JP2003257453A - High polymer solid electrolyte, manufacturing method therefor, and solid high polymer type fuel cell by use of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a novel high polymer solid electrolyte capable of reducing methanol crossover and achieving a high output to provide a manufacturing method therefor and a high performance, solid high polymer type fuel cell by use of the electrolyte. <P>SOLUTION: This high polymer solid electrolyte is constituted in such a way that polymer having an anionic group and a three-dimensional crosslinked body containing elements other than carbon have an inside penetration high polymer network structure. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polymer electrolyte, a method for producing the same, and a polymer electrolyte fuel cell using the same.

[0002]

2. Description of the Related Art A fuel cell is a power generator which produces little emissions, has high energy efficiency, and has a low environmental burden. For this reason, it has been in the spotlight again in recent years with the recent increase in global environmental protection. It is a power generation device that is expected in the future as a power generation device for a relatively small-scale distributed power generation facility and a mobile body such as an automobile or a ship as compared with a conventional large-scale power generation facility. In addition, it is attracting attention as a power source for small mobile devices and mobile devices, and is expected to be installed in mobile phones and personal computers in place of secondary batteries such as nickel hydrogen batteries and lithium ion batteries.

In the polymer electrolyte fuel cell, a conventional polymer electrolyte fuel cell (hereinafter referred to as PE
In addition to FC), a direct methanol fuel cell that directly supplies methanol (hereinafter referred to as DMFC) is also drawing attention. Although the DMFC has a lower output than the conventional PEFC, it has a merit that the energy density is high because the fuel is liquid and the reformer is not used, and the usage time of the portable device per filling is long. is there.

In a fuel cell, usually, an electrode of an anode and a cathode in which a reaction responsible for power generation takes place, and an electrolyte membrane serving as an ion conductor between the anode and the cathode, a membrane-electrode composite (M
EA), and the cells in which the MEA is sandwiched by the separators are configured as a unit. Here, the electrode is composed of an electrode base material (also referred to as a gas diffusion electrode or a current collector) that promotes gas diffusion and collects (supply) electricity, and an electrode catalyst layer that actually serves as an electrochemical reaction field. ing. For example, in the anode electrode of a polymer electrolyte fuel cell, fuel such as hydrogen gas reacts in the catalyst layer of the anode electrode to generate protons and electrons, the electrons are conducted to the electrode substrate, and the protons are converted to the polymer solid electrolyte. Conduct. Therefore, the anode electrode is required to have good gas diffusivity, electron conductivity, and ionic conductivity. On the other hand, in the cathode electrode, an oxidizing gas such as oxygen or air reacts with the protons conducted from the solid polymer electrolyte and the electrons conducted from the electrode base material in the catalyst layer of the cathode electrode to generate water. Therefore, in the cathode electrode, it is necessary to efficiently discharge the generated water as well as gas diffusibility, electron conductivity, and ion conductivity.

Among the polymer electrolyte fuel cells, the DMFC that uses an organic solvent such as methanol as a fuel,
Performance different from that of conventional PEFCs that use hydrogen gas as fuel is required. That is, in DMFC, fuel such as aqueous methanol solution reacts in the anode electrode catalyst layer in the anode electrode to generate protons, electrons and carbon dioxide, the electrons are conducted to the electrode substrate, the protons are conducted to the polymer solid electrolyte, Carbon dioxide passes through the electrode base material and is released to the outside of the system. Therefore, in addition to the required characteristics of the conventional PEFC anode electrode,
Fuel permeability such as aqueous methanol solution is also required. Furthermore, in the cathode electrode of DMFC, in addition to the reaction similar to conventional PEFC, the reaction of methanol and oxygen, which has permeated the electrolyte membrane, or oxidizing gas such as air, to generate carbon dioxide and water in the catalyst layer of the cathode electrode. Occur. Therefore, the conventional
Since more water is produced than PEFC, it is necessary to discharge water more efficiently.

[0006] In the DMFC, as described above, crossover occurs in which methanol as a fuel permeates through the solid polymer electrolyte, so that there is a problem that the battery output and energy efficiency are reduced. In order to prevent methanol crossover of the polymer solid electrolyte, measures for reducing the concentration of methanol supplied to the anode, a novel polymer electrolyte different from the conventional perfluoro-based proton exchange membrane, and the like are known (for example, Patent Document 1). .

[0007] Further, there has been proposed a composite membrane formed by copolymerizing a proton conductive polymer and a siloxane having a nitrogen atom-containing group with a metal oxide (Patent Document 2).

[0008]

[Patent Document 1] International Publication No. 98/22989 Pamphlet

[0009]

[Patent Document 2] Japanese Unexamined Patent Publication No. 2002-110200

[0010]

[Problems to be Solved by the Invention] However, international publication 98
The method described in the / 22989 pamphlet or the like has a problem that it is difficult to increase the crosslinking density and there is a limit to the suppression of methanol crossover. Further, in the method described in Patent Document 2, the proton-conducting polymer has no polar group other than an anionic group in its main chain, and the three-dimensional crosslinked product having an element other than carbon as a crosslinking point also has an ionic group. Since it does not have it, it has the drawback of low conductivity. The present invention solves the above problems, provides a novel polymer electrolyte capable of suppressing methanol crossover and achieving high output, a method for producing the same, and a high-performance solid polymer fuel cell using the same. With the goal.

[0011]

The present invention has the following constitution in order to solve the above problems. That is, the polymer electrolyte of the present invention is composed of a polymer having an anionic group and a three-dimensional crosslinked body having an element other than carbon as a crosslinking point, and these have an internal penetrating polymer network structure. To do. Further, the method for producing a polymer solid electrolyte of the present invention uses at least a solution containing a three-dimensionally crosslinkable compound having an element other than carbon as a crosslinking point and / or its hydrolyzate and a polymer having an anionic group. A three-dimensionally crosslinkable compound having an element other than carbon as a crosslinking point and / or a hydrolyzate thereof is subjected to condensation polymerization to form an internally penetrating polymer stitch structure. Furthermore, the polymer electrolyte fuel cell of the present invention is characterized by being configured using the polymer solid electrolyte of the present invention.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below.

The solid polymer electrolyte of the present invention is composed of a polymer having an anionic group and a three-dimensional cross-linked body having an element other than carbon as a cross-linking point, and these have an internally penetrating polymer network structure. Is characterized by. The international publication 98 mentioned above
/ 22989 pamphlet, etc., polystyrene sulfonic acid-divinylbenzene crosslinked product and PVDF
There is a polymer solid electrolyte having an internally penetrating polymer network structure. However, this has problems that it is difficult to increase the crosslink density and that the oxidation resistance at the crosslink points is low. Therefore, there is a problem that a sufficient effect of suppressing methanol crossover and durability cannot be obtained. On the other hand, in the polymer solid electrolyte of the present invention, the polymer having an anionic group and the three-dimensional crosslinked body having an element other than carbon as a crosslinking point have an internally penetrating polymer network structure, and thus the anion has a high crosslinking density. Swelling of the polymer having a functional group is suppressed,
A high effect of suppressing methanol crossover can be obtained. Also, high durability can be obtained. Further, a polymer electrolyte fuel cell using such a polymer solid electrolyte has high output, high fuel efficiency, and space saving can be achieved.

The polymer solid electrolyte of the present invention is composed of a polymer having an anionic group and a three-dimensional crosslinked body having an element other than carbon as a crosslinking point, and these have an internal penetrating polymer network structure. The internal penetrating polymer network structure refers to a state in which a polymer having an anionic group is present inside the network of the three-dimensional crosslinked body. In addition to the internal penetrating polymer network structure portion, the polymer solid electrolyte of the present invention may include a portion having a polymer having an anionic group or a three-dimensional crosslinkable polymer having an element other than carbon as a crosslinking point. However, if these sites are included, the proton conductivity of the solid polymer electrolyte may be reduced and the effect of suppressing methanol crossover may be reduced. Therefore, the proportion of the internal penetrating network structure portion in the polymer solid electrolyte is preferably 30% or more, and more preferably 50% or more of the whole polymer solid electrolyte.

In the present invention, the anionic group is not particularly limited as long as it is an atomic group having a negative charge, but a group having a proton exchange ability is preferable. As such a functional group, a sulfonic acid group, a phosphoric acid group, a carboxyl group, a phosphonic acid group or the like is preferably used.

The polymer having an anionic group in the present invention can be obtained by introducing an anionic group into the polymer, but the polymer is not particularly limited. Examples of the polymer include polytetrafluoroethylene (PTFE: the following abbreviations are shown in parentheses), polytetrafluoroethylene-perfluoroalkyl ether copolymer (PFA),
Polytetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-ethylene copolymer (ETFE), polyvinylidene fluoride (PV
DF) and other fluorine-containing resins, polyimide (PI), polyphenylene sulfide sulfone (PPSS), polysulfone (PSF), polyphenylene sulfide (PPS), polyphenylene oxide (PPO), polyether ketone (PEK),
Polyether ether ketone (PEEK), polyether sulfone (PES), polyether ether sulfone (PEE)
In addition to heat-resistant and oxidation-resistant polymers such as S) and polybenzimidazole (PBI), those having polyphosphazene (PPho) as a main skeleton are preferably used.

Nafion, which has no main chain having a polar group but has a PTFE main chain and a side chain of polyperfluoroalkyl ether sulfonic acid, is also preferably used. Further, a polymer having at least one kind of polar group different from the anionic group in the main chain is preferable. Here, the polar group is not particularly limited, but a functional group capable of coordinating water is preferable. Sulfonyl group as such polar group (-SO ₂ -), oxy group (-O-), a thio group (-S
-), Carbonyl group (-CO-), ester group (-CO
O-), an amide group (-NRCO-), an imide group, and a polar group represented by formula (1) or formula (2) are preferable. Formula (1)

[0018]

[Chemical 7]

Formula (2)

[0020]

[Chemical 8]

(Here, R, R ₁ and R ₂ represent an organic group,
R ₁ and R ₂ may be the same or different. ) Among the above-mentioned polymers, polyphenylene sulfide sulfone represented by the following formula (3), polyphenylene sulfide represented by the following formula (4), polyphosphazene represented by the following formula (5), and polyimide represented by the following formula (6) , Polybenzimidazole, polysulfone, polyphenylene oxide represented by the following formula (10), polyether ether ketone represented by the following formula (11), polyether ketone represented by the following formula (12), represented by the following formula (13) Polyether ether sulfone represented by the formula (1) and polyether sulfone represented by the following formula (14) are particularly preferably used. Formula (3)

[0022]

[Chemical 9]

Equation (4)

[0024]

[Chemical 10]

Equation (5)

[0026]

[Chemical 11]

Equation (6)

[0028]

[Chemical 12]

Equation (7)

[0030]

[Chemical 13]

Equation (8)

[0032]

[Chemical 14]

Formula (9)

[0034]

[Chemical 15]

Equation (10)

[0036]

[Chemical 16]

Equation (11)

[0038]

[Chemical 17]

(Where Z is an organic group containing an aromatic ring, n is the number of repetitions, R ₁ and R ₂ are organic groups, and R ₁ and R _{2 are}
May be the same or different. In the present invention, the three-dimensional crosslinked product having an element other than carbon as a crosslinking point is not particularly limited as long as it contains an element other than carbon as a crosslinking point. In addition, a two-dimensional polymer having a polymerization point of an element other than carbon may be included in order to control the crosslink density. Furthermore, in order to adjust the degree of polymerization, monofunctional compounds that terminate the polymerization can also be included. The elements serving as the three-dimensional cross-linking points are silicon, titanium, zirconium, aluminum, boron, in view of various kinds, high reactivity, easy synthesis, and easy availability.
Phosphorus and iron are preferably used. Above all, silicon,
Titanium and aluminum are preferable, and silicon is most preferable. The three-dimensional crosslinked product having an element other than carbon as a crosslinking point may have an ionic group from the viewpoint of improving ionic conductivity and compatibility with a polymer having an anionic group. As the ionic group, a sulfonic acid group, a carboxyl group and a phosphonic acid group are preferable. It is also preferable to use two or more types of these groups at the same time, and in this case, effects such as improvement in durability may be obtained as compared with when used alone. When a three-dimensional crosslinked product having such an ionic group is used, it is possible to increase the crosslink density and reduce only the methanol crossover without impairing the ionic conductivity. The ratio of the three-dimensional crosslinked body having an element other than carbon as a crosslinking point and the polymer having an anionic group is not particularly limited. For example, the three-dimensional crosslinked body having an element other than carbon as a crosslinking point in the polymer solid electrolyte is used. The weight ratio of can vary from 1 to 99%. These ratios are appropriately adjusted depending on the required characteristics of the solid polymer electrolyte and the compound used.

