JP2007112906A - Polymer electrolyte composition containing aromatic hydrocarbon-based resin and cage-like silsesquioxane - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a proton exchange membrane which has high durability even under high temperature low humidity conditions [for example, operation temperature of 100°C, 50°C humidification (corresponding to a humidity of 12 RH)]. <P>SOLUTION: This polymer electrolyte composition comprises an ion exchange group-having polymer (A), polyphenylene sulfide resin (B), polyphenylene ether (C), and a cage-like silsesquioxane or cage-like silsesquioxane partial cleavage structure (D), and a proton exchange membrane comprises the polymer electrolyte composition. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a polymer electrolyte composition and a proton exchange membrane for a polymer electrolyte fuel cell comprising the same.

A fuel cell is one that converts the chemical energy of fuel directly into electrical energy by electrochemically oxidizing hydrogen, methanol, etc. in the battery, and is attracting attention as a clean electrical energy supply source. ing. In particular, polymer electrolyte fuel cells are expected to be used as alternative power sources for automobiles, home cogeneration systems, portable generators, and the like because they operate at a lower temperature than others.
Such a polymer electrolyte fuel cell includes at least a membrane electrode assembly in which a gas diffusion electrode in which an electrode catalyst layer and a gas diffusion layer are laminated is bonded to both surfaces of a proton exchange membrane. The proton exchange membrane here is a material having a strong acidic group such as a sulfonic acid group and a carboxylic acid group in the polymer chain and a property of selectively transmitting protons. As such a proton exchange membrane, a perfluoro proton exchange membrane represented by Nafion (registered trademark, manufactured by DuPont) having high chemical stability is preferably used.

  During operation of the fuel cell, fuel (for example, hydrogen) is supplied to the gas diffusion electrode on the anode side, and an oxidant (for example, oxygen or air) is supplied to the gas diffusion electrode on the cathode side. Operates by connecting. Specifically, when hydrogen is used as a fuel, hydrogen is oxidized on the anode catalyst to generate protons, and after passing through the proton conductive polymer in the anode catalyst layer, the protons move in the proton exchange membrane, It reaches the cathode catalyst through the proton conducting polymer in the cathode catalyst layer. On the other hand, electrons generated simultaneously with protons by oxidation of hydrogen reach the cathode side gas diffusion electrode through an external circuit, and react with the protons and oxygen in the oxidant on the cathode catalyst to generate water, At this time, electric energy can be taken out.

At this time, the proton exchange membrane also needs to play a role as a gas barrier. When the gas permeability of the proton exchange membrane is high, leakage of anode-side hydrogen to the cathode side and leakage of cathode-side oxygen to the anode side, that is, A cross leak occurs, so that a so-called chemical short circuit occurs and a good voltage cannot be taken out.
Such a polymer electrolyte fuel cell is usually operated near 80 ° C. in order to obtain high output characteristics. However, when used for automobiles, the fuel cell can be operated even under high-temperature and low-humidification conditions (operating temperature near 100 ° C., 50 ° C. humidification (corresponding to a humidity of 12 RH%)) assuming that the vehicle is driven in summer. It is desired. However, when a fuel cell is operated for a long time under a high temperature and low humidity condition using a conventional perfluoro proton exchange membrane, there is a problem that pinholes are generated in the proton exchange membrane, and cross leaks occur. Is not obtained.

As methods for improving the durability of perfluoro proton exchange membranes, reinforcement using fibrillar polytetrafluoroethylene (PTFE) (Patent Documents 1 and 2) and reinforcement using a stretched PTFE porous membrane (Patent Documents) 3) Reinforcement using inorganic particles (Patent Documents 4, 5, and 6) and studies using a porous body made of an aromatic ring-containing resin (Patent Documents 7 and 8) are disclosed. However, in these methods, it has not been achieved to obtain a durability sufficient to solve the above problems.
JP-A-53-149981 Japanese Examined Patent Publication No. 63-61337 JP-A-8-162132 JP-A-6-1111827 JP-A-9-219206 US Pat. No. 5,523,181 JP 2001-514431 A JP 2003-297393 A

  An object of the present invention is to provide a polymer electrolyte composition having high durability even under high-temperature and low-humidity conditions (for example, at an operating temperature of 100 ° C. and 50 ° C. humidification (corresponding to a humidity of 12 RH%)), and the polymer electrolyte composition. It is providing the proton exchange membrane which becomes.

As a result of intensive studies to solve the above problems, the present inventors,
Polymer compound (A) having an ion exchange group, polyphenylene sulfide resin (B), polyphenylene ether resin (C), and caged silsesquioxane or partially cleaved structure of caged silsesquioxane (D) The polymer electrolyte composition consisting of the above shows high oxidation stability, and the proton exchange membrane made of the polymer electrolyte composition has very good high durability even under high temperature and low humidity, and improved mechanical properties I found out.

That is, the present invention is as follows.
[1] Polymer compound (A) having an ion exchange group, polyphenylene sulfide resin (B), polyphenylene ether resin (C), and cage-shaped silsesquioxane or partially-cleaved structure of cage-shaped silsesquioxane A polymer electrolyte composition comprising (D).
[2] Polymer compound (A) having an ion exchange group, polyphenylene sulfide resin (B), polyphenylene ether resin (C), and cage-shaped silsesquioxane or partially-cleaved structure of cage-shaped silsesquioxane A polymer electrolyte composition comprising (D) and an epoxy group-containing compound (E).
[3] The polymer electrolyte composition according to [2], wherein the epoxy group-containing compound (E) is a homopolymer or copolymer (F) of an unsaturated monomer having an epoxy group.

[4] The polymer electrolyte composition according to [2], wherein the epoxy group-containing compound (E) is an epoxy resin (G).
[5] The polymer electrolyte composition according to [2], wherein the polyphenylene ether resin (C) and the epoxy resin (G) in the polymer electrolyte composition are reacted with each other. A polymer electrolyte composition containing at least
[6] The polymer electrolyte composition according to [1] or [2], wherein the polymer compound (A) having an ion exchange group is a perfluorocarbon polymer compound having an ion exchange group.

[7] The polymer electrolyte composition as described in [6], wherein the perfluorocarbon polymer compound having an ion exchange group has a structural unit represented by the following general formula (1).
-[CF ₂ CX ¹ X ² ] _a- [CF ₂ -CF (-O- (CF ₂ -CF (CF ₂ X ³ )) _b -O _c- (CFR ¹ ) _d- (CFR ² ) _e- ( CF ₂ ) _f -X ⁴ )] _g- (1) (wherein X ¹ , X ² and X ³ are each independently a halogen element or a perfluoroalkyl group having 1 to 3 carbon atoms, 0 ≦ a <1 , 0 <g ≦ 1, a + g = 1, b is an integer of 0 or more and 8 or less, c is 0 or 1, and d, e and f are each independently an integer of 0 or more and 6 or less (where d + e + f is 0) R ¹ and R ² are each independently a halogen element, a perfluoroalkyl group or a fluorochloroalkyl group having 1 to 10 carbon atoms, and X ⁴ is COOZ, SO ₃ Z, PO ₃ Z _2. , PO ₃ HZ (Z is a hydrogen atom, an alkali metal atom, an alkaline earth metal atom, an amine (NH ₄ , NH ₃ R, NH ₂ R ₂ , NHR ₃ , NR ₄ (R is Alkyl group or arene group))

[8] A proton exchange membrane comprising the polymer electrolyte composition according to any one of [1] to [7].
[9] A membrane electrode assembly having the proton exchange membrane according to [8].
[10] A polymer electrolyte fuel cell having the membrane electrode assembly according to [9].

The proton exchange membrane comprising the polymer electrolyte composition of the present invention is excellent in that no cross leak occurs even when the fuel cell is operated for a long period of time at an operating temperature of 100 ° C. and humidified at 50 ° C. (equivalent to a humidity of 12 RH%). Because of its high durability, it has become possible to obtain a proton exchange membrane having high durability even under high temperature and low humidification conditions (for example, at an operating temperature of 100 ° C. and 50 ° C. humidification (equivalent to a humidity of 12 RH%)). .
The proton exchange membrane obtained by the present invention can also be used in various fuel cells including direct methanol fuel cells, water electrolysis, hydrohalic acid electrolysis, salt electrolysis, oxygen concentrators, humidity sensors, gas sensors, etc. is there.

The present invention is described in detail below.
The polymer compound (A) having an ion exchange group used in the present invention is not particularly limited, but is a perfluorocarbon polymer compound having an ion exchange group or a hydrocarbon polymer compound having an aromatic ring in the molecule. Those obtained by introducing an ion exchange group into are preferable.
Specific examples of the hydrocarbon polymer compound having an aromatic ring in the molecule include polyphenylene sulfide, polyphenylene ether, polysulfone, polyether sulfone, polyether ether sulfone, polyether ketone, polyether ether ketone, and polythioether ether. Sulfone, polythioetherketone, polythioetheretherketone, polybenzimidazole, polybenzoxazole, polyoxadiazole, polybenzoxazinone, polyxylylene, polyphenylene, polythiophene, polypyrrole, polyaniline, polyacene, polycyanogen, polynaphthyridine, polyphenylene sulfide sulfone, Polyphenylenesulfone, polyimide, polyetherimide, polyesterimide, polyamideimide, polyester Examples include arylates, aromatic polyamides, polystyrenes, polyesters and polycarbonates. From the viewpoint of heat resistance, oxidation resistance and hydrolysis resistance, polyphenylene sulfide, polyphenylene ether, polysulfone, polyethersulfone, polyetherethersulfone, polyether Ketone, polyetheretherketone, polythioetherethersulfone, polythioetherketone, polythioetheretherketone, polybenzimidazole, polybenzoxazole, polyoxadiazole, polybenzoxazinone, polyxylylene, polyphenylene, polythiophene, polypyrrole, polyaniline, polyacene , Polycyanogen, polynaphthyridine, polyphenylene sulfide sulfone, polyphenylene sulfone, poly Imides, polyetherimides are preferred. Examples of the ion exchange group to be introduced into these include a sulfonic acid group, a sulfonimide group, a sulfonamide group, a carboxylic acid group, and a phosphoric acid group, and a sulfonic acid group is particularly preferable.

