JP5760607B2 - Membrane-electrode assembly, method for producing the same, and catalyst layer-electrolyte membrane laminate - Google Patents

Description

  The present invention relates to a membrane-electrode assembly and a method for producing the same.

  A fuel cell is a cell in which electrodes are arranged on both sides of an electrolyte and generates electricity by an electrochemical reaction between hydrogen and oxygen, and only water is generated during power generation. Thus, unlike the conventional internal combustion engine, it is expected to spread as a next-generation clean energy system because it does not generate environmental load gas such as carbon dioxide. In particular, polymer electrolyte fuel cells have a low operating temperature, low electrolyte resistance, and use a highly active catalyst, so they can achieve high output even in small sizes, and can be used for household cogeneration systems, etc. As soon as practical use is expected.

  In this polymer electrolyte fuel cell, as shown in Patent Document 1, a catalyst layer-electrolyte membrane laminate having a catalyst layer on both sides of an electrolyte membrane is formed, and a user in the state of this catalyst layer-electrolyte membrane laminate is provided. And a user stacks a laminate in which a conductive porous substrate is laminated on each catalyst layer of the catalyst layer-electrolyte membrane laminate from above and below with a separator or the like to form a stack.

JP 2006-216382 A

However, if the catalyst layer-electrolyte membrane laminate is supplied as described above, a step of laminating the conductive porous base material on each catalyst layer is required on the user side, which is disadvantageous in terms of convenience. In order to solve this problem, the conductive porous substrate is bonded to the catalyst layer by laminating the conductive porous substrate on the catalyst layer of the catalyst layer-electrolyte membrane laminate and performing hot pressing. In some cases, the membrane-electrode assembly thus formed is supplied to the user. However, by performing hot pressing, a pressure of about 10 to 200 kgf / cm ^{2 is} usually applied to the conductive porous substrate, so that the pores in the conductive porous substrate are crushed and gas diffusibility is reduced. There is also a problem. Then, this invention makes it a subject to provide the membrane-electrode assembly which improved the convenience, without reducing gas diffusibility.

  The membrane-electrode assembly according to the present invention includes an ion conductive polymer electrolyte membrane, a catalyst layer formed on both surfaces of the ion conductive polymer electrolyte membrane, and an adhesive layer formed on each catalyst layer. And a conductive porous substrate adhered on the catalyst layer via the adhesive layer.

According to this membrane-electrode assembly, since the conductive porous substrate is bonded onto the catalyst layer via the adhesive layer, the conductive porous substrate is laminated on the catalyst layer on the user side. This process is omitted and the convenience is improved. Further, since an adhesive layer is interposed between the catalyst layer and the conductive porous substrate, the pressure for adhering the conductive porous substrate to the catalyst layer may be about 1 kgf / cm ² or less. For this reason, the pores in the conductive porous substrate are not crushed, and as a result, the gas diffusibility is not lowered.

  The above-mentioned adhesive layer can be composed of an adhesive or a pressure-sensitive adhesive, and the position where the adhesive layer is formed is preferably the central part on the catalyst layer. By forming an adhesive layer at the center of the catalyst layer in this way, when a liquid adhesive is used as the adhesive layer, there is no possibility that the adhesive protrudes from the outer peripheral edge of the catalyst layer and contacts the electrolyte membrane. . As a result, swelling of the electrolyte membrane caused by contact of the liquid adhesive with the electrolyte membrane can be prevented. As a result, dimensional deformation of the electrolyte membrane or the like, and peeling of the conductive porous substrate due to this dimensional deformation can be prevented. Can be prevented. In addition, when comprising an adhesive layer with an adhesive, an adhesive layer may be formed in a single adhesive, and an adhesive layer can also be formed with the form of a double-sided tape.

The adhesive layer preferably has an adhesion area of about 0.1 mm ² or more. By setting the adhesion area to about 0.1 mm ² or more, the conductive porous substrate can be sufficiently adhered so as not to peel off from the catalyst layer during transportation. Moreover, the fall of the electric power generation performance by having interposed the contact bonding layer can be prevented by making the contact area ratio of the contact bonding layer with respect to a catalyst layer into about 30% or less. The area of the adhesive layer was measured in the state before the conductive porous membrane and the catalyst layer were bonded, that is, the state when the adhesive layer was formed on the conductive porous substrate or the catalyst layer. is there. The adhesive layer may contain a conductive material in order to reliably prevent a decrease in power generation performance.