In the production of the polymer solid electrolyte, the solution for producing the polymer solid electrolyte contains at least a three-dimensional crosslinkable compound having an element other than carbon as a crosslinking point and / or its hydrolyzate and an anionic group. It is preferable to use a solution containing the polymer having the above because it is easy to form an internally penetrating polymer network structure.

The three-dimensionally crosslinkable compound having an element other than carbon as a crosslinking point is, for example, a metal hydroxide, a metal alkoxide compound, a metal acyloxide, a metal halide compound, a mixture of a metal hydride compound and a carbon-carbon multiple bond-containing compound. Can be mentioned. Among these, metal alkoxide compounds, metal phenoxide compounds, metal acyloxides and metal halide compounds are preferable from the viewpoints of abundance of available compounds and easy handling. Among them, silicon alkoxide, silicon phenoxide, silicon acyloxide, and silicon halide are particularly preferable. More preferably, it is at least one compound selected from the group consisting of compounds represented by the following general formula (I) and compounds represented by the following general formula (II). General formula (I)

[0042]

[Chemical 18]

General formula (II)

[0044]

[Chemical 19]

[In the formulas (I) and (II), Y ^{1 to} Y ⁶ are each independently an optionally substituted alkyl group, an optionally substituted aryl group, a hydroxy group or an optionally substituted group. Represents a substituent selected from a good alkoxy group, an optionally substituted aryloxy group, an optionally substituted acyloxy group and a halogen group, and Y ¹
At least one of Y ⁴ to Y ⁴ represents a substituent selected from a hydroxy group, an optionally substituted alkoxy group, an optionally substituted aryloxy group, an optionally substituted acyloxy group and a halogen group. . Q represents a divalent organic group. In the formula, Y ^{1 to} Y ⁴ are each independently an alkyl group which may be substituted, an aryl group which may be substituted, a hydroxy group, an alkoxy group which may be substituted, or an acyloxy which may be substituted. Represents a substituent selected from a group and a halogen group, and is at least 1 of Y ^{1 to} Y ^4.
Represents a substituent selected from a hydroxy group, an optionally substituted alkoxy group, an optionally substituted acyloxy group and a halogen group. Specific examples thereof include alkyl groups such as methyl group, ethyl group, vinyl group, isopropyl group, t-butyl group, chloropropyl group, 3,3,3.
-A halogenated alkyl group such as a trifluoropropyl group,
Epoxy group-containing alkyl groups such as γ-glycidoxypropyl group and β- (3,4-epoxycyclohexyl) ethyl group, (meth) acryl group-containing acryl such as γ-methacryloxypropyl group and γ-acryloxypropyl group Group, other mercapto group, cyano group, alkyl group having various substituents such as amino group, phenyl group, naphthyl group, optionally substituted aryl group such as styryl group, hydroxy group, methoxy group, ethoxy group, Alkoxy group which may be substituted such as methoxyethoxy group, acyloxy group which may be substituted such as acetoxy group, aryloxy group which may be substituted such as phenoxy group, chloro group, halogen group such as bromo group, And so on.

Y ^{1 to} Y ⁶ are independent of each other and may be the same or different from each other.

Q represents a divalent organic group. There is no problem even if Q contains a carbon atom such as an oxygen atom or a nitrogen atom, or a hetero atom other than hydrogen. Furthermore, the organic group may be in the form of a chain, and even if an oxygen atom or the like is present as an epoxy ring, there is no problem, and it is preferable in that it contributes as a functional group during curing. .

Specific examples thereof include ethenediyl group, methylene group, ethylene group, propylene group, butanediyl group, pentanediyl group, hexanediyl group, heptanediyl group, octanediyl group, nonanediyl group, decandiyl group, undecanediyl group, dodecanediyl group. , An octadienediyl group and a group of the following formula

[0049]

[Chemical 20]

And the like.

Specific examples of the compounds represented by the general formulas (I) and (II) include tetramethoxysilane, tetraethoxysilane, tetrabutoxysilane, tetrachlorosilane, methyltrimethoxysilane and methyltriethoxysilane. , Methyltrimethoxyethoxysilane, methyltriacetoxysilane, methyltripropoxysilane, methyltributoxysilane, methyltrichlorosilane, ethyltrimethoxysilane, ethyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane , Vinyltrimethoxyethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltriacetoxysilane, γ-chloropropyltrimethoxysilane,
γ-chloropropyltriethoxysilane, γ-chloropropyltriacetoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ −
Mercaptopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, β-cyanoethyltriethoxysilane, methyltriphenoxysilane, chloromethyltrimethoxysilane,
Chloromethyltriethoxysilane, glycidoxymethyltrimethoxysilane, glycidoxymethyltriethoxysilane, α-glycidoxyethyltrimethoxysilane,
α-glycidoxyethyltriethoxysilane, β-glycidoxyethyltrimethoxysilane, β-glycidoxyethyltriethoxysilane, α-glycidoxypropyltrimethoxysilane, α-glycidoxypropyltriethoxysilane, β-glycidoxypropyltrimethoxysilane, β-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ
-Glycidoxypropyltriethoxysilane, γ-glycidoxypropyltripropoxysilane, γ-glycidoxypropyltributoxysilane, γ-glycidoxypropyltrimethoxyethoxysilane, γ-glycidoxypropyltriphenoxysilane, α-glycidoxybutyltrimethoxysilane, α-glycidoxybutyltriethoxysilane, β-glycidoxybutyltrimethoxysilane, β-glycidoxybutyltriethoxysilane, γ
-Glycidoxybutyltrimethoxysilane, γ-glycidoxybutyltriethoxysilane, δ-glycidoxybutyltrimethoxysilane, δ-glycidoxybutyltriethoxysilane, (3,4-epoxycyclohexyl)
Methyltrimethoxysilane, (3,4-epoxycyclohexyl) methyltriethoxysilane, β- (3,4-
Epoxycyclohexyl) ethyltrimethoxysilane,
β- (3,4-epoxycyclohexyl) ethyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltripropoxysilane, β- (3,4-epoxycyclohexyl) ethyltributoxysilane, β-
(3,4-epoxycyclohexyl) ethyltrimethoxyethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxyethoxysilane, β- (3,3
4-epoxycyclohexyl) ethyltriphenoxysilane, γ- (3,4-epoxycyclohexyl) propyltrimethoxysilane, γ- (3,4-epoxycyclohexyl) propyltriethoxysilane, δ- (3,4
-Epoxycyclohexyl) butyltrimethoxysilane, delta- (3,4-epoxycyclohexyl) butyltriethoxysilane and other trialkoxysilanes, triacyloxysilanes, or triphenoxysilanes or their hydrolysates and dimethyldimethoxysilane, phenylmethyl Dimethoxysilane, dimethyldiethoxysilane, phenylmethyldiethoxysilane, γ-chloropropylmethyldimethoxysilane, γ-chloropropylmethyldiethoxysilane, dimethyldiacetoxysilane,
γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropylmethyldiethoxysilane,
γ-aminopropylmethyldimethoxysilane, styryltrimethoxysilane, styryltriethoxysilane, γ
-Aminopropylmethyldiethoxysilane, methylvinyldimethoxysilane, methylvinyldiethoxysilane,
Glycidoxymethylmethyldimethoxysilane, glycidoxymethylmethyldiethoxysilane, α-glycidoxyethylmethyldimethoxysilane, α-glycidoxyethylmethyldiethoxysilane, β-glycidoxyethylmethyldimethoxysilane, β- Glycidoxyethylmethyldiethoxysilane, α-glycidoxypropylmethyldimethoxysilane, α-glycidoxypropylmethyldiethoxysilane, β-glycidoxypropylmethyldimethoxysilane, β-glycidoxypropylmethyldiethoxysilane , Γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropylmethyldipropoxysilane, γ-glycidoxypropylmethyldibutoxysilane, γ-glycidoxyprosilane Methyl ethoxyethoxysilane, γ-glycidoxypropylmethyldiphenoxysilane, γ-glycidoxypropylmethyldiacetoxysilane, γ-glycidoxypropylethyldimethoxysilane, γ-glycidoxypropylethyldiethoxysilane, γ -Dialkoxysilane such as glycidoxypropylvinyldimethoxysilane, γ-glycidoxypropylvinyldiethoxysilane, γ-glycidoxypropylphenyldimethoxysilane, γ-glycidoxypropylphenyldiethoxysilane, diphenoxysilane Or diacyloxysilanes or hydrolysates thereof, bis (trichlorosilyl) methane, 1,2-bis (trichlorosilyl) ethane, 1,4-bis (trichlorosilyl) butane, 1,6-bis (trichlorosilyl) hexane 1,8-bis (trichlorosilyl) octane, 1,
2-bis (trimethoxysilyl) ethylene, 1,2-bis (triethoxysilyl) ethylene, bis (trimethoxysilyl) methane, 1,2-bis (trimethoxysilyl) ethane, 1,4-bis (trimethoxy) Silyl) butane, 1,6-bis (trimethoxysilyl) hexane,
1,8-bis (trimethoxysilyl) octane, bis (triethoxysilyl) methane, 1,2-bis (triethoxysilyl) ethane, 1,4-bis (triethoxysilyl) butane, 1,6-bis ( Triethoxysilyl) hexane, 1,8-bis (triethoxysilyl) octane, 1,1-bis (trichlorosilylmethyl) ethylene, bis (trimethoxysilyl) -1,7-octadiene, bis (triethoxysilyl)- 1,7-octadiene, bis [3- (trimethoxysilyl) propyl] tetrasulfide, bis [3- (triethoxysilyl) propyl] tetrasulfide, bis [3- (trimethoxysilyl) propyl] urea, bis [3 -(Triethoxysilyl) propyl] urea, bis [3- (trimethoxysilyl) propyl] amine, bi [3- (triethoxysilyl) propyl] amine, N, N'-bis [3- (trimethoxysilyl) propyl] ethylenediamine, N, N '
-Bis [3- (triethoxysilyl) propyl] ethylenediamine and the like.

