JP2015228292A - Solid polymer electrolyte membrane, membrane-electrode assembly, fuel battery, water electrolysis cell and water electrolysis device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solid polymer electrolyte membrane which enables the suppression of the precipitation of platinum in an electrolyte membrane.SOLUTION: A solid polymer electrolyte membrane comprises: electrolyte membranes (A) each including a polymer having an ion-exchange group; and a non-electrolyte layer having a polymer including substantially no sulfonic group. The non-electrolyte layer is composed of a layer which substantially not include a polymer having a functional group of which pKa is 3 or less, and has a thickness of 5 μm or less. The number of the electrolyte membranes (A) is two or more. At least one of the electrolyte membranes (A) is used in a folded form.

Description

  The present invention relates to a solid polymer electrolyte membrane, a membrane-electrode assembly, a fuel cell, a water electrolysis cell, and a water electrolysis apparatus.

  Fuel cells are power generators that directly extract electricity by electrochemically reacting hydrogen gas, methanol, and oxygen gas. They attract attention as pollution-free power generators that can directly convert chemical energy into electrical energy with high efficiency. ing.

  Such a fuel cell is usually composed of a pair of electrode membranes (anode electrode and cathode electrode) carrying a catalyst and one proton-conducting solid polymer electrolyte membrane sandwiched between the electrode membranes. Hydrogen ions and electrons are generated at the anode electrode, and the hydrogen ions pass through the solid polymer electrolyte membrane and react with oxygen at the cathode electrode to generate water.

  The solid polymer electrolyte membrane used here is required to have sufficient proton conductivity and suppression of permeation so that the supplied gas or fuel such as methanol does not directly react. In order to obtain a fuel cell exhibiting stable performance, it is required that the properties required for these solid polymer electrolyte membranes can be exhibited over a long period of time.

  Conventionally, various electrolyte membranes such as Nafion (registered trademark, manufactured by DuPont) are known as the solid polymer electrolyte membrane. In the fuel cell having the above-described configuration, these electrolyte membranes are fuels. When the battery is operated for a long time, it does not show sufficient durability, so it is not easy to obtain a fuel cell that exhibits stable properties over a long period of time.

  Here, Patent Documents 1 and 2 disclose a polymer electrolyte laminate film composed of a laminate of two or more films containing a polymer having an ion exchange group, as a polymer electrolyte membrane having high durability. .

JP 2006-155924 A JP 2006-128095 A

  In general, a catalyst layer is provided on an electrode of a fuel cell, and platinum is used as a catalyst contained in the catalyst layer. This platinum is important because it promotes the chemical reaction that is the source of the extracted electrical energy. On the other hand, during the operation of the battery, a part of the platinum in the catalyst layer is deposited in the electrolyte membrane. It is believed that platinum causes deterioration of the electrolyte membrane, which is a factor that reduces the long-term stability of the fuel cell.

  In addition, an electrode catalyst layer is provided in a water electrolysis cell used in a water electrolysis device that generates hydrogen and oxygen by electrolysis of water, and platinum is used for all or part of the electrode catalyst layer. Even in a water electrolysis apparatus, as in the case of a fuel cell, a part of platinum in an electrode catalyst layer is deposited in the electrolyte membrane during water electrolysis, and the deposited platinum causes deterioration of the electrolyte membrane, thereby causing water electrolysis. It is believed that this is a factor that reduces the long-term stability of the device.

Therefore, in order to improve the long-term stability of the fuel cell and the water electrolysis apparatus, it is desired to suppress the precipitation of platinum inside the electrolyte membrane.
However, in the polymer electrolyte membranes described in Patent Documents 1 and 2, platinum deposition inside the electrolyte membrane could not be suppressed.

  This invention is made | formed in view of the said subject, and it aims at providing the solid polymer electrolyte membrane which can suppress precipitation of platinum inside an electrolyte membrane.

Under such circumstances, as a result of intensive studies to solve the above problems, the present inventors have found that the above object can be achieved by a solid polymer electrolyte membrane having the following constitution, and the present invention has been achieved. It came to be completed.
A configuration example of the present invention is as follows.

  [1] A solid polymer electrolyte membrane comprising an electrolyte membrane (A) containing a polymer having ion exchange groups and a non-electrolyte layer having a polymer substantially free of sulfonic acid groups.

[2] The solid polymer electrolyte membrane according to [1], wherein the non-electrolyte layer is a layer substantially free of a polymer having a functional group having a pKa of 3 or less.
[3] The solid polymer electrolyte membrane according to [1] or [2], wherein the non-electrolyte layer has a thickness of 5 μm or less.

  [4] The solid polymer electrolyte membrane according to any one of [1] to [3], having two or more electrolyte membranes (A).

  [5] The solid polymer electrolyte membrane according to any one of [1] to [4], which includes a structure formed by bending the electrolyte membrane (A).

  [6] The solid polymer according to any one of [1] to [5], wherein the solid polymer electrolyte membrane is an electrolyte membrane used between a cathode and an anode, and the non-electrolyte layer is not in contact with the anode. Electrolyte membrane.

[7] A membrane-electrode assembly in which a gas diffusion layer, a catalyst layer, the solid polymer electrolyte membrane according to any one of [1] to [6], a catalyst layer, and a gas diffusion layer are laminated in this order.
[8] A fuel cell having the membrane-electrode assembly according to [7].

[9] A water electrolysis cell comprising a laminate in which the catalyst layer, the solid polymer electrolyte membrane according to any one of [1] to [6], and the catalyst layer are laminated in this order.
[10] A water electrolysis apparatus having the water electrolysis cell according to [9].

  According to the present invention, it is possible to obtain a solid polymer electrolyte membrane that is excellent in durability, has sufficient proton conductivity, and suppresses permeation of fuel and oxygen, etc., and can suppress the precipitation of platinum inside the electrolyte membrane. .

FIG. 1 is a schematic diagram showing an example of a membrane-electrode assembly including a solid polymer electrolyte membrane of the present invention having two or more electrolyte membranes. FIG. 2 is a schematic diagram showing an example of the solid polymer electrolyte membrane of the present invention including a structure formed by bending the electrolyte membrane.

≪Solid polymer electrolyte membrane≫
The solid polymer electrolyte membrane of the present invention includes an electrolyte membrane (A) containing a polymer having ion exchange groups and a non-electrolyte layer having a polymer substantially free of sulfonic acid groups.
Such a solid polymer electrolyte membrane of the present invention is excellent in durability, has sufficient proton conductivity and permeation suppression properties such as fuel and oxygen, and can suppress precipitation of platinum inside the electrolyte membrane. .

  The solid polymer electrolyte membrane of the present invention is not particularly limited as long as it has an electrolyte membrane (A) and a non-electrolyte layer, and conventionally known membranes (layers) exist in addition to these membranes (layers). However, it is preferable that the solid polymer electrolyte membrane is substantially composed only of the electrolyte membrane (A) and the non-electrolyte layer from the standpoint that the effects of the present invention can be exhibited more effectively.

Conventionally, in a fuel cell, since hydrogen ions generated at the anode electrode react at the cathode electrode through the electrolyte membrane, it is desirable to use a solid polymer electrolyte membrane exhibiting high proton conductivity from the viewpoint of proton conductivity. Has been considered.
However, although the solid polymer electrolyte membrane of the present invention has a non-electrolyte layer, it has sufficient proton conductivity, and can further suppress the precipitation of platinum inside the electrolyte membrane.

  According to the solid polymer electrolyte membrane of the present invention, the reason why such an effect is obtained is not clear, but in the non-electrolyte layer, large ions such as platinum pass between the polymers constituting the non-electrolyte layer. However, it is considered that small ions such as protons can pass between the macromolecules. That is, it is considered that the solid polymer electrolyte membrane of the present invention has the above-mentioned effect because the ion size to be passed can be selected and the passage of large ions such as platinum can be inhibited.

The solid polymer electrolyte membrane of the present invention is a fuel cell produced as described in the following examples, and the solid polymer electrolyte membrane by the potential cycle when the battery is operated as described in the following examples The amount of platinum deposited is preferably 5 μg / cm ² or less, more preferably 3 μg / cm ² or less.

Further, using the solid polymer electrolyte membrane of the present invention, a fuel cell was prepared as described in the following examples, and the solid polymer electrolyte was produced by a potential cycle when the battery was operated as described in the following examples. The amount of platinum deposited inside the membrane (μg / cm ² ) is one electrolyte membrane made of the same polymer as the polymer having an ion exchange group contained in the electrolyte membrane (A) constituting the solid polymer electrolyte membrane. (The electrolyte membrane is approximately the same thickness as the solid polymer electrolyte membrane) and is 0.8 times or less the amount of platinum deposited in the electrolyte membrane by the potential cycle measured in the same manner. Is preferable, and it is more preferable that it is 0.6 times or less.
In addition, when using the solid polymer electrolyte membrane which has 2 or more types of different electrolyte membranes (A) as a solid polymer electrolyte membrane of this invention, one electrolyte membrane compared with the solid polymer electrolyte membrane of this invention is The electrolyte membrane with the least amount of platinum deposition measured by the same method as described above.

  When the amount of platinum deposited inside the solid polymer electrolyte membrane is within the above range, a solid polymer electrolyte membrane having excellent durability and suppressing a decrease in molecular weight over time can be obtained, and power generation / water electrolysis performance and long-term stability can be obtained. This is preferable because a fuel cell and a water electrolysis device having excellent property balance can be obtained.

  A solid polymer electrolyte membrane in which the amount of platinum deposited inside the electrolyte membrane is in the above range can be produced, for example, by the following method.

  The thickness of the solid polymer electrolyte membrane of the present invention may be the same as that of a solid polymer electrolyte membrane usually used for fuel cells and water electrolysis cells, but is preferably 5 to 200 μm, more preferably 10 to 150 μm. It is.

<Method for producing solid polymer electrolyte membrane, etc.>
The solid polymer electrolyte membrane of the present invention is not particularly limited as long as it has an electrolyte membrane (A) and a non-electrolyte layer, and may have a plurality of electrolyte membranes (A) and a plurality of non-electrolyte layers. From the viewpoint of proton conductivity, mechanical strength, etc., a solid polymer electrolyte membrane comprising one or two electrolyte membranes (A) and one non-electrolyte layer is preferable.
When the solid polymer electrolyte membrane of the present invention includes a plurality of electrolyte membranes (A) and a plurality of non-electrolyte layers, these electrolyte membranes (A) and non-electrolyte layers are all the same membranes and layers, respectively. Alternatively, different types of films and layers may be used.

