JP2010135280A - Proton conductive membrane and manufacturing method thereof, membrane-electrode assembly, and solid polymer fuel cell - Google Patents

Abstract

【選択図】なしThe present invention provides a proton conducting membrane excellent in dry and wet cycle durability and a polymer electrolyte fuel cell having high output and excellent durability.
[A] A polyarylene system comprising a condensed aromatic ring structural unit represented by the formula (2) and a structural unit having a sulfonic acid group represented by the following formula (13) A proton conductive membrane containing a copolymer and [B] a fluorine-containing polymer, having a continuous phase consisting of [A] a polyarylene copolymer and a dispersed phase consisting of [B] a fluorine-containing polymer A proton conducting membrane characterized by comprising:

[Selection figure] None

Description

  The present invention relates to a proton conductive membrane reinforced by using a polyarylene copolymer and a fluorine-containing polymer, a method for producing the same, and uses of the proton conductive membrane.

  A fuel cell is a power generator that directly extracts electricity by electrochemically reacting hydrogen obtained by reforming hydrogen gas or various hydrocarbon fuels (natural gas, methane, etc.) and oxygen in the air. It is attracting attention as a pollution-free power generation system that can directly convert the chemical energy of fuel into electrical energy with high efficiency.

  Such a fuel cell is composed of a pair of electrode membranes (fuel electrode and air electrode) carrying a catalyst and a proton conductive electrolyte membrane (referred to as proton conductive membrane) sandwiched between the electrode membranes. The fuel electrode catalyst separates hydrogen ions and electrons into hydrogen ions that pass through the proton conducting membrane and react with oxygen at the air electrode to become water.

  In recent years, this fuel cell is required to have high power generation performance. In order to increase the power generation output, it is required to be used at a high temperature during power generation. For this reason, proton conductive membranes used for fuel cells have high proton conductivity under a wide range of environments, particularly at high temperatures. Was demanded.

  As such a proton conductive membrane, a polymer having a sulfonic acid group has attracted attention. Further, as a proton conducting membrane having high proton conductivity, the present applicant also discloses Japanese Patent Application Laid-Open No. 2004-345997 (Patent Document 1), Japanese Patent Application Laid-Open No. 2004-346163 (Patent Document 2), and Japanese Patent Application Laid-Open No. 2004-346164. (Patent Document 3) proposes a polyarylene polymer having a sulfonic acid group.

  However, these polymers are made of a polyarylene-based copolymer that is rigid, so that the toughness is low. Also, when a proton conductive membrane made of these polymers is used in a fuel cell, the durability of the wet and dry cycle is not necessarily limited. It was not enough.

  On the other hand, it has hitherto been known to use sulfonated polyphenylene oxide as a proton conducting membrane. For example, Special Table 2002-502539 (Patent Document 4) gives high conductivity, flexibility, mechanical strength, and low swelling rate in water by uniformly blending sulfonated polyphenylene oxide and polyvinylidene fluoride. Is disclosed.

  However, in the film described in Patent Document 4, a reversible elimination reaction of a sulfonic acid group or a polyphenylene oxide crosslinking reaction involving sulfonic acid may occur at a high temperature. As a result, there is a problem that proton conductivity is reduced, membrane embrittlement or the like occurs, power generation output of the fuel cell is reduced, or power generation is disabled when the membrane is broken.

JP 2004-345997 A JP 2004-346163 A JP 2004-346164 A JP 2002-502539 A

  The present invention provides a proton conductive membrane having high strength, excellent toughness, long-term durability, particularly dry and wet cycle durability, and a solid polymer fuel cell having high output and excellent durability. With the goal.

  Under such circumstances, as a result of intensive studies to solve the above-mentioned problems, a proton conducting membrane that solves all of the above problems can be obtained by using a specific sulfonated polyarylene and a fluorine-containing polymer. As a result, the present invention has been completed.

That is, the configuration of the present invention is as follows.
[1] [A] a condensed aromatic ring structural unit represented by the formula (2);
A polyarylene-based copolymer comprising a structural unit having a sulfonic acid group represented by the following formula (13);
[B] a proton conducting membrane containing a fluorine-containing polymer,
[A] A proton conducting membrane having a continuous phase composed of a polyarylene copolymer and a dispersed phase composed of [B] a fluorine-containing polymer.

［式（２）中、Ａ、Ｄは直接結合、−Ｏ−、−Ｓ−、−ＣＯ−、−ＳＯ₂−、−ＳＯ−、−ＣＯＮＨ−、−ＣＯＯ−、−（ＣＦ₂）_i−（ｉは１〜１０の整数である）、−（ＣＨ₂）_j−（ｊは１〜１０の整数である）、−ＣＲ'₂−（Ｒ'は脂肪族炭化水素基、芳香族炭化水素基またはハロゲン化炭化水素基を示す）、シクロヘキシリデン基およびフルオレニリデン基からなる群より選ばれた少なくとも１種の構造を示し、Ｂは酸素原子または硫黄原子を示し、Ｐｈは縮合芳香族環構造を有する２価の基を示し、Ｒ₁〜Ｒ₂₀は、互いに同一であっても異なっていてもよく、水素原子、フッ素原子、アルキル基、一部またはすべてがハロゲン化されたハロゲン化アルキル基、アリル基、アリール基、ニトロ基およびニトリル基からなる群より選ばれる少なくとも１種の原子または基を示す。ｌ、ｍは０〜４の整数を示し、ｑは２以上の整数を示す。ｔは０〜４の整数を示す。ｎ、ｐは各構成単位の組成比を示し、ｐは０から１であり、ｎ＋ｐ＝１である。

Wherein (2), A, D is a direct bond, -O -, - S -, - CO -, - SO 2 -, - SO -, - CONH -, - COO -, - (CF 2) i - (I is an integer of 1 to 10), — (CH ₂ ) _j — (j is an integer of 1 to 10), —CR ′ ₂ — (R ′ is an aliphatic hydrocarbon group, aromatic hydrocarbon) Group or a halogenated hydrocarbon group), at least one structure selected from the group consisting of a cyclohexylidene group and a fluorenylidene group, B represents an oxygen atom or a sulfur atom, and Ph represents a condensed aromatic ring structure R _{1 to} R ₂₀ may be the same or different from each other, and may be a hydrogen atom, a fluorine atom, an alkyl group, or a halogenated alkyl group in which part or all of them are halogenated. , Allyl group, aryl group, nitro group and nitrile group It represents at least one atom or group. l and m represent an integer of 0 to 4, and q represents an integer of 2 or more. t shows the integer of 0-4. n and p show the composition ratio of each structural unit, p is 0 to 1, and n + p = 1.

（式（１３）中、Ｚは直接結合または、−Ｏ−、−Ｓ−からなる群より選ばれた少なくとも１種の構造を示し、Ｙは、−ＣＯ−、−ＳＯ₂−、−ＳＯ−、−ＣＯＮＨ−、−ＣＯＯ−、−（ＣＦ₂）_l'−（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種の構造を示す。Ａｒは−ＳＯ₃Ｈ、−Ｏ（ＣＨ₂）_hＳＯ₃Ｈまたは−Ｏ（ＣＦ₂）_hＳＯ₃Ｈで表される置換基を有する芳香族基を示す（ｈは１〜１２の整数を示す）。ｃは０〜１０の整数を示し、ｄは０〜１０の整数を示し、ｋは１〜４の整数を示す。）
各構成単位の端部における単線のうち、一方に置換基が表示されていないものは隣り合う構成単位との接続を意味する。］
[２]前記ポリアリーレン系共重合体［Ａ］が、下記式（９）で表される含窒素複素環基を有する構成単位を含むことを特徴とする[１]に記載のプロトン伝導膜。

(In formula (13), Z represents a direct bond or at least one structure selected from the group consisting of —O— and —S—, and Y represents —CO—, —SO ₂ —, —SO—. , —CONH—, —COO—, — (CF ₂ ) _{1 ′} — (wherein 1 ′ is an integer of 1 to 10), and —C (CF ₃ ) ₂ —. Ar represents an aromatic group having a substituent represented by —SO ₃ H, —O (CH ₂ ) _h SO ₃ H or —O (CF ₂ ) _h SO ₃ H (h represents 1 to 12). C represents an integer of 0 to 10, d represents an integer of 0 to 10, and k represents an integer of 1 to 4.)
Of the single wires at the end of each structural unit, one not having a substituent displayed on one side means connection with an adjacent structural unit. ]
[2] The proton conducting membrane according to [1], wherein the polyarylene copolymer [A] includes a structural unit having a nitrogen-containing heterocyclic group represented by the following formula (9).

式（９）中、Ｚは直接結合または、−Ｏ−、−Ｓ−からなる群より選ばれた少なくとも１種の構造を示し、Ｙは、−ＣＯ−、−ＳＯ₂−、−ＳＯ−、−ＣＯＮＨ−、−ＣＯＯ−、−（ＣＦ₂）_l'−（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、Ｒ₂₁は含窒素複素環基を示す。ｂは１〜５の整数を示し、ａは０〜４の整数を示す。

In formula (9), Z represents a direct bond or at least one structure selected from the group consisting of —O— and —S—, and Y represents —CO—, —SO ₂ —, —SO—, -CONH -, - COO -, - (CF 2) l '- (l' is an integer of 1 to 10), - at least one structure selected from the group consisting of - C (CF _{3) 2} R ₂₁ represents a nitrogen-containing heterocyclic group. b shows the integer of 1-5, a shows the integer of 0-4.

[3] The fluorine-containing polymer [B] is selected from vinylidene fluoride polymers, tetrafluoroethylene-propylene copolymers, fluorine-containing olefin / vinyl ether copolymers, and fluorine-containing olefin / vinyl ester copolymers. The proton conducting membrane according to [1] or [2], which is at least one kind.
[4] The proton conduction according to any one of [1] to [3], wherein the average value of the major axis of the dispersed phase composed of the fluorine-containing polymer contained in the proton conducting membrane is 0.001 to 1.0 μm. film.
[5] The weight ratio of the polyarylene copolymer [A] and the fluorine-containing polymer [B] in the proton conducting membrane is 99: 1 to 50:50, according to [1] to [4] The proton conductive membrane according to any one of the above.
[6] In the formula (2), Ph is a divalent group derived from an aromatic ring selected from the group consisting of naphthalene, anthracene, tetracene, and pentacene. [1] to [5] The proton conductive membrane according to any one of the above.
[7] The proton conductive membrane according to any one of [1] to [6], wherein the condensed aromatic ring structural unit is represented by the following formula (3);

［式（３）中、Ａは直接結合、−Ｏ−、−ＣＯ−、−ＳＯ₂−、−ＳＯ−、−（ＣＦ₂）_i−（ｉは１〜１０の整数である）、−（ＣＨ₂）_j−（ｊは１〜１０の整数である）、−ＣＲ'₂−（Ｒ'は脂肪族炭化水素基、芳香族炭化水素基またはハロゲン化炭化水素基を示す）、シクロヘキシリデン基およびフルオレニリデン基からなる群より選ばれた少なくとも１種の構造を示し、
Ｄは直接結合、−Ｏ−、−ＣＯ−、−（ＣＨ₂）_j−（ｊは１〜１０の整数である）および−ＣＲ'₂−（Ｒ'は脂肪族炭化水素基、芳香族炭化水素基またはハロゲン化炭化水素基を示す）からなる群より選ばれた少なくとも１種の構造を示し、
Ｐｈは縮合芳香族環を有する２価の基を示し、Ｒ₁〜Ｒ₂₀は互いに同一であっても異なっていてもよく、水素原子、フッ素原子、アルキル基、一部またはすべてがハロゲン化されたハロゲン化アルキル基、アリル基、アリール基、ニトロ基およびニトリル基からなる群より選ばれる少なくとも１種の原子または基を示す。

Wherein (3), A is a direct bond, -O -, - CO -, - SO 2 -, - SO -, - (CF 2) i - (i is an integer of 1 to 10), - ( CH ₂ ) _j — (j is an integer of 1 to 10), —CR ′ ₂ — (R ′ represents an aliphatic hydrocarbon group, an aromatic hydrocarbon group or a halogenated hydrocarbon group), cyclohexylidene At least one structure selected from the group consisting of a group and a fluorenylidene group,
D is a direct bond, —O—, —CO—, — (CH ₂ ) _j — (j is an integer of 1 to 10) and —CR ′ ₂ — (R ′ is an aliphatic hydrocarbon group, aromatic carbonization. Represents at least one structure selected from the group consisting of a hydrogen group or a halogenated hydrocarbon group),
Ph represents a divalent group having a condensed aromatic ring, R _{1 to} R ₂₀ may be the same or different from each other, and a hydrogen atom, a fluorine atom, an alkyl group, a part or all of them are halogenated. And at least one atom or group selected from the group consisting of a halogenated alkyl group, an allyl group, an aryl group, a nitro group and a nitrile group.

l represents an integer of 0 to 4, and q represents an integer of 2 or more. t shows the integer of 0-4.
n and p show the composition ratio of each structural unit, p is 0 to 1, and n + p = 1.
Among the single lines at the end of the structural unit, those not having a substituent displayed on one side mean connection with the adjacent structural unit. ]

[8] The proton conducting membrane according to [7], wherein the condensed aromatic ring structural unit is represented by the following formula (4):

［式（４）中、Ｄは、−Ｏ−、−ＣＲ'₂−（Ｒ'は脂肪族炭化水素基、芳香族炭化水素基またはハロゲン化炭化水素基を示す）からなる群より選ばれた少なくとも１種の構造を示す。

[In the formula (4), D is selected from the group consisting of —O— and —CR ′ ₂ — (R ′ represents an aliphatic hydrocarbon group, an aromatic hydrocarbon group or a halogenated hydrocarbon group). At least one structure is shown.