Hydrolysis is preferred in order to lower the curing temperature of these compounds and to accelerate the curing.
The hydrolysis can be performed by mixing pure water or an acidic aqueous solution such as hydrochloric acid, acetic acid or nitric acid and stirring. It is also possible to easily control the degree of hydrolysis by adjusting the blending amount of pure water or an acidic aqueous solution. At the time of hydrolysis, it is preferable to mix pure water or an acidic aqueous solution in an amount equal to or more than 3 times the molar number of the hydrolyzable group in the compound of the general formula (I) or (II) from the viewpoint of curing acceleration. During the hydrolysis, alcohol or the like is generated, so that it can be hydrolyzed without a solvent, but for the purpose of making the hydrolysis more uniform, a compound of the general formula (I) or (II) is mixed with a solvent. It is also possible to carry out hydrolysis after this. Also, depending on the purpose, heat alcohol after hydrolysis and / or
Alternatively, it is possible to remove and use an appropriate amount under reduced pressure, and to add an appropriate solvent after that. These solvents include alcohols, esters, ethers, ketones, halogenated hydrocarbons or toluene,
Examples of the solvent include aromatic hydrocarbons such as xylene, N, N-dimethylformamide, N, N-dimethylaceamide, N-methylpyrrolidone, dimethylimidazolidinone and dimethyl sulfoxide. These solvents can be used as a mixed solvent of two or more kinds, if necessary. Further, depending on the purpose, it is possible to accelerate the hydrolysis reaction and further heat it to room temperature or higher in order to proceed the reaction such as precondensation, or to lower the hydrolysis temperature to room temperature or lower in order to suppress precondensation. It is also possible.

As described above, it is preferable to use a three-dimensional crosslinked product having an ionic group, since it is possible to increase the crosslink density and reduce only the methanol crossover without impairing the ionic conductivity. Suitable examples of the silicon compound having an ionic group suitable for such a purpose are compounds represented by the following formulas (a) to (i).

[0054]

[Chemical 21]

[In the formulas (a) to (i), Y ^{1 to} Y ⁶ are each independently an optionally substituted alkyl group, an optionally substituted aryl group, a hydroxy group or an optionally substituted group. Represents a substituent selected from a good alkoxy group, an optionally substituted acyloxy group and a halogen group, and at least one of Y ^{1 to} Y ³ is a hydroxy group,
Represents a substituent selected from an optionally substituted alkoxy group, an optionally substituted acyloxy group and a halogen group, wherein E ¹ and E ² are each independently a hydroxy group, an optionally substituted siloxy group, It represents a substituent selected from an optionally substituted alkoxy group, an optionally substituted aryloxy group and a halogen group. Among these silicon compounds having an ionic group, the compound of the formula (a) is particularly preferable in terms of the magnitude of the effect of reducing the methanol crossover, and the compound of the formula (a) is easily obtained in terms of availability and high conductivity. The compound of e) is particularly preferred.

Hydrolysis is preferable in order to lower the curing temperature of these silicon compounds having an ionic group and to accelerate the curing. For the hydrolysis, the above-mentioned hydrolysis method of the compound of the general formula (I) or (II) can be applied.

These silicon compounds having an ionic group may be used alone, but are used in combination with a silicon compound having no ionic group represented by the compounds of the above-mentioned general formula (I) or (II). You may. In that case, the weight ratio of the silicon compound having an ionic group to the silicon compound having no ionic group is 0.1 / 99.9 to 100/0.
Can be selected. However, when the ionic group is a sulfonic acid group, if the amount of the silicon compound having an ionic group is too large, the effect of reducing the methanol crossover is reduced, so the silicon compound having an ionic group and the ionic group are not included. The weight ratio of silicon compound is 0.1 / 9
9.9-50 / 50, preferably 1 / 99-30 / 70
Selected from the range of.

Further, in order to adjust the degree of polymerization, a compound having an element other than monofunctional carbon which terminates the polymerization and / or a hydrolyzate thereof may be contained. In the present invention, a polymer having an anionic group and a carbon are used. It is also possible to include components other than the three-dimensional crosslinked body having an element other than the above as a crosslinking point. Examples of such components include various polymers, various plasticizers, various solvents, and various stabilizers.
By blending various polymers, various physical properties and durability of the film can be improved. In addition, various physical properties of the film, particularly mechanical physical properties, can be improved by blending various plasticizers and solvents. The durability of the film can be improved by blending various stabilizers.

In the present invention, it is also possible to fill the membrane-shaped porous base material with the solid polymer electrolyte, and the solid polymer electrolyte thus obtained is preferable because deformation due to swelling is suppressed. The shape of the porous substrate is not particularly limited,
Examples of the porous substrate include those having a plurality of holes, but a porous substrate having a plurality of through holes independent in the thickness direction and a three-dimensional network structure is preferable.

Further, it is more preferable that the porous substrate has through-holes arranged in order in the plane direction. Here, “the through holes that are arranged in an orderly manner in the plane” means a state in which the through holes are arranged at substantially equal intervals or regularly. Specifically, when the center intervals of adjacent through holes are compared with each other, the difference between the center intervals is 10
The arrangement state is within the range of 0%. That is, since the through holes are two-dimensionally arranged on the surface of the porous substrate, the adjacent through holes exist vertically and horizontally, but the difference in the center distance between the adjacent through holes is within 100%. It is necessary to be arranged inside. It is preferably within 50%, more preferably within 30%. Even if the difference in the center distance between adjacent through holes exceeds 100%, if the arrangement is a regular arrangement in which a certain number of combinations are repeated, the center distance between the adjacent through holes in each arrangement is large. If the error is within 100%, it is preferably used.

A specific example of the porous substrate used in the present invention is the shape shown in FIG. FIG. 1 is a schematic perspective view showing an example of the solid polymer electrolyte of the present invention. The porous substrate shown in FIG. 1 has a porous portion 1 having a large number of holes in the center, and a non-porous portion 2 having no holes around the porous portion. FIG. 2 shows an enlarged schematic view of the porous portion. In the polymer solid electrolyte of the present invention, it is preferable that the pores 3 of the porous portion are arranged at regular intervals with an arrangement pitch as viewed in the plane direction as shown in FIG. L in FIG. 2 is the above-mentioned “center interval between adjacent through holes”. L is preferably in the range of 0.5 to 100 μm, and 1
The range of up to 50 μm is particularly preferred. Further, the inner diameter d of the hole is preferably in the range of 0.5 to 50 μm, particularly preferably in the range of 1 to 30 μm.

In FIG. 1, the porous portion 1 is filled with a proton conductor to exert a function as a solid polymer electrolyte. Further, by filling the holes 3 of FIG. 2 with a proton conductor, swelling is suppressed and crossover of methanol, which is a fuel, permeating from the anode to the cathode is reduced, but the holes 3 are arranged in an orderly manner. In this case, the effect of reducing the methanol crossover is further improved.

As a preferred method for producing the porous substrate used in the polymer solid electrolyte of the present invention, for example, a photolithography processing method can be applied. Conventionally,
As the porous substrate, a filter material for filtration having through holes has been used. This is usually one in which a polymer film is irradiated with ions to break polymer chains, and holes are opened by a chemical etching method using an alkaline solution or the like (track etching method). On the other hand, in the holes 3 formed by the photolithography method, the hole diameter, the shape, the space between the holes, the portions to be made porous, etc. can be arbitrarily set, and the performance of the fuel cell is improved by reducing the methanol crossover. be able to. Further, since photolithography is excellent in fine processing, it is possible to finely divide the porous portion 1 and the non-porous portion 2 and bring an excellent result in miniaturization of the fuel cell. In addition, cost reduction due to improved productivity can be achieved as compared with the conventional track etching method.

Here, a scanning electron microscope (SEM) photograph of the porous substrate prepared by the photolithography method is shown in FIG. 3, and the scanning electron microscope (SEM) of the porous substrate prepared by the conventional track etching method ( A SEM) photograph is shown in FIG. Figure 3
It is clear that the holes of the porous substrate of the photolithography method of (1) are regularly arranged at equal intervals as compared with the track etching method of FIG.

The cross-sectional shape of the holes in the porous substrate produced by the photolithography method is not particularly limited, but a circle, an ellipse, a square, a rectangle, a rhombus, a trapezoid, or the like is preferable. Among these, a circle or an ellipse is preferable from the viewpoint of easy filling of the proton conductor and suppression of swelling. There is no particular limitation on the size and spacing of the pores, ease of filling the proton conductor,
It may be appropriately determined based on the battery performance and the like.

The size of the entire porous portion of the porous substrate produced by the photolithography method may be determined according to the sizes of the electrode catalyst layer and the electrode substrate used. Also, the thickness of the porous substrate may be determined based on the required battery performance, but is usually preferably in the range of 1 to 50 μm, particularly preferably in the range of 5 to 20 μm.

The detailed method of the photolithography method used in the present invention is not particularly limited, but, for example, a photosensitive polymer is coated on a substrate, exposed by applying a photomask, and the polymer is dissolved after development. Then, a method of forming a hole and peeling it from the substrate to obtain a porous polymer film is used. The photosensitive polymer may be either a negative type or a positive type, but can be appropriately selected depending on the required hole size, hole spacing, fuel cell performance and the like. The substrate material is determined in terms of adhesion to the polymer and ease of peeling, and a silicon wafer or an aluminum plate is preferably used, but the substrate material is not particularly limited. The exposure may be either reduction exposure or equal-magnification exposure, but it may be appropriately determined depending on the size of the electrolyte to be produced, the size and shape of the holes, the interval, and the like. Further, conditions such as development, dissolution, peeling from the substrate, etc. may be appropriately selected depending on the properties of the polymer. It is also possible to apply a non-photosensitive polymer on the substrate in advance, and apply a photoresist thereon, exposing, developing, and forming voids by dissolving the polymer.

The photosensitive or non-photosensitive polymer used in the photolithography method used in the present invention includes:
Although not particularly limited, polyimide is preferably used in terms of workability by photolithography, oxidation resistance of polymer, strength and the like.

As a specific method for producing the porosity by the photolithography method using polyimide, for example, a polyamic acid solution of a precursor is applied to a substrate, the solvent is dried and removed at about 100 ° C., and then a photomask is used. After forming a hole by performing photolithography processing such as exposure, development, and alkali treatment using, a method of performing an imide ring closure reaction at about 300 ° C. or higher, and finally peeling it from the substrate to obtain a porous polyimide film is Can be mentioned. The temperature and time for solvent removal and imide ring closure reaction can be appropriately determined depending on the type of polyimide used. When peeling the polyimide film from the substrate, usually, dipping in acid is carried out, but when the substrate used is a silicon wafer, hydrofluoric acid,
Hydrochloric acid is preferably used for aluminum plates.

Here, the polyimide used in the present invention may be either negative or positive photosensitive polyimide or non-photosensitive polyimide, but the size, shape, spacing of the holes, and the thickness of the film. From the above, photosensitive polyimide is preferable, and negative photosensitive polyimide is more preferable.

In addition to the above porous substrate, a porous substrate having a three-dimensional network structure is also preferable. The “three-dimensional network structure” refers to a state in which a polymer forming the porous substrate has a three-dimensional network structure in which the polymers are three-dimensionally connected. Here, a scanning electron microscope (SEM) photograph of the porous substrate having a three-dimensional network structure preferably used in the present invention is shown in FIG.

When the porous substrate has a three-dimensional network structure, the pore size is preferably in the range of 0.05 to 5 μm, more preferably 0.1 to 1 μm. The pore diameter can be determined from an average of 20 or more, preferably 100 or more pores from a photograph of the surface with a scanning electron microscope (SEM) or the like, and usually 100 pores are measured. For example, the three-dimensional network porous substrate produced by the wet coagulation method has a wide distribution of pore diameters, and therefore it is preferable to take an average of as many pore diameters as possible, for example, 100 to 500 pores.

The porosity of the three-dimensional network structure is 10 to 95%.
It is preferably in the range of. More preferably 50-9
It is in the range of 0%. Here, the porosity is a percentage (%) obtained by subtracting the volume occupied by the polymer from the total volume of the porous base material, divided by the total volume of the porous base material.

