JP2005146145A - Polymer composition and composite film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polymer composition excellent in proton conductivity, strength, toughness, and adhesiveness and a composite film made thereof. <P>SOLUTION: The polymer composition contains a sulfonated polyarylene polymer consisting of repeating units represented by general formulas (1) and (2) and a sulfo-group-containing polymer rich in flexural castability. In general formula (1), A is a divalent electron-withdrawing group; B is a divalent electron-donating group or a direct bond; Ar is an aromatic group having a substituent expressed by -SO<SB>3</SB>H; m and n are each an integer of 0-10; and k is an integer of 1-4. In general formula (2), R<SP>1</SP>to R<SP>8</SP>are each at least one kind of atom or group selected from the group consisting of a hydrogen atom, a fluorine atom, an alkyl group, a fluorinated alkyl group, an allyl group, an aryl group, and a cyano group; W is a divalent electron-withdrawing group or a single bond; T is a single bond or a divalent organic group; and when T is -O-, p is a positive integer of 2 or more and when T is other than -O-, p is a positive integer of 1 or more. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a polymer composition comprising a sulfonated polyarylene having proton conductivity as a main component, and a composite film comprising the polymer composition and excellent in proton conductivity, strength, toughness and adhesion to metal. About.

  The electrolyte is usually used in a (water) solution. However, in recent years, there is an increasing tendency to replace this with a solid system. The first reason is, for example, the ease of processing when applied to the above-mentioned electric / electronic materials, and the second reason is the shift to light, thin, small and high power.

  Conventionally, both proton-conducting materials made of inorganic substances and organic substances are known. Examples of inorganic substances include, for example, uranyl phosphate, which is a hydrated compound, but these inorganic compounds do not have sufficient contact at the interface, and there are many problems in forming a conductive layer on a substrate or electrode.

  On the other hand, examples of organic compounds include polymers belonging to so-called cation exchange resins, for example, sulfonated vinyl polymers such as polystyrene sulfonic acid, and perfluoroalkyl sulfonic acid polymers represented by Nafion (registered trademark, manufactured by DuPont). , Perfluoroalkylcarboxylic acid polymers, and polymers in which sulfonic acid groups or phosphoric acid groups are introduced into heat-resistant polymers such as polybenzimidazole and polyetheretherketone [Polymer Preprints, Japan, Vol.42, No.7, p. (2490-2492 (1993), Polymer Preprints, Japan, Vol.43, No.3, p.735-736 (1994), Polymer Preprints, Japan, Vol.42, No.3, p.730 (1993)) And organic polymers such as

  These organic polymers are usually used in the form of a film, but have an advantage that a conductive film can be bonded on an electrode by utilizing the solubility in a solvent or thermoplasticity. However, in many of these organic polymers, proton conductivity is not yet sufficient, durability, proton conductivity at high temperature (100 ° C. or higher) is reduced, and dependency on humidity conditions is high. There is a problem that it is large or the adhesion to the electrode is not sufficiently satisfactory, or the strength is reduced due to excessive swelling during operation due to the water-containing polymer structure and the shape is collapsed. Therefore, these organic polymers have various problems when applied to the above-mentioned electric / electronic materials.

US Pat. No. 5,403,675 (Patent Document 1) proposes a solid polymer comprising a sulfonated rigid polyphenylene (that is, a sulfonated product having a polyarylene structure as a main component). This polymer is mainly composed of a polymer comprising a phenylene chain obtained by polymerizing an aromatic compound (structure described in column 9 of the same specification), and this is reacted with a sulfonating agent to introduce a sulfonic acid group. Yes. However, although the proton conductivity is improved by increasing the amount of sulfonic acid groups introduced, the mechanical properties of the resulting sulfonated polymer are significantly impaired. Therefore, it is necessary to adjust the appropriate sulfonation concentration to maintain excellent mechanical properties and to exhibit proton conductivity, but with this polymer, the sulfonation reaction is easy to proceed and the introduction of appropriate sulfonic acid groups It is very difficult to control the amount.
US Pat. No. 5,403,675

  The present invention has been made against the background of the above-mentioned conventional technical problems. A polymer composition capable of obtaining a film excellent in proton conductivity, strength, toughness, and adhesion, and a composite comprising the polymer composition It is to provide a membrane.

The polymer composition of the present invention comprises:
A sulfonated polyarylene polymer having a sulfonic acid group composed of a repeating unit represented by the following general formula (1) and a repeating unit represented by the following general formula (2);
And a polymer having a structure rich in bending castability and having a sulfonic acid group.

(In the formula, A represents a divalent electron-withdrawing group, B represents a divalent electron-donating group or a direct bond, Ar represents an aromatic group having a substituent represented by —SO ₃ H, m represents an integer of 0 to 10, n represents an integer of 0 to 10, and k represents an integer of 1 to 4.)

(Wherein R ^{1 to} R ⁸ may be the same as or different from each other, and are at least one selected from the group consisting of a hydrogen atom, a fluorine atom, an alkyl group, a fluorine-substituted alkyl group, an allyl group, an aryl group, and a cyano group) W represents a divalent electron-withdrawing group or a single bond, T represents a single bond or a divalent organic group, p represents a positive integer of 2 or more when T is —O—, If it is other than -O-, it represents a positive integer of 1 or more.)
The content of the sulfonated polyarylene polymer is preferably 30 to 95% by weight with respect to the entire composition.

  Since the composite membrane (proton conductive membrane) obtained from the polymer composition of the present invention is a composite of a sulfonated polyarylene and a polymer having a structure rich in bending castability, through liquid homogenization, Without impairing proton conductivity, it is excellent in strength properties, toughness, adhesion to a substrate, etc. and hot water resistance as compared with a membrane composed only of sulfonated polyarylene.

Therefore, the composite membrane of the present invention has high pronton conductivity over a wide temperature range, and is excellent in adhesion to a substrate or an electrode, strength and hot water resistance. Therefore, an electrolyte for a primary battery, an electrolyte for a secondary battery, It can be used as a conductive membrane such as a solid polymer electrolyte for fuel cells, a display element, various sensors, a signal transmission medium, a solid capacitor, and an ion exchange membrane.

