JP2007149653A - Electrolyte for direct methanol fuel cell and direct methanol fuel cell using same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polymer electrolyte which, while maintaining a high proton conductivity, has an excellent methanol block, and a polymer electrolyte membrane using the above polymer electrolyte, and a direct methanol fuel cell provided with the above polymer electrolyte membrane. <P>SOLUTION: The polymer electrolyte for the direct methanol fuel cell is composed of a repeating structural unit as shown in a general formula (1). In the formula, X stands for either of a direct linking of -O-, -S-, -SO-, -SO<SB>2</SB>- or -CO-, Y for a direct linking or a bivalent or trivalent aromatic group, R<SP>1</SP>, R<SP>2</SP>for each independent hydrogen atom or fluorine atom, i for a number of 0 to 3, k stands for a number of 1 to 12, and l for 1 or 2. R<SP>3</SP>stands for a sulfonic acid group, an alkyl group having a carbon number of 1 to 10, or an aryl group having a carbon number of 6 to 18 which may be substituted. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a polymer electrolyte for a direct methanol fuel cell that is suitably used for a direct methanol fuel cell. Furthermore, the present invention relates to a polymer electrolyte membrane for a direct methanol fuel cell using the polymer electrolyte for a direct methanol fuel cell, and a direct methanol fuel cell using the polymer electrolyte membrane.

Polymers having proton conductivity, that is, polymer electrolytes, are used as materials constituting diaphragms of electrochemical devices such as primary batteries, secondary batteries, and solid polymer fuel cells. For example, a polymer electrolyte membrane having an active ingredient an ion exchange polymer having perfluoroalkylsulfonic acid as a super strong acid in the side chain such as Nafion (registered trademark of DuPont) and having a main chain of perfluoroalkane. However, since it has excellent power generation characteristics when used as a proton conductive membrane for fuel cells, it has been mainly used in the past. However, it has been pointed out that this type of material is very expensive, has low heat resistance, has low film strength, and is not practical without some reinforcement. In addition, when this material is used as a proton conductive membrane material for a liquid fuel type fuel cell typified by a direct methanol type fuel cell, the liquid fuel methanol has a poor barrier property (low methanol barrier property) and an overvoltage at the cathode. Has been pointed out.

Under such circumstances, development of inexpensive polymer electrolytes that can replace the polymer electrolytes has recently been activated. Among them, a polymer obtained by introducing a sulfonic acid group into an aromatic polyether having excellent heat resistance and high film strength, that is, a polymer main chain having an oxygen element and / or a sulfur element and an aromatic ring, and having an ion exchange group. Polyelectrolytes that are directly bonded to part or all of the aromatic rings constituting the main chain are known, such as sulfonated polyetherketone (see, for example, Patent Document 1), sulfonated polyetheretherketone (For example, refer patent document 2), sulfonated polyether ether sulfone (for example, refer nonpatent literature 1), sulfonated polyether sulfone (for example, refer patent document 3), etc. are proposed.

Among these polymer electrolytes, it is also known that the sulfonated polyethersulfone polymer electrolyte described in Patent Document 3 is useful as a proton conductive polymer electrolyte for direct methanol fuel cells.
The polymer main chain has an oxygen element and / or sulfur element and an aromatic ring, and an ion exchange group is bonded to part or all of the aromatic ring constituting the main chain via an alkylene group. Molecular electrolytes (for example, see Patent Document 4), sulfonated polyether ether sulfone aromatic polymer electrolytes in which the aromatic ring constituting the main chain is composed of a monocyclic aromatic ring and a condensed polycyclic aromatic ring It has been proposed (see, for example, Patent Document 5).

Japanese National Patent Publication No. 11-502249 (Claims) JP-T-2002-524631 (Claims, Examples 8 to 10) JP 2003-323904 A (Claims) JP 2003-100317 A (Examples 1 to 4) Japanese Patent Laying-Open No. 2005-206807 (Claims, Examples 1 to 4) Journal of Membrane Science, 83, 211 (1993)

However, when the aromatic polymer electrolyte as described above is used directly for a methanol fuel cell, further improvement has been expected due to the problem that the methanol barrier property is not at a sufficiently satisfactory level.
The object of the present invention is to provide a property that is superior to conventional polymer electrolyte membranes in terms of methanol barrier while maintaining high proton conductivity when used for liquid fuel type fuel cells, particularly direct methanol type fuel cells. And a polymer electrolyte membrane using the polymer electrolyte, and a direct methanol fuel cell using the polymer electrolyte membrane.

As a result of intensive studies to find a polymer electrolyte that can solve the above-mentioned problems, the present inventors have found that a polyarylene polymer electrolyte having a sulfonic acid group coupling mode related to proton conduction as a specific group is directly As a proton conductive membrane of a methanol fuel cell, the present inventors have found that the methanol barrier property and proton conductivity are satisfied at a high level, and further various studies have been made to complete the present invention.

（式中、Ｘは、直接結合、−Ｏ−、−Ｓ−、−ＳＯ−、−ＳＯ₂−、−ＣＯ−のいずれかを表し、Ｙは直接結合、２価若しくは３価の芳香族基を表し、Ｒ¹、Ｒ²は、互いに独立に水素原子又はフッ素原子を表し、iは、０〜３の数を表し、ｋは１〜１２の数を表し、ｌは、Ｙが直接結合又は２価の芳香族基の場合は１、Ｙが３価の芳香族基の場合は２を表す。Ｒ³は、スルホン酸基、炭素数が１〜１０であるアルキル基又は炭素数が６〜１８である置換されていてもよいアリール基を表し、Ｒ³が複数ある場合は、それらは同一でも異なっていてもよい。） That is, the present invention provides [1] a polymer electrolyte for a direct methanol fuel cell, which has a repeating structure represented by the following general formula (1).

(In the formula, X represents a direct bond, —O—, —S—, —SO—, —SO ₂ — or —CO—, and Y represents a direct bond, a divalent or trivalent aromatic group. R ¹ and R ² each independently represent a hydrogen atom or a fluorine atom, i represents a number of 0 to 3, k represents a number of 1 to 12, and l represents that Y is a direct bond or 1 represents a divalent aromatic group, and 2 represents a trivalent aromatic group, and R ³ represents a sulfonic acid group, an alkyl group having 1 to 10 carbon atoms, or 6 to 6 carbon atoms. 18 represents an optionally substituted aryl group, and when there are a plurality of R ³ , they may be the same or different.)

[2] The direct methanol according to [1] above, wherein 90% or more of the repeating structural units represented by the general formula (1) are bonded at the para position to constitute a main chain. A polymer electrolyte for a fuel cell is provided.

