WO2012026623A1 - Polymer electrolyte composition and polymer electrolyte membrane - Google Patents

Polymer electrolyte composition and polymer electrolyte membrane Download PDF

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Publication number
WO2012026623A1
WO2012026623A1 PCT/JP2011/069972 JP2011069972W WO2012026623A1 WO 2012026623 A1 WO2012026623 A1 WO 2012026623A1 JP 2011069972 W JP2011069972 W JP 2011069972W WO 2012026623 A1 WO2012026623 A1 WO 2012026623A1
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group
carbon atoms
substituent
polymer electrolyte
sulfur
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PCT/JP2011/069972
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French (fr)
Japanese (ja)
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武 石山
中村　大輔
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住友化学株式会社
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Publication of WO2012026623A1 publication Critical patent/WO2012026623A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
    • H01B1/06—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors mainly consisting of other non-metallic substances
    • H01B1/12—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors mainly consisting of other non-metallic substances organic substances
    • H01B1/122—Ionic conductors
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
    • C08J5/20—Manufacture of shaped structures of ion-exchange resins
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
    • C08J5/20—Manufacture of shaped structures of ion-exchange resins
    • C08J5/22—Films, membranes or diaphragms
    • C08J5/2206—Films, membranes or diaphragms based on organic and/or inorganic macromolecular compounds
    • C08J5/2218—Synthetic macromolecular compounds
    • C08J5/2256—Synthetic macromolecular compounds based on macromolecular compounds obtained by reactions other than those involving carbon-to-carbon bonds, e.g. obtained by polycondensation
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/10—Fuel cells with solid electrolytes
    • H01M8/1016—Fuel cells with solid electrolytes characterised by the electrolyte material
    • H01M8/1018—Polymeric electrolyte materials
    • H01M8/102—Polymeric electrolyte materials characterised by the chemical structure of the main chain of the ion-conducting polymer
    • H01M8/1027—Polymeric electrolyte materials characterised by the chemical structure of the main chain of the ion-conducting polymer having carbon, oxygen and other atoms, e.g. sulfonated polyethersulfones [S-PES]
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/10—Fuel cells with solid electrolytes
    • H01M8/1016—Fuel cells with solid electrolytes characterised by the electrolyte material
    • H01M8/1018—Polymeric electrolyte materials
    • H01M8/102—Polymeric electrolyte materials characterised by the chemical structure of the main chain of the ion-conducting polymer
    • H01M8/1032—Polymeric electrolyte materials characterised by the chemical structure of the main chain of the ion-conducting polymer having sulfur, e.g. sulfonated-polyethersulfones [S-PES]
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/10—Fuel cells with solid electrolytes
    • H01M8/1016—Fuel cells with solid electrolytes characterised by the electrolyte material
    • H01M8/1018—Polymeric electrolyte materials
    • H01M8/102—Polymeric electrolyte materials characterised by the chemical structure of the main chain of the ion-conducting polymer
    • H01M8/1037—Polymeric electrolyte materials characterised by the chemical structure of the main chain of the ion-conducting polymer having silicon, e.g. sulfonated crosslinked polydimethylsiloxanes
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2365/00—Characterised by the use of macromolecular compounds obtained by reactions forming a carbon-to-carbon link in the main chain; Derivatives of such polymers
    • C08J2365/02—Polyphenylenes
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/30—Hydrogen technology
    • Y02E60/50—Fuel cells

Definitions

  • the present invention relates to a polymer electrolyte composition and a polymer electrolyte membrane.
  • a polymer electrolyte fuel cell (hereinafter sometimes abbreviated as “fuel cell”) is a power generation device that utilizes an electrochemical reaction between hydrogen and oxygen, and is used as a polymer electrolyte membrane used in a fuel cell. Fluorine polymer electrolyte membranes and hydrocarbon polymer electrolyte membranes have attracted attention.
  • a fuel cell using a fluorine-based polymer electrolyte membrane or a hydrocarbon-based polymer electrolyte membrane does not necessarily have sufficient operation stability (hereinafter referred to as “long-term stability”) when operated for a long time. Has been pointed out.
  • 2003-201403 discloses a sulfonated polymer, 1,3,5-trimethyl-2,4,6-tris (3,5- And a polyelectrolyte composition comprising an antioxidant comprising di-t-butyl-4-hydroxybenzyl) benzene and bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite.
  • a polymer electrolyte membrane is described.
  • the antioxidant described above has low dispersibility and compatibility with non-aliphatic hydrocarbon polymer electrolytes, and the durability of the antioxidant itself is also low.
  • the ion conductivity is likely to be lowered due to the deterioration of the polymer electrolyte membrane due to radicals.
  • the power generation performance of the fuel cell itself is likely to deteriorate.
  • An object of the present invention is to provide a polymer electrolyte composition from which a polymer electrolyte membrane realizing a fuel cell with good long-term stability is obtained, a fuel cell member using the polymer electrolyte composition, and a solid excellent in long-term stability
  • the object is to provide a polymer fuel cell.
  • the present invention provides the following [1] to [11].
  • [1] A polymer electrolyte composition comprising one or more sulfur-containing aromatic compounds selected from the group consisting of the following sulfur-containing aromatic compounds [A] to [D] and a polymer electrolyte.
  • Sulfur-containing aromatic compound [A] A sulfur-containing aromatic compound represented by the following formula (1). (In Formula (1), Y 1 represents a divalent group containing a sulfur atom.
  • C 1 to C 4 each represents a carbon atom.
  • Ring Ar 01 contains C 1 and C 2 and has a substituent.
  • the substituent that 01 may have and the substituent which Ar 02 may have are a hydroxyl group, a halogeno group, a cyano group, a carboxy group, a phosphono group, a sulfo group, a formyl group, a mercapto group, and a methyl group, respectively.
  • An aryloxy group having 4 to 20 carbon atoms, an arylthio group having 4 to 20 carbon atoms which may have a substituent, an aroyl group having 5 to 21 carbon atoms which may have a substituent, or a substituent Represents an arylsulfonyl group having 4 to 20 carbon atoms which may have Sulfur-containing aromatic compound [B]:
  • Y 1 has the same meaning as above.
  • Z 1 represents a direct bond or a divalent group represented by any of the following formulas (2-1) to (2-9).
  • ring Ar 03 represents an aromatic ring having 4 to 50 carbon atoms which may have a substituent, including C 5 and C 6.
  • Ring Ar 04 represents C It represents an aromatic ring having 4 to 50 carbon atoms which contains 7 and C 8 and may have a substituent.
  • E 1 represents a hydrogen atom, a hydroxyl group, a methyl group, a methoxy group, or an aromatic group having 4 to 50 carbon atoms.
  • Sulfur-containing aromatic compound [C] Sulfur-containing aromatic compound represented by the following formula (3).
  • Y 1 and Z 1 have the same meanings as above.
  • C 9 to C 12 each represent a carbon atom.
  • X 3 to X 6 are the same or different, and each represents a hydrogen atom, a hydroxyl group, A halogeno group, a cyano group, a carboxy group, a phosphono group, a sulfo group, a formyl group, a mercapto group, an optionally substituted alkyl group having 1 to 20 carbon atoms, and an optionally substituted carbon number
  • Y 1 and Z 1 are as defined above.
  • C 13 to C 16 each represent a carbon atom.
  • Ring Ar 05 contains C 15 and C 16 and has a substituent.
  • X 7 and X 8 are the same or different and each represents a hydrogen atom, a hydroxyl group, a halogeno group, a cyano group, a carboxy group, a phosphono group, a sulfo group, a formyl group, A mercapto group, an optionally substituted alkyl group having 1 to 20 carbon atoms, an optionally substituted alkoxy group having 1 to 20 carbon atoms, and an optionally substituted carbon number
  • the sulfur-containing aromatic compound contained in the polymer electrolyte composition is one or more sulfur-containing aromatic compounds selected from the group consisting of sulfur-containing aromatic compounds [B] to [D].
  • R 01 to R 08 are the same or different, and each represents a hydrogen atom, a hydroxyl group, a halogeno group, a cyano group, a carboxy group, a phosphono group, A sulfo group, a formyl group, a mercapto group, an optionally substituted alkyl group having 1 to 20 carbon atoms, an optionally substituted alkoxy group having 1 to 20 carbon atoms, and a substituent.
  • polymer electrolyte composition as described in any one of [1] to [5], wherein the polymer electrolyte is a fluorine-based polymer electrolyte.
  • a polymer electrolyte membrane comprising the polymer electrolyte composition according to any one of [1] to [7].
  • a catalyst composition comprising the polymer electrolyte composition according to any one of [1] to [7] and a catalyst component.
  • a membrane / electrode assembly comprising at least one selected from the group consisting of the polymer electrolyte membrane according to [8] and the catalyst composition according to [9].
  • a polymer electrolyte fuel cell comprising the membrane electrode assembly according to [10].
  • the electrolyte composition of the present invention contains one or more sulfur-containing aromatic compounds selected from the group consisting of the following sulfur-containing aromatic compounds [A] to [D] and a polymer electrolyte.
  • sulfur-containing aromatic compound [A] A sulfur-containing aromatic compound represented by the following formula (1).
  • Y 1 Represents a divalent group containing a sulfur atom.
  • C 1 ⁇ C 4 Each represents a carbon atom.
  • Ring Ar 01 Is C 1 And C 2 And an aromatic ring having 4 to 50 carbon atoms which may have a substituent.
  • Ring Ar 02 Is C 3 And C 4 And an aromatic ring having 4 to 50 carbon atoms which may have a substituent.
  • Ar 01 May have a substituent and Ar 02 Each may have a hydroxyl group, halogeno group, cyano group, carboxy group, phosphono group, sulfo group, formyl group, mercapto group, methyl group, or optionally substituted carbon number 4
  • X 1 And X 2 are the same or different and each has a hydrogen atom, hydroxyl group, halogeno group, cyano group, carboxy group, phosphono group, sulfo group, formyl group, mercapto group, methyl group, or optionally substituted carbon atoms of 4 to 20 aryl groups, optionally substituted aryloxy groups having 4 to 20 carbon atoms, optionally substituted arylthio groups having 4 to 20 carbon atoms, optionally having substituents It represents a good aroyl group having 5 to 21 carbon atoms or an arylsulfonyl group having 4 to 20 carbon atoms which may have a substituent.
  • Y 1 Represents a divalent group containing a sulfur atom.
  • Y 1 are preferably a divalent group containing a divalent or tetravalent sulfur atom, more preferably a sulfur atom (a group represented by -S-) or a sulfinyl group (a group represented by -SO-). More preferred is a sulfur atom.
  • C 1 ⁇ C 4 Represents a carbon atom.
  • C 1 -C 2 Bond and C 3 -C 4 Each bond is a carbon-carbon bond in an aromatic ring.
  • Ring Ar 01 Is C 1 And C 2 And an aromatic ring having 4 to 50 carbon atoms which may have a substituent.
  • Ring Ar 02 Is C 3 And C 4 And an aromatic ring having 4 to 50 carbon atoms which may have a substituent.
  • the aromatic ring preferably has 4 to 30 carbon atoms, more preferably 4 to 25 carbon atoms, and particularly preferably 6 to 20 carbon atoms.
  • Examples of the aromatic ring having 4 to 50 carbon atoms include monocyclic aromatic rings such as benzene, diphenyl ether, diphenyl sulfide, benzophenone, biphenyl, biphenylene, indacene, acenaphthylene, fluorene, phenalene, phenanthrene, anthracene, fluoranthene, triphenylene, and pyrene.
  • Condensed ring aromatic rings such as naphthacene and perylene, and aromatic rings containing heteroatoms such as furan, benzofuran and dibenzofuran in the ring.
  • the aromatic ring having 4 to 50 carbon atoms may have a substituent, which includes a hydroxyl group, a halogeno group, a cyano group, a carboxy group, a phosphono group, a sulfo group, a formyl group, a mercapto group, a methyl group,
  • the substituent on the aromatic ring having 4 to 50 carbon atoms is preferably a halogeno group, a cyano group, a carboxy group, a phosphono group, a sulfo group, a formyl group, a mercapto group, or an optionally substituted carbon number of 4
  • Good arylthio having 4 to 20 carbon atoms A group selected from an aroyl group having 5 to 21 carbon atoms which may have a substituent, and an arylsulfonyl group having 4 to 20 carbon atoms which may have a substituent, and more preferably a cyano group A group, a carboxy group, an aryl group having 4 to 20 carbon atoms which may have a substituent, an aryloxy group having 4 to 20 carbon atoms which may have a substituent, and a substituent.
  • the aryl group having 4 to 20 carbon atoms which may have a substituent the arylthio group having 4 to 20 carbon atoms which may have a substituent, and a substituent. It may have an aroyl group having 5 to 21 carbon atoms or a substituent.
  • X above 1 And X 2 Each independently represents a hydrogen atom, a hydroxyl group, a halogeno group, a cyano group, a carboxy group, a phosphono group, a sulfo group, a formyl group, a mercapto group, a methyl group, or an aryl group having 4 to 20 carbon atoms, which may have a substituent.
  • an aryloxy group having 4 to 20 carbon atoms which may have a substituent an arylthio group having 4 to 20 carbon atoms which may have a substituent, and a carbon number which may have a substituent
  • it has a hydrogen atom, a halogeno group, a cyano group, a carboxy group, a phosphono group, a sulfo group, a formyl group, a mercapto group, an optionally substituted aryl group having 4 to 20 carbon atoms, or a substituent.
  • An aryl group having 4 to 20 carbon atoms, an aryloxy group having 4 to 20 carbon atoms which may have a substituent, an arylthio group having 4 to 20 carbon atoms which may have a substituent, and a substituent May have 5 to 2 carbon atoms
  • the halogeno group include a fluoro group, a chloro group, a bromo group, and an iodo group, and a fluoro group is preferable.
  • aryl group having 4 to 20 carbon atoms which may have the above substituent include phenyl, o-methylphenyl, m-methylphenyl, p-methylphenyl, o-phenoxyphenyl, m-phenoxyphenyl, p- Monocyclic aryl groups such as phenoxyphenyl, o-chlorophenyl, m-chlorophenyl, p-chlorophenyl and biphenyl, and condensed ring aryls such as 1-naphthyl, 2-naphthyl, 1-anthracyl, 2-anthracyl and 4-anthracyl groups Groups, heteroaryl groups such as 2-thienyl, 3-thienyl, 2-furyl, 3-furyl and the like.
  • aryloxy group having 4 to 20 carbon atoms which may have the above-mentioned substituent an aryl group selected from the exemplified group of aryl groups having 4 to 20 carbon atoms which may have the aforementioned substituent And a group in which a hydrogen atom of a hydroxyl group is substituted.
  • arylthio group having 4 to 20 carbon atoms which may have the above-mentioned substituent an aryl group selected from the exemplified group of aryl groups having 4 to 20 carbon atoms which may have the aforementioned substituent And a group in which a hydrogen atom of a mercapto group is substituted.
  • aroyl group having 5 to 21 carbon atoms which may have a substituent an aryl group selected from the above-mentioned exemplified group of aryl groups having 4 to 20 carbon atoms which may have a substituent And a group in which a hydrogen atom of the formyl group is substituted.
  • arylsulfonyl group having 4 to 20 carbon atoms which may have the above substituent include phenylsulfonyl, o-methylphenylsulfonyl, m-methylphenylsulfonyl, p-methylphenylsulfonyl, o-phenoxyphenylsulfonyl, m -Monocyclic arylsulfonyl groups such as -phenoxyphenylsulfonyl, p-phenoxyphenylsulfonyl, o-chlorophenylsulfonyl, m-chlorophenylsulfonyl, p-chlorophenylsulfonyl, 1-naphthylsulfonyl, 2-naphthylsulfonyl, 1-anthracylsulfonyl, Examples thereof include condensed ring arylsulfonyl groups
  • sulfur-containing aromatic compound [A] represented by the above formula (1) examples include phenyl sulfide, bis (2-hydroxy-5-chlorophenyl) sulfide, 4-benzoyl 4′-methyldiphenyl sulfide, bis (4 -Hydroxy-3-methylphenyl) sulfide, bis (4-methacryloylthiophenyl) sulfide, bis (4-hydroxyphenyl) sulfide, phenyl p-tolyl sulfide, 5,5'-thiodisalicylic acid, 2,2'-thiobis (4,6-dichlorophenol) disodium, 2,2′-thiobis (4,6-dichlorophenol), 4,4′-thiobisbenzenethiol 4-chlorophenyl sulfoxide, diphenyl sulfoxide, p-tolyl sulfoxide, 1, 1′-thiobis (2-naphthol), 1,
  • Sulfur-containing aromatic compound [B] A sulfur-containing aromatic compound represented by the following formula (2).
  • Y 1 Is as defined above.
  • Z 1 Represents a direct bond or a divalent group represented by any of the following formulas (2-1) to (2-9).
  • C 5 ⁇ C 8 Each represents a carbon atom.
  • Ring Ar 03 Is C 5 And C 6 And an aromatic ring having 4 to 50 carbon atoms which may have a substituent.
  • Ring Ar 04 Is C 7 And C 8 And an aromatic ring having 4 to 50 carbon atoms which may have a substituent.
  • E 1 Represents a hydrogen atom, a hydroxyl group, a methyl group, a methoxy group or an aromatic group having 4 to 50 carbon atoms.
  • Y 1 Is Y in formula (1) 1 And preferred examples thereof are also Y in formula (1). 1 These are the same as the specific examples and preferred examples.
  • C 5 ⁇ C 8 Represents a carbon atom.
  • C 5 -C 8 Bond and C 7 -C 8 Each bond is a carbon-carbon bond in an aromatic ring group.
  • Ring Ar 03 Is C 5 And C 6 And an aromatic ring having 4 to 50 carbon atoms which may have a substituent.
  • Ring Ar 04 Is C 7 And C 8 And an aromatic ring having 4 to 50 carbon atoms which may have a substituent.
  • the aromatic ring preferably has 4 to 30 carbon atoms, more preferably 4 to 25 carbon atoms, and particularly preferably 6 to 20 carbon atoms.
  • Examples of the aromatic ring having 4 to 50 carbon atoms include monocyclic aromatic rings such as benzene, diphenyl ether, diphenyl sulfide, benzophenone, and biphenyl, biphenylene, indacene, acenaphthylene, fluorene, phenalene, phenanthrene, anthracene, fluoranthene, triphenylene, and pyrene.
  • Condensed ring aromatic rings such as naphthacene and perylene, and aromatic rings including heteroatoms such as furan, benzofuran, dibenzofuran, thiophene, benzothiophene, and dibenzothiophene.
  • the aromatic ring having 4 to 50 carbon atoms may have a substituent.
  • substituents examples include a hydroxyl group, a halogeno group, a cyano group, a carboxy group, a phosphono group, a sulfo group, a formyl group, a mercapto group, An optionally substituted alkyl group having 1 to 20 carbon atoms, an optionally substituted alkoxy group having 1 to 20 carbon atoms, and an optionally substituted carbon group having 1 to 20 carbon atoms.
  • an arylsulfonyl group having 3 to 20 carbon atoms and a substituent and a group selected from alkylsulfonyl groups having 1 to 20 carbon atoms.
  • the substituent on the aromatic ring having 4 to 50 carbon atoms is preferably used here.
  • An arylsulfonyl group having 3 to 20 carbon atoms which may be present, more preferably a cyano group, a carboxy group, a formyl group, an aryl group having 3 to 20 carbon atoms which may have a substituent, or a substituent.
  • a reeloxy group an optionally substituted arylthio group having 3 to 20 carbon atoms, an optionally substituted aroyl group having 4 to 21 carbon atoms, and an optionally substituted carbon
  • an arylsulfonyl group having 3 to 20 carbon atoms, particularly preferably an aryl group having 3 to 20 carbon atoms which may have a substituent and an aryl having 3 to 20 carbon atoms which may have a substituent.
  • the halogeno group include a fluoro group, a chloro group, a bromo group, and an iodo group, and preferably a fluoro group.
  • Examples of the alkyl group having 1 to 20 carbon atoms that may have a substituent include a linear or branched alkyl group. The number of carbon atoms is preferably 1 to 6, more preferably 1 to 4, still more preferably 1 to 4, and particularly preferably 1.
  • alkoxy group having 1 to 20 carbon atoms which may have the above-mentioned substituent an alkyl group selected from the above-mentioned exemplary group of alkyl groups having 1 to 20 carbon atoms which may have a substituent And a group in which a hydrogen atom of a hydroxyl group is substituted.
  • Preferred examples thereof include a group in which a hydrogen atom of a hydroxyl group is substituted with an alkyl group selected from the above-mentioned preferred examples of the alkyl group.
  • an alkyl group selected from the exemplified group of alkyl groups having 1 to 20 carbon atoms which may have the aforementioned substituent And a group in which a hydrogen atom of a mercapto group is substituted.
  • Preferred examples thereof include a group in which a hydrogen atom of a mercapto group is substituted with an alkyl group selected from the above-mentioned preferred examples of the alkyl group.
  • aryl group having 3 to 20 carbon atoms which may have the above substituent include phenyl, o-methylphenyl, m-methylphenyl, p-methylphenyl, o-methoxyphenyl, m-methoxyphenyl, p- Monocyclic aryl groups such as methoxyphenyl, o-phenoxyphenyl, m-phenoxyphenyl, p-phenoxyphenyl, o-chlorophenyl, m-chlorophenyl, p-chlorophenyl, biphenyl, 1-naphthyl, 2-naphthyl, 1- Examples thereof include condensed aryl groups such as anthracyl, 2-anthracyl and 4-anthracyl groups, and heteroaryl groups such as 2-thienyl, 3-thienyl, 2-furyl and 3-furyl groups.
  • aryloxy group having 3 to 20 carbon atoms which may have the above-mentioned substituent
  • a group in which a hydrogen atom of a hydroxyl group is substituted Preferred examples thereof include a group in which a hydrogen atom of a hydroxyl group is substituted with an aryl group selected from the above-mentioned preferred examples of the aryl group.
  • arylthio group having 3 to 20 carbon atoms which may have the above-described substituent
  • a group in which a hydrogen atom of a mercapto group is substituted Preferred examples thereof include a group in which a hydrogen atom of a mercapto group is substituted with an aryl group selected from the above-mentioned preferred examples of the aryl group.
  • the acyl group having 2 to 21 carbon atoms which may have the above-mentioned substituent is an alkyl group selected from the above-mentioned exemplified group of alkyl groups having 1 to 20 carbon atoms which may have a substituent.
  • Examples include groups in which a hydrogen atom of a formyl group is substituted.
  • Preferable examples thereof include a group in which a hydrogen atom of a formyl group is substituted with an alkyl group selected from the above-mentioned preferred examples of the alkyl group.
  • an aryl group having 4 to 21 carbon atoms which may have the above-described substituent an aryl group selected from the exemplified group of aryl groups having 3 to 20 carbon atoms which may have the aforementioned substituent
  • a group in which a hydrogen atom of the formyl group is substituted Preferred examples thereof include a group in which a hydrogen atom of the formyl group is substituted with an aryl group selected from the above-mentioned preferred examples of the aryl group.
  • arylsulfonyl group having 3 to 20 carbon atoms which may have the above substituent include phenylsulfonyl, o-methylphenylsulfonyl, m-methylphenylsulfonyl, p-methylphenylsulfonyl, o-methoxyphenylsulfonyl, m -Methoxyphenylsulfonyl, p-methoxyphenylsulfonyl, o-phenoxyphenylsulfonyl, m-phenoxyphenylsulfonyl, p-phenoxyphenylsulfonyl, o-chlorophenylsulfonyl, m-chlorophenylsulfonyl, p-chlorophenylsulfonyl, biphenylsulfonyl group, etc.
  • cyclic arylsulfonyl group Condensation of cyclic arylsulfonyl group, 1-naphthylsulfonyl, 2-naphthylsulfonyl, 1-anthracylsulfonyl, 2-anthracylsulfonyl, 4-anthracylsulfonyl group, etc.
  • heteroarylsulfonyl groups such as a ring arylsulfonyl group, 2-thienylsulfonyl, 3-thienylsulfonyl, 2-furylsulfonyl, and 3-furylsulfonyl group.
  • the preferable carbon number is 1 to 6, more preferably 1 to 4, and still more preferably 1 to 4. Yes, particularly preferably 1.
  • Specific examples include methylsulfonyl, ethylsulfonyl, propylsulfonyl, isopropylsulfonyl, butylsulfonyl, isobutylsulfonyl, sec-butylsulfonyl, t-butylsulfonyl, pentylsulfonyl, hexylsulfonyl, heptylsulfonyl, octylsulfonyl, decylsulfonyl groups, and the like.
  • Z 1 Represents a direct bond or a divalent group represented by any one of formulas (2-1) to (2-9). Preferred are direct bonds, (2-1) to (2-3), and (2-7) to (2-9), and more preferred are direct bonds, (2-2), (2-3), ( 2-7) and (2-8), particularly preferably a direct bond, (2-2), (2-3) and (2-7).
  • E 1 Represents a hydrogen atom, a hydroxyl group, a methyl group, a methoxy group or an aromatic group having 4 to 50 carbon atoms which may have a substituent, preferably a monovalent group having 4 to 50 carbon atoms which may have a substituent. Is an aromatic group.
  • the number of carbon atoms of the aromatic group is preferably 4-30, more preferably 4-20, and particularly preferably 4-12.
  • E 1 Examples of the aromatic group having 4 to 50 carbon atoms are benzene, toluene, methoxybenzene, biphenyl, naphthalene, anthracene, fluorene, furan, benzofuran, dibenzofuran, thiophene, benzothiophene, dibenzothiophene, thianthrene, phenoxathiin, etc.
  • An aromatic group derived from the aromatic compound of 1 The monovalent aromatic group having 4 to 50 carbon atoms represented by benzene, toluene, methoxybenzene, biphenyl, naphthalene, anthracene, fluorene, furan, benzofuran, dibenzofuran, thiophene, benzothiophene, dibenzothiophene, thianthrene, phenoxy
  • a group obtained by removing one hydrogen atom on an aromatic ring from satiin can be mentioned.
  • the monovalent aromatic group having 4 to 50 carbon atoms may have a substituent, and includes a hydroxyl group, a halogeno group, a cyano group, a carboxy group, a phosphono group, a sulfo group, a formyl group, a mercapto group, and a substituent.
  • An optionally substituted alkyl group having 1 to 20 carbon atoms, an optionally substituted alkoxy group having 1 to 20 carbon atoms, and an optionally substituted alkylthio group having 1 to 20 carbon atoms An aryl group having 3 to 20 carbon atoms which may have a substituent, an aryloxy group having 3 to 20 carbon atoms which may have a substituent, and 3 carbon atoms which may have a substituent
  • aryloxy group having 3 to 20 carbon atoms an arylthio group having 3 to 20 carbon atoms which may have a substituent, an aroyl group having 4 to 21 carbon atoms which may have a substituent, and a substituent.
  • An arylsulfonyl group having 3 to 20 carbon atoms which may be substituted, more preferably a cyano group, a carboxy group, a formyl group, an aryl group having 3 to 20 carbon atoms which may have a substituent, or a substituted group.
  • an arylthio group having 3 to 20 carbon atoms which may have a substituent an arylthio group having 3 to 20 carbon atoms which may have a substituent, an aroyl group having 4 to 21 carbon atoms which may have a substituent, and 3 carbon atoms which may have a substituent ⁇ 20 arylsulfonyl groups.
  • a halogeno group an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxy group having 1 to 20 carbon atoms which may have a substituent, or a substituent.
  • Specific examples and preferred examples of the group selected from an arylsulfonyl group having 3 to 20 carbon atoms which may have a substituent and an alkylsulfonyl group having 1 to 20 carbon atoms which may have a substituent Is the ring Ar 03 Or ring Ar 04 And the same substituents as those on the aromatic ring having 4 to 50 carbon atoms.
  • sulfur-containing aromatic compound [B] represented by the above formula (2) include compounds represented by the following (B-001) to (B-018).
  • sulfur-containing aromatic compound [C] will be described.
  • X 3 ⁇ X 6 are the same or different and each is a hydrogen atom, a hydroxyl group, a halogeno group, a cyano group, a carboxy group, a phosphono group, a sulfo group, a formyl group, a mercapto group, or an alkyl having 1 to 20 carbon atoms which may have a substituent.
  • Z 1 X is a direct bond, X 4 And X 5 Are bonded to each other, so that C 10 And C 11 A ring containing may be formed.
  • Y 1 And Z 1 Is Y in formula (1) 1 And Z in formula (2) 1 Specific examples and preferred examples thereof are also Y in the formula (1). 1 And Z in formula (2) 1 Specific examples and preferred examples of these can be mentioned.
  • C 9 ⁇ C 12 Represents a carbon atom.
  • C 9 -C 10 Bond and C 11 -C 12 The bond is a double bond.
  • X 3 ⁇ X 6 are the same or different and each is a hydrogen atom, a hydroxyl group, a halogeno group, a cyano group, a carboxy group, a phosphono group, a sulfo group, a formyl group, a mercapto group, or an alkyl having 1 to 20 carbon atoms which may have a substituent.
  • X 3 ⁇ X 6 are preferably a hydrogen atom, a hydroxyl group, a halogeno group, a cyano group, a carboxy group, a phosphono group, a sulfo group, a formyl group, a mercapto group, an optionally substituted aryl group having 3 to 20 carbon atoms, An aryloxy group having 3 to 20 carbon atoms which may have a substituent, an arylthio group having 3 to 20 carbon atoms which may have a substituent, and 4 to 4 carbon atoms which may have a substituent 21 an aroyl group, an arylsulfonyl group having 3 to 20 carbon atoms which may have a substituent, and more preferably a hydrogen atom, a cyano group, a carboxy group, a formyl group, or a substituent.
  • a halogeno group an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxy group having 1 to 20 carbon atoms which may have a substituent, or a substituent.
  • An optionally substituted arylthio group having 3 to 20 carbon atoms, an optionally substituted acyl group having 2 to 21 carbon atoms, and an optionally substituted aroyl group having 4 to 21 carbon atoms Specific examples and preferred examples of the group selected from an arylsulfonyl group having 3 to 20 carbon atoms which may have a substituent and an alkylsulfonyl group having 1 to 20 carbon atoms which may have a substituent Is the ring Ar 03 Or ring Ar
  • Z 1 X is a direct bond, X 4 And X 5 May bond to each other to form a ring.
  • the ring C 10 And C 11 And a ring having 4 to 50 carbon atoms which may have a substituent is preferable, and the ring preferably has aromaticity. More preferable examples include a ring having 6 to 20 carbon atoms which may have a substituent, and particularly preferable examples include a ring having 6 to 12 carbon atoms which may have a substituent.
  • the aromaticity here means 4n + 2 (n represents an arbitrary integer) in the ring of the cyclic group as described in Morrison Void Organic Chemistry (Middle) 6th Edition (Tokyo Kagaku Dojin). It includes ⁇ electrons.
  • the groups represented by the following formulas (501-1) to (501-4) may be exemplified as the cyclic group. it can.
  • the substituent on the cyclic group include a hydroxyl group, a halogeno group, a cyano group, a carboxy group, a phosphono group, a sulfo group, a formyl group, a mercapto group, and an optionally substituted alkyl group having 1 to 20 carbon atoms.
  • Specific examples and preferred examples thereof are the above Ar.
  • 03 Or Ar 04 Specific examples of the group that may be possessed by the aromatic ring having 4 to 50 carbon atoms and preferred examples thereof, and the like, can be given.
  • Specific examples of the sulfur-containing aromatic compound [C] represented by the above formula (3) include the following (C-001) to (C-021). Next, the sulfur-containing aromatic compound [D] will be described.
  • Ring Ar 05 Is C 15 And C 16 And an aromatic ring having 4 to 50 carbon atoms which may have a substituent.
  • X 7 And X 8 are the same or different and each is a hydrogen atom, a hydroxyl group, a halogeno group, a cyano group, a carboxy group, a phosphono group, a sulfo group, a formyl group, a mercapto group, or an alkyl having 1 to 20 carbon atoms which may have a substituent.
  • Y 1 And Z 1 Is Y in formula (1) 1 And Z in formula (2) 1 Specific examples and preferred examples thereof are also Y in the formula (1). 1 And Z in formula (2) 1 Specific examples and preferred examples of these can be mentioned.
  • C 13 ⁇ C 16 Represents a carbon atom.
  • C 13 -C 14 The bond is a double bond.
  • C 15 -C 16 The bond is a carbon-carbon bond in the aromatic ring group.
  • Ring Ar 05 Is C 15 And C 16 And an aromatic ring having 4 to 50 carbon atoms which may have a substituent.
  • Ring Ar 05 Specific examples and preferred examples thereof are the above-mentioned ring Ar 03 Or ring Ar 04 The same thing as the example of can be mentioned.
  • the aromatic ring having 4 to 50 carbon atoms may have a substituent.
  • substituents include a hydroxyl group, a halogeno group, a cyano group, a carboxy group, a phosphono group, a sulfo group, a formyl group, a mercapto group, An optionally substituted alkyl group having 1 to 20 carbon atoms, an optionally substituted alkoxy group having 1 to 20 carbon atoms, and an optionally substituted carbon group having 1 to 20 carbon atoms.
  • an arylsulfonyl group having 3 to 20 carbon atoms and a substituent and a group selected from alkylsulfonyl groups having 1 to 20 carbon atoms.
  • Specific examples and preferred examples thereof include the ring Ar 03 Or ring Ar 04
  • the same groups as those described above as the group that the aromatic ring having 4 to 50 carbon atoms may have can be exemplified.
  • X 7 And X 8 are the same or different and each is a hydrogen atom, a hydroxyl group, a halogeno group, a cyano group, a carboxy group, a phosphono group, a sulfo group, a formyl group, a mercapto group, or an alkyl having 1 to 20 carbon atoms which may have a substituent.
  • X 7 And X 8 Specific examples and preferred examples thereof are the above X 3 ⁇ X 6 The same thing can be given.
  • sulfur-containing aromatic compound [D] represented by the above formula (4) include the following (D-001) to (D-006).
  • sulfur-containing aromatic compounds [A] to [D] sulfur-containing aromatic compounds [B] to [D] are preferable, and sulfur-containing aromatic compounds [B] and [D] are more preferable.
  • Particularly preferred is a sulfur-containing aromatic compound [B].
  • a preferred sulfur-containing aromatic compound [B] is a sulfur-containing aromatic compound represented by the following formula (6). (In formula (6), Y 1 And Z 1 Is as defined above.
  • R 01 ⁇ R 08 are the same or different and each is a hydrogen atom, a hydroxyl group, a halogeno group, a cyano group, a carboxy group, a phosphono group, a sulfo group, a formyl group, a mercapto group, or an alkyl having 1 to 20 carbon atoms which may have a substituent.
  • Y 1 And Z 1 Is Y in formula (1) 1 And Z in formula (2) 1 Specific examples and preferred examples thereof are also Y in the formula (1). 1 And Z in formula (2) 1 Specific examples and preferred examples of these can be mentioned.
  • R 01 ⁇ R 08 Are the same or different and each is a hydrogen atom, a hydroxyl group, a halogeno group, a cyano group, a carboxy group, a phosphono group, a sulfo group, a formyl group, a mercapto group, or an alkyl having 1 to 20 carbon atoms which may have a substituent.
  • R 01 ⁇ R 08 Is preferably a hydrogen atom, a hydroxyl group, a halogeno group, a cyano group, a carboxy group, a phosphono group, a sulfo group, a formyl group, a mercapto group, an optionally substituted aryl group having 3 to 20 carbon atoms, a substituted group An aryloxy group having 3 to 20 carbon atoms which may have a group, an arylthio group having 3 to 20 carbon atoms which may have a substituent, and 4 to 21 carbon atoms which may have a substituent An aroyl group, an arylsulfonyl group having 3 to 20 carbon atoms which may have a substituent, and more preferably a hydrogen atom, a cyano group, a carboxy group, a formyl group, or a substituent.
  • aryl group having 3 to 20 carbon atoms it has an aryl group having 3 to 20 carbon atoms, an aryloxy group having 3 to 20 carbon atoms which may have a substituent, an arylthio group having 3 to 20 carbon atoms which may have a substituent, and a substituent.
  • Alloys with 4 to 21 carbon atoms that may be Group, an optionally substituted arylsulfonyl group having 3 to 20 carbon atoms, particularly preferably a hydrogen atom, an optionally substituted aryl group having 3 to 20 carbon atoms, or a substituent.
  • An aryloxy group having 3 to 20 carbon atoms which may have a substituent an arylthio group having 3 to 20 carbon atoms which may have a substituent, and an aryloxy group having 4 to 21 carbon atoms which may have a substituent.
  • it has a halogeno group, an optionally substituted alkyl group having 1 to 20 carbon atoms, an optionally substituted alkoxy group having 1 to 20 carbon atoms, and a substituent.
  • the polymer electrolyte composition of the present invention can be prepared by blending the sulfur-containing aromatic compound and the polymer electrolyte.
  • the blending amount is selected within a range that does not significantly impair characteristics such as ion conductivity of the polymer electrolyte.
  • the sulfur-containing aromatic compound is 0.01 to 30 parts by weight, more preferably 0.1 to 20 parts by weight, and more preferably 0.5 to 10 parts by weight with respect to 100 parts by weight of the polymer electrolyte. Is more preferable.
  • the molecular weight of the sulfur-containing aromatic compound used in the present invention is preferably from 80 to 1300, more preferably from 160 to 1300, from the viewpoint of solubility or dispersibility in the solution during the preparation of the polymer electrolyte composition. 170 to 1000 is even more preferable, and 200 to 800 is particularly preferable. A sulfur-containing aromatic compound having a molecular weight in such a range is preferable because it has high solubility or dispersibility in a solution during the preparation of the polymer electrolyte composition.
  • requiring the molecular weight of a sulfur-containing aromatic compound by analysis this number average molecular weight measured by a gel permeation chromatography (GPC) method can be used. The GPC measurement conditions are shown below.
  • polymer electrolyte contained in the polymer electrolyte composition of the present invention
  • examples of the polymer electrolyte include fluorine-based polymer electrolytes having ion exchange groups such as Nafion (registered trademark of DuPont), Aciplex (Asahi Kasei registered trademark) manufactured by Asahi Kasei, and Flemion (Asahi Glass registered trademark) manufactured by Asahi Glass, and aliphatic.
  • a hydrocarbon polymer electrolyte into which an ion exchange group such as a phenolic hydroxyl group is introduced is used. Since there is a concern that the hydrocarbon polymer electrolyte has low radical resistance, the polymer electrolyte contained in the polymer electrolyte composition of the present invention is a hydrocarbon polymer electrolyte. The effect of obtaining a polymer electrolyte membrane having radical resistance can be better enjoyed.
  • the hydrocarbon-based polymer electrolyte is more advantageous than the fluorine-based polymer electrolyte from the viewpoint of heat resistance and the like.
  • the polymer electrolyte may contain a combination of a fluorine-based polymer electrolyte and a hydrocarbon-based polymer electrolyte.
  • the molecular electrolyte is preferably 51% by weight or more, more preferably 70% by weight or more, still more preferably 85% by weight or more, still more preferably 90% by weight or more.
  • the hydrocarbon-based polymer electrolyte means a polymer electrolyte having a halogen atom content of 15% by weight or less in terms of the weight content ratio of elements constituting the polymer electrolyte.
  • Such hydrocarbon polymer electrolytes have the advantage of being inexpensive compared to the fluorine polymer electrolytes described above, and therefore more preferred, particularly preferred hydrocarbon polymer electrolytes substantially contain halogen atoms.
  • a hydrocarbon-based polymer electrolyte does not generate hydrogen halide during the operation of the fuel cell and does not corrode other members.
  • a fluorine-type polymer electrolyte means the polymer electrolyte in which a fluorine atom exceeds 15 weight% expressed with the weight content ratio of the element which comprises the said polymer electrolyte. Specific examples include the above-described commercially available fluorine-based polymer electrolytes.
  • the ion exchange group examples include an acidic ion exchange group (that is, a cation exchange group) or a basic ion exchange group (that is, an anion exchange group). From the viewpoint of obtaining high proton conductivity, the ion exchange group is preferably a cation exchange group. By using a polymer electrolyte having a cation exchange group, a fuel cell having further excellent power generation performance can be obtained.
  • the cation exchange group include a sulfo group (—SO 3 H), carboxyl group (—COOH), phosphone group (—PO) 3 H 2 ), Sulfonylimide group (-SO 2 NHSO 2 -), Phenolic hydroxyl groups and the like.
  • a sulfo group or a phosphone group is more preferable, and a sulfo group is particularly preferable.
  • These ion exchange groups may be partially or wholly exchanged with metal ions or quaternary ammonium ions to form a salt, but when used as a fuel cell member, It is preferred that substantially all are in the free acid form.
  • These ion exchange groups may be introduced into either or both of the main chain and the side chain of the polymer electrolyte, preferably those introduced into the main chain.
  • a hydrocarbon polymer electrolyte having a suitable ion exchange group will be described in detail.
  • hydrocarbon polymer electrolytes include polymer electrolytes represented by the following (A) to (F).
  • A a polymer electrolyte in which an ion exchange group is introduced into a polymer whose main chain is an aliphatic hydrocarbon
  • B a polymer electrolyte in which an ion exchange group is introduced into a polymer in which the main chain is composed of an aliphatic hydrocarbon and a part of the hydrogen atoms of the main chain is substituted with fluorine atoms
  • C a polymer electrolyte in which an ion exchange group is introduced into a polymer having a main chain having an aromatic ring
  • D a polymer electrolyte in which an ion exchange group is introduced into a polymer whose main chain has an inorganic unit structure such as a siloxane group or a phosphazene group
  • E An ion exchange group is introduced into a copolymer obtained by combining two or more structural units selected
  • Polymer electrolytes (F) A polymer electrolyte in which an acidic compound such as sulfuric acid or phosphoric acid is introduced into a hydrocarbon polymer containing a nitrogen atom in the main chain or side chain by ionic bond
  • an acidic compound such as sulfuric acid or phosphoric acid
  • a polymer electrolyte in which the ion exchange group is a sulfo group is mainly exemplified, but a polymer electrolyte in which the sulfo group is replaced with another ion exchange group may be used.
  • the polymer electrolyte (A) include polyvinyl sulfonic acid, polystyrene sulfonic acid, poly ( ⁇ -methylstyrene) sulfonic acid, and the like.
  • a polymer produced by copolymerization of a fluorocarbon vinyl monomer and a hydrocarbon vinyl monomer described in JP-A-9-102322 has a main chain, and a sulfo group.
  • a sulfonic acid type polystyrene-graft-ethylene-tetrafluoroethylene copolymer (ETFE) having a side chain as a hydrocarbon chain and having a copolymerization mode of graft polymerization.
  • a copolymer of a fluorocarbon vinyl monomer and a hydrocarbon vinyl monomer obtained by the method described in U.S. Pat. No. 4,012,303 or U.S. Pat. No.
  • sulfonic acid type poly (trifluorostyrene) -graft-ETFE obtained by graft polymerization of .beta.,. Beta.-trifluorostyrene and introducing a sulfo group into the solid polymer electrolyte can also be mentioned.
  • the polymer electrolyte (C) may contain a hetero atom such as an oxygen atom in the main chain.
  • polymer electrolyte examples include polyether ketone, polyether ether ketone, polysulfone, polyether sulfone, polyether ether sulfone, poly (arylene ether), polyimide, poly ((4-phenoxybenzoyl) -1, 4-phenylene), polyphenylquinoxalene and the like each having a sulfo group introduced therein.
  • Specific examples include sulfoarylated polybenzimidazoles and sulfoalkylated polybenzimidazoles (for example, see JP-A-9-110882).
  • the polymer electrolyte (C) may be a compound in which the main chain is interrupted by a heteroatom such as an oxygen atom.