The solid polymer electrolyte membrane of the present invention may include a structure formed by bending the electrolyte membrane (A).
The structure may be a structure in which one electrolyte membrane (A) is bent, or may be a structure in which two or more electrolyte membranes (A) are stacked and bent. Alternatively, it may be a structure in which a laminate of a plurality of electrolyte membranes (A) and a non-electrolyte layer is folded, or these structures and other electrolyte membranes (folded or unfolded) or A structure including a non-electrolyte layer may be used.

The method for producing the solid polymer electrolyte membrane of the present invention is not particularly limited.
A method of forming a non-electrolyte layer on the electrolyte membrane (A) using the non-electrolyte layer-forming composition;
A method of simply superimposing a pre-formed electrolyte membrane (A) and a non-electrolyte layer, or laminating by a conventionally known method,
The method of coextruding the composition for electrolyte membrane (A) formation and the composition for nonelectrolyte layer formation is mentioned.

The method for producing the solid polymer electrolyte membrane of the present invention having two or more electrolyte membranes (A) is not particularly limited. For example, a non-electrolyte layer and two or more electrolyte membranes (A) are used.
(I) simply superimposing,
(Ii) pasting together under heating, or
(Iii) crosslinking under heating;
Can be manufactured.

The method for producing the solid polymer electrolyte membrane of the present invention containing the structure is not particularly limited.
The electrolyte membrane (A) and the non-electrolyte layer are simply overlapped or laminated by a conventionally known method, and (i-1) simply folding the laminate,
(Ii-1) bending, pasting together under heating, or
(Iii-1) bending, crosslinking under heating,
Can be manufactured with
And (i-2) simply bending the electrolyte membrane (A),
(Ii-2) bending, pasting together under heating, or
(Iii-2) bending and crosslinking with heating,
It is possible to manufacture by laminating the structure obtained in (1) and the non-electrolyte layer, and also by disposing the non-electrolyte layer between the electrolyte membranes of the structure obtained in (i-2). be able to.

Since the solid polymer electrolyte membrane obtained by the method of (i), (i-1) or (i-2) substantially does not contain impurities such as an adhesive, it is used for fuel cells and water electrolysis devices. It is preferable that the battery and water electrolysis characteristics are not deteriorated by the impurities during operation.
Further, according to the methods (i), (i-1), and (i-2), at least one of the electrolyte membranes (A) can be peeled or the space between the surfaces formed by bending can be reduced. A solid polymer electrolyte membrane that can be peeled can be obtained, and such a solid polymer electrolyte membrane is particularly well-balanced in terms of power generation / water electrolysis performance and durability. This is preferable because the precipitation of platinum at the substrate can be suppressed.

  In the method (i), the non-electrolyte layer and two or more electrolyte membranes (A) are simply overlapped, or the electrolyte membrane (A) is laminated with the non-electrolyte layer and the electrolyte membrane (A). It is preferable to simply superimpose them from the standpoints of obtaining a solid polymer electrolyte membrane that is excellent in durability, can reduce the molecular weight over time, and can suppress the precipitation of platinum inside the electrolyte membrane.

  The heating temperature in the method (ii), (ii-1) or (ii-2) is preferably a temperature lower than the glass transition temperature (Tg) of the polymer constituting the electrolyte membrane (A). The temperature is not particularly limited, but is preferably 10 to 90 ° C lower than Tg, more preferably 20 to 50 ° C lower than Tg. In the case of using an electrolyte membrane containing two or more types of polymers having different Tg as the solid polymer electrolyte membrane of the present invention, “the temperature below the Tg of the polymer constituting the electrolyte membrane” The temperature below the Tg of the polymer having the lowest Tg among all the electrolyte membranes used.

When the bonding is performed, a conventionally known adhesive may be used, and two or more electrolyte membranes are stacked and bonded by a known press technique such as a hot press, a roll press, or a vacuum press. It may be a thing.
In addition, although the said bonding may be performed after bending, you may perform it while bending.

  As the method (ii), preferably, the non-electrolyte layer and two or more electrolyte membranes (A) are simply overlapped, or the electrolyte membrane (A), the non-electrolyte layer, and the electrolyte membrane (A). The method of simply laminating the laminated body and laminating at a temperature lower than Tg of the polymer constituting the electrolyte membrane (A) is excellent in durability, and the molecular weight is decreased over time or in the electrolyte membrane. This is preferable from the viewpoint of obtaining a solid polymer electrolyte membrane capable of suppressing the deposition of platinum.

  In the solid polymer electrolyte membrane obtained by the method (ii), (ii-1) or (ii-2), the electrolyte membrane is not separated, and a membrane-electrode assembly or a water electrolysis cell described later is used. It is preferable in terms of workability at the time of manufacturing.

  The heating temperature in the method (iii), (iii-1) or (iii-2) is preferably a temperature lower than Tg of the polymer constituting the electrolyte membrane (A), Although not particularly limited, the temperature is preferably such that the crosslinking reaction proceeds, more preferably 10 to 90 ° C. lower than Tg, and particularly preferably 20 to 50 ° C. lower than Tg.

The method of (iii), (iii-1) or (iii-2) may be performed by using an electrolyte membrane or a non-electrolyte layer containing a crosslinking agent. When crosslinking is performed, a crosslinking agent is applied to the interface. It may be done by doing.
In the cross-linking, the non-electrolyte layer and the electrolyte membrane (A) may be overlapped while applying pressure by a known press technique such as hot press, roll press, vacuum press or the like.
In addition, although the said bridge | crosslinking may be performed after bending, you may perform it while bending.

  As the method (iii), preferably, the non-electrolyte layer and two or more electrolyte membranes (A) are simply overlaid or overlaid with a crosslinking agent interposed therebetween, or the electrolyte membrane (A ) And the non-electrolyte layer and the laminate of the electrolyte membrane (A) are simply overlaid or overlaid with a cross-linking agent, and then at a temperature lower than Tg of the polymer constituting the electrolyte membrane (A). The method of crosslinking is preferable from the viewpoints of obtaining a solid polymer electrolyte membrane that is excellent in durability, can reduce the molecular weight over time, and can suppress the precipitation of platinum inside the electrolyte membrane.

  In the solid polymer electrolyte membrane obtained by the method (iii), (iii-1) or (iii-2), the electrolyte membrane is not separated, and a membrane-electrode assembly and a water electrolysis cell described later are used. It is preferable in terms of workability at the time of manufacturing. Moreover, a solid polymer electrolyte membrane having high mechanical strength can be obtained by crosslinking. This is particularly effective when a thin electrolyte membrane is used.

  The crosslinking agent can be used without particular limitation as long as it can crosslink between electrolyte membranes or between an electrolyte membrane and a non-electrolyte layer. For example, a crosslinking agent having the following structure is preferable.

(Wherein R ¹ is hydrogen or an arbitrary organic group.)

  Specific examples of the cross-linking agent include RESITOP C357 (manufactured by Gunei Chemical Industry Co., Ltd.), DM-BI25X-F, 46DMOC, 46DMOIPP, 46DMOEP (trade name, manufactured by Asahi Organic Materials Co., Ltd.), DML. -MBPC, DML-MBOC, MDL-OCHP, DML-PC, DML-PCHP, DML-PTBP, DML-34X, DML-EP, DML-POP, DML-OC, dimethylol-Bis-C, dimethylol-BisOC-P , DML-BisOC-Z, DML-BisOCHP-Z, DML-PFP, DML-PSBP, DML-MB25, DML-MTrisPC, DML-Bis25X-34XL, DML-Bis25X-PCHP (trade name, Honshu Chemical Industry Co., Ltd.) ), "Nikarak" (registered trademark) MX-290 Trade name, manufactured by Sanwa Chemical Co., Ltd.), 2,6-dimethoxymethyl-4-t-butylphenol, 2,6-dimethoxymethyl-p-cresol, 2,6-diacetoxymethyl-p-cresol, TriML- P, TriML-35XL, TriML-TrisCR-HAP (trade name, manufactured by Honshu Chemical Industry Co., Ltd.), TM-BIP-A (trade name, manufactured by Asahi Organic Materials Co., Ltd.), TML-BP, TML-HQ , TML-pp-BPF, TML-BPA, TMOM-BP (trade name, manufactured by Honshu Chemical Industry Co., Ltd.), “Nicarac” MX-280, “Nicarac” MX-270 (trade name, Sanwa Chemical Co., Ltd.) Product), HML-TPPHBA, HML-TPHAP (trade name, manufactured by Honshu Chemical Industry Co., Ltd.), and the like.

  The solid polymer electrolyte membrane obtained by the method (i) to (iii), (i-1) to (iii-1) or (i-2) to (iii-2) is a single electrolyte membrane. (A) and sufficient proton conductivity as well as permeation suppression of fuel and oxygen, etc., as well as a solid polymer electrolyte membrane having a laminate in which two or more electrolyte membranes (A) are joined or fused. Furthermore, compared with the case of using one electrolyte membrane or a laminate of two or more electrolyte membranes bonded or fused, the power generation / water electrolysis performance can be achieved even when the same electrolyte membrane is used. In addition, it is excellent in balance in durability and tends to suppress the precipitation of platinum inside the solid polymer electrolyte membrane.

<Non-electrolyte layer>
The non-electrolyte layer is not particularly limited as long as it is a non-electrolyte layer having a polymer substantially free of a sulfonic acid group (hereinafter also referred to as “polymer (b)”).
When the solid polymer electrolyte membrane of the present invention has such a non-electrolyte layer, the precipitation of platinum inside the solid polymer electrolyte membrane can be suppressed.
The non-electrolyte layer may contain one type of polymer (b) or two or more types.
The non-electrolyte layer may contain additives other than the polymer (b).

When the solid polymer electrolyte membrane of the present invention is an electrolyte membrane used between a cathode and an anode, the non-electrolyte layer is a non-electrolyte layer from the viewpoint of power generation performance of a fuel cell and water electrolysis performance of a water electrolysis device. Is not in contact with the anode, that is, the non-electrolyte layer is preferably present on the cathode side or between the electrolyte membranes (A), more preferably on the cathode side.
“The non-electrolyte layer is not in contact with the anode” means that, for example, when the solid polymer electrolyte membrane of the present invention is used in contact with the catalyst layer, the non-electrolyte layer is not in contact with the anode-side catalyst layer. Means that.