  The polymer composition of the present invention has a sulfonated polyarylene-based polymer having a sulfonic acid group (hereinafter also referred to as “first polymer”), a structure rich in bending castability, and And a polymer having a sulfonic acid group (hereinafter, also referred to as “second polymer”).

<First polymer>
The sulfonated polyarylene polymer having a sulfonic acid group used in the present invention includes a repeating unit represented by the following general formula (1) and a repeating unit represented by the following general formula (2). The polymer represented by the following general formula (3).

In the formula (1), A represents a divalent electron-withdrawing group, specifically, —CO—, —SO ₂ —,
—SO—, —CONH—, —COO—, — (CF ₂ ) ₁ — (wherein l is an integer of 1 to 10), —C (CF ₃ ) ₂ — and the like can be mentioned.

B represents a divalent electron-donating group or a direct bond, and specific examples of the electron-donating group include
— (CH ₂ ) —, —C (CH ₃ ) ₂ —, —O—, —S—, —CH═CH—, —C≡C— and

Etc. The electron-withdrawing group means a group having a Hammett substituent constant of 0.06 or more when the phenyl group is in the m-position and 0.01 or more when the p-position is p-position.

Ar represents an aromatic group having a substituent represented by —SO ₃ H, and specific examples of the aromatic group include a phenyl group, a naphthyl group, an anthracenyl group, and a phenanthyl group. Of these groups, a phenyl group and a naphthyl group are preferable.

  m represents an integer of 0 to 10, preferably 0 to 2, n represents an integer of 0 to 10, preferably 0 to 2, and k represents an integer of 1 to 4.

In formula (2), R ^{1 to} R ⁸ may be the same or different from each other, and at least selected from the group consisting of a hydrogen atom, a fluorine atom, an alkyl group, a fluorine-substituted alkyl group, an allyl group, an aryl group, and a cyano group. One atom or group is shown.

  Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, an amyl group, and a hexyl group, and a methyl group and an ethyl group are preferable.

  Examples of the fluorine-substituted alkyl group include trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluorobutyl group, perfluoropentyl group, perfluorohexyl group, trifluoromethyl group, pentafluoroethyl group, and the like. Etc. are preferable.

  Examples of the allyl group include a propenyl group, and examples of the aryl group include a phenyl group and a pentafluorophenyl group.

  W represents a single bond or a divalent electron-withdrawing group, and T represents a single bond or a divalent organic group. In Formula (2), when T is —O—, p is a positive integer of 2 or more, and when other than —O—, p is a positive integer of 1 or more, and the upper limit is usually 100, preferably 10 80.

In the formula (3), W, T, A, B, Ar, m, n, k, p and R ^{1 to} R ⁸ are respectively W, T, A, and R in the general formulas (1) and (2). B, and Ar, m, n, k, and p and R ¹ to R ⁸ synonymous.

The sulfonated polyarylene polymer used in the present invention contains 0.5 to 100 mol%, preferably 10 to 99.999 mol% of the repeating unit represented by the formula (1) in the formula (2).
In the ratio of 99.5 to 0 mol%, preferably 90 to 0.001 mol%.

  The sulfonated polyarylene polymer includes a monomer having a sulfonate group that can be a structural unit represented by the general formula (1) and an oligomer that can be a structural unit represented by the general formula (2). It can be synthesized by copolymerizing to produce a polyarylene having a sulfonic acid ester group, hydrolyzing the polyarylene having the sulfonic acid ester group, and converting the sulfonic acid ester group to a sulfonic acid group.

  In addition, the sulfonated polyarylene-based polymer previously synthesizes a polyarylene comprising the structural unit having no sulfonic acid group and sulfonic acid ester group in the general formula (1) and the structural unit of the general formula (2). The polymer can also be synthesized by sulfonation.

  Examples of the monomer that can be the structural unit of the general formula (1) include a monomer represented by the following general formula (4) (hereinafter also referred to as a monomer (4)).

In the formula (4), X is a halogen atom excluding fluorine (chlorine, bromine, iodine), -OSO ₂ Z (
Here, Z represents an alkyl group, a fluorine-substituted alkyl group or an aryl group. ), A, B, Ar, m, n and k have the same meanings as A, B, Ar, m, n and k in the general formula (1), respectively.

R ^a represents a hydrocarbon group having 1 to 20 carbon atoms, preferably 4 to 20 carbon atoms, specifically, methyl group, ethyl group, n-propyl group, iso-propyl group, tert-butyl group, iso- Butyl, n-butyl, sec-butyl, neopentyl, cyclopentyl, hexyl, cyclohexyl, cyclopentylmethyl, cyclohexylmethyl, adamantyl, adamantanemethyl, 2-ethylhexyl, bicyclo [2.2 .1] heptyl group, bicyclo [2.2.1] heptylmethyl group, tetrahydrofurfuryl group, 2-methylbutyl group, 3,3-dimethyl-2,4-dioxolanemethyl group, cyclohexylmethyl group, adamantylmethyl group Linear hydrocarbon groups such as bicyclo [2.2.1] heptylmethyl group, branched hydrocarbon groups, alicyclic hydrocarbons Group, such as a hydrocarbon group having 5-membered heterocycles. Among these, n-butyl group, neopentyl group, tetrahydrofurfuryl group, cyclopentyl group, cyclohexyl group, cyclohexylmethyl group, adamantylmethyl group, and bicyclo [2.2.1] heptylmethyl group are preferable, and neopentyl group is particularly preferable. preferable.

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

The substituent —SO ₃ R ^b is substituted with one or more aromatic groups, and when two or more substituents —SO ₃ R ^b are substituted, these substituents are the same as each other. But it can be different.

Here, R ^b represents a hydrocarbon group having 1 to 20 carbon atoms, preferably 4 to 20 carbon atoms, and specific examples thereof include the hydrocarbon groups having 1 to 20 carbon atoms. Among these, n-butyl group, neopentyl group, tetrahydrofurfuryl group, cyclopentyl group, cyclohexyl group, cyclohexylmethyl group, adamantylmethyl group, and bicyclo [2.2.1] heptylmethyl group are preferable, and neopentyl group is particularly preferable. preferable.

  m represents an integer of 0 to 10, preferably 0 to 2, n represents an integer of 0 to 10, preferably 0 to 2, and k represents an integer of 1 to 4.