（式中、Ａｒ¹、Ａｒ²は互いに独立に芳香環を有する２価の基を表し、ここで該２価の基にある芳香環は炭素数が１〜１０であるアルキル基又は炭素数が６〜１８であるアリール基で置換されていてもよく、Ｚは、−Ｏ−、−ＳＯ₂−、−ＣＯ−のいずれかを表し、Ｚが複数ある場合、それらは同一でも異なっていてもよい。ｍは１以上の整数を、ｎは０以上の整数を表し、Ｒ⁴は、炭素数が１〜１０であるアルキル基、炭素数が６〜１８である置換されていても良いアリール基又は炭素数２〜２０のアシル基を表し、Ｒ⁴が複数ある場合は、それらは同一でも異なっていてもよい。ｐは０〜４の数を表す。） In addition, the present invention provides [3] a direct methanol type as described in [1] or [2] above, further comprising a repeating structural unit represented by the following general formula (2) and / or (3): Polymer electrolyte for fuel cells.

(In the formula, Ar ¹ and Ar ² independently represent a divalent group having an aromatic ring, and the aromatic ring in the divalent group is an alkyl group having 1 to 10 carbon atoms or a carbon number. 6 to 18 may be substituted with an aryl group, Z represents any of —O—, —SO ₂ —, and —CO—, and when there are a plurality of Z, they may be the same or different. M is an integer of 1 or more, n is an integer of 0 or more, and R ⁴ is an alkyl group having 1 to 10 carbon atoms or an optionally substituted aryl group having 6 to 18 carbon atoms. Or an acyl group having 2 to 20 carbon atoms, and when there are a plurality of R ^{4 s} , they may be the same or different, and p represents a number of 0 to ^4. )

Furthermore, the present invention has [4] a repeating structural unit represented by the general formula (1) in the main chain and a repeating structural unit represented by the general formula (3), and is represented by the general formula (3). 90% or more of the repeating structural units are p-linked, that is, bonded at the para position, the polymer electrolyte for a direct methanol fuel cell according to the above [3],
[5] The polymer electrolyte for direct methanol fuel cells according to the above [1] to [4], wherein Y is a direct bond,
[6] The polymer electrolyte for a direct methanol fuel cell according to any one of [1] to [5], wherein i is 0,
[7] The polymer electrolyte for direct methanol fuel cell according to the above [1] to [6], wherein the ion exchange capacity is 0.5 eq / g to 4 meq / g,
[8] At least one selected from a block composed of a repeating structural unit represented by the general formula (1), a repeating structural unit represented by the general formula (2), and a repeating structural unit represented by the general formula (3). A polymer electrolyte for a direct methanol fuel cell according to the above [1] to [7], wherein the polymer electrolyte is a block copolymer having a block composed of various structural units;

[9] A polymer electrolyte membrane for a direct methanol fuel cell, characterized by using the polymer electrolyte for a direct methanol fuel cell according to [1] to [8] above,
[10] A direct methanol fuel cell using the polymer electrolyte membrane for a direct methanol fuel cell according to the above [9] is provided.

The polyarylene polymer electrolyte of the present invention (hereinafter sometimes referred to as a polyarylene polymer) has a high proton conductivity when used for a solid polymer fuel cell, particularly a direct methanol fuel cell. While retaining, it exhibits excellent methanol barrier properties and has excellent characteristics as an electrolyte membrane for direct methanol fuel cells, and can be suitably used even when a methanol aqueous solution is used as fuel. Further, it can be suitably used for a liquid fuel type fuel cell other than methanol, or a fuel cell using hydrogen gas as a fuel gas.

（式中、ｌは前記と同義である。）
Ｒ¹、Ｒ²は、互いに独立に水素原子又はフッ素原子を表わすが、Ｒ¹、Ｒ²がともに水素原子である場合又はＲ¹、Ｒ²がともにフッ素原子である場合が好ましい。 Hereinafter, the present invention will be described in detail.
The polyarylene polymer of the present invention is characterized in that the form of the free acid has a repeating structure represented by the general formula (1).
Here, X in Formula (1) represents any one of a direct bond, —O—, —S—, —SO—, —SO ₂ —, and —CO—, and among them, a direct bond, —O—, — SO ₂ — and —CO— are preferable.
Y represents a direct bond or a divalent or trivalent aromatic group, and the total number of carbon atoms is usually about 6 to 18, and is derived from an aromatic ring that may have a substituent. Examples of the aromatic ring that may have such a substituent include, for example, a benzene ring, a naphthalene ring, an aromatic group in which a fluorine atom, a methoxy group, an ethoxy group, an isopropyloxy group, a biphenylyl group, a phenoxy group, and a naphthyloxy group are substituted. And a group obtained by removing two or three hydrogen atoms from these aromatic rings. Needless to say, when the number 1 of the sulfonic acid groups is 1, it is divalent, and when 1 is 2, it becomes a trivalent aromatic group. Preferred examples of —Y— (SO ₃ H) ₁ include the following groups when including sulfonic acid groups.

(In the formula, l is as defined above.)
R ¹ and R ² each independently represent a hydrogen atom or a fluorine atom, and it is preferable that R ¹ and R ² are both hydrogen atoms or R ¹ and R ² are both fluorine atoms.

R ³ represents a substituent on the phenylene group constituting the polymer main chain in the repeating structural unit represented by the general formula (1), and is a sulfonic acid group or an alkyl group having about 1 to 10 carbon atoms. Alternatively, it represents an optionally substituted aryl group having about 6 to 18 carbon atoms.
Examples of the alkyl group having about 1 to 10 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group, n-pentyl group, 2,2 -Dimethylpropyl group, cyclopentyl group, n-hexyl group, cyclohexyl group, 2-methylpentyl group, 2-ethylhexyl group, nonyl group and the like, and optionally substituted aryl having about 6 to 18 carbon atoms Examples of the group include a phenyl group and a naphthyl group. Further, these aryl groups include a fluorine atom, a methoxy group, an ethoxy group, an isopropyloxy group, a biphenylyl group, a phenoxy group, a naphthyloxy group, and a sulfonic acid group. Substituted ones are listed.

（式中、Ｒ¹、Ｒ²、Ｒ³、Ｘ、Ｙ、ｉ、ｋ、ｌは前記と同義である。） i is the number of substituted R ³ and represents a number of 0 to 3, i is preferably 0, ie, has no substituent, or is preferably substituted with a methyl group or an ethyl group as R ^3. . k represents a number of 1 to 12, and preferably 2 to 6. l represents 1 when Y is a direct bond or a divalent aromatic group, and represents 2 when Y is a trivalent aromatic group.
In the repeating structural unit represented by the general formula (1), the substitution position of the phenylene group constituting the main chain may be o-, m-, p-, or a mixture of two or more thereof. It is preferred that 90% or more of the repeating structural units are p-linked. That is, the phenylene group constituting the polymer main chain is bonded to other repeating units at the ortho, meta, and para positions, and does not have to be all at the same bonding position, but 90% or more of the repeating structural units are adjacent to each other. It is preferable that 90% or more of the repeating structure represented by the general formula (1) is a repeating structural unit represented by the following general formula (1A). .

