JP2009224133A - Polymer electrolyte for direct methanol fuel cell, and its usage - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polymer electrolyte which suppresses permeation of methanol without lowering conductivity (increasing membrane resistance) by addition of an inorganic component by solving problems due to composition, and which is superior in dimension stabililty in a methanol solution, and a proton conductive membrane for a fuel cell consisting of the electrolyte. <P>SOLUTION: The polymer electrolyte includes a proton conductive material (A) and a reactant (B) which is obtained by carrying out hydrolysis and dehydration-condensation reaction of a composition containing a specific nitrogen-contained silane compound and a specific protonic acid group-containing silane compound. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention is an inorganic proton conductive component that can be used in electrolytes for primary batteries, electrolytes for secondary batteries, polymer solid electrolytes for fuel cells, display elements, various sensors, signal transmission media, solid capacitors, ion exchange membranes, and the like. The present invention relates to a polymer electrolyte for a direct methanol fuel cell in which is combined.

A fuel cell is a power generation system that has high power generation efficiency and a low burden on the environment with less emissions. In recent years, with the growing interest in protecting the global environment and escaping from fossil fuel dependence, it is in the spotlight. Fuel cells are expected to be installed in small distributed power generation facilities, power generation devices as driving sources for moving bodies such as automobiles and ships, and mobile phones and mobile personal computers that replace secondary batteries such as lithium ion batteries. ing.
A polymer electrolyte fuel cell is provided with a pair of electrodes on both sides of a proton-conducting solid polymer electrolyte membrane, and supplies pure hydrogen or reformed hydrogen gas as fuel to one electrode (fuel electrode). Air is supplied as an oxidizing agent to different electrodes (air electrodes) to obtain an electromotive force. In water electrolysis, water is electrolyzed using a solid polymer electrolyte membrane to produce a reverse reaction of the fuel cell reaction to produce hydrogen and oxygen.
However, in actual fuel cells and water electrolysis, side reactions occur in addition to these main reactions. A typical example is the generation of hydrogen peroxide (H ₂ O ₂ ), and the radical species resulting from the hydrogen peroxide cause the solid polymer electrolyte membrane to deteriorate.
Conventionally, as solid polymer electrolyte membranes, Nafion (registered trademark, manufactured by DuPont), Aciplex (registered trademark, manufactured by Asahi Kasei Kogyo Co., Ltd.), Flemion (registered trademark, manufactured by Asahi Glass Co., Ltd.) Perfluorosulfonic acid membranes commercially available from U.S.A. have been used because of their excellent chemical stability.
However, since perfluorosulfonic acid membranes such as Nafion are difficult to manufacture, there is a problem that they are very expensive, and are widely used in consumer applications such as fuel cell vehicles and household fuel cell power generation systems. It is an obstacle. In addition, since it has a large amount of fluorine atoms in the molecule, the disposal treatment after use also has a problem of a heavy load on the environment.
In addition, the higher the temperature of the fuel cell and the thinner the proton conducting membrane between the electrodes, the smaller the membrane resistance and the higher the power generation output. However, these perfluoro acid-based membranes have a heat distortion temperature of about 80 to 100 ° C. and very poor creep resistance at high temperatures. Therefore, the power generation temperature when these membranes are used in a fuel cell is 80 ° C. There is a problem that power generation output is limited because it must be kept below. In addition, the film thickness is poor when used for a long period of time, and a certain degree of film thickness (50 μm or more) is necessary to prevent short-circuiting between the electrodes. Yes.
In order to solve such problems of perfluorosulfonic acid membranes, solid polymer electrolyte membranes that do not contain fluorine atoms, are cheaper, and have a heat-resistant main chain skeleton that is also used for engineer plastics are currently available. Many studies have been conducted. Polymers in which a main chain aromatic ring of polyarylene, polyether ether ketone, polyether sulfone, polyphenylene sulfide, polyimide, or polybenzazole is sulfonated have been proposed (Non-Patent Documents 1 to 3).
Further, a method of supplying a liquid instead of pure hydrogen or reformed hydrogen gas, particularly a methanol aqueous solution, is attracting attention as a direct methanol fuel cell as an alternative to a lithium ion battery. Many fuel cells using Nafion as an electrolyte membrane for a direct methanol fuel cell have been studied, but there is a problem that it is difficult to avoid a methanol crossover when using a high concentration of methanol. Therefore, polymers with sulfonated main chain aromatic rings such as polyarylene, polyetheretherketone, polyethersulfone, polyphenylene sulfide, polyimide, and polybenzazole have been studied as non-perfluorosulfonic acid membranes. However, sufficient methanol permeation suppression ability is not obtained.
By the way, organic-inorganic composite materials in which inorganic components are combined with organic polymer materials have been studied for a long time to improve gas permeability, strength, thermal stability, optical properties, electrical properties, etc. Yes. When compounding, it is important for the expression of physical properties to be compounded in nano and micro order, and therefore, a method of compounding organic polymer material and inorganic component using chemical interaction is generally used. (Non-Patent Documents 4 to 6).
In order to suppress methanol permeation, composite electrolyte membranes have also been studied, and it has been found that composite permeation with inorganic components has a remarkable effect on methanol permeation suppression. However, when an inorganic component is added to the proton conductive material, the tendency of the proton conductivity to decrease is generally observed (Non-patent Documents 7 and 8, Patent Documents 1 to 3). This is because the proton conduction path is cut by the addition of the inorganic component, and the proton conduction is achieved by ionic or covalent bonding of the protonic acid group that contributes to proton conduction and the inorganic component for complexation. It is thought that the cause is that it is inhibited.
PolymerPreprints, Japan, Vol. 42, no. 7, p. 2490-2492 (1993) PolymerPreprints, Japan, Vol. 43, no. 3, p. 735-736 (1994) PolymerPreprints, Japan, Vol. 42, no. 3, p730 (1993) Polymer, Vol. 38, no. 6, 1345-1356 (1997). PolymerPreprints, Japan, Vol. 48, no. 14, 4245-4246 (1999). JournalofMembraneScience, Vol. 157, 219-226 (1999). JournalofMembraneScience, Vol. 203, 215-225 (2002). Macromol. Chem. Phys. , Vol. 207, 336-341 (2006). Japanese Patent No. 3513097 JP 2006-2449 A JP 2007-73201 A

In those described in Non-Patent Documents 1 to 3, a polymer in which a main chain aromatic ring is sulfonated has a large water absorption and inferior hot water resistance, so that the introduction amount of a hydrophilic group such as a sulfonic acid group is limited. . Moreover, it was a material with poor Fenton reagent resistance (hydroxy radical resistance), which is a measure of power generation durability. In addition, when these electrolyte membranes are exposed to a high temperature of 100 ° C. or higher for a long period of time, the sulfonic acid is eliminated, resulting in a decrease in proton conduction performance, or crosslinking with other aromatic rings into which sulfonic acid groups are not introduced. It had the problem of causing reaction and embrittlement. If the membrane becomes more brittle, there is a high possibility that the membrane will break (pinhole) during long-term power generation and power generation becomes impossible.
In addition, as in Non-Patent Documents 4 to 8 and Patent Documents 1 to 3, while methanol permeation can be generally suppressed by addition of inorganic components, proton conductivity decreases (in the case of membrane resistance), There is a so-called trade-off relationship.
Thus, what has been proposed heretofore has not always been excellent in balance between proton conductivity and methanol permeability. Accordingly, an object of the present invention is to solve the problems caused by the complexization that has been studied in the past, to suppress the permeation of methanol without lowering the conductivity (increasing the membrane resistance) by adding an inorganic component, and to provide a methanol solution. It is an object of the present invention to provide a polymer electrolyte excellent in dimensional stability and a fuel cell for a direct methanol fuel cell containing the electrolyte.

As a result of intensive studies to achieve the above object, the present inventors have added a proton conductive material (A), a composition containing a specific nitrogen-containing silane compound and a specific proton acid group-containing silane compound. The inventors have found that the polymer electrolyte containing the reaction product (B) obtained by the decomposition / dehydration condensation reaction as an essential material is a novel material that satisfies the object of the present invention, and has completed the present invention. That is, the gist of the present invention is as follows.
[1] (A) a proton conductive polymer, and
(B) a reaction product obtained by subjecting a composition containing the following components (Ba) and (BB) to hydrolysis / dehydration condensation reaction;
(Ba): Compound represented by the following formula (6) (Bb): Compound represented by the following formula (7),
A polymer electrolyte for a direct methanol fuel cell, comprising:
Si (OR ²⁰ ) _E (R ²¹ ) _F (R ²² ) _G ... (6)
(In the formula (6), E is 2 to 3, F is 0 to 1, G is 1 to 2, and E + F + G = 4. Also, R ²⁰ and R ²¹ are hydrogen atoms or halogenated. R ²² is a nitrogen-containing heterocyclic structure or an optionally halogenated hydrocarbon group having an optionally substituted amino group.)
Si (OR ³⁰ ) _{E '} (R ³¹ ) _F' (R ³² ) _{G '} (7)
(In the formula (7), E ′ is 2 to 3, F ′ is 0 to 1, G ′ is 1 to 2, and E ′ + F ′ + G ′ = 4. Also, R ³⁰ and R ³¹ are A hydrogen atom or an optionally halogenated hydrocarbon group, and R ³² is an optionally halogenated hydrocarbon group having a protonic acid group.)
[2] The component (B) is a reaction product obtained by hydrolysis / dehydration condensation reaction of a composition containing the components (Ba), (BB) and the following component (BC). [1] The polymer electrolyte for direct methanol fuel cells.
(Bc): Compound represented by the following formula (8) other than the components (Ba) and (Bb)
Si (OR ⁴⁰ ) _e (R ⁴¹ ) _f (8)
(In the formula (8), e is 2 to 4, f is 0 to 2, and e + f = 4. R ⁴⁰ and R ⁴¹ are a hydrogen atom or an optionally halogenated hydrocarbon group. )
[3] The component (B) is the component (Ba), (Bb), (Bc) and the following component (B-
The polymer electrolyte for a direct methanol fuel cell according to [2], which is a reaction product obtained by subjecting a composition containing d) to hydrolysis / dehydration condensation reaction.
(Bd): Al, Ti or Zr alkoxide
[4] The group represented by R ²² in the formula (6) representing the component (Ba) is a pyrrole group, a thiazole group, a benzothiazole group, an isothiazole group, an oxazole group, a benzoxazole group, or an isoxazole. Group, imidazole group, imidazoline group, imidazolidine group, benzimidazole group, pyrazole group, triazine group, pyridine group, pyrimidine group, pyridazine group, pyrazine group, indole group, quinoline group, isoquinoline group, bromine group, tetrazole group, tetrazine Group, triazole group, carbazole group, acridine group, quinoxaline group, quinazoline group, indolizine group, isoindole group, 3H-indole group, 2H-pyrrole group, 1H-indazole group, purine group, phthalazine group, naphthyridine group, cinnoline Group, pteridine group, carboline group, phenanthate Lysine group, perimidine group, phenanthroline group, phenazine group, phenalsazine group, phenothiazine group, furazane group, phenoxazine group, pyrrolidine group, pyrroline group, pyrazoline group, pyrazolidine group, piperidine group, piperazine group, indoline group, isoindoline group, Direct methanol type [1] to [3] which is at least one group derived from a compound selected from the group consisting of quinuclidine group, primary amino group, secondary amino group, tertiary amino group and derivatives thereof Polymer electrolyte for fuel cells.

