Alkaline water electrolysis membrane

Abstract

The aim of the present invention is to provide an alkaline water electrolysis membrane having good gas barrier property, which can maintain hydrophilicity during operation in long-term electrolysis, inhibit the reduction in ion permeability caused by bubble attachment, and improve the hydrogen production efficiency during the long-term operation of an alkaline electrolytic cell. The alkaline water electrolysis membrane is an electrolysis membrane capable of inhibiting the reduction of hydrophilicity thereof during long-term use and achieving a high production yield of hydrogen. The electrolysis membrane comprises: a porous support, and a porous resin containing a surfactant.

Description

Alkaline water electrolysis separator TECHNICAL FIELD

[0001] The present invention relates to an alkaline water electrolysis separator, and belongs to the field of alkaline water electrolysis. BACKGROUND

[0002] Alkaline electrolysis has the advantage of low cost and is suitable for large-scale applications, and is therefore widely used in industrial hydrogen production. An alkaline water electrolysis device generally has one or more electrolytic cells, which are separated into an anode chamber and a cathode chamber by an alkaline water electrolysis separator. When a direct current is applied between the two electrodes, oxygen is generated in the anode chamber and hydrogen is generated in the cathode chamber. In the case of electrolysis of water, sodium hydroxide or potassium hydroxide is usually added to the water as an electrolyte to improve the conductivity of the electrolyte.

[0003] For an alkaline water electrolysis separator, it is required to have gas barrier properties that prevent oxygen and hydrogen from mixing. In addition, since ions carry electrons in the electrolyte of alkaline water electrolysis, the separator is also required to have high ion permeability in order to improve the efficiency of electrolysis. When the alkaline water electrolysis separator is installed in the electrolytic cell, it is required to have alkali resistance to the alkaline electrolyte, heat resistance during electrolysis, and mechanical strength requirements such as not to cause damage to the separator. Patent Document 1 (CN116601334A) discloses a substrate for an alkaline water electrolysis separator, which is formed by using a non-woven fabric containing polyphenylene sulfide fibers having a special cross-section, thereby having high mechanical strength and other properties.

[0004] Furthermore, in order to maintain ion permeability during electrolysis, the surface of the alkaline water electrolysis separator is required to have hydrophilicity. Therefore, so far, a technology has been known for adding hydrophilic inorganic particles to the alkaline water electrolysis separator to impart hydrophilicity. Patent Document 2 (Japanese Patent No. 5981751) discloses an alkaline water electrolysis separator in which a fine pore membrane is laminated on one or both sides of a porous support, and by tilting the pore diameter of the fine pore membrane in the thickness direction, high gas barrier properties are maintained and the ion permeability is also high. Patent Document 3 (Japanese Patent No. 7365748) discloses a method for manufacturing an alkaline water electrolysis separator, which coats a resin containing inorganic particles onto a substrate to suppress the detachment of the inorganic particles, and a surfactant is added to increase the dispersibility of the inorganic particles. Patent Document 4 (CN107250437A) discloses a separator for alkaline water electrolysis, which has a high molecular porous membrane containing a high molecular resin and hydrophilic inorganic particles, and by controlling the ratio of the average pore diameter of the surface of the high molecular porous membrane to the mode particle diameter of the hydrophilic inorganic particles within a certain range, the detachment of the hydrophilic inorganic particles is suppressed.

[0005] However, although the existing alkaline water electrolysis separators can suppress the detachment of the hydrophilic inorganic particles to some extent, they are not sufficient to maintain the hydrophilicity and ion permeability for a long time, and thus it is difficult to achieve an improvement in the hydrogen production efficiency for a long time. SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] The present inventors found that the existing alkaline water electrolysis separators still cause the detachment of the hydrophilic inorganic particles from the separators during the operation under the electrolysis state for a long time, the hydrophilicity of the separators decreases, and thus the ion permeability decreases due to the attachment of bubbles to the separators, and the hydrogen production efficiency with respect to the input power decreases.

[0008] The present invention was completed in view of the problems in the above-described prior art, and an object of the present invention is to provide an alkaline water electrolysis separator that has a good gas barrier property, can maintain the hydrophilicity during the operation under the electrolysis state for a long time, suppresses the decrease in the ion permeability of an alkaline electrolyzer due to the operation for a long time, and improves the hydrogen production efficiency of the alkaline electrolyzer during the operation for a long time.

[0009] MEANS FOR SOLVING THE PROBLEMS

[0010] The present inventors repeatedly conducted intensive research in order to solve the above-described problems, and as a result, found that the above-described problems can be solved by using a porous support and a porous resin containing a surfactant to constitute an alkaline water electrolysis separator. In addition, the present inventors found that the above-described problems can be solved by using at least any one selected from the group consisting of a spunlace nonwoven fabric and a papermaking in an alkaline water electrolysis separator containing a porous resin and a porous support. Thus, the present invention was completed.

[0011] Specifically, the present invention solves the above-described problems by the following technical solutions.

[0012] [1] An alkaline water electrolysis separator comprising: a porous support, and a porous resin containing a surfactant.

[0013] [2] The alkaline water electrolysis separator according to item [1], wherein the content of the surfactant is 1 to 40 wt% with respect to the total solid content of the porous resin.

[0014] [3] The alkaline water electrolysis separator according to item [1] or [2], wherein the porous support comprises at least any one selected from the group consisting of a woven fabric, a knitted fabric, a nonwoven fabric, and a papermaking.

[0015] [4] The alkaline water electrolysis separator according to any one of items [1] to [3], wherein the porous support comprises at least any one selected from the group consisting of a spunlace nonwoven fabric and a papermaking.

[0016] [5] The alkaline water electrolysis separator according to any one of [1] to [4], wherein the porous support is composed of polyphenylene sulfide fibers as a main component.

[0017] [6] The alkaline water electrolysis separator according to any one of [1] to [5], wherein the porous resin is at least any one selected from the group consisting of polyphenylene sulfide, polyphenylsulfone, polysulfone, and polyethersulfone.

[0018] [7] The alkaline water electrolysis separator according to any one of [1] to [6], wherein the electric conduction resistance satisfies: the voltage at 60 A / dm2is 1.90 V or less. 2

[0019] [8] The alkaline water electrolysis separator according to any one of [1] to [7], wherein the hydrophilic speed when immersed in an aqueous solution having a pH of 13 at 130°C for 1000 hours is 40.0% or more relative to the initial value.

