JP5887692B2 - Catalyst layer with reinforcing membrane-electrolyte membrane laminate, membrane-electrode assembly with reinforcing membrane, polymer electrolyte fuel cell, and production method thereof - Google Patents

Description

  The present invention relates to a catalyst layer-electrolyte membrane laminate with a reinforcing membrane, a membrane-electrode assembly with a reinforcing membrane, a polymer electrolyte fuel cell, and methods for producing them.

  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.

  A solid polymer fuel cell uses a solid polymer electrolyte membrane having proton conductivity, and a catalyst layer and a conductive porous substrate are sequentially laminated on both surfaces of the electrolyte membrane. And it has the structure which has arrange | positioned the gasket so that the circumference | surroundings of the electrode which consists of this catalyst layer and a conductive porous base material may be enclosed, and also this was pinched | interposed with the separator. In order to generate power in this polymer electrolyte fuel cell, a fuel gas such as hydrogen is supplied to one electrode, and an oxidant gas such as oxygen is supplied to the other electrode.

  In such a polymer electrolyte fuel cell, a reinforcing membrane may be adhered to the electrolyte membrane from the viewpoint of preventing damage or effective use of the electrolyte membrane (see, for example, Patent Documents 1 and 2). This reinforcing film is usually formed with an opening at the center by punching or the like, but at this time, a convex portion is generated at the periphery of the opening. If the reinforcing film and the electrolyte membrane are bonded together by hot pressing or the like in a state where the convex portion is in contact with the electrolyte membrane, pressure concentrates on the convex portion, resulting in unevenness in the thickness of the electrolyte membrane. In order to prevent the occurrence of thickness unevenness in the electrolyte membrane, Patent Document 3 proposes a method in which the peripheral edge of the opening of the reinforcing membrane is trimmed by laser treatment or heat treatment to remove the convex portion.

Japanese Patent No. 3052536 JP 2004-47230 A JP 2010-129247 A

  By the way, since the polymer electrolyte fuel cell as described above is normally stacked and used in units of several hundred cells, if all the reinforcing films are subjected to laser treatment or heat treatment, the time and labor are excessive. There was a problem that productivity was low.

  Therefore, the present invention can prevent the occurrence of thickness unevenness in the ion conductive polymer electrolyte membrane, and has a highly productive catalyst layer-electrolyte membrane laminate, membrane-electrode assembly with reinforcement membrane, and high productivity. And a polymer electrolyte fuel cell, and a method for producing the same.

  The manufacturing method of a catalyst layer-electrolyte membrane laminate with a reinforcing membrane according to the present invention is made to solve the above-mentioned problems, and includes a step of preparing an ion conductive polymer electrolyte membrane and a reinforcing membrane, and the ion Forming a catalyst layer on both surfaces of the conductive polymer electrolyte membrane, and forming an opening for exposing the catalyst layer in a central portion of the reinforcing membrane by cutting with a cutting blade from one surface side And arranging the reinforcing membrane so that one surface of the reinforcing membrane faces at least one surface of the ion conductive polymer electrolyte membrane, and applying pressure from the other surface side of the reinforcing membrane, Adhering the reinforcing membrane to a molecular electrolyte membrane.

  In the manufacturing method, an opening is formed in the reinforcing film by cutting with a cutting blade from one side of the reinforcing film. At this time, in the reinforcing film, a convex portion is formed on the peripheral edge of the opening on the other surface side, but no convex portion is generated on the one surface side. This reinforcing membrane is disposed on the ion conductive polymer electrolyte membrane so that one surface side where no convex portion is formed faces the ion conductive polymer electrolyte membrane, and is pressed from the other surface side. The pressure applied to the ion conductive polymer electrolyte membrane does not become uneven, and it is possible to prevent the thickness of the ion conductive polymer electrolyte membrane from being uneven. Moreover, since it is not necessary to remove the convex part of a reinforcement film, productivity can also be improved. In the present invention, the order of performing the step of forming the catalyst layer on the electrolyte membrane and the step of bonding the reinforcing membrane to the electrolyte membrane is not particularly limited, and either step may be performed first. .

  In the above production method, the reinforcing membrane preferably has a lower Martens hardness based on ISO14577 than the ion conductive polymer electrolyte membrane. According to this method, when the reinforcing membrane is pressurized, deformation of the reinforcing membrane takes precedence over the ion conductive polymer electrolyte membrane, and pressure unevenness can be prevented from occurring in the ion conductive polymer electrolyte membrane. . The “Martens hardness based on ISO14577” in the present invention is a physical property value obtained by pushing into an object to be measured while applying a load to the indenter, and (test load) / (surface area of the indenter under the test load) It is calculated | required as [N / mm2].

  The Martens hardness can be measured using, for example, an ultra-micro hardness test system Picodenter HM500 (trade name, manufactured by Fisher Instruments Co., Ltd.). This measuring device pushes the indenter of the square pyramid or the triangular pyramid into the measurement object while applying a predetermined relatively small test load, and when the predetermined indentation depth is reached, the indenter depresses from the indentation depth. The surface area in contact is obtained, and the Martens hardness is obtained from the above formula. That is, when the indenter is pushed into the measurement object under the constant load measurement condition, the stress at that time with respect to the pushed-in depth is defined as Martens hardness. Measurement conditions are measured by pushing a square pyramid-shaped indenter to a depth of 1/10 of the depth film thickness from the surface of the measurement object in the thickness direction at a constant load application speed (10 mN / mm2 / sec).

  Further, in the above manufacturing method, the entire catalyst layer can be disposed in the opening of the reinforcing membrane, or the opening peripheral edge of the reinforcing membrane can be disposed on the outer peripheral edge of the catalyst layer. When the peripheral edge of the opening of the reinforcing membrane is placed on the outer peripheral edge of the catalyst layer, the catalyst layer plays a role of a buffer material between the reinforcing membrane and the ion conductive polymer electrolyte membrane. Thickness unevenness of the conductive polymer electrolyte membrane can be prevented.

