JP5195286B2 - Manufacturing method of membrane electrode assembly for polymer electrolyte fuel cell - Google Patents

Description

  The present invention relates to a method for producing a membrane / electrode assembly for a polymer electrolyte fuel cell capable of obtaining a high output voltage over a wide range of current densities.

  A fuel cell using hydrogen and oxygen is attracting attention as a power generation system that has almost no adverse environmental impact because its reaction product is essentially only water. In particular, in recent years, polymer electrolyte fuel cells that use proton-conductive ion exchange membranes as electrolytes have low operating temperatures, high output densities, and can be miniaturized. Promising.

  The polymer electrolyte fuel cell is characterized by a low operating temperature (50 to 120 ° C.) as described above, but on the other hand, there is a problem that exhaust heat is difficult to effectively use for auxiliary power. . In order to compensate for this, the polymer electrolyte fuel cell is required to have high hydrogen and oxygen utilization, that is, high energy efficiency and high power density.

  In order for a polymer electrolyte fuel cell to satisfy the above requirements, it is particularly composed of gas diffusion electrodes (usually a catalyst layer containing a catalyst and a gas diffusion layer made of carbon paper, carbon cloth, etc.) among the elements constituting the battery. And membrane electrode assemblies in which the electrodes are formed on both surfaces of the ion exchange membrane are important. Conventionally, the catalyst layer of a gas diffusion electrode is made of a catalyst powder that promotes an electrode reaction, and a fluorine-containing ion exchange resin that increases conductivity and prevents clogging (flooding) of a porous body due to condensation of water vapor. It is made using a viscous mixture dissolved or dispersed in an alcohol solvent such as. The viscous mixture is applied directly to the surface of the ion exchange membrane, or a layer obtained by applying the viscous mixture to another sheet-like substrate is transferred or bonded to the surface of the ion exchange membrane. However, the gas diffusion electrode thus obtained is not necessarily satisfied with respect to flooding resistance, gas diffusibility, conductivity under low humidification, adhesion at the electrode interface, and dry and wet repetition resistance. Had.

  On the other hand, for example, in order to enhance drainage and prevent flooding, a method of providing an intermediate layer composed of conductive fibrous carbon or hydrophobic fibrous carbon between the catalyst layer and the gas diffusion layer ( Patent Document 1), a method of providing a microporous layer between a catalyst layer and a gas diffusion layer using carbon having different water repellency (see Patent Document 2), and ensuring a wide range of power generation characteristics under low humidification In order to improve the power generation characteristics in the current density region, a method of providing an intermediate layer having a water retention function between the catalyst layer and the gas diffusion layer (see Patent Document 3) has been studied. However, although these methods improve the power generation characteristics, there is a problem that the adhesion at the electrode interface and the dry and wet repeated resistance are not sufficient.

On the other hand, from the viewpoint of improving adhesion, a carbon intermediate layer ink containing carbon powder, a fluororesin, and a dispersion medium is applied on the catalyst layer, and the gas diffusion layer is formed on the ink layer while the ink layer is wet. However, since the base material to be applied is a catalyst layer or a catalyst layer formed on the membrane, the amount of the fluororesin and the dispersion medium that has oozed out is large. There is a problem that the gas diffusibility of the resulting catalyst layer is lowered, and since the dispersion medium is soaked quickly and easily dried, there is a problem that the adhesion to the gas diffusion layer is not sufficiently stable.

  In addition, a water repellent layer made of carbon and a water repellent material is provided on the gas diffusion layer, a hydrophilic layer made of carbon and an ion exchange resin material is further provided thereon, and the hydrophilic layer side is heated and pressed with the catalyst layer. A method for improving adhesion (see Patent Documents 5 and 6) has also been studied. However, when an ink made of carbon and an ion exchange resin material is applied onto a water-repellent layer in order to form a hydrophilic layer, the catalyst layer and the hydrophilic layer are formed. Although there are many ion exchange resin materials that are thought to contribute significantly to the adhesion at the interface with the layer on the side of the water-repellent layer opposite to the interface to be bonded in the subsequent process, the adhesion is improved compared to the conventional one. There was a problem that was not enough.

JP 2005-190701 A JP 2006-004879 A JP 2006-244789 A JP 2003-282079 A JP 2004-221056 A JP 2004-214173 A

  The present invention provides a membrane electrode for a polymer electrolyte fuel cell that has high durability and high output voltage in a wide range of current densities, and has high durability even when used in an environment where drying and wetting are repeated. Provided is a method capable of manufacturing a joined body.

The method for producing a membrane / electrode assembly for a polymer electrolyte fuel cell according to the present invention comprises a first electrode having a first catalyst layer and a first gas diffusion layer, a second catalyst layer and a second gas. A second electrode having a diffusion layer; a solid polymer electrolyte membrane disposed between the first catalyst layer and the second catalyst layer; the first catalyst layer and the first gas; A method for producing a membrane / electrode assembly for a polymer electrolyte fuel cell comprising a first carbon layer containing carbon and an ion exchange resin between the diffusion layers, comprising the following steps (a) to (c): ), (P), (q1).
(A) A step of forming a first carbon layer coating liquid layer by applying a carbon layer coating liquid containing carbon and an ion exchange resin on a base film.
(B) After covering the first gas diffusion layer on the first carbon layer coating liquid layer formed in step (a), drying the first carbon layer coating liquid layer. Forming the first carbon layer.
(C) The process of peeling a base film from the laminated body which has the said 1st carbon layer and said 1st gas diffusion layer formed at the process (b), and obtaining a laminated body (A).
(P) A step of forming the first catalyst layer on one surface of the solid polymer electrolyte membrane.
(Q1) The first carbon layer of the laminate (A) obtained in step (c) and the first catalyst formed on one surface of the solid polymer electrolyte membrane in step (p) A process of heat bonding so as to contact the layer.

  The ion exchange resin contained in the first carbon layer is a fluorine-containing ion exchange resin, and the carbon of the first carbon layer and the fluorine-containing ion exchange resin are in a mass ratio of 1: 0.1 to 1: 5. It is preferable that

  It is preferable that the thickness of the first carbon layer is 1 to 60 μm.

A second carbon layer containing carbon and an ion exchange resin is provided between the second catalyst layer of the second electrode and the second gas diffusion layer, and the following steps (a ′) to It is preferable to further have (c ′), (p ′), and (q′1).
(A ′) A step of forming a second carbon layer coating liquid layer by applying a carbon layer coating liquid containing carbon and an ion exchange resin on the base film.
(B ′) After covering the second gas diffusion layer on the second carbon layer coating liquid layer formed in the step (a ′), the second carbon layer coating liquid layer is applied. Drying to form the second carbon layer.
(C ′) A step of obtaining a laminate (A ′) by peeling off the base film from the laminate having the second carbon layer and the second gas diffusion layer formed in the step (b ′).
(P ′) A step of forming the second catalyst layer on one surface of the solid polymer electrolyte membrane.
(Q′1) formed on one surface of the solid polymer electrolyte membrane in the step (p ′) and the second carbon layer of the laminate (A ′) obtained in the step (c ′). Heating and joining the second catalyst layer in contact with the second catalyst layer;

  The ion exchange resin contained in the second carbon layer is a fluorinated ion exchange resin, and the carbon of the second carbon layer and the fluorinated ion exchange resin are in a mass ratio of 1: 0.1 to 1: 5 is preferable.

  The thickness of the second carbon layer is preferably 1 to 60 μm.

Another method for producing a membrane electrode assembly for a polymer electrolyte fuel cell according to the present invention includes a first electrode having a first catalyst layer and a first gas diffusion layer, a second catalyst layer, A second electrode having a second gas diffusion layer; a solid polymer electrolyte membrane disposed between the first catalyst layer and the second catalyst layer; the first catalyst layer; Method of manufacturing membrane electrode assembly for polymer electrolyte fuel cell, comprising first carbon layer A and first carbon layer B containing carbon and ion exchange resin between first gas diffusion layer And it has the following process (g)-(j), (p), (q4), It is characterized by the above-mentioned.
(G) The process of forming the 1st carbon layer A by apply | coating the coating liquid for carbon layer A containing carbon and an ion exchange resin on a base film, and drying.
(H) On the first carbon layer A formed in step (g), a carbon layer B coating solution containing carbon and an ion exchange resin is applied to form a first carbon layer B coating solution layer. Forming.
(I) After covering the first gas diffusion layer on the first carbon layer B coating liquid layer formed in the step (h), the first carbon layer B coating liquid layer is applied. A step of forming the first carbon layer B by drying.
(J) The substrate film is peeled off from the laminate having the first carbon layer A, the first carbon layer B, and the first gas diffusion layer formed in the step (i), and the laminate (D) Obtaining.
(P) A step of forming the first catalyst layer on one surface of the solid polymer electrolyte membrane.
(Q4) The first carbon layer A of the laminate (D) obtained in step (j) and the first carbon layer formed on one surface of the solid polymer electrolyte membrane in step (p) A process of heat-bonding so as to contact the catalyst layer.

  It is preferable that the thickness of the first carbon layer A is 0.5 to 20 μm.

A membrane for a solid polymer fuel cell having a second carbon layer A and a second carbon layer B containing carbon and an ion exchange resin between the second catalyst layer and the second gas diffusion layer It is a manufacturing method of an electrode assembly, and preferably further includes the following steps (g ′) to (j ′), (p ′), and (q4 ′).
(G ′) A step of coating the base film with a coating solution for carbon layer A containing carbon and an ion exchange resin, and drying to form a second carbon layer A.
(H ′) On the second carbon layer A formed in the step (g ′), a carbon layer B coating solution containing carbon and an ion exchange resin is applied to apply the second carbon layer B. Forming a liquid layer;
(I ′) After covering the second gas diffusion layer on the second carbon layer B coating liquid layer formed in the step (h ′), the second carbon layer B coating liquid layer The process of drying 2nd and forming the 2nd carbon layer B.
(J ′) The substrate is peeled off from the laminate having the second carbon layer A, the second carbon layer B, and the second gas diffusion layer formed in step (i ′), and the laminate A step of obtaining (D ′).
(P ′) A step of forming the second catalyst layer on one surface of the solid polymer electrolyte membrane.
(Q4 ′) formed on one surface of the solid polymer electrolyte membrane in the second carbon layer A of the laminate (D ′) obtained in the step (j ′) and in the step (p ′). Heating and joining the second catalyst layer in contact with the second catalyst layer;

  The thickness of the second carbon layer A is preferably 0.5 to 20 μm.

  The first electrode is preferably a cathode.

  The carbon is preferably a carbon nanofiber having a fiber diameter of 1 to 1000 nm and a fiber length of 1000 μm or less.

  According to the method for producing a membrane electrode assembly for a polymer electrolyte fuel cell of the present invention, it is used in an environment where durability and high output voltage are obtained in a wide range of current densities, and drying and wetting are repeated. However, a membrane electrode assembly for a polymer electrolyte fuel cell having high durability can be produced.

  In the present specification, a compound represented by the formula (1) is referred to as a compound (1). The same applies to compounds represented by other formulas.

[First Embodiment]
FIG. 1 is a cross-sectional view showing an example of a membrane electrode assembly for a polymer electrolyte fuel cell (hereinafter also referred to as a membrane electrode assembly). The membrane electrode assembly 100 includes a first electrode 120 having a first catalyst layer 12, a first carbon layer 14, and a first gas diffusion layer 16, a second catalyst layer 22, and a second carbon layer 24. And a solid polymer electrolyte between the second electrode 130 having the second gas diffusion layer 26, and the first catalyst layer 12 of the first electrode 120 and the second catalyst layer 22 of the second electrode 130. A film 40 is provided.

  The first electrode 120 may be an anode or a cathode, but the first electrode 120 is preferably a cathode. The second electrode 130 is a cathode when the first electrode 120 is an anode, and is an anode when the first electrode 120 is a cathode.

(Solid polymer electrolyte membrane)
The solid polymer electrolyte membrane 40 is made of an ion exchange resin membrane.
As the ion exchange resin of the solid polymer electrolyte membrane 40, a fluorine-containing ion exchange resin is preferably used from the viewpoint of durability, but a non-fluorine-containing ion exchange resin can also be used.

  Non-fluorinated ion exchange resins include polymers having sulfonic acid groups and no fluorine atoms. Examples of the polymer include a polymer having an aromatic ring and a structure in which a sulfonic acid group is introduced into the aromatic ring, and an ion exchange capacity of 0.8 to 3.0 meq / g dry resin. There are certain polymers. Specifically, sulfonated polyarylene, sulfonated polybenzoxazole, sulfonated polybenzothiazole, sulfonated polybenzimidazole, sulfonated polysulfone, sulfonated polyethersulfone, sulfonated polyetherethersulfone, sulfonated polyphenylenesulfone, Examples thereof include sulfonated polyphenylene oxide, sulfonated polyphenylene sulfoxide, sulfonated polyphenylene sulfide, sulfonated polyphenylene sulfide sulfone, sulfonated polyether ketone, sulfonated polyether ether ketone, sulfonated polyether ketone ketone, and sulfonated polyimide.

  The ion exchange capacity of the non-fluorine ion exchange resin is preferably 1.6 to 3.5 meq / g dry resin, and 1.8 to 2.5 meq / g dry resin from the viewpoint of conductivity and gas diffusibility. Is more preferable.

