Electrolyte membrane laminate, electrolyte membrane equipped with catalyst layer, membrane electrode conjugate, hydrolysis-type hydrogen generation device, and method for producing electrolyte membrane equipped with catalyst layer

Abstract

An electrolyte membrane laminate according to the present invention comprises, in the stated order, a first electrolyte membrane having a first primary surface and a second primary surface, and a first intermediate layer and a second electrolyte membrane on the first primary surface of the first electrolyte layer. The first electrolyte membrane includes a hydrocarbon-based polyelectrolyte. The first intermediate layer includes a polyelectrolyte and particles. The second electrolyte membrane includes a polyelectrolyte and particles containing a transition metal element.　Provided is an electrolyte membrane laminate having excellent hydrogen barrier properties and good durability.

Description

Electrolyte membrane laminate, catalyst-layered electrolyte membrane, membrane electrode assembly, water electrolysis-type hydrogen generation device, and method for manufacturing catalyst-layered electrolyte membrane

[0001] The present invention relates to an electrolyte membrane laminate, a catalyst-coated electrolyte membrane, a membrane electrode assembly, a water electrolysis-type hydrogen generation device, and a method for producing a catalyst-coated electrolyte membrane.

[0002] In recent years, hydrogen energy has been attracting attention as a next-generation energy storage and transportation method. When used as fuel for fuel cells, hydrogen can be converted into electricity with theoretically higher energy efficiency than power generation using heat engines, and because it produces no harmful emissions, it has the potential to be a highly efficient, clean energy source.

[0003] One method of producing hydrogen is water electrolysis. If surplus electricity generated by renewable energy is used to electrolyze water, it is possible to convert electricity into hydrogen energy without emitting carbon dioxide. Furthermore, depending on the storage method, hydrogen can be transported by tank truck or tanker and supplied when and where it is needed, making water electrolysis a highly promising tool for storing electricity.

[0004] There are two methods for producing hydrogen through water electrolysis: alkaline water electrolysis and polymer electrolyte membrane (PEM) water electrolysis. PEM water electrolysis has the advantage of being able to operate at high current densities and can flexibly respond to fluctuations in renewable energy output.

[0005] However, if the electrolyte membrane used in a PEM-type water electrolysis cell does not have sufficient hydrogen barrier properties, the generated hydrogen will permeate from the cathode to the anode, resulting in the generation of a mixed gas of hydrogen and oxygen at the anode, posing a safety issue.

[0006] In view of this, examples have been reported in which a layer containing a platinum group metal (platinum group metal-containing layer) is provided between the electrolyte membrane and the anode, and hydrogen that permeates and diffuses through the electrolyte membrane is reacted with the generated oxygen by catalytic action to form water, thereby reducing the hydrogen concentration at the anode (Patent Documents 1 and 2).

[0007] On the other hand, fluorine-based polymer electrolytes such as perfluorocarbon sulfonic acid have been generally known as polymer electrolytes constituting electrolyte membranes. The above-mentioned Patent Documents 1 and 2 use fluorine-based polymer electrolytes. However, these fluorine-based polymer electrolytes have problems such as being expensive, having relatively poor hydrogen barrier properties, and having relatively low mechanical strength at high temperatures. Therefore, the use of hydrocarbon-based polymer electrolytes instead of fluorine-based polymer electrolytes has been considered.

[0008] JP 2020-514528 A JP 2019-167619 A

[0009] Although electrolyte membranes using hydrocarbon electrolytes have relatively good hydrogen barrier properties compared to fluorine-based electrolyte membranes, it was important to further reduce hydrogen permeation to the anode in order to continue safe hydrogen production. Attempts were made to laminate a platinum group metal-containing layer as described above on the electrolyte membrane to decompose permeating hydrogen, but it was found that the adhesion between the electrolyte membrane and the platinum group metal-containing layer was poor, posing a durability issue.

[0010] Therefore, an object of the present invention is to provide an electrolyte membrane laminate that has excellent hydrogen barrier properties and good durability. Another object of the present invention is to provide a catalyst-layered electrolyte membrane that has excellent hydrogen barrier properties and good durability, and a method for producing the same. A further object of the present invention is to provide a membrane electrode assembly that has excellent hydrogen barrier properties and good durability. Another object of the present invention is to provide a water electrolysis hydrogen generation device.

[0011] In order to achieve the above object, the electrolyte membrane laminate of the present invention has the following configuration: an electrolyte membrane laminate including a first electrolyte membrane having a first main surface and a second main surface, and a first intermediate layer and a second electrolyte membrane, in this order, on the first main surface of the first electrolyte membrane, wherein the first electrolyte membrane contains a hydrocarbon-based polymer electrolyte, the first intermediate layer contains a polymer electrolyte and particles, and the second electrolyte membrane contains a polymer electrolyte and particles containing a transition metal element.

[0012] In order to achieve the above object, the catalyst-layered electrolyte membrane of the present invention has the following configuration: A catalyst-layered electrolyte membrane having a catalyst layer on each of both sides of the electrolyte membrane laminate, the catalyst-layered electrolyte membrane having a first catalyst layer on the first main surface side of the first electrolyte membrane of the electrolyte membrane laminate, and a second catalyst layer on the second main surface side of the first electrolyte membrane.

[0013] In order to achieve the above object, the membrane electrode assembly of the present invention has the following configuration: That is, the membrane electrode assembly includes the above-mentioned catalyst layer-equipped electrolyte membrane.

[0014] In order to achieve the above object, the water electrolysis hydrogen generation device of the present invention has the following configuration: That is, the water electrolysis hydrogen generation device includes the above-described catalyst layer-equipped electrolyte membrane.

[0015] In order to achieve the above object, the method for producing a catalyst-coated electrolyte membrane of the present invention adopts any one of the following configurations: That is, a laminate (L) in which a first intermediate layer is laminated on a first electrolyte membrane, and a first catalyst layer transfer sheet (T) in which a first catalyst layer and a second electrolyte membrane are laminated in this order on a first support. Ｃ１ ) and a second catalyst layer transfer sheet (T Ｃ２ ) and the first intermediate layer of the laminate (L) and the first catalyst layer transfer sheet (T Ｃ１ ) is brought into contact with the second electrolyte membrane of the laminate (L), and the first electrolyte membrane of the laminate (L) and the second catalyst layer transfer sheet (T Ｃ２ a laminate (L) in which a first intermediate layer is laminated on a first electrolyte membrane, and a first catalyst layer transfer sheet (T) in which a first catalyst layer and a second electrolyte membrane are laminated in this order on a first support, Ｃ１ ), and a second catalyst layer transfer sheet (T Ｃ３ ) and the first intermediate layer of the laminate (L) and the first catalyst layer transfer sheet (T Ｃ１ ) is brought into contact with the second electrolyte membrane of the laminate (L), and the first electrolyte membrane of the laminate (L) and the second catalyst layer transfer sheet (T Ｃ３ ) and a second intermediate layer.

[0016] The electrolyte membrane laminate of the present invention preferably includes a third electrolyte membrane on the second main surface of the first electrolyte membrane.

[0017] The electrolyte membrane laminate of the present invention preferably includes a second intermediate layer between the second main surface of the first electrolyte membrane and the third electrolyte membrane, the second intermediate layer containing a polymer electrolyte and particles.

[0018] In the electrolyte membrane laminate of the present invention, the polymer electrolyte contained in the second electrolyte membrane and / or the third electrolyte membrane preferably contains a fluorine-based polymer electrolyte.

[0019] In the electrolyte membrane laminate of the present invention, the particles containing a transition metal element contained in the second electrolyte membrane and / or the third electrolyte membrane are preferably particles containing at least one transition metal element selected from platinum, gold, silver, copper, palladium, ruthenium, rhodium, cerium, manganese, iridium, nickel, and cobalt.

[0020] In the electrolyte membrane laminate of the present invention, it is preferable that the particles containing a transition metal element contained in the second electrolyte membrane and / or the third electrolyte membrane include at least one kind selected from particles of a zero-valent metal, particles of a metal oxide, and particles of a sparingly soluble metal salt.

[0021] In the electrolyte membrane laminate of the present invention, it is preferable that the mass ratio of the particles containing a transition metal element to the polymer electrolyte contained in the second electrolyte membrane and / or the third electrolyte membrane (mass of the particles containing a transition metal element / mass of the polymer electrolyte) is 0.01 to 0.85.

[0022] In the electrolyte membrane laminate of the present invention, the particles contained in the first intermediate layer and / or the second intermediate layer are preferably inorganic particles.

[0023] In the electrolyte membrane laminate of the present invention, it is preferable that the particles contained in the first intermediate layer and / or the second intermediate layer are particles containing carbon atoms.

[0024] In the electrolyte membrane laminate of the present invention, the particles contained in the first intermediate layer and / or the second intermediate layer are preferably carbon particles and / or metal-supported carbon particles.

[0025] In the electrolyte membrane laminate of the present invention, the particles contained in the first intermediate layer and / or the second intermediate layer are preferably carbon particles.

[0026] In the electrolyte membrane laminate of the present invention, the polymer electrolyte contained in the first intermediate layer and / or the second intermediate layer preferably contains a fluorine-based polymer electrolyte.

[0027] In the electrolyte membrane laminate of the present invention, the mass ratio of particles to polymer electrolyte contained in the first intermediate layer and / or the second intermediate layer (mass of particles / mass of polymer electrolyte) is preferably 0.4 to 20.0.

[0028] In the electrolyte membrane laminate of the present invention, the hydrocarbon-based polymer electrolyte contained in the first electrolyte membrane preferably contains an aromatic polyether-based polymer electrolyte.

[0029] In the catalyst-coated electrolyte membrane of the present invention, the first catalyst layer is preferably an anode catalyst layer, and the second catalyst layer is preferably a cathode catalyst layer.

[0030] In the method for producing a catalyst-coated electrolyte membrane of the present invention, the first electrolyte membrane preferably contains a hydrocarbon-based polymer electrolyte, and the first bonding layer preferably contains a polymer electrolyte and inorganic particles.

[0031] In the method for producing a catalyst-coated electrolyte membrane of the present invention, the catalyst-coated electrolyte membrane is preferably in the form of a long film.

[0032] According to the present invention, an electrolyte membrane laminate having excellent hydrogen barrier properties and good durability can be provided.

[0033] Hereinafter, the embodiments of the present invention will be described in detail, but the present invention is not limited to the following embodiments and can be implemented with various modifications depending on the purpose and application.

[0034] The electrolyte membrane laminate of the present invention comprises, in this order: a first electrolyte membrane containing a hydrocarbon-based polymer electrolyte; a first intermediate layer containing a polymer electrolyte and particles on a first main surface of the first electrolyte membrane; and a second electrolyte membrane containing a polymer electrolyte and particles containing a transition metal element.

[0035] [First Electrolyte Membrane] The first electrolyte membrane contains a hydrocarbon-based polymer electrolyte. Here, the hydrocarbon-based polymer electrolyte is a hydrocarbon-based polymer having an ionic group. The hydrocarbon-based polymer having an ionic group refers to a polymer having a main chain whose main structural unit is hydrocarbon and to which an ionic group is attached to the main chain or a side chain, and the main chain or the side chain is substantially not fluorinated. Note that the term "substantially not fluorinated" does not exclude polymers having a fluorinated portion in only a small part of the main chain or the side chain, and specifically includes hydrocarbon-based polymers having a fluorine atom content of less than 5% by mass per number average molecular weight of the polymer.

[0036] The hydrocarbon-based polymer electrolyte is preferably an aromatic hydrocarbon-based polymer having an aromatic ring in the main chain. The aromatic ring may be not only a hydrocarbon-based aromatic ring but also a heterocycle. Furthermore, the polymer may contain aliphatic units in addition to the aromatic ring units.

[0037] Specific examples of aromatic hydrocarbon polymers include polymers having a structure selected from polysulfone, polyethersulfone, polyphenylene oxide, polyarylene ether polymers, polyphenylene sulfide, polyphenylene sulfide sulfone, polyparaphenylene, polyarylene polymers, polyarylene ketone, polyether ketone, polyarylene phosphine oxide, polyether phosphine oxide, polybenzoxazole, polybenzothiazole, polybenzimidazole, polyamide, polyimide, polyetherimide, and polyimide sulfone in the main chain together with an aromatic ring. Note that the terms "polysulfone," "polyethersulfone," and "polyether ketone" are generic terms for structures having sulfone bonds, ether bonds, and ketone bonds in the molecular chain, and include polyether ketone ketone, polyether ether ketone, polyether ether ketone ketone, polyether ketone ether ketone ketone, and polyether ketone sulfone. The hydrocarbon skeleton may have multiple structures selected from these structures. Among these, the aromatic hydrocarbon polymer is most preferably a polymer having a polyether ketone skeleton, that is, a polyether ketone polymer.

