JP2003212988A - Polyarylene based polymer and proton conductive film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polymer which has high toughness due to its possession of a flexing structure in the main chain, and is difficult to reduce the above toughness and hot water resistance due to the inhibition of excess sulfonation even when sulfonated, a sulfo group-containing copolymer to be obtained by sulfonating the polymer, and a proton conductive film which is composed of the sulfo group-containing copolymer, excels in toughness and is well balanced with respect to excellent various properties such as durability, resistance to oxidation, heat resistance, and proton conductivity. <P>SOLUTION: The polyarylene based polymer comprises (A) a structural unit to be represented by formula (a), (B) a structural unit to be represented by formula (b), and (C) a structural unit to be represented by formula (c). The sulfonated polymer is obtained by sulfonating the polyarylene based copolymer. The ion conductive film is composed of the sulfonated polymer. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel polyarylene-based polymer and a proton conductive membrane comprising a sulfonated product of the polymer. Proton conductive membranes are known to be useful for primary battery electrolytes, secondary battery electrolytes, polymer solid electrolytes for fuel cells, display devices, various sensors, signal transmission media, solid capacitors, ion exchange membranes, etc. There is.

[0002]

2. Description of the Prior Art Electrolytes are often used in (water) solutions. 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 electric / electronic materials, and the second reason is the shift to light, thin, short, small and power saving. Conventionally, as a proton conductive material, both an inorganic material and an organic material are known. An example of the inorganic substance is, 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 an electrode.

On the other hand, examples of organic compounds include polymers belonging to so-called cation exchange resins, for example, sulfonated products of vinyl polymers such as polystyrene sulfonic acid,
Introducing sulfonic acid groups and phosphoric acid groups into perfluoroalkyl sulfonic acid polymers such as Nafion (manufactured by DuPont), perfluoroalkyl carboxylic acid polymers, and heat resistant polymers such as polybenzimidazole and polyether ether ketone. Polymer Preprints,
Japan, Vol.42, No.7, p.2490 ~ 2492 (1993), Polymer Prep
rints, Japan, Vol.43, No.3, p735〜736 (1994), Polymer P
reprints, Japan, Vol. 42, No. 3, p730 (1993)] and the like. These organic polymers are usually used in the form of a film, but by utilizing the fact that they are soluble in a solvent or thermoplastic, a conductive film can be joined and processed on the electrodes. However, in many of these organic polymers, the proton conductivity is not yet sufficient, and the durability and the proton conductivity decrease at high temperature (100 ° C or higher). Decrease, that the dependence on humidity conditions is large, or that the adhesion to the electrode is not sufficiently satisfactory, or that the strength decreases due to excessive swelling during operation due to the water-containing polymer structure, There is a problem that it leads to shape collapse. Therefore, these organic polymers have various problems when applied to the above electric / electronic materials.

US Pat. No. 5,403,675 proposes a solid polymer electrolyte composed of sulfonated rigid polyphenylene. The main component of this polymer is a polymer obtained by polymerizing an aromatic compound having a phenylene chain (structure described in column 9 of the specification), and this is reacted with a sulfonating agent to introduce a sulfonic acid group. . However, although the proton conductivity is improved by increasing the introduction amount of the sulfonic acid group, mechanical properties of the sulfonated polymer obtained at the same time, for example, toughness such as elongation at break and bending resistance and hot water resistance are significantly impaired.

[0005]

Therefore, an object of the present invention is toughness because it has a flexible structure in the main chain, and excessive sulfonation is suppressed even if it is sulfonated. A polymer in which hot water resistance does not easily decrease, a sulfonic acid group-containing polymer obtained by sulfonation of the polymer,
And a proton conductive membrane made of the sulfonic acid group-containing polymer, which is excellent in toughness and has excellent balance of various physical properties such as durability, oxidation resistance, heat resistance and proton conductivity. Is.

[0006]

DISCLOSURE OF THE INVENTION The first aspect of the present invention is a novel polyarylene copolymer, that is, the following general formula (a):

[0007]

[Chemical 5] [In the formula, A is an electron-withdrawing group, and R ^{1 to} R ⁸ are the same or different and each is a hydrogen atom, a fluorine atom, an alkyl group or a fluoroalkyl group. ], The structural unit (A) represented by the following general formula (b):

[0008]

[Chemical 6] [In the formula, A is as described above, B is an electron-donating atom or a divalent group, and R ^{9 to} R ¹⁵ are the same or different and each is a hydrogen atom, a fluorine atom, an alkyl group or a fluoroalkyl group. Where Z is an aryl group and m is 1 or 2. ] The structural unit (B) represented by this, and the following general formula (c):

[0009]

