JP5617491B2 - Membrane-electrode assembly intermediate, and membrane-electrode assembly intermediate, membrane-electrode assembly, and method for producing polymer electrolyte fuel cell - Google Patents

Description

  The present invention relates to a membrane-electrode assembly intermediate, a membrane-electrode assembly, and a polymer electrolyte fuel cell, and a membrane-electrode assembly intermediate and a method for producing the membrane-electrode assembly.

  A fuel cell is a cell in which electrodes are arranged on both sides of an electrolyte and generates electricity by an electrochemical reaction between hydrogen and oxygen, and only water is generated during power generation. Thus, unlike the conventional internal combustion engine, it is expected to spread as a next-generation clean energy system because it does not generate environmental load gas such as carbon dioxide. In particular, the polymer electrolyte fuel cell has a low operating temperature and low electrolyte resistance. In addition, it uses a highly active catalyst, so it can obtain high output even in a small size. Is expected to be put to practical use.

  In this polymer electrolyte fuel cell, generally, a catalyst layer and a conductive porous substrate are sequentially laminated on both surfaces of an electrolyte membrane, and a gasket is formed so as to surround the periphery of an electrode composed of the catalyst layer and the conductive porous substrate. And a structure in which these are sandwiched between separators. In the present specification, not only those in which electrodes are formed on both surfaces of an electrolyte membrane but also those in which gaskets are provided are referred to as membrane-electrode assemblies. As a method for producing a membrane-electrode assembly having this gasket, for example, in Patent Document 1, a substrate on which a catalyst layer is formed is prepared, and after the catalyst layer is thermally transferred from the substrate to both surfaces of the electrolyte membrane, A conductive porous substrate is bonded to each catalyst layer on the electrolyte membrane by hot pressing, and a gasket is installed so as to surround each electrode composed of the conductive porous substrate and the catalyst layer. Two membrane-electrode half assemblies with a base sheet in which an electrolyte membrane and an electrode are formed on one side of the base sheet and a gasket is arranged around the electrolyte membrane and electrodes are prepared. It has been proposed that after the material sheet is peeled off, the surfaces on the electrolyte membrane side of the two membrane-electrode half-joints are opposed to each other.

JP 2006-286560 A JP 2002-216789 A

  The method of manufacturing a membrane-electrode assembly as described above is performed when the catalyst layer is thermally transferred from the base material to both surfaces of the electrolyte membrane, and the two membrane-electrode half-joints are joined with the surfaces on the electrolyte membrane side facing each other. In doing so, there is a problem in that it is necessary to accurately position each substrate so that the centers of the catalyst layers are aligned with each other.

  Therefore, the present invention provides a membrane-electrode assembly intermediate, a membrane-electrode assembly, and a polymer electrolyte fuel cell, and a membrane-electrode assembly intermediate and a membrane-electrode assembly that do not require accurate positioning. It is an object to provide a method.

  The membrane-electrode assembly intermediate according to the present invention is made in order to solve the above problems, and is provided with a base sheet and a frame shape provided on one surface of the base sheet and having openings formed therein. A first conductive porous substrate formed on the substrate sheet in the opening, and a first conductive porous substrate formed in the opening on the first conductive porous substrate. A catalyst layer; an electrolyte membrane formed on the first catalyst layer in the opening; and a second catalyst layer formed on the electrolyte membrane in the opening.

When manufacturing the said membrane-electrode assembly intermediate body, in the opening of the gasket provided on the base material sheet, the 1st electroconductive porous base material, the 1st catalyst layer, the electrolyte membrane, and the 2nd By simply forming the catalyst layers in order, these horizontal positions naturally coincide. That is, the membrane-electrode assembly intermediate can be produced without accurately positioning the first conductive porous substrate, the first catalyst layer, the electrolyte membrane, and the second catalyst layer. . Further, the membrane - electrode assembly intermediate, it is possible to form all the layers in a single gasket, membrane - it is not necessary to bond the gasket to each other in the production of the electrode assembly, adhesion of the gasket between There is no gas leak from the mating portion.

