JP2011159458A - Catalyst layer-electrolyte film laminate, membrane-electrode assembly, polymer electrolyte fuel cell, and method of manufacturing catalyst layer-electrolyte film laminate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a catalyst layer-electrolyte film laminate with gas leakage reliably prevented, capable of easily distinguishing an anode-side catalyst layer and a cathode-side catalyst layer in a simpler method, achieving cost reduction; and to provide a membrane-electrode assembly, a polymer electrolyte fuel cell, and a method of manufacturing the catalyst layer-electrolyte film laminate. <P>SOLUTION: The catalyst layer-electrolyte laminate 10 with an edge seal 4 includes an ionic conductive polymer electrolyte membrane 2, a catalyst layer 3 formed on each face of the ionic conductive electrolyte membrane, and a frame-like edge seal 4 with an opening at the center arranged on an outer peripheral edge of at least one of the catalyst layers 3. The edge seal 4, if there is only one, is colored; and if there are two, at least either of the edge seals 4 is colored. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

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

  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.

  This polymer electrolyte fuel cell uses an ion conductive polymer electrolyte membrane having ion conductivity, and a catalyst layer and a gas diffusion layer are sequentially laminated on both surfaces of the ion conductive polymer electrolyte membrane. And it has the structure which arrange | positioned the reinforcement film | membrane so that the circumference | surroundings of the electrode which consists of this catalyst layer and a gas diffusion layer may be enclosed, and also this was pinched | interposed with the separator (for example, refer patent document 1). 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.

However, in the polymer electrolyte fuel cell, a gap is formed between the reinforcing membrane and the electrode, and the ion conductive polymer electrolyte membrane corresponding to the gap is formed on either the electrode or the reinforcing membrane. It is in a non-pressed state. For this reason, when the ion conductive polymer electrolyte membrane is repeatedly wetted and dried and repeatedly expanded and contracted, stress is generated in the ion conductive polymer electrolyte membrane, resulting in fatigue. The molecular electrolyte membrane may be damaged. As a result, a gas leak occurs through the damaged portion of the ion conductive polymer electrolyte membrane, causing a problem that the fuel gas and the oxidant gas are mixed.
In addition, since the catalyst layer on the anode side and the catalyst layer on the cathode side used in a fuel cell generally have substantially the same appearance (shape and color), when assembling the membrane electrode assembly, In many cases, the direction of the side is combined with the wrong direction, which causes a problem in that the initial performance is impaired and the cost is increased due to a decrease in yield.

  Therefore, in the polymer electrolyte fuel cell described in Patent Document 2, an anode catalyst layer having a smaller area than the ion conductive polymer electrolyte membrane is provided on one surface of the ion conductive polymer electrolyte membrane. A cathode catalyst layer having a smaller area than the ion conductive polymer electrolyte membrane is formed on the other surface of the electrolyte membrane. Then, an identification mark made of a material having the same composition as the catalyst layer is formed in a region where the catalyst layer of the ion conductive polymer electrolyte membrane is not formed, and the anode side catalyst layer and the cathode side are formed by this identification mark. The catalyst layer can be discriminated.

  However, since the material generally used for the catalyst layer is very expensive, it is problematic in terms of manufacturing cost to form the identification mark using the catalyst layer that does not contribute to the battery performance as described above. . Also, since the method of identifying by the difference in shape is different from the color identification generally used in electric circuits, it is necessary to train manufacturing process personnel to identify the catalyst layer on the anode side and the catalyst layer on the cathode side. There is a problem from the viewpoint of workability.

JP-A-9-274926 JP 2007-179809 A

  The present invention is a catalyst layer-electrolyte membrane laminate that can reliably prevent gas leakage and can easily discriminate between a catalyst layer on the anode side and a catalyst layer on the cathode side by a simpler method, thereby reducing costs. It is another object of the present invention to provide a membrane electrode assembly and a polymer electrolyte fuel cell using the same, and a method for producing a catalyst layer-electrolyte membrane laminate.

  As a result of intensive studies to solve the above problems, the present inventor has found that the above problems can be solved by reinforcing the catalyst layer-electrolyte membrane laminate using a colored edge seal. The present invention has been completed based on such findings.