As the polymer compound (A) having an ion exchange group used in the present invention, a perfluorocarbon polymer compound having an ion exchange group is particularly suitable.
As the perfluorocarbon polymer compound having an ion exchange group, a sulfonic acid polymer of perfluorocarbon, a carboxylic acid polymer, a sulfonimide polymer, a sulfonamide polymer, a phosphoric acid polymer, or an amine salt or a metal salt thereof is preferably used. Specific examples include a polymer represented by the general formula (1).
-[CF ₂ CX ¹ X ² ] _a- [CF ₂ -CF (-O- (CF ₂ -CF (CF ₂ X ³ )) _b -O _c- (CFR ¹ ) _d- (CFR ² ) _e- ( CF ₂ ) _f -X ⁴ )] _g- (1)
(Wherein X ¹ , X ² and X ³ are each independently a halogen element or a perfluoroalkyl group having 1 to 3 carbon atoms, 0 ≦ a <1, 0 <g ≦ 1, a + g = 1, b is 0 An integer of 8 or less, c is 0 or 1, d, e and f are each independently an integer of 0 or more and 6 or less (where d + e + f is not equal to 0), and R ¹ and R ² are each independently A halogen element, a perfluoroalkyl group or a fluorochloroalkyl group having 1 to 10 carbon atoms, and X ⁴ is COOZ, SO ₃ Z, PO ₃ Z ₂ , PO ₃ HZ (Z is a hydrogen atom, an alkali metal atom, Alkaline earth metal atoms, amines (NH ₄ , NH ₃ R, NH ₂ R ₂ , NHR ₃ , NR ₄ (R is an alkyl group or arene group))

Among these, a perfluorocarbon sulfonic acid polymer represented by the general formula (2) or (3) or a metal salt thereof is particularly preferable.
-[CF ₂ CF ₂ ] _a- [CF ₂ -CF (-O-CF ₂ -CF (CF ₃ )) _b -O- (CF ₂ ) _c -SO ₃ X]] _d- (2)
(Wherein 0 ≦ a <1, 0 ≦ d <1, a + d = 1, b is an integer of 1 to 8, c is an integer of 0 to 10, and X is a hydrogen atom or an alkali metal atom)
-[CF ₂ CF ₂ ] _e- [CF ₂ -CF (-O- (CF ₂ ) _f -SO ₃ Y)] _g- (3)
(Wherein 0 ≦ e <1, 0 ≦ g <1, e + g = 1, f is an integer of 0 to 10 and Y is a hydrogen atom or an alkali metal atom)

The perfluorocarbon polymer compound having an ion exchange group of the present invention can be produced, for example, by polymerizing a precursor polymer represented by the general formula (4) and then performing alkali hydrolysis, acid treatment, and the like.
-[CF ₂ CX ¹ X ² ] _a- [CF ₂ -CF (-O- (CF ₂ -CF (CF ₂ X ³ )) _b -O _c- (CFR ¹ ) _d- (CFR ² ) _e- ( CF ₂ ) _f -X ⁵ )] _g- (4)
(Wherein X ¹ , X ² and X ³ are each independently a halogen element or a perfluoroalkyl group having 1 to 3 carbon atoms, 0 ≦ a <1, 0 <g ≦ 1, a + g = 1, b Is an integer of 0 to 8, c is 0 or 1, d, e and f are each independently an integer of 0 to 6 (where d + e + f is not equal to 0), R ¹ and R ² Are each independently a halogen element, a perfluoroalkyl group or fluorochloroalkyl group having 1 to 10 carbon atoms, X ⁵ is COOR ³ , COR ⁴ or SO ₂ R ⁴ (R ³ is a carbon number of 1 to 3) Hydrocarbon alkyl group, R ⁴ is a halogen element))

The precursor polymer that can be used in the present invention is produced by copolymerizing a fluorinated olefin compound and a vinyl fluoride compound.
Specific examples of the fluorinated olefin compound include CF ₂ = CF ₂ , CF ₂ = CFCl, CF ₂ = CCl _{2 and the} like.
Moreover, as a specific vinyl fluoride compound,
_{CF 2 = CFO (CF 2)} z -SO 2 F, CF 2 = CFOCF 2 CF (CF 3) O (CF 2) z -SO 2 F, CF 2 = CF (CF 2) z -SO 2 F, CF _{2 = CF (OCF 2 CF (} CF 3)) z - (CF 2) z-1 -SO 2 F, CF 2 = CFO (CF 2) z -CO 2 R, CF2 = CFOCF 2 CF (CF 3) O _{(CF 2) z -CO 2 R} , CF 2 = CF (CF 2) z -CO 2 R, CF 2 = CF (OCF 2 CF (CF 3)) z - (CF 2) 2 -CO 2 R (Z Is an integer of 1 to 8, and R represents a hydrocarbon alkyl group having 1 to 3 carbon atoms).

As a polymerization method of the precursor polymer, a solution polymerization method in which a vinyl fluoride compound is dissolved in a solvent such as chlorofluorocarbon and then reacted with a gas of a fluorinated olefin compound to perform polymerization, or a block shape in which polymerization is performed without using a solvent such as chlorofluorocarbon General polymerization methods such as a polymerization method, an emulsion polymerization method in which a vinyl fluoride compound is mixed with a surfactant in water and emulsified, and then reacted with a gas of a fluorinated olefin compound for polymerization.
In the present invention, in addition to a vinyl fluoride compound and a fluorinated olefin compound, a copolymer containing a third component such as a perfluoroolefin such as hexafluoropropylene or chlorotrifluoroethylene or a perfluoroalkyl vinyl ether may be used. Good.
The melt index MI (g / 10 min) of the precursor polymer that can be used in the present invention, measured at 270 ° C., load 21.2 N, orifice inner diameter 2.09 mm based on JIS K-7210 is 0.00. 001 or more and 1000 or less are preferable, more preferably 0.01 or more and 100 or less, and most preferably 0.1 or more and 10 or less.

Next, the precursor polymer that can be used in the present invention is immersed in a basic reaction liquid and subjected to an alkali hydrolysis treatment. The reaction liquid is preferably an aqueous solution of an alkali metal or alkaline earth metal hydroxide such as potassium hydroxide or sodium hydroxide. The content of alkali metal or alkaline earth metal hydroxide is preferably 10% by weight or more and 30% by weight or less. The reaction liquid preferably contains a swellable organic compound such as dimethyl sulfoxide or methanol. The content of the swellable organic compound is preferably 1% by weight or more and 30% by weight or less.
After the precursor polymer is subjected to an alkali hydrolysis treatment, and further subjected to an acid treatment with hydrochloric acid or the like as necessary, a perfluorocarbon polymer compound having an ion exchange group is produced.

  Next, the polyphenylene sulfide resin (B) of the present invention (hereinafter sometimes abbreviated as PPS) is not particularly limited as long as it is a so-called polyphenylene sulfide resin, but preferably has a paraphenylene sulfide skeleton of 70 mol% or more, more preferably. Is a polyphenylene sulfide resin comprising 90 mol% or more.

  The production method of PPS is not particularly limited. Usually, a halogen-substituted aromatic compound such as p-dichlorobenzene is polymerized in the presence of sulfur and sodium carbonate, and p-dichlorobenzene is polymerized in a polar solvent. A method of polymerizing in the presence of sodium sulfide or sodium hydrogen sulfide and sodium hydroxide, or a method of polymerizing p-dichlorobenzene in the presence of hydrogen sulfide and sodium hydroxide or sodium aminoalkanoate in a polar solvent, p- Examples include self-condensation of chlorothiophenol. Among these, a method in which sodium sulfide and p-dichlorobenzene are reacted in an amide solvent such as N-methylpyrrolidone or dimethylacetamide or a sulfone solvent such as sulfolane is suitable. Specifically, US Pat. No. 2,513,188, Japanese Patent Publication No. 44-27671, Japanese Patent Publication No. 45-3368, Japanese Patent Publication No. 52-12240, Japanese Patent Publication No. 61-225217, US Pat. No. 3,274,165. No. 1, British Patent No. 1160660, Japanese Patent Publication No. Sho 46-27255, Belgian Patent No. 29437, Japanese Patent Laid-Open No. 5-222196, etc. It can be obtained by technical methods.

The polyphenylene sulfide resin (B) used in the present invention has an oligomer extraction amount of 0.001 wt% or more and 0.9 wt% or less with methylene chloride, and a —SX group (S is a sulfur atom, X is an alkali metal or A polyphenylene sulfide resin having a hydrogen atom of 10 μmol / g or more and 10,000 μmol / g or less is preferable.
The amount of oligomer extracted with methylene chloride is more preferably 0.001 wt% or more and 0.8 wt% or less, and particularly preferably 0.001 wt% or more and 0.7 wt% or less. That the amount of oligomer extracted with methylene chloride is in the above range means that the amount of oligomer (about 10 to 30 mer) in PPS is small. If the amount of oligomer extraction exceeds the above range, bleeding out tends to occur during film formation, which is not preferable.

  Here, the amount of oligomer extracted with methylene chloride can be measured by the following method. That is, 5 g of PPS powder is added to 80 ml of methylene chloride, Soxhlet extraction is performed for 4 hours, and then cooled to room temperature, and the methylene chloride solution after extraction is transferred to a weighing bottle. Further, the container used for the above extraction is washed in three portions with a total of 60 ml of methylene chloride, and the washing liquid is collected in the weighing bottle. Next, the methylene chloride in the weighing bottle is evaporated and removed by heating to about 80 ° C., the residue is weighed, and the ratio of the amount of oligomer present in the PPS can be determined from the amount of the residue.

  The content of the —SX group (S is a sulfur atom, X is an alkali metal or hydrogen atom) is more preferably 15 μmol / g or more and 10,000 μmol / g or less, more preferably 20 μmol / g or more and 10,000 μmol / g. The following are particularly preferred: The fact that the -SX group concentration is in the above range means that there are many reaction active sites of the polyphenylene sulfide resin. -By using the polyphenylene sulfide resin (B) in which the SX group concentration satisfies the above range, the miscibility between the polymer compound (A) having an ion exchange group and the polyphenylene sulfide resin is improved in the polymer electrolyte composition of the present invention. It is considered that the dispersibility of the polyphenylene sulfide resin (B) in the polymer compound (A) having an ion exchange group is improved.

  Here, quantification of the -SX group can be performed by the following method. That is, after the PPS powder was previously dried at 120 ° C. for 4 hours, 20 g of this dried PPS powder was added to 150 g of N-methyl-2-pyrrolidone, and vigorously stirred and mixed at room temperature for 30 minutes so as to eliminate the powder aggregate. To do. After the obtained slurry is filtered, washing is repeated 7 times using 1 liter of warm water of about 80 ° C. each time. The obtained filter cake is slurried again in 200 g of pure water, and 1N hydrochloric acid is added to adjust the pH of the slurry to 4.5. Next, after stirring at 25 ° C. for 30 minutes and filtering, washing is repeated 6 times using 1 liter of hot water at about 80 ° C. The obtained filter cake is slurried again in 200 g of pure water, then titrated with 1N sodium hydroxide, and the amount of -SX groups present in the PPS is determined from the amount of sodium hydroxide consumed.

As a specific method for producing PPS, the amount of oligomer extracted with methylene chloride is 0.001 wt% or more and 0.9 wt% or less, and the —SX group is 10 μmol / g or more and 10,000 μmol / g or less. The production methods described in Examples 1 and 2 (paragraph numbers 0041 to 0044) of JP-A-8-255357 and the production methods (paragraph numbers) described in synthesis examples 1 and 2 of JP-A-11-106656 0046 to 0048).
Further, the PPS used in the present invention has a melt viscosity at 320 ° C. (using a flow tester, 300 ° C., load 196 N, L / D (L: orifice length, D: orifice inner diameter) = 10/1 and held for 6 minutes. ) Is preferably 1 to 10,000 poise, and more preferably 100 to 10,000 poise.

  Moreover, in this invention, what introduce | transduced the acidic functional group and the reactive functional group into polyphenylene sulfide resin can be used suitably as polyphenylene sulfide resin (B). By introducing such a functional group, the miscibility between the polymer compound (A) having an ion exchange group and the polyphenylene sulfide resin (B) in the polymer electrolyte composition of the present invention is improved, and the ion exchange group is reduced. It is considered that the dispersibility of the polyphenylene sulfide resin (B) in the polymer compound (A) is improved. In particular, when an acidic functional group is introduced, the proton exchange membrane comprising the polymer electrolyte composition of the present invention means that the functional group involved in proton conductivity increases, and high proton conductivity can be expressed. preferable. Examples of acidic functional groups to be introduced include sulfonic acid groups, phosphoric acid groups, sulfonimide groups, carboxylic acid groups, maleic acid groups, maleic anhydride groups, fumaric acid groups, itaconic acid groups, acrylic acid groups, and methacrylic acid groups. Are preferred, sulfonic acid groups and phosphoric acid groups which are strongly acidic groups are more preferred, and sulfonic acid groups are most preferred. As the reactive functional group to be introduced, an epoxy group, an oxazonyl group, an amino group, an isocyanate group, a carbodiimide group and the like are preferable, and an epoxy group is particularly preferable. Further, two or more of the above various functional groups may be introduced.

The method for introducing an acidic functional group or a reactive functional group is not particularly limited, and a general method is used. For example, introduction of a sulfonic acid group can be carried out under known conditions using a sulfonating agent such as sulfuric anhydride or fuming sulfuric acid. For example, K.K. Hu, T .; Xu, W .; Yang, Y. et al. Fu, Journal of Applied Polymer Science, Vol. 91, E.E. Montoneri, Journal of Polymer Science: Part A: Polymer Chemistry, Vol. 27, 3043-3051 (1989).
Further, those in which the introduced acidic functional group is substituted with a metal salt or an amine salt are also preferably used. The metal salt is preferably an alkali metal salt such as sodium salt or potassium salt, or an alkaline earth metal salt such as calcium salt.

