JP5266691B2 - Polymer, polymer electrolyte and fuel cell using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polymer which exhibits high ion conductivity and very low temperature dependence of the ion conductivity, when used for electrolyte membranes in fuel cells. <P>SOLUTION: A polymer having the structural unit expressed by general formula (1a), a polymer having a segment composed of the structural unit expressed by general formula (1a) and a copolymerization form of block copolymerization, a polymer electrolyte containing the polymer and a fuel cell member composed of the polymer electrolyte are provided (wherein, a1 is an integer of &ge;1; Ar<SP>1</SP>is a divalent aromatic group having an ion exchange group; X is a divalent electron-withdrawing group). <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a polymer electrolyte, particularly a polymer suitably used as a fuel cell member.

  A polymer having proton conductivity, that is, a polymer electrolyte, is used as a material constituting a diaphragm of an electrochemical device such as a primary battery, a secondary battery, or a solid polymer fuel cell. For example, Nafion (registered trademark of DuPont) and other polyelectrolytes having a perfluoroalkylsulfonic acid as a super strong acid in the side chain and a polymer having a main chain of a perfluoroalkane chain as an active ingredient However, since it has excellent power generation characteristics when used as a diaphragm material for fuel cells, it has been mainly used conventionally. However, it has been pointed out that this type of material is very expensive, has low heat resistance, has low film strength, and is not practical without some reinforcement.

Under such circumstances, development of inexpensive and excellent polymer electrolytes that can replace the polymer electrolytes has recently been activated.
For example, a block copolymer having a segment in which a sulfonic acid group is not substantially introduced and a segment in which a sulfonic acid group is introduced, wherein the former segment is made of polyethersulfone and the latter segment is diphenylsulfone and A block copolymer having an ether bond with a biphenol having a sulfonic acid group as a repeating unit has been proposed, and when such a block copolymer is used as a proton conductive membrane, fluctuation of proton conductivity due to humidity (hereinafter referred to as “humidity”). It is disclosed that it can be suitably applied to a fuel cell (refer to Patent Document 1, for example).

JP 2003-031232 A (Claims)

However, the block copolymer disclosed in Patent Document 1 is not necessarily sufficiently small in terms of humidity dependence of proton conductivity, and further, proton conductivity itself under low humidity is sufficient. There wasn't.
It is an object of the present invention to provide a polymer that, when used as an electrolyte membrane, has not only a high degree of ionic conductivity, but also has a remarkably small humidity dependency of such ionic conductivity. Furthermore, it is providing the polymer electrolyte which uses this polymer as an active ingredient, the member for fuel cells using this polymer electrolyte, and the polymer electrolyte fuel cell using this member.

  The inventors of the present invention have completed the present invention as a result of intensive studies to find a polymer exhibiting superior performance as a polymer electrolyte applied to an ion conductive membrane for a fuel cell.

（式中、ａ１は１以上の整数を表す。Ａｒ¹はイオン交換基を有する２価の芳香族基を表し、イオン交換基以外の置換基を有していてもよい。Ａｒ⁰は置換基を有していてもよい２価の芳香族基を表し、ａ１が２以上である場合、複数のＡｒ⁰は互いに同一でも異なっていてもよい。Ｘは２価の電子吸引性基を表す。）
を提供する。 That is, the present invention provides [1] a polymer having a structural unit represented by the following general formula (1a)

(Wherein, a1 represents an integer of 1 or more. Ar ¹ represents a divalent aromatic group having an ion exchange group, and may have a substituent other than the ion exchange group. Ar ⁰ is a substituent. And a1 is 2 or more, a plurality of Ar ⁰ may be the same as or different from each other, and X represents a divalent electron-withdrawing group. )
I will provide a.

  A polymer electrolyte membrane obtained from such a polymer has a small dependence of proton conductivity on humidity, and is a polymer electrolyte membrane that is very useful in fuel cell applications.

（式中、Ａｒ¹およびＸは前記と同義であり、２つのＡｒ¹は互いに同一でも異なっていてもよい。）

（式中、Ａｒ⁰は前記と同義である。） Moreover, this invention provides following [2] as suitable embodiment of the said polymer.
[2] The polymer according to [1], having a structural unit represented by the following general formula (1b) and a structural unit represented by the following general formula (1c)

(In the formula, Ar ¹ and X are as defined above, and two Ar ^{1 s} may be the same as or different from each other.)

(In the formula, Ar ⁰ has the same meaning as described above.)

（式中、ａは２以上の整数を表す。Ａｒ¹およびＸは前記と同義であり、複数あるＡｒ¹は互いに同一でも異なっていてもよい。Ｘは２価の電子吸引性基を表す。）
［４］下記一般式（２）で表されるセグメントを有する、［３］記載のポリマー。

（式中、Ａｒ¹およびＸは前記と同義である。ｆは１以上の整数を表わし、２つのｆは互いに同一でも異なっていてもよい。複数あるＡｒ¹は互いに同一でも異なっていてもよい。ｍは繰り返し単位数を表す。）
［５］ｍが５以上の整数である、［４］記載のポリマー。 The structural unit represented by the general formula (1a) preferably has an ion exchange group not only in Ar ¹ adjacent to X but also in all Ar ^{0 which} is one or more, and in this way It is more preferable that the structural unit consisting of an aromatic group having a group is connected to form a segment. Therefore, the following [3] to [5] are provided.
[3] The polymer according to [1], wherein the structural unit represented by the general formula (1a) is a structural unit represented by the following general formula (1):

(Wherein, a is the .Ar ¹ and X represents an integer of 2 or more the same meaning as defined above, Ar ¹ there are a plurality of which may be the same or different .X represents a divalent electron withdrawing group. )
[4] The polymer according to [3], having a segment represented by the following general formula (2).

(In the formula, Ar ¹ and X are as defined above. F represents an integer of 1 or more, and two f may be the same or different from each other. Plural Ar ¹ may be the same or different from each other. M represents the number of repeating units.)
[5] The polymer according to [4], wherein m is an integer of 5 or more.

（式中、Ｒ¹は、フッ素原子、置換基を有していてもよい炭素数１〜２０のアルキル基、置換基を有していてもよい炭素数１〜２０のアルコキシ基、置換基を有していてもよい炭素数６〜２０のアリール基、置換基を有していてもよい炭素数６〜２０のアリールオキシ基または置換基を有していてもよい炭素数２〜２０のアシル基であり、ｐは０または１である。） Moreover, this invention provides the following [6]-[8] as suitable embodiment which concerns on one of the said polymers.
[6] X is an electron-withdrawing group selected from the group consisting of a carbonyl group, a sulfonyl group, and a 1,1,1,3,3,3-hexafluoro-2,2-propylidene group. [5] The polymer according to any one of [1] to [5], wherein the ion exchange group in Ar [7] Ar ¹ is directly bonded to an aromatic ring constituting the main chain. [8] The polymer [9] Ar ^{1 according} to any one of [1] to [7], wherein the ion exchange group is an acid group selected from a sulfonic acid group, a sulfonimide group, a phosphonic acid group, and a carboxyl group. The polymer according to any one of [1] to [8], which is an aromatic group represented by the general formula (4).

(In the formula, R ¹ represents a fluorine atom, an optionally substituted alkyl group having 1 to 20 carbon atoms, an optionally substituted alkoxy group having 1 to 20 carbon atoms, or a substituent. An optionally substituted aryl group having 6 to 20 carbon atoms, an optionally substituted aryloxy group having 6 to 20 carbon atoms, or an optionally substituted acyl having 2 to 20 carbon atoms And p is 0 or 1.)

（式中、ｂ、ｃ、ｄは互いに独立に０か１を表し、ｎは５以上の整数を表す。Ａｒ³、Ａｒ⁴、Ａｒ⁵、Ａｒ⁶は互いに独立に２価の芳香族基を表し、ここでこれらの２価の芳香族基は、置換基を有していてもよい炭素数１〜２０のアルキル基、置換基を有していてもよい炭素数１〜２０のアルコキシ基、置換基を有していてもよい炭素数６〜２０のアリール基、置換基を有していてもよい炭素数６〜２０のアリールオキシ基または置換基を有していてもよい炭素数２〜２０のアシル基で、置換されていてもよい。Ｙ、Ｙ’は、互いに独立に直接結合または２価の基を表す。Ｚ、Ｚ’は、互いに独立に酸素原子または硫黄原子を表す。） The present invention also provides the following [10] and [11] as preferred embodiments according to the above [4] or [5].
[10] As a segment having an ion exchange group, it has a segment represented by the above general formula (2), and further has a segment having substantially no ion exchange group, and the copolymerization mode is block copolymerization. The polymer [11] according to any one of [4] to [9], wherein the segment substantially not having an ion exchange group is a segment represented by the following general formula (3): polymer

(In the formula, b, c and d each independently represent 0 or 1, and n represents an integer of 5 or more. Ar ³ , Ar ⁴ , Ar ⁵ and Ar ⁶ independently represent a divalent aromatic group. Wherein these divalent aromatic groups are optionally substituted alkyl groups having 1 to 20 carbon atoms, optionally substituted alkoxy groups having 1 to 20 carbon atoms, A C6-C20 aryl group which may have a substituent, a C6-C20 aryloxy group which may have a substituent, or a C2-C2 which may have a substituent 20 may be substituted with an acyl group. Y and Y ′ each independently represent a direct bond or a divalent group, and Z and Z ′ each independently represent an oxygen atom or a sulfur atom.)

The polymer of the present invention preferably controls its ion exchange capacity in terms of achieving both higher ion conductivity and water resistance as a fuel cell member, that is, it provides the following [12]. .
[12] The polymer according to any one of [1] to [11], wherein the ion exchange capacity is 0.5 meq / g to 4.0 meq / g.