  Specific examples of the sulfonic acid ester represented by the formula (4) include the following compounds.

In the above compound, a compound in which a chlorine atom is replaced with a bromine atom, a compound in which —CO— is replaced with —SO ₂ — in the above compound, a chlorine atom in the above compound is replaced with a bromine atom, and —CO— is —SO _2. Examples include compounds in which-is substituted.

The R ^b group in the general formula (4) is derived from a primary alcohol, and the β carbon is a tertiary or quaternary carbon, which is excellent in stability during the polymerization process, and can generate sulfonic acid by deesterification. It is preferable in that it does not cause polymerization inhibition and cross-linking, and it is preferable that these ester groups are derived from primary alcohols and the β-position is a quaternary carbon.

  In the above general formula (4), specific examples of the compound having no sulfonic acid group or sulfonic acid ester group include the following compounds.

A compound in which the chlorine atom is replaced with a bromine atom in the above compound, a compound in which —CO— is replaced with —SO ₂ — in the above compound, a chlorine atom in the above compound is replaced with a bromine atom, and —CO— is —SO ₂ —. And compounds that have been replaced with.

  Examples of the oligomer that can be the structural unit of the general formula (2) include an oligomer represented by the following general formula (5) (hereinafter also referred to as oligomer (5)).

In the formula (5), R ′ and R ″ may be the same as or different from each other, and a halogen atom or —OSO ₂ Z excluding a fluorine atom (where Z is an alkyl group, a fluorine-substituted alkyl group or an aryl group) The group represented by this is shown. Examples of the alkyl group represented by Z include a methyl group and an ethyl group, examples of the fluorine-substituted alkyl group include a trifluoromethyl group, and examples of the aryl group include a phenyl group and a p-tolyl group.

R ^{1 to} R ⁸ may be the same or different from each other, and are at least one atom or group selected from the group consisting of a hydrogen atom, a fluorine atom, an alkyl group, a fluorine-substituted alkyl group, an allyl group, an aryl group, and a cyano group. Indicates.

Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, an amyl group, and a hexyl group, and a methyl group and an ethyl group are preferable.
Examples of the fluorine-substituted alkyl group include trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluorobutyl group, perfluoropentyl group, perfluorohexyl group, trifluoromethyl group, pentafluoroethyl group, and the like. Etc. are preferable.

  Examples of the allyl group include a propenyl group, and examples of the aryl group include a phenyl group and a pentafluorophenyl group.

  W represents a single bond or a divalent electron-withdrawing group, and examples of the electron-withdrawing group include those described above.

  T is a single bond or a divalent organic group, and may be an electron-withdrawing group or an electron-donating group. Examples of the electron-withdrawing group and the electron-donating group include the same groups as described above.

  When T is -O-, p is a positive integer of 2 or more, and when T is other than -O-, p is a positive integer of 1 or more, and the upper limit of p is usually 100, preferably 10-80. It is.

Examples of the compound represented by the general formula (5) include 2,2-bis [4- {4- (4-chlorobenzoyl) phenoxy} phenyl] -1,1,1,3,3,3-hexafluoro. propane,
Examples thereof include bis [4- {4- (4-chlorobenzoyl) phenoxy} phenyl] sulfone, and a compound represented by the following formula.

  The compound represented by the general formula (5) can be synthesized, for example, by the method shown below.

  First, in order to convert the bisphenol linked with an electron-withdrawing group into the corresponding alkali metal salt of bisphenol, N-methyl-2-pyrrolidone, N, N-dimethylacetamide, sulfolane, diphenylsulfone, dimethylsulfoxide, etc. In a polar solvent having a high dielectric constant, an alkali metal such as lithium, sodium or potassium, an alkali metal hydride, an alkali metal hydroxide, an alkali metal carbonate or the like is added.

The alkali metal is reacted in excess with respect to the hydroxyl group of phenol, and is usually used in an amount of 1.1 to 2 times equivalent, preferably 1.2 to 1.5 times equivalent. In this case, fluorine, chlorine, etc. activated with an electron-withdrawing group in the presence of azeotropic solvent such as benzene, toluene, xylene, hexane, cyclohexane, octane, chlorobenzene, dioxane, tetrahydrofuran, anisole, phenetole, etc. Aromatic halogen-substituted aromatic dihalide compounds such as 4,4′-difluorobenzophenone, 4,4′-dichlorobenzophenone, 4,4′-chlorofluorobenzophenone, bis (4-chlorophenyl) sulfone, bis (4 -Fluorophenyl) sulfone, 4-fluorophenyl-4'-chlorophenylsulfone, bis (3-nitro-4-chlorophenyl) sulfone, 2,6-dichlorobenzonitrile, 2,6-difluorobenzonitrile, hexafluorobenzene, deca Fluorobiphenyl, ,
5-difluorobenzophenone, 1,3-bis (4-chlorobenzoyl) benzene and the like are reacted. In terms of reactivity, a fluorine compound is preferable, but in consideration of the following aromatic coupling reaction, it is necessary to assemble an aromatic nucleophilic substitution reaction so that the terminal is a chlorine atom.

  The active aromatic dihalide is used in an amount of 2 to 4 times mol, preferably 2.2 to 2.8 times mol, of bisphenol. Prior to the aromatic nucleophilic substitution reaction, an alkali metal salt of bisphenol may be used. The reaction temperature is 60 ° C to 300 ° C, preferably 80 ° C to 250 ° C. The reaction time ranges from 15 minutes to 100 hours, preferably from 1 hour to 24 hours. The most preferable method is to use a chlorofluoro compound having one halogen atom having a different reactivity as the active aromatic dihalide represented by the following formula, and a nucleophilic substitution reaction with phenoxide occurs preferentially by the fluorine atom. It is convenient to obtain the desired activated terminal chloro form.

  In the formula, W is as defined for the general formula (5).

  Further, as described in JP-A-2-159, a flexible compound comprising a target electron-withdrawing group and electron-donating group may be synthesized by combining a nucleophilic substitution reaction and an electrophilic substitution reaction. .

Specifically, an aromatic bishalide activated with an electron-withdrawing group, for example, bis (4-chlorophenyl) sulfone is subjected to a nucleophilic substitution reaction with phenol to form a bisphenoxy compound, and then this bisphenoxy compound and 4-chloro The desired compound can be obtained from Friedel-Craft reaction with benzoic acid chloride.