  Examples of the fluorine-containing ion exchange resin include perfluorocarbon polymers having sulfonic acid groups (hereinafter referred to as sulfonic acid-type perfluorocarbon polymers).

  As the sulfonic acid type perfluorocarbon polymer, polymer (A) or polymer (B) is preferable, and polymer (B) is particularly preferable.

Polymer (A):
The polymer (A) is a copolymer having units based on tetrafluoroethylene (hereinafter referred to as TFE) and units (1).

  However, X is a fluorine atom or a trifluoromethyl group, m is an integer of 0 to 3, n is an integer of 1 to 12, and p is 0 or 1.

Polymer (A), after obtaining the precursor polymer having -SO 2 _F groups by polymerizing a mixture of TFE and the compound (2), to convert the -SO 2 _F groups in the precursor polymer to sulfonic acid groups Can be obtained. Conversion of the —SO ₂ F group into a sulfonic acid group is performed by hydrolysis and acidification treatment.
_{CF 2 = CF (OCF 2 CFX} ) m -O p - (CF 2) n -SO 2 F ··· (2).
However, X is a fluorine atom or a trifluoromethyl group, m is an integer of 0 to 3, n is an integer of 1 to 12, and p is 0 or 1.
As the compound (2), compounds (21) to (23) are preferable.
CF ₂ = CFO (CF ₂ ) _n1 SO ₂ F (21),
CF ₂ = CFOCF ₂ CF (CF ₃ ) O (CF ₂ ) _{n 2} SO ₂ F (22),
_{CF 2 = CF (OCF 2 CF} (CF 3)) m3 O (CF 2) n3 SO 2 F ··· (23).
However, n1, n2, and n3 are integers of 1 to 8, and m3 is an integer of 1 to 3.

Polymer (B):
The polymer (B) is a copolymer having units based on TFE and units (3).

However, Q ¹ is a perfluoroalkylene group which may have an etheric oxygen atom, and Q ² is a perfluoroalkylene group which may have a single bond or an etheric oxygen atom. Y is a fluorine atom or a monovalent perfluoro organic group.
The single bond means that the carbon atom of CY and the sulfur atom of SO ₃ H are directly bonded.
An organic group means a group containing one or more carbon atoms.
When the perfluoroalkylene group of Q ¹ and Q ² has an etheric oxygen atom, the oxygen atom may be 1 or 2 or more. The oxygen atom may be inserted between the carbon atom-carbon atom bonds of the perfluoroalkylene group or may be inserted at the carbon atom bond terminal.
The perfluoroalkylene group preferably has 1 to 6 carbon atoms, and may be linear or branched.

  As the unit (3), the unit (4) is preferable, and the unit (41) or the unit (42) is more preferable.

However, R ^F11 is a straight-chain perfluoroalkylene group having 1 to 6 carbon atoms which may have a single bond or an etheric oxygen atom, and R ^F12 is a straight chain having 1 to 6 carbon atoms. It is a chain perfluoroalkylene group.
The polymer (B) may further have repeating units based on other monomers (hereinafter referred to as other units).

  The other unit is preferably a repeating unit based on a perfluoromonomer from the viewpoint of mechanical strength and chemical durability, and the above-mentioned functional group-containing units (1) and units (5) are preferable. As the unit (5), the unit (51) or the unit (52) is more preferable. However, t is an integer of 0-5 and q is an integer of 1-12.

The EW of the polymer (B) is preferably 400 to 900 g dry resin / equivalent (hereinafter referred to as g / equivalent), and more preferably 500 to 800 g / equivalent.
The mass average molecular weight of the polymer (B) is preferably 1 × 10 ⁴ to 1 × 10 ^{7 and} more preferably 5 × 10 ^{4 to} 5 × 10 ⁶ .

The mass average molecular weight of the polymer (B) can be evaluated by measuring the TQ value. The TQ value (unit: ° C.) is an index of the molecular weight of the polymer, and the extrusion amount when the polymer is melt-extruded under the condition of the extrusion pressure of 2.94 MPa using a nozzle having a length of 1 mm and an inner diameter of 1 mm is 100 mm. ^The temperature is ³ / sec. For example, a polymer having a TQ value of 200 to 300 ° C. corresponds to a mass average molecular weight of 1 × 10 ⁵ to 1 × 10 ⁶ although the composition of repeating units constituting the polymer differs.

  The ion exchange capacity of the fluorine-containing ion exchange resin is preferably 1.1 to 1.8 meq / g dry resin, and preferably 1.25 to 1.65 meq / g dry resin from the viewpoint of conductivity and gas diffusibility. Is more preferable.

  The solid polymer electrolyte membrane 40 preferably contains an inhibitor that suppresses the generation of peroxide. When the polymer electrolyte fuel cell is operated for a long time, the solid polymer electrolyte membrane 40 is deteriorated due to generation of peroxide, and the output voltage of the polymer electrolyte fuel cell is lowered. The inhibitor is preferably contained in the electrolyte membrane coating liquid described below.

  The thickness of the solid polymer electrolyte membrane 40 is preferably 50 μm or less, more preferably 3 to 40 μm, and particularly preferably 5 to 30 μm. When the thickness of the solid polymer electrolyte membrane 40 is 50 μm or less, the solid polymer electrolyte membrane 40 is unlikely to be in a dry state, and a decrease in power generation characteristics of the solid polymer fuel cell can be suppressed. If the thickness of the solid polymer electrolyte membrane 40 is 3 μm or more, a short circuit is unlikely to occur.

As a method for producing the solid polymer electrolyte membrane 40, when the ion exchange resin is the polymer (A) or (B), the following method (x) or method (y) may be mentioned, and the thickness accuracy and productivity can be improved. From the viewpoint, the method (y) is preferable.
(X) A method of converting a —SO ₂ F group into a sulfonic acid group after the precursor polymer having —SO ₂ F group is formed into a film.
(Y) A method of forming the polymer (A) or (B) into a film.

Method (x):
Examples of the method for forming a precursor polymer having a —SO ₂ F group into a film include an extrusion molding method, a pressure press molding method, and a stretching method.
Conversion of the —SO ₂ F group into a sulfonic acid group is performed by hydrolysis and acidification treatment.

Method (y):
As a method of forming the polymer (A) or (B) into a film, a method of coating and drying an electrolyte membrane coating solution containing the polymer (A) or (B) on a base film (cast method) ).

The electrolyte membrane coating solution is a dispersion in which the polymer (A) or (B) is dispersed in a dispersion medium containing alcohol and water.
The drying temperature is preferably 70 to 170 ° C.
After drying or simultaneously with drying, the polymer electrolyte membrane 40 is heat-treated (annealed).
The heat treatment temperature is preferably from 100 to 250 ° C, more preferably from 130 to 220 ° C, particularly preferably above the glass transition temperature (Tg) of the polymer (A) or (B) and at most (Tg + 100) ° C.

  The heat treatment time is preferably 5 minutes to 3 hours, and more preferably 10 minutes to 1 hour. If the heat treatment time is 5 minutes or more, the strength of the polymer electrolyte membrane 40 is sufficient. If the heat treatment time is 3 hours or less, the productivity will be good.

(Carbon layer)
The first carbon layer 14 and the second carbon layer 24 (hereinafter collectively referred to as a carbon layer) are provided between the first catalyst layer 12 and the first gas diffusion layer 16 and between the second catalyst layer 22 and It exists between the second catalyst layer 26 and contains carbon and an ion exchange resin.
The carbon layer may be present on either the cathode side or the anode side, but is preferably on the cathode side, and more preferably on both sides.

  Examples of carbon constituting the carbon layer include carbon powder such as carbon black, but carbon fibers having a fibrous shape are preferable, and carbon nanofibers having a fiber diameter of 1 to 1000 nm and a fiber length of 1000 μm or less are preferable. If the fiber diameter of the carbon nanofiber is too small, the manufacturing cost tends to be high, and the fiber structure may be easily destroyed during dispersion. If the fiber diameter is too large, it is difficult to produce an optimal void structure by coating the carbon layer. If the fiber length is too long, the dispersibility of the carbon layer coating solution for producing the carbon layer is deteriorated. The fiber diameter is particularly preferably 10 to 200 nm, and the fiber length is preferably 5 to 30 μm.

  Examples of such carbon nanofibers include vapor-grown carbon fibers and carbon nanotubes (single wall, double wall, multi-wall, cup laminated type, etc.), among others, carbon that is fine and has electron conductivity. Nanofibers are preferably used. Carbon nanofibers are tangled with the catalyst metal that constitutes the catalyst layer and the carbon carrier that is an electron conductive material supporting the catalyst metal at the interface between the carbon layer and the catalyst layer, thereby making point contact of this electron conductive material. Since a new conductive path is developed in addition to the conductive path due to, the electronic conductivity of the catalyst layer is improved.

  The ion exchange resin is not particularly limited as long as the adhesion between the binder of the carbon layer and the catalyst layer can be secured, and an ion exchange resin that can be used in the above-described solid polymer electrolyte membrane can be used. From the viewpoint of durability and the viewpoint of well dispersing the above-described carbon nanofibers, it is preferable to use the above-described fluorine-containing ion exchange resin.

  The weight ratio F / C of the ion exchange resin (F) and carbon (C) constituting the carbon layer is preferably 0.1 to 2.0. If the value of F / C is smaller than 0.1, the resulting carbon layer is liable to break, and the adhesion with the catalyst layer is lowered, which is not preferable. If it is larger than 2.0, the adhesion to the catalyst layer is good, but the carbon layer has a dense structure and the gas diffusion resistance becomes too large, which is not preferable. A carbon layer of 0.2 to 1.0 is preferred because the carbon layer is difficult to break, gas diffusibility is good, and adhesion to the catalyst layer is good.

  The thickness of the carbon layer is preferably 1 to 60 μm. When the thickness is less than 1 μm, it is not preferable because sufficient adhesion cannot be ensured in the subsequent hot pressing with the catalyst layer. If it is thicker than 60 μm, the amount of ink to be applied increases, coating unevenness is likely to occur, the adhesion cannot be stably obtained, and the effect of improving gas diffusibility is reduced, which is not preferable. When the thickness of the carbon layer is 2 to 40 μm, the effect of improving gas diffusibility and adhesion can be ensured, and the adhesion can be stably obtained, which is particularly preferable.

(Catalyst layer)
The first catalyst layer 12 and the second catalyst layer 22 (hereinafter collectively referred to as catalyst layers) include an electrode catalyst and an ion exchange resin.
The electrode catalyst preferably contains a noble metal. As the noble metal, platinum or a platinum alloy is preferable.
As the electrode catalyst, a supported catalyst in which platinum or a platinum alloy is supported on a carbon support is preferable.

Examples of the carbon carrier include activated carbon and carbon black.
The specific surface area of the carbon support is preferably 100 m ² / g or more. The specific surface area of the carbon support is measured by nitrogen adsorption on the carbon surface using a BET specific surface area apparatus.
Platinum alloys include platinum group metals other than platinum (ruthenium, rhodium, palladium, osmium, iridium), gold, silver, chromium, iron, titanium, manganese, cobalt, nickel, molybdenum, tungsten, aluminum, silicon, zinc And an alloy of one or more metals selected from the group consisting of tin and platinum. The platinum alloy may contain a metal alloyed with platinum and an intermetallic compound of platinum.
As the platinum alloy for the anode, when a fuel gas containing carbon monoxide is supplied to the anode, an alloy containing platinum and ruthenium is preferable from the viewpoint of the activity stability of the electrode catalyst.
The supported amount of platinum or platinum alloy is preferably 10 to 80% by mass in the electrode catalyst (100% by mass).

  As an ion exchange resin, the ion exchange resin which can be used with the solid polymer electrolyte membrane mentioned above can be used. From the viewpoint of durability, it is preferable to use the above-described fluorine-containing ion exchange resin.

  The ion exchange capacity of the non-fluorine ion exchange resin is preferably 1.6 to 3.5 meq / g dry resin, and 1.8 to 2.5 meq / g dry resin from the viewpoint of conductivity and gas diffusibility. Is more preferable.

The mass ratio (F ′ / C ′) between the mass of the ion exchange resin (F ′) and the mass of carbon in the electrode catalyst (C ′) is 0.2 to 2 from the viewpoint of electrode conductivity and water repellency. .5 is preferable, and 0.6 to 2.0 is more preferable. If F ′ / C ′ is 0.2 or more, the catalyst layer is difficult to break. If F ′ / C ′ is 2.5 or less, the catalyst layer 12 does not have a dense structure and gas diffusibility is good.
The catalyst layer may be a single layer or a plurality of layers. In the case of a plurality of layers, it is preferable to gradually increase F ′ / C ′ of each layer as it approaches the polymer electrolyte membrane 40.

The amount of the noble metal per unit area of the catalyst layer is preferably from 0.01 to 0.5 / cm ^2, more preferably ^{0.02~0.4mg / cm 2, 0.05~0.3mg / cm} 2 is Particularly preferred. When a catalyst layer having an amount of less than 0.1 mg / cm ² is applied and formed, the amount of the coating solution may be reduced and the uniformity of the resulting catalyst layer may be deteriorated. By using a supported catalyst in which platinum or a platinum alloy is supported at a low loading rate, the amount of coating liquid increases, so that a uniform catalyst layer can be obtained.