P is at least one structure selected from structures represented by the following formulas (5-1) to (5-3),
Ph is a structure represented by the following formula (6).

q represents an integer of 2 or more. t shows the integer of 0-4.
n and p show the composition ratio of each structural unit, p is 0 to 1, and n + p = 1.
Among the single lines at the end of the structural unit, those not having a substituent displayed on one side mean connection with the adjacent structural unit. ]

［９］［Ａ］前記式（２）で表されることを特徴とする縮合芳香族環構成単位と、式（１３）で表されるスルホン酸基を有する構成単位とを含むポリアリーレン系共重合体、［Ｂ］含フッ素ポリマーを、
溶媒に溶解ないし分散した後、製膜することを特徴とする［Ａ］ポリアリーレン系共重合体からなる連続相と［Ｂ］含フッ素ポリマーからなる分散相を有するプロトン伝導膜の製造方法。

[9] [A] A polyarylene-based copolymer comprising a condensed aromatic ring structural unit represented by the formula (2) and a structural unit having a sulfonic acid group represented by the formula (13) Polymer, [B] fluorine-containing polymer,
A method for producing a proton conducting membrane having a continuous phase composed of [A] a polyarylene copolymer and a dispersed phase composed of [B] a fluorine-containing polymer, wherein the membrane is formed after being dissolved or dispersed in a solvent.

[10] A membrane-electrode assembly comprising the proton conducting membrane according to any one of [1] to [8], and a catalyst layer and a gas diffusion layer on both sides of the proton conducting membrane.
[11] A solid polymer electrolyte fuel cell having the membrane-electrode assembly according to [10].

  Since the proton conductive membrane of the present invention uses a specific polyarylene copolymer and a fluorine-containing polymer, it has flexibility as well as rigidity, and thus has excellent wet / dry cycle durability and high toughness. In addition, a proton conductive membrane having both high proton conductivity of polyarylene resin and high heat resistance, chemical resistance, chemical resistance and the like of a fluorine-containing polymer can be obtained. Furthermore, since it has excellent dry / wet cycle durability and high toughness, the polymer electrolyte fuel cell having this proton conducting membrane can obtain a stable high output even if it is operated for a long period of time.

The proton conducting membrane of the present invention comprises [A] a polyarylene copolymer and [B] a fluorine-containing polymer.
[A] Polyarylene-based copolymer The polyarylene-based copolymer used in the present invention includes a condensed aromatic ring structural unit and a structural unit having a sulfonic acid group.

[Condensed aromatic ring structural unit]
The condensed aromatic ring structural unit which the copolymer of this invention has is represented by following formula (1). By including such a structural unit, a hydrophobic portion can be imparted to the polymer. Moreover, since it has a condensed aromatic ring, the hot water resistance of the polymer can be improved.

上記式中、Ａｒ²¹、Ａｒ²²、Ａｒ²³、Ａｒ²⁴は、それぞれ独立に、ベンゼン環、縮合芳香環、または含窒素複素環からなる群より選ばれた少なくとも１種の構造を有する２価の基を示す。

In the above formula, Ar ²¹ , Ar ²² , Ar ²³ , Ar ²⁴ are each independently a divalent structure having at least one structure selected from the group consisting of a benzene ring, a condensed aromatic ring, or a nitrogen-containing heterocyclic ring. Indicates a group.

However, Ar ²¹ , Ar ²² , Ar ²³ , and Ar ²⁴ are such that some or all of the hydrogen atoms are fluorine atoms, nitro groups, nitrile groups, or some or all of the hydrogen atoms are fluorine-substituted. It may be substituted with at least one atom or group selected from the group consisting of an alkyl group, an allyl group or an aryl group.

A and D are each independently a direct bond or —CO—, —SO ₂ —, —SO—, — (CF ₂ ) ₁ — (l is an integer of 1 to 10), — (CH ₂ ). _l— (l is an integer of 1 to 10), —CR ′ ₂ — (R ′ represents an aliphatic hydrocarbon group, an aromatic hydrocarbon group and a halogenated hydrocarbon group), a cyclohexylidene group, a fluorenylidene At least one structure selected from the group consisting of a group, —O—, or —S—;
B is an oxygen atom or a sulfur atom,
s and t each independently represent an integer of 0 to 4, and r represents 0 or an integer of 1 or more.

  The structural unit represented by the above formula (1) is preferably a structure represented by the following formula (2).

式（２）中、ｌ、ｍは０〜４の整数を示し、ｑは２以上の整数を示す。ｎ、ｐは各構成単位の組成比を示し、ｐは０から１の値であり、ｎ＋ｐ＝１である。これらのうち、ｍは０か１が好ましく、ｌは０か１が好ましい。また、ｐは０．０１〜１の値をとることが好ましく、より好ましくは０．１〜１、特に好ましくは０．０５〜１である。ｔは０〜４の整数を示し、好ましくは０〜２、より好ましくは０または１である。

In formula (2), l and m represent an integer of 0 to 4, and q represents an integer of 2 or more. n and p represent the composition ratio of each structural unit, p is a value from 0 to 1, and n + p = 1. Of these, m is preferably 0 or 1, and l is preferably 0 or 1. Further, p preferably takes a value of 0.01 to 1, more preferably 0.1 to 1, and particularly preferably 0.05 to 1. t represents an integer of 0 to 4, preferably 0 to 2, more preferably 0 or 1.

A is a direct bond, —O—, —S—, —CO—, —SO ₂ —, —SO—, —CONH—, —COO—, — (CF ₂ ) _i — (i is an integer of 1 to 10) A), — (CH ₂ ) _j — (j is an integer of 1 to 10), —CR ′ ₂ — (R ′ represents an aliphatic hydrocarbon group, an aromatic hydrocarbon group or a halogenated hydrocarbon group). ), At least one structure selected from the group consisting of a cyclohexylidene group and a fluorenylidene group.

Here, as specific examples of R ′ of —CR ′ ₂ —, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, t-butyl group, propyl group, octyl group, decyl group, An octadecyl group, a phenyl group, a trifluoromethyl group, etc. are mentioned. Of these, a direct bond, —O—, and —CR ′ ₂ — (R ′ represents an aliphatic hydrocarbon group, an aromatic hydrocarbon group, or a halogenated hydrocarbon group) are preferable.

B represents an oxygen atom or a sulfur atom, preferably an oxygen atom.
Ph represents a divalent group having a condensed aromatic ring structure, and examples thereof include a divalent group derived from a ring structure such as a naphthalene ring, an anthracene ring, a tetracene ring, a pentacene ring, etc. Among them, a divalent group derived from a naphthalene ring Are preferred. By containing these, water resistance can be provided to the polymer which uses the aromatic compound represented by Formula (1) as a monomer.

D is a direct bond, —O—, —S—, —CO—, —SO ₂ —, —SO—, —CONH—, —COO—, — (CF ₂ ) _i — (i is an integer of 1 to 10) ), — (CH ₂ ) _j — (j is an integer of 1 to 10), —CR ′ ₂ — (R ′ represents an aliphatic hydrocarbon group, an aromatic hydrocarbon group or a halogenated hydrocarbon group. And at least one structure selected from the group consisting of a cyclohexylidene group and a fluorenylidene group.

Of the single wires at the end of each structural unit, one not having a substituent displayed on one side means connection with an adjacent structural unit.
Here, as specific examples of R ′ of —CR ′ ₂ —, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, t-butyl group, propyl group, octyl group, decyl group, An octadecyl group, a phenyl group, a trifluoromethyl group, etc. are mentioned. Of these, a direct bond, —O—, and —CR ′ ₂ — (R ′ represents an aliphatic hydrocarbon group, an aromatic hydrocarbon group, or a halogenated hydrocarbon group) are preferable.

R _{1 to} R ₂₀ may be the same as or different from each other, and may be a hydrogen atom, a fluorine atom, an alkyl group, a halogenated alkyl group in which some or all are halogenated, an allyl group, an aryl group, a nitro group, and At least one atom or group selected from the group consisting of nitrile groups is shown.

  It is preferable that the condensed aromatic ring structural unit is represented by the following formula (3).

［式（３）中、Ａは直接結合、−Ｏ−、−ＣＯ−、−ＳＯ₂−、−ＳＯ−、−（ＣＦ₂）_i−（ｉは１〜１０の整数である）、−（ＣＨ₂）_j−（ｊは１〜１０の整数である）、−ＣＲ'₂−（Ｒ'は脂肪族炭化水素基、芳香族炭化水素基またはハロゲン化炭化水素基を示す）、シクロヘキシリデン基およびフルオレニリデン基からなる群より選ばれた少なくとも１種の構造を示し、
Ｄは直接結合、−Ｏ−、−ＣＯ−、−（ＣＨ₂）_j−（ｊは１〜１０の整数である）および−ＣＲ'₂−（Ｒ'は脂肪族炭化水素基、芳香族炭化水素基またはハロゲン化炭化水素基を示す）−からなる群より選ばれた少なくとも１種の構造を示し、
Ｐｈは縮合芳香族環構造を有する２価の基を示し、Ｒ₁〜Ｒ₂₀は互いに同一であっても異なっていてもよく、水素原子、フッ素原子、アルキル基、一部またはすべてがハロゲン化されたハロゲン化アルキル基、アリル基、アリール基、ニトロ基およびニトリル基からなる群より選ばれる少なくとも１種の原子または基を示す。

Wherein (3), A is a direct bond, -O -, - CO -, - SO 2 -, - SO -, - (CF 2) i - (i is an integer of 1 to 10), - ( CH ₂ ) _j — (j is an integer of 1 to 10), —CR ′ ₂ — (R ′ represents an aliphatic hydrocarbon group, an aromatic hydrocarbon group or a halogenated hydrocarbon group), cyclohexylidene At least one structure selected from the group consisting of a group and a fluorenylidene group,
D is a direct bond, -O -, - CO -, - (CH 2) j - (j is an integer of 1 to 10) and -CR _'2 - (R' is an aliphatic hydrocarbon group, an aromatic hydrocarbon Represents a hydrogen group or a halogenated hydrocarbon group), and represents at least one structure selected from the group consisting of:
Ph represents a divalent group having a condensed aromatic ring structure, R _{1 to} R ₂₀ may be the same or different from each other, and a hydrogen atom, a fluorine atom, an alkyl group, part or all of which are halogenated And at least one atom or group selected from the group consisting of a halogenated alkyl group, an allyl group, an aryl group, a nitro group, and a nitrile group.

l and m represent an integer of 0 to 4, and q represents an integer of 2 or more. t shows the integer of 0-4.
n and p show the composition ratio of each structural unit, p is 0 to 1, and n + p = 1. ].
Furthermore, what is represented by following formula (4) as this condensed aromatic ring structural unit is more preferable.

［式（４）中、Ｄは、−Ｏ−、−ＣＲ'₂−（Ｒ'は脂肪族炭化水素基または芳香族炭化水素基を示す）からなる群より選ばれた少なくとも１種の構造を示す。

Wherein (4), D is, -O -, - CR - a _'2 (R' represents an aliphatic hydrocarbon group or an aromatic hydrocarbon group) at least one structure selected from the group consisting of Show.

P is at least one structure selected from structures represented by the following formulas (5-1) to (5-3),
Ph is a structure represented by the following formula (6).
q represents an integer of 2 or more. t shows the integer of 0-4.
n and p show the composition ratio of each structural unit, p is 0 to 1, and n + p = 1. ].

  In order to improve water resistance, it is desirable to introduce more condensed aromatic ring structural units (as the value of p is larger). However, when more condensed ring structural units are introduced, the solubility of the product is remarkably lowered and handling may be difficult. In such a case, the use of two or more different condensed aromatic ring structural units makes it possible to introduce more condensed aromatic ring structural units while maintaining the solubility of the product. It is preferable that p is in the range of 0.01-1.

このような構成単位として具体的には、以下のものが例示される。

Specific examples of such structural units include the following.

  For example, when p is 0, ie, having no condensed aromatic ring, the following may be mentioned.

また、ｐが０以外のもの、すなわち縮合芳香族環を有するものとしては、以下のものが挙げられる。

Examples of p having a value other than 0, that is, having a condensed aromatic ring include the following.

縮合芳香族環構成単位を含有していると、共重合体の疎水性が著しく向上する。このため、従来と同様のプロトン伝導性を具備しながら、優れた熱水耐性を付与することができる。

When the condensed aromatic ring structural unit is contained, the hydrophobicity of the copolymer is remarkably improved. For this reason, the outstanding hot water tolerance can be provided, providing the proton conductivity similar to the past.

[Structural unit having nitrogen-containing heterocyclic group]
In the present invention, a structural unit having a nitrogen-containing heterocyclic group may be contained, and the nitrogen-containing heterocyclic group has a structure represented by the following formula (7-1).
− (R ^s ) _e − (V−R ^h ) _f (7-1)
In the formula, V is not particularly limited as long as it is an electron-withdrawing group, but is preferably selected from the group consisting of —O—, —S—, direct bond, —CO—, —SO ₂ — or — or —SO—. It shows at least one selected structure.

R ^s is a direct bond or any divalent organic group that is not particularly limited. The divalent organic group may be any hydrocarbon group having 1 to 20 carbon atoms, and specific examples include alkylene groups such as methylene group and ethylene group, and aromatic rings such as phenylene group.