The wet coagulation method is preferably used as the method for producing the porous substrate having the three-dimensional network structure.
Specifically, a solidified polymer having three-dimensional network micropores can be obtained by immersing a polymer solution in which a polymer is dissolved in a good solvent containing a good solvent in a solidifying solvent containing a poor solvent. When making the porous substrate into a film shape,
A porous substrate having fine porosity can be obtained by applying a polymer solution on a substrate and immersing it in a coagulating solvent before the solvent is dried and removed. Here, the dissolving solvent and the coagulating solvent can be appropriately selected depending on the polymer used, and can also be appropriately selected depending on the desired pore size, shape, and fuel cell performance, but the solvents are mutually compatible. It is necessary to melt.

Even when the porous base material produced by the wet coagulation method is used for the solid polymer electrolyte, a preferred embodiment is a shape having a porous portion in the center and a dense polymer film in the periphery as shown in FIG. Becomes For example, the following method is preferably used to form such a shape, but the shape is not limited thereto.

As the first method, there is a method in which a dense film having only the peripheral portion is prepared in advance, and then the central porous portion is prepared. The dense film is produced by applying a polymer solution on a substrate and drying it normally. The porous central portion may be cut off later, or the central portion may be uncoated by masking during coating. After that, the polymer solution is applied only to the center and is immersed in a poor solvent to perform wet coagulation.

The second method is to prepare a film of which the whole is made porous by a wet coagulation method and close the holes in the peripheral portion. A method of crushing with a press, a method of filling the hole with an aproton-conducting polymer, or the like can be used to close the hole, but the method is not limited thereto.

The polymer used for the porous substrate used in the present invention is not particularly limited, but preferably polyimide (PI), polyvinylidene fluoride (PVDF),
Polyphenylene sulfide sulfone (PPSS), polytetrafluoroethylene (PTFE), polysulfone (PS
F) and the like, or copolymers thereof, copolymers with other monomers (hexafluoropropylene-vinylidene fluoride copolymer, etc.), and blends can also be used. These polymers are preferable in view of oxidation resistance, strength, easiness of wet coagulation and the like.

When using the wet coagulation method, a polar solvent having a high dielectric constant is used as a solvent for dissolving these polymers,
As the coagulation solvent, alcohol, ether, ester,
Water or the like is used. Among them, N-
Methyl-2-pyrrolidone (NMP), dimethylformamide (DMF) and dimethylacetamide (DMAC) are preferable, and methanol, ethanol, isopropanol, water and the like are preferable as the coagulation solvent. Further, a pore-forming agent may be added to control the pore size. Fine particles and salt
A surfactant or the like is used. Further, the porous base material used in the present invention may have different shapes and sizes of pores on the front surface and the back surface. It is also a preferred embodiment that the sizes of the pores on the front surface and the back surface are different from each other in order to facilitate the filling of the proton conductor. This is expected to facilitate the filling of the proton conductor. As for the degree, it is preferable that the ratio of the front and back pore diameters d is in the range of 5: 1 to 1: 1. Furthermore, holes having different sizes and shapes may be mixed in the same plane.

The method for filling the porous substrate with the proton conductor is not particularly limited. For example, a polymer having an anionic group can be applied as a solution to a porous substrate or immersed in the solution to fill the voids. It is also preferable to use ultrasonic waves or to reduce the pressure in order to facilitate filling into the voids, and it is preferable to use these in combination during coating or dipping, because the filling efficiency is further improved.
Alternatively, a method may be performed in which a monomer that is a precursor of a polymer having an anionic group is filled in the void and then polymerized in the void, or the monomer is vaporized to perform plasma polymerization.

In the present invention, the form of the fuel cell and the method for producing the fuel cell are not particularly limited. Below side
A method of using a photolithography method for manufacturing a fuel cell having a -by-side structure will be described in detail as an example. Where side-by-side
The structure means a structure in which two or more cells each consisting of a pair of opposing electrodes are arranged in the plane direction of a single polymer solid electrolyte surface. According to this structure, the cells are connected in series by connecting the anode and cathode of two or more adjacent cells with an electron conductor penetrating the solid polymer electrolyte, so that the side-by-side structure is achieved. The cross section of the polymer solid electrolyte has a structure in which proton conducting parts and electron conducting parts are alternately present. In order to manufacture such a structure, it is preferable to use the photolithography method from the viewpoint of miniaturization and productivity.

An example of the side-by-side structure is shown in FIGS. 6 and 7. FIG. 6 is a schematic perspective view of a polymer solid electrolyte of the present invention having a side-by-side structure, and FIG. 7 is a schematic sectional view showing a part of the manufacturing process thereof. Although FIGS. 6 and 7 exemplify that two cells are arranged laterally, it is also possible to arrange three or more cells in the plane direction with the same side-by-side structure. . For the sake of simplicity, the following description will be given with two cells. In FIG. 6, in the proton conducting part, the porous part 1 is filled with a proton conductor (not shown),
In the electron conducting portion, the film conductor portion 4 is filled with an electron conductor. The non-porous portion 2 where protons and electrons do not conduct except the porous portion 1 of the proton conducting portion and the membrane conducting portion 4 of the electron conducting portion.
It is a dense polymer film. The photolithography method described in the present invention is preferably used for producing a polymer film having such a complicated and fine structure. The porous substrate shown in FIG. 6 is produced by the photolithography method, and this is used as a polymer solid electrolyte by the method illustrated in FIG. 7. In FIG. 7, the transmembrane electron conducting portion is filled with the electron conductor in advance, and then the proton conducting portion is filled with the proton conductor, but the order may be reversed. Alternatively, a proton conductor may be filled to form a proton conducting portion, an electrode may be provided next, and finally an electron conducting portion may be formed.

The electron conducting part of the side-by-side structure described above is
The structure penetrates the electrolyte membrane. Here, a portion that penetrates the electrolyte membrane as an electron conducting portion is referred to as a membrane conducting portion. This membrane conductive portion has a function different from that of the porous portion for filling the proton conductor. The size and shape of the membrane conductive portion are not particularly limited. The larger the membrane conductive portion, the lower the electrical resistance between cells and the expected voltage improvement in series. However, the larger the membrane conductive part, the higher the possibility that hydrogen or organic solvent such as methanol on the anode side leaks to the cathode side, or the air on the cathode side leaks to the anode side, which may cause performance degradation. is there. Therefore, it is preferable to determine the size and shape of the film conductive portion in consideration of the electric resistance and leak resistance of the electron conductor used for the electron conductive portion. The electron conducting portion may not pass through the solid polymer electrolyte but may pass through the outside.

The electron conductor of the film conductive portion 4 is not particularly limited, but a conductive paste is preferably used. As the conductive paste, those in which a conductive agent such as carbon, silver, nickel, copper, platinum and palladium is dispersed in a polymer can be preferably used, and both reduction of electronic resistance and improvement of leak resistance can be achieved. Especially DMFC
In this case, it is important to prevent leakage of methanol, and in addition to general-purpose conductive paste in which carbon or silver is dispersed in silicone resin, polyester, epoxy resin, etc., conductive in which carbon black, silver, platinum, etc. are dispersed in PVDF or polyimide. A paste is also preferably used. Electronic conduction part
Although 5 is electrically connected to the electrode base material or the electrode catalyst layer of the cell, a conductive paste is preferably used also for reducing the contact resistance.

As the electron conducting portion 5, a metal foil or metal wire made of nickel, stainless steel, aluminum, copper or the like may be used. It is also possible to combine these metal foils or wires with a conductive paste.

The solid polymer electrolyte of the present invention is a membrane in combination with an electrode 7 composed of an electrode base material and an electrode catalyst layer.
Used as an electrode composite (MEA) in polymer electrolyte fuel cells.

The electrode catalyst layer of the electrode 7 in the polymer electrolyte fuel cell of the present invention is not particularly limited, and known ones can be used. The electrode catalyst layer is a layer containing a catalyst necessary for an electrode reaction and an electrode active material (which means a substance that oxidizes or reduces), and further a substance which contributes to electron conduction or ion conduction that promotes the electrode reaction. Further, when the electrode active material is a liquid or a gas, it is necessary to have a structure that allows the liquid or the gas to easily permeate therethrough, and a structure that promotes the discharge of the substance generated by the electrode reaction is also necessary.

In the polymer electrolyte fuel cell of the present invention,
Preferable examples of the electrode active material include organic solvents such as hydrogen and methanol, oxygen and the like, and preferable examples of the catalyst include noble metal particles such as platinum. Further, it is preferable to include a material for improving the conductivity of the electrode catalyst layer,
The form is not particularly limited, but for example, it is preferable to have conductive particles. Examples of the conductive particles include carbon black and the like. Particularly, carbon supported on a catalyst such as platinum-supported carbon is preferably used. The electrode catalyst layer is required to have a structure in which a catalyst, an electron conductor (for example, carbon black), and an ionic conductor (for example, a proton exchange resin) are in contact with each other so that an electrode active material and a reaction product can efficiently go in and out. Further, the polymer compound is effective for improving the ionic conductivity, improving the binding property of the material, and enhancing the water repellency. Therefore, it is preferable that the electrode catalyst layer contains at least catalyst particles, conductive particles, and a polymer compound.

In the polymer electrolyte fuel cell of the present invention, a known catalyst can be used as the catalyst contained in the electrode catalyst layer, and the catalyst is not particularly limited, but platinum, palladium, ruthenium, iridium, A noble metal catalyst such as gold is preferably used. Further, two or more kinds of elements such as alloys and mixtures of these noble metal catalysts may be contained.

The electron conductor (conductive material) contained in the electrode catalyst layer is not particularly limited, but an inorganic conductive substance is preferably used in terms of electron conductivity and touch resistance. Among these, carbon black, carbonaceous materials such as graphite and carbonaceous materials, and metals and semimetals can be mentioned. here,
As the carbon material, carbon black such as channel black, thermal black, furnace black, and acetylene black is preferably used because of its electron conductivity and large specific surface area. Furnace blacks include Cabot's Vulcan XC-72, Vulcan P, Black Pearls 880, Black Pearls 1100, Black Pearls 1300, Black Pearls 2000, Regal 400, Ketjen Black EC made by Ketjen Black International, Mitsubishi Chemical Corp. Made # 315
No. 0, # 3250 and the like, and examples of acetylene black include Denka Black manufactured by Denki Kagaku Kogyo. In addition to carbon black, artificial graphite and carbon obtained from organic compounds such as natural graphite, pitch, coke, polyacrylonitrile, phenol resin and furan resin can also be used. The form of these carbon materials is not particularly limited, and in addition to particulate form, fibrous form can be used. It is also possible to use a carbon material obtained by post-processing these carbon materials. Among such carbon materials, especially Vulcan XC manufactured by Cabot
-72 is preferably used from the viewpoint of electronic conductivity.

The addition amount of these electron conductors should be appropriately determined according to the required electrode characteristics, the specific surface area of the substance used, the electronic resistance, etc., but the weight ratio in the electrode catalyst layer is 1 A range of up to 80% is preferred,
The range of 20 to 60% is more preferable. The electron conductor is
When the amount is small, the electron resistance becomes high, and when the amount is large, the gas permeability is impaired and the catalyst utilization rate is decreased, which all deteriorate the electrode performance.

From the viewpoint of electrode performance, it is preferable that the electron conductor is uniformly dispersed with the catalyst particles. Therefore, it is preferable that the catalyst particles and the electron conductor are well dispersed in advance as a coating liquid.

It is also a preferred embodiment to use a catalyst-carrying carbon in which a catalyst and an electron conductor are integrated as the electrode catalyst layer. By using this catalyst-supporting carbon, the utilization efficiency of the catalyst is improved, which can contribute to cost reduction. Here, even when the catalyst-supporting carbon is used for the electrode catalyst layer, it is possible to further add a conductive agent. As such a conductive agent, the above-mentioned carbon black is preferably used.

