JP2009104926A - Membrane electrode assembly - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a membrane electrode assembly (MEA) which has excellent jointing performance between a polymer electrolyte membrane and an electrode and good output characteristics by using as the MEA a polymer electrolyte membrane to reduce methanol crossover, while maintaining a high proton conductivity. <P>SOLUTION: The membrane electrode assembly uses a polymer electrolyte membrane having a proton conductivity of 0.1 S/cm or more and a swelling rate to water of 15% or less. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a membrane electrode assembly (MEA) using a polymer electrolyte membrane containing a block copolymer.

  A fuel cell is expected to be a next-generation power generation device that has high power generation efficiency and is excellent in environmental friendliness, and that can contribute to the solution of environmental problems and energy problems, which are currently major issues. Among these fuel cells, solid polymer fuel cells are smaller and have higher output than any other system, and they are the next generation as small-scale on-site, mobile (on-vehicle) and portable fuel cells. It is said to be the main force. At present, solid polymer fuel cells are not yet in practical use, but as polymer electrolyte membranes for fuel cells used in trial production or testing, perfluoroalkylene groups are the main skeleton, and some “Nafion (R)”, “Flemion (R)”, and the like are known as fluorine-based polymer electrolyte membranes having an ion exchange group such as a sulfonic acid group or a carboxylic acid group at the end of a perfluorovinyl ether side chain.

However, in the currently used fuel cell polymer electrolyte membrane “Nafion (R)” and the like, when the operation is performed at a temperature exceeding 100 ° C., the moisture content of the polymer electrolyte membrane drops rapidly. The softening of the molecular electrolyte membrane is also remarkable. Particularly in the direct methanol fuel cell, which is expected to be in the future, when a conventional fluorine-based proton conductive polymer material such as “Nafion (R)” is used as the electrolyte, the anode The methanol that has passed through the electrolyte diffuses in the swollen electrolyte and reaches the cathode, where it causes a short circuit phenomenon (crossover) in which it directly reacts with the oxidizing agent (O ₂ ) above the cathode catalyst, remarkably improving battery performance. There is a problem that sufficient performance cannot be exhibited because of the reduction. In order to reduce the methanol crossover, it is effective to increase the ion exchange equivalent weight (EW) of the polymer electrolyte membrane. However, there is usually a trade-off between proton conductivity and methanol crossover. When EW is increased, the proton conductivity of the polymer electrolyte membrane decreases. In addition, the polymer electrolyte membrane with increased EW has a low proton conductivity, and thus has a large membrane resistance. When applied to a fuel cell, when the current density is increased, the output voltage is greatly decreased. is there. The decrease in the output voltage due to the increase in current density becomes more noticeable as the membrane resistance of the electrolyte membrane increases. In general, when the thickness of the electrolyte membrane is reduced, the membrane resistance tends to decrease. However, when the electrolyte membrane is thinned, the methanol shielding property is lowered, causing the above-described crossover, and the battery performance is remarkably lowered.

  In addition, when a polymer electrolyte membrane having a large swelling rate is applied to a fuel cell, when the spray coating method is used, the electrolyte membrane repeatedly swells and shrinks due to the solvent contained in the catalyst slurry at the time of electrode preparation. There is a tendency to peel easily from the polymer electrolyte membrane. In addition, when preparing MEA using a GDE in which a diffusion layer is coated with a catalyst layer, and a method in which a catalyst layer is previously formed on release paper and an electrode is transferred onto a polymer electrolyte membrane (transfer method), etc. At the time of hot pressing for bonding the membrane and the electrode, it is considered that the electrode is poorly bonded because the shrinkage occurs due to evaporation of water contained in the polymer electrolyte membrane, and electrode peeling is likely to occur.

  In order to solve such problems, a polymer electrolyte membrane in which a sulfonic acid group for imparting proton conductivity is introduced into a heat-resistant aromatic polymer as an alternative material to a conventional fluorine-based membrane having a large swelling rate From the viewpoint of swelling rate, heat resistance, and chemical stability of polymer electrolyte membranes, sulfonated aromatic polyether ketones, sulfonated aromatic polyether sulfones, sulfonated polyphenylene Kinds etc. are examined (for example, patent documents 1-3).

  Moreover, it is effective to suppress swelling of the electrolyte membrane as a method for reducing methanol crossover and a method for satisfactorily improving the bondability between the membrane and the electrode. As a technique for reducing the swelling rate, for example, crosslinking by a sulfonate bond obtained by desulfurization condensation of sulfonic acid groups in a polyether ether ketone film (Patent Document 4), an alkyl group directly connected to a carbonyl group and an aromatic ring (Patent Document 5) has been studied, but there are problems such as a decrease in proton conductivity due to a reduction in sulfonic acid groups and difficulty in controlling the crosslinking density. Also, studies have been made on pore filling type electrolyte membranes in which a porous substrate is filled with an electrolyte polymer (Patent Documents 6 and 7). It is described that this pore filling type electrolyte membrane has a high methanol shielding property that exceeds Nafion even in a high temperature range because the porous substrate suppresses the swelling of the filled electrolyte. However, it has been difficult to fill a sufficient amount of electrolyte polymer in the pores of the porous substrate. In order to increase the filling rate of the electrolyte polymer, it is necessary to repeat the filling operation, which may increase the manufacturing cost, and even if the filling is performed completely, the introduction of a substrate that does not have proton conductivity Therefore, when applied to a fuel cell, when the current density is increased, the output voltage is greatly reduced. Therefore, in order to obtain the bondability and output between the good polymer electrolyte membrane and the electrode, it is necessary to use a polymer electrolyte membrane that has both high proton conductivity and low swelling ratio as the MEA.

  In addition, studies have been made to further improve proton conductivity by making these sulfonated aromatic polymers into a block copolymer that has been blocked into a hydrophilic segment into which a sulfonic acid group has been introduced and a hydrophobic segment into which the sulfonate group has not been introduced. It has been broken. As a method for synthesizing a block copolymer composed of a hydrophilic part segment and a hydrophobic part segment, first, a polymerization reaction is performed on either the hydrophilic part segment or the hydrophobic part segment to increase the molecular weight, and then the other segment. A sequential addition method is known in which the monomers are added and polymerized sequentially. The sequential addition method is easy to operate because a block copolymer can be synthesized by One-Pot, but is problematic in that randomization is likely to occur and block chain length is difficult to control. On the other hand, it is also possible to synthesize a block copolymer by a method in which a hydrophilic part segment and a hydrophobic part segment are individually synthesized and then both are reacted. Compared to the sequential addition method, there are problems such as the synthesis operation is complicated and the polarities of the hydrophilic part segment and the hydrophobic part segment are greatly different, so that the compatibility is poor and the blocking reaction is difficult to proceed. . As a method for solving the compatibility problem, Patent Document 8 discloses a method for obtaining a block copolymer by using a solvent obtained by mixing two types of good solvents for hydrophilic segments and good solvents for hydrophobic segments. .

JP-A-6-93114 Japanese Patent No. 3861367 JP 2001-329053 A JP 2000-501223 Gazette JP 2003-217342 A JP 2002-83612 A International Publication No. 00/54351 Pamphlet JP 2007-106986 A

  In view of the above circumstances, the present invention uses the polymer electrolyte membrane that reduces methanol crossover while maintaining high proton conductivity in the MEA, so that the bondability between the polymer electrolyte membrane and the electrode and the output characteristics are improved. It aims at providing a favorable membrane electrode assembly (MEA).

As a result of intensive studies, the present inventors have found that the above problem can be solved by adjusting the swelling ratio of a polymer electrolyte membrane containing a specific block copolymer and using this polymer electrolyte membrane for MEA. Specifically, it has the following characteristics.
1. A membrane / electrode assembly comprising a polymer electrolyte membrane having a proton conductivity of 0.1 S / cm or more and a swelling ratio with respect to water of 15% or less.
2. 2. The membrane / electrode assembly according to item 1, wherein an electrode is formed by spray coating on a polymer electrolyte membrane having a proton conductivity of 0.1 S / cm or more and a swelling ratio with respect to water of 15% or less.
3. Forming an electrode on a polymer electrolyte membrane having a proton conductivity of 0.1 S / cm or more and a swelling ratio with respect to water of 15% or less by bonding a gas diffusion electrode (hereinafter referred to as GDE). Item 2. The membrane electrode assembly according to Item 1, wherein
4). Item 2. The membrane electrode assembly according to Item 1, wherein an electrode is formed by a transfer method on a polymer electrolyte membrane having a proton conductivity of 0.1 S / cm or more and a swelling ratio with respect to water of 15% or less.
5). Item 2. The membrane electrode assembly according to Item 1, wherein an electrode is directly formed on the polymer electrolyte membrane by spray-coating a catalyst slurry containing a noble metal catalyst.
6). Item 6. The membrane electrode assembly according to Item 5, wherein the catalyst slurry is a composition capable of dissolving the noble metal catalyst, the electrolyte binder, and the electrolyte binder and dispersing the noble metal catalyst.
7). A polymer electrolyte membrane having a proton conductivity of 0.1 S / cm or more and a swelling ratio with respect to water of 15% or less is (a) a first aromatic having a perfluorobiphenyl group at the terminal and having a proton acid group Copolymer with a polymer compound and (b) a second aromatic polymer compound having a reactive group capable of reacting with the perfluorobiphenyl group of (a) and having no proton acid group Item 7. The membrane electrode assembly according to any one of Items 1 to 6, which is a polymer electrolyte membrane containing a combination.
8). (A) The first aromatic polymer compound has a hydrophobic aromatic halogen group, and the hydrophobic aromatic halogen group is a structural unit of the following formula (1): Membrane electrode assembly.

［式中ＡはＳ（Ｏ）−、−Ｓ（Ｏ）_２−、−Ｃ（Ｏ）−、または−Ｐ（Ｏ）（Ｃ_６Ｈ_５）−を示す。Ｂ、Ｃ，Ｄ，Ｅは水素または炭素数１〜２０のアルキル基、炭素数１〜２０のフルオロアルキル基、シアノ基、及びフッ素を示す。Ｆはフッ素を示す。］

[Wherein A is _{S (O) -, - S} (O) 2 -, - C (O) -, or _{-P (O) (C 6 H} 5) - shows the. B, C, D, and E represent hydrogen or an alkyl group having 1 to 20 carbon atoms, a fluoroalkyl group having 1 to 20 carbon atoms, a cyano group, and fluorine. F represents fluorine. ]

9. (A) Structure in which the first aromatic polymer compound has a hydrophobic aromatic halogen group, and the hydrophobic aromatic halogen group has a heterocycle of the following formula (2) and / or formula (3) Item 8. The membrane electrode assembly according to Item 7, which is a unit.

［式中Ａは直接結合、−Ｏ−、−Ｓ−、−Ｓ（Ｏ）−、−Ｓ（Ｏ）_２−、−Ｃ（Ｏ）−、−Ｐ（Ｏ）（Ｃ_６Ｈ_５）−、−Ｃ（ＣＨ_３）_２−、−Ｃ（ＣＦ_３）_２−、または−Ｃ_６Ｈ_４ＣＣ_６Ｈ_４−を示す。Ｒは水素または炭素数１〜２０のアルキル基、炭素数１〜２０のアルコキシ基、炭素数６〜２０のアリール基、炭素数６〜２０のアリールオキシ基又は炭素数２〜２０のアシル基、及びフッ素であり、ｆ及びｊは１〜５の置換基数を示す。Ｆはフッ素を示す。］

[In the formula, A represents a direct bond, —O—, —S—, —S (O) —, —S (O) ₂ —, —C (O) —, —P (O) (C ₆ H ₅ ) —. _{, -C (CH 3) 2 -} , - C (CF 3) 2 -, or _{-C 6 H 4 CC 6 H 4} - shows a. R is hydrogen or 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 an acyl group having 2 to 20 carbon atoms, And fluorine, and f and j represent 1 to 5 substituents. F represents fluorine. ]

［式中Ｚは直接結合、−ＮＨ−、炭素数１〜１０のアルキルアミノ基、−ＮＣ_６Ｈ_４−、−Ｏ−、または−Ｓ−を示す。Ｒは水素または炭素数１〜２０のアルキル基、炭素数１〜２０のアルコキシ基、炭素数６〜２０のアリール基、炭素数６〜２０のアリールオキシ基又は炭素数２〜２０のアシル基、及びフッ素であり、ｆは１〜５の置換基数を表わす。］

[Wherein Z represents a direct bond, —NH—, an alkylamino group having 1 to 10 carbon atoms, —NC ₆ H ₄ —, —O—, or —S—. R is hydrogen or 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 an acyl group having 2 to 20 carbon atoms, And fluorine, and f represents the number of substituents of 1 to 5. ]

10. Item 10. The membrane electrode assembly according to any one of Items 7 to 9, wherein the reactive group capable of reacting with the perfluorobiphenyl group of (b) is a phenolic hydroxyl group.
11. (A) The weight average molecular weight of the first aromatic polymer compound is 2,000 to 150,000, and (b) the weight average molecular weight of the second aromatic polymer compound is 2,000 to 150,000. Item 11. The membrane electrode assembly according to any one of Items 7 to 10.
12 The value of the weight ratio [(a) / (b)] between the first aromatic polymer compound (a) and the second aromatic polymer compound (b) is 0.1 or more and 10.0 or less. Item 12. The membrane electrode assembly according to any one of Items 7 to 11, wherein the membrane electrode assembly is provided.
13. The first aromatic polymer compound of (a) has an aromatic ring into which the (α) protonic acid group of the following formula (4) and / or the following formula (5) and / or the following formula (6) is introduced. Item 13. The membrane electrode assembly according to any one of Items 7 to 12, which comprises a structural unit having.