[0020] [9] The alkaline water electrolysis separator according to any one of [1] to [6], wherein the electric conduction resistance satisfies: the voltage at 50 A / dm2is 40 V or less, and the hydrophilic speed when immersed in an aqueous solution having a pH of 13 at 85°C for 1000 hours is 90.0% or more relative to the initial value.

[0021] The alkaline water electrolysis separator according to the present application is composed of a porous support and a porous resin containing a surfactant as a hydrophilic agent, and not only has good gas barrier properties, but also can inhibit the detachment of the surfactant as a hydrophilic agent from the alkaline water electrolysis separator for a long time, thereby maintaining the hydrophilicity in the operation under the electrolysis state for a long time, inhibiting the decrease in ion permeability due to the attachment of bubbles, and thus improving the hydrogen production efficiency in the long-term operation of the alkaline electrolyzer. DETAILED DESCRIPTION

[0022] Various exemplary embodiments, features, and aspects of the present application will be described in detail below. The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any implementation described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other implementations.

[0023] In addition, in order to better illustrate the present application, numerous specific details are given in the following detailed description. It will be understood by those skilled in the art that the present application can be practiced without certain specific details, which are provided for a more thorough understanding of the present application. In other instances, methods, apparatuses, and steps well known to those skilled in the art have not been described in detail in order to avoid obscuring the present application.

[0024] ​The units used in the present specification are international standard units unless otherwise specified, and the numerical values, numerical ranges appearing in the present application should be understood to include systematic errors that are unavoidable in industrial production.

[0025] In the present specification, the meaning indicated by "may" includes both the meaning of performing a certain process and the meaning of not performing the certain process.

[0026] In the present specification, "some specific / preferred embodiments", "other specific / preferred embodiments", "embodiments", and the like refer to specific elements (for example, features, structures, properties, and / or characteristics) described in relation to the embodiments, and can or can not be present in other embodiments. In addition, it should be understood that the elements can be combined in various embodiments in any suitable manner.

[0027] In the present specification, the numerical range indicated by "numerical value A to numerical value B" refers to a range including the end point values A, B.

[0028] In the present specification, "wt%" means "weight percent", that is, weight percentage.

[0029] In the present specification, "normal temperature and pressure" generally refers to a temperature of 20 to 30°C and a pressure of about 1 atmosphere, and typically refers to a temperature of about 25°C and a pressure of about 1.01325 Pa.

[0030] In the present specification, the temperature used when measuring the electrically conductive resistance, the surface hydrophilization speed, the gas barrier property, and the 1000-hour hydrogen production amount refers to the set temperature, and there can be an error of ±5°C between the actual temperature and the set temperature. For example, in the case of temperature X°C, the set temperature is X°C, and the actual temperature is allowed to be in the range of X-5°C or more and X+5°C or less. Therefore, the technical meaning of temperature X°C should be understood to include the range of X-5°C or more and X+5°C or less for the actual temperature.

[0031] [First Embodiment]

[0032] The first embodiment of the present application relates to an alkaline water electrolysis separator comprising: a porous support, and a porous resin containing a surfactant.

[0033] [porous support]

[0034] In the present embodiment, the alkaline water electrolysis separator comprises a porous support. The porous support is not particularly limited as long as it is porous, has ion permeability, and can be a member that can be a support for an alkaline water electrolysis separator. A porous support that is generally used as a support for an alkaline water electrolysis separator can be used.

[0035] In the present embodiment, the porous support can be formed of a resin. As the resin forming the porous support, for example, polyphenylene sulfide, polysulfone, polyethersulfone, polyphenylsulfone, polyether ether ketone, polyvinylidene fluoride, polycarbonate, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene-ethylene copolymer, polyvinylidene fluoride, polytetrafluoroethylene, perfluorosulfonic acid, perfluorocarboxylic acid, polyethylene, polypropylene, poly-p-phenylene benzobisoxazole, polyketone, polyimide, polyetherimide, and the like can be given, but are not limited thereto. Among these, from the viewpoint of being able to exhibit excellent gas barrier properties and ion permeability, and heat resistance and alkali resistance, polyphenylene sulfide, polyphenylsulfone, polysulfone, polyethersulfone are preferable, and polyphenylene sulfide is more preferable. One of them can be used alone, or two or more of them can be used in combination.

[0036] As the polyphenylene sulfide (PPS) resin, for example, "Torelina (registered trademark)" manufactured by Toray Industries, Inc., "DURAFIDE (registered trademark)" manufactured by Polyplastics Co., Ltd., "Ryton (registered trademark)" manufactured by Solvay, and the like can be given, but are not limited thereto. As the polysulfone, for example, "Ultrason S PSU (trademark)" of BASF, "Udel (trademark)" of Solvay Advanced Polymers, and the like can be given, but are not limited thereto. As the polyethersulfone, for example, "Ultrason E PES (trademark)" of BASF, "Veradel (trademark)", "Radel A (trademark)" of Solvay Advanced Polymers, and the like can be given, but are not limited thereto. As the polyphenylsulfone, for example, "Ultrason P PPSU (trademark)" of BASF, "Radel R (trademark)" of Solvay Advanced Polymers, and the like can be given, but are not limited thereto. As the polyether ether ketone (PEEK) resin, for example, "TORAYTPS (registered trademark) PEEK" manufactured by Toray Industries, Inc., "VESTAKEEP" manufactured by DuPont-Teijin Limited, "PEEK polymer" manufactured by Victrex, and the like can be given.

[0037] As the porous support, for example, woven fabric, knitted fabric, nonwoven fabric, papermaking, and the like can be given, but are not limited thereto. One of them can be used alone, or two or more of them can be used in combination. The porous support can be a single layer, or a laminate of multiple layers. In the case where the porous support is a laminate of multiple layers, each layer can be the same or different.

[0038] As the nonwoven fabric that can be used as the porous support, there are, for example, nonwoven fabrics formed by a wet method, a dry method, melt-blown nonwoven fabrics, spunlace nonwoven fabrics, hot-melt adhesive nonwoven fabrics, needle punch nonwoven fabrics, air-laid nonwoven fabrics, and the like. In the present embodiment, from the viewpoint of achieving high ion permeability and low electric resistance, and further from the viewpoint of being able to ensure the uniformity of the surface of the support, the porous support preferably contains a spunlace nonwoven fabric, a papermaking paper. Note that the "papermaking paper" refers to a paper produced by a method including a papermaking step, and typically can be a paper produced by a wet papermaking method.

