JP5581942B2 - Membrane-electrode assembly intermediate, polymer electrolyte fuel cell, and method for producing membrane-electrode assembly - Google Patents

Description

  The present invention relates to a membrane-electrode assembly intermediate, a polymer electrolyte fuel cell, and a method for producing a 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, Patent Document 1 discloses a membrane-electrode with a base sheet in which an electrolyte membrane and an electrode are formed on one side of a base sheet, and a gasket is arranged around them. After producing two half-joints and peeling the base sheet from the membrane-electrode half-joint with a base sheet, the surfaces on the electrolyte membrane side of the two membrane-electrode half-joints are joined to face each other. Things have been proposed.

JP 2002-216789 A

  In the method for producing a membrane-electrode assembly as described above, it is necessary to peel the substrate sheet from the membrane-electrode half assembly with a substrate sheet when joining the membrane-electrode half assemblies. However, since conventional electrolyte membranes, catalyst layers, and gaskets are used with thin film thicknesses, the electrolyte membrane is particularly weak and is broken between the peeling of the base sheet and the joining of the membrane-electrode half-joints. There is a possibility that handling of the membrane-electrode half-junction becomes difficult.

  Then, this invention makes it a subject to provide the manufacturing method of the membrane-electrode assembly intermediate body and solid polymer fuel cell which are easy to handle, and a membrane-electrode assembly.

  The membrane-electrode assembly intermediate according to the present invention is made to solve the above problems, and is a base sheet and a frame provided on one surface of the base sheet and having an opening formed therein. And a conductive porous substrate formed on the substrate sheet in the opening.

  The membrane-electrode assembly intermediate is usually used by forming a catalyst layer on a conductive porous substrate in the opening of the gasket. When a membrane-electrode assembly is produced using the membrane-electrode assembly intermediate formed with the catalyst layer, two membrane-electrode assemblies intermediate formed with the catalyst layer are prepared, and at least one of the membranes is prepared. -An electrolyte membrane is disposed on the catalyst layer in the electrode assembly intermediate. Then, the surfaces opposite to the base sheet of the two membrane-electrode assembly intermediates are made to face each other and bonded together, and then from the conductive porous base material and the gasket of the two membrane-electrode assembly intermediates A membrane-electrode assembly is produced by peeling the base sheet. In this way, the membrane-electrode assembly intermediate of the present invention is supported by the base material sheet while it is bonded to the other membrane-electrode assembly intermediate, and the substrate is immediately before completion of the membrane-electrode assembly. Since the material sheet is peeled off, handling is easy through the entire manufacturing process of the membrane-electrode assembly.

  In the membrane-electrode assembly intermediate, a catalyst layer can be formed in advance on the conductive porous substrate in the opening of the gasket.

  The membrane-electrode assembly intermediate can form an electrolyte membrane on the catalyst layer. The area of the electrolyte membrane is not particularly limited, and may be larger or smaller than the opening area of the gasket, and may be substantially the same as the opening area, but may be larger than the opening area from the viewpoint of preventing gas leakage. preferable. The total thickness of the conductive porous substrate, the catalyst layer, and the electrolyte membrane may be larger or smaller than the thickness of the gasket, and may be substantially the same as the thickness of the gasket.

  In the membrane-electrode assembly intermediate, a water repellent layer may be formed between the conductive porous substrate and the catalyst layer. According to this configuration, water repellency can be imparted to the conductive porous substrate, and the gas permeability and gas diffusibility of the conductive porous substrate can be maintained.

  The method for producing a membrane-electrode assembly according to the present invention comprises the steps of preparing two membrane-electrode assembly intermediates having a catalyst layer formed on a conductive porous substrate, and at least one of the membrane-electrodes In the joined body intermediate, the step of forming an electrolyte membrane on the catalyst layer, and the two membrane-electrodes in a state where the surfaces opposite to the base sheet in the two membrane-electrode joined bodies are opposed to each other A step of bonding the bonded intermediate bodies, and a step of peeling the base sheet from the two bonded membrane-electrode bonded intermediate bodies.

