JP2017054727A - Manufacturing method of membrane electrode assembly, and membrane electrode assembly - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method capable of suppressing reduction in utilization efficiency of a catalyst, obtaining a membrane electrode assembly in which an exposed portion does not exist between an electrode catalyst layer and a solid polymer electrolyte membrane, and also improving transferability of the electrode catalyst layer as a manufacturing method of a membrane electrode assembly comprising a gasket material.SOLUTION: The manufacturing method uses a transfer film 11 comprising a substrate 2, a gasket layer 1, a transfer base material 10a and an electrode catalyst layer 50a. The gasket layer 1 includes a cutting line 13 which coincides with a contour line of a planar shape of the electrode catalyst layer of a membrane electrode assembly 5 to a boundary position with the substrate 2. The electrode catalyst layer 50a and the transfer base material 10a have a contour surface that coincides with the cutting line of the gasket layer 1. The electrode catalyst layer 50a and the gasket layer 1 are thermally compression-bonded towards mutually opposite surfaces of the polymer electrolyte membrane 4, the transfer base material 10a is then peeled from the electrode catalyst layer 50a, and the frame-shaped gasket layer 1a outside of the cutting line 13 is peeled from the substrate 2.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for producing a membrane-electrode assembly (MEA) constituting a solid polymer fuel cell and a membrane electrode assembly.

  Conventionally, as a method for producing a membrane electrode assembly, an electrode catalyst layer having a desired shape (hereinafter also simply referred to as “catalyst layer”) is bonded to a solid polymer electrolyte membrane by thermocompression bonding or the like, and then gas leakage suppression is performed. There is a method of forming a gasket material on the outer periphery of the catalyst layer so as to cover the solid polymer electrolyte membrane. Since the exposed portion of the solid polymer electrolyte membrane having a large dimensional change is reduced by this gasket material, membrane breakage due to expansion / contraction during power generation can be suppressed.

For example, as shown in Patent Document 1, a solid polymer electrolyte membrane is sandwiched by a transfer sheet for forming a catalyst layer obtained by applying and drying a catalyst paste on a transfer substrate, and hot pressing is performed. Thus, an electrolyte membrane-catalyst layer assembly is obtained. Thereafter, a frame-shaped gasket material is joined so as to cover the outer peripheral edge of the catalyst layer.
In the above-mentioned method, a frame-like gasket material rides on the catalyst layer in order to suppress gas leakage, so that there is a catalyst that does not participate in power generation. Therefore, the utilization efficiency of the expensive catalyst is lowered, and it is difficult to obtain sufficient power generation performance.

Moreover, in patent document 2, after bonding a frame-shaped gasket to a solid polymer electrolyte membrane, the transfer sheet for catalyst layer formation like patent document 1 is hot-pressed, and only a transfer base material is peeled off, A membrane-catalyst layer assembly is obtained.
In the above method, the gasket material is in a frame shape, and the catalyst layer is pushed into the recessed electrolyte membrane portion, so that pressure is strongly applied to the frame-shaped gasket portion. This makes it difficult to transfer the uniform catalyst layer to the electrolyte membrane portion. In addition, the non-uniform transfer creates a gap without a catalyst layer at the frame-shaped portion, and thus an exposed portion of the electrolyte membrane is formed. This exposed portion may be broken by power generation.

  In addition, since the catalyst layer also touches the gasket material during hot pressing, it is necessary to attach a mask material or perform a release treatment with a release agent to prevent the catalyst layer from being transferred to the gasket material. There is concern about performance degradation due to release and release of the release agent during power generation.

JP 2009-135068 A JP 2006-244930 A

  An object of the present invention is to provide a membrane electrode assembly having a gasket material, in which a decrease in catalyst utilization efficiency is suppressed, and there is no exposed portion between the catalyst layer and the solid polymer electrolyte membrane. It is an object of the present invention to provide a method capable of improving the transferability of the obtained catalyst layer.

