JP2012140653A - Ion exchange membrane method type electrolytic cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ion exchange membrane method type electrolytic cell in which the renewal cost of a cathode is low, and the electric energy as small a loss as possible.SOLUTION: The ion exchange membrane method type electrolytic cell is configured in such a way that a coil cushion material is installed on an old cathode in which an electrode catalyst is carried on an expand metal type substrate of a narrow gap type electrolytic cell, a new cathode with the electrode catalyst carried thereon is installed on the coil cushion material, and the new electrode is disposed so as to be in contact with the ion exchange membrane. A new cathode having such configuration is preferable that the electrode catalyst is carried on an expand metal in which the knurl width is 0.1-1.0 mm, the minor axis is 0.5-5.0 mm, the major axis is 1.0-10 mm, the plate thickness is 0.1-1.0 mm, and the aperture ratio is 48-60%.

Description

  The present invention relates to an ion exchange membrane method electrolytic cell. In more detail, an ion exchange membrane and an ion exchange membrane having a configuration in which an ion exchange membrane and a cathode are arranged at regular intervals, a so-called narrow gap type ion exchange membrane electrolytic cell, and a modified anode The present invention relates to an ion exchange membrane electrolytic cell having a structure in which cathodes are in close contact with each other, ie, a so-called zero gap type ion exchange membrane electrolytic cell.

  The ion exchange membrane method electrolytic cell of the present invention is an ion exchange membrane method electrolytic cell used in the electrolytic industry represented by chloralkali electrolysis, and the cathode renewal cost is remarkably reduced when renewing the cathode after its long-term operation. The present invention also relates to a novel ion exchange membrane electrolytic cell that exhibits a significant voltage reduction effect after cathode renewal.

The ion exchange membrane method electrolytic industry represented by chloralkali electrolysis plays an important role as a raw material industry. In the electrolytic industry, there are cases where the ion exchange membrane method electrolytic cell (hereinafter referred to as “electrolytic cell”) is abbreviated. ) Is the center of technology.
For example, it is known that the bipolar electrolytic cell developed by the present applicant and the TMB type ion exchange membrane electrolytic cell can be stably operated for a long time at a high current density of 5 kA / m ² (for example, Non-patent document 1).

  A great amount of electric energy is consumed for the operation of the electrolytic cell. The main causes of consumption of electric energy include the theoretical decomposition voltage due to the electrolytic reaction of both chlorine generation and hydrogen generation, overvoltage due to hydrogen generation on the cathode, overvoltage due to chlorine generation on the anode, and cathode The voltage loss due to the electrical resistance of the electrolyte and ion exchange membrane between the anode and the anode is known.

In the cathode used in the electrolytic industry, the catalytic activity for hydrogen generation decreases with the operation period, the cathode overvoltage increases with the operation period, and the consumption of electric energy increases. For this reason, after a certain period of operation, a reactivation process or replacement of the cathode itself is required.
In addition to the TMB type ion exchange membrane method electrolytic cell, a narrow gap type ion exchange membrane method electrolytic cell, that is, an ion exchange membrane method electrolytic cell having a configuration in which an ion exchange membrane and a cathode are arranged at a predetermined interval Widely used.

FIG. 1 shows an example of the structure on the cathode chamber side of an ion exchange membrane method electrolytic cell having a configuration in which an ion exchange membrane and a cathode are arranged at a predetermined interval.
In FIG. 1, the cathode (1) and the ion exchange membrane (2) are 1 to 3 mm apart, and the distance is adjusted by the thickness of the gasket (4). As described above, an ion exchange membrane electrolytic cell having a configuration in which the cathode (1) and the ion exchange membrane (2) are arranged at a predetermined interval is generally called a narrow gap type electrolytic cell. In contrast, an electrolytic cell having a configuration in which an ion exchange membrane and a cathode are arranged in close proximity to each other is called a zero gap type electrolytic cell.

  In the narrow gap type electrolytic cell, it is important to keep the distance between the cathode (1) and the ion exchange membrane (2) uniform. Since the cathode (1) is firmly bonded to the rib (3), the catalytic activity for hydrogen generation of the cathode (1) is lowered after long-term operation, and the cathode (1) 1) and the cathode rib (3) cut the joint and remove the cathode, then either the joint (3) must be restored and a new cathode must be installed or the entire cathode chamber must be replaced. Such costs are enormous.

