JP2005082757A - Polyarylene copolymer having sulfonic acid group, method for producing the same, polymeric solid electrolyte, proton conductive film and electrode for battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyarylene copolymer capable of performing the reaction with a catalyst efficiently in using it as an electrode since sulfonic acid group is set to be introduced into side chains, its number of chains is regulated and it is introduced at random into the polymer, a method for producing the same, a solid polymeric electrolyte, a proton conductive film and an electrode for a battery containing the polyarylene. <P>SOLUTION: This polyarylene having the sulfonic acid group consists of at least 1 kind selected from a constituting unit expressed by the following general formula (1), a constituting unit expressed by the following general formula (2) and a constituting unit expressed by the following general formula (3), and having 1.0-4.0 mean number of chains of constituting units expressed by the general formula (1) each other. [In each of the formulae, (m) is 0-10 integer; X is a divalent organic group or a direct bond; and Ar is an aromatic group]. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a polyarylene copolymer having a sulfonic acid group, a method for producing the copolymer, a polymer solid electrolyte obtained from the copolymer, a proton conductive membrane, and a battery electrode.

  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 electric / electronic materials, and the second reason is the shift to light, thin, small and power saving.

  Conventionally, both proton-conducting materials made of inorganic substances and organic substances are known. Examples of inorganic substances include 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 (trade name, manufactured by DuPont). , Perfluoroalkyl carboxylic acid polymers and polymers with sulfonic acid groups and phosphoric acid groups 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)).

  These organic polymers are usually used in the form of a film, but a conductive film can be bonded on the electrode by utilizing the solubility in a solvent or thermoplasticity. However, in many of these organic polymers, proton conductivity is not sufficient yet, proton conductivity is lowered at durability and high temperature (100 ° C. or higher), and mechanical properties, particularly elastic modulus is low. Decrease in strength due to excessive swelling during operation due to large decrease, high dependency under humidity conditions, or insufficient adhesion to electrodes, or water-containing polymer structure There is a problem that the shape collapses. Therefore, these organic polymers have various problems when applied to electrical / electronic materials.

  Furthermore, US Pat. No. 5,403,675 (Patent Document 1) proposes a solid polymer electrolyte made of sulfonated rigid polyphenylene. This polymer is mainly composed of a polymer obtained by polymerizing an aromatic compound comprising a phenylene chain (structure described in column 9 of the same specification), and this is reacted with a sulfonating agent to introduce sulfonic acid groups. However, although the proton conductivity is improved by increasing the amount of sulfonic acid groups introduced, the mechanical properties of the sulfonated polymer obtained at the same time, such as toughness such as elongation at break and bending resistance, and hot water resistance, are significantly impaired.

When these materials are used for electrodes, the same problem is pointed out, and the introduction position and chain of the sulfonic acid group are not regulated, so the catalyst particles and the sulfonic acid group cannot be effectively contacted. However, all the sulfonic acids cannot contribute to the conduction of protons generated by the catalyst, and there is a problem that the performance is lower than expected from the sulfonic acid concentration.
US Pat. No. 5,403,675

  The present invention has been made to solve the above-described problems of the prior art, and when used in an electrode, the polyarylene in which the reaction with the catalyst is efficiently performed, the production method thereof, and the poly An object of the present invention is to provide a solid polymer electrolyte containing arylene, a proton conductive membrane, and a battery electrode.

  The polymer of the present invention is defined so that sulfonic acid groups are introduced into the side chain, and the number of chains is regulated and introduced randomly into the polymer. And a method for producing the same, and a solid polymer electrolyte containing the polyarylene, a proton conductive membrane, and a battery electrode.

  That is, the polyarylene having a sulfonic acid group of the present invention is a structural unit represented by the following general formula (1);

(In formula (1), m represents an integer of 0 to 10, X represents a divalent organic group or a direct bond. When m is 1 or more, X may be the same or different from each other.)
And at least one selected from the structural unit represented by the following general formula (2) and the structural unit represented by the following general formula (3), the chain of structural units represented by the general formula (1) Characterized by an average number of 1.0 to 4.0;

(In formula (2), X represents a divalent organic group or a direct bond, and Ar represents an aromatic group.)