[0039] In the present embodiment, the porous support can be composed of a resin fiber formed of the above-mentioned resin. From the viewpoint of further being able to have excellent alkali resistance and moisture heat resistance, the porous support is preferably composed of polyphenylene sulfide fibers as a main component, and further preferably the porous support is a spunlace nonwoven fabric or a papermaking paper composed of polyphenylene sulfide fibers as a main component. Note that the "main component" refers to a component having a content of 30% by weight or more, preferably 40% by weight or more, further preferably 50% by weight or more, and can be 60% by weight or more, 70% by weight or more, 80% by weight or more, or 90% by weight or more, and the upper limit of the content of the component is 100% by weight. Therefore, "polyphenylene sulfide fibers as a main component" means that the content of polyphenylene sulfide fibers is 30% by weight or more, preferably 40% by weight or more, further preferably 50% by weight or more, and can be 60% by weight or more, 70% by weight or more, 80% by weight or more, or 90% by weight or more, based on the total weight of the porous support.

[0040] The above-mentioned polyphenylene sulfide fibers refer to synthetic fibers composed of a polymer (PPS polymer) having "-(C6H4-S)-" as a main structural unit as a polymer constituent unit. Note that the "main structural unit" refers to a structural unit having a content of 30% by weight or more, preferably 40% by weight or more, further preferably 50% by weight or more, and can be 60% by weight or more, 70% by weight or more, 80% by weight or more, or 90% by weight or more, with respect to the total content of the structural units of the polymer, and the upper limit of the content of the main structural unit is 100% by weight.

[0041] As the polymer that constitutes the porous support, for example, polyphenylene sulfide, polyphenylsulfone, and the like are exemplified. In addition, random copolymers, block copolymers, and the like of these polymers can also be exemplified. Further, mixtures of the aforementioned polymers can be exemplified. As a particularly preferred polymer, polyphenylene sulfide can be exemplified, and further, a PPS polymer containing preferably 90% by weight or more of a para-phenylene unit represented by -(C6H4-S)- as a main structural unit of the polymer as a whole can be exemplified.

[0042] The fiber length of the aforementioned resin fiber that can be used to form the porous support of the present application is not particularly limited, and from the viewpoint of easily manufacturing the porous support, it is preferably from 0.1 mm to 100 mm, more preferably from 0.5 mm to 80 mm, and particularly preferably from 1 mm to 65 mm.

[0043] The weight per unit area of the porous support of the present application is not particularly limited, and it is preferably from 15 g / m 2 to 170 g / m 2 , more preferably from 25 g / m 2 to 140 g / m 2 , and particularly preferably from 35 g / m 2 to 90 g / m 2 . In the case where the weight per unit area is too small, there is a case where the mechanical strength of the alkaline water electrolysis separator becomes low, and in the case where the weight per unit area is too large, there is a case where the electric conduction resistance becomes high and it is difficult to improve the hydrogen production efficiency with respect to the input power.

[0044] The thickness of the porous support of the present application is not particularly limited, and it is preferably from 30 μm to 300 μm, more preferably from 40 μm to 250 μm, and particularly preferably from 60 μm to 180 μm. In the case where the thickness is too small, there is a case where the mechanical strength of the alkaline water electrolysis separator becomes low, and in the case where the thickness is too large, there is a case where the electric conduction resistance becomes high and it is difficult to improve the hydrogen production efficiency with respect to the input power.

[0045] [porous resin]

[0046] In the present embodiment, the alkaline water electrolysis separator contains a porous resin. The resin that constitutes the porous resin is not particularly limited, and examples thereof include: sulfone-based resins such as polysulfone, polyethersulfone, and polyphenylsulfone; fluorine-based resins such as polyvinylidene fluoride and polytetrafluoroethylene; vinyl-based resins such as polyethylene, polypropylene, and polystyrene; sulfide-based resins such as polyphenylene sulfide; poly(p-phenylene benzobisoxazole); ketone-based resins such as polyketone; imide-based resins such as polyimide and polyetherimide; ester-based resins such as polycarbonate; and the like. These resins can be used alone or in combination with two or more kinds thereof. Among these, from the viewpoint of having excellent gas barrier properties and ion permeability, polysulfone, polyethersulfone, polyphenylsulfone, and polyphenylene sulfide are preferable, and polysulfone, polyethersulfone, and polyphenylsulfone are further preferable. They can be used alone or in combination with two or more kinds thereof.

[0047] Note that the resin that constitutes the porous resin can be the same kind as the resin that forms the porous support, or can be a different kind. From the viewpoints of having excellent gas barrier properties and ion permeability and maintaining ion permeability over a long period of time, it is preferable that the resin that constitutes the porous resin is preferably polysulfone, polyethersulfone, or polyphenylsulfone, and the resin that forms the porous support is preferably polyphenylene sulfide.

[0048] The thickness of the separator formed of the porous support and the porous resin is not particularly limited, and is preferably 30 μm to 600 μm, more preferably 50 μm to 500 μm, and particularly preferably 70 μm to 400 μm, from the viewpoint of excellent gas barrier properties and ion permeability.

[0049] In addition, the size of the pores of the porous resin is not particularly limited, and is preferably 0.010 μm to 5 μm, more preferably 0.015 μm to 3 μm, and particularly preferably 0.020 μm to 2 μm, as the number average diameter, from the viewpoint of excellent gas barrier properties and ion permeability.

[0050] The method for producing the porous resin is not particularly limited, and examples include a nonsolvent-induced phase separation method, a thermal-induced phase separation method, a water vapor-induced phase separation method, a solvent evaporation method, and the like. From the viewpoint of workability, a production method having at least the following steps is preferably used: a step of dissolving or dispersing a resin constituting the porous resin in an organic solvent to prepare a coating liquid containing the resin, coating the coating liquid on the aforementioned porous support and allowing it to infiltrate, or immersing the porous support in the coating liquid and taking it out; and a step of removing the aforementioned organic solvent.

[0051] From the viewpoint of obtaining and maintaining high ion permeability, a production method having at least the following steps is further preferably used: a step of dissolving a resin constituting the porous resin and, as necessary, an organic compound that can affect ion permeability in an organic solvent to prepare a coating liquid, coating the coating liquid on the aforementioned porous support and allowing it to infiltrate, or immersing the porous support in the coating liquid and taking it out, and causing the resin to precipitate (phase separation) using a poor solvent for the resin; and a step of dissolving and removing the aforementioned organic compound and / or the aforementioned organic solvent, and washing, using water or the like as the poor solvent for the resin.