  Examples of the aromatic bishalide activated with the electron-withdrawing group used here include the compounds exemplified above. The phenol compound may be substituted, but an unsubstituted compound is preferable from the viewpoint of heat resistance and flexibility. In addition, it is preferable to set it as an alkali metal salt for the substitution reaction of a phenol, and the compound illustrated above is mentioned as an alkali metal compound which can be used. The amount used is 1.2 to 2 moles per mole of phenol. In the reaction, the polar solvent described above or an azeotropic solvent with water can be used.

  Chlorobenzoic acid chloride is used in an amount of 2 to 4 times mol, preferably 2.2 to 3 times mol of the bisphenoxy compound. Further, the Friedel-Crafts reaction between the bisphenoxy compound and the acylating agent chlorobenzoic acid chloride is preferably performed in the presence of a Friedel-Craft activator such as aluminum chloride, boron trifluoride, or zinc chloride. . The Friedel-Craft activator is used in an amount of 1.1 to 2 times equivalent to 1 mol of an active halide compound such as chlorobenzoic acid as an acylating agent. The reaction time ranges from 15 minutes to 10 hours, and the reaction temperature ranges from -20 ° C to 80 ° C. As the solvent used, chlorobenzene, nitrobenzene and the like which are inert to Friedel-Craft reaction can be used.

Further, in the general formula (5), the compound in which p is 2 or more includes, for example, a bisphenol serving as a source of etheric oxygen that is the electron donating group T in the general formula (5) and an electron withdrawing group W. A compound in combination with at least one group selected from> C═O, —SO ₂ — and> C (CF ₃ ) ₂ , specifically 2,2-bis (4-hydroxyphenyl) -1 1,1,3,3,3-hexafluoropropane, alkali metal salts of bisphenols such as 2,2-bis (4-hydroxyphenyl) ketone, 2,2-bis (4-hydroxyphenyl) sulfone, and excess Substitution reaction with an active aromatic halogen compound such as 4,4-dichlorobenzophenone or bis (4-chlorophenyl) sulfone is carried out with N-methyl-2-pyrrolidone, N, N
-Obtained by sequentially polymerizing the monomer in the presence of a polar solvent such as dimethylacetamide or sulfolane.

  Examples of such a compound include a compound represented by the following formula.

In the above, p is a positive integer, and the upper limit is usually 100, preferably 10-80.

The polyarylene having a sulfonate group is synthesized by reacting the monomer (4) and the oligomer (5) in the presence of a catalyst. The catalyst used at this time is a catalyst containing a transition metal compound. This catalyst system includes (1) a transition metal salt and a compound that becomes a ligand (hereinafter referred to as “ligand component”), or a transition metal complex in which a ligand is coordinated (copper). Salt is included), and (2) a reducing agent is an essential component, and a “salt” may be added to increase the polymerization rate.

  Here, as the transition metal salt, 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; 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 component, triphenylphosphine, 2,2′-bipyridine, 1,5-
Examples include cyclooctadiene and 1,3-bis (diphenylphosphino) propane. Of these, triphenylphosphine and 2,2′-bipyridine are preferred. The compound which is the said ligand component may be used individually by 1 type, and may use 2 or more types together.

Furthermore, as the transition metal complex in which the ligand is coordinated, for example, nickel chloride bis (triphenylphosphine), nickel bromide bis (triphenylphosphine), 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 and the like. Of these, nickel chloride bis (triphenylphosphine) and nickel chloride (2,2′-bipyridine) are preferred.

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

  Examples of the “salt” that can be used in the above catalyst system include sodium compounds such as sodium fluoride, sodium chloride, sodium bromide, sodium iodide, sodium sulfate, potassium fluoride, potassium chloride, potassium bromide, Examples include potassium compounds such as potassium iodide and potassium sulfate; ammonium compounds such as tetraethylammonium fluoride, tetraethylammonium chloride, tetraethylammonium bromide, tetraethylammonium iodide, and tetraethylammonium sulfate. Of these, sodium bromide, sodium iodide, potassium bromide, tetraethylammonium bromide, and tetraethylammonium iodide are preferred.

  The proportion of each component used is usually 0.0001 to 10 mol, preferably 0.01, based on 1 mol of the total amount of the above monomers ((4) + (5), the same shall apply hereinafter) for the transition metal salt or transition metal complex. -0.5 mol. When the amount is less than 0.0001 mol, the polymerization reaction may not proceed sufficiently. On the other hand, when the amount exceeds 10 mol, the molecular weight may decrease.

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

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

  Furthermore, when using "salt", the usage-ratio is 0.001-100 mol normally with respect to the total of 1 mol of the said monomer, Preferably it is 0.01-1 mol. If it is less than 0.001 mol, the effect of increasing the polymerization rate may be insufficient, and if it exceeds 100 mol, purification of the resulting polymer may be difficult.

Examples of a polymerization solvent that can be used when the monomer (4) and the oligomer (5) are reacted include tetrahydrofuran, cyclohexanone, dimethyl sulfoxide, N,
N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, γ-butyrolactone, N, N′-dimethylimidazolidinone and the like can be mentioned. Of these, tetrahydrofuran, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, and N, N′-dimethylimidazolidinone are preferable. These polymerization solvents are preferably used after sufficiently dried.

  The total concentration of the monomers in the polymerization solvent is usually 1 to 90% by weight, preferably 5 to 40% by weight.

  The polymerization temperature for the polymerization is usually 0 to 200 ° C, preferably 50 to 120 ° C. The polymerization time is usually 0.5 to 100 hours, preferably 1 to 40 hours.

  The polyarylene having a sulfonic acid ester group obtained by using the monomer (4) can be converted into a polyarylene having a sulfonic acid group by hydrolyzing the sulfonic acid ester group and converting it to a sulfonic acid group. .