Furthermore, the present invention provides the following [13] to [18] using any one of the above polymers.
[13] Polymer electrolyte comprising any of the polymers described above as an active ingredient [14] Polymer electrolyte membrane comprising the polymer electrolyte described in [13] [15] [13] The polymer electrolyte described in [13], and porous A polymer electrolyte membrane according to [17] [14] or a polymer electrolyte membrane according to [15] comprising a polymer electrolyte according to [16] [13] and a catalyst component comprising a polymer electrolyte composite membrane comprising a substrate A polymer electrolyte fuel cell comprising a catalyst layer obtained by using the catalyst composition according to the polymer electrolyte fuel cell [18] [16] using a molecular electrolyte composite membrane as an ion conductive membrane

  When the polymer of the present invention is used as a member for a fuel cell, particularly as an ion conductive membrane, the humidity dependency of the ionic conductivity is small, and a suitable ion conductive membrane can be provided. This effect relating to humidity dependency is also suitable when the polymer of the present invention is applied to the catalyst layer of a polymer electrolyte fuel cell. In particular, when the ion exchange group of the polymer of the present invention is an acid group, when used as a proton conductive membrane for a fuel cell, the fuel cell exhibits a high power generation efficiency. Thus, the polymer of the present invention is extremely useful industrially, particularly in fuel cell applications.

（式中、ａ１は１以上の整数を表す。Ａｒ¹はイオン交換基を有する２価の芳香族基を表し、イオン交換基以外の置換基を有していてもよい。Ａｒ⁰は置換基を有していてもよい２価の芳香族基を表し、ａ１が２以上である場合、複数のＡｒ⁰は互いに同一でも異なっていてもよい。Ｘは２価の電子吸引性基を表す。）
ここで、「イオン交換基」とは、本発明のポリマーを膜の形態である電解質膜として用いたとき、イオン伝導を発現する基であり、「イオン交換基を有する」とはＡｒ¹にある芳香環に直接イオン交換基が結合している形態や、原子または原子団を介してイオン交換基がＡｒ¹にある芳香環に結合している形態を含む概念である。 The polymer of the present invention has a structural unit represented by the following general formula (1a).

(Wherein, a1 represents an integer of 1 or more. Ar ¹ represents a divalent aromatic group having an ion exchange group, and may have a substituent other than the ion exchange group. Ar ⁰ is a substituent. And a1 is 2 or more, a plurality of Ar ⁰ may be the same as or different from each other, and X represents a divalent electron-withdrawing group. )
Here, the “ion exchange group” is a group that exhibits ionic conduction when the polymer of the present invention is used as an electrolyte membrane in the form of a membrane, and “having an ion exchange group” is in Ar ¹ . The concept includes a form in which an ion exchange group is directly bonded to an aromatic ring and a form in which the ion exchange group is bonded to an aromatic ring in Ar ¹ via an atom or an atomic group.

In the general formula (1a), the “electron withdrawing group” is a group having a positive Hammett's σ value. In the present invention, an electron withdrawing group having a Hammett substituent constant of +0.01 or more when para-substituted is preferable, and —CO— (carbonyl group), —SO ₂ — (sulfonyl group), —C (CF ₃ ) _2- (1,1,1,3,3,3-hexafluoro-2,2-propylidene group) is particularly preferable.

The present inventor has found that the polymer having the structural unit represented by the general formula (1a) can obtain a film having a remarkably small humidity dependency of ionic conductivity when converted into a film form. . As a member for a fuel cell, the battery can be easily operated even in a low humidity state when the battery is activated, and an excellent effect of obtaining stable power generation performance even when the humidity is improved to a certain level can be exhibited. Although it is not certain, if the aromatic group Ar ¹ adjacent to the electron-withdrawing group X has an ion exchange group, the ion-withdrawing property of X improves the ion dissociation of the ion-exchange group. It is estimated that such humidity dependence is expressed. In addition, in order to use as a fuel cell member, durability against peroxides and radicals generated for fuel cell operation may be required. It is expected that the polymer having the structural unit represented by the general formula (1a) can also exhibit such an effect of excellent durability due to the effect of the electron withdrawing group X in this respect.
In addition, the membrane is excellent in dimensional stability related to water absorption, and the stress due to water absorption swelling and drying shrinkage of the polymer electrolyte membrane due to repeated operation and stop of the battery can be extremely reduced. It is possible to suppress the battery life and to extend the life of the battery itself.

Ar ⁰ represents a divalent aromatic group which may have a substituent. The substituent may be an ion exchange group or a group having an ion exchange group. a1 represents an integer of 1 or more. The upper limit of a1 is the type of Ar ^0, in particular Ar ⁰ is according to whether having an ion-exchange group can be selected within the range satisfying the preferred ion exchange capacity of the above. Considering the ease of production, a1 is preferably 10 or less, more preferably 5 or less, and even more preferably 3 or less.

  The polymer of the present invention may be a copolymer of the structural unit represented by the general formula (1a) and another structural unit. In the case of such a copolymer, the content of the structural unit represented by the general formula (1a) is preferably 5% by weight to 80% by weight, and 15% by weight to 60% by weight. When used as an electrolyte membrane, water resistance is improved in addition to high ion conductivity, which is particularly preferable.

In addition, the divalent aromatic group Ar ¹ having an ion exchange group in the general formula (1a) is particularly preferably a monocyclic aromatic group. Examples of such monocyclic aromatic groups include a 1,3-phenylene group and a 1,4-phenylene group.

Ar ¹ is characterized by having an ion exchange group, but may have a substituent other than the ion exchange group. Examples of the substituent include a fluorine atom, an optionally substituted alkyl group having 1 to 20 carbon atoms, an optionally substituted alkoxy group having 1 to 20 carbon atoms, and a substituent. An optionally substituted aryl group having 6 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms which may have a substituent, or an acyl group having 2 to 20 carbon atoms which may have a substituent. Can be mentioned.

  Examples of the optionally substituted alkyl group having 1 to 20 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group, n- Carbon such as pentyl group, 2,2-dimethylpropyl group, cyclopentyl group, n-hexyl group, cyclohexyl group, 2-methylpentyl group, 2-ethylhexyl group, nonyl group, dodecyl group, hexadecyl group, octadecyl group, icosyl group Fluorine atom, hydroxyl group, nitrile group, amino group, methoxy group, ethoxy group, isopropyloxy group, phenyl group, naphthyl group, phenoxy group, naphthyloxy group, etc. And an alkyl group having a total carbon number of 20 or less.

  Examples of the optionally substituted alkoxy group having 1 to 20 carbon atoms include methoxy group, ethoxy group, n-propyloxy group, isopropyloxy group, n-butyloxy group, sec-butyloxy group, tert. -Butyloxy group, isobutyloxy group, n-pentyloxy group, 2,2-dimethylpropyloxy group, cyclopentyloxy group, n-hexyloxy group, cyclohexyloxy group, 2-methylpentyloxy group, 2-ethylhexyloxy group, Alkoxy groups having 1 to 20 carbon atoms such as dodecyloxy group, hexadecyloxy group, icosyloxy group, and the like, fluorine atom, hydroxyl group, nitrile group, amino group, methoxy group, ethoxy group, isopropyloxy group, phenyl Group, naphthyl group, phenoxy group, naphthylo Such as shea group is substituted, the total carbon number, and the like alkoxy groups is 20 or less.

  Examples of the aryl group having 6 to 20 carbon atoms that may have a substituent include aryl groups such as a phenyl group, a naphthyl group, a phenanthrenyl group, and an anthracenyl group, and a fluorine atom, a hydroxyl group, and a nitrile group. Amino groups, methoxy groups, ethoxy groups, isopropyloxy groups, phenyl groups, naphthyl groups, phenoxy groups, naphthyloxy groups, and the like, and aryl groups having a total carbon number of 20 or less.

  Examples of the aryloxy group having 6 to 20 carbon atoms which may have a substituent include aryloxy groups such as a phenoxy group, a naphthyloxy group, a phenanthrenyloxy group, and an anthracenyloxy group, and these The group is substituted with fluorine atom, hydroxyl group, nitrile group, amino group, methoxy group, ethoxy group, isopropyloxy group, phenyl group, naphthyl group, phenoxy group, naphthyloxy group, etc., and the total number of carbon atoms is 20 or less An aryloxy group etc. are mentioned.

  Examples of the acyl group having 2 to 20 carbon atoms which may have a substituent include 2 carbon atoms such as acetyl group, propionyl group, butyryl group, isobutyryl group, benzoyl group, 1-naphthoyl group and 2-naphthoyl group. ~ 20 acyl groups, and these groups are substituted with fluorine atom, hydroxyl group, nitrile group, amino group, methoxy group, ethoxy group, isopropyloxy group, phenyl group, naphthyl group, phenoxy group, naphthyloxy group, etc. The acyl group whose total carbon number is 20 or less, etc. are mentioned.

As an ion exchange group in Ar ¹ , either an acid group or a basic group can be applied, but an acid group is usually used. Examples of the acid group include weak acid groups, strong acid groups, and super strong acid groups, but strong acid groups and super strong acid groups are preferable. Examples of acid groups include, for example, weak acid groups such as phosphonic acid groups (—PO ₃ H ₂ ) and carboxyl groups (—COOH); sulfonic acid groups (—SO ₃ H), sulfonimide groups (—SO ₂ —NH). -SO ₂ -R, where R represents a monovalent substituent such as an alkyl group or an aryl group.) Among them, sulfonic acid groups and sulfonimide groups which are strong acid groups are preferably used. Is done. Further, by substituting a hydrogen atom on the substituent (—R) of Ar ¹ and / or the sulfonimide group with an electron withdrawing group such as a fluorine atom, the strong acid group can be superseded by the effect of the electron withdrawing group. It can also function as a strong acid group.
These ion exchange groups may be partially or completely exchanged with metal ions or quaternary ammonium ions to form a salt, but when used as a polymer electrolyte membrane for fuel cells, etc. It is preferred that substantially all are in the free acid state.
As described above, the ion exchange group may be bonded to an aromatic ring constituting the main chain of the polymer having the structural unit represented by the general formula (1a) via a linking group. However, it is preferable to be directly bonded to the aromatic ring constituting the main chain because the polymer of the present invention can be easily produced using a material that can be easily obtained from the market. .

