JP2018077980A - Method of manufacturing membrane electrode assembly - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a membrane electrode assembly in which, in a manufacturing process of the membrane electrode assembly used in a fuel cell, warpage occurs in a substrate and the membrane electrode assembly and reduction in quality is suppressed.SOLUTION: Disclosed is a method of manufacturing a membrane electrode assembly including a catalyst layer, a solid polymer electrolyte membrane, a gasket material, and a support base material. At least one of angles in the flow direction of the solid polymer electrolyte membrane, the gasket material and the support base material with respect to the traveling direction of a pressure roller is not zero degree.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a method for producing a membrane electrode assembly which is a constituent member of a polymer electrolyte fuel cell.

A fuel cell is a power generation system that converts a chemical energy of a fuel into electric energy and extracts it by electrochemically reacting a fuel such as hydrogen with an oxidant such as air. This power generation method is expected to be a new energy because of its advantages such as high power generation efficiency, excellent quietness, NOx and SOx that cause air pollution, and low CO ₂ emissions that cause global warming. ing. Examples of the application of this fuel cell include a long-time power supply for portable electric devices, a stationary generation hot water supply machine for cogeneration, a fuel cell vehicle, and the like, which have various uses and scales.

  The types of fuel cells are classified into solid polymer type, phosphoric acid type, molten carbonate type, solid oxide type, alkaline type, etc. depending on the electrolyte used. Is also different.

  The one using a cation exchange membrane as an electrolyte is called a polymer electrolyte fuel cell, and can operate at a relatively low temperature among fuel cells, and the internal resistance can be reduced by reducing the thickness of the electrolyte membrane. Therefore, high output and compactness are possible, and it is considered promising for use as a vehicle-mounted source or a household stationary power source.

  A polymer electrolyte fuel cell has a membrane electrode assembly (MEA) called a membrane electrode assembly (MEA) in which a pair of electrode catalyst layers are disposed on both sides of an electrolyte membrane, and a fuel gas containing hydrogen is applied to one of the electrodes. The battery is sandwiched between a pair of separator plates formed with a gas flow path for supplying and supplying an oxidant gas containing oxygen to the other electrode. A battery sandwiched between the pair of separator plates is called a single battery cell.

  A polymer electrolyte fuel cell is used by stacking a plurality of unit cells for the purpose of increasing power density and making the entire fuel cell compact. The number of stacks varies depending on the power required. For portable power sources of general portable electric devices, several to about 10 sheets, for cogeneration stationary electric and hot water supply machines, about 60 to 90 sheets, and for automobile applications, 250 sheets. From about 400 to 400. In order to increase the output, it is necessary to increase the number of stacks, and the cost of the unit cell greatly affects the cost of the entire fuel cell.

  As a method for producing a membrane / electrode assembly, a method has been proposed in which a catalyst layer supported on a transfer substrate is thermocompression bonded to a solid polymer electrolyte membrane by hot pressing or thermal lamination, and then the transfer substrate is peeled off.

  For example, Patent Document 1 discloses a technique using a hot press, and Patent Document 2 discloses a technique using a thermal laminate. The hot press method is a method of manufacturing a membrane electrode assembly by placing a solid polymer electrolyte membrane and a catalyst layer supported on a transfer substrate on both sides thereof and sandwiching the membrane between a pair of flat plates and thermocompression bonding. The thermal laminating method is a method in which a solid polymer electrolyte membrane and a long catalyst layer-supporting substrate carrying a catalyst layer disposed on both sides thereof are brought into contact with each other and thermally bonded by a pair of heat laminating rolls. This is a method of manufacturing a joined body.

Japanese Patent Laying-Open No. 2015-133337 JP, 2006-076366, A Japanese Patent Laid-Open No. 9-19964

  However, the membrane / electrode assembly obtained by the hot pressing method or the thermal laminating method described in Patent Document 1 or Patent Document 2 is affected by residual stress and thermal history during bonding and thermocompression bonding, or a solid polymer electrolyte. It has warping due to various external and internal factors such as the influence of the storage state of each member such as a film and a transfer substrate, and has a problem of deteriorating the appearance and power generation performance.

  Here, besides the field of fuel cells, there is a field where improvement of warpage is an issue. For example, in Patent Document 3, in the field of laminated base materials, a base material having directionality is produced, and the base materials having the fiber direction are laminated so that the inter-fiber direction is 90 °. It is disclosed that warpage is reduced.