(In the formula, R ¹ , R ² , R ³ , X, Y, i, k, and l are as defined above.)

Typical examples of the repeating structural unit represented by the general formula (1) include the following.

As described above, the polyarylene polymer of the present invention includes a polymer having a repeating structural unit represented by the general formula (1) and a part or all of the sulfonic acid group in the form of a salt. Examples of such salt forms include alkali metal salt forms such as lithium salts, sodium salts, potassium salts, and calcium salts, and alkaline earth metal salts. When used as a material for a polymer electrolyte fuel cell, it is preferable that substantially all sulfonic acid groups are in the form of free acid.

Moreover, the polyarylene polymer of the present invention may have a different repeating structural unit in addition to the repeating structural unit represented by the general formula (1) as described above.
For example, it is preferable to further have a repeating structural unit represented by the general formula (2) and / or a repeating structural unit represented by the general formula (3).
Here, Ar ¹ and Ar ² in the general formula (2) each independently represent a divalent group having an aromatic ring. The divalent group includes two divalent groups derived from the aromatic ring, Is a divalent group linked directly or via a linking group.
Examples of such a divalent group include the following groups.

さらに、Ａｒ¹、Ａｒ²は、その芳香環の水素原子の一部または全部が、メチル基、エチル基、ｎ−プロピル基、イソプロピル基、ｎ−ブチル基、ｓｅｃ−ブチル基、ｔｅｒｔ−ブチル基、イソブチル基、ｎ−ペンチル基、２，２−ジメチルプロピル基、シクロペンチル基、ｎ−ヘキシル基、シクロヘキシル基、２−メチルペンチル基、２−エチルヘキシル基、ノニル基、デシル基等の炭素数が１〜１０程度であるのアルキル基；フェニル基、ナフチル基、これらの基にフッ素原子、メトキシ基、エトキシ基、イソプロピルオキシ基、ビフェニリル基、フェノキシ基、ナフチルオキシ基が置換したもの等の総炭素数が６〜１８程度であるアリール基等で置換されていてもよいが、無置換である基が好ましい。

In addition, Ar ¹ and Ar ² are a part of or all of the hydrogen atoms of the aromatic ring, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group. , Isobutyl group, n-pentyl group, 2,2-dimethylpropyl group, cyclopentyl group, n-hexyl group, cyclohexyl group, 2-methylpentyl group, 2-ethylhexyl group, nonyl group, decyl group, etc. An alkyl group of about 10 to 10; a total number of carbon atoms such as phenyl group, naphthyl group, those groups substituted by fluorine atom, methoxy group, ethoxy group, isopropyloxy group, biphenylyl group, phenoxy group, naphthyloxy group, etc. May be substituted with an aryl group or the like of about 6 to 18, but an unsubstituted group is preferred.

Z represents any of —O—, —SO ₂ —, and —CO—, and a plurality of Z may be different from each other. m represents an integer of 1 or more, and n represents an integer of 0 or more.
Typical examples of the repeating structural unit represented by the general formula (2) include the following.

（式中、Ｒ⁴、ｐは前記と同義である。） R ⁴ in the general formula (3) represents a substituent on the benzene ring, and is a sulfonic acid group, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 18 carbon atoms, or 2 to 20 carbon atoms. Represents an acyl group that is about.
Here, examples of the alkyl group having 1 to 10 carbon atoms and the aryl group having 6 to 18 carbon atoms include the same alkyl groups and aryl groups as described above. Examples of the acyl group having 2 to 20 carbon atoms include an acetyl group, a propionyl group, a butyryl group, an isobutyryl group, a benzoyl group, a 1-naphthoyl group, a 2-naphthoyl group, or a fluorine atom or a methoxy group. And an acyl group substituted with a group, an ethoxy group, an isopropyloxy group, a biphenylyl group, a phenoxy group, a naphthyloxy group, a sulfonic acid group, and the like.
Of these, R ⁴ is preferably benzoyl or phenoxybenzoyl. p is the number of R ⁴ bonded to the phenylene group, represents an integer of 0 to 4, and p is preferably 0 or 1.
In the general formula (3), the phenylene groups constituting the main chain are bonded at the ortho position, the meta position, and the para position, and need not be all at the same bonding position, but 90% or more of the repeating structural units are present. It is preferable that both adjacent repeating structural units are bonded at the para position, that is, 90% or more of the repeating structure represented by the general formula (3) is a repeating structural unit represented by the following general formula (3A). Preferably there is.

(Wherein R ⁴ and p are as defined above.)

Typical examples of the repeating structural unit represented by the general formula (3) include the following.

The polyarylene polymer of the present invention is not limited to the repeating structural unit represented by the general formula (1) as described above, and the repeating structural unit represented by the general formula (2) and / or the general formula. Although the repeating structural unit represented by (3) may be present, the composition ratio thereof is 0.5 meq / g when the introduction rate of the acid group as the polyarylene polymer is expressed by ion exchange capacity. A composition ratio of ˜4 meq / g is preferred. When the ion exchange capacity is 0.5 meq / g or more, the ion conductivity becomes higher and the function as a polymer electrolyte for a fuel cell is more excellent, which is preferable. The lower limit of the ion exchange capacity is preferably 1.0 meq / g or more, and particularly preferably 1.5 meq / g or more.
In addition, an ion exchange capacity of 4 meq / g or less is preferable because water resistance becomes better. The upper limit of the ion exchange capacity is preferably 3.8 meq / g or less, and particularly preferably 3.5 meq / g or less.

Further, for example, in the case of having a repeating structural unit represented by the general formula (2) and / or the general formula (3) as described above, the connection mode (copolymerization mode) thereof is represented by the general formula (1). Even in a random copolymer that is random in the arrangement with the repeating structural unit, a block copolymer having a block consisting of the former repeating structural unit and a block consisting of the latter repeating structural unit, Or they may be a combination thereof.
Here, in the case of a block copolymer, the block consists of a repeating structural unit represented by the general formula (1), and a repeating structural unit represented by the general formula (2) and / or the general formula (3). In the case of a block comprising a repeating structural unit represented by the general formula (1), the degree of polymerization is preferably 10 to 100, and the repeating structural unit represented by the general formula (2) In the case of the block which consists of 10, 10-100 are preferable. Moreover, in the case of the block which consists of a repeating structural unit represented by General formula (3), 10-200 are preferable for this repeating structural unit number. Moreover, when it has a block consisting of the repeating structural unit represented by the general formula (1) and a repeating structural unit represented by the general formula (2) and / or the general formula (3), the blocks are directly It may be bonded, or may be bonded via a divalent group as a linking group.

The molecular weight of the polyarylene polymer of the present invention is preferably 5,000 to 1,000,000, and particularly preferably 15,000 to 400,000, in terms of polystyrene-equivalent number average molecular weight.

