CN112095119A - Ion exchange membrane, method for producing ion exchange membrane, and electrolytic cell - Google Patents
Ion exchange membrane, method for producing ion exchange membrane, and electrolytic cell Download PDFInfo
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- CN112095119A CN112095119A CN202010542472.5A CN202010542472A CN112095119A CN 112095119 A CN112095119 A CN 112095119A CN 202010542472 A CN202010542472 A CN 202010542472A CN 112095119 A CN112095119 A CN 112095119A
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- exchange membrane
- ion exchange
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- 239000003014 ion exchange membrane Substances 0.000 title claims abstract description 133
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 20
- 239000011230 binding agent Substances 0.000 claims abstract description 65
- 239000011247 coating layer Substances 0.000 claims abstract description 60
- 239000011248 coating agent Substances 0.000 claims abstract description 56
- 238000000576 coating method Methods 0.000 claims abstract description 56
- 239000010954 inorganic particle Substances 0.000 claims abstract description 49
- 239000012528 membrane Substances 0.000 claims abstract description 38
- 229920000642 polymer Polymers 0.000 claims description 93
- 229910052731 fluorine Inorganic materials 0.000 claims description 60
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 claims description 59
- 239000011737 fluorine Substances 0.000 claims description 59
- 238000005342 ion exchange Methods 0.000 claims description 43
- 238000000034 method Methods 0.000 claims description 43
- 239000007788 liquid Substances 0.000 claims description 39
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 claims description 28
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- 229910021480 group 4 element Inorganic materials 0.000 claims description 9
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- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 9
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- 239000000243 solution Substances 0.000 description 9
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- MHNPWFZIRJMRKC-UHFFFAOYSA-N 1,1,2-trifluoroethene Chemical compound F[C]=C(F)F MHNPWFZIRJMRKC-UHFFFAOYSA-N 0.000 description 3
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- 125000000391 vinyl group Chemical group [H]C([*])=C([H])[H] 0.000 description 3
- BQCIDUSAKPWEOX-UHFFFAOYSA-N 1,1-Difluoroethene Chemical compound FC(F)=C BQCIDUSAKPWEOX-UHFFFAOYSA-N 0.000 description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 2
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 2
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 239000003054 catalyst Substances 0.000 description 2
- 238000005341 cation exchange Methods 0.000 description 2
- 230000008859 change Effects 0.000 description 2
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- 229910052801 chlorine Inorganic materials 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
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- 230000003301 hydrolyzing effect Effects 0.000 description 2
- 238000003475 lamination Methods 0.000 description 2
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- 239000002994 raw material Substances 0.000 description 2
- 229910001925 ruthenium oxide Inorganic materials 0.000 description 2
- WOCIAKWEIIZHES-UHFFFAOYSA-N ruthenium(iv) oxide Chemical compound O=[Ru]=O WOCIAKWEIIZHES-UHFFFAOYSA-N 0.000 description 2
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- 238000009987 spinning Methods 0.000 description 2
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- 239000010936 titanium Substances 0.000 description 2
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 description 2
- 229920002554 vinyl polymer Polymers 0.000 description 2
- VQUGQIYAVYQSAB-UHFFFAOYSA-N 1,1,2,2-tetrafluoro-2-(1,2,2-trifluoroethenoxy)ethanesulfonyl fluoride Chemical compound FC(F)=C(F)OC(F)(F)C(F)(F)S(F)(=O)=O VQUGQIYAVYQSAB-UHFFFAOYSA-N 0.000 description 1
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- 229920001780 ECTFE Polymers 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 description 1
- 239000002033 PVDF binder Substances 0.000 description 1
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 1
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 description 1
- 229910026551 ZrC Inorganic materials 0.000 description 1
- OTCHGXYCWNXDOA-UHFFFAOYSA-N [C].[Zr] Chemical compound [C].[Zr] OTCHGXYCWNXDOA-UHFFFAOYSA-N 0.000 description 1
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- 125000004432 carbon atom Chemical group C* 0.000 description 1
- 125000003262 carboxylic acid ester group Chemical group [H]C([H])([*:2])OC(=O)C([H])([H])[*:1] 0.000 description 1
- 125000002091 cationic group Chemical group 0.000 description 1
- 229910000420 cerium oxide Inorganic materials 0.000 description 1
- KYKAJFCTULSVSH-UHFFFAOYSA-N chloro(fluoro)methane Chemical compound F[C]Cl KYKAJFCTULSVSH-UHFFFAOYSA-N 0.000 description 1
- 239000000084 colloidal system Substances 0.000 description 1
- 230000008602 contraction Effects 0.000 description 1
- HTXDPTMKBJXEOW-UHFFFAOYSA-N dioxoiridium Chemical compound O=[Ir]=O HTXDPTMKBJXEOW-UHFFFAOYSA-N 0.000 description 1
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- 125000004185 ester group Chemical group 0.000 description 1
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- 239000010419 fine particle Substances 0.000 description 1
- 125000001153 fluoro group Chemical group F* 0.000 description 1
- XUCNUKMRBVNAPB-UHFFFAOYSA-N fluoroethene Chemical compound FC=C XUCNUKMRBVNAPB-UHFFFAOYSA-N 0.000 description 1
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- 125000004435 hydrogen atom Chemical group [H]* 0.000 description 1
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- BMMGVYCKOGBVEV-UHFFFAOYSA-N oxo(oxoceriooxy)cerium Chemical compound [Ce]=O.O=[Ce]=O BMMGVYCKOGBVEV-UHFFFAOYSA-N 0.000 description 1
- GNRSAWUEBMWBQH-UHFFFAOYSA-N oxonickel Chemical compound [Ni]=O GNRSAWUEBMWBQH-UHFFFAOYSA-N 0.000 description 1
- 125000006551 perfluoro alkylene group Chemical group 0.000 description 1
- 125000005010 perfluoroalkyl group Chemical group 0.000 description 1
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 1
- 239000004300 potassium benzoate Substances 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
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- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 1
- 229910010271 silicon carbide Inorganic materials 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 235000002639 sodium chloride Nutrition 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
- 150000003457 sulfones Chemical class 0.000 description 1
- OBTWBSRJZRCYQV-UHFFFAOYSA-N sulfuryl difluoride Chemical group FS(F)(=O)=O OBTWBSRJZRCYQV-UHFFFAOYSA-N 0.000 description 1
- TXEYQDLBPFQVAA-UHFFFAOYSA-N tetrafluoromethane Chemical compound FC(F)(F)F TXEYQDLBPFQVAA-UHFFFAOYSA-N 0.000 description 1
- XOLBLPGZBRYERU-UHFFFAOYSA-N tin dioxide Chemical compound O=[Sn]=O XOLBLPGZBRYERU-UHFFFAOYSA-N 0.000 description 1
- 229910001887 tin oxide Inorganic materials 0.000 description 1
- 238000004448 titration Methods 0.000 description 1
- 239000004034 viscosity adjusting agent Substances 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
- 238000009736 wetting Methods 0.000 description 1
- 229910052726 zirconium Inorganic materials 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
- C25B13/00—Diaphragms; Spacing elements
- C25B13/04—Diaphragms; Spacing elements characterised by the material
- C25B13/08—Diaphragms; Spacing elements characterised by the material based on organic materials
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05D7/00—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials
- B05D7/24—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials for applying particular liquids or other fluent materials
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
- C25B1/00—Electrolytic production of inorganic compounds or non-metals
- C25B1/01—Products
- C25B1/34—Simultaneous production of alkali metal hydroxides and chlorine, oxyacids or salts of chlorine, e.g. by chlor-alkali electrolysis
- C25B1/46—Simultaneous production of alkali metal hydroxides and chlorine, oxyacids or salts of chlorine, e.g. by chlor-alkali electrolysis in diaphragm cells
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
- C25B13/00—Diaphragms; Spacing elements
- C25B13/02—Diaphragms; Spacing elements characterised by shape or form
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
- C25B9/00—Cells or assemblies of cells; Constructional parts of cells; Assemblies of constructional parts, e.g. electrode-diaphragm assemblies; Process-related cell features
- C25B9/17—Cells comprising dimensionally-stable non-movable electrodes; Assemblies of constructional parts thereof
- C25B9/19—Cells comprising dimensionally-stable non-movable electrodes; Assemblies of constructional parts thereof with diaphragms
- C25B9/23—Cells comprising dimensionally-stable non-movable electrodes; Assemblies of constructional parts thereof with diaphragms comprising ion-exchange membranes in or on which electrode material is embedded
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Wood Science & Technology (AREA)
- Electrolytic Production Of Non-Metals, Compounds, Apparatuses Therefor (AREA)
- Manufacture Of Macromolecular Shaped Articles (AREA)
Abstract
The invention provides an ion exchange membrane, a method for producing the same, and an electrolytic cell, wherein the ion exchange membrane can reduce electrolytic voltage when supplied to electrolysis, and has small influence of impurities in an electrolyte solution on electrolytic performance, and can stably exert the electrolytic performance. The ion exchange membrane of the present invention has: the coating layer comprises inorganic particles and a binder, wherein the mass ratio of the binder in the coating layer is 0.3 to 0.9 relative to the total mass of the inorganic particles and the binder, and the coating rate of the coating layer on the membrane main body is 50% or more.