  However, the method of Patent Document 3 relates to a method for manufacturing a laminated substrate, and even if the method of Patent Document 3 is applied to a method for manufacturing a membrane electrode assembly of a fuel cell, the flow direction of the substrate or a pressure roller It is difficult to adapt to the direction of travel, and it is difficult to reduce warpage.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a method for manufacturing a membrane electrode assembly with reduced warpage.

As a means for solving the above problems, the first aspect of the present invention is:
A method for producing a membrane electrode assembly comprising a catalyst layer, a solid polymer electrolyte membrane, a gasket material, and a supporting substrate, wherein at least a coating step of applying a catalyst ink to a transfer substrate, and the catalyst of the transfer substrate Including a bonding step of bonding the gasket material and the support substrate to a surface on which ink is not applied, and a thermocompression bonding step of thermocompression bonding the catalyst ink to the solid polymer electrolyte membrane, the bonding step Then, when the advancing direction of the pressure roller is the y-axis direction, the angle formed by the flow direction of the support base material and the y-axis direction is α on the cathode side and γ on the anode side, and the gasket The angle formed between the flow direction of the material and the y-axis direction is β on the cathode side and φ on the anode side, and the angle formed between the flow direction of the solid polymer electrolyte membrane and the y-axis direction is θ. And α, β, γ, In the method for manufacturing a membrane electrode assembly, at least one of φ and θ is not 0 degree.

  According to the present invention, it is possible to reduce the warpage of the membrane electrode assembly as compared with the conventional transfer method without changing the existing catalyst ink or the like.

It is a block diagram by the side of the cathode catalyst layer which concerns on a prior art. It is a block diagram by the side of the anode catalyst layer which concerns on a prior art. It is a block diagram of the membrane electrode assembly which concerns on a prior art. It is a block diagram which shows the manufacturing method of the membrane electrode assembly which concerns on embodiment of this invention. It is a block diagram which shows the manufacturing method of the membrane electrode assembly which concerns on embodiment of this invention. It is a schematic diagram explaining the definition of the curvature of the membrane electrode assembly which concerns on embodiment of this invention. It is a block diagram which shows the manufacturing method of the catalyst layer which concerns on embodiment of this invention. It is a block diagram which shows the manufacturing method of the membrane electrode assembly which concerns on embodiment of this invention.

  Embodiments of the present invention 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 made based on the knowledge of those skilled in the art, and such modifications have been added. Embodiments are also included in the scope of the embodiments of the present invention. Each figure is exaggerated as appropriate for explanation.

  Hereinafter, an embodiment of the present invention will be described by comparing with the prior art. In each drawing, the direction in which the catalyst layer 1 (5), the transfer base material 2, the gasket material 3, and the support base material 4 are laminated is defined as the z-axis direction, and a pressure roller that pressurizes each constituent member ( The advancing direction (not shown) is defined as the y-axis direction, and the direction perpendicular to the y-axis direction and the z-axis direction is defined as the x-axis direction.

(Conventional technology)
1 to 3 show an example of a conventional technique in a method for manufacturing a membrane electrode assembly.
FIG. 1A shows a cathode side member, that is, a cathode catalyst layer 1, a gasket material 3 having a frame hole having the same shape as the cathode catalyst layer 1, and a support base material 4. FIG.1 (b) has shown xz sectional drawing of Fig.1 (a).

  FIG. 2 shows members on the anode side. That is, FIG. 2A shows the anode catalyst layer 5, the gasket material 3 having the same shape as the anode catalyst layer 5, and the support base 4. FIG. 2B shows an xz sectional view of FIG.

  FIG. 3 shows an example of a conventional method for manufacturing a membrane electrode assembly. A catalyst layer 1 (5), a gasket material 3 and a supporting substrate 4 on the cathode side shown in FIG. 1 and the anode side shown in FIG. 2 are arranged on both surfaces of the solid polymer electrolyte membrane 6, respectively, and a pressure roller Is manufactured by bonding. FIG. 3B shows an xz sectional view of FIG.

