JP2010018795A - Polymer with oxo carbon group - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compound for efficiently producing a polymer electrolyte in which a main chain includes an aliphatic group and an oxo carbon group is directly combined with the main chain, a polymer using the compound, and a polymer electrolyte using the polymer. <P>SOLUTION: The polymer has a repeating unit expressed by formula (1) obtained by addition polymerization of a compound expressed by formula (1'), wherein, both X<SP>1</SP>and X<SP>2</SP>are preferably -O-, and Z is preferably -C(O)- (carbonyl group), and the polymer is used in the polymer electrolyte. The polymer electrolyte can be conveniently used for manufacturing a member for a fuel cell. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a novel polymer having an oxocarbon group.

  Oxocarbons such as squaric acid (square acid) are known to have high acidity because the hydrogen dissociated state in the oxocarbon group has a stable structure due to resonance (for example, Non-Patent Document 1, Non-patent Document 1, Patent Document 2). The inventor has proposed that a polymer having such an oxocarbon group as an ion exchange group is excellent in water resistance and proton conductivity (see Patent Document 1).

JP 2006-225624 A

Oxocarbons, p. 45 (Edited by Robert West), Academic Press (1980), (ISBN: 0-12-744580-3). Journal of the American Chemical Society, 95, 8703 (1973)

  The object of the present invention is to efficiently produce a polymer electrolyte in which the main chain is an aliphatic chain and an oxocarbon group is directly bonded to the main chain (hereinafter referred to as “oxocarbon group-containing polymer electrolyte”). An object of the present invention is to provide a compound that can be used, a polymer that uses the compound, and an oxocarbon group-containing polymer electrolyte that uses the polymer.

（式中、Ｘ¹、Ｘ²はそれぞれ独立に、−Ｏ−、−Ｓ−又は−ＮＲ−を表し、Ｚは−Ｃ（Ｏ）−、−Ｃ（Ｓ）−、−Ｃ（ＮＲ’）−、置換基を有していてもよいアルキレン基又は置換基を有していてもよいアリーレン基を表す（−ＮＲ−、ＮＲ’におけるＲ、Ｒ’は、それぞれ独立に、水素原子、置換基を有していてもよい炭素数１〜６のアルキル基又は置換基を有していてもよい炭素数６〜１０のアリール基を表す。）。ｎは０〜１０の整数を表わす。ｎが２以上である場合、複数あるＺは互いに同じであっても、異なっていてもよい。Ｑ¹、Ｑ²及びＱ³は、それぞれ独立に水素原子、置換基を有していてもよい炭素数１〜６のアルキル基、置換基を有していてもよい炭素数６〜１０のアリール基、又はハロゲン原子を表す。Ｂ^'は１価の有機基を表す。）
＜２＞前記式（１’）において、Ｚが−Ｃ（Ｏ）−、−Ｃ（Ｓ）−及び−Ｃ（ＮＨ）−から選ばれる、＜１＞の化合物。
＜３＞前記式（１’）において、Ｘ¹及びＸ²がともに−Ｏ−であり、Ｚが−Ｃ（Ｏ）−であり、ｎが０〜２の整数である、＜１＞の化合物。
＜４＞＜１＞〜＜３＞のいずれかの化合物をモノマーとして用い、該モノマーを付加重合して得られる高分子。 That is, the present invention provides <4> polymers comprising the following compounds <1> to <3> and compounds selected from these.
<1> A compound represented by the following formula (1 ′).

(In the formula, X ¹ and X ² each independently represent —O—, —S— or —NR—, and Z represents —C (O) —, —C (S) —, —C (NR ′)). -Represents an alkylene group which may have a substituent or an arylene group which may have a substituent (R and R 'in -NR- and NR' each independently represents a hydrogen atom, a substituent, An alkyl group having 1 to 6 carbon atoms which may have a substituent or an aryl group having 6 to 10 carbon atoms which may have a substituent.) N represents an integer of 0 to 10. n is an integer. When it is 2 or more, a plurality of Z may be the same or different from each other, and Q ¹ , Q ² and Q ³ are each independently a hydrogen atom or a carbon number which may have a substituent. 1-6 alkyl group, .B representing an aryl group, or a halogen atom carbon atoms 6 to 10 which may have a substituent ^"is a monovalent organic A representative.)
<2> The compound of <1>, wherein in the formula (1 ′), Z is selected from —C (O) —, —C (S) —, and —C (NH) —.
<3> The compound of <1>, wherein in the formula (1 ′), X ¹ and X ² are both —O—, Z is —C (O) —, and n is an integer of 0 to 2. .
<4> A polymer obtained by using any compound of <1> to <3> as a monomer and addition polymerization of the monomer.

（式中、Ｘ¹、Ｘ²はそれぞれ独立に、−Ｏ−、−Ｓ−又は−ＮＲ−を表し、Ｚは−Ｃ（Ｏ）−、−Ｃ（Ｓ）−、−Ｃ（ＮＲ’）−、置換基を有していてもよいアルキレン基又は置換基を有していてもよいアリーレン基を表す（−ＮＲ−、ＮＲ’におけるＲ、Ｒ’は、それぞれ独立に、水素原子、置換基を有していてもよい炭素数１〜６のアルキル基又は置換基を有していてもよい炭素数６〜１０のアリール基を表す。）。ｎは０〜１０の整数を表わす。ｎが２以上である場合、複数あるＺは互いに同じであっても、異なっていてもよい。Ｑ¹、Ｑ²及びＱ³は、それぞれ独立に水素原子、置換基を有していてもよい炭素数１〜６のアルキル基、置換基を有していてもよい炭素数６〜１０のアリール基、又はハロゲン原子を表す。Ｂ^'は１価の有機基を表す。）
＜６＞前記式（１）において、Ｚが−Ｃ（Ｏ）−、−Ｃ（Ｓ）−及び−Ｃ（ＮＨ）−から選ばれる、＜５＞の高分子。
＜７＞前記式（１）において、Ｘ¹及びＸ²がともに−Ｏ−であり、Ｚが−Ｃ（Ｏ）−であり、ｎが０〜２の整数である、＜５＞の高分子。
＜８＞＜５＞〜＜７＞のいずれかに記載の高分子にある式（１）で表される繰り返し単位の少なくとも一部を、以下の式（２）で表される繰り返し単位に転換してなる、高分子。

（式中、Ｂは水素原子又は金属原子を表す。Ｂが金属原子である場合、他の置換基と結合していてもよい。その他の符号である、Ｘ¹、Ｘ²、Ｚ、ｎ、Ｑ¹、Ｑ²及びＱ³は前記と同じである。）
The present invention also provides the following <5> to <8> derived from any of the compounds <1> to <3>.
<5> A polymer having a repeating unit represented by the following formula (1).

