JP2010080169A - Catalyst transfer film for polymer electrolyte fuel cell, catalyst layer-electrolyte membrane laminate obtained by using it, and polymer electrolyte fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a catalyst transfer film for a polymer electrolyte fuel cell capable of manufacturing a catalyst layer-electrolyte membrane laminate free from distortion in uniform transferring property, and to provide a catalyst layer-electrolyte membrane laminate obtained by using this, and the polymer electrolyte fuel cell. <P>SOLUTION: The catalyst transfer film for the polymer electrolyte fuel cell is such that (1) a catalyst layer is formed on a film substrate; (2) at least two through holes are installed on the surface on the side not coming in contact with the catalyst layer of the film substrate; (3) the through hole has a diameter of 1-100 μm; and (4) the shortest distance between the through holes is 1 cm or less. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a novel catalyst transfer film for a polymer electrolyte fuel cell, a catalyst layer-electrolyte membrane laminate obtained by using the catalyst transfer film, and a polymer electrolyte fuel cell.

  The catalyst layer-electrolyte membrane laminate used in the polymer electrolyte fuel cell is a hydrogen conductive polymer obtained by applying a catalyst layer forming composition to a base film and drying it. It arrange | positions on both surfaces of an electrolyte membrane, and is obtained by performing a hot press.

  However, in the above method, when the catalyst transfer film is transferred onto the electrolyte membrane, there is a risk that air or bubbles such as a solvent that has not been completely removed are pressed between the electrolyte membrane and the catalyst layer. As a result, the pressure is applied non-uniformly, so that transfer failure occurs when the catalyst layer is peeled from the base film, and a uniform catalyst layer surface cannot be obtained. In addition, since air bubbles are trapped, uniform pressure is not applied to the electrolyte membrane and the catalyst layer, so that the catalyst layer-electrolyte membrane laminate is distorted.

  In a state where transfer failure or distortion occurs in the catalyst layer-electrolyte membrane laminate, the transferred catalyst layer surface becomes non-uniform. For this reason, the adhesion with other layers such as a gas diffusion layer subsequently formed on the catalyst layer is poor, and the performance of the fuel cell may be deteriorated.

Therefore, conventionally, a method of pressing the catalyst transfer film and the electrolyte membrane while stretching them one by one or a method of transferring with a roller (for example, see Patent Document 1) have been taken. However, the former method is too time-consuming and not suitable for mass production, and the latter method has a problem that the apparatus becomes large.
Japanese Patent Laid-Open No. 10-64574

  The present invention has been made in order to solve the above-mentioned problems. A catalyst transfer film for a polymer electrolyte fuel cell capable of producing a catalyst layer-electrolyte membrane laminate with uniform transferability and no distortion, and the same An object of the present invention is to provide a catalyst layer-electrolyte membrane laminate and a polymer electrolyte fuel cell obtained by using the catalyst.

  In order to solve the above-mentioned problems, the inventors of the present invention have made extensive studies and, as a result, in a catalyst transfer film for a polymer electrolyte fuel cell in which a catalyst layer is formed on a film substrate, It has been found that a desired catalyst transfer film that solves the above problems can be obtained by forming a specific through-hole on the surface that is not in contact. The present invention has been completed based on such findings.

  That is, the present invention relates to the following catalyst transfer film, catalyst layer-electrolyte membrane laminate, and polymer electrolyte fuel cell.

Item 1. (1) A catalyst layer is provided on the film substrate,
(2) Two or more through holes are provided on the surface of the film base that is not in contact with the catalyst layer,
(3) The through hole has a diameter of 1 to 100 μm,
(4) The shortest distance between the through holes is 1 cm or less.
Catalyst transfer film for polymer electrolyte fuel cells.

  Item 2. Item 2. The catalyst transfer film according to Item 1, wherein the depth of the through hole is not less than the thickness of the film substrate and not more than the total thickness of the catalyst transfer film.

  Item 3. Item 3. A catalyst layer-electrolyte membrane laminate, wherein the catalyst transfer film according to Item 1 or 2 is used, and a catalyst layer is provided on one side or both sides of the electrolyte membrane.

