlapping area of the electrode sample and the nickel plate and by the weight of the electrode sample in the overlapping area with the nickel plate to calculate the applied force per unit mass · unit area (2) (N / (mg · cm ² )).

[0924] The applied force per unit mass · unit area (2) obtained by method (ii) is preferably 1.6 N / (mg · cm ² ) or less, more preferably less than 1.6 N / (mg · cm ² ), further preferably less than 1.5 N / (mg cm ² ), even more preferably 1.2 N / (mg cm ² ) or less, even more preferably 1.20 N / (mg cm ² ) or less in terms of providing good processability and good adhesion to a membrane such as an ion exchange membrane or a microporous membrane, a worn electrode, and an uncatalyzed supply conductor. The applied force is even more preferably 1.1 N / (mg cm ² ) or less, further more preferably 1.10 N / (mg cm ² ) or less, particularly preferably 1.0 N / (mg cm ² ) or less, particularly preferably 1.00 N / (mg · cm ² ) or less. In addition, the force is preferably more than 0.005 N / (mg cm ² ), more preferably 0.08 N / (mg cm ² ) or more, further preferably 0.1 N / (mg cm ² ) or more from the point in view of further improving the electrolysis productivity, and, moreover, is more preferably 0.14 N / (mg cm ² ) or more from the standpoint of further facilitating the handling of a large size (for example, 1.5 m × 2.5 m).

[0925] The electrolysis electrode of the present embodiment preferably comprises an electrolysis electrode support and a catalyst layer. The thickness of the electrode substrate for electrolysis (measured thickness) is, but is not particularly limited, preferably 300 μm or less, more preferably 205 μm or less, even more preferably 155 μm or less, further preferably 135 μm or less, even more preferably 125 μm or less, even more preferably 120 μm or less, even more preferably 100 μm or less from the point of view of ensuring good processability, achieving good adhesion to a membrane such as an ion exchange membrane or a microporous membrane, with a worn electrode (supply conductor) and an electrode ( feed conductor), which does not have a catalytic coating, being suitable for roll-up and satisfactory folding into folds and facilitates loading and unloading at a large size (for example, size 1.5 mx 2.5 m), and, in addition, still more preferably 50 µm or less in terms of processability and economy. The lower limit is not particularly limited, but is, for example, 1 µm, preferably 5 µm, more preferably 15 µm.

[0926] In the present embodiment, in order to combine the new membrane and the electrolysis electrode, a liquid is preferably interposed therebetween. Any liquid such as water or organic solvents can be used as the liquid, provided that the liquid creates surface tension. The higher the surface tension of the liquid, the greater the force applied between the new membrane and the electrolysis electrode. Thus, a liquid having a higher surface tension is preferred. Examples of liquid include the following (the numerical value in parentheses represents the surface tension of the liquid at 20 ° C):

hexane (20.44 mN / m), acetone (23.30 mN / m), methanol (24.00 mN / m), ethanol (24.05 mN / m), ethylene glycol (50.21 mN / m) and water (72.76 mN / m).

The liquid having a high surface tension allows the new membrane and the electrolysis electrode to be combined (to form a laminated article), thereby facilitating the renewal of the electrode. The liquid between the new membrane and the electrolysis electrode may be present in such an amount that both of them adhere to each other under the action of surface tension. As a result, after placing the layered article in the electrolytic cell, the liquid, if mixed with the electrolyte solution, does not affect the electrolysis itself due to the small amount of liquid.

From a practical point of view, a liquid having a surface tension of 24 mN / m to 80 mN / m such as ethanol, ethylene glycol and water is preferably used as the liquid. Particularly preferred is water or an aqueous alkali solution obtained by dissolving caustic soda, potassium hydroxide, lithium hydroxide, sodium hydrogencarbonate, potassium hydrogencarbonate, sodium carbonate, potassium carbonate or the like in water. Alternatively, the surface tension can be adjusted by bringing these fluids into contact with a surfactant. When a surfactant is contained, the bond strength between the new membrane and the electrolysis electrode changes, allowing for customization of workability. The surfactant is not particularly limited, and both ionic surfactants and nonionic surfactants can be used.

[0927] The proportion measured by the following method (2) on the electrode for electrolysis in the present embodiment is not particularly limited, but is preferably 90% or more, more preferably 92% or more from the viewpoint of ensuring good workability and achieving good adhesion strength with membrane, such as an ion exchange membrane or a microporous membrane, with a worn electrode (supply conductor) and an electrode (supply conductor) not having a catalytic coating, and additionally preferably 95% or more from the point of view of further facilitating loading and unloading at a large size (for example , size 1.5 m × 2.5 m). The upper limit value is 100%.

[0928] [Method (2)]

An ion exchange membrane (170 mm square) and an electrode sample (130 mm square) are layered in this order. The laminated product is placed on the curved surface of a polyethylene pipe (outer diameter: 280 mm) so that the electrode sample in this laminated product is positioned outside at a temperature of 23 ± 2 ° C and a relative humidity of 30 ± 5%, the laminated product and the pipe are sufficiently immersed into clean water, remove the excess water deposited on the surface of the laminated product and the pipe, and then, one minute after this removal, measure the fraction (%) of the area of the area in which the ion-exchange membrane (square with a side of 170 mm) is in close contact with electrode.

[0929] The proportion measured by the following method (3) on the electrode for electrolysis in the present embodiment is not particularly limited, but is preferably 75% or more, more preferably 80% or more from the viewpoint of ensuring good workability, achieving good adhesion strength with membrane, such as an ion exchange membrane or a microporous membrane, with a worn electrode (supply conductor) and an electrode (supply conductor) not having a catalytic coating, and for proper roll-winding and satisfactory creasing, and is additionally preferably 90% or more from the point of view of additional facilitation of loading and unloading at a large size (for example, size 1.5 m × 2.5 m). The upper limit value is 100%.

[Method (3)]

An ion exchange membrane (170 mm square) and an electrode sample (130 mm square) are layered in this order. The laminated product is placed on the curved surface of a polyethylene pipe (outer diameter: 145 mm) so that the electrode sample in this laminated product is positioned externally at a temperature of 23 ± 2 ° C and a relative humidity of 30 ± 5%, the laminated product and the pipe are sufficiently immersed into clean water, remove the excess water deposited on the surface of the laminated product and the pipe, and then, one minute after this removal, measure the fraction (%) of the area of the area in which the ion-exchange membrane (square with a side of 170 mm) is in close contact with electrode.

[0930] The electrode for electrolysis in the present embodiment has, but is not limited to, a porous structure and an open porosity ratio or void ratio of 5 to 90% or less in terms of ensuring good processability, achieving good adhesion to a membrane such as ion exchange a membrane or microporous membrane, with a worn electrode (supply conductor) and an electrode (supply conductor) not having a catalytic coating, and preventing the accumulation of gas evolved during electrolysis, although not specifically limited thereto. The open porosity ratio is more preferably 10 to 80% or less, more preferably 20 to 75%.

The open porosity ratio is the fraction of the lumen areas per unit volume. The calculation method may differ depending on whether sub-micron-sized gaps are considered or only visible gaps are considered. In the present embodiment, the volume V was calculated from the values of the measured thickness, the width and the length of the electrode, and in addition, the weight W was measured to thereby calculate the open porosity coefficient A by the following formula.

A = (1– (W / (V × ρ)) × 100

ρ is the density of the electrode material (g / cm ³ ). For example, the ρ of nickel is 8.908 g / cm ³ and the ρ of titanium is 4.506 g / cm ³ . The open porosity ratio is appropriately controlled by changing the area of perforated metal per unit area in the case of a perforated metal sheet, changing the values of SW (short diameter), LW (long diameter), and feed in the case of expanded metal sheet, changing the linear dimensions of the diameter of the metal fiber, and sieve numbers in the case of a mesh, a change in the photoresist pattern used in the case of electrospinning, a change in the diameter of the metal fiber and the density of the fiber in the case of a nonwoven fabric, a change in the mold for forming cavities in the case of a porous metal, or the like.

[0931] Hereinafter, a more specific embodiment of the electrode for electrolysis in the present embodiment will be described.

The electrolysis electrode of the present embodiment preferably comprises an electrolysis electrode support and a catalyst layer. The catalyst bed can be composed of multiple layers, as shown below, or can have a single layer configuration.

As shown in FIG. 108, the electrolysis electrode 100 of the present embodiment includes an electrolysis electrode substrate 10 and a pair of first layers 20 that cover both surfaces of the electrolysis electrode substrate 10. The first layers 20 preferably cover the entire electrode substrate 10 for electrolysis. Apparently, this coating increases the catalytic activity and durability of the electrode. One first layer 20 can only be laminated to one surface of the electrolysis electrode substrate 10.

In addition, as shown in Figure 108, the surfaces of the first layers 20 may be covered with the second layers 30. The first layers 20 are preferably covered with the second layers 30 in their entirety. Alternatively, one second layer 30 may be laminated to only one surface of the first layer 20.

[0932] (Electrode support for electrolysis)

As the electrode substrate 10 for electrolysis, for example, nickel, nickel alloys, stainless steel, and, in addition, valve metals, including titanium, can be used, although not limited thereto. Substrate 10 preferably contains at least one element selected from nickel (Ni) and titanium (Ti).

When stainless steel is used in an aqueous alkali solution of high concentration, iron and chromium are washed out and the electrical conductivity is in the order of one tenth that of nickel. In view of the above, as the electrode substrate for electrolysis, a substrate containing nickel (Ni) is preferable.

Alternatively, when the electrode substrate 10 for electrolysis is used in a brine with a high concentration close to saturation, in an atmosphere in which chlorine gas is generated, the material of the electrode substrate 10 is also preferably titanium having high corrosion resistance.

The shape of the electrode substrate 10 for electrolysis is not particularly limited, and a shape suitable for this purpose can be selected. As the mold, any of a perforated metal sheet, a nonwoven fabric, a porous metal, an expanded metal sheet, an electrospinning metal porous foil, a so-called woven metal mesh, and the like can be used. Of these, perforated metal sheet or expanded metal sheet is preferable. Electrospinning is a method of producing a thin metal foil having a precisely shaped pattern using photolithography and electrodeposition in combination. It is a method involving patterning a substrate with a photoresist and electrodeposition of a portion not protected by the resist to form a metal thin film.

With regard to the shape of the electrode support for electrolysis, a suitable specification depends on the distance between the anode and the cathode in the electrolysis cell. In the case where the distance between the anode and the cathode is finite, the shape of an expanded metal sheet or a perforated metal sheet can be used, and in the case of a so-called zero-gap electrolyzer in which the ion exchange membrane is in contact with the electrode, a formed interlacing of fine metal filaments woven metal mesh, wire mesh, porous metal, metal nonwoven fabric, expanded metal sheet, perforated metal sheet, metal porous foil, and the like, although not limited thereto.

Examples of the electrode substrate 10 for electrolysis include metal porous foil, wire mesh, metal nonwoven fabric, perforated metal sheet, expanded metal sheet, and porous metal.

As the plate material before being processed to form a perforated metal sheet or expanded metal sheet, rolled plate materials and electrolytic foils are preferred. The electrolytic foil is preferably subjected to a further electrodeposition treatment using the same element as its base material as a further treatment to thereby form roughness on one or both of its surfaces.

The thickness of the electrolysis electrode substrate 10 as mentioned above is preferably 300 µm or less, more preferably 205 µm or less, further preferably 155 µm or less, even more preferably 135 µm or less, even more preferably 125 µm or less, even more preferably 120 µm or less, even more preferably 100 µm or less, and further even more preferably 50 µm or less in terms of processability and economy. The lower limit is not particularly limited, but is, for example, 1 µm, preferably 5 µm, more preferably 15 µm.

[0933] In the electrolysis electrode substrate, residual stress during processing is preferably relieved by annealing the electrolysis electrode substrate in an oxidizing atmosphere. It is preferable to form roughness using a steel grid, an alumina grid or the like on the surface of the electrode substrate for electrolysis, followed by acid treatment to increase its surface area in order to improve adhesion to the catalyst layer that is coated on the surface. Alternatively, it is preferable to carry out the electrodeposition treatment using the same element as the substrate to increase the surface area.

[0934] To bring the first layer 20 into intimate contact with the surface of the electrolysis electrode substrate 10, the electrolysis electrode substrate 10 is preferably subjected to a surface area increase treatment. Examples of surface area enhancing treatments include chopped wire blasting, steel grating, alumina grating or the like, acidizing using sulfuric acid or hydrochloric acid, and electrodeposition using the same element as in the substrate. The arithmetic mean (Ra) of the surface roughness on the surface of the substrate is not particularly limited, but is preferably 0.05 µm to 50 µm, more preferably 0.1 to 10 µm, even more preferably 0.1 to 8 µm.

[0935] Next, a case will be described where the electrolysis electrode in the present embodiment is used as an anode for conventional salt electrolysis.

(First layer)

In Figure 108, the first layer 20 contains at least one of ruthenium oxides, iridium oxides and titanium oxides as a catalyst layer. Examples of ruthenium oxide include RuO ₂ . Examples of iridium oxide include IrO ₂ . Examples of titanium oxide include TiO ₂ . The first layer 20 preferably contains two oxides: ruthenium oxide and titanium oxide, or three oxides: ruthenium oxide, iridium oxide and titanium oxide. This makes the first layer 20 more stable and further improves the adhesion to the second layer 30.

[0936] When the first layer 20 contains two oxides: ruthenium oxide and titanium oxide, the first layer 20 preferably contains from 1 to 9 moles, more preferably from 1 to 4 moles of titanium oxide, based on 1 mole of ruthenium oxide contained in the first layer 20 With the compositional ratio of the two oxides in this range, the electrolysis electrode 100 exhibits excellent resistance.

[0937] When the first layer 20 contains three oxides: ruthenium oxide, iridium oxide and titanium oxide, the first layer 20 preferably contains 0.2 to 3 moles, more preferably 0.3 to 2.5 moles of iridium oxide per 1 mol of ruthenium oxide contained in the first layer 20. The first layer 20 preferably contains from 0.3 to 8 moles, more preferably from 1 to 7 moles of titanium oxide, based on 1 mole of ruthenium oxide contained in the first layer 20. With a compositional ratio of three oxides in this range, the electrolysis electrode 100 exhibits excellent resistance.

[0938] When the first layer 20 contains at least two of ruthenium oxide, iridium oxide and titanium oxide, these oxides preferably form a solid solution. The formation of a solid solution of the oxides allows the electrolysis electrode 100 to exhibit excellent resistance.

[0939] In addition to the above-described compositions, oxides of various compositions can be used, provided that at least one of ruthenium oxide, iridium oxide, and titanium oxide is contained. For example, an oxide coating called DSA (R), which contains ruthenium, iridium, tantalum, niobium, titanium, tin, cobalt, manganese, platinum, and the like, can be used as the first layer 20.

[0940] The first layer 20 need not be a single layer and may include multiple layers. For example, the first layer 20 may include a three-oxide layer and a two-oxide layer. The thickness of the first layer 20 is preferably 0.05 to 10 µm, more preferably 0.1 to 8 µm.

[0941] (Second layer)

The second layer 30 preferably contains ruthenium and titanium. This makes it possible to further reduce the electrical overvoltage of chlorine immediately after electrolysis.

[0942] The second layer 30 preferably contains palladium oxide, a solid solution of palladium and platinum oxide, or an alloy of palladium and platinum. This makes it possible to further reduce the electrical overvoltage of chlorine immediately after electrolysis.

[0943] The thicker second layer 30 can maintain the electrolysis performance for a long period of time, but from the standpoint of economy, the thickness is preferably 0.05 to 3 µm.

[0944] Next, a situation will be described where the electrolysis electrode in the present embodiment is used as a cathode for conventional salt electrolysis.

(First layer)

Examples of the components of the first layer 20 as a catalyst layer include elements such as C, Si, P, S, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, In, Sn, Ta, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu, as well as metal oxides and hydroxides.

The first layer 20 may or may not contain at least one of platinum group metals, platinum group metal oxides, platinum group metal hydroxides, and platinum group metal containing alloys.

When the first layer 20 contains at least one of platinum group metals, platinum group metal oxides, platinum group metal hydroxides and alloys containing a platinum group metal, platinum group metals, platinum group metal oxides, platinum group metal hydroxides, and platinum metal containing alloys the groups preferably contain at least one platinum group metal from platinum, palladium, rhodium, ruthenium and iridium.

The platinum group metal is preferably platinum.

As the oxide of the platinum group metal, ruthenium oxide is preferably contained.

As the hydroxide of the platinum group metal, ruthenium hydroxide is preferably contained.

As an alloy of platinum group metals, an alloy of platinum with nickel, iron and cobalt is preferably included.

In addition, if necessary, an oxide or hydroxide of a lanthanide element is preferably contained as the second component. This allows the electrolysis electrode 100 to exhibit excellent resistance.

As the oxide or hydroxide of the lanthanide element, preferably at least one selected from lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium and dysprosium is contained.

In addition, if necessary, a transition metal oxide or hydroxide is preferably contained as the third component.

The addition of the third component allows the electrolysis electrode 100 to exhibit superior resistance and lower electrolysis voltage.

Examples of a preferred combination include only ruthenium, ruthenium + nickel, ruthenium + cerium, ruthenium + lanthanum, ruthenium + lanthanum + platinum, ruthenium + lanthanum + palladium, ruthenium + praseodymium, ruthenium + praseodymium + platinum, ruthenium + praseodymium + platinum + palladium, ruthenium + neodymium, ruthenium + neodymium + platinum, ruthenium + neodymium + manganese, ruthenium + neodymium + iron, ruthenium + neodymium + cobalt, ruthenium + neodymium + zinc, ruthenium + neodymium + gallium, ruthenium + neodymium + sulfur, ruthenium + neodymium + lead , ruthenium + neodymium + nickel, ruthenium + neodymium + copper, ruthenium + samarium, ruthenium + samarium + manganese, ruthenium + samarium + iron, ruthenium + samarium + cobalt, ruthenium + samarium + zinc, ruthenium + samarium + gallium, ruthenium + samarium + sulfur, ruthenium + samarium + lead, ruthenium + samarium + nickel, platinum + cerium, platinum + palladium + cerium, platinum + palladium + lanthanum + cerium, platinum + iridium, platinum + palladium, platinum + iridium + palladium, platinum + nickel + palladium, platinum + nickel + ruthenium, platinum and nickel alloys, platinum and cobalt alloys and platinum and iron alloys.

When platinum-group metals, platinum-group metal oxides, platinum-group metal hydroxides, and platinum-group metal-containing alloys are not contained, the main component of the catalyst is preferably the element nickel.

Preferably, at least one of nickel metal, nickel oxides and hydroxides is contained.

A transition metal can be added as a second component. As the second added component, at least one of titanium, tin, molybdenum, cobalt, manganese, iron, sulfur, zinc, copper and carbon is preferably contained.

Examples of a preferred combination include nickel + tin, nickel + titanium, nickel + molybdenum, and nickel + cobalt.

If necessary, an intermediate layer may be disposed between the first layer 20 and the electrolysis electrode substrate 10. By placing the intermediate layer, the resistance of the electrolysis electrode 100 can be improved.

Preferred as the intermediate layer are those which have an affinity for both the first layer 20 and the electrode substrate 10 for electrolysis. As the intermediate layer, preferred are nickel oxides, platinum group metals, platinum group metal oxides and platinum group metal hydroxides. The intermediate layer can be formed by applying and firing a solution containing the component that forms the intermediate layer. Alternatively, a surface oxide layer can also be formed by subjecting the substrate to heat treatment at a temperature of 300 to 600 ° C. in an air atmosphere. In addition, this layer can be formed by a known method such as a thermal spraying method and an ionic deposition method.

[0945] (Second layer)

Examples of the components of the first layer 30 as a catalyst layer include elements such as C, Si, P, S, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, In, Sn, Ta, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu, as well as metal oxides and hydroxides.

The first layer 30 may or may not contain at least one of platinum group metals, platinum group metal oxides, platinum group metal hydroxides, and platinum group metal containing alloys. Examples of a preferred combination of elements contained in the second layer include those listed for the first layer. The combination of the first layer and the second layer can be a combination in which the compositions are the same and the compositional ratios are different, or it can be a combination of different compositions.

[0946] With regard to the thickness of the catalyst layer, the total thickness of the formed catalyst layer and the intermediate layer is preferably 0.01 µm to 20 µm. With a thickness of 0.01 µm or more, the catalyst layer can sufficiently serve as a catalyst. With a thickness of 20 µm or less, a strong catalyst layer can be formed that is unlikely to separate from the support. The thickness is more preferably 0.05 µm to 15 µm. The thickness is more preferably 0.1 to 10 µm. Even more preferably, the thickness is 0.2 to 8 µm.

[0947] The thickness of the electrode, that is, the combined thickness of the electrolysis electrode support and the catalyst layer, is preferably 315 µm or less, more preferably 220 µm or less, further preferably 170 µm or less, even more preferably 150 µm or less, particularly preferably 145 µm or less, even more preferably 140 µm or less, even more preferably 138 µm or less, further even more preferably 135 µm or less, in terms of electrode workability. A thickness of 135 µm or less can provide good workability. In addition, for similar reasons as above, the thickness is preferably 130 µm or less, more preferably less than 130 µm, even more preferably 115 µm or less, further more preferably 65 µm or less. The lower limit is not particularly limited, but is preferably 1 µm or more, more preferably 5 µm or more for practical reasons, more preferably 20 µm or more. The thickness of the electrode can be determined by measuring with a digital thickness gauge (from Mitutoyo Corporation, minimum scale 0.001 mm). The thickness of the substrate of the electrolysis electrode can be measured in the same manner as in the case of the electrode. The thickness of the catalyst layer can be determined by subtracting the thickness of the electrolysis electrode support from the thickness of the electrode.

[0948] In the present embodiment, the electrode for electrolysis preferably contains at least one catalyst component selected from the group consisting of Ru, Rh, Pd, Ir, Pt, Au, Ti, V, Cr, Mn, Fe, Co, Ni , Cu, Zn, Y, Zr, Nb, Mo, Ag, Ta, W, Re, Os, Al, In, Sn, Sb, Ga, Ge, B, C, N, O, Si, P, S, La , Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb and Dy, from the standpoint of achieving sufficient electrolysis performance.

[0949] In the present embodiment, from the considerations that the electrode for electrolysis of the present embodiment, if it is an electrode having a wide elastic deformation range, can provide better workability and has better adhesion to a membrane such as an ion exchange membrane or microporous membrane, with a worn electrode, with a supply conductor not having a catalytic coating, and the like, the thickness of the electrode for electrolysis is preferably 315 μm or less, more preferably 220 μm or less, even more preferably 170 μm or less, even more preferably 150 µm or less, particularly preferably 145 µm or less, even more preferably 140 µm or less, further still more preferably 138 µm or less, even more preferably 135 µm or less. A thickness of 135 µm or less can provide good workability. In addition, for reasons similar to the above, the thickness is preferably 130 µm or less, more preferably less than 130 µm, further preferably 115 µm or less, even more preferably 65 µm or less. The lower limit is not particularly limited, but is preferably 1 µm or more, more preferably 5 µm or more for practical reasons, more preferably 20 µm or more. In the present embodiment, “having a wide elastic range” means that when the electrolysis electrode is wound to form a winding, it is unlikely that winding-induced warping will occur after being released from the wound state. The thickness of the electrolysis electrode when the below-mentioned catalyst layer is provided refers to the total thickness of both the electrolysis electrode support and the catalyst layer.

[0950] (Method for Manufacturing Electrolysis Electrode)

Next, one embodiment of a method for manufacturing an electrode 100 for electrolysis will be described in detail.

In the present embodiment, the electrolysis electrode 100 can be obtained by forming a first layer 20, preferably a second layer 30 on the electrolysis electrode substrate by a method such as firing a coating film in an oxygen atmosphere (pyrolysis) or ion deposition, electrodeposition, or thermal sputtering. The production method of the present embodiment as mentioned above can achieve high formation productivity of the electrolysis electrode 100. More specifically, a catalyst layer is formed on the electrode support for electrolysis by an application step in which a coating liquid containing the catalyst is applied, a drying step in which the coating liquid is dried, and a pyrolysis step in which pyrolysis is performed. Pyrolysis here means that a metal salt, which is to be a precursor, decomposes by heating into a metal or metal oxide and a gaseous substance. The decomposition product depends on the nature of the metal used, the type of salt and the atmosphere in which the pyrolysis is carried out, and many metals tend to form oxides in an oxidizing atmosphere. In the industrial process for making an electrode, pyrolysis is usually performed in air and in many cases a metal oxide or metal hydroxide is formed.

[0951] (Formation of the first layer of the anode)

(Application stage)

The first layer 20 is obtained by applying a solution in which at least one metal salt of ruthenium, iridium and titanium (first coating liquid) is dissolved on the electrode substrate for electrolysis, and then pyrolysis (calcining) the coating liquid in the presence of oxygen. The content of ruthenium, iridium and titanium in the first cover liquid is substantially equivalent to that in the first layer 20.

[0952] The metal salts can be chlorides, nitrates, sulfates, metal alkoxides, and any other form. The solvent of the first coating liquid can be selected depending on the type of metal salt, and water and alcohols such as butanol can be used. As the solvent, water or a mixed solvent of water and alcohol is preferred. The total metal concentration in the first coating liquid in which the metal salts are dissolved is not particularly limited, but is preferably in the range of 10 to 150 g / L in consideration of the thickness of the coating film formed by a single application.

[0953] Examples of the method used as the method for applying the first coating liquid to the electrolysis electrode substrate 10 include a method of dipping the electrolysis electrode substrate 10 into the first coating liquid, a method for applying the first coating liquid with a brush, a rolling method using a sponge roller impregnated the first coating liquid, and an electrostatic coating method in which the electrode substrate 10 for electrolysis and the first coating liquid are charged with opposite charges and sputtering is performed. Among them, a rolling method or an electrostatic coating method is preferable, which has excellent production performance on an industrial scale.

[0954] (Drying step and pyrolysis step)

After applying the first coating liquid to the electrode substrate 100 for electrolysis, it is dried at a temperature of 10 to 90 ° C and subjected to pyrolysis in a roasting furnace heated to a temperature of 350 to 650 ° C. Between drying and pyrolysis, if necessary, a pre-firing can be performed at a temperature of 100 to 350 ° C. The temperature for drying, pre-firing and pyrolysis is appropriately selected depending on the composition and type of solvent of the first coating liquid. A longer period of pyrolysis time in each step is preferable, but from the viewpoint of productivity of producing an electrode, 3 to 60 minutes, more preferably 5 to 20 minutes are preferable.

[0955] The cycle of the above-described application, drying and pyrolysis is repeated to form a coating (first layer 20) to a predetermined thickness. After the first layer 20 is formed and then further post-baked for an extended period of time as required, this can further increase the stability of the first layer 20.

[0956] (Formation of the second layer)

The second layer 30, which is formed if necessary, is obtained, for example, by applying a solution containing a palladium compound and a platinum compound or a solution containing a ruthenium compound and a titanium compound (second coating liquid) on the first layer 20, and then the coating liquid is subjected to pyrolysis in presence of oxygen.

[0957] (Formation of the first cathode layer by pyrolysis method)

(Application stage)

The first layer 20 is obtained by applying a solution in which metal salts in various combinations are dissolved (first coating liquid) on an electrode substrate for electrolysis, and then pyrolysis (calcining) the coating liquid in the presence of oxygen. The metal content in the first coating liquid is substantially equivalent to that in the first layer 20.

[0958] The metal salts can be chlorides, nitrates, sulfates, metal alkoxides, and any other form. The solvent of the first coating liquid can be selected depending on the type of metal salt, and water and alcohols such as butanol can be used. As the solvent, water or a mixed solvent of water and alcohol is preferred. The total metal concentration in the first coating liquid in which the metal salts are dissolved is not particularly limited, but is preferably in the range of 10 to 150 g / L in consideration of the thickness of the coating film formed by a single application.

[0959] Examples of the method used as the method for applying the first coating liquid to the electrolysis electrode substrate 10 include a method of dipping the electrolysis electrode substrate 10 into the first coating liquid, a method for applying the first coating liquid with a brush, a rolling method using a sponge roller impregnated the first coating liquid, and an electrostatic coating method in which the electrode substrate 10 for electrolysis and the first coating liquid are charged with opposite charges and sputtering is performed. Among them, a rolling method or an electrostatic coating method is preferable, which has excellent production performance on an industrial scale.

[0960] (Drying step and pyrolysis step)

After applying the first coating liquid to the electrode substrate 100 for electrolysis, it is dried at a temperature of 10 to 90 ° C and subjected to pyrolysis in a roasting furnace heated to a temperature of 350 to 650 ° C. Between drying and pyrolysis, if necessary, a pre-firing can be performed at a temperature of 100 to 350 ° C. The temperature for drying, pre-firing and pyrolysis is appropriately selected depending on the composition and type of solvent of the first coating liquid. A longer period of pyrolysis time in each step is preferable, but from the viewpoint of productivity of producing an electrode, 3 to 60 minutes, more preferably 5 to 20 minutes are preferable.

[0961] The cycle of the above-described application, drying and pyrolysis is repeated to form a coating (first layer 20) to a predetermined thickness. After the first layer 20 is formed and then further post-baked for an extended period of time as required, this can further increase the stability of the first layer 20.

[0962] (Interlayer Formation)

The intermediate layer, which is formed, if necessary, is obtained, for example, by applying a solution containing a palladium compound or a platinum compound (second coating liquid) to a substrate, and then pyrolysis of the coating liquid in the presence of oxygen. Alternatively, the nickel oxide intermediate layer can be formed on the surface of the substrate by heating the substrate only, without applying a solution thereto.

[0963] (Formation of the first cathode layer by ion deposition)

The first layer 20 can also be formed by ion deposition.

The example comprises a method in which a substrate is fixed in a chamber and a ruthenium metal target is irradiated with an electron beam. Particles of vaporized metallic ruthenium are positively charged in the plasma in the chamber, deposited on a negatively charged substrate. The plasma atmosphere is argon and / or oxygen and ruthenium is deposited on the substrate as ruthenium oxide.

[0964] (Formation of the first layer of the cathode by electrodeposition)

The first layer 20 can also be formed by electrodeposition.

As an example, when the substrate is used as a cathode and is subjected to plating in an electrolyte solution containing nickel and tin, an electrolytic plating of a nickel-tin alloy can be formed.

[0965] (Formation of the first layer of the cathode by thermal spraying)

The first layer 20 can also be formed by thermal spraying.

By way of example, nickel oxide particles sprayed by plasma onto a substrate may form a catalyst bed in which nickel metal and nickel oxide are mixed.

[0966] Next, an ion exchange membrane according to one aspect of the membrane will be described in detail.

[Ion exchange membrane]

The ion exchange membrane is not particularly limited as long as the membrane can be laminated with an electrolysis electrode and a variety of ion exchange membranes can be used. In the present embodiment, an ion exchange membrane is preferably used which has a membrane body containing a hydrocarbon polymer or a fluorine-containing polymer having an ion exchange group and a coating layer provided on at least one surface of the membrane body. It is preferable that the coating layer contains particles of inorganic material and a binder, and the specific surface area of the coating layer is 0.1 to 10 m ² / g. In an ion exchange membrane having such a structure, the effect of gas evolved during electrolysis on the electrolysis performance is small, and stable electrolysis performance can be demonstrated.

The above-described fluoropolymer ion exchange membrane into which an ion exchange group has been introduced contains one of either a sulfonic acid layer having an ion exchange group derived from a sulfo group (a group represented by —SO ₃ ^- , hereinafter also referred to as a “sulfonic acid group”), or a carboxylic acid layer having an ion exchange group derived from a carboxyl group (a group represented as —CO ₂ ^- , hereinafter also referred to as a “carboxylic acid group”). From the point of view of strength and dimensional stability, it is preferable to additionally include core reinforcing materials.

The inorganic material particles and the binder will be described in detail below in the coating layer description section.

[0967] Figure 109 illustrates a schematic sectional view showing one embodiment of an ion exchange membrane. The ion exchange membrane 1 has a membrane body 10 containing a hydrocarbon polymer or a fluorine-containing polymer having an ion exchange group, and coating layers 11a and 11b formed on both surfaces of the membrane body 10.

[0968] In the ion exchange membrane 1, the membrane body 10 includes a sulfonic acid layer 3 having an ion exchange group derived from a sulfo group (a group represented by —SO ₃ ^- , hereinafter also referred to as a “sulfonic acid group”), and a carboxylic acid layer 2, having an ion exchange group derived from a carboxyl group (a group represented by —CO ₂ ^- , hereinafter also referred to as a “carboxylic acid group”), and core reinforcing materials 4 that increase strength and dimensional stability. An ion exchange membrane 1 including a sulfonic acid layer 3 and a carboxylic acid layer 2 is suitably used as an anion exchange membrane.

[0969] The ion exchange membrane may include one of a sulfonic acid layer and a carboxylic acid layer. The ion exchange membrane does not need to be reinforced with core reinforcing materials, and the order of placement of the core reinforcing materials is not limited to the example in FIG. 109.

[0970] (Membrane Body)

First, the membrane body 10 constituting the ion exchange membrane 1 will be described.

The body 10 of the membrane should be such that its function is to provide selective permeation of cations, and contains a hydrocarbon polymer or a fluorine-containing polymer having an ion exchange group. Its configuration and material are not particularly limited, and preferable ones can be appropriately selected.

[0971] The hydrocarbon polymer or fluorine-containing polymer having an ion exchange group in the membrane body 10 can be obtained from a hydrocarbon polymer or fluorine-containing polymer having an ion exchange group precursor capable of forming an ion exchange group by hydrolysis or the like. More specifically, for example, after a polymer containing a fluorinated hydrocarbon backbone having a side chain that is converted to an ion exchange group by hydrolysis or the like (ion exchange group precursor) is used to obtain a precursor of the membrane body 10, and melt-processable ( below in some cases referred to as "fluoropolymer (s)" ""), the membrane body 10 can be obtained by converting a precursor of an ion exchange group into an ion exchange group.

[0972] The fluorine-containing polymer (s) can be obtained, for example, by copolymerizing at least one monomer selected from the next first group and at least one monomer selected from the next second group and / or the next third group. The fluorine-containing polymer (s) can also be obtained by homopolymerizing one monomer selected from any of the next first group, the next second group, and the next third group.

[0973] Examples of monomers of the first group include vinyl fluoride compounds. Examples of vinyl fluoride compounds include vinyl fluoride, tetrafluoroethylene, hexafluoropropylene, vinylidene fluoride, trifluoroethylene, chlorotrifluoroethylene, and perfluoroalkyl vinyl ethers. In particular, when an ion exchange membrane is used as a membrane for alkaline electrolysis, the vinyl fluoride compound is preferably a perfluorinated monomer, and a perfluorinated monomer selected from the group consisting of tetrafluoroethylene, hexafluoropropylene and perfluoroalkyl vinyl ethers is preferred.

[0974] Examples of monomers of the second group include vinyl compounds having a functional group convertible to an ion exchange group of the carboxylic acid type (carboxylic acid group). Examples of vinyl compounds having a functional group convertible to a carboxylic acid ion exchange group include monomers represented by the formula CF ₂ = CF (OCF ₂ CYF) _s –O (CZF) _t –COOR, in which s is an integer from 0 to 2, t is an integer from 1 to 12, each of Y and Z is independently F or CF ₃ and R is a lower alkyl group (a lower alkyl group is an alkyl group having, for example, 1 to 3 carbon atoms).

[0975] Among them, preferred are compounds represented by the formula CF ₂ = CF (OCF ₂ CYF) _n —O (CF ₂ ) _m —COOR, in which n represents an integer from 0 to 2, m represents an integer from 1 to 4, Y is F or CF ₃ and R is CH ₃ , C ₂ H ₅ or C ₃ H ₇ .

[0976] When an ion exchange membrane is used as a cation exchange membrane for alkaline electrolysis, the perfluoro compound is preferably used at least as a monomer, but the alkyl group (see R values above) of the ester group is lost from the polymer during hydrolysis, and therefore the alkyl group (R) is not must necessarily be a perfluoroalkyl group in which all hydrogen atoms are replaced by fluorine atoms.

[0977] Of the above monomers, the following monomers are more preferred as monomers of the second group:

CF ₂ = CFOCF ₂ –CF (CF ₃ ) OCF ₂ COOCH ₃ ,

CF ₂ = CFOCF ₂ CF (CF ₃ ) O (CF ₂ ) ₂ COOCH ₃ ,

CF ₂ = CF [OCF ₂ –CF (CF ₃ )] ₂ O (CF ₂ ) ₂ COOCH ₃ ,

CF ₂ = CFOCF ₂ CF (CF ₃ ) O (CF ₂ ) ₃ COOCH ₃ ,

CF ₂ = CFO (CF ₂ ) ₂ COOCH ₃ and

CF ₂ = CFO (CF ₂ ) ₃ COOCH ₃ .

[0978] Examples of monomers of the third group include vinyl compounds having a functional group convertible to an ion exchange group of the sulfone type (sulfonic acid group). As vinyl compounds having a functional group convertible to a sulfonic acid ion exchange group, for example, monomers represented by the formula CF ₂ = CFO — X — CF ₂ —SO ₂ F in which X is a perfluoroalkylene group are preferred. Specific examples include the following monomers:

CF ₂ = CFOCF ₂ CF ₂ SO ₂ F,

CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₂ F,

CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ CF ₂ SO ₂ F,

CF ₂ = CF (CF ₂ ) ₂ SO ₂ F,

CF ₂ = CFO [CF ₂ CF (CF ₃ ) O] ₂ CF ₂ CF ₂ SO ₂ F and

CF ₂ = CFOCF ₂ CF (CF ₂ OCF ₃ ) OCF ₂ CF ₂ SO ₂ F.

[0979] Among them, CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ CF ₂ SO ₂ F and CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₂ F are more preferable.

[0980] The copolymer obtained from these monomers can be formed by a polymerization method designed for homopolymerization and copolymerization of ethylene fluoride, in particular, a general polymerization method used for tetrafluoroethylene. For example, in a method using a non-aqueous medium, the polymerization reaction can be carried out in the presence of a free radical polymerization initiator such as a perfluorocarbon peroxide or an azo compound, under conditions of a temperature of 0 to 200 ° C and a pressure of 0.1 to 20 MPa, using an inert solvent, such as a perfluorocarbon or a chlorofluorocarbon.

[0981] In the above copolymerization, the type of combination of the above monomers and their proportions are not particularly limited and are determined depending on the type and amount of functional groups that it is desirable to introduce into the resulting fluorine-containing polymer. For example, when a fluorine-containing polymer containing only a carboxylic acid group is produced, at least one polymer must be selected from each of the above-described first group and second group and copolymerized. In addition, when a fluorine-containing polymer containing only a sulfonic acid group is prepared, at least one polymer must be selected from each of the first group and the third group, and copolymerized. In addition, when a fluorine-containing polymer having a carboxylic acid group and a sulfonic acid group is produced, at least one monomer must be selected from each of the above-described first group, second group and third group and copolymerized. In this case, the target fluorine-containing polymer can also be obtained by separately forming a copolymer including monomers of the above-described first group and second group, and a copolymer including monomers of the above-described first group and third group, and then mixing these copolymers. The composition of the mixture of monomers is not particularly limited, and when the number of functional groups per structural unit of the polymer increases, the proportion of monomers selected from the above-described second group and third group must increase.

[0982] The total ion exchange capacity of the fluorine-containing copolymer is not particularly limited, but is preferably 0.5 to 2.0 mg⋅eq / g, more preferably 0.6 to 1.5 mg⋅eq / g. The total ion exchange capacity here refers to the equivalent of the exchange group per unit weight of dry resin and can be measured by neutralization titration or the like.

[0983] In the membrane body 10 of the ion exchange membrane 1, a sulfonic acid layer 3 containing a fluorine-containing polymer having a sulfonic acid group and a carboxylic acid layer 2 containing a fluorine-containing polymer having a carboxylic acid group are laminated. By providing the membrane body 10 having such a layer configuration, the selective permeability to cations such as sodium ions can be further improved.

[0984] The ion exchange membrane 1 is disposed in the electrolytic cell so that generally the sulfonic acid layer 3 is on the anode side of the cell and the carboxylic acid layer 2 is on the cathode side of the cell.

[0985] The sulfonic acid layer 3 is preferably composed of a material having a low electrical resistance and is thicker than the carboxylic acid layer 2 in terms of membrane strength. The thickness of the sulfonic acid layer 3 is preferably 2 to 25 times, more preferably 3 to 15 times the thickness of the carboxylic acid layer 2.

[0986] The carboxylic acid layer 2 preferably has high anion exclusion characteristics, even if it is thin. The anion exclusion characteristics herein refer to the characteristic of hindering the incorporation and penetration of anions into or through the ion exchange membrane 1. In order to improve the anion exclusion characteristics, it is effective to place a carboxylic acid layer having a low ion exchange capacity compared to the sulfonic acid layer.

[0987] As the fluorine-containing polymer for use in the sulfonic acid layer 3, a polymer obtained using CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₂ F is preferred as the third group monomer.

[0988] As the fluorine-containing polymer for use in the carboxylic acid layer 2, a polymer obtained using CF ₂ = CFOCF ₂ CF (CF ₂ ) O (CF ₂ ) ₂ COOCH _{3 is} preferred as the monomer of the second group.

[0989]

(Coating layer)

The ion exchange membrane preferably has a coating layer on at least one surface of the membrane body. As shown in Figure 109, in the ion exchange membrane 1, coating layers 11a and 11b are formed on both surfaces of the membrane body 10.

The coating layers contain particles of inorganic material and a binder.

[0990] The average particle size of the inorganic material is preferably 0.90 µm or more. When the average particle size of the inorganic material is 0.90 µm or more, impurity resistance is greatly improved in addition to gas attachment. That is, by increasing the average particle size of the inorganic material as well as keeping the above-mentioned specific surface area, a particularly noticeable effect can be achieved. Uneven particles of inorganic material are preferred insofar as the above average particle size and specific surface area are satisfied. Melting inorganic material particles and raw ore milling inorganic material particles can be used. Preferably, particles of inorganic material obtained by milling raw ore are used.

[0991] The average particle size of the inorganic material may be 2 µm or less. When the average particle size of the inorganic material is 2 µm or less, damage to the membrane by the inorganic material can be prevented. The average particle size of the inorganic material is more preferably 0.90 to 1.2 µm.

[0992] Here, the average particle size can be measured by a particle size analyzer ("SALD2200", manufactured by SHIMADZU CORPORATION).

[0993] The particles of inorganic material are preferably irregular in shape. Such shapes further improve the resistance to impurities. The particles of inorganic material preferably have a wide particle size distribution.

[0994] The particles of inorganic material preferably contain at least one inorganic material selected from the group consisting of oxides of Group IV elements of the Periodic Table, nitrides of Group IV elements of the Periodic Table, and carbides of Group IV elements of the Periodic Table. From the standpoint of resistance, zirconium oxide particles are more preferable.

[0995] The inorganic material particles are preferably inorganic material particles obtained by grinding raw ore from inorganic material particles, or inorganic material particles in the form of spherical particles having a uniform diameter obtained by refining a raw ore melt from inorganic material particles.

[0996] Examples of means for grinding raw ore include, but are not specifically limited to, ball mills, bead mills, colloid mills, cone grinders, disc mills, runners, grain mills, hammer mills, granulators, vertical shaft impact crushers (VSI ), leather mills (Wiley mills), roller mills and jet mills. After grinding, the particles are preferably washed. As a washing method, the particles are preferably treated with an acid. This treatment can reduce the amount of impurities such as iron adhered to the surface of the inorganic material particles.

[0997] The coating layer preferably contains a binder. The binder is the component that forms the coating layers by retaining particles of inorganic material on the surface of the ion exchange membrane. The binder preferably contains a fluorine-containing polymer from the standpoint of resistance to electrolyte solution and electrolysis products.

[0998] As a binder, a fluorine-containing polymer having a carboxylic acid group or a sulfonic acid group is more preferable in terms of resistance to electrolyte solution and electrolysis products and adhesion strength to the surface of the ion exchange membrane. When the coating layer is provided on a layer containing a fluorine-containing polymer having a sulfonic acid group (sulfonic acid layer), the fluorine-containing polymer having a sulfonic acid group is even more preferably used as a binder for the coating layer. Alternatively, when the coating layer is provided on a layer containing a fluorine-containing polymer having a carboxylic acid group (carboxylic acid layer), a fluorine-containing polymer having a carboxylic acid group is more preferably used as a binder for the coating layer.

[0999] The content of the particles of inorganic material in the coating layer is preferably 40 to 90% by mass, more preferably 50 to 90% by mass. The content of the binder is preferably 10 to 60% by mass, more preferably 10 to 50% by mass.

[1000] The distribution density of the coating layer in the ion exchange membrane is preferably 0.05 to 2 mg per cm ² . When the ion exchange membrane has ridges (roughness) on its surface, the distribution density of the coating layer is preferably 0.5 to 2 mg per cm ² .

[1001] As a method for manufacturing the coating layer, which is not particularly limited, a known method can be applied. An example is a method comprising applying by spray or the like a coating liquid obtained by dispersing particles of an inorganic material in a solution containing a binder.

[1002] (Core Reinforcement Materials)

The ion exchange membrane preferably has core reinforcing materials disposed within the membrane body.

[1003] Reinforcing materials of the core are elements that increase the strength and dimensional stability of the ion exchange membrane. By placing the reinforcing materials of the core within the body of the membrane, it is possible, in particular, to control the expansion and contraction of the ion exchange membrane in the desired range. Such an ion exchange membrane does not expand or contract more than necessary during electrolysis and the like, and can maintain excellent dimensional stability for a long time.

[1004] The configuration of the core reinforcing materials is not particularly limited, and, for example, the core reinforcing materials may be formed by woven yarns called reinforcing yarns. Reinforcing yarns herein refer to yarns that constitute the constituent core reinforcing materials, can provide the desired dimensional stability and mechanical strength to the ion exchange membrane, and can be stably present in the ion exchange membrane. By using core reinforcing materials obtained by weaving such reinforcing yarns, better dimensional stability and mechanical strength can be imparted to the ion exchange membrane.

[1005] The material of the reinforcing materials of the core and the reinforcing yarns used therefor is not particularly limited, but is preferably a material resistant to acids, alkalis, etc., and a fiber including a fluorine-containing polymer is preferable since long-term heat resistance and chemical resistance are required. ...

[1006] Examples of the fluoropolymer used in the reinforcing materials of the core include polytetrafluoroethylene (PTFE), copolymers of tetrafluoroethylene and perfluoroalkyl vinyl ether (PFA), copolymers of tetrafluoroethylene and ethylene (ETFE), copolymers of tetrafluoroethylene copolymers and copolymers of tetrafluoroethylene copolymers and copolymers of tetrafluoroethylene copolymers PVDF). Among them, fibers including polytetrafluoroethylene are preferably used in terms of heat resistance and chemical resistance.

[1007] The diameter of the reinforcing yarns used for the core reinforcing materials is not particularly limited, but is preferably 20 to 300 denier, more preferably 50 to 250 denier. The weave density (web density per unit length) is preferably 5 to 50 / inch. The shape of the core reinforcing materials is not particularly limited, for example, woven fabric, non-woven fabric and knitted fabric are used, but preferably in the form of woven fabric. The thickness of the woven fabric used is preferably 30 to 250 µm, more preferably 30 to 150 µm.

[1008] As the woven fabric or knitted fabric, monofilaments, multifilaments or yarns thereof, twisted yarns with dangling yarns or the like can be used, and various types of weaving methods can be used such as plain weaving, leno weaving, knitted weaving, cord weave and crinkled chintz (seersucker).

[1009] The braiding and placement of the core reinforcing materials in the membrane body are not particularly limited, and the preferred placement can be appropriately provided in consideration of the size and shape of the ion exchange membrane, physical properties desired for the ion exchange membrane, environmental conditions in use, and the like.

[1010] For example, the core reinforcing materials may be placed along a predetermined direction of the membrane body, but from a dimensional stability point of view, it is preferable that the core reinforcing materials are placed along the predetermined first direction and other core reinforcing materials are placed along the predetermined second direction along essentially perpendicular to the first direction. By placing multiple core reinforcement materials substantially orthogonal within the membrane body, better dimensional stability and mechanical strength in many directions can be imparted. For example, a configuration is preferable in which core reinforcing materials disposed along the longitudinal direction (warp yarns) and core reinforcing materials disposed along the transverse direction (weft yarns) are woven on the surface side of the membrane body. A more preferred configuration is a plain weave, made and woven by allowing the warp yarn and the weft yarn to pass alternately above and below each other, a leno weave in which the two warp strands are woven into the twist weft strands, a matting weave, made and woven by inserting the same number of weft yarns into two or more parallel warp yarns, or the like, from the standpoint of dimensional stability, mechanical strength and ease of manufacture.

[1011] It is particularly preferable that the core reinforcing materials are disposed along both directions MD (longitudinal direction) and TD (transverse direction) of the ion exchange membrane. In other words, the core reinforcing materials are preferably plain weave in MD and TD. Here, MD means the direction in which the membrane body and various core materials (for example, reinforcing core materials, reinforcing yarns and consumable yarns described later) move in the later described stage of obtaining the ion exchange membrane (flow direction), and TD means a direction substantially perpendicular to MD ... The yarns weaved along the MD are called MD yarns, and the yarns weaved along the TD are called TD yarns. Typically, the ion exchange membrane used for electrolysis is rectangular, and in many cases, the longitudinal direction is MD and the width direction is TD. By weaving reinforcing core materials that are MD yarns and reinforcing core materials that are TD yarns, better dimensional stability and mechanical strength can be achieved in many directions.

[1012] The placement range of the core reinforcing materials is not particularly limited, and the preferred placement can be appropriately provided in consideration of the physical properties desired for the ion exchange membrane, the environmental conditions in use, and the like.

[1013] The opening ratio of the core reinforcing materials is not particularly limited, but is preferably 30% or more, more preferably 50% or more and 90% or less. The opening ratio is preferably 30% or more in terms of the electrochemical characteristics of the ion exchange membrane, and preferably 90% or less in terms of the mechanical strength of the ion exchange membrane.

[1014] The opening ratio of the reinforcing materials of the core herein refers to the ratio (B / A) of the total surface area (B) through which substances such as ions (electrolyte solution and the cations (eg sodium ions) contained therein) can pass to area (A) of any one surface of the body of the ion-exchange membrane. The total surface area (B) through which substances such as ions can pass may refer to the total areas of regions in which cations, electrolyte solution and the like are not retained in the ion exchange membrane by the reinforcing materials of the core and the like contained in the ion exchange membrane. membrane.

[1015] Figure 110 illustrates a schematic view for explaining the relative opening of the core reinforcing materials constituting the ion exchange membrane. Figure 110, in which a portion of the ion exchange membrane is shown enlarged, shows only the configuration of the reinforcing materials 21 and 22 of the core in these regions, without showing other elements.

[1016] By subtracting the total area (C) of the core reinforcing materials from the area of the area surrounded by the core reinforcing materials 21 located along the longitudinal direction and the core reinforcing materials 22 located along the transverse direction, the area including the area (A) of the core reinforcing materials can the total area (B) of the regions through which substances such as ions can pass in the area (A) of the above-described region can be obtained. That is, the relative aperture can be determined by the following formula (I):

Relative aperture = (B) / (A) = ((A) - (C)) / (A) (I)

[1017] Among the reinforcing materials of the core, a film textile thread or highly oriented monofilaments including PTFE are particularly preferred in terms of chemical resistance and heat resistance. More specifically, more preferred are plain weave core reinforcing materials that use 50 to 300 denier film textile yarns made by cutting a PTFE-containing high tenacity porous sheet into ribbon-shaped pieces, or comprising highly oriented PTFE monofilaments of 50 to 300 denier sizes. 300 denier, and which have a weave density of 10 to 50 threads or monofilaments per inch and have a thickness in the range of 50 to 100 microns. The opening ratio of the ion exchange membrane including such core reinforcing materials is more preferably 60% or more.

[1018] Examples of the shape of the reinforcing yarns include round yarns and film threads.

[1019] (Through Holes)

The ion exchange membrane preferably has through holes within the membrane body.

[1020] Through holes refer to holes that can form channels for ions generated during electrolysis and for an electrolyte solution. Through holes, which are tubular holes formed within the membrane body, are formed by dissolving the core consumables (or yarns) described below. The shape, diameter, or the like of the through holes can be controlled by selecting the shape or diameter of the core consumables (yarn consumables).

[1021] The formation of through holes within the ion exchange membrane can provide mobility of the electrolyte solution during electrolysis. The shape of the through holes is not particularly limited, but may be the shape of the core consumable materials used to form the through holes according to the production method described below.

[1022] The through holes are preferably formed to alternately pass on the anode side (sulfonic acid layer side) and cathode side (carboxylic acid layer side) of the core reinforcing materials. With this arrangement, in the region in which the through holes are formed on the cathode side of the core reinforcing materials, ions (eg sodium ions) supplied by the electrolyte solution filling the through holes can also flow to the cathode side of the core reinforcing materials. As a result, the flow of cations is not interrupted, and thus an additional reduction in the electrical resistance of the ion-exchange membrane is possible.

[1023] The through holes may be formed along only one predetermined direction of the membrane body constituting the ion exchange membrane, but are preferably formed along both the longitudinal direction and the transverse direction of the membrane body in view of exhibiting more stable electrolysis characteristics.

[1024] [Manufacturing Method]

A suitable example of a method for manufacturing an ion exchange membrane includes a method comprising the following steps (1) to (6):

Step (1): a step of producing a fluorine-containing polymer having an ion exchange group or an ion exchange group precursor capable of forming an ion exchange group by hydrolysis,

Step (2): a step of weaving at least a plurality of core reinforcing materials, if necessary, and consumable yarns that dissolve in acid or alkali and form through holes, to obtain a reinforcing material in which the consumable yarns are interposed between the core reinforcing materials, being adjacent to each other,

Step (3): a step of converting into a film the above fluorine-containing polymer having an ion exchange group or an ion exchange group precursor capable of forming an ion exchange group by hydrolysis,

Step (4): the step of introducing the above reinforcing materials, if necessary, into the above film to obtain a membrane body, inside which the reinforcing materials are placed,

Stage (5): stage of hydrolysis of the membrane body obtained in stage (4) (stage of hydrolysis) and

Step (6): The step of creating a coating layer on the membrane body obtained in step (5) (application step).

[1025] Next, each of the steps will be described in detail.

[1026] Step (1): the step of obtaining a fluoropolymer

In step (1), the monomeric starting materials described above in groups one to three are used to prepare the fluoropolymer. To regulate the ion-exchange capacity of the fluorine-containing polymer, the composition of the mixture of the starting monomer materials must be controlled during the production of the fluorine-containing polymer forming the said layers.

[1027] Stage (2): the stage of obtaining reinforcement materials

The reinforcing material is a woven fabric obtained by weaving reinforcing yarns or the like. The reinforcing material is embedded in the membrane to thereby form core reinforcing materials. When an ion-exchange membrane with through holes is formed, consumable yarns are additionally woven into the reinforcing material. The amount of consumable yarns contained in this case is preferably 10 to 80% by mass, more preferably 30 to 70% by mass, based on the total reinforcing material. The weaving of the consumable yarns can also prevent slippage of the yarns of the core reinforcing materials.

[1028] Viscose, polyethylene terephthalate (PET), cellulose, polyamide and the like are used as the consumable yarns that are dissolved in the membrane production step or in the electrolysis environment. Also preferred are monofilaments or multifilaments having a thickness of 20 to 50 denier and including polyvinyl alcohol and the like.

[1029] In step (2), the aperture ratio, the placement of the through holes, and the like can be controlled by adjusting the placement of the core reinforcing materials and the yarns consumed.

[1030] Step (3): Film forming step

In step (3), the fluoropolymer obtained in step (1) is formed into a film using an extruder. The film may have a single layer configuration, a two layer configuration of a sulfonic acid layer and a carboxylic acid layer as mentioned above, or a multilayer configuration of three or more layers.

[1031] Examples of the film forming method include the following:

a method in which a fluorine-containing polymer having a carboxylic acid group and a fluorine-containing polymer having a sulfonic acid group are separately formed into films; and

a method in which a fluorine-containing polymer having a carboxylic acid group and a fluorine-containing polymer having a sulfonic acid group are coextruded to form a composite film.

[1032] The number of each tape can be more than one. Co-extrusion of different films is preferred because of their contribution to the increase in bond strength at the interface.

[1033] Step (4): the step of obtaining the membrane body

In step (4), the reinforcing material obtained in step (2) is embedded in the film obtained in step (3) to form a membrane body containing the reinforcing material.

[1034] Preferred examples of a method for forming a membrane body include (i) a method in which a fluorine-containing polymer having a precursor of a carboxylic acid group (e.g., a carboxylate functional group) (hereinafter referred to as a first layer) disposed on the cathode side and a fluorine-containing polymer having a precursor of a sulfonic acid group (for example, a sulfonyl fluoride functional group) (hereinafter, including this layer is called the second layer), is formed into a film by the method of coextrusion, and, if necessary, using a heat source and a vacuum source, a reinforcing material and a composite film from the second layer / the first layer is laminated in this order on a breathable heat-resistant release paper on a flat plate or drum having numerous pores on their surface, and combined at a temperature at which each polymer melts while at the same time evacuating air from under each of the layers by means of reduced pressure ; and (ii) a method in which, in addition to the composite film of the second layer / first layer, a fluorine-containing polymer having a precursor of a sulfonic acid group is separately preformed into a film (third layer), and optionally using a heat source and a source vacuum, the third layer film, the core reinforcing materials and the composite film from the second layer / first layer are laminated in this order on a breathable heat-resistant release paper on a flat plate or drum having multiple pores on their surface and combined at a temperature at which each polymer is melted while pumping air out from under each of the layers by means of reduced pressure.

[1035] Co-extrusion of the first and second layer here helps to increase the bond strength at the interface.

[1036] The method of combining under reduced pressure is characterized by making the third layer on the reinforcing material thicker than in the press-applied method. In addition, since the reinforcing material is fixed to the inner surface of the membrane body, the method provides sufficient retention of the mechanical strength of the ion exchange membrane.

[1037] Embodiments of the layering methods described herein are exemplary, and coextrusion can be performed after a preferred layering configuration (eg, a combination of layers) is appropriately selected in consideration of the desired membrane body layer configurations and physical properties, and the like.

[1038] In order to further improve the electrical characteristics of the ion exchange membrane, it is also possible to additionally place a fourth layer comprising a fluorine-containing polymer having both a precursor of a carboxylic acid group and a precursor of a sulfonic acid group between the first layer and the second layer, or the use of a fourth layer comprising a fluorine-containing polymer having both a precursor of a carboxylic acid group and a precursor of a sulfonic acid group instead of the second layer.

[1039] The method for forming the fourth layer may be a method in which a fluorine-containing polymer having a precursor of a carboxylic acid group and a fluorine-containing polymer having a precursor of a sulfonic acid group are separately prepared and then mixed, or it may be a method in which a monomer is copolymerized having a precursor of a carboxylic acid group; and a monomer having a sulfonic acid precursor.

[1040] When the fourth layer is used as a component of the ion exchange membrane, a coextruded film of the first layer and the fourth layer is formed, in addition, the third layer and the second layer are separately formed into films, and the laminating can be performed in the above manner. Alternatively, three layers of the first layer / fourth layer / second layer can be coextruded simultaneously to form a film.

[1041] In this case, the direction in which the extruded film flows out is MD. As mentioned above, it is possible to form a membrane body containing a fluorine-containing polymer having an ion exchange group on the reinforcing material.

[1042] In addition, the ion exchange membrane preferably has protrusions constituted by a fluoropolymer having a sulfonic acid group, that is, protrusions on the side of the surface constituted by the sulfonic acid layer. As a method for forming such protrusions, which is not particularly limited, a known method including forming protrusions on a resin surface can also be applied. A specific example of the method is a method for embossing the surface of a membrane body. For example, the aforementioned protrusions can be formed using the pre-embossed release paper when the above composite film, reinforcing material, and the like are combined. In the case where the protrusions are formed by embossing, the height and density of the protrusions can be controlled by the shape of the transferred relief (the shape of the release paper).

[1043] (5) Hydrolysis step

At step (5), the stage of hydrolysis of the membrane body obtained at stage (4) is performed to convert the precursor of the ion-exchange group into an ion-exchange group (stage of hydrolysis).

[1044] In step (5), it is also possible to dissolve holes in the membrane body by dissolving and removing consumable yarns introduced into the membrane body by the action of an acid or alkali. The consumable yarns can remain in the through holes without being completely dissolved and removed. The consumable yarns remaining in the through holes can be dissolved and removed by the electrolyte solution when the ion exchange membrane is subjected to electrolysis.

[1045] The consumable yarn is dissolved in acid or alkali during the ion exchange membrane preparation step or in the electrolysis environment. The consumable yarns are washed out, thereby forming the through-holes at the appropriate locations.

[1046] Step (5) may be performed by immersing the membrane body obtained in step (4) in a hydrolysis solution containing an acid or alkali. An example of a hydrolysis solution that can be used is a mixed solution containing KOH and dimethyl sulfoxide (DMSO).

[1047] The mixed solution preferably contains KOH at normal concentration from 2.5 to 4.0 and DMSO from 25 to 35% by weight.

[1048] The temperature in the hydrolysis is preferably 70 to 100 ° C. The higher the temperature, the greater the apparent thickness can be. The temperature is more preferably 75 to 100 ° C.

[1049] The duration of the hydrolysis is preferably 10 to 120 minutes. The longer the hydrolysis takes, the greater the apparent thickness can be. The duration of the hydrolysis is preferably 20 to 120 minutes.

[1050] The step of forming the vias by washing out the sacrificial yarns will now be described in more detail. Figures 111 (a) and (b) are schematic views for explaining a method of forming vias in an ion exchange membrane.

[1051] Figures 111 (a) and (b) show reinforcing yarns 52, sacrificial yarns 504a, and through holes 504 formed only by sacrificial yarns 504a, without illustrating other features such as a membrane body.

[1052] First, the reinforcing yarns 52, which are to constitute the core reinforcing materials in the ion exchange membrane, and the consumable yarns 504a for forming the through holes 504 in the ion exchange membrane are used as interlaced reinforcing materials. Then, in step (5), the consumable yarns 504a are washed out to form the through holes 504.

[1053] The above method is simple because the method of interlacing reinforcing yarns 52 and consumable yarns 504a can be adjusted depending on the order of placement of the reinforcing materials of the core and through holes in the body of the ion exchange membrane.

[1054] Figure 111 (a) illustrates an example of a plain weave reinforcing material in which the reinforcing yarns 52 and the sacrificial yarns 504a are interlaced in both the longitudinal direction and the transverse direction in the paper, and optionally the order of placement of the reinforcing yarns 52 and the sacrificial yarn 504a in the reinforcing material can be changed.

[1055] (6) Application Phase

In step (6), a coating layer can be formed by preparing a coating liquid containing particles of inorganic material obtained by grinding raw ore or melting raw ore and a binder, applying a coating liquid to the surface of the ion exchange membrane obtained in step (5), and drying the coating liquids.

[1056] A preferred binder is a binder obtained by hydrolysis of a fluorine-containing polymer having an ion exchange group precursor with an aqueous solution containing dimethyl sulfoxide (DMSO) and potassium hydroxide (KOH), and then immersing the polymer in hydrochloric acid to replace the counter ion of the ion exchange group with H ⁺ ( for example, a fluorine-containing polymer having a carboxyl group or a sulfo group). Thus, the polymer is more likely to dissolve in water or ethanol, as mentioned below, which is preferred.

[1057] This binder is dissolved in a mixed solution of water and ethanol. The volume ratio between water and ethanol is preferably 10: 1 to 1:10, more preferably 5: 1 to 1: 5, even more preferably 2: 1 to 1: 2. The particles of inorganic material are dispersed in the dissolving liquid by means of a ball mill, thereby forming a coating liquid. In this case, it is also possible to correct the average particle size and the like of particles by adjusting the duration and speed of rotation during dispersion. The preferred amount of the mixed particles of inorganic material and binder is as mentioned above.

[1058] The concentration of the inorganic material particles and binder in the coating liquid is not particularly limited, but a free-flowing coating liquid is preferable. This makes it possible to uniformly apply the ion exchange membrane to the surface.

[1059] In addition, a surfactant may be added to the dispersion when particles of inorganic material are dispersed. As the surfactant, nonionic surfactants are preferred and examples include HS-210, NS-210, P-210 and E-212 from NOF CORPORATION.

[1060] The obtained coating liquid is applied to the surface of the ion exchange membrane by a spray application or roller coating, thereby forming an ion exchange membrane.

[1061] [Microporous Membrane]

The microporous membrane of the present embodiment is not particularly limited as long as the membrane can be formed to form an electrode laminated article for electrolysis as mentioned above. A variety of microporous membranes can be used.

The porosity of the microporous membrane of the present embodiment is not particularly limited, but may be, for example, 20 to 90, and preferably 30 to 85. The above porosity can be calculated by the following formula:

Porosity = (1– (dry weight of the membrane) / (weight calculated from the volume, calculated from the values of the thickness, width and length of the membrane, and the density of the membrane material)) × 100

The average pore size in the microporous membrane of the present embodiment is not particularly limited and may be, for example, 0.01 µm to 10 µm, preferably 0.05 µm to 5 µm. With regard to the average pore size, for example, the membrane is cut vertically in the direction of thickness, and the cross section is examined by field emission scanning electron microscopy (FE-SEM). The average pore size can be obtained by measuring the diameter of about 100 pores and averaging the results.

The thickness of the microporous membrane of the present embodiment is not particularly limited and may be, for example, 10 µm to 1000 µm, preferably 50 µm to 600 µm. The above thickness can be measured using, for example, a micrometer (manufactured by Mitutoyo Corporation) or the like.

Specific examples of a microporous membrane as above include Zirfon Perl UTP 500 manufactured by Agfa (also referred to as a Zirfon membrane in this embodiment) and are described in International Publication No. WO 2013-183584 and International Publication No. WO 2016-203701.

[1062] In the present embodiment, the membrane preferably comprises a first ion exchange resin layer and a second ion exchange resin layer having an EW (ion exchange capacity) value different from the EW of the first ion exchange resin layer. In addition, the membrane preferably contains a first ion exchange resin layer and a second ion exchange resin layer having a different functional group than the functional group in the first ion exchange resin layer. The ion exchange capacity can be adjusted by the introduced functional group, and the functional groups that can be introduced are as mentioned above.