As a hydrolysis method,
(1) A method in which polyarylene having a sulfonate group is added to an excess amount of water or alcohol containing a small amount of hydrochloric acid, and the mixture is stirred for 5 minutes or longer. (2) In trifluoroacetic acid, the sulfonate group is added. (3) Method of reacting polyarylene having a temperature of about 80 to 120 ° C. for about 5 to 10 hours (3) 1 to 1 mol of sulfonic acid ester group (—SO ₃ R) in polyarylene having a sulfonic acid ester group A method of adding hydrochloric acid after reacting the polyarylene for about 3 to 10 hours at a temperature of about 80 to 150 ° C. in a solution containing 3 moles of lithium bromide such as N-methylpyrrolidone. Can be mentioned.

  The polyarylene (3) having a sulfonic acid group includes a monomer having no sulfonic acid ester group in the monomer (4) represented by the general formula (4), and an oligomer represented by the general formula (5) ( It is also possible to synthesize a polyarylene copolymer in advance by copolymerization with 5) and sulphonate the polyarylene copolymer. In this case, after producing a polyarylene having no sulfonic acid group by a method according to the above synthesis method, a sulfonic acid group is introduced into the polyarylene having no sulfonic acid group using a sulfonating agent. A polyarylene (3) having a group can be obtained.

  The introduction of the sulfonic acid group is not particularly limited, and can be performed by a general method. For example, the polyarylene having no sulfonic acid group may be prepared by using a known sulfonating agent such as sulfuric anhydride, fuming sulfuric acid, chlorosulfonic acid, sulfuric acid or sodium hydrogen sulfite in the absence of a solvent or in the presence of a solvent. Sulfonic acid groups can be introduced by sulfonation under conditions [Polymer Preprints, Japan, Vol.42, No.3, p.730 (1993); Polymer Preprints, Japan, Vol.43, No.3 , p. 736 (1994); Polymer Preprints, Japan, Vol. 42, No. 7, p. 2490-2492 (1993)].

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

  The amount of the sulfonic acid group in the polyarylene (3) having a sulfonic acid group produced by the method as described above is usually 0.3 to 5 meq / g, preferably 0.5 to 3 meq / g, more preferably 0. .8 to 2.8 meq / g. If it is less than 0.3 meq / g, the proton conductivity is low and not practical. On the other hand, if it exceeds 5 meq / g, the water resistance may be significantly lowered.

  The amount of the sulfonic acid group can be adjusted, for example, by changing the type, usage ratio, and combination of the monomer (4) and the oligomer (5).

  The molecular weight of the polyarylene having a sulfonic acid group thus obtained is 10,000 to 1,000,000, preferably 20,000 to 800,000 in terms of polystyrene-reduced weight average molecular weight by gel permeation chromatography (GPC). When the weight average molecular weight is less than 10,000, the coating film has insufficient coating properties such as cracks in the molded film, and there is a problem in strength properties. On the other hand, if it exceeds 1,000,000, there are problems such as insufficient solubility, high solution viscosity, and poor processability.

<Second polymer>
The second polymer that can be used in the present invention is not particularly limited as long as it is a polymer having a structure rich in bending castability and having a sulfonic acid group. A polymer having a structure rich in bending castability is -O- in the main chain at a ratio of 0.5 or more to one phenylene group,
-S -, - CO -, - CONH -, - COO -, - SO- and -SO ₂ - and the like are those which contain, for example, polyphenylene, polyether, polyazole, polyimide, polyarylene sulfides, polysulfones , Polyethersulfone, polyetheretherketone, polyetherimide, polyphenylene sulfide, polyphenylene oxide and the like. Among these, sulfonated polyether polymers such as polyphenylene oxide, polyetheretherketone and polyethersulfone can be mentioned.

  The polymer having a structure rich in bending castability may be a homopolymer or a copolymer, and can be produced by a known production method. In addition, sulfonation of the polymer having a structure rich in bending castability can be performed in the same manner as the first polymer.

In addition, by mixing the second polymer having a structure rich in bending castability as described above and having a sulfonic acid group, and the first polymer having a relatively rigid structure, The rigidity can be relaxed and the adhesion between the conductive film and the electrode can be improved.

The second polymer has an ion exchange capacity (which is a measure of sulfonation) of 1.0 to 2.5 meq / g, preferably 1.0 to 2.0 meq / g. When the ion exchange capacity is less than 1.0 meq / g, the ion conductivity may be insufficient, and 2.
When it exceeds 5 meq / g, the mechanical strength, the thermal decomposition resistance, the high temperature resistance, the high humidity resistance and the like may be insufficient.

<Polymer composition>
In the polymer composition of the present invention, the content of the sulfonated polyarylene polymer (first polymer) is 30 to 95% by weight, preferably 50 to 95% by weight, more preferably 70 to 90% by weight. The content of the second polymer is 70 to 5% by weight, preferably 50 to 5% by weight, more preferably 30 to 10% by weight. The total content of the first polymer and the second polymer is 100% by weight.

  When the content of the first polymer is less than 30 parts by weight, the ionic conductivity of the composite polymer film becomes insufficient, the thermal stability and the chemical stability may be inferior, and when it exceeds 95 parts by weight, Due to the rigidity of the sulfonated polyarylene polymer itself, the flexibility of the composite membrane may be insufficient, and the adhesion between the electrode and the composite membrane may be poor.

  The polymer composition of the present invention is mainly composed of the first polymer and the second polymer (hereinafter also referred to as polymer component), but an additive or the like is added as necessary. May be.

  For example, the polymer composition of the present invention may be used by containing an anti-aging agent, preferably a hindered phenol compound having a molecular weight of 500 or more. By containing the anti-aging agent, durability as an electrolyte Can be further improved.

Examples of hindered phenol compounds that can be used in the present invention include triethylene glycol-bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate] (trade name: IRGANOX 245), 1,6-hexanediol-bis [3- (3.5
-Di-t-butyl-4-hydroxyphenyl) propionate] (trade name: IRGANOX 259
) 2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di-t-butylanilino) -3,5-triazine (trade name: IRGANOX 565), pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] (trade name: IRGANOX 1010), 2,2-thio-diethylenebis [3- (3,5-di-t-butyl -4
-Hydroxyphenyl) propionate] (trade name: IRGANOX 1035), octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate) (trade name: IRGANOX
1076), N, N-hexamethylenebis (3,5-di-tert-butyl-4-hydroxy-hydrocinnamamide) (IRGAONOX 1098), 1,3,5-trimethyl-2,4,6-tris ( 3,5-di-tert-butyl-4-hydroxybenzyl) benzene (trade name: IRGANOX 1330), tris- (3,5-di-tert-butyl-4-hydroxybenzyl) -isocyanurate (trade name: IRGANOX 3114) 3,9-bis [2- [3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy] -1,1-dimethylethyl] -2,4,8,10 -Tetraoxaspiro [5.5] undecane (trade name: Sumilizer GA-80).

