JP6468475B2 - Membrane electrode assembly for polymer electrolyte fuel cell and polymer electrolyte fuel cell - Google Patents

Description

  The present invention relates to a membrane electrode assembly for a polymer electrolyte fuel cell and a polymer electrolyte fuel cell.

  In the polymer electrolyte fuel cell, for example, a cell is formed by sandwiching a membrane electrode assembly between two separators, and a plurality of cells are stacked. The membrane / electrode assembly includes an anode and a cathode having a catalyst layer and a gas diffusion layer, and a solid polymer electrolyte membrane disposed between the anode and the cathode.

  As one means for improving the power generation characteristics of a polymer electrolyte fuel cell, it is known to reduce the membrane resistance by thinning the polymer electrolyte membrane. However, when the solid polymer electrolyte membrane is thinned, the mechanical strength of the solid polymer electrolyte membrane is lowered, and as a result, the mechanical strength of the membrane electrode assembly is lowered. Further, since hydrogen gas easily permeates through the solid polymer electrolyte membrane, the amount of hydrogen leak increases, and the power generation efficiency of the solid polymer fuel cell decreases.

The following method has been proposed as a method for increasing the mechanical strength of the membrane electrode assembly.
(1) A method of reinforcing a solid polymer electrolyte membrane and an electrode by providing a porous polytetrafluoroethylene sheet in the solid polymer electrolyte membrane and in an electrode (Patent Document 1).
(2) A method of reinforcing a solid polymer electrolyte membrane by providing a porous sheet having a plurality of through holes in the solid polymer electrolyte membrane (Patent Document 2).

  In the method (1), since the porosity of the porous polytetrafluoroethylene sheet is high (60 to 98%) and the pore diameter is small (0.05 to 5 μm), the membrane resistance by the porous polytetrafluoroethylene sheet is reduced. Is less affected. However, since the porous polytetrafluoroethylene sheet having a high porosity and a small pore diameter does not block the permeation of hydrogen gas, the effect of reducing the amount of hydrogen leak is hardly obtained.

  In the method (2), since the porous sheet blocks the permeation of hydrogen gas, an effect of reducing the amount of hydrogen leak can be expected as compared with the porous polytetrafluoroethylene sheet. However, since the movement of protons is also blocked, the solid polymer electrolyte membrane reinforced with the porous sheet is compared with the solid polymer electrolyte membrane reinforced with the porous sheet. The film resistance in the direction perpendicular to the main surface is increased, and the internal resistance in the case of a membrane electrode assembly is also increased.

Japanese Patent No. 3481010 Japanese Patent No. 4702553

  The present invention has a membrane electrode assembly for a polymer electrolyte fuel cell that has low internal resistance, low hydrogen leakage, and high mechanical strength, and has good power generation characteristics, power generation efficiency and durability. A high polymer electrolyte fuel cell is provided.

The membrane / electrode assembly for a polymer electrolyte fuel cell of the present invention comprises an anode, a cathode, and a solid polymer electrolyte membrane disposed between the anode and the cathode, and the anode has the solid high-molecular electrolyte membrane. A porous sheet having a plurality of through holes in contact with the first surface of the molecular electrolyte membrane, and a catalyst portion containing a catalyst that is filled in the through holes of the porous sheet and contacts the first surface of the solid polymer electrolyte membrane And the cathode has a catalyst part containing a catalyst in contact with the second surface of the solid polymer electrolyte membrane, and the average opening area per one through hole of the porous sheet is 0. 002 to 0.08 mm ² , the aperture ratio of the porous sheet is 30 to 80%, the penetration thickness of the solid polymer electrolyte membrane that penetrates the through holes of the porous sheet is 4 μm or less, Of the solid polymer electrolyte membrane Is (except for the penetration thickness.) Is characterized in that it is a 7～20Myuemu.

The thickness of the porous sheet is preferably 5 to 12 μm.
The porous sheet is preferably made of metal.
The metal is preferably titanium or a titanium alloy.
The polymer electrolyte fuel cell of the present invention comprises the membrane electrode assembly for a polymer electrolyte fuel cell of the present invention.

The membrane / electrode assembly for a polymer electrolyte fuel cell of the present invention has a low internal resistance, a reduced amount of hydrogen leak, and a high mechanical strength.
The polymer electrolyte fuel cell of the present invention has good power generation characteristics and high power generation efficiency and durability.

It is sectional drawing which shows an example of the membrane electrode assembly for polymer electrolyte fuel cells of this invention. It is sectional drawing which shows an example of a porous sheet. It is sectional drawing which shows the other example of a porous sheet. It is sectional drawing which shows the other example of the membrane electrode assembly for polymer electrolyte fuel cells of this invention. It is a front view which shows the pattern of the opening of the porous sheet of an Example.

In this specification, the structural unit represented by the formula (u1) is referred to as a unit (u1). The structural units represented by other formulas are also described in the same manner.
Moreover, the monomer represented by the formula (m1) is referred to as a monomer (m1). The same applies to monomers represented by other formulas.

The following definitions of terms apply throughout this specification and the claims.
“Structural unit” means a unit derived from a monomer formed by polymerization of the monomer. The structural unit may be a unit directly formed by a polymerization reaction of monomers, or may be a unit in which a part of the unit is converted into another structure by treating the polymer.
“Monomer” means a compound having a polymerization-reactive carbon-carbon double bond.
The “cation exchange group” means a group in which a part of the cation contained in the group can be exchanged with another cation.
The “precursor group” means a group that can be converted into a cation exchange group by a known treatment such as hydrolysis treatment or acidification treatment.

<Membrane electrode assembly>
FIG. 1 is a cross-sectional view showing an example of a membrane electrode assembly for a polymer electrolyte fuel cell of the present invention (hereinafter referred to as a membrane electrode assembly).
The membrane electrode assembly 10 includes an anode 20, a cathode 30, and a solid polymer electrolyte membrane 40 disposed between the anode 20 and the cathode 30.

(anode)
The anode 20 is in contact with the first surface of the solid polymer electrolyte membrane 40, the porous sheet 22 having a plurality of through holes 22 a, and the through holes 22 a of the porous sheet 22 filled with the first sheet of the solid polymer electrolyte membrane 40. And a gas diffusion layer 26 in contact with the catalyst portion 24.

Perforated sheet:
The porous sheet 22 has a plurality of through holes 22a penetrating in the thickness direction.
The opening shape of the through hole 22a is not particularly limited, and examples thereof include a circle, an ellipse, a triangle, a regular square, a rectangle, a trapezoid, a hexagon, a star, a cross, and other arbitrary shapes.

Examples of the porous sheet 22 include metal foil and plastic film.
The material of the porous sheet 22 is preferably a metal because it has high mechanical strength and can easily form the through-holes 22a, that is, easily mass-produces and can reduce the cost.

  Examples of the metal include aluminum, nickel, titanium, tantalum, vanadium, molybdenum, and alloys containing at least one of them. From the viewpoint of cost, mechanical strength, and corrosion resistance, titanium, titanium alloy, and stainless steel are included. In view of the fact that iron that accelerates the deterioration of the solid polymer electrolyte membrane 40 is not included, titanium and a titanium alloy are more preferable.

  Examples of the plastic include polytetrafluoroethylene (hereinafter referred to as PTFE), tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-perfluoroalkoxyethylene copolymer, polysulfone, polyphenylene sulfide (hereinafter referred to as PPS). .), Polyarylate, polyether sulfone, polyether ether ketone, polyether imide, polyether amide, polypropylene, polyethylene and the like.

  The porous sheet 22 may have a through hole 22a formed on the entire surface, or may have a region where the through hole 22a is formed and a region where the through hole 22a is not formed. For example, when the power generation function is not required at the peripheral portion of the membrane electrode assembly 10, the region corresponding to the peripheral portion may be a region where the through hole 22a is not formed. Hereinafter, the average opening area per through hole 22a of the porous sheet 22 and the opening ratio of the porous sheet 22 are values obtained in the region where the through hole 22a is formed.

Average open area per one through-hole 22a of the porous sheet 22 is 0.002～0.08Mm ^2, preferably 0.004～0.05Mm ^2, more preferably 0.01～0.03Mm ² . If the average opening area is 0.002 mm ² or more, it is easy to form the through holes 22a, that is, the porous sheet 22 is easy to manufacture. If the average opening area is 0.08 mm ² or less, the membrane resistance in the solid polymer electrolyte membrane 40 can be kept low for the following reasons.

As shown in FIG. 2 and FIG. 3, when compared with the same opening ratio (for example, 50%), one of the through holes 22a is larger than when the average opening area per one of the through holes 22a is large (FIG. 3). The smaller the average opening area (FIG. 2), the smaller the area of the porous sheet 22 body adjacent to the through hole 22a. Protons generated from the oxidation reaction of hydrogen in the catalyst portion 24 of the anode 20 (that is, the through holes 22a) move toward the cathode 30 while diffusing in the solid polymer electrolyte membrane 40, and are thus shielded by the porous sheet 22 body. Protons can also move in the part of the solid polymer electrolyte membrane 40. Therefore, the membrane resistance in the solid polymer electrolyte membrane 40 is reduced.
On the other hand, when the average opening area per one through hole 22a is large, that is, when the area of the porous sheet 22 main body adjacent to the through hole 22a is also large, the portion shielded by the porous sheet 22 main body adjacent to the through hole 22a Protons cannot sufficiently diffuse throughout the solid polymer electrolyte membrane 40. That is, protons hardly move in the portion of the solid polymer electrolyte membrane 40 that is shielded by the main body of the porous sheet 22 adjacent to the through hole 22a. Therefore, the membrane resistance in the solid polymer electrolyte membrane 40 becomes relatively large.

  The average opening area per one through hole 22a of the porous sheet 22 is the area of the opening on the side in contact with the first surface of the solid polymer electrolyte membrane 40 for each of the 20 randomly selected through holes 22a. Obtained and averaged.

  The aperture ratio of the porous sheet 22 is 30 to 80%, preferably 50 to 80%, and more preferably 50 to 67%. If the aperture ratio is 30% or more, the internal resistance can be kept low. If the aperture ratio is 80% or less, the amount of hydrogen leak can be suppressed, and the mechanical strength of the membrane electrode assembly 10 can be increased.