  According to the manufacturing method of the membrane-electrode assembly, the membrane-electrode assembly intermediate can be continuously supported by the base sheet while the two membrane-electrode assemblies are bonded to each other. The electrode assembly intermediate is easy to handle.

  Moreover, in the said manufacturing method, the electroconductive porous base material of a membrane-electrode assembly intermediate body can be formed by application | coating. According to this method, the conductive porous substrate can be formed so that no gap is generated between the gasket and the conductive porous substrate. In the present invention, “application” is not particularly limited, but means various methods such as screen printing, spray coating, die coating, knife coating, inkjet, dispenser and the like.

  When forming at least one of the conductive porous substrate, the catalyst layer, and the electrolyte membrane by coating, the conductive porous substrate, the catalyst layer, and the electrolyte membrane are formed with a mask formed on the gasket. It is preferable. According to this method, the gasket can be protected so that the conductive porous substrate, the catalyst layer, and the electrolyte membrane do not adhere to the gasket. In addition, the thickness of the conductive porous substrate, catalyst layer, and electrolyte membrane is finally smaller than the coating thickness due to volatilization of the dispersion medium in the material for the conductive porous substrate, catalyst layer, and electrolyte membrane. However, according to this method, since the material can be applied exceeding the thickness of the gasket by the thickness of the mask, for example, the conductive porous substrate after drying, the catalyst layer, and the electrolyte membrane The total thickness can be combined with the thickness of the gasket, and the thickness of the conductive porous substrate and the gasket after drying, the total thickness of the conductive porous substrate and the catalyst layer after drying, and The thickness of the gasket can also be matched.

  Moreover, in the said manufacturing method, you may form a water repellent layer between the electroconductive porous base material and catalyst layer in a membrane-electrode assembly intermediate body. According to this method, water repellency can be imparted to the conductive porous substrate, and the gas permeability and gas diffusibility of the conductive porous substrate can be maintained.

  The polymer electrolyte fuel cell according to the present invention includes a membrane-electrode assembly produced by any of the production methods as described above, and each conductive porous substrate and gasket of the membrane-electrode assembly. And a separator installed in the.

  According to the present invention, handling becomes easy.

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 front sectional drawing which shows the manufacturing method of the membrane-electrode assembly intermediate which concerns on the modification of the said embodiment. It is front sectional drawing of the membrane-electrode assembly intermediate body which concerns on the modification of the said embodiment. It is front sectional drawing of the membrane-electrode assembly intermediate body which concerns on the modification of the said embodiment. It is front sectional drawing of the membrane-electrode assembly intermediate body which concerns on the modification of the said embodiment. It is front sectional drawing of the membrane-electrode assembly intermediate body which concerns on the modification of the said embodiment. It is front sectional drawing of the membrane-electrode assembly intermediate body which concerns on the modification of the said embodiment. It is front sectional drawing of the membrane-electrode assembly intermediate body which concerns on the modification of the said embodiment. It is front sectional drawing which shows the combination of the membrane-electrode assembly intermediate body which concerns on the modification of the said embodiment. It is front sectional drawing which shows the combination of the membrane-electrode assembly intermediate body which concerns on the modification of the said embodiment. It is a top view of the membrane-electrode assembly intermediate body which concerns on the modification of the said embodiment. (It is front sectional drawing which shows the manufacturing method of the membrane-electrode assembly which concerns on the comparative example of this invention.

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

  The membrane-electrode assembly intermediate 1 according to this embodiment includes a base sheet 2 and a gasket 3 formed on the base sheet 2, as shown in FIGS. 1 (a) and 1 (b). A conductive porous substrate 4, a catalyst layer 5, and an electrolyte membrane 6 are sequentially stacked on the substrate sheet 2 in the opening 31 of the gasket 3. The total thickness of the conductive porous substrate 4, the catalyst layer 5, and the electrolyte membrane 6 is substantially the same as the thickness of the gasket 3. In the present specification, a combination of the conductive porous substrate 4 and the catalyst layer 5 is referred to as an electrode.