1st aspect of this invention is a manufacturing method of the membrane electrode assembly which has a polymer electrolyte membrane and the electrode catalyst layer formed by the predetermined planar shape in the surface which becomes the mutually opposite side of the said polymer electrolyte membrane. In this method, the following step (2) is performed using a transfer film satisfying the following constitution (1).
(1) It has a substrate, a gasket layer bonded onto the substrate, a transfer base material bonded onto the gasket layer, and an electrode catalyst layer formed on the transfer base material. The gasket layer has a cut line coinciding with the planar outline line up to a boundary position with the substrate. The electrode catalyst layer and the transfer substrate have an outer surface that matches the score line, and are present on the gasket layer in a shape that matches the planar shape.

(2) After thermocompression bonding the electrode catalyst layer and the gasket layer of the transfer film toward the surface of the polymer electrolyte membrane, the transfer substrate is peeled from the electrode catalyst layer, The planar electrode catalyst layer and the frame-shaped gasket layer are transferred from the transfer film to the surface of the polymer electrolyte membrane by peeling the outer frame-shaped gasket layer from the substrate. To do. Thus, the planar electrode catalyst layer and the frame-shaped gasket layer are formed on the surface of the polymer electrolyte membrane.

  A second aspect of the present invention is a membrane electrode assembly comprising a polymer electrolyte membrane and an electrode catalyst layer formed in a predetermined planar shape on opposite surfaces of the polymer electrolyte membrane, A frame-like gasket layer having an inner surface (inner surface, inner surface) coinciding with the planar outer shape line is formed outside the electrode catalyst layer on the surface of the polymer electrolyte membrane, and the electrode In this membrane electrode assembly, the outer surface (outer surface, outer peripheral surface) of the catalyst layer is in contact with the inner surface of the gasket layer. That is, in the membrane electrode assembly according to the second aspect, the electrode catalyst layer and the gasket layer are in contact with each other on a surface that coincides with the planar outline.

  According to the method for producing a membrane / electrode assembly of the present invention, as a membrane / electrode assembly having a gasket material, a decrease in the utilization efficiency of the catalyst is suppressed, and there is no exposed portion between the catalyst layer and the solid polymer electrolyte membrane. And the transferability of the catalyst layer can be improved.

It is the schematic of the manufacturing method of the membrane electrode assembly corresponded to one Embodiment of this invention. It is the schematic of the manufacturing method of the membrane electrode assembly corresponded to the comparative example of this invention.

The method according to the first aspect can include a step of producing the transfer film by performing the following step (b) using a laminate having the following configuration (a).
(a) a substrate, a gasket layer bonded on the substrate, a transfer substrate bonded on the gasket layer, and an electrode catalyst layer formed on the transfer substrate. The planar shape of the substrate, the gasket layer, the transfer substrate, and the electrode catalyst layer is larger than the planar shape of the electrode catalyst layer formed on the membrane electrode assembly.

(b) From the electrode catalyst layer side of the laminate to the boundary position of the gasket layer with the substrate, cutting was performed with a score line that coincided with the planar outline of the electrode catalyst layer formed on the membrane electrode assembly Then, the transfer substrate outside the cut line is peeled from the gasket layer. Thereby, the said transfer base material and the said electrode catalyst layer outside the said score line are removed from the said laminated body.

The laminate can be produced by a method including a step of bonding the gasket layer to the transfer substrate on which the electrode catalyst layer is formed. Bonding of the substrate and the gasket layer may be performed either before or after the formation of the electrode catalyst layer.
The laminate can be manufactured by a method including a step of forming the electrode catalyst layer on the transfer substrate to which the gasket layer is bonded. Bonding of the substrate and the gasket layer may be performed either before or after the formation of the electrode catalyst layer.

According to the manufacturing method of the membrane electrode assembly of the first aspect and the membrane electrode assembly of the second aspect, since there is no exposed portion of the solid polymer electrolyte membrane, it is possible to suppress the membrane breakage due to gas leak or dimensional change. it can.
Furthermore, when producing the transfer film by performing the step (b) using the laminate having the configuration (a), by performing cutting by stamping or the like, defects after the transfer substrate removal, Since there is no portion where the gasket material is mounted on the catalyst layer and the utilization efficiency of the catalyst is not lowered, high performance can be exhibited.

