JP2003292608A - Aromatic polymer, its producing method and its use - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new polymer compound which is high in proton conduction and suitable for a polymeric electrolyte for a fuel cell. <P>SOLUTION: The polymer comprises a repeating unit represented by formula (1) [wherein m is an integer of 1-3, n is an integer of 1-6, M is hydrogen, an alkali metal or ammonium, R is H, SO<SB>3</SB>H, F, a lower alkyl group or a lower alkoxy group, A is a direct bond or a bivalent group of formula (4), (5) or (6), and B is a direct bond of a group of formula (7) or (8) (wherein R<SP>1</SP>and R<SP>2</SP>are each independently H, a lower alkyl group or a lower fluoroalkyl group; #means bonding to the benzene ring of formula (1); L is a direct bond, O or S; m is the same as described above; m<SP>1</SP>and m<SP>2</SP>are each an integer and summed to be an integer of 1-3; * means bonding to -SO<SP>-</SP><SB>3</SB>M<SP>+</SP>; and a benzene ring may be optionally substituted)]. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aromatic polymer, and more particularly to a polymer having an aromatic main chain, to which a sulfonic acid group is bonded via a linking group. The present invention relates to an aromatic polymer.

[0002]

2. Description of the Related Art Polymers having proton conductivity, that is, polymer electrolytes are used as diaphragms for electrochemical devices such as primary batteries, secondary batteries, and solid polymer fuel cells. ing. For example,
Perfluorosulfonic acid-based materials such as Nafion (registered trademark of DuPont) have been mainly used conventionally because of their excellent properties as fuel cells. However, it has been pointed out that this material is very expensive, has a low heat resistance, and has a low film strength and is not practical without some reinforcement.

Under these circumstances, the development of inexpensive polymer electrolytes that can replace the above-mentioned polymer electrolytes has been activated in recent years. Among them, polymers that have sulfonic acid groups introduced into aromatic polyethers that have excellent heat resistance and high film strength, that is, aromatic chains whose main chain is a sulfonic acid group directly bonded to this main chain Are seen as promising.
For example, sulfonated polyetherketone type
No. 502249), sulfonated polyether sulfone system (JP-A-10-45913, JP-A-10-
The polymer of JP-A-21943) has been proposed. However, these are not in a state where the proton conductivity and the like are sufficiently satisfied, and improvement in this point has been desired.

An object of the present invention is to provide a novel polymer compound having high proton conductivity and suitable for a polymer electrolyte for fuel cells.

The inventors of the present invention have conducted extensive studies to improve the above-mentioned problems of conventional polymer electrolytes, and as a result, the main chain is aromatic and the sulfonic acid group is a linking group on the main chain. It was found that a specific polymer, which is bound via a polymer, can achieve its purpose and has excellent characteristics as a proton conductive membrane for fuel cells and the like, and further completed various studies to complete the present invention. did.

[0006]

That is, the present invention is based on the general formula (1) (In the formula, m represents an integer of 1 to 3, n represents an integer of 1 to 6, M represents a hydrogen atom, an alkali metal or ammonium. R represents H, SO ₃ H, F, a lower alkyl group or a lower alkyl group. Represents an alkoxy group, A is a direct bond,
In the divalent group of (5) or (6), B represents a direct bond or a group of the following formula (7) or (8). )

[0007] (In the formula, R ¹ and R ^{2 each} independently represent H, a lower alkyl group or a lower fluoroalkyl group. # Represents a bond to the benzene ring of the formula (1). L represents a direct bond, O Or S, and m has the same meaning as described above, m ¹ , m
² represents an integer, and the sum thereof is an integer of 1 to 3. * Is -SO ^- it represents that it is bound binds to ₃ M ^+. The benzene ring may be substituted. )) It has a practically excellent polymer having a repeating structure represented by the formula (1), a method for producing the same, and an application thereof.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
The polymer of the present invention has a repeating structure represented by the general formula (1), and m represents an integer of 1 to 3 and n represents an integer of 1 to 6. n is preferably 4 to 6. M represents a hydrogen atom, an alkali metal or ammonium. Here, as the alkali metal, for example,
Examples thereof include lithium, sodium and potassium. When M is used as the polymer electrolyte for fuel cells, M is preferably a hydrogen atom.

R represents H, SO ₃ H, F, a lower alkyl group or a lower alkoxy group. Here, examples of the lower alkyl group include an alkyl group having 1 to 6 carbon atoms such as methyl group, ethyl group and propyl group, and examples of the lower alkoxy group include 1 to 6 carbon atoms such as methoxy group and ethoxy group.
6 alkoxy groups can be mentioned. Moreover, R may have two or more, and in that case, those substituents may mutually differ. Among them, R is preferably SO ₃ H or F.