(In formula (3), X represents a divalent organic group or a direct bond). It is preferable that the structural unit represented by General formula (1) is 20 to 80 mol% with respect to all the structural units. The divalent organic group represented by X in the general formulas (1), (2) and (3) is preferably an electron-withdrawing group.

  The solid polymer electrolyte of the present invention is characterized by comprising the above polyarylene.

  The proton conducting membrane of the present invention is characterized by containing the above polyarylene.

  The battery electrode of the present invention includes the polyarylene described above.

  The method for producing a polyarylene having a sulfonic acid group according to the present invention is represented by a compound represented by the following general formula (4), a compound represented by the following general formula (5), and the following general formula (6). Polymerizing at least one selected from compounds and hydrolyzing the resulting copolymer;

(In the formula (4), R represents a hydrocarbon group, Z represents an atom or group selected from halogen atoms excluding fluorine, —OSO ₂ CH ₃ , and —OSO ₂ CF ₃ , and m represents an integer of 0 to 10. X represents a divalent organic group or a direct bond. When m is 1 or more, X may be the same or different from each other.

(In formula (5), Z represents a halogen atom excluding fluorine, an atom or group selected from —OSO ₂ CH ₃ , —OSO ₂ CF ₃ , X represents a divalent organic group or a direct bond, and Ar represents Indicates an aromatic group.)

(In formula (6), Z represents a halogen atom excluding fluorine, an atom or group selected from —OSO ₂ CH ₃ and —OSO ₂ CF ₃ , and X represents a divalent organic group or a direct bond.)

  According to the present invention, since the sulfonic acid group is defined to be introduced into the side chain, and the chain number is regulated and randomly introduced into the polymer, when used in the electrode, the catalyst and There are provided a polyarylene in which the above reaction is efficiently performed, a method for producing the same, a solid polymer electrolyte containing the polyarylene, a proton conductive membrane, and a battery electrode.

Hereinafter, the present invention will be specifically described.
(Polyarylene having a sulfonic acid group)
The polyarylene of the present invention is at least selected from a structural unit represented by the following general formula (1), a structural unit represented by the following general formula (2), and a structural unit represented by the following general formula (3). It consists of a kind.

  In the said General formula (1), m shows the integer of 0-10, Preferably, m is 0-3.

X represents a divalent organic group or a direct bond. When m is 1 or more, X may be mutually the same or different. As such an organic group, specifically, —CO—, —SO ₂ —,
Electron-withdrawing groups such as —SO—, —CONH—, —COO—, — (CF ₂ ) _p — (wherein p is an integer of 1 to 10), —C (CF ₃ ) ₂ —, _{CH 2 -, - C (CH} 3) 2 -, - O-
, -S-, and the like. 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 phenyl group is in the p-position. X is preferably an electron-withdrawing group.

  In the general formula (1), X represents a divalent organic group or a direct bond, and Ar represents an aromatic group. X may be the same as or different from the organic groups of the general formulas (1) and (3). Examples of such an organic group include the same groups as described above. X is preferably an electron-withdrawing group.

  Specific examples of the aromatic group represented by Ar include a phenyl group, a naphthyl group, a 4-phenylphenyl group, a 4-phenoxyphenyl group, a 4-fluorophenyl group, and a 2,4-difluorophenyl group. .

  In the general formula (3), X represents a divalent organic group or a direct bond. X may be the same as or different from the organic groups of the general formulas (1) and (2). Examples of such an organic group include the same groups as described above. X is preferably an electron-withdrawing group.

  In the polyarylene of the present invention, the average number of linkages between the structural units represented by the general formula (1) is 1.0 to 4.0. That is, the structural unit having a sulfonic acid group of the general formula (1) is randomly introduced into the polymer mainly in a sequence not constituting a long-chain block, and is formed on both sides of the structural unit having the sulfonic acid group of the general formula (1). An arrangement in which the structural units of the general formula (2) or (3) are adjacent is the main structure. From the viewpoint of sufficiently obtaining the effects of the present invention, the constitutional unit represented by the general formula (1) is preferably 20 to 80 mol%, more preferably 35 to the whole constitutional unit in the polymer. -65 mol%.