As typical examples of the polyarylene polymer in the case of having the repeating structural unit represented by the general formula (2) and the repeating structural unit represented by the general formula (3), for example, the following can be exemplified and described above. The number of repeating structural units satisfying such an ion exchange capacity, composition ratio, block length (polymerization degree of the block when a block is formed), molecular weight and the like are preferable. In addition, x and y represent the average degree of polymerization of each repeating structural unit, “ran” represents a random copolymer, and “block” represents a block copolymer.

（式中、Ａｒ¹、Ａｒ²、Ｒ¹〜Ｒ⁴、Ｘ、Ｙ、ｉ、ｋ、ｍ、ｌ、ｐは前記と同義である。Ｑは、縮合反応時に脱離する基を表し、複数のＱは異なる種類であってもよい。） Next, the method for producing the polyarylene polymer of the present invention will be described.
For example, the polyarylene polymer of the present invention comprises a condensation reaction between a monomer represented by the following general formula (4) and a monomer represented by the following general formula (5) and general formula (6) used as necessary. Can be produced by polymerization.

(In the formula, Ar ¹ , Ar ² , R ^{1 to} R ⁴ , X, Y, i, k, m, l, and p are as defined above. Q represents a group that is eliminated during the condensation reaction, Q may be of different types.)

Here, in the case of a reaction in which Qs cause a condensation reaction and aromatic rings are linked by a direct bond, a zero-valent transition metal complex can be used as a catalyst. Specific examples of the group Q which is eliminated during the condensation reaction include, for example, halogen atoms such as chlorine atom, bromine atom and iodine atom, and p-toluenesulfonyloxy group, methanesulfonyloxy group, trifluoromethanesulfonyloxy group and the like. And sulfonic acid ester groups.

The condensation reaction using a zero-valent transition metal complex will be described.
Examples of the zero-valent transition metal complex include a zero-valent nickel complex and a zero-valent palladium complex. Of these, a zerovalent nickel complex is preferably used.
As the zero-valent transition metal complex, a commercially available product or a separately synthesized one may be used for the polymerization reaction system, or may be generated from the transition metal compound by the action of a reducing agent in the polymerization reaction system. In the latter case, for example, a method in which zinc, magnesium or the like is allowed to act on the transition metal compound as a reducing agent.
In any case, it is preferable to add a ligand described later from the viewpoint of improving the yield.

Here, examples of the zero-valent palladium complex include palladium (0) tetrakis (triphenylphosphine). Examples of the zero-valent nickel complex include nickel (0) bis (cyclooctadiene), nickel (0) (ethylene) bis (triphenylphosphine), nickel (0) tetrakis (triphenylphosphine), and the like. Of these, nickel (0) bis (cyclooctadiene) is preferably used.
In addition, when a reducing agent is allowed to act on a transition metal compound to generate a zero-valent transition metal complex, as the transition metal compound used, a compound having a divalent transition metal is usually used. Can also be used. Of these, compounds having divalent nickel and compounds having divalent palladium are preferred. Compounds having divalent nickel include nickel chloride, nickel bromide, nickel iodide, nickel acetate, nickel acetylacetonate, nickel chloride bis (triphenylphosphine), nickel bromide bis (triphenylphosphine), nickel iodide Examples thereof include bis (triphenylphosphine), and examples of the compound having divalent palladium include palladium chloride, palladium bromide, palladium iodide, and palladium acetate.

Examples of the reducing agent include metals such as zinc and magnesium and alloys thereof (for example, alloys with copper), sodium hydride, hydrazine and derivatives thereof, and lithium aluminum hydride. If necessary, ammonium iodide, trimethylammonium iodide, triethylammonium iodide, lithium iodide, sodium iodide, potassium iodide and the like can be used in combination.
When the reducing agent is not used, the amount of the zero-valent transition metal complex used is the monomer represented by the general formula (4), the monomer represented by the general formula (5) and the general formula (6) used as necessary ( Hereinafter, it is 0.1 to 5 mol times with respect to the total amount of the reaction monomer). If the amount used is too small, the molecular weight tends to be small, so it is preferably 1.5 mole times or more, more preferably 1.8 mole times or more, and even more preferably 2.1 mole times or more. The upper limit of the amount used is preferably 5.0 moles or less because the amount of use is too large and post-treatment tends to become complicated.
Moreover, when using a reducing agent, the usage-amount of a transition metal compound is 0.01-1 mol times with respect to the total amount of a reaction monomer. If the amount used is too small, the molecular weight tends to be small, so the amount is preferably 0.03 mol times or more. The upper limit of the amount used is preferably 1.0 mole or less because the amount of use is too large and post-treatment tends to be complicated.

Moreover, the usage-amount of a reducing agent is 0.5-10 mol times normally with respect to the total amount of a reaction monomer. If the amount used is too small, the molecular weight tends to be small, so the amount is preferably 1.0 mole or more. The upper limit of the amount used is desirably 10 moles or less because if the amount used is too large, post-treatment tends to become complicated.

Examples of the ligand include 2,2′-bipyridyl, 1,10-phenanthroline, methylenebisoxazoline, N, N, N′N′-tetramethylethylenediamine, triphenylphosphine, tolylphosphine, tributylphosphine, Examples include triphenoxyphosphine, 1,2-bisdiphenylphosphinoethane, 1,3-bisdiphenylphosphinopropane, and triphenylphosphine in terms of versatility, low cost, high reactivity, and high yield. '-Bipyridyl is preferred. In particular, 2,2′-bipyridyl is preferably used because the yield of the polymer is improved when combined with bis (1,5-cyclooctadiene) nickel (0).
Moreover, when making a ligand coexist, it is about 0.2-10 mol times normally based on a metal atom basis with respect to a zerovalent transition metal complex, Preferably it is used about 1-5 mol times.

The condensation reaction is usually carried out in the presence of a solvent. Examples of such solvents include aromatic hydrocarbon solvents such as benzene, toluene, xylene, n-butylbenzene, mesitylene, and naphthalene: diisopropyl ether, tetrahydrofuran, 1,4-dioxane, diphenyl ether, dibutyl ether, tert-butyl methyl ether. , Ether solvents such as dimethoxyethane: N, N-dimethylformamide (DMF), N, N-dimethylacetamide (DMAc), N-methyl-2-pyrrolidone (NMP), hexamethylphosphoric triamide, dimethyl sulfoxide ( Aprotic polar solvents typified by amide solvents such as DMSO): aliphatic hydrocarbon solvents such as tetralin and decalin: ester solvents such as ethyl acetate, butyl acetate and methyl benzoate: chloroform, dichloro And halogenated alkyl solvents Tan, and the like.
In order to increase the molecular weight of the polyarylene polymer to be produced, it is desirable that the polyarylene polymer is sufficiently dissolved. Therefore, tetrahydrofuran, 1,4-dioxane, DMF, DMAc, which are good solvents, are desirable. DMSO, NMP, toluene and the like are preferable. These may be used in combination of two or more. Among these, DMF, DMAc, DMSO, NMP, and a mixture of two or more of these are preferably used.