  Item 4. Item 6. A polymer electrolyte fuel cell comprising the catalyst layer-electrolyte membrane laminate according to Item 3.

1. Catalyst transfer film The catalyst transfer film for a polymer electrolyte fuel cell of the present invention,
(1) A catalyst layer is provided on the film substrate,
(2) Two or more through holes are provided on the surface of the film base that is not in contact with the catalyst layer,
(3) The through hole has a diameter of 1 to 100 μm,
(4) The shortest distance between the through holes is 1 cm or less.
Is.

  Hereinafter, each component will be described.

<Film base>
The film substrate is not particularly limited, and known or commercially available materials can be used. For example, polymer films such as polyethylene resin, polypropylene resin, polyester resin, polyethylene terephthalate resin, polystyrene resin, cyclic polyolefin resin, polyacrylic resin, and polyimide resin can be used.

  In order to improve transferability, a release treatment may be performed on these polymer films. Examples of the release treatment include those performed by forming a release layer on the laminated film or by performing an unevenness treatment on the laminated film. The release layer is formed using a material having excellent release properties. As an example of a preferable release layer, the release layer can be obtained by adding a material having excellent release properties such as silicone oil, silicone wax, silicone resin, and fluorine resin to a thermoplastic resin or a thermosetting resin. What is formed from a mixture is mentioned. A thin film made of an inorganic oxide such as silicon oxide may be formed by a vapor deposition method such as chemical vapor deposition (CVD) or physical vapor deposition.

  In addition to the polymer film, paper such as art paper, coated paper, coated paper such as lightweight coated paper, and non-coated paper such as notebook paper and copy paper may be used. In addition, carbon fiber sheets such as carbon cloth and carbon paper may be used. Among these, inexpensive and easily available polymer films are preferable, and polyethylene terephthalate resin and the like are particularly preferable.

  Although the thickness of a film base material is not limited, For example, from a viewpoint of a handleability and economical efficiency, about 2.5 micrometers-200 micrometers, Preferably it is about 10 micrometers-150 micrometers, Furthermore, what is necessary is just to be about 10 micrometers-100 micrometers. The size of the film substrate is not limited, but may be about 10 to 200 mm × 10 to 200 mm, which is a generally used size.

<Catalyst layer>
The catalyst layer is not particularly limited as long as it can be used as a catalyst layer of a polymer electrolyte fuel cell. In general, (1) catalyst-carrying carbon particles (carbon particles carrying a catalyst) and (2) hydrogen ion conduction Essential polymer electrolyte.

  Known or commercially available catalyst-supporting carbon particles and hydrogen ion conductive polymer electrolytes can be used.

  Any catalyst may be used as long as it causes a cell reaction of the fuel cell. Examples of the catalyst include platinum, a platinum alloy, and a platinum compound. Specific 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.

  Examples of the hydrogen ion conductive polymer electrolyte include a perfluorosulfonic acid-based fluorine ion exchange resin, in particular, a perfluorocarbon sulfonic acid polymer (PFS-based) in which the C—H bond of a hydrocarbon ion-exchange membrane is substituted with fluorine. Polymer) and the like. Specific examples of such an electrolyte include “Nafion” (registered trademark) manufactured by DuPont, “Flemion” (registered trademark) manufactured by Asahi Glass Co., Ltd., “Aciplex” (registered trademark) manufactured by Asahi Kasei Corporation, Examples include “Gore Select” (registered trademark) manufactured by Gore.

  The thickness of the catalyst layer is not limited and may be in a range generally adopted as a catalyst layer of a polymer electrolyte fuel cell. For example, the thickness may be about 10 to 50 μm, preferably about 15 to 30 μm. The size of the catalyst layer is not limited, but may be about 10 to 200 mm × 10 to 200 mm which is the same size as the film substrate.

  The content ratio of the catalyst-supporting carbon particles and the hydrogen ion conductive polymer electrolyte is about 0.1 to 5 parts by weight, preferably about 0.2 to 4 parts by weight with respect to 1 part by weight of the former. Good.