That is, the present invention provides a catalyst layer-electrolyte membrane laminate, a membrane electrode assembly, a polymer electrolyte fuel cell, and a catalyst layer-electrolyte laminate production method according to items 1 to 5 below.
Item 1. An ion conductive polymer electrolyte membrane, a catalyst layer formed on each side of the ion conductive polymer electrolyte membrane, and an outer peripheral edge of at least one of the two catalyst layers; A frame-shaped edge seal having an opening in the center, and when there is one edge seal, the edge seal is colored, and when there are two edge seals, at least one of the two edge seals is colored. An edge-sealed catalyst layer-electrolyte membrane laminate.
Item 2. Item 2. The catalyst layer-electrolyte membrane laminate according to Item 1, wherein the colored edge seal is transparent.
Item 3. Item 2. The catalyst layer-electrolyte membrane laminate according to Item 1, wherein the luminous transmittance of the colored edge seal is 20% or more.
Item 4. A membrane electrode assembly comprising: the catalyst layer with an edge seal-electrolyte membrane laminate, and a gas diffusion layer formed on the catalyst layer with an edge seal-electrolyte membrane laminate.
Item 5. Item 4. The membrane electrode assembly according to Item 4, a gasket installed so as to surround the periphery of the previous membrane electrode assembly,
And a separator installed so as to sandwich the membrane electrode assembly.

  The edge-sealed catalyst layer-electrolyte membrane laminate according to the present invention comprises an ion conductive polymer electrolyte membrane, a catalyst layer formed on both surfaces of the ion conductive polymer electrolyte membrane, and an opening in the center. And at least one surface of the catalyst layer-electrolyte membrane laminate comprising the ion conductive polymer electrolyte membrane and the catalyst layer (preferably, with the inner peripheral edge placed on the outer peripheral edge of the catalyst layer (preferably Edge seal bonded to both sides). When there is one edge seal, the edge seal is colored, and when there are two edge seals, at least one of the two edge seals is colored. When there are two edge seals, the color difference ΔE between the anode side and the cathode side of the edge seal is preferably 1.2 or more in the L * a * b * color system.

  The edge seal can take various configurations. For example, the edge seal has a base layer and a first resin layer that adheres to the catalyst layer-electrolyte membrane laminate provided on the base layer. Is preferred. Furthermore, it is more preferable that the base material layer has a gas barrier property that prevents permeation of fuel gas and oxidant gas. According to this configuration, the gas barrier base material layer is provided separately from the first resin layer for adhering to the catalyst layer-electrolyte membrane laminate, thereby reliably preventing fuel gas and oxidant gas from leaking. can do.

Further, the edge seal may be colored on either the anode side or the cathode side, and the color difference ΔE is preferably 1.2 or more so that the color difference of the edge seal in the adjacent positional relationship in the L * a * b * color system can be felt, Preferably, it may be 2.5 or more so that the color difference between the edge seals in the adjacent positional relationship can be felt. This makes it possible to easily distinguish the anode-side catalyst layer and the cathode-side catalyst layer.
In addition, the edge seal on the cathode side should be a L * a * b * color system and the value of a * should be larger on the plus side. As a result, the color of the edge seal on the cathode side becomes reddish and the same color as the “anode” color shown in the wiring identification table described in JISC6003. It becomes possible to recognize the catalyst layer on the anode side and the catalyst layer on the cathode side.

Further, the edge seal may be colored by either one or both of the resin layer and the base material, and may be colored to ensure the above color difference.
The entire edge seal need not be colored, and there may be markings that can be partially identified. It is sufficient that the anode-side catalyst layer and the cathode-side catalyst layer are colored so that they can be distinguished. For example, a mark for identifying the anode-side catalyst layer and the cathode-side catalyst layer is printed on the edge seal. May be. The mark may have the same shape or a different shape as long as it has a size that can be identified.

  According to this configuration, since the colors of the edge seals used on the anode side and the cathode side are different, the catalyst layer on the anode side and the catalyst layer on the cathode side can be distinguished by the color. Therefore, it is not necessary to separately form an identification mark using a catalyst layer that does not contribute to battery performance, and the cost can be reduced. In addition, the catalyst layer-electrolyte membrane laminate can be formed without changing the shape and size of the catalyst layer, and can correspond to various catalyst layers-electrolyte membrane laminates.