  • Such a polymer electrolyte is disclosed in JP-A-9-110882 and J.A. Appl. Polym. Sci. 18, 1969 (1974).
  • Examples of the polymer electrolyte (D) include those in which a sulfo group is introduced into polyphosphazene. These can be found in Polymer Prep. , 41, no. 1, 70 (2000).
  • the polymer electrolyte (E) may be any of a random copolymer having a sulfo group introduced therein, an alternating copolymer having a sulfo group introduced therein, and a block copolymer having a sulfo group introduced therein.
  • Examples of the polymer electrolyte (F) include polybenzimidazole containing phosphoric acid as described in JP-T-11-503262.
  • an aromatic hydrocarbon polymer electrolyte particularly one having an aromatic ring in the main chain (that is, the above (C)) is preferable. It is also preferable because of its excellent mechanical strength and high heat resistance.
  • a hydrocarbon system having an aromatic ring constituting the main chain and having an ion exchange group directly bonded to the aromatic ring or indirectly bonded through another atom or atomic group A polymer electrolyte is preferred.
  • it may have aromatics constituting the main chain, and may further have side chains having aromatic rings, and directly bonded to either the aromatic ring constituting the main chain or the aromatic ring of the side chain.
  • Hydrocarbon polymer electrolytes having ion exchange groups are preferred.
  • a copolymer composed of a structural unit having an ion exchange group and a structural unit having no ion exchange group is used as the polymer electrolyte membrane. It is preferable because it tends to be excellent in water resistance and mechanical strength.
  • the copolymerization mode of these two kinds of structural units may be any of random copolymerization, alternating copolymerization, block copolymerization, and graft copolymerization, preferably random copolymerization, block copolymerization, and graft copolymerization.
  • the amount of ion exchange groups responsible for proton conductivity is preferably 0.5 meq / g or more, more preferably 1.0 meq / g or more, expressed in terms of ion exchange capacity. It is more preferably 2.0 meq / g or more, and particularly preferably 2.7 meq / g or more. Moreover, 5.5 meq / g or less is preferable and 5.0 meq / g or less is more preferable.
  • Z and Z ′ are the same or different and are each a group represented by —CO—, —SO— 2 -Represents one of the groups represented by-, X, X ', and X "are the same or different, and represent either a group represented by -O- or a group represented by -S-.
  • Y represents a direct bond or Represents a group represented by the following general formula (15), p represents 0, 1 or 2, and q and r are the same or different and represent 1, 2 or 3.
  • Ar 11 ⁇ Ar 19 Represent the same or different divalent aromatic groups which may have a substituent as a side chain.
  • Z and Z ′ are the same or different and are each a group represented by —CO—, —SO— 2 -Represents one of the groups represented by-, X, X ', and X "are the same or different, and represent either a group represented by -O- or a group represented by -S-.
  • Y represents directly or below.
  • a structural unit having no ion-exchange group, and the copolymerization mode is random copolymerization, block copolymerization, block copolymerization or graft copolymerization, or a copolymerization mode thereof.
  • a combined polymer electrolyte is exemplified. (Wherein R 1 And R 2 Are the same or different and each has a hydrogen atom, an optionally substituted alkyl group having 1 to 20 carbon atoms, an optionally substituted alkoxy group having 1 to 20 carbon atoms, or a substituent.
  • An aryl group having 6 to 20 carbon atoms which may be substituted, an aryloxy group having 6 to 20 carbon atoms which may have a substituent, or an acyl group having 2 to 21 carbon atoms which may have a substituent Represents R 1 And R 2 And may be linked to form a ring.
  • R 1 And R 2 Examples of the group of the formula (15) having a ring formed by linking with each other include a divalent cyclic hydrocarbon group having 5 to 20 carbon atoms such as a cyclohexylidene group. )
  • Ar in the formulas (11a) to (14a) 1 ⁇ Ar 9 Represents a divalent aromatic group.
  • the divalent aromatic group is a residue obtained by removing two hydrogen atoms from an aromatic compound.
  • the term “divalent aromatic group” is used in the same sense.
  • the divalent aromatic group include divalent monocyclic aromatic groups such as 1,3-phenylene and 1,4-phenylene, 1,3-naphthalenediyl, 1,4-naphthalenediyl, 1, Divalent condensed aromatic groups such as 5-naphthalenediyl, 1,6-naphthalenediyl, 1,7-naphthalenediyl, 2,6-naphthalenediyl, 2,7-naphthalenediyl, pyridinediyl, quinoxalinediyl, Thiophenediyl, pyrrole, 2H-pyrrole, imidazole, pyrazole, isoxazole, pyridine, pyrazine, pyrimidine, pyridazine, indolizine, isoindole, 3H-indo
  • a divalent monocyclic aromatic group is preferably a divalent condensed ring aromatic group, and more preferably a divalent monocyclic aromatic group.
  • Ar in the formulas (11a) to (14a) 1 ⁇ Ar 9 The hydrogen atom on the aromatic ring of the aromatic group represented by formula (1) is an optionally substituted alkyl group having 1 to 20 carbon atoms and an optionally substituted alkoxy group having 1 to 20 carbon atoms.
  • the aromatic group represented by has at least one ion-exchange group in the aromatic ring.
  • These ion exchange groups may be introduced into either or both of the main chain and the side chain of the polyelectrolyte, but preferably an aromatic group having at least one ion exchange group in the aromatic ring constituting the main chain. It is a family group.
  • an acidic ion exchange group is preferable as described above, and among the acidic ion exchange groups, a sulfo group or a phosphone group is more preferable, and a sulfo group is particularly preferable.
  • a structural unit represented by the following formula (14a-1) can be given.
  • Ar 110 , Ar 120 , Ar 130 Each independently represents a divalent aromatic group, and a hydrogen atom on the aromatic ring may be substituted with a fluorine atom.
  • Y is -CO-, -SO 2 -, -SO-, -CONH-, -COO-,-(CF 2 ) u000 -(U000 is an integer of 1 to 10), -C (CF 3 ) 2 -Or direct binding.
  • R 110 Is a direct bond, —O (CH 2 ) p000 -, -O (CF 2 ) p000 -,-(CH 2 ) p000 -Or-(CF 2 ) p000 -(P000 represents an integer of 1 to 12).
  • R 120 , R 130 Each independently represents a hydrogen atom, an alkali metal atom or a hydrocarbon group. However, all R contained in the above formula 120 And R 130 At least one of them is a hydrogen atom.
  • x100 is an integer of 0-4.
  • x200 is an integer of 1 to 5.
  • a000 is an integer of 0 to 1.
  • b000 represents an integer of 0 to 3.
  • Ar in the formula (14a-1) 110 , Ar 120 And Ar 130 Represents a divalent aromatic group. Examples of such a divalent aromatic group include Ar in the formulas (11a) to (14a). 1 ⁇ Ar 9 And the same divalent aromatic groups.
  • R 120 , R 130 Each independently represents a hydrogen atom, an alkali metal atom or a hydrocarbon group. Examples of the alkali metal atom include lithium, sodium, potassium, rubidium, cesium, and rubidium.
  • hydrocarbon group examples include a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, and a tert-butyl group.
  • 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 more preferable.
  • R 120 , R 130 Is preferably a hydrogen atom.
  • the structural unit represented by the above formula (14a-1) is preferably a structural unit represented by the following formula (14a-2).
  • p represents an integer of 1 to 12
  • m001 represents an integer of 0 to 10
  • n001 represents an integer of 0 to 10
  • k001 represents an integer of 1 to 4.
  • Specific examples of the structural unit having an ion exchange group represented by the above formula (14a-2) include structural units represented by the following formulas (4a-13) to (4a-20).
  • divalent aromatic groups include bivalent monocyclic aromatic groups such as 1,3-phenylene and 1,4-phenylene, 1,3-naphthalenediyl, and 1,4-naphthalenediyl.
  • 1,5-naphthalenediyl, 1,6-naphthalenediyl, 1,7-naphthalenediyl, 2,6-naphthalenediyl, 2,7-naphthalenediyl and the like divalent condensed aromatic groups such as pyridinediyl, Quinoxalinediyl, thiophenediyl, pyrrole, 2H-pyrrole, imidazole, pyrazole, isoxazole, pyridine, pyrazine, pyrimidine, pyridazine, indolizine, isoindole, 3H-indole, indole, 1H-indazole, purine, 4H-quinolidine, quinoline , Isoquinoline, phthalazine, naphthyridine, quinoxaline, quinazoline, syn Phosphorus, pteridine, carbazole, carboline, phenanthridine, acridine, perimidine
  • a divalent monocyclic aromatic group is preferably a divalent condensed ring aromatic group, and more preferably a divalent monocyclic aromatic group.
  • Ar 11 ⁇ Ar 19 The hydrogen atom on the aromatic ring of the aromatic group represented by the formula is a fluorine atom, a formyl group, a cyano group, an optionally substituted alkyl group having 1 to 20 carbon atoms, or a substituent.
  • the substituents of the aromatic group represented by Examples of the optionally substituted alkyl group having 1 to 20 carbon atoms include methyl group, ethyl group, butyl group, n-propyl group, isopropyl group, n-pentyl group, and 2,2-dimethylpropyl group.
  • An alkyl group having 1 to 20 carbon atoms such as a group, a cyclopentyl group, an n-hexyl group, a cyclohexyl group, a 2-methylpentyl group, a 2-ethylhexyl group, a nonyl group, a dodecyl group, a hexadecyl group, an octadecyl group, and an icosyl group; These groups are substituted with fluorine atoms, hydroxyl groups, nitrile groups, amino groups, methoxy groups, ethoxy groups, isopropyloxy groups, phenyl groups, naphthyl groups, phenoxy groups, naphthyloxy groups, etc., and the total number of carbon atoms is 20 or less.
  • alkyl group which is is mentioned.
  • alkoxy group having 1 to 20 carbon atoms which may have a substituent include, for example, a methoxy group, an ethoxy group, a butoxy group, an n-propoxy group, an isopropoxy group, an n-pentoxy group, and 2,2-dimethyl.
  • An alkoxy group having 1 to 20 carbon atoms such as a propoxy group, a cyclopentoxy group, an n-hexoxy group, a cyclohexoxy group, a 2-methylpentoxy group, a 2-ethylhexoxy group, a dodecyloxy group, a hexadecyloxy group, and an icosyloxy group; And these groups are substituted with fluorine atoms, hydroxyl groups, nitrile groups, amino groups, methoxy groups, ethoxy groups, isopropyloxy groups, phenyl groups, naphthyl groups, phenoxy groups, naphthyloxy groups, etc.
  • the following alkoxy groups are mentioned.
  • aryl groups such as a phenyl group, a naphthyl group, a phenanthrenyl group, and an anthracenyl group, and these groups include a fluorine atom, a hydroxyl group, and a nitrile.
  • Group, amino group, methoxy group, ethoxy group, isopropyloxy group, phenyl group, naphthyl group, phenoxy group, naphthyloxy group and the like are substituted, and aryl groups having a total carbon number of 20 or less can be mentioned.
  • acyl group having 2 to 21 carbon atoms which may have a substituent include an acetyl group, a propionyl group, a butyryl group, an isobutyryl group, a pivaloyl group, a benzoyl group, a 1-naphthoyl group, and a 2-naphthoyl group.
  • an acyl group having a total carbon number of 21 or less an acyl group having a total carbon number of 21 or less.
  • Aromatic ring substituents include aryl groups such as phenyl group, naphthyl group, phenanthrenyl group, anthracenyl group, aryloxy groups such as phenoxy group, naphthyloxy group, phenanthrenyloxy group, anthracenyloxy group, benzoyl group,
  • An acyl group having an aromatic ring such as a 1-naphthoyl group or a 2-naphthoyl group is preferred because the heat resistance of the polymer tends to be good, and a more practical fuel cell member can be obtained.
  • a polymer electrolyte including a polymer having an acyl group having an aromatic ring as an aromatic ring substituent, two structural units having the acyl group are adjacent to each other, and the acyl groups in the two structural units are bonded to each other. In this way, after the acyl groups are bonded to each other, a rearrangement reaction may occur. In addition, whether or not such a reaction that the aromatic ring substituents are bonded to each other or a rearrangement reaction is generated after the bonding occurs is, for example, 13 This can be confirmed by measuring the C-nuclear magnetic resonance spectrum.
  • the hydrocarbon-based polymer electrolyte has a structural unit having an ion exchange group and a structural unit not having an ion exchange group, and a dense phase of the structural unit having an ion exchange group forms a continuous phase in the film thickness direction. If it can be formed, it is preferable because there is an advantage that a polymer electrolyte membrane having more excellent proton conductivity can be obtained.
  • suitable polymer electrolytes are represented by the structural units having an ion exchange group composed of the structural units represented by the formulas (11a) to (14a) and the formulas (11b) to (14b). And a structural unit having no ion exchange group.
  • ⁇ a> to ⁇ m> in Table 1 More preferably, ⁇ b>, ⁇ c>, ⁇ d>, ⁇ g>, ⁇ h>, ⁇ i>, ⁇ j>, ⁇ l>, or ⁇ m>, and even more preferably ⁇ g> , ⁇ H>, ⁇ l>, or ⁇ m>, ⁇ g>, ⁇ h>, ⁇ l> are particularly preferable.
  • suitable copolymers include one or more structural units selected from the group of structural units having an ion exchange group shown below, and a group of structural units having no ion exchange group shown below. And a copolymer composed of one or more structural units.
  • these structural units may be directly bonded or may be bonded with an appropriate atom or atomic group.
  • a divalent aromatic group, an oxygen atom, a sulfur atom, a carbonyl group, a sulfonyl group, or a divalent group formed by combining these is used. I can give you.
  • r000 represents 0 or an integer of 1 or more. r000 is preferably 100 or less, more preferably 1 or more and 80 or less.
  • the formula representing the structural unit having an ion exchange group includes (4a-1) and / or (4a-2) and / or (4a-3) and / or (4a-4).
  • the formula representing the structural unit having no ion exchange group includes (4b-1) and / or (4b-2) and / or (4b-3) and / or (4b-4).
  • the hydrocarbon-based polymer electrolyte has a structural unit having an ion exchange group and a structural unit not having an ion exchange group.
  • the copolymerization mode of these two structural units is random copolymerization, Any of alternating copolymerization, block copolymerization, and graft copolymerization may be used, or a combination of these copolymerization modes may be used. Random copolymerization, block copolymerization, and graft copolymerization are preferred, random copolymerization and block copolymerization are more preferred, and block copolymerization is particularly preferred.
  • suitable block copolymers are represented by the above-mentioned formulas (11b) to (14b) and segments having an ion exchange group, which are composed of structural units represented by the above formulas (11a) to (14a). And a segment having substantially no ion exchange group. Further, combinations of the structural unit constituting the segment having a suitable ion exchange group and the structural unit constituting the segment having substantially no ion exchange group are shown in ⁇ a> to ⁇ m> in Table 2 below. A combination of segments can be given.
  • ⁇ b>, ⁇ c>, ⁇ d>, ⁇ g>, ⁇ h>, ⁇ i>, ⁇ j>, ⁇ l>, or ⁇ m> are particularly preferable.
  • the block copolymer according to the present invention is that the main chain of the segment having an ion exchange group has a polyarylene structure in which a plurality of aromatic rings are directly connected.
  • the structural unit of such a segment is preferably the above-mentioned (4a-10) and / or (4a-11) and / or (4a-12) and / or (4a-13) and / or (4a-14) And / or (4a-15) and / or (4a-16) and / or (4a-17) and / or (4a-18) and / or (4a-19) and / or (4a-20) More preferred is (4a-10) and / or (4a-11) and / or (4a-12), and particularly preferred is (4a-11) and / or (4a-12).
  • a polymer electrolyte having such a structural unit as a segment containing a repeating unit (that is, a segment having an ion exchange group), in particular, a polymer electrolyte having a segment consisting of such a repeating unit has excellent ion conductivity. Since the segment has a polyarylene structure, the chemical stability tends to be relatively good.
  • the “polyarylene structure” is a form in which the aromatic rings constituting the main chain are directly bonded to each other. Specifically, the total number of bonds between the aromatic rings is 100%. In some cases, the direct bond ratio is preferably 80% or more, more preferably 90% or more, and even more preferably 95% or more.
  • bonded by the direct bond are forms in which aromatic rings are couple
  • a formula representing a structural unit used as a repeating unit constituting a segment having no ion exchange group (4b-1) and / or (4b-2) and / or (4b-3) and / or (4b- 4) and / or (4b-5) and / or (4b-6) and / or (4b-7) and / or (4b-8) and / or (4b-9) and / or (4b-10) And / or (4b-11) and / or (4b-12) and / or (4b-13) and / or (4b-14) are preferred, (4b-2) and / or (4b-3) ) And / or (4b-9) and / or (4b-10) and / or (4b-13) and / or (4b-14) are more preferred, (4b-2) and / or (4b-3) And / or (4b-13) and
  • segment having an ion exchange group and the segment having substantially no ion exchange group may be directly bonded or may be connected by an appropriate atom or atomic group.
  • atoms or atomic groups connecting the segments a divalent aromatic group, an oxygen atom, a sulfur atom, a carbonyl group, a sulfonyl group, or a divalent group formed by combining these is given. be able to.
  • Examples of a suitable block copolymer include a segment containing one or more structural units selected from the group of structural units having an ion exchange group shown above (ie, a segment having an ion exchange group), and the above A block copolymer comprising a segment containing one or more structural units selected from the group of structural units having no ion-exchange groups shown in (1), and a segment having substantially no ion-exchange groups.
  • the “segment having an ion exchange group” means a segment in which an ion exchange group is contained in an average of 0.5 or more per structural unit constituting the segment, and per structural unit It is more preferable that the average number of ion exchange groups is 1.0 or more.
  • the “segment having substantially no ion-exchange group” means a segment having an average number of ion-exchange groups of less than 0.5 per structural unit constituting the segment.
  • the average number of ion exchange groups is more preferably 0.1 or less, and even more preferably 0.05 or less on average.
  • a block copolymer in a form in which a segment having an ion exchange group and a segment having substantially no ion exchange group are bonded by a direct bond or bonded by an appropriate atom or atomic group. is there.
  • the degree of polymerization of the segment composed of one or more structural units selected from the structural units represented by the above formulas (11a) to (14a) is 2 or more, preferably 3 or more, more preferably 5 or more, and more preferably 10 or more. Further preferred. Further, the polymerization degree of the segment is preferably 1000 or less, and preferably 500 or less. If the degree of polymerization is 2 or more, preferably 5 or more, sufficient proton conductivity is expressed as a polymer electrolyte for a fuel cell, and if the degree of polymerization is 1000 or less, the advantage is that manufacture is easier. There is.
  • the degree of polymerization of a segment composed of a structural unit selected from structural units represented by formulas (11b) to (14b) is 1 or more, preferably 2 or more, and more preferably 3 or more. Further, the polymerization degree of the segment is preferably 100 or less, more preferably 90 or less, and still more preferably 80 or less. Within such a range, the polymer electrolyte for fuel cells is preferable because it has sufficient mechanical strength and is easy to produce. Further, the molecular weight of the hydrocarbon-based polymer electrolyte used in the present invention is preferably 5000 to 1,000,000, more preferably 10,000 to 800,000, and more preferably 10,000 to 600,000 in terms of polystyrene-reduced number average molecular weight.
  • the polymer electrolyte membrane of the present invention includes a polymer electrolyte composition containing the above sulfur-containing aromatic compound and a polymer electrolyte.
  • the polymer electrolyte membrane is preferably a polymer electrolyte membrane produced by a solution casting method including the following steps (i) to (iv).
  • a polymer electrolyte solution is prepared as described above.
  • an organic solvent used for preparing the polymer electrolyte solution a solvent capable of dissolving one or more polymer electrolytes to be used is selected.
  • dissolve these other components together is preferable.
  • the organic solvent used is a solvent that can dissolve the polyelectrolyte and / or polyelectrolyte composition to be used.
  • the polyelectrolyte and / or polyelectrolyte composition is added at 1% by weight at 25 ° C. It is an organic solvent that can be dissolved at the above concentrations. More preferably, an organic solvent capable of dissolving the polymer electrolyte and / or the polymer electrolyte composition at a concentration of 5 to 50% by weight is used.
  • the organic solvent needs to be volatile enough to be removed by heat treatment after the polymer electrolyte casting film is formed on the support substrate.
  • the organic solvent preferably contains at least one organic solvent having a boiling point of 150 ° C. or higher at 101.3 kPa (1 atm).
  • the organic solvent is removed from the polymer electrolyte casting membrane in the step (iii) described later. If an attempt is made to form a polymer electrolyte membrane, the formed polymer electrolyte membrane may have irregular appearance defects.
  • Suitable organic solvents for the preparation of the polymer electrolyte solution include dimethylformamide (DMF), dimethylacetamide (DMAc), N-methyl-2-pyrrolidone (NMP), dimethyl sulfoxide (DMSO), and ⁇ -butyrolactone (GBL).
  • DMF dimethylformamide
  • DMAc dimethylacetamide
  • NMP N-methyl-2-pyrrolidone
  • DMSO dimethyl sulfoxide
  • GBL ⁇ -butyrolactone
  • Aprotic polar solvents such as, chlorinated solvents such as dichloromethane, chloroform, 1,2-dichloroethane, chlorobenzene, dichlorobenzene, alcohols such as methanol, ethanol, propanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene
  • chlorinated solvents such as dichloromethane, chloroform, 1,2-dichloroethane, chlorobenzene, dichlorobenzene
  • alcohols such as methanol, ethanol, propanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene
  • alkylene glycol monoalkyl ethers such as glycol monomethyl ether and propylene glycol monoethyl ether.
  • the “organic solvent substantially consisting of an aprotic polar solvent” as used herein does not exclude the presence of moisture or the like unintentionally contained.
  • the aprotic polar solvent has an advantage that the affinity for the supporting substrate is relatively small and the aprotic polar solvent is hardly absorbed by the supporting substrate.
  • DMSO, DMF, DMAc, NMP, GBL or two or more selected from these are used among the aprotic polar solvents. Mixed solvents are preferred.
  • process (ii) is demonstrated.
  • This step is a step in which the polymer electrolyte solution obtained in the step (i) is cast-coated on a supporting substrate.
  • the casting coating method various means such as a roller coating method, a spray coating method, a curtain coating method, a slot coating method, a screen printing method and the like can be used.
  • Means for shaping the polymer electrolyte solution to a predetermined width and thickness can be given by the obtained mold.
  • the polymer electrolyte casting film formed on the support substrate has a film shape because a part of the organic solvent in the polymer electrolyte solution volatilizes during coating.
  • the thickness of the polymer electrolyte casting membrane is preferably 3 to 50 ⁇ m.
  • the polymer electrolyte concentration of the polymer electrolyte solution to be used, the coating amount of the coating apparatus, etc. may be appropriately adjusted.
  • this support base material is a base material which runs continuously, it can also be adjusted by the running speed of the support base material.
  • the supporting substrate used in the step (ii) has sufficient durability against the polymer electrolyte solution used for the casting coating, and also durable against the processing conditions in the step (iii) described later. A material made of a material having is selected.
  • the durability means that the supporting base material itself is not substantially dissolved by the polymer electrolyte solution, and that the supporting base material itself does not swell or shrink depending on the processing conditions of step (iii). Means something good.
  • the supporting substrate include glass plates; metal foils such as SUS foil and copper foil; and plastic films such as polyethylene terephthalate (PET) film and polyethylene naphthalate (PEN) film.
  • PET polyethylene terephthalate
  • PEN polyethylene naphthalate
  • the plastic film may be subjected to surface treatment such as UV treatment, mold release treatment, embossing treatment, and the like within a range that does not significantly impair the durability as described above.
  • step (iii) will be described.
  • the organic solvent contained in the polymer electrolyte casting film formed on the support substrate in the step (ii) is removed to form a polymer electrolyte membrane on the support substrate. It is. For such removal, drying or washing with a washing solvent is recommended. It is more preferable to combine the drying and washing to remove the organic solvent.
  • the drying and washing are combined, the polymer formed on the support substrate is first dried. It is particularly preferable to perform washing with a washing solvent after removing almost all of the organic solvent contained in the electrolyte casting membrane.
  • the drying and washing which are suitable methods as the step (iii), are performed in this order.
  • first laminated film the support substrate (hereinafter, sometimes referred to as “first laminated film”) on which the polymer electrolyte casting film is formed is heat-treated by direct heating, hot air contact, or the like. Hot air treatment is particularly preferable in that the polymer electrolyte in the polymer electrolyte casting membrane is not significantly impaired.
  • the first laminated film may be passed through a drying furnace. .
  • the drying furnace at this time is warm air set at a temperature in the range of 40 to 150 ° C., preferably 50 to 140 ° C., along the direction perpendicular to the passing direction of the first laminated film and / or the facing direction. Blow.
  • the volatile component such as the organic solvent is dried (evaporated) from the polymer electrolyte casting film on the support substrate, and the second laminate in which the polymer electrolyte film is formed on the support substrate.
  • a film is formed. Since the polymer electrolyte membrane of the second laminated film thus obtained still contains a slight amount of organic solvent, this organic solvent is washed with a washing solvent. By washing with a washing solvent, a polymer electrolyte membrane excellent in appearance and the like can be easily obtained.
  • the cleaning solvent a mixed solvent composed of DMSO, DMF, DMAc, NMP, GBL, or a combination thereof, which is a suitable organic solvent in the preparation of the polymer electrolyte solution
  • pure water particularly ultrapure water.
  • the second laminated film formed continuously through the drying furnace is filled with, for example, a cleaning solvent. It can wash
  • this winding body is transferred to the washing
  • the polymer electrolyte membrane can be obtained by removing the supporting substrate from the second laminated film thus obtained by peeling or the like. Since this polymer electrolyte membrane is obtained by a suitable solution casting method, it becomes a substantially non-porous membrane.
  • substantially non-porous means that minute through holes such as voids are not formed in the polymer electrolyte membrane.
  • the polymer electrolyte membrane may be a membrane having such a void as long as it is a small amount of voids or a small diameter void that does not hinder the operation of the fuel cell.
  • the polymer electrolyte membrane production by the solution casting method described above the case where the supporting base material is continuously running has been described. Of course, even if a single-wafer supporting base material is used, the polymer electrolyte membrane is not used. Obtainable.
  • the polymer electrolyte solution coated on the supporting substrate of the single wafer can be removed in a suitable drying furnace, the organic solvent can be removed, and the sheet thus obtained
  • the second laminated film of leaves can be cleaned by immersing it in a cleaning tank equipped with a cleaning solvent.
  • the second laminated film after washing may be subjected to dry removal of the remaining or adhering washing solvent, or the second laminated film after washing is heated as it is.
  • the supporting base material may be removed.
  • the method for producing a substantially non-porous polymer electrolyte membrane by the solution casting method has been described above.
  • this polymer electrolyte membrane includes other than the above sulfur-containing aromatic compound and polymer electrolyte. (Hereinafter, may be referred to as “other components”).
  • other components include additives such as plasticizers, stabilizers, mold release agents, and water retention agents that are used in ordinary polymers.
  • the fuel cell of the present invention can be produced by bonding a catalyst and a conductive material as a current collector to both surfaces of the polymer electrolyte membrane of the present invention.
  • the catalyst is not particularly limited as long as it can activate the oxidation-reduction reaction with hydrogen or oxygen, and a known catalyst can be used. However, platinum or platinum alloy fine particles can be used as the catalyst. preferable.
  • the fine particles of platinum or platinum-based alloys are often used by being supported on particulate or fibrous carbon such as activated carbon or graphite.
  • a paste (catalyst ink) prepared by mixing platinum or a platinum-based alloy supported on carbon with a solvent of a perfluoroalkyl sulfonic acid resin is applied to the gas diffusion layer and dried, whereby A laminated and integrated catalyst layer is obtained.
  • a membrane-electrode assembly for a fuel cell can be obtained.
  • J. Org. Electrochem. Soc. Known methods such as those described in Electrochemical Science and Technology, 1988, 135 (9), 2209 can be used.
  • a membrane-electrode assembly for a fuel cell can be obtained by applying a catalyst ink to a polymer electrolyte membrane and drying it to form a catalyst layer directly on the surface of the membrane.
  • the polymer electrolyte used in the catalyst layer the polymer electrolyte and / or polymer electrolyte composition of the present invention can be used instead of the perfluoroalkyl sulfonic acid resin to form a catalyst composition.
  • a catalyst layer obtained using this catalyst composition is suitable as a catalyst layer because it can exhibit good long-term stability as in the case of the polymer electrolyte membrane.
  • a known material can be used for the conductive material as the current collector, but porous carbon woven fabric, carbon non-woven fabric, or carbon paper is preferable in order to efficiently transport the raw material gas to the catalyst.
  • the fuel cell of the present invention thus produced can be used in various forms using hydrogen gas, reformed hydrogen gas, and methanol as fuel.
  • the sulfur-containing aromatic compound introduced into the polymer electrolyte membrane may migrate to the catalyst layer. Such a transition may occur during a process of joining a catalyst and a conductive material as a current collector to both surfaces of the polymer electrolyte membrane and / or during operation of the fuel cell.
  • the operation means any one of aging, starting, operating and stopping of the fuel cell.
  • Such a form is also preferable because it can exhibit good long-term stability, like the polymer electrolyte membrane and the catalyst layer.
  • Example 1 Manufacture of membrane containing thianthrene>
  • this polymer electrolyte solution was uniformly spread on a PET substrate, and then the polymer electrolyte solution was dried at 90 ° C. under normal pressure.
  • the obtained dried coating film was immersed and washed in 2N sulfuric acid, then washed with ion-exchanged water, further dried at room temperature, and peeled from the PET substrate to obtain a polymer electrolyte membrane A.
  • Example 2 ⁇ Fuel Cell Evaluation of Membrane Containing Thianthrene> (Manufacture of catalyst ink) 1.00 g of platinum-supported carbon (SA50BK, manufactured by N.E.
  • anode catalyst layer contained 0.6 mg / cm 2 of platinum calculated from the composition and coating weight.
  • catalyst ink was similarly applied to the surface of the polymer electrolyte membrane opposite to the anode catalyst layer to form a cathode catalyst layer containing 0.6 mg / cm 2 of platinum. As a result, a membrane-electrode assembly was obtained.
  • the long-term stability of polymer electrolyte membranes and fuel cells was evaluated by performing load fluctuation tests with an open circuit and a constant current. After operating the fuel cell under these conditions for about 200 hours, the membrane-electrode assembly was taken out, put into a mixed solution of ethanol / water, and further subjected to ultrasonic treatment to remove the catalyst layer. And the molecular weight of the segment which has the ion exchange group of the remaining polymer electrolyte membrane A was measured in the following procedure.
  • the GPC measurement conditions were as follows. ⁇ Column: TSKgel GMH HR- M manufactured by Tosoh Corporation -Column temperature: 40 ° C Mobile phase solvent: N, N-dimethylformamide (LiBr added to 10 mmol / dm3) Solvent flow rate: 0.5 mL / min. Detection: Differential refractive index comparative example 1 ⁇ Fuel cell evaluation of polymer electrolyte membrane B> In Example 1, a polymer electrolyte membrane B was obtained in the same manner except that thianthrene was not added. Further, a load fluctuation test was performed on the polymer electrolyte membrane B in the same manner as in Example 2, and GPC analysis was performed in the same manner.
  • Table 3 shows the weight average molecular weight of the segment having an ion exchange group before and after the load fluctuation test and the maintenance ratio of the weight average molecular weight of the segment having an ion exchange group before and after the load fluctuation test. From Table 3, the polymer electrolyte membrane prepared by adding the sulfur-containing aromatic compound of the present invention sufficiently maintains the molecular weight of the segment having an ion-exchange group even before and after the load fluctuation test, compared to the polymer electrolyte membrane not added. And has been found to have excellent long-term stability.
  • Example 3 ⁇ Production of membrane containing phenoxathiin>
  • the following formula A segment having a sulfonic acid group (segment having an ion-exchange group) and a repeating unit represented by the following formula:
  • a block copolymer B having a segment substantially free of ion-exchange groups (number average molecular weight 2.83 ⁇ 10 5 , weight average molecular weight 6.90 ⁇ 10 5 , molecular weight measurement conditions are the same as in Examples) 1 was prepared with reference to the method of [Synthesis of block copolymer B] described below.
  • the obtained polymerization solution was put into 3360 g of 13 wt% hydrochloric acid and stirred at room temperature for 30 minutes. After the resulting precipitate was filtered, 3360 g of 13 wt% hydrochloric acid was added, stirred at room temperature for 30 minutes, filtered, and washed with ion exchange water until the pH of the filtrate exceeded 4.
  • 840 g of ion exchanged water and 790 g of methanol were added, and the mixture was heated and stirred at a bath temperature of 90 ° C. for 1 hour.
  • the crude polymer was filtered and dried to obtain 23.9 g of a polymer (F) having a sulfonic acid precursor group (sulfonic acid (2,2-dimethylpropyl) group).
  • the sulfonic acid precursor group was converted to a sulfo group as follows. 23.9 g of the polymer (F) having a sulfonic acid precursor group obtained as described above, 47.8 g of ion-exchanged water, 15.9 g (183 mmol) of anhydrous lithium bromide and 478 g of N-methylpyrrolidone were placed in a flask. The mixture was heated and stirred at a bath temperature of 126 ° C. for 12 hours to obtain a polymer solution.
  • the obtained polymer solution was added to 3340 g of 13 wt% hydrochloric acid and stirred for 1 hour.
  • the operation of filtering the precipitated crude polymer and washing with 2390 g of a mixed solution of 10 parts by weight of methanol and 10 parts by weight of 35% hydrochloric acid was repeated three times. Thereafter, the filtrate was washed with ion-exchanged water until the pH of the filtrate exceeded 4. Subsequently, a large amount of ion-exchanged water was added to the obtained polymer, the temperature was raised to 90 ° C. or higher, and the washing operation in which heat was kept for about 10 minutes and filtration was repeated 5 times.
  • Example 4 ⁇ Production of membrane containing thioxanthone>
  • a polymer electrolyte membrane D was obtained by using thioxanthone instead of phenoxathiin.
  • a fuel cell using the polymer electrolyte membrane D is excellent in long-term stability.
  • Example 5 ⁇ Production of membrane containing dibenzothiophene>
  • a polymer electrolyte membrane E was obtained by using dibenzothiophene instead of phenoxathiin.
  • a fuel cell using the polymer electrolyte membrane E is excellent in long-term stability.
  • Example 6 ⁇ Production of membrane containing 4-benzoyl 4'-methyldiphenyl sulfide>
  • a polymer electrolyte membrane F was obtained by using 4-benzoyl 4′-methyldiphenyl sulfide instead of phenoxathiin.
  • a fuel cell using the polymer electrolyte membrane F is excellent in long-term stability.
  • Example 7 ⁇ Production of membrane containing thianthrene>
  • the polymer electrolyte referring to the method described in JP-A-2005-197236, as the polymer electrolyte, the following formula A segment having a sulfonic acid group (segment having an ion-exchange group) and a repeating unit represented by the following formula:
  • Example 8 ⁇ Fuel Cell Evaluation of Membrane Containing Thianthrene> Using the polymer electrolyte membrane G instead of the polymer electrolyte membrane A, a membrane-electrode assembly and a fuel cell having the membrane-electrode assembly were produced in the same manner as in Example 2. (Characteristic evaluation of fuel cell [open circuit test]) The characteristics of fuel cells manufactured using the polymer electrolyte membrane G were evaluated.
  • low humidified hydrogen 25 mL / min, back pressure 0.1 MPaG
  • low humidified state is supplied to the cathode catalyst layer side.
  • An open circuit test was performed by supplying air (63 mL / min, back pressure 0.05 MPaG).
  • Each source gas was humidified by passing the gas through a bubbler containing water. The water temperature of the hydrogen bubbler was 95 ° C., and the water temperature of the air bubbler was 30 ° C. Under these conditions, the fuel cell was continuously operated for 100 hours. After the test, the polymer electrolyte membrane was taken out and subjected to GPC analysis in the same manner as in Example 2.
  • Table 4 shows the maintenance ratio of the weight average molecular weight of the segments having ion exchange groups before and after the test. Comparative Example 2 ⁇ Fuel Cell Evaluation of Block Copolymer C Membrane> In Example 7, a polymer electrolyte membrane H was obtained in the same manner except that thianthrene was not added. Further, the polymer electrolyte membrane H was evaluated by conducting a power generation characteristic test in the same manner as in Example 8. Table 4 shows the maintenance ratio of the weight average molecular weight of the segments having ion exchange groups before and after the test.
  • Example 9 ⁇ Production of membrane containing thianthrene> Thianthrene (0.05 g) was dissolved in 20 g of tetrahydrofuran, 2.88 g of a commercially available 20% by mass Nafion (registered trademark) solution (manufactured by Aldrich, solvent: mixture of water and lower alcohol), and 3.2 g of ethanol were added. For 6 hours to obtain a deterioration inhibitor solution.
  • the obtained deterioration inhibitor solution was applied to a 3 cm ⁇ 3 cm region at the center of one side of the Nafion XL (registered trademark) film by a spray method. At this time, the distance from the discharge port to the film was set to 6 cm, and the stage temperature was set to 60 ° C. Further, the deterioration preventing agent layer was formed by recoating and removing the solvent to obtain a polymer electrolyte membrane 001 having a solid content of 5.47 mg disposed in a 3 cm ⁇ 3 cm region.
  • Example 10 ⁇ Fuel Cell Evaluation of Membrane Containing Thianthrene> [Catalyst ink creation] Platinum-supported carbon (SA50BK, N.E.
  • Chemcat platinum-containing in which platinum is supported on 6.30 g of a commercially available 5% by mass Nafion (registered trademark) solution (manufactured by Aldrich, solvent: mixture of water and lower alcohol) (Amount: 50% by mass) 1.00 g was added, and 43.45 g of ethanol and 6.43 g of water were further added. The obtained mixture was subjected to ultrasonic treatment for 1 hour and then stirred with a stirrer for 5 hours to obtain a catalyst ink.
  • 5% by mass Nafion (registered trademark) solution manufactured by Aldrich, solvent: mixture of water and lower alcohol
  • a catalyst ink was similarly applied on the deterioration preventing agent layer to form a cathode catalyst layer, thereby obtaining a membrane electrode assembly.
  • As the cathode catalyst layer 14.2 mg of solid content (platinum weight: 0.6 mg / cm 2 ) was applied.
  • [Assembly of fuel cell] On both outer sides of the MEA obtained as described above, a carbon cloth as a gas diffusion layer and a carbon separator having a gas passage groove cut are arranged, and a current collector and an end plate are further provided on the outer side.
  • the fuel cells having an effective electrode area of 9 cm 2 were assembled by sequentially arranging them and fastening them with bolts.
  • Example 10 From Table 5, it can be seen that in Example 10, the elution rate of fluoride ions and sulfate ions in the wastewater is smaller than that of Comparative Example 3, and the deterioration of the polymer electrolyte is suppressed. From this, it was found that the sulfur-containing aromatic compound of the present invention is very useful as a stabilizer for a fluorine-based polymer electrolyte.
  • a fuel cell member such as a polymer electrolyte membrane having excellent radical resistance can be obtained. Since a fuel cell provided with such a fuel cell member has excellent long-term stability, it is extremely useful industrially.

Abstract

Provided is a polymer electrolyte composition which can be used to obtain a polymer electrolyte membrane enabling the implementation of a fuel cell having excellent long-term stability, said polymer electrolyte composition being characterized by containing a polymer electrolyte and at least one type of sulfur-containing aromatic compound from a group comprising four types of sulfur-containing aromatic compound.

Description

高分子電解質組成物および高分子電解質膜Polymer electrolyte composition and polymer electrolyte membrane
　本発明は、高分子電解質組成物および高分子電解質膜に関する。 The present invention relates to a polymer electrolyte composition and a polymer electrolyte membrane.
　固体高分子形燃料電池（以下、「燃料電池」と略記することがある。）は、水素と酸素の電気化学的反応を利用した発電装置であり、燃料電池に使用される高分子電解質膜として、フッ素系高分子電解質膜や炭化水素系高分子電解質膜が注目されている。
　フッ素系高分子電解質膜や炭化水素系高分子電解質膜を用いた燃料電池は、長期運転を行った場合の運転安定性（以下、「長期安定性」と呼ぶことがある）が必ずしも十分でないことが指摘されている。この長期安定性を妨げる要因の１つとして、電池稼動時に発生する過酸化物（例えば、過酸化水素等）又は該過酸化物から発生するラジカルによる膜の劣化が知られている。それゆえ、高分子電解質膜の過酸化物やラジカルに対する耐久性（以下、「ラジカル耐性」と呼ぶことがある）を向上させることが、固体高分子型燃料電池の長期安定性の向上に繋がるとされている。
　このようなラジカル耐性を向上させた高分子電解質膜として、特開２００３−２０１４０３号公報には、スルホン化ポリマーと、１，３，５−トリメチル−２，４，６−トリス（３，５−ジ−ｔ−ブチル−４−ヒドロキシベンジル）ベンゼンおよびビス（２，６−ジ−ｔ−ブチル−４−メチルフェニル）ペンタエリスリトールジホスファイトからなる酸化防止剤とを含む高分子電解質組成物からなる高分子電解質膜が記載されている。
　しかしながら、上記の酸化防止剤は、非脂肪族炭化水素系高分子電解質への分散性および相溶性が低く、酸化防止剤自体の耐久性も低い。そのため、上記の高分子電解質膜を備えた燃料電池は、電池の起動・停止を繰り返すような長期運転を行なうと、ラジカルによる高分子電解質膜の劣化によって、イオン伝導性が低下し易く、結果として燃料電池自体の発電性能が低下し易い。 A polymer electrolyte fuel cell (hereinafter sometimes abbreviated as “fuel cell”) is a power generation device that utilizes an electrochemical reaction between hydrogen and oxygen, and is used as a polymer electrolyte membrane used in a fuel cell. Fluorine polymer electrolyte membranes and hydrocarbon polymer electrolyte membranes have attracted attention.
A fuel cell using a fluorine-based polymer electrolyte membrane or a hydrocarbon-based polymer electrolyte membrane does not necessarily have sufficient operation stability (hereinafter referred to as “long-term stability”) when operated for a long time. Has been pointed out. As one of the factors that hinder this long-term stability, it is known that the film is deteriorated by peroxides (for example, hydrogen peroxide) generated during battery operation or radicals generated from the peroxides. Therefore, improving the durability of the polymer electrolyte membrane against peroxides and radicals (hereinafter sometimes referred to as “radical resistance”) leads to the improvement of the long-term stability of the polymer electrolyte fuel cell. Has been.
As such a polymer electrolyte membrane with improved radical resistance, Japanese Patent Application Laid-Open No. 2003-201403 discloses a sulfonated polymer, 1,3,5-trimethyl-2,4,6-tris (3,5- And a polyelectrolyte composition comprising an antioxidant comprising di-t-butyl-4-hydroxybenzyl) benzene and bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite. A polymer electrolyte membrane is described.
However, the antioxidant described above has low dispersibility and compatibility with non-aliphatic hydrocarbon polymer electrolytes, and the durability of the antioxidant itself is also low. Therefore, when the fuel cell having the above polymer electrolyte membrane is operated for a long time such as repeated start and stop of the battery, the ion conductivity is likely to be lowered due to the deterioration of the polymer electrolyte membrane due to radicals. The power generation performance of the fuel cell itself is likely to deteriorate.
