JP2006179260A - Membrane-electrode structure for polymer electrolyte fuel cell and polymer electrolyte fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a membrane-electrode structure for a polymer electrolyte fuel cell having high adhesion between a solid polymer electrolyte membrane and an electrode, and to provide the polymer electrolyte fuel cell. <P>SOLUTION: The membrane-electrode structure for the polymer electrolyte fuel cell is formed by interposing a solid polymer electrolyte membrane between a pair of electrodes containing a catalyst. The solid polymer electrolyte membrane comprises a sulfonated polyarylene system copolymer equipped with a first repeating unit represented by formula (1) and a second repeating unit represented by formula (2). The polymer electrolyte fuel cell is equipped with the membrane-electrode assembly for the polymer electrolyte fuel cell. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a membrane-electrode structure for a polymer electrolyte fuel cell and a polymer electrolyte fuel cell comprising the membrane-electrode structure.

  While petroleum resources are depleted, environmental problems such as global warming due to the consumption of fossil fuels have become serious, and fuel cells have been widely developed as a clean power source for motors without carbon dioxide generation. At the same time, some have begun to be put into practical use. When the fuel cell is mounted on an automobile or the like, a solid polymer fuel cell using a solid polymer electrolyte membrane is preferably used because a high voltage and a large current are easily obtained.

  As an electrode structure used in the polymer electrolyte fuel cell, a pair of electrode catalysts formed by a catalyst such as platinum being supported on a catalyst carrier such as carbon black and integrated with an ion conductive polymer binder There is known a structure in which a solid polymer electrolyte membrane capable of ion conduction is sandwiched between both electrode catalyst layers, and a diffusion layer is laminated on each electrode catalyst layer. The electrode structure further forms a polymer electrolyte fuel cell by laminating a separator also serving as a gas passage on each electrode catalyst layer.

  In the polymer electrolyte fuel cell, a reducing gas such as hydrogen or methanol is introduced through the diffusion layer using one electrode catalyst layer as a fuel electrode, and the diffusion layer is formed using the other electrode catalyst layer as an oxygen electrode. An oxidizing gas such as air or oxygen is introduced. In this way, on the fuel electrode side, protons and electrons are generated from the reducing gas by the action of the catalyst contained in the electrode catalyst layer, and the protons pass through the solid polymer electrolyte membrane and the oxygen electrode. It moves to the electrode catalyst layer on the side. The protons react with the oxidizing gas and electrons introduced into the oxygen electrode by the action of the catalyst contained in the electrode catalyst layer in the electrode catalyst layer on the oxygen electrode side to generate water. Therefore, by connecting the fuel electrode and the oxygen electrode with a conducting wire, a circuit for sending electrons generated at the fuel electrode to the oxygen electrode is formed, and a current can be taken out.

  In the electrode structure, a perfluoropolymer represented by a polymer belonging to a so-called cation exchange resin as the solid polymer electrolyte membrane, for example, a sulfonated product of vinyl polymer such as polystyrene sulfonic acid, Nafion (trade name, manufactured by DuPont). An organic polymer such as a polymer in which a sulfonic acid group or a phosphoric acid group is introduced into a heat-resistant polymer such as an alkyl sulfonic acid polymer, a perfluoroalkyl carboxylic acid polymer, polybenzimidazole, or polyether ether ketone is preferably used.

  These organic polymers are usually used in the form of a film, but a conductive film can be bonded on the electrode by utilizing the solubility in a solvent or thermoplasticity. However, many of these organic polymers are not yet sufficiently proton-conductive, have low durability, have low proton conductivity at high temperatures (100 ° C. or higher), become brittle due to sulfonation, There are problems such as a decrease in mechanical strength, a large dependence on humidity conditions, and a lack of satisfactory adhesion to the electrodes. Furthermore, these organic polymers have a problem that due to the water-containing polymer structure, the strength decreases due to excessive swelling during operation of the fuel cell, or the shape collapses.

  On the other hand, solid polymer electrolytes made of sulfonated rigid polyphenylene are known (see, for example, Patent Document 1). The rigid polyphenylene is mainly composed of a polymer obtained by polymerizing an aromatic compound composed of a phenylene chain, and this is reacted with a sulfonating agent to introduce a sulfonic acid group, thereby increasing the introduction amount of the sulfonic acid group. Improves proton conductivity.

However, since the rigid polyphenylene has a high thermal deformation temperature, there is a problem in that sufficient adhesiveness may not be obtained with the electrode when it is bonded to the electrode by hot pressing.
US Pat. No. 5,403,675 Japanese Patent Laid-Open No. 7-220741 Polymer Preprints, Japan, Vol.42, No.3, p.730 (1993) Polymer Preprints, Japan, Vol.43, No.3, p.736 (1994) Polymer Preprints, Japan, Vol.42, No.7, p.2490-2492 (1993)

  The present invention eliminates such inconvenience and can obtain excellent adhesion between the solid polymer electrolyte membrane and the electrode when the solid polymer electrolyte membrane and the electrode are joined by hot pressing. An object of the present invention is to provide a membrane-electrode structure for a polymer electrolyte fuel cell.

  Another object of the present invention is to provide a polymer electrolyte fuel cell having excellent durability and having excellent adhesion between the polymer electrolyte membrane and the electrode.

  In order to achieve this object, the membrane-electrode structure for a polymer electrolyte fuel cell of the present invention comprises a membrane for a polymer electrolyte fuel cell in which a polymer electrolyte membrane is sandwiched between a pair of electrodes containing a catalyst. -In an electrode structure, the said solid polymer electrolyte membrane is a polyarylene provided with the 1st repeating unit represented by following General formula (1), and the 2nd repeating unit represented by following General formula (2). It consists of a sulfonated product of a copolymer.

  The sulfonated product of the polyarylene copolymer contains the second repeating unit represented by the general formula (2), so that the side chain has an alkyl group having 2 or more carbon atoms or a halogenated group having 2 or more carbon atoms. An alkyl group is introduced. Therefore, the sulfonated product of the polyarylene copolymer has a lower thermal deformation temperature than when the side chain is not provided with an alkyl group having 2 or more carbon atoms or a halogenated alkyl group having 2 or more carbon atoms.

  As a result, when the solid polymer electrolyte membrane made of the sulfonated polyarylene copolymer and the electrode are joined by hot pressing, excellent adhesion between the solid polymer electrolyte membrane and the electrode is achieved. Sex can be obtained.

In the membrane-electrode structure for a polymer electrolyte fuel cell of the present invention, A in the second repeating unit represented by the general formula (2) is -CR ¹ R ^2- (R ¹ and R ² are May be the same as or different from each other, but at least one of them is an alkyl group having 2 or more carbon atoms or a halogenated alkyl group having 2 or more carbon atoms, and when R ¹ and R ² are different from each other, either one is a hydrogen atom , A fluorine atom, a methyl group, or a halogenated methyl group, and R ¹ and R ² may be combined to form a ring), or —C ( _{CH 3) 2 -, - C} (CF 3) 2 -, - CO -, - COO -, - CONH -, - (CF 2) p - (p is an integer of 1 to 10), - SO ₂ - ,

A second group or a direct bond which is one group selected from the group consisting of: a sulfonated product of the polyarylene copolymer, wherein the first group and the second group as A in the molecule or It is preferable to provide both direct bonds.

  In this case, by adjusting the content of A as the first group and A as the second group or a direct bond, the sulfone of the polyarylene copolymer in which A is only the first group. And a sulfone of a polyarylene copolymer having a heat distortion temperature intermediate between the heat distortion temperatures inherent to each of the sulfonated product of the polyarylene copolymer in which A is the second group or A. The compound can be obtained.

  Moreover, since the polymer electrolyte fuel cell of the present invention uses a membrane-electrode structure provided with the solid polymer electrolyte membrane, excellent adhesion between the solid polymer electrolyte membrane and the electrode is obtained. And excellent durability can be obtained.

  Next, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an explanatory cross-sectional view showing the configuration of the membrane-electrode structure of the present embodiment.

  As shown in FIG. 1, the membrane-electrode structure of the present embodiment includes a solid polymer electrolyte membrane 1, a pair of electrode catalyst layers 2 and 2 that sandwich the solid polymer electrolyte membrane 1, and each electrode catalyst layer. It consists of gas diffusion layers 3 and 3 laminated on 2 and 2.

  The solid polymer electrolyte membrane 1 is a polyarylene-based co-polymer comprising a first repeating unit represented by the following general formula (1) and a second repeating unit represented by the following general formula (2). It consists of a polymer sulfonated product. Here, the first repeating unit is a sulfonic acid group introduction unit, and the second repeating unit is a hydrophobic unit.

In the general formula (1), the divalent electron-withdrawing group represented by Y, for _{example, -CO -, - SO 2 -} , - SO -, - CONH -, - COO -, - (CF 2) p - (p is an integer of 1 to _{10), - C (CF 3)} 2 - and the like groups may be mentioned of. The electron-withdrawing group refers to a group having a value of 0.06 or more when the Hammett substituent constant is m-position of the phenyl group and 0.01 or more when p-position.

In the general formula (1), examples of the divalent electron-donating group represented by Z include — (CH ₂ ) —, —C (CH ₃ ) ₂ —, —O—, —S—, — CH = CH-, -C≡C-,

And the like.

In the general formula (1), examples of the aromatic group represented by Ar and having a —SO ₃ H group include a phenyl group, a naphthyl group, an anthracenyl group, and a phenanthyl group. The aromatic group is preferably a phenyl group or a naphthyl group among the above groups.

In the group represented by A in the general formula (2), examples of the alkyl group having 2 or more carbon atoms represented by R ¹ or R ² include an ethyl group, a propyl group, an iso-propyl group, a butyl group, an iso- Examples thereof include a butyl group, a tert-butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decyl group. The alkyl group may be halogenated.

In the general formula (2), examples of the alkyl group represented by R ^{3 to} R ¹⁸ include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group. It is preferably a group or an ethyl group. The alkyl group may be halogenated.

In the general formula (2), A is, the ^-CR 1 ^{R 2} - first structure represented by _{or,, -C (CH 3) 2} -, - C (CF 3) 2 -, - CO -, - COO -, - CONH -, - (CF 2) p - (p is an integer of 1 to 10), - _SO 2 -,

One group selected from the group consisting of: a second structure which is a direct bond, and the sulfonated product of the polyarylene-based copolymer has both of the first and second structures as A in the molecule. It is preferable to provide a structure. The sulfonated product of the polyarylene-based copolymer can easily adjust the heat distortion temperature by providing both the first structure and the second structure as A in the molecule.

  The sulfonated product of the polyarylene copolymer contains 99.5 to 0 mol%, preferably 90 to 0.001 mol% of the first repeating unit represented by the general formula (1), The repeating unit represented by the general formula (2) is contained in an amount of 0.5 to 100 mol%, preferably 10 to 99.999 mol%.

  The sulfonated product of the polyarylene copolymer is represented by, for example, a monomer that can be a repeating unit having a sulfonic acid ester group instead of a sulfonic acid group in the general formula (1), and the general formula (2). Monomers that can be a repeating unit are copolymerized to produce a polyarylene copolymer having a sulfonic acid ester group, and the polyarylene copolymer is hydrolyzed to convert the sulfonic acid ester group to a sulfonic acid group. Can be synthesized.