The non-electrolyte layer is a layer that does not substantially contain a polymer having a functional group having a pKa of 3 or less from the viewpoint that the precipitation of platinum inside the solid polymer electrolyte membrane can be further suppressed. It is preferable.
Such a functional group having a pKa of 3 or less is preferably a group other than a group that has been used as an ion exchange group in a conventional electrolyte membrane such as a sulfonic acid group and a phosphonic acid group.

  Examples of the polymer (b) include polyacetal, polyethylene, polypropylene, acrylic resin, polystyrene, polyhydroxystyrene, polyhydroxyphenol, polyvinyl alcohol, polystyrene-graft-ethylenetetrafluoroethylene copolymer, polystyrene-graft- Aliphatic polymers such as polytetrafluoroethylene and aliphatic polycarbonate, polyester, polysulfone, polyphenylene ether, polyetherimide, aromatic polycarbonate, polyetheretherketone, polyetherketone, polyetherketoneketone, polyetherethersulfone, Polyethersulfone, polycarbonate, polyphenylene sulfide, aromatic polyamide, aromatic polyamideimide, aromatic polyimide, Li benzoxazole, polybenzothiazole, some or all of the backbone of the polybenzimidazole and the like and aromatic polymers having an aromatic ring are exemplified in. Among these, polystyrene, polyhydroxystyrene, polyhydroxyphenol, and polyvinyl alcohol are preferable.

  The weight average molecular weight (Mw) in terms of polystyrene by gel permeation chromatography (GPC) of the polymer (b) is preferably 100 to 1,000,000, more preferably 200 to 500,000, still more preferably 300 to 300,000. The weight average molecular weight / number average molecular weight (Mw / Mn) is preferably 1.2 to 10.0, more preferably 1.5 to 8.0, and still more preferably 2.0 to 5.0. . Specifically, the average molecular weight of the polymer (b) can be measured by the method described in the Examples below.

  The non-electrolyte layer includes, for example, a step of applying a mixture containing the polymer (b) and a solvent for dissolving the polymer (b) onto the electrolyte membrane (A) or the substrate by a known method. Can be manufactured. Specifically, after applying the mixture onto a substrate such as an electrolyte membrane (A), resin (eg, polyethylene terephthalate (PET)), metal, or glass, the applied composition is dried. Can be created.

  The solvent for dissolving the polymer (b) may be appropriately selected according to the polymer (b), and conventionally known solvents can be used.

  In the case of using an electrolyte membrane (A) or a fuel cell constituent material as a target to which the mixture is applied, and being laminated in contact with the solid polymer electrolyte membrane of the present invention, for example, the following catalyst layer (cathode) The obtained electrolyte membrane (A) may be used without being peeled from the base material, but when other base materials are used, it may be peeled off from the base material.

  The thickness of the non-electrolyte layer is preferably from the standpoint that platinum deposition inside the solid polymer electrolyte membrane can be suppressed, and a solid polymer electrolyte membrane having sufficient proton conductivity can be obtained. It is 5 μm or less, more preferably 3 μm or less, and even more preferably 2 μm or less.

<Electrolyte membrane (A)>
The electrolyte membrane (A) includes a polymer having an ion exchange group (hereinafter also referred to as “polymer (a)”). Such an electrolyte membrane (A) is not particularly limited, and may be one that has been conventionally used as a solid polymer electrolyte membrane.

  The electrolyte membrane (A) is produced, for example, by including a step of applying a composition containing the polymer (a) and a solvent for dissolving the polymer (a) onto a substrate by a known method. can do. Specifically, after the composition is applied on a resin (eg, polyethylene terephthalate (PET)), metal or glass substrate, the applied composition is dried and peeled off from the substrate. Can be created. In addition, as a base material, which is a constituent material of a fuel cell and is laminated in contact with the solid polymer electrolyte membrane of the present invention, for example, when using the following catalyst layer, the obtained electrolyte membrane (A) You may use without peeling from a base material.

  The electrolyte membrane (A) is an electrolyte membrane including a reinforcement layer obtained by impregnating or applying the composition to a reinforcement layer made of a porous material or a sheet-like fibrous substance. Alternatively, it may be an electrolyte membrane containing fibers, filler-like reinforcing materials, and the like.

  The electrolyte membrane (A) is a compound having a high platinum affinity (eg, a compound containing a sulfur atom), a metal-containing compound such as tin oxide or tin ion, and the like, as long as the effects of the present invention are not impaired. An additive such as at least one metal component selected from the group consisting of metal ions may be included.

  In addition to the polymer (a) and the solvent, the composition further includes inorganic acids such as sulfuric acid and phosphoric acid; phosphate glass; tungstic acid; phosphate hydrate; β-alumina proton-substituted product; Inorganic proton conductor particles such as proton-introduced oxide; organic acid containing carboxylic acid; organic acid containing sulfonic acid; organic acid containing phosphonic acid;

  Although the thickness of the said electrolyte membrane (A) should just be a thickness comparable as the electrolyte membrane normally used for a fuel cell or a water electrolysis apparatus, Preferably it is 3-200 micrometers, More preferably, it is 5-150 micrometers.

The Tg of the polymer (a) is such that the electrolyte membranes constituting the solid polymer electrolyte membrane are not fused together during operation of the fuel cell or water electrolysis device, and a fuel cell or water electrolysis device having a desired effect is obtained. From the point of being able to do, it is preferably 100 ° C. or higher, more preferably 120 ° C. or higher, particularly preferably 150 ° C. or higher. The upper limit of the Tg is not particularly limited, but may be, for example, 250 ° C.
By having the Tg of the polymer (a) in the above range, it is possible to obtain a solid polymer electrolyte membrane that is excellent in durability and capable of suppressing the temporal decrease in molecular weight and the precipitation of platinum inside the electrolyte membrane, Furthermore, a fuel cell and a water electrolysis device having excellent durability and the like can be obtained.

  When two or more kinds of different electrolyte membranes (A) are used as the solid polymer electrolyte membrane of the present invention, Tg of all the polymers (a) constituting the electrolyte membrane (A) to be used is 100 ° C. or more. It is preferable that When the polymer (a) has two or more glass transition temperatures, the Tg of the polymer (a) refers to the lower glass transition temperature.

  The weight average molecular weight (Mw) in terms of polystyrene by GPC of the polymer (a) is preferably 10,000 to 1,000,000, more preferably 20,000 to 800,000, still more preferably 50,000 to 300,000. Average molecular weight (Mn) becomes like this. Preferably it is 3000-1 million, More preferably, it is 6000-800,000, More preferably, it is 15000-300,000. Specifically, the average molecular weight of the polymer (a) can be measured by the method described in the Examples below.

  The ion exchange capacity of the polymer (a) is preferably 0.5 to 3.5 meq / g, more preferably 0.5 to 3.0 meq / g, still more preferably 0.8 to 2.8 meq / g. is there. An ion exchange capacity of 0.5 meq / g or more is preferable because a solid polymer electrolyte membrane having high proton conductivity and high power generation / water electrolysis performance can be obtained. On the other hand, it is preferably 3.5 meq / g or less because a solid polymer electrolyte membrane having sufficiently high water resistance can be obtained. Specifically, the ion exchange capacity of the polymer (a) can be measured by the method described in the Examples below.

The ion exchange capacity can be adjusted by changing the type of the structural unit contained in the polymer (a), its ratio, combination, and the like. Therefore, it can be adjusted by changing the charge amount ratio, type, etc. of the precursor (monomer / oligomer) that induces the structural unit during the polymerization.
In general, when the proportion of the structural unit containing an ion exchange group increases in the polymer (a), the ion exchange capacity of the obtained solid polymer electrolyte membrane increases and the proton conductivity increases, but the water resistance tends to decrease. On the other hand, when the proportion of the structural unit is decreased, the ion exchange capacity of the obtained solid polymer electrolyte membrane is decreased and the water resistance is increased, but the proton conductivity tends to be decreased.

  Although it does not restrict | limit especially as said ion exchange group, A sulfonic acid group, a phosphonic acid group, a carboxy group, a bissulfonyl imide group etc. are mentioned, A sulfonic acid group is preferable.

Examples of the polymer (a) include fats such as polyacetal, polyethylene, polypropylene, acrylic resin, polystyrene, polystyrene-graft-ethylenetetrafluoroethylene copolymer, polystyrene-graft-polytetrafluoroethylene, and aliphatic polycarbonate. Polymers in which a sulfonic acid group is introduced into an aromatic polymer, polyester, polysulfone, polyphenylene ether, polyetherimide, aromatic polycarbonate, polyether ether ketone, polyether ketone, polyether ketone ketone, polyether ether sulfone, poly Ether sulfone, polycarbonate, polyphenylene sulfide, aromatic polyamide, aromatic polyamideimide, aromatic polyimide, polybenzoxazole, polybenzothiazo Le, aromatic polymer polymer having sulfonate group introduced therein in having an aromatic ring in a part or the whole of the main chain such as polybenzimidazole and the like.
Moreover, the polymer which changed the group introduce | transduced into these polymers into ion exchange groups, such as a phosphonic acid group from a sulfonic acid group, the polymer in which these groups coexist, etc. are mentioned.

  A known polymer can be used as the polymer, and is not particularly limited. For example, Nafion (registered trademark, manufactured by DuPont), Aciplex (registered trademark, manufactured by Asahi Kasei Kogyo Co., Ltd.), Flemion (A registered trademark, manufactured by Asahi Glass Co., Ltd.), a fluorinated carbon-based high molecular polymer having a sulfonic acid group commercially available; polyaromatic hydrocarbon-based, polyetheretherketone-based, polyphenylene sulfide-based, A high molecular polymer having an aromatic ring such as a polyimide-based or polybenzazole-based main chain skeleton and a sulfonic acid group can be used. Among them, International Publication Nos. 2013/018677, 2012-0667216, 2010-238374, 2010-174179, 2010-135282, 2004-137444, and the like. The polymers described in JP 2004-345997 A, JP 2004-346163 A, and the like are preferable, and the following polymer (1) is more preferable.

・ Polymer (1)
The polymer (1) is a polymer having a structural unit having a proton conductive group and a hydrophobic structural unit, and is a polymer or an oligomer.
In the present invention, the structural unit having a proton conductive group may be simply a proton conductive group, and examples of the proton conductive group include a sulfonic acid group, a phosphonic acid group, a carboxy group, and a bissulfonylimide group. And sulfonic acid groups are preferred.