  Moreover, the said membrane-electrode assembly intermediate body can form a 2nd electroconductive porous base material on a 2nd catalyst layer in the opening of a gasket.

  The membrane-electrode assembly according to the present invention includes a frame-like gasket having an opening, a first conductive porous substrate formed in the opening, and the first conductive material in the opening. A first catalyst layer formed on the conductive porous substrate; an electrolyte membrane formed on the first catalyst layer in the opening; and a second catalyst formed on the electrolyte membrane in the opening. And a second conductive porous substrate formed on the second catalyst layer in the opening.

  A polymer electrolyte fuel cell according to the present invention includes the membrane-electrode assembly, and a separator installed on each conductive porous substrate and gasket of the membrane-electrode assembly. .

  Moreover, the method for producing a membrane-electrode assembly intermediate according to the present invention includes a step of preparing a base sheet, and a step of providing a frame-like gasket having an opening formed on one surface of the base sheet. Forming a first conductive porous substrate on the substrate sheet in the opening; and forming a first catalyst layer on the first conductive porous substrate in the opening. And a step of forming an electrolyte membrane on the first catalyst layer in the opening, and a step of forming a second catalyst layer on the electrolyte membrane in the opening.

  If the 1st electroconductive porous base material, the 1st catalyst layer, the electrolyte membrane, and the 2nd catalyst layer are formed in order in the opening of a gasket, the manufacturing method of the above-mentioned membrane-electrode assembly intermediate will be described. Since the horizontal position can be naturally matched, it is not necessary to accurately position each layer. Further, according to the above method, since the lower surface of the electrolyte membrane is supported by the first catalyst layer, the electrolyte membrane is prevented from swelling when the material for the second catalyst layer is applied on the electrolyte membrane. can do.

  In addition, the method for producing a membrane-electrode assembly according to the present invention includes a method for producing the above-described membrane-electrode assembly intermediate, and a second conductive porous group on the second catalyst layer in the opening. A step of forming a material, and a step of peeling the substrate sheet from the membrane-electrode assembly intermediate formed with the second conductive porous substrate.

  According to the present invention, accurate positioning is not necessary.

It is (a) front sectional drawing of the membrane-electrode assembly intermediate body which concerns on embodiment of this invention, and (b) top view. It is front sectional drawing which shows the manufacturing method of the membrane-electrode assembly intermediate which concerns on embodiment of this invention. It is front sectional drawing which shows the manufacturing method of the membrane-electrode assembly which concerns on embodiment of this invention. 1 is a front cross-sectional view of a polymer electrolyte fuel cell according to an embodiment of the present invention. It is a top view of the membrane-electrode assembly intermediate body which concerns on the modification of the said embodiment.

  Hereinafter, embodiments of a membrane-electrode assembly intermediate, a membrane-electrode assembly, and a polymer electrolyte fuel cell according to the present invention, and a method for producing the membrane-electrode assembly intermediate and the membrane-electrode assembly will be described. Will be described with reference to FIG.

  As shown in FIGS. 1A and 1B, the membrane-electrode assembly intermediate 1 according to this embodiment is provided with a frame-like gasket 3 on a base sheet 2, and the gasket 3 In the opening 31, the first conductive porous substrate 4a, the first catalyst layer 5a, the electrolyte membrane 6, and the second catalyst layer 5b are sequentially laminated. The total thickness of the first conductive porous substrate 4 a, the first catalyst layer 5 a, the electrolyte membrane 6, and the second catalyst layer 5 b is smaller than the thickness of the gasket 3.