The aperture ratio of the porous sheet 22 is determined as follows.
For example, when 5000 through holes having an average opening area of 0.01 mm ² are opened in a 10 mm square, the opening ratio is 50%. Thus, the aperture ratio of the perforated sheet is obtained by multiplying the average aperture area of the through holes opened in a region of a predetermined size by the number of the through holes, and the total aperture area in that region is the total area of the entire region. Divide by area.

  The thickness t of the porous sheet 22 is preferably 5 to 12 μm, more preferably 7 to 11 μm, and still more preferably 8 to 10 μm. If the thickness t of the porous sheet 22 is 5 μm or more, it is easy to manufacture the porous sheet 22. Moreover, the mechanical strength of the membrane electrode assembly 10 can be increased. If the thickness t of the porous sheet 22 is 12 μm or less, the internal resistance can be kept low.

  As a manufacturing method of the porous sheet 22, a method of forming the through-hole 22a by etching; a method of mechanically punching the non-porous sheet using a punching die; a through-hole 22a using a laser beam with respect to the non-porous sheet The method of forming; The method etc. which form the through-hole 22a using a drill with respect to a non-porous sheet | seat etc. are mentioned. In the mechanical punching method, a punching die capable of forming several hundred to several tens of thousands of holes at a time may be used, and several dozen to several thousand non-porous sheets may be stacked. In the method using a drill, a multi-axis NC drill machine may be used, and several dozen to several thousand non-porous sheets may be stacked. Moreover, you may form a porous sheet by pressing an expanded metal.

Catalyst part:
The catalyst part 24 includes a filling part 24 a filled in the through holes 22 a of the porous sheet 22 and a layered part 24 b spreading on the surface of the porous sheet 22 opposite to the solid polymer electrolyte membrane 40.
As shown in FIG. 4, the catalyst part 24 may be composed of only a filling part 24 a filled in the through hole 22 a of the porous sheet 22. However, from the viewpoint of joining with the gas diffusion layer 26, the catalyst part 24 preferably has a layered part 24b as shown in FIG.

The catalyst part 24 is a layer containing a catalyst and, if necessary, an ion exchange resin described later.
The catalyst is not particularly limited as long as it promotes the oxidation-reduction reaction in the fuel cell, and a catalyst containing platinum is preferable, and a supported catalyst in which platinum or a platinum alloy is supported on a carbon support is particularly preferable.

Examples of the carbon carrier include activated carbon and carbon black.
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, An alloy of platinum and one or more metals selected from the group consisting of tin and platinum is preferable.
The supported amount of platinum or platinum alloy is preferably 10 to 70% by mass in the supported catalyst (100% by mass).

The amount of platinum contained in the catalyst portion 24 is preferably 0.01 to 1.0 mg / cm ² from the viewpoint of the optimum thickness for efficiently performing the electrode reaction, and from the viewpoint of the balance between the cost and performance of the raw material. 0.02-0.1 mg / cm ² is more preferable.

Gas diffusion layer:
The gas diffusion layer 26 is a layer made of a gas diffusing substrate such as carbon paper, carbon cloth, or carbon felt.

  The surface of the gas diffusion layer 26 may be subjected to water repellent treatment with a solution or dispersion containing a water repellent fluoropolymer. The surface of the gas diffusion layer 26 may be subjected to a water repellent treatment with a dispersion containing a water repellent fluoropolymer and conductive carbon in order to prevent water such as generated water from staying.

Examples of the water-repellent fluorine-containing polymer include PTFE. Examples of the conductive carbon include carbon black.
The water-repellent surface of the gas diffusion layer 26 is in contact with the catalyst unit 24 or a carbon layer described later.

Carbon layer:
The anode 20 may have a carbon layer (not shown) between the catalyst unit 24 and the gas diffusion layer 26. By disposing the carbon layer, the gas diffusibility on the surface of the catalyst portion 24 is improved, and the output voltage of the polymer electrolyte fuel cell is greatly improved.

The carbon layer is a layer containing carbon (carbon powder, carbon nanofiber, etc.) and a fluoropolymer.
As carbon, carbon nanofibers having a fiber diameter of 1 to 1000 nm and a fiber length of 1000 μm or less are preferable.
PTFE etc. are mentioned as a fluorine-type polymer.

(Cathode)
The cathode 30 includes a layered catalyst layer 34 (catalyst portion) spreading on the second surface of the solid polymer electrolyte membrane 40 and a gas diffusion layer 36 in contact with the catalyst layer 34.

Catalyst layer:
The catalyst layer 34 is a layer containing a catalyst and, if necessary, an ion exchange resin described later.
Examples of the catalyst include the same ones used for the catalyst portion 24 of the anode 20.
The catalyst layer 34 may be the same as or different from the catalyst portion 24 of the anode 20 in terms of components, composition, and the like.

Gas diffusion layer:
Examples of the gas diffusion layer 36 include the same as the gas diffusion layer 26 of the anode 20.
The surface of the gas diffusion layer 36 is preferably subjected to a water repellent treatment with a solution or dispersion containing a water repellent fluoropolymer. By performing the water repellent treatment, it is difficult for water generated in the catalyst layer 34 of the cathode 30 to block the pores of the gas diffusion layer 36, and a decrease in gas diffusibility is suppressed. The surface of the gas diffusion layer 36 is more preferably water-repellent treated with a dispersion containing a water-repellent fluoropolymer and conductive carbon from the viewpoint of conductivity of the membrane electrode assembly 10.

Carbon layer:
The cathode 30 may have a carbon layer (not shown) between the catalyst layer 34 and the gas diffusion layer 36. By disposing the carbon layer, the gas diffusibility on the surface of the catalyst layer 34 is improved, and the output voltage of the polymer electrolyte fuel cell is greatly improved.
Examples of the carbon layer include the same carbon layer as that of the anode 20.

(Solid polymer electrolyte membrane)
The solid polymer electrolyte membrane 40 includes an ion exchange resin described later. The solid polymer electrolyte membrane 40 may have a multilayer structure in which a plurality of ion exchange resin membranes are joined.

The solid polymer electrolyte membrane 40 may contain one or more atoms selected from the group consisting of cerium and manganese in order to improve durability. Cerium and manganese decompose hydrogen peroxide, which is a causative substance that causes deterioration of the solid polymer electrolyte membrane 40. Cerium and manganese are preferably present in the solid polymer electrolyte membrane 40 as ions, and may be present in any state in the solid polymer electrolyte membrane 40 as long as they are present as ions.
The solid polymer electrolyte membrane 40 may contain silica and heteropolyacid (zirconium phosphate, phosphomolybdic acid, phosphotungstic acid, etc.) as a water retention agent for preventing drying.

A part of the solid polymer electrolyte membrane 40 may enter the through hole 22 a of the porous sheet 22.
The penetration thickness T + of the solid polymer electrolyte membrane 40 penetrating into the through-hole 22a of the porous sheet 22 is 4 μm or less, preferably 3 μm or less, particularly preferably 2 μm or less. If the penetration thickness T + is 4 μm or less, the proton migration distance in the solid polymer electrolyte membrane 40 is shortened, so that the membrane resistance can be kept low.

  The penetration thickness T + is the maximum thickness among ten randomly selected through-holes 22a obtained by measuring the thickness of the solid polymer electrolyte membrane 40 into which the ion exchange resin has penetrated.

  The thickness T of the solid polymer electrolyte membrane 40 (excluding the penetration thickness T +) is 7 to 20 μm, more preferably 8 to 17 μm, and even more preferably 9 to 12 μm. If the thickness T of the solid polymer electrolyte membrane 40 is 7 μm or more, the mechanical strength can be increased. If the thickness T of the solid polymer electrolyte membrane 40 is 20 μm or less, the membrane resistance can be kept low.

(Sub gasket)
The membrane electrode assembly 10 may have two frame-shaped subgaskets (not shown) arranged so as to sandwich the solid polymer electrolyte membrane 40 at the peripheral edge of the membrane electrode assembly 10.

(Other aspects)
The membrane / electrode assembly of the present invention comprises an anode, a cathode, and a solid polymer electrolyte membrane disposed between the anode and the cathode, and the anode is on the first surface of the solid polymer electrolyte membrane. A porous sheet that is in contact with the catalyst, and a catalyst part that is filled in a through-hole of the porous sheet and is in contact with the first surface of the solid polymer electrolyte membrane, wherein the cathode is in contact with the second surface of the solid polymer electrolyte membrane. Having an average opening area per one through hole of the porous sheet, the opening ratio of the porous sheet is a specific range, the penetration thickness of the solid polymer electrolyte membrane entering the through hole is a specific range, The membrane electrode assembly 10 in the illustrated example is not limited as long as the thickness is within a specific range of the solid polymer electrolyte membrane.

(Method for producing membrane electrode assembly)
As a manufacturing method of the membrane electrode assembly 10, the method which has the following process (a)-(f) is mentioned, for example. In addition, the manufacturing method of the membrane electrode assembly 10 is not limited to the following method.
(A) A step of forming the solid polymer electrolyte membrane 40.
(B) A step of bonding the porous sheet 22 to the first surface of the solid polymer electrolyte membrane 40.
(C) A step of forming the catalyst layer 34 on the surface of the carrier film.
(D) A step of transferring the catalyst layer 34 to the second surface of the solid polymer electrolyte membrane 40.
(E) The catalyst portion forming paste is applied to the surface of the porous sheet 22 bonded to the solid polymer electrolyte membrane 40 to form the catalyst portion 24 to obtain a membrane catalyst portion assembly.
(F) A step of joining the gas diffusing base material to both surfaces of the membrane catalyst assembly to obtain the membrane electrode assembly 10.

Step (a):
The solid polymer electrolyte membrane 40 is formed by applying an ion exchange resin liquid to the surface of the carrier film and drying it.
The ion exchange resin liquid is, for example, a liquid in which an ion exchange resin is dispersed or dissolved in a medium containing alcohol and water.
Examples of the carrier film include an ethylene-tetrafluoroethylene (hereinafter referred to as ETFE) film and an olefin resin film.

  In order to stabilize the solid polymer electrolyte membrane 40, it is preferable to perform a heat treatment. The temperature of the heat treatment is preferably 130 to 200 ° C., although it depends on the type of ion exchange resin. When the temperature of the heat treatment is 130 ° C. or higher, the ion exchange resin does not excessively contain water. When the temperature of the heat treatment is 200 ° C. or lower, thermal decomposition of the cation exchange group is suppressed, and a decrease in proton conductivity of the solid polymer electrolyte membrane 40 is suppressed.

