JP6746994B2 - Method for manufacturing membrane electrode assembly of fuel cell - Google Patents

Description

The present invention relates to a method for manufacturing a membrane electrode assembly (MEA: Membrane-Electrode Assembly) of a fuel cell.

As a conventional method for producing a membrane electrode assembly, a transfer substrate provided with a catalyst layer having a desired shape and a solid polymer electrolyte membrane are thermocompression-bonded with a hot press, a thermal laminating roll, or the like, and then the substrate is peeled off. The method to do is proposed.
For example, Patent Document 1 discloses a method using a hot press and a method using a thermal laminating roll. The method using the thermal laminating roll is such that a long solid polymer electrolyte membrane and a transfer substrate provided with a catalyst layer having a desired shape arranged on both sides thereof are brought into contact with each other and heat is applied by a pair of thermal laminating rolls. The solid polymer electrolyte membrane and the catalyst layer are integrally bonded by pressure bonding, and then only the base material is peeled from the transfer base material using a pair of peeling rolls, and the catalyst layer is solid polymer electrolyte. Transferred to the film surface.

On the other hand, in Patent Document 2, after the thermal transfer, a gasket member is provided in order to prevent gas leakage to the exposed portion of the surface of the solid polymer electrolyte membrane and intensive deterioration of a region of the electrolyte where the catalyst layer is not formed. A technique for obtaining a membrane electrode assembly is disclosed.
Here, in the method of applying the gasket member of Patent Document 2, since the outer periphery of the catalyst layer already formed is covered, in order to completely eliminate the exposed portion between the catalyst layer and the solid polymer electrolyte membrane, There is no option other than mounting a gasket member on the catalyst layer. Since the riding portion does not participate in the power generation of the fuel cell, there is a concern that the utilization efficiency of the catalyst layer will decrease.

In addition to the thermal transfer method, there is a method as described in Patent Document 3 in which a catalyst ink is directly applied to a solid polymer electrolyte membrane and dried to form a catalyst layer. This method does not require a transfer substrate and a transfer process, and thus can reduce costs and simplify the process. However, even in this method, as in Patent Document 2, since the gasket member is provided after the catalyst layer is formed, the utilization efficiency of the catalyst layer is lowered.

Further, as in Patent Document 4, after a mask material having an opening hollowed into an electrode shape in advance is attached to the solid polymer electrolyte membrane, the catalyst ink is formed in the same manner as in Patent Document 3 to form a catalyst layer. There is also a method. However, in this method, since the openings are opened on the front and back surfaces of the solid polymer electrolyte membrane before coating, the solid polymer electrolyte membrane portion moves flexibly. The dimensional change occurs in the solid polymer electrolyte membrane due to the permeation of the contained solvent. Since the dimensional change of the solid polymer electrolyte membrane portion having the dimensional change and the dimensional change of the electrolyte membrane portion in the non-opening portion are largely different, the planarity of the obtained MEA is deteriorated. MEA having poor planarity has a problem that it is difficult to incorporate it in a power generation cell.

JP, 10-64574, A Japanese Patent No. 5720810 JP, 2015-162308, A Japanese Patent No. 4737924

The present invention has been made in view of the above points, and does not reduce the utilization efficiency of the catalyst layer due to the riding of the gasket material, and suppresses the reduction in the planarity of the membrane electrode assembly while using a simple process. An object of the present invention is to provide a method for producing a membrane electrode assembly that can be manufactured.

One aspect of a method for producing a membrane electrode assembly for solving the above problem is a laminating step of laminating a laminated film on each of the front surface and the back surface of a solid polymer electrolyte membrane so that a cross section of at least one side is exposed. When,
A step of removing the catalyst layer forming portion of the laminated film to expose the front and back surfaces of the solid polymer electrolyte membrane,
While heating on the heating unit, a catalyst ink, a coating step of applying to the front and back surfaces of the exposed solid polymer electrolyte membrane,
A drying step of drying the catalyst ink to form a catalyst layer,
The drying time in the drying step is 30 seconds or less.