[5] The group represented by R ²² in the formula (6) representing the component (Ba) is an imidazole group, an imidazoline group, a pyridine group, a pyrrole group, a benzimidazole, a benzoxazole, a triazine group, or a triazole. [1] to [4] a polymer electrolyte for a direct methanol fuel cell, comprising at least one group selected from the group consisting of a group, a primary amine group, a secondary amine group, and a tertiary amine group.
[6] The group represented by R ⁴⁰ and R ⁴¹ in the formula (8) representing the component (Bc) is a methyl group, an ethyl group, a propyl group, an iso-propyl group, or an n-propyl group. , At least one group selected from the group consisting of hydrocarbon groups consisting of butyl, iso-butyl, hexyl, octyl, decyl, dodecyl, cyclopentyl, cyclohexyl, phenyl, trifluoropropyl [1] to [5] comprising a polymer electrolyte for a direct methanol fuel cell.
[7] The polymer electrolyte for direct methanol according to [1] to [6], wherein the component (Bd) contains a titanium alkoxide.
[8] The direct methanol type of [1] to [7], wherein the component (A) has at least one group selected from the group consisting of a sulfonic acid group, a carboxylic acid group, a phosphoric acid group and a phenolic hydroxyl group Polymer electrolyte for fuel cells.
[9] The component (A) is a perfluorosulfonic acid polymer, a perfluorocarbon polymer having a carboxyl group and a sulfonic acid group, and a polyether ketone or polyether ether ketone having a sulfonic acid or alkylsulfonic acid group , Polysulfide, polyphosphazene, polyarylene, polyphenylene, polybenzimidazole, polyethersulfone, polyetherethersulfone, polyphenylene oxide, polyimide, polysulfone, polysulfonate, polybenzimidazole, polybenzoxazole, polybenzothiazole, polythiazole, poly For direct methanol fuel cells of [1] to [8], which is at least one selected from the group consisting of phenylquinoxaline, polyquinoline, polysiloxane, and polytriazine Molecular electrolyte.
[10] The polymer electrolyte for a direct methanol fuel cell according to [1] to [9], wherein the component (A) is a polyarylene copolymer containing a structural unit represented by the following general formula (1).

Wherein Y is —CO—, —SO ₂ —, —SO—, —CONH—, —COO—, — (CF ₂ ) ₁ — (l is an integer of 1 to 10), —C (CF ₃ ) represents at least one structure selected from the group consisting of ₂ —, Z is a direct bond, or — (CH ₂ ) ₁ — (l is an integer of 1 to 10), —C (CH ₃ ) ₂ represents at least one structure selected from the group consisting of —, —O—, and —S—, and Ar represents —SO ₃ H or —O (CH ₂ ) _p SO ₃ H or —O (CF ₂ ) _p An aromatic group having a substituent represented by SO ₃ H. p represents an integer of 1 to 12, m represents an integer of 0 to 10, n represents an integer of 0 to 10, and k represents 1 Represents an integer of ~ 4.)
[11] The polymer electrolyte for a direct methanol fuel cell according to [1] to [10], wherein the component (A) is a polyarylene copolymer containing a structural unit represented by the following general formula (2).

(In the formula, A and D are independently a direct bond, or —CO—, —SO ₂ —, —SO—, —CONH.
-, - COO -, - ( CF 2) l - (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 group, —O—, and —S—. B represents independently an oxygen atom or a sulfur atom, R ^{1 to} R ¹⁶ 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 It represents at least one atom or group selected from the group consisting of halogenated alkyl groups, allyl groups, aryl groups, nitro groups, and nitrile groups. s and t represent an integer of 0 to 4, and r represents 0 or an integer of 1 or more.

[12] The polymer electrolyte for a direct methanol fuel cell according to [1] to [11], having an ion exchange capacity of 0.1 to 5 meq / g.
[13] A step of hydrolyzing and condensing the following components (Ba) to (Bd) to obtain a hydrolysis condensate, a step of concentrating the solvent in the hydrolysis condensate to change the solvent composition, (A ) And the hydrolysis-condensation product in a solvent are coated on a substrate to form a coating film, and at least a part of the solvent contained in the coating film is removed to remove the polymer electrolyte. A method for producing a polymer electrolyte membrane for a direct methanol fuel cell, comprising a step of forming a membrane.
(Ba): Compound represented by the following formula (6) (Bb): Compound represented by the following formula (7),
(Bc): a compound represented by the following formula (8) other than the components (Ba) and (Bb), and (Bd) an alkoxide of Al, Ti, or Zr
Si (OR ²⁰ ) _E (R ²¹ ) _F (R ²² ) _G ... (6)
(In the formula (6), E is 2 to 3, F is 0 to 1, G is 1 to 2, and E + F + G = 4. Also, R ²⁰ and R ²¹ are hydrogen atoms or halogenated. R ²² is a nitrogen-containing heterocyclic structure or an optionally halogenated hydrocarbon group having an optionally substituted amino group.)
Si (OR ³⁰ ) _{E '} (R ³¹ ) _F' (R ³² ) _{G '} (7)
(In the formula (7), E ′ is 2 to 3, F ′ is 0 to 1, G ′ is 1 to 2, and E ′ + F ′ + G ′ = 4. Also, R ³⁰ and R ³¹ are A hydrogen atom or an optionally halogenated hydrocarbon group, and R ³² is an optionally halogenated hydrocarbon group having a protonic acid group.)
Si (OR ⁴⁰ ) _e (R ⁴¹ ) _f (8)
(In the formula (8), e is 2 to 4, f is 0 to 2, and e + f = 4. R ⁴⁰ and R ⁴¹ are a hydrogen atom or an optionally halogenated hydrocarbon group. )
[14] A polymer electrolyte membrane in which a reaction product obtained by hydrolytic condensation of the following components (Ba) and (BB) is compatible or dispersed in the component (A).
(A) a proton conductive polymer;
(Ba): a compound represented by the following formula (6),
Si (OR ²⁰ ) _E (R ²¹ ) _F (R ²² ) _G (6)
(In Formula (6), E is 2-3, F is 0-1, G is 1-2, and E + F + G = 4. R ²⁰ and R ²¹ are hydrogen atoms or halogenated. R ²² is a nitrogen-containing heterocyclic structure or an optionally halogenated hydrocarbon group having an optionally substituted amino group.)
(Bb): a compound represented by the following formula (7),
Si (OR ³⁰ ) _{E '} (R ³¹ ) _F' (R ³² ) _{G '} (7)
(In the formula (7), E ′ is 2 to 3, F ′ is 0 to 1, G ′ is 1 to 2, and E ′ + F ′ + G ′ = 4. R ³⁰ and R ³¹ are hydrogen. (It is an optionally halogenated hydrocarbon group. R ³² is an optionally halogenated hydrocarbon group having a protonic acid group.)

The polymer electrolyte for direct methanol fuel cell of the present invention has firstly improved proton conductivity while suppressing methanol permeation, and secondly improved dimensional stability in aqueous methanol solution. It has a characteristic that was not seen before.
Therefore, the polymer electrolyte of the present invention includes an electrolyte for primary batteries, an electrolyte for secondary batteries, a solid polymer electrolyte for direct methanol fuel cells, a display element, various sensors, a signal transmission medium, a solid capacitor, an ion exchange membrane, and the like. It can be used as a conductive film, and its industrial significance is extremely great.

Hereinafter, the present invention will be described in detail.

[Polymer electrolyte for direct methanol fuel cell]
The polymer electrolyte for a direct methanol fuel cell according to the present invention comprises (A) a proton conductive polymer, and
(B) A composition comprising the components (Ba) and (Bb), preferably the components (Bc) and (Bd) in addition to the components (Ba) and (BB). And a reaction product obtained by subjecting a composition containing one or more components selected from the above to hydrolysis / dehydration condensation reaction.
Hereinafter, each component will be described.
(A) Proton conductive polymer As the proton conductive polymer (A),
The polymer is not particularly limited as long as it is a polymer having a proton acid group. The protonic acid group includes at least one selected from the group consisting of a sulfonic acid group, a carboxylic acid group, a phosphonic acid group, an alkylsulfonic acid group, an alkylcarboxylic acid group, an alkylphosphonic acid group, a phenolic hydroxyl group, and the like. preferable. More preferred are sulfonic acid, phosphonic acid and alkylsulfonic acid, and particularly preferred are sulfonic acid and alkylsulfonic acid. Proton conductivity is imparted by the proton acid group.

  Specific examples of the proton conductive polymer (A) include perfluoro protonic polymers such as perfluorosulfonic acid polymers and perfluorocarbon polymers having a carboxyl group and a sulfonic acid group. It is done. Further, polyether ketone, polyether ether ketone, polysulfide, polyphosphazene, polyarylene, polyphenylene, polybenzimidazole, polyethersulfone, polyetherethersulfone, polyphenylene oxide, polycarbonate, polyurethane, polyamide containing the above protonic acid group , Polyimide, polyurea, polysulfone, polysulfonate, polybenzimidazole, polybenzoxazole, polybenzothiazole, polythiazole, polyphenylquinoxaline, polyquinoline, polysiloxane, polytriazine, polydiene, polypyridine, polypyrimidine, polyoxathiazole, poly Tetrazapyrene, polyoxazole, polyvinyl pyridine, polyvinyl imidazole, polypyrrolidone, Li acrylate derivatives, polymethacrylate derivatives, may also be used such as a non-perfluorinated proton-conducting polymers such as polystyrene derivatives.

Among these, preferably, a perfluorosulfonic acid polymer, a perfluorocarbon polymer having a carboxyl group and a sulfonic acid group, a polyether ketone having a sulfonic acid or an alkyl sulfonic acid group, a polyether ether ketone, a polysulfide , Polyphosphazene, polyarylene, polyphenylene, polybenzimidazole, polyethersulfone, polyetherethersulfone, polyphenylene oxide, polycarbonate, polyimide, polysulfone, polysulfonate, polybenzimidazole, polybenzoxazole, polybenzothiazole, polythiazole, poly Phenylquinoxaline, polyquinoline, polysiloxane, polytriazine, polypyridine, polypyrimidine, polyoxathiazole, poly Torazapiren, polyoxazole, polyvinyl pyridine, polyvinyl imidazole, polypyrrolidone, polyacrylate derivatives, polymethacrylate derivatives, polystyrene derivatives.
More preferably, a perfluorosulfonic acid polymer, a perfluorocarbon-based resin having a carboxyl group and a sulfonic acid group, a polyether ketone having a sulfonic acid or alkylsulfonic acid group, a polyether ether ketone, a polysulfide, a polyphosphazene, a poly Arylene, polyphenylene, polybenzimidazole, polyethersulfone, polyetherethersulfone, polyphenylene oxide, polyimide, polysulfone, polysulfonate, polybenzimidazole, polybenzoxazole, polybenzothiazole, polythiazole, polyphenylquinoxaline, polyquinoline, polysiloxane And polytriazine.

  In the present invention, the proton conductive polymer (A) is preferably a polyarylene copolymer having a sulfonic acid group represented by the following general formula (1).

In the general formula (1), Y represents —CO—, —SO ₂ —, —SO—, —CONH—, —CO.
It represents at least one structure selected from the group consisting of O—, — (CF ₂ ) ₁ — (l is an integer of 1 to 10), and —C (CF ₃ ) ₂ —. Among, -CO -, - SO ₂ - is preferred.

Z is a direct bond or at least one selected from the group consisting of — (CH ₂ ) ₁ — (wherein 1 is an integer of 1 to 10), —C (CH ₃ ) ₂ —, —O—, and —S—. The structure of the species is shown. 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 ) _p SO ₃ H or —O (CF ₂ ) _p SO ₃ H (p 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. -SO ₃
At least one substituent represented by H or —O (CH ₂ ) _p SO ₃ H or —O (CF ₂ ) _p SO ₃ H (p represents an integer of 1 to 12) is substituted. In the case of a naphthyl group, it is preferable that two or more are substituted.
m is an integer of 0 to 10, preferably 0 to 2, n 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 m and n and the structures of Y, Z and Ar,
(1) a structure in which m = 0, n = 0, Y is —CO—, and Ar is a phenyl group having —SO ₃ H as a substituent;
(2) a structure in which m = 1, n = 0, Y is —CO—, Z is —O—, and Ar is a phenyl group having —SO ₃ H as a substituent;
(3) a structure in which m = 1, n = 1, k = 1, Y is —CO—, Z is —O—, and Ar is a phenyl group having —SO ₃ H as a substituent;
(4) a m = 1, n = 0, Y is -CO-, 2 pieces of -SO ₃ as Ar is a substituted group
A structure which is a naphthyl group having H,
(5) m = 1, n = 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.
More preferably, a polyarylene copolymer having a structure represented by the general formula (1) and a structure represented by the following general formula (2) is preferable.