R ^s may be a group represented by —W—Ar ⁹ —.
As the structure having a nitrogen-containing heterocyclic group of the formula (7-1), specifically, a structure represented by the following formula (7-2) is preferable.
-R ^s -V-R ^h (7-2)
In the above formula, Ar ⁹ represents a divalent group having at least one structure selected from the group consisting of a benzene ring, a condensed aromatic ring, and a nitrogen-containing heterocyclic ring, which may be substituted with a fluorine atom. .

e represents an integer of 0 to 4, and f represents an integer of 1 to 5. W represents —CO—, —SO ₂ —, —SO—, — (CF ₂ ) _u — (u is an integer of 1 to 10), —C (CF ₃ ) ₂ —, or a group consisting of direct bonds. It shows at least one selected structure.

R ^h represents a nitrogen-containing heterocyclic group, and examples thereof include 5- and 6-membered ring structures containing nitrogen. Further, the number of nitrogen atoms in the heterocycle is not particularly limited as long as it is 1 or more, and the heterocycle may contain oxygen or sulfur in addition to nitrogen.

Specific examples of the nitrogen-containing heterocyclic group constituting R ^h include pyrrole, thiazole, isothiazole, oxazole, isoxazole, pyridine, imidazole, imidazoline, pyrazole, 1,3,5-triazine, pyrimidine, pyritazine, and pyrazine. , Indole, quinoline, isoquinoline, bryne, benzimidazole, benzoxazole, benzthiazole, tetrazole, tetrazine, triazole, carbazole, acridine, quinoxaline, quinazoline It is a group having a structure in which atoms are extracted.

  These nitrogen-containing heterocyclic groups may have a substituent. Examples of the substituent include alkyl groups such as a methyl group, an ethyl group, and a propyl group, and aryl groups such as a phenyl group, a toluyl group, and a naphthyl group. Group, cyano group, fluorine atom and the like.

  The structural unit having a nitrogen-containing heterocyclic group contained in the copolymer of the present invention is represented by the following formula (8).

上記式(8)中、Ａｒ¹⁰は、ベンゼン環、縮合芳香環、含窒素複素環からなる群より選ばれた少なくとも１種の構造を有する２価の基を示す。ただし、Ａｒ¹⁰は、その水素原子の一部又はすべてが、フッ素原子、ニトロ基、ニトリル基、又は水素原子の一部またはすべてがフッ素置換されていてもよいアルキル基、アリル基若しくはアリール基からなる群より選ばれた少なくとも１種の原子または基で置換されていてもよい。

In the above formula (8), Ar ¹⁰ represents a divalent group having at least one structure selected from the group consisting of a benzene ring, a condensed aromatic ring, and a nitrogen-containing heterocyclic ring. However, Ar ¹⁰ is a part of or all of the hydrogen atoms from a fluorine atom, a nitro group, a nitrile group, or an alkyl group, an allyl group or an aryl group in which part or all of the hydrogen atoms may be substituted with fluorine. It may be substituted with at least one atom or group selected from the group consisting of

In the formula (8), V, e, f, R ^s and R ^h are the same as those in the formulas (7-1) and (7-2).
The structure having a nitrogen-containing heterocyclic group preferably has a structure represented by the following formula (7) in the sulfonated polyarylene of the present invention.

式（７）中、Ｖ、ｅ、ｆ、Ｒ^sおよびＲ^hは、式（８）の場合と同様である。構成単位の端部における単線のうち、一方に置換基が表示されていないものは隣り合う構成単位との接続を意味する。

In formula (7), V, e, f, R ^s and R ^h are the same as in formula (8). Among the single lines at the end of the structural unit, those not having a substituent displayed on one side mean connection with the adjacent structural unit.

In the above formula (7), the nitrogen-containing heterocyclic group R ^h is preferably a pyridine ring. In the case of a pyridine ring, since the basicity of N is originally low among nitrogen-containing heterocycles, the property of improving proton conductivity in a low humidity region is exhibited.

In the above formula (7), V is preferably —CO— or —SO ₂ —. When -CO- is combined with a pyridine ring, it tends to have a thermally stable structure due to the stabilization effect by conjugation. In addition, —SO ₂ — lowers the electron density and further suppresses the basicity of nitrogen, whereby proton conductivity in a low humidity region can be particularly enhanced.

The aromatic ring of the main chain and the electron-withdrawing group Z are preferably bonded directly from the viewpoint of stability, but an arbitrary divalent group (that is, R ^s ) is interposed as long as the effect of the present invention is not impaired. You may do it. Here, the interposition structure is not particularly limited as long as it is a divalent organic group having 1 to 20 carbon atoms.

  By using a copolymer having a structural unit having a nitrogen-containing heterocyclic group, a proton conductive membrane having high sulfonic acid stability at high temperatures can be obtained without impairing proton conductivity.

[Structural unit having sulfonic acid group]
The copolymer of the present invention can contain a structural unit having a sulfonic acid group. The structural unit having a sulfonic acid group is a structural unit having a structure represented by the following formula (10). By having a sulfonic acid group, a copolymer having proton conductivity can be obtained.

上記式中、Ａｒ¹²、Ａｒ¹³は、各々独立に、フッ素原子で置換されていてもよい、ベンゼン環、縮合芳香環（ナフタレン環など）、含窒素複素環からなる群より選ばれた少なくとも１種の構造を示す。

In the above formula, Ar ¹² and Ar ¹³ are each independently at least one selected from the group consisting of a benzene ring, a condensed aromatic ring (such as a naphthalene ring), and a nitrogen-containing heterocyclic ring, which may be substituted with a fluorine atom. The structure of the species is shown.

Y is —CO—, —SO ₂ —, —SO—, — (CF ₂ ) _u — (u is an integer of 1 to 10), —C (CF ₃ ) ₂ —, or a group consisting of direct bonds. It shows at least one selected structure.
Z is —O—, —S—, direct bond, —CO—, —SO ₂ —, —SO—, —CONH—, —COO—, — (CH ₂ ) ₁ — (l is an integer of 1 to 10) And at least one structure selected from the group consisting of —C (CH ₃ ) ₂ —.

R ¹¹ is at least one selected from the group consisting of a direct bond, —O (CH ₂ ) _p —, —O (CF ₂ ) _p —, — (CH ₂ ) _p —, and — (CF ₂ ) _p —. (P represents an integer of 1 to 12).

R ¹² and R ¹³ each independently represent at least one structure selected from the group consisting of a hydrogen atom, an alkali metal atom, and an aliphatic hydrocarbon group. However, at least one of all R ¹² and R ¹³ included in the above formula is a hydrogen atom.

x ¹ is an integer of 0 to 4, x ² is an integer of from 1 to 5, a is an integer of 0 to 1, b1 and b2 represent an integer of 0 to 3.
The structural unit having a sulfonic acid group represented by the above formula (10) preferably has a structure represented by the following formula (11).

式（１１）中、Ｙは−ＣＯ−、−ＳＯ₂−、−ＳＯ−、−ＣＯＮＨ−、−ＣＯＯ−、−（ＣＦ₂）_l'−（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種の構造を示す。このうち、−ＣＯ−、−ＳＯ₂−が好ましい。

In formula (11), Y represents —CO—, —SO ₂ —, —SO—, —CONH—, —COO—, — (CF ₂ ) _{1 ′} — (wherein 1 ′ is an integer of 1 to 10), -C (CF _{3) 2} - represents at least one structure selected from the group consisting of. Of these, —CO— and —SO ₂ — are preferable.

Z represents a direct bond or at least one structure selected from the group consisting of —O— and —S—. Among these, a direct bond and -O- are preferable.
Ar is an aromatic group having a substituent represented by —SO ₃ H or —O (CH ₂ ) _h SO ₃ H or —O (CF ₂ ) _h SO ₃ H (h represents an integer of 1 to 12). Indicates.

Specific examples of the aromatic group include a phenyl group, a naphthyl group, an anthryl group, and a phenanthryl group. Of these groups, a phenyl group and a naphthyl group are preferable. The aromatic group needs to be substituted with at least one substituent represented by the above-described —SO ₃ H or —O (CH ₂ ) _h SO ₃ H or —O (CF ₂ ) _h SO ₃ H. In the case of a naphthyl group, it is preferable that two or more are substituted.

c is an integer of 0 to 10, preferably 0 to 2, d is an integer of 0 to 10, preferably 0 to 2, and k is an integer of 1 to 4.
As a preferable combination of the values of c and d and the structures of Y, Z and Ar,
(1) a structure in which c = 0, d = 0, Y is —CO—, and Ar is a phenyl group having —SO ₃ H as a substituent;
(2) a structure in which c = 1, d = 0, Y is —CO—, Z is —O—, and Ar is a phenyl group having —SO ₃ H as a substituent;
(3) c = 1, a d = 1, k = 1, Y is -CO-, Z is -O-, and the structure Ar is a phenyl group having a -SO ₃ H as a substituent,
(4) a structure in which c = 1, d = 0, Y is —CO—, and Ar is a naphthyl group having two —SO ₃ H as substituents;
(5) c = 1, d = 0, Y is —CO—, Z is —O—, and Ar is a phenyl group having —O (CH ₂ ) ₄ SO ₃ H as a substituent. Examples include structures.

  The structural unit having a sulfonic acid group can also be represented by the following formula (12a).

上記式中、Ａｒ¹¹、Ａｒ¹²、Ａｒ¹³は、それぞれ独立に、フッ素原子で置換されていてもよい、ベンゼン環、縮合芳香環（ナフタレン環など）、含窒素複素環からなる群より選ばれた少なくとも１種の構造を有する２価の基を示す。

In the above formula, Ar ¹¹ , Ar ¹² and Ar ¹³ are each independently selected from the group consisting of a benzene ring, a condensed aromatic ring (such as a naphthalene ring) and a nitrogen-containing heterocyclic ring which may be substituted with a fluorine atom. And a divalent group having at least one structure.

Y is —CO—, —SO ₂ —, —SO—, — (CF ₂ ) _u — (u is an integer of 1 to 10), —C (CF ₃ ) ₂ —, or a group consisting of a direct bond. At least one structure selected from the above is shown.

Z is —O—, —S—, direct bond, —CO—, —SO ₂ —, —SO—, — (CH ₂ ) ₁ — (wherein 1 is an integer of 1 to 10), — or C ( And at least one structure selected from the group consisting of CH ₃ ) ₂ —.

R ¹¹ is at least one selected from the group consisting of a direct bond, —O (CH ₂ ) _p —, —O (CF ₂ ) _p —, — (CH ₂ ) _p —, — or (CF ₂ ) _p —. The structure of a seed is shown (p shows the integer of 1-12).

R ¹² and R ¹³ each independently represent at least one structure selected from the group consisting of a hydrogen atom, an alkali metal atom, or an aliphatic hydrocarbon group. However, at least one of all R ¹² and R ¹³ included in the above formula is a hydrogen atom.

x ¹ is 0-4 integer. x ² is an integer of 1 to 5. a is an integer of 0 to 1. b shows the integer of 0-3.
The structural unit having a sulfonic acid group is preferably composed of a repeating unit represented by the following formula (12).

上記式中、Ａｒ¹¹、Ａｒ¹²、Ａｒ¹³は、各々独立に、フッ素原子で置換されていてもよい、ベンゼン環、縮合芳香環（ナフタレン環など）、含窒素複素環からなる群より選ばれた少なくとも１種の構造を示す。

In the above formula, Ar ¹¹ , Ar ¹² , and Ar ¹³ are each independently selected from the group consisting of a benzene ring, a condensed aromatic ring (such as a naphthalene ring), and a nitrogen-containing heterocyclic ring that may be substituted with a fluorine atom. And at least one structure.

Y is —CO—, —SO ₂ —, —SO—, — (CF ₂ ) _u — (u is an integer of 1 to 10), —C (CF ₃ ) ₂ —, or a group consisting of direct bonds. It shows at least one selected structure.
Z is —O—, —S—, direct bond, —CO—, —SO ₂ —, —SO—, — (CH ₂ ) ₁ — (l is an integer of 1 to 10), —C (CH ₃ ) Shows at least one structure selected from the group consisting of _2- .

R ¹¹ is at least one selected from the group consisting of a direct bond, —O (CH ₂ ) _p —, —O (CF ₂ ) _p —, — (CH ₂ ) _p —, and — (CF ₂ ) _p —. (P represents an integer of 1 to 12).

R ¹² and R ¹³ each independently represent at least one structure selected from the group consisting of a hydrogen atom, an alkali metal atom, and an aliphatic hydrocarbon group. However, at least one of all R ¹² and R ¹³ included in the above formula is a hydrogen atom.

x ¹ is an integer of 0 to 4, x ² is an integer of 1 to 5, a is an integer of 0 to 1, and b1 and b2 are integers of 0 to 3.
The repeating unit represented by the above formula (12) or (12a) preferably has a structure represented by the following formula (13).

式（１３）において、Ｙ、Ｚ、Ａｒ、ｃ、ｄ、ｋについては前記式（１１）と同一である。なお、各構成単位の端部における単線のうち、一方に置換基が表示されていないものは隣り合う構成単位との接続を意味する。
なお、前記式（８）および（１１）のＹおよびＺは、同一のものであって異なるものであってもよい。

In Formula (13), Y, Z, Ar, c, d, and k are the same as those in Formula (11). In addition, among the single lines at the end of each structural unit, those in which no substituent is displayed on one side mean connection with adjacent structural units.
In the above formulas (8) and (11), Y and Z may be the same and different.