  The catalyst layer may contain known additives such as carbon fibers, for example, vapor grown carbon fibers (VGCF), carbon nanotubes, and carbon wires, as necessary.

<Through hole>
In the catalyst transfer film for a polymer electrolyte fuel cell of the present invention, two or more through holes are provided on the surface of the film base that is not in contact with the catalyst layer.

  This through hole means a hole penetrating the film substrate, and this through hole may be provided only in the film substrate, may reach the catalyst layer, It may penetrate the catalyst layer.

  The method for forming the through-holes on the surface of the base film of the catalyst transfer film is not particularly limited. For example, a needle punch method in which a heated needle is pressed; an embossing roll, an abrasive roll, a grindstone, an abrasive tape, etc. Hot melt drilling method to melt and punch material film; Physical drilling method using knife, cutter, needle, saw blade, sewing blade, etc .; Laser, beam processing, corona discharge, plasma discharge processing method, etc. It can be performed by a method or the like.

  The shape of the through hole may be a perforated line shape, a round hole shape, a square shape, a crescent shape, or any other shape.

<Catalyst transfer film>
The catalyst transfer film of the present invention is
Method 1: A method of forming a catalyst layer by applying and drying a composition for forming a catalyst layer on a film substrate, and then forming two or more through holes from the film substrate side,
Method 2: Any of the methods of forming a catalyst layer by forming two or more through-holes on the surface of a film substrate and then applying and drying the catalyst layer forming composition on the film substrate. be able to.

In Method 1 In Method 1, a catalyst layer is formed by applying and drying a catalyst layer forming composition on a film substrate, and then two or more through holes are formed from the film substrate side.

  A catalyst layer is obtained by apply | coating and drying the composition for catalyst layer formation on a film base material.

  The composition for forming a catalyst layer is a composition for forming the catalyst layer, and a solvent is essential in addition to the catalyst-supporting carbon particles and the hydrogen ion conductive polymer electrolyte.

  As the solvent, known or commercially available solvents can be used, and examples thereof include various alcohols, various ethers, various dialkyl sulfoxides, water, and mixtures thereof. Examples of the alcohol include monohydric alcohols having 1 to 4 carbon atoms such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, s-butanol, and t-butanol, propylene glycol, ethylene glycol, diethylene glycol, Examples include polyhydric alcohols such as glycerin. These solvents may be used alone or in a combination of two or more.

  In the catalyst layer forming composition, the catalyst-supporting carbon particles and the hydrogen ion conductive polymer electrolyte are blended in a predetermined ratio. For example, 0.1 to 5 parts by weight (particularly 0.2 to 4 parts by weight) of a hydrogen ion conductive polymer electrolyte (solid content) and 5 to 50 parts by weight of a solvent with respect to 1 part by weight of catalyst-supporting carbon particles. (Especially 10 to 30 parts by weight) should be contained, with the remainder being water. The ratio of water is usually equal to 20 times the weight of the catalyst-supporting carbon particles.

  The method for applying the composition for forming a catalyst layer is not particularly limited. For example, knife coater, bar coater, blade coater, spray, dip coater, spin coater, roll coater, die coater, curtain coater, screen printing. A general method such as can be applied.

  After applying the composition for forming a catalyst layer, the catalyst layer is formed by drying. A drying temperature is 40-100 degreeC normally in an atmospheric condition, for example, Preferably it is 60-80 degreeC. The drying time depends on the drying temperature, but is usually about 3 minutes to 2 hours, preferably 30 to 60 minutes.

  Next, two or more through holes are formed from the film substrate side. The method and shape for forming the through hole are as described above.

  The diameter of the through hole in this case is 1 to 100 μm, preferably 1 to 30 μm. When the hole diameter is less than 1 μm, bubbles or the like are difficult to escape when the catalyst layer-electrolyte membrane laminate is produced, and when the hole diameter exceeds 100 μm, the hole has a larger area than the crack of the catalyst layer. In some cases, the catalyst layer may be peeled off, and the long-term battery performance may be deteriorated.