　本発明の目的は、良好な長期安定性の燃料電池を実現する高分子電解質膜が得られる高分子電解質組成物、該高分子電解質組成物を用いた燃料電池部材および長期安定性に優れた固体高分子型燃料電池を提供することにある。
　本発明は下記［１］~［１１］を提供する。
［１］下記含硫黄芳香族化合物［Ａ］~［Ｄ］からなる群より選ばれる一種以上の含硫黄芳香族化合物と高分子電解質とを含有することを特徴とする高分子電解質組成物。
含硫黄芳香族化合物［Ａ］：下記式（１）で表される含硫黄芳香族化合物。
Figure JPOXMLDOC01-appb-I000007
（式（１）中、Ｙ１は硫黄原子を含む２価の基を表す。Ｃ１~Ｃ４はそれぞれ炭素原子を表す。環Ａｒ０１は、Ｃ１およびＣ２を含み、置換基を有していてもよい炭素数４~５０の芳香環を表す。環Ａｒ０２は、Ｃ３およびＣ４を含み、置換基を有していてもよい炭素数４~５０の芳香環を表す。Ａｒ０１が有していてもよい置換基およびＡｒ０２が有していてもよい置換基はそれぞれ、水酸基、ハロゲノ基、シアノ基、カルボキシ基、ホスホノ基、スルホ基、ホルミル基、メルカプト基、メチル基、置換基を有していてもよい炭素数４~２０のアリール基、置換基を有していてもよい炭素数４~２０のアリールオキシ基、置換基を有していてもよい炭素数４~２０のアリールチオ基、置換基を有していてもよい炭素数５~２１のアロイル基および置換基を有していてもよい炭素数４~２０のアリールスルホニル基からなる群より選ばれる１種以上の基である。Ｘ１およびＸ２は、それぞれ同一または相異なり、水素原子、水酸基、ハロゲノ基、シアノ基、カルボキシ基、ホスホノ基、スルホ基、ホルミル基、メルカプト基、メチル基、置換基を有していてもよい炭素数４~２０のアリール基、置換基を有していてもよい炭素数４~２０のアリールオキシ基、置換基を有していてもよい炭素数４~２０のアリールチオ基、置換基を有していてもよい炭素数５~２１のアロイル基または置換基を有していてもよい炭素数４~２０のアリールスルホニル基を表す。）
含硫黄芳香族化合物［Ｂ］：下記式（２）で表される含硫黄芳香族化合物。
Figure JPOXMLDOC01-appb-I000008
（式（２）中、Ｙ１は上記と同義である。Ｚ１は、直接結合、下記式（２−１）~（２−９）のいずれかで示される２価の基を表す。Ｃ５~Ｃ８はそれぞれ炭素原子を表す。環Ａｒ０３は、Ｃ５およびＣ６を含み、置換基を有していてもよい炭素数４~５０の芳香環を表す。環Ａｒ０４は、Ｃ７およびＣ８を含み、置換基を有していてもよい炭素数４~５０の芳香環を表す。
Figure JPOXMLDOC01-appb-I000009
（式（２−１）~（２−９）中、Ｅ１は水素原子、水酸基、メチル基、メトキシ基または炭素数４~５０の芳香族基を表す。））
含硫黄芳香族化合物［Ｃ］：下記式（３）で表される含硫黄芳香族化合物。
Figure JPOXMLDOC01-appb-I000010
（式（３）中、Ｙ１およびＺ１はそれぞれ上記と同義である。Ｃ９~Ｃ１２はそれぞれ炭素原子を表す。Ｘ３~Ｘ６は、それぞれ同一または相異なり、水素原子、水酸基、ハロゲノ基、シアノ基、カルボキシ基、ホスホノ基、スルホ基、ホルミル基、メルカプト基、置換基を有していてもよい炭素数１~２０のアルキル基、置換基を有していてもよい炭素数１~２０のアルコキシ基、置換基を有していてもよい炭素数１~２０のアルキルチオ基、置換基を有していてもよい炭素数３~２０のアリール基、置換基を有していてもよい炭素数３~２０のアリールオキシ基、置換基を有していてもよい炭素数３~２０のアリールチオ基、置換基を有していてもよい炭素数２~２１のアシル基、置換基を有していてもよい炭素数４~２１のアロイル基、置換基を有していてもよい炭素数３~２０のアリールスルホニル基または置換基を有していてもよい炭素数１~２０のアルキルスルホニル基を表す。Ｚ１が直接結合の場合、Ｘ４およびＸ５は互いに結合することにより、環を形成していてもよい。）
含硫黄芳香族化合物［Ｄ］：下記式（４）で表される含硫黄芳香族化合物。
Figure JPOXMLDOC01-appb-I000011
（式（４）中、Ｙ１およびＺ１は上記と同義である。Ｃ１３~Ｃ１６はそれぞれ炭素原子を表す。環Ａｒ０５は、Ｃ１５およびＣ１６を含み、置換基を有していてもよい炭素数４~５０の芳香環を表す。Ｘ７およびＸ８は、それぞれ同一または相異なり、水素原子、水酸基、ハロゲノ基、シアノ基、カルボキシ基、ホスホノ基、スルホ基、ホルミル基、メルカプト基、置換基を有していてもよい炭素数１~２０のアルキル基、置換基を有していてもよい炭素数１~２０のアルコキシ基、置換基を有していてもよい炭素数１~２０のアルキルチオ基、置換基を有していてもよい炭素数３~２０のアリール基、置換基を有していてもよい炭素数３~２０のアリールオキシ基、置換基を有していてもよい炭素数３~２０のアリールチオ基、置換基を有していてもよい炭素数２~２１のアシル基、置換基を有していてもよい炭素数４~２１のアロイル基、置換基を有していてもよい炭素数３~２０のアリールスルホニル基または置換基を有していてもよい炭素数１~２０のアルキルスルホニル基を表す。）
［２］前記高分子電解質組成物が含有する前記含硫黄芳香族化合物は、含硫黄芳香族化合物［Ｂ］~［Ｄ］からなる群より選ばれる一種以上の含硫黄芳香族化合物であることを特徴とする［１］に記載の高分子電解質組成物。
［３］上記Ｙ１が硫黄原子またはスルフィニル基であることを特徴とする［１］または［２］に記載の高分子電解質組成物。
［４］上記含硫黄芳香族化合物［Ｂ］が下記式（６）で表されることを特徴とする［１］~［３］のいずれかに記載の高分子電解質組成物。
Figure JPOXMLDOC01-appb-I000012
（式（６）中、Ｙ１およびＺ１はそれぞれ上記と同義である。Ｒ０１~Ｒ０８は、それぞれ同一または相異なり、水素原子、水酸基、ハロゲノ基、シアノ基、カルボキシ基、ホスホノ基、スルホ基、ホルミル基、メルカプト基、置換基を有していてもよい炭素数１~２０のアルキル基、置換基を有していてもよい炭素数１~２０のアルコキシ基、置換基を有していてもよい炭素数１~２０のアルキルチオ基、置換基を有していてもよい炭素数３~２０のアリール基、置換基を有していてもよい炭素数３~２０のアリールオキシ基、置換基を有していてもよい炭素数３~２０のアリールチオ基、置換基を有していてもよい炭素数２~２１のアシル基、置換基を有していてもよい炭素数４~２１のアロイル基、置換基を有していてもよい炭素数３~２０のアリールスルホニル基または置換基を有していてもよい炭素数１~２０のアルキルスルホニル基を表す。）
［５］上記含硫黄芳香族化合物が、上記高分子電解質１００重量部に対して０．０１~３０重量部含有されることを特徴とする［１］~［４］のいずれかに記載の高分子電解質組成物。
［６］上記高分子電解質が芳香族炭化水素系高分子電解質であることを特徴とする特徴とする［１］~［５］のいずれかに記載の高分子電解質組成物。
［７］上記高分子電解質がフッ素系高分子電解質であることを特徴とする特徴とする［１］~［５］のいずれかに記載の高分子電解質組成物。
［８］［１］~［７］のいずれかに記載の高分子電解質組成物を含有することを特徴とする高分子電解質膜。
［９］［１］~［７］のいずれかに記載の高分子電解質組成物と、触媒成分とを含有することを特徴とする触媒組成物。
［１０］［８］に記載の高分子電解質膜および［９］に記載の触媒組成物からなる群より選ばれる１種以上を有することを特徴とする膜電極接合体。
［１１］［１０］に記載の膜電極接合体を有することを特徴とする固体高分子形燃料電池。 An object of the present invention is to provide a polymer electrolyte composition from which a polymer electrolyte membrane realizing a fuel cell with good long-term stability is obtained, a fuel cell member using the polymer electrolyte composition, and a solid excellent in long-term stability The object is to provide a polymer fuel cell.
The present invention provides the following [1] to [11].
[1] A polymer electrolyte composition comprising one or more sulfur-containing aromatic compounds selected from the group consisting of the following sulfur-containing aromatic compounds [A] to [D] and a polymer electrolyte.
Sulfur-containing aromatic compound [A]: A sulfur-containing aromatic compound represented by the following formula (1).
Figure JPOXMLDOC01-appb-I000007
(In Formula (1), Y 1 represents a divalent group containing a sulfur atom. C 1 to C 4 each represents a carbon atom. Ring Ar 01 contains C 1 and C 2 and has a substituent. An aromatic ring having 4 to 50 carbon atoms which may be optionally substituted, and ring Ar 02 represents an aromatic ring having 4 to 50 carbon atoms which may have a substituent, including C 3 and C 4. The substituent that 01 may have and the substituent which Ar 02 may have are a hydroxyl group, a halogeno group, a cyano group, a carboxy group, a phosphono group, a sulfo group, a formyl group, a mercapto group, and a methyl group, respectively. An aryl group having 4 to 20 carbon atoms which may have a substituent, an aryloxy group having 4 to 20 carbon atoms which may have a substituent, and 4 carbon atoms which may have a substituent. ~ 20 arylthio group, optionally substituted aroyl group having 5 to 21 carbon atoms And one or more groups selected from the group consisting of optionally substituted arylsulfonyl groups having 4 to 20 carbon atoms, wherein X 1 and X 2 are the same or different and each represents a hydrogen atom, a hydroxyl group A halogeno group, a cyano group, a carboxy group, a phosphono group, a sulfo group, a formyl group, a mercapto group, a methyl group, an aryl group having 4 to 20 carbon atoms which may have a substituent, and a substituent. An aryloxy group having 4 to 20 carbon atoms, an arylthio group having 4 to 20 carbon atoms which may have a substituent, an aroyl group having 5 to 21 carbon atoms which may have a substituent, or a substituent Represents an arylsulfonyl group having 4 to 20 carbon atoms which may have
Sulfur-containing aromatic compound [B]: A sulfur-containing aromatic compound represented by the following formula (2).
Figure JPOXMLDOC01-appb-I000008
(In formula (2), Y 1 has the same meaning as above. Z 1 represents a direct bond or a divalent group represented by any of the following formulas (2-1) to (2-9). C Each of 5 to C 8 represents a carbon atom, and ring Ar 03 represents an aromatic ring having 4 to 50 carbon atoms which may have a substituent, including C 5 and C 6. Ring Ar 04 represents C It represents an aromatic ring having 4 to 50 carbon atoms which contains 7 and C 8 and may have a substituent.
Figure JPOXMLDOC01-appb-I000009
(In the formulas (2-1) to (2-9), E 1 represents a hydrogen atom, a hydroxyl group, a methyl group, a methoxy group, or an aromatic group having 4 to 50 carbon atoms.)
Sulfur-containing aromatic compound [C]: Sulfur-containing aromatic compound represented by the following formula (3).
Figure JPOXMLDOC01-appb-I000010
(In Formula (3), Y 1 and Z 1 have the same meanings as above. C 9 to C 12 each represent a carbon atom. X 3 to X 6 are the same or different, and each represents a hydrogen atom, a hydroxyl group, A halogeno group, a cyano group, a carboxy group, a phosphono group, a sulfo group, a formyl group, a mercapto group, an optionally substituted alkyl group having 1 to 20 carbon atoms, and an optionally substituted carbon number An alkoxy group having 1 to 20 carbon atoms, an alkylthio group having 1 to 20 carbon atoms which may have a substituent, an aryl group having 3 to 20 carbon atoms which may have a substituent, and a substituent; An aryloxy group having 3 to 20 carbon atoms, an arylthio group having 3 to 20 carbon atoms which may have a substituent, an acyl group having 2 to 21 carbon atoms which may have a substituent, and a substituent An aroyl group having 4 to 21 carbon atoms, which may have a substituent If .Z 1 representing the optionally also be C 3-20 arylsulfonyl group, or a substituent and 1 carbon atoms which may have a 20 alkylsulfonyl group possessed a direct bond, X 4 and X 5 May be bonded to each other to form a ring.)
Sulfur-containing aromatic compound [D]: Sulfur-containing aromatic compound represented by the following formula (4).
Figure JPOXMLDOC01-appb-I000011
(In Formula (4), Y 1 and Z 1 are as defined above. C 13 to C 16 each represent a carbon atom. Ring Ar 05 contains C 15 and C 16 and has a substituent. Represents an aromatic ring having 4 to 50 carbon atoms, X 7 and X 8 are the same or different and each represents a hydrogen atom, a hydroxyl group, a halogeno group, a cyano group, a carboxy group, a phosphono group, a sulfo group, a formyl group, A mercapto group, an optionally substituted alkyl group having 1 to 20 carbon atoms, an optionally substituted alkoxy group having 1 to 20 carbon atoms, and an optionally substituted carbon number An alkylthio group having 1 to 20 carbon atoms, an aryl group having 3 to 20 carbon atoms which may have a substituent, an aryloxy group having 3 to 20 carbon atoms which may have a substituent, and a substituent; May have an arylthio group having 3 to 20 carbon atoms and a substituent An optionally substituted acyl group having 2 to 21 carbon atoms, an optionally substituted aroyl group having 4 to 21 carbon atoms, an optionally substituted arylsulfonyl group having 3 to 20 carbon atoms, or a substituent. Represents an alkylsulfonyl group having 1 to 20 carbon atoms which may have a group.)
[2] The sulfur-containing aromatic compound contained in the polymer electrolyte composition is one or more sulfur-containing aromatic compounds selected from the group consisting of sulfur-containing aromatic compounds [B] to [D]. The polymer electrolyte composition according to [1], which is characterized in that
[3] The polymer electrolyte composition according to [1] or [2], wherein Y 1 is a sulfur atom or a sulfinyl group.
[4] The polymer electrolyte composition according to any one of [1] to [3], wherein the sulfur-containing aromatic compound [B] is represented by the following formula (6).
Figure JPOXMLDOC01-appb-I000012
(In Formula (6), Y 1 and Z 1 are as defined above. R 01 to R 08 are the same or different, and each represents a hydrogen atom, a hydroxyl group, a halogeno group, a cyano group, a carboxy group, a phosphono group, A sulfo group, a formyl group, a mercapto group, an optionally substituted alkyl group having 1 to 20 carbon atoms, an optionally substituted alkoxy group having 1 to 20 carbon atoms, and a substituent. An optionally substituted alkylthio group having 1 to 20 carbon atoms, an aryl group having 3 to 20 carbon atoms which may have a substituent, an aryloxy group having 3 to 20 carbon atoms which may have a substituent, An arylthio group having 3 to 20 carbon atoms which may have a substituent, an acyl group having 2 to 21 carbon atoms which may have a substituent, and 4 to 21 carbon atoms which may have a substituent. An aroyl group having 3 to 20 carbon atoms which may have a substituent Have a Rusuruhoniru group or substituent represents an alkylsulfonyl group having 1 to 20 carbon atoms.)
[5] The high sulfur according to any one of [1] to [4], wherein the sulfur-containing aromatic compound is contained in an amount of 0.01 to 30 parts by weight with respect to 100 parts by weight of the polymer electrolyte. Molecular electrolyte composition.
[6] The polymer electrolyte composition as described in any one of [1] to [5], wherein the polymer electrolyte is an aromatic hydrocarbon polymer electrolyte.
[7] The polymer electrolyte composition as described in any one of [1] to [5], wherein the polymer electrolyte is a fluorine-based polymer electrolyte.
[8] A polymer electrolyte membrane comprising the polymer electrolyte composition according to any one of [1] to [7].
[9] A catalyst composition comprising the polymer electrolyte composition according to any one of [1] to [7] and a catalyst component.
[10] A membrane / electrode assembly comprising at least one selected from the group consisting of the polymer electrolyte membrane according to [8] and the catalyst composition according to [9].
[11] A polymer electrolyte fuel cell comprising the membrane electrode assembly according to [10].
　以下、本発明の高分子電解質組成物に係る好適な実施態様について具体的に説明する。本発明の電解質組成物は、下記含硫黄芳香族化合物［Ａ］~［Ｄ］からなる群より選ばれる一種以上の含硫黄芳香族化合物と高分子電解質とを含有することを特徴とする。
　まず、含硫黄芳香族化合物［Ａ］について説明する。
　含硫黄芳香族化合物［Ａ］：下記式（１）で表される含硫黄芳香族化合物。
Figure JPOXMLDOC01-appb-I000013
（式（１）中、Ｙ１は硫黄原子を含む２価の基を表す。Ｃ１~Ｃ４はそれぞれ炭素原子を表す。環Ａｒ０１は、Ｃ１およびＣ２を含み、置換基を有していてもよい炭素数４~５０の芳香環を表す。環Ａｒ０２は、Ｃ３およびＣ４を含み、置換基を有していてもよい炭素数４~５０の芳香環を表す。Ａｒ０１が有していてもよい置換基およびＡｒ０２が有していてもよい置換基はそれぞれ、水酸基、ハロゲノ基、シアノ基、カルボキシ基、ホスホノ基、スルホ基、ホルミル基、メルカプト基、メチル基、置換基を有していてもよい炭素数４~２０のアリール基、置換基を有していてもよい炭素数４~２０のアリールオキシ基、置換基を有していてもよい炭素数４~２０のアリールチオ基、置換基を有していてもよい炭素数５~２１のアロイル基および置換基を有していてもよい炭素数４~２０のアリールスルホニル基からなる群より選ばれる１種以上の基である。Ｘ１およびＸ２は、それぞれ同一または相異なり、水素原子、水酸基、ハロゲノ基、シアノ基、カルボキシ基、ホスホノ基、スルホ基、ホルミル基、メルカプト基、メチル基、置換基を有していてもよい炭素数４~２０のアリール基、置換基を有していてもよい炭素数４~２０のアリールオキシ基、置換基を有していてもよい炭素数４~２０のアリールチオ基、置換基を有していてもよい炭素数５~２１のアロイル基または置換基を有していてもよい炭素数４~２０のアリールスルホニル基を表す。）
　上記式（１）中、Ｙ１は硫黄原子を含む２価の基を表す。Ｙ１として、好ましくは、２価または４価の硫黄原子を含む２価の基であり、より好ましくは、硫黄原子（−Ｓ−で示される基）、スルフィニル基（−ＳＯ−で示される基）があげられ、さらに好ましくは硫黄原子である。
　上記式（１）中、Ｃ１~Ｃ４は炭素原子を表す。Ｃ１−Ｃ２結合およびＣ３−Ｃ４結合は、それぞれ、芳香環中の炭素—炭素結合である。
　環Ａｒ０１は、Ｃ１およびＣ２を含み、置換基を有していてもよい炭素数４~５０の芳香環を表す。環Ａｒ０２は、Ｃ３およびＣ４を含み、置換基を有していてもよい炭素数４~５０の芳香環を表す。該芳香環の好ましい炭素数としては、４~３０であり、より好ましくは４~２５であり、特に好ましくは６~２０である。
　上記の炭素数４~５０の芳香環として、ベンゼン、ジフェニルエーテル、ジフェニルスルフィド、ベンゾフェノン、ビフェニル、などの単環性芳香環、ビフェニレン、インダセン、アセナフチレン、フルオレン、フェナレン、フェナントレン、アントラセン、フルオランテン、トリフェニレン、ピレン、ナフタセン、ペリレンなどの縮環系芳香環、フラン、ベンゾフラン、ジベンゾフランなどのヘテロ原子を環内に含む芳香環などがあげられる。
　上記炭素数４~５０の芳香環は置換基を有してもよく、該置換基は、水酸基、ハロゲノ基、シアノ基、カルボキシ基、ホスホノ基、スルホ基、ホルミル基、メルカプト基、メチル基、置換基を有していてもよい炭素数４~２０のアリール基、置換基を有していてもよい炭素数４~２０のアリールオキシ基、置換基を有していてもよい炭素数４~２０のアリールチオ基、置換基を有していてもよい炭素数５~２１のアロイル基、置換基を有していてもよい炭素数４~２０のアリールスルホニル基から選ばれる基である。
　上記炭素数４~５０の芳香環上の置換基として好ましくは、ハロゲノ基、シアノ基、カルボキシ基、ホスホノ基、スルホ基、ホルミル基、メルカプト基、置換基を有していてもよい炭素数４~２０のアリール基、置換基を有していてもよい炭素数４~２０のアリールオキシ基、置換基を有していてもよい炭素数４~２０のアリールチオ基、置換基を有していてもよい炭素数５~２１のアロイル基および置換基を有していてもよい炭素数４~２０のアリールスルホニル基から選ばれる基であり、より好ましくは、シアノ基、カルボキシ基、ホスホノ基、スルホ基、ホルミル基、置換基を有していてもよい炭素数４~２０のアリール基、置換基を有していてもよい炭素数４~２０のアリールオキシ基、置換基を有していてもよい炭素数４~２０のアリールチオ基、置換基を有していてもよい炭素数５~２１のアロイル基、置換基を有していてもよい炭素数４~２０のアリールスルホニル基から選ばれる基であり、よりさらに好ましくは、シアノ基、カルボキシ基、置換基を有していてもよい炭素数４~２０のアリール基、置換基を有していてもよい炭素数４~２０のアリールオキシ基、置換基を有していてもよい炭素数４~２０のアリールチオ基、置換基を有していてもよい炭素数５~２１のアロイル基、置換基を有していてもよい炭素数４~２０のアリールスルホニル基から選ばれる基であり、特に好ましくは、置換基を有していてもよい炭素数４~２０のアリール基、置換基を有していてもよい炭素数４~２０のアリールチオ基、置換基を有していてもよい炭素数５~２１のアロイル基、置換基を有していてもよい炭素数４~２０のアリールスルホニル基から選ばれる基である。
　上記Ｘ１およびＸ２は、それぞれ独立に水素原子、水酸基、ハロゲノ基、シアノ基、カルボキシ基、ホスホノ基、スルホ基、ホルミル基、メルカプト基、メチル基、置換基を有していてもよい炭素数４~２０のアリール基、置換基を有していてもよい炭素数４~２０のアリールオキシ基、置換基を有していてもよい炭素数４~２０のアリールチオ基、置換基を有していてもよい炭素数５~２１のアロイル基または置換基を有していてもよい炭素数４~２０のアリールスルホニル基である。好ましくは、水素原子、ハロゲノ基、シアノ基、カルボキシ基、ホスホノ基、スルホ基、ホルミル基、メルカプト基、置換基を有していてもよい炭素数４~２０のアリール基、置換基を有していてもよい炭素数４~２０のアリールオキシ基、置換基を有していてもよい炭素数４~２０のアリールチオ基、置換基を有していてもよい炭素数５~２１のアロイル基、置換基を有していてもよい炭素数４~２０のアリールスルホニル基であり、より好ましくは、水素原子、シアノ基、カルボキシ基、ホスホノ基、スルホ基、ホルミル基、置換基を有していてもよい炭素数４~２０のアリール基、置換基を有していてもよい炭素数４~２０のアリールオキシ基、置換基を有していてもよい炭素数４~２０のアリールチオ基、置換基を有していてもよい炭素数５~２１のアロイル基、置換基を有していてもよい炭素数４~２０のアリールスルホニル基であり、よりさらに好ましくは、水素原子、シアノ基、カルボキシ基、置換基を有していてもよい炭素数４~２０のアリール基、置換基を有していてもよい炭素数４~２０のアリールオキシ基、置換基を有していてもよい炭素数４~２０のアリールチオ基、置換基を有していてもよい炭素数５~２１のアロイル基、置換基を有していてもよい炭素数４~２０のアリールスルホニル基であり、特に好ましくは、水素原子、置換基を有していてもよい炭素数４~２０のアリール基、置換基を有していてもよい炭素数４~２０のアリールチオ基、置換基を有していてもよい炭素数５~２１のアロイル基、置換基を有していてもよい炭素数４~２０のアリールスルホニル基である。
　上記のハロゲノ基としては、フルオロ基、クロロ基、ブロモ基、ヨード基があげられ、好ましくはフルオロ基である。
　上記の置換基を有していてもよい炭素数４~２０のアリール基として、フェニル、ｏ−メチルフェニル、ｍ−メチルフェニル、ｐ−メチルフェニル、ｏ−フェノキシフェニル、ｍ−フェノキシフェニル、ｐ−フェノキシフェニル、ｏ−クロロフェニル、ｍ−クロロフェニル、ｐ−クロロフェニル、ビフェニルなどの単環性アリール基、１−ナフチル、２−ナフチル、１−アントラシル、２−アントラシル、４−アントラシル基などの縮環系アリール基、２−チエニル、３−チエニル、２−フリル、３−フリル基などのヘテロアリール基などがあげられる。
　上記の置換基を有していてもよい炭素数４~２０のアリールオキシ基として、前述の置換基を有していてもよい炭素数４~２０のアリール基の例示の群より選ばれるアリール基で水酸基の水素原子を置換した基などがあげられる。
　上記の置換基を有していてもよい炭素数４~２０のアリールチオ基として、前述の置換基を有していてもよい炭素数４~２０のアリール基の例示の群より選ばれるアリール基でメルカプト基の水素原子を置換した基などがあげられる。
　上記の置換基を有していてもよい炭素数５~２１のアロイル基として、前述の置換基を有していてもよい炭素数４~２０のアリール基の例示の群より選ばれるアリール基でホルミル基の水素原子を置換した基などがあげられる。
　上記の置換基を有していてもよい炭素数４~２０のアリールスルホニル基として、フェニルスルホニル、ｏ−メチルフェニルスルホニル、ｍ−メチルフェニルスルホニル、ｐ−メチルフェニルスルホニル、ｏ−フェノキシフェニルスルホニル、ｍ−フェノキシフェニルスルホニル、ｐ−フェノキシフェニルスルホニル、ｏ−クロロフェニルスルホニル、ｍ−クロロフェニルスルホニル、ｐ−クロロフェニルスルホニルなどの単環性アリールスルホニル基、１−ナフチルスルホニル、２−ナフチルスルホニル、１−アントラシルスルホニル、２−アントラシルスルホニル、４−アントラシルスルホニル基などの縮環系アリールスルホニル基、２−チエニルスルホニル、３−チエニルスルホニルなどのヘテロアリールスルホニル基があげられる。
　上記式（１）で表される含硫黄芳香族化合物［Ａ］の例としては、フェニルスルフィド、ビス（２−ヒドロキシ−５−クロロフェニル）スルフィド、４−ベンゾイル　４’−メチルジフェニル　スルフィド、ビス（４−ヒドロキシ−３−メチルフェニル）スルフィド、ビス（４−メタクリロイルチオフェニル）スルフィド、ビス（４−ヒドロキシフェニル）スルフィド、フェニルｐ−トリルスルフィド、５，５’−チオジサリチル酸、２，２’−チオビス（４，６−ジクロロフェノール）二ナトリウム、２，２’−チオビス（４，６−ジクロロフェノール）、４，４’−チオビスベンゼンチオール４−クロロフェニル　スルホキシド、ジフェニル　スルホキシド、ｐ−トリルスルホキシド、１、１’−チオビス（２−ナフトール）、１、１’−チオビス（２−ナフタレン）、ビス（２−ナフチル）スルホキシドなどをあげることができる。
　次に、含硫黄芳香族化合物［Ｂ］について説明する。
　含硫黄芳香族化合物［Ｂ］：下記式（２）で表される含硫黄芳香族化合物。
Figure JPOXMLDOC01-appb-I000014
（式（２）中、Ｙ１は上記と同義である。Ｚ１は、直接結合、下記式（２−１）~（２−９）のいずれかで示される２価の基を表す。Ｃ５~Ｃ８はそれぞれ炭素原子を表す。環Ａｒ０３は、Ｃ５およびＣ６を含み、置換基を有していてもよい炭素数４~５０の芳香環を表す。環Ａｒ０４は、Ｃ７およびＣ８を含み、置換基を有していてもよい炭素数４~５０の芳香環を表す。
Figure JPOXMLDOC01-appb-I000015
（式（２−１）~（２−９）中、Ｅ１は水素原子、水酸基、メチル基、メトキシ基または炭素数４~５０の芳香族基を表す。））
　上記式（２）中、Ｙ１は式（１）におけるＹ１と同義であり、その好ましい例も式（１）におけるＹ１の具体例、好ましい例と同様である。
　上記式（２）中、Ｃ５~Ｃ８は炭素原子を表す。Ｃ５−Ｃ８結合およびＣ７−Ｃ８結合は、それぞれ、芳香環基中の炭素—炭素結合である。
　環Ａｒ０３は、Ｃ５およびＣ６を含み、置換基を有していてもよい炭素数４~５０の芳香環を表す。環Ａｒ０４は、Ｃ７およびＣ８を含み、置換基を有していてもよい炭素数４~５０の芳香環を表す。該芳香環の好ましい炭素数としては、４~３０であり、より好ましくは４~２５であり、特に好ましくは６~２０である。
　上記の炭素数４~５０の芳香環として、ベンゼン、ジフェニルエーテル、ジフェニルスルフィド、ベンゾフェノン、ビフェニル、などの単環性芳香環、ビフェニレン、インダセン、アセナフチレン、フルオレン、フェナレン、フェナントレン、アントラセン、フルオランテン、トリフェニレン、ピレン、ナフタセン、ペリレンなどの縮環系芳香環、フラン、ベンゾフラン、ジベンゾフラン、チオフェン、ベンゾチオフェン、ジベンゾチオフェンなどのヘテロ原子を環内に含む芳香環などがあげられる。
　上記炭素数４~５０の芳香環は置換基を有してもよく、該置換基としては、例えば、水酸基、ハロゲノ基、シアノ基、カルボキシ基、ホスホノ基、スルホ基、ホルミル基、メルカプト基、置換基を有していてもよい炭素数１~２０のアルキル基、置換基を有していてもよい炭素数１~２０のアルコキシ基、置換基を有していてもよい炭素数１~２０のアルキルチオ基、置換基を有していてもよい炭素数３~２０のアリール基、置換基を有していてもよい炭素数３~２０のアリールオキシ基、置換基を有していてもよい炭素数３~２０のアリールチオ基、置換基を有していてもよい炭素数２~２１のアシル基、置換基を有していてもよい炭素数４~２１のアロイル基、置換基を有していてもよい炭素数３~２０のアリールスルホニル基および置換基を有していてもよい炭素数１~２０のアルキルスルホニル基から選ばれる基である。非脂肪族炭化水素系高分子電解質への分散、相溶性を向上させ、酸化防止剤自体の耐久性を高めるために、ここでの上記炭素数４~５０の芳香環上の置換基として好ましくは、ハロゲノ基、シアノ基、カルボキシ基、ホスホノ基、スルホ基、ホルミル基、メルカプト基、置換基を有していてもよい炭素数３~２０のアリール基、置換基を有していてもよい炭素数３~２０のアリールオキシ基、置換基を有していてもよい炭素数３~２０のアリールチオ基、置換基を有していてもよい炭素数４~２１のアロイル基、置換基を有していてもよい炭素数３~２０のアリールスルホニル基があげられ、より好ましくは、シアノ基、カルボキシ基、ホルミル基、置換基を有していてもよい炭素数３~２０のアリール基、置換基を有していてもよい炭素数３~２０のアリールオキシ基、置換基を有していてもよい炭素数３~２０のアリールチオ基、置換基を有していてもよい炭素数４~２１のアロイル基、置換基を有していてもよい炭素数３~２０のアリールスルホニル基があげられ、特に好ましくは、置換基を有していてもよい炭素数３~２０のアリール基、置換基を有していてもよい炭素数３~２０のアリールオキシ基、置換基を有していてもよい炭素数３~２０のアリールチオ基、置換基を有していてもよい炭素数４~２１のアロイル基、置換基を有していてもよい炭素数３~２０のアリールスルホニル基があげられる。
　ハロゲノ基としては、フルオロ基、クロロ基、ブロモ基、ヨード基があげられ、好ましくはフルオロ基があげられる。
　上記の置換基を有していてもよい炭素数１~２０のアルキル基として、直鎖状または分岐鎖状アルキル基があげられる。好ましい炭素数としては１~６であり、より好ましくは１~４であり、よりさらに好ましくは１~４であり、特に好ましくは１である。具体的には、メチル、エチル、プロピル、イソプロピル、ブチル、イソブチル、ｓｅｃ−ブチル、ｔ−ブチル、ペンチル、ヘキシル、ヘプチル、オクチル、デシル、トリフルオロメチル基などがあげられる。
　上記の置換基を有していてもよい炭素数１~２０のアルコキシ基として、前述の置換基を有していてもよい炭素数１~２０のアルキル基の例示の群より選ばれるアルキル基で水酸基の水素原子を置換した基などがあげられる。その好ましい例は前述のアルキル基の好ましい例示の群より選ばれるアルキル基で水酸基の水素原子を置換した基などがあげられる。
　上記の置換基を有していてもよい炭素数１~２０のアルキルチオ基として、前述の置換基を有していてもよい炭素数１~２０のアルキル基の例示の群より選ばれるアルキル基でメルカプト基の水素原子を置換した基があげられる。その好ましい例は前述のアルキル基の好ましい例示の群より選ばれるアルキル基でメルカプト基の水素原子を置換した基などがあげられる。
　上記の置換基を有していてもよい炭素数３~２０のアリール基として、フェニル、ｏ−メチルフェニル、ｍ−メチルフェニル、ｐ−メチルフェニル、ｏ−メトキシフェニル、ｍ−メトキシフェニル、ｐ−メトキシフェニル、ｏ−フェノキシフェニル、ｍ−フェノキシフェニル、ｐ−フェノキシフェニル、ｏ−クロロフェニル、ｍ−クロロフェニル、ｐ−クロロフェニル、ビフェニル基などの単環性アリール基、１−ナフチル、２−ナフチル、１−アントラシル、２−アントラシル、４−アントラシル基などの縮環系アリール基、２−チエニル、３−チエニル、２−フリル、３−フリル基などのヘテロアリール基などがあげられる。
　上記の置換基を有していてもよい炭素数３~２０のアリールオキシ基として、前述の置換基を有していてもよい炭素数３~２０のアリール基の例示の群より選ばれるアリール基で水酸基の水素原子を置換した基などがあげられる。その好ましい例は前述のアリール基の好ましい例示の群より選ばれるアリール基で水酸基の水素原子を置換した基などがあげられる。
　上記の置換基を有していてもよい炭素数３~２０のアリールチオ基として、前述の置換基を有していてもよい炭素数３~２０のアリール基の例示の群より選ばれるアリール基でメルカプト基の水素原子を置換した基などがあげられる。その好ましい例は前述のアリール基の好ましい例示の群より選ばれるアリール基でメルカプト基の水素原子を置換した基などがあげられる。
　上記の置換基を有していてもよい炭素数２~２１のアシル基として、前述の置換基を有していてもよい炭素数１~２０のアルキル基の例示の群より選ばれるアルキル基でホルミル基の水素原子を置換した基があげられる。その好ましい例は前述のアルキル基の好ましい例示の群より選ばれるアルキル基でホルミル基の水素原子を置換した基などがあげられる。
　上記の置換基を有していてもよい炭素数４~２１のアロイル基として、前述の置換基を有していてもよい炭素数３~２０のアリール基の例示の群より選ばれるアリール基でホルミル基の水素原子を置換した基などがあげられる。その好ましい例は前述のアリール基の好ましい例示の群より選ばれるアリール基でホルミル基の水素原子を置換した基などがあげられる。
　上記の置換基を有していてもよい炭素数３~２０のアリールスルホニル基として、フェニルスルホニル、ｏ−メチルフェニルスルホニル、ｍ−メチルフェニルスルホニル、ｐ−メチルフェニルスルホニル、ｏ−メトキシフェニルスルホニル、ｍ−メトキシフェニルスルホニル、ｐ−メトキシフェニルスルホニル、ｏ−フェノキシフェニルスルホニル、ｍ−フェノキシフェニルスルホニル、ｐ−フェノキシフェニルスルホニル、ｏ−クロロフェニルスルホニル、ｍ−クロロフェニルスルホニル、ｐ−クロロフェニルスルホニル、ビフェニルスルホニル基などの単環性アリールスルホニル基、１−ナフチルスルホニル、２−ナフチルスルホニル、１−アントラシルスルホニル、２−アントラシルスルホニル、４−アントラシルスルホニル基などの縮環系アリールスルホニル基、２−チエニルスルホニル、３−チエニルスルホニル、２−フリルスルホニル、３−フリルスルホニル基などのヘテロアリールスルホニル基があげられる。
　上記の置換基を有していてもよい炭素数１~２０のアルキルスルホニル基において、好ましい炭素数としては１~６であり、より好ましくは１~４であり、よりさらに好ましくは１~４であり、特に好ましくは１である。具体的には、メチルスルホニル、エチルスルホニル、プロピルスルホニル、イソプロピルスルホニル、ブチルスルホニル、イソブチルスルホニル、ｓｅｃ−ブチルスルホニル、ｔ−ブチルスルホニル、ペンチルスルホニル、ヘキシルスルホニル、ヘプチルスルホニル、オクチルスルホニル、デシルスルホニル基などがあげられる。
　上記式（２）中、Ｚ１は、直接結合、上記式（２−１）~（２−９）のいずれかで示される２価の基を表す。好ましくは直接結合、（２−１）~（２−３）、（２−７）~（２−９）であり、より好ましくは直接結合、（２−２）、（２−３）、（２−７）、（２−８）であり、特に好ましくは直接結合、（２−２）、（２−３）、（２−７）である。
　上記式（２−１）~（２−９）中、Ｅ１は水素原子、水酸基、メチル基、メトキシ基または置換基を有してもよい炭素数４~５０の芳香族基を示し、好ましくは置換基を有してもよい炭素数４~５０の１価の芳香族基である。該芳香族基の炭素数としては好ましくは４~３０であり、より好ましくは４~２０であり、特に好ましくは４~１２である。
　Ｅ１で示される炭素数４~５０の芳香族基としては、ベンゼン、トルエン、メトキシベンゼン、ビフェニル、ナフタレン、アントラセン、フルオレン、フラン、ベンゾフラン、ジベンゾフラン、チオフェン、ベンゾチオフェン、ジベンゾチオフェン、チアントレン、フェノキサチインなどの芳香族化合物に由来する芳香族基があげられ、Ｅ１で示される炭素数４~５０の１価の芳香族基としては、ベンゼン、トルエン、メトキシベンゼン、ビフェニル、ナフタレン、アントラセン、フルオレン、フラン、ベンゾフラン、ジベンゾフラン、チオフェン、ベンゾチオフェン、ジベンゾチオフェン、チアントレン、フェノキサチインから芳香環上の水素原子を一つ取り去って得られる基をあげることができる。
　該炭素数４~５０の１価の芳香族基は、置換基を有してもよく、水酸基、ハロゲノ基、シアノ基、カルボキシ基、ホスホノ基、スルホ基、ホルミル基、メルカプト基、置換基を有していてもよい炭素数１~２０のアルキル基、置換基を有していてもよい炭素数１~２０のアルコキシ基、置換基を有していてもよい炭素数１~２０のアルキルチオ基、置換基を有していてもよい炭素数３~２０のアリール基、置換基を有していてもよい炭素数３~２０のアリールオキシ基、置換基を有していてもよい炭素数３~２０のアリールチオ基、置換基を有していてもよい炭素数２~２１のアシル基、置換基を有していてもよい炭素数４~２１のアロイル基、置換基を有していてもよい炭素数３~２０のアリールスルホニル基および置換基を有していてもよい炭素数１~２０のアルキルスルホニル基から選ばれる基があげられる。非脂肪族炭化水素系高分子電解質への分散、相溶性を向上させ、酸化防止剤自体の耐久性を高めるために、該炭素数４~５０の１価の芳香族基上の置換基として好ましくは、ハロゲノ基、シアノ基、カルボキシ基、ホスホノ基、スルホ基、ホルミル基、メルカプト基、置換基を有していてもよい炭素数３~２０のアリール基、置換基を有していてもよい炭素数３~２０のアリールオキシ基、置換基を有していてもよい炭素数３~２０のアリールチオ基、置換基を有していてもよい炭素数４~２１のアロイル基、置換基を有していてもよい炭素数３~２０のアリールスルホニル基があげられ、より好ましくは、シアノ基、カルボキシ基、ホルミル基、置換基を有していてもよい炭素数３~２０のアリール基、置換基を有していてもよい炭素数３~２０のアリールオキシ基、置換基を有していてもよい炭素数３~２０のアリールチオ基、置換基を有していてもよい炭素数４~２１のアロイル基、置換基を有していてもよい炭素数３~２０のアリールスルホニル基があげられ、特に好ましくは、置換基を有していてもよい炭素数３~２０のアリール基、置換基を有していてもよい炭素数３~２０のアリールオキシ基、置換基を有していてもよい炭素数３~２０のアリールチオ基、置換基を有していてもよい炭素数４~２１のアロイル基、置換基を有していてもよい炭素数３~２０のアリールスルホニル基があげられる。
　ここでのハロゲノ基、置換基を有していてもよい炭素数１~２０のアルキル基、置換基を有していてもよい炭素数１~２０のアルコキシ基、置換基を有していてもよい炭素数１~２０のアルキルチオ基、置換基を有していてもよい炭素数３~２０のアリール基、置換基を有していてもよい炭素数３~２０のアリールオキシ基、置換基を有していてもよい炭素数３~２０のアリールチオ基、置換基を有していてもよい炭素数２~２１のアシル基、置換基を有していてもよい炭素数４~２１のアロイル基、置換基を有していてもよい炭素数３~２０のアリールスルホニル基および置換基を有していてもよい炭素数１~２０のアルキルスルホニル基から選ばれる基の具体例およびその好ましい例としては、上記環Ａｒ０３または環Ａｒ０４における炭素数４~５０の芳香環上の置換基と同じものがあげられる。
