JP2003261653A - Process for preparing sulfonic acid group-containing polymer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a process for preparing a sulfonic acid group-containing polymer which may be used for electrolytes for primary or secondary batteries, polymer solid electrolytes for fuel cells, display devices, various sensors, signal transmission media, solid capacitors, ion exchange membranes, etc. <P>SOLUTION: In the process for preparing the sulfonic acid group-containing polymer, upon sulfonating a polyarylene polymer, ≥10 ml sulfuric acid with a concentration of 95.5-97.4 wt.% is used against 1 g polymer, and a reaction liquid comprising the polyarylene polymer and sulfuric acid is maintained at ≥20°C. Alternatively, in the process for preparing the sulfonic acid group- containing polymer, upon sulfonating a polyarylene polymer, ≥3 ml sulfuric acid with a concentration of ≥97.5 wt.% is used against 1 g polymer, and a reaction liquid comprising the polyarylene polymer and sulfuric acid is maintained at ≤25°C. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an electrolyte for a primary battery, an electrolyte for a secondary battery, a polymer solid electrolyte for a fuel cell,
The present invention relates to a method for producing a sulfonic acid group-containing polymer that can be used in display devices, various sensors, signal transmission media, solid capacitors, ion exchange membranes and the like.

[0002]

2. Description of the Related Art As a method for producing a sulfonic acid group-containing polymer, for example, Polymer Preprints, Japan, vol. 42, No.
3, p.730 (1993); Polymer Preprints, Japan, vol.42,
No.3, p.736 (1994); Polymer Preprints, Japan, vol.4
2, No. 7, p. 2490 (1993). Etc., a polymer having no sulfonic acid group is treated with sulfuric anhydride, fuming sulfuric acid,
It is known to sulfonate using a sulfonating agent such as chlorosulfonic acid, sulfuric acid and sodium hydrogen sulfite. In particular, the method of sulfonation using sulfuric acid is generally used as a simple sulfonation method. However, when this method is used, depending on the reaction conditions, there are problems that the solution viscosity of the reaction solution is abnormally high, it is difficult to stir and handle, and it is difficult to control the amount of sulfonic acid groups introduced. It was If the introduced amount of the sulfonic acid group is too high, although the proton conductivity is improved, there is a problem that the mechanical strength of the obtained sulfonic acid group-containing polymer is significantly impaired, and the material becomes inferior in toughness. .

[0003]

The present invention has been made against the background of conventional technical problems, and it is possible to control the solution viscosity during the sulfonation reaction within an appropriate range and to control the amount of sulfonic acid groups introduced. It is to provide a method for producing a sulfonic acid group-containing polymer that can be easily controlled.

[0004]

In the present invention, when a polyarylene polymer is sulfonated, a concentration of 95.5 to 97.
A method for producing a sulfonic acid group-containing polymer, characterized in that 10 ml or more of 4% by weight of sulfuric acid is used for 1 g of the polymer, and the reaction is carried out in a reaction solution at 20 ° C. or more, and a polyarylene polymer is sulfonated. When using, sulfuric acid having a concentration of 97.5% by weight or more is used in an amount of 3 ml or more per 1 g of the polymer
The present invention provides a method for producing a sulfonic acid group-containing polymer, which is carried out in a reaction solution at 25 ° C or lower.

The polyarylene polymer in the present invention is a monomer (A) represented by the following general formula (A).
And a polymer obtained by reacting at least one monomer (B) selected from the following general formulas (B-1) to (B-4) with each other.

(A)

[Chemical 1] Wherein (A), R~R 'may be the same or different from each other, a halogen atom or -OSO ₂ except fluorine atom
Z represents a group represented by Z (wherein Z represents an alkyl group, a fluorine-substituted alkyl group or an aryl group). 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 p.
-A tolyl group and the like. R ^{1 to} R ⁸ may be the same or different and each represents 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 and an aryl group. . As the alkyl group, a methyl group, an ethyl group,
Examples thereof include a propyl group, a butyl group, an amyl group and a hexyl group, with a methyl group and an ethyl group being preferred. Examples of the fluorine-substituted alkyl group include trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluorobutyl group, perfluoropentyl group, perfluorohexyl group, trifluoromethyl group, pentafluoroethyl group. Are preferred. Examples of the allyl group include a propenyl group, and examples of the aryl group include a phenyl group and a pentafluorophenyl group. X represents a divalent electron-withdrawing group, and as the electron-withdrawing group, for example, -CO-, -CONH-,-(C
F ₂ ) _p- (where p is an integer of 1 to 10), -C
_{(CF 3) 2 -, -} COO -, - SO -, - SO 2 - , and the like. The electron-withdrawing group is Hammett (Ha
mmett) When the substituent constant is m-position of the phenyl group, 0.0
A group having a value of 6 or more and 0.01 or more in the case of the p-position. Y represents a divalent electron-donating group, and examples of the electron-donating group include -O-, -S-, -CH = CH-, -C≡.
C- and the following formula