Thus, by constituting the polymer from the structural units of the general formulas (1), (2), and (3) with the ratio of each structural unit described above and the above-described arrangement, the sulfonic acid group is added to the side chain. A polyarylene which is introduced and has a regulated number of chains, and when used in an electrode, a reaction with a catalyst is efficiently performed, and a method for producing the same, and a solid polymer electrolyte containing the polyarylene,
Proton conducting membranes and battery electrodes are provided.
(Method for producing polyarylene having a sulfonic acid group)
The polyarylene of the present invention includes at least one selected from a compound represented by the following general formula (4), a compound represented by the following general formula (5), and a compound represented by the following general formula (6). Can be obtained by polymerizing in the presence of a catalyst and hydrolyzing the resulting copolymer.

In the general formula (4), R represents a hydrocarbon group, preferably a hydrocarbon group having 4 to 20 carbon atoms. Specifically, tert-butyl group, iso-butyl group, n-butyl group, sec-butyl group, neopentyl group, cyclopentyl group, hexyl group, cyclohexyl group, cyclopentylmethyl group, cyclohexylmethyl group, adamantylmethyl, adamantylmethyl Group, 2-ethylhexyl group, bicyclo [2.2.1] heptyl group, bicyclo [2.2.1] heptylmethyl group, tetrahydrofurfuryl group, 2-methylbutyl group, 3,3-dimethyl-2,4- Examples thereof include linear hydrocarbon groups such as a dioxolane methyl group, branched hydrocarbon groups, alicyclic hydrocarbon groups, and hydrocarbon groups having a 5-membered heterocyclic ring. Of these, a neopentyl group is preferred.

Z represents an atom or group selected from any halogen atom of chlorine, bromine and iodine, —OSO ₂ CH ₃ , —OSO ₂ CF ₃ . Each atom or group represented by two Z in the general formula (4) may be the same or different from each other. m shows the integer of 0-10, Preferably, m is 0-3. X represents a divalent organic group or a direct bond, and is specifically the same as X in the structural unit of the general formula (1). When m is 1 or more, X may be mutually the same or different.

In the general formula (5), Z represents an atom or group selected from any halogen atom of chlorine, bromine and iodine, —OSO ₂ CH ₃ and —OSO ₂ CF ₃ . X represents a divalent organic group or a direct bond, and is specifically the same as X in the structural unit of the general formula (2). Examples of such an organic group include the same groups as described above. X is preferably an electron-withdrawing group. Ar represents an aromatic group, and specific examples include a phenyl group, a naphthyl group, a 4-phenylphenyl group, a 4-phenoxyphenyl group, a 4-fluorophenyl group, and a 2,4-difluorophenyl group.

In the general formula (6), Z represents an atom or group selected from any halogen atom of chlorine, bromine and iodine, —OSO ₂ CH ₃ , —OSO ₂ CF ₃ . X represents a divalent organic group or a direct bond, and is specifically the same as X in the structural unit of the general formula (3). Examples of such an organic group include the same groups as described above. X is preferably an electron-withdrawing group.

  Polymerization is carried out in the presence of a catalyst from the monomer represented by the general formula (4) and at least one selected from the monomer represented by the general formula (5) and the monomer represented by the general formula (6). The catalyst used is a catalyst system containing a transition metal compound. This catalyst system includes 1) a compound that becomes a transition metal salt and a ligand (hereinafter referred to as “ligand component”), or coordination. A transition metal complex (including a copper salt) coordinated with a child, and 2) a reducing agent as an essential component, and a salt may be added to increase the polymerization rate.