A represents a direct bond or a divalent group of the above formula (4), (5) or (6). These divalent groups may have a substituent, and examples of the substituent include a hydroxyl group such as methyl, ethyl, 2-propyl, t-butyl, hydroxymethyl and trifluoromethyl, and halogen. A linear or branched alkyl group which may be substituted; a linear or branched alkoxy group which may be substituted with a halogen atom such as methoxy, ethoxy or trifluoromethoxy; phenyl, methylphenyl, methoxy Alkyl such as phenyl, biphenyl, phenoxyphenyl, chlorophenyl, sulfophenyl and the like, phenyl group which may be substituted with alkoxy, phenyl, phenoxy, halogen, sulfonic acid and the like; alkyl such as phenoxy, methylphenoxy, methoxyphenoxy and sulfophenoxy, Place with alkoxy, sulfonic acid, etc. Optionally substituted phenoxy group; alkyloxycarbonyl group such as ethoxycarbonyl; alkylcarbonyloxy group such as ethylcarbonyloxy; aminocarboxy group or N-alkylaminocarboxy group; nitrogen atom such as amino group and dimethylamino group is alkyl An amino group which may be substituted with a group; a halogen atom such as fluorine, chlorine, bromine and iodine; a ureido group; an acylamino group; a carboxyl group; a hydroxy group; a cyano group; a sulfonic acid group;
Aminosulfonyl group etc. are mentioned.

Examples of the divalent group represented by the formula (4) include 1,2-phenylene, 1,3-phenylene, 1,4-phenylene and 3-methyl-1,2-phenylene groups. , 3-ethyl-1,2-phenylene group, 3,6-dimethyl-1,2-phenylene group, 2-methyl-1,3-
Phenylene group, 2-ethyl-1,3-phenylene group, 5
-Methyl-1,3-phenylene group, 5-bromo-1,3
-Phenylene group, 2-methyl-1,4-phenylene group, 2
-Ethyl-1,4-phenylene group, 2,6-dimethyl-
1,4-phenylene group, 2-phenyl-1,4-phenylene group, 2,3-diphenyl-1,4-phenylene group and the like can be mentioned.

Examples of the divalent group represented by the formula (5) include, for example, And other phenylene ether groups. Also, formula (6)
In the divalent group represented by, R ¹ and R ² independently represent H, a lower alkyl group or a lower fluoroalkyl group, and the lower alkyl group has the same carbon number of 1 to 6 as described above. An alkyl group is mentioned. Examples of the lower fluoroalkyl group include fluoroalkyl groups having 1 to 6 carbon atoms such as trifluoromethyl and pentafluoromethyl. Examples of the divalent group represented by the formula (6) include, for example, 1,4-phenylene methylene groups such as

Of these, as A, a direct bond, m-phenylene group, p-phenylene group, p-phenyleneoxy group, m-phenylenemethylene group, 1,4-phenylenemethylene group and the like are preferable.

In the formula (1), B represents a direct bond or a group of the formula (7) or (8). These groups may have a substituent, and examples of such a substituent include A
Substituents similar to the above can be mentioned. Here, as the group represented by the formula (7), for example, in addition to the same divalent group as in the formula (4), And other monocyclic aromatic groups.

In the group represented by the formula (8), L represents a direct bond, O or S, m ¹ and m ² each represent an integer, and the sum thereof is an integer of 1 to 3. Examples of the group represented by formula (8) include And the like bicyclic aromatic groups.

Among them, B is a direct bond. Etc. are preferred.

The polymer of the present invention has the above formula (1).
The repeating structure is represented by the formula (1), and the repeating structure is usually present in the range of 1 to 100% of all repeating units. It is preferably 10 to 70%. The total number of repeating units in the polymer is usually 10 to 10
It is in the range of 0000, and preferably in the range of 100 to 10,000. In the polymer of the present invention, the above formula (1)
In addition to the repeating structure represented by (In the formula, Z represents SO ₂ or CO.), And may have a repeating structure. In this case, the arrangement of these repeating units may be random, alternating, or block.

A preferred embodiment of the present invention is, for example, formula (2 ') (In the formula, x and y represent the number of each repeating structure, and x
And y are 10 to 100,000, and x is 0 to 100 times y. The repeating structure may be random, alternating, or block. Z, A, R, B, M, m and n have the same meanings as described above. ).