  According to the manufacturing method of the membrane electrode assembly of the first aspect, the catalyst layer and the gasket material are simultaneously processed into a desired shape in advance, and the shape of the opening of the gasket material and the shape of the catalyst layer are made the same. There is no exposed part between the polymer electrolyte membrane and the catalyst layer, and the use efficiency of the catalyst is not lowered, and the gasket material for suppressing gas leakage is joined. High stability and high performance This membrane electrode assembly can be manufactured. In addition, by processing the shape of the catalyst layer in advance, it is possible to selectively apply pressure to the catalyst layer at the time of heat and pressure, thereby improving transferability.

Next, an embodiment of the present invention will be described. 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. Embodiments to which such modifications are added Are also included in the scope of the present invention.
FIG. 1 is a schematic view for explaining a method for producing a membrane electrode assembly corresponding to an embodiment of the present invention.

  In this method, first, the catalyst ink 3 is applied onto the transfer substrate 10 (a) and then dried to form the electrode catalyst layer 50 (b). A gasket material (gasket layer) 1 having an adhesive layer is bonded to the transfer substrate 10 via the adhesive layer. Further, a plastic film (substrate) 2 having an adhesive layer is bonded to the back surface of the gasket material 1 via the adhesive layer to obtain a gasket substrate 12 (c). Thereby, a laminated body is obtained. That is, (a) to (c) are manufacturing processes of the laminated body.

The gasket substrate 12 may be obtained by pasting the gasket material 1 and the plastic film 2 having an adhesive layer in advance.
Next, the electrode catalyst layer 50, the transfer base material 10, and the gasket material 1 are cut from the laminated electrode catalyst layer 50 with a blade or the like so as to have cut portions having the same shape (d). Next, the electrode catalyst layer 50 and the outer peripheral portion of the cut portion of the transfer substrate 10 are removed from the gasket material 1 to obtain a convex transfer film 11 (e).

  After the transfer film 11 is obtained in the same manner using the anode catalyst ink and the cathode catalyst ink, respectively, the anode transfer film 11 and the cathode transfer film 11 are arranged so as to form a mirror image with the solid polymer electrolyte membrane 4 interposed therebetween. Press (f). After the heat pressing, the transfer substrate 10a is removed from the electrode catalyst layer 50a of the transfer film 11, and the plastic film 2 having the adhesive layer is removed from the frame-shaped gasket material 1a in contact with the solid polymer electrolyte membrane 4 (g). A membrane electrode assembly 5 is obtained (h).

  The solid polymer electrolyte membrane 4 is a polymer material that exhibits good proton conductivity in a wet state. The transfer substrate 10 is a plastic film. Moreover, the gasket material 1 and the plastic film 2 having an adhesive layer are films having an adhesive layer. The catalyst ink 3 is formed of powdered carbon carrying a catalyst made of platinum or an alloy of platinum and another metal and a resin, and forms an electrode catalyst layer 50 by drying and solidification.

Hereinafter, although the specific example of the material which comprises the plastic film 2 which has the solid polymer electrolyte membrane 4, the electrode catalyst layer 50, the transfer base material 10, the gasket material 1, and the adhesion layer is given, this invention is not limited to these.
Specifically, a hydrocarbon polymer electrolyte and a fluorine polymer electrolyte can be used as the polymer material constituting the solid polymer electrolyte membrane 4. As the hydrocarbon polymer electrolyte membrane, electrolyte membranes such as sulfonated polyether ketone, 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, Gore Select (registered trademark) manufactured by Gore, etc. can be used. The hydrocarbon-based electrolyte membrane is more preferable to apply the catalyst ink to the solid electrolyte membrane because it has less soaking and swelling into the solvent than the fluorine-based polymer electrolyte. The thickness of the solid polymer electrolyte membrane 4 is formed to be about 5 μm to 300 μm.

As resin which comprises the electrode catalyst layer 50, the thing similar to the said polymeric material can be used.
The catalyst constituting the electrode catalyst layer 50 includes platinum, palladium, ruthenium, iridium, rhodium, osmium, platinum group elements, iron, lead, copper, chromium, cobalt, nickel, manganese, vanadium, molybdenum, gallium. Further, a metal such as aluminum or platinum and an alloy thereof, or an oxide or a double oxide thereof can be used. Among these, platinum and platinum alloys are more preferable.