  Specifically, the polymer (1) is a polymer comprising a hydrophilic segment (A1) serving as a structural unit having a proton conductive group and a hydrophobic segment (B1) serving as a hydrophobic structural unit. It is preferable. In this case, the polymer (1) may be a block polymer or a random polymer. However, the polymer (1) is more excellent in power generation, water electrolysis performance, and dimensional stability during a wet and dry cycle. In view of obtaining a film, a block copolymer of the hydrophilic segment (A1) and the hydrophobic segment (B1) is preferable.

・ Hydrophilic segment (A1)
The hydrophilic segment (A1) is not particularly limited as long as it has a proton conductive group and exhibits hydrophilicity. For example, the hydrophilic segment (A1) has an aromatic ring in the main chain and a proton conductive group such as a sulfonic acid group. From the point that an electrolyte membrane (A) having high continuity of the hydrophilic segment and high proton conductivity can be obtained (hereinafter referred to as the structural unit represented by the following formula (5)) A segment including “structural unit (5)” is preferable, and a segment including the structural unit (5) is more preferable.
The hydrophilic segment (A1) may consist of only one type of structural unit or may contain two or more types of structural units.

In the formula (5), Ar ¹¹ , Ar ¹² and Ar ¹³ are each independently a halogen atom, a nitrile group, a monovalent hydrocarbon group having 1 to 20 carbon atoms or a monovalent halogenated carbonization having 1 to 20 carbon atoms. An aromatic group having a benzene ring, a condensed aromatic ring or a nitrogen-containing heterocyclic ring, which may be substituted with a hydrogen group, and Y and Z are each independently a direct bond, -O-, -S-, -CO _{-, - SO 2 -, -} SO -, - (CH 2) u -, - (CF 2) u - (u is an integer of 1 to _{10.), - C (CH 3} ) 2 - or -C (CF ₃ ) ₂ — and R ¹⁷ is independently a direct bond, —O (CH ₂ ) _p —, —O (CF ₂ ) _p —, — (CH ₂ ) _p — or — (CF ₂ ) _p. -(P represents an integer of 1 to 12), and R ¹⁸ and R ¹⁹ each independently represent a hydrogen atom or a protecting group. However, at least one of all R ¹⁸ and R ¹⁹ contained in the structural unit (5) is a hydrogen atom.
x ¹ independently represents an integer of 0 to 6, x ² represents an integer of 1 to 7, a represents 0 or 1, and b represents an integer of 0 to 20.

The protecting group refers to an ion, atom or atomic group used for the purpose of temporarily protecting a reactive group (—SO ₃ — or —SO ₃ ⁻ ). Specific examples include an alkali metal atom, an aliphatic hydrocarbon group, an alicyclic group, an oxygen-containing heterocyclic group, and a nitrogen-containing cation.

  The hydrophilic segment (A1) includes, in addition to the structural unit (5) having a sulfonic acid group, as a structural unit having a proton conductive group other than a sulfonic acid group, for example, a structural unit having a phosphonic acid group, Aromatic structural units having a nitrogen-containing heterocyclic ring described in Kaikai 2011-089036 and International Publication No. 2007/010731 may be included.

・ Hydrophobic segment (B1)
The hydrophobic segment (B1) is not particularly limited as long as it is a hydrophobic segment.
The hydrophilic segment (B1) may be composed of only one type of structural unit or may include two or more types of structural units.

  The hydrophobic segment (B1) preferably includes a hydrophobic segment that has an aromatic ring in the main chain and does not contain a proton conductive group such as a sulfonic acid group, and is an electrolyte membrane that is more excellent in suppressing hot water swelling ( In view of obtaining A), a structural unit represented by the following formula (1) (hereinafter also referred to as “structural unit (1)”), a structural unit represented by the following formula (2) (hereinafter referred to as “structure”). Unit (2) ”) and at least one structural unit selected from the group consisting of structural units represented by the following formula (3 ′) (hereinafter also referred to as“ structural unit (3 ′) ”). A segment is preferable, and a segment composed of at least one structural unit selected from the group consisting of the structural unit (1) and the structural unit (2) is more preferable.

  When the polymer (1) contains any one of the structural units (1) to (3 ′), in particular, the structural unit (1) or (2), the hydrophobicity of the polymer is remarkably improved. . For this reason, it is possible to obtain an electrolyte membrane (A) having excellent hot water resistance while having proton conductivity similar to the conventional one. Moreover, when segment (B1) contains a nitrile group, an electrolyte membrane (A) with high toughness and mechanical strength can be produced.

・ Structural unit (1)
When the hydrophobic segment (B1) contains the structural unit (1), the segment (B1) includes the polymer (1) obtained by increasing the rigidity and increasing the aromatic ring density. The hot water resistance of the electrolyte membrane (A), radical resistance to peroxide, gas barrier properties, mechanical strength, dimensional stability, and the like can be improved.
The hydrophobic segment (B1) may include one type of structural unit (1), or may include two or more types of structural units (1).

In the formula (1), at least one substitutable carbon atom constituting the aromatic ring may be replaced with a nitrogen atom, and R ²¹ is independently a halogen atom, a hydroxy group, a nitro group, a nitrile group or R ²² —. E- (E is a direct bond, —O—, —S—, —CO—, —SO ₂ —, —CONH—, —COO—, —CF ₂ —, —CH ₂ —, —C (CF ₃ ) _2- or -C (CH ₃ ) _2- ; R ²² represents an alkyl group, a halogenated alkyl group, an alkenyl group, an aryl group, a halogenated aryl group or a nitrogen-containing heterocycle, and at least one of these groups one of the hydrogen atoms, further hydroxy group, a nitro group, may be substituted with at least one group selected from the group consisting of nitrile group, and R ²² -E-.) shows a plurality of R ²¹ is bonded To form a ring structure.
When R ²¹ is R ²² -E- and R ²² is further substituted with R ²² -E-, the plurality of E may be the same or different, and a plurality of R ²² (provided that The structure of the portion excluding the structural difference caused by the substitution may be the same or different. Similarly, in the present invention, when there are a plurality of groups represented by the same symbol in one formula, these groups may be the same or different. However, when several R <^22> is contained in one formula, it is preferable that the upper limit is five.
c ¹ and c ² independently represent an integer of 0 or 1 or more, d represents an integer of 1 or more, and e independently represents an integer of 0 to (2c ¹ + 2c ² +4).

・ Structural unit (2)
It is preferable that the hydrophobic segment (B1) contains the structural unit (2) because radical resistance to peroxides and the like is improved, and an electrolyte membrane (A) excellent in power generation / water electrolysis durability can be obtained.
Moreover, when the hydrophobic segment (B1) contains the structural unit (2), an appropriate flexibility (flexibility) can be imparted to the segment (B1), and the electrolyte membrane containing the resulting polymer The toughness of (A) can be improved.
The hydrophobic segment (B1) may include one type of structural unit (2), or may include two or more types of structural units (2).

In the formula (2), at least one substitutable carbon atom constituting the aromatic ring may be replaced with a nitrogen atom, and R ³¹ is independently a halogen atom, a hydroxy group, a nitro group, a nitrile group or R ²² —. E- (E and R ²² are each independently synonymous with E and R ²² in the formula (1)), and a plurality of R ³¹ may be bonded to form a ring structure.
f represents 0 or an integer of 1 or more, and g represents an integer of 0 to (2f + 4). However, the structural unit represented by Formula (2) is a structural unit other than the structural unit represented by Formula (1).

・ Structural unit (3 ')
When the hydrophobic segment (B1) contains the structural unit (3 ′), an appropriate flexibility (flexibility) can be imparted to the segment (B1), and an electrolyte membrane containing the resulting polymer ( The toughness of A) can be improved.
The hydrophobic segment (B1) may include one type of structural unit (3 ′) or may include two or more types of structural units (3 ′).

In formula (3 ′), A ′ and D ′ are each independently a direct bond, —O—, —S—, —CO—, —SO ₂ —, —SO—, —CONH—, —COO—, — (CF _{2) i} - _(i is an integer of 1 to _{10), - (CH 2) j} - (j is an integer of 1 to _{10), - CR '2 - (} R' is an aliphatic hydrocarbon Group, an aromatic hydrocarbon group or a halogenated hydrocarbon group.), A cyclohexylidene group or a fluorenylidene group, B ′ independently represents an oxygen atom or a sulfur atom, and R ^{1 to} R ¹⁶ each independently represent represent hydrogen atom, halogen atom, hydroxy group, nitro group, nitrile group or R ²² -E- (E and R ²² are independently the same as E and R ²² in the formula (1).) shows the , R ^{1 to} R ¹⁶ may combine to form a ring structure.
s and t each independently represent an integer of 0 to 4, and r represents 0 or an integer of 1 or more.

-Synthesis method of polymer (1) The polymer (1) can be synthesized by a conventionally known method and is not particularly limited. For example, the compound serving as the structural unit is reacted in the presence of a catalyst or a solvent. Then, if necessary, it can be synthesized by introducing a proton conductive group by a method such as conversion of a sulfonic acid ester group or the like to a sulfonic acid group, or sulfonation using a sulfonating agent.

≪Membrane-electrode assembly≫
The membrane-electrode assembly according to the present invention is a membrane-electrode assembly in which a gas diffusion layer, a catalyst layer, a solid polymer electrolyte membrane of the present invention, a catalyst layer, and a gas diffusion layer are laminated in this order. Specifically, a catalyst layer for a cathode electrode is provided on one surface of the solid polymer electrolyte membrane of the present invention, and a catalyst layer for an anode electrode is provided on the other surface. It is preferable that a gas diffusion layer is provided in contact with the opposite side of the catalyst layer for each electrode to the solid polymer electrolyte membrane.

  Examples of the membrane-electrode assembly including the solid polymer electrolyte membrane containing the non-electrolyte layer and the two electrolyte membranes (A) include a membrane-electrode assembly as shown in FIG. As described above, the solid polymer electrolyte membrane including the non-electrolyte layer and the two electrolyte membranes (A) is formed so that the widest surface of the non-electrolyte layer and the electrolyte membrane (A) overlaps. It is preferable that the membrane (layer) is laminated by the above method from the viewpoint of obtaining a fuel cell excellent in power generation performance and a water electrolysis device excellent in water electrolysis performance.

  2 is used instead of the solid polymer electrolyte membrane 17 of FIG. 1, the solid polymer electrolyte membrane 17 ′ of FIG. 2 is replaced with the solid polymer electrolyte membrane 17 ′ of FIG. Membrane-electrode assemblies containing in the orientation are preferred. That is, when the electrolyte membrane (A) is folded, the electrolyte membrane (A) is laminated so that the widest surface of the electrolyte membrane (A) faces and the interface of the electrolyte membrane that can be folded is laminated with the catalyst layer or the like. The electrolyte membrane (A) is preferably bent so as to be in a direction substantially perpendicular to the direction.