  Here, as the transition metal salt, specifically, nickel compounds such as nickel chloride, nickel bromide, nickel iodide, nickel acetylacetonate; palladium compounds such as palladium chloride, palladium bromide, palladium iodide; Examples thereof include iron compounds such as iron, iron bromide and iron iodide; and cobalt compounds such as cobalt chloride, cobalt bromide and cobalt iodide. Among these, nickel chloride and nickel bromide are particularly preferable.

Specific examples of the ligand component include triphenylphosphine, 2,2′-bipyridine, 1,5-cyclooctadiene, 1,3-bis (diphenylphosphino) propane, and the like. Of these, triphenylphosphine and 2,2′-bipyridine are preferable. The compound which is the said ligand component can be used individually or in combination of 2 or more types.

Furthermore, as a transition metal complex in which a ligand is coordinated, specifically, 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. Among these, nickel chloride bis (triphenylphosphine) and nickel chloride (2,2′-bipyridine) are preferable.

  Specific 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 preferable. These reducing agents can be used by further activating them by contacting with an acid such as an organic acid.

  Specific 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 compounds such as potassium bromide, 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 preferable.

  The proportion of each component used is usually 0.0001 to 10 mol, preferably 0.01 to 0.5 mol, per 1 mol of the monomer unit used for the polymerization of the transition metal salt or transition metal complex. 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.

  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, per 1 mol of the transition metal salt. is there. 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 1 mol of monomer units used for superposition | polymerization, 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 1 mol of monomer units used for superposition | polymerization, 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.

Specific examples of the polymerization solvent include tetrahydrofuran, cyclohexanone, dimethyl sulfoxide, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, γ-butyrolactone, N, N′-dimethylimidazo. Lysinone 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 concentration of the monomer used for the polymerization in the polymerization solvent is usually 1 to 90% by mass, preferably 5 to 40% by mass.

  Moreover, the superposition | polymerization temperature at the time of superposing | polymerizing 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.

  After obtaining the copolymer in this way, the sulfonic acid ester group in the portion corresponding to the structural unit of the general formula (A) is hydrolyzed to a sulfonic acid group by a known method to obtain the polyarylene of the present invention. be able to.

  The amount of sulfonic acid groups in the copolymer of the present invention is 1.2 to 2.8 meq / g, preferably 1.5 to 2.5 meq / g. If it is less than 1.2 meq / g, the proton conductivity is low. On the other hand, if it exceeds 2.8 meq / g, it is not preferable because it becomes water-soluble.

  The molecular weight of the polyarylene having a sulfonic acid group of the present invention is 5,000 to 500,000, preferably 10,000 to 300,000 in terms of polystyrene-equivalent weight average molecular weight by GPC (gel permeation chromatography). If it is less than 5000, the mechanical strength is low and the water resistance is insufficient. On the other hand, if it exceeds 500,000, there are problems such as insufficient solubility, high solution viscosity, and poor processability.

The structure of the polyarylene having a sulfonic acid group is, for example, a C—O—C absorption of 1,230 to 1,250 cm ⁻¹ , a C═O absorption of 1,640 to 1,660 cm ⁻¹ by infrared absorption spectrum, and the like. Further, the structure can be confirmed from the peak of the aromatic proton at 6.8 to 8.5 ppm by nuclear magnetic resonance spectrum ( ¹ H-NMR).
(Polymer solid electrolyte)
The polymer solid electrolyte of the present invention comprises polyarylene having a sulfonic acid group as described above.

The polymer solid electrolyte of the present invention includes, for example, an electrolyte for a primary battery, an electrolyte for a secondary battery, a polymer solid electrolyte for a fuel cell, an electrolyte for a direct methanol fuel cell, a display element, various sensors, a signal transmission medium, a solid capacitor, It can be used for ion exchange membranes.
(Proton conducting membrane)
The proton conducting membrane of the present invention is prepared by, for example, dissolving the above-described polyarylene having a sulfonic acid group of the present invention (hereinafter simply referred to as “polyarylene having a sulfonic acid group”) in a solvent, followed by casting. The film is produced by casting on a substrate and forming into a film by a method (casting method) or the like. The substrate is not particularly limited as long as it is a substrate used in an ordinary solution casting method. For example, a substrate made of plastic or metal is used, and preferably a thermoplastic resin such as a polyethylene terephthalate (PET) film. A substrate is used.