  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 500 μm, preferably 50 to 300 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 conductive porous substrate 4 is usually 20 to 500 μm, preferably 50 to 300 μm. The material of the conductive porous substrate 4 needs to have a porous structure in order to efficiently supply fuel gas and oxidant gas as fuel to the catalyst layer, and includes, for example, conductive carbon fiber and resin. It is preferable. 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 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, 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 catalyst layer 5 is usually 0.1 to 200 μm, preferably 0.5 to 20 μm. The catalyst layer 5 can be a known platinum-containing catalyst layer (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 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 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, carbon nanotube, 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 catalyst layer 5 and drying it. 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 laminated on the base sheet 2 with an adhesive, or is physically processed 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 to 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 catalyst layer 5 described above in a dispersion medium similar to the conductive porous substrate paste. When this catalyst paste is applied on the conductive porous substrate 4 in the opening 31 by the known method as described above and dried at 50 to 120 ° C. for 10 to 90 minutes, FIG. As shown in FIG. 2, a catalyst layer 5 is formed on the conductive porous substrate 4.

  Thereafter, the above-described ion-conducting polymer electrolyte-containing solution is applied to the catalyst layer 5 in the opening 31 by the known method as described above, and dried at 50 to 120 ° C. for 5 to 30 minutes, As shown in FIG. 2D, the electrolyte membrane 6 is formed on the catalyst layer 5, and the membrane-electrode assembly intermediate 1 is completed.

  Next, a method for manufacturing the membrane-electrode assembly 10 and the polymer electrolyte fuel cell 100 using the membrane-electrode assembly intermediate 1 described above will be described. First, two membrane-electrode assembly intermediates 1 are prepared, and an adhesive layer 7 is applied to the upper surface of the gasket 3 in at least one membrane-electrode assembly intermediate 1 as shown in FIG. The adhesive layer 7 is formed by applying a known or commercially available adhesive containing an epoxy resin, an acrylic resin, a urethane resin, a silicone resin, or the like on the gasket 3 by a known method. The thickness of the adhesive layer 7 is not particularly limited, but no gap is generated between the gaskets 3 of the membrane-electrode assembly intermediate 1 when the two membrane-electrode assembly intermediates 1 are bonded to each other. It is preferable that it is such that it is 0.1-20 micrometers normally, Preferably it is 0.1-5 micrometers.

  After the adhesive layer 7 is formed on each membrane-electrode assembly intermediate 1, as shown in FIGS. 3B and 3C, the surface opposite to the base sheet 2, that is, the adhesive layer 7 side. Two membrane-electrode assembly intermediates 1 are arranged so that the surfaces of the membrane-electrode assemblies face each other, and hot pressing is performed from the base sheet 2 side of each membrane-electrode assembly intermediate 1 to bond the adhesive layers 7 together. About hot press conditions, press temperature and time are determined according to the hardening conditions of an adhesive agent. At this time, the electrolyte membranes 6 are pressed against each other and are in close contact with each other. Then, after the adhesive layer 7 is sufficiently hardened, the upper and lower substrate sheets 2 are peeled off to complete the membrane-electrode assembly 10 as shown in FIG.

  The separator 8 having the gas flow path 81 formed thereon is arranged on the upper and lower surfaces of the membrane-electrode assembly 10 manufactured as described above, 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 substrate sheet 2 of the membrane-electrode assembly intermediate 1 may be peeled off immediately before the completion of the membrane-electrode assembly 10, and the membrane-electrode assembly intermediate 1 is a membrane. -Since it is supported by the base material sheet 2 through the whole manufacturing process of the electrode assembly 10, the handling of the membrane-electrode assembly intermediate 1 is easy. Further, in the present embodiment, the gasket 3 and the conductive porous substrate are formed by applying the conductive porous substrate 4, the catalyst layer 5, and the electrolyte membrane 6 of the membrane-electrode assembly intermediate 1. 4, it is possible to prevent a gap from being formed between the catalyst layer 5 and the electrolyte membrane 6.