Moreover, in this narrow gap type electrolytic cell, the loss of the electric energy resulting from the electrical resistance loss for the space | interval of a cathode (1) and an ion exchange membrane (2) has arisen.
Therefore, an ion exchange membrane electrolytic cell has been desired that has a low cost for renewal of the cathode and has as little electrical energy loss as possible.

Soda Technical Handbook 2009 (Japan Soda Industry Association, issued on June 30, 2009; page 34, tables 1.15 and 48, figure 1.34)

  An object of the present invention is to provide an ion exchange membrane electrolytic cell in which the renewal cost of the cathode is low and the loss of electric energy is as small as possible.

  Thus, in the present invention, the coil cushion material is installed on the original cathode (hereinafter referred to as “old cathode”) of the narrow gap type ion exchange membrane electrolytic cell, and an electrode is formed on the coil cushion material. An ion exchange membrane method electrolytic cell is provided in which a new cathode carrying a catalyst is installed and the new cathode is in contact with the ion exchange membrane.

  Further, according to another aspect of the present invention, a coil cushion material is installed on the old cathode of the narrow gap type ion exchange membrane electrolytic cell having the old cathode, and then an electrode catalyst is supported on the coil cushion material. Provided is a method for remodeling a narrow gap type ion exchange membrane electrolytic cell characterized by installing a new cathode and bringing the new cathode into contact with an ion exchange membrane.

  The ion exchange membrane method electrolytic cell of the present invention is a modified product of an existing narrow gap type ion exchange membrane method electrolytic cell. That is, after operating the narrow gap type ion exchange membrane electrolytic cell for a long period of time, without replacing the cathode whose catalytic activity for hydrogen generation has deteriorated, the coil cushion (1) is placed on the cathode (1) as shown in FIG. 5), a new cathode (6) carrying a catalyst (hereinafter abbreviated as “new cathode”) is placed thereon, and the new cathode (6) is brought into contact with the ion exchange membrane (2). The present invention relates to a combination of a so-called zero gap ion exchange membrane electrolytic cell and a narrow gap ion exchange membrane electrolytic cell.

  In the ion exchange membrane electrolytic cell of the present invention, the electrode is obtained by attaching a new cathode (6) as shown in FIG. 2 without replacing the old cathode (1) of the narrow gap type ion exchange membrane electrolytic cell. In addition to reducing the overvoltage of hydrogen generation, a conventional coil (5) is interposed between the old cathode (1) and the new cathode (6). The electric energy consumed is reduced by eliminating the voltage applied to the gap as a zero gap state in which the gap existing between the ion exchange membrane (2) is eliminated.

  In addition, by applying a predetermined pressure from the coil cushion material (5) to the ion exchange membrane (2) through the new cathode (6), the coil rebound force of the coil cushion material (5) is set to a desired surface pressure. The contact pressure between the cathode (6) and the ion exchange membrane (2) becomes uniform, and the ion exchange membrane (2) is not damaged by the excessive contact pressure.

It is sectional drawing which shows an example of the structure by the side of the cathode chamber of the conventional narrow gap type ion exchange membrane method electrolytic cell. It is sectional drawing which shows an example of the structure of the ion exchange membrane method electrolytic cell of this invention. It is a perspective view which shows an example of the metal frame used for a coil cushion material. It is sectional drawing which shows an example of the metal coil body used for a coil cushion material. It is a perspective view which shows an example of a coil cushion material. It is sectional drawing which shows the structure which fixed the new cathode to the old cathode through the coil cushion material with the pin. It is the top view which installed the coil cushion material on the old cathode. It is an assembly drawing of the ion exchange membrane method electrolytic cell of this invention. It is an assembly drawing of the conventional TMB type ion exchange membrane method electrolytic cell.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.
In the following description, an ion exchange membrane method electrolytic cell used for salt electrolysis will be described as an example. Of course, it can be suitably used.
Moreover, the ion exchange membrane method electrolytic cell of the present invention can be suitably used for both a bipolar ion exchange membrane method electrolytic cell and a monopolar ion exchange membrane method electrolytic cell.
The ion exchange membrane electrolytic cell of the present invention corresponds to a modified product of an existing narrow gap electrolytic cell, but the anode chamber is not particularly required to be modified, and only the cathode chamber may be modified.