  The gas diffusion layer is not particularly limited and a known one can be used, and examples thereof include a porous substrate or a laminated structure of a porous substrate and a microporous layer. When the gas diffusion layer is composed of a laminated structure of a porous substrate and a microporous layer, the microporous layer is preferably in contact with the catalyst layer. The gas diffusion layer preferably contains a fluoropolymer in order to impart water repellency.

  Although the thickness of the said gas diffusion layer should just be the same thickness as the gas diffusion layer normally used for a fuel cell, Preferably it is 50-400 micrometers, More preferably, it is 100-300 micrometers.

The catalyst layer is not particularly limited, and a known layer can be used. For example, the catalyst layer includes a catalyst, an ion exchange resin electrolyte, and the like.
As the catalyst, a noble metal catalyst such as platinum, palladium, gold, ruthenium or iridium is preferably used. The noble metal catalyst may contain two or more elements such as an alloy or a mixture. As such a precious metal catalyst, a catalyst supported on high specific surface area carbon fine particles may be used.

  The ion exchange resin electrolyte functions as a binder component for binding the catalyst, and efficiently supplies ions generated by the reaction on the catalyst to the solid polymer electrolyte membrane at the anode electrode, and the solid polymer at the cathode electrode. A substance that efficiently supplies ions supplied from the electrolyte membrane to the catalyst is preferable.

The ion exchange resin electrolyte is preferably a polymer having a proton exchange group in order to improve proton conductivity in the catalyst layer.
Examples of proton exchange groups contained in such a polymer include, but are not particularly limited to, sulfonic acid groups, carboxylic acid groups, and phosphoric acid groups.
Further, a polymer having such a proton exchange group is also used without any particular limitation, but a polymer having a proton exchange group composed of a fluoroalkyl ether side chain and a fluoroalkyl main chain, and a sulfonic acid group can be used. An aromatic hydrocarbon polymer having the same is preferably used. Further, the polymer (a) exemplified in the column of the electrolyte membrane (A) may be used as an ion exchange resin electrolyte, and further, a polymer having a proton exchange group and containing a fluorine atom, such as ethylene or styrene. Other polymers obtained, copolymers or blends thereof may be used.

  As such an ion exchange resin electrolyte, a known one can be used without particular limitation, and may be, for example, Nafion.

  The catalyst layer may further contain an additive such as a carbon fiber or a resin having no ion exchange group, if necessary. This additive is preferably a component having high water repellency, and examples thereof include a fluorine-containing copolymer, a silane coupling agent, a silicone resin, a wax, and polyphosphazene. It is a coalescence.

  Although the thickness of the said catalyst layer should just be the same thickness as the catalyst layer normally used for a fuel cell or a water electrolysis apparatus, Preferably it is 1-100 micrometers, More preferably, it is 3-50 micrometers.

≪Fuel cell≫
The fuel cell according to the present invention has the membrane-electrode assembly. For this reason, the fuel cell according to the present invention is particularly excellent in durability, a decrease in power generation performance over time is suppressed, and stable power generation is possible over a long period of time.

  Specifically, the fuel cell according to the present invention includes at least one electricity generation unit including a separator, located on both outer sides of at least one membrane-electrode assembly; a fuel supply unit that supplies fuel to the electricity generation unit And an oxidant supply part for supplying an oxidant to the electricity generation part.

  As said separator, what is used for a normal fuel cell can be used. Specifically, a carbon type separator, a metal type separator, etc. are mentioned.

  Moreover, as a member which comprises a fuel cell, it is possible to use a well-known thing without a restriction | limiting in particular. The fuel cell of the present invention may be a single cell or a stack cell in which a plurality of single cells are connected in series. A known method can be used as the stacking method. Specifically, it may be flat stacking in which single cells are arranged in a plane, and a fuel or oxidant flow path is a stack in which single cells are stacked via separators formed on the back surface of the separator. Polar stacking may be used.

≪Water electrolysis cell≫
The water electrolysis cell according to the present invention includes a laminate in which the catalyst layer, the solid polymer electrolyte membrane of the present invention, and the catalyst layer are laminated in this order.
As the catalyst layer, a known layer can be used without particular limitation, and specifically, the same layer as the catalyst layer described in the membrane-electrode assembly can be used.

≪Water electrolysis equipment≫
The water electrolysis apparatus according to the present invention has the water electrolysis cell. For this reason, the water electrolysis apparatus according to the present invention is particularly excellent in durability, suppresses a decrease in performance over time, and enables stable electrolysis over a long period of time.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these Examples.

[Ion exchange capacity of polymer having sulfonic acid group]
The ion exchange capacity of the polymers obtained in the following synthesis examples was measured as follows.
The polymer obtained in the following synthesis example was immersed in deionized water to completely remove the acid remaining in the polymer, and then immersed in 2 mL of 2N saline per 1 mg of the polymer. A hydrochloric acid aqueous solution was prepared by ion exchange. This hydrochloric acid aqueous solution was neutralized with a standard aqueous solution of 0.001N sodium hydroxide using phenolphthalein as an indicator. The polymer after ion exchange was washed with deionized water, dried in vacuum at 110 ° C. for 2 hours, and the dry weight was measured. As shown in the following formula, an equivalent amount of sulfonic acid group (hereinafter referred to as “ion exchange capacity”) was determined from the titration amount of sodium hydroxide and the dry weight of the polymer.
Ion exchange capacity (meq / g) = titration amount of sodium hydroxide (mmol) / dry weight of polymer (g)

(Measurement of molecular weight)
The molecular weight of the compounds obtained in the following synthesis examples was measured using the following method (A) or (B) depending on the compound to be measured.

(A) A compound to be measured is dissolved in an N-methyl-2-pyrrolidone buffer solution (hereinafter referred to as “NMP buffer solution”), an NMP buffer solution is used as an eluent, and TOSOH HLC-8220 (manufactured by Tosoh Corporation) is used as an apparatus. The number average molecular weight (Mn) and weight average molecular weight (Mw) in terms of polystyrene were determined by gel permeation chromatography (GPC) using TSKgel α-M (manufactured by Tosoh Corporation) as a column.
The NMP buffer solution was prepared at a ratio of NMP (3 L) / phosphoric acid (3.3 mL) / lithium bromide (7.83 g).

  (B) A compound to be measured is dissolved in tetrahydrofuran (THF), THF is used as an eluent, TOSOH HLC-8220 (manufactured by Tosoh Corporation) is used as an apparatus, and TSKgel α-M (manufactured by Tosoh Corporation) is used as a column. Polystyrene-converted Mn and Mw were determined by the GPC used.

[Synthesis Example 1]
(1) Synthesis of hydrophobic unit 49.4 g of 2,6-dichlorobenzonitrile was added to a 1 L three-necked flask equipped with a stirrer, a thermometer, a condenser tube, a Dean-Stark tube and a three-way cock for introducing nitrogen. 0.29 mol), 2,2-bis (4-hydroxyphenyl) -1,1,1,3,3,3-hexafluoropropane 88.4 g (0.26 mol), and potassium carbonate 47.3 g ( 0.34 mol) was weighed out. After replacing the obtained flask with nitrogen, 346 mL of sulfolane and 173 mL of toluene were added to the flask and stirred. The flask was placed in an oil bath and heated to reflux at 150 ° C. When water produced by the reaction was azeotroped with toluene and reacted while being removed from the system with a Dean-Stark tube, almost no water was observed in about 3 hours. After removing most of the toluene while gradually raising the reaction temperature, the reaction was continued at 200 ° C. for 3 hours. Next, 12.3 g (0.072 mol) of 2,6-dichlorobenzonitrile was added, and the reaction was further continued for 5 hours. The resulting reaction solution was allowed to cool and then diluted by adding 100 mL of toluene. The precipitate of the inorganic compound produced as a by-product was removed by filtration, and the filtrate was put into 2 L of methanol. The precipitated product was collected by filtration, dried, and then dissolved in 250 mL of tetrahydrofuran. The obtained solution was poured into 2 L of methanol and reprecipitated to obtain 107 g of the target compound (precipitate).
The Mn in terms of polystyrene determined by GPC (solvent: THF) of the obtained target compound was 7,300. The obtained compound was an oligomer represented by the following structural formula.

(2) Synthesis of hydrophilic unit To a 3 L three-necked flask equipped with a stirrer and a condenser tube was added 233.0 g (2 mol) of chlorosulfonic acid, followed by 100.4 g (400 mmol) of 2,5-dichlorobenzophenone. ) Was added, and the resulting flask was placed in a 100 ° C. oil bath and allowed to react for 8 hours. After 8 hours, the reaction solution was slowly poured onto 1000 g of crushed ice and extracted with ethyl acetate. The organic layer was washed with brine and dried over magnesium sulfate, and then ethyl acetate was distilled off to obtain pale yellow crude crystals of 3- (2,5-dichlorobenzoyl) benzenesulfonic acid chloride. The crude crystals were not purified and used as they were in the next step.

  3,8.8 g (440 mmol) of 2,2-dimethyl-1-propanol (neopentyl alcohol) was added to 300 mL of pyridine and cooled to about 10 ° C. The crude crystals obtained above were gradually added thereto over about 30 minutes. After the total amount was added, the reaction was further stirred for 30 minutes. After the reaction, the reaction solution was poured into 1000 mL of hydrochloric acid water, and the precipitated solid was collected. The obtained solid was dissolved in ethyl acetate, washed successively with aqueous sodium bicarbonate solution and brine, dried over magnesium sulfate, and ethyl acetate was distilled off to obtain crude crystals. This was recrystallized with methanol to obtain white crystals of neopentyl 3- (2,5-dichlorobenzoyl) benzenesulfonate represented by the following structural formula.

(3) Synthesis of basic unit 240.2 g (2.50 mol) of fluorobenzene was placed in a 2 L three-necked flask equipped with a stirring blade, a thermometer and a nitrogen introduction tube, and cooled to 10 ° C. in an ice bath. 2,5-dichlorobenzoic acid chloride 134.6 g (0.50 mol) and aluminum chloride 86.7 g (0.65 mol) were gradually added so that the reaction temperature did not exceed 40 ° C. After the addition, the mixture was stirred at 40 ° C. for 8 hours. After confirming the disappearance of the raw material by thin layer chromatography, the stirred mixture was added dropwise to ice water and extracted with ethyl acetate. The obtained organic layer was neutralized with 5% aqueous sodium bicarbonate, washed with saturated brine, dried over magnesium sulfate, and the solvent was distilled off with an evaporator. This was recrystallized from methanol to obtain 130 g of intermediate 2,5-dichloro-4′-fluorobenzophenone in a yield of 97%.