(Wherein, in X ^1, X ² are each independently, -O -, - represents S- or -NR-, Z is -C (O) -, - C (S) -, - C (NR ') -Represents an alkylene group which may have a substituent or an arylene group which may have a substituent (R and R 'in -NR- and NR' each independently represents a hydrogen atom, a substituent, An alkyl group having 1 to 6 carbon atoms which may have a substituent or an aryl group having 6 to 10 carbon atoms which may have a substituent.) N represents an integer of 0 to 10. n is an integer. When it is 2 or more, a plurality of Z may be the same or different from each other, and Q ¹ , Q ² and Q ³ are each independently a hydrogen atom or a carbon number which may have a substituent. 1-6 alkyl group, .B representing an aryl group, or a halogen atom carbon atoms 6 to 10 which may have a substituent ^"is a monovalent organic A representative.)
<6> The polymer according to <5>, wherein in the formula (1), Z is selected from -C (O)-, -C (S)-, and -C (NH)-.
<7> The polymer according to <5>, wherein in formula (1), X ¹ and X ² are both —O—, Z is —C (O) —, and n is an integer of 0 to 2. .
<8> Convert at least a part of the repeating unit represented by the formula (1) in the polymer according to any one of <5> to <7> into the repeating unit represented by the following formula (2). A polymer.

(In the formula, B represents a hydrogen atom or a metal atom. When B is a metal atom, it may be bonded to other substituents. Other symbols are X ¹ , X ² , Z, n, Q ¹ , Q ² and Q ³ are the same as above.)

The polymer in any one of the above items <5> to <8> has a strongly acidic group called an oxocarbon group, and is a polymer electrolyte, particularly a polymer electrolyte fuel cell (hereinafter referred to as “fuel cell” in some cases). ). Therefore, the present invention provides the following <9> to <13>.
<9> A polymer electrolyte containing the polymer <8> as an active ingredient.
<10> A polymer electrolyte membrane comprising the polymer electrolyte of <9>.
<11> A catalyst composition comprising the polymer electrolyte of <9> and a catalyst component.
<12> A polymer-electrolyte according to <9>, a polymer electrolyte membrane according to <10>, or a catalyst layer using the catalyst composition according to <11>, a membrane-electrode assembly.
<13> A polymer electrolyte fuel cell comprising the membrane-electrode assembly according to <12>.

  According to the present invention, an oxocarbon group-containing polymer electrolyte useful for a polymer electrolyte used for, for example, a material for a proton conductive membrane of a fuel cell can be easily obtained. In particular, a polymer electrolyte having an oxocarbon group is expected to be superior in chemical stability, water resistance and the like as compared with a conventional polymer electrolyte having a sulfonic acid group as an ion exchange group. This is advantageous in obtaining a simple fuel cell and is particularly useful industrially.

  Hereinafter, the present invention will be described in detail.

（式中、Ｘ¹、Ｘ²はそれぞれ独立に、−Ｏ−、−Ｓ−又は−ＮＲ−を表し、Ｚは−Ｃ（Ｏ）−、−Ｃ（Ｓ）−、−Ｃ（ＮＲ’）−、置換基を有していてもよいアルキレン基又は置換基を有していてもよいアリーレン基を表す（−ＮＲ−、ＮＲ’におけるＲ、Ｒ’は、それぞれ独立に、水素原子、置換基を有していてもよい炭素数１〜６のアルキル基又は置換基を有していてもよい炭素数６〜１０のアリール基を表す。）。ｎは０〜１０の整数を表わす。ｎが２以上である場合、複数あるＺは互いに同じであっても、異なっていてもよい。Ｑ¹、Ｑ²及びＱ³は、それぞれ独立に水素原子、置換基を有していてもよい炭素数１〜６のアルキル基、置換基を有していてもよい炭素数６〜１０のアリール基、又はハロゲン原子を表す。Ｂ^'は１価の有機基を表す。） First, the present invention provides a compound of the following formula (1 ′), which is a useful monomer for easily and efficiently producing an oxocarbon group-containing polymer electrolyte.

(In the formula, X ¹ and X ² each independently represent —O—, —S— or —NR—, and Z represents —C (O) —, —C (S) —, —C (NR ′)). -Represents an alkylene group which may have a substituent or an arylene group which may have a substituent (R and R 'in -NR- and NR' each independently represents a hydrogen atom, a substituent, An alkyl group having 1 to 6 carbon atoms which may have a substituent or an aryl group having 6 to 10 carbon atoms which may have a substituent.) N represents an integer of 0 to 10. n is an integer. When it is 2 or more, a plurality of Z may be the same or different from each other, and Q ¹ , Q ² and Q ³ are each independently a hydrogen atom or a carbon number which may have a substituent. 1-6 alkyl group, .B representing an aryl group, or a halogen atom carbon atoms 6 to 10 which may have a substituent ^"is a monovalent organic A representative.)