In addition, Ar ⁰ in the general formula (1a) may be a divalent aromatic group having an ion exchange group similar to Ar ¹ as described above, or may not have an ion exchange group. The other description is the same as Ar ¹ .

  When the polymer of the present invention is a copolymer, the copolymerization mode may be any of random copolymerization, alternating copolymerization, block copolymerization, or graft copolymerization. Suitable polymers for copolymerization will be described later.

（式中、ａは２以上の整数を表す。Ａｒ¹およびＸは前記と同義であり、複数あるＡｒ¹は互いに同一でも異なっていてもよい。Ｘは２価の電子吸引性基を表す。）
なお、上記一般式（１）で表す構造単位において、イオン交換基を有する芳香族基Ａｒ¹において、電子吸引性基Ｘから遠い基であるほど、電子吸引効果を受け難いので、ａは、２〜４の範囲が好ましく、製造上容易である点からみれば、ａが２であると特に好ましい。 In the general formula (1a), when the aromatic group Ar ⁰ closer to the electron-withdrawing group X has an ion-exchange group as described above, the humidity dependence of the ionic conductivity due to the electron-withdrawing effect is the same as Ar ¹ . Is expected to be better. From this viewpoint, Ar ⁰ is preferably an aromatic group that is an ion exchange group, that is, an aromatic group similar to Ar ¹ . In other words, the structural unit represented by the general formula (1a) is preferably a structural unit represented by the following general formula (1).

(Wherein, a is the .Ar ¹ and X represents an integer of 2 or more the same meaning as defined above, Ar ¹ there are a plurality of which may be the same or different .X represents a divalent electron withdrawing group. )
In the structural unit represented by the general formula (1), in the aromatic group Ar ¹ having an ion exchange group, the farther from the electron withdrawing group X, the less likely to receive the electron withdrawing effect. A range of ˜4 is preferable, and a is preferably 2 in view of easy production.

Hereinafter, the structural unit represented by the general formula (1), which is a preferable structural unit, will be described.
Specific examples of the structural unit represented by the general formula (1) include the following (1-1) to (1-26) (where (1-13) to (1-15) Some “—Ph” represents a phenyl group).

前記（１−１）〜（１−２６）においてＪは、イオン交換基であるか、イオン交換基を有する基を表し、具体的には下記の群から選ばれる基である。なお、同一構造単位中にある複数のＪは互いに同一でも異なっていてもよい。

（式中、Ａ、Ａ’はそれぞれ独立に炭素数１〜６のアルキレン基または炭素数１〜６のフッ素置換アルキレン基を表し、Ａ’が複数ある場合、それらは互いに同一でも異なっていてもよい。ｋは１〜４の整数を表し、Ｔはイオン交換基を表し、＊は結合手を表す。）
なお、上記において「フッ素置換アルキレン基」とはアルキレン基の炭素原子に結合している水素原子の一部または全部がフッ素原子に置き換わった基を意味する。

In the above (1-1) to (1-26), J represents an ion exchange group or a group having an ion exchange group, and specifically a group selected from the following group. In addition, several J in the same structural unit may mutually be same or different.

(In the formula, A and A ′ each independently represent an alkylene group having 1 to 6 carbon atoms or a fluorine-substituted alkylene group having 1 to 6 carbon atoms, and when there are a plurality of A ′, they may be the same or different from each other. K represents an integer of 1 to 4, T represents an ion exchange group, and * represents a bond.)
In the above, the “fluorine-substituted alkylene group” means a group in which part or all of the hydrogen atoms bonded to the carbon atom of the alkylene group are replaced with fluorine atoms.

  The polymer of the present invention contains a structural unit represented by the above general formula (1a), preferably a structural unit represented by the above general formula (1) as a structural unit having an ion exchange group that exhibits ion conductivity. And the introduction amount of the ion exchange group is preferably 0.5 to 4.0 meq / g in terms of ion exchange capacity. When it is 0.5 meq / g or more, ion conductivity is further improved, and the function as a polymer electrolyte for a fuel cell is more excellent, which is preferable. On the other hand, when the ion exchange capacity is 4.0 meq / g or less, the water resistance becomes better, which is preferable. The ion exchange capacity is more preferably 1.0 to 3.0 meq / g.

（式中、Ａｒ¹、Ｘは前記と同義である。ｆは１以上の整数を表わし、２つのｆは互いに同一でも異なっていてもよい。ｍは繰り返し単位数を表す。） Furthermore, as a suitable polymer, the polymer which has the segment which consists of a structural unit represented by the said General formula (1), ie, the segment represented by the following General formula (2), in a molecule | numerator is mentioned. Such a polymer is more preferable because it is particularly excellent in ion conductivity.

(In the formula, Ar ¹ and X are as defined above. F represents an integer of 1 or more, two fs may be the same as or different from each other, and m represents the number of repeating units.)

  m represents the number of repeating units of the structural unit in parentheses in the general formula (2), m is preferably an integer of 5 or more, more preferably in the range of 5 to 1000, and still more preferably 10 to 500. . When the value of m is 5 or more, higher proton conductivity can be obtained, and when the value of m is 1000 or less, it is preferable because production of such a segment becomes easier.

（式中、Ｒ¹は、フッ素原子、置換基を有していてもよい炭素数１〜２０のアルキル基、置換基を有していてもよい炭素数１〜２０のアルコキシ基、置換基を有していてもよい炭素数６〜２０のアリール基、置換基を有していてもよい炭素数６〜２０のアリールオキシ基または置換基を有していてもよい炭素数２〜２０のアシル基であり、ｐは０または１である。） The segment represented by the general formula (2) is preferably a segment in which Ar ¹ of the segment is an aromatic group represented by the following general formula (4). Moreover, the sulfonic acid group directly bonded to the aromatic ring in this way is excellent in the effect of reducing the humidity dependency due to the electron withdrawing property of the adjacent X. Moreover, since the segment which consists of an aromatic group represented by General formula (4) can be easily manufactured using the material which can be obtained easily from a market, it is preferable. In addition, the suitable example which concerns on this manufacture is mentioned later.

(In the formula, R ¹ represents a fluorine atom, an optionally substituted alkyl group having 1 to 20 carbon atoms, an optionally substituted alkoxy group having 1 to 20 carbon atoms, or a substituent. An optionally substituted aryl group having 6 to 20 carbon atoms, an optionally substituted aryloxy group having 6 to 20 carbon atoms, or an optionally substituted acyl having 2 to 20 carbon atoms And p is 0 or 1.)

R ¹ in the general formula (4) is a substituent selected from an alkyl group, an alkoxy group, an aryl group, or an acyl group, and the substituent is the same as those exemplified as the substituent for Ar ¹ . In the production method described later, this is a group that does not inhibit the polymerization reaction. P representing the number of substituents is 0 or 1, and particularly preferably p is 0, that is, an aromatic group having no such substituent.

（式中、Ａｒ¹⁰はイオン交換基を有する２価の芳香族基を表す。） The polymer of the present invention has the segment represented by the general formula (2) as a segment having an ion exchange group, and further has a segment substantially free of an ion exchange group, and the copolymerization mode is blocked. A polymer that is a copolymer (hereinafter simply referred to as “block copolymer”) is preferred because the water absorption property tends to be improved. In addition, when such a block copolymer is used as a membrane, a microphase separation structure in which a segment having an ion exchange group and a segment having substantially no ion exchange group are separated into a dense phase. And can be controlled to take a continuous layer. Thereby, high ion conductivity and water absorption characteristics can be achieved at the same time.
In such a block copolymer, the structural unit constituting the segment having an ion exchange group may have a structural unit other than the general formula (1), but the total amount of the segment having the ion exchange group is 100. When the weight percent, the structural unit represented by the general formula (1) is preferably 50% by weight or more, more preferably 70% by weight or more, and the structural unit substantially represented by the general formula (1). Is particularly preferably a block copolymer in which all segments having an ion exchange group are composed of segments represented by the general formula (2).
In addition, as a thing other than the structural unit represented by the said General formula (1) which comprises the segment which has an ion exchange group, the structural unit represented by the following General formula (10) is suitable.

(In the formula, Ar ¹⁰ represents a divalent aromatic group having an ion exchange group.)

Moreover, in the said block copolymer, it has a segment represented by the said General formula (2) as a segment which has an ion exchange group, Furthermore, from structural units other than the structural unit represented by General formula (1). The polymer in a form having a segment (hereinafter referred to as “segment having another ion exchange group”) may be used. The segment having other ion exchange groups is a segment having 0.5 or more ion exchange groups expressed by the number of ion exchange groups per structural unit constituting the segment, and preferably constitutes a segment. Examples thereof include those having 1.0 or more ion exchange groups per structural unit.
The amount of ion exchange groups introduced in the segment represented by the general formula (2) and the segment having other ion exchange groups in the block copolymer is expressed as an ion exchange group equivalent per the total weight of the segments. 2.5 meq / g to 10.0 meq / g, more preferably 3.5 meq / g to 9.0 meq / g, and particularly preferably 4.5 meq / g to 7.0 meq / g.
When the ion exchange group introduction amount is 2.5 meq / g or more, the ion exchange groups are closely adjacent to each other, which is preferable because ion conductivity is higher. On the other hand, ion exchange groups exhibiting an ion exchange group introduction amount are preferable. It is preferable for the capacity to be 10.0 meq / g or less because the production is easier.