[Chemical 2] And the like.

N is 0 or a positive integer, and the upper limit is usually 100, preferably 80. Specific examples of the monomer represented by the general formula (A) include 4,4′-dichlorobenzophenone, 4,4′-dichlorobenzanilide, bis (chlorophenyl) difluoromethane, and 2,2.
-Bis (4-chlorophenyl) hexafluoropropane, 4-chlorophenyl-4-chlorophenyl, bis (4-chlorophenyl) sulfoxide, bis (4-chlorophenyl) sulfone, in these compounds, the chlorine atom becomes a bromine atom or an iodine atom. The replaced compound,
Furthermore, compounds in which a halogen atom substituted at the 4-position in these compounds is substituted at the 3-position and the like can be mentioned. Further, specifically as the monomer represented by the above general formula (A),
For example, 4,4'-bis (4-chlorobenzoyl) diphenyl ether, 4,4'-bis (4-chlorobenzoylamino) diphenyl ether, 4,4'-bis (4-chlorophenylsulfonyl) diphenyl ether, 4,4'-bis (4-chlorophenyl) diphenyl ether dicarboxylate, 4,4'-bis [(4-chlorophenyl)-
1,1,1,3,3,3-hexafluoropropyl] diphenyl ether, 4,4′-bis [(4-chlorophenyl)
-1,1,1,3,3,3-hexafluoropropyl] diphenyl ether, 4,4'-bis [(4-chlorophenyl) tetrafluoroethyl] diphenyl ether, in which chlorine atom is changed to bromine atom or iodine atom Examples of the substituted compounds, compounds in which a halogen atom substituted in the 4-position of these compounds is substituted in the 3-position, and compounds in which at least one of the groups substituted in the 4-position of diphenyl ether in these compounds is substituted in the 3-position, and the like. To be

Further, as the monomer represented by the above general formula (A), 2,2-bis [4- {4- (4-chlorobenzoyl) phenoxy} phenyl] -1,1,1,3,3,
3-hexafluoropropane, bis [4- {4- (4-
Chlorobenzoyl) phenoxy} phenyl] sulfone,
And a compound represented by the following formula.

[Chemical 3]

The monomer represented by the above general formula (A) is
For example, it can be synthesized by the following method. First, in order to convert the bisphenol linked with an electron-withdrawing group into the corresponding alkali metal salt of bisphenol, dielectrics such as N-methyl-2-pyrrolidone, N, N-dimethylacetamide, sulfolane, diphenylsulfone, and dimethyl sulfoxide are used. Add an alkali metal such as lithium, sodium and potassium, an alkali metal hydride, an alkali metal hydroxide and an alkali metal carbonate in a highly polar solvent. Usually, the alkali metal is reacted with the hydroxyl group of phenol with a slight excess, and usually 1.1 to 2 times equivalent is used. Preferably, it is 1.2 to 1.5 times equivalent. At this time, a solvent azeotropic with water such as benzene, toluene, xylene, hexane, cyclohexane, octane, chlorobenzene, dioxane, tetrahydrofuran, anisole, and phenetole is allowed to coexist, and fluorine or chlorine activated by an electron-withdrawing group is used. An aromatic dihalide compound substituted with a halogen atom of, for example, 4,4′-difluorobenzophenone, 4,4′-dichlorobenzophenone, 4,4′-chlorofluorobenzophenone, bis (4
-Chlorophenyl) sulfone, bis (4-fluorophenyl) sulfone, 4-fluorophenyl-4'-chlorophenyl sulfone, bis (3-nitro-4-chlorophenyl) sulfone, 2,6-dichlorobenzonitrile, 2,
6-difluorobenzonitrile, hexafluorobenzene, decafluorobiphenyl, 2,5-difluorobenzophenone, 1,3-bis (4-chlorobenzoyl) benzene and the like are reacted. From the viewpoint of reactivity, a fluorine compound is preferable, but in consideration of the following aromatic coupling reaction, it is necessary to assemble the aromatic nucleophilic substitution reaction so that the terminal is a chlorine atom. The active aromatic dihalide is 2 to 4 times mol, preferably 2.
It is the use of 2-2.8 times mole. Before the aromatic nucleophilic substitution reaction, an alkali metal salt of bisphenol may be used in advance. The reaction temperature is 60 ° C to 300 ° C, preferably 8
It is in the range of 0 ° C to 250 ° C. Reaction time is 15 minutes to 10 minutes
It is 0 hour, preferably 1 hour to 24 hours. The most preferable method is the following formula