Here, X ¹ and X ² each independently represent —O—, —S—, or —NR—. Preferred are —O— and —S—, more preferred is —O—, and both X ¹ and X ² are particularly preferably —O—. R in NR has 1 to 6 carbon atoms which may have a substituent represented by a hydrogen atom, methyl group, trifluoromethyl group, ethyl group, propyl group, isopropyl group, n-butyl group and the like. An alkyl group, or an aryl group having 6 to 10 carbon atoms which may have a substituent represented by a phenyl group, a pentafluorophenyl group, a naphthyl group, or the like.
Z may have -C (O)-(carbonyl group), -C (S)-(thiocarbonyl group), -C (NR ')-(imino group or substituted imino group) or a substituent. A good alkylene group or an arylene group which may have a substituent is represented. R ′ in NR ′ has the same meaning as R, and examples thereof are the same as R.
Typical examples of the alkylene group which may have a substituent include methylene, fluoromethylene, difluoromethylene, phenylmethylene, diphenylmethylene and the like. Representative examples of the arylene group which may have a substituent include a phenylene group, a naphthylene group, a tetrafluorophenylene group, and the like.
Z is preferably a group selected from -C (O)-, -C (S)-and -C (NR ')-, more preferably from -C (O)-and -C (S)-. A group to be selected, particularly preferably —C (O) —.
n is the number of repetitions of Z and represents an integer of 0 to 10. n is preferably 0 to 4, more preferably 0 to 2, and particularly preferably 1.
Q ¹ , Q ² and Q ³ (hereinafter sometimes referred to as “Q ^{1 to} Q ³ ”) are each independently a hydrogen atom, a methyl group, a trifluoromethyl group, an ethyl group, a propyl group, or an isopropyl group. And having a substituent represented by an alkyl group having 1 to 6 carbon atoms, a phenyl group, a pentafluorophenyl group, a naphthyl group or the like, which may have a substituent represented by an n-butyl group or the like. An aryl group having 6 to 10 carbon atoms or a halogen atom may be used. Q ^{1 to} Q ³ are preferably a hydrogen atom, a methyl group, a trifluoromethyl group, or a halogen atom, more preferably a hydrogen atom or a halogen atom, and particularly preferably a hydrogen atom. Examples of the halogen atom include a chlorine atom and a fluorine atom.
B ′ represents a monovalent organic group. Examples of the monovalent organic group include an alkyl group and an aryl group. The alkyl group is preferably an alkyl group having 1 to 8 carbon atoms, such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, pentyl group, neopentyl group, hexyl group, heptyl group, octyl group and the like. Can be mentioned. Examples of the aryl group include a phenyl group, a naphthyl group, and a biphenyl group.

上式中、Ｂは水素原子又は金属原子を表し、Ｂが金属原子である場合、他の置換基と結合していてもよい。例えば、Ｂが金属原子である場合、複数のオキソカーボン基における−Ｘ^１−で示される基と結合していてもよい。その他の符号である、Ｘ¹、Ｘ²、Ｚ、ｎ、Ｑ¹、Ｑ²及びＱ³は前記と同じである。 Functional groups in the compound represented by the formula (1), i.e., the group represented by the following formula (10) is a ion-exchange group by a -X ¹ -B 'to -X ¹ -B. The ion exchange group is represented by the following formula (20), and such an ion exchange group is referred to as an oxocarbon group in the present invention.

In the above formula, B represents a hydrogen atom or a metal atom, and when B is a metal atom, it may be bonded to another substituent. For example, when B is a metal atom, it may be bonded to a group represented by —X ¹ — in a plurality of oxocarbon groups. The other symbols X ¹ , X ² , Z, n, Q ¹ , Q ² and Q ³ are the same as described above.

で表わされる平衡反応をとりうる。この平衡反応の極限構造は下記式

のように表わされ、プロトンが解離した時のカチオンが分子内に広く非局在化するために安定な構造となる。そのために式（２０）で表される基は酸性度が高い酸性基になるものと考えられる。 In the oxocarbon group represented by the formula (20), when B is a hydrogen atom (in the form of a free acid),

The equilibrium reaction represented by can be taken. The ultimate structure of this equilibrium reaction is

The cation when the proton is dissociated is widely delocalized in the molecule, so that a stable structure is obtained. Therefore, the group represented by the formula (20) is considered to be an acidic group having a high acidity.

等が挙げられる（Ｂは前記と同義である）。なお、上記（１ａ）〜（１ｒ）においてＢは、既述の通り水素原子又は金属原子を表す。 Representative examples of such preferred oxocarbon groups include

(B is as defined above). In the above (1a) to (1r), B represents a hydrogen atom or a metal atom as described above.

Among these, as the ion exchange group of the oxocarbon group-containing polymer electrolyte of the present invention, (1a) to (1d) are preferable. More preferred are (1a) to (1c), even more preferred are (1b) and (1c), and particularly preferred is (1b).
When the oxocarbon group-containing polymer electrolyte obtained in the present invention is used as a member for a fuel cell, from the viewpoint of power generation performance, B is an oxocarbon group of a hydrogen atom, that is, an oxocarbon group in the form of a free acid. Is preferred.
In addition, when B is a metal atom, a metal atom bonded to one equivalent per equivalent of an oxocarbon group is preferable, and specific examples include a lithium atom, a sodium atom, and a potassium atom.

（式中、Ｑ¹〜Ｑ³、Ｂ’は前記式（１’）と同義である。） The compound represented by the formula (1 ′) (hereinafter referred to as “compound (1 ′) compound”) is a polymer useful for obtaining an oxocarbon group-containing polymer electrolyte by addition polymerization or the like (precursor polymer). Here, a compound represented by the following formula (1 ″) that can produce a particularly suitable oxocarbon-containing polymer electrolyte having the oxocarbon group of (1b) above is taken as an example, and the formula (1 ′) A method for producing the compound will be described.

(In formula, Q < ¹ > -Q < ³ >, B 'is synonymous with the said Formula (1').)