  The polyphenylene ether resin (hereinafter sometimes simply referred to as PPE) (C) used in the present invention is not particularly limited as long as it is a so-called polyphenylene ether resin, but a structural unit represented by the following general formula (5) is used. A phenol homopolymer or copolymer containing 70 mol% or more, preferably 90 mol% or more is preferred.

  Here, R1, R2, R3 and R4 are each hydrogen, halogen, a linear or branched lower alkyl group having 1 to 7 carbon atoms, a phenyl group, a haloalkyl group, an aminoalkyl group, a hydrocarbonoxy group, or at least The two carbon atoms are selected from the group consisting of a halohydrocarbonoxy group separating a halogen atom and an oxygen atom, and may be the same or different from each other.

  Specific examples of the PPE include poly (2,6-dimethyl-1,4-phenylene ether), poly (2-methyl-6-ethyl-1,4-phenylene ether), and poly (2-methyl). -6-phenyl-1,4-phenylene ether), poly (2,6-dichloro-1,4-phenylene ether) and the like, and 2,6-dimethylphenol and other monohydric phenols (for example, 2,3,6-trimethylphenol and 2-methyl-6-butylphenol), 2,6-dimethylphenol and divalent phenols (for example, 3,3 ′, 5,5′-tetramethylbisphenol A) A copolymer etc. are mentioned. Among these, poly (2,6-dimethyl-1,4-phenylene ether), a copolymer of 2,6-dimethylphenol and 2,3,6-trimethylphenol, 2,6-dimethylphenol and 3,3 A copolymer with ', 5,5'-tetramethylbisphenol A is preferred.

The polyphenylene ether resin (C) used in the present invention preferably has a phenolic hydroxyl group at the molecular chain end, and the position may be one end or both ends.
The reduced viscosity (0.5 g / dl, chloroform solution, measured at 30 ° C.) of the polyphenylene ether resin (C) used in the present invention is preferably in the range of 0.05 to 2.0 dl / g. More preferably, it is in the range of 0.8 dl / g.

  The production method of the polyphenylene ether resin (C) used in the present invention is not particularly limited. For example, as described in US Pat. No. 3,306,874, a complex of cuprous salt and amine is used as a catalyst. For example, it can be easily produced by oxidative polymerization of 2,6-xylenol. In addition, U.S. Pat. Nos. 3,306,875, 3,257,357, 3,257,358, JP-B-52-17880, JP-A-50-51197, and JP-A-63-152628 are disclosed. Can be easily produced by the method described in the above.

  Moreover, in this invention, what introduce | transduced the acidic functional group and the reactive functional group into polyphenylene ether resin can be used suitably as polyphenylene ether resin (C). By introducing such a functional group, the miscibility between the polymer compound (A) having an ion exchange group and the polyphenylene ether resin (C) in the polymer electrolyte composition of the present invention is improved, and the ion exchange group is reduced. It is considered that the dispersibility of the polyphenylene ether resin (C) in the polymer compound (A) is improved. In particular, when an acidic functional group is introduced, it means that the functional group involved in proton conductivity is increased in the proton exchange membrane made of the polymer electrolyte of the present invention, and it is preferable because high proton conductivity can be expressed. Examples of acidic functional groups to be introduced include sulfonic acid groups, phosphoric acid groups, sulfonimide groups, carboxylic acid groups, maleic acid groups, maleic anhydride groups, fumaric acid groups, itaconic acid groups, acrylic acid groups, and methacrylic acid groups. Are preferred, sulfonic acid groups and phosphoric acid groups which are strong acid groups are more preferred, and sulfonic acid groups are most preferred. As the reactive functional group to be introduced, an epoxy group, an oxazonyl group, an amino group, an isocyanate group, a carbodiimide group, and the like are preferable, and an epoxy group is particularly preferable. Further, two or more of the above various functional groups may be introduced.

The method for introducing an acidic functional group or a reactive functional group is not particularly limited, and can be introduced using a general method. For example, introduction of a sulfonic acid group can be carried out under known conditions using a sulfonating agent such as sulfuric anhydride or fuming sulfuric acid. For example, C.I. Wang, Y .; Huang, G .; Cong, Polymer Journal, Vol. 27, no. 2, 173-178 (1995) and J. Am. Schauer, W. et al. Albrecht, T .; Weigel, Journal of Applied Polymer Science, Vol. 73, 161-167 (1999).
Further, those in which the introduced acidic functional group is substituted with a metal salt or an amine salt are also preferably used. The metal salt is preferably an alkali metal salt such as sodium salt or potassium salt, or an alkaline earth metal salt such as calcium salt.

Next, the caged silsesquioxane or the partially cleaved structure (D) of caged silsesquioxane used in the present invention will be described.
Silsesquioxane is a compound represented by [R′SiO _3/2 ] while silica is represented by SiO ₂ . Silsesquioxane is a polysiloxane usually synthesized by hydrolysis-polycondensation of R′SiX ₃ (R ′ = hydrogen atom, organic group, siloxy group, X = halogen atom, alkoxy group) type compound. The shape of the array is typically an amorphous structure, a ladder structure, a cage-like (fully condensed cage-like) structure or a partially cleaved structure (a structure in which one silicon atom is missing from the cage-like structure or a cage-like structure) A structure in which the silicon-oxygen bond is partially broken) is known.

As an example of the specific structure of the cage-shaped silsesquioxane used for this invention, the cage-shaped silsesquioxane represented by the following general formula (a) is mentioned, for example. Examples of the specific structure of the cage-shaped silsesquioxane partial cleavage structure used in the present invention include, for example, partial cleavage of cage-shaped silsesquioxane represented by the following general formula (b): Examples include structures. However, the structure of the cage silsesquioxane or the partial cleavage structure thereof used in the present invention is not limited to these structures.
[RSiO _3/2 ] _n (A)
(RSiO _3/2 ) _l (RXSiO) _k (b)
In the general formulas (a) and (b), R is a hydrogen atom, an alkoxyl group having 1 to 6 carbon atoms, an aryloxy group, a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms, or 1 silicon atom. To 10 silicon atom-containing groups, and each R may be the same or a plurality of groups.

Examples of the cage silsesquioxane represented by the general formula (a) used in the present invention include a type represented by a chemical formula of [RSiO _3/2 ] ₆ (the following general formula (6)), [RSiO _{3 / 2} ] type represented by the chemical formula of ₈ (the following general formula (7)), [RSiO _3/2 ] a type represented by the chemical formula of ₁₀ (for example, the following general formula (8)), [RSiO _3/2 ] Examples include a type represented by a chemical formula of ₁₂ (for example, the following general formula (9)), and a type represented by a chemical formula of [RSiO _3/2 ] ₁₄ (for example, the following general formula (10)).

The value of n in the cage silsesquioxane represented by the general formula (a) [RSiO _3/2 ] _n of the present invention is an integer of 6 to 14, preferably 8, 10, or 12. More preferably, it is a mixture of 8, 10 or 8,10 or a mixture of 8, 10, 12 and particularly preferably 8 or 10.
In the present invention, a structure in which a part of the silicon-oxygen bond of the cage silsesquioxane is partially cleaved, a structure in which a part of the cage silsesquioxane is eliminated, or a derivative thereof is derived. Partial cleavage of the cage silsesquioxane represented by the general formula (b) [RSiO _3/2 ] _l (RXSiO) _k (l is an integer of 2 to 12, k is 2 or 3) Structures can also be used.

In the general formula (b), X is a group selected from OR ₁ (R ₁ is a hydrogen atom, an alkyl group, a quaternary ammonium radical), a halogen atom, and a group defined by the above R, It can be the same or different. A plurality of X in (RXSiO) _k may be connected to each other to form a connection structure. Here, l is an integer of 2 to 12, preferably an integer of 4 to 10, particularly preferably 4, 6 or 8. k is 2 or 3.
(RXSiO) 2 or 3 Xs in _k may be linked to each other X in the same molecule to form various linked structures. A specific example of the connection structure will be described below.
Two Xs in the same molecule of the general formula (b) may form an intramolecular linkage structure represented by the general formula (11). Further, two Xs present in different molecules may be connected to each other to form a multinuclear structure by the connection structure represented by the general formula (11).

Y and Z are selected from the same group of groups as X, and Y and Z may be the same or different.
Examples of the connection structure represented by the general formula (11) include the following divalent group structures.

  In the general formula (b), when two Xs in the same molecule are linked to form a linked structure, the linked structure may be a linked structure represented by the general formula (12). Q in the general formula (12) is a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms or a hydrogen atom in R in the general formula (a) and the general formula (b) (for example, Mat. Res. Soc .Sym.Prac, 1999, 576, 111).

Further, two or three Xs in the general formula (b) may be linked to form a linked structure containing a metal atom other than a silicon atom. In this case, examples of the connection structure including other metal atoms include a connection structure including a [Si—O-metal atom] type bond, or an organometallic connection structure. As a specific example of the compound of the general formula (b) having a linked structure containing other metal atoms, for example, one of Si in (RSiO _3/2 ) _n constituting the general formula (a) is Si. Instead, a structure substituted with another metal atom or an organometallic group is exemplified. Further, two Xs in the general formula (b) may be replaced with a group containing a metal atom other than a silicon atom.

  Examples of other metal atoms in these cases, or metal atoms in the organometallic connection structure include Al, Ti, Zr, V, Ta, Cr, Mo, W, Re, Ru, Pt, Sn, and Sb. , Ga, Tl and the like. Further, when these metal atoms enter, the cage silsesquioxane and / or the partially cleaved structure thereof may have a binuclear structure. (See, for example, Feher et al., Polyhedron, 1995, 14, 3239 and Organometallics, 1995, 14, 3920)

Among the above-mentioned various connecting structures in the compound represented by the general formula (b), the connecting structure represented by the general formula (11) is preferable because it is easy to synthesize.
Examples of the compound represented by the general formula (b) used in the present invention include, for example, a trisilanol body having a structure in which a part of the general formula (7) is eliminated, or synthesized from the trisilanol body (RSiO _{3 / 2} ) ₄ (RXSiO) _{3 in} the type represented by the chemical formula (for example, the following general formula (13)), the general formula (13), or (RSiO _3/2 ) ₄ (RXSiO) ₃ Of the three Xs, two Xs form a linked structure represented by the general formula (11) (for example, the following general formula (14)), from a disilanol body in which a part of the general formula (7) is cleaved The type represented by the chemical formula of (RSiO _3/2 ) ₆ (RXSiO) ₂ derived (for example, the following general formulas (15) and (16)), the general formula (15) or (RSiO _3/2 ) ₆ ( _RXSiO) of ₂ of the formula Type to form a connection structure in which two X in the compound is represented by the general formula (11) (e.g., the following general formula (17)) and the like. R and X or Y and Z bonded to the same silicon atom in the general formulas (13) to (17) may be exchanged in position. Further, two Xs present in different molecules may be connected to each other to form a multinuclear structure by various connecting structures represented by the general formula (11).

Specific examples of the compound in which two or three Xs in the general formula (b) are linked to form a linked structure containing a metal atom other than a silicon atom include, for example, the general formula (13) ), A compound represented by the chemical formula (RSiO _3/2 ) ₄ (RXSiO) ₃ (for example, the following general formula (13-Ti)) Is mentioned.
These various cage-like silsesquioxanes or their partially cleaved structures may be used alone or as a mixture thereof.

  The type of R in the compound represented by the general formula (a) and / or the general formula (b) used in the present invention is a hydrogen atom, an alkoxyl group having 1 to 6 carbon atoms, an aryloxy group, or the number of carbon atoms. Examples thereof include a substituted or unsubstituted hydrocarbon group having 1 to 20 or a silicon atom-containing group having 1 to 10 silicon atoms.