[0038] The polymer electrolyte is preferably one that forms a bicontinuous or lamellar phase separation structure. Such a phase separation structure can be formed, for example, in a molded article made of a blend of two or more incompatible polymers, such as a hydrophilic polymer having an ionic group and a hydrophobic polymer having no ionic group, or in a polymer having a segment (S Ｅ１ ) and a segment (S Ｅ２This can occur in block copolymers composed of two or more incompatible segments, such as ethylenediaminetetraacetic acid (EDTA). In bicontinuous and lamellar phase-separated structures, both the hydrophilic and hydrophobic domains form continuous phases, leading to the formation of continuous proton-conducting channels, which facilitate the production of electrolyte membranes with excellent proton conductivity. At the same time, the formation of a continuous hydrophobic backbone facilitates the production of electrolyte membranes with excellent mechanical properties, both in the dry and hydrated states. Here, "domain" refers to a mass formed by the aggregation of similar substances or segments within a single membrane.

[0039] As the polymer electrolyte, in particular, a segment containing an ionic group (S Ｅ１ ) and a segment (S Ｅ２ ) is preferred. Here, the segment refers to a partial structure in a copolymer polymer chain consisting of repeating units that exhibit specific properties and has a molecular weight of 2,000 or more. The use of a block copolymer makes it possible to develop a bicontinuous or lamellar phase-separated structure with finer domains than a polymer blend, thereby achieving better power generation performance, hydrogen generation efficiency, and physical durability.

[0040] Hereinafter, the segment containing an ionic group (S Ｅ１ ) or polymer may be referred to as an "ionic block", and a segment (S Ｅ２ ) or polymer may be referred to as a “nonionic block.” However, the expression “containing no ionic groups” in this specification does not exclude an embodiment in which the segment or polymer contains a small amount of ionic groups to the extent that the formation of a phase-separated structure is not inhibited.

[0041] Such block copolymers have a molar composition ratio of ionic block to nonionic block (S Ｅ１ / S Ｅ２ ) is preferably 0.20 or more, more preferably 0.33 or more, and even more preferably 0.50 or more.Ｅ１ / S Ｅ２ The molar composition ratio (S) is preferably 5.00 or less, more preferably 3.00 or less, and even more preferably 2.50 or less. Ｅ１ / S Ｅ２ When the molar composition ratio (S) is 0.20 or more or 5.00 or less, a composite polymer electrolyte membrane having high proton conductivity under low humidification conditions and excellent hot water resistance and physical durability can be obtained. Ｅ１ / S Ｅ２ The "molar number of repeating units" refers to the ratio of the number of moles of repeating units present in the ionic block to the number of moles of repeating units present in the nonionic block. The "molar number of repeating units" is the value obtained by dividing the number average molecular weight of the ionic block and the nonionic block by the molecular weight of the corresponding structural unit.

[0042] The ionic group in the polymer electrolyte may be an ionic group having either cation exchange capability or anion exchange capability. Examples of such functional groups that are preferably used include sulfonic acid groups, sulfonimide groups, sulfate groups, phosphonic acid groups, phosphate groups, carboxylic acid groups, ammonium groups, phosphonium groups, and amino groups. Two or more types of ionic groups can be contained in the polymer. Among these, the polymer more preferably has at least one selected from sulfonic acid groups, sulfonimide groups, and sulfate groups, as these groups provide excellent water electrolysis performance, and most preferably has a sulfonic acid group from the viewpoint of raw material costs.

[0043] The ion exchange capacity (IEC) of the polymer electrolyte is preferably 0.1 meq / g or more and 5.0 meq / g or less in terms of the balance between proton conductivity and water resistance. The IEC is more preferably 1.0 meq / g or more, and even more preferably 1.4 meq / g or more. The IEC is more preferably 3.5 meq / g or less, and even more preferably 3.0 meq / g or less. When the IEC is 0.1 meq / g or more and 5.0 meq / g or less, excellent proton conductivity and water resistance can both be achieved.

[0044] Here, IEC is the molar amount of ionic groups introduced per unit dry weight of the polymer electrolyte, and the larger this value, the greater the amount of ionic groups introduced. In the present invention, IEC is defined as a value determined by neutralization titration. Calculation of IEC by neutralization titration can be performed by the method described in the Examples.

[0045] In the present invention, from the viewpoint of hydrogen generation efficiency in a water electrolysis-type hydrogen generator, it is particularly preferable to use an aromatic hydrocarbon-based block copolymer as the polymer electrolyte, and more preferably a polyether ketone-based block copolymer. In particular, a polyether ketone-based block copolymer containing a segment including a structural unit (S1) containing an ionic group and a segment including a structural unit (S2) not containing an ionic group, as shown below, can be particularly preferably used.

[0046]

[0047] In general formula (S1), Ar １ ~Ar ４ represents any divalent arylene group, Ar １ and / or Ar ２ contains an ionic group, and Ar ３ and Ar ４ may or may not contain an ionic group. １ ~Ar ４ may be optionally substituted, and two or more types of arylene groups may be used independently. * represents a bonding site with general formula (S1) or another structural unit.

[0048]

[0049] In general formula (S2), Ar ５ ~Ar ８ represents any divalent arylene group, which may be optionally substituted but does not contain an ionic group. ５ ~Ar ８ may independently use two or more types of arylene groups. * represents a bonding site with general formula (S2) or another structural unit.

[0050] Here, Ar １~Ar ８ Preferred divalent arylene groups as Ar include hydrocarbon arylene groups such as phenylene, naphthylene, biphenylene, and fluorenediyl groups, and heteroarylene groups such as pyridinediyl, quinoxalinediyl, and thiophenediyl, but are not limited thereto. Here, the phenylene group can be classified into three types, o-phenylene, m-phenylene, and p-phenylene, depending on the bonding site between the benzene ring and other structural units, and these are used as a general term unless otherwise specified in the present specification. The same applies to other divalent arylene groups such as naphthylene and biphenylene groups. Ar １ ~Ar ８ is preferably a phenylene group and a phenylene group containing an ionic group, and most preferably a p-phenylene group and a p-phenylene group containing an ionic group. ５ ~Ar ８ may be substituted with a group other than an ionic group, but is preferably unsubstituted in terms of proton conductivity, chemical stability, and physical durability.

[0051] In order to obtain sufficient dimensional stability, mechanical strength, physical durability, fuel barrier properties, and solvent resistance, the polymer electrolyte is preferably an aromatic hydrocarbon polymer having crystallinity. Here, "having crystallinity" means that the polymer electrolyte has the property of being crystallizable by heating, or that the polymer electrolyte is already crystallized.

[0052] The presence or absence of crystallinity is confirmed by differential scanning calorimetry (DSC) or wide-angle X-ray diffraction. In the present invention, it is preferable that the heat of crystallization measured by DSC after film formation is 0.1 J / g or more, or the crystallinity measured by wide-angle X-ray diffraction is 0.5% or more. That is, if no crystallization peak is observed in DSC, it is possible that the polymer electrolyte has already crystallized or is amorphous. If the polymer electrolyte has already crystallized, the crystallinity measured by wide-angle X-ray diffraction will be 0.5% or more.

[0053] Crystalline aromatic hydrocarbon-based polymers may have poor processability for forming electrolyte membranes. In such cases, a protecting group may be introduced into the aromatic hydrocarbon-based polymer to temporarily suppress the crystallinity. Specifically, by forming a membrane with the protecting group introduced and then deprotecting the polymer, the crystalline aromatic hydrocarbon-based polymer can be used as a polymer electrolyte in the present invention.

[0054] The first electrolyte membrane may be reinforced with a porous substrate. Examples of the porous substrate include a woven fabric, a nonwoven fabric, a porous film, and a mesh fabric. Examples of the porous substrate include a hydrocarbon-based porous substrate containing a hydrocarbon-based polymer compound as a main component, and a fluorine-based porous substrate containing a fluorine-based polymer compound as a main component.

[0055] Examples of hydrocarbon polymer compounds include polyethylene (PE), polypropylene (PP), polystyrene (PS), polyacrylate, polymethacrylate, polyvinyl chloride (PVC), polyvinylidene chloride (PVdC), polyester, polycarbonate (PC), polysulfone (PSU), polyethersulfone (PES), polyphenylene oxide (PPO), polyarylene ether polymers, polyphenylene sulfide (PPS), polyphenylene sulfide sulfone, polyparaphenylene (PPP), polyarylene polymers, polyarylene ketone, polyether ketone (PEK), polyarylene phosphine oxide, polyether phosphine oxide, polybenzoxazole (PBO), polybenzthiazole (PBT), polybenzimidazole (PBI), polyamide (PA), polyimide (PI), polyetherimide (PEI), and polyimide sulfone (PIS).

[0056] Examples of the fluorine-based polymer compound include polytetrafluoroethylene (PTFE), polyhexafluoropropylene, tetrafluoroethylene-hexafluoropropylene copolymer (FEP), ethylene-tetrafluoroethylene copolymer (ETFE), polyvinylidene fluoride (PVdF), polychlorotrifluoroethylene (PCTFE), perfluoroalkoxy fluorine resin (PFA), and ethylene-chlorotrifluoroethylene copolymer (ECTFE).

[0057] The first electrolyte membrane may contain various additives, such as surfactants, radical scavengers, hydrogen peroxide decomposers, non-electrolytic polymers, elastomers, and fillers, within the range that does not impair the effects of the present invention.

[0058] The thickness of the first electrolyte membrane is suitably about 1 to 1,000 μm, and preferably 5 to 500 μm. When the electrolyte membrane laminate of the present invention is applied to a water electrolysis-type hydrogen generator, the thickness of the first electrolyte membrane is preferably relatively large, specifically, preferably 30 μm or more, more preferably 50 μm or more, and particularly preferably 70 μm or more.

[0059] [First Intermediate Layer] The first intermediate layer contains a polymer electrolyte and particles. The first intermediate layer has a function of increasing the adhesion between the first electrolyte membrane and the second electrolyte membrane, i.e., a function as a bonding layer.

[0060] The first intermediate layer can be formed by laminating an intermediate layer coating liquid, which is a polymer electrolyte solution to which specific particles have been added, on the first electrolyte membrane by a coating method or a transfer method, as described below.

[0061] Examples of the polymer electrolyte contained in the first intermediate layer include the aforementioned hydrocarbon-based polymer electrolyte and fluorine-based polymer electrolyte. Among these, fluorine-based polymer electrolytes are preferred from the viewpoint of enhancing the bonding function.

[0062] In the fluorine-based polymer electrolyte, the fluorine-based polymer means a polymer in which most or all of the hydrogen atoms in the alkyl and / or alkylene groups in the molecule have been substituted with fluorine atoms.

[0063] Examples of fluorine-based polymer electrolytes include perfluorocarbon sulfonic acid-based polymers, perfluorocarbon phosphonic acid-based polymers, trifluorostyrene sulfonic acid-based polymers, trifluorostyrene phosphonic acid-based polymers, ethylene tetrafluoroethylene-g-styrene sulfonic acid-based polymers, ethylene-tetrafluoroethylene copolymers, and polyvinylidene fluoride-perfluorocarbon sulfonic acid-based polymers.

[0064] Among these, perfluorocarbon sulfonic acid polymers are preferred from the viewpoint of heat resistance and chemical stability, and examples of such polymers include commercially available products such as "Nafion" (registered trademark) (manufactured by Chemours), "Flemion" (registered trademark) (manufactured by AGC Inc.), and "Aciplex" (registered trademark) (manufactured by Asahi Kasei Corporation).

[0065] Examples of particles contained in the first intermediate layer include inorganic particles, organic particles, and organic-inorganic composite particles.

[0066] Examples of inorganic particles include carbon particles, silica, titanium oxide, aluminum oxide, zirconium oxide, manganese oxide, cobalt oxide, cerium oxide, yttrium oxide, hafnium oxide, tungsten oxide, silicon nitride, aluminum nitride, silicon carbide, calcium carbonate, zeolite, mica, sericite, kaolin clay, kaolin, mica, talc, and montmorillonite. These inorganic particles may also be metal-supported particles. Examples of such metal-supported particles include carbon particles and silica particles supporting platinum group metals (platinum, ruthenium, rhodium, palladium, osmium, and iridium).

