JP2010033731A - Manufacturing method of catalyst layer for solid polymer fuel cell and catalyst layer-electrolyte film laminate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a simple manufacturing method of a catalyst layer with swelling or generation of cracks of an electrolyte film restrained, and capable of exerting superb cell performance. <P>SOLUTION: The manufacturing method of the catalyst layer for a solid polymer fuel cell by coating a paste composition for forming a catalyst layer containing catalyst particles, ion-conductive electrolyte and a dispersant directly on at least one of the faces of an ion-conductive electrolyte film and drying the same includes (1) a process of coating the paste composition for forming a catalyst layer on at least one of the faces of the ion-conductive electrolyte film, and (2) a process of forming a catalyst layer by decompressing and drying at ambient temperatures the coated paste composition for forming the catalyst layer. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

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

  A fuel cell is a system in which a catalyst layer is disposed on both sides of an electrolyte membrane, and power is generated by an electrochemical reaction between hydrogen and oxygen. Only water is generated during power generation, and unlike conventional internal combustion engines, it does not generate environmental load gas such as carbon dioxide. Therefore, it is attracting attention as a next-generation clean energy system.

  Among the polymer polymer fuel cell catalyst layer-electrolyte membrane laminate constituting the polymer electrolyte fuel cell, the catalyst layers are arranged on both sides of the electrolyte membrane (that is, catalyst layer / electrolyte membrane / catalyst layer) The one having a structure is called a three-layer MEA, and an electrode substrate is disposed on each side of the three-layer MEA (that is, an electrode substrate / catalyst layer / electrolyte membrane / catalyst layer / electrode base). The material layer structure) is called a five-layer MEA.

  In order to improve the performance of the polymer electrolyte fuel cell, the optimization of the structure of the catalyst layer-electrolyte membrane laminate is the key. Among these, since the catalyst layer plays a central role in the battery reaction, high performance is being actively promoted. This catalyst layer is usually produced by applying and drying a catalyst layer forming paste composition containing catalyst particles, an ion conductive polymer electrolyte and a solvent on a substrate or the like. As a method for producing a catalyst layer-electrolyte membrane laminate, for example, a method of directly applying a paste composition for forming a catalyst layer to an electrolyte membrane is common.

  However, in this direct coating method, when a perfluorosulfonic acid electrolyte membrane such as a Nafion (registered trademark) membrane generally used as an electrolyte membrane is used, (1) a solvent in the paste composition for forming a catalyst layer For this reason, there are problems such as significant swelling of the electrolyte membrane, and (2) cracks in the dried catalyst layer. Since cracks in the catalyst layer cause a decrease in battery performance, it is necessary to avoid the generation of cracks as much as possible.

  As a method for avoiding swelling of the electrolyte membrane, for example, a mask film partially cut out corresponding to the electrode shape is provided with a weakening line corresponding to the electrode shape on one surface of the electrolyte membrane. Is applied to the other surface of the electrolyte membrane by thermocompression bonding, and then a cathode layer forming paste composition is applied using a mask film partially cut out corresponding to the electrode shape as a mask. A method of forming a second catalyst layer by forming a layer, further peeling off a mask film surrounded by a weakening line, and applying an anode layer forming paste composition on the exposed electrolyte membrane (Patent Document 1) )It has been known.

  As a method for avoiding the occurrence of cracks, for example, a method in which the catalyst ink surface and the base sheet surface are exposed to different humidity atmospheres and dried in a state where the shrinkage rates of the two are substantially the same (Patent Document 2), catalyst layer formation After applying the paste composition on the electrode substrate, the electrode substrate of the plurality of fuel cells is held at substantially the same amount of water, and then dried under vacuum to remove moisture (Patent Document 3), etc. Proposed.