Description
Technical Field
The present invention relates to an ion exchange membrane, a method for producing an ion exchange membrane, and an electrolytic cell.
Background
Fluorine-containing ion exchange membranes are excellent in heat resistance, chemical resistance, and the like, and are widely used in various applications as electrolytic separators for alkali metal chloride electrolysis, ozone generation electrolysis, fuel cells, water electrolysis, hydrochloric acid electrolysis, and the like, and are expanding to new applications.
Among these, in the electrolysis for producing chlorine and alkali metal chloride of alkali metal hydroxide, the ion exchange membrane method has become the mainstream in recent years. In addition, in order to reduce the unit of power consumption, in the alkali metal chloride electrolysis by the ion exchange membrane method, a natural circulation type zero-pitch electrolytic cell in which an ion exchange membrane is in close contact with an anode and a cathode has been mainstream.
Various properties are required for an ion exchange membrane used in the electrolysis of alkali metal chloride. Among them, high production efficiency with respect to the flowing current is required particularly from the viewpoint of productivity; low electrolysis voltage is required from the viewpoint of economy. In the alkali metal chloride electrolysis, when the industrial-grade electrolysis is performed, if the electrolysis voltage can be slightly reduced and the current efficiency can be slightly improved, significant energy saving can be achieved.
In alkali chloride electrolysis, it is generally known that a gas generated by an electrolysis reaction adheres to the surface of an ion exchange membrane, thereby increasing the electrolysis voltage. As a countermeasure, for example, patent document 1 proposes that a layer (surface layer) containing a hydrophilic binder and inorganic particles is provided on the surface of the membrane, whereby adhesion of gas to the surface of the ion exchange membrane is suppressed and the electrolytic voltage is reduced.
In addition, if impurities such as metals are present in the aqueous solution of alkali metal chloride and accumulated inside the cation exchange membrane, an increase in electrolytic voltage, a decrease in current efficiency, and an increase in impurity concentration in alkali occur. In particular, since I is an impurity which is difficult to reduce even if the electrolytic solution is treated in advance, unlike cationic impurities such as Ca and Mg, a cation exchange membrane which is not easily affected by I has been desired. As a countermeasure, for example, patent document 2 proposes the following: by using the specific inorganic fine particles as the coating layer applied to the ion exchange membrane, the influence of impurities in the electrolytic solution on the electrolytic performance is small, and stable electrolytic performance can be obtained.
Documents of the prior art
Patent document
Patent document 1: international publication No. 2015/098769
Patent document 2: japanese patent laid-open No. 2014-58707
Disclosure of Invention
Problems to be solved by the invention
In order to hydrophilize the membrane surface and obtain a sufficient effect of preventing gas adhesion, it is required to increase the mass ratio of the binder to the total of the inorganic particles and the binder contained in the surface layer and to form a uniform surface layer on the membrane surface.
However, in the method described in patent document 1, when the mass ratio of the binder is increased, a uniform surface layer cannot be formed, and the effect of preventing gas adhesion is reduced.
Further, the ion-exchange membranes described in patent documents 1 and 2 are still insufficient in resistance to impurities, and the stability of the ion-exchange membranes in electrolytic performance against impurities is still insufficient.
The present invention has been made in view of the above problems, and an object thereof is to provide an ion exchange membrane capable of reducing an electrolysis voltage by preventing adhesion of gas at the time of supplying to electrolysis and also capable of suppressing an influence of impurities in an electrolytic solution on electrolysis performance, a method for producing an ion exchange membrane, and an electrolytic cell.
Means for solving the problems
The present inventors have conducted extensive studies to solve the above problems, and as a result, have found that the effect of suppressing gas adhesion is exhibited by setting the coverage of the coating layer on the membrane body to a certain value or more, and the influence of impurities in the electrolytic solution on the electrolytic performance can be suppressed. As a result of further extensive and intensive studies based on the results, it was found that the above-mentioned coating rate can be obtained by reducing the viscosity of the coating liquid even when the binder ratio in the coating liquid at the time of forming the coating layer is increased, and the present invention was completed.
That is, the present invention includes the following aspects.
[1]
An ion exchange membrane having:
a membrane body comprising a fluorine-containing polymer having an ion exchange group; and
a coating layer disposed on at least one surface of the film main body,
wherein,
the coating layer contains inorganic particles and a binder,
the coating layer has a mass ratio of the binder to the total mass of the inorganic particles and the binder of 0.3 to 0.9,
the coating layer has a coating rate of 50% or more on the film body.
[2]
The ion-exchange membrane according to [1], wherein the inorganic particles are particles containing at least one inorganic substance selected from the group consisting of an oxide of a group IV element of the periodic Table, a nitride of a group IV element of the periodic Table, and a carbide of a group IV element of the periodic Table.
[3]
The ion-exchange membrane according to [1] or [2], wherein the inorganic particles are particles of zirconia.
[4]
The ion-exchange membrane according to any one of [1] to [3], wherein the binder contains a fluorine-containing polymer.
[5]
The ion-exchange membrane according to any one of [1] to [4], wherein the binder contains a fluorine-containing polymer having an ion-exchange group derived from a carboxyl group or a sulfo group.
[6]
A method for producing an ion-exchange membrane according to any one of [1] to [5], wherein,
the manufacturing method comprises the following steps: a coating layer is formed on the surface of the film body by spraying and drying a coating liquid containing inorganic particles, a binder and a solvent by a spray method,
the viscosity of the coating liquid is 13 mPas or less.
[7]
An electrolytic cell comprising the ion exchange membrane according to any one of [1] to [5 ].
ADVANTAGEOUS EFFECTS OF INVENTION
According to the present invention, it is possible to provide an ion exchange membrane which can reduce an electrolysis voltage at the time of supplying to electrolysis, has a small influence of impurities in an electrolytic solution on electrolysis performance, and can stably exert electrolysis performance, a method for producing the ion exchange membrane, and an electrolytic cell.
Drawings
Fig. 1 is a schematic sectional view showing one embodiment of an ion exchange membrane.
FIG. 2 is a schematic sectional view showing one embodiment of an electrolytic cell.
Description of the symbols
1 … ion exchange membrane, 2 … carboxylic acid layer, 3 … sulfonic acid layer, 4 … reinforcing material, 10 … membrane body, 11a,11b … coating layer, 100 … electrolytic cell, 200 … anode, 300 … cathode
Detailed Description
The following describes in detail a specific embodiment of the present invention (hereinafter, simply referred to as "the present embodiment"). The following embodiments are illustrative of the present invention, and are not intended to limit the present invention to the following. The present invention can be suitably modified and implemented within the scope of the gist thereof.
In the description of the drawings, the same or corresponding elements are denoted by the same reference numerals, and redundant description thereof is omitted. Unless otherwise specified, positional relationships such as vertical and horizontal in the drawings are based on the positional relationships shown in the drawings, and the dimensional ratios in the drawings are not limited to the illustrated ratios. However, the drawings merely show examples of the present embodiment, and the explanation of the present embodiment is not limited to these.
The ion exchange membrane of the present embodiment has: a membrane body comprising a fluorine-containing polymer having an ion exchange group, and a coating layer disposed on at least one surface of the membrane body, wherein the coating layer comprises inorganic particles and a binder, and the mass ratio of the binder in the coating layer is 0.3 to 0.9; the coating layer has a coating rate of 50% or more on the film body. With such a configuration, the ion exchange membrane of the present embodiment can reduce the electrolysis voltage when supplied to electrolysis, and has a small influence of impurities in the electrolyte solution on the electrolysis performance, thereby stably exhibiting the electrolysis performance. Therefore, the ion exchange membrane of the present embodiment and the electrolytic cell comprising the same can be preferably used for alkali metal chloride electrolysis (particularly, common salt electrolysis).
Fig. 1 is a schematic sectional view showing one embodiment of an ion exchange membrane. The ion exchange membrane 1 of the present embodiment has: a membrane main body 10 containing a fluorine-containing polymer having an ion exchange group; and coating layers 11a and 11b formed on both sides of the film body 10.
As illustrated in fig. 1, in the ion exchange membrane 1, the membrane main body 10 may include: having ion-exchange groups derived from sulfo groups (from-SO)3 -A sulfonic acid layer 3 of a group represented by (I), hereinafter also referred to as a "sulfonic acid group"), and an ion exchange group having a carboxyl group (represented by-CO)2 -The indicated groups, hereinafter also referred to as "carboxylic acid groups") of the carboxylic acid layer 2, further strength and dimensional stability can be enhanced by the reinforcing material 4. In the case where the ion-exchange membrane 1 includes the sulfonic acid layer 3 and the carboxylic acid layer 2, the ion-exchange membrane tends to exhibit more excellent performance.