[0052] As the aforementioned organic solvent, an organic solvent capable of dissolving the aforementioned resin constituting the porous resin is meant. Specifically, for example, N-methyl-2-pyrrolidone; N,N-dimethylacetamide; N,N-dimethylformamide; dimethyl sulfoxide; tetrahydrofuran; an alkyldiol-based solvent such as (di- or tri-)propylene glycol monoalkyl ether, (di- or tri-)propylene glycol monoalkyl ether acetate; a carbonate-based solvent such as ethylene carbonate, propylene carbonate; and the like can be used. These organic solvents can be used alone or in combination with two or more.

[0053] As the organic compound which can affect the formation of pores in the porous layer, for example, polyethylene glycol, polyethylene oxide, polypropylene glycol, ethylene glycol, tripropylene glycol, glycerol, a polyhydric alcohol, dibutyl phthalate, diethyl phthalate, diundecyl phthalate, isononyl or neodecanoic acid, polyvinylpyrrolidone, polyvinyl alcohol, polyvinyl acetate, polyvinyl imine, polyacrylic acid, methyl cellulose, and dextran can be exemplified. From the viewpoint of obtaining and maintaining high ion permeability, the above organic compound is preferably selected from polyethylene glycol, polyethylene oxide, and polyvinylpyrrolidone.

[0054] As the poor solvent for the above resin, a solvent which does not dissolve the above resin constituting the porous resin, but causes phase separation, precipitation, and dissolution of the above organic compound can be suitably used. Specifically, for example, water, methanol, ethanol, propanol, isopropanol, butanol, ethylene glycol, propylene glycol, and the like can be exemplified. These solvents can be used alone or two or more kinds can be used in combination.

[0055] [Surfactant]

[0056] In the first embodiment of the present application, the above porous resin contains a surfactant as a hydrophilic agent. The kind of the surfactant contained in the porous resin is not particularly limited, and any compound having both a hydrophilic group and a lipophilic group in the molecule can be used.

[0057] The surfactant can be classified into anionic, cationic, and amphoteric ionic surfactants and nonionic surfactants.

[0058] As the anionic surfactant, for example, there are carboxylic acid type, sulfonic acid type, sulfate type, and phosphate type. As the carboxylic acid type anionic surfactant, for example, there are aliphatic monocarboxylate, polyoxyethylene alkyl ether carboxylate, N-acyl sarcosinate, and N-acyl glutamate. As the sulfonic acid type anionic surfactant, for example, there are dialkyl sulfosuccinate, alkane sulfonate, a-olefin sulfonate, linear alkylbenzene sulfonate, alkyl (branched) benzene sulfonate, naphthalene sulfonate-formaldehyde condensate, alkyl naphthalene sulfonate, and N-methyl-N-acyl taurate. As the sulfate type anionic surfactant, for example, there are alkyl sulfate, polyoxyethylene alkyl ether sulfate, and oil and fat sulfate. As the phosphate type anionic surfactant, for example, there are alkyl phosphate type, polyoxyethylene alkyl ether phosphate, and polyoxyethylene alkyl phenyl ether phosphate. From the viewpoint of easy availability, preferable examples include higher alcohol sulfate salts such as sodium lauryl sulfate, ammonium lauryl sulfate, sodium dodecyl sulfate, ammonium dodecyl sulfate, sodium octyl sulfate, sodium decyl sulfate, sodium tetradecyl sulfate, sodium hexadecyl sulfate, and sodium octadecyl sulfate; alkyl benzene sulfonate salts such as sodium dodecyl benzene sulfonate, sodium lauryl benzene sulfonate, and sodium hexadecyl benzene sulfonate; and aliphatic sulfonate salts such as sodium lauryl sulfonate, sodium dodecyl sulfonate, and sodium tetradecyl sulfonate.

[0059] As the cationic surfactant, for example, there are alkyl amine salt type and quaternary ammonium salt type. As the alkyl amine salt type cationic surfactant, for example, there are monoalkyl amine salt, dialkyl amine salt, and trialkyl amine salt. As the quaternary ammonium salt type cationic surfactant, for example, there are halogenated (chlorinated, brominated, or iodinated) alkyl trimethyl ammonium salt and chlorinated alkyl benzalkonium chloride.

[0060] As the amphoteric surfactant, for example, there are carboxybetaine type, 2-alkylimidazoline derivative type, glycine type, and amine oxide type. As the carboxybetaine type amphoteric surfactant, for example, there are alkyl betaine and fatty acid amide propyl betaine. As the 2-alkylimidazoline derivative type amphoteric surfactant, for example, there is 2-alkyl-N-carboxymethyl-N-hydroxyethyl imidazolinium betaine. As the glycine type amphoteric surfactant, for example, there is alkyl or dialkyl diethylene triamino acetic acid. As the amine oxide type amphoteric surfactant, for example, there is alkyl amine oxide.

[0061] As the nonionic surfactant, for example, there are ester type, ether type, ester ether type, and alkanolamide type. As the nonionic surfactant of the ester type, for example, there are glycerin fatty acid ester, sorbitol fatty acid ester, and sucrose fatty acid ester. As the nonionic surfactant of the ether type, for example, there are polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, and polyoxyethylene polyoxypropylene glycol. As the nonionic surfactant of the ester ether type, for example, there are fatty acid polyethylene glycol and fatty acid polyoxyethylene sorbitol. As the nonionic surfactant of the alkanolamide type, for example, there are fatty acid alkanolamides.

[0062] The content of the surfactant in the aforementioned porous resin is not particularly limited, and from the viewpoint of excellent gas barrier property and ion permeability, and long-term maintenance of hydrophilicity and ion permeability, it is preferable to contain 1 to 40% by weight of the surfactant, more preferable to contain 8 to 38% by weight of the surfactant, further preferable to contain 15 to 35% by weight of the surfactant, and particularly preferable to contain 18 to 30% by weight of the surfactant, with respect to the total solid content contained in the aforementioned porous resin. If the content of the surfactant is less than 1% by weight with respect to the total solid content contained in the aforementioned porous resin, there is a tendency that the hydrophilicity is insufficient, and it is difficult to maintain the ion permeability for a long time. If the content of the surfactant exceeds 40% by weight with respect to the total solid content contained in the aforementioned porous resin, there is a tendency that the mechanical strength, heat resistance, and alkali resistance of the alkaline water electrolysis separator are insufficient.