[0067] Examples of the organic particles include various resin particles. Examples of the resin constituting the resin particles include thermoplastic resins and thermosetting resins such as polyethylene resin, polypropylene resin, polyvinyl acetate resin, poly(meth)acrylic resin, polyvinyl chloride resin, polystyrene resin, polycarbonate resin, polyester resin, polyphenylene sulfide resin, polyamide resin, polyimide resin, polyurethane resin, ethylene-(meth)acrylic acid ester copolymer, ABS resin, fluorine resin, epoxy resin, phenol resin, melamine resin, guanamine resin, polyazole resin, polyethersulfone resin, and polyetherketone resin.

[0068] Examples of organic-inorganic composite particles include acrylic-silica composite particles, melamine-silica composite particles, benzoguanamine-silica composite particles, benzoguanamine-melamine-silica composite particles, polystyrene-silica composite particles, silsesquioxane-based organic-inorganic hybrid particles, and organic-coated inorganic nanoparticles.

[0069] The particles contained in the first intermediate layer are thought to function as anchor-forming materials that bond the first intermediate layer to the first electrolyte membrane, and the first intermediate layer to the second electrolyte membrane, respectively, by anchor effect, thereby enhancing the adhesion between the first electrolyte membrane and the second electrolyte membrane. In particular, since the surface of the first electrolyte membrane is relatively smooth, sufficient adhesion may not be obtained if the second electrolyte membrane is laminated directly on the surface of the first electrolyte membrane. However, the interposition of the first intermediate layer solves this adhesion problem.

[0070] Furthermore, among the hydrocarbon-based polymer electrolytes contained in the first electrolyte membrane, the aromatic hydrocarbon-based block copolymer is a highly durable material with relatively high hydrogen generation efficiency and excellent mechanical strength. On the other hand, since it is a material with a relatively high crystallinity, a high elastic modulus, and low solubility, it tends to have low adhesion to the second electrolyte membrane. However, the above-mentioned adhesion problem can be solved by interposing the first intermediate layer.

[0071] From the viewpoint of the anchoring effect, the particles contained in the first intermediate layer preferably have a higher elastic modulus than the hydrocarbon-based polymer electrolyte contained in the first electrolyte membrane. Furthermore, particles having a melting point higher than the glass transition temperature of the carbon-based polymer electrolyte contained in the first electrolyte membrane, or particles that do not melt, are also suitable. Such particles are preferably inorganic particles, high-melting-point thermoplastic resin particles, thermosetting resin particles, or organic-inorganic composite particles, with inorganic particles being particularly preferred.

[0072] Among the inorganic particles described above, carbon particles, metal-supported carbon particles, aluminum oxide particles, zirconium oxide particles, cerium oxide particles, and hafnium oxide particles are preferred because they are relatively stable against acids and alkalis. Carbon particles, aluminum oxide particles, zirconium oxide particles, cerium oxide particles, and hafnium oxide particles are more preferred because they are relatively stable against oxidation-reduction reactions and have excellent chemical durability. Carbon particles, aluminum oxide particles, and zirconium oxide particles are even more preferred because they are relatively inexpensive and easily available. Carbon particles are particularly preferred because they facilitate the formation of a uniform intermediate layer. Examples of carbon particles include carbon black, graphite, activated carbon, carbon nanotubes, carbon nanofibers, and fullerenes. Examples of metal-supported carbon particles include carbon particles supporting metals such as platinum group metals (platinum, ruthenium, rhodium, palladium, osmium, and iridium), iron, lead, gold, silver, copper, chromium, cobalt, nickel, manganese, vanadium, molybdenum, gallium, and aluminum.

[0073] From the viewpoints of dispersibility, film-forming property, and bonding function, the average particle size of the particles is preferably 5 nm or more, more preferably 10 nm or more, and particularly preferably 20 nm or more, and is preferably 1,000 nm or less, more preferably 500 nm or less, and particularly preferably 300 nm or less.

[0074] In the first intermediate layer, the mass ratio of particles to polymer electrolyte (mass of particles / mass of polymer electrolyte) is preferably 0.4 or more, more preferably 0.5 or more, and particularly preferably 0.7 or more. It is also preferably 20.0 or less, more preferably 10.0 or less, and particularly preferably 7.0 or less. By achieving this mass ratio, an intermediate layer excellent in both bonding function and ion conduction resistance can be produced.

[0075] The first intermediate layer may contain various additives, such as surfactants, radical scavengers, hydrogen peroxide decomposers, non-electrolytic polymers, elastomers, etc., within the range that does not impair the effects of the present invention.

[0076] The solids basis weight of the first intermediate layer is 0.05 mg / cm ２ More than 0.1 mg / cm is preferred. ２ More preferably, 0.2 mg / cm or more ２ More preferably, the density is 5.0 mg / cm or more. ２ Preferably, 3.0 mg / cm or less ２ More preferably, 2.0 mg / cm or less ２ The following are particularly preferred: By using the above solid basis weight, an intermediate layer having excellent bonding function and ion conduction resistance can be produced.

[0077] [Second Electrolyte Membrane] The second electrolyte membrane contains a polymer electrolyte and particles containing a transition metal element. The second electrolyte membrane has a function of preventing hydrogen from moving from the cathode to the anode (hydrogen decomposition function). That is, the catalytic action of the particles containing a transition metal element contained in the second electrolyte membrane is utilized to cause hydrogen and oxygen that permeate and diffuse through the electrolyte membrane to react with each other and be removed as water, thereby reducing the hydrogen concentration at the anode.

[0078] The second electrolyte membrane is formed by laminating a coating liquid for the second electrolyte membrane, which is a polymer electrolyte solution to which particles containing a transition metal element have been further added, on the first intermediate layer by a coating method or a transfer method.

[0079] The polymer electrolyte contained in the second electrolyte membrane may be the hydrocarbon-based polymer electrolyte or the fluorine-based polymer electrolyte described above. Among these, the fluorine-based polymer electrolyte is preferred from the viewpoint of adhesion to the catalyst layer described below.

[0080] The transition metal element-containing particles contained in the second electrolyte membrane are preferably particles containing at least one transition metal element selected from platinum, gold, silver, copper, palladium, ruthenium, rhodium, cerium, manganese, iridium, nickel, and cobalt. Furthermore, the transition metal element-containing particles preferably include at least one selected from zero-valent metal particles, metal oxide particles, and sparingly soluble metal salt particles. Specifically, the zero-valent metal particles include simple particles consisting of one of the zero-valent metal elements or alloy particles consisting of multiple metal elements. Examples of metal oxide particles include particles consisting of one selected from gold oxide, silver oxide, copper oxide, palladium oxide, ruthenium oxide, rhodium oxide, cerium oxide, manganese oxide, iridium oxide, nickel oxide, and cobalt oxide, as well as composite particles containing multiple of the oxides. Here, copper oxide can be classified into two types of compounds, copper(I) oxide and copper(II) oxide, depending on the valence of copper, but the term "copper oxide" is used collectively in the present invention. The same applies to other oxides such as ruthenium oxide and manganese oxide, and to the sparingly soluble metal salts described below, such as silver chloride, silver sulfate, silver carbonate, silver phosphate, basic copper carbonate, copper phosphate, palladium sulfate, cerium sulfate, cerium carbonate, cerium phosphate, manganese carbonate, manganese phosphate, iridium chloride, cobalt sulfate, and cobalt phosphate.

[0081] In another preferred embodiment, the transition metal-containing particles are further supported on inorganic particles, organic particles, or organic-inorganic composite particles. In this case, the inorganic particles, organic particles, or organic-inorganic composite particles may be the same as those used in the intermediate layer.

[0082] In the second electrolyte membrane, the mass ratio of the particles containing a transition metal element to the polymer electrolyte (mass of the particles containing a transition metal element / mass of the polymer electrolyte) is preferably 0.01 or more, more preferably 0.03 or more, and particularly preferably 0.05 or more. Also, it is preferably 0.85 or less, more preferably 0.7 or less, and particularly preferably 0.5 or less. Within the above range, an electrolyte membrane laminate having excellent hydrogen barrier properties and ion conduction resistance can be produced.

[0083] The second electrolyte membrane may contain various additives, such as surfactants, radical scavengers, hydrogen peroxide decomposers, non-electrolytic polymers, elastomers, and fillers, within the range that does not impair the effects of the present invention.

[0084] The thickness of the second electrolyte membrane is preferably 0.1 μm or more, more preferably 0.5 μm or more, and particularly preferably 1 μm or more. It is also preferably 20 μm or less, more preferably 10 μm or less, and particularly preferably 7 μm or less. Within the above range, an electrolyte membrane laminate having excellent hydrogen barrier properties and ion conduction resistance can be produced.

[0085] [Third Electrolyte Membrane] In the electrolyte membrane laminate of the present invention, a third electrolyte membrane can be disposed on the second main surface of the first electrolyte membrane. The third electrolyte membrane preferably has a hydrogen decomposition function, similar to the second electrolyte membrane described above. From this viewpoint, the third electrolyte membrane preferably has the same configuration as the second electrolyte membrane. By providing the third electrolyte membrane, the hydrogen barrier property is further improved.

[0086] The third electrolyte membrane is formed by laminating a third electrolyte membrane coating liquid, which is a polymer electrolyte solution to which particles containing a transition metal element have been further added, onto the second main surface of the first electrolyte membrane or the second intermediate layer by a coating method or a transfer method.

[0087] [Second Intermediate Layer] In the electrolyte membrane laminate of the present invention, when a third electrolyte membrane is disposed as described above, a second intermediate layer is preferably provided between the second main surface of the first electrolyte membrane and the third electrolyte membrane. Here, the second intermediate layer preferably functions as a bonding layer, similar to the first intermediate layer described above. From this viewpoint, the second intermediate layer preferably has the same configuration as the first intermediate layer.

[0088] As will be described later, the second intermediate layer is formed by laminating an intermediate layer coating liquid on the second main surface of the first electrolyte membrane by a coating method or a transfer method.

[0089] [Catalyst-Layered Electrolyte Membrane] The electrolyte membrane laminate of the present invention can be formed into a catalyst-layered electrolyte membrane by disposing a catalyst layer on each of its two surfaces. That is, the catalyst-layered electrolyte membrane comprises a catalyst layer on each of the two surfaces of the electrolyte membrane laminate of the present invention (hereinafter sometimes referred to as the "electrolyte membrane laminate"). Specifically, the electrolyte membrane laminate comprises a first catalyst layer on the first main surface of the first electrolyte membrane, and a second catalyst layer on the second main surface of the first electrolyte membrane. Here, it is preferable that the first catalyst layer is an anode catalyst layer and the second catalyst layer is a cathode catalyst layer.

[0090] Preferred embodiments of the catalyst layer-equipped electrolyte membrane of the present invention include the following configurations: i) first catalyst layer (anode catalyst layer) / second electrolyte membrane / first intermediate layer / first electrolyte membrane / second catalyst layer (cathode catalyst layer), and ii) first catalyst layer (anode catalyst layer) / second electrolyte membrane / first intermediate layer / first electrolyte membrane / second intermediate layer / third electrolyte membrane / second catalyst layer (cathode catalyst layer).

[0091] [Catalyst Layer] The catalyst layer is generally a layer containing catalyst particles and a polymer electrolyte. The catalyst layer is formed by laminating a catalyst layer coating liquid, which is a polymer electrolyte solution to which catalyst particles have been added, on the electrolyte membrane laminate of the present invention by a coating method or a transfer method. As the polymer electrolyte, the above-mentioned fluorine-based polymer electrolyte is generally used, and further, from the viewpoints of gas diffusion properties and chemical durability, a perfluorocarbon sulfonic acid-based polymer is preferably used.

[0092] As catalyst particles, generally used are metals such as platinum group elements (platinum, ruthenium, rhodium, palladium, osmium, iridium), iron, lead, gold, silver, copper, chromium, cobalt, nickel, manganese, vanadium, molybdenum, gallium, aluminum, or alloys, oxides, double oxides, etc. Carbon particles carrying the above metals (catalyst-supported carbon particles) are also commonly used. The carbon particles are not particularly limited as long as they are fine particles, electrically conductive, and do not corrode or deteriorate due to reaction with the catalyst, but carbon black, graphite, activated carbon, carbon fiber, carbon nanotubes, and fullerene particles are preferably used.