  Examples of the alkoxyl group having 1 to 6 carbon atoms include, for example, methoxy group, ethoxy group, n-propyloxy group, i-propyloxy group, n-butyloxy group, t-butyloxy group, n-hexyloxy group, Examples include a cyclohexyloxy group. Examples of the aryloxy group include a phenoxy group and a 2,6-dimethylphenoxy group. The number of alkoxyl groups and aryloxy groups in one molecule of the compound of general formula (a) or general formula (b) is preferably 3 or less, more preferably 1 or less in total.

  Examples of the hydrocarbon group having 1 to 20 carbon atoms include methyl, ethyl, n-propyl, i-propyl, butyl (n-butyl, i-butyl, t-butyl, sec-butyl), pentyl (n-pentyl). , I-pentyl, neopentyl, cyclopentyl, etc.), hexyl (n-hexyl, i-hexyl, cyclohexyl, etc.), heptyl (n-heptyl, i-heptyl, etc.), octyl (n-octyl, i-octyl, t-octyl) Etc.), nonyl (n-nonyl, i-nonyl etc.), decyl (n-decyl, i-decyl etc.), undecyl (n-undecyl, i-undecyl etc.), dodecyl (n-dodecyl, i-dodecyl etc.) Acyclic or cyclic aliphatic hydrocarbon groups such as vinyl, propenyl, butenyl, pentenyl, hexenyl, cyclohexenyl, cyclohexenyleth Acyclic and cyclic alkenyl groups such as norbornenylethyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, dodecenyl, styryl, benzyl, phenethyl, 2-methylbenzyl, 3-methylbenzyl, 4-methylbenzyl, etc. Aralkyl group, Aralkenyl group such as PhCH = CH- group, aryl group such as phenyl group, tolyl group or xylyl group, 4-aminophenyl group, 4-hydroxyphenyl group, 4-methoxyphenyl group, 4-vinyl Examples thereof include a substituted aryl group such as a phenyl group.

  Among these hydrocarbon groups, particularly when the number of aliphatic hydrocarbon groups having 2 to 20 carbon atoms and alkenyl groups having 2 to 20 carbon atoms is large enough to be all R, X, Y, and Z, it is particularly good. Melt fluidity during molding is obtained. When R is an aliphatic hydrocarbon group and / or alkenyl group, the number of carbons in R is usually 20 or less, preferably as a good balance of melt fluidity, flame retardancy and operability during molding. 16 or less, more preferably 12 or less.

  In addition, as R used in the present invention, hydrogen atoms of these various hydrocarbon groups or a part of the main skeleton are ether bonds, ester groups (bonds), hydroxyl groups, carbonyl groups, carboxylic acid anhydride bonds, thiol groups. , Thioether bonds, sulfone groups, aldehyde groups, epoxy groups, amino groups, amide groups (bonds), urea groups (bonds), isocyanate groups, cyano groups and other polar groups (polar bonds), fluorine atoms, chlorine atoms, bromine atoms It may be partially substituted with a substituent selected from halogen atoms and the like.

In general formulas (a) and (b), the total number of carbon atoms including the substituents in the substituted or unsubstituted hydrocarbon group in R is usually 20 or less. A material having a good balance of melt fluidity, flame retardancy and operability is preferably 16 or less, particularly preferably 12 or less.
As the silicon atom-containing group having 1 to 10 silicon atoms adopted as R, those having a wide range of structures are adopted, and examples thereof include groups having the following general formula (18) or general formula (19). It is done. The number of silicon atoms in the silicon atom-containing group is usually in the range of 1 to 10, preferably 1 to 6, and more preferably 1 to 3. When the number of silicon atoms becomes too large, the cage silsesquioxane compound tends to be a viscous liquid and tends to be difficult to handle and purify.

N in the general formula (18) is usually an integer in the range of 1 to 10, preferably an integer in the range of 1 to 6, more preferably an integer in the range of 1 to 3. In addition, the substituents R ₆ and R ₇ in the general formula (18) are organic atoms other than a hydrogen atom, a hydroxyl group, an alkoxy group, a chlorine atom, or an alkoxy group having 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms. It is a group.

Examples of the alkoxy group include a methoxy group, an ethoxy group, and a butoxy group.
Examples of the organic group other than the alkoxy group having 1 to 10 carbon atoms include various substituted or unsubstituted hydrocarbon groups, and specific examples thereof include, for example, a methyl group, an ethyl group, a propyl group, and a butyl group. An aliphatic hydrocarbon group such as a cyclohexyl group, an unsaturated hydrocarbon bond-containing group such as a vinyl group or a propenyl group, an aromatic hydrocarbon group such as a phenyl group, a benzyl group or a phenethyl group, or CF ₃ CH ₂ CH ₂ — And a polar group-substituted alkyl group such as an aminoalkyl group.

R ₈ in the general formula (18) is a hydrogen atom or an organic group having 1 to 20 carbon atoms, preferably 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms. Examples of the organic group include aliphatic hydrocarbons such as methyl group, ethyl group, propyl group, butyl group, pentyl group, cyclopentyl group, hexyl group, cyclohexyl group, 2-cyclohexyl-ethyl group, octyl group, and dodecyl group. Groups; groups containing unsaturated hydrocarbon bonds such as vinyl, ethynyl, allyl, 2-cyclohexenyl-ethyl; aromatic hydrocarbon groups such as phenyl, benzyl, and phenethyl; A fluorine atom-containing group such as a fluorine-containing alkyl group such as trifluoro-n-propyl group or a fluorine-containing ether group such as CF ₃ CF ₂ CF ₂ OCH ₂ CH ₂ CH ₂ ; Partially substituted carbon with polar substituents such as aminopropyl, aminoethylaminophenethyl, acryloxypropyl, cyanopropyl A hydrogen fluoride group is mentioned. In the general formula (18), two or more hydrogen atoms are not simultaneously connected to the same silicon atom.

Specific examples of the silicon atom-containing group represented by the general formula (18) include, for example, trimethylsiloxy group (Me ₃ Si—), dimethylphenylsiloxy group (Me ₂ PhSiO—), diphenylmethylsiloxy group, phenethyldimethylsiloxy. Group, dimethyl-n-hexylsiloxy group, dimethylcyclohexylsiloxy group, dimethyloctylsiloxy group, (CH ₃ ) ₃ SiO [Si (CH ₃ ) ₂ O] _k- (k = 1 to 9), 2-phenyl-2 , 4,4,4-tetramethyldisiloxy group (OSiPhMeOSiMe ₃ ), 4,4-diphenyl-2,2,4-trimethyldisiloxy (OSiMe ₂ OSiMePh ₂ ), 2,4-diphenyl-2,4,4 - trimethyl di siloxy (OSiPhMeOSiPhMe _2), vinyldimethylsiloxy , 3-glycidylpropyl dimethylsiloxy group, 3-aminopropyl dimethylsiloxy group _{(H 2 NCH 2 CH 2 CH} 2 Me 2 SiO -), H 2 NCH 2 CH 2 CH 2 Me (HO) SiO-, 3- (2 - aminoethylamino) propyl dimethylsiloxy group _{(H 2 NCH 2 CH 2 NHCH} 2 CH 2 CH 2 Me 2 SiO -), H 2 NCH 2 CH 2 NHCH 2 CH 2 CH 2 Me (HO) SiO- , and the like .

In General formula (19), Ra is a C1-C10 bivalent hydrocarbon group, As carbon number, Preferably it is the range of 2-6, Most preferably, it is 2 or 3. Specific examples of Ra include alkylene groups such as —CH ₂ CH ₂ —, —CH ₂ CH ₂ CH ₂ —, and — (CH ₂ ) _m — (m = 4 to 10).
Definition of _{R 6,} R 7, _{R 8} in the general formula (19) is the same as _{R 6,} R 7, _{R 8} in the general formula (13), respectively. The definitions of R ₉ and R ₁₀ are the same as R ₆ and R ₇ . n ′ is 0 or an integer in the range of 1 to 9, preferably 0 or an integer in the range of 1 to 5, particularly preferably 0, 1 or 2.

In the present invention, a wide range of caged silsesquioxanes represented by the general formula (a) and / or the general formula (b) and / or partially cleaved structures thereof are used. In general formula (a) and general formula (b), a plurality of R, X, Y and Z in one molecule may be the same or different.
The present inventors have already shown that the melt fluidity of the resin composition is remarkably improved by mixing the specific cage silsesquioxane and the partially cleaved structure thereof with the polyphenylene ether resin (C). (WO2002 / 059208).

  A polymer electrolyte composition containing a polymer compound (A) having an ion exchange group, a polyphenylene sulfide resin (B), and a polyphenylene ether resin (C) has a cage silsesquioxane and a partially cleaved structure (D) thereof. By containing, the melt fluidity of the polyphenylene ether resin in the polymer electrolyte composition is improved and the particle dispersibility is improved. As a result, the polymer electrolyte composition and the proton exchange membrane made of this composition are further durable. Improvement is realized.

  In the present invention, the polyphenylene ether resin (C) is mixed with the cage silsesquioxane and its partially cleaved structure (D) in advance, and then the polymer compound (A) having an ion exchange group and the polyphenylene sulfide are mixed. The composition of the present invention is preferably added to and mixed with the resin (B). Of course, the polymer compound (A) having an ion exchange group, the polyphenylene sulfide resin (B), the polyphenylene ether resin (C), the cage silsesquioxane and the partial cleavage structure (D) thereof are mixed at the same time, or any The same effect can be obtained by sequentially mixing in order as the composition of the present invention.

The cage silsesquioxanes of the present invention are described, for example, in Brown et al. Am. Chem. Soc. 1965, 87, 4313, and Feher et al. Am. Chem. Soc. 1989, 111, 1741 or Organometallics 1991, 10, 2526. For example, it can be obtained as crystals by reacting cyclohexyltriethoxysilane in water / methyl isobutyl ketone with addition of tetramethylammonium hydroxide as a catalyst. Further, the trisilanol body and the disilanol body represented by the general formula (13) (X = OH), the general formula (15) (X = OH), and the general formula (16) (X = OH) are in a completely condensed cage shape. It can be synthesized simultaneously with the production of silsesquioxane, or can be synthesized by partially cleaving once from a fully condensed cage silsesquioxane with trifluoroacid or tetraethylammonium hydroxide (Feher et al., Chem. Commun. , 1998, 1279). Furthermore, the compound of the general formula (13) (X = OH) can also be directly synthesized from the RSiT ₃ (T = Cl or alkoxyl group) type compound.

Among the eight Rs in the general formula (7), a method of introducing a substituent R ′ that differs only by one R is a trisilanol compound represented by the general formula (13) (X═OH) and R ′. Examples include a method of reacting SiCl ₃ , R′Si (OMe) ₃ , R′Si (OEt) _{3 and the} like to synthesize. As a specific example of such a synthesis method, for example, a partially cleaved silsesquioxane structure represented by the general formula (13) (R = cyclohexyl group, X = OH) is synthesized by the above method. In a tetrahydrofuran solution, 3 equivalents of triethylamine were added to a mixture of 1 equivalent of HSiCl _{3 and} 1 equivalent of a partially cleaved structure of caged silsesquioxane represented by the general formula (13) (R = cyclohexyl, X═OH). (See, for example, Brown et al., J. Am. Chem. Soc. 1965, 87, 4313).

Specific examples of the method for introducing a silicon atom-containing group as X in the partially cleaved silsesquioxane structure represented by the general formula (B) include, for example, the general formula (13) (R = cyclohexyl group, X Me ₃ SiO— group is introduced as X by adding 3 equivalents of triethylamine and 3 equivalents of trimethylchlorosilane in tetrahydrofuran to 1 equivalent of a partially cleaved silsesquioxane structure represented by = OH) (For example, refer to J. Am. Chem. Soc. 1989, 111, 1741).