In the general formula (2), A and D are independently a direct bond or —CO—, —SO ₂ —, —SO
-, - CONH -, - COO -, - (CF 2) l - (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 or a halogenated hydrocarbon group), a cyclohexylidene group, a fluorenylidene group, -O-, or -S- At least one structure is shown. Here, specific examples of the structure represented by —CR ′ ₂ — include a methyl group, an ethyl group, a propyl group,
Examples include isopropyl group, butyl group, isobutyl group, t-butyl group, propyl group, octyl group, decyl group, octadecyl group, phenyl group, trifluoromethyl group, and the like.

Among these, a direct bond, —CO—, —SO ₂ —, —CR ′ ₂ — (R ′ represents an aliphatic hydrocarbon group, an aromatic hydrocarbon group or a halogenated hydrocarbon group), cyclohexylidene Group, fluorenylidene group and -O- are preferred.
B is independently an oxygen atom or a sulfur atom, preferably an oxygen atom.

R ^{1 to} R ¹⁶ may be the same as or different from each other, and are a hydrogen atom, a fluorine atom, an alkyl group, a halogenated alkyl group in which a part or all of them are halogenated, an allyl group, an aryl group, a nitro group, a nitrile group. At least one atom or group selected from the group consisting of

  Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, an amyl group, a hexyl group, a cyclohexyl group, and an octyl group. Examples of the halogenated alkyl group include a trifluoromethyl group, a pentafluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, a perfluoropentyl group, and a perfluorohexyl group. Examples of the allyl group include a propenyl group, and examples of the aryl group include a phenyl group and a pentafluorophenyl group.

s and t represent an integer of 0 to 4. r shows 0 or an integer greater than or equal to 1, and an upper limit is 100 normally, Preferably it is 1-80. Preferred combinations of the values of s and t and the structures of A, B, D, and R ^{1 to} R ¹⁶ are as follows:
(1) s = 1, t = 1, A is —CR ′ ₂ — (R ′ represents an aliphatic hydrocarbon group, an aromatic hydrocarbon group and a halogenated hydrocarbon group), a cyclohexylidene group, A structure which is a fluorenylidene group, B is an oxygen atom, D is —CO— or —SO ₂ —, and R ^{1 to} R ¹⁶ are a hydrogen atom or a fluorine atom,
(2) a structure in which s = 1, t = 0, B is an oxygen atom, D is —CO— or —SO ₂ —, and R ^{1 to} R ¹⁶ are hydrogen atoms or fluorine atoms,
(3) s = 0, t = 1, A is —CR ′ ₂ — (R ′ represents an aliphatic hydrocarbon group, an aromatic hydrocarbon group and a halogenated hydrocarbon group), a cyclohexylidene group, Examples include a fluorenylidene group, B is an oxygen atom, and R ^{1 to} R ¹⁶ are a hydrogen atom, a fluorine atom, or a nitrile group.
(4) s = 1, t = 1, 2 and A is —C (CF ₃ ) ₂ — or —C (CR ′ ₂ ) ₂ — (R ′ is a hydrocarbon group or a cyclic hydrocarbon group). A structure in which B is an oxygen atom, and R ^{1 to} R ¹⁶ are a hydrogen atom or a fluorine atom,
(5) s = 0, t = 1, 2 and A is —C (CF ₃ ) ₂ — or —C (CR ′ ₂ ) ₂ — (R ′ is a hydrocarbon group or a cyclic hydrocarbon group). And a structure in which B is an oxygen atom, and R ^{1 to} R ¹⁶ are a hydrogen atom, a fluorine atom, or a nitrile group.

  The polyarylene copolymer having the structure represented by the general formula (1) and the structure represented by the general formula (2) is a polyarylene copolymer represented by the following general formula (3). Is mentioned.

In the general formula (3), A, B, D, Y, Z, Ar, k, m, n, r, s, t and R ^{1 to} R ¹⁶ are respectively in the general formulas (1) and (2). A, B, D, Y, Z, Ar, k
, M, n, r, s, t, and R ^{1 to} R ¹⁶ . x and y represent molar ratios when x + y = 100 mol%.

The polyarylene copolymer having a sulfonic acid group used in the present invention is 0.5 to 100 mol%, preferably 10 to 99.999 mol%, of the structural unit represented by the formula (1), that is, the unit of x. The structural unit represented by the formula (2), that is, the y unit is contained in an amount of 99.5 to 0 mol%, preferably 90 to 0.001 mol%.
For the production of the polyarylene copolymer having a sulfonic acid group, for example, the following three methods A, B, and C can be used.

(A1 method)
For example, in the method described in JP-A No. 2004-137444, a monomer having a sulfonate group that can be a structural unit represented by the general formula (1) and a structural unit represented by the general formula (2) A polyarylene having a sulfonic acid ester group is produced by copolymerization with a monomer or oligomer that can be synthesized, and the sulfonic acid ester group is deesterified, and then the sulfonic acid ester group is converted into a sulfonic acid group. be able to. (B1 method)
For example, in the method described in JP-A No. 2001-342241, a monomer having a skeleton represented by the general formula (1) and not having a sulfonic acid group or a sulfonic acid ester group, and the general formula (2) It is also possible to synthesize this polymer by copolymerizing a monomer or oligomer that can be a structural unit represented and sulfonating the polymer using a sulfonating agent.
(C1 method)
In the general formula (1), when Ar is an aromatic group having a substituent represented by —O (CH ₂ ) _p SO ₃ H or —O (CF ₂ ) _p SO ₃ H, for example, In the method described in Japanese Patent Application No. 2003-295974 (Japanese Patent Laid-Open No. 2005-60625), a precursor monomer that can be a structural unit represented by the above general formula (1) and the above general formula (2) It can also be synthesized by copolymerizing monomers or oligomers that can be structural units and then introducing alkylsulfonic acid or fluorine-substituted alkylsulfonic acid.

  Specific examples of the monomer having a sulfonate group that can be used in (Method A1) and can be the structural unit represented by the general formula (1) include sulfonate esters as shown below. Can do.

Specific examples of the monomer that does not have a sulfonic acid group or a sulfonic acid ester group that can be a structural unit represented by the general formula (I) that can be used in (Method B1) include sulfone as shown below. There may be mentioned acid esters.

Specific examples of the precursor monomer that can be used in (Method C1) and can be the structural unit represented by the general formula (1) include monomers as shown below.

Moreover, the following are mentioned as a specific example of the monomer or oligomer which can become a structural unit represented by the said General formula (2) used in any method.
When r = 0, for example, 4,4′-dichlorobenzophenone, 4,4′-dichlorobenzanilide, 2,2-bis (4-chlorophenyl) difluoromethane, 2,2-bis (4-chlorophenyl) -1, 1,1,3,3,3-hexafluoropropane, 4-chlorobenzoic acid-4-chlorophenyl ester, bis (4-chlorophenyl) sulfoxide, bis (4-chlorophenyl) sulfone, 2,6-dichlorobenzonitrile It is done. In these compounds, a compound in which a chlorine atom is replaced with a bromine atom or an iodine atom is exemplified.

In the case of r = 1, for example, compounds described in JP-A No. 2003-113136 can be exemplified.
In the case of r ≧ 2, for example, Japanese Patent Application Laid-Open No. 2004-137444, Japanese Patent Application Laid-Open No. 2004-244517, Japanese Patent Application No. 2003-143914 (Japanese Patent Application Laid-Open No. 2004-346164), Japanese Patent Application No. 2003
No. 348523 (Japanese Patent Laid-Open No. 2005-112985), Japanese Patent Application No. 2003-348524, Japanese Patent Application No. 20
Examples include compounds described in Japanese Patent Application No. 04-2111739 (Japanese Patent Laid-Open No. 2006-28414) and Japanese Patent Application No. 2004- 211740 (Japanese Patent Laid-Open No. 2006-28415).

  In order to obtain a polyarylene copolymer having a sulfonic acid group, first, a monomer that can be a structural unit represented by the general formula (1) and a structural unit represented by the general formula (2). It is necessary to obtain a precursor polyarylene by copolymerizing with a monomer or oligomer that can be 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, “salt” may be added.

Here, transition metal salts include nickel compounds such as nickel chloride, nickel bromide, nickel iodide and nickel acetylacetonate, palladium compounds such as palladium chloride, palladium bromide and palladium iodide, iron chloride and iron bromide. And iron compounds such as iron iodide and cobalt compounds such as cobalt chloride, cobalt bromide and cobalt iodide. Of these, nickel chloride, nickel bromide and the like are particularly preferable. As the ligand, triphenylphosphine, tri (2-methyl) phenylphosphine, tri (3-methyl) phenylphosphine, tri (4-methyl) phenylphosphine, 2,2′-bipyridine, 1
, 5-cyclooctadiene, 1,3-bis (diphenylphosphino) propane, etc., but triphenylphosphine, tri (2-methyl) phenylphosphine, 2,2 ′
-Bipyridine is preferred. The said ligand can be used individually by 1 type or in combination of 2 or more types.

Furthermore, as the transition metal (salt) in which the ligand is coordinated in advance, for example, nickel chloride bis (triphenylphosphine), nickel chloride bis (tri (2-methyl) phenylphosphine), nickel bromide bis (triphenyl) Phosphine), nickel iodide bis (triphenylphosphine), nickel nitrate bis (triphenylphosphine), nickel chloride (2,2′bipyridine), nickel bromide (2,2′bipyridine), nickel iodide (2,2) '
Bipyridine), nickel nitrate (2,2′bipyridine), bis (1,5-cyclooctadiene) nickel, tetrakis (triphenylphosphine) nickel, tetrakis (triphenylphosphite) nickel, tetrakis (triphenylphosphine) palladium, etc. Among them, nickel chloride bis (triphenylphosphine), nickel chloride bis (tri (2-methyl) phenylphosphine), and nickel chloride (2,2′bipyridine) are preferable.

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

  “Salts” that can be used in the catalyst system of the present invention include sodium compounds such as sodium fluoride, sodium chloride, sodium bromide, sodium iodide, sodium sulfate, potassium fluoride, potassium chloride, bromide. Examples include potassium compounds such as potassium, potassium iodide, and potassium sulfate, and ammonium compounds such as tetraethylammonium fluoride, tetraethylammonium chloride, tetraethylammonium bromide, tetraethylammonium iodide, and tetraethylammonium sulfate. Sodium iodide, potassium bromide, tetraethylammonium bromide and tetraethylammonium iodide are preferred.

  The proportion of each component used in the catalyst system is such that the transition metal salt or the transition metal (salt) coordinated with the ligand can be a structure represented by the above general formula (1), the monomer precursor, It is usually 0.0001 to 10 mol, preferably 0.01 to 0.5 mol, based on 1 mol of the total of the monomers or oligomer precursors that can be the structural unit represented by 2). When the amount is less than 0.0001 mol, the polymerization reaction does not proceed sufficiently. On the other hand, when the amount exceeds 10 mol, the molecular weight is lowered. In the catalyst system, when a transition metal salt and a ligand are used, the proportion of the ligand used is usually 0.1 to 100 mol, preferably 1 to 10 mol, per 1 mol of the transition metal salt. If the amount is less than 0.1 mol, the catalytic activity becomes insufficient. On the other hand, if the amount exceeds 100 mol, the molecular weight decreases.

  The ratio of the reducing agent used in the catalyst system is such that the monomer precursor that can be a structure represented by the above general formula (1), the monomer that can be the structural unit represented by the above general formula (2), or an oligomer precursor The total amount is generally 0.1 to 100 mol, preferably 1 to 10 mol. When the amount is less than 0.1 mol, the polymerization does not proceed sufficiently. On the other hand, when the amount exceeds 100 mol, there is a problem that it is difficult to purify the resulting polymer.