The ion exchange membrane electrolytic cell of the present invention shown in FIG. 2 is obtained by modifying the cathode chamber of an existing narrow gap ion exchange membrane electrolytic cell as described below.
First, a coil cushion material (5) is installed on the cathode (1). In the following description, the cathode (1) installed in the existing narrow gap type ion exchange membrane electrolytic cell is shown as the old cathode (1). Next, a new cathode (6) is installed on the coil cushion material (5). By simply applying such a simple modification to the existing narrow gap ion exchange membrane electrolytic cell, the renewal cost of the cathode is extremely low, and the power consumption during electrolytic cell operation can be reduced. Is obtained.

Hereinafter, the ion exchange membrane method electrolytic cell of the present invention will be described in more detail.
In the existing narrow gap type ion exchange membrane electrolytic cell used in the present invention, the replacement time of the old cathode (1) (cathode electrolysis operation time) is not particularly limited. Replacing the old cathode (1), which has deteriorated the hydrogen generating catalyst and required renewal of the cathode, is economically preferable because energy loss can be reduced by returning the hydrogen generating catalyst activity of the cathode.

Since the hydrogen generation reaction of the electrolytic cell of the present invention occurs at the new cathode (6), it can be used as it is even if the hydrogen generation catalyst of the old cathode (1) is deteriorated. However, the deteriorated catalyst on the old cathode (1) may fall off during operation, resulting in damage to the quality of the caustic liquid or damage to the ion exchange membrane (2). Remove the deteriorated catalyst before remodeling. It is desirable to do.
For removing the deteriorated catalyst, a method of physically removing it by polishing or the like, a method of chemically removing it by dissolving it in a mineral acid-containing liquid, or the like is used.

As the coil cushion material (5) (FIG. 2) installed on the old cathode (1), all conventionally known coil cushion materials can be suitably used. For example, if the coil cushion material (5) shown in FIG. 5 manufactured by winding the metal coil body (8) shown in FIG. 4 around the metal frame (7) having the structure shown in FIG. It is preferable because it can be installed.
As the material of the metal frame (7), a material having high corrosion resistance such as nickel or stainless steel is preferably used. The diameter of the frame is preferably 1 to 3 mm, more preferably 1 to 2 mm. If the diameter of the frame is less than 1 mm, the strength is insufficient and handling becomes difficult. On the other hand, when the thickness exceeds 3 mm, the material cost deteriorates, and the frame is excessively pressed against the ion exchange membrane (2) and the new cathode (6), and the ion exchange membrane (2) and the new cathode (6) are damaged. There is a case.

A coil cushion is configured by winding a metal coil body (8) around a metal frame. The number of windings of the coil body (8) is preferably 3 to 9 times / cm, more preferably 6 to 7 times / cm. is there. If the number of turns of the coil is too small, the reaction force may be insufficient or the coil may fall during compression and the elasticity may be insufficient. On the contrary, if the number of windings is too large, the reaction force may be excessive or the handling property may be deteriorated.
As the metal coil body (8), those having high corrosion resistance and high electrical conductivity such as nickel and stainless steel are preferably used. Moreover, the thing which coat | covered the surface of the coil body excellent in electroconductivity, such as copper, with nickel, and improved corrosion resistance can also be used conveniently.

  Although there is no restriction | limiting in the method of manufacturing a metal coil body (8), For example, it can manufacture by roll-processing a nickel and stainless steel wire, and shape | molding it helically. The diameter of the wire used is preferably 0.1 to 2.0 mm, more preferably 0.1 to 1.0 mm. If the wire is too thin, the strength of the manufactured coil body is insufficient, and the elastic repulsion force becomes insufficient due to plastic deformation during use. On the other hand, if it is too thick, molding becomes difficult, or even if it can be molded, an excessive elastic repulsion force is obtained, and the desired coil cushion material (5) cannot be obtained.

  The ring diameter (apparent diameter of the coil) of the metal coil body (8) is not particularly limited, but is usually 3 to 10 mm. If the ring diameter is smaller than 3 mm, the compressible thickness of the elastic mat is insufficient, and the effects of the present invention may not be exhibited. On the contrary, if the ring diameter is larger than 10 mm, the handling property may be deteriorated, and the elastic repulsion may be insufficient due to plastic deformation during compression.