  The sulfonated product of the polyarylene copolymer includes, for example, a monomer that can be a repeating unit that does not have a sulfonic acid group in the general formula (1), and a monomer that can be a repeating unit represented by the general formula (2). And a polyarylene copolymer having no sulfonic acid group is synthesized in advance, and the copolymer is sulfonated.

  Examples of the monomer that can be a repeating unit having a sulfonic acid ester group in place of the sulfonic acid group in the general formula (1) include an aromatic sulfonic acid ester derivative represented by the following general formula (3). it can.

In the general formula (3), Y, Z, j, k, and l are as defined in the general formula (1), and X ′ is a halogen atom (chlorine, bromine, iodine) excluding fluorine or —OSO ₂ G (here And G represents an alkyl group, a fluorine-substituted alkyl group or an aryl group).

In the general formula (3), R ^a represents a hydrocarbon group having 1 to 20 carbon atoms, preferably 4 to 20 carbon atoms, specifically, a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, tert-butyl group, iso-butyl group, n-butyl group, sec-butyl group, neopentyl group, cyclopentyl group, hexyl group, cyclohexyl group, cyclopentylmethyl group, cyclohexylmethyl group, adamantyl group, adamantanemethyl group, 2- Ethylhexyl group, bicyclo [2.2.1] heptyl group, bicyclo [2.2.1] heptylmethyl group, tetrahydrofurfuryl group, 2-methylbutyl group, 3,3-dimethyl-2,4-dioxolanemethyl Group, cyclohexylmethyl group, linear hydrocarbon group such as adamantylmethyl group, branched hydrocarbon group, alicyclic hydrocarbon group, Examples thereof include a hydrocarbon group having a 5-membered heterocyclic ring. Among these, n-butyl group, neopentyl group, tetrahydrofurfuryl group, cyclopentyl group, cyclohexyl group, cyclohexylmethyl group, adamantylmethyl group, and bicyclo [2.2.1] heptylmethyl group are preferable, and neopentyl group is particularly preferable. preferable.

Ar represents an aromatic group having a substituent represented by —SO ₃ R ^b , and examples of the aromatic group include a phenyl group, a naphthyl group, an anthracenyl group, and a phenanthyl group. Of these groups, a phenyl group or a naphthyl group is preferable.

In the substituent —SO ₃ R ^b , one or more substituents are substituted on the aromatic group, and when two or more substituents —SO ₃ R ^b are substituted, these substituents are It may be the same or different.

Here, R ^b represents a hydrocarbon group having 1 to 20 carbon atoms, preferably 4 to 20 carbon atoms, and specifically includes the same hydrocarbon group having 1 to 20 hydrocarbon atoms as the ^Ra described above. Can do. Among these, n-butyl group, neopentyl group, tetrahydrofurfuryl group, cyclopentyl group, cyclohexyl group, cyclohexylmethyl group, adamantylmethyl group, and bicyclo [2.2.1] heptylmethyl group are preferable, and neopentyl group is particularly preferable. preferable.

  Specific examples of the aromatic sulfonic acid ester derivative represented by the general formula (3) include the following compounds.

In addition, the aromatic sulfonic acid ester derivative represented by the general formula (3) includes a compound in which a chlorine atom is replaced with a bromine atom in each compound of the specific examples, a compound in which —CO— is replaced with —SO ₂ —, chlorine atom is replaced by a bromine atom, and, -CO- is -SO ₂ - also it includes compounds such as replacing a.

The R ^b group in the general formula (3) is derived from a primary alcohol, and the β carbon is tertiary or quaternary carbon, which is excellent in stability during the polymerization process, and sulfonic acid is generated by deesterification. It is preferable in that it does not cause polymerization inhibition or cross-linking due to the above, and it is preferable that these ester groups are derived from primary alcohols and the β-position is quaternary carbon.

  Examples of the monomer that can be a repeating unit not having a sulfonic acid group in the general formula (1) include the following compounds.

In the general formula (1), the monomer that can be a repeating unit having no sulfonic acid group includes a compound in which a chlorine atom is replaced with a bromine atom in each compound, a compound in which —CO— is replaced with —SO ₂ —, a chlorine atom There replaced by a bromine atom, and, -CO- is -SO ₂ - also includes compounds such as replacing a.

  Examples of the monomer that can be a repeating unit represented by the general formula (2) include a compound represented by the following general formula (4). By containing a repeating unit derived from the compound represented by the general formula (4), a hydrophobic unit is imparted to the polyarylene copolymer, and an alkyl group having 2 or more carbon atoms or carbon number in the side chain. Two or more halogenated alkyl groups can be introduced.

In the general formula (4), A, B, D, R ^{3 to} R ¹⁸ , m, and n are as defined in the general formula (2), and X is a halogen atom excluding fluorine (chlorine, bromine, iodine). , -OSO ₂ CH _3, showing the atom or group selected from -OSO ₂ CF _3.

  The compound represented by the general formula (4) can be synthesized, for example, by the following reaction. First, let the compound (henceforth bisphenols) represented by following General formula (5) be an alkali metal salt of corresponding bisphenols.

In the general formula ^{(5), A, B,} R 3 ~R 18 has the same meaning as in formula (2).

  In order to obtain the alkali metal salt, the bisphenol is a lithium salt in a polar solvent having a high dielectric constant, such as N-methyl-2-pyrrolidone, N, N-dimethylacetamide, sulfolane, diphenylsulfone, and dimethylsulfoxide. Add alkali metals such as sodium and potassium, alkali metal hydrides, alkali metal hydroxides, alkali metal carbonates and the like. The alkali metal is reacted in excess with respect to the hydroxyl group of the bisphenol, and is usually used in an amount of 1.1 to 2 times equivalent, preferably 1.2 to 1.5 times equivalent. At this time, it is preferable to promote the progress of the reaction by coexisting a solvent azeotropic with water such as benzene, toluene, xylene, chlorobenzene, and anisole.

  Examples of the bisphenols represented by the general formula (5) include the following compounds.

  Next, the alkali metal salt of the bisphenol represented by the general formula (5) is reacted with an aromatic dihalide compound substituted with a halogen atom such as chlorine. Examples of the aromatic dihalide compound include 4,4′-difluorobenzophenone, 4,4′-dichlorobenzophenone, 4,4′-chlorofluorobenzophenone, bis (4-chlorophenyl) sulfone, and bis (4-fluorophenyl). Sulfone, 4-fluorophenyl-4′-chlorophenylsulfone, bis (3-nitro-4-chlorophenyl) sulfone, 2,6-dichlorobenzonitrile, 2,6-difluorobenzonitrile, 2,5-dichlorobenzonitrile, 2 , 5-difluorobenzonitrile, 2,4-dichlorobenzonitrile, 2,4-difluorobenzonitrile, 2,6-dinitrobenzonitrile, 2,5-dinitrobenzonitrile, 2,4-dinitrobenzonitrile, 1,2 -Bis (4-chlorobenzoyl) benzene 1,3-bis (4-chlorobenzoyl) benzene, 1,4-bis (4-chlorobenzoyl) benzene, 1,2-bis (3-chlorobenzoyl) benzene, 1,3-bis (3-chlorobenzoyl) Benzene, 1,4-bis (3-chlorobenzoyl) benzene, 1,2-bis (2-chlorobenzoyl) benzene, 1,3-bis (2-chlorobenzoyl) benzene, 1,4-bis (2-chloro) Benzoyl) benzene, 1,3-bis (4-chlorobenzoyl) -2,4,5,6-tetrafluorobenzene, 1,4-bis (4-chlorobenzoyl) -2,3,5,6-tetrafluoro Benzene, 1,2-bis {(4-chlorophenyl} sulfonyl) benzene, 1,3-bis {(4-chlorophenyl} sulfonyl) benzene, 1,4-bis {(4-chloro Phenyl} sulfonyl) benzene, and the like.

  The aromatic dihalide compound is used in an amount in the range of 1.0001 to 1 mol, preferably 1.001 to 2 mol, relative to 1 mol of the bisphenol. In addition, the reaction product is reacted again with an excess of aromatic dichloride, for example, 4,4′-dichlorobenzophenone, 2,6-dichlorobenzonitrile, etc., after the reaction is finished so that both ends of the reaction product are chlorine atoms. May be.

  These reactions are performed at a reaction temperature in the range of 60 to 300 ° C, preferably in the range of 80 to 250 ° C, and in a reaction time of 15 minutes to 100 hours, preferably in the range of 1 to 24 hours.

  The obtained oligomer or polymer can be purified by a general polymer purification method, for example, a dissolution-precipitation operation. The molecular weight can be adjusted by the reaction molar ratio of the excess aromatic dihalide compound and the bisphenol.

  Examples of the bisphenols obtained as described above include the following compounds.

  In the present embodiment, a sulfonated product of a polyarylene copolymer (hereinafter sometimes simply referred to as “sulfonated polyarylene”) includes the aromatic sulfonate ester derivative and the bisphenol in the presence of a catalyst. After the reaction, the sulfonic acid ester group is hydrolyzed and converted into a sulfonic acid group.

  The catalyst used in the reaction is a catalyst system containing a transition metal compound, and as such a catalyst system, a compound that becomes a transition metal salt and a ligand (hereinafter referred to as “ligand component”), or A transition metal complex coordinated with a ligand (including a copper salt) and a reducing agent are essential components, and a “salt” may be added to increase the polymerization rate.

  Here, as the transition metal salt, for example, nickel compounds such as nickel chloride, nickel bromide, nickel iodide, nickel acetylacetonate, palladium compounds such as palladium chloride, palladium bromide, palladium iodide, iron chloride, Examples thereof include iron compounds such as iron bromide and iron iodide, and cobalt compounds such as cobalt chloride, cobalt bromide and cobalt iodide. Of these, nickel chloride, nickel bromide and the like are particularly preferable.

  Examples of the ligand component include triphenylphosphine, 2,2'-bipyridine, 1,5-cyclooctadiene, 1,3-bis (diphenylphosphino) propane, and the like. Of these, triphenylphosphine or 2,2'-bipyridine is preferred. The compound which is the said ligand component may be used individually by 1 type, or may use 2 or more types together.

  Further, examples of the transition metal complex coordinated with the ligand include nickel chloride bis (triphenylphosphine), nickel bromide bis (triphenylphosphine), nickel iodide bis (triphenylphosphine), nickel nitrate. Bis (triphenylphosphine), nickel chloride (2,2′-bipyridine), nickel nitrate (2,2′-bipyridine), bis (1,5-cyclooctadiene) nickel, tetrakis (triphenylphosphine) nickel, tetrakis (Triphenylphosphite) nickel, tetrakis (triphenylphosphine) palladium and the like can be mentioned. Of these, nickel chloride bis (triphenylphosphine) or nickel chloride (2,2'-bipyridine) is preferred.

  Examples of the reducing agent that can be used in the catalyst system include iron, zinc, manganese, aluminum, magnesium, sodium, calcium, and the like. Of these, zinc, magnesium and manganese are preferred. These reducing agents can be used after being more activated by contacting with an acid such as an organic acid.