(Monomer Synthesis Method 1)
The compound of formula (1 ″) is produced by a method in which alkenyl lithium and 3,4-dialkoxy-3-cyclobutene-1,2-dione are reacted in an inert gas and further treated under acidic conditions. be able to. For such a production method, for example, the method described on pages 2482 and 2477 of Journal of Organic Chemistry, 53, (1988) may be referred to.
Examples of alkenyl lithium include vinyl lithium and isopropenyl lithium.

  As the solvent for the reaction, a solvent that does not react with alkenyl lithium is selected. Examples of such solvents include ether solvents such as tetrahydrofuran, 1,3-dioxolane, 1,4-dioxane, 1,3-dioxane, tetrahydropyran, dibutyl ether, tert-butyl methyl ether, and diphenyl ether. it can. Preferred are cyclic ethers such as tetrahydrofuran, 1,3-dioxolane, 1,4-dioxane, 1,3-dioxane and tetrahydropyran, more preferred are tetrahydrofuran and 1,3-dioxolane, and particularly preferred is tetrahydrofuran. . Further, an ether solvent and an aliphatic hydrocarbon solvent and / or an aromatic hydrocarbon solvent can be mixed and used. Examples of the aliphatic solvent include cyclohexane, hexane, and heptane, and examples of the aromatic hydrocarbon solvent include benzene, toluene, and xylene.

  The temperature at the time of reacting alkenyl lithium with 3,4-dialkoxy-3-cyclobutene-1,2-dione is usually -150 ° C to 20 ° C, preferably -120 ° C to 0 ° C, more preferably -100. ° C to -20 ° C. The concentration of 3,4-dialkoxy-3-cyclobutene-1,2-dione in the reaction solution when reacting alkenyllithium with 3,4-dialkoxy-3-cyclobutene-1,2-dione is usually 0.8. 01 to 50 wt%, preferably 0.02 to 30 wt%, more preferably 0.1 to 20 wt%, more preferably 0.2 to 10 wt%, and particularly preferably 0.5 to 5 wt%. The reaction time for reacting alkenyl lithium with 3,4-dialkoxy-3-cyclobutene-1,2-dione is usually 1 minute to 10 hours, preferably 2 minutes to 5 hours, more preferably 5 minutes to 4 hours, particularly preferably 10 minutes to 3 hours.

  Examples of 3,4-dialkoxy-3-cyclobutene-1,2-dione used here include 3,4-dimethoxy-3-cyclobutene-1,2-dione, 3,4-diethoxy-3-cyclobutene- 1,2-dione, 3,4-di (n-propoxy) -3-cyclobutene-1,2-dione, 3,4-diisopropoxy-3-cyclobutene-1,2-dione, 3,4-dione (N-butoxy) -3-cyclobutene-1,2-dione, 3,4-di (sec-butoxy) -3-cyclobutene-1,2-dione and the like can be mentioned. Among these, 3,4-dimethoxy-3-cyclobutene-1,2-dione, 3,4-diethoxy-3-cyclobutene-1,2-dione, 3,4-diisopropoxy-3-cyclobutene-1 , 2-dione, 3,4-di (n-butoxy) -3-cyclobutene-1,2-dione are preferred.

オキソカーボン基含有高分子電解質を製造し得る前駆体高分子を得るためのモノマーとして使用する場合、式（１’’’）化合物よりも、式（１’’）化合物の方が有利であり、式（１’’’）化合物の生成を抑制するようにして酸処理を実施することが好ましい。なお、酸処理に係る処理時間としては通常１分〜１時間であり、好ましくは２分〜３０分であり、特に好ましくは３分〜１０分である。処理時間が長すぎると、式（１’’’）化合物が生成しやすくなる。したがって、式（１’’’）化合物の生成を制御するためには、酸処理に係る温度と処理時間は重要な因子となる。
アルケニルリチウムと３，４−ジアルコキシ−３−シクロブテン−１，２−ジオンとの反応及びその後の酸処理によって製造される式（１’’）化合物は、各種公知の精製手段により精製することが好ましい。当該精製手段としては、カラムクロマトグラフィー、蒸留、再結晶などの一般的な精製方法を用いることができる。 After reacting alkenyllithium with 3,4-dialkoxy-3-cyclobutene-1,2-dione, the compound (1 ″) is obtained by acid treatment under mild conditions. For such acid treatment, an acid selected from hydrochloric acid, sulfuric acid, nitric acid, acetic acid, trifluoroacetic acid, formic acid and oxalic acid or a mixture of two or more acids selected from these can be used. The temperature for carrying out such acid treatment is preferably −150 ° C. to 50 ° C., more preferably −50 ° C. to 40 ° C., and further preferably 0 ° C. to 30 ° C. If the temperature during the acid treatment is too high, a part of —OB ′ in the compound of formula (1 ″) is converted to —OH, and is represented by the following formula (1 ′ ″). Compound (formula (1 ′ ″) compound).

When used as a monomer for obtaining a precursor polymer capable of producing an oxocarbon group-containing polymer electrolyte, the compound of formula (1 ″) is more advantageous than the compound of formula (1 ′ ″). (1 ″ ′) It is preferable to carry out the acid treatment so as to suppress the formation of the compound. The treatment time for acid treatment is usually 1 minute to 1 hour, preferably 2 minutes to 30 minutes, and particularly preferably 3 minutes to 10 minutes. When the treatment time is too long, the compound of the formula (1 ′ ″) is likely to be generated. Therefore, in order to control the formation of the compound of formula (1 ′ ″), the temperature and the treatment time for acid treatment are important factors.
The compound of formula (1 ″) produced by the reaction of alkenyl lithium with 3,4-dialkoxy-3-cyclobutene-1,2-dione and the subsequent acid treatment can be purified by various known purification means. preferable. As the purification means, general purification methods such as column chromatography, distillation, recrystallization and the like can be used.