  Moreover, since the activity of a catalyst will fall when the particle size of a catalyst is too large, and stability of a catalyst will fall when it is too small, 0.5 nm or more and 20 nm or less are preferable. Further, the powder carbon constituting the electrode catalyst layer 50 is not particularly limited as long as it is in the form of fine particles and 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 about 10 nm to 100 nm smaller than the catalyst.

The electrode catalyst layer 50 can be obtained by applying and drying the catalyst ink 3 prepared by dispersing the materials in a solvent and water on the transfer substrate 10. As the solvent, alcohols such as 1-propanol and 2-propanol may be used in order to disperse the material appropriately, but a solvent having a boiling point lower than that of water is more preferable because it can be easily dried.
As a material constituting the transfer substrate 10, the electrode catalyst layer 50 can be formed on the surface thereof, and the formed electrode catalyst layer 50 can be transferred to the solid polymer electrolyte membrane 4 and removed from the adhesive layer of the gasket material 1. There is no particular limitation. Examples of the material constituting the transfer substrate 10 include the following materials.

Polymer films such as polyimide, polyethylene terephthalate, polyparvanic acid aramid, polyamide (nylon), polysulfone, polyethersulfone, polyethersulfone, polyphenylene sulfide, polyetheretherketone, polyetherimide, polyacrylate, polyethylene naphthalate.
Moreover, heat resistant fluororesins such as ethylene tetrafluoroethylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroperfluoroalkyl vinyl ether copolymer, and polytetrafluoroethylene can also be used.

The coating apparatus for forming the electrode catalyst layer 50 on the transfer substrate 10 may be any apparatus that can apply the catalyst layer with a uniform thickness, and a system such as a die coater system or a roll coater system can be used.
The base material layer of the plastic film 2 having the gasket material 1 and the adhesive layer is not particularly limited as long as it has heat resistance that does not melt at the time of heat and pressure, but the following materials can be exemplified. Polymer films such as polyethylene naphthalate, polyethylene terephthalate, polyimide, polyparvanic acid aramid, polyamide (nylon), polysulfone, polyethersulfone, polyethersulfone, polyphenylene sulfide, polyetheretherketone, polyetherimide, polyacrylate.

  Moreover, heat resistant fluororesins such as ethylene tetrafluoroethylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroperfluoroalkyl vinyl ether copolymer, and polytetrafluoroethylene can also be used. In consideration of gas barrier properties and heat resistance, the base material in the gasket material 1 is particularly preferably polyethylene naphthalate.

The pressure-sensitive adhesive layer of the plastic film 2 having the gasket material 1 and the pressure-sensitive adhesive layer may be an acrylic, urethane-based, silicone-based, rubber-based pressure-sensitive adhesive, and the adhesion between the base material layer and the solid polymer electrolyte membrane 4. In view of the heat resistance at the time of heat pressurization, it is more preferable to use acrylic.
The adhesiveness of the adhesive layer of the gasket material 1 and the plastic film 2 having the adhesive layer is ““ adhesion between the solid polymer electrolyte membrane 4 and the gasket material 1 ”>“ between the gasket material and the plastic film 2 having the adhesive layer ”. It is preferable to satisfy “adhesion” ”because it is easy to join the gasket material 1 to the membrane electrode assembly 5.

  In the process for forming the cut portion in the transfer film 11, the electrode catalyst layer 50 having the cut portion having an excellent shape and size can be obtained by performing a process using a blade mold such as a punching process. At this time, the blade mold needs to penetrate to the electrode catalyst layer 50, the transfer base material 10, and the gasket material 1 and cut. Thereby, the gap between the electrode catalyst layer 50 of the membrane electrode assembly 5 and the gasket material 1 can be eliminated by simultaneously cutting the electrode catalyst layer 50 and the gasket material 1 into the same shape.