Next, the segment having substantially no ion exchange group will be described.
As described above, the segment having substantially no ion-exchange group has 0.1 or less ion-exchange groups calculated per repeating unit, and the ion-exchange groups per structural unit is less than Particularly preferred is 0, ie virtually no ion exchange groups.

As a segment which does not have this ion exchange group substantially, the segment represented by the said General formula (3) is preferable.
Here, b, c, and d in the general formula (3) independently represent 0 or 1. n represents an integer of 5 or more, and is preferably 5 to 200. When the value of n is small, problems such as insufficient film formability and film strength and insufficient durability tend to occur. Therefore, n is particularly preferably 10 or more. In order to make n 5 or more, preferably 10 or more, it is sufficient to be 2000 or more, preferably 3000 or more, expressed in terms of polystyrene-equivalent number average molecular weight in the block of the general formula (3).

Moreover, Ar < ³ >, Ar < ⁴ >, Ar < ⁵ > and Ar < ⁶ > in General formula (3) may have a fluorine atom, the C1-C20 alkyl group which may have a substituent, and a substituent. An alkoxy group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms which may have a substituent, an aryloxy group having 6 to 20 carbon atoms which may have a substituent, or a substituent; It is a divalent aromatic group which may be substituted with an optionally substituted acyl group having 2 to 20 carbon atoms, and is particularly preferably a monocyclic aromatic group. Examples of such monocyclic aromatic groups include a 1,3-phenylene group and a 1,4-phenylene group. Here, an alkyl group which may have a substituent, an alkoxy group which may have a substituent, an aryl group which may have a substituent, an aryloxy which may have a substituent Examples of the acyl group which may have a group and a substituent are the same as those exemplified as the substituent of Ar ¹ above.

Z and Z ′ in the general formula (3) each independently represent an oxygen atom or a sulfur atom. Y and Y ′ in the general formula (3) each independently represent a direct bond or a divalent group. Among them, —CO— (carbonyl group), —SO ₂ — (sulfonyl group), _{-C (CH 3) 2 - (} 2,2- isopropylidene _{group), - C (CF 3)} 2 - (1,1,1,3,3,3- hexafluoro-2,2-propylidene group) or A 9,9-fluorenediyl group is preferred.

Preferable representative examples of the segment represented by the general formula (3) include the following. In addition, n is the same definition as the said General formula (3).

The block copolymer has the segment represented by the general formula (2) as a segment having an ion exchange group. The amount of the ion exchange group introduced into the block copolymer is the ion exchange capacity, that is, the block copolymer. When expressed in terms of ion exchange group equivalent per total weight of the polymer, 0.5 meq / g to 4.0 meq / g is preferable, and 1.0 meq / g to 3.0 meq / g is more preferable.
It is preferable that the ion exchange capacity is 0.5 meq / g or more because proton conductivity becomes higher and functions as a polymer electrolyte for a fuel cell are more excellent. On the other hand, when the ion exchange capacity indicating the amount of ion exchange groups introduced is 4.0 meq / g or less, the water resistance becomes better, which is preferable.

  In addition, the polymer of the present invention has a molecular weight of preferably 5,000 to 1,000,000, particularly preferably 15,000 to 400,000, in terms of polystyrene-reduced number average molecular weight.

Next, a preferred production method for obtaining the polymer of the present invention will be described.
Here, the method for introducing an ion exchange group is a method for polymerizing a monomer having an ion exchange group in advance, but after producing a polymer from a monomer having a site capable of introducing an ion exchange group, It may be a method of introducing an ion exchange group into the introduceable site. Among these, the former method is more preferable because the amount of ion exchange groups introduced and the substitution position can be accurately controlled. In addition, the aromatic group Ar ¹ adjacent to the electron-withdrawing group X tends to hardly cause electrophilic reaction such as sulfonation. Therefore, it is preferable to use a monomer that previously derives the structural unit represented by the general formula (1a) together with an electron-withdrawing group X and an ion-exchange group or a group that can be easily converted into an ion-exchange group. .

（式中、Ａｒ⁰、Ａｒ¹、Ｘおよびａ１は前記と同義である。Ｑは縮合反応時に脱離する基を表す。複数あるＡｒ⁰は互いに同一でも異なっていてもよく、２つのＡｒ¹は互いに同一でも異なっていてもよく、２つのａ１は互いに同一でも異なっていてもよく、２つのＱは互いに同一であっても異なっていてもよい。） As a method for producing the polymer of the present invention using a monomer having an ion exchange group, for example, in the presence of a zero-valent transition metal complex, a monomer represented by the following general formula (5a) is polymerized by a condensation reaction. Can be manufactured.

(Wherein, Ar ^0, Ar ^1, X and a1 is .Q the same meaning as defined above may be different in. Plurality of Ar ⁰ is each represents a group that departs during the condensation reaction, two Ar ¹ May be the same as or different from each other, two a1s may be the same or different from each other, and two Qs may be the same or different from each other.)

（式中、Ａｒ¹、ＸおよびＱは前記と同義である。２つのＱは互いに同一であっても異なっていてもよい。）
下記一般式（５ｃ）で表されるモノマーと、

（式中、Ａｒ⁰およびＱは前記と同義である。２つのＱは互いに同一であっても異なっていてもよい。）
を共重合すれば、下記一般式（１ｂ）で表される構造単位と一般式（１ｃ）で表される構造単位とを有し、Ａ¹とＡ⁰が直接結合で連結された構造を有するポリマー、すなわち一般式（１ａ）で表される構造単位を有するポリマーが得られる。

（式中、Ａｒ¹およびＸは前記と同義であり、２つのＡｒ¹は互いに同一でも異なっていてもよい。）

（式中、Ａｒ⁰は前記と同義である。） Or a monomer represented by the following general formula (5b);

(In the formula, Ar ¹ , X and Q are as defined above. Two Qs may be the same or different from each other.)
A monomer represented by the following general formula (5c);

(In the formula, Ar ⁰ and Q are as defined above. Two Qs may be the same or different from each other.)
Is copolymerized with a structural unit represented by the following general formula (1b) and a structural unit represented by the general formula (1c), wherein A ¹ and A ⁰ are linked by a direct bond. A polymer, that is, a polymer having a structural unit represented by the general formula (1a) is obtained.

(In the formula, Ar ¹ and X are as defined above, and two Ar ^{1 s} may be the same as or different from each other.)

(In the formula, Ar ⁰ has the same meaning as described above.)

（式中、Ａｒ¹、Ｘ、Ｑおよびｆは前記と同義である。２つのＱは互いに同一であっても異なっていてもよく、２つのｆは互いに同一であっても異なっていてもよく、２つ以上あるＡｒ¹は互いに同一であっても異なっていてもよい。）
また、上記一般式（５）で表されるモノマーと、上記一般式（５ｃ）で表されるモノマーとを縮合反応により重合することもできる。 In order to obtain a polymer composed of the structural unit represented by the general formula (1), which is a preferred polymer of the present invention, for example, a monomer represented by the following general formula (5) may be polymerized by a condensation reaction. .

(Wherein Ar ¹ , X, Q and f are as defined above. Two Qs may be the same or different from each other, and two f may be the same or different from each other. Two or more Ar ^{1 s} may be the same or different.
Moreover, the monomer represented by the general formula (5) and the monomer represented by the general formula (5c) can be polymerized by a condensation reaction.

（式中、Ａｒ³、Ａｒ⁴、Ａｒ⁵、Ａｒ⁶、ｂ、ｃ、ｄ、ｎ、Ｙ、Ｙ’、Ｚ、Ｚ’、Ｑは前記と同義である。） Moreover, when manufacturing said suitable block copolymer, it represents with the monomer represented by the said General formula (5), and the following general formula (6) in coexistence of a zerovalent transition metal complex, for example. A method of polymerizing a segment precursor that does not substantially have an ion exchange group (hereinafter sometimes abbreviated as “segment precursor”) by a condensation reaction, or in the coexistence of a zero-valent transition metal complex A method of polymerizing a monomer represented by the formula (5) to obtain a precursor for deriving a segment represented by the general formula (2), and condensing the precursor with a compound represented by the following general formula (6) Is exemplified.

(In the formula, Ar ³ , Ar ⁴ , Ar ⁵ , Ar ⁶ , b, c, d, n, Y, Y ′, Z, Z ′, and Q are as defined above.)

（Ｒ^aおよびＲ^bは、互いに独立に水素原子または有機基を表し、Ｒ^aとＲ^bとが結合して環を形成していてもよい。） Q in the general formulas (5), (5a), (5b), (5c) and (6) represents a group which is eliminated during the condensation reaction. Specific examples thereof include, for example, a chlorine atom and a bromine atom. And halogen atoms such as iodine atom, p-toluenesulfonyloxy group, methanesulfonyloxy group, trifluoromethanesulfonyloxy group, groups containing boron atoms as shown below, and the like.

(R ^a and R ^b each independently represent a hydrogen atom or an organic group, and R ^a and R ^b may be bonded to form a ring.)