  Moreover, in the said manufacturing method, the reinforcement film | membrane may have the contact bonding layer adhere | attached on an ion conductive polymer electrolyte membrane, and the base material layer provided on this contact bonding layer. This base material layer preferably has a gas barrier property that prevents permeation of fuel gas and oxidant gas from the viewpoint of preventing gas leakage.

  The method for producing a membrane-electrode assembly with a reinforcing membrane according to the present invention includes a method for producing a catalyst layer-electrolyte membrane laminate with a reinforcing membrane as described above, and forming a conductive porous substrate on the catalyst layer. And a process. In the present invention, the order of carrying out the step of forming the conductive porous substrate on the catalyst layer and the step of bonding the reinforcing membrane to the electrolyte membrane is not particularly limited, and either step is carried out first. May be.

  In the above manufacturing method, the entire conductive porous substrate can be disposed in the opening of the reinforcing membrane, or the opening peripheral edge of the reinforcing membrane can be disposed on the outer peripheral edge of the conductive porous substrate. . When the peripheral edge of the opening of the reinforcing membrane is disposed on the outer peripheral edge of the conductive porous substrate, the conductive porous substrate plays a role of a buffer material between the reinforcing membrane and the ion conductive polymer electrolyte membrane. Therefore, uneven thickness of the ion conductive polymer electrolyte membrane can be prevented more reliably.

  A method for producing a polymer electrolyte fuel cell according to the present invention encloses a method for producing a membrane-electrode assembly with a reinforcing membrane as described above, and an electrode including the catalyst layer and the conductive porous substrate. The step of providing a gasket on the reinforcing film and the step of providing a separator on the electrode and the gasket are provided.

  The catalyst layer-electrolyte membrane laminate with a reinforcing membrane according to the present invention includes an ion conductive polymer electrolyte membrane, a catalyst layer formed on both surfaces of the ion conductive polymer electrolyte membrane, and a cutting blade from one side. A reinforcing membrane having an opening formed by cutting at a central portion, the one surface being bonded to at least one surface of the ion conductive polymer electrolyte membrane so as to expose the catalyst layer from the opening; The reinforcing film has a convex portion formed by the cutting blade and projecting to the other surface side at a peripheral edge portion of the opening.

  In the reinforcing membrane of the catalyst layer-electrolyte membrane laminate with the reinforcing membrane, the convex portion formed when the opening is formed by the cutting blade in the reinforcing membrane is on the other side opposite to the ion conductive polymer electrolyte membrane. When the reinforcing membrane is pressure-bonded to the ion conductive polymer electrolyte membrane, the pressure applied to the ion conductive polymer electrolyte membrane does not become uneven due to the convex portions. For this reason, the catalyst layer-electrolyte membrane laminate with a reinforcing membrane can prevent the occurrence of uneven thickness in the ion conductive polymer electrolyte membrane, and it is not necessary to remove the convex portion. Can be improved.

  In the catalyst layer-electrolyte membrane laminate with the reinforcing membrane, the entire catalyst layer may be disposed in the opening of the reinforcing membrane, or the opening peripheral portion of the reinforcing membrane is disposed on the outer peripheral portion of the catalyst layer. Also good. When the opening peripheral edge of the reinforcing membrane is arranged on the outer peripheral edge of the catalyst layer, the catalyst layer plays a role of a buffer material between the reinforcing membrane and the ion conductive polymer electrolyte membrane. The thickness unevenness of the ion conductive polymer electrolyte membrane can be prevented.

  In addition, the catalyst layer-electrolyte membrane laminate with the reinforcing membrane is preferably configured such that the reinforcing membrane has a lower Martens hardness based on ISO14577 than the ion conductive polymer electrolyte membrane. According to this configuration, the pressure unevenness applied to the ion conductive polymer electrolyte membrane when the ion conductive polymer electrolyte membrane and the reinforcing membrane are pressure-bonded is further reduced.

  In the catalyst layer-electrolyte membrane laminate with the reinforcing membrane, the reinforcing membrane may include an adhesive layer that adheres to the ion conductive polymer electrolyte membrane and a base material layer that is provided on the adhesive layer. Good. This base material layer preferably has a gas barrier property that prevents permeation of fuel gas and oxidant gas from the viewpoint of preventing gas leakage.

  A membrane-electrode assembly with a reinforcing membrane according to the present invention includes the above-described catalyst layer-electrolyte membrane laminate with a reinforcing membrane, and a conductive porous substrate formed on the catalyst layer. .

  In the membrane-electrode assembly with the reinforcing membrane, the entire conductive porous substrate may be disposed in the opening of the reinforcing membrane, or the peripheral edge of the opening of the reinforcing membrane is the outer peripheral edge of the conductive porous substrate. It may be arranged above. When the opening peripheral edge of the reinforcing membrane is disposed on the outer peripheral edge of the conductive porous base material, the conductive porous base material is interposed between the reinforcing membrane and the ion conductive polymer electrolyte membrane. Since it plays a role, uneven thickness of the ion conductive polymer electrolyte membrane can be prevented more reliably.

  Further, the polymer electrolyte fuel cell according to the present invention includes the membrane-electrode assembly with a reinforcing membrane as described above, and the reinforcement so as to surround the electrode including the catalyst layer and the conductive porous substrate. A gasket provided on the membrane; and a separator provided on the electrode and the gasket.

  According to the present invention, it is possible to prevent occurrence of thickness unevenness in the ion conductive polymer electrolyte membrane and improve productivity.