[Chemical 4] (In the formula, Y is as defined for the general formula (A).) As the active aromatic dihalide represented by the formula (A), a chlorofluoro compound having one halogen atom with different reactivity is used, and a fluorine atom is preferred. Then, nucleophilic substitution reaction with phenoxide occurs, which is convenient for obtaining the desired activated terminal chloro compound.

Alternatively, as described in Japanese Patent Application Laid-Open No. 2-159, there is a method for synthesizing a flexible compound comprising a desired electron-withdrawing group and electron-donating group by combining a nucleophilic substitution reaction and an electrophilic substitution reaction. Specifically, an aromatic bishalide activated by an electron-withdrawing group, for example, bis (4-chlorophenyl) sulfone is subjected to a nucleophilic substitution reaction with phenol to obtain a bisphenoxy-substituted product. Then, the substituted compound is subjected to, for example, a Friedel-Crafts reaction with 4-chlorobenzoic acid chloride to obtain the target compound. The compounds exemplified above can be applied to the aromatic bishalide activated by the electron-withdrawing group used here. 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 use an alkali metal salt for the phenol substitution reaction, and as the usable alkali metal compound, the compounds exemplified above can be used. The amount used is 1.2 to 2 times mol per mol of phenol.
In the reaction, the above polar solvent or an azeotropic solvent with water can be used. A bisphenoxy compound is reacted with chlorobenzoic acid chloride as an acylating agent in the presence of an activator of a Friedel-Crafts reaction of a Lewis acid such as aluminum chloride, boron trifluoride, zinc chloride and the like. Chlorobenzoic acid chloride is 2 relative to the bisphenoxy compound.
-4 times mol, preferably 2.2 to 3 times mol. Friedel-Crafts activator is based on 1 mol of an active halide compound such as chlorobenzoic acid as an acylating agent.
1. Use 1-2 times equivalent amount. The reaction time is in the range of 15 minutes to 10 hours, and the reaction temperature is in the range of -20 ° C to 80 ° C. The solvent used is inert to the Friedel-Crafts reaction,
Chlorobenzene, nitrobenzene, etc. can be used.

In the general formula (A), the monomer (A) in which n is 2 or more is, for example, bisphenol serving as a source of etheric oxygen which is the electron donating group B in the general formula (A), Electron-withdrawing group A,> C = O, -S
O ₂ − and / or> C (CF ₃ ) ₂ in combination, specifically 2,2-bis (4-hydroxyphenyl) -1,1,
Alkali metal salts of bisphenol such as 1,3,3,3-hexafluoropropane, 2,2-bis (4-hydroxyphenyl) ketone, 2,2-bis (4-hydroxyphenyl) sulfone and excess 4,4 -Substitution reaction with an active aromatic halogen compound such as dichlorobenzophenone and bis (4-chlorophenyl) sulfone, in the presence of a polar solvent such as N-methyl-2-pyrrolidone, N, N-dimethylacetamide and sulfolane. It is obtained by sequentially polymerizing according to the synthetic method of. Examples of such a monomer (A) include compounds represented by the following formula.

[0012]

[Chemical 5]

[0013]

[Chemical 6]

[0014]

[Chemical 7] In the above, n is 2 or more, preferably 2 to 100.