At this time, if the cutting is performed up to the plastic film 2 having the adhesive layer, the electrode catalyst layer 50 may fall out of the transfer film 11, and a displacement occurs between the gasket material 1 and the catalyst layer 50. Resulting in. A gap or a climbing portion is generated due to the positional deviation, and an exposed portion of the polymer electrolyte membrane is generated in the membrane electrode assembly 5, which is not preferable.
In addition, when the method of peeling the mask material is used without cutting as in the present invention, the cross-sectional shape may be lost and the adhesion may be impaired, or a partial peeling may occur and a problem may occur during power generation. .

Since the heating temperature in the heat pressurization is in the vicinity of the softening point of the polymer material contained in the electrode catalyst layer 50 and the solid polymer electrolyte membrane 4, it may be 70 to 200 ° C. The method of heat pressurization may be flat or roll.
In the manufacturing method of the membrane electrode assembly, it is preferable that all processes are continuous in consideration of manufacturing efficiency, but all processes may be discontinuous in consideration of the yield of the coating process of the electrode catalyst layer 50.

According to the manufacturing method of the membrane electrode assembly described above, there is no exposed portion of the electrolyte membrane 4 between the electrode catalyst layer 50 on the solid polymer electrolyte membrane 4 and the gasket material 1 on the outer periphery of the electrode catalyst layer 50. In addition to the performance degradation due to gas leaks and dimensional changes, there is no part of the gasket material 1 that rides on the catalyst layer, so the membrane electrode assembly manufacturing apparatus and the method of manufacturing the membrane electrode assembly 5 with high catalyst utilization efficiency Can be provided.
Examples of the present invention and comparative examples will be specifically described below. However, the present invention is not limited to the following examples.

<Manufacture of membrane electrode assembly>
[Example]
A fluororesin film (FLUON AFLEX 50N (NT) manufactured by Asahi Glass Co., Ltd., thickness 50 μm) was prepared as the transfer substrate 10.
On this transfer substrate 10, by a die coater method, a fluorine-based polymer electrolyte membrane dispersion solution (SS700C / 20 manufactured by Asahi Kasei E-Materials), a platinum catalyst (TEC “10F30E-HT” manufactured by Tanaka Kikinzoku), 1-propanol Catalyst ink 3 made of water was applied with a die coater. Next, the anode electrode catalyst layer 50 was formed on the transfer substrate 10 by drying at a temperature of 90 ° C. for 10 minutes. The anode electrode catalyst layer 50 was formed in the center of the transfer substrate 10 in a square planar shape of about 8 cm × 8 cm. In this way, the state shown in FIG.

Moreover, the electrode catalyst layer 50 for cathodes was formed on the transfer base material 10 like the above except having changed the platinum catalyst (TEC "10F50E-HT" made from Tanaka Kikinzoku).
As the gasket material 1, a material comprising a polyethylene naphthalate film (Teonex Q51 made by Teijin DuPont Film, thickness 25 μm) and an acrylic adhesive layer (thickness 10 μm) formed on one surface was prepared. Further, as the substrate 2, a plastic film (Kimoto Prosave 25CBFS2, thickness 27.5 μm) having an acrylic adhesive layer on polyethylene terephthalate was prepared. The gasket substrate 12 was prepared by pasting the back surface of the gasket material 1 (the surface without the adhesive layer) to the adhesive layer of the substrate 2 in advance.

The gasket substrate 12 is attached to the back surface (surface without the electrode catalyst layer 50) of each transfer substrate 10 on which the anode catalyst layer and the cathode electrode catalyst layer 50 are respectively formed, and the state shown in FIG. A laminate was obtained. In this state, an adhesive layer exists between the transfer base material 10 and the gasket material 1, and an adhesive layer also exists between the gasket base material 1 and the substrate 2.
Next, by punching the laminated body shown in FIG. 1C into a 5 cm × 5 cm square blade mold from the electrode catalyst layer 50 to the trouble of the substrate 2, the electrode catalyst layer 50 and the transfer group are formed. The material 10 and the gasket material 1 were cut. The punching process was performed by adjusting the amount of pressing of the blade mold so that the gasket material 1 was cut and the substrate 2 was not cut. As a result, the state shown in FIG.