Here, in the above-mentioned method for producing a membrane electrode assembly, the volatile component of the catalyst ink in the coating step is water and a solvent having a higher volatility than water, and the mass ratio of water to the solvent is 6:4 to 4. : 6 is preferred.
Further, in the above-mentioned method for producing a membrane electrode assembly, it is preferable that the heating temperature by the heating unit in the coating step is 70° C. or higher and lower than 120° C.
In the method for producing a membrane electrode assembly, it is preferable that the coating step and the drying step are sequentially performed on the front surface and the back surface of the solid polymer electrolyte membrane.
Further, in the above-mentioned method for producing a membrane electrode assembly, it is preferable that the coating step and the drying step are performed simultaneously on the front surface and the back surface of the solid polymer electrolyte membrane.

According to one aspect of the present invention, it is possible to suppress a decrease in flatness due to the influence of a dimensional change of the solid polymer electrolyte membrane.

It is a schematic diagram showing one embodiment of a manufacturing method of a membrane electrode assembly.

Hereinafter, an embodiment of a method for manufacturing a membrane electrode assembly will be described with reference to the drawings. The present invention is not limited to the embodiments described below, and modifications such as design changes can be added based on the knowledge of those skilled in the art, and embodiments with such modifications added Also included in the scope of the embodiments of the present invention.
The method for manufacturing a membrane electrode assembly of the present embodiment includes a bonding step, a catalyst layer forming portion removing step, a coating step, and a drying step.

The laminating step is a step of laminating the laminated film on each of the front surface and the back surface of the solid polymer electrolyte membrane so that the cross section of at least one side is exposed.
The catalyst layer forming portion removing step is a step of removing the catalyst layer forming portion of the laminated film to expose the front and back surfaces of the solid polymer electrolyte membrane.
The applying step is a step of applying the catalyst ink to the exposed front and back surfaces of the solid polymer electrolyte membrane while heating on the heating unit. The volatile component of the catalyst ink is water and a solvent having higher volatility than water, and the mass ratio of water to the solvent is preferably 6:4 to 4:6. The heating temperature by the heating unit is preferably 70° C. or higher and lower than 120° C.
The drying step is a step of drying the catalyst ink to form a catalyst layer, and the drying time in this drying step is 30 seconds or less.

<Laminating process>
First, as shown in FIG. 1A, in a bonding step, an electrolyte membrane substrate 12 is produced by bonding a pair of laminated films 5 and 5 on the front and back surfaces of a solid polymer electrolyte membrane 10.
Here, the laminated film 5 is formed by laminating the gas barrier film 1 having an adhesive layer and the plastic film 4 having an adhesive layer. The laminated film 5 is attached to the front surface and the back surface of the solid polymer electrolyte membrane 10 via the adhesive layer of the gas barrier film 1.
The electrolyte membrane substrate 12 has a configuration in which at least one side of the cross section of the solid polymer electrolyte membrane 10 is exposed without being completely covered by the laminated films 5 and 5. Further, the laminated film 5 has the catalyst layer forming portion 2 having a shape that matches the shape of the catalyst layer described later.
Next, as shown in FIG. 1B, the electrolyte membrane substrate 12 is loaded on the heating unit 20 in a state where it is held smooth.

<Catalyst layer forming part removing step>
Next, as a catalyst layer forming portion removing step, as shown in FIG. 1C, the catalyst layer forming portion 2 of the laminated film 5 on the upper surface of the electrolyte membrane substrate 12 is removed to remove one of the solid polymer electrolyte membranes 10. Expose the part.
<Coating process>
Next, as a coating step, as shown in FIG. 1D, the liquid catalyst ink 3 is coated on the electrolyte membrane substrate 12 by a coating device.