  The membrane electrode assembly 1 with an edge seal according to the present invention includes a gas diffusion layer on the above-described catalyst layer-electrolyte membrane laminate with an edge seal.

  Further, the membrane electrode assembly 2 with edge seal according to the present invention is obtained by laminating a gas diffusion layer on the catalyst layer formed on both surfaces of the ion conductive polymer electrolyte membrane, and on the outer peripheral edge of the gas diffusion layer. An edge seal is placed.

  According to this configuration, various members used for the membrane electrode assembly 2 can be fixed by the edge seal, and the fuel cell can be manufactured without worrying about the positional deviation at the time of manufacturing the fuel cell.

  The polymer electrolyte fuel cell according to the present invention includes a separator installed so as to sandwich the above-described membrane electrode assembly with an edge seal from both sides.

  According to the present invention, an anode-side catalyst layer and a cathode-side catalyst layer can be discriminated by a simpler method, and a cost-reduced catalyst layer-electrolyte membrane laminate with an edge seal, which can be used. The membrane electrode assembly, the polymer electrolyte fuel cell, and the method for producing the catalyst layer-electrolyte membrane laminate can be provided.

  The catalyst layer-electrolyte membrane laminate with an edge seal of the present invention is advantageous from the viewpoint of production cost because it is not necessary to form an identification mark using a catalyst layer that does not contribute to battery performance. In addition, since the catalyst layer on the anode side and the catalyst layer on the cathode side can be easily distinguished from each other, training of the manufacturing process worker is unnecessary, which is excellent in terms of workability.

  The catalyst layer-electrolyte membrane laminate with an edge seal of the present invention also has an advantage that gas leakage can be reliably prevented.

1 is a front sectional view showing an embodiment of a polymer electrolyte fuel cell according to the present invention. 1 is a plan view of a membrane electrode assembly with an edge seal according to the present invention. It is an expanded front sectional view which shows the detail of the outer periphery part of the membrane electrode assembly with an edge seal concerning this invention. It is explanatory drawing which shows the manufacturing method of the polymer electrolyte fuel cell which concerns on this invention. It is explanatory drawing which shows the manufacturing method of the catalyst layer-electrolyte membrane laminated body with an edge seal concerning this invention. It is front sectional drawing which shows other embodiment of the polymer electrolyte fuel cell which concerns on this invention. It is front sectional drawing which shows other embodiment of the polymer electrolyte fuel cell which concerns on this invention.

  Hereinafter, embodiments of a catalyst layer-electrolyte membrane laminate with an edge seal used for a polymer electrolyte fuel cell according to the present invention will be described with reference to the drawings.

  As shown in FIGS. 1 and 2, the solid polymer fuel cell 1 includes a catalyst layer-electrolyte membrane laminate 10 composed of an ion conductive polymer electrolyte membrane 2 and a catalyst layer 3, and the catalyst layer-electrolyte membrane laminate. An edge seal 4 extending outward from the body 10 and a conductive porous substrate 5 formed on the catalyst layer 3 are provided. The polymer electrolyte fuel cell 1 also includes a separator 7 that sandwiches them. Hereinafter, each member will be described in detail.

  The ion conductive polymer electrolyte membrane 2 has a rectangular shape in plan view, and catalyst layers 3 that are slightly smaller than the ion conductive polymer electrolyte membrane 2 are formed on both surfaces of the ion conductive polymer electrolyte membrane 2. . A material in which the catalyst layer 3 is formed on both surfaces of the ion conductive polymer electrolyte membrane 2 is referred to as a catalyst layer-electrolyte membrane laminate 10. Since the catalyst layer 3 is formed slightly smaller than the ion conductive polymer electrolyte membrane 2, the catalyst layer 3 is not formed on the outer peripheral edge 21 of the ion conductive polymer electrolyte membrane 2. As shown in FIG. 6, it can also be formed in the same size as the ion conductive polymer electrolyte membrane 2. In addition, it is preferable that the distance C (refer FIG. 3) from the outer periphery of the ion conductive polymer electrolyte membrane 2 to the outer periphery of the catalyst layer 3 is 0-10 mm. The thickness of the ion conductive polymer electrolyte membrane 2 is usually about 20 to 250 μm, preferably about 20 to 80 μm, and the thickness of the catalyst layer 3 is usually about 5 to 200 μm, preferably about 10 to 100 μm. It is.