  However, in the manufacturing method described in Patent Document 1, a mask film, a part of which is cut out in accordance with the electrode shape, is attached to one surface of the electrolyte membrane by thermocompression bonding. The portion in contact with the mask film is dented, and the electrolyte membrane is damaged. In addition, a part of the styrene-ethylene-butadiene copolymer that is contained in the tack resin layer constituting the mask film and has low heat resistance and acid resistance is transferred to the second catalyst layer, and battery characteristics such as long-term durability are obtained. Adversely affect

  Further, in the drying method described in Patent Document 2, the catalyst ink surface and the base sheet surface are exposed to different humidity atmospheres, so that a special and complicated drying apparatus is required. In addition, this method makes it difficult to determine a state in which the shrinkage rates are substantially matched, has a problem in reproducibility, and cannot produce a desired catalyst layer industrially.

In the drying method described in Patent Document 3, it is necessary to adjust the amount of water by placing it under high-temperature and high-humidity conditions, and then stop the supply of water vapor, and then perform rapid vacuum drying at 0.1 to 0.5 kPa . Therefore, the fine voids (voids having a pore diameter of 10 nm to 200 nm) in the catalyst layer structure are closed by rapid vacuum drying (for example, the void ratio is about 5%), and the battery performance is deteriorated. The catalyst layer thus produced has a problem.
JP 2006-120433 A Japanese Patent Laid-Open No. 2004-259509 JP 2005-302538 A

  An object of the present invention is to provide a simple method for producing a catalyst layer in which the swelling of an electrolyte membrane and the generation of cracks are suppressed, mechanical damage is not given to the electrolyte membrane, and good battery performance can be exhibited.

  The inventors of the present invention have made extensive studies to solve the above problems. As a result, when manufacturing a catalyst layer from the paste composition for forming a catalyst layer, it was found that a desired catalyst layer with less swelling and cracking of the electrolyte membrane can be easily manufactured by drying under specific conditions. The present invention has been completed based on such findings.

The present invention provides a method for producing a catalyst layer, a catalyst layer-electrolyte membrane laminate, and an electrolyte membrane-electrode assembly according to items 1 to 7 below.
Item 1. A catalyst layer forming paste composition containing catalyst particles, an ion conductive electrolyte and a dispersion medium is directly applied to at least one surface of the ion conductive electrolyte membrane, and dried to form a catalyst layer for a polymer electrolyte fuel cell. A method of manufacturing comprising:
(1) applying the catalyst layer forming paste composition to at least one surface of the ion conductive electrolyte membrane; and (2) drying the applied catalyst layer forming paste composition at room temperature under reduced pressure. The manufacturing method of a catalyst layer provided with the process of forming a catalyst layer.
Item 2. A method for producing a catalyst layer for a polymer electrolyte fuel cell by directly applying and drying a catalyst layer forming paste composition containing catalyst particles, an ion conductive electrolyte and a dispersion medium on both surfaces of an ion conductive electrolyte membrane Because
(1) A step of applying the catalyst layer forming paste composition to one surface of the ion conductive electrolyte membrane,
(2) forming a catalyst layer by drying the paste composition for forming a catalyst layer applied in (1) above under reduced pressure at room temperature;
(3) applying the catalyst layer forming paste composition to the other surface of the ion conductive electrolyte membrane; and (4) applying the catalyst layer forming paste composition applied in (3) above at room temperature. Item 2. The method for producing a catalyst layer according to Item 1, comprising a step of drying under reduced pressure to form a catalyst layer.
Item 3. In applying the catalyst layer forming paste composition on one surface of the ion conductive electrolyte membrane and forming the catalyst layer, a release-treated base film is disposed on the other surface of the electrolyte membrane. Item 3. The method for producing a catalyst layer according to Item 1 or Item 2.
Item 4. When the catalyst layer forming paste composition is applied to the other surface of the ion conductive electrolyte membrane having the catalyst layer formed on one surface and the catalyst layer is formed, the surface is separated from the surface on which the catalyst layer is formed. Item 3. The method for producing a catalyst layer according to Item 2, wherein the mold-treated substrate film is disposed.
Item 5. When the catalyst layer forming paste composition is applied to the other surface of the ion conductive electrolyte membrane having the catalyst layer formed on one surface and the catalyst layer is formed, the surface is separated from the surface on which the catalyst layer is formed. Item 3. The method for producing a catalyst layer according to Item 2, wherein the mold-treated conductive porous substrate is disposed.
Item 6. Item 6. A catalyst layer-electrolyte membrane laminate produced by the method according to any one of Items 1 to 5.
Item 7. Item 7. An electrolyte membrane-electrode assembly in which a conductive porous substrate is disposed on the catalyst layer-electrolyte membrane laminate according to Item 6.
Item 8. Item 8. A polymer electrolyte fuel cell comprising the electrolyte membrane-electrode assembly according to Item 7.