The structural analysis of the cage silsesquioxane of the present invention can be performed by X-ray structural analysis (Larson et al., Alkiv Kemi 16,209 (1960)), but simply using an infrared absorption spectrum or NMR. (See, for example, Vogt et al., Inorga. Chem. 2, 189 (1963)).
The cage silsesquioxane or the partially cleaved structure of cage silsesquioxane used in the present invention may be used alone or as a mixture of two or more. Further, a cage-shaped silsesquioxane and a partially-cleavage structure of cage-shaped silsesquioxane may be mixed and used.

  Moreover, you may use the cage | basket silsesquioxane used for this invention, the partial cleavage structure of cage | basket silsesquioxane, or its mixture in combination with the organosilicon compound of another structure. Examples of organosilicon compounds having other structures in this case include, for example, polydimethyl silicone, polydimethyl / methylphenyl silicone, substituted silicone compounds containing polar substituents such as amino groups and hydroxyl groups, and amorphous polymethylsil Examples thereof include sesquioxane and various ladder-type silsesquioxanes. In that case, the composition ratio of the mixture is not particularly limited, but usually the ratio of the cage silsesquioxane or / and the partially cleaved structure in the mixture is preferably 10% by weight or more, and more preferably It is used at 30% by weight or more, particularly preferably at 50% by weight or more.

  Instead of the cage silsesquioxane represented by the general formulas (a), (b) and (6) to (17) used in the present invention, or a partially cleaved structure of cage silsesquioxane, When an amorphous polysilsesquioxane that does not form a polymer is used as an additive for a polyphenylene ether-based resin composition, the effects of improving melt fluidity and flame retardancy are small.

  The polymer electrolyte composition of the present invention includes the above-described polymer compound (A) having an ion exchange group, polyphenylene sulfide resin (B), polyphenylene ether resin (C), and cage silsesquioxane or cage silsesquioxane. It is a composition which consists of a partial cleavage structure (D) of oxane. Such a polyelectrolyte composition of the present invention and a proton exchange membrane comprising the composition include a polyphenylene sulfide resin (B), a polyphenylene ether, as compared with the polymer compound (A) having an ion exchange group alone. Compared to the case where the resin (C), the cage silsesquioxane or the partially cleaved structure (D) of the cage silsesquioxane is contained in the polymer compound (A) having an ion exchange group, respectively. However, its durability is remarkably improved. Surprisingly, the polymer electrolyte composition of the present invention contains many resins including the resin used in the present invention in the polymer compound (A) having an ion exchange group in various combinations other than the present invention. The durability is remarkably improved as compared with the case of making them.

Next, the polymer compound (A) having an ion exchange group, polyphenylene sulfide resin (B), polyphenylene ether resin (C), cage silsesquioxane or cage silsesquioxane in the polymer electrolyte composition of the present invention. The composition ratio of the partial cleavage structure (D) of oxane will be described.
In the polymer electrolyte composition of the present invention, the weight ratio of the polyphenylene sulfide resin (B) to the polyphenylene ether resin (C) is preferably B / C = 1/99 to 99/1. More preferably, the weight ratio is B / C = 20/80 to 95/5, and most preferably B / C = 30/70 to 90/10.

  Moreover, the weight ratio ((B + C) / A) of the polyphenylene sulfide resin (B), the polyphenylene ether resin (C) and the polymer compound (A) having an ion exchange group is 99/1 to 0.01 / 99.99. It is preferable that From the balance between proton conductivity and durability, (B + C) / A is more preferably 90/10 to 0.05 / 99.95, further preferably 70/30 to 0.1 / 99.9, and 50/50 to 1/99 is particularly preferable, and 30/70 to 5/95 is most preferable.

  The weight ratio (C / D) of the polyphenylene ether resin (C) to the cage silsesquioxane or the partially cleaved structure (D) of cage silsesquioxane is 99.9 / 0.1 to 10 / 90 is preferable. The weight ratio is more preferably 99.9 / 0.1 to 50/50, further preferably 99.5 / 0.5 to 70/30, and particularly preferably 99/1 to 85/15. When the weight ratio of the cage silsesquioxane or the partially cleaved structure (D) of the cage silsesquioxane is less than the above range, the effect of improving the melt fluidity tends to be small, and when the weight ratio is more than the above range Is not preferred because the physical properties such as mechanical strength tend to decrease.

  The polymer electrolyte composition of the present invention preferably further contains an epoxy group-containing compound (E). Contains a polymer compound (A) having an ion exchange group, a polyphenylene sulfide resin (B), a polyphenylene ether resin (C) and a cage silsesquioxane or a partially cleaved structure (D) of cage silsesquioxane. When the polymer electrolyte composition contains the epoxy group-containing compound (E), the particle dispersibility in the polymer electrolyte composition is improved. As a result, the polymer electrolyte composition and proton exchange comprising the composition are exchanged. A further improvement in the durability of the membrane is realized.

  The epoxy group-containing compound (E) used in the present invention is not particularly limited as long as it is a compound having an epoxy group. For example, a low molecular compound containing an epoxy group, a homopolymer of an unsaturated monomer having an epoxy group, or A copolymer (F), an epoxy resin (G), etc. are mentioned. Since the polymer compound is easier to handle at high temperature, a homopolymer or copolymer (F) of an unsaturated monomer having an epoxy group and an epoxy resin (G) are preferred.

  The low molecular weight compound containing an epoxy group is preferably a solid or liquid at 200 ° C., specifically, 1,2-epoxy-3-phenoxypropane, N- (2,3-epoxypropyl). ) Phthalimide, 3,4-epoxytetrahydrothiophene-1,1-dioxide, glycidyl 4-nonylphenyl ether, glycidyl tosylate, glycidyl trityl ether, and the like.

  The unsaturated monomer having an epoxy group constituting the homopolymer or copolymer (F) of the unsaturated monomer having an epoxy group used in the present invention is not limited as long as it is an unsaturated monomer having an epoxy group. Examples thereof include glycidyl methacrylate, glycidyl acrylate, vinyl glycidyl ether, glycidyl ether of hydroxyalkyl (meth) acrylate, glycidyl ether of polyalkylene glycol (meth) acrylate, glycidyl itaconate and the like. Among these, glycidyl methacrylate is preferable.

  In the case of a copolymer of an unsaturated monomer having an epoxy group, other unsaturated monomers copolymerized with the unsaturated monomer having an epoxy group include vinyl aromatic compounds such as styrene, vinyl cyanide monomers such as acrylonitrile, Vinyl acetate, (meth) acrylic acid ester and the like are preferable. Examples of copolymers obtained by copolymerizing these copolymerizable unsaturated monomers include, for example, styrene-glycidyl methacrylate copolymer, styrene-glycidyl methacrylate-methyl methacrylate copolymer, styrene-glycidyl methacrylate-acrylonitrile copolymer. A polymer etc. are mentioned.

  The epoxy resin (G) used in the present invention is, for example, a cresol novolac type epoxy resin, a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a bisphenol S type epoxy resin, a hindered-in type epoxy resin, a biphenyl type epoxy resin, or an alicyclic ring. And epoxy epoxy resin, triphenylmethane type epoxy resin and phenol novolac type epoxy resin. One or more selected from these may be used in combination. Among them, cresol novolac type epoxy resins and bisphenol A type epoxy resins are preferable, and cresol novolac type epoxy resins are particularly preferable.

In the present invention, the polyphenylene ether resin (C) and the epoxy resin (G) can be added by mixing and reacting in advance. That is, an epoxy-modified polyphenylene ether resin (H) obtained by reacting a polyphenylene ether resin and an epoxy resin can be used as the polyphenylene ether resin (C). Of course, after the polyphenylene ether resin (C) and the epoxy resin (G) are mixed together with the components (A) and (B) to obtain the composition of the present invention, the polyphenylene ether resin (C) is used under the conditions described later. And the epoxy resin (G) may be reacted.
By using the epoxy-modified polyphenylene ether resin (H) as the polyphenylene ether resin (C), the dispersibility of the obtained polymer electrolyte composition is improved, and as a result, the polymer electrolyte composition and protons comprising this composition are improved. The durability of the exchange membrane is further improved.

In the method for producing the epoxy-modified polyphenylene ether resin (H), the reaction temperature is preferably 100 to 250 ° C. More preferably, it is 120-195 degreeC, More preferably, it is the range of 140-190 degreeC. The reaction time is preferably less than 3 hours, more preferably within 2 hours, particularly preferably within 40 minutes.
The reactor used for the production of the epoxy-modified polyphenylene ether resin (H) is preferably one that can uniformly mix, stir or knead the polyphenylene ether resin and the epoxy resin. If the viscosity is high, a kneader such as a twin screw extruder or kneader Can be used. The manufacturing method can use any process form of a continuous reaction process, a batch reaction process, and a semi-batch reaction process.

  In the method for producing the epoxy-modified polyphenylene ether resin (H), a basic compound can be added to the reaction system from the viewpoint of improving the reaction rate, suppressing side reactions, and controlling the structure of the reaction composition. Specific examples of basic compounds include lithium, sodium, potassium, sodium methylate, sodium ethylate, tertiary amines such as triethylamine and tributylamine, imidazole, sodium phenoxide, lithium hydroxide, sodium hydroxide, potassium hydroxide, Examples include potassium carbonate and sodium carbonate. Among these, sodium methylate, triethylamine, tributylamine, sodium hydroxide and the like are preferable. In addition to the above basic compounds, quaternary ammonium salts can also be used as catalysts.

  In the present invention, each of the components (A) to (H) may be composed of two or more kinds of compounds. For example, the polyphenylene sulfide resin (B) includes an example using a mixture of polyphenylene sulfide and sulfonated polyphenylene sulfide. Also, as polyphenylene ether resin (C), polyphenylene ether resin (C), poly (2,6-dimethyl-1,4-phenylene ether) and poly (2-methyl-6-ethyl-1,4-phenylene ether) ) Or a mixture of poly (2,6-dimethyl-1,4-phenylene ether) and poly (2,6-dimethyl-1,4-phenylene ether) into which a sulfonic acid group is introduced is used. Examples are given.

  About the polymer electrolyte composition of this invention, various additives, such as antioxidant, antioxidant, a heavy metal deactivator, a flame retardant, can be added as needed. The weight ratio of the polymer electrolyte composition of the present invention to the additive (electrolyte composition / additive) is preferably 80/20 to 99.999 / 0.001, more preferably 90/10 to 99.99. 99 / 0.01, more preferably 95/5 to 99.9 / 0.1.

  Next, a method for producing the polymer electrolyte composition of the present invention will be described. The polymer electrolyte composition of the present invention is obtained by mixing the components selected from the aforementioned components (A) to (H), but the method is not particularly limited, and a general polymer composition The mixing method of the product can be suitably applied.

  For example, a polymer compound (A) having an ion exchange group or a precursor polymer thereof, and components selected from the components (B) to (H) are thermally melted, and a kneading extruder, a lab plast mill, a kneading roll, The method of kneading with a Banbury mixer etc. is mentioned. In addition, the components selected from the components (B) to (H) are heat-melted in advance and kneaded with a kneading extruder, a lab plast mill, a kneading roll, a Banbury mixer or the like to obtain a mixture. The polymer compound (A) having an exchange group or a precursor polymer thereof can be similarly kneaded to obtain a final polymer electrolyte composition. The combination and order of kneading can be performed arbitrarily. In addition, when the precursor polymer is used in place of the polymer compound (A) having an ion exchange group, it is converted into a form having an ion exchange group by performing an alkali hydrolysis treatment and an acid treatment after kneading. The polymer electrolyte composition of the invention can be obtained.

  The kneading method at this time is achieved by a conventionally known technique such as a Brabender, a kneader, a Banbury mixer, and an extruder. In particular, it is preferable to use an extruder because the obtained polymer electrolyte composition can easily finely disperse other components in the polymer compound (A) having an ion exchange group.