Here, on the xy plane, the angle formed by the flow direction of the gasket material 3 and the flow direction of the support base material 4 on the cathode side in the clockwise direction and the clockwise direction of the pressure roller is β and α, respectively. Define the angles that the flow direction of the gasket material 3 and the flow direction of the support base material 4 on the anode side on the xy plane form the pressure roller traveling direction (y-axis direction) and clockwise, respectively, as φ and γ, respectively. To do. Similarly, an angle formed by the flow direction of the solid polymer electrolyte membrane 6 on the xy plane in the clockwise direction with the traveling direction of the pressure roller (y-axis direction) is defined as θ.
In addition, the flow direction here refers to the flow direction of the manufacturing process in the roll to roll of the gasket material 3, the support base material 4, and the solid polymer electrolyte membrane 6, and corresponds with the uniaxial stretching direction by roll stretching.

  As shown in FIGS. 1 to 3, in the prior art, each member is manufactured in a state parallel to the traveling direction of the pressure roller (the y-axis direction in the figure). In other words, in the prior art, the α, β, γ, φ, θ are bonded by the pressure roller in a state where they are set to approximately 0 degrees.

  There are various causes of warpage during the manufacture of membrane electrode assemblies, but the storage state of each member such as the solid polymer electrolyte membrane and transfer substrate before production is one of the causes of warpage, and the degree of influence is high it is conceivable that. That is, when manufacturing a membrane electrode assembly by roll-to-roll, the transfer base material 2, the gasket material 3, and the support base material 4 are generally provided in a roll state. For this reason, the member may have a curl, and warping due to this occurs.

  In particular, as shown in FIGS. 1 to 3, in the prior art, α, β, γ, φ, and θ are all substantially 0 degrees (substantially parallel) with respect to the pressure roller when the membrane electrode assembly is manufactured. For this reason, since the members are stacked in a state where the creases in the same direction are attached, there is a problem in that the warpage becomes conspicuous at the end of manufacture, and the appearance and power generation performance are impaired.

(One embodiment of the present invention)
4A and 4B show a method for manufacturing a membrane electrode assembly according to an embodiment of the present invention. FIG. 4A shows the cathode side, and FIG. 4B shows the anode side. That is, the manufacturing method of the membrane electrode assembly of the present invention has the following configuration.

  FIG. 4A shows the cathode side, which includes a cathode catalyst layer 1, a transfer substrate 2, a gasket material 3, and a support substrate 4. FIG. 4B shows the anode side, and includes an anode catalyst layer 5, a transfer substrate 2, a gasket material 3, and a support substrate 4. As shown in FIG. 5, the membrane / electrode assembly has the catalyst layer 1 (5), gasket material 3 and supporting substrate shown in FIGS. 4 (a) and 4 (b) on both sides of the solid polymer electrolyte membrane 6. 4 is provided.

  Here, an angle formed by the flow direction of the transfer base material 2, the gasket material 3, the support base material 4, and the polymer electrolyte membrane 6 and the traveling direction (y-axis direction) of the pressure roller, which is a feature of the embodiment of the present invention. The definition will be described with reference to FIGS.

That is, the present invention is characterized in that α, β, γ, φ, and θ are manufactured at different angles with respect to the traveling direction of the pressure roller, as shown in FIGS.
Since α, β, γ, φ, and θ are laminated at different angles with respect to the traveling direction of the roller, these warpages are averaged at the end of production. Therefore, it becomes possible to manufacture a membrane electrode assembly with reduced warpage.

  Here, if the angles α, β, γ, φ, and θ are different from each other with respect to the traveling direction of the roller, the effect of the present invention can be obtained. In particular, it is preferable that the angle of each angle is 60 ° or more and 120 ° or less because the warpage of the membrane / electrode assembly is easily reduced, and when θ is approximately 90 °, it can be most preferably manufactured. On the other hand, when α, β, γ, φ, and θ are absolute values of less than 60 ° or more than 120 °, the transfer substrate 2, gasket material 3, support substrate 4, and solid polymer electrolyte membrane 6 flow in the flow direction. On the other hand, the relaxation of the pressure applied to the warp generated is reduced, and the degree of reduction of the warp is reduced.

  Furthermore, the material used for the solid polymer electrolyte membrane 6, the gasket material 3, and the support substrate 4 includes a step of winding with a roller in the manufacturing process, and has anisotropy and warping with respect to the direction of winding with the roller. Therefore, the materials used for the solid polymer electrolyte membrane 6, the gasket material 3, and the support base material 4 should have anisotropy in the flow direction (y-axis direction) and the width direction (x-axis direction) of the pressure roller. Therefore, the solid polymer electrolyte membrane 6, the gasket material 3, and the support base material 4 can be reduced because the warpage that has occurred can be reduced.

