JP2005327703A - Solid polyelectrolyte, solid polymer gel film, solid polyelectrolyte film, and fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solid polyelectrolyte, a solid polyelectrolyte film, and a solid polymer gel film superior in ion conductivity and methanol preventive characteristics, and provide the solid polyelectrolyte film including the solid polymer gel film. <P>SOLUTION: The solid polyelectrolyte contains a composition obtained by mixing a polymer solution having an acid group and a polymer solution having a basic group. The polymer having the acid group is an aliphatic polymer having at least one kind selected from a group composed of a sulfonic acid group, a phosphonic acid group and carboxylic group at a side chain, and the polymer having the basicity is the aliphatic polymer or an aromatic polymer having at least one kind selected from a group composed of an amino group, an amide group, and a urea group in the main chain or in the side chain. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an ion conductive solid polymer electrolyte. More specifically, the present invention relates to a solid polymer gel film having high ion conductivity and a solid polymer electrolyte film. This solid polymer electrolyte membrane includes fuel cells, ion conductive membranes for solid polymer electrolyte fuel cells, redox cells, electrodialysis membranes, reverse osmosis membranes, nanofiltration membranes, diffusion dialysis membranes, gas separation membranes, pervaporation and Used in the fields of osmotic extraction membranes, humidity sensors, and gas sensors. In addition, the solid polymer electrolyte membrane formed by sandwiching the solid polymer gel membrane according to the present invention between porous membranes has extremely low methanol permeability, and is used as an electrolyte membrane for a direct methanol fuel cell (hereinafter referred to as DMFC). used.

In recent years, fuel cells are becoming important as next-generation clean energy sources. Among these fuel cells, a solid polymer electrolyte fuel cell (hereinafter referred to as PEFC) has both anode and cathode electrodes disposed on both sides of a solid polymer electrolyte membrane. For example, when methanol is used as a fuel in this PEFC, an electrochemical reaction can be caused by supplying methanol to the anode side and oxygen or air to the cathode side. As a result, electricity is generated.
Development of a solid polymer electrolyte membrane having high proton conductivity has been carried out in order to realize a fuel cell having high power and high energy density while maintaining the characteristics of the fuel cell. In addition, the solid polymer electrolyte membrane used in the DMFC has high ionic conductivity while retaining fuel methanol, that is, the permeation of fuel methanol from the anode side to the cathode side in the solid polymer electrolyte membrane. It is required to reduce (crossover).

  Conventionally, hydrated perfluorocarbon sulfonic acid (hereinafter referred to as PFS) polymer (for example, DuPont's product name Nafion Membrane (registered trademark), etc.) has high ionic conductivity. Widely used and studied as an electrolyte membrane. However, a hydrated PFS polymer membrane has a theoretical limit in methanol blocking property because methanol having high affinity with water easily passes (crossover). As a means for reducing methanol crossover in a PFS polymer hydrated film, it is considered to combine different materials based on the PFS polymer hydrated film. However, the above composite has a problem that the high ionic conductivity of the original PFS polymer hydrated film is significantly reduced.

As means for solving these problems, Patent Document 1 discloses using a meta-type polyaniline obtained by impregnating Nafion 112 membrane (trade name, manufactured by DuPont) with aniline. It is disclosed that this meta-type polyaniline has an ionic conductivity comparable to that of Nafion membrane (registered trademark) and a methanol blocking property of about 1/3 that of Nafion membrane (registered trademark). Still not enough to use. In addition, since the expensive Nafion membrane (registered trademark) is further processed, the number of steps becomes large and complicated, and as a result, the membrane must be made more expensive.
On the other hand, a graft copolymer having a basic group having a water-soluble main chain and a side chain insoluble in water, and an acidic group having a water-soluble main chain and water insoluble. Patent Document 2 discloses a method for producing a zwitterionic polymer gel obtained by mixing a graft copolymer comprising side chains and a polymer gel membrane formed by forming the zwitterionic polymer gel. . This zwitterionic polymer gel is characterized in that the degree of swelling greatly changes due to pH change. However, Patent Document 2 does not describe any ion conductive membrane. Even if the polymer gel membrane is used as a fuel cell membrane, the volume and area of the membrane greatly change due to pH changes in the fuel cell during power generation, so that it does not serve as a fuel cell membrane. There is even a risk of destroying the fuel cell itself.
On the other hand, Patent Document 3 discloses a solid polymer film obtained by impregnating a main polymer having an acidic or basic moiety with a secondary polymer having a basic or acidic moiety, and a method for producing the same. However, this solid polymer membrane still has many problems such as not exhibiting sufficient ion conductivity.

In addition to the above, polyethyleneimine doped with sulfuric acid or phosphoric acid (see non-patent document 1) Polysilamine doped with phosphoric acid (see nonpatent document 2), polyacrylamide doped with sulfuric acid or phosphoric acid There are examples (see Non-Patent Document 3), examples in which polybenzimidazole is doped with phosphoric acid (see Patent Document 4), and examples in which polybenzimidazole is added to sulfonated polyethersulfone (see Non-Patent Document 4). There are many problems such as the dopant flowing down and not exhibiting sufficient ion conductivity.
Japanese Patent Laid-Open No. 2001-81220 JP-A-6-145464 JP 2001-236993 A Japanese National Patent Publication No. 11-503262 D. Schoolmann, O. Trinquent, and J.-C. Lassegues, Electrochim Acta, 37, 1619 (1992) K. Tsuruhara, M. Rikukawa, K. Sunui, N. Ogata, Y. Nagasaki, and M. Kato, Electrochim Acta, 45, 1391 (2000) W. Wieczorek and JR Stevens, Polymer, 38, 2057 (1997) J. Kerrer, A. Ullrich, F. Meier and T. Harig, Solid State Ionics, 125, 243 (1999)

  The present invention has been made in order to solve the present problems of the PFS polymer hydrated film, PFS modified film, and various electrolyte films as the solid polymer electrolyte for DMFC as described above. An object of the present invention is to provide a solid polymer electrolyte membrane excellent in methanol blocking property while maintaining conductivity at low cost.

As a result of intensive studies on the above problems, the present inventors have found that a solid polymer electrolyte containing a composition obtained by mixing a polymer solution having a specific acidic group and a polymer solution having a specific basic group, A molecular electrolyte membrane, a solid polymer gel membrane with specific properties, and a solid polymer electrolyte membrane in which the solid polymer gel membrane is sandwiched between porous membranes improve methanol permeability while maintaining particularly high ionic conductivity. As a result, the present invention was reached.
That is, the present invention is a solid polymer electrolyte containing a composition obtained by mixing a polymer solution having an acidic group and a polymer solution having a basic group, wherein the polymer having an acidic group is a sulfonic acid group, An aliphatic polymer having at least one selected from the group consisting of a phosphonic acid group and a carboxyl group in the side chain, wherein the basic polymer is selected from the group consisting of an amino group, an amide group, and a urea group. And a solid polymer electrolyte that is an aliphatic polymer or an aromatic polymer having at least one kind in the main chain or side chain.