  Furthermore, when “salt” is used in the catalyst system, the proportion used is a monomer precursor that can be a structure represented by the above general formula (1), and a monomer that can be a structural unit represented by the above general formula (2). Or, it is usually 0.001 to 100 mol, preferably 0.01 to 1 mol, per 1 mol of the total of oligomer precursors. When the amount is less than 0.001 mol, the effect of increasing the polymerization rate is insufficient. On the other hand, when the amount exceeds 100 mol, there is a problem that it is difficult to purify the resulting polymer.

  Examples of the polymerization solvent that can be used in the present invention include tetrahydrofuran, cyclohexanone, dimethyl sulfoxide, N, N-dimethylformamide, N, N-dimethylacetamide, 1-methyl-2-pyrrolidone, γ-butyrolactone, γ- Examples include butyrolactam, and tetrahydrofuran, N, N-dimethylformamide, N, N-dimethylacetamide, and 1-methyl-2-pyrrolidone are preferable. These polymerization solvents are preferably used after sufficiently dried. In the polymerization solvent, the total concentration of the monomer precursor that can be a structure represented by the general formula (2), the monomer that can be a structural unit represented by the general formula (2), or the precursor of the oligomer is usually, 1 to 90% by weight, preferably 5 to 40% by weight.

  Moreover, the polymerization temperature at the time of superposing | polymerizing the polymer of this invention is 0-200 degreeC normally, Preferably it is 50-80 degreeC. The polymerization time is usually 0.5 to 100 hours, preferably 1 to 40 hours.

A polyarylene copolymer having a sulfonic acid group can be obtained by converting the polyarylene of the precursor into a polyarylene having a sulfonic acid group. As this method, there are the following three methods.
(Method A2) A method in which polyarylene having a sulfonate group as a precursor is deesterified by the method described in JP-A-2004-137444.
(Method B2) A method of sulfonating a precursor polyarylene by the method described in JP-A-2001-342241.
(Method C2) A method of introducing an alkylsulfonic acid group into the precursor polyarylene by the method described in Japanese Patent Application No. 2003-295974 (Japanese Patent Laid-Open No. 2005-60625).

(Method A2)
In this method, a sulfonic acid ester group (—SO 3 R) is converted into a sulfonic acid group (—SO 3 H) by hydrolysis.
In particular,
(1) A method in which the polyarylene is added to an excess amount of water or alcohol containing a small amount of hydrochloric acid and stirred for 5 minutes or more. (2) The polyarylene is heated at a temperature of about 80 to 120 ° C. in trifluoroacetic acid. Method of reacting for about 10 hours (3) In a solution containing 1 to 5 moles of lithium bromide per mole of sulfonic acid ester group (—SO 3 R) in polyarylene, for example, in a solution such as N-methylpyrrolidone Examples include a method of reacting polyarylene for about 3 to 10 hours at a temperature of about 80 to 150 ° C. and then adding hydrochloric acid (Method B2).
Sulfonating precursor polyarylene without sulfonic acid group or sulfonic acid ester group under known conditions using known sulfonating agents such as sulfuric anhydride, fuming sulfuric acid, chlorosulfonic acid, sulfuric acid, sodium hydrogen sulfite [Polymer Preprints, Japan, Vol. 42, no. 3, p. 730 (1993); Polymer Preprints, Japan, Vol. 42, no. 3, p. 736 (1994); Polymer Preprints, Japan, Vol. 42, no. 7, p. 2490-2492 (1993)]. That is, as the reaction conditions for the sulfonation, a precursor polyarylene having no sulfonic acid group or sulfonic acid ester group is reacted with the sulfonating agent in the absence of a solvent or in the presence of a solvent. Examples of the solvent include hydrocarbon solvents such as n-hexane, ether solvents such as tetrahydrofuran and dioxane, aprotic polar solvents such as dimethylacetamide, dimethylformamide, and dimethylsulfoxide, tetrachloroethane, dichloroethane, chloroform, and chloride. And halogenated hydrocarbons such as methylene. The reaction temperature is not particularly limited, but is usually −50 to 200 ° C., preferably −10 to 100 ° C. The reaction time is usually 0.5 to 1,000 hours, preferably 1 to 200 hours (Method C2):
By copolymerizing the monomers shown in the above (Method C1) with a monomer or oligomer that can be the structural unit represented by the general formula (2), an —OM group or an —SM group (M is a hydrogen atom or After obtaining a precursor polyarylene having an alkali metal atom), it can be sulfonated by reacting the compound represented by the following general formula (4) or (5) under alkaline conditions.

In the formula (4), R ⁴⁰ represents at least one atom or group selected from the group consisting of a hydrogen atom, a fluorine atom, an alkyl group, and a fluorine-substituted alkyl group, and g represents an integer of 1 to 20.

In formula (5), L represents any of a chlorine atom, a bromine atom, and an iodine atom, and M represents a hydrogen atom or an alkali metal atom. R ^40, g has the same meaning as R ^40, g in the formula (4).
Specific examples of the compound represented by the general formula (4) include the following compounds.

  Specific examples of the compound represented by the general formula (5) include the following compounds.

  When reacting with the general formula (4) or (5) under alkaline conditions, the precursor polyarylene may be dissolved, for example, N-methyl-2-pyrrolidone, N, N-dimethylacetamide, sulfolane, diphenyl sulfone. And polar solvents having a high dielectric constant such as dimethyl sulfoxide.

When M is a hydrogen atom, an alkali metal salt can be obtained by adding an alkali metal, an alkali metal hydride, an alkali metal carbonate or the like as required.
Examples of the alkali metal include lithium, sodium, and potassium, and examples of the alkali metal hydride, alkali metal hydroxide, and alkali metal carbonate include the alkali metal hydride, hydroxide, and carbonate, respectively. . Usually, the alkali metal is reacted in excess with respect to the -OM group or -SM group in the precursor polyarylene, and usually 1.1 to 4 times equivalent of the -OM group or -SM group is used. Preferably, 1.2 to 3 times equivalent is used.

  The ion exchange capacity is, for example, a precursor monomer that can be a structural unit represented by the general formula (1), a monomer that can be a structural unit represented by the general formula (2), or the type of oligomer or the proportion of use. It can be adjusted by changing the combination.

The molecular weight of the polyarylene copolymer thus obtained is 10,000 to 1,000,000, preferably 20,000 to 800,000 in terms of polystyrene-equivalent weight average molecular weight by gel permeation chromatography (GPC).
The ion exchange capacity of the proton conductive material having a protonic acid group is usually 0.3 to 5 meq / g, preferably 0.5 to 4 meq / g, and more preferably 0.8 to 3 meq / g. If it is less than 0.3 meq / g, the proton conductivity is low and the power generation performance is low. On the other hand, if it exceeds 5 meq / g, the water resistance may be significantly lowered.
Ingredient (B)
Component (B) is a reaction obtained by subjecting a composition containing components (Ba) and (Bb) described below to hydrolysis / dehydration condensation reaction (hereinafter referred to as “hydrolysis condensation reaction”). It is a thing. The component (B) contains, in addition to the components (Ba) and (Bb), one or more components selected from the components (Bc) and (Bd) described below. A reaction product obtained by subjecting a product to a hydrolytic condensation reaction is preferred.
Ingredient (Ba)
The component (Ba) is a compound represented by the following formula (6).
Si (OR ²⁰ ) _E (R ²¹ ) _F (R ²² ) _G (6)
In the formula, E is 2 to 3, F is 0 to 1, G is 1 to 2, and E + F + G = 4. R ²⁰ and R ²¹ are a hydrogen atom or an optionally halogenated hydrocarbon group. R ²² is an optionally halogenated hydrocarbon group having a nitrogen-containing heterocyclic structure or an optionally substituted amino group.

  The component (Ba) has a nitrogen-containing heterocyclic structure or a hydrocarbon group having an optionally substituted amino group, and thus has excellent compatibility with the component (A), and has a uniform high A molecular electrolyte can be obtained.

The hydrocarbon group that can be taken by R ²⁰ , R ²¹ or R ^{22 in the} above formula (6) may be any of an aliphatic group, an alicyclic group, and an aromatic group. Such a hydrocarbon group is preferably a hydrocarbon group having 1 to 24 carbon atoms, more preferably 1 to 10 carbon atoms. When the number of carbon atoms exceeds 24, the metal alkoxide is excessively stable and the reactivity becomes poor.

  Specific examples of these hydrocarbon groups include methyl, ethyl, n-propyl, iso-propyl, sec-propyl, butyl, iso-butyl, sec-butyl, tert-butyl. Group, amyl group, hexyl group, cyclopentyl group, cyclohexyl group, octyl group, decyl group, dodecyl group, phenyl group, naphthyl group, glycidoxypropyl group, epoxycyclohexylethyl group, vinyl group, allyl group, methacryloxypropyl group Etc. Preferred are methyl group, ethyl group, n-propyl group, iso-propyl group, butyl group, iso-butyl group, hexyl group, cyclopentyl group, cyclohexyl group, octyl group, decyl group, dodecyl group and phenyl group. More preferably, they are a methyl group, an ethyl group, and a phenyl group.

  Examples of the halogenated hydrocarbon group include trifluoromethyl group, trifluoropropyl group, pentafluoroethyl group, perfluoropropyl group, perfluorobutyl group, perfluoropentyl group, perfluorohexyl group, perfluorophenyl group, Examples include perfluorobiphenyl groups. Preferably, it is a trifluoropropyl group.

Examples of the nitrogen-containing heterocyclic structure that can be taken by R ²² in the above formula (6) include a pyrrole group, a thiazole group, a benzothiazole group, an isothiazole group, an oxazole group, a benzoxazole group, an isoxazole group, an imidazole group, and an imidazoline group. , Imidazolidine group, benzimidazole group, pyrazole group, triazine group, pyridine group, pyrimidine group, pyridazine group, pyrazine group, indole group, quinoline group, isoquinoline group, bromine group, tetrazole group, tetrazine group, triazole group, carbazole group , Acridine group, quinoxaline group, quinazoline group, indolizine group, isoindole group, 3H-indole group, 2H-pyrrole group, 1H-indazole group, purine group, phthalazine group, naphthyridine group, cinnoline group, pteridine group, carboline group , Phenanthri Gin group, perimidine group, phenanthroline group, phenazine group, phenalsazine group, phenothiazine group, furazane group, phenoxazine group, pyrrolidine group, pyrroline group, pyrazoline group, pyrazolidine group, piperidine group, piperazine group, indoline group, isoindoline group, An example is a quinuclidine group.
Of these, an imidazole group, an imidazoline group, a pyridine group, a pyrrole group, a benzimidazole group, a benzoxazole group, a triazine group, and a triazole group are more preferable.

Examples of the substituent amino group that R ²² in formula (6) can take include a methyl group, an ethyl group, and n-
Propyl, iso-propyl, tert-butyl, iso-butyl, n-butyl, se
c-butyl group, octyl group, neopentyl group, cyclopentyl group, hexyl group, cyclohexyl group, cyclopentylmethyl group, cyclohexylmethyl group, adamantyl group, adamantanemethyl group, 2-ethylhexyl group, bicyclo [2.2.1] heptyl Group, bicyclo [2.2.1] heptylmethyl group, tetrahydrofurfuryl group, 2-methylbutyl group, 3,3
-Linear hydrocarbon group such as dimethyl-2,4-dioxolanemethyl group, cyclohexylmethyl group, adamantylmethyl group, bicyclo [2.2.1] heptylmethyl group, allyl group, 2-hydroxyethyl group, etc. Examples include hydrocarbon groups, alicyclic hydrocarbon groups, hydrocarbon groups having 5-membered heterocycles, and aromatic ring groups such as phenyl groups, naphthyl groups, and toluyl groups. Among these, methyl groups, ethyl groups, n-propyl group, iso-propyl group, tert-butyl group, iso-
Amino group substituted by butyl group, n-butyl group, sec-butyl group, cyclohexyl group, phenyl group, 2-aminoethyl group, 6-aminohexyl group, amino (polypropyleneoxy) group, ureido group, An isocyanate group etc. are mentioned.