Sulfonated polyarylene copolymer The sulfonated polyarylene copolymer of the present invention comprises a structural unit having a sulfonic acid group represented by the above formula (10) and a condensed fragrance represented by the above formula (1). And a polymer represented by the following formula (14) or the following formula (14a). Of the single wires at the end of each structural unit, one not having a substituent displayed on one side means connection with an adjacent structural unit.

上記式（１４）中、Ａｒ¹¹、Ａｒ¹²、Ａｒ¹³、Ｙ、Ｒ¹¹、Ｒ¹²、ｘ¹、ｘ²、ａおよびｂ１，ｂ２は、式（１２）と同様である。Ａｒ²¹、Ａｒ²²、Ａｒ²³、Ａｒ²⁴、Ａ、Ｂ、Ｄ、ｒ、ｓおよびｔは、式（１）と同様である。ｘ、ｙは、ｘ＋ｙ＝１００モル％とした場合のモル比を示す。

In the above formula ^{(14), Ar 11, Ar} 12, Ar 13, Y, R 11, R 12, x 1, x 2, a and b1, b2 is the same as equation (12). Ar ²¹ , Ar ²² , Ar ²³ , Ar ²⁴ , A, B, D, r, s and t are the same as in formula (1). x and y represent molar ratios when x + y = 100 mol%.

上記式中、Ａｒ¹¹、Ａｒ¹²、Ａｒ¹³、Ｙ、Ｚ、Ｒ¹¹、Ｒ¹²、Ｒ¹³、ｘ¹、ｘ²、aおよびbは、式（１２ａ）と同様である。Ａｒ²¹、Ａｒ²²、Ａｒ²³、Ａｒ²⁴、Ａ、Ｂ、Ｄ、ｒ、ｓおよびｔは、式（１）と同様である。ｘ、ｙは、ｘ＋ｙ＝１００モル％とした場合のモル比を示す。

In the above formula, Ar ¹¹ , Ar ¹² , Ar ¹³ , Y, Z, R ¹¹ , R ¹² , R ¹³ , x ¹ , x ² , a and b are the same as those in the formula (12a). ^{Ar 21, Ar 22, Ar 23} , Ar 24, A, B, D, r, s and t are the same as equation (1). x and y represent molar ratios when x + y = 100 mol%.

When the nitrogen-containing aromatic side chain is included, the structural unit represented by the formula (7) is included in the formula (14) or (14a).
The sulfonated polyarylene represented by the above formula (14) preferably has a structure represented by the following formula (15).

式（１５）において、Ａ、Ｂ、Ｄ、Ｙ、Ｚ、Ｐｈ、Ａｒ、ｃ、ｄ、ｋ、ｌ、ｍ、ｎ、ｐ、ｑ、ｔ、およびＲ₁〜Ｒ₂₀は、それぞれ上記式（２）、（１３）中のＡ、Ｂ、Ｄ、Ｙ、Ｚ、Ｐｈ、Ａｒ、ａ、ｂ、ｃ、ｄ、ｋ、ｌ、ｍ、ｎ、ｐ、ｑ、ｓ、ｔ、およびＲ₁〜Ｒ₂₀と同義である。ｘ、ｙはｘ＋ｙ＝１００モル％とした場合のモル比を示す。各構成単位の端部における単線のうち、一方に置換基が表示されていないものは隣り合う構成単位との接続を意味する。

In the formula (15), A, B, D, Y, Z, Ph, Ar, c, d, k, l, m, n, p, q, t, and R _{1 to} R ₂₀ are each represented by the above formula ( 2), A, B, D, Y, Z, Ph, Ar, a, b, c, d, k, l, m, n, p, q, s, t, and R ₁ in (13) It has the same meaning as R _20. x and y represent molar ratios when x + y = 100 mol%. Of the single wires at the end of each structural unit, one not having a substituent displayed on one side means connection with an adjacent structural unit.

In the formula (15), x is 0.5 to 99.9 mol%, preferably 10 to 99.5 mol%, and y is 0.1 to 99.5 mol%, preferably 0.5 to It is 89.5 mol%.
The ion exchange capacity of the polymer according to the present invention is usually 0.3 to 5 meq / g, preferably 0.5 to 3 meq / g, and more preferably 0.8 to 2.8 meq / g. When the ion exchange capacity is 0.3 meq / g or more, a proton conductivity is high and a power generation performance is high. On the other hand, if it is 5 meq / g or less, the fall of water resistance can be suppressed and a thing with high water resistance will be obtained.

  The ion exchange capacity can be adjusted by changing the type, the use ratio, and the combination of the condensed aromatic ring structural unit, the structural unit having a nitrogen-containing heterocyclic group, and the structural unit having a sulfonic acid group. Therefore, it can be adjusted by changing the charge amount ratio and type of the precursor (monomer / oligomer) that induces each structural unit during polymerization.

  In general, when the number of structural units having a sulfonic acid group increases, the ion exchange capacity increases and the proton conductivity increases, but the water resistance decreases. On the other hand, when the number of structural units having a sulfonic acid group decreases, the ion exchange capacity decreases and the water resistance increases, but the proton conductivity decreases.

  The polymer of the above formula (15) may contain a structural unit represented by the formula (7). When such a structural unit is contained, the stability of the sulfonic acid group under high temperature conditions is improved. As a result, the heat resistance is improved. In addition, since the nitrogen atom of a nitrogen-containing heterocyclic aromatic compound has basicity, it forms ionic interaction with a sulfonic acid group. This enhances the stability of the sulfonic acid group and suppresses the elimination of the sulfonic acid group under high temperature conditions. Similarly, the cross-linking reaction between polymer molecules derived from sulfonic acid groups can be suppressed under high temperature conditions. The nitrogen-containing heterocyclic aromatic compound is a compound having an adequately strong basicity that can exhibit these effects without impairing proton conductivity. The molar ratio of the structural unit represented by the formula (9) to the structural unit represented by the formula (13), that is, the structural unit of x is 0.001 to 50, preferably 0.1 to 30. More preferably, it is 1-25.

  When the condensed aromatic ring structural unit is contained, it becomes easy to adjust the molecular weight and the content of each structural unit, and a thermally and chemically stable polymer can be obtained. By including the condensed aromatic ring structural unit, a hydrophobic portion can be imparted to the polymer, and since the condensed aromatic ring is included, methanol resistance can be imparted to the polymer.

The molecular weight of the polymer of the present invention is 10,000 to 1,000,000, preferably 20,000 to 800,000 in terms of polystyrene-equivalent weight average molecular weight by gel permeation chromatography (GPC).
Such polymers are disclosed in Japanese Patent Application Laid-Open Nos. 2008-163158, 2005-126391, 2004-346164, 2005-60484, and 2005-82757 by the present applicant. It can be prepared by the method described in the publication.
A specific method for producing polyarylene will be described below.

<Method for producing polymer>
For the production of the polyarylene having a sulfonic acid group used in the present invention, for example, the following three methods A, B, and C can be used.

(Method A)
Similarly to the method described in JP-A-2004-137444, the monomer (A) represented by the following formula (16) and, if necessary, the monomer (C) represented by the following formula (24) and the following formula ( The monomer (B) represented by 18) is copolymerized to produce a polymer having a sulfonic acid ester group, and the sulfonic acid ester group is deesterified to convert the sulfonic acid ester group into a sulfonic acid group. Can be synthesized.

Monomer (A)
The monomer (A) is a monomer having a sulfonic acid group, and is represented by the following formula (16).

式（１６）で、Ａｒ¹¹、Ａｒ¹²、Ａｒ¹³は同一でも、異なっていてもよく、フッ素原子で置換されていてもよい、ベンゼン環、縮合芳香環、含窒素複素環からなる群より選ばれた少なくとも１種の構造を示す。

In the formula (16), Ar ¹¹ , Ar ¹² and Ar ¹³ may be the same or different, and may be substituted with a fluorine atom, selected from the group consisting of a benzene ring, a condensed aromatic ring and a nitrogen-containing heterocycle. At least one structure is shown.

  X represents at least one structure selected from the group consisting of chlorine, bromine, iodine, methanesulfonyl group, trifluoromethanesulfonyl group, benzenesulfonyl group, and toluenesulfonyl group.

Y represents —CO—, —SO ₂ —, —SO—, — (CF ₂ ) ₁ — (l is an integer of 1 to 10), —C (CF ₃ ) ₂ —, or a group consisting of direct bonds. It shows at least one selected structure.
Z is —O—, —S—, direct bond, —CO—, —SO ₂ —, —SO—, — (CH ₂ ) ₁ — (l is an integer of 1 to 10), —C (CH ₃ ) Shows at least one structure selected from the group consisting of _2- .

R ¹¹ is at least one selected from the group consisting of a direct bond, —O (CH ₂ ) _p —, —O (CF ₂ ) _p —, — (CH ₂ ) _p —, and — (CF ₂ ) _p —. (P represents an integer of 1 to 12).

R ¹² and R ^{13 each} represents at least one structure selected from the group consisting of a hydrogen atom, an alkali metal atom, and an aliphatic hydrocarbon group. However, at least one of all R ¹² and R ¹³ included in the above formula is a hydrogen atom.

x ¹ is an integer of 0 to 4, x ² is an integer of 1 to 5, a is an integer of 0 to 1, and b is an integer of 0 to 3.
The monomer represented by the above formula (16) preferably has a structure represented by the following formula (17).

式（１７）中、Ｘは塩素原子、臭素原子および−ＯＳＯ₂Ｒｂ（ここで、Ｒｂはアルキル基、フッ素置換アルキル基またはアリール基を示す）から選ばれる原子または基を示す。

In the formula (17), X represents an atom or group selected from a chlorine atom, a bromine atom and —OSO ₂ Rb (where Rb represents an alkyl group, a fluorine-substituted alkyl group or an aryl group).

Y, Z, and k are the same as those in formula (16), and R represents an alkyl group having 4 to 12 carbon atoms. c represents an integer of 0 to 10, and d represents an integer of 0 to 10.
Ar is an aromatic group having a substituent represented by —SO ₃ R or —O (CH ₂ ) _h SO ₃ R or —O (CF ₂ ) _h SO ₃ R (h represents an integer of 1 to 12). Indicates.

  Specific examples of the compound represented by the formula (17) include compounds represented by the following formulas, JP-A Nos. 2004-137444, 2004-345997, and 2004-346163. The sulfonic acid esters that have been described can be mentioned.

式（１７）で表される化合物において、スルホン酸エステル構造は、通常、芳香族環のメタ位に結合している。

In the compound represented by the formula (17), the sulfonate structure is usually bonded to the meta position of the aromatic ring.

Monomer (B)
The monomer (B) is a monomer having a condensed aromatic ring structure, and is represented by the following formula (18).

（式（１８）中、Ａｒ²¹、Ａｒ²²、Ａｒ²³、Ａｒ²⁴は、ベンゼン環、ナフタレン環、含窒素複素環からなる群より選ばれた少なくとも１種の構造を示す。ただし、Ａｒ²¹、Ａｒ²²、Ａｒ²³、Ａｒ²⁴は、その水素原子の一部又はまたはすべてが、フッ素原子、ニトロ基、ニトリル基、又はまたは水素原子の一部またはすべてがフッ素置換されていてもよいアルキル基、アリル基若しくはアリール基からなる群より選ばれた少なくとも１種の原子または基で置換されていてもよい。

(In the formula (18), Ar ²¹ , Ar ²² , Ar ²³ and Ar ²⁴ represent at least one structure selected from the group consisting of a benzene ring, a naphthalene ring and a nitrogen-containing heterocyclic ring, provided that Ar ²¹ , Ar ²² , Ar ²³ , Ar ²⁴ are a part of or all of the hydrogen atoms, a fluorine atom, a nitro group, a nitrile group, or an alkyl group in which part or all of the hydrogen atoms may be fluorine-substituted, It may be substituted with at least one atom or group selected from the group consisting of an allyl group or an aryl group.

  X represents at least one structure selected from the group consisting of chlorine, bromine, iodine, methanesulfonyl group, trifluoromethanesulfonyl group, benzenesulfonyl group, and toluenesulfonyl group.

A and D are independently a direct bond, or —CO—, —SO ₂ —, —SO—, — (CF ₂ ) ₁ — (l is an integer of 1 to 10), — (CH ₂ ) ₁ — ( l is an integer of 1 to _{10), - CR '2 - (} R' represents an aliphatic hydrocarbon group, aromatic hydrocarbon group or a halogenated hydrocarbon group), cyclohexylidene group, a fluorenylidene group, - At least one structure selected from the group consisting of O- and -S-, B is independently an oxygen atom or a sulfur atom, s and t each independently represent an integer of 0 to 4, r represents 0 or an integer of 1 or more. )
The monomer represented by the above formula (18) preferably has a structure represented by the following formula (19).

式（１９）中、Ａ、Ｂ、Ｄ、Ｐｈ、Ｒ₁〜Ｒ₂₀、ｌ、ｍ、ｎ、ｐ、ｑ、ｔは式（２）と同様である。

In the formula (19), A, B, D, Ph, R _{1 to} R ₂₀ , l, m, n, p, q, and t are the same as those in the formula (2).

X represents a halogen atom excluding fluorine, an atom or group selected from —SO ₂ CH ₃ and —SO ₂ CF ₃ ;
Ph is preferably a group selected from a naphthalene group, an anthracene group, a tetracene group, and a pentacene group.

  The compound represented by the formula (19) is more preferably a compound represented by the following formula (20).