Next, the monomers represented by the general formulas (B-1) to (B-4) will be described. (B-1)

[Chemical 8] In the formula, R and R ′ may be the same as or different from each other and represent the same groups as R and R ′ in the general formula (A). R ^{9 to} R ¹⁵ may be the same or different,
At least one atom or group selected from the group consisting of hydrogen atom, fluorine atom and alkyl group is shown. R ⁹ ~
Examples of the alkyl group represented by R ¹⁵ include the same as the alkyl groups represented by R ^{1 to} R ⁸ in the general formula (A).
m represents 0, 1 or 2. X is the above general formula (A)
Represents a divalent electron-withdrawing group selected from the same group as shown in. Y represents a divalent electron donating group selected from the same group as that shown as Y in the above general formula (A). W is a phenyl group, a naphthyl group or the following formula (C-
At least one group selected from the group consisting of the groups represented by 1) to (C-3) is shown.

From the top, (C-1), (C-2), (C-
3)

[Chemical 9] In the formula, A represents an electron-donating group or a single bond. Examples of the electron donating group include a divalent electron donating group selected from the same group as that shown as Y in the above general formula (A). R ¹⁶ and R ¹⁷ represent an atom or a group selected from the group consisting of a hydrogen atom, an alkyl group and an aryl group. R
Examples of the alkyl group and aryl group represented by ¹⁶ and R ¹⁷ include those similar to the alkyl group and aryl group represented by R ^{1 to} R ⁸ in the general formula (A). R ¹⁸ ~ R
²⁶ may be the same or different and each represents at least one atom or group selected from the group consisting of hydrogen atom, fluorine atom and alkyl group. q represents 0 or 1. Examples of the monomer represented by the general formula (B-1) include compounds represented by the following formula.

[Chemical 10] More specifically, examples of the compound represented by the general formula (B-1) include compounds represented by the following formula.

[0017]

[Chemical 11]

[0018]

[Chemical 12]

Further, in the above compounds, compounds in which chlorine atom is replaced with bromine atom or iodine atom can be exemplified.

From above (B-2), (B-3), (B-
4)

[Chemical 13]

In the formulas (B-2) to (B-4), R and R'may be the same or different from each other and represent the same groups as R and R'in the general formula (A). R ²⁷ ~ R ³⁴
May be the same or different and each represents a hydrogen atom, a fluorine atom, an alkyl group, a fluorine-substituted alkyl group, an aryl group or a group represented by the following general formula (D).

(D)

[Chemical 14] In formula (D), R ^{35 to} R ⁴³ may be the same or different and each represents a hydrogen atom, a halogen atom, an alkyl group or a fluorine-substituted alkyl group. The alkyl group and fluorine-substituted alkyl group represented by R ^{27 to} R ³⁴ and R ^{35 to} R ⁴³ include R ^{1 to} R ⁸
And the same groups as the alkyl group and the fluorine-substituted alkyl group represented by. Examples of the aryl group represented by R ^{27 to} R ³⁴ include the same groups as the aryl group represented by R ^{1 to} R ⁸ . X represents a divalent electron-withdrawing group selected from the same group as that shown as X in the above general formula (A). Y represents a divalent electron donating group selected from the same group as that shown as Y in the above general formula (A).

Specific examples of the monomer represented by the above general formula (B-2) include p-dichlorobenzene and p-dichlorobenzene.
Dimethylsulfonyloxybenzene, 2,5-dichlorotoluene, 2,5-dimethylsulfonyloxybenzene, 2,5-dichloro-p-xylene, 2,5-dichlorobenzotrifluoride, 1,4-dichloro-2, Three, five,
Examples thereof include 6-tetrafluorobenzene, and compounds in which a chlorine atom is replaced with a bromine atom or an iodine atom in these compounds. Specific examples of the monomer represented by the above general formula (B-3) include, for example, 4,4′-dimethylsulfonyloxybiphenyl, 4,4′-dimethylsulfonyloxy-3,3′-dipropenylbiphenyl,
4,4'-dibromobiphenyl, 4,4'-diiodobiphenyl, 4,4'-dimethylsulfonyloxy-3,3'-dimethylbiphenyl, 4,4'-dimethylsulfonyloxy-3,3'- Difluorobiphenyl, 4,4'-dimethylsulfonyloxy-3,3'5,5'-tetrafluorobiphenyl, 4,4'-dibromooctafluorobiphenyl,
4,4′-dimethylsulfonyloxyoctafluorobiphenyl and the like can be mentioned. Specific examples of the monomer represented by the above general formula (B-4) include m-dichlorobenzene, m-dimethylsulfonyloxybenzene, and 2,
4-dichlorotoluene, 3,5-dichlorotoluene, 2,
6-dichlorotoluene, 3,5-dimethylsulfonyloxytoluene, 2,6-dimethylsulfonyloxytoluene, 2,4-dichlorobenzotrifluoride, 3,5
-Dichlorobenzotrifluoride, 1,3-dibromo-2,4,5,6-tetrafluorobenzene, and compounds in which a chlorine atom is replaced with a bromine atom or an iodine atom in these compounds. Further, as the molecular weight regulator, a halogen compound at one end (excluding fluorine) such as 4-chlorobenzophenone can be used to adjust the molecular weight to a predetermined value.