  As a most preferred embodiment as a method for industrially easily obtaining the polymer electrolyte composition used in the present invention, an extruder for melting and kneading each of the above-mentioned components has a kneading block at an arbitrary position of a screw. It is a multi-screw extruder having two or more screws that can be incorporated, and the entire kneading block portion of the screw used is substantially (L / D) ≧ 1.5, more preferably (L / D) ≧ 5 (here L is the total length of the kneading block, D is the maximum outside diameter of the kneading block), and (π · D · N / h) ≧ 50 (where π = 3.14, D = screw outer diameter corresponding to the metering zone, N = screw rotation speed (rotation / second), h = groove depth of the metering zone]. These extruders have a first raw material supply port on the upstream side with respect to the flow direction of the raw material, a second raw material supply port on the downstream side, and if necessary, one more downstream on the downstream side of the second raw material supply port. The above raw material supply ports may be provided, and a vacuum vent port may be provided between these raw material supply ports as necessary.

  In addition, a method of removing the solvent after preparing a solution by mixing a solution of the polymer compound (A) having an ion exchange group or a precursor polymer thereof with each solution of the components (B) to (H) is also mentioned. It is done. Also in this case, when the precursor polymer solution was used in place of the polymer compound (A) solution having an ion exchange group, the solvent was removed, and then ion exchange was performed by alkali hydrolysis treatment and acid treatment. The polymer electrolyte composition of the present invention can be obtained by converting to a form having a group.

  The polymer electrolyte composition of the present invention can be obtained by the method as described above. In the present invention, at least a structure in which other components are finely dispersed in the polymer compound (A) having an ion exchange group is used. By having it, the effects of the present invention such as a longer life can be obtained. That is, in the polymer compound (A) having an ion exchange group, the particles composed of other components have a circular average particle diameter of 0.0001 μm to 1 μm, preferably 0.0001 μm to 0.8 μm, more preferably It is preferable to have a structure in which it is dispersed in a range of 0.0001 μm to 0.5 μm, particularly preferably 0.0001 μm to 0.3 μm. It is not always necessary to satisfy the above range in all regions of the composition, as long as 50 to 100% of the entire region of the composition satisfies the above range.

Moreover, you may have a structure where (A) component has penetrated the inside of the dispersion particle which consists of another component. However, also at this time, the particle diameter of the dispersed particles is 0.0001 μm or more and 1 μm or less, preferably 0.0001 μm or more and 0.8 μm or less, more preferably 0.0001 μm or more and 0.5 μm or less, particularly preferably in terms of a circle-converted average particle diameter The thickness is preferably 0.0001 μm or more and 0.3 μm or less from the viewpoint of extending the life.
And it is suitable to have at least the fine dispersion structure as described above even in the proton exchange membrane described later.

  Such a finely dispersed structure can be controlled by the composition of the material, various conditions during processing, and the like. More specifically, the composition of the material includes the combination and amount ratio of each component, the use of a compatibilizing agent, and the type of solvent when using the solvent. Various conditions during processing include temperature conditions and stirring / kneading conditions, and the influence of screw design and screw rotation speed is particularly large during extrusion processing.

  In addition, the circle conversion average particle diameter in this invention is defined as follows. A thin slice is prepared from the polymer electrolyte composition or proton exchange membrane of the present invention, dyed with a dye such as ruthenium tetroxide by a conventional method, observed with a transmission electron microscope, and the average particle diameter of the dyed phase And take this value as the particle size. The average particle diameter at this time is the circle-converted diameter (the same area for each particle) calculated from this, after reading an arbitrary 20 × 20 μm field of view of a thin slice directly or after printing it on a photo from a negative, and reading it into an image analyzer. Number average value). However, if the staining boundary is unclear when inputting from the photograph to the image analysis apparatus, the photograph is traced and input to the image analysis apparatus using this figure.

  Next, a method for producing a proton exchange membrane made of the polymer electrolyte composition of the present invention will be described. The polymer electrolyte composition of the present invention can be formed into a membrane and used as a proton exchange membrane. The film forming means is not particularly limited, and a general polymer composition film forming method can be suitably applied. For example, known film forming methods such as calendar molding, press molding, T-die molding, and inflation molding can be used. Among these, T-die molding and inflation molding are preferable as methods for easily industrially obtaining a proton exchange membrane from the polymer electrolyte composition of the present invention. Inflation molding is particularly preferable from the viewpoint of obtaining a film having small anisotropy.

  Further, a polymer composition comprising a precursor of the polymer electrolyte composition of the present invention, for example, a precursor polymer of a polymer compound (A) having an ion exchange group, and a component selected from the components (B) to (H). After the product is formed using the above-described film forming method, the polymer electrolyte of the present invention is converted into a form having an ion exchange group by performing an appropriate post-treatment such as alkali hydrolysis treatment or acid treatment. A proton exchange membrane comprising the composition can also be obtained.

  Alternatively, the proton exchange membrane can be obtained by mixing each solution of the components (A) to (H) to prepare a solution, casting the solution, and then removing the solvent. As a casting method, a known coating method such as a method of casting into a petri dish, a gravure roll coater, a natural roll coater, a reverse roll coater, a knife coater and a dip coater can be used. The base material used for the casting method is a general polymer film, a metal foil, a substrate made of alumina, silicon or the like, a porous film obtained by stretching a PTFE film described in JP-A-8-162132, and JP-A-53- The fibrillated fibers disclosed in Japanese Patent No. 149881 and Japanese Patent Publication No. 63-61337 can be used. As a method for removing the solvent, methods such as heat treatment at room temperature to 200 ° C. and reduced pressure treatment can be used. When heat treatment is performed, the solvent can be removed by raising the temperature stepwise.

  Further, for example, instead of the solution of the polymer compound (A) having an ion exchange group, the solution of the precursor polymer is used, and the solutions of the components (B) to (H) are mixed to prepare a solution. After casting the solution, the solvent is removed, and then subjected to an appropriate post-treatment such as alkaline hydrolysis treatment or acid treatment to convert it into a form having an ion-exchange group, whereby the polymer electrolyte composition of the present invention is used. A proton exchange membrane can be obtained.

  In the production of the proton exchange membrane of the present invention, stretch orientation can be imparted by carrying out transverse uniaxial stretching, simultaneous biaxial stretching or sequential biaxial stretching in combination with the above-described production method. Such stretching treatment is preferable because the mechanical properties of the proton exchange membrane of the present invention can be improved. This stretching treatment can be carried out in the state of a proton exchange membrane, or can be carried out in a state in which the proton exchange group is replaced with a metal salt such as sodium salt, potassium salt and calcium salt, ammonium salt or the like. When a polymer composition comprising a precursor polymer of the polymer compound (A) having an ion exchange group and a component selected from the components (B) to (H) is formed, the state immediately after the film formation However, it can also be carried out, and it can be carried out after the membrane is converted into a form having an ion exchange group by performing an appropriate post-treatment such as alkali hydrolysis treatment or acid treatment.

  The stretching treatment is preferably carried out at a magnification of 1.1 to 6.0 in the transverse (TD) direction and 1.0 to 6.0 in the longitudinal (MD) direction, more preferably 1. 1 to 3.0 times, 1.0 to 3.0 times in the vertical direction, more preferably 1.1 to 2.0 times in the horizontal direction, and 1.0 to 2.0 times in the vertical direction. The area stretch ratio is preferably 1.1 to 36 times.

  The proton exchange membrane of the present invention can have a structure in which at least two types of proton exchange membranes having different composition ratios are laminated. In the proton exchange membrane comprising the polymer electrolyte composition of the present invention, the higher the content of the resin other than the polymer compound (A) having an ion exchange group, the better the mechanical strength and the wet / dry dimensional change, and the higher the content of the ion exchange group. The higher the molecular compound (A) content, the better the electrical properties such as proton conductivity. By utilizing these characteristics, two or more types of proton exchange membranes with different composition ratios are designed and combined to form a single layer of a proton exchange membrane that excels in mechanical strength, wet and dry dimensional changes, and electrical properties. This can be realized more easily than in the case of a layer film.

  Although the number of layers to be laminated is not limited, since the manufacturing cost increases as the number of layers increases, about 2 to 10 layers are preferable. More preferably, it is 2-7 layers, and 3-5 layers are especially preferable. A polymer compound (A) having an ion exchange group, a polyphenylene sulfide resin (B), a polyphenylene ether resin (C), a cage silsesquioxane or a cage silsesquioxane partial cleavage structure (D) of each layer The composition ratio can be arbitrarily changed within the above-mentioned range. Further, the thickness of each layer can be arbitrarily changed in consideration of characteristics.

  For example, in the case of a multilayer structure of three or more layers, the content ratio of the polymer compound (A) having an ion exchange group in the inner layer is made smaller than that of at least one of the surface layers, and the wet and dry dimensional changes in the inner layer When the thickness is suppressed, the thickness of the inner layer is preferably 5 to 90% of the total thickness, more preferably 7 to 80%, and particularly preferably 10 to 50%. In addition, when the content of the polymer compound (A) having an ion exchange group in the surface layer is made smaller than that in the inner layer and the change in the wet and dry dimensions is suppressed in the surface layer, the total thickness of the surface layer is A 5 to 50% ratio of the thickness is preferable, a 7 to 45% ratio is more preferable, and a 10 to 40% ratio is particularly preferable.

In the production of the proton exchange membrane of the present invention, in addition to the above-described production method, reinforcement by adding a reinforcing material made of an inorganic material, an organic material, or an organic-inorganic hybrid material, reinforcement by crosslinking, and the like can be performed. The reinforcing material may be a short fiber material, a particulate material, or a flaky material. Further, a continuous support such as a porous film, a mesh, and a nonwoven fabric may be used. By carrying out the reinforcement by adding a reinforcing material to the proton exchange membrane of the present invention, the mechanical strength and the change in wet and dry dimensions can be easily improved. In particular, when a short fiber substance or the above-mentioned continuous support is used as a reinforcing material, the reinforcing effect is high.
The reinforcing material may be added and mixed at the same time during melt-kneading, or may be laminated with the film after film formation.

  The inorganic material used as the reinforcing material is not particularly limited as long as it has a reinforcing effect. For example, glass fiber, carbon fiber, cellulose fiber, kaolin clay, kaolinite, halloysite, pyrophyllite, talc, montmorillonite, sericite, mica Americite, bentonite, asbestos, zeolite, calcium carbonate, calcium silicate, diatomaceous earth, silica sand, iron ferrite, aluminum hydroxide, aluminum oxide, magnesium oxide, titanium oxide, zirconium oxide, manganese oxide, graphite, fullerene, Examples include carbon nanotubes and carbon nanohorns. The organic material used as the reinforcing material is not particularly limited as long as it has a reinforcing effect. For example, polyphenylene sulfide, polyphenylene ether, polysulfone, polyether sulfone, polyether ether sulfone, polyether ketone, polyether ether ketone, polythioether. Sulfone, polythioether ether sulfone, polythioether ketone, polythioether ether ketone, polybenzimidazole, polybenzoxazole, polyoxadiazole, polybenzoxazinone, polyxylylene, polyphenylene, polythiophene, polypyrrole, polyaniline, polyacene, polycyanogen, polynaphthyridine , Polyphenylene sulfide sulfone, polyphenylene sulfone, polyimide, polyetherimide, poly Esterimide, polyamideimide, polyamide, aromatic polyamide, polystyrene, acrylonitrile-styrene resin, polystyrene-hydrogenated polybutadiene-polystyrene block copolymer, acrylonitrile-butadiene-styrene resin, polyester, polyarylate, liquid crystal polyester, polycarbonate, Examples thereof include polytetrafluoroethylene, polyvinylidene fluoride, polyvinyl chloride, polyvinylidene chloride, methacrylic resin, epoxy resin, phenol resin, melamine resin, urethane resin, cellulose, polyketone, polyacetal, polypropylene, and polyethylene. An organic-inorganic hybrid material can also be used as a reinforcing material, and examples thereof include an organic silicon polymer compound having a silsesquioxane structure or a siloxane structure such as POSS (Polyhedral Oligomeric Silsesquioxanes) or silicone rubber.