  Specific examples of the component (Ba) include the following compounds.

Moreover, the compound etc. in which the methoxy group couple | bonded with Si in the said compound replaced the ethoxy group, propoxy group, butyroxy group, and iso-propoxy group are mentioned.
Ingredient (Bb)
The component (Bb) is a compound represented by the following general formula (7).

In the formula (7), E ′ is 2 to 3, F ′ is 0 to 1, G ′ is 1 to 2, and E ′ + F ′ + G ′ = 4. In the formula, R ³⁰ and R ³¹ are a hydrogen atom or an optionally halogenated hydrocarbon group. R ³² is
An optionally halogenated hydrocarbon group having a proton acid group.

The component (Bb) has an optionally halogenated hydrocarbon group having a protonic acid group, unlike the component (Ba). Proton conductivity can be improved by having a proton acid group.
Addition of component (Bb) improves proton conductivity while maintaining dimensional stability compared to inorganic components consisting of components (Ba), (Bc) and (Bd) It can be made.

  The protonic acid group includes at least one selected from the group consisting of a sulfonic acid group, a carboxylic acid group, a phosphonic acid group, an alkylsulfonic acid group, an alkylcarboxylic acid group, an alkylphosphonic acid group, a phenolic hydroxyl group, and the like. preferable. More preferred are sulfonic acid, phosphonic acid and alkylsulfonic acid, and particularly preferred are sulfonic acid and alkylsulfonic acid. Proton conductivity is imparted by the proton acid group. The proton acid group may be in the form of an alkali metal salt such as lithium, sodium, or potassium.

The hydrocarbon group which R ³⁰ or R ³¹ or R ^{32 in the} above formula (7) can take is the same as the hydrocarbon group which R ²⁰ , R ²¹ or R ^{22 in} the above formula (6) can take. The hydrocarbon group in formula (7) and the hydrocarbon group in formula (6) may be the same or different.

  Specific examples of the component (Bb) include the following compounds.

A metal alkoxide having a proton acid group can also be synthesized by sulfonating a metal alkoxide having no proton acid group (hereinafter, also referred to as a precursor metal alkoxide) under known conditions [Biomacromolecules, Vol. 6, no. 1,
368-373 (2005)]. That is, it is reacted with a known sulfonating agent such as sulfuric anhydride, fuming sulfuric acid, chlorosulfonic acid, sulfuric acid, sodium hydrogen sulfite or the like in the absence of a solvent or in the presence of a solvent. Examples of the solvent include hydrocarbon solvents such as n-hexane, ether solvents such as tetrahydrofuran and dioxane, aprotic polar solvents such as dimethylacetamide, dimethylformamide, and dimethylsulfoxide, tetrachloroethane, dichloroethane, chloroform, and chloride. And halogenated hydrocarbons such as methylene. The reaction temperature is not particularly limited, but is usually −50 to 200 ° C., preferably −10 to 100 ° C. The reaction time is usually 0.5 to 1,000 hours, preferably 1 to 200 hours. Specific examples of the precursor metal alkoxide include the following compounds.

  Examples of metal alkoxides obtained by sulfonation are as follows.

Ingredient (Bc)
The component (Bc) is a compound represented by the following formula (8) other than the components (Ba) and (Bb).

Si (OR ⁴⁰ ) _e (R ⁴¹ ) _f (8)
In the formula (8), e is 2 to 4, f is 0 to 2, and e + f = 4. R ⁴⁰ and R ⁴¹ are a hydrogen atom or an optionally halogenated hydrocarbon group.

  Component (Bc) is different from Component (Ba) and Component (Bb) in that it contains a nitrogen-containing heterocyclic structure and an optionally substituted amino group or a hydrocarbon group having a protonic acid group. I don't have it. Component (Bc) is an inorganic component having a heterocyclic compound containing nitrogen that can interact with a protonic acid group, an amino group, or a substituent amino group from the viewpoint of film properties such as proton conductivity and dimensional stability. It is added to control the component amount of Ba), the component amount of the inorganic component (Bb) having a protonic acid group capable of improving the proton conductivity, and the component amount of the metal oxide (Bd). .

The hydrocarbon group which R ⁴⁰ or R ⁴¹ in the above formula (8) can take is the same as the hydrocarbon group which R ²⁰ , R ²¹ or R ^{22 in} the above formula (6) can take. The hydrocarbon group in formula (8) and the hydrocarbon group in formula (6) may be the same or different.

  Specific examples of the component (Bc) include the following compounds.

Moreover, the compound etc. in which the methoxy group couple | bonded with Si in the said compound replaced the ethoxy group, propoxy group, butyroxy group, and iso-propoxy group are mentioned.
Of these, tetramethoxysilane (TMOS), tetraethoxylane (TEOS), methyltriethoxysilane, ethyltriethoxysilane, and phenyltriethoxysilane are particularly preferable.
Ingredient (Bd)
Component (Bd) is an alkoxide of Al, Ti, or Zr. Addition of the component (Bd) makes it possible to improve (decrease in the case of membrane resistance) the proton conductivity of the polymer electrolyte membrane obtained from the polymer electrolyte of the present invention. In addition, when only the component (Ba) is added to the proton conductive polymer of the component (A), the proton conductivity may be reduced. However, the addition of the component (Bd) reduces such adverse effects. Thus, a polymer electrolyte membrane excellent in proton conductivity can be obtained.

The alkoxide group of component (Bd) may be either linear or branched, and is preferably an alkoxide group having 1 to 24 carbon atoms, more preferably 1 to 10 carbon atoms. When the number of carbon atoms exceeds 24, the metal alkoxide becomes excessively stable and the reactivity becomes poor. Specific examples of such alkoxide groups include, for example, methyl group, ethyl group, propyl group, butyl group, iso-propyl group, iso-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group, 2-ethylhexyl group, t-octyl group, decyl group, dodecyl group, tetradecyl group, 2-hexyldecyl group, hexadecyl group, octadecyl group, cyclohexylmethyl group, octylcyclohexyl group and the like. Among these, a methyl group, an ethyl group, a propyl group, a butyl group, an iso-propyl group, and an iso-butyl group are preferable.
Specific examples of component (Bd) include aluminum tri-n-butoxide, aluminum tri-sec-butoxide, aluminum tri-tert-butoxide, aluminum trimethoxide, aluminum triethoxide, aluminum tri-iso-propoxide, etc. Aluminum alkoxide, titanium tetraethoxide, titanium tetra-iso-propoxide, titanium tetra-n-butoxide, titanium tetra-tert-butoxide, chlorotitanium tri-iso-propoxide, etc., titanium alkoxide, zirconium tetra-n-butoxide And zirconium alkoxides such as zirconium tetra-tert-butoxide, zirconium tetra-iso-propoxide and zirconium tetraethoxide. It is.

Among these, titanium tetraethoxide, titanium tetra-iso-propoxide, titanium tetra-n-butoxide, and titanium tetra-tert-butoxide are preferable.
Compounding ratio of the amount component of the components (B-a) ~ (B -d) as 100 mol% of the total amount of (B-a) ~ (B -d) component is (B-a) 1 -99 mol% is good, More preferably, it is 5-95 mol%, More preferably, it is 10-90 mol%, (Bb) is 1-99 mol% good, More preferably, it is 5-95 mol%, More preferably, it is 10- 90 mol%, (Bc) is 0 to 95 mol%, more preferably 0 to 90 mol%, still more preferably 0 to 85 mol%, and (Bd) is 0 to 50 mol%, more Preferably it is 0-45 mol%, More preferably, it is 0-40 mol%.
Production Method of Polymer Electrolyte A polymer electrolyte can be produced by the following (Method A) and (Method B).

  (Method A) After stirring in a solvent to mix each raw material component for preparing the component (B), water is added to cause a hydrolytic condensation reaction to produce a hydrolytic condensate (hereinafter referred to as “sol solution”). "). On the other hand, this is a method for preparing a polymer electrolyte by preparing a solution (hereinafter also referred to as a polymer solution) in which the component (A) is dissolved, and mixing the sol solution and the polymer solution.

(Method B) In this method, each raw material component for preparing the component (B) is mixed in a polymer solution composed of the component (A), and then water is added to carry out a hydrolytic condensation reaction to produce a polymer electrolyte. .
(Method A) will be described in detail below.
Sol Sol Preparation Method (B) The solvent for dissolving each raw material component for preparing the component is not particularly limited as long as it dissolves, but is preferably a carbonate compound (ethylene carbonate, propylene carbonate, etc.), a heterocyclic ring. Compounds (3-methyl-2-oxazolidinone, N-methylpyrrolidone, etc.), cyclic ethers (dioxane, tetrahydrofuran, etc.), chain ethers (diethyl ether, ethylene glycol dialkyl ether, propylene glycol dialkyl ether, polyethylene glycol dialkyl ether, Polypropylene glycol dialkyl ether, etc.), alcohols (methanol, ethanol, isopropanol, ethylene glycol monoalkyl ether, propylene glycol monoalkyl ether, polyethylene) Glycol monoalkyl ether, polypropylene glycol monoalkyl ether, etc.), polyhydric alcohols (ethylene glycol, propylene glycol, polyethylene glycol, polypropylene glycol, glycerin, etc.), nitrile compounds (acetonitrile, glutaronitrile, methoxyacetonitrile, propionitrile, Benzonitrile, etc.), esters (carboxylic acid ester, phosphoric acid ester, phosphonic acid ester, etc.), aprotic polar substances (dimethyl sulfoxide, sulfolane, dimethylformamide, dimethylacetamide, etc.), nonpolar solvents (toluene, xylene, etc.), Chlorine solvents (methylene chloride, ethylene chloride, etc.) can be used.

Among these, alcohols such as methanol, ethanol, isopropanol, heterocyclic compounds (3-methyl-2-oxazolidinone, N-methylpyrrolidone, etc.), aprotic polar substances (dimethyl sulfoxide, sulfolane, dimethylformamide, dimethylacetamide, etc.), etc. Is preferred.
These may be used alone or in combination of two or more. The amount of the solvent is preferably 0 to 95% by mass, more preferably 5 to 95% by mass with respect to the metal alkoxide.

  For the purpose of controlling the reactivity of the precursor in the hydrolysis condensation reaction, a stabilizer capable of chelating with a metal atom may be used. Examples of the stabilizer include acetoacetic esters (such as ethyl acetoacetate), 1,3-diketones (such as acetylacetone), and acetoacetamides (such as N, N-dimethylaminoacetoacetamide). Of these, acetylacetone is preferred.

  When these stabilizers are used, the amount used is not particularly limited as long as it does not affect the sol-gel reaction, but is 0.01 to 2 equivalents with respect to the metal alkoxide (the metal in it). Is more preferable, and 0.01 to 1 equivalent is more preferable. If it exceeds 2 equivalents, the sol-gel reaction tends to be slow.

  Furthermore, a catalyst comprising an acid or a base can be used as a catalyst for controlling the hydrolysis condensation reaction. As the alkali base catalyst, alkali metal hydroxide such as sodium hydroxide, ammonia and the like are generally used. An inorganic or organic proton acid can be used as the acid catalyst. Examples of the inorganic protonic acid include hydrochloric acid, sulfuric acid, boric acid, nitric acid, perchloric acid, tetrafluoroboric acid, hexafluoroarsenic acid, hydrobromic acid and the like. Examples of the organic protonic acid include acetic acid, oxalic acid, methanesulfonic acid, benzenesulfonic acid, maleic acid and the like. Among these, hydrochloric acid, sulfuric acid, benzenesulfonic acid, and maleic acid are preferable. The catalyst is added in an amount of 0.01 to 20 mol%, preferably 0.02 to 10 mol%, when the total metal alkoxide is 100 mol%. It is good to add. If the amount of the catalyst is too large, the reaction rate of the hydrolysis and dehydration condensation reaction is fast and difficult to control, and if it is too small, the reaction may not proceed sufficiently.