The ion exchange membrane of the present embodiment is not limited to the configuration illustrated in fig. 1, and may have only one of the sulfonic acid layer and the carboxylic acid layer. The ion exchange membrane of the present embodiment is not necessarily reinforced with the reinforcing material, and the arrangement state of the reinforcing material is not limited to the example of fig. 1. The coating layer need not necessarily be disposed on both surfaces of the film body, and may be disposed on only one surface of the film body.
(film body)
First, the membrane main body 10 constituting the ion exchange membrane 1 of the present embodiment will be explained.
The membrane main body 10 is not particularly limited in its composition and material as long as it has a function of selectively transmitting cations and contains a fluorine-containing polymer having an ion exchange group, and various known fluorine-containing polymers can be appropriately selected and used.
The fluorine-containing polymer having an ion exchange group in the membrane main body 10 can be obtained, for example, from a fluorine-containing polymer having an ion exchange group precursor which can form an ion exchange group by hydrolysis or the like. Specifically, for example, a precursor of the membrane main body 10 may be prepared using a polymer whose main chain is composed of a fluorinated hydrocarbon, has a group that can be converted into an ion exchange group by hydrolysis or the like (ion exchange group precursor) as a pendant side chain, and is melt-processable (hereinafter, sometimes referred to as "fluorine-containing polymer (a)") and then the ion exchange group precursor is converted into an ion exchange group, thereby obtaining the membrane main body 10.
The fluorine-containing polymer (a) can be produced, for example, by copolymerizing at least one monomer selected from the following group 1 with at least one monomer selected from the following group 2 and/or the following group 3. The copolymer can also be produced by homopolymerization of 1 monomer selected from any one of the following groups 1, 2 and 3.
Examples of the monomer of group 1 include, but are not limited to, fluorinated vinyl compounds. Examples of the vinyl fluoride compound include, but are not limited to, vinyl fluoride, tetrafluoroethylene, hexafluoropropylene, vinylidene fluoride, trifluoroethylene, chlorotrifluoroethylene, perfluoro (alkyl vinyl ether), and the like. In particular, when the ion exchange membrane of the present embodiment is used for alkaline electrolysis, the vinyl fluoride compound is preferably a perfluoromonomer, preferably a perfluoromonomer selected from the group consisting of tetrafluoroethylene, hexafluoropropylene, and perfluoro (alkyl vinyl ether).
Examples of the monomer of group 2 include, but are not limited to, vinyl compounds having a functional group that can be converted into a carboxylic acid type ion exchange group (carboxylic acid group). Examples of the vinyl compound having a functional group convertible into a carboxylic acid group include, but are not limited to, compounds represented by the formula CF2＝CF(OCF2CYF)s-O(CZF)tA monomer represented by-COOR (where s is an integer of 0 to 2, t is an integer of 1 to 12, and Y and Z are each independently F or CF)3And R represents a lower alkyl group. The lower alkyl group is, for example, an alkyl group having 1 to 3 carbon atoms).
Among these, CF is preferred2＝CF(OCF2CYF)n-O(CF2)m-COOR. Wherein n represents an integer of 0 to 2, m represents an integer of 1 to 4, and Y represents F or CF3R represents CH3、C2H5Or C3H7。
When the ion-exchange membrane of the present embodiment is used as an ion-exchange membrane for alkali electrolysis, it is preferable to use at least a perfluoro compound as a monomer, but since the alkyl group of the ester group (see R above) is lost from the polymer at the time of hydrolysis, the alkyl group (R) may not be a perfluoroalkyl group in which all hydrogen atoms are substituted with fluorine atoms.
Among the above monomers, the monomers shown below are more preferable as the monomers of group 2.
CF2＝CFOCF2-CF(CF3)OCF2COOCH3、
CF2＝CFOCF2CF(CF3)O(CF2)2COOCH3、
CF2＝CF[OCF2-CF(CF3)]2O(CF2)2COOCH3、
CF2＝CFOCF2CF(CF3)O(CF2)3COOCH3、
CF2＝CFO(CF2)2COOCH3、
CF2＝CFO(CF2)3COOCH3。
Examples of the monomer of group 3 include vinyl compounds having a functional group that can be converted into a sulfone type ion exchange group (sulfonic acid group). As the vinyl compound having a functional group capable of being converted into a sulfonic acid group, for example, CF is preferable2＝CFO-X-CF2-SO2And F (wherein X represents a perfluoroalkylene group). Specific examples thereof include monomers shown below.
CF2＝CFOCF2CF2SO2F、
CF2＝CFOCF2CF(CF3)OCF2CF2SO2F、
CF2＝CFOCF2CF(CF3)OCF2CF2CF2SO2F、
CF2＝CF(CF2)2SO2F、
CF2＝CFO[CF2CF(CF3)O]2CF2CF2SO2F、
CF2＝CFOCF2CF(CF2OCF3)OCF2CF2SO2F。
Among these, CF is more preferable2＝CFOCF2CF(CF3)OCF2CF2CF2SO2F and CF2＝CFOCF2CF(CF3)OCF2CF2SO2F。
Copolymers obtained from these monomers can be produced by polymerization processes developed for the homopolymerization and copolymerization of fluorinated ethylene, in particular by the usual polymerization processes used for tetrafluoroethylene. For example, in the nonaqueous method, polymerization is carried out using an inert solvent such as perfluorocarbon or chlorofluorocarbon in the presence of a radical polymerization initiator such as perfluorocarbon peroxide or azo compound at a temperature of 0 to 200 ℃ and a pressure of 0.1 to 20 MPa.
In the copolymerization, the kind and the ratio of the combination of the monomers are not particularly limited, and may be selected and determined according to the kind and the amount of the functional group to be imparted to the resulting fluorine-containing polymer. For example, in the case of forming a fluorine-containing polymer containing only carboxylic acid groups, at least one monomer selected from the above-mentioned groups 1 and 2 may be copolymerized. In the case of forming a fluorine-containing polymer containing only sulfonic acid groups, at least one monomer selected from the above-mentioned group 1 and group 3 monomers may be copolymerized. In the case of forming a fluorine-containing polymer having a carboxylic acid group and a sulfonic acid group, at least one monomer selected from the group consisting of the group 1, the group 2 and the group 3 monomers may be copolymerized. In this case, the copolymer composed of the 1 st group and the 2 nd group and the copolymer composed of the 1 st group and the 3 rd group may be polymerized separately and then mixed to obtain the intended fluorine-containing polymer. The mixing ratio of the monomers is not particularly limited, and when the amount of the functional group per unit polymer is increased, the ratio of the monomers selected from the above-mentioned groups 2 and 3 may be increased.
The total ion exchange capacity of the fluorine-containing polymer is not particularly limited, but is preferably 0.5 to 2.0mg equivalent/g, more preferably 0.6 to 1.5mg equivalent/g. Here, the total ion exchange capacity is the equivalent of exchange groups per unit weight of the dried resin, and can be measured by neutralization titration or the like.
In a membrane body 10 of an ion exchange membrane 1 illustrated in fig. 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. In the case of forming the membrane main body 10 having such a layer structure, the permselectivity of cations such as sodium ions tends to be further improved.
When the ion exchange membrane 1 illustrated in fig. 1 is disposed in an electrolytic cell, it is generally disposed such that the sulfonic acid layer 3 is located on the anode side of the electrolytic cell and the carboxylic acid layer 2 is located on the cathode side of the electrolytic cell.
The sulfonic acid layer 3 is preferably made of a material having low electric resistance, and is preferably thicker than the carboxylic acid layer 2 in terms of film strength. The thickness of the sulfonic acid layer 3 is preferably 2 to 25 times, more preferably 3 to 15 times, that of the carboxylic acid layer 2.
The carboxylic acid layer 2 is preferably a material having anion-repelling property even if the film thickness is thin. The anion-repelling property as used herein means a property of inhibiting the invasion and permeation of anions into the ion-exchange membrane 1. In order to improve the anion-repelling property, it is effective to dispose a carboxylic acid layer having a small ion exchange capacity for the sulfonic acid layer.
As the fluorine-containing polymer used in the sulfonic acid layer 3, for example, CF is preferably used as the monomer of group 32＝CFOCF2CF(CF3)OCF2CF2SO2F, and a polymer obtained therefrom.
As the fluorine-containing polymer used in the carboxylic acid layer 2, for example, CF is preferably used as the monomer of the group 22＝CFOCF2CF(CF2)O(CF2)2COOCH3And the resulting polymer.
(coating layer)
The ion exchange membrane of the present embodiment has a coating layer disposed on at least one surface of a membrane main body. In the ion-exchange membrane 1 illustrated in fig. 1, the coating layers 11a and 11b are formed on both surfaces of the membrane main body 10.