  In preparing the proton conducting membrane, in addition to polyarylene having a sulfonic acid group, an inorganic acid such as sulfuric acid or phosphoric acid, an organic acid containing a carboxylic acid, an appropriate amount of water, or the like may be used in combination.

Specific examples of the solvent for dissolving the polyarylene having a sulfonic acid group include N-methyl-2-pyrrolidone, N, N-dimethylformamide, γ-butyrolactone, N, N-dimethylacetamide, dimethyl sulfoxide, and dimethylurea. And aprotic polar solvents such as dimethylimidazolidinone (DMI), and N-methyl-2-pyrrolidone is particularly preferred from the viewpoint of solubility and solution viscosity. Aprotic polar solvents can be used alone or in combination of two or more.

  Moreover, you may use the mixture of an above-mentioned aprotic polar solvent and alcohol as a solvent which dissolves the polyarylene which has a sulfonic acid group. Specific examples of the alcohol include methanol, ethanol, propyl alcohol, iso-propyl alcohol, sec-butyl alcohol, tert-butyl alcohol, etc. Methanol is particularly preferable because it has an effect of reducing the solution viscosity in a wide composition range. . Alcohol can be used individually or in combination of 2 or more types.

  When a mixture of an aprotic polar solvent and an alcohol is used as the solvent, the aprotic polar solvent is 25 to 95% by mass, preferably 25 to 90% by mass, and the alcohol is 5 to 75% by mass, preferably 10 to 10%. A mixture having a composition of 75% by weight is used. When the amount of alcohol is within the above range, the effect of lowering the solution viscosity is excellent.

  The polymer concentration of the solution in which the polyarylene having a sulfonic acid group is dissolved is usually 5 to 40% by mass, preferably 7 to 25% by mass, although it depends on the molecular weight of the polyarylene having a sulfonic acid group. If it is less than 5% by mass, it is difficult to form a thick film, and pinholes are easily generated. On the other hand, if it exceeds 40% by mass, the solution viscosity is too high to form a film, and surface smoothness may be lacking.

The solution viscosity is usually 2,000 to 100,000 mPa · s, preferably 3,000 to 50,000 mPa · s, although it depends on the molecular weight of the polyarylene having a sulfonic acid group and the polymer concentration. If it is less than 2,000 mPa · s, the retention of the solution during film formation is poor,
May flow from the substrate. On the other hand, if it exceeds 100,000 mPa · s, the viscosity is too high to be extruded from the die and it may be difficult to form a film by the casting method.

  After forming the film as described above, by immersing the obtained undried film in water, the organic solvent in the undried film is replaced with water, and the residual solvent amount of the resulting proton conducting membrane is reduced. Can do.

  In addition, you may pre-dry an undried film before immersing an undried film in water after film-forming. The preliminary drying is performed by holding the undried film at a temperature of usually 50 to 150 ° C. for 0.1 to 10 hours.

  When immersing an undried film in water, for example, a batch method in which a sheet is immersed in water is employed. Alternatively, a continuous method is adopted in which the laminated film is immersed in water in a state where the film is formed on a substrate film such as PET, or the film separated from the substrate is immersed in water and wound.

  In the case of the batch method, a method of fitting the treated film to the frame is preferable in that wrinkle formation on the surface of the treated film is suppressed.

When immersing an undried film in water, it is preferable that water has a contact ratio of 10 parts by mass or more, preferably 30 parts by mass or more with respect to 1 part by mass of the undried film. In order to minimize the amount of residual solvent in the resulting proton conducting membrane, it is preferable to maintain a contact ratio as large as possible. In addition, it is effective in reducing the amount of residual solvent in the resulting proton conducting membrane by changing the water used for immersion or allowing it to overflow so that the organic solvent concentration in the water is always kept below a certain level. is there. In order to suppress the in-plane distribution of the amount of the organic solvent remaining in the proton conductive membrane, it is preferable to homogenize the concentration of the organic solvent in water by stirring or the like.