1 is a front sectional view of a polymer electrolyte fuel cell according to an embodiment of the present invention. It is a front sectional view of a membrane-electrode assembly with a reinforcement membrane concerning one embodiment of the present invention. It is a partial expanded front sectional view of a membrane-electrode assembly with a reinforcing membrane concerning one embodiment of the present invention. It is a top view of the membrane-electrode assembly with a reinforcement film which concerns on one Embodiment of this invention. It is front sectional drawing which shows the manufacturing method of the polymer electrolyte fuel cell which concerns on one Embodiment of this invention. It is front sectional drawing which shows the manufacturing method of the reinforcement film which concerns on one Embodiment of this invention. It is front sectional drawing of the catalyst layer-electrolyte membrane laminated body with a reinforcement film which concerns on the modification of the said embodiment. It is front sectional drawing of the membrane-electrode assembly with a reinforcement film which concerns on the modification of the said embodiment.

  Hereinafter, embodiments of a catalyst layer-electrolyte membrane laminate, a membrane-electrode assembly with a reinforcing membrane, and a polymer electrolyte fuel cell according to the present invention, and a production method thereof will be described with reference to the drawings. .

  As shown in FIG. 1, the polymer electrolyte fuel cell 10 according to the present embodiment includes a membrane-electrode assembly 20 with a reinforcing membrane, a gasket 1, and a separator 2. As shown in FIG. 2, the membrane-electrode assembly 20 with a reinforcing membrane includes an ion conductive polymer electrolyte membrane 3, a catalyst layer 4, a conductive porous substrate 5, and a reinforcing membrane 7. In addition, what remove | excluded the conductive porous base material 5 from this membrane-electrode assembly 20 with a reinforcement film is equivalent to the catalyst layer-electrolyte membrane laminated body 30 with a reinforcement film of this invention.

  As shown in FIG. 2, the membrane-electrode assembly 20 with a reinforcing membrane has a catalyst layer 4 and a conductive porous material that are slightly smaller than the ion conductive polymer electrolyte membrane 3 on both sides of the ion conductive polymer electrolyte membrane 3. The base material 5 is laminated | stacked in order. The catalyst layer 4 and the conductive porous substrate 5 may each be formed in the same size as the ion conductive polymer electrolyte membrane 3, and the catalyst layer 4 and the conductive porous substrate 5 are different. It can also be formed in size. As shown in FIG. 3, the distance A from the outer peripheral edge of the electrode 6 composed of the catalyst layer 4 and the conductive porous substrate 5 to the outer peripheral edge of the ion conductive polymer electrolyte membrane 3 is 0 to 10 mm. preferable. The thickness of the ion conductive polymer electrolyte membrane 2 is usually about 20 to 250 μm, preferably about 20 to 80 μm. The thickness of the catalyst layer 3 is usually about 1 to 200 μm, preferably about 5 to 100 μm, and the thickness of the conductive porous substrate 5 is usually about 50 to 500 μm, preferably about 100 to 400 μm.

  As shown in FIGS. 2 and 4, the membrane-electrode assembly 20 with a reinforcing membrane has a reinforcing membrane 7 in which an opening 71 is formed at the center. The reinforcing membrane 7 is formed to be slightly larger than the ion conductive polymer electrolyte membrane 3, and is adhered to both surfaces of the ion conductive polymer electrolyte membrane 3 so that the electrode 6 is exposed from the opening 71. The outer peripheral edges are bonded to each other outside the polymer electrolyte membrane 3. In addition, as shown in FIG. 3, it is preferable that the distance B from the outer periphery of the reinforcement membrane 7 to the outer periphery of the ion conductive polymer electrolyte membrane 3 is 0-150 mm. The distance C from the inner peripheral edge of the reinforcing membrane 7 to the outer peripheral edge of the electrode 6 is preferably 5 mm or less. From the viewpoint of preventing load on the ion conductive polymer electrolyte membrane 3, the inner peripheral edge of the reinforcing membrane 7 and the electrode 6 are provided. It is more preferable that the outer peripheral edge is contacting. As shown in FIG. 2, the reinforcing film 7 has a first surface 72, which is an outer surface, and a convex portion 73 protruding outward is formed at the peripheral portion of the opening 71. This convex portion 73 will be described later. This occurs when the opening 71 is formed by the Thomson blade 91.

  As shown in FIG. 3, the reinforcing membrane 7 has a base material layer 74 that prevents permeation of fuel gas and oxidant gas, and an adhesive layer 75 that adheres to the ion conductive polymer electrolyte membrane 3. The thickness of the base material layer 74 is preferably 5 to 500 μm, and the thickness of the adhesive layer 75 is preferably 1 to 500 μm. The Martens hardness of the adhesive layer 75 is preferably smaller than the Martens hardness of the base material layer 74 and the Martens hardness of the ion conductive polymer electrolyte membrane 3. When the Martens hardness of the adhesive layer 75 is smaller than the Martens hardness of the base material layer 74, the base material layer 74 serves as a support for the adhesive layer 75 when the opening 71 is formed by the Thomson blade 91 described later, and the amount of pushing of the Thomson blade 91 is increased. As a result, the size of the convex portion 73 can be reduced. The Martens hardness of the adhesive layer 75, the base material layer 74, and the ion conductive polymer electrolyte membrane 3 is measured using, for example, an ultra-micro hardness test system Picodenter HM500 (trade name, manufactured by Fisher Instruments Co., Ltd.). Although not particularly limited, for example, the Martens hardness of the adhesive layer 75 is 0.1 N / mm2 to 50 N / mm2, whereas the Martens hardness of the base material layer is 20 N / mm2 to 200 N / mm2, The Martens hardness of the ion conductive polymer electrolyte membrane 3 is preferably 5 N / mm 2 to 120 N / mm 2.