  The hindered phenol compound is preferably used in an amount of 0.01 to 10 parts by weight with respect to 100 parts by weight of the composition.

<Composite membrane>
The composite membrane (proton conductive membrane) of the present invention is composed of the above polymer composition, and the method for producing the composite membrane is not particularly limited. For example, the above polymer component is dissolved in an organic solvent and homogenized. And a casting method in which the solution is cast on a substrate and then formed into a film, or a method of producing a film by extrusion after mixing and melting the polymer components. It is done.

  When producing a film by a casting method, it is desirable to use a common solvent for the polymer component as the organic solvent. For example, N-methyl-2-pyrrolidone, methanol, tetrahydrofuran, cyclohexanone, dimethyl sulfoxide, N, N-dimethylformamide, N, N-dimethylacetamide, γ-butyrolactone, ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, ethylene glycol methyl ethyl Ether, ethylene glycol monoethyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, diethylene glycol monomethyl ether, diethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol methyl ether Acetate, propylene glycol ethyl ether acetate, toluene, xylene, methyl amyl ketone, 4-hydroxy-4-methyl-2-pentanone, ethyl 2-hydroxypropionate, methyl 2-hydroxy-2-methylpropionate, 2-hydroxy- Ethyl 2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-2-methylbutanoate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, 3-methoxypropion Examples include ethyl acid, methyl lactate, ethyl lactate, chloroform, and methylene chloride. These may be used alone or as a mixed solvent in which two or more are mixed. Among these, N-methyl-2-pyrrolidone, methanol, N, N-dimethylformamide, ethyl carbitol and methyl carbitol are preferable.

  Moreover, when performing casting, the solid content concentration of the solution in which the polymer component is dissolved in the organic solvent, that is, the ratio of the polymer component is 3 to 40% by weight, preferably 5 to 35% by weight. If it is less than 3% by weight, a coating film having a sufficient thickness may not be obtained. On the other hand, if it exceeds 40% by weight, it may not be sufficiently cast and a uniform coating film may not be obtained.

  As a substrate used in the casting method, a polyethylene terephthalate (PET) film, a polybutylene terephthalate (PBT) film, a nylon 6 film, a nylon 6,6 film, a polypropylene film, a plastic film such as a polycarbonate film, and a glass plate are used. Preferably, a PET film or a glass plate is used.

  The thickness of the plastic film (plate) used as the substrate is usually 50 to 250 μm, preferably 75 to 200 μm, and the thickness of the glass plate is usually 1 to 5 mm.

  After film formation by the casting method, the composite film of the present invention is obtained by heating and drying at room temperature to 200 ° C., preferably 50 to 150 ° C., for 5 to 180 minutes, preferably 5 to 120 minutes. Drying can be performed under conditions of normal pressure to vacuum. Further, the heating may be performed by sequentially raising the temperature.

In producing the composite film of the present invention, the composite film being formed on the substrate or the obtained composite film may be irradiated with an electron beam to be cured. The method of irradiating the composite film with the electron beam is not particularly limited, but it is preferable to perform the method under the following conditions, for example.
(i) Atmosphere: nitrogen, argon or vacuum, more preferably under nitrogen atmosphere
(ii) Temperature: 20 to 450 ° C., more preferably room temperature to the glass transition temperature of the polymer component
(iii) Electron dose: 5 to 200 Mrad, more preferably 10 to 150 Mrad
When electron beam irradiation is performed in a nitrogen, argon or vacuum atmosphere as described above, the composite film is not oxidized, and sufficient heat resistance and durability can be obtained. Although there will be no restriction | limiting in particular if temperature is 20-450 degreeC, If it carries out at the glass transition temperature of a polymer component, or several tens of degrees C higher than this, it can harden more efficiently. When the electron dose is in the range of 5 to 200 Mrad, the curing reaction can proceed without causing decomposition of the sulfonated product of polyarylene. If it is less than 5 Mrad, the irradiation energy required for crosslinking may not be obtained, and if it exceeds 200 Mrad, a part of the polymer may be decomposed.

  The dry film thickness of the composite membrane (proton conducting membrane) obtained using the polymer composition of the present invention is usually 10 to 150 μm, preferably 20 to 80 μm.

  The composite membrane (proton conducting membrane) of the present invention has a proton conductivity because the sulfonated polyarylene polymer and the polymer having a structure rich in bending castability are combined through liquid homogenization. Without damaging, it is excellent in strength properties, toughness, adhesion to a substrate, hot water resistance, and the like, compared to a conductive membrane made only of sulfonated polyarylene.

  Therefore, the composite membrane of the present invention is used for, for example, an electrolyte for a primary battery, an electrolyte for a secondary battery, a polymer solid 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 as a proton conducting membrane.

〔Example〕
EXAMPLES Hereinafter, although this invention is demonstrated further more concretely based on an Example, this invention is not limited to these Examples.

  The sulfonic acid equivalent, molecular weight, tensile strength, elastic modulus, film folding resistance, water absorption, hot water resistance, proton conductivity, and adhesion were determined as follows.

1. Sulfonic acid equivalent The polymer having the sulfonic acid group was washed with water until the water was neutral, thoroughly washed with water except for free remaining acid, dried, weighed a predetermined amount, THF / Phenolphthalein dissolved in a mixed solvent of water was used as an indicator, titration was performed using a standard solution of NaOH, and the sulfonic acid equivalent was determined from the neutralization point.

2. Measurement of Molecular Weight The molecular weight of polyarylene having no sulfonic acid group was determined by GPC using polystyrene (THF) as a solvent and the molecular weight in terms of polystyrene. The molecular weight of polyarylene having a sulfonic acid group was determined by GPC using polystyrene as a molecular weight using N-methyl-2-pyrrolidone (NMP) to which lithium bromide and phosphoric acid were added as a solvent.