[1063] (Water electrolysis)

The electrolyzer in the present embodiment as an electrolysis cell in the case of water electrolysis has a configuration in which an ion exchange membrane in the electrolysis cell for use in the case of the above conventional salt electrolysis is replaced with a microporous membrane. The supplied raw material, which is water, is different from the material for the electrolytic cell in the case of the above-mentioned conventional salt electrolysis. As for other components, parts similar to those of the electrolysis cell in the case of conventional salt electrolysis can also be used in a water electrolysis cell. Since chlorine gas is generated in the anode chamber in conventional salt electrolysis, titanium is used as the anode chamber material, but in the case of water electrolysis, only oxygen gas is emitted in the anode chamber. Thus, a material identical to that of the cathode chamber can be used. Nickel is one example of this. A catalytic coating for generating oxygen is suitable for coating the anode. Examples of the catalytic coating include metals, oxides and hydroxides of platinum group metals and metals from the transition metal group. For example, elements such as platinum, iridium, palladium, ruthenium, nickel, cobalt, and iron can be used.

[1064] <Seventh embodiment>

Here, a seventh embodiment of the present invention will be described in detail with reference to Figures 112-122.

[1065] [Method of manufacturing an electrolytic cell]

A method for manufacturing an electrolyzer according to a first aspect (hereinafter referred to simply as "first aspect") of a seventh embodiment (hereinafter in the section <Seventh Embodiment>, simply referred to as a "present embodiment") is a method of forming a new electrolyzer by placing a laminated article including an electrolysis electrode and a new membrane, in an existing electrolysis cell including an anode, a cathode that is opposite the anode, a membrane that is secured between the anode and cathode, and an electrolyzer frame that supports the anode, cathode and membrane, the method comprising the step (A) of releasing the membrane from the fixed conditions in the cell frame, and step (B) replacing the membrane with a laminated article after step (A).

As described above, according to the method for manufacturing an electrolytic cell according to the first aspect, it is possible to renew the electrode without removing each component to the outside of the cell frame, and the efficiency during the refurbishment of the electrode in the cell can be improved.

A method for manufacturing an electrolysis cell according to a second aspect (hereinafter referred to simply as the “first aspect”) of the present embodiment is a method of forming a new electrolysis cell by placing an electrode for electrolysis in an existing electrolysis cell including an anode, a cathode and a membrane that is fixed between the anode and cathode and an electrolyzer frame which supports the anode, cathode and membrane, the method comprising the step (A) of releasing the membrane from a fixed state in the cell frame, and the step (B ') of placing an electrode for electrolysis between the membrane and the anode or cathode after step (A).

As described above, also in accordance with the method for manufacturing an electrolytic cell according to the second aspect, it is possible to renew the electrode without removing each component to the outside of the cell frame, and it is possible to improve the working efficiency during the renewal of the electrode in the cell.

Hereinafter, when reference is made to "a method for manufacturing an electrolytic cell according to the present embodiment," the method for manufacturing an electrolytic cell according to the first aspect and a method for manufacturing an electrolytic cell according to the second aspect are meant.

[1066] In the method for manufacturing an electrolytic cell of the present embodiment, an existing electrolyzer includes an anode, a cathode that is opposite the anode, a membrane that is disposed between the anode and cathode, and an electrolyzer frame that supports the anode, cathode, and membrane as structural members. In other words, the existing electrolyzer contains an electrolytic cell. The existing electrolytic cell is not particularly limited as long as it contains the above-described structural elements, and various known configurations can be applied.

[1067] In the method for manufacturing an electrolysis cell of the present embodiment, the new electrolysis cell further comprises an electrolysis electrode or a laminated article, in addition to an element that has already served as an anode or cathode in the existing electrolysis cell. That is, in the first aspect and the second aspect, the "electrolysis electrode" disposed when forming a new electrolysis cell serves as an anode or cathode, and is separate from the cathode and anode in the existing electrolysis cell. In the method for manufacturing an electrolysis cell of the present embodiment, even in a case where the efficiency of the anode and / or cathode in electrolysis has deteriorated due to the operation of the existing electrolysis cell, placing the electrolysis electrode separately from them allows the anode and / or cathode to be refurbished. In the first aspect, in which the laminated article is used, a new ion exchange membrane is placed in combination with it, and thus the performance of the ion exchange membrane which has deteriorated due to operation can be simultaneously updated. As referred to herein, "performance upgrade" means achieving performance that is comparable to the original performance that the existing cell had before operation, or performance that exceeds the original performance.

[1068] In the method for manufacturing an electrolytic cell of the present embodiment, an existing electrolytic cell is considered “an electrolyzer that was already in operation”, and a new electrolysis cell is considered a “electrolyzer that has not yet been operated”. That is, once the cell formed as a new cell starts to be used, the cell becomes the “existing cell in the present embodiment”. Placing an electrolysis electrode or laminated article in this existing electrolysis cell creates a “new electrolysis cell of the present embodiment”.

[1069] Next, a case of performing conventional salt electrolysis using an ion exchange membrane as an exemplary membrane and one embodiment of an electrolyser will be described in detail. In the section <Seventh Embodiment>, unless otherwise stated, “electrolytic cell in the present embodiment” includes both “an existing electrolytic cell in the present embodiment” and “a new electrolytic cell of the present embodiment”.

[1070] [Electrolytic Cell]

First, an electrolytic cell that can be used as a structural member of an electrolytic cell in the present embodiment will be described. Figure 112 illustrates a cross-sectional view of an electrolytic cell 1.

The electrolytic cell 1 contains an anode chamber 10, a cathode chamber 20, a dividing wall 30 located between the anode chamber 10 and the cathode chamber 20, an anode 11 located in the anode chamber 10, and a cathode 21 located in the cathode chamber 20. If necessary, an electrolytic cell 1 has a substrate 18a and a reverse current absorbing layer 18b formed on the substrate 18a, and may include a reverse current absorber 18 disposed in the cathode chamber. The anode 11 and the cathode 21, which are part of the electrolytic cell 1, are electrically connected to each other. In other words, the electrolytic cell 1 contains the following cathode structure. The cathode structure 40 comprises a cathode chamber 20, a cathode 21 disposed in the cathode chamber 20, and a reverse current absorber 18 disposed in the cathode chamber 20, the reverse current absorber 18 having a substrate 18a and a reverse current absorbing layer 18b formed on the substrate 18a as shown in Figure 116, and the cathode 21 and the reverse current absorbing layer 18b are electrically connected. In addition, the cathode chamber 20 has a current collector 23, a holder 24 supporting the current collector, and a metal elastic body 22. The metal elastic body 22 is placed between the current collector 23 and the cathode 21. The holder 24 is located between the current collector 23 and the partition 30. The current collector 23 is electrically connected to cathode 21 through the metal elastic body 22. The separating partition 30 is electrically connected to the current collector 23 through the holder 24. Accordingly, the separating partition 30, the holder 24, the current collector 23, the metal elastic body 22 and the cathode 21 are electrically connected to each other. The cathode 21 and the reverse current absorbing layer 18b are electrically connected. The cathode 21 and the reverse current absorbing layer 18b may be connected directly, or may be connected indirectly through a down conductor, a holder, a metal resilient body, a baffle, or the like. The entire surface of the cathode 21 is preferably coated with a catalyst layer for the reduction reaction. The form of the electrical connection may be a form in which the baffle 30 and the support 24, the support 24 and the collector 23 and the collector 23 and the metal resilient body 22 are in each case directly connected to each other, and the cathode 21 is laminated on the metal resilient body 22. Examples methods for directly attaching these structural elements to each other include welding and the like. Alternatively, the reverse current absorber 18, cathode 21, and current collector 23 may be collectively referred to as cathode structure 40.

[1071] Figure 113 illustrates a cross-sectional view of two electrolytic cells 1 that are adjacent in electrolytic cell 4. Figure 114 shows electrolytic cell 4. Figure 115 shows an assembly step for electrolytic cell 4 (other than steps (A) - (B) and steps (A ') -(IN').

[1072] As shown in Figure 113, the electrolytic cell 1, the cation exchange membrane 2, and the electrolytic cell 1 are arranged in series in this order. The ion exchange membrane 2 is placed between the anode chamber of one electrolytic cell 1 of two electrolytic cells that are adjacent in the electrolyzer and the cathode chamber of another electrolytic cell 1. That is, the anode chamber 10 of the electrolytic cell 1 and the cathode chamber 20 of the adjacent electrolytic cell 1 are separated by a cation exchange membrane 2. As shown in Figure 114, electrolytic cell 4 is formed such that a plurality of electrolytic cells 1 connected in series through an ion exchange membrane 2 are supported by an electrolytic cell frame 8. That is, the cell 4 is a bipolar cell including a plurality of electrolytic cells 1 in series and ion exchange membranes 2, in each case positioned between adjacent electrolytic cells 1, and an cell frame 8 that supports cells 1 and membranes 2. As shown in Figure 115, the electrolytic cell 4 is assembled by placing a plurality of electrolytic cells 1 in series connection through the ion exchange membrane 2 and binding the cells by means of a clamping device 5 in the frame 8 of the cell. The cell frame is not particularly limited as long as it is capable of supporting each cell as well as linking the cells, and a variety of known configurations can be used. The device for bonding each of the membranes contained in the cell frame is not particularly limited, and examples thereof include hydraulic presses and devices including a pull rod as a drive.

[1073] Electrolyzer 4 has an anode lead 7 and a cathode lead 6 that are connected to a power supply. An anode 11 of an electrolytic cell 1 located at the farthest end of a plurality of electrolytic cells 1 connected in series in an electrolysis cell 4 is electrically connected to an anode terminal 7. A cathode 21 of an electrolytic cell located at an end opposite to the anode terminal 7 among the plurality of electrolytic cells 1, connected in series in the electrolytic cell 4, electrically connected to the cathode terminal 6. Electric current during electrolysis flows from the side of the anode terminal 7 through the anode and the cathode of each electrolytic cell 1 towards the cathode terminal 6. At both ends of the connected electrolytic cells 1 there may be an electrolytic cell, having only an anode chamber (anode outlet cell), and an electrolytic cell having only a cathode chamber (cathode outlet cell). In this case, the anode terminal 7 is connected to an anode terminal cell located at one end, and the cathode terminal 6 is connected to a cathode terminal cell located at the other end.

[1074] In the case of brine electrolysis, brine is supplied to each anode chamber 10, and pure water or low-concentration aqueous sodium hydroxide solution is supplied to each cathode chamber 20. Each liquid is supplied from an electrolyte solution supply pipe (not shown) through a hose for supplying an electrolyte solution (not shown in the figure) to each electrolytic cell 1. The electrolyte solution and electrolysis products are removed from the pipe for removing the electrolyte solution (not shown in the figure). During electrolysis, sodium ions in the brine migrate from the anode chamber 10 of one electrolytic cell 1 through the ion exchange membrane 2 to the cathode chamber 20 of the adjacent electrolytic cell 1. Thus, the electric current during electrolysis flows in the direction in which the electrolytic cells 1 are connected in series. That is, an electric current flows through the cation exchange membrane 2 from the anode chamber 10 towards the cathode chamber 20. When the brine is electrolyzed, chlorine gas is generated on the anode 11 side, and sodium hydroxide (dissolved) and hydrogen gas are generated on the cathode 21 side.

[1075] (Anode chamber)

The anode chamber 10 has an anode 11 or an anode supply conductor 11. Here, under the supply conductor is meant a worn electrode (ie, an existing electrode), an electrode not having a catalytic coating, and the like. When the electrolysis electrode in the present embodiment is inserted on the anode side, 11 serves as an anode supply conductor. When the electrolysis electrode of the present embodiment is not inserted on the anode side, 11 serves as an anode. The anode chamber 10 preferably has an anode-side electrolyte solution supply unit that supplies electrolyte solution to the anode chamber 10, a baffle plate that is positioned above the anode-side electrolyte solution supply unit so as to be substantially parallel or inclined with respect to the baffle 30, and a gas an anode-side liquid separator located above the baffle plate for separating gas from an electrolyte solution including an admixed gas.

[1076] (Anode)

When the electrode for electrolysis in the present embodiment is not inserted on the anode side, the anode 11 is in the frame of the anode chamber 10 (i.e., in the anode frame). As the anode 11, a metal electrode such as a so-called DSA (R) can be used. DSA is an electrode including a titanium substrate, the surface of which is coated with an oxide including ruthenium, iridium and titanium as components.

As for the shape, any of a perforated metal sheet, a nonwoven fabric, a porous metal, an expanded metal sheet, an electrospinning metal porous foil, a so-called woven metal mesh formed by interlacing of thin metal filaments, and the like can be used.

[1077] (Anode Supply Conductor)

When the electrode for electrolysis of the present embodiment is inserted on the anode side, an anode supply conductor 11 is provided on the frame of the anode chamber 10. A metal electrode such as a so-called DSA (R) can be used as the anode supply conductor 11, and can also be used titanium without catalytic coating. Alternatively, a DSA having a thinner catalytic coating can also be used. In addition, an already used anode can also be used.

As for the shape, any of a perforated metal sheet, a nonwoven fabric, a porous metal, an expanded metal sheet, an electrospinning metal porous foil, a so-called woven metal mesh formed by interlacing of thin metal filaments, and the like can be used.

[1078] (Anode side electrolyte solution supply unit)

An anode-side electrolyte solution supply unit that supplies an electrolyte solution to the anode chamber 10 is connected to a pipe for supplying an electrolyte solution. The anode side electrolyte solution supply unit is preferably disposed under the anode chamber 10. As the anode side electrolyte solution supply unit, for example, a pipe on the surface of which lumen portions (dispersion tube) and the like can be used. Such a tube is more preferably located along the surface of the anode 11 and parallel to the bottom 19 of the electrolytic cell. This pipe is connected to a pipe for supplying an electrolyte solution (a liquid supply pipe), which supplies an electrolyte solution to an electrolytic cell 1. The electrolyte solution supplied from a liquid supply pipe is passed through a pipe into an electrolytic cell 1 and is fed from the holes made on the pipe surface to the inside of the anode chambers 10. The placement of the pipe along the surface of the anode 11 and parallel to the bottom 19 of the electrolytic cell is preferable because the electrolyte solution can be uniformly supplied to the inside of the anode chamber 10.

[1079] (Anode side gas-liquid separator)

The anode-side gas-liquid separator is preferably located above the baffle plate. The purpose of the anode-side gas-liquid separator is to separate the generated gas, such as chlorine gas, from the electrolyte solution during electrolysis. Unless otherwise indicated, "above" means an upward direction in an electrolytic cell 1 in FIG. 112, and "under" means a downward direction in an electrolytic cell 1 in FIG. 112.

[1080] The gas generated during electrolysis, evolved in the electrolytic cell 1, and the electrolyte solution form a mixed phase (gas-liquid mixed phase), which is then discharged from the system. As a consequence, pressure fluctuations within the electrolytic cell 1 cause vibration, which can lead to physical damage to the ion exchange membrane. To prevent this phenomenon, the electrolytic cell 1 of the present embodiment is preferably equipped with an anode-side gas-liquid separator for separating gas from liquid. The anode-side gas-liquid separator is preferably provided with a defoamer plate to eliminate bubbles. When the gas-liquid mixed phase stream flows through the defoamer plate, the bubbles burst, thereby separating the electrolyte solution and gas. As a result, vibration during electrolysis can be prevented.

[1081] (Baffle Plate)

The baffle plate is preferably positioned above the anode side electrolyte solution supply unit and is positioned substantially parallel or obliquely with respect to the baffle 30. The baffle plate is a baffle plate that controls the flow of electrolyte solution into the anode chamber 10. When the baffle plate is provided, it can cause circulation electrolyte solution (brine or the like) inside the anode chamber 10, thereby making the concentration more uniform. To create internal circulation, the baffle plate is preferably positioned so as to separate the space near the anode 11 from the space near the baffle 30. For this reason, the baffle plate is preferably positioned so that it is opposite the surface of the anode 11 and the surface of the baffle 30. In the space near the anode separated by the baffle plate, electrolysis occurs, the concentration of the electrolyte solution (brine concentration) decreases, and a generated gas such as chlorine gas is released. This leads to a difference in the specific gravity of the gas-liquid mixture between the space near the anode 11 and the space near the dividing wall 30, separated by a baffle plate. Using this difference, it is possible to stimulate the internal circulation of the electrolyte solution in the anode chamber 10, thereby making the concentration distribution of the electrolyte solution in the anode chamber 10 more uniform.

[1082] Although not shown in Figure 112, a down conductor may also optionally be provided within the anode chamber 10. The material and configuration of such a current collector can be the same as for the aforementioned collector of the cathode chamber. In the anode chamber 10, the anode 11 itself can also serve as a down conductor.

[1083] (Divider)

The dividing wall 30 is disposed between the anode chamber 10 and the cathode chamber 20. The dividing wall 30 may be referred to as a separator, and the anode chamber 10 and the cathode chamber 20 are separated from each other by a dividing wall 30. As the dividing wall 30, a baffle known as a separator can be used. electrolysis, and an example thereof comprises a baffle formed by welding a nickel-containing plate on the cathode side and a titanium-containing plate on the anode side.

[1084] (Cathode Chamber)

In the cathode compartment 20, when the electrolysis electrode of the present embodiment is inserted on the cathode side, 21 serves as a cathode supply conductor. When the electrolysis electrode of the present embodiment is not inserted on the cathode side, 21 serves as the cathode. When a return current absorber is present, the cathode or cathode supply conductor 21 is electrically connected to the return current absorber. Cathode chamber 20, like anode chamber 10, preferably has a cathode-side electrolyte solution supply unit and a cathode-side gas-liquid separator. Among the components constituting the cathode compartment 20, components similar to those constituting the anode compartment 10 will not be described.

[1085] (Cathode)

When the electrode for electrolysis of the present embodiment is not inserted on the cathode side, the cathode 21 is in the frame of the cathode chamber 20 (i.e., in the cathode frame). Cathode 21 preferably has a nickel substrate and a catalyst layer that covers the nickel substrate. Examples of catalyst bed components include elements such as Ru, C, Si, P, S, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Rh, Pd , Ag, Cd, In, Sn, Ta, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho , Er, Tm, Yb and Lu, as well as oxides and hydroxides of these metals. Examples of the method for forming the catalyst layer include electrodeposition, alloy electrodeposition, dispersion / composite electrodeposition, CVD, FOPP, pyrolysis, and sputtering. These methods can be used in combination. The catalyst bed can have multiple layers and multiple elements as needed. The cathode 21 can be subjected to a reduction treatment, if necessary. Nickel, nickel alloys and nickel-plated iron or stainless steel can be used as the substrate for the cathode 21.

As for the shape, any of a perforated metal sheet, a nonwoven fabric, a porous metal, an expanded metal sheet, an electrospinning metal porous foil, a so-called woven metal mesh formed by interlacing of thin metal filaments, and the like can be used.

[1086] (Cathode Supply Conductor)

When the electrode for electrolysis of the present embodiment is inserted on the cathode side, a cathode supply conductor 21 is provided in the frame of the cathode chamber 20. The cathode supply conductor 21 may be coated with a catalyst component. The catalyst component can be a component that is initially used as a cathode and is stored. Examples of catalyst bed components include elements such as Ru, C, Si, P, S, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Rh, Pd , Ag, Cd, In, Sn, Ta, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho , Er, Tm, Yb and Lu, as well as oxides and hydroxides of these metals. Examples of the method for forming the catalyst layer include electrodeposition, alloy electrodeposition, dispersion / composite electrodeposition, CVD, FOPP, pyrolysis, and sputtering. These methods can be used in combination. The catalyst bed can have multiple layers and multiple elements as needed. Nickel, nickel alloys and nickel-plated iron or stainless steel without catalytic coating can be used. Nickel, nickel alloys and nickel-plated iron or stainless steel can be used as the substrate for the cathode supply conductor 21.

As for the shape, any of a perforated metal sheet, a nonwoven fabric, a porous metal, an expanded metal sheet, an electrospinning metal porous foil, a so-called woven metal mesh formed by interlacing of thin metal filaments, and the like can be used.

[1087] (Reverse Current Absorbing Layer)

As the material for the layer that absorbs the reverse current, a material that is less noble in terms of the redox potential than the redox potential of the element for the aforementioned catalyst layer of the cathode can be selected. Examples include nickel and iron.

[1088] (Down conductor)

The cathode chamber 20 preferably contains a current collector 23. The current collector 23 improves the efficiency of current extraction. In the present embodiment, the collector 23 is a porous plate and is preferably disposed substantially parallel to the surface of the cathode 21.

[1089] The collector 23 preferably contains an electrically conductive metal such as nickel, iron, copper, silver, and titanium. The current collector 23 can be a mixture, alloy or complex oxide of these metals. The collector 23 may be of any shape as long as the shape allows the collector to function and may be in the form of a plate or mesh.

[1090] (Metallic elastic body)

By placing the metal elastic body 22 between the current collector 23 and the cathode 21, each cathode 21 of a plurality of electrolytic cells 1 connected in series is pressed against the ion exchange membrane 2 to shorten the distance between each anode 11 and each cathode 21. Thus, it is possible to reduce the voltage applied to the entire plurality of electrolytic cells connected in series. cells 1. Reducing voltage helps to reduce power consumption. When the metal resilient body 22 is placed, the pressing pressure generated by the metal resilient body 22 allows the electrolysis electrode to stably maintain its position in place when the laminated article containing the electrolysis electrode in the present embodiment is placed in the electrolytic cell.

[1091] As the metal resilient body 22, spring members such as coil and coil springs and shock absorbing mats can be used. As the metal elastic body 22, an element can be appropriately applied in consideration of mechanical stress due to pressure on the ion exchange membrane and the like. The metal resilient body 22 may be located on the surface of the collector 23 on the side of the cathode chamber 20, or may be provided on the surface of the partition wall on the side of the anode chamber 10. The two chambers are usually separated so that the cathode chamber 20 becomes smaller than the anode chamber 10. Thus In terms of frame strength and the like, the metal resilient body 22 is preferably placed between the collector 34 and the cathode 21 in the cathode chamber 20. The metal resilient body 22 preferably contains an electrically conductive metal such as nickel, iron, copper, silver and titanium.

[1092] (Holder)

The cathode chamber 20 preferably comprises a holder 24 which electrically connects the collector 23 to the baffle 30. This can achieve an efficient current flow.

[1093] The holder 24 preferably contains an electrically conductive metal such as nickel, iron, copper, silver, and titanium. The holder 24 can be of any shape as long as the holder can support the collector 23 and can be in the form of a rod, plate, or mesh. The holder 24 is in the form of a plate, for example. A plurality of holders 24 are disposed between the baffle 30 and the down conductor 23. The plurality of holders 24 are aligned so that their surfaces are parallel to each other. The holders 24 are located substantially perpendicular to the baffle 30 and the down conductor 23.

[1094] (Anode side seal and cathode side seal)

The anode side seal is preferably located on the surface of the frame constituting the anode chamber 10. The cathode side seal is preferably positioned on the surface of the frame constituting the cathode compartment 20. The electrolytic cells are interconnected such that the anode side seal in one electrolytic cell and the cathode side seal an ion exchange membrane 2 is laid on an adjacent electrolytic cell (see Figure 113). These seals can create airtightness at the junctions when a plurality of electrolytic cells 1 are connected in series through an ion exchange membrane 2.

[1095] The seals form a seal between the ion exchange membrane and the electrolytic cells. Specific examples of seals include picture frame-like rubber sheets in the center of which an opening is formed. The seals must be resistant to corrosive electrolyte solutions or generated gas and be functional for a long period of time. Thus, with regard to chemical resistance and hardness, vulcanized products and peroxide-crosslinked products of ethylene-propylene-diene rubber (EPDM-rubber) and ethylene-propylene rubber (EPM-rubber) are usually used as seals. Alternatively, if necessary, seals can be used in which the area in contact with the liquid (the area in contact with the liquid) is coated with a fluorine resin such as polytetrafluoroethylene (PTFE) and copolymers of tetrafluoroethylene and perfluoroalkyl vinyl ethers (PFA). These seals may in each case have an opening that does not impede the flow of the electrolyte solution, and the shape of the opening is not particularly limited. For example, a seal in the form of a picture frame is attached by means of an adhesive or the like along the peripheral edge of each opening of the anode chamber frame constituting the anode compartment 10 or the cathode compartment frame constituting the cathode compartment 20. Then, for example, in the case where two electrolytic cells 1 are connected through ion exchange membrane 2 (see Figure 113), each electrolytic cell 1 to which a seal is attached must be sealed by means of an ion exchange membrane 2. This seal can prevent electrolyte solution, alkali metal hydroxide, chlorine gas, hydrogen gas from escaping from the electrolytic cells 1 and the like formed by electrolysis.

[1096] [Laminated Product]

In the method for manufacturing an electrolysis cell of the present embodiment, the electrolysis electrode can be used as a laminated article with a membrane such as an ion exchange membrane or a microporous membrane. That is, the laminated article in the present embodiment contains an electrode for electrolysis and a new membrane. The new membrane is not particularly limited as long as it is separate from the membrane in the existing cell, and a variety of known "membranes" can be used. The material, shape, physical properties, and the like of the new membrane may be similar to those of the existing electrolyzer. Specific examples of the electrolysis electrode and membrane will be described in detail below.

[1097] (Stage (A))

In step (A), in the first aspect, the membrane is released from the fixed state in the cell frame. “In the cell frame” means that step (A) is performed while the state is maintained in which the electrolytic cell (i.e., the cell containing the anode and the cathode) and membranes are supported by the cell frame, and the aspect in which the electrolytic cell is removed is eliminated from the cell frame. Examples of a method for releasing a membrane from a secured state include, but are not limited to, a method in which the action of the pressing device is weakened by creating a gap between the electrolytic cell and the membrane to make the membrane removable outwardly from the cell frame. In step (A), the release of the membrane from the fixed state in the cell frame is preferably performed by sliding the anode and cathode in the direction of their placement, respectively. This operation allows the membrane to be made outwardly removable from the cell frame without removing the electrolytic cell outwardly from the cell frame.

[1098] [Stage (B)]

In step (B) in a first aspect, the membrane in the existing electrolytic cell is replaced with a laminated body after step (A). Examples of the replacement method include, but are not limited to, a method in which a gap is created between an electrolytic cell and an ion exchange membrane, then an existing ion exchange membrane to be refurbished is removed, and then a laminated article is inserted into the gap. By this method, the laminated article can be placed on the anode or cathode surface of an existing cell and the characteristics of the ion exchange membrane and the anode and / or cathode can be restored.

After step (B), the laminate is preferably secured to the cell frame by compression with the anode and cathode. More specifically, after the membrane has been replaced by a laminated body in an existing electrolytic cell, the laminated body and the elements in the existing electrolytic cell, such as an electrolytic cell, can be pressed together again with the pressing device. By this method, the laminated article can be fixed to the surface of the anode or cathode in an existing electrolysis cell.

[1099] A specific example of steps (A) - (B) in the first aspect will be described based on Figures 117 (A) and (B). First, the compressive force of the pressing device 5 is weakened, and the plurality of electrolytic cells 1 and ion exchange membranes 2 are shifted in the direction α of their placement. This allows a gap S to be formed between the electrolytic cell 1 and the ion exchange membrane 2 without removing the electrolytic cell 1 outwardly from the electrolytic cell frame 8, and the ion exchange membrane 2 being removed outwardly from the cell frame 8. Subsequently, the replaceable ion exchange membrane 2 of the existing cell is removed from the cell frame 8, and a laminated article 9 of the new ion exchange membrane 2a and the electrolysis electrode 100 is inserted in its place between adjacent electrolytic cells 1 (i.e., in the gap S). Thereby, the laminated article 9 is placed between adjacent electrolytic cells 1, and these components become supported by the frame 8 of the electrolytic cell. Then, the plurality of electrolytic cells 1 and the laminated product 9 are pressed together in the placement direction α using the pressing device 5.

[1100] (Stage (A '))

In step (A ') in the second aspect, the membrane is also released from the fixed state in the cell frame, as in the first aspect. In step (A '), the release of the membrane from the fixed state in the cell frame is also preferably carried out by shifting the anode and cathode in the direction of their placement, respectively. This operation allows the membrane to be made outwardly removable from the cell frame without removing the electrolytic cell outwardly from the cell frame.

[1101] [Stage (B ')]

In step (B ') in a second aspect, after step (A'), an electrode for electrolysis is placed between the membrane and the anode or cathode. Examples of a method for placing an electrode for electrolysis include, but are not limited to, a method in which, for example, a gap is provided between an electrolytic cell and an ion exchange membrane, and then the electrode for electrolysis is inserted into the gap. In this way, an electrolysis electrode can be placed on the surface of an anode or cathode in an existing electrolyzer, and the characteristics of the anode or cathode can be restored.

After step (B '), the electrolysis electrode is preferably fixed in the cell frame by pressing with the anode and cathode. More specifically, after the electrolysis electrode has been placed on the surface of the anode or cathode in the existing electrolysis cell, the electrolysis electrode and the elements in the existing electrolysis cell, such as an electrolytic cell, can be pressed together again with the pressing device. By this method, the laminated article can be fixed to the surface of the anode or cathode in an existing electrolysis cell.

[1102] A specific example of steps (A ') - (B') in the second aspect will be described based on Figures 118 (A) and (B). First, the compressive force of the pressing device 5 is weakened, and the plurality of electrolytic cells 1 and ion exchange membranes 2 are shifted in the direction α of their placement. This makes it possible to form a gap S between the electrolytic cell 1 and the ion exchange membrane 2 without removing the electrolytic cell 1 out of the cell frame 8. Then, an electrode 100 for electrolysis is inserted between adjacent electrolytic cells 1 (i.e., in the gap S). Thereby, the electrolysis electrode 100 is positioned between adjacent electrolytic cells 1, and these components become supported by the electrolytic cell frame 8. Then, the plurality of electrolytic cells 1 and the electrolysis electrode 100 are pressed together in the placement direction α with the pressing device 5.

[1103] In step (B) in the first aspect, the laminated article is preferably fixed to the surface of at least one of the anode and the cathode at a temperature at which the laminated article does not melt.

The “temperature at which the laminated article does not melt” can be identified as the softening point of the new membrane. The temperature may vary depending on the material constituting the membrane, but preferably ranges from 0 to 100 ° C, more preferably from 5 to 80 ° C, even more preferably from 10 to 50 ° C.

The above-described fixing is preferably performed at normal pressure.

In addition, the laminated article is preferably obtained by combining an electrolysis electrode and a new membrane at a temperature at which the membrane does not melt, and then used in step (B).

[1104] As a specific example of the above combination, which is not specifically limited, all types of methods can be used except for typical membrane melting methods such as thermocompression. One preferred example is a method in which a liquid is interposed between the below-mentioned electrolysis electrode and the membrane, and the surface tension of the liquid is used to combine the electrode and the membrane.

[1105] [Electrolysis Electrode]

In the method for manufacturing an electrolysis cell of the present embodiment, the electrode for electrolysis is not particularly limited as long as the electrode can be used for electrolysis. The electrolysis electrode can be an electrode that serves as a cathode in electrolysis, or it can be an electrode that serves as an anode. As for the material, shape and the like of the electrolysis electrode, suitable ones can be appropriately selected in consideration of the configuration of the electrolytic cell and the like. Preferred aspects of the electrode for electrolysis in the present embodiment will be described below, but they are only exemplary aspects preferred for a situation in which the electrode is combined with a new membrane to form a laminated article in the first aspect. Electrolysis electrodes other than the following aspects can be appropriately used.

[1106] The electrode for electrolysis in the present embodiment has a force applied per unit mass · unit area, preferably 1.6 N / (mg · cm ² ) or less, more preferably less than 1.6 N / (mg · cm ² ) , further preferably less than 1.5 N / (mg cm ² ), even more preferably 1.2 N / (mg cm ² ) or less, even more preferably 1.20 N / (mg cm) ² or less with from the point of view of providing good workability and good adhesion to a membrane such as an ion exchange membrane and a microporous membrane, with a supply conductor (a worn electrode and an electrode not having a catalytic coating) and the like. The applied force is even more preferably 1.1 N / (mg cm ² ) or less, further more preferably 1.10 N / (mg cm ² ) or less, even more preferably 1.0 N / (mg cm ²⁾ ) or less, even more preferably 1.00 N / (mg · cm ² ) or less.

From the viewpoint of further improving the electrolysis productivity, the force is preferably more than 0.005 N / (mg cm ² ), more preferably 0.08 N / (mg cm ² ) or more, further preferably 0.1 N / (mg cm ² ) or more, even more preferably 0.14 N / (mg · cm ² ) or more. Even more preferably, the force is 0.2 N / (mg · cm ² ) or more from the viewpoint of further facilitating the handling of a large size (eg, 1.5 mx 2.5 m).

The above-described applied force may be within the above-described range by appropriately adjusting, for example, the below-described open porosity ratio, electrode thickness, arithmetic mean of surface roughness, and the like. For example, more specifically, a higher open porosity ratio results in a lower applied force, and a lower open porosity ratio results in a higher applied force.

The mass per unit area is preferably 48 mg / cm ² or less, more preferably 30 mg / cm ² or less, even more preferably 20 mg / cm ² or less from the standpoint of providing good processability and good adhesion to the membrane, such as an ion exchange membrane and a microporous membrane, with a worn electrode, with a feed conductor not having a catalytic coating, and economy, and moreover, is preferably 15 mg / cm ² or less, for general reasons including manufacturability, adhesion strength and economy. The lower limit is not particularly limited, but is, for example, on the order of 1 mg / cm ² .

The above-described mass per unit area may be within the above-described range, for example, by appropriately adjusting the below-described open porosity ratio, electrode thickness, and the like. More specifically, for example, when the thickness is constant, a higher open porosity ratio results in a decrease in mass per unit area, and a lower open porosity ratio results in a higher mass per unit area.

[1107] The applied force can be measured by methods (i) or (ii) described below, which are set out in more detail in the Examples. With regard to the applied force, the value obtained by measurement by method (i) (also called “applied force (1)” ") and the value obtained by measurement by method (ii) (also called" applied force (2) ”") , can be the same or different, and each of the values is preferably less than 1.5 N / (mg · cm ² ).

[1108] [Method (i)]

Nickel plate blasted with alumina 320 grit (thickness 1.2 mm, square with side 200 mm), ion-exchange membrane obtained by applying particles of inorganic material and a binder to both surfaces of a perfluorocarbon polymer into which an ion-exchange group is introduced (square with a side of 170 mm, the details of the ion exchange membrane specified here are described in the Examples), and a sample electrode (square with a side of 130 mm) is layered in that order. Thereafter, the laminated product is sufficiently immersed in clean water, and excess water deposited on the surface of the laminated product is removed to obtain a sample for measurement. The arithmetic mean (Ra) of the surface roughness of a nickel plate after blasting is 0.5 to 0.8 μm. A specific method for calculating the arithmetic mean (Ra) of the surface roughness is as described in the Examples.

Under the condition of temperature 23 ± 2 ° C and relative humidity 30 ± 5%, only the electrode sample in this measurement sample is lifted in the vertical direction at a speed of 10 mm / minute using a tensile compression machine and the load is measured when the electrode sample is lifted 10 mm vertically. This measurement is repeated three times and the average is calculated.

This average value is divided by the area of the overlapping area of the electrode sample and the ion exchange membrane and by the mass of the ion exchange membrane in the area of overlapping with the electrode sample to calculate the applied force per unit mass · unit area (1) (N / (mg · cm ² )).

[1109] The applied force per unit mass · unit area (1) obtained by method (i) is preferably 1.6 N / (mg · cm ² ) or less, more preferably less than 1.6 N / (mg · cm ² ), further preferably less than 1.5 N / (mg cm ² ), even more preferably 1.2 N / (mg cm ² ) or less, even more preferably 1.20 N / (mg cm ² ) or less in terms of providing good processability and good adhesion to a membrane such as an ion exchange membrane or a microporous membrane, a worn electrode, and an uncatalyzed supply conductor. The applied force is even more preferably 1.1 N / (mg cm ² ) or less, further more preferably 1.10 N / (mg cm ² ) or less, particularly preferably 1.0 N / (mg cm ² ) or less, particularly preferably 1.00 N / (mg · cm ² ) or less. The force is preferably more than 0.005 N / (mg cm ² ), more preferably 0.08 N / (mg cm ² ) or more, further preferably 0.1 N / (mg cm ² ) or more in view of further improvement electrolysis productivity, and, moreover, more preferably 0.14 N / (mg cm ² ), even more preferably 0.2 N / (mg cm ² ) or more from the standpoint of further facilitating handling of loading and unloading at a large size (for example, size 1.5 mx 2.5 m).

[1110] [Method (ii)]

A nickel plate blasted with alumina 320 grit (thickness 1.2 mm, square with a side of 200 mm, a nickel plate similar to the plate in the above method (i)), and an electrode sample (square with a side of 130 mm) is layered in this okay. Thereafter, the laminated product is sufficiently immersed in clean water, and excess water deposited on the surface of the laminated product is removed to obtain a sample for measurement. Under the condition of temperature 23 ± 2 ° C and relative humidity 30 ± 5%, only the electrode sample in this measurement sample is lifted in the vertical direction at a speed of 10 mm / minute using a tensile compression machine and the load is measured when the electrode sample is lifted 10 mm vertically. This measurement is repeated three times and the average is calculated.

This average value is divided by the area of the overlapping area of the electrode sample and the nickel plate and by the weight of the electrode sample in the overlapping area with the nickel plate to calculate the applied force per unit mass · unit area (2) (N / (mg · cm ² )).

[1111] The applied force per unit mass · unit area (2) obtained by method (ii) is preferably 1.6 N / (mg · cm ² ) or less, more preferably less than 1.6 N / (mg · cm ² ), further preferably less than 1.5 N / (mg cm ² ), even more preferably 1.2 N / (mg cm ² ) or less, even more preferably 1.20 N / (mg cm ² ) or less in terms of providing good processability and good adhesion to a membrane such as an ion exchange membrane or a microporous membrane, a worn electrode, and an uncatalyzed supply conductor. The applied force is even more preferably 1.1 N / (mg cm ² ) or less, further more preferably 1.10 N / (mg cm ² ) or less, particularly preferably 1.0 N / (mg cm ² ) or less, particularly preferably 1.00 N / (mg · cm ² ) or less. In addition, the force is preferably more than 0.005 N / (mg cm ² ), more preferably 0.08 N / (mg cm ² ) or more, further preferably 0.1 N / (mg cm ² ) or more from the point in view of further improving the electrolysis productivity, and, moreover, is more preferably 0.14 N / (mg cm ² ) or more from the standpoint of further facilitating the handling of a large size (for example, 1.5 m × 2.5 m).

[1112] The electrolysis electrode of the present embodiment preferably comprises an electrolysis electrode support and a catalyst layer. The thickness of the electrode substrate for electrolysis (measured thickness) is, but is not particularly limited, preferably 300 μm or less, more preferably 205 μm or less, even more preferably 155 μm or less, further preferably 135 μm or less, even more preferably 125 μm or less, even more preferably 120 μm or less, even more preferably 100 μm or less from the point of view of ensuring good processability, achieving good adhesion to a membrane such as an ion exchange membrane or a microporous membrane, with a worn electrode (supply conductor) and an electrode ( feed conductor), which does not have a catalytic coating, being suitable for roll-up and satisfactory folding into folds and facilitates loading and unloading at a large size (for example, size 1.5 mx 2.5 m), and, in addition, still more preferably 50 µm or less in terms of processability and economy. The lower limit is not particularly limited, but is, for example, 1 µm, preferably 5 µm, more preferably 15 µm.

[1113] In the method for manufacturing an electrolytic cell of the present embodiment, in order to combine the new membrane and the electrode for electrolysis, a liquid is preferably interposed therebetween. Any liquid such as water or organic solvents can be used as the liquid, provided that the liquid creates surface tension. The higher the surface tension of the liquid, the greater the force applied between the new membrane and the electrolysis electrode. Thus, a liquid having a higher surface tension is preferred. Examples of liquid include the following (the numerical value in parentheses represents the surface tension of the liquid at 20 ° C):

hexane (20.44 mN / m), acetone (23.30 mN / m), methanol (24.00 mN / m), ethanol (24.05 mN / m), ethylene glycol (50.21 mN / m) and water (72.76 mN / m).

The liquid having a high surface tension allows the new membrane and the electrolysis electrode to be combined (to form a laminated article), thereby facilitating the renewal of the electrode. The liquid between the new membrane and the electrolysis electrode may be present in such an amount that both of them adhere to each other under the action of surface tension. As a result, after placing the layered article in the electrolytic cell, the liquid, if mixed with the electrolyte solution, does not affect the electrolysis itself due to the small amount of liquid.

From a practical point of view, a liquid having a surface tension of 24 mN / m to 80 mN / m such as ethanol, ethylene glycol and water is preferably used as the liquid. Particularly preferred is water or an aqueous alkali solution obtained by dissolving caustic soda, potassium hydroxide, lithium hydroxide, sodium hydrogencarbonate, potassium hydrogencarbonate, sodium carbonate, potassium carbonate or the like in water. Alternatively, the surface tension can be adjusted by bringing these fluids into contact with a surfactant. When a surfactant is contained, the bond strength between the new membrane and the electrolysis electrode changes, allowing for customization of workability. The surfactant is not particularly limited, and both ionic surfactants and nonionic surfactants can be used.

[1114] The proportion measured by the following method (2) on the electrode for electrolysis in the present embodiment is not particularly limited, but is preferably 90% or more, more preferably 92% or more from the viewpoint of providing good workability and achieving good adhesion strength with membrane, such as an ion exchange membrane or a microporous membrane, with a worn electrode (supply conductor) and an electrode (supply conductor) not having a catalytic coating, and additionally preferably 95% or more from the point of view of further facilitating handling when large size (for example , size 1.5 m × 2.5 m). The upper limit value is 100%.

[Method (2)]

An ion exchange membrane (170 mm square) and an electrode sample (130 mm square) are layered in this order. The laminated product is placed on the curved surface of a polyethylene pipe (outer diameter: 280 mm) so that the electrode sample in this laminated product is positioned outside at a temperature of 23 ± 2 ° C and a relative humidity of 30 ± 5%, the laminated product and the pipe are sufficiently immersed into clean water, remove the excess water deposited on the surface of the laminated product and the pipe, and then, one minute after this removal, measure the fraction (%) of the area of the area in which the ion-exchange membrane (square with a side of 170 mm) is in close contact with electrode.

[1115] The proportion measured by the following method (3) on the electrode for electrolysis in the present embodiment is not particularly limited, but is preferably 75% or more, more preferably 80% or more from the viewpoint of ensuring good workability, achieving good adhesion strength with membrane, such as an ion exchange membrane or a microporous membrane, with a worn electrode (supply conductor) and an electrode (supply conductor) not having a catalytic coating, and for proper roll-winding and satisfactory creasing, and is additionally preferably 90% or more from the point of view of additional facilitation of loading and unloading at a large size (for example, size 1.5 mx 2.5 m) The upper limit value is 100%.

[Method (3)]

An ion exchange membrane (170 mm square) and an electrode sample (130 mm square) are layered in this order. The laminated product is placed on the curved surface of a polyethylene pipe (outer diameter: 145 mm) so that the electrode sample in this laminated product is positioned externally at a temperature of 23 ± 2 ° C and a relative humidity of 30 ± 5%, the laminated product and the pipe are sufficiently immersed into clean water, remove the excess water deposited on the surface of the laminated product and the pipe, and then, one minute after this removal, measure the fraction (%) of the area of the area in which the ion-exchange membrane (square with a side of 170 mm) is in close contact with electrode.

[1116] The electrode for electrolysis in the present embodiment has, but is not limited to, a porous structure and an open porosity ratio or void ratio of 5 to 90% or less from the viewpoint of ensuring good processability, achieving good adhesion to a membrane such as ion exchange a membrane or microporous membrane, with a worn electrode (supply conductor) and an electrode (supply conductor) not having a catalytic coating, and preventing the accumulation of gas evolved during electrolysis, although not specifically limited thereto. The open porosity ratio is more preferably 10 to 80% or less, more preferably 20 to 75%.

The open porosity ratio is the fraction of the lumen areas per unit volume. The calculation method may differ depending on whether sub-micron-sized gaps are considered or only visible gaps are considered. In the present embodiment, the volume V was calculated from the values of the measured thickness, the width and the length of the electrode, and in addition, the weight W was measured to thereby calculate the open porosity coefficient A by the following formula.

A = (1– (W / (V × ρ)) × 100

ρ is the density of the electrode material (g / cm ³ ). For example, the ρ of nickel is 8.908 g / cm ³ and the ρ of titanium is 4.506 g / cm ³ . The open porosity ratio is appropriately controlled by changing the area of perforated metal per unit area in the case of perforated metal sheet, by changing the values of SW (short diameter), LW (long diameter) and feed in case of expanded metal sheet, by changing the linear dimensions of the metal fiber diameter and number sieves in the case of a mesh, a change in the photoresist pattern used in the case of electrospinning, a change in the diameter of a metal fiber and a fiber density in the case of a nonwoven fabric, a change in a mold for forming cavities in the case of a porous metal, or the like.

[1117] Hereinafter, a more specific embodiment of the electrode for electrolysis in the present embodiment will be described.

The electrolysis electrode of the present embodiment preferably comprises an electrolysis electrode support and a catalyst layer. The catalyst bed can be composed of multiple layers, as shown below, or can have a single layer configuration.

As shown in FIG. 119, the electrolysis electrode 100 of the present embodiment includes an electrolysis electrode substrate 10 and a pair of first layers 20 that cover both surfaces of the electrolysis electrode substrate 10. The first layers 20 preferably cover the entire electrode substrate 10 for electrolysis. Apparently, this coating increases the catalytic activity and durability of the electrode. One first layer 20 can only be laminated to one surface of the electrolysis electrode substrate 10.

In addition, as shown in Figure 119, the surfaces of the first layers 20 can be coated with the second layers 30. The first layers 20 are preferably covered with the second layers 30 in their entirety. Alternatively, one second layer 30 may be laminated to only one surface of the first layer 20.

[1118] (Electrode support for electrolysis)

As the electrode substrate 10 for electrolysis, for example, nickel, nickel alloys, stainless steel, or valve metals, including titanium, can be used, although not limited thereto. Substrate 10 preferably contains at least one element selected from nickel (Ni) and titanium (Ti).

When stainless steel is used in an aqueous alkali solution of high concentration, iron and chromium are washed out and the electrical conductivity is in the order of one tenth that of nickel. In view of the above, as the electrode substrate for electrolysis, a substrate containing nickel (Ni) is preferable.

Alternatively, when the electrode substrate 10 for electrolysis is used in a brine with a high concentration close to saturation, in an atmosphere in which chlorine gas is generated, the material of the electrode substrate 10 is also preferably titanium having high corrosion resistance.

The shape of the electrode substrate 10 for electrolysis is not particularly limited, and a shape suitable for this purpose can be selected. As the mold, any of a perforated metal sheet, a nonwoven fabric, a porous metal, an expanded metal sheet, an electrospinning metal porous foil, a so-called woven metal mesh, and the like can be used. Of these, perforated metal sheet or expanded metal sheet is preferable. Electrospinning is a method of producing a thin metal foil having a precisely shaped pattern using photolithography and electrodeposition in combination. It is a method involving patterning a substrate with a photoresist and electrodeposition of a portion not protected by the resist to form a metal thin film.

With regard to the shape of the electrode support for electrolysis, a suitable specification depends on the distance between the anode and the cathode in the electrolysis cell. In the case where the distance between the anode and the cathode is finite, the shape of an expanded metal sheet or a perforated metal sheet can be used, and in the case of a so-called zero-gap electrolyzer in which the ion exchange membrane is in contact with the electrode, a formed interlacing of fine metal filaments woven metal mesh, wire mesh, porous metal, metal nonwoven fabric, expanded metal sheet, perforated metal sheet, metal porous foil, and the like, although not limited thereto.

Examples of the electrode substrate 10 for electrolysis include metal porous foil, wire mesh, metal nonwoven fabric, perforated metal sheet, expanded metal sheet, and porous metal.

As the plate material before being processed to form a perforated metal sheet or expanded metal sheet, rolled plate materials and electrolytic foils are preferred. The electrolytic foil is preferably subjected to a further electrodeposition treatment using the same element as its base material as a further treatment to thereby form roughness on one or both of its surfaces.

The thickness of the electrolysis electrode substrate 10 as mentioned above is preferably 300 µm or less, more preferably 205 µm or less, further preferably 155 µm or less, even more preferably 135 µm or less, even more preferably 125 µm or less, even more preferably 120 µm or less, even more preferably 100 µm or less, and further even more preferably 50 µm or less in terms of processability and economy. The lower limit is not particularly limited, but is, for example, 1 µm, preferably 5 µm, more preferably 15 µm.

[1119] In the electrolysis electrode substrate, residual stress during processing is preferably relieved by annealing the electrolysis electrode substrate in an oxidizing atmosphere. It is preferable to form roughness using a steel grid, an alumina grid or the like on the surface of the electrode substrate for electrolysis, followed by acid treatment to increase its surface area in order to improve adhesion to the catalyst layer that is coated on the surface. Alternatively, it is preferable to carry out the electrodeposition treatment using the same element as the substrate to increase the surface area.

[1120] To bring the first layer 20 into intimate contact with the surface of the electrolysis electrode substrate 10, the electrolysis electrode substrate 10 is preferably subjected to a surface area increase treatment. Examples of surface area enhancing treatments include chopped wire blasting, steel grating, alumina grating or the like, acidizing using sulfuric acid or hydrochloric acid, and electrodeposition using the same element as in the substrate. The arithmetic mean (Ra) of the surface roughness on the surface of the substrate is not particularly limited, but is preferably 0.05 µm to 50 µm, more preferably 0.1 to 10 µm, even more preferably 0.1 to 8 µm.

[1121] Next, a case will be described where the electrolysis electrode in the present embodiment is used as an anode for conventional salt electrolysis.

(First layer)

In Figure 119, the first layer 20 contains at least one of ruthenium oxides, iridium oxides and titanium oxides as a catalyst layer. Examples of ruthenium oxide include RuO ₂ . Examples of iridium oxide include IrO ₂ . Examples of titanium oxide include TiO ₂ . The first layer 20 preferably contains two oxides: ruthenium oxide and titanium oxide, or three oxides: ruthenium oxide, iridium oxide and titanium oxide. This makes the first layer 20 more stable and further improves the adhesion to the second layer 30.

[1122] When the first layer 20 contains two oxides: ruthenium oxide and titanium oxide, the first layer 20 preferably contains from 1 to 9 moles, more preferably from 1 to 4 moles of titanium oxide, based on 1 mole of ruthenium oxide contained in the first layer 20 With the compositional ratio of the two oxides in this range, the electrolysis electrode 100 exhibits excellent resistance.

[1123] When the first layer 20 contains three oxides: ruthenium oxide, iridium oxide and titanium oxide, the first layer 20 preferably contains 0.2 to 3 moles, more preferably 0.3 to 2.5 moles of iridium oxide per 1 mol of ruthenium oxide contained in the first layer 20. The first layer 20 preferably contains from 0.3 to 8 moles, more preferably from 1 to 7 moles of titanium oxide, based on 1 mole of ruthenium oxide contained in the first layer 20. With a compositional ratio of three oxides in this range, the electrolysis electrode 100 exhibits excellent resistance.

[1124] When the first layer 20 contains at least two of ruthenium oxide, iridium oxide and titanium oxide, these oxides preferably form a solid solution. The formation of a solid solution of the oxides allows the electrolysis electrode 100 to exhibit excellent resistance.

[1125] In addition to the above-described compositions, oxides of various compositions can be used, provided that at least one of ruthenium oxide, iridium oxide, and titanium oxide is contained. For example, an oxide coating called DSA (R), which contains ruthenium, iridium, tantalum, niobium, titanium, tin, cobalt, manganese, platinum, and the like, can be used as the first layer 20.

[1126] The first layer 20 need not be a single layer and may include multiple layers. For example, the first layer 20 may include a three-oxide layer and a two-oxide layer. The thickness of the first layer 20 is preferably 0.05 to 10 µm, more preferably 0.1 to 8 µm.

[1127] (Second layer)

The second layer 30 preferably contains ruthenium and titanium. This makes it possible to further reduce the electrical overvoltage of chlorine immediately after electrolysis.

[1128] The second layer 30 preferably contains palladium oxide, a solid solution of palladium and platinum oxide, or an alloy of palladium and platinum. This makes it possible to further reduce the electrical overvoltage of chlorine immediately after electrolysis.

[1129] The thicker second layer 30 can maintain the electrolysis performance for a long period of time, but from the standpoint of economy, the thickness is preferably 0.05 to 3 µm.

[1130] Next, a situation will be described where the electrolysis electrode in the present embodiment is used as a cathode for conventional salt electrolysis.

(First layer)

Examples of the components of the first layer 20 as a catalyst layer include elements such as C, Si, P, S, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, In, Sn, Ta, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu, as well as metal oxides and hydroxides.

The first layer 20 may or may not contain at least one of platinum group metals, platinum group metal oxides, platinum group metal hydroxides, and platinum group metal containing alloys.

When the first layer 20 contains at least one of platinum group metals, platinum group metal oxides, platinum group metal hydroxides and alloys containing a platinum group metal, platinum group metals, platinum group metal oxides, platinum group metal hydroxides, and platinum metal containing alloys the groups preferably contain at least one platinum group metal from platinum, palladium, rhodium, ruthenium and iridium.

The platinum group metal is preferably platinum.

As the oxide of the platinum group metal, ruthenium oxide is preferably contained.

As the hydroxide of the platinum group metal, ruthenium hydroxide is preferably contained.

As an alloy of platinum group metals, an alloy of platinum with nickel, iron and cobalt is preferably included.

In addition, if necessary, an oxide or hydroxide of a lanthanide element is preferably contained as the second component. This allows the electrolysis electrode 100 to exhibit excellent resistance.

As the oxide or hydroxide of the lanthanide element, preferably at least one selected from lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium and dysprosium is contained.

In addition, if necessary, a transition metal oxide or hydroxide is preferably contained as the third component.

The addition of the third component allows the electrolysis electrode 100 to exhibit superior resistance and lower electrolysis voltage.

Examples of a preferred combination include only ruthenium, ruthenium + nickel, ruthenium + cerium, ruthenium + lanthanum, ruthenium + lanthanum + platinum, ruthenium + lanthanum + palladium, ruthenium + praseodymium, ruthenium + praseodymium + platinum, ruthenium + praseodymium + platinum + palladium, ruthenium + neodymium, ruthenium + neodymium + platinum, ruthenium + neodymium + manganese, ruthenium + neodymium + iron, ruthenium + neodymium + cobalt, ruthenium + neodymium + zinc, ruthenium + neodymium + gallium, ruthenium + neodymium + sulfur, ruthenium + neodymium + lead , ruthenium + neodymium + nickel, ruthenium + neodymium + copper, ruthenium + samarium, ruthenium + samarium + manganese, ruthenium + samarium + iron, ruthenium + samarium + cobalt, ruthenium + samarium + zinc, ruthenium + samarium + gallium, ruthenium + samarium + sulfur, ruthenium + samarium + lead, ruthenium + samarium + nickel, platinum + cerium, platinum + palladium + cerium, platinum + palladium + lanthanum + cerium, platinum + iridium, platinum + palladium, platinum + iridium + palladium, platinum + nickel + palladium, platinum + nickel + ruthenium, platinum and nickel alloys, platinum and cobalt alloys and platinum and iron alloys.

When platinum-group metals, platinum-group metal oxides, platinum-group metal hydroxides, and platinum-group metal-containing alloys are not contained, the main component of the catalyst is preferably the element nickel.

Preferably, at least one of nickel metal, nickel oxides and hydroxides is contained.

A transition metal can be added as a second component. As the second added component, at least one of titanium, tin, molybdenum, cobalt, manganese, iron, sulfur, zinc, copper and carbon is preferably contained.

Examples of a preferred combination include nickel + tin, nickel + titanium, nickel + molybdenum, and nickel + cobalt.

If necessary, an intermediate layer may be disposed between the first layer 20 and the electrolysis electrode substrate 10. By placing the intermediate layer, the resistance of the electrolysis electrode 100 can be improved.

Preferred as the intermediate layer are those which have an affinity for both the first layer 20 and the electrode substrate 10 for electrolysis. As the intermediate layer, preferred are nickel oxides, platinum group metals, platinum group metal oxides and platinum group metal hydroxides. The intermediate layer can be formed by applying and firing a solution containing the component that forms the intermediate layer. Alternatively, a surface oxide layer can also be formed by subjecting the substrate to heat treatment at a temperature of 300 to 600 ° C. in an air atmosphere. In addition, this layer can be formed by a known method such as a thermal spraying method and an ionic deposition method.

[1131] (Second layer)

Examples of the components of the first layer 30 as a catalyst layer include elements such as C, Si, P, S, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, In, Sn, Ta, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu, as well as metal oxides and hydroxides.

The first layer 30 may or may not contain at least one of platinum group metals, platinum group metal oxides, platinum group metal hydroxides, and platinum group metal containing alloys. Examples of a preferred combination of elements contained in the second layer include those listed for the first layer. The combination of the first layer and the second layer can be a combination in which the compositions are the same and the compositional ratios are different, or it can be a combination of different compositions.

[1132] With regard to the thickness of the catalyst layer, the total thickness of the formed catalyst layer and the intermediate layer is preferably 0.01 µm to 20 µm. With a thickness of 0.01 µm or more, the catalyst layer can sufficiently serve as a catalyst. With a thickness of 20 µm or less, a strong catalyst layer can be formed that is unlikely to separate from the support. The thickness is more preferably 0.05 µm to 15 µm. The thickness is more preferably 0.1 to 10 µm. Even more preferably, the thickness is 0.2 to 8 µm.

[1133] The thickness of the electrode, that is, the combined thickness of the electrolysis electrode support and the catalyst layer, is preferably 315 µm or less, more preferably 220 µm or less, further preferably 170 µm or less, even more preferably 150 µm or less, particularly preferably 145 µm or less, even more preferably 140 µm or less, even more preferably 138 µm or less, further even more preferably 135 µm or less, with respect to the workability of the electrode. A thickness of 135 µm or less can provide good workability. In addition, for similar reasons as above, the thickness is preferably 130 µm or less, more preferably less than 130 µm, even more preferably 115 µm or less, further more preferably 65 µm or less. The lower limit is not particularly limited, but is preferably 1 µm or more, more preferably 5 µm or more for practical reasons, more preferably 20 µm or more. The thickness of the electrode can be determined by measuring with a digital thickness gauge (from Mitutoyo Corporation, minimum scale 0.001 mm). The thickness of the substrate of the electrolysis electrode can be measured in the same manner as in the case of the electrode. The thickness of the catalyst layer can be determined by subtracting the thickness of the electrolysis electrode support from the thickness of the electrode.

[1134] In the method for manufacturing an electrolytic cell of the present embodiment, the electrode for electrolysis preferably contains at least one catalyst component selected from the group consisting of Ru, Rh, Pd, Ir, Pt, Au, Ti, V, Cr, Mn, Fe , Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Ag, Ta, W, Re, Os, Al, In, Sn, Sb, Ga, Ge, B, C, N, O, Si, P , S, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb and Dy, from the standpoint of achieving sufficient electrolysis performance.

[1135] In the present embodiment, from the considerations that the electrode for electrolysis of the present embodiment, if it is an electrode having a wide elastic deformation range, can provide better workability and has better adhesion to a membrane such as an ion exchange membrane or a microporous membrane, with a worn electrode, with a supply conductor not having a catalytic coating, and the like, the thickness of the electrode for electrolysis is preferably 315 μm or less, more preferably 220 μm or less, even more preferably 170 μm or less, even more preferably 150 μm or less, particularly preferably 145 µm or less, even more preferably 140 µm or less, further still more preferably 138 µm or less, even more preferably 135 µm or less. A thickness of 135 µm or less can provide good workability. In addition, for reasons similar to the above, the thickness is preferably 130 µm or less, more preferably less than 130 µm, further preferably 115 µm or less, even more preferably 65 µm or less. The lower limit is not particularly limited, but is preferably 1 µm or more, more preferably 5 µm or more for practical reasons, more preferably 20 µm or more. In the present embodiment, “having a wide elastic range” means that when the electrolysis electrode is wound to form a winding, it is unlikely that winding-induced warping will occur after being released from the wound state. The thickness of the electrolysis electrode when the below-mentioned catalyst layer is provided refers to the total thickness of both the electrolysis electrode support and the catalyst layer.

[1136] (Method for Manufacturing Electrolysis Electrode)

Next, one embodiment of a method for manufacturing an electrode 100 for electrolysis will be described in detail.

In the present embodiment, the electrolysis electrode 100 can be obtained by forming a first layer 20, preferably a second layer 30 on the electrolysis electrode substrate by a method such as firing a coating film in an oxygen atmosphere (pyrolysis) or ion deposition, electrodeposition, or thermal sputtering. The production method of the present embodiment as mentioned above can achieve high formation productivity of the electrolysis electrode 100. More specifically, a catalyst layer is formed on the electrode support for electrolysis by an application step in which a coating liquid containing the catalyst is applied, a drying step in which the coating liquid is dried, and a pyrolysis step in which pyrolysis is performed. Pyrolysis here means that a metal salt, which is to be a precursor, decomposes by heating into a metal or metal oxide and a gaseous substance. The decomposition product depends on the nature of the metal used, the type of salt and the atmosphere in which the pyrolysis is carried out, and many metals tend to form oxides in an oxidizing atmosphere. In the industrial process for making an electrode, pyrolysis is usually performed in air and in many cases a metal oxide or metal hydroxide is formed.

[1137] (Formation of the first layer of the anode)

(Application stage)

The first layer 20 is obtained by applying a solution in which at least one metal salt of ruthenium, iridium and titanium (first coating liquid) is dissolved on the electrode substrate for electrolysis, and then pyrolysis (calcining) the coating liquid in the presence of oxygen. The content of ruthenium, iridium and titanium in the first cover liquid is substantially equivalent to that in the first layer 20.

[1138] The metal salts can be chlorides, nitrates, sulfates, metal alkoxides, and any other form. The solvent of the first coating liquid can be selected depending on the type of metal salt, and water and alcohols such as butanol can be used. As the solvent, water or a mixed solvent of water and alcohol is preferred. The total metal concentration in the first coating liquid in which the metal salts are dissolved is not particularly limited, but is preferably in the range of 10 to 150 g / L in consideration of the thickness of the coating film formed by a single application.

[1139] Examples of the method used as the method for applying the first coating liquid to the electrolysis electrode substrate 10 include a method for dipping the electrolysis electrode substrate 10 into the first coating liquid, a method for applying the first coating liquid with a brush, a rolling method using a sponge roller impregnated the first coating liquid, and an electrostatic coating method in which the electrode substrate 10 for electrolysis and the first coating liquid are charged with opposite charges and sputtering is performed. Among them, a rolling method or an electrostatic coating method is preferable, which has excellent production performance on an industrial scale.

[1140] (Drying step and pyrolysis step)

After applying the first coating liquid to the electrode substrate 100 for electrolysis, it is dried at a temperature of 10 to 90 ° C and subjected to pyrolysis in a roasting furnace heated to a temperature of 350 to 650 ° C. Between drying and pyrolysis, if necessary, a pre-firing can be performed at a temperature of 100 to 350 ° C. The temperature for drying, pre-firing and pyrolysis is appropriately selected depending on the composition and type of solvent of the first coating liquid. A longer period of pyrolysis time in each step is preferable, but from the viewpoint of productivity of producing an electrode, 3 to 60 minutes, more preferably 5 to 20 minutes are preferable.

[1141] The cycle of the above-described application, drying and pyrolysis is repeated to form a coating (first layer 20) to a predetermined thickness. After the first layer 20 is formed and then further post-baked for an extended period of time as required, this can further increase the stability of the first layer 20.

[1142] (Formation of the second layer)

The second layer 30, which is formed if necessary, is obtained, for example, by applying a solution containing a palladium compound and a platinum compound or a solution containing a ruthenium compound and a titanium compound (second coating liquid) on the first layer 20, and then the coating liquid is subjected to pyrolysis in presence of oxygen.

[1143] (Formation of the first cathode layer by pyrolysis method)

(Application stage)

The first layer 20 is obtained by applying a solution in which metal salts in various combinations are dissolved (first coating liquid) on an electrode substrate for electrolysis, and then pyrolysis (calcining) the coating liquid in the presence of oxygen. The metal content in the first coating liquid is substantially equivalent to that in the first layer 20.

[1144] The metal salts can be chlorides, nitrates, sulfates, metal alkoxides, and any other form. The solvent of the first coating liquid can be selected depending on the type of metal salt, and water and alcohols such as butanol can be used. As the solvent, water or a mixed solvent of water and alcohol is preferred. The total metal concentration in the first coating liquid in which the metal salts are dissolved is not particularly limited, but is preferably in the range of 10 to 150 g / L in consideration of the thickness of the coating film formed by a single application.

[1145] Examples of the method used as the method for applying the first coating liquid to the electrolysis electrode substrate 10 include a method of dipping the electrolysis electrode substrate 10 into the first coating liquid, a method for applying the first coating liquid with a brush, a rolling method using a sponge roller impregnated the first coating liquid, and an electrostatic coating method in which the electrode substrate 10 for electrolysis and the first coating liquid are charged with opposite charges and sputtering is performed. Among them, a rolling method or an electrostatic coating method is preferable, which has excellent production performance on an industrial scale.

[1146] (Drying step and pyrolysis step)

After applying the first coating liquid to the electrode substrate 100 for electrolysis, it is dried at a temperature of 10 to 90 ° C and subjected to pyrolysis in a roasting furnace heated to a temperature of 350 to 650 ° C. Between drying and pyrolysis, if necessary, a pre-firing can be performed at a temperature of 100 to 350 ° C. The temperature for drying, pre-firing and pyrolysis is appropriately selected depending on the composition and type of solvent of the first coating liquid. A longer period of pyrolysis time in each step is preferable, but from the viewpoint of productivity of producing an electrode, 3 to 60 minutes, more preferably 5 to 20 minutes are preferable.

[1147] The cycle of the above-described application, drying and pyrolysis is repeated to form a coating (first layer 20) to a predetermined thickness. After the first layer 20 is formed and then further post-baked for an extended period of time as required, this can further increase the stability of the first layer 20.

[1148] (Interlayer formation)

The intermediate layer, which is formed, if necessary, is obtained, for example, by applying a solution containing a palladium compound or a platinum compound (second coating liquid) to a substrate, and then pyrolysis of the coating liquid in the presence of oxygen. Alternatively, the nickel oxide intermediate layer can be formed on the surface of the substrate by heating the substrate only, without applying a solution thereto.

[1149] (Formation of the first cathode layer by ion deposition)

The first layer 20 can also be formed by ion deposition.

The example comprises a method in which a substrate is fixed in a chamber and a ruthenium metal target is irradiated with an electron beam. Particles of vaporized metallic ruthenium are positively charged in the plasma in the chamber, deposited on a negatively charged substrate. The plasma atmosphere is argon and / or oxygen and ruthenium is deposited on the substrate as ruthenium oxide.