[0063] Note that the content of the surfactant in the aforementioned porous resin is equivalent to the amount of the surfactant added to the composition for producing the porous resin. That is, it is preferable to contain 1 to 40% by weight of the surfactant, more preferable to contain 8 to 38% by weight of the surfactant, further preferable to contain 15 to 35% by weight of the surfactant, and particularly preferable to contain 18 to 30% by weight of the surfactant, with respect to the total solid content of the composition for producing the porous resin.

[0064] The content of the surfactant in the porous resin can be calculated as follows: the total weight of the solid raw materials used in the composition for producing the porous resin is measured, the amount of the surfactant added to the composition for producing the porous resin is calculated by dividing the weight of the surfactant by the aforementioned total weight, and the content of the surfactant in the porous resin is calculated.

[0065] In the first embodiment, the porous resin of the alkaline water electrolysis separator according to the present application can contain, in addition to the aforementioned surfactant, other hydrophilic agents as needed. As the other hydrophilic agents, hydrophilic inorganic particles such as metal oxides, metal inorganic acid salts, metal hydroxides, and the like can be exemplified. Preferred metal oxides can be exemplified by zirconium oxide, titanium oxide, bismuth oxide, cerium oxide, and magnesium oxide. Preferred metal inorganic acid salts can be exemplified by barium sulfate, zirconium phosphate. Preferred metal hydroxides can be exemplified by zirconium hydroxide, titanium hydroxide, bismuth hydroxide, cerium hydroxide, and magnesium hydroxide.

[0066] The hydrophilic inorganic particles preferably have a D50 particle size of 0.05 to 2.0 μm, more preferably 0.1 to 1.5 μm, further preferably 0.15 to 1.00 μm, particularly preferably 0.2 to 0.75 μm. The D50 particle size is preferably 0.7 μm or less, preferably 0.55 μm or less, more preferably 0.40 μm or less.

[0067] The method for producing the porous resin containing the surfactant and the other hydrophilic agents added as needed is not particularly limited, and the same method as the aforementioned method for producing the porous resin except that the coating liquid further contains the surfactant and the other hydrophilic agents added as needed can be exemplified.

[0068] The aforementioned surfactant is preferably an anionic surfactant, and more preferably a sulfonic acid type from the viewpoint of affinity with the porous resin. The mixing of the surfactant with the porous resin can be performed by a conventional mixing method, and for example, can be melt mixing or mixing the surfactant in the porous resin dissolved in a good solvent. The porous resin containing the surfactant thus obtained is imparted to the porous support, and the method can be coating the porous resin on the porous support or immersing the porous support in a mixture in which the porous resin is dissolved in a good solvent. Among these, in order to allow the porous resin to penetrate into the porous support, the immersion method is preferred.

[0069] [Alkaline water electrolysis separator]

[0070] The alkaline water electrolysis separator according to the present application has the aforementioned porous resin and the porous support. In the alkaline water electrolysis separator according to the present application, the aforementioned porous resin and the porous support can be laminated one each, or a plurality of each. Although not particularly limited, from the viewpoint of maintaining the strength of the alkaline water electrolysis separator or preventing peeling, and the like, the alkaline water electrolysis separator is preferably integrated with at least a part of the porous resin impregnated inside the porous support.

[0071] The electric conductive resistance of the alkaline water electrolysis separator according to the present application can be measured at a current density of 60 A / dm 2voltage at a current density of 60 A / dm 2 The voltage at a current density of 60 A / dm 2 The voltage at a current density of 60 A / dm

[0072] The conductive resistance represented by the voltage at a current density of 60 A / dm 2 The method for measuring the conductive resistance represented by the voltage at a current density of 60 A / dm 2 is not particularly limited, and for example, it can be measured as follows: an alkaline water electrolysis separator is installed in an electrolysis device, in which an electrolyte solution of 25% by mass of potassium hydroxide aqueous solution is used, the liquid temperature is set to 80°C, a pure nickel mesh is used for the anode, nickel cobalt oxide is used as a catalyst, a platinum mesh electrode for hydrogen generation is used for the cathode, and the electrolysis area of the electrolysis unit is set to 1 dm 2 The voltage required for flowing a unit current of 60 A / dm 2 to the electrolysis unit from the electrolysis device is measured, and the voltage at 60 A / dm 2 is taken as an index representing the magnitude of the conductive resistance. The greater the voltage at 60 A / dm 2 , the greater the conductive resistance is represented. The voltage at a current density of 60 A / dm 2 at 80°C can also be referred to as the voltage at 60 A / dm 2 .

[0073] In addition, the conductive resistance of the alkaline water electrolysis separator of the present application can also be represented by the voltage at a current density of 50 A / dm 2 . From the aspect of improving the hydrogen production efficiency with respect to the input power, the voltage at 50 A / dm 2 is preferably 40 V or less, further preferably 35 V or less, and more preferably 30 V or less. From the viewpoint of ease of manufacture and cost, the voltage at 50 A / dm 2 may be 1 V or more.

[0074] The method for measuring the conductive resistance represented by the voltage at a current density of 50 A / dm 2 is not particularly limited, and for example, it can be measured as follows: an alkaline water electrolysis separator is installed in an electrolysis device, in which an electrolyte solution of 30% by mass of potassium hydroxide aqueous solution is used, the liquid temperature is set to 85°C, a pure nickel mesh is used for the anode, nickel cobalt oxide is used as a catalyst, and a pure nickel mesh electrode for hydrogen generation is used for the cathode, and the electrolysis area of the electrolysis unit is set to 1 dm 2 The voltage required for flowing a unit current of 50 A / dm 2 to the electrolysis unit from the electrolysis device is measured, and the voltage at 50 A / dm 2the voltage at the time of 50 A / dm 2 The greater the voltage at the time of 50 A / dm 2 The voltage at the time of 50 A / dm 2 at 85°C can also be referred to as the voltage at the time of 50 A / dm

[0075] For the alkaline water electrolysis separator of the present application, from the viewpoint that the hydrophilicity is maintained even over a long period of time, and further the high ion permeability is maintained, the ratio of the hydrophilic speed at the time of immersion in an aqueous solution having a pH of 13 at 130°C for 1000 hours to the initial value is preferably 40.0% or greater, further preferably 60.0% or greater, more preferably 80.0% or greater, particularly preferably 90.0% or greater, especially preferably 95.0% or greater, and most preferably 98.0% or greater.