As the ion conductor used in the electrode catalyst layer, known ones can be used. As the ion conductor, generally, various organic and inorganic materials are known, but when used in a fuel cell, an ion such as a sulfonic acid group, a carboxylic acid group or a phosphoric acid group which improves proton conductivity is used. Polymers having exchange groups are preferably used.
Among them, a polymer having a proton exchange group composed of a fluoroalkyl ether side chain and a fluoroalkyl main chain is preferably used. For example, DuPont's Nafion, Asahi Kasei's Aciplex, Asahi Glass' Flemion, etc. are preferably used. These ion exchange polymers are provided in the electrode catalyst layer in the state of solution or dispersion. At this time, the solvent that dissolves or disperses the polymer is not particularly limited, but a polar solvent is preferable from the viewpoint of the solubility of the ion exchange polymer.

The ionic conductor should be added in advance to the coating liquid containing the electrode catalyst particles and the electron conductor as the main constituents when the electrode catalyst layer is prepared, and the ionic conductor should be applied in a state of being uniformly dispersed. Although preferable from the point of view, the ionic conductor may be applied after applying the electrode catalyst layer.
Here, the method of applying the ionic conductor to the electrode catalyst layer includes spray coating, brush coating, dip coating, die coating, curtain coating, flow coating and the like, and is not particularly limited.

The amount of the ionic conductor contained in the electrode catalyst layer should be appropriately determined according to the required electrode characteristics and the electric conductivity of the ionic conductor used.
Although not particularly limited, the range of 1 to 80% by weight is preferable, and the range of 5 to 50% is more preferable.
The ionic conductor has a low ionic conductivity when it is too small, and when it is too large, it impairs the gas permeability, and thus may deteriorate the electrode performance.

The electrode catalyst layer may contain various substances in addition to the above-mentioned catalyst, electron conductor and ionic conductor. In particular, in order to enhance the binding property of the substance contained in the electrode catalyst layer, it is preferable to contain a polymer other than the above-mentioned proton exchange resin. Examples of such a polymer include a polymer containing a fluorine atom, and are not particularly limited. For example, polyvinyl fluoride (PVF), polyvinylidene fluoride (PVDF), polyhexafluoropropylene (FEP), poly Tetrafluoroethylene,
Polyperfluoroalkyl vinyl ether (PFA) and the like, or copolymers thereof, copolymers of monomer units constituting these polymers and other monomers such as ethylene and styrene, and blends can also be used. . The content of these polymers in the electrode catalyst layer is preferably in the range of 5 to 40% by weight. If the polymer content is too high, the electron and ionic resistance increases and the electrode performance tends to deteriorate.

In the electrode catalyst layer, it is also a preferred embodiment that the catalyst-polymer composite has a three-dimensional network structure. The catalyst-polymer composite is a polymer composite containing catalyst particles, and this composite has a three-dimensional network structure. That is, the catalyst-polymer composite has a three-dimensional network structure in which the catalyst-polymer composite is three-dimensionally connected.

When the electrode catalyst layer has a three-dimensional network structure, its pore size is preferably in the range of 0.05 to 5 μm, more preferably 0.1 to 1 μm. The pore diameter can be determined from an average of 20 or more, preferably 100 or more, from a photograph of the surface with a scanning electron microscope (SEM) or the like, and usually 100 is measured. Since the porous electrode catalyst layer produced by the wet coagulation method has a wide distribution of pore diameters, it is preferable to take as many pore diameters as possible, preferably the average of 100 to 500 pore diameters.

The porosity of the three-dimensional network structure of the electrode catalyst layer is
It is preferably in the range of 10 to 95%. The range is more preferably 50 to 90%. Here, the porosity is
It is a percentage (%) obtained by subtracting the volume occupied by the catalyst-polymer composite from the total volume of the electrode catalyst layer, divided by the total volume of the electrode catalyst layer.

In order to produce an electrode catalyst layer having a three-dimensional network structure, usually, the catalyst layer is applied to an electrode base material, a proton exchange membrane and other base materials, and then wet coagulation is performed. When it is difficult to determine the porosity of the electrode catalyst layer alone, the porosities of the electrode base material, the proton exchange membrane, and the other base materials are determined in advance, and the base material and the electrode catalyst layer are included. It is also possible to determine the porosity of the electrode catalyst layer alone after determining the porosity.

The electrode catalyst layer having a three-dimensional network structure has a large porosity, good gas diffusibility and discharge of generated water,
Moreover, electron conductivity and proton conductivity are also good. In the conventional porosification, the catalyst particle size and the particle size of the added polymer are increased, and pores are formed by using a pore-forming agent. The contact resistance between the proton exchange resins becomes higher than that of the electrode catalyst layer. On the other hand, in the three-dimensional network structure by the wet coagulation method, the polymer composite containing the catalyst-supporting carbon has a three-dimensional network structure, so that electrons and protons are easily conducted through this polymer composite, and the microporous structure The quality structure is preferable because it has a good gas diffusibility and discharge of generated water.

Even when the electrode catalyst layer has a three-dimensional network structure, the same substances as those used in the past can be used as the substance used for the catalyst, the electron conductor and the ionic conductor. However, when an electrode catalyst layer having a three-dimensional network structure is produced, it is preferable to use a wet coagulation method, and therefore it is preferable to select a polymer suitable for this wet coagulation method.
Polymers in which the catalyst particles are well dispersed and which do not deteriorate in the oxidation-reduction atmosphere in the fuel cell are preferable. Examples of such a polymer include a polymer containing a fluorine atom, and are not particularly limited. For example, polyvinyl fluoride (PVF), polyvinylidene fluoride (PVDF), polyhexafluoropropylene (FEP), poly Perfluoroalkyl vinyl ether (PFA) or the like, or copolymers thereof, copolymers of monomer units constituting these polymers and other monomers such as ethylene and styrene (eg, hexafluoropropylene-vinylidene fluoride copolymer). Combined) and blends can be preferably used.

Among these, polyvinylidene fluoride (PV
DF), a hexafluoropropylene-vinylidene fluoride copolymer is a catalyst-polymer having a three-dimensional network structure by a wet coagulation method using an aprotic polar solvent as a dissolving solvent and a protic polar solvent or the like as a coagulating solvent. It is a particularly preferred polymer in that a composite is obtained.

Specific examples of the polymer solvent include N-
Methylpyrrolidone (NMP), dimethylformamide (DMF), dimethylacetamide (DMAC), propylene carbonate (PC), dimethylimidazolidinone (DMI) and the like can be mentioned.
In addition to lower alcohols such as methanol, ethanol, and isopropanol, esters such as ethyl acetate and butyl acetate, and various aromatic or halogen-based organic solvents can be mentioned.

As the polymer of the catalyst-polymer composite, in addition to the above-mentioned polymers, a polymer having a proton exchange group for improving the proton conductivity is also preferable. Examples of the proton exchange group contained in such a polymer include a sulfonic acid group, a carboxylic acid group, and a phosphoric acid group, but are not particularly limited. Further, a polymer containing such a proton exchange group in the skeleton is also used without particular limitation. For example, a polymer having a proton exchange group composed of a fluoroalkyl ether side chain and a fluoroalkyl main chain is preferably used. Specifically, it is Nafion manufactured by DuPont. Further, a polymer containing the above-mentioned fluorine atom having a proton exchange group,
Other polymers such as ethylene and styrene, copolymers and blends thereof may be used.

When Nafion is used, a commercially available Nafion membrane may be dissolved in an aprotic polar solvent.
Commercially available from uPont, IonPower, etc.,
Water-methanol-isopropanol, water-ethanol-i
It is also possible to use a Nafion solution of a lower alcohol-containing mixed solvent such as so-propanol and water-ethanol-n-propanol. In addition, these Nafion solutions may be concentrated or solvent-substituted. In this case, the coagulation solvent at the time of wet coagulation should be appropriately determined depending on the solvent species of the Nafion solution, but when the solvent of the Nafion solution is an aprotic polar solvent, water or alcohol is used as the coagulation solvent. In addition to compounds and esters, various organic solvents and the like are preferable. In the case of a lower alcohol solvent such as a water-methanol-isopropanol mixed solvent, esters such as butyl acetate and various organic solvents are preferably used.

As the polymer used in the catalyst-polymer composite, it is also preferable to use the above-mentioned polymer containing a fluorine atom or a polymer containing a proton exchange membrane by copolymerization or blending. In particular, blending polyvinylidene fluoride, poly (hexafluoropropylene-vinylidene fluoride) copolymer, etc. with a polymer such as Nafion having a fluoroalkyl ether side chain and a fluoroalkyl main chain in the proton exchange group will improve the electrode performance. It is preferable from the point of view.

The main components of the catalyst-polymer composite are the catalyst-supporting carbon and the polymer, the ratio of which should be appropriately determined according to the required electrode characteristics and is not particularly limited. A carbon / polymer weight ratio of 5/95 to 95/5 is preferably used. In particular, when it is used as an electrode catalyst layer for polymer electrolyte fuel cells, the catalyst supporting carbon / polymer weight ratio is 40/60.
~ 85/15 is preferable.

Various additives may be added to the catalyst-polymer composite. For example, there are conductive agents such as carbon for improving the electronic conductivity, polymers for improving the binding property, additives for controlling the pore size of the three-dimensional network structure, etc. it can. The addition amount of these additives is preferably in the range of 0.1 to 50% as a weight ratio with respect to the catalyst-polymer composite, and 1 to 20.
The range of% is more preferable.

As a method for producing a catalyst-polymer composite having a three-dimensional network structure, a wet coagulation method is preferable. Here, after coating the catalyst-polymer solution composition, this coating layer can be brought into contact with a coagulation solvent for the polymer to coagulate and deposit the catalyst-polymer solution composition and perform solvent extraction at the same time. This catalyst-polymer solution composition is one in which catalyst-supporting carbon is uniformly dispersed in a polymer solution. As the catalyst-carrying carbon and polymer, those mentioned above are preferably used. The solvent for dissolving the polymer should be appropriately determined according to the polymer used and is not particularly limited. It is important that the polymer solution well disperses the catalyst-supporting carbon. If the dispersed state is poor, the catalyst-carrying carbon and the polymer cannot form a complex during the wet solidification, which is not preferable.

Regarding the coating method of the catalyst-polymer solution composition, the coating method is selected according to the viscosity and solid content of the catalyst-polymer solution composition and is not particularly limited, but a knife coater, a bar coater A general coating method such as a spray, dip coater, spin coater, roll coater, die coater or curtain coater is used.

The coagulation solvent for wet coagulating the polymer is not particularly limited, but a solvent which is likely to coagulate and precipitate the polymer used and which is compatible with the solvent of the polymer solution is preferable. The method of contacting the base material with the coagulating solvent is not particularly limited, either, but the base material is immersed in the coagulating solvent, the coating layer alone is contacted with the liquid surface of the coagulating solvent, and the coagulating solvent is applied to the coating layer as a shower. A method such as ringing or spraying can be used.

With respect to the base material to which the catalyst-polymer solution composition is applied, either the electrode base material or the polymer solid electrolyte can be subjected to wet coagulation after application. Also, after applying to an electrode base material or a base material other than the polymer electrolyte (for example, a transfer base material) and then performing wet coagulation to form a three-dimensional network structure, this electrode catalyst layer is applied to the electrode base material or the polymer. The solid electrolyte may be transferred or sandwiched. As the transfer substrate in this case, a sheet of polytetrafluoroethylene (PTFE), or a glass plate or a metal plate whose surface is treated with a release agent of fluorine or silicone is used.

In the polymer electrolyte fuel cell of the present invention, the electrode base material is not particularly limited and known ones can be used. Further, the electrode base material may not be used in order to save space.

The electrode base material used in the present invention is not particularly limited as long as it has a low electric resistance and can collect (supply) electricity. Examples of the constituent material of the electrode substrate include, for example, those mainly composed of a conductive inorganic substance, and as the conductive inorganic substance, a fired body from polyacrylonitrile, a fired body from pitch,
Carbon materials such as graphite and expanded graphite, stainless steel,
Examples include molybdenum and titanium.