  The temperature of water when the undried film is immersed in water is preferably 5 to 80 ° C. The higher the temperature, the higher the rate of substitution between the organic solvent and water, but the greater the amount of water absorbed by the film, so the surface of the proton conducting membrane obtained after drying may become rough. Considering the replacement speed and ease of handling, a temperature range of 10 to 60 ° C. is more preferable.

  The immersion time is usually 10 minutes to 240 hours, preferably 30 minutes to 100 hours, although depending on the initial residual solvent amount, contact ratio, and treatment temperature.

  Thus, when an undried film is immersed in water and then dried, a proton conductive membrane with a reduced amount of residual solvent is obtained, and the residual solvent amount in the proton conductive membrane is usually 5% by mass or less.

  Further, for example, the contact ratio between the undried film and water is 50 parts by mass or more of water with respect to 1 part by mass of the undried film, the temperature of water at the time of immersion is 10 to 60 ° C., and the immersion time is 10 minutes. By setting it to 10 hours, the residual solvent amount of the proton conductive membrane obtained can be made 1 mass% or less.

  As described above, after immersing the undried film in water, the film is dried at 30 to 100 ° C., preferably 50 to 80 ° C., for 10 to 180 minutes, preferably 15 to 60 minutes, and then 50 to 150 ° C. Then, the proton conducting membrane is obtained by vacuum drying under reduced pressure of 0.5 mm to 24 mm, preferably 500 mmHg to 0.1 mmHg.

  The proton conducting membrane thus obtained has a dry film thickness of usually 10 to 100 μm, preferably 20 to 80 μm.

  The proton conducting membrane of the present invention may contain an anti-aging agent, preferably a hindered phenol compound having a molecular weight of 500 or more. By containing an anti-aging agent, the durability of the proton conducting membrane is further improved. Can do.

As such a hindered phenol compound having a molecular weight of 500 or more, specifically, triethylene glycol-bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) proonate] (trade name: IRGANOX 245) 1,6-hexanediol-bis [3- (3,5-di-tert-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) Product name: IRGANOX 1035), octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate) (trade name: IRGANOX 1076), N, N-hexamethylenebis (3,5-di-) t-butyl-4-hydroxy-hydrocinnamamide) (IRGAONOX 1098), 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene ( Trade name: IRGANOX 1330), tris- (3,5-di-t-butyl-4-hydroxybenzyl) -isocyanurate (trade name: IRGANOX 3114), 3,9-bis [2- [3- (3 -T-butyl-4-hydroxy-5-methylphenyl) propionyloxy] -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5.5] undecane (trade name: Sumilizer GA- 80).

These hindered phenol compounds are preferably used in an amount of 0.01 to 10 parts by mass with respect to 100 parts by mass of the polyarylene having a sulfonic acid group.
(Battery electrode)
The battery electrode of the present invention is prepared, for example, by applying a paste comprising the catalyst fine particles having hydrogen reducing ability supported on conductive porous particles and the sulfonated polyarylene of the present invention to a gas diffusion electrode substrate. The

  As the conductive porous particles, those having a high structure and a large specific surface area such as ketjen black and acetylene black are usually used. As the catalyst having hydrogen reducing ability, noble metals such as platinum, palladium, ruthenium and rhodium, and alloys of these metals with metals such as chromium, molybdenum, tungsten, titanium, zirconium and cobalt are used. The amount of catalyst metal supported is usually 10 to 60% by mass with respect to the conductive porous particles.

  The electrode substrate is prepared by applying a paste composed of catalyst fine particles and a polymer electrolyte component to a porous gas diffusion electrode substrate such as carbon paper or carbon cloth by a coating method such as a doctor blade or a spray.

The film thickness of the electrode substrate is usually 5 to 100 μm, preferably 5 to 50 μm.
[Example]
EXAMPLES Hereinafter, although this invention is demonstrated further more concretely based on an Example, this invention is not limited to these Examples.