  The thickness of the catalyst layer is preferably 20 μm or less, and more preferably 1 to 15 μm from the viewpoint of improving gas diffusibility of the catalyst layer and improving the power generation characteristics of the polymer electrolyte fuel cell. Moreover, it is preferable that the thickness of a catalyst layer is uniform.

(Gas diffusion layer)
The first gas diffusion layer 16 and the second gas diffusion layer 26 (hereinafter collectively referred to as a gas diffusion layer) have a gas diffusible substrate.
The gas diffusing substrate is a porous substrate having conductivity. Examples of the gas diffusing substrate include carbon cloth, carbon paper, carbon felt and the like.
The gas diffusing substrate can be used as it is, but may be subjected to water repellent treatment as necessary. The water repellent treatment is preferably water repellent treated with a mixture of polytetrafluoroethylene (hereinafter referred to as PTFE) and carbon black. By performing the water repellent treatment, clogging of the pores of the gas diffusible substrate due to water or the like generated in the catalyst layer on the cathode side is suppressed, so that a decrease in gas diffusivity is suppressed. Further, by using carbon black during the water repellent treatment, the conductivity of the membrane electrode assembly 100 is improved.
The thickness of the gas diffusion layer is preferably 100 to 400 μm, and more preferably 140 to 350 μm.

(Method for producing membrane electrode assembly)
Examples of the method for producing the membrane electrode assembly 100 include the following method (I) or method (II).

(Method (I))
Method (I) includes the following steps (a) to (c), (a ′) to (c ′), (p) ((p−1) to (p-3)), (p ′) (( p′-1) to (p′-3)), (q1), and (q′1).
(A) As shown in FIG. 2 (1), a carbon layer coating liquid containing carbon and an ion exchange resin is applied onto a base film 50 to form a first carbon layer coating liquid layer 18. Forming step.
(B) After covering the first gas diffusion layer 16 on the first carbon layer coating liquid layer 18 formed in the step (a) as shown in FIGS. The step of drying the first carbon layer coating liquid layer 18 to form the first carbon layer 14.
(C) As shown in FIG. 2 (3), the base film 50 is peeled off from the laminate having the first carbon layer 14 and the first gas diffusion layer 16 formed in the step (b), and the laminate is obtained. (A) A step of obtaining 160.
(A ′) As shown in FIG. 2 (1), a carbon layer coating liquid containing carbon and an ion exchange resin is coated on the base film 50 to form a second carbon layer coating liquid layer 28. Forming.
(B ′) As shown in FIGS. 2 (1) and 2 (2), the second gas diffusion layer 26 is covered on the second carbon layer coating liquid layer 28 formed in the step (a ′). And then drying the second carbon layer coating liquid layer 28 to form the second carbon layer 24.
(C ′) As shown in FIG. 2 (3), the base film 50 is peeled off from the laminate having the second carbon layer 24 and the second gas diffusion layer formed in the step (b ′), and laminated. A step of obtaining a body (A ′) 260.
(P-1) As shown in FIG. 3 (1), on the base film 50, a catalyst layer coating solution containing a catalyst and an ion exchange resin is applied, dried and applied onto the base film 50. Forming the first catalyst layer 12;
(P-2) As shown in FIG. 3 (2), the catalyst layer 12 formed on the base film 50 is placed in contact with one surface of the solid polymer electrolyte membrane 40, and heat bonding is performed. The process to perform.
(P-3) A step of peeling the base film 50 from the first catalyst layer 12 formed on one surface of the solid polymer electrolyte membrane 40 as shown in FIG.
(P′-1) As shown in FIG. 3 (1), on the base film 50, a catalyst layer coating solution containing a catalyst and an ion exchange resin is applied and dried. A step of forming the second catalyst layer 22.
(P′-2) As shown in FIG. 3 (2), the catalyst layer 22 formed on the base film 50 is placed in contact with one surface of the solid polymer electrolyte membrane 40, and heat bonding is performed. The process of performing.
(P′-3) A step of peeling the base film 50 from the second catalyst layer 22 formed on one surface of the solid polymer electrolyte membrane 40 as shown in FIG.
(Q1) As shown in FIG. 4, the first carbon layer 14 of the laminate (A) 160 obtained in the step (c) and one surface of the solid polymer electrolyte membrane 40 in the step (p-3) The process of arrange | positioning so that it may contact | connect the 1st catalyst layer 12 formed in this, and heat-joining.
(Q′1) As shown in FIG. 4, the second carbon layer 24 of the laminate (A ′) 260 obtained in the step (c ′) and the solid polymer electrolyte membrane in the step (p′-3) The process of arrange | positioning so that the 2nd catalyst layer 22 formed in one side of 40 may contact, and heat-joining.

Step (a):
Examples of the base film 50 include a resin film. Examples of the material for the resin film include the following resins. From the viewpoint of heat resistance, chemical stability, and releasability, the substrate surface is preferably a fluorine-containing resin.
Non-fluorinated resin: polyethylene terephthalate, polyethylene, polypropylene, polyimide, etc.
Fluorine-containing resin: PTFE, ethylene-TFE copolymer (hereinafter referred to as ETFE), ethylene-hexafluoropropylene copolymer, TFE-perfluoro (alkyl vinyl ether) copolymer, polyvinylidene fluoride, and the like.
A laminated film obtained by laminating a fluorine-containing resin on the surface of a non-fluorinated resin film is preferable because it has high mechanical strength in addition to heat resistance, chemical stability, and releasability.

  The carbon layer coating solution is prepared by dispersing carbon in a solvent and dissolving or dispersing the ion exchange resin in the solvent.

When the ion exchange resin is a fluorine-containing ion exchange resin, the solvent is preferably an alcohol or a fluorine-containing solvent.
Examples of alcohols include ethanol, n-propanol, isopropanol, n-butanol, isobutanol, and tert-butanol. In order to increase the solubility of the fluorine-containing ion exchange resin, a mixed solvent of alcohols and water may be used.
The following are mentioned as a fluorine-containing solvent.
Hydrofluorocarbon: 2H-perfluoropropane, 1H, 4H-perfluorobutane, 2H, 3H-perfluoropentane, 3H, 4H-perfluoro (2-methylpentane), 2H, 5H-perfluorohexane, 3H-perfluoro (2-methylpentane) and the like.
Fluorocarbon: perfluoro (1,2-dimethylcyclobutane), perfluorooctane, perfluoroheptane, perfluorohexane and the like.
Hydrochlorofluorocarbon: 1,1-dichloro-1-fluoroethane, 1,1,1-trifluoro-2,2-dichloroethane, 3,3-dichloro-1,1,1,2,2-pentafluoropropane, 1,3-dichloro-1,1,2,2,3-pentafluoropropane and the like.
Fluoroether: 1H, 4H, 4H-perfluoro (3-oxapentane), 3-methoxy-1,1,1,2,3,3-hexafluoropropane and the like.
Fluorine-containing alcohol: 2,2,2-trifluoroethanol, 2,2,3,3,3-pentafluoro-1-propanol, 1,1,1,3,3,3-hexafluoro-2-propanol, etc. .

  When the ion exchange resin is a non-fluorine ion exchange resin, N, N-dimethylformamide, dimethyl sulfoxide, dimethylacetamide, N-methylpyrrolidone, methylene chloride, chloroform, carbon tetrachloride, 1,1,1- Examples include trichloroethane, 1,1,2-trichloroethane, trichloroethylene, and tetrachloroethylene.

  The solid content concentration of the coating solution for carbon layer containing carbon and ion exchange resin to be coated on the substrate is 2 to 25% by mass. If it is less than 2% by mass, the ion exchange resin dissolved in the solvent tends to enter the gas diffusion layer, which is not preferable. On the other hand, if it is larger than 25% by mass, the thickness of the coated carbon layer tends to be uneven, which is not preferable. The amount of 3 to 20% by mass is more preferable because the amount of intrusion into the gas diffusion layer can be easily controlled and a uniform carbon layer can be formed, and the stability of the carbon layer coating solution is also improved.

  The viscosity of the carbon layer coating solution is preferably 20 to 10,000 mPa · s when the shear rate is 1 (1 / S). If it is less than 20 mPa · s, the applied liquid is liable to enter the gas diffusion layer, which is not preferable. If it is greater than 10,000 mPa · s, the thickness of the coated carbon layer tends to be uneven, which is not preferable. 1000 to 5000 mPa · s is more preferred because it can form a uniform carbon layer with little penetration into the gas diffusion layer and improve the stability of the carbon layer coating solution.

Examples of the coating method include a batch coating method and a continuous coating method.
Examples of the batch coating method include a bar coater method, a spin coater method, and a screen printing method.
Examples of the continuous coating method include a post-measuring method or a pre-measuring method. The post-measuring method is a method in which an excess carbon layer coating solution is applied and the carbon layer coating solution is removed afterwards so as to have a predetermined thickness. The pre-weighing method is a method of applying a carbon layer coating solution in an amount necessary to obtain a predetermined thickness.
Examples of the post-measuring method include an air doctor coater method, a blade coater method, a rod coater method, a knife coater method, a squeeze coater method, an impregnation coater method, and a comma coater method.
Examples of pre-measuring methods include die coater method, reverse roll coater method, transfer roll coater method, gravure coater method, kiss roll coater method, cast coater method, spray coater method, curtain coater method, calendar coater method, extrusion coater method, etc. It is done.
As the coating method, a screen printing method or a die coater method is preferable from the viewpoint that a carbon layer coating liquid layer having a uniform thickness can be formed, and a die coater method is more preferable from the viewpoint of production efficiency.

Step (b):
The first carbon layer coating liquid layer 18 is formed by applying a carbon layer coating liquid, and a coating film in which all or part of the solvent contained in the carbon layer coating liquid remains. It is. The solvent remaining in the first carbon layer coating liquid layer 18 is preferably 20% by mass or more with respect to the solvent (100% by mass) contained in the carbon layer coating liquid.

  The first gas diffusion layer 16 may be placed on the first carbon layer coating liquid layer 18 immediately after the carbon layer coating liquid is applied on the base film 50. It may be after part of the solvent contained in the layer coating liquid layer 18 is evaporated. Usually, since water or alcohol is used as a solvent, the gas diffusion layer 16 is covered on the first carbon layer coating liquid layer 18 by coating the carbon film coating liquid on the base film 50. Within 5 minutes is preferable.

  A part of the solvent contained in the first carbon layer coating liquid layer 18 may be evaporated at room temperature, or may be evaporated by heating. Before covering the first gas diffusion layer 16 on the first carbon layer coating liquid layer 18, the heating temperature when evaporating a part of the solvent contained in the first carbon layer coating liquid layer 18 is 100 ° C. or less is preferable.

  After the first gas diffusion layer 16 is covered on the first carbon layer coating liquid layer 18, the drying temperature when drying the first carbon layer coating liquid layer 18 is preferably 50 to 150 ° C. . When the drying temperature is 50 ° C. or higher, the drying does not take time, and the ion exchange resin of the first carbon layer 14 is sufficiently heat-treated and stabilized. If the drying temperature is 150 ° C. or less, the first carbon layer 14 does not become non-uniform due to rapid evaporation of the solvent, and the base film is not greatly deformed by heat, and a stable and uniform carbon layer is formed. Is done. First, a large portion of the solvent is gradually removed at a temperature of 50 to 80 ° C., and further, the first carbon layer 14 obtained by drying and heat treatment at a temperature of 120 to 150 ° C. becomes uniform and stable, which is preferable. .

  When drying the first carbon layer coating liquid layer 18 in a continuous drying furnace, it is preferable to gradually increase the drying temperature, the drying time is short, and the ion exchange resin of the first carbon layer 14 is sufficient. The drying furnace inlet temperature is set to 50 to 80 ° C. and the drying furnace outlet temperature is set to 120 to 150 ° C. from the point that the heat treatment is performed to obtain a stable structure and the power generation characteristics of the polymer electrolyte fuel cell are improved. It is more preferable.

  The drying time when the first carbon layer coating liquid layer 18 is dried after the first gas diffusion layer 16 is covered on the first carbon layer coating liquid layer 18 is preferably 3 to 30 minutes. 5 to 15 minutes is more preferable. If the drying time is 3 minutes or more, the drying is sufficiently performed and the solvent hardly remains. If the drying time is 30 minutes or less, the productivity is improved, and even when the drying temperature is higher than 130 ° C., the base film is not greatly deformed by heat, and the first carbon is stably uniform. Layer 14 is formed. If the drying time is 5 to 15 minutes, the power generation characteristics of the polymer electrolyte fuel cell are sufficiently exhibited.

Step (c):
The step (c) may be performed immediately before the step (q1), and the laminate (A) 160 having the first carbon layer 14 and the first gas diffusion layer 16 is a base material until just before the step (q1). You may store in the state protected by the film 50. FIG.
Steps (a ′) to (c ′):
Steps (a ′) to (c ′) may be performed in the same manner as steps (a) to (c).
Step (p-1):
As the base film 50, a substrate film made of the same material as the base film used in the step (a) can be used.
As the solvent for the catalyst layer coating solution containing the catalyst and the ion exchange resin, a solvent that can be used in the carbon layer coating solution described in the step (a) can be used.
As a coating method, the method used in the step (a) can be used.

