JP2009129703A - Dendronized polymer electrolyte, manufacturing method thereof, solid polymer electrolyte membrane, electrode for solid polymer fuel cell, and fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydrocarbon-based polymer electrolyte excelling in heat resistance and mechanical strength, and also excelling in high ionic conductivity regardless of a humidification condition; and a solid polymer electrolyte membrane. <P>SOLUTION: This dendronized polymer electrolyte comprises a main chain having an aromatic group-containing structure represented by general formula (1), and a side chain having an ion conductive group in its terminal group. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a novel dendronized polymer (branched polymer) electrolyte, a production method thereof, a solid polymer electrolyte membrane, and a fuel cell using the same. More specifically, a polymer electrolyte excellent in ion conductivity and durability suitable for an electrolyte membrane used in a fuel cell, water electrolysis, hydrohalic acid electrolysis, salt electrolysis, oxygen concentrator, humidity sensor, gas sensor, etc. The present invention relates to a solid polymer electrolyte membrane.

  A solid polymer electrolyte is a solid polymer material having an electrolyte group such as a sulfonic acid group in a polymer chain, and has a property of binding firmly to a specific ion or selectively transmitting a cation or an anion. Therefore, it is formed into particles, fibers, or membranes and used for various applications such as electrodialysis, diffusion dialysis, and battery diaphragm.

  For example, a fuel cell is one that converts the chemical energy of fuel directly into electric energy by electrochemically oxidizing fuel such as hydrogen or methanol in the cell, and has recently been a clean electric energy supply source. It is attracting attention as. In particular, a polymer electrolyte fuel cell using a proton exchange membrane as an electrolyte is expected as a power source for an electric vehicle because it has a high output density and can be operated at a low temperature.

  The basic structure of such a polymer electrolyte fuel cell is composed of an electrolyte membrane and a pair of gas diffusion electrodes having a catalyst layer bonded to both surfaces thereof, and a structure in which a current collector is disposed on both sides thereof. It is made up of. Then, hydrogen or methanol as fuel is supplied to one gas diffusion electrode (anode), oxygen or air as oxidant is supplied to the other gas diffusion electrode (cathode), and an external load is applied between both gas diffusion electrodes. By connecting the circuit, it operates as a fuel cell. At this time, protons generated at the anode move to the cathode side through the electrolyte membrane, and react with oxygen at the cathode to generate water. Here, the electrolyte membrane functions as a proton transfer medium and a hydrogen gas or oxygen gas diaphragm. Accordingly, the electrolyte membrane is required to have high proton conductivity, strength, and chemical stability.

  On the other hand, as a catalyst for a gas diffusion electrode, a catalyst in which a noble metal such as platinum is supported on a carrier having electron conductivity such as carbon is generally used. For the purpose of mediating proton transfer onto the catalyst supported on the gas diffusion electrode and increasing the utilization efficiency of the catalyst, a proton conductive polymer electrolyte is also used as an electrode catalyst binder. Alternatively, a fluorine-containing polymer having a sulfonic acid group such as perfluorosulfonic acid polymer, which is the same as the ion exchange membrane, can be used. Here, the fluorine-containing polymer having a sulfonic acid group, which is an electrocatalyst binder, also serves as a binder for the catalyst of the gas diffusion electrode or as a bonding agent for improving the adhesion between the ion exchange membrane and the gas diffusion electrode. It can also be made.

  By the way, the fluorine-based electrolyte typified by the perfluorosulfonic acid membrane has a very high chemical stability because it has a C—F bond. For the above-described fuel cell, water electrolysis, or salt electrolysis In addition to these solid polymer electrolyte membranes, they are also used as solid polymer electrolyte membranes for hydrohalic acid electrolysis, and further widely applied to humidity sensors, gas sensors, oxygen concentrators, etc. using proton conductivity. It is what.