  A frame-like gasket 1 is provided so as to surround the electrode 6 of the membrane-electrode assembly 20 with such a reinforcing membrane, and a separator 2 is provided on the gasket 1 and the electrode 6 (FIG. 1). The separator 2 has a gas flow path 21 formed in a region facing the conductive porous substrate 5 and is electrically connected to the conductive porous substrate 5.

  Next, the material of each component of the polymer electrolyte fuel cell 10 configured as described above will be described.

  The ion conductive polymer electrolyte membrane 3 is formed, for example, by applying a solution containing a hydrogen ion conductive polymer electrolyte on a substrate and drying it. Examples of the hydrogen ion conductive polymer electrolyte include a perfluorosulfonic acid-based fluorine ion exchange resin, more specifically, a perfluorocarbonsulfonic acid-based resin in which the C—H bond of a hydrocarbon ion-exchange membrane is substituted with fluorine. Examples include polymers (PFS polymers). 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 a hydrogen 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),“ Gore Select ”(registered trademark) manufactured by Gore, and the like. The concentration of the hydrogen ion conductive polymer electrolyte contained in the hydrogen ion conductive polymer electrolyte-containing solution is usually about 5 to 60% by weight, preferably about 20 to 40% by weight. In addition to the hydrogen ion conductive polymer electrolyte membrane, an anion conductive polymer ion conductive polymer electrolyte membrane and a liquid substance-impregnated membrane are also included. Examples of the anion-conducting ion-conducting polymer electrolyte membrane include hydrocarbon-based resins or fluorine-based resins. Specifically, as the hydrocarbon-based resins, Aciplex (registered trademark) A201, 211 manufactured by Asahi Kasei Corporation. , 221 and Neocepta (registered trademark) AM-1, AHA manufactured by Tokuyama Corp., and Tosflex (registered trademark) IE-SF34 manufactured by Tosoh Corp. as a fluororesin. Moreover, as a liquid substance impregnation film | membrane, polybenzimidazole (PBI) etc. are mentioned, for example.

  The catalyst layer 4 can be a known platinum-containing catalyst layer (cathode catalyst and anode catalyst). Specifically, it contains carbon particles carrying catalyst particles and a hydrogen ion conductive polymer electrolyte. As the hydrogen ion conductive polymer electrolyte, the same material as that used for the ion conductive polymer electrolyte membrane 3 described above can be used.

  Examples of the catalyst particles include platinum and platinum compounds. Examples of the platinum compound include an alloy of platinum and at least one metal selected from the group consisting of ruthenium, palladium, nickel, molybdenum, iridium, iron and the like. Usually, the catalyst particles contained in the catalyst layer on the cathode side are platinum, and the catalyst particles contained in the catalyst layer on the anode side are an alloy of the metal and platinum.

  The carbon particles are not limited as long as they have electrical conductivity, and known or commercially available carbon particles can be widely 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 diameter of the carbon particles is usually about 5 nm to 200 nm, preferably about 20 to 80 nm. The average particle size of the carbon particles can be measured by, for example, a particle size distribution measuring device LA-920: manufactured by Horiba, Ltd.

  The conductive porous substrate 5 is well known, and various conductive porous substrates that constitute a fuel electrode and an air electrode can be used. The conductive porous substrate 5 is composed of a porous conductive substrate in order to efficiently supply fuel gas and oxidant gas as fuel to the catalyst layer 4, and examples of the porous conductive substrate include: And carbon paper and carbon cloth.

  The reinforcing film 7 is composed of a base material layer 74 and an adhesive layer 75. As a material of the base material layer 74, polyester, polyamide, polyimide having a barrier property against water vapor, water, fuel gas and oxidant gas, Polymethyl tempene, polyphenylene oxide, polysulfone, polyether ether ketone, polyphenylene sulfide and the like can be preferably used. Specific examples of the polyester include polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, and polybutylene naphthalate.

  The material of the adhesive layer 75 is preferably a polyolefin resin, for example, medium density polyethylene, high density polyethylene, linear low density polyethylene, ethylene-α-olefin copolymer, polypropylene, polybutene, polyisobutene, poisoisobutylene, polybutadiene, Polyisoprene, ethylene-methacrylic acid copolymer, ethylene-unsaturated carboxylic acid copolymer such as ethylene-acrylic acid copolymer, ethylene-ethyl acrylate copolymer, ionomer resin, ethylene-vinyl acetate copolymer A polymer etc. can be used. In addition, acid-modified polyolefin resins and silane-modified polyolefin resins obtained by modifying them can be used, and among them, polypropylene and high-density polyethylene are preferable in terms of hardness.

  As the gasket 1, it is possible to use a gasket that has a strength sufficient to withstand hot pressing and has a gas barrier property that does not leak fuel and oxidant to the outside. For example, a polyethylene terephthalate sheet or Teflon ( (Registered trademark) sheet, silicon rubber sheet and the like.

  The separator 2 is a known conductive plate that is known and stable even in the environment inside the fuel cell. In general, a carbon plate in which the gas flow path 21 is formed is used. In addition, the separator 2 is made of a metal such as stainless steel, and a coating made of a conductive material such as chromium, a platinum group metal or oxide thereof, or a conductive polymer is formed on the surface of the metal. It is also possible to use a metal having a metal surface plated with a material such as silver, a platinum group composite oxide or chromium nitride.

  Next, a manufacturing method of the polymer electrolyte fuel cell 10 configured as described above will be described.

  First, as shown in FIGS. 5A and 5B, an ion conductive polymer electrolyte membrane 3 made of the above-described material is prepared, and catalyst layers 4 are formed on both surfaces of the ion conductive polymer electrolyte membrane 3. To do. The catalyst layer 4 can be formed by various methods such as coating and transfer. In the present embodiment, the catalyst layer 4 is formed by transfer using a transfer sheet 8 for forming a catalyst layer described later.