  The production method of the present invention is a method for producing a catalyst layer for a fuel cell, wherein the paste composition for forming a catalyst layer containing catalyst particles, an ion conductive electrolyte, and a dispersion medium is applied on the electrolyte membrane, and then at room temperature. A step of drying under reduced pressure.

Catalyst Layer Forming Paste Composition The catalyst layer forming paste composition of the present invention contains, for example, catalyst particles, an ion conductive electrolyte, and a dispersion medium.

  Known or commercially available catalyst particles can be used, and are not particularly limited as long as they cause a fuel cell reaction at the anode or cathode of the fuel cell. For example, platinum, a platinum alloy, a platinum compound, etc. are mentioned. Examples of the platinum alloy 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. In general, the catalyst particles when used as the cathode catalyst layer are platinum, and the catalyst particles when used as the anode catalyst layer are the alloys described above.

  The catalyst particles may be so-called catalyst-supported carbon powder in which catalyst fine particles are supported on carbon powder. The average particle size of the catalyst-supported carbon powder is usually about 10 to 100 nm, preferably about 20 to 80 nm, and most preferably about 40 to 50 nm. The carbon particles constituting the catalyst-supported carbon powder are not particularly limited, and examples thereof include carbon black such as channel black, furnace black, ketjen black, acetylene black, and lamp black, graphite, activated carbon, carbon fiber, and carbon nanotube. . These may be used alone or in combination of two or more.

  The ion conductive polymer electrolyte may be a hydrogen ion conductive one, and a known or commercially available one can be used. Examples thereof include perfluorosulfonic acid-based fluorine ion exchange resins. Moreover, by introducing a fluorine atom having a high electronegativity, it is chemically very stable, the degree of dissociation of the sulfonic acid group is high, and good hydrogen ion conductivity can be realized. Specific examples of such a hydrogen ion conductive polymer electrolyte include, for example, “Nafion” manufactured by DuPont, “Flemion” manufactured by Asahi Glass Co., Ltd., “Aciplex” manufactured by Asahi Kasei Co., Ltd., and Gore. “Gore Select” manufactured by the company can be used. Examples of the hydrocarbon electrolyte ion conductive polymer electrolyte include sulfonation (polystyrene-block-poly (ethylene-ran-butylene) -block-polystyrene) manufactured by Aldrich.

  Note that “-ran-” is a connection symbol used for naming a random type copolymer (copolymer). For example, “-poly- (A -Ran-B) ". Similarly, “-block-” is a connection symbol indicating a block-type copolymer.

  The ion conductive polymer electrolyte is not impregnated with a liquid substance (an acidic substance such as phosphoric acid or sulfuric acid).

  The thickness of the electrolyte membrane is usually about 10 μm to 500 μm, preferably about 15 μm to 300 μm, more preferably about 20 to 150 μm.

  A known or commercially available dispersion medium can be used. Examples thereof include various alcohols, various ethers, various dialkyl sulfoxides, water, or a mixture thereof. Among these, alcohols having 1 to 4 carbon atoms are preferable, and specific examples include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutanol, and t-butanol. Of these, 2-propanol is most preferred.

  In the present invention, in particular, the main dispersion medium contained in the dispersion medium is preferably one or more selected from the group consisting of 1-propanol, 2-propanol, 1-butanol, t-butanol, and the like. More preferred are 2-propanol, 1-butanol and t-butanol.