[1150] (Formation of the first cathode layer by electrodeposition)

The first layer 20 can also be formed by electrodeposition.

As an example, when the substrate is used as a cathode and is subjected to plating in an electrolyte solution containing nickel and tin, an electrolytic plating of a nickel-tin alloy can be formed.

[1151] (Formation of the first layer of the cathode by thermal spraying)

The first layer 20 can also be formed by thermal spraying.

By way of example, nickel oxide particles sprayed by plasma onto a substrate may form a catalyst bed in which nickel metal and nickel oxide are mixed.

[1152] Next, an ion exchange membrane according to one aspect of the membrane will be described in detail.

[Ion exchange membrane]

The ion exchange membrane is not particularly limited as long as the membrane can be laminated with an electrolysis electrode and a variety of ion exchange membranes can be used. The method for manufacturing an electrolytic cell of the present embodiment preferably employs an ion exchange membrane that has a membrane body containing a hydrocarbon polymer or a fluorine-containing polymer having an ion exchange group and a coating layer provided on at least one surface of the membrane body. It is preferable that the coating layer contains particles of inorganic material and a binder, and the specific surface area of the coating layer is 0.1 to 10 m ² / g. In an ion exchange membrane having such a structure, the effect of gas evolved during electrolysis on the electrolysis performance is small, and stable electrolysis performance can be demonstrated.

The above-described fluoropolymer ion exchange membrane into which an ion exchange group has been introduced contains one of either a sulfonic acid layer having an ion exchange group derived from a sulfo group (a group represented by —SO ₃ ^- , hereinafter also referred to as a “sulfonic acid group”), or a carboxylic acid layer having an ion exchange group derived from a carboxyl group (a group represented as —CO ₂ ^- , hereinafter also referred to as a “carboxylic acid group”). From the point of view of strength and dimensional stability, it is preferable to additionally include core reinforcing materials.

The inorganic material particles and the binder will be described in detail below in the coating layer description section.

[1153] Figure 120 illustrates a schematic sectional view showing one embodiment of an ion exchange membrane. The ion exchange membrane 1 has a membrane body 10 containing a hydrocarbon polymer or a fluorine-containing polymer having an ion exchange group, and coating layers 11a and 11b formed on both surfaces of the membrane body 10.

[1154] In the ion exchange membrane 1, the membrane body 10 includes a sulfonic acid layer 3 having an ion exchange group derived from a sulfo group (a group represented by —SO ₃ ^- , hereinafter also referred to as a “sulfonic acid group”), and a carboxylic acid layer 2, having an ion exchange group derived from a carboxyl group (a group represented by —CO ₂ ^- , hereinafter also referred to as a “carboxylic acid group”), and core reinforcing materials 4 that increase strength and dimensional stability. An ion exchange membrane 1 including a sulfonic acid layer 3 and a carboxylic acid layer 2 is suitably used as an anion exchange membrane.

[1155] The ion exchange membrane may include one of a sulfonic acid layer and a carboxylic acid layer. The ion exchange membrane does not need to be reinforced with core reinforcing materials, and the arrangement of the core reinforcing materials is not limited to the example in FIG. 120.

[1156] (Membrane Body)

First, the membrane body 10 constituting the ion exchange membrane 1 will be described.

The body 10 of the membrane should be such that its function is to provide selective permeation of cations, and contains a hydrocarbon polymer or a fluorine-containing polymer having an ion exchange group. Its configuration and material are not particularly limited, and preferable ones can be appropriately selected.

[1157] The hydrocarbon polymer or fluorine-containing polymer having an ion exchange group in the membrane body 10 can be obtained from a hydrocarbon polymer or a fluorine-containing polymer having an ion exchange group precursor capable of forming an ion exchange group by hydrolysis or the like. More specifically, for example, after a polymer containing a fluorinated hydrocarbon backbone having a side chain that is converted to an ion exchange group by hydrolysis or the like (ion exchange group precursor) is used to obtain a precursor of the membrane body 10, and melt-processable ( below in some cases referred to as "fluoropolymer (s)" ""), the membrane body 10 can be obtained by converting a precursor of an ion exchange group into an ion exchange group.

[1158] The fluorine-containing polymer (s) can be obtained, for example, by copolymerizing at least one monomer selected from the next first group and at least one monomer selected from the next second group and / or the next third group. The fluorine-containing polymer (s) can also be obtained by homopolymerizing one monomer selected from any of the next first group, the next second group, and the next third group.

[1159] Examples of monomers of the first group include vinyl fluoride compounds. Examples of vinyl fluoride compounds include vinyl fluoride, tetrafluoroethylene, hexafluoropropylene, vinylidene fluoride, trifluoroethylene, chlorotrifluoroethylene, and perfluoroalkyl vinyl ethers. In particular, when an ion exchange membrane is used as a membrane for alkaline electrolysis, the vinyl fluoride compound is preferably a perfluorinated monomer, and a perfluorinated monomer selected from the group consisting of tetrafluoroethylene, hexafluoropropylene and perfluoroalkyl vinyl ethers is preferred.

[1160] Examples of monomers of the second group include vinyl compounds having a functional group convertible to an ion exchange group such as a carboxylic acid (carboxylic acid group). Examples of vinyl compounds having a functional group convertible to a carboxylic acid ion exchange group include monomers represented by the formula CF ₂ = CF (OCF ₂ CYF) _s –O (CZF) _t –COOR, in which s is an integer from 0 to 2, t is an integer from 1 to 12, each of Y and Z is independently F or CF ₃ and R is a lower alkyl group (a lower alkyl group is an alkyl group having, for example, 1 to 3 carbon atoms).

[1161] Among them, preferred are compounds represented by the formula CF ₂ = CF (OCF ₂ CYF) _n —O (CF ₂ ) _m —COOR, in which n represents an integer from 0 to 2, m represents an integer from 1 to 4, Y is F or CF ₃ and R is CH ₃ , C ₂ H ₅ or C ₃ H ₇ .

[1162] When the ion exchange membrane is used as a cation exchange membrane for alkaline electrolysis, the perfluoro compound is preferably used at least as a monomer, but the alkyl group (see R values above) of the ester group is lost from the polymer during hydrolysis, and therefore the alkyl group (R) is not must necessarily be a perfluoroalkyl group in which all hydrogen atoms are replaced by fluorine atoms.

[1163] Of the above monomers, the following monomers are more preferred as monomers of the second group:

CF ₂ = CFOCF ₂ –CF (CF ₃ ) OCF ₂ COOCH ₃ ,

CF ₂ = CFOCF ₂ CF (CF ₃ ) O (CF ₂ ) ₂ COOCH ₃ ,

CF ₂ = CF [OCF ₂ –CF (CF ₃ )] ₂ O (CF ₂ ) ₂ COOCH ₃ ,

CF ₂ = CFOCF ₂ CF (CF ₃ ) O (CF ₂ ) ₃ COOCH ₃ ,

CF ₂ = CFO (CF ₂ ) ₂ COOCH ₃ and

CF ₂ = CFO (CF ₂ ) ₃ COOCH ₃ .

[1164] Examples of monomers of the third group include vinyl compounds having a functional group convertible to an ion exchange group of the sulfone type (sulfonic acid group). As vinyl compounds having a functional group convertible to a sulfonic acid ion exchange group, for example, monomers represented by the formula CF ₂ = CFO — X — CF ₂ —SO ₂ F in which X is a perfluoroalkylene group are preferred. Specific examples include the following monomers:

CF ₂ = CFOCF ₂ CF ₂ SO ₂ F,

CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₂ F,

CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ CF ₂ SO ₂ F,

CF ₂ = CF (CF ₂ ) ₂ SO ₂ F,

CF ₂ = CFO [CF ₂ CF (CF ₃ ) O] ₂ CF ₂ CF ₂ SO ₂ F and

CF ₂ = CFOCF ₂ CF (CF ₂ OCF ₃ ) OCF ₂ CF ₂ SO ₂ F.

[1165] Among them, CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ CF ₂ SO ₂ F and CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₂ F are more preferable.

[1166] The copolymer obtained from these monomers can be formed by a polymerization method designed for homopolymerization and copolymerization of ethylene fluoride, in particular, a general polymerization method used for tetrafluoroethylene. For example, in a method using a non-aqueous medium, the polymerization reaction can be carried out in the presence of a free radical polymerization initiator such as a perfluorocarbon peroxide or an azo compound, under conditions of a temperature of 0 to 200 ° C and a pressure of 0.1 to 20 MPa, using an inert solvent, such as a perfluorocarbon or a chlorofluorocarbon.

[1167] In the above copolymerization, the type of combination of the above monomers and their proportions are not particularly limited and are determined depending on the type and amount of functional groups that it is desirable to introduce into the resulting fluorine-containing polymer. For example, when a fluorine-containing polymer containing only a carboxylic acid group is produced, at least one polymer must be selected from each of the above-described first group and second group and copolymerized. In addition, when a fluorine-containing polymer containing only a sulfonic acid group is prepared, at least one polymer must be selected from each of the first group and the third group, and copolymerized. In addition, when a fluorine-containing polymer having a carboxylic acid group and a sulfonic acid group is produced, at least one monomer must be selected from each of the above-described first group, second group and third group and copolymerized. In this case, the target fluorine-containing polymer can also be obtained by separately forming a copolymer including monomers of the above-described first group and second group, and a copolymer including monomers of the above-described first group and third group, and then mixing these copolymers. The composition of the mixture of monomers is not particularly limited, and when the number of functional groups per structural unit of the polymer increases, the proportion of monomers selected from the above-described second group and third group must increase.

[1168] The total ion exchange capacity of the fluorine-containing copolymer is not particularly limited, but is preferably 0.5 to 2.0 mg⋅eq / g, more preferably 0.6 to 1.5 mg⋅eq / g. The total ion exchange capacity here refers to the equivalent of the exchange group per unit weight of dry resin and can be measured by neutralization titration or the like.

[1169] In the membrane body 10 of the ion exchange membrane 1, a sulfonic acid layer 3 containing a fluorine-containing polymer having a sulfonic acid group and a carboxylic acid layer 2 containing a fluorine-containing polymer having a carboxylic acid group are laminated. By providing the membrane body 10 having such a layer configuration, the selective permeability to cations such as sodium ions can be further improved.

[1170] The ion exchange membrane 1 is placed in the electrolytic cell so that generally the sulfonic acid layer 3 is on the anode side of the cell and the carboxylic acid layer 2 is on the cathode side of the cell.

[1171] The sulfonic acid layer 3 is preferably composed of a material having a low electrical resistance and is thicker than the carboxylic acid layer 2 in terms of membrane strength. The thickness of the sulfonic acid layer 3 is preferably 2 to 25 times, more preferably 3 to 15 times the thickness of the carboxylic acid layer 2.

[1172] The carboxylic acid layer 2 preferably has high anion exclusion characteristics even if it is thin. The anion exclusion characteristics herein refer to the characteristic of hindering the incorporation and penetration of anions into or through the ion exchange membrane 1. In order to improve the anion exclusion characteristics, it is effective to place a carboxylic acid layer having a low ion exchange capacity compared to the sulfonic acid layer.

[1173] As the fluorine-containing polymer for use in the sulfonic acid layer 3, a polymer obtained using CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₂ F as the third group monomer is preferable.

[1174] As the fluorine-containing polymer for use in the carboxylic acid layer 2, a polymer obtained using CF ₂ = CFOCF ₂ CF (CF ₂ ) O (CF ₂ ) ₂ COOCH _{3 is} preferred as the monomer of the second group.

[1175] (Coating Layer)

The ion exchange membrane preferably has a coating layer on at least one surface of the membrane body. As shown in Figure 120, in the ion exchange membrane 1, coating layers 11a and 11b are formed on both surfaces of the membrane body 10.

The coating layers contain particles of inorganic material and a binder.

[1176] The average particle size of the inorganic material is preferably 0.90 µm or more. When the average particle size of the inorganic material is 0.90 µm or more, impurity resistance is greatly improved in addition to gas attachment. That is, by increasing the average particle size of the inorganic material as well as keeping the above-mentioned specific surface area, a particularly noticeable effect can be achieved. Uneven particles of inorganic material are preferred insofar as the above average particle size and specific surface area are satisfied. Melting inorganic material particles and raw ore milling inorganic material particles can be used. Preferably, particles of inorganic material obtained by milling raw ore are used.

[1177] The average particle size of the particles of the inorganic material may be 2 µm or less. When the average particle size of the inorganic material is 2 µm or less, damage to the membrane by the inorganic material can be prevented. The average particle size of the inorganic material is more preferably 0.90 to 1.2 µm.

[1178] Here, the average particle size can be measured with a particle size analyzer ("SALD2200", manufactured by SHIMADZU CORPORATION).

[1179] The particles of inorganic material are preferably irregular in shape. Such shapes further improve the resistance to impurities. The particles of inorganic material preferably have a wide particle size distribution.

[1180] The particles of inorganic material preferably contain at least one inorganic material selected from the group consisting of oxides of Group IV elements of the Periodic Table, nitrides of Group IV elements of the Periodic Table, and carbides of Group IV elements of the Periodic Table. From the standpoint of resistance, zirconium oxide particles are more preferable.

[1181] The particles of inorganic material are preferably particles of inorganic material obtained by grinding raw ore from particles of inorganic material, or particles of inorganic material in the form of spherical particles having a uniform diameter, obtained by refining a melt of raw ore from particles of inorganic material.

[1182] Examples of means for grinding raw ore include, but are not specifically limited to, ball mills, bead mills, colloid mills, cone grinders, disc mills, runners, grain mills, hammer mills, granulators, vertical shaft impact crushers (VSI ), leather mills (Wiley mills), roller mills and jet mills. After grinding, the particles are preferably washed. As a washing method, the particles are preferably treated with an acid. This treatment can reduce the amount of impurities such as iron adhered to the surface of the inorganic material particles.

[1183] The coating layer preferably contains a binder. The binder is the component that forms the coating layers by retaining particles of inorganic material on the surface of the ion exchange membrane. The binder preferably contains a fluorine-containing polymer from the standpoint of resistance to electrolyte solution and electrolysis products.

[1184] As the binder, a fluorine-containing polymer having a carboxylic acid group or a sulfonic acid group is more preferable in terms of resistance to electrolyte solution and electrolysis products and adhesion strength to the surface of the ion exchange membrane. When the coating layer is provided on a layer containing a fluorine-containing polymer having a sulfonic acid group (sulfonic acid layer), the fluorine-containing polymer having a sulfonic acid group is even more preferably used as a binder for the coating layer. Alternatively, when the coating layer is provided on a layer containing a fluorine-containing polymer having a carboxylic acid group (carboxylic acid layer), a fluorine-containing polymer having a carboxylic acid group is more preferably used as a binder for the coating layer.

[1185] The content of the particles of inorganic material in the coating layer is preferably 40 to 90% by mass, more preferably 50 to 90% by mass. The content of the binder is preferably 10 to 60% by mass, more preferably 10 to 50% by mass.

[1186] The distribution density of the coating layer in the ion exchange membrane is preferably 0.05 to 2 mg per cm ² . When the ion exchange membrane has ridges (roughness) on its surface, the distribution density of the coating layer is preferably 0.5 to 2 mg per cm ² .

[1187] As a method for manufacturing the coating layer, which is not particularly limited, a known method can be applied. An example is a method comprising applying by spray or the like a coating liquid obtained by dispersing particles of an inorganic material in a solution containing a binder.

[1188] (Core Reinforcement Materials)

The ion exchange membrane preferably has core reinforcing materials disposed within the membrane body.

[1189] Reinforcing materials of the core are elements that increase the strength and dimensional stability of the ion exchange membrane. By placing the reinforcing materials of the core within the body of the membrane, it is possible, in particular, to control the expansion and contraction of the ion exchange membrane in the desired range. Such an ion exchange membrane does not expand or contract more than necessary during electrolysis and the like, and can maintain excellent dimensional stability for a long time.

[1190] The configuration of the core reinforcing materials is not particularly limited, and, for example, the core reinforcing materials may be formed by woven yarns called reinforcing yarns. Reinforcing yarns herein refer to yarns that constitute the constituent core reinforcing materials, can provide the desired dimensional stability and mechanical strength to the ion exchange membrane, and can be stably present in the ion exchange membrane. By using core reinforcing materials obtained by weaving such reinforcing yarns, better dimensional stability and mechanical strength can be imparted to the ion exchange membrane.

[1191] The material of the reinforcing materials of the core and the reinforcing yarns used therefor is not particularly limited, but is preferably a material resistant to acids, alkalis, etc., and a fiber including a fluorine-containing polymer is preferable since long-term heat resistance and chemical resistance are required. ...

[1192] Examples of the fluoropolymer used in core reinforcing materials include polytetrafluoroethylene (PTFE), copolymers of tetrafluoroethylene and perfluoroalkyl vinyl ether (PFA), copolymers of tetrafluoroethylene and ethylene (ETFE), copolymers of tetrafluoroethylene copolymers and copolymers of tetrafluoroethylene copolymers and copolymers of tetrafluoroethylene copolymers PVDF). Among them, fibers including polytetrafluoroethylene are preferably used in terms of heat resistance and chemical resistance.

[1193] The diameter of the reinforcing yarns used for the core reinforcing materials is not particularly limited, but is preferably 20 to 300 denier, more preferably 50 to 250 denier. The weave density (web density per unit length) is preferably 5 to 50 / inch. The shape of the core reinforcing materials is not particularly limited, for example, woven fabric, non-woven fabric and knitted fabric are used, but preferably in the form of woven fabric. The thickness of the woven fabric used is preferably 30 to 250 µm, more preferably 30 to 150 µm.

[1194] As the woven fabric or knitted fabric, monofilaments, multifilaments or yarns thereof, twisted yarns with dangling yarns or the like can be used, and various types of weaving methods such as plain weaving, leno weaving, knitted weaving can be used. cord weave and crinkled chintz (seersucker).

[1195] The braiding and placement of the core reinforcing materials in the membrane body are not particularly limited, and the preferred placement can be appropriately provided in consideration of the size and shape of the ion exchange membrane, physical properties desired for the ion exchange membrane, environmental conditions in use, and the like.

[1196] For example, the core reinforcing materials may be placed along a predetermined direction of the membrane body, but from a dimensional stability point of view, it is preferable that the core reinforcing materials are placed along a predetermined first direction and other core reinforcing materials are placed along a predetermined second direction along essentially perpendicular to the first direction. By placing multiple core reinforcement materials substantially orthogonal within the membrane body, better dimensional stability and mechanical strength in many directions can be imparted. For example, a configuration is preferable in which core reinforcing materials disposed along the longitudinal direction (warp yarns) and core reinforcing materials disposed along the transverse direction (weft yarns) are woven on the surface side of the membrane body. A more preferred configuration is in the form of a plain weave, made and woven by allowing the warp and weft yarns to pass alternately above and below each other, a leno weave in which two base strands are woven into the weft strands in a twist, a matting weave made and woven by inserting the same number of weft yarns or the like into two or more parallel warp yarns, or the like, from the standpoint of dimensional stability, mechanical strength and ease of manufacture.

[1197] It is particularly preferred that the core reinforcing materials are disposed along both directions MD (longitudinal direction) and TD (transverse direction) of the ion exchange membrane. In other words, the core reinforcing materials are preferably plain weave in MD and TD. Here, MD means the direction in which the membrane body and various core materials (for example, reinforcing core materials, reinforcing yarns and consumable yarns described later) move in the later described stage of obtaining the ion exchange membrane (flow direction), and TD means a direction substantially perpendicular to MD ... The yarns weaved along the MD are called MD yarns, and the yarns weaved along the TD are called TD yarns. Typically, the ion exchange membrane used for electrolysis is rectangular, and in many cases, the longitudinal direction is MD and the width direction is TD. By weaving reinforcing core materials that are MD yarns and reinforcing core materials that are TD yarns, better dimensional stability and mechanical strength can be achieved in many directions.

[1198] The placement range of the core reinforcing materials is not particularly limited, and the preferred placement can be appropriately provided in consideration of the physical properties desired for the ion exchange membrane, the environmental conditions in use, and the like.

[1199] The opening ratio of the core reinforcing materials is not particularly limited, but is preferably 30% or more, more preferably 50% or more and 90% or less. The opening ratio is preferably 30% or more in terms of the electrochemical characteristics of the ion exchange membrane, and preferably 90% or less in terms of the mechanical strength of the ion exchange membrane.

[1200] The opening ratio of the reinforcing materials of the core herein refers to the ratio (B / A) of the total surface area (B) through which substances such as ions (electrolyte solution and the cations (eg sodium ions) contained therein) can pass to area (A) of any one surface of the body of the ion exchange membrane. The total surface area (B) through which substances such as ions can pass may refer to the total areas of regions in which cations, electrolyte solution and the like are not retained in the ion exchange membrane by the reinforcing materials of the core and the like contained in the ion exchange membrane. membrane.

[1201] Figure 121 illustrates a schematic view for explaining the relative opening of the core reinforcing materials constituting the ion exchange membrane. Figure 121, in which a portion of the ion exchange membrane is shown enlarged, shows only the configuration of the reinforcing materials 21 and 22 of the core in these regions, without showing other elements.

[1202] By subtracting the total area (C) of the core reinforcing materials from the area of the area surrounded by the core reinforcing materials 21 located along the longitudinal direction and the core reinforcing materials 22 located along the transverse direction, the area including the area (A) of the core reinforcing materials can the total area (B) of the regions through which substances such as ions can pass in the area (A) of the above-described region can be obtained. That is, the relative aperture can be determined by the following formula (I):

Relative aperture = (B) / (A) = ((A) - (C)) / (A) (I)

[1203] Among the reinforcing materials of the core, a film textile thread or highly oriented monofilaments including PTFE is particularly preferred in terms of chemical resistance and heat resistance. More specifically, more preferred are plain weave core reinforcing materials that use 50 to 300 denier film textile yarns made by cutting a PTFE-containing high tenacity porous sheet into ribbon-shaped pieces, or comprising highly oriented PTFE monofilaments of 50 to 300 denier sizes. 300 denier, and which have a weave density of 10 to 50 threads or monofilaments per inch and have a thickness in the range of 50 to 100 microns. The opening ratio of the ion exchange membrane including such core reinforcing materials is more preferably 60% or more.

[1204] Examples of the shape of the reinforcing yarns include round yarns and film threads.

[1205] (Through Holes)

The ion exchange membrane preferably has through holes within the membrane body.

[1206] Through holes refer to holes that can form channels for ions generated during electrolysis and for an electrolyte solution. Through holes, which are tubular holes formed within the membrane body, are formed by dissolving the core consumables (or yarns) described below. The shape, diameter, or the like of the through holes can be controlled by selecting the shape or diameter of the core consumables (yarn consumables).

[1207] The formation of through holes within the ion exchange membrane can provide mobility of the electrolyte solution during electrolysis. The shape of the through holes is not particularly limited, but may be the shape of the core consumable materials used to form the through holes according to the production method described below.

[1208] The through holes are preferably formed to alternately extend on the anode side (sulfonic acid layer side) and cathode side (carboxylic acid layer side) of the core reinforcing materials. With this arrangement, in the region in which the through holes are formed on the cathode side of the core reinforcing materials, ions (eg sodium ions) supplied by the electrolyte solution filling the through holes can also flow to the cathode side of the core reinforcing materials. As a result, the flow of cations is not interrupted, and thus an additional reduction in the electrical resistance of the ion-exchange membrane is possible.

[1209] The through holes may be formed along only one predetermined direction of the membrane body constituting the ion exchange membrane, but are preferably formed along both the longitudinal direction and the transverse direction of the membrane body in view of exhibiting more stable electrolysis characteristics.

[1210] [Manufacturing Method]

A suitable example of a method for manufacturing an ion exchange membrane includes a method comprising the following steps (1) to (6):

Step (1): a step of producing a fluorine-containing polymer having an ion exchange group or an ion exchange group precursor capable of forming an ion exchange group by hydrolysis,

Step (2): a step of weaving at least a plurality of core reinforcing materials, if necessary, and consumable yarns that dissolve in acid or alkali and form through holes, to obtain a reinforcing material in which the consumable yarns are interposed between the core reinforcing materials, being adjacent to each other,

Step (3): a step of converting into a film the above fluorine-containing polymer having an ion exchange group or an ion exchange group precursor capable of forming an ion exchange group by hydrolysis,

Step (4): the step of introducing the above reinforcing materials, if necessary, into the above film to obtain a membrane body, inside which the reinforcing materials are placed,

Stage (5): stage of hydrolysis of the membrane body obtained in stage (4) (stage of hydrolysis) and

Step (6): The step of creating a coating layer on the membrane body obtained in step (5) (application step).

[1211] Next, each of the steps will be described in detail.

[1212] Step (1): the step of obtaining a fluorine-containing polymer

In step (1), the monomeric starting materials described above in groups one to three are used to prepare the fluoropolymer. To regulate the ion-exchange capacity of the fluorine-containing polymer, the composition of the mixture of the starting monomer materials must be controlled during the production of the fluorine-containing polymer forming the said layers.

[1213] Stage (2): the stage of obtaining reinforcing materials

The reinforcing material is a woven fabric obtained by weaving reinforcing yarns or the like. The reinforcing material is embedded in the membrane to thereby form core reinforcing materials. When an ion-exchange membrane with through holes is formed, consumable yarns are additionally woven into the reinforcing material. The amount of consumable yarns contained in this case is preferably 10 to 80% by mass, more preferably 30 to 70% by mass, based on the total reinforcing material. The weaving of the consumable yarns can also prevent slippage of the yarns of the core reinforcing materials.

[1214] Viscose, polyethylene terephthalate (PET), cellulose, polyamide and the like are used as the consumable yarns that are dissolved in the membrane production step or in the electrolysis environment. Also preferred are monofilaments or multifilaments having a thickness of 20 to 50 denier and including polyvinyl alcohol and the like.

[1215] In step (2), the aperture ratio, the placement of the through holes, and the like can be controlled by adjusting the placement of the core reinforcing materials and the yarns consumed.

[1216] Step (3): Film forming step

In step (3), the fluoropolymer obtained in step (1) is formed into a film using an extruder. The film may have a single layer configuration, a two layer configuration of a sulfonic acid layer and a carboxylic acid layer as mentioned above, or a multilayer configuration of three or more layers.

[1217] Examples of the film forming method include the following:

a method in which a fluorine-containing polymer having a carboxylic acid group and a fluorine-containing polymer having a sulfonic acid group are separately formed into films; and

a method in which a fluorine-containing polymer having a carboxylic acid group and a fluorine-containing polymer having a sulfonic acid group are coextruded to form a composite film.

[1218] The number of each tape can be more than one. Co-extrusion of different films is preferred because of their contribution to the increase in bond strength at the interface.

[1219] Step (4): the step of obtaining the membrane body

In step (4), the reinforcing material obtained in step (2) is embedded in the film obtained in step (3) to form a membrane body containing the reinforcing material.

[1220] Preferred examples of a method for forming a membrane body include (i) a method in which a fluorine-containing polymer having a precursor of a carboxylic acid group (e.g., a carboxylate functional group) (hereinafter referred to as a first layer) disposed on the cathode side and a fluorine-containing polymer having a precursor of a sulfonic acid group (for example, a sulfonyl fluoride functional group) (hereinafter, including this layer is called the second layer), is formed into a film by the method of coextrusion, and, if necessary, using a heat source and a vacuum source, a reinforcing material and a composite film from the second layer / the first layer is laminated in this order on a breathable heat-resistant release paper on a flat plate or drum having numerous pores on their surface, and combined at a temperature at which each polymer melts while at the same time evacuating air from under each of the layers by means of reduced pressure ; and (ii) a method in which, in addition to the composite film of the second layer / first layer, a fluorine-containing polymer having a precursor of a sulfonic acid group is separately preformed into a film (third layer), and optionally using a heat source and a source vacuum, the third layer film, the core reinforcing materials and the composite film from the second layer / first layer are laminated in this order on a breathable heat-resistant release paper on a flat plate or drum having multiple pores on their surface and combined at a temperature at which each polymer is melted while pumping air out from under each of the layers by means of reduced pressure.

[1221] Co-extrusion of the first and second layer here helps to increase the bond strength at the interface.

[1222] The method of combining under reduced pressure is characterized by making the third layer on the reinforcing material thicker than in the press-applied method. In addition, since the reinforcing material is fixed to the inner surface of the membrane body, the method provides sufficient retention of the mechanical strength of the ion exchange membrane.

[1223] Embodiments of the layering methods described herein are exemplary, and coextrusion can be performed after the preferred layering configuration (eg, a combination of layers) is appropriately selected in consideration of the desired membrane body layer configurations and physical properties, and the like.

[1224] In order to further improve the electrical characteristics of the ion exchange membrane, it is also possible to additionally place a fourth layer comprising a fluorine-containing polymer having both a precursor of a carboxylic acid group and a precursor of a sulfonic acid group between the first layer and the second layer, or the use of a fourth layer comprising a fluorine-containing polymer having both a precursor of a carboxylic acid group and a precursor of a sulfonic acid group instead of the second layer.

[1225] The method for forming the fourth layer may be a method in which a fluorine-containing polymer having a precursor of a carboxylic acid group and a fluorine-containing polymer having a precursor of a sulfonic acid group are separately prepared and then mixed, or it may be a method in which a monomer is copolymerized having a precursor of a carboxylic acid group; and a monomer having a sulfonic acid precursor.

[1226] When the fourth layer is used as a component of the ion exchange membrane, a coextruded film of the first layer and the fourth layer is formed, in addition, the third layer and the second layer are separately formed into films, and the laminating can be performed in the above manner. Alternatively, three layers of the first layer / fourth layer / second layer can be coextruded simultaneously to form a film.

[1227] In this case, the direction in which the extruded film flows out is MD. As mentioned above, it is possible to form a membrane body containing a fluorine-containing polymer having an ion exchange group on the reinforcing material.

[1228] In addition, the ion exchange membrane preferably has protrusions constituted by a fluorine-containing polymer having a sulfonic acid group, that is, protrusions on the side of the surface constituted by the sulfonic acid layer. As a method for forming such protrusions, which is not particularly limited, a known method including forming protrusions on a resin surface can also be applied. A specific example of the method is a method for embossing the surface of a membrane body. For example, the aforementioned protrusions can be formed using the pre-embossed release paper when the above composite film, reinforcing material, and the like are combined. In the case where the protrusions are formed by embossing, the height and density of the protrusions can be controlled by the shape of the transferred relief (the shape of the release paper).

[1229] (5) Hydrolysis step

At step (5), the stage of hydrolysis of the membrane body obtained at stage (4) is performed to convert the precursor of the ion-exchange group into an ion-exchange group (stage of hydrolysis).

[1230] In step (5), it is also possible to dissolve holes in the membrane body by dissolving and removing consumable yarns introduced into the membrane body by the action of an acid or alkali. The consumable yarns can remain in the through holes without being completely dissolved and removed. The consumable yarns remaining in the through holes can be dissolved and removed by the electrolyte solution when the ion exchange membrane is subjected to electrolysis.

[1231] The consumable yarn is dissolved in acid or alkali at the stage of obtaining an ion exchange membrane or in an electrolysis environment. The consumable yarns are washed out, thereby forming the through-holes at the appropriate locations.

[1232] Step (5) may be performed by immersing the membrane body obtained in step (4) in a hydrolysis solution containing an acid or alkali. An example of a hydrolysis solution that can be used is a mixed solution containing KOH and dimethyl sulfoxide (DMSO).

[1233] The mixed solution preferably contains KOH at a normal concentration of 2.5 to 4.0 and DMSO from 25 to 35% by weight.

[1234] The temperature in the hydrolysis is preferably 70 to 100 ° C. The higher the temperature, the greater the apparent thickness can be. The temperature is more preferably 75 to 100 ° C.

[1235] The duration of hydrolysis is preferably 10 to 120 minutes. The longer the hydrolysis takes, the greater the apparent thickness can be. The duration of the hydrolysis is preferably 20 to 120 minutes.

[1236] The step of forming the through holes by washing out the sacrificial yarns will now be described in more detail. Figures 122 (a) and (b) are schematic views for explaining a method of forming vias in an ion exchange membrane.

[1237] Figures 122 (a) and (b) show reinforcing yarns 52, sacrificial yarns 504a, and through holes 504 formed only by sacrificial yarns 504a, without illustrating other features such as a membrane body.

[1238] First, the reinforcing yarns 52, which are to constitute the core reinforcing materials in the ion exchange membrane, and the consumable yarns 504a for forming the through holes 504 in the ion exchange membrane are used as interlaced reinforcing materials. Then, in step (5), the consumable yarns 504a are washed out to form the through holes 504.

[1239] The above method is simple, since the method of interweaving reinforcing yarns 52 and consumable yarns 504a can be adjusted depending on the order of placement of the reinforcing materials of the core and through holes in the body of the ion exchange membrane.

[1240] Figure 122 (a) illustrates an example of a plain weave reinforcing material in which the reinforcing yarns 52 and the sacrificial yarns 504a are interlaced in both the longitudinal direction and the transverse direction in the paper, and optionally the order of placement of the reinforcing yarns 52 and the sacrificial yarn 504a in the reinforcing material can be changed.

[1241] (6) Application Phase

In step (6), a coating layer can be formed by preparing a coating liquid containing particles of inorganic material obtained by grinding raw ore or melting raw ore and a binder, applying a coating liquid to the surface of the ion exchange membrane obtained in step (5), and drying the coating liquids.

[1242] The preferred binder is a binder obtained by hydrolysis of a fluorine-containing polymer having an ion exchange group precursor with an aqueous solution containing dimethyl sulfoxide (DMSO) and potassium hydroxide (KOH), and then immersing the polymer in hydrochloric acid to replace the counter ion of the ion exchange group with an ion of H ⁺ ( for example, a fluorine-containing polymer having a carboxyl group or a sulfo group). Thus, the polymer is more likely to dissolve in water or ethanol, as mentioned below, which is preferred.

[1243] This binder is dissolved in a mixed solution of water and ethanol. The volume ratio between water and ethanol is preferably 10: 1 to 1:10, more preferably 5: 1 to 1: 5, even more preferably 2: 1 to 1: 2. The particles of inorganic material are dispersed in the dissolving liquid by means of a ball mill, thereby forming a coating liquid. In this case, it is also possible to correct the average particle size and the like of particles by adjusting the duration and speed of rotation during dispersion. The preferred amount of the mixed particles of inorganic material and binder is as mentioned above.

[1244] The concentration of the particles of inorganic material and binder in the coating liquid is not particularly limited, but a free-flowing coating liquid is preferable. This makes it possible to uniformly apply the ion exchange membrane to the surface.

[1245] In addition, a surfactant may be added to the dispersion when particles of inorganic material are dispersed. As the surfactant, nonionic surfactants are preferred and examples include HS-210, NS-210, P-210 and E-212 from NOF CORPORATION.

[1246] The resulting coating liquid is applied to the surface of the ion exchange membrane by spray application or roller coating, thereby forming an ion exchange membrane.

[1247] [Microporous Membrane]

The microporous membrane of the present embodiment is not particularly limited as long as the membrane can be formed to form an electrode laminated article for electrolysis as mentioned above. A variety of microporous membranes can be used.

The porosity of the microporous membrane of the present embodiment is not particularly limited, but may be, for example, 20 to 90, and preferably 30 to 85. The above porosity can be calculated by the following formula:

Porosity = (1– (dry weight of the membrane) / (weight calculated from the volume, calculated from the values of the thickness, width and length of the membrane, and the density of the membrane material)) × 100

The average pore size in the microporous membrane of the present embodiment is not particularly limited and may be, for example, 0.01 µm to 10 µm, preferably 0.05 µm to 5 µm. With regard to the average pore size, for example, the membrane is cut vertically in the direction of thickness, and the cross section is examined by field emission scanning electron microscopy (FE-SEM). The average pore size can be obtained by measuring the diameter of about 100 pores and averaging the results.

The thickness of the microporous membrane of the present embodiment is not particularly limited and may be, for example, 10 µm to 1000 µm, preferably 50 µm to 600 µm. The above thickness can be measured using, for example, a micrometer (manufactured by Mitutoyo Corporation) or the like.

Specific examples of a microporous membrane as above include Zirfon Perl UTP 500 manufactured by Agfa (also referred to as a Zirfon membrane in this embodiment) and are described in International Publication No. WO 2013-183584 and International Publication No. WO 2016-203701.

[1248] In the method for manufacturing an electrolytic cell of the present embodiment, the membrane preferably comprises a first ion exchange resin layer and a second ion exchange resin layer having an EW (ion exchange capacity) value different from the EW of the first ion exchange resin layer. In addition, the membrane preferably contains a first ion exchange resin layer and a second ion exchange resin layer having a different functional group than the functional group in the first ion exchange resin layer. The ion exchange capacity can be adjusted by the introduced functional group, and the functional groups that can be introduced are as mentioned above.

[1249] (Water electrolysis)

The electrolyzer in the present embodiment as an electrolysis cell in the case of water electrolysis has a configuration in which an ion exchange membrane in the electrolysis cell for use in the case of the above conventional salt electrolysis is replaced with a microporous membrane. The supplied raw material, which is water, is different from the material for the electrolytic cell in the case of the above-mentioned conventional salt electrolysis. As for other components, parts similar to those of the electrolysis cell in the case of conventional salt electrolysis can also be used in a water electrolysis cell. Since chlorine gas is generated in the anode chamber in conventional salt electrolysis, titanium is used as the anode chamber material, but in the case of water electrolysis, only oxygen gas is emitted in the anode chamber. Thus, a material identical to that of the cathode chamber can be used. Nickel is one example of this. A catalytic coating for generating oxygen is suitable for coating the anode. Examples of the catalytic coating include metals, oxides and hydroxides of platinum group metals and metals from the transition metal group. For example, elements such as platinum, iridium, palladium, ruthenium, nickel, cobalt, and iron can be used.

Examples of

[1250] Now, the present invention will be described below in more detail with reference to Examples and Comparative Examples, but the present invention is in no way limited to the following Examples.

[1251] <Checking the first embodiment>

As will be described below, Experimental Examples according to the first embodiment are presented (in the section <Verification of the first embodiment>, below, simply referred to as “Examples”) and Experimental Examples not corresponding to the first embodiment (in the section <Verification of the first embodiment>, hereinafter simply referred to as "Comparative Examples"), which are estimated by the following method. Details will be described with reference to Figures 10-21 as appropriate.

[1252] [Evaluation Method]

(1) Coefficient of open porosity

The electrode was cut into pieces with a size of 130 mm × 100 mm. A digital thickness gauge (Mitutoyo Corporation, minimum scale 0.001 mm) was used to calculate the average of 10 points measured uniformly over the plane. The value was used as the thickness of the electrode (measured thickness) to calculate the volume. Thereafter, an electronic balance was used to measure the mass. From the specific gravity of each metal (specific gravity of nickel = 8.908 g / cm ³ , specific gravity of titanium = 4.506 g / cm ³ ), the coefficient of open porosity or the coefficient of voidness was calculated.

[1253] Open porosity ratio (void ratio) (%) = (1– (electrode mass) / (electrode volume × metal specific gravity)) × 100

[1254] (2) Mass per unit area (mg / cm ² )

The electrode was cut into pieces of 130 mm × 100 mm and its mass was measured on an electronic balance. The value was divided by the area (130 mm x 100 mm) to calculate the mass per unit area.

[1255] (3) Force applied per unit mass · unit area (1) (adhesion force) (N / (mg · cm ² ))

[Method (i)]

For measurement, a tensile and compression machine (manufactured by Imada-SS Corporation, main testing machine: tensile and compression testing machine SDT-52NA type, load cell: load cell type SL-6001) was used.

[1256] A 200 mm square nickel plate having a thickness of 1.2 mm was blasted with 320 grit alumina. The arithmetic average (Ra) of the surface roughness of the nickel plate after blasting was 0.7 µm. Here, to measure the surface roughness, an SJ-310 probe-type surface roughness meter (profilometer) (Mitutoyo Corporation) was used. The sample to be measured was placed on the plate surface parallel to the ground surface to measure the arithmetic mean of the roughness Ra under the conditions described below. The measurement was repeated 6 times and the average was taken.

[1257] <Probe shape> apex taper angle = 60 °, tip radius = 2 µm, static measuring force = 0.75 mN.

<Roughness Standard> JIS2001

<Evaluation curve> R

<Filter> GAUSS

<Limit value λc> 0.8 mm

<Limit value λs> 2.5 µm

<Number of sections> 5

<Pre-pass, additional pass> available

This nickel plate was mounted vertically on the bottom grip of a tensile and compression machine.

[1258] The membrane used was the following ion exchange membrane A.

Monofilaments with a size of 90 denier made of polytetrafluoroethylene (PTFE) (hereinafter referred to as PTFE yarns) were used as reinforcing materials of the core. The consumable yarns were yarns obtained by twisting 200 times / meter of six 35 denier polyethylene terephthalate (PET) filaments (hereinafter referred to as PET yarns). First, in each of the TD- and MD-directions, a plain weaving of PTFE yarns and consumable yarns with 24 PTFE yarns / inch was performed so that two consumable yarns were placed between adjacent PTFE yarns to obtain a woven fabric. The resulting woven fabric was subjected to roller compaction to obtain a woven fabric having a thickness of 70 µm.

Then resin A was obtained in the form of a dry resin, which was a copolymer of CF ₂ = CF ₂ and CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ COOCH ₃ and had an ion exchange capacity of 0.85 mg-eq / g, and the resin B in the form of a dry resin, which was a copolymer of CF ₂ = CF ₂ and CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₂ F and had an ion exchange capacity of 1.03 mg⋅eq / g.

Using these resins A and B, a two-layer film X in which the thickness of the resin layer A was 15 µm and the thickness of the resin layer B was 104 µm was obtained by a flat die coextrusion method.

Then release paper (having embossing with a conical shape with a height of 50 μm), reinforcing material and film X were laminated in this order on a hot plate having a heat source and a vacuum source inside and having micropores on its surface, heated and depressurized under surface temperature conditions hot plate 223 ° C and a reduced pressure value of 0.067 MPa for 2 minutes, and then remove the release paper to obtain a composite membrane.

The resulting composite membrane was immersed in an aqueous solution heated to 80 ° C. containing 30% by weight of dimethyl sulfoxide (DMSO) and 15% by weight of potassium hydroxide (KOH) for 20 minutes for saponification. Then the composite membrane was immersed in an aqueous 0.5N hydrochloric acid heated to 50 ° C. sodium hydroxide solution (NaOH) for one hour to replace the counterion of the ion exchange group with Na, and then washed with water. Then the membrane was dried at 60 ° C.

In addition, 20% by mass of zirconium oxide having a primary particle size of 1 μm was added to an ethanol solution with a concentration of 5% by mass of resin B as an acidic resin and dispersed to obtain a slurry, and the slurry was sprayed onto both surfaces of the above composite membrane. the method of spraying a suspension with the formation of coatings of zirconium oxide on the surfaces of the composite membrane to obtain an ion-exchange membrane A. The density of the coating of zirconium oxide, measured by X-ray fluorescence analysis, was 0.5 mg / cm ² . The average particle size was measured with a particle size analyzer (manufactured by SHIMADZU CORPORATION, "SALD (R) 2200").

[1259] The obtained above ion exchange membrane (membrane) was immersed in pure water for 12 hours or more and then used for testing. The membrane was brought into contact with the aforementioned nickel plate completely moistened with pure water and adhered by the surface tension of the water. At this time, the nickel plate and the ion exchange membrane were positioned so that their upper ends coincided.

[1260] A sample of an electrolysis electrode (electrode) used for measurement was cut to form a piece in the form of a square with a side of 130 mm. Ion exchange membrane A was cut to form a 170 mm square fragment. One side of the electrode was sandwiched between two stainless steel plates (thickness: 1 mm, length: 9 mm, width: 170 mm). After positioning so that the center of the stainless steel plates was aligned with the center of the electrode, four clamps were used to evenly secure the electrode and the plates. The stainless steel plates in the center were clamped by the upper clamp of the tensile and compression machine while the electrode was suspended. The load applied by the testing machine at this time was set to 0 N. The combined assembly of stainless steel plates, electrode, and clamps was temporarily removed from the tensile and compressive testing machine and immersed in a bath containing clean water to sufficiently moisten electrode with clean water. Thereafter, the stainless steel plates in the center were again clamped with the upper clamp of the tensile and compression machine while the electrode was suspended.

The upper clamp of the tensile and compressive testing machine was lowered and the sample of the electrolysis electrode was adhered to the surface of the ion exchange membrane by the surface tension of pure water. The size of the engagement surface at this time was 130 mm long and 110 mm wide. The entire electrode and the ion-exchange membrane were sprayed with clean water from a wash bottle in order to sufficiently moisten the membrane and electrode again. Thereafter, a roll formed by winding a 5 mm thick EPDM sponge rubber around a vinyl chloride pipe (outer diameter: 38 mm) was rolled from top to bottom while lightly pressing against the electrode to remove excess pure water. Rolling was carried out only once.

[1261] The electrode was lifted at a speed of 10 mm / minute to start measuring the load, and the load was recorded when the size of the overlapping area of the electrode and membrane reached 130 mm wide and 100 mm long. This measurement was repeated three times and the average was calculated.

This average value was divided by the area of the overlapping area of the electrode and ion-exchange membrane and by the mass of the electrode in the overlap area with the ion-exchange membrane to calculate the force applied per unit mass · unit area (1). The mass of the electrode in the overlapping portion with the ion exchange membrane was determined by proportional division from the value obtained in the above section (2) Mass per unit area (mg / cm ² ).

With regard to the environment in the measurement chamber, the temperature was 23 ± 2 ° C and the relative humidity was 30 ± 5%.

The electrode used in the Examples and Comparative Examples was able to hold on its own and adhere without sliding down or peeling when it was adhered to an ion exchange membrane that was adhered to a vertically fixed nickel plate under surface tension.

A schematic view of the method for evaluating the applied force (1) is shown in FIG. 10.

The lower limit of the tensile testing machine was 0.01 (N).

[1262] (4) Force applied per unit mass · unit area (2) N / (mg · cm ² ) (adhesion force)

[Method (ii)]

For measurement, a tensile and compression machine (manufactured by Imada-SS Corporation, main testing machine: tensile and compression testing machine SDT-52NA type, load cell: load cell type SL-6001) was used.

A nickel plate, identical to the one in Method (i), was mounted vertically on the bottom clamp of a tensile and compression machine.

A sample of the electrolysis electrode (electrode) used for measurement was cut to form a piece in the form of a square with a side of 130 mm. Ion exchange membrane A was cut to form a 170 mm square fragment. One side of the electrode was sandwiched between two stainless steel plates (thickness: 1 mm, length: 9 mm, width: 170 mm). After positioning so that the center of the stainless steel plates was aligned with the center of the electrode, four clamps were used to evenly secure the electrode and the plates. The stainless steel plates in the center were clamped by the upper clamp of the tensile and compression machine while the electrode was suspended. The load applied by the testing machine at this time was set to 0 N. The combined assembly of stainless steel plates, electrode, and clamps was temporarily removed from the tensile and compressive testing machine and immersed in a bath containing clean water to sufficiently moisten electrode with clean water. Thereafter, the stainless steel plates in the center were again clamped with the upper clamp of the tensile and compression machine while the electrode was suspended.

[1263] The upper clamp of the tensile and compression machine was lowered and the electrolysis electrode sample adhered to the surface of the nickel plate by the surface tension of the solution. The size of the engagement surface at this time was 130 mm long and 110 mm wide. The entire electrode and the nickel plate were sprayed with clean water from a wash bottle to sufficiently wet the nickel plate and electrode again. Thereafter, a roll formed by winding a 5 mm thick EPDM spongy rubber around a vinyl chloride tube (outer diameter: 38 mm) was rolled from top to bottom while lightly pressing against the electrode to remove excess solution. Rolling was carried out only once.

The electrode was lifted at a speed of 10 mm / minute to start measuring the load, and the load was recorded when the size of the overlapping area of the electrode and the nickel plate in the longitudinal direction reached 100 mm. This measurement was repeated three times and the average was calculated.

This average value was divided by the area of the overlapping area of the electrode and the nickel plate and by the mass of the electrode in the overlapping area with the nickel plate to calculate the force applied per unit mass · unit area (2). The mass of the electrode in the membrane overlap portion was determined by proportional division from the value obtained in the above section (2) Mass per unit area (mg / cm ² ).

With regard to the environment in the measurement chamber, the temperature was 23 ± 2 ° C and the relative humidity was 30 ± 5%.

The electrode used in the Examples and Comparative Examples was capable of self-adhesion and adhesion without sliding down or peeling when adhered to the vertically supported nickel plate under surface tension.

The lower limit of the tensile testing machine was 0.01 (N).

[1264] (5) Method for evaluating the winding around a string with a diameter of 280 mm (1) (%)

(Membrane and Column)

Evaluation method (1) was carried out according to the following procedure.

The ion exchange membrane A (membrane) obtained in [Method (i)] was cut to form a 170 mm square piece. The ion exchange membrane was immersed in pure water for 12 hours or more and then used for testing. In Comparative Examples 10 and 11, the electrode was hot-pressed with the ion exchange membrane, and thereby a combined unit of the ion exchange membrane and electrode (130 mm square electrode) was obtained. After the ion exchange membrane was completely immersed in pure water, the membrane was placed on the curved surface of a plastic (polyethylene) pipe having an outer diameter of 280 mm. Thereafter, the excess solution was removed with a roller formed by winding a 5 mm thick EPDM sponge rubber around a vinyl chloride pipe (outer diameter: 38 mm). The roll was rolled over the ion exchange membrane from left to right in the schematic view shown in FIG. 11. The roll was carried out only once. One minute thereafter, the proportion of the portion where the ion exchange membrane came into intimate contact with the plastic electrode tube having an outer diameter of 280 mm was measured.

[1265] (6) Method for evaluating the winding around a string with a diameter of 280 mm (2) (%)

(Membrane and electrode)

Evaluation method (2) was carried out according to the following procedure.

The ion exchange membrane A (membrane) obtained in [Method (i)] was cut to form a 170 mm square fragment, and the electrode was cut to form a 130 mm square fragment. The ion exchange membrane was immersed in pure water for 12 hours or more and then used for testing. The ion exchange membrane and electrode were completely immersed in pure water and then layered. This layered product was placed on a curved surface of a plastic (polyethylene) pipe having an outer diameter of 280 mm with the electrode on the outside. Thereafter, the excess solution was removed with a roller formed by winding a 5 mm thick EPDM sponge rubber around a vinyl chloride pipe (outer diameter: 38 mm). The roller was rolled over the ion exchange membrane from left to right in the schematic view shown in Figure 12, pressing lightly on the electrode to remove excess solution. Rolling was carried out only once. One minute thereafter, the proportion of the area where the ion exchange membrane was brought into close contact with the electrode was measured.

[1266] (7) Method for evaluating the winding around a string with a diameter of 145 mm (3) (%)

(Membrane and electrode)

Evaluation method (3) was carried out according to the following procedure.

The ion exchange membrane A (membrane) obtained in [Method (i)] was cut to form a 170 mm square fragment, and the electrode was cut to form a 130 mm square fragment. The ion exchange membrane was immersed in pure water for 12 hours or more and then used for testing. The ion exchange membrane and electrode were completely immersed in pure water and then layered. This layered product was placed on the curved surface of a plastic (polyethylene) pipe having an outer diameter of 145 mm with the electrode on the outside. Thereafter, a roll formed by winding a 5 mm thick closed cell EPDM sponge rubber around a vinyl chloride pipe (outer diameter: 38 mm) was rolled from left to right in the schematic view shown in FIG. 13 while lightly pressing the electrode to remove excess solution. Rolling was carried out only once. One minute thereafter, the proportion of the area where the ion exchange membrane was brought into close contact with the electrode was measured.

[1267] (8) Manufacturability (reaction evaluation)

(A) The ion exchange membrane A (membrane) obtained in [Method (i)] was cut to form a 170 mm square piece, and the electrode was cut into pieces of 95 × 110 mm. The ion exchange membrane was immersed in pure water for 12 hours or more and then used for testing. In each Example, the ion-exchange membrane and the electrode were completely immersed in three solutions: aqueous sodium bicarbonate solution, aqueous 0.1 N. NaOH solution and pure water, then layered and placed stationary on a Teflon plate. The spacing between the anode cell and the cathode cell used in the electrolysis evaluation was adjusted to about 3 cm. The stationary layered article was lifted and the operation of inserting and holding the layered article between them was carried out. This operation was performed by checking the electrode for displacement and drop.

[1268] (B) The ion exchange membrane A (membrane) obtained in [Method (i)] was cut to form a 170 mm square piece, and the electrode was cut into pieces of 95 × 110 mm. The ion exchange membrane was immersed in pure water for 12 hours or more and then used for testing. In each Example, the ion-exchange membrane and the electrode were completely immersed in three solutions: aqueous sodium bicarbonate solution, aqueous 0.1 N. NaOH solution and pure water, then layered and placed stationary on a Teflon plate. The membrane in the laminated product was held by hands at two adjacent corners while lifting the laminated product so that it is vertical. The membrane, held by hands at two adjacent corners, was moved from this state, bringing them close to each other so that the membrane protruded or recessed. This movement was repeated again to check the adherence of the electrode to the membrane. The results were evaluated on a four-point scale from 1 to 4 based on the following indicators:

1: good workability

2: usable

3: operation is difficult

4: essentially unserviceable

Here, a sample of Comparative Example 5 formed with a size equivalent to that of a large electrolytic cell including an electrode with a size of 1.3 mx 2.5 m and an ion exchange membrane with a size of 1.5 mx 2.8 m was subjected to handling. The evaluation result of Comparative Example 5 ("3" as described below) was used as a measure of evaluating the difference between the evaluation of the above (A) and (B) and the evaluation of a large sample. That is, in the case where the evaluation result of the small-sized laminate was "1" or "2", it was judged that no workability problems arise even if the laminate was formed at a large size.

[1269] (9) Evaluation of electrolysis characteristics (voltage (V), current efficiency (%), the total salt concentration of the caustic soda (mn ^-1, 50% based))

The electrolysis performance was evaluated in the following electrolysis experiment.

A titanium anode cell was placed opposite each other, having an anode chamber in which the anode (anode outlet cell) was formed, and a cathode cell having a nickel cathode chamber, in which a cathode (cathode outlet cell) was formed. A pair of seals was placed between the cells, and a layered article (a layered article of ion exchange membrane A and an electrolysis electrode) was placed between the seal and. Then, the anode cell, seal, laminate, seal, and cathode were brought into intimate contact with each other to form an electrolytic cell, and an electrolyzer containing the cell was formed.

[1270] The anode was obtained by applying a mixed solution of ruthenium chloride, iridium chloride and titanium tetrachloride on a titanium substrate, subjected to blasting and acid etching as a pretreatment, followed by drying and firing. The anode was fixed in the anode chamber by welding. As the cathode, the cathode described in each of Examples and Comparative Examples was used. A nickel expanded metal sheet was used as a current collector of the cathode chamber. The down conductor was 95 mm long × 110 mm wide. As the metal elastic body, a mat formed by knitting a thin nickel wire was used. The mat as a metal elastic body was placed on the down conductor. A nickel mesh was placed on top of it, formed by a plain weave of nickel wire having a diameter of 150 μm and a mesh size of 40 mesh, and a Teflon (R) cord made of Teflon (R) was used to fix the four corners of the Ni – mesh to the down conductor. This Ni-grid was used as a supply conductor. This electrolytic cell has a zero-gap design utilizing the repulsive force generated by the mat like a metal resilient body. Seals made of ethylene-propylene-diene rubber (EPDM) were used as seals. The membrane used was an ion exchange membrane A (square with a side of 160 mm) obtained in [Method (i)].

[1271] The above electrolytic cell was used to perform conventional salt electrolysis. The brine concentration (sodium chloride concentration) in the anode chamber was adjusted to 205 g / L. The concentration of sodium hydroxide in the cathode compartment was set to 32% by weight. The temperature of each of the anode chamber and the cathode chamber was adjusted so that the temperature in each chamber could reach 90 ° C. Conventional salt electrolysis was carried out at a current density of 6 kA / m ² , measuring voltage, current density and total salt concentration in caustic soda. The current efficiency here is the ratio of the amount of caustic soda formed to the passed current, and when impurity ions and hydroxide ions, rather than sodium ions, pass through the ion exchange membrane under the influence of the passed current, the current efficiency decreases. The current efficiency was obtained by dividing the number of moles of caustic soda formed during a given time by the number of moles of electrons of current passed during that time. The number of moles of caustic soda was obtained by separating the caustic soda formed during electrolysis into a plastic container and measuring its weight. Shown as the total salt concentration in caustic soda is the value obtained by converting the caustic soda concentration by 50%.

The technical characteristics of the electrode and supply conductor used in each of the Examples and Comparative Examples are shown in Table 1.

[1272] (11) Measurement of the thickness of the catalytic layer, the electrode substrate for electrolysis and the thickness of the electrode

A digital thickness gauge (manufactured by Mitutoyo Corporation, minimum scale 0.001 mm) was used to measure the thickness of the electrolysis electrode substrate by calculating an average of 10 points measured uniformly over the plane. This value was used as the thickness of the electrode substrate for electrolysis (measured thickness). A digital thickness gauge was used to measure the electrode thickness, calculating the average of 10 points, obtained by measuring uniformly over the plane, in the same way as for the electrode substrate. This value was used as the thickness of the electrode (measured thickness). The thickness of the catalytic layer was determined by subtracting the thickness of the electrolysis electrode substrate from the thickness of the electrode.

[1273] (12) Test of elastic deformation of the electrode

Each of the ion exchange membrane A (membrane) and the electrode obtained in [Method (i)] was cut to obtain a 110 mm square sample. The ion exchange membrane was immersed in pure water for 12 hours or more and then used for testing. Thereafter, the ion-exchange membrane and electrode were layered to obtain a laminated product under conditions of temperature: 23 ± 2 ° C and relative humidity: 30 ± 5%, the laminated product was wound around a PVC pipe having an outer diameter of φ32 mm and a length of 20 cm, without any or a gap as shown in Figure 14. The laminated product was secured using a polyethylene cable tie so that the laminated product could not separate from the PVC pipe or loosen. The laminated article was held in this state for 6 hours. After that, the cable tie was removed and the laminated product was unwound from the PVC pipe. Only the electrode was placed on a surface plate (flat plate) and the heights L ₁ and L _{2 of the} portion lifted from the surface plate were measured to determine the average. This value was used as an indicator of electrode deformation. That is, a lower value means that the laminate is less likely to deform.

When expanded metal sheet was used, there were two winding directions: SW-direction and LW-direction. In this test, the laminate was wound in the SW direction.

Deformed electrodes (electrodes that did not return to their original state) were evaluated for softness after plastic deformation according to the method as shown in Figure 15. That is, the deformed electrodes were placed on a membrane completely immersed in pure water. One end of the electrode was fixed and the other raised end was pressed against the membrane to relieve the force, and it was judged whether the deformed electrode was in contact with the membrane.

[1274] (13) Assessment of membrane damage

The following ion exchange membrane B was used as a membrane.

As the reinforcing materials of the core, materials obtained by twisting 900 times / meter of 100 denier polytetrafluoroethylene (PTFE) filaments in the form of filaments (hereinafter referred to as PTFE yarns) were used. As the warp yarns consumable, yarns obtained by twisting 200 times / meter of eight 35 denier polyethylene terephthalate (PET) filaments (hereinafter referred to as PET yarns) were used. As the weft consumable yarns, yarns obtained by twisting 200 times / meter of eight 35 denier polyethylene terephthalate (PET) filaments were used. First, a plain weaving of PTFE yarns and consumable yarns was performed with 24 PTFE yarns / inch so that two consumable yarns were placed between adjacent PTFE yarns, resulting in a woven fabric having a thickness of 100 µm.

Then, polymer (A1) was obtained in the form of a dry resin, which was a copolymer of CF ₂ = CF ₂ and CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ COOCH ₃ and had an ion exchange capacity of 0.92 mg⋅eq / g, and polymer (B1) in the form of a dry resin, which was a copolymer of CF ₂ = CF ₂ and CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₂ F and had an ion exchange capacity of 1.10 mg⋅eq / g. Using these polymers (A1) and (B1), a two-layer film X in which the thickness of the polymer layer (A1) was 25 µm and the thickness of the polymer layer (B1) was 89 µm was obtained by a flat die coextrusion method. As the ion exchange capacity of each polymer, the ion exchange capacity was shown in the case of hydrolysis of the precursors of the ion exchange groups of each polymer for conversion to ion exchange groups.

Separately, polymer (B2) was obtained in the form of a dry resin, which was a copolymer of CF ₂ = CF ₂ and CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₂ F and had an ion exchange capacity of 1.10 mg-eq / g ... This polymer was obtained by single layer extrusion to obtain a Y film having a thickness of 20 μm.

Then release paper, film Y, reinforcing material and film X were laminated in this order on a hot plate having a heat source and a vacuum source inside and having micropores on its surface, heated and depressurized under conditions of a hot plate surface temperature of 225 ° C and a value of reduced pressure of 0.022 MPa for two minutes, and then the release paper was removed to obtain a composite membrane. The resulting composite membrane was immersed in an aqueous solution containing dimethyl sulfoxide (DMSO) and potassium hydroxide (KOH) for one hour to saponify. After that, the membrane was immersed in aqueous 0.5N hydrochloric acid. NaOH solution for one hour to replace the ions attached to the ion-exchange groups with Na, and then washed with water. Then the membrane was dried at 60 ° C.

In addition, polymer (B3) was hydrolyzed in the form of a dry resin, which was a copolymer of CF ₂ = CF ₂ and CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₂ F, had an ion exchange capacity of 1.05 mg-eq. / g, and then converted into an acid-type polymer with hydrochloric acid. Zirconium oxide particles having an average primary particle size of 0.02 μm were added to a mixed 50/50 (mass ratio) solution of water and ethanol in which polymer (B3 ') of this acidic type was dissolved in a proportion of 5% by mass so that the mass the ratio of polymer (B3 ') to zirconium oxide particles was 20/80. Thereafter, the polymer (B3 ') was dispersed in a slurry of zirconium oxide particles with a ball mill to obtain a slurry.

This suspension was sprayed onto both surfaces of an ion exchange membrane and dried to obtain an ion exchange membrane B having a coating layer containing polymer (B3 ') and zirconium oxide particles. The density of the zirconium oxide coating, measured by X-ray fluorescence analysis, was 0.35 mg / cm ² .

[1275] The anode used was the same as in section (9) Evaluation of electrolysis performance.

The cathode used was the cathode described in each of the Examples and Comparative Examples. The down conductor, mat and supply conductor of the cathode chamber used were the same as in section (9) Evaluation of electrolysis performance. That is, a zero-gap structure was provided, using a Ni-grid as the supply conductor and the repulsive force that the mat creates as a metallic elastic body. The seals used were the same as in section (9) Evaluation of electrolysis performance. As the membrane, the ion-exchange membrane B obtained by the above method was used. That is, an electrolyzer equivalent to that shown in section (9) was formed, except that the laminated article of the ion exchange membrane B and the electrolysis electrode was interposed between the pair of seals.

[1276] The above electrolytic cell was used to perform ordinary salt electrolysis. The brine concentration (sodium chloride concentration) in the anode chamber was adjusted to 205 g / L. The concentration of sodium hydroxide in the cathode compartment was set to 32% by weight. The temperature of each of the anode chamber and the cathode chamber was adjusted so that the temperature in each chamber could reach 70 ° C. The electrolysis of common salt was carried out at a current density of 8 kA / m ² . The electrolysis was stopped 12 hours after the start of the electrolysis, and the ion exchange membrane B was removed and examined to assess the state of its damage.

"0" means no damage. A score of "1" to "3" means there is damage, and a higher number means a high degree of damage.

[1277] (14) Ventilation resistance of the electrode

The ventilation resistance of the electrode was measured using a KES-F8 air permeability tester (trade name, KATO TECH CO., LTD.). The unit for ventilation resistance is kPa s / m. The measurement was repeated 5 times, and the average value is shown in Table 2. The measurement was carried out under the following conditions. The temperature of the measuring chamber was 24 ° C and the relative humidity was 32%.

Measurement condition 1 (ventilation resistance 1)

Piston speed: 0.2 cm / s

Purge volume: 0.4 cm ³ / cm ² / s

Measuring range: SENSE L (low)

Sample size: 50mm × 50mm

Measurement condition 2 (ventilation resistance 2)

Piston speed: 2 cm / s

Purge volume: 4 cm ³ / cm ² / s

Measuring range: SENSE M (medium) or H (high)

Sample size: 50mm × 50mm

[1278] [Example 1]

As an electrode substrate for a cathode in electrolysis, an electrolytic nickel foil having a measured thickness of 16 µm was obtained. One surface of this nickel foil was roughened by electrolytic nickel plating. The arithmetic mean Ra of the roughness of the rough surface was 0.71 μm. The surface roughness measurement was performed under the same conditions as in the case of the surface roughness measurement of the blasted nickel plate.

A porous foil was formed by punching this nickel foil into circular holes by punching. The open porosity ratio was 49%.

[1279] A cover fluid for use in forming an electrode catalyst was prepared according to the following procedure. Solutions of ruthenium nitrate having a ruthenium concentration of 100 g / L (from FURUYA METAL Co., Ltd.) and cerium nitrate (from KISHIDA CHEMICAL Co., Ltd.) were mixed so that the molar ratio between ruthenium and cerium was 1: 0.25. This mixed solution was thoroughly mixed and used as a covering liquid for the cathode.

The bath containing the above coating liquid was placed in the lowest position of the roller coater. The vat was positioned such that a coating roll obtained by winding a closed cell type EPDM sponge rubber (INOAC CORPORATION, E-4088, 10 mm thick) around a polyvinyl chloride (PVC) cylinder was always in contact with the casing fluid. A coating roller, around which the same EPDM was wound, was placed on its upper part, and a PVC roller was additionally placed above it. The coating liquid was applied in such a way that the electrode substrate was passed between the second coating roller and the PVC roller in the uppermost position (roller coating method). Then, after drying at 50 ° C for 10 minutes, pre-firing at 150 ° C for 3 minutes and firing at 350 ° C for 10 minutes were carried out. A series of these operations of coating, drying, pre-baking and baking were repeated until a predetermined coating value was reached. The thickness of the electrode made in Example 1 was 24 µm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 8 µm. A coating was also formed on a surface that was not roughened. The thickness was the combined thickness of ruthenium oxide and cerium oxide.

The results of measuring the adhesion force of the electrode made by the above method are shown in Table 2. Sufficient adhesion was observed.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 0 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less under measurement condition 1 and 0.0028 (kPa · s / m) under measurement condition 2.