[0076] The method of measuring the ratio of the hydrophilic speed of the alkaline water electrolysis separator at the time of immersion in an aqueous solution having a pH of 13 at 130°C for 1000 hours to the initial value is not particularly limited, and for example, it can be measured as follows: a drop of water of about 0.05 ml is added to the surface of the alkaline water electrolysis separator in a laboratory, the time (seconds) from when the water drop contacts the surface of the alkaline water electrolysis separator until it is completely absorbed by the alkaline water electrolysis separator is measured as the water immersion time t0, then the alkaline water electrolysis separator is immersed in an aqueous solution having a pH of 13 at 130°C for 1000 hours in an alkaline water electrolysis tank, and after being taken out and dried, the water immersion time t 1000 after 1000 hours is measured in the same manner as the initial water immersion time, and the percentage obtained by dividing t0 by t 1000 is calculated as the ratio of the hydrophilic speed of the alkaline water electrolysis separator at the time of immersion in an aqueous solution having a pH of 13 at 130°C for 1000 hours to the initial value.

[0077] Further, for the alkaline water electrolysis separator of the present application, from the viewpoint that the hydrophilicity is maintained even over a long period of time, and further the high ion permeability is maintained, the ratio of the hydrophilic speed at the time of immersion in an aqueous solution having a pH of 13 at 85°C for 1000 hours to the initial value is preferably 90.0% or greater, further preferably 95.0% or greater, more preferably 100.0% or greater, and in addition, is usually 120.0% or less.

[0078] The method for measuring the ratio of the water absorbency rate of the alkaline water electrolysis diaphragm after 1000 hours of immersion in an aqueous solution having a pH of 13 at 85°C to the initial value is not particularly limited, and for example, it can be measured as follows: a drop of water of about 0.01 ml is added to the surface of the alkaline water electrolysis diaphragm in a laboratory, the time (seconds) from when the drop of water contacts the surface of the alkaline water electrolysis diaphragm until it is completely absorbed by the alkaline water electrolysis diaphragm is measured as the water absorption time t'0, and then the alkaline water electrolysis diaphragm is immersed in an alkaline water electrolysis tank at 85°C, typically in an aqueous solution having a pH of 13 at 85°C for 1000 hours, is removed and dried, and after that, the water absorption time t'1000 after 1000 hours of immersion is measured in the same manner as the initial water absorption time, and the percentage obtained by dividing t'0 by t'1000 is calculated as the ratio of the water absorbency rate of the alkaline water electrolysis diaphragm after 1000 hours of immersion in an aqueous solution having a pH of 13 at 85°C to the initial value. 1000 1000 When the measurement temperature is set to 85°C, the ratio of the water absorbency rate after 1000 hours of immersion in an aqueous solution having a pH of 13 at 85°C to the initial value can also be referred to as the ratio of the water absorbency rate after 1000 hours of immersion in an aqueous solution having a pH of 13 at 85°C to the initial value.

[0079] [Second Embodiment]

[0080] The second embodiment of the present application relates to an alkaline water electrolysis diaphragm comprising a porous resin and a porous support, the porous support comprising at least any one selected from the group consisting of a spunlace nonwoven fabric and a papermaking.

[0081] In the second embodiment, the porous support comprises at least any one selected from the group consisting of a spunlace nonwoven fabric and a papermaking. By using a spunlace nonwoven fabric and / or a papermaking, the detachment of the hydrophilic agent from the alkaline water electrolysis diaphragm can be suppressed, and thus the ion permeability can be maintained for a long period of time, and the hydrogen production efficiency in the long-term operation of the alkaline electrolysis tank can be improved.

[0082] Note that in the second embodiment, the type of the hydrophilic agent that can be contained in the porous resin is not particularly limited, and the aforementioned surfactant, the aforementioned hydrophilic inorganic particles, and the like can be exemplified. In other words, in the second embodiment, as long as the porous support uses a spunlace nonwoven fabric and / or a papermaking, the effect of suppressing the detachment of the hydrophilic agent from the alkaline water electrolysis diaphragm can be exerted, and the presence or absence of this effect is not dependent on the type of the hydrophilic agent. From the viewpoint of further exerting the effect of suppressing the detachment of the hydrophilic agent from the alkaline water electrolysis diaphragm, maintaining the ion permeability for a long period of time, and achieving higher hydrogen production efficiency, it is preferable to use a surfactant as the hydrophilic agent. As for the type and content of the surfactant, the same type and content of the surfactant as described in the aforementioned first embodiment can be preferably used.

[0083] ​As the resin or the like constituting the porous support, the same resin or the like as described in the first embodiment can be used.

[0084] As the resin for forming the porous resin, the manufacturing method, and the like, the same resin and the manufacturing method as described in the first embodiment can be used.

[0085] As the preferable range of the specific resistance of the alkaline water electrolysis separator, the ratio of the hydrophilic speed at 130°C in a water solution having a pH of 13 when immersed for 1000 hours to the initial value, and the measurement method, and the like, the same preferable range and measurement method as described in the first embodiment can be used.

[0086] Examples

[0087] The embodiments of the present application will be described in detail below with reference to Examples, but it will be understood by those skilled in the art that the following Examples are for illustration only and should not be taken as limiting the scope of the present application. In the Examples, when specific conditions are not mentioned, they are carried out under conventional conditions or conditions recommended by the manufacturer. When the reagents or instruments used are not mentioned by the manufacturer, they are all conventional products that can be obtained commercially.

[0088] The following Example Series A and Example Series C correspond to the first embodiment described above, and Example Series B corresponds to the second embodiment described above.

[0089] [Examples Al to A4, Comparative Examples Al to A4]

[0090] A polyphenylene sulfide fiber paper (PPS 100%, weight per unit area 41.1 g / m 2 , thickness 119 μm) of 1.3 dTex x 10 mm was used as the porous support. A polyphenylsulfone resin was used as the porous resin, dissolved in N-methyl-2-pyrrolidone, and mixed therein with a basic sulfonic acid-based surfactant (HOSTAPUR (registered trademark) SAS93) so that the content thereof was 10 wt% relative to the solid components of the porous resin, to obtain a coating material. The porous support was immersed in the obtained coating material by a dip coater to form a porous resin film on the surface of the porous support, at this time, by adjusting the number of immersions, the content of the surfactant on the support was made to be the hydrophilic agent addition amount shown in Table 1 relative to the entire solid components contained in the porous resin, to obtain an alkaline water electrolysis separator comprising the porous support and the porous resin.

[0091] The specific resistance, the surface hydrophilic speed, the gas barrier property, and the 1000-hour hydrogen production amount of each of the alkaline water electrolysis separators obtained in Examples Al to A4 and Comparative Examples Al to A4 were measured by the following methods, and the evaluation results are shown in Table 1.