[Chemical 7] [Wherein A, B and R ^{1 to} R ⁸ are as described above,
n is an integer of 2 or more. ] Structural unit (C) represented by
There is provided a polyarylene-based copolymer having: The present invention secondly provides a sulfonated polymer of the above polyarylene-based copolymer. Further, the present invention is, thirdly,
Provided is a proton conductive membrane made of the above sulfonated polymer.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The sulfonation of a copolymer obtained by copolymerizing a monomer constituting a structural unit (A) and a monomer constituting a structural unit (B), which will be described in detail below. Even if it is a polymer, a proton conductive membrane can be obtained, and the amount of sulfonic acid groups introduced into the sulfonated polymer can be controlled, but the obtained membrane is brittle and has a problem in handling. . In the present invention, the structural unit (C) is combined with the structural unit (A) and the structural unit (B) to suppress excessive sulfonation, and the structural unit (C) has a relatively long molecular structure having flexibility. Therefore, it is possible to obtain a sulfonated polymer which is excellent in toughness, hot water resistance, heat resistance, and oxidation resistance.

[Monomer Constituting Structural Unit (A)] The unit represented by the general formula (a) is represented by the following general formula (a-
It is derived from the monomer represented by m) (hereinafter referred to as “monomer (A)”). [Monomer (A)]

[0012]

[Chemical 8] [Wherein, X is independently a chlorine atom, a bromine atom, an iodine atom or —OSO ₂ Y (wherein Y represents an alkyl group, a halogenated alkyl group or an aryl group), A and R ^{1 to} R ⁸ Is as described above. ] In the formula (a-m), as the electron withdrawing group (A), -CO -, - CONH -, - (CF 2) p- ( wherein,
p is an integer of 1 to _{10), - C (CF 3)} 2 -, - C
OO -, - SO -, - SO 2 - , and the like. Similarly, examples of the alkyl group include a methyl group and an ethyl group, and examples of the fluoroalkyl group include a trifluoromethyl group and a pentafluoroethyl group. Onajiku, Y in -OSO ₂ Y, a methyl group as the alkyl group, such as an ethyl group, a trifluoromethyl group as a halogenated alkyl group, such as pentafluoroethyl group, a phenyl group as the aryl group, p- tolyl group And so on.

Examples of the monomer (A) include the followings. (A-1) 4,4'-dichlorobenzophenone, 2,4'-dichlorobenzophenone, 3,3'-dichlorobenzophenone, 4,4'-dibromobenzophenone, 2,4'-dibromobenzophenone, 3,3'- Dibromobenzophenone, 4,4'-diiodobenzophenone, 2,4'-diiodobenzophenone, 3,3'-diiodobenzophenone, bis (4-trifluoromethylsulfonyloxyphenyl) ketone, bis (3-trifluoro Methylsulfonyloxyphenyl) ketone (A-2) 4,4'-dichlorobenzanilide, 3,3'-dichlorobenzanilide, 3,4'-dichlorobenzanilide, 4,4'-dibromobenzanilide, 3,4'-dichlorobenzanilide 3'-dibromobenzanilide, 3,4'-dibromobenzanilide, 4,4'-diiodobenzanilide, 3,3'-diiodobenzanilide, 3,4'-diiodobenzanilide

(A-3) Bis (chlorophenyl) difluoromethane, bis (chlorophenyl) tetrafluoroethane, bis (chlorophenyl) hexafluoropropane, bis (chlorophenyl) octafluorobutane, bis (chlorophenyl) decafluoropentane, bis (chlorophenyl) ) Dodecafluorohexane, bis (chlorophenyl) tetradecafluoroheptane, bis (chlorophenyl) hexadecafluorooctane, bis (chlorophenyl) octadecafluorononane, bis (chlorophenyl) eicosafluorodecane, bis (bromophenyl) difluoromethane, bis
(Bromophenyl) tetrafluoroethane, bis (bromophenyl) hexafluoropropane, bis (bromophenyl) octafluorobutane, bis (bromophenyl) decafluoropentane, bis (bromophenyl) dodecafluorohexane, bis (bromophenyl) tetra Decafluoroheptane, bis (bromophenyl) hexadecafluorooctane, bis (bromophenyl) octadecafluorononane, bis (bromophenyl) eicosafluorodecane, bis (iodophenyl) difluoromethane, bis (iodophenyl) tetrafluoroethane , Bis (iodophenyl)
Hexafluoropropane, bis (iodophenyl) octafluorobutane, bis (iodophenyl) decafluoropentane, bis (iodophenyl) dodecafluorohexane, bis (iodophenyl) tetradecafluoroheptane, bis (iodophenyl) hexadecafluorooctane , Bis (iodophenyl) octadecafluorononane,
Bis (iodophenyl) eicosafluorodecane