Hereinafter, the manufacturing method of the block copolymer which is a suitable polymer of this invention is explained in full detail.
When the monomer represented by the general formula (5) is exemplified by a sulfonic acid group which is a preferable ion exchange group, 4,4′-dichloro-2, 2′-disulfobenzophenone and 4,4′-dibromo-2 are exemplified. 2′-disulfobenzophenone, 4,4′-dichloro-3, 3′-disulfobenzophenone, 4,4′-dibromo-3, 3′-disulfobenzophenone, 5,5′-dichloro-3, 3 '-Disulfobenzophenone, 5,5'-dibromo-3,3'-disulfobenzophenone, bis (4-chloro-2-sulfophenyl) sulfone, bis (4-bromo-2-sulfophenyl) sulfone, bis ( 4-chloro-3-sulfophenyl) sulfone, bis (4-bromo-3-sulfophenyl) sulfone, bis (5-chloro-3-sulfophenyl) sulfone, bis (5-bromo-3-sulfone) Eniru) such as sulfone.
In the case of other ion exchange groups, the sulfonic acid groups of the monomers exemplified above can be selected by replacing them with ion exchange groups such as carboxyl groups and phosphonic acid groups, and these other ion exchange groups can be selected. The monomer having it can be easily obtained from the market or can be produced by using a known production method.
Further, the ion exchange group of the monomer exemplified above may be protected with a salt form or a protecting group. In particular, it is possible to use a monomer in which the ion exchange group is protected with a salt form or a protecting group. From the viewpoint of sex. As a salt form, an alkali metal salt is preferable, and a Li salt, a Na salt, and a K salt are particularly preferable.

（式中、Ａｒ⁷はイオン交換基を導入することで、上記一般式（１）のＡｒ¹となり得る２価の芳香族基を表し、Ｑ、Ｘ、ｆは前記と同義である。）
また、本発明のブロック共重合体の製造を行う方法としては、例えば、ゼロ価遷移金属錯体の共存下、上記一般式（７）で表されるモノマーと、イオン交換基を有さないモノマーの代わりに、上記一般式（６）で表されるイオン交換基を実質的に有さないセグメントの前駆体を縮合反応により共重合し、その後、公知の方法に準じてイオン交換性基を導入することにより製造し得る。 In addition, as a method for carrying out the introduction of ion exchange groups after polymerization and producing the copolymer of the present invention, for example, in the presence of a zero-valent transition metal complex, a monomer represented by the following general formula (7), If necessary, a monomer having no ion exchange group may be copolymerized by a condensation reaction, and then introduced by introducing an ion exchange group according to a known method.

(In the formula, Ar ⁷ represents a divalent aromatic group capable of becoming Ar ^{1 in the} general formula (1) by introducing an ion exchange group, and Q, X, and f are as defined above.)
Moreover, as a method for producing the block copolymer of the present invention, for example, in the presence of a zero-valent transition metal complex, a monomer represented by the general formula (7) and a monomer having no ion exchange group are used. Instead, a precursor of a segment substantially having no ion exchange group represented by the general formula (6) is copolymerized by a condensation reaction, and then an ion exchange group is introduced according to a known method. Can be manufactured.

Here, Ar ⁷ is a fluorine atom, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, or 2 carbon atoms. Ar ⁷ is a divalent monocyclic aromatic group having a structure capable of introducing at least one ion-exchange group, although it may be substituted with ˜20 acyl groups. Examples of the divalent monocyclic aromatic group include a 1,3-phenylene group and a 1,4-phenylene group. C1-C20 alkyl group which may have a substituent, C1-C20 alkoxy group which may have a substituent, C6-C20 which may have a substituent As the aryl group, an aryloxy group having 6 to 20 carbon atoms which may have a substituent or an acyl group having 2 to 20 carbon atoms which may have a substituent, the above-described substituent for Ar ¹ Are the same as those exemplified above.

As the structure into which an ion exchange group in Ar ⁷ can be introduced, it indicates that it has a hydrogen atom directly bonded to an aromatic ring or a substituent that can be converted into an ion exchange group. The substituent that can be converted into an ion exchange group is not particularly limited as long as it does not inhibit the polymerization reaction, and examples thereof include a mercapto group, a methyl group, a formyl group, a hydroxy group, and a bromo group. In the case of an electrophilic substitution reaction such as introduction of a group, a hydrogen atom bonded to an aromatic ring can also be regarded as a substituent that can be converted into an ion exchange group. Specific examples of the monomer represented by the general formula (7) include 3,3′-dichlorobenzophenone, 3,3′-dibromobenzophenone, 4,4′-dichlorobenzophenone, and 4,4′-dibromobenzophenone. , Bis (3-chlorophenyl) sulfone, bis (3-bromophenyl) sulfone, bis (4-chlorophenyl) sulfone, bis (4-bromophenyl) sulfone can be converted into the ion-exchange groups exemplified above And those having various substituents.

  As an example of a method for introducing an ion exchange group, in the case of a sulfonic acid group, a copolymer obtained by polymerization is dissolved or dispersed in concentrated sulfuric acid, or after being at least partially dissolved in an organic solvent. And a method of converting a hydrogen atom into a sulfonic acid group by reacting concentrated sulfuric acid, chlorosulfuric acid, fuming sulfuric acid, sulfur trioxide and the like.

  When the monomer represented by the general formula (7) has a mercapto group, a copolymer having a mercapto group can be obtained at the end of the polymerization reaction, and the mercapto group is converted into a sulfonic acid group by an oxidation reaction. can do. During the condensation reaction, the mercapto group is preferably protected with a protecting group.

  Next, as an example of a method for introducing a carboxyl group, a method for converting a methyl group or a formyl group into a carboxyl group by an oxidation reaction, or a method for converting a bromo group to -MgBr by the action of Mg and then allowing carbon dioxide to act. Known methods such as conversion to a carboxyl group can be mentioned.

  Taking the phosphonic acid group introduction method as an example, the bromo group is reacted with a trialkyl phosphite in the presence of a nickel compound such as nickel chloride to form a phosphonic acid diester group, which is then hydrolyzed to produce phosphonic acid. In the presence of Lewis acid catalyst in the coexistence of acid group, and forming a CP bond using phosphorus trichloride, phosphorus pentachloride, etc., then converted to phosphonic acid group by oxidation and hydrolysis as necessary And a known method such as a method of converting a hydrogen atom into a phosphonic acid group by reacting phosphoric anhydride at a high temperature.

  Taking a method for introducing a sulfonimide group as an example, a known method such as a method for converting the above-described sulfonic acid group into a sulfonimide group by a condensation reaction or a substitution reaction may be mentioned.

In this way, from a monomer having a substituent that can be converted into an ion exchange group, or a polymer having a substituent that can be converted into an ion exchange group obtained by polymerizing the monomer, the substituent is converted into an ion exchange group. Thus, the polymer of the present invention can also be produced, but as described above, when the introduction of the ion exchange group is an electrophilic substitution reaction, Ar ⁷ adjacent to X is relatively less susceptible to the electrophilic substitution reaction. Therefore, it is preferable to introduce the ion exchange group by means other than using an electrophilic substitution reaction.

Next, suitable representative examples of the segment precursor represented by the general formula (6) will be given. In these examples, Q is as defined above.

かかる例示の化合物は、市場から容易に入手できるか、市場から容易に入手できる原料を用いて製造することが可能であり、例えば、上記（６ａ）で示される末端に脱離基Ｑを有するポリエーテルスルホンは、住友化学（株）製スミカエクセルＰＥＳなどの市販品を入手することも可能であり、これを一般式（６）で表されるセグメント前駆体として用いることもできる。また、ｎは上記と同義であり、これらの化合物のポリスチレン換算数平均分子量で２０００以上、好ましくは３０００以上であるものが選択される。

Such exemplary compounds can be easily obtained from the market, or can be produced using raw materials that are easily available from the market. For example, a polyvalent compound having a leaving group Q at the terminal represented by (6a) above can be used. Ethersulfone can be obtained from commercial products such as Sumika Excel PES manufactured by Sumitomo Chemical Co., Ltd., and can be used as a segment precursor represented by the general formula (6). Moreover, n is synonymous with the above, The thing of 2000 or more by the polystyrene conversion number average molecular weight of these compounds, Preferably 3000 or more are selected.

Polymerization by the condensation reaction is carried out in the presence of a zero-valent transition metal complex.
The zero-valent transition metal complex is a transition metal in which a halogen or a ligand described below is coordinated, and preferably has at least one ligand described below. As the zero-valent transition metal complex, either a commercially available product or a separately synthesized one may be used.
Examples of the method for synthesizing the zero-valent transition metal complex include known methods such as a method of reacting a transition metal salt or transition metal oxide with a ligand. The synthesized zero-valent transition metal complex may be used after being taken out, or may be used in situ without being taken out.
Examples of the ligand include acetate, acetylacetonate, 2,2′-bipyridyl, 1,10-phenanthroline, methylenebisoxazoline, N, N, N′N′-tetramethylethylenediamine, triphenylphosphine, and tolylphosphine. , Tributylphosphine, triphenoxyphosphine, 1,2-bisdiphenylphosphinoethane, 1,3-bisdiphenylphosphinopropane, and the like.

Examples of the zero-valent transition metal complex include a zero-valent nickel complex, a zero-valent palladium complex, a zero-valent platinum complex, and a zero-valent copper complex. Among these transition metal complexes, a zero-valent nickel complex and a zero-valent palladium complex are preferably used, and a zero-valent nickel complex is more preferably used.
Examples of the zerovalent nickel complex include bis (1,5-cyclooctadiene) nickel (0), (ethylene) bis (triphenylphosphine) nickel (0), tetrakis (triphenylphosphine) nickel, among others. Bis (1,5-cyclooctadiene) nickel (0) is preferably used from the viewpoints of reactivity, polymer yield, and polymer high molecular weight.
Examples of the zero-valent palladium complex include tetrakis (triphenylphosphine) palladium (0).
These zerovalent transition metal complexes may be synthesized and used as described above, or commercially available products may be used.
Examples of the method for synthesizing the zero-valent transition metal complex include known methods such as a method in which the transition metal compound is made zero-valent with a reducing agent such as zinc or magnesium. The synthesized zero-valent transition metal complex may be taken out and used in situ without being taken out.