［式（２０）中、Ａ、Ｄ、Ｐｈ、Ｒ₁〜Ｒ₂₀、ｌ、ｍ、ｑ、ｔ、ｎ、ｐは式（２）と同様である。Ｘは、フッ素を除くハロゲン原子から選ばれる原子を示す。

[In formula (20), A, D, Ph, R _{1 to} R ₂₀ , l, m, q, t, n, and p are the same as in formula (2). X represents an atom selected from halogen atoms excluding fluorine.

  Furthermore, as such a compound, what is represented by following formula (21) is preferable.

式（２１）中、Ｘはフッ素を除くハロゲン原子から選ばれる原子を示す。Ｄ、Ｐ、Ｐｈ、ｑ、ｍ、ｔ、ｎ、ｐは式（１９）と同様である。ｐが０．０１〜１の範囲にあることが好ましい。

In formula (21), X represents an atom selected from halogen atoms excluding fluorine. D, P, Ph, q, m, t, n, and p are the same as in equation (19). It is preferable that p is in the range of 0.01-1.

The compound represented by the above formula (18) can be synthesized, for example, by the following reaction.
First, bisphenols represented by the following formula (22-1) and, if necessary, bisphenols represented by the formula (22-2) are used as alkali metal salts.

上記式（２２−１）中、Ｒ⁹〜Ｒ²⁰およびＤは、式（１８）と同様である。上記式（２２−２）中、Ｐｈは、式（１９）と同様である。

In said formula (22-1), R < ⁹ > -R < ²⁰ > and D are the same as that of Formula (18). In the above formula (22-2), Ph is the same as in formula (19).

  At this time, after dissolving in a polar solvent having a high dielectric constant such as N-methyl-2-pyrrolidone, N, N-dimethylacetamide, sulfolane, diphenylsulfone, dimethylsulfoxide, an alkali metal such as lithium, sodium, potassium, Add alkali metal hydride, alkali metal hydroxide, alkali metal carbonate, etc. The alkali metal is reacted in excess with respect to the hydroxyl group of phenol, and is usually used in an amount of 1.1 to 2 times equivalent, preferably 1.2 to 1.5 times equivalent. At this time, it is preferable to promote the progress of the reaction by coexisting a solvent azeotropic with water such as benzene, toluene, xylene, chlorobenzene, and anisole.

  Next, the alkali metal salt of the bisphenol is reacted with a dihalide represented by the following formula (23).

式（２３）中、Ｈａｌはハロゲン原子を示し、特にフッ素原子または塩素原子が好ましい。

In the formula (23), Hal represents a halogen atom, and a fluorine atom or a chlorine atom is particularly preferable.

  Examples of the bisphenols represented by the formula (22-1) include 1,3-bis [1-methyl-1- (4-hydroxyphenyl) ethyl] benzene (Bis-M), 1,4-bis [1 -Methyl-1- (4-hydroxyphenyl) ethyl] benzene, 1,3- (4-hydroxybenzoylbenzene), 1,4- (4-hydroxybenzoylbenzene), 1,3-bis (4-hydroxyphenoxy) Benzene, 1,4-bis (4-hydroxyphenoxy) benzene, 1,4-bis (4-hydroxyphenyl) benzene, 1,3-bis (4-hydroxyphenyl) benzene, 4,4′-isopropylidenebiphenol ( Bis-A), 2,2-bis (4-hydroxyphenyl) -1,1,1,3,3,3-hexafluoropropane (Bis-AF), 4, 4'-bishydroxybenzophenone (4,4'-DHBP), 4,4'-bishydroxydiphenyl sulfone (4,4'-DHDS), 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxybiphenyl (4 , 4′-DHBP), bis (4-hydroxyphenyl) methane, resorcinol (RES), hydroquinone (HQ), 9,9-bis (4-hydroxyphenyl) fluorene (BPFL), 9,9-bis (4- Hydroxy-3-methylphenyl) fluorene (BCFL), 4,4′-isopropylidenebis (2-phenylphenol), 4,4′-cyclohexylidenebis (2-cyclohexylphenol) and the like. Among them, 1,3-bis [1-methyl-1- (4-hydroxyphenyl) ethyl] benzene (Bis-M), 1,4-bis [1-methyl-1- (4-hydroxyphenyl) ethyl] benzene 2,2-bis (4-hydroxyphenyl) -1,1,1,3,3,3-hexafluoropropane (Bis-AF), resorcinol (RES), 9,9-bis (4-hydroxyphenyl) Fluorene (BPFL) is preferred. These bisphenols may be used alone or in combination of two or more.

  Examples of the bisphenols represented by the formula (22-2) include 1,5-dihydroxynaphthalene (1,5-NAP), 1,6-dihydroxynaphthalene (1,6-NAP), 1,7- Dihydroxynaphthalene (1,7-NAP), 2,6-dihydroxynaphthalene (2,6-NAP), 2,7-dihydroxynaphthalene (2,7-NAP), 2,3-dihydroxynaphthalene (2,3-NAP) ) And the like. Among them, 2,7-dihydroxynaphthalene (2,7-NAP), 1,5-dihydroxynaphthalene (1,5-NAP), 1,6-dihydroxynaphthalene (1,6-NAP), 1,7-dihydroxy Naphthalene (1,7-NAP) is preferred. These bisphenols may be used alone or in combination of two or more.

  Examples of the dihalide represented by the formula (23) include 4,4′-dichlorobenzophenone (4,4′-DCBP), 4,4′-difluorobenzophenone (4,4′-DFBP), 4-chloro- 4′-fluorobenzophenone, 2-chloro-4′-fluorobenzophenone, 4,4′-dichlorodiphenyl sulfone (4,4′-DCDS), 4,4′-difluorodiphenyl sulfone (4,4′-DFDS), 2,6-dinitrobenzonitrile, 2,5-dinitrobenzonitrile, 2,4-dinitrobenzonitrile, 2,6-dichlorobenzonitrile (2,6-DCBN), 2,5-dichlorobenzonitrile (2,5 -DCBN), 2,4-dichlorobenzonitrile (2,4-DBN), 2,6-difluorobenzonitrile (2,6-DFBN), 2,5 -Difluorobenzonitrile (2,5-DFBN), 2,4-difluorobenzonitrile (2,4-DFBN) and the like. These bisphenols may be used alone or in combination of two or more.

  The dihalide is used in an amount of 1.0001 to 1 mol, preferably 1.001 to 2 mol based on bisphenol. Further, after the completion of the reaction, for example, an excess of a dichloro compound may be further reacted so that both ends are chlorine atoms. When a difluoro compound or a dinitro compound is used, it is necessary to devise a method of adding a dichloro compound in the latter half of the reaction so that both ends are chlorine atoms.

In these reactions, the reaction temperature is 60 ° C to 300 ° C, preferably 80 ° C to 250 ° C, and the reaction time is 15 minutes to 100 hours, preferably 1 hour to 24 hours.
The obtained compound is an oligomer or a polymer, and these can be purified by a general purification method of a polymer, for example, a dissolution-precipitation operation. The molecular weight is adjusted by the reaction molar ratio of excess aromatic dichloride and bisphenol. Since the aromatic dichloride is in excess, the molecular end of the resulting compound is an aromatic chloride.

  Specific examples of the aromatic compound synthesized by the above method include the following.

上記式中、ｎ、ｐおよびｑは、式（１９）と同様である。

In the above formula, n, p and q are the same as in formula (19).

  The following is a specific example of an aromatic compound in which n = 0 and composed of two or more types of compounds of the formula (22-2).

（上記式中、ｐ₁、ｐ₂は各構成単位の組成比を示し、ｐ₁は０から１の値のうち０以外の値をとり、ｐ₁＋ｐ₂＝１である。）
以下は、ｎ＝０であり、１種類の式（２２−２）の化合物を用いて構成される芳香族化合物の具体例を示す。

(In the above formulas, p ₁ and p ₂ represent the composition ratio of each structural unit, and p ₁ takes a value other than 0 from 0 to 1, and p ₁ + p ₂ = 1.)
The following is a specific example of an aromatic compound in which n = 0 and one type of compound of formula (22-2) is used.

上記式中、ｐおよびｑは、式（１９）と同様である。

In the above formula, p and q are the same as in formula (19).

  Among these aromatic compounds, compounds of (22-2) include 2,7-dihydroxynaphthalene (2,7-NAP), 1,5-dihydroxynaphthalene (1,5-NAP), 1,6- As compounds of dihydroxynaphthalene (1,6-NAP) and (1-1), 1,3-bis [1-methyl-1- (4-hydroxyphenyl) ethyl] benzene (Bis-M), 1,4- Bis [1-methyl-1- (4-hydroxyphenyl) ethyl] benzene, 2,2-bis (4-hydroxyphenyl) -1,1,1,3,3,3-hexafluoropropane (Bis-AF) The compound synthesized from resorcinol (RES) is preferred.

  The glass transition temperature of the polymer can be adjusted by changing the ratio of n and p in the above formula. Among these, a compound having a value of p = 0 to 1 is preferable from the viewpoint of polymer processability.

Monomer (C)
The monomer (C) is a monomer having a nitrogen-containing heterocyclic structure and is represented by the following formula (24).

Ｘは塩素原子または臭素原子、−ＯＳＯ₂Ｒｂ(ここで、Ｒｂはアルキル基、フッ素置換アルキル基またはアリール基を示す)から選ばれる原子または基を示す。

X represents an atom or group selected from a chlorine atom or a bromine atom, and -OSO ₂ Rb (wherein Rb represents an alkyl group, a fluorine-substituted alkyl group or an aryl group).

W, V, Ar ⁹ , Ar ¹⁰ , R ₂₁ , e and f are the same as in the above formula (7).
Specifically, it is represented by the following formula (25).

Ｘ、Ｗ、Ｖ、Ｒ₂₁、eおよびfは前記式(２４)と同様である。

X, W, V, R ₂₁ , e and f are the same as in the above formula (24).

  Specific examples of the monomer (C) include the following compounds.

さらに、塩素原子が臭素原子に置き換わった化合物、塩素原子や臭素原子の結合位置の異なる異性体を挙げることができる。また−ＣＯ−結合が、−ＳＯ₂−結合に置き換わった化合物を挙げることができる。これらの化合物は、単独で用いてもよく、２種類以上を併用してもよい。

Furthermore, compounds in which a chlorine atom is replaced with a bromine atom, and isomers having different bonding positions of chlorine and bromine atoms can be exemplified. In addition, a compound in which a —CO— bond is replaced with a —SO ₂ — bond can be exemplified. These compounds may be used alone or in combination of two or more.

  Examples of the method for synthesizing the monomer (C) include a method in which a compound represented by the following formula (26) and a nitrogen-containing heterocyclic compound are subjected to a nucleophilic substitution reaction.

式中、Ｘ、Ｗ、ｅおよびｆは、式(２４)および（２５）で示した定義と同一である。
Ｘ'はハロゲン原子を示し、具体的にはフッ素原子または塩素原子であることが好ましく、フッ素原子がより好ましい。

In the formula, X, W, e and f are the same as the definitions shown in the formulas (24) and (25).
X ′ represents a halogen atom, specifically, preferably a fluorine atom or a chlorine atom, more preferably a fluorine atom.

  Specific examples of the compound represented by the formula (26) include 2,4-dichloro-4′-fluorobenzophenone, 2,5-dichloro-4′-fluorobenzophenone, and 2,6-dichloro-4′-fluorobenzophenone. 2,4-dichloro-2′-fluorobenzophenone, 2,5-dichloro-2′-fluorobenzophenone, 2,6-dichloro-2′-fluorobenzophenone, 2,4-dichlorophenyl-4′-fluorophenylsulfone, 2,5-dichlorophenyl-4'-fluorophenylsulfone, 2,6-dichlorophenyl-4'-fluorophenylsulfone, 2,4-dichlorophenyl-2'-fluorophenylsulfone, 2,4-dichlorophenyl-2'-fluorophenyl Sulfone, 2,4-dichlorophenyl-2'-fluorophenylsulfone. Of these compounds, 2,5-dichloro-4'-fluorobenzophenone is preferred.

The nitrogen-containing heterocyclic compound has active hydrogen, and this active hydrogen is subjected to a substitution reaction with the group represented by X ′ of the compound represented by the formula (26).
Examples of nitrogen-containing heterocyclic compounds having active hydrogen include pyrrole, thiazole, isothiazole, oxazole, isoxazole, pyridine, imidazole, imidazoline, pyrazole, 1,3,5-triazine, pyrimidine, pyritazine, pyrazine, indole, quinoline, Isoquinoline, bromine, benzimidazole, benzoxazole, benzthiazole, tetrazole, tetrazine, triazole, carbazole, acridine, quinoxaline, quinazoline, 2-hydroxypyridine, 3-hydroxypyridine, 4-hydroxypyridine, 3-hydroxyquinoline, 8-hydroxy Quinoline, 2-hydroxypyrimidine, 2-mercaptopyridine, 3-mercaptopyridine, 4-mercaptopyridine, 2-mercaptopyrimidine, 2-me , And the like mercapto benzthiazole.

Of these compounds, pyrrole, imidazole, indole, carbazole, benzoxazole, and benzimidazole are preferable.
The reaction between the compound represented by formula (26) and the nitrogen-containing heterocyclic compound having active hydrogen is preferably carried out in an organic solvent. A polar solvent such as N-methyl-2-pyrrolidone, N, N-dimethylacetamide, sulfolane, diphenylsulfone, dimethylsulfoxide is used. In order to accelerate the reaction, alkali metal, alkali metal hydride, alkali metal hydroxide, alkali metal carbonate, or the like is used. The ratio between the compound represented by the formula (26) and the nitrogen-containing heterocyclic compound having active hydrogen is such that an equimolar amount or nitrogen-containing heterocyclic compound having active hydrogen is added in excess. Specifically, the nitrogen-containing heterocyclic compound having active hydrogen is preferably used in an amount of 1 to 3 times mol, particularly 1 to 1.5 times mol of the compound represented by the formula (26).