The coating layer in the present embodiment includes inorganic particles and a binder, and the coating ratio of the coating layer to the film body is 50% or more. Here, the coverage is a value calculated by a measurement method described in an example described later. In the present embodiment, by making the coverage sufficiently large, adhesion of gas to the ion exchange membrane can be suppressed during electrolysis, and as a result, the electrolysis voltage can be sufficiently reduced. From the same viewpoint, the coverage is more preferably 60% or more, and still more preferably 65% or more. The coverage is preferably high, and from this viewpoint, the coverage may be set to 100%.
Specific measurement methods of the coverage are as follows.
The ion exchange membrane having the coating layer was observed from the side of the coating layer using a microscope (VHX-6000, magnification 500 times, manufactured by KEYENCE). Since the coated portion is observed to have high brightness due to scattering of light by the inorganic particles and the binder, the binarization process is performed with a region having a brightness of 150 or more of the observed image as the coated portion and a region having a brightness of less than 150 as the non-coated portion. The ratio of the covered portion when the entire observed image is 100 was calculated and used as the coverage.
The coverage is information on the coating layer obtained in the field of view (0.7 × 0.5mm) of the microscope. In contrast, the distribution density of the coating layer described later is information on the coating layer obtained in the measurement range (10 × 10mm) of the fluorescent X-ray. Thus, information of a region finer than the distribution density can be obtained by using the coverage.
The coating coverage of the coating layer in the present embodiment can be adjusted to the above range by, for example, sufficiently reducing the viscosity of the coating liquid when the coating liquid is sprayed by spraying, as described below, but is not limited thereto.
The average particle diameter of the inorganic particles in the present embodiment is not particularly limited, but is preferably 0.90 μm or more. When the average particle diameter of the inorganic particles is 0.90 μm or more, the durability against impurities tends to be further improved. In the present embodiment, it is preferable to use inorganic particles having an irregular shape, and it is more preferable to use inorganic particles obtained by grinding raw ores.
The inorganic particles may have an average particle diameter of 2 μm or less. When the average particle diameter of the inorganic particles is 2 μm or less, the film damage caused by the inorganic particles tends to be further prevented. The average particle diameter of the inorganic particles is more preferably 0.90 μm or more and 1.2 μm or less. More preferably 1 μm to 1.2 μm.
In the present specification, the average particle diameter refers to the median diameter (D50) and can be measured by a particle size distribution meter ("SALD 2200", shimadzu).
The inorganic particles in the present embodiment are preferably hydrophilic. Hydrophilicity means the property of a solid surface to be easily wetted by water. Generally, a substance having a small contact angle can be evaluated as hydrophilic, for example, an inorganic particle having a contact angle of about 90 ° can also be evaluated as hydrophilic, and the contact angle is preferably 90 ° or less, more preferably 40 ° or less. Here, the contact angle is an angle formed by a tangent line of a liquid surface at a point of contact between a solid and a liquid and the solid surface, and can be calculated by bringing a liquid droplet into contact with the solid surface and analyzing an image at the time of dropping by using a contact angle meter ("DMo-601", manufactured by syngamy interface chemistry). When the inorganic particles are hydrophilic, the inorganic particles tend to be oriented on the surface of the coating layer, thereby further suppressing adhesion of gas to the ion exchange membrane during electrolysis. More preferably, at least one inorganic substance selected from the group consisting of an oxide of a group IV element of the periodic table, a nitride of a group IV element of the periodic table, and a carbide of a group IV element of the periodic table is contained. Specific examples thereof include, but are not limited to, zirconia, silica, tin oxide, titanium oxide, nickel oxide, SiC, ZrC, and the like. Particles of zirconia are more preferable from the viewpoint of durability.
The inorganic particles in the present embodiment are preferably inorganic particles produced by pulverizing raw ores of the inorganic particles. Further, the inorganic particles may be produced by melting and refining a raw ore of the inorganic particles, and spherical particles having a uniform particle diameter may be used as the inorganic particles in the coating layer.
The pulverization method is not particularly limited, and examples thereof include a ball mill, a bead mill, a colloid mill, a conical ball mill, a disc mill, an edge mill, a pulverizer, a hammer mill, a granulator, a VSI mill, a vilier mill, a roll mill, and a jet mill. Further, it is preferable to wash after pulverization, and as a washing method in this case, acid treatment is preferable. This can reduce impurities such as iron adhering to the surface of the inorganic particles.
In the present embodiment, the coating layer contains a binder. The binder is a component for forming a coating layer by holding inorganic particles on the surface of the ion exchange membrane. The binder preferably contains a fluorine-containing polymer in view of resistance against the electrolyte solution or the product generated by electrolysis. The binder may be the same kind of fluorine-containing polymer as the fluorine-containing polymer constituting the film main body, or may be a different kind of fluorine-containing polymer. In addition to such a fluorine-containing polymer, various known compounds as a binder component in the coating layer may be used, and the content of the fluorine-containing polymer in the binder is preferably 90% by mass or more.
The binder in the present embodiment is more preferably a fluorine-containing polymer having a carboxylic acid group or a sulfonic acid group, from the viewpoint of resistance against an electrolytic solution or a product generated by electrolysis and adhesion to the surface of the ion exchange membrane. When a coating layer is provided on a layer (sulfonic acid layer) containing a fluorine-containing polymer having a sulfonic acid group, the fluorine-containing polymer having a sulfonic acid group is more preferably used as a binder for the coating layer. When a coating layer is provided on a layer (carboxylic acid layer) containing a fluorine-containing polymer having a carboxylic acid group, the fluorine-containing polymer having a carboxylic acid group is more preferably used as a binder for the coating layer.
In the present embodiment, the mass ratio of the binder to the total mass of the inorganic particles and the binder in the coating layer is 0.3 to 0.9. The present inventors have found that the ion transmission resistance of the ion exchange membrane itself can be reduced by increasing the mass ratio of the binder in the coating layer. That is, the mass ratio of the binder is 0.3 or more, whereby the ion transmission resistance of the ion-exchange membrane itself can be further reduced, and therefore, the electrolytic voltage can be greatly reduced by interacting with the case where the coverage of the coating layer is increased as described above. In addition, by setting the mass ratio of the binder to 0.9 or less, the effect of preventing gas adhesion can be obtained by the inorganic particles, and thus the electrolytic voltage can be reduced. From the same viewpoint, the mass ratio of the binder is preferably 0.32 to 0.9, more preferably 0.35 to 0.9, and still more preferably 0.4 to 0.9.
There is no particular limitation on the distribution density of the coating layer in the ion exchange membraneDefined, preferably per 1cm2Is 0.05mg to 2mg, more preferably per 1cm2Is 0.5mg to 2 mg. The distribution density can be measured by the method described in the examples below. The distribution density can be adjusted to the above range by, for example, changing the amount of spray during spraying or changing the number of times of repeated application.
(reinforcing Material)
The ion exchange membrane of the present embodiment preferably has a reinforcing material disposed inside the membrane main body.
In the present embodiment, the reinforcing material functions as at least one of the reinforcing thread and the sacrificial thread, and examples thereof include, but are not limited to, woven fabrics obtained by weaving the reinforcing thread and the sacrificial thread. By disposing the reinforcing material inside the membrane main body, the expansion and contraction of the ion exchange membrane can be controlled particularly within a desired range. The ion exchange membrane does not expand or contract more than necessary during electrolysis or the like, and can maintain excellent dimensional stability for a long period of time.
The structure of the reinforcing material is not particularly limited, and may be formed by spinning a yarn called a reinforcing yarn, for example. The reinforcing thread as referred to herein is a member constituting a reinforcing material, and means a thread which can impart desired dimensional stability and mechanical strength to the ion-exchange membrane and can stably exist in the ion-exchange membrane. By using a reinforcing material obtained by spinning the reinforcing yarn, more excellent dimensional stability and mechanical strength can be imparted to the ion-exchange membrane.
The reinforcing material and the reinforcing wire used for the reinforcing material are not particularly limited, but a material having resistance to acids, alkalis, and the like is preferable, and fibers made of a fluorine-containing polymer are preferable in terms of imparting long-term heat resistance and chemical resistance.
The fluoropolymer used for the film body can be used as the fluoropolymer used for the reinforcing material in the same manner, and specific examples thereof include Polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-ethylene copolymer (ETFE), tetrafluoroethylene-hexafluoropropylene copolymer, chlorotrifluoroethylene-ethylene copolymer, and vinylidene fluoride Polymer (PVDF). Among these, fibers made of polytetrafluoroethylene are particularly preferably used from the viewpoint of heat resistance and chemical resistance.
The diameter of the reinforcing yarn used in the reinforcing material is not particularly limited, but is preferably 20 to 300 deniers, and more preferably 50 to 250 deniers. The weaving density (the number of beating-up threads per unit length) is preferably 5 to 50 threads/inch. The form of the reinforcing material is not particularly limited, and for example, woven fabric, nonwoven fabric, knitted fabric, and the like are used, and the form of woven fabric is preferable. The woven fabric is preferably 30 to 250 μm, more preferably 30 to 150 μm, thick.