  5-25 mass% is preferable and, as for the solid content concentration of the coating liquid for catalyst layers, 6-12 mass% is more preferable. If the solid content concentration of the coating liquid for the catalyst layer is less than 5% by mass, the liquid viscosity becomes low and uneven coating tends to occur. On the other hand, when the solid content concentration is higher than 25% by mass, the liquid viscosity becomes too high and leveling becomes difficult, so that a catalyst layer having a uniform thickness cannot be formed, which is not preferable. Moreover, if the solid content concentration of the coating liquid for the catalyst layer is 6 to 12% by mass, the stability of the coating liquid for the catalyst layer is also improved, which is more preferable.

  When the shear rate is 1 (1 / S), the viscosity of the catalyst layer coating solution is preferably 200 to 8000 mPa · s, and more preferably 1000 to 4000 mPa · s. When the viscosity of the catalyst layer coating solution is 200 mPa · s or more, the coating unevenness of the catalyst layer coating solution is reduced. When the viscosity is 8000 mPa · s or less, the catalyst layer 12 having a uniform thickness can be formed. . When the viscosity of the catalyst layer coating solution is 1000 to 4000 mPa · s, the stability of the catalyst layer coating solution is improved.

  0.2-2.5 are preferable and, as for F / C in the coating liquid for catalyst layers, 0.6-2.0 are more preferable. If F / C is 0.2 or more, the catalyst layer 12 is difficult to break. If F / C is 2.5 or less, the catalyst layer 12 does not have a dense structure, and gas diffusibility is good. If F / C is 0.6 to 2.0, the catalyst layer 12 is more difficult to crack and the gas diffusibility is also better.

  As for the drying temperature at the time of drying a catalyst layer, 50-150 degreeC is preferable. When the drying temperature is 50 ° C. or higher, drying does not take time, and the ion exchange resin of the catalyst layer 12 is sufficiently heat-treated and stabilized. When the drying temperature is 150 ° C. or lower, the catalyst layer 12 is hardly deteriorated and the catalyst layer 12 does not burn.

  When the catalyst layer is dried in a continuous drying furnace, the drying temperature is preferably gradually increased, the drying time is short, and the ion exchange resin of the catalyst layer 12 is sufficiently heat-treated to form a stable structure. From the viewpoint of improving the power generation characteristics of the polymer electrolyte fuel cell, it is more preferable that the drying furnace inlet temperature is 50 to 80 ° C. and the drying furnace outlet temperature is 120 to 150 ° C.

  The drying time for drying the catalyst layer is preferably 3 to 30 minutes, more preferably 5 to 15 minutes. If the drying time is 3 minutes or more, the drying is sufficiently performed and the solvent hardly remains. When the drying time is 30 minutes or less, the productivity is improved, and the deterioration of the catalyst layer 12 is unlikely to proceed even under a high temperature condition where the drying temperature is higher than 130 ° C. If the drying time is 5 to 15 minutes, the power generation characteristics of the polymer electrolyte fuel cell are sufficiently exhibited.

Step (p-2):
When the first catalyst layer 12 formed on the base film 50 and the polymer electrolyte membrane 40 are heat-bonded, the first catalyst layer 12 is formed on one surface of the solid polymer electrolyte membrane 40, and the other surface. The second catalyst layer 22 may be disposed at the same time, and may be heat-bonded at the same time (step (p-2) and step (p′-2) are simultaneously performed), or may be heat-bonded separately. From the viewpoint of production efficiency, it is preferable to perform the step (p-2) and the step (p′-2) at the same time.

Examples of the bonding method include a hot press method, a hot roll press, ultrasonic fusion, and the like, and the hot press method is preferable from the viewpoint of in-plane uniformity.
120-160 degreeC is preferable and, as for press temperature (temperature of the press plate in a press), 130-150 degreeC is more preferable. If the pressing temperature is 120 ° C. or higher, bonding is sufficiently performed, and an increase in resistance due to poor contact is suppressed. When the pressing temperature is 160 ° C. or lower, the catalyst layer 12 is hardly deteriorated and the polymer electrolyte membrane 40 is not easily deformed. When the pressing temperature is 130 to 150 ° C., the power generation characteristics and durability of the polymer electrolyte fuel cell are good.

  The pressing pressure is preferably 0.5 to 5 MPa, more preferably 1 to 4 MPa. When the pressing pressure is 0.5 MPa or more, the bonding is sufficiently performed, and an increase in resistance due to poor contact is suppressed. When the pressing pressure is 5 MPa or less, the catalyst layer is hardly deteriorated and the polymer electrolyte membrane 40 is hardly deformed. When the pressing pressure is 1 to 4 MPa, the power generation characteristics and durability of the polymer electrolyte fuel cell are good.

  The pressing time is preferably 0.5 to 10 minutes, and more preferably 1 to 5 minutes. If the pressing time is 0.5 minutes or more, the bonding is sufficiently performed and the increase in resistance due to poor contact is suppressed. If the pressing time is 10 minutes or less, the catalyst layer is hardly deteriorated and the polymer electrolyte membrane 40 is not easily deformed. If the pressing time is 1 to 5 minutes, the power generation characteristics and durability of the polymer electrolyte fuel cell will be good.

Step (p-3):
The substrate film 50 may be peeled off immediately before the step (q1) described later, and may be stored in a state protected by the substrate film 50 until immediately before.
Steps (p′-1) to (p′-3):
The steps (p′-1 ′) to (p′-3) may be performed in the same manner as the steps (p-1) to (p-3).
Step (q1), (q′1):
When the first carbon layer 14 of the laminate (A) 160 and the first catalyst layer 12 formed on one surface of the solid polymer electrolyte membrane 40 are heat-bonded, the laminate (A) 160 The first carbon layer 14 and the first catalyst layer 12 formed on one surface of the solid polymer electrolyte membrane 40 are disposed so as to be in contact with each other, and the second carbon layer of the laminate (A ′) 260 is further disposed. 24 and the second catalyst layer 22 formed on one surface of the solid polymer electrolyte membrane 40 are arranged so as to be in contact with each other, and are heated and joined at the same time (step (q1) and step (q′1) are simultaneously performed). Alternatively, each of them may be separately heated and bonded. From the viewpoint of production efficiency, it is preferable to perform the step (q1) and the step (q′1) simultaneously.
About the method and joining conditions of heat joining, it can carry out with the method and conditions described by the process (p-2).

(Method (II))
Method (II) is a method having the following steps (a) to (e), (p) ((p-1) to (p-3)), (q2), and (q′2).
Steps (a) to (c) described in method (I).
(D) As shown in FIG. 5 (1), a carbon layer coating solution containing carbon and an ion exchange resin is applied onto the second gas diffusion layer 26, dried, and then the second carbon layer 24. Forming.
(E) As shown in FIG. 5 (2), on the second carbon layer 24, a catalyst layer coating liquid containing a catalyst and an ion exchange resin is applied and dried to form the second catalyst layer 22. To obtain a laminate (B) 360 having the second gas diffusion layer 26, the second carbon layer 24, and the second catalyst layer 22.
(P-1) As shown in FIG. 6 (1), on the base film 50, a catalyst layer coating solution containing a catalyst and an ion exchange resin is applied, dried and applied onto the base film 50. Forming the catalyst layer 12;
(P-2) As shown in FIG. 6 (2), the catalyst layer 22 formed on the base film 50 is disposed on one surface of the solid polymer electrolyte membrane 40 so as to contact the solid polymer electrolyte membrane. The process of arrange | positioning so that the catalyst layer 12 formed on the base film 50 may contact | connect the other surface of the film | membrane 40, and performing heat joining.
(P-3) A step of peeling the base film 50 from the first catalyst layer 12 formed on one surface of the solid polymer electrolyte membrane 40 as shown in FIG. 6 (3).
(Q2) As shown in FIG. 7, the first carbon layer 14 of the laminate (A) 160 obtained in the step (c) and one surface of the solid polymer electrolyte membrane 40 in the step (p-3) The process of arrange | positioning so that it may contact | connect the 1st catalyst layer 12 formed in this, and heat-joining.
(Q′2) As shown in FIG. 7, the second catalyst layer 22 of the laminate (B) 360 obtained in the step (e) and the first catalyst layer 12 of the solid polymer electrolyte membrane 40 are formed. The process of arrange | positioning and heat-joining the surface which is not done in contact.

Step (d):
The material, composition, preparation method and the like of the carbon layer coating solution are the same as in step (a) of method (I).
The drying conditions for the second carbon layer 24 are the same as those in the step (b) of the method (I).
Step (e):
The material, composition, and preparation method of the catalyst layer coating solution, the coating method, coating conditions, and drying conditions of the catalyst layer coating solution are the same as in step (p-1) of method (I).
Steps (p-1) to (p-3):
Steps (p-1) to (p-3) may be performed in the same manner as steps (p-1) to (p-3) of method (I).
Step (q2), (q′2):
Step (q2) and step (q′2) can be performed simultaneously or separately. From the viewpoint of production efficiency, it is preferable to simultaneously perform the step (q2) and the step (q′2).
About the method and joining conditions of heat joining, it can carry out with the method and conditions described by the process (p-2) of the method (I).

[Second Embodiment]
FIG. 8 is a cross-sectional view showing another example of a membrane electrode assembly for a polymer electrolyte fuel cell. The polymer electrolyte membrane electrode assembly 200 includes a first electrode 120 having a first catalyst layer 12, a first carbon layer 14, and a first gas diffusion layer 16, a second catalyst layer 22, and a second catalyst layer 22. The second electrode 230 having the gas diffusion 26 and the solid polymer electrolyte membrane 40 between the first catalyst layer 12 of the first electrode 120 and the second catalyst layer 22 of the second electrode 230. It is provided.
In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals as those in FIG.
The first electrode 120 may be an anode or a cathode, but the first electrode 120 is preferably a cathode. The second electrode 230 is a cathode when the first electrode 120 is an anode, and is an anode when the first electrode 120 is a cathode.

(Method for producing membrane electrode assembly)
Examples of the method for producing the membrane electrode assembly 200 include the following method (III) or method (IV).

(Method (III))
Method (III) includes the following steps (a) to (c), (p) ((p-1) to (p-3)), (p ′) ((p′-1) to (p′−). 3)), (q3) and (q′3).
Steps (a) to (c) described in method (I).
Steps (p-1) to (p-3) and (p′-1) to (p′-3) described in the method (I).
(Q3) As shown in FIG. 9, the first carbon layer 14 of the laminate (A) 160 obtained in the step (c) and one surface of the solid polymer electrolyte membrane 40 in the step (p-3) The process of arrange | positioning so that it may contact | connect the 1st catalyst layer 12 formed in this, and heat-joining.
(Q′3) As shown in FIG. 9, the second gas diffusion layer 26 and the second catalyst layer 22 formed on one surface of the solid polymer electrolyte membrane 40 in the step (p′-3) The process of arrange | positioning so that it may touch and heat-joining.

Step (q3), (q′3):
Step (q3) and step (q′3) can be performed simultaneously or separately. From the viewpoint of production efficiency, it is preferable to perform the step (q3) and the step (q′3) at the same time.

  About the method and joining conditions of heat joining, it can carry out with the method and conditions described by the process (p-2) of the method (I).

(Method (IV))
Method (IV) is a method having the following steps (a) to (c), (f), (p) ((p-1) to (p-3)) and (q4).
Steps (a) to (c) described in method (I).
(F) On the second gas diffusion layer 26, a catalyst layer coating solution containing a catalyst and an ion exchange resin is applied and dried to form the second catalyst layer 22, and the second gas A step of obtaining a laminate (C) 460 having a diffusion layer and a second catalyst layer.
Steps (p-1) to (p-3) described in method (II)
(Q4) As shown in FIG. 10, the first carbon layer 14 of the laminate (A) 160 obtained in the step (c) and one surface of the solid polymer electrolyte membrane 40 in the step (p-3) The process of arrange | positioning so that it may contact | connect the 1st catalyst layer 12 formed in this, and heat-joining.
(Q′4) As shown in FIG. 10, the second catalyst layer 22 of the laminate (C) 460 obtained in the step (f) and the first catalyst layer 12 of the solid polymer electrolyte membrane 40 are formed. The process of arrange | positioning and heat-joining the surface which is not done in contact.

Step (f):
The material, composition, and preparation method of the catalyst layer coating solution, the coating method, coating conditions, and drying conditions of the catalyst layer coating solution are the same as in step (p-1) of method (I).

Step (q4), (q′4):
Step (q4) and step (q′4) can be performed simultaneously or separately. From the viewpoint of production efficiency, it is preferable to simultaneously perform the step (q4) and the step (q′4).

  About the method and joining conditions of heat joining, it can carry out with the method and conditions described by the process (p-2) of the method (I).