  The “salt” used in the catalyst system includes sodium compounds such as sodium fluoride, sodium chloride, sodium bromide, sodium iodide, sodium sulfate, potassium fluoride, potassium chloride, potassium bromide, potassium iodide. And potassium compounds such as potassium sulfate, and ammonium compounds such as tetraethylammonium fluoride, tetraethylammonium chloride, tetraethylammonium bromide, tetraethylammonium iodide, and tetraethylammonium sulfate. Of these, sodium bromide, sodium iodide, potassium bromide, tetraethylammonium bromide, and tetraethylammonium iodide are preferred.

  The proportion of each component used is usually from 0.0001 to 10 mol based on 1 mol of the total amount of the monomers (the total of the aromatic sulfonic acid ester derivative and the bisphenols) of the transition metal salt or transition metal complex. , Preferably 0.01 to 0.5 mol. If the amount is less than 0.0001 mol, the polymerization reaction may not proceed sufficiently. On the other hand, if the amount exceeds 10 mol, the molecular weight of the resulting polyarylene copolymer having a sulfonate group may be lowered.

  In the catalyst system, when the transition metal salt and the ligand component are used, the ratio of the ligand component used is usually 0.1 to 100 mol, preferably 1 to 1 mol of the transition metal salt. -10 mol. When the amount is less than 0.1 mol, the catalytic activity may be insufficient. On the other hand, when the amount exceeds 100 mol, the molecular weight of the resulting polyarylene copolymer having a sulfonate group may be lowered.

  Moreover, the usage-amount of the said reducing agent is 0.1-100 mol normally with respect to 1 mol of total of the said monomer, Preferably it is 1-10 mol. If the amount is less than 0.1 mol, polymerization may not proceed sufficiently. If the amount exceeds 100 mol, purification of the resulting polyarylene copolymer having a sulfonate group may be difficult.

  Furthermore, when using "salt", the usage-ratio is 0.001-100 mol normally with respect to the total of 1 mol of the said monomer, Preferably it is 0.01-1 mol. If the amount is less than 0.001 mol, the effect of increasing the polymerization rate may be insufficient. If the amount exceeds 100 mol, purification of the polyarylene copolymer having a sulfonate group obtained may be difficult. is there.

  Examples of a polymerization solvent that can be used when the aromatic sulfonic acid ester derivative and the bisphenol are reacted include tetrahydrofuran, cyclohexane, dimethyl sulfoxide, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, γ-butyrolactone, N, N′-dimethylimidazolidinone and the like can be mentioned. Of these, tetrahydrofuran, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, and N, N'-dimethylimidazolidinone are preferred. These polymerization solvents are preferably used after sufficiently dried.

  The total concentration of the monomers in the polymerization solvent is usually 1 to 90% by weight, preferably 5 to 40% by weight. The polymerization temperature for the polymerization is usually 0 to 200 ° C, preferably 50 to 120 ° C. The polymerization time is usually 0.5 to 100 hours, preferably 1 to 40 hours.

  A polyarylene copolymer having a sulfonic acid ester group obtained by using the aromatic sulfonic acid ester derivative is obtained by hydrolyzing the sulfonic acid ester group and converting the sulfonic acid ester group into a sulfonic acid group. It can be.

As a method of hydrolysis, a method in which the polyarylene copolymer having a sulfonic acid ester group is added to an excess amount of water or alcohol containing a small amount of hydrochloric acid, and the mixture is stirred for 5 minutes or more. A method of reacting a polyarylene copolymer having a sulfonic acid ester group at a temperature of about 80 to 120 ° C. for about 5 to 10 hours, a sulfonic acid ester group in a polyarylene copolymer having a sulfonic acid ester group (- SO ₃ R ^a and _-SO 3 ^R b) solution, for example, N- methyl-2-pyrrolidone solution the polyarylene copolymer in such an 80 comprising 1-3 moles of lithium bromide with respect to 1 mole of Examples include a method of adding hydrochloric acid after reacting at a temperature of about 150 ° C. for about 3 to 10 hours.

  Further, in the present embodiment, the sulfonated polyarylene is obtained by copolymerizing a monomer that can be a repeating unit having no sulfonic acid group in the general formula (1) with the bisphenols. A polyarylene copolymer having no group (hereinafter, simply referred to as “non-sulfonated polyarylene”) may be synthesized in advance, and the non-sulfonated polyarylene may be sulfonated. In this case, after the non-sulfonated polyarylene is produced by a method according to the method for synthesizing the polyarylene copolymer having the sulfonate group, the sulfonate group is added to the non-sulfonated polyarylene using a sulfonating agent. The sulfonated polyarylene can be obtained by introducing.

  The method for introducing the sulfonic acid group is not particularly limited, and can be performed by a general method. For example, the non-sulfonated polyarylene is sulfonated under known conditions using a known sulfonating agent such as sulfuric anhydride, fuming sulfuric acid, chlorosulfonic acid, sulfuric acid, sodium bisulfite in the absence of solvent or in the presence of a solvent. The sulfonic acid group can be introduced by converting (see Non-Patent Documents 1 to 3).

  Examples of the solvent used in the sulfonation include hydrocarbon solvents such as n-hexane, ether solvents such as tetrahydrofuran and dioxane, aprotic polar solvents such as dimethylacetamide, dimethylformamide and dimethylsulfoxide, and tetrachloroethane. And halogenated hydrocarbon solvents such as dichloroethane, chloroform and methylene chloride. Although reaction temperature is not specifically limited, Usually, -50-200 degreeC, Preferably it is -10-100 degreeC. Moreover, reaction time is 0.5 to 1,000 hours normally, Preferably it is 1 to 200 hours.

  The amount of sulfonic acid group in the sulfonated polyarylene produced by the method as described above is usually 0.3 to 5 meq / g, preferably 0.5 to 3 meq / g, more preferably 0.8 to 2.8 meq. / G. If it is less than 0.3 meq / g, the proton conductivity is low and not practical, and if it exceeds 5 meq / g, the water resistance may be lowered. The amount of the sulfonic acid group can be adjusted, for example, by changing the type, use ratio, combination, and the like of the monomer.

  The molecular weight of the sulfonated polyarylene thus obtained is 10,000 to 1,000,000, preferably 20,000 to 800,000 in terms of polystyrene-equivalent weight average molecular weight by gel permeation chromatography (GPC). The sulfonated polyarylene can obtain excellent coating properties, strength properties, solubility, workability, and the like when the molecular weight is within the above range.

Structure of the sulfonated polyarylene, by an infrared absorption ^{spectrum, 1,030~1,045cm -1,} S = O absorption at 1,160~1,190cm ^-1, C of 1,130～1,250Cm ^-1 It can be confirmed by —O—C absorption, C = O absorption of 1,640 to 1,660 cm ⁻¹ , etc., and the composition ratio can be known by neutralization titration of sulfonic acid or elemental analysis. Moreover, the structure can be confirmed from the peak of aromatic protons at 6.8 to 8.0 ppm by nuclear magnetic resonance spectrum ( ¹ H-NMR).

  The solid polymer electrolyte membrane 1 is prepared using a polymer electrolyte made of the sulfonated polyarylene. Moreover, when preparing the solid polymer electrolyte membrane 1, in addition to the polymer electrolyte, an inorganic acid such as sulfuric acid or phosphoric acid, an organic acid containing a carboxylic acid, an appropriate amount of water, or the like may be used in combination. In addition, an antioxidant such as a phenolic hydroxyl group-containing compound, an amine compound, an organic phosphorus compound, or an organic sulfur compound may be included as long as proton conductivity is not impaired.

  The solid polymer electrolyte membrane 1 is manufactured by dissolving the sulfonated polyarylene in a solvent to form a solution, and then casting the film on a substrate to form the film into a film. can do.

  The substrate is not particularly limited as long as it is a substrate used in an ordinary solution casting method. For example, a substrate made of plastic or metal can be used, and preferably a thermoplastic such as a polyethylene terephthalate (PET) film. A substrate made of a resin can be used.

  Examples of the solvent for dissolving the sulfonated polyarylene include N-methyl-2-pyrrolidone, N, N-dimethylformamide, γ-butyrolactone, N, N-dimethylacetamide, dimethyl sulfoxide, dimethylurea, dimethylimidazolidinone. An aprotic polar solvent such as N-methyl-2-pyrrolidone (hereinafter sometimes referred to as “NMP”) is preferable from the viewpoint of solubility and solution viscosity. The aprotic polar solvents can be used singly or in combination of two or more.

  In addition, as the solvent for dissolving the sulfonated polyarylene, a mixture of the aprotic polar solvent and alcohol may be used. Examples of the alcohol include methanol, ethanol, propyl alcohol, iso-propyl alcohol, sec-butyl alcohol, tert-butyl alcohol, and the like. Methanol is particularly preferable because it has an effect of lowering the solution viscosity in a wide composition range. The said alcohol may be used individually by 1 type, or may use 2 or more types together.

  When a mixture of an aprotic polar solvent and an alcohol is used as the solvent, the aprotic polar solvent is 95 to 25% by weight, preferably 90 to 25% by weight, and the alcohol is 5 to 75% by weight, preferably It is used in the range of 10 to 75% by weight (total 100% by weight). When the amount of alcohol is within the above range, an excellent effect can be obtained in terms of lowering the solution viscosity.

  The polymer concentration of the solution in which the sulfonated polyarylene is dissolved is usually 5 to 40% by weight, preferably 7 to 25% by weight, although it depends on the molecular weight of the sulfonated polyarylene. If it is less than 5% by weight, it is difficult to form a thick film, and pinholes are easily generated. On the other hand, if it exceeds 40% by weight, the solution viscosity is so high that it is difficult to form a film, and surface smoothness may be lacking.

  The solution viscosity is usually in the range of 2,000 to 100,000 mPa · s, preferably 3,000 to 50,000 mPa · s, although it depends on the molecular weight of the sulfonated polyarylene and the polymer concentration. If it is less than 2,000 mPa · s, the retention of the solution during film formation is poor, and it may flow out of the substrate. On the other hand, if it exceeds 100,000 mPa · s, the viscosity is too high to be extruded from the die, and it may be difficult to form a film by the casting method.

  After film formation as described above, when the obtained undried film is immersed in water, the organic solvent in the undried film can be replaced with water, and the residual solvent amount of the obtained solid polymer electrolyte membrane 1 Can be reduced. In addition, you may pre-dry an undried film after film formation, before immersing an undried film in water. The preliminary drying is performed by holding the undried film at a temperature of usually 50 to 150 ° C. for 0.1 to 10 hours.

  When immersing the undried film in water, it may be a batch method in which the undried film is immersed in water one by one, and the laminated film in a state of being formed on a substrate film (for example, PET), Alternatively, a continuous system in which a film separated from the substrate is immersed in water and wound up may be used. In the case of the batch method, it is possible to suppress the formation of wrinkles on the surface of the processed film by taking a method such as fitting the processed film in a frame, which is convenient.