[0092] [Conductive resistance]

[0093] An alkaline water electrolysis diaphragm was installed in an electrolysis device, in which an electrolyte was used with a 25% mass concentration of an aqueous potassium hydroxide solution, a liquid temperature was set to 80°C, a pure nickel mesh was used for an anode, a nickel cobalt oxide was used as a catalyst, a platinum mesh electrode for hydrogen generation was used for a cathode, and an electrolysis area of an electrolysis unit was set to 1 dm 2 . An electrolysis voltage required for a unit current of 60 A / dm 2 to flow from the electrolysis device to the electrolysis unit was measured. The voltage at 60 A / dm 2 was used as an index indicating a conductive resistance. The greater the voltage at 60 A / dm 2 , the greater the conductive resistance.

[0094] [Surface hydrophilicity speed]

[0095] A drop of water of about 0.05 ml was added to the surface of an alkaline water electrolysis diaphragm in a laboratory at normal temperature and pressure, and a time (sec) taken for the water drop to contact the surface of the alkaline water electrolysis diaphragm until completely absorbed by the alkaline water electrolysis diaphragm was measured as a water immersion time t0. Then, the alkaline water electrolysis diaphragm was immersed in an aqueous solution having a pH of 13 at 130°C in an alkaline water electrolysis tank for 1000 hours, taken out and dried, and after that, a water immersion time t 1000 after the 1000 hours of immersion was measured in the same manner as the initial value of the water immersion time, and a percentage obtained by dividing t0 by t 1000 was calculated as a ratio of a hydrophilicity speed of the alkaline water electrolysis diaphragm at 130°C in the aqueous solution having a pH of 13 for 1000 hours to the initial value. The surface water immersion time was used as an index indicating the surface hydrophilicity speed. The longer the surface water immersion time, the slower the surface hydrophilicity speed.

[0096] Further, a ratio (%) of the hydrophilicity speed at 1000 hours to the initial value was calculated as an index indicating a hydrophilicity maintenance ability.

[0097] [Gas barrier property]

[0098] The gas tightness of the alkaline water electrolysis diaphragm was measured according to JC / T-211-2009. The gas barrier property was evaluated based on the following criteria.

[0099] ◎: 400 mmH2O < gas tightness

[0100] ○: 400 mmH2O ≥ gas tightness > 350 mmH2O

[0101] ×: 350 mmH2O ≥ gas tightness

[0102] [1000 hours hydrogen production amount]

[0103] An alkaline water electrolysis separator having a diameter of 226 mm was installed in an electrolysis device, the volume of the electrolysis tank was set to 4 L, the liquid temperature was set to 130°C, and the hydrogen production amount after 1000 hours of operation of the electrolysis device was measured.

[0104] Table 1

[0105] The materials used in Table 1 are as follows.

[0106] Surfactant: Alkali sulfonic acid-based surfactant (HOSTAPUR (registered trademark) SAS93)

[0107] Inorganic particles: Silica nanoparticles (Organosilica FITC manufactured by Tokyo Chemical Industry Co., Ltd.)

[0108] It was found that the alkaline water electrolysis separators of Examples Al to A4, which contain a porous support and a porous resin containing a surfactant, have low electric resistance, excellent gas barrier properties, and can maintain hydrophilicity over a long period of time, and thus have excellent hydrogen production efficiency. On the other hand, in Comparative Examples Al to A4, inorganic particles were used as a hydrophilic agent in the porous resin, and although the electric resistance was low and the gas barrier properties were excellent at the initial stage, the hydrophilicity could not be maintained over a long period of time, and the hydrogen production efficiency was low.

[0109] [Examples Bl to B2 and Comparative Examples Bl to B2]

[0110] In Example Al, at least one of the porous support, the hydrophilic agent, and the amount of addition thereof was changed as shown in Table 2, and otherwise, the same operation as in Example Al was performed to obtain an alkaline water electrolysis separator containing a porous support and a porous resin.

[0111] The electric resistance, the surface hydrophilization speed, the gas barrier properties, and the 1000-hour hydrogen production amount of each of the alkaline water electrolysis separators obtained in Examples Bl to B2 and Comparative Examples Bl to B2 were measured by the above-described methods, and the evaluation results are shown together in Table 2.

[0112] Table 2

[0113] The materials used in Table 2 are as follows.

[0114] Surfactant: Alkali sulfonic acid-based surfactant (HOSTAPUR (registered trademark) SAS93)

[0115] Inorganic particles: Silica nanoparticles (Organosilica FITC manufactured by Tokyo Chemical Industry Co., Ltd.)

[0116] Papermaking: 1.3 dTex x 10 mm PPS 100%, basis weight 41.1 g / m22 , thickness 119 μm

[0117] Spunlace nonwoven fabric: 1.3 dTex x 38 mm PPS 100%, unit area weight 53 g / m 2 , thickness 81 μm

[0118] Woven fabric: PPS 100%, unit area weight 56 g / m 2 , thickness 197 μm

[0119] It was found that the alkaline water electrolysis separators of Examples B1 to B2, which used a porous resin containing a surfactant and a spunlace nonwoven fabric or a papermaking fabric as the porous support, had not only low electric conductivity resistance and excellent gas barrier properties, but also maintained hydrophilicity over a long period of time, achieving excellent hydrogen production efficiency. On the other hand, in Comparative Example B1, a porous resin containing inorganic particles as a hydrophilic agent was used, and although the electric conductivity resistance was low and the gas barrier properties were excellent at the initial stage, the hydrophilicity could not be maintained over a long period of time, and the hydrogen production efficiency was low. In Comparative Example B2, a woven fabric was used as the porous support, and although the gas barrier properties were excellent, the electric conductivity resistance was large, and since inorganic particles were used as the hydrophilic agent, the hydrophilicity could not be maintained over a long period of time, and thus the hydrogen production efficiency was low.

[0120] [Examples C1 to C4, Comparative Examples C1 to C4]

[0121] A 0.89 dTex x 51 mm polyphenylene sulfide fiber spunlace fabric (PPS 100%, unit area weight 89.0 g / m 2 , thickness 180 μm) was used as the porous support. A polyphenylsulfone resin was used as the porous resin, dissolved in N-methyl-2-pyrrolidone, and a basic sulfonic acid-based surfactant (HOSTAPUR (registered trademark) SAS93) was mixed therein so that the content thereof with respect to the solid content of the porous resin was the addition amount shown in Table 3, to obtain a coating material. The porous support was impregnated in the obtained coating material by a dipping machine to form a porous resin film on the surface of the porous support, and at this time, the content of the surfactant on the support with respect to the total solid content contained in the porous resin was adjusted to be the hydrophilic agent addition amount shown in Table 3 by adjusting the number of times of dipping, to obtain an alkaline water electrolysis separator containing the porous support and the porous resin.