［式において、Ａは直接結合、−Ｏ−、−Ｓ−、−Ｓ（Ｏ）−、−Ｓ（Ｏ）_２−、−Ｃ（Ｏ）−、−Ｐ（Ｏ）（Ｃ_６Ｈ_５）−、−Ｃ（ＣＨ_３）_２−、−Ｃ（ＣＦ_３）_２−、−Ｃ_６Ｈ_４ＣＣ_６Ｈ_４−、または、

[In the formula, A represents a direct bond, —O—, —S—, —S (O) —, —S (O) ₂ —, —C (O) —, —P (O) (C ₆ H ₅ ). _{-, - C (CH 3)} 2 -, - C (CF 3) 2 -, - C 6 H 4 CC 6 H 4 -, or,

［式中Ｘはスルホン酸基、リン酸基、炭素数１〜６のアルキルスルホン酸基、炭素数１〜２０のアルキルコキシスルホン酸基、炭素数１〜６のアルキルリン酸基、炭素数１〜２０のアルキルコキシリン酸基から成るプロトン酸基を示す。ｍは１〜４の置換基数を表わし、ｆは４−ｍの置換基数を表わす。ｎは１〜４の置換基数を表わし、ｊは４−ｎの置換基数を表わす。］を示す。Ｒは水素または炭素数１〜２０のアルキル基、炭素数１〜２０のアルコキシ基、炭素数６〜２０のアリール基、炭素数６〜２０のアリールオキシ基又は炭素数２〜２０のアシル基、及びフッ素であり、Ｘは水素、スルホン酸基、リン酸基、炭素数１〜６のアルキルスルホン酸基、炭素数１〜２０のアルキルコキシスルホン酸基、炭素数１〜６のアルキルリン酸基、炭素数１〜２０のアルキルコキシリン酸基から成るプロトン酸基を示す。ｍは１〜４の置換基数を表わし、ｆは４−ｍの置換基数を表わす。ｎは１〜４の置換基数を表わし、ｊは４−ｎの置換基数を表わす。］

[Wherein X is a sulfonic acid group, a phosphoric acid group, an alkylsulfonic acid group having 1 to 6 carbon atoms, an alkyloxysulfonic acid group having 1 to 20 carbon atoms, an alkylphosphoric acid group having 1 to 6 carbon atoms, or a carbon number. A protonic acid group consisting of 1 to 20 alkylcoxyphosphate groups is shown. m represents the number of substituents of 1 to 4, and f represents the number of substituents of 4-m. n represents the number of substituents of 1 to 4, and j represents the number of substituents of 4-n. ] Is shown. R is hydrogen or 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 an acyl group having 2 to 20 carbon atoms, X is hydrogen, a sulfonic acid group, a phosphoric acid group, an alkyl sulfonic acid group having 1 to 6 carbon atoms, an alkyl oxysulfonic acid group having 1 to 20 carbon atoms, and an alkyl phosphoric acid having 1 to 6 carbon atoms. A protonic acid group composed of an alkylcoxyphosphoric acid group having 1 to 20 carbon atoms. m represents the number of substituents of 1 to 4, and f represents the number of substituents of 4-m. n represents the number of substituents of 1 to 4, and j represents the number of substituents of 4-n. ]

［式中Ｒは水素または炭素数１〜２０のアルキル基、炭素数１〜２０のアルコキシ基、炭素数６〜２０のアリール基、炭素数６〜２０のアリールオキシ基又は炭素数２〜２０のアシル基、及びフッ素であり、Ｘはスルホン酸基、リン酸基、炭素数１〜６のアルキルスルホン酸基、炭素数１〜２０のアルキルコキシスルホン酸基、炭素数１〜６のアルキルリン酸基、炭素数１〜２０のアルキルコキシリン酸基から成るプロトン酸基を示す。ｍは１から４の置換基数を表わし、ｆは４−ｍの置換基数を表わす。ｎは１から４の置換基数を表わし、ｊは４−ｎの置換基数を表わす。］

[Wherein R is hydrogen or 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 an alkyl group having 2 to 20 carbon atoms. X is sulfonic acid group, phosphoric acid group, alkyl sulfonic acid group having 1 to 6 carbon atoms, alkyl oxysulfonic acid group having 1 to 20 carbon atoms, alkyl phosphorus having 1 to 6 carbon atoms. A protonic acid group composed of an acid group and an alkylcoxyphosphate group having 1 to 20 carbon atoms is shown. m represents the number of substituents of 1 to 4, and f represents the number of substituents of 4-m. n represents the number of substituents of 1 to 4, and j represents the number of substituents of 4-n. ]

14 The first aromatic polymer compound of (a) includes a structural unit having a heterocycle having a (β) protonic acid group introduced by the following formula (7) and / or formula (8): The membrane electrode assembly according to any one of claims 7 to 13.

［式中Ａは直接結合、−Ｏ−、−Ｓ−、−Ｓ（Ｏ）−、−Ｓ（Ｏ）_２−、−Ｃ（Ｏ）−、−Ｐ（Ｏ）（Ｃ_６Ｈ_５）−、−Ｃ（ＣＨ_３）_２−、−Ｃ（ＣＦ_３）_２−、−Ｃ_６Ｈ_４ＣＣ_６Ｈ_４−または炭素数１〜１０のアルキリデン基を示す。Ｒは水素または炭素数１〜２０のアルキル基、炭素数１〜２０のアルコキシ基、炭素数６〜２０のアリール基、炭素数６〜２０のアリールオキシ基又は炭素数２〜２０のアシル基、及びフッ素であり、Ｘはスルホン酸基、リン酸基、炭素数１〜６のアルキルスルホン酸基、炭素数１〜２０のアルキルコキシスルホン酸基、炭素数１〜６のアルキルリン酸基、炭素数１〜２０のアルキルコキシリン酸基から成るプロトン酸基を示す。ｍは１〜５の置換基数を表わし、ｆは５−ｍの置換基数を表わす。ｎは１〜５の置換基数を表わし、ｊは５−ｎの置換基数を表わす。］

[In the formula, A represents a direct bond, —O—, —S—, —S (O) —, —S (O) ₂ —, —C (O) —, —P (O) (C ₆ H ₅ ) —. _{, -C (CH 3) 2 -} , - C (CF 3) 2 -, - indicating the or alkylidene group having 1 to 10 carbon atoms _{- C 6 H 4 CC 6 H} 4. R is hydrogen or 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 an acyl group having 2 to 20 carbon atoms, X is a sulfonic acid group, a phosphoric acid group, an alkyl sulfonic acid group having 1 to 6 carbon atoms, an alkyloxy sulfonic acid group having 1 to 20 carbon atoms, an alkyl phosphoric acid group having 1 to 6 carbon atoms, The protonic acid group which consists of a C1-C20 alkylcoxyphosphoric acid group is shown. m represents the number of substituents of 1 to 5, and f represents the number of substituents of 5-m. n represents the number of substituents of 1 to 5, and j represents the number of substituents of 5-n. ]

［式中Ｚは直接結合、−ＮＨ−、炭素数１〜１０のアルキルアミノ基、−ＮＣ_６Ｈ_４−、−Ｏ−、または−Ｓ−を示す。Ｒは水素または炭素数１〜２０のアルキル基、炭素数１〜２０のアルコキシ基、炭素数６〜２０のアリール基、炭素数６〜２０のアリールオキシ基又は炭素数２〜２０のアシル基、及びフッ素であり、Ｘはスルホン酸基、リン酸基、炭素数１〜６のアルキルスルホン酸基、炭素数１〜２０のアルキルコキシスルホン酸基、炭素数１〜６のアルキルリン酸基、炭素数１〜２０のアルキルコキシリン酸基から成るプロトン酸基を示す。ｍは１〜５の置換基数を表わし、ｆは５−ｍの置換基数を表わす。］

[Wherein Z represents a direct bond, —NH—, an alkylamino group having 1 to 10 carbon atoms, —NC ₆ H ₄ —, —O—, or —S—. R is hydrogen or 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 an acyl group having 2 to 20 carbon atoms, X is a sulfonic acid group, a phosphoric acid group, an alkyl sulfonic acid group having 1 to 6 carbon atoms, an alkyloxy sulfonic acid group having 1 to 20 carbon atoms, an alkyl phosphoric acid group having 1 to 6 carbon atoms, The protonic acid group which consists of a C1-C20 alkylcoxyphosphoric acid group is shown. m represents the number of substituents of 1 to 5, and f represents the number of substituents of 5-m. ]

15. The second aromatic polymer compound of (b) includes a structural unit having a (γ) aromatic ring of the following formula (9) and / or the following formula (10) and / or the following formula (11). The membrane electrode assembly according to any one of claims 7 to 14, wherein

［式中Ａは直接結合、−Ｏ−、−Ｓ−、−Ｓ（Ｏ）−、−Ｓ（Ｏ）_２−、−Ｃ（Ｏ）−、−Ｐ（Ｏ）（Ｃ_６Ｈ_５）−、−Ｃ（ＣＨ_３）_２−、−Ｃ（ＣＦ_３）_２−、−Ｃ_６Ｈ_４ＣＣ_６Ｈ_４−、または

[In the formula, A represents a direct bond, —O—, —S—, —S (O) —, —S (O) ₂ —, —C (O) —, —P (O) (C ₆ H ₅ ) —. _{, -C (CH 3) 2 -} , - C (CF 3) 2 -, - C 6 H 4 CC 6 H 4 -, or

を示す。Ｂ、Ｃ，Ｄ，Ｅは水素または炭素数１〜２０のアルキル基、炭素数１〜２０のアルコキシ基、炭素数６〜２０のアリール基、炭素数６〜２０のアリールオキシ基又は炭素数２〜２０のアシル基、シアノ基、及びフッ素である。］

Indicates. B, C, D, and E are hydrogen or 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. ˜20 acyl groups, cyano groups, and fluorine. ]

［式中Ｆ、Ｇは水素または炭素数１〜２０のアルキル基、炭素数１〜２０のアルコキシ基、炭素数６〜２０のアリール基、炭素数６〜２０のアリールオキシ基又は炭素数２〜２０のアシル基、シアノ基、及びフッ素である。］

[Wherein F and G are hydrogen or 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 to 2 carbon atoms. 20 acyl groups, cyano groups, and fluorine. ]

16. Item 7 to Item 8, wherein the second aromatic polymer compound of (b) contains a structural unit having the (δ) heterocyclic ring of the following formula (12) and / or formula (13). The membrane electrode assembly according to any one of 15.

［式中Ａは直接結合、−Ｏ−、−Ｓ−、−Ｓ（Ｏ）−、−Ｓ（Ｏ）_２−、−Ｃ（Ｏ）−、−Ｐ（Ｏ）（Ｃ_６Ｈ_５）−、−Ｃ（ＣＨ_３）_２−、−Ｃ（ＣＦ_３）_２−、−Ｃ_６Ｈ_４ＣＣ_６Ｈ_４−または炭素数１〜１０のアルキリデン基を示す。Ｒは水素または炭素数１〜２０のアルキル基、炭素数１〜２０のアルコキシ基、炭素数６〜２０のアリール基、炭素数６〜２０のアリールオキシ基又は炭素数２〜２０のアシル基、及びフッ素であり、ｆ及びｊは１〜５の置換基数を表わす。］

[In the formula, A represents a direct bond, —O—, —S—, —S (O) —, —S (O) ₂ —, —C (O) —, —P (O) (C ₆ H ₅ ) —. _{, -C (CH 3) 2 -} , - C (CF 3) 2 -, - indicating the or alkylidene group having 1 to 10 carbon atoms _{- C 6 H 4 CC 6 H} 4. R is hydrogen or 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 an acyl group having 2 to 20 carbon atoms, And fluorine, and f and j represent 1 to 5 substituents. ]

［式中Ｚは直接結合、−ＮＨ−、炭素数１〜１０のアルキルアミノ基、−ＮＣ_６Ｈ_４−、−Ｏ−、または−Ｓ−を示す。Ｒは水素または炭素数１〜２０のアルキル基、炭素数１〜２０のアルコキシ基、炭素数６〜２０のアリール基、炭素数６〜２０のアリールオキシ基又は炭素数２〜２０のアシル基、及びフッ素であり、ｆは１〜５の置換基数を表わす。］

[Wherein Z represents a direct bond, —NH—, an alkylamino group having 1 to 10 carbon atoms, —NC ₆ H ₄ —, —O—, or —S—. R is hydrogen or 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 an acyl group having 2 to 20 carbon atoms, And fluorine, and f represents the number of substituents of 1 to 5. ]

17. (Α) In the structural unit having an aromatic ring having a proton acid group introduced therein, the proton acid group is a sulfonic acid group or / and a phosphoric acid group. body.
18. Item 8. The membrane electrode assembly according to Item 7, wherein the first aromatic polymer compound of (a) is the following formula (14).