  When the undried film is immersed in water, it is preferable that the water has a contact ratio of 10 parts by weight or more, preferably 30 parts by weight or more with respect to 1 part by weight of the undried film. In order to minimize the residual solvent amount of the obtained solid polymer electrolyte membrane 1, it is preferable to maintain a contact ratio as large as possible. In addition, it is possible to change the amount of residual solvent in the resulting solid polymer electrolyte membrane 1 by changing the water used for immersion or overflowing it so that the organic solvent concentration in the water is always kept below a certain level. It is effective for. Homogenizing the concentration of the organic solvent in the water by stirring or the like is effective for reducing the in-plane distribution of the amount of the organic solvent remaining in the solid polymer electrolyte membrane 1.

  The water temperature when the undried film is immersed in water is preferably in the range of 5 to 80 ° C. The higher the water temperature, the faster the replacement rate of the organic solvent and water, but the greater the amount of water absorbed by the film, so that the surface state of the solid polymer electrolyte membrane 1 obtained after drying may be roughened. Usually, a temperature range of 10 to 60 ° C. is convenient in terms of the replacement speed and ease of handling. The immersion time is usually in the range of 10 minutes to 240 hours, preferably 30 minutes to 100 hours, although depending on the initial residual solvent amount, contact ratio, and treatment temperature.

  When the undried film is immersed in water and dried as described above, the solid polymer electrolyte membrane 1 with a reduced amount of residual solvent is obtained. The residual solvent amount of the solid polymer electrolyte membrane 1 thus obtained is obtained. Is usually 5% by weight or less. Further, depending on the immersion conditions, the amount of residual solvent in the obtained solid polymer electrolyte membrane 1 can be set to 1% by weight or less. To do this, for example, the contact ratio between the undried film and water is 50 parts by weight or more with respect to 1 part by weight of the undried film. It is suitable that the time is 10 minutes to 10 hours.

  After immersing the undried film in water as described above, the film is dried at 30-100 ° C, preferably 50-80 ° C, for 10-180 minutes, preferably 15-60 minutes, and then at 50-150 ° C. The solid polymer electrolyte membrane 1 can be obtained by vacuum drying under reduced pressure of 500 mmHg to 0.1 mmHg for 0.5 to 24 hours.

  The solid polymer electrolyte membrane 1 obtained by the method as described above has a dry film thickness of usually 10 to 100 μm, preferably 20 to 80 μm.

  In addition, the solid polymer electrolyte membrane 1 is produced by hydrolyzing the sulfonated polyarylene copolymer without being hydrolyzed, after being formed into a film by the method described above. You can also.

  The solid polymer electrolyte membrane 1 may contain an anti-aging agent, preferably a hindered phenol compound having a molecular weight of 500 or more. By containing the anti-aging agent, the durability of the solid polymer electrolyte membrane 1 can be increased. It can be improved further.

  Examples of hindered phenol compounds that can be used in the present embodiment include triethylene glycol bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate] (trade name: IRGANOX 245), 1,6-hexanediol bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] (trade name: IRGANOX 259), 2,4-bis- (n-octylthio) -6 (4-hydroxy-3,5-di-t-butylanilino) -3,5-triazine (trade name: IRGANOX 565), pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4- Hydroxyphenyl) propionate] (trade name: IRGANOX 1010), 2,2-thio-diethylenebis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate ] (Trade name: IRGANOX 1035), octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] (trade name: IRGANOX 1076), N, N-hexamethylene bis (3,5 -Di-t-butyl-4-hydroxy-hydrocinnamamide) (trade name: IRGANOX 1098 (trade name)), 1,3,5-trimethyl-2,4,6-tris (3,5-di-) t-butyl-4-hydroxybenzyl) benzene (trade name: IRGANOX 1330), tris- (3,5-di-t-butyl-4-hydroxybenzyl) -isocyanurate] (trade name: IRGANOX 3114), 3 , 9-bis [2- [3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionyloxy] -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [ 5.5] Undecane (Brand name: Su milizer GA-80).

  The hindered phenol compound having a molecular weight of 500 or more is preferably used in an amount of 0.01 to 10 parts by weight with respect to 100 parts by weight of the sulfonated polyarylene.

  Next, the electrode catalyst layer 2 comprises a catalyst and an ion conductive polymer electrolyte.

  The catalyst is preferably a supported catalyst in which platinum or a platinum alloy is supported on a carbon material having developed pores. As the carbon material having developed pores, carbon black, activated carbon, or the like can be preferably used. Examples of the carbon black include channel black, furnace black, thermal black, acetylene black and the like, and the activated carbon includes those obtained by carbonizing and activating various carbon atom-containing materials. Can be mentioned. Moreover, you may use what carbonitized these carbon materials.

  The catalyst may be one in which platinum is supported on a carbon support, but by using a platinum alloy, stability and activity as an electrode catalyst can be further imparted. Examples of the platinum alloy include platinum group metals other than platinum such as ruthenium, rhodium, palladium, osmium, iridium, cobalt, iron, titanium, gold, silver, chromium, manganese, molybdenum, tungsten, aluminum, silicon, rhenium, zinc, An alloy of platinum and one or more metals selected from the group consisting of tin is preferable. The platinum alloy may contain an intermetallic compound of a metal alloyed with platinum.

  The supported rate of platinum or platinum alloy (ratio of the mass of platinum or platinum alloy to the total mass of the supported catalyst) may be in the range of 20 to 80% by mass, particularly 30 to 55% by mass in order to obtain high output. preferable. If the loading rate is less than 20% by mass, sufficient output may not be obtained. If the loading rate exceeds 80% by mass, platinum or platinum alloy particles may not be supported on the carbon material serving as a carrier with good dispersibility.

Further, the primary particle diameter of platinum or platinum alloy is preferably 1 to 20 nm in order to obtain a highly active gas diffusion electrode, and in particular, a large surface area of platinum or platinum alloy can be ensured in terms of reaction activity. 5 nm is preferable. Moreover, it is preferable that platinum or a platinum alloy is contained in the range of 0.01-1.0 mg / cm < ² > in a catalyst particle.

The electrode catalyst layer 2 includes an ion conductive polymer electrolyte having a sulfonic acid group in addition to the supported catalyst. Usually, the supported catalyst is covered with the polymer electrolyte, and protons (H ⁺ ) move through a path where the polymer electrolyte is connected.

  As the ion conductive polymer electrolyte having a sulfonic acid group, since excellent adhesiveness with the solid polymer electrolyte membrane 1 can be obtained, a perfluoroalkylenesulfonic acid polymer compound is preferably used. Examples of the perfluoroalkylenesulfonic acid polymer compound include Nafion (trade name) manufactured by DuPont, Flemion (trade name) manufactured by Asahi Glass Co., Ltd., and Aciplex (trade name) manufactured by Asahi Kasei Corporation. As the ion conductive polymer electrolyte, instead of the perfluoroalkylenesulfonic acid polymer compound, an aromatic hydrocarbon compound such as a sulfonated polyarylene copolymer described in the present specification is mainly used. An ion conductive polymer electrolyte may be used.

  In the present embodiment, the membrane-electrode structure may consist of only the anode and cathode electrode catalyst layers 2 and 2 and the solid polymer electrolyte membrane 1 sandwiched between the electrode catalyst layers 2 and 2. More preferably, a gas diffusion layer 3 made of a conductive porous substrate such as carbon paper or carbon cloth is disposed outside the electrode catalyst layer 2 for both the anode and the cathode. In addition, this conductive porous substrate may be subjected to a water repellent treatment. Furthermore, a base layer imparted with water repellency may be formed on the gas diffusion layer 3 by applying a slurry in which carbon black and polytetrafluoroethylene (PTFE) particles are mixed. Since the gas diffusion layer 3 also functions as a current collector, in the present specification, when the gas diffusion layer 3 is provided, the gas diffusion layer 3 and the electrode catalyst layer 2 are collectively referred to as an electrode.

  In the polymer electrolyte fuel cell including the membrane-electrode structure shown in FIG. 1, a gas containing oxygen is supplied to the cathode, and a gas containing hydrogen is supplied to the anode. Specifically, for example, a separator in which a groove to be a gas flow path is formed is disposed outside both electrodes (gas diffusion layer 3) of the membrane-electrode structure, and the gas is allowed to flow through the gas flow path. To supply a gas serving as a fuel to the membrane-electrode structure.

  As a method for producing the membrane-electrode structure shown in FIG. 1, a method in which an electrode catalyst layer 2 is directly formed on a solid polymer electrolyte membrane 1 and sandwiched between gas diffusion layers 3 as necessary, gas diffusion such as carbon paper, etc. A method of forming the electrode catalyst layer 2 on the base material to be the layer 3 and bonding it to the solid polymer electrolyte membrane 1, and after forming the electrode catalyst layer 2 on the flat plate and transferring it to the solid polymer electrolyte membrane 1 Various methods such as a method of peeling the flat plate and sandwiching it with the gas diffusion layer 3 as required can be employed. More preferably, a method of directly forming the electrode catalyst layer 2 on the solid polymer electrolyte membrane 1 can be mentioned.

  As a method for forming the electrode catalyst layer 2, a dispersion in which a supported catalyst and a perfluoroalkylenesulfonic acid polymer compound having a sulfonic acid group are dispersed in a dispersion medium (a water repellent, a pore-forming agent as necessary) is used. A known method can be employed in which a solid agent electrolyte membrane 1, a gas diffusion layer 3 or a flat plate is formed by spraying, coating, filtration or the like. When the electrode catalyst layer 2 is not directly formed on the solid polymer electrolyte membrane 1, the electrode catalyst layer 2 and the solid polymer electrolyte membrane 1 are preferably joined by a hot press method, an adhesion method, or the like (for example, Patent Documents). 2).

  Next, examples of the present invention and comparative examples will be described.

  In this example, first, in a 1 liter three-necked flask equipped with a stirrer, thermometer, Dean-stark tube, nitrogen introducing tube, and cooling tube, 4,4 ′-(1,3-dimethylisobutylidene) bisphenol 27 was added. 0.04 g (100 mmol), 4,4′-dichlorobenzophenone 27.6 g (110 mmol), and potassium carbonate 20.0 g (145 mmol) were weighed. After nitrogen substitution, 300 ml of sulfolane and 150 ml of toluene were added and stirred. Thereafter, the reaction solution was heated to reflux at 150 ° C. using an oil bath. The water produced by the reaction was removed out of the system with a Dean-stark tube. After heating and refluxing for 3 hours, when almost no water was observed, toluene was removed out of the system through a Dean-stark tube. Thereafter, the reaction temperature was gradually raised to 200 ° C., and stirring was continued for 5 hours. Then, 7.53 g (30 mmol) of 4,4′-dichlorobenzophenone was added, and the reaction was further continued for 8 hours.

  The reaction solution was allowed to cool and then diluted by adding 100 ml of toluene. Inorganic salts insoluble in the reaction solution were filtered, and the filtrate was poured into 2 liters of methanol to precipitate the product. The precipitated product was filtered and dried, then dissolved in 250 ml of tetrahydrofuran (THF), poured into 2 liters of methanol, and reprecipitated. The precipitated white powder was filtered and dried to obtain 109 g of a polymer.