The woven fabric or knitted fabric may be formed of monofilament, multifilament, or yarns thereof, or slit yarn, and various weaving methods such as plain weaving, leno weaving, knitting, pin-hole weaving, and crepe-like weaving may be used.
The weave and arrangement of the reinforcing material in the membrane main body are not particularly limited, and may be suitably arranged in consideration of the size and shape of the ion exchange membrane, the desired physical properties of the ion exchange membrane, the use environment, and the like.
For example, the reinforcing material may be disposed along a predetermined one direction of the film main body, and from the viewpoint of dimensional stability, it is preferable to dispose the reinforcing material along a predetermined first direction and dispose the other reinforcing material along a second direction substantially perpendicular to the first direction. By arranging a plurality of reinforcing members in a substantially straight line inside the longitudinal film main body of the film main body, more excellent dimensional stability and mechanical strength can be imparted in multiple directions. For example, an arrangement in which a reinforcing material (warp) arranged in the longitudinal direction and a reinforcing material (weft) arranged in the transverse direction are woven into the surface of the film main body is preferable. From the viewpoint of dimensional stability, mechanical strength, and ease of manufacture, a plain weave in which the warp and weft are alternately raised and lowered and beaten up, a leno weave in which 2 warps are twisted and woven with the weft, a square plain weave in which the same number of wefts are beaten up in 2 or more warps arranged in parallel, and the like are more preferable.
In particular, it is preferable to arrange the reinforcing material in both the MD Direction (Machine Direction) and the TD Direction (Transverse Direction) of the ion exchange membrane. That is, it is preferably flat woven in the MD direction and the TD direction. Here, the MD direction refers to the transport direction (flow direction) of the membrane main body and the reinforcement material in the ion exchange membrane production process described later, and the TD direction refers to a direction substantially perpendicular to the MD direction. The yarn woven in the MD direction is referred to as MD yarn, and the yarn woven in the TD direction is referred to as TD yarn. Generally, it is more the case that: the ion exchange membrane used in the electrolysis is rectangular, with the length direction being the MD direction and the width direction being the TD direction. By weaving a reinforcing material as MD yarns and a reinforcing material as TD yarns, more excellent dimensional stability and mechanical strength can be imparted in multiple directions.
The interval between the reinforcing materials is not particularly limited, and the reinforcing materials can be suitably arranged in consideration of the desired physical properties of the ion exchange membrane, the use environment, and the like.
Among the reinforcing materials, a flat yarn or a highly oriented monofilament comprising PTFE is particularly preferable from the viewpoint of chemical resistance and heat resistance. Specifically, the following reinforcing materials are more preferable: a high-strength porous sheet made of PTFE is cut into a tape-like flat yarn or a flat woven fabric of 50 to 300 deniers of highly oriented monofilaments made of PTFE and having a weaving density of 10 to 50 yarns/inch, and the thickness of the flat woven fabric is 50 to 100 [ mu ] m. More preferably, the ion exchange membrane containing the reinforcing material has an opening ratio of 60% or more.
Examples of the shape of the reinforcing wire include a round wire and a strip wire. A round wire is preferred.
(communicating hole)
The ion exchange membrane of the present embodiment preferably has communication holes in the membrane main body.
The communicating holes are holes that can serve as flow paths for cations or electrolytes generated during electrolysis. The communication hole is a tubular hole formed inside the film body, and is formed by elution of a reinforcing material (sacrificial thread) described later. The shape, the pore diameter, and the like of the communicating pores can be controlled by selecting the shape and the wire diameter of the reinforcing material (sacrificial wire).
By forming the communicating holes in the ion exchange membrane, the mobility of the alkali ions and the electrolytic solution generated during electrolysis can be ensured. The shape of the through-holes is not particularly limited, and can be a shape of a reinforcing material (sacrificial line) used for forming the through-holes by a manufacturing method described later.
In the present embodiment, the communication hole is preferably formed so as to alternately pass through the anode side (sulfonic acid layer side) and the cathode side (carboxylic acid layer side) of the reinforcing material. With this configuration, the portion where the through-holes are formed on the cathode side of the reinforcing material allows cations (for example, sodium ions) transported by the electrolyte filled in the through-holes to flow to the cathode side of the reinforcing material. As a result, the flow of the cations is not interrupted, and therefore the electric resistance of the ion exchange membrane can be further reduced.
The communication holes may be formed only in a predetermined one direction of the membrane main body constituting the ion exchange membrane of the present embodiment, but are preferably formed in both the longitudinal direction and the transverse direction of the membrane main body from the viewpoint of exerting more stable electrolysis performance.
[ production method ]
The method for producing the ion-exchange membrane of the present embodiment is not particularly limited as long as the ion-exchange membrane having the above-described configuration can be obtained, and the ion-exchange membrane is preferably produced by a method including the following steps (1) to (6).
(1) The process comprises the following steps: 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.
(2) The process comprises the following steps: and if necessary, weaving at least a plurality of reinforcing threads and a sacrificial thread having a property of dissolving in an acid or an alkali for forming a communication hole, thereby obtaining a reinforcing material in which the sacrificial thread is arranged between adjacent reinforcing threads.
(3) The process comprises the following steps: and forming a film from the fluorine-containing polymer having an ion exchange group or an ion exchange group precursor capable of forming an ion exchange group by hydrolysis.
(4) The process comprises the following steps: and a step of embedding the reinforcing material in the film as necessary to obtain a film body in which the reinforcing material is arranged.
(5) The process comprises the following steps: and (4) hydrolyzing the film body obtained in step (4) (hydrolysis step).
(6) The process comprises the following steps: and (5) a step (coating step) of providing a coating layer on the film body obtained in the step (5).
The method for producing an ion exchange membrane of the present embodiment is mainly characterized in that the viscosity of the coating liquid is adjusted in the coating step (6). The respective steps will be described in detail below.
(1) The process comprises the following steps: process for producing fluorine-containing polymer
In the step (1), the fluorine-containing polymer is produced using the raw material monomers described in the above groups 1 to 3. In order to control the ion exchange capacity of the fluorine-containing polymer, the mixing ratio of the raw material monomers may be adjusted in the production of the fluorine-containing polymer forming each layer.
(2) The process comprises the following steps: process for producing reinforcing material
The reinforcing material is woven fabric woven from reinforcing threads. By embedding the reinforcing material in the film, a film body containing the reinforcing material can be obtained.
(3) The process comprises the following steps: film formation step
In the step (3), the fluoropolymer obtained in the step (1) is formed into a film by using an extruder. The film may have a single-layer structure, may have a two-layer structure of the sulfonic acid layer and the carboxylic acid layer as described above, or may have a multilayer structure of 3 or more layers.
(4) The process comprises the following steps: process for obtaining film body
In the step (4), the reinforcing material obtained in the step (2) is embedded in the film obtained in the step (3), thereby obtaining a film body containing the reinforcing material.
Preferred methods for forming the film body include the following: (i) a method in which a fluorine-containing polymer having a carboxylic acid group precursor (for example, a carboxylic acid ester group) on the cathode side (hereinafter, a layer composed of the polymer is referred to as a first layer) and a fluorine-containing polymer having a sulfonic acid group precursor (for example, a sulfonyl fluoride group) (hereinafter, a layer composed of the polymer is referred to as a second layer) are formed into a film by a coextrusion method, a reinforcing material and a second layer/first layer composite film are laminated in this order on a plate or a cylinder having a large number of pores on the surface thereof via a heat-resistant release paper having air permeability by using a heat source and a vacuum source as necessary, and the layers are integrated by removing air between the layers by pressure reduction at a temperature at which the polymers are melted; (ii) a method in which a fluorine-containing polymer having a sulfonic acid group precursor (third layer) is separately formed into a film separately from the second layer/first layer composite film, and if necessary, a third layer film, a reinforcing material, and a composite film composed of the second layer/first layer are laminated in this order on a flat plate or a cylinder having a large number of fine pores on the surface thereof via a heat-resistant release paper having air permeability, using a heat source and a vacuum source, and the layers are integrated by removing air from the layers at a temperature at which the polymers are melted and under reduced pressure.
Here, co-extrusion of the first layer and the second layer is preferable because it contributes to improvement of the adhesive strength at the interface.
In addition, the method of integration under reduced pressure is preferable because the thickness of the third layer on the reinforcing material tends to be larger than the method of pressure pressing, and the reinforcing material tends to be fixed to the inner surface of the membrane body, thereby sufficiently maintaining the mechanical strength of the ion exchange membrane.
The lamination pattern described here is an example, and an appropriate lamination pattern (for example, a combination of layers or the like) may be appropriately selected in consideration of a desired layer structure of the film body, physical properties, and the like, and then co-extruded.