  Here, the manufacturing method of the transfer sheet 8 for forming a catalyst layer will be described. First, the carbon particles carrying the catalyst particles and the hydrogen ion conductive polymer electrolyte are mixed and dispersed in an appropriate dispersion medium to produce a catalyst layer forming composition. Then, the catalyst layer forming composition is applied onto the transfer substrate 81 through a release layer as necessary so that the catalyst layer 4 having a desired film thickness is formed. In addition, as a coating method of the composition for catalyst layer formation, well-known coating methods, such as screen printing, spray coating, die coating, knife coating, can be mentioned. After coating the catalyst layer forming composition, the catalyst layer 4 is formed on the transfer substrate 81 by drying at a predetermined temperature and time. The drying temperature is usually about 40 to 100 ° C., preferably about 60 to 80 ° C., and the drying time is usually about 5 minutes to 2 hours, preferably about 10 minutes to 1 hour, depending on the drying temperature. .

  Examples of the dispersion medium used in the composition for forming a catalyst layer include various alcohols, various ethers, various dialkyl sulfoxides, water, or a mixture thereof. Among these, alcohols are preferable. Examples of alcohols include monohydric alcohols having 1 to 4 carbon atoms such as methanol, ethanol, n-propanol, isopropanol, n-butanol, and tert-butanol, and various polyhydric alcohols.

  As the transfer substrate 81, for example, polyimide, polyethylene terephthalate, polyparvanic acid aramid, polyamide (nylon), polysulfone, polyethersulfone, polyphenylene sulfide, polyether ether ketone, polyetherimide, polyarylate, polyethylene naphthalate. And the like. 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. Furthermore, the transfer substrate 81 may be coated paper such as art paper, coated paper, and lightweight coated paper, non-coated paper such as notebook paper and copy paper, in addition to the polymer film. The thickness of the transfer substrate 81 is usually about 6 to 100 μm, preferably about 10 to 30 μm, from the viewpoints of handleability and economy. Therefore, the transfer substrate 81 is preferably a polymer film that is inexpensive and easily available, and more preferably polyethylene terephthalate.

  Returning to FIG. 5, the description of the method for producing the polymer electrolyte fuel cell 10 will be continued. As shown in FIG. 5A, the transfer sheet 8 for forming a catalyst layer is disposed on both surfaces of the ion conductive polymer electrolyte membrane 3 so that the catalyst layer 4 faces the ion conductive polymer electrolyte membrane 3. Next, the catalyst layer 4 is transferred to the ion conductive polymer electrolyte membrane 3 by hot pressing from the back side of the catalyst layer forming transfer sheet 8. Then, as shown in FIG. 5 (b), the transfer base material 81 is peeled from the ion conductive polymer electrolyte membrane 3 and the catalyst layer 4, thereby forming the catalyst layer 4 on the ion conductive polymer electrolyte membrane 3. Is done. In the ion conductive polymer electrolyte membrane 3, it is preferable to form the catalyst layer 4 on both sides simultaneously from the viewpoint of workability, but the catalyst layer 4 can also be formed on each side. In order to avoid transfer defects, the pressure level of the hot press is usually about 0.5 to 20 MPa, preferably about 1 to 10 MPa, and it is preferable that the pressing surface is heated during pressing. The heating temperature is usually 200 ° C. or lower, preferably 150 ° C. or lower, in order to avoid damage or deformation of the ion conductive polymer electrolyte membrane 3.

  Next, as shown in FIG. 5 (c), a reinforcing membrane 7 is bonded to the ion conductive polymer electrolyte membrane 3. Here, the manufacturing method of the reinforcing film 7 will be described. First, a sheet-like base material layer 74 made of the above-described material is prepared. Next, the material of the adhesive layer 75 described above is melted and extruded onto the base material layer 74 by a melt extrusion method, thereby forming a reinforcing film precursor having the base material layer 74 and the adhesive layer 75. Thereafter, the reinforcing film 7 is completed by forming an opening 71 in the central portion of the reinforcing film precursor with a cutting tool 9 as shown in FIG.

  As shown in FIG. 6A, the cutting instrument 9 includes a Thomson blade (cutting blade) 91 for punching out the reinforcing film precursor and a support plate 92 for supporting the reinforcing film precursor. The Thomson blade 91 is made of metal, has a rectangular frame shape in plan view, and has an inner vertical surface 911 and an outer inclined surface 912. Further, the inside of the Thomson blade 91 is filled with an elastically shrinkable porous body 93 such as sponge or rubber, for example. Examples of the material of the support plate 92 include resin, metal, ceramics, and the like, but resin is preferable from the viewpoint of punchability.

  In such a cutting tool 9, the reinforcing film precursor is placed on the Thomson blade 91 and the porous body 93 so that the adhesive layer 75 is located below, and the support plate 92 is fixed above them (FIG. 6 (a). )). When the Thomson blade 91 and the porous body 93 are moved upward in this state, the central portion of the reinforcing film precursor is punched from the adhesive layer 75 side to form an opening 71, thereby completing the reinforcing film 7 (FIG. 6 ( b)). At this time, a convex portion 73 generally called a burr is formed on the peripheral portion of the opening 71 in the first surface 72 of the reinforcing film 7. When the reinforcing film precursor is punched, the upper surface is supported by the support plate 92 and the lower surface is in contact with the porous body 93 so that excessive deformation is suppressed.