Step (b):
The porous sheet 22 is disposed on the first surface of the solid polymer electrolyte membrane 40 and bonded by hot pressing or the like.

Step (c):
The catalyst layer 34 is formed by applying the catalyst layer forming paste to the surface of the carrier film and drying it.
The catalyst layer forming paste is a liquid in which an ion exchange resin and a catalyst are dispersed in a dispersion medium. The paste for forming a catalyst layer can be prepared, for example, by mixing an ion exchange resin liquid and a catalyst or a catalyst dispersion.

Step (d):
The carrier film is peeled off from the solid polymer electrolyte membrane 40, the catalyst layer 34 with a carrier film is disposed on the second surface of the solid polymer electrolyte membrane 40, and the catalyst layer 34 is transferred by hot pressing or the like.

Step (e):
The catalyst part forming paste is applied to the surface of the porous sheet 22 joined to the solid polymer electrolyte membrane 40 and dried to form the catalyst part 24, thereby obtaining a membrane catalyst part assembly.
The catalyst portion forming paste is a liquid in which an ion exchange resin and a catalyst are dispersed in a dispersion medium. The paste for forming a catalyst layer can be prepared, for example, by mixing an ion exchange resin liquid and a catalyst or a catalyst dispersion.

Step (f):
A gas diffusing substrate is bonded to both surfaces of the membrane catalyst assembly by hot pressing or the like to obtain a membrane electrode assembly 10.

(Function and effect)
In the membrane electrode assembly 10 described above, the porous sheet 22 is provided not on the solid polymer electrolyte membrane 40 but on the surface of the solid polymer electrolyte membrane 40, and in the through holes 22 a of the porous sheet 22, the solid The catalyst portion 24 is filled without causing the polymer electrolyte membrane 40 to penetrate as much as possible. Therefore, compared to the case where a porous sheet is provided in a conventional solid polymer electrolyte membrane and the solid polymer electrolyte membrane is filled in the through holes, the movement distance of protons generated from the catalyst portion 24 in the solid polymer electrolyte membrane 40 is smaller. Since it becomes shorter, the film resistance (internal resistance) can be kept low.
Further, since the average opening area per through hole 22a of the porous sheet 22 and the opening ratio of the porous sheet 22 are in a specific range, the internal resistance is further reduced, the amount of hydrogen leak is suppressed, and the mechanical strength is reduced. Is expensive.
Moreover, since the thickness of the solid polymer electrolyte membrane 40 is in a specific range, the internal resistance is further reduced and the mechanical strength is high.

In the membrane electrode assembly 10, the porous sheet 22 is disposed on the first surface (anode side) of the solid polymer electrolyte membrane 40, and the porous sheet 22 is disposed on the second surface (cathode side) of the solid polymer electrolyte membrane 40. The reason for not arranging is as follows.
In the electrode on the side where the porous sheet is disposed, the area of the catalyst portion in contact with the solid polymer electrolyte membrane is reduced, and the electrode reaction is delayed correspondingly. However, since the anode electrode reaction is sufficiently faster than the cathode electrode reaction, that is, the cathode electrode reaction is rate-determined in the whole membrane electrode assembly, the porous sheet is formed on the first surface of the solid polymer electrolyte membrane. Even if it is arranged on the (anode side) and the electrode reaction at the anode is a little slow, the influence on the power generation is small, regardless of the fact that the electrode reaction at the cathode is rate limiting.

(Ion exchange resin)
The ion exchange resin is a fluorine-containing polymer having a cation exchange group.
As the cation exchange group, there are an acid form in which the cation is H ⁺ and a salt form in which the cation is a metal ion, an ammonium ion or the like. In the case of a solid polymer electrolyte membrane or a catalyst part of a membrane electrode assembly, a fluorine-containing ion exchange resin having an acid type cation exchange group is usually used.

The cation exchange _{^{groups, -SO 3 - Z +, -SO}} 2 N - (Z +) -, - SO 2 C - (Z +) <, - P (O) (O - Z +) 2, - C (O) O ^- Z ⁺ ,> C = N ^- Z ⁺ (where Z ⁺ is H ⁺ , a monovalent metal ion, or ammonium in which one or more hydrogen atoms may be substituted with a hydrocarbon group) . an ion), and the like, in the case of using a fluorine-containing ion exchange resin in the solid polymer electrolyte membrane and the catalyst of the membrane electrode _{^{assembly, -SO 3 - H +, -SO}} 2 N - (H +) _{^{-, - SO 2 C - (}} H +) < is _{^{preferable, -SO 3 - H +, -SO}} 2 N - (+ H) - are more preferred, _-SO ³ - ^{H +} is particularly preferred. A part of Z ⁺ of the cation exchange group may be substituted with a divalent or higher valent metal ion.

The fluorine-containing ion exchange resin is preferably a perfluorocarbon polymer having a cation exchange group (which may have an etheric oxygen atom) from the viewpoint of durability.
Examples of the fluorine-containing ion exchange resin include a polymer (H1) having a unit (u1) described later, a polymer (H2) having a unit (u2) described later, a polymer (H3) having a unit (u3) described later, and a unit described later. Polymer (H4) having (u4), polymer (H5) having unit (u5) to be described later, polymer (H6) having unit (u6) to be described later (hereinafter referred to as polymers (H1) to (H6), Polymer (H).).

(Polymer (H1))
The polymer (H1) is a fluorine-containing polymer having the unit (u1) (except for the polymers (H2) to (H6)).

Q ¹ is a single bond or a perfluoroalkylene group which may have an etheric oxygen atom, Y ¹ is a fluorine atom or a monovalent perfluoro organic group, and s is 0 or 1 R ^f1 is a perfluoroalkyl group which may have an etheric oxygen atom, X ¹ is an oxygen atom, a nitrogen atom or a carbon atom, and a is a case where X ¹ is an oxygen atom Is 0 when X ¹ is a nitrogen atom, 2 when X ¹ is a carbon atom, and Z ⁺ is H ⁺ , a monovalent metal ion, or one or more hydrogen atoms are a hydrocarbon group An ammonium ion which may be substituted. A single bond means that the carbon atom of CFY ¹ and the sulfur atom of SO ₂ are directly bonded. An organic group means a group containing one or more carbon atoms.

Unit (u1):
When the perfluoroalkylene group of Q ¹ has an etheric oxygen atom, the oxygen atom may be one or may be two 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 may be linear or branched.
1-6 are preferable and, as for carbon number of a perfluoroalkylene group, 1-4 are more preferable. If carbon number is 6 or less, the fall of the ion exchange capacity of a polymer (H1) will be suppressed, and the fall of proton conductivity will be suppressed.

The perfluoroalkyl group for R ^f1 may be linear or branched, and is preferably linear.
1-6 are preferable and, as for carbon number of a perfluoroalkyl group, 1-4 are more preferable. As the perfluoroalkyl group, a perfluoromethyl group, a perfluoroethyl group and the like are preferable.

The _{^{Z +, -SO 3 - - -SO}} 2 X 1 (SO 2 R f1) a Z +, -SO 2 N (SO 2 R f1) - Z +, or ^{_{-SO 2 C (SO 2 R f1}} ) ₂ ^- Z ⁺ .
Y ¹ is preferably a fluorine atom or a trifluoromethyl group.

  As the unit (u1), units (u1-1) to (u1-4) are preferable from the viewpoint of easy production of the polymer (H1) and easy industrial implementation.

Other units:
The polymer (H1) may further have a structural unit (hereinafter also referred to as another unit) based on another monomer described later. What is necessary is just to adjust suitably the ratio of another unit so that the ion exchange capacity of a polymer (H1) may become the below-mentioned preferable range.
As other units, from the viewpoint of mechanical strength and chemical durability, a structural unit based on a perfluoromonomer is preferable, and a structural unit based on tetrafluoroethylene (hereinafter referred to as TFE) is more preferable.

The polymer (H1) may have one unit (u1) and one other unit, or two or more units.
The polymer (H1) is preferably a perfluorocarbon polymer from the viewpoint of chemical durability.

  The ion exchange capacity of the polymer (H1) is preferably 0.5 to 1.8 meq / g dry resin, more preferably 0.9 to 1.5 meq / g dry resin. If the ion exchange capacity is 0.5 meq / g dry resin or more, proton conductivity is increased, so that sufficient battery output can be obtained. If the ion exchange capacity is 1.8 meq / g dry resin or less, synthesis of a polymer having a high molecular weight is easy, and the polymer (H1) does not swell excessively with water, so that the mechanical strength can be maintained. .

(Polymer (H2))
The polymer (H2) is a fluorine-containing polymer having the unit (u2) (except for the polymers (H3) to (H6)).

However, Q ²¹ is an etheric good perfluoroalkylene group which may have an oxygen atom, Q ²² is a single bond, or which may have an etheric oxygen atom perfluoroalkylene group, Y ² is a fluorine atom or a monovalent perfluoro organic group, t is 0 or 1, R ^f2 is a perfluoroalkyl group optionally having an etheric oxygen atom, and X ² is , An oxygen atom, a nitrogen atom or a carbon atom, b is 0 when X ² is an oxygen atom, 1 when X ² is a nitrogen atom, ² when X ² is a carbon atom, and Z ⁺ Is H ⁺ , a monovalent metal ion, or an ammonium ion in which one or more hydrogen atoms may be substituted with a hydrocarbon group. The single bond means that the carbon atom of CY ² and the sulfur atom of SO ₂ are directly bonded. An organic group means a group containing one or more carbon atoms.

Unit (u2):
When the perfluoroalkylene group of Q ²¹ and Q ²² has an etheric oxygen atom, the oxygen atom may be one or two 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 may be linear or branched, and is preferably linear.
1-6 are preferable and, as for carbon number of a perfluoroalkylene group, 1-4 are more preferable. If the number of carbon atoms is 6 or less, the boiling point of the raw fluorine-containing monomer is lowered, and distillation purification becomes easy. Moreover, if carbon number is 6 or less, the increase in the ion exchange capacity of a polymer (H2) will be suppressed, and the proton conductivity fall will be suppressed.