The polymer of the present invention may be represented by the formula (3) as a monomer. (In the formula, X ′ represents a hydrogen atom, a chloro group, a bromo group, an iodo group, or —A—OH, and m, n, M, R, A, B
Represents the same meaning as described above. ) It can manufacture by using the aromatic compound shown by. Here, when X ′ is a hydrogen atom, the aromatic compound represented by the formula (3) is, for example, (methoxyaryl) alkyl bromide,
The aryl bromide can be produced by a method such as Grignard coupling according to the above-mentioned known method, followed by demethylation. When X ′ is a halogen atom, for example, when it is a chlorine atom or a bromine atom,
The aromatic compound of the formula (3) in which X ′ is a hydrogen atom can be produced by a method such as chlorination or bromination according to a known method such as treatment with chlorine or bromine. In the case of an iodine atom, the aromatic compound of the formula (3), in which X ′ is a bromine atom, is treated with n-butyllithium to generate aryllithium, and then treated with iodine. You can

As the aromatic compound of the formula (3) in which X'is A-OH, for example, (dimethoxyaryl) alkyl bromide and aryl bromide can be prepared by a known method (Organic Sy).
ntheses, Collective Volume 6, 407, etc.) followed by Grignard coupling, followed by demethylation and the like (Reference: JA)
m. Chem. Soc. , 115, 11735 (199
3)). In addition, a known method of reacting (dimethoxyaryl) alkyl bromide with sodium sulfite (Japanese Patent Laid-Open Publication No. 9-163242)
It can also be produced by converting the compound into a (dimethoxyaryl) alkyl sulfonate according to JP-A-295962) and then demethylating it by the above-described demethylation method.

The polymer of the present invention can be produced by using the above-mentioned monomers. For example, when X ′ is a hydrogen atom, a method of producing an intended product by an oxidative polymerization method can be mentioned. Further, a method in which a corresponding homopolymer is obtained by an oxidative polymerization method using a monomer corresponding to m of 0 and the resulting homopolymer is sulfonated may also be employed. The oxidative polymerization can be based on the method described in JP 2001-250567 A, for example. When X ′ is a chloro group, a bromo group, an iodo group, or the like, a method of producing the target product by polymerization in which an Ullmann-type reaction is a basic reaction can be mentioned. A method in which a corresponding homopolymer is obtained by polymerizing a monomer corresponding to m = 0 and sulfonation is also applicable. The polymerization can be performed, for example, with "POLYMER SYNTHESES Volum
e 1 ”(Stanley R. Sandler, Wolf Karo, Academic Pre
ss, Inc. 1974) pp. 239, "5. POLYPHENYLENE ETHER
The method described in "S" can be followed.

When X'is A-OH, a method for producing the desired product by copolymerizing this with a dihalogeno aromatic compound or by copolymerizing this with a dihalogeno aromatic compound and an aromatic diol compound, etc. Is mentioned. Also, a monomer corresponding to m = 0 is used, and this is copolymerized with a dihalogenoaromatic compound or with this and a dihalogenoaromatic compound and an aromatic diol compound to obtain a corresponding copolymer. It is also possible to employ a method of sulfonation.

The above dihalogeno aromatic compound may be a monomer or a polymer, or both may be used. Here, as the monomer, for example,
1,2-dichlorobenzene, 1,3-dichlorobenzene, 1,4-dichlorobenzene, 1,2-dibromobenzene, 1,3-dibromobenzene, 1,4-dibromobenzene, 1,2-diiodobenzene, Monocyclic dihalogeno aromatic compounds such as 1,3-diiodobenzene and 1,4-diiodobenzene, 2,2′-difluorodiphenyl sulfone, 2,3′-difluorodiphenyl sulfone,
2,4'-difluorodiphenyl sulfone, 3,3'-difluorodiphenyl sulfone, 3,4'-difluorodiphenyl sulfone, 4,4'-difluorodiphenyl sulfone, 2,2'-dichlorodiphenyl sulfone, 2,
3'-dichlorodiphenyl sulfone, 2,4'-dichlorodiphenyl sulfone, 3,3'-dichlorodiphenyl sulfone, 3,4'-dichlorodiphenyl sulfone, 4,
4'-dichlorodiphenyl sulfone, 2,2'-difluorodiphenyl sulfone, 2,3'-difluorodiphenyl sulfone, 2,4'-difluorobenzophenone,
3,3'-difluorobenzophenone, 3,4'-difluorobenzophenone, 4,4'-difluorobenzophenone, 2,2'-dichlorobenzophenone, 2,3'-
Dichlorobenzophenone, 2,4'-dichlorobenzophenone, 3,3'-dichlorobenzophenone, 3,4'-
Examples thereof include bicyclic dihalogeno aromatic compounds such as dichlorobenzophenone and 4,4′-dichlorobenzophenone. Among these, 4,4'-difluorodiphenyl sulfone, 4,4'-dichlorodiphenyl sulfone,
4,4'-difluorobenzophenone and 4,4'-dichlorobenzophenone are preferably used.