3. Tensile strength The tensile strength was measured at room temperature using a No. 2 type test piece of a film obtained according to JIS K7127.

4). Elastic modulus The elastic modulus was calculated from the initial inclination of the stress-strain curve measured in the tensile test.

5). Film Folding Resistance Using a MIT folding resistance tester (manufactured by Uesima), measurement was performed under the conditions of 166 bendings / minute, a load of 200 g, and a bending deformation angle of 135 °.

6). Water absorption The film was immersed in distilled water at room temperature for 1 hour, and was determined from the change in weight before and after immersion.

7). Hot Water Resistance of Film Using a pressure cooker, the film was immersed in hot water at 120 ° C. for 24 hours, and the retention rate was determined from the change in weight before and after the immersion.

8). Measurement of proton conductivity A film sample having a diameter of 13 mm placed under 100% relative humidity is sandwiched between platinum electrodes, enclosed in a sealed cell, and frequency is 5 to 13 MHz and an applied voltage is 12 mV using an impedance analyzer (HYP4192A). The absolute value and phase angle of the cell impedance were measured at temperatures of 20 ° C., 50 ° C., and 100 ° C. The obtained data was subjected to complex impedance measurement using a computer at an oscillation level of 12 mV, and proton conductivity was calculated.

9. Adhesiveness The obtained polymer was dissolved in a solution of THF / water = 80/20 (weight ratio) to 15% by weight and applied to various substrates using an applicator, and then at 80 ° C. for 2 hours. It dried with the drier and made it the evaluation sample. The obtained evaluation sample was cut with 11 cutters vertically and horizontally at intervals of 2 mm to make 100 grids, and the number of grids remaining on the substrate when the cellophane tape stuck from above was peeled off evaluated.

[Example 1]
Preparation of first polymer component The polyarylene copolymer having a sulfonic acid group used as the first polymer was synthesized by the following method.

<Preparation of oligomer>
2,2-bis (4-hydroxyphenyl) -1,1,1,3 was added to a 1 L three-necked flask equipped with a stirrer, thermometer, cooling tube, Dean-Stark tube, and three-way cock for introducing nitrogen. , 3,3-hexafluoropropane (bisphenol AF) 67.3 g (0.20 mol) 4,4′-dichlorobenzophenone (4,4′-DCBP) 60.3 g (0.24 mol), potassium carbonate 71.9 g (0.52 mol), N, N-dimethylacetamide (DMAc) 300 m
L and 150 mL of toluene were taken and heated in an oil bath under a nitrogen atmosphere and reacted at 130 ° C. with stirring. When water produced by the reaction was azeotroped with toluene and reacted while being removed from the system with a Dean-Stark tube, almost no water was produced in about 3 hours. Thereafter, most of the toluene was removed while gradually raising the reaction temperature from 130 ° C. to 150 ° C., and the reaction was continued at 150 ° C. for 10 hours. Then, 10.0 g (0.040 mol) of 4,4′-DCBP was added, The reaction was further continued for 5 hours. The resulting reaction solution was allowed to cool, and then the by-product inorganic compound precipitate was removed by filtration, and the filtrate was put into 4 L of methanol. The precipitated product was separated by filtration, collected, dried, and dissolved in 300 mL of tetrahydrofuran. This was reprecipitated in 4 L of methanol to obtain 95 g (yield 85%) of the target compound.

The weight average molecular weight (Mw) in terms of polystyrene determined by GPC (THF solvent) of the obtained compound was 11,200. The obtained compound was soluble in THF, NMP, DMAc, sulfolane and the like, and had a glass transition temperature (Tg) of 110 ° C. and a thermal decomposition temperature of 498 ° C.

  The obtained compound was an oligomer represented by the formula (I) (hereinafter referred to as “BCPAF oligomer”).

<Preparation of Polyarylene Copolymer with Neopentyl Group as Protecting Group (PolyAB-SO ₃ neo-Pe)>
4- [4- (2,5-dichlorobenzoyl) phenoxy] benzenesulfonic acid neo was added to a 1 L three-necked flask equipped with a stirrer, thermometer, condenser, Dean-Stark tube, and three-way cock for introducing nitrogen. -Pentyl (A-SO ₃ neo-Pe) 39.58 g (98.64 mmol), BCPAF oligomer (Mw = 11200) 15.23 g (1.36 mmol), Ni (PPh ₃ ) ₂ Cl ₂ 1.67 g (2 .55 mmol), 10.49 g (40 mmol) of PPh ₃ , 0.45 g ( ₃ mmol) of NaI, 15.69 g (240 mmol) of zinc dust and 390 mL of dry NMP were added under nitrogen. The reaction system is heated with stirring (finally 75 ° C.
The mixture was allowed to react for 3 hours. The polymerization reaction solution was diluted with 250 mL of THF, stirred for 30 minutes, filtered using Celite as a filter aid, and the filtrate was poured into a large excess of 1500 mL of methanol to coagulate. The coagulum was collected by filtration, air-dried, redissolved in THF / NMP (200/300 mL each), and coagulated with 1500 mL of a large excess of methanol. After air drying, 47.0 g (yield 99%) of a copolymer (PolyAB-SO ₃ neo-Pe) composed of a sulfonic acid derivative protected with a target yellow fibrous neopentyl group was obtained by heat drying. As for the molecular weight by GPC, the number average molecular weight (Mn) was 47,600, and Mw was 159,000.

<Preparation of polyarylene copolymer (II) having sulfonic acid group>
5.1 g of the obtained copolymer (PolyAB-SO ₃ neo-Pe) was dissolved in 60 mL of NMP and heated to 90 ° C. A mixture of 50 mL of methanol and 8 mL of concentrated hydrochloric acid was added to the reaction system at one time. While in suspension, the reaction was allowed to proceed for 10 hours under mild reflux conditions. A distillation apparatus was installed, and excess methanol was distilled off to obtain a light green transparent solution. This solution was poured into a large amount of water / methanol (1: 1 weight ratio) to solidify the polymer, and then the polymer was washed with ion-exchanged water until the pH of the washing water became 6 or more. From the IR spectrum of the polymer thus obtained and the quantitative analysis of the ion exchange capacity, it was found that the sulfonic acid ester group (—SO ₃ R ^a ) was quantitatively converted to the sulfonic acid group (—SO ₃ H). .