Q ²² is preferably a C 1-6 perfluoroalkylene group which may have an etheric oxygen atom. When Q ²² is a C 1-6 perfluoroalkylene group which may have an etheric oxygen atom, the polymer electrolyte fuel cell was operated over a longer period than when Q ²² is a single bond. In particular, the stability of the power generation performance is excellent.
At least one of Q ²¹ and Q ²² is preferably a C 1-6 perfluoroalkylene group having an etheric oxygen atom. Since a fluorine-containing monomer having a C 1-6 perfluoroalkylene group having an etheric oxygen atom can be synthesized without undergoing a fluorination reaction with a fluorine gas, the yield is good and the production is easy.

The perfluoroalkyl group for R ^f2 may be linear or branched, and is preferably linear.
1-6 are preferable and, as for carbon number of a perfluoroalkyl group, 1-4 are more preferable. As the perfluoroalkyl group, a perfluoromethyl group, a perfluoroethyl group and the like are preferable.
When the unit (u2) has two or more R ^{f2 s} , R ^f2 may be the same group or different groups.

The _{^{Z +, -SO 3 - - -SO}} 2 X 2 (SO 2 R f2) b Z +, -SO 2 N (SO 2 R f2) - Z +, or ^{_{-SO 2 C (SO 2 R f2}} ) ₂ ^- Z ⁺ .
Y ² is preferably a fluorine atom or a linear perfluoroalkyl group having 1 to 6 carbon atoms which may have an etheric oxygen atom.

  As the unit (u2), units (u2-1) to (u2-3) are preferable from the viewpoint of easy production of the polymer (H2) and easy industrial implementation.

Other units:
The polymer (H2) may further have structural units based on other monomers described later. Moreover, you may have the said unit (u1). What is necessary is just to adjust suitably the ratio of another unit so that the ion exchange capacity of a polymer (H2) may become the below-mentioned preferable range.
The other unit is preferably a structural unit based on a perfluoromonomer, more preferably a structural unit based on TFE, from the viewpoint of mechanical strength and chemical durability.

The polymer (H2) may have one each of the unit (u2) and other units, or may have two or more of each.
The polymer (H2) is preferably a perfluorocarbon polymer from the viewpoint of chemical durability.

  The ion exchange capacity of the polymer (H2) is preferably 0.5 to 2.8 meq / g dry resin, more preferably 0.9 to 2.2 meq / g dry resin. If the ion exchange capacity is 0.5 meq / g dry resin or more, proton conductivity is increased, so that sufficient battery output can be obtained. If the ion exchange capacity is 2.8 meq / g dry resin or less, it is easy to synthesize a polymer having a high molecular weight, and the polymer (H2) does not swell excessively with water, so that the mechanical strength can be maintained. .

(Polymer (H3))
The polymer (H3) is a fluorine-containing polymer having the unit (u3) (except for the polymers (H4) to (H6)).

However, Q ³ is a single bond or a perfluoroalkylene group which may have an etheric oxygen atom, Y ³ is a fluorine atom or a monovalent perfluoroorganic group, and u is 0 or 1 R ^f3 is a C 1-10 perfluoroalkyl group which may have an etheric oxygen atom, X ³ is an oxygen atom or a nitrogen atom, c is an oxygen atom of X ³ 0 in the case of an atom, 1 in the case of X ³ being a nitrogen atom, d is an integer of 1 to 4, Z ⁺ is H ⁺ , a monovalent metal ion, or one or more hydrogen atoms are carbonized An ammonium ion which may be substituted with a hydrogen group. A single bond means that the carbon atom of CFY ³ and the sulfur atom of SO ₂ are directly bonded. An organic group means a group containing one or more carbon atoms.

Unit (u3):
When the perfluoroalkylene group of Q ³ has an etheric oxygen atom, the oxygen atom may be one or two 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 may be linear or branched.
1-10 are preferable, as for carbon number of a perfluoroalkylene group, 1-6 are more preferable, and 1-4 are more preferable. If carbon number is 10 or less, the fall of the ion exchange capacity of a polymer (H3) will be suppressed, and the fall of proton conductivity will be suppressed.

The perfluoroalkyl group for R ^f3 may be linear or branched, and is preferably linear.
1-6 are preferable and, as for carbon number of a perfluoroalkyl group, 1-4 are more preferable. As the perfluoroalkyl group, a perfluoromethyl group, a perfluoroethyl group and the like are preferable.

_{^{-SO 2 X 3 (SO 2 R}} f3) c - The _{^{Z +, -SO 3 - Z +}} , -SO 2 N (SO 2 R f3) - Z +, or ^{_{-SO 2 C (SO 2 R f3}} ) ₂ ^- Z ⁺ .
Y ³ is preferably a fluorine atom or a trifluoromethyl group.
d is particularly preferably 2 because the synthesis of the monomer (m3) is easy and a polymer (H3) having a high ion exchange capacity can be obtained.

  As the unit (u3), units (u3-1) to (u3-4) are preferable from the viewpoint of easy production of the polymer (H3) and easy industrial implementation.

Other units:
The polymer (H3) may further have a structural unit based on another monomer described later. Moreover, you may have the said unit (u1) and / or a unit (u2). What is necessary is just to adjust suitably the ratio of another unit so that the ion exchange capacity of a polymer (H3) may become the below-mentioned preferable range.
The other unit is preferably a structural unit based on a perfluoromonomer, more preferably a structural unit based on TFE, from the viewpoint of mechanical strength and chemical durability.

The polymer (H3) may have one unit (u3) and another unit, or two or more units.
The polymer (H3) is preferably a perfluorocarbon polymer from the viewpoint of chemical durability.

  The ion exchange capacity of the polymer (H3) is preferably 0.5 to 2.8 meq / g dry resin, more preferably 0.9 to 2.2 meq / g dry resin. If the ion exchange capacity is 0.5 meq / g dry resin or more, proton conductivity is increased, so that sufficient battery output can be obtained. When the ion exchange capacity is 2.8 meq / g dry resin or less, synthesis of a polymer having a high molecular weight is easy, and the polymer (H3) does not swell excessively with water, so that the mechanical strength can be maintained. .

(Polymer (H4))
The polymer (H4) is a fluorine-containing polymer having the unit (u4) (except for the polymers (H5) to (H6)).

However, R ¹¹ is a divalent perfluoro organic group which may have an etheric oxygen atom, and R ¹² , R ¹³ , R ¹⁵ and R ¹⁶ each independently have an etheric oxygen atom. R ¹⁴ may be a monovalent perfluoro organic group which may have an etheric oxygen atom, a fluorine atom, or —R ¹¹ (SO ₂ X ⁴ ( SO ₂ R ^f4) _e) ^- a Z ^{+ group, R f4} is a perfluoroalkyl group which may have an etheric oxygen atom, ^{X 4} is an oxygen atom, a nitrogen atom or a carbon atom, e is 0 when X ⁴ is an oxygen atom, 1 when X ⁴ is a nitrogen atom, 2 when X ⁴ is a carbon atom, and Z ⁺ is H ⁺ , a monovalent metal ion, or One or more hydrogen atoms are Be conversion is an ammonium ion. An organic group means a group containing one or more carbon atoms.

Unit (u4):
The divalent perfluoro organic group for R ¹¹ is preferably a perfluoroalkylene group. When the perfluoroalkylene group has an etheric oxygen atom, the oxygen atom may be one or may be two or more. The oxygen atom may be inserted between the carbon-carbon bonds of the perfluoroalkylene group or may be inserted at the carbon atom bond terminal. The perfluoroalkylene group may be linear or branched, and is preferably linear.

As the monovalent perfluoro organic group for R ¹² , R ¹³ , R ¹⁵ , and R ¹⁶ , a perfluoroalkyl group is preferable. From the viewpoint of high polymerization reactivity, at least one of R ¹⁵ and R ¹⁶ is preferably a fluorine atom, and more preferably both are fluorine atoms.

The monovalent perfluoro organic group for R ¹⁴ is preferably a perfluoroalkyl group. When the perfluoroalkyl group has an etheric oxygen atom, the oxygen atom may be one or two or more. The oxygen atom may be inserted between the carbon-carbon bonds of the perfluoroalkyl group or may be inserted at the carbon atom bond terminal. The perfluoroalkyl group may be linear or branched, and is preferably linear. When the unit (u4) has two R ^{11 s} , R ¹¹ may be the same group or different groups.

1-8 are preferable and, as for carbon number of the perfluoroalkyl group of ^Rf4 , 1-6 are more preferable. In the case of having two or more R ^{f4 s} , R ^{f4 s} may be the same group or different groups.
_{^{-SO 2 X 4 (SO 2 R}} f4) e - The _{^{Z +, -SO 3 - Z +}} , -SO 2 N (SO 2 R f4) - H +, or ^{_{-SO 2 C (SO 2 R f4}} ) ₂ ^- Z ⁺ .

  Examples of the unit (u4) include units (u4-1) to (u4-4). From the viewpoint that the production of the polymer (H4) is easy and industrial implementation is easy, the unit (u4-1) Is preferred.

Other units:
The polymer (H4) may further have structural units based on other monomers described later. Moreover, you may have the said unit (u1), the unit (u2), and / or the unit (u3). What is necessary is just to adjust suitably the ratio of another unit so that the ion exchange capacity of a polymer (H4) may become the preferable range mentioned later.
As the other unit, a structural unit based on a perfluoromonomer is preferable. From the viewpoint that the polymer (H4) does not swell excessively with water, it has a cyclic structure and does not have a cation exchange group or its precursor group. More preferred are structural units based on monomers.

The polymer (H4) may have one unit (u4) and one other unit, or two or more units.
The polymer (H4) is preferably a perfluorocarbon polymer from the viewpoint of chemical durability.

  The ion exchange capacity of the polymer (H4) is preferably 0.7 to 2.3 meq / g dry resin, more preferably 1.1 to 2.0 meq / g dry resin. If the ion exchange capacity is 0.7 meq / g dry resin or more, proton conductivity is increased, so that sufficient battery output can be obtained. If the ion exchange capacity is 2.3 meq / g dry resin or less, it is easy to synthesize a polymer having a high molecular weight, and the polymer (H4) does not swell excessively with water, so that the mechanical strength can be maintained. .