Next, about the obtained polymer, the number average molecular weight (Mn) of polystyrene conversion was calculated | required by GPC using THF as a solvent. Mn of the obtained polymer was 8,300. The obtained polymer is an oligomer represented by the following formula (I) as a result of conducting a structural analysis by 500 MHz-NMR (manufactured by BRUKER) using CDCl ₃ as a solvent in a 1 to 10 wt% solution. Was confirmed.

  Next, 31.5 g (78.6 mmol) of neopentyl 3- (2,5-dichlorobenzoyl) benzenesulfonate was added to a 1-liter three-necked flask equipped with a stirrer, a thermometer, and a nitrogen introduction tube, and the above formula (I) 12.0 g (1.44 mmol) of Mn8,300 oligomer represented by: 1.57 g (2.4 mmol) of bis (triphenylphosphine) nickel dichloride, 0.36 g (2.4 mmol) of sodium iodide, 8.39 g (32 mmol) of triphenylphosphine and 12.6 g (192 mmol) of zinc were weighed and replaced with dry nitrogen. To this, 96 ml of N, N-dimethylacetamide (DMAc) was added, and stirring was continued for 3 hours while maintaining the reaction temperature at 80 ° C. Then, 730 ml of DMAc was added for dilution, and insoluble matter was filtered off.

  The obtained solution was put into a 1 liter three-necked flask equipped with a stirrer, a thermometer, and a nitrogen introduction tube. This was heated to 115 ° C. and stirred, and 15.0 g (173 mmol) of lithium bromide was added. After stirring for 7 hours, the reaction solution was poured into 5 liters of acetone to precipitate the product. Subsequently, it was washed with 1M hydrochloric acid and pure water in this order and then dried to obtain 28.3 g of a polymer.

  About the obtained polymer, the weight average molecular weight (Mw) of polystyrene conversion was calculated | required by GPC using N-methyl-2-pyrrolidone (NMP) which added lithium bromide and phosphoric acid as a solvent. Mw of the obtained polymer was 160,000. The obtained polymer was represented by the following formula (II) as a result of structural analysis by 500 MHz-NMR (manufactured by BRUKER) using dimethyl sulfoxide (DMSO-d6) as a solvent in a 1 to 10 wt% solution. And sulfonated polyarylene.

  Next, a solution obtained by dissolving the sulfonated polymer obtained in this example in a mixed solvent in which NMP and methanol are mixed at a weight ratio of 1: 1 so that the solid content concentration is 15% by weight, The film was cast on a PET film using a doctor blade and dried at 120 ° C. for 1 hour to obtain a solid polymer electrolyte membrane having a dry film thickness of 40 μm.

  Next, platinum particles were supported on carbon black (furnace black) with an average diameter of 50 nm at a weight ratio of carbon black: platinum = 1: 1 to prepare catalyst particles. Next, the catalyst particles are placed in a perfluoroalkylenesulfonic acid polymer compound solution (Nafion (trade name) manufactured by DuPont) as an ion conductive binder at a weight ratio of ion conductive binder: catalyst particles = 8: 5. A catalyst paste was prepared by uniformly dispersing.

Next, a bar coater was applied on the PET film so that the platinum content was 0.5 mg / cm ² to prepare an electrode sheet.

  Next, the solid polymer electrolyte membrane is cut into a size of 10 cm × 10 cm, both sides of the solid polymer electrolyte membrane are sandwiched between the electrode sheets, and hot-pressed to obtain an electrode transfer membrane (CCM). It was. The hot pressing was performed at 160 ° C. and 5 MPa for 15 minutes.

  In addition, the membrane-electrode structure (electrode transfer film) obtained in this example has a gas diffusion layer made of carbon paper or the like laminated on an electrode, and a separator that also serves as a gas passage on the gas diffusion layer. By stacking, a polymer electrolyte fuel cell can be configured.

Next, the physical properties of the sulfonated polyarylene obtained in this example, the solid polymer electrolyte membrane, and the membrane-electrode structure were evaluated as follows. The results are shown in Table 1.
[Ion exchange capacity of sulfonated polyarylene]
First, the sulfonated polyarylene obtained in this example was washed until the water was washed with a pH of 4 to 6, the remaining free acid was sufficiently removed and dried, and a predetermined amount was weighed. Dissolved in a mixed solvent of THF / water. Next, titration was performed with a standard solution of NaOH using phenolphthalein as an indicator, and the ion exchange capacity was determined from the neutralization point.
[Proton conductivity of solid polymer electrolyte membrane]
First, the solid polymer electrolyte membrane obtained in this example was cut into a width of 5 mm to obtain a strip-shaped sample. Next, a platinum wire (diameter 0.5 mm) is pressed against the surface of the sample, the sample is held in a constant temperature and humidity device, and an AC impedance measurement between the platinum wires is performed at 85 ° C. and a relative humidity of 90%. The AC resistance was obtained. A SI1260 impedance analyzer (trade name) manufactured by Solartron was used as the resistance measurement device, and a small environmental tester SH-241 (trade name) manufactured by Espec was used as the constant temperature and humidity device. Five platinum wires were pressed at intervals of 5 mm, and the AC resistance was measured while changing the distance between the wires to 5 to 20 mm. Next, the specific resistance of the solid polymer electrolyte membrane was calculated from the distance between lines and the resistance gradient by the following formula, the AC impedance was calculated from the reciprocal of the specific resistance, and the proton conductivity was calculated from this impedance.

Specific resistance R (Ω · cm) = 0.5 (cm) × film thickness (cm) × resistance-to-resistance gradient (Ω / cm)
[Thermal deformation temperature of solid polymer electrolyte membrane]
First, the solid polymer electrolyte membrane obtained in this example was cut into 5 mm × 30 mm to obtain a strip-shaped sample. Next, the thermal deformation temperature of the sample was measured using a dynamic viscoelasticity measuring instrument (RSAII (trade name) manufactured by Rheometric Scientific F.E.).
[Adhesiveness of membrane-electrode structure]
First, the membrane-electrode structure (electrode transfer film) obtained in this example was put into a dew cycle tester (DCTH-200 (trade name) manufactured by Espec Corp.), and the conditions were 85 ° C. and relative humidity 95%. After heating to -20 ° C., a cooling cycle treatment for cooling to −20 ° C. was performed 20 times. Next, the membrane-electrode structure that had been subjected to the cooling and heating cycle treatment was cut into 1.0 cm × 5.0 cm to obtain strip-shaped samples. Next, one surface of the sample is attached to an aluminum plate with a double-sided adhesive tape, the adhesive tape is attached to the other surface, and the adhesive tape is pulled at a speed of 50 mm / min in the direction of reversing, the membrane-electrode The electrode was peeled from the solid polymer electrolyte membrane of the structure. The electrode was peeled off using an SPG weight measuring machine (trade name: HPC.A50.500) manufactured by Toyoko Engineering. Next, an image of the surface of the solid polymer electrolyte membrane from which the electrode has been peeled off is captured using an Epson scanner GT-8200UF (trade name) and binarized to obtain an area where the electrode remains. Calculated. Next, the ratio of the area where the electrode remained to the total area of the surface of the solid polymer electrolyte membrane was defined as the electrode adhesion rate according to the following formula.

  Electrode adhesion rate (%) = (electrode remaining area) / (total area of solid polymer electrolyte membrane) × 100

  In this example, first, 32.6 g (100 mmol) of 4,4′-decylidenebisphenol was added to a 1 liter three-necked flask equipped with a stirrer, thermometer, Dean-stark tube, nitrogen introduction tube, and cooling tube. , 4′-dichlorobenzophenone 27.6 g (110 mmol) and potassium carbonate 20.0 g (145 mmol) were weighed. After nitrogen substitution, 300 ml of sulfolane and 150 ml of toluene were added and stirred. Thereafter, the reaction solution was heated to reflux at 150 ° C. using an oil bath. The water produced by the reaction was removed out of the system with a Dean-stark tube. After heating and refluxing for 3 hours, when almost no water was observed, toluene was removed out of the system through a Dean-stark tube. Thereafter, the reaction temperature was gradually raised to 200 ° C., and stirring was continued for 5 hours. Then, 7.53 g (30 mmol) of 4,4′-dichlorobenzophenone was added, and the reaction was further continued for 8 hours.

  The reaction solution was allowed to cool and then diluted by adding 100 ml of toluene. Inorganic salts insoluble in the reaction solution were filtered, and the filtrate was poured into 2 liters of methanol to precipitate the product. The precipitated product was filtered and dried, then dissolved in 250 ml of THF, and poured into 2 liters of methanol for reprecipitation. The precipitated white powder was filtered and dried to obtain 45.5 g of a polymer.

  Next, about the obtained polymer, THF was used as a solvent and Mn of polystyrene conversion was calculated | required by GPC. Mn of the obtained polymer was 7,800. The obtained polymer was subjected to structural analysis in exactly the same manner as in Example 1. As a result, it was confirmed that the polymer was an oligomer represented by the following formula (III).

  Next, 31.5 g (78.6 mmol) of neopentyl 3- (2,5-dichlorobenzoyl) benzenesulfonate was added to a three-necked flask equipped with a stirrer, a thermometer, and a nitrogen introduction tube, and the above formula (III) 12.0 g (1.54 mmol) of Mn7,800 oligomer represented by: 1.57 g (2.4 mmol) of bis (triphenylphosphine) nickel dichloride, 0.36 g (2.4 mmol) of sodium iodide, 8.39 g (32 mmol) of triphenylphosphine and 12.6 g (192 mmol) of zinc were weighed and replaced with dry nitrogen. To this, 96 ml of DMAc was added, and stirring was continued for 3 hours while maintaining the reaction temperature at 80 ° C. Then, 168 ml of DMAc was added for dilution, and insoluble matter was filtered off.

  The obtained solution was put into a 1 liter three-necked flask equipped with a stirrer, a thermometer, and a nitrogen introduction tube. This was heated to 115 ° C. and stirred, and 15.0 g (173 mmol) of lithium bromide was added. After stirring for 7 hours, the reaction solution was poured into 5 liters of acetone to precipitate the product. Subsequently, it was washed with 1M hydrochloric acid and pure water in this order and dried to obtain 29.0 g of a polymer.

  About the obtained polymer, MMP of polystyrene conversion was calculated | required by GPC using NMP which added lithium bromide and phosphoric acid as a solvent. Mw of the obtained polymer was 183,000. The obtained polymer was subjected to structural analysis in exactly the same manner as in Example 1. As a result, it was confirmed that the polymer was a sulfonated polyarylene represented by the following formula (IV).

  Next, a solid polymer electrolyte membrane and a membrane-electrode structure (electrode transfer membrane) were prepared in the same manner as in Example 1 except that the sulfonated polymer obtained in this example was used.

  Next, the physical properties of the sulfonated polyarylene obtained in this example, the solid polymer electrolyte membrane, and the membrane-electrode structure were evaluated in the same manner as in Example 1. The results are shown in Table 1.