  The amount of water added is desirably in the range of 0.1 to 3 and preferably in the range of 0.2 to 2.5 in terms of molar ratio with respect to the total alkoxy groups. If the amount of water is too large, the reaction rate of hydrolysis and dehydration condensation reaction is fast and difficult to control, and if it is too small, the reaction may not proceed sufficiently.

  The hydrolysis and dehydration condensation reaction is usually performed in the range of 0 to 100 ° C, preferably 10 to 70 ° C, more preferably 20 to 60 ° C. If the reaction temperature is too high, the reaction rate of the hydrolysis and dehydration condensation reaction is fast and difficult to control, and if too low, the reaction may not proceed sufficiently.

Further, pressure may be applied during the reaction, usually 1 to 5 atm (0.101 to 0.505 MPa).
), More preferably in the range of 1 to 3 atmospheres (0.101 to 0.303 MPa).
After hydrolysis and dehydration condensation of the precursor, the solvent of the reacted sol solution may be concentrated and replaced with a solvent different from the solvent used during the reaction. The solvent to be substituted is preferably the same as that used for the polymer solution described later. By using such a solvent, the sol solution can be uniformly dispersed in the polymer solution.
The concentration of the reaction product obtained by hydrolysis / dehydration condensation reaction of the components (Ba) and (BB) in the sol solution is usually 5 to 75% by mass, preferably 7 to 55% by mass. . Further, the concentration of the reaction product obtained by the hydrolysis / dehydration condensation reaction in which components (Bc) and (Bd) are further added is the same as described above.
Method for preparing polymer solution The solvent for dissolving the component (A) is not particularly limited as long as it dissolves. For example, N-methyl-2-pyrrolidone, N, N-dimethylformamide, γ-butyrolactone, N , N-dimethylacetamide, dimethyl sulfoxide, dimethylurea, dimethylimidazolidinone, acetonitrile and other aprotic polar solvents, dichloromethane, chloroform, 1,2-dichloroethane, chlorinated solvents such as chlorobenzene and dichlorobenzene, methanol, ethanol , Alcohols such as propanol, iso-propyl alcohol, sec-butyl alcohol, tert-butyl alcohol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monoethyl ether Alkylene glycol monoalkyl ethers, acetone, methyl ethyl ketone, cyclohexanone, ketones such as γ- butyrolactone, tetrahydrofuran, ethers 1,3-dioxane and the like. These solvents can be used alone or in combination of two or more. In particular, N-methyl-2-pyrrolidone (hereinafter also referred to as “NMP”) is preferable in terms of solubility and solution viscosity.

  When two or more kinds of mixed solvents are used, it is desirable to use a mixture of an aprotic polar solvent and another solvent, and the composition of the mixed solvent is 95 to 25% by mass of the aprotic polar solvent, preferably 90 to 25% by mass and other solvents are 5 to 75% by mass, preferably 10 to 75% by mass (however, the total is 100% by mass). When the amount of the other solvent is within the above range, the effect of lowering the solution viscosity is excellent. As a combination of the aprotic polar solvent and the other solvent in this case, NMP is preferable as the aprotic polar solvent, and methanol having an effect of lowering the solution viscosity in a wide composition range is preferable as the other solvent.

The density | concentration of the component (A) in a polymer solution is 5-40 mass% normally, Preferably it is 7-25 mass%.
The viscosity of the polymer solution depends on the molecular weight of the proton conductive material having a proton acid group, the polymer concentration, and the concentration of the additive, but is usually 1,000 to 100,000 mPa · s, preferably 2, 000 to 50,000 mPa · s. If the viscosity is too high, mixing with the sol solution may be difficult.

  By mixing the sol solution and the polymer solution, a polymer electrolyte for a direct methanol fuel cell can be obtained. Among these, when using with powder, it can manufacture by distilling a solvent further from the mixed state. Moreover, when using as a film | membrane, it can manufacture by the casting method etc. which shape | mold into a film form as mentioned later.

The ion exchange capacity of the polymer electrolyte is usually 0.1 to 4.5 meq / g, preferably 0.3 to 3.5 meq / g, and more preferably 0.5 to 3.0 meq / g.
Next, (Method B) will be described in detail below.

In (Method B), each raw material component for preparing the component (B) is mixed in a polymer solution composed of the component (A), and then water is added to perform a hydrolysis / dehydration condensation reaction. Alternatively, each precursor may be dissolved in a soluble solvent and then dissolved in the polymer solution. Examples of the solvent to be used include the solvents exemplified in the preparation of the sol solution in the above (Method A).
The polymer solution and other components used in Method B are the same as in Method A.

(Method A) The polymer electrolyte for a direct methanol fuel cell obtained by (Method B) has a structure in which the component (B) is dispersed in the component (A).
The total amount of the components (B-a) and (B-b) in the electrolyte is 1 to 1% with respect to 100% by mass of the total amount of the components (A) and (B-a) and (B-b). 50 mass%, preferably 5-45 mass% is more preferably 10-40 mass%. In addition, when (Bc) alone or (Bc) and (Bd) components are added, the total amount of (Ba) to (Bd) components is A range similar to the above is preferable with respect to 100% by mass of the total amount of the components (Ba) to (Bd).
[Manufacture of polymer electrolyte membranes]
The polymer electrolyte for a direct methanol fuel cell according to the present invention includes an electrolyte for a primary battery, an electrolyte for a secondary battery, a solid polymer electrolyte for a fuel cell, a display element, various sensors, a signal transmission medium, a solid capacitor, an ion exchange membrane, and the like. It can be used in a film state, a solution state, and a powder state. Among these usage modes, a membrane state and a solution state are preferable (hereinafter, the membrane state is referred to as a polymer electrolyte membrane).

The polymer electrolyte membrane can be produced by a casting method in which the polymer electrolyte is cast on a substrate and formed into a film shape.
In the case of forming a film by the casting method, the electrolyte is in a solution state, and the concentration of the total solid content consisting of the reaction product obtained by hydrolytic condensation of components (A) and (Ba) to (Bd) at that time Is usually 5 to 40% by mass, preferably 7 to 25% by mass. If it is less than 5% by mass, it is difficult to increase the thickness during film formation, and pinholes are likely to be generated. On the other hand, if it exceeds 40% by mass, the solution viscosity is too high to form a film, and surface smoothness may be lacking.
Further, the total amount of the components (Ba) to (Bd) in the electrolyte membrane is 100% by mass with respect to the total amount of the components (A) and (Ba) to (Bd). 1-50 mass%, Preferably 5-45 mass% is still more preferably 10-40 mass%. When the total amount of components (Ba) to (Bd) is within the above range, the proton conductivity, methanol permeability, and dimensional stability in aqueous methanol solution of the electrolyte membrane are excellent.

The substrate is not particularly limited as long as it is a substrate used in an ordinary solution casting method. For example, a substrate made of plastic or metal is used, and preferably made of a thermoplastic resin such as a polyethylene terephthalate (PET) film. A substrate is used.
When the obtained undried film is immersed in water after film formation, the organic solvent in the undried film can be replaced with water, and the amount of residual solvent in the resulting polymer electrolyte membrane can be reduced.
In addition, after film formation, before immersing an undried film in water, you may predry an undried film. The preliminary drying is performed by holding the undried film at a temperature of usually 50 to 150 ° C. for 0.1 to 10 hours.
When immersing an undried film (including a pre-dried film; the same shall apply hereinafter) in water, a batch method in which a single wafer is immersed in water may be used, and a film is formed on a substrate film (for example, PET). A continuous method may be used in which the laminated film is left as it is, or a film separated from the substrate is immersed in water and wound. Moreover, in the case of a batch system, in order to suppress wrinkles from being formed on the film surface after the treatment, it is desirable to immerse the film in water by a method such as placing an undried film on a frame.

The amount of water used when the undried film is immersed in water is 10 parts by weight or more, preferably 30 parts by weight or more, more preferably 50 parts by weight or more with respect to 1 part by weight of the undried film. If the usage-amount of water is the said range, the residual solvent amount of the polymer electrolyte membrane obtained can be decreased. In addition, it is possible to reduce the amount of residual solvent in the resulting polymer electrolyte membrane by changing the water used for immersion or overflowing it so that the organic solvent concentration in the water is always kept below a certain level. It is effective for. Furthermore, in order to suppress the in-plane distribution of the amount of the organic solvent remaining in the polymer electrolyte membrane, it is effective to homogenize the concentration of the organic solvent in water by stirring or the like.
The temperature of water when the undried film is immersed in water is usually in the range of 5 to 80 ° C., preferably 10 to 60 ° C., from the viewpoint of the replacement speed and ease of handling. When the water temperature is high, the replacement rate of the organic solvent and water increases, but the water absorption of the film also increases, so that the surface state of the polymer electrolyte membrane obtained after drying may deteriorate. If the water temperature is low, the replacement rate is low and the cooling is not efficient.

Further, the immersion time of the film is usually in the range of 10 minutes to 240 hours, preferably 30 minutes to 100 hours, although it depends on the initial residual solvent amount, the amount of water used and the treatment temperature.
When the undried film is immersed in water and dried as described above, a film with a reduced amount of residual solvent is obtained. The amount of residual solvent in the film thus obtained is usually 5% by mass or less. Further, depending on the immersion conditions, the amount of residual solvent in the obtained film can be set to 1% by mass or less. As such conditions, for example, the amount of water used relative to 1 part by weight of the undried film is 50 parts by weight or more, the temperature of the water when immersed is 10 to 60 ° C., and the immersion time is 10 minutes to 10 hours. is there.

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

In addition, when producing polymer electrolyte membranes, inorganic proton conduction such as inorganic acids such as sulfuric acid and phosphoric acid, phosphate glass, tungstic acid, phosphate hydrate, β-alumina proton substitution products, proton-introduced oxides, etc. Body particles, an organic acid containing a carboxylic acid, an organic acid containing a sulfonic acid, an organic acid containing a phosphonic acid, an appropriate amount of water, and the like may be used in combination.
The polymer electrolyte membrane obtained as described above has a dry film thickness of usually 10 to 100 μm, preferably 15 to 80 μm.

The ion exchange capacity of the polymer electrolyte membrane is usually 0.1 to 4.5 meq / g, preferably 0.3 to 3.5 meq / g, more preferably 0.5 to 3.0 meq / g. If it is less than 0.1 meq / g, the proton conductivity is low and the power generation performance is low. On the other hand, if it exceeds 5 meq / g, the water resistance may be significantly lowered.
[Example]
Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples. Various measurement items in the examples were determined as follows. In the examples, “%” means “% by mass” unless otherwise specified.
<Evaluation method>
[Equivalent of sulfonic acid group]
The resulting sulfonated polymer was washed with distilled water until the washing water became neutral to remove free remaining acid, and then dried. Thereafter, a predetermined amount is weighed, dissolved in a mixed solvent of THF / water, titrated with a standard solution of NaOH using phenolphthalein as an indicator, and the equivalent of sulfonic acid groups (ion exchange capacity) from the neutral point. (Meq / g) was determined.
[Measurement of breaking strength and elastic modulus]
The breaking strength and elastic modulus were measured according to JISK7113 (tensile speed: 50 mm / min). However, the elastic modulus was calculated with the distance between marked lines as the distance between chucks. JI
According to SK7113, the sample was conditioned for 48 hours under conditions of a temperature of 23 ± 2 ° C. and a relative humidity of 50 ± 5%. However, the No. 7 dumbbell described in JISK6251 was used for punching the sample. As the tensile test measurement device, 5543 manufactured by INSTRON was used.
[Measurement of membrane resistance]
The membrane was sandwiched between conductive carbon plates from above and below via sulfuric acid having a concentration of 1 mol / l, the AC resistance between the carbon plates was measured at room temperature, and the following formula was obtained.
Membrane resistance (Ω · cm ² ) = resistance value between carbons across the membrane (Ω) −blank value (Ω) × contact area (cm ² )
Conductivity (S / cm) = film thickness / (membrane resistance × 10000)
[Methanol aqueous solution immersion test]
The conductive membrane was immersed in 50 vol% 70 ° C. methanol aqueous solution for 6 hours. The area before and after immersion was measured, and the area change rate (%) was calculated.
Area change rate (%) = (Area after immersion / Area before immersion) × 100
[Methanol permeability]
It measured by the pervaporation measuring method (pervaporation method). A film was set in a predetermined cell, a 10% by mass aqueous methanol solution was supplied from the front side, the pressure was reduced from the back side, and the permeate was trapped with liquid nitrogen. The methanol permeation amount was calculated from the following formula.
Methanol permeation amount (g / m ² / h) = [permeate weight (g) / recovery time (h) / sample area (m ² )] × methanol concentration of permeate [Synthesis Example 1; synthesis of component (A) ]
In a 1 L separable three-necked flask equipped with a stirring blade, a thermometer, a nitrogen introduction tube, a Dean-Stark tube, and a cooling tube, 52.4 g (240 mmo) of 4,4′-difluorobenzophenone was added.
l), 14.1 g (60.0 mmol) of 4-chloro-4′-fluorobenzophenone, 70.2 g (203 mmol) of 4,4 ′-(1,3-phenylenediisopropylidene) bisphenol (Bis-M), bis 23.7 g (67.5 mmol) of (4-hydroxyphenyl) fluorene and 44.8 g (324 mmol) of potassium carbonate were weighed. DMAc (320 mL) and toluene (130 mL) were added, and the mixture was heated to reflux at 150 ° C. in a nitrogen atmosphere. The water produced by the reaction was removed from the Dean-Stark tube by azeotroping with toluene. When no more water was observed after 3 hours, toluene was removed from the system and stirred at 160 ° C. for 7 hours. Then, 7.7 g (33.0 mmol) of 4-chloro-4′-fluorobenzophenone was added, and Stir for 3 hours.