  The adhesive layer has a thickness of about 1 to 50 μm, preferably 5 to 10 μm. This layer thickness is measured with the conductive porous membrane and the catalyst layer adhered.

  The method for producing a membrane-electrode assembly according to the present invention includes a step of preparing a catalyst layer-electrolyte membrane laminate in which a catalyst layer is formed on both sides of an ion conductive polymer electrolyte membrane, and an adhesive layer. Adhering a conductive porous substrate onto the catalyst layer.

According to this manufacturing method, since the conductive porous substrate is bonded to the catalyst layer via the adhesive layer, the completed membrane-electrode assembly is electrically conductive porous to the catalyst layer-electrolyte membrane laminate. Since the base material is adhered, the step of laminating the conductive porous base material on the catalyst layer-electrolyte membrane laminate on the user side can be omitted, and convenience can be improved. In addition, since the conductive porous substrate is adhered onto the catalyst layer via the adhesive layer, the pressure required for this adhesion is about 1 kgf / cm ² or less. For this reason, the pores in the conductive porous substrate are not crushed, and as a result, the gas diffusibility is not lowered.

  The adhesive layer may be formed on the catalyst layer, or may be formed on a conductive porous substrate.

  Moreover, the above-mentioned adhesive layer can be formed of an adhesive or a pressure-sensitive adhesive, and the position where the adhesive layer is formed is preferably the central portion on each catalyst layer. By using the liquid adhesive as the adhesive layer by using the central portion on the catalyst layer in this way, there is no possibility that the adhesive protrudes from the outer peripheral edge of the catalyst layer and contacts the electrolyte membrane. Swelling of the electrolyte membrane caused by contact of the liquid adhesive with the electrolyte membrane can be prevented, and as a result, dimensional deformation of the electrolyte membrane and the like, and peeling of the conductive porous substrate due to this dimensional deformation can be prevented. be able to. In addition, as a specific example of the adhesive layer composed of the pressure-sensitive adhesive, a double-sided tape or the like can be given.

The adhesive layer preferably has an adhesion area of about 0.1 mm ² or more. By setting the adhesion area to about 0.1 mm ² or more, the conductive porous substrate can be sufficiently adhered so as not to peel off from the catalyst layer during transportation or the like, and the adhesion layer to the catalyst layer By reducing the adhesion area ratio to about 30% or less, it is possible to prevent a decrease in power generation performance due to the interposition of the adhesive layer. The area of the adhesive layer was measured in a state before the conductive porous membrane and the catalyst layer were bonded, that is, when the adhesive layer was formed on the conductive porous substrate or the catalyst layer. It is.

  The layer thickness of the adhesive layer is about 1-50 μm, preferably about 5-10 μm. This layer thickness is measured with the conductive porous membrane and the catalyst layer adhered.

  According to the present invention, a convenient membrane-electrode assembly can be provided without reducing gas diffusivity.

FIG. 1 is a side view showing an embodiment of a membrane-electrode assembly according to the present invention. FIG. 2 is a plan view of FIG. FIG. 3 is an explanatory view showing an embodiment of a method for producing a membrane-electrode assembly according to the present invention. FIG. 4 is a plan view showing a modification of the membrane-electrode assembly according to the present invention. FIG. 5 is a plan view showing a modification of the membrane-electrode assembly according to the present invention. FIG. 6 is a plan view showing a modification of the membrane-electrode assembly according to the present invention. FIG. 7 is a plan view showing a modification of the membrane-electrode assembly according to the present invention. FIG. 8 is a plan view showing a modification of the membrane-electrode assembly according to the present invention.

  Hereinafter, embodiments of a membrane-electrode assembly and a method for producing the same according to the present invention will be described with reference to the drawings.