  In this example, first, 4,4 ′-(1,3-dimethylbutylidene) bisphenol was added to a 1 liter three-necked flask equipped with a stirrer, a thermometer, a Dean-stark tube, a nitrogen introduction tube, and a cooling tube. 0 g (100 mmol), 2,6-dichlorobenzonitrile 18.9 g (110 mmol), and potassium carbonate 20.0 g (145 mmol) were weighed. After nitrogen substitution, 300 ml of sulfolane and 150 ml of toluene were added and stirred. Thereafter, the reaction solution was heated to reflux at 150 ° C. using an oil bath. The water produced by the reaction was removed out of the system with a Dean-stark tube. After heating and refluxing for 3 hours, when almost no water was observed, toluene was removed out of the system through a Dean-stark tube. Thereafter, the reaction temperature was gradually raised to 200 ° C., and stirring was continued for 5 hours. Then, 5.16 g (30 mmol) of 2,6-dichlorobenzonitrile was added, and the reaction was further continued for 8 hours.

  The reaction solution was allowed to cool and then diluted by adding 100 ml of toluene. Inorganic salts insoluble in the reaction solution were filtered, and the filtrate was poured into 2 liters of methanol to precipitate the product. The precipitated product was filtered and dried, then dissolved in 250 ml of THF, and poured into 2 liters of methanol for reprecipitation. The precipitated white powder was filtered and dried to obtain 37.3 g of a polymer.

  Next, about the obtained polymer, THF was used as a solvent and Mn of polystyrene conversion was calculated | required by GPC. Mn of the obtained polymer was 8,000. The obtained polymer was subjected to structural analysis in exactly the same manner as in Example 1. As a result, it was confirmed that the polymer was an oligomer represented by the following formula (V).

  Next, 31.5 g (78.6 mmol) of neopentyl 3- (2,5-dichlorobenzoyl) benzenesulfonate was added to a 1-liter three-necked flask equipped with a stirrer, a thermometer, and a nitrogen introduction tube, and the above formula (V) 12.0 g (1.50 mmol) of Mn8,000 oligomer represented by: 1.57 g (2.4 mmol) of bis (triphenylphosphine) nickel dichloride, 0.36 g (2.4 mmol) of sodium iodide, 8.39 g (32 mmol) of triphenylphosphine and 12.6 g (192 mmol) of zinc were weighed and replaced with dry nitrogen. To this, 96 ml of DMAc was added, and stirring was continued for 3 hours while maintaining the reaction temperature at 80 ° C. Then, 168 ml of DMAc was added for dilution, and insoluble matter was filtered off.

  The obtained solution was put into a 1 liter three-necked flask equipped with a stirrer, a thermometer, and a nitrogen introduction tube. This was heated to 115 ° C. and stirred, and 15.0 g (173 mmol) of lithium bromide was added. After stirring for 7 hours, the reaction solution was poured into 5 liters of acetone to precipitate the product. Subsequently, it was washed with 1M hydrochloric acid and pure water in this order and dried to obtain 29.8 g of a polymer.

  About the obtained polymer, MMP of polystyrene conversion was calculated | required by GPC using NMP which added lithium bromide and phosphoric acid as a solvent. Mw of the obtained polymer was 182,000. The obtained polymer was subjected to structural analysis in exactly the same manner as in Example 1. As a result, it was confirmed that the polymer was a sulfonated polyarylene represented by the following formula (VI).

  Next, a solid polymer electrolyte membrane and a membrane-electrode structure (electrode transfer membrane) were prepared in the same manner as in Example 1 except that the sulfonated polymer obtained in this example was used.

  Next, the physical properties of the sulfonated polyarylene obtained in this example, the solid polymer electrolyte membrane, and the membrane-electrode structure were evaluated in the same manner as in Example 1. The results are shown in Table 1.

  In this example, first, 29.8 g of 4,4 ′-(1-methyl-heptylidene) bisphenol was added to a 1-liter three-necked flask equipped with a stirrer, a thermometer, a Dean-stark tube, a nitrogen introduction tube, and a cooling tube. 100 mmol), 18.9 g (110 mmol) of 2,6-dichlorobenzonitrile, and 20.0 g (145 mmol) of potassium carbonate were weighed. After nitrogen substitution, 300 ml of sulfolane and 150 ml of toluene were added and stirred. Thereafter, the reaction solution was heated to reflux at 150 ° C. using an oil bath. The water produced by the reaction was removed out of the system with a Dean-stark tube. After heating and refluxing for 3 hours, when almost no water was observed, toluene was removed out of the system through a Dean-stark tube. Thereafter, the reaction temperature was gradually raised to 200 ° C., and stirring was continued for 5 hours. Then, 5.16 g (30 mmol) of 2,6-dichlorobenzonitrile was added, and the reaction was further continued for 8 hours.

  The reaction solution was allowed to cool and then diluted by adding 100 ml of toluene. Inorganic salts insoluble in the reaction solution were filtered, and the filtrate was poured into 2 liters of methanol to precipitate the product. The precipitated product was filtered and dried, then dissolved in 250 ml of THF, and poured into 2 liters of methanol for reprecipitation. The precipitated white powder was filtered and dried to obtain 37.3 g of a polymer.

  Next, about the obtained polymer, THF was used as a solvent and Mn of polystyrene conversion was calculated | required by GPC. Mn of the obtained polymer was 8,000. The obtained polymer was subjected to structural analysis in exactly the same manner as in Example 1. As a result, it was confirmed that the polymer was an oligomer represented by the following formula (VII).

  Next, 31.5 g (78.5 mmol) of neopentyl 3- (2,5-dichlorobenzoyl) benzenesulfonate was added to a 1-liter three-necked flask equipped with a stirrer, a thermometer, and a nitrogen inlet tube, and the above formula (VII) 12.0 g (1.50 mmol) of Mn8,000 oligomer represented by: 1.57 g (2.4 mmol) of bis (triphenylphosphine) nickel dichloride, 0.36 g (2.4 mmol) of sodium iodide, 8.39 g (32 mmol) of triphenylphosphine and 12.6 g (192 mmol) of zinc were weighed and replaced with dry nitrogen. To this, 96 ml of DMAc was added, and stirring was continued for 3 hours while maintaining the reaction temperature at 80 ° C. Then, 168 ml of DMAc was added for dilution, and insoluble matter was filtered off.

  The obtained solution was put into a 1 liter three-necked flask equipped with a stirrer, a thermometer, and a nitrogen introduction tube. This was heated to 115 ° C. and stirred, and 15.0 g (173 mmol) of lithium bromide was added. After stirring for 7 hours, the reaction solution was poured into 5 liters of acetone to precipitate the product. Subsequently, it was washed with 1M hydrochloric acid and pure water in this order and dried to obtain 29.8 g of a polymer.

  About the obtained polymer, MMP of polystyrene conversion was calculated | required by GPC using NMP which added lithium bromide and phosphoric acid as a solvent. Mw of the obtained polymer was 180,000. The obtained polymer was subjected to structural analysis in exactly the same manner as in Example 1. As a result, it was confirmed that the polymer was a sulfonated polyarylene represented by the following formula (VIII).

  Next, a solid polymer electrolyte membrane and a membrane-electrode structure (electrode transfer membrane) were prepared in the same manner as in Example 1 except that the sulfonated polymer obtained in this example was used.

  Next, the physical properties of the sulfonated polyarylene obtained in this example, the solid polymer electrolyte membrane, and the membrane-electrode structure were evaluated in the same manner as in Example 1. The results are shown in Table 1.

  In this example, first, 4,4 ′-(1,3-dimethylisobutylidene) bisphenol 61 was added to a 1-liter three-necked flask equipped with a stirrer, thermometer, Dean-stark tube, nitrogen introduction tube, and cooling tube. 0.1 g (226 mmol), 4,4′-dichlorodiphenylsulfone 61.1 g (210 mmol), and potassium carbonate 40.6 g (294 mmol) were weighed. After nitrogen substitution, 340 ml of sulfolane and 170 ml of toluene were added and stirred. Thereafter, the reaction solution was heated to reflux at 150 ° C. using an oil bath. The water produced by the reaction was removed out of the system with a Dean-stark tube. After heating and refluxing for 3 hours, when almost no water was observed, toluene was removed out of the system through a Dean-stark tube. Thereafter, the reaction temperature was gradually raised to 200 ° C., and stirring was continued for 5 hours. Then, 12.4 g (48 mmol) of 4,4′-dichlorobenzophenone and 4,4 ′-(1,3-dimethylisobutylidene) were obtained. ) 4.33 g (16 mmol) of bisphenol and 170 ml of toluene were added, and the mixture was further reacted for 5 hours. During this time, the reaction temperature was gradually increased from 150 ° C. to 200 ° C., and the reaction was advanced while removing toluene out of the system.

  The reaction solution was allowed to cool and then diluted by adding 200 ml of toluene. Inorganic salts insoluble in the reaction solution were filtered, and the filtrate was poured into 4 liters of methanol to precipitate the product. The precipitated product was filtered and dried, then dissolved in 400 ml of THF, and poured into 4 liters of methanol for reprecipitation. The precipitated white powder was filtered and dried to obtain 122 g of a polymer.

  Next, about the obtained polymer, THF was used as a solvent and Mn of polystyrene conversion was calculated | required by GPC. Mn of the obtained polymer was 8,000. The obtained polymer was subjected to structural analysis in exactly the same manner as in Example 1. As a result, it was confirmed that the polymer was an oligomer represented by the following formula (IX).

  Next, 31.5 g (78.6 mmol) of neopentyl 3- (2,5-dichlorobenzoyl) benzenesulfonate was added to a 1-liter three-necked flask equipped with a stirrer, a thermometer, and a nitrogen inlet tube, and the above formula (IX) 12.0 g (1.50 mmol) of Mn8,000 oligomer represented by: 1.57 g (2.4 mmol) of bis (triphenylphosphine) nickel dichloride, 0.36 g (2.4 mmol) of sodium iodide, 8.39 g (32 mmol) of triphenylphosphine and 12.6 g (192 mmol) of zinc were weighed and replaced with dry nitrogen. To this, 96 ml of DMAc was added, and stirring was continued for 3 hours while maintaining the reaction temperature at 80 ° C. Then, 168 ml of DMAc was added for dilution, and insoluble matter was filtered off.

  The obtained solution was put into a 1 liter three-necked flask equipped with a stirrer, a thermometer, and a nitrogen introduction tube. This was heated to 115 ° C. and stirred, and 15.0 g (173 mmol) of lithium bromide was added. After stirring for 7 hours, the reaction solution was poured into 5 liters of acetone to precipitate the product. Subsequently, it was washed with 1M hydrochloric acid and pure water in this order and dried to obtain 29.8 g of a polymer.

  About the obtained polymer, MMP of polystyrene conversion was calculated | required by GPC using NMP which added lithium bromide and phosphoric acid as a solvent. Mw of the obtained polymer was 180,000. The obtained polymer was subjected to structural analysis in exactly the same manner as in Example 1. As a result, it was confirmed that the polymer was a sulfonated polyarylene represented by the following formula (X).

  Next, a solid polymer electrolyte membrane and a membrane-electrode structure (electrode transfer membrane) were prepared in the same manner as in Example 1 except that the sulfonated polymer obtained in this example was used.