　上記式（２）で表される含硫黄芳香族化合物［Ｂ］の具体例としては、下記（Ｂ−００１）~（Ｂ−０１８）で表される化合物をあげることができる。
Figure JPOXMLDOC01-appb-I000016
　次に、含硫黄芳香族化合物［Ｃ］について説明する。
含硫黄芳香族化合物［Ｃ］：下記式（３）で表される含硫黄芳香族化合物。
Figure JPOXMLDOC01-appb-I000017
（式（３）中、Ｙ１およびＺ１はそれぞれ上記と同義である。Ｃ９~Ｃ１２はそれぞれ炭素原子を表す。Ｘ３~Ｘ６は、それぞれ同一または相異なり、水素原子、水酸基、ハロゲノ基、シアノ基、カルボキシ基、ホスホノ基、スルホ基、ホルミル基、メルカプト基、置換基を有していてもよい炭素数１~２０のアルキル基、置換基を有していてもよい炭素数１~２０のアルコキシ基、置換基を有していてもよい炭素数１~２０のアルキルチオ基、置換基を有していてもよい炭素数３~２０のアリール基、置換基を有していてもよい炭素数３~２０のアリールオキシ基、置換基を有していてもよい炭素数３~２０のアリールチオ基、置換基を有していてもよい炭素数２~２１のアシル基、置換基を有していてもよい炭素数４~２１のアロイル基、置換基を有していてもよい炭素数３~２０のアリールスルホニル基または置換基を有していてもよい炭素数１~２０のアルキルスルホニル基を表す。Ｚ１が直接結合の場合、Ｘ４およびＸ５は互いに結合することにより、Ｃ１０及びＣ１１を含む環を形成していてもよい。）
　式（３）中、Ｙ１およびＺ１は式（１）におけるＹ１および式（２）におけるＺ１と同義であり、その具体例、好ましい例も式（１）におけるＹ１および式（２）におけるＺ１の具体例、好ましい例と同様なものをあげることができる。
　上記式（３）中、Ｃ９~Ｃ１２は炭素原子を表す。Ｃ９−Ｃ１０結合およびＣ１１−Ｃ１２結合は、２重結合である。
　式（３）中、Ｘ３~Ｘ６は、それぞれ同一または相異なり、水素原子、水酸基、ハロゲノ基、シアノ基、カルボキシ基、ホスホノ基、スルホ基、ホルミル基、メルカプト基、置換基を有していてもよい炭素数１~２０のアルキル基、置換基を有していてもよい炭素数１~２０のアルコキシ基、置換基を有していてもよい炭素数１~２０のアルキルチオ基、置換基を有していてもよい炭素数３~２０のアリール基、置換基を有していてもよい炭素数３~２０のアリールオキシ基、置換基を有していてもよい炭素数３~２０のアリールチオ基、置換基を有していてもよい炭素数２~２１のアシル基、置換基を有していてもよい炭素数４~２１のアロイル基、置換基を有していてもよい炭素数３~２０のアリールスルホニル基または置換基を有していてもよい炭素数１~２０のアルキルスルホニル基を表す。
　Ｘ３~Ｘ６はそれぞれ、好ましくは、水素原子、水酸基、ハロゲノ基、シアノ基、カルボキシ基、ホスホノ基、スルホ基、ホルミル基、メルカプト基、置換基を有していてもよい炭素数３~２０のアリール基、置換基を有していてもよい炭素数３~２０のアリールオキシ基、置換基を有していてもよい炭素数３~２０のアリールチオ基、置換基を有していてもよい炭素数４~２１のアロイル基、置換基を有していてもよい炭素数３~２０のアリールスルホニル基であり、より好ましくは、水素原子、シアノ基、カルボキシ基、ホルミル基、置換基を有していてもよい炭素数３~２０のアリール基、置換基を有していてもよい炭素数３~２０のアリールオキシ基、置換基を有していてもよい炭素数３~２０のアリールチオ基、置換基を有していてもよい炭素数４~２１のアロイル基、置換基を有していてもよい炭素数３~２０のアリールスルホニル基であり、特に好ましくは、水素原子、置換基を有していてもよい炭素数３~２０のアリール基、置換基を有していてもよい炭素数３~２０のアリールオキシ基、置換基を有していてもよい炭素数３~２０のアリールチオ基、置換基を有していてもよい炭素数４~２１のアロイル基、置換基を有していてもよい炭素数３~２０のアリールスルホニル基である。
　ここでのハロゲノ基、置換基を有していてもよい炭素数１~２０のアルキル基、置換基を有していてもよい炭素数１~２０のアルコキシ基、置換基を有していてもよい炭素数１~２０のアルキルチオ基、置換基を有していてもよい炭素数３~２０のアリール基、置換基を有していてもよい炭素数３~２０のアリールオキシ基、置換基を有していてもよい炭素数３~２０のアリールチオ基、置換基を有していてもよい炭素数２~２１のアシル基、置換基を有していてもよい炭素数４~２１のアロイル基、置換基を有していてもよい炭素数３~２０のアリールスルホニル基および置換基を有していてもよい炭素数１~２０のアルキルスルホニル基から選ばれる基の具体例およびその好ましい例としては、上記環Ａｒ０３または環Ａｒ０４における炭素数４~５０の芳香環上の置換基の具体例およびその好ましい例と同じものがあげられる。
　また、Ｚ１が直接結合の場合、Ｘ４およびＸ５は互いに結合することにより、環を形成してもよい。該環としては、Ｃ１０およびＣ１１を含み、置換基を有していてもよい炭素数４~５０の環が好ましく、該環は芳香族性を有することが好ましい。より好ましくは置換基を有していてもよい炭素数６~２０の環があげられ、特に好ましくは置換基を有していてもよい炭素数６~１２の環があげられる。なお、ここでの芳香族性とは、モリソンボイド有機化学（中）第６版（東京化学同人）に記載のように、環状基の環内に４ｎ＋２（ｎは任意の整数を示す）個のπ電子を含むことである。
　Ｘ４およびＸ５が互いに結合することにより形成される環状基を下記式（５０１）の形で示すと、下記式（５０１−１）~（５０１−４）で表される基を該環状基として例示することができる。
Figure JPOXMLDOC01-appb-I000018
　該環状基上の置換基としては、水酸基、ハロゲノ基、シアノ基、カルボキシ基、ホスホノ基、スルホ基、ホルミル基、メルカプト基、置換基を有していてもよい炭素数１~２０のアルキル基、置換基を有していてもよい炭素数１~２０のアルコキシ基、置換基を有していてもよい炭素数１~２０のアルキルチオ基、置換基を有していてもよい炭素数３~２０のアリール基、置換基を有していてもよい炭素数３~２０のアリールオキシ基、置換基を有していてもよい炭素数３~２０のアリールチオ基、置換基を有していてもよい炭素数２~２１のアシル基、置換基を有していてもよい炭素数４~２１のアロイル基、置換基を有していてもよい炭素数３~２０のアリールスルホニル基または置換基を有していてもよい炭素数１~２０のアルキルスルホニル基から選ばれる基である。具体例およびその好ましい例は、上記Ａｒ０３またはＡｒ０４で表される炭素数４~５０の芳香環が有してもよい基の具体例およびその好ましい例と、同様なものをあげることができる。
　上記式（３）で表される含硫黄芳香族化合物［Ｃ］の具体例としては、下記（Ｃ−００１）~（Ｃ−０２１）などをあげることができる。
Figure JPOXMLDOC01-appb-I000019
Figure JPOXMLDOC01-appb-I000020
　次に、含硫黄芳香族化合物［Ｄ］について説明する。
含硫黄芳香族化合物［Ｄ］：下記式（４）で表される含硫黄芳香族化合物。
Figure JPOXMLDOC01-appb-I000021
（式（４）中、Ｙ１およびＺ１は上記と同義である。Ｃ１３~Ｃ１６はそれぞれ炭素原子を表す。環Ａｒ０５は、Ｃ１５およびＣ１６を含み、置換基を有していてもよい炭素数４~５０の芳香環を表す。Ｘ７およびＸ８は、それぞれ同一または相異なり、水素原子、水酸基、ハロゲノ基、シアノ基、カルボキシ基、ホスホノ基、スルホ基、ホルミル基、メルカプト基、置換基を有していてもよい炭素数１~２０のアルキル基、置換基を有していてもよい炭素数１~２０のアルコキシ基、置換基を有していてもよい炭素数１~２０のアルキルチオ基、置換基を有していてもよい炭素数３~２０のアリール基、置換基を有していてもよい炭素数３~２０のアリールオキシ基、置換基を有していてもよい炭素数３~２０のアリールチオ基、置換基を有していてもよい炭素数２~２１のアシル基、置換基を有していてもよい炭素数４~２１のアロイル基、置換基を有していてもよい炭素数３~２０のアリールスルホニル基または置換基を有していてもよい炭素数１~２０のアルキルスルホニル基を表す。）
　上記式（４）中、Ｙ１およびＺ１は式（１）におけるＹ１および式（２）におけるＺ１と同義であり、その具体例、好ましい例も式（１）におけるＹ１および式（２）におけるＺ１の具体例、好ましい例と同様なものをあげることができる。
　上記式（４）中、Ｃ１３~Ｃ１６は炭素原子を表す。Ｃ１３−Ｃ１４結合は、２重結合である。なお、Ｃ１５−Ｃ１６結合は、芳香環基中の炭素—炭素結合である。
　環Ａｒ０５は、Ｃ１５およびＣ１６を含み、置換基を有していてもよい炭素数４~５０の芳香環を表す。環Ａｒ０５の具体例およびその好ましい例は、上記の環Ａｒ０３または環Ａｒ０４の例と同様なものをあげることができる。
　上記炭素数４~５０の芳香環は置換基を有してもよく、該置換基としては、例えば、水酸基、ハロゲノ基、シアノ基、カルボキシ基、ホスホノ基、スルホ基、ホルミル基、メルカプト基、置換基を有していてもよい炭素数１~２０のアルキル基、置換基を有していてもよい炭素数１~２０のアルコキシ基、置換基を有していてもよい炭素数１~２０のアルキルチオ基、置換基を有していてもよい炭素数３~２０のアリール基、置換基を有していてもよい炭素数３~２０のアリールオキシ基、置換基を有していてもよい炭素数３~２０のアリールチオ基、置換基を有していてもよい炭素数２~２１のアシル基、置換基を有していてもよい炭素数４~２１のアロイル基、置換基を有していてもよい炭素数３~２０のアリールスルホニル基および置換基を有していてもよい炭素数１~２０のアルキルスルホニル基から選ばれる基である。具体例およびその好ましい例は、上記環Ａｒ０３または環Ａｒ０４における炭素数４~５０の芳香環が有してもよい基として説明したものと、同様なものをあげることができる。
　上記式（４）中、Ｘ７およびＸ８は、それぞれ同一または相異なり、水素原子、水酸基、ハロゲノ基、シアノ基、カルボキシ基、ホスホノ基、スルホ基、ホルミル基、メルカプト基、置換基を有していてもよい炭素数１~２０のアルキル基、置換基を有していてもよい炭素数１~２０のアルコキシ基、置換基を有していてもよい炭素数１~２０のアルキルチオ基、置換基を有していてもよい炭素数３~２０のアリール基、置換基を有していてもよい炭素数３~２０のアリールオキシ基、置換基を有していてもよい炭素数３~２０のアリールチオ基、置換基を有していてもよい炭素数２~２１のアシル基、置換基を有していてもよい炭素数４~２１のアロイル基、置換基を有していてもよい炭素数３~２０のアリールスルホニル基または置換基を有していてもよい炭素数１~２０のアルキルスルホニル基である。Ｘ７およびＸ８の具体例およびその好ましい例は、上記Ｘ３~Ｘ６と、同様なものをあげることができる。
　上記式（４）で表される含硫黄芳香族化合物［Ｄ］の具体例としては、下記（Ｄ−００１）~（Ｄ−００６）をあげることができる。
Figure JPOXMLDOC01-appb-I000022
　上記含硫黄芳香族化合物［Ａ］~［Ｄ］のうち、好ましくは含硫黄芳香族化合物［Ｂ］~［Ｄ］であり、より好ましくは含硫黄芳香族化合物［Ｂ］、［Ｄ］であり、特に好ましくは含硫黄芳香族化合物［Ｂ］である。
　好ましい含硫黄芳香族化合物［Ｂ］として、下記式（６）で表される含硫黄芳香族化合物をあげることができる。
Figure JPOXMLDOC01-appb-I000023
（式（６）中、Ｙ１およびＺ１は上記と同義である。Ｒ０１~Ｒ０８は、それぞれ同一または相異なり、水素原子、水酸基、ハロゲノ基、シアノ基、カルボキシ基、ホスホノ基、スルホ基、ホルミル基、メルカプト基、置換基を有していてもよい炭素数１~２０のアルキル基、置換基を有していてもよい炭素数１~２０のアルコキシ基、置換基を有していてもよい炭素数１~２０のアルキルチオ基、置換基を有していてもよい炭素数３~２０のアリール基、置換基を有していてもよい炭素数３~２０のアリールオキシ基、置換基を有していてもよい炭素数３~２０のアリールチオ基、置換基を有していてもよい炭素数２~２１のアシル基、置換基を有していてもよい炭素数４~２１のアロイル基、置換基を有していてもよい炭素数３~２０のアリールスルホニル基または置換基を有していてもよい炭素数１~２０のアルキルスルホニル基を表す。）
　上記式（６）中、Ｙ１およびＺ１は式（１）におけるＹ１および式（２）におけるＺ１と同義であり、その具体例、好ましい例も式（１）におけるＹ１および式（２）におけるＺ１の具体例、好ましい例と同様なものをあげることができる。
　上記式（６）中、Ｒ０１~Ｒ０８は、それぞれ同一または相異なり、水素原子、水酸基、ハロゲノ基、シアノ基、カルボキシ基、ホスホノ基、スルホ基、ホルミル基、メルカプト基、置換基を有していてもよい炭素数１~２０のアルキル基、置換基を有していてもよい炭素数１~２０のアルコキシ基、置換基を有していてもよい炭素数１~２０のアルキルチオ基、置換基を有していてもよい炭素数３~２０のアリール基、置換基を有していてもよい炭素数３~２０のアリールオキシ基、置換基を有していてもよい炭素数３~２０のアリールチオ基、置換基を有していてもよい炭素数２~２１のアシル基、置換基を有していてもよい炭素数４~２１のアロイル基、置換基を有していてもよい炭素数３~２０のアリールスルホニル基または置換基を有していてもよい炭素数１~２０のアルキルスルホニル基を表す。
　Ｒ０１~Ｒ０８は、好ましくは、水素原子、水酸基、ハロゲノ基、シアノ基、カルボキシ基、ホスホノ基、スルホ基、ホルミル基、メルカプト基、置換基を有していてもよい炭素数３~２０のアリール基、置換基を有していてもよい炭素数３~２０のアリールオキシ基、置換基を有していてもよい炭素数３~２０のアリールチオ基、置換基を有していてもよい炭素数４~２１のアロイル基、置換基を有していてもよい炭素数３~２０のアリールスルホニル基であり、より好ましくは、水素原子、シアノ基、カルボキシ基、ホルミル基、置換基を有していてもよい炭素数３~２０のアリール基、置換基を有していてもよい炭素数３~２０のアリールオキシ基、置換基を有していてもよい炭素数３~２０のアリールチオ基、置換基を有していてもよい炭素数４~２１のアロイル基、置換基を有していてもよい炭素数３~２０のアリールスルホニル基であり、特に好ましくは、水素原子、置換基を有していてもよい炭素数３~２０のアリール基、置換基を有していてもよい炭素数３~２０のアリールオキシ基、置換基を有していてもよい炭素数３~２０のアリールチオ基、置換基を有していてもよい炭素数４~２１のアロイル基、置換基を有していてもよい炭素数３~２０のアリールスルホニル基である。
　ここでの、ハロゲノ基、置換基を有していてもよい炭素数１~２０のアルキル基、置換基を有していてもよい炭素数１~２０のアルコキシ基、置換基を有していてもよい炭素数１~２０のアルキルチオ基、置換基を有していてもよい炭素数３~２０のアリール基、置換基を有していてもよい炭素数３~２０のアリールオキシ基、置換基を有していてもよい炭素数３~２０のアリールチオ基、置換基を有していてもよい炭素数２~２１のアシル基、置換基を有していてもよい炭素数４~２１のアロイル基、置換基を有していてもよい炭素数３~２０のアリールスルホニル基および置換基を有していてもよい炭素数１~２０のアルキルスルホニル基から選ばれる基の具体例およびその好ましい例としては、上記環Ａｒ０３または環Ａｒ０４における炭素数４~５０の芳香環上の置換基と同じものがあげられる。
　上記式（６）で表される含硫黄芳香族化合物の具体例としては、上記（Ｂ−００１）~（Ｂ−００４）、（Ｂ−００７）~（Ｂ−０１３）をあげることができる。
　本発明の高分子電解質組成物は、上記含硫黄芳香族化合物と高分子電解質とを配合することで調製することができる。その配合量は、高分子電解質が有しているイオン伝導性等の特性を著しく損なうことない範囲で選択される。好適には、高分子電解質１００重量部に対して、含硫黄芳香族化合物が０．０１~３０重量部であり、０．１~２０重量部であるとより好ましく、０．５~１０重量部であるとさらに好ましい。
　本発明に用いられる含硫黄芳香族化合物の分子量としては、高分子電解質組成物の調製時における溶液への溶解性もしくは分散性の観点から、８０以上１３００以下が好ましく、１６０以上１３００以下がより好ましく、１７０以上１０００以下がよりさらに好ましく、２００以上８００以下が特に好ましい。このような範囲に分子量を有する含硫黄芳香族化合物は高分子電解質組成物の調製時における溶液への溶解性もしくは分散性が高いため好ましい。
　分析により含硫黄芳香族化合物の分子量を求める場合は、ゲルパーミエーションクロマトグラフィー（ＧＰＣ）法により測定される該数平均分子量を用いることができる。
　以下にＧＰＣ測定条件を示す。
・カラム：東ソー社製　ＴＳＫｇｅｌ　ＧＭＨＨＲ−Ｍ
・カラム温度：４０℃
・移動相溶媒：Ｎ，Ｎ−ジメチルホルムアミド（ＬｉＢｒを１０ｍｍｏｌ／ｄｍ３になるように添加）
・溶媒流量：０．５ｍＬ／分
・検出：示差屈折率法
・標準物質：東ソー社製　標準ポリスチレン　Ａ３００、Ａ１０００、Ａ２５００、Ａ５０００、Ｆ１、Ｆ２、Ｆ１０、Ｆ４０、Ｆ１２８、Ｆ２８８
　なお、ＧＰＣ法での分析が困難な場合については、代わりに質量分析法を用いることができる。
＜高分子電解質＞
　次に、前記本発明の高分子電解質組成物が含有する高分子電解質について説明する。該高分子電解質としては、Ｎａｆｉｏｎ（デュポン社登録商標）、旭化成製のＡｃｉｐｌｅｘ（旭化成登録商標）、旭硝子製のＦｌｅｍｉｏｎ（旭硝子登録商標）などのイオン交換基を有するフッ素系高分子電解質や、脂肪族炭化水素や芳香族炭化水素にスルホ基（−ＳＯ３Ｈ）、カルボキシル基（−ＣＯＯＨ）、ホスホン基（−ＰＯ３Ｈ２）、スルホニルイミド基（−ＳＯ２ＮＨＳＯ２−）、フェノール性水酸基等のイオン交換基を導入した炭化水素系高分子電解質などが用いられる。炭化水素系高分子電解質はラジカル耐性が低いことが懸念されるので、本発明の高分子電解質組成物が含有する高分子電解質が炭化水素系高分子電解質である場合、本発明が奏する、優れたラジカル耐性を有する高分子電解質膜等が得られるという効果をよりよく享受できる。また、フッ素系高分子電解質に比して、耐熱性等の観点からも炭化水素系高分子電解質は有利である。なお、高分子電解質は、フッ素系高分子電解質と炭化水素系高分子電解質を組み合わせて含有してもよいが、この場合、高分子電解質の全量（１００重量％）に対して、炭化水素系高分子電解質が、５１重量％以上であると好ましく、７０重量％以上であるとより好ましくは、８５重量％以上であるとさらに好ましくは、９０重量％以上であると特に好ましい。
　なお、炭化水素系高分子電解質とは、当該高分子電解質を構成する元素重量含有比で表してハロゲン原子が１５重量％以下である高分子電解質を意味する。かかる炭化水素系高分子電解質は、前記のフッ素系高分子電解質と比較して安価であるという利点を有するため、より好ましい、特に好適な炭化水素系高分子電解質とは実質的にハロゲン原子を含有していないものであり、このような炭化水素系高分子電解質は燃料電池の作動時に、ハロゲン化水素を発生して、他の部材を腐食させたりする恐れがない。
　なお、フッ素系高分子電解質とは、当該高分子電解質を構成する元素重量含有比で表してフッ素原子が１５重量％を超える高分子電解質を意味する。具体例としては上記例示の市販のフッ素系高分子電解質などをあげることができる。
　上述のイオン交換基として、酸性のイオン交換基（すなわち、カチオン交換基）又は塩基性のイオン交換基（すなわち、アニオン交換基）があげられる。高いプロトン伝導性を得る観点から、イオン交換基はカチオン交換基であることが好ましく、カチオン交換基を有する高分子電解質を用いることにより、一層発電性能に優れた燃料電池が得られる。カチオン交換基としては、例えば、スルホ基（−ＳＯ３Ｈ）、カルボキシル基（−ＣＯＯＨ）、ホスホン基（−ＰＯ３Ｈ２）、スルホニルイミド基（−ＳＯ２ＮＨＳＯ２−）、フェノール性水酸基等があげられる。これらの中でも、カチオン交換基としては、スルホ基又はホスホン基がより好ましく、スルホ基が特に好ましい。なお、これらのイオン交換基は、部分的に、あるいは全てが、金属イオンや４級アンモニウムイオン等で交換されて塩を形成していてもよいが、燃料電池用部材として使用する際には、実質的に全てが遊離酸の形態であることが好ましい。これらのイオン交換基は、高分子電解質の主鎖、側鎖の何れか／又は両方に導入されていてもよいが、好ましくは主鎖へ導入されているものがあげられる。
　以下、好適なイオン交換基を有する炭化水素系高分子電解質に関し詳述する。このような炭化水素系高分子電解質の具体例としては、例えば、下記の（Ａ）~（Ｆ）で表される高分子電解質が挙げられる。
（Ａ）主鎖が脂肪族炭化水素からなる高分子に、イオン交換基が導入された高分子電解質；
（Ｂ）主鎖が脂肪族炭化水素からなり、主鎖の一部の水素原子がフッ素原子で置換された高分子に、イオン交換基が導入された高分子電解質；
（Ｃ）主鎖が芳香環を有する高分子に、イオン交換基が導入された高分子電解質；
（Ｄ）主鎖が、シロキサン基やフォスファゼン基等の無機の単位構造を有する高分子にイオン交換基が導入された高分子電解質；
（Ｅ）高分子電解質（Ａ）~（Ｄ）の調製に使用する高分子の主鎖を構成する構造単位から選ばれる２種以上の構造単位を組み合わせた共重合体に、イオン交換基が導入された高分子電解質；
（Ｆ）主鎖や側鎖に窒素原子を含む炭化水素系高分子に、硫酸やリン酸等の酸性化合物をイオン結合により導入した高分子電解質
　なお、以下においては、イオン交換基がスルホ基である高分子電解質を主として例示するが、このスルホ基を別のイオン交換基に置き換えた高分子電解質でもよい。
　前記（Ａ）の高分子電解質としては、例えば、ポリビニルスルホン酸、ポリスチレンスルホン酸、ポリ（α−メチルスチレン）スルホン酸等が挙げられる。
　前記（Ｂ）の高分子電解質としては、特開平９−１０２３２２号公報に記載された炭化フッ素系ビニルモノマーと炭化水素系ビニルモノマーとの共重合によって製造された高分子を主鎖とし、スルホ基を有する炭化水素鎖を側鎖とし、共重合様式がグラフト重合であるスルホン酸型ポリスチレン−グラフト−エチレン−テトラフルオロエチレン共重合体（ＥＴＦＥ）が挙げられる。また、米国特許第４，０１２，３０３号公報又は米国特許第４，６０５，６８５号公報に記載された方法により得られる炭化フッ素系ビニルモノマーと炭化水素系ビニルモノマーとの共重合体に、α，β，β−トリフルオロスチレンをグラフト重合させ、これにスルホ基を導入して固体高分子電解質としたスルホン酸型ポリ（トリフルオロスチレン）−グラフト−ＥＴＦＥも挙げることができる。
　前記（Ｃ）の高分子電解質は、主鎖に酸素原子等のヘテロ原子を含むものであってもよい。このような高分子電解質としては、例えば、ポリエーテルケトン、ポリエーテルエーテルケトン、ポリスルホン、ポリエーテルスルホン、ポリエーテルエーテルスルホン、ポリ（アリーレンエーテル）、ポリイミド、ポリ（（４−フェノキシベンゾイル）−１，４−フェニレン）、ポリフェニルキノキサレン等の単独重合体のそれぞれに、スルホ基が導入されたものが挙げられる。具体的には、スルホアリール化ポリベンズイミダゾール、スルホアルキル化ポリベンズイミダゾール（例えば、特開平９−１１０９８２号公報参照）等が挙げられる。前記（Ｃ）の高分子電解質は、主鎖が酸素原子等のヘテロ原子で中断されている化合物であってもよく、例えば、ポリエーテルエーテルケトン、ポリスルホン、ポリエーテルスルホン、ポリ（アリーレンエーテル）、ポリイミド、ポリ（（４−フェノキシベンゾイル）−１，４−フェニレン）、ポリフェニレンスルフィド、ポリフェニルキノキサレン、スルホアリール化ポリベンズイミダゾール、スルホアルキル化ポリベンズイミダゾール、ホスホアルキル化ポリベンズイミダゾール、ホスホン化ポリ（フェニレンエーテル）が挙げられる。このような高分子電解質は、特開平９−１１０９８２号公報、Ｊ．Ａｐｐｌ．Ｐｏｌｙｍ．Ｓｃｉ．，１８，１９６９（１９７４）にも記載されている。
　前記（Ｄ）の高分子電解質としては、例えば、ポリフォスファゼンにスルホ基が導入されたもの等が挙げられる。これらは、Ｐｏｌｙｍｅｒ　Ｐｒｅｐ．，４１，Ｎｏ．１，７０（２０００）に記載された方法に準じて容易に製造することができる。
　前記（Ｅ）の高分子電解質は、スルホ基が導入されたランダム共重合体、スルホ基が導入された交互共重合体、スルホ基が導入されたブロック共重合体のいずれであってもよい。
　前記（Ｆ）の高分子電解質としては、例えば、特表平１１−５０３２６２号公報に記載されたようなリン酸を含有させたポリベンズイミダゾール等が挙げられる。
　燃料電池用として良好な耐熱性を有する高分子電解質膜を得るためには、芳香族炭化水素系高分子電解質、特に主鎖に芳香環を有するもの（すなわち、上記（Ｃ））が好ましく、より機械強度に優れ、高耐熱性であることからも好ましい。上記（Ｃ）の中でも、さらには主鎖を構成する芳香環を有し、且つ該芳香環に直接結合または他の原子もしくは原子団を介して間接的に結合したイオン交換基を有する炭化水素系高分子電解質が好ましい。特に、主鎖を構成する芳香族を有し、さらに芳香環を有する側鎖を有してもよく、主鎖を構成する芳香環か側鎖の芳香環の、どちらかの芳香環に直接結合したイオン交換基を有する炭化水素系高分子電解質が好ましい。
　さらに、本実施形態の高分子電解質膜に使用する高分子電解質としては、イオン交換基を有する構造単位とイオン交換基を有しない構造単位とからなる共重合体が、高分子電解質膜としたとき、耐水性や機械強度に優れる傾向があるので、好ましい。この２種の構造単位の共重合様式は、ランダム共重合、交互共重合、ブロック共重合、グラフト共重合の何れでもよく、好ましくは、ランダム共重合、ブロック共重合、グラフト共重合であり、より好ましくは、ランダム共重合、ブロック共重合であり、特に好ましくはブロック共重合である。これらの共重合様式の組み合わせでもよい。
　本発明に適用する高分子電解質においては、プロトン伝導性を担うイオン交換基の導入量は、イオン交換容量で表して、０．５ｍｅｑ／ｇ以上が好ましく、１．０ｍｅｑ／ｇ以上がより好ましく、２．０ｍｅｑ／ｇ以上が更に好ましく、２．７ｍｅｑ／ｇ以上が特に好ましい。また、５．５ｍｅｑ／ｇ以下が好ましく、５．０ｍｅｑ／ｇ以下がより好ましい。イオン交換容量が前記の範囲であると、燃料電池用高分子電解質として、十分なプロトン伝導性が発現され、比較的耐水性も良好であるという利点もある。
　特に好ましい高分子電解質としては、下記式（１１ａ）、（１２ａ）、（１３ａ）又は（１４ａ）［以下、「式（１１ａ）~（１４ａ）」と呼ぶことがある］
Figure JPOXMLDOC01-appb-I000024
（式中、Ａｒ１~Ａｒ９は、それぞれ同一または相異なり、主鎖に芳香環を有し、さらに芳香環を有する側鎖を有してもよい２価の芳香族基を表す。該主鎖の芳香環か側鎖の芳香環の少なくとも１つが該芳香環に直接結合したイオン交換基を有する。
Ｚ、Ｚ’はそれぞれ同一または相異なり−ＣＯ−で示される基、−ＳＯ２−で示される基のいずれかを表し、Ｘ、Ｘ’、Ｘ”はそれぞれ同一または相異なり−Ｏ−で示される基、−Ｓ−で示される基のいずれかを表す。Ｙは直接結合もしくは下記一般式（１５）で表される基を表す。ｐは０、１又は２を表し、ｑ、ｒはそれぞれ同一または相異なり１、２又は３を表す。）
で示されるイオン交換基を有する構造単位と、
下記式（１１ｂ）、（１２ｂ）、（１３ｂ）又は（１４ｂ）［以下、「式（１１ｂ）~（１４ｂ）」と呼ぶことがある。］
Figure JPOXMLDOC01-appb-I000025
（式中、Ａｒ１１~Ａｒ１９は、それぞれ同一または相異なり側鎖としての置換基を有していてもよい２価の芳香族基を表す。Ｚ、Ｚ’はそれぞれ同一または相異なり−ＣＯ−で示される基、−ＳＯ２−で示される基のいずれかを表し、Ｘ、Ｘ’、Ｘ”はそれぞれ同一または相異なり−Ｏ−で示される基、−Ｓ−で示される基のいずれかを表す。Ｙは直接もしくは下記一般式（１５）で表される基を表す。ｐ’は０、１又は２を表し、ｑ’、ｒ’はそれぞれ同一または相異なり１、２又は３を表す。）
で表される、イオン交換基を有しない構造単位と、を有し、その共重合様式がランダム共重合、ブロック共重合、ブロック共重合又はグラフト共重合のいずれか、もしくはこれらの共重合様式を組合わせた高分子電解質が例示される。
Figure JPOXMLDOC01-appb-I000026
（式中、Ｒ１及びＲ２はそれぞれ同一または相異なり、水素原子、置換基を有していてもよい炭素数１~２０のアルキル基、置換基を有していてもよい炭素数１~２０のアルコキシ基、置換基を有していてもよい炭素数６~２０のアリール基、置換基を有していてもよい炭素数６~２０のアリールオキシ基又は置換基を有していてもよい炭素数２~２１のアシル基を表し、Ｒ１とＲ２とが連結して環を形成していてもよい。Ｒ１とＲ２とが連結して形成される環を有する式（１５）の基としては、シクロヘキシリデン基などの炭素数５~２０の２価の環状炭化水素基があげられる。）
　式（１１ａ）~（１４ａ）におけるＡｒ１~Ａｒ９は、２価の芳香族基を表す。ここで、２価の芳香族基とは、芳香族化合物から、２個の水素原子を取り去った残基である。以降、同様の意味で、「２価の芳香族基」と言う言葉を用いる。２価の芳香族基としては、例えば、１，３−フェニレン、１，４−フェニレン等の２価の単環性芳香族基、１，３−ナフタレンジイル、１，４−ナフタレンジイル、１，５−ナフタレンジイル、１，６−ナフタレンジイル、１，７−ナフタレンジイル、２，６−ナフタレンジイル、２，７−ナフタレンジイル等の２価の縮環系芳香族基、ピリジンジイル、キノキサリンジイル、チオフェンジイル、ピロール、２Ｈ−ピロール、イミダゾール、ピラゾール、イソオキサゾール、ピリジン、ピラジン、ピリミジン、ピリダジン、インドリジン、イソインドール、３Ｈ−インドール、インドール、１Ｈ−インダゾール、プリン、４Ｈ−キノリジン、キノリン、イソキノリン、フタラジン、ナフチリジン、キノキサリン、キナゾリン、シンノリン、プテリジン、カルバゾール、カルボリン、フェナントリジン、アクリジン、ペリミジン、フェナントロリン、フェナジン、フラザン、フェノキサジン、ピロリジン、ピロリン、イミダゾリン、イミダゾリジン、ピラゾリジン、ピラゾリン、ピペリジン、ピペラジン、インドリン、イソインドリン、キヌクリジン、オキサゾール、ベンゾオキサゾール、１，３，５−トリアジン、ブリン、テトラゾール、テトラジン、トリアゾール、フェナルサジン、ベンゾイミダゾール、ベンゾトリアゾールからなる群より選ばれる少なくとも１種から芳香環上の水素原子を２個取り去って得られるヘテロ芳香族基か、下記式（Ｎ−０１）~（Ｎ−０７）で表される構造からなる群より選ばれる少なくとも１種の構造を含むヘテロ芳香族基等があげられる。好ましくは２価の単環性芳香族基、２価の縮環系芳香族基であり、より好ましくは２価の単環性芳香族基である。
Figure JPOXMLDOC01-appb-I000027
　また、式（１１ａ）~（１４ａ）におけるＡｒ１~Ａｒ９で表される芳香族基の芳香環上の水素原子は、置換基を有していてもよい炭素数１~２０のアルキル基、置換基を有していてもよい炭素数１~２０のアルコキシ基、置換基を有していてもよい炭素数６~２０のアリール基、置換基を有していてもよい炭素数６~２０のアリールオキシ基又は置換基を有していてもよい炭素数２~２１のアシル基で置換されていてもよい。
　式（１１ａ）~（１４ａ）におけるＡｒ１Ａｒ９で表される芳香族基は、芳香環に少なくとも一つのイオン交換基を有する。これらのイオン交換基は、高分子電解質の主鎖、側鎖の何れか／又は両方に導入されていてもよいが、好ましくは主鎖を構成する芳香環に少なくとも一つのイオン交換基を有する芳香族基である。該イオン交換基として、上述のように酸性のイオン交換基が好ましく、酸性のイオン交換基の中でも、スルホ基又はホスホン基がより好ましく、スルホ基が特に好ましい。
　また、式（１４ａ）で表されるイオン交換基を有する構造単位の例の一つとして、下記式（１４ａ−１）で表される構造単位をあげることができる。
Figure JPOXMLDOC01-appb-I000028
　（上記式（１４ａ−１）中、Ａｒ１１０、Ａｒ１２０、Ａｒ１３０は、それぞれ独立に、２価の芳香族基を示し、該芳香環上の水素原子はフッ素原子で置換されていてもよい。Ｙは、−ＣＯ−、−ＳＯ２−、−ＳＯ−、−ＣＯＮＨ−，−ＣＯＯ−、−（ＣＦ２）ｕ０００−（ｕ０００は１~１０の整数である）、−Ｃ（ＣＦ３）２−または直接結合を示す。Ｚ０００は、−Ｏ−、−Ｓ−、直接結合、−ＣＯ−、−ＳＯ２−、−ＳＯ−、−（ＣＨ２）ｌ０００−（ｌ０００は１~１０の整数である）または−Ｃ（ＣＨ３）２−を示す。Ｒ１１０は、直接結合、−Ｏ（ＣＨ２）ｐ０００−、−Ｏ（ＣＦ２）ｐ０００−、−（ＣＨ２）ｐ０００−または−（ＣＦ２）ｐ０００−を示す（ｐ０００は、１~１２の整数を示す）。Ｒ１２０、Ｒ１３０は、それぞれ独立に、水素原子、アルカリ金属原子または炭化水素基を示す。ただし、上記式中に含まれる全てのＲ１２０およびＲ１３０のうち少なくとも１個は水素原子である。ｘ１００は、０~４の整数。ｘ２００は、１~５の整数。ａ０００は、０~１の整数。ｂ０００は、０~３の整数を示す。）
　式（１４ａ−１）におけるＡｒ１１０、Ａｒ１２０およびＡｒ１３０は、２価の芳香族基を表す。このような２価の芳香族基としては、式（１１ａ）~（１４ａ）におけるＡｒ１~Ａｒ９と同様の２価の芳香族基があげられる。
　Ｒ１２０、Ｒ１３０は、それぞれ独立に、水素原子、アルカリ金属原子または炭化水素基を示す。アルカリ金属原子としては、例えば、リチウム、ナトリウム、カリウム、ルビジウム、セシウム、ルビジウムがあげられ、炭化水素基としては、例えば、メチル基、エチル基、ｎ−プロピル基、ｉｓｏ−プロピル基、ｔｅｒｔ−ブチル基、ｉｓｏ−ブチル基、ｎ−ブチル基、ｓｅｃ−ブチル基、ネオペンチル基、シクロペンチル基、ヘキシル基、シクロヘキシル基、シクロペンチルメチル基、シクロヘキシルメチル基、アダマンチル基、アダマンタンメチル基、２−エチルヘキシル基、ビシクロ［２．２．１］ヘプチル基、ビシクロ［２．２．１］ヘプチルメチル基、テトラヒドロフルフリル基、２−メチルブチル基、３，３−ジメチル−２，４−ジオキソランメチル基、シクロヘキシルメチル基、アダマンチルメチル基、ビシクロ［２．２．１］ヘプチルメチル基などの直鎖状炭化水素基、分岐状炭化水素基、脂環式炭化水素基、複素環を有する炭化水素基などが挙げられる。これらのうちｎ−ブチル基、ネオペンチル基、テトラヒドロフルフリル基、シクロペンチル基、シクロヘキシル基、シクロヘキシルメチル基、アダマンチルメチル基、ビシクロ［２．２．１］ヘプチルメチル基が好ましく、さらにはネオペンチル基が好ましい。なお、Ｒ１２０、Ｒ１３０は、水素原子であることが好ましい。
　上記式（１４ａ−１）で表される構造単位は、さらに下記式（１４ａ−２）で表される構造単位であることが好ましい。
Figure JPOXMLDOC01-appb-I000029
（式（１４ａ−２）中、Ｙ００１は−ＣＯ−、−ＳＯ２−、−ＳＯ−、−ＣＯＮＨ−、−ＣＯＯ−、−（ＣＦ２）ｌ−（ここでのｌは１~１０の整数である）、−Ｃ（ＣＦ３）２−からなる群より選ばれた少なくとも１種の構造を示し、Ｚ００１は直接結合または、−（ＣＨ２）ｌ−（ここでのｌは１~１０の整数である）、−Ｃ（ＣＨ３）２−、−Ｏ−、−Ｓ−、−ＣＯ−、−ＳＯ２−からなる群より選ばれた少なくとも１種の構造を示し、Ａｒ００１は−ＳＯ３Ｈまたは−Ｏ（ＣＨ２）ｐＳＯ３Ｈまたは−Ｏ（ＣＦ２）ｐＳＯ３Ｈで表される置換基を有する芳香族基を示す。ｐは１~１２の整数を示し、ｍ００１は０~１０の整数を示し、ｎ００１は０~１０の整数を示し、ｋ００１は１~４の整数を示す。）
　上記式（１４ａ−２）で表されるイオン交換基を有する構造単位の具体例としては、後述の式（４ａ−１３）~（４ａ−２０）で表される構造単位をあげることができる
Figure JPOXMLDOC01-appb-I000030
香族基を表す。このような２価の芳香族基としては、例えば、１，３−フェニレン、１，４−フェニレン等の２価の単環性芳香族基、１，３−ナフタレンジイル、１，４−ナフタレンジイル、１，５−ナフタレンジイル、１，６−ナフタレンジイル、１，７−ナフタレンジイル、２，６−ナフタレンジイル、２，７−ナフタレンジイル等の２価の縮環系芳香族基、ピリジンジイル、キノキサリンジイル、チオフェンジイル、ピロール、２Ｈ−ピロール、イミダゾール、ピラゾール、イソオキサゾール、ピリジン、ピラジン、ピリミジン、ピリダジン、インドリジン、イソインドール、３Ｈ−インドール、インドール、１Ｈ−インダゾール、プリン、４Ｈ−キノリジン、キノリン、イソキノリン、フタラジン、ナフチリジン、キノキサリン、キナゾリン、シンノリン、プテリジン、カルバゾール、カルボリン、フェナントリジン、アクリジン、ペリミジン、フェナントロリン、フェナジン、フラザン、フェノキサジン、ピロリジン、ピロリン、イミダゾリン、イミダゾリジン、ピラゾリジン、ピラゾリン、ピペリジン、ピペラジン、インドリン、イソインドリン、キヌクリジン、オキサゾール、ベンゾオキサゾール、１，３，５−トリアジン、ブリン、テトラゾール、テトラジン、トリアゾール、フェナルサジン、ベンゾイミダゾール、ベンゾトリアゾールからなる群より選ばれる少なくとも１種の芳香環上の水素原子を２個取り去って得られるヘテロ芳香族基、及び下記式（Ｎ−０１）~（Ｎ−０７）で表される構造からなる群より選ばれる少なくとも１種の構造を含むヘテロ芳香族基等があげられる。好ましくは２価の単環性芳香族基、２価の縮環系芳香族基であり、より好ましくは２価の単環性芳香族基である。
Figure JPOXMLDOC01-appb-I000031
　また、Ａｒ１１~Ａｒ１９で表される芳香族基の芳香環上の水素原子は、フッ素原子、ホルミル基、シアノ基、置換基を有していてもよい炭素数１~２０のアルキル基、置換基を有していてもよい炭素数１~２０のアルコキシ基、置換基を有していてもよい炭素数６~２０のアリール基、置換基を有していてもよい炭素数６~２０のアリールオキシ基又は置換基を有していてもよい炭素数２~２１のアシル基で置換されていてもよい。なお、ここでいう「置換基を有していてもよい」の置換基とはイオン交換基を包含するものではない。
　ここで、前述の２価の芳香族基（式（１１ａ）~（１４ａ）におけるＡｒ１~Ａｒ９で表される芳香族基及び式（１１ｂ）~（１４ｂ）におけるＡｒ１１~Ａｒ１９で表される芳香族基）の置換基を以下に例示する。
　置換基を有していてもよい炭素数１~２０のアルキル基としては、例えば、メチル基、エチル基、ブチル基、ｎ−プロピル基、イソプロピル基、ｎ−ペンチル基、２，２−ジメチルプロピル基、シクロペンチル基、ｎ−ヘキシル基、シクロヘキシル基、２−メチルペンチル基、２−エチルヘキシル基、ノニル基、ドデシル基、ヘキサデシル基、オクタデシル基、イコシル基等の炭素数１~２０のアルキル基、及びこれらの基にフッ素原子、ヒドロキシル基、ニトリル基、アミノ基、メトキシ基、エトキシ基、イソプロピルオキシ基、フェニル基、ナフチル基、フェノキシ基、ナフチルオキシ基等が置換され、その総炭素数が２０以下であるアルキル基が挙げられる。
　置換基を有していてもよい炭素数１~２０のアルコキシ基としては、例えば、メトキシ基、エトキシ基、ブトキシ基、ｎ−プロポキシ基、イソプロポキシ基、ｎ−ペントキシ基、２，２−ジメチルプロポキシ基、シクロペントキシ基、ｎ−ヘキソキシ基、シクロヘキソキシ基、２−メチルペントキシ基、２−エチルヘキソキシ基、ドデシロキシ基、ヘキサデシロキシ基、イコシロキシ基等の炭素数１~２０のアルコキシ基、及びこれらの基にフッ素原子、ヒドロキシル基、ニトリル基、アミノ基、メトキシ基、エトキシ基、イソプロピルオキシ基、フェニル基、ナフチル基、フェノキシ基、ナフチルオキシ基等が置換され、その総炭素数が２０以下であるアルコキシ基が挙げられる。
　置換基を有していてもよい炭素数６~２０のアリール基としては、例えば、フェニル基、ナフチル基、フェナントレニル基、アントラセニル基等のアリール基、及びこれらの基にフッ素原子、ヒドロキシル基、ニトリル基、アミノ基、メトキシ基、エトキシ基、イソプロピルオキシ基、フェニル基、ナフチル基、フェノキシ基、ナフチルオキシ基等が置換され、その総炭素数が２０以下であるアリール基が挙げられる。
　置換基を有していてもよい炭素数６~２０のアリールオキシ基としては、例えば、フェノキシ基、ナフチルオキシ基、フェナントレニルオキシ基、アントラセニルオキシ基等のアリールオキシ基、及びこれらの基にフッ素原子、ヒドロキシル基、ニトリル基、アミノ基、メトキシ基、エトキシ基、イソプロピルオキシ基、フェニル基、ナフチル基、フェノキシ基、ナフチルオキシ基等が置換され、その総炭素数が２０以下であるアリールオキシ基が挙げられる。
　置換基を有していてもよい炭素数２~２１のアシル基としては、例えば、アセチル基、プロピオニル基、ブチリル基、イソブチリル基、ピバロイル基、ベンゾイル基、１−ナフトイル基、２−ナフトイル基等の炭素数２~２０のアシル基、及びこれらの基にフッ素原子、ヒドロキシル基、ニトリル基、アミノ基、メトキシ基、エトキシ基、イソプロピルオキシ基、フェニル基、ナフチル基、フェノキシ基、ナフチルオキシ基等が置換され、その総炭素数が２１以下であるアシル基が挙げられる。
　芳香環置換基は、フェニル基、ナフチル基、フェナントレニル基、アントラセニル基等のアリール基、フェノキシ基、ナフチルオキシ基、フェナントレニルオキシ基、アントラセニルオキシ基等のアリールオキシ基、ベンゾイル基、１−ナフトイル基、２−ナフトイル基等の芳香環を有するアシル基であると、ポリマーの耐熱性が良好となる傾向があり、より実用的な燃料電池用部材が得られるため好ましい。
　芳香環を有するアシル基を芳香環置換基として有する重合体を含む高分子電解質においては、該アシル基を有する２つの構造単位が隣接し、該２つの構造単位にあるアシル基同士が結合したり、このようにしてアシル基同士が結合した後、転位反応を生じたり、する場合がある。また、このように芳香環置換基同士が結合したり、結合後に転位反応を生じたりするような反応が生じたか否かは、例えば１３Ｃ−核磁気共鳴スペクトルの測定により確認することができる。
　該炭化水素系高分子電解質は、イオン交換基を有する構造単位及び、イオン交換基を有しない構造単位とを有し、イオン交換基を有する構造単位の密な相が膜厚方向に連続相を形成できれば、よりプロトン伝導性に優れる高分子電解質膜が得られるといった利点があるので好ましい。
　本発明において、好適な高分子電解質は、前記式（１１ａ）~（１４ａ）で表される構造単位からなる、イオン交換基を有する構造単位と、前記式（１１ｂ）~（１４ｂ）で表される構造単位からなる、イオン交換基を有しない構造単位とを有するものである。さらに好適なイオン交換基を有する構造単位とイオン交換基を有しない構造単位の組み合わせとしては、下記の表１の＜ａ＞~＜ｍ＞に示す構造単位の組み合わせをあげることができる。
Figure JPOXMLDOC01-appb-T000032
 　更に好ましくは、＜ｂ＞、＜ｃ＞、＜ｄ＞、＜ｇ＞、＜ｈ＞、＜ｉ＞、＜ｊ＞、＜ｌ＞、又は＜ｍ＞であり、より更に好ましくは＜ｇ＞、＜ｈ＞、＜ｌ＞、又は＜ｍ＞であり、＜ｇ＞、＜ｈ＞、＜ｌ＞が特に好ましい。
　好適な共重合体の例として、以下に示すイオン交換基を有する構造単位の群から選ばれる１種又は２種以上の構造単位と、以下に示すイオン交換基を有しない構造単位の群から選ばれる１種又は２種以上の構造単位と、からなる共重合体をあげることができる。また、これら構造単位同士は、直接結合で結合されているか、適当な原子又は原子団で結合された形態でもよい。ここでいう構造単位同士を結合する原子又は原子団の典型的な例としては、２価の芳香族基、酸素原子、硫黄原子、カルボニル基、スルホニル基又はこれらを組み合わせてなる２価の基をあげることができる。
（イオン交換基を有する構造単位）
Figure JPOXMLDOC01-appb-I000033
Figure JPOXMLDOC01-appb-I000034
（イオン交換基を有しない構造単位）
Figure JPOXMLDOC01-appb-I000035
Figure JPOXMLDOC01-appb-I000036
Figure JPOXMLDOC01-appb-I000037
　式（４ｂ−１５）~（４ｂ−３２）中、ｒ０００は０または１以上の整数を示す。ｒ０００は、好ましくは１００以下であり、より好ましくは１以上８０以下である。
　前記例示の中でも、イオン交換基を有する構造単位を表す式としては、（４ａ−１）及び／又は、（４ａ−２）及び／又は、（４ａ−３）及び／又は、（４ａ−４）及び／又は、（４ａ−５）及び／又は、（４ａ−６）及び／又は、（４ａ−７）及び／又は、（４ａ−８）及び／又は、（４ａ−９）及び／又は、（４ａ−１０）及び／又は、（４ａ−１１）及び／又は、（４ａ−１２）が好ましく、（４ａ−１０）及び／又は、（４ａ−１１）及び／又は、（４ａ−１２）がより好ましく、（４ａ−１１）及び／又は、（４ａ−１２）が特に好ましい。
　前記例示の中でも、イオン交換基を有しない構造単位を表す式としては、（４ｂ−１）及び／又は、（４ｂ−２）及び／又は、（４ｂ−３）及び／又は、（４ｂ−４）及び／又は、（４ｂ−５）及び／又は、（４ｂ−６）及び／又は、（４ｂ−７）及び／又は、（４ｂ−８）及び／又は、（４ｂ−９）及び／又は、（４ｂ−１０）及び／又は、（４ｂ−１１）、（４ｂ−１２）及び／又は、（４ｂ−１３）及び／又は及び／又は、（４ｂ−１４）が好ましく、（４ｂ−２）及び／又は、（４ｂ−３）及び／又は、（４ｂ−９）及び／又は、（４ｂ−１０）及び／又は、（４ｂ−１３）及び／又は、（４ｂ−１４）がより好ましく、（４ｂ−２）及び／又は、（４ｂ−３）及び／又は、（４ｂ−１３）及び／又は、（４ｂ−１４）がよりさらに好ましく、（４ｂ−２）及び／又は、（４ｂ−３）及び／又は、（４ｂ−１４）が特に好ましい。
　該炭化水素系高分子電解質は、イオン交換基を有する構造単位と、イオン交換基を有さない構造単位とを有するものであり、この２種の構造単位の共重合様式は、ランダム共重合、交互共重合、ブロック共重合、グラフト共重合の何れでもよく、これらの共重合様式の組み合わせでもよい。好ましくは、ランダム共重合、ブロック共重合、グラフト共重合であり、より好ましくは、ランダム共重合、ブロック共重合であり、特に好ましくはブロック共重合である。
　本発明において、好適なブロック共重合体は、前記式（１１ａ）~（１４ａ）で表される構造単位からなる、イオン交換基を有するセグメントと、前記式（１１ｂ）~（１４ｂ）で表される構造単位からなる、イオン交換基を実質的に有しないセグメントとを有するものである。また、好適なイオン交換基を有するセグメントを構成する構造単位とイオン交換基を実質的に有しないセグメントを構成する構造単位の組み合わせとしては、下記の表２の＜ａ＞~＜ｍ＞に示すセグメントの組み合わせをあげることができる。
Figure JPOXMLDOC01-appb-T000038
 　更に好ましくは、＜ｂ＞、＜ｃ＞、＜ｄ＞、＜ｇ＞、＜ｈ＞、＜ｉ＞、＜ｊ＞、＜ｌ＞、又は＜ｍ＞であり、より更に好ましくは＜ｇ＞、＜ｈ＞、＜ｌ＞、又は＜ｍ＞であり、＜ｇ＞、＜ｈ＞、＜ｌ＞が特に好ましい。
　前記例示の中でも、イオン交換基を有するセグメントを構成する繰り返し単位に用いられる構造単位を表す式としては（４ａ−１）及び／又は（４ａ−２）及び／又は（４ａ−３）及び／又は（４ａ−４）及び／又は（４ａ−５）及び／又は（４ａ−６）及び／又は（４ａ−７）及び／又は（４ａ−８）及び／又は（４ａ−９）及び／又は（４ａ−１０）及び／又は（４ａ−１１）及び／又は（４ａ−１２）が好ましく、
（４ａ−１０）及び／又は（４ａ−１１）及び／又は（４ａ−１２）がより好ましく、（４ａ−１１）及び／又は（４ａ−１２）が特に好ましい。
　本発明に係る上記ブロック共重合体の好ましい形態の一つとして、イオン交換基を有するセグメントの主鎖が、複数の芳香環が直接連結してなるポリアリーレン構造を有することがあげられる。そのようなセグメントの構造単位として、好ましくは前述の（４ａ−１０）及び／又は（４ａ−１１）及び／又は（４ａ−１２）及び／又は（４ａ−１３）及び／又は（４ａ−１４）及び／又は（４ａ−１５）及び／又は（４ａ−１６）及び／又は（４ａ−１７）及び／又は（４ａ−１８）及び／又は（４ａ−１９）及び／又は（４ａ−２０）があげられ、より好ましくは（４ａ−１０）及び／又は（４ａ−１１）及び／又は（４ａ−１２）があげられ、特に好ましくは（４ａ−１１）及び／又は（４ａ−１２）があげられる。
　このような構造単位を繰り返し単位を含むセグメント（すなわち、イオン交換基を有するセグメント）を有する高分子電解質、特に、このような繰り返し単位からなるセグメントを有する高分子電解質は、優れたイオン伝導性を発現できるものであり、当該セグメントがポリアリーレン構造となるために化学的安定性も比較的良好となる傾向がある。
ここで「ポリアリーレン構造」とは、主鎖を構成している芳香環同士が直接結合で結合されている形態であり、具体的には、該芳香環同士の結合の総数を１００％としたとき、直接結合の割合が８０％以上の構造であると好ましく、９０％以上の構造であるとより好ましく、９５％以上の構造であるとさらに好ましい。なお、直接結合で結合されている形態以外の形態とは、芳香環同士が２価の原子又は２価の原子団で結合している形態である。
　イオン交換基を有しないセグメントを構成する繰り返し単位に用いられる構造単位を表す式としては、（４ｂ−１）及び／又は（４ｂ−２）及び／又は（４ｂ−３）及び／又は（４ｂ−４）及び／又は（４ｂ−５）及び／又は（４ｂ−６）及び／又は（４ｂ−７）及び／又は（４ｂ−８）及び／又は（４ｂ−９）及び／又は（４ｂ−１０）及び／又は（４ｂ−１１）及び／又は（４ｂ−１２）及び／又は（４ｂ−１３）及び／又は及び／又は（４ｂ−１４）が好ましく、（４ｂ−２）及び／又は（４ｂ−３）及び／又は（４ｂ−９）及び／又は（４ｂ−１０）及び／又は（４ｂ−１３）及び／又は（４ｂ−１４）がより好ましく、（４ｂ−２）及び／又は（４ｂ−３）及び／又は（４ｂ−１３）及び／又は（４ｂ−１４）がよりさらに好ましく、（４ｂ−２）及び／又は（４ｂ−３）及び／又は（４ｂ−１４）が特に好ましい。
　また、イオン交換基を有するセグメントとイオン交換基を実質的に有しないセグメントとは、直接結合している形態でもよく、適当な原子又は原子団で連結している形態でもよい。ここでいうセグメント同士を結合する原子又は原子団の典型的な例としては、２価の芳香族基、酸素原子、硫黄原子、カルボニル基、スルホニル基又はこれらを組み合わせてなる２価の基をあげることができる。
　好適なブロック共重合体の例として、上記に示すイオン交換基を有する構造単位の群から選ばれる１種又は２種以上の構造単位を含むセグメント（すなわち、イオン交換基を有するセグメント）と、上記に示すイオン交換基を有しない構造単位の群から選ばれる１種又は２種以上の構造単位を含むセグメント（すなわち、イオン交換基を実質的に有しないセグメント）と、からなるブロック共重合体をあげることができる。