［式中Ａは直接結合、−Ｏ−、−Ｓ−、−Ｓ（Ｏ）−、−Ｓ（Ｏ）_２−、−Ｃ（Ｏ）−、−Ｐ（Ｏ）（Ｃ_６Ｈ_５）−、−Ｃ（ＣＨ_３）_２−、−Ｃ（ＣＦ_３）_２−、または−Ｃ_６Ｈ_４ＣＣ_６Ｈ_４−を示す。ｎは３以上の整数よりなる。］

[In the formula, A represents a direct bond, —O—, —S—, —S (O) —, —S (O) ₂ —, —C (O) —, —P (O) (C ₆ H ₅ ) —. _{, -C (CH 3) 2 -} , - C (CF 3) 2 -, or _{-C 6 H 4 CC 6 H 4} - shows a. n consists of an integer of 3 or more. ]

  The present invention provides an MEA with a polymer electrolyte membrane that reduces methanol crossover while maintaining high proton conductivity by suppressing the swelling rate with respect to water to 15% or less with a proton conductivity of 0.1 S / cm or more. By using it, it is possible to obtain a membrane / electrode assembly (MEA) having good bondability and output characteristics between the polymer electrolyte membrane and the electrode.

Hereinafter, the present invention will be described in detail.
The membrane / electrode assembly (MEA) of the present invention can be obtained by using a polymer electrolyte membrane containing a block copolymer having a proton conductivity of 0.1 S / cm or more and a swelling ratio with respect to water of 15% or less. It is characterized in that the bondability and output characteristics between the molecular electrolyte membrane and the electrode can be obtained. Usually, in a polymer electrolyte membrane synthesized with an electrolyte polymer by random polymerization, proton conductive groups are uniformly distributed in the polymer electrolyte membrane. For this reason, a clear proton conduction path cannot be obtained, and in order to maintain high proton conductivity, the composition of the proton conductive group must be increased. However, since the composition of the proton conductive group is increased throughout the polymer electrolyte membrane, the water content of the polymer electrolyte membrane increases, and the swelling suppression effect by the hydrophobic segment cannot be obtained.

  Therefore, it is considered that by forming a hydrophilic segment and ensuring a clear proton conduction path, high proton conductivity can be obtained and swelling suppression of the hydrophobic segment can be effectively obtained. Usually, crossover occurs when methanol permeates through the ptron conduction path in the polymer electrolyte membrane, and the crossover of methanol increases due to further expansion of the proton conduction path due to swelling of the polymer electrolyte membrane. Therefore, the size of the proton conduction path is defined within the range that does not impair the proton conductivity, and methanol is maintained while maintaining high proton conductivity by suppressing swelling of the polymer electrolyte membrane by the hydrophobic segment. It is considered that crossover can be reduced and good polymer electrolyte membrane-electrode bondability and output characteristics can be obtained.

  The proton conductivity of the polymer electrolyte membrane containing the block copolymer is preferably 0.1 S / cm or more. When the proton conductivity is 0.1 S / cm or more, a good output tends to be obtained in a fuel cell using the polymer electrolyte membrane. When the proton conductivity is less than 0.1 S / cm, the fuel cell There is a tendency for the output to decrease.

An evaluation cell shown in FIG. 1 was prepared for measurement of proton conductivity. A platinum electrode was used as the electrode, and the electrode interval was 1 cm. The cell was placed in a beaker containing pure water so that the electrolyte portion was immersed in pure water, and the resistance of the electrolyte membrane was measured by an AC impedance method. The evaluation method is that the cell is connected to a 1260 FREQUENCY RESPONSE ANALYSER made by Solartron with four terminals, and the real and imaginary parts of the total impedance detected when the AC frequency is arbitrarily changed from 10 kHz to 0.1 Hz are complex. Curve fitting is performed for several points in the Cole-Cole plot plotted on the surface, and the resistance of the electrolyte membrane can be obtained from the value of the intercept.
This was substituted into Equation 2 to calculate proton conductivity.
σ = L / (R × S) (Formula 2)
σ: proton conductivity (S / cm), L: distance between electrodes (cm), R: resistance (Ω), S: membrane cross-sectional area (cm ² )

  The swelling ratio of the polymer electrolyte membrane is preferably 15% or less, more preferably 12% or less, and most preferably 10% or less. When the swelling ratio is 10% or less, the polymer electrolyte membrane and electrode have good bondability and output characteristics, and when it exceeds 15%, the polymer electrolyte membrane and electrode have poor bondability. Therefore, the output characteristics tend to deteriorate.

The swelling ratio of the polymer electrolyte membrane was measured by immersing a polymer electrolyte membrane having a thickness of 50 to 150 μm cut into an arbitrary size in water at 80 ° C. for 8 hours, and holding at room temperature for 16 hours. The change λ can be obtained from the following equation. The area after immersion can be determined from the product obtained by wiping the surface of the electrolyte membrane lightly with filter paper (5A), measuring the lengths of the vertical and horizontal sides.
λ = {(S−So) −So} × 100
(S is the area after swelling of the polymer electrolyte membrane-So is the area before swelling of the polymer electrolyte membrane)

<Membrane electrode assembly; MEA>
The MEA of the present invention is manufactured by providing the electrode on the electrolyte membrane. Preferably, the catalyst layer side of the electrode is joined to the polymer electrolyte membrane side. Examples of the MEA manufacturing method include the following three methods.
(1) Spray coating method: A method in which a catalyst layer is directly formed on an electrolyte membrane to form a catalyst layer, and a gas diffusion layer is formed on the formed catalyst layer. For example, a catalyst material containing a perfluorocarbon polymer having an ion exchange group, a platinum group catalyst, fine carbon powder (carbon black) and other additives is applied onto an electrolyte membrane by a method described in JP-T-2000-516014, sprayed, There is a method in which a catalyst layer is formed by printing or the like, and a gas diffusion layer is thermocompression-bonded on the catalyst layer by hot pressing or the like.
(2) GDE bonding: A method in which an electrode is prepared in advance by immersing the gas diffusion layer in a catalyst material solution, and the obtained electrode is provided on the electrolyte membrane. For example, the gas diffusion layer is immersed in a solution (paste) of a soluble platinum group salt to adsorb (ion exchange) the soluble platinum group salt on and in the gas diffusion layer. Next, there is a method in which a metal serving as a catalyst is deposited on a gas diffusion layer by dipping in a reducing agent solution such as hydrazine or Na ₂ BO ₄ .
(3) Transfer method: A method in which a catalyst layer is prepared on a substrate in advance to produce a catalyst layer, the obtained catalyst layer is transferred onto an electrolyte membrane, and a gas diffusion layer is formed on the formed catalyst layer. For example, polytetrafluoroethylene in advance and platinum black synthesized by the Thomas method or the like are uniformly mixed, applied onto a Teflon (registered trademark) sheet substrate, pressure-molded, transferred onto the electrolyte membrane, Further, there is a method in which a gas diffusion layer is disposed and the obtained laminate is pressure-bonded.

  A more preferable method for producing the MEA of the present invention includes a method in which an electrode material containing a catalyst substance and a gas diffusion layer material is directly applied on the electrolyte membrane. Specifically, catalyst-supported carbon particles or catalyst black supporting a catalyst material such as platinum-ruthenium (Pt-Ru) platinum (Pt) is used as the catalyst material, and the catalyst material is mixed with a solvent such as water or a solid. A catalyst slurry is made by mixing with a binder such as a polymer electrolyte and optionally a water repellent such as polytetrafluoroethylene (PTFE) particles used in the manufacture of the gas diffusion layer. The catalyst slurry is directly applied on the electrolyte membrane of the present invention by coating or spraying to form a film, followed by heating and drying to form a catalyst layer (or a part of the gas diffusion layer when a water repellent is included) on the polymer electrolyte. Forming a water-repellent layer. On this catalyst layer, a gas diffusion layer such as carbon paper optionally treated with water repellency is hot-pressed to produce an electrode.

  The thickness of the catalyst layer at this time is suitably, for example, 0.1 to 1000 μm, preferably 1 to 500 μm, more preferably 2 to 200 μm.

  The catalyst slurry preferably has a viscosity adjusted in the range of 0.1 to 1000 Pa · S. This viscosity can either (i) select each particle size, (ii) adjust the composition of the catalyst particles and binder, (iii) adjust the water content, or (iv) The viscosity can be adjusted preferably by adding viscosity modifiers such as carboxymethyl cellulose, methyl cellulose, hydroxyethyl cellulose and cellulose, and polyethylene glycol, polyvinyl alcohol, polyvinyl pyrrolidone, sodium polyacrylate and polymethyl vinyl ether.

<Electrode>
The electrode of the present invention has a gas diffusion layer and a catalyst layer provided on and / or in the gas diffusion layer.

<Gas diffusion layer>
As the gas diffusion layer, for example, a known substrate having air permeability such as a carbon fiber woven fabric or carbon paper can be used. Preferably, those substrates and the like that have been subjected to water repellent treatment are used. The water-repellent treatment is performed, for example, by immersing these substrates in an aqueous solution of a water-repellent agent made of a fluororesin such as polytetrafluoroethylene, tetrafluoroethylene-hexafluoropropylene copolymer, drying, and firing. Done.

<Catalyst layer>
As the catalyst material used in the catalyst layer, for example, platinum group metals such as platinum, rhodium, ruthenium, iridium, palladium, osnium, and alloys thereof are suitable. These catalytic materials and salts of the catalytic materials may be used alone or in combination. Among these, metal salts and complexes, particularly ammine complexes represented by [Pt (NH ₃ ) ₄ ] X ₂ or [Pt (NH ₃ ) ₆ ] X ₄ (X is a monovalent anion) are preferable. Moreover, when using a metal compound as a catalyst, the mixture of several compounds may be used and double salt may be sufficient. For example, by using a mixture of a platinum compound and a ruthenium compound, formation of a platinum-ruthenium alloy can be expected by a reduction process.

  The particle size of the catalyst is not particularly limited, but it is preferable that the average particle size is 0.5 to 20 nm from the viewpoint of an appropriate size that increases the catalyst activity. K.K. In a study by Kinoshita et al. (J. Electrochem.-Soc., 137, 845 (1990)), it is reported that the particle size of platinum having a high activity for oxygen reduction is about 3 nm.

A cocatalyst can be further added to the catalyst used in the present invention. The cocatalyst includes finely divided carbon. The finely divided carbon is preferably one in which the coexisting catalyst exhibits high activity. For example, when a platinum group metal compound is used as the catalyst, acetylene black such as Denka Black, Valcan XC-72, Black Pearl 2000, etc. Is appropriate. The amount of the catalyst varies depending on the deposition method and the like, but is deposited on the surface of the gas diffusion layer, for example, in the range of about 0.02 to about 20 mg / cm ² , preferably in the range of about 0.02 to about 20 mg / cm ^2. It is appropriate. Moreover, it is appropriate that it exists in the quantity of 0.01-10 mass% with respect to the total amount of an electrode, for example, Preferably, it is 0.3-5 mass%.

<Binder>
The electrode of the present invention preferably has a binder in and / or on the surface of the electrode. Such a binder promotes the bond between the gas diffusion layer and the catalyst layer and the bond between the electrode and the polymer electrolyte membrane. As the binder, for example, all polymers that can be used in the present invention, and other fluorine-based solid polymer electrolytes such as Nafion (R) and Flemion (R) can be used.

<Characteristics of electrode>
The resulting electrode is porous. The average pore diameter of the electrode is, for example, 0.01 to 50 μm, preferably 0.1 to 40 μm. Furthermore, the porosity of the electrode is, for example, 10 to 99%, preferably 10 to 60%.

<Terminal reactive group>
The hydrophobic aromatic halogen group (a) of the present invention is preferably a structural unit of the following formula (1).

［式中ＡはＳ（Ｏ）−、−Ｓ（Ｏ）_２−、−Ｃ（Ｏ）−、または−Ｐ（Ｏ）（Ｃ_６Ｈ_５）−を示す。Ｂ、Ｃ，Ｄ，Ｅは水素または炭素数１〜２０のアルキル基、炭素数１〜２０のフルオロアルキル基、シアノ基、及びフッ素を示す。Ｆはフッ素を示す。］
式（１）としては例えば、

[Wherein A is _{S (O) -, - S} (O) 2 -, - C (O) -, or _{-P (O) (C 6 H} 5) - shows the. B, C, D, and E represent hydrogen or an alkyl group having 1 to 20 carbon atoms, a fluoroalkyl group having 1 to 20 carbon atoms, a cyano group, and fluorine. F represents fluorine. ]
As formula (1), for example,

等が挙げられる。

Etc.