  According to the method for producing the polymer electrolyte membrane electrode assembly 100 in the first embodiment and the method for producing the polymer electrolyte membrane electrode assembly 200 in the second embodiment described above, at least one of the electrodes However, after the carbon layer coating liquid layer is formed on the base film by coating the carbon layer coating liquid layer, the carbon layer coating liquid layer is completely dried without drying the carbon layer coating liquid layer. Since the carbon layer coating liquid layer is covered with a gas diffusion layer in a state containing the solvent, and the carbon layer coating liquid layer is dried in this state to form a carbon layer. Part of the working liquid layer penetrates into the gas diffusion layer, the adhesion between the resulting carbon layer and the gas diffusion layer is improved, and a large amount of ion exchange resin is present on the surface side of the carbon layer. Therefore, when the carbon layer and the catalyst layer formed on the polymer electrolyte membrane are heat-bonded, the adhesive force at the interface between the carbon layer and the catalyst layer increases, the resistance at the interface decreases, and the solid polymer type The power generation characteristics of the fuel cell are improved. In addition, even when used in an environment where drying and wetting are repeated, the adhesion at the interface between the carbon layer and the catalyst layer is high, so that peeling does not occur easily, and the output voltage of the polymer electrolyte fuel cell decreases. Can be suppressed. Therefore, it is excellent in dry and wet repeated resistance.

[Third Embodiment]
FIG. 11 is a cross-sectional view showing another example of a membrane electrode assembly for a polymer electrolyte fuel cell. The membrane electrode assembly 300 includes a first electrode 320 having a first catalyst layer 12, a first carbon layer A 14-1, a first carbon layer B 14-2, and a first gas diffusion layer 16; The second electrode 330 having the catalyst layer 22, the second carbon layer A 24-1, the second carbon layer B 24-2, and the second gas diffusion layer 26, and the first catalyst layer of the first electrode 320 12 and the second catalyst layer 22 of the second electrode 330 are provided with a solid polymer electrolyte membrane 40.
In the present embodiment, the same components as those in the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.
The first electrode 320 may be an anode or a cathode, but the first electrode 320 is preferably a cathode. The second electrode 330 is a cathode when the first electrode 320 is an anode, and is an anode when the first electrode 320 is a cathode.

(Carbon layer A and carbon layer B)
The first carbon layer A14-1 and the first carbon layer B14-2 (hereinafter collectively referred to as the carbon layer A and the carbon layer B) are formed by the first catalyst layer 12 and the first gas diffusion layer 16. In between, including carbon and ion exchange resins.
The second carbon layer A 24-1 and the second carbon layer B 24-2 (hereinafter collectively referred to as carbon layer A and carbon layer B) are formed between the second catalyst layer 22 and the second gas diffusion layer 26. In between, including carbon and ion exchange resins.
The material and composition of the carbon layer A and the carbon layer B are the same as those of the carbon layer described in the first embodiment.
The thickness of the carbon layer A is preferably 0.5 to 20 μm, and if the thickness is 1 to 10 μm, a layer having a large amount of ion-exchange fat components is reliably formed. It is possible and particularly preferred.

  The thickness of the carbon layer B is preferably 1 to 40 μm, and a thickness of 3 to 30 μm is particularly preferable because uneven coating does not occur and a uniform layer is obtained.

(Method for producing membrane electrode assembly)
Examples of the method for producing the membrane electrode assembly 300 include the following method (V) or method (VI).

(Method (V))
Method (V) includes the following steps (g) to (j), (g ′) to (j ′), (p) ((p−1) to (p-3)), (p ′) (( p′-1) to (p′-3)), (q5), and (q′5).
(G) As shown in FIG. 12 (1), a carbon layer A coating solution containing carbon and an ion exchange resin is applied onto the substrate film 50 and dried to be a first carbon layer A 14-1. Forming.
(H) As shown in FIG. 12 (2), a carbon layer B coating solution containing carbon and an ion exchange resin is applied onto the first carbon layer A14-1 formed in the step (g). And forming the first carbon layer B coating liquid layer 38.
(I) As shown in FIGS. 12 (2) and (3), the first gas diffusion layer 16 was covered on the first carbon layer B coating liquid layer 38 formed in the step (h). Then, the process of drying the carbon layer B coating liquid layer 38, and forming 1st carbon layer B14-2.
(J) As shown in FIG. 12 (4), a laminate having the first carbon layer A14-1, the first carbon layer B14-2, and the first gas diffusion layer 16 formed in the step (i). The base film 50 is peeled from the step to obtain a laminate (D) 560.
(G ′) As shown in FIG. 12 (1), a carbon layer A coating solution containing carbon and an ion exchange resin is applied onto the base film 50 and dried to form a second carbon layer A 24-. Forming 1.
(H ′) As shown in FIG. 12 (2), a coating solution for carbon layer B containing carbon and an ion exchange resin is formed on the second carbon layer A24-1 formed in step (g ′). A step of forming the second carbon layer B coating liquid layer 48 by coating.
(I ′) As shown in FIGS. 12 (2) and 12 (3), the second gas diffusion layer 26 is formed on the second carbon layer B coating liquid layer 48 formed in the step (h ′). A step of drying the carbon layer B coating liquid layer 48 to form a second carbon layer B 24-2 after being covered.
(J ′) As shown in FIG. 12 (4), the second carbon layer A24-1, the second carbon layer B24-2, and the second gas diffusion layer 26 formed in the step (i ′) are included. The process of peeling the base film 50 from a laminated body and obtaining a laminated body (D ') 660.
Steps (p-1) to (p-3) and (p′-1) (p′-3) described in the method (I).
(Q5) As shown in FIG. 13, the first carbon layer A14-1 of the laminate (D) 560 obtained in the step (j) and one of the solid polymer electrolyte membranes 40 in the step (p-3) The process of arrange | positioning so that the 1st catalyst layer 12 formed in the surface may contact | connect, and heat-joining.
(Q′5) As shown in FIG. 13, the second carbon layer A24-1 of the laminate (D ′) 660 obtained in the step (j ′) and the solid polymer in the step (p′-3) The process of arrange | positioning so that the 2nd catalyst layer 22 formed in one surface of the electrolyte membrane 40 may contact | connect, and heat-joining.

Step (g):
The material, composition, preparation method, and the like of the first carbon layer A coating solution are the same as in step (a) of method (I). The drying conditions for the first carbon layer A coating liquid layer are the same as in step (b) of method (I).
Step (h):
The material, composition, preparation method, and the like of the first carbon layer B coating solution are the same as in step (a) of method (I).
Step (i):
The drying conditions of the carbon layer B coating liquid layer 38 are the same as those in the step (b) of the method (I).
Step (j):
The step (j) may be performed immediately before the step (q5), and the laminate (D) 560 may be stored in a state protected by the base film 50 until immediately before the step (q5).
Steps (h ′) to (j ′):
Steps (h ′) to (j ′) may be performed in the same manner as steps (h) to (j).
Step (q5), (q′5):
Step (q5) and step (q′5) can be performed simultaneously or separately. From the viewpoint of production efficiency, it is preferable to perform the step (q5) and the step (q′5) at the same time.
About the method and joining conditions of heat joining, it can carry out with the method and conditions described by the process (p-2) of the method (I).

(Method (VI))
Method (VI) includes the following steps (g) to (j), (k) to (m), (p) ((p-1) to (p-3)), (q6), (q′6 ).
Steps (g) to (j) described in the method (V).
(K) As shown in FIG. 14 (1), on the second gas diffusion layer 26, a second carbon layer B coating solution containing carbon and an ion exchange resin is applied and dried. Forming a carbon layer B24-2.
(L) As shown in FIG. 14 (2), a second carbon layer B coating solution containing carbon and an ion exchange resin is applied and dried on the second carbon layer B24-2, Forming a second carbon layer A24-1.
(M) As shown in FIG. 14 (3), a catalyst layer coating liquid containing a catalyst and an ion exchange resin is applied onto the second carbon layer A24-1, and dried to form a second catalyst. Step of forming layer 22 to obtain laminate (E) 760 having second catalyst layer 22, second carbon layer A 24-1, second carbon layer B 24-2, and second gas diffusion layer 26. .
Steps (p-1) to (p-3) described in the method (II).
(Q6) As shown in FIG. 15, the first carbon layer A14-1 of the laminate (D) 560 obtained in step (j) and the first carbon layer A14-1 formed on one surface of the solid polymer electrolyte membrane 40 The process of arrange | positioning so that the 1 catalyst layer 12 may be contact | connected, and heat-joining.
(Q′6) As shown in FIG. 15, the second catalyst layer 22 of the laminate (E) 760 obtained in the step (m) and the first catalyst layer 12 of the solid polymer electrolyte membrane 40 are formed. The process of arrange | positioning and heat-joining the surface which is not done in contact.

Step (k):
The material, composition, preparation method, and the like of the second carbon layer B coating solution are the same as in step (a) of method (I). The drying conditions are the same as in step (b) in method (I).
Step (l):
The material, composition, preparation method, and the like of the second carbon layer A coating solution are the same as in step (a) of method (I). The drying conditions are the same as in step (b) in method (I).
Step (m):
The material, composition, and preparation method of the catalyst layer coating solution, the coating method, coating conditions, and drying conditions of the catalyst layer coating solution are the same as in step (p-1) of method (I).
Step (q6):
Step (q6), (q′6):
Step (q6) and step (q′6) can be performed simultaneously or separately. From the viewpoint of production efficiency, it is preferable to perform the step (q6) and the step (q′6) at the same time.
About the method and joining conditions of heat joining, it can carry out with the method and conditions described by the process (p-2) of the method (I).
Note that the second carbon layer A and the second carbon layer B formed by coating on the second gas diffusion layer 36 are not necessarily two or more, and may be either one.

[Fourth Embodiment]
FIG. 16 is a cross-sectional view showing another example of a membrane electrode assembly for a polymer electrolyte fuel cell. The membrane electrode assembly 400 includes a first electrode 320 having a first catalyst layer 12, a first carbon layer A 14-1, a first carbon layer B 14-2 and a first gas diffusion layer 16, and a second electrode 320. Between the second electrode 230 having the catalyst layer 22 and the second gas diffusion layer 26, and the first catalyst layer 12 of the first electrode 320 and the second catalyst layer 22 of the second electrode 230. The solid polymer electrolyte membrane 40 is provided.
The first electrode 320 may be an anode or a cathode, but the first electrode 320 is preferably a cathode. The second electrode 230 is a cathode when the first electrode 320 is an anode, and is an anode when the first electrode 320 is a cathode.
In the present embodiment, the same components as those in the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.

(Method for producing membrane electrode assembly)
As a manufacturing method of the membrane electrode assembly 400, the following method (VII) or method (VIII) is mentioned, for example.

(Method (VII))
Method (VII) includes the following steps (g) to (j), (p) ((p-1) to (p-3)), (p ') ((p'-1) to (p'- 3)), (q7), (q′7).
Steps (g) to (j) described in the method (V).
Steps (p-1) to (p-3) and (p′-1) to (p′-3) described in the method (I).
(Q7) As shown in FIG. 17, the first carbon layer A14-1 of the laminate (D) 560 obtained in the step (j) and one of the solid polymer electrolyte membranes 40 in the step (p-3) The process of arrange | positioning so that the 1st catalyst layer 12 formed in the surface may contact | connect, and heat-joining.
(Q′7) As shown in FIG. 17, the second gas diffusion layer 26 and the second catalyst layer 22 formed on one surface of the solid polymer electrolyte membrane 40 in the step (p′-3) The process of arrange | positioning so that it may touch and heat-joining.
Step (q7), (q′7):
Step (q7) and step (q′7) can be performed simultaneously or separately. From the viewpoint of production efficiency, it is preferable to perform the step (q7) and the step (q′7) at the same time.
About the method and joining conditions of heat joining, it can carry out with the method and conditions described by the process (p-2) of the method (I).

(Method (VIII))
Method (VIII) is a method having the following steps (g) to (j), (f), (p) ((p-1) to (p-3)) and (q8).
Steps (g) to (j) described in the method (V).
Step (f) described in method (IV).
Steps (p-1) to (p-3) described in the method (II).
(Q8) As shown in FIG. 18, the first carbon layer A14-1 of the laminate (D) 560 obtained in the step (j) and one of the solid polymer electrolyte membranes 40 in the step (p-3) The process of arrange | positioning so that the 1st catalyst layer 12 formed in the surface may contact | connect, and heat-joining.
(Q′8) As shown in FIG. 18, the second catalyst layer 22 of the laminate (C) 460 obtained in the step (f) and the first catalyst layer 12 of the solid polymer electrolyte membrane 40 are formed. The process of arrange | positioning and heat-joining the surface which is not done in contact.
Step (q8), (q′8):
Step (q8) and step (q′8) can be performed simultaneously or separately. From the viewpoint of production efficiency, it is preferable to perform the step (q8) and the step (q′8) at the same time.
About the method and joining conditions of heat joining, it can carry out with the method and conditions described by the process (p-2) of the method (I).

  In the manufacturing method of the polymer electrolyte membrane electrode assembly described in the first embodiment and the second embodiment, after coating a carbon layer coating liquid containing carbon and an ion exchange resin on a substrate, Cover the gas diffusion layer on it and dry it to produce a layer with a lot of ion-exchange resin components at the substrate side interface. However, the porosity of the gas diffusion layer surface is high, and the carbon layer coating solution is absorbed very much. When it has the property which is easy to do, the layer with many ion exchange resin components may not fully be formed in the said base material side interface.

  According to the method for manufacturing the polymer electrolyte membrane electrode assembly 300 described in the third embodiment and the method for manufacturing the polymer electrolyte membrane electrode assembly 400 described in the fourth embodiment described above, at least By making the carbon layer of one electrode into two or more layers, first, the carbon layer A coating solution is applied and dried on the base film to form the carbon layer A having a large amount of ion exchange resin components at the base film side interface. Then, a carbon layer excellent in gas diffusibility and adhesion can be obtained by applying a coating solution for carbon layer B, covering the gas diffusion layer thereon and drying by adhesion.