[1280] The electrode obtained by the above method was cut into pieces of 95 mm in length and 110 mm in width to evaluate the performance of electrolysis. The roughened electrode surface was placed opposite the substantially central position of the side of the carboxylic acid layer of the ion exchange membrane A (size: 160 mm × 160 mm) obtained in [Method (i)] and equilibrated with aqueous 0.1N. NaOH solution, and ensured adhesion to it under the action of the surface tension of the aqueous solution.

Even when the four corners of the membrane-integrated electrode portion, which was obtained by combining the membrane with the electrode, were clamped and suspended so that the membrane-integrated electrode was parallel to the base so that the electrode was facing toward the base, the electrode did not detach or move. In addition, when both ends of one side were clamped and suspended so that the membrane-integrated electrode was perpendicular to the base, the electrode did not detach or move.

The above membrane-integrated electrode was interposed between the anode cell and the cathode cell so that the surface to which the electrode was attached was facing the cathode chamber side. In a sectional structure, a down conductor, a mat, a nickel mesh as a supply conductor, an electrode, a membrane, and an anode were placed in this order from the side of the cathode chamber to form a structure with a zero gap.

The resulting electrode was tested for electrolysis performance. The results are shown in Table 2.

The electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0".

When the amount of coating after electrolysis was measured by X-ray fluorescence analysis (XRF), substantially 100% of the coating remained on the surface that had been roughened, and the coating on the surface that had not been roughened was reduced. This shows that the surface opposite to the membrane (roughened surface) is involved in electrolysis, and other surfaces not opposite the membrane can achieve satisfactory electrolysis performance when the amount of coverage is small or no coating.

[1281] [Example 2]

In Example 2, an electrolytic nickel foil having a measured thickness of 22 µm was used as an electrode substrate for electrolysis at the cathode. One surface of this nickel foil was roughened by an electrolytic nickel plating process. The arithmetic average Ra of the roughness of the rough surface made was 0.96 µm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. The open porosity ratio was 44%. Except for the above, the evaluation was performed in the same manner as in Example 1, and the results are shown in Table 2.

The electrode thickness was 29 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 7 µm. The coating was also formed on a surface that was not roughened.

Sufficient traction was observed.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 0 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less under measurement condition 1 and 0.0033 (kPa · s / m) under measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0".

When the amount of coating after electrolysis was measured by XRF, substantially 100% of the coating remained on the surface that had been roughened, and the coating on the surface that had not been roughened was reduced. This shows that the surface opposite to the membrane (roughened surface) is involved in electrolysis, and other surfaces not opposite the membrane can achieve satisfactory electrolysis performance when the amount of coverage is small or no coating.

[1282] [Example 3]

In Example 3, an electrolytic nickel foil having a measured thickness of 30 µm was used as an electrode substrate for electrolysis at the cathode. One surface of this nickel foil was roughened by an electrolytic nickel plating process. The arithmetic mean Ra of the roughness of the rough surface was 1.38 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. The open porosity ratio was 44%. Except for the above, the evaluation was performed in the same manner as in Example 1, and the results are shown in Table 2.

The electrode thickness was 38 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 8 µm. The coating was also formed on a surface that was not roughened.

Sufficient traction was observed.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 0 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less under measurement condition 1 and 0.0027 (kPa · s / m) under measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0".

When the amount of coating after electrolysis was measured by XRF, substantially 100% of the coating remained on the surface that had been roughened, and the coating on the surface that had not been roughened was reduced. This shows that the surface opposite to the membrane (roughened surface) is involved in electrolysis, and other surfaces not opposite the membrane can achieve satisfactory electrolysis performance when the amount of coverage is small or no coating.

[1283] [Example 4]

In Example 4, an electrolytic nickel foil having a measured thickness of 16 µm was used as an electrode substrate for electrolysis at the cathode. One surface of this nickel foil was roughened by an electrolytic nickel plating process. The arithmetic mean Ra of the roughness of the rough surface was 0.71 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. The open porosity ratio was 75%. Except for the above, the evaluation was performed in the same manner as in Example 1, and the results are shown in Table 2.

The electrode thickness was 24 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 8 µm.

Sufficient traction was observed.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 0 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0023 (kPa · s / m) at measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0".

When the amount of coating after electrolysis was measured by XRF, substantially 100% of the coating remained on the surface that had been roughened, and the coating on the surface that had not been roughened was reduced. This shows that the surface opposite to the membrane (roughened surface) is involved in electrolysis, and other surfaces not opposite the membrane can achieve satisfactory electrolysis performance when the amount of coverage is small or no coating.

[1284] [Example 5]

In Example 5, an electrolytic nickel foil having a measured thickness of 20 µm was used as an electrode substrate for electrolysis at the cathode. Both surfaces of this nickel foil were roughened by an electrolytic nickel plating process. The arithmetic average Ra of the roughness of the rough surface was 0.96 μm. Both surfaces had the same roughness. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. The open porosity ratio was 49%. Except for the above, the evaluation was performed in the same manner as in Example 1, and the results are shown in Table 2.

The electrode thickness was 30 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 10 µm. The coating was also formed on a surface that was not roughened.

Sufficient traction was observed.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 0 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0023 (kPa · s / m) at measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0".

In addition, when the amount of coating after electrolysis was measured by XRF, substantially 100% of the coating remained on both surfaces. In comparison with Examples 1-4, this shows that other surfaces not opposed to the membrane can achieve satisfactory electrolysis performance when the amount of coverage is small or no coating.

[1285] [Example 6]

In Example 6, evaluation was performed in the same manner as in Example 1, except that the coating of the electrode substrate for electrolysis on the cathode was deposited by ion deposition, and the results are shown in Table 2. In ion deposition, film formation was performed using a Ru metal target at a heating temperature of 200 ° C and in an argon / oxygen atmosphere, at a pressure for film formation of 7 × 10 ^–2 Pa. The formed coating was ruthenium oxide.

The electrode thickness was 26 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 10 µm. The coating was also formed on a surface that was not roughened.

Sufficient traction was observed.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 0 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less under measurement condition 1 and 0.0028 (kPa · s / m) under measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0".

[1286] [Example 7]

In Example 7, an electrode substrate for electrolysis at a cathode was obtained by an electrospinning method. The photomask had a shape formed by placing vertically and horizontally squares measuring 0.485 mm × 0.485 mm with an interval of 0.15 mm. Exposure, development, and electrodeposition were sequentially carried out to obtain a porous nickel foil having a measured thickness of 20 μm and an open porosity ratio of 56%. The arithmetic average Ra of the surface roughness was 0.71 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except for the above, the evaluation was performed in the same manner as in Example 1, and the results are shown in Table 2.

The electrode thickness was 37 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 17 µm.

Sufficient adhesion force was observed.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 0 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less under measurement condition 1 and 0.0032 (kPa · s / m) under measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0".

[1287] [Example 8]

In Example 8, an electrode substrate for electrolysis at a cathode was obtained by an electrospinning method. The substrate had a measured thickness of 50 μm and an open porosity ratio of 56%. The arithmetic average Ra of the surface roughness was 0.73 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except for the above, the evaluation was performed in the same manner as in Example 1, and the results are shown in Table 2.

The electrode thickness was 60 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 10 µm.

Sufficient adhesion force was observed.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 0 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less under measurement condition 1 and 0.0032 (kPa · s / m) under measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0".

[1288] [Example 9]

In Example 9, a nickel nonwoven web having a measured thickness of 150 µm and a void ratio of 76% (manufactured by NIKKO TECHNO, Ltd.) was used as an electrode substrate for cathode electrolysis. The nonwoven fabric had a nickel fiber diameter of 40 μm and a basis weight of 300 g / m ² . Except for the above, the evaluation was performed in the same manner as in Example 1, and the results are shown in Table 2.

The electrode thickness was 165 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 15 µm.

Sufficient adhesion force was observed.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 29 mm and the electrode did not return to its original flat state. Then, when evaluating the softness after plastic deformation, the electrode was adhered to the membrane under surface tension. Thus, it was found that the electrode was able to come into contact with the membrane with little force, even if the electrode had plastic deformation, and the electrode had satisfactory workability.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0612 (kPa · s / m) at measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. The electrode had a workability of "2" and was determined to be suitable for use as a large laminated article. Membrane damage was rated as good: "0".

[1289] [Example 10]

In Example 10, a nickel nonwoven fabric having a measured thickness of 200 µm and a void ratio of 72% (manufactured by NIKKO TECHNO, Ltd.) was used as an electrode substrate for cathode electrolysis. The nonwoven fabric had a nickel fiber diameter of 40 µm and a basis weight of 500 g / m ² . Except for the above, the evaluation was performed in the same manner as in Example 1, and the results are shown in Table 2.

The electrode thickness was 215 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 15 µm.

Sufficient adhesion force was observed.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 40 mm, and the electrode did not return to its original flat state. Then, when evaluating the softness after plastic deformation, the electrode was adhered to the membrane under surface tension. Thus, it was found that the electrode was able to come into contact with the membrane with little force, even if the electrode had plastic deformation, and the electrode had satisfactory workability.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0164 (kPa · s / m) at measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. The electrode had a workability of "2" and was determined to be suitable for use as a large laminated article. Membrane damage was rated as good: "0".

[1290] [Example 11]

In Example 11, a porous nickel having a measured thickness of 200 µm and a void ratio of 72% (manufactured by Mitsubishi Materials Corporation) was used as an electrode substrate for cathode electrolysis. Except for the above, the evaluation was performed in the same manner as in Example 1, and the results are shown in Table 2.

The electrode thickness was 210 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 10 µm.

Sufficient traction was observed.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 17 mm and the electrode did not return to its original flat state. Then, when evaluating the softness after plastic deformation, the electrode was adhered to the membrane under surface tension. Thus, it was found that the electrode was able to come into contact with the membrane with little force, even if the electrode had plastic deformation, and the electrode had satisfactory workability.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0402 (kPa · s / m) at measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. The electrode had a workability of "2" and was determined to be suitable for use as a large laminated article. Membrane damage was rated as good: "0".

[1291] [Example 12]

In Example 12, a 200 mesh nickel grid having a wire diameter of 50 µm, a measured thickness of 100 µm and an open porosity ratio of 37% was used as an electrode substrate for cathode electrolysis. Blasting was performed using 320 grit alumina. Blasting did not change the open porosity ratio. It was difficult to measure the surface roughness of the wire mesh. Then, in Example 12, a nickel plate having a thickness of 1 mm was simultaneously blasted during blasting, and the surface roughness of the nickel plate was taken as the surface roughness of the wire mesh. The arithmetic average Ra of the surface roughness was 0.64 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except for the above, the evaluation was performed in the same manner as in Example 1, and the results are shown in Table 2.

The electrode thickness was 110 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 10 µm.

Sufficient traction was observed.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 0.5 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0154 (kPa · s / m) at measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good, like "1". Membrane damage was rated as good: "0".

[1292] [Example 13]

In Example 13, a 150 mesh nickel grid having a wire diameter of 65 µm, a measured thickness of 130 µm and an open porosity ratio of 38% was used as an electrode substrate for cathode electrolysis. Blasting was performed using 320 grit alumina. Blasting did not change the open porosity ratio. It was difficult to measure the surface roughness of the wire mesh. Then, in Example 13, a nickel plate having a thickness of 1 mm was simultaneously blasted during blasting, and the surface roughness of the nickel plate was taken as the surface roughness of the wire mesh. The arithmetic average Ra of the surface roughness was 0.66 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except for the above, the evaluation was performed in the same manner as in Example 1, and the results are shown in Table 2.

The electrode thickness was 133 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 3 µm.

Sufficient traction was observed.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 6.5 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0124 (kPa · s / m) at measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. The electrode had a workability of "2" and was determined to be useful as a large laminated article. Membrane damage was also rated as good: "0".

[1293] [Example 14]

In Example 14, as the electrode substrate for electrolysis at the cathode, a substrate identical to that in Example 3 was used (measured thickness 30 µm and open porosity ratio 44%). The electrolysis performance was evaluated on a structure identical to that in Example 1, except that a nickel mesh was not used as the supply conductor. That is, in the sectional structure, the cell, the current collector, the mat, the electrode combined with the membrane, and the anode were placed in this order from the side of the cathode chamber to form a structure with a zero gap, and the mat served as a supply conductor. Except for the above, the evaluation was performed in the same manner as in Example 1, and the results are shown in Table 2.

Sufficient traction was observed.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 0 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less under measurement condition 1 and 0.0027 (kPa · s / m) under measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0".

[1294] [Example 15]

In Example 15, as the electrode substrate for electrolysis at the cathode, a substrate identical to that in Example 3 was used (measured thickness 30 µm and open porosity ratio 44%). The cathode used in Test Example 1, which was worn out and had an elevated electrolysis voltage, was placed in place of the nickel grid as a supply conductor. Except for the above, the evaluation of the electrolysis characteristics was carried out on a structure identical to that in Example 1. That is, in a sectional structure, a cell, a down conductor, a mat, a cathode that was worn out and had an increased electrolysis voltage (serving as a supply conductor), an electrolysis electrode (cathode), membrane and anode are placed in this order from the cathode chamber side to form a zero-gap structure, and the cathode, which is worn out and has an increased electrolysis voltage, serves as a supply conductor. Except for the above, the evaluation was performed in the same manner as in Example 1, and the results are shown in Table 2.

Sufficient traction was observed.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 0 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less under measurement condition 1 and 0.0027 (kPa · s / m) under measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0".

[1295] [Example 16]

As an electrode substrate for electrolysis at the anode, a titanium foil having a measured thickness of 20 µm was used. Both surfaces of the titanium foil were roughened. A porous foil was formed by punching this titanium foil to form circular holes by punching. The hole diameter was 1 mm and the open porosity ratio was 14%. The arithmetic average Ra of the surface roughness was 0.37 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate.

A cover fluid for use in forming an electrode catalyst was prepared according to the following procedure. Solutions of ruthenium chloride having a ruthenium concentration of 100 g / L (Tanaka Kikinzoku Kogyo KK), iridium chloride having an iridium concentration of 100 g / L (Tanaka Kikinzoku Kogyo KK), and titanium tetrachloride (Wako Pure Chemical Industries, Ltd.) mixed so that the molar ratio of ruthenium element, iridium element and titanium element was 0.25: 0.25: 0.5. This mixed solution was thoroughly mixed and used as an anode coating liquid.

[1296] The bath containing the above coating liquid was placed in the lowest position of the roller coater. The vat was positioned such that a coating roll obtained by winding a closed cell type EPDM sponge rubber (INOAC CORPORATION, E-4088, 10 mm thick) around a polyvinyl chloride (PVC) cylinder was always in contact with the casing fluid. A roller for coating, around which the same EPDM was wound, was placed on its upper part, and a PVC roller was additionally placed above it. The coating liquid was applied in such a way that the electrode substrate was passed between the second coating roller and the PVC roller in the uppermost position (roller coating method). After the above coating liquid was applied to the titanium porous foil, drying was carried out at 60 ° C for 10 minutes and firing at 475 ° C for 10 minutes. A series of these operations of coating, drying, pre-calcining, and calcining were performed several times, and then calcination was carried out at 520 ° C. for one hour.

The electrode obtained by the above method was cut into pieces measuring 95 mm in length and 110 mm in width to evaluate the performance of electrolysis. The cut electrode sample was adhered using the surface tension of an aqueous solution at substantially the central position of the sulfonic acid layer side of the ion exchange membrane A (size: 160 mm × 160 mm) obtained in [Method (i)] and equilibrated with aqueous 0, 1 n. NaOH solution.

[1297] The cathode was obtained according to the following procedure. First, a 40 mesh nickel wire mesh having a wire diameter of 150 µm was prepared as a substrate. After blasting with aluminum oxide as a pretreatment, the wire mesh was immersed in 6-normal hydrochloric acid for 5 minutes, thoroughly washed with clean water and dried.

Then, a ruthenium chloride solution having a ruthenium concentration of 100 g / L (from Tanaka Kikinzoku Kogyo KK) and a cerium chloride solution (from KISHIDA CHEMICAL Co., Ltd.) were mixed so that the molar ratio between ruthenium element and cerium element was 1: 0 , 25. This mixed solution was thoroughly mixed and used as a covering liquid for the cathode.

The bath containing the above coating liquid was placed in the lowest position of the roller coater. The vat was positioned such that a coating roll obtained by winding a closed cell type EPDM sponge rubber (INOAC CORPORATION, E-4088, 10 mm thick) around a polyvinyl chloride (PVC) cylinder was always in contact with the casing fluid. A roller for coating, around which the same EPDM was wound, was placed on its upper part, and a PVC roller was additionally placed above it. The coating liquid was applied in such a way that the electrode substrate was passed between the second coating roller and the PVC roller in the uppermost position (roller coating method). Then thereafter, drying was carried out at 50 ° C for 10 minutes, pre-firing at 300 ° C for 3 minutes, and firing at 550 ° C for 10 minutes. Thereafter, firing was carried out at 550 ° C. for an hour. A series of these operations of coating, drying, pre-firing and firing was repeated.

[1298] A nickel expanded metal sheet was used as a current collector of the cathode chamber. The down conductor was 95 mm long × 110 mm wide. As the metal elastic body, a mat formed by knitting a thin nickel wire was used. The mat as a metal elastic body was placed on the down conductor. A cathode obtained by the above method was placed on top of it, and a cord made of Teflon (R) was used to fix the four corners of the grid to the down conductor.

Even when the four corners of the membrane portion of the membrane-combined electrode, which was obtained by combining the membrane with the electrode, were clamped and suspended so that the membrane-integrated electrode was parallel to the base so that the electrode was facing toward the base, the electrode did not detach or move. In addition, when both ends of one side were clamped and suspended so that the membrane-integrated electrode was perpendicular to the base, the electrode did not detach or move.

[1299] The anode used in Test Example 3, which was worn out and had an increased electrolysis voltage, was fixed in the anode cell by welding, and the above membrane-combined electrode was inserted between the anode cell and the cathode cell so that the surface to which the electrode was attached was facing the side of the anode chamber. That is, in the sectional structure, the cell, the current collector, the mat, the cathode, the membrane, the electrode for electrolysis (titanium porous foil as the anode) and the anode, which was worn out and had an increased electrolysis voltage, were placed in the indicated order from the side of the cathode chamber to form a structure with zero clearance. The anode, which was worn out and had an increased electrolysis voltage, served as a supply conductor. The anode made of titanium porous foil and the anode, which was worn out and had an increased electrolysis voltage, were only in physical contact with each other, and were not bonded to each other by welding.

[1300] The evaluation of this construct was carried out in the same manner as in Example 1, and the results are shown in Table 2.

The electrode thickness was 26 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 6 µm.

Sufficient traction was observed.

When a strain test was performed on the electrode, the average of L ₁ and L ₂ was 4 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0060 (kPa · s / m) at measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good, like "1". Membrane damage was also rated as good: "0".

[1301] [Example 17]

In Example 17, a titanium foil having a measured thickness of 20 µm and an open porosity ratio of 30% was used as an electrode substrate for electrolysis at the anode. The arithmetic average Ra of the surface roughness was 0.37 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except for the above, the evaluation was performed in the same manner as in Example 16, and the results are shown in Table 2.

The electrode thickness was 30 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 10 µm.

Sufficient traction was observed.

When a strain test was performed on the electrode, the average of L ₁ and L ₂ was 5 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less under measurement condition 1 and 0.0030 (kPa · s / m) under measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0".

[1302] [Example 18]

In Example 18, a titanium foil having a measured thickness of 20 µm and an open porosity ratio of 42% was used as an electrode substrate for electrolysis at the anode. The arithmetic average Ra of the surface roughness was 0.38 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except for the above, the evaluation was performed in the same manner as in Example 16, and the results are shown in Table 2.

The electrode thickness was 32 µm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 12 µm.

Sufficient traction was observed.

When a strain test was performed on the electrode, the average of L ₁ and L ₂ was 2.5 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0022 (kPa · s / m) at measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0".

[1303] [Example 19]

In Example 19, a titanium foil having a measured thickness of 50 µm and an open porosity ratio of 47% was used as an electrode substrate for electrolysis at the anode. The arithmetic average Ra of the surface roughness was 0.40 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except for the above, the evaluation was performed in the same manner as in Example 16, and the results are shown in Table 2.

The electrode thickness was 69 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 19 µm.

Sufficient traction was observed.

When a strain test was performed on the electrode, the average of L ₁ and L ₂ was 8 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0024 (kPa · s / m) at measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0".

[1304] [Example 20]

In Example 20, a titanium nonwoven fabric having a measured thickness of 100 µm, a titanium fiber diameter of about 20 µm, a basis weight of 100 g / m ² and an open porosity ratio of 78% was used as an electrode substrate for electrolysis at the anode. Except for the above, the evaluation was performed in the same manner as in Example 16, and the results are shown in Table 2.

The electrode thickness was 114 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 14 µm.

Sufficient traction was observed.

When a strain test was performed on the electrode, the average of L ₁ and L ₂ was 2 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0228 (kPa · s / m) at measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0".

[1305] [Example 21]

In Example 21, a 150 mesh titanium wire mesh having a measured thickness of 120 µm and a titanium fiber diameter of 60 µm was used as an electrode substrate for electrolysis at the anode. The open porosity ratio was 42%. Blasting was carried out using 320 grit alumina. It was difficult to measure the surface roughness of the wire mesh. Then, in Example 21, a titanium plate having a thickness of 1 mm was simultaneously blasted at the time of blasting, and the surface roughness of the titanium plate was taken as the surface roughness of the wire mesh. The arithmetic average Ra of the surface roughness was 0.60 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except for the above, the evaluation was performed in the same manner as in Example 16, and the results are shown in Table 2.

The electrode thickness was 140 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 20 µm.

Sufficient traction was observed.

When a strain test was performed on the electrode, the average of L ₁ and L ₂ was 10 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0132 (kPa · s / m) at measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0".

[1306] [Example 22]

[1307] In Example 22, an anode that was worn out and had an increased electrolysis voltage was used in the same way as in Example 16 as the anode supply conductor, and a titanium nonwoven fabric identical to that in Example 20 was used as the anode. A cathode that was worn out and had an increased electrolysis voltage was used in the same way as in Example 15 as a cathode supply conductor, and a nickel foil electrode identical to that in Example 3 was used as a cathode. In a sectional structure, a cell, a down conductor, a mat, a cathode that was worn out and had an increased (electrical) electrolysis voltage, a nickel porous foil as a cathode, a membrane, a titanium nonwoven fabric as an anode, and an anode that was worn out and had an increased electrolysis voltage were placed in this order from the side of the cathode chamber to form a zero-gap structure, and the cathode and anode, which were worn out and had an increased electrolysis voltage, served as a supply conductor. Except for the above, the evaluation was carried out in the same way as in Example 1, and the results are shown in Table 2.

The thickness of the electrode (anode) was 114 µm, and the thickness of the catalytic layer, which was determined by subtracting the thickness of the electrolysis electrode substrate from the thickness of the electrode (anode), was 14 µm. The thickness of the electrode (cathode) was 38 µm, and the thickness of the catalytic layer, which was determined by subtracting the thickness of the electrolysis electrode substrate from the thickness of the electrode (cathode), was 8 µm.

Sufficient adhesion force was observed at both the anode and cathode.

When the deformation test of the electrode (anode) was carried out, the average of L ₁ and L ₂ was 2 mm. When the deformation test of the electrode (cathode) was carried out, the average of L ₁ and L ₂ was 0 mm.

When the ventilation resistance of the electrode (anode) was measured, the ventilation resistance was 0.07 (kPa s / m) or less under measurement conditions 1 and 0.0228 (kPa s / m) under measurement conditions 2. When the ventilation resistance of the electrode ( cathode), the ventilation resistance was 0.07 (kPa s / m) or less under measurement condition 1 and 0.0027 (kPa s / m) under measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0" for both the anode and cathode. In Example 22, the cathode and anodes were combined by connecting the cathode to one surface of the membrane and the anode to the other surface of the membrane, and evaluated for membrane damage.

[1308] [Example 23]

Example 23 used a microporous membrane "Zirfon Perl UTP 500" manufactured by Agfa.

The Zirfon membrane was immersed in clean water for 12 hours or more and used for testing. Except for the above, the above evaluation was performed in the same way as in Example 3, and the results are shown in Table 2.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 0 mm. It was found that the electrode had a wide range of elastic deformation.

Similar to the situation where an ion exchange membrane was used as the membrane, sufficient adhesion force was observed. The microporous membrane was brought into tight contact with the electrode by surface tension, and the workability was good: "1".

[1309] [Example 24]

As an electrode substrate for electrolysis at the cathode, a carbon fiber woven fabric having a measured thickness of 566 µm was used. A cover fluid for use in forming an electrode catalyst on this carbon fabric was prepared according to the following procedure. A ruthenium nitrate solution having a ruthenium concentration of 100 g / L (from FURUYA METAL Co., Ltd.) and a cerium nitrate solution (from KISHIDA CHEMICAL Co., Ltd.) were mixed so that the molar ratio between ruthenium and cerium was 1 : 0.25. This mixed solution was thoroughly mixed and used as a covering liquid for the cathode.

The bath containing the above coating liquid was placed in the lowest position of the roller coater. The vat was positioned such that a coating roll obtained by winding a closed cell EPDM sponge rubber (INOAC CORPORATION, E-4088 (trade name), 10 mm thick) around a polyvinyl chloride (PVC) ) of the cylinder, was always in contact with the cover fluid. A roller for coating, around which the same EPDM was wound, was placed on its upper part, and a PVC roller was additionally placed above it. The coating liquid was applied in such a way that the electrode substrate was passed between the second coating roller and the PVC roller in the uppermost position (roller coating method). Then, after drying at 50 ° C for 10 minutes, pre-firing at 150 ° C for 3 minutes and firing at 350 ° C for 10 minutes were carried out. A series of these operations of coating, drying, pre-baking and baking were repeated until a predetermined coating value was reached. The thickness of the resulting electrode was 570 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 4 µm. The thickness of the catalytic layer was the combined thickness of ruthenium oxide and cerium oxide.

[1310] The resulting electrode was subjected to electrolysis performance evaluation. The results are shown in Table 2.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 0 mm.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.19 (kPa · s / m) or less at measurement condition 1 and 0.176 (kPa · s / m) at measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0".

The electrode had a workability of "2" and was determined to be suitable for use as a large laminated article.

The electrical voltage was high, membrane damage was rated as "1", and membrane damage was observed. It is assumed that this is due to the action of NaOH, which was formed in the electrode, accumulating at the interface between the electrode and the membrane with an increase in its concentration, due to the high ventilation resistance of the electrode in Example 24.

[1311] [Test Case 1]

In Control Example 1, a cathode was used that had been used as a cathode in a large cell for eight years, which was worn out and showed an increased electrolysis voltage. The above cathode was placed instead of a nickel mesh feed conductor on the cathode chamber mat, and an ion exchange membrane A obtained in [Method (i)] was placed between them. The electrolysis performance was then evaluated. In Control Example 1, the membrane-integrated electrode was not used. In the sectional structure, the cell, the current collector, the mat, the cathode, which was worn out and showed an increased electrolysis voltage, the ion-exchange membrane A and the anodes were placed in the indicated order from the side of the cathode chamber to form a structure with a zero gap.

As a result of evaluating the characteristics of electrolysis to this structure, the voltage was 3.04 V, was 97.0% current efficiency, the total concentration of salt in caustic soda (a value converted based on 50%) was 20 million ^-1. Thus, due to electrode wear, the voltage was high.

[1312] [Test Case 2]

In Control Example 2, a nickel mesh feed conductor was used as the cathode. That is, the electrolysis was carried out on a nickel grid that does not have a catalytic coating.

A nickel mesh cathode was placed on the cathode chamber mat and an ion exchange membrane A obtained in [Method (i)] was placed between them. The electrolysis performance was then evaluated. In the sectional structure of the electrical cell of Test Example 2, a down conductor, mat, nickel mesh, ion exchange membrane A, and anodes were placed in this order from the side of the cathode chamber to form a zero-gap structure.

As a result of evaluating the characteristics of electrolysis to this structure, the voltage was 3.38 V, was 97.7% current efficiency, the total concentration of salt in caustic soda (a value converted based on 50%) was 24 million ^-1. Thus, the voltage was high due to the uncoated cathode catalyst.

[1313] [Test Case 3]

In Control Example 3, an anode was used as the anode, which had been used in a large cell for about eight years, was worn out, and showed an increased electrolysis voltage.

In the sectional design of the electrical cell of Test Example 3, a down conductor, mat, cathode, and ion exchange membrane A obtained in [Method (i)], and an anode that was worn out and showed an increased electrolysis voltage were placed in that order from the side of the cathode chamber to form zero clearance designs.

As a result of evaluating the characteristics of electrolysis to this structure, the voltage was 3.18 V, was 97.0% current efficiency, the total concentration of salt in caustic soda (a value converted based on 50%) was 22 million ^-1. Thus, the electrical voltage was high due to the wear of the anode.

[1314] [Comparative Example 1]

In Comparative Example 1, a fully rolled nickel expanded metal sheet having a measured thickness of 100 µm and an open porosity ratio of 33% was used as an electrode substrate for cathode electrolysis. Blasting was carried out using alumina with a grit number of 320. The open porosity ratio did not change after blasting. It was difficult to measure the surface roughness of expanded metal sheet. Then, in Comparative Example 1, a nickel plate having a thickness of 1 mm was simultaneously blasted during blasting, and the surface roughness of the nickel plate was taken as the surface roughness of the wire mesh. The arithmetic average Ra of the surface roughness was 0.68 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except for the above, the evaluation was performed in the same manner as in Example 1, and the results are shown in Table 2.

The electrode thickness was 114 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 14 µm.

The mass per unit area was 67.5 (mg / cm ² ). The force applied per unit mass · unit area (1) was as small as 0.05 N / (mg · cm ² ). Thus, the result of evaluating the coiling around a string with a diameter of 280 mm (2) was 64%, and the result of evaluating the coiling around a string with a diameter of 145 mm (3) was 22%. The areas where the electrode separated from the membrane were enlarged. This was caused by problems in that the electrode would most likely detach when the combined electrode was used and that the electrode would separate and fall off the diaphragm during loading and unloading. Manufacturability was "4", which was also problematic. Membrane damage was scored "0".

When a strain test was performed on the electrode, the average of L ₁ and L ₂ was 13 mm.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0168 (kPa · s / m) at measurement condition 2.

[1315] [Comparative Example 2]

In Comparative Example 2, a fully rolled nickel expanded metal sheet having a measured thickness of 100 µm and an open porosity ratio of 16% was used as an electrode substrate for cathode electrolysis. Blasting was carried out using alumina with a grit number of 320. The open porosity ratio did not change after blasting. It was difficult to measure the surface roughness of expanded metal sheet. Then, in Comparative Example 2, a nickel plate having a thickness of 1 mm was simultaneously blasted during blasting, and the surface roughness of the nickel plate was taken as the surface roughness of the wire mesh. The arithmetic average Ra of the surface roughness was 0.64 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except for the above, the evaluation was performed in the same manner as in Example 1, and the results are shown in Table 2.

The electrode thickness was 107 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 7 µm.

The mass per unit area was 78.1 (mg / cm ² ). The force applied per unit mass · unit area (1) was as small as 0.04 N / (mg · cm ² ). Thus, the result of evaluating the coiling around a string with a diameter of 280 mm (2) was 37%, and the result of evaluating the coiling around a string with a diameter of 145 mm (3) was 25%. The areas where the electrode separated from the membrane were enlarged. This was caused by problems in that the electrode would most likely detach when the combined electrode was used and that the electrode would separate and fall off the diaphragm during loading and unloading. Manufacturability was "4", which was also problematic. Membrane damage was scored "0".

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 18.5 mm.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0176 (kPa · s / m) at measurement condition 2.

[1316] [Comparative Example 3]

In Comparative Example 3, a fully rolled nickel expanded metal sheet having a measured thickness of 100 µm and an open porosity ratio of 40% was used as an electrode substrate for cathode electrolysis. Blasting was carried out using alumina with a grit number of 320. The open porosity ratio did not change after blasting. It was difficult to measure the surface roughness of expanded metal sheet. Then, in Comparative Example 3, a nickel plate having a thickness of 1 mm was simultaneously blasted during blasting, and the surface roughness of the nickel plate was taken as the surface roughness of the wire mesh. The arithmetic mean Ra of the surface roughness was 0.70 µm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate.

Coating of the electrolysis electrode substrate was performed by ion deposition in the same manner as in Example 6. Except for the above, evaluation was performed in the same manner as in Example 1, and the results are shown in Table 2.

The electrode thickness was 110 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 10 µm.

The force applied per unit mass · unit area (1) was as small as 0.07 N / (mg · cm ² ). Thus, the evaluation result of the coiling around a 280 mm diameter string (2) was 80%, and the evaluation result of the coiling around a 145 mm diameter string (3) was 32%. The areas where the electrode separated from the membrane were enlarged. This was caused by problems in that the electrode would most likely detach when the combined electrode was used and that the electrode would separate and fall off the diaphragm during loading and unloading. Manufacturability was "3", which was also problematic. Membrane damage was scored "0".

When a strain test was performed on the electrode, the average of L ₁ and L ₂ was 11 mm.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less under measurement condition 1 and 0.0030 (kPa · s / m) under measurement condition 2.

[1317] [Comparative Example 4]

In Comparative Example 4, a fully rolled nickel expanded metal sheet having a measured thickness of 100 µm and an open porosity ratio of 58% was used as an electrode substrate for cathode electrolysis. Blasting was carried out using alumina with a grit number of 320. The open porosity ratio did not change after blasting. It was difficult to measure the surface roughness of expanded metal sheet. Then, in Comparative Example 4, a nickel plate having a thickness of 1 mm was simultaneously blasted at the time of blasting, and the surface roughness of the nickel plate was taken as the surface roughness of the wire mesh. The arithmetic average Ra of the surface roughness was 0.64 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except for the above, the evaluation was carried out in the same way as in Example 1, and the results are shown in Table 2.

The electrode thickness was 109 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 9 µm.

The force applied per unit mass · unit area (1) was as small as 0.06 N / (mg · cm ² ). Thus, the result of evaluating the coiling around a string with a diameter of 280 mm (2) was 69%, and the result of evaluating the coiling around a string with a diameter of 145 mm (3) was 39%. The areas where the electrode separated from the membrane were enlarged. This was caused by problems in that the electrode would most likely detach when the combined electrode was used and that the electrode would separate and fall off the diaphragm during loading and unloading. Manufacturability was "3", which was also problematic. Membrane damage was scored "0".

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 11.5 mm.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less under measurement condition 1 and 0.0028 (kPa · s / m) under measurement condition 2.

[1318] [Comparative Example 5]

In Comparative Example 5, a nickel wire mesh having a measured thickness of 300 µm and an open porosity ratio of 56% was used as an electrode substrate for cathode electrolysis. It was difficult to measure the surface roughness of the wire mesh. Then, in Comparative Example 5, a nickel plate having a thickness of 1 mm was simultaneously blasted at the time of blasting, and the surface roughness of the nickel plate was taken as the surface roughness of the wire mesh. Blasting was carried out using alumina with a grit number of 320. The open porosity ratio did not change after blasting. The arithmetic average Ra of the surface roughness was 0.64 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except for the above, the evaluation was carried out in the same way as in Example 1, and the results are shown in Table 2.

The electrode thickness was 308 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 8 µm.

The mass per unit area was 49.2 (mg / cm ² ). Thus, the evaluation result of the coiling around a 280 mm diameter string (2) was 88%, and the evaluation result of the coiling around a 145 mm diameter string (3) was 42%. The areas where the electrode separated from the membrane were enlarged. This was due to the fact that the electrode was most likely detached when an electrode combined with the membrane was used, and that the electrode separated and fell off the membrane during loading and unloading. A problem arose regarding manufacturability, which was rated as "3". When a large electrode was actually operated, the manufacturability could be rated as "3". Membrane damage was scored "0".

When a strain test was performed on the electrode, the average of L ₁ and L ₂ was 23 mm.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0034 (kPa · s / m) at measurement condition 2.

[1319] [Comparative Example 6]

In Comparative Example 6, a nickel wire mesh having a measured thickness of 200 µm and an open porosity ratio of 37% was used as an electrode substrate for cathode electrolysis. Blasting was carried out using alumina with a grit number of 320. The open porosity ratio did not change after blasting. It was difficult to measure the surface roughness of the wire mesh. Then, in Comparative Example 6, a nickel plate having a thickness of 1 mm was simultaneously blasted at the time of blasting, and the surface roughness of the nickel plate was taken as the surface roughness of the wire mesh. The arithmetic average Ra of the surface roughness was 0.65 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except for the above, the evaluation of the electrolysis on the electrode, the measurement results of the adhesion force and the adhesion (adhesiveness) were carried out in the same manner as in Example 1. The results are shown in Table 2.

The electrode thickness was 210 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 10 µm.

The weight per unit area was 56.4 mg / cm ² . Thus, the result of evaluating the winding around the 145 mm diameter column (2) was 63%, and the adhesion between the electrode and the membrane was poor. This was due to the fact that the electrode was most likely detached when an electrode combined with the membrane was used, and that the electrode separated and fell off the membrane during loading and unloading. A problem arose regarding manufacturability, which was rated as "3". Membrane damage was scored "0".

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 19 mm.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less under measurement condition 1 and 0.0096 (kPa · s / m) under measurement condition 2.

[1320] [Comparative Example 7]

In Comparative Example 7, a fully rolled titanium expanded metal sheet having a measured thickness of 500 µm and an open porosity ratio of 17% was used as an electrode substrate for electrolysis at the anode. Blasting was carried out using alumina with a grit number of 320. The open porosity ratio did not change after blasting. It was difficult to measure the surface roughness of expanded metal sheet. Then, in Comparative Example 7, a titanium plate having a thickness of 1 mm was simultaneously blasted at the time of blasting, and the surface roughness of the titanium plate was taken as the surface roughness of the wire mesh. The arithmetic average Ra of the surface roughness was 0.60 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except for the above, the evaluation was carried out in the same way as in Example 16, and the results are shown in Table 2.

The electrode thickness was 508 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 8 µm.

The weight per unit area was 152.5 (mg / cm ² ). The force applied per unit mass · unit area (1) was as small as 0.01 N / (mg · cm ² ). Thus, the result of evaluating the coiling around a string with a diameter of 280 mm (2) was 5%, and the result of evaluating the coiling around a string with a diameter of 145 mm (3) was 5%. The areas where the electrode separated from the membrane were enlarged. This was due to the fact that the electrode most likely separated when an electrode combined with the membrane was used, and that the electrode separated and fell off the membrane during loading and unloading, and so on. Manufacturability was "4", which was also problematic. Membrane damage was scored "0".

When the electrode was deformed, the electrode did not recover and remained coiled in the shape of a PVC pipe. Thus, it was impossible to measure the values of L ₁ and L _2.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0072 (kPa · s / m) at measurement condition 2.

[1321] [Comparative Example 8]

In Comparative Example 8, a fully rolled titanium expanded metal sheet having a measured thickness of 800 µm and an open porosity ratio of 8% was used as an electrode substrate for electrolysis at the anode. Blasting was carried out using alumina with a grit number of 320. The open porosity ratio did not change after blasting. It was difficult to measure the surface roughness of expanded metal sheet. Then, in Comparative Example 8, a titanium plate having a thickness of 1 mm was simultaneously blasted at the time of blasting, and the surface roughness of the titanium plate was taken as the surface roughness of the wire mesh. The arithmetic average Ra of the surface roughness was 0.61 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except for the above, the evaluation was carried out in the same way as in Example 16, and the results are shown in Table 2.

The electrode thickness was 808 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 8 µm.

The mass per unit area was 251.3 (mg / cm ² ). The force applied per unit mass · unit area (1) was as small as 0.01 N / (mg · cm ² ). Thus, the result of evaluating the coiling around a string with a diameter of 280 mm (2) was 5%, and the result of evaluating the coiling around a string with a diameter of 145 mm (3) was 5%. The areas where the electrode separated from the membrane were enlarged. This was due to the fact that the electrode most likely separated when an electrode combined with the membrane was used, and that the electrode separated and fell off the membrane during loading and unloading, and so on. Manufacturability was "4", which was also problematic. Membrane damage was scored "0".

When the electrode was deformed, the electrode did not recover and remained coiled in the shape of a PVC pipe. Thus, it was impossible to measure the values of L ₁ and L _2.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0172 (kPa · s / m) at measurement condition 2.

[1322] [Comparative Example 9]

In Comparative Example 9, a fully rolled titanium expanded metal sheet having a measured thickness of 1000 µm and an open porosity ratio of 46% was used as an electrode substrate for electrolysis at the anode. Blasting was carried out using alumina with a grit number of 320. The open porosity ratio did not change after blasting. It was difficult to measure the surface roughness of expanded metal sheet. Then, in Comparative Example 9, a titanium plate having a thickness of 1 mm was simultaneously blasted at the time of blasting, and the surface roughness of the titanium plate was taken as the surface roughness of the wire mesh. The arithmetic average Ra of the surface roughness was 0.59 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except for the above, the evaluation was carried out in the same way as in Example 16, and the results are shown in Table 2.

The electrode thickness was 1011 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 11 µm.

The mass per unit area was 245.5 (mg / cm ² ). The force applied per unit mass · unit area (1) was as small as 0.01 N / (mg · cm ² ). Thus, the result of evaluating the coiling around a string with a diameter of 280 mm (2) was 5%, and the result of evaluating the coiling around a string with a diameter of 145 mm (3) was 5%. The areas where the electrode separated from the membrane were enlarged. This was due to the fact that the electrode most likely separated when an electrode combined with the membrane was used, and that the electrode separated and fell off the membrane during loading and unloading, and so on. Manufacturability was "4", which was also problematic. Membrane damage was scored "0".

When the electrode was deformed, the electrode did not recover and remained coiled in the shape of a PVC pipe. Thus, it was impossible to measure the values of L ₁ and L _2.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less under measurement condition 1 and 0.0027 (kPa · s / m) under measurement condition 2.

[1323] [Comparative Example 10]

In Comparative Example 10, a membrane and electrode assembly was obtained by thermocompressing an electrode with a membrane with reference to the prior art document (Examples in Japanese Patent Laid-Open No. 58-48686).

A nickel expanded metal sheet having a measured thickness of 100 μm and an open porosity ratio of 33% was used as an electrode substrate for electrolysis on a cathode to perform electrode plating in the same manner as in Example 1. Thereafter, one surface of the electrode was subjected to inactivation treatment according to the following procedure. A polyimide adhesive tape (from Chukoh Chemical Industries, Ltd.) was attached to one surface of the electrode. The other surface was coated with a PTFE dispersion (Dupont-Mitsui Fluorochemicals Co., Ltd., 31-JR (trade name)) and dried in a muffle oven at 120 ° C for 10 minutes. The polyimide tape was separated and fired in a muffle furnace adjusted to a temperature of 380 ° C for 10 minutes. This operation was repeated twice to inactivate one surface of the electrode.

[1324] Received a membrane formed of two layers of a perfluorocarbon polymer, the end group of which is "-COOCH ₃ " (C-polymer), and a perfluorocarbon polymer, the end group of which is "-SO ₂ F" (S-polymer). The C-polymer layer was 3 mils (0.003 in., 0.0762 mm) thick and the S-polymer layer was 4 mils (0.004 in., 0.01 mm) thick. This bilayer membrane was subjected to a saponification treatment, thereby introducing ion exchange groups at the ends of the polymer by hydrolysis. The end groups of the C – polymer were hydrolyzed to form carboxyl groups, and the end groups of the S – polymer were hydrolyzed to form sulfo groups. The ion-exchange capacity with sulfonic acid groups was 1.0 mg-eq / g, and the ion-exchange capacity with carboxylic acid groups was 0.9 mg-eq / g.

The electrode with its inactivated surface was placed opposite the surface having carboxyl groups as ion-exchange groups, and thermocompression was performed with it, combining the ion-exchange membrane and the electrode. One surface of the electrode was open even after thermocompression, and the electrode did not spread over part of the membrane.

After that, in order to prevent the bubbles formed during electrolysis from sticking to the membrane, a mixture of zirconium oxide and a perfluorocarbon polymer into which sulfo groups were introduced was applied to both surfaces. Thereby, a membrane and electrode assembly of Comparative Example 10 was obtained.

[1325] When the force applied per unit mass · unit area (1) was measured using this membrane and electrode assembly, the electrode did not move upward because the electrode and membrane were tightly joined together by thermocompression. Then, the ion exchange membrane and the nickel plate were fixed so that they were stationary and the electrode was pulled upward with a higher force. When a force of 1.50 N / (mg · cm ² ) was reached, part of the membrane ruptured. The membrane and electrode assembly of Comparative Example 10 had a force applied per unit mass · unit area (1) of at least 1.50 N / (mg · cm ² ), and they were firmly connected.

[1326] When the evaluation of the winding around the string with a diameter of 280 mm (1) was performed, the contact area with the plastic pipe was less than 5%. Meanwhile, when evaluating the wrapping around a 280 mm diameter column (2), the electrode and membrane were 100% connected to each other, but the membrane was not wrapped around the tower in the first place. The result of evaluating the coiling around a 145 mm diameter string (3) was the same. The result showed that the integrated electrode impaired the processability of the membrane, making it difficult to wind the membrane into a roll and create folds of the membrane. Manufacturability was "3", which was problematic. Membrane damage was scored "0". In addition, when the electrolysis performance was evaluated, the electric voltage was high, the current efficiency was low, and the total concentration of salt in the caustic soda (the value converted to 50%) was increased and the electrolysis performance was degraded.

The electrode thickness was 114 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 14 µm.

When a strain test was performed on the electrode, the average of L ₁ and L ₂ was 13 mm.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0168 (kPa · s / m) at measurement condition 2.

[1327] [Comparative Example 11]

In Comparative Example 11, a 40 mesh nickel grid having a wire diameter of 150 µm, a measured thickness of 300 µm and an open porosity ratio of 58% was used as an electrode substrate for cathode electrolysis. Except for the above, a membrane and electrode assembly was prepared in the same manner as in Comparative Example 10.

When the force applied per unit mass · unit area (1) was measured using this membrane and electrode assembly, the electrode was not moved upward because the electrode and membrane were tightly bonded together by thermocompression. Then, the ion exchange membrane and the nickel plate were fixed so that they were stationary and the electrode was pulled upward with a higher force. When a force of 1.60 N / (mg · cm ² ) was reached, part of the membrane ruptured. The membrane and electrode assembly of Comparative Example 11 had a force applied per unit mass · unit area (1) of at least 1.60 N / (mg · cm ² ), and they were firmly connected.

[1328] When evaluating the wrapping around a 280 mm diameter column (1) using this membrane and electrode assembly, the contact area with the plastic pipe was less than 5%. Meanwhile, when evaluating the wrapping around a 280 mm diameter column (2), the electrode and membrane were 100% connected to each other, but the membrane was not wrapped around the tower in the first place. The result of evaluating the coiling around a 145 mm diameter string (3) was the same. The result showed that the integrated electrode impaired the processability of the membrane, making it difficult to wind the membrane into a roll and create folds of the membrane. Manufacturability was "3", which was problematic. In addition, when the electrolysis performance was evaluated, the electric voltage was high, the current efficiency was low, and the total concentration of salt in the caustic soda (the value converted to 50%) was increased and the electrolysis performance was deteriorated.

The electrode thickness was 308 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 8 µm.

When a strain test was performed on the electrode, the average of L ₁ and L ₂ was 23 mm.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0034 (kPa · s / m) at measurement condition 2.

[1329] [Comparative Example 12]

(Getting a catalyst)

An aqueous solution of metal salts was prepared by adding 0.728 g of silver nitrate (from Wako Pure Chemical Industries, Ltd.) and 1.86 g of cerium nitrate hexahydrate (from Wako Pure Chemical Industries, Ltd.) to 150 ml of pure water. An alkali solution was prepared by adding 240 g of pure water to 100 g of a 15% aqueous solution of tetramethylammonium hydroxide (Wako Pure Chemical Industries, Ltd.). While the alkali solution was stirred using a magnetic stirrer, an aqueous solution of metal salts was added dropwise thereto at a rate of 5 ml / minute using a burette. The suspension containing the formed dispersed particles of metal hydroxides was filtered with suction and then washed with water to remove the contained alkali. Then the residue was transferred into 200 ml of 2-propanol (KISHIDA CHEMICAL Co., Ltd.) and redispersed in an ultrasonic disperser (US-600T, NISSEI Corporation) for 10 minutes to obtain a homogeneous suspension.

A carbon black suspension was prepared by dispersing 0.36 g of hydrophobic carbon black (DENKA BLACK (R) AB-7 (trade name) from Denka Company Limited) and 0.84 g of hydrophobic carbon black (Ketjenblack (R) EC-600JD (trade name) from Mitsubishi Chemical Corporation) in 100 ml of 2-propanol and the mixture was dispersed in an ultrasonic disperser for 10 minutes. The metal hydroxide precursor slurry and the carbon black slurry were mixed and dispersed in an ultrasonic disperser for 10 minutes. This suspension was filtered with suction and dried at room temperature for half a day to obtain a soot containing a dispersed and fixed precursor of metal hydroxides. Then, an inert gas kiln (type VMF165, manufactured by YAMADA DENKI CO., LTD.) Was used to conduct firing under nitrogen at 400 ° C. for an hour to obtain carbon black A containing a dispersed and fixed electrode catalyst.

[1330] (Preparation of powder for the reaction layer)

To 1.6 g of carbon black A containing a dispersed and fixed electrode catalyst, 0.84 ml of the surfactant Triton (R) X-100 (trade name) from ICN Biomedicals was added, diluted to 20% by weight with pure water, and 15 ml of pure water, and the mixture was dispersed in an ultrasonic disperser for 10 minutes. To this dispersion was added 0.664 g of a polytetrafluoroethylene (PTFE) dispersion (PTFE30J (trade name) from Dupont-Mitsui Fluorochemicals Co., Ltd.). After stirring the mixture for five minutes, suction filtration was performed. In addition, the residue was dried in a dryer at 80 ° C. for an hour, and pulverization was performed using a mill to obtain a powder for the reaction layer A.

(Obtaining a powder for a gas diffusion layer)

Dispersed 20 g of hydrophobic carbon black (DENKA BLACK (R) AB-7 (trade name)), 50 ml of the surfactant Triton (R) X-100 (trade name), diluted to 20% by weight with pure water, and 360 ml clean water in an ultrasonic disperser for 10 minutes. To the resulting dispersion was added 22.32 g of PTFE dispersion. The mixture was stirred for 5 minutes and then filtered. In addition, the residue was dried in a dryer at 80 ° C. for an hour, and pulverized using a mill to obtain powder for gas diffusion layer A.

(Obtaining a gas diffusion electrode)

To 4 g of powder for gas diffusion layer A was added 8.7 ml of ethanol, and the mixture was kneaded to form a paste. This powder for the gas diffusion layer A in a paste form was formed into a sheet-like shape using a roll forming apparatus. A silver mesh (SW = 1, LW = 2, and thickness = 0.3 mm) was embedded in the sheet as a current collector, and finally molded to form a sheet having a thickness of 1.8 mm. To 1 g of powder for reaction layer A was added 2.2 ml of ethanol, and the mixture was compounded to form a paste. This reaction layer powder in pasty form was roll formed into a sheet-like shape having a thickness of 0.2 mm. In addition, two sheets, that is, a sheet obtained using the powder for the gas diffusion layer A and a sheet obtained using the powder for the reaction layer A, were laminated and formed into a sheet having a thickness of 1.8 mm using a roll former. This layered sheet was dried at room temperature overnight to remove ethanol. In addition, in order to remove the residual surfactant, the leaf was treated under pyrolysis conditions in air at 300 ° C for an hour. The sheet was wrapped with aluminum foil and hot pressed in a hot pressing machine (SA303 (trade name) from TESTER SANGYO CO,. LTD. At 360 ° C and 50 kgf / cm ² for 1 minute to obtain a gas diffusion electrode. The thickness of the gas diffusion electrode was 412 microns.

[1331] The resulting electrode was used to perform the evaluation of electrolysis performance. In a sectional structure, an electrolytic cell, a down conductor, a mat, a nickel grid as a supply conductor, an electrode, a membrane, and an anode were placed in this order from the side of the cathode chamber to form a structure with a zero gap. The results are shown in Table 2.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 19 mm.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 25.88 (kPa · s / m) under measurement condition 1.

Manufacturability was "3", which is problematic. In addition, when the electrolysis performance was evaluated, the current efficiency was low, the total salt concentration in the caustic soda was increased, and the electrolysis performance was markedly deteriorated. Membrane damage, which was rated 3, was also problematic.

[1332] These results showed that the gas diffusion electrode obtained in Comparative Example 12 had markedly deteriorated electrolysis performance. In addition, damage was observed over substantially the entire surface of the ion exchange membrane. This is believed to be due to the action of NaOH, which was formed in the electrode, accumulating at the interface between the electrode and the membrane with an increase in its concentration, due to the markedly higher ventilation resistance of the gas diffusion electrode in Comparative Example 12.

[1333] [Comparative Example 13]

Nickel wire having a measured thickness of 150 µm was used as an electrode substrate for electrolysis at the cathode. A roughening treatment was carried out on this nickel wire. It was difficult to measure the surface roughness of the nickel wire. Then, in Comparative Example 13, a nickel plate having a thickness of 1 mm was simultaneously blasted at the time of blasting, and the surface roughness of the nickel plate was taken as the surface roughness of the nickel wire. Blasting was carried out using alumina with a grain number of 320. The arithmetic average Ra of the surface roughness was 0.64 μm.

A cover fluid for use in forming an electrode catalyst was prepared according to the following procedure. A ruthenium nitrate solution having a ruthenium concentration of 100 g / L (from FURUYA METAL Co., Ltd.) and a cerium nitrate solution (from KISHIDA CHEMICAL Co., Ltd.) were mixed so that the molar ratio between ruthenium and cerium was 1 : 0.25. This mixed solution was thoroughly mixed and used as a covering liquid for the cathode.

The bath containing the above coating liquid was placed in the lowest position of the roller coater. The vat was positioned such that a coating roll obtained by winding a closed cell EPDM sponge rubber (INOAC CORPORATION, E-4088 (trade name), 10 mm thick) around a polyvinyl chloride (PVC) ) of the cylinder, was always in contact with the cover fluid. A roller for coating, around which the same EPDM was wound, was placed on its upper part, and a PVC roller was additionally placed above it. The coating liquid was applied in such a way that the electrode substrate was passed between the second coating roller and the PVC roller in the uppermost position (roller coating method). Then, after drying at 50 ° C for 10 minutes, pre-firing at 150 ° C for 3 minutes and firing at 350 ° C for 10 minutes were carried out. A series of these operations of coating, drying, pre-baking and baking were repeated until a predetermined coating value was reached. The thickness of the resulting electrode was 570 μm. The thickness of the nickel wire obtained in Comparative Example 13 was 158 µm.

[1334] The nickel wire obtained by the above method was cut into pieces with a length of 110 mm and a length of 95 mm. As shown in Figure 16, a 110 mm nickel wire and a 95 mm nickel wire were placed so that the nickel wires were vertically overlapped at the center of each of the nickel wires and connected to each other at the intersection with a cyanoacrylate superadhesive (Aron Alpha (R) from TOAGOSEI CO., LTD.) To form an electrode. The electrode was evaluated and the results are shown in Table 2.

The portion of the electrode in which the nickel wires were overlapped had the largest thickness, and the thickness of the electrode was 306 µm. The thickness of the catalytic layer was 6 μm. The open porosity ratio was 99.7%.

[1335] The mass per unit area of the electrode was 0.5 (mg / cm ² ). The forces applied per unit mass · unit area (1) and (2) were in both cases equal to or less than the lower limit of the tensile test machine. Thus, the result of evaluating the winding around a 280 mm diameter column (2) was less than 5%, and the areas where the electrode separated from the membrane were enlarged. Manufacturability was "4", which was also problematic. Membrane damage was scored "0".

When a strain test was performed on the electrode, the average of L ₁ and L ₂ was 15 mm.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.001 (kPa s / m) or less under the measurement condition 2. When the measurement was carried out under the measurement condition 2 in the SENSE mode (measuring range) of the ventilation resistance measuring device set to H (high) , the ventilation resistance was 0.0002 (kPa · s / m).

In addition, the structure shown in FIG. 17 was used to position an electrode (cathode) on a Ni-grid supply conductor, and the electrolysis performance of the electrode was evaluated by the method described in Evaluation of Electrolysis Performance (9). As a result, the voltage was high at 3.16 V.

[1336] [Comparative Example 14]

Comparative Example 14 used the electrode obtained in Comparative Example 13. As shown in FIG. 18, a 110 mm long nickel wire and a 95 mm long nickel wire were placed so that the nickel wires vertically overlapped with each other at the center of each of the nickel wires and were connected to each other at the intersection by means of a cyanoacrylate superadhesive (Aron Alpha (R), from TOAGOSEI CO., LTD.) to form an electrode. The electrode was evaluated and the results are shown in Table 2.

The portion of the electrode in which the nickel wires were overlapped had the largest thickness, and the thickness of the electrode was 306 µm. The thickness of the catalytic layer was 6 μm. The open porosity ratio was 99.4%.

The mass per unit area of the electrode was 0.9 (mg / cm ² ). The forces applied per unit mass · unit area (1) and (2) were in both cases equal to or less than the lower limit of the tensile test machine. Thus, the result of evaluating the winding around a 280 mm diameter column (2) was less than 5%, and the areas where the electrode separated from the membrane were enlarged. Manufacturability was "4", which was also problematic. Membrane damage was scored "0".

When a strain test was performed on the electrode, the average of L ₁ and L ₂ was 16 mm.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.001 (kPa s / m) or less under the measurement condition 2. When the measurement was carried out under the measurement condition 2 in the SENSE mode (measuring range) of the ventilation resistance measuring device set to H (high) , the ventilation resistance was 0.0004 (kPa · s / m).

In addition, the structure shown in FIG. 19 was used to position an electrode (cathode) on a Ni-grid supply conductor, and the electrolysis performance of the electrode was evaluated by the method described in Evaluation of Electrolysis Performance (9). As a result, the voltage was high at 3.18 V.

[1337] [Comparative Example 15]

In Comparative Example 15, the electrode obtained in Comparative Example 13 was used. As shown in FIG. 20, a 110 mm long nickel wire and a 95 mm long nickel wire were placed so that the nickel wires vertically overlapped with each other at the center of each of the nickel wires, and were connected to each other at the intersection by means of a cyanoacrylate superadhesive (Aron Alpha (R), from TOAGOSEI CO., LTD.) to form an electrode. The electrode was evaluated and the results are shown in Table 2.

The portion of the electrode in which the nickel wires were overlapped had the largest thickness, and the thickness of the electrode was 306 µm. The thickness of the catalytic layer was 6 μm. The open porosity ratio was 98.8%.

The mass per unit area of the electrode was 1.9 (mg / cm ² ). The forces applied per unit mass · unit area (1) and (2) were in both cases equal to or less than the lower limit of the tensile test machine. Thus, the result of evaluating the winding around a 280 mm diameter column (2) was less than 5%, and the areas where the electrode separated from the membrane were enlarged. Manufacturability was "4", which was also problematic. Membrane damage was scored "0".

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 14 mm.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.001 (kPa s / m) or less under the measurement condition 2. When the measurement was carried out under the measurement condition 2 in the SENSE mode (measuring range) of the ventilation resistance measuring device set to H (high) , the ventilation resistance was 0.0005 (kPa · s / m).

In addition, the structure shown in FIG. 21 was used to position an electrode (cathode) on the Ni-grid supply conductor, and the electrolysis performance of the electrode was evaluated by the method described in Evaluation of Electrolysis Performance (9). As a result, the voltage was high at 3.18 V.

[1338]

[Table 1]

Electrode support Electrode support shape Coating method Supply conductor Example 1 Ni Perforation Pyrolysis Ni-mesh Example 2 Ni Perforation Pyrolysis Ni-mesh Example 3 Ni Perforation Pyrolysis Ni-mesh Example 4 Ni Perforation Pyrolysis Ni-mesh Example 5 Ni Perforation Pyrolysis Ni-mesh Example 6 Ni Perforation Ionic deposition Ni-mesh Example 7 Ni Electroforming Pyrolysis Ni-mesh Example 8 Ni Electroforming Pyrolysis Ni-mesh Example 9 Ni Non-woven fabric Pyrolysis Ni-mesh Example 10 Ni Non-woven fabric Pyrolysis Ni-mesh Example 11 Ni Porous Ni Pyrolysis Ni-mesh Example 12 Ni Grid Pyrolysis Ni-mesh Example 13 Ni Grid Pyrolysis Ni-mesh Example 14 Ni Perforation (same as example 3) Pyrolysis Mat Example 15 Ni Perforation (same as example 3) Pyrolysis Overvoltage cathode Example 16 Ti Perforation Pyrolysis Overvoltage anode Example 17 Ti Perforation Pyrolysis Overvoltage anode Example 18 Ti Perforation Pyrolysis Overvoltage anode Example 19 Ti Perforation Pyrolysis Overvoltage anode Example 20 Ti Non-woven fabric Pyrolysis Overvoltage anode Example 21 Ti Grid Pyrolysis Overvoltage anode Example 22 Ni / Ti Combination of Example 3 and Example 20 Pyrolysis Overvoltage cathode and anode Example 23 Ni Perforation Pyrolysis - Example 24 Carbon Woven fabric Pyrolysis Ni-mesh Comparative Example 1 Ni Expanded metal Pyrolysis Ni-mesh Comparative Example 2 Ni Expanded metal Pyrolysis Ni-mesh Comparative Example 3 Ni Expanded metal Ionic deposition Ni-mesh Comparative Example 4 Ni Expanded metal Pyrolysis Ni-mesh Comparative Example 5 Ni Grid Pyrolysis Ni-mesh Comparative Example 6 Ni Grid Pyrolysis Ni-mesh Comparative Example 7 Ti Expanded metal Pyrolysis Overvoltage anode Comparative Example 8 Ti Expanded metal Pyrolysis Overvoltage anode Comparative Example 9 Ti Expanded metal Pyrolysis Overvoltage anode Comparative Example 10 Ni Expanded metal Pyrolysis Ni-mesh Comparative Example 11 Ni Grid Pyrolysis Ni-mesh Comparative Example 12 Carbon Powder Pyrolysis Ni-mesh Comparative Example 13 Ni Grid Pyrolysis Ni-mesh Comparative Example 14 Ni Grid Pyrolysis Ni-mesh Comparative Example 15 Ni Grid Pyrolysis Ni-mesh

[1339]

[1340] In Table 2, all specimens were able to hold on their own due to surface tension before measuring “force applied per unit mass · unit area (1)” and “force applied per unit mass · unit area (2)” (that is, do not slide down).

[1341] In Comparative Examples 1, 2, 7-9, since the mass per unit area was large and the force applied per unit mass · unit area (1) was small, the adhesion strength to the membrane was poor. Thus, with a large electrolytic cell (for example, 1.5 m long and 3 m wide), the membrane, which is a polymer membrane, can inevitably sag during operation. At this time, the electrode is detached, and thus the samples do not withstand the conditions of practical use.

[1342] In Comparative Examples 3 and 4, since the force applied per unit mass · unit area (1) was small, the adhesion strength to the membrane was poor. Thus, with a large electrolytic cell (for example, 1.5 m long and 3 m wide), the membrane, which is a polymer membrane, can inevitably sag during operation. At this time, the electrode is detached, and thus the samples do not withstand the conditions of practical use.

[1343] In Comparative Examples 5 and 6, the mass per unit area was large, and the adhesion strength to the membrane was poor. Thus, with a large electrolytic cell (for example, 1.5 m long and 3 m wide), the membrane, which is a polymer membrane, can inevitably sag during operation. In this case, the electrode is detached, and thus the samples do not withstand the conditions of practical use.

[1344] In Comparative Examples 10 and 11, since the membrane and electrode were firmly bonded by thermal compression, the electrode did not separate from the membrane during use, like Comparative Examples 1, 2, 7-9. However, due to the strong connection to the electrode, the polymer membrane sharpened flexibility. This made it difficult to roll the samples into a roll and fold the samples. The samples have poor manufacturability and do not withstand the conditions of practical use.

[1345] In addition, in Comparative Examples 10 and 11, the electrolysis performance was significantly degraded. Probably, the voltage noticeably increases, since the ion flow is suppressed by the fact that the electrodes become recessed into the ion-exchange membrane. Regarding the reason for the decrease in current efficiency and the deterioration of the total salt concentration in the caustic soda, possible factors included high current efficiency, uneven thickness of the carboxylic acid layer due to immersion of the electrode in the carboxylic acid layer, the effect of ion selectivity and the penetration of the electrode embedded in part of the layer carboxylic acid.

[1346] In addition, in Comparative Examples 10 and 11, in the case where there was a problem with either the membrane or the electrode, and replacement was required, it was not possible to replace one element of the membrane and the electrode due to their strong connection, which led to increased costs.

[1347] In Comparative Example 12, electrolysis performance was significantly degraded. It is likely that the voltage rises markedly due to the product heating up at the interface between the membrane and the electrode.

[1348] In Comparative Examples 13-15, both forces applied per unit mass · unit area (1) and (2) were small (equal to or less than the lower measurement limit), and thus the adhesion strength to the membrane was poor. Thus, with a large electrolytic cell (for example, 1.5 m long and 3 m wide), the membrane, which is a polymer membrane, can inevitably sag during operation. At this time, the electrode is detached, and thus the samples do not withstand the conditions of practical use.

[1349] In the present embodiment, the membrane and the electrode are in close contact with each other on each surface with moderate force, and thus there is no problem such as the electrode detachment during use. The ion flow in the membrane is not suppressed, and thus good electrolysis performance is manifested.

[1350] <Checking second embodiment>

As will be described below, Experimental Examples according to the second embodiment are presented (in the section <Verification of the second embodiment>, below, simply referred to as “Examples”) and Experimental Examples not corresponding to the second embodiment (in the section <Verification of the second embodiment>, hereinafter simply referred to as "Comparative Examples"), and evaluated by the following method. Details will be described with reference to Figures 31-42 as appropriate.

[1351] [Evaluation Method]

(1) Coefficient of open porosity

The electrode was cut into fragments of 130 mm × 100 mm. A digital thickness gauge (Mitutoyo Corporation, minimum scale 0.001 mm) was used to calculate the average of 10 points measured uniformly over the plane. The value was used as the thickness of the electrode (measured thickness) to calculate the volume. Thereafter, an electronic balance was used to measure the mass. From the specific gravity of each metal (specific gravity of nickel = 8.908 g / cm ³ , specific gravity of titanium = 4.506 g / cm ³ ), the coefficient of open porosity or the coefficient of voidness was calculated.