（Ｂ’は前記と同義である）
を下記式（１’’−ｂ）

（Ｂ’は前記と同義である）
で表される構造や下記式（１’’−ｃ）

（Ｂ’は前記と同義である）
で表される構造等に変更すれば、各々前記（１ｃ）あるいは（１ｄ）を有するようなオキソカーボン基含有高分子電解質を製造し得る式（１’）化合物を製造可能であり、同様な製造方法によれば、種々の式（１’）化合物を得ることもできる。ただし、式（１’）化合物を製造するうえで、より高収率であることを勘案すると、前記式（１’’）化合物のように、式（１’’−ａ）で表される構造を有する化合物が有利なものである。
このようにして得られた式（１’）化合物は付加重合により高分子量化させることにより、オキソカーボン含有高分子電解質を得るための前駆体となる高分子を製造することができる。 With the monomer synthesis method 1 described above, it is possible to obtain a compound of formula (1 ″) which is a suitable compound of formula (1 ′). In addition, the structure represented by the following formula (1 ″ -a) in the compound of the formula (1 ″)

(B 'is as defined above)
Is represented by the following formula (1 ''-b)

(B 'is as defined above)
Or a structure represented by the following formula (1 ″ -c)

(B 'is as defined above)
The compound represented by formula (1 ′), which can produce an oxocarbon group-containing polymer electrolyte having the above (1c) or (1d), can be produced. According to the method, various compounds of the formula (1 ′) can also be obtained. However, considering the higher yield in producing the compound of formula (1 ′), the structure represented by formula (1 ″ -a) like the compound of formula (1 ″) Compounds having the formula are advantageous.
The thus obtained compound of formula (1 ′) can be polymerized by addition polymerization to produce a polymer as a precursor for obtaining an oxocarbon-containing polymer electrolyte.

(Monomer Synthesis Method 2)
Another embodiment of the production method for obtaining the compound of formula (1 ″) will be described.
The compound of the formula (1 ″) can also be produced by reacting 4-alkoxy-3-halogenocyclobutene-1,2-dione and alkenyl tin in an inert gas using a palladium catalyst. Such manufacturing methods are described in, for example, Journal of Organic Chemistry, 55, 5359 (1990) and Tetrahydron Letters, 31 (30), 4293 (1990). 4-Alkoxy-3-halogenocyclobutene-1,2-dione can be produced according to a method described in Tetrahydron Letters, 31 (30), 4293 (1990)).

  Examples of alkenyl tin include tetravinyltin, tetraisopropenyltin, monovinyltrialkyltin, monoisopropenyltrialkyltin, divinyldialkyltin, diisopropenyldialkyltin, trivinylmonoalkyltin, and triisopropenylmonoalkyltin. It is done.

As the palladium catalyst, a palladium (0) compound or a palladium (II) compound and / or a palladium complex is used. For example, suitable palladium catalysts include palladium compounds such as palladium ketonate, palladium acetylacetonate, bis-η ² -olefin palladium dihalide, nitrile palladium halide, olefin palladium halide, palladium halide, benzyl palladium halide, allyl palladium halide. Or palladium biscarboxylate, preferably palladium ketonate, palladium acetylacetonate, bis-η ² -olefin palladium dihalide, palladium (II) halide, benzyl palladium halide, η ³ -allyl palladium halide dimer and palladium dicarboxy rate, particularly preferably bis (dibenzylideneacetone) palladium (0) (Pd (dba) _2), palladium bis acetate Ruasetoneto, bis (benzonitrile) palladium dichloride _{(PdCl 2), Na 2 PdCl} 4, dichlorobis (dimethylsulfoxide) palladium (II), bis (acetonitrile) palladium dichloride, palladium (II) acetate, benzyl chloro bis (triphenylphosphine) Palladium, palladium (II) propionate, baradium (II) butanoate and (1c, 5c-cyclooctadiene) palladium dichloride.
The palladium catalyst is used in an amount of 0.01 to 20 mol%, preferably 0.1 to 10 mol%, based on the number of moles of 4-alkoxy-3-halogenocyclobutene-1,2-dione. 0.5 to 8 mol% is more preferable, and 1 to 6 mol% is particularly preferable.
In this reaction, a compound that can be a ligand can coexist with the palladium catalyst. Examples of the compound that can be such a ligand include phosphines (for example, trialkylphosphines, tricycloalkylphosphines and triarylphosphines), arsines (trialkylarsines, tricycloalkylsulfones). The three substituents on the phosphorus atom or arsenic atom may be the same or different and may be chiral or achiral. Thus, when using the compound which can become a ligand, the usage-amount should be 0.1-20 mol% on the basis of the number-of-moles of 4-alkoxy-3-halogenocyclobutene-1,2-dione. Preferably, it is 0.1 to 15 mol%, more preferably 0.5 to 10 mol%, and particularly preferably 1 to 6 mol%.

In this reaction, any promoter other than the palladium catalyst can be used. The co-catalyst is preferably a copper catalyst, more preferably CuI, CuCN, CuBr, CuBr ₂ , CuCl, CuCl ₂ , CuBr · SBr ₂ , and particularly preferably CuI. The amount of the cocatalyst used is preferably 0.01 to 20 mol%, preferably 0.1 to 18 mol%, based on the number of moles of 4-alkoxy-3-halogenocyclobutene-1,2-dione. More preferably, it is more preferably 0.5 to 15 mol%, and particularly preferably 1 to 12 mol%.

Various solvents can be used in this reaction, but polar solvents are particularly preferable. Examples of such polar solvents include amide solvents such as N, N-dimethylformamide (DMF) and N, N-dimethylacetamide (DMAc), sulfoxide solvents such as dimethyl sulfoxide (DMSO), and N-methylpyrrolidone (NMP). And ether solvents such as tetrahydrofuran, 1,4-dioxane, and 1,3-dioxolane. Preferred are amide solvents and ether solvents, more preferred are amide solvents, and particularly preferred is DMF.
Moreover, 0-150 degreeC is normally used for reaction temperature, Preferably it is 20-100 degreeC, Most preferably, it is 40-80 degreeC.
Various known purification means are used for purification of the product after the reaction, and the purification means is the same as that exemplified in the monomer synthesis method 1.