  To a 2 L three-necked flask equipped with a stirrer, thermometer, condenser, Dean-Stark tube and nitrogen-introduced three-way cock, 130.5 g (0.49 mol) of 2,5-dichloro-4′-fluorobenzophenone was added. ), 46.1 g (0.49 mol) of 2-hydroxypyridine, and 73.7 g (0.53 mol) of potassium carbonate, add 500 mL of N, N-dimethylacetamide (DMAc) and 100 mL of toluene, and in an oil bath The mixture was reacted at 130 ° C. with stirring under a nitrogen atmosphere. When water produced by the reaction was azeotroped with toluene and reacted while being removed from the system with a Dean-Stark tube, almost no water was observed in about 3 hours. Thereafter, most of the toluene was removed, and the reaction was continued at 130 ° C. for 10 hours. The resulting reaction solution was allowed to cool and then filtered, and the filtrate was put into 2 L of water / methanol (9/1). The precipitated product was collected by filtration and dried.

  The dried product is placed in a 2 L three-necked flask equipped with a stirrer, thermometer, cooling tube, Dean-Stark tube and nitrogen-introduced three-way cock, and stirred in 1 L of toluene at 100 ° C. to retain residual moisture. It was dissolved while leaving. After allowing to cool, 142 g of a pale yellow 2,5-dichloro-4 ′-(2-pyridinyloxy) benzophenone represented by the following structural formula was obtained in a yield of 83% by filtering the precipitated crystals.

(4) Synthesis of polymer having sulfonic acid group Into a 1 L three-necked flask connected with a stirrer, a thermometer and a nitrogen introduction tube, 166 mL of dried DMAc was placed, and 13.4 g of the oligomer synthesized in (1). (1.8 mmol), 37.6 g (93.7 mmol) of neopentyl 3- (2,5-dichlorobenzoyl) benzenesulfonate synthesized in (2), 2,5-dichloro-4 synthesized in (3) '-(2-pyridinyloxy) benzophenone 1.61 g (4.7 mmol), bis (triphenylphosphine) nickel dichloride 2.62 g (4.0 mmol), triphenylphosphine 10.5 g (40.1 mmol), iodine A mixture of 0.45 g (3.0 mmol) sodium chloride and 15.7 g (240.5 mmol) zinc was added under nitrogen.

  The resulting mixture was heated with stirring (finally warmed to 82 ° C.) and allowed to react for 3 hours. An increase in viscosity in the system was observed during the reaction. The solution after the reaction was diluted with 175 mL of DMAc, stirred for 30 minutes, and then filtered using Celite as a filter aid. The obtained filtrate was put into a 1 L three-necked flask equipped with a stirrer, to which 24.4 g (281 mmol) of lithium bromide was added in 1/3 portions at intervals of 1 hour. The reaction was carried out at 5 ° C. for 5 hours under a nitrogen atmosphere. After the reaction, the mixture was cooled to room temperature, poured into 4 L of acetone and solidified. The coagulated product was collected by filtration, air-dried, pulverized with a mixer, put into 1500 mL of 1N sulfuric acid, and washed with stirring. After filtration, the filtrate is washed with ion-exchanged water until the pH of the washing solution becomes 5 or higher, and then dried at 80 ° C. overnight. Got. The molecular weight of polystyrene conversion measured by GPC (solvent: NMP buffer solution) of the obtained polymer having a sulfonic acid group was Mn = 63000 and Mw = 194000. The ion exchange capacity of this polymer was 2.33 meq / g. The obtained polymer having a sulfonic acid group was a compound (resin A) represented by the following structural formula.

(In the formula, o, m, k, and n are values calculated from the charged amounts of raw materials forming the structural unit.)

[Synthesis Example 2]
(1) Synthesis of hydrophilic unit To a 1 L flask equipped with a stirrer, a solution of neopentyl alcohol (45.30 g, 514 mmol) in pyridine (300 mL) was added, followed by 3,5-dichlorobenzenesulfonyl chloride (114.65 g). 467 mmol) was added in portions over 15 minutes with stirring. During this time, the reaction temperature was kept at 18-20 ° C. The flask containing the reaction mixture was stirred for an additional 30 minutes while cooling in an ice bath, and then ice-cooled 10% aqueous HCl (1600 mL) was added. Insoluble components in water were extracted with 700 mL of ethyl acetate, washed twice with 1N aqueous HCl (700 mL each), then twice with 5% aqueous NaHCO ₃ (700 mL each) and then dried over magnesium sulfate. It was. The solvent was removed using a rotary dryer and the residue was recrystallized with 500 mL of methanol. As a result, glossy colorless crystals of neopentyl 3,5-dichlorobenzenesulfonate represented by the following structural formula were obtained in a yield of 105.98 g and a yield of 76%.

(2) Synthesis of polymer having sulfonic acid group Addition system: In a mixture of 29.15 g (98.09 mmol) of neopentyl 3,5-dichlorobenzenesulfonate obtained and 1.65 g (6.28 mmol) of triphenylphosphine In addition, 71 mL of dehydrated DMAc was added under nitrogen to prepare an addition system solution.

  Reaction system: 2,5-dichlorobenzophenone 23.03 g (91.71 mmol), 2,6-dichlorobenzonitrile 1.75 g (10.19 mmol), triphenylphosphine 1.92 g (7.34 mmol) and zinc 15.99 g In a mixture of (244.57 mmol), 66 mL of dehydrated DMAc was added under nitrogen. The reaction system was heated to 60 ° C. with stirring, and then 1.60 g (2.45 mmol) of bis (triphenylphosphine) nickel dichloride was added to initiate polymerization, followed by stirring at 80 ° C. for 20 minutes. An exotherm and an increase in viscosity were observed with the reaction.

  The addition system solution was added to the obtained reaction system under nitrogen. After heating the system to 60 ° C. with stirring, 15.39 g (235.43 mmol) of zinc and 2.05 g (3.14 mmol) of bis (triphenylphosphine) nickel dichloride were added to further promote the polymerization, and 80 ° C. For 3 hours. An exotherm and an increase in viscosity were observed with the reaction.

  The resulting solution was diluted with 273 mL of DMAc and filtered using celite as a filter aid. To the filtrate, 29.82 g (343.33 mmol) of lithium bromide was added and reacted at 100 ° C. for 7 hours. After the reaction, the reaction solution was cooled to room temperature and poured into 3.2 L of water to be solidified. Acetone was added to the coagulated product, and washing and filtration were performed 4 times with stirring. The washed product was washed and filtered seven times while stirring with 1N sulfuric acid. Further, the washed product was washed and filtered with deionized water until the pH of the washing solution reached 5 or higher. The obtained washed product was dried at 75 ° C. for 24 hours to obtain 26.3 g of a polymer having a target sulfonic acid group.

  The molecular weight in terms of polystyrene measured by GPC (solvent: NMP buffer solution) of the polymer having a sulfonic acid group was 53,000 for Mn and 120,000 for Mw. Moreover, the ion exchange capacity of this polymer was 2.30 meq / g. When confirmed by NMR, the obtained polymer having a sulfonic acid group was a compound (resin B) having the following structural unit (q: r = 90: 10).

(In the formula, p is a value calculated from the charged amount of the raw material forming the structural unit.)

[Preparation of catalyst paste]
In an 80 mL polytetrafluoroethylene (PTFE) container, 80 g of zirconia balls having a diameter of 5 mm (“YTZ balls” manufactured by Nikkato Co., Ltd.), platinum ruthenium-supported carbon particles (“TEC61E54” manufactured by Tanaka Kikinzoku Co., Ltd.), Pt: 29 0.88% by weight, Ru: 23.2% by weight) 1.28 g and distilled water 3.60 g were added, and kneaded for 10 minutes at 200 rpm using a planetary ball mill ("P-5" manufactured by Fritsch). Thereafter, 12.02 g of n-propyl alcohol and 3.90 g of Nafion D2020 (manufactured by DuPont, polymer concentration 21% dispersion, ion exchange capacity 1.08 meq / g) were added, kneaded at 200 rpm for 30 minutes, and then zirconia balls. Was removed to obtain an anode catalyst paste.

  In an 80 mL PTFE container, 80 g of zirconia balls (YTZ balls) having a diameter of 5 mm, platinum-supported carbon particles (“TEC10E50E” manufactured by Tanaka Kikinzoku Kogyo Co., Ltd., Pt: 45.6% by mass), and distilled water 3 .64 g was added and kneaded for 10 minutes at 200 rpm using a planetary ball mill (P-5). Thereafter, 11.91 g of n-propyl alcohol and Nafion D2020 (4.40 g) were further added and kneaded at 200 rpm for 30 minutes, and then the zirconia balls were removed to obtain a cathode catalyst paste.

[Production of gas diffusion electrode]
In an 80 mL PTFE container, 80 g of zirconia balls (YTZ balls) having a diameter of 5 mm, carbon black (“Ketjen Black EC” manufactured by Lion Corporation) 0.48 g, distilled water 12.14 g, n-propyl alcohol 4.05 g, and Nafion D2020 (3.33 g) was added, kneaded at 200 rpm for 5 minutes using a planetary ball mill (P-5), and then the zirconia balls were removed to prepare a carbon black paste.

By applying the obtained carbon black paste on the gas diffusion layer 25BC manufactured by SGL CARBON with a doctor blade so that the weight increase after drying is 0.3 mg / cm ² and drying at 80 ° C. for 15 minutes. A base layer coating gas diffusion layer was prepared.

The anode catalyst paste was applied on the underlayer of the underlayer coating gas diffusion layer with a doctor blade so that the total amount of Pt and Ru was 0.6 mg / cm ^2, and then dried at 80 ° C. for 15 minutes. A gas diffusion electrode was produced.

After applying the cathode catalyst paste on the underlayer of the underlayer coating gas diffusion layer with a doctor blade so that the amount of Pt is 0.6 mg / cm ² , the cathode catalyst paste is dried at 80 ° C. for 15 minutes. Produced.