[1352] Open porosity ratio (void ratio) (%) = (1– (electrode mass) / (electrode volume × specific gravity of metal)) × 100

[1353] (2) Mass per unit area (mg / cm ² )

The electrode was cut into pieces of 130 mm × 100 mm and its mass was measured on an electronic balance. The value was divided by the area (130 mm x 100 mm) to calculate the mass per unit area.

[1354] (3) Force applied per unit mass · unit area (1) (adhesion force) (N / (mg · cm ² ))

[Method (i)]

For measurement, a tensile and compression machine (manufactured by Imada-SS Corporation, main testing machine: tensile and compression testing machine SDT-52NA type, load cell: load cell type SL-6001) was used.

[1355] A 200 mm square nickel plate having a thickness of 1.2 mm was blasted with 320 grit alumina. The arithmetic average (Ra) of the surface roughness of the nickel plate after blasting was 0.7 µm. Here, to measure the surface roughness, an SJ-310 probe-type surface roughness meter (profilometer) (Mitutoyo Corporation) was used. The sample to be measured was placed on the plate surface parallel to the ground surface to measure the arithmetic mean of the roughness Ra under the conditions described below. The measurement was repeated 6 times, and the average was deduced.

[1356] <Probe shape> apex taper angle = 60 °, tip radius = 2 µm, static measuring force = 0.75 mN.

<Roughness Standard> JIS2001

<Evaluation curve> R

<Filter> GAUSS

<Limit value λc> 0.8 mm

<Limit value λs> 2.5 µm

<Number of sections> 5

<Pre-pass, additional pass> available

This nickel plate was mounted vertically on the bottom grip of a tensile and compression machine.

[1357] The membrane used was the following ion-exchange membrane A.

Monofilaments with a size of 90 denier made of polytetrafluoroethylene (PTFE) (hereinafter referred to as PTFE yarns) were used as reinforcing materials of the core. The consumable yarns were yarns obtained by twisting 200 times / meter of six 35 denier polyethylene terephthalate (PET) filaments (hereinafter referred to as PET yarns). First, in each of the TD- and MD-directions, plain weaving of PTFE-yarns and consumable yarns with 24 PTFE-yarns / inch was performed so that two consumable yarns were placed between adjacent PTFE-yarns to obtain a woven fabric. The resulting woven fabric was subjected to roller compaction to obtain a woven fabric having a thickness of 70 µm.

Then resin A was obtained in the form of a dry resin, which was a copolymer of CF ₂ = CF ₂ and CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ COOCH ₃ and had an ion exchange capacity of 0.85 mg-eq / g, and the resin B in the form of a dry resin, which was a copolymer of CF ₂ = CF ₂ and CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₂ F and had an ion exchange capacity of 1.03 mg⋅eq / g.

Using these resins A and B, a two-layer film X in which the thickness of the resin layer A was 15 µm and the thickness of the resin layer B was 104 µm was obtained by a flat die coextrusion method.

Then release paper (having embossing with a conical shape with a height of 50 μm), reinforcing material and film X were laminated in this order on a hot plate having a heat source and a vacuum source inside and having micropores on its surface, heated and depressurized under surface temperature conditions hot plate 223 ° C and a reduced pressure value of 0.067 MPa for 2 minutes, and then remove the release paper to obtain a composite membrane.

The resulting composite membrane was immersed in an aqueous solution heated to 80 ° C. containing 30% by weight of dimethyl sulfoxide (DMSO) and 15% by weight of potassium hydroxide (KOH) for 20 minutes for saponification. Then the composite membrane was immersed in an aqueous 0.5N hydrochloric acid heated to 50 ° C. sodium hydroxide solution (NaOH) for one hour to replace the counterion of the ion exchange group with Na, and then washed with water. Then the membrane was dried at 60 ° C.

In addition, 20% by mass of zirconium oxide having a primary particle size of 1 μm was added to an ethanol solution with a concentration of 5% by mass of resin B as an acid-type resin, and dispersed to obtain a slurry, and the slurry was sprayed onto both surfaces of the above composite membranes by spraying a suspension with the formation of coatings of zirconium oxide on the surfaces of the composite membrane to obtain ion-exchange membrane A. The density of the coating of zirconium oxide, measured by X-ray fluorescence analysis, was 0.5 mg / cm ² . The average particle size was measured with a particle size analyzer (manufactured by SHIMADZU CORPORATION, "SALD (R) 2200").

The obtained above ion exchange membrane (membrane) was immersed in pure water for 12 hours or more, and then used for testing. The membrane was brought into contact with the aforementioned nickel plate completely moistened with pure water and adhered by the surface tension of the water. At this time, the nickel plate and the ion exchange membrane were positioned so that their upper ends coincided.

[1358] A sample of an electrolysis electrode (electrode) used for measurement was cut to form a piece in the form of a square with a side of 130 mm. Ion exchange membrane A was cut to form a 170 mm square fragment. One side of the electrode was sandwiched between two stainless steel plates (thickness: 1 mm, length: 9 mm, width: 170 mm). After positioning so that the center of the stainless steel plates was aligned with the center of the electrode, four clamps were used to evenly secure the electrode and the plates. The stainless steel plates in the center were clamped by the upper clamp of the tensile and compression machine while the electrode was suspended. The load applied by the testing machine at this time was set to 0 N. The combined assembly of stainless steel plates, electrode, and clamps was temporarily removed from the tensile and compressive testing machine and immersed in a bath containing clean water to sufficiently moisten electrode with clean water. Thereafter, the stainless steel plates in the center were again clamped with the upper clamp of the tensile and compression machine while the electrode was suspended.

The upper clamp of the tensile and compressive testing machine was lowered and the sample of the electrolysis electrode was adhered to the surface of the ion exchange membrane by the surface tension of pure water. The size of the engagement surface at this time was 130 mm long and 110 mm wide. The entire electrode and the ion-exchange membrane were sprayed with clean water from a wash bottle in order to sufficiently moisten the membrane and electrode again. Thereafter, a roll formed by winding a 5 mm thick EPDM sponge rubber around a vinyl chloride pipe (outer diameter: 38 mm) was rolled from top to bottom while lightly pressing against the electrode to remove excess pure water. Rolling was carried out only once.

[1359] The electrode was lifted at a speed of 10 mm / minute to start measuring the load, and the load was recorded when the size of the overlapping area of the electrode and membrane reached 130 mm in width and 100 mm in length. This measurement was repeated three times and the average was calculated.

This average value was divided by the area of the overlapping area of the electrode and ion-exchange membrane and by the mass of the electrode in the overlap area with the ion-exchange membrane to calculate the force applied per unit mass · unit area (1). The mass of the electrode in the overlapping portion with the ion exchange membrane was determined by proportional division from the value obtained in the above section (2) Mass per unit area (mg / cm ² ).

With regard to the environment in the measurement chamber, the temperature was 23 ± 2 ° C and the relative humidity was 30 ± 5%.

The electrode used in the Examples and Comparative Examples was able to hold on its own and adhere without sliding down or peeling when it was adhered to an ion exchange membrane that was adhered to a vertically fixed nickel plate under surface tension.

A schematic view of the method for evaluating the applied force (1) is shown in FIG. 31.

The lower limit of the tensile testing machine was 0.01 (N).

[1360] (4) Force applied per unit mass · unit area (2) N / (mg · cm ² ) (adhesion force)

[Method (ii)]

For measurement, a tensile and compression machine (manufactured by Imada-SS Corporation, main testing machine: tensile and compression testing machine SDT-52NA type, load cell: load cell type SL-6001) was used.

A nickel plate, identical to the one in Method (i), was mounted vertically on the bottom clamp of a tensile and compression machine.

A sample of the electrolysis electrode (electrode) used for measurement was cut to form a piece in the form of a square with a side of 130 mm. Ion exchange membrane A was cut to form a 170 mm square fragment. One side of the electrode was sandwiched between two stainless steel plates (thickness: 1 mm, length: 9 mm, width: 170 mm). After positioning so that the center of the stainless steel plates was aligned with the center of the electrode, four clamps were used to evenly secure the electrode and the plates. The stainless steel plates in the center were clamped by the upper clamp of the tensile and compression machine while the electrode was suspended. The load applied by the testing machine at this time was set to 0 N. The combined assembly of stainless steel plates, electrode, and clamps was temporarily removed from the tensile and compressive testing machine and immersed in a bath containing clean water to sufficiently moisten electrode with clean water. Thereafter, the stainless steel plates in the center were again clamped with the upper clamp of the tensile and compression machine while the electrode was suspended.

[1361] The upper clamp of the tensile and compression machine was lowered and the electrolysis electrode sample adhered to the surface of the nickel plate by the surface tension of the solution. The size of the engagement surface at this time was 130 mm long and 110 mm wide. The entire electrode and the nickel plate were sprayed with clean water from a wash bottle to sufficiently wet the nickel plate and electrode again. Thereafter, a roll formed by winding a 5 mm thick EPDM spongy rubber around a vinyl chloride tube (outer diameter: 38 mm) was rolled from top to bottom while lightly pressing against the electrode to remove excess solution. Rolling was carried out only once.

The electrode was lifted at a speed of 10 mm / minute to start measuring the load, and the load was recorded when the size of the overlapping area of the electrode and the nickel plate in the longitudinal direction reached 100 mm. This measurement was repeated three times and the average was calculated.

This average value was divided by the area of the overlapping area of the electrode and the nickel plate and by the unit mass of the electrode in the overlapping area with the nickel plate to calculate the force applied per unit mass · unit area (2). The mass of the electrode in the membrane overlap portion was determined by proportional division from the value obtained in the above section (2) Mass per unit area (mg / cm ² ).

With regard to the environment in the measurement chamber, the temperature was 23 ± 2 ° C and the relative humidity was 30 ± 5%.

The electrode used in the Examples and Comparative Examples was capable of self-adhesion and adhesion without sliding down or peeling when adhered to the vertically supported nickel plate under surface tension.

The lower limit of the tensile testing machine was 0.01 (N).

[1362] (5) Method for evaluating the winding around a string with a diameter of 280 mm (1) (%)

(Membrane and Column)

Evaluation method (1) was carried out according to the following procedure.

The ion exchange membrane A (membrane) obtained in [Method (i)] was cut to form a 170 mm square piece. The ion exchange membrane was immersed in pure water for 12 hours or more and then used for testing. In Comparative Examples 1 and 2, the electrode was hot-pressed with the ion exchange membrane, and thereby a combined unit of the ion exchange membrane and electrode (130 mm square electrode) was obtained. After the ion exchange membrane was completely immersed in pure water, the membrane was placed on the curved surface of a plastic (polyethylene) pipe having an outer diameter of 280 mm. Thereafter, the excess solution was removed with a roller formed by winding a 5 mm thick EPDM sponge rubber around a vinyl chloride pipe (outer diameter: 38 mm). The roll was rolled over the ion exchange membrane from left to right in the schematic view shown in FIG. 32. The roll was carried out only once. One minute thereafter, the proportion of the portion where the ion exchange membrane came into intimate contact with the plastic electrode tube having an outer diameter of 280 mm was measured.

[1363] (6) Method for evaluating the winding around a string with a diameter of 280 mm (2) (%)

(Membrane and electrode)

Evaluation method (2) was carried out according to the following procedure.

The ion exchange membrane A (membrane) obtained in [Method (i)] was cut to form a 170 mm square fragment, and the electrode was cut to form a 130 mm square fragment. The ion exchange membrane was immersed in pure water for 12 hours or more and then used for testing. The ion exchange membrane and electrode were completely immersed in pure water and then layered. This layered product was placed on the curved surface of a plastic (polyethylene) pipe having an outer diameter of 280 mm with the electrode on the outside. Thereafter, a roll formed by winding a spongy EPDM rubber of a closed cell type having a thickness of 5 mm around a vinyl chloride tube (outer diameter: 38 mm) was rolled over the ion exchange membrane from left to right in the schematic view shown in FIG. 33 while lightly pressing the electrode to remove excess solution. Rolling was carried out only once. One minute thereafter, the proportion of the area where the ion exchange membrane was brought into close contact with the electrode was measured.

[1364] (7) Method for evaluating the winding around a string with a diameter of 145 mm (3) (%)

(Membrane and electrode)

Evaluation method (3) was carried out according to the following procedure.

The ion exchange membrane A (membrane) obtained in [Method (i)] was cut to form a 170 mm square fragment, and the electrode was cut to form a 130 mm square fragment. The ion exchange membrane was immersed in pure water for 12 hours or more and then used for testing. The ion exchange membrane and electrode were completely immersed in pure water and then layered. This laminate was placed on the curved surface of a plastic (polyethylene) pipe having an outer diameter of 145 mm with the electrode on the outside. Thereafter, a roll formed by winding a 5 mm thick EPDM sponge rubber around a vinyl chloride tube (outer diameter: 38 mm) was rolled from left to right in the schematic view shown in FIG. 34 while lightly pressing the electrode to remove excess solution. Rolling was carried out only once. One minute thereafter, the proportion of the area where the ion exchange membrane was brought into close contact with the electrode was measured.

[1365] (8) Manufacturability (reaction assessment)

(A) The ion exchange membrane A (membrane) obtained in [Method (i)] was cut to form a 170 mm square piece, and the electrode was cut into pieces of 95 × 110 mm. The ion exchange membrane was immersed in pure water for 12 hours or more and then used for testing. In each Example, the ion-exchange membrane and the electrode were completely immersed in three solutions: aqueous sodium bicarbonate solution, aqueous 0.1 N. NaOH solution, and pure water, then layered and placed stationary on a Teflon plate. The spacing between the anode cell and the cathode cell used in the electrolysis evaluation was adjusted to about 3 cm. The stationary layered article was lifted and the operation of inserting and holding the layered article between them was carried out. This operation was performed by checking the electrode for displacement and drop.

[1366] (B) The ion exchange membrane A (membrane) obtained in [Method (i)] was cut to form a 170 mm square piece, and the electrode was cut into pieces of 95 × 110 mm. The ion exchange membrane was immersed in pure water for 12 hours or more and then used for testing. In each Example, the ion-exchange membrane and the electrode were completely immersed in three solutions: aqueous sodium bicarbonate solution, aqueous 0.1 N. NaOH solution, and pure water, then layered and placed stationary on a Teflon plate. Two adjacent corners of a portion of the membrane in the laminate were hand held to lift the laminate so that it is vertical. The membrane, held by hands at two adjacent corners, was moved from this state, bringing them close to each other so that the membrane protruded or recessed. This movement was repeated again to check the adherence of the electrode to the membrane. The results were evaluated on a four-point scale from 1 to 4 based on the following indicators:

1: good workability

2: usable

3: operation is difficult

4: essentially unserviceable

Here, a sample of Comparative Example 2-5 formed with a size equivalent to that of a large electrolytic cell including a 1.3 m × 2.5 m electrode and a 1.5 m × 2.8 m ion exchange membrane was handled ... The evaluation result of Comparative Example 5 ("3" as described below) was used as an index to evaluate the difference between the evaluation of the above (A) and (B) and the evaluation of a large sample. That is, in the case where the evaluation result of the small-sized laminate was "1" or "2", it was judged that no workability problems arise even if the laminate was formed at a large size.

[1367] (9) Evaluation of electrolysis characteristics (voltage (V), current efficiency (%), the total salt concentration of the caustic soda (mn ^-1, 50% based))

The electrolysis performance was evaluated in the following electrolysis experiment.

A titanium anode cell was placed opposite each other, having an anode chamber in which the anode (anode outlet cell) was formed, and a cathode cell having a nickel cathode chamber, in which a cathode (cathode outlet cell) was formed. A pair of seals was placed between the cells, and a layered article (a layered article of ion exchange membrane A and an electrolysis electrode) was placed between the seal and. Then, the anode cell, seal, laminate, seal, and cathode were brought into intimate contact with each other to form an electrolytic cell, and an electrolyzer containing the cell was formed.

[1368] The anode was obtained by applying a mixed solution of ruthenium chloride, iridium chloride and titanium tetrachloride on a titanium substrate, subjected to blasting and acid etching as a pretreatment, followed by drying and firing. The anode was fixed in the anode chamber by welding. As the cathode, the cathode described in each of Examples and Comparative Examples was used. A nickel expanded metal sheet was used as a current collector of the cathode chamber. The down conductor was 95 mm long × 110 mm wide. As the metal elastic body, a mat formed by knitting a thin nickel wire was used. The mat as a metal elastic body was placed on the down conductor. A nickel mesh was placed on top of it, formed by a plain weave of nickel wire having a diameter of 150 μm and a mesh size of 40 mesh, and a Teflon (R) cord made of Teflon (R) was used to fix the four corners of the Ni – mesh to the down conductor. This Ni-grid was used as a supply conductor. This electrolytic cell has a zero-gap design utilizing the repulsive force generated by the mat like a metal resilient body. Seals made of ethylene-propylene-diene rubber (EPDM) were used as seals. The membrane used was an ion exchange membrane A (square with a side of 160 mm) obtained in [Method (i)].

[1369] The above electrolytic cell was used to perform conventional salt electrolysis. The brine concentration (sodium chloride concentration) in the anode chamber was adjusted to 205 g / L. The concentration of sodium hydroxide in the cathode compartment was set to 32% by weight. The temperature of each of the anode chamber and the cathode chamber was adjusted so that the temperature in each chamber could reach 90 ° C. Conventional salt electrolysis was carried out at a current density of 6 kA / m ² , measuring voltage, current efficiency and total salt concentration in caustic soda. The current efficiency here is the ratio of the amount of caustic soda formed to the passed current, and when impurity ions and hydroxide ions, rather than sodium ions, pass through the ion exchange membrane under the influence of the passed current, the current efficiency decreases. The current efficiency was obtained by dividing the number of moles of caustic soda formed during a given time by the number of moles of electrons of current passed during that time. The number of moles of caustic soda was obtained by separating the caustic soda formed during electrolysis into a plastic container and measuring its weight. Shown as the total salt concentration in caustic soda is the value obtained by converting the caustic soda concentration by 50%.

The technical characteristics of the electrode and supply conductor used in each of the Examples and Comparative Examples are shown in Table 3.

[1370]

(11) Measurement of the thickness of the catalytic layer, the electrode substrate for electrolysis and the thickness of the electrode

A digital thickness gauge (manufactured by Mitutoyo Corporation, minimum scale 0.001 mm) was used to measure the thickness of the electrolysis electrode substrate by calculating an average of 10 points measured uniformly over the plane. This value was used as the thickness of the electrode substrate for electrolysis (measured thickness). A digital thickness gauge was used to measure the electrode thickness, calculating the average of 10 points, obtained by measuring uniformly over the plane, in the same way as for the electrode substrate. This value was used as the thickness of the electrode (measured thickness). The thickness of the catalytic layer was determined by subtracting the thickness of the electrolysis electrode substrate from the thickness of the electrode.

[1371] (12) Test of elastic deformation of the electrode

Each of the ion exchange membrane A (membrane) and the electrode obtained in [Method (i)] was cut to obtain a 110 mm square sample. The ion exchange membrane was immersed in pure water for 12 hours or more and then used for testing. Thereafter, the ion-exchange membrane and electrode were layered to obtain a laminated product under conditions of temperature: 23 ± 2 ° C and relative humidity: 30 ± 5%, the laminated product was wound around a PVC pipe having an outer diameter of φ32 mm and a length of 20 cm, without any or a gap as shown in Figure 35. The laminated product was secured using a polyethylene cable tie so that the laminated product could not separate from the PVC pipe or loosen. The laminated article was held in this state for 6 hours. After that, the cable tie was removed and the laminated product was unwound from the PVC pipe. Only the electrode was placed on the surface plate and the heights L ₁ and L _{2 of the} portion raised from the surface plate were measured to determine the average. This value was used as an indicator of electrode deformation. That is, a lower value means that the laminate is less likely to deform.

When expanded metal sheet was used, there were two winding directions: SW-direction and LW-direction. In this test, the laminate was wound in the SW direction.

Deformed electrodes (electrodes that did not return to their original state) were evaluated for softness after plastic deformation according to the method as shown in Figure 36. That is, the deformed electrodes were placed on a membrane completely immersed in pure water. One end of the electrode was fixed and the other raised end was pressed against the membrane to relieve the force, and it was judged whether the deformed electrode was in contact with the membrane.

[1372] (13) Assessment of membrane damage

The following ion exchange membrane B was used as a membrane.

As the reinforcing materials of the core, materials obtained by twisting 900 times / meter of 100 denier polytetrafluoroethylene (PTFE) filaments in the form of filaments (hereinafter referred to as PTFE yarns) were used. As the warp yarns consumable, yarns obtained by twisting 200 times / meter of eight 35 denier polyethylene terephthalate (PET) filaments (hereinafter referred to as PET yarns) were used. As the weft consumable yarns, yarns obtained by twisting 200 times / meter of eight 35 denier polyethylene terephthalate (PET) filaments were used. First, plain weaving of PTFE yarns and consumable yarns was performed with 24 PTFE yarns / inch so that two consumable yarns were placed between adjacent PTFE yarns, resulting in a woven fabric having a thickness of 100 µm.

Then, polymer (A1) was obtained in the form of a dry resin, which was a copolymer of CF ₂ = CF ₂ and CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ COOCH ₃ and had an ion exchange capacity of 0.92 mg⋅eq / g, and polymer (B1) in the form of a dry resin, which was a copolymer of CF ₂ = CF ₂ and CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₂ F and had an ion exchange capacity of 1.10 mg⋅eq / g. Using these polymers (A1) and (B1), a two-layer film X in which the thickness of the polymer layer (A1) was 25 µm and the thickness of the polymer layer (B1) was 89 µm was obtained by a flat die coextrusion method. As the ion exchange capacity of each polymer, the ion exchange capacity was shown in the case of hydrolysis of the precursors of the ion exchange groups of each polymer for conversion to ion exchange groups.

Separately, polymer (B2) was obtained in the form of a dry resin, which was a copolymer of CF ₂ = CF ₂ and CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₂ F and had an ion exchange capacity of 1.10 mg-eq / g ... This polymer was obtained by single layer extrusion to obtain a Y film having a thickness of 20 μm.

Then release paper, film Y, reinforcing material and film X were laminated in this order on a hot plate having a heat source and a vacuum source inside and having micropores on its surface, heated and depressurized under conditions of a hot plate surface temperature of 225 ° C and a value of reduced pressure of 0.022 MPa for two minutes, and then the release paper was removed to obtain a composite membrane. The resulting composite membrane was immersed in an aqueous solution containing dimethyl sulfoxide (DMSO) and potassium hydroxide (KOH) for one hour to saponify. After that, the membrane was immersed in aqueous 0.5N hydrochloric acid. NaOH solution for one hour to replace the ions attached to the ion-exchange groups with Na, and then washed with water. Then the membrane was dried at 60 ° C.

In addition, polymer (B3) was hydrolyzed in the form of a dry resin, which was a copolymer of CF ₂ = CF ₂ and CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₂ F and had an ion exchange capacity of 1.05 mg-eq. / g, and then converted into an acid-type polymer with hydrochloric acid. Zirconium oxide particles having an average primary particle size of 0.02 μm were added to a mixed 50/50 (mass ratio) solution of water and ethanol in which polymer (B3 ') of this acidic type was dissolved in a proportion of 5% by mass so that the mass the ratio of polymer (B3 ') to zirconium oxide particles was 20/80. Thereafter, the polymer (B3 ') was dispersed in a slurry of zirconium oxide particles with a ball mill to obtain a slurry.

This suspension was sprayed onto both surfaces of an ion exchange membrane and dried to obtain an ion exchange membrane B having a coating layer containing polymer (B3 ') and zirconium oxide particles. The density of the zirconium oxide coating, measured by X-ray fluorescence analysis, was 0.35 mg / cm ² .

[1373] The anode used was the same as in section (9) Evaluation of electrolysis performance.

The cathode used was the cathode described in each of the Examples and Comparative Examples. The down conductor, mat and supply conductor of the cathode chamber used were the same as in section (9) Evaluation of electrolysis performance. That is, a zero-gap design was provided, using the Ni-grid as the supply conductor and the repulsive force that the mat creates as a metallic elastic body. The seals used were the same as in section (9) Evaluation of electrolysis performance. As the membrane, the ion-exchange membrane B obtained by the above method was used. That is, an electrolyzer equivalent to that shown in section (9) was formed, except that the laminated article of the ion exchange membrane B and the electrolysis electrode was interposed between the pair of seals.

[1374] The above electrolytic cell was used to perform ordinary salt electrolysis. The brine concentration (sodium chloride concentration) in the anode chamber was adjusted to 205 g / L. The concentration of sodium hydroxide in the cathode compartment was set to 32% by weight. The temperature of each of the anode chamber and the cathode chamber was adjusted so that the temperature in each chamber could reach 70 ° C. The electrolysis of common salt was carried out at a current density of 8 kA / m ² . The electrolysis was stopped 12 hours after the start of the electrolysis, and the ion exchange membrane B was removed and examined to assess the state of its damage.

"0" means no damage. A score of "1" to "3" means there is damage, and a higher number means a high degree of damage.

[1375] (14) Ventilation resistance of the electrode

The ventilation resistance of the electrode was measured using a KES-F8 air permeability tester (trade name, KATO TECH CO., LTD.). The unit for ventilation resistance is kPa s / m. The measurement was repeated 5 times, and the average value is shown in Table 4. The measurement was carried out under the following conditions. The temperature of the measuring chamber was 24 ° C and the relative humidity was 32%.

Measurement condition 1 (ventilation resistance 1)

Piston speed: 0.2 cm / s

Purge volume: 0.4 cm ³ / cm ² / s

Measuring range: SENSE L (low)

Sample size: 50mm × 50mm

Measurement condition 2 (ventilation resistance 2)

Piston speed: 2 cm / s

Purge volume: 4 cm ³ / cm ² / s

Measuring range: SENSE M (medium) or H (high)

Sample size: 50mm × 50mm

[1376]

[Example 2-1]

As an electrode substrate for a cathode in electrolysis, an electrolytic nickel foil having a measured thickness of 16 µm was obtained. One surface of this nickel foil was roughened by electrolytic nickel plating. The arithmetic mean Ra of the roughness of the rough surface was 0.71 μm. The surface roughness measurement was performed under the same conditions as in the case of the surface roughness measurement of the blasted nickel plate.

A porous foil was formed by punching this nickel foil into circular holes by punching. The open porosity ratio was 49%.

[1377] A cover fluid for use in forming an electrode catalyst was prepared according to the following procedure. Solutions of ruthenium nitrate having a ruthenium concentration of 100 g / L (from FURUYA METAL Co., Ltd.) and cerium nitrate (from KISHIDA CHEMICAL Co., Ltd.) were mixed so that the molar ratio between ruthenium and cerium was 1: 0.25. This mixed solution was thoroughly mixed and used as a covering liquid for the cathode.

The bath containing the above coating liquid was placed in the lowest position of the roller coater. The vat was positioned such that a coating roll obtained by winding a closed cell type EPDM sponge rubber (INOAC CORPORATION, E-4088, 10 mm thick) around a polyvinyl chloride (PVC) cylinder was always in contact with the casing fluid. A roller for coating, around which the same EPDM was wound, was placed on its upper part, and a PVC roller was additionally placed above it. The coating liquid was applied in such a way that the electrode substrate was passed between the second coating roller and the PVC roller in the uppermost position (roller coating method). Then, after drying at 50 ° C for 10 minutes, pre-firing at 150 ° C for 3 minutes and firing at 350 ° C for 10 minutes were carried out. A series of these operations of coating, drying, pre-baking and baking were repeated until a predetermined coating value was reached. The thickness of the electrode made in Example 2-1 was 24 µm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 8 µm. A coating was also formed on a surface that was not roughened. The thickness was the combined thickness of ruthenium oxide and cerium oxide.

The results of measuring the adhesion force of the electrode made by the above method are shown in Table 4. Sufficient adhesion force was observed.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 0 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less under measurement condition 1 and 0.0028 (kPa · s / m) under measurement condition 2.

[1378] The electrode obtained by the above method was cut into pieces of 95 mm in length and 110 mm in width to evaluate the performance of electrolysis. The roughened electrode surface was placed opposite the substantially central position of the side of the carboxylic acid layer of the ion exchange membrane A (size: 160 mm × 160 mm) obtained in [Method (i)] and equilibrated with aqueous 0.1N. NaOH solution, and ensured adhesion to it under the action of the surface tension of the aqueous solution.

Even when the four corners of the membrane-integrated electrode portion, which was obtained by combining the membrane with the electrode, were clamped and suspended so that the membrane-integrated electrode was parallel to the base so that the electrode was facing toward the base, the electrode did not detach or move. In addition, when both ends of one side were clamped and suspended so that the membrane-integrated electrode was perpendicular to the base, the electrode did not detach or move.

The above membrane-integrated electrode was interposed between the anode cell and the cathode cell so that the surface to which the electrode was attached was facing the cathode chamber side. In a sectional structure, a down conductor, a mat, a nickel mesh as a supply conductor, an electrode, a membrane, and an anode were placed in this order from the side of the cathode chamber to form a structure with a zero gap.

The resulting electrode was tested for electrolysis performance. The results are shown in Table 4.

The electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0".

When the amount of coating after electrolysis was measured by X-ray fluorescence analysis (XRF), substantially 100% of the coating remained on the surface that had been roughened, and the coating on the surface that had not been roughened was reduced. This shows that the surface opposite to the membrane (roughened surface) is involved in electrolysis, and other surfaces not opposite the membrane can achieve satisfactory electrolysis performance when the amount of coverage is small or no coating.

[1379] [Example 2-2]

In Example 2-2, an electrolytic nickel foil having a measured thickness of 22 μm was used as an electrode substrate for electrolysis at the cathode. One surface of this nickel foil was roughened by an electrolytic nickel plating process. The arithmetic average Ra of the roughness of the rough surface was 0.96 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. The open porosity ratio was 44%. Except as described above, the evaluation was performed in the same manner as in Example 2-1, and the results are shown in Table 4.

The electrode thickness was 29 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 7 µm. The coating was also formed on a surface that was not roughened.

Sufficient traction was observed.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 0 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less under measurement condition 1 and 0.0033 (kPa · s / m) under measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0".

When the amount of coating after electrolysis was measured by XRF, substantially 100% of the coating remained on the surface that had been roughened, and the coating on the surface that had not been roughened was reduced. This shows that the surface opposite to the membrane (roughened surface) is involved in electrolysis, and other surfaces not opposite the membrane can achieve satisfactory electrolysis performance when the amount of coverage is small or no coating.

[1380] [Example 2-3]

In Example 2-3, an electrolytic nickel foil having a measured thickness of 30 μm was used as an electrode substrate for electrolysis at the cathode. One surface of this nickel foil was roughened by an electrolytic nickel plating process. The arithmetic mean Ra of the roughness of the rough surface was 1.38 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. The open porosity ratio was 44%. Except as described above, the evaluation was performed in the same manner as in Example 2-1, and the results are shown in Table 4.

The electrode thickness was 38 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 8 µm. The coating was also formed on a surface that was not roughened.

Sufficient traction was observed.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 0 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less under measurement condition 1 and 0.0027 (kPa · s / m) under measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0".

When the amount of coating after electrolysis was measured by XRF, substantially 100% of the coating remained on the surface that had been roughened, and the coating on the surface that had not been roughened was reduced. This shows that the surface opposite to the membrane (roughened surface) is involved in electrolysis, and other surfaces not opposite the membrane can achieve satisfactory electrolysis performance when the amount of coverage is small or no coating.

[1381] [Example 2-4]

In Example 2-4, an electrolytic nickel foil having a measured thickness of 16 μm was used as an electrode substrate for electrolysis at the cathode. One surface of this nickel foil was roughened by an electrolytic nickel plating process. The arithmetic mean Ra of the roughness of the rough surface was 0.71 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. The open porosity ratio was 75%. Except as described above, the evaluation was performed in the same manner as in Example 2-1, and the results are shown in Table 4.

The electrode thickness was 24 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 8 µm.

Sufficient traction was observed.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 0 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0023 (kPa · s / m) at measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0".

When the amount of coating after electrolysis was measured by XRF, substantially 100% of the coating remained on the surface that had been roughened, and the coating on the surface that had not been roughened was reduced. This shows that the surface opposite to the membrane (roughened surface) is involved in electrolysis, and other surfaces not opposite the membrane can achieve satisfactory electrolysis performance when the amount of coverage is small or no coating.

[1382] [Example 2-5]

In Example 2-5, an electrolytic nickel foil having a measured thickness of 20 μm was used as an electrode substrate for electrolysis at the cathode. Both surfaces of this nickel foil were roughened by an electrolytic nickel plating process. The arithmetic average Ra of the roughness of the rough surface was 0.96 μm. Both surfaces had the same roughness. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. The open porosity ratio was 49%. Except as described above, the evaluation was performed in the same manner as in Example 2-1, and the results are shown in Table 4.

The electrode thickness was 30 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 10 µm. The coating was also formed on a surface that was not roughened.

Sufficient traction was observed.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 0 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0023 (kPa · s / m) at measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0".

In addition, when the amount of coating after electrolysis was measured by XRF, substantially 100% of the coating remained on both surfaces. By comparison with Examples 2-1 to 2-4, this shows that other surfaces not opposed to the membrane can achieve satisfactory electrolysis performance when the amount of coverage is small or no coating.

[1383] [Example 2-6]

In Example 2-6, evaluation was performed in the same manner as in Example 2-1, except that the coating of the electrode substrate for electrolysis on the cathode was deposited by ion deposition, and the results are shown in Table 4. In ion deposition, film formation was performed using a target from metallic Ru at a heating temperature of 200 ° C and in an argon / oxygen atmosphere, at a pressure for film formation of 7 × 10 ^–2 Pa. The formed coating was ruthenium oxide.

The electrode thickness was 26 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 10 µm.

Sufficient traction was observed.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 0 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less under measurement condition 1 and 0.0028 (kPa · s / m) under measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0".

[1384] [Example 2-7]

In Example 2-7, an electrode substrate for electrolysis at the cathode was prepared by an electrospinning method. The photomask had a shape formed by placing vertically and horizontally squares measuring 0.485 mm × 0.485 mm with an interval of 0.15 mm. Exposure, development, and electrodeposition were sequentially carried out to obtain a porous nickel foil having a measured thickness of 20 μm and an open porosity ratio of 56%. The arithmetic average Ra of the surface roughness was 0.71 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except as described above, the evaluation was performed in the same manner as in Example 2-1, and the results are shown in Table 4.

The electrode thickness was 37 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 17 µm.

Sufficient traction was observed.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 0 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less under measurement condition 1 and 0.0032 (kPa · s / m) under measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0".

[1385] [Example 2-8]

In Example 2-8, an electrode substrate for electrolysis at the cathode was obtained by an electrospinning method. The substrate had a measured thickness of 50 μm and an open porosity ratio of 56%. The arithmetic average Ra of the surface roughness was 0.73 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except as described above, the evaluation was performed in the same manner as in Example 2-1, and the results are shown in Table 4.

The electrode thickness was 60 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 10 µm.

Sufficient traction was observed.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 0 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less under measurement condition 1 and 0.0032 (kPa · s / m) under measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0".

[1386] [Example 2-9]

In Example 2-9, a nickel nonwoven fabric having a measured thickness of 150 µm and a void ratio of 76% (manufactured by NIKKO TECHNO, Ltd.) was used as an electrode substrate for cathode electrolysis. The nonwoven fabric had a nickel fiber diameter of 40 μm and a basis weight of 300 g / m ² . Except as described above, the evaluation was performed in the same manner as in Example 2-1, and the results are shown in Table 4.

The electrode thickness was 165 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 15 µm.

Sufficient traction was observed.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 29 mm and the electrode did not return to its original flat state. Then, when evaluating the softness after plastic deformation, the electrode was adhered to the membrane under surface tension. Thus, it was found that the electrode was able to come into contact with the membrane with little force, even if the electrode had plastic deformation, and the electrode had satisfactory workability.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0612 (kPa · s / m) at measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. The electrode had a workability of "2" and was determined to be suitable for use as a large laminated article. Membrane damage was rated as good: "0".

[1387] [Example 2-10]

In Example 2-10, a nickel nonwoven fabric having a measured thickness of 200 µm and a void ratio of 72% (manufactured by NIKKO TECHNO, Ltd.) was used as an electrode substrate for cathode electrolysis. The nonwoven fabric had a nickel fiber diameter of 40 µm and a basis weight of 500 g / m ² . Except as described above, the evaluation was performed in the same manner as in Example 2-1, and the results are shown in Table 4.

The electrode thickness was 215 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 15 µm.

Sufficient traction was observed.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 40 mm and the electrode did not return to its original flat state. Then, when evaluating the softness after plastic deformation, the electrode was adhered to the membrane under surface tension. Thus, it was found that the electrode was able to come into contact with the membrane with little force, even if the electrode had plastic deformation, and the electrode had satisfactory workability.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0164 (kPa · s / m) at measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. The electrode had a workability of "2" and was determined to be suitable for use as a large laminated article. Membrane damage was rated as good: "0".

[1388] [Example 2-11]

In Example 2-11, a porous nickel having a measured thickness of 200 µm and a void ratio of 72% (manufactured by Mitsubishi Materials Corporation) was used as an electrode substrate for cathode electrolysis. Except as described above, the evaluation was performed in the same manner as in Example 2-1, and the results are shown in Table 4.

The electrode thickness was 210 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 10 µm.

Sufficient traction was observed.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 17 mm and the electrode did not return to its original flat state. Then, when evaluating the softness after plastic deformation, the electrode was adhered to the membrane under surface tension. Thus, it was found that the electrode was able to come into contact with the membrane with little force, even if the electrode had plastic deformation, and the electrode had satisfactory workability.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0402 (kPa · s / m) at measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. The electrode had a workability of "2" and was determined to be suitable for use as a large laminated article. Membrane damage was rated as good: "0".

[1389] [Example 2-12]

In Example 2-12, a 200 mesh nickel grid having a wire diameter of 50 µm, a measured thickness of 100 µm and an open porosity ratio of 37% was used as an electrode substrate for cathode electrolysis. Blasting was performed using 320 grit alumina. Blasting did not change the open porosity ratio. It was difficult to measure the surface roughness of the wire mesh. Then, in Example 2-12, a nickel plate having a thickness of 1 mm was simultaneously blasted during blasting, and the surface roughness of the nickel plate was taken as the surface roughness of the wire mesh. The arithmetic average Ra of the surface roughness was 0.64 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except as described above, the evaluation was performed in the same manner as in Example 2-1, and the results are shown in Table 4.

The electrode thickness was 110 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 10 µm.

Sufficient traction was observed.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 0.5 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0154 (kPa · s / m) at measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good, like "1". Membrane damage was rated as good: "0".

[1390] [Example 2-13]

In Example 2-13, a 150 mesh nickel grid with a wire diameter of 65 µm, a measured thickness of 130 µm and an open porosity ratio of 38% was used as an electrode substrate for cathode electrolysis. Blasting was performed using 320 grit alumina. Blasting did not change the open porosity ratio. It was difficult to measure the surface roughness of the wire mesh. Then, in Example 2-13, a nickel plate having a thickness of 1 mm was simultaneously blasted during blasting, and the surface roughness of the nickel plate was taken as the surface roughness of the wire mesh. The arithmetic average Ra of the surface roughness was 0.66 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except as described above, the evaluation was performed in the same manner as in Example 2-1, and the results are shown in Table 4.

The electrode thickness was 133 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 3 µm.

Sufficient traction was observed.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 6.5 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0124 (kPa · s / m) at measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. The electrode had a workability of "2" and was determined to be useful as a large laminated article. Membrane damage was also rated as good: "0".

[1391] [Example 2-14]

In Example 2-14, as an electrode substrate for electrolysis at the cathode, a substrate identical to that in Example 2-3 (measured thickness 30 µm and open porosity ratio 44%) was used. The electrolysis performance was evaluated on a structure identical to that in Example 2-1, except that a nickel mesh was not used as the supply conductor. That is, in the sectional structure, the cell, the current collector, the mat, the electrode combined with the membrane, and the anode were placed in this order from the side of the cathode chamber to form a structure with a zero gap, and the mat served as a supply conductor. Except as described above, the evaluation was performed in the same manner as in Example 2-1, and the results are shown in Table 4.

Sufficient traction was observed.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 0 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less under measurement condition 1 and 0.0027 (kPa · s / m) under measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0".

[1392] [Example 2-15]

In Example 2-15, as the electrode substrate for electrolysis at the cathode, a substrate identical to that in Example 2-3 (measured thickness 30 µm and open porosity ratio 44%) was used. The cathode used in Test Example 1, which was worn out and had an increased electrolysis voltage, was placed in place of the nickel grid as a supply conductor. Except as described above, the electrolysis performance was evaluated on a structure identical to that in Example 2-1. That is, in a sectional structure, a cell, a down conductor, a mat, a cathode that was worn out and had an increased electrolysis voltage (serving as a supply conductor), an electrolysis electrode (cathode), a membrane and an anode, were placed in this order from the side of the cathode chamber to form zero-gap designs, and the cathode, which is worn out and has an increased electrolysis voltage, served as the supply conductor. Except as described above, the evaluation was performed in the same manner as in Example 2-1, and the results are shown in Table 4.

Sufficient traction was observed.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 0 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less under measurement condition 1 and 0.0027 (kPa · s / m) under measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0".

[1393] [Example 2-16]

As an electrode substrate for electrolysis at the anode, a titanium foil having a measured thickness of 20 µm was used. Both surfaces of the titanium foil were roughened. A porous foil was formed by punching this titanium foil to form circular holes by punching. The hole diameter was 1 mm and the open porosity ratio was 14%. The arithmetic average Ra of the surface roughness was 0.37 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate.

A cover fluid for use in forming an electrode catalyst was prepared according to the following procedure. Solutions of ruthenium chloride having a ruthenium concentration of 100 g / L (Tanaka Kikinzoku Kogyo KK), iridium chloride having an iridium concentration of 100 g / L (Tanaka Kikinzoku Kogyo KK), and titanium tetrachloride (Wako Pure Chemical Industries, Ltd.) mixed so that the molar ratio of ruthenium element, iridium element and titanium element was 0.25: 0.25: 0.5. This mixed solution was thoroughly mixed and used as an anode coating liquid.

[1394] A bath containing the above coating liquid was placed in the lowest position of the roller coater. The vat was positioned such that a coating roll obtained by winding a closed cell type EPDM sponge rubber (INOAC CORPORATION, E-4088, 10 mm thick) around a polyvinyl chloride (PVC) cylinder was always in contact with the casing fluid. A roller for coating, around which the same EPDM was wound, was placed on its upper part, and a PVC roller was additionally placed above it. The coating liquid was applied in such a way that the electrode substrate was passed between the second coating roller and the PVC roller in the uppermost position (roller coating method). After the above coating liquid was applied to the titanium porous foil, drying was carried out at 60 ° C for 10 minutes and firing at 475 ° C for 10 minutes. A series of these operations of coating, drying, pre-calcining, and calcining were performed several times, and then calcination was carried out at 520 ° C. for one hour.

The electrode obtained by the above method was cut into pieces measuring 95 mm in length and 110 mm in width to evaluate the performance of electrolysis. The cut electrode sample was adhered using the surface tension of an aqueous solution at substantially the central position of the sulfonic acid layer side of the ion exchange membrane A (size: 160 mm × 160 mm) obtained in [Method (i)] and equilibrated with aqueous 0, 1 n. NaOH solution.

[1395] The cathode was obtained according to the following procedure. First, a 40 mesh nickel wire mesh having a wire diameter of 150 µm was prepared as a substrate. After blasting with aluminum oxide as a pretreatment, the wire mesh was immersed in 6-normal hydrochloric acid for 5 minutes, thoroughly washed with clean water and dried.

Then, a ruthenium chloride solution having a ruthenium concentration of 100 g / L (from Tanaka Kikinzoku Kogyo KK) and a cerium chloride solution (from KISHIDA CHEMICAL Co., Ltd.) were mixed so that the molar ratio between ruthenium element and cerium element was 1: 0 , 25. This mixed solution was thoroughly mixed and used as a covering liquid for the cathode.

The bath containing the above coating liquid was placed in the lowest position of the roller coater. The vat was positioned such that a coating roll obtained by winding a closed cell type EPDM sponge rubber (INOAC CORPORATION, E-4088, 10 mm thick) around a polyvinyl chloride (PVC) cylinder was always in contact with the casing fluid. A roller for coating, around which the same EPDM was wound, was placed on its upper part, and a PVC roller was additionally placed above it. The coating liquid was applied in such a way that the electrode substrate was passed between the second coating roller and the PVC roller in the uppermost position (roller coating method). Then thereafter, drying was carried out at 50 ° C for 10 minutes, pre-firing at 300 ° C for 3 minutes, and firing at 550 ° C for 10 minutes. Thereafter, firing was carried out at 550 ° C. for an hour. A series of these operations of coating, drying, pre-firing and firing was repeated.

[1396] A nickel expanded metal sheet was used as a current collector of the cathode chamber. The down conductor was 95 mm long × 110 mm wide. As the metal elastic body, a mat formed by knitting a thin nickel wire was used. The mat as a metal elastic body was placed on the down conductor. A cathode obtained by the above method was placed on top of it, and a cord made of Teflon (R) was used to fix the four corners of the grid to the down conductor.

Even when the four corners of the membrane portion of the membrane-combined electrode, which was obtained by combining the membrane with the electrode, were clamped and suspended so that the membrane-integrated electrode was parallel to the base so that the electrode was facing toward the base, the electrode did not detach or move. In addition, when both ends of one side were clamped and suspended so that the membrane-integrated electrode was perpendicular to the base, the electrode did not detach or move.

[1397] The anode used in Test Example 3, which was worn out and had an increased electrolysis voltage, was fixed in the anode cell by welding, and the above membrane-combined electrode was inserted between the anode cell and the cathode cell so that the surface to which the electrode was attached was facing the side of the anode chamber. That is, in the sectional structure, the cell, the current collector, the mat, the cathode, the membrane, the electrode for electrolysis (titanium porous foil as the anode) and the anode, which was worn out and had an increased electrolysis voltage, were placed in the indicated order from the side of the cathode chamber to form a structure with zero clearance. The anode, which was worn out and had an increased electrolysis voltage, served as a supply conductor. The anode made of titanium porous foil and the anode, which was worn out and had an increased electrolysis voltage, were only in physical contact with each other, and were not bonded to each other by welding.

[1398] The evaluation of this construct was carried out in the same manner as in Example 2-1, and the results are shown in Table 4.

The electrode thickness was 26 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 6 µm.

Sufficient traction was observed.

When a strain test was performed on the electrode, the average of L ₁ and L ₂ was 4 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0060 (kPa · s / m) at measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good, like "1". Membrane damage was also rated as good: "0".

[1399] [Example 2-17]

In Example 2-17, a titanium foil having a measured thickness of 20 μm and an open porosity ratio of 30% was used as an electrode substrate for electrolysis at the anode. The arithmetic average Ra of the surface roughness was 0.37 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except as described above, the assessment was performed in the same manner as in Example 2-16, and the results are shown in Table 4.

The electrode thickness was 30 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 10 µm.

Sufficient traction was observed.

When a strain test was performed on the electrode, the average of L ₁ and L ₂ was 5 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less under measurement condition 1 and 0.0030 (kPa · s / m) under measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0".

[1400] [Example 2-18]

In Example 2-18, a titanium foil having a measured thickness of 20 μm and an open porosity ratio of 42% was used as an electrode substrate for electrolysis at the anode. The arithmetic average Ra of the surface roughness was 0.38 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except as described above, the assessment was performed in the same manner as in Example 2-16, and the results are shown in Table 4.

The electrode thickness was 32 µm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 12 µm.

Sufficient traction was observed.

When a strain test was performed on the electrode, the average of L ₁ and L ₂ was 2.5 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0022 (kPa · s / m) at measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0".

[1401] [Example 2-19]

In Example 2-19, a titanium foil having a measured thickness of 50 μm and an open porosity ratio of 47% was used as an electrode substrate for electrolysis at the anode. The arithmetic average Ra of the surface roughness was 0.40 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except as described above, the assessment was performed in the same manner as in Example 2-16, and the results are shown in Table 4.

The electrode thickness was 69 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 19 µm.

Sufficient traction was observed.

When a strain test was performed on the electrode, the average of L ₁ and L ₂ was 8 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0024 (kPa · s / m) at measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0".

[1402] [Example 2-20]

In Example 2-20, a titanium nonwoven fabric having a measured thickness of 100 µm, a titanium fiber diameter of about 20 µm, a basis weight of 100 g / m ² and an open porosity ratio of 78% was used as an electrode substrate for electrolysis at the anode. Except as described above, the assessment was performed in the same manner as in Example 2-16, and the results are shown in Table 4.

The electrode thickness was 114 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 14 µm.

Sufficient traction was observed.

When a strain test was performed on the electrode, the average of L ₁ and L ₂ was 2 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0228 (kPa · s / m) at measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0".

[1403] [Example 2-21]

In Example 2-21, a 150 mesh titanium wire mesh having a measured thickness of 120 µm and a titanium fiber diameter of 60 µm was used as an electrode substrate for electrolysis at the anode. The open porosity ratio was 42%. Blasting was carried out using 320 grit alumina. It was difficult to measure the surface roughness of the wire mesh. Then, in Example 2-21, a titanium plate having a thickness of 1 mm was simultaneously blasted during blasting, and the surface roughness of the titanium plate was taken as the surface roughness of the wire mesh. The arithmetic average Ra of the surface roughness was 0.60 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except as described above, the assessment was performed in the same manner as in Example 2-16, and the results are shown in Table 4.

The electrode thickness was 140 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 20 µm.

Sufficient traction was observed.

When a strain test was performed on the electrode, the average of L ₁ and L ₂ was 10 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0132 (kPa · s / m) at measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0".

[1404] [Example 2-22]

[1405] In Example 2-22, an anode that was worn out and had an increased electrolysis voltage was used in the same way as in Example 2-16 as the anode supply conductor, and a titanium nonwoven fabric identical to the material in Example 2-20, used as an anode. A cathode that was worn out and had an increased electrolysis voltage was used in the same way as in Example 2-15 as the cathode supply conductor, and a nickel foil electrode identical to that in Example 2-3 was used as the cathode. In a sectional structure, a cell, a down conductor, a mat, a cathode that was worn out and had an increased electrolysis voltage, a nickel porous foil as a cathode, a membrane, a titanium nonwoven fabric as an anode, and an anode that was worn out and had an increased electrolysis voltage were placed in in this order from the side of the cathode chamber to form a zero-gap structure, and the cathode and anode, which were worn out and had an increased electrolysis voltage, served as a supply conductor. Except as described above, the evaluation was performed in the same way as in Example 2-1, and the results are shown in Table 4.

The thickness of the electrode (anode) was 114 µm, and the thickness of the catalytic layer, which was determined by subtracting the thickness of the electrolysis electrode substrate from the thickness of the electrode (anode), was 14 µm. The thickness of the electrode (cathode) was 38 µm, and the thickness of the catalytic layer, which was determined by subtracting the thickness of the electrolysis electrode substrate from the thickness of the electrode (cathode), was 8 µm.

Sufficient adhesion force was observed at both the anode and cathode.

When the deformation test of the electrode (anode) was carried out, the average of L ₁ and L ₂ was 2 mm. When the deformation test of the electrode (cathode) was carried out, the average of L ₁ and L ₂ was 0 mm.

When the ventilation resistance of the electrode (anode) was measured, the ventilation resistance was 0.07 (kPa s / m) or less under measurement conditions 1 and 0.0228 (kPa s / m) under measurement conditions 2. When the ventilation resistance of the electrode ( cathode), the ventilation resistance was 0.07 (kPa s / m) or less under measurement condition 1 and 0.0027 (kPa s / m) under measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0" for both the anode and cathode. In Example 2-22, the cathode and anodes were combined by attaching the cathode to one surface of the membrane and the anode to the other surface of the membrane, and evaluated for membrane damage.

[1406] [Example 2-23]

In Example 2-23, a Zirfon Perl UTP 500 microporous membrane from Agfa was used.

The Zirfon membrane was immersed in clean water for 12 hours or more and used for testing. Except for the above, the above evaluation was performed in the same way as in Example 2-3, and the results are shown in Table 4.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 0 mm. It was found that the electrode had a wide range of elastic deformation.

Similar to the situation where an ion exchange membrane was used as the membrane, sufficient adhesion force was observed. The microporous membrane was brought into tight contact with the electrode by surface tension, and the workability was good: "1".

[1407] [Example 2-24]

As an electrode substrate for electrolysis at the cathode, a carbon cloth made by weaving carbon fiber having a measured thickness of 566 µm was used. A cover fluid for use in forming an electrode catalyst on this carbon fabric was prepared according to the following procedure. A ruthenium nitrate solution having a ruthenium concentration of 100 g / L (from FURUYA METAL Co., Ltd.) and a cerium nitrate solution (from KISHIDA CHEMICAL Co., Ltd.) were mixed so that the molar ratio between ruthenium and cerium was 1 : 0.25. This mixed solution was thoroughly mixed and used as a covering liquid for the cathode.

The bath containing the above coating liquid was placed in the lowest position of the roller coater. The vat was positioned such that a coating roll obtained by winding a closed cell EPDM sponge rubber (INOAC CORPORATION, E-4088 (trade name), 10 mm thick) around a polyvinyl chloride (PVC) ) of the cylinder, was always in contact with the cover fluid. A roller for coating, around which the same EPDM was wound, was placed on its upper part, and a PVC roller was additionally placed above it. The coating liquid was applied in such a way that the electrode substrate was passed between the second coating roller and the PVC roller in the uppermost position (roller coating method). Then, after drying at 50 ° C for 10 minutes, pre-firing at 150 ° C for 3 minutes and firing at 350 ° C for 10 minutes were carried out. A series of these operations of coating, drying, pre-baking and baking were repeated until a predetermined coating value was reached. The thickness of the resulting electrode was 570 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 4 µm. The thickness of the catalytic layer was the combined thickness of ruthenium oxide and cerium oxide.

[1408] The resulting electrode was subjected to electrolysis performance evaluation. The results are shown in Table 4.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 0 mm.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.19 (kPa · s / m) or less at measurement condition 1 and 0.176 (kPa · s / m) at measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0".

The electrode had a workability of "2" and was determined to be suitable for use as a large laminated article.

The voltage was high, membrane damage was rated as "1" and membrane damage was observed. It is assumed that this is due to the action of NaOH, which was formed in the electrode, accumulating at the interface between the electrode and the membrane with an increase in its concentration, due to the high ventilation resistance of the electrode in Example 2-24.

[1409] [Test Case 1]

In Control Example 1, a cathode was used that had been used as a cathode in a large cell for eight years, which was worn out and showed an increased electrolysis voltage. The above cathode was placed instead of a nickel mesh feed conductor on the cathode chamber mat, and an ion exchange membrane A obtained in [Method (i)] was placed between them. The electrolysis performance was then evaluated. In Control Example 1, the membrane-integrated electrode was not used. In the sectional structure, the cell, the current collector, the mat, the cathode, which was worn out and showed an increased electrolysis voltage, the ion-exchange membrane A and the anodes were placed in the indicated order from the side of the cathode chamber to form a structure with a zero gap.

As a result of evaluating the characteristics of electrolysis to this structure, the voltage was 3.04 V, was 97.0% current efficiency, the total concentration of salt in caustic soda (a value converted based on 50%) was 20 million ^-1. Thus, due to electrode wear, the voltage was high.

[1410] [Test Case 2]

In Control Example 2, a nickel mesh feed conductor was used as the cathode. That is, the electrolysis was carried out on a nickel grid that does not have a catalytic coating.

A nickel mesh cathode was placed on the cathode chamber mat and an ion exchange membrane A obtained in [Method (i)] was placed between them. The electrolysis performance was then evaluated. In the sectional structure of the electrical cell of Test Example 2, a down conductor, mat, nickel mesh, ion exchange membrane A, and anodes were placed in this order from the side of the cathode chamber to form a zero-gap structure.

As a result of evaluating the characteristics of electrolysis to this structure, the voltage was 3.38 V, was 97.7% current efficiency, the total concentration of salt in caustic soda (a value converted based on 50%) was 24 million ^-1. Thus, the voltage was high due to the uncoated cathode catalyst.

[1411] [Test Case 3]

In Control Example 3, an anode was used as the anode, which had been used in a large cell for about eight years, was worn out, and showed an increased electrolysis voltage.

In the sectional design of the electrical cell of Test Example 3, a down conductor, mat, cathode, and ion exchange membrane A obtained in [Method (i)], and an anode that was worn out and showed an increased electrolysis voltage were placed in that order from the side of the cathode chamber to form zero clearance designs.

As a result of evaluating the characteristics of electrolysis to this structure, the voltage was 3.18 V, was 97.0% current efficiency, the total concentration of salt in caustic soda (a value converted based on 50%) was 22 million ^-1. Thus, the electrical voltage was high due to the wear of the anode.

[1412] [Example 2-25]

In Example 2-25, a fully rolled nickel expanded metal sheet having a measured thickness of 100 µm and an open porosity ratio of 33% was used as an electrode substrate for cathode electrolysis. Blasting was carried out using alumina with a grit number of 320. The open porosity ratio did not change after blasting. It was difficult to measure the surface roughness of expanded metal sheet. Then, in Example 2-25, a nickel plate having a thickness of 1 mm was simultaneously blasted during blasting, and the surface roughness of the nickel plate was taken as the surface roughness of the wire mesh. The arithmetic average Ra of the surface roughness was 0.68 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except as described above, the evaluation was performed in the same manner as in Example 2-1, and the results are shown in Table 4.

The electrode thickness was 114 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 14 µm.

The mass per unit area was 67.5 (mg / cm ² ). The force applied per unit mass · unit area (1) was as small as 0.05 N / (mg · cm ² ). Thus, the result of evaluating the coiling around a string with a diameter of 280 mm (2) was 64%, and the result of evaluating the coiling around a string with a diameter of 145 mm (3) was 22%. The areas where the electrode separated from the membrane were enlarged. This was caused by problems in that the electrode would most likely detach when the combined electrode was used and that the electrode would separate and fall off the diaphragm during loading and unloading. Manufacturability was "4", which was also problematic. Membrane damage was scored "0".

When a strain test was performed on the electrode, the average of L ₁ and L ₂ was 13 mm.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0168 (kPa · s / m) at measurement condition 2.

[1413] [Example 2-26]

In Example 2-26, a fully rolled nickel expanded metal sheet having a measured thickness of 100 μm and an open porosity ratio of 16% was used as an electrode substrate for cathode electrolysis. Blasting was carried out using alumina with a grit number of 320. The open porosity ratio did not change after blasting. It was difficult to measure the surface roughness of expanded metal sheet. Then, in Example 2-26, a nickel plate having a thickness of 1 mm was simultaneously blasted during blasting, and the surface roughness of the nickel plate was taken as the surface roughness of the wire mesh. The arithmetic average Ra of the surface roughness was 0.64 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except as described above, the evaluation was performed in the same manner as in Example 2-1, and the results are shown in Table 4.

The electrode thickness was 107 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 7 µm.

The mass per unit area was 78.1 (mg / cm ² ). The force applied per unit mass · unit area (1) was as small as 0.04 N / (mg · cm ² ). Thus, the result of evaluating the coiling around a string with a diameter of 280 mm (2) was 37%, and the result of evaluating the coiling around a string with a diameter of 145 mm (3) was 25%. The areas where the electrode separated from the membrane were enlarged. This was caused by problems in that the electrode would most likely detach when the combined electrode was used and that the electrode would separate and fall off the diaphragm during loading and unloading. Manufacturability was "4", which was also problematic. Membrane damage was scored "0".

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 18.5 mm.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0176 (kPa · s / m) at measurement condition 2.

[1414] [Example 2-27]

In Example 2-27, a fully rolled nickel expanded metal sheet having a measured thickness of 100 μm and an open porosity ratio of 40% was used as an electrode substrate for cathode electrolysis. Blasting was carried out using alumina with a grit number of 320. The open porosity ratio did not change after blasting. It was difficult to measure the surface roughness of expanded metal sheet. Then, in Example 2-27, a nickel plate having a thickness of 1 mm was simultaneously blasted during blasting, and the surface roughness of the nickel plate was taken as the surface roughness of the wire mesh. The arithmetic mean Ra of the surface roughness was 0.70 µm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Coating on the electrolysis electrode substrate was performed by ion deposition in the same manner as in Example 2-6. Except as described above, the evaluation was performed in the same way as in Example 2-1, and the results are shown in Table 4.

The electrode thickness was 110 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 10 µm.

The force applied per unit mass · unit area (1) was as small as 0.07 N / (mg · cm ² ). Thus, the evaluation result of the coiling around a 280 mm diameter string (2) was 80%, and the evaluation result of the coiling around a 145 mm diameter string (3) was 32%. The areas where the electrode separated from the membrane were enlarged. This was caused by problems in that the electrode would most likely detach when the combined electrode was used and that the electrode would separate and fall off the diaphragm during loading and unloading. Manufacturability was "3", which was also problematic. Membrane damage was scored "0".

When a strain test was performed on the electrode, the average of L ₁ and L ₂ was 11 mm.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less under measurement condition 1 and 0.0030 (kPa · s / m) under measurement condition 2.

[1415] [Example 2-28]

In Example 2-28, a fully rolled nickel expanded metal sheet having a measured thickness of 100 μm and an open porosity ratio of 58% was used as an electrode substrate for cathode electrolysis. Blasting was carried out using alumina with a grit number of 320. The open porosity ratio did not change after blasting. It was difficult to measure the surface roughness of expanded metal sheet. Then, in Example 2-28, a nickel plate having a thickness of 1 mm was simultaneously blasted during blasting, and the surface roughness of the nickel plate was taken as the surface roughness of the wire mesh. The arithmetic average Ra of the surface roughness was 0.64 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except as described above, the evaluation was performed in the same way as in Example 2-1, and the results are shown in Table 4.

The electrode thickness was 109 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 9 µm.

The force applied per unit mass · unit area (1) was as small as 0.06 N / (mg · cm ² ). Thus, the result of evaluating the coiling around a string with a diameter of 280 mm (2) was 69%, and the result of evaluating the coiling around a string with a diameter of 145 mm (3) was 39%. The areas where the electrode separated from the membrane were enlarged. This was caused by problems in that the electrode would most likely detach when the combined electrode was used and that the electrode would separate and fall off the diaphragm during loading and unloading. Manufacturability was "3", which was also problematic. Membrane damage was scored "0".

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 11.5 mm.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less under measurement condition 1 and 0.0028 (kPa · s / m) under measurement condition 2.

[1416] [Example 2-29]

In Example 2-29, a nickel wire mesh having a measured thickness of 300 μm and an open porosity ratio of 56% was used as an electrode substrate for cathode electrolysis. It was difficult to measure the surface roughness of the wire mesh. Then, in Example 2-29, a nickel plate having a thickness of 1 mm was simultaneously blasted during blasting, and the surface roughness of the nickel plate was taken as the surface roughness of the wire mesh. Blasting was carried out using alumina with a grit number of 320. The open porosity ratio did not change after blasting. The arithmetic average Ra of the surface roughness was 0.64 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except as described above, the evaluation was performed in the same way as in Example 2-1, and the results are shown in Table 4.

The electrode thickness was 308 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 8 µm.

The mass per unit area was 49.2 (mg / cm ² ). Thus, the evaluation result of the coiling around a 280 mm diameter string (2) was 88%, and the evaluation result of the coiling around a 145 mm diameter string (3) was 42%. The areas where the electrode separated from the membrane were enlarged. This was due to the fact that the electrode was most likely detached when an electrode combined with the membrane was used, and that the electrode separated and fell off the membrane during loading and unloading. A problem arose regarding manufacturability, which was rated as "3". When a large electrode was actually operated, the manufacturability could be rated as "3". Membrane damage was scored "0".

When a strain test was performed on the electrode, the average of L ₁ and L ₂ was 23 mm.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0034 (kPa · s / m) at measurement condition 2.

[1417] [Example 2-30]

In Example 2-30, a nickel wire mesh having a measured thickness of 200 μm and an open porosity ratio of 37% was used as an electrode substrate for cathode electrolysis. Blasting was carried out using alumina with a grit number of 320. The open porosity ratio did not change after blasting. It was difficult to measure the surface roughness of the wire mesh. Then, in Example 2-30, a nickel plate having a thickness of 1 mm was simultaneously blasted during blasting, and the surface roughness of the nickel plate was taken as the surface roughness of the wire mesh. The arithmetic average Ra of the surface roughness was 0.65 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except for the above, the evaluation of the electrolysis on the electrode, the results of the measurement of the adhesion force and adhesion were carried out in the same manner as in Example 2-1. The results are shown in Table 4.

The electrode thickness was 210 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 10 µm.

The weight per unit area was 56.4 mg / cm ² . Thus, the result of evaluating the wrap around the 145 mm diameter string (2) was 63%, and the adhesion between the electrode and the membrane was poor. This was due to the fact that the electrode was most likely detached when an electrode combined with the membrane was used, and that the electrode separated and fell off the membrane during loading and unloading. A problem arose regarding manufacturability, which was rated as "3". Membrane damage was scored "0".

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 19 mm.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less under measurement condition 1 and 0.0096 (kPa · s / m) under measurement condition 2.

[1418] [Example 2-31]

In Example 2-31, a fully rolled titanium expanded metal sheet having a measured thickness of 500 μm and an open porosity ratio of 17% was used as an electrode substrate for electrolysis at the anode. Blasting was carried out using alumina with a grit number of 320. The open porosity ratio did not change after blasting. It was difficult to measure the surface roughness of expanded metal sheet. Then, in Example 2-31, a titanium plate having a thickness of 1 mm was simultaneously blasted during blasting, and the surface roughness of the titanium plate was taken as the surface roughness of the wire mesh. The arithmetic average Ra of the surface roughness was 0.60 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except for the above, the evaluation was performed in the same way as in Example 2-16, and the results are shown in Table 4.

The electrode thickness was 508 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 8 µm.

The weight per unit area was 152.5 (mg / cm ² ). The force applied per unit mass · unit area (1) was as small as 0.01 N / (mg · cm ² ). Thus, the result of evaluating the coiling around a string with a diameter of 280 mm (2) was 5%, and the result of evaluating the coiling around a string with a diameter of 145 mm (3) was 5%. The areas where the electrode separated from the membrane were enlarged. This was due to the fact that the electrode most likely separated when an electrode combined with the membrane was used, and that the electrode separated and fell off the membrane during loading and unloading, and so on. Manufacturability was "4", which was also problematic. Membrane damage was scored "0".