The coil thickness of the metal coil body (8) refers to the length indicated by the double-headed arrow a in FIG. 2, but the thickness is not particularly limited, and is usually 1 to 10 mm, preferably 2 to 5 mm. . If the coil is too thick, the elastic repulsion force at the time of compression is insufficient, and the effects of the present invention may not be obtained. On the other hand, if it is too thin, the elastic repulsion force during compression becomes abnormally strong, and the ion exchange membrane may be damaged.
The method of installing the coil cushion material (5) on the old cathode (1) is not particularly limited as long as the coil cushion material (5) is fixed on the old cathode (1) as shown in FIG. Absent. For example, at least a part of the metal frame of the coil cushion material (5) may be welded to the old cathode (1).

  As the new cathode (6) (FIGS. 2 and 6) used in the present invention, a hydrogen generating electrode that generates hydrogen during electrolysis is widely known as a cathode for salt electrolysis. A so-called active cathode carrying a generating electrode catalyst is applied. Currently, various active cathodes have been developed and put to practical use, and any of these active cathodes can be used in the present invention (see, for example, JP-A-2005-330575).

  As the metal substrate of the new cathode (6), when using a conventional nickel expanded metal substrate, step size: 2 mm, minor diameter: 6 mm, major diameter: 15 mm, plate thickness: about 2 mm, a conventional nickel expanded metal substrate, In contact between the new cathode (6) and the ion exchange membrane (2), there is a place where the rigidity of the mesh portion of the new cathode is high and the pressure applied to the ion exchange membrane is partially increased, the ion exchange membrane (2) The degree of damage is large and the frequency of damage increases.

  Therefore, as the metal substrate of the new cathode (6), the step width is 0.1 mm or more and 1 mm or less, the minor axis is 0.5 mm or more and 5.0 mm or less, the major axis is 1.0 mm or more and 10 mm or less, and the plate thickness is 0.1 mm or more. An expanded metal type mesh of 1.0 mm or less is preferably used. The new cathode (6) carrying the catalyst on the expanded metal mesh having such specifications is used, and the mesh of the new cathode (6) is brought into contact with the new cathode (6) and the ion exchange membrane (2). It is preferable to reduce the rigidity of the portion, reduce the pressure applied to the ion exchange membrane (2), reduce the degree of damage to the ion exchange membrane, and reduce the frequency of damage.

The area of one hole of the expanded metal electrode is approximated by (minor axis × major axis) / 2, and is defined as 0.25 to 25 mm ² according to the minor axis and the major axis.
However, if the area of one hole of the electrode is too small, the escape of gas generated from the electrode is worsened. On the contrary, if the area is too large, the strength of the electrode itself is lowered, which is not preferred. The area of one hole of the electrode is preferably in the range of 1.0 to 10 mm ² .
Further, if the aperture ratio of the electrode is too small, it is not preferable because the escape of gas generated from the electrode is worsened, and if it is too large, the strength of the electrode itself is decreased. The electrode aperture ratio is preferably 48 to 60%.

  As shown in FIGS. 6 and 7, the new cathode (6) is installed on the coil cushion material installed on the old cathode (1). There is no particular limitation as long as it can be fixed to the old cathode (1). For example, as shown in FIG. 6, the pin (9) may be fixed to the hole of the new cathode (6) and the hole of the old cathode (1) opened at a place not penetrating the coil cushion material (5). As the pin (9), a pin made of a fluororesin such as Teflon (registered trademark) is preferably used.

Although the anode is not shown in FIG. 2, the anode is located on the opposite side of the new cathode (6) through the ion exchange membrane (2) and is in contact with the ion exchange membrane (2).
In order to apply a predetermined pressure to the ion exchange membrane (2) from the coil cushion material (5) through the new cathode (6) by this contact, the elastic repulsive force of the coil cushion material (5) is set to an average surface pressure of 7 What is necessary is just to adjust to -17kPa. The elastic repulsion force of the coil cushion material (5) can be adjusted by the coil thickness. That is, when the relationship between the coil thickness of the coil cushion material (5) to be used and the elastic repulsion force is measured in advance and the ion exchange membrane electrolytic cell of the present invention is assembled, a desired elastic repulsion force can be obtained. The coil thickness may be adjusted. The method for adjusting the coil thickness is not particularly limited, but for example, it is convenient to adjust the thickness by the thickness of the gasket (4).