(A-4) 2,2-bis (4-chlorophenyl) hexafluoropropane, 2,2-bis (3-chlorophenyl) hexafluoropropane, 2,2-bis (4-bromophenyl) hexafluoropropane 2,2-bis (3-bromophenyl) hexafluoropropane, 2,2-bis (4-iodophenyl) hexafluoropropane, 2,2-bis (3-iodophenyl) hexafluoropropane, bis (4- Trifluoromethylsulfonyloxyphenyl) hexafluoropropane, bis (3-
(Trifluoromethylsulfonyloxyphenyl) hexafluoropropane (A-5) 4-chlorophenyl 4-chlorobenzoate, 3-chlorophenyl 4-chlorobenzoate, 3-chlorophenyl 3-chlorobenzoate, 3-chlorobenzoic acid Acid-4-chlorophenyl, 4-
Bromobenzoic acid-4-bromophenyl, 4-bromobenzoic acid-
3-Bromophenyl, 3-Bromophenyl 3-bromobenzoate, 4-Bromophenyl 3-bromobenzoate (A-6) Bis (4-chlorophenyl) sulfoxide, Bis (3-
Chlorophenyl) sulfoxide, bis (4-bromophenyl) sulfoxide, bis (3-bromophenyl) sulfoxide, bis (4-iodophenyl) sulfoxide, bis (3-iodophenyl) sulfoxide, bis (4-trifluoromethylsulfonyloxy) (Phenyl) sulfoxide, bis (3-trifluoromethylsulfonyloxyphenyl) sulfoxide (A-7) bis (4-chlorophenyl) sulfone, bis (3-chlorophenyl) sulfone, bis (4-bromophenyl) sulfone, bis (3 -Bromophenyl) sulfone, bis (4-iodophenyl) sulfone, bis (3-iodophenyl) sulfone, bis (4-trifluoromethylsulfonyloxyphenyl) sulfone, bis (3-trifluoromethylsulfonyloxyphenyl) Sulfone

[Monomer Constituting Structural Unit (B)] The unit represented by the general formula (b) is represented by the following general formula (b-
It is derived from the monomer represented by m) (hereinafter referred to as “monomer (B)”). [Monomer (B)]

[0017]

[Chemical 9] (In the formula, X, A, B, R ^{9 to} R ¹⁵ , Z and m are as described above.) The electron-donating atom or the divalent group (B) in the general formula (b-m). As, -O-, -S-, -CH = CH
-, -C≡C-,

[0018]

[Chemical 10]

[0019]

[Chemical 11] And so on.

Examples of the aryl group related to Z are, for example, phenyl group, naphthyl group and formula:

[0021]

[Chemical 12] (In the formula, R ^{25 to} R ³³ are the same or different and are a hydrogen atom,
It is a fluorine atom, an alkyl group or a fluoroalkyl group. ) And a biphenylyl group represented by. Examples of the monomer (B) include compounds represented by the following formulas.

[0022]

[Chemical 13] [Wherein, X and Z are as described above. ] More specifically, examples of the monomer (B) include 2,4-
Examples thereof include dichloro-4′-phenoxybenzophenone, 4′-phenoxyphenyl 2,5-dichlorobenzoate, 4′-phenoxyphenyl 2,4-dichlorobenzoate, and those represented by the following formula.

[0023]

[Chemical 14]

[0024]

[Chemical 15]

[0025]

[Chemical 16]

[0026]

[Chemical 17] The monomer (B) is 2,5-dichloro-4 ′-[(4-phenoxy) phenoxy] benzophenone, for example, 2,5-dichloro-4 ′-[(4-phenoxy) phenoxy] benzophenone.
Dichloro-4'-fluorobenzophenone and p-phenoxyphenol were used as starting reaction materials, and potassium carbonate was added to the starting reaction materials to convert them into highly reactive phenoxides. Also, dimethylacetamide, toluene, N-methylpyrrolidone, dimethyl were used as reaction solvents. Use an aprotic dipolar polar solvent such as sulfoxide at a reaction temperature of 80-200 ° C for 1
It can be synthesized by reacting for about 30 hours.

[Monomer Constituting Structural Unit (C)] The unit represented by the above general formula (c) is represented by the following general formula (c-
It is derived from the monomer represented by m) (hereinafter referred to as “monomer (C)”, and may also be referred to as “oligomer (C)” or “polymer (C)”).

[0028]

[Chemical 18] [Wherein, X, A, B, R ^{1 to} R ⁸ are as described above,
n is 2 or more, preferably 2 to 100, particularly preferably 2 to 8
It is an integer of 0. ] Examples of the monomer (C) of the present invention include 2,2-bis [4
-{4- (4-chlorobenzoyl) phenoxy} phenyl] -1,1,
Examples include 1,3,3,3-hexafluoropropane, bis [4- {4- (4-chlorobenzoyl) phenoxy} phenyl] sulfone, and compounds represented by the following chemical formula.