When the electrode was deformed, the electrode did not recover and remained coiled in the shape of a PVC pipe. Thus, it was impossible to measure the values of L ₁ and L _2.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0072 (kPa · s / m) at measurement condition 2.

[1419] [Example 2-32]

In Example 2-32, a fully rolled titanium expanded metal sheet having a measured thickness of 800 μm and an open porosity ratio of 8% was used as an electrode substrate for electrolysis at the anode. Blasting was carried out using alumina with a grit number of 320. The open porosity ratio did not change after blasting. It was difficult to measure the surface roughness of expanded metal sheet. Then, in Example 2-32, a titanium plate having a thickness of 1 mm was simultaneously blasted during blasting, and the surface roughness of the titanium plate was taken as the surface roughness of the wire mesh. The arithmetic average Ra of the surface roughness was 0.61 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except for the above, the evaluation was performed in the same way as in Example 2-16, and the results are shown in Table 4.

The electrode thickness was 808 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 8 µm.

The mass per unit area was 251.3 (mg / cm ² ). The force applied per unit mass · unit area (1) was as small as 0.01 N / (mg · cm ² ). Thus, the result of evaluating the coiling around a string with a diameter of 280 mm (2) was 5%, and the result of evaluating the coiling around a string with a diameter of 145 mm (3) was 5%. The areas where the electrode separated from the membrane were enlarged. This was due to the fact that the electrode most likely separated when an electrode combined with the membrane was used, and that the electrode separated and fell off the membrane during loading and unloading, and so on. Manufacturability was "4", which was also problematic. Membrane damage was scored "0".

When the electrode was deformed, the electrode did not recover and remained coiled in the shape of a PVC pipe. Thus, it was impossible to measure the values of L ₁ and L _2.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0172 (kPa · s / m) at measurement condition 2.

[1420] [Example 2-33]

In Example 2-33, a fully rolled titanium expanded metal sheet having a measured thickness of 1000 μm and an open porosity ratio of 46% was used as an electrode substrate for electrolysis at the anode. Blasting was carried out using alumina with a grit number of 320. The open porosity ratio did not change after blasting. It was difficult to measure the surface roughness of expanded metal sheet. Then, in Example 2-33, a titanium plate having a thickness of 1 mm was simultaneously blasted during blasting, and the surface roughness of the titanium plate was taken as the surface roughness of the wire mesh. The arithmetic average Ra of the surface roughness was 0.59 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except for the above, the evaluation was performed in the same way as in Example 2-16, and the results are shown in Table 4.

The electrode thickness was 1011 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 11 µm.

The mass per unit area was 245.5 (mg / cm ² ). The force applied per unit mass · unit area (1) was as small as 0.01 N / (mg · cm ² ). Thus, the result of evaluating the coiling around a string with a diameter of 280 mm (2) was 5%, and the result of evaluating the coiling around a string with a diameter of 145 mm (3) was 5%. The areas where the electrode separated from the membrane were enlarged. This was due to the fact that the electrode most likely separated when an electrode combined with the membrane was used, and that the electrode separated and fell off the membrane during loading and unloading, and so on. Manufacturability was "4", which was also problematic. Membrane damage was scored "0".

When the electrode was deformed, the electrode did not recover and remained coiled in the shape of a PVC pipe. Thus, it was impossible to measure the values of L ₁ and L _2.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less under measurement condition 1 and 0.0027 (kPa · s / m) under measurement condition 2.

[1421] [Example 2-34]

Nickel wire having a measured thickness of 150 µm was used as an electrode substrate for electrolysis at the cathode. A roughening treatment was carried out on this nickel wire. It was difficult to measure the surface roughness of the nickel wire. Then, in Example 2-34, a nickel plate having a thickness of 1 mm was simultaneously blasted during blasting, and the surface roughness of the nickel plate was taken as the surface roughness of the nickel wire. Blasting was carried out using alumina with a grain number of 320. The arithmetic average Ra of the surface roughness was 0.64 μm.

A cover fluid for use in forming an electrode catalyst was prepared according to the following procedure. A ruthenium nitrate solution having a ruthenium concentration of 100 g / L (from FURUYA METAL Co., Ltd.) and a cerium nitrate solution (from KISHIDA CHEMICAL Co., Ltd.) were mixed so that the molar ratio between ruthenium and cerium was 1 : 0.25. This mixed solution was thoroughly mixed and used as a covering liquid for the cathode.

The bath containing the above coating liquid was placed in the lowest position of the roller coater. The vat was positioned such that a coating roll obtained by winding a closed cell EPDM sponge rubber (INOAC CORPORATION, E-4088 (trade name), 10 mm thick) around a polyvinyl chloride (PVC) ) of the cylinder, was always in contact with the cover fluid. A roller for coating, around which the same EPDM was wound, was placed on its upper part, and a PVC roller was additionally placed above it. The coating liquid was applied in such a way that the electrode substrate was passed between the second coating roller and the PVC roller in the uppermost position (roller coating method). Then, after drying at 50 ° C for 10 minutes, pre-firing at 150 ° C for 3 minutes and firing at 350 ° C for 10 minutes were carried out. A series of these operations of coating, drying, pre-baking and baking were repeated until a predetermined coating value was reached. The thickness of the resulting electrode was 570 μm. The thickness of the nickel wire obtained in Example 2-34 was 158 µm.

[1422] The nickel wire obtained by the above method was cut into pieces of 110 mm in length and 95 mm in length. As shown in Figure 37, a 110 mm nickel wire and a 95 mm nickel wire were placed so that the nickel wires were vertically overlapped at the center of each of the nickel wires and connected to each other at the intersection with a cyanoacrylate superadhesive (Aron Alpha (R), from TOAGOSEI CO., LTD.) To form an electrode. The electrode was evaluated and the results are shown in Table 4.

The portion of the electrode in which the nickel wires were overlapped had the largest thickness, and the thickness of the electrode was 306 µm. The thickness of the catalytic layer was 6 μm. The open porosity ratio was 99.7%.

[1423] The mass per unit area of the electrode was 0.5 (mg / cm ² ). The forces applied per unit mass · unit area (1) and (2) were in both cases equal to or less than the lower limit of the tensile test machine. Thus, the result of evaluating the winding around a 280 mm diameter column (2) was less than 5%, and the areas where the electrode separated from the membrane were enlarged. Manufacturability was "4", which was also problematic. Membrane damage was scored "0".

When a strain test was performed on the electrode, the average of L ₁ and L ₂ was 15 mm.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.001 (kPa s / m) or less under the measurement condition 2. When the measurement was carried out under the measurement condition 2 in the SENSE mode (measuring range) of the ventilation resistance measuring device set to H (high) , the ventilation resistance was 0.0002 (kPa · s / m).

In addition, the structure shown in FIG. 38 was used to position the electrode (cathode) on the Ni-grid supply conductor, and the electrolysis performance of the electrode was evaluated by the method described in Evaluation of Electrolysis Performance (9). As a result, the voltage was high at 3.16 V.

[1424] [Example 2-35]

In Example 2-35, the electrode obtained in Comparative Example 2-34 was used. As shown in Figure 39, a 110 mm nickel wire and a 95 mm nickel wire were placed so that the nickel wires were vertically overlapped at the center of each of the nickel wires and connected to each other at the intersection with a cyanoacrylate superadhesive (Aron Alpha (R), from TOAGOSEI CO., LTD.) To form an electrode. The electrode was evaluated and the results are shown in Table 4.

The portion of the electrode in which the nickel wires were overlapped had the largest thickness, and the thickness of the electrode was 306 µm. The thickness of the catalytic layer was 6 μm. The open porosity ratio was 99.4%.

The mass per unit area of the electrode was 0.9 (mg / cm ² ). The forces applied per unit mass · unit area (1) and (2) were in both cases equal to or less than the lower limit of the tensile test machine. Thus, the result of evaluating the winding around a 280 mm diameter column (2) was less than 5%, and the areas where the electrode separated from the membrane were enlarged. Manufacturability was "4", which was also problematic. Membrane damage was scored "0".

When a strain test was performed on the electrode, the average of L ₁ and L ₂ was 16 mm.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.001 (kPa s / m) or less under the measurement condition 2. When the measurement was carried out under the measurement condition 2 in the SENSE mode (measuring range) of the ventilation resistance measuring device set to H (high) , the ventilation resistance was 0.0004 (kPa · s / m).

In addition, the structure shown in FIG. 40 was used to position an electrode (cathode) on a Ni-grid supply conductor, and the electrolysis performance of the electrode was evaluated by the method described in Evaluation of Electrolysis Performance (9). As a result, the voltage was high at 3.18 V.

[1425] [Example 2-36]

In Example 2-36, the electrode obtained in Comparative Example 2-34 was used. As shown in Figure 41, a 110 mm nickel wire and a 95 mm nickel wire were positioned so that the nickel wires were vertically overlapped at the center of each of the nickel wires and connected to each other at the intersection with cyanoacrylate superadhesive (Aron Alpha (R), from TOAGOSEI CO., LTD.) To form an electrode. The electrode was evaluated and the results are shown in Table 4.

The portion of the electrode in which the nickel wires were overlapped had the largest thickness, and the thickness of the electrode was 306 µm. The thickness of the catalytic layer was 6 μm. The open porosity ratio was 98.8%.

The mass per unit area of the electrode was 1.9 (mg / cm ² ). The forces applied per unit mass · unit area (1) and (2) were in both cases equal to or less than the lower limit of the tensile test machine. Thus, the result of evaluating the winding around a 280 mm diameter column (2) was less than 5%, and the areas where the electrode separated from the membrane were enlarged. Manufacturability was "4", which was also problematic. Membrane damage was scored "0".

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 14 mm.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.001 (kPa s / m) or less under the measurement condition 2. When the measurement was carried out under the measurement condition 2 in the SENSE mode (measuring range) of the ventilation resistance measuring device set to H (high) , the ventilation resistance was 0.0005 (kPa · s / m).

In addition, the structure shown in FIG. 42 was used to position an electrode (cathode) on the Ni-grid supply conductor, and the electrolysis performance of the electrode was evaluated by the method described in Evaluation of Electrolysis Performance (9). As a result, the voltage was high at 3.18 V.

[1426] [Comparative Example 2-1]

In Comparative Example 2-1, a heat-pressing assembly was obtained by thermocompressing a membrane electrode with reference to a prior art document (Examples in Japanese Patent Laid-Open No. 58-48686).

A nickel expanded metal sheet having a measured thickness of 100 µm and an open porosity ratio of 33% was used as an electrode substrate for cathode electrolysis to perform electrode plating in the same manner as in Example 2-1. Thereafter, one surface of the electrode was subjected to inactivation treatment according to the following procedure. A polyimide adhesive tape (from Chukoh Chemical Industries, Ltd.) was attached to one surface of the electrode. The other surface was coated with a PTFE dispersion (Dupont-Mitsui Fluorochemicals Co., Ltd., 31-JR (trade name)) and dried in a muffle oven at 120 ° C for 10 minutes. The polyimide tape was separated and fired in a muffle furnace adjusted to a temperature of 380 ° C for 10 minutes. This operation was repeated twice to inactivate one surface of the electrode.

[1427] Received a membrane formed of two layers of perfluorocarbon polymer, the end group of which is "-COOCH ₃ " (C-polymer), and a perfluorocarbon polymer, the end group of which is "-SO ₂ F" (S-polymer). The C-resin layer was 3 mils (0.003 in., 0.0762 mm) thick and the S-resin layer was 4 mils (0.004 in., 0.01 mm) thick. This bilayer membrane was subjected to a saponification treatment, thereby introducing ion exchange groups at the ends of the polymer by hydrolysis. The end groups of the C – polymer were hydrolyzed to form carboxyl groups, and the end groups of the S – polymer were hydrolyzed to form sulfo groups. The ion-exchange capacity with sulfonic acid groups was 1.0 mg-eq / g, and the ion-exchange capacity with carboxylic acid groups was 0.9 mg-eq / g.

The electrode with its inactivated surface was placed opposite the surface having carboxyl groups as ion-exchange groups, and thermocompression was performed with it, combining the ion-exchange membrane and the electrode. One surface of the electrode was open even after thermocompression, and the electrode did not spread over part of the membrane.

After that, in order to prevent the bubbles formed during electrolysis from sticking to the membrane, a mixture of zirconium oxide and a perfluorocarbon polymer into which sulfo groups were introduced was applied to both surfaces. Thereby, a membrane and electrode assembly of Comparative Example 2-1 was obtained.

[1428] When the force applied per unit mass · unit area (1) was measured using this thermocompression assembly, the electrode did not move upward because the electrode and the membrane were tightly connected by thermocompression. Then, the ion exchange membrane and the nickel plate were fixed so that they were stationary and the electrode was pulled upward with a higher force. When a force of 1.50 N / (mg · cm ² ) was reached, part of the membrane ruptured. The thermocompression knot of Comparative Example 2-1 had a force applied per unit mass · unit area (1) of at least 1.50 N / (mg · cm ² ), and they were firmly connected.

[1429] When the evaluation of the winding around the string with a diameter of 280 mm (1), the contact area with the plastic pipe was less than 5%. Meanwhile, when the evaluation of the wrapping around the 280 mm diameter column (2) was carried out, the electrode and the membrane were 100% connected to each other, but the membrane was not wrapped around the column at all. The result of evaluating the coiling around a 145 mm diameter string (3) was the same. The result showed that the integrated electrode impaired the processability of the membrane, making it difficult to wind the membrane into a roll and create folds of the membrane. Manufacturability was "3", which was problematic. Membrane damage was scored "0". In addition, when the electrolysis performance was evaluated, the electric voltage was high, the current efficiency was low, and the total concentration of salt in the caustic soda (the value converted to 50%) was increased and the electrolysis performance was deteriorated.

The electrode thickness was 114 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 14 µm.

When a strain test was performed on the electrode, the average of L ₁ and L ₂ was 13 mm.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0168 (kPa · s / m) at measurement condition 2.

[1430] [Comparative Example 2-2]

In Comparative Example 2-2, a 40 mesh nickel grid having a wire diameter of 150 µm, a measured thickness of 300 µm and an open porosity ratio of 58% was used as an electrode substrate for cathode electrolysis. Except as described above, a membrane and electrode assembly was prepared in the same manner as in Comparative Example 2-1.

When the force applied per unit mass · unit area (1) was measured using this thermocompression assembly, the electrode did not move upward because the electrode and the membrane were tightly connected by thermocompression. Then, the ion exchange membrane and the nickel plate were fixed so that they were stationary and the electrode was pulled upward with a higher force. When a force of 1.60 N / (mg · cm ² ) was reached, part of the membrane ruptured. The membrane and electrode assembly of Comparative Example 2-2 had a force applied per unit mass · unit area (1) of at least 1.60 N / (mg · cm ² ), and they were firmly connected.

[1431] When evaluating the wrapping around a 280 mm diameter column (1) using this membrane and electrode assembly, the contact area with the plastic pipe was less than 5%. Meanwhile, when the evaluation of the wrapping around the 280 mm diameter column (2) was carried out, the electrode and the membrane were 100% connected to each other, but the membrane was not wrapped around the column at all. The result of evaluating the coiling around a 145 mm diameter string (3) was the same. The result showed that the integrated electrode impaired the processability of the membrane, making it difficult to wind the membrane into a roll and create folds of the membrane. Manufacturability was "3", which was problematic. In addition, when the electrolysis performance was evaluated, the electric voltage was high, the current efficiency was low, and the total concentration of salt in the caustic soda (the value converted to 50%) was increased and the electrolysis performance was deteriorated.

The electrode thickness was 308 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 8 µm.

When a strain test was performed on the electrode, the average of L ₁ and L ₂ was 23 mm.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0034 (kPa · s / m) at measurement condition 2.

[1432]

[Table 3]

Electrode support Electrode support shape Coating method Supply conductor Example 2-1 Ni Perforation Pyrolysis Ni-mesh Example 2-2 Ni Perforation Pyrolysis Ni-mesh Example 2-3 Ni Perforation Pyrolysis Ni-mesh Example 2-4 Ni Perforation Pyrolysis Ni-mesh Example 2-5 Ni Perforation Pyrolysis Ni-mesh Example 2-6 Ni Perforation Ionic deposition Ni-mesh Example 2-7 Ni Electroforming Pyrolysis Ni-mesh Example 2-8 Ni Electroforming Pyrolysis Ni-mesh Example 2-9 Ni Non-woven fabric Pyrolysis Ni-mesh Example 2-10 Ni Non-woven fabric Pyrolysis Ni-mesh Example 2-11 Ni Porous Ni Pyrolysis Ni-mesh Example 2-12 Ni Grid Pyrolysis Ni-mesh Example 2-13 Ni Grid Pyrolysis Ni-mesh Example 2-14 Ni Perforation (same as Example 2-3) Pyrolysis Mat Example 2-15 Ni Perforation (same as Example 2-3) Pyrolysis Overvoltage cathode Example 2-16 Ti Perforation Pyrolysis Overvoltage anode Example 2-17 Ti Perforation Pyrolysis Overvoltage anode Example 2-18 Ti Perforation Pyrolysis Overvoltage anode Example 2-19 Ti Perforation Pyrolysis Overvoltage anode Example 2-20 Ti Non-woven fabric Pyrolysis Overvoltage anode Example 2-21 Ti Grid Pyrolysis Overvoltage anode Example 2-22 Ni / Ti Combination of Example 2-3 and Example 2-20 Pyrolysis Overvoltage cathode and anode Example 2-23 Ni Perforation Pyrolysis - Example 2-24 Carbon Woven fabric Pyrolysis Ni-mesh Example 2-25 Ni Expanded metal Pyrolysis Ni-mesh Example 2-26 Ni Expanded metal Pyrolysis Ni-mesh Example 2-27 Ni Expanded metal Ionic deposition Ni-mesh Example 2-28 Ni Expanded metal Pyrolysis Ni-mesh Example 2-29 Ni Grid Pyrolysis Ni-mesh Example 2-30 Ni Grid Pyrolysis Ni-mesh Example 2-31 Ti Expanded metal Pyrolysis Overvoltage anode Example 2-32 Ti Expanded metal Pyrolysis Overvoltage anode Example 2-33 Ti Expanded metal Pyrolysis Overvoltage anode Example 2-34 Ni Grid Pyrolysis Ni-mesh Example 2-35 Ni Grid Pyrolysis Ni-mesh Example 2-36 Ni Grid Pyrolysis Ni-mesh Comparative Example 2-1 Ni Expanded metal Pyrolysis Ni-mesh Comparative Example 2-2 Ni Grid Pyrolysis Ni-mesh

[1433]

[1434] In Table 4, all specimens were able to hold on their own due to surface tension before measuring "force applied per unit mass · unit area (1)" and "force applied per unit mass · unit area (2)" (that is, not slide down).

[1435] <Checking the third embodiment>

As will be described below, Experimental Examples according to the third embodiment are presented (in the <Verification of the third embodiment> section below, simply referred to as “Examples”) and Experimental Examples not corresponding to the third embodiment (in the <Verification of the third embodiment> section, hereinafter simply referred to as "Comparative Examples"), and evaluated by the following method. Details will be described with reference to Figures 57-62 as appropriate.

[1436] (1) Evaluation of electrolysis characteristics (voltage (V), current efficiency (%))

The electrolysis performance was evaluated in the following electrolysis experiment.

A titanium anode cell was placed opposite each other, having an anode chamber in which the anode (anode outlet cell) was formed, and a cathode cell having a nickel cathode chamber, in which a cathode (cathode outlet cell) was formed. A pair of seals was placed between the cells, and an ion exchange membrane was inserted between the seal and. Then, the anode cell, seal, ion exchange membrane, seal and cathode were brought into intimate contact with each other to form an electrolytic cell.

The anode was obtained by applying a mixed solution of ruthenium chloride, iridium chloride and titanium tetrachloride on a titanium substrate, subjected to blasting and acid etching as a pretreatment, followed by drying and firing. The anode was fixed in the anode chamber by welding. As the cathode, the cathode described in each of Examples and Comparative Examples was used. A nickel expanded metal sheet was used as a current collector of the cathode chamber. The down conductor was 95 mm long × 110 mm wide. As the metal elastic body, a mat formed by knitting a thin nickel wire was used. The mat as a metal elastic body was placed on the down conductor. A nickel mesh was placed on top of it, formed by a plain weave of nickel wire having a diameter of 150 μm and a mesh size of 40 mesh, and a Teflon (R) cord made of Teflon (R) was used to fix the four corners of the Ni – mesh to the down conductor. This Ni-grid was used as a supply conductor. In this electrolytic cell, the repulsive force generated by the mat as a metal resilient body was used to create a zero-gap structure. Seals made of ethylene-propylene-diene rubber (EPDM) were used as seals. As the membrane, the ion exchange membrane described below was used.

Monofilaments made of polytetrafluoroethylene (PTFE) with a size of 90 denier (hereinafter referred to as PTFE yarns) were used as reinforcing materials of the core. The warp yarns used were yarns obtained by twisting 200 times / meter of six 35 denier polyethylene terephthalate (PET) filaments. First, a plain weaving of PTFE yarns and consumable yarns was performed with 24 PTFE yarns / inch so that two consumable yarns were placed between adjacent PTFE yarns to form a woven fabric. The resulting woven fabric was compressed under pressure to obtain a woven fabric having a thickness of 70 µm.

[1437] Then there was obtained polymer A in the form of a dry resin, which was a copolymer of CF ₂ = CF ₂ and CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ COOCH ₃ and had an ion exchange capacity of 0.85 mg гeq / g and polymer B as a dry resin, which was a copolymer of CF ₂ = CF ₂ and CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₂ F and had an ion exchange capacity of 1.03 mg 1,0eq / g.

[1438] Using these polymers A and B, a two-layer film X in which the thickness of the polymer A layer was 15 µm and the thickness of the polymer B layer was 104 µm was obtained by a flat die coextrusion method.

[1439] Then release paper (having embossing with a tapered shape of 50 μm height), reinforcing material and film X were laminated in this order on a hot plate having a heat source and a vacuum source inside and having micropores on its surface, heated and depressurized under conditions of a hot plate surface temperature of 223 ° C. and a reduced pressure value of 0.067 MPa for 2 minutes, and then removing the release paper to obtain a composite membrane.

[1440] The resulting composite membrane was immersed in an aqueous solution heated to 80 ° C. containing 30% by weight of dimethyl sulfoxide (DMSO) and 15% by weight of potassium hydroxide (KOH) for 20 minutes for saponification. Then the composite membrane was immersed in an aqueous 0.5N hydrochloric acid heated to 50 ° C. sodium hydroxide solution (NaOH) for one hour to replace the counterion of the ion exchange group with Na, and then washed with water. Then the membrane was dried at 60 ° C.

[1441] In addition, 20% by mass of zirconium oxide having an average particle size (primary particle size) of 1 μm was added to an ethanol solution with a concentration of 5% by mass of resin B as an acid-type resin and dispersed to obtain a slurry, and the slurry was applied by spraying to both surfaces of the above composite membrane by a slurry spraying method to form zirconium oxide coatings on the surfaces of the composite membrane to obtain an ion exchange membrane. The density of the zirconium oxide coating, measured by X-ray fluorescence analysis, was 0.5 mg / cm ² . The average particle size was measured with a particle size analyzer (manufactured by SHIMADZU CORPORATION, "SALD (R) 2200").

[1442] The above electrolytic cell was used to perform ordinary salt electrolysis. The brine concentration (sodium chloride concentration) in the anode chamber was adjusted to 205 g / L. The concentration of sodium hydroxide in the cathode compartment was adjusted to 32% by weight. The temperature of each of the anode chamber and the cathode chamber was adjusted so that the temperature in each chamber could reach 90 ° C. Conventional salt electrolysis was carried out at a current density of 6 kA / m ² by measuring the voltage and current density. The current efficiency here is the ratio of the amount of caustic soda formed to the passed current, and when impurity ions and hydroxide ions, rather than sodium ions, pass through the ion exchange membrane under the influence of the passed current, the current efficiency decreases. The current efficiency was obtained by dividing the number of moles of caustic soda formed during a given time by the number of moles of electrons of current passed during that time. The number of moles of caustic soda was obtained by separating the caustic soda formed during electrolysis into a plastic container and measuring its weight.

[1443] (2) Manufacturability (reaction evaluation)

(A) The above ion exchange membrane A (membrane) was cut to form a 170 mm square piece, and the electrode obtained in each of the following Examples and Comparative Examples was cut into pieces of 95 × 110 mm. The ion exchange membrane and electrode were layered and placed stationary on a Teflon plate. The spacing between the anode cell and the cathode cell used in the electrolysis evaluation was adjusted to about 3 cm. The stationary layered article was lifted and the operation of inserting and holding the layered article between them was carried out. This operation was performed by checking the electrode for displacement and drop.

[1444] (B) The laminated article was placed stationary on the Teflon plate in the same manner as in the above item (A). Two adjacent corners of a portion of the membrane in the laminate were held by hands while lifting the laminate so that it was vertical. The membrane, held by hands at two adjacent corners, was moved from this state, bringing them close to each other so that the membrane protruded or recessed. This operation was repeated again to check the adherence of the electrode to the membrane. The results were evaluated on a four-point scale from 1 to 4 based on the following indicators:

1: good workability

2: usable

3: operation is difficult

4: essentially unserviceable

Here, with respect to the samples of Examples 3-4 and 3-6, the samples having the same size as the size of the large electrolytic cell were also subjected to processability evaluation as mentioned below. The results of the evaluation of Examples 3-4 and 3-6 were used as indicators to evaluate the difference between the score of the above items (A) and (B) and the score of the large sample. That is, in the case where the evaluation result of the small-sized laminate was "1" or "2", it was judged that no workability problems arise even if the laminate was formed at a large size.

[1445] (3) Proportion of anchorage area

The surface area of the electrolysis electrode opposite the ion exchange membrane (the entire area corresponding to the conductive surface and the area corresponding to the non-conductive surface) was calculated as the area S1. Then, the area of the electrode for electrolysis was calculated as the area S2. The areas S1 and S2 were identified with the area of the ion exchange membrane and electrolysis electrode laminate when viewed from the side of the electrolysis electrode (see Figure 57). With regard to the shape of the electrolysis electrode, even the electrode having holes (lumens) had an open porosity ratio of less than 90%. Thus, the electrode for electrolysis was considered as a flat plate (the area of the holes had to be included in the mentioned area).

The area S3 of the fixing region was also identified as an area when the laminate was viewed from above, as in FIG. 57 (the same applies to the area of the area corresponding only to the conductive surface S '). In the case where the PTFE tape mentioned below has been fixed as a fastener, the overlapping area with the tape should not be included in the mentioned area. Alternatively, in the case where the below mentioned PTFE yarns and adhesive were fixed as fasteners, the area on the back sides of the electrode and membrane was included in said area.

As described above, the value 100 × (S3 / S1) was calculated as the fraction α of the attachment area (%) relative to the surface area opposite the electrolysis electrode in the ion exchange membrane. In addition, the value 100 × S3 '/ S2 was calculated as the proportion of the β region corresponding only to the conductive surface of the attachment region relative to the conductive surface area.

[1446] [Example 3-1]

As an electrode substrate for a cathode in electrolysis, an electrolytic nickel foil having a measured thickness of 22 µm was obtained. One surface of this nickel foil was roughened by electrolytic nickel plating. The arithmetic average Ra of the roughness of the rough surface was 0.96 μm. The surface roughness measurement was performed under the same conditions as in the case of the surface roughness measurement of the blasted nickel plate.

A porous foil was formed by punching this nickel foil into circular holes by punching. The open porosity ratio was 44%.

[1447] A cover fluid for use in forming an electrode catalyst was prepared according to the following procedure. Solutions of ruthenium nitrate having a ruthenium concentration of 100 g / L (from FURUYA METAL Co., Ltd.) and cerium nitrate (from KISHIDA CHEMICAL Co., Ltd.) were mixed so that the molar ratio between ruthenium and cerium was 1: 0.25. This mixed solution was thoroughly mixed and used as a covering liquid for the cathode.

The bath containing the above coating liquid was placed in the lowest position of the roller coater. The vat was positioned such that a coating roll obtained by winding a closed cell type EPDM sponge rubber (INOAC CORPORATION, E-4088, 10 mm thick) around a polyvinyl chloride (PVC) cylinder was always in contact with the casing fluid. A roller for coating, around which the same EPDM was wound, was placed on its upper part, and a PVC roller was additionally placed above it. The coating liquid was applied in such a way that the electrode substrate was passed between the second coating roller and the PVC roller in the uppermost position (roller coating method). Then, after drying at 50 ° C for 10 minutes, pre-firing at 150 ° C for 3 minutes and firing at 350 ° C for 10 minutes were carried out. A series of these operations of coating, drying, pre-baking and baking were repeated until a predetermined coating value was reached. The thickness of the electrode made in Example 3-1 was 24 µm. The thickness of the catalytic layer containing ruthenium oxide and cerium oxide, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 8 µm. A coating was also formed on a surface that was not roughened.

The electrode obtained by the above method was cut into pieces of 95 mm in length and 110 mm in width to evaluate the performance of electrolysis. The roughened electrode surface was positioned opposite the substantially central position of the side of the carboxylic acid layer of the ion exchange membrane (size: 160 mm × 160 mm) equilibrated with aqueous 0.1N. NaOH solution.

PTFE tape (manufactured by NITTO DENKO CORPORATION) was used to secure the four sides so that the ion exchange membrane and electrode were routed as shown in Figure 57 (note that Figure 57 is a schematic view for illustration purposes only, and dimensions are not necessarily The same is true for the following figures). In Example 3-1, the PTFE tape was the fastener, the α fraction was 60% and the β fraction was 1.0%.

Even when the four corners of the membrane portion of the membrane-combined electrode, which was obtained by combining the membrane with the electrode, were clamped and suspended so that the membrane-integrated electrode was parallel to the base so that the electrode was facing toward the base, the electrode did not detach or move. In addition, when both ends of one side were clamped and suspended so that the membrane-integrated electrode was perpendicular to the base, the electrode did not detach or move.

The above membrane-integrated electrode was interposed between the anode cell and the cathode cell so that the surface to which the electrode was attached was facing the cathode chamber side. In a sectional structure, a down conductor, a mat, a nickel mesh as a supply conductor, an electrode, a membrane, and an anode were placed in this order from the side of the cathode chamber to form a structure with a zero gap.

The resulting electrode was tested for electrolysis performance. The results are shown in Table 5.

The electrode exhibited low voltage and high current efficiency. Manufacturability was also good: "2".

[1448] [Example 3-2]

Evaluation was performed in the same manner as in Example 3-1, except for the increase in the area covered by the PTFE tape on the electrolytic surface, as shown in Figure 58. That is, in Example 3-2, the area of the PTFE tape was increased in the direction of the electrode plane for electrolysis, and thus the electrolytic surface area in the electrode for electrolysis was less than in Example 3-1. In Example 3-2, the α fraction was 69% and the β fraction was 23%. The results of the assessment are shown in Table 5.

The electrode exhibited low voltage and high current efficiency. Manufacturability was also good: "1".

[1449] [Example 3-3]

Evaluation was performed in the same manner as in Example 3-1, except for increasing the area over which the PTFE tape overlapped the electrolytic surface, as shown in Figure 59. That is, in Example 3-3, the area of the PTFE tape was increased in the direction of the electrode plane for electrolysis, and thus the electrolytic surface area in the electrode for electrolysis was less than in Example 3-1. In Example 3–3, the α fraction was 87% and the β fraction was 67%. The results of the assessment are shown in Table 5.

The electrode exhibited low voltage and high current efficiency. Manufacturability was also good: "1".

[1450] [Example 3-4]

To evaluate the characteristics of electrolysis, an electrode identical to the electrode of Example 3-1 was obtained and cut into fragments measuring 95 mm in length and 110 mm in width. The roughened electrode surface was positioned opposite the substantially central position of the side of the carboxylic acid layer of the ion exchange membrane (size: 160 mm × 160 mm) equilibrated with aqueous 0.1N. NaOH solution. The PTFE yarn was used to stitch the electrode from its left side in the vertical direction to the ion exchange membrane, as shown in Figure 60. The PTFE yarn was passed through a section at a distance of 10 mm in the vertical direction and a distance of 10 mm in the horizontal direction from the corner of the electrode, from the back side of the sheet in figure 60 to its front side, so that it runs through the section at a distance of 35 mm in the vertical direction and at a distance of 10 mm in the horizontal direction from the front side of the sheet to the back side, passes through the section at a distance of 60 mm in the vertical direction and at a distance of 10 mm in the horizontal direction again from the back side of the sheet to the front side, and passed through the section at a distance of 85 mm in the vertical direction and at a distance of 10 mm in the horizontal direction from the front side of the sheet to its back side. On the areas where the yarn passed through the ion-exchange membrane, a solution obtained by dispersing an acid-type resin S was applied, which was a copolymer of CF ₂ = CF ₂ and CF ₂ = CFOCF ₂ CF (CF ₂ ) OCF ₂ CF ₂ SO ₂ F and had ion-exchange capacity 1.03 mg-eq / g, with a content of 5% by weight in ethanol.

As described above, in Example 3-4, the α proportion was 0.35% and the β proportion was 0.86%.

Even when the four corners of the membrane-combined electrode portion, which was obtained by the membrane-electrode combination, were clamped and suspended so that the membrane-integrated electrode was parallel to the base so that the electrode was facing toward the base, the electrode did not fall off. In addition, when both ends of one side were clamped and suspended so that the membrane-integrated electrode was perpendicular to the base, the electrode did not detach.

The resulting electrode was evaluated. The results are shown in Table 5.

The electrode exhibited low voltage and high current efficiency. Manufacturability was also good: "2".

[1451] In addition, in Example 3-4, each element of an ion exchange membrane and an electrode was formed with a large size. An ion exchange membrane was obtained having a size of 1.5 m in length and 2.5 m in width, and four cathodes having a size of 0.3 m in length and 2.4 m in width. The cathodes were placed without any gap on the side of the carboxylic acid layer of the ion exchange membrane, and the cathodes were attached to the ion exchange membrane with PTFE yarn to form a layered article. In this Example, the α proportion was 0.013% and the β proportion was 0.017%.

When the operation of equipping a large electrolyzer with a membrane-integrated electrode, which was formed by connecting a membrane with an electrode, was performed, it was possible to achieve a problem-free installation.

[1452] [Example 3-5]

Received an electrode identical to the electrode in Example 3-1, and cut into pieces measuring 95 mm in length and 110 mm in width to evaluate the performance of electrolysis. The roughened electrode surface was positioned opposite the substantially central position of the side of the carboxylic acid layer of the ion exchange membrane (size: 160 mm × 160 mm) equilibrated with aqueous 0.1N. NaOH solution. To secure the ion exchange membrane to the electrode, a fixing resin made of polypropylene was used as shown in Figure 61. That is, the resin was placed in a total of two positions: at a site 20 mm in the vertical direction and at a distance of 20 mm in the horizontal direction from the corner of the electrode. and additionally on an area at a distance of 20 mm in the vertical direction and at a distance of 20 mm in the horizontal direction from the corner below it. A solution similar to the solution in Example 3-4 was applied to the areas where the fixing resin passed through the ion exchange membrane.

As described above, in Example 3-5, the fixing resin and the S resin served as fasteners, the α ratio was 0.47% and the β ratio was 1.1%.

Even when the four corners of the membrane-combined electrode portion, which was obtained by the membrane-electrode combination, were clamped and suspended so that the membrane-integrated electrode was parallel to the base so that the electrode was facing toward the base, the electrode did not fall off. In addition, when both ends of one side were clamped and suspended so that the membrane-integrated electrode was perpendicular to the base, the electrode did not detach.

The resulting electrode was evaluated. The results are shown in Table 5.

The electrode exhibited low voltage and high current efficiency. Manufacturability was also good: "2".

[1453] [Example 3-6]

Received an electrode identical to the electrode in Example 3-1, and cut into pieces measuring 95 mm in length and 110 mm in width to evaluate the performance of electrolysis. The roughened electrode surface was positioned opposite the substantially central position of the side of the carboxylic acid layer of the ion exchange membrane (size: 160 mm × 160 mm) equilibrated with aqueous 0.1N. NaOH solution. As shown in Figure 62, cyanoacrylate adhesive (trade name: Aron Alpha, TOAGOSEI CO., LTD.) Was used to secure the ion exchange membrane and electrode. That is, the membrane and the electrode were glued together at five points on the vertical side of the electrode (the points in each case were equidistant from each other) and eight points on the horizontal side of the electrode (the points in each case were equidistant from each other).

As described above, in Example 3-6, the adhesive served as fasteners, the α proportion was 0.78% and the β proportion was 1.9%.

Even when the four corners of the membrane-combined electrode portion, which was obtained by the membrane-electrode combination, were clamped and suspended so that the membrane-integrated electrode was parallel to the base so that the electrode was facing toward the base, the electrode did not fall off. In addition, when both ends of one side were clamped and suspended so that the membrane-integrated electrode was perpendicular to the base, the electrode did not detach.

The resulting electrode was evaluated. The results are shown in Table 5.

The electrode exhibited low voltage and high current efficiency. Manufacturability was also good: "1".

[1454] In addition, in Example 3-6, each element of the ion exchange membrane and electrode was formed with a large size. An ion exchange membrane was obtained having a size of 1.5 m in length and 2.5 m in width, and four cathodes having a size of 0.3 m in length and 2.4 m in width. The edges of one horizontal side of each of the four cathodes were joined together with the aforementioned glue to form a large cathode (1.2 m long and 2.4 m wide). This large cathode was connected to the central region on the side of the carboxylic acid layer of the ion exchange membrane using Aron Alpha to form a laminated body. That is, the membrane and the electrode were bonded with glue at five points on the vertical side of the electrode (the points in each case were at an equal distance from each other) and eight points on the horizontal side of the electrode (the points in each case were at an equal distance from each other), the same in a manner similar to FIG. 62. In this Example, the α proportion was 0.019% and the β proportion was 0.024%.

When the operation of equipping a large electrolyzer with a membrane-integrated electrode, which was formed by connecting a membrane with an electrode, was performed, it was possible to achieve a problem-free installation.

[1455] [Example 3-7]

Received an electrode identical to the electrode in Example 3-1, and cut into pieces measuring 95 mm in length and 110 mm in width to evaluate the performance of electrolysis. The roughened electrode surface was positioned opposite the substantially central position of the side of the carboxylic acid layer of the ion exchange membrane (size: 160 mm × 160 mm) equilibrated with aqueous 0.1N. NaOH solution. To fix the ion exchange membrane and electrode, a solution similar to the solution in Example 3-4 was applied. That is, the resin was placed as a whole in two positions: at a site at a distance of 20 mm in the vertical direction and at a distance of 20 mm in a horizontal direction from the corner of the electrode, and, additionally, at a site at a distance of 20 mm in the vertical direction and at a distance of 20 mm along the horizontal direction from the corner below it (see Figure 61).

As described above, in Example 3-7, resin S served as fasteners, the α proportion was 2.0% and the β proportion was 4.8%.

Even when the four corners of the membrane-combined electrode portion, which was obtained by the membrane-electrode combination, were clamped and suspended so that the membrane-integrated electrode was parallel to the base so that the electrode was facing toward the base, the electrode did not fall off. In addition, when both ends of one side were clamped and suspended so that the membrane-integrated electrode was perpendicular to the base, the electrode did not detach.

The resulting electrode was evaluated. The results are shown in Table 5.

The electrode exhibited low voltage and high current efficiency. Manufacturability was also good: "2".

[1456] [Comparative Example 3-1]

Evaluation was performed in the same manner as in Example 3-1, except for increasing the area over which the PTFE tape overlapped the electrolytic surface, as shown in Figure 59. That is, in Comparative Example 3-1, the area of the PTFE tape was increased in the plane direction electrode for electrolysis, and thus the electrolytic surface area in the electrode for electrolysis was smaller than in Example 3-1. In Comparative Example 3-1, the α proportion was 93% and the β proportion was 83%. The results of the assessment are shown in Table 5.

The electrode exhibited low voltage and high current efficiency. Manufacturability was also good: "1".

[1457] [Comparative Example 3-2]

Evaluation was performed in the same manner as in Example 3-1, except for an increase in the area over which the PTFE tape overlapped the electrolytic surface. The evaluation results are shown in Table 5. That is, in Comparative Example 3-2, the area of the PTFE tape was increased in the direction of the plane of the electrolysis electrode.

In Comparative Example 3-2, the α proportion and β proportion were 100%, and the entire electrolytic surface was a PTFE-coated attachment area. Accordingly, it was impossible to supply an electrolyte solution, and thus it was impossible to perform electrolysis. Manufacturability was good: "1".

[1458] [Comparative Example 3-3]

The evaluation was carried out in the same manner as in Example 3-1, except that no PTFE tape was used, that is, the proportion of α and the proportion of β was 0%. The results of the assessment are shown in Table 5.

The electrode exhibited low voltage and high current efficiency. Meanwhile, since there was no anchorage area for the membrane and the electrode, it was impossible to manipulate (handle) the membrane and the electrode as a laminated article (combined piece), and thus the workability was "4".

[1459] The evaluation results of Examples 3-1 to 7 and Comparative Examples 3-1 to 3 are also shown below in Table 5.

[1460]

[Table 5]

Membrane area Electrode support area for electrolysis Docking area area The area of the fixing area corresponding to the conductive surface only Fraction α Fraction β Manufacturability (sensory assessment) Evaluation of electrolysis performance S1 S2 S3 S3 ' 100 * S3 / S1 (%) 100 * S3 '/ S2 (%) Voltage (V) Current output (%) Example 3-1 256 104.5 153 1.0 60 1.0 2 2.98 97.8 Example 3-2 256 104.5 176 24 69 23 one 3.11 97.7 Example 3-3 256 104.5 222 70 87 67 one 3.85 96.1 Example 3-4 256 104.5 0.90 0.90 0.35 0.86 2 2.99 92.2 Example 3-5 256 104.5 1,2 1,2 0.47 1.1 2 3.00 92.5 Example 3-6 256 104.5 2.0 2.0 0.78 1.9 2 2.97 97.5 Example 3-7 256 104.5 5.0 5.0 2.0 4.8 2 2.99 97.0 Comparative Example 3-1 256 104.5 239 87 93 83 one 5.50 86.8 Comparative Example 3-2 256 104.5 256 104.5 one hundred one hundred one Impossible to carry out electrolysis Comparative Example 3-3 256 104.5 0 0 0 0 four 2.97 97.5

[1461] <Checking the fourth embodiment>

As will be described below, Experimental Examples according to the fourth embodiment are presented (in the section <Verification of the fourth embodiment>, below, simply referred to as “Examples”) and Experimental Examples not corresponding to the fourth embodiment (in the section <Verification of the fourth embodiment>, hereinafter simply referred to as "Comparative Examples"), and evaluated by the following method. Details will be described with reference to Figures 79-90 as appropriate.

[1462] [Evaluation Method]

(1) Coefficient of open porosity

The electrode was cut into fragments of 130 mm × 100 mm. A digital thickness gauge (Mitutoyo Corporation, minimum scale 0.001 mm) was used to calculate the average of 10 points measured uniformly over the plane. The value was used as the thickness of the electrode (measured thickness) to calculate the volume. Thereafter, an electronic balance was used to measure the mass. From the specific gravity of each metal (specific gravity of nickel = 8.908 g / cm ³ , specific gravity of titanium = 4.506 g / cm ³ ), the coefficient of open porosity or the coefficient of voidness was calculated.

Open porosity ratio (void ratio) (%) = (1– (electrode mass) / (electrode volume × specific gravity of metal)) × 100

[1463] (2) Mass per unit area (mg / cm ² )

The electrode was cut into pieces of 130 mm × 100 mm and its mass was measured on an electronic balance. The value was divided by the area (130 mm x 100 mm) to calculate the mass per unit area.

[1464] (3) Force applied per unit mass · unit area (1) (adhesion force) (N / (mg · cm ² ))

[Method (i)]

For measurement, a tensile and compression machine (manufactured by Imada-SS Corporation, main testing machine: tensile and compression testing machine SDT-52NA type, load cell: load cell type SL-6001) was used.

[1465] A 200 mm square nickel plate having a thickness of 1.2 mm was blasted with 320 grit alumina. The arithmetic average (Ra) of the surface roughness of the nickel plate after blasting was 0.7 µm. Here, to measure the surface roughness, an SJ-310 probe-type surface roughness meter (profilometer) (Mitutoyo Corporation) was used. The sample to be measured was placed on the plate surface parallel to the ground surface to measure the arithmetic mean of the roughness Ra under the conditions described below. The measurement was repeated 6 times and the average was taken.

[1466] <Probe shape> apex taper angle = 60 °, tip radius = 2 µm, static measuring force = 0.75 mN.

<Roughness Standard> JIS2001

<Evaluation curve> R

<Filter> GAUSS

<Limit value λc> 0.8 mm

<Limit value λs> 2.5 µm

<Number of sections> 5

<Pre-pass, additional pass> available

This nickel plate was mounted vertically on the bottom grip of a tensile and compression machine.

[1467] The ion-exchange membrane A described below was used as a membrane.

Monofilaments with a size of 90 denier made of polytetrafluoroethylene (PTFE) (hereinafter referred to as PTFE yarns) were used as reinforcing materials of the core. The consumable yarns were yarns obtained by twisting 200 times / meter of six 35 denier polyethylene terephthalate (PET) filaments (hereinafter referred to as PET yarns). First, in each of the TD- and MD-directions, a plain weaving of PTFE yarns and consumable yarns with 24 PTFE yarns / inch was performed so that two consumable yarns were placed between adjacent PTFE yarns to obtain a woven fabric. The resulting woven fabric was subjected to roller compaction to obtain a woven fabric having a thickness of 70 µm.

Then resin A was obtained in the form of a dry resin, which was a copolymer of CF ₂ = CF ₂ and CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ COOCH ₃ and had an ion exchange capacity of 0.85 mg-eq / g, and the resin B in the form of a dry resin, which was a copolymer of CF ₂ = CF ₂ and CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₂ F and had an ion exchange capacity of 1.03 mg⋅eq / g.

Using these resins A and B, a two-layer film X in which the thickness of the resin layer A was 15 µm and the thickness of the resin layer B was 104 µm was obtained by a flat die coextrusion method.

Then release paper (having embossing with a conical shape with a height of 50 μm), reinforcing material and film X were laminated in this order on a hot plate having a heat source and a vacuum source inside and having micropores on its surface, heated and depressurized under surface temperature conditions hot plate 223 ° C and a reduced pressure value of 0.067 MPa for 2 minutes, and then remove the release paper to obtain a composite membrane.

The resulting composite membrane was immersed in an aqueous solution heated to 80 ° C. containing 30% by weight of dimethyl sulfoxide (DMSO) and 15% by weight of potassium hydroxide (KOH) for 20 minutes for saponification. Then the composite membrane was immersed in an aqueous 0.5N hydrochloric acid heated to 50 ° C. sodium hydroxide solution (NaOH) for one hour to replace the counterion of the ion exchange group with Na, and then washed with water. Then the membrane was dried at 60 ° C.

In addition, 20% by mass of zirconium oxide having a primary particle size of 1 μm was added to an ethanol solution with a concentration of 5% by mass of resin B as an acidic resin and dispersed to obtain a slurry, and the slurry was sprayed onto both surfaces of the above composite membrane. the method of spraying a suspension with the formation of coatings of zirconium oxide on the surfaces of the composite membrane to obtain an ion-exchange membrane A. The density of the coating of zirconium oxide, measured by X-ray fluorescence analysis, was 0.5 mg / cm ² . The average particle size was measured with a particle size analyzer (manufactured by SHIMADZU CORPORATION, "SALD (R) 2200").

The obtained above ion exchange membrane (membrane) was immersed in pure water for 12 hours or more and then used for testing. The membrane was brought into contact with the aforementioned nickel plate completely moistened with pure water and adhered by the surface tension of the water. At this time, the nickel plate and the ion exchange membrane were positioned so that their upper ends coincided.

[1468] A sample of an electrolysis electrode (electrode) used for measurement was cut to form a piece in the form of a square with a side of 130 mm. Ion exchange membrane A was cut to form a 170 mm square fragment. One side of the electrode was sandwiched between two stainless steel plates (thickness: 1 mm, length: 9 mm, width: 170 mm). After positioning so that the center of the stainless steel plates was aligned with the center of the electrode, four clamps were used to secure the electrode and plates evenly. The stainless steel plates in the center were clamped by the upper clamp of the tensile and compression machine while the electrode was suspended. The load applied by the testing machine at this time was set to 0 N. The combined assembly of stainless steel plates, electrode, and clamps was temporarily removed from the tensile and compressive testing machine and immersed in a bath containing clean water to sufficiently moisten electrode with clean water. Thereafter, the stainless steel plates in the center were again clamped with the upper clamp of the tensile and compression machine while the electrode was suspended.

The upper clamp of the tensile and compressive testing machine was lowered and the sample of the electrolysis electrode was adhered to the surface of the ion exchange membrane by the surface tension of pure water. The size of the engagement surface at this time was 130 mm long and 110 mm wide. The entire electrode and the ion-exchange membrane were sprayed with clean water from a wash bottle in order to sufficiently moisten the membrane and electrode again. Thereafter, a roll formed by winding a 5 mm thick EPDM sponge rubber around a vinyl chloride pipe (outer diameter: 38 mm) was rolled from top to bottom while lightly pressing against the electrode to remove excess pure water. Rolling was carried out only once.

[1469] The electrode was lifted at a speed of 10 mm / minute to start measuring the load, and the load was recorded when the size of the overlapping area of the electrode and membrane reached 130 mm wide and 100 mm long. This measurement was repeated three times and the average was calculated.

This average value was divided by the area of the overlapping area of the electrode and ion-exchange membrane and by the mass of the electrode in the overlap area with the ion-exchange membrane to calculate the force applied per unit mass · unit area (1). The mass of the electrode in the overlapping portion with the ion exchange membrane was determined by proportional division from the value obtained in the above section (2) Mass per unit area (mg / cm ² ).

With regard to the environment in the measurement chamber, the temperature was 23 ± 2 ° C and the relative humidity was 30 ± 5%.

The electrode used in the Examples and Comparative Examples was able to hold on its own and adhere without sliding down or peeling when it was adhered to an ion exchange membrane that was adhered to a vertically fixed nickel plate under surface tension.

A schematic view of the method for evaluating the applied force (1) is shown in FIG. 79.

The lower limit of the tensile testing machine was 0.01 (N).

[1470] (4) Force applied per unit mass · unit area (2) N / (mg · cm ² ) (adhesion force)

[Method (ii)]

For measurement, a tensile and compression machine (manufactured by Imada-SS Corporation, main testing machine: tensile and compression testing machine SDT-52NA type, load cell: load cell type SL-6001) was used.

A nickel plate, identical to the one in Method (i), was mounted vertically on the bottom clamp of a tensile and compression machine.

A sample of the electrolysis electrode (electrode) used for measurement was cut to form a piece in the form of a square with a side of 130 mm. Ion exchange membrane A was cut to form a 170 mm square fragment. One side of the electrode was sandwiched between two stainless steel plates (thickness: 1 mm, length: 9 mm, width: 170 mm). After positioning so that the center of the stainless steel plates was aligned with the center of the electrode, four clamps were used to evenly secure the electrode and the plates. The stainless steel plates in the center were clamped by the upper clamp of the tensile and compression machine while the electrode was suspended. The load applied by the testing machine at this time was set to 0 N. The combined assembly of stainless steel plates, electrode, and clamps was temporarily removed from the tensile and compressive testing machine and immersed in a bath containing clean water to sufficiently moisten electrode with clean water. Thereafter, the stainless steel plates in the center were again clamped with the upper clamp of the tensile and compression machine while the electrode was suspended.

[1471] The upper clamp of the tensile and compression machine was lowered and the electrolysis electrode sample adhered to the surface of the nickel plate by the surface tension of the solution. The size of the engagement surface at this time was 130 mm long and 110 mm wide. The entire electrode and the nickel plate were sprayed with clean water from a wash bottle to sufficiently wet the nickel plate and electrode again. Thereafter, a roll formed by winding a 5 mm thick EPDM spongy rubber around a vinyl chloride tube (outer diameter: 38 mm) was rolled from top to bottom while lightly pressing against the electrode to remove excess solution. Rolling was carried out only once.

The electrode was lifted at a speed of 10 mm / minute to start measuring the load, and the load was recorded when the size of the overlapping area of the electrode and the nickel plate in the longitudinal direction reached 100 mm. This measurement was repeated three times and the average was calculated.

This average value was divided by the area of the overlapping area of the electrode and the nickel plate and by the mass of the electrode in the overlapping area with the nickel plate to calculate the force applied per unit mass · unit area (2). The mass of the electrode in the membrane overlap portion was determined by proportional division from the value obtained in the above section (2) Mass per unit area (mg / cm ² ).

With regard to the environment in the measurement chamber, the temperature was 23 ± 2 ° C and the relative humidity was 30 ± 5%.

The electrode used in the Examples and Comparative Examples was capable of self-adhesion and adhesion without sliding down or peeling when adhered to the vertically supported nickel plate under surface tension.

The lower limit of the tensile testing machine was 0.01 (N).

[1472] (5) Method for evaluating winding around a string with a diameter of 280 mm (1) (%)

(Membrane and Column)

Evaluation method (1) was carried out according to the following procedure.

The ion exchange membrane A (membrane) obtained in [Method (i)] was cut to form a 170 mm square piece. The ion exchange membrane was immersed in pure water for 12 hours or more and then used for testing. In Comparative Examples 33 and 34, the electrode was hot-pressed with the ion exchange membrane, and thereby a combined ion exchange membrane and electrode unit (130 mm square electrode) was obtained. After the ion exchange membrane was completely immersed in pure water, the membrane was placed on the curved surface of a plastic (polyethylene) pipe having an outer diameter of 280 mm. Thereafter, the excess solution was removed with a roller formed by winding a 5 mm thick EPDM sponge rubber around a vinyl chloride pipe (outer diameter: 38 mm). The roll was rolled over the ion exchange membrane from left to right in the schematic view shown in FIG. 80. The roll was carried out only once. One minute thereafter, the proportion of the portion where the ion exchange membrane came into intimate contact with the plastic electrode tube having an outer diameter of 280 mm was measured.

[1473] (6) Method for evaluating the winding around a string with a diameter of 280 mm (2) (%)

(Membrane and electrode)

Evaluation method (2) was carried out according to the following procedure.

The ion exchange membrane A (membrane) obtained in [Method (i)] was cut to form a 170 mm square fragment, and the electrode was cut to form a 130 mm square fragment. The ion exchange membrane was immersed in pure water for 12 hours or more and then used for testing. The ion exchange membrane and electrode were completely immersed in pure water and then layered. This layered product was placed on a curved surface of a plastic (polyethylene) pipe having an outer diameter of 280 mm with the electrode on the outside. Thereafter, a roll formed by winding a 5 mm thick EPDM sponge rubber around a vinyl chloride tube (outer diameter: 38 mm) was rolled over the ion exchange membrane from left to right in the schematic view shown in FIG. 81, pressing lightly on the electrode to remove excess solution. Rolling was carried out only once. One minute thereafter, the proportion of the area where the ion exchange membrane was brought into close contact with the electrode was measured.

[1474] (7) Method for evaluating the winding around a string with a diameter of 145 mm (3) (%)

(Membrane and electrode)

Evaluation method (3) was carried out according to the following procedure.

The ion exchange membrane A (membrane) obtained in [Method (i)] was cut to form a 170 mm square fragment, and the electrode was cut to form a 130 mm square fragment. The ion exchange membrane was immersed in pure water for 12 hours or more and then used for testing. The ion exchange membrane and electrode were completely immersed in pure water and then layered. This layered product was placed on a curved surface of a plastic (polyethylene) pipe having an outer diameter of 145 mm with the electrode on the outside. Thereafter, a roll formed by winding a 5 mm thick EPDM sponge rubber around a vinyl chloride tube (outer diameter: 38 mm) was rolled from left to right in the schematic view shown in FIG. 82 while lightly pressing the electrode to remove excess solution. Rolling was carried out only once. One minute thereafter, the proportion of the area where the ion exchange membrane was brought into close contact with the electrode was measured.

[1475] (8) Manufacturability (reaction evaluation)

(A) The ion exchange membrane A (membrane) obtained in [Method (i)] was cut to form a 170 mm square piece, and the electrode was cut into pieces of 95 × 110 mm. The ion exchange membrane was immersed in pure water for 12 hours or more and then used for testing. In each Example, the ion-exchange membrane and the electrode were completely immersed in three solutions: aqueous sodium bicarbonate solution, aqueous 0.1 N. NaOH solution and pure water, then layered and placed stationary on a Teflon plate. The spacing between the anode cell and the cathode cell used in the electrolysis evaluation was adjusted to about 3 cm. The stationary layered article was lifted and the operation of inserting and holding the layered article between them was carried out. This operation was performed by checking the electrode for displacement and drop.

[1476] (B) The ion exchange membrane A (membrane) obtained in [Method (i)] was cut to form a 170 mm square piece, and the electrode was cut into pieces of 95 × 110 mm. The ion exchange membrane was immersed in pure water for 12 hours or more and then used for testing. In each Example, the ion-exchange membrane and the electrode were completely immersed in three solutions: aqueous sodium bicarbonate solution, aqueous 0.1 N. NaOH solution and pure water, then layered and placed stationary on a Teflon plate. Two adjacent corners of a portion of the membrane in the laminate were held by hands while lifting the laminate so that it was vertical. The membrane, held by hands at two adjacent corners, was moved from this state, bringing them close to each other so that the membrane protruded or recessed. This movement was repeated again to check the adherence of the electrode to the membrane. The results were evaluated on a four-point scale from 1 to 4 based on the following indicators:

1: good workability

2: usable

3: operation is difficult

4: Essentially unusable.

Here, the sample of Example 4-28, formed with a size equivalent to that of a large electrolytic cell including an electrode with a size of 1.3 mx 2.5 m and an ion exchange membrane with a size of 1.5 mx 2.8 m, was loaded and unloaded. The score of Example 28 ("3" as described below) was used as an indicator to evaluate the difference between the score of the above (A) and (B) and the score of the large sample. That is, in the case where the evaluation result of the small-sized laminate was "1" or "2", it was judged that no workability problems arise even if the laminate was formed at a large size.

[1477] (9) Evaluation of electrolysis characteristics (voltage (V), current efficiency (%), the total salt concentration of the caustic soda (mn ^-1, 50% based))

The electrolysis performance was evaluated in the following electrolysis experiment.

A titanium anode cell was placed opposite each other, having an anode chamber in which the anode (anode outlet cell) was formed, and a cathode cell having a nickel cathode chamber, in which a cathode (cathode outlet cell) was formed. A pair of seals was placed between the cells, and a layered article (a layered article of ion exchange membrane A and an electrolysis electrode) was inserted between the seals. Here, both the ion exchange membrane A and the electrolysis electrode were inserted between the seals. Then, the anode cell, seal, laminate, seal, and cathode were brought into intimate contact with each other to form an electrolytic cell, and an electrolyzer containing the cell was formed.

[1478] The anode was obtained by applying a mixed solution of ruthenium chloride, iridium chloride and titanium tetrachloride on a titanium substrate, subjected to blasting and acid etching as a pretreatment, followed by drying and firing. The anode was fixed in the anode chamber by welding. As the cathode, the cathode described in each of Examples and Comparative Examples was used. A nickel expanded metal sheet was used as a current collector of the cathode chamber. The down conductor was 95 mm long × 110 mm wide. As the metal elastic body, a mat formed by knitting a thin nickel wire was used. The mat as a metal elastic body was placed on the down conductor. A nickel mesh was placed on top of it, formed by a plain weave of nickel wire having a diameter of 150 μm and a mesh size of 40 mesh, and a Teflon (R) cord made of Teflon (R) was used to fix the four corners of the Ni – mesh to the down conductor. This Ni-grid was used as a supply conductor. This electrolytic cell has a zero-gap design utilizing the repulsive force generated by the mat like a metal resilient body. Seals made of ethylene-propylene-diene rubber (EPDM) were used as seals. The membrane used was an ion exchange membrane A (square with a side of 160 mm) obtained in [Method (i)].

[1479] The above electrolytic cell was used to perform conventional salt electrolysis. The brine concentration (sodium chloride concentration) in the anode chamber was adjusted to 205 g / L. The concentration of sodium hydroxide in the cathode compartment was set to 32% by weight. The temperature of each of the anode chamber and the cathode chamber was adjusted so that the temperature in each chamber could reach 90 ° C. Conventional salt electrolysis was carried out at a current density of 6 kA / m ² , measuring voltage, current efficiency and total salt concentration in caustic soda. The current efficiency here is the ratio of the amount of caustic soda formed to the passed current, and when impurity ions and hydroxide ions, rather than sodium ions, pass through the ion exchange membrane under the influence of the passed current, the current efficiency decreases. The current efficiency was obtained by dividing the number of moles of caustic soda formed during a given time by the number of moles of electrons of current passed during that time. The number of moles of caustic soda was obtained by separating the caustic soda formed during electrolysis into a plastic container and measuring its weight. Shown as the total salt concentration in caustic soda is the value obtained by converting the caustic soda concentration by 50%.

The technical characteristics of the electrode and supply conductor used in each of the Examples and Comparative Examples are shown in Table 6.

[1480] (11) Measurement of the thickness of the catalytic layer, the electrode substrate for electrolysis and the thickness of the electrode

A digital thickness gauge (manufactured by Mitutoyo Corporation, minimum scale 0.001 mm) was used to measure the thickness of the electrolysis electrode substrate by calculating an average of 10 points measured uniformly over the plane. This value was used as the thickness of the electrode substrate for electrolysis (measured thickness). A digital thickness gauge was used to measure the electrode thickness, calculating the average of 10 points, obtained by measuring uniformly over the plane, in the same way as for the electrode substrate. This value was used as the thickness of the electrode (measured thickness). The thickness of the catalytic layer was determined by subtracting the thickness of the electrolysis electrode substrate from the thickness of the electrode.

[1481] (12) Test of elastic deformation of an electrode

Each of the ion exchange membrane A (membrane) and the electrode obtained in [Method (i)] was cut to obtain a 110 mm square sample. The ion exchange membrane was immersed in pure water for 12 hours or more and then used for testing. Thereafter, the ion-exchange membrane and electrode were layered to obtain a laminated product under conditions of temperature: 23 ± 2 ° C and relative humidity: 30 ± 5%, the laminated product was wound around a PVC pipe having an outer diameter of φ32 mm and a length of 20 cm, without any or a gap as shown in Figure 83. The laminated product was secured using a polyethylene cable tie so that the laminated product could not separate from the PVC pipe or loosen. The laminated article was held in this state for 6 hours. After that, the cable tie was removed and the laminated product was unwound from the PVC pipe. Only the electrode was placed on the surface plate and the heights L ₁ and L _{2 of the} portion raised from the surface plate were measured to determine the average. This value was used as an indicator of electrode deformation. That is, a lower value means that the laminate is less likely to deform.

When expanded metal sheet was used, there were two winding directions: SW-direction and LW-direction. In this test, the laminate was wound in the SW direction.

Deformed electrodes (electrodes that did not return to their original state) were evaluated for softness after plastic deformation according to the method as shown in Figure 84. That is, the deformed electrodes were placed on a membrane completely immersed in pure water. One end of the electrode was fixed and the other raised end was pressed against the membrane to relieve the force, and it was judged whether the deformed electrode was in contact with the membrane.

[1482] (13) Assessment of membrane damage

The following ion exchange membrane B was used as a membrane.

As the reinforcing materials of the core, materials obtained by twisting 900 times / meter of 100 denier polytetrafluoroethylene (PTFE) filaments in the form of filaments (hereinafter referred to as PTFE yarns) were used. As the warp yarns consumable, yarns obtained by twisting 200 times / meter of eight 35 denier polyethylene terephthalate (PET) filaments (hereinafter referred to as PET yarns) were used. As the weft consumable yarns, yarns obtained by twisting 200 times / meter of eight 35 denier polyethylene terephthalate (PET) filaments were used. First, plain weaving of PTFE yarns and consumable yarns was performed with 24 PTFE yarns / inch so that two consumable yarns were placed between adjacent PTFE yarns, resulting in a woven fabric having a thickness of 100 µm.

Then, polymer (A1) was obtained in the form of a dry resin, which was a copolymer of CF ₂ = CF ₂ and CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ COOCH ₃ and had an ion exchange capacity of 0.92 mg⋅eq / g, and polymer (B1) in the form of a dry resin, which was a copolymer of CF ₂ = CF ₂ and CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₂ F and had an ion exchange capacity of 1.10 mg⋅eq / g. Using these polymers (A1) and (B1), a two-layer film X in which the thickness of the polymer layer (A1) was 25 µm and the thickness of the polymer layer (B1) was 89 µm was obtained by a flat die coextrusion method. As the ion exchange capacity of each polymer, the ion exchange capacity was shown in the case of hydrolysis of the precursors of the ion exchange groups of each polymer for conversion to ion exchange groups.

Separately, polymer (B2) was obtained in the form of a dry resin, which was a copolymer of CF ₂ = CF ₂ and CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₂ F and had an ion exchange capacity of 1.10 mg-eq / g ... This polymer was obtained by single layer extrusion to obtain a Y film having a thickness of 20 μm.

Then release paper, film Y, reinforcing material and film X were laminated in this order on a hot plate having a heat source and a vacuum source inside and having micropores on its surface, heated and depressurized under conditions of a hot plate surface temperature of 225 ° C and a value of reduced pressure of 0.022 MPa for two minutes, and then the release paper was removed to obtain a composite membrane. The resulting composite membrane was immersed in an aqueous solution containing dimethyl sulfoxide (DMSO) and potassium hydroxide (KOH) for one hour to saponify. After that, the membrane was immersed in aqueous 0.5N hydrochloric acid. the NaOH solution for one hour to replace the ions attached to the ion-exchange groups with Na and then washed with water. Then the membrane was dried at 60 ° C.

In addition, polymer (B3) was hydrolyzed in the form of a dry resin, which was a copolymer of CF ₂ = CF ₂ and CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₂ F and had an ion exchange capacity of 1.05 mg-eq. / g, and then converted into an acid-type polymer with hydrochloric acid. Zirconium oxide particles having an average primary particle size of 0.02 μm were added to a mixed 50/50 (mass ratio) solution of water and ethanol in which polymer (B3 ') of this acidic type was dissolved in a proportion of 5% by mass so that the mass the ratio of polymer (B3 ') to zirconium oxide particles was 20/80. Thereafter, the polymer (B3 ') was dispersed in a slurry of zirconium oxide particles with a ball mill to obtain a slurry.

This suspension was sprayed onto both surfaces of an ion exchange membrane and dried to obtain an ion exchange membrane B having a coating layer containing polymer (B3 ') and zirconium oxide particles. The density of the zirconium oxide coating, measured by X-ray fluorescence analysis, was 0.35 mg / cm ² .