  That is, after the carbon layer A is formed on the base film 50, the carbon layer B coating liquid layer is formed by coating the carbon layer B coating liquid, and then the carbon layer B coating liquid layer. In a state containing the solvent without completely drying, the gas diffusion layer 16 is covered on the carbon layer B coating liquid layer, and the carbon layer B coating liquid layer is dried and formed in this state. Therefore, a part of the carbon layer B coating liquid layer penetrates into the gas diffusion layer, the adhesion between the obtained carbon layer B and the gas diffusion layer is improved, and there are many ion exchange resins on the surface side of the carbon layer A. It comes to exist. Therefore, when the carbon layer A and the catalyst layer formed on the polymer electrolyte membrane are heat-bonded, the adhesive force at the interface between the carbon layer A and the catalyst layer increases, the resistance at the interface decreases, The power generation characteristics of the molecular fuel cell are improved. In addition, even when used in an environment where drying and wetting are repeated, the adhesion at the interface between the carbon layer and the catalyst layer is high, so that peeling does not occur easily, and the output voltage of the polymer electrolyte fuel cell decreases. Can be suppressed. Therefore, it is excellent in dry and wet repeated resistance.

[Solid polymer fuel cell]
A polymer electrolyte fuel cell can be obtained by disposing separators in which grooves serving as gas flow paths are formed on both surfaces of the membrane electrode assembly obtained by the production method of the present invention.
Examples of the separator include a separator made of various conductive materials such as a metal separator, a carbon separator, and a separator made of a material in which graphite and a resin are mixed.
In the polymer electrolyte fuel cell, power is generated by supplying a gas containing oxygen to the cathode and a gas containing hydrogen to the anode. The membrane electrode assembly obtained by the production method of the present invention can also be applied to a methanol fuel cell in which methanol is supplied to the anode to generate power.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples.

Examples 1 to 10 are examples, and examples 11 and 12 are comparative examples.
(Copolymer polymer (A))
A polymer (A) (ion exchange capacity 1.1 meq / g dry resin) composed of a unit based on TFE and a repeating unit represented by the following formula (11) was prepared.

(Copolymer polymer (B))
A copolymer (B) (ion exchange capacity 1.51 meq / g dry resin) composed of units based on TFE and repeating units represented by the following formulas (42) and (11) was prepared.

(Polymer electrolyte membrane)
280 g of polymer (A), 432 g of ethanol, and 288 g of water were charged in a 2 L autoclave, sealed, mixed and stirred at 105 ° C. for 6 hours with a double helical blade, the solid content concentration was 28% by mass, and the solvent composition was ethanol / water. = 60/40 (mass ratio) uniform liquid (hereinafter referred to as solution (D)). A 300 ml glass round bottom flask was charged with 100 g of the solution (D) and 0.47 g of cerium carbonate hydrate (Ce ₂ (CO ₃ ) ₃ · 8H ₂ O), and the room temperature was measured with a PTFE meniscus blade. For 8 hours. Although bubbles were generated due to the generation of CO ₂ from the start of stirring, finally, a uniform and transparent electrolyte membrane coating solution having a solid content concentration of 28.1% by mass was prepared.

  On the ETFE film (base film), this electrolyte membrane coating solution is filtered with a polypropylene filter having an average pore diameter of 3 μm and then coated with a die coater so that the dry film thickness is 25 μm, followed by drying at 90 ° C. It was dried in the vessel for 10 minutes and further annealed at 150 ° C. for 30 minutes to obtain a polymer electrolyte membrane (E25).

250 g of the polymer (B), 375 g of ethanol and 375 g of water were charged in a 2 L autoclave, sealed, and mixed and stirred at 120 ° C. for 12 hours with a double helical blade to dissolve the polymer. Next, 121 g of water was added to the autoclave under pressure, and the mixture was stirred at 120 ° C. for 1 hour. After cooling the temperature to 55 ° C, while stirring the solution, nitrogen gas was passed through the gas phase in the autoclave for 3 hours to remove the diethyl ether generated during dissolution out of the system, cooled to room temperature, and the solid content concentration A uniform liquid (hereinafter referred to as solution (G)) having 22.8% by mass and a solvent composition of ethanol / water = 40/60 (mass ratio) was obtained. A 300 ml glass round bottom flask was charged with 100 g of the solution (G) and 0.35 g of cerium carbonate hydrate (Ce ₂ (CO ₃ ) ₃ · 8H ₂ O), and the room temperature was measured with a PTFE meniscus blade. And stirred for 16 hours at a temperature of 45 ° C. for dissolution. Bubbles were generated due to the generation of CO ₂ from the start of stirring, but finally a uniform and transparent electrolyte membrane coating solution having a solid content concentration of 22.9% by mass was prepared.

  On the ETFE film (base film), this electrolyte membrane coating solution was applied using a die coater so that the dried film thickness was 20 μm, 25 μm and 30 μm after filtration through a polypropylene filter having an average pore diameter of 3 μm. The polymer electrolyte membranes (H20), (H25), and (H30) were obtained by drying in a 90 ° C. dryer for 10 minutes and further annealing at 180 ° C. for 30 minutes.

(Gas diffusion layer)
As a gas diffusive substrate constituting the gas diffusion layer, carbon paper whose surface is water repellent treated with a dispersion containing carbon black particles and polytetrafluoroethylene (product name: H2315T10AC1 manufactured by NOK) (hereinafter referred to as carbon) Paper (J).) Was prepared. In addition, carbon paper (J ′) was prepared by laminating a carbon fiber (MLD30, fiber diameter: 7 μm, fiber length: 30 μm) and polymer (A) mixture layer of 10 μm on this carbon paper.

(Coating solution for anode catalyst layer for coating on base film)
20.3 g of a catalyst (platinum supported amount: 20 mass%) in which platinum is supported on a heat-treated carbon support (specific surface area 200 m ² / g) is added to 168.2 g of distilled water, and an ultrasonic application device is used. Then, 268.8 g of ethanol was added, and the mixture was stirred well to prepare an electrode catalyst dispersion.
To the electrode catalyst dispersion, 42.7 g of the solution (G) prepared in the preparation of the polymer electrolyte membrane was added and stirred well to prepare a catalyst layer coating solution (KA). The obtained anode catalyst layer coating liquid has a solid content concentration of 6% by mass and a solvent composition ratio of ethanol / water = 60/40 (mass ratio). (Coating solution for cathode catalyst layer for coating on base film)
34.3 g of a catalyst in which a platinum / cobalt alloy is supported on a carbon support (specific surface area 800 m ² / g) (metal loading: 62% by mass) is added to 193.2 g of distilled water, and an ultrasonic application device Then, 203.8 g of ethanol was further added and stirred well to prepare an electrode catalyst dispersion.
To the electrode catalyst dispersion, 68.7 g of the solution (G) prepared at the time of preparing the polymer electrolyte membrane was added and stirred well to prepare a catalyst layer coating solution (KC). The resulting cathode catalyst layer coating solution has a solid content concentration of 10% by mass and a solvent composition ratio of ethanol / water = 50/50 (mass ratio).

(Coating solution for carbon layer)
Vapor growth carbon fiber (trade name: VGCF-H, manufactured by Showa Denko KK, fiber diameter: about 150 nm, fiber length: 10-20 μm) was added to 35.3 g of ethanol 181.9 g and distilled water 194.6 g and stirred well. . To this, 88.2 g of the solution (D) prepared in the preparation of the polymer electrolyte membrane was added, stirred well, further mixed and pulverized using a homogenizer, and this was combined with the carbon layer coating solution (M1). did.
Similarly, 186.5 g of ethanol and 169.8 g of distilled water were added to 35.3 g of vapor grown carbon fiber (trade name: VGCF-H, manufactured by Showa Denko KK, fiber diameter: about 150 nm, fiber length: 10 to 20 μm). Stir well. To this was added 108.4 g of the solution (G) prepared in the preparation of the polymer electrolyte membrane, stirred well, further mixed and pulverized using a homogenizer, and this was combined with the carbon layer coating solution (M2). did.

[Example 1]
Steps (a-1) and (a′-1):
A film in which an ETFE film is laminated on both sides of a polyethylene terephthalate film is used as a base film, and a carbon layer coating solution (M1) is formed thereon so that the total weight of carbon and ion exchange trees is 0.8 mg / cm ^2. Coating was performed using a die coater to form a carbon layer coating liquid layer.

Step (b-1) (b′-1):
Immediately after forming the carbon layer coating liquid layer, the carbon layer coating liquid layer is covered with carbon paper (J), and the carbon layer coating liquid layer is dried in an oven at 80 ° C. for 5 minutes, and further 120 It was dried in a dryer at 5 ° C. for 5 minutes to form a carbon layer having a thickness of 9 μm.

Steps (c-1) and (c′-1):
The laminates (A-1) and (A′-1) in which the base film was peeled off from the laminate obtained in the steps (b-1) and (b′-1) and the carbon layer was formed on the carbon paper were obtained. Obtained.

Steps (p-1-1) to (p-3-1), (p′-1-1) to (p′-3-1):
A film in which an ETFE film is laminated on both sides of a polyethylene terephthalate film is used as a base film, and an anode catalyst layer coating solution (KA) is used on the film, using a die coater so that the platinum amount is 0.1 mg / cm ^2. The substrate film was dried at 80 ° C. for 5 minutes, and further dried at 120 ° C. for 5 minutes to obtain a base film (PA1) with an anode catalyst layer in which the catalyst layer was formed on the base film. Similarly, the cathode catalyst layer coating solution (KC) was applied on the base film using a die coater so that the amount of platinum was 0.5 mg / cm ^2, and dried at 80 ° C. for 5 minutes. Furthermore, it dried at 120 degreeC for 5 minute (s), and obtained the base film (PC1) with the cathode catalyst layer in which the catalyst layer was formed on the base film. Next, on both sides of the polymer electrolyte membrane (H20), the base material films with the catalyst layer (PA1) and (PC1) are arranged so that the catalyst layer side is in contact with the electrolyte membrane, and the pressure is 1.5 MPa at 150 ° C. An anode-cathode catalyst layer laminate film in which an anode catalyst layer is laminated on one side of the polymer electrolyte membrane, and a cathode catalyst layer is laminated on the other side (2) Q-1) was formed.

Step (q1-1), Step (q′1-1):
Next, the carbon layer of the laminate (A-1) is arranged so as to be in contact with the cathode catalyst layer of the anode / cathode catalyst layer laminate film (Q1), and the carbon layer of the laminate (A′-1) The membrane electrode assembly (1) which is placed in contact with the anode catalyst layer of the cathode catalyst layer laminated film (Q-1) and heated and pressed at 150 ° C. and 1.5 MPa for 2 minutes to have an electrode area of 25 cm ^2. )

(Evaluation of power generation characteristics)
The membrane / electrode assembly (1) is incorporated into a power generation cell, hydrogen (utilization rate 70%) / air (utilization rate 50%) is supplied under normal pressure, the cell temperature is 80 ° C., and the current density is 0.2 A / The cell voltage at the initial stage of operation at cm ² or 1.2 A / cm ² was measured. However, hydrogen having a dew point of 80 ° C. was supplied to the anode side, and air having a dew point of 80 ° C. was supplied to the cathode side.
Similarly, under a pressure of 75 kPa, dry hydrogen (utilization rate 70%) is supplied to the anode side, dry air (utilization rate 50%) is supplied to the cathode side, and the current density is 0.2 A / cm at a cell temperature of 80 ° C. The cell voltage at the initial stage of operation at ² or 1.2 A / cm ² was measured. Table 1 shows the cell voltage.

(Evaluation of dry and wet repeated resistance)
Membrane electrode assembly 1 was incorporated into a power generation cell, and nitrogen was passed through both electrodes at a pressure of 1 L / min at normal pressure. Nitrogen permeation was measured in a state where dry air and 150% humidified air flow alternately every two minutes and a differential pressure of 20 kPa was periodically applied. Table 1 shows the nitrogen permeation amount after 20000 times.

[Example 2]
Step (a-2) to Step (c-2):
In the same manner as in Step (a-1) to Step (c-1) of Example 1, a laminate (A-1) in which a carbon layer was formed on carbon paper was obtained.

Steps (p-1-2) to (p-3-2):
Using a film in which an ETFE film is laminated on both sides of a polyethylene terephthalate film as a base film, a cathode catalyst layer coating solution (KC) is formed thereon using a die coater so that the platinum amount is 0.35 mg / cm ^2. It was coated, dried at 80 ° C. for 5 minutes, and further dried at 120 ° C. for 5 minutes to obtain a base film (PC2) with a cathode catalyst layer in which the cathode catalyst layer was formed on the base film.
Next, it arrange | positions so that the cathode catalyst layer of the base film (PC2) with a cathode catalyst layer may contact | connect one side of a polymer electrolyte membrane (H25), and it heat-presses at 150 degreeC and the pressure of 1.5 Mpa for 2 minutes, cooling Thereafter, the base film was peeled off to form a cathode catalyst layer laminated film (Q′-1) in which the cathode catalyst layer was laminated on one side of the polymer electrolyte membrane.