  The obtained polyarylene copolymer having a sulfonic acid group had a molecular weight of GPC of Mn of 53,200, Mw of 185,000, and a sulfonic acid equivalent of 1.9 meq / g.

  A 10% by weight N-methylpyrrolidone solution of the polyarylene copolymer (II) having a sulfonic acid group thus obtained was used as the first polymer component.

Preparation of Second Polymer Component 50 g of polyetheretherketone (PEEK) was placed in a 1000 ml separable flask equipped with a stirrer and a thermometer, and 500 ml of 98% sulfuric acid was added, while maintaining the internal temperature at 25 ° C. The mixture was stirred for 24 hours under a nitrogen stream. The obtained solution was poured into a large amount of ion-exchanged water to precipitate a polymer, and then the polymer was repeatedly washed until the washing water had a pH of 5. The resulting precipitate was dried to obtain 56 g (95%) of a sulfonated polyetheretherketone. The sulfonated equivalent of the sulfonated polyetheretherketone obtained was 1.8 meq / g.

A 10% by weight N-methylpyrodrin solution of the sulfonated polyetheretherketone thus obtained was used as the second polymer component. .

<Production and evaluation of composite membrane>
The solution of the first polymer component and the solution of the second polymer component are blended so as to have a solid composition ratio of 75/25, and the blended solution is stirred and mixed at room temperature. A homogeneous solution was prepared. The obtained homogeneous solution was a pale yellow transparent solution. At this time, the solid content concentration of the homogeneous solution was 10% by weight.

  The obtained homogeneous solution (solution composition) was cast on a glass substrate using a doctor blade, dried at 80 ° C. for 15 minutes, 100 ° C. for 15 minutes, 150 ° C. for 30 minutes, and 180 ° C. for 30 minutes. A flexible composite film (composite film) having a film thickness of 30 μm was obtained. The evaluation results of the obtained composite membrane are shown in Table 1.

[Example 2]
In Example 1, instead of the polyarylene copolymer (II) having a sulfonic acid group used as the first polymer, a polyarylene copolymer having a sulfonic acid group synthesized by the following method ( A composite membrane was obtained in the same manner as in Example 1 except that III) was used. The evaluation results of the obtained composite membrane are shown in Table 1.

<Preparation of polyarylene copolymer>
28.1 g (2.5 mmol) of BCPAF oligomer obtained in Example 1 35.9 g of 2,5-dichloro-4 ′-(4-phenoxy) phenoxybenzophenone (DCPPB)
(82.5 mmol), bis (triphenylphosphine) nickel dichloride 1.67
g (2.6 mmol), 1.66 g (11.1 mmol) of sodium iodide, 8.92 g (34.0 mmol) of triphenylphosphine and 13.3 g (204 mmol) of zinc dust were placed in a flask and purged with dry nitrogen. 160 ml of N-methyl-2-pyrrolidone was added, and the mixture was heated to 80 ° C. and stirred for 4 hours for polymerization. The polymerization solution was diluted with 450 mL of THF, and this was poured into hydrochloric acid / methanol (500/4500 mL, respectively) to coagulate. After repeating the methanol washing of the solidified product, a solution dissolved in 1000 mL of THF was added to 5000 mL of methanol to cause reprecipitation. The obtained precipitate was vacuum-dried to obtain 51.0 g (90%) of the target copolymer. The molecular weight of the obtained copolymer by GPC was 38,900 for Mn and 160,000 for Mw.

<Preparation of polyarylene copolymer (III) having sulfonic acid group>
50 g of the obtained copolymer was put into a 1000 ml separable flask equipped with a stirrer and a thermometer, 500 ml of sulfuric acid with a concentration of 98% was added, and the mixture was stirred for 24 hours under a nitrogen stream while keeping the internal temperature at 25 ° C. The obtained solution is poured into a large amount of ion-exchanged water to precipitate a polymer, and the precipitate is repeatedly washed until the pH of the washing water becomes 5, and then dried to obtain 56 g (95%) of sulfone. A polyarylene copolymer having an acid group was obtained.

The resulting polyarylene copolymer having a sulfonic acid group has a Mn of 45,50.
0, Mw was 176,000, and the sulfonic acid equivalent was 2.1 meq / g.

[Comparative Example 1]
A film having a thickness of 30 μm was obtained using only the first polymer component comprising the polyarylene copolymer (II) having a sulfonic acid group used in Example 1. The evaluation results of the obtained film are shown in Table 1.

[Comparative Example 2]
The first comprising the polyarylene copolymer (III) having a sulfonic acid group used in Example 2
A film having a film thickness of 30 μm was obtained using only the polymer component. The evaluation results of the obtained film are shown in Table 1.

[Comparative Example 3]
A film having a thickness of 30 μm was obtained using only the second polymer component comprising the sulfonated polyetheretherketone used in Example 1. The evaluation results of the obtained film are shown in Table 1.

Claims (4)

A sulfonated polyarylene polymer having a sulfonic acid group composed of a repeating unit represented by the following general formula (1) and a repeating unit represented by the following general formula (2);
A polymer composition comprising a polymer having a structure rich in bend castability and having a sulfonic acid group.

(In the formula, A represents a divalent electron-withdrawing group, B represents a divalent electron-donating group or a direct bond, Ar represents an aromatic group having a substituent represented by —SO ₃ H, m represents an integer of 0 to 10, n represents an integer of 0 to 10, and k represents an integer of 1 to 4.)

(Wherein R ^{1 to} R ⁸ may be the same as or different from each other, and are at least one selected from the group consisting of a hydrogen atom, a fluorine atom, an alkyl group, a fluorine-substituted alkyl group, an allyl group, an aryl group, and a cyano group) W represents a divalent electron-withdrawing group or a single bond, T represents a single bond or a divalent organic group, p represents a positive integer of 2 or more when T is —O—, If it is other than -O-, it represents a positive integer of 1 or more.)   2. The polymer composition according to claim 1, wherein the polymer having a structure rich in bending castability and having a sulfonic acid group is a sulfonated polyether-based polymer.   3. The polymer composition according to claim 1, wherein the content of the sulfonated polyarylene polymer is 30 to 95% by weight based on the entire composition.   A composite film comprising the polymer composition according to claim 1.