  In addition, the hydrophobic aromatic halogen group (a) of the present invention is preferably a structural unit having a heterocycle of the following formula (2) and / or formula (3).

［式中Ａは直接結合、−Ｏ−、−Ｓ−、−Ｓ（Ｏ）−、−Ｓ（Ｏ）_２−、−Ｃ（Ｏ）−、−Ｐ（Ｏ）（Ｃ_６Ｈ_５）−、−Ｃ（ＣＨ_３）_２−、−Ｃ（ＣＦ_３）_２−、または−Ｃ_６Ｈ_４ＣＣ_６Ｈ_４−を示す。Ｒは水素または炭素数１〜２０のアルキル基、炭素数１〜２０のアルコキシ基、炭素数６〜２０のアリール基、炭素数６〜２０のアリールオキシ基又は炭素数２〜２０のアシル基、及びフッ素であり、ｆ及びｊは１〜５の置換基数を示す。Ｆはフッ素を示す。］
式（２）としては例えば、

[In the formula, A represents a direct bond, —O—, —S—, —S (O) —, —S (O) ₂ —, —C (O) —, —P (O) (C ₆ H ₅ ) —. _{, -C (CH 3) 2 -} , - C (CF 3) 2 -, or _{-C 6 H 4 CC 6 H 4} - shows a. R is hydrogen or 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 an acyl group having 2 to 20 carbon atoms, And fluorine, and f and j represent 1 to 5 substituents. F represents fluorine. ]
As formula (2), for example,

等が挙げられる。

Etc.

［式中Ｚは直接結合、−ＮＨ−、炭素数１〜１０のアルキルアミノ基、−ＮＣ_６Ｈ_４−、−Ｏ−、または−Ｓ−を示す。Ｒは水素または炭素数１〜２０のアルキル基、炭素数１〜２０のアルコキシ基、炭素数６〜２０のアリール基、炭素数６〜２０のアリールオキシ基又は炭素数２〜２０のアシル基、及びフッ素であり、ｆは１〜５の置換基数を表わす。］
式（３）としては例えば、

[Wherein Z represents a direct bond, —NH—, an alkylamino group having 1 to 10 carbon atoms, —NC ₆ H ₄ —, —O—, or —S—. R is hydrogen or 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 an acyl group having 2 to 20 carbon atoms, And fluorine, and f represents the number of substituents of 1 to 5. ]
As an expression (3), for example,

等が挙げられる。
（ｂ）の末端に（ａ）の疎水性芳香族ハロゲン基と反応し得る反応性基に特に制限は無いが、芳香族アミノ基、芳香族チオール基、フェノール性水酸基等が好ましく、フェノール性水酸基が反応性、及び取扱い易さの観点から特に好ましい。

Etc.
There is no particular limitation on the reactive group capable of reacting with the hydrophobic aromatic halogen group of (a) at the end of (b), but an aromatic amino group, an aromatic thiol group, a phenolic hydroxyl group, etc. are preferred. Is particularly preferable from the viewpoints of reactivity and ease of handling.

<Introduction of terminal reactive groups>
As a method for introducing a terminal reactive group, 1) polymerization is started from a compound in which the reactive group is protected, and further, the polymerization is stopped with the compound in which the reactive group is protected, whereby a polymer in which the reactive group is protected at the terminal is obtained. The reactive group can be introduced into the polymer terminal by synthesizing and further removing the protecting group. 2) In the copolymerization of the bifunctional monomer, a polymer in which the functional group of the monomer component used excessively is introduced at the terminal is also obtained by performing polymerization without intentionally matching the monomer equivalent ratio. be able to.

  Further, using a polymer having a reactive group at the terminal synthesized by the above method as a precursor, the monomer component capable of reacting with the precursor is reacted with 2 equivalents with respect to the terminal reactive group of the precursor. Thus, a terminal reactive polymer having reactivity different from that of the precursor can be obtained. As the method for introducing the hydrophobic aromatic halogen group (a) of the present invention, for example, a precursor of the first aromatic polymer compound (a) having a phenolic hydroxyl group at the terminal is prepared, and the precursor It can be obtained by reacting 2 equivalents of a hydrophobic aromatic dihalide with respect to the terminal.

  The amount of the terminal reactive group introduced is not particularly limited, but is 0.5% or more and 30% with respect to the first aromatic polymer compound (a) and the second aromatic polymer compound (b). Or less, more preferably 1% or more and 25% or less, and further preferably 2% or more and 20% or less. If it is 0.5% or more, the block copolymerization reaction will not be insufficient, and if it is 30% or less, the segment length will not be insufficient.

<Blockization method>
The method for synthesizing the block copolymer of the present invention comprises the steps (a) of the first aromatic polymer compound (hydrophilic segment) and (b) of the second fragrance into which a hydrophobic aromatic halogen group has been introduced. It is carried out by mixing and copolymerizing both the high molecular weight compound (hydrophobic segment). At this time, the hydrophobic aromatic halogen group introduced into the terminal of the first aromatic polymer compound (a) is hydrophobic and has high reaction activity.

  By introducing a hydrophobic reactive group into the hydrophilic segment, the compatibility of the terminal with the hydrophobic segment becomes good, and the blocking reaction easily proceeds. Moreover, the reaction temperature of blocking can be lowered by using a reactive group having high reaction activity. By performing the blocking reaction at a lower temperature, an effect of suppressing randomization of the block copolymer can be expected. In the present invention, the reaction activity refers to the activity for the polymerization reaction, and the activity is high when the polymerization reaction proceeds at 80 ° C. to 160 ° C.

  As a mixing method of the first aromatic polymer compound (hydrophilic segment) (a) used in the block copolymer of the present invention and the second aromatic polymer compound (hydrophobic segment) (b), There are a method of mixing the reaction solution as it is, a method of mixing the first aromatic polymer compound and the second aromatic polymer compound once purified and taken out, adding a solvent and dissolving again, etc. A method of mixing the reaction solution as it is is preferably used from the viewpoint of easy reaction operation.

  The solvent used for the synthesis of the block copolymer is not particularly limited as long as it dissolves the first aromatic polymer compound and the second aromatic polymer compound, but the first aromatic polymer compound is not limited. And a synthetic solvent for the second aromatic polymer compound is preferably used. At this time, a solvent used for synthesis or other solvent may be added to adjust the solution concentration and solubility. Specific reaction solvents are suitable from aprotic polar solvents such as N, N-dimethylacetamide, N, N-dimethylformamide, dimethyl sulfoxide, N-methyl-2-pyrrolidone, hexamethylphosphonamide, u-butyrolactone, etc. However, the present invention is not limited to these. A plurality of these solvents may be used as a mixture within a possible range. The amount of the solvent can be used in the range of 0.1 to 100 times the total weight of the monomer and catalyst to be reacted.

  The reaction temperature of the block copolymer is preferably 80 ° C. or higher and 160 ° C. or lower, more preferably 90 ° C. or higher and 150 ° C. or lower, even more preferably 100 ° C. or higher and 140 ° C. or lower. If it is 140 ° C. or less, randomization will not proceed excessively. The reaction time of the block copolymer is preferably 0.1 hours or more and 12 hours or less, preferably 0.2 hours or more and 8 hours or less, more preferably 0.5 hours or more and 4 hours or less, and more preferably 0.1 hours or more. For example, the block copolymerization reaction does not become insufficient, and if it is 12 hours or less, randomization does not proceed excessively.

<Molecular weight of segment>
The weight average molecular weight of the first aromatic polymer compound (a) is preferably 2000 or more and 150,000 or less, more preferably 7000 or more and 120,000 or less, and further preferably 7000 or more and 100,000 or less. If the weight average molecular weight is 2000 or more, the segment length will not be insufficient, and if it is 150,000 or less, the block copolymerization reaction will not be insufficient.

  The weight average molecular weight of the second aromatic polymer compound (b) is preferably 5000 or more and 150,000 or less, more preferably 7000 or more and 120,000 or less, and further preferably 7000 or more and 100,000 or less. If the weight average molecular weight is 5000 or more, the segment length will not be insufficient, and if it is 150,000 or less, the block copolymerization reaction will not be insufficient.

<Segment ratio>
The weight ratio [(a) / (b)] of the first aromatic polymer compound (a) and the second aromatic polymer compound (b) contained in the block copolymer of the present invention. The value of is preferably from 0.1 to 10.0, more preferably from 0.2 to 5.0, and still more preferably from 0.2 to 3.0. If the value of the weight ratio [(a) / (b)] is 0.1 or more, the proton conductivity is good, and if it is 10.0 or less, the durability of the block copolymer is not lowered.

<Amount of protonic acid group of block copolymer>
The amount of the protonic acid group of the block copolymer of the present invention is not particularly limited, but from the viewpoint of proton conductivity and durability, the value of ion exchange equivalent weight (EW value) is preferably from 300 to 1,000, and preferably from 400 900 or less is more preferable, and 500 or more and 800 or less is more preferable. Here, the ion exchange equivalent weight (EW value) refers to the weight (g) of the block copolymer per mole of proton acid groups. If the EW value is 300 or more, the durability does not deteriorate, and if it is 1000 or less, the proton conductivity is good.

<Structure of the first aromatic polymer compound>
The first aromatic polymer compound of (a) of the present invention includes a structural unit having an aromatic ring into which (α) a protonic acid group of the following formula (4) and / or the following formula (5) is introduced. It is preferable that

［式において、Ａは直接結合、−Ｏ−、−Ｓ−、−Ｓ（Ｏ）−、−Ｓ（Ｏ）_２−、−Ｃ（Ｏ）−、−Ｐ（Ｏ）（Ｃ_６Ｈ_５）−、−Ｃ（ＣＨ_３）_２−、−Ｃ（ＣＦ_３）_２−、−Ｃ_６Ｈ_４ＣＣ_６Ｈ_４−、または、

[In the formula, A represents a direct bond, —O—, —S—, —S (O) —, —S (O) ₂ —, —C (O) —, —P (O) (C ₆ H ₅ ). _{-, - C (CH 3)} 2 -, - C (CF 3) 2 -, - C 6 H 4 CC 6 H 4 -, or,

［式中Ｘはスルホン酸基、リン酸基、炭素数１〜６のアルキルスルホン酸基、炭素数１〜２０のアルキルコキシスルホン酸基、炭素数１〜６のアルキルリン酸基、炭素数１〜２０のアルキルコキシリン酸基から成るプロトン酸基を示す。ｍは１〜４の置換基数を表わし、ｆは４−ｍの置換基数を表わす。ｎは１〜４の置換基数を表わし、ｊは４−ｎの置換基数を表わす。］を示す。Ｒは水素または炭素数１〜２０のアルキル基、炭素数１〜２０のアルコキシ基、炭素数６〜２０のアリール基、炭素数６〜２０のアリールオキシ基又は炭素数２〜２０のアシル基、及びフッ素であり、Ｘは水素、スルホン酸基、リン酸基、炭素数１〜６のアルキルスルホン酸基、炭素数１〜２０のアルキルコキシスルホン酸基、炭素数１〜６のアルキルリン酸基、炭素数１〜２０のアルキルコキシリン酸基から成るプロトン酸基を示す。ｍは１〜４の置換基数を表わし、ｆは４−ｍの置換基数を表わす。ｎは１〜４の置換基数を表わし、ｊは４−ｎの置換基数を表わす。］

[Wherein X is a sulfonic acid group, a phosphoric acid group, an alkylsulfonic acid group having 1 to 6 carbon atoms, an alkyloxysulfonic acid group having 1 to 20 carbon atoms, an alkylphosphoric acid group having 1 to 6 carbon atoms, or a carbon number. A protonic acid group consisting of 1 to 20 alkylcoxyphosphate groups is shown. m represents the number of substituents of 1 to 4, and f represents the number of substituents of 4-m. n represents the number of substituents of 1 to 4, and j represents the number of substituents of 4-n. ] Is shown. R is hydrogen or 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 an acyl group having 2 to 20 carbon atoms, X is hydrogen, a sulfonic acid group, a phosphoric acid group, an alkyl sulfonic acid group having 1 to 6 carbon atoms, an alkyl oxysulfonic acid group having 1 to 20 carbon atoms, and an alkyl phosphoric acid having 1 to 6 carbon atoms. A protonic acid group composed of an alkylcoxyphosphoric acid group having 1 to 20 carbon atoms. m represents the number of substituents of 1 to 4, and f represents the number of substituents of 4-m. n represents the number of substituents of 1 to 4, and j represents the number of substituents of 4-n. ]

［式中Ｒは水素または炭素数１〜２０のアルキル基、炭素数１〜２０のアルコキシ基、炭素数６〜２０のアリール基、炭素数６〜２０のアリールオキシ基又は炭素数２〜２０のアシル基、及びフッ素であり、Ｘはスルホン酸基、リン酸基、炭素数１〜６のアルキルスルホン酸基、炭素数１〜２０のアルキルコキシスルホン酸基、炭素数１〜６のアルキルリン酸基、炭素数１〜２０のアルキルコキシリン酸基から成るプロトン酸基を示す。ｍは１から４の置換基数を表わし、ｆは４−ｍの置換基数を表わす。ｎは１から４の置換基数を表わし、ｊは４−ｎの置換基数を表わす。］
式（４）としては例えば、

[Wherein R is hydrogen or 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 an alkyl group having 2 to 20 carbon atoms. X is sulfonic acid group, phosphoric acid group, alkyl sulfonic acid group having 1 to 6 carbon atoms, alkyl oxysulfonic acid group having 1 to 20 carbon atoms, alkyl phosphorus having 1 to 6 carbon atoms. A protonic acid group composed of an acid group and an alkylcoxyphosphate group having 1 to 20 carbon atoms is shown. m represents the number of substituents of 1 to 4, and f represents the number of substituents of 4-m. n represents the number of substituents of 1 to 4, and j represents the number of substituents of 4-n. ]
As an expression (4), for example,

等が挙げられる。

Etc.