  By applying a predetermined pressure from the coil cushion material (5) to the ion exchange membrane (2) through the new cathode (6), the elastic repulsion force of the coil cushion material (5) is adjusted to 7 to 17 kPa as an average surface pressure. For example, the contact pressure between the new cathode (6) of the present invention and the ion exchange membrane (2) becomes uniform, and the ion exchange membrane (2) is not damaged by the excessive contact pressure. In particular, by adjusting the elastic repulsive force of the coil cushion material (5) to a surface pressure of the lower limit value of 7 kPa or more, it is possible to prevent the interval between the ion exchange membrane, the cathode and the anode from being increased, and the electrolytic cell voltage Can be reduced.

The anode is not particularly limited, and a conventionally known anode may be used as appropriate. For example, a chlorine generating electrode in which a chlorine generating electrode catalyst such as iridium oxide and / or ruthenium oxide is supported on an expanded metal substrate made of titanium is widely known.
The ion exchange membrane (2) is not particularly limited, and a conventionally known one may be used as appropriate. For example, an ion exchange membrane made of a fluororesin film having a cation exchange group such as a sulfonic acid group or a carboxylic acid group is widely known.

The present invention will be specifically described with reference to the following examples, but the present invention is not limited to these examples.
(Narrow gap ion exchange membrane electrolytic cell before cathode exchange)
Sodium chloride was electrolyzed using a TMB ion exchange membrane electrolytic cell as a narrow gap electrolytic cell.

Example 1
In the TMB type ion exchange membrane method electrolytic cell, continuous operation for 6 years was carried out twice at a current density of 5 kA / dm ² for a total of 12 years. A coil cushion material and a new cathode were installed on the old cathode of the electrolytic cell.
Specifically, a nickel frame having a diameter of 1.2 mm was assembled into the structure shown in FIG. 3 to produce a metal frame (7). A metal coil (8) produced by roll-pressing a 0.1 mm diameter nickel wire rod is wound around a metal frame (7) in a pincushion shape as shown in FIG. 4, and a coil cushion material as shown in FIG. Was made. The number of windings of the metal coil (8) was 60 times / dm ² . As shown in FIG. 7, the coil cushion material was installed on the old cathode.

The coil density of the coil cushion material was 3.0 g / dm ² and the coil thickness after compression was 2.5 mm.
A new cathode (6) was produced as follows. Fine mesh nickel expanded metal with step size: 0.2 mm, minor axis: 1.0 mm, major axis: 2.0 mm, plate thickness: 0.2 mm (minor axis length 1400 mm, major axis direction length 390 mm) Was used as a substrate, and this substrate was etched with a 10 wt% hydrochloric acid solution at a temperature of 50 ° C. for 15 minutes, then washed with water and dried.

Subsequently, the platinum content was adjusted to a molar ratio of 0.00 using dinitrodiammine platinum nitrate solution (manufactured by Tanaka Kikinzoku, platinum concentration: 4.5 wt%, solvent: 8 wt% nitric acid solution), nickel nitrate hexahydrate and water. 5. A coating solution in which the total concentration of platinum and nickel in the mixed solution was 5% by weight in terms of metal was prepared.
Next, this coating solution is applied to the entire surface of the fine mesh substrate with a brush, dried at 80 ° C. for 15 minutes in a hot air dryer, and then subjected to 15 ° C. at 500 ° C. under air circulation using a box-type electric furnace. Pyrolyzed for minutes. This series of operations was repeated 5 times, and the electrode coated with the platinum-nickel alloy was used as the new cathode (6) of the modified TMB type ion exchange membrane electrolytic cell of the present application.

The old cathode (1), the coil cushion material (5) and the new cathode (6) were assembled in the structure shown in FIG. The coil cushion material (5) was fixed by welding the four corners of the metal frame to the old cathode (1). A Teflon (registered trademark) pin (9) is passed through a hole with a diameter of 3.5 mm opened at a total of six locations on the left, right, upper, middle, and lower portions 30 mm away from the outer frame of the old cathode (1) and the new cathode (6). This fixed the new cathode (6).
The thickness of the gasket (4) was adjusted, and the coil width was set such that the elastic repulsion of the coil cushion material (5) was 9.8 kPa.

Using the DSE (registered trademark) manufactured by Permerek Electrode Co., Ltd. as the anode and the Flemion (registered trademark) manufactured by Asahi Glass Co., Ltd. as the ion exchange membrane, as shown in FIG. The material (5), the new cathode (6), the ion exchange membrane (2), and the anode (10) were assembled to assemble a modified TMB type ion exchange membrane method electrolytic cell. The pressure in the cathode chamber is set 5 kPa higher than the pressure in the anode chamber, the ion exchange membrane is brought into close contact with the anode surface, the current density is 5 kPa / m ² , the anode chamber outlet brine concentration: 200 to 210 g / L, the cathode chamber outlet water Sodium chloride aqueous solution concentration: 31 to 33% by weight, temperature: 90 ° C., a salt electrolysis test was performed, and an electrolysis voltage was measured. The electrolysis voltage changed around 3.0.