In the following examples, measurement and evaluation of sulfonic acid equivalent weight and molecular weight were performed as follows.
1. Sulfonic acid equivalent The resulting polyarylene having a sulfonic acid group was washed until the washing water became neutral to sufficiently remove the free remaining acid. After drying this, a predetermined amount was weighed and dissolved in a THF / water mixed solvent, titrated with a standard solution of NaOH using phenolphthalein as an indicator, and the sulfonic acid equivalent was determined from the neutralization point.
2. Measurement of molecular weight Regarding the number average molecular weight and weight average molecular weight of polyarylene having no sulfonic acid group, tetrahydrofuran (THF) was basically used as a solvent, and the molecular weight in terms of polystyrene was determined by GPC. Regarding the number average molecular weight and the weight average molecular weight of the polyarylene having a sulfonic acid group, N-methyl-2-pyrrolidone (NMP) to which lithium bromide and phosphoric acid are added is basically used as a solvent as an eluent, and polystyrene is obtained by GPC. The converted molecular weight was determined.
3. Hot Water Resistance Test A sulfonated polyarylene film was cut into 2.0 cm × 3.0 cm, weighed, and used as a test piece for a hot water resistance test. This film was placed in a polycarbonate 250 ml bottle, about 100 ml of distilled water was added thereto, and the mixture was heated at 120 ° C. for 24 hours using a pressure cooker tester (HIRAYAMA MFS CORP PC-242HS). After completion of the test, each film was taken out from hot water, dried in a vacuum dryer for 5 hours, water was distilled off, and the weight after the hot water test was weighed to determine the weight retention.
4). Fenton reagent resistance Commercial 30% hydrogen peroxide solution is diluted with distilled water to 3%, and ferrous sulfate heptahydrate is added to this so that Fe (II) ions in the solution become 20 ppm, Dissolved to prepare Fenton reagent. 200 ml of this solution was poured into a 250 ml plastic bottle and heated using a water bath so as to be constant at 45 ° C. After confirming that the solution reached 45 ° C., each film was added and heated for 10 hours. After 26 hours, the solid was taken out from the solution, air-dried overnight, weighed, and the weight residual ratio was determined.
5). Measurement of proton conductivity AC resistance is obtained by pressing a platinum wire (φ = 0.5 mm) on the surface of a strip-shaped membrane sample with a width of 5 mm, holding the sample in a constant temperature and humidity device, and alternating current impedance between platinum wires. Obtained from measurement. That is, the impedance at AC 10 kHz was measured in an environment of 85 ° C. and relative humidity 90%. A chemical impedance measurement system manufactured by NF Circuit Design Block Co., Ltd. was used as the resistance measurement device, and JW241 manufactured by Yamato Scientific Co., Ltd. was used as the constant temperature and humidity device. Five platinum wires were pressed at intervals of 5 mm, the distance between the wires was changed to 5 to 20 mm, and the AC resistance was measured. The specific resistance of the membrane was calculated from the line-to-line distance and the resistance gradient, the AC impedance was calculated from the reciprocal of the specific resistance, and the proton conductivity was calculated from this impedance.

  Specific resistance R (Ω · cm) = 0.5 (cm) × film thickness (cm) × resistance-to-resistance gradient (Ω / cm)

(1) Synthesis of polyarylene In a 1000 mL three-necked flask equipped with a stirring blade, a thermometer, and a nitrogen inlet tube, 90.3 g (225 mmol) of neopentyl 3- (2,5-dichlorobenzoyl) benzenesulfonate, 2,5 -Dichlorobenzophenone 69.1 g (275 mmol), 4-chlorobenzophenone 1.08 g (5 mmol), bis (triphenylphosphine) nickel dichloride 9.81 g (15 mmol), sodium iodide 2.25 g (15 mmol), triphenylphosphine 52 0.5 g (200 mmol) and 78.4 g (1200 mmol) of zinc were added. After the inside of the flask was vacuum-dried for 2 hours, 373 mL of dimethylacetamide (DMAc) that had been purged with dry nitrogen and dehydrated was added to initiate polymerization.