[0093] The mass ratio of the catalyst particle content to the polymer electrolyte content in the catalyst layer (catalyst particle mass / polymer electrolyte) is generally in the range of 0.5 to 15, preferably 1 or more, more preferably 1.5 or more, and is preferably 13 or less, more preferably 11 or less.

[0094] From the viewpoints of gas diffusibility and durability, the thickness of the catalyst layer is preferably 0.1 μm or more, more preferably 0.5 μm or more, and particularly preferably 1 μm or more, and is preferably 500 μm or less, more preferably 100 μm or less, and particularly preferably 30 μm or less.

[0095] The first catalyst layer (anode catalyst layer) and the second catalyst layer (cathode catalyst layer) may be made of the same material or different materials. When the catalyst-layered electrolyte membrane is applied to a water electrolysis hydrogen generation device, the first catalyst layer (anode catalyst layer) may be made of any catalyst that generates oxygen using water or hydroxide as the catalyst particles, and preferably uses a noble metal such as iridium, ruthenium, rhodium, or palladium, or an oxide thereof. In this case, the catalyst particles may be mixed with an ionomer in the form of a single particle to form a catalyst layer, or may be supported on titanium oxide or the like and mixed with an ionomer to form a catalyst layer. The second catalyst layer (cathode catalyst layer) may be made of any catalyst that generates hydrogen using protons or water as the catalyst particles, and preferably uses platinum-supported carbon particles.

[0096] [Membrane Electrode Assembly] The membrane electrode assembly includes the above-mentioned catalyst-coated electrolyte membrane and gas diffusion layers (gas diffusion electrodes) disposed on both sides thereof. Specifically, the membrane electrode assembly is formed by disposing and joining a first gas diffusion layer (anode gas diffusion layer) on the first catalyst layer (anode catalyst layer) side of the catalyst-coated electrolyte membrane, and a second gas diffusion layer (cathode gas diffusion layer) on the second catalyst layer (cathode catalyst layer) side.

[0097] Gas diffusion layers are generally made of gas-permeable and electron-conductive materials, such as porous carbon and porous metal. Examples of porous carbon materials include carbon paper, carbon cloth, carbon mesh, and carbon nonwoven fabric. Examples of porous metal materials include metal mesh, foam metal, woven metal fabric, sintered metal, and nonwoven metal fabric. Examples of metals include titanium, aluminum and its alloys, nickel and its alloys, copper and its alloys, silver, zinc alloys, lead alloys, niobium, tantalum, iron, stainless steel, gold, and platinum.

[0098] The gas diffusion layer may be subjected to a water-repellent treatment to prevent a decrease in gas diffusion and permeability due to water retention, a partial water-repellent treatment or a partial hydrophilic treatment to form a water drainage path, or the addition of carbon powder to reduce resistance. The gas diffusion layer may also be provided with a conductive intermediate layer containing at least an inorganic conductive material and a hydrophobic polymer on the catalyst-coated electrolyte membrane side. In particular, when the gas diffusion layer is made of a carbon fiber woven fabric or nonwoven fabric with a high porosity, providing a conductive intermediate layer can prevent performance degradation due to the catalyst solution permeating into the gas diffusion layer.

[0099] The thickness of the gas diffusion layer is preferably 50 μm or more, more preferably 100 μm or more, and particularly preferably 150 μm or more, and is preferably 1,000 μm or less, more preferably 700 μm or less, and particularly preferably 500 μm or less.

[0100] The first gas diffusion layer (anode gas diffusion layer) and the second gas diffusion layer (cathode gas diffusion layer) may be made of the same material or different materials. When the membrane electrode assembly is applied to a water electrolysis hydrogen generation device, the first gas diffusion layer (anode gas diffusion layer) and the second gas diffusion layer (cathode gas diffusion layer) are preferably made of different materials. For example, it is preferable that the first gas diffusion layer (anode gas diffusion layer) is made of a porous metal material, and the second gas diffusion layer (cathode gas diffusion layer) is made of a porous carbon material.

[0101] [Methods for Producing Electrolyte Membrane Laminate] Hereinafter, methods for producing an electrolyte membrane laminate will be described, but the present invention is not limited to these methods.

[0102] First, a method for producing the first electrolyte membrane will be described. The first electrolyte membrane can be produced, for example, by applying a polymer electrolyte solution to a membrane-forming substrate and drying it. Examples of the membrane-forming substrate include polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate, polycarbonate, polyetherimide, polyphenylene sulfide, polyimide, polystyrene, polytetrafluoroethylene, polyvinylidene fluoride, ethylene-tetrafluoroethylene copolymers, and perfluoroalkoxy fluororesins. Among these, polyesters are preferred, and polyethylene terephthalate is particularly preferred, from the standpoints of chemical resistance, heat resistance, and cost. The membrane-forming substrate is ultimately peeled off and removed, and may be subjected to a release treatment as necessary. The thickness of the membrane-forming substrate is preferably 30 to 1,000 μm, more preferably 50 to 800 μm, and particularly preferably 100 to 600 μm.

[0103] Examples of the coating method that can be used include knife coating, direct roll coating, Mayer bar coating, gravure coating, reverse coating, air knife coating, spray coating, brush coating, dip coating, die coating, vacuum die coating, curtain coating, flow coating, spin coating, screen printing, and inkjet coating.

[0104] The first electrolyte membrane may be a so-called "composite membrane" reinforced with a porous substrate, and this composite membrane preferably has a polymer electrolyte layer on one or both sides of a porous substrate impregnated with a polymer electrolyte. Examples of a method for producing the composite membrane include a method in which a porous substrate is attached to a polymer electrolyte solution applied to a membrane-forming substrate, and the porous substrate is impregnated with the polymer electrolyte solution, and the polymer electrolyte solution is further applied to the porous substrate and dried.

[0105] The polymer electrolyte may also be one in which the ionic group forms a salt with an alkali metal or alkaline earth metal cation. In this case, after forming the electrolyte membrane or composite membrane on the membrane-forming substrate, it is preferable to perform an acid treatment to exchange the alkali metal or alkaline earth metal cation for a proton. Here, the acid treatment may be performed by a known method.

[0106] The electrolyte membrane laminate of the present invention is produced by laminating a first intermediate layer and a second electrolyte membrane on the first electrolyte membrane produced as described above. The lamination method may be a coating method or a combination of a coating method and a transfer method. For example, the following method may be used. i) a method of sequentially applying a first intermediate layer coating liquid and a second electrolyte membrane coating liquid to a first electrolyte membrane formed on a membrane-forming substrate, and laminating the resulting membrane; ii) a method of applying a first intermediate layer coating liquid to a first electrolyte membrane formed on a membrane-forming substrate, and laminating the resulting membrane, and then laminating the resulting membrane with a second electrolyte membrane by a transfer method; iii) a method of sequentially laminating a first intermediate layer and a second electrolyte membrane by a transfer method to a first electrolyte membrane formed on a membrane-forming substrate; iv) a method of laminating a first intermediate layer by a transfer method to a first electrolyte membrane formed on a membrane-forming substrate, and then laminating the resulting membrane with a second electrolyte membrane coating liquid; v) a method of laminating a laminate of a first intermediate layer and a second electrolyte membrane by a transfer method to a first electrolyte membrane formed on a support.

[0107] The transfer methods in ii) to v) above involve preparing a transfer sheet T1 in which a second electrolyte membrane is laminated on a support, and / or a transfer sheet T2 in which a first intermediate layer is laminated on a support, or a transfer sheet T3 in which a second electrolyte membrane and a first intermediate layer are laminated in that order on a support, and in ii) above, the first intermediate layer is brought into contact with the second electrolyte membrane of the transfer sheet T1 to transfer the second electrolyte membrane onto the first intermediate layer, and in iii) above, the first electrolyte membrane is brought into contact with the first intermediate layer of the transfer sheet T2 to transfer the first intermediate layer onto the first electrolyte membrane, and then The first intermediate layer is then brought into contact with the second electrolyte membrane of the transfer sheet T1, and the second electrolyte membrane is transferred onto the first intermediate layer. The second intermediate layer is then transferred onto the first electrolyte membrane by contacting the first intermediate layer of the transfer sheet T2 with the first electrolyte membrane, and the second electrolyte membrane coating liquid is then applied to the exposed support-side surface of the first intermediate layer by peeling off the support. The second intermediate layer is then transferred onto the exposed support-side surface of the first intermediate layer by peeling off the support. The second electrolyte membrane coating liquid is then applied to the exposed support-side surface of the first intermediate layer by contacting the first electrolyte membrane with the first intermediate layer of the transfer sheet. The first intermediate layer and the second electrolyte membrane can be transferred onto the first electrolyte membrane by contacting the first intermediate layer of the transfer sheet with the first intermediate layer. The first intermediate layer and the second electrolyte membrane can be formed using the same plastic films as those used for the membrane-forming substrates.

[0108] The above manufacturing method is an example of a method for manufacturing a "laminated body 1" in which a first intermediate layer and a second electrolyte membrane are laminated on a first main surface of a first electrolyte membrane, but in the case of a "laminated body 2" in which a second intermediate layer and a third electrolyte membrane are laminated on a second main surface of a first electrolyte membrane, the membrane-forming substrate can be peeled off from the laminate 1 with membrane-forming substrate obtained in i) to iv) above, and the second intermediate layer and the third electrolyte membrane can be laminated on the peeled surface (the second main surface of the first electrolyte membrane) in the same manner as in i) to iv) above.

[0109] Another suitable method is to peel off the membrane-forming substrate from the laminate 1 with the membrane-forming substrate, expose the first and second main surfaces of the first electrolyte membrane, and then simultaneously or sequentially apply the same methods as i) to iv) above to both surfaces of the first electrolyte membrane, thereby obtaining a "laminated body 2" in which the first intermediate layer and the second electrolyte membrane are sequentially laminated on the first main surface and the second intermediate layer and the third electrolyte membrane are sequentially laminated on the second main surface.

[0110] In the method for producing the laminate 2, before or after peeling the membrane-forming substrate from the membrane-forming substrate-attached laminate 1 and before laminating the second intermediate layer, another support can be laminated on the second electrolyte membrane side of the laminate 1 to reinforce the laminate 1. As the another support, a plastic film similar to the above-mentioned membrane-forming substrate can be used.

[0111] [Method for manufacturing a catalyst layer-coated electrolyte membrane] Examples of methods for laminating a catalyst layer on the electrolyte membrane laminate of the present invention include a coating method, a transfer method, or a combination of a coating method and a transfer method. These methods are not particularly limited, and known methods can be used.

[0112] As a coating method, the catalyst layer coating liquid can be applied to the electrolyte membrane laminate using the coating method described above. Specifically, a method can be used in which the first catalyst layer coating liquid is applied to the second electrolyte membrane side of the electrolyte membrane laminate and dried to form an anode catalyst layer, and the second catalyst layer coating liquid is applied to the opposite side of the electrolyte membrane laminate and dried to form a cathode catalyst layer. The lamination order of the anode catalyst layer and the cathode catalyst layer may be reversed. When using the coating method, it is preferable to laminate a membrane-forming substrate on the side of the electrolyte membrane laminate opposite to the side to which the catalyst layer coating liquid is applied. Hereinafter, the first catalyst layer may be referred to as the anode catalyst layer, and the second catalyst layer may be referred to as the cathode catalyst layer.

[0113] The transfer method may be a method in which an anode catalyst layer transfer sheet (anode catalyst decal) in which an anode catalyst layer is laminated on a support and a cathode catalyst layer transfer sheet (cathode catalyst decal) in which a cathode catalyst layer is laminated on a support are prepared, the anode catalyst layer transfer sheet is laminated on the second electrolyte membrane side of the electrolyte membrane laminate, and the cathode catalyst layer transfer sheet is laminated on the opposite side of the electrolyte membrane laminate, and the resulting sheets are heat-pressed to transfer the anode catalyst layer and the cathode catalyst layer, respectively. The support may be a plastic film similar to the support described above.

[0114] An example of a combined use of the coating method and the transfer method is a method in which the coating liquid for the anode catalyst layer is first applied to the second electrolyte membrane side of the electrolyte membrane laminate and dried to form the anode catalyst layer, and then a cathode catalyst layer transfer sheet is attached to the opposite side of the electrolyte membrane laminate and hot-pressed to transfer the cathode catalyst layer. Conversely to the above, a method in which the coating liquid for the cathode catalyst layer is applied and then the anode catalyst layer is transferred may also be used.