[Membrane-electrode assembly]
As shown in FIG. 1, in the membrane-electrode assembly 1, catalyst layers 3 are formed on both surfaces of an ion conductive polymer electrolyte membrane 2, and a conductive porous substrate 4 is formed on each catalyst layer 3. It is bonded via an adhesive layer 5. In addition, what formed the catalyst layer 3 on both surfaces of the electrolyte membrane 2 is called catalyst layer-electrolyte membrane laminated body 10. FIG.

[Ion conductive polymer electrolyte membrane]
As shown in FIG. 2, the ion conductive polymer electrolyte membrane 2 has a rectangular shape in plan view and is not particularly limited, but the thickness is usually about 20 to 250 μm, preferably about 20 to It can be about 80 μm. The electrolyte membrane 2 is formed, for example, by applying a solution containing a hydrogen ion conductive polymer electrolyte on a substrate and drying it. Examples of the hydrogen ion conductive polymer electrolyte include a perfluorosulfonic acid-based fluorine ion exchange resin, more specifically, a perfluorocarbonsulfonic acid-based resin in which the C—H bond of a hydrocarbon ion-exchange membrane is substituted with fluorine. Examples include polymers (PFS polymers). By introducing a fluorine atom having high electronegativity, it is chemically very stable, the dissociation degree of the sulfonic acid group is high, and high ion conductivity can be realized. Specific examples of such a hydrogen ion conductive polymer electrolyte include “Nafion” (registered trademark) manufactured by DuPont, “Flemion” (registered trademark) manufactured by Asahi Glass Co., Ltd., and “Aciplex” manufactured by Asahi Kasei Corporation. ”(Registered trademark),“ Gore Select ”(registered trademark) manufactured by Gore, and the like. The concentration of the hydrogen ion conductive polymer electrolyte contained in the hydrogen ion conductive polymer electrolyte-containing solution is usually about 1 to 60% by weight, preferably about 5 to 30% by weight. In addition to the above-described hydrogen ion conductive polymer electrolyte membrane, a hydroxide ion conductive solid polymer electrolyte membrane and a liquid substance-impregnated membrane are also included. Examples of the hydroxide ion conductive electrolyte membrane include a hydrocarbon resin or a fluorine resin, and specific examples of the hydrocarbon resin include Aciplex (registered trademark) A201, 2111, 221 manufactured by Asahi Kasei Corporation. In addition, Neoceptor (registered trademark) AM-1, AHA manufactured by Tokuyama Corporation and the like, and examples of the fluororesin include Tosflex (registered trademark) IE-SF34 manufactured by Tosoh Corporation. Examples of the liquid substance-impregnated film include polybenzimidazole (PBI).

[Catalyst layer]
The catalyst layer 3 is formed slightly smaller than the electrolyte membrane 2 on both surfaces of the electrolyte membrane 2 and is not particularly limited, but the thickness thereof is about 1 to 200 μm, preferably about 1 to 100 μm. be able to. The catalyst layer 3 can be a known platinum-containing catalyst layer (cathode catalyst and anode catalyst). Specifically, it contains carbon particles carrying catalyst particles and a hydrogen ion conductive polymer electrolyte or a hydroxide ion conductive polymer electrolyte. As the hydrogen ion conductive polymer electrolyte or the hydroxide ion conductive polymer electrolyte, the same materials as those used for the electrolyte membrane 2 described above can be used.

  Examples of the catalyst particles include platinum and platinum compounds. Examples of the platinum compound include an alloy of platinum and at least one metal selected from the group consisting of ruthenium, palladium, nickel, molybdenum, iridium, iron and the like. In general, the catalyst particles contained in the cathode catalyst layer are platinum, and the catalyst particles contained in the anode catalyst layer are an alloy of the metal and platinum.

  The carbon particles are not limited as long as they have electrical conductivity, and known or commercially available carbon particles can be widely used. For example, carbon black, graphite, activated carbon, or the like can be used alone or in combination. Examples of carbon black include channel black, furnace black, ketjen black, acetylene black, and lamp black. The arithmetic average particle diameter of the carbon particles is usually about 5 nm to 200 nm, preferably about 20 to 80 nm. The average particle size of the carbon particles can be measured by, for example, a particle size distribution measuring device LA-920: manufactured by Horiba, Ltd.