<Drying process>
Next, as a drying step, the volatile components of the catalyst ink 3 are removed by the heat of the heating unit 20. After that, as shown in FIG. 1E, the plastic film 4 is peeled off together with the adhesive layer to obtain the catalyst layer 50 having a desired shape.
After that, the electrolyte membrane substrate 12 is turned upside down and loaded on the heating unit 20 in a state of being held smooth.
Next, as shown in FIG. 1( f ), after removing the catalyst layer forming portion 2 of the laminated film 5 on the upper surface of the electrolyte membrane substrate 12 again, as shown in FIG. Then, the liquid catalyst ink 3 is applied onto the electrolyte membrane substrate 12, and the volatile components are removed by the heat of the heating unit 20.
Next, as shown in FIG. 1(h), the catalyst film 50 having a desired shape is obtained by peeling off the plastic film 4 in the same manner as the already processed opposite surface.

Through the above steps, as shown in FIG. 1I, the membrane electrode assembly 18 having the catalyst layers 50, 50 on both surfaces is obtained.
The above steps are examples in which the coating step and the drying step are sequentially performed on the front surface and the back surface of the solid polymer electrolyte membrane, but the coating step and the drying step are performed on the front surface and the back surface of the solid polymer electrolyte membrane. You may go at the same time.
Here, the solid polymer electrolyte membrane 10 is a polymer material that exhibits good proton conductivity in a wet state. The catalyst ink 3 is formed of powder carbon and a resin carrying a catalyst made of platinum or an alloy of platinum and another metal, and is dried and solidified to form the catalyst layer 50.

Specific examples of materials constituting the solid polymer electrolyte membrane 10, the catalyst layer 50, the gas barrier film 1 having an adhesive layer and the plastic film 4 having an adhesive layer will be given below, but the present invention is not limited thereto.
As the polymer material forming the solid polymer electrolyte membrane 10, specifically, a hydrocarbon-based polymer electrolyte or a fluorine-based polymer electrolyte can be used. As the hydrocarbon-based polymer electrolyte membrane, electrolyte membranes such as sulfonated polyetherketone, sulfonated polyethersulfone, sulfonated polyetherethersulfone, sulfonated polysulfide, and sulfonated polyphenylene can be used. As the fluorine-based polymer electrolyte, for example, Nafion (registered trademark) manufactured by DuPont, Flemion (registered trademark) manufactured by Asahi Glass, Aciplex (registered trademark) manufactured by Asahi Kasei, and Gore Select (registered trademark) manufactured by Gore can be used. Hydrocarbon-based electrolyte membranes have less penetration and swelling by a solvent than fluorine-based polymer electrolytes, and are therefore more preferable to apply the catalyst ink to the solid electrolyte membrane. The thickness of the solid polymer electrolyte membrane 10 is about 5 μm or more and 100 μm or less.

As the resin forming the catalyst layer 50, the same resin as the above polymer material can be used.
Examples of the catalyst that constitutes the catalyst layer 50 include platinum, palladium, ruthenium, iridium, rhodium, and osmium platinum group elements, as well as iron, lead, copper, chromium, cobalt, nickel, manganese, vanadium, molybdenum, gallium, A metal such as aluminum or platinum and an alloy thereof, or an oxide or a double oxide thereof can be used. Among them, platinum and platinum alloys are more preferable. Further, the particle size of the catalyst is preferably 0.5 nm or more and 20 nm or less, because if it is too large, the activity of the catalyst decreases, and if it is too small, the stability of the catalyst decreases.

In addition, the powdered carbon forming the catalyst layer 50 is not particularly limited as long as it is in the form of fine particles, has conductivity, and does not attack the catalyst. Specifically, carbon black, graphite, graphite, activated carbon, carbon fiber, carbon nanotube, fullerene, or the like can be used. The particle size of the powder carbon is preferably 10 nm or more and 100 nm or less, which is smaller than that of the catalyst.
The catalyst layer 50 can be obtained by coating the catalyst ink 3 prepared by dispersing the above materials in a solvent and water on the solid polymer electrolyte membrane 10 and drying. The solvent is lower than water because it is suitable for dispersing the above-mentioned materials, and because a solvent having a lower boiling point than water can be dried before it penetrates the solid polymer electrolyte membrane 10 and swells. It is more preferable to use lower alcohols such as ethanol, 1-propanol, and 2-propanol having a boiling point.