The solvent is usually used in an amount of about 5 to 500 times, preferably about 20 to 100 times the total weight of the reaction monomer.
The condensation temperature is usually in the range of 0 to 250 ° C., preferably about 10 to 100 ° C., and the condensation time is usually about 0.5 to 24 hours. Among these, in order to increase the molecular weight of the polyarylene polymer to be generated, it is preferable to cause the zero-valent transition metal complex and the reaction monomer to act at a temperature of 45 ° C. or higher. The preferred working temperature is usually 45 ° C to 200 ° C, particularly preferably about 50 ° C to 100 ° C.
Further, the method of causing the zero-valent transition metal complex and the reaction monomer to act may be a method of adding one to the other or a method of adding both to the reaction vessel at the same time. When adding, it may be added all at once, but it is preferable to add little by little in consideration of heat generation, and it is also preferable to add in the presence of a solvent.
After allowing the zero-valent transition metal complex and the reaction monomer to act, the temperature is usually kept at about 45 ° C to 200 ° C, preferably about 50 ° C to 100 ° C.

Moreover, in order to change the copolymerization mode of the polyarylene polymer to block copolymerization, it can be carried out by manipulating the order of charging the monomers. For example, in order to obtain a block copolymer of the monomer represented by the general formula (4) and the monomer represented by the general formula (6), either monomer is polymerized in advance using a zero-valent transition metal complex as a catalyst. From a method of obtaining a prepolymer having Q at both ends and further polymerizing the other monomer with respect to such a prepolymer, a monomer represented by the general formula (4), and a monomer represented by the general formula (6) In each case, polymerization is performed using a zero-valent transition metal complex as a catalyst to obtain two kinds of prepolymers, and these two kinds of prepolymers are bonded to each other to obtain a block copolymer.

A block copolymer of the monomer represented by the general formula (4) and the monomer represented by the general formula (5) can be obtained in the same manner.

A conventional method can be applied to take out the polyarylene polymer produced by any of the above methods from the reaction mixture. For example, the polyarylene polymer can be precipitated by adding a poor solvent, and the target product can be taken out by filtration or the like. Moreover, it can also refine | purify by normal purification methods, such as washing with water and reprecipitation using a good solvent and a poor solvent, as needed.

Thus, the polyarylene polymer of the present invention is obtained. The obtained polyarylene polymer can be identified and quantified by IR, NMR, liquid crossgraphy, etc., and the number of each repeating structural unit in the polymer chain can be determined by NMR or the like. The molecular weight can be determined by gel permeation chromatography.
Moreover, the monomer shown by General formula (4) which is the raw material can be manufactured using a well-known method. For example, the method for introducing a sulfonic acid group via an alkyl group is not particularly limited, but a specific method is described in, for example, J.A. Amer. Chem. Soc. , 76, 5357 to 5360 (1954), a method of introducing a sulfonic acid group via an alkyl group into an aromatic ring using sultone. Further, for example, a method for introducing a sulfonic acid group via an alkoxy group is not particularly limited, but as a specific method, for example, a compound having a phenolic hydroxyl group is converted to an alkali metal compound and / or an organic base compound (for example, And an amine compound) to produce an alkali metal salt and / or an amine salt, and then reacting with a sulfonating agent such as propane sultone or sodium bromoethane sulfonate, it can be efficiently produced.

Next, the case where the polyarylene polymer of the present invention is used as a proton conductive membrane of an electrochemical device such as a fuel cell will be described.
In this case, the polyarylene polymer of the present invention is usually used in the form of a film, but there is no particular limitation on the method of converting to a film, but a method of forming a film from a solution state (solution casting method) is preferable. used.
Specifically, the polyarylene polymer is dissolved in an appropriate solvent, the solution is cast on a glass plate, and the solvent is removed to form a film. The solvent used for film formation is not particularly limited as long as it can dissolve the polyarylene polymer of the present invention and can be removed thereafter. DMF, N, N-dimethylacetamide (DMAc), N- Aprotic polar solvents such as methyl-2-pyrrolidone (NMP) and DMSO, or chlorinated solvents such as dichloromethane, chloroform, 1,2-dichloroethane, chlorobenzene and dichlorobenzene, alcohols such as methanol, ethanol and propanol, ethylene An alkylene glycol monoalkyl ether such as glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, or propylene glycol monoethyl ether is preferably used. These can be used singly, but two or more solvents can be mixed and used as necessary. Among them, DMSO, DMF, DMAc, and NMP are preferable because of high polymer solubility.

Although there is no restriction | limiting in particular in the thickness of a film, 10-300 micrometers is preferable and 20-100 micrometers is especially preferable. When the film is thinner than 10 μm, the practical strength may not be sufficient, and when the film is thicker than 300 μm, the film resistance tends to increase and the characteristics of the electrochemical device tend to deteriorate. The film thickness can be controlled by the concentration of the solution and the coating thickness on the substrate.

For the purpose of improving various physical properties of the film, plasticizers, stabilizers, mold release agents and the like used for ordinary polymers can be added to the polyarylene polymers of the present invention. In addition, other polymers can be alloyed together with the polyarylene polymer of the present invention by mixing in the same solvent and casting.
Furthermore, in fuel cell applications, it is also known to add inorganic or organic fine particles as a water retention agent in order to facilitate water management, and these known methods are applied to the polyarylene polymer of the present invention. It is also possible to apply.
Further, for the purpose of improving the mechanical strength of the film, it can be crosslinked by irradiating with an electron beam or radiation. Furthermore, there are known methods of impregnating and compounding porous films and sheets, reinforcing fibers by mixing fibers and pulp, etc., and any of these known methods can be applied. The film thus obtained can be suitably used as a proton conductive membrane for a fuel cell.

Next, the fuel cell of the present invention will be described.
The fuel cell of the present invention can be produced by bonding a catalyst and a conductive material as a current collector to both surfaces of a polymer electrolyte film.
The catalyst is not particularly limited as long as it can activate an oxidation reaction with hydrogen, methanol, or dimethyl ether as a fuel on the anode side, and can activate a reduction reaction with oxygen on the anode side. However, it is preferable to use fine particles of platinum or a platinum-based alloy. The fine particles of platinum or a platinum-based alloy are often used by being supported on particulate or fibrous carbon such as activated carbon or graphite.
A known material can be used for the conductive material as the current collector, but porous carbon woven fabric, carbon non-woven fabric, or carbon paper is preferable in order to efficiently transport the fuel to the catalyst.