The form of the conductive inorganic substance of the electrode base material is not particularly limited, and for example, it is used in the form of fibers or particles, but from the viewpoint of gas permeability, the fibrous conductive inorganic substance (inorganic conductive fiber), particularly Carbon fibers are preferred. As the electrode base material using the inorganic conductive fiber, either a woven fabric or a non-woven fabric structure can be used. For example, carbon paper TGP series, SO series, E-TE manufactured by Toray Industries, Inc.
For example, carbon cloth manufactured by K Co. is used. As the woven fabric, a plain weave, a twill weave, a satin weave, a pattern weave, a binding weave and the like can be used without particular limitation. Further, as the non-woven fabric, those made by a paper making method, a needle punch method, a spun bond method, a water jet punch method, a melt blow method, etc. are used without any particular limitation. It may be a knitted material. In these fabrics, particularly when carbon fibers are used, a plain woven fabric using flame-resistant spun yarn is carbonized or graphitized, and the flame-resistant yarn is carbonized after being processed into a nonwoven fabric by a needle punch method, a water jet punch method, or the like. Alternatively, a graphitized non-woven fabric, a mat non-woven fabric produced by a papermaking method using a flame resistant yarn, a carbonized yarn, or a graphitized yarn is preferably used. In particular, it is preferable to use a non-woven fabric because a thin and strong fabric can be obtained.

When an inorganic conductive fiber made of carbon fiber is used as the electrode base material, examples of the carbon fiber include polyacrylonitrile (PAN) type carbon fiber, phenol type carbon fiber, pitch type carbon fiber and rayon type carbon fiber. It is illustrated. Among them, PAN-based carbon fiber is preferable. This is because, in general, PAN-based carbon fibers have higher compressive strength and tensile elongation at break than pitch-based carbon fibers, and are less likely to break. In order to obtain carbon fibers that are difficult to break, the carbonization temperature of the carbon fibers is preferably 2,500 ° C or lower, more preferably 2,000 ° C or lower.

The electrode base material used in the polymer electrolyte fuel cell of the present invention has a water-repellent treatment for preventing deterioration of gas diffusion / permeability due to retention of water, and a partial portion for forming a water discharge passage. Water-repellent and hydrophilic treatments and addition of carbon powder for reducing resistance are also preferable embodiments.

The polymer electrolyte fuel cell of the present invention is side-by-
In the case of having a side structure, it is also a preferred embodiment to provide a diffusion layer in order to promote the inflow of fuel or air such as hydrogen or methanol aqueous solution and the discharge of products such as water or carbon dioxide. The above-mentioned electrode base material also plays a role in such a diffusion layer, but it is more preferable to use a non-conductive cloth as the diffusion layer. Here, the constituent material of the non-conductive cloth is not particularly limited as long as it is a non-conductive fiber, for example.

Examples of the non-conductive fibers constituting the non-conductive cloth of the diffusion layer include polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoroethylene copolymer (FEP), tetrafluoroethylene-perfluoroalkyl. Vinyl ether copolymer (P
FA), tetrafluoroethylene-ethylene copolymer (ETFE), polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), polychlorotrifluoroethylene (CTFE), chlorinated polyethylene, flame-resistant polyacrylonitrile, polyacrylonitrile, Polyester, polyamide, polyethylene, polypropylene and the like can be used. Among these non-conductive fibers, PT
FE, FEP, PFA, ETFE, PVDF, PVF,
Fibers made of fluorine atom-containing polymers such as CTFE
It is preferable from the viewpoint of corrosion resistance during electrode reaction.

As the non-conductive cloth for the diffusion layer, either woven or non-woven structure can be used. As the woven fabric, a plain weave, a twill weave, a satin weave, a pattern weave, a binding weave and the like can be used without particular limitation. Further, as the non-woven fabric, a paper making method, a needle punching method, a spunbonding method, a water jet punching method, a melt blow method and the like can be used without particular limitation. It may be a knitted material.
Among these cloths, a plain woven fabric, a non-woven fabric by a needle punching method or a water jet punching method, a mat non-woven fabric by a paper making method, and the like are preferably used. A non-woven fabric is preferably used from the viewpoint that a fabric that is porous, thin, and strong can be obtained.

The non-conductive cloth of the diffusion layer is subjected to a water repellent treatment for preventing gas diffusion / permeability deterioration due to water retention, a partial water repellent treatment for forming a water discharge passage or a hydrophilic treatment. That is also a preferred embodiment. Furthermore, it is also a preferred embodiment to carry out post-treatments such as heat treatment, stretching and pressing. By these post-treatments, effects such as thinning, increase in porosity and increase in strength can be expected.

In the polymer electrolyte fuel cell of the present invention, it is preferable to provide a conductive intermediate layer containing at least an inorganic conductive substance and a hydrophobic polymer between the electrode base material and the electrode catalyst layer. In particular, when the electrode base material is a carbon fiber woven fabric or a non-woven fabric having a high porosity, by providing the conductive intermediate layer, it is possible to suppress the performance deterioration due to the electrode catalyst layer soaking into the electrode base material.

The solid polymer electrolyte of the present invention can be used, for example, in a membrane.
-When it is used for an electrode composite (MEA), it is preferable to make MEA after post-processing into a polymer solid electrolyte. For example, in order to further reduce the permeation of fuel methanol, it is also a preferred embodiment to coat the polymer thin film with a metal thin film. Examples of such a metal thin film include palladium, platinum, silver and the like.

[0126] In the polymer solid electrolyte of the present invention, the method for producing the membrane-electrode composite (MEA) using the electrode catalyst layer or the electrode catalyst layer and the electrode base material is not particularly limited. It is preferable to integrate them by hot pressing, but the temperature and pressure are set to the thickness of the polymer solid electrolyte,
It may be appropriately selected depending on the porosity, the electrode catalyst layer and the electrode base material. Normally, the temperature is 40 ℃ -180 ℃, the pressure is 10kgf / cm2-80k
gf / cm2 is preferred.

The polymer solid electrolyte of the present invention can be applied to various electrochemical devices. For example, a fuel cell, a water electrolyzer, a chloroalkali electrolyzer, etc. may be mentioned, but among them, a fuel cell is most preferable. Further, among the fuel cells, it is suitable for polymer electrolyte fuel cells, and there are ones that use hydrogen as a fuel and ones that use an organic solvent such as methanol as a fuel. It is particularly preferably used in a DMFC using as a fuel.

Further, the application of the polymer electrolyte fuel cell of the present invention is not particularly limited, but a power supply source of a moving body is preferable. Especially mobile phones, personal computers,
Portable devices such as PDAs, home appliances such as vacuum cleaners, passenger cars, buses,
It is preferably used as a power supply source for automobiles such as trucks, ships, and moving bodies such as railways.

[0129]

EXAMPLES The present invention will be described below with reference to examples.

Comparative Example 1 (1) Pretreatment of Polymer Solid Electrolyte Commercially available polymer solid electrolyte "Nafion 117 (Du '
(Manufactured by Pont)) was treated with hot water at 95 ° C. for 1 hour. (2) Performance of polymer solid electrolyte The methanol permeation amount and ionic conductivity of the membrane pretreated in (1) were evaluated. The membrane was set in an Electrochem cell and 0.2 mol of 1 mol / l aqueous methanol solution was applied to one side.
Supply at 1 / min, 50ml / mi of air on the other side
n. The amount of permeated methanol was determined by measuring the concentration of methanol in the exhausted air.

The ionic conductivity of the membrane was measured by Hokuto Denko's electrochemical measurement system HAG5010 (HZ-3000 50V 10A Power).
Unit, HZ-3000 Automatic Polarization System) and frequency response analyzer (Freq) manufactured by NF Circuit Design Block
uency Response Analyzer) 5010 was used to measure the constant potential impedance by the two-terminal method, and the ionic conductivity was determined from the Nykist diagram. The AC amplitude was 500 mV. As the sample, a film having a width of about 10 mm and a length of about 10 to 30 mm was used. The sample used was immersed in water until just before measurement. Platinum wire (2 pieces) with a diameter of 100 μm as an electrode
It was used. The electrodes were arranged on the front side and the back side of the sample film so as to be parallel to each other and orthogonal to the longitudinal direction of the sample film.

The amount of methanol permeated through this membrane was 2.0 μmo.
It was 1 / cm ² / min and the ionic conductivity was 5.0 S / cm ² .

Example 1 (1) Hydrolysis of a three-dimensional crosslinkable compound having an element other than carbon as a crosslinking point A 0.01N hydrochloric acid aqueous solution was added to 5 g of tetrabutoxy titanium manufactured by Toray Dow Corning Silicone Co., Ltd.
After stirring for a minute, a colorless transparent hydrolyzate was obtained. (2) Preparation of polymer solid electrolyte Commercially available 20% Nafion solution (manufactured by Du'Pont)
0.22 g of the hydrolyzate produced in (1) was added to 10 g. This solution was heated at 100 ° C. for 30 minutes to obtain a polymer solid electrolyte. (3) Performance of Polymer Solid Electrolyte The membrane obtained in (2) was evaluated for methanol permeation amount and ionic conductivity in the same manner as in Comparative Example 1. The membrane had a methanol permeation rate of 1.5 μmol / cm ² / min and an ionic conductivity of 4.8 S / cm ² .

Example 2 (1) Preparation of Polymer Solid Electrolyte and Evaluation of Membrane Performance In Example 1, a commercially available 20% Nafion solution (D
A solid polymer electrolyte was produced in the same manner as in Example 1 except that the amount of the hydrolyzate added to 10 g of u'Pont) was changed to 0.5 g. When the performance of this membrane was evaluated in the same manner as in Comparative Example 1, the methanol permeation amount was 1.0 μmol.
/ Cm ² / min, the ionic conductivity was 4.5 S / cm ² .

Example 3 (1) Preparation of solid polymer electrolyte and evaluation of membrane performance A solid polymer electrolyte was prepared in the same manner as in Example 2 except that tetramethoxysilane was used instead of tetrabutoxytitanium. When the performance of this membrane was evaluated in the same manner as in Comparative Example 1, the permeation amount of methanol was 1.0 μmol / cm ² / m.
in, ionic conductivity was 4.0 S / cm ² .

Example 4 (1) Preparation of Polymer Solid Electrolyte and Evaluation of Membrane Performance Similar to Example 2 except that a 1: 1 solution of phenyltrimethoxysilane and diphenyltrimethoxysilane was used in place of tetrabutoxytitanium. To prepare a polymer solid electrolyte. When the performance of this membrane was evaluated in the same manner as in Comparative Example 1, the permeation amount of methanol was 1.5 μmol / cm ² / mi.
n, ionic conductivity was 4.7 S / cm ² .

Example 5 (1) Preparation of solid polymer electrolyte and evaluation of membrane performance A 20% sulfonated polyphenylene sulfide sulfone solution was used in place of the Nafion solution, and the porosity was 10%.
%, A polymer solid electrolyte was prepared in the same manner as in Example 2 except that the polyimide base material prepared by photolithography having a pore diameter of 12 μm was filled with the polymer solid electrolyte.

Example 6 (1) Preparation of solid polymer electrolyte and evaluation of membrane performance A 20% solution of polyphenylene sulfide sulfone having a phosphonic acid group was used instead of the Nafion solution, and methoxyaluminum was used instead of phenyltrimethoxysilane. A polymer solid electrolyte was obtained in the same manner as in Example 4 except that it was used.