  As an expression (6), for example,

等が挙げられる。

Etc.

  The first aromatic polymer compound of (a) of the present invention includes a structural unit having a heterocyclic ring having a (β) protonic acid group introduced by the following formula (7) and / or formula (8). Preferably it is.

［式中Ａは直接結合、−Ｏ−、−Ｓ−、−Ｓ（Ｏ）−、−Ｓ（Ｏ）_２−、−Ｃ（Ｏ）−、−Ｐ（Ｏ）（Ｃ_６Ｈ_５）−、−Ｃ（ＣＨ_３）_２−、−Ｃ（ＣＦ_３）_２−、−Ｃ_６Ｈ_４ＣＣ_６Ｈ_４−または炭素数１〜１０のアルキリデン基を示す。Ｒは水素または炭素数１〜２０のアルキル基、炭素数１〜２０のアルコキシ基、炭素数６〜２０のアリール基、炭素数６〜２０のアリールオキシ基又は炭素数２〜２０のアシル基、及びフッ素であり、Ｘはスルホン酸基、リン酸基、炭素数１〜６のアルキルスルホン酸基、炭素数１〜２０のアルキルコキシスルホン酸基、炭素数１〜６のアルキルリン酸基、炭素数１〜２０のアルキルコキシリン酸基から成るプロトン酸基を示す。ｍは１〜５の置換基数を表わし、ｆは５−ｍの置換基数を表わす。ｎは１〜５の置換基数を表わし、ｊは５−ｎの置換基数を表わす。］
式（７）としては例えば、

[In the formula, A represents a direct bond, —O—, —S—, —S (O) —, —S (O) ₂ —, —C (O) —, —P (O) (C ₆ H ₅ ) —. _{, -C (CH 3) 2 -} , - C (CF 3) 2 -, - indicating the or alkylidene group having 1 to 10 carbon atoms _{- C 6 H 4 CC 6 H} 4. R is hydrogen or 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 an acyl group having 2 to 20 carbon atoms, X is a sulfonic acid group, a phosphoric acid group, an alkyl sulfonic acid group having 1 to 6 carbon atoms, an alkyloxy sulfonic acid group having 1 to 20 carbon atoms, an alkyl phosphoric acid group having 1 to 6 carbon atoms, The protonic acid group which consists of a C1-C20 alkylcoxyphosphoric acid group is shown. m represents the number of substituents of 1 to 5, and f represents the number of substituents of 5-m. n represents the number of substituents of 1 to 5, and j represents the number of substituents of 5-n. ]
As an expression (7), for example,

等が挙げられる。

Etc.

［式中Ｚは直接結合、−ＮＨ−、炭素数１〜１０のアルキルアミノ基、−ＮＣ_６Ｈ_４−、−Ｏ−、または−Ｓ−を示す。Ｒは水素または炭素数１〜２０のアルキル基、炭素数１〜２０のアルコキシ基、炭素数６〜２０のアリール基、炭素数６〜２０のアリールオキシ基又は炭素数２〜２０のアシル基、及びフッ素であり、Ｘはスルホン酸基、リン酸基、炭素数１〜６のアルキルスルホン酸基、炭素数１〜２０のアルキルコキシスルホン酸基、炭素数１〜６のアルキルリン酸基、炭素数１〜２０のアルキルコキシリン酸基から成るプロトン酸基を示す。ｍは１〜５の置換基数を表わし、ｆは５−ｍの置換基数を表わす。］
式（８）としては例えば、

[Wherein Z represents a direct bond, —NH—, an alkylamino group having 1 to 10 carbon atoms, —NC ₆ H ₄ —, —O—, or —S—. R is hydrogen or 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 an acyl group having 2 to 20 carbon atoms, X is a sulfonic acid group, a phosphoric acid group, an alkyl sulfonic acid group having 1 to 6 carbon atoms, an alkyloxy sulfonic acid group having 1 to 20 carbon atoms, an alkyl phosphoric acid group having 1 to 6 carbon atoms, The protonic acid group which consists of a C1-C20 alkylcoxyphosphoric acid group is shown. m represents the number of substituents of 1 to 5, and f represents the number of substituents of 5-m. ]
As formula (8), for example,

等が挙げられる。
ここで、（α）〜（β）の構造単位は、必ずしも一種類に限定されるものではなく、二種類以上の構造単位が含まれていてもよい。

Etc.
Here, the structural units (α) to (β) are not necessarily limited to one type, and two or more types of structural units may be included.

<Structure of the second aromatic polymer compound>
The second aromatic polymer compound (b) of the present invention preferably contains a structural unit having a (γ) aromatic ring of the following formula (9) and / or the following formula (11).

［式中Ａは直接結合、−Ｏ−、−Ｓ−、−Ｓ（Ｏ）−、−Ｓ（Ｏ）_２−、−Ｃ（Ｏ）−、−Ｐ（Ｏ）（Ｃ_６Ｈ_５）−、−Ｃ（ＣＨ_３）_２−、−Ｃ（ＣＦ_３）_２−、−Ｃ_６Ｈ_４ＣＣ_６Ｈ_４−、または

[In the formula, A represents a direct bond, —O—, —S—, —S (O) —, —S (O) ₂ —, —C (O) —, —P (O) (C ₆ H ₅ ) —. _{, -C (CH 3) 2 -} , - C (CF 3) 2 -, - C 6 H 4 CC 6 H 4 -, or

を示す。Ｂ、Ｃ，Ｄ，Ｅは水素または炭素数１〜２０のアルキル基、炭素数１〜２０のアルコキシ基、炭素数６〜２０のアリール基、炭素数６〜２０のアリールオキシ基又は炭素数２〜２０のアシル基、シアノ基、及びフッ素である。］
式（９）としては例えば、

Indicates. B, C, D, and E are hydrogen or 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. ˜20 acyl groups, cyano groups, and fluorine. ]
As formula (9), for example,

等が挙げられる。

Etc.

［式中Ｆ、Ｇは水素または炭素数１〜２０のアルキル基、炭素数１〜２０のアルコキシ基、炭素数６〜２０のアリール基、炭素数６〜２０のアリールオキシ基又は炭素数２〜２０のアシル基、シアノ基、及びフッ素である。］
式（１１）としては例えば、

[Wherein F and G are hydrogen or 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 to 2 carbon atoms. 20 acyl groups, cyano groups, and fluorine. ]
As the equation (11), for example,

等が挙げられる。

Etc.

  In addition, the second aromatic polymer compound of the present invention preferably contains a structural unit having a (δ) heterocycle of the following formula (12) and / or formula (13).

［式中Ａは直接結合、−Ｏ−、−Ｓ−、−Ｓ（Ｏ）−、−Ｓ（Ｏ）_２−、−Ｃ（Ｏ）−、−Ｐ（Ｏ）（Ｃ_６Ｈ_５）−、−Ｃ（ＣＨ_３）_２−、−Ｃ（ＣＦ_３）_２−、−Ｃ_６Ｈ_４ＣＣ_６Ｈ_４−または炭素数１〜１０のアルキリデン基を示す。Ｒは水素または炭素数１〜２０のアルキル基、炭素数１〜２０のアルコキシ基、炭素数６〜２０のアリール基、炭素数６〜２０のアリールオキシ基又は炭素数２〜２０のアシル基、及びフッ素であり、ｆ及びｊは１〜５の置換基数を表わす。］
式（１２）としては例えば、

[In the formula, A represents a direct bond, —O—, —S—, —S (O) —, —S (O) ₂ —, —C (O) —, —P (O) (C ₆ H ₅ ) —. _{, -C (CH 3) 2 -} , - C (CF 3) 2 -, - indicating the or alkylidene group having 1 to 10 carbon atoms _{- C 6 H 4 CC 6 H} 4. R is hydrogen or 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 an acyl group having 2 to 20 carbon atoms, And fluorine, and f and j represent 1 to 5 substituents. ]
As the equation (12), for example,

等が挙げられる。

Etc.

［式中Ｚは直接結合、−ＮＨ−、炭素数１〜１０のアルキルアミノ基、−ＮＣ_６Ｈ_４−、−Ｏ−、または−Ｓ−を示す。Ｒは水素または炭素数１〜２０のアルキル基、炭素数１〜２０のアルコキシ基、炭素数６〜２０のアリール基、炭素数６〜２０のアリールオキシ基又は炭素数２〜２０のアシル基、及びフッ素であり、ｆは１〜５の置換基数を表わす。］
式（１３）としては例えば、

[Wherein Z represents a direct bond, —NH—, an alkylamino group having 1 to 10 carbon atoms, —NC ₆ H ₄ —, —O—, or —S—. R is hydrogen or 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 an acyl group having 2 to 20 carbon atoms, And fluorine, and f represents the number of substituents of 1 to 5. ]
As an expression (13), for example,

等が挙げられる。
ここで、（γ）〜（δ）構造単位は、必ずしも一種類に限定されるものではなく、二種類以上の構造単位が含まれていてもよい。

Etc.
Here, the (γ) to (δ) structural units are not necessarily limited to one type, and two or more types of structural units may be included.

  The first aromatic polymer compound (a) of the present invention more preferably includes the structure of the following formula (14).

［式中Ａは直接結合、−Ｏ−、−Ｓ−、−Ｓ（Ｏ）−、−Ｓ（Ｏ）_２−、−Ｃ（Ｏ）−、−Ｐ（Ｏ）（Ｃ_６Ｈ_５）−、−Ｃ（ＣＨ_３）_２−、−Ｃ（ＣＦ_３）_２−、または−Ｃ_６Ｈ_４ＣＣ_６Ｈ_４−を示す。ｎは３以上の整数よりなる。］
式（１４）としては例えば、

[In the formula, A represents a direct bond, —O—, —S—, —S (O) —, —S (O) ₂ —, —C (O) —, —P (O) (C ₆ H ₅ ) —. _{, -C (CH 3) 2 -} , - C (CF 3) 2 -, or _{-C 6 H 4 CC 6 H 4} - shows a. n consists of an integer of 3 or more. ]
As formula (14), for example,

が挙げられる。

Is mentioned.

<(A) Amount of protonic acid group contained in the first aromatic polymer compound>
Although there is no restriction | limiting in particular in content of ((alpha)) and ((beta) each component contained in the 1st aromatic polymer compound of (a) of this invention, In the 1st aromatic polymer compound of (a) It is preferable that the amount of protonic acid groups is adjusted within a range of 250 to 600 in terms of ion exchange equivalent weight (EW value). Here, the ion exchange equivalent weight (EW value) refers to the weight (g) of the polymer compound per mole of proton acid groups. If the EW value of the first aromatic polymer compound is 250 or more, the solvent resistance of the block copolymer is not extremely lowered. If the EW value is 600 or less, the proton conductivity of the block copolymer is reduced. There is no decline.

<(A) Synthesis of First Aromatic Polymer Compound Having Hydrophobic Aromatic Halogen Group at Terminal and Protic Acid Group>
Next, a method for synthesizing the first aromatic polymer compound having a hydrophobic aromatic halogen group at the terminal (a) and a protonic acid group in the present invention will be described.
First, in order to introduce a hydrophobic aromatic halogen group at the terminal, the (I) precursor polymer compound of the first aromatic polymer compound is synthesized. (I) Precursor polymer compound is a chemical compound of (α) a structural unit having an aromatic ring introduced with a protonic acid group and (β) a structural unit precursor monomer having a heterocyclic ring introduced with a protonic acid group. It is preferably synthesized by combining them into a copolymer. Here, the method for producing the copolymer is not particularly limited, and any known method suitable for the combination of the respective structural units can be used.

  For example, (η) consisting of the components (α) and (β) of the present invention (η) a precursor monomer having two or more functional groups capable of substitution reaction, and (θ) two or more precursor monomers capable of reacting with this precursor monomer It can be synthesized by subjecting a precursor monomer having a functional group to a condensation reaction. Examples of the precursor monomer having two or more substitution-reactive functional groups of the (η) component are dihalongen, trihalogen, and tetrahalogenated compounds, and examples of halogen include fluorine, chlorine, bromine, and iodine. It is done. These halogenated monomers may be the same halogenated monomer or different types of halogenated monomers.