For a method of bonding platinum or platinum-based alloy fine particles or carbon carrying platinum or platinum-based alloy fine particles to a porous carbon nonwoven fabric or carbon paper, and a method of bonding it to a polymer electrolyte film, see, for example, J. Org. Electrochem. Soc. : Known methods such as those described in Electrochemical Science and Technology, 1988, 135 (9), 2209 can be used.
The polyarylene polymer electrolyte of the present invention can also be used as a proton conducting material that is a component of a catalyst composition constituting a catalyst layer of a polymer electrolyte fuel cell.
The fuel cell of the present invention thus produced can be used in various forms using hydrogen gas, reformed hydrogen gas, methanol, etc. as the fuel, particularly when used in a direct methanol fuel cell using methanol. Show excellent performance.
While the embodiments of the present invention have been described above, the embodiments of the present invention disclosed above are merely examples, and the scope of the present invention is not limited to these embodiments. The scope of the present invention is defined by the terms of the claims, and further includes meanings equivalent to the description of the claims and all modifications within the scope.

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples.

[Measurement]
(1) Measurement of molecular weight The molecular weight described in the Examples is a polystyrene-equivalent number average molecular weight (Mn) and weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) under the following conditions.
GPC measuring device HLC-8220 manufactured by TOSOH
Column Example 1-2: Connected with KD-80M + KD-803 manufactured by Shodex
Example 3: Two connected AT-80Ms manufactured by Shodex, Inc. Column temperature 40 ° C.
Mobile phase solvent DMAc (LiBr added to 10 mmol / dm ³ )
Solvent flow rate 0.5mL / min
(2) Measurement of ion exchange capacity (IEC) A polyarylene polymer was dissolved in dimethyl sulfoxide to prepare a polymer electrolyte solution. This was spread on a glass plate and dried at 80 ° C. under normal pressure to obtain a polymer electrolyte membrane. This membrane was treated with 2N hydrochloric acid for 2 hours and then washed with ion-exchanged water to obtain a membrane in which ion-exchange groups were converted to the free acid type (proton type). Then, it was further dried at 105 ° C. with a halogen moisture meter, and the absolute dry weight was determined. This membrane was immersed in 5 mL of a 0.1 mol / L aqueous sodium hydroxide solution, 50 mL of ion exchange water was added, and the membrane was allowed to stand for 2 hours. Then, it titrated by adding 0.1 mol / L hydrochloric acid gradually to the solution in which this polymer electrolyte membrane was immersed, and the neutralization point was calculated | required. The ion exchange capacity was determined from the absolute dry weight and the amount of 0.1 mol / L hydrochloric acid required for the neutralization point.
(3) Measurement of proton conductivity First, ^two measurement cells each having a carbon electrode attached to one side of a silicon rubber (thickness: 200 μm) having an opening of 1 cm 2 are prepared so that the carbon electrodes face each other. The terminal of the impedance measuring apparatus was directly connected to the two cells.
Next, a polymer electrolyte membrane obtained by converting the ion exchange group obtained by the above method into a proton type is set between the two measurement cells, and the resistance between the two measurement cells is measured at a measurement temperature of 23 ° C. The value was measured.
Thereafter, the polymer electrolyte membrane was removed and the resistance value was measured again. Based on the difference between the two resistance values obtained with and without the polymer electrolyte membrane, the membrane resistance in the film thickness direction of the polymer electrolyte membrane was calculated. The proton conductivity in the film thickness direction of the polymer electrolyte membrane was calculated from the obtained membrane resistance value and film thickness. In addition, 1 mol / L dilute sulfuric acid was used as the solution to be brought into contact with both sides of the polymer electrolyte membrane.
(4) Measurement of methanol permeability coefficient Similar to the above IEC measurement method, after immersing a polymer electrolyte membrane in which ion exchange groups are converted into free acid type (proton type) in a 10 wt% methanol aqueous solution for 2 hours A polymer electrolyte membrane is sandwiched in the center of an H-shaped diaphragm cell consisting of cell A and cell B, a 10 wt% methanol aqueous solution is placed in cell A, and pure water is placed in cell B. The methanol concentration in the cell B after t (sec) was analyzed, and the methanol permeability coefficient D (cm ² / sec) was determined by the following equation.
D = {(V * l) / (A * t)} * ln {(C1-Cm) / (C2-Cn)}
here,
V: volume of liquid in cell B (cm ³ ),
l: thickness of polymer electrolyte membrane (cm),
A: Cross-sectional area (cm ² ) of the polymer electrolyte membrane,
t: Time (sec)
C 1: concentration of methanol in cell B at time t ₁ (mol / cm ³ ),
C 2: methanol concentration in cell B at time t ₂ (mol / cm ³ ),
C m: methanol concentration in cell A at time t ₁ (mol / cm ³ ),
C n: methanol concentration in cell A at time t ₂ (mol / cm ³ ),
Since the methanol permeation amount was sufficiently small, V was determined to be a constant value with the initial pure water capacity, and the initial concentration (10 wt%) with Cm = Cn.

Synthesis example 1
(Synthesis of Monomer A (3- (2,5-dichlorophenoxy) propanesulfonic acid sodium salt))
Under an argon atmosphere, DMAc 150 ml, toluene 75 ml, 2,5-dichlorophenol 24.15 g (148.2 mmol) and sodium carbonate 47.10 g (444.4 mmol) were placed in a flask, and heated and stirred to azeotrope conditions of toluene and water. After dehydration below, toluene was distilled off. After allowing to cool to room temperature, 50.00 g (222.2 mmol) of sodium 3-bromopropanesulfonate was added, the temperature was raised to 100 ° C., and the mixture was stirred at the same temperature for 10 hours. After allowing to cool, the solid was removed by suction filtration, a large amount of chloroform was added to the obtained filtrate, and the precipitated white solid was separated by filtration. Furthermore, 35.2 g of sodium 3- (2,5-dichlorophenoxy) propanesulfonate was obtained by a recrystallization method.

Synthesis example 2
(Synthesis of monomer B (3- (2,5-dichlorophenoxy) ethanesulfonic acid sodium salt))
Under an argon atmosphere, DMAc 150 ml, toluene 75 ml, 2,5-dichlorophenol 11.84 g (72.6 mmol), sodium carbonate 23.10 g (217.9 mmol) were placed in a flask, and heated and stirred to azeotrope conditions of toluene and water. After dehydration below, toluene was distilled off. After allowing to cool to room temperature, 23.00 g (109.0 mmol) of sodium 2-bromoethanesulfonate was added, the temperature was raised to 100 ° C., and the mixture was stirred at the same temperature for 10 hours. After allowing to cool, the solid was removed by suction filtration, a large amount of chloroform was added to the obtained filtrate, and the precipitated white solid was separated by filtration. Furthermore, 14.3 g of sodium 3- (2,5-dichlorophenoxy) ethanesulfonate was obtained by recrystallization.