  The thickness of the base material sheet 2 is usually 10 to 1000 μm, preferably 50 to 500 μm, from the viewpoint of handleability. Examples of the material of the base sheet 2 include polyimide, polyethylene terephthalate, polyparabanic acid aramid, polyamide (nylon), polysulfone, polyethersulfone, polyphenylene sulfide, polyether ether ketone, polyetherimide, polyarylate, polyethylene naphthalate. Examples thereof include polymer films such as phthalate, polypropylene, and polyolefin. Further, heat resistance of ethylene tetrafluoroethylene copolymer (ETFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroperfluoroalkyl vinyl ether copolymer (PFA), polytetrafluoroethylene (PTFE), etc. Fluorine resin can also be used. Among them, a polymer film that is inexpensive and easily available is preferable, and polyethylene terephthalate or the like is more preferable.

  The thickness of the gasket 3 is usually 20 to 1000 μm, preferably 50 to 600 μm. The material of the gasket 3 is preferably a material having a gas barrier property that is strong enough to withstand heat pressing and does not leak fuel and oxidant to the outside. For example, a polyethylene terephthalate sheet or Teflon (registered trademark) Examples thereof include a sheet and a silicon rubber sheet.

  The thickness of the 1st electroconductive porous base material 4a is 20-500 micrometers normally, Preferably it is 50-300 micrometers. As a material of the first conductive porous substrate 4a, it is necessary to have a porous structure in order to efficiently supply fuel gas and oxidant gas as fuel to the catalyst layer. For example, conductive carbon fiber and resin are used. It is preferable to include. Moreover, the conductive carbon particle may be included. Examples of the conductive carbon fiber include vapor grown carbon fiber (VGCF), carbon nanotube, carbon nanowire, carbon nanowall, PAN-based carbon fiber, and pitch-based carbon fiber. These conductive carbon fibers may be used alone or in combination of two or more. The fiber diameter is not limited, and the average may be about 50 nm to 20 μm, preferably about 100 nm to 15 μm. The fiber length is not limited, and the average may be 1 μm to 1 mm, preferably about 5 to 600 μm. The aspect ratio is approximately 3 to 500. The fiber diameter, fiber length, and aspect ratio of the conductive carbon fiber can be measured by an image measured with a scanning electron microscope (SEM) or the like. As the resin, known or commercially available resins can be used. For example, ion conductive polymer resin, vinyl acetate resin, styrene-acrylic copolymer resin, styrene-vinyl acetate copolymer resin, styrene-acrylic copolymer resin, ethylene-vinyl acetate copolymer resin, polyester-acrylic Fluoro rubber such as copolymer resin, urethane resin, acrylic resin, propylene hexafluoride-vinylidene fluoride copolymer resin, ethylene trifluoride-vinylidene fluoride copolymer resin, silicone rubber, phenol resin, melamine Examples thereof include resins. These resins may be used alone or in combination of two or more. The conductive carbon particles are not particularly limited as long as they are conductive carbon materials, and known or commercially available ones can be used. Examples thereof include carbon black such as channel black, furnace black, ketjen black, acetylene black and lamp black; graphite; activated carbon and the like. These can be used alone or in combination of two or more. The conductivity of the gas diffusion layer can be improved by producing a sheet-like conductive porous layer and a conductive porous substrate containing these conductive carbon particles. The average particle size (arithmetic average particle size) of carbon black is not limited, and is usually about 5 nm to 200 nm, preferably about 20 nm to 80 nm. When carbon black aggregates are used, the thickness may be 10 to 600 nm, preferably 50 to 500 nm, and when graphite or activated carbon is used, the thickness may be 500 nm to 40 μm, preferably about 1 μm to 35 μm. The average particle size of the conductive carbon particles can be measured by, for example, a particle size distribution measuring device LA-920: manufactured by Horiba, Ltd.