Example 7 (1) Preparation of Polymer Solid Electrolyte and Evaluation of Membrane Performance A 20% solution of polydiphenoxyphosphazene having a phosphoric acid group was used in place of the Nafion solution, and triphenylmethoxysilane was used in place of phenyltrimethoxysilane. A polymer solid electrolyte was obtained in the same manner as in Example 4 except that methoxyboron was used. Example 8 (1) Preparation of solid polymer electrolyte, evaluation of membrane performance 20% having carboxy group instead of Nafion solution
A polymer solid electrolyte was obtained in the same manner as in Example 4 except that a polyimide solution was used and tetramethoxyzirconium was used instead of phenyltrimethoxysilane. Example 9 (1) Preparation of polymer solid electrolyte, evaluation of membrane performance Triethoxyphosphorus was used instead of phenyltrimethoxysilane, and the porosity was 10%, the surface pore diameter was 1 μm, and the PVDF porous group had a three-dimensional network structure. A polymer solid electrolyte was obtained in the same manner as in Example 4 except that the material was filled with the polymer solid electrolyte.

Example 10 (1) Preparation of solid polymer electrolyte and evaluation of membrane performance In the same manner as in Example 2 except that tetraisopropylbis (3-trimethoxysilylpropyl) methanebisphosphonate was used instead of tetrabutoxytitanium. A polymer solid electrolyte was obtained.

Example 11 (1) Preparation of polymer solid electrolyte and evaluation of membrane performance As Example 10 except that the addition amount of the hydrolyzate of tetraisopropylbis (3-trimethoxysilylpropyl) methanebisphosphonate was 3 g. A polymer solid electrolyte was obtained in the same manner.

The polymer solid electrolytes produced in Examples 5 to 11 were all superior to Comparative Example 1.
In addition, when a fuel cell was produced using the polymer solid electrolytes produced in Examples 1 to 11 and evaluated, the cell performance was superior to that obtained when the polymer electrolyte of Comparative Example 1 was used.

Example 12 (1) Synthesis of sulfonated polyphenylene oxide Polyphenylene oxide (YPX-100L) manufactured by Mitsubishi Engineering Plastics Co., Ltd. at room temperature under a nitrogen atmosphere.
(100 g) was dissolved in chloroform (1000 g), and chlorosulfonic acid (34 mL) was slowly added dropwise with stirring. After completion of dropping, stirring was continued at room temperature for 30 minutes. The precipitated polymer was separated by filtration, pulverized with a mill, thoroughly washed with water, and vacuum dried to obtain the desired sulfonated polyphenylene oxide. (Ion exchange equivalent: 3.0 me
q) The sulfonated polyphenylene oxide was dissolved in N, N-dimethylacetamide (DMAc) to give a 20 wt% solution. (2) Synthesis of trimethylsilyl 4-pentenoate 2 equipped with reflux condenser, stirrer and nitrogen gas inlet tube
4-Pentenoic acid (Tokyo Kasei Kogyo Co., Ltd., 48.48 g) was placed in a 00 mL three-necked flask. The flask was immersed in an ice bath, nitrogen gas was introduced, and hexamethyldisilazane (39.08 g, 0.242 mol) was added dropwise with stirring. White crystals were deposited and the whole became sherbet-like. Stir,
While introducing nitrogen gas and expelling ammonia gas,
The reaction was carried out at 100 ° C for about 6 hours. The crystals in the reaction solution were dissolved to give a colorless transparent solution. Purification was performed by distillation under reduced pressure to obtain trimethylsilyl 4-pentenoate (70.9 g) as a colorless transparent liquid. (Gas chromatographic purity 96.8%) (3) Synthesis of trimethylsilyl 5-trimethoxysilylpentanoate Trimethoxysilane (Tokyo Kasei Kogyo, 35.50 in a 300 mL three-necked flask equipped with a dropping funnel and a stirring blade.
g) was added. Further, a solution prepared by dissolving chloroplatinic acid hexahydrate (Wako Pure Chemical Industries, Ltd., 7.3 mg) in 2-propanol (0.2 mL) was added. Trimethylsilyl 4-pentenoate (50.06 g) was placed in the dropping funnel and added dropwise with stirring at room temperature. Since heat generation was observed during the process, the three-necked flask was immersed in an ice bath and cooled. The flask was returned to room temperature again and left overnight. Purified by vacuum distillation, trimethylsilyl 5-trimethoxysilylpentanoate (32.2
g) was obtained as a colorless transparent liquid. (Gas chroma purity 96.
8%) (4) Hydrolysis of three-dimensional crosslinkable compound having an element other than carbon as a crosslinking point (4a) 1,6-bis (trimethoxysilyl) hexane (1.35 g) manufactured by Gelest Co. at 1C at 0 ° C. Hydrochloric acid (0.
68 g) was added and stirred at room temperature for 30 minutes to obtain a colorless and transparent hydrolyzate.

(4b) Trimethylsilyl 5-trimethoxysilylpentanoate (1.0 g) obtained in the above (3) was added at 0 ° C.
1M hydrochloric acid (0.37 g) was added thereto, and the mixture was stirred at room temperature for 30 minutes to obtain a colorless transparent hydrolyzate. (5) Preparation of polymer solid electrolyte membrane Hydrolyzate of (4a) and (4b) and sulfonated polyphenylene oxide DMAc solution of (1) (19.
5 g) were mixed. Cast this solution on a glass plate,
The polymer solid electrolyte membrane was produced by heating at 100 ° C. for 3 hours. The film thickness was 180 μm. (6) Performance Evaluation of Polymer Solid Electrolyte Membrane The membrane obtained in (5) above was evaluated for methanol permeation amount and ionic conductivity in the same manner as in Comparative Example 1. The amount of methanol permeated through this membrane was 1.3 μmol / cm ² · min,
Compared to Comparative Example 1, methanol crossover was suppressed. The ionic conductivity was 4.7 S / cm ² , which was about the same as in Comparative Example 1.

Example 13 (1) Synthesis of trimethylsilyl 3-butenoate 2 equipped with a reflux condenser, a stirrer and a nitrogen gas inlet tube
3-Butenoic acid (Aldrich, 50.0 g) was placed in a 00 mL three-necked flask. The flask was immersed in an ice bath, nitrogen gas was introduced, and hexamethyldisilazane (4
6.9 g) was added dropwise. White crystals were deposited and the whole became sherbet-like. The reaction was carried out at 100 ° C. for about 5 hours while stirring and introducing nitrogen gas and expelling ammonia gas. Most of the crystals in the reaction solution were dissolved and turned into a slightly brown transparent solution. Purification was carried out by vacuum distillation. Since some white crystals were found to be mixed in the distillate, they were removed by pressure filtration (PTFE filter, pore size 0.1 μm). Trimethylsilyl 3-butenoate (67.8
g) was obtained as a colorless transparent liquid. (Gas chroma purity 95.
(1%) (2) Synthesis of trimethylsilyl 4-trimethoxysilylbutanoate Trimethylsilyl 3-butenoate (50.0 g) was placed in a 300 mL three-necked flask equipped with a dropping funnel and a stirring blade. Furthermore, chloroplatinic acid hexahydrate (Wako Pure Chemical Industries, 1
A solution of 7 mg) in 2-propanol (0.4 mL) was added. Add trimethoxysilane (3
8.8 g) was added. The three-necked flask was immersed in an ice bath, cooled, and added dropwise with stirring for about 20 minutes. Then, it was left at room temperature overnight. Purified by vacuum distillation, trimethylsilyl 4-trimethoxysilylbutanoate (47.3
g) was obtained as a colorless transparent liquid. (Gas chroma purity 87.
1%) (3) Hydrolysis of three-dimensional crosslinkable compound having an element other than carbon as a crosslinking point (3a) 1,6-bis (trimethoxysilyl) hexane (1.35 g) manufactured by Gelest Co. at 1C at 0 ° C. Hydrochloric acid (0.
68 g) was added and stirred at room temperature for 30 minutes to obtain a colorless and transparent hydrolyzate.

(3b) To the trimethylsilyl 5-trimethoxysilylbutanoate (1.0 g) obtained in (2) above was added 1M hydrochloric acid (0.40 g) at 0 ° C., and the mixture was stirred at room temperature for 30 minutes to give a colorless solution. A clear hydrolyzate was obtained. (4) Preparation of polymer solid electrolyte membrane Hydrolyzate of the above (3a) and (3b) and Example 12
The sulfonated polyphenylene oxide DMAc solution (1) (1) was mixed. This liquid was cast on a glass plate and heated at 100 ° C. for 3 hours to prepare a polymer solid electrolyte membrane. The film thickness was 180 μm. (5) Performance Evaluation of Polymer Solid Electrolyte Membrane The membrane obtained in (4) above was evaluated for methanol permeation amount and ionic conductivity in the same manner as in Comparative Example 1. The amount of methanol permeation through this membrane was 1.4 μmol / cm ² · min,
Compared to Comparative Example 1, methanol crossover was suppressed. The ionic conductivity was 4.7 S / cm ² , which was about the same as in Comparative Example 1.

Example 14 (1) Hydrolysis of a three-dimensional crosslinkable compound having an element other than carbon as a crosslink point (1a) 0 to 1,6-bis (trimethoxysilyl) hexane (1.35 g) manufactured by Gelest 1M hydrochloric acid (0.
68 g) was added and stirred at room temperature for 30 minutes to obtain a colorless and transparent hydrolyzate.

(1b) 1M hydrochloric acid (0.40) was added to a compound represented by the formula (S1) (manufactured by Azumax Co., Ltd., 1.0 g) at 0 ° C.
g) was added and stirred at room temperature for 30 minutes to obtain a colorless and transparent hydrolyzate.

[0149]

[Chemical formula 22]

(2) Preparation of Polymer Solid Electrolyte Membrane Hydrolyzate of (1a) and (1b) above and Example 12
The sulfonated polyphenylene oxide DMAc solution (1) (1) was mixed. This liquid was cast on a glass plate and heated at 100 ° C. for 3 hours to prepare a polymer solid electrolyte membrane. The film thickness was 185 μm. (3) Performance Evaluation of Polymer Solid Electrolyte Membrane The membrane obtained in (2) above was evaluated for methanol permeation amount and ionic conductivity in the same manner as in Comparative Example 1. The amount of methanol permeated through this membrane was 1.3 μmol / cm ² · min,
Compared to Comparative Example 1, methanol crossover was suppressed. The ionic conductivity was 4.8 S / cm ² , which was about the same as in Comparative Example 1.

Example 15 (1) Hydrolysis of three-dimensional crosslinkable compound having an element other than carbon as a crosslinking point (1a) 0 in 1,6-bis (trimethoxysilyl) hexane (1.35 g) manufactured by Gelest 1M hydrochloric acid (0.
68 g) was added and stirred at room temperature for 30 minutes to obtain a colorless and transparent hydrolyzate.

(1b) The compound represented by the formula (S2) (Ge
Lest, 0.74 g) and DMAc (0.74)
1M hydrochloric acid (0.24 g) was added to the solution consisting of g) at 0 ° C., and the mixture was stirred at room temperature for 30 minutes to obtain a hydrolyzate.

[0153]

[Chemical formula 23]

(2) Preparation of Polymer Solid Electrolyte Membrane Hydrolyzate of (1a) and (1b) above and Example 12
The sulfonated polyphenylene oxide DMAc solution (1) (1) was mixed. This liquid was cast on a glass plate and heated at 100 ° C. for 3 hours to prepare a polymer solid electrolyte membrane. The film thickness was 195 μm. (3) Performance Evaluation of Polymer Solid Electrolyte Membrane The membrane obtained in (2) above was evaluated for methanol permeation amount and ionic conductivity in the same manner as in Comparative Example 1. The amount of methanol permeated through this membrane was 1.6 μmol / cm ² · min,
Compared to Comparative Example 1, methanol crossover was suppressed. The ionic conductivity was 5.5 S / cm ² , which was equal to or higher than that of Comparative Example 1.