　ここで、「イオン交換基を有するセグメント」とは、イオン交換基が、該セグメントを構成する構造単位１個あたりで平均０．５個以上含まれているセグメントを意味し、構造単位１個あたりでイオン交換基が平均１．０個以上含まれているとより好ましい。
　一方、「イオン交換基を実質的に有しないセグメント」とは、イオン交換基が、該セグメントを構成する構造単位１個あたりで平均０．５個未満であるセグメントを意味し、構造単位１個あたりでイオン交換基の個数が平均０．１個以下であるとより好ましく、平均０．０５個以下であるとさらに好ましい。
　典型的には、イオン交換基を有するセグメントとイオン交換基を実質的に有しないセグメントとが、直接結合で結合されているか、適当な原子又は原子団で結合された形態のブロック共重合体である。
　上記式（１１ａ）~（１４ａ）で表される構造単位から選ばれる１種以上の構造単位からなるセグメントの重合度は２以上であり、３以上が好ましく、５以上がより好ましく、１０以上が更に好ましい。また、かかるセグメントの重合度は１０００以下が好ましく、５００以下が好ましい。この重合度が２以上、好ましくは５以上であれば、燃料電池用の高分子電解質として、十分なプロトン伝導度を発現し、この重合度が１０００以下であれば、製造がより容易である利点がある。
　また、式（１１ｂ）~（１４ｂ）で表される構造単位から選ばれる構造単位からなるセグメントの重合度は１以上であり、２以上が好ましく、３以上がより好ましい。また、セグメントの重合度は１００以下が好ましく、９０以下がより好ましく、８０以下が更に好ましい。このような範囲内であれば、燃料電池用の高分子電解質として、十分な機械強度を有し、製造が容易であるので好ましい。
　また、本発明で用いられる炭化水素系高分子電解質の分子量は、ポリスチレン換算の数平均分子量で表して、５０００~１００００００であることが好ましく、１００００~８０００００であることがより好ましく、１００００~６０００００であることがより更に好ましく、中でも１５０００~４０００００であることが特に好ましい。このような範囲の分子量の高分子電解質を用いることにより、後述の方法にて作成される高分子電解質膜は、その膜の形状を安定的に維持できる傾向がある。該数平均分子量は、ゲルパーミエーションクロマトグラフィー（ＧＰＣ）により測定される。
＜高分子電解質膜＞
　本発明の高分子電解質膜は、上記の含硫黄芳香族化合物と高分子電解質とを含有する高分子電解質組成物を含むことを特徴とする。高分子電解質膜は、以下の（ｉ）~（ｉｖ）の工程を含む溶液キャスト法により製造される高分子電解質膜が好ましい。
　（ｉ）上述のような高分子電解質組成物を、高分子電解質および／または高分子電解質組成物を溶解し得る有機溶媒に溶解し、高分子電解質溶液を調製する工程；
　（ｉｉ）前記（ｉ）で得られた高分子溶液を、比較的平滑な表面を有する支持基材上に流延塗工し、該支持基材上に高分子電解質流延膜を形成する工程；
　（ｉｉｉ）前記（ｉｉ）で支持基材上に形成された高分子電解質流延膜から、前記有機溶媒を除去して、該支持基材上に高分子電解質膜を形成する工程；
　（ｉｖ）前記（ｉｉｉ）の工程を行った後、支持基材と高分子電解質膜とを分離する工程
　ここで、前記溶液キャスト法に関する各工程（ｉ）~（ｉｖ）に関し順次説明する。
　まず、（ｉ）では上述のように高分子電解質溶液を調製する。ここで該高分子電解質溶液調製に使用する有機溶媒としては、使用する１種又は２種以上の高分子電解質を溶解し得るものが選ばれる。また、高分子電解質および／または高分子電解質組成物に加えて、添加剤などの成分を用いる場合は、これら他の成分も共に溶解し得る溶媒が好ましい。
　使用する有機溶媒は、使用する高分子電解質および／または高分子電解質組成物を溶解し得る溶媒であり、好ましくは、この高分子電解質および／または高分子電解質組成物を、２５℃で１重量％以上の濃度で溶解し得る有機溶媒である。より好適には、高分子電解質および／または高分子電解質組成物を５~５０重量％の濃度で溶解し得る有機溶媒を用いる。
　また、この有機溶媒は、前記支持基材上に前記高分子電解質流延膜を形成した後に、加熱処理により除去し得る程度の揮発性が必要である。ただし、該有機溶媒は少なくとも１種、１０１．３ｋＰａ（１気圧）における沸点が１５０℃以上である有機溶媒を含むことが好ましい。前記高分子電解質および／または高分子電解質組成物を溶解し得る有機溶媒として沸点が１５０℃未満の有機溶媒のみを用いると、後述する工程（ｉｉｉ）で高分子電解質流延膜から有機溶媒を除去して高分子電解質膜を形成しようとすると、形成した高分子電解質膜に凹凸状の外観不良が発生するおそれがある。これは、沸点が１５０℃未満である有機溶媒では、前記高分子電解質流延膜から急激に有機溶媒が揮発してしまうためである。
　前記高分子電解質溶液の調製に好適な有機溶媒としては、ジメチルホルムアミド（ＤＭＦ）、ジメチルアセトアミド（ＤＭＡｃ）、Ｎ−メチル−２−ピロリドン（ＮＭＰ）、ジメチルスルホキシド（ＤＭＳＯ）、γ−ブチロラクトン（ＧＢＬ）などの非プロトン性極性溶媒、ジクロロメタン、クロロホルム、１，２−ジクロロエタン、クロロベンゼン、ジクロロベンゼンなどの塩素系溶媒、メタノール、エタノール、プロパノールなどのアルコール類、エチレングリコールモノメチルエーテル、エチレングリコールモノエチルエーテル、プロピレングリコールモノメチルエーテル、プロピレングリコールモノエチルエーテルなどのアルキレングリコールモノアルキルエーテルが挙げられる。これらは単独で用いることもできるが、２種以上の有機溶媒を混合して用いることもできる。中でも、非プロトン性極性溶媒を含む有機溶媒が好ましく、実質的に非プロトン性極性溶媒からなる有機溶媒が特に好ましい。ここでいう「実質的に非プロトン性極性溶媒からなる有機溶媒」とは企図せず含有される水分などの存在を排除するものではない。該非プロトン性極性溶媒は、支持基材に対して親和性が比較的小さく、該支持基材に非プロトン性極性溶媒が吸収され難いという利点もある。また、上述の好適な高分子電解質であるブロック共重合体の溶解性が高いという点では、該非プロトン性極性溶媒の中でも、ＤＭＳＯ、ＤＭＦ、ＤＭＡｃ、ＮＭＰ、ＧＢＬ又はこれらから選ばれる２種以上の混合溶媒が好ましい。
　次に、工程（ｉｉ）について説明する。
　この工程は、前記工程（ｉ）で得られた高分子電解質溶液を支持基材上に流延塗工する工程である。該流延塗工の方法としては、ローラーコート法、スプレイコート法、カーテンコート法、スロットコート法、スクリーン印刷法などの各種手段を用いることができるが、好ましくは、ダイと呼ばれる一定クリアランスが設けられた金型により、所定の幅及び厚みに高分子電解質溶液を賦型する手段があげられる。このようにして支持基材上に形成された高分子電解質流延膜は、塗工時に高分子電解質溶液中の有機溶媒の一部が揮発するために膜の形状を有するものとなる。この際の高分子電解質流延膜の膜厚は、３~５０μｍになるようにしておくことが好ましい。このような膜厚の高分子電解質流延膜を得るには、使用する高分子電解質溶液の高分子電解質濃度、塗工装置の塗出量などを適宜調整すればよい。また、該支持基材が連続的に走行する基材である場合は、その支持基材の走行速度等で調節することもできる。
　工程（ｉｉ）で使用する支持基材としては、流延塗工に供する高分子電解質溶液に対して十分な耐久性を有し、後述する工程（ｉｉｉ）での処理条件に対しても耐久性を有する材質からなるものが選択される。この場合の耐久性とは、高分子電解質溶液によって支持基材自身が実質的に溶け出さないことや、工程（ｉｉｉ）の処理条件により、支持基材自身が膨潤や収縮を起こさず寸法安定性がよいことなどを意味するものである。
　該支持基材としては、たとえばガラス板；ＳＵＳ箔、銅箔等の金属箔；ポリエチレンテレフタレート（ＰＥＴ）フィルム、ポリエチレンナフタレート（ＰＥＮ）フィルム等のプラスチックフィルムをあげることができる。また、このプラスチックフィルムには、上述したような耐久性を著しく損なわない範囲で、そのフィルム表面に対し、ＵＶ処理、離型処理、エンボス処理などの表面処理を行ってもよい。
　次に工程（ｉｉｉ）に関し説明する。
　この工程は前記工程（ｉｉ）において前記支持基材上に形成された高分子電解質流延膜に含有される前記有機溶媒を除去して、該支持基材上に高分子電解質膜を形成する工程である。このような除去には、乾燥又は洗浄溶媒による洗浄が推奨される。このような乾燥と洗浄とを組み合わせて、前記有機溶媒を除去することがより一層好ましく、乾燥と洗浄とを組み合わせる場合には、まず乾燥を行って、前記支持基材上に形成された高分子電解質流延膜に含有される前記有機溶媒のほとんど全てを除去した後、洗浄溶媒による洗浄を行うことが特に好ましい。
　ここでは、工程（ｉｉｉ）として好適な方法である乾燥と洗浄とを、この順で実施することについて詳述する。工程（ｉｉ）を経て得られた支持基材上に形成された高分子電解質流延膜から有機溶媒を乾燥除去するには、加熱、減圧、通風などの処理を採用することができるが、生産性が良好である点と、操作が容易である点で加熱処理が好ましい。この場合、高分子電解質流延膜が形成された支持基材（以下、場合により「第１の積層フィルム」という）を、直接加熱、温風接触などにより加熱処理する。高分子電解質流延膜中の高分子電解質を著しく損なわない点で、温風処理が特に好ましい。たとえば、該第１の積層フィルムが長尺状であり、かかる長尺状の第１の積層フィルムを連続的に処理する場合は、乾燥炉中に該第１の積層フィルムを通過させればよい。このときの乾燥炉は、４０~１５０℃の範囲、好ましくは５０~１４０℃に温度設定された温風を、該第１の積層フィルムの通過方向に対し垂直方向及び／又は対向方向に沿って送風する。こうすることにより、支持基材上にある高分子電解質流延膜から有機溶媒等の揮発成分が乾燥（蒸発）除去され、該支持基材上に高分子電解質膜が形成された第２の積層フィルムが形成される。
　このようにして得られた第２の積層フィルムの高分子電解質膜中には、まだ若干量の有機溶媒が含有されているため、この有機溶媒を洗浄溶媒で洗浄する。洗浄溶媒で洗浄することにより、外観等に優れる高分子電解質膜が得られ易い。前記高分子電解質溶液の調製において好適な有機溶媒である、ＤＭＳＯ、ＤＭＦ、ＤＭＡｃ、ＮＭＰ又はＧＢＬ、あるいはこれらの組合せからなる混合溶媒を使用した場合、前記洗浄溶媒には純水、特に超純水を使用することが好ましい。
　上述のように、第１の積層フィルムが長尺状であって連続的に走行している場合、乾燥炉を通過して連続的に形成された第２の積層フィルムは、たとえば洗浄溶媒を充填した洗浄槽中を通過させることにより洗浄することができる。また、乾燥炉を通過して連続的に形成された第２の積層フィルムを適当な巻芯に巻き取って巻取り体として後、この巻取り体を、洗浄処理を担う洗浄装置へと移し変え、移し変えた巻取り体から第２の積層フィルムを洗浄槽へと送り出す形式で洗浄を行うこともできる。こうすることで、第２の積層フィルムにある高分子電解質膜の有機溶媒含有量はより一層低減することが可能である。
　かくして得られた第２の積層フィルムから支持基材を剥離などによって除去することにより高分子電解質膜は得られる。この高分子電解質膜は好適な溶液キャスト法により得られたものであるため、実質的に無多孔質の膜となる。なお、ここでいう実質的に無多孔質とは、ボイドなどの微小貫通孔が高分子電解質膜に形成されていないことを意味する。ただし、この高分子電解質膜は、燃料電池の作動に支障のない程度の少数量のボイド又は小さい径のボイドであれば、当該ボイドを有するような膜であってもよい。
　また、上述の溶液キャスト法による高分子電解質膜製造では、主として支持基材が連続的に走行している場合を説明したが、無論枚葉の支持基材を用いても、高分子電解質膜を得ることができる。この場合、枚葉の支持基材上に塗工された高分子電解質溶液は、適当な乾燥炉中に保管することで、有機溶媒を除去することができるし、このようにして得られた枚葉の第２の積層フィルムは、洗浄溶媒を備えた洗浄槽に浸漬等することで洗浄処理を行うことができる。
　また、洗浄後の第２の積層フィルムは、支持基材を除去した後、残存又は付着している洗浄溶媒を乾燥除去させてもよいし、洗浄後の第２の積層フィルムをそのまま加熱等することで残存又は付着している洗浄溶媒を乾燥除去した後、支持基材を除去してもよい。
　以上、前記溶液キャスト法による実質的に無多孔質の高分子電解質膜の製造方法を説明したが、既述のとおり、この高分子電解質膜には上記の含硫黄芳香族化合物と高分子電解質以外の成分（以下、「その他の成分」と記すことがある）を含有させることができる。その他の成分としては、通常の高分子に使用される可塑剤、安定剤、離型剤、保水剤等の添加剤があげられる。これらその他の成分は、溶液キャスト法を用いる際に、使用する高分子電解質溶液を調製する際に、該高分子電解質溶液にこれらの成分を添加しておけばよい。
＜燃料電池＞
　次に、前記本発明の高分子電解質膜を有する燃料電池について説明する。本発明の燃料電池は、本発明の高分子電解質膜の両面に、触媒および集電体としての導電性物質を接合することにより製造することができる。
　ここで触媒としては、水素又は酸素との酸化還元反応を活性化できるものであれば特に制限はなく、公知の触媒を用いることができるが、白金又は白金系合金の微粒子を触媒として用いることが好ましい。白金又は白金系合金の微粒子はしばしば活性炭や黒鉛などの粒子状または繊維状のカーボンに担持されて用いられることもある。
　また、カーボンに担持された白金又は白金系合金を、パーフルオロアルキルスルホン酸樹脂の溶剤と共に混合して調製したペースト（触媒インク）を、ガス拡散層に塗布・乾燥することにより、ガス拡散層と積層一体化した触媒層が得られる。得られた触媒層を、高分子電解質膜に接合させれば、燃料電池用の膜−電極接合体を得ることができる。具体的な方法としては例えば、Ｊ．　Ｅｌｅｃｔｒｏｃｈｅｍ．　Ｓｏｃ．：　Ｅｌｅｃｔｒｏｃｈｅｍｉｃａｌ　Ｓｃｉｅｎｃｅ　ａｎｄ　Ｔｅｃｈｎｏｌｏｇｙ，　１９８８，　１３５（９），　２２０９に記載されている方法等の公知の方法を用いることができる。また、触媒インクを、高分子電解質膜に塗布し、乾燥して、この膜の表面上に、直接触媒層を形成させても、燃料電池用の膜−電極接合体を得ることができる。
　ここで、触媒層に使用する高分子電解質として、前記のパーフルオロアルキルスルホン酸樹脂の代わりに、本発明の高分子電解質および／または高分子電解質組成物を用い、触媒組成物とすることもできる。この触媒組成物を用いて得られる触媒層は、前記の高分子電解質膜と同様に、良好な長期安定性を発現できるため、触媒層として好適である。
　集電体としての導電性物質に関しても公知の材料を用いることができるが、多孔質性のカーボン織布、カーボン不織布またはカーボンペーパーが、原料ガスを触媒へ効率的に輸送するために好ましい。
　このようにして製造された本発明の燃料電池は、燃料として水素ガス、改質水素ガス、メタノールを用いる各種の形式で使用可能である。
　本発明の高分子電解質膜を用いた膜−電極接合体および燃料電池においては、高分子電解質膜中に導入した含硫黄芳香族化合物が触媒層へ移行することもある。このような移行は、該高分子電解質膜の両面に触媒および集電体としての導電性物質を接合する工程および／又は燃料電池の運転時などに起こることがある。なお、ここでの運転とは、燃料電池のエージング、起動、作動、および停止の何れかをさす。このような形態も、前記の高分子電解質膜および前記の触媒層と同様に、良好な長期安定性を発現できるため、好適である。 Hereinafter, preferred embodiments according to the polymer electrolyte composition of the present invention will be specifically described. The electrolyte composition of the present invention contains one or more sulfur-containing aromatic compounds selected from the group consisting of the following sulfur-containing aromatic compounds [A] to [D] and a polymer electrolyte.
First, the sulfur-containing aromatic compound [A] will be described.
Sulfur-containing aromatic compound [A]: A sulfur-containing aromatic compound represented by the following formula (1).
Figure JPOXMLDOC01-appb-I000013
(In formula (1), Y 1 Represents a divalent group containing a sulfur atom. C 1 ~ C 4 Each represents a carbon atom. Ring Ar 01 Is C 1 And C 2 And an aromatic ring having 4 to 50 carbon atoms which may have a substituent. Ring Ar 02 Is C 3 And C 4 And an aromatic ring having 4 to 50 carbon atoms which may have a substituent. Ar 01 May have a substituent and Ar 02 Each may have a hydroxyl group, halogeno group, cyano group, carboxy group, phosphono group, sulfo group, formyl group, mercapto group, methyl group, or optionally substituted carbon number 4 An aryl group having from 20 to 20, an aryloxy group having 4 to 20 carbon atoms which may have a substituent, an arylthio group having 4 to 20 carbon atoms which may have a substituent, and a substituent. It is at least one group selected from the group consisting of an aroyl group having 5 to 21 carbon atoms and an arylsulfonyl group having 4 to 20 carbon atoms which may have a substituent. X 1 And X 2 Are the same or different and each has a hydrogen atom, hydroxyl group, halogeno group, cyano group, carboxy group, phosphono group, sulfo group, formyl group, mercapto group, methyl group, or optionally substituted carbon atoms of 4 to 20 aryl groups, optionally substituted aryloxy groups having 4 to 20 carbon atoms, optionally substituted arylthio groups having 4 to 20 carbon atoms, optionally having substituents It represents a good aroyl group having 5 to 21 carbon atoms or an arylsulfonyl group having 4 to 20 carbon atoms which may have a substituent. )
In the above formula (1), Y 1 Represents a divalent group containing a sulfur atom. Y 1 Are preferably a divalent group containing a divalent or tetravalent sulfur atom, more preferably a sulfur atom (a group represented by -S-) or a sulfinyl group (a group represented by -SO-). More preferred is a sulfur atom.
In the above formula (1), C 1 ~ C 4 Represents a carbon atom. C 1 -C 2 Bond and C 3 -C 4 Each bond is a carbon-carbon bond in an aromatic ring.
Ring Ar 01 Is C 1 And C 2 And an aromatic ring having 4 to 50 carbon atoms which may have a substituent. Ring Ar 02 Is C 3 And C 4 And an aromatic ring having 4 to 50 carbon atoms which may have a substituent. The aromatic ring preferably has 4 to 30 carbon atoms, more preferably 4 to 25 carbon atoms, and particularly preferably 6 to 20 carbon atoms.
Examples of the aromatic ring having 4 to 50 carbon atoms include monocyclic aromatic rings such as benzene, diphenyl ether, diphenyl sulfide, benzophenone, biphenyl, biphenylene, indacene, acenaphthylene, fluorene, phenalene, phenanthrene, anthracene, fluoranthene, triphenylene, and pyrene. , Condensed ring aromatic rings such as naphthacene and perylene, and aromatic rings containing heteroatoms such as furan, benzofuran and dibenzofuran in the ring.
The aromatic ring having 4 to 50 carbon atoms may have a substituent, which includes a hydroxyl group, a halogeno group, a cyano group, a carboxy group, a phosphono group, a sulfo group, a formyl group, a mercapto group, a methyl group, An aryl group having 4 to 20 carbon atoms which may have a substituent, an aryloxy group having 4 to 20 carbon atoms which may have a substituent, and 4 to 4 carbon atoms which may have a substituent It is a group selected from 20 arylthio groups, optionally substituted aroyl groups having 5 to 21 carbon atoms, and optionally substituted arylsulfonyl groups having 4 to 20 carbon atoms.
The substituent on the aromatic ring having 4 to 50 carbon atoms is preferably a halogeno group, a cyano group, a carboxy group, a phosphono group, a sulfo group, a formyl group, a mercapto group, or an optionally substituted carbon number of 4 An aryl group having from 20 to 20, an aryloxy group having 4 to 20 carbon atoms which may have a substituent, an arylthio group having 4 to 20 carbon atoms which may have a substituent, and a substituent. Or a group selected from an aroyl group having 5 to 21 carbon atoms and an arylsulfonyl group having 4 to 20 carbon atoms which may have a substituent, and more preferably a cyano group, a carboxy group, a phosphono group, a sulfo group. A group, a formyl group, an aryl group having 4 to 20 carbon atoms which may have a substituent, an aryloxy group having 4 to 20 carbon atoms which may have a substituent, and a substituent. Good arylthio having 4 to 20 carbon atoms A group selected from an aroyl group having 5 to 21 carbon atoms which may have a substituent, and an arylsulfonyl group having 4 to 20 carbon atoms which may have a substituent, and more preferably a cyano group A group, a carboxy group, an aryl group having 4 to 20 carbon atoms which may have a substituent, an aryloxy group having 4 to 20 carbon atoms which may have a substituent, and a substituent. A group selected from an arylthio group having 4 to 20 carbon atoms, an aroyl group having 5 to 21 carbon atoms which may have a substituent, and an arylsulfonyl group having 4 to 20 carbon atoms which may have a substituent Particularly preferably, the aryl group having 4 to 20 carbon atoms which may have a substituent, the arylthio group having 4 to 20 carbon atoms which may have a substituent, and a substituent. It may have an aroyl group having 5 to 21 carbon atoms or a substituent. There is a group selected from an arylsulfonyl group having 4-20 carbon atoms.
X above 1 And X 2 Each independently represents a hydrogen atom, a hydroxyl group, a halogeno group, a cyano group, a carboxy group, a phosphono group, a sulfo group, a formyl group, a mercapto group, a methyl group, or an aryl group having 4 to 20 carbon atoms, which may have a substituent. Group, an aryloxy group having 4 to 20 carbon atoms which may have a substituent, an arylthio group having 4 to 20 carbon atoms which may have a substituent, and a carbon number which may have a substituent An arylsulfonyl group having 5 to 21 carbon atoms and an optionally substituted arylsulfonyl group having 4 to 20 carbon atoms. Preferably, it has a hydrogen atom, a halogeno group, a cyano group, a carboxy group, a phosphono group, a sulfo group, a formyl group, a mercapto group, an optionally substituted aryl group having 4 to 20 carbon atoms, or a substituent. An optionally substituted aryloxy group having 4 to 20 carbon atoms, an arylthio group having 4 to 20 carbon atoms which may have a substituent, an aroyl group having 5 to 21 carbon atoms which may have a substituent, An arylsulfonyl group having 4 to 20 carbon atoms which may have a substituent, more preferably a hydrogen atom, a cyano group, a carboxy group, a phosphono group, a sulfo group, a formyl group, or a substituent. An aryl group having 4 to 20 carbon atoms, an aryloxy group having 4 to 20 carbon atoms which may have a substituent, an arylthio group having 4 to 20 carbon atoms which may have a substituent, and a substituent May have 5 to 2 carbon atoms An aroyl group, an arylsulfonyl group having 4 to 20 carbon atoms that may have a substituent, and more preferably a hydrogen atom, a cyano group, a carboxy group, or a carbon group that may have a substituent 4 to 20 aryl group, optionally having 4 to 20 carbon atoms aryloxy group, optionally having 4 to 20 carbon atoms arylthio group, having substituents An aroyl group having 5 to 21 carbon atoms, and an arylsulfonyl group having 4 to 20 carbon atoms which may have a substituent, and particularly preferably a hydrogen atom and an optionally substituted carbon. An aryl group having 4 to 20 carbon atoms, an arylthio group having 4 to 20 carbon atoms which may have a substituent, an aroyl group having 5 to 21 carbon atoms which may have a substituent, and a substituent; Or an arylsulfonyl group having 4 to 20 carbon atoms.
Examples of the halogeno group include a fluoro group, a chloro group, a bromo group, and an iodo group, and a fluoro group is preferable.
Examples of the aryl group having 4 to 20 carbon atoms which may have the above substituent include phenyl, o-methylphenyl, m-methylphenyl, p-methylphenyl, o-phenoxyphenyl, m-phenoxyphenyl, p- Monocyclic aryl groups such as phenoxyphenyl, o-chlorophenyl, m-chlorophenyl, p-chlorophenyl and biphenyl, and condensed ring aryls such as 1-naphthyl, 2-naphthyl, 1-anthracyl, 2-anthracyl and 4-anthracyl groups Groups, heteroaryl groups such as 2-thienyl, 3-thienyl, 2-furyl, 3-furyl and the like.
As the aryloxy group having 4 to 20 carbon atoms which may have the above-mentioned substituent, an aryl group selected from the exemplified group of aryl groups having 4 to 20 carbon atoms which may have the aforementioned substituent And a group in which a hydrogen atom of a hydroxyl group is substituted.
As the arylthio group having 4 to 20 carbon atoms which may have the above-mentioned substituent, an aryl group selected from the exemplified group of aryl groups having 4 to 20 carbon atoms which may have the aforementioned substituent And a group in which a hydrogen atom of a mercapto group is substituted.
As the above-mentioned aroyl group having 5 to 21 carbon atoms which may have a substituent, an aryl group selected from the above-mentioned exemplified group of aryl groups having 4 to 20 carbon atoms which may have a substituent And a group in which a hydrogen atom of the formyl group is substituted.
Examples of the arylsulfonyl group having 4 to 20 carbon atoms which may have the above substituent include phenylsulfonyl, o-methylphenylsulfonyl, m-methylphenylsulfonyl, p-methylphenylsulfonyl, o-phenoxyphenylsulfonyl, m -Monocyclic arylsulfonyl groups such as -phenoxyphenylsulfonyl, p-phenoxyphenylsulfonyl, o-chlorophenylsulfonyl, m-chlorophenylsulfonyl, p-chlorophenylsulfonyl, 1-naphthylsulfonyl, 2-naphthylsulfonyl, 1-anthracylsulfonyl, Examples thereof include condensed ring arylsulfonyl groups such as 2-anthracylsulfonyl and 4-anthracylsulfonyl groups, and heteroarylsulfonyl groups such as 2-thienylsulfonyl and 3-thienylsulfonyl.
Examples of the sulfur-containing aromatic compound [A] represented by the above formula (1) include phenyl sulfide, bis (2-hydroxy-5-chlorophenyl) sulfide, 4-benzoyl 4′-methyldiphenyl sulfide, bis (4 -Hydroxy-3-methylphenyl) sulfide, bis (4-methacryloylthiophenyl) sulfide, bis (4-hydroxyphenyl) sulfide, phenyl p-tolyl sulfide, 5,5'-thiodisalicylic acid, 2,2'-thiobis (4,6-dichlorophenol) disodium, 2,2′-thiobis (4,6-dichlorophenol), 4,4′-thiobisbenzenethiol 4-chlorophenyl sulfoxide, diphenyl sulfoxide, p-tolyl sulfoxide, 1, 1′-thiobis (2-naphthol), 1,1′-thiobis (2 Naphthalene), etc. may be mentioned bis (2-naphthyl) sulfoxide.
Next, the sulfur-containing aromatic compound [B] will be described.
Sulfur-containing aromatic compound [B]: A sulfur-containing aromatic compound represented by the following formula (2).
Figure JPOXMLDOC01-appb-I000014
(In formula (2), Y 1 Is as defined above. Z 1 Represents a direct bond or a divalent group represented by any of the following formulas (2-1) to (2-9). C 5 ~ C 8 Each represents a carbon atom. Ring Ar 03 Is C 5 And C 6 And an aromatic ring having 4 to 50 carbon atoms which may have a substituent. Ring Ar 04 Is C 7 And C 8 And an aromatic ring having 4 to 50 carbon atoms which may have a substituent.
Figure JPOXMLDOC01-appb-I000015
(In the formulas (2-1) to (2-9), E 1 Represents a hydrogen atom, a hydroxyl group, a methyl group, a methoxy group or an aromatic group having 4 to 50 carbon atoms. ))
In the above formula (2), Y 1 Is Y in formula (1) 1 And preferred examples thereof are also Y in formula (1). 1 These are the same as the specific examples and preferred examples.
In the above formula (2), C 5 ~ C 8 Represents a carbon atom. C 5 -C 8 Bond and C 7 -C 8 Each bond is a carbon-carbon bond in an aromatic ring group.
Ring Ar 03 Is C 5 And C 6 And an aromatic ring having 4 to 50 carbon atoms which may have a substituent. Ring Ar 04 Is C 7 And C 8 And an aromatic ring having 4 to 50 carbon atoms which may have a substituent. The aromatic ring preferably has 4 to 30 carbon atoms, more preferably 4 to 25 carbon atoms, and particularly preferably 6 to 20 carbon atoms.
Examples of the aromatic ring having 4 to 50 carbon atoms include monocyclic aromatic rings such as benzene, diphenyl ether, diphenyl sulfide, benzophenone, and biphenyl, biphenylene, indacene, acenaphthylene, fluorene, phenalene, phenanthrene, anthracene, fluoranthene, triphenylene, and pyrene. , Condensed ring aromatic rings such as naphthacene and perylene, and aromatic rings including heteroatoms such as furan, benzofuran, dibenzofuran, thiophene, benzothiophene, and dibenzothiophene.
The aromatic ring having 4 to 50 carbon atoms may have a substituent. Examples of the substituent include a hydroxyl group, a halogeno group, a cyano group, a carboxy group, a phosphono group, a sulfo group, a formyl group, a mercapto group, An optionally substituted alkyl group having 1 to 20 carbon atoms, an optionally substituted alkoxy group having 1 to 20 carbon atoms, and an optionally substituted carbon group having 1 to 20 carbon atoms. An alkylthio group, an optionally substituted aryl group having 3 to 20 carbon atoms, an optionally substituted aryl group having 3 to 20 carbon atoms, and an optionally substituted group. An arylthio group having 3 to 20 carbon atoms, an acyl group having 2 to 21 carbon atoms which may have a substituent, an aroyl group having 4 to 21 carbon atoms which may have a substituent, and a substituent Optionally having an arylsulfonyl group having 3 to 20 carbon atoms and a substituent And a group selected from alkylsulfonyl groups having 1 to 20 carbon atoms. In order to improve the dispersion and compatibility in the non-aliphatic hydrocarbon polymer electrolyte and enhance the durability of the antioxidant itself, the substituent on the aromatic ring having 4 to 50 carbon atoms is preferably used here. , A halogeno group, a cyano group, a carboxy group, a phosphono group, a sulfo group, a formyl group, a mercapto group, an optionally substituted aryl group having 3 to 20 carbon atoms, and an optionally substituted carbon An aryloxy group having 3 to 20 carbon atoms, an arylthio group having 3 to 20 carbon atoms which may have a substituent, an aroyl group having 4 to 21 carbon atoms which may have a substituent, and a substituent; An arylsulfonyl group having 3 to 20 carbon atoms which may be present, more preferably a cyano group, a carboxy group, a formyl group, an aryl group having 3 to 20 carbon atoms which may have a substituent, or a substituent. Having 3 to 20 carbon atoms A reeloxy group, an optionally substituted arylthio group having 3 to 20 carbon atoms, an optionally substituted aroyl group having 4 to 21 carbon atoms, and an optionally substituted carbon And an arylsulfonyl group having 3 to 20 carbon atoms, particularly preferably an aryl group having 3 to 20 carbon atoms which may have a substituent and an aryl having 3 to 20 carbon atoms which may have a substituent. An oxy group, an optionally substituted arylthio group having 3 to 20 carbon atoms, an optionally substituted aroyl group having 4 to 21 carbon atoms, and an optionally substituted carbon number Examples thereof include 3 to 20 arylsulfonyl groups.