  The thickness of the 1st catalyst layer 5a is 0.1-200 micrometers normally, Preferably it is 0.5-20 micrometers. Moreover, the thickness of the 2nd catalyst layer 5b is 0.1-200 micrometers normally, Preferably it is 0.5-20 micrometers. The first and second catalyst layers 5a and 5b can be known platinum-containing catalyst layers (cathode catalyst and anode catalyst). Specifically, it contains carbon particles carrying catalyst particles and an ion conductive polymer electrolyte. As the ion conductive polymer electrolyte, the same material as that used for the electrolyte membrane 6 described later can be used. The catalyst particles are not particularly limited as long as they are substances that promote the anode and cathode reactions in the fuel cell. For example, platinum or a platinum compound, and examples of the metal other than platinum include ruthenium, palladium, nickel, molybdenum, iridium, iron, silver, and the like. Examples of the platinum compound include an alloy of platinum and at least one metal selected from the group consisting of metals other than platinum. In general, the catalyst particles contained in the cathode catalyst layer are platinum, and the catalyst particles contained in the anode catalyst layer are an alloy of the metal and platinum. The catalytic metal fine particles not using platinum are at least one selected from the group consisting of iron, cobalt, nickel, palladium and silver, or an alloy composed of two or more of these. In the case of an alloy, alloy fine particles containing at least two of iron, cobalt and nickel are preferred. For example, iron-cobalt alloy, cobalt-nickel alloy, iron-nickel alloy, etc., and iron-cobalt-nickel alloy can be used. The carbon particles are not particularly limited as long as they have electrical conductivity, and widely known carbon particles can be used. For example, carbon black, graphite, activated carbon, or the like can be used alone or in combination. Examples of carbon black include channel black, furnace black, ketjen black, acetylene black, and lamp black. The arithmetic average particle size of the carbon particles is usually about 5 nm to 200 nm, preferably about 20 to 80 nm, and can be measured by a particle size distribution measuring device LA-920: manufactured by Horiba, Ltd.

  The thickness of the electrolyte membrane 6 is usually 1 to 200 μm, preferably 10 to 100 μm. The electrolyte membrane 6 is formed, for example, by applying a solution containing an ion conductive polymer electrolyte on the first catalyst layer 5a and drying. Examples of the ion conductive polymer electrolyte include a perfluorosulfonic acid-based fluorine ion exchange resin, more specifically, a perfluorocarbon sulfonic acid polymer in which the C—H bond of a hydrocarbon ion-exchange membrane is substituted with fluorine. (PFS polymer) and the like. By introducing a fluorine atom having high electronegativity, it is chemically very stable, the dissociation degree of the sulfonic acid group is high, and high ion conductivity can be realized. Specific examples of such an ion conductive polymer electrolyte include “Nafion” (registered trademark) manufactured by DuPont, “Flemion” (registered trademark) manufactured by Asahi Glass Co., Ltd., and “Aciplex” manufactured by Asahi Kasei Corporation. (Registered trademark) and the like.

  Next, the manufacturing method of the membrane-electrode assembly intermediate 1 described above, the membrane-electrode assembly 10 using the same, and the polymer electrolyte fuel cell 100 will be described.

First, the manufacturing method of the membrane-electrode assembly intermediate 1 will be described. As shown in FIG. 2 (a), the gasket 3 is bonded to the base sheet 2 with an adhesive, or physical by hot press or heat roll. Install by sticking together. Although it does not specifically limit as a material of an adhesive, For example, natural rubber, an acrylic resin, a silicone resin, a urethane resin etc. can be mentioned. Next, in the opening 31 of the gasket 3, the conductive porous substrate paste 100 is applied onto the substrate sheet 2 by a known method such as screen printing, spray coating, die coating, knife coating, inkjet, dispenser, or the like. Apply at a thickness of ˜300 μm. This conductive porous substrate paste is obtained by mixing the above-mentioned conductive porous substrate 4 material in a suitable dispersion medium, and the dispersion medium is not particularly limited. And organic solvents such as methyl ethyl ketone (MEK), acetone, toluene, xylene, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 3-butanol, 1-pentanol, ethylene glycol, or propylene glycol 1 to 3 carbon alcohols having about 1 to 5 carbon atoms are used singly or in combination of two or more. The blending ratio of the conductive porous substrate paste is not particularly limited. For example, the material of the conductive porous substrate 4 is 40 to 60% with respect to the dispersion medium 60 to 40% by volume ratio. can do. After applying the conductive porous base material paste, when the conductive porous base material paste is dried at 70 to 120 ° C. for 10 to 60 minutes, dispersion in the conductive porous base material paste is performed. The medium volatilizes, and the conductive porous substrate 4 having a thickness of 20 to 200 μm is formed on the substrate sheet 2 as shown in FIG.