[0029]

[Chemical 19] (In the above formula, X is as described above.)

The monomer (C) (or oligomer (C) or polymer (C)) can be synthesized, for example, by the following reaction. First, in order to convert the bisphenol linked with an electron-withdrawing group into the corresponding bisphenol alkali metal salt, such as N-methyl-2-pyrrolidone, N, N-dimethylacetamide, sulfolane, diphenyl sulfone, and dimethyl sulfoxide. 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 or an alkali metal carbonate is added.

Usually, the alkali metal is reacted with the hydroxyl group of phenol with a slight excess, and usually 1.1 to 2 equivalents are used. Preference is given to using 1.2 to 1.5 times equivalent amount. At this time, a solvent that is azeotropic with water such as benzene, toluene, xylene, hexane, cyclohexane, octane, chlorobenzene, dioxane, tetrahydrofuran, anisole, and phenetole is allowed to coexist, and the chlorine atom activated by the electron-withdrawing group is substituted. Aromatic dichloride compound, for example, 4,4'-dichlorobenzophenone, bis (4-chlorophenyl) sulfone, bis (3-nitro-4-chlorophenyl) sulfone, 2,6-dichlorobenzonitrile,
Excess molar reaction of 1,3-bis (4-chlorobenzoyl) benzene with bisphenol. The molecular weight of the obtained oligomer or polymer can be controlled by the molar ratio.

Due to the reactivity, if the difluoro compound is used,
The polycondensation reaction can proceed under milder conditions. In this case, the polycondensation of the phenol-terminated oligomer in the first stage is carried out in an excess system of bisphenol, and then the fluorochloro compound is reacted to obtain the desired terminal dichloride oligomer or polymer activated with an electron-withdrawing group.
Examples of the difluoro compound used include 4,4′-difluorobenzene, bis (4-fluorophenyl) sulfone, and 2,6-
Difluorobenzonitrile, hexafluorobenzene,
Examples thereof include decafluorobiphenyl and 2,5-difluorobenzophenone. Further, examples of fluorochloro compounds include 4,4′-chlorofluorobenzophenone and 4-fluorophenyl-4′-chlorophenyl sulfone. 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 80 ° C to 250 ° C. The reaction time is in the range of 15 minutes to 100 hours, preferably 1 hour to 50 hours. If one of the most preferable polycondensation methods is shown, the outline thereof can be represented by the following formula (I).

[0033]

[Chemical 20] ... (I) [In formula, A is as above-mentioned. n'and m'represent the number of moles, and m '>n'. a is an integer of 2 or more. ] The oligomer or polymer thus obtained is
Its structure can be confirmed by IR, NMR, elemental analysis and the like. Specific examples of the structure of the oligomer (C) or the polymer (C) having an aromatic chloride at the molecular end include the following.

[0034]

[Chemical 21]

[Chemical formula 22]

[0035]

[Chemical formula 23] (In the above formula, n is an integer of 3 or more.)

[Quantity Ratio Relationship] The content ratio of the structural unit (A) / structural unit (B) / structural unit (C) is 2.5 to 77.5 / 95.
To 20 / 2.5 to 77.5 (mol%), preferably 3 to 7
5/94 to 30/3 to 75 (mol%), more preferably 5 to 7
It is 0/90 to 35/5 to 70 (mol%). The content ratio of this structural unit (A) / structural unit (B) / structural unit (C) is such that the corresponding monomer (A), monomer (B) and monomer (C) (or oligomer (C) or polymer (C) )) Can be appropriately adjusted by setting the charged molar ratio.

[Synthesis of Polyarylene Copolymer] The above polyarylene copolymer comprises a monomer (A), a monomer (B) and a monomer (C) (or an oligomer (C) or a polymer (C)). It can be obtained by coupling polymerization. The polymerization method will be described below. The catalyst used in the polymerization reaction is a catalyst system containing a transition metal compound, and the catalyst system includes (1) a transition metal salt and a compound to be a ligand (hereinafter referred to as a ligand component), or a ligand. A transition metal complex (including a copper salt) in which a ligand is coordinated, and (2) a reducing agent are essential components, 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, iron bromide Iron compounds such as iron iodide, cobalt compounds such as cobalt chloride, cobalt bromide, and cobalt iodide. Of these, nickel chloride and nickel bromide are particularly preferable. Further, as the ligand component, triphenylphosphine, 2,2'-bipyridine,
Examples thereof include 1,5-cyclooctadiene and 1,3-bis (diphenylphosphino) propane, but 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 in advance 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 and the like, nickel chloride bis (triphenylphosphine), nickel chloride (2 , 2'-Bipyridine) is preferred.