The reaction temperature is 0 ° C to 300 ° C, preferably 10 ° C to 200 ° C. The reaction time is 15 minutes to 100 hours, preferably 1 hour to 24 hours.
The product is preferably used after being purified by a method such as recrystallization.

Polymerization In order to obtain the polymer of the present invention, the above various monomers are first copolymerized to obtain a precursor.
This copolymerization is carried out in the presence of a catalyst, and the catalyst used in this case is a catalyst system containing a transition metal compound. This catalyst system is (1) a transition metal salt and a ligand. A compound (hereinafter referred to as “ligand component”) or a transition metal complex coordinated with a ligand (including a copper salt) and (2) a reducing agent as essential components, and further increase the polymerization rate. Therefore, salts other than transition metal salts may be added.

  As specific examples of these catalyst components, the use ratio of each component, reaction solvent, concentration, temperature, time, and other polymerization conditions, the compounds and conditions described in JP-A No. 2001-342241 can be employed.

  For example, as the transition metal salt, nickel chloride, nickel bromide and the like are preferably used, and as the compound serving as a ligand, triphenylphosphine, tri-o-tolylphosphine, tri-m-tolylphosphine, Tri-p-tolylphosphine, tributylphosphine, tri-tert-butylphosphine, trioctylphosphine, 2,2′-bipyridine and the like are preferably used. Furthermore, nickel chloride bis (triphenylphosphine) and nickel chloride (2,2′bipyridine) are preferably used as the transition metal (salt) in which the ligand is coordinated in advance. Examples of the reducing agent include iron, zinc, manganese, aluminum, magnesium, sodium, and calcium, and zinc, magnesium, and manganese are preferable. As the “salt”, sodium bromide, sodium iodide, potassium bromide, tetraethylammonium bromide, and tetraethylammonium iodide are preferable. A polymerization solvent may be used for the reaction, and specifically, tetrahydrofuran, N, N-dimethylformamide, N, N-dimethylacetamide, 1-methyl-2-pyrrolidone and the like are preferably used.

  The proportion of each component used in the catalyst system is usually from 0.0001 to 10 mol, preferably from 0.0001 to 10 mol, based on 1 mol of the total amount of monomers of the transition metal salt or the transition metal (salt) coordinated with the ligand. 01-0.5 mol. If it exists in this range, it can polymerize with high catalyst activity and high molecular weight. When a salt other than a transition metal salt is used in the catalyst system, the amount used is usually 0.001 to 100 mol, preferably 0.01 to 1 mol, per 1 mol of the total amount of monomers. Within such a range, the effect of increasing the polymerization rate is sufficient. The total concentration of the monomers in the polymerization solvent is usually 1 to 90% by mass, preferably 5 to 40% by mass. Moreover, the polymerization temperature at the time of superposing | polymerizing the polymer of this invention is 0-200 degreeC normally, Preferably it is 50-100 degreeC. The polymerization time is usually 0.5 to 100 hours, preferably 1 to 40 hours.

Next, the obtained polymer is hydrolyzed to convert the sulfonic acid ester group (—SO ₃ R) in the structural unit into a sulfonic acid group (—SO ₃ H).
Hydrolysis includes (1) a method in which the polymer having a sulfonic acid ester group is added to an excess amount of water or alcohol containing a small amount of hydrochloric acid, and the mixture is stirred for 5 minutes or longer. (2) the sulfone is added in trifluoroacetic acid. a method of reacting about 5 to 10 hours at a temperature of about 80 to 120 ° C. the polymer having an ester group, (3) sulfonic acid ester group in the polymer (-SO ₃ R) 1 to 3 relative to 1 mole of After the polymer having a sulfonic acid ester group is reacted at a temperature of about 80 to 150 ° C. for about 3 to 10 hours in a solution containing double moles of lithium bromide, such as N-methylpyrrolidone, hydrochloric acid is added. It can be performed by the method of doing.

(B) Method In addition to the above method, for example, as in the method described in JP-A-2001-342241, it has a skeleton represented by the above formula (16), and has a sulfonic acid group and a sulfonic acid ester group. The monomer (18) and the monomer (24) can be copolymerized, and the polymer can be synthesized by sulfonation using a sulfonating agent (this is Method B). Called).

  As specific examples of the monomer having no sulfonic acid group or sulfonic acid ester group that can be a structural unit represented by the above formula (10) that can be used in Method B, JP-A-2001-342241, Mention may be made of the dihalides described in Kaikai 2002-293889.

(C) method also in addition to the above method, in formula (16), an aromatic group having a substituent Ar is represented by _{-O (CH 2) h SO 3} H or _{-O (CF 2) h SO 3} H In this case, for example, as in the method described in JP-A-2005-606254, the monomer represented by the above formula (16), the monomer or oligomer represented by the above formula (18), and the above It can also be synthesized by copolymerizing the monomer represented by the formula (24) and then introducing an alkylsulfonic acid or a fluorine-substituted alkylsulfonic acid (this is called C method).

  Specific examples of the monomer represented by the above formula (16) that can be used in (Method C) include dihalides described in JP-A-2005-36125. Specifically, 2,5-dichloro-4′-hydroxybenzophenone, 2,4-dichloro-4′-hydroxybenzophenone, 2,6-dichloro-4′-hydroxybenzophenone, 2,5-dichloro-2 ′, Examples thereof include 4′-dihydroxybenzophenone and 2,4-dichloro-2 ′, 4′-dihydroxybenzophenone. Moreover, the compound which protected the hydroxyl group of these compounds by the tetrahydropyranyl group etc. can be mention | raise | lifted. Further, those in which a hydroxyl group is replaced with a thiol group and those in which a chlorine atom is replaced with a bromine atom or an iodine atom can also be mentioned.

  In (Method C), an alkylsulfonic acid group is introduced into a polymer (which does not have a sulfonic acid group) by the method described in JP-A-2005-60625. For example, it can be introduced by reacting the hydroxyl group of the precursor polymer with propane sultone, butane sultone, or the like.

[B] Fluorine-containing polymer In the present invention, a solvent-soluble fluorine-containing polymer is used. Such a fluorine-containing polymer is characterized by excellent heat resistance, chemical resistance, mechanical properties, wear resistance, and the like, and low gas permeability.

  Furthermore, by using a solvent-soluble fluorine-containing polymer, it has the property of facilitating the production of a proton conducting membrane having a continuous phase made of a polyarylene copolymer and a dispersed phase made of a fluorine-containing polymer. Yes. Such a solvent-soluble fluorine-containing polymer is not particularly limited, and examples thereof include vinylidene fluoride homo (co) polymers, fluoroolefin / hydrocarbon olefin copolymers, and fluoroacrylate copolymers. , Fluoroepoxy compounds and the like can be used.

  Among these, from the viewpoint of combining with the polyarylene-based copolymer, those composed of (1) a vinylidene fluoride homo (co) polymer and (2) a fluoroolefin / hydrocarbon olefin copolymer are preferable.

(1) Polyvinylidene fluoride homo (co) polymer The vinylidene fluoride homo (co) polymer is not particularly limited, but for example, polyvinylidene fluoride, vinylidene fluoride and hexafluoropropylene Examples thereof include a copolymer, a copolymer of vinylidene fluoride and tetrafluoroethylene, and a terpolymer of vinylidene fluoride, hexafluoropropylene and tetrafluoroethylene. Here, as the at least one other monomer copolymerizable with vinylidene fluoride, for example, tetrafluoroethylene, chlorotrifluoroethylene, trifluoroethylene, hexafluoropropylene, trifluoropropylene, tetrafluoropropylene, Examples thereof include fluorine-containing monomers such as pentafluoropropylene, trifluorobutene, tetrafluoroisobutene, perfluoro (alkyl vinyl ether) and vinyl fluoride, and non-fluorine monomers such as ethylene, propylene and alkyl vinyl ether. These can be used alone or in any combination. Such polyvinylidene fluoride homo (co) polymers are particularly excellent in high-temperature mechanical properties such as high impact strength and high heat distortion temperature over a wide temperature range, and almost all processing methods can be applied. Since it has characteristics, it is preferable when used in an atmosphere other than a strong oxidizing atmosphere.

(2) Fluoroolefin / hydrocarbon olefin copolymer The fluoroolefin used in the present invention is vinyl fluoride, vinylidene fluoride, chlorotrifluoroethylene, tetrafluoroethylene, 1,1-dichloro-2,2-difluoroethylene. , 1-chloro-1,2-difluoroethylene, hexafluoropropylene, 1,1,3,3,3-pentafluoropropylene, 2,3,3,3-tetrafluoropropylene, 3,3,3-trifluoropropylene , 1,1,2-trifluoropropylene and the like, and preferably one or more of tetrafluoroethylene, chlorotrifluoroethylene, and hexafluoropropylene.

  Typical examples of the hydrocarbon-based olefin copolymer copolymerizable with the fluoroolefin include carboxylic acid vinyl esters, hydroxyalkyl vinyl ethers or alkyl vinyl ethers. First, specific examples of the carboxylic acid esters include acetic acid. Linear or branched aliphatic carboxylic acid vinyl esters such as vinyl, vinyl propionate, vinyl butyrate, vinyl bivalate, vinyl caproate, vinyl caprylate, vinyl caprate, vinyl versatate, vinyl laurate or vinyl stearate A vinyl ester of an alicyclic carboxylic acid such as cyclohexanecarboxylic acid vinyl ester; or an aromatic vinyl ester such as vinyl benzoate, vinyl p-tert-butylbenzoate or vinyl salicylate.

  Next, specific examples of the above hydroxyalkyl vinyl ethers include hydroxyethyl vinyl ether, hydroxypropyl vinyl ether or hydroxybutyl vinyl ether, and specific examples of the above alkyl vinyl ether include methyl vinyl ether, ethyl vinyl ether, n-propyl. Examples thereof include vinyl ether, n-butyl vinyl ether, iso-butyl vinyl ether and tert-butyl vinyl ether.

  Further, other hydrocarbon-based olefin copolymers copolymerizable with fluoroolefins include α-olefins such as ethylene, propylene or butene; vinyl halides excluding fluoroolefins such as vinyl chloride or vinylidene chloride ( Vinylidenes); aromatic vinyl compounds such as styrene, α-methylstyrene, p-tert-butylstyrene, o-methylstyrene or p-methylstyrene; (ethylenically unsaturated) double bonds such as maleic acid or fumaric acid Mono- or diesters of other basic acids containing; nitrogen-containing vinyl compounds such as (meth) acrylonitrile, (meth) acrylamide, N-methylolated (meth) acrylamide or N-butoxymethyl (meth) acrylamide; or (anhydrous) maleic acid Or (anhydrous) itaconic acid etc. It can also be used such as the sum) double bond-containing (anhydrous) polybasic acids, more can be used, such as allyl alcohol or allyl glycidyl ether.

The hydrocarbon-based olefin used for such copolymerization is selected from the viewpoint of solubility of the copolymer in a solvent or curing characteristics.
The fluoroolefin / hydrocarbon olefin copolymer is not particularly limited. For example, an alternating copolymer of tetrafluoroethylene and propylene, an alternating copolymer of tetrafluoroethylene and propylene, or vinylidene fluoride. , Alternating copolymers of chlorotrifluoroethylene and propylene, copolymers of tetrafluoroethylene or chlorotrifluoroethylene and ethyl vinyl ether, chloroethyl vinyl ether, isobutyl vinyl ether, copolymers of fluorine-containing olefin and hydroxy vinyl ether, chloroethyl Copolymers of vinyl ether and vinyl acetate, copolymers of fluorinated olefins and acrylic esters, copolymers of fluorinated olefins and methacrylates, copolymers of fluoroolefins and carboxylic acid vinyl esters Those made of, for example, coalescence is preferable.

In particular, the use of such a fluoroolefin / hydrocarbon olefin copolymer for the proton conducting membrane is desirable because the toughness of the proton conducting membrane can be improved.
The molecular weight of the fluorine-containing polymer [B] used in the present invention is 5,000 to 10,000,000, preferably 50,000 to 1,000,000 in terms of polystyrene-equivalent weight average molecular weight by gel permeation chromatography (GPC). If the molecular weight is too small, the excellent properties of the fluorine-containing polymer cannot be exhibited, and if the molecular weight is too large, it becomes difficult to produce a proton conducting membrane.

Configuration of Proton Conducting Membrane The proton conducting membrane according to the present invention contains the above [A] polyarylene copolymer and [B] a fluorine-containing polymer, and consists of [A] polyarylene copolymer. It has a sea-island structure composed of a continuous phase and a dispersed phase comprising [B] a fluorine-containing polymer.

Moreover, the proton conductive membrane of the present invention may contain a compatibilizer as necessary.
As such a compatibilizer, a known surfactant, a known polymer surfactant, or the like is used. Moreover, it is also possible to use as a compatibilizer a polymer obtained by copolymerizing a monomer having affinity with the polyarylene copolymer and a monomer having affinity with the fluorine-containing polymer. As such a polymer, a known polymer material such as a block copolymer, an alternating polymer, a random copolymer, or a star polymer can be used. The monomer having an affinity for the [A] polyarylene copolymer includes a polar group including a hydroxyl group, an ester group, an amide group, a carbamoyl group, a sulfamoyl group, an ether group, and a protonic acid group. . The monomer having an affinity for the [B] fluoropolymer is a fluoroalkyl group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkylene group, a substituted or unsubstituted aryl group, a substituted or non-substituted group. Those having a substituted arylene group are exemplified. By polymerizing the monomer components consisting of these two groups as described above, the intended polymer type compatibilizer is obtained. Preferred specific examples include polyvinyl acetal and polyvinyl butyral.