  In the solid polymer electrolyte of the present invention, the composition has a pH value of 6 or less, or 8 or more, and the ratio of the functional group equivalent number of the polymer having the acidic group to the polymer having the basic group is 20. / 80 to 80/20, the polymer content is 10 to 90% by weight, and the polymer having an acidic group is polyperfluorocarbon sulfonic acid, polyacrylamide methylpropane sulfonic acid, polyacid phosphohydroxyethyl It is a methacrylate, poly (meth) acrylic acid, polystyrene sulfonic acid, or isobutylene maleic anhydride copolymer, and the polymer having the basic group is polyacrylamide, polyallylamine, polydimethylaminoethyl (meth) acrylate, aminopolyacrylamide , Polyaminosulfone, Polyvinyl It is pyridine, polyvinyl pyrrolidone, polyvinyl caprolactam, polyvinyl carbazole, polyvinyl diaminotriazine, or polyethyleneimine, further contains a filler, further contains a matrix polymer, and the matrix polymer includes polyolefin, halogenated polyolefin, polyvinyl alcohol, Each of them preferably contains at least one selected from the group consisting of polystyrene, polyimide, polybenzimidazole, polyoxazole, polycarbonate, polyparavinylphenol, polyethylene oxide, polyphenylene oxide, and derivatives thereof.

Further, in the solid polymer electrolyte containing a filler, the filler is a siloxane resin, sulfonated pitch, sulfonated carbon, montmorillonite, or acidic zeolite, and the amount of the filler added in the solid polymer electrolyte The amount is preferably 5 to 300 parts by weight with respect to 100 parts by weight of the polymer.
Further, in the solid polymer electrolyte containing a matrix polymer, the total content of the polymer having an acidic group and the polymer having a basic group is 5 to 90% by weight, and the matrix polymer is polytetra Fluoroethylene, polyvinyl chloride, polyvinyl chloride copolymer, styrene-acrylonitrile copolymer, vinyl acetate-vinyl pyridine copolymer, polyethylene, polyethylene-vinyl alcohol copolymer, polypropylene, polyvinylidene chloride, or ethylene tetrafluoro It is preferably an ethylene copolymer, further containing a crosslinking agent, and crosslinked with heat, light, or electron beam.

The present invention is a solid polymer gel film formed by forming the solid polymer electrolyte.
In addition, the present invention is a solid polymer electrolyte membrane in which the solid polymer gel membrane is sandwiched between porous membranes. In the solid polymer electrolyte membrane of the present invention, the Gurley value of the porous membrane is preferably 100 seconds / 100 ml or less.
The present invention is a solid polymer electrolyte membrane formed by forming a solid polymer electrolyte containing a matrix polymer.
The present invention also provides the solid polymer electrolyte membrane, the solid polymer gel membrane, or the solid polymer gel membrane formed by sandwiching the solid polymer gel membrane with a porous membrane, and these solid polymer gel membranes or A fuel cell comprising a positive electrode and a negative electrode sandwiching a solid polymer electrolyte membrane.

  According to the present invention, proton conduction is achieved by forming a solid polymer electrolyte containing a composition obtained by mixing a polymer solution having a specific acidic group and a polymer solution having a specific basic group. Thus, a solid polymer electrolyte membrane or a solid polymer electrolyte gel membrane excellent in properties and methanol blocking properties can be obtained. A solid polymer electrolyte membrane excellent in proton conductivity and methanol blocking property can be obtained by sandwiching a solid polymer gel membrane containing a specific property or a solid polymer gel membrane containing a filler between porous membranes. These solid polymer electrolyte membranes are useful as solid polymer electrolyte membranes for fuel cells, particularly for DMFC. Moreover, the production of the solid polymer electrolyte membrane of the present invention is simple and can be produced at low cost.

The polymer having an acidic group in the present invention may be a polymer having a sulfonic acid group, a phosphonic acid group, or a carboxyl group in the side chain of the aliphatic polymer, and a plurality of these different functional groups may be bonded. good. In addition, some or all of the hydrogen atoms bonded to carbon may be substituted with fluorine atoms. Furthermore, the polymer having an acidic group may be a random copolymer, a block copolymer, or a cross-copolymer copolymerized with copolymerizable vinyl monomers. Examples of vinyl monomers that can be covalently bonded include acrylamide, acrylonitrile, vinyl acetate, styrene, various (meth) acrylates, vinyl pyridine, vinyl pyrrolidone, vinyl caprolactam, and derivatives thereof. Any monomer that can be copolymerized may be used.
In this specification, “acrylic acid” and “methacrylic acid” are collectively referred to as (meth) acrylic acid, and “acrylate” and “methacrylate” are collectively referred to as (meth) acrylate.

  Specific examples of the polymer having an acidic group include a PFS resin solution (for example, Nafion resin solution (SE-10072) manufactured by DuPont), polyacrylamide methylpropanesulfonic acid, polyacid phosphooxyethyl methacrylate, and poly (meth) acrylic. Examples of the acid, polystyrene sulfonic acid, isobutylene maleic anhydride copolymer, other polymers having a sulfonic acid group, a phosphonic acid group, or a carboxyl group, and a polymer having an aromatic ring in the side chain, etc. It is not limited to the above, and any material may be used as long as it is formed as an aliphatic polymer having at least one selected from the group consisting of a sulfonic acid group, a phosphonic acid group, and a carboxyl group in the side chain.

  The polymer having a basic group in the present invention may be a polymer having an amino group, an amide group, or a urea group in the polymer main chain or side chain, and a plurality of these different functional groups may be bonded. . Further, some or all of the hydrogen atoms bonded to carbon may be substituted with fluorine atoms. Furthermore, the polymer having a basic group may be a random copolymer, a block copolymer, or a cross-copolymer copolymerized with copolymerizable vinyl monomers. Examples of vinyl monomers that can be covalently bonded include acrylamide, acrylonitrile, acrylic acid, vinyl acetate, styrene, various (meth) acrylates, and derivatives thereof, but are not particularly limited and can be copolymerized. Any vinyl monomer may be used.

  Specific examples of the polymer having a basic group include polyacrylamide, polyallylamine (for example, PAA and PAS manufactured by Nitto Boseki Co., Ltd.), polydimethylaminoethyl (meth) acrylate, aminopolyacrylamide, polyaminosulfone, polyvinylpyridine, Examples include polyvinylpyrrolidone, polyvinylcaprolactam, polyvinylcarbazole, polyvinyldiaminotriazine, Aciplex A211 (trade name, manufactured by Asahi Kasei Co., Ltd.), Selemion AMV (trade name, manufactured by Asahi Glass Co., Ltd.), polyethyleneimine, and derivatives thereof. Examples of the polymer having an aromatic ring may include, but are not limited to, a main chain or a side chain at least one selected from the group consisting of an amino group, an amide group, and a urea group. What is necessary is just to be formed as an aliphatic polymer or an aromatic polymer.

  A uniform putty-like or jelly-like composition can be obtained by putting a predetermined amount of these ionic polymers in a normal aqueous solution or alcohol solution into a kneader and mixing and stirring. At this time, you may mix together other additives, such as antioxidant (a radical scavenger, a hydroperoxide decomposition agent, etc.) and a coloring agent. By forming this composition into a film, the solid polymer gel film of the present invention is obtained.

  The above-mentioned polymer having an acidic group and the polymer having a basic group may be mixed. In addition, a copolymer of a monomer having an acidic group and a monomer having a basic group, a copolymer of a nonpolar monomer and a monomer having an acidic group, or a nonpolar monomer and a monomer having a basic group Copolymers can also be used. Examples of nonpolar monomers include styrene derivatives, methacrylates, acrylonitrile, vinyl acetate, other monomers having a vinyl group, or monomers having an aromatic ring.