Furthermore, the surface of the catalyst ink 3 is preferably dried on the heating unit 20 at a speed of 30 seconds or less. An ink that requires drying for more than 30 seconds is not preferable because the contained alcohol permeates the solid polymer electrolyte membrane 10 and the electrolyte membrane swells.
The substrate layers of the gas barrier film 1 and the plastic film 4 are not particularly limited as long as they have a glass transition temperature equal to or higher than the heating temperature in the heating section 20, and examples thereof include polyethylene naphthalate, polyethylene terephthalate, polyimide, polyparban. Polymeric films of acid aramid, polyamide (nylon), polysulfone, polyether sulfone, polyether sulfone, polyphenylene sulfide, polyether ether ketone, polyether imide, polyacrylate and the like can be used. Further, a heat resistant fluororesin such as ethylene tetrafluoroethylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroperfluoroalkyl vinyl ether copolymer, polytetrafluoroethylene or the like can be used.

In the substrate of the gas barrier film 1, since it is a membrane electrode assembly as a gasket, polyethylene naphthalate is particularly preferable in view of both gas barrier properties and heat resistance. Polyethylene terephthalate is particularly preferable in consideration of the fact that the base material of the plastic film 4 is not attacked by the catalyst ink and is peeled off.
The pressure-sensitive adhesive layer of the gas barrier film 1 and the plastic film 4 may be an acrylic, urethane-based, silicone-based, or rubber-based pressure-sensitive adhesive, and the adhesion to the base material layer and the solid polymer electrolyte membrane 10 and heating Considering the heat resistance of the part 20, the acrylic type is more preferable.

In order to suppress the overlap and gap between the laminated film 5 and the catalyst layer forming portion 2 to be removed before coating, a cut is made in the laminated film 5 and the catalyst layer forming portion 2 is provided to the laminated film 5, and then the solid height is increased. It is preferable to obtain the electrolyte membrane base material 12 by laminating it with the molecular electrolyte membrane 10. As a result, the solid polymer electrolyte membrane 10 does not come into direct contact with air until immediately before the application of the catalyst ink 3, so that it is possible to suppress the dimensional change due to moisture absorption, and to use the thin solid polymer electrolyte membrane 10 when using the thin solid polymer electrolyte membrane 10. Can also ensure rigidity.

Further, since the laminated films 5 and 5 are present on the front and back surfaces of the solid polymer electrolyte membrane 10 even when the catalyst ink 3 is applied, it is possible to suppress the dimensional change of the solid polymer electrolyte membrane portion which is in contact with the catalyst ink 3. You can Further, since there is no overlap or gap in the catalyst layer forming portion 2 provided by the above method, even when the electrolyte membrane base material 12 is wound in a roll shape, the solid polymer electrolyte membrane 10 does not have a winding mark. Therefore, it is possible to manufacture with a roll-to-roll suitable for mass-producing with the same quality.

In the cross section of the electrolyte membrane substrate 12 obtained by sticking the laminated film 5 and the solid polymer electrolyte membrane 10, one side of the solid polymer electrolyte membrane 10 is exposed. By this exposed portion, it becomes possible for moisture to come in and out at the time of heating and drying in the heating portion 20, and cooling, and it is possible to suppress deterioration of the planarity of the obtained membrane electrode assembly 18.
Since the heating temperature in the heating unit 20 is about the boiling point of the solvent contained in the catalyst ink 3, it is preferably 70° C. or higher, and since it contains water and is dried in 30 seconds or less, 100° C. or higher. Is more preferable. Further, if the temperature is 120° C. or higher, the reaction between the solvent and the catalyst may cause ignition, which is not preferable. Therefore, the temperature is preferably lower than 120° C. Further, the heating unit 20 may have a flat plate shape or a roll shape, and it is preferable that the electrolyte membrane base material 12 is made smooth by adsorption or tension.