  In the present invention, the main dispersion medium is a dispersion medium contained in the largest amount among all the dispersion media contained in the paste composition, preferably 25% by weight or more, more preferably 50% by weight in the total dispersion medium. A dispersion medium containing at least%.

  The ratios of the catalyst particles, the ion conductive electrolyte, and the dispersion medium contained in the catalyst layer forming paste composition of the present invention are not limited and can be appropriately selected within a wide range.

  For example, with respect to 1 part by weight of catalyst particles (in the case of catalyst-supported carbon powder, 1 part by weight of the catalyst-supported carbon powder), the ion conductive electrolyte is 0.1 to 2 parts by weight (preferably 0.2 to 1 part by weight). Part) and about 5 to 35 parts by weight (preferably 10 to 25 parts by weight) of the dispersion medium.

  The paste composition for forming a catalyst layer is produced by mixing the catalyst particles, the ion conductive electrolyte, and the dispersion medium. The mixing order of the catalyst particles, the ion conductive electrolyte, and the dispersion medium is not particularly limited. For example, the catalyst particle forming paste composition can be prepared by mixing the catalyst particles, the ion conductive electrolyte, and the dispersion medium sequentially or simultaneously to disperse the catalyst particles.

  The catalyst layer forming paste composition of the present invention may contain other known additives as long as the effects of the present invention are not impaired.

Production method of catalyst layer The production method of the present invention comprises a step of drying under reduced pressure at room temperature when producing a catalyst layer for a fuel cell using the paste composition for forming a catalyst layer.

  In this drying step, for example, the catalyst layer forming paste composition is applied to a known ion conductive electrolyte membrane (an ion conductive electrolyte membrane not impregnated with a liquid substance) so as to have a desired layer thickness. And then dry.

  The method for applying the catalyst layer forming paste composition is not particularly limited, and examples thereof include knife coaters, bar coaters, sprayers, dip coaters, spin coaters, roll coaters, die coaters, curtain coaters, and screen printing. General methods can be applied.

  After applying such a paste composition for forming a catalyst layer, a catalyst layer is formed on the ion conductive electrolyte membrane through the drying step of the present invention. In the drying process of the present invention, it is essential to carry out vacuum drying at room temperature. Thereby, the catalyst layer can be dried at an appropriate drying speed without damaging the ion conductive electrolyte membrane. As a result, when the catalyst layer is formed on the other side, the catalyst layer that exhibits excellent battery performance is prevented from being peeled off from the ion conductive electrolyte membrane due to the transfer of the catalyst layer to the underlying base film. Can be manufactured. Also, this process does not require special equipment and complicated processes.

  Specifically, for example, an ion conductive electrolyte membrane coated with the catalyst layer forming paste composition is allowed to stand in a drying device such as a vacuum dryer, and then the inside of the drying device is decompressed at room temperature. By doing so, it may be dried. What is necessary is just to deaerate the inside of an apparatus continuously or intermittently at the time of pressure reduction as needed.

  Furthermore, if necessary, a very small amount of the dispersion medium remaining in the catalyst layer may be reliably removed by further reducing the pressure after the drying step.

  The pressure during drying is 10 to 60 hPa, preferably 15 to 45 hPa. In particular, in the present invention, in the drying step, it is preferable to finally reduce the pressure to the saturation vapor pressure or less of the main dispersion medium contained in the catalyst layer forming paste composition. Further, the degree of decompression can be reduced stepwise to prevent bumping of the main dispersion medium. For example, when the main dispersion medium is 2-propanol, the pressure is preferably reduced to 44 hPa (± 4 hPa) or less at 20 ° C. Similarly, in the case of 1-propanol, the pressure is reduced to 20 hPa (± 4 hPa) or less at 20 ° C. In the case of butanol, the pressure is preferably reduced to 5.8 hPa (± 4 hPa) or less at 20 ° C., and in the case of t-butanol, the pressure is reduced to 41 hPa (± 4 hPa) or less at 20 ° C. Thereby, the residual dispersion medium in the catalyst layer can be removed more completely. A dispersion medium having a vapor pressure of less than 4 hPa is not preferable because it makes it difficult to prepare a catalyst layer forming paste composition and to form a catalyst layer by coating.