  When the pH value of the composition obtained by mixing the polymer solution having an acidic group and the polymer solution having a basic group is in the range of 0 or more and 6 or less, or 8 or more and 14 or less, desired ion conduction Degree and methanol blocking ability can be expressed. A composition having a pH value of 0 or more and 6 or less can be obtained by mixing a polymer solution having a strongly acidic group and a polymer solution having a weakly basic group. For example, by mixing a predetermined amount of a PFS resin solution (for example, Nafion resin solution (SE-10072) manufactured by DuPont) or a polyacrylamide methyl propane sulfonic acid solution with a polyacrylamide solution, polyvinyl pyrrolidone, or polyvinyl pyridine, the pH is adjusted. A composition having a value of 0 or more and 6 or less can be obtained, but the composition is not limited thereto. A composition having a pH value of 8 or more and 14 or less can be obtained by mixing a polymer solution having a weakly acidic group and a polymer solution having a strongly basic group. For example, a composition having a pH value of 8 or more and 14 or less by mixing a predetermined amount of polyallylamine (for example, PAA-10C manufactured by Nitto Boseki Co., Ltd.) and polyacrylic acid or styrene-maleic acid copolymer. However, the present invention is not limited to these.

When mixing the polymer solution having an acidic group and the polymer solution having a basic group, the ratio of the number of equivalents of these functional groups (the number of equivalents of acidic groups in the polymer having acidic groups / in the polymer having basic groups) The equivalent number of basic groups) is preferably 20/80 to 80/20, more preferably 30/70 to 70/30, and particularly preferably 40/60 to 60/40.
When the ratio of the number of functional group equivalents is within the range of 20/80 to 80/20, sufficient ionic conductivity is obtained. The number of functional group equivalents is determined by neutralization titration.

  Although a method of adsorbing a polymer having a basic group on the surface of a commercially available Nafion membrane (registered trademark) is also conceivable, the surface treatment is performed by immersing the Nafion membrane (registered trademark) in a polyacrylamide polymer aqueous solution. As a result, desired ionic conductivity and methanol blocking ability were not obtained. Thus, even if a membrane having a sulfonic acid group is simply impregnated with a polymer having a basic group, effective ion conductivity cannot be obtained.

  When the polymer solution having an acidic group and the polymer solution having a basic group are mixed, the polymer content in the composition obtained by mixing is preferably 10 to 90% by weight, more preferably 12 to 80% by weight. Particularly preferred is 15 to 70% by weight. When the polymer content in the composition obtained by mixing is 10% by weight or more, sufficient ionic conductivity is obtained. On the other hand, when the polymer content in the composition obtained by mixing is 90% by weight or less, the gel-like resin composition itself does not become brittle, and a film having mechanical strength as an electrolyte film can be formed. it can.

  According to this invention, you may add a filler to the composition obtained by mixing the polymer solution which has the above-mentioned acidic group, and the polymer solution which has a basic group. Examples of the filler to be added include siloxane resin, sulfonated pitch, sulfonated carbon, montmorillonite, and acidic zeolite. Examples of the raw material pitch for sulfonation include coal pitch, petroleum pitch, and synthetic pitch, but synthetic pitch excellent in chemical purity and quality stability (for example, AR pitch manufactured by Mitsubishi Gas Chemical Company). Is preferred. Examples of the raw material carbon for sulfonation include fullerene, carbon nanotube, carbon nanohorn, and carbon nanofiber. For sulfonation, sulfuric acid or fuming sulfuric acid is usually used (see Synthesis Examples), but is not particularly limited thereto.

  The amount of the filler added is preferably 5 to 300 parts by weight, more preferably 10 to 200 parts by weight with respect to 100 parts by weight of the ionic polymer. When the filler addition amount is 5 parts by weight or more, the effect of adding the filler, that is, the kneading state between the ionic polymers and the strength improvement of the kneaded jelly-like composition can be obtained. On the other hand, when the filler addition amount is 300 parts by weight or less, the gel-like resin composition itself does not become brittle, and a film having mechanical strength as an electrolyte film can be formed.

The solid polymer electrolyte membrane of the present invention is obtained by sandwiching both surfaces of the solid polymer electrolyte gel membrane 1 with a porous membrane 2 as shown in FIG.
The Gurley value (indicating the air permeability of the membrane) of the porous membrane 2 used in the present invention is preferably 100 seconds / 100 ml or less, more preferably 80 seconds / 100 ml or less, particularly preferably 50 seconds / 100 ml or less. It is. Note that the Gurley value, the paper or paperboard surface area 642 mm ² refers to the time that air 100ml passes. In the present invention, the Gurley value is measured by the Gurley tester method described in JIS P 8117.
Examples of the membrane base material include polyolefin films such as polyethylene and polypropylene, fluorine-based films represented by polytetrafluoroethylene (PTFE), polyimide, and engineering plastics such as polyphenylene ether. Any material that satisfies the above-described physical properties may be used, and the present invention is not particularly limited thereto.

  The matrix polymer in the present invention is kneaded with the above-mentioned polymer having an acidic group and a polymer having a basic group, thereby forming a film as a solid polymer electrolyte membrane of the composition, mechanical strength, chemical resistance, etc. Improved characteristics.

  Specific examples of the matrix polymer include polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polyvinyl chloride copolymer, polyparavinylphenol, polystyrene, styrene-acrylonitrile copolymer, vinyl acetate-vinyl pyridine copolymer, Examples include polyvinyl alcohol, polyethylene-vinyl alcohol copolymer, polyimide, polybenzimidazole, polyoxazole, polycarbonate, polyethylene oxide, polyphenylene oxide, polytetrafluoroethylene, and ethylene tetrafluoroethylene copolymer. The matrix polymer may contain a plurality of these, and is not particularly limited as long as it satisfies the above physical properties.

  A uniform composition can be obtained by putting a predetermined amount of the polymer having an acidic group, the polymer having a basic group, and a matrix polymer into a kneader and mixing and stirring. At this time, a filler and other additives such as a crosslinking agent, an antioxidant (radical scavenger, hydroperoxide decomposing agent) or a colorant may be mixed together. The polymer having an acidic group and the polymer having a basic group are usually added in the form of a powder, an aqueous solution, an alcohol solution, or an organic solution. Furthermore, other organic solvents such as N-methylpyrrolidone, dimethylacetamide, dimethylsulfoxide and the like can be added and kneaded.

  When mixing a polymer having an acidic group, a polymer having a basic group, and a matrix polymer, the total content of the polymer having an acidic group and the polymer having a basic group in the composition obtained by mixing is suitable. Is 5 to 90% by weight, more preferably 8 to 80% by weight, and particularly preferably 10 to 70% by weight. When the total content of the polymer having an acidic group and the polymer having a basic group in the composition is 5% by weight or more, sufficient ionic conductivity is obtained. On the other hand, when the total content of the polymer having acidic groups and the polymer having basic groups in the composition is 90% by weight or less, the composition itself does not become brittle, and a self-supporting film can be formed.