Moreover, about the polymer electrolyte composition of this invention, a mechanical physical property can also be improved by heat-processing in 160 degreeC or more, for example in air or oxygen atmosphere.
The equivalent weight EW of the proton exchange membrane produced according to the present invention (dry weight gram of proton exchange membrane per equivalent of proton exchange group) is preferably 250 or more and 2000 or less, more preferably 400 or more and 1500 or less, most preferably. Is 500 or more and 1200 or less. By using a proton conductive polymer with a lower EW, that is, a large proton exchange capacity, it exhibits excellent proton conductivity even under high temperature and low humidity conditions, and when used in a fuel cell, a high output can be obtained during operation. .

The thickness of the proton exchange membrane produced according to the present invention is preferably 1 μm or more and 500 μm or less, more preferably 2 μm or more and 100 μm or less, and most preferably 5 μm or more and 50 μm or less.
The change in wet and dry dimensions of the proton exchange membrane produced according to the present invention is preferably 0% to 100%, more preferably 0% to 50%, and most preferably 0% to 10%. The term “wet and dry dimensional change” as used herein refers to the ratio of the change in dimension when left in water at 80 ° C. for 1 hour with respect to the dimension when left at 25 ° C. and 20 RH% for 1 hour. The dimension is the length in the vertical direction or the horizontal direction of the proton exchange membrane, and both preferably satisfy the above range.

A fuel cell was assembled as follows using the proton exchange membrane of the present invention, and durability was evaluated.
(Membrane electrode assembly)
When the proton exchange membrane obtained by the present invention is used in a polymer electrolyte fuel cell, it is used as a membrane electrode assembly (hereinafter abbreviated as “MEA”) in which two types of electrode catalyst layers are joined to an anode and a cathode. A structure in which a pair of gas diffusion layers are bonded to the outer side of the electrode catalyst layer so as to face each other is also called MEA.
The electrode catalyst layer is composed of fine particles of a catalytic metal and a conductive agent supporting the catalyst metal, and a water repellent is included as necessary. The catalyst used for the electrode may be any metal that promotes the oxidation reaction of hydrogen and the reduction reaction by oxygen. Platinum, gold, silver, palladium, iridium, rhodium, ruthenium, iron, cobalt, nickel, chromium, tungsten , Manganese, vanadium, alloys thereof, etc., among which platinum is mainly used.

  As the MEA manufacturing method, for example, the following method is performed. First, a platinum-supported carbon serving as an electrode material is dispersed in a solution obtained by dissolving an ion exchange resin in a mixed solution of alcohol and water to form a paste. A certain amount of this is applied to a PTFE sheet and dried. Next, the application surface of the PTFE sheet faces each other, the proton exchange membrane of the present invention is sandwiched therebetween, and transfer bonding is performed by hot pressing at 100 ° C. to 200 ° C. to obtain an MEA.

(Fuel cell)
The MEA obtained above and, in some cases, a structure in which a pair of gas diffusion electrodes are opposed to each other via the MEA are further combined with components used for general solid polymer fuel cells such as bipolar plates and backing plates. Thus, a polymer electrolyte fuel cell is constructed.
Bipolar plates are graphite or resin composite materials, metal plates, etc. that have grooves on the surface for the flow of gas such as fuel and oxidant, and are used to transmit electrons to an external load circuit. In addition, it has a function as a flow path for supplying fuel and oxidant to the vicinity of the electrode catalyst. A fuel cell is manufactured by inserting and stacking a plurality of MEAs between such bipolar plates.
The method for evaluating the durability of the proton exchange membrane obtained from the solution for producing the fuel cell of the present invention has been described above.

Hereinafter, the present invention will be specifically described by way of examples.
The evaluation method and measurement method used in the present invention are as follows.
(Proton conductivity measurement)
A membrane sample is cut out in a wet state and the thickness T is measured. This is mounted on a two-terminal conductivity measuring cell that measures the conductivity in the film length direction having a width of 1 cm and a length of 5 cm. This cell is placed in ion exchange water at 80 ° C., and the resistance value R of the real component at a frequency of 10 kHz is measured by the AC impedance method, and the proton conductivity σ is derived from the following equation.
σ = L / (R × T × W)
σ: proton conductivity (S / cm)
T: Thickness (cm)
R: Resistance value (Ω)
L (= 5): film length (cm)
W (= 1): film width (cm)

(Fuel cell evaluation)
(1) Manufacture of fuel cell First, a proton exchange membrane is sandwiched between two gas diffusion electrodes coated on a mount and hot pressed at 180 ° C. and a pressure of 10 MPa to transfer and bond the gas diffusion electrode to the proton exchange membrane. To produce an MEA.
As a gas diffusion electrode, a platinum-supported catalyst TEC10E40E (trade name, platinum support ratio 40% by weight) manufactured by Tanaka Kikinzoku Kogyo Co., Ltd., and a perfluorosulfonic acid polymer solution SS-700x / 05 (trade name, manufactured by Asahi Kasei Co., Ltd.) , EW: 720, solvent composition (weight ratio): ethanol / water = 50/50) and a solution concentrated to 12% by weight and ethanol were added, mixed and stirred to form an ink on a PTFE sheet. After that, dry and fixed at 150 ° C. in an air atmosphere. This gas diffusion electrode has a platinum loading of 0.4 mg / cm ² and a polymer loading of 0.5 mg / cm ² .

  Carbon paper or carbon cloth subjected to water repellent treatment is disposed on both sides of the MEA, and is incorporated into an evaluation cell and set in an evaluation apparatus. A single cell characteristic test is performed using hydrogen gas as a fuel and air gas as an oxidizing agent at a cell temperature of 100 ° C. and 0.1 MPa. A water bubbling method is used for gas humidification, and both hydrogen gas and air gas are humidified at 50 ° C. and supplied to the cell.

(2) Measurement of fluorine elution rate The waste water discharged together with the anode exhaust gas and the cathode exhaust gas during the single cell characteristic test is respectively collected for a predetermined time, and then weighed. The fluorine composite electrode 9609BNionplus (trade name) is attached to a bench top type pH ion meter 920Aplus (trade name) manufactured by Meditrial Co., Ltd., and the fluorine ion concentration in the anode drainage and the cathode drainage is measured. The elution rate G is derived.
G = (Wa × Fa + Wc × Fc) / (T × A)
G: Fluorine elution rate (μg / Hr / cm ² )
Wa: Weight of anode wastewater collected and collected (g)
Fa: Fluorine ion concentration (ppm) in anode drainage
Wc: Weight of cathode drainage collected and collected (g)
Fc: Fluorine ion concentration in the cathode drainage (ppm)
T: Time for collecting and collecting wastewater (Hr)
A: MEA electrode area (cm ² )

(3) Measurement of cross leak amount Part of cathode exhaust gas during single cell characteristic test is introduced into GL Sciences' micro gas chromatograph Micro GC CP-4900 (trade name), and hydrogen gas concentration in cathode exhaust gas is measured. The hydrogen gas permeability is derived from the following equation.
L = (X × V × T) × (5-U / 100) / (3 × A × P) × 10 ⁻⁸
L: Hydrogen gas permeability (ml × cm / cm ² / sec / Pa)
X: Hydrogen gas concentration (ppm) in cathode exhaust gas
V: Cathode gas flow rate (ml / min)
T: thickness of proton exchange membrane (cm)
U: Cathode gas utilization rate (%)
A: Hydrogen permeation area of the proton exchange membrane (cm ² )
P: Hydrogen partial pressure difference between the cathode and anode (Pa)
The time when the hydrogen gas permeability during the short cell characteristic test became 1.1 × 10 ⁻¹¹ (ml × cm / cm ² / sec / Pa) or more was defined as the cell life, and the test was terminated there.

(4) Measurement of tensile elastic modulus A proton exchange membrane cut into a width of 5 mm and a length of 40 to 50 mm is used as a sample. After immersing this in 80 ° C. water for 30 minutes or more, the sample is quickly set in a tensile tester with an 80 ° C. constant temperature water bath (Shimadzu Corporation: trade name, AGS-1kNG) so that the distance between chucks is 20 mm. A tensile test is performed at a tensile rate of 10% / second 3 minutes after the sample is immersed in a constant temperature water bath, and the tensile elastic modulus (N / cm ² ) is determined from the tensile strength at the time of 5% elongation.

[Example 1]
90 parts by weight of a precursor polymer (MI: 3.0, Ew after alkali hydrolysis and acid treatment: 730) obtained from tetrafluoroethylene and CF ₂ ═CFO (CF ₂ ) ₂ —SO ₂ F, and polyphenylene Sulfide (melt viscosity (measured using a flow tester at 300 ° C., load 196 N / cm ² , L / D (L: orifice length, D: orifice inner diameter) = 10/1 after holding for 6 minutes)). 50 Pa · s, 7 parts by weight extracted with methylene chloride, 0.7 parts by weight, -SX group amount 25 μmol / g) and polyphenylene ether (2,6-xylenol obtained by oxidative polymerization, reduced viscosity 0. 51, 3 parts by weight of a glass transition temperature (Tg) of 209 ° C.) and octaisobutyl octasilsesquioxane (in the general formula (7), R = isobutyl group) 0 Using a twin screw extruder (trade name, ZSK-40; manufactured by WERNER & PFLEDERER, Germany) with 2 parts by weight set to a temperature of 280 to 310 ° C. and a screw rotation speed of 200 rpm, from the first raw material supply port of the extruder After supplying and melt-kneading, it was melt-extruded using a T-die extruder and formed into a film having a thickness of 50 μm. This film was contacted with an aqueous solution in which potassium hydroxide (15% by weight) and dimethyl sulfoxide (30% by weight) were dissolved at 60 ° C. for 4 hours to perform an alkali hydrolysis treatment. Then, it was immersed in 60 degreeC water for 4 hours. Next, it was immersed in a 2N hydrochloric acid aqueous solution at 60 ° C. for 3 hours, washed with ion-exchanged water and dried to obtain a proton exchange membrane (Ew: 798).

The proton conductivity of this proton exchange membrane is as high as 0.23 (S / cm). When the fuel cell was evaluated, the average value of the fluorine elution rate in the waste water from the start to 200 hours was 0.017 (μg / Hr / cm ² ) and a very low value. It has been found that the cell life exceeds 1000 hours and exhibits extremely excellent durability.
Moreover, the tensile elastic modulus of the proton exchange membrane is that of the proton exchange membrane of Comparative Example 1 using a precursor polymer obtained from tetrafluoroethylene and CF ₂ ═CFO (CF ₂ ) ₂ —SO ₂ F alone. About 1.3 times that of the proton exchange membrane of Comparative Example 2, which is a composition obtained by removing octaisobutyloctasilsesquioxane from the components of this membrane, it improves not only durability but also membrane strength. Turned out to be.

[Example 2]
100 parts by weight of polyphenylene ether (obtained by oxidative polymerization of 2,6-xylenol, reduced viscosity 0.51, glass transition temperature (Tg) 209 ° C.) and 5 parts by weight of heptaisobutylpropenyl octasilsesquioxane , Using a twin-screw extruder (trade name, ZSK-40; manufactured by WERNER & PFLIDEERER, Germany) set at a temperature of 280 ° C. and a screw rotation speed of 200 rpm, supplied from the first raw material supply port of the extruder, melt-kneaded, Pellets were obtained.

Precursor polymer obtained from 3 parts by weight of the above pellets, tetrafluoroethylene and CF ₂ ═CFO (CF ₂ ) ₂ —SO ₂ F (MI: 3.0, Ew after alkali hydrolysis / acid treatment: 730) ) 90 parts by weight and polyphenylene sulfide (melt viscosity (using a flow tester, 300 ° C., load 196 N / cm ² , L / D (L: orifice length, D: orifice inner diameter)) held at 6/1 for 6 minutes. The value measured afterwards.) Was set to 50 Pa · s, the extraction amount by methylene chloride was 0.7% by weight, and the amount of —SX group was 25 μmol / g). Using a double-screw extruder (trade name, ZSK-40; manufactured by WERNER & PFLEIDERER, Germany), melted and kneaded from the first raw material supply port of the extruder After was molded into 50μm thick film was melt extruded using a T-die extruder. This film was contacted with an aqueous solution in which potassium hydroxide (15% by weight) and dimethyl sulfoxide (30% by weight) were dissolved at 60 ° C. for 4 hours to perform an alkali hydrolysis treatment. Then, it was immersed in 60 degreeC water for 4 hours. Next, it was immersed in a 2N hydrochloric acid aqueous solution at 60 ° C. for 3 hours, washed with ion-exchanged water and dried to obtain a proton exchange membrane (Ew: 798).