  Next, a catalyst paste is prepared by mixing the material of the first catalyst layer 5a described above in the same dispersion medium as the conductive porous substrate paste. The catalyst paste is applied on the first conductive porous substrate 4a in the opening 31 by the known method as described above, and dried at 50 to 120 ° C. for 10 to 90 minutes. As shown in 2 (c), a first catalyst layer 5a is formed on the first conductive porous substrate 4a.

  Subsequently, the above-described hydrogen ion conductive polymer electrolyte-containing solution is applied to the first catalyst layer 5a in the opening 31 by the known method as described above, and is taken at 50 to 120 ° C. for 5 to 30 minutes. By drying, an electrolyte membrane 6 is formed on the first catalyst layer 5a as shown in FIG. 2 (d). Thereafter, a paste for a catalyst layer in which the material of the second catalyst layer 5b described above is mixed with an appropriate dispersion medium is applied onto the electrolyte membrane 6 and dried at 50 to 120 ° C. for 10 to 90 minutes. As shown in FIG. 2E, the second catalyst layer 5b is formed. The membrane-electrode assembly intermediate 1 of the present embodiment is completed by the procedure as described above.

  Next, a method for producing the membrane-electrode assembly 10 and the polymer electrolyte fuel cell 100 using the above-described membrane-electrode assembly intermediate 1 will be described. First, as shown in FIG. 3A, a mask 7 is formed on the gasket 3 of the membrane-electrode assembly 1. The mask 7 is not particularly limited as long as it can be peeled off from the gasket 3. For example, polyimide, polyethylene terephthalate, polyparabanic acid aramid, polyamide (nylon), polysulfone, polyethersulfone, polyphenylene sulfide, polyether etherketone, Examples thereof include polymer films such as polyetherimide, polyarylate, polyethylene naphthalate, polypropylene, and polyolefin. Further, heat resistance of ethylene tetrafluoroethylene copolymer (ETFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroperfluoroalkyl vinyl ether copolymer (PFA), polytetrafluoroethylene (PTFE), etc. A well-known or commercially available product such as a functional fluororesin can be used. Moreover, although the thickness of the mask 7 is based also on the thickness of the 2nd electroconductive porous base material 4b to form, it is 10-500 micrometers normally, Preferably it is 20-300 micrometers.

  With the mask 7 formed in this way, as shown in FIG. 3B, inside the gasket 3 and the mask 7, the same conductive porous base material as the first conductive porous base material 4a is used. The paste 41 is applied to the second catalyst layer 5b with a thickness of 100 to 300 μm by a known method as described above. Then, by drying the conductive porous substrate paste 41 at 70 to 120 ° C. for 10 to 60 minutes, the dispersion medium in the conductive porous substrate paste 41 is volatilized, and 50 to 200 μm. A second conductive porous substrate 4b having a thickness of 3 mm is formed (FIG. 3C). Thereafter, the mask 7 is peeled to obtain a membrane-electrode assembly intermediate 11 (FIG. 3D), and the membrane-electrode assembly is peeled from the membrane-electrode assembly intermediate 11 by peeling off the substrate sheet 2. 10 is completed (FIG. 3E). The membrane-electrode assembly 10 includes the gasket 3 and the total thickness of the first and second conductive porous substrates 4a and 4b, the electrolyte membrane 6, and the first and second catalyst layers 5a and 5b. The thickness is substantially the same.