[Comparative Example 1]
(1) Film formation A solution obtained by dissolving 16 g of the resin A obtained in Synthesis Example 1 in 84 mL of a mixed solvent of methanol / NMP = 40/60 (mass ratio) was cast-coated on a PET film with a die coater, and 80 ° C. For 40 minutes, followed by drying at 120 ° C. for 40 minutes. The dried PET film with a coating film is immersed in a large amount of distilled water overnight, the remaining NMP in the coating film is removed, air-dried, and then peeled off from the PET film to form an electrolyte membrane 1 having a film thickness of 20 μm. Obtained.

(2) Measurement of glass transition temperature Using a dynamic viscoelastic device ("DVA-200" manufactured by IT Measurement Control Co., Ltd.), deformation mode: tensile, lower elastic modulus: 1000 Pa, lower limit movement: 0 cN, temperature rise By measuring under the conditions of speed: 2 ° C./min, measurement frequency: 10 Hz, strain: 0.05%, static / power ratio: 1.5, upper limit elongation: 50%, minimum load: 0.5 cN, temperature and A curve with the elastic modulus was obtained, and the glass transition temperature was determined from the inflection point of the obtained curve. The glass transition temperature of the electrolyte membrane 1 was 190 ° C.
In addition, the glass transition temperature of the film | membrane obtained from the same resin and the same manufacturing method is the same irrespective of a film thickness.

(3) Fabrication of fuel cell An anode gas diffusion electrode and a cathode gas diffusion electrode cut out to 5 cm × 5 cm on both surfaces of one electrolyte membrane 1 are overlapped and evaluated so that the catalyst paste application side and the electrolyte membrane 1 surface are in contact with each other. A fuel cell for evaluation having an effective area of 25 cm ² was fabricated by incorporating the battery into a cell for use (“JFC-025-01H” manufactured by Chemix Co., Ltd.).

(4) Output voltage measurement To the anode gas diffusion electrode side of the obtained fuel cell for evaluation, pure hydrogen gas containing water vapor with a dew point of 80 ° C. was supplied at 0.5 L / min, and the cathode gas diffusion electrode side In addition, air containing water vapor with a dew point of 80 ° C. is supplied at 2 L / min, the temperature of the fuel cell is controlled to 80 ° C., and the current sweep from 0 to 1 A / cm ^{2 is} repeated 120 times for pretreatment. Did.
Air is supplied to the cathode electrode side of the evaluation fuel cell at a back pressure of 120 kPa and a utilization rate of 40%, pure hydrogen is supplied to the anode electrode side at a back pressure of 120 kPa and a utilization rate of 70%, the cell temperature is 90 ° C., the cathode electrode The output voltage at a current density of 1.0 A / cm ² was measured with a side relative humidity of 30% and an anode electrode side relative humidity of 30%. The results are shown in Table 1.

(5) Precipitation amount of platinum inside electrolyte membrane by potential cycle 0.05L of pure hydrogen gas containing water vapor with dew point of 45 ° C on the anode gas diffusion electrode side of the evaluation fuel cell used in (4) Supply at 0.1 L / min to the cathode gas diffusion electrode side containing water vapor with a dew point of 45 ° C., and control the temperature of the fuel cell to 50 ° C., and a potentiogalvanostat (Solartron 1287 type) was used, and the cathode voltage with respect to the anode was reciprocated 100 times from 0.6 V to 1.5 V at a sweep rate of 0.1 V / s. Thereafter, the membrane was taken out from the fuel cell, the electrode adhered to the membrane was removed, and the amount of platinum deposited in the membrane was quantified by elemental analysis with a fluorescent X-ray analyzer (Spectrum "Magix"). The results are shown in Table 1.

[Example 1]
(1) Film formation A solution obtained by dissolving 16 g of the resin A obtained in Synthesis Example 1 in 84 g of a mixed solvent of methanol / NMP = 40/60 (mass ratio) was cast-coated on a PET film with a die coater, and 80 ° C. For 40 minutes, followed by drying at 120 ° C. for 40 minutes. Thereafter, a solution obtained by dissolving 5 g of polyhydroxystyrene (manufactured by SIGMA-ALDRICH) in 120 g of a mixed solvent of methanol / NMP = 20/80 (mass ratio) on the dried coating film was dried with a die coater. The thickness was controlled so that the film thickness was 1 μm, and cast coating was performed, followed by drying at 120 ° C. for 60 minutes. The dried PET film with a coating film was immersed in a large amount of distilled water overnight to remove the remaining NMP in the coating film. Thereafter, the laminate was air-dried to obtain a laminate in which a polyhydroxystyrene layer having a thickness of 1 μm and a layer having a thickness of 20 μm composed of only the resin A were laminated in this order. In addition, since the functional group which the used polyhydroxystyrene has is a phenolic hydroxyl group, its pKa is 3 or more. Moreover, in the following evaluation, what remove | excluded PET film from this laminated body was used as the electrolyte membrane 2 (21 micrometers in thickness).

(3) Fabrication of fuel cell An anode gas diffusion electrode and a cathode gas diffusion electrode cut out to 5 cm × 5 cm on both surfaces of one electrolyte membrane 2, and the catalyst paste application side of the cathode gas diffusion electrode is in contact with the polyhydroxystyrene layer, and the anode The gas diffusion electrodes are stacked so that the catalyst paste application side is in contact with the layer made of resin A, and are assembled in an evaluation cell (“JFC-025-1H” manufactured by Chemix Co., Ltd.) to produce a fuel cell with an effective area of 25 cm ^2. did.

(4) Output voltage measurement The output voltage was measured by the same method as in Comparative Example 1 except that the obtained fuel cell was used. The results are shown in Table 1.

(5) Platinum deposition amount inside electrolyte membrane by potential cycle The amount of platinum deposition inside the electrolyte membrane by potential cycle was determined in the same manner as in Comparative Example 1 except that the obtained fuel cell was used. The results are shown in Table 1.

[Comparative Example 2]
(1) Film Formation A solution obtained by dissolving 15 g of the resin B obtained in Synthesis Example 2 in 85 g of a mixed solvent of methanol / NMP = 40/60 (mass ratio) was cast-coated on a PET film with a die coater, and 80 ° C. For 40 minutes, followed by drying at 120 ° C. for 40 minutes. The dried PET film with a coating film is immersed in a large amount of distilled water overnight, the remaining NMP in the coating film is removed, then air-dried, and peeled off from the PET film to form an electrolyte membrane 3 having a film thickness of 20 μm. Obtained.

(2) Measurement of glass transition temperature The glass transition temperature of the electrolyte membrane 3 measured by the same method as in Comparative Example 1 was 166 ° C.

(3) Production of Fuel Cell A fuel cell was produced in the same manner as in Comparative Example 1 except that the electrolyte membrane 3 was used.

(4) Output voltage measurement The output voltage was measured by the same method as in Comparative Example 1 except that the obtained fuel cell was used. The results are shown in Table 1.

(5) Platinum deposition amount inside electrolyte membrane by potential cycle The amount of platinum deposition inside the electrolyte membrane by potential cycle was determined in the same manner as in Comparative Example 1 except that the obtained fuel cell was used. The results are shown in Table 1.

[Example 2]
(1) Film Formation A solution obtained by dissolving 15 g of the resin B obtained in Synthesis Example 2 in 85 g of a mixed solvent of methanol / NMP = 40/60 (mass ratio) was cast-coated on a PET film with a die coater, and 80 ° C. For 40 minutes, followed by drying at 120 ° C. for 40 minutes. Thereafter, a solution obtained by dissolving 5 g of polyhydroxystyrene (manufactured by SIGMA-ALDRICH) in 120 g of a mixed solvent of methanol / NMP = 20/80 (mass ratio) on the dried coating film was dried with a die coater. The thickness was controlled so that the film thickness was 1 μm, and cast coating was performed, followed by drying at 120 ° C. for 60 minutes. The dried PET film with a coating film was immersed in a large amount of distilled water overnight to remove the remaining NMP in the coating film. Thereafter, the laminate was air-dried to obtain a laminate in which a polyhydroxystyrene layer having a thickness of 1 μm and a layer having a thickness of 20 μm composed of only the resin B were laminated in this order. In the following evaluation, a material obtained by removing the PET film from this laminate was used as the electrolyte membrane 4 (thickness: 21 μm).

(3) Production of Fuel Cell A fuel cell was produced in the same manner as in Example 1 except that the electrolyte membrane 4 was used.

(4) Output voltage measurement The output voltage was measured by the same method as in Comparative Example 1 except that the obtained fuel cell was used. The results are shown in Table 1.

(5) Platinum deposition amount inside electrolyte membrane by potential cycle The amount of platinum deposition inside the electrolyte membrane by potential cycle was determined in the same manner as in Comparative Example 1 except that the obtained fuel cell was used. The results are shown in Table 1.

[Example 3]
(1) Film Formation In Example 2, except that polystyrene (manufactured by SIGMA-ALDRICH) was used instead of polyhydroxystyrene, it was composed of a polystyrene layer having a thickness of 1 μm and resin B only, in the same manner as in Example 2. A laminated body in which layers having a thickness of 20 μm were laminated in this order was obtained. In addition, the used polystyrene does not have a functional group showing acidity. Moreover, in the following evaluation, what remove | excluded PET film from this laminated body was used as the electrolyte membrane 5 (21 micrometers in thickness).

(3) Fabrication of fuel cell Anode gas diffusion electrode and cathode gas diffusion electrode cut out to 5 cm × 5 cm on both surfaces of one electrolyte membrane 5, the catalyst paste application side of the cathode gas diffusion electrode is in contact with the polystyrene layer, and anode gas diffusion The electrodes were superimposed so that the catalyst paste application side of the electrode was in contact with the layer made of resin B, and assembled into an evaluation cell (“JFC-025-01H” manufactured by Chemix Co., Ltd.) to produce a fuel cell with an effective area of 25 cm ² .

(4) Output voltage measurement The output voltage was measured by the same method as in Comparative Example 1 except that the obtained fuel cell was used. The results are shown in Table 1.

(5) Platinum deposition amount inside electrolyte membrane by potential cycle The amount of platinum deposition inside the electrolyte membrane by potential cycle was determined in the same manner as in Comparative Example 1 except that the obtained fuel cell was used. The results are shown in Table 1.

[Comparative Example 3]
A fuel cell was prepared in the same manner as in Comparative Example 1 except that Nafion NRE212CS (manufactured by DuPont) having a thickness of 50 μm was used as the electrolyte membrane 6 instead of the electrolyte membrane 1, and the output voltage was measured. Further, the amount of platinum deposited inside the electrolyte membrane was determined by the potential cycle in the same manner as in Comparative Example 1. The results are shown in Table 1.