For the purpose of further improving the electrical performance of the ion exchange membrane, a fourth layer made of a fluorine-containing polymer having both a carboxylic acid group precursor and a sulfonic acid group precursor may be interposed between the first layer and the second layer, or a fourth layer made of a fluorine-containing polymer having both a carboxylic acid group precursor and a sulfonic acid group precursor may be used instead of the second layer.
The fourth layer may be formed by separately producing a fluorine-containing polymer having a carboxylic acid group precursor and a fluorine-containing polymer having a sulfonic acid group precursor and mixing them, or by using a copolymer obtained by copolymerizing a monomer having a carboxylic acid group precursor and a monomer having a sulfonic acid group precursor.
In the case of the ion exchange membrane having the fourth layer, a coextruded film of the first layer and the fourth layer may be formed, the third layer and the second layer may be separately laminated, or the third layer and the second layer may be laminated by the above-mentioned method, or the first layer, the fourth layer, and the second layer may be formed by coextrusion of 3 layers at a time.
In this case, the flow direction of the film subjected to extrusion is the MD direction. In this way, a membrane main body including a fluorine-containing polymer having an ion exchange group can be formed on the reinforcing material.
The ion exchange membrane of the present embodiment preferably has a projection, i.e., a convex portion, on the surface side of the sulfonic acid layer, the projection being made of a fluorine-containing polymer having a sulfonic acid group. The method for forming such a projection is not particularly limited, and a known method for forming a projection on a resin surface can be employed. Specifically, for example, a method of embossing the surface of the film body may be mentioned. For example, when the composite film is integrated with a reinforcing material or the like, the convex portion may be formed by using a release paper which is embossed in advance. In the case where the convex portions are formed by embossing, the height and arrangement density of the convex portions can be controlled by controlling the transferred embossed shape (the shape of the release paper).
(5) Hydrolysis step
In the step (5), the membrane main body obtained in the step (4) is hydrolyzed to convert the ion exchange group precursor into an ion exchange group (hydrolysis step).
In the step (5), the sacrificial lines included in the film body are dissolved and removed with an acid or an alkali, whereby the dissolution holes can be formed in the film body. The sacrificial line may not be completely dissolved and removed but may remain in the via hole. The sacrificial thread remaining in the communicating hole may be dissolved and removed by the electrolyte solution when the ion exchange membrane is subjected to electrolysis.
The sacrificial thread has solubility to acid or alkali in the production process of the ion exchange membrane or in the electrolytic environment, and the sacrificial thread is eluted to form a communicating hole in the portion.
(6) Coating step
In the step (6), a coating layer is formed on the surface of the film body by spraying and drying a coating liquid containing inorganic particles, a binder and a solvent by a spray method.
In the present embodiment, by sufficiently reducing the viscosity of the coating liquid, the coating liquid is easily wet-spread on the surface of the film body when the coating liquid is sprayed, and the formed coating layer is uniformly formed on the surface of the film body. As described above, by sufficiently reducing the viscosity of the coating liquid, the coverage of the coating layer can be sufficiently increased even when a coating liquid having a high binder ratio is used.
As the inorganic particles, particles obtained by pulverizing raw ore can be preferably used, and as the binder, the following binders can be preferably used: hydrolyzing a fluorine-containing polymer having an ion exchange group precursor with an aqueous solution containing dimethyl sulfoxide (DMSO) and potassium hydroxide (KOH), immersing the hydrolyzed polymer in hydrochloric acid, and replacing the counter ion of the ion exchange group with H+The binder thus obtained (for example, a fluorine-containing polymer having a carboxyl group or a sulfo group) is used. This binder is preferably easily dissolved in water and ethanol described later.
The binder is preferably dissolved in a solution obtained by mixing water and ethanol, for example. The volume ratio of water to ethanol is preferably 10:1 to 1:1, more preferably 5:1 to 1:5, and still more preferably 2:1 to 1: 2.
The inorganic particles are dispersed in the thus-obtained solution by a ball mill to obtain a coating liquid. In this case, the average particle diameter of the inorganic particles and the viscosity of the coating liquid can be adjusted by adjusting the time and the rotation speed during dispersion.
The preferable amount of the inorganic particles and the binder to be mixed is 0.3 to 0.9 in terms of the binder ratio with respect to the total mass of the inorganic particles and the binder in the coating liquid, from the viewpoint of further reducing the ion transmission resistance of the ion-exchange membrane itself. The mass ratio of the binder in the coating liquid in the above charge ratio is equal to the ratio of the binder after formation of the coating layer, and therefore the ratio of the binder in the coating layer in the ion exchange membrane can be determined in accordance with the charge ratio.
In addition, a surfactant may be added to the dispersion liquid when the inorganic particles are dispersed. As the surfactant, nonionic surfactants are preferred, and examples thereof include, but are not limited to, HS-210, NS-210, P-210, E-212 and the like manufactured by Nichisu oil Co.
The viscosity of the coating liquid thus obtained is preferably 13mPa · s or less, more preferably 11mPa · s or less. When the viscosity is low, the film surface is uniformly wet and spread, and the effect of preventing gas adhesion can be sufficiently exhibited.
The viscosity can be controlled by a known method. Examples thereof include changing various conditions for dissolving the binder polymer, changing various conditions for dispersing the inorganic particles, and adding the surfactant and the viscosity modifier. The viscosity of the coating liquid can be measured by the method described in examples.
The ion exchange membrane of the present embodiment is obtained by applying the obtained coating liquid to at least one surface of the membrane main body by spray coating to form a coating layer.
As described above, the method for producing an ion exchange membrane according to the present embodiment preferably includes a step of forming a coating layer on the surface of the membrane body by spraying a coating solution containing inorganic particles, a binder and a solvent by a spraying method and drying the coating solution, wherein the viscosity of the coating solution is 13mPa · s or less.
[ electrolytic tank ]
The ion exchange membrane of the present embodiment can be used as a component of an electrolytic cell. That is, the electrolytic cell of the present embodiment includes the ion exchange membrane of the present embodiment. FIG. 2 is a schematic view of an embodiment of the electrolytic cell of the present embodiment.
The electrolytic cell 100 of the present embodiment includes at least an anode 200, a cathode 300, and the ion exchange membrane 1 of the present embodiment disposed between the anode 200 and the cathode 300. Here, the electrolytic cell 100 including the ion exchange membrane 1 described above is described as an example, but the present invention is not limited thereto, and various modifications of the structure can be made within the scope of the effects of the present embodiment.
The electrolytic cell 100 can be used for various types of electrolysis, and a case of being used for electrolysis of an aqueous solution of an alkali chloride will be described below as a representative example.
The electrolysis conditions are not particularly limited, and can be carried out under known conditions. For example, 2.5 to 5.5 equivalents (N) of an alkali metal chloride aqueous solution is supplied to the anode chamber, water or a diluted alkali metal hydroxide aqueous solution is supplied to the cathode chamber, and electrolysis is performed by direct current.
The structure of the electrolytic cell of the present embodiment is not particularly limited, and may be, for example, a monopolar type or a bipolar type. The material constituting the electrolytic cell 100 is not particularly limited, and for example, titanium or the like having resistance to alkali metal chloride and chlorine is preferable as the material of the anode chamber, and nickel or the like having resistance to alkali metal hydroxide and hydrogen is preferable as the material of the cathode chamber. The electrodes may be disposed with an appropriate space between the ion exchange membrane 1 and the anode 200, but the anode 200 may be used without any problem even if it is disposed in contact with the ion exchange membrane 1. The cathode is usually disposed at an appropriate distance from the ion exchange membrane, but even a contact-type electrolytic cell (zero-pole-pitch electrolytic cell) having no such distance can be used without any problem.
Examples
The present embodiment will be described in more detail below based on examples. The present embodiment is not limited to these examples.
(measurement of viscosity)
The viscosity of the coating solution was measured at 25 ℃ and 10rpm using an E-type viscometer (TV-35L, manufactured by Toyobo industries, Ltd., standard conical rotor).
(coverage rate)
The ion-exchange membrane was observed from the side of the coating layer using a microscope (VHX-6000, 500 Xmagnification, manufactured by KEYENCE). Since the coated portion is observed to have high brightness due to scattering of light by the inorganic particles and the binder, the binarization process is performed with a region having a brightness of 150 or more of the observed image as the coated portion and a region having a brightness of less than 150 as the non-coated portion. The ratio of the covered portion when the entire observed image is 100 was calculated and used as the coverage.
(distribution Density of coating layer)
The distribution density was calculated by quantifying the amount of zirconium present in the dried coating layer using a fluorescent X-ray analyzer (X-MET8000, manufactured by horiba ltd., ltd.) and converting the amount into the total weight of the coating layer containing the binder using a calibration curve prepared in advance. In the preparation of the calibration curve, a sample whose distribution density is already known by weight measurement is used, and a calibration curve is prepared for each coating liquid having a different binder ratio.