  The shortest distance between the holes is 1 cm or less, preferably 2 mm or less. This is because bubbles or the like generated when the catalyst layer-electrolyte membrane laminate is produced usually have a size of about 1 cm × 1 cm.

  The through hole may penetrate the film substrate, or may penetrate the film substrate and the catalyst layer. That is, the depth of the through hole is not less than the thickness of the film substrate and not more than the total thickness of the catalyst transfer film. Specifically, although depending on the thickness of the film substrate or the catalyst layer, the depth of the through hole is about 2.5 μm to 200 μm, preferably about 10 μm to 150 μm, which is the same as the thickness of the film substrate. May be about 10 μm to 100 μm. This is because if it is too small, it will not penetrate the film base material, so that air will not escape, and if it is too large, the catalyst layer will tend to peel off.

In the case of Method 2, in Method 2, two or more through holes are formed on the surface of the film substrate, and then the catalyst layer forming composition is applied and dried on the film substrate to form a catalyst layer. The method and shape for forming the through hole are as described above.

  In this case, the diameter of the through hole is 1 to 100 μm, preferably 1 to 60 μm. If the diameter of the through hole is less than 1 μm, bubbles or the like are difficult to escape when the catalyst layer-electrolyte membrane laminate is produced, and if the diameter of the through hole exceeds 100 μm, the ink is lined.

  The shortest distance between the through holes is 1 cm or less, preferably 5 mm or less. This is because bubbles or the like generated when the catalyst layer-electrolyte membrane laminate is produced usually have a size of about 1 cm × 1 cm.

  The through hole penetrates the film base material. Specifically, although depending on the thickness of the film substrate, the depth of the through hole is about 2.5 μm to 200 μm, preferably about 10 μm to 150 μm, more preferably about 10 μm to the thickness of the film substrate. What is necessary is just to be about 100 micrometers. This is because if it is too small, it will not penetrate the film base material, so that air will not escape, and if it is too large, the catalyst layer will tend to peel off.

  Next, a catalyst layer is formed by applying and drying the composition for forming a catalyst layer on a film substrate.

  The surface on which the composition for forming a catalyst layer is applied may be either surface of the film substrate because the holes formed in the film substrate are through holes. The composition of the catalyst layer forming composition, the coating method, the drying temperature, and the like may be the same as in Method 1.

2. Catalyst layer-electrolyte membrane laminate The catalyst layer-electrolyte membrane laminate of the present invention for a polymer electrolyte fuel cell is provided with a catalyst layer on one or both sides of the solid polymer electrolyte membrane using the catalyst transfer film of the present invention. It is made.

<Electrolyte membrane>
The electrolyte membrane is not limited as long as it is hydrogen ion conductive, and a known or commercially available membrane can be used. Specific examples of the electrolyte membrane include, for example, “Nafion” membrane manufactured by DuPont, “Flemion” membrane manufactured by Asahi Glass Co., Ltd., “Aciplex” membrane manufactured by Asahi Kasei Co., Ltd., and “Gore” manufactured by Gore. For example, “Select” film.

  The thickness of the electrolyte membrane is usually about 1 to 250 μm, preferably about 5 to 80 μm.

<Method for forming catalyst layer>
The catalyst layer-electrolyte membrane laminate of the present invention is obtained by transferring the catalyst transfer film of the present invention to one or both surfaces of the electrolyte membrane.

  The transfer method may be performed according to a conventional method, for example, by placing the polymer electrolyte membrane and the catalyst layer of the catalyst transfer film so as to face each other and applying pressure.

The extent of pressurization, in order to avoid transfer failure, usually 5~100kgf / cm ² or so, preferably from about 10~70kgf / cm ^2. Further, during the pressurizing operation, it is preferable to pressurize the pressurizing surface in order to further prevent transfer defects. The pressurization temperature is preferably about 200 ° C. or less, particularly about 100 to 150 ° C. from the viewpoint of avoiding breakage, deformation and the like of the electrolyte membrane.