Here, with reference to FIG. 6, the quantification of the curvature of the membrane electrode assembly in one Embodiment of this invention is defined.
As shown in FIG. 6, the surface of the membrane electrode assembly facing the warp is placed on the upper surface and placed on a horizontal base. The height of both ends of the membrane electrode assembly from the horizontal base is defined as a and b, and the value obtained by dividing the sum of a and b by 2 is defined as the amount of warpage, which is an evaluation item.

(Catalyst layer manufacturing process)
Next, the manufacturing process of a catalyst layer is demonstrated with reference to FIG.
In the production of the catalyst layer, first, a coating process for coating the transfer substrate 2 with the catalyst ink is performed. The catalyst ink may be applied by a known technique, for example, die coating or spray coating.

  Subsequently, as shown in FIG. 7A, a bonding process is performed in which the surface of the transfer base material 2 on which the catalyst ink is not applied, the gasket material 3, and the support base material 4 are laminated and bonded. In the bonding step, the pressure roller is advanced in the y-axis direction, and the transfer base material 2, the gasket material 3, and the support base material 4 having different α, β, γ, φ, and θ are laminated and pressed. While pasting. At that time, it is preferable to perform pressure bonding so that there are no bubbles between the transfer substrate 2 and the gasket material 3.

The roller pressure at the time of bonding is, for example, from 0.01 MPa to 100 MPa, preferably from 0.05 MPa to 50 MPa, and more preferably from 0.1 MPa to 10 MPa. In the case of the above range, the transferred catalyst layer structure is not too dense, and an effect that flooding hardly occurs can be obtained.
Moreover, the roller traveling speed at the time of the above bonding is, for example, 0.01 mm / s or more and 100 mm / s or less, preferably 0.05 mm / s or more and 50 mm / s or less, more preferably 0.1 mm / s or more and 10 mm / s or less. If so, it is preferable to obtain effects such as reduction of warpage of the base material caused by speed and defoaming of air between the base materials.

  A cutting process is performed after the bonding process. The cutting process includes a punching process and a removal process. The punching process is a process in which the catalyst layer 1 (5), the transfer substrate 2 and the gasket material 3 are cut from the catalyst layer surface side so as to be discontinuous surfaces, as shown by the dotted line in FIG. is there. That is, in the process for imparting a discontinuous surface to the transfer substrate 2, the catalyst layer 1 (5) having a discontinuous surface excellent in shape and size is obtained by performing a process using a blade type such as a punching process. Can be obtained. At this time, it is necessary to cut the blade mold so as to penetrate the catalyst layer 1 (5), the transfer base material 2 and the gasket material 3 so as to be discontinuous. By cutting the catalyst layer 1 (5) and the gasket material 3 simultaneously in the same shape, a gap can be eliminated between the catalyst layer 1 (5) and the gasket material 3 when forming the membrane electrode assembly. As a result, it is possible to obtain an effect of suppressing leakage of gas that is fuel of the fuel cell. Thereafter, as shown in FIG. 7B, the gasket 3 is exposed by peeling off and removing only the transfer substrate 2a on the outside of the cut surface and the catalyst layer 1 (5) adhering to the upper part. I can do it.

  In the punching process, if the support substrate 4 having the adhesive layer is cut, the catalyst layer 1 (5) may fall off the transfer substrate 2, and the gasket material 3 and the catalyst layer 1 ( A position shift occurs during 5). A gap or a climbing portion is generated due to the displacement, and an exposed portion of the polymer electrolyte membrane 6 is generated in the membrane electrode assembly, which is not preferable.

  After the cutting process, a thermocompression bonding process is performed in which the laminated transfer substrate 2 and the like are thermocompression bonded to the polymer electrolyte membrane 6. As shown in FIG. 8, after aligning the catalyst layer 1 (5) on the cathode side and the anode side, the membrane electrode assembly can be obtained by thermocompression bonding from the support substrate 4 side. The thermocompression bonding apparatus is preferably a heat laminating method (thermal laminating process) or a hot pressing system (hot pressing process) using a roll because uniform heating and uniform pressing are easy. If the temperature at the time of thermocompression bonding is not less than the softening temperature of the solid polymer electrolyte membrane 6 and not more than the heat resistance temperature, the solid polymer electrolyte membrane 6 is not thermally deteriorated and a favorable membrane electrode assembly can be obtained.