  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-described embodiment, the thickness of the conductive porous substrate 4 is smaller than the thickness of the gasket 3, but can be substantially the same as the thickness of the gasket 3. In order to make the thickness of the conductive porous substrate 4 substantially the same as the thickness of the gasket 3, the conductive porous substrate 4 is formed with the first mask 9 formed on the gasket 3 as shown in FIG. 5. The material 4 may be formed. That is, if the conductive porous substrate paste 41 is applied to the inside of the first mask 9 with a thickness that takes into account the reduction due to volatilization of the dispersion medium and dried, it is almost the same as the thickness of the gasket 3. A conductive porous substrate 4 having a thickness is formed. The first mask 9 on the gasket 3 may be peeled off from the gasket 3 after the conductive porous substrate 4 is formed. The first mask 9 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. Examples include polymer films such as ether ketone, polyether imide, 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. A rubber material such as silicone rubber can also be used. Although the thickness of the 1st mask 9 is based also on the compounding ratio of the paste for conductive porous base materials, and the thickness of the conductive porous base material 4, it is 10-500 micrometers normally, Preferably it is 20-300 micrometers.

  Moreover, in the said embodiment, although the conductive porous base material 4 was formed by apply | coating the paste for conductive porous base materials to the base material sheet 2, well-known carbon paper, carbon cloth, etc., for example. May be formed by placing the substrate on the base sheet 2.

  In the above embodiment, the catalyst layer 5 is formed directly on the conductive porous substrate 4, but the present invention is not limited to this, and the repellent property between the conductive porous substrate 4 and the catalyst layer 5 is not limited thereto. An aqueous layer can also be formed. 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 electrolyte membrane 6 was formed by apply | coating the ion conductive polymer electrolyte containing solution to the catalyst layer 5, for example, the electrolyte membrane previously formed in the sheet form is used as the catalyst layer 5. You may form by arrange | positioning on top and adhere | attaching on the catalyst layer 5 with a hot press etc. FIG.

  Moreover, in the said embodiment, although one electrolyte membrane 6 was formed in each membrane-electrode assembly intermediate body 1, for example, like the membrane-electrode assembly intermediate body 11 of FIG. An electrolyte membrane 61 can also be formed on the substrate. The area of the electrolyte membrane 61 may be larger or smaller than the area of the opening of the gasket 3 and may be substantially the same as the area of the opening 31. From the viewpoint of preventing gas leakage, the area of the electrolyte membrane 61 is larger than the area of the opening 31. Is preferably slightly larger.

  Further, in the membrane-electrode assembly intermediate 1 of the above embodiment, the total thickness of the electrode and the electrolyte membrane 6 and the thickness of the gasket 3 are substantially the same, but the present invention is not limited to this. Like the membrane-electrode assembly intermediate body 12 in FIG. 7, the total thickness of the electrode and the electrolyte membrane 6 may be larger than the thickness of the gasket 3. In this case, the electrolyte membrane 6 of the membrane-electrode assembly intermediate 12 can be formed as follows. That is, a second mask 91 is formed on the gasket 3 in advance, and in this state, an ion-conducting polymer electrolyte-containing solution is applied to the inside of the second mask 91 and dried, and then the second mask 91 is formed. The electrolyte membrane 6 can be formed by peeling the film. The second mask 91 is, for example, 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 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. Although the thickness of the 2nd mask 91 is based also on the thickness which match | combined the electrode and the catalyst layer 5, it is 1-50 micrometers normally, Preferably it is 5-20 micrometers. An adhesive layer for adhering these may be provided between the second mask 91 and the gasket 3, and this adhesive layer is used for adhering the substrate sheet 2 and the gasket 3 as described above. It can be formed of the same material as the adhesive.