  As an electrolyte membrane of a fuel cell, a fluorine-based membrane having perfluoroalkylene as a main skeleton and partially 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 is mainly used. . Fluorine electrolyte membranes typified by perfluorosulfonic acid membranes have been used as electrolyte membranes used under severe conditions because of their very high chemical stability. As such a fluorine-based electrolyte membrane, Nafion membrane (registered trademark, Du Pont), Dow membrane (Dow Chemical), Aciplex membrane (registered trademark, Asahi Kasei Kogyo Co., Ltd.), Flemion membrane (registered trademark, Asahi Glass) Etc.) are known.

  However, the conventionally proposed perfluorosulfonic acid-based solid electrolyte membrane has the disadvantages that it is difficult to manufacture and is very expensive, and the perfluorosulfonic acid-based electrolyte has heat resistance, chemical resistance, and ion conductivity. However, there is a problem that the high-temperature operation of a fuel cell or the like cannot be sufficiently handled.

  Therefore, it has been desired to develop an ion conductive / ion exchange material in place of the perfluorosulfonic acid electrolyte. For example, in Patent Documents 1 to 3 below, as a polymer electrolyte containing terminal sulfonic acid groups, which can be applied to a fuel cell, polystyrene or a specific polyimide as a main chain, and a structure branched into side chains and a sulfonic acid group are included. An introduced polyelectrolyte is disclosed.

JP 2004-35891 A JP 2005-126721 A JP-A-2005-232456

  The polymer electrolytes disclosed in the above Patent Documents 1 to 3 have a certain heat resistance. However, in order to replace the perfluorosulfonic acid-based electrolyte, the ion is used regardless of humidification conditions of high and low humidification. There was a problem of poor conductivity.

  The object of the present invention is to solve the above-mentioned problems of the conventional polymer electrolyte, and not only has excellent heat resistance and mechanical strength but also high ionic conductivity regardless of humidification conditions of high and low humidification. It is an object of the present invention to provide a hydrocarbon-based polymer electrolyte and a solid polymer electrolyte membrane excellent in the above. Another object of the present invention is to realize an excellent solid polymer electrolyte fuel cell using the hydrocarbon-based polymer electrolyte.

As a result of earnest research, the present inventors have found that the problems and problems of the polymer electrolytes disclosed in the above Patent Documents 1 to 3 occur.
(1) The distance between the ion conducting groups is separated (2) The ion conducting path (path) is broken in the electrolyte membrane (3) The mobility of the side chain attached to the conducting group is low (4 ) There is a limit to the improvement of acid density in the synthesis reaction. (5) It has been found that accurate phase separation on the molecular structure has not been made, and a novel polymer electrolyte that solves these problems and problems. Reached.

  That is, first, the present invention is an invention of a dendronized polymer (branched polymer) electrolyte, and has a main chain having an aromatic group-containing structure represented by the following general formula (1) and a terminal group. It consists of a side chain having an ion conductive group.

（式中、Ａ、Ａ’はそれぞれ独立して芳香族系繰り返し単位であり、ｍ＝５〜１００００、ｎ＝０〜１００００、Ｂは連結基でありｂ＝０〜５、Ｃは２個以上の分岐点を有する分岐構造単位であり、ｃ＝０〜５、Ｄは末端にイオン伝導基を有するイオン伝導単位であり、ｄ＝１〜３であり、Ｅは疎水性基であり、ｅ＝０〜３、Ｆは親水性基であり、ｆ＝０〜３である。連結基ＢはＡ’とＣの間だけでなく、ＣとＤの間、Ｃの構造中、又はＤの構造中に含有されていてもよい。）
ここで、前記高分子電解質の分子の、主鎖と側鎖の間及び／又は側鎖間の空隙にイオン伝導性物質及び／又は保水性物質が存在していることが好ましい。

(In the formula, A and A ′ are each independently an aromatic repeating unit, m = 5 to 10,000, n = 0 to 10,000, B is a linking group, b = 0 to 5, and C is 2 or more. Branch units having the following branch points: c = 0 to 5, D is an ion conductive unit having an ion conductive group at the terminal, d = 1 to 3, E is a hydrophobic group, e = 0 to 3, F is a hydrophilic group, and f = 0 to 3. The linking group B is not only between A ′ and C, but also between C and D, in the structure of C, or in the structure of D. It may be contained in
Here, it is preferable that an ion-conducting substance and / or a water-retaining substance is present in the space between the main chain and the side chain and / or between the side chains of the polymer electrolyte molecule.