The coating device for forming the catalyst layer 50 on the electrolyte membrane substrate 12 may be a coater system such as a die coater system or a roll coater system as long as it can coat the catalyst layer with a uniform thickness. In order to obtain the membrane electrode assembly 18, it is necessary to form the catalyst layers 50, 50 on the front and back surfaces of the solid polymer electrolyte membrane 10, but the solid polymer electrolyte membrane 10 may be sequentially formed on each side, but the cost is reduced. It is possible to do both at the same time on both sides.
In the method of manufacturing a membrane electrode assembly, it is preferable that all steps are continuous in consideration of manufacturing efficiency, but all steps may be discontinuous in consideration of the yield of the step of applying the catalyst layer 50.

According to the membrane electrode assembly manufacturing method described above, the dimensional change of the solid polymer electrolyte membrane 10 is suppressed, so that the high quality membrane electrode assembly 18 having excellent planarity can be manufactured. In addition, by sticking a sheet having a discontinuous flat surface on the front and back surfaces of the solid polymer electrolyte membrane 10, even if the solid polymer electrolyte membrane is used in a roll-to-roll system without wrinkles, unnecessary winding traces can be formed. It is possible to provide a method for producing a membrane electrode assembly that can suppress the generation.
The membrane electrode assembly having good flatness obtained in the present embodiment is provided with a separator for supplying a reaction gas to each electrode in a fuel cell and discharging moisture or excess gas generated by an electrochemical reaction. Sometimes there are no gaps. That is, according to this embodiment, it is possible to obtain a membrane electrode assembly in which the power generation performance is not deteriorated.

Hereinafter, examples of the present invention will be specifically described. However, the invention is not limited to only these examples.
(Example 1)
<Production of membrane electrode assembly>
A roll-to-roll type polyethylene naphthalate with a width of 90 mm (Teonex Q51 made by Teijin DuPont Film, thickness 12 μm), an acrylic adhesive layer (thickness 10 μm) was formed, and laminated with a separator to obtain a gas barrier film polyethylene Similarly to the naphthalate surface, a 90 mm wide polyethylene terephthalate-attached plastic film (Promoto Save 25CBFS2 made by Kimoto) having an acrylic adhesive layer is attached via the polyethylene terephthalate adhesive layer. Furthermore, a surface protection film (Sanitec PAC-3-60T manufactured by San-A Kaken) is attached to the polyethylene terephthalate surface, and a notch is made from the polyethylene terephthalate separator side to the polyethylene naphthalate by punching a 5 cm × 5 cm square shape. After that, a laminated film having a catalyst layer forming portion was obtained. Further, by a roll-to-roll method, the separator on the polyethylene terephthalate of this laminated film was peeled off, and the solid polymer electrolyte membrane having a width of 95 mm was aligned and bonded to both sides of the hydrocarbon film (thickness 11 μm), By peeling off the surface protective films on both sides, a roll of the electrolyte membrane substrate was obtained in which the cross section of the solid polymer electrolyte membrane was exposed. The obtained electrolyte membrane base material in roll form is cut out in the width direction, heated as a heating unit on an adsorption stage at 100° C., the catalyst layer forming unit is removed, and the catalyst ink is applied with a die coater for 30 seconds. After drying, a catalyst layer was provided on one side. At this time, the composition of the catalyst ink consists of a fluorine-based polymer electrolyte membrane dispersion solution (SS700C/25 manufactured by Asahi Kasei E-Materials), a platinum catalyst (TEC10F50E-HT manufactured by Tanaka Kikinzoku), water, 1-propanol, and water and a solvent. Ratio (mass ratio) was 6:4, and the solid content concentration in the ink was 8%. This electrolyte membrane substrate is turned upside down on an adsorption stage at 100° C. to remove the catalyst layer forming portion 2 of the laminated film 5 having a discontinuous flat surface, and then the catalyst ink is applied and dried in the same manner. A membrane/electrode assembly having a catalyst layer provided on the substrate was obtained. Table 1 shows the evaluation results of the planarity of the obtained membrane electrode assembly.