Examples of the halogeno group include a fluoro group, a chloro group, a bromo group, and an iodo group, and preferably a fluoro group.
Examples of the alkyl group having 1 to 20 carbon atoms that may have a substituent include a linear or branched alkyl group. The number of carbon atoms is preferably 1 to 6, more preferably 1 to 4, still more preferably 1 to 4, and particularly preferably 1. Specific examples include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, t-butyl, pentyl, hexyl, heptyl, octyl, decyl, trifluoromethyl group, and the like.
As the alkoxy group having 1 to 20 carbon atoms which may have the above-mentioned substituent, an alkyl group selected from the above-mentioned exemplary group of alkyl groups having 1 to 20 carbon atoms which may have a substituent And a group in which a hydrogen atom of a hydroxyl group is substituted. Preferred examples thereof include a group in which a hydrogen atom of a hydroxyl group is substituted with an alkyl group selected from the above-mentioned preferred examples of the alkyl group.
As the alkylthio group having 1 to 20 carbon atoms which may have the above-described substituent, an alkyl group selected from the exemplified group of alkyl groups having 1 to 20 carbon atoms which may have the aforementioned substituent And a group in which a hydrogen atom of a mercapto group is substituted. Preferred examples thereof include a group in which a hydrogen atom of a mercapto group is substituted with an alkyl group selected from the above-mentioned preferred examples of the alkyl group.
Examples of the aryl group having 3 to 20 carbon atoms which may have the above substituent include phenyl, o-methylphenyl, m-methylphenyl, p-methylphenyl, o-methoxyphenyl, m-methoxyphenyl, p- Monocyclic aryl groups such as methoxyphenyl, o-phenoxyphenyl, m-phenoxyphenyl, p-phenoxyphenyl, o-chlorophenyl, m-chlorophenyl, p-chlorophenyl, biphenyl, 1-naphthyl, 2-naphthyl, 1- Examples thereof include condensed aryl groups such as anthracyl, 2-anthracyl and 4-anthracyl groups, and heteroaryl groups such as 2-thienyl, 3-thienyl, 2-furyl and 3-furyl groups.
As the aryloxy group having 3 to 20 carbon atoms which may have the above-mentioned substituent, an aryl group selected from the exemplified group of aryl groups having 3 to 20 carbon atoms which may have the aforementioned substituent And a group in which a hydrogen atom of a hydroxyl group is substituted. Preferred examples thereof include a group in which a hydrogen atom of a hydroxyl group is substituted with an aryl group selected from the above-mentioned preferred examples of the aryl group.
As the arylthio group having 3 to 20 carbon atoms which may have the above-described substituent, an aryl group selected from the exemplified group of aryl groups having 3 to 20 carbon atoms which may have the aforementioned substituent And a group in which a hydrogen atom of a mercapto group is substituted. Preferred examples thereof include a group in which a hydrogen atom of a mercapto group is substituted with an aryl group selected from the above-mentioned preferred examples of the aryl group.
The acyl group having 2 to 21 carbon atoms which may have the above-mentioned substituent is an alkyl group selected from the above-mentioned exemplified group of alkyl groups having 1 to 20 carbon atoms which may have a substituent. Examples include groups in which a hydrogen atom of a formyl group is substituted. Preferable examples thereof include a group in which a hydrogen atom of a formyl group is substituted with an alkyl group selected from the above-mentioned preferred examples of the alkyl group.
As an aroyl group having 4 to 21 carbon atoms which may have the above-described substituent, an aryl group selected from the exemplified group of aryl groups having 3 to 20 carbon atoms which may have the aforementioned substituent And a group in which a hydrogen atom of the formyl group is substituted. Preferred examples thereof include a group in which a hydrogen atom of the formyl group is substituted with an aryl group selected from the above-mentioned preferred examples of the aryl group.
Examples of the arylsulfonyl group having 3 to 20 carbon atoms which may have the above substituent include phenylsulfonyl, o-methylphenylsulfonyl, m-methylphenylsulfonyl, p-methylphenylsulfonyl, o-methoxyphenylsulfonyl, m -Methoxyphenylsulfonyl, p-methoxyphenylsulfonyl, o-phenoxyphenylsulfonyl, m-phenoxyphenylsulfonyl, p-phenoxyphenylsulfonyl, o-chlorophenylsulfonyl, m-chlorophenylsulfonyl, p-chlorophenylsulfonyl, biphenylsulfonyl group, etc. Condensation of cyclic arylsulfonyl group, 1-naphthylsulfonyl, 2-naphthylsulfonyl, 1-anthracylsulfonyl, 2-anthracylsulfonyl, 4-anthracylsulfonyl group, etc. Examples thereof include heteroarylsulfonyl groups such as a ring arylsulfonyl group, 2-thienylsulfonyl, 3-thienylsulfonyl, 2-furylsulfonyl, and 3-furylsulfonyl group.
In the alkylsulfonyl group having 1 to 20 carbon atoms which may have the above substituent, the preferable carbon number is 1 to 6, more preferably 1 to 4, and still more preferably 1 to 4. Yes, particularly preferably 1. Specific examples include methylsulfonyl, ethylsulfonyl, propylsulfonyl, isopropylsulfonyl, butylsulfonyl, isobutylsulfonyl, sec-butylsulfonyl, t-butylsulfonyl, pentylsulfonyl, hexylsulfonyl, heptylsulfonyl, octylsulfonyl, decylsulfonyl groups, and the like. can give.
In the above formula (2), Z 1 Represents a direct bond or a divalent group represented by any one of formulas (2-1) to (2-9). Preferred are direct bonds, (2-1) to (2-3), and (2-7) to (2-9), and more preferred are direct bonds, (2-2), (2-3), ( 2-7) and (2-8), particularly preferably a direct bond, (2-2), (2-3) and (2-7).
In the above formulas (2-1) to (2-9), E 1 Represents a hydrogen atom, a hydroxyl group, a methyl group, a methoxy group or an aromatic group having 4 to 50 carbon atoms which may have a substituent, preferably a monovalent group having 4 to 50 carbon atoms which may have a substituent. Is an aromatic group. The number of carbon atoms of the aromatic group is preferably 4-30, more preferably 4-20, and particularly preferably 4-12.
E 1 Examples of the aromatic group having 4 to 50 carbon atoms are benzene, toluene, methoxybenzene, biphenyl, naphthalene, anthracene, fluorene, furan, benzofuran, dibenzofuran, thiophene, benzothiophene, dibenzothiophene, thianthrene, phenoxathiin, etc. An aromatic group derived from the aromatic compound of 1 The monovalent aromatic group having 4 to 50 carbon atoms represented by benzene, toluene, methoxybenzene, biphenyl, naphthalene, anthracene, fluorene, furan, benzofuran, dibenzofuran, thiophene, benzothiophene, dibenzothiophene, thianthrene, phenoxy A group obtained by removing one hydrogen atom on an aromatic ring from satiin can be mentioned.
The monovalent aromatic group having 4 to 50 carbon atoms may have a substituent, and includes a hydroxyl group, a halogeno group, a cyano group, a carboxy group, a phosphono group, a sulfo group, a formyl group, a mercapto group, and a substituent. An optionally substituted alkyl group having 1 to 20 carbon atoms, an optionally substituted alkoxy group having 1 to 20 carbon atoms, and an optionally substituted alkylthio group having 1 to 20 carbon atoms An aryl group having 3 to 20 carbon atoms which may have a substituent, an aryloxy group having 3 to 20 carbon atoms which may have a substituent, and 3 carbon atoms which may have a substituent An arylthio group having from 20 to 20, an acyl group having 2 to 21 carbon atoms which may have a substituent, an aroyl group having 4 to 21 carbon atoms which may have a substituent, and a substituent. A good arylsulfonyl group having 3 to 20 carbon atoms and an optionally substituted carbon atom having 1 to Group selected from alkylsulfonyl group 0 and the like. Preferred as a substituent on the monovalent aromatic group having 4 to 50 carbon atoms in order to improve dispersion and compatibility in the non-aliphatic hydrocarbon polymer electrolyte and enhance durability of the antioxidant itself. May have a halogeno group, a cyano group, a carboxy group, a phosphono group, a sulfo group, a formyl group, a mercapto group, an optionally substituted aryl group having 3 to 20 carbon atoms, or a substituent. It has an aryloxy group having 3 to 20 carbon atoms, an arylthio group having 3 to 20 carbon atoms which may have a substituent, an aroyl group having 4 to 21 carbon atoms which may have a substituent, and a substituent. An arylsulfonyl group having 3 to 20 carbon atoms which may be substituted, more preferably a cyano group, a carboxy group, a formyl group, an aryl group having 3 to 20 carbon atoms which may have a substituent, or a substituted group. A group having 3 to 20 carbon atoms which may have a group; An oxy group, an arylthio group having 3 to 20 carbon atoms which may have a substituent, an aroyl group having 4 to 21 carbon atoms which may have a substituent, and a carbon number which may have a substituent An arylsulfonyl group having 3 to 20 carbon atoms, particularly preferably an aryl group having 3 to 20 carbon atoms which may have a substituent, and an aryloxy group having 3 to 20 carbon atoms which may have a substituent. Group, an arylthio group having 3 to 20 carbon atoms which may have a substituent, an aroyl group having 4 to 21 carbon atoms which may have a substituent, and 3 carbon atoms which may have a substituent ~ 20 arylsulfonyl groups.
Here, a halogeno group, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxy group having 1 to 20 carbon atoms which may have a substituent, or a substituent. An alkylthio group having 1 to 20 carbon atoms, an aryl group having 3 to 20 carbon atoms which may have a substituent, an aryloxy group having 3 to 20 carbon atoms which may have a substituent, and a substituent; An optionally substituted arylthio group having 3 to 20 carbon atoms, an optionally substituted acyl group having 2 to 21 carbon atoms, and an optionally substituted aroyl group having 4 to 21 carbon atoms Specific examples and preferred examples of the group selected from an arylsulfonyl group having 3 to 20 carbon atoms which may have a substituent and an alkylsulfonyl group having 1 to 20 carbon atoms which may have a substituent Is the ring Ar 03 Or ring Ar 04 And the same substituents as those on the aromatic ring having 4 to 50 carbon atoms.
Specific examples of the sulfur-containing aromatic compound [B] represented by the above formula (2) include compounds represented by the following (B-001) to (B-018).
Figure JPOXMLDOC01-appb-I000016
Next, the sulfur-containing aromatic compound [C] will be described.
Sulfur-containing aromatic compound [C]: Sulfur-containing aromatic compound represented by the following formula (3).
Figure JPOXMLDOC01-appb-I000017
(In formula (3), Y 1 And Z 1 Are as defined above. C 9 ~ C 12 Each represents a carbon atom. X 3 ~ X 6 Are the same or different and each is a hydrogen atom, a hydroxyl group, a halogeno group, a cyano group, a carboxy group, a phosphono group, a sulfo group, a formyl group, a mercapto group, or an alkyl having 1 to 20 carbon atoms which may have a substituent. Group, an alkoxy group having 1 to 20 carbon atoms which may have a substituent, an alkylthio group having 1 to 20 carbon atoms which may have a substituent, and 3 carbon atoms which may have a substituent An aryl group having 20 to 20 carbon atoms, an aryloxy group having 3 to 20 carbon atoms which may have a substituent, an arylthio group having 3 to 20 carbon atoms which may have a substituent, and a substituent; An acyl group having 2 to 21 carbon atoms, an aroyl group having 4 to 21 carbon atoms which may have a substituent, an arylsulfonyl group having 3 to 20 carbon atoms which may have a substituent, or a substituent Alkyls having 1 to 20 carbon atoms which may have Represents a sulfonyl group. Z 1 X is a direct bond, X 4 And X 5 Are bonded to each other, so that C 10 And C 11 A ring containing may be formed. )
In formula (3), Y 1 And Z 1 Is Y in formula (1) 1 And Z in formula (2) 1 Specific examples and preferred examples thereof are also Y in the formula (1). 1 And Z in formula (2) 1 Specific examples and preferred examples of these can be mentioned.
In the above formula (3), C 9 ~ C 12 Represents a carbon atom. C 9 -C 10 Bond and C 11 -C 12 The bond is a double bond.
In formula (3), X 3 ~ X 6 Are the same or different and each is a hydrogen atom, a hydroxyl group, a halogeno group, a cyano group, a carboxy group, a phosphono group, a sulfo group, a formyl group, a mercapto group, or an alkyl having 1 to 20 carbon atoms which may have a substituent. Group, an alkoxy group having 1 to 20 carbon atoms which may have a substituent, an alkylthio group having 1 to 20 carbon atoms which may have a substituent, and 3 carbon atoms which may have a substituent An aryl group having 20 to 20 carbon atoms, an aryloxy group having 3 to 20 carbon atoms which may have a substituent, an arylthio group having 3 to 20 carbon atoms which may have a substituent, and a substituent; An acyl group having 2 to 21 carbon atoms, an aroyl group having 4 to 21 carbon atoms which may have a substituent, an arylsulfonyl group having 3 to 20 carbon atoms which may have a substituent, or a substituent Alkyls having 1 to 20 carbon atoms which may have Represents a sulfonyl group.
X 3 ~ X 6 Are preferably a hydrogen atom, a hydroxyl group, a halogeno group, a cyano group, a carboxy group, a phosphono group, a sulfo group, a formyl group, a mercapto group, an optionally substituted aryl group having 3 to 20 carbon atoms, An aryloxy group having 3 to 20 carbon atoms which may have a substituent, an arylthio group having 3 to 20 carbon atoms which may have a substituent, and 4 to 4 carbon atoms which may have a substituent 21 an aroyl group, an arylsulfonyl group having 3 to 20 carbon atoms which may have a substituent, and more preferably a hydrogen atom, a cyano group, a carboxy group, a formyl group, or a substituent. An aryl group having 3 to 20 carbon atoms, an aryloxy group having 3 to 20 carbon atoms which may have a substituent, an arylthio group having 3 to 20 carbon atoms which may have a substituent, and a substituent; 4 to 21 carbon atoms that may have An aroyl group, an optionally substituted arylsulfonyl group having 3 to 20 carbon atoms, particularly preferably a hydrogen atom, an optionally substituted aryl group having 3 to 20 carbon atoms, a substituted group An aryloxy group having 3 to 20 carbon atoms which may have a group, an arylthio group having 3 to 20 carbon atoms which may have a substituent, and 4 to 21 carbon atoms which may have a substituent And an arylsulfonyl group having 3 to 20 carbon atoms which may have a substituent.
Here, a halogeno group, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxy group having 1 to 20 carbon atoms which may have a substituent, or a substituent. An alkylthio group having 1 to 20 carbon atoms, an aryl group having 3 to 20 carbon atoms which may have a substituent, an aryloxy group having 3 to 20 carbon atoms which may have a substituent, and a substituent; An optionally substituted arylthio group having 3 to 20 carbon atoms, an optionally substituted acyl group having 2 to 21 carbon atoms, and an optionally substituted aroyl group having 4 to 21 carbon atoms Specific examples and preferred examples of the group selected from an arylsulfonyl group having 3 to 20 carbon atoms which may have a substituent and an alkylsulfonyl group having 1 to 20 carbon atoms which may have a substituent Is the ring Ar 03 Or ring Ar 04 Specific examples of the substituent on the aromatic ring having 4 to 50 carbon atoms and preferred examples thereof are the same.
Z 1 X is a direct bond, X 4 And X 5 May bond to each other to form a ring. As the ring, C 10 And C 11 And a ring having 4 to 50 carbon atoms which may have a substituent is preferable, and the ring preferably has aromaticity. More preferable examples include a ring having 6 to 20 carbon atoms which may have a substituent, and particularly preferable examples include a ring having 6 to 12 carbon atoms which may have a substituent. The aromaticity here means 4n + 2 (n represents an arbitrary integer) in the ring of the cyclic group as described in Morrison Void Organic Chemistry (Middle) 6th Edition (Tokyo Kagaku Dojin). It includes π electrons.
X 4 And X 5 When the cyclic group formed by bonding each other is represented by the following formula (501), the groups represented by the following formulas (501-1) to (501-4) may be exemplified as the cyclic group. it can.
Figure JPOXMLDOC01-appb-I000018
Examples of the substituent on the cyclic group include a hydroxyl group, a halogeno group, a cyano group, a carboxy group, a phosphono group, a sulfo group, a formyl group, a mercapto group, and an optionally substituted alkyl group having 1 to 20 carbon atoms. An optionally substituted alkoxy group having 1 to 20 carbon atoms, an optionally substituted alkylthio group having 1 to 20 carbon atoms, and an optionally substituted substituent having 3 to 3 carbon atoms. 20 aryl groups, aryloxy groups having 3 to 20 carbon atoms which may have substituents, arylthio groups having 3 to 20 carbon atoms which may have substituents, and substituents An acyl group having 2 to 21 carbon atoms, an aroyl group having 4 to 21 carbon atoms which may have a substituent, an arylsulfonyl group having 3 to 20 carbon atoms which may have a substituent, or a substituent; From an alkylsulfonyl group having 1 to 20 carbon atoms that may have The group to be selected. Specific examples and preferred examples thereof are the above Ar. 03 Or Ar 04 Specific examples of the group that may be possessed by the aromatic ring having 4 to 50 carbon atoms and preferred examples thereof, and the like, can be given.
Specific examples of the sulfur-containing aromatic compound [C] represented by the above formula (3) include the following (C-001) to (C-021).
Figure JPOXMLDOC01-appb-I000019
Figure JPOXMLDOC01-appb-I000020
Next, the sulfur-containing aromatic compound [D] will be described.
Sulfur-containing aromatic compound [D]: Sulfur-containing aromatic compound represented by the following formula (4).
Figure JPOXMLDOC01-appb-I000021
(In formula (4), Y 1 And Z 1 Is as defined above. C 13 ~ C 16 Each represents a carbon atom. Ring Ar 05 Is C 15 And C 16 And an aromatic ring having 4 to 50 carbon atoms which may have a substituent. X 7 And X 8 Are the same or different and each is a hydrogen atom, a hydroxyl group, a halogeno group, a cyano group, a carboxy group, a phosphono group, a sulfo group, a formyl group, a mercapto group, or an alkyl having 1 to 20 carbon atoms which may have a substituent. Group, an alkoxy group having 1 to 20 carbon atoms which may have a substituent, an alkylthio group having 1 to 20 carbon atoms which may have a substituent, and 3 carbon atoms which may have a substituent An aryl group having 20 to 20 carbon atoms, an aryloxy group having 3 to 20 carbon atoms which may have a substituent, an arylthio group having 3 to 20 carbon atoms which may have a substituent, and a substituent; An acyl group having 2 to 21 carbon atoms, an aroyl group having 4 to 21 carbon atoms which may have a substituent, an arylsulfonyl group having 3 to 20 carbon atoms which may have a substituent, or a substituent Alkyls having 1 to 20 carbon atoms which may have Represents a sulfonyl group. )
In the above formula (4), Y 1 And Z 1 Is Y in formula (1) 1 And Z in formula (2) 1 Specific examples and preferred examples thereof are also Y in the formula (1). 1 And Z in formula (2) 1 Specific examples and preferred examples of these can be mentioned.
In the above formula (4), C 13 ~ C 16 Represents a carbon atom. C 13 -C 14 The bond is a double bond. C 15 -C 16 The bond is a carbon-carbon bond in the aromatic ring group.
Ring Ar 05 Is C 15 And C 16 And an aromatic ring having 4 to 50 carbon atoms which may have a substituent. Ring Ar 05 Specific examples and preferred examples thereof are the above-mentioned ring Ar 03 Or ring Ar 04 The same thing as the example of can be mentioned.
The aromatic ring having 4 to 50 carbon atoms may have a substituent. Examples of the substituent include a hydroxyl group, a halogeno group, a cyano group, a carboxy group, a phosphono group, a sulfo group, a formyl group, a mercapto group, An optionally substituted alkyl group having 1 to 20 carbon atoms, an optionally substituted alkoxy group having 1 to 20 carbon atoms, and an optionally substituted carbon group having 1 to 20 carbon atoms. An alkylthio group, an optionally substituted aryl group having 3 to 20 carbon atoms, an optionally substituted aryl group having 3 to 20 carbon atoms, and an optionally substituted group. An arylthio group having 3 to 20 carbon atoms, an acyl group having 2 to 21 carbon atoms which may have a substituent, an aroyl group having 4 to 21 carbon atoms which may have a substituent, and a substituent Optionally having an arylsulfonyl group having 3 to 20 carbon atoms and a substituent And a group selected from alkylsulfonyl groups having 1 to 20 carbon atoms. Specific examples and preferred examples thereof include the ring Ar 03 Or ring Ar 04 The same groups as those described above as the group that the aromatic ring having 4 to 50 carbon atoms may have can be exemplified.
In the above formula (4), X 7 And X 8 Are the same or different and each is a hydrogen atom, a hydroxyl group, a halogeno group, a cyano group, a carboxy group, a phosphono group, a sulfo group, a formyl group, a mercapto group, or an alkyl having 1 to 20 carbon atoms which may have a substituent. Group, an alkoxy group having 1 to 20 carbon atoms which may have a substituent, an alkylthio group having 1 to 20 carbon atoms which may have a substituent, and 3 carbon atoms which may have a substituent An aryl group having 20 to 20 carbon atoms, an aryloxy group having 3 to 20 carbon atoms which may have a substituent, an arylthio group having 3 to 20 carbon atoms which may have a substituent, and a substituent; An acyl group having 2 to 21 carbon atoms, an aroyl group having 4 to 21 carbon atoms which may have a substituent, an arylsulfonyl group having 3 to 20 carbon atoms which may have a substituent, or a substituent Alkyls having 1 to 20 carbon atoms which may have A sulfonyl group; X 7 And X 8 Specific examples and preferred examples thereof are the above X 3 ~ X 6 The same thing can be given.
Specific examples of the sulfur-containing aromatic compound [D] represented by the above formula (4) include the following (D-001) to (D-006).
Figure JPOXMLDOC01-appb-I000022
Of the above sulfur-containing aromatic compounds [A] to [D], sulfur-containing aromatic compounds [B] to [D] are preferable, and sulfur-containing aromatic compounds [B] and [D] are more preferable. Particularly preferred is a sulfur-containing aromatic compound [B].
A preferred sulfur-containing aromatic compound [B] is a sulfur-containing aromatic compound represented by the following formula (6).
Figure JPOXMLDOC01-appb-I000023
(In formula (6), Y 1 And Z 1 Is as defined above. R 01 ~ R 08 Are the same or different and each is a hydrogen atom, a hydroxyl group, a halogeno group, a cyano group, a carboxy group, a phosphono group, a sulfo group, a formyl group, a mercapto group, or an alkyl having 1 to 20 carbon atoms which may have a substituent. Group, an alkoxy group having 1 to 20 carbon atoms which may have a substituent, an alkylthio group having 1 to 20 carbon atoms which may have a substituent, and 3 carbon atoms which may have a substituent An aryl group having 20 to 20 carbon atoms, an aryloxy group having 3 to 20 carbon atoms which may have a substituent, an arylthio group having 3 to 20 carbon atoms which may have a substituent, and a substituent; An acyl group having 2 to 21 carbon atoms, an aroyl group having 4 to 21 carbon atoms which may have a substituent, an arylsulfonyl group having 3 to 20 carbon atoms which may have a substituent, or a substituent Alkyls having 1 to 20 carbon atoms which may have Represents a sulfonyl group. )
In the above formula (6), Y 1 And Z 1 Is Y in formula (1) 1 And Z in formula (2) 1 Specific examples and preferred examples thereof are also Y in the formula (1). 1 And Z in formula (2) 1 Specific examples and preferred examples of these can be mentioned.
In the above formula (6), R 01 ~ R 08 Are the same or different and each is a hydrogen atom, a hydroxyl group, a halogeno group, a cyano group, a carboxy group, a phosphono group, a sulfo group, a formyl group, a mercapto group, or an alkyl having 1 to 20 carbon atoms which may have a substituent. Group, an alkoxy group having 1 to 20 carbon atoms which may have a substituent, an alkylthio group having 1 to 20 carbon atoms which may have a substituent, and 3 carbon atoms which may have a substituent An aryl group having 20 to 20 carbon atoms, an aryloxy group having 3 to 20 carbon atoms which may have a substituent, an arylthio group having 3 to 20 carbon atoms which may have a substituent, and a substituent; An acyl group having 2 to 21 carbon atoms, an aroyl group having 4 to 21 carbon atoms which may have a substituent, an arylsulfonyl group having 3 to 20 carbon atoms which may have a substituent, or a substituent Alkyls having 1 to 20 carbon atoms which may have Represents a sulfonyl group.
R 01 ~ R 08 Is preferably a hydrogen atom, a hydroxyl group, a halogeno group, a cyano group, a carboxy group, a phosphono group, a sulfo group, a formyl group, a mercapto group, an optionally substituted aryl group having 3 to 20 carbon atoms, a substituted group An aryloxy group having 3 to 20 carbon atoms which may have a group, an arylthio group having 3 to 20 carbon atoms which may have a substituent, and 4 to 21 carbon atoms which may have a substituent An aroyl group, an arylsulfonyl group having 3 to 20 carbon atoms which may have a substituent, and more preferably a hydrogen atom, a cyano group, a carboxy group, a formyl group, or a substituent. It has an aryl group having 3 to 20 carbon atoms, an aryloxy group having 3 to 20 carbon atoms which may have a substituent, an arylthio group having 3 to 20 carbon atoms which may have a substituent, and a substituent. Alloys with 4 to 21 carbon atoms that may be Group, an optionally substituted arylsulfonyl group having 3 to 20 carbon atoms, particularly preferably a hydrogen atom, an optionally substituted aryl group having 3 to 20 carbon atoms, or a substituent. An aryloxy group having 3 to 20 carbon atoms which may have a substituent, an arylthio group having 3 to 20 carbon atoms which may have a substituent, and an aryloxy group having 4 to 21 carbon atoms which may have a substituent. An aroyl group and an arylsulfonyl group having 3 to 20 carbon atoms which may have a substituent.
Here, it has a halogeno group, an optionally substituted alkyl group having 1 to 20 carbon atoms, an optionally substituted alkoxy group having 1 to 20 carbon atoms, and a substituent. An alkylthio group having 1 to 20 carbon atoms, an aryl group having 3 to 20 carbon atoms which may have a substituent, an aryloxy group having 3 to 20 carbon atoms which may have a substituent, and a substituent An arylthio group having 3 to 20 carbon atoms which may have a substituent, an acyl group having 2 to 21 carbon atoms which may have a substituent, and an aroyl having 4 to 21 carbon atoms which may have a substituent Specific examples of groups selected from a group, an arylsulfonyl group having 3 to 20 carbon atoms which may have a substituent, and an alkylsulfonyl group having 1 to 20 carbon atoms which may have a substituent, and preferred examples thereof As said ring Ar 03 Or ring Ar 04 And the same substituents as those on the aromatic ring having 4 to 50 carbon atoms.
Specific examples of the sulfur-containing aromatic compound represented by the above formula (6) include the above (B-001) to (B-004) and (B-007) to (B-013).
The polymer electrolyte composition of the present invention can be prepared by blending the sulfur-containing aromatic compound and the polymer electrolyte. The blending amount is selected within a range that does not significantly impair characteristics such as ion conductivity of the polymer electrolyte. Preferably, the sulfur-containing aromatic compound is 0.01 to 30 parts by weight, more preferably 0.1 to 20 parts by weight, and more preferably 0.5 to 10 parts by weight with respect to 100 parts by weight of the polymer electrolyte. Is more preferable.
The molecular weight of the sulfur-containing aromatic compound used in the present invention is preferably from 80 to 1300, more preferably from 160 to 1300, from the viewpoint of solubility or dispersibility in the solution during the preparation of the polymer electrolyte composition. 170 to 1000 is even more preferable, and 200 to 800 is particularly preferable. A sulfur-containing aromatic compound having a molecular weight in such a range is preferable because it has high solubility or dispersibility in a solution during the preparation of the polymer electrolyte composition.
When calculating | requiring the molecular weight of a sulfur-containing aromatic compound by analysis, this number average molecular weight measured by a gel permeation chromatography (GPC) method can be used.
The GPC measurement conditions are shown below.
・ Column: TSKgel GMH manufactured by Tosoh Corporation HR -M
-Column temperature: 40 ° C
Mobile phase solvent: N, N-dimethylformamide (LiBr added to 10 mmol / dm3)
・ Solvent flow rate: 0.5 mL / min
・ Detection: Differential refractive index method
Standard material: Tosoh Corporation standard polystyrene A300, A1000, A2500, A5000, F1, F2, F10, F40, F128, F288
In addition, when the analysis by GPC method is difficult, mass spectrometry can be used instead.
<Polymer electrolyte>
Next, the polymer electrolyte contained in the polymer electrolyte composition of the present invention will be described. Examples of the polymer electrolyte include fluorine-based polymer electrolytes having ion exchange groups such as Nafion (registered trademark of DuPont), Aciplex (Asahi Kasei registered trademark) manufactured by Asahi Kasei, and Flemion (Asahi Glass registered trademark) manufactured by Asahi Glass, and aliphatic. Sulfo group (-SO 3 H), carboxyl group (—COOH), phosphone group (—PO) 3 H 2 ), Sulfonylimide group (-SO 2 NHSO 2 -), A hydrocarbon polymer electrolyte into which an ion exchange group such as a phenolic hydroxyl group is introduced is used. Since there is a concern that the hydrocarbon polymer electrolyte has low radical resistance, the polymer electrolyte contained in the polymer electrolyte composition of the present invention is a hydrocarbon polymer electrolyte. The effect of obtaining a polymer electrolyte membrane having radical resistance can be better enjoyed. In addition, the hydrocarbon-based polymer electrolyte is more advantageous than the fluorine-based polymer electrolyte from the viewpoint of heat resistance and the like. Note that the polymer electrolyte may contain a combination of a fluorine-based polymer electrolyte and a hydrocarbon-based polymer electrolyte. The molecular electrolyte is preferably 51% by weight or more, more preferably 70% by weight or more, still more preferably 85% by weight or more, still more preferably 90% by weight or more.
The hydrocarbon-based polymer electrolyte means a polymer electrolyte having a halogen atom content of 15% by weight or less in terms of the weight content ratio of elements constituting the polymer electrolyte. Such hydrocarbon polymer electrolytes have the advantage of being inexpensive compared to the fluorine polymer electrolytes described above, and therefore more preferred, particularly preferred hydrocarbon polymer electrolytes substantially contain halogen atoms. Such a hydrocarbon-based polymer electrolyte does not generate hydrogen halide during the operation of the fuel cell and does not corrode other members.
In addition, a fluorine-type polymer electrolyte means the polymer electrolyte in which a fluorine atom exceeds 15 weight% expressed with the weight content ratio of the element which comprises the said polymer electrolyte. Specific examples include the above-described commercially available fluorine-based polymer electrolytes.
Examples of the ion exchange group include an acidic ion exchange group (that is, a cation exchange group) or a basic ion exchange group (that is, an anion exchange group). From the viewpoint of obtaining high proton conductivity, the ion exchange group is preferably a cation exchange group. By using a polymer electrolyte having a cation exchange group, a fuel cell having further excellent power generation performance can be obtained. Examples of the cation exchange group include a sulfo group (—SO 3 H), carboxyl group (—COOH), phosphone group (—PO) 3 H 2 ), Sulfonylimide group (-SO 2 NHSO 2 -), Phenolic hydroxyl groups and the like. Among these, as the cation exchange group, a sulfo group or a phosphone group is more preferable, and a sulfo group is particularly preferable. These ion exchange groups may be partially or wholly exchanged with metal ions or quaternary ammonium ions to form a salt, but when used as a fuel cell member, It is preferred that substantially all are in the free acid form. These ion exchange groups may be introduced into either or both of the main chain and the side chain of the polymer electrolyte, preferably those introduced into the main chain.
Hereinafter, a hydrocarbon polymer electrolyte having a suitable ion exchange group will be described in detail. Specific examples of such hydrocarbon polymer electrolytes include polymer electrolytes represented by the following (A) to (F).
(A) a polymer electrolyte in which an ion exchange group is introduced into a polymer whose main chain is an aliphatic hydrocarbon;
(B) a polymer electrolyte in which an ion exchange group is introduced into a polymer in which the main chain is composed of an aliphatic hydrocarbon and a part of the hydrogen atoms of the main chain is substituted with fluorine atoms;
(C) a polymer electrolyte in which an ion exchange group is introduced into a polymer having a main chain having an aromatic ring;
(D) a polymer electrolyte in which an ion exchange group is introduced into a polymer whose main chain has an inorganic unit structure such as a siloxane group or a phosphazene group;
(E) An ion exchange group is introduced into a copolymer obtained by combining two or more structural units selected from structural units constituting the main chain of the polymer used for the preparation of the polymer electrolytes (A) to (D). Polymer electrolytes;
(F) A polymer electrolyte in which an acidic compound such as sulfuric acid or phosphoric acid is introduced into a hydrocarbon polymer containing a nitrogen atom in the main chain or side chain by ionic bond
In the following, a polymer electrolyte in which the ion exchange group is a sulfo group is mainly exemplified, but a polymer electrolyte in which the sulfo group is replaced with another ion exchange group may be used.
Examples of the polymer electrolyte (A) include polyvinyl sulfonic acid, polystyrene sulfonic acid, poly (α-methylstyrene) sulfonic acid, and the like.
As the polymer electrolyte (B), a polymer produced by copolymerization of a fluorocarbon vinyl monomer and a hydrocarbon vinyl monomer described in JP-A-9-102322 has a main chain, and a sulfo group. And a sulfonic acid type polystyrene-graft-ethylene-tetrafluoroethylene copolymer (ETFE) having a side chain as a hydrocarbon chain and having a copolymerization mode of graft polymerization. In addition, a copolymer of a fluorocarbon vinyl monomer and a hydrocarbon vinyl monomer obtained by the method described in U.S. Pat. No. 4,012,303 or U.S. Pat. No. 4,605,685, α Further, sulfonic acid type poly (trifluorostyrene) -graft-ETFE obtained by graft polymerization of .beta.,. Beta.-trifluorostyrene and introducing a sulfo group into the solid polymer electrolyte can also be mentioned.
The polymer electrolyte (C) may contain a hetero atom such as an oxygen atom in the main chain. Examples of such a polymer electrolyte include polyether ketone, polyether ether ketone, polysulfone, polyether sulfone, polyether ether sulfone, poly (arylene ether), polyimide, poly ((4-phenoxybenzoyl) -1, 4-phenylene), polyphenylquinoxalene and the like each having a sulfo group introduced therein. Specific examples include sulfoarylated polybenzimidazoles and sulfoalkylated polybenzimidazoles (for example, see JP-A-9-110882). The polymer electrolyte (C) may be a compound in which the main chain is interrupted by a heteroatom such as an oxygen atom. For example, polyetheretherketone, polysulfone, polyethersulfone, poly (arylene ether), Polyimide, poly ((4-phenoxybenzoyl) -1,4-phenylene), polyphenylene sulfide, polyphenylquinoxalen, sulfoarylated polybenzimidazole, sulfoalkylated polybenzimidazole, phosphoalkylated polybenzimidazole, phosphonated Poly (phenylene ether) is mentioned. Such a polymer electrolyte is disclosed in JP-A-9-110882 and J.A. Appl. Polym. Sci. 18, 1969 (1974).
Examples of the polymer electrolyte (D) include those in which a sulfo group is introduced into polyphosphazene. These can be found in Polymer Prep. , 41, no. 1, 70 (2000).
The polymer electrolyte (E) may be any of a random copolymer having a sulfo group introduced therein, an alternating copolymer having a sulfo group introduced therein, and a block copolymer having a sulfo group introduced therein.
Examples of the polymer electrolyte (F) include polybenzimidazole containing phosphoric acid as described in JP-T-11-503262.
In order to obtain a polymer electrolyte membrane having good heat resistance for a fuel cell, an aromatic hydrocarbon polymer electrolyte, particularly one having an aromatic ring in the main chain (that is, the above (C)) is preferable. It is also preferable because of its excellent mechanical strength and high heat resistance. Among the above (C), further, a hydrocarbon system having an aromatic ring constituting the main chain and having an ion exchange group directly bonded to the aromatic ring or indirectly bonded through another atom or atomic group A polymer electrolyte is preferred. In particular, it may have aromatics constituting the main chain, and may further have side chains having aromatic rings, and directly bonded to either the aromatic ring constituting the main chain or the aromatic ring of the side chain. Hydrocarbon polymer electrolytes having ion exchange groups are preferred.
Further, as the polymer electrolyte used in the polymer electrolyte membrane of the present embodiment, a copolymer composed of a structural unit having an ion exchange group and a structural unit having no ion exchange group is used as the polymer electrolyte membrane. It is preferable because it tends to be excellent in water resistance and mechanical strength. The copolymerization mode of these two kinds of structural units may be any of random copolymerization, alternating copolymerization, block copolymerization, and graft copolymerization, preferably random copolymerization, block copolymerization, and graft copolymerization. Random copolymerization and block copolymerization are preferred, and block copolymerization is particularly preferred. A combination of these copolymerization modes may be used.
In the polymer electrolyte applied to the present invention, the amount of ion exchange groups responsible for proton conductivity is preferably 0.5 meq / g or more, more preferably 1.0 meq / g or more, expressed in terms of ion exchange capacity. It is more preferably 2.0 meq / g or more, and particularly preferably 2.7 meq / g or more. Moreover, 5.5 meq / g or less is preferable and 5.0 meq / g or less is more preferable. When the ion exchange capacity is within the above range, there is an advantage that sufficient proton conductivity is expressed as a polymer electrolyte for a fuel cell and the water resistance is relatively good.
As a particularly preferred polymer electrolyte, the following formula (11a), (12a), (13a) or (14a) [hereinafter sometimes referred to as “formulas (11a) to (14a)”]
Figure JPOXMLDOC01-appb-I000024
(Wherein Ar 1 ~ Ar 9 Are the same or different and each represents a divalent aromatic group which has an aromatic ring in the main chain and may further have a side chain having an aromatic ring. At least one of the aromatic ring of the main chain or the aromatic ring of the side chain has an ion exchange group directly bonded to the aromatic ring.
Z and Z ′ are the same or different and are each a group represented by —CO—, —SO— 2 -Represents one of the groups represented by-, X, X ', and X "are the same or different, and represent either a group represented by -O- or a group represented by -S-. Y represents a direct bond or Represents a group represented by the following general formula (15), p represents 0, 1 or 2, and q and r are the same or different and represent 1, 2 or 3.
A structural unit having an ion exchange group represented by:
The following formulas (11b), (12b), (13b) or (14b) [hereinafter sometimes referred to as “formulas (11b) to (14b)”. ]
Figure JPOXMLDOC01-appb-I000025
(Wherein Ar 11 ~ Ar 19 Represent the same or different divalent aromatic groups which may have a substituent as a side chain. Z and Z ′ are the same or different and are each a group represented by —CO—, —SO— 2 -Represents one of the groups represented by-, X, X ', and X "are the same or different, and represent either a group represented by -O- or a group represented by -S-. Y represents directly or below. And represents a group represented by the general formula (15), p ′ represents 0, 1 or 2, and q ′ and r ′ represent the same or different and each represents 1, 2 or 3.)
A structural unit having no ion-exchange group, and the copolymerization mode is random copolymerization, block copolymerization, block copolymerization or graft copolymerization, or a copolymerization mode thereof. A combined polymer electrolyte is exemplified.
Figure JPOXMLDOC01-appb-I000026
(Wherein R 1 And R 2 Are the same or different and each has a hydrogen atom, an optionally substituted alkyl group having 1 to 20 carbon atoms, an optionally substituted alkoxy group having 1 to 20 carbon atoms, or a substituent. An aryl group having 6 to 20 carbon atoms which may be substituted, an aryloxy group having 6 to 20 carbon atoms which may have a substituent, or an acyl group having 2 to 21 carbon atoms which may have a substituent Represents R 1 And R 2 And may be linked to form a ring. R 1 And R 2 Examples of the group of the formula (15) having a ring formed by linking with each other include a divalent cyclic hydrocarbon group having 5 to 20 carbon atoms such as a cyclohexylidene group. )
Ar in the formulas (11a) to (14a) 1 ~ Ar 9 Represents a divalent aromatic group. Here, the divalent aromatic group is a residue obtained by removing two hydrogen atoms from an aromatic compound. Hereinafter, the term “divalent aromatic group” is used in the same sense. Examples of the divalent aromatic group include divalent monocyclic aromatic groups such as 1,3-phenylene and 1,4-phenylene, 1,3-naphthalenediyl, 1,4-naphthalenediyl, 1, Divalent condensed aromatic groups such as 5-naphthalenediyl, 1,6-naphthalenediyl, 1,7-naphthalenediyl, 2,6-naphthalenediyl, 2,7-naphthalenediyl, pyridinediyl, quinoxalinediyl, Thiophenediyl, pyrrole, 2H-pyrrole, imidazole, pyrazole, isoxazole, pyridine, pyrazine, pyrimidine, pyridazine, indolizine, isoindole, 3H-indole, indole, 1H-indazole, purine, 4H-quinolidine, quinoline, isoquinoline, Phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, Lysine, carbazole, carboline, phenanthridine, acridine, perimidine, phenanthroline, phenazine, furazane, phenoxazine, pyrrolidine, pyrroline, imidazoline, imidazolidine, pyrazolidine, pyrazoline, piperidine, piperazine, indoline, isoindoline, quinuclidine, oxazole, benzo Heterofragrance obtained by removing two hydrogen atoms on the aromatic ring from at least one selected from the group consisting of oxazole, 1,3,5-triazine, bromine, tetrazole, tetrazine, triazole, phenalsazine, benzimidazole, and benzotriazole Or a heteroaromatic group containing at least one structure selected from the group consisting of structures represented by the following formulas (N-01) to (N-07). A divalent monocyclic aromatic group is preferably a divalent condensed ring aromatic group, and more preferably a divalent monocyclic aromatic group.
Figure JPOXMLDOC01-appb-I000027
Further, Ar in the formulas (11a) to (14a) 1 ~ Ar 9 The hydrogen atom on the aromatic ring of the aromatic group represented by formula (1) is an optionally substituted alkyl group having 1 to 20 carbon atoms and an optionally substituted alkoxy group having 1 to 20 carbon atoms. Group, an aryl group having 6 to 20 carbon atoms which may have a substituent, an aryloxy group having 6 to 20 carbon atoms which may have a substituent or a carbon number which may have a substituent It may be substituted with 2 to 21 acyl groups.
Ar in the formulas (11a) to (14a) 1 Ar 9 The aromatic group represented by has at least one ion-exchange group in the aromatic ring. These ion exchange groups may be introduced into either or both of the main chain and the side chain of the polyelectrolyte, but preferably an aromatic group having at least one ion exchange group in the aromatic ring constituting the main chain. It is a family group. As the ion exchange group, an acidic ion exchange group is preferable as described above, and among the acidic ion exchange groups, a sulfo group or a phosphone group is more preferable, and a sulfo group is particularly preferable.
Moreover, as an example of a structural unit having an ion exchange group represented by the formula (14a), a structural unit represented by the following formula (14a-1) can be given.