(Polymer (H5))
The polymer (H5) is a fluorine-containing polymer having the unit (u5) (excluding the polymer (H6)).

However, R ²¹ is a C 1-6 perfluoroalkylene group or a C 2-6 perfluoroalkylene group having an etheric oxygen atom between carbon-carbon bonds, and R ²² is a fluorine atom, carbon number 1-6 perfluoroalkyl group, a carbon - perfluoroalkyl group having 2 to 6 carbon atoms having an oxygen atom of the etheric between carbon bond or _{^{-R 21 (SO 2 X 5 (}} SO 2 R f5) f), - Z ⁺ Group, R ^f5 is a perfluoroalkyl group which may have an etheric oxygen atom, X ⁵ is an oxygen atom, a nitrogen atom or a carbon atom, and f is an oxygen atom of X ⁵ And 0 when X ⁵ is a nitrogen atom, 2 when X ⁵ is a carbon atom, and Z ⁺ is H ⁺ , a monovalent metal ion, or one or more hydrogen atoms are hydrocarbon groups And replace It is an ammonium ion that may be used. An organic group means a group containing one or more carbon atoms.

Unit (u5):
When the perfluoroarylene group of R ²¹ has an etheric oxygen atom, the number of oxygen atoms may be one or two or more. The perfluoroarylene group may be linear or branched, and is preferably linear.

When the perfluoroalkyl group of R ²² has an etheric oxygen atom, the number of oxygen atoms may be one or two or more. The perfluoroalkyl group may be linear or branched, and is preferably linear. When the unit (u5) has two R ^{21 s} , R ²¹ may be the same group or may be different groups.

1-8 are preferable and, as for carbon number of the perfluoroalkyl group of ^Rf5 , 1-6 are more preferable. In the case of having two or more R ^f5 , R ^f5 may be the same group or different groups.
The _{^{Z +, -SO 3 - - -SO}} 2 X 5 (SO 2 R f5) f Z +, -SO 2 N (SO 2 R f5) - H +, or ^{_{-SO 2 C (SO 2 R f5}} ) ₂ ^- Z ⁺ .

  Examples of the unit (u5) include units (u5-1) to (u5-2).

Other units:
The polymer (H5) may further have structural units based on other monomers described later. Moreover, you may have the said unit (u1), unit (u2), unit (u3), and / or unit (u4). What is necessary is just to adjust suitably the ratio of another unit so that the ion exchange capacity of a polymer (H5) may become the preferable range mentioned later.
As the other unit, a structural unit based on a perfluoromonomer is preferable. From the viewpoint that the polymer (H5) does not swell excessively with water, it has a cyclic structure and does not have a cation exchange group or its precursor group. More preferred are structural units based on monomers.

The polymer (H5) may have one unit (u5) and one other unit, or two or more units.
The polymer (H5) is preferably a perfluorocarbon polymer from the viewpoint of chemical durability.

  The ion exchange capacity of the polymer (H5) is preferably 0.7 to 2.3 meq / g dry resin, more preferably 1.1 to 2.0 meq / g dry resin. If the ion exchange capacity is 0.7 meq / g dry resin or more, proton conductivity is increased, so that sufficient battery output can be obtained. If the ion exchange capacity is 2.3 meq / g dry resin or less, it is easy to synthesize a polymer having a high molecular weight, and the polymer (H5) does not swell excessively with water, so that the mechanical strength can be maintained. .

(Polymer (H6))
The polymer (H6) is a fluorine-containing polymer having units (u6).

However, R ³¹ is perfluoroalkylene group or a C 1 to 6 carbon atoms - a perfluoroalkylene group having 2 to 6 carbon atoms and having an etheric oxygen atom between carbon-carbon bond, R ³² to R ³⁵ are each independently Are a fluorine atom, a C 1-6 perfluoroalkyl group, or a C 2-6 perfluoroalkyl group having an etheric oxygen atom between carbon-carbon bonds, R ³⁶ is a single bond, carbon number 1 -6 perfluoroalkylene group or a C 2-6 perfluoroalkylene group having an etheric oxygen atom between carbon-carbon bonds, and R ^f6 is a perfluoroalkyl group optionally having an etheric oxygen atom and a, X ⁶ is an oxygen atom, a nitrogen atom or a carbon atom, g is 0 if X ⁶ is an oxygen atom, X ⁶ is a nitrogen atom A case 1, X ⁶ is 2 when carbon atoms, Z ⁺ is, H ^+, is a monovalent metal ion or one or more hydrogen atoms hydrocarbon group as the optionally substituted ammonium ion, . An organic group means a group containing one or more carbon atoms.

Unit (u6):
When the perfluoroarylene group for R ³¹ has an etheric oxygen atom, the oxygen atom may be one or may be two or more. The perfluoroarylene group may be linear or branched, and is preferably linear.

When the perfluoroalkyl group of R ^{32 to} R ³⁵ has an etheric oxygen atom, the oxygen atom may be one or two or more. The perfluoroalkyl group may be linear or branched, and is preferably linear.

When the perfluoroarylene group of R ³⁶ has an etheric oxygen atom, the oxygen atom may be one or two or more. The perfluoroarylene group may be linear or branched, and is preferably linear.

1-8 are preferable and, as for carbon number of the perfluoroalkyl group of ^Rf6 , 1-6 are more preferable.
_{^{-SO 2 X 6 (SO 2 R}} f6) g - as ^{Z + _{is, -SO 3 - Z +, -SO}} 2 N (SO 2 R f6) - H + or ^{_{-SO 2 C (SO 2 R f6}} ), ₂ ^- Z ⁺ .

  Examples of the unit (u6) include units (u6-1) to (u6-2).

Other units:
The polymer (H6) may further have structural units based on other monomers described later. Further, the unit (u1), the unit (u2), the unit (u3), the unit (u4) and / or the unit (u5) may be included. What is necessary is just to adjust suitably the ratio of another unit so that the ion exchange capacity of a polymer (H6) may become the preferable range mentioned later.
As the other unit, a structural unit based on a perfluoromonomer is preferable. From the viewpoint that the polymer (H6) does not swell excessively with water, it has a cyclic structure and does not have a cation exchange group or its precursor group. More preferred are structural units based on monomers.

The polymer (H6) may have one each of the unit (u6) and other units, or may have two or more of each.
The polymer (H6) is preferably a perfluorocarbon polymer from the viewpoint of chemical durability.

  The ion exchange capacity of the polymer (H6) is preferably 0.7 to 2.3 meq / g dry resin, more preferably 1.1 to 2.0 meq / g dry resin. If the ion exchange capacity is 0.7 meq / g dry resin or more, proton conductivity is increased, so that sufficient battery output can be obtained. If the ion exchange capacity is 2.3 meq / g dry resin or less, it is easy to synthesize a polymer having a high molecular weight, and the polymer (H6) does not swell excessively with water, so that the mechanical strength can be maintained. .

(Method for producing fluorine-containing ion exchange resin)
As a manufacturing method of a fluorine-containing ion exchange resin, the method which has the following process (I)-(III) is mentioned, for example.
(I) A step of obtaining a precursor polymer (hereinafter referred to as polymer (F)) having —SO ₂ F (a precursor group of a cation exchange group).
(II) Polymer (F) was hydrolyzed treated -SO ₂ F to _-SO ³ - ^{M +} (However, ^{M +} is a monovalent metal ion or one or more hydrogen atoms is replaced with a hydrocarbon group And a salt-type polymer (H).
(III) A step of converting the —SO ₃ ⁻ M ⁺ to —SO ₃ ⁻ H ⁺ by acidifying the salt type polymer (H) as necessary to obtain an acid type polymer (H).

(Process (I))
Production of polymer (F1):
The polymer (F1) which is a precursor polymer of the polymer (H1) can be obtained by polymerizing the monomer (m1) and, if necessary, another monomer.

  As the monomer (m1), monomers (m1-1) to (m1-4) are preferable.

  The monomer (m1) is, for example, D.I. J. et al. Vauham, “Du Pont Innovation”, Vol. 43, No. 3, 1973, p. 10 and the method described in the examples of US Pat. No. 4,358,412 can be used for the production by known synthetic methods.

  Examples of other monomers include TFE, chlorotrifluoroethylene, trifluoroethylene, vinylidene fluoride, vinyl fluoride, ethylene, propylene, perfluoro α-olefins (such as hexafluoropropylene), and (perfluoroalkyl) ethylenes. ((Perfluorobutyl) ethylene, etc.), (perfluoroalkyl) propenes (3-perfluorooctyl-1-propene, etc.), perfluorovinyl ethers (perfluoro (alkyl vinyl ether), perfluoro (etheric oxygen atom-containing alkyl vinyl ether, etc.), cyclic A perfluoromonomer having a structure and not having a cation exchange group or its precursor group, a cyclization polymerizable perfume having no cation exchange group or its precursor group and capable of forming a cyclic structure simultaneously with polymerization Oromonoma, and the like.

Examples of the polymerization method include known polymerization methods such as a bulk polymerization method, a solution polymerization method, a suspension polymerization method, and an emulsion polymerization method. Moreover, you may superpose | polymerize in a liquid or supercritical carbon dioxide.
Polymerization is performed under conditions where radicals occur. Examples of the method for generating radicals include a method of irradiating radiation such as ultraviolet rays, γ rays, and electron beams, a method of adding a radical initiator, and the like.

Production of polymer (F2):
The polymer (F2) which is a precursor polymer of the polymer (H2) can be obtained by polymerizing the monomer (m2) and, if necessary, another monomer.

  As the monomer (m2), monomers (m2-1) to (m2-3) are preferable.

  The monomer (m2) can be produced by a known synthesis method such as the method described in International Publication No. 2007/013533.

As another monomer, the monomer illustrated by the manufacturing method of a polymer (F1) is mentioned, for example.
Examples of the polymerization method include the same methods as the polymerization method in the method for producing the polymer (F1).

Production of polymer (F3):
The polymer (F3) which is a precursor polymer of the polymer (F3) can be produced, for example, through the following steps.
(I) A step of converting the —SO ₂ F of the polymer (F) to —SO ₂ NH ₂ to obtain a polymer (G).
_{(Ii) FSO 2 (CF 2} ) the polymer (G) is reacted with d SO ₂ F, a _{-SO 2} NH 2 _-SO 2 ^N - converting ^{_{(H +) SO 2 (CF}} 2) to d SO ₂ F And obtaining the polymer (F3).