The dendronized polymer electrolyte of the present invention is
(1) Heat resistance and strength are exhibited by the main chain having an aromatic group-containing structure,
(2) The acid density is increased by intensively imparting ion conductive groups to the branched side chain ends,
(3) By reducing the distance between ion conductive groups, high ionic conductivity is expected even with low humidification,
(4) By concentrating the ion conductive group around the side chain, it is possible to substantially form a phase separation structure and to connect ion conductive paths (routes).
(5) By adding a side chain structure, the number of places where sulfonic acid groups can be added can be increased, and the substantial acid density can be improved.
(6) The mobility of the ion conductive group and the bulk of the side chain are expressed by the linking group and the branched structural unit between the main chain and the ion conductive group to increase the free volume of the molecule,
(7) Further, an ion conductive path is ensured by allowing an ion conductive substance and / or a water retention substance to exist between the main chain and the side chain and / or between the side chains.
It has excellent properties. As a result, the dendronized polymer electrolyte of the present invention has excellent ionic conductivity both in a low humidified state and in a highly humidified state.

  The molecular weight of the dendronized polymer electrolyte of the present invention is 100 or more in terms of weight average molecular weight. Here, when the weight average molecular weight is less than 100, the function as a solid electrolyte cannot be sufficiently exhibited.

  As the main chain having an aromatic group-containing structure, known heat-resistant polymers can be widely used. By the main chain composed of the repeating units A and A ′, basic physical properties of the dendronized polymer electrolyte such as heat resistance, mechanical strength and flexibility are exhibited. Specifically, as a main chain composed of the repeating units A and A ′, aromatics connected by polyphenylene, naphthalene, aromatic polyether, aromatic polythioether, aromatic polysulfone, aromatic polyethersulfone, and alkylene groups. Group, aromatic polyamide, aromatic polyester, aromatic polyimide, aromatic polyetherimide, aromatic polyamideimide, aromatic polyketone, aromatic polyetheretherketone, aromatic polyhydrazide, aromatic polyimine, polyoxadiazole, Preferable examples include one or more selected from the group consisting of polybenzoxazole, polybenzimidazole, alkyl-substituted compounds thereof, and hydroxyl-substituted compounds.

  More specifically, the repeating units A and A ′ are exemplified by one or a combination of two or more selected from the following chemical formulas.

The linking group B may not be present, but the presence of the linking group B enhances the mobility of the side chain in cooperation with a branching structural unit described later while ensuring the heat resistance of the main chain. The linking group B may be contained not only between A ′ and C, but also between C and D, in the structure of C, or in the structure of D.

Specifically, as the linking group B, an ether group, a carbonyl group, a thioether group, a sulfone group, an amide group, a bissulfonimide group (—SO ₂ NHSO ₂ —), a sulfone carbonimide group (—SO ₂ NHCO—), One or more types selected from the group of a biscarbonimide group (—CONHCO—) and an alkylene group are preferably exemplified.

  The branched structural unit C having two or more branch points may not be present in all side chains in the molecule, but is present in at least a part. The branched structural unit C results in a dendronized polymer structure. By adding an ion conductive group to the end of the branched side chain, the acid density is increased to improve the ion conductivity, and the mobility and side chain of the ion conductive group together with the linking group. To increase the free volume of the molecule. Specifically, as the branched structural unit C, one or more selected from the group represented by the following general formula or one or more selected from these repeating structures are preferably selected.

The ion conductive unit D having an ion conductive group at the terminal may not be present in all side chains in the molecule, but is present in at least a part. The ion conductivity as an electrolyte is exhibited by the ion conduction unit D. In some cases, the ion conducting unit D is protonated by hydrolysis or the like. Specifically, as the ion conduction unit D, one or more selected from the group represented by the following general formula (Rf is a structure having a fluorine atom at least in part, Ar is at least partly Which is a structure having an aromatic ring) is preferably selected.