[0115] [Combined Manufacturing Method of Electrolyte Membrane Stack and Catalyst-Coated Electrolyte Membrane] The combined manufacturing method is a manufacturing method in which an electrolyte membrane stack is completed during the manufacturing process of a catalyst-coated electrolyte membrane. A manufacturing method for one form of a catalyst-coated electrolyte membrane, "first catalyst layer (anode catalyst layer) / second electrolyte membrane / first intermediate layer / first electrolyte membrane / second catalyst layer (cathode catalyst layer)," will be described. For example, the following manufacturing method (hereinafter referred to as "first manufacturing method") can be exemplified as such a manufacturing method.

[0116] That is, a laminate (L) in which a first intermediate layer is laminated on a first electrolyte membrane, and a first catalyst layer transfer sheet (T) in which a first catalyst layer and a second electrolyte membrane are laminated in this order on a first support are laminated on a second support. Ｃ１ ) and a second catalyst layer transfer sheet (T Ｃ２ ) and the first intermediate layer of the laminate (L) and the first catalyst layer transfer sheet (T Ｃ１ ) is brought into contact with the second electrolyte membrane of the laminate (L), and the first electrolyte membrane of the laminate (L) and the second catalyst layer transfer sheet (T Ｃ２ ) is brought into contact with a second catalyst layer of the catalyst layer.

[0117] Here, methods for laminating the first intermediate layer on the first electrolyte membrane include a method in which the first intermediate layer coating liquid is directly applied to the first electrolyte membrane and then dried, and a method in which the first intermediate layer coating liquid is applied to a support and dried to form an intermediate layer transfer sheet, and then the first electrolyte membrane and the first intermediate layer of the intermediate layer transfer sheet are brought into contact with each other and transferred, and either method can be suitably used.

[0118] In the first manufacturing method, the first catalyst layer transfer sheet (T Ｃ１ ) and the second catalyst layer transfer sheet (TＣ２ ) is brought into contact with the catalyst layer (sometimes referred to as the "transfer step"), thermocompression bonding is preferably performed. The heating temperature during thermocompression bonding is preferably 50°C or higher, more preferably 70°C or higher, and even more preferably 100°C or higher. The heating temperature is preferably 220°C or lower, more preferably 200°C or lower, and even more preferably 180°C or lower. The pressure is preferably 1 MPa or higher, and more preferably 2 MPa or higher. The pressure is preferably 20 MPa or lower, and more preferably 10 MPa or lower. By performing thermocompression bonding under conditions within the above preferred ranges, a catalyst-layered electrolyte membrane having high water electrolysis performance and durability can be obtained.

[0119] In the first manufacturing method, the laminate (L), the first catalyst layer transfer sheet (T Ｃ１ ) and a second catalyst layer transfer sheet (T Ｃ２ ) are preferably supplied in the form of a long roll, and the catalyst layer-equipped electrolyte membrane is preferably manufactured as a long roll. That is, at least the above-mentioned transfer step is preferably carried out by a roll-to-roll method. Here, the roll-to-roll method is a method in which each member is supplied in the form of a long roll, and each is continuously unwound and transported to carry out the transfer step, and the obtained catalyst layer-equipped electrolyte membrane is wound up in the form of a long roll. Ｃ１ ) support and the second catalyst layer transfer sheet (T Ｃ２ The supports (a) and (b) may be peeled off before the catalyst layer-equipped electrolyte membrane is wound up into a roll, or may be wound up together with the catalyst layer-equipped electrolyte membrane without being peeled off, or one may be peeled off and the other may be wound up together with the catalyst layer-equipped electrolyte membrane.

[0120] The laminate (L) can be produced as a membrane-forming substrate-attached laminate L by laminating a first intermediate layer on a first electrolyte membrane formed on a membrane-forming substrate. Details are as described in the above-mentioned method for producing an electrolyte membrane laminate. When using the membrane-forming substrate-attached laminate (L), it is necessary to carry out a transfer step after peeling the membrane-forming substrate from the membrane-forming substrate-attached laminate (L).

[0121] Next, a method for producing another form of catalyst-layered electrolyte membrane, namely, "first catalyst layer (anode catalyst layer) / second electrolyte membrane / first intermediate layer / first electrolyte membrane / second intermediate layer / third electrolyte membrane / second catalyst layer (cathode catalyst layer)" will be described. For example, the following production method (hereinafter referred to as "second production method") can be exemplified as such a production method.

[0122] That is, a laminate (L) in which a first intermediate layer is laminated on a first electrolyte membrane, and a first catalyst layer transfer sheet (T) in which a first catalyst layer and a second electrolyte membrane are laminated in this order on a first support are laminated on a second support. Ｃ１ ), and a second catalyst layer transfer sheet (T Ｃ３ ) and the first intermediate layer of the laminate (L) and the first catalyst layer transfer sheet (T Ｃ１ ) is brought into contact with the second electrolyte membrane of the laminate (L), and the first electrolyte membrane of the laminate (L) and the second catalyst layer transfer sheet (T Ｃ３ ) is brought into contact with a second intermediate layer.

[0123] In the second manufacturing method, the first catalyst layer transfer sheet (T Ｃ１ ) and the second catalyst layer transfer sheet (T Ｃ３ In the step of bringing the two layers into contact (sometimes referred to as the "transfer step"), thermocompression bonding is preferably performed. The thermocompression bonding conditions are the same as those in the first manufacturing method. Other manufacturing conditions may also be the same as those in the first manufacturing method.

[0124] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these examples. The various measurement conditions are as follows.

[0125] (1) Molecular Weight of Polymer The number average molecular weight and weight average molecular weight of the polymer solution were measured by GPC. An HLC-8022 GPC manufactured by Tosoh Corporation was used as an integrated device combining an ultraviolet detector and a differential refractometer. Two TSK gel Super HM-H GPC columns (inner diameter 6.0 mm, length 15 cm) manufactured by Tosoh Corporation were used. Measurements were performed in N-methyl-2-pyrrolidone solvent (N-methyl-2-pyrrolidone solvent containing 10 mmol / L of lithium bromide) at a flow rate of 0.2 mL / min, and the number average molecular weight and weight average molecular weight were calculated in terms of standard polystyrene.

[0126] (2) Ion exchange capacity (IEC) was measured by neutralization titration. The measurement was carried out three times and the average value was calculated.

[0127] After the proton substitution and thorough washing with pure water, the moisture on the surface of the electrolyte membrane was wiped off, and the membrane was then vacuum dried at 100° C. for 12 hours or more, and the dry weight was determined.

[0128] 50 mL of a 5% by mass aqueous solution of sodium sulfate was added to the electrolyte membrane, and the membrane was allowed to stand for 12 hours to carry out ion exchange.

[0129] The resulting sulfuric acid was titrated with 0.01 mol / L aqueous sodium hydroxide solution. 0.1 w / v % commercially available phenolphthalein solution for titration was added as an indicator, and the point at which the color turned pale reddish purple was defined as the endpoint.

[0130] The ion exchange capacity (IEC) was calculated by the following formula.

[0131] IEC (meq / g) = [concentration of aqueous sodium hydroxide solution (mmol / mL) x amount dropped (mL)] / dry weight of sample (g).

[0132] (3) Observation of phase separation structure by transmission electron microscope (TEM) tomography A sample piece of the electrolyte membrane was immersed in a 2% by mass aqueous solution of lead acetate as a staining agent and left to stand at 25°C for 48 hours for staining treatment. The stained sample was removed, embedded in epoxy resin, and fixed by irradiating with visible light for 30 seconds. A 100 nm thin section was cut using an ultramicrotome at room temperature and observed under the following conditions.

[0133] Equipment: Field Emission Electron Microscope (HRTEM) JEM2100F (JEOL Ltd.) Image Acquisition: Digital Micrograph System: Marker Method Acceleration Voltage: 200 kV Magnification: 30,000x Tilt Angle: +61° to -62° Reconstruction Resolution: 0.71 nm / pixel 3D reconstruction processing was performed using the marker method. Au colloidal particles attached to a collodion film were used as alignment markers for 3D reconstruction. Using the markers as a reference, the sample was tilted in 1° increments in the range of +61° to -62°, and TEM images were taken. CT reconstruction processing was performed based on a total of 124 TEM images obtained from a series of sequential tilt images, and the 3D phase separation structure was observed.

[0134] (4) Evaluation of interlayer adhesion (peelability) The catalyst-coated electrolyte membranes prepared in the examples and comparative examples were cut into test pieces measuring 2 cm x 2 cm. These test pieces were immersed in 20 g of ion-exchanged water at 23°C and allowed to stand for 16 hours, after which they were observed for the occurrence of interlayer delamination and evaluated according to the following criteria: Good: no interlayer delamination occurred; Poor: interlayer delamination occurred.

[0135] (5) Evaluation of water electrolysis performance and hydrogen barrier property To evaluate the hydrogen barrier property (hydrogen decomposition performance) of the electrolyte membrane laminate, a membrane electrode assembly (MEA) using the electrolyte membrane laminate and the catalyst layer-equipped electrolyte membrane was produced as follows.

[0136] A commercially available gas diffusion electrode (SGL 24BCH) was cut into a 5 cm square to serve as a cathode gas diffusion electrode. A commercially available porous titanium sintered plate was cut into a 5 cm square to serve as an anode gas diffusion electrode. An MEA was fabricated by sandwiching a catalyst-coated electrolyte membrane between the cathode gas diffusion electrode and the anode gas diffusion electrode.

[0137] [Evaluation of Water Electrolysis Performance] The MEA prepared above was placed in a JARI standard cell "Ex-1" (electrode area 25 cm) manufactured by Eiwa Co., Ltd. ２ ) and the cell temperature was set to 80°C. Deionized water with an electrical conductivity of 1 μS / cm or less was supplied to both the cathode and anode electrodes at a flow rate of 0.2 L / min at atmospheric pressure, and a current of 2 A / cm ２A current of 100 kJ / s was applied to the cell to produce hydrogen gas and oxygen gas through a water electrolysis reaction. The voltage applied to the cell at this time was taken as the water electrolysis performance.

[0138] [Measurement of Hydrogen Gas Concentration in Oxygen Gas] After removing water from the generated oxygen gas discharged from the anode in the above-described water electrolysis performance evaluation, the gas was introduced into a gas chromatography analyzer, and the hydrogen gas concentration (ppm, volume ratio) in the oxygen gas was measured under the following conditions.

[0139] Apparatus: 490 Micro GC, manufactured by Agilent Technologies, Inc. Column: Agilent Technologies, Inc., Part No. 493001360, Type BF CHA 10 m MS5A Unl, Facl Carrier gas: Ar Column temperature: 100°C.

[0140] (6) Chemical durability evaluation After the evaluation of water electrolysis performance and hydrogen barrier property, durability was evaluated using the same device and cell. At this time, at a cell temperature of 50°C, a current of 1.0 A / cm ２ The time required for the water electrolysis voltage to reach 1.9 V was taken as the electrolysis performance retention time and used as an index for durability evaluation.

[0141] Synthesis Example 1 (Synthesis of 2,2-bis(4-hydroxyphenyl)-1,3-dioxolane (K-DHBP) represented by the following chemical formula (G1)) A 500 mL flask equipped with a stirrer, thermometer, and distillation tube was charged with 49.5 g of 4,4'-dihydroxybenzophenone, 134 g of ethylene glycol, 96.9 g of trimethyl orthoformate, and 0.50 g of p-toluenesulfonic acid monohydrate, and dissolved therein. The mixture was then stirred and kept at 78 to 82°C for 2 hours. The internal temperature was then gradually raised to 120°C, and the mixture was heated until the distillation of methyl formate, methanol, and trimethyl orthoformate completely stopped. After cooling this reaction solution to room temperature, the reaction solution was diluted with ethyl acetate, and the organic layer was washed with 100 mL of a 5% aqueous potassium carbonate solution and separated, followed by distilling off the solvent. 80 mL of dichloromethane was added to the residue to precipitate crystals, which were filtered and dried to obtain 52.0 g of 2,2-bis(4-hydroxyphenyl)-1,3-dioxolane represented by the following chemical formula (G1). GC analysis of the crystals revealed that they were 99.9% 2,2-bis(4-hydroxyphenyl)-1,3-dioxolane and 0.1% 4,4'-dihydroxybenzophenone. The purity was 99.9%.