Synthesis example 3
(Synthesis of monomer C (sodium 3- (2,5-dichlorophenoxy) butanesulfonate))
Under an argon atmosphere, DMAc 150 ml, toluene 75 ml, 2,5-dichlorophenol 20.00 g (122.7 mmol), sodium carbonate 39.01 g (368.1 mmol) were placed in a flask, and the mixture was heated and stirred to azeotrope conditions of toluene and water. After dehydration below, toluene was distilled off. After allowing to cool to room temperature, 25.06 g (184.1 mmol) of butane sultone was added, the temperature was raised to 80 ° C., and the mixture was stirred at the same temperature for 10 hours. After allowing to cool, the solid was removed by suction filtration, a large amount of chloroform was added to the obtained filtrate, and the precipitated white solid was separated by filtration. Further, 38.7 g of sodium 3- (2,5-dichlorophenoxy) butanesulfonate was obtained by a recrystallization method.

（住友化学製スミカエクセルＰＥＳ５２００Ｐ、Ｍｎ＝５．４４×１０⁴、Ｍｗ＝１．２３×１０⁵）５．９２ｇ、２，２’−ビピリジル１９．７０ｇ（１２６．１７ｍｍｏｌ）を入れて攪拌し、６０℃に昇温した。次いで、これにニッケル（０）ビス（シクロオクタジエン）３１．５５ｇ（１１４．７０ｍｍｏｌ）を加え、８０℃に昇温し、同温度で２０時間攪拌した。放冷後、反応液を大量の４Ｎ塩酸に注ぐことによりポリマーを析出させ、濾別し、濾液が中性になるまで水洗を行なった後、減圧乾燥することにより、下記一般式（１０）で示されるポリアリーレン系高分子９．５０ｇを得た。ＩＥＣは１．７３ｍｅｑ／ｇであり、ＩＥＣから求められた繰り返し構造単位の比率をａ／（ａ＋（（ｎ＋１）×ｂ）で表すと、０．３７であった。また、上記の方法で求めたプロトン伝導度とメタノール透過係数を表−１に示す。また、上記の方法で求めたプロトン伝導度とメタノール透過係数を表−１に示す（なお、括弧内は測定条件下での高分子電解質膜の膜厚を示す）。
Ｍｎ＝２２００００、Ｍｗ＝３９６０００
ＩＥＣ＝１．７３ ｍｅｑ／ｇ

Example 1
In an argon atmosphere, in a flask, 195 ml of DMSO, 10.00 g (32.56 mmol) of the monomer A obtained in Synthesis Example 1, and the following polyethersulfone having a terminal chloro type

(Sumitomo Chemical Sumika Excel PES5200P, Mn = 5.44 × 10 ⁴ , Mw = 1.23 × 10 ⁵ ) 5.92 g, 2,2′-bipyridyl 19.70 g (126.17 mmol) was added and stirred. The temperature was raised to 60 ° C. Next, 31.55 g (114.70 mmol) of nickel (0) bis (cyclooctadiene) was added thereto, the temperature was raised to 80 ° C., and the mixture was stirred at the same temperature for 20 hours. After allowing to cool, the reaction solution is poured into a large amount of 4N hydrochloric acid to precipitate a polymer, filtered, washed with water until the filtrate becomes neutral, and then dried under reduced pressure to give the following general formula (10). 9.50 g of the polyarylene polymer shown was obtained. The IEC was 1.73 meq / g, and the ratio of the repeating structural units determined from IEC was 0.37 when expressed as a / (a + ((n + 1) × b). The proton conductivity and methanol permeability coefficient are shown in Table 1. The proton conductivity and methanol permeability coefficient obtained by the above method are shown in Table 1 (in parentheses are polymer electrolytes under measurement conditions) Indicates the film thickness).
Mn = 220,000, Mw = 396000
IEC = 1.73 meq / g

（住友化学製スミカエクセルＰＥＳ５２００Ｐ、Ｍｎ＝５．４４×１０⁴、Ｍｗ＝１．２３×１０⁵）２．２７ｇ、２，２’−ビピリジル１０.３１ｇ（６５.９９ｍｍｏｌ）を入れて攪拌し、６０℃に昇温した。次いで、これにニッケル（０）ビス（シクロオクタジエン）１６．５０ｇ（５９．９９ｍｍｏｌ）を加え、８０℃に昇温し、同温度で１７時間攪拌した。放冷後、反応液を大量の４Ｎ塩酸に注ぐことによりポリマーを析出させ、濾別し、濾液が中性になるまで水洗を行なった後、減圧乾燥することにより、下記一般式（１１）で示されるポリアリーレン系高分子４．７３ｇを得た。ＩＥＣは２.３５ｍｅｑ／ｇであり、ＩＥＣから求められた繰り返し構造単位の比率をａ／（ａ＋（（ｎ＋１）×ｂ）で表すと、０．４７であった。また、上記の方法で求めたプロトン伝導度とメタノール透過係数を表−１に示す（なお、括弧内は測定条件下での高分子電解質膜の膜厚を示す）。
Ｍｎ＝９３０００、Ｍｗ＝１８６０００

Example 2
Under an argon atmosphere, in a flask, 86 ml of DMSO, 5.00 g (17.06 mmol) of monomer B obtained in Synthesis Example 2, and the following polyethersulfone which is terminal chloro type

(Sumitomo Chemical Sumika Excel PES5200P, Mn = 5.44 × 10 ⁴ , Mw = 1.23 × 10 ⁵ ) 2.27 g, 2,2′-bipyridyl 10.31 g (65.999 mmol) was added and stirred. The temperature was raised to 60 ° C. Next, 16.50 g (59.99 mmol) of nickel (0) bis (cyclooctadiene) was added thereto, the temperature was raised to 80 ° C., and the mixture was stirred at the same temperature for 17 hours. After allowing to cool, the reaction solution is poured into a large amount of 4N hydrochloric acid to precipitate a polymer, filtered, washed with water until the filtrate is neutral, and then dried under reduced pressure to give the following general formula (11). 4.73 g of the polyarylene polymer shown was obtained. The IEC was 2.35 meq / g, and the ratio of the repeating structural units obtained from IEC was 0.47 when expressed as a / (a + ((n + 1) × b). The proton conductivity and methanol permeability coefficient are shown in Table 1 (note that the values in parentheses indicate the thickness of the polymer electrolyte membrane under the measurement conditions).
Mn = 93000, Mw = 186000