The polymer as a dihalogenoaromatic compound is not particularly limited as long as it has two halogen groups at the ends and has a main chain mainly composed of an aromatic ring. For example, polyphenylene ether type Polymers such as polynaphthylene, polyphenylene, polyethersulfone, polyphenylene sulfide, polyetheretherketone, polyetherethersulfone, polysulfone, polyetherketone, and polybenzimidazole. Among these, polyphenylene ether-based, polynaphthylene-based, polyphenylene-based, polyether sulfone-based polymers and the like are particularly preferably used.

The aromatic diol compound may be a monomer or a high molecular weight diol, or both of them may be used. Examples of such a monomer include 4,4′-dihydroxydiphenyl sulfone and 4,4′-
Examples thereof include dihydroxybenzophenone, catechol, resorcinol, p-hydroquinone, 4,4′-biphenol and bisphenol A. The polymer diol is not particularly limited as long as the main chain is mainly composed of an aromatic ring and has two hydroxyl groups at the terminals, and examples thereof include polyphenylene ether-based, polynaphthylene-based, polyphenylene-based, and polyether. Polymers such as sulfone-based, polyphenylene sulfide-based, polyether ether ketone-based, polyether ether sulfone-based, polysulfone-based, polyether sulfone-based, polyether ketone-based, and polybenzimidazole-based polymers are mentioned. Among them, especially polyphenylene ether type, polynaphthylene type,
Polyphenylene-based and polyether sulfone-based polymers are preferably used.

The above dihalogenoaromatic compound, aromatic diol compound and the like, and X'in the formula (3) are A
Copolymerization with an aromatic compound in the case of —OH can be based on a known method carried out in the presence of an alkali. Here, as the alkali, a known one having polymerization activity can be used. Alkali metal hydroxides and alkali metal carbonates are preferably used. Among them, potassium carbonate is preferably used. Usually, it is preferable to use the alkali in an amount equivalent to the hydroxyl group or in a small excess. Further, as the solvent, a mixed solvent of a solvent having an azeotropic dehydration property and a polar solvent is used. As the polar solvent, those having the highest possible solubility of the aromatic compound of the formula (3), the dihalogenoaromatic, the polymer to be produced, etc. are preferable, and examples thereof include aromatic hydrocarbon solvents, ether solvents, ketone solvents, amide solvents. ,
Examples thereof include sulfone-based solvents and sulfoxide-based solvents, but dimethyl sulfoxide, sulfolane, N, N-dimethylformamide, N, N-dimethylacetamide, N
-Methylpyrrolidone, N, N'-dimethylimidazolidinone and the like are preferably used. These are toluene, for the purpose of azeotropically removing water by-produced when phenoxide is produced by the reaction of the aromatic compound of the formula (3) and an alkali,
It is used as a mixture with a solvent having an azeotropic dehydration property such as benzene.

The reaction temperature of the polymerization reaction is preferably 20 ° C to 250 ° C, more preferably 50 ° C to 200 ° C. The molar ratio of the dihalogeno aromatic compound to the aromatic compound of formula (3) is usually in the range of 90: 110 to 110: 90,
Particularly preferably, it is 97: 103 to 103: 97. When the dihalogeno aromatic compound is in excess, the end of the polymer main chain has a high proportion of halogen, and when the aromatic compound of the formula (3) is in excess, the end of the polymer main chain has a high proportion of hydroxyl group. When an aromatic diol compound is used, when the total amount of the aromatic compound of the formula (3) and the dihalogeno aromatic compound are copolymerized with the dihalogeno aromatic compound by the above formula (3) alone. It is preferable to adjust so that it becomes similar to.

When a monomer corresponding to m of 0 is used, the copolymer obtained as described above is sulfonated. Examples of the sulfonating agent include concentrated sulfuric acid, chlorosulfuric acid, fuming sulfuric acid, etc. The publicly known sulfonating agent can be used. Among these, concentrated sulfuric acid is preferably used because it is easy to selectively introduce a sulfonic acid group into a repeating unit having a higher electron density (JP 2001-250567 A).
Gazette).

Thus, the polymer of the present invention is obtained,
The polymer of the present invention can be used as a polymer electrolyte for fuel cells and the like. In this case, it is usually used in the form of a film.
The method of converting the polymer of the present invention into a polymer electrolyte membrane is not particularly limited, but a method of forming a membrane from a solution state (solution casting method) is preferable. Specifically, the polymer of the present invention is dissolved in a suitable solvent, the solution is cast and coated on a glass plate,
A polymer electrolyte membrane can be produced by removing the solvent. The solvent used for film formation is not particularly limited as long as it can dissolve aromatic polymer phosphonic acids and can be removed thereafter, and examples thereof include N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-
Aprotic polar solvents such as pyrrolidone and dimethyl sulfoxide, chlorine-based solvents such as dichloromethane, chloroform, 1,2-dichloroethane, chlorobenzene and dichlorobenzene, alcohols such as methanol, ethanol and propanol, ethylene glycol monomethyl ether, ethylene glycol Alkylene glycol monoalkyl ethers such as monoethyl ether, propylene glycol monomethyl ether and propylene glycol monoethyl ether are preferably used. These may be used alone, or may be used as a mixture of two or more kinds of solvents, if necessary. Among them, dimethylformamide, dimethylacetamide, N-methylpyrrolidone,
Dimethyl sulfoxide and the like are preferable because they have high polymer solubility.