  The edge seal 4 has a frame shape in which an opening 41 is formed at the center, a base material 42 that prevents permeation of fuel gas and oxidant gas used for power generation of the fuel cell, and the catalyst layer-electrolyte membrane laminate 10. And a resin layer 43 to be bonded. The edge seal 4 is bonded to the catalyst layer-membrane laminate 10 by the resin layer 43 being bonded to the catalyst layer-electrolyte membrane laminate 10. In the state where the edge seal 4 is bonded to the catalyst layer-electrolyte membrane laminate 10, the resin layer 43 at the inner peripheral edge of the edge seal 4 adheres to the outer peripheral edge 31 of the catalyst layer 3 and the opening of the edge seal 4. A portion excluding the outer peripheral edge 31 of the catalyst layer 3 from the portion 41 is exposed. The thickness of the base material 42 is preferably 5 to 500 μm, and the thickness of the resin layer 43 is preferably 1 to 500 μm. Moreover, it is preferable that the distance B (refer FIG. 3) from the outer periphery of the catalyst layer 3 to the inner periphery of the edge seal 4 shall be 0-20 mm.

  Further, the edge seal 4 is formed to be slightly larger than the ion conductive polymer electrolyte membrane 2, and adheres on the outer peripheral edge 21 of the electrolyte 2 and is ionized outside the ion conductive polymer electrolyte membrane 2. The outer peripheral edge portions 45 of the edge seals 4 protruding from the conductive polymer electrolyte membrane 2 are bonded to each other. The edge seal 4 can also be formed in the same size as the ion conductive polymer electrolyte membrane 2. The distance D (see FIG. 3) from the outer peripheral edge of the edge seal 4 to the outer peripheral edge of the ion conductive polymer electrolyte membrane 2 is preferably 0 to 150 mm. Thus, what adhered the edge seal | sticker 4 to the catalyst layer-electrolyte membrane laminated body 10 is equivalent to the catalyst layer-electrolyte membrane laminated body with an edge seal | sticker of this invention.

  A conductive porous substrate 5 having a rectangular shape in plan view is formed on the catalyst layer 3 exposed from the opening 41 of the edge seal 4. The distance A (see FIG. 3) from the outer peripheral edge of the conductive porous substrate 5 to the inner peripheral edge of the edge seal 4 is preferably 0 to 10 mm. In this way, the conductive porous substrate 5 is formed on the catalyst layer 3 to constitute the electrode E, and the electrode E formed on both surfaces of the ion conductive polymer electrolyte membrane 2 is membrane electrode bonded. It is called body 20. In addition, what the edge seal | sticker 4 adhere | attached on the membrane electrode assembly 20 is equivalent to the membrane electrode assembly with an edge seal of this invention.

  In the polymer electrolyte fuel cell 1, the separator 7 is installed on the electrode E. In the separator 7, a gas flow path 71 is formed in a region facing the conductive porous substrate 5.

  Next, the material of each component of the polymer electrolyte fuel cell 1 configured as described above will be described.

  The ion conductive polymer electrolyte membrane 2 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 membrane include perfluorosulfonic acid-based fluorine ion exchange resins, more specifically, perfluorocarbon sulfonic acid in which the C—H bond of the hydrocarbon-based ion exchange membrane is substituted with fluorine. -Based polymer (PFS-based 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 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 above-described hydrogen ion conductive polymer electrolyte membrane, an anion conductive polymer electrolyte membrane and a liquid substance-impregnated membrane are also included. Examples of the anion conductive electrolyte membrane include a hydrocarbon resin or a fluorine resin, and specific examples of the hydrocarbon resin include Aciplex (registered trademark) A201, 2111, 221 manufactured by Asahi Kasei Corporation, and Tokuyama. Neocepta (registered trademark) AM-1, AHA, etc. manufactured by Co., Ltd. may be mentioned, and examples of the fluorine-based resin may include Tosflex (registered trademark) IE-SF34 manufactured by Tosoh Corporation. Examples of the liquid substance-impregnated film include polybenzimidazole (PBI).