Examples of the reducing agent that can be used in the catalyst system include iron, zinc, manganese, aluminum, magnesium, sodium and calcium, with zinc, magnesium and manganese being preferred. These reducing agents can be further activated and used by bringing them into contact with an acid such as an organic acid. Further, as the "salt" which can be used in the catalyst system, sodium compounds such as sodium fluoride, sodium chloride, sodium bromide, sodium iodide and sodium sulfate, potassium fluoride, potassium chloride, potassium bromide, iodide Potassium compounds such as potassium iodide and potassium sulfate, tetraethylammonium fluoride, tetraethylammonium chloride, tetraethylammonium bromide, tetraethylammonium iodide, ammonium compounds such as tetraethylammonium sulfate, and the like,
Sodium bromide, sodium iodide, potassium bromide, tetraethylammonium bromide and tetraethylammonium iodide are preferred.

The proportion of each component used in the catalyst system is usually 0.0001 to 10 mol, based on 1 mol of the total amount of the above-mentioned monomers or oligomers of the transition metal salt or transition metal complex,
It is preferably 0.01 to 0.5 mol. If it is less than 0.0001 mol, the polymerization reaction will not proceed sufficiently, while if it is more than 10 mol, the molecular weight will 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. 0.1
If it is less than 100 mol, the catalytic activity will be insufficient, while if it exceeds 100 mol, the molecular weight will be lowered.

The ratio of the reducing agent used in the catalyst system is usually 0.1 to 100 mol, preferably 1 to 10 mol, based on 1 mol of the total amount of the monomers and oligomers. If less than 0.1 mol, the polymerization does not proceed sufficiently, while 100
If it exceeds the molar amount, there is a problem in that purification of the obtained polymer becomes difficult. Further, when a "salt" is used in the catalyst system, the usage ratio thereof is usually 0.001 to 100 mol, preferably 0.01 to 1 mol, based on 1 mol of the total of the above-mentioned monomers or oligomers. If it is less than 0.001 mol, the effect of increasing the polymerization rate is insufficient, while if it exceeds 100 mol, there is a problem that purification of the resulting polymer becomes difficult.

The polymerization solvent which can be used in the present invention is, for example, tetrahydrofuran, cyclohexanone, dimethylsulfoxide, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone or γ-butyrolactone. , Γ-butyrolactam and the like, and tetrahydrofuran, N, N-dimethylformamide, N, N-dimethylacetamide and N-methyl-2-pyrrolidone are preferable. It is preferable to use these polymerization solvents after drying them sufficiently. The concentration of the above-mentioned monomer or oligomer in the polymerization solvent is usually 1 to 90% by weight, preferably 5 to 40% by weight. The polymerization temperature at the time of obtaining the polyarylene copolymer by 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 structure of the copolymer of the present invention is, for example,
The infrared absorption spectrum, C-O-C absorption of 1,230～1,250Cm ^-1, confirmed by like C = O absorption of 1,640～1,660Cm ^-1, also nuclear magnetic resonance spectra ⁽¹ H-
By NMR), the structure can be confirmed from the peak of the aromatic proton at 6.8 to 8.0 ppm.

[Synthesis of Sulfonated Polymer] Next, the copolymer having a sulfonic acid group used in the conductive membrane of the present invention is prepared by using a sulfonating agent in the above-mentioned copolymer having no sulfonic acid group. It can be obtained by introducing a sulfonic acid group by a conventional method. As a method of introducing a sulfonic acid group, for example, a copolymer having no sulfonic acid group, using a known sulfonating agent such as sulfuric anhydride, fuming sulfuric acid, chlorosulfonic acid, sulfuric acid, sodium bisulfite, It can be sulfonated under known conditions [Polyme
r 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.3, p.2490〜2492 (199
3)]. That is, the reaction conditions for this sulfonation are:
The copolymer having no sulfonic acid group is reacted with the sulfonating agent in the absence of a solvent or in the presence of a solvent.
Examples of the solvent include hydrocarbon solvents such as n-hexane, ether solvents such as tetrahydrofuran and dioxane, dimethylacetamide, 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 reaction temperature is not particularly limited, but is usually -50 to
The temperature is 200 ° C, preferably -10 to 100 ° C. The reaction time is usually 0.5 to 1,000 hours, preferably 1 to 200 hours.

The amount of sulfonic acid groups in the sulfonic acid group-containing copolymer of the present invention thus obtained is 0.5 to 3
Milligram equivalent / g, preferably 0.8 to 2.8 milligram equivalent / g
Is. If it is less than 0.5 milliequivalent / g, the proton conductivity will not increase, while if it exceeds 3 milliequivalent / g, the hydrophilicity will increase and the water resistance will be insufficient, or the durability will decrease. The amount of the sulfonic acid group is changed by changing the ratio of the total amount of the monomer (B) to the monomer (A) and the monomer (C) (or the oligomer (C) or the polymer (C)). It can be easily adjusted by changing the type and combination of (C) (or oligomer (C) or polymer (C)).