Here, a method for obtaining a polymer by polymerizing the compound of formula (1 ′) will be described.
The polymerization method is not particularly limited as long as it can be chain-polymerized (addition-polymerized) by the carbon-carbon double bond of the compound of formula (1 ′), and a known method can be used. From anionic polymerization, cationic polymerization, radical polymerization, group transfer polymerization and coordination polymerization, an optimal polymerization method can be selected and used according to the type of the compound of formula (1 ′) to be used. Radical polymerization and anionic polymerization are preferred, and radical polymerization is more preferred. When performing such radical polymerization, free radical polymerization, atom transfer radical polymerization, or the like can be used. The reaction form for performing radical polymerization is not limited to a homogeneous reaction system such as solution polymerization, and multiphase reaction forms such as emulsion polymerization and suspension polymerization can also be used.

Next, among the suitable radical polymerizations, free radical polymerization will be described in detail.
In the case of performing free radical polymerization, examples of usable radical polymerization initiators include azo initiators such as 2,2′-azoisobutyronitrile and 2,2′-azobis (2,4-dimethylvaleronitrile). And peroxide initiators such as benzoyl peroxide, lauryl peroxide, tert-butyl peroctoate, etc., and these polymerization initiators are generally monomers used for polymerization (formula (1 ′) compound or formula ( 1 ′) Total of compound and other monomers) It is preferred that it is in the range of 0.2 to 10 parts by weight per 100 parts by weight.
The radical polymerization can be carried out without a solvent, but it is preferably carried out in the presence of a solvent from the viewpoint of heat removal from the reaction heat. Examples of such solvents include amide solvents such as N, N-dimethylformamide (DMF) and N, N-dimethylacetamide (DMAc), sulfoxide solvents such as dimethyl sulfoxide (DMSO), N-methylpyrrolidone (NMP) and the like. Lactam solvents, ether solvents such as tetrahydrofuran, 1,4-dioxane and 1,3-dioxolane, aliphatic solvents such as cyclohexane, hexane and heptane, aromatic hydrocarbon solvents such as benzene, toluene and xylene, chloroform, Examples include halogen solvents such as dichloromethane, tetrachloroethane, and tetrachloromethane. It should be noted that a water-insoluble solvent (non-aqueous solvent) is selected from these solvents, and the non-aqueous solvent and water are used as the solvent, whereby a multiphase reaction mode can be obtained. In this case, the dispersant used for suspension polymerization, the emulsifier used for emulsion polymerization, and the like can be selected from those well known in the art.

  0-200 degreeC is normally used for the temperature at the time of superposition | polymerization, Preferably it is 20-150 degreeC, Most preferably, it is 40-120 degreeC. The optimum temperature is appropriately selected depending on the type of radical polymerization initiator that is usually used. The polymerization time is usually in the range of 30 minutes to 50 hours, and in the range of 1 to 20 hours, taking into account suitable reaction time for industrial production. In addition, the reaction solution in the middle of the reaction is sampled every predetermined time, and the monomer remaining in the reaction solution is quantified by chromatography analysis (gas chromatography, high performance liquid chromatography, etc.), or gel permeation chromatography ( A suitable reaction time can also be obtained by measuring the molecular weight of the polymer produced by GPC) and obtaining the time point when the desired molecular weight is obtained.

当該前駆体高分子の分子量は、当該前駆体高分子の使用用途又は当該前駆体高分子から得られるオキソカーボン基含有高分子電解質の使用用途によって適宜最適なものを選択することができるが、ＧＰＣを用いたポリスチレン換算の数平均分子量で表して１０００〜１００００００程度が好ましく、３０００〜５０００００程度がさらに好ましく、５０００〜１０００００程度が特に好ましい。 The polymer having the repeating unit represented by the formula (1) thus obtained (hereinafter referred to as “precursor polymer”) is particularly useful as a precursor of an oxocarbon group-containing polymer electrolyte. The repeating unit can be illustrated. A represents a group represented by the formula (10).

The molecular weight of the precursor polymer can be appropriately selected depending on the intended use of the precursor polymer or the intended use of the oxocarbon group-containing polymer electrolyte obtained from the precursor polymer, but GPC was used. The number average molecular weight in terms of polystyrene is preferably about 1,000 to 1,000,000, more preferably about 3,000 to 500,000, and particularly preferably about 5,000 to 100,000.

  Next, the present invention relates to a method for producing an oxocarbon group-containing polymer electrolyte by converting at least a part of the repeating unit represented by the formula (1) in the precursor polymer into the repeating unit represented by the formula (2). explain. The conversion reaction to the repeating unit represented by the formula (2) is preferably performed using a hydrolysis treatment because the operation is simple, and it is particularly preferable to hydrolyze the precursor polymer under acidic conditions. Examples of the acid used for the hydrolysis treatment under acidic conditions include an acid selected from hydrochloric acid, sulfuric acid, nitric acid, acetic acid, trifluoroacetic acid, formic acid and oxalic acid, or a mixture of a plurality of acids selected from these. It is done. As processing temperature concerning a hydrolysis process, it is -150 degreeC-200 degreeC normally, Preferably it is -50 degreeC-100 degreeC, More preferably, it is 0 degreeC-50 degreeC. The treatment time is usually 1 minute to 20 hours, preferably 3 minutes to 10 hours, particularly preferably 5 minutes to 5 hours. When hydrolyzing under acidic conditions, the reaction system may be a homogeneous system or a heterogeneous system. The conversion rate of the repeating unit represented by the formula (1) in the precursor polymer into the repeating unit represented by the formula (2) is appropriately determined depending on the intended use of the resulting oxocarbon group-containing polymer electrolyte. Although the conversion rate can be selected, when the total number of repeating units represented by the formula (1) in the precursor polymer is 100 mol%, the conversion rate is preferably 50 mol% or more, and 80 mol% or more. Particularly preferred.