[ electrolytic evaluation ]
As an electrolytic cell used for electrolysis, an electrolytic cell having a structure in which an ion exchange membrane is disposed between an anode and a cathode and in which 4 natural circulation type zero-pitch electrolytic cells are connected in series is used.
As the cathode, a woven mesh of a fine nickel wire having a diameter of 0.15mm woven with a mesh of 50 mesh coated with cerium oxide or ruthenium oxide as a catalyst was used. In order to bring the cathode into close contact with the ion exchange membrane, a pad formed of a fine nickel wire is disposed between a current collector formed of a metal expanded metal made of nickel and the cathode. As the anode, a titanium expanded metal coated with ruthenium oxide, iridium oxide, and titanium oxide as a catalyst was used.
The brine was supplied to the anode side while adjusting the concentration to 205g/L, and the water was supplied while maintaining the sodium hydroxide concentration at the cathode side at 32 mass%. The temperature of the electrolytic cell was set to 85 ℃ at 6kA/m2The current density of (3) is determined by carrying out electrolysis under the condition that the liquid pressure on the cathode side of the electrolytic cell is higher than the liquid pressure on the anode side by 5.3 kPa. The inter-pair voltage between the anode and cathode of the electrolytic cell was measured every day by a voltmeter TR-V1000 manufactured by KEYENCE corporation, and the average value of 7 days was determined as the electrolytic voltage.
[ test for tolerance to impurities ]
Using the above electricityThe electrolytic cell was supplied with brine while adjusting the concentration to 205g/L on the anode side, and supplied with water while maintaining the sodium hydroxide concentration on the cathode side at 32 mass%. And using a brine containing 10ppm of I and 0.03ppm of Ba as impurities, the temperature of the electrolytic cell was set to 85 ℃ at 6kA/m2The current density of (3) was determined by carrying out electrolysis for 9 days under the condition that the liquid pressure on the cathode side of the electrolytic cell was higher than the liquid pressure on the anode side by 5.3 kPa. Then, increase and decrease in the value of the current efficiency on the 9 th day after electrolysis compared with the value of the current efficiency on the 1 st day after electrolysis were measured, and the rate of change in 1 day unit was obtained as the impurity resistance.
This test is an accelerated test in which an excessive amount of impurities greater than the impurity concentration allowable under the normal electrolysis conditions are added, and if the decrease in current efficiency in this test is 0.75%/day or less, it is evaluated that the decrease in current efficiency due to the influence of impurities is not caused under the normal electrolysis conditions. In addition, if the decrease in current efficiency in this test is 0.55%/day or less, it is evaluated that the decrease in current efficiency due to the influence of a temporary increase in impurity concentration (which is caused by a failure of the brine purification system or the like) can be suppressed.
[ example 1]
As the reinforcing yarn, a linear material (hereinafter, referred to as PTFE yarn) obtained by twisting a flat filament of 100 denier made of Polytetrafluoroethylene (PTFE) 900 times/m was used. As the sacrificial thread for the warp thread, a thread obtained by twisting 35 denier, 8-filament polyethylene terephthalate (PET) at 200 times/m (hereinafter referred to as PET thread) was used. As the sacrificial thread as the weft, a 35-denier, 8-filament polyethylene terephthalate (PET) thread twisted 200 times/m (hereinafter, referred to as a PET thread in the case of fiber) was used. First, 24 PTFE threads/inch and 2 sacrificial threads were arranged between adjacent PTFE threads, and a woven fabric having a thickness of 100 μm was obtained.
Next, it is prepared as CF2＝CF2And CF2＝CFOCF2CF(CF3)OCF2CF2COOCH3The copolymer (A1) has an ion exchange capacity of 0.85mg equivalent/g, and is a polymer of a dry resin2＝CF2And CF2＝CFOCF2CF(CF3)OCF2CF2SO2The copolymer of F had an ion exchange capacity of 1.03mg equivalent/g of the polymer of dry resin (B1). Using these polymers (A1) and (B1), a two-layer film X having a polymer (A1) layer thickness of 20 μm and a polymer (B1) layer thickness of 94 μm was obtained by a coextrusion T-die method. The ion exchange capacity of each polymer indicates the ion exchange capacity after the ion exchange group precursor of each polymer is hydrolyzed and converted into an ion exchange group.
Obtained as CF2＝CF2And CF2＝CFO-CF2CF(CF3)O-(CF2)2-SO2The copolymer of F had an ion exchange capacity of 1.05m equivalents/g of polymer. This was extruded through a monolayer T die to give a monolayer film Y having a thickness of 20 μm.
Next, a release paper, a film Y, a reinforcing material (the woven fabric obtained above), and a film X, which were previously subjected to embossing, were sequentially laminated on a cylinder having a heat source and a vacuum source inside and having fine holes on the surface thereof, and the composite film having an uneven shape was obtained by heating and reducing pressure for 2 minutes under conditions of a cylinder temperature of 240 ℃ and a vacuum degree of 0.067MPa, and then removing the release paper. The obtained composite membrane was soaked in an aqueous solution containing 30 mass% of dimethyl sulfoxide (DMSO) and 15 mass% of potassium hydroxide (KOH) at 90 ℃ for 1 hour to saponify the composite membrane, then soaked in 0.5N NaOH at 90 ℃ for 1 hour to replace the ions carried by the ion exchange groups with Na, and then washed with water. Further dried at 60 ℃ to obtain a film body.
In addition, will be as CF2＝CF2And CF2＝CFOCF2CF(CF3)OCF2CF2SO2The polymer (B3) of the dried resin having an ion exchange capacity of the copolymer of F of 1.05mg equivalent/g was hydrolyzed and then converted into an acid form with hydrochloric acid. The acid-form polymer (B3) was dissolved in a mixed solution of water and ethanol (50/50 mass ratio) at a ratio of 5 mass%, and zirconia particles having a primary particle diameter of 1.15 μm were added to the resulting solution so that the mass of the polymer (B3) was equal to the total mass of the polymer (B3) and the zirconia particlesThe ratio was 0.4. Thereafter, the resultant was dispersed by a ball mill until the average particle diameter of the zirconia particles in the suspension became 0.94. mu.m, to obtain a coating liquid. HS-210 manufactured by Nichikoku Kogyo was added as a nonionic surfactant to the obtained coating solution, and the viscosity of the coating solution was adjusted to 9.3 mPas. The viscosity of the coating liquid was measured by the above method, and the raw ore crushed material was used as the zirconia.
This suspension was applied to both surfaces of the membrane main body by a spraying method, and dried, thereby obtaining an ion exchange membrane having a coating layer containing the polymer (B3) and the zirconia particles.
The distribution density measured by the above method was 1cm per unit20.5 mg. The coating ratio measured by the above method was 83.3%.
After wetting the ion-exchange membrane by an increase of 2 mass%, the electrolytic performance was evaluated by using the ion-exchange membrane, and as a result, the voltage was low at 3.07V, and as a result, the decrease in current efficiency was small, 0.51%/day, and high impurity durability was exhibited, when the impurity resistance was measured.
[ example 2]
An ion exchange membrane was produced in the same manner as in example 1, except that the amount of HS-210 used was reduced and the viscosity was changed to 12.0 mPas in example 1. In the ion exchange membrane, the content of the fluorine-containing polymer in the binder is 100 mass%.
The distribution density was measured in the same manner as in example 1, and the result was 1cm per unit20.5 mg. The coating rate was measured in the same manner as in example 1, and the result was 56.5%.
[ electrolytic evaluation ]
Using this ion exchange membrane, evaluation of electrolytic performance was performed under the same conditions as in example 1, and as a result, the voltage was low, i.e., 3.08V, and as a result, when the impurity resistance was measured, the decrease in current efficiency was small, i.e., 0.74%/day, and high impurity durability was exhibited.
[ example 3]
An ion exchange membrane was produced in the same manner as in example 1, except that the amount of HS-210 used in example 1 was increased to change the viscosity to 8.5 mPas. In the ion exchange membrane, the content of the fluorine-containing polymer in the binder is 100 mass%.
The distribution density was measured in the same manner as in example 1, and the result was 1cm per unit20.5 mg. The coating rate was measured in the same manner as in example 1, and the result was 92.9%.
[ electrolytic evaluation ]
Using this ion exchange membrane, evaluation of electrolytic performance was carried out under the same conditions as in example 1, and as a result, the voltage was low, i.e., 3.06V, and as a result, when the impurity resistance was measured, the decrease in current efficiency was small, i.e., 0.42%/day, and high impurity durability was exhibited.
[ example 4]
An ion exchange membrane was produced in the same manner as in example 1, except that in example 1, a suspension was used in which the mass ratio of the polymer (B3) to the total mass of the polymer (B3) and the zirconia particles was 0.7. In this case, the amount of HS-210 used was the same as in example 1, and the viscosity of the coating liquid was 11.0 mPas. In the ion exchange membrane, the content of the fluorine-containing polymer in the binder is 100 mass%.