The molecular weight of the thus obtained precursor polymer of the sulfonic acid group-containing copolymer of the present invention before sulfonation is the polystyrene-reduced weight average molecular weight,
It is 10,000 to 1,000,000, preferably 20,000 to 800,000. If it is less than 10,000, the film performance is insufficient, such as cracking 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.
The structure of the sulfonic acid group-containing copolymer of the present invention has an infrared absorption spectrum of 1,030 to 1,045 cm ^-1 , 1,16.
S = O absorption at 0~1,190cm ^-1, C of 1,130～1,250Cm ^-1
It can be confirmed by —O—C absorption, C═O absorption at 1,640 to 1,660 cm ⁻¹ , and the composition ratio of these can be known by neutralization titration of sulfonic acid or elemental analysis. In addition, by nuclear magnetic resonance spectrum ( ¹ H-NMR), 6.8 to 8.0 pp
Its structure can be confirmed from the peak of the aromatic proton of m.

[Proton Conducting Membrane] Next, the conducting membrane of the present invention comprises the above sulfonic acid group-containing copolymer. In addition to the above sulfonic acid group containing copolymer, inorganic acids such as sulfuric acid and phosphoric acid, An organic acid containing a carboxylic acid, an appropriate amount of water, etc. may be used in combination. To produce the conductive membrane of the present invention, for example, after dissolving the sulfonic acid group-containing copolymer of the present invention in a solvent,
A casting method for forming a film by casting, a melt molding method, and the like are included. Here, examples of the solvent in the casting method include aprotic polar solvents such as dimethylacetamide, dimethylformamide, N-methyl-2-pyrrolidone, and dimethylsulfoxide. An alcohol solvent such as methanol may be further mixed with these solvents. The conductive film of the present invention is, for example, a proton conductive material that can be used in electrolytes for primary batteries, electrolytes for secondary batteries, polymer solid electrolytes for fuel cells, display elements, various sensors, signal transmission media, solid capacitors, ion exchange membranes, etc. It can be used as a conductive film.

[0047]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the following examples. The evaluation of various measurement items in the examples is as follows. [Number average molecular weight, weight average molecular weight] The weight average molecular weight and the number average molecular weight of the precursor polymer before sulfonation are determined by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent. I asked. [Amount of sulfonic acid group] Washing water of the obtained sulfonated polymer is washed until the pH becomes 4 to 6 to remove free remaining acid, thoroughly washed with water, dried, and weighed a predetermined amount. Then, it was dissolved in a mixed solvent of THF / water, titrated with a standard solution of NaOH using phenolphthalein as an indicator, and the amount of sulfonic acid groups (millgram equivalent / g) was determined from the neutralization point.

[Proton conductivity] AC resistance was measured by pressing a platinum wire (diameter: 0.5 mm) against the surface of a strip-shaped film sample having a width of 5 mm, holding the sample in a thermo-hygrostat, and measuring the AC impedance between the platinum wires. Obtained from measurement. The impedance at an alternating current of 10 kHz was measured under the environment of 85 ° C. and relative humidity of 90%. A chemical impedance measuring system manufactured by NF Circuit Design Block Co., Ltd. was used as a resistance measuring device, and JW241 manufactured by Yamato Chemical Co., Ltd. was used as a thermo-hygrostat. Five platinum wires were pressed at intervals of 5 mm, the distance between the electrodes was changed to 5 to 20 mm, and the AC resistance was measured. The specific resistance of the membrane is calculated from the distance between the electrodes and the gradient of the resistance according to the following formula, and the AC impedance (proton conductivity [S / cm] =
1 / [Ω · cm]) was calculated. Specific resistance R [Ω · cm] = 0.5 [cm] × film thickness [cm] × gradient between resistance electrodes [Ω / cm]

[Tensile Strength Characteristic] A sulfonated polymer film having a thickness of 50 μm was formed into a test piece having a width of 3 mm and a length of 65 mm (distance between chucks: 25 mm), and the tensile modulus was used to measure the elastic modulus at room temperature and the breaking strength. The yield strength and elongation were measured. [Fenton reagent resistance] Soaking the film sample in an aqueous solution of 3% hydrogen peroxide, 20 ppm ferrous sulfate at 40 ° C,
The change with time after 24 hours was judged from the appearance and weight change. The appearance and those showing a weight residual rate of 95% or more were marked with ◯, and the cases where any one of the external appearance and the weight residual ratio was insufficient were marked with x. [Temperature dependence of dynamic viscoelasticity] Using a dynamic viscoelasticity measuring device in tension mode (frequency 11 Hz) for film samples, ta
The nδ peak temperature was measured and used as the main dispersion temperature based on the glass transition. [Heat-resistant water] A film was immersed in hot water at 95 ° C, and the weight retention after immersion was 90% or more, and ◯ was evaluated.