  The catalyst layer 3 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 2 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 edge seal 4 is composed of a base material 42 and a resin layer 43. The base material 42 is made of polyester, polyamide, polyimide, polymethyl tempen having barrier properties against water vapor, water, fuel gas, and oxidant gas, 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 resin layer 43 is preferably a polyolefin-based resin, for example, medium density polyethylene, high density polyethylene, linear low density polyethylene, ethylene-α-olefin copolymer, polypropylene, polybutene, polyisobutene, poisoisobutylene, Copolymer of ethylene and unsaturated carboxylic acid such as polybutadiene, polyisoprene, ethylene-methacrylic acid copolymer, or ethylene-acrylic acid copolymer, ethylene-ethyl acrylate copolymer, ionomer resin, ethylene-acetic acid Vinyl copolymers and the like can be used. In addition, acid-modified polyolefin resins and silane-modified polyolefin resins modified with them can be used. Among them, it is insulating to use polypropylene modified with unsaturated carboxylic acid or polyethylene modified with unsaturated carboxylic acid. Or it is preferable in terms of heat resistance.
The coloring agent for coloring the base material 42 or the resin layer 43 is not particularly specified, and can be easily colored by using a commercially available master batch for coloring plastics.

  Examples of the master batch for coloring plastics include a die color series manufactured by Dainichi Seika Kogyo Co., Ltd., a Polmax series manufactured by Sanyo Kako Co., Ltd., and a NIPPISUNCOLOUR series manufactured by Nippon Pigment Co., Ltd. The resin constituting these master batches is, for example, a graft-modified polyolefin, and the color is colored black with carbon black or the like.

  The conductive porous substrate 5 is well known, and various conductive porous substrates constituting a fuel electrode and an air electrode can be used, and fuel gas and oxidant gas, which are fuels, are efficiently applied to the catalyst layer 3. In order to supply, it consists of a porous conductive substrate. Examples of the porous conductive substrate include carbon paper and carbon cloth.

  The separator 7 may be any known conductive plate that is known and stable even in the environment within the fuel cell. In general, a carbon plate in which a gas flow path 71 is formed is used. In addition, the separator 7 is made of a metal such as stainless steel, and the surface of the metal is formed with a coating made of a conductive material such as chromium, a platinum group metal or oxide thereof, or a conductive polymer. 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 method for producing the above-described polymer electrolyte fuel cell 1 will be described with reference to the drawings. FIG. 4 is an explanatory view showing a method for producing the polymer electrolyte fuel cell 1 according to this embodiment.

  As shown in FIG. 4, an ion conductive polymer electrolyte membrane 2 made of the above-described material is prepared, and a catalyst layer forming transfer sheet 8 is placed on both surfaces of the ion conductive polymer electrolyte membrane 2 (see FIG. 4). 4 (a)). The catalyst layer forming transfer sheet 8 is one in which the transferred catalyst layer 3 is formed on a transfer substrate 81.

  Here, a method for producing 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 3 is formed on the transfer substrate 81 by coating and drying the catalyst layer forming composition so that the formed catalyst layer 3 has a desired thickness. If necessary, the composition for forming a catalyst layer is applied onto the transfer substrate 81 through a release layer. As a coating method of each composition for catalyst layer formation, well-known coating methods, such as screen printing, spray coating, die coating, and knife coating, can be mentioned. After coating the catalyst layer forming composition, the catalyst layer 3 is formed on the transfer substrate 81 by drying at a predetermined temperature and time. A drying temperature is about 40-100 degreeC normally, Preferably it is about 60-80 degreeC. Although depending on the drying temperature, the drying time is usually about 5 minutes to 2 hours, preferably about 10 minutes to 1 hour.

  Examples of the dispersion medium used in each of the catalyst layer forming compositions 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.