The hydrophobic group E substituted with the repeating unit A constituting the main chain is an optional substituent, and may not be present at all in the repeating unit A in the molecule, or may be partially substituted. The hydrophobic group E promotes separation of the hydrophilic phase and the hydrophobic phase within the electrolyte membrane, and the hydrophilic phase exhibits improved continuity of ion channels, and the hydrophobic phase exhibits improved mechanical properties due to cohesive force. Specifically, the hydrophobic group E needs to have a low polarity structure that does not include a hydroxy group, a carboxy group, an amino group, a carbonyl group, a thiol group, or the like. Specific examples include the following hydrophobic groups.

１個の繰り返し単位Ａに置換する疎水性基Ｅの個数ｅは０、１、２、３程度である。

The number e of hydrophobic groups E substituted with one repeating unit A is about 0, 1, 2, or 3.

  The hydrophilic group F substituted with the repeating unit A ′ constituting the main chain is an optional substituent and may not be present at all in the repeating unit A ′ in the molecule or may be partially substituted. Specifically, the hydrophilic group F is preferably exemplified by one or more selected from a hydroxy group, a carboxy group, an amino group, a carbonyl group, a nitro group, and a thiol group. The number f of hydrophilic groups F substituted for one repeating unit A ′ is about 0, 1, 2, or 3.

  Preferable examples of the ion conductive material and / or water retention material added to the dendronized polymer electrolyte as an optional component include various inorganic salts, organic salts, silica, titania, alumina, zirconia and the like.

Second, the present invention is an invention of a method for producing the above dendronized polymer electrolyte,
(1) Using a side chain of a polymer compound having an aromatic group-containing structure as a reaction point, reacting a branched structural unit having two or more branch points with or without a linking group,
(2) Next, an ion conductive group having an ion conductive group as a terminal group is reacted with the branch point.
Or (1) synthesizing a side chain having a branched structure in advance,
(2) Next, the side chain is bonded to a reaction point in the main chain having an aromatic group-containing structure.
It is characterized by that.

Furthermore, as an optional step,
(3) An ion conductive material and / or a water retention material is added, and the ion conductive material and / or water retention in the space between the main chain and the side chain and / or between the side chains of the molecule of the polyelectrolyte. The presence of sex substances,
(4) When the density of the ion conductive group is high, it is solidified by post-crosslinking.
It is preferable.

  In the method for producing a dendronized polymer electrolyte of the present invention, specific examples and actions of a polymer compound having an aromatic group-containing structure, specific examples and actions of a linking group B, specific examples and actions of a branched structural unit C, and ions at the terminal Specific Examples and Actions of Ion Conducting Unit D Having Conductive Groups, Specific Examples and Actions of Hydrophobic Group E, Specific Examples and Actions of Hydrophilic Group F, and Ion Conductive Substances Added to Dendronized Polymer Electrolytes as Optional Components Specific examples and actions of the water-retaining substance are as described above.

  3rdly, this invention is a solid polymer electrolyte membrane containing 1 or more types of said dendronized polymer electrolyte. The solid polymer electrolyte membrane of the present invention can be used for various applications that require durability and high ion exchange capacity. Specifically, it is suitably used for fuel cells, water electrolysis, hydrohalic acid electrolysis, salt electrolysis, oxygen concentrators, humidity sensors, gas sensors and the like.

  The polymer electrolyte membrane of the present invention exhibits excellent ion conductivity both in a low humidified state and a high humidified state. The film forming method is not limited. The dendronized polymer electrolyte powder of the present invention can be mixed with an appropriate binder to form a film. The dendronized polymer electrolyte of the present invention is not a fluororesin but a hydrocarbon resin and does not have a three-dimensional structure, and can therefore be dissolved in an appropriate solvent. As a film forming method, a general method such as a casting method in which a solution is cast on a flat plate, a method in which a solution is applied on a flat plate by a die coater, a comma, etc., or a method in which a molten polymer material is stretched can be adopted. .