  When a crosslinking agent is added during kneading, this crosslinking agent reacts with a polymer having an acidic group, a polymer having a basic group and / or a matrix polymer to form a crosslinked structure. Thereby, the elution and drop-off of the polymer having an acidic group or the polymer having a basic group from the solid polymer electrolyte membrane can be prevented. Examples of the crosslinking agent to be added include peroxides, diepoxy compounds, diisocyanate compounds, dianhydrides and the like, and peroxides are preferably used.

  As a peroxide, the peroxide described, for example in the Nippon Oils and Fats catalog can be used. Specific examples include t-butyl peroxylaurate, t-butyl peroxyisopropyl monocarbonate, t-butyl peroxybenzoate, and di-t-butyl peroxide.

  The added amount of these peroxides is 0.1 to 10% by weight, preferably 0. 0% by weight, based on the total polymer amount (the total amount of the polymer having an acidic group, the polymer having a basic group, and the matrix polymer). It is 2 to 5% by weight, more preferably 0.2 to 1% by weight. It is effective that the temperature for carrying out the crosslinking reaction is about 80 ° C. to 130 ° C., and the crosslinking time is suitably about 1 to 60 minutes, but it has a polymer having an acidic group and a basic group. What is necessary is just to select suitably according to the kind of a polymer, a matrix polymer, and the crosslinking agent added.

  In order to crosslink the polymer having an acidic group, the polymer having a basic group, and a matrix polymer, a photoinitiator may be used, or crosslinking may be performed by ultraviolet rays or electron beams (for example, gamma rays). In order to introduce a crosslinking reaction and a crosslinked structure, these means may be used in combination.

  The solid polymer electrolyte membrane of the present invention can be obtained by forming a polymer having an acidic group, a polymer having a basic group, and a matrix polymer. An example of a specific film forming method is shown below. First, a Nafion resin (registered trademark) aqueous solution as a polymer having an acidic group, a polyacrylamide aqueous solution as a polymer having a basic group, and a polytetrafluoroethylene as a matrix polymer are each put in a mortar and mixed and kneaded until uniform. . Next, when the kneaded product becomes a putty-like product, the putty-like product is sandwiched between SUS plates and pressed to a predetermined film thickness. For example, in the case of DMFC, the film thickness is not particularly limited as long as desired ion conductivity and methanol blocking property are achieved and a self-supporting film is formed. Generally, it is 10 μm or more and 500 μm or less, preferably 20 μm or more and 300 μm or less, more preferably 30 μm or more and 200 μm or less. Finally, the obtained film is dried in a dryer at 80 ° C. By this film forming method, a desired solid polymer electrolyte membrane can be easily manufactured.

  The ionic conductivity of the solid polymer electrolyte membrane, the solid polymer gel membrane 1, and the solid polymer electrolyte membrane formed by sandwiching the solid polymer gel membrane 1 with the porous membrane 2 is 0. It is 01 S / m or more, preferably 0.1 S / m or more, and more preferably 1 S / m or more.

Further, the methanol permeation rate of the solid polymer electrolyte membrane, the solid polymer gel membrane 1 produced as described above, and the solid polymer electrolyte membrane formed by sandwiching the solid polymer gel membrane 1 with the porous membrane 2 is as follows. It is 2 mg / cm ² / min or less, preferably 1.8 mg / cm ² / min or less, more preferably 1.6 mg / cm ² / min or less.

  As shown in FIGS. 2 to 4, the solid polymer gel membrane 1, the solid polymer electrolyte membrane formed by sandwiching the solid polymer gel membrane 1 with the porous membrane 2, or the solid polymer gel containing the matrix polymer according to the present invention. By sandwiching the molecular electrolyte membrane 5 between the positive electrode 3a and the negative electrode 3b, a fuel cell excellent in methanol blocking property can be obtained while maintaining high ionic conductivity. A gas diffusion layer 4 may be provided on the surfaces of the positive electrode 3a and the negative electrode 3b. By this gas diffusion layer 4, gases such as methanol and oxygen used for power generation are diffused and uniformly distributed on the surfaces of the positive electrode 3a and the negative electrode 3b.

The present invention will be described more specifically with reference to the following examples. However, the present invention is not limited to these examples. In the examples and comparative examples, “parts” and “%” are based on weight unless otherwise specified. Various measurements were performed as follows.
Ion conductivity measurement Ion conductivity was measured according to the following method. First, using the impedance analyzer SI1260 manufactured by Solartron, UK, the solid polymer electrolyte of the present invention, the solid polymer electrolyte membrane 5, the solid polymer gel membrane 1, and the solid polymer gel membrane 1 are made of a porous polyolefin membrane. The high frequency impedance of the sandwiched polymer electrolyte membrane was measured at 25 ° C. Next, the direct current component R was read from the Cole-Cole plot, and proton conductivity (that is, ionic conductivity) was calculated. The Cole-Cole plot is an arc graph of a real part to an imaginary part of a complex ratio for showing the orientation polarization of a substance.
The ionic conductivities of Nafion 112 and Nafion 117 (trade name, manufactured by DuPont) sufficiently immersed in distilled water were 2.2 S / m and 2.5 S / m, respectively.

Measurement of methanol permeation rate Methanol permeability was measured according to the following method. The solid polymer electrolyte membrane 5 of the present invention, the solid polymer gel membrane 1, or the solid polymer electrolyte membrane formed by sandwiching the solid polymer gel membrane 1 with a porous polyolefin membrane is sandwiched in the middle of the communicating tube, and 30 on one side. 100 ml of an aqueous methanol solution was charged with 100 ml of ion-exchanged water on the other side and immersed in a constant temperature water bath at 40 ° C. The methanol permeating into the water side was quantified by gas chromatography, and the methanol permeation rate (mg / cm ² / min) was calculated.
Distillation Nafion 112 and Nafion 117 (trade name, manufactured by DuPont), which was sufficiently immersed in water methanol permeation rate at 30% methanol aqueous solution, respectively 8.8mg / cm ² / min and 4.0 mg / cm ² / min.

pH measurement An aqueous solution having an ionic polymer concentration of 0.2% was prepared, and the pH of this aqueous solution was measured at 25 ° C.

Example 1
10 parts of Nafion aqueous solution (DuPont, SE-10072, 11% aqueous solution) and 10 parts of polyacrylamide copolymer aqueous solution (Arakawa Chemical Industries, KW-387-20, 20% aqueous solution) (in the composition) Polymer concentration: 16%, ratio of acid-base equivalent number: 60/40) Kneading in a mortar. When kneaded, a white putty-like product was obtained, and the pH value of a 0.2% aqueous solution of this putty-like product was 3.53. Next, this putty-like material was placed in a 0.5 mm thick spacer, and both sides of the obtained solid polymer gel film 1 were sandwiched between platinum electrodes, and the ionic conductivity was measured. As a result, it was 2.2 S / m.

Example 2
The putty-like material obtained in Example 1 was placed in a 0.5 mm spacer, and both surfaces were covered with a porous polyolefin film (manufactured by Teijin DSM Soltec, Solpore 7P07B, Gurley value: 4 seconds / 100 ml). The ionic conductivity of the obtained solid polymer electrolyte membrane was 1.0 S / m. Further, the methanol permeation rate in a 30% aqueous methanol solution was 0.7 mg / cm ² / min.