[Conductive porous substrate]
The conductive porous substrate 4 is bonded to the catalyst layer 3 via the adhesive layer 5 with the same size as the catalyst layer 3 and is not particularly limited. The thickness can be 500 μm, preferably about 150 to 350 μm. The conductive porous substrate 4 is well-known and can use various conductive porous substrates constituting the fuel electrode and the air electrode, and efficiently supplies fuel gas and oxidant gas as fuel to the catalyst layer. Therefore, it consists of a porous conductive substrate. Examples of the porous conductive substrate include carbon paper and carbon cloth.

[Adhesive layer]
The adhesive layer 5 is interposed between the catalyst layer 3 and the conductive porous substrate 4 in order to adhere them, and can be formed of a pressure-sensitive adhesive or an adhesive. As shown in FIG. 2, the adhesion layer 5 is formed at substantially the center of the catalyst layer 3, and the adhesion area can be about 0.1 mm ² or more, preferably about 0.25 mm ² or more, Preferably, it can be about 25 mm ² or more. By making the adhesion area about 0.1 mm ² or more, the adhesion between the catalyst layer 3 and the conductive porous substrate 4 is sufficient, and the conductive porous substrate 4 is prevented from peeling off from the catalyst layer 3. can do. Moreover, the fall of the battery performance by the contact bonding layer 5 can be prevented by making the contact area ratio of the contact bonding layer 5 with respect to the catalyst layer 3 into about 30% or less. The adhesion area of the adhesive layer 5 is the state before the conductive porous film 4 and the catalyst layer 3 are bonded, that is, immediately after the adhesive layer 5 is formed on the catalyst layer 3 or the conductive porous substrate 4. It was measured in the state of. The layer thickness of the adhesive layer 5 is about 1 to 50 μm, preferably about 5 to 10 μm. The thickness of the adhesive layer 5 is measured in a state where the conductive porous substrate 4 and the catalyst layer 3 are adhered.

  As a material for the adhesive layer 5, when the adhesive layer 5 is formed of an adhesive, for example, an acrylic, rubber-based, or silicone-based adhesive can be used. Specifically, acrylic ester copolymers, methacrylic ester copolymers, natural rubber (NR), synthetic natural rubber (IR), styrene-butadiene rubber (SBR), polyisobutylene (PIB), butyl rubber (IIR) , Silicone rubber, and the like. These can be used alone or in combination of two or more. When the adhesive layer 5 is formed with an adhesive, for example, vinyl acetate resin, polyvinyl alcohol, polyvinyl acetal, ethylene / vinyl acetate resin, vinyl chloride resin, acrylic resin, polyamide, cellulose Thermoplastic resin such as α-olefin resin, urea resin, melamine resin, phenol resin, resorcinol resin, epoxy resin, polyester resin, urethane resin, polyimide, polybenzimidazole Thermosetting resin systems such as chloroprene rubber system, nitrile rubber system, styrene butadiene rubber system, polysulfide system, butyl rubber system, silicone system, acrylic rubber system, urethane rubber system, etc. Ester acrylates, ether acrylates Rate, urethane acrylates, epoxy acrylates, amino resin acrylates, mention may be made of a photocurable resin such as an acrylic resin acrylates, unsaturated polyesters. In addition, other materials similar to the electrolyte membrane 2 such as a perfluorocarbon sulfonic acid-based fluorine ion exchange resin can be mentioned. Specifically, “Nafion” (registered trademark) manufactured by DuPont, Asahi Glass Co., Ltd. “Flemion” (registered trademark) manufactured by Asahi Kasei Co., Ltd., “Aciplex” (registered trademark) manufactured by Asahi Kasei Co., Ltd., “Gore Select” (registered trademark) manufactured by Gore, Inc., and the like. Similarly, this adhesive can be used alone or in combination of two or more. The adhesive may contain an additive such as a conductive material or an ultraviolet absorber. Moreover, when using an adhesive as the contact bonding layer 5, you may interpose an adhesive between the catalyst layer 3 and the electroconductive porous base material 4 alone, and with the catalyst layer 3 as a form of a double-sided tape, It may be interposed between the conductive porous substrate 4.