[Example 4]
(1) Film formation A solution obtained by dissolving 5 g of polyhydroxystyrene (manufactured by SIGMA-ALDRICH) in 120 g of a mixed solvent of methanol / NMP = 20/80 (mass ratio) on a Nafion NRE212CS film is dried with a die coater. The thickness was controlled so that the film thickness was 1 μm, and cast coating was performed, followed by drying at 120 ° C. for 60 minutes. The dried Nafion film with a coating film was immersed in a large amount of distilled water overnight to remove the remaining NMP in the coating film. Thereafter, by air drying, a laminate (electrolyte film 7 (thickness 51 μm)) in which a polyhydroxystyrene layer having a thickness of 1 μm and a layer having a thickness of 50 μm composed of only Nafion NRE212CS were laminated in this order was obtained.

(3) Production of Fuel Cell A fuel cell was produced in the same manner as in Example 1 except that the electrolyte membrane 7 was used.

(4) Output voltage measurement The output voltage was measured by the same method as in Comparative Example 1 except that the obtained fuel cell was used. The results are shown in Table 1.

(5) Platinum deposition amount inside electrolyte membrane by potential cycle The amount of platinum deposition inside the electrolyte membrane by potential cycle was determined in the same manner as in Comparative Example 1 except that the obtained fuel cell was used. The results are shown in Table 1.

[Reference Example 1]
(1) Film Formation Electrolyte film 8 was obtained by the same method as Comparative Example 2 except that the film thickness was adjusted to 10 μm.

(3) Fabrication of fuel cell Two electrolyte membranes 8 are overlapped, and the anode gas diffusion electrode and the cathode gas diffusion electrode cut out to 5 cm × 5 cm on the outside thereof are in contact with the catalyst paste application side and the surface of the electrolyte membrane 8 And a fuel cell having an effective area of 25 cm ² was fabricated by being superimposed on each other and incorporated in an evaluation cell (“JFC-025-01H”).

(4) Output voltage measurement The output voltage was measured by the same method as in Comparative Example 1 except that the obtained fuel cell was used. The results are shown in Table 1.

(5) Platinum deposition amount inside electrolyte membrane by potential cycle The amount of platinum deposition inside the electrolyte membrane by potential cycle was determined in the same manner as in Comparative Example 1 except that the obtained fuel cell was used. The results are shown in Table 1.

[Example 5]
(1) Film formation The film thickness after drying the solution which melt | dissolved 5 g of polystyrene (made by SIGMA-ALDRICH) in the tetrahydrofuran solvent 120g on the electrolyte membrane 8 with a PET film obtained in Reference Example 1 with a die coater. The thickness is controlled so that the thickness becomes 0.5 μm, cast coating is performed, and drying is performed at 80 ° C. for 60 minutes, so that a polystyrene layer having a thickness of 0.5 μm and a layer having a thickness of 10 μm composed of only the resin B are obtained. The laminated body laminated | stacked in order was obtained. In the following evaluation, a material obtained by removing the PET film from this laminate was used as the electrolyte membrane 9 (thickness 10.5 μm).

(3) Fabrication of a fuel cell The electrolyte membrane 8 and the electrolyte membrane 9 are overlapped so that the polystyrene layer is on the outside, and an anode gas diffusion electrode and a cathode gas diffusion electrode cut out to 5 cm × 5 cm are further formed outside the anode gas. The diffusion electrode catalyst paste application side is in contact with the electrolyte membrane 8 and the cathode gas diffusion electrode catalyst paste application side is in contact with the polystyrene layer of the electrolyte membrane 9 so that they are stacked and incorporated in the evaluation cell ("JFC-025-01H"). A fuel cell having an effective area of 25 cm ² was produced.

(4) Output voltage measurement The output voltage was measured by the same method as in Comparative Example 1 except that the obtained fuel cell was used. The results are shown in Table 1.

(5) Platinum deposition amount inside electrolyte membrane by potential cycle The amount of platinum deposition inside the electrolyte membrane by potential cycle was determined in the same manner as in Comparative Example 1 except that the obtained fuel cell was used. The results are shown in Table 1.

[Example 6]
(1) Film formation On the electrolyte film 8 with a PET film obtained in Reference Example 1, a solution obtained by dissolving 5 g of polyvinyl alcohol (manufactured by SIGMA-ALDRICH) in 120 g of an acetone solvent is dried with a die coater. The thickness is controlled so that the thickness becomes 1 μm, cast coating is performed, and drying is performed at 80 ° C. for 60 minutes. A laminated body was obtained. In addition, since the functional group which the used polyvinyl alcohol has is a hydroxy group, its pKa is 3 or more. Moreover, in the following evaluation, what remove | excluded PET film from this laminated body was used as the electrolyte membrane 10 (11 micrometers in thickness).

(3) Fabrication of fuel cell The electrolyte membrane 8 and the electrolyte membrane 10 are overlapped so that the polyvinyl alcohol layer is in the middle, and the anode gas diffusion electrode and the cathode gas diffusion electrode cut out to 5 cm × 5 cm are further formed outside the catalyst paste. The fuel cell having an effective area of 25 cm ² was manufactured by superimposing the coating side and the electrolyte membrane 8 so that the surface was in contact with each other and incorporating them in an evaluation cell (“JFC-025-01H”).

(4) Output voltage measurement The output voltage was measured by the same method as in Comparative Example 1 except that the obtained fuel cell was used. The results are shown in Table 1.

(5) Platinum deposition amount inside electrolyte membrane by potential cycle The amount of platinum deposition inside the electrolyte membrane by potential cycle was determined in the same manner as in Comparative Example 1 except that the obtained fuel cell was used. The results are shown in Table 1.

[Example 7]
(1) Film Formation Example 6 except that polyhydroxystyrene (manufactured by SIGMA-ALDRICH) was used instead of polyvinyl alcohol and cast coating was performed so that a 0.5 μm-thick polyhydroxystyrene layer was obtained. In the same manner as in Example 6, a laminated body in which a polyhydroxystyrene layer having a thickness of 0.5 μm and a layer having a thickness of 10 μm composed of only the resin B were laminated in this order was obtained. Moreover, in the following evaluation, what removed the PET film from this laminated body was used as the electrolyte membrane 11 (thickness 10.5 micrometer).

(3) Fabrication of fuel cell The electrolyte membrane 8 and the electrolyte membrane 11 are overlapped so that the polyhydroxystyrene layer is in the middle, and further, the anode gas diffusion electrode and the cathode gas diffusion electrode cut out to 5 cm × 5 cm are catalyzed on the outside. Each of the paste coating side and the electrolyte membrane 8 surface was overlapped so as to be in contact with each other and assembled in an evaluation cell (“JFC-025-01H”) to produce a fuel cell having an effective area of 25 cm ² .

(4) Output voltage measurement The output voltage was measured by the same method as in Comparative Example 1 except that the obtained fuel cell was used. The results are shown in Table 1.

(5) Platinum deposition amount inside electrolyte membrane by potential cycle The amount of platinum deposition inside the electrolyte membrane by potential cycle was determined in the same manner as in Comparative Example 1 except that the obtained fuel cell was used. The results are shown in Table 1.

[Example 8]
(3) Fabrication of fuel cell The electrolyte membrane 11 is folded so that the polyhydroxystyrene layer is on the inner side, and the anode gas diffusion electrode and the cathode gas diffusion electrode cut out to 5 cm × 5 cm on both outer sides are connected to the catalyst paste application side and the electrolyte. Each of the membranes 8 was overlapped so that the surface was in contact with each other and incorporated in an evaluation cell (“JFC-025-01H” manufactured by Chemix Co., Ltd.) to produce a fuel cell having an effective area of 25 cm ² .

(4) Output voltage measurement The output voltage was measured by the same method as in Comparative Example 1 except that the obtained fuel cell was used. The results are shown in Table 1.

(5) Platinum deposition amount inside electrolyte membrane by potential cycle The amount of platinum deposition inside the electrolyte membrane by potential cycle was determined in the same manner as in Comparative Example 1 except that the obtained fuel cell was used. The results are shown in Table 1.

  According to the solid polymer electrolyte membrane of the present invention, it has been found that the amount of platinum deposited inside the electrolyte membrane can be reduced without lowering the output voltage. Therefore, the solid polymer electrolyte membrane of the present invention is unlikely to deteriorate, and it is considered that by using such a solid polymer electrolyte membrane, a fuel cell and a water electrolysis device having excellent long-term stability can be obtained.

10: membrane-electrode assembly 11: anode gas diffusion layer 12: anode catalyst layer 13: electrolyte membrane (A)
14: Non-electrolyte layer 15: Cathode catalyst layer 16: Cathode gas diffusion layer 17: Solid polymer electrolyte membrane 13 ′: Structure 14 ′ formed by bending the electrolyte membrane (A): Non-electrolyte layer 17 ′: Solid polymer electrolyte film

Claims (10)

  A solid polymer electrolyte membrane comprising an electrolyte membrane (A) containing a polymer having ion exchange groups and a non-electrolyte layer having a polymer substantially free of sulfonic acid groups.   The solid polymer electrolyte membrane according to claim 1, wherein the non-electrolyte layer is a layer substantially free of a polymer having a functional group having a pKa of 3 or less.   The solid polymer electrolyte membrane according to claim 1 or 2, wherein the non-electrolyte layer has a thickness of 5 µm or less.   The solid polymer electrolyte membrane according to any one of claims 1 to 3, comprising two or more electrolyte membranes (A).   The solid polymer electrolyte membrane according to any one of claims 1 to 4, comprising a structure formed by bending the electrolyte membrane (A). The solid polymer electrolyte membrane is an electrolyte membrane used between a cathode and an anode;
The solid polymer electrolyte membrane according to any one of claims 1 to 5, wherein the non-electrolyte layer is not in contact with the anode.   A membrane-electrode assembly in which a gas diffusion layer, a catalyst layer, the solid polymer electrolyte membrane according to any one of claims 1 to 6, a catalyst layer, and a gas diffusion layer are laminated in this order.   A fuel cell comprising the membrane-electrode assembly according to claim 7.   The water electrolysis cell containing the laminated body on which the catalyst layer, the solid polymer electrolyte membrane of any one of Claims 1-6, and the catalyst layer were laminated | stacked in this order.   A water electrolysis apparatus comprising the water electrolysis cell according to claim 9.