[1483] The anode used was the same as in section (9) Evaluation of electrolysis performance.

The cathode used was the cathode described in each of the Examples and Comparative Examples. The down conductor, mat and supply conductor of the cathode chamber used were the same as in section (9) Evaluation of electrolysis performance. That is, a zero-gap design was provided, using a Ni-grid as the supply conductor and the repulsive force that the mat creates as a metallic elastic body. The seals used were the same as in section (9) Evaluation of electrolysis performance. As the membrane, the ion-exchange membrane B obtained by the above method was used. That is, an electrolyzer equivalent to that shown in section (9) was formed, except that the laminated article of the ion exchange membrane B and the electrolysis electrode was interposed between the pair of seals.

[1484] The above electrolytic cell was used to perform ordinary salt electrolysis. The brine concentration (sodium chloride concentration) in the anode chamber was adjusted to 205 g / L. The concentration of sodium hydroxide in the cathode compartment was set to 32% by weight. The temperature of each of the anode chamber and the cathode chamber was adjusted so that the temperature in each chamber could reach 70 ° C. The electrolysis of common salt was carried out at a current density of 8 kA / m ² . The electrolysis was stopped 12 hours after the start of the electrolysis, and the ion exchange membrane B was removed and examined to assess the state of its damage.

"0" means no damage, "x" means that there is damage over substantially the entire surface of the ion exchange membrane.

[1485] (14) Ventilation resistance of the electrode

The ventilation resistance of the electrode was measured using a KES-F8 air permeability tester (trade name, KATO TECH CO., LTD.). The unit for ventilation resistance is kPa s / m. The measurement was repeated 5 times, and the average value is shown in Table 7. The measurement was carried out under the following conditions. The temperature of the measuring chamber was 24 ° C and the relative humidity was 32%.

Measurement condition 1 (ventilation resistance 1)

Piston speed: 0.2 cm / s

Purge volume: 0.4 cm ³ / cm ² / s

Measuring range: SENSE L (low)

Sample size: 50mm × 50mm

Measurement condition 2 (ventilation resistance 2)

Piston speed: 2 cm / s

Purge volume: 4 cm ³ / cm ² / s

Measuring range: SENSE M (medium) or H (high)

Sample size: 50mm × 50mm

[1486] [Example 4-1]

As an electrode substrate for a cathode in electrolysis, an electrolytic nickel foil having a measured thickness of 16 µm was obtained. One surface of this nickel foil was roughened by electrolytic nickel plating. The arithmetic mean Ra of the roughness of the rough surface was 0.71 μm. The surface roughness measurement was performed under the same conditions as in the case of the surface roughness measurement of the blasted nickel plate.

A porous foil was formed by punching this nickel foil into circular holes by punching. The open porosity ratio was 49%.

[1487] A cover fluid for use in forming an electrode catalyst was prepared according to the following procedure. Solutions of ruthenium nitrate having a ruthenium concentration of 100 g / L (from FURUYA METAL Co., Ltd.) and cerium nitrate (from KISHIDA CHEMICAL Co., Ltd.) were mixed so that the molar ratio between ruthenium and cerium was 1: 0.25. This mixed solution was thoroughly mixed and used as a covering liquid for the cathode.

The bath containing the above coating liquid was placed in the lowest position of the roller coater. The vat was positioned such that a coating roll obtained by winding a closed cell type EPDM sponge rubber (INOAC CORPORATION, E-4088, 10 mm thick) around a polyvinyl chloride (PVC) cylinder was always in contact with the casing fluid. A roller for coating, around which the same EPDM was wound, was placed on its upper part, and a PVC roller was additionally placed above it. The coating liquid was applied in such a way that the electrode substrate was passed between the second coating roller and the PVC roller in the uppermost position (roller coating method). Then, after drying at 50 ° C for 10 minutes, pre-firing at 150 ° C for 3 minutes and firing at 350 ° C for 10 minutes were carried out. A series of these operations of coating, drying, pre-baking and baking were repeated until a predetermined coating value was reached. The thickness of the electrode made in Example 4-1 was 24 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 8 µm. A coating was also formed on a surface that was not roughened. The thickness was the combined thickness of ruthenium oxide and cerium oxide.

The results of measuring the adhesion force of the electrode made by the above method are shown in Table 7. Sufficient adhesion force was observed.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 0 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less under measurement condition 1 and 0.0028 (kPa · s / m) under measurement condition 2.

[1488] The electrode obtained by the above method was cut into pieces of 95 mm in length and 110 mm in width to evaluate the performance of electrolysis. The roughened electrode surface was placed opposite the substantially central position of the side of the carboxylic acid layer of the ion exchange membrane A (size: 160 mm × 160 mm) obtained in [Method (i)] and equilibrated with aqueous 0.1N. NaOH solution, and ensured adhesion to it under the action of the surface tension of the aqueous solution.

Even when the four corners of the membrane portion of the membrane-combined electrode, which was obtained by combining the membrane with the electrode, were clamped and suspended so that the membrane-integrated electrode was parallel to the base so that the electrode was facing toward the base, the electrode did not detach or move. In addition, when both ends of one side were clamped and suspended so that the membrane-integrated electrode was perpendicular to the base, the electrode did not detach or move.

The above membrane-integrated electrode was interposed between the anode cell and the cathode cell so that the surface to which the electrode was attached was facing the cathode chamber side. In a sectional structure, a down conductor, a mat, a nickel mesh as a supply conductor, an electrode, a membrane, and an anode were placed in this order from the side of the cathode chamber to form a structure with a zero gap.

The resulting electrode was tested for electrolysis performance. The results are shown in Table 7.

The electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0".

When the amount of coating after electrolysis was measured by X-ray fluorescence analysis (XRF), substantially 100% of the coating remained on the surface that had been roughened, and the coating on the surface that had not been roughened was reduced. This shows that the surface opposite to the membrane (roughened surface) is involved in electrolysis, and other surfaces not opposite the membrane can achieve satisfactory electrolysis performance when the amount of coverage is small or no coating.

[1489] [Example 4-2]

In Example 4-2, an electrolytic nickel foil having a measured thickness of 22 µm was used as an electrode substrate for electrolysis at the cathode. One surface of this nickel foil was roughened by an electrolytic nickel plating process. The arithmetic average Ra of the roughness of the rough surface was 0.96 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. The open porosity ratio was 44%. Except as described above, the assessment was performed in the same manner as in Example 4-1, and the results are shown in Table 7.

The electrode thickness was 29 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 7 µm. The coating was also formed on a surface that was not roughened.

Sufficient traction was observed.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 0 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less under measurement condition 1 and 0.0033 (kPa · s / m) under measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0".

When the amount of coating after electrolysis was measured by XRF, substantially 100% of the coating remained on the surface that had been roughened, and the coating on the surface that had not been roughened was reduced. This shows that the surface opposite to the membrane (roughened surface) is involved in electrolysis, and other surfaces not opposite the membrane can achieve satisfactory electrolysis performance when the amount of coverage is small or no coating.

[1490] [Example 4-3]

In Example 4-3, an electrolytic nickel foil having a measured thickness of 30 μm was used as an electrode substrate for electrolysis at the cathode. One surface of this nickel foil was roughened by an electrolytic nickel plating process. The arithmetic mean Ra of the roughness of the rough surface was 1.38 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. The open porosity ratio was 44%. Except as described above, the assessment was performed in the same manner as in Example 4-1, and the results are shown in Table 7.

The electrode thickness was 38 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 8 µm. The coating was also formed on a surface that was not roughened.

Sufficient traction was observed.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 0 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less under measurement condition 1 and 0.0027 (kPa · s / m) under measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0".

When the amount of coating after electrolysis was measured by XRF, substantially 100% of the coating remained on the surface that had been roughened, and the coating on the surface that had not been roughened was reduced. This shows that the surface opposite to the membrane (roughened surface) is involved in electrolysis, and other surfaces not opposite the membrane can achieve satisfactory electrolysis performance when the amount of coverage is small or no coating.

[1491] [Example 4-4]

In Example 4-4, an electrolytic nickel foil having a measured thickness of 16 μm was used as an electrode substrate for electrolysis at the cathode. One surface of this nickel foil was roughened by an electrolytic nickel plating process. The arithmetic mean Ra of the roughness of the rough surface was 0.71 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. The open porosity ratio was 75%. Except as described above, the assessment was performed in the same manner as in Example 4-1, and the results are shown in Table 7.

The electrode thickness was 24 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 8 µm.

Sufficient traction was observed.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 0 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0023 (kPa · s / m) at measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0".

When the amount of coating after electrolysis was measured by XRF, substantially 100% of the coating remained on the surface that had been roughened, and the coating on the surface that had not been roughened was reduced. This shows that the surface opposite to the membrane (roughened surface) is involved in electrolysis, and other surfaces not opposite the membrane can achieve satisfactory electrolysis performance when the amount of coverage is small or no coating.

[1492] [Example 4-5]

In Example 4-5, an electrolytic nickel foil having a measured thickness of 20 μm was used as an electrode substrate for electrolysis at the cathode. Both surfaces of this nickel foil were roughened by an electrolytic nickel plating process. The arithmetic average Ra of the roughness of the rough surface was 0.96 μm. Both surfaces had the same roughness. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. The open porosity ratio was 49%. Except as described above, the assessment was performed in the same manner as in Example 4-1, and the results are shown in Table 7.

The electrode thickness was 30 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 10 µm. The coating was also formed on a surface that was not roughened.

Sufficient traction was observed.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 0 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0023 (kPa · s / m) at measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0".

In addition, when the amount of coating after electrolysis was measured by XRF, substantially 100% of the coating remained on both surfaces. By comparison with Examples 4-1 to 4-4, this shows that other surfaces not opposed to the membrane can achieve satisfactory electrolysis performance when the amount of coverage is small or no coating.

[1493] [Example 4-6]

In Example 4-6, the evaluation was performed in the same manner as in Example 4-1, except that the coating of the electrode substrate for electrolysis on the cathode was deposited by ion deposition, and the results are shown in Table 7. In ionic deposition, film formation was performed using a target from metallic Ru at a heating temperature of 200 ° C and in an argon / oxygen atmosphere, at a pressure for film formation of 7 × 10 ^–2 Pa. The formed coating was ruthenium oxide.

The electrode thickness was 26 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 10 µm.

Sufficient traction was observed.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 0 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less under measurement condition 1 and 0.0028 (kPa · s / m) under measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0".

[1494] [Example 4-7]

In Example 4-7, an electrode substrate for electrolysis at the cathode was prepared by an electrospinning method. The photomask had a shape formed by placing vertically and horizontally squares measuring 0.485 mm × 0.485 mm with an interval of 0.15 mm. Exposure, development, and electrodeposition were sequentially carried out to obtain a porous nickel foil having a measured thickness of 20 μm and an open porosity ratio of 56%. The arithmetic average Ra of the surface roughness was 0.71 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except as described above, the assessment was performed in the same manner as in Example 4-1, and the results are shown in Table 7.

The electrode thickness was 37 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 17 µm.

Sufficient traction was observed.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 0 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less under measurement condition 1 and 0.0032 (kPa · s / m) under measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0".

[1495] [Example 4-8]

In Example 4-8, an electrode substrate for electrolysis at the cathode was prepared by an electrospinning method. The substrate had a measured thickness of 50 μm and an open porosity ratio of 56%. The arithmetic average Ra of the surface roughness was 0.73 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except as described above, the assessment was performed in the same manner as in Example 4-1, and the results are shown in Table 7.

The electrode thickness was 60 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 10 µm.

Sufficient traction was observed.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 0 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less under measurement condition 1 and 0.0032 (kPa · s / m) under measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0".

[1496] [Example 4-9]

In Example 4-9, a nickel nonwoven fabric having a measured thickness of 150 µm and a void ratio of 76% (manufactured by NIKKO TECHNO, Ltd.) was used as an electrode substrate for cathode electrolysis. The nonwoven fabric had a nickel fiber diameter of 40 μm and a basis weight of 300 g / m ² . Except as described above, the assessment was performed in the same manner as in Example 4-1, and the results are shown in Table 7.

The electrode thickness was 165 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 15 µm.

Sufficient traction was observed.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 29 mm and the electrode did not return to its original flat state. Then, when evaluating the softness after plastic deformation, the electrode was adhered to the membrane under surface tension. Thus, it was found that the electrode was able to come into contact with the membrane with little force, even if the electrode had plastic deformation, and the electrode had satisfactory workability.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0612 (kPa · s / m) at measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. The electrode had a workability of "2" and was determined to be suitable for use as a large laminated article. Membrane damage was rated as good: "0".

[1497] [Example 4-10]

In Example 4-10, a nickel nonwoven fabric having a measured thickness of 200 µm and a void ratio of 72% (manufactured by NIKKO TECHNO, Ltd.) was used as an electrode substrate for cathode electrolysis. The nonwoven fabric had a nickel fiber diameter of 40 µm and a basis weight of 500 g / m ² . Except as described above, the assessment was performed in the same manner as in Example 4-1, and the results are shown in Table 7.

The electrode thickness was 215 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 15 µm.

Sufficient traction was observed.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 40 mm and the electrode did not return to its original flat state. Then, when evaluating the softness after plastic deformation, the electrode was adhered to the membrane under surface tension. Thus, it was found that the electrode was able to come into contact with the membrane with little force, even if the electrode had plastic deformation, and the electrode had satisfactory workability.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0164 (kPa · s / m) at measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. The electrode had a workability of "2" and was determined to be suitable for use as a large laminated article. Membrane damage was rated as good: "0".

[1498] [Example 4-11]

In Example 4-11, a porous nickel having a measured thickness of 200 µm and a void ratio of 72% (manufactured by Mitsubishi Materials Corporation) was used as an electrode substrate for cathode electrolysis. Except as described above, the assessment was performed in the same manner as in Example 4-1, and the results are shown in Table 7.

The electrode thickness was 210 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 10 µm.

Sufficient traction was observed.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 17 mm and the electrode did not return to its original flat state. Then, when evaluating the softness after plastic deformation, the electrode was adhered to the membrane under surface tension. Thus, it was found that the electrode was able to come into contact with the membrane with little force, even if the electrode had plastic deformation, and the electrode had satisfactory workability.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0402 (kPa · s / m) at measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. The electrode had a workability of "2" and was determined to be suitable for use as a large laminated article. Membrane damage was rated as good: "0".

[1499] [Example 4-12]

In Example 4-12, a 200 mesh nickel grid having a wire diameter of 50 μm, a measured thickness of 100 μm and an open porosity ratio of 37% was used as an electrode substrate for cathode electrolysis. Blasting was performed using 320 grit alumina. Blasting did not change the open porosity ratio. It was difficult to measure the surface roughness of the wire mesh. Then, in Example 4-12, a nickel plate having a thickness of 1 mm was simultaneously blasted during blasting, and the surface roughness of the nickel plate was taken as the surface roughness of the wire mesh. The arithmetic average Ra of the surface roughness was 0.64 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except as described above, the assessment was performed in the same manner as in Example 4-1, and the results are shown in Table 7.

The electrode thickness was 110 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 10 µm.

Sufficient traction was observed.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 0.5 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0154 (kPa · s / m) at measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good, like "1". Membrane damage was rated as good: "0".

[1500] [Example 4-13]

In Example 4-13, a 150 mesh nickel grid with a wire diameter of 65 µm, a measured thickness of 130 µm and an open porosity ratio of 38% was used as an electrode substrate for cathode electrolysis. Blasting was performed using 320 grit alumina. Blasting did not change the open porosity ratio. It was difficult to measure the surface roughness of the wire mesh. Then, in Example 4-13, a nickel plate having a thickness of 1 mm was simultaneously blasted during blasting and the surface roughness of the nickel plate was taken as the surface roughness of the wire mesh. The arithmetic average Ra of the surface roughness was 0.66 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except as described above, the evaluation was performed in the same manner as in Example 4-1 and the results are shown in Table 7.

The electrode thickness was 133 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 3 µm.

Sufficient traction was observed.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 6.5 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0124 (kPa · s / m) at measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. The electrode had a workability of "2" and was determined to be useful as a large laminated article. Membrane damage was also rated as good: "0".

[1501] [Example 4-14]

In Example 4-14, as the electrode substrate for electrolysis at the cathode, a substrate identical to that in Example 4-3 was used (measured thickness 30 µm and open porosity ratio 44%). The electrolysis performance was evaluated on a structure identical to that in Example 4-1, except that a nickel mesh was not used as the supply conductor. That is, in the sectional structure, the cell, the current collector, the mat, the electrode combined with the membrane, and the anode were placed in this order from the side of the cathode chamber to form a structure with a zero gap, and the mat served as a supply conductor. Except as described above, the evaluation was performed in the same manner as in Example 4-1 and the results are shown in Table 7.

Sufficient traction was observed.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 0 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less under measurement condition 1 and 0.0027 (kPa · s / m) under measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0".

[1502] [Example 4-15]

In Example 4-15, as the electrode substrate for electrolysis at the cathode, a substrate identical to that in Example 4-3 (measured thickness 30 μm and open porosity ratio 44%) was used. The cathode used in Test Example 1, which was worn out and had an increased electrolysis voltage, was placed in place of the nickel grid as a supply conductor. Except as described above, the electrolysis performance was evaluated on a structure identical to that in Example 4-1. That is, in a sectional structure, a cell, a down conductor, a mat, a cathode that was worn out and had an increased electrolysis voltage (serving as a supply conductor), the cathode, membrane and anode were placed in that order from the side of the cathode chamber to form a structure with a zero gap, and the cathode, which is worn out and has an increased electrolysis voltage, served as a supply conductor. Except as described above, the evaluation was performed in the same manner as in Example 4-1 and the results are shown in Table 7.

Sufficient traction was observed.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 0 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less under measurement condition 1 and 0.0027 (kPa · s / m) under measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0".

[1503] [Example 4-16]

As an electrode substrate for electrolysis at the anode, a titanium foil having a measured thickness of 20 µm was used. Both surfaces of the titanium foil were roughened. A porous foil was formed by punching this titanium foil to form circular holes by punching. The hole diameter was 1 mm and the open porosity ratio was 14%. The arithmetic average Ra of the surface roughness was 0.37 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate.

A cover fluid for use in forming an electrode catalyst was prepared according to the following procedure. Solutions of ruthenium chloride having a ruthenium concentration of 100 g / L (Tanaka Kikinzoku Kogyo KK), iridium chloride having an iridium concentration of 100 g / L (Tanaka Kikinzoku Kogyo KK), and titanium tetrachloride (Wako Pure Chemical Industries, Ltd.) mixed so that the molar ratio of ruthenium element, iridium element and titanium element was 0.25: 0.25: 0.5. This mixed solution was thoroughly mixed and used as an anode coating liquid.

[1504] A bath containing the above coating liquid was placed in the lowest position of the roller coater. The vat was positioned such that a coating roll obtained by winding a closed cell type EPDM sponge rubber (INOAC CORPORATION, E-4088, 10 mm thick) around a polyvinyl chloride (PVC) cylinder was always in contact with the casing fluid. A roller for coating, around which the same EPDM was wound, was placed on its upper part, and a PVC roller was additionally placed above it. The coating liquid was applied in such a way that the electrode substrate was passed between the second coating roller and the PVC roller in the uppermost position (roller coating method). After the above coating liquid was applied to the titanium porous foil, drying was carried out at 60 ° C for 10 minutes and firing at 475 ° C for 10 minutes. A series of these operations of coating, drying, pre-calcining, and calcining were performed several times, and then calcination was carried out at 520 ° C. for one hour.

The electrode obtained by the above method was cut into pieces measuring 95 mm in length and 110 mm in width to evaluate the performance of electrolysis. The cut electrode sample was adhered using the surface tension of an aqueous solution at substantially the central position of the sulfonic acid layer side of the ion exchange membrane A (size: 160 mm × 160 mm) obtained in [Method (i)] and equilibrated with aqueous 0, 1 n. NaOH solution.

[1505] The cathode was obtained according to the following procedure. First, a 40 mesh nickel wire mesh having a wire diameter of 150 µm was prepared as a substrate. After blasting with aluminum oxide as a pretreatment, the wire mesh was immersed in 6-normal hydrochloric acid for 5 minutes, thoroughly washed with clean water and dried.

Then, a ruthenium chloride solution having a ruthenium concentration of 100 g / L (from Tanaka Kikinzoku Kogyo KK) and a cerium chloride solution (from KISHIDA CHEMICAL Co., Ltd.) were mixed so that the molar ratio between ruthenium element and cerium element was 1: 0 , 25. This mixed solution was thoroughly mixed and used as a covering liquid for the cathode.

The bath containing the above coating liquid was placed in the lowest position of the roller coater. The vat was positioned such that a coating roll obtained by winding a closed cell type EPDM sponge rubber (INOAC CORPORATION, E-4088, 10 mm thick) around a polyvinyl chloride (PVC) cylinder was always in contact with the casing fluid. A roller for coating, around which the same EPDM was wound, was placed on its upper part, and a PVC roller was additionally placed above it. The coating liquid was applied in such a way that the electrode substrate was passed between the second coating roller and the PVC roller in the uppermost position (roller coating method). Then thereafter, drying was carried out at 50 ° C for 10 minutes, pre-firing at 300 ° C for 3 minutes, and firing at 550 ° C for 10 minutes. Thereafter, firing was carried out at 550 ° C. for an hour. A series of these operations of coating, drying, pre-firing and firing was repeated.

[1506] A nickel expanded metal sheet was used as a current collector of the cathode chamber. The down conductor was 95 mm long × 110 mm wide. As the metal elastic body, a mat formed by knitting a thin nickel wire was used. The mat as a metal elastic body was placed on the down conductor. A cathode obtained by the above method was placed on top of it, and a cord made of Teflon (R) was used to fix the four corners of the grid to the down conductor.

Even when the four corners of the membrane portion of the membrane-combined electrode, which was obtained by combining the membrane with the electrode, were clamped and suspended so that the membrane-integrated electrode was parallel to the base so that the electrode was facing toward the base, the electrode did not detach or move. In addition, when both ends of one side were clamped and suspended so that the membrane-integrated electrode was perpendicular to the base, the electrode did not detach or move.

[1507] The anode used in Test Example 3, which was worn out and had an increased electrolysis voltage, was fixed in the anode cell by welding, and the above membrane-combined electrode was inserted between the anode cell and the cathode cell so that the surface to which the electrode was attached was facing the side of the anode chamber. That is, in the sectional structure, the cell, the current collector, the mat, the cathode, the membrane, the titanium porous foil as the anode, and the anode, which was worn out and had an increased electrolysis voltage, were placed in this order from the side of the cathode chamber to form a structure with a zero gap. The anode, which was worn out and had an increased electrolysis voltage, served as a supply conductor. The anode made of titanium porous foil and the anode, which was worn out and had an increased electrolysis voltage, were only in physical contact with each other and were not bonded to each other by welding.

[1508] The evaluation of this construct was carried out in the same manner as in Example 4-1, and the results are shown in Table 7.

The electrode thickness was 26 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 6 µm.

Sufficient traction was observed.

When a strain test was performed on the electrode, the average of L ₁ and L ₂ was 4 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0060 (kPa · s / m) at measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good, like "1". Membrane damage was also rated as good: "0".

[1509] [Example 4-17]

In Example 4-17, a titanium foil having a measured thickness of 20 μm and an open porosity ratio of 30% was used as an electrode substrate for electrolysis at the anode. The arithmetic average Ra of the surface roughness was 0.37 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except as described above, the assessment was performed in the same manner as in Example 4-16 and the results are shown in Table 7.

The electrode thickness was 30 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 10 µm.

Sufficient traction was observed.

When a strain test was performed on the electrode, the average of L ₁ and L ₂ was 5 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less under measurement condition 1 and 0.0030 (kPa · s / m) under measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0".

[1510] [Example 4-18]

In Example 4-18, a titanium foil having a measured thickness of 20 μm and an open porosity ratio of 42% was used as an electrode substrate for electrolysis at the anode. The arithmetic average Ra of the surface roughness was 0.38 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except as described above, the assessment was performed in the same manner as in Example 4-16 and the results are shown in Table 7.

The electrode thickness was 32 µm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 12 µm.

Sufficient traction was observed.

When a strain test was performed on the electrode, the average of L ₁ and L ₂ was 2.5 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0022 (kPa · s / m) at measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good (no damage): "0".

[1511] [Example 4-19]

In Example 4-19, a titanium foil having a measured thickness of 50 μm and an open porosity ratio of 47% was used as an electrode substrate for electrolysis at the anode. The arithmetic average Ra of the surface roughness was 0.40 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except as described above, the assessment was performed in the same manner as in Example 4-16 and the results are shown in Table 7.

The electrode thickness was 69 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 19 µm.

Sufficient traction was observed.

When a strain test was performed on the electrode, the average of L ₁ and L ₂ was 8 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0024 (kPa · s / m) at measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0".

[1512] [Example 4-20]

In Example 4-20, a titanium nonwoven fabric having a measured thickness of 100 µm, a titanium fiber diameter of about 20 µm, a basis weight of 100 g / m ² and an open porosity ratio of 78% was used as an electrode substrate for electrolysis at the anode. Except as described above, the assessment was performed in the same manner as in Example 4-16 and the results are shown in Table 7.

The electrode thickness was 114 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 14 µm.

Sufficient traction was observed.

When a strain test was performed on the electrode, the average of L ₁ and L ₂ was 2 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0228 (kPa · s / m) at measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0".

[1513] [Example 4-21]

In Example 4-21, a 150 mesh titanium wire mesh having a measured thickness of 120 µm and a titanium fiber diameter of 60 µm was used as an electrode substrate for electrolysis at the anode. The open porosity ratio was 42%. Blasting was carried out using 320 grit alumina. It was difficult to measure the surface roughness of the wire mesh. Then, in Example 4-21, a titanium plate having a thickness of 1 mm was simultaneously blasted during blasting, and the surface roughness of the titanium plate was taken as the surface roughness of the wire mesh. The arithmetic average Ra of the surface roughness was 0.60 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except as described above, the assessment was performed in the same manner as in Example 4-16 and the results are shown in Table 7.

The electrode thickness was 140 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 20 µm.

Sufficient traction was observed.

When a strain test was performed on the electrode, the average of L ₁ and L ₂ was 10 mm. It was found that the electrode had a wide range of elastic deformation.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0132 (kPa · s / m) at measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0".

[1514] [Example 4-22]

[1515] In Example 4-22, an anode that was worn out and had an increased electrolysis voltage was used in the same way as in Example 4-16 as the anode supply conductor, and a titanium nonwoven fabric identical to the material in Example 4-20, used as an anode. A cathode that was worn out and had an increased electrolysis voltage was used in the same way as in Example 4-15 as the cathode supply conductor, and a nickel foil electrode identical to that in Example 4-3 was used as the cathode. In a sectional structure, a cell, a down conductor, a mat, a cathode that was worn out and had an increased electrolysis voltage, a nickel porous foil as a cathode, a membrane, a titanium nonwoven fabric as an anode, and an anode that was worn out and had an increased electrolysis voltage were placed in the specified from the side of the cathode chamber to form a zero-gap structure, and the cathode and anode, which were worn out and had an increased electrolysis voltage, served as a supply conductor. Except as described above, the evaluation was performed in the same way as in Example 4-1, and the results are shown in Table 7.

The thickness of the electrode (anode) was 114 µm, and the thickness of the catalytic layer, which was determined by subtracting the thickness of the electrolysis electrode substrate from the thickness of the electrode (anode), was 14 µm. The thickness of the electrode (cathode) was 38 µm, and the thickness of the catalytic layer, which was determined by subtracting the thickness of the electrolysis electrode substrate from the thickness of the electrode (cathode), was 8 µm.

Sufficient adhesion force was observed at both the anode and cathode.

When the deformation test of the electrode (anode) was carried out, the average of L ₁ and L ₂ was 2 mm. When the deformation test of the electrode (cathode) was carried out, the average of L ₁ and L ₂ was 0 mm.

When the ventilation resistance of the electrode (anode) was measured, the ventilation resistance was 0.07 (kPa s / m) or less under measurement conditions 1 and 0.0228 (kPa s / m) under measurement conditions 2. When the ventilation resistance of the electrode ( cathode), the ventilation resistance was 0.07 (kPa s / m) or less under measurement condition 1 and 0.0027 (kPa s / m) under measurement condition 2.

In addition, the electrode exhibited low electrical voltage, high current efficiency, and low total caustic salt concentration. Manufacturability was also good: "1". Membrane damage was also rated as good: "0" for both the anode and cathode. In Example 4-22, the cathode and anodes were combined by connecting the cathode to one surface of the membrane and the anode to the other surface of the membrane, and evaluated for membrane damage.

[1516] [Example 4-23]

In Example 4-23, a Zirfon Perl UTP 500 microporous membrane from Agfa was used.

The Zirfon membrane was immersed in clean water for 12 hours or more and used for testing. Except for the above, the above evaluation was performed in the same way as in Example 4-3, and the results are shown in Table 7.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 0 mm. It was found that the electrode had a wide range of elastic deformation.

Similar to the situation where an ion exchange membrane was used as the membrane, sufficient adhesion force was observed. The microporous membrane was brought into tight contact with the electrode by surface tension, and the workability was good: "1".

[1517] [Test Case 1]

In Control Example 1, a cathode was used that had been used as a cathode in a large cell for eight years, which was worn out and showed an increased electrolysis voltage. The above cathode was placed instead of a nickel mesh feed conductor on the cathode chamber mat, and an ion exchange membrane A obtained in [Method (i)] was placed between them. The electrolysis performance was then evaluated. In Control Example 1, the membrane-integrated electrode was not used. In the sectional structure, the cell, the current collector, the mat, the cathode, which was worn out and showed an increased electrolysis voltage, the ion-exchange membrane A and the anodes were placed in the indicated order from the side of the cathode chamber to form a structure with a zero gap.

As a result of evaluating the characteristics of electrolysis to this structure, the voltage was 3.04 V, was 97.0% current efficiency, the total concentration of salt in caustic soda (a value converted based on 50%) was 20 million ^-1. Thus, due to electrode wear, the voltage was high.

[1518] [Test Case 2]

In Control Example 2, a nickel mesh feed conductor was used as the cathode. That is, the electrolysis was carried out on a nickel grid that does not have a catalytic coating.

A nickel mesh cathode was placed on the cathode chamber mat and an ion exchange membrane A obtained in [Method (i)] was placed between them. The electrolysis performance was then evaluated. In the sectional structure of the electrical cell of Test Example 2, a down conductor, mat, nickel mesh, ion exchange membrane A, and anodes were placed in this order from the side of the cathode chamber to form a zero-gap structure.

As a result of evaluating the characteristics of electrolysis to this structure, the voltage was 3.38 V, was 97.7% current efficiency, the total concentration of salt in caustic soda (a value converted based on 50%) was 24 million ^-1. Thus, the voltage was high due to the uncoated cathode catalyst.

[1519] [Test Case 3]

In Control Example 3, an anode was used as the anode, which had been used in a large cell for about eight years, was worn out, and showed an increased electrolysis voltage.

In the sectional design of the electrical cell of Test Example 3, a down conductor, mat, cathode, and ion exchange membrane A obtained in [Method (i)], and an anode that was worn out and showed an increased electrolysis voltage were placed in that order from the side of the cathode chamber to form zero clearance designs.

As a result of evaluating the characteristics of electrolysis to this structure, the voltage was 3.18 V, was 97.0% current efficiency, the total concentration of salt in caustic soda (a value converted based on 50%) was 22 million ^-1. Thus, the electrical voltage was high due to the wear of the anode.

[1520] [Example 4-24]

In Example 4-24, a fully rolled nickel expanded metal sheet having a measured thickness of 100 μm and an open porosity ratio of 33% was used as an electrode substrate for cathode electrolysis. Blasting was carried out using alumina with a grit number of 320. The open porosity ratio did not change after blasting. It was difficult to measure the surface roughness of expanded metal sheet. Then, in Example 4-24, a nickel plate having a thickness of 1 mm was simultaneously blasted during blasting and the surface roughness of the nickel plate was taken as the surface roughness of the wire mesh. The arithmetic average Ra of the surface roughness was 0.68 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except as described above, the evaluation was performed in the same manner as in Example 4-1 and the results are shown in Table 7.

The electrode thickness was 114 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 14 µm.

The mass per unit area was 67.5 (mg / cm ² ). The force applied per unit mass · unit area (1) was as small as 0.05 N / (mg · cm ² ). Thus, the result of evaluating the coiling around a string with a diameter of 280 mm (2) was 64%, and the result of evaluating the coiling around a string with a diameter of 145 mm (3) was 22%. The areas where the electrode separated from the membrane were enlarged. This was caused by problems in that the electrode would most likely detach when the combined electrode was used and that the electrode would separate and fall off the diaphragm during loading and unloading. Manufacturability was "4", which was also problematic. Membrane damage was scored "0".

When a strain test was performed on the electrode, the average of L ₁ and L ₂ was 13 mm.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0168 (kPa · s / m) at measurement condition 2.

[1521] [Example 4-25]

In Example 4-25, a fully rolled nickel expanded metal sheet having a measured thickness of 100 μm and an open porosity ratio of 16% was used as an electrode substrate for cathode electrolysis. Blasting was carried out using alumina with a grit number of 320. The open porosity ratio did not change after blasting. It was difficult to measure the surface roughness of expanded metal sheet. Then, in Example 4-25, a nickel plate having a thickness of 1 mm was simultaneously blasted during blasting, and the surface roughness of the nickel plate was taken as the surface roughness of the wire mesh. The arithmetic average Ra of the surface roughness was 0.64 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except as described above, the evaluation was performed in the same manner as in Example 4-1 and the results are shown in Table 7.

The electrode thickness was 107 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 7 µm.

The mass per unit area was 78.1 (mg / cm ² ). The force applied per unit mass · unit area (1) was as small as 0.04 N / (mg · cm ² ). Thus, the result of evaluating the coiling around a string with a diameter of 280 mm (2) was 37%, and the result of evaluating the coiling around a string with a diameter of 145 mm (3) was 25%. The areas where the electrode separated from the membrane were enlarged. This was caused by problems in that the electrode would most likely detach when the combined electrode was used and that the electrode would separate and fall off the diaphragm during loading and unloading. Manufacturability was "4", which was also problematic. Membrane damage was scored "0".

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 18.5 mm.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0176 (kPa · s / m) at measurement condition 2.

[1522] [Example 4-26]

In Example 4-26, a fully rolled nickel expanded metal sheet having a measured thickness of 100 μm and an open porosity ratio of 40% was used as an electrode substrate for cathode electrolysis. Blasting was carried out using alumina with a grit number of 320. The open porosity ratio did not change after blasting. It was difficult to measure the surface roughness of expanded metal sheet. Then, in Example 4-26, a nickel plate having a thickness of 1 mm was simultaneously blasted during blasting and the surface roughness of the nickel plate was taken as the surface roughness of the wire mesh. The arithmetic mean Ra of the surface roughness was 0.70 µm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Coating of the electrolysis electrode substrate was performed by ion deposition in the same manner as in Example 4-6. Except as described above, the evaluation was performed in the same way as in Example 4-1, and the results are shown in Table 7.

The electrode thickness was 110 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 10 µm.

The force applied per unit mass · unit area (1) was as small as 0.07 N / (mg · cm ² ). Thus, the evaluation result of the coiling around a 280 mm diameter string (2) was 80%, and the evaluation result of the coiling around a 145 mm diameter string (3) was 32%. The areas where the electrode separated from the membrane were enlarged. This was caused by problems in that the electrode would most likely detach when the combined electrode was used and that the electrode would separate and fall off the diaphragm during loading and unloading. Manufacturability was "3", which was also problematic. Membrane damage was scored "0".

When a strain test was performed on the electrode, the average of L ₁ and L ₂ was 11 mm.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less under measurement condition 1 and 0.0030 (kPa · s / m) under measurement condition 2.

[1523] [Example 4-27]

In Example 4-27, a fully rolled nickel expanded metal sheet having a measured thickness of 100 μm and an open porosity ratio of 58% was used as an electrode substrate for cathode electrolysis. Blasting was carried out using alumina with a grit number of 320. The open porosity ratio did not change after blasting. It was difficult to measure the surface roughness of expanded metal sheet. Then, in Example 4-27, a nickel plate having a thickness of 1 mm was simultaneously blasted during blasting, and the surface roughness of the nickel plate was taken as the surface roughness of the wire mesh. The arithmetic average Ra of the surface roughness was 0.64 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except as described above, the evaluation was performed in the same way as in Example 4-1, and the results are shown in Table 7.

The electrode thickness was 109 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 9 µm.

The force applied per unit mass · unit area (1) was as small as 0.06 N / (mg · cm ² ). Thus, the result of evaluating the coiling around a string with a diameter of 280 mm (2) was 69%, and the result of evaluating the coiling around a string with a diameter of 145 mm (3) was 39%. The areas where the electrode separated from the membrane were enlarged. This was caused by problems in that the electrode would most likely detach when the combined electrode was used and that the electrode would separate and fall off the diaphragm during loading and unloading. Manufacturability was "3", which was also problematic. Membrane damage was scored "0".

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 11.5 mm.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less under measurement condition 1 and 0.0028 (kPa · s / m) under measurement condition 2.

[1524] [Example 4-28]

In Example 4-28, a nickel wire mesh having a measured thickness of 300 μm and an open porosity ratio of 56% was used as an electrode substrate for cathode electrolysis. It was difficult to measure the surface roughness of the wire mesh. Then, in Example 4-28, a nickel plate having a thickness of 1 mm was simultaneously blasted during blasting, and the surface roughness of the nickel plate was taken as the surface roughness of the wire mesh. Blasting was carried out using alumina with a grit number of 320. The open porosity ratio did not change after blasting. The arithmetic average Ra of the surface roughness was 0.64 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except as described above, the evaluation was performed in the same way as in Example 4-1, and the results are shown in Table 7.

The electrode thickness was 308 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 8 µm.

The mass per unit area was 49.2 (mg / cm ² ). Thus, the evaluation result of the coiling around a 280 mm diameter string (2) was 88%, and the evaluation result of the coiling around a 145 mm diameter string (3) was 42%. The areas where the electrode separated from the membrane were enlarged. This was due to the fact that the electrode was most likely detached when an electrode combined with the membrane was used, and that the electrode separated and fell off the membrane during loading and unloading. A problem arose regarding manufacturability, which was rated as "3". When a large electrode was actually operated, the manufacturability could be rated as "3". Membrane damage was scored "0".

When a strain test was performed on the electrode, the average of L ₁ and L ₂ was 23 mm.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0034 (kPa · s / m) at measurement condition 2.

[1525] [Example 4-29]

In Example 4-29, a nickel wire mesh having a measured thickness of 200 μm and an open porosity ratio of 37% was used as an electrode substrate for cathode electrolysis. Blasting was carried out using alumina with a grit number of 320. The open porosity ratio did not change after blasting. It was difficult to measure the surface roughness of the wire mesh. Then, in Example 4-29, a nickel plate having a thickness of 1 mm was simultaneously blasted during blasting and the surface roughness of the nickel plate was taken as the surface roughness of the wire mesh. The arithmetic average Ra of the surface roughness was 0.65 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except for the above, the evaluation of the electrolysis on the electrode, the results of measuring the adhesion force and adhesion were carried out in the same manner as in Example 4-1. The results are shown in Table 7.

The electrode thickness was 210 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 10 µm.

The weight per unit area was 56.4 mg / cm ² . Thus, the result of evaluating the wrap around the 145 mm diameter string (2) was 63%, and the adhesion between the electrode and the membrane was poor. This was due to the fact that the electrode was most likely detached when an electrode combined with the membrane was used, and that the electrode separated and fell off the membrane during loading and unloading. A problem arose regarding manufacturability, which was rated as "3". Membrane damage was scored "0".

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 19 mm.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less under measurement condition 1 and 0.0096 (kPa · s / m) under measurement condition 2.

[1526] [Example 4-30]

In Example 4-30, a fully rolled titanium expanded metal sheet having a measured thickness of 500 μm and an open porosity ratio of 17% was used as an electrode substrate for electrolysis at the anode. Blasting was carried out using alumina with a grit number of 320. The open porosity ratio did not change after blasting. It was difficult to measure the surface roughness of expanded metal sheet. Then, in Example 4-30, a titanium plate having a thickness of 1 mm was simultaneously blasted during blasting, and the surface roughness of the titanium plate was taken as the surface roughness of the wire mesh. The arithmetic average Ra of the surface roughness was 0.60 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except as described above, the evaluation was performed in the same way as in Example 4-16, and the results are shown in Table 7.

The electrode thickness was 508 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 8 µm.

The weight per unit area was 152.5 (mg / cm ² ). The force applied per unit mass · unit area (1) was as small as 0.01 N / (mg · cm ² ). Thus, the result of evaluating the coiling around a string with a diameter of 280 mm (2) was 5%, and the result of evaluating the coiling around a string with a diameter of 145 mm (3) was 5%. The areas where the electrode separated from the membrane were enlarged. This was due to the fact that the electrode most likely separated when an electrode combined with the membrane was used, and that the electrode separated and fell off the membrane during loading and unloading, and so on. Manufacturability was "4", which was also problematic. Membrane damage was scored "0".

When the electrode was deformed, the electrode did not recover and remained coiled in the shape of a PVC pipe. Thus, it was impossible to measure the values of L ₁ and L _2.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0072 (kPa · s / m) at measurement condition 2.

[1527] [Example 4-31]

In Example 4-31, a fully rolled titanium expanded metal sheet having a measured thickness of 800 μm and an open porosity ratio of 8% was used as an electrode substrate for electrolysis at the anode. Blasting was carried out using alumina with a grit number of 320. The open porosity ratio did not change after blasting. It was difficult to measure the surface roughness of expanded metal sheet. Then, in Example 4-31, a titanium plate having a thickness of 1 mm was simultaneously blasted during blasting, and the surface roughness of the titanium plate was taken as the surface roughness of the wire mesh. The arithmetic average Ra of the surface roughness was 0.61 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except as described above, the evaluation was performed in the same way as in Example 4-16, and the results are shown in Table 7.

The electrode thickness was 808 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 8 µm.

The mass per unit area was 251.3 (mg / cm ² ). The force applied per unit mass · unit area (1) was as small as 0.01 N / (mg · cm ² ). Thus, the result of evaluating the coiling around a string with a diameter of 280 mm (2) was 5%, and the result of evaluating the coiling around a string with a diameter of 145 mm (3) was 5%. The areas where the electrode separated from the membrane were enlarged. This was due to the fact that the electrode most likely separated when an electrode combined with the membrane was used, and that the electrode separated and fell off the membrane during loading and unloading, and so on. Manufacturability was "4", which was also problematic. Membrane damage was scored "0".

When the electrode was deformed, the electrode did not recover and remained coiled in the shape of a PVC pipe. Thus, it was impossible to measure the values of L ₁ and L _2.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0172 (kPa · s / m) at measurement condition 2.

[1528] [Example 4-32]

In Example 4-32, a fully rolled titanium expanded metal sheet having a measured thickness of 1000 μm and an open porosity ratio of 46% was used as an electrode substrate for electrolysis at the anode. Blasting was carried out using alumina with a grit number of 320. The open porosity ratio did not change after blasting. It was difficult to measure the surface roughness of expanded metal sheet. Then, in Example 4-32, a titanium plate having a thickness of 1 mm was simultaneously blasted during blasting, and the surface roughness of the titanium plate was taken as the surface roughness of the wire mesh. The arithmetic average Ra of the surface roughness was 0.59 μm. The surface roughness measurement was performed under the same conditions as the surface roughness measurement of a blasted nickel plate. Except as described above, the evaluation was performed in the same way as in Example 4-16, and the results are shown in Table 7.

The electrode thickness was 1011 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 11 µm.

The mass per unit area was 245.5 (mg / cm ² ). The force applied per unit mass · unit area (1) was as small as 0.01 N / (mg · cm ² ). Thus, the result of evaluating the coiling around a string with a diameter of 280 mm (2) was 5%, and the result of evaluating the coiling around a string with a diameter of 145 mm (3) was 5%. The areas where the electrode separated from the membrane were enlarged. This was due to the fact that the electrode most likely separated when an electrode combined with the membrane was used, and that the electrode separated and fell off the membrane during loading and unloading, and so on. Manufacturability was "4", which was also problematic. Membrane damage was scored "0".

When the electrode was deformed, the electrode did not recover and remained coiled in the shape of a PVC pipe. Thus, it was impossible to measure the values of L ₁ and L _2.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less under measurement condition 1 and 0.0027 (kPa · s / m) under measurement condition 2.

[1529] [Example 4-33]

In Example 4-33, a thermally pressed assembly was obtained by thermocompressing a membrane electrode with reference to a prior art document (Examples in Japanese Patent Laid-Open No. 58-48686).

A nickel expanded metal sheet having a measured thickness of 100 μm and an open porosity ratio of 33% was used as an electrode substrate for cathode electrolysis to perform electrode plating in the same manner as in Example 4-1. Thereafter, one surface of the electrode was subjected to inactivation treatment according to the following procedure. A polyimide adhesive tape (from Chukoh Chemical Industries, Ltd.) was attached to one surface of the electrode. The other surface was coated with a PTFE dispersion (Dupont-Mitsui Fluorochemicals Co., Ltd., 31-JR (trade name)) and dried in a muffle oven at 120 ° C for 10 minutes. The polyimide tape was separated and fired in a muffle furnace adjusted to a temperature of 380 ° C for 10 minutes. This operation was repeated twice to inactivate one surface of the electrode.

[1530] Received a membrane formed of two layers of perfluorocarbon polymer, the end group of which is "-COOCH ₃ " (C-polymer), and a perfluorocarbon polymer, the end group of which is "-SO ₂ F" (S-polymer). The C-resin layer was 3 mils (0.003 in., 0.0762 mm) thick and the S-resin layer was 4 mils (0.004 in., 0.01 mm) thick. This bilayer membrane was subjected to a saponification treatment, thereby introducing ion exchange groups at the ends of the polymer by hydrolysis. The end groups of the C – polymer were hydrolyzed to form carboxyl groups, and the end groups of the S – polymer were hydrolyzed to form sulfo groups. The ion-exchange capacity with sulfonic acid groups was 1.0 mg-eq / g, and the ion-exchange capacity with carboxylic acid groups was 0.9 mg-eq / g.

The electrode with its inactivated surface was placed opposite the surface having carboxyl groups as ion-exchange groups, and thermocompression was performed with it, combining the ion-exchange membrane and the electrode. One surface of the electrode was open even after thermocompression, and the electrode did not spread over part of the membrane.

After that, in order to prevent the bubbles formed during electrolysis from sticking to the membrane, a mixture of zirconium oxide and a perfluorocarbon polymer into which sulfo groups were introduced was applied to both surfaces. Thereby, the membrane and electrode assembly of Example 4-33 was obtained.

[1531] When the force applied per unit mass · unit area (1) was measured using this thermocompression assembly, the electrode did not move upward because the electrode and the membrane were tightly connected by thermocompression. Then, the ion exchange membrane and the nickel plate were fixed so that they were stationary and the electrode was pulled upward with a higher force. When a force of 1.50 N / (mg · cm ² ) was reached, part of the membrane ruptured. The thermocompression knot of Example 4-33 had a force applied per unit mass · unit area (1) of at least 1.50 N / (mg · cm ² ), and they were firmly connected.

[1532] When the evaluation of the winding around the string with a diameter of 280 mm (1), the contact area with the plastic pipe was less than 5%. Meanwhile, when the evaluation of the wrapping around the 280 mm diameter column (2) was carried out, the electrode and the membrane were 100% connected to each other, but the membrane was not wrapped around the column at all. The result of evaluating the coiling around a 145 mm diameter string (3) was the same. The result showed that the integrated electrode impaired the processability of the membrane, making it difficult to wind the membrane into a roll and create folds of the membrane. Manufacturability was "3", which was problematic. Membrane damage was scored "0". In addition, when the electrolysis performance was evaluated, the electric voltage was high, the current efficiency was low, and the total concentration of salt in the caustic soda (the value converted to 50%) was increased and the electrolysis performance was deteriorated.

The electrode thickness was 114 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 14 µm.

When a strain test was performed on the electrode, the average of L ₁ and L ₂ was 13 mm.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0168 (kPa · s / m) at measurement condition 2.

[1533] [Example 4-34]

In Example 4-34, a 40 mesh nickel grid having a wire diameter of 150 µm, a measured thickness of 300 µm and an open porosity ratio of 58% was used as an electrode substrate for cathode electrolysis. Except as described above, a membrane and electrode assembly was prepared in the same manner as in Example 4-33.

When the force applied per unit mass · unit area (1) was measured using this thermocompression assembly, the electrode did not move upward because the electrode and the membrane were tightly connected by thermocompression. Then, the ion exchange membrane and the nickel plate were fixed so that they were stationary and the electrode was pulled upward with a higher force. When a force of 1.60 N / (mg · cm ² ) was reached, part of the membrane ruptured. The membrane and electrode assembly of Example 4.34 had a force applied per unit mass · unit area (1) of at least 1.60 N / (mg · cm ² ), and they were firmly connected.

[1534] When evaluating the wrapping around a 280 mm diameter column (1) using this membrane and electrode assembly, the contact area with the plastic pipe was less than 5%. Meanwhile, when the evaluation of the wrapping around the 280 mm diameter column (2) was carried out, the electrode and the membrane were 100% connected to each other, but the membrane was not wrapped around the column at all. The result of evaluating the coiling around a 145 mm diameter string (3) was the same. The result showed that the integrated electrode impaired the processability of the membrane, making it difficult to wind the membrane into a roll and create folds of the membrane. Manufacturability was "3", which was problematic. In addition, when the electrolysis performance was evaluated, the electric voltage was high, the current efficiency was low, and the total concentration of salt in the caustic soda (the value converted to 50%) was increased and the electrolysis performance was deteriorated.

The electrode thickness was 308 μm. The thickness of the catalytic layer, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 8 µm.

When a strain test was performed on the electrode, the average of L ₁ and L ₂ was 23 mm.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.07 (kPa · s / m) or less at measurement condition 1 and 0.0034 (kPa · s / m) at measurement condition 2.

[1535] [Example 4-35]

Nickel wire having a measured thickness of 150 µm was used as an electrode substrate for electrolysis at the cathode. A roughening treatment was carried out on this nickel wire. It was difficult to measure the surface roughness of the nickel wire. Then, in Example 4.35, a nickel plate having a thickness of 1 mm was simultaneously blasted during blasting, and the surface roughness of the nickel plate was taken as the surface roughness of the nickel wire. Blasting was carried out using alumina with a grain number of 320. The arithmetic average Ra of the surface roughness was 0.64 μm.

A cover fluid for use in forming an electrode catalyst was prepared according to the following procedure. A ruthenium nitrate solution having a ruthenium concentration of 100 g / L (from FURUYA METAL Co., Ltd.) and a cerium nitrate solution (from KISHIDA CHEMICAL Co., Ltd.) were mixed so that the molar ratio between ruthenium and cerium was 1 : 0.25. This mixed solution was thoroughly mixed and used as a covering liquid for the cathode.

The bath containing the above coating liquid was placed in the lowest position of the roller coater. The vat was positioned such that a coating roll obtained by winding a closed cell EPDM sponge rubber (INOAC CORPORATION, E-4088 (trade name), 10 mm thick) around a polyvinyl chloride (PVC) ) of the cylinder, was always in contact with the cover fluid. A roller for coating, around which the same EPDM was wound, was placed on its upper part, and a PVC roller was additionally placed above it. The coating liquid was applied in such a way that the electrode substrate was passed between the second coating roller and the PVC roller in the uppermost position (roller coating method). Then, after drying at 50 ° C for 10 minutes, pre-firing at 150 ° C for 3 minutes and firing at 350 ° C for 10 minutes were carried out. A series of these operations of coating, drying, pre-baking and baking were repeated until a predetermined coating value was reached. The thickness of the resulting electrode was 570 μm. The thickness of the nickel wire obtained in Example 2-34 was 158 µm.

[1536] The nickel wire obtained by the above method was cut into pieces of 110 mm in length and 95 mm in length. As shown in Figure 85, a 110mm nickel wire and a 95mm nickel wire were positioned so that the nickel wires were vertically overlapped at the center of each of the nickel wires and joined together at the intersection with Aron Alpha adhesive to form electrode. The electrode was evaluated and the results are shown in Table 7.

The portion of the electrode in which the nickel wires were overlapped had the largest thickness, and the thickness of the electrode was 306 µm. The thickness of the catalytic layer was 6 μm. The open porosity ratio was 99.7%.

[1537] The mass per unit area of the electrode was 0.5 (mg / cm ² ). The forces applied per unit mass · unit area (1) and (2) were in both cases equal to or less than the lower limit of the tensile test machine. Thus, the result of evaluating the winding around a 280 mm diameter column (2) was less than 5%, and the areas where the electrode separated from the membrane were enlarged. Manufacturability was "4", which was also problematic. Membrane damage was scored "0".

When a strain test was performed on the electrode, the average of L ₁ and L ₂ was 15 mm.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.001 (kPa s / m) or less under the measurement condition 2. When the measurement was carried out under the measurement condition 2 in the SENSE mode (measuring range) of the ventilation resistance measuring device set to H (high) , the ventilation resistance was 0.0002 (kPa · s / m).

In addition, the structure shown in FIG. 86 was used to position an electrode (cathode) on the Ni-grid supply conductor, and the electrolysis performance of the electrode was evaluated by the method described in Evaluation of Electrolysis Performance (9). As a result, the voltage was high at 3.16 V.

[1538] [Example 4-36]

In Example 4-36, the electrode obtained in Example 4-35 was used. As shown in Figure 87, a 110 mm nickel wire and a 95 mm nickel wire were placed so that the nickel wires were vertically overlapped at the center of each of the nickel wires and joined together at the intersection with Aron Alpha adhesive to form electrode. The electrode was evaluated and the results are shown in Table 7.

The portion of the electrode in which the nickel wires were overlapped had the largest thickness, and the thickness of the electrode was 306 µm. The thickness of the catalytic layer was 6 μm. The open porosity ratio was 99.4%.

The mass per unit area of the electrode was 0.9 (mg / cm ² ). The forces applied per unit mass · unit area (1) and (2) were in both cases equal to or less than the lower limit of the tensile test machine. Thus, the result of evaluating the winding around a 280 mm diameter column (2) was less than 5%, and the areas where the electrode separated from the membrane were enlarged. Manufacturability was "4", which was also problematic. Membrane damage was scored "0".

When a strain test was performed on the electrode, the average of L ₁ and L ₂ was 16 mm.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.001 (kPa s / m) or less under the measurement condition 2. When the measurement was carried out under the measurement condition 2 in the SENSE mode (measuring range) of the ventilation resistance measuring device set to H (high) , the ventilation resistance was 0.0004 (kPa · s / m).

In addition, the structure shown in FIG. 88 was used to position an electrode (cathode) on a Ni-grid supply conductor, and the electrolysis performance of the electrode was evaluated by the method described in Evaluation of Electrolysis Performance (9). As a result, the voltage was high at 3.18 V.

[1539] [Example 4-37]

In Example 4-37, the electrode obtained in Comparative Example 2.34 was used. As shown in Figure 89, a 110 mm nickel wire and a 95 mm nickel wire were placed so that the nickel wires were vertically overlapped at the center of each of the nickel wires and joined together at the intersection with Aron Alpha adhesive to form electrode. The electrode was evaluated and the results are shown in Table 7.

The portion of the electrode in which the nickel wires were overlapped had the largest thickness, and the thickness of the electrode was 306 µm. The thickness of the catalytic layer was 6 μm. The open porosity ratio was 98.8%.

The mass per unit area of the electrode was 1.9 (mg / cm ² ). The forces applied per unit mass · unit area (1) and (2) were in both cases equal to or less than the lower limit of the tensile test machine. Thus, the result of evaluating the winding around a 280 mm diameter column (2) was less than 5%, and the areas where the electrode separated from the membrane were enlarged. Manufacturability was "4", which was also problematic. Membrane damage was scored "0".

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 14 mm.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 0.001 (kPa s / m) or less under the measurement condition 2. When the measurement was carried out under the measurement condition 2 in the SENSE mode (measuring range) of the ventilation resistance measuring device set to H (high) , the ventilation resistance was 0.0005 (kPa · s / m).

In addition, the structure shown in FIG. 90 was used to position an electrode (cathode) on the Ni-grid supply conductor, and the electrolysis performance of the electrode was evaluated by the method described in Evaluation of Electrolysis Performance (9). As a result, the voltage was high at 3.18 V.

[1540] [Comparative Example 4-1]

(Getting a catalyst)

An aqueous solution of metal salts was prepared by adding 0.728 g of silver nitrate (from Wako Pure Chemical Industries, Ltd.) and 1.86 g of cerium nitrate hexahydrate (from Wako Pure Chemical Industries, Ltd.) to 150 ml of pure water. An alkali solution was prepared by adding 240 g of pure water to 100 g of a 15% aqueous solution of tetramethylammonium hydroxide (Wako Pure Chemical Industries, Ltd.). While the alkali solution was stirred using a magnetic stirrer, an aqueous solution of metal salts was added dropwise thereto at a rate of 5 ml / minute using a burette. The suspension containing the formed dispersed particles of metal hydroxides was filtered with suction and then washed with water to remove the contained alkali. Then the residue was transferred into 200 ml of 2-propanol (KISHIDA CHEMICAL Co., Ltd.) and redispersed in an ultrasonic disperser (US-600T, NISSEI Corporation) for 10 minutes to obtain a homogeneous suspension.

A carbon black suspension was prepared by dispersing 0.36 g of hydrophobic carbon black (DENKA BLACK (R) AB-7 (trade name), Denka Company Limited) and 0.84 g of hydrophobic carbon black (Ketjenblack (R) EC-600JD (trade name), from Mitsubishi Chemical Corporation) in 100 ml of 2-propanol, and the mixture was dispersed in an ultrasonic disperser for 10 minutes. The metal hydroxide precursor slurry and the carbon black slurry were mixed and dispersed in an ultrasonic disperser for 10 minutes. This suspension was filtered with suction and dried at room temperature for half a day to obtain a soot containing a dispersed and fixed precursor of metal hydroxides. Then, an inert gas kiln (type VMF165, manufactured by YAMADA DENKI CO., LTD.) Was used to conduct firing under nitrogen at 400 ° C. for an hour to obtain carbon black A containing a dispersed and fixed electrode catalyst.

[1541] (Getting the powder for the reaction layer)

To 1.6 g of carbon black A containing the dispersed and fixed electrode catalyst, 0.84 ml of the surfactant Triton (R) X-100 (trade name, ICN Biomedicals) diluted to 20% by weight with pure water was added, and 15 ml of pure water, and the mixture was dispersed in an ultrasonic disperser for 10 minutes. To this dispersion was added 0.664 g of a polytetrafluoroethylene (PTFE) dispersion (PTFE30J (trade name), Dupont-Mitsui Fluorochemicals Co., Ltd.). After stirring the mixture for five minutes, suction filtration was performed. In addition, the residue was dried in a dryer at 80 ° C for one hour, and pulverized using a mill to obtain a powder for the reaction layer A.

(Obtaining a powder for a gas diffusion layer)

Dispersed 20 g of hydrophobic carbon black (DENKA BLACK (R) AB-7 (trade name)), 50 ml of the surfactant Triton (R) X-100 (trade name), diluted to 20% by weight with pure water, and 360 ml clean water in an ultrasonic disperser for 10 minutes. To the resulting dispersion was added 22.32 g of PTFE dispersion. The mixture was stirred for 5 minutes and then filtered. In addition, the residue was dried in a dryer at 80 ° C. for an hour, and pulverized using a mill to obtain powder for gas diffusion layer A.

(Obtaining a gas diffusion electrode)

To 4 g of powder for gas diffusion layer A was added 8.7 ml of ethanol and the mixture was kneaded to form a paste. This powder for the gas diffusion layer A in a paste form was formed into a sheet-like shape using a roll forming apparatus. A silver mesh (SW = 1, LW = 2, and thickness = 0.3 mm) was embedded in the sheet as a current collector, and finally molded to form a sheet having a thickness of 1.8 mm. To 1 g of powder for reaction layer A was added 2.2 ml of ethanol, and the mixture was compounded to form a paste. This reaction layer powder in pasty form was roll formed into a sheet-like shape having a thickness of 0.2 mm. In addition, two sheets, that is, a sheet obtained using the powder for the gas diffusion layer A and a sheet obtained using the powder for the reaction layer A, were laminated and formed into a sheet having a thickness of 1.8 mm using a roll former. This layered sheet was dried at room temperature overnight to remove ethanol. In addition, to remove the residual surfactant, the sheet was subjected to pyrolysis in air at 300 ° C for an hour. The sheet was wrapped with aluminum foil and hot pressed in a hot pressing machine (SA303 (trade name) from TESTER SANGYO CO,. LTD.) At 360 ° C and 50 kgf / cm ² for 1 minute to obtain a gas diffusion electrode. The thickness of the gas diffusion electrode was 412 μm.

[1542] The resulting electrode was used to perform electrolysis performance evaluation. In a sectional structure, an electrolytic cell, a down conductor, a mat, a nickel grid as a supply conductor, an electrode, a membrane, and an anode were placed in this order from the side of the cathode chamber to form a structure with a zero gap. The results are shown in Table 7.

When the deformation test was performed on the electrode, the average of L ₁ and L ₂ was 19 mm.

When the ventilation resistance of the electrode was measured, the ventilation resistance was 25.88 (kPa · s / m) under measurement condition 1.

Manufacturability was "3", which is problematic. In addition, when the electrolysis performance was evaluated, the current efficiency was low, the total salt concentration in the caustic soda was increased, and the electrolysis performance was markedly deteriorated. Membrane damage, which was rated 3, was also problematic.

[1543] These results showed that the gas diffusion electrode obtained in Comparative Example 4-1 had markedly deteriorated electrolysis performance. In addition, damage was observed over substantially the entire surface of the ion exchange membrane. This was hypothesized to be due to the action of NaOH, which was formed in the electrode, accumulating at the interface between the electrode and the membrane with an increase in its concentration, due to the markedly higher ventilation resistance of the gas diffusion electrode in Comparative Example 4-1.

[1544]

[Table 6]

Electrode support Electrode support shape Coating method Supply conductor Example 4-1 Ni Perforation Pyrolysis Ni-mesh Example 4-2 Ni Perforation Pyrolysis Ni-mesh Example 4-3 Ni Perforation Pyrolysis Ni-mesh Example 4-4 Ni Perforation Pyrolysis Ni-mesh Example 4-5 Ni Perforation Pyrolysis Ni-mesh Example 4-6 Ni Perforation Ionic deposition Ni-mesh Example 4-7 Ni Electroforming Pyrolysis Ni-mesh Example 4-8 Ni Electroforming Pyrolysis Ni-mesh Example 4-9 Ni Non-woven fabric Pyrolysis Ni-mesh Example 4-10 Ni Non-woven fabric Pyrolysis Ni-mesh Example 4-11 Ni Porous Ni Pyrolysis Ni-mesh Example 4-12 Ni Grid Pyrolysis Ni-mesh Example 4-13 Ni Grid Pyrolysis Ni-mesh Example 4-14 Ni Perforation (same as Example 4-3) Pyrolysis Mat Example 4-15 Ni Perforation (same as Example 4-3) Pyrolysis Overvoltage cathode Example 4-16 Ti Perforation Pyrolysis Overvoltage anode Example 4-17 Ti Perforation Pyrolysis Overvoltage anode Example 4-18 Ti Perforation Pyrolysis Overvoltage anode Example 4-19 Ti Perforation Pyrolysis Overvoltage anode Example 4-20 Ti Non-woven fabric Pyrolysis Overvoltage anode Example 4-21 Ti Grid Pyrolysis Overvoltage anode Example 4-22 Ni / Ti Combination of Example 4-3 and Example 4-20 Pyrolysis Overvoltage cathode and anode Example 4-23 Ni Perforation Pyrolysis - Example 4-24 Ni Expanded metal Pyrolysis Ni-mesh Example 4-25 Ni Expanded metal Pyrolysis Ni-mesh Example 4-26 Ni Expanded metal Ionic deposition Ni-mesh Example 4-27 Ni Expanded metal Pyrolysis Ni-mesh Example 4-28 Ni Grid Pyrolysis Ni-mesh Example 4-29 Ni Grid Pyrolysis Ni-mesh Example 4-30 Ti Expanded metal Pyrolysis Overvoltage anode Example 4-31 Ti Expanded metal Pyrolysis Overvoltage anode Example 4-32 Ti Expanded metal Pyrolysis Overvoltage anode Example 4-33 Ni Expanded metal Pyrolysis Ni-mesh Example 4-34 Ni Grid Pyrolysis Ni-mesh Example 4-35 Ni Grid Pyrolysis Ni-mesh Example 4-36 Ni Grid Pyrolysis Ni-mesh Example 4-37 Ni Grid Pyrolysis Ni-mesh Comparative Example 4-1 Carbon Powder Pyrolysis Ni-mesh

[1545]

[1546] In Table 7, all specimens were able to self-support due to surface tension before measuring “force applied per unit mass · unit area (1)” and “force applied per unit mass · unit area (2)” (that is, not slide down).

[1547] <Checking the fifth embodiment>

As will be described below, Experimental Examples according to the fifth embodiment are presented (in the section <Verification of the fifth embodiment>, below, simply referred to as “Examples”) and Experimental Examples not corresponding to the fifth embodiment (in the section <Verification of the fifth embodiment>, hereinafter simply referred to as "Comparative Examples"), and evaluated by the following method. Details will be described with reference to Figures 93-94 and 100-102 as appropriate.

[1548] The following ion-exchange membrane A was used as a membrane.

Monofilaments with a size of 90 denier made of polytetrafluoroethylene (PTFE) (hereinafter referred to as PTFE yarns) were used as reinforcing materials of the core. The consumable yarns were yarns obtained by twisting 200 times / meter of six 35 denier polyethylene terephthalate (PET) filaments (hereinafter referred to as PET yarns). First, in each of the TD- and MD-directions, plain weaving of PTFE-yarns and consumable yarns with 24 PTFE-yarns / inch was performed so that two consumable yarns were placed between adjacent PTFE-yarns to obtain a woven fabric. The resulting woven fabric was subjected to roller compaction to obtain a woven fabric having a thickness of 70 µm.

Then resin A was obtained in the form of a dry resin, which was a copolymer of CF ₂ = CF ₂ and CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ COOCH ₃ and had an ion exchange capacity of 0.85 mg-eq / g, and the resin B in the form of a dry resin, which was a copolymer of CF ₂ = CF ₂ and CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₂ F and had an ion exchange capacity of 1.03 mg⋅eq / g.