[0122] The electric conductivity resistance, the ratio of the hydrophilic speed at 1000 hours to the initial value, the gas barrier properties, and the hydrogen production amount at 1000 hours of each of the alkaline water electrolysis separators obtained in Examples C1 to C4 and Comparative Examples C1 to C4 were measured by the following methods, and the evaluation results are shown together in Table 3.

[0123] [Electric conductivity resistance]

[0124] An alkaline water electrolysis diaphragm was installed in an electrolysis device, in which an aqueous potassium hydroxide solution having a mass concentration of 30% was used as an electrolyte, the liquid temperature was set to 85°C, a pure nickel mesh was used as an anode, nickel cobalt oxide was used as a catalyst, a pure nickel mesh electrode for hydrogen generation was used as a cathode, and the electrolysis area of the electrolysis unit was set to 1 dm 2 The electrolysis voltage required for a unit current of 50 A / dm 2 to flow from the electrolysis device to the electrolysis unit was measured. The voltage at 50 A / dm 2 was used as an index indicating the electric conduction resistance. The greater the voltage at 50 A / dm 2 , the greater the electric conduction resistance.

[0125] [Ratio of hydrophilic speed at 1000 hours to initial value]

[0126] A drop of water of about 0.01 ml was added to the surface of an alkaline water electrolysis diaphragm in a laboratory at normal temperature and pressure, and the time (seconds) taken for the water drop to contact the surface of the alkaline water electrolysis diaphragm until it was completely absorbed by the alkaline water electrolysis diaphragm was measured as the initial water immersion time. Then, the alkaline water electrolysis diaphragm was immersed in an aqueous solution having a pH of 13 at 85°C in an alkaline water electrolysis tank for 1000 hours, taken out and dried, and after that, the water immersion time after 1000 hours of immersion was measured in the same manner as the initial water immersion time, and the percentage obtained by dividing the water immersion time after 1000 hours of immersion by the initial water immersion time was calculated as the ratio of the hydrophilic speed at 1000 hours to the initial value of the alkaline water electrolysis diaphragm when immersed in an aqueous solution having a pH of 13 at 85°C for 1000 hours. The ratio of the hydrophilic speed at 1000 hours to the initial value is an index indicating the hydrophilic property maintenance ability.

[0127] [Gas barrier property]

[0128] The gas tightness of the alkaline water electrolysis diaphragm was measured in accordance with JC / T-211-2009. The gas barrier property was evaluated based on the following criteria.

[0129] ◎: 400 mm H2O < gas tightness

[0130] ○: 400 mm H2O ≥ gas tightness > 350 mm H2O

[0131] ×: 350 mm H2O ≥ gas tightness

[0132] [1000 hours hydrogen production amount]

[0133] An alkaline water electrolysis diaphragm was installed in an electrolysis device, the diameter of the alkaline water electrolysis diaphragm was set to 226 mm, the volume of the electrolysis tank was set to 4 L, the liquid temperature was set to 85°C, and the hydrogen production amount of the electrolysis device after 1000 hours of operation was measured.

[0134] Table 3

[0135] The materials used in Table 3 are as follows.

[0136] Surfactant: basic sulfonic acid-based surfactant (HOSTAPUR (registered trademark) SAS93)

[0137] Inorganic particles: silica nanoparticles (Organosilica FITC manufactured by Tokyo Chemical Industry Co., Ltd.)

[0138] It is known that the basic water electrolysis separators of Examples C1 to C4, which contain a porous support and a porous resin containing a surfactant, not only have low electric resistance and excellent gas barrier properties, but also can maintain hydrophilicity during long-term operation, achieving excellent hydrogen production efficiency. On the other hand, in Comparative Examples C1 to C4, inorganic particles are used as a hydrophilic agent in the porous resin, and the inorganic particles gradually fall off during long-term operation, resulting in a failure to maintain hydrophilicity and low hydrogen production efficiency.

[0139] Note that although the technical solutions of the present application are described with specific examples, those skilled in the art can understand that the present application should not be limited thereto.

[0140] The above has described various embodiments of the present application, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other ordinary skilled persons in the art to understand the embodiments disclosed herein.

[0141] Industrial applicability

[0142] The basic water electrolysis separator substrate of the present application can be widely used in the field of hydrogen production using basic water electrolysis, etc.

Claims

1. An alkaline water electrolysis separator, characterized in that, It comprises a porous support and a porous resin containing a surfactant.

2. The alkaline water electrolysis separator according to claim 1, characterized in that The surfactant content is 1 to 40 wt% relative to the total solid content of the porous resin.

3. The alkaline water electrolysis separator according to claim 1 or 2, characterized in that, The porous support comprises at least any one selected from the group consisting of a woven fabric, a knitted fabric, a nonwoven fabric, and a papermaking.

4. The alkaline water electrolysis separator according to any one of claims 1 to 3, characterized in that, The porous support comprises at least any one selected from the group consisting of a spunlace nonwoven fabric and a papermaking.

5. The alkaline water electrolysis separator according to any one of claims 1 to 4, characterized in that, The porous support is composed mainly of polyphenylene sulfide fibers.

6. The alkaline water electrolysis separator according to any one of claims 1 to 5, characterized in that, The porous resin is at least any one selected from the group consisting of polyphenylene sulfide, polyphenylsulfone, polysulfone, and polyethersulfone.

7. The alkaline water electrolysis separator according to any one of claims 1 to 6, characterized in that, The conductive resistance satisfies: the voltage at 60 A / dm 2 is 1.90 V or less.

8. The alkaline water electrolysis separator according to any one of claims 1 to 7, characterized in that, The hydrophilic speed after immersion in an aqueous solution at 130°C with pH 13 for 1000 hours is 40.0% or more relative to the initial value.

9. The alkaline water electrolysis separator according to any one of claims 1 to 6, characterized in that, The conductive resistance satisfies: the voltage at 50 A / dm 2 2 is 40 V or less, and the hydrophilic speed relative to the initial value when immersed in an aqueous solution having a pH of 13 at 85°C for 1000 hours is 90.0% or more.

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