The polyarylene polymer is obtained by reacting the above-mentioned monomers in the presence of a catalyst, and the catalyst used is a catalyst system containing a transition metal compound.
A transition metal salt and a compound serving as a ligand (hereinafter, referred to as “ligand component”), or a transition metal complex (including a copper salt) in which a ligand is coordinated, and a reducing agent are essential components, Further, 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 chloride,
Palladium compounds such as palladium bromide and palladium iodide; iron compounds such as iron chloride, iron bromide and iron iodide; cobalt compounds such as cobalt chloride, cobalt bromide and cobalt iodide. Of these, nickel chloride and nickel bromide are particularly preferable. Examples of the ligand component include triphenylphosphine, 2,2'-bipyridine, 1,5-cyclooctadiene and 1,3-bis (diphenylphosphino) propane. Of these, triphenylphosphine and 2,2'-bipyridine are preferable. The compound that is the ligand component may be used alone or in combination of two or more.

Further, examples of the transition metal complex having a ligand coordinated include 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, etc. are mentioned. Of these, nickel chloride bis (triphenylphosphine) and nickel chloride (2,2′-bipyridine) are preferable. Examples of the reducing agent that can be used in the above catalyst system include iron, zinc, manganese, aluminum, magnesium, sodium, calcium and the like. Of these, zinc, magnesium and manganese are preferable. These reducing agents can be further activated and used by bringing them into contact with an acid such as an organic acid.

As the "salt" which can be used in the above catalyst system, sodium compounds such as sodium fluoride, sodium chloride, sodium bromide, sodium iodide and sodium sulfate, potassium fluoride, potassium chloride, odor, etc. Examples thereof include potassium compounds such as potassium iodide, 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 such that the transition metal salt or transition metal complex is usually 0.0001 to 10 mol, preferably 0.01 to 10 mol, based on 1 mol of the total of the above monomers.
It is 0.5 mol. If it is less than 0.0001 mol, the polymerization reaction may not proceed sufficiently, while if it exceeds 10 mol, the molecular weight may decrease. When a transition metal salt and a ligand component are used in the catalyst system, the ratio of the ligand component used is usually 0.1 to 100 mol, preferably 1 to 10 mol, based on 1 mol of the transition metal salt. is there. If it is less than 0.1 mol, the catalytic activity may be insufficient, whereas if it exceeds 100 mol, the molecular weight may be lowered. The ratio of the reducing agent used is usually 0.1 to 100 mol, preferably 1 to 10 mol, based on 1 mol of the total amount of the above monomers. If it is less than 0.1 mol, polymerization may not proceed sufficiently, and if it exceeds 100 mol, purification of the resulting polymer may be difficult. Furthermore, when a "salt" is used, its use ratio is usually 0.001 to 100 per 1 mol of the total amount of the above monomers.
The molar amount is preferably 0.01 to 1 mol. 0.001
If it is less than 100 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 the polymerization solvent that can be used include tetrahydrofuran, cyclohexanone, dimethylsulfoxide, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone and γ-butyrolactone. Of these, tetrahydrofuran, N, N-dimethylformamide, N, N-dimethylacetamide,
N-methyl-2-pyrrolidone is preferred. It is preferable to use these polymerization solvents after drying them sufficiently. The total concentration of the above monomers in the polymerization solvent is usually
It is 1 to 90% by weight, preferably 5 to 40% by weight. Moreover, the polymerization temperature at the time of superposition | polymerization is 0-200 degreeC normally, Preferably it is 50-120 degreeC. The polymerization time is usually 0.5 to 100 hours, preferably 1 to 40 hours. Thus, at least one monomer (B) selected from the monomer (A) represented by the general formula (A) and the monomer represented by the general formulas (B-1) to (B-4). By polymerizing, a polymerization solution containing polyarylene is obtained.