  The separator 8 in which the gas flow path 81 is formed is disposed on both sides of the membrane-electrode assembly 10 thus manufactured, and the separator 8 and the conductive porous substrate 4 are electrically connected. The membrane-electrode assembly 10 is sandwiched between the separators 8 (FIG. 4). Thereby, the polymer electrolyte fuel cell 100 is completed.

As described above, in the present embodiment, the first conductive porous substrate 4 a, the first catalyst layer 5 b, the electrolyte membrane 6, the second catalyst layer 5 b, and the second electrode are formed in the opening 31 of the gasket 3. By simply forming the conductive porous substrate 4b in order, the horizontal position of each layer naturally matches, so that accurate positioning of each layer is unnecessary. In addition, since the lower surface of the electrolyte 6 is supported by the first catalyst layer 5 b, it is possible to prevent the electrolyte membrane 6 from swelling when the second catalyst layer paste is applied to the electrolyte membrane 6. . Furthermore, the membrane-electrode assembly 10 of the present embodiment includes a first conductive porous substrate 4a, a first catalyst layer 5b, an electrolyte membrane 6, a second catalyst layer 5b, and a second conductive porous. since Shitsumotozai 4b is formed in the opening 31 of a single gasket 3, it is not necessary to bond the gasket together Upon their production, it does not occur the gas leakage from the bonded portion of the gasket together. Moreover, since the membrane-electrode assembly 10 is formed by coating each layer, no gap is generated between the inner wall surface of the gasket 3 and each layer, and it is possible to suppress the occurrence of gas leak from this gap.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to these, A various change is possible unless it deviates from the meaning of this invention. For example, in the above embodiment, the first and second conductive porous substrates 4a and 4b, the electrolyte membrane 6, and the first and second catalyst layers 5a and 5b are formed by coating, but are formed in advance. You may form by arrange | positioning the made sheet-like thing. This pre-formed sheet may be a single layer, or a plurality of layers may be stacked. In addition, when using the sheet-like layer formed in advance, for example, the layer to which the material is applied and the sheet-like layer are alternately arranged, or the sheet-like layer is hot-pressed after stacking a plurality of the sheet-like layers. Thus, the layers can be bonded together. In addition, when arrange | positioning, each layer can be adhere | attached by arrange | positioning before the apply | coated layer dries.

  In addition, the first conductive porous substrate 4a and the first catalyst layer 5a, and the second conductive porous substrate 4b and the second catalyst layer 5b are at least one of the first conductive porous substrate 4a and the first catalyst layer 5a. You may form the water-repellent layer for providing water repellency to the 1st and 2nd electroconductive porous base materials 4a and 4b. The thickness of the water repellent layer is usually 0.5 to 20 μm, preferably 5 to 10 μm. The thickness of the water repellent layer is usually 0.5 to 50 μm, preferably 5 to 30 μm. Examples of the material for the water repellent layer include those containing at least a carbon material such as conductive carbon particles and conductive carbon fibers and a resin. Further, a known alcohol or dispersion medium may be added. The conductive carbon particles are not particularly limited as long as they are conductive carbon materials, and known or commercially available carbon materials can be used. For example, carbon black such as channel black, furnace black, ketjen black, acetylene black, lamp black, etc. Graphite, activated carbon and the like. These can be used alone or in combination of two or more. The average particle size (arithmetic average particle size) of carbon black is not limited, and is usually about 5 nm to 200 nm, preferably about 20 nm to 80 nm. Examples of the conductive carbon fiber used in the water repellent layer include vapor grown carbon fiber (VGCF), carbon nanotube, carbon nanowire, and carbon nanowall. These conductive carbon fibers may be used alone or in combination of two or more. The fiber diameter is not limited, and the average may be 50 to 400 nm, preferably about 100 to 250 nm. The fiber length is not limited, and the average may be 5 to 50 μm, preferably about 10 to 20 μm. The aspect ratio is approximately 10 to 500. The fiber diameter, fiber length, and aspect ratio of the conductive carbon fiber can be measured by an image measured with a scanning electron microscope (SEM) or the like. As the resin, a fluorine-based resin that imparts water repellency can be used. Examples thereof include polytetrafluoroethylene resin (PTFE), fluorinated ethylene propylene resin (FEP), perfluoroalkoxy resin (PFA), and tetrafluoroethylene-ethylene copolymer (ETFE). By containing such a fluororesin, water repellency can be imparted to the water repellent layer. In the water-repellent layer, the blending ratio is, for example, about 5 to 200 parts by weight (preferably 10 to 150 parts by weight) of a fluorine-based resin and 5 to 200 parts by weight of conductive carbon fibers with respect to 100 parts by weight of conductive carbon particles. (Preferably 10 to 150 parts by weight) and water 5 to 500 parts by weight (preferably 10 to 400 parts by weight) may be used.