Example 3
The Nafion (registered trademark) aqueous solution of Example 1 was concentrated with an evaporator to obtain a 21% aqueous solution. 9.4 parts of this concentrated Nafion (registered trademark) aqueous solution and 10 parts of a polyacrylamide copolymer aqueous solution (Arakawa Chemical Industries, KW-387-20, 20% aqueous solution) (polymer concentration in the composition: 21%) , Ratio of acid-base equivalent number: 60/40) Kneading in a mortar. When kneaded, a white putty-like material slightly harder than that obtained in Example 1 was obtained. The pH value of the 0.2% aqueous solution of this putty was 3.50. As in Example 1, this putty-like material was formed into a film. The ionic conductivity of the obtained solid polymer gel film 1 having a thickness of 0.5 mm was 3.3 S / m.

Example 4
The putty-like material obtained in Example 3 was charged into a 0.5 mm spacer, and both surfaces were covered with a porous polyolefin membrane (manufactured by Teijin DM Soltec, Solpore 7P07B, Gurley value: 4 seconds / 100 ml). The ionic conductivity of the obtained solid polymer electrolyte membrane was 2.2 S / m. The methanol permeation rate in a 30% aqueous methanol solution was 0.3 mg / cm ² / min.

Example 5
1 part of Nafion aqueous solution (DuPont, SE-10072, 11% aqueous solution) and 9 parts of polyacrylamide copolymer aqueous solution (Arakawa Chemical Industries, KW-387-20, 20% aqueous solution) (in the composition) Polymer concentration: 19%, ratio of acid-base equivalent number: 14/86) Kneading in a mortar. When kneaded, a white putty-like product was obtained, and the pH value of a 0.2% aqueous solution of this putty-like product was 4.21. Next, this putty-like material was placed in a 0.5 mm thick spacer, and both sides of the obtained solid polymer gel film 1 were sandwiched between platinum electrodes, and the ionic conductivity was measured. As a result, it was 0.51 S / m.

Example 6
7 parts of Nafion aqueous solution (DuPont, SE-10072, 11% aqueous solution) and 3 parts of polyacrylamide copolymer aqueous solution (Arakawa Chemical Industries, KW-387-20, 20% aqueous solution) (in the composition) Polymer concentration: 14%, ratio of acid-base equivalent number: 78/22) Kneading in a mortar. When kneaded, a white putty-like product was obtained, and the pH value of a 0.2% aqueous solution of this putty-like product was 3.38. Next, this putty-like material was charged into a 1.0 mm thick spacer, and both surfaces of the obtained solid polymer gel film 1 were sandwiched between platinum electrodes, and the ionic conductivity was measured. As a result, it was 1.2 S / m.

Example 7
The putty-like material obtained in Example 1 was charged into a 0.5 mm spacer, and both surfaces were covered with a porous polyolefin membrane (Espoir N37, Gurley value: 900 seconds / 100 ml, manufactured by Mitsui Chemicals). The ionic conductivity of the obtained solid polymer electrolyte membrane was 0.008 S / m. The methanol permeation rate in a 30% methanol aqueous solution was 0.1 mg / cm ² / min or less.

Example 8
2 parts Nafion aqueous solution (DuPont, Lot No. SE-10072, 11% aqueous solution), 8 parts polyacrylamide copolymer aqueous solution (Arakawa Chemical Industries, KW-387-20, 20% aqueous solution) and (composition) Polymer concentration in the product: 18%, ratio of equivalent number of acid-base: 27/73) and 10 parts of sulfonated pitch (see synthesis example below) were kneaded in a mortar. When kneaded, a black paste was formed, and the pH value of the 0.2% aqueous solution of this paste was 3.11. Next, this paste-like material was charged into a 1.1 mm-thick spacer, both surfaces of the obtained solid polymer gel film 1 were sandwiched between platinum electrodes, and the ionic conductivity was measured. As a result, it was 2.0 S / m.

Synthesis example (sulfonated pitch)
250-300 ml of concentrated sulfuric acid was put into a 500 ml four-necked flask, 30 g of AR pitch pulverized product (particle size: 4-8 μm) manufactured by Mitsubishi Gas Chemical Co., Ltd. was added and stirred, and 50 ml of fuming sulfuric acid was added dropwise over 45 minutes. Then, it stirred at 60 degreeC for 48 hours. Next, the reaction solution was slowly dropped into ice-cooled diethyl ether with stirring, and the solid content was filtered. This solid content was vacuum-dried, and the dry solid content was washed with distilled water and dried again. The ion exchange equivalent of the obtained sulfonated pitch was 0.4 meq / g. This sulfonated pitch was used in Examples 8 and 30.

Example 9
10 parts of Nafion aqueous solution (DuPont, SE-10072, 11% aqueous solution), 10 parts of polyacrylamide copolymer aqueous solution (Arakawa Chemical Industries, KW-387-20, 20% aqueous solution) and (polymer in composition) Concentration 16%, ratio of equivalent number: 60/40) and 4 parts of siloxane resin (X-12-2206, 20% solution, manufactured by Shin-Etsu Chemical Co., Ltd.) were kneaded in a mortar. When kneaded, a white putty-like product was obtained, and the pH value of a 0.2% aqueous solution of this putty-like product was 3.6. Next, this putty-like product was placed in a 0.5 mm thick spacer, and both surfaces were covered with a porous polyolefin membrane (manufactured by Teijin DM Soltec, Solpore 7P07B, Gurley value: 4 seconds / 100 ml). The ionic conductivity of the obtained solid polymer electrolyte membrane was 1.2 S / m. Further, the methanol permeation rate in a 30% aqueous methanol solution was 0.82 mg / cm ² / min.

Example 10
10 parts of Nafion aqueous solution (manufactured by DuPont, SE-10072, 5.5% aqueous solution) and 10 parts of polyacrylamide copolymer aqueous solution (Arakawa Chemical Industries, KW-387-20, 10% aqueous solution) (composition) Polymer concentration inside: 7.8%, ratio of acid-base equivalent number: 60/40) Kneading in a mortar. When kneaded, a white slightly soft putty was obtained. The pH value of the 0.2% aqueous solution of this putty was 3.55. Next, this putty-like material was placed in a 0.5 mm thick spacer, and both sides of the obtained solid polymer gel film 1 were sandwiched between platinum electrodes, and the ionic conductivity was measured. As a result, it was 0.05 S / m.

Example 11
2. 2.1 parts of poly-2-acryloylamino-2-methyl-1-propanesulfonic acid (Toagosei Co., Ltd., Aron A-12SL, 40% aqueous solution) and 5.7 parts of 50% polyacrylamide aqueous solution (in the composition) Polymer concentration: 47%, acid-base equivalent number ratio: 50/50), and kneaded in a mortar. When kneaded, it became a colorless and slightly soft jelly. The pH value of the 0.2% aqueous solution of this jelly-like product was 2.15. Next, this jelly-like product was placed in a 0.5 mm thick spacer, and both surfaces of the obtained solid polymer gel film 1 were sandwiched between platinum electrodes, and the ionic conductivity was measured. As a result, it was 6.0 S / m.

Example 12
7.6 parts of polyacid phosphooxyethyl methacrylate (trade name: Phosmer M homopolymer, 11% IPA solution) and 5.7 parts of 50% polyacrylamide aqueous solution (polymer concentration in the composition: 27.7%, ratio of acid-base equivalent number: 50/50) Kneading in a mortar. When kneaded, it became a colorless and slightly soft jelly. The pH value of the 0.2% aqueous solution of this jelly-like product was 3.6. Next, this jelly-like product was placed in a 0.5 mm thick spacer, and both surfaces of the obtained solid polymer gel film 1 were sandwiched between platinum electrodes, and the ionic conductivity was measured. The result was 3.8 S / m.