Figure JPOXMLDOC01-appb-I000028
(In the above formula (14a-1), Ar 110 , Ar 120 , Ar 130 Each independently represents a divalent aromatic group, and a hydrogen atom on the aromatic ring may be substituted with a fluorine atom. Y is -CO-, -SO 2 -, -SO-, -CONH-, -COO-,-(CF 2 ) u000 -(U000 is an integer of 1 to 10), -C (CF 3 ) 2 -Or direct binding. Z 000 -O-, -S-, direct bond, -CO-, -SO 2 -, -SO-,-(CH 2 ) 1000 -(1000 is an integer from 1 to 10) or -C (CH 3 ) 2 -Is shown. R 110 Is a direct bond, —O (CH 2 ) p000 -, -O (CF 2 ) p000 -,-(CH 2 ) p000 -Or-(CF 2 ) p000 -(P000 represents an integer of 1 to 12). R 120 , R 130 Each independently represents a hydrogen atom, an alkali metal atom or a hydrocarbon group. However, all R contained in the above formula 120 And R 130 At least one of them is a hydrogen atom. x100 is an integer of 0-4. x200 is an integer of 1 to 5. a000 is an integer of 0 to 1. b000 represents an integer of 0 to 3. )
Ar in the formula (14a-1) 110 , Ar 120 And Ar 130 Represents a divalent aromatic group. Examples of such a divalent aromatic group include Ar in the formulas (11a) to (14a). 1 ~ Ar 9 And the same divalent aromatic groups.
R 120 , R 130 Each independently represents a hydrogen atom, an alkali metal atom or a hydrocarbon group. Examples of the alkali metal atom include lithium, sodium, potassium, rubidium, cesium, and rubidium. Examples of the hydrocarbon group include a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, and a tert-butyl group. 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, Adamantylmethyl group, bicyclo [2.2 1] linear hydrocarbon groups such as heptyl methyl group, a branched hydrocarbon group, an alicyclic hydrocarbon group, such as a hydrocarbon group having a heterocyclic ring. Of 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 more preferable. . R 120 , R 130 Is preferably a hydrogen atom.
The structural unit represented by the above formula (14a-1) is preferably a structural unit represented by the following formula (14a-2).
Figure JPOXMLDOC01-appb-I000029
(In formula (14a-2), Y 001 Is -CO-, -SO 2 -, -SO-, -CONH-, -COO-,-(CF 2 ) L- (where l is an integer from 1 to 10), -C (CF 3 ) 2 -Represents at least one structure selected from the group consisting of 001 Is a direct bond or-(CH 2 ) L- (where l is an integer from 1 to 10), -C (CH 3 ) 2 -, -O-, -S-, -CO-, -SO 2 And at least one structure selected from the group consisting of: 001 Is -SO 3 H or -O (CH 2 PSO 3 H or -O (CF 2 PSO 3 An aromatic group having a substituent represented by H is shown. p represents an integer of 1 to 12, m001 represents an integer of 0 to 10, n001 represents an integer of 0 to 10, and k001 represents an integer of 1 to 4. )
Specific examples of the structural unit having an ion exchange group represented by the above formula (14a-2) include structural units represented by the following formulas (4a-13) to (4a-20).
Figure JPOXMLDOC01-appb-I000030
Represents an aromatic group. Examples of such divalent aromatic groups include bivalent monocyclic aromatic groups such as 1,3-phenylene and 1,4-phenylene, 1,3-naphthalenediyl, and 1,4-naphthalenediyl. 1,5-naphthalenediyl, 1,6-naphthalenediyl, 1,7-naphthalenediyl, 2,6-naphthalenediyl, 2,7-naphthalenediyl and the like divalent condensed aromatic groups such as pyridinediyl, Quinoxalinediyl, thiophenediyl, pyrrole, 2H-pyrrole, imidazole, pyrazole, isoxazole, pyridine, pyrazine, pyrimidine, pyridazine, indolizine, isoindole, 3H-indole, indole, 1H-indazole, purine, 4H-quinolidine, quinoline , Isoquinoline, phthalazine, naphthyridine, quinoxaline, quinazoline, syn Phosphorus, pteridine, carbazole, carboline, phenanthridine, acridine, perimidine, phenanthroline, phenazine, furazane, phenoxazine, pyrrolidine, pyrroline, imidazoline, imidazolidine, pyrazolidine, pyrazoline, piperidine, piperazine, indoline, isoindoline, quinuclidine, oxazole , Obtained by removing two hydrogen atoms on at least one aromatic ring selected from the group consisting of benzoxazole, 1,3,5-triazine, bromine, tetrazole, tetrazine, triazole, phenalsazine, benzimidazole, and benzotriazole A heteroaromatic group, and a heteroaromatic group containing at least one structure selected from the group consisting of structures represented by the following formulas (N-01) to (N-07). . A divalent monocyclic aromatic group is preferably a divalent condensed ring aromatic group, and more preferably a divalent monocyclic aromatic group.
Figure JPOXMLDOC01-appb-I000031
Ar 11 ~ Ar 19 The hydrogen atom on the aromatic ring of the aromatic group represented by the formula is a fluorine atom, a formyl group, a cyano group, an optionally substituted alkyl group having 1 to 20 carbon atoms, or a substituent. An alkoxy group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms which may have a substituent, an aryloxy group having 6 to 20 carbon atoms which may have a substituent, or a substituent It may be substituted with an acyl group having 2 to 21 carbon atoms which may have The “optionally substituted” substituent here does not include an ion exchange group.
Here, the aforementioned divalent aromatic group (Ar in the formulas (11a) to (14a)) 1 ~ Ar 9 And Ar in the formulas (11b) to (14b) 11 ~ Ar 19 The substituents of the aromatic group represented by
Examples of the optionally substituted alkyl group having 1 to 20 carbon atoms include methyl group, ethyl group, butyl group, n-propyl group, isopropyl group, n-pentyl group, and 2,2-dimethylpropyl group. An alkyl group having 1 to 20 carbon atoms such as a group, a cyclopentyl group, an n-hexyl group, a cyclohexyl group, a 2-methylpentyl group, a 2-ethylhexyl group, a nonyl group, a dodecyl group, a hexadecyl group, an octadecyl group, and an icosyl group; These groups are substituted with fluorine atoms, hydroxyl groups, nitrile groups, amino groups, methoxy groups, ethoxy groups, isopropyloxy groups, phenyl groups, naphthyl groups, phenoxy groups, naphthyloxy groups, etc., and the total number of carbon atoms is 20 or less. The alkyl group which is is mentioned.
Examples of the alkoxy group having 1 to 20 carbon atoms which may have a substituent include, for example, a methoxy group, an ethoxy group, a butoxy group, an n-propoxy group, an isopropoxy group, an n-pentoxy group, and 2,2-dimethyl. An alkoxy group having 1 to 20 carbon atoms such as a propoxy group, a cyclopentoxy group, an n-hexoxy group, a cyclohexoxy group, a 2-methylpentoxy group, a 2-ethylhexoxy group, a dodecyloxy group, a hexadecyloxy group, and an icosyloxy group; And these groups are substituted with fluorine atoms, hydroxyl groups, nitrile groups, amino groups, methoxy groups, ethoxy groups, isopropyloxy groups, phenyl groups, naphthyl groups, phenoxy groups, naphthyloxy groups, etc. The following alkoxy groups are mentioned.
Examples of the aryl group having 6 to 20 carbon atoms which may have a substituent include aryl groups such as a phenyl group, a naphthyl group, a phenanthrenyl group, and an anthracenyl group, and these groups include a fluorine atom, a hydroxyl group, and a nitrile. Group, amino group, methoxy group, ethoxy group, isopropyloxy group, phenyl group, naphthyl group, phenoxy group, naphthyloxy group and the like are substituted, and aryl groups having a total carbon number of 20 or less can be mentioned.
Examples of the aryloxy group having 6 to 20 carbon atoms which may have a substituent include aryloxy groups such as a phenoxy group, a naphthyloxy group, a phenanthrenyloxy group, and an anthracenyloxy group, and the like. Are substituted with fluorine atom, hydroxyl group, nitrile group, amino group, methoxy group, ethoxy group, isopropyloxy group, phenyl group, naphthyl group, phenoxy group, naphthyloxy group, etc. A certain aryloxy group is mentioned.
Examples of the acyl group having 2 to 21 carbon atoms which may have a substituent include an acetyl group, a propionyl group, a butyryl group, an isobutyryl group, a pivaloyl group, a benzoyl group, a 1-naphthoyl group, and a 2-naphthoyl group. Acyl groups having 2 to 20 carbon atoms, and fluorine, hydroxyl, nitrile, amino, methoxy, ethoxy, isopropyloxy, phenyl, naphthyl, phenoxy, naphthyloxy, etc. And an acyl group having a total carbon number of 21 or less.
Aromatic ring substituents include aryl groups such as phenyl group, naphthyl group, phenanthrenyl group, anthracenyl group, aryloxy groups such as phenoxy group, naphthyloxy group, phenanthrenyloxy group, anthracenyloxy group, benzoyl group, An acyl group having an aromatic ring such as a 1-naphthoyl group or a 2-naphthoyl group is preferred because the heat resistance of the polymer tends to be good, and a more practical fuel cell member can be obtained.
In a polymer electrolyte including a polymer having an acyl group having an aromatic ring as an aromatic ring substituent, two structural units having the acyl group are adjacent to each other, and the acyl groups in the two structural units are bonded to each other. In this way, after the acyl groups are bonded to each other, a rearrangement reaction may occur. In addition, whether or not such a reaction that the aromatic ring substituents are bonded to each other or a rearrangement reaction is generated after the bonding occurs is, for example, 13 This can be confirmed by measuring the C-nuclear magnetic resonance spectrum.
The hydrocarbon-based polymer electrolyte has a structural unit having an ion exchange group and a structural unit not having an ion exchange group, and a dense phase of the structural unit having an ion exchange group forms a continuous phase in the film thickness direction. If it can be formed, it is preferable because there is an advantage that a polymer electrolyte membrane having more excellent proton conductivity can be obtained.
In the present invention, suitable polymer electrolytes are represented by the structural units having an ion exchange group composed of the structural units represented by the formulas (11a) to (14a) and the formulas (11b) to (14b). And a structural unit having no ion exchange group. Further preferred examples of the combination of the structural unit having an ion exchange group and the structural unit having no ion exchange group include the combinations of structural units shown in <a> to <m> in Table 1 below.
Figure JPOXMLDOC01-appb-T000032
 More preferably, <b>, <c>, <d>, <g>, <h>, <i>, <j>, <l>, or <m>, and even more preferably <g> , <H>, <l>, or <m>, <g>, <h>, <l> are particularly preferable.
Examples of suitable copolymers include one or more structural units selected from the group of structural units having an ion exchange group shown below, and a group of structural units having no ion exchange group shown below. And a copolymer composed of one or more structural units. In addition, these structural units may be directly bonded or may be bonded with an appropriate atom or atomic group. As a typical example of an atom or an atomic group for bonding structural units here, a divalent aromatic group, an oxygen atom, a sulfur atom, a carbonyl group, a sulfonyl group, or a divalent group formed by combining these is used. I can give you.
(Structural unit having an ion exchange group)
Figure JPOXMLDOC01-appb-I000033
Figure JPOXMLDOC01-appb-I000034
(Structural unit without ion exchange group)
Figure JPOXMLDOC01-appb-I000035
Figure JPOXMLDOC01-appb-I000036
Figure JPOXMLDOC01-appb-I000037
In the formulas (4b-15) to (4b-32), r000 represents 0 or an integer of 1 or more. r000 is preferably 100 or less, more preferably 1 or more and 80 or less.
Among the examples described above, the formula representing the structural unit having an ion exchange group includes (4a-1) and / or (4a-2) and / or (4a-3) and / or (4a-4). And / or (4a-5) and / or (4a-6) and / or (4a-7) and / or (4a-8) and / or (4a-9) and / or ( 4a-10) and / or (4a-11) and / or (4a-12) are preferred, and (4a-10) and / or (4a-11) and / or (4a-12) are more. (4a-11) and / or (4a-12) are particularly preferable.
Among the above examples, the formula representing the structural unit having no ion exchange group includes (4b-1) and / or (4b-2) and / or (4b-3) and / or (4b-4). ) And / or (4b-5) and / or (4b-6) and / or (4b-7) and / or (4b-8) and / or (4b-9) and / or (4b-10) and / or (4b-11), (4b-12) and / or (4b-13) and / or (4b-14) are preferred, (4b-2) and (4b-3) and / or (4b-9) and / or (4b-10) and / or (4b-13) and / or (4b-14) are more preferable, (4b -2) and / or (4b-3) and / or (4b-13) and / or (4b-14) is even more Mashiku, (4b-2) and / or (4b-3) and / or, particularly preferably (4b-14).
The hydrocarbon-based polymer electrolyte has a structural unit having an ion exchange group and a structural unit not having an ion exchange group. The copolymerization mode of these two structural units is random copolymerization, Any of alternating copolymerization, block copolymerization, and graft copolymerization may be used, or a combination of these copolymerization modes may be used. Random copolymerization, block copolymerization, and graft copolymerization are preferred, random copolymerization and block copolymerization are more preferred, and block copolymerization is particularly preferred.
In the present invention, suitable block copolymers are represented by the above-mentioned formulas (11b) to (14b) and segments having an ion exchange group, which are composed of structural units represented by the above formulas (11a) to (14a). And a segment having substantially no ion exchange group. Further, combinations of the structural unit constituting the segment having a suitable ion exchange group and the structural unit constituting the segment having substantially no ion exchange group are shown in <a> to <m> in Table 2 below. A combination of segments can be given.
Figure JPOXMLDOC01-appb-T000038
 More preferably, <b>, <c>, <d>, <g>, <h>, <i>, <j>, <l>, or <m>, and even more preferably <g> , <H>, <l>, or <m>, <g>, <h>, <l> are particularly preferable.
Among the above examples, as a formula representing a structural unit used for a repeating unit constituting a segment having an ion exchange group, (4a-1) and / or (4a-2) and / or (4a-3) and / or (4a-4) and / or (4a-5) and / or (4a-6) and / or (4a-7) and / or (4a-8) and / or (4a-9) and / or (4a -10) and / or (4a-11) and / or (4a-12) are preferred,
(4a-10) and / or (4a-11) and / or (4a-12) are more preferred, and (4a-11) and / or (4a-12) are particularly preferred.
One preferred form of the block copolymer according to the present invention is that the main chain of the segment having an ion exchange group has a polyarylene structure in which a plurality of aromatic rings are directly connected. The structural unit of such a segment is preferably the above-mentioned (4a-10) and / or (4a-11) and / or (4a-12) and / or (4a-13) and / or (4a-14) And / or (4a-15) and / or (4a-16) and / or (4a-17) and / or (4a-18) and / or (4a-19) and / or (4a-20) More preferred is (4a-10) and / or (4a-11) and / or (4a-12), and particularly preferred is (4a-11) and / or (4a-12).
A polymer electrolyte having such a structural unit as a segment containing a repeating unit (that is, a segment having an ion exchange group), in particular, a polymer electrolyte having a segment consisting of such a repeating unit has excellent ion conductivity. Since the segment has a polyarylene structure, the chemical stability tends to be relatively good.
Here, the “polyarylene structure” is a form in which the aromatic rings constituting the main chain are directly bonded to each other. Specifically, the total number of bonds between the aromatic rings is 100%. In some cases, the direct bond ratio is preferably 80% or more, more preferably 90% or more, and even more preferably 95% or more. In addition, forms other than the form couple | bonded by the direct bond are forms in which aromatic rings are couple | bonded with a bivalent atom or a bivalent atomic group.
As a formula representing a structural unit used as a repeating unit constituting a segment having no ion exchange group, (4b-1) and / or (4b-2) and / or (4b-3) and / or (4b- 4) and / or (4b-5) and / or (4b-6) and / or (4b-7) and / or (4b-8) and / or (4b-9) and / or (4b-10) And / or (4b-11) and / or (4b-12) and / or (4b-13) and / or (4b-14) are preferred, (4b-2) and / or (4b-3) ) And / or (4b-9) and / or (4b-10) and / or (4b-13) and / or (4b-14) are more preferred, (4b-2) and / or (4b-3) And / or (4b-13) and / or (4b-14) are even more preferred. , (4b-2) and / or (4b-3) and / or (4b-14) is particularly preferred.
In addition, the segment having an ion exchange group and the segment having substantially no ion exchange group may be directly bonded or may be connected by an appropriate atom or atomic group. As typical examples of the atoms or atomic groups connecting the segments here, a divalent aromatic group, an oxygen atom, a sulfur atom, a carbonyl group, a sulfonyl group, or a divalent group formed by combining these is given. be able to.
Examples of a suitable block copolymer include a segment containing one or more structural units selected from the group of structural units having an ion exchange group shown above (ie, a segment having an ion exchange group), and the above A block copolymer comprising a segment containing one or more structural units selected from the group of structural units having no ion-exchange groups shown in (1), and a segment having substantially no ion-exchange groups. I can give you.
Here, the “segment having an ion exchange group” means a segment in which an ion exchange group is contained in an average of 0.5 or more per structural unit constituting the segment, and per structural unit It is more preferable that the average number of ion exchange groups is 1.0 or more.
On the other hand, the “segment having substantially no ion-exchange group” means a segment having an average number of ion-exchange groups of less than 0.5 per structural unit constituting the segment. The average number of ion exchange groups is more preferably 0.1 or less, and even more preferably 0.05 or less on average.
Typically, a block copolymer in a form in which a segment having an ion exchange group and a segment having substantially no ion exchange group are bonded by a direct bond or bonded by an appropriate atom or atomic group. is there.
The degree of polymerization of the segment composed of one or more structural units selected from the structural units represented by the above formulas (11a) to (14a) is 2 or more, preferably 3 or more, more preferably 5 or more, and more preferably 10 or more. Further preferred. Further, the polymerization degree of the segment is preferably 1000 or less, and preferably 500 or less. If the degree of polymerization is 2 or more, preferably 5 or more, sufficient proton conductivity is expressed as a polymer electrolyte for a fuel cell, and if the degree of polymerization is 1000 or less, the advantage is that manufacture is easier. There is.
In addition, the degree of polymerization of a segment composed of a structural unit selected from structural units represented by formulas (11b) to (14b) is 1 or more, preferably 2 or more, and more preferably 3 or more. Further, the polymerization degree of the segment is preferably 100 or less, more preferably 90 or less, and still more preferably 80 or less. Within such a range, the polymer electrolyte for fuel cells is preferable because it has sufficient mechanical strength and is easy to produce.
Further, the molecular weight of the hydrocarbon-based polymer electrolyte used in the present invention is preferably 5000 to 1,000,000, more preferably 10,000 to 800,000, and more preferably 10,000 to 600,000 in terms of polystyrene-reduced number average molecular weight. More preferably, it is more preferably 15,000 to 400,000. By using a polymer electrolyte having a molecular weight in such a range, a polymer electrolyte membrane prepared by a method described later tends to stably maintain the shape of the membrane. The number average molecular weight is measured by gel permeation chromatography (GPC).
<Polymer electrolyte membrane>
The polymer electrolyte membrane of the present invention includes a polymer electrolyte composition containing the above sulfur-containing aromatic compound and a polymer electrolyte. The polymer electrolyte membrane is preferably a polymer electrolyte membrane produced by a solution casting method including the following steps (i) to (iv).
(I) a step of preparing a polymer electrolyte solution by dissolving the polymer electrolyte composition as described above in an organic solvent capable of dissolving the polymer electrolyte and / or the polymer electrolyte composition;
(Ii) A step of casting the polymer solution obtained in (i) above on a supporting substrate having a relatively smooth surface, and forming a polymer electrolyte casting film on the supporting substrate. ;
(Iii) removing the organic solvent from the polymer electrolyte casting film formed on the support substrate in (ii) to form a polymer electrolyte film on the support substrate;
(Iv) A step of separating the support substrate and the polymer electrolyte membrane after performing the step (iii)
Here, the steps (i) to (iv) relating to the solution casting method will be sequentially described.
First, in (i), a polymer electrolyte solution is prepared as described above. Here, as an organic solvent used for preparing the polymer electrolyte solution, a solvent capable of dissolving one or more polymer electrolytes to be used is selected. Moreover, when using components, such as an additive, in addition to a polymer electrolyte and / or a polymer electrolyte composition, the solvent which can melt | dissolve these other components together is preferable.
The organic solvent used is a solvent that can dissolve the polyelectrolyte and / or polyelectrolyte composition to be used. Preferably, the polyelectrolyte and / or polyelectrolyte composition is added at 1% by weight at 25 ° C. It is an organic solvent that can be dissolved at the above concentrations. More preferably, an organic solvent capable of dissolving the polymer electrolyte and / or the polymer electrolyte composition at a concentration of 5 to 50% by weight is used.
Further, the organic solvent needs to be volatile enough to be removed by heat treatment after the polymer electrolyte casting film is formed on the support substrate. However, the organic solvent preferably contains at least one organic solvent having a boiling point of 150 ° C. or higher at 101.3 kPa (1 atm). When only an organic solvent having a boiling point of less than 150 ° C. is used as an organic solvent capable of dissolving the polymer electrolyte and / or polymer electrolyte composition, the organic solvent is removed from the polymer electrolyte casting membrane in the step (iii) described later. If an attempt is made to form a polymer electrolyte membrane, the formed polymer electrolyte membrane may have irregular appearance defects. This is because, in an organic solvent having a boiling point of less than 150 ° C., the organic solvent suddenly volatilizes from the polymer electrolyte casting membrane.
Suitable organic solvents for the preparation of the polymer electrolyte solution include dimethylformamide (DMF), dimethylacetamide (DMAc), N-methyl-2-pyrrolidone (NMP), dimethyl sulfoxide (DMSO), and γ-butyrolactone (GBL). Aprotic polar solvents such as, chlorinated solvents such as dichloromethane, chloroform, 1,2-dichloroethane, chlorobenzene, dichlorobenzene, alcohols such as methanol, ethanol, propanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene Examples include alkylene glycol monoalkyl ethers such as glycol monomethyl ether and propylene glycol monoethyl ether. These can be used alone, or two or more organic solvents can be mixed and used. Among these, an organic solvent containing an aprotic polar solvent is preferable, and an organic solvent substantially consisting of an aprotic polar solvent is particularly preferable. The “organic solvent substantially consisting of an aprotic polar solvent” as used herein does not exclude the presence of moisture or the like unintentionally contained. The aprotic polar solvent has an advantage that the affinity for the supporting substrate is relatively small and the aprotic polar solvent is hardly absorbed by the supporting substrate. In addition, in terms of the high solubility of the block copolymer which is the preferred polymer electrolyte described above, among the aprotic polar solvents, DMSO, DMF, DMAc, NMP, GBL or two or more selected from these are used. Mixed solvents are preferred.
Next, process (ii) is demonstrated.
This step is a step in which the polymer electrolyte solution obtained in the step (i) is cast-coated on a supporting substrate. As the casting coating method, various means such as a roller coating method, a spray coating method, a curtain coating method, a slot coating method, a screen printing method and the like can be used. Means for shaping the polymer electrolyte solution to a predetermined width and thickness can be given by the obtained mold. Thus, the polymer electrolyte casting film formed on the support substrate has a film shape because a part of the organic solvent in the polymer electrolyte solution volatilizes during coating. In this case, the thickness of the polymer electrolyte casting membrane is preferably 3 to 50 μm. In order to obtain a polymer electrolyte casting film having such a film thickness, the polymer electrolyte concentration of the polymer electrolyte solution to be used, the coating amount of the coating apparatus, etc. may be appropriately adjusted. Moreover, when this support base material is a base material which runs continuously, it can also be adjusted by the running speed of the support base material.
The supporting substrate used in the step (ii) has sufficient durability against the polymer electrolyte solution used for the casting coating, and also durable against the processing conditions in the step (iii) described later. A material made of a material having is selected. In this case, the durability means that the supporting base material itself is not substantially dissolved by the polymer electrolyte solution, and that the supporting base material itself does not swell or shrink depending on the processing conditions of step (iii). Means something good.
Examples of the supporting substrate include glass plates; metal foils such as SUS foil and copper foil; and plastic films such as polyethylene terephthalate (PET) film and polyethylene naphthalate (PEN) film. In addition, the plastic film may be subjected to surface treatment such as UV treatment, mold release treatment, embossing treatment, and the like within a range that does not significantly impair the durability as described above.
Next, step (iii) will be described.
In this step, the organic solvent contained in the polymer electrolyte casting film formed on the support substrate in the step (ii) is removed to form a polymer electrolyte membrane on the support substrate. It is. For such removal, drying or washing with a washing solvent is recommended. It is more preferable to combine the drying and washing to remove the organic solvent. When the drying and washing are combined, the polymer formed on the support substrate is first dried. It is particularly preferable to perform washing with a washing solvent after removing almost all of the organic solvent contained in the electrolyte casting membrane.
Here, it will be described in detail that the drying and washing, which are suitable methods as the step (iii), are performed in this order. In order to dry and remove the organic solvent from the polymer electrolyte casting membrane formed on the support substrate obtained through the step (ii), treatment such as heating, decompression, and ventilation can be employed. Heat treatment is preferable in terms of good properties and easy operation. In this case, the support substrate (hereinafter, sometimes referred to as “first laminated film”) on which the polymer electrolyte casting film is formed is heat-treated by direct heating, hot air contact, or the like. Hot air treatment is particularly preferable in that the polymer electrolyte in the polymer electrolyte casting membrane is not significantly impaired. For example, when the first laminated film has a long shape and the long first laminated film is continuously processed, the first laminated film may be passed through a drying furnace. . The drying furnace at this time is warm air set at a temperature in the range of 40 to 150 ° C., preferably 50 to 140 ° C., along the direction perpendicular to the passing direction of the first laminated film and / or the facing direction. Blow. By doing this, the volatile component such as the organic solvent is dried (evaporated) from the polymer electrolyte casting film on the support substrate, and the second laminate in which the polymer electrolyte film is formed on the support substrate. A film is formed.
Since the polymer electrolyte membrane of the second laminated film thus obtained still contains a slight amount of organic solvent, this organic solvent is washed with a washing solvent. By washing with a washing solvent, a polymer electrolyte membrane excellent in appearance and the like can be easily obtained. When a mixed solvent composed of DMSO, DMF, DMAc, NMP, GBL, or a combination thereof, which is a suitable organic solvent in the preparation of the polymer electrolyte solution, is used as the cleaning solvent, pure water, particularly ultrapure water. Is preferably used.
As described above, when the first laminated film is long and continuously running, the second laminated film formed continuously through the drying furnace is filled with, for example, a cleaning solvent. It can wash | clean by letting it pass through the washing tank which carried out. Moreover, after winding the 2nd laminated | multilayer film continuously formed through the drying furnace on a suitable core and making it a winding body, this winding body is transferred to the washing | cleaning apparatus which bears a cleaning process. It is also possible to perform cleaning in such a manner that the second laminated film is sent from the transferred winding body to the cleaning tank. By doing so, the organic solvent content of the polymer electrolyte membrane in the second laminated film can be further reduced.
The polymer electrolyte membrane can be obtained by removing the supporting substrate from the second laminated film thus obtained by peeling or the like. Since this polymer electrolyte membrane is obtained by a suitable solution casting method, it becomes a substantially non-porous membrane. Here, “substantially non-porous” means that minute through holes such as voids are not formed in the polymer electrolyte membrane. However, the polymer electrolyte membrane may be a membrane having such a void as long as it is a small amount of voids or a small diameter void that does not hinder the operation of the fuel cell.
Further, in the polymer electrolyte membrane production by the solution casting method described above, the case where the supporting base material is continuously running has been described. Of course, even if a single-wafer supporting base material is used, the polymer electrolyte membrane is not used. Obtainable. In this case, the polymer electrolyte solution coated on the supporting substrate of the single wafer can be removed in a suitable drying furnace, the organic solvent can be removed, and the sheet thus obtained The second laminated film of leaves can be cleaned by immersing it in a cleaning tank equipped with a cleaning solvent.
Moreover, after removing the supporting substrate, the second laminated film after washing may be subjected to dry removal of the remaining or adhering washing solvent, or the second laminated film after washing is heated as it is. Thus, after the remaining or attached cleaning solvent is removed by drying, the supporting base material may be removed.
The method for producing a substantially non-porous polymer electrolyte membrane by the solution casting method has been described above. As described above, this polymer electrolyte membrane includes other than the above sulfur-containing aromatic compound and polymer electrolyte. (Hereinafter, may be referred to as “other components”). Examples of other components include additives such as plasticizers, stabilizers, mold release agents, and water retention agents that are used in ordinary polymers. These other components may be added to the polymer electrolyte solution when the polymer electrolyte solution to be used is prepared when the solution casting method is used.
<Fuel cell>
Next, the fuel cell having the polymer electrolyte membrane of the present invention will be described. The fuel cell of the present invention can be produced by bonding a catalyst and a conductive material as a current collector to both surfaces of the polymer electrolyte membrane of the present invention.
Here, the catalyst is not particularly limited as long as it can activate the oxidation-reduction reaction with hydrogen or oxygen, and a known catalyst can be used. However, platinum or platinum alloy fine particles can be used as the catalyst. preferable. The fine particles of platinum or platinum-based alloys are often used by being supported on particulate or fibrous carbon such as activated carbon or graphite.
In addition, a paste (catalyst ink) prepared by mixing platinum or a platinum-based alloy supported on carbon with a solvent of a perfluoroalkyl sulfonic acid resin is applied to the gas diffusion layer and dried, whereby A laminated and integrated catalyst layer is obtained. When the obtained catalyst layer is bonded to the polymer electrolyte membrane, a membrane-electrode assembly for a fuel cell can be obtained. As a specific method, for example, J. Org. Electrochem. Soc. : Known methods such as those described in Electrochemical Science and Technology, 1988, 135 (9), 2209 can be used. Also, a membrane-electrode assembly for a fuel cell can be obtained by applying a catalyst ink to a polymer electrolyte membrane and drying it to form a catalyst layer directly on the surface of the membrane.
Here, as the polymer electrolyte used in the catalyst layer, the polymer electrolyte and / or polymer electrolyte composition of the present invention can be used instead of the perfluoroalkyl sulfonic acid resin to form a catalyst composition. . A catalyst layer obtained using this catalyst composition is suitable as a catalyst layer because it can exhibit good long-term stability as in the case of the polymer electrolyte membrane.
A known material can be used for the conductive material as the current collector, but porous carbon woven fabric, carbon non-woven fabric, or carbon paper is preferable in order to efficiently transport the raw material gas to the catalyst.
The fuel cell of the present invention thus produced can be used in various forms using hydrogen gas, reformed hydrogen gas, and methanol as fuel.
In the membrane-electrode assembly and fuel cell using the polymer electrolyte membrane of the present invention, the sulfur-containing aromatic compound introduced into the polymer electrolyte membrane may migrate to the catalyst layer. Such a transition may occur during a process of joining a catalyst and a conductive material as a current collector to both surfaces of the polymer electrolyte membrane and / or during operation of the fuel cell. Here, the operation means any one of aging, starting, operating and stopping of the fuel cell. Such a form is also preferable because it can exhibit good long-term stability, like the polymer electrolyte membrane and the catalyst layer.
　以下に本発明を実施例により説明する。
実施例１
＜チアントレンを含む膜の製造＞
　高分子電解質としては、特開２００９−２７５２１９号公報記載の方法を参考にして、
下記式
Figure JPOXMLDOC01-appb-I000039
で示される繰り返し単位からなる、スルホン酸基を有するセグメント（イオン交換基を有するセグメント）と、
下記式
Figure JPOXMLDOC01-appb-I000040
で示される、イオン性基を実質的に有しないセグメントとを有するブロック共重合体Ａ（イオン交換容量＝２．５ｍｅｑ／ｇ、数平均分子量１．５２×１０５、重量平均分子量３．１９×１０５）を準備した。このときの分子量の測定条件を以下に示す。
分子量の測定：
　ゲルパーミエーションクロマトグラフィー（ＧＰＣ）により、下記条件でポリスチレン換算の数平均分子量、重量平均分子量を測定した。なお、ＧＰＣの分析条件としては、下記の条件を用いた。
・カラム：東ソー社製　ＴＳＫｇｅｌ　ＧＭＨＨＲ−Ｍ
・カラム温度：４０℃
・移動相溶媒：Ｎ，Ｎ−ジメチルホルムアミド（ＬｉＢｒを１０ｍｍｏｌ／ｄｍ３になるように添加）
・溶媒流量：０．５ｍＬ／分
・検出：示差屈折率
　このブロック共重合体Ａをジメチルスルホキシドに約１０重量％の濃度になるように溶解させ、併せてここにチアントレン（ブロック共重合体Ａ／チアントレンの重量比＝９５重量％／５重量％）を溶解させることで高分子電解質溶液を調製した。次いで、この高分子電解質溶液をＰＥＴ基材上に均一に塗り広げ、その後高分子電解質溶液を９０℃で常圧乾燥した。得られる乾燥塗膜を２Ｎ硫酸に浸漬、洗浄した後、イオン交換水で洗浄し、更に常温乾燥し、ＰＥＴ基材から剥離することで高分子電解質膜Ａを得た。
実施例２＜チアントレンを含む膜の燃料電池評価＞
（触媒インクの製造）
　市販の５重量％ナフィオン溶液（溶媒：水と低級アルコールの混合物）７ｍＬに、白金が担持された白金担持カーボン（ＳＡ５０ＢＫ、エヌ・イー・ケムキャット製、白金含有量；５０重量％）を１．００ｇ投入し、さらにエタノールを５５ｇ、水を６．４ｇ加える。得られた混合物を１時間超音波処理した後、スターラーで５時間攪拌して触媒インクを得た。
（膜−電極接合体の製造）
　次に、高分子電解質膜Ａの片面の中央部における３ｃｍ角の領域に、スプレー法により上記の触媒インクを塗布した。この際、吐出口から膜までの距離は６ｃｍとし、ステージ温度は７５℃に設定した。同様の方法で重ね塗りを行った後、塗布物をステージ上に１５分間放置し、これにより溶媒を除去してアノード触媒層を形成させた。得られたアノード触媒層は、その組成と塗布重量から算出して０．６ｍｇ／ｃｍ２の白金を含有するものであった。続いて、高分子電解質膜のアノード触媒層と反対側の面にも同様に触媒インクを塗布して、０．６ｍｇ／ｃｍ２の白金を含むカソード触媒層を形成した。これにより、膜−電極接合体を得た。
（燃料電池セルの製造）
　上記の膜−電極接合体の両外側に、ガス拡散層としてカーボンクロスと、ガス通路用の溝を切削加工したカーボン製セパレータとをこの順で配置し、さらにその外側に集電体及びエンドプレートを順に配置し、これらをボルトで締め付けることによって、有効電極面積９ｃｍ２の燃料電池セルを製造した。
（燃料電池セルの特性評価［負荷変動試験］）
　得られた燃料電池セルを９５℃に保ちながら、低加湿状態の水素（２５ｍＬ／分、背圧０．１ＭＰａＧ）と低加湿状態の空気（６３ｍＬ／分、背圧０．０５ＭＰａＧ）をセルに導入し、開回路と一定電流での負荷変動試験を行うことで、高分子電解質膜や燃料電池セルの長期安定性を評価した。この条件で燃料電池セルを約２００時間作動させた後、膜−電極接合体を取り出してエタノール／水の混合溶液に投入し、さらに超音波処理することで触媒層を取り除いた。そして、残った高分子電解質膜Ａのイオン交換基を有するセグメントの分子量を次の手順で測定した。すなわち、膜中のポリアリーレン系ブロック共重合体４ｍｇに対し、ジメチルスルホキシド８ｍｌを添加し溶解させた後、テトラメチルアンモニウム水酸化物の２５％メタノール溶液１０μＬを１００℃で２時間反応させ、放冷後、得られた溶液の分子量をゲル浸透クロマトグラフィー（ＧＰＣ）により測定した。負荷変動試験前と試験後のイオン交換基を有するセグメントの重量平均分子量、及び、負荷変動試験前後におけるイオン交換基を有するセグメントの重量平均分子量の維持率を表３に示す。この維持率が高いほど、高分子電解質膜の劣化が小さいことを意味する。なお、ＧＰＣの測定条件は下記の通りとした。
・カラム：東ソー社製　ＴＳＫｇｅｌ　ＧＭＨＨＲ−Ｍ
・カラム温度：４０℃
・移動相溶媒：Ｎ，Ｎ−ジメチルホルムアミド（ＬｉＢｒを１０ｍｍｏｌ／ｄｍ３になるように添加）
溶媒流量：０．５ｍＬ／分
・検出：示差屈折率
比較例１＜高分子電解質膜Ｂの燃料電池評価＞
　実施例１において、チアントレンを加えない以外は全て同様にすることで、高分子電解質膜Ｂを得た。また、高分子電解質膜Ｂを実施例２と同様の方法で負荷変動試験を実施し、同様にＧＰＣ分析を行った。負荷変動試験前と試験後のイオン交換基を有するセグメントの重量平均分子量、及び、負荷変動試験前後におけるイオン交換基を有するセグメントの重量平均分子量の維持率を表３に示す。
Figure JPOXMLDOC01-appb-T000041
 　表３より、本発明の含硫黄芳香族化合物を添加して調製された高分子電解質膜は、添加しないものと比較して、負荷変動試験前後でもイオン交換基を有するセグメントの分子量が十分維持されており、優れた長期安定性を有することが判明した。
実施例３＜フェノキサチインを含む膜の製造＞
高分子電解質としては、下記式
Figure JPOXMLDOC01-appb-I000042
で示される繰り返し単位からなる、スルホン酸基を有するセグメント（イオン交換基を有するセグメント）と、下記式
Figure JPOXMLDOC01-appb-I000043
で示される、イオン交換基を実質的に有しないセグメントとを有するブロック共重合体Ｂ（数平均分子量２．８３×１０５、重量平均分子量６．９０×１０５、分子量の測定条件は実施例１と同様である）を、下記に記す［ブロック共重合体Ｂの合成］の方法を参考にして準備した。
［ブロック共重合体Ｂの合成］
　共沸蒸留装置を備えたフラスコに、窒素雰囲気下、４，４’−ジヒドロキシ−１，１’−ビフェニル１０．２ｇ（５４．７ｍｍｏｌ）、炭酸カリウム８．３２ｇ（６０．２ｍｍｏｌ）、Ｎ，Ｎ−ジメチルアセトアミド９６ｇ、トルエン５０ｇを加えた。バス温１５５℃で２．５時間トルエンを加熱還流することで系内の水分を共沸脱水した。生成した水とトルエンを留去した後、室温まで放冷し、４，４’−ジクロロジフェニルスルホン２２．０ｇ（７６．６ｍｍｏｌ）を加えた。バス温を１６０℃に昇温し、１４時間保温撹拌した。放冷後、反応液を、メタノール１０００ｇと３５重量％塩酸２００ｇとの混合溶液に加え、析出した沈殿を濾過した後、イオン交換水で中性になるまで洗浄し、乾燥した。得られた粗生成物２７．２ｇをＮ，Ｎ−ジメチルアセトアミド９７ｇに溶解し、不溶物を濾過した後、メタノール１１００ｇと３５重量％塩酸１００ｇとの混合溶液に加え、析出した沈殿を濾過した後、イオン交換水で中性になるまで洗浄し、乾燥し下記式（Ｅ）で表されるイオン交換基を実質的に有しないセグメントを誘導する前駆体２５．９ｇを得た。
ＧＰＣ分子量：　Ｍｎ＝１７００、Ｍｗ＝３２００
Figure JPOXMLDOC01-appb-I000044
　次に、アルゴン雰囲気下、フラスコに無水臭化ニッケル２．１２ｇ（９．７１ｍｍｏｌ）、Ｎ−メチルピロリドン９６ｇを加え、バス温７０℃で攪拌した。無水臭化ニッケルが溶解したのを確認した後、バス温を５０℃に冷却し、２，２’−ビピリジル１．８２ｇ（１１．７ｍｍｏｌ）を加え、ニッケル含有溶液を調製した。
　アルゴン雰囲気下、フラスコに上記式（Ｅ）で表されるイオン交換基を実質的に有しないセグメントを誘導する前駆体４．０２ｇ、Ｎ−メチルピロリドン３８４ｇを加え５０℃に調整した。得られた溶液に、亜鉛粉末３．８１ｇ（５８．２ｍｍｏｌ）、メタンスルホン酸１重量部とＮ−メチルピロリドン９重量部との混合溶液１．０５ｇ、及び、４，４’−ジクロロビフェニル−２，２’−ジスルホン酸ジ（２，２−ジメチルプロピル）２４．０ｇ（４５．９ｍｍｏｌ）を加え、５０℃で３０分間撹拌した。これに、前記ニッケル含有溶液を注ぎ込み、５０℃で６時間重合反応を行い、黒色の重合溶液を得た。
　得られた重合溶液を、１３重量％塩酸３３６０ｇに投入し、室温で３０分間撹拌した。生じた沈殿を濾過した後、１３重量％塩酸３３６０ｇを加え、室温で３０分間撹拌し、濾過し、イオン交換水で濾液のｐＨが４を越えるまで洗浄した。得られた粗ポリマーに、イオン交換水８４０ｇと、メタノール７９０ｇを加え、バス温９０℃で１時間加熱撹拌した。粗ポリマーをろ過し、乾燥することで、スルホン酸前駆基（スルホン酸（２，２−ジメチルプロピル）基）を有するポリマー（Ｆ）２３．９ｇを得た。
　次に、以下のようにしてスルホン酸前駆基をスルホ基に変換した。上述のようにして得られたスルホン酸前駆基を有するポリマー（Ｆ）２３．９ｇ、イオン交換水４７．８ｇ、無水臭化リチウム１５．９ｇ（１８３ｍｍｏｌ）及びＮ−メチルピロリドン４７８ｇをフラスコに入れ、バス温１２６℃で１２時間加熱撹拌し、ポリマー溶液を得た。得られたポリマー溶液を１３重量％塩酸３３４０ｇに投入し、１時間攪拌した。析出した粗ポリマーを濾過し、メタノール１０重量部と３５％塩酸１０重量部との混合溶液２３９０ｇで洗浄する操作を３回繰り返した。その後、濾液のｐＨが４を越えるまでイオン交換水で洗浄した。続いて、得られたポリマーに大量のイオン交換水を加え、９０℃以上に昇温し、約１０分間加熱保温し濾過する洗浄操作を、５回繰り返した。得られたポリマーを乾燥することにより下記式
Figure JPOXMLDOC01-appb-I000045
で示される繰り返し単位からなる、スルホン酸基を有するセグメント（イオン交換基を有するセグメント）と、
下記式
Figure JPOXMLDOC01-appb-I000046
で示されるイオン交換基を実質的に有しないセグメントとを含むブロック共重合体Ｂ１７．３ｇを得た。
重量平均分子量：６．８０×１０５
イオン交換容量（ｍｅｑ／ｇ）：４．６
（分子量の測定条件は実施例１と同様である）
　ブロック共重合体Ｂをジメチルスルホキシドに約５．８重量％の濃度になるように溶解させ、併せてここにフェノキサチイン（ブロック共重合体Ｂ／フェノキサチインの重量比＝１００重量％／５重量％）を溶解させることで高分子電解質溶液を調製した。
　次いで、この高分子電解質溶液をＰＥＴ基材上に均一に塗り広げ、その後高分子電解質溶液を１００℃で常圧乾燥する。得られる乾燥塗膜を２Ｎ硫酸に浸漬、洗浄した後、イオン交換水で洗浄し、更に常温乾燥し、ＰＥＴ基材から剥離することで高分子電解質膜Ｃを得た。該高分子電解質膜Ｃを用いた燃料電池は、長期安定性に優れる。
実施例４＜チオキサントンを含む膜の製造＞
　実施例３において、フェノキサチインの代わりにチオキサントンを用いることで、高分子電解質膜Ｄを得た。該高分子電解質膜Ｄを用いた燃料電池は、長期安定性に優れる。
実施例５＜ジベンゾチオフェンを含む膜の製造＞
　実施例３において、フェノキサチインの代わりにジベンゾチオフェンを用いることで、高分子電解質膜Ｅを得た。該高分子電解質膜Ｅを用いた燃料電池は、長期安定性に優れる。
実施例６＜４−ベンゾイル４’−メチルジフェニルスルフィドを含む膜の製造＞
　実施例３において、フェノキサチインの代わりに４−ベンゾイル４’−メチルジフェニルスルフィドを用いることで、高分子電解質膜Ｆを得た。該高分子電解質膜Ｆを用いた燃料電池は、長期安定性に優れる。
実施例７＜チアントレンを含む膜の製造＞
　高分子電解質としては、特開２００５−１９７２３６号公報記載の方法を参考にして、高分子電解質としては、下記式
Figure JPOXMLDOC01-appb-I000047
で示される繰り返し単位からなる、スルホン酸基を有するセグメント（イオン交換基を有するセグメント）と、下記式
Figure JPOXMLDOC01-appb-I000048
で示される、イオン交換基を実質的に有しない構造単位を有するブロック共重合体Ｃ（イオン交換容量＝２．００ｍｅｑ／ｇ、数平均分子量＝１０２０００、重量平均分子量＝２５３０００、なお、数平均分子量および重量平均分子量は実施例１のＧＰＣ条件での分析により得た）を準備した。
　このブロック共重合体ＣをＮ−メチルピロリドン／メタノール＝６０重量％／４０重量％の溶液に約２０重量％の濃度になるように溶解させ、併せてここにチアントレン（ブロック共重合体Ｃ／チアントレンの重量比＝１００重量％／５重量％）を溶解させることで高分子電解質溶液を調製した。次いで、この高分子電解質溶液をＰＥＴ基材上に均一に塗り広げ、その後高分子電解質溶液を８０℃で４０分予備乾燥した後、１２０℃で４０分乾燥した。得られる乾燥塗膜を大量の蒸留水に一晩浸漬した後、風乾し、ＰＥＴ基材から剥離することで高分子電解質膜Ｇを得た。
実施例８＜チアントレンを含む膜の燃料電池評価＞
　上記の高分子電解質膜Ａの代わりに高分子電解質膜Ｇを用いて上記実施例２と同様な手法により、膜−電極接合体および該膜−電極接合体を有する燃料電池セルを製造した。
（燃料電池セルの特性評価［開回路試験］）
　高分子電解質膜Ｇを使用して製造した燃料電池セルについて特性評価を行なった。すなわち、作製した燃料電池セルを９５℃に保ちながら、アノード触媒層側には低加湿状態の水素（２５ｍＬ／分、背圧０．１ＭＰａＧ）を供給し、カソード触媒層側には低加湿状態の空気（６３ｍＬ／分、背圧０．０５ＭＰａＧ）を供給して、開回路試験を行った。各原料ガスの加湿は水の入ったバブラーにガスを通すことで行い、水素バブラーの水温は９５℃、空気用バブラーの水温は３０℃とした。
　この条件で燃料電池セルを１００時間継続して作動させた。
　該試験後、実施例２と同様に高分子電解質膜を取出しＧＰＣ分析を行った。該試験前後におけるイオン交換基を有するセグメントの重量平均分子量の維持率を表４に示す。
比較例２＜ブロック共重合体Ｃ膜の燃料電池評価＞
　実施例７において、チアントレンを加えない以外は全て同様にすることで、高分子電解質膜Ｈを得た。また、高分子電解質膜Ｈを実施例８と同様の方法で発電特性試験を実施し、評価した。該試験前後におけるイオン交換基を有するセグメントの重量平均分子量の維持率を表４に示す。
Figure JPOXMLDOC01-appb-T000049
 　表４より、本発明の含硫黄芳香族化合物を添加して調製された高分子電解質膜は、添加しないものと比較して、開回路試験前後でも高分子電解質の分子量が高く維持されており、優れた長期安定性を有することが判明した。
実施例９＜チアントレンを含む膜の製造＞
　チアントレン（０．０５ｇ）をテトラヒドロフラン２０ｇに溶解し、市販の２０質量％ナフィオン（登録商標）溶液（アルドリッチ社製、溶媒：水と低級アルコールの混合物）２．８８ｇ、エタノール３．２ｇを加え、室温にて６時間攪拌することで、劣化防止剤溶液を得た。
　得られた劣化防止剤溶液をナフィオンＸＬ（登録商標）膜の片面の中央部における３ｃｍ×３ｃｍの領域に、スプレー法にて塗布した。この際、吐出口から膜までの距離は６ｃｍ、ステージ温度は６０℃に設定した。さらに重ね塗りを行い溶媒を除去することで劣化防止剤層を形成し、３ｃｍ×３ｃｍの領域に固形分が５．４７ｍｇ配置された高分子電解質膜００１を得た。
実施例１０＜チアントレンを含む膜の燃料電池評価＞
［触媒インクの作成］
　市販の５質量％ナフィオン（登録商標）溶液（アルドリッチ社製、溶媒：水と低級アルコールの混合物）６．３０ｇに、白金が担持された白金担持カーボン（ＳＡ５０ＢＫ、エヌ・イー・ケムキャット製、白金含有量；５０質量％）１．００ｇ投入し、さらにエタノール４３．４５ｇ、水６．４３ｇを加えた。得られた混合物を１時間超音波処理した後、スターラーで５時間攪拌して触媒インクを得た。
［膜電極接合体の作製］
　一方の表面に劣化防止剤層を形成した高分子電解質膜００１について、劣化防止剤層を有さない表面の中央部における３ｃｍ×３ｃｍの領域に、スプレー法にて上記の触媒インクを塗布した。この際、吐出口から膜までの距離は６ｃｍ、ステージ温度は７５℃に設定した。同様にして重ね塗りをした後、溶媒を除去してアノード触媒層を形成させた。アノード触媒層として１４．２ｍｇの固形分（白金目付け：０．６ｍｇ／ｃｍ２）が塗布された。
　続いて、劣化防止剤層の上に同様に触媒インクを塗布して、カソード触媒層を形成させ膜電極接合体を得た。カソード触媒層として１４．２ｍｇの固形分（白金目付け：０．６ｍｇ／ｃｍ２）が塗布された。
［燃料電池セルの組み立て］
　上述のようにして得られたＭＥＡの両外側に、ガス拡散層としてカーボンクロスと、ガス通路用の溝を切削加工したカーボン製セパレータとを配し、さらにその外側に集電体及びエンドプレートを順に配置し、これらをボルトで締め付けることによって、有効電極面積９ｃｍ２の燃料電池セルを組み立てた。
［燃料電池セルの耐久性評価］
　実施例８と同様の方法にて、上記開回路試験を１００時間実施した。
上記開回路試験において発生した排水を、セル中のガス排出口から空気極側と燃料極側から共に採取し、これをイオンクロマトグラフィーにかけ、フッ化物イオンおよび硫酸イオンの溶出速度を算出した。イオンクロマトグラフィーの測定条件を以下に示す。結果を表５に示す。
機器：Ｄｉｏｎｅｘ社製　ＤＸ−５００
カラム：Ｄｉｏｎｅｘ社製　ＩｏｎＰａｃ　ＡＳ−１７Ｃ
溶離液：１０ｍＭの水酸化カリウム（ＫＯＨ）水溶液
溶離液の流速：１．０ｍｌ／ｍｉｎ
（比較例３）
　高分子電解質膜００１の代わりにナフィオンＸＬ（登録商標）膜を用いたこと以外は、実施例１０と同様の方法にて膜電極接合体および、燃料電池セルを作製し、同様に上記開回路試験を１００時間実施し、評価した。結果を表５に示す。
Figure JPOXMLDOC01-appb-T000050
 　表５より、実施例１０は排水中のフッ化物イオンおよび硫酸イオンの溶出速度が比較例３より小さいものであり、高分子電解質の劣化を抑制していることがわかる。これより、本発明の含硫黄芳香族化合物はフッ素系高分子電解質に対しても安定化剤として大変有用であることが判明した。 Hereinafter, the present invention will be described by way of examples.