Step (d-2):
On the carbon paper (J), a carbon layer coating solution (M1) was applied using a die coater so that the total weight of carbon and ion exchange resin was 0.8 mg / cm ^2. The film was dried at 5 ° C. for 5 minutes and further dried at 120 ° C. for 5 minutes to form a carbon layer having a thickness of 9 μm on the carbon paper.

Step (e-2):
Further, the anode catalyst layer coating solution (KA) was applied on the carbon layer formed in the step (d-2) using a die coater so that the platinum amount was 0.05 mg / cm ^2. The laminate (B-1) having a carbon layer and an anode catalyst layer formed on carbon paper was produced by drying at 120 ° C. for 5 minutes and further drying at 120 ° C. for 5 minutes.

Step (q2-2), (q′2-2):
Next, the carbon layer of the laminate (A-1) is disposed so as to be in contact with the cathode catalyst layer of the cathode catalyst layer laminate film (Q′-1), and the anode catalyst layer of the laminate (B-1) is the cathode. Membrane electrode bonding in which the electrode area is 25 cm ² by placing the catalyst layer laminated film (Q′-1) in contact with the polymer electrolyte membrane and performing a heat press at 150 ° C. and a pressure of 1.5 MPa for 2 minutes. Body (2) was obtained.
The membrane / electrode assembly (2) was evaluated for power generation characteristics and dry / wet repeat resistance. The results are shown in Table 1.

[Example 3]
The polymer electrolyte membrane (H30) was used instead of the polymer electrolyte membrane (H25) of Example 2, and the carbon layer coating solution (M2) was used instead of the carbon layer coating solution (M1). A membrane electrode assembly (3) was obtained in the same manner as Example 2 except for the above.
The membrane / electrode assembly (3) was evaluated for power generation characteristics and dry / wet repeat resistance. The results are shown in Table 1.

[Example 4]
A polymer electrolyte membrane (H20) was used instead of the polymer electrolyte membrane (H25) of Example 2, and the platinum amount of the cathode catalyst layer was changed from 0.35 mg / cm ² to 0.5 mg / cm ^2. In the same manner as in Example 2, a membrane / electrode assembly (4) was obtained.

  The membrane / electrode assembly (4) was evaluated for power generation characteristics and dry / wet repeat resistance. The results are shown in Table 1.

[Example 5]
Step (a-5) to Step (c-5):
In the same manner as in Step (a-1) to Step (c-1) of Example 1, a laminate (A-1) in which a carbon layer was formed on carbon paper was obtained.

Steps (p-1-5) to (p-3-5), (p′-1-5) to (p′-3-5):
The steps (p-1-1) to (p-3-1) and (p′-1-1) of Example 1 except that the polymer electrolyte (E25) was used instead of the polymer electrolyte membrane (H20). ) To (p′-3-1), an anode / cathode catalyst layer laminated film (Q-2) was formed.

Step (q3-5), (q′3-5):
Next, the carbon layer (J-1) is arranged so that the carbon layer of the laminate (A-1) is in contact with the cathode catalyst layer of the anode / cathode catalyst layer laminate film (Q-2). A membrane electrode assembly having an electrode area of 25 cm ² is disposed by contacting the anode catalyst layer of the catalyst layer laminated film (Q-2) and performing a heat press at 150 ° C. and a pressure of 1.5 MPa for 2 minutes. 5) was obtained.

  The membrane / electrode assembly (5) was evaluated for power generation characteristics and dry / wet repeat resistance. The results are shown in Table 1.

[Example 6]
Step (a-6) to Step (c-6):
In the same manner as in Step (a-1) to Step (c-1) of Example 1, a laminate (A-1) in which a carbon layer is formed on carbon paper is obtained.

Step (f-6):
Further, the anode catalyst layer coating solution (KA) is applied on the carbon paper (J) using a die coater so that the platinum amount is 0.05 mg / cm ^2, and dried at 80 ° C. for 5 minutes. Then, it is further dried at 120 ° C. for 5 minutes to produce a laminate (C-1) in which an anode catalyst layer is formed on carbon paper.

Steps (p-1-6) to (p-3-6):
A polymer electrolyte membrane (H20) was obtained in the same manner as in steps (p-1) to (p-3) of Example 2 except that the polymer electrolyte membrane (H20) was used instead of the polymer electrolyte membrane (H25). ) Is formed on one side of the cathode catalyst layer laminated film (Q′-2).

Step (q4-6), (q′4-6):
Next, it arrange | positions so that the carbon layer of laminated body (A-1) may contact the cathode catalyst layer of cathode catalyst layer laminated film (Q'-2), and also the anode catalyst layer of laminated body (C-1). Is placed in contact with the polymer electrolyte membrane of the cathode catalyst layer laminate membrane (Q′-2), and is heated and pressed at 150 ° C. and a pressure of 1.5 MPa for 2 minutes, whereby a membrane electrode having an electrode area of 25 cm ² A joined body (6) is obtained.
The membrane electrode assembly (6) is evaluated for power generation characteristics and dry and wet repeated resistance. The results are shown in Table 1.

[Example 7]
Step (g-7), (g′-7):
A film in which an ETFE film is laminated on both sides of a polyethylene terephthalate film is used as a base film, and a carbon layer coating solution (M1) is formed thereon so that the total weight of carbon and ion-exchange tree is 0.4 mg / cm ^2. The film was coated using a die coater, dried at 80 ° C. for 5 minutes, and further dried at 120 ° C. for 5 minutes to form a carbon layer A having a thickness of 5 μm.

Step (h-7), (h′-7):
On the carbon layer A obtained in the steps (g-7) and (g′-7), the carbon layer B coating solution (M1) is used, and the total weight of the carbon of the carbon layer B and the ion exchange tree is 1. Coating was performed using a die coater so as to be 6 mg / cm ² to form a carbon layer B coating liquid layer.

Step (i-7), (i′-7):
Immediately after forming the carbon layer B coating liquid layer, the carbon layer B coating liquid layer is covered with carbon paper (J ′), and the carbon layer B coating liquid layer is dried in an oven at 80 ° C. for 5 minutes. Further, it was dried in a dryer at 120 ° C. for 5 minutes to form a carbon layer B having a thickness of 20 μm.

Step (j-7), (j′-7):
A laminate (D-) in which the base film is peeled off from the laminate obtained in the steps (i-7) and (i′-7), and the carbon layer A and the carbon layer B are formed on the carbon paper (J ′). 1) and (D′-1) were obtained.

Steps (p-1-7) to (p-3-7), (p′-1-7) to (p′-3-7):
Steps (p-1-1) to (p-3-1), (p) of Example 1 except that the platinum amount of the anode catalyst layer was changed from 0.1 mg / cm ² to 0.05 mg / cm ^2. An anode / cathode catalyst layer laminated film (Q-3) was formed in the same manner as in p′-1-1) to (p′-3-1).

Step (q5), (q′5):
Next, the carbon layer A of the laminate (D-1) obtained in the step (j-7) is disposed so as to be in contact with the cathode catalyst layer of the anode / cathode catalyst layer laminate film (Q-3). The carbon layer A of the laminate (D′-1) obtained in (j′-7) is disposed so as to be in contact with the anode catalyst layer of the anode / cathode catalyst layer laminate film (Q-3). A membrane electrode assembly (7) having an electrode area of 25 cm ² was obtained by heating and pressing at a pressure of 5 MPa for 2 minutes.
The membrane / electrode assembly (7) was evaluated for power generation characteristics and dry and wet repeatability. The results are shown in Table 1.

[Example 8]
Step (g-8) to Step (j-8):
In the same manner as in Step (g-7) to Step (j-7) of Example 7, a laminate (D-1) in which the carbon layer A and the carbon layer B are formed on the carbon paper (J ′) is obtained.

Steps (p-1-8) to (p-3-8):
In the same manner as in Steps (p-1-6) to (p-3-6) of Example 6, a cathode catalyst layer laminated film (Q′−) in which a cathode catalyst layer is laminated on one side of the polymer electrolyte membrane (H20). 2) is formed.

Step (d-8):
Further, on the carbon paper (J ′), the carbon layer coating solution (M1) was applied using a die coater so that the total weight of the carbon and the ion exchange tree was 0.8 mg / cm ² . It is dried at 80 ° C. for 5 minutes and further dried at 120 ° C. for 5 minutes to form a carbon layer having a thickness of 9 μm on the carbon paper.

Step (e-8):
Further, the anode catalyst layer coating solution (KA) was applied onto the carbon layer formed in the step (d-8) using a die coater so that the platinum amount was 0.05 mg / cm ^2. Drying at 5 ° C. for 5 minutes and further drying at 120 ° C. for 5 minutes produce a laminate (B-2) in which a carbon layer and an anode catalyst layer are formed on carbon paper (J ′).

Step (q6-8), (q′6-8):
Next, the carbon layer A of the laminate (D-1) is arranged so as to be in contact with the cathode catalyst layer of the cathode catalyst layer laminate film (Q′-2), and the anode catalyst layer of the laminate (B-2) is arranged. A membrane electrode in which the electrode area is 25 cm ² by placing the cathode catalyst layer laminated film (Q′-2) in contact with the polymer electrolyte membrane and performing a heat press at 150 ° C. and a pressure of 1.5 MPa for 2 minutes. A joined body (8) is obtained.
The membrane electrode assembly (8) is evaluated for power generation characteristics and dry and wet repeatability. The results are shown in Table 1.

[Example 9]
Step (g-9) to Step (j-9):
In the same manner as in Step (g-7) to Step (j-7) of Example 7, a laminate (D-1) in which the carbon layer A and the carbon layer B are formed on the carbon paper (J ′) is obtained.

Steps (p-1-9) to (p-3-9), (p′-1-9) to (p′-3-9):
In the same manner as in Steps (p-1-7) to (p-3-7) and (p′-1-7) to (p′-3-7) of Example 7, Q-3) is formed.

Step (q7-9), (q′7-9):
Next, the carbon layer A of the laminate (D-1) is disposed so as to be in contact with the cathode catalyst layer of the anode / cathode catalyst layer laminate film (Q-3), and the carbon paper (J ′) A membrane electrode in which the electrode area is 25 cm ² by placing it in contact with the anode catalyst layer of the anode-cathode catalyst layer laminate film (Q-3) and performing a heat press at 150 ° C. and a pressure of 1.5 MPa for 2 minutes. A joined body (9) is obtained.
The membrane electrode assembly (9) is evaluated for power generation characteristics and dry and wet repeated resistance. The results are shown in Table 1.

[Example 10]
Process (g-10)-process (j-10):
In the same manner as in Step (g-7) to Step (j-7) of Example 7, a laminate (D-1) in which the carbon layer A and the carbon layer B are formed on the carbon paper (J ′) is obtained.

Steps (p-1-10) to (p-3-10):
In the same manner as in Steps (p-1-6) to (p-3-6) of Example 6, a cathode catalyst layer laminated film (Q′−) in which a cathode catalyst layer is laminated on one side of the polymer electrolyte membrane (H20). 2) is formed.

Step (f-10):
Further, the anode catalyst layer coating solution (KA) was applied onto carbon paper (J ′) using a die coater so that the platinum amount was 0.05 mg / cm ^2, and the coating was performed at 80 ° C. for 5 minutes. It is dried and further dried at 120 ° C. for 5 minutes to produce a laminate (C-2) in which an anode catalyst layer is formed on carbon paper (J ′).

Step (q8-10), (q′8-10):
Next, the carbon layer A of the laminate (D-1) is disposed so as to be in contact with the cathode catalyst layer of the cathode catalyst layer laminate film (Q′-2), and further the anode of the laminate (C-2). The catalyst layer is disposed so as to be in contact with the polymer electrolyte membrane of the cathode catalyst layer laminated film (Q′-2), and is heated and pressed at 150 ° C. and a pressure of 1.5 MPa for 2 minutes, so that the electrode area is 25 cm ^2. A membrane electrode assembly (10) is obtained.
The membrane electrode assembly (10) is evaluated for power generation characteristics and dry and wet repeated resistance. The results are shown in Table 1.

[Example 11]
In the same manner as in Steps (p-1-1) to (p-3-1) and (p′-1-1) to (p′-3-1) in Example 1, the polymer electrolyte membrane (H20) An anode / cathode catalyst layer laminated film (Q-1) having catalyst layers formed on both sides was formed.
Next, carbon paper (J) is arranged on both sides of the anode / cathode catalyst layer laminated film (Q-1) and heated and pressed at 150 ° C. and a pressure of 1.5 MPa for 2 minutes, so that the electrode area is 25 cm ² . A membrane electrode assembly (11) was obtained.
The membrane / electrode assembly (11) was evaluated for power generation characteristics and dry and wet repeatability. The results are shown in Table 1.

[Example 12]
In the same manner as in Steps (p-1-7) to (p-3-7) and (p′-1-7) to (p′-3-7) of Example 7, the polymer electrolyte membrane (H20) An anode / cathode catalyst layer laminate film (Q-3) having catalyst layers laminated on both sides was formed.
Next, carbon paper (J ′) is arranged on both sides of the anode / cathode catalyst layer laminated film (Q-3), and heated and pressed at 150 ° C. and a pressure of 1.5 MPa for 2 minutes, so that the electrode area is 25 cm ^2. A membrane electrode assembly (12) was obtained.
The membrane / electrode assembly (12) was evaluated for power generation characteristics and dry / wet repeat resistance. The results are shown in Table 1.