The distribution density was measured in the same manner as in example 1, and the result was 1cm per unit20.5 mg. The coating rate was measured in the same manner as in example 1, and the result was 66.8%.
[ electrolytic evaluation ]
Using this ion exchange membrane, evaluation of electrolytic performance was carried out under the same conditions as in example 1, and as a result, the voltage was low, i.e., 3.06V, and as a result, when the impurity resistance was measured, the decrease in current efficiency was small, i.e., 0.27%/day, and high impurity durability was exhibited.
[ example 5]
An ion exchange membrane was produced in the same manner as in example 1, except that a suspension having a polymer (B3) mass ratio of 0.32 to the total mass of the polymer (B3) and the zirconia particles was used in example 1. In this case, the amount of HS-210 used was the same as in example 1, and the viscosity of the coating liquid was 8.6 mPas. In the ion exchange membrane, the content of the fluorine-containing polymer in the binder is 100 mass%.
The distribution density was measured in the same manner as in example 1, and the result was expressed as1cm20.5 mg. The coating rate was measured in the same manner as in example 1, and the result was 90.1%.
[ electrolytic evaluation ]
Using this ion exchange membrane, evaluation of electrolytic performance was performed under the same conditions as in example 1, and as a result, the voltage was low, i.e., 3.08V, and as a result, when the impurity resistance was measured, the decrease in current efficiency was small, i.e., 0.61%/day, and high impurity durability was exhibited.
Comparative example 1
An ion exchange membrane was produced in the same manner as in example 1, except that in example 1, a suspension was used in which the mass ratio of the polymer (B3) to the total mass of the polymer (B3) and the zirconia particles was 0.2. In this case, the amount of HS-210 used was the same as in example 1, and the viscosity of the coating liquid was 8.6 mPas. In the ion exchange membrane, the content of the fluorine-containing polymer in the binder is 100 mass%.
The distribution density was measured in the same manner as in example 1, and the result was 1cm per unit20.5 mg. The coating rate was measured in the same manner as in example 1, and the result was 98.1%.
[ electrolytic evaluation ]
Using this ion exchange membrane, evaluation of electrolytic performance was carried out under the same conditions as in example 1, and as a result, the voltage showed a high value of 3.13V, and as a result, when the impurity resistance was measured, the current efficiency was greatly reduced to 1.01%/day, which was strongly influenced by impurities.
Comparative example 2
An ion exchange membrane was produced in the same manner as in example 1, except that a suspension having a polymer (B3) mass ratio of 0.2 relative to the total mass of the polymer (B3) and the zirconia particles was used in example 1, and viscosity adjustment was not performed using HS-210. In this case, the coating liquid had a viscosity of 9.0 mPas, and the content of the fluoropolymer in the binder in the ion-exchange membrane was 100% by mass.
The distribution density was measured in the same manner as in example 1, and the result was 1cm per unit20.5 mg. The coating rate was measured in the same manner as in example 1, and the result was 97.7%.
[ electrolytic evaluation ]
Using this ion exchange membrane, evaluation of electrolytic performance was carried out under the same conditions as in example 1, and as a result, the voltage showed a high value of 3.14V, and as a result, when the impurity resistance was measured, the current efficiency was greatly reduced to 1.02%/day, which was strongly influenced by impurities.
Comparative example 3
An ion exchange membrane was produced in the same manner as in example 1, except that the viscosity was not adjusted by HS-210 in example 1. In this case, the coating liquid had a viscosity of 14.0 mPas, and the content of the fluoropolymer in the binder in the ion-exchange membrane was 100% by mass.
The distribution density was measured in the same manner as in example 1, and the result was 1cm per unit20.5 mg. The coating rate was measured in the same manner as in example 1, and the result was 40.0%.
[ electrolytic evaluation ]
Using this ion exchange membrane, evaluation of electrolytic performance was carried out under the same conditions as in example 1, and as a result, the voltage showed a high value of 3.12V, and as a result, when the impurity resistance was measured, the current efficiency was greatly reduced to 0.91%/day, which was strongly influenced by impurities.
Comparative example 4
An ion exchange membrane was produced in the same manner as in example 1, except that a suspension having a polymer (B3) mass ratio of 0.6 relative to the total mass of the polymer (B3) and the zirconia particles was used in example 1, and the viscosity was not adjusted by HS-210. In this case, the coating liquid had a viscosity of 22.0 mPas, and the content of the fluoropolymer in the binder in the ion-exchange membrane was 100% by mass.
The distribution density was measured in the same manner as in example 1, and the result was 1cm per unit20.5 mg. The coating rate was measured in the same manner as in example 1, and the result was 30.0%.
[ electrolytic evaluation ]
Using this ion exchange membrane, evaluation of electrolytic performance was carried out under the same conditions as in example 1, and as a result, the voltage showed a high value of 3.11V, and as a result, when the impurity resistance was measured, the current efficiency was greatly reduced to 0.82%/day, and the influence of impurities was strongly exerted.
The results are summarized in table 1 below.
[ Table 1]
Claims (7)
1. An ion exchange membrane having:
a membrane body comprising a fluorine-containing polymer having an ion exchange group; and
a coating layer disposed on at least one surface of the film main body,
wherein,
the coating layer comprises inorganic particles and a binder,
in the coating layer, the mass ratio of the binder to the total mass of the inorganic particles and the binder is 0.3 to 0.9,
the coating layer has a coating rate of 50% or more on the film body.
2. The ion-exchange membrane according to claim 1, wherein the inorganic particles are particles containing at least one inorganic substance selected from the group consisting of an oxide of a group IV element of the periodic table, a nitride of a group IV element of the periodic table, and a carbide of a group IV element of the periodic table.
3. The ion-exchange membrane according to claim 1 or 2, wherein the inorganic particles are particles of zirconia.
4. The ion-exchange membrane according to any one of claims 1 to 3, wherein the binder comprises a fluorine-containing polymer.
5. The ion-exchange membrane according to any one of claims 1 to 4, wherein the binder comprises a fluorine-containing polymer having an ion-exchange group derived from a carboxyl group or a sulfo group.
6. A method for producing an ion exchange membrane according to any one of claims 1 to 5, wherein,
the manufacturing method comprises the following steps: a coating layer is formed on the surface of the film body by spraying and drying a coating liquid containing inorganic particles, a binder and a solvent by a spray method,
the viscosity of the coating liquid is 13 mPas or less.
7. An electrolytic cell comprising the ion exchange membrane according to any one of claims 1 to 5.
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| CN103668319A (en) * | 2012-09-14 | 2014-03-26 | 旭化成化学株式会社 | Ion exchange membrane, manufacturing method of ion exchange membrane, and electrolytic cell |
| US20160279627A1 (en) * | 2013-12-25 | 2016-09-29 | Asahi Glass Company, Limited | Production method for fluorinated cation exchange membrane |
| CN107916435A (en) * | 2016-10-06 | 2018-04-17 | 旭化成株式会社 | Cation-exchange membrane and electrolytic cell |
| CN107949664A (en) * | 2015-09-08 | 2018-04-20 | 旭硝子株式会社 | The manufacture method of ion-exchange membrane for alkali chloride electrolysis and the manufacture method of alkali chloride electrolysis device |
| CN108026651A (en) * | 2015-09-08 | 2018-05-11 | 旭硝子株式会社 | The manufacture method of ion-exchange membrane for alkali chloride electrolysis and the manufacture method of alkali chloride electrolysis device |
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| US20060205301A1 (en) * | 2005-03-11 | 2006-09-14 | Bha Technologies, Inc. | Composite membrane having hydrophilic properties and method of manufacture |
| JP6411631B2 (en) * | 2015-03-18 | 2018-10-24 | 旭化成株式会社 | Diaphragm for alkaline water electrolysis, alkaline water electrolysis apparatus, method for producing hydrogen, and method for producing diaphragm for alkaline water electrolysis |
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| CN103668319A (en) * | 2012-09-14 | 2014-03-26 | 旭化成化学株式会社 | Ion exchange membrane, manufacturing method of ion exchange membrane, and electrolytic cell |
| US20160279627A1 (en) * | 2013-12-25 | 2016-09-29 | Asahi Glass Company, Limited | Production method for fluorinated cation exchange membrane |
| CN107949664A (en) * | 2015-09-08 | 2018-04-20 | 旭硝子株式会社 | The manufacture method of ion-exchange membrane for alkali chloride electrolysis and the manufacture method of alkali chloride electrolysis device |
| CN108026651A (en) * | 2015-09-08 | 2018-05-11 | 旭硝子株式会社 | The manufacture method of ion-exchange membrane for alkali chloride electrolysis and the manufacture method of alkali chloride electrolysis device |
| CN107916435A (en) * | 2016-10-06 | 2018-04-17 | 旭化成株式会社 | Cation-exchange membrane and electrolytic cell |
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