Next, the portion outside the cut line between the electrode catalyst layer 50 and the transfer base material 10 is removed so that the adhesive layer remains on the gasket material 1 between the transfer base material 10 and the gasket material 1. A transfer film 11 for cathode was obtained. That is, the state shown in FIG.
As shown in FIG. 1 (e), the gasket layer 1 of the obtained transfer film 11 has a cut line 13 that matches the outline of the planar shape of the electrode catalyst layer formed on the membrane electrode assembly 5 and the substrate 2. To the boundary position. The electrode catalyst layer 50 a and the transfer substrate 10 a of the transfer film 11 have an outer surface that matches the score line 13.

The obtained anode transfer film 11 and cathode transfer film 11 are aligned with the front and back surfaces (one surface and the other surface opposite to each other) of the solid polymer electrolyte membrane 4 made of a hydrocarbon film (thickness 11 μm). Then, the plate was hot-pressed at a pressure of 0.8 MPa and a temperature of 170 ° C. for 10 minutes. That is, the process shown in FIG.
As a result, a 5 cm × 5 cm square anode electrode catalyst layer 50 a is bonded to the center of one surface of the solid polymer electrolyte membrane 4, and 5 cm × 5 cm formed by a score line on the outside of the anode electrode catalyst layer 50 a. A frame-shaped gasket material 1a having a square inner surface was joined. Further, a 5 cm × 5 cm square cathode electrode catalyst layer 50 a is bonded to the center of the other surface of the solid polymer electrolyte membrane 4, and 5 cm × 5 cm formed by a cut line outside the cathode electrode catalyst layer 50 a. A frame-shaped gasket material 1a having a square inner surface was joined.

  Next, as shown in FIG. 1G, the transfer base material 10a was peeled off from each electrode catalyst layer 50a, and the substrate 2 was peeled off from each frame-shaped gasket material 1a. The adhesive layer of the substrate 2 was left on the substrate 2 side. Thus, a membrane electrode assembly in which a square catalyst layer (anode catalyst layer, cathode catalyst layer) 50a and a frame-like gasket material 1a are formed on the opposite surfaces of the solid polymer electrolyte membrane 4 5 was obtained. The electrode catalyst layer 50a is disposed at the center of the solid polymer electrolyte membrane 4, the frame-shaped gasket material 1a is disposed around the electrode catalyst layer 50a, and the outer shape surface of the electrode catalyst layer 50a and the inner shape surface of the gasket material 1a are formed. In contact.

[Comparative example]
FIG. 2 shows, as a comparative example, a method for manufacturing a membrane / electrode assembly using the same material as in the example as in Patent Document 2. In the same manner as in the example, the anode and cathode catalyst inks 3 were applied and dried on the fluororesin film used as the transfer substrate 10 to form electrode catalyst layers 50, respectively (a) and (b).

Next, after making a frame-shaped gasket material 1 having a square opening of 5 cm × 5 cm in advance by punching, the gasket material 1 is formed on the opposite surfaces of the solid polymer electrolyte membrane 4. It arrange | positions so that the position of opening may correspond in the front and back of the solid polymer electrolyte membrane 4, and it bonds through an adhesion layer (c).
The electrode catalyst layer 50 obtained in (b) was placed on the surface of the gasket material 1 in (c), and flat plate hot pressing was performed at a pressure of 0.8 MPa and a temperature of 170 ° C. for 10 minutes (d). Thereafter, as shown in (e), the transfer substrate was removed to obtain a membrane electrode assembly 5 in which the catalyst layers were bonded to both surfaces.

<Evaluation of membrane electrode assembly>
For the membrane electrode assemblies of Examples and Comparative Examples thus obtained, the presence or absence of the gasket material on the catalyst layer, the presence or absence of transfer failure of the catalyst layer, the presence or absence of the exposed portion of the electrolyte membrane, unnecessary catalyst The presence or absence of transfer of the layer and the appearance of the membrane electrode assembly were evaluated. The results are shown in Table 1.