Example 1
<Manufacture of membrane containing thianthrene>
As the polymer electrolyte, referring to the method described in JP-A-2009-275219,
Following formula
Figure JPOXMLDOC01-appb-I000039
A segment having a sulfonic acid group (segment having an ion-exchange group) consisting of a repeating unit represented by:
Following formula
Figure JPOXMLDOC01-appb-I000040
And a block copolymer A having a segment substantially free of ionic groups (ion exchange capacity = 2.5 meq / g, number average molecular weight 1.52 × 10 5 , weight average molecular weight 3.19 × 10 5 ) was prepared. The measurement conditions of the molecular weight at this time are shown below.
Molecular weight measurement:
The number average molecular weight and weight average molecular weight in terms of polystyrene were measured by gel permeation chromatography (GPC) under the following conditions. The following conditions were used as GPC analysis conditions.
・ Column: TSKgel GMH HR- M manufactured by Tosoh Corporation
-Column temperature: 40 ° C
Mobile phase solvent: N, N-dimethylformamide (LiBr added to 10 mmol / dm3)
Solvent flow rate: 0.5 mL / min Detection: differential refractive index This block copolymer A is dissolved in dimethyl sulfoxide to a concentration of about 10% by weight, and combined with thianthrene (block copolymer A / A polymer electrolyte solution was prepared by dissolving a thianthrene weight ratio = 95 wt% / 5 wt%. Next, this polymer electrolyte solution was uniformly spread on a PET substrate, and then the polymer electrolyte solution was dried at 90 ° C. under normal pressure. The obtained dried coating film was immersed and washed in 2N sulfuric acid, then washed with ion-exchanged water, further dried at room temperature, and peeled from the PET substrate to obtain a polymer electrolyte membrane A.
Example 2 <Fuel Cell Evaluation of Membrane Containing Thianthrene>
(Manufacture of catalyst ink)
1.00 g of platinum-supported carbon (SA50BK, manufactured by N.E. Chemcat, platinum content; 50% by weight) in which platinum is supported on 7 mL of a commercially available 5% by weight Nafion solution (solvent: mixture of water and lower alcohol) Add 55 g of ethanol and 6.4 g of water. The obtained mixture was subjected to ultrasonic treatment for 1 hour and then stirred with a stirrer for 5 hours to obtain a catalyst ink.
(Manufacture of membrane-electrode assembly)
Next, the catalyst ink was applied to a 3 cm square region at the center of one side of the polymer electrolyte membrane A by a spray method. At this time, the distance from the discharge port to the film was 6 cm, and the stage temperature was set to 75 ° C. After overcoating in the same manner, the coated material was allowed to stand on the stage for 15 minutes, thereby removing the solvent and forming an anode catalyst layer. The obtained anode catalyst layer contained 0.6 mg / cm 2 of platinum calculated from the composition and coating weight. Subsequently, catalyst ink was similarly applied to the surface of the polymer electrolyte membrane opposite to the anode catalyst layer to form a cathode catalyst layer containing 0.6 mg / cm 2 of platinum. As a result, a membrane-electrode assembly was obtained.
(Manufacture of fuel cells)
On both outer sides of the membrane-electrode assembly, a carbon cloth as a gas diffusion layer and a carbon separator in which a gas passage groove is cut are disposed in this order, and a current collector and an end plate are further disposed on the outer side. Were arranged in order, and these were tightened with bolts to produce a fuel cell having an effective electrode area of 9 cm 2 .
(Characteristic evaluation of fuel cell [Load fluctuation test])
While maintaining the obtained fuel cell at 95 ° C., low humidified hydrogen (25 mL / min, back pressure 0.1 MPaG) and low humidified air (63 mL / min, back pressure 0.05 MPaG) were introduced into the cell. The long-term stability of polymer electrolyte membranes and fuel cells was evaluated by performing load fluctuation tests with an open circuit and a constant current. After operating the fuel cell under these conditions for about 200 hours, the membrane-electrode assembly was taken out, put into a mixed solution of ethanol / water, and further subjected to ultrasonic treatment to remove the catalyst layer. And the molecular weight of the segment which has the ion exchange group of the remaining polymer electrolyte membrane A was measured in the following procedure. That is, after adding 8 ml of dimethyl sulfoxide to 4 mg of the polyarylene block copolymer in the film and dissolving it, 10 μL of a 25% methanol solution of tetramethylammonium hydroxide was reacted at 100 ° C. for 2 hours and allowed to cool. Thereafter, the molecular weight of the obtained solution was measured by gel permeation chromatography (GPC). Table 3 shows the weight average molecular weight of the segment having an ion exchange group before and after the load fluctuation test and the maintenance ratio of the weight average molecular weight of the segment having an ion exchange group before and after the load fluctuation test. The higher the maintenance rate, the smaller the deterioration of the polymer electrolyte membrane. The GPC measurement conditions were as follows.
・ Column: TSKgel GMH HR- M manufactured by Tosoh Corporation
-Column temperature: 40 ° C
Mobile phase solvent: N, N-dimethylformamide (LiBr added to 10 mmol / dm3)
Solvent flow rate: 0.5 mL / min. Detection: Differential refractive index comparative example 1 <Fuel cell evaluation of polymer electrolyte membrane B>
In Example 1, a polymer electrolyte membrane B was obtained in the same manner except that thianthrene was not added. Further, a load fluctuation test was performed on the polymer electrolyte membrane B in the same manner as in Example 2, and GPC analysis was performed in the same manner. Table 3 shows the weight average molecular weight of the segment having an ion exchange group before and after the load fluctuation test and the maintenance ratio of the weight average molecular weight of the segment having an ion exchange group before and after the load fluctuation test.
Figure JPOXMLDOC01-appb-T000041
 From Table 3, the polymer electrolyte membrane prepared by adding the sulfur-containing aromatic compound of the present invention sufficiently maintains the molecular weight of the segment having an ion-exchange group even before and after the load fluctuation test, compared to the polymer electrolyte membrane not added. And has been found to have excellent long-term stability.
Example 3 <Production of membrane containing phenoxathiin>
As the polymer electrolyte, the following formula
Figure JPOXMLDOC01-appb-I000042
A segment having a sulfonic acid group (segment having an ion-exchange group) and a repeating unit represented by the following formula:
Figure JPOXMLDOC01-appb-I000043
And a block copolymer B having a segment substantially free of ion-exchange groups (number average molecular weight 2.83 × 10 5 , weight average molecular weight 6.90 × 10 5 , molecular weight measurement conditions are the same as in Examples) 1 was prepared with reference to the method of [Synthesis of block copolymer B] described below.
[Synthesis of Block Copolymer B]
In a flask equipped with an azeotropic distillation apparatus, under a nitrogen atmosphere, 10.4 g (54.7 mmol) of 4,4′-dihydroxy-1,1′-biphenyl, 8.32 g (60.2 mmol) of potassium carbonate, N, N -96 g of dimethylacetamide and 50 g of toluene were added. Water in the system was azeotropically dehydrated by heating and refluxing toluene at a bath temperature of 155 ° C. for 2.5 hours. After the produced water and toluene were distilled off, the mixture was allowed to cool to room temperature, and 22.0 g (76.6 mmol) of 4,4′-dichlorodiphenylsulfone was added. The bath temperature was raised to 160 ° C., and the mixture was stirred while keeping for 14 hours. After allowing to cool, the reaction solution was added to a mixed solution of 1000 g of methanol and 200 g of 35 wt% hydrochloric acid, and the deposited precipitate was filtered, washed with ion-exchanged water until neutral, and dried. 27.2 g of the obtained crude product was dissolved in 97 g of N, N-dimethylacetamide, insoluble matter was filtered, added to a mixed solution of 1100 g of methanol and 100 g of 35 wt% hydrochloric acid, and the deposited precipitate was filtered. Then, it was washed with ion-exchanged water until neutral, and dried to obtain 25.9 g of a precursor that induces a segment substantially not having an ion-exchange group represented by the following formula (E).
GPC molecular weight: Mn = 1700, Mw = 3200
Figure JPOXMLDOC01-appb-I000044
Next, 2.12 g (9.71 mmol) of anhydrous nickel bromide and 96 g of N-methylpyrrolidone were added to the flask under an argon atmosphere, and the mixture was stirred at a bath temperature of 70 ° C. After confirming that the anhydrous nickel bromide was dissolved, the bath temperature was cooled to 50 ° C., and 1.82 g (11.7 mmol) of 2,2′-bipyridyl was added to prepare a nickel-containing solution.
Under an argon atmosphere, 4.02 g of a precursor that induces a segment substantially not having the ion exchange group represented by the above formula (E) and 384 g of N-methylpyrrolidone were added to the flask, and the temperature was adjusted to 50 ° C. To the resulting solution, 3.81 g (58.2 mmol) of zinc powder, 1.05 g of a mixed solution of 1 part by weight of methanesulfonic acid and 9 parts by weight of N-methylpyrrolidone, and 4,4′-dichlorobiphenyl-2 , 2′-Disulfonic acid di (2,2-dimethylpropyl) 24.0 g (45.9 mmol) was added, and the mixture was stirred at 50 ° C. for 30 minutes. The nickel-containing solution was poured into this, and a polymerization reaction was performed at 50 ° C. for 6 hours to obtain a black polymerization solution.
The obtained polymerization solution was put into 3360 g of 13 wt% hydrochloric acid and stirred at room temperature for 30 minutes. After the resulting precipitate was filtered, 3360 g of 13 wt% hydrochloric acid was added, stirred at room temperature for 30 minutes, filtered, and washed with ion exchange water until the pH of the filtrate exceeded 4. To the obtained crude polymer, 840 g of ion exchanged water and 790 g of methanol were added, and the mixture was heated and stirred at a bath temperature of 90 ° C. for 1 hour. The crude polymer was filtered and dried to obtain 23.9 g of a polymer (F) having a sulfonic acid precursor group (sulfonic acid (2,2-dimethylpropyl) group).
Next, the sulfonic acid precursor group was converted to a sulfo group as follows. 23.9 g of the polymer (F) having a sulfonic acid precursor group obtained as described above, 47.8 g of ion-exchanged water, 15.9 g (183 mmol) of anhydrous lithium bromide and 478 g of N-methylpyrrolidone were placed in a flask. The mixture was heated and stirred at a bath temperature of 126 ° C. for 12 hours to obtain a polymer solution. The obtained polymer solution was added to 3340 g of 13 wt% hydrochloric acid and stirred for 1 hour. The operation of filtering the precipitated crude polymer and washing with 2390 g of a mixed solution of 10 parts by weight of methanol and 10 parts by weight of 35% hydrochloric acid was repeated three times. Thereafter, the filtrate was washed with ion-exchanged water until the pH of the filtrate exceeded 4. Subsequently, a large amount of ion-exchanged water was added to the obtained polymer, the temperature was raised to 90 ° C. or higher, and the washing operation in which heat was kept for about 10 minutes and filtration was repeated 5 times. By drying the obtained polymer, the following formula
Figure JPOXMLDOC01-appb-I000045
A segment having a sulfonic acid group (segment having an ion-exchange group) consisting of a repeating unit represented by:
Following formula
Figure JPOXMLDOC01-appb-I000046
In this manner, 17.3 g of a block copolymer B including a segment having substantially no ion exchange group represented by the formula (1) was obtained.
Weight average molecular weight: 6.80 × 10 5
Ion exchange capacity (meq / g): 4.6
(The measurement conditions of the molecular weight are the same as in Example 1)
Block copolymer B was dissolved in dimethyl sulfoxide to a concentration of about 5.8% by weight, and phenoxathiin (weight ratio of block copolymer B / phenoxathiin = 100% by weight / 5) (% By weight) was dissolved to prepare a polymer electrolyte solution.
Next, this polymer electrolyte solution is uniformly spread on a PET substrate, and then the polymer electrolyte solution is dried at 100 ° C. under normal pressure. The obtained dried coating film was immersed and washed in 2N sulfuric acid, then washed with ion-exchanged water, further dried at room temperature, and peeled from the PET substrate to obtain a polymer electrolyte membrane C. A fuel cell using the polymer electrolyte membrane C is excellent in long-term stability.
Example 4 <Production of membrane containing thioxanthone>
In Example 3, a polymer electrolyte membrane D was obtained by using thioxanthone instead of phenoxathiin. A fuel cell using the polymer electrolyte membrane D is excellent in long-term stability.
Example 5 <Production of membrane containing dibenzothiophene>
In Example 3, a polymer electrolyte membrane E was obtained by using dibenzothiophene instead of phenoxathiin. A fuel cell using the polymer electrolyte membrane E is excellent in long-term stability.
Example 6 <Production of membrane containing 4-benzoyl 4'-methyldiphenyl sulfide>
In Example 3, a polymer electrolyte membrane F was obtained by using 4-benzoyl 4′-methyldiphenyl sulfide instead of phenoxathiin. A fuel cell using the polymer electrolyte membrane F is excellent in long-term stability.
Example 7 <Production of membrane containing thianthrene>
As the polymer electrolyte, referring to the method described in JP-A-2005-197236, as the polymer electrolyte, the following formula
Figure JPOXMLDOC01-appb-I000047
A segment having a sulfonic acid group (segment having an ion-exchange group) and a repeating unit represented by the following formula:
Figure JPOXMLDOC01-appb-I000048
The block copolymer C having a structural unit substantially having no ion exchange group (ion exchange capacity = 2.00 meq / g, number average molecular weight = 102000, weight average molecular weight = 253000, number average molecular weight The weight average molecular weight was obtained by analysis under the GPC conditions of Example 1).
This block copolymer C was dissolved in a solution of N-methylpyrrolidone / methanol = 60% by weight / 40% by weight to a concentration of about 20% by weight, and this was combined with thianthrene (block copolymer C / thianthrene). (Weight ratio = 100 wt% / 5 wt%) was dissolved to prepare a polymer electrolyte solution. Next, this polymer electrolyte solution was uniformly spread on a PET substrate, and then the polymer electrolyte solution was pre-dried at 80 ° C. for 40 minutes and then dried at 120 ° C. for 40 minutes. The resulting dried coating film was immersed in a large amount of distilled water overnight, then air-dried and peeled from the PET substrate to obtain a polymer electrolyte membrane G.
Example 8 <Fuel Cell Evaluation of Membrane Containing Thianthrene>
Using the polymer electrolyte membrane G instead of the polymer electrolyte membrane A, a membrane-electrode assembly and a fuel cell having the membrane-electrode assembly were produced in the same manner as in Example 2.
(Characteristic evaluation of fuel cell [open circuit test])
The characteristics of fuel cells manufactured using the polymer electrolyte membrane G were evaluated. That is, while maintaining the prepared fuel cell at 95 ° C., low humidified hydrogen (25 mL / min, back pressure 0.1 MPaG) is supplied to the anode catalyst layer side, and low humidified state is supplied to the cathode catalyst layer side. An open circuit test was performed by supplying air (63 mL / min, back pressure 0.05 MPaG). Each source gas was humidified by passing the gas through a bubbler containing water. The water temperature of the hydrogen bubbler was 95 ° C., and the water temperature of the air bubbler was 30 ° C.
Under these conditions, the fuel cell was continuously operated for 100 hours.
After the test, the polymer electrolyte membrane was taken out and subjected to GPC analysis in the same manner as in Example 2. Table 4 shows the maintenance ratio of the weight average molecular weight of the segments having ion exchange groups before and after the test.
Comparative Example 2 <Fuel Cell Evaluation of Block Copolymer C Membrane>
In Example 7, a polymer electrolyte membrane H was obtained in the same manner except that thianthrene was not added. Further, the polymer electrolyte membrane H was evaluated by conducting a power generation characteristic test in the same manner as in Example 8. Table 4 shows the maintenance ratio of the weight average molecular weight of the segments having ion exchange groups before and after the test.
Figure JPOXMLDOC01-appb-T000049
 From Table 4, the polymer electrolyte membrane prepared by adding the sulfur-containing aromatic compound of the present invention, the molecular weight of the polymer electrolyte is maintained high before and after the open circuit test, compared with the one not added, It has been found to have excellent long-term stability.
Example 9 <Production of membrane containing thianthrene>
Thianthrene (0.05 g) was dissolved in 20 g of tetrahydrofuran, 2.88 g of a commercially available 20% by mass Nafion (registered trademark) solution (manufactured by Aldrich, solvent: mixture of water and lower alcohol), and 3.2 g of ethanol were added. For 6 hours to obtain a deterioration inhibitor solution.
The obtained deterioration inhibitor solution was applied to a 3 cm × 3 cm region at the center of one side of the Nafion XL (registered trademark) film by a spray method. At this time, the distance from the discharge port to the film was set to 6 cm, and the stage temperature was set to 60 ° C. Further, the deterioration preventing agent layer was formed by recoating and removing the solvent to obtain a polymer electrolyte membrane 001 having a solid content of 5.47 mg disposed in a 3 cm × 3 cm region.
Example 10 <Fuel Cell Evaluation of Membrane Containing Thianthrene>
[Catalyst ink creation]
Platinum-supported carbon (SA50BK, N.E. Chemcat, platinum-containing) in which platinum is supported on 6.30 g of a commercially available 5% by mass Nafion (registered trademark) solution (manufactured by Aldrich, solvent: mixture of water and lower alcohol) (Amount: 50% by mass) 1.00 g was added, and 43.45 g of ethanol and 6.43 g of water were further added. The obtained mixture was subjected to ultrasonic treatment for 1 hour and then stirred with a stirrer for 5 hours to obtain a catalyst ink.
[Production of membrane electrode assembly]
With respect to the polymer electrolyte membrane 001 having a deterioration preventing agent layer formed on one surface, the above-described catalyst ink was applied by spraying to a 3 cm × 3 cm region in the center of the surface not having the deterioration preventing agent layer. At this time, the distance from the discharge port to the film was set to 6 cm, and the stage temperature was set to 75 ° C. After overcoating in the same manner, the solvent was removed to form an anode catalyst layer. As an anode catalyst layer, 14.2 mg of solid content (platinum weight: 0.6 mg / cm 2 ) was applied.
Subsequently, a catalyst ink was similarly applied on the deterioration preventing agent layer to form a cathode catalyst layer, thereby obtaining a membrane electrode assembly. As the cathode catalyst layer, 14.2 mg of solid content (platinum weight: 0.6 mg / cm 2 ) was applied.
[Assembly of fuel cell]
On both outer sides of the MEA obtained as described above, a carbon cloth as a gas diffusion layer and a carbon separator having a gas passage groove cut are arranged, and a current collector and an end plate are further provided on the outer side. The fuel cells having an effective electrode area of 9 cm 2 were assembled by sequentially arranging them and fastening them with bolts.
[Durability evaluation of fuel cells]
The open circuit test was conducted for 100 hours in the same manner as in Example 8.
The wastewater generated in the open circuit test was collected from the gas discharge port in the cell from the air electrode side and the fuel electrode side, and subjected to ion chromatography to calculate the elution rate of fluoride ions and sulfate ions. The measurement conditions for ion chromatography are shown below. The results are shown in Table 5.
Equipment: DX-500 manufactured by Dionex
Column: IonPac AS-17C manufactured by Dionex
Eluent: 10 mM potassium hydroxide (KOH) aqueous solution Eluent flow rate: 1.0 ml / min
(Comparative Example 3)
A membrane electrode assembly and a fuel cell were prepared in the same manner as in Example 10 except that a Nafion XL (registered trademark) membrane was used instead of the polymer electrolyte membrane 001, and the above open circuit test was conducted in the same manner. Was carried out for 100 hours and evaluated. The results are shown in Table 5.
Figure JPOXMLDOC01-appb-T000050
 From Table 5, it can be seen that in Example 10, the elution rate of fluoride ions and sulfate ions in the wastewater is smaller than that of Comparative Example 3, and the deterioration of the polymer electrolyte is suppressed. From this, it was found that the sulfur-containing aromatic compound of the present invention is very useful as a stabilizer for a fluorine-based polymer electrolyte.
　本発明の電解質組成物を用いることで、ラジカル耐性に優れた高分子電解質膜等の燃料電池用部材を得ることができる。かかる燃料電池用部材を備えた燃料電池は長期安定性に優れるものとなるので、工業的に極めて有用である。 By using the electrolyte composition of the present invention, a fuel cell member such as a polymer electrolyte membrane having excellent radical resistance can be obtained. Since a fuel cell provided with such a fuel cell member has excellent long-term stability, it is extremely useful industrially.

Claims (11)

  1. 　下記含硫黄芳香族化合物［Ａ］~［Ｄ］からなる群より選ばれる一種以上の含硫黄芳香族化合物と高分子電解質とを含有することを特徴とする高分子電解質組成物。
    含硫黄芳香族化合物［Ａ］：下記式（１）で表される含硫黄芳香族化合物。
    Figure JPOXMLDOC01-appb-I000001
    （式（１）中、Ｙ１は硫黄原子を含む２価の基を表す。Ｃ１~Ｃ４はそれぞれ炭素原子を表す。環Ａｒ０１は、Ｃ１およびＣ２を含み、置換基を有していてもよい炭素数４~５０の芳香環を表す。環Ａｒ０２は、Ｃ３およびＣ４を含み、置換基を有していてもよい炭素数４~５０の芳香環を表す。Ａｒ０１が有していてもよい置換基およびＡｒ０２が有していてもよい置換基はそれぞれ、水酸基、ハロゲノ基、シアノ基、カルボキシ基、ホスホノ基、スルホ基、ホルミル基、メルカプト基、メチル基、置換基を有していてもよい炭素数４~２０のアリール基、置換基を有していてもよい炭素数４~２０のアリールオキシ基、置換基を有していてもよい炭素数４~２０のアリールチオ基、置換基を有していてもよい炭素数５~２１のアロイル基および置換基を有していてもよい炭素数４~２０のアリールスルホニル基からなる群より選ばれる１種以上の基である。Ｘ１およびＸ２は、それぞれ同一または相異なり、水素原子、水酸基、ハロゲノ基、シアノ基、カルボキシ基、ホスホノ基、スルホ基、ホルミル基、メルカプト基、メチル基、置換基を有していてもよい炭素数４~２０のアリール基、置換基を有していてもよい炭素数４~２０のアリールオキシ基、置換基を有していてもよい炭素数４~２０のアリールチオ基、置換基を有していてもよい炭素数５~２１のアロイル基または置換基を有していてもよい炭素数４~２０のアリールスルホニル基を表す。）
    含硫黄芳香族化合物［Ｂ］：下記式（２）で表される含硫黄芳香族化合物。
    Figure JPOXMLDOC01-appb-I000002
    （式（２）中、Ｙ１は上記と同義である。Ｚ１は、直接結合、下記式（２−１）~（２−９）のいずれかで示される２価の基を表す。Ｃ５~Ｃ８はそれぞれ炭素原子を表す。環Ａｒ０３は、Ｃ５およびＣ６を含み、置換基を有していてもよい炭素数４~５０の芳香環を表す。環Ａｒ０４は、Ｃ７およびＣ８を含み、置換基を有していてもよい炭素数４~５０の芳香環を表す。
    Figure JPOXMLDOC01-appb-I000003
    （式（２−１）~（２−９）中、Ｅ１は水素原子、水酸基、メチル基、メトキシ基または炭素数４~５０の芳香族基を表す。））
    含硫黄芳香族化合物［Ｃ］：下記式（３）で表される含硫黄芳香族化合物。
    Figure JPOXMLDOC01-appb-I000004
    （式（３）中、Ｙ１およびＺ１はそれぞれ上記と同義である。Ｃ９~Ｃ１２はそれぞれ炭素原子を表す。Ｘ３~Ｘ６は、それぞれ同一または相異なり、水素原子、水酸基、ハロゲノ基、シアノ基、カルボキシ基、ホスホノ基、スルホ基、ホルミル基、メルカプト基、置換基を有していてもよい炭素数１~２０のアルキル基、置換基を有していてもよい炭素数１~２０のアルコキシ基、置換基を有していてもよい炭素数１~２０のアルキルチオ基、置換基を有していてもよい炭素数３~２０のアリール基、置換基を有していてもよい炭素数３~２０のアリールオキシ基、置換基を有していてもよい炭素数３~２０のアリールチオ基、置換基を有していてもよい炭素数２~２１のアシル基、置換基を有していてもよい炭素数４~２１のアロイル基、置換基を有していてもよい炭素数３~２０のアリールスルホニル基または置換基を有していてもよい炭素数１~２０のアルキルスルホニル基を表す。Ｚ１が直接結合の場合、Ｘ４およびＸ５は互いに結合することにより、環を形成していてもよい。）
    含硫黄芳香族化合物［Ｄ］：下記式（４）で表される含硫黄芳香族化合物。
    Figure JPOXMLDOC01-appb-I000005
    （式（４）中、Ｙ１およびＺ１は上記と同義である。Ｃ１３~Ｃ１６はそれぞれ炭素原子を表す。環Ａｒ０５は、Ｃ１５およびＣ１６を含み、置換基を有していてもよい炭素数４~５０の芳香環を表す。Ｘ７およびＸ８は、それぞれ同一または相異なり、水素原子、水酸基、ハロゲノ基、シアノ基、カルボキシ基、ホスホノ基、スルホ基、ホルミル基、メルカプト基、置換基を有していてもよい炭素数１~２０のアルキル基、置換基を有していてもよい炭素数１~２０のアルコキシ基、置換基を有していてもよい炭素数１~２０のアルキルチオ基、置換基を有していてもよい炭素数３~２０のアリール基、置換基を有していてもよい炭素数３~２０のアリールオキシ基、置換基を有していてもよい炭素数３~２０のアリールチオ基、置換基を有していてもよい炭素数２~２１のアシル基、置換基を有していてもよい炭素数４~２１のアロイル基、置換基を有していてもよい炭素数３~２０のアリールスルホニル基または置換基を有していてもよい炭素数１~２０のアルキルスルホニル基を表す。）     A polymer electrolyte composition comprising one or more sulfur-containing aromatic compounds selected from the group consisting of the following sulfur-containing aromatic compounds [A] to [D] and a polymer electrolyte.
    Sulfur-containing aromatic compound [A]: A sulfur-containing aromatic compound represented by the following formula (1).
    Figure JPOXMLDOC01-appb-I000001
    (In Formula (1), Y 1 represents a divalent group containing a sulfur atom. C 1 to C 4 each represents a carbon atom. Ring Ar 01 contains C 1 and C 2 and has a substituent. An aromatic ring having 4 to 50 carbon atoms which may be optionally substituted, and ring Ar 02 represents an aromatic ring having 4 to 50 carbon atoms which may have a substituent, including C 3 and C 4. The substituent that 01 may have and the substituent which Ar 02 may have are a hydroxyl group, a halogeno group, a cyano group, a carboxy group, a phosphono group, a sulfo group, a formyl group, a mercapto group, and a methyl group, respectively. An aryl group having 4 to 20 carbon atoms which may have a substituent, an aryloxy group having 4 to 20 carbon atoms which may have a substituent, and 4 carbon atoms which may have a substituent. ~ 20 arylthio group, optionally substituted aroyl group having 5 to 21 carbon atoms And one or more groups selected from the group consisting of optionally substituted arylsulfonyl groups having 4 to 20 carbon atoms, wherein X 1 and X 2 are the same or different and each represents a hydrogen atom, a hydroxyl group A halogeno group, a cyano group, a carboxy group, a phosphono group, a sulfo group, a formyl group, a mercapto group, a methyl group, an aryl group having 4 to 20 carbon atoms which may have a substituent, and a substituent. An aryloxy group having 4 to 20 carbon atoms, an arylthio group having 4 to 20 carbon atoms which may have a substituent, an aroyl group having 5 to 21 carbon atoms which may have a substituent, or a substituent Represents an arylsulfonyl group having 4 to 20 carbon atoms which may have
    Sulfur-containing aromatic compound [B]: A sulfur-containing aromatic compound represented by the following formula (2).
    Figure JPOXMLDOC01-appb-I000002
    (In formula (2), Y 1 has the same meaning as above. Z 1 represents a direct bond or a divalent group represented by any of the following formulas (2-1) to (2-9). C Each of 5 to C 8 represents a carbon atom, and ring Ar 03 represents an aromatic ring having 4 to 50 carbon atoms which may have a substituent, including C 5 and C 6. Ring Ar 04 represents C It represents an aromatic ring having 4 to 50 carbon atoms which contains 7 and C 8 and may have a substituent.
    Figure JPOXMLDOC01-appb-I000003
    (In the formulas (2-1) to (2-9), E 1 represents a hydrogen atom, a hydroxyl group, a methyl group, a methoxy group, or an aromatic group having 4 to 50 carbon atoms.)
    Sulfur-containing aromatic compound [C]: Sulfur-containing aromatic compound represented by the following formula (3).
    Figure JPOXMLDOC01-appb-I000004
    (In Formula (3), Y 1 and Z 1 have the same meanings as above. C 9 to C 12 each represent a carbon atom. X 3 to X 6 are the same or different, and each represents a hydrogen atom, a hydroxyl group, A halogeno group, a cyano group, a carboxy group, a phosphono group, a sulfo group, a formyl group, a mercapto group, an optionally substituted alkyl group having 1 to 20 carbon atoms, and an optionally substituted carbon number An alkoxy group having 1 to 20 carbon atoms, an alkylthio group having 1 to 20 carbon atoms which may have a substituent, an aryl group having 3 to 20 carbon atoms which may have a substituent, and a substituent; An aryloxy group having 3 to 20 carbon atoms, an arylthio group having 3 to 20 carbon atoms which may have a substituent, an acyl group having 2 to 21 carbon atoms which may have a substituent, and a substituent An aroyl group having 4 to 21 carbon atoms, which may have a substituent If .Z 1 representing the optionally also be C 3-20 arylsulfonyl group, or a substituent and 1 carbon atoms which may have a 20 alkylsulfonyl group possessed a direct bond, X 4 and X 5 May be bonded to each other to form a ring.)
    Sulfur-containing aromatic compound [D]: Sulfur-containing aromatic compound represented by the following formula (4).
    Figure JPOXMLDOC01-appb-I000005
    (In Formula (4), Y 1 and Z 1 are as defined above. C 13 to C 16 each represent a carbon atom. Ring Ar 05 contains C 15 and C 16 and has a substituent. Represents an aromatic ring having 4 to 50 carbon atoms, X 7 and X 8 are the same or different and each represents a hydrogen atom, a hydroxyl group, a halogeno group, a cyano group, a carboxy group, a phosphono group, a sulfo group, a formyl group, A mercapto group, an optionally substituted alkyl group having 1 to 20 carbon atoms, an optionally substituted alkoxy group having 1 to 20 carbon atoms, and an optionally substituted carbon number An alkylthio group having 1 to 20 carbon atoms, an aryl group having 3 to 20 carbon atoms which may have a substituent, an aryloxy group having 3 to 20 carbon atoms which may have a substituent, and a substituent; May have an arylthio group having 3 to 20 carbon atoms and a substituent An optionally substituted acyl group having 2 to 21 carbon atoms, an optionally substituted aroyl group having 4 to 21 carbon atoms, an optionally substituted arylsulfonyl group having 3 to 20 carbon atoms, or a substituent. Represents an alkylsulfonyl group having 1 to 20 carbon atoms which may have a group.)
  2. 　前記高分子電解質組成物が含有する前記含硫黄芳香族化合物は、含硫黄芳香族化合物［Ｂ］~［Ｄ］からなる群より選ばれる一種以上の含硫黄芳香族化合物であることを特徴とする請求項１に記載の高分子電解質組成物。 The sulfur-containing aromatic compound contained in the polymer electrolyte composition is one or more sulfur-containing aromatic compounds selected from the group consisting of sulfur-containing aromatic compounds [B] to [D]. The polymer electrolyte composition according to claim 1.
  3. 　上記Ｙ１が硫黄原子またはスルフィニル基であることを特徴とする請求項１または２に記載の高分子電解質組成物。 The polymer electrolyte composition according to claim 1 or 2, wherein Y 1 is a sulfur atom or a sulfinyl group.
  4. 　上記含硫黄芳香族化合物［Ｂ］が下記式（６）で表されることを特徴とする請求項１~３のいずれかに記載の高分子電解質組成物。
    Figure JPOXMLDOC01-appb-I000006
    （式（６）中、Ｙ１およびＺ１はそれぞれ上記と同義である。Ｒ０１~Ｒ０８は、それぞれ同一または相異なり、水素原子、水酸基、ハロゲノ基、シアノ基、カルボキシ基、ホスホノ基、スルホ基、ホルミル基、メルカプト基、置換基を有していてもよい炭素数１~２０のアルキル基、置換基を有していてもよい炭素数１~２０のアルコキシ基、置換基を有していてもよい炭素数１~２０のアルキルチオ基、置換基を有していてもよい炭素数３~２０のアリール基、置換基を有していてもよい炭素数３~２０のアリールオキシ基、置換基を有していてもよい炭素数３~２０のアリールチオ基、置換基を有していてもよい炭素数２~２１のアシル基、置換基を有していてもよい炭素数４~２１のアロイル基、置換基を有していてもよい炭素数３~２０のアリールスルホニル基または置換基を有していてもよい炭素数１~２０のアルキルスルホニル基を表す。）     The polymer electrolyte composition according to any one of claims 1 to 3, wherein the sulfur-containing aromatic compound [B] is represented by the following formula (6).
    Figure JPOXMLDOC01-appb-I000006
    (In Formula (6), Y 1 and Z 1 are as defined above. R 01 to R 08 are the same or different, and each represents a hydrogen atom, a hydroxyl group, a halogeno group, a cyano group, a carboxy group, a phosphono group, A sulfo group, a formyl group, a mercapto group, an optionally substituted alkyl group having 1 to 20 carbon atoms, an optionally substituted alkoxy group having 1 to 20 carbon atoms, and a substituent. An optionally substituted alkylthio group having 1 to 20 carbon atoms, an aryl group having 3 to 20 carbon atoms which may have a substituent, an aryloxy group having 3 to 20 carbon atoms which may have a substituent, An arylthio group having 3 to 20 carbon atoms which may have a substituent, an acyl group having 2 to 21 carbon atoms which may have a substituent, and 4 to 21 carbon atoms which may have a substituent. An aroyl group having 3 to 20 carbon atoms which may have a substituent Have a Rusuruhoniru group or substituent represents an alkylsulfonyl group having 1 to 20 carbon atoms.)
  5. 　上記含硫黄芳香族化合物が、上記高分子電解質１００重量部に対して０．０１~３０重量部含有されることを特徴とする請求項１~４のいずれかに記載の高分子電解質組成物。 The polymer electrolyte composition according to any one of claims 1 to 4, wherein the sulfur-containing aromatic compound is contained in an amount of 0.01 to 30 parts by weight with respect to 100 parts by weight of the polymer electrolyte.
  6. 　上記高分子電解質が芳香族炭化水素系高分子電解質であることを特徴とする特徴とする請求項１~５のいずれかに記載の高分子電解質組成物。 6. The polymer electrolyte composition according to claim 1, wherein the polymer electrolyte is an aromatic hydrocarbon polymer electrolyte.
  7. 　上記高分子電解質がフッ素系高分子電解質であることを特徴とする特徴とする請求項１~５のいずれかに記載の高分子電解質組成物。 6. The polymer electrolyte composition according to claim 1, wherein the polymer electrolyte is a fluorine-based polymer electrolyte.
  8. 　請求項１~７のいずれかに記載の高分子電解質組成物を含有することを特徴とする高分子電解質膜。 A polymer electrolyte membrane comprising the polymer electrolyte composition according to any one of claims 1 to 7.
  9. 　請求項１~７のいずれかに記載の高分子電解質組成物と、触媒成分とを含有することを特徴とする触媒組成物。 A catalyst composition comprising the polymer electrolyte composition according to any one of claims 1 to 7 and a catalyst component.
  10. 　請求項８に記載の高分子電解質膜および請求項９に記載の触媒組成物からなる群より選ばれる１種以上を有することを特徴とする膜電極接合体。 A membrane electrode assembly comprising at least one selected from the group consisting of the polymer electrolyte membrane according to claim 8 and the catalyst composition according to claim 9.
  11. 　請求項１０に記載の膜電極接合体を有することを特徴とする固体高分子形燃料電池。 A polymer electrolyte fuel cell comprising the membrane electrode assembly according to claim 10.
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