  Moreover, in the said embodiment, although the membrane-electrode assembly intermediate body 1 was manufactured one by one, as shown in FIG. 5, it manufactures simultaneously in the state which connected the several membrane-electrode assembly intermediate body. You can also.

  The present invention will be described more specifically with reference to the following examples and comparative examples. In addition, this invention is not limited to the following Example.

Example 1
A membrane-electrode assembly 10 as shown in FIG. 3 (e) was produced in the following manner.

  First, a paste composition for forming a catalyst layer and a paste composition for a conductive porous substrate layer were prepared in the following manner.

  4 g of platinum catalyst-supporting carbon particles (manufactured by Tanaka Kikinzoku Kogyo Co., Ltd., “TEC10E50E”), 40 g of ion conductive polymer electrolyte membrane solution (Nafion 5 wt% solution: “DE-520” manufactured by DuPont), 12 g of distilled water, n- By mixing 20 g of butanol and 20 g of t-butanol and stirring and mixing with a disperser, an anode catalyst layer forming paste composition and a cathode catalyst layer forming paste composition were obtained.

  100 g of conductive carbon fiber (Osaka Gas Chemical Co., Ltd., “S-2404”), 50 g of styrene-acrylic acid copolymer resin (“AP-2675” manufactured by Showa Denko Co., Ltd.), dispersant (Kao ( Co., Ltd. “Emulgen A-60”) 25 g, ion conductive polymer electrolyte membrane solution (Nafion 5 wt% solution: “DE-520” manufactured by DuPont) 60 g, and water 100 g are dispersed to disperse the conductive porous substrate layer. A paste composition was prepared.

Next, a 500 μm-thick silicon rubber sheet (manufactured by ASONE Co., Ltd.) having an opening 31 is disposed as a gasket 3 on the PET film used as the base sheet 2, and the base sheet 2 and the gasket 3 are hot pressed. And pasted together. This is called sheet A. A 500 μm-thick silicon rubber sheet (manufactured by As One Co., Ltd.) having an opening 31 on this sheet A was placed as a mask, and the gasket 3 and the mask 9 were bonded together by hot pressing. This is called a sheet B. Then, the above-mentioned paste composition for a conductive porous substrate is applied to the opening 31 of the sheet B so as to have a thickness of about 200 μm using an applicator, and dried at 95 ° C. for 30 minutes. The conductive porous substrate layer 4a was formed. This is designated as Intermediate A.

Subsequently, on the intermediate A, the catalyst layer forming paste composition was applied in the opening 31 using an applicator, and dried at 95 ° C. for 30 minutes to form the first catalyst layer 5a. The coating amount of the catalyst layer forming paste composition was such that the platinum loading amount was about 0.5 mg / cm ^{2 in} both the anode catalyst layer and the cathode catalyst layer. This is designated as Intermediate B.

  Thereafter, an ion conductive polymer electrolyte membrane solution (Nafion 20 wt% solution: “DE2020” manufactured by Wako Pure Chemical Industries, Ltd.) is applied on the intermediate B using an applicator in the opening 31, and is applied at 95 ° C. for 30. The electrolyte membrane 6 was formed by partial drying. The thickness of the electrolyte membrane 6 was about 30 μm. This is intermediate C.