(Adhesive strength at the membrane / electrode interface)
The cathode catalyst layer of the cathode catalyst layer laminated film (Q′-1) prepared in steps (p-1-2) to (p-3-2) of Example 2 and steps (a-2) to ( c-2) is placed so as to be in contact with the carbon layer of the laminate (A-1) produced in c-2), placed in a press machine heated to 150 ° C. in advance, and hot pressed for 2 minutes at a pressing pressure of 1.5 MPa. A joined body (1) in which the cathode catalyst layer, the carbon layer, and the carbon paper were laminated only on one surface of the polymer electrolyte membrane (H20) was produced.

  The cathode catalyst layer of the cathode catalyst layer laminate film (Q′-2) produced in steps (p-1-8) to (p-3-8) of Example 8, and steps (g-7) to (g) of Example 7 Placed in contact with the carbon layer A of the laminate (D-1) produced in j-7), placed in a press machine heated to 150 ° C. in advance, and hot pressed for 2 minutes at a press pressure of 1.5 MPa. Then, a joined body (2) in which the cathode catalyst layer, the carbon layer A, the carbon layer B, and the carbon paper were laminated only on one surface of the polymer electrolyte membrane (H20) was produced.

  Arrange the cathode catalyst layer of the cathode catalyst layer laminated film (Q′-1) produced in steps (p-1-2) to (p-3-2) of Example 2 so that the carbon paper (J) is in contact with the cathode catalyst layer. , Put in a press machine preheated to 150 ° C., heat-pressed for 2 minutes at a pressing pressure of 1.5 MPa, and a joined body in which a cathode catalyst layer and carbon paper are laminated only on one side of the polymer electrolyte membrane (H20) 3) was produced.

  Arranged so that the cathode catalyst layer of the cathode catalyst layer laminated film (Q′-2) produced in steps (p-1-8) to (p-3-8) of Example 8 is in contact with the carbon paper (J ′). Then, it is put in a press machine heated to 150 ° C. in advance, hot pressed at a pressing pressure of 1.5 MPa for 2 minutes, and a cathode catalyst layer and carbon paper are laminated on only one side of the polymer electrolyte membrane (H20). (4) was produced.

  The gas diffusion layer side of the produced joined bodies (1) to (4) was fixed, the end of the polymer electrolyte membrane was sandwiched between chucks of a tensile tester, and the 90-degree peel strength was measured under the following conditions. The measured value of the joined body (1) is the 90 degree peel strength of the membrane electrode assemblies (1) to (6), and the measured value of the joined body (2) is the membrane electrode assemblies (7) to (10). The measured value of the joined body (3) is the 90 degree peel strength of the membrane electrode assembly (11), and the measured value of the joined body (4) is the 90 degree of the membrane electrode assembly (12). Degree of peel strength. The results are shown in Table 1.

Sample width: 25mm,
Peeling speed: 20 mm / min,
Temperature: 25 ° C.

  The membrane / electrode assembly obtained by the production method of the present invention has high durability and high output voltage in a wide range of current densities, and particularly high durability even when used in an environment where drying and wetting are repeated. Therefore, it is extremely useful for a polymer electrolyte fuel cell used as a power source for moving bodies such as automobiles, a distributed power generation system, a home cogeneration system, and the like.

It is sectional drawing which shows an example of the membrane electrode assembly for polymer electrolyte fuel cells. It is sectional drawing which shows 1 process of the manufacturing method of the membrane electrode assembly for polymer electrolyte fuel cells of this invention. It is sectional drawing which shows 1 process of the manufacturing method of the membrane electrode assembly for polymer electrolyte fuel cells of this invention. It is sectional drawing which shows 1 process of the manufacturing method of the membrane electrode assembly for polymer electrolyte fuel cells of this invention. It is sectional drawing which shows 1 process of the manufacturing method of the membrane electrode assembly for polymer electrolyte fuel cells of this invention. It is sectional drawing which shows 1 process of the manufacturing method of the membrane electrode assembly for polymer electrolyte fuel cells of this invention. It is sectional drawing which shows 1 process of the manufacturing method of the membrane electrode assembly for polymer electrolyte fuel cells of this invention. It is sectional drawing which shows an example of the membrane electrode assembly for polymer electrolyte fuel cells. It is sectional drawing which shows 1 process of the manufacturing method of the membrane electrode assembly for polymer electrolyte fuel cells of this invention. It is sectional drawing which shows 1 process of the manufacturing method of the membrane electrode assembly for polymer electrolyte fuel cells of this invention. It is sectional drawing which shows an example of the membrane electrode assembly for polymer electrolyte fuel cells. It is sectional drawing which shows 1 process of the manufacturing method of the membrane electrode assembly for polymer electrolyte fuel cells of this invention. It is sectional drawing which shows 1 process of the manufacturing method of the membrane electrode assembly for polymer electrolyte fuel cells of this invention. It is sectional drawing which shows 1 process of the manufacturing method of the membrane electrode assembly for polymer electrolyte fuel cells of this invention. It is sectional drawing which shows 1 process of the manufacturing method of the membrane electrode assembly for polymer electrolyte fuel cells of this invention. It is sectional drawing which shows an example of the membrane electrode assembly for polymer electrolyte fuel cells. It is sectional drawing which shows 1 process of the manufacturing method of the membrane electrode assembly for polymer electrolyte fuel cells of this invention. It is sectional drawing which shows 1 process of the manufacturing method of the membrane electrode assembly for polymer electrolyte fuel cells of this invention.

Explanation of symbols

100, 200, 300, 400 Membrane electrode assembly 12 First catalyst layer 14 First carbon layer 14-1 First carbon layer A
14-2 First carbon layer B
16 1st gas diffusion layer 18 1st carbon layer coating liquid layer 120, 320 1st electrode 22 2nd catalyst layer 24 2nd carbon layer 24-1 2nd carbon layer A
24-2 Second carbon layer B
26 Second gas diffusion layer 28 Second carbon layer coating liquid layer 130, 230, 330 Second electrode 160 Laminate (A)
260 Laminate (A ')
360 Laminate (B)
460 Laminate (C)
560 Laminate (D)
660 Laminate (D ')
760 Laminate (E)
40 Solid polymer electrolyte membrane 50 Base film

Claims (12)

A first electrode having a first catalyst layer and a first gas diffusion layer;
A second electrode having a second catalyst layer and a second gas diffusion layer;
A solid polymer electrolyte membrane disposed between the first catalyst layer and the second catalyst layer;
A first carbon layer comprising carbon and an ion exchange resin between the first catalyst layer and the first gas diffusion layer;
A method for producing a membrane electrode assembly for a polymer electrolyte fuel cell comprising:
The manufacturing method of the membrane electrode assembly for polymer electrolyte fuel cells which has the following process (a)-(c), (p), (q1).
(A) A step of forming a first carbon layer coating liquid layer by applying a carbon layer coating liquid containing carbon and an ion exchange resin on a base film.
(B) After covering the first gas diffusion layer on the first carbon layer coating liquid layer formed in step (a), drying the first carbon layer coating liquid layer. Forming the first carbon layer.
(C) The process of peeling a base film from the laminated body which has the said 1st carbon layer and said 1st gas diffusion layer formed at the process (b), and obtaining a laminated body (A).
(P) A step of forming the first catalyst layer on one surface of the solid polymer electrolyte membrane.
(Q1) The first carbon layer of the laminate (A) obtained in step (c) and the first catalyst formed on one surface of the solid polymer electrolyte membrane in step (p) A process of heat bonding so as to contact the layer.   The ion exchange resin contained in the first carbon layer is a fluorine-containing ion exchange resin, and the carbon of the first carbon layer and the fluorine-containing ion exchange resin are in a mass ratio of 1: 0.1 to 1: 5. The method for producing a membrane electrode assembly for a polymer electrolyte fuel cell according to claim 1.   The method for producing a membrane electrode assembly for a polymer electrolyte fuel cell according to claim 1 or 2, wherein the thickness of the first carbon layer is 1 to 60 µm. A second carbon layer containing carbon and an ion exchange resin between the second catalyst layer and the second gas diffusion layer of the second electrode;
The membrane electrode assembly for a polymer electrolyte fuel cell according to any one of claims 1 to 3, further comprising the following steps (a ') to (c'), (p '), and (q'1). Production method.
(A ′) A step of forming a second carbon layer coating liquid layer by applying a carbon layer coating liquid containing carbon and an ion exchange resin on the base film.
(B ′) After covering the second gas diffusion layer on the second carbon layer coating liquid layer formed in the step (a ′), the second carbon layer coating liquid layer is applied. Drying to form the second carbon layer.
(C ′) A step of obtaining a laminate (A ′) by peeling off the base film from the laminate having the second carbon layer and the second gas diffusion layer formed in the step (b ′).
(P ′) A step of forming the second catalyst layer on one surface of the solid polymer electrolyte membrane.
(Q′1) formed on one surface of the solid polymer electrolyte membrane in the step (p ′) and the second carbon layer of the laminate (A ′) obtained in the step (c ′). Heating and joining the second catalyst layer in contact with the second catalyst layer;   The ion exchange resin contained in the second carbon layer is a fluorinated ion exchange resin, and the carbon of the second carbon layer and the fluorinated ion exchange resin are in a mass ratio of 1: 0.1 to 1: 5. The method for producing a membrane electrode assembly for a polymer electrolyte fuel cell according to claim 4, wherein the membrane electrode assembly is 5.   The method for producing a membrane electrode assembly for a polymer electrolyte fuel cell according to claim 4 or 5, wherein the thickness of the second carbon layer is 1 to 60 µm. A first electrode having a first catalyst layer and a first gas diffusion layer;
A second electrode having a second catalyst layer and a second gas diffusion layer;
A solid polymer electrolyte membrane disposed between the first catalyst layer and the second catalyst layer;
A first carbon layer A and a first carbon layer B containing carbon and an ion exchange resin between the first catalyst layer and the first gas diffusion layer;
A method for producing a membrane electrode assembly for a polymer electrolyte fuel cell comprising:
The manufacturing method of the membrane electrode assembly for polymer electrolyte fuel cells which has the following process (g)-(j), (p), (q4).
(G) The process of forming the 1st carbon layer A by apply | coating the coating liquid for carbon layer A containing carbon and an ion exchange resin on a base film, and drying.
(H) On the first carbon layer A formed in step (g), a carbon layer B coating solution containing carbon and an ion exchange resin is applied to form a first carbon layer B coating solution layer. Forming.
(I) After covering the first gas diffusion layer on the first carbon layer B coating liquid layer formed in the step (h), the first carbon layer B coating liquid layer is applied. A step of forming the first carbon layer B by drying.
(J) The substrate film is peeled off from the laminate having the first carbon layer A, the first carbon layer B, and the first gas diffusion layer formed in the step (i), and the laminate (D) Obtaining.
(P) A step of forming the first catalyst layer on one surface of the solid polymer electrolyte membrane.
(Q4) The first carbon layer A of the laminate (D) obtained in step (j) and the first carbon layer formed on one surface of the solid polymer electrolyte membrane in step (p) A process of heat-bonding so as to contact the catalyst layer.   The method for producing a membrane / electrode assembly for a polymer electrolyte fuel cell according to claim 7, wherein the thickness of the first carbon layer A is 0.5 to 20 μm. A membrane for a solid polymer fuel cell having a second carbon layer A and a second carbon layer B containing carbon and an ion exchange resin between the second catalyst layer and the second gas diffusion layer A method for producing an electrode assembly,
The method for producing a membrane / electrode assembly for a polymer electrolyte fuel cell according to claim 7 or 8, further comprising the following steps (g ') to (j'), (p '), and (q4').
(G ′) A step of coating the base film with a coating solution for carbon layer A containing carbon and an ion exchange resin, and drying to form a second carbon layer A.
(H ′) On the second carbon layer A formed in the step (g ′), a carbon layer B coating solution containing carbon and an ion exchange resin is applied to apply the second carbon layer B. Forming a liquid layer;
(I ′) After covering the second gas diffusion layer on the second carbon layer B coating liquid layer formed in the step (h ′), the second carbon layer B coating liquid layer The process of drying 2nd and forming the 2nd carbon layer B.
(J ′) The substrate is peeled off from the laminate having the second carbon layer A, the second carbon layer B, and the second gas diffusion layer formed in step (i ′), and the laminate A step of obtaining (D ′).
(P ′) A step of forming the second catalyst layer on one surface of the solid polymer electrolyte membrane.
(Q4 ′) formed on one surface of the solid polymer electrolyte membrane in the second carbon layer A of the laminate (D ′) obtained in the step (j ′) and in the step (p ′). Heating and joining the second catalyst layer in contact with the second catalyst layer;   The method for producing a membrane electrode assembly for a polymer electrolyte fuel cell according to claim 9, wherein the thickness of the second carbon layer A is 0.5 to 20 μm.   The method for producing a membrane electrode assembly for a polymer electrolyte fuel cell according to any one of claims 1 to 10, wherein the first electrode is a cathode.   The method for producing a membrane electrode assembly for a polymer electrolyte fuel cell according to any one of claims 1 to 11, wherein the carbon is a carbon nanofiber having a fiber diameter of 1 to 1000 nm and a fiber length of 1000 µm or less.

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