  Fourth, the present invention is a polymer electrolyte fuel cell electrode using one or more of the above dendronized polymer electrolytes.

  Fifth, the present invention is an invention of a solid polymer fuel cell, comprising a solid polymer electrolyte membrane (a), a conductive carrier carrying a catalyst metal, and a proton exchange material joined to the electrolyte membrane. The polymer solid electrolyte membrane and / or the proton exchange in a polymer electrolyte fuel cell having a membrane / electrode assembly (MEA) composed of a gas diffusion electrode (b) having an electrode catalyst as a main constituent material The material is the above dendronized polymer electrolyte or the above solid polymer electrolyte membrane.

  By using the polymer solid electrolyte and / or polymer solid electrolyte membrane of the present invention for a fuel cell, a fuel cell excellent in durability and ion conductivity can be obtained.

  In contrast to the conventional perfluorosulfonic acid polymer electrolyte membrane, the dendronized polymer electrolyte of the present invention is hydrocarbon-based. In addition, it has excellent heat resistance and strength, has a high number of ion conductive groups, has a high acid density, improves ion conductivity, expresses the mobility of ion conductive groups and the bulkiness of side chains, and increases the free volume of molecules, Furthermore, it has the outstanding property of ensuring an ion conduction path by making an ion conductive substance and / or a water retention substance exist in the space | gap in a molecule | numerator. As a result, the dendronized polymer electrolyte of the present invention has excellent ion conductivity both in a low humidified state and in a highly humidified state, and it becomes possible to improve the control performance of the fuel cell system and simplify the system.

  FIG. 1 shows a schematic diagram of the dendronized polymer electrolyte of the present invention. In the schematic diagram of FIG. 1, although it is planar, it goes without saying that the actual dendronized polymer electrolyte is three-dimensional.

  By the main chain composed of the repeating units A and A ′, basic physical properties of the dendronized polymer electrolyte such as heat resistance, mechanical strength and flexibility are exhibited. The linking group B may not be present, but the presence of the linking group B increases the mobility of the side chain in cooperation with the branched structural unit C while ensuring the heat resistance of the main chain. The linking group B may be contained not only between A ′ and C, but also between C and D, in the structure of C, or in the structure of D.

  The branched structural unit C having two or more branch points may not be present in all side chains in the molecule, but is present in at least a part. The branched structural unit C results in a dendronized polymer structure. By adding an ion conductive group to the branched side chain end, the acid density is increased to improve the ionic conductivity. Increase the free volume of the molecule by expressing the bulkiness of the chain.

  The ion conductive unit D having an ion conductive group at the terminal may not be present in all side chains in the molecule, but is present in at least a part. The ion conductivity as an electrolyte is exhibited by the ion conduction unit D.

  Further, the hydrophobic group E substituted with the repeating unit A constituting the main chain is an optional substituent, and may not be present at all in the repeating unit A in the molecule, or may be partially substituted. Similarly, the hydrophilic group F substituted with the repeating unit A ′ constituting the main chain is an optional substituent and may not be present at all in the repeating unit A ′ in the molecule, and is partially substituted. Also good.

  Furthermore, dendronized polymer electrolyte as an optional component in which an ion-conducting substance and / or a water-retaining substance are present in the gap G between the main chain and the side chain and the gap G ′ between the side chains of the molecule of the dendronized polymer electrolyte. The ion conductive path is more strongly formed by the ion conductive material and / or the water retention material added to.

(Example: Synthesis of dendronized polymer electrolyte)
The present invention will be described in more detail with reference to the following examples.
A sulfonated PDHN-G1 having 2,6-polydividoxynaphthalene (hereinafter referred to as PDHN) as a main chain structure and 3,5-dibenzyloxybenzyl alcohol (hereinafter referred to as G1-OH) as a side chain structure is shown in FIG. It was synthesized according to the scheme shown below.