  On the intermediate C, the catalyst layer forming paste composition was applied in the opening 31 using an applicator and dried at 95 ° C. for 30 minutes to prepare a second catalyst layer 5b. This is designated as Intermediate D. At this time, since the electrolyte membrane 6 was supported by the first catalyst layer 5a, the catalyst layer forming paste composition could be applied without swelling the electrolyte membrane 6. Thereafter, the paste for conductive porous substrate is applied in the opening 31 of the intermediate D using the applicator in the same manner as the first conductive porous substrate layer 4a, and the second conductive porous substrate is coated. The base material layer 4b was formed. This is designated as Intermediate F. First, the mask 9 was peeled from the intermediate F, and then the substrate sheet 2 was peeled to obtain a membrane-electrode assembly 10.

(Example 2)
The same procedure as in Example 1 except that the coating thickness of the conductive porous substrate paste composition when forming the first and second conductive porous substrate layers 4a and 4b is about 50 μm. The membrane-electrode assembly 10 was manufactured. Also in this example, the catalyst layer forming paste composition could be applied on the electrolyte membrane 6 without swelling the electrolyte membrane 6.

DESCRIPTION OF SYMBOLS 1 Membrane-electrode assembly intermediate body 2 Base material sheet 3 Gasket 31 Opening 4a 1st electroconductive porous base material 4b 2nd electroconductive porous base material 5a 1st catalyst layer 5b 2nd catalyst layer 6 Electrolyte Membrane 8 Separator 10 Membrane-electrode assembly 100 Polymer electrolyte fuel cell

Claims (5)

A base sheet;
A frame-shaped gasket provided on one surface of the base sheet and having an opening formed thereon;
A first conductive porous substrate formed on the substrate sheet in the opening;
A first catalyst layer formed on the first conductive porous substrate in the opening;
An electrolyte membrane formed on the first catalyst layer in the opening;
A second catalyst layer formed on the electrolyte membrane in the opening;
A second conductive porous substrate formed on the second catalyst layer in the opening;
With
It said first and second conductive porous substrate, the electrolyte membrane, and the total thickness of said gasket thickness of the first and second catalyst layers Ri Ah at the same,
The said gasket is a membrane-electrode assembly intermediate body bonded together on the one surface of the said base material sheet . Preparing a base sheet; and
A step of providing a frame-shaped gasket with an opening formed on one surface of the base sheet;
Forming a first conductive porous substrate on the substrate sheet in the opening;
Forming a first catalyst layer on the first conductive porous substrate in the opening;
Forming an electrolyte membrane on the first catalyst layer in the opening;
Forming a second catalyst layer on the electrolyte membrane in the opening;
Forming a second conductive porous substrate on the second catalyst layer in the opening;
With
The step of forming the second conductive porous substrate comprises:
Forming a mask on the gasket;
Applying a conductive porous substrate paste on the second catalyst layer inside the gasket and the mask; and
Drying the conductive porous substrate paste to form the second conductive porous substrate;
Peeling the mask;
With
In the step of applying the conductive porous substrate paste, the first conductive porous substrate, the first catalyst layer, the electrolyte membrane, the second catalyst layer, and the conductive porous group. The method for producing a membrane-electrode assembly intermediate, wherein the total thickness of the material paste is larger than the thickness of the gasket. A method for producing the membrane-electrode assembly intermediate according to claim 2 ,
Peeling the base material sheet from the membrane-electrode assembly intermediate formed with the second conductive porous base material;
A method for producing a membrane-electrode assembly. It said first and second conductive porous substrate, the electrolyte membrane, and the thickness of the first and second sum and said gasket having a thickness of the catalyst layer is the same, according to claim 3 Manufacturing method of the membrane-electrode assembly. A method for producing a membrane-electrode assembly according to claim 3 or 4 ,
Installing a separator on each conductive porous substrate and gasket of the membrane-electrode assembly;
A method for producing a polymer electrolyte fuel cell.

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