  The roller pressure at the time of thermocompression bonding is, for example, from 0.01 MPa to 100 MPa, preferably from 0.05 MPa to 50 MPa, and more preferably from 0.1 MPa to 10 MPa.

Below, the detail of each member is demonstrated.
The polymer electrolyte membrane 6 used for the membrane electrode assembly may be any one having proton conductivity, and a fluorine-based polymer electrolyte, a hydrocarbon-based polymer electrolyte, or the like can be used. In addition, as the fluorine-based polymer electrolyte, for example, Nafion (registered trademark) manufactured by DuPont, Flemion (registered trademark) manufactured by Asahi Glass Co., Ltd., Aciplex (registered trademark) manufactured by Asahi Kasei Co., Ltd. or the like may be used. it can. Moreover, as the hydrocarbon polymer electrolyte membrane, for example, an electrolyte membrane such as sulfonated polyether ketone, sulfonated polyethersulfone, sulfonated polyetherethersulfone, sulfonated polysulfide, and sulfonated polyphenylene can be used. Among them, a material containing perfluorosulfonic acid as the fluorine-based polymer electrolyte can be suitably used as the polymer electrolyte membrane.

  The polymer electrolyte contained in the cathode catalyst layer 1 and the anode catalyst layer 5 may be any one having proton conductivity, and the same material as the polymer electrolyte membrane 6 can be used. Hydrocarbon polymer electrolytes and the like can be used. In addition, as a fluorine-type polymer electrolyte, the Dufon Nafion (trademark) type material etc. can be used, for example. Further, as the hydrocarbon polymer electrolyte membrane, for example, a polymer electrolyte membrane such as sulfonated polyether ketone, sulfonated polyethersulfone, sulfonated polyetherethersulfone, sulfonated polysulfide, sulfonated polyphenylene or the like is used. it can. Among these, a material containing perfluorosulfonic acid as the fluorine-based polymer electrolyte can be suitably used as the polymer electrolyte.

  The catalyst particles used in the present embodiment include platinum, palladium, ruthenium, iridium, rhodium, osmium, platinum group elements, iron, lead, copper, chromium, cobalt, nickel, manganese, vanadium, molybdenum, gallium, aluminum, and the like. These metals or their alloys can be used. In addition, oxides, double oxides, and the like can be used. The particle size of these catalysts is, for example, about 0.1 nm to 1 μm, preferably about 0.5 nm to 100 nm, and more preferably about 1 nm to 10 nm.

  Carbon particles are generally used as the conductive carrier for supporting these catalyst particles. Any kind of carbon particles may be used as long as they are in the form of fine particles, have conductivity and are not affected by the catalyst particles, such as carbon black, graphite, graphite, activated carbon, carbon fiber, carbon nanotube, fullerene, etc. Can be used.

  The solvent used as a dispersion medium for the catalyst ink can dissolve the polymer electrolyte in a highly fluid state or be dispersed as a fine gel without eroding the conductive carrier carrying the catalyst particles or the polymer electrolyte. There is no particular limitation as long as there is something.

  The solvent preferably includes a volatile organic solvent or water, and the organic solvent is not particularly limited, but methanol, ethanol, 1-propanol, 2-propanol, 1 Alcohols such as butanol, 2-butanol, isobutyl alcohol, tert-butyl alcohol, pentaanol, acetone, methyl ethyl ketone, pentanone, methyl isobutyl ketone, heptanone, cyclohexanone, methylcyclohexanone, acetonyl acetone, diisobutyl Ketone solvents such as ketones, ether solvents such as tetrahydrofuran, dioxane, diethylene glycol dimethyl ether, anisole, methoxytoluene, dibutyl ether, other dimethylformamide, dimethylacetamide, N-methylpyrrole Emissions, ethylene glycol, diethylene glycol, diacetone alcohol, 1-methoxy-2-propanol polar solvents such as are used. Moreover, what mixed 2 or more types of these solvents and water can also be used. A dispersant may be included.

  Moreover, the dispersion process at the time of producing catalyst ink can be performed using various apparatuses. For example, as the dispersion treatment, treatment with a ball mill or roll mill, treatment with a shear mill, treatment with a wet mill, ultrasonic dispersion treatment, and the like can be given. Moreover, you may use the homogenizer etc. which stir with centrifugal force.