  Further, like the membrane-electrode assembly intermediate 13 in FIG. 8, the thickness of the electrode and the electrolyte membrane 6 may be smaller than the thickness of the gasket 3. When a membrane-electrode assembly is produced using this membrane-electrode assembly intermediate 13, the electrolyte membrane 6 of the membrane-electrode assembly intermediate 13 is bonded to the electrolyte membrane of the other membrane-electrode assembly intermediate. For example, the other membrane-electrode assembly intermediate may be such that the total thickness of the electrode and electrolyte membrane as shown in FIG. 7 is larger than the thickness of the gasket.

  Further, in the membrane-electrode assembly intermediate 1 of the above embodiment, the area of the electrolyte membrane 6 is almost the same as the area of the opening 31 of the gasket 3, but is not limited to this, and the membrane-electrode of FIG. Like the bonded intermediate body 14, the area of the electrolyte membrane 6 may be larger than the area of the opening 31. The thickness of the electrode in the membrane-electrode assembly intermediate 14 is preferably approximately the same as the thickness of the gasket 3 when the electrolyte membrane 6 is formed of a known or commercially available single-wafer product. When formed by application, the thickness of the gasket 3 may not be the same.

  Further, the area of the electrolyte membrane 6 may be smaller than the area of the opening 31 as in the membrane-electrode assembly intermediate 15 in FIG. When a membrane-electrode assembly is produced using this membrane-electrode assembly intermediate 15, the entire catalyst layer 5 of the membrane-electrode assembly intermediate 15 is covered with an electrolyte membrane of the other membrane-electrode assembly intermediate. To cover the other membrane-electrode assembly intermediate, the area of the electrolyte membrane as shown in FIG. 9 may be larger than the area of the gasket opening.

  Moreover, the electrolyte 6 may not be formed on the catalyst layer 5 as in the membrane-electrode assembly intermediate 16 of FIG. When a membrane-electrode assembly is manufactured using this membrane-electrode assembly intermediate 16, the entire catalyst layer 5 of the membrane-electrode assembly intermediate 16 is covered with an electrolyte membrane of the other membrane-electrode assembly intermediate. The other membrane-electrode assembly intermediate may be formed so that the electrolyte membrane is formed and the area of the electrolyte membrane is equal to or larger than the area of the gasket opening.

  The membrane-electrode assembly 10 of the above embodiment has been manufactured using the two membrane-electrode assembly intermediates 1, but is not limited to this. For example, the membrane-electrode assembly of the above embodiment The intermediate body 1 and the membrane-electrode assembly intermediate bodies 11 to 16 as described above can be produced by different kinds or the same kind of combinations. In this combination of membrane-electrode assembly intermediates, the entire surface of the catalyst layer 5 of each membrane-electrode assembly intermediate is covered with the electrolyte membrane 6 when the membrane-electrode assembly intermediates are bonded together. It is necessary to make such a combination. For example, when the membrane-electrode assembly intermediate 12 and the membrane-electrode assembly intermediate 16 are combined, as shown in FIG. 12, the thickness of the electrode and the electrolyte membrane 6 in the membrane-electrode assembly intermediate 12 is determined by the gasket. When the membrane-electrode assembly intermediate body 12 and the electrode assembly intermediate body 16 are bonded together, the electrolyte membrane 6 of the electrode assembly intermediate body 12 is not the membrane-electrode assembly intermediate body 16. The catalyst layer 5 reaches the catalyst layer 5, and the entire surface of the catalyst layer 5 of the membrane-electrode assembly intermediate 16 is covered with the electrolyte membrane 6 of the membrane-electrode assembly intermediate 12.

  In addition, various membrane-electrode assembly intermediates such as the membrane-electrode assembly intermediates 11 (FIG. 13) and the membrane-electrode assembly intermediate 11 and the membrane-electrode assembly intermediate 1 can be combined. .