[0142]

[0143] Synthesis Example 2 (Synthesis of disodium-3,3'-disulfonate-4,4'-difluorobenzophenone represented by the following chemical formula (G2)) 109.1 g of 4,4'-difluorobenzophenone (Sigma-Aldrich Japan (same) reagent) was dissolved in fuming sulfuric acid (50% SO ３ The resulting mixture was reacted at 100°C for 10 hours in 150 mL of ethanol (Fujifilm Wako Pure Chemical Industries, Ltd., reagent). The mixture was then poured little by little into a large amount of water, neutralized with NaOH, and 200 g of table salt (NaCl) was added to precipitate the synthesized product. The resulting precipitate was filtered and recrystallized with an aqueous ethanol solution to obtain disodium-3,3'-disulfonate-4,4'-difluorobenzophenone represented by the following chemical formula (G2). The purity was 99.3%.

[0144]

[0145] Synthesis Example 3 (Synthesis of nonionic oligomer a1 represented by the following general formula (G3)) 16.59 g of potassium carbonate (Aldrich reagent, 120 mmol), 25.83 g (100 mmol) of K-DHBP obtained in Synthesis Example 1, and 20.3 g of 4,4'-difluorobenzophenone (Aldrich reagent, 93 mmol) were placed in a 2,000 mL SUS polymerization reactor equipped with a stirrer, a nitrogen inlet tube, and a Dean-Stark trap. After nitrogen substitution, 300 mL of N-methylpyrrolidone (NMP) and 100 mL of toluene were added, and the mixture was dehydrated at 150°C. The temperature was then raised to remove the toluene, and polymerization was carried out at 170°C for 3 hours. Purification by reprecipitation with a large amount of methanol yielded a terminal hydroxyl form of nonionic oligomer a1. The number average molecular weight of the terminal hydroxyl form of this nonionic oligomer a1 was 10,000.

[0146] A 500 mL three-neck flask equipped with a stirrer, nitrogen inlet tube, and Dean-Stark trap was charged with 1.1 g of potassium carbonate (Sigma-Aldrich Japan (same) reagent, 8 mmol) and 20.0 g (2 mmol) of the terminal hydroxy compound of the above nonionic oligomer a1. After replacing the atmosphere inside the flask with nitrogen, 100 mL of NMP and 30 mL of toluene were added, and the mixture was dehydrated at 100°C and then heated to remove the toluene. Furthermore, 2.2 g of hexafluorobenzene (Sigma-Aldrich Japan (same) reagent, 12 mmol) was added, and the reaction was carried out at 105°C for 12 hours. Purification was carried out by reprecipitation with a large amount of isopropyl alcohol, yielding nonionic oligomer a1 (terminal: fluoro group) represented by the following general formula (G3). The number average molecular weight was 11,000.

[0147]

[0148] Synthesis Example 4 (Synthesis of ionic oligomer a2 represented by the following general formula (G4)) 27.6 g of potassium carbonate (Sigma-Aldrich Japan (same manufacturer), reagent, 200 mmol), 12.9 g (50 mmol) of K-DHBP obtained in Synthesis Example 1, 9.3 g of 4,4'-biphenol (Sigma-Aldrich Japan (same manufacturer), reagent, 50 mmol), 39.3 g (93 mmol) of disodium-3,3'-disulfonate-4,4'-difluorobenzophenone obtained in Synthesis Example 2, and 17.9 g of 18-crown-6 (Fujifilm Wako Pure Chemical Industries, Ltd., 82 mmol) were placed in a 2,000 mL SUS polymerization reactor equipped with a stirrer, a nitrogen inlet tube, and a Dean-Stark trap. After nitrogen substitution, 300 mL of NMP and 100 mL of toluene were added, and the mixture was dehydrated at 150°C, heated to remove the toluene, and then polymerized at 170°C for 6 hours. Purification by reprecipitation with a large amount of isopropyl alcohol gave an ionic oligomer a2 (terminal: hydroxy group) represented by the following general formula (G4), having a number average molecular weight of 16,000.

[0149]

[0150] (In general formula (G4), M represents H, Na, or K.) [Synthesis Example 5] (Synthesis of neopentyl 3-(2,5-dichlorobenzoyl)benzenesulfonate represented by the following chemical formula (G5)) 245 g (2.1 mol) of chlorosulfonic acid was placed in a 3 L three-neck flask equipped with a stirrer and a condenser, followed by the addition of 105 g (420 mmol) of 2,5-dichlorobenzophenone, and the mixture was reacted for 8 hours in an oil bath at 100°C. After the predetermined time, the reaction solution was slowly poured into 1,000 g of crushed ice and extracted with ethyl acetate. The organic layer was washed with brine and dried over magnesium sulfate, and the ethyl acetate was then distilled off to obtain pale yellow crude crystals of 3-(2,5-dichlorobenzoyl)benzenesulfonyl chloride. The crude crystals were used directly in the next step without purification.

[0151] 41.1 g (462 mmol) of 2,2-dimethyl-1-propanol (neopentyl alcohol) was added to 300 mL of pyridine and cooled to approximately 10°C. The crude crystals obtained above were gradually added over approximately 30 minutes. After the entire amount was added, the mixture was stirred for an additional 30 minutes to allow the reaction to proceed. After the reaction, the reaction solution was poured into 1,000 mL of aqueous hydrochloric acid, and the precipitated solid was collected. The resulting solid was dissolved in ethyl acetate, washed with aqueous sodium bicarbonate and brine, dried over magnesium sulfate, and the ethyl acetate was distilled off to obtain crude crystals. These were recrystallized from methanol to obtain white crystals of neopentyl 3-(2,5-dichlorobenzoyl)benzenesulfonate, represented by the following chemical formula (G5).

[0152]

[0153] Synthesis Example 6 (Synthesis of an oligomer not containing an ionic group represented by the following general formula (G6)) 49.4 g (0.29 mol) of 2,6-dichlorobenzonitrile, 88.4 g (0.26 mol) of 2,2-bis(4-hydroxyphenyl)-1,1,1,3,3,3-hexafluoropropane, and 47.3 g (0.34 mol) of potassium carbonate were weighed into a 1 L three-necked flask equipped with a stirrer, thermometer, condenser, Dean-Stark tube, and a three-way stopcock for nitrogen introduction. After purging with nitrogen, 346 mL of sulfolane and 173 mL of toluene were added and stirred. The flask was placed in an oil bath and heated to reflux at 150°C. The water produced by the reaction was azeotroped with toluene and the reaction was continued while being removed from the system using a Dean-Stark tube. After approximately 3 hours, almost no water was produced. After removing most of the toluene while gradually increasing the reaction temperature, the reaction was continued for 3 hours at 200° C. Next, 12.3 g (0.072 mol) of 2,6-dichlorobenzonitrile was added, and the reaction was continued for another 5 hours.

[0154] The resulting reaction solution was allowed to cool and then diluted with 100 mL of toluene. The precipitated inorganic compound by-product was removed by filtration, and the filtrate was poured into 2 L of methanol. The precipitated product was filtered, collected, dried, and then dissolved in 250 mL of tetrahydrofuran. This was reprecipitated in 2 L of methanol to obtain 107 g of the target oligomer represented by the following general formula (G6). The number average molecular weight was 11,000.

[0155]

[0156] Synthesis Example 7 (Synthesis of polyethersulfone (PES)-based block copolymer precursor b4′ composed of a segment represented by the following chemical formula (G8) and a segment represented by the following general formula (G9)) 1.62 g of anhydrous nickel chloride and 15 mL of dimethyl sulfoxide were mixed and adjusted to 70° C. 2.15 g of 2,2′-bipyridyl was added thereto and stirred at the same temperature for 10 minutes to prepare a nickel-containing solution.

[0157] To this solution, 1.49 g of 2,5-dichlorobenzenesulfonic acid (2,2-dimethylpropyl) and 0.50 g of Sumikaexcel PES5200P (manufactured by Sumitomo Chemical Co., Ltd., Mn = 40,000, Mw = 94,000), represented by the following general formula (G7), were dissolved in 5 mL of dimethyl sulfoxide. 1.23 g of zinc powder was added and the temperature was adjusted to 70°C. The nickel-containing solution was poured into this solution, and a polymerization reaction was carried out at 70°C for 4 hours. The reaction mixture was added to 60 mL of methanol, and then 60 mL of 6 mol / L hydrochloric acid was added and stirred for 1 hour. The precipitated solid was separated by filtration and dried to obtain 1.62 g of a grayish-white block copolymer precursor b4' containing segments represented by the following general formula (G8) and the following general formula (G9), in a yield of 99%. The weight-average molecular weight was 230,000.

[0158]

[0159]

[0160]

[0161] [First electrolyte membrane coating liquid P1] Polymer electrolyte solution composed of block copolymer C1 containing oligomer a2 as an ionic segment and oligomer a1 as a nonionic segment. 16 g of ionic oligomer a2 and 11 g of nonionic oligomer a1 were placed in a 2,000 mL SUS polymerization reactor equipped with a stirrer, a nitrogen inlet tube, and a Dean-Stark trap, and NMP was added so that the total amount of the oligomers charged was 7 wt %, followed by reaction at 105° C. for 24 hours.

[0162] Reprecipitation was carried out in a large amount of an isopropyl alcohol / NMP mixed solution (weight ratio 2 / 1), and the resulting precipitate was collected by filtration and washed with a large amount of isopropyl alcohol block to obtain copolymer P1. The weight average molecular weight was 340,000. The ion exchange capacity (IEC) of this block copolymer P1 was 2.1 meq / g. Next, block copolymer P1 was dissolved in NMP and pressure filtered using a 1 μm polypropylene filter to obtain polymer electrolyte solution P1 (polymer electrolyte concentration 13% by mass) as a coating liquid for the first electrolyte membrane. The viscosity of polymer electrolyte solution P1 was 1,300 mPa s.

[0163] [First electrolyte membrane coating liquid P2] Polymer electrolyte solution composed of random copolymer C2

[0049] 129 g of 2,2-bis(4-hydroxyphenyl)-1,3-dioxolane synthesized in Synthesis Example 1, 93 g of 4,4'-biphenol (Sigma-Aldrich Japan (same reagent)), and 422 g (1.0 mol) of disodium-3,3'-disulfonate-4,4'-difluorobenzophenone synthesized in Synthesis Example 2 were placed in a 5 L reaction vessel equipped with a stirrer, a nitrogen inlet tube, and a Dean-Stark trap. After purging with nitrogen, the solution was diluted with NMP. 3,000 g of ethanol, 450 g of toluene, and 232 g of 18-crown-6 (reagent, Fujifilm Wako Pure Chemical Industries, Ltd.) were added, and after confirming that all the monomers had dissolved, 304 g of potassium carbonate (reagent, Sigma-Aldrich Japan, same manufacturer) was added, and the mixture was dehydrated at 160°C under reflux, then heated to remove toluene, and desalting polycondensation was carried out at 200°C for 1 hour. The weight-average molecular weight of the resulting random copolymer C2 was 320,000, and the ion exchange capacity (IEC) was 2.1.

[0164] Next, NMP was added to dilute the polymerization stock solution to a viscosity of 500 mPa s. An angle rotor RA-800 was installed in a Kubota Manufacturing Co., Ltd. inverter compact high-speed refrigerated centrifuge (model number 6930), and the polymerization stock solution was directly centrifuged at 25 ° C. for 30 minutes at a centrifugal force of 20,000 G. The precipitated solids (cake) and the supernatant (coating solution) were separated cleanly, and the supernatant was recovered. Next, the mixture was distilled under reduced pressure at 80 ° C. with stirring, and NMP was removed until the polymer concentration reached 14% by mass. The mixture was then pressure-filtered through a 5 μm polyethylene filter to obtain polymer electrolyte solution P2, which was used as the first electrolyte membrane coating solution. The viscosity of this polymer electrolyte solution P2 was 1,000 mPa s.

[0165] [First electrolyte membrane coating liquid P3] Polymer electrolyte solution comprising polyarylene block copolymer C3 represented by the following general formula (G10): 540 mL of dried N,N-dimethylacetamide (DMAc) was added under nitrogen to a mixture of 135.0 g (0.336 mol) of neopentyl 3-(2,5-dichlorobenzoyl)benzenesulfonate, 40.7 g (5.6 mmol) of the nonionic oligomer represented by general formula (G6) synthesized in Synthesis Example 6, 6.71 g (16.8 mmol) of 2,5-dichloro-4'-(1-imidazolyl)benzophenone, 6.71 g (10.3 mmol) of bis(triphenylphosphine)nickel dichloride, 35.9 g (0.137 mol) of triphenylphosphine, 1.54 g (10.3 mmol) of sodium iodide, and 53.7 g (0.821 mol) of zinc.