The oxocarbon group-containing polymer electrolyte obtained in the present invention has an oxocarbon group having high acidity and excellent chemical stability, water resistance and the like as an ion exchange group, so that it is a diaphragm for an electrochemical device such as a fuel cell. As particularly useful. Hereinafter, the case where the oxocarbon group-containing polymer electrolyte is used in such a fuel cell will be described.
In this case, the oxocarbon group-containing polymer electrolyte of the present invention is usually used in the form of a film, but there is no particular limitation on the method of converting into a film, for example, a method of forming a film from a solution state (solution casting method) Are preferably used.
Specifically, the oxocarbon group-containing polymer electrolyte is dissolved in an appropriate solvent, the solution is cast on a supporting substrate such as a glass plate, and the solvent is removed to form a film. The solvent used for film formation is not particularly limited as long as it can dissolve the oxocarbon group-containing polymer electrolyte and can be removed thereafter. N, N-dimethylformamide (DMF), N, N-dimethyl Aprotic polar solvents such as acetamide (DMAc), N-methyl-2-pyrrolidone (NMP), dimethyl sulfoxide (DMSO), or chlorinated solvents such as dichloromethane, chloroform, 1,2-dichloroethane, chlorobenzene, dichlorobenzene, Alcohols such as methanol, ethanol and propanol, alkylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether and propylene glycol monoethyl ether, tet Hydrofuran, 1,3-dioxolane, 1,4-dioxane, 1,3-dioxane, tetrahydropyran, dibutyl ether, tert- butyl methyl ether, diphenyl ether, ether solvents such as crown ethers are preferably used. These can be used singly, but two or more solvents can be mixed and used as necessary.
Among them, dimethyl sulfoxide, N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, tetrahydrofuran, and 1,3-dioxolane are preferable because of high solubility of the oxocarbon group-containing polymer electrolyte.

  Although there is no restriction | limiting in particular in the thickness of a film, 10-300 micrometers is preferable and 20-100 micrometers is especially preferable. When the film is thinner than 10 μm, the practical strength may not be sufficient, and when the film is thicker than 300 μm, the film resistance tends to increase and the characteristics of the electrochemical device tend to deteriorate. The film thickness can be controlled by the concentration of the solution and the coating thickness on the substrate.

For the purpose of improving various physical properties of the film, plasticizers, stabilizers, mold release agents and the like used for ordinary polymers can be added to the polymer of the present invention. Also, other polymers can be combined with the oxocarbon group-containing polymer electrolyte of the present invention by a method such as mixing and casting in the same solvent.
In fuel cell applications, it is also known to add inorganic or organic fine particles as a water retention agent in order to control the amount of water. Any of these known methods can be used as long as they are not contrary to the object of the present invention.

  Further, for the purpose of improving the mechanical strength of the film, it can be crosslinked by irradiating with an electron beam or radiation. Furthermore, a method of impregnating a porous film or sheet into a composite or reinforcing a film by mixing fibers or pulp is known, and these known methods are all for the purpose of the present invention. Can be used as long as not against it.

The fuel cell can be produced by bonding a catalyst and a conductive material as a current collector to both surfaces of the film obtained as described above.
The catalyst is not particularly limited as long as it can activate the oxidation-reduction reaction with hydrogen or oxygen, and a known catalyst can be used, but platinum fine particles are preferably used. It is a particularly preferable form that the fine particles of platinum are often supported on particulate or fibrous carbon such as activated carbon or graphite.
A known material can be used for the conductive material as the current collector, but porous carbon woven fabric, carbon non-woven fabric, or carbon paper is preferable in order to efficiently transport the raw material gas to the catalyst.
For a method of bonding platinum fine particles or carbon carrying platinum fine particles to a porous carbon nonwoven fabric or carbon paper, and a method of bonding it to a polymer electrolyte film, see, for example, J. Org. Electrochem. Soc. : Known methods such as those described in Electrochemical Science and Technology, 1988, 135 (9), 2209 can be used.
The oxocarbon group-containing polymer electrolyte of the present invention can also be used as a proton conductive material that is a component of a catalyst composition constituting a catalyst layer of a fuel cell.
The fuel cell of the present invention thus produced can be used in various forms using hydrogen gas, reformed hydrogen gas, methanol, dimethyl ether, etc. as fuel.

  Although the embodiments of the present invention have been described above, the embodiments of the present invention disclosed above are merely examples, and the scope of the present invention is not limited to these embodiments. The scope of the present invention is defined by the terms of the claims, and further includes meanings equivalent to the description of the claims and all modifications within the scope.

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples.
The molecular weight was measured by gel permeation chromatography (GPC) by measuring the number average molecular weight (Mn) and / or the weight average molecular weight (Mw) in terms of polystyrene under the following conditions.
GPC measuring device HLC-8220 manufactured by TOSOH
Two columns KD-80M manufactured by Shodex are connected in series Column temperature 40 ° C
Mobile phase solvent DMAc (LiBr added to 10 mmol / dm ³ )
Solvent flow rate 0.5mL / min

Example 1 Preparation of 3-chloro-4-isopropoxy-3-cyclobutene-1,2-dione In an argon atmosphere, 15.6 g of 3,4-dihydroxy-3-cyclobutene-1,2-dione was placed in a flask. 13.7 mmol), 51.5 g (433 mmol) of thionyl chloride and 2 drops of N, N-dimethylformamide were added and stirred at 50 ° C. for 5 hours. Thereafter, unreacted thionyl chloride was distilled off under reduced pressure, and 2-propanol (11.7 g, 195 mmol) was added dropwise thereto at room temperature, and the mixture was stirred as such for 2 hours at room temperature. Excess 2-propanol was distilled off under reduced pressure, and further distillation under reduced pressure gave 17.1 g (9.80 mmol) of the desired 3-chloro-4-isopropoxy-3-cyclobutene-1,2-dione. It was.