(Example 2)
A membrane/electrode assembly of Example 2 was prepared in the same manner as in Example 1 except that the water/solvent ratio of the catalyst ink and the drying completion time were changed as shown in Table 1. Table 1 shows the evaluation results of the planarity of the obtained membrane electrode assembly.
The drying completion time in Table 1 is visually confirmed that the surface of the catalyst ink on the solid polymer electrolyte membrane was sufficiently dried, and the time taken at that time is shown as the drying completion time. ..

(Example 3)
A membrane/electrode assembly of Example 3 was produced in the same manner as in Example 1 except that the drying temperature and the drying completion time were changed as shown in Table 1. Table 1 shows the evaluation results of the planarity of the obtained membrane electrode assembly.
(Example 4)
A membrane/electrode assembly of Example 4 was produced in the same manner as in Example 1 except that only the alcohol species in the catalyst ink was changed. Table 1 shows the evaluation results of the planarity of the obtained membrane electrode assembly.
(Comparative Example 1)
Membrane electrode assembly of Comparative Example 1 in the same manner as in Example 1 except that the width of the solid polymer electrolyte membrane was 80 mm and a roll of the electrolyte membrane base material in which the cross section of the solid polymer electrolyte membrane was not exposed was prepared. Was produced. The results of the same evaluations as in Example 1 are shown in Table 1.

(Comparative example 2)
A membrane/electrode assembly of Comparative Example 2 was produced in the same manner as in Example 1 except that the water/solvent ratio of the catalyst ink and the drying completion time were changed as shown in Table 1. Table 1 shows the evaluation results of the planarity of the obtained membrane electrode assembly.
(Comparative example 3)
A membrane/electrode assembly of Comparative Example 3 was produced in the same manner as in Example 1 except that the drying temperature and the drying completion time were changed as shown in Table 1. Table 1 shows the evaluation results of the planarity of the obtained membrane electrode assembly.
(Comparative example 4)
A membrane/electrode assembly of Comparative Example 4 was produced in the same manner as in Example 1 except that only the alcohol species in the catalyst ink was changed. Table 1 shows the evaluation results of the planarity of the obtained membrane electrode assembly.

<Evaluation>
As shown in Table 1, it was confirmed that the cross-section of the solid polymer electrolyte membrane was exposed when the solid polymer electrolyte membrane and the laminated film were bonded (Example 1), and thus the flatness was not deteriorated. Thereby, only in Example 1, it became easy to incorporate the membrane electrode assembly into the power generation cell of the fuel cell.
Further, with the ratio of water and solvent in Examples 1 and 2, the drying was completed in about 30 seconds after the application and heating of the catalyst ink, so that the permeation into the solid polymer electrolyte membrane was suppressed and the flatness due to swelling was suppressed. The decline is also suppressed. However, in Comparative Example 2, it took 40 seconds until the drying was completed, and it was confirmed that the flatness of the membrane electrode assembly was deteriorated. This decrease in planarity is due to the permeation into the solid polymer electrolyte membrane due to the increased amount of solvent.

Further, at the drying temperature of Examples 1 and 3, the drying was completed in about 30 seconds after the catalyst ink was applied and heated, so that the permeation into the solid polymer electrolyte membrane was suppressed and the reduction in the flatness due to the swelling was also suppressed. Has been. However, in Comparative Example 3, it took 50 seconds to complete the drying, and it was confirmed that the flatness of the obtained membrane electrode assembly was lowered. This decrease in flatness is due to the penetration into the solid polymer electrolyte membrane, which took a long time to complete the drying.
In addition, since the alcohols of Examples 1 and 4 volatilize preferentially over water, the permeation into the solid polymer electrolyte membrane is suppressed during coating and drying, and the reduction in flatness due to swelling is suppressed. .. However, since 1-butanol used in Comparative Example 4 has lower volatility than water, it penetrates into the solid polymer electrolyte membrane during coating and drying, and thus the flatness of the obtained membrane electrode assembly is deteriorated. Was confirmed.