  The weight ratio of the polyarylene copolymer [A] and the fluoropolymer [B] in the proton conducting membrane used in the present invention is 99: 1 to 50:50, preferably 90:10 to 60: 40. The amount of the compatibilizer [C] used in the present invention is 0 to 2 parts by mass, preferably 100 parts by mass of the total amount of [A] polyarylene copolymer and [B] fluoropolymer. Is 0 to 0.5 parts by mass.

  When the weight ratio of the polyarylene copolymer and the fluorine-containing polymer is within the above range, a proton conductive membrane having good proton conductivity, toughness, heat resistance, chemical resistance, mechanical properties, and wear resistance can be obtained. .

In the sea-island structure, the shape of the dispersed phase composed of the fluorine-containing polymer is not particularly limited. Although the major axis average value of the dispersed phase is not particularly limited, a range of 0.001 to 1.0 μm is preferable. More preferably, it is 0.005-0.5 micrometer, More preferably, it is 0.01-0.2 micrometer.
When the average value of the major axis of the dispersed phase of the proton conducting membrane is in the above range, a proton conducting membrane having good proton conductivity, toughness, heat resistance, chemical resistance, mechanical properties, and wear resistance can be obtained.

Proton conductor of the production method the present invention of the proton conductive membrane, a compatibilizer having compatibility with each optionally polyarylene copolymer [A] and fluoropolymer [B] and were dissolved or dispersed in a solvent Thereafter, it is manufactured by forming a film.

  In this method, the sulfonic acid group of the polyarylene copolymer [A] may be previously neutralized with an alkali (alkali metal hydroxide, carbonate, ammonia or amines). The polyarylene copolymer [A] may be used as it is. Furthermore, you may use the [A] polyarylene-type copolymer which has a sulfonate group. The neutralized or ester group is converted to a sulfonic acid group by a treatment such as ion exchange or hydrolysis after film formation.

  It is preferable to use a combination in which the polyarylene copolymer [A], the fluorine-containing polymer [B], and the compatibilizer are all soluble in the solvent, but it is not always necessary that all of them be soluble in the solvent. One or more types may be dissolved in a solvent and the remaining components may be dispersed in the solvent. A desired proton conducting membrane can be obtained through a step of applying the polymer dispersion prepared in this manner onto a suitable substrate and removing the solvent.

  As the solvent used here, a known solvent can be used. Specific examples include polar solvents typified by pyridine, quinoline, pyrrolidone, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, N-methylpyrrolidone, cyclohexanone and the like, which give good results for the above purpose. be able to. Examples of solvents that may be used in combination with these solvents include methanol, alcohols typified by ethanol, acetone, ketones typified by 2-butanone, ethyl acetate, esters typified by butyl acetate, diethyl ether, Examples include tetrahydrofuran, ethers typified by dioxane, triethylamine, amines typified by ethylenediamine, and the like.

  The target polymer dispersion can be obtained by mixing and stirring or dispersing each of these materials and a solvent. When mixing the two, they may be heated and stirred, or may be mixed and dispersed using a dispersing device represented by a ball mill, an attritor, or a planetary mill. The coating solution thus prepared can be applied on the substrate using known coating means such as blade coating, wire bar coating, spin coating, spray coating, dip coating, and bead coating. it can.

[Membrane-electrode assembly]
The membrane-electrode assembly according to the present invention is a membrane-electrode assembly comprising the proton conducting membrane, a catalyst layer, and a gas diffusion layer on both sides of the proton conducting membrane. Typically, a catalyst layer for the cathode electrode is provided on one side and the catalyst layer for the anode electrode is provided on the other side of the proton conducting membrane, and the proton conduction of each catalyst layer on the cathode side and the anode side is further provided. Gas diffusion layers are provided on the cathode side and the anode side, respectively, in contact with the side opposite to the membrane.

Known gas diffusion layers and catalyst layers can be used without particular limitation.
Specifically, the gas diffusion layer is composed of a porous substrate or a laminated structure of a porous substrate and a microporous layer. When the gas diffusion layer is composed of a laminated structure of a porous substrate and a microporous layer, the microporous layer is provided in contact with the catalyst layer. The gas diffusion layers on the cathode side and the anode side preferably contain a fluoropolymer in order to impart water repellency.

The catalyst layer is composed of a catalyst and an ion exchange resin electrolyte. As the catalyst, a noble metal catalyst such as platinum, palladium, gold, ruthenium or iridium is preferably used. The noble metal catalyst may contain two or more elements such as an alloy or a mixture.
As such noble metal catalyst, one supported on high specific surface area carbon fine particles can be used.

  The ion exchange resin electrolyte functions as a binder component that binds the carbon carrying the catalyst, and efficiently supplies ions generated by the reaction on the catalyst to the proton conducting membrane at the fuel electrode, and protons at the air electrode. The ions supplied from the conductive membrane are efficiently supplied to the catalyst.

  The ion exchange resin for the catalyst layer used in the present invention is preferably a polymer having a proton exchange group in order to improve proton conductivity in the catalyst layer. Proton exchange groups contained in such polymers include sulfonic acid groups, carboxylic acid groups, and phosphoric acid groups, but are not particularly limited. A polymer having such a proton exchange group is also selected without any particular limitation, and a polymer having a proton exchange group composed of a fluoroalkyl ether side chain and a fluoroalkyl main chain, or a sulfonated polyarylene. Etc. are preferably used. In addition, a polyarylene copolymer having a sulfonic acid group constituting the proton conductive membrane may be used as an ion exchange resin, and a polymer containing a fluorine atom having a proton exchange group, ethylene, styrene, etc. Other polymers obtained from the above, copolymers or blends thereof may be used. As such an ion exchange resin electrolyte, known ones can be used without particular limitation, and for example, Nafion (DuPont, registered trademark), sulfonated polyarylene, etc. can be used without particular limitation.

  If necessary, a resin having no carbon fiber or ion exchange group may be used for the catalyst layer used in the present invention. These resins are preferably resins with high water repellency. For example, fluorine-containing copolymers, silane coupling agents, silicone resins, waxes, polyphosphazenes and the like can be mentioned, and fluorine-containing copolymers are preferred.

[Fuel cell]
The polymer electrolyte fuel cell according to the present invention includes the membrane-electrode assembly. Specifically, at least one electricity generation unit including at least one membrane-electrode assembly and separators located on both sides thereof; a fuel supply unit that supplies fuel to the electricity generation unit; and an oxidant as the electricity A solid polymer fuel cell including an oxidant supply unit for supplying to a generation unit, wherein the membrane-electrode assembly is as described above.

  As the separator used in the battery of the present invention, those used in ordinary fuel cells can be used. Specifically, carbon type or metal type can be used.

  Moreover, as a member which comprises a fuel cell, it is possible to use a well-known thing without a restriction | limiting in particular. The battery of the present invention can be used as a single cell or as a stack in which a plurality of single cells are connected in series. As a stacking method, a known method can be used. Specifically, planar stacking in which single cells are arranged in a plane and bipolar stacking in which single cells are stacked via separators each having a fuel or oxidant flow path formed on the back surface of the separator can be used. .

[Example]
Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

<Preparation of electrode paste>
Put 50 g of zirconia balls with a diameter of 5 mm (“YTZ ball” manufactured by Nikkato Co., Ltd.) into a 50 ml plastic bottle, 1.51 g of platinum-supported carbon particles (Pt: 46% by mass, “TEC10E50E” manufactured by Tanaka Kikinzoku Kogyo Co., Ltd.), distillation 0.88 g of water, 12.47 g of n-propyl alcohol and 4.59 g of a 20% by mass solution of Nafion (trade name, manufactured by DuPont) were added and stirred for 60 minutes with a paint shaker to obtain an electrode paste.

<Manufacture of electrodes>
The electrode paste is applied with a doctor blade on one side of the polymer electrolyte membrane prepared as described above using a mask having an opening of 5 cm × 5 cm, and 5 cm × on the surface where the electrode paste is not applied. The electrode paste was applied with a doctor blade using a mask having an opening of 5 cm. After drying this at 120 ° C. for 60 minutes, the amount of catalyst applied to each electrode catalyst layer was 0.50 mg / cm ² .

<Production of gas diffusion layer>
(1) Production of porous substrate Carbon paper (trade name: TGPH-060, manufactured by Toray Industries, Inc.) as a porous substrate is cut into a size of 5 cm x 5 cm, and this is 30 ml of 1.2 mass% polytetra After being immersed in a fluoroethylene resin fine particle dispersed aqueous solution for 5 minutes, it was dried in a 75 ° C. drying oven for 15 minutes. This substrate was baked in an electric furnace at 370 ° C. for 1 hour to produce a water repellent coated porous substrate for anode and cathode.

(2) Formation of microporous layer 2.4 g of carbon particles (trade name: Vulcan XC-72, manufactured by Cabot Corporation), 6.2 g of a 60% by mass polytetrafluoroethylene resin fine particle dispersed aqueous solution, 104.9 g of distilled water, a dispersing agent (Trade name: TRITON-100, manufactured by Sigma-Aldrich) 10.3 g was mixed, and this mixture was stirred using a planetary ball mill (trade name: P-5, manufactured by Fritsch) until uniform. A paste for forming a microporous layer was prepared. After applying this paste uniformly using an applicator so that the weight of the microporous layer is 1.0 mg / cm ² , the paste is dried in a drying oven at 75 ° C. for 30 minutes to provide a water repellent coating with a microporous layer. A porous substrate was prepared.

<Fabrication of fuel cell>
The electrolyte membrane having the electrode catalyst layer formed on both sides is sandwiched between two gas diffusion layers and hot press molded under a pressure of 60 kg / cm ² and a temperature of 160 ° C. for 20 minutes to produce a membrane-electrode assembly. did. The obtained electrode-membrane assembly was sandwiched between two titanium current collectors, and a heater was placed on the outside thereof to produce a fuel cell for evaluation having an effective area of 25 cm ² .

<Dry and wet cycle durability evaluation>
(1) Dry / wet cycle test The temperature of the fuel cell is maintained at 70 ° C., and the relative humidity is 100% for 10 minutes and the relative humidity is 0% (relative humidity of dry nitrogen gas) for 40 minutes. As a cycle, nitrogen was supplied at atmospheric pressure, the hydrogen crossover amount was measured every 10 cycles, and the test was continued until the number of cycles became 10 times or more the hydrogen crossover amount before the wet and dry cycle evaluation.

(2) Measurement of hydrogen crossover amount Maintaining the temperature of the fuel cell at 70 ° C., supplying hydrogen to the anode electrode and nitrogen to the cathode electrode at atmospheric pressure at a relative humidity of 100% to the anode electrode and the cathode electrode. The hydrogen crossover amount was calculated from the average value of the oxidation current when held at 4 V for 1 hour.

<Measurement of proton conductivity>
The obtained proton conducting membrane is processed into a strip-like membrane sample having a width of 5 mm, a platinum wire (diameter 0.5 mm) is pressed against the surface of the sample, the sample is held in a constant temperature and humidity apparatus, AC resistance was obtained from AC impedance measurement. That is, the impedance at AC 10 kHz was measured in an environment of 85 ° C. and relative humidity 90%. A chemical impedance measurement system manufactured by NF Circuit Design Block Co., Ltd. was used as the resistance measurement device, and JW241 manufactured by Yamato Scientific Co., Ltd. was used as the constant temperature and humidity device. Five platinum wires were pressed at intervals of 5 mm, the distance between the wires was changed to 5 to 20 mm, and the AC impedance was measured. The slope between each resistance line was measured from the AC impedance, the specific resistance of the membrane was calculated from the distance between the lines and the slope between the resistance lines, and the proton conductivity was calculated from the reciprocal of the specific resistance and the film thickness.
Specific resistance R (Ω · cm) = 0.5 (cm) × film thickness (cm) × resistance-to-resistance gradient (Ω / cm)

[Synthesis Example 1]: Synthesis of hydrophobic unit D 2,6-dichlorobenzonitrile was added to a 1 l three-necked flask equipped with a stirrer, a thermometer, a condenser tube, a Dean-Stark tube, and a three-way cock for introducing nitrogen. 49.4 g (0.29 mol), 2,2-bis (4-hydroxyphenyl) -1,1,1,3,3,3-hexafluoropropane 88.4 g (0.26 mol), potassium carbonate 47.3 g (0.34 mol) was weighed. After substitution with nitrogen, 346 ml of sulfolane and 173 ml of toluene were added and stirred. The flask was placed in an oil bath and heated to reflux at 150 ° C. When water produced by the reaction was azeotroped with toluene and reacted while being removed from the system with a Dean-Stark tube, almost no water was observed in about 3 hours. After removing most of the toluene while gradually raising the reaction temperature, the reaction was continued at 200 ° C. for 3 hours. Next, 12.3 g (0.072 mol) of 2,6-dichlorobenzonitrile was added and reacted for another 5 hours.

  The resulting reaction solution was allowed to cool and then diluted by adding 100 ml of toluene. The precipitate of the inorganic compound produced as a by-product was removed by filtration, and the filtrate was put into 2 l of methanol. The precipitated product was separated by filtration, collected, dried, and dissolved in 250 ml of tetrahydrofuran. This was reprecipitated in 2 l of methanol to obtain 107 g of the objective compound.