The proton conductivity of this proton exchange membrane is as high as 0.23 (S / cm). When the fuel cell was evaluated, the average value of the fluorine elution rate in the waste water from the start to 200 hours was 0.015 (μg / Hr / cm ² ) and a very low value. It has been found that the cell life exceeds 1000 hours and exhibits extremely excellent durability.
Moreover, the tensile elastic modulus of the proton exchange membrane is that of the proton exchange membrane of Comparative Example 1 using a precursor polymer obtained from tetrafluoroethylene and CF ₂ ═CFO (CF ₂ ) ₂ —SO ₂ F alone. About 1.4 times the proton exchange membrane of Comparative Example 2, which is a composition obtained by removing heptaisobutylpropenyl octasilsesquioxane from the components of this membrane, about 1.4 times the durability, as well as improving the membrane strength Turned out to be.

[Example 3]
In Example 1, instead of 0.2 parts by weight of octaisobutyl octasilsesquioxane (in the general formula (7), R = isobutyl group) 0.1 parts by weight of heptaisobutyl epoxypropyl octasilsesquioxane A proton exchange membrane (Ew: 799) was obtained in the same manner as in Example 1 except that was used.
The proton conductivity of this proton exchange membrane is as high as 0.23 (S / cm). When the fuel cell was evaluated, the average value of the fluorine elution rate in the waste water from the start to 200 hours was 0.015 (μg / Hr / cm ² ) and a very low value. It has been found that the cell life exceeds 1000 hours and exhibits extremely excellent durability.

Moreover, the tensile elastic modulus of the proton exchange membrane is that of the proton exchange membrane of Comparative Example 1 using a precursor polymer obtained from tetrafluoroethylene and CF ₂ ═CFO (CF ₂ ) ₂ —SO ₂ F alone. About 1.3 times the proton exchange membrane of Comparative Example 2, which is a composition obtained by removing heptaisobutylepoxypropyl octasilsesquioxane from the components of this membrane, not only durability but also membrane strength It turns out that it is improving.

[Comparative Example 1]
A precursor polymer obtained from tetrafluoroethylene and CF ₂ ═CFO (CF ₂ ) ₂ —SO ₂ F (MI: 3.0, Ew after alkali hydrolysis / acid treatment: 730) was used alone. Produced a proton exchange membrane (EW: 730, MI: 3.0) in the same manner as in Example 1.
The proton conductivity of this proton exchange membrane was as high as 0.23 (S / cm). When this proton exchange membrane was evaluated for a fuel cell, the average value of the fluorine elution rate in the waste water from the start to the cell lifetime was as high as 0.506 (μg / Hr / cm ² ), and the cell lifetime was In less than 200 hours, sufficient durability was not obtained.

[Comparative Example 2]
The composition ratio of Example 1 was changed to 90 parts by weight of a precursor polymer obtained from tetrafluoroethylene and CF ₂ ═CFO (CF ₂ ) ₂ —SO ₂ F, 7 parts by weight of polyphenylene sulfide, and 3 parts by weight of polyphenylene ether. A proton exchange membrane (Ew: 797) was obtained in the same manner as in Example 1 except that the content was changed to 0 parts by weight of octaisobutyloctasilsesquioxane.
The proton conductivity of this proton exchange membrane is as high as 0.23 (S / cm). When the fuel cell was evaluated, the average value of the fluorine elution rate in the waste water from the start to 200 hours was 0.017 (μg / Hr / cm ² ) and a very low value. It has been found that the cell life exceeds 1000 hours and exhibits extremely excellent durability.

However, the tensile elastic modulus of this proton exchange membrane is that of the proton exchange membrane of Comparative Example 1 using a precursor polymer obtained from tetrafluoroethylene and CF ₂ ═CFO (CF ₂ ) ₂ —SO ₂ F alone. It was found that the durability was improved, but the film strength was not improved.

[Example 4]
100 parts by weight of polyphenylene ether (obtained by oxidative polymerization of 2,6-xylenol, reduced viscosity 0.51, glass transition temperature (Tg) 209 ° C.) and heptaisobutyl-3- (2-aminoethylamino) propyl -Using a twin-screw extruder (trade name, ZSK-40; manufactured by WERNER & PFLEDERER, Germany) with 5 parts by weight of octasilsesquioxane set to a temperature of 280 ° C and a screw rotation speed of 200 rpm, the first of the extruder It was supplied from the raw material supply port and melt-kneaded to obtain pellets.

Precursor polymer obtained from 1 part by weight of the above pellets, tetrafluoroethylene and CF ₂ ═CFO (CF ₂ ) ₂ —SO ₂ F (MI: 3.0, Ew after alkali hydrolysis / acid treatment: 730) ) 90 parts by weight and polyphenylene sulfide (melt viscosity (using a flow tester, 300 ° C., load 196 N / cm ² , L / D (L: orifice length, D: orifice inner diameter)) held at 6/1 for 6 minutes. The value measured later) was 50 Pa · s, the amount extracted with methylene chloride was 0.7% by weight, the amount of —SX group was 25 μmol / g) and 7 parts by weight of epoxy resin (Dainippon Ink & Chemicals, Inc.) A twin-screw extruder (trade name, ZSK) in which 2 parts by weight of a novolac type epoxy resin, trade name, N-660) is set at a temperature of 280 to 310 ° C. and a screw rotation speed of 200 rpm. 40; WERNER & PFLEIDERER Co., using Germany), was melt-kneaded by supplying from the first raw material supply port of the extruder, and molded molten extruded into a 50μm thick film using a T-die extruder. This film was contacted with an aqueous solution in which potassium hydroxide (15% by weight) and dimethyl sulfoxide (30% by weight) were dissolved at 60 ° C. for 4 hours to perform an alkali hydrolysis treatment. Then, it was immersed in 60 degreeC water for 4 hours. Next, it was immersed in a 2N hydrochloric acid aqueous solution at 60 ° C. for 3 hours, washed with ion-exchanged water and dried to obtain a proton exchange membrane (Ew: 801).

The proton conductivity of this proton exchange membrane is as high as 0.24 (S / cm). When the fuel cell was evaluated, the average value of the fluorine elution rate in the waste water from the start to 200 hours was 0.010 (μg / Hr / cm ² ) and a very low value. It has been found that the cell life exceeds 1000 hours and exhibits extremely excellent durability.
Moreover, the tensile elastic modulus of the proton exchange membrane is that of the proton exchange membrane of Comparative Example 1 using a precursor polymer obtained from tetrafluoroethylene and CF ₂ ═CFO (CF ₂ ) ₂ —SO ₂ F alone. About 1.6 times, about 1.2 times that of the proton exchange membrane of Comparative Example 3 having a composition obtained by removing heptaisobutyl-3- (2-aminoethylamino) propyl-octacylsesquioxane from the components of this membrane It was found that not only the durability but also the film strength was improved.

[Comparative Example 3]
The composition ratio of Example 1 was changed to 90 parts by weight of a precursor polymer obtained from tetrafluoroethylene and CF ₂ ═CFO (CF ₂ ) ₂ —SO ₂ F, 7 parts by weight of polyphenylene sulfide, and 1 part by weight of polyphenylene ether. And 2 parts by weight of epoxy resin (Cresol novolak type epoxy resin, trade name, N-660, manufactured by Dainippon Ink and Chemicals, Inc.) and 0 part by weight of octaisobutyl octasilsesquioxane. In the same manner as in Example 1, a proton exchange membrane (Ew: 802) was obtained.
The proton conductivity of this proton exchange membrane is as high as 0.24 (S / cm). When the fuel cell was evaluated, the average value of the fluorine elution rate in the waste water from the start to 200 hours was 0.010 (μg / Hr / cm ² ) and a very low value. It has been found that the cell life exceeds 1000 hours and exhibits extremely excellent durability.

However, the tensile modulus of this proton exchange membrane was about 0.8 times that of the proton exchange membrane of Example 4, and was obtained from tetrafluoroethylene and CF ₂ ═CFO (CF ₂ ) ₂ —SO ₂ F. Although improved compared with the proton exchange membrane of Comparative Example 1 using the precursor polymer alone, it was found that the degree was smaller than that of Example 4.

  The proton exchange membrane obtained from the polymer electrolyte composition of the present invention is a proton exchange membrane having high durability even at high temperatures, and is suitably used in the fields of ion exchange membranes and fuel cells. The proton exchange membrane obtained by the present invention can be used in various fuel cells including direct methanol fuel cells, water electrolysis, hydrohalic acid electrolysis, salt electrolysis, oxygen concentrators, humidity sensors, gas sensors and the like. is there.

Claims (10)

  Polymer compound (A) having an ion exchange group, polyphenylene sulfide resin (B), polyphenylene ether resin (C), and caged silsesquioxane or partially cleaved structure of caged silsesquioxane (D) A polymer electrolyte composition comprising:   Polymer compound (A) having an ion exchange group, polyphenylene sulfide resin (B), polyphenylene ether resin (C), and caged silsesquioxane or partially cleaved structure of caged silsesquioxane (D) And a polymer electrolyte composition comprising an epoxy group-containing compound (E).   The polymer electrolytic composition according to claim 2, wherein the epoxy group-containing compound (E) is a homopolymer or copolymer (F) of an unsaturated monomer having an epoxy group.   The polymer electrolytic composition according to claim 2, wherein the epoxy group-containing compound (E) is an epoxy resin (G).   3. The polymer electrolyte composition according to claim 2, comprising at least an epoxy-modified polyphenylene ether (H) formed by a reaction of the polyphenylene ether resin (C) and the epoxy resin (G) in the polymer electrolyte composition. A polymer electrolyte composition.   The polymer electrolyte composition according to claim 1 or 2, wherein the polymer compound (A) having an ion exchange group is a perfluorocarbon polymer compound having an ion exchange group. 7. The polymer electrolyte composition according to claim 6, wherein the perfluorocarbon polymer compound having an ion exchange group has a structural unit represented by the following general formula (1).
-[CF ₂ CX ¹ X ² ] _a- [CF ₂ -CF (-O- (CF ₂ -CF (CF ₂ X ³ )) _b -O _c- (CFR ¹ ) _d- (CFR ² ) _e- ( CF ₂ ) _f -X ⁴ )] _g- (1) (wherein X ¹ , X ² and X ³ are each independently a halogen element or a perfluoroalkyl group having 1 to 3 carbon atoms, 0 ≦ a <1 , 0 <g ≦ 1, a + g = 1, b is an integer of 0 or more and 8 or less, c is 0 or 1, and d, e and f are each independently an integer of 0 or more and 6 or less (where d + e + f is 0) R ¹ and R ² are each independently a halogen element, a perfluoroalkyl group or a fluorochloroalkyl group having 1 to 10 carbon atoms, and X ⁴ is COOZ, SO ₃ Z, PO ₃ Z _2. , PO ₃ HZ (Z is a hydrogen atom, an alkali metal atom, an alkaline earth metal atom, an amine (NH ₄ , NH ₃ R, NH ₂ R ₂ , NHR ₃ , NR ₄ (R is Alkyl group or arene group))   A proton exchange membrane comprising the polymer electrolyte composition according to any one of claims 1 to 7.   A membrane electrode assembly comprising the proton exchange membrane according to claim 8.   A polymer electrolyte fuel cell comprising the membrane electrode assembly according to claim 9.