Using these resins A and B, a two-layer film X in which the thickness of the resin layer A was 15 µm and the thickness of the resin layer B was 104 µm was obtained by a flat die coextrusion method.

Then release paper (having embossing with a conical shape with a height of 50 μm), reinforcing material and film X were laminated in this order on a hot plate having a heat source and a vacuum source inside and having micropores on its surface, heated and depressurized under surface temperature conditions hot plate 223 ° C and a reduced pressure value of 0.067 MPa for 2 minutes, and then remove the release paper to obtain a composite membrane.

The resulting composite membrane was immersed in an aqueous solution heated to 80 ° C. containing 30% by weight of dimethyl sulfoxide (DMSO) and 15% by weight of potassium hydroxide (KOH) for 20 minutes for saponification. Then the composite membrane was immersed in an aqueous 0.5N hydrochloric acid heated to 50 ° C. sodium hydroxide solution (NaOH) for one hour to replace the counterion of the ion exchange group with Na, and then washed with water. Then the membrane was dried at 60 ° C.

In addition, 20% by mass of zirconium oxide having a primary particle size of 1 μm was added to an ethanol solution with a concentration of 5% by mass of resin B as an acidic resin and dispersed to obtain a slurry, and the slurry was sprayed onto both surfaces of the above composite membrane. the method of spraying a suspension with the formation of coatings of zirconium oxide on the surfaces of the composite membrane to obtain an ion-exchange membrane A. The density of the coating of zirconium oxide, measured by X-ray fluorescence analysis, was 0.5 mg / cm ² . The average particle size was measured with a particle size analyzer (manufactured by SHIMADZU CORPORATION, "SALD (R) 2200").

[1549] The cathode and anode described below were used as an electrode.

As an electrode substrate for a cathode in electrolysis, an electrolytic nickel foil having a measured thickness of 22 µm was obtained. One surface of this nickel foil was roughened by electrolytic nickel plating. The arithmetic mean Ra of the roughness of the rough surface was 0.95 μm. The surface roughness measurement was performed under the same conditions as in the case of the surface roughness measurement of the blasted nickel plate.

A porous foil was formed by punching this nickel foil into circular holes by punching. The open porosity ratio was 44%.

A cover fluid for use in forming an electrode catalyst was prepared according to the following procedure. Solutions of ruthenium nitrate having a ruthenium concentration of 100 g / L (from FURUYA METAL Co., Ltd.) and cerium nitrate (from KISHIDA CHEMICAL Co., Ltd.) were mixed so that the molar ratio between ruthenium and cerium was 1: 0.25. This mixed solution was thoroughly mixed and used as a covering liquid for the cathode.

The bath containing the above coating liquid was placed in the lowest position of the roller coater. The vat was positioned such that a coating roll obtained by winding a closed cell type EPDM sponge rubber (INOAC CORPORATION, E-4088, 10 mm thick) around a polyvinyl chloride (PVC) cylinder was always in contact with the casing fluid. A roller for coating, around which the same EPDM was wound, was placed on its upper part, and a PVC roller was additionally placed above it. The coating liquid was applied in such a way that the electrode substrate was passed between the second coating roller and the PVC roller in the uppermost position (roller coating method). Then, after drying at 50 ° C for 10 minutes, pre-firing at 150 ° C for 3 minutes and firing at 350 ° C for 10 minutes were carried out. A series of these operations of coating, drying, pre-baking and baking were repeated until a predetermined coating value was reached. The thickness of the resulting electrode was 29 μm. The thickness of the catalytic layer containing ruthenium oxide and cerium oxide, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 7 µm. A coating was also formed on a surface that was not roughened.

[1550] As an electrode substrate for electrolysis at the anode, a titanium nonwoven fabric having a measured thickness of 100 μm, a titanium fiber diameter of about 20 μm, a basis weight of 100 g / m ² and an open porosity ratio of 78% was used.

A cover fluid for use in forming an electrode catalyst was prepared according to the following procedure. Solutions of ruthenium chloride having a ruthenium concentration of 100 g / L (Tanaka Kikinzoku Kogyo KK), iridium chloride having an iridium concentration of 100 g / L (Tanaka Kikinzoku Kogyo KK), and titanium tetrachloride (Wako Pure Chemical Industries, Ltd.) mixed so that the molar ratio of ruthenium element, iridium element and titanium element was 0.25: 0.25: 0.5. This mixed solution was thoroughly mixed and used as an anode coating liquid.

The bath containing the above coating liquid was placed in the lowest position of the roller coater. The vat was positioned such that a coating roll obtained by winding a closed cell type EPDM sponge rubber (INOAC CORPORATION, E-4088, 10 mm thick) around a polyvinyl chloride (PVC) cylinder was always in contact with the casing fluid. A roller for coating, around which the same EPDM was wound, was placed on its upper part, and a PVC roller was additionally placed above it. The coating liquid was applied in such a way that the electrode substrate was passed between the second coating roller and the PVC roller in the uppermost position (roller coating method). After the above coating liquid was applied to the titanium porous foil, drying was carried out at 60 ° C for 10 minutes and firing at 475 ° C for 10 minutes. A series of these operations of coating, drying, pre-calcining, and calcining were performed several times, and then calcination was carried out at 520 ° C. for one hour.

[1551] [Example 5-1]

(Example of application of a laminated product from a cathode and a membrane)

Received the winding in advance as follows. First, an ion exchange membrane having a size of 1.5 m in length and 2.5 m in width was obtained according to the above method. In addition, according to the above method, four cathodes having a size of 0.3 m in length and 2.4 m in width were obtained.

After the ion exchange membrane was immersed in 2% sodium bicarbonate solution for a full day and night, the cathodes were placed without any gap on the side of the carboxylic acid layer of the ion exchange membrane to form a layered article of cathodes and ion exchange membrane (see Figure 100) ... When the cathodes were placed on the membrane, in contact with an aqueous sodium bicarbonate solution, surface tension was applied and the cathodes and membrane were combined as if they were glued together. No pressure was applied for this unification. The combining temperature was 23 ° C. The resulting laminate was wound around a polyvinyl chloride (PVC) pipe having an outer diameter of 76 mm and a length of 1.7 m as shown in Figure 101 to form a winding. The winding was in a cylindrical shape having an outer diameter of 84 mm and a length of 1.7 m, and this allowed the size of the laminated product to be reduced.

Then, in an existing large cell (cell having a construction similar to that shown in Figures 93 and 94), the adjacent electrolytic cells and the ion exchange membrane were released from the secured state using the pressing device, and the existing membrane was removed to form a gap between the electrolytic cells. After that, the winding was transferred to a large electrolyzer. On a large electrolytic cell, while the PVC pipe was installed vertically, unwinding was started from the coiled state in order to draw out the coiled laminated product. At this time, the laminated article was supported substantially vertically with respect to the base, but the cathode did not detach. Then, after the laminated product was inserted between the electrolytic cells, the electrolytic cells were shifted to interpose the laminated product between them.

The electrode and membrane could be replaced in a simpler way than under standard conditions. It was concluded that the renewal of the electrode and the replacement of the membrane can be performed in a few tens of minutes per cell, when the laminated article in the form of a winding is prepared in advance during the operation of the electrolyzer.

[1552] [Example 5-2]

(Example of application of a laminated product from anode and membrane)

Received the winding in advance as follows. First, an ion exchange membrane having a size of 1.5 m in length and 2.5 m in width was obtained according to the above method. In addition, according to the above method, four anodes were prepared having a size of 0.3 m in length and 2.4 m in width.

After the ion exchange membrane was immersed in a 2% sodium bicarbonate solution for a whole day and night, the anodes were placed without any gap on the side of the sulfonic acid layer of the ion exchange membrane in the same manner as in Example 5-1 to form a layered products from anodes and ion-exchange membrane. When the anodes were placed on the membrane in contact with an aqueous sodium bicarbonate solution, surface tension was created and the anodes and membrane were combined as if they were glued together. No pressure was applied for this unification. The combining temperature was 23 ° C. The resulting laminated article was wound around a polyvinyl chloride (PVC) pipe having an outer diameter of 76 mm and a length of 1.7 m to form a winding in the same manner as in Example 5-1. The winding was in a cylindrical shape having an outer diameter of 86 mm and a length of 1.7 m, and this allowed the size of the laminated product to be reduced.

Then, in an existing large cell (cell similar to the cell in Example 5-1), the adjacent cell cells and the ion exchange membrane were released from the fixed state using a clamping device, and the existing membrane was removed to form a gap between the cells. After that, the winding was transferred to a large electrolyzer. On a large electrolytic cell, while the PVC pipe was installed vertically, unwinding was started from the coiled state in order to draw out the coiled laminated product. At this time, the laminate was supported substantially vertical with respect to the base, but the anode was not detached. Then, after the laminated product was inserted between the electrolytic cells, the electrolytic cells were shifted to interpose the laminated product between them.

The electrode and membrane could be replaced in a simpler way than under standard conditions. It was concluded that the renewal of the electrode and the replacement of the membrane can be performed in a few tens of minutes per cell, when the laminated article in the form of a winding is prepared in advance during the operation of the electrolyzer.

[1553] [Example 5-3]

(Application example of anode / cathode laminated product and membrane)

Received the winding in advance as follows. First, an ion exchange membrane having a size of 1.5 m in length and 2.5 m in width was obtained according to the above method. In addition, according to the above method, four anodes and four cathodes having a size of 0.3 m in length and 2.4 m in width were obtained.

After the ion exchange membrane was immersed in a 2% sodium bicarbonate solution for a whole day and night, the cathodes were placed on the side of the carboxylic acid layer, and the anodes were placed on the side of the sulfonic acid layer without any gap in the same way as in Example 5–1, with the formation of a layered product from cathodes, anodes and an ion-exchange membrane. When the cathodes and anodes were placed on the membrane in contact with an aqueous sodium bicarbonate solution, surface tension was created and the cathodes and anodes and membrane were combined as if they were glued together. No pressure was applied for this unification. The combining temperature was 23 ° C. The resulting laminated article was wound around a polyvinyl chloride (PVC) pipe having an outer diameter of 76 mm and a length of 1.7 m to form a winding in the same manner as in Example 5-1. The winding was in a cylindrical shape having an outer diameter of 88 mm and a length of 1.7 m, and this allowed the size of the laminated product to be reduced.

Then, in an existing large cell (cell similar to the cell in Example 5-1), the adjacent cell cells and the ion exchange membrane were released from the fixed state using a clamping device, and the existing membrane was removed to form a gap between the cells. After that, the winding was transferred to a large electrolyzer. On a large electrolytic cell, while the PVC pipe was installed vertically, unwinding was started from the coiled state in order to draw out the coiled laminated product. At this time, the laminate was supported substantially vertical with respect to the base, but the anode was not detached. Then, after the laminated product was inserted between the electrolytic cells, the electrolytic cells were shifted to interpose the laminated product between them.

The electrode and membrane could be replaced in a simpler way than under standard conditions. It was concluded that the renewal of the electrode and the replacement of the membrane can be performed in a few tens of minutes per cell, when the laminated article in the form of a winding is prepared in advance during the operation of the electrolyzer.

[1554] [Example 5-4]

(Example of application of cathodes)

Received the winding in advance as follows. First, according to the above method, four cathodes were prepared having a size of 0.3 m in length and 2.4 m in width. The four cathodes, without any gap, were positioned to achieve a size of 1.2 m in length and 2.4 m in width. Adjacent cathodes were connected to each other and secured so that the cathodes were not separated by stitching with PTFE yarn through holes in each cathode (not shown) as shown in Figure 102. No pressure was applied during this operation and the temperature was 23 ° C. These cathodes were wound around a polyvinyl chloride (PVC) pipe having an outer diameter of 76 mm and a length of 1.7 m to form a winding in the same manner as in Example 5-1. The winding was in a cylindrical shape having an outer diameter of 78 mm and a length of 1.7 m, and this allowed the size of the laminated product to be reduced.

Then, in an existing large cell (cell similar to the cell in Example 5-1), the adjacent cell cells and the ion exchange membrane were released from the fixed state using a clamping device, and the existing membrane was removed to form a gap between the cells. After that, the winding was transferred to a large electrolyzer. On a large electrolytic cell, while the PVC pipe was set vertically, unwinding was started from the coiled state in order to pull out the coiled cathodes. At this time, the cathodes were maintained substantially vertical to the base, but the cathodes were not detached. Then, after the cathodes were inserted between the electrolytic cells, the electrolytic cells were shifted to interpose the laminated article between them.

The cathodes could be replaced in a simpler way than under standard conditions. It was concluded that the renewal of the cathodes can be performed in a few tens of minutes per cell, when the cathode winding is obtained in advance during the operation of the electrolyzer.

[1555] [Example 5-5]

(Anode application example)

Received the winding in advance as follows. First, according to the above method, four anodes were prepared having a size of 0.3 m in length and 2.4 m in width. The four anodes, without any gap, were positioned to achieve a size of 1.2 m in length and 2.4 m in width. Adjacent anodes were connected to each other with PTFE yarn and secured so that the anodes did not separate, in the same way as in Example 5-1. In this operation, no pressure was applied and the temperature was 23 ° C. These anodes were wound around a polyvinyl chloride (PVC) pipe having an outer diameter of 76 mm and a length of 1.7 m to form a winding in the same manner as in Example 5-1. The winding was in a cylindrical shape having an outer diameter of 81 mm and a length of 1.7 m, and this allowed the size of the laminated product to be reduced.

Then, in an existing large cell (cell similar to the cell in Example 5-1), the adjacent cell cells and the ion exchange membrane were released from the fixed state using a clamping device, and the existing membrane was removed to form a gap between the cells. After that, the winding was transferred to a large electrolyzer. In a large cell, while the PVC pipe was set vertically, unwinding was started from the coiled state to pull out the coiled anodes. At this time, the cathodes were kept substantially vertical to the base, but the anodes were not detached. Then, after the anodes were inserted between the electrolytic cells, the electrolytic cells were shifted to interpose the laminate between them.

The anodes could be replaced in a simpler way than under standard conditions. It was concluded that the renewal of the anodes can be performed in a few tens of minutes per cell, when the winding from the anodes is obtained in advance during the operation of the electrolyzer.

[1556] [Comparative Example 5-1]

(Standard electrode renewal)

In an existing large cell (cell similar to the cell in Example 5-1), adjacent cell cells and the ion exchange membrane were released from the fixed state using a clamping device and the existing membrane was removed to form a gap between the cells. Thereafter, the electrolytic cells were lifted out of the large electrolytic cell using a hoist. The removed electrolytic cells were transported to a facility where conditions for welding were available.

After the anode fixed by welding on the edge of the electrolytic cell was cut off, a grinder and the like removed burrs or the like from the portion from which the anode was cut to smooth the portion. The cathode was removed by removing the section, secured by folding the section into a down conductor.

Thereafter, a new anode was placed on the edge of the anode chamber, and the new anode was spot-welded in the electrolytic cell. Similarly in the case of the cathode, a new cathode was placed on the cathode side and secured by folding the cathode into a down conductor.

The refurbished electrolytic cell was transferred to a large cell location and the cell was returned to the cell using a hoist.

The period of time required for the release of the electrolytic cell and the ion exchange membrane from the fixed state before re-fastening the electrolytic cell was one day or more.

[1557] <Checking the sixth embodiment>

As will be described below, Experimental Examples according to the sixth embodiment are presented (in the section <Verification of the sixth embodiment>, below, simply referred to as “Examples”) and Experimental Examples not corresponding to the sixth embodiment (in the section <Verification of the sixth embodiment>, hereinafter simply referred to as "Comparative Examples"), and evaluated by the following method. Details will be described with reference to Figures 105 and 106 as appropriate.

[1558] The ion exchange membrane b described below was used as the membrane.

Monofilaments with a size of 90 denier made of polytetrafluoroethylene (PTFE) (hereinafter referred to as PTFE yarns) were used as reinforcing materials of the core. The consumable yarns were yarns obtained by twisting 200 times / meter of six 35 denier polyethylene terephthalate (PET) filaments (hereinafter referred to as PET yarns). First, in each of the TD- and MD-directions, plain weaving of PTFE-yarns and consumable yarns with 24 PTFE-yarns / inch was performed so that two consumable yarns were placed between adjacent PTFE-yarns to obtain a woven fabric. The resulting woven fabric was subjected to roller compaction to obtain a woven fabric having a thickness of 70 µm.

Then resin A was obtained in the form of a dry resin, which was a copolymer of CF ₂ = CF ₂ and CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ COOCH ₃ and had an ion exchange capacity of 0.85 mg-eq / g, and the resin B in the form of a dry resin, which was a copolymer of CF ₂ = CF ₂ and CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₂ F and had an ion exchange capacity of 1.03 mg⋅eq / g.

Using these resins A and B, a two-layer film X in which the thickness of the resin layer A was 15 µm and the thickness of the resin layer B was 104 µm was obtained by a flat die coextrusion method.

Then release paper (having embossing with a conical shape with a height of 50 μm), reinforcing material and film X were laminated in this order on a hot plate having a heat source and a vacuum source inside and having micropores on its surface, heated and depressurized under surface temperature conditions hot plate 223 ° C and a reduced pressure value of 0.067 MPa for 2 minutes, and then remove the release paper to obtain a composite membrane.

The resulting composite membrane was immersed in an aqueous solution heated to 80 ° C. containing 30% by weight of dimethyl sulfoxide (DMSO) and 15% by weight of potassium hydroxide (KOH) for 20 minutes for saponification. Then the composite membrane was immersed in an aqueous 0.5N hydrochloric acid heated to 50 ° C. sodium hydroxide solution (NaOH) for one hour to replace the counterion of the ion exchange group with Na, and then washed with water. Then the membrane was dried at 60 ° C.

In addition, 20% by mass of zirconium oxide having a primary particle size of 1 μm was added to an ethanol solution with a concentration of 5% by mass of resin B as an acidic resin and dispersed to obtain a slurry, and the slurry was sprayed onto both surfaces of the above composite membrane. the method of spraying a suspension with the formation of coatings of zirconium oxide on the surfaces of the composite membrane to obtain an ion-exchange membrane A. The density of the coating of zirconium oxide, measured by X-ray fluorescence analysis, was 0.5 mg / cm ² . The average particle size was measured with a particle size analyzer (manufactured by SHIMADZU CORPORATION, "SALD (R) 2200").

[1559] The cathode and anode described below were used as an electrode.

As an electrode substrate for a cathode in electrolysis, an electrolytic nickel foil having a measured thickness of 22 µm was obtained. One surface of this nickel foil was roughened by electrolytic nickel plating. The arithmetic mean Ra of the roughness of the rough surface was 0.95 μm. The surface roughness measurement was performed under the same conditions as in the case of the surface roughness measurement of the blasted nickel plate.

A porous foil was formed by punching this nickel foil into circular holes by punching. The open porosity ratio was 44%.

A cover fluid for use in forming an electrode catalyst was prepared according to the following procedure. Solutions of ruthenium nitrate having a ruthenium concentration of 100 g / L (from FURUYA METAL Co., Ltd.) and cerium nitrate (from KISHIDA CHEMICAL Co., Ltd.) were mixed so that the molar ratio between ruthenium and cerium was 1: 0.25. This mixed solution was thoroughly mixed and used as a covering liquid for the cathode.

The bath containing the above coating liquid was placed in the lowest position of the roller coater. The vat was positioned such that a coating roll obtained by winding a closed cell type EPDM sponge rubber (INOAC CORPORATION, E-4088, 10 mm thick) around a polyvinyl chloride (PVC) cylinder was always in contact with the casing fluid. A roller for coating, around which the same EPDM was wound, was placed on its upper part, and a PVC roller was additionally placed above it. The coating liquid was applied in such a way that the electrode substrate was passed between the second coating roller and the PVC roller in the uppermost position (roller coating method). Then, after drying at 50 ° C for 10 minutes, pre-firing at 150 ° C for 3 minutes and firing at 350 ° C for 10 minutes were carried out. A series of these operations of coating, drying, pre-baking and baking were repeated until a predetermined coating value was reached. The thickness of the resulting electrode was 29 μm. The thickness of the catalytic layer containing ruthenium oxide and cerium oxide, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 7 µm. A coating was also formed on a surface that was not roughened.

[1560] A titanium nonwoven fabric having a measured thickness of 100 µm, a titanium fiber diameter of about 20 µm, a basis weight of 100 g / m ² and an open porosity ratio of 78% was used as an electrode substrate for electrolysis at the anode.

A cover fluid for use in forming an electrode catalyst was prepared according to the following procedure. Solutions of ruthenium chloride having a ruthenium concentration of 100 g / L (Tanaka Kikinzoku Kogyo KK), iridium chloride having an iridium concentration of 100 g / L (Tanaka Kikinzoku Kogyo KK), and titanium tetrachloride (Wako Pure Chemical Industries, Ltd.) mixed so that the molar ratio of ruthenium element, iridium element and titanium element was 0.25: 0.25: 0.5. This mixed solution was thoroughly mixed and used as an anode coating liquid.

The bath containing the above coating liquid was placed in the lowest position of the roller coater. The vat was positioned such that a coating roll obtained by winding a closed cell type EPDM sponge rubber (INOAC CORPORATION, E-4088, 10 mm thick) around a polyvinyl chloride (PVC) cylinder was always in contact with the casing fluid. A roller for coating, around which the same EPDM was wound, was placed on its upper part, and a PVC roller was additionally placed above it. The coating liquid was applied in such a way that the electrode substrate was passed between the second coating roller and the PVC roller in the uppermost position (roller coating method). After the above coating liquid was applied to the titanium porous foil, drying was carried out at 60 ° C for 10 minutes and firing at 475 ° C for 10 minutes. A series of these operations of coating, drying, pre-calcining, and calcining were performed several times, and then calcination was carried out at 520 ° C. for one hour.

[1561] [Example 6-1]

(Example of application of a laminated product from a cathode and a membrane)

Received the winding in advance as follows. First, an ion exchange membrane b having a size of 1.5 m in length and 2.5 m in width was prepared according to the above method. In addition, according to the above method, four cathodes having a size of 0.3 m in length and 2.4 m in width were obtained.

After the ion exchange membrane b was immersed in 2% sodium bicarbonate solution for a whole day and night, the cathodes were placed without any gap on the side of the carboxylic acid layer of the ion exchange membrane to form a layered article of cathodes and ion exchange membrane b. When the cathodes were placed on the membrane, surface tension was exerted in contact with the aqueous sodium bicarbonate solution, and the cathodes and membrane were combined as if they were glued together. No pressure was applied for this unification. The combining temperature was 23 ° C. The resulting laminated article was wound around a polyvinyl chloride (PVC) pipe having an outer diameter of 76 mm and a length of 1.7 m to form a winding. A temperature of 200 ° C or more is required to melt the ion exchange membrane b. In this example, the ion exchange membrane was not melted during combining.

Then, in an existing large cell (cell having a structure similar to that shown in Figures 105 and 106), the adjacent electrolytic cells and the ion exchange membrane were released from the fixed state using the pressing device, and the existing membrane was removed to form a gap between the electrolytic cells. After that, the winding was transferred to a large electrolyzer. On a large electrolytic cell, while the PVC pipe was installed vertically, unwinding was started from the coiled state in order to draw out the coiled laminated product. At this time, the laminated article was supported substantially vertically with respect to the base, but the cathodes were not detached. Then, after the laminated product was inserted between the electrolytic cells, the electrolytic cells were shifted to interpose the laminated product between them.

The electrode and membrane could be replaced in a simpler way than under standard conditions. It was concluded that the renewal of the electrode and the replacement of the membrane can be performed in a few tens of minutes per cell.

[1562] [Example 6-2]

(Example of application of a laminated product from anode and membrane)

Received the winding in advance as follows. First, an ion exchange membrane b having a size of 1.5 m in length and 2.5 m in width was prepared according to the above method. In addition, according to the above method, four anodes were prepared having a size of 0.3 m in length and 2.4 m in width.

After ion exchange membrane b was immersed in 2% sodium bicarbonate solution for a full day and night, the anodes were placed without any gap on the sulfonic acid side of the ion exchange membrane to form a layered article of anodes and an ion exchange membrane. When the anodes were placed on the membrane, surface tension was exerted in contact with the aqueous sodium bicarbonate solution, and the anodes and membrane were combined as if they were glued together. No pressure was applied for this unification. The combining temperature was 23 ° C. This laminate was wound around a polyvinyl chloride (PVC) pipe having an outer diameter of 76 mm and a length of 1.7 m to form a winding.

Then, in an existing large cell (cell similar to the cell in Example 6-1), adjacent cell cells and the ion exchange membrane were released from the fixed state using a clamping device, and the existing membrane was removed to form a gap between the cells. After that, the winding was transferred to a large electrolyzer. On a large electrolytic cell, while the PVC pipe was installed vertically, unwinding was started from the coiled state in order to draw out the coiled laminated product. At this time, the laminate was supported substantially vertical with respect to the base, but the anode was not detached. Then, after the laminated product was inserted between the electrolytic cells, the electrolytic cells were shifted to interpose the laminated product between them.

The electrode and membrane could be replaced in a simpler way than under standard conditions. It was concluded that the renewal of the electrode and the replacement of the membrane can be performed in a few tens of minutes per cell.

[1563] [Example 6-3]

(Application example of anode / cathode laminated product and membrane)

Received the winding in advance as follows. First, an ion exchange membrane b having a size of 1.5 m in length and 2.5 m in width was prepared according to the above method. In addition, according to the above method, four anodes and four cathodes having a size of 0.3 m in length and 2.4 m in width were obtained.

After the ion exchange membrane b was immersed in a 2% sodium bicarbonate solution for a whole day and night, the cathodes were placed on the side of the carboxylic acid layer of the ion exchange membrane, and the anodes were placed on the side of the sulfonic acid layer of the ion exchange membrane, without any gap. the formation of a layered product from cathodes, anodes and an ion exchange membrane b. When the cathodes and anodes were placed on the membrane, surface tension was exerted in contact with the aqueous sodium bicarbonate solution, and the cathodes and anodes and the membrane were combined as if they were glued together. No pressure was applied for this unification. The combining temperature was 23 ° C. This laminate was wound around a polyvinyl chloride (PVC) pipe having an outer diameter of 76 mm and a length of 1.7 m to form a winding.

Then, in an existing large cell (cell similar to the cell in Example 6-1), adjacent cell cells and the ion exchange membrane were released from the fixed state using a clamping device, and the existing membrane was removed to form a gap between the cells. After that, the winding was transferred to a large electrolyzer. On a large electrolytic cell, while the PVC pipe was installed vertically, unwinding was started from the coiled state in order to draw out the coiled laminated product. At this time, the laminate was supported substantially vertical with respect to the base, but the anode was not detached. Then, after the laminated product was inserted between the electrolytic cells, the electrolytic cells were shifted to interpose the laminated product between them.

The electrode and membrane could be replaced in a simpler way than under standard conditions. It was concluded that the renewal of the electrode and the replacement of the membrane can be performed in a few tens of minutes per cell.

[1564] [Comparative Example 6-1]

A membrane-electrode laminate was obtained by thermocompression of the electrode on the membrane, with reference to Examples in Japanese Patent Laid-Open No. 58-48686.

A nickel expanded metal sheet having a measured thickness of 100 µm and an open porosity ratio of 33% was used as an electrode substrate for cathode electrolysis to perform electrode plating in the same manner as in Example 6-1. The electrode had a size of 200 mm × 200 mm, and the number of electrodes was 72. Thereafter, one surface of each electrode was subjected to inactivation treatment according to the following procedure. A polyimide adhesive tape (from Chukoh Chemical Industries, Ltd.) was attached to one surface of the electrode. The other surface was coated with a PTFE dispersion (Dupont-Mitsui Fluorochemicals Co., Ltd., 31-JR (trade name)) and dried in a muffle oven at 120 ° C for 10 minutes. The polyimide tape was separated and fired in a muffle furnace adjusted to a temperature of 380 ° C for 10 minutes. This operation was repeated twice to inactivate one surface of the electrode.

Received a membrane formed of two layers of perfluorocarbon polymer, the end group of which is "-COOCH ₃ " (C-polymer), and perfluorocarbon polymer, the end group of which is "-SO ₂ F" (S-polymer). The C-resin layer was 3 mils (0.003 in., 0.0762 mm) thick and the S-resin layer was 4 mils (0.004 in., 0.01 mm) thick. This bilayer membrane was subjected to a saponification treatment, thereby introducing ion exchange groups at the ends of the polymer by hydrolysis. The end groups of the C – polymer were hydrolyzed to form carboxyl groups, and the end groups of the S – polymer were hydrolyzed to form sulfo groups. The ion-exchange capacity with sulfonic acid groups was 1.0 mg-eq / g, and the ion-exchange capacity with carboxylic acid groups was 0.9 mg-eq / g. The size of the resulting ion exchange membrane was similar to that of Example 6-1.

The above electrode with its inactivated surface was placed opposite the surface having carboxyl groups as ion-exchange groups, and thermally pressed (by thermocompression) with it, combining the ion-exchange membrane and electrodes. That is, at the temperature at which the ion exchange membrane is melted, 72 electrodes with an area of 200 m ^{2 were} combined with one ion exchange membrane having a size of 1500 mm in length and 2500 mm in width. One surface of each electrode was exposed even after thermocompression, and the electrodes did not extend over a portion of the membrane.

For the large size 1500 mm × 2500 mm, it took a period of one day or more for the process of combining the ion exchange membrane and electrodes by thermocompression. That is, it was concluded that Comparative Example 6-1 required a longer period of time for electrode renewal and membrane replacement than in Examples.

[1565] <Checking the seventh embodiment>

As will be described below, Experimental Examples according to the seventh embodiment are presented (in the section <Verification of the seventh embodiment>, below, simply referred to as “Examples”) and Experimental Examples not corresponding to the seventh embodiment (in the section <Verification of the seventh embodiment>, hereinafter simply referred to as "Comparative Examples"), and evaluated by the following method. Details will be described with reference to Figures 114 and 115 as appropriate.

[1566] The ion exchange membrane described below was used as the membrane.

Monofilaments with a size of 90 denier made of polytetrafluoroethylene (PTFE) (hereinafter referred to as PTFE yarns) were used as reinforcing materials of the core. The consumable yarns were yarns obtained by twisting 200 times / meter of six 35 denier polyethylene terephthalate (PET) filaments (hereinafter referred to as PET yarns). First, in each of the TD- and MD-directions, plain weaving of PTFE-yarns and consumable yarns with 24 PTFE-yarns / inch was performed so that two consumable yarns were placed between adjacent PTFE-yarns to obtain a woven fabric. The resulting woven fabric was subjected to roller compaction to obtain a woven fabric having a thickness of 70 µm.

Then resin A was obtained in the form of a dry resin, which was a copolymer of CF ₂ = CF ₂ and CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ COOCH ₃ and had an ion exchange capacity of 0.85 mg-eq / g, and the resin B in the form of a dry resin, which was a copolymer of CF ₂ = CF ₂ and CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₂ F and had an ion exchange capacity of 1.03 mg⋅eq / g.

Using these resins A and B, a two-layer film X in which the thickness of the resin layer A was 15 µm and the thickness of the resin layer B was 104 µm was obtained by a flat die coextrusion method.

Then release paper (having embossing with a conical shape with a height of 50 μm), reinforcing material and film X were laminated in this order on a hot plate having a heat source and a vacuum source inside and having micropores on its surface, heated and depressurized under surface temperature conditions hot plate 223 ° C and a reduced pressure value of 0.067 MPa for 2 minutes, and then remove the release paper to obtain a composite membrane.

The resulting composite membrane was immersed in an aqueous solution heated to 80 ° C. containing 30% by weight of dimethyl sulfoxide (DMSO) and 15% by weight of potassium hydroxide (KOH) for 20 minutes for saponification. Then the composite membrane was immersed in an aqueous 0.5N hydrochloric acid heated to 50 ° C. sodium hydroxide solution (NaOH) for one hour to replace the counterion of the ion exchange group with Na, and then washed with water. Then the membrane was dried at 60 ° C.

In addition, 20% by mass of zirconium oxide having a primary particle size of 1 μm was added to an ethanol solution with a concentration of 5% by mass of resin B as an acidic resin and dispersed to obtain a slurry, and the slurry was sprayed onto both surfaces of the above composite membrane. the method of spraying a suspension with the formation of coatings of zirconium oxide on the surfaces of the composite membrane to obtain an ion-exchange membrane A. The density of the coating of zirconium oxide, measured by X-ray fluorescence analysis, was 0.5 mg / cm ² . The average particle size was measured with a particle size analyzer (manufactured by SHIMADZU CORPORATION, "SALD (R) 2200").

[1567] The cathode and anode described below were used as an electrode.

As an electrode substrate for a cathode in electrolysis, an electrolytic nickel foil having a measured thickness of 22 µm was obtained. One surface of this nickel foil was roughened by electrolytic nickel plating. The arithmetic mean Ra of the roughness of the rough surface was 0.95 μm. The surface roughness measurement was performed under the same conditions as in the case of the surface roughness measurement of the blasted nickel plate.

A porous foil was formed by punching this nickel foil into circular holes by punching. The open porosity ratio was 44%.

A cover fluid for use in forming an electrode catalyst was prepared according to the following procedure. Solutions of ruthenium nitrate having a ruthenium concentration of 100 g / L (from FURUYA METAL Co., Ltd.) and cerium nitrate (from KISHIDA CHEMICAL Co., Ltd.) were mixed so that the molar ratio between ruthenium and cerium was 1: 0.25. This mixed solution was thoroughly mixed and used as a covering liquid for the cathode.

The bath containing the above coating liquid was placed in the lowest position of the roller coater. The vat was positioned such that a coating roll obtained by winding a closed cell type EPDM sponge rubber (INOAC CORPORATION, E-4088, 10 mm thick) around a polyvinyl chloride (PVC) cylinder was always in contact with the casing fluid. A roller for coating, around which the same EPDM was wound, was placed on its upper part, and a PVC roller was additionally placed above it. The coating liquid was applied in such a way that the electrode substrate was passed between the second coating roller and the PVC roller in the uppermost position (roller coating method). Then, after drying at 50 ° C for 10 minutes, pre-firing at 150 ° C for 3 minutes and firing at 350 ° C for 10 minutes were carried out. A series of these operations of coating, drying, pre-baking and baking were repeated until a predetermined coating value was reached. The thickness of the resulting electrode was 29 μm. The thickness of the catalytic layer containing ruthenium oxide and cerium oxide, which was determined by subtracting the thickness of the electrode substrate for electrolysis from the thickness of the electrode, was 7 µm. A coating was also formed on a surface that was not roughened.

[1568] As an electrode substrate for electrolysis at the anode, a titanium nonwoven fabric having a measured thickness of 100 μm, a titanium fiber diameter of about 20 μm, a basis weight of 100 g / m ² and an open porosity ratio of 78% was used.

A cover fluid for use in forming an electrode catalyst was prepared according to the following procedure. Solutions of ruthenium chloride having a ruthenium concentration of 100 g / L (Tanaka Kikinzoku Kogyo KK), iridium chloride having an iridium concentration of 100 g / L (Tanaka Kikinzoku Kogyo KK), and titanium tetrachloride (Wako Pure Chemical Industries, Ltd.) mixed so that the molar ratio of ruthenium element, iridium element and titanium element was 0.25: 0.25: 0.5. This mixed solution was thoroughly mixed and used as an anode coating liquid.

The bath containing the above coating liquid was placed in the lowest position of the roller coater. The vat was positioned such that a coating roll obtained by winding a closed cell type EPDM sponge rubber (INOAC CORPORATION, E-4088, 10 mm thick) around a polyvinyl chloride (PVC) cylinder was always in contact with the casing fluid. A roller for coating, around which the same EPDM was wound, was placed on its upper part, and a PVC roller was additionally placed above it. The coating liquid was applied in such a way that the electrode substrate was passed between the second coating roller and the PVC roller in the uppermost position (roller coating method). After the above coating liquid was applied to the titanium porous foil, drying was carried out at 60 ° C for 10 minutes and firing at 475 ° C for 10 minutes. A series of these operations of coating, drying, pre-calcining, and calcining were performed several times, and then calcination was carried out at 520 ° C. for one hour.

[1569] [Example 7-1]

(Example of application of a laminated product from a cathode and a membrane)

Received the winding in advance as follows. First, an ion exchange membrane having a size of 1.5 m in length and 2.5 m in width was obtained according to the above method. In addition, according to the above method, four cathodes having a size of 0.3 m in length and 2.4 m in width were obtained.

After the ion exchange membrane was immersed in a 2% sodium bicarbonate solution for a whole day and night, the cathodes were placed without any gap on the side of the carboxylic acid layer of the ion exchange membrane to form a layered article of cathodes and an ion exchange membrane. When the cathodes were placed on the membrane in contact with an aqueous sodium bicarbonate solution, surface tension was created and the cathodes and membrane were combined as if they were glued together. No pressure was applied for this unification. The combining temperature was 23 ° C. This laminate was wound around a polyvinyl chloride (PVC) pipe having an outer diameter of 76 mm and a length of 1.7 m to form a winding.

Then, in an existing large cell (cell having a construction similar to that shown in Figures 114 and 115), the adjacent electrolytic cells and the ion exchange membrane were released from the secured state using the pressing device, and the existing membrane was removed to form a gap between the electrolytic cells. After that, the winding was transferred to a large electrolyzer. On a large electrolytic cell, while the PVC pipe was installed vertically, unwinding was started from the coiled state in order to draw out the coiled laminated product. At this time, the laminated article was supported substantially vertically with respect to the base, but the cathode did not detach. Then, after the laminated product was inserted between the electrolytic cells, the electrolytic cells were shifted to interpose the laminated product between them.

The electrode and membrane could be replaced in a simpler way than under standard conditions. It was concluded that the renewal of the electrode and the replacement of the membrane can be performed in a few tens of minutes per cell, when the winding of the laminated article is preformed during the operation of the electrolyzer.

[1570] [Example 7-2]

(Example of application of a laminated product from anode and membrane)

Received the winding in advance as follows. First, an ion exchange membrane having a size of 1.5 m in length and 2.5 m in width was obtained according to the above method. In addition, according to the above method, four anodes were prepared having a size of 0.3 m in length and 2.4 m in width.

After the ion exchange membrane was immersed in 2% sodium bicarbonate solution for a full day and night, the anodes were placed without any gap on the sulfonic acid side of the ion exchange membrane to form a layered article of anodes and an ion exchange membrane. When the anodes were placed on the membrane in contact with an aqueous sodium bicarbonate solution, surface tension was created and the anodes and membrane were combined as if they were glued together. No pressure was applied for this unification. The combining temperature was 23 ° C. This laminate was wound around a polyvinyl chloride (PVC) pipe having an outer diameter of 76 mm and a length of 1.7 m to form a winding.

Then, in an existing large cell (cell similar to the cell in Example 7-1), adjacent cell cells and the ion exchange membrane were released from the fixed state using a clamping device, and the existing membrane was removed to form a gap between the cells. After that, the winding was transferred to a large electrolyzer. On a large electrolytic cell, while the PVC pipe was installed vertically, unwinding was started from the coiled state in order to draw out the coiled laminated product. At this time, the laminate was supported substantially vertical with respect to the base, but the anode was not detached. Then, after the laminated product was inserted between the electrolytic cells, the electrolytic cells were shifted to interpose the laminated product between them.

The electrode and membrane could be replaced in a simpler way than under standard conditions. It was concluded that the renewal of the electrode and the replacement of the membrane can be performed in a few tens of minutes per cell, when the winding of the laminated article is preformed during the operation of the electrolyzer.

[1571] [Example 7-3]

(Application example of anode / cathode laminated product and membrane)

Received the winding in advance as follows. First, an ion exchange membrane having a size of 1.5 m in length and 2.5 m in width was obtained according to the above method. In addition, according to the above method, four anodes and four cathodes having a size of 0.3 m in length and 2.4 m in width were obtained.

After the ion exchange membrane was immersed in 2% sodium bicarbonate solution for a whole day and night, the cathodes were placed on the side of the carboxylic acid layer of the ion exchange membrane, and the anodes were placed on the side of the sulfonic acid layer of the ion exchange membrane, without any gap to form a layered product made of cathodes, anodes and an ion-exchange membrane. When the cathodes and anodes were placed on the membrane in contact with an aqueous sodium bicarbonate solution, surface tension was created and the cathodes and anodes and membrane were combined as if they were glued together. No pressure was applied for this unification. The combining temperature was 23 ° C. This laminate was wound around a polyvinyl chloride (PVC) pipe having an outer diameter of 76 mm and a length of 1.7 m to form a winding.

Then, in an existing large cell (cell similar to the cell in Example 7-1), adjacent cell cells and the ion exchange membrane were released from the fixed state using a clamping device, and the existing membrane was removed to form a gap between the cells. After that, the winding was transferred to a large electrolyzer. On a large electrolytic cell, while the PVC pipe was installed vertically, unwinding was started from the coiled state in order to draw out the coiled laminated product. At this time, the laminate was supported substantially vertical with respect to the base, but the anode was not detached. Then, after the laminated product was inserted between the electrolytic cells, the electrolytic cells were shifted to interpose the laminated product between them.

The electrode and membrane could be replaced in a simpler way than under standard conditions. It was concluded that the renewal of the electrode and the replacement of the membrane can be performed in a few tens of minutes per cell, when the winding of the laminated article is preformed during the operation of the electrolyzer.

[1572] [Example 7-4]

(Example of application of cathodes)

Received the winding in advance as follows. First, according to the above method, four cathodes were prepared having a size of 0.3 m in length and 2.4 m in width. The four cathodes, without any gap, were positioned to achieve a size of 1.2 m in length and 2.4 m in width. Adjacent cathodes were connected to each other with PTFE yarn and fixed so that the cathodes did not separate. In this operation, no pressure was applied and the temperature was 23 ° C. These cathodes were wound around a polyvinyl chloride (PVC) pipe having an outer diameter of 76 mm and a length of 1.7 m to form a winding.

Then, in an existing large cell (cell similar to the cell in Example 7-1), the adjacent cell cells and the ion exchange membrane were released from the fixed state using a clamping device, and the existing membrane was removed to form a gap between the cells. After that, the winding was transferred to a large electrolyzer. On a large electrolytic cell, while the PVC pipe was set vertically, unwinding was started from the coiled state in order to pull out the coiled cathodes. At this time, the cathodes were maintained substantially vertical to the base, but the cathodes were not detached. Then, after the cathodes were inserted between the electrolytic cells, the electrolytic cells were shifted to interpose the laminated article between them.

The cathodes could be replaced in a simpler way than under standard conditions. It was concluded that the renewal of the cathodes can be performed in a few tens of minutes per cell, when the cathode winding is obtained in advance during the operation of the electrolyzer.

[1573] [Example 7-5]

(Anode application example)

Received the winding in advance as follows. First, according to the above method, four anodes were prepared having a size of 0.3 m in length and 2.4 m in width. The four anodes, without any gap, were positioned to achieve a size of 1.2 m in length and 2.4 m in width. Adjacent anodes were connected to each other with a PTFE thread and fixed in such a way that the anodes were not separated. In this operation, no pressure was applied and the temperature was 23 ° C. These anodes were wound around a polyvinyl chloride (PVC) pipe having an outer diameter of 76 mm and a length of 1.7 m to form a winding.

Then, in an existing large cell (cell similar to the cell in Example 7-1), the adjacent cell cells and the ion exchange membrane were released from the fixed state using a clamping device, and the existing membrane was removed to form a gap between the cells. After that, the winding was transferred to a large electrolyzer. In a large cell, while the PVC pipe was set vertically, unwinding was started from the coiled state to pull out the coiled anodes. At this time, the cathodes were maintained substantially vertical to the base, but the anodes were not detached. Then, after the anodes were inserted between the electrolytic cells, the electrolytic cells were shifted to interpose the laminate between them.

The anodes could be replaced in a simpler way than under standard conditions. It was concluded that the renewal of the anodes can be performed in a few tens of minutes per cell, when the winding from the anodes is obtained in advance during the operation of the electrolyzer.

[1574] [Comparative Example 7-1]

(Standard electrode renewal)

In an existing large cell (cell similar to the cell in Example 7-1), adjacent cell cells and the ion exchange membrane were released from the fixed state using a clamping device, and the existing membrane was removed to form a gap between the cells. Thereafter, the electrolytic cells were lifted out of the large electrolytic cell using a hoist. The removed electrolytic cells were transported to a facility where conditions for welding were available.

After the anode fixed by welding on the edge of the electrolytic cell was cut off, a grinder and the like removed burrs or the like from the portion from which the anode was cut to smooth the portion. The cathode was removed by removing the section, secured by folding the section into a down conductor.

Thereafter, a new anode was placed on the edge of the anode chamber, and the new anode was spot-welded in the electrolytic cell. Similarly in the case of the cathode, a new cathode was placed on the cathode side and secured by folding the cathode into a down conductor.

The refurbished electrolytic cell was transferred to a large cell location and the cell was returned to the cell using a hoist.

The period of time required for the release of the electrolytic cell and the ion exchange membrane from the fixed state before re-fastening the electrolytic cell was one day or more.

[1575] This application is based on Japanese patent applications filed on March 22, 2017 (Japanese Patent Applications Nos. 2017-056524 and 2017-056525) and Japanese patent applications filed on March 20, 2018 (Japanese Patent Applications Nos. 2018-053217, No. 2018–053146, No. 2018–053144, No. 2018–053231, No. 2018–053145, No. 2018–053149, and No. 2018–053139), the contents of which are incorporated herein by reference.

List of reference designations

[1576]

<Figures for First Embodiment>

List of reference symbols for Figure 1

10 electrode support for electrolysis

20 first layer

30 second layer

100 electrode for electrolysis

List of reference symbols for Figures 2-4

1 ion exchange membrane

2 layer of carboxylic acid

3 layer of sulfonic acid

4 core reinforcement material

10 membrane body

11a, 11b coating layer

21, 22 core reinforcement material

100 electrolyzer

200 anode

300 cathode

52 reinforcing yarn

504a consumable yarn

504 through hole

List of reference symbols for Figures 5-9

1 electrolytic cell

2 ion exchange membrane

4 electrolyser

5 holding device

6 cathode terminal

7 anode terminal

10 anode chamber

11 anode

12 anode seal

13 cathode seal

18 reverse current absorber

18a substrate

18b reverse current absorbing layer

19 the bottom of the anode chamber

20 cathode chamber

21 cathode

22 metal elastic body

23 down conductor

24 holder

30 dividing wall

40 cathode construction for electrolysis

List of reference symbols for Figure 10

1 clamping device (SUS)

2 electrode

3 membrane

4 nickel plate (blasted with alumina 320 grit)

100 front surface

200 lateral surface

List of reference symbols for Figures 11-13

1 membrane

2a polyethylene pipe having an outer diameter of 280 mm

2b polyethylene pipe having an outer diameter of 145 mm

3 section of exfoliation

4 area of tight contact

5 electrode

List of Reference Designations for Figure 14

1 polyvinyl chloride (PVC) pipe

2 ion exchange membrane

3 electrode

4 surface plate

List of Reference Designations for Figure 15

1 surface plate

2 deformed electrode

10 clip for fixing the electrode

20 direction in which force is applied

List of reference symbols for Figures 16-21

1 nickel wire 110 mm long

2 nickel wire 950 mm long

3 frame.

[1577]

<Figures for Second Embodiment>

List of Reference Designations for Figure 22

10 electrode support for electrolysis

20 first layer

30 second layer

100 electrode for electrolysis.

[1578]

List of reference symbols for Figures 23-25

1 ion exchange membrane

2 layer of carboxylic acid

3 layer of sulfonic acid

4 core reinforcement material

10 membrane body

11a, 11b coating layer

21, 22 core reinforcement material

100 electrolyzer

200 anode

300 cathode

52 reinforcing yarn

504a consumable yarn

504 through hole.

[1579]

List of reference symbols for Figures 26-30

1 electrolytic cell

2 ion exchange membrane

4 electrolyser

5 holding device

6 cathode terminal

7 anode terminal

10 anode chamber

11 anode

12 anode seal

13 cathode seal

18 reverse current absorber

18a substrate

18b reverse current absorbing layer

19 the bottom of the anode chamber

20 cathode chamber

21 cathode

22 metal elastic body

23 down conductor

24 holder

30 dividing wall

40 cathode construction for electrolysis.

[1580]

List of Reference Designations for Figure 31

1 clamping device (SUS)

2 electrode

3 membrane

4 nickel plate (blasted with 320 grit alumina)

100 front surface

200 lateral surface.

[1581]

List of reference symbols for Figures 32-34

1 membrane

2a polyethylene pipe having an outer diameter of 280 mm

2b polyethylene pipe having an outer diameter of 145 mm

3 section of exfoliation

4 area of tight contact

5 electrode.

[1582]

List of Reference Designations for Figure 35

1 polyvinyl chloride (PVC) pipe

2 ion exchange membrane

3 electrode

4 surface plate.

[1583]

List of Reference Designations for Figure 36

1 surface plate

2 deformed electrode

10 clip for fixing the electrode

20 the direction in which the force is applied.

[1584]

List of Reference Designations for Figures 37-42

1 nickel wire 110 mm long

2 nickel wire 950 mm long

3 frame.

[1585]

<Figures for Third Embodiment>

List of Reference Designations for Figure 43

10 electrode support for electrolysis

20 first layer

30 second layer

100 electrode for electrolysis.

[1586]

List of reference symbols for Figures 44-46

1 ion exchange membrane

2 layer of carboxylic acid

3 layer of sulfonic acid

4 core reinforcement material

10 membrane body

11a, 11b coating layer

21, 22 core reinforcement material

100 electrolyzer

200 anode

300 cathode

52 reinforcing yarn

504a consumable yarn

504 through hole 504.

[1587]

List of Reference Designations for Figures 47-51

1 layered product

2 electrode for electrolysis

2a inner surface of the electrolysis electrode

2b outer surface of the electrolysis electrode

3 membrane

3a inner surface of the membrane

3b outer surface of the membrane

7 fastening element.

[1588]

List of Reference Designations for Figures 52-56

1 electrolytic cell

2 ion exchange membrane

4 electrolyser

5 holding device

6 cathode terminal

7 anode terminal

10 anode chamber

11 anode

12 anode seal

13 cathode seal

18 reverse current absorber

18a substrate

18b reverse current absorbing layer

19 the bottom of the anode chamber

20 cathode chamber

21 cathode

22 metal elastic body

23 down conductor

24 holder

30 dividing wall

40 cathode construction for electrolysis.

[1589]

<Figures for Fourth Embodiment>

List of reference designations for Figures 63-67

1 electrolytic cell

2 ion exchange membrane

4 electrolyser

5 holding device

6 cathode terminal

7 anode terminal

10 anode chamber

11 anode

12 anode seal

13 cathode seal

18 reverse current absorber

18a substrate

18b reverse current absorbing layer

19 the bottom of the anode chamber

20 cathode chamber

21 cathode

22 metal elastic body

23 down conductor

24 holder

30 dividing wall

40 cathode construction for electrolysis.

[1590]

List of Reference Designations for Figure 68

10 electrode support for electrolysis

20 first layer

30 second layer

100 electrode for electrolysis.

[1591]

List of reference designations for Figures 69-71

1 ion exchange membrane

2 layer of carboxylic acid

3 layer of sulfonic acid

4 core reinforcement material

10 membrane body

11a, 11b coating layer

21, 22 core reinforcement material

100 electrolyzer

200 anode

300 cathode

52 reinforcing yarn

504a consumable yarn

504 through hole.

[1592]

List of Reference Designations for Figures 72 to 78

1 layered product

2 electrode for electrolysis

2a inner surface of the electrolysis electrode

2b outer surface of the electrolysis electrode

3 membrane

3a inner surface of the membrane

3b outer surface of the membrane

7 fastener

A seal

B membrane

C electrode for electrolysis

A1 outermost perimeter of the seal

B1 outermost perimeter of the membrane

C1 is the outermost perimeter of the electrolysis electrode.

[1593]

List of Reference Designations for Figure 79

1 clamping device (SUS)

2 electrode

3 membrane

4 nickel plate (blasted with 320 grit alumina)

100 front surface

200 lateral surface.

[1594]

List of Reference Designations for Figures 80–82

1 membrane

2a polyethylene pipe having an outer diameter of 280 mm

2b polyethylene pipe having an outer diameter of 145 mm

3 section of exfoliation

4 area of tight contact

5 electrode.

[1595]

List of Reference Designations for Figure 84

1 surface plate

2 deformed electrode

10 clip for fixing the electrode

20 the direction in which the force is applied.

[1596]

List of reference designations for Figures 85–90

1 nickel wire 110 mm long

2 nickel wire 950 mm long

3 frame.

[1597]

<Figures for Fifth Embodiment>

List of reference designations for Figures 91–95

1 electrolytic cell

2 ion exchange membrane

4 electrolyser

5 holding device

6 cathode terminal

7 anode terminal

10 anode chamber

11 anode

12 anode seal

13 cathode seal

18 reverse current absorber

18a substrate

18b reverse current absorbing layer

19 the bottom of the anode chamber

20 cathode chamber

21 cathode

22 metal elastic body

23 down conductor

24 holder

30 dividing wall

40 cathode construction for electrolysis.

[1598]

List of Reference Designations for Figure 96

10 electrode support for electrolysis

20 first layer

30 second layer

100 electrode for electrolysis.

[1599]

List of reference designations for Figures 97–99

1 ion exchange membrane

2 layer of carboxylic acid

3 layer of sulfonic acid

4 core reinforcement material

10 membrane body

11a, 11b coating layer

21, 22 core reinforcement material

100 electrolyzer

200 anode

300 cathode

52 reinforcing yarn

504a consumable yarn

504 through hole.

[1600]

<Figures for Sixth Embodiment>

List of reference designations for Figures 103-107

1 electrolytic cell

2 ion exchange membrane

4 electrolyser

5 holding device

6 cathode terminal

7 anode terminal

10 anode chamber

11 anode

12 anode seal

13 cathode seal

18 reverse current absorber

18a substrate

18b reverse current absorbing layer

19 the bottom of the anode chamber

20 cathode chamber

21 cathode

22 metal elastic body

23 down conductor

24 holder

30 dividing wall

40 cathode construction for electrolysis.

[1601]

List of Reference Designations for Figure 108

10 electrode support for electrolysis

20 first layer

30 second layer

100 electrode for electrolysis.

[1602]

List of reference symbols for Figures 109-111

1 ion exchange membrane

2 layer of carboxylic acid

3 layer of sulfonic acid

4 core reinforcement material

10 membrane body

11a, 11b coating layer

21, 22 core reinforcement material

100 electrolyzer

200 anode

300 cathode

52 reinforcing yarn

504a consumable yarn

504 through hole.

[1603]

<Figures for Seventh Embodiment>

List of reference symbols for Figures 112-118

1 electrolytic cell

2 ion exchange membrane

2a new ion exchange membrane

4 electrolyser

5 holding device

6 cathode terminal

7 anode terminal

8 electrolyzer frame

9 layered product

10 anode chamber

11 anode

12 anode seal

13 cathode seal

18 reverse current absorber

18a substrate

18b reverse current absorbing layer

19 the bottom of the anode chamber

20 cathode chamber

21 cathode

22 metal elastic body

23 down conductor

24 holder

30 dividing wall

40 cathode construction for electrolysis

100 electrode for electrolysis.

[1604]

List of Reference Designations for Figure 119

10 electrode support for electrolysis

20 first layer

30 second layer

100 electrode for electrolysis.

[1605]

List of Reference Designations for Figures 120-122

1 ion exchange membrane

2 layer of carboxylic acid

3 layer of sulfonic acid

4 core reinforcement material

10 membrane body

11a, 11b coating layer

21, 22 core reinforcement material

100 electrolyzer

200 anode

300 cathode

52 reinforcing yarn

504a consumable yarn

504 through hole.

Claims (38)

1. A layered product for electrolysis, containing: electrolysis electrode, the membrane or supply conductor in contact with the electrolysis electrode, and a liquid enclosed between the electrolysis electrode and the membrane or supply conductor, the liquid allowing the electrolysis electrode and the membrane or supply conductor to adhere to each other by adhesion and has a surface tension of 20 mN / m to 80 mN / m. 2. A laminated article for electrolysis according to claim 1, in which the liquid is selected from the following liquids having surface tension as indicated: hexane (20.44 mN / m), acetone (23.30 mN / m), methanol (24, 00 mN / m), ethanol (24.05 mN / m), ethylene glycol (50.21 mN / m) and water (72.76 mN / m). 3. The layered electrolysis article of claim 1 or 2, wherein the liquid further comprises a surfactant such as an ionic surfactant or a nonionic surfactant. 4. Laminated product for electrolysis according to any one of paragraphs. 1-3, in which the supply conductor is a wire mesh, metal nonwoven fabric, perforated metal sheet, expanded metal sheet, or porous metal. 5. Laminated product for electrolysis according to any one of paragraphs. 1-4, containing, as at least one surface layer of the membrane, a layer including a mixture of particles of a hydrophilic oxide and a polymer into which ion-exchange groups are introduced. 6. Laminated product for electrolysis according to any one of paragraphs. 1-5, wherein the electrolysis electrode comprises a substrate for an electrolysis electrode and a catalytic layer disposed on the substrate, wherein the catalytic layer includes at least one layer, and the total thickness of the substrate for the electrolysis electrode and the catalytic layer is 315 μm, or less. 7. The laminated article for electrolysis according to claim 6, in which the substrate contains nickel, nickel alloy, stainless steel or valve metal and has any shape of a perforated metal sheet, nonwoven fabric, porous metal, expanded metal sheet, formed by electrospinning metal porous foil, and woven metal mesh, obtained by weaving metal threads. 8. The laminated article for electrolysis according to claim 7, wherein the substrate preferably comprises at least one element selected from nickel and titanium. 9. The laminated article for electrolysis according to claim 7, wherein the substrate is preferably in the form of a perforated metal sheet or expanded metal sheet. 10. Laminated product for electrolysis according to any one of paragraphs. 6-9, in which the total thickness of the support for the electrolysis electrode and the catalytic layer is preferably 220 μm or less, more preferably 170 μm or less, even more preferably 150 μm or less, further more preferably 145 μm or less, particularly preferably 140 μm or less, even more preferably 138 µm or less, even more preferably 135 µm or less. 11. Laminated product for electrolysis according to any one of paragraphs. 6-10, in which the arithmetic mean of the surface roughness (Ra) of the substrate surface is 0.05 µm to 50 µm, preferably 0.1-10 µm, more preferably 0.1-5 µm. 12. Laminated product for electrolysis according to any one of paragraphs. 6-11, in which the electrode substrate for electrolysis has a thickness of 300 μm or less, more preferably 205 μm or less, even more preferably 155 μm or less, further more preferably 135 μm or less, even more preferably 125 μm or less, even more preferably 120 µm or less, even more preferably 100 µm or less, and further even more preferably 50 µm or less. 13. Laminated product for electrolysis according to any one of paragraphs. 6-12, in which the thickness of the substrate is preferably 5 µm or more, more preferably 15 µm or more. 14. The layered electrolysis article according to any one of the preceding claims, wherein the electrolysis electrode has a porous structure and an open porosity ratio of 5-90%. 15. The laminated article for electrolysis according to claim 14, wherein the open porosity ratio is 10-80%. 16. Laminated product for electrolysis, containing: electrolysis electrode and membrane or supply conductor in contact with the electrolysis electrode, the mechanical force applied against the adhesion force per unit mass × unit area of the electrolysis electrode on the membrane or supply conductor is from 0.005 N / (mg cm ² ) to 1.5 N / (mg cm ² ), while the applied force is measured by the following methods (i) or (ii) carried out using a tensile and compression machine: [Method (i)] prepare a nickel plate in the form of a square with a side of 200 mm, having a thickness of 1.2 mm and an arithmetic mean (Ra) of the surface roughness of 0.7 μm; the nickel plate is fixed vertically on the lower clamp of the tensile and compression machine; an ion exchange membrane, cut into a square with a side of 170 mm, is immersed in clean water for 12 hours or more, and then used for measurement; the membrane is brought into contact with a nickel plate moistened with clean water, and adhesion to the plate is provided due to the surface tension of the water, while the nickel plate and the ion-exchange membrane are positioned so that their upper ends coincide; a sample of the electrolysis electrode is cut into a square with a side of 130 mm; one side of the electrode is placed between two stainless steel plates; after positioning so that the center of the stainless steel plates is aligned with the center of the electrode, use the four clamps to secure the electrode and the plates evenly; the stainless steel plates in the center are clamped by the upper clamp of the tensile and compression machine, while the electrode is suspended; the combined block of stainless steel plates, electrode and clamps is temporarily removed from the tensile and compression testing machine and immersed in a bath containing clean water to moisten the electrode with clean water; the stainless steel plates in the center are again clamped by the upper clamp of the tensile and compression machine while hanging the electrode; the upper clamp of the tensile and compression machine is lowered and the sample of the electrolysis electrode is adhered to the surface of the ion exchange membrane by the surface tension of pure water; the size of the adhesion surface at this time is 130 mm in width and 110 mm in length; clean water from a washing bottle is sprayed entirely onto the electrode and ion-exchange membrane in order to wet the membrane and electrode again; a roll formed by winding a spongy EPDM rubber (based on ethylene propylene diene monomer) of a closed cell type having a thickness of 5 mm around a PVC pipe (outer diameter: 38 mm) is rolled once from top to bottom, lightly pressing against the electrode, removing excess clean water; the electrode is lifted at a speed of 10 mm / minute, starting measurement of the load, and the load is recorded when the size of the overlapping area of the electrode and the membrane reaches 130 mm in width and 100 mm in length; this measurement is repeated three times and the average is calculated; this average value is divided by the area of the overlapping area of the electrode and the ion-exchange membrane and by the mass of the electrode in the overlapping area with the ion-exchange membrane, calculating the force applied per unit mass × unit area (1); the measurement conditions in the measuring chamber are as follows: temperature 23 ± 2 ° C and relative humidity 30 ± 5%, while the electrode is able to hold on its own and adhere without sliding or peeling when it has been adhered to the ion-exchange membrane that has been adhered to the fixed vertically with a nickel plate, under the action of surface tension, [Method (ii)] a nickel plate identical to that in method (i) is fixed vertically on the lower clamp of the tensile and compression machine; a sample of the electrolysis electrode is cut into a square with a side of 130 mm; one side of the electrode is placed between two stainless steel plates; after positioning so that the center of the stainless steel plates coincides with the center of the electrode, use the four clamps to secure the electrode and the plates evenly; the stainless steel plates in the center are clamped by the upper clamp of the tensile and compression testing machine while hanging the electrode; the combined block of stainless steel plates, electrode, and clamps is temporarily removed from the tensile and compressive testing machine and immersed in a bath containing clean water to moisten the electrode with clean water; the stainless steel plates in the center are again clamped with the upper clamp of the tensile and compression machine while hanging the electrode; the upper clamp of the tensile and compression tester is lowered and the sample of the electrolysis electrode is adhered to the surface of the nickel plate by the surface tension of pure water; the size of the adhesion surface at this time is 130 mm in width and 110 mm in length; clean water from a wash bottle is sprinkled on the electrode and nickel plate entirely to wet the nickel plate and electrode again; the roller, identical to the roller in method (i), is rolled once from top to bottom, lightly pressing against the electrode, removing the excess of pure water; the electrode is lifted at a speed of 10 mm / minute, starting the load measurement, and the load is recorded when the size of the overlapping portion of the electrode and the nickel plate in the longitudinal direction reaches 100 mm; this measurement is repeated three times and the average is calculated; this average value is divided by the area of the overlapping portion of the electrode and the nickel plate and by the weight of the electrode in the overlapping portion with the nickel plate, calculating the force applied per unit mass × unit area (2); the measurement conditions in the measuring chamber are as follows: temperature 23 ± 2 ° C and relative humidity 30 ± 5%, with the electrode being able to hold on its own and adhere without sliding or peeling when it has been adhered to the vertically fixed nickel plate under surface tension ... 17. The electrolysis laminated article of claim 16, wherein the supply conductor is a wire mesh, a metal nonwoven fabric, a perforated metal sheet, expanded metal sheet, or a porous metal. 18. A laminated article for electrolysis according to claim 16 or 17, comprising, as at least one surface layer of the membrane, a layer including a mixture of particles of a hydrophilic oxide and a polymer into which ion-exchange groups are introduced. 19. Laminated product for electrolysis according to any one of paragraphs. 16-18, in which a liquid is disposed between the electrolysis electrode and the membrane or supply conductor. 20. Laminated product for electrolysis according to any one of paragraphs. 16-19, in which the electrolysis electrode comprises a substrate for an electrolysis electrode and a catalytic layer disposed on the substrate, wherein the catalytic layer includes at least one layer, and the total thickness of the substrate for the electrolysis electrode and the catalytic layer is 315 μm, or less. 21. A laminated article for electrolysis according to claim 20, wherein the substrate comprises nickel, nickel alloy, stainless steel or valve metal and has any shape of a perforated metal sheet, a nonwoven fabric, a porous metal, an expanded metal sheet, formed by electroforming a metal porous foil, and woven metal mesh, obtained by weaving metal threads. 22. The layered electrolysis article of claim 21, wherein the substrate preferably comprises at least one element selected from nickel and titanium. 23. The electrolysis laminated article of claim 21, wherein the substrate is preferably in the form of a perforated metal sheet or expanded metal sheet. 24. Laminated product for electrolysis according to any one of paragraphs. 20-23, in which the total thickness of the support for the electrolysis electrode and the catalytic layer is preferably 220 μm or less, more preferably 170 μm or less, even more preferably 150 μm or less, further more preferably 145 μm or less, particularly preferably 140 μm or less, even more preferably 138 µm or less, even more preferably 135 µm or less. 25. Laminated product for electrolysis according to any one of paragraphs. 20-24, in which the arithmetic mean of the surface roughness (Ra) of the substrate surface is 0.05 µm to 50 µm, preferably 0.1-10 µm, more preferably 0.1-5 µm. 26. Laminated product for electrolysis according to any one of paragraphs. 20-25, in which the electrode substrate for electrolysis has a thickness of 300 μm or less, more preferably 205 μm or less, even more preferably 155 μm or less, further more preferably 135 μm or less, even more preferably 125 μm or less, even more preferably 120 µm or less, even more preferably 100 µm or less, and further even more preferably 50 µm or less. 27. Laminated product for electrolysis according to any one of paragraphs. 20-26, in which the thickness of the substrate is preferably 5 µm or more, more preferably 15 µm or more. 28. Laminated product for electrolysis according to any one of paragraphs. 20-27, in which the electrolysis electrode has a porous structure and an open porosity ratio of 5-90%. 29. The laminated article for electrolysis according to claim 28, wherein the open porosity ratio is 10-80%.

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