[0166] The reaction system was heated with stirring (finally heated to 79°C) and reacted for 3 hours. An increase in viscosity in the system was observed during the reaction. The polymerization reaction solution was diluted with 730 mL of DMAc, stirred for 30 minutes, and filtered using Celite as a filter aid.

[0167] The filtrate was concentrated using an evaporator, and 43.8 g (0.505 mol) of lithium bromide was added to the filtrate. The mixture was reacted at an internal temperature of 110°C for 7 hours under a nitrogen atmosphere. After the reaction, the mixture was cooled to room temperature and poured into 4 L of acetone to coagulate. The coagulated product was collected by filtration, air-dried, pulverized in a mixer, and washed with 1,500 mL of 1N hydrochloric acid while stirring. After filtration, the product was washed with ion-exchanged water until the pH of the washings reached 5 or higher, and then dried overnight at 80°C to obtain 23.0 g of polyarylene-based block copolymer C3. The weight-average molecular weight of this deprotected polyarylene-based block copolymer C3 was 190,000, and the ion exchange capacity (IEC) was 2.0. The obtained polyarylene-based block copolymer C3 was dissolved in a mixed organic solvent of N-methyl-2-pyrrolidone / methanol = 30 / 70 (mass%) to a concentration of 0.1 g / g to obtain polymer electrolyte solution P3, which would serve as a coating liquid for a first electrolyte membrane. The viscosity of the polymer electrolyte solution P3 was 1,200 mPa·s.

[0168]

[0169] [First Electrolyte Membrane Coating Liquid P4] Polymer Electrolyte Solution Composed of Polyethersulfone-Based Block Copolymer C4 0.23 g of the block copolymer precursor b4' obtained in Synthesis Example 7 was weighed and added to a mixed solution of 0.16 g of lithium bromide monohydrate and 8 mL of NMP, and the mixture was allowed to react at 120°C for 24 hours. The reaction mixture was poured into 80 mL of 6 mol / L hydrochloric acid and stirred for 1 hour. The precipitated solid was separated by filtration. The separated solid was dried to obtain a gray-white block copolymer C4 composed of a segment represented by the general formula (G9) and a segment represented by the following chemical formula (G11). The resulting polyethersulfone-based block copolymer C4 had a weight-average molecular weight of 190,000 and an ion exchange capacity (IEC) of 2.0. The resulting polyethersulfone-based block copolymer C4 was dissolved in an organic solvent (N-methyl-2-pyrrolidone / methanol = 30 / 70 (mass%)) to a concentration of 0.1 g / g, to obtain polymer electrolyte solution P4, which would serve as a first electrolyte membrane coating liquid. The viscosity of the polymer electrolyte solution P4 was 1,300 mPa·s.

[0170]

[0171] [First intermediate layer coating liquid E] Platinum catalyst-supported carbon particles TEC10V60TPM (platinum loading rate 60 mass%) manufactured by Tanaka Kikinzoku Kogyo K.K. and D2020 "Nafion" (registered trademark) dispersion manufactured by Chemours Corporation were mixed so that the mass ratio of platinum catalyst-supported carbon particles: "Nafion" (registered trademark) was 3:1. This first intermediate layer coating liquid E was also used as the second intermediate layer coating liquid.

[0172] [First Intermediate Layer Coating Liquid F] First intermediate layer coating liquid F was prepared in the same manner as first intermediate layer coating liquid E, except that carbon particles manufactured by Cabot Corporation, "VULCAN" (registered trademark) XC72, were used instead of TEC10V60TPM, and the mass ratio of carbon particles to "Nafion" (registered trademark) was set to 1.2:1.

[0173] [First Intermediate Layer Coating Liquid G] First intermediate layer coating liquid G was prepared in the same manner as first intermediate layer coating liquid F, except that block copolymer C1 was used instead of "Nafion" (registered trademark).

[0174] [Coating Solution H for Anode Catalyst Layer] IrO manufactured by Umicore was used instead of TEC10V60TPM. ２ Using the catalyst Elyst Ir75 0480 (Ir content 75%), IrO ２ Anode catalyst layer coating solution H was prepared in the same manner as first intermediate layer coating solution E, except that the mass ratio of catalyst:Nafion (registered trademark) was 10:1.

[0175] [Coating Liquid I for Cathode Catalyst Layer] Coating Liquid I for a cathode catalyst layer was prepared in the same manner as for the first intermediate layer coating liquid E, except that platinum catalyst-supported carbon particles TEC10E50E (platinum loading rate: 50 mass%) manufactured by Tanaka Kikinzoku Kogyo K.K. were used instead of TEC10V60TPM, and the mass ratio of platinum catalyst-supported carbon particles:Nafion was set to 2:1.

[0176] [Coating Liquid J for Second Electrolyte Membrane] Coating Liquid J for a second electrolyte membrane was prepared in the same manner as for Coating Liquid E for the first intermediate layer, except that platinum nanoparticles (average particle size 200 nm) manufactured by Sigma-Aldrich Japan (same company) were used instead of TEC10V60TPM, and the mass ratio of platinum nanoparticles to "Nafion" (registered trademark) was set to 0.1:1. This Coating Liquid J for a second electrolyte membrane was also used as the coating liquid for a third electrolyte membrane.

[0177] [First intermediate layer coating liquid K] First intermediate layer coating liquid K was prepared in the same manner as first intermediate layer coating liquid E, except that palladium-activated carbon (palladium loading rate: 10 mass%) manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. was used instead of TEC10V60TPM, and the mass ratio of palladium-loaded carbon particles: "Nafion" was set to 1.33:1.

[0178] [Coating Liquid L for Second Electrolyte Membrane] D2020 "Nafion" (registered trademark) dispersion liquid manufactured by Chemours Corporation was used as the coating liquid L for the second electrolyte membrane without any processing.

[0179] [Production of Catalyst-Coated Electrolyte Membrane] In order to evaluate the performance of the electrolyte membrane laminate, an electrolyte membrane with a catalyst layer, which is an application form of the electrolyte membrane laminate, was produced and evaluated.

[0180] Example 1 Preparation of First Electrolyte Membrane A PET film, Lumirror (registered trademark) 125T60, manufactured by Toray Industries, Inc., was adhered to and fixed to a SUS plate using Kapton (registered trademark) tape. The polymer electrolyte solution P1 was cast onto the PET film using a knife coater, and then dried at 100°C for 4 hours to obtain a film-like polymer. The film was then immersed in a 10% by mass aqueous sulfuric acid solution at 80°C for 24 hours to undergo proton substitution and deprotection reactions, and then thoroughly washed by immersion in a large excess of pure water for 24 hours to obtain a first electrolyte membrane (thickness: 100 μm).

[0181] [Preparation of Laminate L of First Electrolyte Membrane and First Intermediate Layer] The first intermediate layer coating solution E was cast onto the first electrolyte membrane using a knife coater, and dried at 100°C for 4 hours to form a first intermediate layer made of platinum catalyst-supporting carbon particles and "Nafion" (registered trademark) on the first electrolyte membrane. At this time, the solid basis weight was 0.67 mg / cm. ２ The thickness was adjusted so that

[0182] [Preparation of an anode catalyst layer transfer sheet on which a second electrolyte membrane is laminated] A commercially available polytetrafluoroethylene film was laminated with an iridium content of 1.0 mg / cm. ２ A catalyst layer was prepared by casting anode catalyst coating solution H so that the thickness of the anode catalyst layer became 3.5 μm and drying at 100° C. for 4 hours. Second electrolyte membrane coating solution J was further cast onto the catalyst layer and dried at 100° C. for 4 hours to obtain an anode catalyst layer transfer sheet (decal) on which the second electrolyte membrane was laminated. The coating thickness was adjusted so that the thickness of the second electrolyte membrane became 3.5 μm.

[0183] [Preparation of cathode catalyst layer transfer sheet] A commercially available polytetrafluoroethylene film was coated with platinum in an amount of 0.3 mg / cm. ２ The cathode catalyst coating solution H was cast onto the substrate so that the cathode catalyst layer was coated, and dried at 100° C. for 4 hours to prepare a cathode catalyst layer transfer sheet (decal).

[0184] [Preparation of catalyst-coated electrolyte membrane] The laminate L was peeled from the PET film, and the laminate L was superposed so that the first intermediate layer of the laminate L was in contact with the second intermediate layer of the anode catalyst layer transfer sheet and the first electrolyte membrane of the laminate L was in contact with the cathode catalyst layer of the cathode catalyst layer transfer sheet, and the laminate L was hot-pressed at 150°C and 5 MPa for 3 minutes. The temperature was lowered to 40°C or less while still pressed, and the pressure was then released to obtain a catalyst-coated electrolyte membrane. This catalyst-coated electrolyte membrane was composed of an anode catalyst layer / second electrolyte membrane / first intermediate layer / first electrolyte membrane / cathode catalyst layer.

[0185] Example 2 An electrolyte membrane with a catalyst layer was obtained in the same manner as in Example 1, except that the first intermediate layer coating liquid F was used instead of the first intermediate layer coating liquid E.

[0186] [Example 3] [Preparation of a cathode catalyst layer transfer sheet by laminating a second intermediate layer and a third electrolyte membrane] A commercially available polytetrafluoroethylene film was coated with platinum in an amount of 0.3 mg / cm. ２ A cathode catalyst layer was prepared by casting and applying Cathode Catalyst Coating Liquid I onto the cathode catalyst layer so that the thickness of the cathode catalyst layer was 3.5 μm, and drying at 100° C. for 4 hours. A third electrolyte membrane was laminated on the cathode catalyst layer by casting and applying Third Electrolyte Membrane Coating Liquid J (same as Second Electrolyte Membrane Coating Liquid J) onto the cathode catalyst layer and drying at 100° C. for 4 hours. A cathode catalyst layer transfer sheet (decal) was then prepared by casting and applying Second Intermediate Layer Coating Liquid E (same as First Intermediate Layer Coating Liquid E) onto the third electrolyte membrane and drying at 100° C. for 4 hours. The thickness of the third electrolyte membrane was 3.5 μm, and the solids basis weight of the second intermediate layer was 0.67 mg / cm. ２ The coating thickness was adjusted so that

[0187] [Preparation of catalyst layer-equipped electrolyte membrane] Except for using the above cathode catalyst layer transfer sheet, a catalyst layer-equipped electrolyte membrane was obtained in the same manner as in Example 1. This catalyst layer-equipped electrolyte membrane was composed of an anode catalyst layer / second electrolyte membrane / first intermediate layer / first electrolyte membrane / second intermediate layer / third electrolyte membrane / cathode catalyst layer.

[0188] Example 4 An electrolyte membrane with a catalyst layer was obtained in the same manner as in Example 1, except that the first intermediate layer coating liquid G was used instead of the first intermediate layer coating liquid E.

[0189] Example 5 An electrolyte membrane with a catalyst layer was obtained in the same manner as in Example 1, except that the first electrolyte membrane coating liquid P2 was used instead of the first electrolyte membrane coating liquid P1.

[0190] Example 6 An electrolyte membrane with a catalyst layer was obtained in the same manner as in Example 1, except that the first electrolyte membrane coating liquid P3 was used instead of the first electrolyte membrane coating liquid P1.

[0191] Example 7 An electrolyte membrane with a catalyst layer was obtained in the same manner as in Example 1, except that the first electrolyte membrane coating liquid P4 was used instead of the first electrolyte membrane coating liquid P1.

[0192] [Example 8] [Preparation of First Intermediate Layer Transfer Sheet] The first intermediate layer coating solution E was cast onto a commercially available polytetrafluoroethylene film using a knife coater, and then dried at 100°C for 4 hours to prepare a first intermediate layer transfer sheet made of platinum catalyst-supporting carbon particles and "Nafion" (registered trademark). At this time, the solid basis weight was 0.67 mg / cm ２ The thickness was adjusted so that

[0193] [Preparation of Laminate M of Second Catalyst Layer, First Electrolyte Membrane, and First Intermediate Layer] A first electrolyte membrane was prepared on a PET film using the first electrolyte membrane coating liquid P1 in the same manner as in Example 1. The first electrolyte membrane was peeled from the PET film, and the first electrolyte membrane was sandwiched between a cathode catalyst transfer sheet prepared in the same manner as in Example 1 and the first intermediate layer transfer sheet, followed by hot pressing at 150°C and 5 MPa for 3 minutes. The temperature was lowered to 40°C or less while still under pressure, and then the pressure was released, to obtain a laminate M of the second catalyst layer, the first electrolyte membrane, and the first intermediate layer.