When the polymer of the present invention is used in a fuel cell, it is also possible to use a polymer electrolyte composite membrane obtained by compositing the polymer with a support. Here, the support serves as a base material for impregnating the polymer electrolyte of the present invention, and is mainly used for further improving the strength, flexibility and durability of the polymer electrolyte of the present invention.
Therefore, as long as it meets the above-mentioned purpose of use, it can be used regardless of its shape or material such as fibril shape or porous membrane shape, but keep in mind that it is preferably used as a membrane of a solid polymer electrolyte fuel cell. It is very effective to use a porous film when placed in the.

The porous film used for the purpose has a film thickness of usually 1 to 100 μm, preferably 3 to 30 μm, more preferably 5 to 20 μm, and a pore size of usually 0.01 to 10 μm.
μm, preferably 0.02 to 7 μm, porosity is usually 20
~ 98%, preferably 30-95%. If the thickness of the porous support film is too thin, the effect of reinforcing the strength after compounding or the reinforcing effect of imparting flexibility and durability becomes insufficient, and gas leakage (cross leak) easily occurs. On the other hand, if the film thickness is too thick, the electric resistance will be high, and the obtained composite membrane is not preferable as a diaphragm for a polymer electrolyte fuel cell. If the pore size is too small, impregnation with the polymer solid electrolyte becomes very difficult, and if too large, the reinforcing effect on the polymer solid electrolyte tends to be weak. If the porosity is too small, the resistance as a solid electrolyte membrane increases, and if it is too large, the strength of the porous membrane itself generally weakens and the reinforcing effect decreases.
Further, as the material of the porous support film, from the viewpoint of heat resistance,
From the viewpoint of reinforcing the physical strength, an aliphatic polymer or a fluorine-containing polymer is preferable.

The aliphatic polymer which can be preferably used includes, but is not limited to, polyethylene, polypropylene, ethylene-propylene copolymer and the like. As the fluorine-containing polymer, a known thermoplastic resin having at least one carbon-fluorine bond in the molecule is used. Usually, an aliphatic polymer having a structure in which all or most of the hydrogen atoms are replaced by fluorine atoms is preferably used.

Examples of fluorine-containing polymers that can be preferably used include polytrifluoroethylene, polytetrafluoroethylene, polychlorotrifluoroethylene, poly (tetrafluoroethylene-hexafluoropropylene),
Examples include poly (tetrafluoroethylene-perfluoroalkyl ether) and polyvinylidene fluoride.
It is not limited to these. Of these, in the present invention, polytetrafluoroethylene and poly (tetrafluoroethylene-hexafluoropropylene) are preferable,
Polytetrafluoroethylene is particularly preferable. Further, these fluororesins preferably have an average molecular weight of 100,000 or more in terms of good mechanical strength.

When the polymer electrolyte membrane or composite membrane of the present invention is used in a fuel cell, the thickness of the membrane is not particularly limited, but is preferably 3 to 200 μm, and 4 to 100 μm.
m is more preferable, and 5 to 50 μm is even more preferable. If the film thickness is too thin, the film strength tends to decrease, and if the film thickness is too thick, the electrical resistance increases, which is not preferable as a diaphragm for a polymer electrolyte fuel cell. The film thickness can be controlled by appropriately selecting the concentration of the polyelectrolyte solution, the coating amount of the polyelectrolyte solution, the thickness of the porous support membrane, and the coating thickness on the porous support membrane. Further, additives such as antioxidants may be contained within a range not impairing the object of the present invention.

Next, the fuel cell of the present invention will be described.
The fuel cell of the present invention can be manufactured by bonding a catalyst and a conductive substance as a current collector to both surfaces of the polymer electrolyte membrane or the composite membrane. The catalyst is not particularly limited as long as it can activate the redox reaction with hydrogen or oxygen, and known catalysts can be used, but platinum fine particles are preferably used. Platinum fine particles are often used by being supported on particulate or fibrous carbon such as activated carbon or graphite. Known materials can be used for the conductive substance as the current collector,
Porous carbon nonwoven fabric or carbon paper
It is preferable for efficiently transporting the raw material gas to the catalyst.