3. Electrolyte Membrane-Electrode Assembly The electrolyte membrane-electrode assembly for use in the present invention is a catalyst layer-electrolyte membrane laminate of the present invention, the gas diffusion base material is a catalyst layer on one side or both sides. And the gas diffusion base material are in contact with each other.

  The gas diffusion base material is not limited, and examples thereof include a carbon base material having air permeability. Specifically, a known material such as carbon cloth, carbon paper, carbon felt may be used.

  Further, those carbon substrates that have been subjected to water repellent treatment may be used. The water repellent treatment can be performed, for example, by impregnating a carbon base material with a polytetrafluoroethylene emulsion liquid, followed by drying and baking.

  Furthermore, you may use what performed the process (smooth process) for smooth | blunting the surface of a carbon base material. For example, it can be made smooth by applying and drying an ink mainly composed of carbon black, polytetrafluoroethylene and water on a carbon substrate.

  The thickness of the gas diffusion substrate is usually about 20 to 1000 μm, preferably about 100 to 400 μm.

  The electrolyte membrane-electrode assembly for a polymer electrolyte fuel cell used in the present invention includes, for example, a gas diffusion substrate, a catalyst layer and a gas diffusion group on one or both sides of the electrolyte membrane-catalyst layer assembly of the present invention. It arrange | positions so that a material may face and it can produce by hot-pressing.

The pressure level at the time of hot pressing is usually about 1 to 100 kgf / cm ² , preferably about 5 to 70 kgf / cm ² . Moreover, the heating temperature in this case may be about 120-150 degreeC normally.

4). Solid polymer fuel cell By providing a known or commercially available separator to the electrolyte membrane-electrode assembly, a solid polymer fuel cell of the present invention comprising the catalyst layer-electrolyte membrane laminate of the present invention is obtained. Can do.

  According to the present invention, when the catalyst transfer film is transferred onto the electrolyte membrane by a hot press or the like, bubbles and the like between the catalyst transfer film and the electrolyte membrane are easily removed, thereby causing transfer defects and distortions on the transferred catalyst layer surface. The catalyst transfer film which can suppress and can manufacture a smooth catalyst layer-electrolyte membrane laminated body is obtained. In addition, this eliminates the need for a stretching process, and there is an advantage that mass production can be performed in a short time and an expensive apparatus is not necessary.

  The present invention will be described more specifically with reference to the following examples and comparative examples. In addition, this invention is not limited to the following embodiment. In the following examples, all through holes were observed with an electron microscope (manufactured by JEOL Ltd.).

Example 1
Using a needle in a polyethylene terephthalate film (PET, manufactured by Toray Industries, Inc., thickness 25 μm), a plurality of through holes having a diameter of 50 to 100 μm were formed to prepare a base film. At this time, the shortest distance between the through holes was 1 cm.

  A platinum-supported catalyst (manufactured by Tanaka Kikinzoku Kogyo Co., Ltd.), a Nafion solution (manufactured by DuPont), isopropyl alcohol and water are mixed and stirred to form a catalyst layer forming composition. The catalyst transfer film of Example 1 was obtained by drying at 70 ° C. for 30 minutes (catalyst layer thickness: 20 μm).

  This catalyst transfer film was cut into 50 mm × 50 mm, and hot-pressed on an electrolyte membrane (manufactured by DuPont, Nafion) to produce a catalyst layer-electrolyte membrane laminate of Example 1.

Example 2
Using an excimer laser (manufactured by GS Yuasa Corporation) on a polyethylene terephthalate film (PET, manufactured by Toray Industries, Inc., thickness 25 μm), a plurality of through-holes having a diameter of 1 μm are formed, and a base film is formed. Produced. At this time, the shortest distance between the through holes was set to 0.1 mm.

  The catalyst layer forming composition used in Example 1 was applied to this film and dried at 70 ° C. for 30 minutes to obtain a catalyst transfer film of Example 2 (catalyst layer thickness: 20 μm).

  This catalyst transfer film was cut into 50 mm × 50 mm, and hot-pressed on an electrolyte membrane (manufactured by DuPont, Nafion) to produce a catalyst layer-electrolyte membrane laminate of Example 2.