When a zero-valent transition metal complex is generated from a transition metal compound by a reducing agent, a divalent transition metal compound is usually used as the transition metal compound to be used, but a zero-valent one can also be used. Of these, divalent nickel compounds and divalent palladium compounds are preferred. Examples of the divalent nickel compound include nickel chloride, nickel bromide, nickel iodide, nickel acetate, nickel acetylacetonate, nickel chloride bis (triphenylphosphine), nickel bromide bis (triphenylphosphine), nickel iodide bis ( Triphenylphosphine) and the like, and examples of the divalent palladium compound include palladium chloride, palladium bromide, palladium iodide, palladium acetate and the like.
Examples of the reducing agent include zinc, magnesium, sodium hydride, hydrazine and derivatives thereof, and lithium aluminum hydride. If necessary, ammonium iodide, trimethylammonium iodide, triethylammonium iodide, lithium iodide, sodium iodide, potassium iodide and the like can be used in combination.

In the condensation reaction using the transition metal complex, it is preferable to add a compound that can be a ligand of the zero-valent transition metal complex used from the viewpoint of improving the yield of the polymer. The compound to be added may be the same as or different from the ligand of the transition metal complex used.
Examples of the compound that can be used as the ligand include the compounds exemplified as the ligand described above. Generality, low cost, condensing agent reactivity, polymer yield, polymer high molecular weight And triphenylphosphine and 2,2′-bipyridyl are preferred. In particular, 2,2′-bipyridyl is preferable because it can improve the yield of the polymer and increase the molecular weight of the polymer when combined with bis (1,5-cyclooctadiene) nickel (0). used. The added amount of the ligand is usually about 0.2 to 10 mol times, preferably about 1 to 5 mol times based on the transition metal atom, relative to the zero-valent transition metal complex.

The amount of the zero-valent transition metal complex used is such that the compound represented by the above general formula (5) and / or the compound represented by the above general formula (7) is copolymerized with other monomers and / or the above as necessary. It is 0.1 mol times or more with respect to the total molar amount of the precursor represented by the general formula (6) (hereinafter referred to as “total molar amount of all monomers”). If the amount used is too small, the molecular weight tends to be small, so the amount is preferably 1.5 mol times or more, more preferably 1.8 mol times or more, and even more preferably 2.1 mol times or more. The upper limit of the amount used is not particularly limited, but if the amount used is too large, the post-treatment tends to be complicated, and therefore it is preferably 5.0 moles or less.
In addition, when synthesizing a zero-valent transition metal complex from a transition metal compound using a reducing agent, the zero-valent transition metal complex to be produced may be set so as to fall within the above range. What is necessary is just to be 0.01 mol times or more with respect to the total molar amount of a monomer, Preferably it is 0.03 mol times or more. The upper limit of the amount used is not limited, but if the amount used is too large, the post-treatment tends to become complicated, and therefore it is preferably 5.0 moles or less. Moreover, the usage-amount of a reducing agent should just be 0.5 mol times or more with respect to the total molar amount of all the monomers, Preferably it is 1.0 mol times or more. The upper limit of the amount used is not limited, but if the amount used is too large, the post-treatment tends to be complicated, and therefore it is preferably 10 mol times or less.

The reaction temperature is usually in the range of 0 to 250 ° C. In order to further increase the molecular weight of the polymer to be produced, the zero-valent transition metal complex and the compound represented by the above general formula (5) and / or the above It is preferable to mix the compound represented by the general formula (7) with other monomers copolymerized as necessary and / or the precursor represented by the general formula (6) at a temperature of 45 ° C. or higher. A preferable mixing temperature is usually 45 ° C to 200 ° C, and particularly preferably about 50 ° C to 100 ° C. Zero-valent transition metal complex, compound represented by the above general formula (5) and / or compound represented by the above general formula (7) and optionally a monomer having no ion exchange group and / or the above general formula (6) ) And then the precursor is usually reacted at about 45 ° C. to 200 ° C., preferably about 50 ° C. to 100 ° C. The reaction time is usually about 0.5 to 24 hours.
In addition, the zero-valent transition metal complex, the compound represented by the above general formula (5) and / or the other monomer that is copolymerized with the compound represented by the above general formula (7) as necessary, and / or the above general formula ( The method of mixing the precursor shown in 6) may be a method of adding one to the other or a method of adding both to the reaction vessel at the same time. When adding, it may be added all at once, but it is preferable to add little by little in consideration of heat generation, and it is also preferable to add in the presence of a solvent.

  These condensation reactions are usually carried out in the presence of a solvent. Examples of such solvents include aprotic such as N, N-dimethylformamide (DMF), N, N-dimethylacetamide (DMAc), N-methylpyrrolidone (NMP), dimethyl sulfoxide (DMSO), hexamethylphosphoric triamide, and the like. Polar solvent. Aromatic hydrocarbon solvents such as toluene, xylene, mesitylene, benzene, and n-butylbenzene. Ether solvents such as tetrahydrofuran, 1,4-dioxane, dibutyl ether, tert-butyl methyl ether, dimercaptoethane, diphenyl ether. Ester solvents such as ethyl acetate, butyl acetate, and methyl benzoate. Examples thereof include alkyl halide solvents such as chloroform and dichloroethane. In addition, the description in parenthesis shows the abbreviation of a solvent, and this abbreviation may be used in the description mentioned later.

In order to increase the molecular weight of the polymer to be generated, it is desirable that the polymer is sufficiently dissolved. Therefore, tetrahydrofuran, 1,4-dioxane, DMF, DMAc, NMP, DMSO, which are good solvents for the polymer, are used. Toluene is preferred. These may be used in combination of two or more. Of these, DMF, DMAc, NMP, DMSO, and a mixture of two or more of these are preferably used.
The amount of the solvent is not particularly limited, but if the concentration is too low, it may be difficult to recover the produced polymer compound, and if the concentration is too high, stirring may be difficult. The compound represented by the general formula (5) and / or the compound represented by the general formula (7), and other monomers copolymerized as necessary and / or the precursor represented by the general formula (6). The solvent amount is preferably 99.95 to 50% by weight, more preferably 99.9 to 75% by weight, when the total amount is 100% by weight.

Thus, the polymer of the present invention, particularly a preferred block copolymer, can be obtained, and a conventional method can be applied to take out the produced copolymer from the reaction mixture. For example, the polymer can be precipitated by adding a poor solvent, and the target product can be taken out by filtration or the like. Moreover, it can also refine | purify with a normal purification method, such as washing with water and reprecipitation using a good solvent and a poor solvent, as needed.
Further, when the sulfonic acid group of the produced polymer is in the form of a salt, it is preferable to convert the sulfonic acid group into a free acid form for use as a member for a fuel cell. It is possible by washing with an acidic solution. Examples of the acid used include hydrochloric acid, sulfuric acid, and nitric acid, and dilute hydrochloric acid and dilute sulfuric acid are preferable.
As described above, the case where the polymer of the present invention is a block copolymer has been described in detail. Polymerization of the monomer represented by the general formula (5a), the monomer represented by the general formula (5b), and The copolymerization of the monomer represented by the general formula (5c) or the polymerization of the monomer represented by the general formula (5) can be easily carried out with reference to this production method.

Hereinafter, typical examples of suitable block copolymers will be exemplified. In addition, the segment which has an ion exchange group is illustrated as a segment which consists of the above-mentioned suitable structural unit.

かかるブロック共重合体の具体例は、上記一般式（２）で表されるイオン交換基を有するブロックと、上記一般式（３）で表されるブロックとが直接結合している形態で例示したが、適切な原子または原子団を介して結合している形態であってもよい。また、かかるブロック共重合体の具体例において、イオン交換基を有するブロックが

で表される構造単位に加え、

とを有するポリアリーレン系ブロックであってもよい。

Specific examples of such a block copolymer are exemplified in the form in which the block having the ion exchange group represented by the general formula (2) and the block represented by the general formula (3) are directly bonded. May be bonded via an appropriate atom or atomic group. Further, in a specific example of such a block copolymer, a block having an ion exchange group is

In addition to the structural unit represented by

It may be a polyarylene block having

Any of the polymers of the present invention shown above can be suitably used as a member for a fuel cell.
The polymer of the present invention is preferably used as an ion conductive membrane of an electrochemical device such as a fuel cell, particularly as a proton conductive membrane in those having acid groups which are suitable ion exchange groups. In the following description, the case of the proton conductive membrane will be mainly described.
In this case, the polymer of the present invention is usually used in the form of a membrane. Although there is no restriction | limiting in particular in the method (film forming method) converted into a film | membrane, It is preferable to form into a film using the method (solution casting method) formed into a film from a solution state.
Specifically, the polymer of the present invention is dissolved in an appropriate solvent, the solution is cast on 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 the copolymer of the present invention can be dissolved and can be removed thereafter, and is an aprotic polar solvent such as DMF, DMAc, NMP, DMSO, or the like. Chlorinated solvents such as dichloromethane, chloroform, 1,2-dichloroethane, chlorobenzene, dichlorobenzene, alcohols such as methanol, ethanol, propanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl An alkylene glycol monoalkyl ether such as ether is preferably used. These can be used singly, but two or more solvents can be mixed and used as necessary. Among them, DMSO, DMF, DMAc, and NMP are preferable because of high polymer solubility.

  Although there is no restriction | limiting in particular in the thickness of a film | membrane, 10-300 micrometers is preferable. A film having a film thickness of 10 μm or more is preferable because practical strength is more excellent, and a film having a film thickness of 300 μm or less is preferable because the film resistance is decreased and the characteristics of the electrochemical device tend to be further improved. The film thickness can be controlled by the concentration of the solution and the coating thickness on the substrate.