The method of joining platinum fine particles or carbon carrying platinum fine particles to a porous carbon nonwoven fabric or carbon paper, and the method of joining it to a polymer electrolyte film are described in, for example, the Journal of
Electrochemical Society: Electrochemical Science a
Known methods such as the method described in nd Technology, Vol. 135 (9), 2209 (1988) can be used.

[0037]

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

Synthesis Example 1 (1,4-dimethoxy-2-
(Production of 6-bromohexyl) benzene) 1,4-dimethoxybenzene 13.
8 g (100 mmol) and 25 ml of tetrahydrofuran were introduced under an argon stream. Cooled to 0 ° C. and n-butyllithium 1.6M hexane solution (manufactured by Aldrich) 62.
5 ml (n-butyllithium: 100 mmol) was added dropwise over 15 minutes and the mixture was further stirred for 1 hour, and then 30.8 g (126 mmol) of 1,6-dibromohexane and 10 ml of THF.
After the mixture was added dropwise, the mixture was stirred at room temperature for 1.5 hours. Then, the reaction mass was poured into 50 ml of water and the tetrahydrofuran was distilled off under reduced pressure, followed by extraction with 50 ml of diethyl ether three times. After washing the organic layer with 100 ml of saturated saline,
Sodium sulfate was added to remove water, and the solvent was distilled off to obtain 37.7 g of a crude product. Silica gel column chromatography (developing solvent hexane: toluene = 1)
At 0: 1), 13.7 g (45.5 mmol) of 1,4-dimethoxy-2- (6-bromohexyl) benzene was obtained.
Yield 46%. Hereinafter, this compound is abbreviated as P1.

¹ H-NMR (300 MHz, CDCl ₃ ) 1.2 to 2.0 ppm (8 H, 4 kinds of methylene), 2.6 ppm (2
H, methylene at benzyl position), 3.4 ppm (2H, bromomethyl), 3.76, 3.77 ppm (3H, methyl for each), 6.6 to 6.9p
pm (3H, aromatic)

Synthesis Example 2 (Grignard Coupling of P1 and 4-Bromodiphenylether) 73 mg of magnesium metal (3.1 mg) in a flask at room temperature.
mmol) and 12.8 g of diethyl ether were introduced under an argon stream. 903 mg (3.0 mmol) of P1 was diluted with 2.0 ml of diethyl ether, added dropwise at 0 ° C., stirred at room temperature for 1.5 hours, and then heated under reflux for 1.5 hours. After allowing to cool to room temperature, under an argon stream, 623 mg (2.5 mmol) of 4-bromodiphenyl ether and dichloro [1,3-
Bis (diphenylphosphino) propane] nickel (I
I) A mixture of 10 mg (0.018 mmol) and 14.8 g of diethyl ether was added dropwise at 0 ° C. 0.5 at room temperature
After stirring for 1 hour, the mixture was heated under reflux for 8 hours, poured into 2N dilute hydrochloric acid and extracted with diethyl ether. The diethyl ether solution thus taken out was treated with sodium sulfate to remove water and the solvent was distilled off to obtain 1.1 g of a crude product. Silica gel column chromatography (Developing solvent is hexane: toluene = 1)
Purification at 0: 0 to 3: 1) gave 0.37 g (0.95 mmol) of the following coupling product. Yield 32%. Hereinafter, this compound is abbreviated as P2.

¹ H-NMR (300 MHz, CDCl ₃ ) 1.3 to 1.7 ppm (8 H, 4 kinds of methylene), 2.5 to 2.6 ppm
(4H, methylene at benzyl position), 3.76, 3.77ppm (each 3H, methyl), 6.7 to 6.8ppm (3H, hydroquinone moiety), 6.9 to 7.4ppm (9H, phenoxyphenyl moiety)

Synthesis Example 3 (Demethylation of P2) 29 ml of 1.0 M boron tribromide dichloromethane solution (manufactured by Wako Pure Chemical Industries, Ltd.) (boron tribromide: 29 mmol) was cooled to −78 ° C. under an argon atmosphere, P2 3.72 g
A dichloromethane solution prepared by dissolving (9.53 mmol) in 36 ml of dichloromethane was added dropwise while stirring. The mixture was stirred for 8 hours while warming to room temperature. The reaction mixture was opened in ice water and extracted with 200 ml of chloroform three times. The chloroform solution was washed with water, treated with sodium sulfate to remove water, and the solvent was distilled off to obtain 4.0 g of a crude product. The obtained crude product was purified by silica gel column chromatography (developing solvent: toluene: ethyl acetate = 4: 1) to obtain 1.91 g (5.27 mmol) of the following demethylated product. Yield 55
%. This compound is abbreviated as P3.