Example 13
10 parts polyacrylic acid copolymer aqueous solution (Arakawa Chemical Industries, HP-710, 30% aqueous solution) and 20 parts polyallylamine aqueous solution (Nittobo, polyallylamine 10C, 10% aqueous solution) (in the composition) Polymer concentration: 17%, ratio of acid-base equivalent number: 50/50) Kneading in a mortar. When kneaded, a colorless jelly-like product was obtained, and the pH value of a 0.2% aqueous solution of this jelly-like product was 10.61. Next, this jelly-like product was charged into a 0.2 mm-thick spacer, and both surfaces were covered with a porous polyolefin membrane (manufactured by Teijin DM Soltec, Solpore 7P07B, Gurley value: 4 seconds / 100 ml). The ionic conductivity of the obtained solid polymer electrolyte membrane was 0.22 S / m. Further, the methanol permeation rate in a 30% aqueous methanol solution was 1.68 mg / cm ² / min.

Example 14
3 parts of a polyacrylic acid aqueous solution (Arakawa Chemical Industries, Polymerset HP-710, 30% aqueous solution) and 4 parts of a polyallylamine aqueous solution (Nittobo, PAA-10C, 10% aqueous solution) (composition) Polymer concentration: 18.5%, ratio of acid / base equivalent number: 64/36) Kneading in a mortar. When kneaded, a soft transparent jelly-like product was obtained, and the pH value of a 0.2% aqueous solution of this jelly-like product was 10.5. Next, this jelly-like product was placed in a 0.5 mm thick spacer, and both surfaces of the obtained solid polymer gel film 1 were sandwiched between platinum electrodes, and the ionic conductivity was measured. As a result, it was 1.2 S / m.

Example 15
The jelly-like material obtained in Example 14 was charged into a 0.5 mm spacer, and both surfaces were covered with a porous polyolefin film (Torjin DM Soltec Corp., Solpore 7P07B, Gurley value 4 seconds / 100 ml). The ionic conductivity of the obtained solid polymer electrolyte membrane was 1.0 S / m, and the methanol permeation rate in a 30% aqueous methanol solution was 0.8 mg / cm ² / min.

Example 16
10 parts of polyacrylic acid aqueous solution (manufactured by Dianitics, AP350M, 30% aqueous solution) and 1 part of polyallylamine aqueous solution (manufactured by Nittobo, PAA10C, 10% aqueous solution) (polymer concentration in the composition: 28%, acid) / Ratio of base equivalent number: 97/3) Kneading in a mortar. When kneaded, it became a transparent jelly-like product, and the pH value of a 0.2% aqueous solution of this jelly-like product was 9.8. Next, this jelly-like product was placed in a 0.5 mm thick spacer, and both surfaces of the obtained solid polymer gel film 1 were sandwiched between platinum electrodes, and the ionic conductivity was measured. As a result, it was 0.04 S / m.

Example 17
The polyallylamine aqueous solution of Example 14 was concentrated with an evaporator to obtain a 28% solution. 5 parts of this concentrated polyallylamine aqueous solution and 5 parts of an acrylic acid polymer aqueous solution (Arakawa Chemical Industries, Polymer Set HP-710, 30% aqueous solution) (polymer concentration in the composition: 29%, acid / base equivalent) Number ratio: 54/46) Kneaded in a mortar. When kneaded, a transparent jelly-like product slightly harder than that obtained in Example 1 was obtained. The pH value of the 0.2% aqueous solution of this jelly-like product was 10.3. This jelly-like product was formed in the same manner as in Example 1. The obtained solid polymer gel film 1 having a thickness of 0.5 mm had an ionic conductivity of 4.8 S / m.

Example 18
The jelly-like material obtained in Example 17 was charged into a 0.5 mm spacer, and both surfaces were covered with a porous polyolefin film (Torjin DM Soltec Corp., Solpore 7P07B, Gurley value 4 seconds / 100 ml). The ionic conductivity of the obtained solid polymer electrolyte membrane was 2.2 S / m, and the methanol permeation rate in a 30% aqueous methanol solution was 0.5 mg / cm ² / min.

Example 19
The jelly-like material obtained in Example 17 was charged into a 0.5 mm spacer, and both surfaces were covered with a porous polyolefin film (Espoir N37, Gurley value 900 seconds / 100 ml, manufactured by Mitsui Chemicals). The ionic conductivity of the obtained solid polymer electrolyte membrane was 0.002 S / m, and the methanol permeation rate in a 30% aqueous methanol solution was 0.3 mg / cm ² / min or less.

Example 20
6 parts of a polyacrylic acid aqueous solution (manufactured by Daianitrix, AP350M, 30% aqueous solution), 4 parts of a polyallylamine aqueous solution (manufactured by Nitto Boseki, PAA-10C, 10% aqueous solution) and (polymer concentration in the composition: 22%, The ratio of acid / base equivalent number: 78/22) and 6 parts of a siloxane resin solution (Shin-Etsu Chemical Co., Ltd., X-12, 20% solution) were kneaded in a mortar. When kneaded, a white jelly-like product was formed, and the pH value of a 0.2% aqueous solution of this jelly-like product was 10.3. Next, this jelly-like product was placed in a 1.0 mm thick spacer, and both surfaces of the obtained solid polymer gel film 1 were sandwiched between platinum electrodes, and the ionic conductivity was measured. As a result, it was 6.5 S / m.

Example 21
The jelly-like material obtained in Example 20 was charged into a 0.5 mm spacer, and both surfaces were covered with a porous polyolefin film (manufactured by Teijin DM Soltec, Solpore 7P07B, Gurley value 4 seconds / 100 ml). The obtained solid polymer electrolyte membrane had an ionic conductivity of 3.6 S / m, and a methanol permeation rate in a 30% aqueous methanol solution was 0.96 mg / cm ² / min.

Example 22
6 parts polyacrylic acid aqueous solution (manufactured by Dianitics, AP350M, 30% aqueous solution) and 4 parts polyallylamine aqueous solution (manufactured by Nittobo, PAA-10C, 10% aqueous solution) (polymer concentration in the composition: 22%, acid) / Ratio of base equivalent number: 78/22), 2 parts of a siloxane resin solution (X-12, 20% solution manufactured by Shin-Etsu Chemical Co., Ltd.) and 2 parts of montmorillonite were kneaded in a mortar. When kneaded, a white jelly-like product was formed. The pH value of the 0.2% aqueous solution of this jelly-like product was 10.3. Next, this jelly-like product was placed in a 1.0 mm thick spacer, and both surfaces of the obtained solid polymer gel film 1 were sandwiched between platinum electrodes, and the ionic conductivity was measured. As a result, it was 4.6 S / m.

Example 23
The jelly-like material obtained in Example 22 was charged into a 1.0 mm spacer, and both surfaces were covered with a porous polyolefin membrane (manufactured by Teijin DM Soltec, Solpore 7P07B, Gurley value 4 seconds / 100 ml). The obtained solid polymer electrolyte membrane had an ionic conductivity of 2.3 S / m, and a methanol permeation rate in a 30% aqueous methanol solution was 1.3 mg / cm ² / min.