In addition, for the purpose of improving various physical properties of the film, plasticizers, stabilizers, release agents and the like used in ordinary polymers can be added to the copolymer of the present invention. In addition, other polymers can be combined with the copolymer of the present invention by a method such as mixing and casting in the same solvent.
Furthermore, in order to facilitate water management in fuel cell applications, it is also known to add inorganic or organic fine particles as a water retention agent. 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 also be crosslinked by irradiating with an electron beam or radiation.

In order to further improve the strength, flexibility and durability of the proton conductive membrane using the polymer electrolyte containing the polymer of the present invention as an active ingredient, a polymer electrolyte containing the copolymer of the present invention as an active ingredient is used. It is also possible to form a composite film by impregnating a porous base material to form a composite. A known method can be used as the compounding method.
The porous substrate is not particularly limited as long as it satisfies the above-mentioned purpose of use, and examples thereof include porous membranes, woven fabrics, nonwoven fabrics, fibrils and the like, and they can be used regardless of their shapes and materials. As the material for the porous substrate, an aliphatic polymer, an aromatic polymer, or a fluorine-containing polymer is preferable from the viewpoint of heat resistance and the effect of reinforcing physical strength.

When the polymer electrolyte composite membrane using the polymer of the present invention is used as a proton conductive membrane of a polymer electrolyte fuel cell, the thickness of the porous substrate is preferably 1 to 100 μm, more preferably 3 to 30 μm, Particularly preferably, it is 5 to 20 μm, the pore diameter of the porous substrate is preferably 0.01 to 100 μm, more preferably 0.02 to 10 μm, and the porosity of the porous substrate is preferably 20 to 98. %, More preferably 40 to 95%.
When the film thickness of the porous substrate is 1 μm or more, the effect of reinforcing the strength after compounding or the reinforcing effect of imparting flexibility and durability is more excellent, and gas leakage (cross leak) is less likely to occur. . Further, when the film thickness is 100 μm or less, the electric resistance is further lowered, and the obtained composite membrane is more excellent as a proton conductive membrane of a polymer electrolyte fuel cell. When the pore diameter is 0.01 μm or more, filling of the copolymer of the present invention becomes easier, and when it is 100 μm or less, the reinforcing effect on the copolymer is further increased. When the porosity is 20% or more, the resistance as a proton conductive membrane becomes smaller, and when it is 98% or less, the strength of the porous substrate itself becomes larger and the reinforcing effect is further improved, which is preferable.
Further, the polymer electrolyte composite membrane and the polymer electrolyte membrane can be laminated and used as a proton conductive membrane of a fuel cell.

Next, the fuel cell of the present invention will be described.
The fuel cell of the present invention can be produced by bonding a catalyst and a conductive material as a current collector to both surfaces of a polymer electrolyte membrane containing the polymer of the present invention.
Here, 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 or platinum alloy fine particles are used as a catalyst component. Is preferred. The fine particles of platinum or platinum-based alloys are often used by being supported on particulate or fibrous carbon such as activated carbon or graphite.
Further, platinum or platinum-based alloy supported on carbon is mixed with an alcohol solution of a perfluoroalkylsulfonic acid resin as a polymer electrolyte to form a paste, and a gas diffusion layer and / or a polymer electrolyte membrane and / or Or a catalyst layer is obtained by apply | coating and drying to a polymer electrolyte composite film. As a specific method, for example, J. Org. Electrochem. Soc. : Known methods such as those described in Electrochemical Science and Technology, 1988, 135 (9), 2209 can be used.
Here, instead of the perfluoroalkylsulfonic acid resin as the polymer electrolyte, a polymer electrolyte containing the polymer of the present invention as an active ingredient can be used as a catalyst composition, and the catalyst composition can be obtained using this catalyst composition. The obtained catalyst layer is suitable as the catalyst layer because it has excellent proton conductivity of the copolymer of the present invention and dimensional stability related to water absorption.
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.
The fuel cell of the present invention thus produced can be used in various forms using hydrogen gas, reformed hydrogen gas, and methanol as fuel.

  A polymer electrolyte fuel cell comprising the polymer of the present invention thus obtained in a proton conducting membrane and / or a catalyst layer is excellent in power generation performance and can be provided as a long-life fuel cell.

  While 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 below with reference to examples, but the present invention is not limited to these examples.
Molecular weight measurement:
The number average molecular weight (Mn) and weight average molecular weight (Mw) in terms of polystyrene were measured by gel permeation chromatography (GPC) under the following conditions. In addition, as conditions for analysis of the GPC, the following conditions were used, and conditions used for molecular weight measurement values were added.
Conditions GPC measurement device Prominence GPC system column manufactured by Shimadzu Corporation Column TSKgel GMH _HR-M manufactured by Tosoh Corporation
Column temperature 40 ° C
Mobile phase solvent DMF (LiBr added to 10 mmol / dm ³ )
Solvent flow rate 0.5mL / min

Measurement of water absorption:
The dried membrane was weighed and the water absorption was calculated from the increase in membrane weight after being immersed in deionized water at 80 ° C. for 2 hours, and the ratio to the dried membrane was determined.

Measurement of ion exchange capacity (IEC):
Determined by titration method.

Measurement of proton conductivity:
It measured by the alternating current method.

Dimensional change rate during water absorption swelling:
The dimension (Ld) in the surface direction of the film dried at 23 ° C. and 50% relative humidity, and the dimension (Lw) in the surface direction of the film immediately after the film was immersed and swollen in 80 ° C. hot water for 1 hour or more. ) Was measured and calculated as follows.
Dimensional change rate [%] = (Lw−Ld) ÷ Ld × 100 [%]

（住友化学製スミカエクセルＰＥＳ５２００Ｐ、Ｍｎ＝３．６×１０⁴、Ｍｗ＝８．１×１０⁴）２．３ｇ、２，２’−ビピリジル５．９ｇ(３７．８ｍｍｏｌ) を入れて攪拌した。その後バス温を１５０℃まで昇温し、トルエンを加熱留去することで系内の水分を共沸脱水した後、６５℃に冷却した。次いで、これにビス（１，５−シクロオクタジエン）ニッケル（０）１０．３ｇ(３７．４ｍｍｏｌ)を加え、内温７５℃で５時間攪拌した。放冷後、反応液を大量のメタノールに注ぐことによりポリマーを析出させ濾別。その後６ｍｏｌ／Ｌ塩酸による洗浄・ろ過操作を数回繰り返した後、濾液のｐＨが５を越えるまで水洗を行い、得られた粗ポリマーを乾燥した。その後、粗ポリマーをＮＭＰに溶解し、６ｍｏｌ／Ｌ塩酸に注ぐことにより、再沈殿精製を行い、濾液のｐＨが５を越えるまで水洗を行った後、得られたポリマーを減圧乾燥することにより目的とする下記ブロック共重合体３．０ｇを得た。分子量測定結果を下記に示す。

得られたブロック共重合体を１０重量％の濃度でＮＭＰに溶解し、高分子電解質溶液を調整した。その後、得られた高分子電解質溶液をガラス板上に流延塗布し、常圧下、８０℃で２時間乾燥させる事により溶媒を除去した後、塩酸処理、イオン交換水での洗浄を経て、膜厚約４０μｍの高分子電解質膜を作製した。吸水率、ＩＥＣおよび寸法変化率の結果を下記に示す。
Ｍｎ １．３×１０⁵
Ｍｗ ２．４×１０⁵
吸水率 ７６％
ＩＥＣ １．６２ ｍｅｑ／ｇ
寸法変化率 ３．５％
使用した末端クロロ型であるポリエーテルスルホンのポリスチレン換算のＭｎを基準に、得られたブロック共重合体のＭｎ及びＩＥＣから見積もると、ｍは平均４０と算出される。
得られた高分子電解質膜のプロトン伝導度を測定した。温度を５０℃とし、湿度を９０％ＲＨ、６０％ＲＨ、４０％ＲＨとしたときのプロトン伝導度を表１に、湿度を９０％ＲＨとし、温度を９０℃、７０℃、５０℃としたときのプロトン伝導度を表２に示す。 Example 1
In a flask equipped with an azeotropic distillation apparatus under an argon atmosphere, DMSO 130 mL, toluene 60 mL, 3,3′-disulfo-4,4′-dichlorodiphenylsulfone dipotassium salt 8.1 g (15.5 mmol), terminal chloro type The following polyethersulfone

(Sumitomo Chemical Sumika Excel PES5200P, Mn = 3.6 × 10 ⁴ , Mw = 8.1 × 10 ⁴ ) 2.3 g and 2,2′-bipyridyl 5.9 g (37.8 mmol) were added and stirred. Thereafter, the bath temperature was raised to 150 ° C., and the water in the system was azeotropically dehydrated by distilling off toluene, followed by cooling to 65 ° C. Next, 10.3 g (37.4 mmol) of bis (1,5-cyclooctadiene) nickel (0) was added thereto, and the mixture was stirred at an internal temperature of 75 ° C. for 5 hours. After allowing to cool, the reaction solution is poured into a large amount of methanol to precipitate a polymer, which is filtered off. Thereafter, washing and filtration operations with 6 mol / L hydrochloric acid were repeated several times, followed by washing with water until the pH of the filtrate exceeded 5, and the resulting crude polymer was dried. Thereafter, the crude polymer was dissolved in NMP and poured into 6 mol / L hydrochloric acid for reprecipitation purification, washed with water until the pH of the filtrate exceeded 5, and then the obtained polymer was dried under reduced pressure. As a result, 3.0 g of the following block copolymer was obtained. The molecular weight measurement results are shown below.