Example 2 Production of 3-vinyl-4-isopropoxy-3-cyclobutene-1,2-dione 3-chloro-4-isopropoxy-3-cyclobutene obtained in Reference Example 1 under an argon atmosphere -1,2-dione 3.85 g (22.0 mmol), tetravinyltin 5.00 g (22.0 mmol), and N, N-dimethylformamide 10 ml were added. Further, 833 mg (1.10 mmol) of benzylchloropalladium bistriphenylphosphine and 314 mg (1.65 mmol) of copper iodide were added and reacted at room temperature for 20 hours. The solution after the reaction was diluted with 50 ml of ethyl acetate, washed with a 10% aqueous potassium fluoride solution, and further extracted with ethyl acetate. The organic layer was dried over magnesium sulfate, and the solvent was distilled off with an evaporator. The obtained residue was purified by a silica gel column (mobile phase; hexane: ethyl acetate = 3: 1), and the target 3-vinyl-4-isopropoxy-3-cyclobutene-1,2-dione 3.40 g (20. 5 mmol) was obtained.

Example 3 Polymerization of 3-vinyl-4-isopropoxy-3-cyclobutene-1,2-dione 3-vinyl-4-isopropoxy-3-cyclobutene obtained in Example 2 under an argon atmosphere 1.0 ml of chloroform was dissolved in 0.500 g (3.01 mmol) of -1,2-dione. The system was frozen using liquid nitrogen, and reduced in pressure and introduced with argon using a vacuum pump. This was repeated three times and the system was replaced with argon. At room temperature, 99.0 mg (0.602 mmol) of azoisobutyronitrile was added, and the mixture was heated and stirred at 65 ° C. for 15 hours. Thereafter, chloroform was distilled off, and the residue was washed with a mixture of 2N HCl and methanol (75:25 (vol / vol)) to obtain 0.450 g of polymer (a). The number average molecular weight Mn determined by GPC was 6000.

(Example 4) Hydrolysis of polymer a 0.450 g of the polymer (a) obtained in Example 3 was dissolved in 5 ml of THF, and 10 ml of concentrated hydrochloric acid was further added. This mixture was heated and stirred at 60 ° C. for 20 hours to hydrolyze the isopropoxy group. After the reaction, the solvent was distilled off with an evaporator and dissolved in 30 ml of ethyl acetate. The solution was passed through a short silica gel column (about 5 cm in length) to remove fine impurities, and the solvent was distilled off with an evaporator to obtain 0.302 g of hydrolyzed polymer (b).

Claims (13)

A compound represented by the following formula (1 ′).

(In the formula, X ¹ and X ² each independently represent —O—, —S— or —NR—, and Z represents —C (O) —, —C (S) —, —C (NR ′)). -Represents an alkylene group which may have a substituent or an arylene group which may have a substituent (R and R 'in -NR- and NR' each independently represents a hydrogen atom, a substituent, An alkyl group having 1 to 6 carbon atoms which may have a substituent or an aryl group having 6 to 10 carbon atoms which may have a substituent.) N represents an integer of 0 to 10. n is an integer. When it is 2 or more, a plurality of Z may be the same or different from each other, and Q ¹ , Q ² and Q ³ are each independently a hydrogen atom or a carbon number which may have a substituent. 1-6 alkyl group, .B representing an aryl group, or a halogen atom carbon atoms 6 to 10 which may have a substituent ^"is a monovalent organic A representative.)   The compound according to claim 1, wherein, in the formula (1 '), Z is selected from -C (O)-, -C (S)-, and -C (NH)-. The compound according to claim 1, wherein, in the formula (1 '), X ¹ and X ² are both -O-, Z is -C (O)-, and n is an integer of 0-2.   A polymer obtained by using the compound according to claim 1 as a monomer and subjecting the monomer to addition polymerization. A polymer having a repeating unit represented by the following formula (1).

(In the formula, X ¹ and X ² each independently represent —O—, —S— or —NR—, and Z represents —C (O) —, —C (S) —, —C (NR ′)). -Represents an alkylene group which may have a substituent or an arylene group which may have a substituent (R and R 'in -NR- and NR' each independently represents a hydrogen atom, a substituent, An alkyl group having 1 to 6 carbon atoms which may have a substituent or an aryl group having 6 to 10 carbon atoms which may have a substituent.) N represents an integer of 0 to 10. n is an integer. When it is 2 or more, a plurality of Z may be the same or different from each other, and Q ¹ , Q ² and Q ³ are each independently a hydrogen atom or a carbon number which may have a substituent. 1-6 alkyl group, .B representing an aryl group, or a halogen atom carbon atoms 6 to 10 which may have a substituent ^"is a monovalent organic A representative.)   The polymer according to claim 5, wherein, in the formula (1), Z is selected from -C (O)-, -C (S)-, and -C (NH)-. The polymer according to claim 5, wherein in the formula (1), X ¹ and X ² are both —O—, Z is —C (O) —, and n is an integer of 0 to 2. A polymer obtained by converting at least a part of the repeating unit represented by the formula (1) in the polymer according to any one of claims 5 to 7 into a repeating unit represented by the following formula (2): molecule.

(In the formula, B represents a hydrogen atom or a metal atom. When B is a metal atom, it may be bonded to other substituents. Other symbols are X ¹ , X ² , Z, n, Q ^1, Q ² and Q ³ are as defined above.)   The polymer electrolyte which uses the polymer in any one of Claims 5-8 as an active ingredient.   A polymer electrolyte membrane comprising the polymer electrolyte according to claim 9.   A catalyst composition comprising the polymer electrolyte according to claim 9 and a catalyst component.   A membrane-electrode assembly comprising any one of the polymer electrolyte according to claim 9, the polymer electrolyte membrane according to claim 10, and the catalyst layer using the catalyst composition according to claim 11.   A polymer electrolyte fuel cell comprising the membrane-electrode assembly according to claim 12.