After standing to cool, inorganic substances insoluble in the reaction solution were removed by filtration using Celite as a filter aid. The filtrate was poured into 2.0 L of methanol to solidify the reaction product. The precipitated coagulum was filtered, washed with a small amount of methanol, and vacuum dried. The dried product was redissolved in 200 mL of tetrahydrofuran. This solution was poured into 2.0 L of methanol and reprecipitated. The coagulated product was filtered and dried under vacuum to obtain 110 g (yield 74%) of the desired product. The number average molecular weight in terms of polystyrene determined by GPC was 5,500, and the weight average molecular weight was 8,300. It was confirmed that the obtained compound was an oligomer represented by the structure represented by the following formula (9).

... (9)
Synthesis of sulfonated polymer Stirrer, thermometer, 1 L three-necked flask equipped with a nitrogen inlet tube was charged with 56.1 g (140 mmol) of neopentyl 3- (2,5-dichlorobenzoyl) benzenesulfonate, the above compound (Mn5500) 38. 71 g (7.0 mmol), bis (triphenylphosphine) nickel dichloride 2.88 g (4.0 mmol), sodium iodide 0.66 g (4.0 mm)
ol), 15.4 g (60 mmol) of triphenylphosphine, and 23.0 g (352 mmol) of zinc were weighed and substituted with dry nitrogen. Here, N, N-dimethylacetamide (DMAc)
253 mL was added and stirring was continued for 3 hours while maintaining the reaction temperature at 80 ° C. Then, 780 mL of DMAc was added for dilution, and insoluble matters were filtered.

The obtained solution was put into a 2 L three-necked flask equipped with a stirrer, a thermometer, and a nitrogen introduction tube. The mixture was heated and stirred at 115 ° C., and 40.1 g (462 mmol) of lithium bromide was added. After stirring for 7 hours, the product was precipitated by pouring into 3.7 L of acetone. Subsequently, after washing in order of 1N hydrochloric acid and pure water, it was dried to obtain 67 g of the intended polymer. The weight average molecular weight (Mw) of the obtained polymer was 165,000. The proton conductive polymer (component (A)) obtained here is referred to as “polymer A1”. The polymer A1 is a polymer represented by the following formula (10). Polymer A
The ion exchange capacity of 2 was 1.7 meq / g.

... (10)
[Example 1]
In a 100 mL sample tube, 5.06 g of 3- (trihydroxysilyl) -1-propanesulfonic acid (component (Bb); the following formula (11)), 0.12 g of benzenesulfonic acid monohydrate, water 0 .67 g was added and stirred for 5 minutes. Thereafter, 4.2 g of N-methylpyrrolidone and 3.07 g of an imidazole-containing component (Ba) represented by the following formula (12) were additionally added to cause hydrolysis and dehydration condensation polymerization reaction. After completion of the reaction, the mixture is concentrated by an evaporator, and a mixed solvent of N-methylpyrrolidone / methanol = 3/1 (mass ratio) is added so that the total concentration of components (Ba) and (BB) is 20 wt%. A sol solution was prepared.
_{(HO) 3 -Si-CH 2} CH 2 CH 2 -SO 3 H (11)

2 g of the polymer A1 obtained in Synthesis Example 1 was added to N-methylpyrrolidone / methanol = 3/1.
A mixed solution was prepared by stirring 2.5 g of the above-mentioned sol solution dropwise into a polymer solution dissolved in 12.3 g of (mass ratio) mixed solvent (Table 1).

  The mixed solution is formed into a film on a PET substrate with a doctor blade, dried at 80 ° C. for 30 minutes, 100 ° C. for 30 minutes, and 140 ° C. for 1 hour, and then immersed in water four times for 1 hour at 25 ° C. Was distilled off to obtain a polymer electrolyte membrane (20-1) having a thickness of 40 μm.

Table 2 shows the measurement results of mechanical properties, membrane resistance, degree of swelling in methanol solution, and methanol permeability of the obtained polymer electrolyte membrane.
[Example 2]
In a 100 mL sample tube, TEOS (component (Bc)) 6.09 g, 3- (trihydroxysilyl) -1-propanesulfonic acid (component (Bb)) 0.92 g, benzenesulfonic acid monohydrate 0.12 g of the product and 0.67 g of water were added and stirred for 5 minutes. Thereafter, 4.2 g of N-methylpyrrolidone and 0.48 g of the imidazole-containing component (Ba) represented by the formula (12) were additionally added to cause hydrolysis and dehydration condensation polymerization reaction. After completion of the reaction, the mixture is concentrated by an evaporator, and a mixed solvent of N-methylpyrrolidone / methanol = 3/1 (mass ratio) is added so that the total concentration of components (Ba) to (Bd) is 20 wt%. A sol solution was prepared.

2 g of the polymer A1 obtained in Synthesis Example 1 was added to N-methylpyrrolidone / methanol = 3/1.
A mixed solution was prepared by stirring 2.5 g of the above-mentioned sol solution dropwise into a polymer solution dissolved in 12.3 g of (mass ratio) mixed solvent (Table 1).

  The mixed solution is formed into a film on a PET substrate with a doctor blade, dried at 80 ° C. for 30 minutes, 100 ° C. for 30 minutes, and 140 ° C. for 1 hour, and then immersed in water four times for 1 hour at 25 ° C. Was distilled off to obtain a polymer electrolyte membrane (20-2) having a thickness of 40 μm.

Table 2 shows the measurement results of mechanical properties, membrane resistance, degree of swelling in methanol solution, and methanol permeability of the obtained polymer electrolyte membrane.
[Example 3]
In a 100 mL sample tube, TEOS (component (Bc)) 5.32 g, 3- (trihydroxysilyl) -1-propanesulfonic acid (component (Bb)) 0.92 g, benzenesulfonic acid monohydrate 0.12 g of the product and 0.67 g of water were added and stirred for 5 minutes. Thereafter, 4.2 g of N-methylpyrrolidone and 0.48 g of the imidazole-containing component (Ba) represented by the formula (12) were additionally added to cause hydrolysis and dehydration condensation polymerization reaction. After stirring for 1 hour, 2.53 g of titanium tetra-iso-propoxide (component (Bd)) / acetylacetone mixed solution (1/4 molar ratio) was added, and the mixture was further stirred for 1 hour or more. After completion of the reaction, the mixture is concentrated by an evaporator, and a mixed solvent of N-methylpyrrolidone / methanol = 3/1 (mass ratio) is added so that the total concentration of components (Ba) to (Bd) is 20 wt%. A sol solution was prepared.

2 g of the polymer A1 obtained in Synthesis Example 1 was added to N-methylpyrrolidone / methanol = 3/1.
A mixed solution was prepared by stirring 2.5 g of the above-mentioned sol solution dropwise into a polymer solution dissolved in 12.3 g of (mass ratio) mixed solvent (Table 1).

  The mixed solution is formed into a film on a PET substrate with a doctor blade, dried at 80 ° C. for 30 minutes, 100 ° C. for 30 minutes, and 140 ° C. for 1 hour, and then immersed in water four times for 1 hour at 25 ° C. Was distilled off to obtain a polymer electrolyte membrane (20-3) having a thickness of 40 μm.

Table 2 shows the measurement results of mechanical properties, membrane resistance, degree of swelling in methanol solution, and methanol permeability of the obtained polymer electrolyte membrane.
[Comparative Example 1]: When component (Bb) is not present (1)
In a 100 mL sample tube, 10.76 g of the imidazole-containing component (Ba) represented by the formula (12), 0.12 g of benzenesulfonic acid monohydrate, 0.67 g of water, 4.2 g of N-methylpyrrolidone, Was added to cause hydrolysis and dehydration condensation polymerization reaction. After completion of the reaction, the solution is concentrated by an evaporator, and a mixed solvent of N-methylpyrrolidone / methanol = 3/1 (mass ratio) is added so that the total concentration of the component (Ba) is 20 wt% to prepare a sol solution. did.

2 g of the polymer A1 obtained in Synthesis Example 1 was added to N-methylpyrrolidone / methanol = 3/1.
A mixed solution was prepared by stirring 2.5 g of the above-mentioned sol solution dropwise into a polymer solution dissolved in 12.3 g of (mass ratio) mixed solvent (Table 1).

  The mixed solution is formed into a film on a PET substrate with a doctor blade, dried at 80 ° C. for 30 minutes, 100 ° C. for 30 minutes, and 140 ° C. for 1 hour, and then immersed in water four times for 1 hour at 25 ° C. Was distilled off to obtain a polymer electrolyte membrane (20-4) having a thickness of 40 μm.

Table 2 shows the measurement results of mechanical properties, membrane resistance, degree of swelling in methanol solution, and methanol permeability of the obtained polymer electrolyte membrane.
[Comparative Example 2]: When component (Bb) is absent (2)
TEOS (component (Bc)) 5.32 g in a 100 mL sample tube, imidazole-containing component (Ba) represented by the formula (12) 1.88 g, benzenesulfonic acid monohydrate 0.12 g, 0.67 g of water and 4.2 g of N-methylpyrrolidone were added to cause hydrolysis and dehydration condensation polymerization reaction. After stirring for 1 hour, titanium tetra-iso-propoxide (component (
Bd)) / acetylacetone mixed solution (1/4 molar ratio) (2.53 g) was added, and the mixture was further stirred for 1 hour or more. After completion of the reaction, it is concentrated by an evaporator, and after completion of the components (Ba) (Bc) (Bd), it is concentrated by an evaporator so that the total concentration of the components (Ba) is 20 wt%. A mixed solvent of N-methylpyrrolidone / methanol = 3/1 (mass ratio) was added to prepare a sol solution.

2 g of the polymer A1 obtained in Synthesis Example 1 was added to N-methylpyrrolidone / methanol = 3/1.
A mixed solution was prepared by stirring 2.5 g of the above-mentioned sol solution dropwise into a polymer solution dissolved in 12.3 g of (mass ratio) mixed solvent (Table 1).

  The mixed solution is formed into a film on a PET substrate with a doctor blade, dried at 80 ° C. for 30 minutes, 100 ° C. for 30 minutes, and 140 ° C. for 1 hour, and then immersed in water four times for 1 hour at 25 ° C. Was distilled off to obtain a polymer electrolyte membrane (20-4) having a thickness of 40 μm.