Example 24
1 part of 50% polyacrylic acid aqueous solution and 2 parts of poly N, N-dimethylaminoethyl methacrylate aqueous solution (30% aqueous solution) (polymer concentration in composition: 37%, ratio of acid / base equivalent number: 35 / 65) Kneading in a mortar. When kneaded, it became a colorless and slightly soft jelly. The pH value of the 0.2% aqueous solution of this jelly-like product was 8.8. Next, this jelly-like product was placed in a 0.5 mm-thick spacer, and both surfaces of the obtained solid polymer gel film 1 were sandwiched between platinum electrodes, and the ionic conductivity was measured. As a result, it was 0.8 S / m.

Comparative Example 1
A Nafion membrane (Nafion 112, film thickness 50 μm) was immersed in a polyacrylamide copolymer aqueous solution (Arakawa Chemical Industries, KW-387-20, 20% aqueous solution) at 60 ° C. for 100 hours, and then lightly washed with water. The ionic conductivity of this product was 0.0009 S / m. Further, the methanol permeation rate was 3.1 mg / cm ² / min. Thus, an effective methanol blocking property cannot be obtained simply by impregnating a membrane having a sulfonic acid group with a polymer having a basic group.

Comparative Example 2
1 part acrylic acid polymer aqueous solution (Arakawa Chemical Industries, HP-710, 30% aqueous solution) and 3 parts acrylamide polymer aqueous solution (Arakawa Chemical Industries, KW-387-20, 30% aqueous solution) ( Polymer concentration in the composition: 30%, ratio of acid / base equivalent number: 50/50) Kneading in a mortar. When kneaded, it became a colorless jelly-like product, and the pH value of a 0.2% aqueous solution of this jelly-like product was 6.9. Next, this jelly-like product was charged into a 0.2 mm thick spacer, and the ionic conductivity of the obtained solid polymer gel membrane 1 was measured. As a result, it was 0.002 S / m.

Comparative Example 3
14 parts of Nafion aqueous solution (manufactured by DuPont, SE-10072, 23% aqueous solution) and 1.5 parts of polyallylamine aqueous solution (manufactured by Nittobo, PAA05, 20% aqueous solution) (polymer concentration in the composition: 14.3) %, Ratio of acid / base equivalent number: 50/50) Kneading in a mortar. When kneaded, a white resinous material was obtained, and the pH value of a 0.2% aqueous solution of this resinous material was 7.3. Next, this resinous material was placed in a spacer having a thickness of 0.2 mm, and the ionic conductivity of the obtained solid polymer gel film was measured. As a result, it was 0.01 S / m.

Comparative Example 4
6 parts of an acrylic acid polymer aqueous solution (Arakawa Chemical Industries, Arafix 504, 2% aqueous solution) and 24 parts of acrylamide polymer aqueous solution (Arakawa Chemical Industries, Polystron 619, 7% aqueous solution) (composition) Polymer concentration: 6%, ratio of acid / base equivalent number: 50/50) Kneading in a mortar. When kneaded, almost no precipitate was formed. The pH value of the 0.2% aqueous solution of this composition was 7.21.

Example 25
20 parts of Nafion aqueous solution (DuPont, SE-10072, 11% aqueous solution) and 20 parts of polyacrylamide copolymer aqueous solution (Arakawa Chemical Industries, KW-387-20, 20% aqueous solution) (ratio of the number of acid-base equivalents: 60/40) and 7 parts of polytetrafluoroethylene (hereinafter referred to as PTFE) powder (Teflon (registered trademark) 6J manufactured by Mitsui DuPont Fluorochemical Co., Ltd.) (ionic polymer concentration in the composition: 48%) When kneaded in a mortar, a white putty-like composition was obtained. The putty-like composition was sandwiched between SUS plates and pressed to obtain a solid polymer electrolyte membrane 5 having a thickness of 100 μm. This was put into a hot air drying oven at 80 ° C. and dried. Both surfaces of the solid polymer electrolyte membrane 5 were sandwiched between platinum electrodes, and ionic conductivity was measured. As a result, it was 5 × 10 ⁻¹ S / m. The methanol permeation rate was 1 mg / cm ² / min.

Comparative Example 5
Performed as in Example 1 except that PTFE was not added. 20 parts of Nafion aqueous solution (DuPont, SE-10072, 11% aqueous solution) and 20 parts of polyacrylamide copolymer aqueous solution (Arakawa Chemical Industries, KW-387-20, 20% aqueous solution) (ratio of the number of acid-base equivalents) : 60/40) was kneaded in a mortar to give a white putty-like composition. The putty-like composition was sandwiched between SUS plates and pressed to obtain a solid polymer electrolyte membrane having a thickness of 100 μm. This was put in a hot air drying oven at 80 ° C. and dried, but it did not become a self-supporting film and was brittle.

Example 26
3 parts polyacrylic acid aqueous solution (Arakawa Chemical Industries, Polymerset HP-710, 30% aqueous solution) (acid / base equivalent ratio: 64/36) and polyallylamine aqueous solution (Nittobo, PAA- 10 parts of 10C, 10% aqueous solution), 1.5 parts of PTFE (ionic polymer concentration in the composition: 46%), and 6 parts of siloxane resin (X-12, 20% solution manufactured by Shin-Etsu Chemical Co., Ltd.) When kneaded inside, a white jelly-like composition was obtained. The jelly-like composition was sandwiched between SUS plates and pressed to obtain a solid polymer electrolyte membrane 5 having a thickness of 100 μm. This was put into a hot air drying oven at 80 ° C. and dried. Both sides of the solid polymer electrolyte membrane 5 were sandwiched between platinum electrodes, and ionic conductivity was measured. As a result, it was 2 × 10 ⁻¹ S / m. The methanol permeation rate was 0.5 mg / cm ² / min.

Example 27
10 parts of polyacrylic acid aqueous solution (manufactured by Dianitics, AP350M, 30% aqueous solution) and 1 part of polyallylamine aqueous solution (manufactured by Nitto Boseki, PAA10C, 10% aqueous solution) (ratio of acid-base equivalent number: 97/3), When 7 parts of PTFE (ionic polymer concentration in the composition: 28%) and 3 parts of acid type zeolite were kneaded in a mortar, a transparent jelly-like product was obtained. Next, the same operation as in Example 1 was performed to obtain a solid polymer electrolyte membrane 5 having a thickness of 100 μm. The ionic conductivity of the solid polymer electrolyte membrane 5 was 4 × 10 ⁻⁴ S / m. Moreover, the methanol permeation rate in a 30% aqueous methanol solution was 5.7 mg / cm ² / min.

Example 28
The Nafion aqueous solution of Example 1 was concentrated with an evaporator to obtain a 21% solution. 9.4 parts of this concentrated Nafion aqueous solution, 10 parts of polyacrylamide copolymer aqueous solution (Arakawa Chemical Industries, KW-387-20, 20% aqueous solution) (ratio of acid-base equivalent number: 60/40), and 7 parts of PTFE (Concentration of ionic polymer in composition: 36%) and 3 parts of acid-type zeolite were kneaded in a mortar. When kneaded, a white putty-like composition slightly harder than that obtained in Example 1 was obtained. The putty-like composition was sandwiched between SUS plates and pressed to obtain a solid polymer electrolyte membrane 5 having a thickness of 100 μm. This was put into a hot air drying oven at 80 ° C. and dried. Both surfaces of the solid polymer electrolyte membrane 5 were sandwiched between platinum electrodes, and ionic conductivity was measured. The ionic conductivity was 3.3 S / m. The methanol permeation rate was 0.9 mg / cm ² / min.