Example 3
A diamond powder having a particle size distribution of particle size # 60 to 120 was applied to an outer peripheral surface of a metal roll using an epoxy resin as a binder, dried and cured to prepare a grindstone roll.

  A polyethylene terephthalate film (PET, manufactured by Toray Industries, Inc., thickness 25 μm) was passed between the grindstone roll and the receiving roll, and the grindstone roll was pressed and roughened. Thereby, the rough surface which has many through-holes of the magnitude | size of 5-50 micrometers in the whole surface of the film was formed. At this time, the shortest distance between the through holes was 0.1 cm.

  The catalyst layer forming composition used in Example 1 was applied to this film and dried at 70 ° C. for 30 minutes to obtain a catalyst transfer film of Example 3 (catalyst layer thickness: 20 μm).

  This catalyst transfer film was cut into 50 mm × 50 mm, and hot-pressed on an electrolyte membrane (manufactured by DuPont, Nafion) to produce a catalyst layer-electrolyte membrane laminate of Example 3.

Example 4
The composition for forming a catalyst layer used in Example 1 was applied to a polyethylene terephthalate film (PET, manufactured by Toray Industries, Inc., thickness 25 μm) and dried at 70 ° C. for 30 minutes (catalyst layer thickness: 20 μm). .

  A plurality of through-holes (depth: 25 μm to 45 μm) having a diameter of 50 to 100 μm were formed on the catalyst transfer film using a needle to obtain a catalyst transfer film of Example 4. At this time, the shortest distance between the through holes was 1 cm.

  This catalyst transfer film was cut into 50 mm × 50 mm, and hot-pressed on an electrolyte membrane (manufactured by DuPont, Nafion) to produce a catalyst layer-electrolyte membrane laminate of Example 4.

Example 5
The composition for forming a catalyst layer used in Example 1 was applied to a polyethylene terephthalate film (PET, manufactured by Toray Industries, Inc., thickness 25 μm) and dried at 70 ° C. for 30 minutes (catalyst layer thickness: 20 μm). .

  Using this excimer laser (manufactured by GS Yuasa Corporation), a plurality of through-holes having a diameter of 1 μm (depth: 25 μm to 45 μm) are formed on this catalyst transfer film. Got. At this time, the shortest distance between the through holes was set to 0.1 mm.

  This catalyst transfer film was cut into 50 mm × 50 mm, and hot-pressed on an electrolyte membrane (manufactured by DuPont, Nafion) to produce a catalyst layer-electrolyte membrane laminate of Example 5.

Example 6
The composition for forming a catalyst layer used in Example 1 was applied to a polyethylene terephthalate film (PET, manufactured by Toray Industries, Inc., thickness 25 μm) and dried at 70 ° C. for 30 minutes (catalyst layer thickness: 20 μm). .

  A diamond powder having a particle size distribution of particle size # 60 to 120 was applied to an outer peripheral surface of a metal roll using an epoxy resin as a binder, dried and cured to prepare a grindstone roll.

  Through this catalyst transfer film, a polyethylene terephthalate film (PET, manufactured by Toray Industries, Inc., thickness 25 μm) is passed between the grindstone roll and the receiving roll used in Example 3, and the grindstone roll is pressed to roughen the surface. gave. Thereby, the rough surface which has many through-holes (depth: 25 micrometers-45 micrometers) of a size of 5-50 micrometers on the whole surface of the film was formed, and the catalyst transfer film of Example 6 was obtained. At this time, the shortest distance between the through holes was 0.2 cm.

  This catalyst transfer film was cut into 50 mm × 50 mm, and hot-pressed on an electrolyte membrane (manufactured by DuPont, Nafion) to produce a catalyst layer-electrolyte membrane laminate of Example 6.

Comparative Example 1
A polyethylene terephthalate film (PET, manufactured by Toray Industries, Inc., thickness 25 μm) was not provided with pores, and the catalyst layer forming composition used in Example 1 was applied and dried at 70 ° C. for 30 minutes. 1 catalyst transfer film was obtained (catalyst layer thickness: 20 μm).