  Returning to FIG. 5, the description of the method for producing the polymer electrolyte fuel cell 10 will be continued. The reinforcing membrane 7 produced as described above is formed on both surfaces of the ion conductive polymer electrolyte membrane 3 so that the first surface 72 on which the convex portions 73 are formed faces outward and the catalyst layer 4 is exposed from the opening 71. It arrange | positions above (FIG.5 (c)). Then, when the reinforcing membrane 7 is bonded to the ion conductive polymer electrolyte membrane 3 by performing hot pressing from the first surface 72 side of the reinforcing membrane 7, the catalyst layer-electrolyte membrane laminate 30 with the reinforcing membrane is completed. . In the ion conductive polymer electrolyte membrane 3, it is preferable to attach the reinforcing film 7 simultaneously on both sides from the viewpoint of workability, but the reinforcing membrane 7 may be adhered to each side. Moreover, the pressurization level of a hot press is about 0.5-20 MPa normally, Preferably it is about 1-10 MPa, and it is preferable that a pressurization surface is heated at the time of pressurization from a viewpoint of an adhesive improvement. The heating temperature is usually 200 ° C. or lower, preferably 150 ° C. or lower, in order to avoid damage or deformation of the ion conductive polymer electrolyte membrane 3.

  Then, as shown in FIG. 5 (d), the conductive porous substrate 5 is disposed on the catalyst layer 4 in the opening 71 of the reinforcing film 7, and the conductive porous substrate 5 is heated to the catalyst layer 4. When the pressure bonding is performed, the membrane-electrode assembly 20 with the reinforcing film is completed.

  Thereafter, as shown in FIG. 5 (e), the gasket 1 is disposed on the reinforcing film 7 so as to surround the periphery of the electrode 6 composed of the catalyst layer 4 and the conductive porous substrate 5. And the separator 2 is arrange | positioned on the conductive porous base material 5 and the gasket 1 so that the gas flow path 21 may oppose the conductive porous base material 5, and the separator 2 and the conductive porous base material 5 are electrically connected. Thus, the solid polymer fuel cell 10 is completed.

  As described above, in the above-described embodiment, the reinforcing film 7 has the convex portion 73 formed on the first surface 72 by the Thomson blade 91, and the ion conductive polymer so that the first surface 72 faces outward. It is disposed on the electrolyte membrane 3. For this reason, when the reinforcing membrane 7 is pressure-bonded to the ion conductive polymer electrolyte membrane 3, the pressure applied to the ion conductive polymer electrolyte membrane 3 by the convex portion 73 does not become uneven, and the ion conductivity high It is possible to prevent the thickness unevenness from occurring in the molecular electrolyte membrane 3. Moreover, since it is not necessary to remove the convex part 73 from the reinforcing film 7, productivity can be improved and manufacturing cost can also be reduced.

  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 catalyst layer 4 is formed in the opening 71 of the reinforcing membrane 7 in the catalyst layer-electrolyte membrane laminate 30 with the reinforcing membrane, but the catalyst layer-electrolyte membrane laminate with the reinforcing membrane in FIG. As in 300, the peripheral edge of the opening 71 can be arranged on the outer peripheral edge of the catalyst layer 4. Moreover, in the said embodiment, although the electroconductive porous base material 5 was formed in the opening 71 of the reinforcement membrane 7 in the membrane-electrode assembly 20 with a reinforcement film, the membrane-electrode assembly with a reinforcement film in FIG. As in the case of 200, the peripheral edge of the opening 71 can be arranged on the outer peripheral edge of the conductive porous substrate 5.

  In the above embodiment, after the catalyst layer 4 is formed on the ion conductive polymer electrolyte membrane 3, the reinforcing film 7 is adhered to the ion conductive polymer electrolyte membrane 3. Is not particularly limited. For example, the catalyst layer 4 may be formed after the reinforcing film 7 is bonded to the ion conductive polymer electrolyte membrane 3. Moreover, in the said embodiment, although the electroconductive porous base material 5 was formed after adhere | attaching the reinforcement film | membrane 7 to the ion conductive polymer electrolyte membrane 3, the reinforcement film | membrane 7 is formed after formation of the electroconductive porous base material 5. FIG. Can be adhered to the ion conductive polymer electrolyte membrane 3.

  Moreover, in the said embodiment, although the reinforcement film | membrane 7 was adhere | attached on both surfaces of the ion conductive polymer electrolyte membrane 3, you may adhere | attach only on the single side | surface of the ion conductive polymer electrolyte membrane 3. FIG.

  In the above embodiment, the reinforcing membrane 7 is bonded to the ion conductive polymer electrolyte membrane 3 by hot pressing. However, when the reinforcing membrane 7 is bonded to the ion conductive polymer electrolyte membrane 3, at least the reinforcing membrane is used. 7 may be pressurized, and it is not always necessary to heat the pressure surface.

  In the above embodiment, the opening 71 of the reinforcing film 7 is formed by punching with the Thomson blade 91, but is not particularly limited as long as it is cut with a cutting blade. For example, punching using an etching blade, leather blade In addition, the opening can be formed in the reinforcing film by a slit using a shear blade or a score blade.

  Moreover, in the said embodiment, although the reinforcement film | membrane 7 was comprised from the two layers of the contact bonding layer 75 and the base material layer 74, it may be comprised by three or more layers, for example, the contact bonding layer of the said embodiment. An adhesive layer for adhering to the gasket 1 may be further laminated on 75 and the base material layer 74. In addition, the reinforcing film 7 may have a single-layer structure. In this case, the same material as the base material layer 74 or the same material as the adhesive layer 75 can be used. When the reinforcing membrane 7 is a single layer, a known or commercially available material including, for example, an epoxy resin, an acrylic resin, a urethane resin, a silicone resin, or the like is used to bond the reinforcing membrane 7 and the ion conductive polymer electrolyte membrane 3. An adhesive may be used.