Comparative Example 1
A comparative test of salt electrolysis was conducted using a conventional TMB electrolytic cell having the structure shown in FIG.
After the operation is completed, the old cathode (1) of the TMB type ion exchange membrane method electrolytic cell is removed, and the plate thickness is 1.0 mm, the major axis is 8.0 mm, the minor axis is 4.0 mm, and the step size is 1.0 mm. It was updated to a new cathode (11) in which an electrode catalyst was supported on a nickel expanded metal substrate (length in the minor axis direction 1400 mm, length in the major axis direction 1200 mm).

  As shown in FIG. 9, using DSE (registered trademark) manufactured by Permerek Electrode Co., Ltd. as the anode (2) and using Flemion (registered trademark) manufactured by Asahi Glass Co., Ltd. as the ion exchange membrane (2), A new cathode (11), ion exchange membrane (2), and anode (10) are assembled, a TMB type ion exchange membrane method electrolytic cell is assembled, and the pressure in the cathode chamber is set 5 kPa higher than the pressure in the anode chamber. The exchange membrane was adhered to the anode surface.

The cathode (11) and the ion exchange membrane (2) were 2.0 mm apart, and the thickness of the gasket was the same 2.0 mm.
A sodium chloride electrolysis test was performed at a current density of 5 kA / m ² , an anode chamber outlet salt water concentration: 200 to 210 g / L, a sodium hydroxide aqueous solution concentration of 31 to 33% by weight, a temperature: 90 ° C., and an electrolysis voltage was measured. did. The electrolysis voltage changed in the vicinity of 3.2 V, and changed by 0.2 V higher than that in Example 1.

The ion exchange membrane method electrolytic cell of the present invention reduces the problem of the conventional narrow gap type electrolytic cell, the cost of replacing the cathode, and keeps the energy required for electrolysis in the electrolytic industry stably low over a long period of time. The energy saving performance of the zero gap type electrolytic cell can be obtained.
Therefore, the ion exchange membrane method electrolytic cell of the present invention is used in the electrolytic industry represented by chloralkali electrolysis such as salt electrolysis. Other than salt electrolysis, for example, it can be suitably used for potassium chloride aqueous solution electrolysis and alkaline water electrolysis.

1: Cathode or old cathode 2: Ion exchange membrane 3: Cathode rib 4: Gasket 5: Coil cushion material 6: New cathode 7: Metal frame 8: Metal coil body 9: Fixing pin 10: Anode 11: New cathode

Claims (6)

  A coil cushion material is installed on the old cathode of the narrow gap type ion exchange membrane electrolytic cell having the old cathode, a new cathode carrying an electrode catalyst is installed on the coil cushion material, and the new cathode is An ion exchange membrane electrolytic cell characterized by being in contact with an ion exchange membrane.   The new cathode has a step width of 0.1 mm to 1.0 mm, a minor axis of 0.5 mm to 5.0 mm, a major axis of 1.0 mm to 10 mm, and a plate thickness of 0.1 mm to 1.0 mm. The ion exchange membrane method electrolytic cell according to claim 1, wherein an electrode catalyst is supported on an expanded metal having an opening ratio of 48 to 60%.   The ion exchange membrane method electrolytic cell according to claim 1 or 2, wherein the coil cushion material has a structure in which a metal coil body is wound around a metal frame.   The ion exchange membrane method electrolytic cell according to claim 3, wherein the number of turns of the metal coil body wound around the metal frame is 3 to 9 times / cm.   The ion exchange membrane method electrolytic cell according to any one of claims 1 to 4, wherein an elastic repulsion force of the coil cushion material is adjusted to 7 to 17 kPa as an average surface pressure.   A coil cushion material is installed on the old cathode of the narrow gap type ion exchange membrane electrolytic cell having the old cathode, and then a new cathode carrying an electrode catalyst is installed on the coil cushion material, and ion exchange with the new cathode is performed. A method of remodeling a narrow gap type ion exchange membrane electrolytic cell characterized by contacting a membrane.

Images