The obtained block copolymer was dissolved in NMP at a concentration of 10% by weight to prepare a polymer electrolyte solution. Thereafter, the obtained polymer electrolyte solution was cast-coated on a glass plate, and the solvent was removed by drying at 80 ° C. for 2 hours under normal pressure, followed by treatment with hydrochloric acid and washing with ion-exchanged water to obtain a membrane. A polymer electrolyte membrane having a thickness of about 40 μm was produced. The results of water absorption, IEC and dimensional change are shown below.
Mn 1.3 × 10 ⁵
Mw 2.4 × 10 ⁵
Water absorption 76%
IEC 1.62 meq / g
Dimensional change rate 3.5%
Based on the polystyrene equivalent Mn of the polyether sulfone used as the terminal chloro type, based on Mn and IEC of the obtained block copolymer, m is calculated as 40 on average.
The proton conductivity of the obtained polymer electrolyte membrane was measured. The proton conductivity when the temperature is 50 ° C. and the humidity is 90% RH, 60% RH, and 40% RH is shown in Table 1, the humidity is 90% RH, and the temperatures are 90 ° C., 70 ° C., and 50 ° C. The proton conductivity is shown in Table 2.

アルゴン雰囲気下、共沸蒸留装置を備えたフラスコに、ＤＭＳＯ１００ｍＬ、トルエン５０ｍＬ、３，３’−ジスルホ−４，４’−ジクロロジフェニルスルホン二ナトリウム塩３．１ｇ（６．４ｍｍｏｌ）、２，５−ジクロロベンゾフェノン ３．８ｇ（１５．０ｍｍｏｌ）、２，２’−ビピリジル８．４ｇ(５３．８ｍｍｏｌ) を入れて攪拌した。その後バス温を１５０℃まで昇温し、トルエンを加熱留去することで系内の水分を共沸脱水した後、６５℃に冷却した。次いで、これにビス（１，５−シクロオクタジエン）ニッケル（０）１４．７ｇ(５３．４ｍｍｏｌ)を加え、内温７０℃で３時間攪拌した。放冷後、反応液を大量のメタノールに注ぐことによりポリマーを析出させ濾別。その後６ｍｏｌ／Ｌ塩酸による洗浄・ろ過操作を数回繰り返した後、濾液のｐＨが５を越えるまで水洗を行い、得られた粗ポリマーを乾燥した。その後、粗ポリマーをＮＭＰに溶解し、６ｍｏｌ／Ｌ塩酸に注ぐことにより、再沈殿精製を行い、濾液のｐＨが５を越えるまで水洗を行った後、得られたポリマーを減圧乾燥することにより目的とする下記共重合体３．０ｇを得た。分子量測定結果を下記に示す。

得られた共重合体を２０重量％の濃度でＮＭＰに溶解し、高分子電解質溶液を調整した。その後、得られた高分子電解質溶液をガラス板上に流延塗布し、常圧下、８０℃で２時間乾燥させる事により溶媒を除去した後、塩酸処理、イオン交換水での洗浄を経て、膜厚約４０μｍの高分子電解質膜を作製した。吸水率、ＩＥＣの結果を下記に示す。
Ｍｎ １．３×１０⁵
Ｍｗ ２．４×１０⁵
吸水率 １２５％
ＩＥＣ ２．３４ ｍｅｑ／ｇ
得られた高分子電解質膜のプロトン伝導度を測定した。温度を５０℃とし、湿度を９０％ＲＨ、６０％ＲＨ、４０％ＲＨとしたときのプロトン伝導度を表１に、湿度を９０％ＲＨとし、温度を９０℃、７０℃、５０℃としたときのプロトン伝導度を表２に示す。 Example 2

In a flask equipped with an azeotropic distillation apparatus under an argon atmosphere, DMSO 100 mL, toluene 50 mL, 3,3′-disulfo-4,4′-dichlorodiphenylsulfone disodium salt 3.1 g (6.4 mmol), 2,5- Dichlorobenzophenone 3.8 g (15.0 mmol) and 2,2′-bipyridyl 8.4 g (53.8 mmol) were added and stirred. Thereafter, the bath temperature was raised to 150 ° C., and the water in the system was azeotropically dehydrated by distilling off toluene, followed by cooling to 65 ° C. Next, 14.7 g (53.4 mmol) of bis (1,5-cyclooctadiene) nickel (0) was added thereto, and the mixture was stirred at an internal temperature of 70 ° C. for 3 hours. After allowing to cool, the reaction solution is poured into a large amount of methanol to precipitate a polymer, which is filtered off. Thereafter, washing and filtration operations with 6 mol / L hydrochloric acid were repeated several times, followed by washing with water until the pH of the filtrate exceeded 5, and the resulting crude polymer was dried. Thereafter, the crude polymer was dissolved in NMP and poured into 6 mol / L hydrochloric acid for reprecipitation purification, washed with water until the pH of the filtrate exceeded 5, and then the obtained polymer was dried under reduced pressure. As a result, 3.0 g of the following copolymer was obtained. The molecular weight measurement results are shown below.

The obtained copolymer was dissolved in NMP at a concentration of 20% by weight to prepare a polymer electrolyte solution. Thereafter, the obtained polymer electrolyte solution was cast-coated on a glass plate, and the solvent was removed by drying at 80 ° C. for 2 hours under normal pressure, followed by treatment with hydrochloric acid and washing with ion-exchanged water to obtain a membrane. A polymer electrolyte membrane having a thickness of about 40 μm was produced. The results of water absorption and IEC are shown below.
Mn 1.3 × 10 ⁵
Mw 2.4 × 10 ⁵
Water absorption rate 125%
IEC 2.34 meq / g
The proton conductivity of the obtained polymer electrolyte membrane was measured. The proton conductivity when the temperature is 50 ° C. and the humidity is 90% RH, 60% RH, and 40% RH is shown in Table 1, the humidity is 90% RH, and the temperatures are 90 ° C., 70 ° C., and 50 ° C. The proton conductivity is shown in Table 2.

Ｍｎ １．３×１０⁵
Ｍｗ ２．２×１０⁵
Example 3
In a flask equipped with an azeotropic distillation apparatus under an argon atmosphere, DMSO 200 mL, toluene 120 mL, 3,3′-disulfo-4,4′-dichlorodiphenylsulfone disodium salt 7.7 g (15.0 mmol), 2,5- 3.7 g (15.0 mmol) of dichlorobenzenesulfonic acid sodium salt, the following polyethersulfone which is terminal chloro type

Mn 1.3 × 10 ⁵
Mw 2.2 × 10 ⁵

  From Tables 1 and 2, the polymer of the present invention has good and low proton-conductivity dependency on humidity, and high proton conductivity under low humidity. In addition, the polymer of the present invention is excellent in dimensional stability related to water absorption, and therefore can be suitably used particularly for fuel cell applications.

Claims (14)

A structural unit having a segment represented by the following general formula (2) as a segment having an ion exchange group and further comprising a group represented by the following general formula (1c) as a segment having substantially no ion exchange group A polymer having a segment consisting of:

(In the formula, Ar ¹ represents a divalent aromatic group having an ion exchange group, and may have a substituent other than the ion exchange group. X represents a divalent electron withdrawing group. F represents Represents an integer of 1 or more, and two f's may be the same or different from each other, a plurality of Ar ¹ may be the same or different from each other, and m represents the number of repeating units.)

(In the formula, Ar ⁰ represents a divalent aromatic group which may have a substituent.)   The polymer according to claim 1, wherein m is an integer of 5 or more.   The X is an electron-withdrawing group selected from the group consisting of a carbonyl group, a sulfonyl group, and a 1,1,1,3,3,3-hexafluoro-2,2-propylidene group. polymer. The polymer according to any one of claims 1 to 3, wherein the ion exchange group in Ar ¹ is directly bonded to an aromatic ring constituting the main chain.   The polymer according to any one of claims 1 to 4, wherein the ion exchange group is an acid group selected from a sulfonic acid group, a sulfonimide group, a phosphonic acid group, and a carboxyl group. The polymer according to any one of claims 1 to 5, wherein Ar ¹ is an aromatic group represented by the following general formula (4).

(In the formula, R ¹ represents a fluorine atom, an optionally substituted alkyl group having 1 to 20 carbon atoms, an optionally substituted alkoxy group having 1 to 20 carbon atoms, or a substituent. An optionally substituted aryl group having 6 to 20 carbon atoms, an optionally substituted aryloxy group having 6 to 20 carbon atoms, or an optionally substituted acyl having 2 to 20 carbon atoms And p is 0 or 1.) The polymer in any one of Claims 1-6 whose segment which does not have an ion exchange group substantially is a segment represented by following General formula (3).

(In the formula, b, c and d each independently represent 0 or 1, and n represents an integer of 5 or more. Ar ³ , Ar ⁴ , Ar ⁵ and Ar ⁶ independently represent a divalent aromatic group. Wherein these divalent aromatic groups are optionally substituted alkyl groups having 1 to 20 carbon atoms, optionally substituted alkoxy groups having 1 to 20 carbon atoms, A C6-C20 aryl group which may have a substituent, a C6-C20 aryloxy group which may have a substituent, or a C2-C2 which may have a substituent 20 may be substituted with an acyl group. Y and Y ′ each independently represent a direct bond or a divalent group, and Z and Z ′ each independently represent an oxygen atom or a sulfur atom.)   The polymer in any one of Claims 1-7 whose ion exchange capacity is 0.5 meq / g-4.0 meq / g.   The polymer electrolyte which uses the polymer in any one of Claims 1-8 as an active ingredient.   A polymer electrolyte membrane comprising the polymer electrolyte according to claim 9.   A polymer electrolyte composite membrane comprising the polymer electrolyte according to claim 9 and a porous substrate.   A catalyst composition comprising the polymer electrolyte according to claim 9 and a catalyst component.   A polymer electrolyte fuel cell comprising the polymer electrolyte membrane according to claim 10 or the polymer electrolyte composite membrane according to claim 11 as an ion conductive membrane. A polymer electrolyte fuel cell comprising a catalyst layer obtained using the catalyst composition according to claim 12.