  In the above embodiment, the constituent elements such as the ion conductive polymer electrolyte membrane 3, the catalyst layer 4, the conductive porous substrate 5, the reinforcing membrane 7, and the opening 71 are all rectangular in a plan view. However, it can be formed in various shapes such as a circular shape in a plan view.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

Example 1
First, a transfer sheet 8 for forming a catalyst layer was produced in the following manner. 1 g of 1-butanol, 10 g of 3-butanol, 20 g of fluororesin (5 wt% Nafion binder, DuPont) and 6 g of water are added to 2 g of platinum catalyst-supported carbon (platinum supported amount: 45.7 wt%, manufactured by Tanaka Kikinzoku Co., Ltd., TEC10E50E). Were added, and these were stirred and mixed with a disperser to prepare a composition for forming a catalyst layer. Then, a polyester film (manufactured by Toray, X44, film thickness 25 μm) is prepared as the transfer substrate 81, and the catalyst layer forming composition is applied onto the transfer substrate 81 and dried, and this is 50 × 50 mm. Cut to size.

  Next, NRE212CS (manufactured by Dupont) having a film thickness of 53 μm cut to a size of 63 × 63 mm is prepared as the ion conductive polymer electrolyte membrane 3, and the catalyst layer 4 is formed on the ion conductive polymer electrolyte membrane 3. The catalyst layer forming transfer sheet 8 described above was placed centering on both surfaces of the ion conductive polymer electrolyte membrane 3 so as to face each other. And the catalyst layer 4 was formed in both surfaces of the ion conductive polymer electrolyte membrane 3 by heat-pressing on conditions of 135 degreeC, 5.0 Mpa, and 150 second, and the catalyst layer-electrolyte membrane laminated body was produced. The catalyst layer 4 has a thickness of 20 μm.

  Subsequently, the reinforcing film 7 was produced in the following manner. First, biaxially stretched polyethylene naphthalate (manufactured by Teijin Ltd., Teonex, film thickness: 12 μm) is prepared as the base material layer 74, and the unsaturated carboxylic acid graft-modified polypropylene (Sumitomo) in a molten state is prepared on the base material layer 74. A chemical admer “SF-741”) was extruded to a thickness of 30 μm to form an adhesive layer 75, which was used as a reinforcing membrane precursor. Then, the reinforcing film precursor is moved from the adhesive layer 75 side to the base material layer 74 side so that the entire size becomes 80 × 80 mm and an opening 71 having a size of 52 × 52 mm is formed in the central portion. The reinforcing film 7 was produced by punching with a Thomson blade.

  This reinforcing membrane 7 was placed centering on both surfaces of the above-described catalyst layer-electrolyte membrane laminate so that the adhesive layer 75 was opposed to the ion conductive polymer electrolyte membrane 3. Then, the reinforcing membrane 7 was adhered to the catalyst layer-electrolyte membrane laminate by hot pressing under conditions of 130 ° C., 1.0 MPa, 30 seconds, and a catalyst layer-electrolyte membrane laminate 30 with a reinforcing membrane was produced.

  Next, on the catalyst layer 4 exposed from the opening 71 of the reinforcing membrane 7, carbon paper (TGP-H-090, thickness 280 μm) cut to a size of 49 × 49 mm is made conductive. It laminated | stacked as the porous base material 5, and formed the membrane-electrode assembly 20 with a reinforcement film. Furthermore, the polymer electrolyte fuel cell 10 was produced by installing the gasket 1 and the separator 2 on the membrane-electrode assembly 20 with a reinforcing membrane.

(Example 2)
A polymer electrolyte fuel cell 10 was produced in the same manner as in Example 1 except that FumapemA (manufactured by Fumatech) was used for the ion conductive polymer electrolyte membrane 3.

(Comparative Example 1)
A polymer electrolyte fuel cell was produced in the same manner as in Example 1 except for the production method of the reinforcing membrane. Reinforcing film of the comparative example, to prepare a reinforcing film precursor in the same manner as in the above Example, it was prepared by punching the reinforcing film precursor from the substrate layer 74 side to the adhesive layer 75 side.

(Hardness measurement)
The hardness of the ion conductive polymer electrolyte membrane 3 and the adhesive layer 75 used in Examples 1 and 2 and the comparative example was determined using an ultra-micro hardness test system Picodenter HM500 (trade name, manufactured by Fisher Instruments Co., Ltd.). It measured using. Measurement conditions were measured by pushing a square pyramid-shaped indenter to a depth of 1/10 of the depth film thickness in a room environment at 25 ° C. from the surface in a vertical direction at a constant load application rate (10 mN / mm 2 / sec).

(Evaluation method)
A load fluctuation cycle test was performed on each polymer electrolyte fuel cell produced in Examples 1 and 2 and Comparative Example 1. The measurement conditions were a cell temperature of 80 ° C., a fuel utilization rate of 70%, an oxidant utilization rate of 40%, a humidification temperature of 50 ° C., and the breakage of the ion conductive polymer electrolyte membrane after 200 hours and 1000 hours was visually confirmed. . As a result, breakage of the ion conductive polymer electrolyte membrane was confirmed in Comparative Example 1, whereas in Examples 1 and 2, there was no breakage of the ion conductive polymer electrolyte membrane and the durability was improved. (Table 2).

  Moreover, the film thickness of each ion conductive polymer electrolyte membrane in Examples 1 and 2 and Comparative Example 1 was measured. As a result, in Comparative Example 1, in the ion conductive polymer electrolyte membrane, the thickness of the portion in contact with the peripheral edge of the opening of the reinforcing membrane greatly changed with respect to the thickness of the other portions. On the other hand, in Examples 1 and 2, in the ion conductive polymer electrolyte membrane, the difference between the thickness of the portion in contact with the peripheral edge of the opening of the reinforcing membrane and the thickness of the other portion is different from the comparative example. It was small and it was confirmed that no thickness unevenness occurred (Table 2).