[Production method]
Next, the manufacturing method of the membrane-electrode assembly described above will be described with reference to FIG.

  As shown in FIG. 3, first, the electrolyte membrane 2 is prepared, and the catalyst layer 3 is formed on both surfaces of the electrolyte membrane 3. Various methods can be adopted as a method for forming the catalyst layer 3. In this embodiment, a case where a transfer method is adopted will be described. First, an electrolyte membrane 2 made of the above-described material is prepared, and a catalyst layer forming transfer sheet 6 is placed on both surfaces of the electrolyte membrane 2 (FIG. 3A). The catalyst layer forming transfer sheet 6 is one in which the catalyst layer 3 to be transferred to the electrolyte membrane 2 is formed on the transfer substrate 61.

  Here, a method for producing the transfer sheet 6 for forming a catalyst layer will be described. First, the carbon particles carrying the catalyst particles and the hydrogen ion conductive polymer electrolyte are mixed and dispersed in a suitable solvent to prepare a catalyst paste. Then, the catalyst layer 3 is formed by coating and drying the catalyst paste on the transfer substrate 61 so that the formed catalyst layer 3 has a desired thickness. If necessary, a catalyst paste is applied onto the transfer substrate 61 via a release layer. Examples of the coating method for each catalyst paste include known coating methods such as screen printing, spray coating, die coating, and knife coating. After applying the catalyst paste, the catalyst layer 3 is formed on the transfer substrate 61 by drying at a predetermined temperature and time. A drying temperature is about 40-100 degreeC normally, Preferably it is about 60-80 degreeC. Although depending on the drying temperature, the drying time is usually about 5 minutes to 2 hours, preferably about 10 minutes to 1 hour.

  Examples of the solvent used in each catalyst paste include various alcohols, various ethers, various dialkyl sulfoxides, water, or a mixture thereof. Of these, alcohols are preferable. Examples of alcohols include monohydric alcohols having 1 to 4 carbon atoms such as methanol, ethanol, n-propanol, isopropanol, 1-butanol, 2-butanol, tert-butanol, and various polyhydric alcohols. .

  As the transfer substrate 61, for example, polyimide, polyethylene terephthalate, polyparvanic acid aramid, polyamide (nylon), polysulfone, polyethersulfone, polyphenylene sulfide, polyether ether ketone, polyetherimide, polyarylate, polyethylene naphthalate. And the like. Further, heat resistance of ethylene tetrafluoroethylene copolymer (ETFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroperfluoroalkyl vinyl ether copolymer (PFA), polytetrafluoroethylene (PTFE), etc. Fluorine resin can also be used. Further, the transfer substrate 81 may be coated paper such as art paper, coated paper, and lightweight coated paper, non-coated paper such as notebook paper and copy paper, in addition to the polymer film. The thickness of the transfer substrate 61 is usually about 6 to 100 μm, preferably about 10 to 30 μm, from the viewpoints of handleability and economy. Therefore, as the transfer substrate 61, a polymer film that is inexpensive and easily available is preferable, and polyethylene terephthalate or the like is more preferable.

  Returning to FIG. 3, the description of the method for producing the polymer electrolyte fuel cell will be continued. The transfer sheet 6 for forming a catalyst layer prepared as described above is arranged so that the catalyst layer 3 faces the electrolyte membrane 2 (FIG. 3A), and a heat press is applied from the back side of the transfer sheet 6 to apply the catalyst layer. 3 is transferred to the electrolyte membrane 2, and the transfer substrate 61 of the transfer sheet 6 is peeled off (FIG. 3B). In consideration of workability, it is preferable to simultaneously laminate the catalyst layer 3 on both surfaces of the electrolyte membrane 2, but the catalyst layer 3 can also be formed on each side. The pressure level of the heating press is usually about 0.5 to 20 MPa, preferably about 1 to 10 MPa in order to avoid transfer failure. Further, it is preferable to heat the pressing surface during this pressing operation in order to avoid transfer failure. The heating temperature is usually 200 ° C. or lower, preferably 150 ° C. or lower, in order to avoid damage or deformation of the electrolyte membrane 2. Thus, the catalyst layer-electrolyte film | membrane laminated body 10 is formed by forming the catalyst layer 3 on both surfaces of the electrolyte membrane 2 (FIG.3 (b)).