  In addition, as the monomer having two or more functional groups capable of substitution reaction of the (θ) component capable of reacting with the halogenated monomer, dihydroxy, trihydroxy, tetrahydroxy compound, dithiophenol, trithiophenol, tetrathiophenol Examples thereof include compounds, diamino, triamino, tetraamino compounds, dimonosubstituted amino, trimonosubstituted amino, and tetramonosubstituted amino. Monomers that can react with these halogenated monomers may be the same or different compounds.

  (I) As a method for introducing the hydrophobic reactive group of the present invention into the terminal of the precursor polymer compound, for example, by subjecting an excess amount of the (θ) component to a condensation reaction with respect to the (η) component. After synthesizing the precursor polymer compound (I) having a reactive group capable of reacting with a halogenated monomer at the terminal, 2 equivalents of decafluorobiphenyl is reacted with the excess (θ) component ( a) A first aromatic polymer compound having a perfluorobiphenyl group at a terminal and a protonic acid group can be synthesized.

  The synthesis of the first aromatic polymer compound having a hydrophobic aromatic halogen group at the terminal (a) and a protonic acid group of the present invention can be carried out in a solvent in the presence of a catalyst. As the catalyst, alkali catalysts such as potassium carbonate, calcium carbonate and cesium carbonate and metal halides such as cesium fluoride can be used. The catalyst amount can be 0.1 to 100 times the total number of moles of monomers to be reacted. As a reaction solvent, select an appropriate one from aprotic polar solvents such as N, N-dimethylacetamide, N, N-dimethylformamide, dimethyl sulfoxide, N-methyl-2-pyrrolidone, hexamethylphosphonamide, and u-butyrolactone. However, it is not limited to these. A plurality of these solvents may be used as a mixture within a possible range. The amount of the solvent can be used in the range of 0.1 to 100 times the total weight of the monomer and catalyst to be reacted. The reaction temperature is 0 ° C to 350 ° C, preferably 40 ° C to 260 ° C. The reaction time can be 2 hours to 500 hours.

<(B) Method for producing second aromatic polymer compound having a reactive group capable of reacting with the hydrophobic aromatic halogen group of (a) at the terminal and not having a protonic acid group>
Next, the method for synthesizing the second aromatic polymer compound having a reactive group capable of reacting with the hydrophobic aromatic halogen group of (a) at the terminal (b) of the present invention and having no proton acid group Will be described.
The second aromatic polymer compound (b) of the present invention can be synthesized using the same method as that for the precursor polymer compound (I). That is, it is preferably synthesized by chemically bonding the structural unit having a (γ) aromatic ring and the precursor monomer of the structural unit having a (δ) heterocyclic ring in the present invention to form a copolymer. Here, the method for producing the copolymer is not particularly limited, and any known method suitable for the combination of the respective structural units can be used.

  For example, the (γ) and (δ) components of the present invention, (ρ) a precursor monomer having two or more functional groups capable of substitution reaction, and (σ) two or more precursor monomers capable of reacting with the precursor monomer It can be synthesized by subjecting a precursor monomer having a functional group to a condensation reaction. Examples of the precursor monomer having two or more substitution-reactive functional groups of component (ρ) are dihalongen, trihalogen, and tetrahalogenated compounds. Examples of halogen include fluorine, chlorine, bromine, and iodine. It is done. These halogenated monomers may be the same halogenated monomer or different types of halogenated monomers.

  Moreover, as a monomer having two or more functional groups capable of substitution reaction of the (σ) component capable of reacting with the halogenated monomer, dihydroxy, trihydroxy, tetrahydroxy compound, dithiophenol, trithiophenol, tetrathiophenol Examples thereof include compounds, diamino, triamino, tetraamino compounds, dimonosubstituted amino, trimonosubstituted amino, and tetramonosubstituted amino. Monomers that can react with these halogenated monomers may be the same or different compounds.

  As a method for introducing a reactive group capable of reacting with the hydrophobic aromatic halogen group of (a) at the end of the second aromatic polymer compound of (b), for example, for the above component (ρ) It can be synthesized by subjecting an excess amount of the (σ) component to a condensation reaction. At this time, the excess amount of the (σ) component is preferably 0.5 equivalents relative to the terminal of the first aromatic polymer compound (a) from the viewpoint of increasing the molecular weight of the block copolymer. .

  The synthesis of the second aromatic polymer compound having a hydrophobic reactive group at the terminal (b) of the present invention and having a protonic acid group can be carried out in a solvent in the presence of a catalyst. As the catalyst, alkali catalysts such as potassium carbonate, calcium carbonate and cesium carbonate and metal halides such as cesium fluoride can be used. The catalyst amount can be 0.1 to 100 times the total number of moles of monomers to be reacted. As a reaction solvent, select an appropriate one from aprotic polar solvents such as N, N-dimethylacetamide, N, N-dimethylformamide, dimethyl sulfoxide, N-methyl-2-pyrrolidone, hexamethylphosphonamide, and u-butyrolactone. However, it is not limited to these. A plurality of these solvents may be used as a mixture within a possible range. The amount of the solvent can be used in the range of 0.1 to 100 times the total weight of the monomer and catalyst to be reacted. The reaction temperature is 0 ° C to 350 ° C, preferably 40 ° C to 260 ° C. The reaction time can be 2 hours to 500 hours.

<Purification method of block copolymer>
For the purification method of the polyelectrolyte compound of the present invention, conventionally known purification methods can be suitably used. For example, when the obtained protonic acid group-containing compound is in a solid state, it is washed with a solvent after filtration. It can be purified by separating it in the case of an oily state by drying and by removing the organic solvent by evaporation if dissolved in the reaction solution. Alternatively, water is added to the reaction solution containing the polymer electrolyte compound of the present invention, and if necessary, an alkali component is added and dissolved, and after separation into a solvent phase and an aqueous phase, acid precipitation, salting out, etc. from the aqueous phase It is also possible to purify by precipitation by the above method, washing with a solvent after filtration and drying. In the case where the reaction is carried out only with a sulfonating agent such as concentrated sulfuric acid, it is also effective to precipitate the compound by pouring the reaction solution into water for recovery and purification.

<Other ingredients>
Furthermore, the first aromatic polymer compound (a) of the present invention and the second aromatic polymer compound (b) of the present invention may contain repeating units other than (α) to (δ). Good. The repeating units other than (α) to (δ) in the present invention are not particularly limited, but for example, bonds of alkylene ethers such as ethylene oxide, propylene oxide and tetramethylene oxide, perfluoroalkylene ethers, aromatic imides and amides There are aromatic ethers and the like. In addition, the block copolymer of the present invention may contain other types of resins having different structures as long as the characteristics are not significantly deteriorated.

  Specific examples of the resin include polyethylene (PE), polypropylene (PP), polystyrene (PS), polymethyl methacrylate (PMMA), ABS resin, AS resin and other general-purpose resins, polyacetate (POM), Engineering plastics such as polycarbonate (PC), polyamide (PA: nylon), polyethylene terephthalate (PET) and polybutylene terephthalate (PBT), and polyphenylene sulfide (PPS), polyethersulfone (PES), polyketone (PK), polyimide ( PI), polycyclohexanedimethanol terephthalate (PCT), polyarylate (PAR), and various liquid crystal polymers (LCP) and other thermoplastic resins, epoxy resins, phenol resins, novolak resins, etc. Curable resin and the like, but not limited thereto.

  Moreover, in this case, it is preferable that the polymer electrolyte compound of the present invention is contained in an amount of 50% by mass or more and less than 100% by mass of the entire resin composition. More preferably, it is 70 mass% or more and less than 100 mass%. When the content of the block copolymer of the present invention is less than 50% by mass of the entire resin composition, the protonic acid group concentration in the resin composition of the polymer electrolyte membrane containing this resin composition is low, which is good Proton conductivity tends not to be obtained, and a unit containing a proton acid group becomes a discontinuous phase and tends to lower the mobility of protons conducted. The resin composition of the present invention can be used, for example, as necessary, for example, antioxidants, heat stabilizers, lubricants, tackifiers, plasticizers, crosslinking agents, viscosity modifiers, antistatic agents, antibacterial agents, antifoaming agents. Various additives such as an agent, a dispersant, and a polymerization inhibitor may be included.

<Polymer electrolyte membrane preparation method>
The polymer electrolyte membrane of the present invention can be prepared using the block copolymer prepared by the above preparation method. At this time, the block copolymer can be used alone or in combination of two or more. The polymer electrolyte membrane of the present invention can also be produced from the resin composition. A method for obtaining a polymer electrolyte membrane from a solution can be performed using a conventionally known method. For example, the polymer electrolyte membrane can be obtained by removing the solvent by heating, drying under reduced pressure, or immersing in a compound non-solvent that can be mixed with a solvent that dissolves the compound.

  The most preferable method for forming the polymer electrolyte membrane is casting from a solution, and the polymer electrolyte membrane can be obtained by removing the solvent from the cast solution as described above. Suitable solvents include aprotic polar solvents such as N, N-dimethylacetamide, N, N-dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone and hexamethylphosphonamide, and alcohols such as methanol and ethanol. However, the present invention is not limited to these. A plurality of these solvents may be used as a mixture within a possible range. The compound concentration in the solution is preferably in the range of 0.1% by mass to 50% by mass. When the compound concentration in the solution is less than 0.1% by mass, the moldability tends to deteriorate, and when it exceeds 50% by mass, the workability tends to deteriorate. When the solvent is an organic solvent, the solvent is preferably distilled off by heating or drying under reduced pressure. When combined with a compound having a similar solubility behavior, it is preferable in that good molding can be achieved.

  Moreover, in order to avoid decomposition | disassembly and alteration of a compound and a solvent, it can also dry at the lowest temperature possible under reduced pressure. Further, when the viscosity of the solution is high, when the substrate or the solution is heated and cast at a high temperature, the viscosity of the solution is lowered and the casting can be easily performed. The thickness of the solution at the time of casting is not particularly limited, but is preferably 0.1 μm or more and 10.0 μm or less, and more preferably 50 μm or more and 750 μm or less.

  If the thickness of the solution is thinner than 10 μm, the shape as a polymer electrolyte membrane tends to be lost, and if it is thicker than 1000 μm, a non-uniform polymer electrolyte membrane tends to be easily formed. As a method for controlling the cast thickness of the solution, a conventionally known method can be used. For example, the thickness can be controlled to a constant thickness using an applicator, a doctor blade, or the like, or the thickness can be controlled by the amount and concentration of the solution with a cast area constant using a glass petri dish or the like. The cast solution can obtain a more uniform polymer electrolyte membrane by adjusting the solvent removal rate.

  For example, in the case of heating, the evaporation rate can be reduced by lowering the temperature in the first stage. When immersed in water or the like, the coagulation rate of the compound can be adjusted by leaving the solution in air or an inert gas for an appropriate time. The polymer electrolyte membrane of the present invention can have any film thickness depending on the purpose, but is preferably as thin as possible from the viewpoint of proton conductivity. Specifically, it is preferably 5 to 200 μm or less, more preferably 5 to 75 μm or less, and most preferably 5 to 50 μm or less. If the thickness of the polymer electrolyte membrane is less than 5 μm, the handling of the polymer electrolyte membrane becomes difficult and a short circuit or the like tends to occur when a fuel cell is produced. If the thickness is greater than 200 μm, the electrical resistance value of the polymer electrolyte membrane is high. Therefore, the power generation performance of the fuel cell tends to decrease.

EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these. The evaluation method of the polymer electrolyte membrane obtained in this example is shown below.
<Measurement method and evaluation method>
Measurement of proton conductivity An evaluation cell shown in FIG. 1 was prepared for measurement of proton conductivity. A platinum electrode was used as the electrode, and the electrode interval was 1 cm. The cell was placed in a beaker containing pure water so that the electrolyte portion was immersed in pure water, and the resistance of the electrolyte membrane was measured by an AC impedance method. The evaluation method is that the cell is connected to a 1260 FREQUENCY RESPONSE ANALYSER made by Solartron with four terminals, and the real and imaginary parts of the total impedance detected when the AC frequency is arbitrarily changed from 10 kHz to 0.1 Hz are complex. Curve fitting was performed for several points in the Cole-Cole plot plotted on the surface, and the resistance of the electrolyte membrane was obtained from the value of the intercept.
This was substituted into Equation 1 to calculate proton conductivity.
σ = L / (R × S) (Formula 1)
σ: proton conductivity (S / cm), L: distance between electrodes (cm), R: resistance (Ω), S: membrane cross-sectional area (cm ² )

Evaluation of swelling rate The swelling rate was determined by immersing a polymer electrolyte membrane having a thickness of 50 to 150 μm cut out to 3 cm × 3 cm in water at 80 ° C. for 1 hour, and determining the area change before and after that from the following formula. The area after immersion was obtained by wiping the surface of the electrolyte membrane lightly with filter paper (5A), measuring the lengths of the vertical and horizontal sides, and calculating the product.