  Examples of the transfer base material 81 include polyimide, polyethylene terephthalate, polyparvanic acid aramid, polyamide (nylon), polysulfone, polyethersulfone, polyphenylene sulfide, polyether ether ketone, polyetherimide, polyarylate, and 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. Further, the transfer substrate 81 may be coated paper such as art paper, coated paper, lightweight coated paper, non-coated paper such as notebook paper, copy paper, etc. 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. 4, the description of the method for producing the polymer electrolyte fuel cell will be continued. The transfer sheet 8 for forming a catalyst layer prepared as described above is disposed so that the catalyst layer 3 faces the ion conductive polymer electrolyte membrane 2 (FIG. 4A), and a heat press is performed from the back side of the transfer sheet 8. Then, the catalyst layer 3 is transferred to the ion conductive polymer electrolyte membrane 2 to peel off the transfer substrate 81 of the transfer sheet 8 (FIG. 4B). In consideration of workability, it is preferable to simultaneously laminate the catalyst layer 3 on both surfaces of the ion conductive polymer electrolyte membrane 2, but the catalyst layer 3 can also be formed on each side. The pressure level of the heating press is usually about 0.5 to 20 MPa, preferably about 1 to 10 MPa in order to avoid transfer failure. Further, it is preferable to heat the pressing surface during this pressing operation in order to avoid transfer failure. The heating temperature is usually 200 ° C. or lower, preferably 150 ° C. or lower in order to avoid breakage, deformation, etc. of the ion conductive polymer electrolyte membrane 2. Thus, the catalyst layer-electrolyte membrane laminated body 10 is formed by forming the catalyst layer 3 on both surfaces of the ion conductive polymer electrolyte membrane 2.

  Next, the colored edge seal 4a and the non-colored edge seal 4b are attached to the catalyst layer-electrolyte membrane laminate 10 thus formed (FIG. 4C). The manufacturing method of the colored edge seal 4a will be described. First, a sheet-like base material 42 made of the above-described material is prepared. And the material of the resin layer 43 mentioned above is made into the melted state, and a commercially available coloring masterbatch is added to this and kneaded. In this way, the molten resin layer material to which the colorant has been added is extruded onto the base material 42 by the melt extrusion method, and the colored resin layer 43 is formed on the base material 42 to produce the colored edge seal 4a. .

  The non-colored edge seal 4b is produced by the same manufacturing method except that the colored edge seal 4a and the master batch for coloring are kneaded.

  The colored edge seal 4a and the non-colored edge seal 4b produced as described above are joined to the catalyst layer-electrolyte membrane laminate 10 (FIG. 4C). This process will be described in detail with reference to FIG. The edge seals of the colored edge seal 4a and the non-colored edge seal 4b made of the above-described materials are overlapped so that the resin layers 43 face each other, and the remaining three sides except for one side are bonded to each other. As a result, the two edge seals 4 form a bag body in which an adhesive portion is formed in a U-shape and the left side is open (FIG. 5A). Various known methods can be adopted as the bonding method. For example, the bonding can be performed by high frequency welding, hot air welding, hot plate welding, impulse welding, iron welding, ultrasonic welding, or the like.

  When the bag-shaped edge seal 4 is formed by the colored edge seal 4a and the non-colored edge seal 4b, an easy-removable region 44 is then formed at the center of each edge seal constituting the bag (FIG. 5B). )). The size of the easy removal region 44 is substantially the same as the portion excluding the outer peripheral edge 31 of the catalyst layer 3. The easy removal region 44 refers to a region that can be easily removed. For example, the easy removal region 44 can be formed by making a perforation in the outer peripheral edge or making a cut while leaving only a part. Thus, the catalyst layer-electrolyte membrane laminated body 10 is inserted into the bag body in which the easy-removal region 44 is formed from the left side where it is not bonded, and is moved to a predetermined position (FIG. 5C). This predetermined position refers to a position where a portion of the catalyst layer-electrolyte membrane laminate 10 excluding the outer peripheral edge 31 of the catalyst layer 3 faces the easy removal region 44. At this time, the anode side catalyst layer 3a is inserted so as to come to the colored edge seal 4a side.