  As shown in Table 1, in the membrane electrode assemblies obtained by the methods of Examples and Comparative Examples, the gasket material did not run on the catalyst layer. In the examples, no transfer failure of the catalyst layer occurred. However, in the comparative example, since it must be transferred to the recessed electrolyte membrane by the frame-shaped gasket material, the pressure is not sufficiently applied to the electrolyte membrane portion, and a partial transfer failure occurred in the vicinity of the electrolyte membrane. In addition, only in the comparative example, an exposed portion of the solid polymer electrolyte membrane was formed due to poor transfer.

Further, in the example, the catalyst layer was transferred in a desired shape, but in the comparative example, as shown in FIG. 2 (f) a, the occurrence of divergence between the catalyst layer and the solid polymer electrolyte membrane, or FIG. (F) Occurrence of a cross leak due to the presence of a gap between the gasket material and the catalyst layer as shown in (b), and partial transfer of the catalyst layer on the gasket material as shown in FIG. 2 (f) c. It was.
Furthermore, the membrane / electrode assembly obtained in the examples had a good appearance with flatness without wrinkles or distortion, but in the comparative example, strong heat and pressure were preferentially applied to the gasket material, resulting in poor appearance due to wrinkles. Had occurred.

1 Gasket material (gasket layer)
1a Frame-shaped gasket material (frame-shaped gasket layer)
2 Plastic film (substrate)
3 Catalyst ink 4 Solid polymer electrolyte membrane (polymer electrolyte membrane)
DESCRIPTION OF SYMBOLS 5 Membrane electrode assembly 10 Transfer base material 10a Transfer base material of transfer film 11 Transfer film 12 Gasket substrate 13 Cut line 50 Electrode catalyst layer 50a Electrode catalyst layer of transfer film

Claims (5)

A method for producing a membrane electrode assembly, comprising: a polymer electrolyte membrane; and an electrode catalyst layer formed in a predetermined planar shape on opposite surfaces of the polymer electrolyte membrane,
A substrate, a gasket layer bonded onto the substrate, a transfer substrate bonded onto the gasket layer, and an electrode catalyst layer formed on the transfer substrate, the gasket layer comprising: A cut line that matches the outline of the planar shape has a boundary position with the substrate, and the electrode catalyst layer and the transfer base material have an outline that matches the cut line and matches the planar shape. Using a transfer film present on the gasket layer in a shape to
After thermocompression bonding the electrode catalyst layer and the gasket layer of the transfer film toward the surface of the polymer electrolyte membrane,
By peeling the transfer base material from the electrode catalyst layer and peeling the frame-shaped gasket layer existing outside the cut line from the substrate,
A method for producing a membrane electrode assembly, wherein the planar electrode catalyst layer and the frame-shaped gasket layer are transferred from the transfer film to the surface of the polymer electrolyte membrane. The transfer film,
A substrate; a gasket layer bonded on the substrate; a transfer base material bonded on the gasket layer; and an electrode catalyst layer formed on the transfer base material. A laminate in which the planar shape of the layer, the transfer substrate, and the electrode catalyst layer is larger than the planar shape of the electrode catalyst layer formed in the membrane electrode assembly,
From the electrode catalyst layer side of the laminate to the boundary position with the substrate of the gasket layer, after cutting with a score line that matches the planar outline of the electrode catalyst layer formed in the membrane electrode assembly, The manufacturing method of the membrane electrode assembly of Claim 1 including the process manufactured by peeling the said transcription | transfer base material outside a cut line from the said gasket layer.   The manufacturing method of the said laminated body is a manufacturing method of the membrane electrode assembly of Claim 2 performed by the method including the process of joining the said gasket layer with respect to the said transfer base material in which the said electrode catalyst layer was formed.   The method for producing a membrane / electrode assembly according to claim 2, wherein the laminate is produced by a method including a step of forming the electrode catalyst layer on the transfer substrate to which the gasket layer is bonded. A membrane electrode assembly comprising a polymer electrolyte membrane and an electrode catalyst layer formed in a predetermined planar shape on opposite surfaces of the polymer electrolyte membrane,
A frame-like gasket layer having an inner surface that matches the outer shape line of the planar shape is formed outside the electrode catalyst layer on the surface of the polymer electrolyte membrane,
A membrane electrode assembly in which an outer surface of the electrode catalyst layer is in contact with an inner surface of the gasket layer.

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