DESCRIPTION OF SYMBOLS 10 Polymer electrolyte fuel cell 20, 200 Membrane with reinforcing membrane-electrode assembly 30, 300 Catalyst layer with reinforcing membrane-electrolyte membrane laminate 1 Gasket 2 Separator 3 Ion conductive polymer electrolyte membrane 4 Catalyst layer 5 Conductive porous Base material 6 Electrode 7 Reinforcing film 71 Opening 74 Base material layer 75 Adhesive layer 73 Convex part 91 Thomson blade (cutting blade)

Claims (13)

Preparing an ion conductive polymer electrolyte membrane and a reinforcing membrane;
Forming a catalyst layer on both surfaces of the ion conductive polymer electrolyte membrane;
In the reinforcing film, by cutting from one side with a cutting blade, forming an opening for exposing the catalyst layer in the central portion;
The ion conductive polymer is disposed by pressing the reinforcing membrane so that the one surface of the reinforcing membrane faces at least one surface of the ion conductive polymer electrolyte membrane, and pressurizing from the other surface side of the reinforcing membrane. Adhering the reinforcing membrane to the electrolyte membrane;
With
The entire catalyst layer is disposed in the opening of the reinforcing membrane;
The manufacturing method of the catalyst layer-electrolyte membrane laminated body with a reinforcement film | membrane which the inner periphery of the said reinforcement film | membrane and the outer periphery of the said catalyst layer are contacting. The cutting blade is frame-shaped,
The step of forming the opening includes
Supporting the other side of the reinforcing membrane by a support plate;
Filling an elastically shrinkable porous body inside the cutting blade and bringing the cutting blade into contact with the one surface of the reinforcing membrane;
Moving the cutting blade in contact with the one surface toward the support plate;
The manufacturing method of the catalyst layer-electrolyte membrane laminated body with a reinforcement film | membrane of Claim 1 provided with these.   The method for producing a catalyst layer-electrolyte membrane laminate with a reinforcing membrane according to claim 1 or 2, wherein the reinforcing membrane has a Martens hardness based on ISO14577 smaller than that of the ion conductive polymer electrolyte membrane.   The catalyst layer with reinforcing membrane according to any one of claims 1 to 3, wherein the reinforcing membrane has an adhesive layer that adheres to the ion conductive polymer electrolyte membrane, and a base material layer that is provided on the adhesive layer. Manufacturing method of electrolyte membrane laminated body. A method for producing a reinforcing layer-attached catalyst layer-electrolyte membrane laminate according to any one of claims 1 to 4,
Forming a conductive porous substrate on the catalyst layer;
A method for producing a membrane-electrode assembly with a reinforcing membrane. Preparing an ion conductive polymer electrolyte membrane and a reinforcing membrane;
Forming a catalyst layer on both surfaces of the ion conductive polymer electrolyte membrane;
Forming a conductive porous substrate on the catalyst layer;
In the reinforcing film, by cutting from one side with a cutting blade, forming an opening for exposing the catalyst layer in the central portion;
The ion conductive polymer is disposed by pressing the reinforcing membrane so that the one surface of the reinforcing membrane faces at least one surface of the ion conductive polymer electrolyte membrane, and pressurizing from the other surface side of the reinforcing membrane. Adhering the reinforcing membrane to the electrolyte membrane;
With
The manufacturing method of the membrane-electrode assembly with a reinforcement film | membrane with which the opening peripheral part of the said reinforcement film | membrane is arrange | positioned on the surface on the opposite side to the said catalyst layer of the outer periphery part of the said electroconductive porous base material. A method for producing a membrane-electrode assembly with a reinforcing membrane according to claim 5 or 6,
Providing a gasket on the reinforcing membrane so as to surround the electrode including the catalyst layer and the conductive porous substrate;
Providing a separator on the electrode and the gasket;
A method for producing a polymer electrolyte fuel cell. An ion conductive polymer electrolyte membrane;
A catalyst layer formed on both surfaces of the ion conductive polymer electrolyte membrane;
It has an opening in the center, so as to expose the catalyst layer from the opening, and a reinforcing film one surface is adhered to at least one surface of the ion-conductive polymer electrolyte membrane,
With
The reinforcing film has a convex portion protruding to the other surface side at a peripheral edge portion of the opening,
The entire catalyst layer is disposed in the opening of the reinforcing membrane;
A catalyst layer-electrolyte membrane laminate with a reinforcing film, wherein an inner peripheral edge of the reinforcing film and an outer peripheral edge of the catalyst layer are in contact with each other.   The catalyst layer-electrolyte membrane laminate according to claim 8, wherein the reinforcing membrane has a Martens hardness based on ISO14577 lower than that of the ion conductive polymer electrolyte membrane.   The catalyst layer with a reinforcing membrane according to claim 8 or 9, wherein the reinforcing membrane has an adhesive layer that adheres to the ion conductive polymer electrolyte membrane, and a base material layer that is provided on the adhesive layer. Electrolyte membrane laminate. A catalyst layer-electrolyte membrane laminate with a reinforcing membrane according to any one of claims 8 to 10,
A conductive porous substrate formed on the catalyst layer;
A membrane-electrode assembly with a reinforcing membrane, comprising: An ion conductive polymer electrolyte membrane;
A catalyst layer formed on both surfaces of the ion conductive polymer electrolyte membrane;
A conductive porous substrate formed on the catalyst layer;
It has an opening in the center, so as to expose the catalyst layer from the opening, and a reinforcing film one surface is adhered to at least one surface of the ion-conductive polymer electrolyte membrane,
With
The reinforcing membrane has a convex portion projecting to the other surface side at the peripheral edge portion of the opening, and the peripheral edge portion of the opening is a surface opposite to the catalyst layer at the outer peripheral edge portion of the conductive porous substrate. A membrane-electrode assembly with a reinforcing membrane disposed above. A membrane-electrode assembly with a reinforcing membrane according to claim 11 or 12,
A gasket provided on the reinforcing membrane so as to surround a periphery of an electrode including the catalyst layer and the conductive porous substrate;
A separator provided on the electrode and the gasket;
A solid polymer fuel cell comprising:

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