The polymerization was continued for 3 hours while controlling the reaction temperature not to exceed 90 ° C. Next, 1400 mL of DMAc was added to dilute the polymerization solution, and the insoluble part was filtered. The filtrate was poured into 10 L of methanol to solidify the polymer. The precipitated polymer was vacuum dried to obtain 120 g of polyarylene. The number average molecular weight of the product determined by GPC was 39000, and the weight average molecular weight was 153000.
(2) Synthesis of sulfonated polyarylene 120 g of polyarylene, 970 mL of DMAc, and 29.3 g (338 mmol) of lithium bromide were added to a 300 mL three-necked flask equipped with a stirring blade, a thermometer, and a nitrogen introduction tube, and the mixture was stirred at 120 ° C. for 7 hours. did. The reaction solution was poured into 5 L of acetone to solidify the polymer. The obtained solid was treated twice with distilled water / concentrated hydrochloric acid solution (3.0 L / 0.37 L), and then washed with distilled water until the pH became neutral. It dried at 70 degreeC for 12 hours, and obtained the sulfonated polyarylene 100g. The ion exchange capacity of this polymer was 1.97 meq / g.

  A polyarylene was obtained in the same manner as in Example 1 except that the amount of 4-chlorobenzophenone charged in Example 1 was changed to 3.68 g (17 mmol). The product obtained by GPC had a number average molecular weight of 14,000 and a weight average molecular weight of 42,000.

  The obtained polyarylene was converted to a sulfonated polyarylene by the same operation as in Example 1. The ion exchange capacity of the obtained polymer was 1.98 meq / g.

  Data of various properties of the copolymers obtained in Examples 1 and 2 are shown in Table 1 (sulfonated polyetheretherketone (S-PEEK) was used as Comparative Example 1).

Claims (7)

A structural unit represented by the following general formula (1);

(In formula (1), m represents an integer of 0 to 10, X represents a divalent organic group or a direct bond. When m is 1 or more, X may be the same or different from each other.)
And at least one selected from the structural unit represented by the following general formula (2) and the structural unit represented by the following general formula (3), the chain of structural units represented by the general formula (1) A polyarylene having a sulfonic acid group, characterized in that the average of the numbers is from 1.0 to 4.0;

(In formula (2), X represents a divalent organic group or a direct bond, and Ar represents an aromatic group.)

(In formula (3), X represents a divalent organic group or a direct bond).   The polyarylene according to claim 1, wherein the structural unit represented by the general formula (1) is 20 to 80 mol% with respect to all the structural units. The polyarylene according to claim 1 or 2, wherein the divalent organic group represented by X in the general formulas (1), (2) and (3) is an electron-withdrawing group.   A polymer solid electrolyte comprising the polyarylene according to any one of claims 1 to 3.   A proton conducting membrane comprising the polyarylene according to claim 1.   A battery electrode comprising the polyarylene according to claim 1. Obtained by polymerizing a compound represented by the following general formula (4) and at least one selected from a compound represented by the following general formula (5) and a compound represented by the following general formula (6) A process for producing a polyarylene having a sulfonic acid group, which comprises hydrolyzing a copolymer;

(In the formula (4), R represents a hydrocarbon group, Z represents an atom or group selected from halogen atoms excluding fluorine, —OSO ₂ CH ₃ , and —OSO ₂ CF ₃ , and m represents an integer of 0 to 10. X represents a divalent organic group or a direct bond. When m is 1 or more, X may be the same or different from each other.

(In formula (5), Z represents a halogen atom excluding fluorine, an atom or group selected from —OSO ₂ CH ₃ , —OSO ₂ CF ₃ , X represents a divalent organic group or a direct bond, and Ar represents Indicates an aromatic group.)

(In formula (6), Z represents a halogen atom excluding fluorine, an atom or group selected from —OSO ₂ CH ₃ and —OSO ₂ CF ₃ , and X represents a divalent organic group or a direct bond.)