  After the catalyst layer-electrolyte membrane laminate 10 is moved to a predetermined position, the perforation at the outer peripheral edge of the easy removal region 44 is cut and the easy removal region 44 is removed from each edge seal, so that the center of each edge seal 4 An opening 41 is formed in the part (FIG. 5D). When the easy removal regions 44 are thus removed from the edge seals 4 to form the openings 41, the catalyst layer 3 of the catalyst layer-electrolyte membrane laminate 10 is removed from the openings 41 except for the outer peripheral edge 31. It will be exposed. In this state, the resin layer 43 of the edge seal 4 is attached to the outside of the catalyst layer 3 of the catalyst layer-electrolyte membrane laminate 10 by adhering the remaining portion of the edge seal 4 that has not been adhered by a known method. While adhering to the peripheral edge part 31 and the outer peripheral edge part 21 of the ion conductive polymer electrolyte membrane 2, the edge seals 4 are also bonded to each other. Through the above steps, an electrolyte catalyst layer-electrolyte membrane laminate with an edge seal is completed (FIGS. 5E and 4C).

  Returning to FIG. 4, the description of the method for producing the polymer electrolyte fuel cell 1 will be continued. On the catalyst layer 3 exposed from the opening 41 of the catalyst layer-electrolyte membrane laminate with edge seal described above, the conductive porous substrate 5 is laminated by thermocompression bonding, and the membrane electrode assembly with edge seal is formed. Is completed (FIG. 4D). And the gasket 6 is arrange | positioned on the edge seal 4 so that the circumference | surroundings of the electrode E which consists of the catalyst layer 3 and the electroconductive porous base material 5 may be enclosed. Subsequently, the separator 7 is disposed on the conductive porous substrate 5 and the gasket 6 so that the gas flow path 71 faces the conductive porous substrate 5. Finally, the polymer electrode fuel cell 1 is completed by sandwiching the membrane electrode assembly with the separator 7 so that the conductive porous substrate 5 and the separator 7 are electrically connected (FIG. 4E). ).

  Further, as shown in FIG. 7, the inner peripheral edge of the edge seal 4 is adhered on the outer peripheral edge 51 of the conductive porous substrate 5, and the conductive porous substrate 5 is opened from the opening 41 of the edge seal 4. It can also comprise so that the part except the outer periphery part 51 may be exposed.

  Moreover, in the said embodiment, although the edge seal 4 is once used as the bag body and the manufacturing method of inserting the catalyst layer-electrolyte membrane laminated body 10 is employ | adopted, it is not specifically limited to this. For example, the colored edge seal 4a and the non-colored edge seal 4b in which the openings 41 are formed in advance are provided on both surfaces of the catalyst layer-electrolyte membrane laminate 10, and the resin layer 43 faces the catalyst layer-electrolyte membrane laminate 10. The edge seals 4 can be adhered to both sides of the catalyst layer-electrolyte membrane laminate 10 by a known adhesion method or the like, whereby a catalyst layer-electrolyte membrane laminate with edge seals can be produced.

  Moreover, in the said embodiment, although the material of the resin layer 43 is made into the melted state and the coloring masterbatch which consists of the material mentioned above is added and knead | mixed to this, it is not necessarily limited to this manufacturing method in particular. For example, a colored edge seal is obtained by using a base material 42 colored by a master batch as a base material, extruding a molten resin layer material onto the base material 42 by a melt extrusion method, and forming a resin layer 43 on the base material 42. 4a can be produced.

  In the above embodiment, the ion conductive polymer electrolyte membrane 2, the catalyst layer 3, and the conductive porous substrate 5 constituting the solid polymer fuel cell 1 are all described as rectangular in plan view. Is not limited, and for example, it may be circular in plan view.

  As described above, according to this embodiment, since only the anode side edge seal is colored, the anode side catalyst layer 3a and the cathode side catalyst layer 3b can be distinguished. In the present embodiment, the colored edge seal 4a and the non-colored edge seal 4b are simply adhered on the catalyst layer 3, and the shape of the catalyst layer 3 itself is changed or an extra catalyst layer is formed. Therefore, electrode portions that do not contribute to performance can 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 colored edge seal 4a is adhered only to the catalyst layer 3a on the anode side. However, the colored edge seal may be adhered only to the catalyst layer 3b on the cathode side. Colored edge seals 4a and 4b having different hues may be adhered to both the catalyst layer 3a and the catalyst layer 3b on the cathode side.