  In the above embodiment, the adhesive layer 7 is formed on the gasket 3 in both of the two membrane-electrode assembly intermediates 1. However, if the membrane-electrode assembly intermediates 1 can be bonded to each other, It is also possible to provide the adhesive layer 7 only on one membrane-electrode assembly intermediate 1.

  Moreover, in the said embodiment, although the membrane-electrode assembly intermediate body 1 was manufactured one by one, as shown in FIG. 14, 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)
A membrane-electrode assembly 10 as shown in FIG. 3D was manufactured in the following manner.

  First, a catalyst layer forming paste composition, a conductive porous substrate layer paste composition, and a water repellent layer paste composition 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 200 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. Pasted together. This is called sheet A. A 300 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 were bonded together by hot pressing. This is called a sheet B. Then, the above-described conductive porous substrate paste composition was applied in the opening 31 of the sheet B using an applicator so as to have a thickness of about 150 μm, and dried at 95 ° C. for 30 minutes. This is designated as Intermediate A.

Subsequently, the catalyst layer forming paste composition was applied onto the intermediate A using the applicator in the opening 31 and dried at 95 ° C. for 30 minutes to form the catalyst layer 5. 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. Subsequently, the mask was peeled off. This is referred to as an intermediate C (membrane-electrode assembly intermediate 1).

  On the gasket of intermediate C formed in this way, Konishi (for Aron Alpha plastic) was applied as the adhesive layer 7. This and another intermediate C were laminated and hot pressed. The pressing conditions were 120 ° C., 5 MPa, and 120 seconds. After confirming that the adhesive layer had hardened after hot pressing, the membrane-electrode assembly 10 was obtained by peeling the PET of the base material sheet 2. In the obtained membrane-electrode assembly 10, each intermediate body was supported by the base sheet 2 to the end, so that the electrolyte membrane and the like were not damaged.

(Comparative example)
Using the same catalyst layer forming paste composition as in the above example, a membrane-electrode assembly was prepared in the following manner. As shown in FIG. 15A, first, an ion conductive polymer electrolyte membrane solution (Nafion 20 wt% solution: “DE2020” manufactured by Wako Pure Chemical Industries, Ltd.) is used on a PET film used as the base sheet 201 by using an applicator. The electrolyte membrane 202 was formed by drying at 95 ° C. for 30 minutes. The thickness of the electrolyte membrane 202 was about 30 μm. The catalyst layer-forming paste composition was applied onto the electrolyte membrane 202 using an applicator, and dried at 95 ° C. for 30 minutes to prepare a catalyst layer 203. The coating amount of the catalyst layer forming paste composition was such that the amount of platinum supported was about 0.5 mg / cm ² . This is referred to as an intermediate D (catalyst layer-electrolyte membrane half-layer 20) (FIG. 15A). In order to produce a catalyst layer-electrolyte membrane laminate by pasting two intermediate bodies D together, when the base sheet 201 is peeled from the intermediate body D (FIG. 15B), the intermediate body D is torn, bent or the like. There was a drawback that it could not be peeled off well. Also, a conductive porous layer 204 (manufactured by Toray, carbon paper) was joined to the catalyst layer 203 side of the catalyst layer-electrolyte membrane laminate to form a membrane-electrode assembly 200.

