JP4602845B2 - Solid polymer electrolyte membrane obtained by addition copolymerization of unsaturated silicon group-containing organosilicon compound and phosphate group-containing unsaturated monomer, and use thereof - Google Patents

Description

  The present invention relates to a solid polymer electrolyte membrane suitable for electrolyte membranes such as primary batteries, secondary batteries, fuel cells, display elements, various sensors, signal transmission media, solid capacitors, ion exchange membranes, etc. The present invention relates to a solid polymer electrolyte membrane exhibiting high proton conductivity over a humidity range and its use.

  Polymers belonging to so-called cation exchange resins such as polystyrene sulfonic acid, polyvinyl sulfonic acid, perfluorosulfonic acid polymer, perfluorocarboxylic acid polymer [Polymer Preprints, Japan Vol. 42, No. 7, pp. 2490-2492 (1993), Polymer Preprints, Japan Vol. 43, No. 3, pp. 735-736 (1994), Polymer Preprints, Japan Vol. 42, No. 3, p. 730 (1993)] etc. Has been reported.

  In particular, a solid polymer material having a sulfonic acid group in the side chain has a property of binding firmly to a specific ion or selectively transmitting a cation or an anion. It is formed into a shape or a membrane and is used in various applications such as electrodialysis membranes, diffusion dialysis membranes, and battery membranes. Above all, fluoropolymer electrolyte membranes with a sulfonic acid group in the side chain of the perfluoro skeleton known by the trademark Nafion (manufactured by DuPont) have excellent heat resistance and chemical resistance, and are used under severe conditions. Has been put to practical use as an electrolyte membrane that can withstand However, the fluorine-based electrolyte membrane as described above has a problem that it is very expensive and inferior to the environment.

  Under such circumstances, JP-A-2003-86021 discloses a phosphate group-containing unsaturated monomer having at least one phosphate group and at least one ethylenically unsaturated bond in the molecule, and 1 in the molecule. A solid polymer electrolyte membrane comprising a copolymer of at least one sulfonic acid group and a sulfonic acid group-containing unsaturated monomer having at least one ethylenically unsaturated bond is proposed. This solid polymer electrolyte membrane can be manufactured at a relatively low cost, is extremely high in conductivity, has low temperature dependence of conductivity, and is excellent in heat resistance and solvent resistance. It was a line.

  However, when a solid polymer electrolyte membrane is used in a fuel cell, particularly a direct methanol solid polymer fuel cell, a fuel composed of methanol and water is directly supplied to a fuel electrode provided on one surface of the solid polymer electrolyte membrane. In addition to conductivity, solvent resistance and water resistance are required. JP 2005-5046 (Patent Document 1) discloses an addition copolymerization of an alkoxysilane having a (meth) acrylate group or a hydrolysis product thereof and a (meth) acrylate having a phosphate group. And a solid polymer electrolyte formed by siloxane crosslinking. This solid polymer electrolyte membrane has excellent heat resistance, solvent resistance, and water resistance due to having polysiloxane, and has high conductivity due to a phosphate group.

  However, in recent years, in order to reduce the humidifier and associated devices of the fuel cell system and reduce the system construction cost, the solid polymer electrolyte membrane for fuel cells has excellent proton conductivity even under low humidity. It has been demanded.

JP 2005-5046

  Accordingly, an object of the present invention is to provide a solid polymer electrolyte membrane having a low proton conductivity-dependent humidity dependency, which is obtained by copolymerizing an organosilicon compound having an unsaturated bond and an unsaturated monomer having a phosphate group. And providing use.

  As a result of diligent research in view of the above object, the present inventors have (a) an organosilicon compound having an ethylenically unsaturated bond but having no alkoxy group and silanol group, and (b) an unsaturated group having a phosphate group. The inventors have found that a solid polymer electrolyte membrane having high proton conductivity and low proton conductivity humidity dependency can be obtained by addition copolymerization with a monomer, and the present invention has been conceived.

（ただしR ¹³ は水素基又はアルキル基であり、R ¹⁴ は置換又は無置換のアルキレン基であり、xは１〜６の整数である。）により表される化合物と、
下記一般式(6)：

（ただしR ¹⁵ 及びR ¹⁷ はそれぞれ独立に水素基又はアルキル基であり、R ¹⁶ 及びR ¹⁸ はそれぞれ独立に置換又は無置換のアルキレン基であり、x'及びx''はそれぞれ独立に１〜６の整数である。）により表されるリン酸基含有ジエステル系不飽和単量体、下記一般式(7):

（ただしR ¹⁹ 及びR ²¹ はそれぞれ独立に水素基又はアルキル基であり、R ²⁰ 及びR ²² はそれぞれ独立に置換又は無置換のアルキレン基であり、y及びy'はそれぞれ独立に１〜６の整数である。）により表されるピロリン酸基含有不飽和単量体、及び下記一般式(8):

（ただしR ²³ 、R ²⁵ 及びR ²⁷ はそれぞれ独立に水素基又はアルキル基であり、R ²⁴ 、R ²⁶ 及びR ²⁸ はそれぞれ独立に置換又は無置換のアルキレン基であり、z、z'及びz''はそれぞれ独立に１〜６の整数である。）により表されるリン酸基含有トリエステル系不飽和単量体からなる群から選ばれた少なくとも一種と
の混合物からなることを特徴とする。
That is, the first solid polymer electrolyte membrane of the present invention has (a) a main skeleton composed of polysiloxane, and an organic group is bonded to each silicon atom of the polysiloxane main skeleton by a silicon-carbon bond. An unsaturated silicon-containing organosilicon compound having a side chain and a terminal, wherein at least one of the organic groups has an ethylenically unsaturated bond; and (b) a phosphate group and an ethylenically unsaturated bond in the molecule. And a phosphate group-containing unsaturated monomer each having one or more thereof, and a solid polymer electrolyte membrane that is substantially not siloxane-crosslinked , comprising the phosphate group-containing unsaturated monomer. The mass is
The following general formula (5):

Wherein R ¹³ is a hydrogen group or an alkyl group, R ¹⁴ is a substituted or unsubstituted alkylene group, and x is an integer of 1 to 6, and
The following general formula (6):

(However, R ¹⁵ and R ¹⁷ are each independently a hydrogen group or an alkyl group, R ¹⁶ and R ¹⁸ are each independently a substituted or unsubstituted alkylene group, and x ′ and x ″ are each independently 1 to 1) A phosphoric acid group-containing diester unsaturated monomer represented by the following general formula (7):

(However, R ¹⁹ and R ²¹ are each independently a hydrogen group or an alkyl group, R ²⁰ and R ²² are each independently a substituted or unsubstituted alkylene group, and y and y ′ are each independently 1-6. A pyrophosphate group-containing unsaturated monomer represented by the following general formula (8):

(However, R ²³ , R ²⁵ and R ²⁷ are each independently a hydrogen group or an alkyl group, R ²⁴ , R ²⁶ and R ²⁸ are each independently a substituted or unsubstituted alkylene group, and z, z ′ and z '' Is each independently an integer of 1 to 6.) and at least one selected from the group consisting of phosphate group-containing triester unsaturated monomers
It consists of the mixture of these, It is characterized by the above-mentioned.

（ただしR ²⁹ 〜R ³² はそれぞれ独立に水素基又はメチル基であり、R ³³ はアルキレン基である。）により表される４官能性ウレタン（メタ）アクリレート、下記一般式(10)：

（ただしR ^29' 〜R ^31' はそれぞれ独立に水素基又はメチル基であり、R ^33' はアルキレン基である。）により表される３官能性ウレタン（メタ）アクリレート、及び下記一般式(11)：

（ただしR ^29'' 及びR ^31'' はそれぞれ独立に水素基又はメチル基であり、R ^33'' はアルキレン基である。）により表される２官能性ウレタン（メタ）アクリレートからなる群から選ばれた少なくとも一種であることを特徴とする。
The second solid polymer electrolyte membrane of the present invention has (a) a main skeleton composed of polysiloxane, and an organic group is bonded to each silicon atom of the polysiloxane main skeleton by a silicon-carbon bond to form a side chain. And an unsaturated silicon-containing organosilicon compound in which at least one of the organic groups has an ethylenically unsaturated bond, and (b) a phosphate group and an ethylenically unsaturated bond in the molecule, respectively. One or more phosphate group-containing unsaturated monomers and (c) a curing agent containing two or more ethylenically unsaturated bonds in the molecule are copolymerized and are substantially not crosslinked with siloxane. A solid polymer electrolyte membrane, wherein the curing agent has the following general formula (9):

(Wherein R ^{29 to} R ³² are each independently a hydrogen group or a methyl group, and R ³³ is an alkylene group.), A tetrafunctional urethane (meth) acrylate represented by the following general formula (10):

(Wherein R ^{29 ′ to} R ^{31 ′} each independently represents a hydrogen group or a methyl group, and R ^{33 ′} represents an alkylene group), and a trifunctional urethane (meth) acrylate represented by the following general formula (11 ):

(However, R ^{29 ″} and R ^{31 ″} are each independently a hydrogen group or a methyl group, and R ^{33 ″} is an alkylene group.) From the group consisting of bifunctional urethane (meth) acrylates represented by It is characterized by being at least one selected .

（ただしR¹〜R⁴はそれぞれ独立にエチレン性不飽和結合を有する有機基、置換もしくは無置換のアルキル基又はアリール基であり、かつR¹〜R⁴のいずれかはエチレン性不飽和結合を有する有機基であり、R⁵及びR⁶はそれぞれ独立に置換もしくは無置換のアルキル基又はアリール基であり、m及びnは各々１以上の整数である。）により表される化合物であるのが好ましい。R ¹ 〜R ⁴ はそれぞれ独立に下記式(12)：

（ただしR ³⁴ は置換又は無置換の炭素数１〜６のアルキレン基であり、R ³⁵ は水素基又はメチル基である。）により表される（メタ）アクリレート基、置換もしくは無置換の炭素数１〜６のアルキル基、又は炭素数６〜12のアリール基であり、かつR ¹ 〜R ⁴ のいずれかが前記（メタ）アクリレート基であるのが好ましい。R ⁵ 及びR ⁶ はそれぞれ独立に置換もしくは無置換の炭素数１〜６のアルキル基又は炭素数６〜12のアリール基であるのが好ましい。
The organosilicon compound has the following general formula (1):

(However, R ^{1 to} R ⁴ are each independently an organic group having an ethylenically unsaturated bond, a substituted or unsubstituted alkyl group or an aryl group, and any of R ^{1 to} R ⁴ represents an ethylenically unsaturated bond. R ⁵ and R ⁶ are each independently a substituted or unsubstituted alkyl group or aryl group, and m and n are each an integer of 1 or more.) preferable. R ^{1 to} R ⁴ are each independently the following formula (12):

(Wherein R ³⁴ is a substituted or unsubstituted alkylene group having 1 to 6 carbon atoms, and R ³⁵ is a hydrogen group or a methyl group), a (meth) acrylate group, a substituted or unsubstituted carbon number 1-6 alkyl group or an aryl group having 6 to 12 carbon atoms, and preferably one of R ¹ to R ⁴ are the (meth) acrylate groups. R ⁵ and R ⁶ are preferably each independently a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms.

（ただしR¹'〜R³'はそれぞれ独立に前記（メタ）アクリレート基、メチル基又はフェニル基であり、かつR¹'〜R³'のいずれかは前記（メタ）アクリレート基であり、m及びnは各々１以上の整数である。）により表される化合物がより好ましい。
Among the organosilicon compounds represented by the formula (1), the following general formula (3):

(Wherein R ¹ '~R ^3' are each independently the (meth) acrylate group, a methyl group or a phenyl group, and any of R ¹ '~R ^3' is said (meth) acrylate group, m And n are each an integer of 1 or more).

（ただしR⁷は水素基又はアルキル基であり、R⁸は置換又は無置換のアルキレン基であり、R⁹〜R¹²はそれぞれ独立に置換もしくは無置換のアルキル基又はアリール基であり、pは０〜２の整数である。）により表される化合物である。R ⁸ は置換又は無置換の炭素数１〜６のアルキレン基であるのが好ましい。R ⁹ 〜R ¹² はそれぞれ独立に置換もしくは無置換の炭素数１〜６のアルキル基又は炭素数６〜12のアリール基であるのが好ましい。
In another preferred example of the present invention, the organosilicon compound has the following general formula (2):

(However, R ⁷ is a hydrogen group or an alkyl group, R ⁸ is a substituted or unsubstituted alkylene group, R ^{9 to} R ¹² are each independently a substituted or unsubstituted alkyl group or an aryl group, and p is It is an integer of 0-2. R ⁸ is preferably a substituted or unsubstituted alkylene group having 1 to 6 carbon atoms. R ^{9 to} R ¹² are preferably each independently a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms.

（ただしR⁷'は水素基又はメチル基である。）により表される化合物がより好ましい。 Among the organosilicon compounds represented by the formula (2), the following general formula (4):

A compound represented by (wherein R ⁷ ′ is a hydrogen group or a methyl group) is more preferred.

  The compound represented by the formula (1) and the compound represented by the formula (2) may be used alone or in combination.

In the second solid polymer electrolyte membrane, the phosphate group-containing unsaturated monomer comprises (b-1) a compound represented by the general formula (5), or (b-2) the general formula ( 5), a phosphoric acid group-containing diester unsaturated monomer represented by the general formula (6), a pyrophosphate group-containing unsaturated monomer represented by the general formula (7) And a mixture with at least one selected from the group consisting of a phosphate group-containing triester unsaturated monomer represented by the general formula (8).

R ¹³ of the compound represented by the general formula (5) is preferably a —H group or a —CH ₃ group, and R ¹⁴ is a — (CH ₂ ) ₂ — group, —CH ₂ CH ₂ (CH ₃ ). It is preferably a — group, a —CH ₂ CH ₂ (CH ₂ Cl) — group or a — (CH ₂ ) ₄ — group. R ¹⁵ and R ¹⁷ of the phosphate group-containing diester unsaturated monomer represented by the general formula (6) are preferably each independently an —H group or a —CH ₃ group, and R ¹⁶ and R ¹⁸ Each independently represents a — (CH ₂ ) ₂ — group, a —CH ₂ CH ₂ (CH ₃ ) — group, a —CH ₂ CH ₂ (CH ₂ Cl) — group or a — (CH ₂ ) ₄ — group. preferable. In the pyrophosphate group-containing unsaturated monomer represented by the general formula (7), R ¹⁹ and R ²¹ are preferably each independently -H group or -CH ₃ group, and R ²⁰ and R ²² are each Independently, it is preferably a — (CH ₂ ) ₂ — group, —CH ₂ CH ₂ (CH ₃ ) — group, —CH ₂ CH ₂ (CH ₂ Cl) — group or — (CH ₂ ) ₄ — group. R ²³ , R ²⁵ and R ²⁷ of the phosphate group-containing triester unsaturated monomer represented by the general formula (8) are preferably each independently an —H group or a —CH ₃ group, ²⁴ , R ²⁶ and R ²⁸ are each independently-(CH ₂ ) ₂ -group, -CH ₂ CH ₂ (CH ₃ )-group, -CH ₂ CH ₂ (CH ₂ Cl)-group or-(CH ₂ ) _{A 4} -group is preferred.

The solid polymer electrolyte membrane may also contain an unsaturated compound other than the organosilicon compound and the phosphate group-containing unsaturated monomer as a copolymer component. The other unsaturated compound includes ( d ) an unsaturated compound having one or more ethylenically unsaturated bonds but no acid group in the molecule, and / or ( e ) an ethylenically unsaturated bond in the molecule. It is preferably an unsaturated compound having at least one acidic group. The ( d ) unsaturated compound having no acidic group has (meth) acrylonitrile, (meth) acrylamide, (meth) acrylic acid ester, conjugated diene-based liquid oligomer having (meth) acrylic group, and (meth) acrylic group From the group consisting of hydrogenated conjugated diene liquid oligomers, vinylated aromatic-conjugated diene liquid oligomers or derivatives thereof, substituted or unsubstituted styrene, vinyl halides, fatty acid substituted vinyl esters, and fluorine group-containing unsaturated monomers. It is preferably at least one selected. Derivatives of vinylated aromatic-conjugated diene liquid oligomers are (i) any of (meth) acrylic groups, isocyanate groups, hydroxyl groups, alkoxy groups, epoxy groups, hydrocarbon groups, urethane bonds, ester bonds and ether bonds. The compound is preferably a compound obtained by subjecting the vinyl aromatic-conjugated diene liquid oligomer to either the treatment to be introduced and (ii) the hydrogenation treatment. The unsaturated compound having an acidic group ( e ) preferably has at least one selected from the group consisting of a sulfonic acid group, a carboxylic acid group, a phosphonic acid group and a boric acid group.

The solid polymer electrolyte membrane according to a preferred embodiment of the present invention has a proton conductivity of 1 × 10 ⁻³ S / cm or more at a relative humidity of 95% or less and a temperature of room temperature to 60 ° C.

  The method for producing a solid polymer electrolyte membrane according to the present invention includes a solution containing the obtained solid polymer electrolyte by addition copolymerization of at least the organosilicon compound and the phosphate group-containing unsaturated monomer in a solvent. Alternatively, the dispersion is cast on a horizontal support to remove the solvent.

  In the above production method, (a) a solution or dispersion containing the phosphate group-containing unsaturated monomer is dropped into a solution or dispersion containing the organosilicon compound, or (b) the phosphate group-containing A solution or dispersion containing the organosilicon compound is dropped into a solution or dispersion containing a saturated monomer, or (c) the solution or dispersion containing the organosilicon compound and the phosphate group-containing unsaturated monolayer. It is preferable that the solution or dispersion containing the monomer is mixed together and subjected to addition copolymerization in the presence of a polymerization initiator. The solvent includes (a) an aliphatic alcohol having 1 to 6 carbon atoms, and (b) at least one selected from the group consisting of dimethylformamide, N, N-dimethylacetamide, tetrahydrofuran and dimethyl sulfoxide, A mixed solvent with ˜6 aliphatic alcohols is preferred.

  The solid polymer electrolyte membrane of the present invention is suitable for fuel cell applications.

  The solid polymer electrolyte membrane of the present invention has high proton conductivity and low humidity dependency of proton conductivity. In particular, it exhibits excellent proton conductivity even at low humidity below 95% relative humidity. When the solid polymer electrolyte membrane of the present invention having such characteristics is used as an electrolyte membrane for a fuel cell, the humidifier of the fuel cell system and its associated device can be reduced, and the system construction cost can be reduced. Further, the solid polymer electrolyte membrane of the present invention is suitably used for an electrolyte membrane for a primary battery, an electrolyte membrane for a secondary battery, a display element membrane, various sensor membranes, a signal transmission medium membrane, a solid capacitor membrane, an ion exchange membrane, and the like. it can.

[1] Raw material and blending ratio of solid polymer electrolyte membrane The solid polymer electrolyte membrane of the present invention comprises at least (a) an unsaturated bond-containing organosilicon compound having at least one ethylenically unsaturated bond in the molecule; b) It is formed by addition copolymerization with a phosphate group-containing unsaturated monomer each having at least one phosphate group and ethylenically unsaturated bond in the molecule, and is substantially not crosslinked with siloxane. Hereinafter, the unsaturated bond-containing organosilicon compound, the phosphate group-containing unsaturated monomer, the blending ratio thereof, and other unsaturated compounds that can be copolymerized will be described.

（ただしR¹〜R⁴はそれぞれ独立にエチレン性不飽和結合を有する有機基、置換もしくは無置換のアルキル基又はアリール基であり、かつR¹〜R⁴のいずれかはエチレン性不飽和結合を有する有機基であり、R⁵及びR⁶はそれぞれ独立に置換もしくは無置換のアルキル基又はアリール基であり、m及びnは各々１以上の整数である。）により表すことができる。 (1) Unsaturated Bond-Containing Organosilicon Compound Unsaturated bond-containing organosilicon compound (hereinafter simply referred to as “organosilicon compound” unless otherwise specified) has the following general formula (1):

(However, R ^{1 to} R ⁴ are each independently an organic group having an ethylenically unsaturated bond, a substituted or unsubstituted alkyl group or an aryl group, and any of R ^{1 to} R ⁴ represents an ethylenically unsaturated bond. R ⁵ and R ⁶ are each independently a substituted or unsubstituted alkyl group or aryl group, and m and n are each an integer of 1 or more.

  As shown in the formula (1), the organosilicon compound has a main skeleton composed of polysiloxane, and an organic group is bonded to each silicon atom of the polysiloxane main skeleton to form a side chain and a terminal. It has at least one ethylenically unsaturated bond inside. The silicon atom and the organic group have a silicon-carbon bond. The atomic ratio of carbon atoms to silicon atoms in the molecule (C / Si atomic ratio) is preferably 2 or more.

（ただしR³⁴は置換又は無置換のアルキレン基であり、R³⁵は水素基又はメチル基である。）により表される（メタ）アクリレート基が挙げられ、それ以外のものとして（メタ）アリルエステル基、ビニル基、メチルビニル基、（メタ）アリル基、スチリル基、エポキシ（メタ）アクリレート基等が挙げられるが、（メタ）アクリレート基が好ましい。（メタ）アクリレート基のアルキレン基R³⁴の炭素数は特に制限されないが、１〜６が好ましい。アルキレン基R³⁴の具体例として、メチレン基、エチレン基、プロピレン基、メチルエチレン基等が挙げられる。 Examples of the organic group (any one of R ^{1 to} R ⁴ ) having an ethylenically unsaturated bond in the formula (1) include the following formula (12):

(Wherein R ³⁴ is a substituted or unsubstituted alkylene group, and R ³⁵ is a hydrogen group or a methyl group), and a (meth) allyl ester represented by the others. Group, vinyl group, methylvinyl group, (meth) allyl group, styryl group, epoxy (meth) acrylate group, and the like, and (meth) acrylate group is preferable. The number of carbon atoms of the alkylene group R ³⁴ of the (meth) acrylate group is not particularly limited, but 1 to 6 is preferable. Specific examples of the alkylene group R ³⁴ include a methylene group, an ethylene group, a propylene group, a methylethylene group, and the like.

When any of R ^{1 to} R ⁶ is a substituted or unsubstituted alkyl group, the number of carbon atoms is preferably 1 to 6. When any of R ^{1 to} R ⁶ is a substituted or unsubstituted aryl group, the number of carbon atoms is preferably 6 to 12. Specifically, the alkyl group is preferably a methyl group, and the aryl group is preferably a phenyl group. When any of R ^{1 to} R ⁶ is a substituted alkyl group or a substituted aryl group, as other atomic groups that may be substituted, a hydrocarbon group, a hydroxyl group, various acidic groups, an isocyanate group, a urethane bond, An ester bond, an ether bond, etc. are mentioned.

（ただしR¹'〜R³'はそれぞれ独立に（メタ）アクリレート基、メチル基又はフェニル基であり、かつR¹'〜R³'のいずれかは（メタ）アクリレート基であり、m及びnは各々１以上の整数である。）により表される化合物が好ましい。 Among these, as the organosilicon compound represented by the formula (1), the following general formula (3):

(However, R ¹ ′ to R ³ ′ are each independently a (meth) acrylate group, a methyl group or a phenyl group, and any of R ¹ ′ to R ³ ′ is a (meth) acrylate group, and m and n Are each an integer of 1 or more).

（ただしR⁷は水素基又はアルキル基であり、R⁸は置換又は無置換のアルキレン基であり、R⁹〜R¹²はそれぞれ独立に置換もしくは無置換のアルキル基又はアリール基であり、pは０〜２の整数である。）により表される化合物を用いてもよい。式(2)において、pが０のときR⁹は無い。 As an organosilicon compound, the following general formula (2):

(However, R ⁷ is a hydrogen group or an alkyl group, R ⁸ is a substituted or unsubstituted alkylene group, R ^{9 to} R ¹² are each independently a substituted or unsubstituted alkyl group or an aryl group, and p is It is an integer of 0-2.) You may use the compound represented by. In formula (2), when p is 0, there is no R ⁹ .

The number of carbon atoms of the alkylene group R ⁸ is not particularly limited, but is preferably 1-6. Specific examples of the alkylene group R ⁸ include methylene group, ethylene group, propylene group, methylethylene group and the like. When any of R ^{9 to} R ¹² is an alkyl group or an aryl group, their carbon number may be the same as R ^{1 to} R ⁶ . Specifically, the alkyl group is preferably a methyl group, and the aryl group is preferably a phenyl group.

（ただしR⁷'は水素基又はメチル基である。）により表される化合物が好ましい。 As the organosilicon compound represented by the formula (2), the following general formula (4):

A compound represented by (wherein R ⁷ ′ is a hydrogen group or a methyl group) is preferred.

  The average molecular weight of the organosilicon compound represented by the formula (1) is not particularly limited, but is preferably 500 to 20,000. The functional group (group having an ethylenically unsaturated bond) equivalent (g / mol) of the organosilicon compound represented by formula (1) or formula (2) is not particularly limited, but is preferably 300 to 10,000.

  The compound represented by the formula (1) and the compound represented by the formula (2) may be used alone or in combination. Among the compounds represented by the formula (3), for example, “X-22-2457” (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.) is a trifunctional commercial product. Among the compounds represented by the formula (3), as a bifunctional commercial product, for example, “X-22-164AS”, “X-22-164A”, “X-22-164B”, “X-22-164C” ”,“ X-21-5822 ”,“ X-22-5825 ”,“ X-22-2445 ”,“ X-22-2426 ”(the trade name, manufactured by Shin-Etsu Chemical Co., Ltd.). Among the compounds represented by formula (3), monofunctional commercial products include, for example, “X-24-8201”, “X-22-174DX” (trade names, manufactured by Shin-Etsu Chemical Co., Ltd.) and the like. . As a commercial item of each compound represented by Formula (4), there exists "X-22-2404" (brand name, the Shin-Etsu Chemical Co., Ltd. make) etc., for example.

（ただしR¹³は水素基又はアルキル基であり、R¹⁴は置換又は無置換のアルキレン基であり、xは１〜６の整数である。）により表すことができる。R¹は−H基又は−CH₃基であるのが好ましい。アルキレン基R¹⁴について、「置換又は無置換」であるとは、直鎖状又は分岐状であることも含む。アルキレン基R¹⁴の炭素数は２〜４が好ましい。 (2) Phosphoric acid group-containing unsaturated monomer The phosphoric acid group-containing unsaturated monomer is represented by the following general formula (5):

Wherein R ¹³ is a hydrogen group or an alkyl group, R ¹⁴ is a substituted or unsubstituted alkylene group, and x is an integer of 1 to 6. R ¹ is preferably a —H group or a —CH ₃ group. Regarding the alkylene group R ¹⁴ , “substituted or unsubstituted” includes linear or branched. The alkylene group R ¹⁴ preferably has 2 to 4 carbon atoms.

（ただしR¹³は水素基又はアルキル基であり、R^14'は水素基又は置換もしくは無置換のアルキル基であり、xは１〜６の整数である。）により表される化合物が好ましい。式(13)により表されるリン系酸残基含有不飽和単量体において、R^14'はH、CH₃又はCH₂Clであるのが好ましい。 The phosphoric acid residue-containing unsaturated monomer represented by the formula (5) is represented by the following general formula (13):

(Wherein R ¹³ is a hydrogen group or an alkyl group, R ^{14 ′} is a hydrogen group or a substituted or unsubstituted alkyl group, and x is an integer of 1 to 6). In the phosphoric acid residue-containing unsaturated monomer represented by the formula (13), R ^{14 ′} is preferably H, CH ₃ or CH ₂ Cl.

  Tables 1 and 2 show the structural formulas and physical properties of representative ones of the phosphate group-containing unsaturated monomers represented by the general formula (5), respectively. These monomers are sold by Unichemical Corporation under the trade name Phosmer (registered trademark). However, the phosphate group-containing unsaturated monomer that can be used in the present invention is not limited to these. The phosphate group-containing unsaturated monomer represented by the general formula (5) can be used alone, but two or more kinds may be used in combination.

  Among the phosphoric acid group-containing unsaturated monomers represented by the general formula (5), acid phosphooxybutyl acrylate is also available from Unichemical Co., Ltd. under the trade name “Phosmer BA”.

The phosphoric acid group may be dissociated or may form a complex salt. When forming a complex salt, in order to neutralize the charge, for example, ammonium ions containing mono-, di- or tri-alkyl groups such as primary, secondary, tertiary or quaternary alkyl groups, allyl groups, aralkyl groups, etc. It is preferable to form a complex salt with an alkanolamine residue, particularly N ⁺ R _{4 -f} (OH) _f (where R is an alkyl group having 1 to 18 carbon atoms, an aromatic group having 6 to 12 carbon atoms, and 6 carbon atoms). Represents at least one selected from the group consisting of -12 alicyclic groups, and f represents a positive integer of 1-3.

（ただしR¹⁵及びR¹⁷はそれぞれ独立に水素基又はアルキル基であり、R¹⁶及びR¹⁸はそれぞれ独立に置換又は無置換のアルキレン基であり、x'及びx''はそれぞれ独立に１〜６の整数である。）により表されるリン酸基含有ジエステル系不飽和単量体、下記一般式(7):

（ただしR¹⁹及びR²¹はそれぞれ独立に水素基又はアルキル基であり、R²⁰及びR²²はそれぞれ独立に置換又は無置換のアルキレン基であり、y及びy'はそれぞれ独立に１〜６の整数である。）により表されるピロリン酸基含有不飽和単量体、及び下記一般式(8):

（ただしR²³、R²⁵及びR²⁷はそれぞれ独立に水素基又はアルキル基であり、R²⁴、R²⁶及びR²⁸はそれぞれ独立に置換又は無置換のアルキレン基であり、z、z'及びz''はそれぞれ独立に１〜６の整数である。）により表されるリン酸基含有トリエステル系不飽和単量体も使用可能である。各アルキレン基R¹⁶、R¹⁸、R²⁰、R²²、R²⁴、R²⁶及びR²⁸の炭素数は２〜４が好ましい。 As the phosphate group-containing unsaturated monomer, the following general formula (6):

(However, R ¹⁵ and R ¹⁷ are each independently a hydrogen group or an alkyl group, R ¹⁶ and R ¹⁸ are each independently a substituted or unsubstituted alkylene group, and x ′ and x ″ are each independently 1 to 1) A phosphoric acid group-containing diester unsaturated monomer represented by the following general formula (7):

(However, R ¹⁹ and R ²¹ are each independently a hydrogen group or an alkyl group, R ²⁰ and R ²² are each independently a substituted or unsubstituted alkylene group, and y and y ′ are each independently 1-6. A pyrophosphate group-containing unsaturated monomer represented by the following general formula (8):

(However, R ²³ , R ²⁵ and R ²⁷ are each independently a hydrogen group or an alkyl group, R ²⁴ , R ²⁶ and R ²⁸ are each independently a substituted or unsubstituted alkylene group, and z, z ′ and z '' Each independently represents an integer of 1 to 6.) A phosphate group-containing triester unsaturated monomer represented by the following formula can also be used. Each alkylene group R ¹⁶ , R ¹⁸ , R ²⁰ , R ²² , R ²⁴ , R ²⁶ and R ²⁸ preferably has 2 to 4 carbon atoms.

（ただしR¹⁵及びR¹⁷はそれぞれ独立に水素基又はアルキル基であり、R^16'及びR^18'はそれぞれ独立に水素基又は置換もしくは無置換のアルキル基であり、x'及びx''はそれぞれ独立に１〜６の整数である。）により表される化合物が好ましい。 Examples of the phosphoric acid group-containing diester unsaturated monomer represented by the general formula (6) include the following general formula (14):

(However, R ¹⁵ and R ¹⁷ are each independently a hydrogen group or an alkyl group, R ^{16 ′} and R ^{18 ′} are each independently a hydrogen group or a substituted or unsubstituted alkyl group, and x ′ and x ″ are Each independently represents an integer of 1 to 6).

（ただしR¹⁹及びR²¹はそれぞれ独立に水素基又はアルキル基であり、R^20'及びR^22'はそれぞれ独立に水素基又は置換もしくは無置換のアルキル基であり、y及びy'はそれぞれ独立に１〜６の整数である。）により表される化合物が好ましい。 Examples of the pyrophosphate group-containing unsaturated monomer represented by the general formula (7) include the following general formula (15):

(However, R ¹⁹ and R ²¹ are each independently a hydrogen group or an alkyl group, R ^{20 ′} and R ^{22 ′} are each independently a hydrogen group or a substituted or unsubstituted alkyl group, and y and y ′ are each independently Is an integer of 1 to 6.).

（ただしR²³、R²⁵及びR²⁷はそれぞれ独立に水素基又はアルキル基であり、R^24'、R^26'及びR^28'はそれぞれ独立に水素基又は置換もしくは無置換のアルキル基であり、z、z'及びz''はそれぞれ独立に１〜６の整数である。）により表される化合物が好ましい。 As the phosphate group-containing triester unsaturated monomer represented by the general formula (8), the following general formula (16):

(However, R ²³ , R ²⁵ and R ²⁷ are each independently a hydrogen group or an alkyl group, and R ^{24 ′} , R ^{26 ′} and R ^{28 ′} are each independently a hydrogen group or a substituted or unsubstituted alkyl group, z, z ′ and z ″ are each independently an integer of 1 to 6).

  As the phosphoric acid group-containing diester unsaturated monomer, di (methacryloyloxyethyl) phosphate and di (acryloyloxyethyl) phosphate are preferable. As the pyrophosphate group-containing unsaturated monomer, di (methacryloyloxyethyl) acid pyrophosphate and di (acryloyloxyethyl) acid pyrophosphate are preferable.

  The phosphate group-containing unsaturated monomer represented by the general formula (5) is excellent in proton conductivity, and the phosphate group-containing unsaturated monomer represented by the general formulas (6) to (8) is Since it has a curing action and is excellent in film forming properties, a phosphate group-containing unsaturated monomer represented by the general formula (5) and a phosphate group represented by the general formulas (6) to (8) You may use together at least 1 type chosen from the group which consists of a contained unsaturated monomer. Such a combination improves the balance of proton conductivity, solvent resistance and membrane strength of the membrane. Among them, it is preferable to use a phosphate group-containing unsaturated monomer represented by the general formulas (5) and (6) in combination. At least selected from the group consisting of a phosphate group-containing unsaturated monomer represented by the general formula (5) and a phosphate group-containing unsaturated monomer represented by the general formulas (6) to (8) When used in combination with one kind, the formula [phosphate group-containing unsaturated monomer represented by formula (5)] / [phosphate group-containing unsaturated monomer represented by formulas (6) to (8) It is preferable that the blending molar ratio represented by [total of the monomers] is 1 / 0.05 to 1/2.

  When the solid polymer electrolyte membrane contains the phosphate group-containing unsaturated monomer component as described above, a high water retention capability can be imparted to the solid polymer electrolyte, and a highly conductive membrane can be obtained.

(3) Blending ratio The blending ratio of the organosilicon compound and the phosphate group-containing unsaturated monomer is not particularly limited as long as it does not gel during the addition copolymerization reaction in the solvent, but in molar ratio (organosilicon compound) / (Phosphate group-containing unsaturated monomer) = 90/10 to 10/90 is preferable, and this ratio is more preferably 90/10 to 50/50. If this ratio is less than 10/90, the effect of improving the heat resistance of the copolymer may be insufficient. On the other hand, if it exceeds 90/10, the phosphoric acid group is insufficient and the proton conductivity is insufficient. There is a risk of becoming.

(4) Other unsaturated compounds that can be copolymerized The solid polymer electrolyte membrane may contain an unsaturated compound other than the organosilicon compound and the phosphate group-containing unsaturated monomer as a copolymerization component. Other unsaturated compounds include the following two groups (a) unsaturated compounds having one or more ethylenically unsaturated bonds in the molecule but no acidic groups, and (b) ethylenically unsaturated bonds in the molecule. It can be roughly divided into unsaturated compounds each having one or more acidic groups.

(a) Unsaturated compounds that do not contain acidic groups Solid polymer electrolyte membranes are unsaturated compounds that do not contain acidic groups (unsaturated non-acidic groups) for the purpose of improving film-forming properties, water resistance, chemical resistance, etc. Compound) may be included as a copolymerization component. Non-acidic group-containing unsaturated compounds include all unsaturated compounds that are not gaseous at room temperature and have one or more ethylenically unsaturated bonds in the molecule. Among them, (meth) acrylonitrile, (meth) acrylamide, (Meth) acrylic acid ester, conjugated diene-based liquid oligomer or derivative thereof, vinylated aromatic-conjugated diene-based liquid oligomer or derivative thereof, substituted or unsubstituted styrene, vinyl halide (such as vinyl chloride), fatty acid-substituted vinyl At least one selected from the group consisting of esters (for example, vinyl acetate) and fluorine-containing unsaturated monomers is preferred.

(i) (Meth) acrylic acid ester As (meth) acrylic acid ester, for example, alkyl (meth) acrylate such as methyl (meth) acrylate and ethyl (meth) acrylate; ethylene glycol di (meth) acrylate; trimethylolpropane tri ( (Meth) acrylate; hexamethylenediol di (meth) acrylate and the like.

（ただしR²⁹〜R³²はそれぞれ独立に水素基又はメチル基であり、R³³はアルキレン基である。）により表されるウレタン（メタ）アクリレートも挙げられる。 As the (meth) acrylic acid ester, the following general formula (9):

(However, R ^{29 to} R ³² are each independently a hydrogen group or a methyl group, and R ³³ is an alkylene group.)

  The (meth) acrylic acid ester may contain an alcoholic hydroxyl group. Examples of the (meth) acrylic acid ester containing an alcoholic hydroxyl group include glycerol dimethacrylate [for example, “Blemmer GMR”, “GMR-R”, “GMR-H” (manufactured by Nippon Oil & Fats Co., Ltd.), etc.] Glycerol di (meth) acrylate such as glycerol methacrylate acrylate [for example, trade name “Blemmer GAM”, “same GAM-R” (manufactured by Nippon Oil & Fats Co., Ltd.)]; 1,6-hexanediol diglycidyl ether acrylate [for example Product name “NK Oligo EA-5521” (manufactured by Shin-Nakamura Chemical Co., Ltd.), etc.]; 1,4-butanediol diglycidyl ether acrylate [eg, product name “NK Oligo EA-5520” (manufactured by Shin-Nakamura Chemical Co., Ltd.) ) Etc.]; Bisphenol A type epoxy acrylate [for example, “NK Oligo EA-1020” (manufactured by Shin-Nakamura Chemical Co., Ltd.) etc.]; 2-Hydro Examples thereof include 2-hydroxy (meth) acrylate such as xylmethyl (meth) acrylate and 2-hydroxyethyl (meth) acrylate.

（ただしR^29'〜R^31'はそれぞれ独立に水素基又はメチル基であり、R^33'はアルキレン基である。）により表される３官能性ウレタン（メタ）アクリレート、下記一般式(11)：

（ただしR^29''及びR^31''はそれぞれ独立に水素基又はメチル基であり、R^33''はアルキレン基である。）により表される２官能性ウレタン（メタ）アクリレート等も挙げられる。 As the (meth) acrylic acid ester containing an alcoholic hydroxyl group, the following general formula (10):

(Wherein R ^{29 ′ to} R ^{31 ′} each independently represents a hydrogen group or a methyl group, and R ^{33 ′} represents an alkylene group), a trifunctional urethane (meth) acrylate represented by the following general formula (11) :

(However, R ^{29 ″} and R ^{31 ″} are each independently a hydrogen group or a methyl group, and R ^{33 ″} is an alkylene group.) .

  The above-mentioned 2-4 functional urethane (meth) acrylate is obtained by reacting, for example, diisocyanate and glycerol diacrylate. As a commercial product, for example, “NK Oligo U-4HA” (trade name, Shin-Nakamura Chemical Co., Ltd.) Etc.).

（ただしR³⁶及びR³⁷はそれぞれ独立に(I) エチレン性不飽和結合を１個以上有し、かつ他の原子団を有してもよい炭化水素基、(II) エチレン性不飽和結合を有さず、かつ他の原子団を有してもよい炭化水素基又は(III) 水素基であり、かつR³⁶及びR³⁷の少なくとも一方は上記(I)のエチレン性不飽和結合を有する炭化水素基であり、R³⁸及びR³⁹はそれぞれ独立に水素基又はメチル基であり、かつR³⁸及びR³⁹の少なくとも一方は水素基であり、rは重合度である。）により表されるものがより好ましい。ただし共役ジエン系液状オリゴマーとしては、式(17)に示すような重合体鎖中の共役ジエン単位が1, 2−結合であるものに限定する趣旨ではなく、共役ジエン単位が1, 4−結合であるものであってもよい。 (ii) Conjugated diene-based liquid oligomer As the conjugated diene-based liquid oligomer, at least one selected from the group consisting of a butadiene oligomer having at least one ethylenically unsaturated bond in the molecule, an isoprene oligomer, and derivatives thereof is preferable. . As the conjugated diene liquid oligomer, the following general formula (17):

(However, R ³⁶ and R ³⁷ are each independently (I) a hydrocarbon group which has one or more ethylenically unsaturated bonds and may have other atomic groups, and (II) an ethylenically unsaturated bond. A hydrocarbon group which does not have and may have another atomic group or (III) a hydrogen group, and at least one of R ³⁶ and R ³⁷ has the ethylenically unsaturated bond of (I) above. A hydrogen group, R ³⁸ and R ³⁹ are each independently a hydrogen group or a methyl group, and at least one of R ³⁸ and R ³⁹ is a hydrogen group, and r is the degree of polymerization. Is more preferable. However, the conjugated diene-based liquid oligomer is not limited to those in which the conjugated diene unit in the polymer chain is a 1,2-bond as shown in the formula (17), but the conjugated diene unit is a 1,4-bond. It may be what is.

Specific examples of R ³⁶ and R ³⁷ include a (meth) acryl group. Examples of the other atomic group that R ³⁶ and R ³⁷ may have include at least one selected from the group consisting of a urethane bond, an ester bond, an ether bond, an isocyanate group, a hydroxyl group, and an alkoxy group. The conjugated diene-based liquid oligomer may contain other conjugated diene as a polymerization component, if necessary.

  Although there is no restriction | limiting in particular in the molecular weight of a conjugated diene type liquid oligomer, A thing with a number average molecular weight of 500-50,000 is preferable. Examples of commercially available conjugated diene liquid oligomers represented by the formula (17) include “NISSO-PB TEA-1000” and “NISSO-PB TE-2000” (manufactured by Nippon Soda Co., Ltd.).

（ただしR³⁶〜R³⁹及びrは式(17)と同じである。）により表されるものが好ましい。式(18)により表される水素化共役ジエン系液状オリゴマーの市販品として、例えば「NISSO-PB TEAI-1000」（日本曹達株式会社製）等がある。 The conjugated diene liquid oligomer may be hydrogenated. The hydrogenated conjugated diene-based liquid oligomer has the following general formula (18):

(Wherein R ^{36 to} R ³⁹ and r are the same as those in formula (17)) are preferred. Examples of commercially available hydrogenated conjugated diene liquid oligomers represented by the formula (18) include “NISSO-PB TEAI-1000” (manufactured by Nippon Soda Co., Ltd.).

(iii) Vinylated aromatic-conjugated diene-based liquid oligomer The vinylated aromatic-conjugated diene-based copolymer comprises a copolymer having at least a vinylated aromatic unit and a conjugated diene unit. Styrene is preferred as the vinylated aromatic component. Isoprene is preferred as the conjugated diene component. The ratio of the vinylated aromatic component and the conjugated diene component in the vinylated aromatic-conjugated diene copolymer is not particularly limited, and the toughness, flexibility, mechanical strength, etc. required for the solid polymer electrolyte membrane are not limited. What is necessary is just to set suitably according to a physical property. The molecular weight of the vinylated aromatic-conjugated diene-based liquid oligomer is not particularly limited, and may be, for example, a mass average molecular weight of 1,000 to 100,000.

  The vinylated aromatic-conjugated diene copolymer may be a derivative modified by a treatment such as introduction of a functional group or other atomic group or hydrogenation. Examples of the functional group include a (meth) acryl group, an isocyanate group, a hydroxyl group, an alkoxy group, an epoxy group, and a hydrocarbon group. Examples of other atomic groups include a urethane bond, an ester bond, and an ether bond. Examples of commercially available vinylated aromatic-conjugated diene copolymers include “Claprene LIR-310” (manufactured by Kuraray Co., Ltd.).

(iv) Fluorine group-containing unsaturated monomer Examples of the fluorine group-containing unsaturated monomer include those described in JP-A-2005-11789. Specifically, hydrofluoroalkyl group-containing (meth) acrylic acid esters such as perfluorooctylethyl (meth) acrylate; perfluoroalkyl group-containing (meth) acrylic acid esters; α- (trifluoromethyl) acrylic acid, etc. Hydrofluoroalkyl group-containing (meth) acrylic acid; perfluoroalkyl group-containing vinyl such as perfluorobutylethylene, perfluorohexylethylene, perfluorooctylethylene, perfluorodecylethylene; hydrofluoroalkyl group-containing vinyl and the like are preferable. By including a fluorine group-containing unsaturated monomer as a copolymerization component, the heat resistance and water resistance of the solid polymer electrolyte membrane are further improved.

(v) A compound having no acidic group but containing a plurality of ethylenically unsaturated bonds in the molecule As an unsaturated compound having no acidic group in order to improve the solvent resistance of the solid polymer electrolyte membrane It is preferable to use a material containing a plurality of ethylenically unsaturated bonds and cure the solid polymer electrolyte membrane. As such a curing agent, 2- to 4-functional urethane (meth) acrylate, ethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate represented by the above formulas (9) to (11), respectively. , Hexamethylenediol di (meth) acrylate, glycerol di (meth) acrylate, 1,6-hexanediol diglycidyl ether acrylate, 1,4-butanediol diglycidyl ether acrylate, bisphenol A type epoxy acrylate, hexamethylenediol diacrylate , Conjugated diene liquid oligomers or derivatives thereof, and vinylated aromatic-conjugated diene liquid oligomers or derivatives thereof. Other examples include divinylbenzene.

(b) Unsaturated compound containing acidic group The acidic group is not particularly limited, and examples thereof include a sulfonic acid group, a carboxylic acid group, a phosphonic acid group, and a boric acid group. Among these, at least one selected from the group consisting of a sulfonic acid group, a carboxylic acid group, and a phosphonic acid group is preferable. Examples of the skeleton having an ethylenically unsaturated bond include a (meth) acrylate skeleton, a (meth) allyl ester skeleton, a substituted or unsubstituted unsaturated aliphatic hydrocarbon skeleton, and an aromatic hydrocarbon skeleton substituted with an unsaturated group. Can be mentioned.

(i) Unsaturated monomer containing sulfonic acid group Examples of the unsaturated monomer containing a sulfonic acid group include those described in JP-A-2004-179154. Specifically, tertiary butyl acrylamide sulfonic acid, allyl sulfonic acid, methallyl sulfonic acid, vinyl sulfonic acid, p-styrene sulfonic acid, (meth) acrylic acid butyl-4-sulfonic acid, (meth) acrylooxybenzene Sulfonic acid and the like are preferable. These may be used alone or in combination of two or more.

(ii) Unsaturated monomer containing a carboxylic acid group Examples of unsaturated monomers containing a carboxylic acid group include (meth) acrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, maleic acid. An acid anhydride etc. are mentioned. These may be used alone or in combination of two or more.

（ただしR⁴⁰及びR⁴¹はそれぞれ独立に水素基又はメチル基である。）により表される化合物、及び下記式(20)：

（ただしR⁴⁰及びR⁴¹はそれぞれ独立に水素基又はメチル基である。）により表される化合物が好ましい。 (iii) Phosphate esterified product of (meth) acrylic acid ester containing alcoholic hydroxyl group The (meth) acrylic acid ester containing the above alcoholic hydroxyl group may be converted to a phosphate ester. In particular, a phosphate esterified product of an alcoholic hydroxyl group-containing unsaturated monomer having two or more ethylenically unsaturated groups in the molecule has good curability. Among such phosphoric acid ester products, a compound obtained by phosphorylating glycerol di (meth) acrylate, that is, the following formula (19):

(Wherein R ⁴⁰ and R ⁴¹ are each independently a hydrogen group or a methyl group), and the following formula (20):

(However, R ⁴⁰ and R ⁴¹ are each independently a hydrogen group or a methyl group.)

  In order to convert the alcoholic hydroxyl group-containing unsaturated monomer to phosphoric ester, for example, 0.5 to 0.6 molar equivalent of phosphoric anhydride is added to the hydroxyl group of the alcoholic hydroxyl group-containing unsaturated monomer and reacted. What is necessary is just to hydrolyze the reaction product obtained according to it.

(iv) Acid Group-Introduced Derivatives of Conjugated Diene Liquid Oligomers (Hydrogenated) conjugated diene liquid oligomers represented by the above formulas (17) and (18) are R ³⁶ and R ^{36 in} formulas (17) and (18) R ³⁷ may be a derivative in which a carboxylic acid group, a sulfonic acid group, a phosphoric acid group or the like is introduced.

(v) Phosphonic acid group-containing (meth) acrylamide derivatives Phosphonic acid group-containing (meth) acrylamide derivatives react (meth) acrylamide monomers with phosphoric acid source compounds and hydrolyze the resulting reaction product. It is a decomposition product. Specific examples include acrylamide phosphonic acid, acrylamide diphosphonic acid, and phosphonic acid group-containing tertiary butyl acrylamide sulfonic acid.

(vi) Acid group-introduced derivative of vinylated aromatic-conjugated diene-based liquid oligomer The vinylated aromatic-conjugated diene-based liquid oligomer is a derivative having a carboxylic acid group, a sulfonic acid group, a phosphoric acid group or the like introduced therein. May be.

(vii) A monomer having an acidic group and containing a plurality of ethylenically unsaturated bonds in the molecule. In order to improve the solvent resistance (for example, methanol resistance) of the solid polymer electrolyte membrane, it is acidic. As the unsaturated compound containing a group, a solid polymer electrolyte membrane may be cured using a curing agent containing a plurality of ethylenically unsaturated bonds. Examples of such curing agents include phosphate group-containing unsaturated monomers represented by the above formulas (6) to (8), and glycerol di (meta) represented by the above formulas (19) and (20). ) A phosphate ester of acrylate is preferred.

(c) Addition amount of other unsaturated compound The addition amount of the other unsaturated compound is not particularly limited as long as it does not gel when it is copolymerized with an organosilicon compound and a phosphate group-containing unsaturated monomer in a solvent. The amount of the other unsaturated compound added is generally preferably 50% by mass or less, and preferably 40% by mass, with the total of the organosilicon compound, phosphate group-containing unsaturated monomer and other unsaturated compound being 100% by mass. The following is more preferable. Although not intended to limit, the addition amount of the curing agent is preferably 10% by mass or less.

(5) Other polymers that can be mixed In order to further improve the film-forming properties when producing solid polymer electrolyte membranes, the strength, hydrophobicity, solvent resistance, etc. of the obtained solid polymer electrolyte membranes, Other (co) polymers compatible with the copolymer forming the molecular electrolyte membrane can be mixed. Examples of other (co) polymers include polyamide, polyvinyl alcohol, polyacrylamide, polyacrylic acid, melamine, cellulose, and modified products thereof. The solid polymer electrolyte membrane of the present invention may have a configuration in which a membrane made of another (co) polymer is used as a support membrane.

[2] Production method of solid polymer electrolyte membrane The solid polymer electrolyte membrane of the present invention is prepared by preparing a solution obtained by copolymerizing at least the organosilicon compound and the phosphate group-containing unsaturated monomer in a solvent, It can manufacture by forming the obtained solid polymer electrolyte solution into a film by the casting method.

(1) Preparation of solid polymer electrolyte by copolymerization First, (a) A solution or dispersion containing a phosphate group-containing unsaturated monomer is dropped into a solution or dispersion containing an organosilicon compound, or (b) A solution or dispersion containing an organosilicon compound is dropped into a solution or dispersion containing a phosphate group-containing unsaturated monomer, or (c) a solution or dispersion containing an organosilicon compound and a phosphate group-containing A solution or dispersion containing a saturated monomer is mixed together and subjected to addition copolymerization in the presence of a polymerization initiator.

  A solution or dispersion (organosilicon compound-containing liquid) comprising the following (organosilicon compound + solvent) comprises [phosphate group-containing unsaturated monomer + polymerization initiator + solvent (+ other unsaturated compound)]. A method of adding a solution or dispersion (phosphate group-containing unsaturated monomer-containing solution) dropwise and carrying out addition copolymerization will be described. As the solvent, a common solvent in which the organosilicon compound, the phosphate group-containing unsaturated monomer, and the copolymer to be produced are all dissolved is used. Such solvents include (a) aliphatic alcohol solvents having 1 to 6 carbon atoms, and (b) dimethylformamide (DMF), N, N-dimethylacetamide (DMAc), tetrahydrofuran (THF) and dimethyl sulfoxide (DMSO). A mixed solvent of at least one selected from the group consisting of C 1-6 aliphatic alcohols is preferred. As the aliphatic alcohol having 1 to 6 carbon atoms, butanol is more preferable, and n-butanol is particularly preferable. Each of the solvents (a) and (b) may be used alone or in combination.

  As polymerization initiators, 2, 2'-azobisisobutyronitrile (AIBN), 2, 2'-azobis (2,4-dimethylvaleronitrile), dimethyl 2, 2'-azobis (2-methylpropio) And azo initiators such as dimethyl 2,2′-azobisisobutyrate, or peroxide initiators such as lauryl peroxide, benzoyl peroxide, tert-butyl peroxy pivalate, and the like.

  The polymerization procedure is described. First, an organosilicon compound-containing liquid is put into a stirrer, an adder, and a reactor equipped with a reflux condenser, and a phosphate group-containing unsaturated monomer-containing liquid is put into an adder. The concentration of the unsaturated compound component in the phosphate group-containing unsaturated monomer-containing liquid is preferably 5 to 30% by mass. The temperature inside the reactor is raised to a temperature of 40 ° C. to 100 ° C., preferably 50 ° C. to 100 ° C., while nitrogen is passed through the gas phase in the reactor. Immediately after reaching the predetermined temperature, the phosphate group-containing unsaturated monomer-containing liquid in the adder is dropped over a predetermined time. The dropping time is preferably 15 to 120 minutes.

  After the total amount of the phosphate group-containing unsaturated monomer-containing liquid is added to the organosilicon compound-containing liquid, copolymerization is performed for 1 to 10 hours. After the total amount of the phosphate group-containing unsaturated monomer-containing liquid is added to the organosilicon compound-containing liquid, the polymerization initiator may be added again as necessary. The copolymerization temperature is preferably 85 ° C to 100 ° C. The copolymerization temperature does not need to be constant from the beginning to the end, and a method of increasing the copolymerization rate by increasing the temperature within the above range at the end of the copolymerization and reducing the unreacted monomer as much as possible may be adopted.

  The concentration of the raw material [phosphate group-containing unsaturated monomer + organosilicon compound (+ other unsaturated compound)] in the polymerization solution is preferably as high as possible, but from the viewpoint of the stirring strength of the reaction tester, 20 It is preferable that it is below mass%. If the raw material concentration in the polymerization solution is more than 20% by mass, a gelled product may be generated during the reaction. The total amount of the polymerization initiator used is preferably 0.005 to 0.5% by mass, more preferably 0.01 to 0.3% by mass based on 100% by mass of the phosphate group-containing unsaturated monomer.

  The batch mixing method may be essentially the same as the dropping method described above except that the phosphate group-containing unsaturated monomer-containing solution is added to the organosilicon compound-containing solution at once.

(2) Film formation by casting method A film is formed by casting method using a copolymer solution prepared by addition copolymerization. When the other (co) polymer is mixed, it is added in advance to a solid electrolyte solution or dispersion and dissolved or dispersed. In the casting method, a solution or dispersion of a solid electrolyte is cast on a horizontal support (for example, a glass plate, a tray, etc.), and the solvent used in the polymerization reaction is evaporated. The solvent is evaporated by reducing and / or heating the cast solution or dispersion. Specifically, it is preferable to heat and dry at 90 to 150 ° C. for about 1 to 180 minutes. The pressure during the heat drying treatment is preferably normal pressure to 10 mmHg (absolute pressure).

  It is preferable to further heat the formed film (coating), whereby condensation occurs between phosphoric acid groups incorporated in the copolymer, and mechanical strength and solvent resistance are improved. Specifically, it is preferable to heat and dry at 90 to 100 ° C. for about 20 minutes to 3 hours. The pressure during the heat drying treatment is preferably normal pressure to 10 mmHg (absolute pressure).

  The film obtained by evaporating the solvent by decompression and / or heating preferably extracts impurities (residual solvent, unreacted components such as monomers). Extraction is performed by immersing the membrane in a poor solvent and then removing it. As the poor solvent, water, methanol and the like are preferable. The amount of the poor solvent used for one extraction operation is 10 to 100 times the volume of the membrane. The immersion temperature is usually room temperature, and if necessary, the film may be heated to such an extent that the film does not deteriorate. Regarding the immersion time, for example, when extraction is performed at room temperature using water or methanol as a poor solvent, the impurities can be substantially extracted by one extraction operation if immersed for about 24 hours. You may repeat extraction by a poor solvent as needed.

  The thickness of the solid polymer electrolyte membrane of the present invention is usually 30 to 200 μm, preferably 30 to 150 μm. The film made of the solid polymer copolymer of the present invention has a methanol extraction rate of 15% by mass or less when impurities are not extracted after copolymerization, but the methanol resistance is not particularly excellent. Here, the methanol extraction rate is obtained by measuring the mass loss after the membrane was immersed in a large excess of methanol at room temperature for 24 hours and dried at 105 ° C. for 10 minutes.

  The solid polymer electrolyte membrane of the present invention having such characteristics is preferably used after being extracted with a poor solvent (methanol) as described above when used in a direct methanol solid polymer fuel cell.

[3] Characteristics of the solid polymer electrolyte membrane The solid polymer electrolyte membrane of the present invention obtained by the production method as described above is obtained by addition copolymerization of the organosilicon compound and a phosphate group-containing unsaturated monomer. And substantially free of siloxane crosslinking. Here, “substantially not siloxane crosslinked” means that the polysiloxane main skeleton (main chain) derived from the organosilicon compound does not have a structure in which siloxane bonds are formed (siloxane crosslinked structure). As described above, in the organosilicon compound, the side chain and the terminal are formed of an organic group, and the organic group is bonded to each silicon atom of the linear polysiloxane main skeleton through a silicon-carbon bond. A part of the organic group may be substituted with a hydrogen group. In this case, the hydrogen group is bonded to the silicon atom of the polysiloxane main skeleton through a silicon-hydrogen bond. Therefore, the organosilicon compound does not contain an alkoxy group or a silanol group. Therefore, even when a solid polymer electrolyte membrane is produced by the method as described above, a siloxane cross-linking structure is generally not generated because a siloxane bond generated by a condensation reaction (sol-gel reaction) between alkoxy groups or between silanol groups and alkoxy groups is not generated. Is not formed. There is no restriction | limiting in particular in the copolymer structure of a solid polymer electrolyte membrane, For example, any of a block copolymer or a graft copolymer may be sufficient.

The solid polymer electrolyte membrane of the present invention has excellent proton conductivity with a conductivity of 10 ⁻⁴ to 10 ⁻² S / cm under a relative humidity of 50 to 95% and a temperature of 30 to 90 ° C., Such proton conductivity has low temperature dependency and humidity dependency. For example, even when measuring relative humidity from 90% to 50% at a temperature of 50 ° C, or when measuring relative humidity from 50% to 90% at a temperature of 50 ° C, proton-conductive humidity The dependency is small. In particular, the proton conductivity at a relative humidity of 50% and a temperature of 50 ° C. is 1 × 10 ⁻³ S / cm or more.

  For this reason, when the solid polymer electrolyte membrane of the present invention is used, the humidifier and its associated device of the fuel cell system can be reduced, and the system construction cost can be reduced. Here, the conductivity is obtained from a resistance value obtained by performing plane complex impedance analysis on data measured by the complex impedance method and further performing cole-cole plot graphic processing. The solid polymer electrolyte membrane of the present invention is derived from (1) an organic silicon compound unit polysiloxane main skeleton and side chain / terminal organic groups, and an ethylenically unsaturated bond of a phosphate group-containing unsaturated monomer unit. Since it has a structure having a hydrophobic part consisting of a hydrocarbon skeleton and a hydrophilic part consisting of (2) a phosphate group derived from a phosphate group-containing unsaturated monomer, an ester bond and an alkylene oxide group, It is presumed that the hydrophilic part composed of an acid group or the like becomes an efficient proton conduction path.

[4] Fuel Cell The structure of the fuel cell may be a known one. Usually, a fuel cell can be formed by laminating a plurality of unit fuel cells (membrane-electrode assemblies) via separators. The unit fuel cell is composed of a solid polymer electrolyte membrane and an anode electrode and a cathode electrode bonded to both sides thereof. The electrode is composed of a gas diffusion layer (such as a porous carbon-based material) and a catalyst layer (such as platinum particles). The catalyst layer is formed by applying catalyst particles on the gas diffusion layer.

  The separator separates fuel gas (hydrogen, methane, methanol, etc.) and oxidant gas (oxygen or air), secures a flow path for the fuel gas and oxidant gas, and further generates electricity generated by the fuel cell. It plays a role to communicate outside. Accordingly, the separator is made of a conductive material such as a carbon material, a carbon composite material (such as a composite material of carbon and a thermosetting resin or a thermoplastic resin), a metal material, or a metal composite material (such as a composite material of a metal and carbon). It is formed. Further, a groove (reactive gas flow path) that forms a flow path for the fuel gas and the oxidant gas is formed on the surface of the separator at the contact portion with the electrode.

  The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Examples 1-18
Phosmer-containing unsaturated monomer (Phosmer) -containing liquid having the composition shown in Table 3 and an organosilicon compound (both ends methacryl-modified silicone, trade name “X-22-164AS”, Mw: 973, Shin-Etsu Chemical Co., Ltd.) Company-made) liquids (solvent: n-butanol, concentration: 10% by mass) were prepared, and copolymers were prepared according to the blending ratios shown in Table 4. Put a solution containing methacryl-modified silicone oil (X-22-164AS) at both ends into a reactor connected with a reflux condenser, dropping funnel, thermometer, and nitrogen gas inlet, and stir while introducing nitrogen gas into the gas phase The temperature was raised to a polymerization temperature of 80 ° C. After confirming that the internal temperature reached 80 ° C., the phosphate group-containing unsaturated monomer-containing liquid placed in the dropping funnel was added dropwise. Thereafter, copolymerization was performed for 3 hours to obtain a solution containing the copolymer. After cooling, the solution was cast on a Teflon (registered trademark) sheet, heated under reduced pressure to remove the solvent, and then heated under the conditions shown in Table 4 to produce a solid polymer electrolyte membrane.

Note: (1) n-butanol solvent. Contains 0.2% AIBN by weight with respect to Phosmer.
(2) Acid phosphooxypolyoxyethylene glycol monomethacrylate (molecular weight: 342).
(3) Acid phosphooxypolyoxypropylene glycol methacrylate (molecular weight: 456).
(4) Acid phosphooxyethyl methacrylate (molecular weight: 210).
(5) Product name “NK Oligo U-4HA” (Mw: 516, manufactured by Shin-Nakamura Chemical Co., Ltd.).

表４（続き）

表４（続き）

表４（続き）

表４（続き）

表４（続き）

Table 4 (continued)

Table 4 (continued)

Table 4 (continued)

Table 4 (continued)

Table 4 (continued)

Notes: (1) Acid phosphooxypolyoxyethylene glycol monomethacrylate (molecular weight: 342).
(2) Acid phosphooxypolyoxypropylene glycol methacrylate (molecular weight: 456).
(3) Acid phosphooxyethyl methacrylate (molecular weight: 210).
(4) Methacrylate modified silicone at both ends, trade name “X-22-164AS”, Mw: 973, manufactured by Shin-Etsu Chemical Co., Ltd.
(5) Product name “NK Oligo U-4HA” (Mw: 516, manufactured by Shin-Nakamura Chemical Co., Ltd.).
(6) The phosphate group-containing unsaturated monomer-containing solution is dropped into the organosilicon compound-containing solution.
(7) Initial concentration of raw material [phosphate group-containing unsaturated monomer + organosilicon compound (+ other unsaturated compound)] in the reaction solution.
(8) 2, 2 '-Azobisisobutyronitrile.
(9) Measured with a bismetholone viscometer.
(10) Measure the mass loss after immersing the membrane in a large excess of methanol at room temperature for 24 hours and drying at 105 ° C for 10 minutes.

<Methanol extraction test>
The mass loss after the solid polymer electrolyte membranes of Examples 1 to 18 were immersed in a large excess of methanol at room temperature for 24 hours and dried at 105 ° C. for 10 minutes was measured. Table 4 shows an excellent methanol extraction rate of 15% by mass or less in any membrane.

<Evaluation of proton conductivity>
Proton conductivity was measured using the complex impedance method. A 3 cm × 1 cm rectangular sample cut out from the membranes of Examples 1 to 18 was placed in an open impedance cell. This cell was installed in a thermo-hygrostat and impedance measurement was performed (relative humidity: 90%, measurement temperature: 35, 50, 65, 80 ° C.). The obtained data was subjected to planar complex impedance analysis, and the conductivity was obtained from the resistance value of the sample obtained by performing the cole-cole plot figure processing (the same applies hereinafter). The results are shown in FIGS.

  For the membranes of Examples 2, 7 and 8, the relative humidity was decreased stepwise at a constant temperature of 50 ° C. (relative humidity: 90, 70, 60, 50%), and the conductivity was measured by the impedance method at each relative humidity. Measurements were made. As a reference example, the same measurement was performed on a fluorine-based polymer electrolyte membrane (trade name “Nafion112”, manufactured by DuPont) having a sulfonic acid group in the side chain of the perfluoro skeleton. The results are shown in FIG.

  For the membranes of Examples 2, 7, and 8, the relative humidity was increased stepwise at a constant temperature of 50 ° C. (relative humidity: 50, 60, 70, 90%), and the conductivity was measured by the impedance method at each relative humidity. Measurements were made. As a reference example, Nafion 112 was measured in the same manner. The results are shown in FIG.

From the results shown in FIGS. 1 to 6, the electrical conductivity of the solid polymer electrolyte membranes of Examples 1 to 18 is 10 ⁻³ to 10 ⁻² S / cm at a relative humidity of 90% and a temperature range of 35 to 80 ° C. It can be seen that the polymer electrolyte having a phosphate group as a functional group is in a good level, and the temperature dependence of conductivity is small. Further, from the results shown in FIGS. 7 and 8, Nafion 112 has a decrease in conductivity as the humidity decreases at a temperature of 50 ° C. and a relative humidity range of 50 to 90%. It can be seen that the electrolyte membrane has a conductivity on the order of 10 ⁻³ to 10 ⁻² S / cm, and the conductivity is less dependent on humidity than Nafion 112. The solid polymer electrolyte membrane of the present invention was excellent in proton conductivity not only under high humidity but also under low humidity of 50%.

It is a graph which shows the relationship between temperature T (degreeC) and electrical conductivity log ((sigma) / S * cm < ^-1 >) by a cole-cole plot about the solid polymer electrolyte membrane of Examples 1-3. It is a graph which shows the relationship between temperature T (degreeC) and electrical conductivity log ((sigma) / S * cm < ^-1 >) by a cole-cole plot about the solid polymer electrolyte membrane of Example 4 and 5. FIG. It is a graph which shows the relationship between temperature T (degreeC) and electrical conductivity log ((sigma) / S * cm < ^-1 >) by a cole-cole plot about the solid polymer electrolyte membrane of Examples 6-8. It is a graph which shows the relationship between temperature T (degreeC) and electrical conductivity log ((sigma) / S * cm < ^-1 >) by a cole-cole plot about the solid polymer electrolyte membrane of Examples 9-11. It is a graph which shows the relationship between temperature T (degreeC) and electrical conductivity log ((sigma) / S * cm < ^-1 >) by a cole-cole plot about the solid polymer electrolyte membrane of Examples 12-15. It is a graph which shows the relationship between temperature T (degreeC) and electrical conductivity log ((sigma) / S * cm < ^-1 >) by a cole-cole plot about the solid polymer electrolyte membrane of Examples 16-18. For the solid polymer electrolyte membranes of Examples 2, 7, 8 and Reference Example, the relative humidity (%) and the conductivity log (σ / S · cm ⁻ when the conductivity was measured while the relative humidity was lowered stepwise It is a graph which shows the relationship with ¹ ) by a cole-cole plot. For the solid polymer electrolyte membranes of Examples 2, 7, 8 and Reference Example, the relative humidity (%) and the conductivity log (σ / S · cm ⁻ when the conductivity was measured while increasing the relative humidity stepwise. It is a graph which shows the relationship with ¹ ) by a cole-cole plot.

Claims (11)

(a) having a main skeleton composed of polysiloxane, each silicon atom of the polysiloxane main skeleton is bonded with an organic group by a silicon-carbon bond to form a side chain and a terminal, An unsaturated bond-containing organosilicon compound in which at least one of them has an ethylenically unsaturated bond, and (b) a phosphate group-containing unsaturated monomer having at least one phosphate group and one or more ethylenically unsaturated bonds in the molecule Is a solid polymer electrolyte membrane that is addition-copolymerized and is not substantially siloxane crosslinked, wherein the phosphate group-containing unsaturated monomer is,
The following general formula (5):

Wherein R ¹³ is a hydrogen group or an alkyl group, R ¹⁴ is a substituted or unsubstituted alkylene group, and x is an integer of 1 to 6, and
The following general formula (6):

(However, R ¹⁵ and R ¹⁷ are each independently a hydrogen group or an alkyl group, R ¹⁶ and R ¹⁸ are each independently a substituted or unsubstituted alkylene group, and x ′ and x ″ are each independently 1 to 1) A phosphoric acid group-containing diester unsaturated monomer represented by the following general formula (7):

(However, R ¹⁹ and R ²¹ are each independently a hydrogen group or an alkyl group, R ²⁰ and R ²² are each independently a substituted or unsubstituted alkylene group, and y and y ′ are each independently 1-6. A pyrophosphate group-containing unsaturated monomer represented by the following general formula (8):

(However, R ²³ , R ²⁵ and R ²⁷ are each independently a hydrogen group or an alkyl group, R ²⁴ , R ²⁶ and R ²⁸ are each independently a substituted or unsubstituted alkylene group, and z, z ′ and z '' Each independently represents an integer of 1 to 6.) characterized in that it comprises a mixture with at least one selected from the group consisting of phosphate group-containing triester unsaturated monomers. Solid polymer electrolyte membrane. 2. The solid polymer electrolyte membrane according to claim 1, wherein R ¹³ of the compound represented by the general formula (5) is a —H group or a —CH ₃ group, and R ¹⁴ is a — (CH ₂ ) ₂ — group. , —CH ₂ CH ₂ (CH ₃ ) — group, —CH ₂ CH ₂ (CH ₂ Cl) — group or — (CH ₂ ) ₄ — group, represented by the general formula (6) R ¹⁵ and R ¹⁷ of the contained diester unsaturated monomer are each independently —H group or —CH ₃ group, and R ¹⁶ and R ¹⁸ are each independently —— (CH ₂ ) ₂ — group, —CH _2. A CH ₂ (CH ₃ ) — group, a —CH ₂ CH ₂ (CH ₂ Cl) — group or a — (CH ₂ ) ₄ — group, and a pyrophosphate group-containing unsaturated single group represented by the general formula (7). R ¹⁹ and R ²¹ in the monomer are each independently —H group or —CH ₃ group, and R ²⁰ and R ²² are each independently — (CH ₂ ) ₂ — group, —CH ₂ CH ₂ (CH ₃ ). -Group, -CH ₂ CH ₂ (CH ₂ Cl)-group or-(CH ₂ ) ₄ -group, and a phosphate group-containing triester-based unsaturated compound represented by the general formula (8). R ²³ , R ²⁵ and R ²⁷ of the sum monomer are each independently -H group or -CH ₃ group, and R ²⁴ , R ²⁶ and R ²⁸ are each independently-(CH ₂ ) ₂ -group,- _{CH 2 CH 2 (CH 3)} - _{group, -CH 2 CH 2 (CH 2} Cl) - group or a - (CH _{2) 4} - solid polymer electrolyte membrane, which is a group. (a) having a main skeleton composed of polysiloxane, each silicon atom of the polysiloxane main skeleton is bonded with an organic group by a silicon-carbon bond to form a side chain and a terminal, An unsaturated bond-containing organosilicon compound in which at least one of them has an ethylenically unsaturated bond, and (b) a phosphate group-containing unsaturated monomer having at least one phosphate group and one or more ethylenically unsaturated bonds in the molecule And (c) a solid polymer electrolyte membrane that is copolymerized with a curing agent containing two or more ethylenically unsaturated bonds in the molecule and is substantially not crosslinked with siloxane , wherein the curing agent comprises: The following general formula (9):

(Wherein R ^{29 to} R ³² are each independently a hydrogen group or a methyl group, and R ³³ is an alkylene group.), A tetrafunctional urethane (meth) acrylate represented by the following general formula (10):

(Wherein R ^{29 ′ to} R ^{31 ′} each independently represents a hydrogen group or a methyl group, and R ^{33 ′} represents an alkylene group), and a trifunctional urethane (meth) acrylate represented by the following general formula (11 ):

(However, R ^{29 ″} and R ^{31 ″} are each independently a hydrogen group or a methyl group, and R ^{33 ″} is an alkylene group.) From the group consisting of bifunctional urethane (meth) acrylates represented by A solid polymer electrolyte membrane, which is at least one selected . 4. The solid polymer electrolyte membrane according to claim 3, wherein the phosphate group-containing unsaturated monomer is (b-1) the following general formula (5):

(Wherein R ¹³ is a hydrogen group or an alkyl group, R ¹⁴ is a substituted or unsubstituted alkylene group, and x is an integer of 1 to 6), or
(b-2) the compound represented by the general formula (5) and the following general formula (6):

(However, R ¹⁵ and R ¹⁷ are each independently a hydrogen group or an alkyl group, R ¹⁶ and R ¹⁸ are each independently a substituted or unsubstituted alkylene group, and x ′ and x ″ are each independently 1 to 1) A phosphoric acid group-containing diester unsaturated monomer represented by the following general formula (7):

(However, R ¹⁹ and R ²¹ are each independently a hydrogen group or an alkyl group, R ²⁰ and R ²² are each independently a substituted or unsubstituted alkylene group, and y and y ′ are each independently 1-6. A pyrophosphate group-containing unsaturated monomer represented by the following general formula (8):

(However, R ²³ , R ²⁵ and R ²⁷ are each independently a hydrogen group or an alkyl group, R ²⁴ , R ²⁶ and R ²⁸ are each independently a substituted or unsubstituted alkylene group, and z, z ′ and z '' Each independently represents an integer of 1 to 6.) characterized in that it comprises a mixture with at least one selected from the group consisting of phosphate group-containing triester unsaturated monomers. Solid polymer electrolyte membrane. 5. The solid polymer electrolyte membrane according to claim 4, wherein R ¹³ of the compound represented by the general formula (5) is a —H group or a —CH ₃ group, and R ¹⁴ is a — (CH ₂ ) ₂ — group. , —CH ₂ CH ₂ (CH ₃ ) — group, —CH ₂ CH ₂ (CH ₂ Cl) — group or — (CH ₂ ) ₄ — group, represented by the general formula (6) R ¹⁵ and R ¹⁷ of the contained diester unsaturated monomer are each independently —H group or —CH ₃ group, and R ¹⁶ and R ¹⁸ are each independently —— (CH ₂ ) ₂ — group, —CH _2. A CH ₂ (CH ₃ ) — group, a —CH ₂ CH ₂ (CH ₂ Cl) — group or a — (CH ₂ ) ₄ — group, and a pyrophosphate group-containing unsaturated single group represented by the general formula (7). R ¹⁹ and R ²¹ in the monomer are each independently —H group or —CH ₃ group, and R ²⁰ and R ²² are each independently — (CH ₂ ) ₂ — group, —CH ₂ CH ₂ (CH ₃ ). -Group, -CH ₂ CH ₂ (CH ₂ Cl)-group or-(CH ₂ ) ₄ -group, and a phosphate group-containing triester-based unsaturated compound represented by the general formula (8). R ²³ , R ²⁵ and R ²⁷ of the sum monomer are each independently -H group or -CH ₃ group, and R ²⁴ , R ²⁶ and R ²⁸ are each independently-(CH ₂ ) ₂ -group,- _{CH 2 CH 2 (CH 3)} - _{group, -CH 2 CH 2 (CH 2} Cl) - group or a - (CH _{2) 4} - solid polymer electrolyte membrane, which is a group. The solid polymer electrolyte membrane according to any one of claims 1 to 5 , wherein the organosilicon compound is represented by the following general formula (1):

(However, R ^{1 to} R ⁴ are each independently an organic group having an ethylenically unsaturated bond, a substituted or unsubstituted alkyl group or an aryl group, and any of R ^{1 to} R ⁴ represents an ethylenically unsaturated bond. And R ⁵ and R ⁶ are each independently a substituted or unsubstituted alkyl group or an aryl group, and m and n are each an integer of 1 or more, and / or The following general formula (2):

(However, R ⁷ is a hydrogen group or an alkyl group, R ⁸ is a substituted or unsubstituted alkylene group, R ^{9 to} R ¹² are each independently a substituted or unsubstituted alkyl group or an aryl group, and p is It is an integer of 0-2.) The solid polymer electrolyte membrane characterized by the above-mentioned. 7. The solid polymer electrolyte membrane according to claim 6 , wherein R ^{1 to} R ⁴ of the compound represented by the general formula (1) are each independently represented by the following formula (12):

(Wherein R ³⁴ is a substituted or unsubstituted alkylene group having 1 to 6 carbon atoms, and R ³⁵ is a hydrogen group or a methyl group), a (meth) acrylate group, a substituted or unsubstituted carbon number An alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms, and any one of R ^{1 to} R ⁴ is the (meth) acrylate group, and R ⁵ and R ⁶ are each independently substituted or unsubstituted. A substituted alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms, R ^{7 in the} compound represented by the general formula (2) is a hydrogen group or a methyl group, and R ⁸ is substituted or An unsubstituted alkylene group having 1 to 6 carbon atoms, and R ^{9 to} R ¹² are each independently a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms. Solid polymer electrolyte membrane. The solid polymer electrolyte membrane according to claim 7 , wherein the organosilicon compound is represented by the following general formula (3):

(However, R ^{1 ′ to} R ^{3 ′} are each independently the (meth) acrylate group, methyl group or phenyl group, and any of R ^{1 ′ to} R ^{3 ′} is the (meth) acrylate group, m And n are each an integer of 1 or more.) And / or the following general formula (4):

A solid polymer electrolyte membrane characterized by being a compound represented by the formula (wherein R ^{7 '} is a hydrogen group or a methyl group). The solid polymer electrolyte membrane according to any one of claims 1 to 8 , further comprising (I) (meth) acrylonitrile, (meth) acrylamide, (meth) acrylic acid ester, and a conjugated diene system having a (meth) acrylic group. Liquid oligomer, hydrogenated conjugated diene liquid oligomer having (meth) acrylic group, vinylated aromatic-conjugated diene liquid oligomer or derivative thereof, substituted or unsubstituted styrene, vinyl halide, fatty acid substituted vinyl ester and fluorine group At least one unsaturated compound (d) selected from the group consisting of unsaturated monomers containing (d), (II) at least one selected from the group consisting of sulfonic acid groups, carboxylic acid groups, phosphonic acid groups and boric acid groups An unsaturated compound (e) having an acidic group and at least one ethylenically unsaturated bond, or (III) of the unsaturated compounds (d) and (e) Including a compound as a copolymerization component, the derivative of the vinylated aromatic-conjugated diene liquid oligomer is (i) a (meth) acryl group, an isocyanate group, a hydroxyl group, an alkoxy group, an epoxy group, a hydrocarbon group, a urethane bond. A solid polymer characterized by being a compound obtained by subjecting the vinyl aromatic-conjugated diene-based liquid oligomer to any one of an ester bond and an ether bond treatment, and (ii) a hydrogenation treatment Electrolyte membrane. In the solid polymer electrolyte membrane according to any one of claims 1 to 9 that a proton conductivity at 95% or less relative humidity and a temperature of room temperature to 60 ° C. is 1 × 10 ^-3 S / cm or more A solid polymer electrolyte membrane. Fuel cell characterized by using a solid polymer electrolyte membrane according to any one of claims 1-10.

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