  Next, the physical properties of the sulfonated polyarylene obtained in this example, the solid polymer electrolyte membrane, and the membrane-electrode structure were evaluated in the same manner as in Example 1. The results are shown in Table 1.

  In this example, first, 26.8 g (100 mmol) of 4,4′-cyclohexylidenebisphenol was added to a 1 liter three-necked flask equipped with a stirrer, thermometer, Dean-stark tube, nitrogen introduction tube, and cooling tube. 1,4-bis (4-chlorobenzoyl) benzene 39.1 g (110 mmol) and potassium carbonate 20.0 g (145 mmol) were weighed. After nitrogen substitution, 300 ml of sulfolane and 150 ml of toluene were added and stirred. Thereafter, the reaction solution was heated to reflux at 150 ° C. using an oil bath. The water produced by the reaction was removed out of the system with a Dean-stark tube. After heating and refluxing for 3 hours, when almost no water was observed, toluene was removed out of the system through a Dean-stark tube. Thereafter, the reaction temperature was gradually raised to 200 ° C., and stirring was continued for 5 hours. Then, 10.7 g (30 mmol) of 1,3-bis (4-chlorobenzoyl) benzene was added, and the reaction was further continued for 8 hours.

  The reaction solution was allowed to cool and then diluted by adding 100 ml of toluene. Inorganic salts insoluble in the reaction solution were filtered, and the filtrate was poured into 2 liters of methanol to precipitate the product. The precipitated product was filtered and dried, then dissolved in 250 ml of THF, and poured into 2 liters of methanol for reprecipitation. The precipitated white powder was filtered and dried to obtain 52.2 g of a polymer.

  Next, about the obtained polymer, Mn was calculated | required by GPC using THF as a solvent. Mn of the obtained polymer was 8,800. The obtained polymer was subjected to structural analysis in exactly the same manner as in Example 1. As a result, it was confirmed that the polymer was an oligomer represented by the following formula (XI).

  Next, 31.5 g (78.6 mmol) of neopentyl 3- (2,5-dichlorobenzoyl) benzenesulfonate was added to a 1-liter three-necked flask equipped with a stirrer, a thermometer, and a nitrogen introduction tube, and the above formula (XI) 12.0 g (1.36 mmol) of an oligomer of Mn8,800, 1.57 g (2.4 mmol) of bis (triphenylphosphine) nickel dichloride, 0.36 g (2.4 mmol) of sodium iodide, 8.39 g (32 mmol) of triphenylphosphine and 12.6 g (192 mmol) of zinc were weighed and replaced with dry nitrogen. To this, 96 ml of DMAc was added, and stirring was continued for 3 hours while maintaining the reaction temperature at 80 ° C. Then, 168 ml of DMAc was added for dilution, and insoluble matter was filtered off.

  The obtained solution was put into a 1 liter three-necked flask equipped with a stirrer, a thermometer, and a nitrogen introduction tube. This was heated to 115 ° C. and stirred, and 15.0 g (173 mmol) of lithium bromide was added. After stirring for 7 hours, the reaction solution was poured into 5 liters of acetone to precipitate the product. Next, the mixture was washed with 1M hydrochloric acid and pure water in that order and dried to obtain 29.5 g of a polymer.

  About the obtained polymer, MMP of polystyrene conversion was calculated | required by GPC using NMP which added lithium bromide and phosphoric acid as a solvent. Mw of the obtained polymer was 180,000. The obtained polymer was subjected to structural analysis in exactly the same manner as in Example 1. As a result, it was confirmed that the polymer was a sulfonated polyarylene represented by the following formula (XII).

  Next, a solid polymer electrolyte membrane and a membrane-electrode structure (electrode transfer membrane) were prepared in the same manner as in Example 1 except that the sulfonated polymer obtained in this example was used.

  Next, the physical properties of the sulfonated polyarylene obtained in this example, the solid polymer electrolyte membrane, and the membrane-electrode structure were evaluated in the same manner as in Example 1. The results are shown in Table 1.

  In this example, first, 27.8 g (85 mmol) of 4,4′-decylidenebisphenol was added to a 1-liter three-necked flask equipped with a stirrer, a thermometer, a Dean-stark tube, a nitrogen introduction tube, and a cooling tube. , 9-bis (4-hydroxyphenyl) fluorene 5.3 g (15 mmol), 4,4′-dichlorobenzophenone 27.6 g (110 mmol), potassium carbonate 20 g (145 mmol) were weighed. After nitrogen substitution, 300 ml of sulfolane and 150 ml of toluene were added and stirred. Thereafter, the reaction solution was heated to reflux at 150 ° C. using an oil bath. The water produced by the reaction was removed out of the system with a Dean-stark tube. After heating and refluxing for 3 hours, when almost no water was observed, toluene was removed out of the system through a Dean-stark tube. Thereafter, the reaction temperature was gradually raised to 200 ° C., and stirring was continued for 5 hours. Then, 7.53 g (30 mmol) of 4,4′-dichlorobenzophenone was added, and the reaction was further continued for 8 hours.

  The reaction solution was allowed to cool and then diluted by adding 100 ml of toluene. Inorganic salts insoluble in the reaction solution were filtered, and the filtrate was poured into 2 liters of methanol to precipitate the product. The precipitated product was filtered and dried, then dissolved in 250 ml of THF, and poured into 2 liters of methanol for reprecipitation. The precipitated white powder was filtered and dried to obtain 41.2 g of a polymer.

  Next, about the obtained polymer, THF was used as a solvent and Mn of polystyrene conversion was calculated | required by GPC. Mn of the obtained polymer was 9,200. The obtained polymer was subjected to structural analysis in exactly the same manner as in Example 1. As a result, it was confirmed that the polymer was an oligomer represented by the following formula (XIII).

  Next, in a 1 liter three-necked flask equipped with a stirrer, a thermometer, and a nitrogen introduction tube, 31.5 g (78.6 mmol) of neopentyl 3- (2,5-dichlorobenzoyl) benzenesulfonate, the above formula (XIII) 12.0 g (1.36 mmol) of Mn9,200 oligomer represented by the formula: 1.57 g (2.4 mmol) of bis (triphenylphosphine) nickel dichloride, 0.36 g (2.4 mmol) of sodium iodide, 8.39 g (32 mmol) of triphenylphosphine and 12.6 g (192 mmol) of zinc were weighed and replaced with dry nitrogen. To this, 96 ml of DMAc was added, and stirring was continued for 3 hours while maintaining the reaction temperature at 80 ° C. Then, 168 ml of DMAc was added for dilution, and insoluble matter was filtered off.

  The obtained solution was put into a 1 liter three-necked flask equipped with a stirrer, a thermometer, and a nitrogen introduction tube. This was heated to 115 ° C. and stirred, and 15.0 g (173 mmol) of lithium bromide was added. After stirring for 7 hours, the reaction solution was poured into 5 liters of acetone to precipitate the product. Subsequently, it was washed with 1M hydrochloric acid and pure water in this order and dried to obtain 29.6 g of a polymer.

  About the obtained polymer, MMP of polystyrene conversion was calculated | required by GPC using NMP which added lithium bromide and phosphoric acid as a solvent. Mw of the obtained polymer was 187,000. The obtained polymer was subjected to structural analysis in exactly the same manner as in Example 1. As a result, it was confirmed that the polymer was a sulfonated polyarylene represented by the following formula (XIV).

  Next, a solid polymer electrolyte membrane and a membrane-electrode structure (electrode transfer membrane) were prepared in the same manner as in Example 1 except that the sulfonated polymer obtained in this example was used.

Next, the physical properties of the sulfonated polyarylene obtained in this example, the solid polymer electrolyte membrane, and the membrane-electrode structure were evaluated in the same manner as in Example 1. The results are shown in Table 1.
[Comparative Example 1]
In this comparative example, first, 2,2-bis (4-hydroxyphenyl) -1,1,1 was placed in a 1 liter three-necked flask equipped with a stirrer, thermometer, Dean-stark tube, nitrogen introduction tube, and cooling tube. , 3,3,3-hexafluoropropane (bisphenol AF) 50.4 g (150 mmol), 4,4′-dichlorobenzophenone 40.2 g (160 mmol), potassium carbonate 27.0 g (200 mmol), sulfolane 300 ml 150 ml of toluene was weighed out. This was stirred under a nitrogen atmosphere and reacted at 130 ° C. using an oil bath. When water produced by the reaction was azeotroped with toluene and reacted while being removed out of the system through a Dean-stark tube, almost no water was produced in about 3 hours. Thereafter, the reaction temperature was gradually increased from 130 ° C. to 200 ° C., during which time most of the toluene was removed out of the system. After stirring at 200 ° C. for 10 hours, 16.1 g (64 mmol) of 4,4′-dichlorobenzophenone was added, and the reaction was further continued for 5 hours.

  After the reaction solution was allowed to cool, the by-product inorganic compound precipitate was filtered, and the filtrate was poured into 4 liters of methanol to precipitate the product. The precipitated product was filtered and dried, then dissolved in 300 ml of THF, poured into 4 liters of methanol and reprecipitated to obtain 65.7 g of a polymer.

  Next, about the obtained polymer, Mn was calculated | required by GPC using THF as a solvent. Mn of the obtained polymer was 11,200. The obtained polymer was subjected to structural analysis in exactly the same manner as in Example 1. As a result, it was confirmed that the polymer was an oligomer represented by the following formula (XV).

  Next, 39.5 g (98.7 mmol) of neopentyl 3- (2,5-dichlorobenzoyl) benzenesulfonate was added to a 1-liter three-necked flask equipped with a stirrer, a thermometer, and a nitrogen inlet tube, and the above formula (XV) 15.1 g (1.35 mmol) of an oligomer of Mn11,200 represented by: 1.96 g (3.00 mmol) of bis (triphenylphosphine) nickel dichloride, 0.45 g (3.0 mmol) of sodium iodide, 10.5 g (40.0 mmol) of triphenylphosphine and 15.7 g (240 mmol) of zinc were weighed and replaced with dry nitrogen. To this, 126 ml of DMAc was added, and stirring was continued for 3 hours while maintaining the reaction temperature at 80 ° C. Then, 168 ml of DMAc was added for dilution, and insoluble matter was filtered off.

  The obtained solution was put into a 1 liter three-necked flask equipped with a stirrer, a thermometer, and a nitrogen introduction tube. This was heated to 115 ° C. and stirred, and 18.8 g (217 mmol) of lithium bromide was added. After stirring for 7 hours, the reaction solution was poured into 5 liters of acetone to precipitate the product. Subsequently, it wash | cleaned in order of 1M hydrochloric acid and a pure water, Then, it dried and the polymer 38.9g was obtained.

  About the obtained polymer, MMP of polystyrene conversion was calculated | required by GPC using NMP which added lithium bromide and phosphoric acid as a solvent. Mw of the obtained polymer was 178,000. The obtained polymer was subjected to structural analysis in exactly the same manner as in Example 1. As a result, it was confirmed that the polymer was a sulfonated polyarylene represented by the following formula (XVI).

  Next, a solid polymer electrolyte membrane and a membrane-electrode structure (electrode transfer membrane) were prepared in the same manner as in Example 1 except that the sulfonated polymer obtained in this comparative example was used.