（住友化学製スミカエクセルＰＥＳ５２００Ｐ、Ｍｎ＝５．４４×１０⁴、Ｍｗ＝１．２３×１０⁵）１．７３ｇ、２，２’−ビピリジル８．０６ｇ（５１．６２ｍｍｏｌ）を入れて攪拌し、６０℃に昇温した。次いで、これにニッケル（０）ビス（シクロオクタジエン）１２．９１ｇ（４６.９２ｍｍｏｌ）を加え、８０℃に昇温し、同温度で４時間攪拌した。放冷後、反応液を大量の４Ｎ塩酸に注ぐことによりポリマーを析出させ、濾別し、濾液が中性になるまで水洗を行なった後、減圧乾燥することにより、下記一般式（１２）で示されるポリアリーレン系高分子５．２１ｇを得た。ＩＥＣは２.６７ｍｅｑ／ｇであり、ＩＥＣから求められた繰り返し構造単位の比率をａ／（ａ＋（（ｎ＋１）×ｂ）で表すと、０．６１であった。また、上記の方法で求めたプロトン伝導度とメタノール透過係数を表−１に示す（なお、括弧内は測定条件下での高分子電解質膜の膜厚を示す）。
Ｍｎ＝１３００００、Ｍｗ＝２５００００

Example 3
Under an argon atmosphere, in a flask, 85 ml of DMSO, 5.00 g (15.57 mmol) of the monomer C obtained in Synthesis Example 3, and the following polyethersulfone which is a terminal chloro type

(Sumitomo Chemical SUMIKAEXCEL PES5200P, Mn = 5.44 × 10 ⁴ , Mw = 1.23 × 10 ⁵ ) 1.73 g, 2,2′-bipyridyl 8.06 g (51.62 mmol) was added and stirred. The temperature was raised to 60 ° C. Next, 12.91 g (46.92 mmol) of nickel (0) bis (cyclooctadiene) was added thereto, the temperature was raised to 80 ° C., and the mixture was stirred at the same temperature for 4 hours. After allowing to cool, the reaction solution is poured into a large amount of 4N hydrochloric acid to precipitate a polymer, filtered, washed with water until the filtrate becomes neutral, and then dried under reduced pressure to give the following general formula (12). 5.21 g of the polyarylene polymer shown was obtained. The IEC was 2.67 meq / g, and the ratio of repeating structural units determined from IEC was 0.61 when expressed as a / (a + ((n + 1) × b). The proton conductivity and methanol permeability coefficient are shown in Table 1 (note that the values in parentheses indicate the thickness of the polymer electrolyte membrane under the measurement conditions).
Mn = 130,000, Mw = 250,000

Evaluation of fuel cell characteristics Similar to the IEC measurement method, a polymer electrolyte membrane in which an ion exchange group is converted into a free acid type (proton type) is used, and the membrane is compliant with the method described in JP-A-2004-319139. -An electrode assembly was prepared. However, as the electrode ink, a platinum ruthenium catalyst (manufactured by NE CHEMCAT, Pt / Ru = 60/40 g / g) supported on carbon and an Aldrich 5 wt% Nafion solution (solvent: water and A mixture of lower alcohols) and ethanol added to the cathode, platinum catalyst supported by carbon (manufactured by NE CHEMCAT) on the cathode, and 5 wt% Nafion solution (solvent: water and lower alcohol) made by Aldrich. The ink was directly applied to the film using an ink obtained by adding ethanol to the mixture) so that the amount of platinum was 1.0 g / cm ² for both electrodes. As the diffusion layer, carbon paper was used for the anode and carbon cloth was used for the cathode. The joined body was kept at 40 ° C., and a 10 wt% methanol aqueous solution was flowed to the anode and non-humidified air gas was flowed to the cathode, and the power generation characteristics were measured.

Example 4
Using the polyarylene polymer obtained in Example 2, a membrane-electrode assembly was prepared by the above method, and the power generation characteristics were measured. The results are shown in Table-2.

Example 5
Using the polyarylene polymer obtained in Example 3, a membrane-electrode assembly was prepared by the above method, and power generation characteristics were measured. The results are shown in Table-2.

Comparative Example 1
Using Nafion 115 (manufactured by Du Pont), a membrane-electrode assembly was prepared by the above method, and power generation characteristics were measured. The results are shown in Table-2.

Claims (10)

A polymer electrolyte for a direct methanol fuel cell, characterized by having a repeating structural unit represented by the following general formula (1).

(In the formula, X represents a direct bond, —O—, —S—, —SO—, —SO ₂ — or —CO—, and Y represents a direct bond, a divalent or trivalent aromatic group. R ¹ and R ² each independently represent a hydrogen atom or a fluorine atom, i represents a number of 0 to 3, k represents a number of 1 to 12, and l represents that Y is a direct bond or 1 represents a divalent aromatic group, and 2 represents a trivalent aromatic group, and R ³ represents a sulfonic acid group, an alkyl group having 1 to 10 carbon atoms, or 6 to 6 carbon atoms. 18 represents an optionally substituted aryl group, and when there are a plurality of R ³ , they may be the same or different.) The polymer electrolyte for a direct methanol fuel cell according to claim 1, wherein 90% or more of the repeating structural units represented by the general formula (1) are bonded at the para position to constitute a main chain. The polymer electrolyte for a direct methanol fuel cell according to claim 1 or 2, further comprising a repeating structural unit represented by the following general formula (2) and / or (3).

(In the formula, Ar ¹ and Ar ² independently represent a divalent group having an aromatic ring, and the aromatic ring in the divalent group is an alkyl group having 1 to 10 carbon atoms or a carbon number. 6 to 18 may be substituted with an aryl group, Z represents any of —O—, —SO ₂ —, and —CO—, and when there are a plurality of Z, they may be the same or different. M is an integer of 1 or more, n is an integer of 0 or more, and R ⁴ is an alkyl group having 1 to 10 carbon atoms or an optionally substituted aryl group having 6 to 18 carbon atoms. Or an acyl group having 2 to 20 carbon atoms, and when there are a plurality of R ^{4 s} , they may be the same or different, and p represents a number of 0 to ^4. ) 90% or more of the repeating structural units represented by the general formula (1) and the repeating structural units represented by the general formula (3) in the main chain and represented by the general formula (3) The polymer electrolyte for a direct methanol fuel cell according to claim 3, wherein the polymer electrolyte is bonded at a para position. Y is a direct bond, The polymer electrolyte for direct methanol fuel cells in any one of Claims 1-4 characterized by the above-mentioned. i is 0, The polymer electrolyte for direct methanol fuel cells in any one of Claims 1-5. The polymer electrolyte for a direct methanol fuel cell according to any one of claims 1 to 6, wherein the ion exchange capacity is 0.5 meq / g to 4 meq / g. At least one structure selected from a block consisting of a repeating structural unit represented by general formula (1), a repeating structural unit represented by general formula (2), and a repeating structural unit represented by general formula (3) The polymer electrolyte for a direct methanol fuel cell according to any one of claims 1 to 7, which is a block copolymer having a unit block. A polymer electrolyte membrane for a direct methanol fuel cell, comprising the polymer electrolyte according to claim 1. A direct methanol fuel cell using the polymer electrolyte membrane for a direct methanol fuel cell according to claim 9.