1 Gas Barrier Film 2 Catalyst Layer Forming Part 3 Catalyst Ink 4 Plastic Film 5 Laminated Film 10 Solid Polymer Electrolyte Membrane 12 Electrolyte Membrane Base Material 18 Membrane Electrode Assembly 20 Heating Part 50 Catalyst Layer

Claims (11)

A laminating step of laminating a laminated film having no opening on the front surface and the back surface of the solid polymer electrolyte membrane so that the cross section of at least one side is exposed,
After the bonding step, a catalyst layer forming portion removing step of removing the catalyst layer forming portion of the laminated film to expose the front surface and the back surface of the solid polymer electrolyte membrane,
While heating on the heating unit, a catalyst ink, a coating step of coating the exposed surface and the back surface of the solid polymer electrolyte membrane,
A drying step of drying the catalyst ink to form a catalyst layer,
The method for producing a membrane electrode assembly for a fuel cell, wherein the drying time in the drying step is 30 seconds or less. The fuel cell according to claim 1, wherein the volatile component of the catalyst ink in the coating step is water and a solvent having higher volatility than water, and the mass ratio of water to the solvent is 6:4 to 4:6. Method for manufacturing membrane electrode assembly. The method for producing a membrane electrode assembly for a fuel cell according to claim 1 or 2, wherein a heating temperature by the heating unit in the coating step is 70°C or higher and lower than 120°C. The method for producing a membrane electrode assembly for a fuel cell according to claim 1, wherein the applying step and the drying step are sequentially performed on the front surface and the back surface of the solid polymer electrolyte membrane. The method for producing a membrane electrode assembly for a fuel cell according to claim 1, wherein the applying step and the drying step are performed simultaneously on the front surface and the back surface of the solid polymer electrolyte membrane. The laminated film, in order from the solid polymer electrolyte membrane side, a gas barrier film, and a plastic film,
The method for producing a membrane electrode assembly for a fuel cell according to claim 1, wherein after the drying step, the plastic film is peeled off leaving the gas barrier film on the solid polymer electrolyte membrane side. The laminated film, in order from the solid polymer electrolyte membrane side, a gas barrier film having an adhesive layer, and a plastic film having an adhesive layer,
The gas barrier film and the plastic film are respectively polyethylene naphthalate, polyethylene terephthalate, polyimide, polyparbanic acid aramid, polyamide (nylon), polysulfone, polyether sulfone, polyether sulfone, polyphenylene sulfide, polyether ether ketone, 7. Any one of claims 1 to 6 containing polyetherimide, polyacrylate, ethylene tetrafluoroethylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroperfluoroalkyl vinyl ether copolymer, or polytetrafluoroethylene. 2. The method for producing a membrane electrode assembly for a fuel cell according to item 1. The laminated film, in order from the solid polymer electrolyte membrane side, a gas barrier film having an adhesive layer, and a plastic film having an adhesive layer,
The gas barrier film is composed of polyethylene naphthalate,
The method for producing a membrane electrode assembly for a fuel cell according to claim 1, wherein the plastic film is made of polyethylene terephthalate. The method for producing a membrane electrode assembly for a fuel cell according to claim 7, wherein the adhesive layer contains an acrylic, urethane, silicone, or rubber adhesive. The method for producing a membrane electrode assembly for a fuel cell according to claim 7, wherein the adhesive layer contains an acrylic adhesive. The method for producing a membrane electrode assembly for a fuel cell according to claim 1, wherein the solid polymer electrolyte membrane has a thickness within a range of 5 μm or more and 100 μm or less.

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