¹ H-NMR (300 MHz, CDCl ₃ ) 1.3 to 1.7 ppm (8 H, methylene), 2.5 to 2.6 ppm (4 H,
Methylene at benzyl position), 4.32, 4.36 ppm (each 1H, hydroxyl group), 6.5 to 6.7ppm (3H, hydroquinone moiety), 6.9
~ 7.4ppm (9H, phenoxyphenyl part)

Synthesis Example 4 (Production of sodium 6- (2,5-dimethoxyphenyl) hexanesulfonate) 12.1 g (40.0%) of P1 at room temperature under an argon stream.
mmol) was dissolved in 130 ml of ethanol, a mixture of 7.56 g (60.0 mmol) of sodium sulfite and 130 ml of water was added, and the mixture was heated under reflux for 12 hours. Then, the solvent was distilled off and the residue was washed with 100 ml of hexane three times, and then the aqueous solution was concentrated to dryness. 500 ml of methanol was added to the crude product to suspend it, and the insoluble matter was removed by filtration. Then, the filtered mother liquor was concentrated to dryness, and 12.3 g (38.0 mmo) of sodium 6- (2,5-dimethoxyphenyl) hexanesulfonate.
l) got. Yield 95%. This compound is abbreviated as P4.

¹ H-NMR (300 MHz, D ₂ O) 1.3 to 1.9 ppm (8 H, 4 kinds of methylene), 2.66, 2.96 ppm
(Each 2H, methylene at benzyl position), 3.87, 3.88ppm
(Each 3H, methyl), 6.9-7.1ppm (3H, aromatic)

Synthesis Example 5 (Demethylation of P4) 200 ml of a 1.0 M boron tribromide dichloromethane solution (manufactured by Wako Pure Chemical Industries, Ltd.) (boron tribromide: 200 mmol) was cooled to −78 ° C. under an argon atmosphere, P3 10.8g
(33.3 mmol) was added and stirred. After warming to room temperature over 5.5 hours, the mixture was stirred at room temperature for 24 hours, and the reaction mixture was poured into ice water. After distilling dichloromethane off under reduced pressure, ethanol was added and the precipitated inorganic salt was filtered off. Ethanol was distilled off from the filtrate under reduced pressure, and 5% aqueous sodium hydrogen carbonate solution was added to adjust the pH to 4. After distilling off the solvent, the residue was vacuum dried to obtain 10.6 g of a crude product. Purified by reverse-phase silica gel column chromatography, sodium 6- (2,5-dihydroxyphenyl) hexanesulfonate 9.8 g (3
3.1 mmol) was obtained. Yield 99%. This compound is abbreviated as P5.

MS (measurement method: ESI method (-)): 295
(Na ^{salt), 273 1 H-NMR (} 300MHz, D 2 O) 1.2~1.9ppm (8H, 4 or methylene), 2.47,2.83ppm
(Each 2H, methylene at benzyl position), 6.5 to 6.8 ppm (3
H, aromatic)

Example 1 P3 (0.71 g) and 4,4'-difluorodiphenylsulfone (0.50 g) were coexistent with potassium carbonate (0.31 g) in the presence of N, N-dimethylacetamide (5 ml) as a solvent.
Polycondensation was carried out at a temperature of 0 to 150 ° C. Subsequently, polyether sulfone having hydroxyl groups at both ends (manufactured by Sumitomo Chemical: PES4003
P, number average molecular weight: 39000)
Coupling was performed at ° C. The obtained block copolymer of the above formula was sulfonated with concentrated sulfuric acid to synthesize a block copolymer in which a sulfonic acid group was introduced into a side chain aromatic ring and / or hydroquinone unit. Table 1 shows the measurement results of the proton conductivity and the like of the film cast from dimethylacetamide.

Example 2 P04 (0.604 g) and 4,4'-difluorodiphenylsulfone (0.50 g) were coexisted with potassium carbonate (0.31 g) in the presence of N, N-dimethylacetamide (5 ml) as a solvent.
Polycondensation was carried out at a temperature of 30 to 150 ° C. to synthesize a copolymer having an alkylsulfonic acid group introduced into its side chain. The copolymer is shown below in the form of free acid.

Example 3 According to the method described in JP 2001-250567 A, 11.2 g of 2-benzylphenol and copper (I) bromide were used.
Using 0.28 g and 0.28 g of 2-phenylimidazole, an oxidative polymerization product was obtained by oxidative polymerization in a toluene-methanol mixed solvent at room temperature for 20 hours. 4.5 g of the obtained oxidative polymer and 10.5 g of PES (PES-5003P manufactured by Sumitomo Chemical Co., Ltd.) having hydroxyl groups at both ends were combined with 4,4′-difluorobiphenyl in the presence of potassium carbonate in a dimethylacetamide-toluene mixed solvent. Block polymerization was performed using 0.87 g as a linking member to obtain a block copolymer represented by the following formula. The obtained block copolymer was sulfonated with concentrated sulfuric acid to synthesize a block copolymer in which a sulfonic acid group was introduced into the benzene ring of the main chain and / or side chain of the block derived from 2-benzylphenol. Table 1 shows the measurement results of the proton conductivity and the like of the film cast from dimethylacetamide.