DESCRIPTION OF SYMBOLS 1 Membrane-electrode assembly intermediate 2 Substrate sheet 3 Gasket 31 Opening 4 Conductive porous substrate 5 Catalyst layer 6 Electrolyte membrane 8 Separator 9 First mask 10 Membrane-electrode assembly 100 Solid polymer fuel cell

Claims (13)

A base sheet;
A frame-shaped gasket provided on one surface of the base sheet, in which an opening is formed;
A conductive porous substrate formed on the substrate sheet only in the opening;
A membrane-electrode assembly intermediate comprising: A base sheet;
A frame-shaped gasket provided on one surface of the base sheet and having one opening formed thereon;
A conductive porous substrate formed on the substrate sheet in the opening;
A membrane-electrode assembly intermediate comprising: A base sheet;
A frame-shaped gasket provided on one surface of the base sheet, in which an opening is formed;
A conductive porous substrate formed on the substrate sheet in the opening;
A membrane-electrode assembly intermediate comprising: The membrane-electrode assembly intermediate according to any one of claims 1 to 3 , further comprising a catalyst layer formed on the conductive porous substrate in the opening. A catalyst layer formed on the conductive porous substrate in the opening;
The membrane-electrode assembly intermediate according to claim 1 or 2 , further comprising an electrolyte membrane formed on the catalyst layer. The membrane-electrode assembly intermediate according to claim 4 or 5 , wherein a water-repellent layer is formed between the conductive porous substrate and the catalyst layer. The membrane-electrode assembly intermediate according to any one of claims 1 to 6, wherein the conductive porous substrate contains a resin. A base sheet;
A frame-shaped gasket provided on one surface of the base sheet, in which an opening is formed;
A conductive porous substrate formed on the substrate sheet in the opening;
Preparing two membrane-electrode assembly intermediates comprising a catalyst layer formed on the conductive porous substrate in the opening ;
Forming an electrolyte membrane on the catalyst layer in at least one of the membrane-electrode assembly intermediates;
Bonding the two membrane-electrode assembly intermediates in a state where the surfaces opposite to the base sheet in the two membrane-electrode assembly intermediates are opposed to each other;
Peeling the substrate sheet from the bonded two membrane-electrode assembly intermediate;
A method for producing a membrane-electrode assembly. The said membrane-electrode assembly intermediate is a manufacturing method of Claim 8 with which the said electroconductive porous base material is formed by application | coating. The said membrane-electrode assembly intermediate is a manufacturing method of Claim 9 in which the said electroconductive porous base material is formed in the state in which the mask was formed on the said gasket. The membrane - electrode assembly intermediate the water-repellent layer between the conductive porous substrate and the catalyst layer is formed, the manufacturing method according to any of claims 8-10. A base sheet;
A frame-shaped gasket provided on one surface of the base sheet, in which an opening is formed;
A conductive porous substrate formed on the substrate sheet only in the opening;
Preparing two membrane-electrode assembly intermediates comprising a catalyst layer formed on the conductive porous substrate in the opening;
Forming an electrolyte membrane on the catalyst layer in at least one of the membrane-electrode assembly intermediates;
Bonding the two membrane-electrode assembly intermediates in a state where the surfaces opposite to the base sheet in the two membrane-electrode assembly intermediates are opposed to each other;
Peeling the substrate sheet from the bonded two membrane-electrode assembly intermediate;
Comprising a membrane - electrode assembly, - film manufactured by the manufacturing method of the electrode assembly
A separator placed on each conductive porous substrate and gasket of the membrane-electrode assembly;
A solid polymer fuel cell comprising: A base sheet;
A frame-shaped gasket provided on one surface of the base sheet and having one opening formed thereon;
A conductive porous substrate formed on the substrate sheet in the opening;
Preparing two membrane-electrode assembly intermediates comprising a catalyst layer formed on the conductive porous substrate in the opening;
Forming an electrolyte membrane on the catalyst layer in at least one of the membrane-electrode assembly intermediates;
Bonding the two membrane-electrode assembly intermediates in a state where the surfaces opposite to the base sheet in the two membrane-electrode assembly intermediates are opposed to each other;
Peeling the substrate sheet from the bonded two membrane-electrode assembly intermediate;
Comprising a membrane - electrode assembly, - film manufactured by the manufacturing method of the electrode assembly
A separator placed on each conductive porous substrate and gasket of the membrane-electrode assembly;
A solid polymer fuel cell comprising:

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