-Synthesis Example- [Synthesis of Polymer (C)] Stirrer, Thermometer, Cooling Tube, De
In an 1-L three-necked flask equipped with an an-Stark tube and a three-way cock for introducing nitrogen, 2,2-bis (4-hydroxyphenyl) -1,1,1,3,3,3-hexafluoropropane ( Bisphenol AF) 67.3g (0.20mol), 4,4'-dichlorobenzophenone (4,4'-DCBP) 53.6g (0.21mol), potassium carbonate 71.9g (0.52mol), sulfolane 300mL, toluene 150mL, oil The mixture was heated in a bath 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. After that, most of the toluene was removed while gradually raising the reaction temperature to 190 ° C., the reaction was continued at 190 ° C. for 10 hours, then 3.35 g (0.013 mol) of 4,4′-DCBP was added, and the reaction was continued for another 5 hours. did. The obtained reaction solution was allowed to cool, then diluted with 300 mL of toluene, the by-product precipitate of the inorganic compound was removed by filtration, and the filtrate was put 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%).

The polystyrene-equivalent number average molecular weight of the obtained polymer determined by GPC (THF solvent) was 12,700, and the weight average molecular weight was 28,200. The infrared absorption spectrum is shown in FIG. The obtained polymer is THF, NM
Soluble in P, DMAc, sulfolane, etc., Tg is 151
℃, the thermal decomposition temperature was 524 ℃. The polymer obtained has the formula:

[0052]

[Chemical formula 24] The average value of n was determined to be 24 from the structure and the number average molecular weight described above.

-Example 1- (Monomer (A): 4,4'-dichlorobenzophenone 15)
Mol% copolymer) stirring blade, thermometer, in a 500 mL three-necked flask equipped with a cooling tube, 2,5-dichloro-4 '-(4-phenoxy) phenoxybenzophenone 35.9 g (82.4 mmol),
The above polymer (C) (number average molecular weight 12,700) 33.0 g (2.
60mmol), 4,4'-dichlorobenzophenone 3.77g (15.0
mmol), bis (triphenylphosphine) nickel dichloride 1.96 g (3.00 mmol), sodium iodide 1.95 g
(130 mmol), 10.5 g of triphenylphosphine (40.0 mm
ol) and 15.7 g (240 mmol) of zinc were taken and dried under vacuum.
After replacing with dry nitrogen, N-methylpyrrolidone (NMP) 162m
L was added and the mixture was stirred in an oil bath at 80 ° C. for polymerization.

After 3 hours, the polymerization solution was poured into 5 L of methanol containing 10 vol% concentrated hydrochloric acid to precipitate the polymer.
The polymer was taken out, dried, dissolved in 800 mL of tetrahydrofuran (THF), and filtered using Celite as a filter medium. The obtained solution was reprecipitated in 5 L of methanol to obtain 61 g of the target polymer (yield 93%). The number average molecular weight of this polymer was 54,800 and the weight average molecular weight was 133,000. Add 60 g of this polymer to 600 mL of concentrated sulfuric acid and add it at room temperature for 24 hours.
Stir for hours. The reaction solution was poured into 5 L of distilled water to precipitate the sulfonated product. The precipitate was crushed with a mixer and further washed with 5 L of distilled water until the washing liquid became neutral. The product was dried with hot air to obtain 69 g of a sulfonated polymer. The infrared absorption spectrum is shown in FIG. The sulfonic acid group equivalent of this product was 1.8 milligram equivalent / g.

Further, the obtained sulfonated polymer was treated with NMP.
/ Methanol (50/50 (volume ratio)) was dissolved in a mixed solvent to prepare a 15 wt% polymer solution. The film was formed with a doctor blade and dried at 100 ° C for 30 minutes and 150 ° C for 1 hour. The obtained film was immersed in water for 4 hours to extract the solvent contained in the film. After the extraction, the water on the surface was wiped off and air-dried for 24 hours in a constant temperature and high humidity room at 25 ° C. and 50% RH to prepare an evaluation film. Proton conductivity, mechanical properties:
Tensile strength characteristics (elastic modulus, yield strength, tensile strength), hot water resistance, Fenton reagent resistance), thermal properties: temperature dependence of dynamic viscoelasticity, thermal decomposition temperature were measured. The results are shown in Table 1.