  Subsequently, the adhesive layer 5 is formed at the center of the catalyst layer 3 (FIG. 3C). As a method for forming the adhesive layer 5, when the adhesive layer 5 is formed of an adhesive, the adhesive layer 5 is formed by a known coating method such as screen printing, spray coating, die coating, knife coating, dispenser, or inkjet. And so on. Similarly, when the adhesive layer 5 is formed of an adhesive, the adhesive layer 5 is formed on the catalyst layer 3 by a known coating method such as screen printing, spray coating, die coating, knife coating, dispenser, or inkjet. Form. Moreover, when using an adhesive in the form of a double-sided tape, a double-sided tape is cut | disconnected to a predetermined magnitude | size, and it affixes on the catalyst layer 3. FIG.

Then, the conductive porous substrate 4 made of the above-described material is bonded onto the catalyst layer 3 via the adhesive layer 5. Since the pressure required for this adhesion may be about 1 kgf / cm ² or less, there is no need to use a press or the like. For example, the conductive porous substrate 4 can be made conductive by lightly pushing the conductive porous substrate 4 against the catalyst layer 3 by hand. The porous substrate 4 and the catalyst layer 3 are bonded. Thus, the membrane-electrode assembly 1 is completed (FIG. 3D).

  As described above, according to the membrane-electrode assembly 1 of the present embodiment, since the conductive porous substrate 4 is adhered to the catalyst layer 3 via the adhesive layer 5, it is electrically conductive on the catalyst layer 3 on the user side. The step of laminating the porous porous substrate 4 is not necessary, and the convenience is improved. In addition, since the conductive porous substrate 4 can be adhered on the catalyst layer 3 without applying a large pressure to the conductive porous substrate 4, fine pores in the conductive porous substrate 4 are crushed. This can be prevented, and the gas diffusivity does not decrease.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to these, A various change is possible unless it deviates from the meaning of this invention.

  For example, in the above embodiment, the transfer method has been described as a method for forming the catalyst layer 3 on both surfaces of the electrolyte membrane 2, but other methods such as screen printing, spray coating, die coating, knife coating, dispenser, and inkjet are also used. The catalyst layer 3 can be formed on both surfaces of the electrolyte membrane 2 by a known coating method such as.

  In the above embodiment, the conductive porous substrate 4 is adhered to the catalyst layer 3 after the adhesive layer 5 is formed on the catalyst layer 3, but the adhesive layer 5 is adhered to the conductive porous substrate 4. After the formation, the conductive porous substrate 4 may be adhered to the catalyst layer 3 via the adhesive layer 5.

  Moreover, in the said embodiment, although the contact bonding layer 5 is formed in the center part of the catalyst layer 3, the position and formation pattern in which this contact bonding layer 5 is formed are not specifically limited, For example, in four corners The adhesive layer 5 is formed (FIG. 4), formed in a cross shape (FIG. 5), formed in a linear shape extending in the center of the catalyst layer 3 (FIG. 6), or along the outer peripheral edge of the catalyst layer 3 (FIG. 7) or a sea island shape on the catalyst layer 3 (FIG. 8). In addition, the width | variety of each contact bonding layer 5 can be changed suitably.

  Moreover, in the said embodiment, although the catalyst layer 3 and the electroconductive porous base material 4 became a little smaller shape than the electrolyte membrane 2, it is not limited to this in particular, These are all the same magnitude | sizes. It can also be. Further, the electrolyte membrane 2, the catalyst layer 3, and the conductive porous substrate 4 are all formed in a rectangular shape in plan view, but can take various shapes, for example, all can be circular in plan view. .

  The present invention will be described more specifically with reference to examples and comparative examples. The present invention is not limited to the following examples.