[Synthesis of PDHN]
In a 20 mL eggplant flask, 0.046 g of Tokyo Chemical Industry's tetramethyldiamine copper chloride hydrochloride (Cu (OH) Cl.TMEDA (hereinafter, CuTMEDA)) was added to 6 mL of Tokyo Chemical Industry's dimethoxyethanol (distilled, hereinafter DME). After stirring for 30 minutes at room temperature and normal pressure to prepare a blue solution, add 0.32 g of Tokyo Chemical Industry Co., Ltd. 2,6-dihydroquinaphthalene (DHN) to the same solution and stir for 4 hours to obtain a green gel polymer. This was reprecipitated with hydrochloric acid 1 mol / L solution: MeOH 99% solution = 80: 20 (volume ratio) 200 mL solution, filtered under reduced pressure, and vacuum dried at 80 ° C. for 24 hr to obtain 0.318 g of black powder. (Yield ˜99%) This powder was redissolved in 10 mL of DME and vacuum dried at 110 ° C. to give a green fibrous polymer (Mn = 28,000). ) Was obtained.

[Synthesis of PDHN-G1]
Then, for the synthesis of the Kanto Chemical 3,5-benzyloxybenzyl alcohol _{G1-Cl ((C 6 H} 5 CH 2 O) C 6 H 3 CH 2 Cl), Tokyo Chemical Industry in a nitrogen-substituted atmosphere After dissolving 4.023 g of G1-OH in 10 mL of anhydrous N-methyl-2-pyrrolidone (hereinafter referred to as NMP), 1.01 mL of thionyl chloride manufactured by Wako Pure Chemical Industries, Ltd. was added and stirred for 1 hr, and then 100 mL of pure water. The mixture was reprecipitated in 1 hr and dried at 60 ° C. for 24 hr to obtain 4.014 g of pale yellowish white powder G1-Cl.

  Next, 0.318 g of PDHN black powder is placed in a two-necked flask (A) together with 2.484 g of potassium carbonate manufactured by Wako Pure Chemical Industries, and after nitrogen substitution, dissolved in 6 mL of anhydrous NMP manufactured by Tokyo Chemical Industry at 100 ° C. over 1 hr. It was. Thereafter, 1.494 g of G1-Cl obtained above was dissolved in 3 mL of anhydrous NMP in a two-necked flask (B) at 60 ° C. in a nitrogen atmosphere, transferred to (A) with a dried syringe, and stirred for 12 hr. Then, reprecipitation was performed in 100 mL acetone, followed by vacuum drying at 80 ° C. for 24 hours to obtain brown powder PDHN-G1. As shown in FIG. 3, the side chain protection rate determined from the peak ratio by 1H-NMR is about 85%, and the OH group spectrum (8-9 ppm) is small. It is thought that G1-Cl was added.

[Synthesis of Sulfonated PDHN-G1]
Next, a sulfonic acid group was added to the thus obtained PDHN-G1 with trimethylsilyl trifluoromethanesulfonic acid (hereinafter TMSTFMS). Specifically, 0.158 g (0.2 mmol) of fully dried PDHN-G1 was placed in a sufficiently dried two-necked flask (C), and after substitution with a nitrogen atmosphere, anhydrous dichloroethane (CH ₂ Cl ₂ ) manufactured by Tokyo Chemical Industry Co., Ltd. Dissolved in 2 mL. Next, after the sufficiently dried two-necked flask (D) was purged with nitrogen, 1 mL of dichloroethane was added, and 3 mL of TMSTFMS 25 mol / L chlorosulfuric acid manufactured by Aldrich was added to (D) to prepare a TMSTFMS solution. The solution was added dropwise to (C) under normal pressure of 10 ° C., and the precipitated black powder was reprecipitated twice in Hexane and simply dried with a desiccator to obtain 0.132 g of a dry black powder. As a result of performing NMR measurement of this, since all the peaks were shifted, it is considered that sulfonic acid was added to PDHN-G1. When this IEC measurement was performed, a sulfonic acid group equivalent EW = 500 was obtained.