  The drying time is determined depending on the pressure during drying, the type of dispersion medium, etc., but is usually about 1 to 120 minutes, preferably about 5 to 60 minutes, more preferably about 15 to 30 minutes. .

  Although the temperature at the time of drying is not limited, normal temperature is preferable, for example, about 15 to 30 ° C, and more preferably about 20 to 25 ° C.

  The thickness of the catalyst layer is not limited. For example, the thickness is usually about 5 μm to 120 μm, preferably about 10 μm to 50 μm, more preferably about 15 μm to 30 μm.

  The content of catalyst particles in the catalyst layer (in the case of catalyst-supported carbon powder, the content of the catalyst-supported carbon powder) is usually about 10 to 90% by weight, preferably about 40 to 80% by weight, based on the total amount of the catalyst layer. It is.

  The catalyst layer of the present invention can be used in, for example, a solid polymer fuel cell, a direct fuel fuel cell, and a solid alkaline fuel cell using an electrolyte membrane made of a polymer as the electrolyte membrane.

  In the catalyst layer-electrolyte membrane laminate of the present invention, the catalyst layer obtained by the production method of the present invention is formed on one or both surfaces of the electrolyte membrane.

  The electrolyte membrane (catalyst layer-electrolyte membrane laminate) on which the catalyst layer of the present invention is laminated is, for example, at room temperature after applying the catalyst layer forming paste composition on one surface of the ion conductive electrolyte membrane. Manufactured by vacuum drying. By repeating this operation once or twice, a catalyst layer-electrolyte membrane laminate in which the catalyst layer surface is laminated on both surfaces of the ion conductive electrolyte membrane is produced.

  At this time, in the step of forming the catalyst layer on one surface, by disposing a release film as a base material on the other surface of the surface on which the catalyst layer is formed, Swelling can be suppressed. In addition, in the step of forming the catalyst layer on the other surface of the ion conductive electrolyte membrane having the catalyst layer formed on one surface, the base film that has been subjected to a release treatment as a base material used as an underlay is used as the catalyst. It is preferable to arrange on the side that contacts the layer. Thereby, the effect which suppresses peeling of the catalyst layer from an ion conductive electrolyte membrane is acquired.

  The material for the base film is not particularly limited as long as it can be released from the mold and is excellent in handleability and economy. Moreover, the base film itself may have releasability.

  For example, polymer films such as polyimide, polyethylene terephthalate, polypalvanic acid aramid, polyamide (nylon), polysulfone, polyethersulfone, polyphenylene sulfide, polyether ether ketone, polyetherimide, polyarylate, polyethylene naphthalate Can do.

  The base film is made of ethylene tetrafluoroethylene copolymer (ETFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroperfluoroalkyl vinyl ether copolymer (PFA), polytetrafluoroethylene ( A heat resistant resin such as PTFE) can also be used.

  Furthermore, the base film 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 mold release treatment may be performed, for example, by applying a wax on the base film. Specific examples of the wax include petroleum wax, plant wax, animal wax, mineral wax, and synthetic wax. The wax used in the present invention includes, for example, esters of C ₁₆ -C ₃₂ fatty acids and alcohols. In the present invention, these waxes are used singly or in combination of two or more.

  Further, the mold release treatment may be performed by coating a known fluorine resin, silicone or the like.

  When the mold release treatment is performed on the base film, the wax, fluorine resin, silicone or the like is preferably applied according to a known method so as to have a desired layer thickness. Moreover, in order to make an application | coating operation | work easy, you may melt | dissolve in a suitable solvent or disperse | distribute to a suitable dispersion medium, and you may use it in the form of a solution or an emulsion liquid. The coating method is not particularly limited, and general methods such as knife coater, bar coater, spray, dip coater, spin coater, roll coater, die coater, curtain coater, and screen printing can be applied. Moreover, you may extrude the component which comprises a release layer on a base film by a well-known method.