Step (i):
Examples of the polymer (F) include the polymer (F1).
Examples of the method for converting —SO ₂ F into —SO ₂ NH ₂ include a method in which ammonia is brought into contact with the polymer (F).
Examples of a method for bringing ammonia into contact with the polymer (F) include a method in which ammonia is brought into direct contact with the polymer (F), a method in which ammonia is blown into a polymer solution in which the polymer (F) is dissolved, and a method in which the polymer (F) is used. The method etc. which are made to contact ammonia in the state swollen in the solvent are mentioned.

Step (ii):
FSO ₂ (CF ₂ ) _d SO ₂ F can be synthesized by a known method. As a synthesis method, when d is 2, for example, the following method may be mentioned.
ICF ₂ CF ₂ I, which is an adduct of TFE and iodine, is converted into NaSO ₂ CF ₂ CF ₂ SO ₂ Na by a known method, and then converted to ClSO ₂ CF ₂ CF ₂ SO ₂ Cl. To FSO ₂ CF ₂ CF ₂ SO ₂ F.
A method of synthesizing tetrafluoroethane sultone by reacting TFE with anhydrous sulfuric acid, opening the ring, and then hydrolyzing to FSO ₂ CF ₂ COOH, and further coupling by Kolbe electrolysis 2010-095470).

In the step (ii), it is preferable to swell or dissolve the polymer (F) in an aprotic polar solvent and to react with FSO ₂ (CF ₂ ) _d SO ₂ F.
Examples of the aprotic polar solvent include N, N-dimethylacetamide, N, N-dimethylformamide, 1,3-dimethyl-2-imidazolidinone, N-methyl-2-pyrrolidone, dimethyl sulfoxide, sulfolane, γ-butyrolactone, acetonitrile, Tetrahydrofuran, 1,4-dioxane and the like can be mentioned.

It is also preferable to use a reaction accelerator when FSO ₂ (CF ₂ ) _d SO ₂ F is reacted with the polymer (F). As the reaction accelerator, a tertiary organic amine is preferable.
In the step (ii), it is preferable not to mix moisture in order to suppress hydrolysis of FSO ₂ (CF ₂ ) _d SO ₂ F.

Production of polymer (F4):
The polymer (F4) which is a precursor polymer of the polymer (H4) can be obtained by polymerizing the monomer (m4) and, if necessary, another monomer.

  Examples of the monomer (m4) include monomers (m4-1) to (m4-4), and the monomer (m4-1) is preferable from the viewpoint of easy synthesis and high polymerization reactivity.

  The monomer (m4) can be synthesized by a method described in International Publication No. 2003/037885, JP-A-2005-314388, JP-A-2009-040909, and the like.

As another monomer, the monomer illustrated by the manufacturing method of a polymer (F1) is mentioned, for example.
Examples of the polymerization method include the same methods as the polymerization method in the method for producing the polymer (F1).

Production of polymer (F5):
The polymer (F5) which is a precursor polymer of the polymer (H5) can be obtained by polymerizing the monomer (m5) and, if necessary, another monomer.

  Examples of the monomer (m5) include monomers (m5-1) to (m5-2).

  The monomer (m5) can be synthesized by the method described in JP-A No. 2006-152249.

As another monomer, the monomer illustrated by the manufacturing method of a polymer (F1) is mentioned, for example.
Examples of the polymerization method include the same methods as the polymerization method in the method for producing the polymer (F1).

Production of polymer (F6):
The polymer (F6) which is a precursor polymer of the polymer (H6) can be obtained by polymerizing the monomer (m6) and, if necessary, another monomer.

  Examples of the monomer (m6) include monomers (m6-1) to (m6-2).

  The monomer (m6) can be synthesized by a method described in JP-A-2006-241302.

As another monomer, the monomer illustrated by the manufacturing method of a polymer (F1) is mentioned, for example.
Examples of the polymerization method include the same methods as the polymerization method in the method for producing the polymer (F1).

Fluorination treatment of polymer (F):
If necessary, the unstable terminal group of the polymer (F) may be fluorinated by bringing the polymer (F) and fluorine gas into contact with each other.
The unstable terminal group is a group formed by a chain transfer reaction, a group based on a radical initiator, and the like, specifically, —C (O) OH, —CF═CF ₂ , —C (O) F. a -CF ₂ H and the like. By fluorinating or stabilizing the unstable terminal group, decomposition of the finally obtained polymer (H) is suppressed, and durability is improved.

The fluorine gas may be diluted with an inert gas such as nitrogen, helium or carbon dioxide, or may be used as it is without being diluted.
The temperature at which the polymer (F) is brought into contact with the fluorine gas is preferably from room temperature to 300 ° C, more preferably from 50 to 250 ° C, further preferably from 100 to 220 ° C, particularly preferably from 150 to 200 ° C.
The contact time between the polymer (F) and the fluorine gas is preferably 1 minute to 1 week, and more preferably 1 to 50 hours.

(Process (II))
The -SO ₂ F of the polymer (F) by hydrolyzing _-SO ³ - and ^{M +,} obtaining the salt form of the polymer (H). In the case of the polymer ^{_{(F3), -SO 2 N -}} (H +) SO 2 (CF 2) d SO 2 F is ^{_{-SO 2 N - (M +)}} SO 2 (CF 2) 2 SO 3 - M Converted to ⁺ .

  The hydrolysis treatment is performed, for example, by bringing the polymer (F) and the basic compound into contact in a solvent. Specifically, it is preferable to hydrolyze the polymer (F) by dispersing it in a solution of the basic compound by stirring or the like.

Examples of the basic compound include sodium hydroxide and potassium hydroxide.
Examples of the solvent include water, a mixed solvent of water and a polar solvent, and the like. Examples of the polar solvent include alcohols (methanol, ethanol, etc.), dimethyl sulfoxide and the like.

The concentration of the basic compound is preferably 25 to 40% by mass in the basic compound solution.
The temperature for the hydrolysis treatment is preferably 80 to 95 ° C.
The time for the hydrolysis treatment is preferably 10 to 20 hours.

(Step (III))
_-SO ³ salt forms of the polymer (H) - and acid form an ^{M +} _-SO ³ - and ^{H +,} to obtain the acid form of the polymer (H). In the case of a salt form of the polymer ^{_{(H3), -SO 2 N -}} (M +) SO 2 (CF 2) d SO 3 - M + is ^{_{-SO 2 N - (H +)}} SO 2 (CF 2) Converted to ₂ SO ₃ ⁻ H ⁺ .
The acidification treatment is performed, for example, by bringing the salt type polymer (H) into contact with an aqueous solution of an acid (sulfuric acid, hydrochloric acid, nitric acid, etc.). Specifically, it is preferable to perform the acidification treatment by dispersing the salt-type polymer (H) in an aqueous acid solution by stirring or the like.

The concentration of the acid in the acid aqueous solution is preferably 2 to 3N.
The temperature for the acidification treatment is preferably 80 to 90 ° C.
The time for the acidification treatment is preferably 4 to 7 hours.

(Other aspects)
Polymer cation exchange group (H) is _{^{-SO 2 N (SO 2 R f}} ) - Z + (. However, ^{R f,} is etheric perfluoroalkyl group which may have an oxygen atom) of In this case, a known imidization treatment may be performed instead of the hydrolysis treatment.

Examples of the imidization treatment include the following methods.
- and -SO ₂ ^F, a method of reacting the R _f SO 2 NHM.
A method of reacting —SO ₂ F and R ^f SO ₂ NH _{2 in} the presence of an alkali metal hydroxide, an alkali metal carbonate, MF, ammonia, or a primary to tertiary amine.
- and -SO ₂ ^F, a method of reacting the _{R f SO 2 NMSi (CH 3} ) 3.

<Solid polymer fuel cell>
The polymer electrolyte fuel cell of the present invention can be obtained by disposing separators in which grooves serving as gas flow paths are formed on both surfaces of the membrane electrode assembly 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 can also be applied to a methanol fuel cell that generates power by supplying methanol to the anode.

  The polymer electrolyte fuel cell of the present invention described above has good power generation characteristics because it includes a membrane electrode assembly with low internal resistance. Moreover, since the membrane electrode assembly in which the amount of hydrogen leakage is suppressed is provided, the power generation efficiency is high. Moreover, since the membrane electrode assembly with high mechanical strength is provided, durability is high.

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 5, 8, and 9 are examples, and examples 6, 7, and 10 are comparative examples.

(Cell voltage and internal resistance at the beginning of operation)
The membrane electrode assembly is incorporated in a power generation cell, hydrogen (utilization rate 70%) and air (utilization rate 50%) are supplied to the anode and cathode, respectively, at normal pressure, and a current density of 1. The cell voltage at the initial stage of operation at 0 A / cm ² and the internal resistance by the current interruption method were measured. Note that 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 (relative humidity in the cell: 100% RH).

(Hydrogen leak amount)
Next, the air supplied to the cathode side is changed to nitrogen, and the solid polymer electrolyte membrane is permeated by the linear sweep voltammetry method in which the cathode potential is changed from 0.07 to 0.5 V at a rate of 0.5 mV / second. The amount of leaked hydrogen was measured as the amount of current.

(TQ value)
The TQ value (unit: ° C.) is an index of the molecular weight of the polymer. 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.
The TQ value was obtained by using a flow tester CFT-500A (manufactured by Shimadzu Corporation) to measure the extrusion amount of the polymer by changing the temperature and measuring the temperature at which the extrusion amount becomes 100 mm ³ / sec.

(Ion exchange capacity)
To a container made of polycarbonate, 0.7 g of the acid type polymer (H) and 10 mL of a 0.35N aqueous sodium hydroxide solution were added, and the mixture was allowed to stand at 60 ° C. for 40 hours, whereby —SO _{3 of the} polymer (H). ^- the H ⁺ completely _-SO ³ - was converted to Na ^+. The ion exchange capacity of the polymer (H) was calculated by back titrating the solution with 0.1N hydrochloric acid and determining the amount of sodium hydroxide in the solution.

(Radical initiator)
Compound (AP1): A compound represented by the following formula (Wako Pure Chemical Industries, V-601).

  Compound (AP2): A compound represented by the following formula (azobisisobutyronitrile).