  The dendronized polymer electrolyte of the present invention is a hydrocarbon-based polymer electrolyte and has a property of binding firmly to specific ions or selectively permeating cations or anions. It can be formed into a fiber or film. The dendronized polymer electrolyte membrane of the present invention can be widely used in fuel cells, water electrolysis, hydrohalic acid electrolysis, salt electrolysis, oxygen concentrators, humidity sensors, gas sensors and the like.

  The dendronized polymer electrolyte of the present invention improves the mobility of the ion conductive group and reduces the distance between the conductive groups, so that the conductivity can be maintained even under low humidification conditions, thereby simplifying the fuel cell system and improving the controllability. It becomes possible.

The schematic diagram of the dendronized polymer electrolyte of this invention. A synthesis scheme of sulfonated PDHN-G1 having 2,6-polydividroxynaphthalene (PDHN) as a main chain structure and 3,5-dibenzyloxybenzyl alcohol (G1-OH) as a side chain structure. 1H-NMR chart of sulfonated PDHN-G1 having 2,6-polydividroxynaphthalene (PDHN) as the main chain structure and 3,5-dibenzyloxybenzyl alcohol (G1-OH) as the side chain structure.

Claims (19)

A dendronized polymer electrolyte comprising a main chain having an aromatic group-containing structure represented by the following general formula (1) and a side chain having an ion conductive group as a terminal group.

(In the formula, A and A ′ are each independently an aromatic repeating unit, m = 5 to 10,000, n = 0 to 10,000, B is a linking group, b = 0 to 5, and C is 2 or more. Branch units having the following branch points: c = 0 to 5, D is an ion conductive unit having an ion conductive group at the terminal, d = 1 to 3, E is a hydrophobic group, e = 0 to 3, F is a hydrophilic group, and f = 0 to 3. The linking group B is not only between A ′ and C, but also between C and D, in the structure of C, or in the structure of D. It may be contained in   2. The ion-conductive substance and / or the water-retaining substance is present in a gap between the main chain and the side chain and / or between the side chains of the dendronized polymer electrolyte molecule. Of dendronized polymer electrolyte.   A, A ′ is polyphenylene, naphthalene, aromatic polyether, aromatic polythioether, aromatic polysulfone, aromatic polyethersulfone, aromatic linked with an alkylene group, aromatic polyamide, aromatic polyester, aromatic polyimide , Aromatic polyetherimide, aromatic polyamideimide, aromatic polyketone, aromatic polyetheretherketone, aromatic polyhydrazide, aromatic polyimine, polyoxadiazole, polybenzoxazole, polybenzimidazole, alkyl substituted compounds thereof The dendronized polymer electrolyte according to claim 1 or 2, wherein the dendronized polymer electrolyte is one or more selected from the group of these hydroxyl group-substituted compounds. B represents an ether group, a carbonyl group, a thioether group, a sulfone group, an amide group, a bissulfonimide group (—SO ₂ NHSO ₂ —), a sulfoncarbonimide group (—SO ₂ NHCO—), a biscarbonimide group (—CONHCO). The dendronized polymer electrolyte according to any one of claims 1 to 3, which is at least one selected from the group of-) and alkylene groups. The dendronized according to any one of claims 1 to 4, wherein C is at least one selected from the group represented by the following general formula, or at least one selected from these repeating structures. Polymer electrolyte.

D is a compound having one or more ion-conducting groups selected from the group represented by the following general formula (Rf is a structure having at least part of a fluorine atom, Ar is at least part of an aromatic ring; The dendronized polymer electrolyte according to any one of claims 1 to 5, wherein the dendronized polymer electrolyte is a structure having a structure.