Comparative Example 1 Preparation of sulfonated polyether ether sulfone 4,4'-dihydroxydiphenyl sulfone, 4,4 '
-Dihydroxybiphenyl and 4,4'-dichlorodiphenyl sulfone at a molar ratio of 7: 3: 10 in the presence of potassium carbonate and diphenyl sulfone as a solvent to 200
Polycondensation occurred at a temperature of ~ 290 ° C. The obtained polymer was sulfonated with concentrated sulfuric acid to synthesize a random copolymer having a sulfonic acid group introduced into a biphenyl unit. Table 1 shows the measurement results of the proton conductivity and the ion exchange capacity of the film cast from dimethylacetamide.

Comparative Example 2 Production of Sulfonated Polyetheretherketone In a flask, 25 g of commercially available polyetheretherketone was used.
And 125 ml of concentrated sulfuric acid were charged, and at room temperature under a nitrogen stream, 4
The polymer was sulfonated by stirring for 8 hours. The sulfonated polyetheretherketone was deposited by dropping the reaction solution into 3 liters of deionized water, and collected by filtration. The deposited precipitate was washed with deionized water using a mixer and recovered with a suction filter until the washing liquid became neutral, and then dried under reduced pressure to obtain a polymer. The obtained polymer was redissolved in dimethylacetamide and the insoluble matter was filtered off, followed by casting to form a film having a thickness of 30 μm.
A film of Table 1 shows the measurement results of the ion exchange capacity and the proton conductivity of this product.

[0053]

[Table 1]

EFFECTS OF THE INVENTION According to the present invention, it is possible to provide an aromatic polymer having excellent proton conductivity and suitable for a polymer electrolyte for fuel cells.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yasaburo Daisaburo             6 Kitahara, Tsukuba, Ibaraki Sumitomo Chemical Co., Ltd.             In the company (72) Inventor Jun Terahara             6 Kitahara, Tsukuba, Ibaraki Sumitomo Chemical Co., Ltd.             In the company F-term (reference) 4J005 AA23 AA24 AA26 BA00                 5G301 CA01 CA30 CD01                 5H026 AA06 BB10 CX05 EE17

Claims (7)

[Claims] 1. A general formula (1) (In the formula, m represents an integer of 1 to 3, n represents an integer of 1 to 6, M represents a hydrogen atom, an alkali metal or ammonium. R represents H, SO ₃ H, F, a lower alkyl group or a lower alkyl group. Represents an alkoxy group, A is a direct bond,
In the divalent group of (5) or (6), B represents a direct bond or a group of the following formula (7) or (8). ) (In the formula, R ¹ and R ^{2 each} independently represent H, a lower alkyl group or a lower fluoroalkyl group. # Represents a bond to the benzene ring of the formula (1). L represents a direct bond, O Or S, and m has the same meaning as described above, m ¹ , m
² represents an integer, and the sum thereof is an integer of 1 to 3. * Is -SO ^- it represents that it is bound binds to ₃ M ^+. The benzene ring may be substituted. )) A polymer having a repeating structure represented by 2. The formula (2) The polymer according to claim 1, which has a repeating structure represented by the formula (Z represents SO ₂ and / or CO). 3. Formula (2 ′) (In the formula, x and y represent the number of each repeating structure, and x
And y are 10 to 100,000, and x is 0 to 100 times y. The arrangement of the repeating structure may be random, alternating, or block. Z, A, R, B, M, m, n
Represents the same meaning as described above. ) The polymer according to claim 1, which is represented by the formula (1). 4. Formula (3) (In the formula, X'represents a hydrogen atom, a chloro group, a bromo group, an iodo group, or A-OH, and m, n, M, R, B, and A have the same meanings as described above.) 4. The method for producing a polymer according to claim 1, wherein the group compound is used as a monomer component and is homopolymerized or is copolymerized with the dihalogeno aromatic compound. 5. A corresponding polymer is obtained by homopolymerizing an aromatic compound having m corresponding to 0 in the above formula (3) as a monomer component or copolymerizing the aromatic compound with a dihalogeno aromatic compound. 4. The method for producing a polymer according to claim 1, wherein the polymer is obtained and then the polymer is sulfonated. 6. A polymer electrolyte membrane using the polymer according to claim 1. 7. A fuel cell using the polymer electrolyte membrane according to claim 6.