  Any material that can transfer the catalyst layer to the solid polymer electrolyte membrane 6 may be used as the material constituting the transfer substrate 2. For example, polymers such as polyimide, polyethylene terephthalate, polyparvanic acid aramid, polyamide (nylon), polysulfone, polyethersulfone, polyethersulfone, polyphenylene sulfide, polyetheretherketone, polyetherimide, polyacrylate, polyethylene naphthalate A film can be used. Moreover, heat resistant fluororesins such as ethylene tetrafluoroethylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroperfluoroalkyl vinyl ether copolymer, and polytetrafluoroethylene can also be used.

  Any material can be used as the material constituting the transfer substrate 2 as long as the catalyst layer can be formed on the surface thereof. For example, polymers such as polyimide, polyethylene terephthalate, polyparvanic acid aramid, polyamide (nylon), polysulfone, polyethersulfone, polyethersulfone, polyphenylene sulfide, polyetheretherketone, polyetherimide, polyacrylate, polyethylene naphthalate A film can be used. 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 catalyst layer on the transfer substrate 2 is only required to be able to apply the catalyst layer with a uniform thickness, and a method such as a die coater method or a roll coater method can be used.

  The plastic film which has the gasket material 3 and the adhesion layer should just have the heat resistance of the grade which does not melt at the time of heat-pressing. For example, polymers such as polyethylene naphthalate, polyethylene terephthalate, polyimide, polypalvanic acid aramid, polyamide (nylon), polysulfone, polyethersulfone, polyethersulfone, polyphenylene sulfide, polyetheretherketone, polyetherimide, polyacrylate, etc. A film can be used. Moreover, heat resistant fluororesins such as ethylene tetrafluoroethylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroperfluoroalkyl vinyl ether copolymer, and polytetrafluoroethylene can also be used. The base material in the gasket material is particularly preferably polyethylene naphthalate in view of gas barrier properties and heat resistance.

  The pressure-sensitive adhesive layer of the plastic film having the gasket material 3 and the pressure-sensitive adhesive layer may be an acrylic, urethane-based, silicone-based, rubber-based pressure-sensitive adhesive, and the adhesion between the gasket material 3 and the solid polymer electrolyte membrane 6. In view of heat resistance at the time of heat pressurization, an acrylic type is more preferable. The adhesion of the adhesive layer of the plastic film having the gasket material and the adhesive layer is such that the adhesion between the solid polymer electrolyte membrane and the gasket material is greater than the adhesive force between the gasket material and the plastic film having the adhesive layer. It is preferable because it is easy to apply a gasket material to the joined body.

According to the method for manufacturing a membrane / electrode assembly described above, a membrane / electrode assembly in which the catalyst layer 1 (5) is bonded to both surfaces of the solid polymer electrolyte membrane 6 in a good shape can be manufactured.
Hereinafter, the present invention will be specifically described by way of examples. However, the present invention is not limited only to these examples.

(Modification)
In the above-described embodiment, the angles α, β, γ, φ, and θ of the gasket material 3, the support base material 4, and the solid polymer electrolyte membrane 6 are arranged so as to be different from each other. The present invention may be applied to other fuel cell members that are increased or decreased accordingly.
In addition, the effect of the present invention can be obtained by setting at least one of the angles α, β, γ, φ, and θ to be not 0 degrees (not parallel to the y-axis direction).

(Catalyst layer formation)
On the fluororesin film used as the transfer substrate 2, a die coater is used to apply a catalyst ink comprising a fluoropolymer electrolyte membrane dispersion solution (Nafion), a platinum catalyst, 1-propanol, and water with a die coater. The anode catalyst layer 5 was formed by drying at a temperature of 100 ° C. for 5 minutes. A cathode catalyst layer 1 was formed in the same manner except that the platinum catalyst was changed.

(Bonding process)
Transfer coated with polyester film with pressure-sensitive adhesive used as support base material 4, PEN film with acrylic pressure-sensitive adhesive film used as gasket material 3 (Teonex made by Teijin (registered trademark), thickness 12 μm) and catalyst layer 1 (5) The base material 2 was cut into a rectangular shape so that the flow direction of the substrate 2 coincided with the major axis direction.