  In the step of applying the paste composition for forming a catalyst layer on the other surface of the ion conductive electrolyte membrane having the catalyst layer formed on one surface, the side that contacts the catalyst layer as a base material used as an underlay A conductive porous substrate may be disposed on the substrate. Thereby, the process of arrange | positioning a conductive porous base material in a catalyst layer-electrolyte membrane laminated body, and forming an electrode-electrolyte membrane assembly can be shortened.

  A well-known thing can be utilized for a conductive porous base material, For example, carbon paper, carbon felt, carbon cloth, etc. which consist of conductive carbon paper can be used. Specific examples include carbon paper “TGP-H” series manufactured by Toray Industries, Inc., carbon felt “SIGRATETE GDL” series manufactured by SGL Carbon Japan.

  The film thickness of the conductive porous substrate is usually about 20 to 400 μm, preferably about 100 to 300 μm.

  According to the present invention, the swelling of the electrolyte membrane can be suppressed. As a result, the occurrence of cracks in the catalyst layer can be suppressed, and a uniform and homogeneous catalyst layer can be produced without peeling. The catalyst layer can exhibit good battery performance. Moreover, the manufacturing method of the present invention does not require special equipment and complicated processes.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. In addition, this invention is not limited to a following example.

Example 1
Platinum-supported carbon (Pt: 45.6 wt%, Tanaka Kikinzoku Kogyo Co., Ltd., TEC10E50E) 1 part by weight and 5 wt% electrolyte solution (5 wt% Nafion solution, manufactured by Aldrich, dispersion medium “water: 1-propanol: 10 parts by weight of 2-propanol = 1: 1.5: 2 (weight ratio) ”was added to 10 parts by weight of 2-propanol, and mixed and dispersed to prepare a paste composition for forming a catalyst layer.

  A base film was disposed on one surface of an ion conductive electrolyte membrane (“Nafion NRE 212CS” (registered trademark) sheet, 50 μm, manufactured by Dupont). A release-treated film (“Purex” (registered trademark, 50 μm, manufactured by Teijin DuPont)) is disposed as a base film, and the catalyst layer-forming paste composition on the other side is dried with a blade coater. After coating so that the thickness of the layer was 100 μm, it was allowed to stand in a vacuum dryer.

  Next, using a vacuum pump, the desiccator was depressurized to 40 hPa over 5 minutes, and the state of 40 hPa was maintained for 10 minutes, whereby the catalyst layer forming paste composition was dried to produce the catalyst layer of the present invention. . The temperature in the vacuum dryer was about 25 ° C.

  Thus, the base film was arrange | positioned so that the base film may contact | connect the ion conductive electrolyte membrane in which the catalyst layer was formed in one surface, and the surface which a catalyst layer opposes. After disposing a release-treated film ("Purex" (registered trademark, 50 μm, manufactured by Teijin DuPont)) as a base film, the base film on the surface of the electrolyte membrane where the catalyst layer is not formed is peeled off, By repeating the same operation as described above, a catalyst layer was formed to produce a catalyst layer-electrolyte membrane laminate of the present invention, and the thickness of the catalyst layer after drying was 25 μm on both sides.

Example 2
A catalyst layer-electrolyte membrane laminate of the present invention was produced in the same manner as in Example 1 except that the pressure in the vacuum dryer was reduced to 30 hPa over 5 minutes and the state of 30 hPa was maintained for 30 minutes. The thickness of the catalyst layer after drying was 25 μm on both sides.

Example 3
A catalyst layer-electrolyte membrane laminate of the present invention was produced in the same manner as in Example 1 except that the pressure in the vacuum dryer was reduced to 50 hPa over 5 minutes and the state of 50 hPa was maintained for 30 minutes. In addition, the thickness of the catalyst layer after drying was 25 μm on both sides.