Example 16 (1) Synthesis of sulfonated polyether ether ketone Polyether ether ketone (PE manufactured by Victorex Co., Ltd.)
EK) (3.0 g) was dissolved in concentrated sulfuric acid (150 ml), and the reaction was carried out at room temperature for 4 days while stirring. The obtained mixture was poured into a large amount of ether, the white precipitate was filtered off, washed and dried to obtain a sulfonated polyether ether ketone. The sulfonated polyether ether ketone was dissolved in DMAc to give a 20 wt% solution. (2) Hydrolysis of a three-dimensional crosslinkable compound having an element other than carbon as a crosslinking point (2a) 1,6-bis (trimethoxysilyl) hexane (1.35 g) manufactured by Gelest Co. was added at 0 ° C. to 1M hydrochloric acid (0 ．
68 g) was added and stirred at room temperature for 30 minutes to obtain a colorless and transparent hydrolyzate.

(2b) The compound represented by the formula (S3) (Ge
Lest, 0.80 g) and DMAc (0.80)
1M hydrochloric acid (0.24 g) was added to the solution consisting of g) at 0 ° C., and the mixture was stirred at room temperature for 30 minutes to obtain a hydrolyzate.

[0157]

[Chemical formula 24]

(3) Preparation of Polymer Solid Electrolyte Membrane The hydrolyzate of (2a) and (2b) and the sulfonated polyetheretherketone DMAc solution (1) of (1) above.
9.5 g) were mixed. This liquid was cast on a glass plate and heated at 100 ° C. for 3 hours to prepare a polymer solid electrolyte membrane. The film thickness was 204 μm. (3) Performance Evaluation of Polymer Solid Electrolyte Membrane The membrane obtained in (2) above was evaluated for methanol permeation amount and ionic conductivity in the same manner as in Comparative Example 1. The amount of methanol permeated through this membrane was 1.6 μmol / cm ² · min,
Compared to Comparative Example 1, methanol crossover was suppressed. The ionic conductivity was 4.9 S / cm ² , which was equivalent to that of Comparative Example 1.

Example 17 (1a) 1,6-bis (trimethoxysilyl) hexane (1.35 g) manufactured by Gelest was added to 1 M hydrochloric acid (0.
68 g) was added and stirred at room temperature for 30 minutes to obtain a colorless and transparent hydrolyzate.

(1b) Electrochimica Acta, Vol.45, 137
3-triethoxysilylpropanesulfonyl chloride (0.97 g) and diethylene glycol dimethyl ether (0.97) synthesized by the method described in 7-1383 (2000).
1M hydrochloric acid (0.32 g) was added to the solution consisting of g) at 0 ° C., and the mixture was stirred at room temperature for 30 minutes to obtain a hydrolyzate. (2) Preparation of polymer solid electrolyte membrane Hydrolyzate of the above (1a) and (1b) and Example 12
The sulfonated polyphenylene oxide DMAc solution (1) (1) was mixed. This liquid was cast on a glass plate and heated at 100 ° C. for 3 hours to prepare a polymer solid electrolyte membrane. The film thickness was 195 μm. (3) Performance Evaluation of Polymer Solid Electrolyte Membrane The membrane obtained in (2) above was evaluated for methanol permeation amount and ionic conductivity in the same manner as in Comparative Example 1. The membrane has a methanol permeation rate of 1.7 μmol / cm ² · min,
Compared to Comparative Example 1, methanol crossover was suppressed. The ionic conductivity was 5.6 S / cm ² , which was equal to or higher than that of Comparative Example 1.

Example 18 (1) Hydrolysis of a three-dimensional crosslinkable compound having an element other than carbon as a crosslinking point (1a) Bis (3-triethoxysilylpropyl) urea (2.47 g) manufactured by Gelest Co. was added at 0 ° C. 1M hydrochloric acid (0.
37 g) was added and stirred at room temperature for 30 minutes to obtain a hydrolyzate.

(1b) The compound represented by the formula (S2) (Ge
Lest, 0.74 g) and DMAc (0.74)
1M hydrochloric acid (0.24 g) was added to the solution consisting of g) at 0 ° C., and the mixture was stirred at room temperature for 30 minutes to obtain a hydrolyzate.

[0163]

[Chemical 25]

(2) Preparation of Polymer Solid Electrolyte Membrane Hydrolyzate of (1a) and (1b) above and Example 12
The sulfonated polyphenylene oxide DMAc solution (1) (1) was mixed. This liquid was cast on a glass plate and heated at 100 ° C. for 3 hours to prepare a polymer solid electrolyte membrane. The film thickness was 195 μm. (3) Performance Evaluation of Polymer Solid Electrolyte Membrane The membrane obtained in (2) above was evaluated for methanol permeation amount and ionic conductivity in the same manner as in Comparative Example 1. The amount of methanol permeation through this membrane was 1.5 μmol / cm ² · min,
Compared to Comparative Example 1, methanol crossover was suppressed. The ionic conductivity was 5.2 S / cm ² , which was equal to or higher than that of Comparative Example 1.

Example 19 (1) Synthesis of sulfonated polyether ether sulfone Polyether ether sulfone (3.0 g) was dissolved in concentrated sulfuric acid (150 ml), and the reaction was carried out at room temperature for 4 days with stirring. The obtained mixture was poured into a large amount of ether, the white precipitate was filtered off, washed and dried to obtain a sulfonated polyether ether sulfone. The sulfonated polyether ether sulfone was dissolved in DMAc to prepare a 20 wt% solution. (2) Hydrolysis of a three-dimensional crosslinkable compound having an element other than carbon as a crosslinking point (2a) 1,6-bis (trimethoxysilyl) hexane (1.35 g) manufactured by Gelest Co. was added at 0 ° C. to 1M hydrochloric acid (0 ．
68 g) was added and stirred at room temperature for 30 minutes to obtain a colorless and transparent hydrolyzate.

(2b) The compound represented by the formula (S3) (Ge
Lest, 0.80 g) and DMAc (0.80)
1M hydrochloric acid (0.24 g) was added to the solution consisting of g) at 0 ° C., and the mixture was stirred at room temperature for 30 minutes to obtain a hydrolyzate.

[0167]

[Chemical formula 26]

(3) Preparation of Polymer Solid Electrolyte Membrane The hydrolyzate of (2a) and (2b) and the sulfonated polyetherethersulfone DMAc solution (19.5 g) of (1) were mixed. This liquid was cast on a glass plate and heated at 100 ° C. for 3 hours to prepare a polymer solid electrolyte membrane. The film thickness was 196 μm. (3) Performance Evaluation of Polymer Solid Electrolyte Membrane The membrane obtained in (2) above was evaluated for methanol permeation amount and ionic conductivity in the same manner as in Comparative Example 1. The amount of methanol permeated through this membrane was 1.6 μmol / cm ² · min,
Compared to Comparative Example 1, methanol crossover was suppressed. The ionic conductivity was 4.7 S / cm ² , which was equivalent to that of Comparative Example 1.

[0169]

According to the present invention, a novel polymer electrolyte capable of suppressing methanol crossover, having high ionic conductivity, and achieving high output, a method for producing the same, and a high-performance solid polymer type using the same A fuel cell can be provided and its utility is high.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of a solid polymer electrolyte of the present invention.

FIG. 2 Porous part 1 in the solid polymer electrolyte of the present invention
It is the plane schematic diagram which expanded.

FIG. 3 is a scanning electron micrograph of a porous substrate in which the pores used in the polymer solid electrolyte of the present invention are arranged in an orderly manner.

FIG. 4 is a scanning electron micrograph of a porous substrate used in a conventional solid polymer electrolyte.

FIG. 5 is a scanning electron micrograph of a porous substrate having a three-dimensional network structure used in the solid polymer electrolyte of the present invention.

FIG. 6 is a schematic perspective view of a polymer solid electrolyte having a side-by-side structure according to the present invention.

FIG. 7: Side-by-using the solid polymer electrolyte of the present invention
It is a cross-sectional schematic diagram which shows a part of manufacturing process of a side structure fuel cell.

[Explanation of symbols]

1: Porous part 2: Non-porous part 3: Hole 4: Membrane conductive part 5: Transmembrane electron conduction part 6: Proton conducting part 7: Electrode d: Pore diameter L: Center distance between adjacent through holes

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masataka Nakamura             1-1 1-1 Sonoyama, Otsu City, Shiga Prefecture Toray Co., Ltd.             Ceremony company Shiga business site F-term (reference) 4F070 AA23 AA55 AA56 AA58 AA72                       AC52 AC67 AE08 GA01 GA03                       GC02                 5G301 CA30 CD01                 5H026 AA06 AA08 BB00 CX05 EE18

Claims (13)

[Claims] 1. A polymer solid comprising a polymer having an anionic group and a three-dimensional cross-linked body having an element other than carbon as a cross-linking point, and having an internally penetrating polymer network structure. Electrolytes. 2. The three-dimensional crosslinked product having an element other than carbon as a crosslinking point has an ionic group.
The solid polymer electrolyte according to 1. 3. The solid polymer electrolyte according to claim 2, wherein the ionic group is at least one selected from a sulfonic acid group, a carboxyl group and a phosphonic acid group. 4. The element other than carbon, which serves as a crosslinking point, comprises at least one element selected from silicon, titanium, zirconium, aluminum, boron and phosphorus. The polymer solid electrolyte as described in 1. 5. The polymer solid electrolyte according to claim 1, wherein the polymer having an anionic group contains a polar group other than an anionic group in the main chain. 6. The polymer having an anionic group, wherein the polar group other than the anionic group is a sulfonyl group, an oxy group, a thio group, a carbonyl group, an ester group, an amide group or an imide group and the following formula (1): And at least one kind selected from polar groups represented by the following formula (2), the solid polymer electrolyte according to claim 5. Formula (1) Formula (2) (Here, R, R ₁ and R ₂ represent organic groups, and R ₁ and R ₂ may be the same or different.) 7. The polymer having an anionic group, wherein the anionic group is at least one functional group selected from sulfonic acid, phosphonic acid, phosphoric acid and carboxylic acid. 6. The solid polymer electrolyte according to any one of 6 above. 8. A polyphenylene sulfide sulfone, wherein the polymer having an anionic group is represented by the following formula (3):
Polyphenylene sulfide represented by the following formula (4), polyphosphazene represented by the following formula (5), polyimide represented by the following formula (6), and at least one selected from polybenzimidazole and polysulfone 7. The solid polymer electrolyte according to claim 1, wherein Formula (3) Formula (4) Formula (5) Formula (6) (Here, Z is an organic group containing an aromatic ring, n is the number of repetitions, R ₁ and R ₂ are organic groups, and R ₁ and R ₂ may be the same or different.) 9. A polymer solid electrolyte membrane comprising a porous substrate filled with the polymer solid electrolyte according to any one of claims 1 to 8. 10. The polymer according to claim 9, wherein in the porous substrate, the holes are a plurality of through holes independent in the film thickness direction and are arranged in order in the film surface direction. Solid electrolyte membrane. 11. A solution containing at least a three-dimensional crosslinkable compound containing an element other than carbon and / or a hydrolyzate thereof and a polymer having an anionic group, and using an element other than the carbon as a crosslinking point. A method for producing a polymer solid electrolyte, which comprises subjecting a three-dimensionally crosslinkable compound and / or a hydrolyzate thereof to condensation polymerization to form an internally penetrating polymer network structure. 12. A polymer electrolyte fuel cell comprising the polymer solid electrolyte or the polymer solid electrolyte membrane according to claim 1. 13. A fuel comprising an aqueous methanol solution.
2. The polymer electrolyte fuel cell according to item 2.