(3) Evaluation of methanol permeability In order to evaluate the methanol permeation amount, a self-made evaluation cell shown in FIG. 2 was used. In order to prevent deformation of the electrolyte membrane, steel filters (mesh 1000) were arranged on both sides of the cell opening. The solution inside the cell was stirred with a magnetic stirrer to suppress the concentration distribution in the vicinity of the electrolyte and in the vicinity of the sample outlet as much as possible. 180 g of purified water was added to the A cell and 200 g of purified water was added to the B cell, and the evaluation cell was placed in a thermostatic bath (60 ° C.) and left for 30 minutes. 20 g of methanol was added to the A cell and stirred at 400 rpm. The methanol concentration in the B cell was quantified by gas chromatography every 30 minutes, and the amount of methanol permeation with respect to time was plotted. The slope of this plot (methanol permeability was evaluated from the methanol permeation flux.

Measurement of Ion Exchange Equivalent Weight A polymer film made into a sulfonic acid type was dried under reduced pressure at 100 ° C. for 24 hours, then transferred to a glove box in an argon atmosphere and allowed to stand for 30 minutes, and then the weight was measured. This was added to 1.0 mol / l saline and titrated with a 0.05 mol / l ethanol solution of potassium hydroxide. The time when the pH reached 7 was taken as the equivalent point, and the ion exchange capacity was calculated from the amount of potassium hydroxide added at that time. Formula for calculating ion exchange capacity: ion exchange capacity [meq / g] = 0.05 [mmol / ml] × titrated amount of potassium hydroxide [ml] / weight of polymer film [g]

(Example 1)
<Synthesis of the first aromatic polymer compound (hydrophilic segment)>
A 1000 ml four-necked separable flask equipped with a Dean-Stark trap, condenser, stirrer and nitrogen supply tube was charged with sodium 4,4′-dichloro-3,3′-disulfonate diphenylsulfone monohydrate (SDCDPS, molecular weight). 509.25, 15.00 g, 0.0295 mol, 1.00 equivalent), 4,4 &'-dihydroxybiphenyl (Biphenol, molecular weight 186.21, 5.76 g, 0.0309 mol, 1.05 equivalent), carbonic acid Potassium (K ₂ CO ₃ , molecular weights 138.21, 4.92 g, 0.0356 mol, 1.21 equivalents), N-methylpyrrolidone 70 ml, toluene 50 ml were added, and heated at 160 ° C. for 1 hour and heated at 180 ° C. for 1 hour. After stirring and distilling off toluene, the temperature was raised to 200 ° C. and heated for 24 hours. After cooling the reaction solution to room temperature, decafluorobiphenyl (DFBP, molecular weight 334.11, 0.98 g, 0.0029 mol, 0.10 equivalent) was added, and the mixture was stirred at 130 ° C. for 2 hours to give the first fragrance. A reaction solution of a group high molecular compound was obtained. The obtained first aromatic polymer compound had a number average molecular weight of 34600 and a weight average molecular weight of 84800.

<Synthesis of second aromatic polymer compound (hydrophobic segment)>
A 500 ml eggplant flask equipped with a Dean-Stark trap, condenser, magnetic stirrer and nitrogen supply tube was charged with 4,4′-dichlorodiphenyl sulfone (DCDPS, molecular weight 287.16, 13.53 g, 0.0471 mol, 1.60). Equivalent)), 4,4′-dihydroxybiphenyl (Biphenol, molecular weight 186.21, 9.05 g, 0.0486 mol, 1.65 equivalent), potassium carbonate (K ₂ CO ₃ , molecular weight 138.21, 7.72 g, 0.0559 mol, 1.90 equivalents), 140 ml of N-methylpyrrolidone and 100 ml of toluene were added, and the mixture was heated and stirred at 160 ° C. for 1 hour and 180 ° C. for 1 hour to distill off the toluene, and then heated to 200 ° C. The mixture was heated and stirred for 12 hours to obtain a reaction liquid of the second aromatic polymer compound. The obtained second aromatic polymer compound had a number average molecular weight of 20,100 and a weight average molecular weight of 43,800.

<Synthesis of block copolymer>
The reaction vessel for the first aromatic polymer compound and the reaction vessel for the second aromatic polymer compound are connected by a silicon tube, and the reaction solution for the second aromatic polymer compound is completely removed at room temperature under a nitrogen atmosphere. One aromatic polymer compound was poured into a reaction vessel. At this time, the reaction vessel of the second aromatic polymer compound was washed with 200 ml of anhydrous N-methylpyrrolidone in a nitrogen atmosphere, and all the cleaning liquid was poured into the reaction vessel of the first aromatic polymer compound. The reaction mixture was heated and stirred at 140 ° C. for 1 hour.

<Purification of block copolymer>
After cooling to room temperature, the reaction solution was poured into 2000 ml of water to precipitate a block copolymer. The block copolymer was filtered, transferred to a 3000 ml beaker, 1500 ml of distilled water was added, and the mixture was heated from room temperature to 70 ° C. The block copolymer was filtered, transferred to a 3000 ml beaker, 1500 ml of 10% aqueous sulfuric acid was added, and the mixture was heated from room temperature to 70 ° C. After filtering the block copolymer, it was thoroughly washed with purified water, transferred to a 3000 ml beaker, 1500 ml of distilled water was added, and the mixture was heated from room temperature to 70 ° C. The block copolymer was filtered, washed thoroughly with purified water, transferred to a 3000 ml beaker, 1500 ml of distilled water and 500 ml of 5% aqueous sodium carbonate solution were added, and the mixture was heated from room temperature to 70 ° C. After filtering the block copolymer, it was washed thoroughly with purified water and dried in a hot air dryer at 140 ° C. for 6 hours to obtain the target block copolymer. The structural formula, yield, yield, weight average molecular weight, dispersity, and ion exchange equivalent weight (EW value) of the obtained block copolymer are as shown below.

収量：３４．２ｇ， 収率：８９％， 数平均分子量１８５０００，重量平均分子量４５００００，イオン交換当量重量値（ＥＷ値）７５７

Yield: 34.2 g, Yield: 89%, Number average molecular weight 185000, Weight average molecular weight 450,000, Ion exchange equivalent weight value (EW value) 757

<Preparation of block copolymer film>
Membranes were made to evaluate block copolymers.
After 15 g of the obtained block copolymer was dissolved in 85 g of N-methylpyrrolidone, it was filtered under pressure using a 1000 mesh filter, and further defoamed with a planetary stirring type defoaming device. This solution was cast on a glass plate using a bar coater having a gap of 400 μm, and then dried with a hot air drier at 60 ° C. for 15 minutes, 80 ° C. for 15 minutes, and 100 ° C. for 15 minutes. After taking out from the dryer, the film was peeled off from the glass plate, fixed to a stainless steel frame, poured again into the dryer, and dried at 160 ° C. for 30 minutes and 200 ° C. for 30 minutes. After cooling to room temperature, the membrane was removed from the frame and impregnated with 10% aqueous sulfuric acid for 12 hours at room temperature. After washing with distilled water, the water adhering to the membrane was wiped off with filter paper (5A) to prepare a block copolymer membrane.

<Preparation of MEA>
After wetting 1.0 g of catalyst-supported carbon particles (TEC10V50E, manufactured by Tanaka Kikinzoku Co., Ltd.) having a platinum-supported amount of 50% by mass with water, a Nafion (registered trademark) solution (manufactured by DuPont, “Nafion (registered trademark)” Catalyst paste A (viscosity 3.0 Pa · S) was prepared by mixing and dispersing 10 g of “5% solution” uniformly. Next, this catalyst paste A was applied to one side on the polymer electrolyte membrane obtained in Example 1 using a spray coater (manufactured by Nordson, slurry coating apparatus III (registered trademark)), and dried to form a catalyst layer. A was formed. Further, after wetting 1.0 g of catalyst-supported carbon particles (TEC61E54, manufactured by Tanaka Kikinzoku Co., Ltd.) having a platinum-supported amount of 30% by mass and a ruthenium-supporting amount of 24% by weight into Nafion (registered trademark) solution ( Catalyst paste B (viscosity 3.5 Pa · S) was prepared by mixing and dispersing 12 g of “Nafion (registered trademark)” 5%) manufactured by DuPont. By applying this catalyst paste B using a spray coater and drying, a catalyst layer B is formed on the opposite side of the catalyst layer A on the polymer electrolyte membrane obtained in Example 1, and obtained in Example 1. Catalyst layers A and B were formed on both sides of the polymer electrolyte membrane to obtain MEA. Subsequently, MEA 1 (catalyst layer A film thickness 150 μm, catalyst layer B film thickness 150 μm) was prepared by sandwiching the prepared MEA between press plates of a flat plate press and holding at 120 ° C. and 5 MPa for 3 minutes.

<Fabrication of fuel cell>
A Teflon (registered trademark) sheet for preventing fuel leakage, an anode cell, a cathode cell, and a current collector plate are arranged on both sides of the MEA 1 obtained in Example 1 as shown in FIG. Finally, the whole was fixed with a dedicated bolt to prepare a fuel cell (FC05-01SP-REF, manufactured by Electrochem, Inc., electrode area 5 cm ² , electrode average pore diameter 2 μm, electrode porosity 40%, serpentine flow).

(Comparative Example 1)
<Synthesis of the first aromatic polymer compound (hydrophilic segment)>
Sodium 4,4′-dichloro-3,3′-disulfonate diphenylsulfone monohydrate (SDCDPS, molecular weight 509.25, 15.00 g, 0.0295 mol, 1.00 equivalent), 4,4′-dihydroxy Biphenyl (Biphenol, molecular weight 186.21, 6.03 g, 0.0324 mol, 1.10 equivalent), potassium carbonate (K ₂ CO ₃ , molecular weight 138.21, 5.15 g, 0.0373 mol, 1.27 equivalent) ), N-methylpyrrolidone 70 ml, toluene 50 ml, and decafluorobiphenyl (DFBP, molecular weights 334.11, 1.97 g, 0.0059 mol, 0.20 equivalents) were all used in the same manner as in Example 1. It was. The obtained first aromatic polymer compound had a number average molecular weight of 25,200 and a weight average molecular weight of 54,900.

<Synthesis of second aromatic polymer compound (hydrophobic segment)>
4,4′-dichlorodiphenyl sulfone (DCDPS, molecular weight 287.16, 12.69 g, 0.0442 mol, 1.50 equivalents), 4,4′-dihydroxybiphenyl (Biphenol, molecular weight 186.21, 8.78 g, 0.0471 mol, 1.60 equivalents), potassium carbonate (K ₂ CO ₃ , molecular weight 138.21, 7.49 g, 0.0542 mol, 1.84 equivalents), N-methylpyrrolidone 70 ml, toluene 50 ml were used. Except for this, the same procedure as in Example 1 was performed. The obtained second aromatic polymer compound had a number average molecular weight of 13,300 and a weight average molecular weight of 25,600.

<Synthesis of block copolymer, purification of block copolymer, and production of block copolymer film>
All were carried out in the same manner as in Example 1. The structural formula, yield, yield, weight average molecular weight, dispersity, and ion exchange equivalent weight (EW value) of the obtained block copolymer are as shown below.

収量：３６．３ｇ， 収率：９３％， 数平均分子量６７８００，重量平均分子量２４６０００，イオン交換当量重量値（ＥＷ値）６８９

Yield: 36.3 g, Yield: 93%, Number average molecular weight 67800, Weight average molecular weight 246000, Ion exchange equivalent weight value (EW value) 689

<Preparation of MEA>
MEA2 was produced in the same manner as in Example 1 except that the polymer electrolyte membrane obtained in Comparative Example 1 was used instead of the polymer electrolyte membrane obtained in Example 1.

<Fabrication of fuel cell>
A fuel cell was produced in the same manner as in Example 1 except that the MEA 2 obtained in Comparative Example 1 was used.

(Comparative Example 2)
<Synthesis of the first aromatic polymer compound (hydrophilic segment)>
Sodium 4,4′-dichloro-3,3′-disulfonate diphenylsulfone monohydrate (SDCDPS, molecular weight 509.25, 15.00 g, 0.0295 mol, 1.00 equivalent), 4,4′-dihydroxy Biphenyl (Biphenol, molecular weight 186.21, 5.76 g, 0.0309 mol, 1.05 equivalent), potassium carbonate (K ₂ CO ₃ , molecular weight 138.21, 4.92 g, 0.0356 mol, 1.21 equivalent) ), N-methylpyrrolidone 70 ml, toluene 50 ml, and decafluorobiphenyl (DFBP, molecular weight 334.11, 0.98 g, 0.0029 mol, 0.10 equivalent) were all used in the same manner as in Example 1. It was. The obtained first aromatic polymer compound had a number average molecular weight of 41500 and a weight average molecular weight of 102,000.

<Synthesis of second aromatic polymer compound (hydrophobic segment)>
4,4′-dichlorodiphenylsulfone (DCDPS, molecular weight 287.16, 13.53 g, 0.0471 mol, 1.60 equivalents), 4,4′-dihydroxybiphenyl (Biphenol, molecular weight 186.21, 9.05 g, 0.0486 mol, 1.65 equivalent), potassium carbonate (K ₂ CO ₃ , molecular weight 138.21, 7.72 g, 0.0559 mol, 1.90 equivalent), N-methylpyrrolidone 70 ml, toluene 50 ml were used. Except for this, the same procedure as in Example 1 was performed. The obtained second aromatic polymer compound had a number average molecular weight of 15800 and a weight average molecular weight of 38,300.