(Fluorine-containing solvent)
Compound (BS1): C ₆ F ₁₃ H,
Compound (BS2): CF ₃ CH ₂ OCF ₂ CF ₂ H,
Compound (BS3): CClF ₂ CF ₂ CHClF,
Compound _{(BS4): CH 3 CCl 2} F.

(Fluorine-containing monomer)
Compound (C): Monomer (m1-1) represented by the following formula.

  TFE: a compound represented by the following formula (tetrafluoroethylene).

(Polymer (H1-1))
A stainless steel autoclave having an internal volume of 230 mL was charged with 170 g of the compound (C), and freeze-deaerated using liquid nitrogen. After raising the temperature to 65 ° C., 0.205 MPa of nitrogen was introduced. After confirming that the pressure did not change, TFE was introduced and the total pressure was 1.275 MPaG. After 1.04 g of a 5.0 mass% solution of the compound (AP2) dissolved in the compound (BS3) was added under pressure with nitrogen, the addition line was washed with 2.26 g of the compound (BS1). TFE was continuously supplied while keeping the temperature and pressure constant. After 8 hours from the start of polymerization, the autoclave was cooled to stop the polymerization reaction.
The product extracted from the autoclave was diluted with the compound (BS3), added to the compound (BS4), aggregated the polymer, and then filtered. The polymer was washed by repeatedly stirring and filtering the polymer in the compound (BS4), and dried under reduced pressure at 80 ° C. overnight. The obtained polymer TQ was 234 ° C. Furthermore, the obtained polymer was immersed in an 80 ° C. aqueous solution containing 20% by mass of methanol and 15% by mass of potassium hydroxide for 40 hours to hydrolyze the —SO ₂ F group in the polymer, and —SO ₃ Converted to group K. Subsequently, the polymer was immersed in a 3 mol / L aqueous hydrochloric acid solution at 75 ° C. for 2 hours. The hydrochloric acid aqueous solution was replaced, and the same treatment was further repeated 4 times to obtain a polymer (H1-1) in which —SO ₃ K groups in the polymer were converted to sulfonic acid groups. The polymer (H1-1) was thoroughly washed with ultrapure water. This operation was repeated to obtain about 300 g of polymer (H1-1). The ion exchange capacity was 1.241 meq / g dry resin.

(Ion exchange resin liquid (AA1))
Using an Hastelloy autoclave with an internal volume of 2 L, 420 g of ethanol and 280 g of ultrapure water were added, and 272 g of polymer (H1-1) was added while stirring at 100 rpm using a double helical ribbon blade. Since the viscosity immediately increased due to swelling of the polymer in about 10 minutes, the stirring was continued while the rotational speed was once decreased to 6 rpm, and the temperature was maintained by heating to 105 ° C. in about 80 minutes. As the viscosity gradually decreases during the heating process, the stirring speed is gradually increased at about 10 rpm, and finally the rotational speed is increased to 150 rpm to maintain the rotational speed and temperature. And stirred for 6 hours. Then, it cooled to 25 degreeC in about 60 minutes, hold | maintaining the rotation speed, and obtained the ion exchange resin liquid (AA1). The solid content concentration of the ion exchange resin liquid (AA1) was 28% by mass. Further, by using the E type viscometer was measured the viscosity of the ion exchange resin solution at a shear rate of ^{10s -1} at 25 ° C. (AA1), was 190 mPa · s.

(Ion exchange resin liquid (AA2))
A 300 mL glass round bottom flask was charged with 100 g of the ion exchange resin liquid (AA1) and 0.21 g of cerium carbonate hydrate (Ce ₂ (CO ₃ ) ₃ · 8H ₂ O), and PTFE meniscus The mixture was stirred with a wing at room temperature for 8 hours. Bubbles were generated due to the generation of CO ₂ from the start of stirring, but finally a uniform transparent ion exchange resin liquid (AA2) was obtained. Using an E-type viscometer, the viscosity of the ion exchange resin liquid (AA2) at a shear rate of 10 s ^{−1 at} 25 ° C. was measured to be 195 mPa · s.
The ion exchange resin liquid (AA2) was cast on a ETFE film (Asahi Glass Co., Aflex 100N, thickness: 100 μm) with a die coater, pre-dried at 80 ° C. for 10 minutes, and then at 120 ° C. for 10 minutes. The film was dried and further annealed at 150 ° C. for 30 minutes to obtain a solid polymer electrolyte membrane having a thickness of 50 μm.
Cut out a 5cm x 5cm size membrane from the solid polymer electrolyte membrane, leave it in dry nitrogen for 16 hours, then weigh the mass precisely and impregnate it in 0.1N HCl aqueous solution to completely cerium ions A liquid extracted was obtained. When this liquid was measured by inductively coupled plasma (ICP) emission analysis to quantify cerium in the solid polymer electrolyte membrane, the amount of cerium was 0.35% by mass with respect to the mass of the membrane.

(Polymer (H1-2))
A stainless steel autoclave having an internal volume of 230 mL was charged with 170 g of the compound (C), and freeze-deaerated using liquid nitrogen. After raising the temperature to 65 ° C., 0.212 MPa of nitrogen was introduced. After confirming that the pressure did not change, TFE was introduced and the total pressure was 1.312 MPaG. After 2.65 g of a 1.0 mass% solution of compound (AP1) dissolved in compound (BS1) was added under pressure with nitrogen, the addition line was washed with 2.35 g of compound (BS1). TFE was continuously supplied while keeping the temperature and pressure constant. Seven hours after the start of polymerization, the autoclave was cooled to stop the polymerization reaction.
The product extracted from the autoclave was diluted with the compound (BS1), added to the compound (BS2), aggregated the polymer, and then filtered. The polymer was washed by repeating stirring and filtration of the polymer in the compound (BS2), and dried under reduced pressure at 80 ° C. overnight. The obtained polymer TQ was 227 ° C. Furthermore, the obtained polymer was immersed in an 80 ° C. aqueous solution containing 20% by mass of methanol and 15% by mass of potassium hydroxide for 40 hours to hydrolyze the —SO ₂ F group in the polymer, and —SO ₃ Converted to group K. Subsequently, the polymer was immersed in a 3 mol / L aqueous hydrochloric acid solution at 75 ° C. for 2 hours. The hydrochloric acid aqueous solution was exchanged, and the same treatment was repeated four more times to obtain a polymer (H1-2) in which —SO ₃ K groups in the polymer were converted to sulfonic acid groups. The polymer (H1-2) was sufficiently washed with ultrapure water. This operation was repeated to obtain about 300 g of polymer (H1-2). The ion exchange capacity was 1.250 meq / g dry resin.

(Ion exchange resin liquid (AV1))
An ion exchange resin liquid (AV1) was obtained in the same manner as the method for obtaining the ion exchange resin liquid (AA1) except that the polymer (H1-2) was used instead of the polymer (H1-1).

(Ion exchange resin liquid (AV2))
An ion exchange resin liquid (AV2) was obtained in the same manner as the method for obtaining the ion exchange resin liquid (AA2) except that the ion exchange resin liquid (AV1) was used instead of the ion exchange resin liquid (AA1). .

(Polymer (H1-3))
In a stainless steel autoclave with an internal volume of 2575 mL, 1959 g of the compound (C) was charged and degassed under reduced pressure while cooling with ice water. As a solvent, 23.34 g of the compound (BS1) was charged. After raising the temperature to 57 ° C., 0.109 MPa of nitrogen was introduced. After confirming that the pressure did not change, TFE was introduced and the total pressure was set to 0.809 MPaG. After adding 5.95 g of a 3.23 mass% solution of compound (AP1) dissolved in compound (BS1) under pressure with nitrogen, the addition line was washed with 4.00 g of compound (BS1). TFE was continuously supplied while keeping the temperature and pressure constant. After 14 hours from the start of polymerization, the autoclave was cooled to stop the polymerization reaction.
The product extracted from the autoclave was diluted with the compound (BS1), added to the compound (BS2), aggregated the polymer, and then filtered. The polymer was washed by repeating stirring and filtration of the polymer in the compound (BS2), and dried under reduced pressure at 50 ° C. overnight. The resulting polymer had a TQ of 220 ° C. Furthermore, the obtained polymer was immersed in an 80 ° C. aqueous solution containing 20% by mass of methanol and 15% by mass of potassium hydroxide for 40 hours to hydrolyze the —SO ₂ F group in the polymer, and —SO ₃ Converted to group K. Subsequently, the polymer was immersed in a 3 mol / L aqueous hydrochloric acid solution at 75 ° C. for 2 hours. The aqueous hydrochloric acid solution was exchanged, and the same treatment was further repeated 4 times to obtain a polymer (H1-3) in which —SO ₃ K groups in the polymer were converted to sulfonic acid groups. The polymer (H1-3) was thoroughly washed with ultrapure water. This operation was repeated to obtain about 300 g of polymer (H1-3). The ion exchange capacity was 1.413 meq / g dry resin.

(Ion exchange resin liquid (BV1))
Using an Hastelloy autoclave with an internal volume of 2 L, 420 g of ethanol and 280 g of ion-exchanged water were added, and 272 g of polymer (H1-3) was added while stirring at 80 rpm using a double helical ribbon blade. Since the viscosity immediately increased due to swelling of the polymer in about 10 minutes, the stirring was continued while the rotational speed was once decreased to 6 rpm, and the temperature was maintained by heating to 105 ° C. in about 80 minutes. As the viscosity gradually decreases during the heating process, the stirring speed is gradually increased at about 10 rpm, and finally the rotational speed is increased to 150 rpm to maintain the rotational speed and temperature. And stirred for 6 hours. Thereafter, while maintaining the number of rotations, it was cooled to 25 ° C. in about 60 minutes to obtain an ion exchange resin liquid (BV1). The solid content concentration of the ion exchange resin liquid (BV1) was 28% by mass. Moreover, it was 140 mPa * s when the viscosity of the ion exchange resin liquid (BV1) in the shear rate of 100 s- ¹ in 25 degreeC was measured using the E-type viscosity meter.