Comparative Example 1
A paste composition for forming a catalyst layer was formed without using a base film. However, formation of a catalyst layer on the electrolyte membrane was difficult due to swelling of the electrolyte membrane.

Comparative Example 2
Example 1 except that a polyethylene terephthalate film that has not been subjected to mold release treatment is used instead of the substrate film that has been subjected to mold release treatment, and the catalyst composition for forming a catalyst layer is dried in air for 30 minutes. Similarly, a catalyst layer-electrolyte membrane laminate was produced. A part of the dried catalyst layer was transferred to a polyethylene terephthalate film and was peeled off from the electrolyte membrane.

Evaluation test About the catalyst layer-electrolyte membrane laminated body manufactured by Examples 1-3 and Comparative Examples 1-2, formation of a catalyst layer, swelling suppression of an electrolyte membrane, and crack suppression of a catalyst layer were investigated.

The evaluation criteria are as follows.
Formation of a catalyst layer;
○: The catalyst layer could be formed on the electrolyte membrane. ×: Swelling suppression of the electrolyte membrane where the catalyst layer could not be formed on the electrolyte membrane;
○: Swelling of electrolyte membrane was suppressed ×: Crack suppression of catalyst layer where swelling of electrolyte membrane was not suppressed;
○: Cracks in the catalyst layer were suppressed ×: Overall judgment that cracks in the catalyst layer were not suppressed;
○: Pass ×: Fail The results are shown in Table 1.

Claims (8)

A catalyst layer forming paste composition containing catalyst particles, an ion conductive electrolyte and a dispersion medium is directly applied to at least one surface of the ion conductive electrolyte membrane, and dried to form a catalyst layer for a polymer electrolyte fuel cell. A method of manufacturing comprising:
(1) applying the catalyst layer forming paste composition to at least one surface of the ion conductive electrolyte membrane; and (2) drying the applied catalyst layer forming paste composition at room temperature under reduced pressure. The manufacturing method of a catalyst layer provided with the process of forming a catalyst layer. A method for producing a catalyst layer for a polymer electrolyte fuel cell by directly applying and drying a catalyst layer forming paste composition containing catalyst particles, an ion conductive electrolyte and a dispersion medium on both surfaces of an ion conductive electrolyte membrane Because
(1) A step of applying the catalyst layer forming paste composition to one surface of the ion conductive electrolyte membrane,
(2) forming a catalyst layer by drying the paste composition for forming a catalyst layer applied in (1) above under reduced pressure at room temperature;
(3) applying the catalyst layer forming paste composition to the other surface of the ion conductive electrolyte membrane; and (4) applying the catalyst layer forming paste composition applied in (3) above at room temperature. The method for producing a catalyst layer according to claim 1, comprising a step of forming a catalyst layer by drying under reduced pressure.   In applying the catalyst layer forming paste composition on one surface of the ion conductive electrolyte membrane and forming the catalyst layer, a release-treated base film is disposed on the other surface of the electrolyte membrane. The manufacturing method of the catalyst layer of Claim 1 or Claim 2.   When the catalyst layer forming paste composition is applied to the other surface of the ion conductive electrolyte membrane having the catalyst layer formed on one surface and the catalyst layer is formed, the surface is separated from the surface on which the catalyst layer is formed. The manufacturing method of the catalyst layer of Claim 2 with which the base film by which the mold process was carried out is arrange | positioned.   When the catalyst layer forming paste composition is applied to the other surface of the ion conductive electrolyte membrane having the catalyst layer formed on one surface and the catalyst layer is formed, the surface is separated from the surface on which the catalyst layer is formed. The manufacturing method of the catalyst layer of Claim 2 with which the electroconductive porous base material by which the mold process was carried out is arrange | positioned.   A catalyst layer-electrolyte membrane laminate produced by the method according to claim 1.   An electrolyte membrane-electrode assembly in which a conductive porous substrate is disposed on the catalyst layer-electrolyte membrane laminate according to claim 6.   A polymer electrolyte fuel cell comprising the electrolyte membrane-electrode assembly according to claim 7.