  As the electrolyte membrane 2, Nafion 115 (manufactured by DuPont) having a thickness of 125 μm cut to a size of 50 mm × 50 mm was used.

A catalyst layer 3 of 22.3 mm × 22.3 mm and a layer thickness of 20 μm was formed on both surfaces of the electrolyte membrane 2 by a transfer method. Specifically, 2 g of platinum catalyst supported carbon (platinum supported amount: 45.7 wt%, manufactured by Tanaka Kikinzoku Co., Ltd., TEC10E50E), 10 g of 1-butanol, 10 g of 2-butanol, and fluororesin (5 wt% Nafion Binder, manufactured by DuPont) ) and 20g and water 6g added, these catalyst-forming paste prepared by mixing and stirring at disperser, a polyester film as the weight of platinum catalyst after layer drying is 0.4 mg / cm ² (manufactured by Toray Industries, Inc. X44, 25 μm) to prepare a catalyst layer transfer film. Then, this catalyst layer transfer film is placed on both surfaces of the electrolyte membrane 2 so that the catalyst layer 3 faces the electrolyte membrane 2 side, and is hot pressed under conditions of 135 ° C., 5.0 MPa, 150 seconds. The catalyst layer 3 was formed on both surfaces of the electrolyte membrane 2.

  In Examples 1 to 8, the adhesive layer 5 is formed on the catalyst layer 3 of the catalyst layer-electrolyte membrane laminate 10 formed as described above under the conditions shown in Table 1 below. The conductive porous substrate 4 was bonded onto the catalyst layer 3 via In Examples 1, 3, 6, and 7, a pressure-sensitive adhesive (double-sided tape) was used as the adhesive layer 5, and in Examples 2, 4, 5, and 8, an adhesive was used as the adhesive layer 5. In Comparative Example 1, the conductive porous substrate 4 is simply laminated on the catalyst layer 3 and the adhesive layer 5 is not formed. The conductive porous substrate 4 used in Examples 1 to 8 and Comparative Example 1 is 22.3 mm × 22.3 mm carbon paper (manufactured by Toray Industries, Inc., TGP-H-090, thickness 280 μm). is there.

  The pressure-sensitive adhesive used in Examples 1, 3, 6, and 7 is a general industrial double-sided tape (Teraoka Seisakusho, 751B, acrylic pressure-sensitive adhesive, thickness 160 μm). In Examples 2, 4, 5, and 8, Nafion binder manufactured by DuPont using a fluororesin as a binder was used for adhesion. In addition, the “central part” at the position in Table 1 means that the adhesive layer 5 is formed at the central part of the catalyst layer 3, and the “four corners” means the adhesive layer 5 at the four corners of the catalyst layer 3, respectively. It means that it was formed. Further, the adhesion area is measured in a state before the conductive porous substrate 4 and the catalyst layer 3 are bonded, that is, in a state immediately after the adhesion layer 5 is formed on the catalyst layer 3. The rate indicates the ratio of the adhesive area of the adhesive layer 5 to the catalyst layer 3. When the adhesive layers 5 are formed at the four corners, the adhesive area represents the total area of the four adhesive layers 5.

  For the membrane-electrode assemblies according to Examples 1 to 8 and Comparative Example 1 formed as described above, the adhesive force and the power generation performance were evaluated. As an evaluation of the adhesive strength, the catalyst layer 3 and the conductive porous substrate 4 were obtained as a result of shaking for 3 minutes at a rotational speed of 200 r / min using a shaker (TAITEC, NR-3). The case where the bonded state was maintained was “◯”, and the case where the conductive porous substrate 4 was peeled off from the catalyst layer 3 was “x”. The power generation performance was evaluated by measuring current and voltage using a fuel cell manufactured by Electrochem Co., Ltd. at a cell temperature of 70 ° C., a methanol concentration of 1 mol, an anode-side methanol flow rate of 1 ml / min, and a cathode-side air flow rate of 150 ml / min.