(Ion exchange resin liquid (BV2))
A 300 mL glass round bottom flask was charged with 100 g of ion exchange resin liquid (BV1) and 0.24 g of cerium carbonate hydrate (Ce ₂ (CO ₃ ) ₃ · 8H ₂ O), and PTFE meniscus The mixture was stirred with a wing at room temperature for 8 hours. Bubbles were generated due to the generation of CO ₂ from the start of stirring, but finally a uniform transparent ion exchange resin liquid (BV2) was obtained. Using an E-type viscometer, the viscosity of the ion exchange resin liquid (BV2) at a shear rate of 10 s ^{−1 at} 25 ° C. was measured and found to be 145 mPa · s.
The ion exchange resin liquid (BV2) was cast on a ETFE film (Asahi Glass Co., Aflex 100N, thickness: 100 μm) with a die coater, pre-dried at 80 ° C. for 10 minutes, and then at 120 ° C. for 10 minutes. The film was dried and further annealed at 150 ° C. for 30 minutes to obtain a solid polymer electrolyte membrane having a thickness of 50 μm.
Cut out a 5cm x 5cm size membrane from the solid polymer electrolyte membrane, leave it in dry nitrogen for 16 hours, then weigh the mass precisely and impregnate it in 0.1N HCl aqueous solution to completely cerium ions A liquid extracted was obtained. When this liquid was measured by inductively coupled plasma (ICP) emission analysis to determine the amount of cerium in the solid polymer electrolyte membrane, the amount of cerium was 0.4% by mass relative to the mass of the membrane.

(Example 1)
In a 10 μm thick metal foil made of stainless steel (SUS314), a regular hexagon having a pattern d shown in FIG. 5 with an interval d between opposing sides of about 100 μm is used, and a regular hexagonal interval w is 41 μm (the distance between centers is 141 μm) to obtain a porous sheet having an aperture ratio of about 50%.

Step (a):
As a carrier film, prepare an ETFE film (Asahi Glass Co., Aflex 100N, thickness: 100 μm), apply an ion exchange resin liquid (AA2) on the surface with a die coater, and dry it in an oven at 80 ° C. for 15 minutes. Further, heat treatment was performed for 1 hour in a dryer at 160 ° C. to form a solid polymer electrolyte membrane having a thickness of 10 μm.

Step (b):
A porous sheet is disposed on the surface of the solid polymer electrolyte membrane, and heat-pressed at 1.5 MPa and 160 ° C. for 2 minutes to obtain a solid polymer electrolyte membrane with a porous sheet in which the porous sheet is bonded to the surface of the solid polymer electrolyte membrane. It was.

Step (c):
Of a catalyst (manufactured by Tanaka Kikinzoku Kogyo Co., Ltd.) supported on a carbon support (specific surface area: 800 m ² / g) so that platinum / cobalt alloy (platinum: cobalt = 57: 6 mass ratio) is contained in 63% of the total mass of the catalyst. 10.0 g was added to 59.6 g of distilled water and stirred well. Further, 62.8 g of ethanol was added and stirred well. To this, 10.6 g of the ion exchange resin liquid (AA1) was added and mixed and pulverized using a planetary ball mill to obtain a catalyst layer forming paste.
The catalyst layer forming paste is applied to the surface of the ETFE film with a die coater, dried in a dryer at 80 ° C. for 15 minutes, and further subjected to a heat treatment in a dryer at 160 ° C. for 30 minutes to form a catalyst layer for the cathode (platinum amount). : 0.35 mg / cm ² ) to form a catalyst layer with a carrier film.

Step (d):
The ETFE film was peeled off from the solid polymer electrolyte membrane with a porous sheet, a catalyst layer with a carrier film was placed on the peeled surface, and the catalyst layer for cathode was transferred by hot pressing at 1.5 MPa at 150 ° C. for 3 minutes.

Step (e):
10.0 g of a catalyst (manufactured by Tanaka Kikinzoku Kogyo Co., Ltd.) supported on a carbon support (specific surface area: 800 m ² / g) so that platinum is contained in 20% of the total mass of the catalyst is added to 94.3 g of distilled water. Stir well. Further, 36.7 g of ethanol was added and stirred well. 22.9 g of the ion exchange resin liquid (AA1) was added thereto, and mixed and pulverized using a planetary ball mill to obtain a catalyst part forming paste.
An anode composed of a filling portion filled in the through-holes of the porous sheet and a layered portion spreading on the surface of the porous sheet, in which the catalyst portion forming paste is applied to the surface of the porous sheet bonded to the solid polymer electrolyte membrane with a die coater Catalyst part (platinum amount: 0.05 mg / cm ² ) was formed, and a membrane catalyst part assembly (electrode area: 25 cm ² ) was obtained.

Step (f):
1. Gas diffusive base materials (manufactured by NOK, trade name: H2315 T10X6 CX96, thickness: 240 μm) are arranged on both surfaces of the membrane catalyst assembly and placed in a press machine heated to 150 ° C. in advance. Hot pressing was performed at a pressing pressure of 5 MPa for 2 minutes to obtain a membrane electrode assembly. From the cross-sectional observation result of the sample, it was found that the ion exchange resin of the solid polymer electrolyte membrane penetrated into the through-hole of the porous sheet by hot pressing about 2 μm at maximum. The evaluation results of the membrane / electrode assembly are shown in Table 1.

(Example 2)
A regular hexagon in which the distance d between opposing sides is about 50 μm in a pattern as shown in FIG. 5 on a metal foil made of SUS314 having a thickness of 5 μm, and a regular hexagonal interval w is 21 μm (center distance is 71 μm). Thus, a porous sheet having an opening ratio of about 50% was obtained by etching.
A membrane / electrode assembly was obtained in the same manner as in Example 1 except that the porous sheet was used and the thickness of the solid polymer electrolyte membrane was changed to 7 μm. The evaluation results of the membrane / electrode assembly are shown in Table 1.

(Examples 3 to 6)
A through hole having a value shown in Table 1 is uniformly formed in a zigzag arrangement by drilling in a 12 μm-thick PPS film (trade name: Torelina, manufactured by Toray Industries, Inc.), and the opening ratios are the values shown in Table 1, respectively. A porous sheet was obtained.
A membrane / electrode assembly was obtained in the same manner as in Example 1 except that the porous sheet was used and the thickness of the solid polymer electrolyte membrane was changed to the thickness shown in Table 1. In Example 6, since the average opening area per one through hole of the porous sheet was large, the polymer electrolyte membrane was slightly deformed so as to be loosened in the through hole. The evaluation results of the membrane / electrode assembly are shown in Table 1.

(Example 7)
A membrane / electrode assembly was obtained in the same manner as in Examples 3 to 6 except that in the step (b), hot pressing was performed at 3 MPa and 160 ° C. for 5 minutes. From the cross-sectional observation result of the sample, it was found that the ion exchange resin of the solid polymer electrolyte membrane had penetrated into the through hole of the porous sheet at a maximum of about 5 μm. The evaluation results of the membrane / electrode assembly are shown in Table 1.

(Example 8)
The ion exchange resin liquid (AA2) used in the step (a) is the ion exchange resin liquid (AV2), the ion exchange resin liquid (AA1) used in the step (c) is the ion exchange resin liquid (AV1), and the process (e). A membrane / electrode assembly was obtained in the same manner as in Example 1 except that the ion exchange resin liquid (AA1) used in 1 was used as the ion exchange resin liquid (AV1). The evaluation results of the membrane / electrode assembly are shown in Table 1.

(Example 9)
The ion exchange resin liquid (AA2) used in step (a) is the ion exchange resin liquid (BV2), the ion exchange resin liquid (AA1) used in step (c) is the ion exchange resin liquid (BV1), and the process (e) A membrane / electrode assembly was obtained in the same manner as in Example 1 except that the ion exchange resin liquid (AA1) used in was used as the ion exchange resin liquid (BV1). The evaluation results of the membrane / electrode assembly are shown in Table 1.

(Example 10)
A membrane / electrode assembly was obtained in the same manner as in Example 1 except that the porous sheet was not used. The evaluation results of the membrane / electrode assembly are shown in Table 1.

In the membrane electrode assemblies of Examples 1 to 5, 8, and 9 that satisfy the conditions of the present invention, the internal resistance was suppressed low, and the amount of hydrogen leak was suppressed.
The membrane electrode assemblies of Examples 6 to 7 in which the penetration thickness of the solid polymer electrolyte membrane entering the through holes of the porous sheet exceeded 4 μm had high internal resistance.
The membrane electrode assembly of Example 10 in which the porous sheet was not disposed had a large amount of hydrogen leak.

  The membrane electrode assembly of the present invention is useful as a membrane electrode assembly for a polymer electrolyte fuel cell which is required to operate stably for a long time.

DESCRIPTION OF SYMBOLS 10 Membrane electrode assembly 20 Anode 22 Porous sheet 22a Through-hole 24 Catalyst part 24a Filling part 24b Layered part 26 Gas diffusion layer 30 Cathode 34 Catalyst layer (catalyst part)
36 Gas diffusion layer 40 Solid polymer electrolyte membrane

Claims (4)

An anode,
A cathode,
A solid polymer electrolyte membrane disposed between the anode and the cathode,
The anode is in contact with the first surface of the solid polymer electrolyte membrane, a porous sheet having a plurality of through holes, and filled in the through holes of the porous sheet to the first surface of the solid polymer electrolyte membrane A catalyst portion containing the catalyst in contact with the
The cathode has a catalyst part containing a catalyst in contact with the second surface of the solid polymer electrolyte membrane, and does not have a porous sheet having a plurality of through holes,
The average opening area per one through hole of the porous sheet is 0.002 to 0.08 mm ² ,
The aperture ratio of the porous sheet is 30 to 80%,
The penetration thickness of the solid polymer electrolyte membrane that penetrates the through-hole of the porous sheet is 4 μm or less,
The porous sheet is made of metal,
A membrane electrode assembly for a polymer electrolyte fuel cell, wherein the thickness of the solid polymer electrolyte membrane (excluding the penetration thickness) is 7 to 20 μm.   The membrane electrode assembly for a polymer electrolyte fuel cell according to claim 1, wherein the porous sheet has a thickness of 5 to 12 μm. The membrane electrode assembly for a polymer electrolyte fuel cell according to claim 1 or 2 , wherein the metal is titanium or a titanium alloy. A polymer electrolyte fuel cell comprising the membrane electrode assembly for a polymer electrolyte fuel cell according to any one of claims 1 to 3 .

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