  The number average molecular weight in terms of polystyrene determined by GPC (THF solvent) of the obtained target compound was 7300. The obtained compound was an oligomer represented by Structural Formula D-1.

［合成例２］：ポリアリーレン系共重合体の合成
乾燥したＮ，Ｎ−ジメチルアセトアミド（ＤＭＡｃ）５４０ｍｌを、３−（２，５−ジクロロベンゾイル）ベンゼンスルホン酸ネオペンチル１３５．０ｇ（０．３３６ｍｏｌ）と、合成例１で合成した疎水性ユニットＤ４０．７ｇ（５．６ｍｍｏｌ）、２，５−ジクロロ−４'−（１−イミダゾリル）ベンゾフェノン６．７１ｇ（１６．８ｍｍｏｌ）、ビス（トリフェニルホスフィン）ニッケルジクロリド６．７１ｇ（１０．３ｍｍｏｌ）、トリフェニルホスフィン３５．９ｇ（０．１３７ｍｏｌ）、ヨウ化ナトリウム１．５４ｇ（１０．３ｍｍｏｌ）、亜鉛５３．７ｇ（０．８２１ｍｏｌ）の混合物中に窒素下で加えた。

[Synthesis Example 2]: Synthesis of polyarylene copolymer 540 ml of dried N, N-dimethylacetamide (DMAc) was added to 135.0 g (0.336 mol) of neopentyl 3- (2,5-dichlorobenzoyl) benzenesulfonate. And 40.7 g (5.6 mmol) of the hydrophobic unit D synthesized in Synthesis Example 1, 6.71 g (16.8 mmol) of 2,5-dichloro-4 ′-(1-imidazolyl) benzophenone, bis (triphenylphosphine) In a mixture of nickel dichloride 6.71 g (10.3 mmol), triphenylphosphine 35.9 g (0.137 mol), sodium iodide 1.54 g (10.3 mmol), zinc 53.7 g (0.821 mol) under nitrogen. Added in.

  The reaction system was heated with stirring (finally heated to 79 ° C.) and reacted for 3 hours. An increase in viscosity in the system was observed during the reaction. The polymerization reaction solution was diluted with 730 ml of DMAc, stirred for 30 minutes, and filtered using Celite as a filter aid.

  A part of the filtrate was poured into methanol and solidified. The molecular weight of the copolymer consisting of a sulfonic acid derivative protected with a neopentyl group, as determined by gel permeation chromatography (GPC), was Mn = 58,000 and Mw = 135,300.

  The filtrate was concentrated with an evaporator, 43.8 g (0.505 mol) of lithium bromide was added to the filtrate, and the mixture was reacted at an internal temperature of 110 ° C. for 7 hours under a nitrogen atmosphere. After the reaction, the mixture was cooled to room temperature, poured into 4 l of acetone and solidified. The coagulum was collected by filtration, air-dried, pulverized with a mixer, and washed with 1500 ml of 1N hydrochloric acid while stirring. After filtration, the product was washed with ion exchanged water until the pH of the washing solution reached 5 or higher, and then dried at 80 ° C. overnight to obtain 23.0 g of the desired polyarylene copolymer. The molecular weight of the polyarylene copolymer after deprotection was Mn = 60,000 and Mw = 175,000. The ion exchange capacity of this polymer was 2.4 meq / g. The resulting polyarylene copolymer D-N1 is a compound represented by the structural formula D-2.

［実施例１］
合成例２で得られたポリアリーレン系共重合体に対し、フッ素系重合体（ポリフッ化ビニリデン；型番３０１Ｆ、エルフ・アトケム社製）が２０質量％となるように、Ｎ−メチル−２−ピロリドンに溶解してポリマー溶液を得た。得られたポリマー溶液の粘度は６０００ｍＰａ・ｓであった。

[Example 1]
N-methyl-2-pyrrolidone so that the fluorine-containing polymer (polyvinylidene fluoride; model number 301F, manufactured by Elf Atchem) is 20% by mass with respect to the polyarylene copolymer obtained in Synthesis Example 2. To obtain a polymer solution. The viscosity of the obtained polymer solution was 6000 mPa · s.

The obtained polymer solution was applied onto a PET film with a doctor blade and then dried to form a proton conducting membrane.
When the obtained proton conducting membrane was observed with a transmission electron microscope, a continuous phase composed of a polyarylene copolymer and a dispersed phase composed of a fluoropolymer were observed. The average major axis value of the dispersed phase was 0.05 μm.

In addition, a membrane electrode assembly and a fuel cell were produced using the obtained proton conducting membrane and subjected to a wet and dry cycle durability evaluation. As a result, the proton conductivity before the durability test was 0.34 S / cm, the hydrogen crossover amount. Was 15 mmol / h / cm ² , whereas the hydrogen crossover amount after 200 cycles in the dry / wet cycle test was 20 mmol / h / cm ² , which was 10% of the hydrogen crossover amount before the dry / wet cycle evaluation. It was less than double. The dry / wet cycle test was completed up to 200 times.

[Example 2]
With respect to the polyarylene copolymer obtained in Synthesis Example 2, the N-methyl-2-propylene polymer (tetrafluoroethylene-propylene copolymer; manufactured by Taihei Kasei Co., Ltd.) is 20% by mass. Dissolved in pyrrolidone. The viscosity of the polymer solution was 7000 mPa · s.

The obtained polymer solution was applied onto a PET film with a doctor blade and then dried to form a proton conducting membrane.
When the obtained proton conducting membrane was observed with a transmission electron microscope, a continuous phase composed of a polyarylene copolymer and a dispersed phase composed of a fluoropolymer were observed. The long axis average value of the dispersed phase was 0.1 μm.

In addition, a membrane electrode assembly and a fuel cell were produced using the obtained proton conducting membrane and subjected to a wet and dry cycle durability evaluation. As a result, the proton conductivity before the durability test was 0.34 S / cm, the hydrogen crossover amount. Was 15 mmol / h / cm ² , whereas the hydrogen crossover amount after 200 cycles in the dry / wet cycle test was 18 mmol / h / cm ² , which was 10% of the hydrogen crossover amount before the dry / wet cycle evaluation. It was less than double. The dry / wet cycle test was completed up to 200 times.

[Comparative Example 1]
The polyarylene copolymer obtained in Synthesis Example 2 was dissolved in N-methyl-2-pyrrolidone. The viscosity of the polymer solution was 5000 mPa · s.

The obtained polymer solution was applied onto a PET film with a doctor blade and then dried to form an ion exchange resin layer on the surface.
Using the obtained proton conducting membrane, a membrane electrode assembly and a fuel cell were produced and subjected to a wet and dry cycle durability evaluation. As a result, the proton conductivity before the durability test was 0.33 S / cm, and the hydrogen crossover amount was whereas there was a 14mmol / h / cm ^2, hydrogen crossover amount dry-wet cycle test 30 times became 154mmol / h / cm ^2, and the wet-dry cycle costing 10 times or more of the preceding hydrogen crossover amount .

Claims (11)

[A] a condensed aromatic ring structural unit represented by the formula (2);
A polyarylene-based copolymer comprising a structural unit having a sulfonic acid group represented by the following formula (13);
[B] a proton conducting membrane containing a fluorine-containing polymer,
[A] A proton conducting membrane having a continuous phase composed of a polyarylene copolymer and a dispersed phase composed of [B] a fluorine-containing polymer.

Wherein (2), A, D is a direct bond, -O -, - S -, - CO -, - SO 2 -, - SO -, - CONH -, - COO -, - (CF 2) i - (I is an integer of 1 to 10), — (CH ₂ ) _j — (j is an integer of 1 to 10), —CR ′ ₂ — (R ′ is an aliphatic hydrocarbon group, aromatic hydrocarbon) Group or a halogenated hydrocarbon group), at least one structure selected from the group consisting of a cyclohexylidene group and a fluorenylidene group, B represents an oxygen atom or a sulfur atom, and Ph represents a condensed aromatic ring structure R _{1 to} R ₂₀ may be the same or different from each other, and may be a hydrogen atom, a fluorine atom, an alkyl group, or a halogenated alkyl group in which part or all of them are halogenated. , Allyl group, aryl group, nitro group and nitrile group It represents at least one atom or group. l and m represent an integer of 0 to 4, and q represents an integer of 2 or more. t shows the integer of 0-4. n and p show the composition ratio of each structural unit, p is 0 to 1, and n + p = 1.

(In formula (13), Z represents a direct bond or at least one structure selected from the group consisting of —O— and —S—, and Y represents —CO—, —SO ₂ —, —SO—. , —CONH—, —COO—, — (CF ₂ ) _{1 ′} — (wherein 1 ′ is an integer of 1 to 10), and —C (CF ₃ ) ₂ —. Ar represents an aromatic group having a substituent represented by —SO ₃ H, —O (CH ₂ ) _h SO ₃ H or —O (CF ₂ ) _h SO ₃ H (h represents 1 to 12). C represents an integer of 0 to 10, d represents an integer of 0 to 10, and k represents an integer of 1 to 4.)
Of the single wires at the end of each structural unit, one not having a substituent displayed on one side means connection with an adjacent structural unit. ] The proton conductive membrane according to claim 1, wherein the polyarylene copolymer [A] includes a structural unit having a nitrogen-containing heterocyclic group represented by the following formula (9).

In formula (9), Z represents a direct bond or at least one structure selected from the group consisting of —O— and —S—, and Y represents —CO—, —SO ₂ —, —SO—, -CONH -, - COO -, - (CF 2) l '- (l' is an integer of 1 to 10), - at least one structure selected from the group consisting of - C (CF _{3) 2} R ₂₁ represents a nitrogen-containing heterocyclic group. b shows the integer of 1-5, a shows the integer of 0-4.   The fluorine-containing polymer [B] is at least one selected from a vinylidene fluoride polymer, a tetrafluoroethylene-propylene copolymer, a fluorine-containing olefin / vinyl ether copolymer, and a fluorine-containing olefin / vinyl ester copolymer. The proton conducting membrane according to claim 1, wherein the proton conducting membrane is provided.   The proton conducting membrane according to any one of claims 1 to 3, wherein the average value of the major axis of the dispersed phase made of the fluorine-containing polymer contained in the proton conducting membrane is 0.001 to 1.0 µm.   The weight ratio of the polyarylene copolymer [A] and the fluorine-containing polymer [B] in the proton conducting membrane is 99: 1 to 50:50, according to any one of claims 1 to 4. Proton conducting membrane.   In the formula (2), Ph is a divalent group derived from an aromatic ring selected from the group consisting of naphthalene, anthracene, tetracene, and pentacene. Proton conducting membrane. The proton conductive membrane according to any one of claims 1 to 6, wherein the condensed aromatic ring structural unit is represented by the following formula (3):

Wherein (3), A is a direct bond, -O -, - CO -, - SO 2 -, - SO -, - (CF 2) i - (i is an integer of 1 to 10), - ( CH ₂ ) _j — (j is an integer of 1 to 10), —CR ′ ₂ — (R ′ represents an aliphatic hydrocarbon group, an aromatic hydrocarbon group or a halogenated hydrocarbon group), cyclohexylidene At least one structure selected from the group consisting of a group and a fluorenylidene group,
D is a direct bond, —O—, —CO—, — (CH ₂ ) _j — (j is an integer of 1 to 10) and —CR ′ ₂ — (R ′ is an aliphatic hydrocarbon group, aromatic carbonization. Represents at least one structure selected from the group consisting of a hydrogen group or a halogenated hydrocarbon group),
Ph represents a divalent group having a condensed aromatic ring, R _{1 to} R ₂₀ may be the same or different from each other, and a hydrogen atom, a fluorine atom, an alkyl group, a part or all of them are halogenated. And at least one atom or group selected from the group consisting of a halogenated alkyl group, an allyl group, an aryl group, a nitro group and a nitrile group.
l represents an integer of 0 to 4, and q represents an integer of 2 or more. t shows the integer of 0-4.
n and p show the composition ratio of each structural unit, p is 0 to 1, and n + p = 1.
Among the single lines at the end of the structural unit, those not having a substituent displayed on one side mean connection with the adjacent structural unit. ] The proton conductive membrane according to claim 7, wherein the condensed aromatic ring structural unit is represented by the following formula (4):

[In the formula (4), D is selected from the group consisting of —O— and —CR ′ ₂ — (R ′ represents an aliphatic hydrocarbon group, an aromatic hydrocarbon group or a halogenated hydrocarbon group). At least one structure is shown.
P is at least one structure selected from structures represented by the following formulas (5-1) to (5-3),
Ph is a structure represented by the following formula (6).
q represents an integer of 2 or more. t shows the integer of 0-4.
n and p show the composition ratio of each structural unit, p is 0 to 1, and n + p = 1.
Among the single lines at the end of the structural unit, those not having a substituent displayed on one side mean connection with the adjacent structural unit. ]

[A] a polyarylene copolymer comprising a condensed aromatic ring structural unit represented by the formula (2) and a structural unit having a sulfonic acid group represented by the formula (13); [B] a fluorine-containing polymer,
A method for producing a proton conducting membrane having a continuous phase composed of [A] a polyarylene copolymer and a dispersed phase composed of [B] a fluorine-containing polymer, wherein the membrane is formed after being dissolved or dispersed in a solvent.   A membrane-electrode assembly comprising the proton conducting membrane according to any one of claims 1 to 8, and a catalyst layer and a gas diffusion layer on both sides of the proton conducting membrane.   A solid polymer electrolyte fuel cell comprising the membrane-electrode assembly according to claim 10.