  The color difference and luminous transmittance of the edge seal were both measured using a spectrophotometer (manufactured by Shimadzu Corporation, trade name: “UV-3100PC”). That is, a resin to which a coloring master batch was added was coated on a substrate, and a test piece having a size of 50 mm × 50 mm was cut out from the resin and measured with a spectrophotometer.

  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 As the ion conductive polymer electrolyte membrane 2, NRE212CS (manufactured by Dupont) having a film thickness of 53 μm cut to a size of 63 × 63 mm was used.

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

  The catalyst layer forming transfer sheet 8 produced as described above is cut into a size of 53 × 53 mm, and the catalyst layer 3 is placed on the ion conductive polymer electrolyte membrane 2 side on both sides of the ion conductive polymer electrolyte membrane 2. The center was arranged so that it might face. And the catalyst layer 3 was formed in both surfaces of the ion conductive polymer electrolyte membrane 2 by heat-pressing on conditions of 135 degreeC, 5.0 MPa, and 150 second, and the catalyst layer-electrolyte membrane laminated body 10 was produced. The catalyst layer 3 has a thickness of 20 μm.

  Subsequently, a colored edge seal 4a was produced. As the base material layer 42 of the colored edge seal 4a, biaxially stretched polyethylene naphthalate (manufactured by Teijin Ltd., Teonex, film thickness: 12 μm) was used. Then, a black masterbatch (trade name: SPPM-8G680, manufactured by Sumika Color Co., Ltd.) colored with carbon black is added to the melted unsaturated carboxylic acid graft-modified polypropylene (Admer SF-741 manufactured by Sumitomo Chemical) and kneaded. The resin layer 43 was formed by extruding the obtained resin on the base material layer 42 with a thickness of 30 μm by a melt extrusion method. The colored edge seal 4a was cut to a size of 80 × 80 mm, and an opening 41 having a size of 50 × 50 mm was formed at the center. The non-colored edge seal 4b was produced by the same manufacturing method as the colored edge seal 4a except that black master batches were mixed. Then, the colored edge seal 4a is centered on the anode side of the catalyst layer-electrolyte membrane laminate 10, and the non-colored edge seal 4b is centered on the cathode side of the catalyst layer-electrolyte membrane laminate 10, and 130 ° C., 1.0 MPa, The colored edge seal 4a and the non-colored edge seal 4b were adhered to the electrolyte membrane-catalyst layer assembly 10 by hot pressing under conditions of 30 seconds to produce a catalyst layer-electrolyte membrane laminate with an edge seal.

  The luminous transmittance of the colored edge seal was 50%, and the color difference between the colored edge seal and the non-colored edge seal was 4.6.

DESCRIPTION OF SYMBOLS 1 Solid polymer fuel cell 2 Ion conductive polymer electrolyte membrane 3 Catalyst layer 31 Outer peripheral edge part 4 Edge seal 41 Opening part 42 Base material layer 43 Resin layer 4a Colored edge seal 4b Non-colored edge seal 5 Gas diffusion layer 51 Outside Peripheral part 6 Gasket 7 Separator 10 Catalyst-electrolyte membrane laminate 20 Membrane electrode assembly

Claims (5)

An ion conducting polymer electrolyte membrane;
Catalyst layers respectively formed on both surfaces of the ion conductive electrolyte membrane;
A frame-shaped edge seal installed on the outer peripheral edge of at least one of the two catalyst layers, and having an opening in the center;
In the case of one edge seal, the reinforcing layer is colored, and in the case of two edge seals, at least one of the two edge seals is colored.
Edge-sealed catalyst layer-electrolyte membrane laminate. The catalyst layer-electrolyte membrane laminate according to claim 1, wherein the colored edge seal is transparent. The catalyst layer-electrolyte membrane laminate according to claim 1, wherein the luminous transmittance of the colored edge seal is 20% or more. The catalyst layer with an edge seal-electrolyte membrane laminate and the gas diffusion layer formed on the catalyst layer with an edge seal-electrolyte membrane laminate,
A membrane electrode assembly comprising: A membrane electrode assembly according to claim 4;
A gasket installed to surround the periphery of the membrane electrode assembly;
A separator installed to sandwich the membrane electrode assembly;
A solid polymer fuel cell comprising:

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