  This catalyst transfer film was cut into 50 mm × 50 mm, and hot-pressed on an electrolyte membrane (manufactured by DuPont, Nafion) to produce a catalyst layer-electrolyte membrane laminate of Comparative Example 1.

Comparative Example 2
Using a needle in a polyethylene terephthalate film (PET, manufactured by Toray Industries, Inc., thickness 25 μm), a plurality of through-holes having a diameter of 150 to 200 μm were formed to prepare a base film. At this time, the shortest distance between the through holes was set to 2 mm.

  The catalyst layer forming composition used in Example 1 was applied to this film and dried at 70 ° C. for 30 minutes to obtain a catalyst transfer film of Comparative Example 2 (catalyst layer thickness: 20 μm).

  This catalyst transfer film was cut into 50 mm × 50 mm, and hot-pressed on an electrolyte membrane (manufactured by DuPont, Nafion) to produce a catalyst layer-electrolyte membrane laminate of Comparative Example 2.

Comparative Example 3
Using a needle in a polyethylene terephthalate film (PET, manufactured by Toray Industries, Inc., thickness 25 μm), a plurality of through holes having a diameter of 50 to 100 μm were formed to prepare a base film. At this time, the shortest distance between the through holes was 3 cm.

  The catalyst layer forming composition used in Example 1 was applied to this film and dried at 70 ° C. for 30 minutes to obtain a catalyst transfer film of Comparative Example 3 (catalyst layer thickness: 20 μm).

  This catalyst transfer film was cut into 50 mm × 50 mm, and hot-pressed on an electrolyte membrane (manufactured by DuPont, Nafion) to produce a catalyst layer-electrolyte membrane laminate of Comparative Example 3.

Comparative Example 4
The composition for forming a catalyst layer used in Example 1 was applied to a polyethylene terephthalate film (PET, manufactured by Toray Industries, Inc., thickness 25 μm) and dried at 95 ° C. for 10 minutes (catalyst layer thickness: 20 μm). .

  A plurality of through-holes (depth: 25 μm to 45 μm) having a diameter of 200 μm were formed on the catalyst transfer film using a needle to obtain a catalyst transfer film of Comparative Example 4. At this time, the shortest distance between the through holes was set to 2 mm.

  This catalyst transfer film was cut into 50 mm × 50 mm, and hot-pressed on an electrolyte membrane (manufactured by DuPont, Nafion) to produce a catalyst layer-electrolyte membrane laminate of Comparative Example 4.

  It shows in Table 1 about the hole formed in the film of Examples 1-6 and Comparative Examples 1-4.

Test Example 1: Foaming test The catalyst layer-electrolyte membrane laminates of Examples 1 to 6 and Comparative Examples 1 to 4 were prepared 5 times to evaluate whether or not foaming occurred. In addition, the foaming rate was described as 100% for those that bite bubbles 5 times (in which bubbles were mixed) and 0% for those that did not bite once.

  The results are shown in Table 2.

  In addition, about Examples 1-6 and Comparative Examples 1-4, when the same test was done by making the magnitude | size of a catalyst transfer film into 100 mm x 100 mm, the foaming rate and the foam size did not change. Therefore, according to the present invention, foaming can be suppressed regardless of the size of the catalyst transfer film.

Claims (4)

(1) A catalyst layer is provided on the film substrate,
(2) Two or more through holes are provided on the surface of the film base that is not in contact with the catalyst layer,
(3) The through hole has a diameter of 1 to 100 μm,
(4) The shortest distance between the through holes is 1 cm or less.
Catalyst transfer film for polymer electrolyte fuel cells. The catalyst transfer film according to claim 1, wherein the depth of the through hole is not less than the thickness of the film substrate and not more than the total thickness of the catalyst transfer film. A catalyst layer-electrolyte membrane laminate, wherein the catalyst transfer film according to claim 1 or 2 is used, and a catalyst layer is provided on one side or both sides of the electrolyte membrane. A polymer electrolyte fuel cell comprising the catalyst layer-electrolyte membrane laminate according to claim 3.