[0194] [Preparation of Catalyst-Coated Electrolyte Membrane] An anode catalyst layer transfer sheet laminated with a second electrolyte membrane was prepared in the same manner as in Example 1. The polytetrafluoroethylene film in contact with the first intermediate layer was peeled off from the laminate M, and the first intermediate layer and the second electrolyte membrane were contacted and hot-pressed at 150°C and 5 MPa for 3 minutes. The temperature was lowered to 40°C or less under pressure, and the pressure was then released to obtain a catalyst-coated electrolyte membrane. This catalyst-coated electrolyte membrane was composed of an anode catalyst layer / second electrolyte membrane / first intermediate layer / first electrolyte membrane / cathode catalyst layer.

[0195] Example 9 A catalyst layer-equipped electrolyte membrane was obtained in the same manner as in Example 1, except that the thickness of the first electrolyte membrane was set to 50 μm.

[0196] Example 10 An electrolyte membrane with a catalyst layer was obtained in the same manner as in Example 1, except that the first intermediate layer coating liquid K was used instead of the first intermediate layer coating liquid E.

[0197] Comparative Example 1 A catalyst layer-equipped electrolyte membrane was obtained in the same manner as in Example 1, except that the first intermediate layer and the second electrolyte membrane were not disposed. This catalyst layer-equipped electrolyte membrane was composed of an anode catalyst layer / first electrolyte membrane / cathode catalyst layer.

[0198] Comparative Example 2 A catalyst-layered electrolyte membrane was obtained in the same manner as in Example 1, except that the first intermediate layer was not disposed. This catalyst-layered electrolyte membrane was composed of an anode catalyst layer / second electrolyte membrane / first electrolyte membrane / cathode catalyst layer.

[0199] [Comparative Example 3] A commercially available polytetrafluoroethylene film containing 0.3 mg / cm of platinum ２ An anode catalyst transfer sheet having only the anode catalyst was prepared by casting catalyst coating solution H so that the anode catalyst layer was formed on the first intermediate layer, the first electrolyte membrane, and the cathode catalyst layer was dried for 4 hours. A catalyst-coated electrolyte membrane was obtained in the same manner as in Example 1, except that the anode catalyst transfer sheet having only the anode catalyst was used instead of the anode catalyst layer transfer sheet having the second electrolyte membrane laminated thereon. This catalyst-coated electrolyte membrane was composed of an anode catalyst layer, a first intermediate layer, a first electrolyte membrane, and a cathode catalyst layer.

[0200] Comparative Example 4 Preparation of an anode catalyst layer transfer sheet with a second electrolyte membrane laminated thereon A commercially available polytetrafluoroethylene film was laminated with an iridium content of 1.0 mg / cm ２A catalyst layer was prepared by casting anode catalyst coating solution H onto a commercially available polytetrafluoroethylene film and drying at 100°C for 4 hours. Separately, a Nafion® membrane was obtained by casting second electrolyte membrane coating solution L onto a commercially available polytetrafluoroethylene film and drying at 100°C for 4 hours. The coating thickness was adjusted so that the Nafion® membrane had a thickness of 3.5 μm. Subsequently, platinum nanoparticles (average particle size 200 nm) manufactured by Sigma-Aldrich Japan (same company) were dispersed in ethanol and coated onto the Nafion® membrane at a mass ratio of platinum nanoparticles:Nafion® of 0.1:1. The platinum nanoparticle-coated "Nafion" (registered trademark) membrane was peeled from the tetrafluoroethylene film, and laminated so that the platinum nanoparticle-coated surface was in contact with the anode catalyst layer. In this state, the laminate was hot-pressed at 150°C and 5 MPa for 3 minutes, and then the temperature was lowered to 40°C or lower while still pressurized, and then the pressure was released, thereby obtaining an anode catalyst layer transfer sheet on which a second electrolyte membrane was laminated.

[0201] [Preparation of Electrolyte Membrane with Catalyst Layer] An electrolyte membrane with a catalyst layer was obtained in the same manner as in Example 1, except that the above-mentioned anode catalyst layer transfer sheet was used.

[0202] Comparative Example 5 An electrolyte membrane with a catalyst layer was obtained in the same manner as in Comparative Example 4, except that cerium oxide nanoparticles (particle size <50 nm) manufactured by Sigma-Aldrich Japan (same company) were used instead of platinum nanoparticles (average particle size 200 nm) manufactured by Sigma-Aldrich Japan (same company).

[0203] [Evaluation] The first electrolyte membranes produced in the above Examples and Comparative Examples were evaluated for IEC and phase separation structure. In addition, the catalyst layer-attached electrolyte membranes produced in the above Examples and Comparative Examples were evaluated for interlayer adhesion (peelability), water electrolysis performance (at 2.0 A / cm ２ The results are shown in Tables 1 to 3. The water electrolysis performance evaluation and the measurement of the hydrogen concentration in oxygen gas were carried out only on samples for which no delamination occurred in the evaluation of interlayer adhesion (peelability).

[0204]

[0205]

[0206]

[0207] Note 1) Polymer electrolyte in first electrolyte membrane coating liquid P1: block copolymer C1, polymer electrolyte in first electrolyte membrane coating liquid P2: random copolymer C2, polymer electrolyte in first electrolyte membrane coating liquid P3: polyarylene-based block copolymer C3, polymer electrolyte in first electrolyte membrane coating liquid P4: polyethersulfone-based block copolymer C4, polymer electrolyte in first intermediate layer coating liquid E and first intermediate layer coating liquid F: "Nafion" (registered trademark), Polymer electrolyte in first intermediate layer coating liquid G: block copolymer C1; polymer electrolyte in anode catalyst layer coating liquid H and cathode catalyst layer coating liquid I: "Nafion" (registered trademark); polymer electrolyte in second electrolyte membrane coating liquid J: "Nafion" (registered trademark); TEC10V60TPM: platinum catalyst-supported carbon particles (platinum support rate 60 mass%); "Vulcan" (registered trademark) XC72: carbon particles; Pt nanoparticles: platinum nanoparticles with an average particle size of 200 nm; CeO ２ Nanoparticles: CeO with particle size <50 nm ２ nanoparticles

[0208] The electrolyte membrane laminate, catalyst layer-equipped electrolyte membrane, and membrane electrode assembly of the present invention are each applicable to a variety of applications. For example, they are applicable to medical applications such as extracorporeal circulation columns and artificial skin, filtration applications, ion exchange resin applications, various structural material applications, and electrochemical applications. Among these, they are more preferably used in various electrochemical applications. Examples of electrochemical applications include fuel cells, redox flow batteries, water electrolysis hydrogen generators, and electrochemical hydrogen compression devices, with water electrolysis hydrogen generators being the most preferred.

Claims

1. An electrolyte membrane laminate comprising a first electrolyte membrane having a first main surface and a second main surface, and a first intermediate layer and a second electrolyte membrane, in this order, on the first main surface of the first electrolyte membrane, wherein the first electrolyte membrane contains a hydrocarbon-based polymer electrolyte having an ionic group, the first intermediate layer contains a polymer electrolyte and particles, the second electrolyte membrane contains a polymer electrolyte and particles containing a transition metal element, and the mass ratio of the particles to the polymer electrolyte contained in the first intermediate layer and / or the second intermediate layer (mass of particles / mass of polymer electrolyte) is 0.4 to 20.

0.

2. The electrolyte membrane stack according to claim 1 , further comprising a third electrolyte membrane on a second main surface of the first electrolyte membrane.

3. 3. The electrolyte membrane laminate according to claim 2, further comprising a second intermediate layer between the second main surface of the first electrolyte membrane and the third electrolyte membrane, the second intermediate layer including a polymer electrolyte and particles.

4. 4. The electrolyte membrane laminate according to claim 1, wherein the polymer electrolyte contained in the second electrolyte membrane and / or the third electrolyte membrane comprises a fluorine-based polymer electrolyte.

5. The electrolyte membrane laminate according to any one of claims 1 to 3, wherein the particles containing a transition metal element contained in the second electrolyte membrane and / or the third electrolyte membrane are particles containing at least one transition metal element selected from platinum, gold, silver, copper, palladium, ruthenium, rhodium, cerium, manganese, iridium, nickel, and cobalt.

6. 4. The electrolyte membrane laminate according to claim 1, wherein the particles containing a transition metal element contained in the second electrolyte membrane and / or the third electrolyte membrane include at least one selected from the group consisting of particles of a zero-valent metal, particles of a metal oxide, and particles of a poorly soluble metal salt.

7. 4. The electrolyte membrane laminate according to claim 1, wherein a mass ratio of the particles containing a transition metal element to the polymer electrolyte contained in the second electrolyte membrane and / or the third electrolyte membrane (mass of the particles containing a transition metal element / mass of the polymer electrolyte) is 0.01 to 0.

85.

8. 4. The electrolyte membrane laminate according to claim 1, wherein the particles contained in the first intermediate layer and / or the second intermediate layer are inorganic particles.

9. 4. The electrolyte membrane laminate according to claim 1, wherein the particles contained in the first intermediate layer and / or the second intermediate layer are particles containing carbon atoms.

10. 4. The electrolyte membrane laminate according to claim 1, wherein the particles contained in said first intermediate layer and / or said second intermediate layer are carbon particles and / or metal-supported carbon particles.

11. 4. The electrolyte membrane laminate according to claim 1, wherein the particles contained in the first intermediate layer and / or the second intermediate layer are carbon particles.

12. 4. The electrolyte membrane laminate according to claim 1, wherein the polymer electrolyte contained in the first intermediate layer and / or the second intermediate layer comprises a fluorine-based polymer electrolyte.

13. 4. The electrolyte membrane laminate according to claim 1, wherein the hydrocarbon-based polymer electrolyte contained in the first electrolyte membrane comprises an aromatic polyether-based polymer electrolyte.

14. 4. A catalyst-layered electrolyte membrane comprising a catalyst layer on each of both sides of the electrolyte membrane laminate according to claim 1, the catalyst-layered electrolyte membrane comprising a first catalyst layer on a first main surface side of the first electrolyte membrane of the electrolyte membrane laminate, and a second catalyst layer on a second main surface side of the first electrolyte membrane of the electrolyte membrane laminate.

15. 15. The electrolyte membrane with a catalyst layer according to claim 14, wherein the first catalyst layer is an anode catalyst layer, and the second catalyst layer is a cathode catalyst layer.

16. A membrane electrode assembly comprising the catalyst layer-attached electrolyte membrane according to claim 14.

17. A water electrolysis hydrogen generation device comprising the catalyst layer-equipped electrolyte membrane according to claim 14.

18. A laminate (L) in which a first intermediate layer is laminated on a first electrolyte membrane, and a first catalyst layer transfer sheet (T) in which a first catalyst layer and a second electrolyte membrane are laminated in this order on a first support Ｃ１ ) and a second catalyst layer transfer sheet (T Ｃ２ ) and The first intermediate layer of the laminate (L) and the first catalyst layer transfer sheet (T Ｃ１ ) is brought into contact with the second electrolyte membrane of the laminate (L), and the first electrolyte membrane of the laminate (L) and the second catalyst layer transfer sheet (T Ｃ２ a second catalyst layer formed on the first catalyst layer and a third catalyst layer formed on the second catalyst layer.

19. A laminate (L) in which a first intermediate layer is laminated on a first electrolyte membrane, and a first catalyst layer transfer sheet (T) in which a first catalyst layer and a second electrolyte membrane are laminated in this order on a first support Ｃ１ ) and a second catalyst layer transfer sheet (T Ｃ３ ) and The first intermediate layer of the laminate (L) and the first catalyst layer transfer sheet (T Ｃ１ ) is brought into contact with the second electrolyte membrane of the laminate (L), and the first electrolyte membrane of the laminate (L) and the second catalyst layer transfer sheet (T Ｃ３ and a second intermediate layer formed of the first material.

20. 20. The method for producing a catalyst-coated electrolyte membrane according to claim 18 or 19, wherein the first electrolyte membrane contains a hydrocarbon-based polymer electrolyte, and the first bonding layer contains a polymer electrolyte and inorganic particles.

21. 20. The method for producing a catalyst-coated electrolyte membrane according to claim 18, wherein the catalyst-coated electrolyte membrane is in the form of a long film.