  Next, α and β formed by the transfer base material 2, the gasket material 3 and the support base material 4 coated with the cathode catalyst layer 1, and the transfer base material 2, the gasket material 3 and the support base material coated with the anode catalyst layer 5. 4 was bonded by a pressure roller while changing γ and φ formed by 4. The pressure by the pressure roller was 1.0 MPa and the roller traveling speed was 5 mm / s.

(Cutting process)
Next, the sample obtained in the bonding step is punched from the catalyst layer side, and a 5 cm × 5 cm square is cut into the catalyst layer 1 (5), the transfer base material 2 and the gasket material 3, and the outer periphery fluorine The system resin film was removed.

(Thermo-compression process)
Nafion is used as the solid polymer electrolyte membrane 6, cut into a rectangle so that the flow direction of the solid polymer electrolyte membrane 6 coincides with the major axis direction, the solid polymer electrolyte membrane 6, the transfer substrate 2 on the cathode side, and the anode side The solid base height is such that the major axis directions of the transfer base material 2 are parallel to each other and the angle θ between the major axis direction of the solid polymer electrolyte membrane 6 and the traveling direction of the pressure roller is 90 °. The transfer substrate 2 on the cathode side and the transfer substrate 2 on the anode side are laminated on both surfaces of the molecular electrolyte membrane 6 and thermocompression bonded under conditions of 150 ° C. and 50 MPa by thermal laminating, and then the transfer substrate 2 and the support substrate 4 was peeled off to obtain a membrane electrode assembly.

(Evaluation results)
Table 1 summarizes the evaluation results obtained by changing α, β, γ, and φ. The amount of warpage was defined as described above, and was measured in units of 0.5 mm using a straight ruler.

  From the results of each example, the bonding is performed so that the angles formed between the support base 4, the gasket material 3, and the long axis direction of the solid polymer electrolyte membrane 6 are different from each other with respect to the traveling direction of the pressure roller. It can be confirmed that the membrane electrode assembly obtained by thermocompression bonding reduces the amount of warpage. Furthermore, a better result is obtained when the angle is not less than 60 ° and not more than 120 °. On the other hand, as shown in Comparative Example 1, it was confirmed that the membrane electrode assembly in the case where the angles of the members are the same has a large amount of warpage.

DESCRIPTION OF SYMBOLS 1 ... Cathode catalyst layer 2 ... Transfer base material 3 ... Gasket material 4 ... Support base material 5 ... Anode catalyst layer 6 ... Solid polymer electrolyte membrane

Claims (4)

A method for producing a membrane electrode assembly including a catalyst layer, a solid polymer electrolyte membrane, a gasket material, and a supporting substrate,
At least an application step of applying the catalyst ink to the transfer substrate;
A bonding step of bonding the gasket material and the support substrate to a surface of the transfer substrate on which the catalyst ink is not applied;
Including a thermocompression bonding step of thermocompression bonding the catalyst ink to the solid polymer electrolyte membrane,
In the pasting step,
When the traveling direction of the pressure roller is the y-axis direction,
The angle formed by the flow direction of the support substrate and the y-axis direction is α on the cathode side and γ on the anode side,
The angle formed between the flow direction of the gasket material and the y-axis direction is β on the cathode side and φ on the anode side,
An angle formed between the flow direction of the solid polymer electrolyte membrane and the y-axis direction is θ,
A method of manufacturing a membrane electrode assembly, wherein at least one of α, β, γ, φ, and θ is not 0 degree. Α, β, γ, φ, and θ are 60 ° or more and 120 ° or less as absolute values,
2. The method of manufacturing a membrane electrode assembly according to claim 1, wherein α, β, γ, φ, and θ are different from each other. Α, β, γ, φ, and θ are α <β <θ <φ <γ.
Or γ <φ <θ <β <α
Either of these is satisfy | filled, The manufacturing method of the membrane electrode assembly of Claim 1 or 2 characterized by the above-mentioned. Including a cutting step between the bonding step and the thermocompression bonding step,
In the cutting process,
From the catalyst layer surface side, a step of punching the catalyst layer, the transfer substrate, and the gasket material so as to be a discontinuous surface;
The film according to any one of claims 1 to 3, wherein a step of peeling and removing the transfer base material outside the discontinuous surface and the catalyst layer adhering to the upper portion is performed. Manufacturing method of electrode assembly.

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