Next, in the present invention, a sulfonic acid group is introduced into the above copolymer having no sulfonic acid group using sulfuric acid.

That is, as the reaction conditions for the sulfonation, the copolymer having no sulfonic acid group is reacted with the sulfonating agent in the absence or presence of a solvent. In the present invention, when sulphonating a polymer, when sulfuric acid having a concentration of 95.5 to 97.4% by weight is used, 10 mL or more, preferably 10 to 50 mL, of sulfuric acid is used for 1 g of the polymer. , 20 ° C or higher, preferably 25
The reaction is carried out at -30 ° C for 10-30 hours. Sulfuric acid amount is 10m
If it is less than L, stirring cannot be performed because the viscosity of the reaction solution is too high. The reaction solution of the present invention is composed of the above polymer and sulfuric acid, but if the temperature of the reaction solution is lower than 20 ° C., the sulfonation rate is too slow, so that a target sulfonation equivalent amount of the polymer can be obtained. Have difficulty. Moreover, when using sulfuric acid having a concentration of 97.5% by weight or more when sulfonation of the polymer, 3 ml or more, preferably 3 to 50 mL, is used per 1 g of the polymer, and the temperature of the reaction solution is 25 ° C. Less than,
The reaction is preferably carried out at 5 to 15 ° C for 10 to 30 hours. If the amount of sulfuric acid is less than 3 ml, the solution viscosity is too high and stirring is difficult, and if the reaction temperature exceeds 25 ° C, the sulfonation rate is too fast, so that the sulfonation proceeds too much to obtain the target sulfonation equivalent amount of polymer. Is difficult. In the present invention, it is preferable not to use an organic solvent together during the sulfonation, but it is also possible to use an organic solvent if necessary. In that case, as the solvent that can be used,
For example, hydrocarbon solvents such as n-hexane, ether solvents such as tetrahydrofuran and dioxane, N, N-dimethylacetamide, N, N-dimethylformamide,
In addition to aprotic polar solvents such as dimethyl sulfoxide, halogenated hydrocarbons such as tetrachloroethane, dichloroethane, chloroform and methylene chloride can be used.

The amount of sulfonic acid group in the sulfonated polymer thus obtained is 0.5 to 3 mg / eq.
g, preferably 0.8 to 2.8 milligram equivalents / g. If it is less than 0.5 milliequivalent / g, the proton conductivity does not increase, while if it exceeds 3 milliequivalent / g,
The hydrophilicity is improved and the polymer becomes a water-soluble polymer, or the durability is reduced even if the polymer is not water-soluble. The amount of the sulfonic acid group can be easily adjusted by changing the use ratio of the monomer (A) and the monomer (B), and the type and combination of the monomer (A).

The molecular weight of the thus obtained precursor polymer of the sulfonic acid group-containing copolymer of the present invention before sulfonation is 1 in terms of polystyrene equivalent weight average molecular weight.
It is 10,000 to 500,000, preferably 20,000 to 400,000, and more preferably 50,000 to 300,000. If it is less than 10,000, the coating film properties are insufficient, such as cracks in the molded film, and there is a problem in strength properties. On the other hand, when it exceeds 500,000, the viscosity during the sulfonation reaction becomes high, the handling is difficult, and the processability of the sulfonated polymer becomes poor.

The sulfonic acid group-containing copolymer of the present invention has a molecular weight of 20,000 to 10 in terms of polystyrene equivalent weight average molecular weight.
It is 0,000, preferably 50,000 to 800,000, and more preferably 100,000 to 600,000.

Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

[Examples] Measurement method Equivalent amount of sulfonic acid Rinsing of the obtained sulfonic acid group-containing polymer was washed until the water became neutral, the free residual acid was removed, and the polymer was thoroughly washed with water and dried. A fixed amount was weighed, dissolved in a mixed solvent of THF / water, titrated using phenolphthalein as an indicator and a standard solution of NaOH, and the equivalent amount of sulfonic acid was determined from the neutralization point. Measurement of Molecular Weight The weight average molecular weight of the precursor polymer before sulfonation was determined by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent.
The polystyrene equivalent molecular weight was determined. The molecular weight of the sulfonate is N- with the addition of lithium bromide and phosphoric acid as solvents.
Gel permeation chromatography (GP) using methyl-2-pyrrolidone (NMP) as an eluent
The molecular weight in terms of polystyrene was determined by C). Evaluation of hot water resistance Using NMP as a solvent from sulfonated product, about 50μ
An m-thick cast film was prepared and evaluated by the weight retention rate after being immersed in hot water at 120 ° C. for 24 hours.

[Reference Example: Synthesis of polyarylene] (Preparation of oligomer) Stirrer, thermometer, cooling tube, Dean-S
In a 1-L three-necked flask equipped with a tark tube and a three-way cock for introducing nitrogen, 2.2-bis (4-hydroxyphenyl) -1,
1,1,3,3,3-hexafluoropropane (bisphenol A
F) 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 (DMA
c) Take 300 mL and 150 mL of toluene, and in an oil bath,
The mixture was heated under a nitrogen atmosphere and reacted at 130 ° C. with stirring. When the water produced by the reaction was azeotropically distilled with toluene and the reaction was carried out while removing it out of the system with a Dean-Stark tube, almost no water production was observed in about 3 hours. The reaction temperature was gradually increased from 130 ° C to 150 ° C. Then gradually increase the reaction temperature to 1
Removed most of toluene while raising the temperature to 50 ℃
After continuing the reaction for 10 hours at 4,4'-DCBP 10.0g (0.040
Mol) was added and the reaction was continued for 5 hours. After allowing the obtained reaction solution to cool, the precipitate of the inorganic compound by-produced is removed by filtration,
The filtrate was poured into 4 L of methanol. The precipitated product was separated by filtration, collected, dried and then dissolved in 300 mL of tetrahydrofuran. This was reprecipitated in 4 L of methanol to obtain 95 g of the desired compound (yield 85%). GPC of the obtained polymer
The polystyrene reduced number average molecular weight determined by (THF solvent) was 4,200, and the weight average molecular weight was 8,300. The obtained polymer was soluble in THF, NMP, DMAc, sulfolane, etc., and had a Tg of 110 ° C and a thermal decomposition temperature of 498 ° C. The resulting polymer has the formula (I):

[Chemical 15] It was presumed to have a structure represented by (I), and the average value of n was determined to be 7.8 from the structure and the above number average molecular weight.

(Synthesis of Polyarylene Copolymer) 28.4 g (2.87) of the oligomer of the formula (I) obtained above.
mmol), 2,5-dichloro-4 ′-(4-phenoxy) phenoxybenzophenone (DCPPB) 29.2.
g (67.1 mmol), bis (triphenylphosphine) nickel dichloride 1.37 g (2.1 mmo)
l), sodium iodide 1.36 g (9.07 mmo)
l), triphenylphosphine 7.34 g (28.0 m)
mol) and 11.0 g (168 mmol) of zinc powder were placed in a flask and purged with dry nitrogen. 130 ml of N-methyl-2-pyrrolidone was added, and the mixture was heated to 80 ° C. and stirred for 4 hours to carry out polymerization. The polymerization solution was diluted with THF, coagulated and recovered with hydrochloric acid / methanol, repeated washing with methanol, dissolved with THF, and purified by reprecipitation in methanol,
The polymer collected by filtration is vacuum dried to obtain 50.7 g of the desired copolymer.
(96%) was obtained. The polystyrene reduced number average molecular weight determined by GPC (THF) was 40,000 and the weight average molecular weight was 145,000.

Example 1 25 g of the copolymer obtained above was placed in a 1000 ml separable flask equipped with a stirrer and a thermometer, and the concentration was adjusted to 9
750 ml of 6.4% sulfuric acid was added, and the mixture was stirred under a nitrogen stream for 24 hours while maintaining the internal temperature at 25 ° C. When the viscosity of the reaction solution was measured (25 ° C) at a reaction time of 6 hours, it was 40
It was 0 mPa · s, and sufficient stirring was possible. The obtained solution was poured into a large amount of ion-exchanged water to precipitate the polymer. The polymer was washed repeatedly until the pH of the wash water reached 5. After drying, 29 g (96%) of a sulfonic acid group-containing polymer was obtained. GPC of polymer containing sulfonic acid group (NMP)
The polystyrene-equivalent number average molecular weight calculated in
0, the weight average molecular weight was 277,000. The sulfonic acid equivalent of the present sulfonic acid group-containing polymer is 2.1 mg equivalent /
It was g. The weight retention of this sulfonic acid group-containing polymer after the hot water resistance test was 99%.