Table 2 shows the measurement results of mechanical properties, membrane resistance, degree of swelling in methanol solution, and methanol permeability of the obtained polymer electrolyte membrane.
[Comparative Example 3]: When component (B-a) is not present In a 100 mL sample tube, 7.08 g of 3- (trihydroxysilyl) -1-propanesulfonic acid (component (Bb)), benzenesulfonic acid · 1 0.12 g of hydrate, 0.67 g of water and 4.2 g of N-methylpyrrolidone were added to cause hydrolysis and dehydration condensation polymerization reaction. After completion of the reaction, the mixture is concentrated by an evaporator, and a mixed solvent of N-methylpyrrolidone / methanol = 3/1 (mass ratio) is added so that the total concentration of the component (Bb) is 20 wt% to prepare a sol solution. did.
2 g of the polymer A1 obtained in Synthesis Example 1 was mixed with N-methylpyrrolidone / methanol = 3/1 (
A mixed solution was prepared by stirring 2.5 g of the above-described sol solution dropwise in a polymer solution dissolved in 12.3 g of a mixed solvent (mass ratio) (Table 1).

  The mixed solution is formed into a film on a PET substrate with a doctor blade, dried at 80 ° C. for 30 minutes, 100 ° C. for 30 minutes, and 140 ° C. for 1 hour, and then immersed in water four times for 1 hour at 25 ° C. Was distilled off to obtain a polymer electrolyte membrane (20-6) having a thickness of 40 μm.

  Table 2 shows the measurement results of mechanical properties, membrane resistance, degree of swelling in methanol solution, and methanol permeability of the obtained polymer electrolyte membrane.

  As shown in Table 2, Examples 1 to 3 can reduce membrane resistance, improve proton conduction, and suppress methanol permeability and area change rate in aqueous methanol solution. all right. Moreover, it turned out that an effect becomes further remarkable by addition of a component (Bc) and (Bd). From the comparative example, it was found that only when both the components (Ba) and (BB) are included as essential components, it is possible to achieve both improvement in conductivity and suppression of methanol permeation as compared with the conventional case.

Claims (14)

(A) a proton conducting polymer, and
(B) a reaction product obtained by subjecting a composition containing the following components (Ba) and (BB) to hydrolysis / dehydration condensation reaction;
(Ba): Compound represented by the following formula (6) (Bb): Compound represented by the following formula (7),
A polymer electrolyte for a direct methanol fuel cell, comprising:
Si (OR ²⁰ ) _E (R ²¹ ) _F (R ²² ) _G ... (6)
(In the formula (6), E is 2 to 3, F is 0 to 1, G is 1 to 2, and E + F + G = 4. Also, R ²⁰ and R ²¹ are hydrogen atoms or halogenated. R ²² is a nitrogen-containing heterocyclic structure or an optionally halogenated hydrocarbon group having an optionally substituted amino group.)
Si (OR ³⁰ ) _{E '} (R ³¹ ) _F' (R ³² ) _{G '} (7)
(In the formula (7), E ′ is 2 to 3, F ′ is 0 to 1, G ′ is 1 to 2, and E ′ + F ′ + G ′ = 4. Also, R ³⁰ and R ³¹ are A hydrogen atom or an optionally halogenated hydrocarbon group, and R ³² is an optionally halogenated hydrocarbon group having a protonic acid group.) The component (B) is a reaction product obtained by subjecting a composition containing the components (Ba), (BB), and the following component (BC) to a hydrolysis / dehydration condensation reaction. A polymer electrolyte for a direct methanol fuel cell as described in 1.
(Bc): Compound represented by the following formula (8) other than the components (Ba) and (Bb)
Si (OR ⁴⁰ ) _e (R ⁴¹ ) _f (8)
(In the formula (8), e is 2 to 4, f is 0 to 2, and e + f = 4. R ⁴⁰ and R ⁴¹ are a hydrogen atom or an optionally halogenated hydrocarbon group. ) (B) A reaction product obtained by subjecting a composition containing the components (Ba), (Bb), (Bc) and the following component (Bd) to a hydrolysis / dehydration condensation reaction: The polymer electrolyte for direct methanol fuel cells according to claim 2, wherein
(Bd): Al, Ti or Zr alkoxide The group represented by R ²² in the formula (6) representing the component (Ba) is a pyrrole group, a thiazole group, a benzothiazole group, an isothiazole group, an oxazole group, a benzoxazole group, an isoxazole group, or an imidazole. Group, imidazoline group, imidazolidine group, benzimidazole group, pyrazole group, triazine group, pyridine group, pyrimidine group, pyridazine group, pyrazine group, indole group, quinoline group, isoquinoline group, bromine group, tetrazole group, tetrazine group, triazole Group, carbazole group, acridine group, quinoxaline group, quinazoline group, indolizine group, isoindole group, 3H-indole group, 2H-pyrrole group, 1H-indazole group, purine group, phthalazine group, naphthyridine group, cinnoline group, pteridine Group, carboline group, phenanthri Gin group, perimidine group, phenanthroline group, phenazine group, phenalsazine group, phenothiazine group, furazane group, phenoxazine group, pyrrolidine group, pyrroline group, pyrazoline group, pyrazolidine group, piperidine group, piperazine group, indoline group, isoindoline group, The quinuclidine group, the primary amino group, the secondary amino group, the tertiary amino group and at least one group derived from a compound selected from the group consisting of these derivatives, The polymer electrolyte for a direct methanol fuel cell according to any one of the above. The group represented by R ²² in the formula (6) representing the component (Ba) is an imidazole group, an imidazoline group, a pyridine group, a pyrrole group, a benzimidazole, a benzoxazole, a triazine group, a triazole group, 1 The high for direct methanol fuel cells according to any one of claims 1 to 4, comprising at least one group selected from the group consisting of a secondary amine group, a secondary amine group, and a tertiary amine group. Molecular electrolyte. In the formula (8) representing the component (Bc), the groups represented by R ⁴⁰ and R ⁴¹ are a methyl group, an ethyl group, a propyl group, an iso-propyl group, an n-propyl group, a butyl group. And at least one group selected from the group consisting of hydrocarbon groups consisting of iso-butyl, hexyl, octyl, decyl, dodecyl, cyclopentyl, cyclohexyl, phenyl, and trifluoropropyl. The polymer electrolyte for a direct methanol fuel cell according to any one of claims 1 to 5, wherein:   The said component (Bd) contains titanium alkoxide, The polymer electrolyte for direct methanol as described in any one of Claims 1-6 characterized by the above-mentioned.   The component (A) has at least one group selected from the group consisting of a sulfonic acid group, a carboxylic acid group, a phosphoric acid group, and a phenolic hydroxyl group. The polymer electrolyte for a direct methanol fuel cell according to the item.   The component (A) is a perfluorosulfonic acid polymer, a perfluorocarbon polymer having a carboxyl group and a sulfonic acid group, and a polyetherketone, polyetheretherketone, polysulfide having a sulfonic acid or alkylsulfonic acid group, Polyphosphazene, polyarylene, polyphenylene, polybenzimidazole, polyethersulfone, polyetherethersulfone, polyphenylene oxide, polyimide, polysulfone, polysulfonate, polybenzimidazole, polybenzoxazole, polybenzothiazole, polythiazole, polyphenylquinoxaline, 9. The direct as claimed in claim 1, which is at least one selected from the group consisting of polyquinoline, polysiloxane and polytriazine. Polymeric electrolyte for tomethanol fuel cells. The polymer for direct methanol fuel cells according to claim 1, wherein the component (A) is a polyarylene-based copolymer containing a structural unit represented by the following general formula (1). Electrolytes.

Wherein Y is —CO—, —SO ₂ —, —SO—, —CONH—, —COO—, — (CF ₂ ) ₁ — (l is an integer of 1 to 10), —C (CF ₃ ) represents at least one structure selected from the group consisting of ₂ —, Z is a direct bond, or — (CH ₂ ) ₁ — (l is an integer of 1 to 10), —C (CH ₃ ) ₂ represents at least one structure selected from the group consisting of —, —O—, and —S—, and Ar represents —SO ₃ H or —O (CH ₂ ) _p SO ₃ H or —O (CF ₂ ) _p An aromatic group having a substituent represented by SO ₃ H. p represents an integer of 1 to 12, m represents an integer of 0 to 10, n represents an integer of 0 to 10, and k represents 1 Represents an integer of ~ 4.) 11. The polymer for a direct methanol fuel cell according to claim 1, wherein the component (A) is a polyarylene copolymer containing a structural unit represented by the following general formula (2). Electrolytes.

(In the formula, A and D are independently a direct bond, or —CO—, —SO ₂ —, —SO—, —CONH.
-, - COO -, - ( CF 2) l - (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 group, —O—, and —S—. B represents independently an oxygen atom or a sulfur atom, R ^{1 to} R ¹⁶ 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 It represents at least one atom or group selected from the group consisting of halogenated alkyl groups, allyl groups, aryl groups, nitro groups, and nitrile groups. s and t represent an integer of 0 to 4, and r represents 0 or an integer of 1 or more.   The polymer electrolyte for a direct methanol fuel cell according to any one of claims 1 to 11, wherein the ion exchange capacity is 0.1 to 5 meq / g. A step of hydrolyzing and condensing the following (Ba) to (Bd) components to obtain a hydrolysis condensate, a step of concentrating the solvent in the hydrolysis condensate to change the solvent composition, (A) and the step A step of applying a mixed solution obtained by dissolving the hydrolysis condensate in a solvent onto a substrate to form a coating film, and removing at least part of the solvent contained in the coating film to form a polymer electrolyte membrane A method for producing a polymer electrolyte membrane for a direct methanol fuel cell, comprising the step of:
(Ba): Compound represented by the following formula (6) (Bb): Compound represented by the following formula (7),
(Bc): a compound represented by the following formula (8) other than the components (Ba) and (Bb), and (Bd) an alkoxide of Al, Ti, or Zr
Si (OR ²⁰ ) _E (R ²¹ ) _F (R ²² ) _G ... (6)
(In the formula (6), E is 2 to 3, F is 0 to 1, G is 1 to 2, and E + F + G = 4. Also, R ²⁰ and R ²¹ are hydrogen atoms or halogenated. R ²² is a nitrogen-containing heterocyclic structure or an optionally halogenated hydrocarbon group having an optionally substituted amino group.)
Si (OR ³⁰ ) _{E '} (R ³¹ ) _F' (R ³² ) _{G '} (7)
(In the formula (7), E ′ is 2 to 3, F ′ is 0 to 1, G ′ is 1 to 2, and E ′ + F ′ + G ′ = 4. Also, R ³⁰ and R ³¹ are A hydrogen atom or an optionally halogenated hydrocarbon group, and R ³² is an optionally halogenated hydrocarbon group having a protonic acid group.)
Si (OR ⁴⁰ ) _e (R ⁴¹ ) _f (8)
(In the formula (8), e is 2 to 4, f is 0 to 2, and e + f = 4. R ⁴⁰ and R ⁴¹ are a hydrogen atom or an optionally halogenated hydrocarbon group. ) A polymer electrolyte membrane in which a reaction product obtained by hydrolytic condensation of the following components (Ba) and (Bb) is compatible or dispersed in component (A).
(A) a proton conductive polymer;
(Ba): a compound represented by the following formula (6),
Si (OR ²⁰ ) _E (R ²¹ ) _F (R ²² ) _G (6)
(In Formula (6), E is 2-3, F is 0-1, G is 1-2, and E + F + G = 4. R ²⁰ and R ²¹ are hydrogen atoms or halogenated. R ²² is a nitrogen-containing heterocyclic structure or an optionally halogenated hydrocarbon group having an optionally substituted amino group.)
(Bb): a compound represented by the following formula (7),
Si (OR ³⁰ ) _{E '} (R ³¹ ) _F' (R ³² ) _{G '} (7)
(In the formula (7), E ′ is 2 to 3, F ′ is 0 to 1, G ′ is 1 to 2, and E ′ + F ′ + G ′ = 4. R ³⁰ and R ³¹ are hydrogen. (It is an optionally halogenated hydrocarbon group. R ³² is an optionally halogenated hydrocarbon group having a protonic acid group.)