Example 2- (Monomer (A): 4,4'-dichlorobenzophenone 20)
Mol% copolymer) The amount charged in Example 1 was 2,5-dichloro-4 '-(4-phenoxy) phenoxybenzophenone 3
3.8 g (77.6 mmol), the above polymer (C) (number average molecular weight 12,700) 30.5 g (2.40 mmol), 4,4'-dichlorobenzophenone 5.02 g (20.0 mmol), N-methylpyrrolidone (NMP) 154 mL was changed. Polymerization was performed in the same manner except that 58 g (yield 93%) of the target polymer was obtained. This polymer has a number average molecular weight of 41,000 and a weight average molecular weight of 109,00.
It was 0. 55 g of this polymer was added to 550 mL of concentrated sulfuric acid, and the mixture was stirred at room temperature for 24 hours. Pour the reaction solution into 5 L of distilled water,
The sulfonated product was precipitated. The precipitate was crushed with a mixer and further washed with 5 L of distilled water until the washing liquid became neutral. The product was dried with hot air to obtain 64 g of a sulfonated polymer. The sulfonic acid group equivalent of this product is 1.
It was 8 milligram equivalents / g.

Further, the obtained sulfonated polymer was treated with NMP /
It was dissolved in a mixed solvent of methanol (50/50 (volume ratio)) to prepare a 15 wt% polymer solution. The film was formed with a doctor blade and dried at 100 ° C for 30 minutes and 150 ° C for 1 hour. The obtained film was immersed in water for 4 hours to extract the solvent contained in the film. After the extraction, the water on the surface was wiped off and air-dried for 24 hours in a constant temperature and high humidity room at 25 ° C. and 50% RH to prepare an evaluation film. Proton conductivity, mechanical properties:
Tensile strength characteristics (elastic modulus, yield strength, tensile strength, elongation),
Resistance to hot water, resistance to Fenton's reagent, thermal properties: temperature dependence of dynamic viscoelasticity, thermal decomposition temperature were measured. The results are shown in Table 1.

[0058]

[Table 1]

[0059]

EFFECT OF THE INVENTION According to the present invention, a polymer having a flexible structure in the main chain has high toughness, and even if it is sulfonated, excessive sulfonation is suppressed, so that the above-mentioned toughness and hot water resistance are not easily lowered. , A sulfonic acid group-containing copolymer obtained by sulfonation of the polymer, and various toughness consisting of the sulfonic acid group-containing polymer, which are excellent in durability, oxidation resistance, heat resistance, proton conductivity, etc. It is possible to obtain a proton conductive membrane having well-balanced physical properties. Therefore, the proton conducting membrane of the present invention is used as a conducting membrane for 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 is available and its industrial significance is extremely great.

[Brief description of drawings]

FIG. 1 is an infrared absorption spectrum (IR) chart of a polymer (C) obtained in a synthesis example.

FIG. 2 is an infrared absorption spectrum (IR) chart of a sulfonated product of a polyarylene copolymer having 15 mol% of 4,4′-dichlorobenzophenone obtained in Example 1.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H01M 8/10 H01M 8/10 5H029 // H01M 6/18 6/18 E 10/40 10/40 B C08L 71:10 C08L 71:10 (72) Inventor Masayuki Takahashi 2-11-24 Tsukiji, Chuo-ku, Tokyo J.S.R. Co., Ltd. (72) Inventor Kohei Goto 2-11-24 Tsukiji, Chuo-ku, Tokyo J.S.R. In-house F-term (reference) 4F071 AA47 AA78 AF38 AH12 AH15 BA02 BB02 BC01 4J005 AA00 BA00 BB02 BD06 5G301 CA30 CD01 5H024 BB11 FF21 5H026 AA02 BB10 CX05 EE18 5H029 AJ05 AJ06 AJ11 AM16 CJ11

Claims (4)

[Claims] 1. The following general formula (a): [In the formula, A is an electron-withdrawing group, and R ^{1 to} R ⁸ are the same or different and each is a hydrogen atom, a fluorine atom, an alkyl group or a fluoroalkyl group. ], A structural unit (A) represented by the following general formula (b): [In the formula, A is as described above, B is an electron-donating atom or a divalent group, and R ^{9 to} R ¹⁵ are the same or different and each is a hydrogen atom, a fluorine atom, an alkyl group or a fluoroalkyl group. Where Z is an aryl group and m is 1 or 2. ] The structural unit (B) represented by the following general formula (c): [Wherein A, B and R ^{1 to} R ⁸ are as described above,
n is an integer of 2 or more. ] Structural unit (C) represented by
A polyarylene-based copolymer having: 2. The polyarylene copolymer according to claim 1, wherein the unit represented by the general formula (c) is represented by the following structural formula. [Chemical 4] [In the formula, a is an integer of 2 or more. ] 3. A sulfonated polymer obtained by sulfonation of the polyarylene copolymer according to claim 1. 4. A proton conductive membrane comprising the sulfonated polymer according to claim 3.