Next, the physical properties of the sulfonated polyarylene obtained in this comparative example, the solid polymer electrolyte membrane, and the membrane-electrode structure were evaluated in the same manner as in Example 1. The results are shown in Table 1.
[Comparative Example 2]
In this comparative example, first, in a 1 liter three-necked flask equipped with a stirrer, thermometer, Dean-stark tube, nitrogen introduction tube, and cooling tube, 20.2 g (100 mmol) of methylenebisphenol and 2,6-dichlorobenzonitrile were added. 18.9 g (110 mmol) and 20.0 g (145 mmol) of potassium carbonate were weighed out. After nitrogen substitution, 300 ml of sulfolane and 150 ml of toluene were added and stirred. Thereafter, the reaction solution was heated to reflux at 150 ° C. using an oil bath. The water produced by the reaction was removed out of the system with a Dean-stark tube. After heating and refluxing for 3 hours, when almost no water was observed, toluene was removed out of the system through a Dean-stark tube. Thereafter, the reaction temperature was gradually raised to 200 ° C., and stirring was continued for 5 hours. Then, 5.16 g (30 mmol) of 2,6-dichlorobenzonitrile was added, and the reaction was further continued for 8 hours.

  The reaction solution was allowed to cool and then diluted by adding 100 ml of toluene. Inorganic salts insoluble in the reaction solution were filtered, and the filtrate was poured into 2 liters of methanol to precipitate the product. The precipitated product was filtered and dried, then dissolved in 250 ml of THF, and poured into 2 liters of methanol for reprecipitation. The precipitated white powder was filtered and dried to obtain 28.3 g of a polymer.

  Next, about the obtained polymer, THF was used as a solvent and Mn of polystyrene conversion was calculated | required by GPC. Mn of the obtained polymer was 7,900. The obtained polymer was subjected to structural analysis in exactly the same manner as in Example 1. As a result, it was confirmed that the polymer was an oligomer represented by the following formula (XVII).

  Next, in a 1 liter three-necked flask equipped with a stirrer, a thermometer, and a nitrogen introduction tube, 31.5 g (78.5 mmol) of neopentyl 3- (2,5-dichlorobenzoyl) benzenesulfonate, the above formula (XVII) 12.0 g (1.50 mmol) of Mn7,900 oligomer represented by the formula: 1.57 g (2.4 mmol) of bis (triphenylphosphine) nickel dichloride, 0.36 g (2.4 mmol) of sodium iodide, 8.39 g (32 mmol) of triphenylphosphine and 12.6 g (192 mmol) of zinc were weighed and replaced with dry nitrogen. To this, 96 ml of DMAc was added, and stirring was continued for 3 hours while maintaining the reaction temperature at 80 ° C. Then, 168 ml of DMAc was added for dilution, and insoluble matter was filtered off.

  The obtained solution was put into a 1 liter three-necked flask equipped with a stirrer, a thermometer, and a nitrogen introduction tube. This was heated to 115 ° C. and stirred, and 15.0 g (173 mmol) of lithium bromide was added. After stirring for 7 hours, the reaction solution was poured into 5 liters of acetone to precipitate the product. Subsequently, it was washed with 1M hydrochloric acid and pure water in this order and dried to obtain 29.4 g of a polymer.

  About the obtained polymer, MMP of polystyrene conversion was calculated | required by GPC using NMP which added lithium bromide and phosphoric acid as a solvent. Mw of the obtained polymer was 176,000. The obtained polymer was subjected to structural analysis in exactly the same manner as in Example 1. As a result, it was confirmed that the polymer was a sulfonated polyarylene represented by the following formula (XVIII).

  Next, a solid polymer electrolyte membrane and a membrane-electrode structure (electrode transfer membrane) were prepared in the same manner as in Example 1 except that the sulfonated polymer obtained in this comparative example was used.

Next, the physical properties of the sulfonated polyarylene obtained in this comparative example, the solid polymer electrolyte membrane, and the membrane-electrode structure were evaluated in the same manner as in Example 1. The results are shown in Table 1.
[Comparative Example 3]
In this comparative example, first, a 1 liter three-necked flask equipped with a stirrer, a thermometer, a Dean-stark tube, a nitrogen introduction tube, and a cooling tube was charged with 18.6 g (100 mmol) of biphenol, 4,4′-dichlorobenzophenone 27 0.6 g (110 mmol) and 20.0 g (145 mmol) of potassium carbonate were weighed. After nitrogen substitution, 300 ml of sulfolane and 150 ml of toluene were added and stirred. Thereafter, the reaction solution was heated to reflux at 150 ° C. using an oil bath. The water produced by the reaction was removed out of the system with a Dean-stark tube. After heating and refluxing for 3 hours, when almost no water was observed, toluene was removed out of the system through a Dean-stark tube. Thereafter, the reaction temperature was gradually raised to 200 ° C., and stirring was continued for 5 hours. Then, 7.53 g (30 mmol) of 4,4′-dichlorobenzophenone was added, and the reaction was further continued for 8 hours.

  The reaction solution was allowed to cool and then diluted by adding 100 ml of toluene. Inorganic salts insoluble in the reaction solution were filtered, and the filtrate was poured into 2 liters of methanol to precipitate the product. The precipitated product was filtered and dried, then dissolved in 250 ml of THF, and poured into 2 liters of methanol for reprecipitation. The precipitated white powder was filtered and dried to obtain 33.3 g of a polymer.

  Next, about the obtained polymer, THF was used as a solvent and Mn of polystyrene conversion was calculated | required by GPC. Mn of the obtained polymer was 8,400. The obtained polymer was subjected to structural analysis in exactly the same manner as in Example 1. As a result, it was confirmed that the polymer was an oligomer represented by the following formula (XIX).

  Next, in a 1-liter three-necked flask equipped with a stirrer, a thermometer, and a nitrogen introduction tube, 31.5 g (78.6 mmol) of neopentyl 3- (2,5-dichlorobenzoyl) benzenesulfonate, the above formula (XIX) 12.0 g (1.42 mmol) of Mn8,400 oligomer represented by: 1.57 g (2.4 mmol) of bis (triphenylphosphine) nickel dichloride, 0.36 g (2.4 mmol) of sodium iodide, 8.39 g (32 mmol) of triphenylphosphine and 12.6 g (192 mmol) of zinc were weighed and replaced with dry nitrogen. To this, 96 ml of DMAc was added, and stirring was continued for 3 hours while maintaining the reaction temperature at 80 ° C. Then, 168 ml of DMAc was added for dilution, and insoluble matter was filtered off.

  The obtained solution was put into a 1 liter three-necked flask equipped with a stirrer, a thermometer, and a nitrogen introduction tube. This was heated to 115 ° C. and stirred, and 15.0 g (173 mmol) of lithium bromide was added. After stirring for 7 hours, the reaction solution was poured into 5 liters of acetone to precipitate the product. Subsequently, it was washed with 1M hydrochloric acid and pure water in this order and then dried to obtain 29.9 g of a polymer.

  About the obtained polymer, MMP of polystyrene conversion was calculated | required by GPC using NMP which added lithium bromide and phosphoric acid as a solvent. Mw of the obtained polymer was 186,000. The obtained polymer was subjected to structural analysis in exactly the same manner as in Example 1. As a result, it was confirmed that the polymer was a sulfonated polyarylene represented by the following formula (XX).

  Next, a solid polymer electrolyte membrane and a membrane-electrode structure (electrode transfer membrane) were prepared in the same manner as in Example 1 except that the sulfonated polymer obtained in this comparative example was used.

  Next, the physical properties of the sulfonated polyarylene obtained in this comparative example, the solid polymer electrolyte membrane, and the membrane-electrode structure were evaluated in the same manner as in Example 1. The results are shown in Table 1.

  From Table 1, the sulfonated polyarylene (Examples 1 to 7) having an alkyl group having 2 or more carbon atoms in the side chain is a sulfonated polyarylene having no alkyl group having 2 or more carbon atoms in the side chain (Comparative Example 1). Solid polymer electrolyte membranes (Examples 1 to 7) made of sulfonated polyarylene having an ion exchange capacity equivalent to that of ˜3) and having an alkyl group having 2 or more carbon atoms in the side chain have 2 carbon atoms in the side chain. It is apparent that the proton conductivity equivalent to that of the solid polymer electrolyte membrane (Comparative Examples 1 to 3) made of sulfonated polyarylene not having the above alkyl group is provided.

  Moreover, from Table 1, the solid polymer electrolyte membranes (Examples 1 to 7) made of sulfonated polyarylene having an alkyl group having 2 or more carbon atoms in the side chain have an alkyl group having 2 or more carbon atoms in the side chain. Solid polymer electrolyte membrane comprising a sulfonated polyarylene having a lower heat distortion temperature and having an alkyl group having 2 or more carbon atoms in the side chain as compared with a solid polymer electrolyte membrane comprising sulfonated polyarylene (Comparative Examples 1 to 3) Membrane-electrode structures using electrolyte membranes (Examples 1 to 7) are membrane-electrode structures using a solid polymer electrolyte membrane made of a sulfonated polyarylene having no alkyl group having 2 or more carbon atoms in the side chain. It is clear that the adhesion of the electrode is superior to the body (Comparative Examples 1 to 3).

BRIEF DESCRIPTION OF THE DRAWINGS Explanatory sectional drawing which shows one Embodiment of the membrane-electrode structure of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Solid polymer electrolyte membrane, 2 ... Electrode catalyst layer, 3 ... Gas diffusion layer.

Claims (3)

In a membrane-electrode structure for a polymer electrolyte fuel cell in which a polymer electrolyte membrane is sandwiched between a pair of electrodes containing a catalyst,
The solid polymer electrolyte membrane is a polyarylene copolymer sulfone having a first repeating unit represented by the following general formula (1) and a second repeating unit represented by the following general formula (2). A membrane-electrode structure for a polymer electrolyte fuel cell, comprising:

A in the second repeating unit represented by the general formula (2) may be —CR ¹ R ² — (R ¹ and R ² may be the same as or different from each other, but at least one of them has 2 carbon atoms. When the above alkyl group or a halogenated alkyl group having 2 or more carbon atoms, and R ¹ and R ² are different from each other, any one of them may be a hydrogen atom, a fluorine atom, a methyl group, or a methyl halide group, Furthermore, R ¹ and R ² may combine to form a ring), or —C (CH ₃ ) ₂ —, —C (CF ₃ ) ₂ —, —CO -, - COO -, - CONH -, - (CF 2) p - (p is an integer of 1 to 10), - _SO 2 -,

A second group or a direct bond which is one group selected from the group consisting of: a sulfonated product of the polyarylene copolymer, wherein the first group and the second group as A in the molecule or The membrane-electrode structure for a polymer electrolyte fuel cell according to claim 1, comprising both a direct bond and a direct bond. A solid polymer electrolyte membrane comprising a sulfonated polyarylene copolymer comprising a first repeating unit represented by the following general formula (1) and a second repeating unit represented by the following general formula (2) A polymer electrolyte fuel cell comprising a membrane-electrode structure for a polymer electrolyte fuel cell sandwiched between a pair of electrodes containing a catalyst.

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