  The dendronized polymer electrolyte according to any one of claims 1 to 6, wherein E is at least one selected from an alkyl group and a phenyl group.   8. The dendronized polymer electrolyte according to claim 1, wherein F is at least one selected from a hydroxy group, a carboxy group, an amino group, a carbonyl group, and a thiol group. Using a side chain of a polymer compound having an aromatic group-containing structure as a reaction point, a branched structural unit having two or more branch points is reacted with or without a linking group, and then the branch group is ionized as a terminal group. A reaction comprising reacting an ion-conducting group having a conductive group, or synthesizing a side chain having a branched structure in advance and reacting the side chain with a main chain having an aromatic group-containing structure, A method for producing a dendronized polymer electrolyte represented by the following general formula (1), comprising a main chain having a group-containing structure and a side chain having an ion conductive group at the terminal group.

(In the formula, A and A ′ are each independently an aromatic repeating unit, m = 5 to 10,000, n = 0 to 10,000, B is a linking group, b = 0 to 5, and C is 2 or more. Branch units having the following branch points: c = 0 to 5, D is an ion conductive unit having an ion conductive group at the terminal, d = 1 to 3, E is a hydrophobic group, e = 0 to 3, F is a hydrophilic group, and f = 0 to 3. The linking group B is not only between A ′ and C, but also between C and D, in the structure of C, or in the structure of D. It may be contained in   An ion conductive material and / or a water retention material is added to the dendronized polymer electrolyte molecule between the main chain and the side chain and / or between the side chains. The method for producing a dendronized polymer electrolyte according to claim 9, wherein:   The polymer compound having the aromatic group-containing structure is polyphenylene, naphthalene, aromatic polyether, aromatic polythioether, aromatic polysulfone, aromatic polyethersulfone, aromatic linked with an alkylene group, aromatic polyamide, Aromatic polyester, aromatic polyimide, aromatic polyetherimide, aromatic polyamideimide, aromatic polyketone, aromatic polyetheretherketone, aromatic polyhydrazide, aromatic polyimine, polyoxadiazole, polybenzoxazole, polybenz The production of a dendronized polymer electrolyte according to claim 9 or 10, which is at least one selected from the group consisting of imidazole, polysilsesquioxetane and derivatives, alkyl-substituted compounds thereof, and hydroxyl-substituted compounds thereof. Method. B represents an ether group, a carbonyl group, a thioether group, a sulfone group, an amide group, a bissulfonimide group (—SO ₂ NHSO ₂ —), a sulfoncarbonimide group (—SO ₂ NHCO—), a biscarbonimide group (—CONHCO). The method for producing a dendronized polymer electrolyte according to any one of claims 9 to 11, which is at least one selected from the group of-) and an alkylene group. The dendronized according to any one of claims 9 to 12, wherein C is one or more selected from the group represented by the following general formula, or one or more selected from the repeating structure thereof. A method for producing a polymer electrolyte.

D is a compound having one or more ion-conducting groups selected from the group represented by the following general formula (Rf is a structure having at least part of a fluorine atom, Ar is at least part of an aromatic ring; The process for producing a dendronized polymer electrolyte according to any one of claims 9 to 13, wherein

  The method for producing a dendronized polymer electrolyte according to any one of claims 9 to 14, wherein E is at least one selected from an alkyl group and a phenyl group.   The method for producing a dendronized polymer electrolyte according to any one of claims 9 to 15, wherein F is at least one selected from a hydroxy group, a carboxy group, an amino group, a carbonyl group, and a thiol group.   A solid polymer electrolyte membrane comprising at least one dendronized polymer electrolyte according to any one of claims 1 to 8.   An electrode for a polymer electrolyte fuel cell using one or more of the dendronized polymer electrolytes according to any one of claims 1 to 8.   A solid polymer electrolyte membrane (a), a gas diffusion electrode (b) mainly composed of an electrocatalyst carrying a catalytic metal and an electrocatalyst made of a proton exchange material, joined to the electrolyte membrane. A polymer electrolyte fuel cell having a membrane / electrode assembly (MEA), wherein the polymer solid electrolyte membrane and / or the proton exchange material is a dendronized polymer electrolyte according to any one of claims 1 to 8, or Item 18. A polymer electrolyte fuel cell, which is the polymer electrolyte membrane according to Item 17.

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