  As can be seen from Table 1, when the double-sided tape is used for the adhesive layer 5, the adhesive area of the adhesive layer 5 is 0.3 mm × 0.3 mm or more, and when Nafion is used for the adhesive layer 5, the adhesive layer 5 is bonded. It was found that the conductive porous substrate 4 was sufficiently adhered to the catalyst layer 3 when the area was 0.5 mm × 0.5 mm or more. It was also found that if the adhesion area is at least 12 mm × 12 mm or less, the power generation performance is almost unchanged whether or not the adhesive layer 5 is provided.

DESCRIPTION OF SYMBOLS 1 Membrane-electrode assembly 2 Ion conductive polymer electrolyte membrane 3 Catalyst layer 4 Conductive porous substrate 5 Adhesive layer 10 Catalyst layer-electrolyte membrane laminate

Claims (11)

An ion conductive polymer electrolyte membrane;
A catalyst layer formed on both surfaces of the ion conductive polymer electrolyte membrane;
An adhesive layer formed on each of the catalyst layers;
A conductive porous substrate pasted on the catalyst layer via the adhesive layer;
With
The adhesive layer is a membrane-electrode assembly formed of a single adhesive or a double-sided tape having an adhesive . An ion conductive polymer electrolyte membrane;
A catalyst layer formed on both surfaces of the ion conductive polymer electrolyte membrane;
An adhesive layer formed on each of the catalyst layers;
A conductive porous substrate pasted on the catalyst layer via the adhesive layer;
With
The adhesive layer is a membrane-electrode assembly having an adhesion area ratio with respect to the catalyst layer of 0.03% to 0.8%.   The membrane-electrode assembly according to claim 2, wherein the adhesive layer is formed of an adhesive or a pressure-sensitive adhesive. An ion conductive polymer electrolyte membrane;
A catalyst layer formed on both surfaces of the ion conductive polymer electrolyte membrane;
An adhesive layer formed on each of the catalyst layers;
A conductive porous substrate pasted on the catalyst layer via the adhesive layer;
With
The adhesive layer is formed of an adhesive or a pressure-sensitive adhesive, and an adhesion area ratio with respect to the catalyst layer is 0.03% to 30%,
The adhesive is
Vinyl acetate resin, polyvinyl alcohol, polyvinyl acetal, ethylene / vinyl acetate resin, vinyl chloride resin, acrylic resin, polyamide, cellulose, α-olefin resin, urea resin, melamine resin, phenol Resin, Resorcinol resin, Epoxy resin, Polyester resin, Urethane resin, Polyimide, Polybenzimidazole, Chloroprene rubber, Nitrile rubber, Styrene butadiene rubber, Polysulfide, Butyl rubber, Silicone, Acrylic Group consisting of rubber, urethane rubber, ester acrylate, ether acrylate, urethane acrylate, epoxy acrylate, amino resin acrylate, acrylic resin acrylate, and unsaturated polyester Ri is at least one selected, membrane - electrode assembly. The membrane-electrode assembly according to any one of claims 1 to 4, wherein the adhesive layer is formed in a portion excluding an outer peripheral edge on the catalyst layer. The membrane-electrode assembly according to any one of claims 2 to 5, wherein the adhesive layer contains a conductive material. A step of preparing a catalyst layer-electrolyte membrane laminate in which a catalyst layer is formed on both surfaces of an ion conductive polymer electrolyte membrane;
Forming an adhesive layer on the catalyst layer;
Adhering a conductive porous substrate onto the catalyst layer via the adhesive layer;
The manufacturing method of the membrane-electrode assembly containing this. The method for producing a membrane-electrode assembly according to claim 7, wherein the conductive porous substrate is bonded onto the catalyst layer at a pressure of 1 kgf / cm ² or less.   The method for producing a membrane-electrode assembly according to claim 7 or 8, wherein the adhesive layer is formed of an adhesive or a pressure-sensitive adhesive. The membrane-electrode assembly according to any one of claims 7 to 9, wherein the adhesive layer after bonding of the conductive porous substrate is formed in a portion excluding the outer peripheral edge on each catalyst layer. Method. An ion conductive polymer electrolyte membrane;
A catalyst layer formed on both surfaces of the ion conductive polymer electrolyte membrane;
An adhesive layer formed on each of the catalyst layers;
A catalyst layer-electrolyte membrane laminate comprising: