JP2005011790A - Phosphoric acid group content solid polyelectrolyte (composite) membrane and its manufacturing method, as well as its use - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solid polyelectrolyte (composite) membrane which has proton conductivity high enough to be used for a fuel cell or the like, and which is superior in heat resistance, chemical resistance and mechanical strength. <P>SOLUTION: This is the (composite) membrane wherein (A) an unsaturated monomer containing a phosphate group having one or more of phosphate groups and one or more of ethylenically unsaturated bonds in a molecule, and (B) an unsaturated monomer containing a fluorine group having one or more of fluorine groups and one or more of the ethylenically unsaturated monomers in a molecule is copolymerized, and wherein the fluorine group-containing unsaturated monomer contains at least one kind selected from a group consisting of (B-1) fluorine group-containing olefinically unsaturated monomer having one ethylenically unsaturated bond, and (B-2) fluorine group-containing diene-based unsaturated monomer having two ethylenically unsaturated bonds, and this (composite) membrane has the high proton conductivity, low temperature dependency in the proton conductivity, and superior in solvent resistance. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  TECHNICAL FIELD The present invention relates to a solid polymer electrolyte (composite) membrane suitable for an electrolyte membrane, a display element, various sensors, a signal transmission medium, a solid capacitor, an ion exchange membrane, and the like for a primary battery, a secondary battery, a fuel cell, etc. In particular, the present invention relates to a solid polymer electrolyte (composite) membrane excellent in solvent resistance, heat resistance and mechanical strength, and exhibiting high proton conductivity over a wide temperature range and humidity range, and uses thereof.

  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 to 2492 (1993), Polymer Preprints, Japan Vol. 43, No. 3, pp. 735 to 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 used for various applications such as electrodialysis membranes, diffusion dialysis membranes, and battery membranes. Above all, a fluoropolymer electrolyte membrane with a sulfonic acid group in the side chain of the perfluoro skeleton known by the Nafion trademark (DuPont) has excellent heat resistance and solvent resistance, and it can withstand use under harsh conditions. Practical use as a film. However, the fluorine-based electrolyte membrane as described above has a problem that it is very expensive.

  In contrast to these prior arts, the present inventors have obtained phosphorous obtained by polymerizing or copolymerizing (meth) acrylic acid esters containing a phosphate group with an ethylenically unsaturated monomer that can be copolymerized therewith. It has been proposed to prepare a proton conductive solid polymer electrolyte membrane by making an acid group-containing polymer into a solution and casting it into a film (Japanese Patent Laid-Open No. 2001-114834: Patent Document 1). The solid polymer electrolyte of Patent Document 1 can be provided not only at a relatively low cost, but the cast membrane obtained is excellent in heat resistance and exhibits high proton conductivity over a wide temperature range and humidity range. It was in line with solid polymer materials.

  Japanese Patent Laid-Open No. 2002-83514 (Patent Document 2) proposes a proton conductive membrane in which a polymer having a phosphoric acid group, a phosphonic acid group or a phosphinic acid group in the side chain is supported in the pores of the porous membrane. is doing. The proton conductive membrane of Patent Document 2 is prepared by polymerizing a monomer having a phosphoric acid group, a phosphonic acid group or a phosphinic acid group in the side chain in the pores of the porous membrane, so that the polymer is porous. It has a high degree of adhesion to the membrane and has not only high proton conductivity but also high strength.

Japanese Patent Laid-Open No. 2001-114834 JP 2002-83514 A

  However, the solid polymer electrolyte of Patent Document 1 and the proton conductive membrane of Patent Document 2 are not sufficient in solvent resistance when used as a solid polymer electrolyte membrane for a methanol fuel cell.

  Accordingly, an object of the present invention is to provide a solid polymer electrolyte (composite) membrane having high conductivity sufficient for use in fuel cells and the like, and excellent in solvent resistance, heat resistance, and mechanical strength, and uses thereof. It is to be.

  In view of the above object, as a result of earnest research, the present inventors have (A) a phosphate group-containing unsaturated monomer having one or more phosphate groups and one or more ethylenically unsaturated bonds in the molecule. And (B) a copolymer of a fluorine group-containing unsaturated monomer having one or more fluorine groups and one or more ethylenically unsaturated bonds in the molecule, and the fluorine group-containing unsaturated monomer And (B-1) a fluorine group-containing olefinic unsaturated monomer having one ethylenically unsaturated bond, and (B-2) a fluorine group-containing diene-unsaturated monomer having two ethylenically unsaturated bonds. Discovered that (composite) membranes with solid polymer electrolytes containing at least one selected from the group consisting of monomers exhibit high electrical conductivity and are excellent in solvent resistance, heat resistance and mechanical strength did. The present inventors also (A) a phosphoric acid group obtained by polymerizing a phosphoric acid group-containing unsaturated monomer having one or more phosphoric acid groups and one or more ethylenically unsaturated bonds in the molecule. And (B) a fluorine group-containing polymer obtained by polymerizing a fluorine group-containing unsaturated monomer having one or more fluorine groups and one or more ethylenically unsaturated bonds in the molecule. The fluorine-containing unsaturated monomer comprises (B-1) a fluorine-containing olefinically unsaturated monomer having one ethylenically unsaturated bond, and (B-2) an ethylenically unsaturated monomer. A solid polymer electrolyte (composite) film comprising at least one selected from the group consisting of fluorine-containing diene unsaturated monomers having two saturated bonds exhibits high conductivity, and is also resistant to solvents and heat. And it was found to be excellent in mechanical strength. The present invention has been completed based on this invention.

  That is, the first solid polymer electrolyte membrane comprises (A) a phosphate group-containing unsaturated monomer having one or more phosphate groups and one or more ethylenically unsaturated bonds in the molecule, and ( B) A solid polymer electrolyte membrane obtained by copolymerizing a fluorine group-containing unsaturated monomer having one or more fluorine groups and one or more ethylenically unsaturated bonds in the molecule, The unsaturated monomer contains (B-1) a fluorine group-containing olefinically unsaturated monomer having one ethylenically unsaturated bond, and (B-2) a fluorine group having two ethylenically unsaturated bonds. It contains at least one selected from the group consisting of a contained diene unsaturated monomer.

  The phosphate group-containing unsaturated monomer is a phosphate group-containing unsaturated monomer (I) having one acidic phosphate group and one ethylenically unsaturated bond in the molecule, and / or A phosphate group-containing unsaturated monomer (II) having one acidic phosphate group and two ethylenically unsaturated bonds in the molecule is preferred.

（ただしR₁は水素又はアルキル基であり、R₂は水素又は置換もしくは無置換のアルキル基であり、nは１〜６の整数である。）により表されるのが好ましい。R₁はH又はCH₃であり、R₂はH、CH₃又はCH₂Clであるのが好ましい。前記リン酸基含有不飽和単量体(I)のリン酸基はアミン塩又はアンモニウム塩を形成しているのが好ましい。 The phosphate group-containing unsaturated monomer (I) is represented by the following general formula (1):

(Wherein R ₁ is hydrogen or an alkyl group, R ₂ is hydrogen or a substituted or unsubstituted alkyl group, and n is an integer of 1 to 6). R ₁ is preferably H or CH ₃ and R ₂ is preferably H, CH ₃ or CH ₂ Cl. The phosphate group of the phosphate group-containing unsaturated monomer (I) preferably forms an amine salt or an ammonium salt.

（ただしR₃及びR₆はそれぞれ独立に水素又はアルキル基であり、R₄及びR₅はそれぞれ独立に水素又は置換もしくは無置換のアルキル基であり、m及びkはそれぞれ独立に１〜６の整数である。）により表されるのが好ましい。R₃及びR₆はそれぞれ独立にH又はCH₃であり、R₄及びR₅はそれぞれ独立にH、CH₃又はCH₂Clであるのが好ましい。 The phosphate group-containing unsaturated monomer (II) has the following general formula (2):

(However, R ₃ and R ₆ are each independently hydrogen or an alkyl group, R ₄ and R ₅ are each independently hydrogen or a substituted or unsubstituted alkyl group, and m and k are each independently 1-6. It is preferably an integer. Preferably R ₃ and R ₆ are each independently H or CH ₃ and R ₄ and R ₅ are each independently H, CH ₃ or CH ₂ Cl.

（ただしRf₁は１個以上のフッ素基を含有する１価の有機基であり、X₁、X₂及びX₃はそれぞれ独立に水素又はフッ素基である。）又は下記一般式(4)：

（ただしRf₂、Rf₃及びRf₄はそれぞれ独立に少なくとも１個の水素基がフッ素基により置換されたメチル基又はフッ素基であり、X₄はフッ素基、その他のハロゲン、少なくとも１個の水素基がフッ素基により置換されたメチル基、アルコキシ基、フッ素基含有アルコキシ基、アルキル基又は水素である。）により表されるものが好ましい。前記フッ素基含有オレフィン系不飽和単量体は、ヘキサフルオロプロペン、（パーフルオロブチル）エチレン、（パーフルオロヘキシル）エチレン及び（パーフルオロオクチル）エチレンからなる群から選ばれた少なくとも一種であるのがより好ましい。前記リン酸基含有不飽和単量体と前記フッ素基含有オレフィン系不飽和単量体との配合割合はモル比で（前記リン酸基含有不飽和単量体）／（前記フッ素基含有オレフィン系不飽和単量体）＝１／0.05〜１／１であるのが好ましい。 The fluorine group-containing olefinically unsaturated monomer is represented by the following general formula (3):

(Where Rf ₁ is a monovalent organic group containing one or more fluorine groups, and X ₁ , X ₂ and X ₃ are each independently hydrogen or a fluorine group) or the following general formula (4):

(However, Rf ₂ , Rf ₃ and Rf ₄ are each independently a methyl group or a fluorine group in which at least one hydrogen group is substituted with a fluorine group, and X ₄ is a fluorine group, other halogens, or at least one hydrogen group. The group is preferably a methyl group substituted by a fluorine group, an alkoxy group, a fluorine group-containing alkoxy group, an alkyl group or hydrogen. The fluorine group-containing olefinically unsaturated monomer is at least one selected from the group consisting of hexafluoropropene, (perfluorobutyl) ethylene, (perfluorohexyl) ethylene, and (perfluorooctyl) ethylene. More preferred. The mixing ratio of the phosphate group-containing unsaturated monomer and the fluorine group-containing olefinic unsaturated monomer is a molar ratio (the phosphate group-containing unsaturated monomer) / (the fluorine group-containing olefinic system). (Unsaturated monomer) = 1 / 0.05 to 1/1.

（ただしRf₅は１個以上のフッ素基を含有する２価の有機基であり、X₅、X₆、X₇、X₈、X₉及びX₁₀はそれぞれ独立に水素又はフッ素基である。）により表されるものが好ましい。前記フッ素基含有ジエン系不飽和単量体は1,4-ジビニル（パーフルオロブチレン）、1,6-ジビニル（パーフルオロヘキシレン）及び1,8-ジビニル（パーフルオロオクチレン）からなる群から選ばれた少なくとも一種であるのがより好ましい。前記リン酸基含有不飽和単量体と前記フッ素基含有ジエン系不飽和単量体との配合割合はモル比で（前記リン酸基含有不飽和単量体）／（前記フッ素基含有ジエン系不飽和単量体）＝１／0.01〜１／0.2であるのが好ましい。 The fluorine group-containing diene unsaturated monomer is represented by the following general formula (5):

(Where Rf ₅ is a divalent organic group containing 1 or more fluorine _{groups, X 5, X 6, X} 7, X 8, X 9 and X ₁₀ are each independently hydrogen or fluorine group. ) Is preferred. The fluorine-containing diene unsaturated monomer is selected from the group consisting of 1,4-divinyl (perfluorobutylene), 1,6-divinyl (perfluorohexylene) and 1,8-divinyl (perfluorooctylene). More preferably, it is at least one selected. The mixing ratio of the phosphate group-containing unsaturated monomer and the fluorine group-containing diene unsaturated monomer is a molar ratio (the phosphate group-containing unsaturated monomer) / (the fluorine group-containing diene system). It is preferable that the unsaturated monomer) = 1 / 0.01 to 1 / 0.2.

  The fluorine group-containing unsaturated monomer is such that at least one hydrogen group is a fluorine group relative to the fluorine group-containing olefinically unsaturated monomer and / or the fluorine group-containing diene unsaturated monomer. Mixed composition in which a fluorine group-containing (meth) acrylic acid ester (I) having a substituted methyl group or fluorine group at the α-position and / or a fluorine group-containing (meth) acrylic acid having at least one fluorine group is added It can be a thing.

（ただしRf₆は少なくとも１個の水素基がフッ素基により置換されたメチル基又はフッ素基であり、R₇は１個以上のフッ素基を含有する１価の有機基又は１価の炭化水素基である。）により表されるものが好ましい。前記フッ素基含有（メタ）アクリル酸エステル類(I)は、ターシャリーブチル−α−（トリフルオロメチル）アクリレートがより好ましい。 As the fluorine group-containing (meth) acrylic acid esters (I), the following general formula (6):

(However, Rf ₆ is a methyl group or a fluorine group in which at least one hydrogen group is substituted with a fluorine group, and R ₇ is a monovalent organic group or monovalent hydrocarbon group containing one or more fluorine groups. Is preferred. The fluorine group-containing (meth) acrylic acid esters (I) are more preferably tertiary butyl-α- (trifluoromethyl) acrylate.

（ただしRf₇は少なくとも１個の水素基がフッ素基により置換されたメチル基又はフッ素基である。）により表されるものが好ましい。前記フッ素基含有（メタ）アクリル酸類はα−（トリフルオロメチル）アクリル酸がより好ましい。 The fluorine group-containing (meth) acrylic acids are represented by the following general formula (7):

(However, Rf ₇ is preferably a methyl group or a fluorine group in which at least one hydrogen group is substituted with a fluorine group). The fluorine group-containing (meth) acrylic acid is more preferably α- (trifluoromethyl) acrylic acid.

  The first solid polymer electrolyte membrane may also contain other unsaturated monomers having one or more ethylenically unsaturated bonds in the molecule as a copolymerization component.

  When the first solid polymer electrolyte membrane contains the phosphate group-containing unsaturated monomer (I) and the phosphate group-containing unsaturated monomer (II) as a copolymerization component, [the phosphate group The molar ratio of the containing unsaturated monomer (I)] / [the phosphoric acid group containing unsaturated monomer (II)] is preferably 1 / 0.1 to 1/2.

  The second solid polymer electrolyte membrane of the present invention (A) polymerizes a phosphate group-containing unsaturated monomer having one or more phosphate groups and one or more ethylenically unsaturated bonds in the molecule. And (B) fluorine obtained by polymerizing a fluorine group-containing unsaturated monomer having one or more fluorine groups and one or more ethylenically unsaturated bonds in the molecule. The fluorine-containing unsaturated monomer comprises a composition containing a group-containing polymer, and the fluorine-containing unsaturated monomer has (B-1) a fluorine group-containing olefinic unsaturated monomer having one ethylenically unsaturated bond, and (B -2) It contains at least one selected from the group consisting of fluorine group-containing diene unsaturated monomers having two ethylenically unsaturated bonds.

  The second solid polymer electrolyte membrane comprises a laminate including a layer having the phosphoric acid group-containing polymer and a layer having the fluorine group-containing polymer, and the fluorine group-containing polymer layer is the phosphoric acid group. It is preferably formed on at least a part of the surface of the containing polymer layer.

  In the second solid polymer electrolyte membrane, the phosphate group-containing unsaturated monomer may be the phosphate group-containing unsaturated monomer (I) and / or phosphoric acid described in relation to the first solid polymer electrolyte membrane. The group-containing unsaturated monomer (II) is preferred.

  In the second solid polymer electrolyte membrane, the fluorine group-containing olefinic unsaturated monomer and the fluorine group-containing diene unsaturated monomer are the same as those described for the first solid polymer electrolyte membrane, respectively. It can be the same.

  In the second solid polymer electrolyte membrane, the fluorine group-containing unsaturated monomer is based on the fluorine group-containing olefinic unsaturated monomer and / or the fluorine group-containing diene unsaturated monomer, It can be set as the mixed composition which added the fluorine group containing (meth) acrylic acid ester (II) which has at least 1 fluorine group, and / or the said fluorine group containing (meth) acrylic acid.

（ただしR₈は水素、フッ素基、少なくとも１個の水素基がフッ素基により置換されたメチル基又はメチル基であり、R₉は１個以上のフッ素基を含有する１価の有機基又は１価の炭化水素基であり、R₈及び／又はR₉がフッ素基を含有する。）により表されるものが好ましい。前記フッ素基含有（メタ）アクリル酸エステル類(II)は、2,2,2-トリフルオロエチルメタクリレート及び／又はターシャリーブチル−α−（トリフルオロメチル）アクリレートであるのがより好ましい。 The fluorine group-containing (meth) acrylic acid esters (II) are represented by the following general formula (8):

(Wherein R ₈ is hydrogen, a fluorine group, a methyl group or a methyl group in which at least one hydrogen group is substituted with a fluorine group, and R ₉ is a monovalent organic group containing one or more fluorine groups or 1 Is a valent hydrocarbon group, and R ₈ and / or R ₉ contains a fluorine group). The fluorine group-containing (meth) acrylic acid ester (II) is more preferably 2,2,2-trifluoroethyl methacrylate and / or tertiary butyl-α- (trifluoromethyl) acrylate.

  In the second solid polymer electrolyte membrane, the phosphate group-containing polymer is the phosphate group-containing unsaturated monomer (I) and / or the phosphate group-containing unsaturated monomer (II), It may be formed by copolymerization with another unsaturated monomer having one or more ethylenically unsaturated bonds in the molecule.

  In the second solid polymer electrolyte membrane, the phosphate group-containing polymer is obtained by polymerizing the phosphate group-containing unsaturated monomer (I) and the phosphate group-containing unsaturated monomer (II). The molar ratio of [the phosphate group-containing unsaturated monomer (I)] / [the phosphate group-containing unsaturated monomer (II)] is preferably 1 / 0.1 to 1/2. .

  The solid polymer electrolyte composite membrane of the present invention is characterized in that a reinforcing material is further provided to the first or second solid polymer electrolyte membrane.

  The method for producing the second solid polymer electrolyte membrane of the present invention comprises a phosphate group-containing unsaturated monomer having one or more phosphate groups and one or more ethylenically unsaturated bonds in the molecule. (B-1) a fluorine group-containing olefinic unsaturated monomer having one ethylenically unsaturated bond on at least one surface of the obtained phosphoric acid group-containing polymer film, and (B -2) After applying a fluorine group-containing unsaturated monomer containing at least one selected from the group consisting of fluorine-containing diene unsaturated monomers having two ethylenically unsaturated bonds, the fluorine group-containing It is characterized by polymerizing an unsaturated monomer.

  The method for producing the second solid polymer electrolyte composite membrane of the present invention comprises a phosphate group-containing unsaturated monomer having one or more phosphate groups and one or more ethylenically unsaturated bonds in the molecule. Is impregnated into or applied to a reinforcing material, and then the phosphate group-containing unsaturated monomer is polymerized, and (B-1) an ethylenically unsaturated group is formed on at least one surface of the resulting phosphate group-containing polymer composite membrane. At least selected from the group consisting of a fluorine group-containing olefinic unsaturated monomer having one saturated bond, and (B-2) a fluorine group-containing diene unsaturated monomer having two ethylenically unsaturated bonds It is characterized by polymerizing the fluorine group-containing unsaturated monomer after applying a fluorine group-containing unsaturated monomer containing one kind.

  It is preferable that after the solution or dispersion containing the fluorine group-containing unsaturated monomer is applied to the phosphoric acid group-containing polymer (composite) film, the fluorine group-containing unsaturated monomer is polymerized. After adding a photopolymerization initiator to the fluorine group-containing unsaturated monomer, coating the phosphoric acid group-containing polymer (composite) film, covering at least the coated surface with an ultraviolet transparent plate, and irradiating with ultraviolet rays It is preferable to polymerize the fluorine group-containing unsaturated monomer.

  The reinforcing material is preferably made of inorganic or organic fibers or a resin film. The inorganic or organic fiber is preferably woven fabric, non-woven fabric or paper. The resin film is preferably microporous.

  The first and second solid polymer electrolyte (composite) membranes of the present invention are useful for fuel cell applications.

  As described in detail above, the first solid polymer electrolyte (composite) membrane of the present invention is (A) phosphoric acid having one or more phosphate groups and one or more ethylenically unsaturated bonds in the molecule. A copolymer containing a group-containing unsaturated monomer, and (B) a fluorine-group-containing unsaturated monomer having one or more fluorine groups and one or more ethylenically unsaturated bonds in the molecule. The fluorine-containing unsaturated monomer is (B-1) a fluorine-containing olefinically unsaturated monomer having one ethylenically unsaturated bond, and (B-2) two ethylenically unsaturated bonds. Since it has a solid polymer electrolyte containing at least one selected from the group consisting of individual fluorine group-containing diene unsaturated monomers, it exhibits high conductivity and excellent solvent resistance.

  In addition, the second solid polymer electrolyte (composite) membrane of the present invention comprises (A) a phosphate group-containing unsaturated single molecule having one or more phosphate groups and one or more ethylenically unsaturated bonds in the molecule. Polymerized phosphoric acid group-containing polymer obtained by polymerizing a monomer, and (B) a fluorine group-containing unsaturated monomer having one or more fluorine groups and one or more ethylenically unsaturated bonds in the molecule. A fluorine group-containing olefinic unsaturated monomer in which the fluorine group-containing unsaturated monomer has (B-1) one ethylenically unsaturated bond. And (B-2) contains at least one selected from the group consisting of fluorine group-containing diene unsaturated monomers having two ethylenically unsaturated bonds, and thus exhibits high conductivity and solvent resistance. Are better.

The first and second solid polymer electrolyte (composite) membranes of the present invention have excellent proton conductivity with an electrical conductivity of 10 ^−2.5 to 10 ⁻¹ S · cm ⁻¹ , and the temperature of such proton conductivity The dependency is small and the methanol resistance is very good. Therefore, it can be suitably used for electrolytes for primary batteries, electrolytes for secondary batteries, electrolytes for fuel cells, display elements, various sensors, signal transmission media, solid capacitors, ion exchange membranes, and the like. In particular, it is expected to be applied as a solid polymer electrolyte for DMFC (direct methanol fuel cell) for high power applications.

  Hereinafter, the solid polymer electrolyte (composite) membrane of the present invention and the production method thereof will be described in detail.

[1] Solid polymer electrolyte (composite) membrane
(1) First solid polymer electrolyte (composite) membrane The first solid polymer electrolyte (composite) membrane consists of (A) one or more phosphate groups and one or more ethylenically unsaturated bonds in the molecule. And (B) a fluorine group-containing unsaturated monomer having one or more fluorine groups and one or more ethylenically unsaturated bonds in the molecule. The fluorine-containing unsaturated monomer is (B-1) a fluorine-containing olefinically unsaturated monomer having one ethylenically unsaturated bond, and (B-1) B-2) It contains at least one selected from the group consisting of fluorine group-containing diene unsaturated monomers having two ethylenically unsaturated bonds.

(A) Phosphoric acid group-containing unsaturated monomer The phosphoric acid group-containing unsaturated monomer contains a phosphoric acid group having one acidic phosphoric acid group and one ethylenically unsaturated bond in the molecule. The unsaturated monomer (I) and / or the phosphoric acid group-containing unsaturated monomer (II) having one acidic phosphoric acid group and two ethylenically unsaturated bonds in the molecule are preferred.

（ただしR₁は水素又はアルキル基であり、R₂は水素又は置換又は無置換のアルキル基であり、nは1〜6の整数である。）により表されるものが好ましい。 As the phosphate group-containing unsaturated monomer (I), the following general formula (1):

(Wherein R ₁ is hydrogen or an alkyl group, R ₂ is hydrogen or a substituted or unsubstituted alkyl group, and n is an integer of 1 to 6).

（ただしR₃及びR₆はそれぞれ独立に水素又はアルキル基であり、R₄及びR₅はそれぞれ独立に水素又は置換もしくは無置換のアルキル基であり、m及びkはそれぞれ独立に１〜６の整数である。）により表されるものが好ましい。 As the phosphate group-containing unsaturated monomer (II), the following general formula (2):

(However, R ₃ and R ₆ are each independently hydrogen or an alkyl group, R ₄ and R ₅ are each independently hydrogen or a substituted or unsubstituted alkyl group, and m and k are each independently 1-6. It is an integer.

（ただしR₁は水素又はアルキル基であり、R₂は水素又は置換もしくは無置換のアルキル基であり、nは１〜６の整数である。）により表される2-ヒドロキシ（メタ）アクリレートと、五酸化リンとを反応原料としてエステル化反応を行うことにより得られる。 The phosphate group-containing unsaturated monomer (I) represented by the general formula (1) and the phosphate group-containing unsaturated monomer (II) represented by the general formula (2) are Equation (9):

(Wherein R ₁ is hydrogen or an alkyl group, R ₂ is hydrogen or a substituted or unsubstituted alkyl group, and n is an integer of 1 to 6) It can be obtained by carrying out an esterification reaction using phosphorus pentoxide as a reaction raw material.

により表される2-ヒドロキシエチルメタクリレートを用い、リン酸基含有不飽和単量体(I)としてアシッド・ホスホオキシエチルメタクリレート（別名：メタクリロイルオキシエチルホスフェート）を調製し、リン酸基含有不飽和単量体(II)としてジ（メタクリロイルオキシエチル）ホスフェートを調製する例を説明する。 Hereinafter, as 2-hydroxy (meth) acrylate represented by the general formula (9), the following formula (10):

Acid phosphooxyethyl methacrylate (also known as methacryloyloxyethyl phosphate) was prepared as a phosphoric acid group-containing unsaturated monomer (I), and the phosphoric acid group-containing unsaturated monomer An example of preparing di (methacryloyloxyethyl) phosphate as the monomer (II) will be described.

に示すように2-ヒドロキシエチルメタクリレートと五酸化リンを反応させることにより、ジ（メタクリロイルオキシエチル）アシッド・ピロホスフェートを調製し、次いで下記式(12)：

に示すように、ジ（メタクリロイルオキシエチル）アシッド・ピロホスフェートに2-ヒドロキシエチルメタクリレートを反応させることにより得られる。 Acid phosphooxyethyl methacrylate and di (methacryloyloxyethyl) phosphate are represented by, for example, the following formula (11):

Di (methacryloyloxyethyl) acid pyrophosphate is prepared by reacting 2-hydroxyethyl methacrylate and phosphorus pentoxide as shown in the following formula (12):

As shown in the above, it can be obtained by reacting di (methacryloyloxyethyl) acid pyrophosphate with 2-hydroxyethyl methacrylate.

  For obtaining the phosphate group-containing unsaturated monomer (I) represented by the general formula (1) and the phosphate group-containing unsaturated monomer (II) represented by the general formula (2) A known method for producing a phosphate ester by an esterification reaction using an organic hydroxy compound and phosphorus pentoxide as raw materials can be applied to the esterification reaction. For example, phosphorus pentoxide can be added stepwise to 2-hydroxy (meth) acrylate, or the addition rate of phosphorus pentoxide can be appropriately adjusted.

  Tables 1 and 2 show the structural formulas and physical properties of representative ones of the phosphate group-containing unsaturated monomers (I) represented by the general formula (1), 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.

注：(1) Brookfield型粘度計により測定（括弧内はロータNo.を示す）。
(2) 単位は質量％。

Note: (1) Measured with a Brookfield viscometer (the rotor number is shown in parentheses).
(2) The unit is mass%.

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 ^a _4-f (OH) _f (where R ^a is an alkyl group having 1 to 18 carbon atoms, an aromatic group having 6 to 12 carbon atoms, and It represents at least one selected from the group consisting of alicyclic groups having 6 to 12 carbon atoms, and f represents a positive integer of 1 to 3). The phosphate group-containing unsaturated monomer (I) of the general formula (1) may be used alone or in combination of two or more.

  As the phosphoric acid group-containing unsaturated monomer (II), the di (methacryloyloxyethyl) phosphate is preferable. The phosphate group-containing unsaturated monomer (II) may be used alone or in combination of two or more.

  Phosphoric acid group-containing unsaturated monomer (I) has excellent proton conductivity, and phosphoric acid group-containing unsaturated monomer (II) has a crosslinking action and excellent film-forming properties. It is preferred to use both group-containing unsaturated monomers (I) and (II). This improves the balance of proton conductivity, solvent resistance and membrane strength. When both phosphate group-containing unsaturated monomers (I) and (II) are used, [phosphate group-containing unsaturated monomer (I)] / [phosphate group-containing unsaturated monomer (II) ] Is preferably 1 / 0.1 to 1/2.

（ただしR₁₀及びR₁₃はそれぞれ独立に水素又はアルキル基であり、R₁₁及びR₁₂はそれぞれ独立に水素又は置換もしくは無置換のアルキル基であり、t及びw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を共重合成分として含んでもよい。上記式(13)により表されるピロリン酸基含有不飽和単量体は架橋作用を有し、造膜性に優れているので、これを共重合成分として含むことによっても膜強度及び耐溶剤性が向上する。上記式(13)により表されるピロリン酸基含有不飽和単量体としては、ジ（メタクリロイルオキシエチル）アシッド・ピロホスフェートが好ましい。 The first solid polymer electrolyte (composite) membrane has the following general formula (13):

(However, R ₁₀ and R ₁₃ are each independently hydrogen or an alkyl group, R ₁₁ and R ₁₂ are each independently hydrogen or a substituted or unsubstituted alkyl group, and t and w are each independently 1-6. An integer-containing pyrophosphate group-containing unsaturated monomer may be included as a copolymerization component. Since the pyrophosphate group-containing unsaturated monomer represented by the above formula (13) has a crosslinking action and is excellent in film-forming properties, the film strength and solvent resistance can be obtained by including this as a copolymerization component. Will improve. The pyrophosphate group-containing unsaturated monomer represented by the above formula (13) is preferably di (methacryloyloxyethyl) acid pyrophosphate.

に示すように、2-ヒドロキシエチルメタクリレートと五酸化リンを反応させることにより、アシッド・ホスホオキシエチルメタクリレートとジ（メタクリロイルオキシエチル）ホスフェートとジ（メタクリロイルオキシエチル）アシッド・ピロホスフェートとが得られる。 Di (methacryloyloxyethyl) acid pyrophosphate can be prepared, for example, according to the above formula (11). For example, the following formula (14):

As shown in the above, by reacting 2-hydroxyethyl methacrylate with phosphorus pentoxide, acid phosphooxyethyl methacrylate, di (methacryloyloxyethyl) phosphate and di (methacryloyloxyethyl) acid pyrophosphate are obtained.

（ただしR₁₄、R₁₇及びR₁₉はそれぞれ独立に水素又はアルキル基であり、R₁₅、R₁₆及びR₁₈はそれぞれ独立に水素又は置換もしくは無置換のアルキル基であり、p、r及びs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不飽和単量体(III)を共重合成分として含んでもよい。 The first solid polymer electrolyte (composite) membrane is represented by the following general formula (15) as a phosphate group-containing unsaturated monomer:

(However, R ₁₄ , R ₁₇ and R ₁₉ are each independently hydrogen or an alkyl group, R ₁₅ , R ₁₆ and R ₁₈ are each independently hydrogen or a substituted or unsubstituted alkyl group, p, r and s Are each independently an integer of 1 to 6.) A phosphate group-containing unsaturated monomer (III) represented by

(B) Fluorine group-containing unsaturated monomer The first solid polymer electrolyte (composite) membrane comprises (B-1) a fluorine group-containing olefinically unsaturated monomer having one ethylenically unsaturated bond, and (B-2) Since a fluorine-containing unsaturated monomer containing at least one selected from the group consisting of fluorine-containing diene unsaturated monomers having two ethylenically unsaturated bonds is included as a copolymerization component Excellent hydrophobicity.

（ただしRf₁は１個以上のフッ素基を含有する１価の有機基であり、X₁、X₂及びX₃はそれぞれ独立に水素又はフッ素基である。）又は下記一般式(4)：

（ただしRf₂、Rf₃及びRf₄はそれぞれ独立に少なくとも１個の水素基がフッ素基により置換されたメチル基又はフッ素基であり、X₄はフッ素基、その他のハロゲン、少なくとも１個の水素基がフッ素基により置換されたメチル基、アルコキシ基、フッ素基含有アルコキシ基、アルキル基又は水素である。）により表されるものが好ましい。 The fluorine group-containing olefinically unsaturated monomer is represented by the following general formula (3):

(Where Rf ₁ is a monovalent organic group containing one or more fluorine groups, and X ₁ , X ₂ and X ₃ are each independently hydrogen or a fluorine group) or the following general formula (4):

(However, Rf ₂ , Rf ₃ and Rf ₄ are each independently a methyl group or a fluorine group in which at least one hydrogen group is substituted with a fluorine group, and X ₄ is a fluorine group, other halogens, or at least one hydrogen group. The group is preferably a methyl group substituted by a fluorine group, an alkoxy group, a fluorine group-containing alkoxy group, an alkyl group or hydrogen.

The monovalent organic group Rf ₁ containing a fluorine group in the general formula (3) is _one in which 60% or more of the hydrogen groups of the alkyl group having the same carbon number are substituted with fluorine groups. And is more preferably a perfluoroalkyl group. Rf ₁ preferably has 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms. Rf ₁ may be a linear structure or a branched structure, but is preferably a linear structure. Rf ₁ may have a halogen atom other than fluorine. Rf ₁ may have a hetero atom. Examples of the hetero atom include an etheric oxygen atom and a thioetheric sulfur atom contained between carbon-carbon bonds in Rf ₁ .

（但しRf₁は上記式(3)と同じである。）により表されるものが、より好ましい。 As the fluorine group-containing olefinically unsaturated monomer represented by the general formula (3), the following general formula (16):

(Wherein Rf ₁ is the same as the above formula (3)) is more preferable.

  The fluorine group-containing olefinically unsaturated monomer represented by the general formula (16) includes (perfluorobutyl) ethylene, (perfluorohexyl) ethylene, (perfluorooctyl) ethylene, and (perfluorodecyl) ethylene. Etc. Of these, (perfluorobutyl) ethylene, (perfluorohexyl) ethylene and (perfluorooctyl) ethylene are preferable as the fluorine group-containing olefinic unsaturated monomer.

Rf ₂ , Rf ₃ and Rf _{4 in the} general formula (4) are preferably a perfluoromethyl group or a fluorine group. When X ₄ in the general formula (4) is an alkyl group, an alkoxy group, or a fluorine group-containing alkoxy group, the carbon number thereof is preferably 1 to 10. Examples of the fluorine group-containing olefinically unsaturated monomer represented by the general formula (4) include hexafluoropropene, chlorotrifluoroethylene, 1-methoxy- (perfluoro-2-methyl-1-propene) and the like. Can be mentioned.

（ただしRf₅は１個以上のフッ素基を含有する２価の有機基であり、X₅、X₆、X₇、X₈、X₉及びX₁₀はそれぞれ独立に水素又はフッ素基である。）により表されるものが好ましい。 As the fluorine group-containing diene unsaturated monomer, the following general formula (5):

(Where Rf ₅ is a divalent organic group containing 1 or more fluorine _{groups, X 5, X 6, X} 7, X 8, X 9 and X ₁₀ are each independently hydrogen or fluorine group. ) Is preferred.

The general formula (5) divalent organic group Rf ₅ containing one or more fluorine groups in is replaced by 60% or more fluorine groups of the hydrogen groups of the this and alkylene groups of the same number of carbon atoms It is preferable that it is a perfluoroalkylene group. Rf ₅ preferably has 1 to 20 carbon atoms, and more preferably 1 to 10 carbon atoms. Rf ₅ may have a linear structure or a branched structure, but preferably has a linear structure. Rf ₅ may have a halogen atom other than fluorine. Rf ₅ may have a hetero atom and / or a hetero atom group. The hetero atom, carbon in Rf ₅ - etheric oxygen atoms contained in the carbon-carbon bond, and the like thioether sulfur atom. Examples of the hetero atom group include an ester bond.

（但しRf₅は上記式(5)と同じである。）により表されるものが、より好ましい。 Examples of the fluorine group-containing olefinically unsaturated monomer represented by the general formula (5) include the following general formula (17):

(Wherein Rf ₅ is the same as that in the above formula (5)) is more preferable.

  Examples of the fluorine group-containing diene unsaturated monomer represented by the general formula (17) include 1,4-divinyl (perfluorobutylene) (also known as 1,4-divinyloctafluorobutane), 1,6- Divinyl (perfluorohexylene) (alias: 1,6-divinyldodecafluorohexane) and 1,8-divinyl (perfluorooctylene) (alias: 1,8-divinylhexadecafluorooctane) are preferred.

  Of the two types of fluorine group-containing unsaturated monomers, fluorine group-containing diene unsaturated monomers are preferred from the viewpoint of having crosslinkability and capable of forming intermolecular crosslinks in the polymer. From the viewpoint of relatively good compatibility with the phosphate group-containing unsaturated monomer, 1,4-divinyl (perfluorobutylene) is preferred.

  The blending ratio of each of the two fluorine group-containing unsaturated monomers and the phosphate group-containing unsaturated monomer will be described. When a fluorine group-containing olefinic unsaturated monomer is used alone as the fluorine group-containing unsaturated monomer, the molar ratio is (phosphoric acid group-containing unsaturated monomer) / (fluorine group-containing olefinic unsaturated). Monomer) = 1 / 0.05 to 1/1. When a fluorine group-containing diene unsaturated monomer is used alone as the fluorine group-containing unsaturated monomer, the molar ratio is (phosphoric acid group-containing unsaturated monomer) / (fluorine group-containing diene-based unsaturated monomer). Monomer) = 1 / 0.01 to 1 / 0.2.

  A fluorine-group containing unsaturated monomer may be used independently and may use 2 or more types together. When two or more types are used in combination, for example, a fluorine group-containing olefinic unsaturated monomer and / or a fluorine group-containing diene unsaturated monomer, and a methyl group in which at least one hydrogen group is substituted with a fluorine group or The composition etc. which mixed fluorine group containing (meth) acrylic acid ester (I) which has a fluorine group in alpha position, and / or fluorine group containing (meth) acrylic acid which has at least one fluorine group, etc. can be mentioned.

（ただしRf₆は少なくとも１個の水素基がフッ素基により置換されたメチル基又はフッ素基であり、R₇は１個以上のフッ素基を含有する１価の有機基又は１価の炭化水素基である。）により表されるものが好ましい。 As the fluorine group-containing (meth) acrylic acid esters (I) having a methyl group in which at least one hydrogen group is substituted with a fluorine group or a fluorine group at the α-position, the following general formula (6):

(However, Rf ₆ is a methyl group or a fluorine group in which at least one hydrogen group is substituted with a fluorine group, and R ₇ is a monovalent organic group or monovalent hydrocarbon group containing one or more fluorine groups. Is preferred.

In the general formula (6), Rf ₆ is preferably a perfluoromethyl group or a fluorine group. In the general formula (6), the carbon number of R ₇ which is a monovalent organic group or monovalent hydrocarbon group containing a fluorine group is preferably 1 to 10, more preferably 1 to 5. preferable. When R ₇ is a monovalent organic group containing a fluorine group, it is preferable that 60% or more of the hydrogen groups of the alkylene group having the same carbon number as R ₇ are substituted with a fluorine group. . When R ₇ is a monovalent organic group containing a fluorine group and has 2 or more carbon atoms, it is preferable that all of the hydrogen atoms in the terminal methyl group are substituted with fluorine groups. R ₇ may be a linear structure or a branched structure. R ₇ may have a halogen atom other than fluorine. R ₇ may have a hetero atom. Examples of the hetero atom include an etheric oxygen atom and a thioetheric sulfur atom contained between carbon-carbon bonds in R ₇ .

  Fluorine group-containing (meth) acrylic acid esters (I) represented by the general formula (6) include tertiary butyl-α- (trifluoromethyl) acrylate and trifluoroethyl-α- (trifluoromethyl). An acrylate etc. are mentioned. Of these, tertiary butyl-α- (trifluoromethyl) acrylate is preferred as the fluorine group-containing (meth) acrylic acid ester (I).

（ただしRf₇は少なくとも１個の水素基がフッ素基により置換されたメチル基又はフッ素基である。）により表されるものが好ましい。上記一般式(7)においてRf₇はパーフルオロメチル基又はフッ素基であるのがより好ましい。フッ素基含有（メタ）アクリル酸類としては、α−（トリフルオロメチル）アクリル酸が特に好ましい。 As fluorine-containing (meth) acrylic acids, the following general formula (7):

(However, Rf ₇ is preferably a methyl group or a fluorine group in which at least one hydrogen group is substituted with a fluorine group). In the general formula (7), Rf ₇ is more preferably a perfluoromethyl group or a fluorine group. As the fluorine group-containing (meth) acrylic acid, α- (trifluoromethyl) acrylic acid is particularly preferable.

(C) Other unsaturated monomer capable of copolymerization The first solid polymer electrolyte (composite) membrane is copolymerized with a phosphate group-containing unsaturated monomer and / or a fluorine group-containing unsaturated monomer. Other unsaturated monomers that may be used may be included as a copolymerization component. Such other unsaturated monomers can be roughly divided into the following two groups (C-1) and (C-2).

(C-1) Unsaturated monomer containing acidic group An unsaturated monomer containing an acidic group is a compound having at least one acidic group and at least one ethylenically unsaturated bond in the molecule. . Examples of acidic groups include sulfonic acid groups and carboxylic acid groups.

（ただしR₂₀は水素又はメチル基である。）により表される化合物、
下記一般式(19)：

（ただしR₂₁は水素又はメチル基であり、Yは置換もしくは無置換の炭素数１〜６のアルキレン基又は炭素数６〜12のアリーレン基である。）により表される化合物、及び下記一般式(20)：

（ただしR₂₂は水素又はメチル基であり、Zは−O−基又は−NH−基であり、Yは置換もしくは無置換の炭素数１〜６のアルキレン基又は炭素数６〜12のアリーレン基である。）により表される化合物からなる群から選ばれた少なくとも一種が好ましい。 As the sulfonic acid group-containing unsaturated monomer used in the present invention, the following general formula (18):

(Wherein R ₂₀ is hydrogen or a methyl group),
The following general formula (19):

Wherein R ₂₁ is hydrogen or a methyl group, and Y is a substituted or unsubstituted alkylene group having 1 to 6 carbon atoms or an arylene group having 6 to 12 carbon atoms, and the following general formula (20):

(However, R ₂₂ is hydrogen or a methyl group, Z is an —O— group or an —NH— group, and Y is a substituted or unsubstituted alkylene group having 1 to 6 carbon atoms or an arylene group having 6 to 12 carbon atoms. And at least one selected from the group consisting of compounds represented by:

  Illustrative compounds of unsaturated monomers containing sulfonic acid groups include allyl sulfonic acid, methallyl sulfonic acid, vinyl sulfonic acid, p-styrene sulfonic acid, (meth) acrylic acid butyl-4-sulfonic acid, (meta ) Acryloxybenzene sulfonic acid, tertiary butyl acrylamide sulfonic acid, 2-acrylamido-2-methylpropane sulfonic acid and the like. P-styrene sulfonic acid is preferred. However, it is preferable that the amount of allyl sulfonic acid and methallyl sulfonic acid used is small because the allyl group causes degradative chain transfer. Specifically, the amount used is at most about 10% by mass. Illustrative compounds of unsaturated monomers containing carboxylic acid groups include (meth) acrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, maleic anhydride and the like. These may be used alone or in combination of two or more. Preferably, a sulfonic acid group-containing unsaturated monomer is used. Thereby, the electrical conductivity of the solid polymer electrolyte (composite) film is further improved, and the temperature dependence of the electrical conductivity is remarkably reduced.

  The sulfonic acid group and the carboxylic acid group may be dissociated or may form a complex salt. When forming a complex salt, it is preferable to form a complex salt with an ammonium ion or amine residue or alkali metal as described in (A) above for the phosphate group-containing unsaturated monomer.

  The blending ratio of the acidic group-containing unsaturated monomer in the unsaturated monomer composition (phosphate group-containing unsaturated monomer + fluorine group-containing unsaturated monomer + other unsaturated monomer) is: What is necessary is just to set suitably according to the compound used as an acidic group containing unsaturated monomer in the range which does not impair the effect of this invention.

(C-2) Unsaturated monomer containing no acidic group
Other than those described in (C-1), all unsaturated monomers that are not gaseous at normal temperature and have one or more ethylenically unsaturated bonds in the molecule are targeted. Among them, (meth) acrylonitrile; methyl ( (Meth) acrylates such as (meth) acrylate, ethyl (meth) acrylate and alkyl (meth) acrylate; (meth) acrylic acid amides; substituted or unsubstituted styrenes; vinyl chloride, vinyl acetate, N-vinyl Vinyls such as pyrrolidone are preferably used. From the viewpoint of improving heat resistance, acrylonitrile is preferred. Ethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, hexamethylenediol di (meth) acrylate, divinylbenzene, and the like containing a plurality of ethylenically unsaturated bonds in one molecule are also resistant to the copolymer. Used for the purpose of improving chemical properties.

  Mixing ratio of unsaturated monomer not containing acidic group in unsaturated monomer composition (phosphorus group-containing unsaturated monomer + fluorine group-containing unsaturated monomer + other unsaturated monomer) May be appropriately set depending on the compound used as the unsaturated monomer not containing an acidic group, as long as the effects of the present invention are not impaired. For example, when acrylonitrile is used as the unsaturated monomer that does not contain an acidic group, the blending ratio in the unsaturated monomer composition is approximately 50 mol% or less.

(2) Second solid polymer electrolyte (composite) membrane The second solid polymer electrolyte (composite) membrane is composed of (A) one or more phosphate groups and one or more ethylenically unsaturated bonds in the molecule. A phosphoric acid group-containing polymer obtained by polymerizing a phosphoric acid group-containing unsaturated monomer having, and (B) one or more fluorine groups and one or more ethylenically unsaturated bonds in the molecule. It consists of a composition containing a fluorine group-containing polymer obtained by polymerizing a fluorine group-containing unsaturated monomer, and the fluorine group-containing unsaturated monomer has one (B-1) ethylenically unsaturated bond. It contains at least one selected from the group consisting of a fluorine group-containing olefinic unsaturated monomer and (B-2) a fluorine group-containing diene unsaturated monomer having two ethylenically unsaturated bonds. Hereinafter, the second solid polymer electrolyte (composite) membrane will be described in detail.

(A) Phosphate group-containing polymer
(a) Phosphoric acid group-containing unsaturated monomer The phosphoric acid group-containing unsaturated monomer includes the phosphoric acid group-containing unsaturated monomer (I) and / or phosphorus described in (1) (A) above. Acid group-containing unsaturated monomer (II) is preferred. The phosphate group-containing unsaturated monomer (I) may be used alone or in combination of two or more. The same applies to the phosphate group-containing unsaturated monomer (II).

  Phosphoric acid group-containing unsaturated monomer (I) is excellent in proton conductivity, and phosphoric acid group-containing unsaturated monomer (II) has a crosslinking action and has excellent film-forming properties, so that it contains a phosphoric acid group. The polymer is preferably a copolymer of phosphate group-containing unsaturated monomers (I) and (II). This improves the balance of proton conductivity, solvent resistance and membrane strength. When the phosphate group-containing polymer contains phosphate group-containing unsaturated monomers (I) and (II), [phosphate group-containing unsaturated monomer (I)] / [phosphate group-containing unsaturated monomer] The molar ratio of the monomer (II)] is preferably 1 / 0.1 to 1/2.

  The phosphoric acid group-containing polymer is a pyrophosphate group-containing unsaturated monomer represented by the general formula (13) and / or a phosphoric acid group-containing unsaturated monomer represented by the general formula (15) ( III) may be included as a copolymerization component. This further improves the film strength and solvent resistance.

(b) Other unsaturated monomer that can be copolymerized The phosphoric acid group-containing polymer is a copolymerized with another unsaturated monomer that can be copolymerized with a phosphoric acid group-containing unsaturated monomer. May be. Examples of other unsaturated monomers include the same as those described for the first solid polymer electrolyte (composite) membrane in (1) and (C) above, but acrylonitrile is preferred from the viewpoint of improving heat resistance. .

(B) Fluorine group-containing polymer By having a fluorine group-containing polymer phase, hydrophobicity is particularly improved. The fluorine group-containing unsaturated monomer used for the second solid polymer electrolyte (composite) membrane is (i) a fluorine group-containing olefinically unsaturated monomer having one ethylenically unsaturated bond, and (ii) ) It contains at least one selected from the group consisting of fluorine group-containing diene unsaturated monomers having two ethylenically unsaturated bonds.

  Regarding the fluorine group-containing olefinic unsaturated monomer and the fluorine group-containing diene unsaturated monomer, the first solid polymer electrolyte (composite) membrane is described in (1) and (B) above. And the description thereof will be omitted.

  A fluorine-group containing unsaturated monomer may be used independently and may use 2 or more types together. When two or more kinds are used in combination, for example, a fluorine group-containing olefinic unsaturated monomer and / or a fluorine group-containing diene unsaturated monomer and a fluorine group-containing (meth) acrylic acid ester having at least one fluorine group The composition etc. which mixed class (II) and / or the said fluorine-group containing (meth) acrylic acid can be mentioned.

（ただしR₈は水素、フッ素基、少なくとも１個の水素基がフッ素基により置換されたメチル基又はメチル基であり、R₉は１個以上のフッ素基を含有する１価の有機基又は１価の炭化水素基であり、R₈及び／又はR₉がフッ素基を含有する。）により表されるものが好ましい。上記一般式(8)においてR₈はパーフルオロメチル基又はフッ素基であるのが好ましい。上記一般式(8)において、フッ素基を含有する１価の有機基又は１価の炭化水素基であるR₉に関する好ましい要件は、上記一般式(6)中のR₇に関する好ましい要件と同じでよい。 As fluorine group-containing (meth) acrylic acid esters (II), the following general formula (8):

(Wherein R ₈ is hydrogen, a fluorine group, a methyl group or a methyl group in which at least one hydrogen group is substituted with a fluorine group, and R ₉ is a monovalent organic group containing one or more fluorine groups or 1 Is a valent hydrocarbon group, and R ₈ and / or R ₉ contains a fluorine group). In the general formula (8), R ₈ is preferably a perfluoromethyl group or a fluorine group. In the general formula (8), the preferable requirements for R ₉ which is a monovalent organic group or monovalent hydrocarbon group containing a fluorine group are the same as the preferable requirements for R ₇ in the general formula (6). Good.

  Fluorine group-containing (meth) acrylic acid esters (II) represented by the general formula (8) include 2,2,2-trifluoroethyl acrylate, 2,2,2-trifluoroethyl methacrylate, and tertiary. Examples include butyl-α- (trifluoromethyl) acrylate and trifluoroethyl-α- (trifluoromethyl) acrylate. Of these, 2,2,2-trifluoroethyl methacrylate and tertiary butyl-α- (trifluoromethyl) acrylate are preferred as the fluorine group-containing (meth) acrylic acid esters (II).

The second solid polymer electrolyte (composite) film is composed of a laminate including a layer having a phosphate group-containing polymer and a layer having a fluorine group-containing polymer, and the fluorine group-containing polymer layer contains a phosphate group. It is preferably formed on at least a part of the surface of the polymer layer. The second solid polymer electrolyte (composite) film composed of such a laminate usually has 10 g or less of a fluorine group-containing polymer layer per 1 m ^{2 of the} phosphate group-containing polymer layer. However, it is not intended to limit the configuration in which the fluorine group-containing polymer layer is formed only on the surface of the phosphate group-containing polymer layer, and part or all of the fluorine group-containing polymer phase is converted into the phosphate group-containing polymer phase. An included configuration may be used.

(3) Reinforcing Material The first and second solid polymer electrolyte composite membranes include a reinforcing material. The reinforcing materials used in the present invention can be roughly divided into the following three groups.
(i) Reinforcing materials made of inorganic fibers Glass fibers, alumina fibers, rock wool fibers, slag fibers, and the like include woven fabrics, nonwoven fabrics, and papers. The basis weight of the reinforcing material made of inorganic fibers is 10 to 60 mg / cm ² , preferably 10 to 40 mg / cm ² , and the thickness is in the range of 1 μm to 60 μm, preferably 5 μm to 40 μm.

(ii) Reinforcing materials made of organic fibers Usually, nylon fibers, polyester fibers, acrylic fibers, etc. used for clothing, and woven fabrics, nonwoven fabrics, papers, etc. made of aramid fibers used for industrial use are listed. Examples of the nonwoven fabric include polypropylene nonwoven fabric. However, since the temperature of the composite system may rise to ˜100 ° C. during ultraviolet irradiation, it is necessary to have heat resistance that can withstand it. The basis weight and thickness of the reinforcing material made of organic fibers are the same as in the case of (i). However, when the unsaturated monomer composition to be impregnated contains an unsaturated monomer having a strong acid group such as a sulfonic acid group, woven fabric, nonwoven fabric, paper, etc. made of nylon fiber are not suitable because of weak acid resistance. .

(iii) Resin film General-purpose resin such as polyethylene resin, polypropylene resin, poly-3-methylpentene resin, nylon-6 resin, polyester resin, thermoplastic polyurethane resin, etc., heat-resistant resin such as polysulfone resin, polyethersulfone resin, A film formed from a polyether ether ketone resin, an aramid resin, a polyimide resin, a fluorine resin, or the like is preferable. The resin film may be a film having micropores or a film having no micropores, but the former is preferable. However, when the unsaturated monomer composition to be impregnated contains an unsaturated monomer having a strong acid group such as a sulfonic acid group, the nylon film is not suitable because the acid resistance is not strong.

  In the case of a microporous film, the pore size of the micropore is preferably as small as possible, and is preferably a submicron diameter. Further, the overall open area ratio is preferably as large as possible, and particularly preferably 40 to 50% (surface area). The thickness of the resin film is preferably 1 μm to 40 μm, and more preferably 5 μm to 25 μm.

  The use ratio of the reinforcing material and the unsaturated monomer composition varies greatly depending on the affinity of the reinforcing material to the unsaturated monomer composition, in other words, the absorbability of the unsaturated monomer composition. And reinforcing material / unsaturated monomer composition = 1/20 to 1/2 (mass ratio).

(4) Other polymers that can be mixed The film-forming properties when producing a solid polymer electrolyte (composite) membrane, and the strength, hydrophobicity, solvent resistance, etc. of the obtained solid polymer electrolyte (composite) membrane are further increased. In order to improve, other polymers that can be compatible with the (co) polymer included in the solid polymer electrolyte (composite) membrane of the present invention can be mixed.

  Examples of other polymers compatible with the solid polymer electrolyte of the present invention include polyamide resin, polyvinyl alcohol, polyacrylamide, polyacrylic acid, melamine resin, cellulose and modified products thereof. The polyamide resin has an effect of improving the film forming property when producing a solid polymer electrolyte (composite) film, and the strength, hydrophobicity, solvent resistance, and the like of the obtained solid polymer electrolyte (composite) film. Polyvinyl alcohol has the effect of improving the electrical conductivity of the solid polymer electrolyte (composite) film. When producing a solid polymer electrolyte (composite) membrane using polyvinyl alcohol, it is preferable to add a polyamide resin or a melamine resin in order not to reduce the hydrophobicity. When using polyvinyl alcohol, the degree of polymerization, the melting point, the degree of saponification, etc. are appropriately taken into consideration and the one selected as necessary.

  The polyamide resin used for this invention will not be specifically limited if it has the solubility with respect to a solvent. The molecular weight of the polyamide resin is preferably 1,000 to 1,000,000, more preferably 2,000 to 500,000, and even more preferably 5,000 to 150,000.

（ただし一般式(21)において、R₂₃〜R₂₅は置換または無置換のアルキレン基を表し、R₂₆は置換または無置換のアルキル基を表し、yとzは重合比を表し、10≦y≦50、50≦z≦90であって、yとzとの和は100である。）により表されるN-アルコキシアルキル化ナイロンが挙げられる。 As a polyamide resin that can be preferably used in the present invention, the following general formula (21):

(In the general formula (21), R _{23 to} R ₂₅ represent a substituted or unsubstituted alkylene group, R ₂₆ represents a substituted or unsubstituted alkyl group, y and z represent a polymerization ratio, and 10 ≦ y ≦ 50, 50 ≦ z ≦ 90, and the sum of y and z is 100.)

In the general formula (21), R ₂₃ and R ₂₄ each independently represent a substituted or unsubstituted alkylene group having 3 to 20 carbon atoms. Examples of the substituent include an alkyl group having 1 to 6 carbon atoms and halogen. R ₂₃ and R ₂₄ are preferably an unsubstituted alkylene group having 5 to 11 carbon atoms, and more preferably n-pentylene.

R ₂₅ represents a substituted or unsubstituted alkylene group having 1 to 6 carbon atoms. The substituent may be the same as R ₂₃ and R ₂₄ . Preferred R ₂₅ is methylene.

R ₂₆ represents a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms. Substituents may be the same as those described for R ₂₃ and R ₂₄ . Preferred R ₂₆ is methyl.

  y and z represent the polymerization ratio, and the sum of y and z is 100. 10 ≦ y ≦ 50 and 50 ≦ z ≦ 90 are preferable, and 20 ≦ y ≦ 30 and 70 ≦ z ≦ 80 are more preferable. If y is less than 10, the solubility in a solvent decreases, which is not preferable. Also, it is difficult to increase y to more than 50 due to steric hindrance of the substituent.

  Specific examples of the N-alkoxyalkylated nylon of the general formula (21) include those obtained by alkoxymethylating nylon-6, nylon-66, nylon-12, copolymer nylon, etc., preferably nylon-6 Or N-methoxymethylated nylons of nylon-66. Examples of the products include Toresin F30K, Toresin MF-30, and Toresin EF-30T manufactured and sold by Nagase ChemteX Corporation.

  The blending ratio of the polyamide resin in the solid polymer electrolyte (composite) membrane of the present invention is such that the proportion of the polyamide resin in the polymer component contained in the solid polymer electrolyte (composite) membrane is 50% by mass or less (based on solid content mass). Preferably there is. If the proportion exceeds 50% by mass, the conductivity becomes insufficient.

(5) Characteristics The first and second solid polymer electrolyte (composite) membranes have excellent proton conductivity with a conductivity of 10 ^−2.5 to 10 ⁻¹ S · cm ⁻¹ . Temperature dependency is small. Here, conductivity is obtained by analyzing the complex impedance method of data obtained by plane complex impedance analysis, and obtaining the result from the resistance value of the sample obtained by cole-cole plot graphic processing. It is. The first and second solid polymer electrolyte (composite) membranes have a methanol extraction rate of 19% or less, and are excellent in methanol resistance. Here, the methanol extraction rate is a value obtained by measuring a decrease in mass after immersing a solid polymer electrolyte (composite) membrane in a large excess of methanol at room temperature for 24 hours.

  The thickness of the phosphoric acid group-containing polymer (composite) film is usually 300 μm or less, preferably 10 to 100 μm, more preferably 10 to 30 μm.

[2] Method for producing solid polymer electrolyte (composite) membrane
(1) Method for producing first solid polymer electrolyte (composite) membrane The first solid polymer electrolyte membrane is a phosphate group-containing unsaturated monomer described in [1] (1) (A) above. [1] A composition containing a fluorine group-containing unsaturated monomer and a photopolymerization initiator (photosensitizer) described in (1) (B) is a material (fluorine-based material) to which the unsaturated monomer does not adhere. It can be produced by casting onto a plate coated with a polymer, etc., covering with a UV transparent plate, and then irradiating with UV rays to copolymerize unsaturated monomers. When other unsaturated monomers described in the above [1] (1) (C) are also used, they are added to the composition. When other polymers described in [1] and (4) above are also mixed, they are added to the above composition (the same applies hereinafter).

  The first solid polymer electrolyte composite membrane having the first solid polymer electrolyte membrane provided with the reinforcing material is impregnated with the same composition as that of the first solid polymer electrolyte membrane. After the coating, the reinforcing material can be sandwiched between ultraviolet transmissive support substrates, and irradiated with ultraviolet rays to photopolymerize the unsaturated monomer.

  The ultraviolet transmissive plate and the support substrate used for the ultraviolet irradiation polymerization of the unsaturated monomer composition not only have a high ultraviolet transmittance, but also have heat resistance that can withstand the temperature rise during polymerization due to ultraviolet irradiation, and It is necessary that the unsaturated monomer composition and the solid polymer electrolyte obtained by polymerizing the unsaturated monomer composition are not bonded to each other and have good peelability.

  The glass plate normally used as the support substrate is very good in terms of ultraviolet transmittance and heat resistance, but is in close contact with the solid polymer electrolyte obtained by copolymerization of the unsaturated monomer used in the present invention. It is preferable to apply a silicone-based or fluorine-based release agent on the surface of the film or attach a fluororesin-based thin transparent film.

  In addition to glass flat plates, the supporting substrate has good UV transmittance such as polyperfluorovinyl ether resin (PFA) and polyvinylidene fluoride resin (PVDF), as well as poly-3-methylpentene resin and polypropylene resin. A resin flat plate having heat resistance of 100 ° C. or higher can be used.

After casting the unsaturated monomer composition, it is covered with an ultraviolet transmissive plate and irradiated with ultraviolet light, or the reinforcing material impregnated with or coated with the unsaturated monomer composition is placed between two supporting substrates. In performing ultraviolet irradiation while sandwiching, it is necessary to squeeze out air and excess unsaturated monomer composition out of the system. For example, when using a reinforcing material, as shown in FIG. 1, it is preferable to irradiate ultraviolet rays while maintaining a horizontal state in a state in which pressure is evenly applied between two supporting substrates and stopped with a clip or a clamp. . Irradiation is performed for at least one side for 1 to 15 minutes. When irradiation is performed alternately on the front and back sides, it is performed for 1 to 15 minutes on one side. The ultraviolet irradiation intensity at the time of photopolymerization is 5 to 100 μW / cm ² , preferably 10 to 80 μW / cm ² . The ultraviolet irradiation distance is appropriately set so as to be sufficiently cured within the above irradiation time range.

As a photopolymerization initiator (photosensitizer) added to the unsaturated monomer composition,
(i) adjacent polyketone compounds represented by R— (CO) _x —R ′ (R, R ′ = hydrogen or hydrocarbon group, x = 2 to 3) (for example, diacetyl, dibenzyl, etc.),
(ii) α-carbonyl alcohols represented by R—CO—CHOH—R ′ (R, R ′ = hydrogen or hydrocarbon group) (for example, benzoin),
(iii) acyloin ethers represented by R—CH (OR ″) — CO—R ′ (R, R ′, R ″ = hydrocarbon group) (for example, benzoin methyl ether),
(iv) α-substituted acyloins represented by Ar—CR (OH) —CO—Ar (Ar = aryl group, R = hydrocarbon group) (for example, α-alkylbenzoin), and
(v) There are polynuclear quinones (for example, 9,10-anthraquinone, etc.).
These photopolymerization initiators can be used alone or in combination.

  The usage-amount of a photoinitiator is the range of 0.01-3 mass% with respect to the total mass of an unsaturated monomer, Preferably it is the range of 0.01-1.5 mass%. If it is less than 0.01% by mass, polymerization is not completed within a predetermined ultraviolet irradiation time, and unreacted monomers remain. This is not preferable, and if it exceeds 3% by mass, the degree of polymerization of the resulting polymer is lowered. This is not preferable because the polymer tends to be colored.

  In the present invention, the purpose of assisting the dissolution of the photopolymerization initiator in the unsaturated monomer composition, the viscosity of the unsaturated monomer composition is lowered, the impregnation into the reinforcing material is facilitated, For the purpose of reducing the amount of adhesion and reducing the thickness of the composite film, a low boiling point solvent such as methanol can be added as a diluent.

(2) Method for Producing Second Solid Polymer Electrolyte (Composite) Membrane The method for producing the second solid polymer electrolyte (composite) membrane includes a (composite) membrane containing a phosphate group-containing polymer [phosphate group Containing polymer (composite) film] and then applying a fluorine group-containing unsaturated monomer and then polymerizing it.
(A) Formation of phosphoric acid group-containing polymer film In the case of the second solid polymer electrolyte membrane, the phosphoric acid group-containing unsaturated monomer and photopolymerization initiator described in [1], (2) and (A) above Is cast on a plate coated with a material (such as a fluororesin) to which an unsaturated monomer does not adhere, covered with an ultraviolet transparent plate, and then irradiated with ultraviolet rays to be unsaturated monomer. Is polymerized to form a phosphate group-containing polymer film. When other unsaturated monomers described in the above [1] (1) (C) are also used, they are added to the composition.

  In the case of the second solid polymer electrolyte composite membrane having the second solid polymer electrolyte membrane provided with the reinforcing material, the reinforcing material is impregnated with the same composition as that of the second solid polymer electrolyte membrane. After the coating, a reinforcing material is sandwiched between ultraviolet transmissive support substrates, and the unsaturated monomer is photopolymerized by irradiating with ultraviolet rays to form a phosphate group-containing polymer composite film.

  The ultraviolet irradiation intensity and irradiation time during photopolymerization are the same as those in the case of the first solid polymer electrolyte (composite) film described in (1) above. The photopolymerization initiator used is the same as that for producing the first solid polymer electrolyte (composite) membrane described in (1) above, and the amount used relative to the unsaturated monomer is 0.01 to 3% by mass. The range is preferably 0.01 to 1.5% by mass.

  The thickness of the phosphoric acid group-containing polymer film is 300 μm or less, preferably 10 to 100 μm, more preferably 10 to 30 μm.

(B) Formation of Fluorine Group-Containing Polymer Phase The phosphoric acid group-containing polymer (composite) film obtained in (A) above is converted into the fluorine group-containing unsaturated monolayer described in [1] (2) (B) After immersing in a solution or dispersion containing a monomer or applying a solution or dispersion containing such a fluorine group-containing unsaturated monomer to at least one surface of the phosphoric acid group-containing polymer film, A fluorine group-containing polymer phase can be formed by sandwiching the support substrate and irradiating ultraviolet rays to photopolymerize the fluorine group-containing unsaturated monomer.

  What is necessary is just to set suitably the density | concentration of the solution or dispersion liquid containing a fluorine group containing unsaturated monomer according to a desired dilution degree. The solvent is not particularly limited as long as the fluorine group-containing unsaturated monomer is dissolved or dispersed, but with respect to the fluorine group-containing olefin unsaturated monomer and the fluorine group-containing diene unsaturated monomer. It is preferable to use n-hexane, aliphatic hydrocarbon solvent, aromatic hydrocarbon solvent, etc. For fluorine group-containing (meth) acrylic acid esters and fluorine group-containing (meth) acrylic acids, for example, It is preferable to use n-hexane, ester solvents (such as ethyl acetate), ketone solvents (such as methyl ethyl ketone) and the like. As such a solvent, as a matter of course, those which dissolve the phosphate group-containing polymer described in the above (A) should be avoided. The immersion is usually preferably performed at room temperature, and the immersion time is preferably 1 to 60 minutes.

  The ultraviolet irradiation intensity and the irradiation time during photopolymerization are the same as in the case of forming a phosphate group-containing polymer (composite) film. The photopolymerization initiator used is the same as that for forming a phosphate group-containing polymer (composite) film, and the amount used relative to the fluorine group-containing unsaturated monomer is in the range of 0.01 to 3% by mass, preferably It is the range of 0.01-1.5 mass%. The photopolymerization initiator is preferably added in advance to a solution or dispersion of the fluorine group-containing unsaturated monomer.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these.

注：(1) Phosmer M： メタクリロイルオキシエチルホスフェート（分子量：210）。
(2) 組成物A：メタクリロイルオキシエチルホスフェートとジ（メタクリロイルオキシエチル）ホスフェート（分子量：322）とを理論モル比１：１で含有する組成物。 Table 3 shows the raw materials of the phosphate group-containing unsaturated monomers used in Examples 1 to 11 and Comparative Example 1, and their blending ratios.

Notes: (1) Phosmer M: methacryloyloxyethyl phosphate (molecular weight: 210).
(2) Composition A: A composition containing methacryloyloxyethyl phosphate and di (methacryloyloxyethyl) phosphate (molecular weight: 322) in a theoretical molar ratio of 1: 1.

  In Tables 4 to 7 below, the blending ratio of methacryloyloxyethyl phosphate (MOEP) and di (methacryloyloxyethyl) phosphate (DMOEP) is as follows: Phosmer M (MOEP) and Composition A [MOEP / DMOEP = 1 / 1 (theoretical molar ratio)].

Examples 1 and 2
(1) Production of Phosphate Group-Containing Polymer Composite Film The raw materials of the phosphate group-containing unsaturated monomers used and their blending ratios are as shown in Table 3. The phosphoric acid group-containing polymer composite film was prepared by adjusting the viscosity of the monomer composition shown in Table 3 using methanol as a diluent, and then using [Irgacure 651 (2,2-dimethoxy- 1,2-diphenylethane-1-one) + Irgacure 500 (1-hydroxycyclohexyl phenyl ketone, benzophenone) = 1 (mass%) + 0.5 (mass%)] (vs. total monomers) After adopting various non-woven fabrics as a reinforcing material and impregnating or adhering the monomer composition, as shown in FIG. 1 and FIG. 2, it is sandwiched between two glass flat plates with a fluororesin film attached, Using a mercury lamp (Cure Arab HLR1000F-22 manufactured by Sen Special Light Source Co., Ltd.), each was irradiated for 70 seconds from the front and back (irradiation distance: 15 cm) at an ultraviolet irradiation intensity of 37 μW / cm ² (irradiation distance: 15 cm) and photopolymerized. Table 4 shows the types and thicknesses of the reinforcing materials used.

(2) Formation of fluorine-containing polymer layer (Perfluorohexyl) A 76.7% by mass n-hexane solution of ethylene (distributor: Daikin Chemicals Sales Co., Ltd., product number: F-1620) was prepared. The phosphate group-containing polymer composite film prepared in (1) was immersed for 1 minute at room temperature. Next, photopolymerization was performed in the same manner as in the case of the phosphoric acid group-containing polymer composite film described in (1) above, to produce a solid polymer electrolyte composite film. Table 4 shows the methanol extraction rate and the like of the produced solid polymer electrolyte composite membrane.

注：(1) メタクリロイルオキシエチルホスフェート（分子量：210）。
(2) ジ（メタクリロイルオキシエチル）ホスフェート（分子量：322）。
(3) アクリロニトリル（分子量：53）。
(4) 重合体／補強材の質量比。
(5) リン酸基含有重合体（複合）膜にフッ素基含有重合体層を形成した後の質量増加を測定し、固体高分子電解質（複合）膜の単位面積当りに換算した。
(6) 複合膜を大過剰のメタノールに室温で24時間浸漬した後の質量減少を測定。
(7) GF（ガラスファイバー）不織布。
(8) PP（ポリプロピレン）不織布。
(9) （パーフルオロヘキシル）エチレン（分子量：346.09）

Notes: (1) Methacryloyloxyethyl phosphate (molecular weight: 210).
(2) Di (methacryloyloxyethyl) phosphate (molecular weight: 322).
(3) Acrylonitrile (molecular weight: 53).
(4) Polymer / reinforcement mass ratio.
(5) The mass increase after the fluorine group-containing polymer layer was formed on the phosphoric acid group-containing polymer (composite) film was measured and converted to a unit area of the solid polymer electrolyte (composite) film.
(6) Measure the mass loss after immersing the composite membrane in a large excess of methanol at room temperature for 24 hours.
(7) GF (glass fiber) nonwoven fabric.
(8) PP (polypropylene) nonwoven fabric.
(9) (Perfluorohexyl) ethylene (Molecular weight: 346.09)

Examples 3-5
(1) Production of Phosphate Group-Containing Polymer Film The raw materials of the phosphoric acid group-containing unsaturated monomer used and their blending ratio are as shown in Table 3. The phosphoric acid group-containing polymer film uses the monomer composition shown in Table 5 and is irradiated for 6 minutes only from one side with an ultraviolet irradiation intensity of 16 μW / cm ² without using a reinforcing material (irradiation distance: 25). cm) It was produced in the same manner as in Example 1 except that it was photopolymerized.

(2) Formation of fluorine group-containing polymer layer Prepare n-hexane solutions of (perfluorohexyl) ethylene (distributor: Daikin Chemicals Sales Co., Ltd., product number: F-1620) with each concentration shown in Table 5. The phosphoric acid group-containing polymer film prepared in (1) was immersed in this at room temperature. Next, photopolymerization was carried out in the same manner as in the case of the phosphoric acid group-containing polymer film described in (1) above to produce a solid polymer electrolyte membrane. Table 5 shows the methanol extraction rate and the like of the produced solid polymer electrolyte membrane.

注：(1) メタクリロイルオキシエチルホスフェート（分子量：210）。
(2) ジ（メタクリロイルオキシエチル）ホスフェート（分子量：322）。
(3) アクリロニトリル（分子量：53）。
(4) 膜を大過剰のメタノールに室温で24時間浸漬した後の質量減少を測定。
(5) （パーフルオロヘキシル）エチレン（分子量：346.09）

Notes: (1) Methacryloyloxyethyl phosphate (molecular weight: 210).
(2) Di (methacryloyloxyethyl) phosphate (molecular weight: 322).
(3) Acrylonitrile (molecular weight: 53).
(4) The mass loss after the membrane was immersed in a large excess of methanol at room temperature for 24 hours was measured.
(5) (Perfluorohexyl) ethylene (Molecular weight: 346.09)

Examples 6-8
Table 3 shows the raw materials of the phosphate group-containing unsaturated monomers used and the blending ratios thereof. Phosphoric group-containing unsaturated monomers and fluorine group-containing unsaturated monomers listed in Table 6 (1,4-divinyloctafluorobutane, distributor: Daikin Chemicals Sales Co., Ltd., product number: F-9445) Photopolymerization was carried out in the same manner as in Example 1 except that a monomer composition consisting of the above was used, no reinforcing material was used, and ultraviolet irradiation intensity was 16 μW / cm ² and irradiation was performed for 5 minutes only from one side (irradiation distance: 25 cm). The solid polymer electrolyte membrane was prepared. Table 6 shows the methanol extraction rate and the like of the produced solid polymer electrolyte membrane.

注：(1) メタクリロイルオキシエチルホスフェート（分子量：210）。
(2) ジ（メタクリロイルオキシエチル）ホスフェート（分子量：322）。
(3) 1,4-ジビニルオクタフルオロブタン（分子量：254.12）。
(4) 膜を大過剰のメタノールに室温で24時間浸漬した後の質量減少を測定。

Notes: (1) Methacryloyloxyethyl phosphate (molecular weight: 210).
(2) Di (methacryloyloxyethyl) phosphate (molecular weight: 322).
(3) 1,4-divinyloctafluorobutane (molecular weight: 254.12).
(4) The mass loss after the membrane was immersed in a large excess of methanol at room temperature for 24 hours was measured.

Comparative Example 1
Table 3 shows the raw materials of the phosphate group-containing unsaturated monomers used and the blending ratios thereof. A phosphate group-containing polymer composite film was produced in the same manner as in Example 2 except that the fluorine group-containing unsaturated monomer was not applied. Table 7 shows the methanol extraction rate and the like of the produced solid polymer electrolyte composite membrane.

注：(1) メタクリロイルオキシエチルホスフェート（分子量：210）。
(2) ジ（メタクリロイルオキシエチル）ホスフェート（分子量：322）。
(3) アクリロニトリル（分子量：53）。
(4) 重合体／補強材の質量比。
(5) 複合膜を大過剰のメタノールに室温で24時間浸漬した後の質量減少を測定。
(6) PP（ポリプロピレン）不織布。

Notes: (1) Methacryloyloxyethyl phosphate (molecular weight: 210).
(2) Di (methacryloyloxyethyl) phosphate (molecular weight: 322).
(3) Acrylonitrile (molecular weight: 53).
(4) Polymer / reinforcement mass ratio.
(5) Measure the mass loss after immersing the composite membrane in a large excess of methanol at room temperature for 24 hours.
(6) PP (polypropylene) nonwoven fabric.

  From the results shown in Tables 4 to 7, it can be seen that the (composite) membranes of Examples 1 to 8 have a methanol extraction rate of 19% or less and can make a composite membrane having high methanol resistance. On the other hand, since the composite film of Comparative Example 1 does not contain a fluorine group-containing unsaturated monomer as a copolymer component and does not contain a fluorine group-containing polymer phase, the methanol resistance is poor. The thickness of the solid polymer electrolyte composite membrane of the example is in the range of 170 to 300 μm, but the thickness of the reinforcing material, the affinity between the reinforcing material and the monomer composition, the adhesion ratio of the polymer, in other words, For example, a desired thickness can be obtained by appropriately adjusting the adhesion amount of the monomer composition and the pressure at which the monomer composition is squeezed out.

(Evaluation of proton conductivity)
Proton conductivity was measured using the complex impedance method. A 13 mmφ circular sample cut out from the (composite) films of Examples 1 to 8 and Comparative Example 1 produced by the above-described method was sandwiched between two platinum electrodes, and an impedance analyzer manufactured by Japan Hewlett-Packard Company. An HP4192A cell was filled. The cell impedance was measured at a measurement frequency range of 0.05 to 13 kHz, an applied voltage of 12 mV, a relative humidity of 90%, and a measurement temperature range of 30 to 80 ° C. The obtained data was subjected to plane complex impedance analysis, and the conductivity was obtained from the resistance value of the sample obtained by performing the cole-cole plot graphic processing on the result. The results are shown in FIGS.

From the results shown in FIGS. 3 to 6, the conductivity of the solid polymer electrolyte composite membrane of the present invention is on the order of 10 ^−2.5 to 10 ⁻¹ S · cm ⁻¹ , and a polymer having a phosphate group as a functional group. It can be seen that the electrolyte is at a good level and the temperature dependence of conductivity is small. On the other hand, since the composite film of Comparative Example 1 does not contain a fluorine group-containing unsaturated monomer as a copolymer component and does not contain a fluorine group-containing polymer phase, the conductivity is poor.

It is a side view which shows the state which pinched | interposed the solid polymer electrolyte composite film between two glass flat plates. It is a top view which shows the state which pinched | interposed the solid polymer electrolyte composite film between two glass flat plates. 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 composite film of Example 1,2. 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 3-5. 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. 5 is a graph showing the relationship between temperature T (° C.) and conductivity log (σ / S · cm ⁻¹ ) with respect to the solid polymer electrolyte membrane of Comparative Example 1 using a cole-cole plot.

Explanation of symbols

1. Solid polymer electrolyte composite membrane
11 ... Solid polymer electrolyte
12 ... Reinforcing material 2 ... Glass flat plate 3 ... Clip

Claims (43)

(A) a phosphate group-containing unsaturated monomer having one or more phosphate groups and one or more ethylenically unsaturated bonds in the molecule; and
(B) A solid polymer electrolyte membrane obtained by copolymerizing a fluorine group-containing unsaturated monomer having one or more fluorine groups and one or more ethylenically unsaturated bonds in the molecule, The group-containing unsaturated monomer is (B-1) a fluorine group-containing olefinic unsaturated monomer having one ethylenically unsaturated bond, and (B-2) a fluorine having two ethylenically unsaturated bonds. A solid polymer electrolyte membrane comprising at least one selected from the group consisting of group-containing diene unsaturated monomers. 2. The solid polymer electrolyte membrane according to claim 1, wherein the phosphate group-containing unsaturated monomer includes a phosphate group having one acidic phosphate group and one ethylenically unsaturated bond in a molecule. Containing unsaturated monomer (I) and / or phosphate group-containing unsaturated monomer (II) having one acidic phosphate group and two ethylenically unsaturated bonds in the molecule A solid polymer electrolyte membrane. The solid polymer electrolyte membrane according to claim 2, wherein the phosphate group-containing unsaturated monomer (I) is represented by the following general formula (1):

(Wherein R ₁ is hydrogen or an alkyl group, R ₂ is hydrogen or a substituted or unsubstituted alkyl group, and n is an integer of 1 to 6). Electrolyte membrane. The solid polymer electrolyte membrane according to claim 3, wherein R ₁ is H or CH ₃ and R ₂ is H, CH ₃ or CH ₂ Cl. The solid polymer electrolyte membrane according to claim 3 or 4, wherein the phosphate group of the phosphate group-containing unsaturated monomer (I) forms an amine salt or an ammonium salt. Molecular electrolyte membrane. The solid polymer electrolyte membrane according to any one of claims 2 to 5, wherein the phosphate group-containing unsaturated monomer (II) is represented by the following general formula (2):

(However, R ₃ and R ₆ are each independently hydrogen or an alkyl group, R ₄ and R ₅ are each independently hydrogen or a substituted or unsubstituted alkyl group, and m and k are each independently 1-6. It is an integer.) A solid polymer electrolyte membrane characterized by The solid polymer electrolyte membrane according to claim 6, wherein R ₃ and R ₆ are each independently H or CH ₃ , and R ₄ and R ₅ are each independently H, CH ₃ or CH ₂ Cl. A solid polymer electrolyte membrane. The solid polymer electrolyte membrane according to any one of claims 1 to 7, wherein the fluorine group-containing olefinic unsaturated monomer is represented by the following general formula (3):

(Where Rf ₁ is a monovalent organic group containing one or more fluorine groups, and X ₁ , X ₂ and X ₃ are each independently hydrogen or a fluorine group) or the following general formula (4):

(However, Rf ₂ , Rf ₃ and Rf ₄ are each independently a methyl group or a fluorine group in which at least one hydrogen group is substituted with a fluorine group, and X ₄ is a fluorine group, other halogens, or at least one hydrogen group. The group is a methyl group substituted by a fluorine group, an alkoxy group, a fluorine group-containing alkoxy group, an alkyl group or hydrogen.) The fluorine group-containing diene unsaturated monomer is represented by the following general formula (5): :

(Where Rf ₅ is a divalent organic group containing 1 or more fluorine _{groups, X 5, X 6, X} 7, X 8, X 9 and X ₁₀ are each independently hydrogen or fluorine group. A solid polymer electrolyte membrane characterized by the following: 9. The polymer electrolyte membrane according to claim 1, wherein the fluorine group-containing olefinically unsaturated monomer is hexafluoropropene, (perfluorobutyl) ethylene, (perfluorohexyl) ethylene, and ( Perfluorooctyl) at least one selected from the group consisting of ethylene, and the fluorine group-containing diene unsaturated monomer is 1,4-divinyl (perfluorobutylene), 1,6-divinyl (perfluorohexylene) ) And 1,8-divinyl (perfluorooctylene). A solid polymer electrolyte membrane characterized in that it is at least one selected from the group consisting of 1,8-divinyl (perfluorooctylene). The solid polymer electrolyte membrane according to any one of claims 1 to 9, wherein a blending ratio of the phosphate group-containing unsaturated monomer and the fluorine group-containing olefinic unsaturated monomer is a molar ratio (the above Phosphate group-containing unsaturated monomer) / (the fluorine group-containing olefinically unsaturated monomer) = 1 / 0.05 to 1/1, the phosphate group-containing unsaturated monomer and the fluorine group-containing The blending ratio with the diene unsaturated monomer is a molar ratio (the phosphate group-containing unsaturated monomer) / (the fluorine group-containing diene unsaturated monomer) = 1 / 0.01 to 1 / 0.2. A solid polymer electrolyte membrane characterized by being. 11. The solid polymer electrolyte membrane according to claim 1, wherein the fluorine group-containing unsaturated monomer is the fluorine group-containing olefinic unsaturated monomer and / or the fluorine group-containing diene-based unsaturated monomer. Fluorine group-containing (meth) acrylic acid ester (I) having a methyl group in which at least one hydrogen group is substituted with a fluorine group or a fluorine group at the α-position and / or at least one with respect to the saturated monomer A solid polymer electrolyte membrane, which is a mixed composition to which a fluorine group-containing (meth) acrylic acid having a fluorine group is added. 12. The solid polymer electrolyte membrane according to claim 11, wherein the fluorine group-containing (meth) acrylic acid ester (I) is represented by the following general formula (6):

(However, Rf ₆ is a methyl group or a fluorine group in which at least one hydrogen group is substituted with a fluorine group, and R ₇ is a monovalent organic group or monovalent hydrocarbon group containing one or more fluorine groups. The fluorine group-containing (meth) acrylic acid is represented by the following general formula (7):

(Wherein Rf ₇ is a methyl group or a fluorine group in which at least one hydrogen group is substituted with a fluorine group). 13. The polymer electrolyte membrane according to claim 11 or 12, wherein the fluorine group-containing (meth) acrylic acid ester (I) is tertiary butyl-α- (trifluoromethyl) acrylate, and the fluorine group-containing ( A solid polymer electrolyte membrane, wherein the (meth) acrylic acid is α- (trifluoromethyl) acrylic acid. The solid polymer electrolyte membrane according to any one of claims 1 to 13, wherein the unsaturated polymer further includes one or more unsaturated monomers having one or more ethylenically unsaturated bonds in the molecule. Solid polymer electrolyte membrane. The solid polymer electrolyte membrane according to any one of claims 2 to 14, wherein the phosphate group-containing unsaturated monomer (I) and the phosphate group-containing unsaturated monomer (II) are copolymerized components. And the molar ratio of [the phosphate group-containing unsaturated monomer (I)] / [the phosphate group-containing unsaturated monomer (II)] is from 1 / 0.1 to 1/2. Solid polymer electrolyte membrane. (A) a phosphate group-containing polymer obtained by polymerizing a phosphate group-containing unsaturated monomer having one or more phosphate groups and one or more ethylenically unsaturated bonds in the molecule; and
(B) a composition comprising a fluorine group-containing polymer obtained by polymerizing a fluorine group-containing unsaturated monomer having one or more fluorine groups and one or more ethylenically unsaturated bonds in the molecule; The fluorine group-containing unsaturated monomer is (B-1) a fluorine group-containing olefinic unsaturated monomer having one ethylenically unsaturated bond, and (B-2) two ethylenically unsaturated bonds. A solid polymer electrolyte membrane comprising at least one selected from the group consisting of a fluorine group-containing diene unsaturated monomer. 17. The solid polymer electrolyte membrane according to claim 16, comprising a laminate including the layer having the phosphate group-containing polymer and the layer having the fluorine group-containing polymer, wherein the fluorine group-containing polymer layer is the A solid polymer electrolyte membrane formed on at least a part of the surface of a phosphate group-containing polymer layer. 18. The solid polymer electrolyte membrane according to claim 16 or 17, wherein the phosphate group-containing unsaturated monomer is a phosphorus group having one acidic phosphate group and one ethylenically unsaturated bond in the molecule. Acid group-containing unsaturated monomer (I) and / or phosphate group-containing unsaturated monomer (II) having one acidic phosphate group and two ethylenically unsaturated bonds in the molecule A solid polymer electrolyte membrane characterized by being. 19. The solid polymer electrolyte membrane according to claim 18, wherein the phosphate group-containing unsaturated monomer (I) is represented by the following general formula (1):

(Wherein R ₁ is hydrogen or an alkyl group, R ₂ is hydrogen or a substituted or unsubstituted alkyl group, and n is an integer of 1 to 6). Electrolyte membrane. 20. The solid polymer electrolyte membrane according to claim 19, wherein R ₁ is H or CH ₃ and R ₂ is H, CH ₃ or CH ₂ Cl. The solid polymer electrolyte membrane according to claim 19 or 20, wherein the phosphate group of the phosphate group-containing unsaturated monomer (I) forms an amine salt or an ammonium salt. Molecular electrolyte membrane. The solid polymer electrolyte membrane according to any one of claims 18 to 21, wherein the phosphate group-containing unsaturated monomer (II) is represented by the following general formula (2):

(However, R ₃ and R ₆ are each independently hydrogen or an alkyl group, R ₄ and R ₅ are each independently hydrogen or a substituted or unsubstituted alkyl group, and m and k are each independently 1-6. It is an integer.) A solid polymer electrolyte membrane characterized by The solid polymer electrolyte membrane according to claim 22, wherein R ₃ and R ₆ are each independently H or CH ₃ , and R ₄ and R ₅ are each independently H, CH ₃ or CH ₂ Cl. A solid polymer electrolyte membrane. 24. The solid polymer electrolyte membrane according to claim 16, wherein the fluorine group-containing olefinically unsaturated monomer is represented by the following general formula (3):

(Where Rf ₁ is a monovalent organic group containing one or more fluorine groups, and X ₁ , X ₂ and X ₃ are each independently hydrogen or a fluorine group) or the following general formula (4):

(However, Rf ₂ , Rf ₃ and Rf ₄ are each independently a methyl group or a fluorine group in which at least one hydrogen group is substituted with a fluorine group, and X ₄ is a fluorine group, other halogens, or at least one hydrogen group. The group is a methyl group substituted by a fluorine group, an alkoxy group, a fluorine group-containing alkoxy group, an alkyl group or hydrogen.) The fluorine group-containing diene unsaturated monomer is represented by the following general formula (5): :

(Where Rf ₅ is a divalent organic group containing 1 or more fluorine _{groups, X 5, X 6, X} 7, X 8, X 9 and X ₁₀ are each independently hydrogen or fluorine group. A solid polymer electrolyte membrane characterized by the following: 25. The solid polymer electrolyte membrane according to claim 16, wherein the fluorine group-containing olefinic unsaturated monomer is hexafluoropropene, (perfluorobutyl) ethylene, (perfluorohexyl) ethylene and ( Perfluorooctyl) at least one selected from the group consisting of ethylene, and the fluorine group-containing diene unsaturated monomer is 1,4-divinyl (perfluorobutylene), 1,6-divinyl (perfluorohexylene) ) And 1,8-divinyl (perfluorooctylene). A solid polymer electrolyte membrane characterized in that it is at least one selected from the group consisting of 1,8-divinyl (perfluorooctylene). 26. The solid polymer electrolyte membrane according to claim 16, wherein the fluorine group-containing unsaturated monomer is the fluorine group-containing olefinically unsaturated monomer and / or the fluorine group-containing diene-based unsaturated monomer. Fluorine group-containing (meth) acrylic acid ester (II) having at least one fluorine group and / or fluorine group-containing (meth) acrylic acid having at least one fluorine group was added to the saturated monomer. A solid polymer electrolyte membrane which is a mixed composition. 27. The solid polymer electrolyte membrane according to claim 26, wherein the fluorine group-containing (meth) acrylic acid esters (II) are represented by the following general formula (8):

(Wherein R ₈ is hydrogen, a fluorine group, a methyl group or a methyl group in which at least one hydrogen group is substituted with a fluorine group, and R ₉ is a monovalent organic group containing one or more fluorine groups or 1 The fluorine group-containing (meth) acrylic acids are represented by the following general formula (7): R ₈ and / or R ₉ contains a fluorine group.

(Wherein Rf ₇ is a methyl group or a fluorine group in which at least one hydrogen group is substituted with a fluorine group). 28. The polymer electrolyte membrane according to claim 26 or 27, wherein the fluorine group-containing (meth) acrylic acid esters (II) are 2,2,2-trifluoroethyl methacrylate and / or tertiary butyl-α-. A solid polymer electrolyte membrane which is (trifluoromethyl) acrylate, and wherein the fluorine group-containing (meth) acrylic acid is α- (trifluoromethyl) acrylic acid. 29. The solid polymer electrolyte membrane according to claim 18, wherein the phosphate group-containing polymer is the phosphate group-containing unsaturated monomer (I) and / or the phosphate group-containing unsaturated. A solid polymer electrolyte membrane obtained by copolymerizing a monomer (II) with another unsaturated monomer having one or more ethylenically unsaturated bonds in the molecule. The solid polymer electrolyte membrane according to any one of claims 18 to 29, wherein the phosphate group-containing polymer comprises the phosphate group-containing unsaturated monomer (I) and the phosphate group-containing unsaturated monomer. Body (II) as a polymerization component, and the molar ratio of [the phosphate group-containing unsaturated monomer (I)] / [the phosphate group-containing unsaturated monomer (II)] is from 1 / 0.1 to A solid polymer electrolyte membrane characterized by being 1/2. 31. The method for producing a solid polymer electrolyte membrane according to any one of claims 16 to 30, wherein the phosphoric acid group-containing non-phosphorous group having one or more phosphate groups and one or more ethylenically unsaturated bonds in the molecule. Polymerization after casting a saturated monomer, and (B-1) a fluorine group-containing olefinic unsaturated monomer having one ethylenically unsaturated bond on at least one surface of the obtained phosphoric acid group-containing polymer film And (B-2) after applying a fluorine group-containing unsaturated monomer containing at least one selected from the group consisting of fluorine group-containing diene unsaturated monomers having two ethylenically unsaturated bonds And polymerizing the fluorine-containing unsaturated monomer. 32. The method for producing a solid polymer electrolyte membrane according to claim 31, wherein after applying a solution or dispersion containing the fluorine group-containing unsaturated monomer to the phosphate group-containing polymer membrane, the fluorine group A method comprising polymerizing a contained unsaturated monomer. In the method for producing a solid polymer electrolyte membrane according to claim 31 or 32, after adding a photopolymerization initiator to the fluorine group-containing unsaturated monomer, it is applied to the phosphate group-containing polymer membrane, A method comprising polymerizing the fluorine-containing unsaturated monomer by covering at least the coated surface with an ultraviolet ray transmissive plate and irradiating with ultraviolet rays. 31. A solid polymer electrolyte composite membrane comprising the solid polymer electrolyte membrane according to claim 1 and further comprising a reinforcing material. 35. The solid polymer electrolyte composite membrane according to claim 34, wherein the reinforcing material is made of inorganic or organic fibers. 36. The solid polymer electrolyte composite membrane according to claim 35, wherein the reinforcing material is a woven fabric, a nonwoven fabric or paper. 35. The solid polymer electrolyte composite membrane according to claim 34, wherein the reinforcing material is a resin film. 38. The solid polymer electrolyte composite membrane according to claim 37, wherein the resin film is microporous. 39. A method for producing a solid polymer electrolyte composite membrane according to any one of claims 34 to 38, comprising a phosphate group having one or more phosphate groups and one or more ethylenically unsaturated bonds in the molecule. After impregnating or applying the unsaturated monomer to the reinforcing material, the phosphoric acid group-containing unsaturated monomer is polymerized, and on at least one surface of the obtained phosphoric acid group-containing polymer composite membrane, (B- 1) Fluorine group-containing olefinic unsaturated monomer having one ethylenically unsaturated bond, and (B-2) Fluorine group-containing diene unsaturated monomer having two ethylenically unsaturated bonds A method comprising polymerizing the fluorine group-containing unsaturated monomer after applying a fluorine group-containing unsaturated monomer containing at least one selected from the group consisting of: 40. In the method for producing a solid polymer electrolyte composite membrane according to claim 39, after applying a solution or dispersion containing the fluorine group-containing unsaturated monomer to the phosphate group-containing polymer composite membrane, A method comprising polymerizing a fluorine group-containing unsaturated monomer. The method for producing a solid polymer electrolyte composite membrane according to claim 39 or 40, wherein a photopolymerization initiator is added to the fluorine group-containing unsaturated monomer, and then applied to the phosphate group-containing polymer composite membrane. Then, at least the coated surface is covered with an ultraviolet transmissive plate, and the fluorine group-containing unsaturated monomer is polymerized by irradiating with ultraviolet rays. A fuel cell using the solid polymer electrolyte membrane according to any one of claims 1 to 30. A fuel cell using the solid polymer electrolyte composite membrane according to any one of claims 34 to 38.

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