Example 2 50 g of the copolymer synthesized in Reference Example was placed in a 1000 ml separable flask equipped with a stirrer and a thermometer,
650 ml of 98.5% concentration sulfuric acid was added, and the mixture was stirred under a nitrogen stream for 24 hours while maintaining the internal temperature at 15 ° C. Reaction time 6
When the viscosity of the reaction solution was measured (15 ° C.) at the time, it was 5000 mPa · s, and sufficient stirring was possible. The obtained solution was poured into a large amount of ion-exchanged water to precipitate the polymer. The polymer was washed repeatedly until the pH of the wash water reached 5. After drying, 59 g (97%) of a sulfonic acid group-containing polymer was obtained. Of sulfonic acid group-containing polymer
The polystyrene-equivalent number average molecular weight determined by GPC (NMP) is 6
The molecular weight was 8,000 and the weight average molecular weight was 279,000. The sulfonic acid equivalent of the sulfonic acid group-containing polymer is 2.
It was 1 mg equivalent / g. The weight retention of this sulfonic acid group-containing polymer after the hot water resistance test was good at 99%.

Comparative Example 1 50 g of the copolymer synthesized in Reference Example was placed in a 1000 ml separable flask equipped with a stirrer and a thermometer.
650 ml of 98.5% concentration sulfuric acid was added, and the mixture was stirred under a nitrogen stream for 24 hours while maintaining the internal temperature at 30 ° C. Reaction time 6
When the viscosity of the reaction solution was measured (15 ° C.) at the time, it was 1000 mPa · s. The obtained solution was poured into a large amount of ion-exchanged water to precipitate the polymer. The polymer was washed repeatedly until the pH of the wash water reached 5. After drying, 59 g (97%) of a sulfonic acid group-containing polymer was obtained. The polystyrene-equivalent number average molecular weight of the sulfonic acid group-containing polymer determined by GPC (NMP) was 68,000, and the weight average molecular weight was 279,000. The sulfonic acid equivalent amount of the present sulfonic acid group-containing polymer was as high as 2.8 mg equivalent / g, the weight retention rate after the hot water resistance test was 55%, and cracking occurred in the film when the sample was taken out.

Comparative Example 2 50 g of the copolymer synthesized in Reference Example was placed in a 1000 ml separable flask equipped with a stirrer and a thermometer.
400 ml of 96.4% concentration sulfuric acid was added, and the mixture was stirred under a nitrogen stream for 24 hours while maintaining the internal temperature at 25 ° C. During the reaction time, the viscosity of the reaction solution was very high and stirring was difficult. At the reaction time of 6 hours, the viscosity of the reaction solution was measured (2
When the temperature was 5 ° C.), it was 500000 mPa · s or more.

[0040]

According to the present invention, it is an object of the present invention to provide a production method capable of controlling the solution viscosity during the sulfonation reaction within an appropriate range and easily controlling the amount of sulfonic acid groups introduced.

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Claims (3)

[Claims] 1. When sulfonating a polyarylene-based polymer, sulfuric acid having a concentration of 95.5 to 97.4% by weight is used in an amount of 10 ml or more per 1 g of the polymer to obtain a polyarylene-based polymer and sulfuric acid. The method for producing a sulfonic acid group-containing polymer is characterized in that the reaction liquid comprising 2. A polymer 1 containing sulfuric acid having a concentration of 97.5% by weight or more when the polyarylene polymer is sulfonated.
A method for producing a sulfonic acid group-containing polymer, characterized in that 3 ml or more per g is used and the reaction liquid comprising the polyarylene polymer and sulfuric acid is kept at 25 ° C. or lower. 3. The method for producing a sulfonic acid group-containing polymer according to claim 1, wherein the sulfonated polymer is a polyarylene polymer having a weight average molecular weight of 500,000 or less. .