<Synthesis of block copolymer, purification of block copolymer, and production of block copolymer film>
All were carried out in the same manner as in Example 1. The structural formula, yield, yield, weight average molecular weight, dispersity, and ion exchange equivalent weight (EW value) of the obtained block copolymer are as shown below.

収量：３４．３ｇ， 収率：８９％， 数平均分子量３６３００，重量平均分子量３４００００，イオン交換当量重量値（ＥＷ値）７１１

Yield: 34.3 g, Yield: 89%, Number average molecular weight 36300, Weight average molecular weight 340000, Ion exchange equivalent weight value (EW value) 711

<Preparation of MEA>
MEA3 was produced in the same manner as in Example 1 except that the polymer electrolyte membrane obtained in Comparative Example 2 was used instead of the polymer electrolyte membrane obtained in Example 1.

<Fabrication of fuel cell>
A fuel cell was produced in the same manner as in Example 1 except that the MEA 3 obtained in Comparative Example 1 was used.
Table 1 summarizes the physical property values of Example 1 and Comparative Examples 1 and 2. FIG. 3 shows a fuel cell using the MEA of Example 1 and Comparative Examples 1 and 2 on the condition that a 10 mass% methanol aqueous solution is 1 ml / min on the anode side, air is 300 ml / min on the cathode side, and the cell temperature is 60 ° C. The output characteristics at are shown. FIG. 4 shows the output characteristics of the fuel cells using the MEAs of Example 1 and Comparative Examples 1 and 2 over time under the same conditions as in FIG. Table 1 is a table showing the EW values of Example 1 and Comparative Examples 1 and 2, the molecular weight, the film thickness, the proton conductivity, the methanol permeation amount, and the swelling rate of the hydrophilic segment and the hydrophobic segment.

  The present invention provides an MEA with a polymer electrolyte membrane that reduces methanol crossover while maintaining high proton conductivity by suppressing the swelling rate with respect to water to 15% or less with a proton conductivity of 0.1 S / cm or more. By using it, it is possible to obtain a membrane / electrode assembly (MEA) having good bondability and output characteristics between the polymer electrolyte membrane and the electrode.

It is a figure which shows the structure of the cell for proton conductivity measurement. It is a figure which shows the cell for methanol permeability coefficient evaluation. It is a figure which shows the structure of a fuel cell. It is a figure which shows the output characteristic of a fuel cell. It is a figure which shows the output characteristic with respect to time passage of a fuel cell.

Claims (18)

  A membrane / electrode assembly comprising a polymer electrolyte membrane having a proton conductivity of 0.1 S / cm or more and a swelling ratio with respect to water of 15% or less.   2. The membrane / electrode assembly according to claim 1, wherein an electrode is formed on the polymer electrolyte membrane having a proton conductivity of 0.1 S / cm or more and a swelling ratio of 15% or less with respect to water by a spray coating method. .   Forming an electrode on a polymer electrolyte membrane having a proton conductivity of 0.1 S / cm or more and a swelling ratio with respect to water of 15% or less by bonding a gas diffusion electrode (hereinafter referred to as GDE). The membrane electrode assembly according to claim 1, wherein   2. The membrane / electrode assembly according to claim 1, wherein an electrode is formed by a transfer method on a polymer electrolyte membrane having a proton conductivity of 0.1 S / cm or more and a swelling ratio with respect to water of 15% or less.   2. The membrane electrode assembly according to claim 1, wherein the electrode is directly formed on the polymer electrolyte membrane by spray coating a catalyst slurry containing a noble metal catalyst.   6. The membrane electrode assembly according to claim 5, wherein the catalyst slurry is a composition capable of dissolving the noble metal catalyst, the electrolyte binder, and the electrolyte binder and dispersing the noble metal catalyst.   A polymer electrolyte membrane having a proton conductivity of 0.1 S / cm or more and a swelling ratio with respect to water of 15% or less is (a) a first aromatic having a perfluorobiphenyl group at the terminal and having a proton acid group Copolymer with a polymer compound and (b) a second aromatic polymer compound having a reactive group capable of reacting with the perfluorobiphenyl group of (a) and having no proton acid group The membrane electrode assembly according to any one of claims 1 to 6, wherein the membrane electrode assembly comprises a polymer electrolyte membrane. (A) The first aromatic polymer compound has a hydrophobic aromatic halogen group, and the hydrophobic aromatic halogen group is a structural unit of the following formula (1): The membrane electrode assembly as described.

[Wherein A is _{S (O) -, - S} (O) 2 -, - C (O) -, or _{-P (O) (C 6 H} 5) - shows the. B, C, D, and E represent hydrogen or an alkyl group having 1 to 20 carbon atoms, a fluoroalkyl group having 1 to 20 carbon atoms, a cyano group, and fluorine. F represents fluorine. ] (A) Structure in which the first aromatic polymer compound has a hydrophobic aromatic halogen group, and the hydrophobic aromatic halogen group has a heterocycle of the following formula (2) and / or formula (3) The membrane electrode assembly according to claim 7, wherein the membrane electrode assembly is a unit.

[In the formula, A represents a direct bond, —O—, —S—, —S (O) —, —S (O) ₂ —, —C (O) —, —P (O) (C ₆ H ₅ ) —. _{, -C (CH 3) 2 -} , - C (CF 3) 2 -, or _{-C 6 H 4 CC 6 H 4} - shows a. R is hydrogen or 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 an acyl group having 2 to 20 carbon atoms, And fluorine, and f and j represent 1 to 5 substituents. F represents fluorine. ]

[Wherein Z represents a direct bond, —NH—, an alkylamino group having 1 to 10 carbon atoms, —NC ₆ H ₄ —, —O—, or —S—. R is hydrogen or 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 an acyl group having 2 to 20 carbon atoms, And fluorine, and f represents the number of substituents of 1 to 5. ]   The membrane electrode assembly according to any one of claims 7 to 9, wherein the reactive group capable of reacting with the perfluorobiphenyl group of (a) in (b) is a phenolic hydroxyl group.   (A) The weight average molecular weight of the first aromatic polymer compound is 2,000 to 150,000, and (b) the weight average molecular weight of the second aromatic polymer compound is 2,000 to 150,000. The membrane electrode assembly according to any one of claims 7 to 10.   The value of the weight ratio [(a) / (b)] between the first aromatic polymer compound (a) and the second aromatic polymer compound (b) is 0.1 or more and 10.0 or less. The membrane electrode assembly according to any one of claims 7 to 11, wherein the membrane electrode assembly is provided. The first aromatic polymer compound of (a) has an aromatic ring into which the (α) protonic acid group of the following formula (4) and / or the following formula (5) and / or the following formula (6) is introduced. The membrane electrode assembly according to any one of claims 7 to 12, comprising a structural unit.

[In the formula, A represents a direct bond, —O—, —S—, —S (O) —, —S (O) ₂ —, —C (O) —, —P (O) (C ₆ H ₅ ). _{-, - C (CH 3)} 2 -, - C (CF 3) 2 -, - C 6 H 4 CC 6 H 4 -, or,

[Wherein X is a sulfonic acid group, a phosphoric acid group, an alkylsulfonic acid group having 1 to 6 carbon atoms, an alkyloxysulfonic acid group having 1 to 20 carbon atoms, an alkylphosphoric acid group having 1 to 6 carbon atoms, or a carbon number. A protonic acid group consisting of 1 to 20 alkylcoxyphosphate groups is shown. m represents the number of substituents of 1 to 4, and f represents the number of substituents of 4-m. n represents the number of substituents of 1 to 4, and j represents the number of substituents of 4-n. ] Is shown. R is hydrogen or 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 an acyl group having 2 to 20 carbon atoms, X is hydrogen, a sulfonic acid group, a phosphoric acid group, an alkyl sulfonic acid group having 1 to 6 carbon atoms, an alkyl oxysulfonic acid group having 1 to 20 carbon atoms, and an alkyl phosphoric acid having 1 to 6 carbon atoms. A protonic acid group composed of an alkylcoxyphosphoric acid group having 1 to 20 carbon atoms. m represents the number of substituents of 1 to 4, and f represents the number of substituents of 4-m. n represents the number of substituents of 1 to 4, and j represents the number of substituents of 4-n. ]

[Wherein R is hydrogen or 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 an alkyl group having 2 to 20 carbon atoms. X is sulfonic acid group, phosphoric acid group, alkyl sulfonic acid group having 1 to 6 carbon atoms, alkyl oxysulfonic acid group having 1 to 20 carbon atoms, alkyl phosphorus having 1 to 6 carbon atoms. A protonic acid group composed of an acid group and an alkylcoxyphosphate group having 1 to 20 carbon atoms is shown. m represents the number of substituents of 1 to 4, and f represents the number of substituents of 4-m. n represents the number of substituents of 1 to 4, and j represents the number of substituents of 4-n. ] The first aromatic polymer compound of (a) includes a structural unit having a heterocycle having a (β) protonic acid group introduced by the following formula (7) and / or formula (8): The membrane electrode assembly according to any one of claims 7 to 13.

[In the formula, A represents a direct bond, —O—, —S—, —S (O) —, —S (O) ₂ —, —C (O) —, —P (O) (C ₆ H ₅ ) —. _{, -C (CH 3) 2 -} , - C (CF 3) 2 -, - indicating the or alkylidene group having 1 to 10 carbon atoms _{- C 6 H 4 CC 6 H} 4. R is hydrogen or 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 an acyl group having 2 to 20 carbon atoms, X is a sulfonic acid group, a phosphoric acid group, an alkyl sulfonic acid group having 1 to 6 carbon atoms, an alkyloxy sulfonic acid group having 1 to 20 carbon atoms, an alkyl phosphoric acid group having 1 to 6 carbon atoms, The protonic acid group which consists of a C1-C20 alkylcoxyphosphoric acid group is shown. m represents the number of substituents of 1 to 5, and f represents the number of substituents of 5-m. n represents the number of substituents of 1 to 5, and j represents the number of substituents of 5-n. ]

[Wherein Z represents a direct bond, —NH—, an alkylamino group having 1 to 10 carbon atoms, —NC ₆ H ₄ —, —O—, or —S—. R is hydrogen or 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 an acyl group having 2 to 20 carbon atoms, X is a sulfonic acid group, a phosphoric acid group, an alkyl sulfonic acid group having 1 to 6 carbon atoms, an alkyloxy sulfonic acid group having 1 to 20 carbon atoms, an alkyl phosphoric acid group having 1 to 6 carbon atoms, The protonic acid group which consists of a C1-C20 alkylcoxyphosphoric acid group is shown. m represents the number of substituents of 1 to 5, and f represents the number of substituents of 5-m. ] The second aromatic polymer compound of (b) includes a structural unit having a (γ) aromatic ring of the following formula (9) and / or the following formula (10) and / or the following formula (11). The membrane electrode assembly according to any one of claims 7 to 14, wherein

[In the formula, A represents a direct bond, —O—, —S—, —S (O) —, —S (O) ₂ —, —C (O) —, —P (O) (C ₆ H ₅ ) —. _{, -C (CH 3) 2 -} , - C (CF 3) 2 -, - C 6 H 4 CC 6 H 4 -, or

Indicates. B, C, D, and E are hydrogen or 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. ˜20 acyl groups, cyano groups, and fluorine. ]

[Wherein F and G are hydrogen or 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 to 2 carbon atoms. 20 acyl groups, cyano groups, and fluorine. ] The second aromatic polymer compound of (b) contains a structural unit having a (δ) heterocyclic ring of the following formula (12) and / or formula (13): The membrane electrode assembly according to any one of -15.

[In the formula, A represents a direct bond, —O—, —S—, —S (O) —, —S (O) ₂ —, —C (O) —, —P (O) (C ₆ H ₅ ) —. _{, -C (CH 3) 2 -} , - C (CF 3) 2 -, - indicating the or alkylidene group having 1 to 10 carbon atoms _{- C 6 H 4 CC 6 H} 4. R is hydrogen or 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 an acyl group having 2 to 20 carbon atoms, And fluorine, and f and j represent 1 to 5 substituents. ]

[Wherein Z represents a direct bond, —NH—, an alkylamino group having 1 to 10 carbon atoms, —NC ₆ H ₄ —, —O—, or —S—. R is hydrogen or 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 an acyl group having 2 to 20 carbon atoms, And fluorine, and f represents the number of substituents of 1 to 5. ]   (Α) In the structural unit having an aromatic ring into which a proton acid group is introduced, the proton acid group is a sulfonic acid group or / and a phosphoric acid group. Joined body. The membrane electrode assembly according to claim 7, wherein the first aromatic polymer compound (a) is represented by the following formula (14).

[In the formula, A represents a direct bond, —O—, —S—, —S (O) —, —S (O) ₂ —, —C (O) —, —P (O) (C ₆ H ₅ ) —. _{, -C (CH 3) 2 -} , - C (CF 3) 2 -, or _{-C 6 H 4 CC 6 H 4} - shows a. n consists of an integer of 3 or more. ]

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