Example 29
5 parts of Nafion aqueous solution (DuPont, SE-10072, 5.5% aqueous solution) and 5 parts of polyacrylamide copolymer aqueous solution (Arakawa Chemical Industries, KW-387-20, 10% aqueous solution) (number of acid-base equivalents) Ratio of 60/40), 10 parts of PTFE (ionic polymer concentration in the composition: 7.2%), and 3 parts of acid-type zeolite were kneaded in a mortar. When kneaded, it turned into a white slightly soft bowl. Next, the same operation as in Example 1 was performed to obtain a solid polymer electrolyte membrane 5, and the ionic conductivity was measured. As a result, it was 1.5 × 10 ⁻³ S / m. The methanol transmission rate was 0.7 mg / cm ² / min.

Example 30
Nafion aqueous solution (DuPont, Lot No. SE-10072, 11% aqueous solution) 4 parts and polyacrylamide copolymer aqueous solution (Arakawa Chemical Industries, KW-387-20, 20% aqueous solution) 8 parts (acid base Equivalent number ratio: 43/57), 3 parts of PTFE (ionic polymer concentration in composition: 40%), and 3 parts of sulfonated pitch (see synthesis example above) were kneaded in a mortar. When kneaded, a black paste was formed. Subsequent operations were in accordance with Example 1. As a result of measuring the ionic conductivity of the obtained solid polymer electrolyte membrane 5, it was 2.0 S / m. The methanol transmission rate was 1.5 mg / cm ² / min.

Example 31
2.1 parts poly 2-acryloylamino-2-methyl-1-propanesulfonic acid aqueous solution (Toagosei Co., Ltd., Aron A-12SL, 40% aqueous solution) and 0.57 parts 50% polyacrylamide aqueous solution (acid-base equivalent) Number ratio: 50/50), 1.5 parts of PTFE (ionic polymer concentration in composition: 43%), and 1.5 parts of acid-type zeolite were kneaded in a mortar. When kneaded, a colorless soft jelly was obtained. Subsequent operations were in accordance with Example 1. As a result of measuring the ionic conductivity of the obtained solid polymer electrolyte membrane 5, it was 2.1 S / m. The methanol transmission rate was 1.1 mg / cm ² / min.

Example 32
7.6 parts of polyacid phosphooxyethyl methacrylate (product name: Phosmer M homopolymer, 11% IPA solution) and 0.57 part of 50% polyacrylamide aqueous solution (ratio of acid-base equivalent number: 50 / 50), 2.0 parts of polyvinyl chloride powder (ionic polymer concentration in the composition: 36%), 3 parts of a siloxane resin (X-12, 20% solution manufactured by Shin-Etsu Chemical Co., Ltd.), and dimethylformamide 2 And kneaded in a mortar. When kneaded, it became a colorless soft putty. Subsequent operations were in accordance with Example 1. As a result of measuring ionic conductivity of the obtained solid polymer electrolyte membrane 5, it was 8 × 10 ⁻¹ S / m. The methanol permeation rate was 0.5 mg / cm ² / min.

Example 33
A polyvinyl alcohol powder was used in place of the polyvinyl chloride powder in Example 8, and the others were performed in the same manner as in Example 8. When kneaded at 80 ° C., a black soft jelly was obtained. Subsequent operations were in accordance with Example 1. As a result of measuring the ionic conductivity of the obtained solid polymer electrolyte membrane 5, it was 4.0 S / m. The methanol transmission rate was 1.8 mg / cm ² / min.

Example 34
Composition in Example 8, ie, polyacid phosphooxyethyl methacrylate (trade name: Phosmer M homopolymer, 11% IPA solution), 7.6 parts, 50% polyacrylamide aqueous solution 0.57 parts (acid) Ratio of base equivalent number: 50/50), 2.0 parts of polyvinyl chloride powder (ionic polymer concentration in resin composition: 36%), siloxane resin (X-12, 20% solution manufactured by Shin-Etsu Chemical Co., Ltd.) 1 part by weight of t-butyl peroxybenzoate was added as a crosslinking agent to 3 parts and 2 parts of dimethylformamide. The obtained jelly-like composition was sandwiched between SUS plates and pressed to obtain a solid polymer electrolyte membrane 5 having a thickness of 100 μm. This was put into a hot air drying oven at 80 ° C. and dried. Furthermore, a crosslinking reaction was performed at 120 ° C. in a hot press machine, and a film-like solid polymer electrolyte membrane 5 was obtained. Both sides of this film were sandwiched between platinum electrodes, and the ionic conductivity was measured. As a result, it was 2 × 10 ⁻¹ S / m. The methanol permeation rate was 0.9 mg / cm ² / min.

  The results of Examples and Comparative Examples are summarized in Tables 1 to 4.

  As described above, the ion conductive solid polymer electrolyte, the solid polymer electrolyte membrane 5, the solid polymer gel membrane 1, and the solid formed by sandwiching the solid polymer gel membrane 1 between the porous membranes according to the present invention. Polymer electrolyte membranes are fuel cells, ion conducting membranes for solid polymer electrolyte fuel cells, redox cells, electrodialysis membranes, reverse osmosis membranes, nanofiltration membranes, diffusion dialysis membranes, gas separation membranes, pervaporation and osmotic extraction. Since it is used in the fields of membranes, humidity sensors, and gas sensors, and has a very low methanol permeability and is used as an electrolyte membrane for DMFC, it is industrially useful.

It is a side view which shows an example of the solid polymer electrolyte membrane of this invention. It is a side view which shows an example of a fuel cell provided with the solid polymer gel film | membrane of this invention. It is a side view which shows an example of a fuel cell provided with the solid polymer electrolyte membrane of this invention. It is a side view which shows the other example of a fuel cell provided with the solid polymer electrolyte membrane of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Solid polymer gel film 2 ... Porous membrane 3a ... Positive electrode 3b ... Negative electrode 4 ... Gas diffusion layer 5 ... Solid polymer electrolyte membrane

Claims (20)

A solid polymer electrolyte containing a composition obtained by mixing a polymer solution having an acidic group and a polymer solution having a basic group,
The polymer having an acidic group is an aliphatic polymer having in the side chain at least one selected from the group consisting of a sulfonic acid group, a phosphonic acid group, and a carboxyl group;
A solid polymer electrolyte, wherein the basic polymer is an aliphatic polymer or an aromatic polymer having at least one selected from the group consisting of an amino group, an amide group, and a urea group in a main chain or a side chain.   The solid polymer electrolyte according to claim 1, wherein the composition has a pH value of 0 or more and 6 or less, or 8 or more and 14 or less.   The solid polymer electrolyte according to claim 1, wherein the ratio of the number of functional group equivalents of the polymer having an acidic group and the polymer having a basic group is 20/80 to 80/20.   The solid polymer electrolyte according to claim 1, wherein the polymer content is 10 to 90% by weight.   The polymer having acidic groups is polyperfluorocarbon sulfonic acid, polyacrylamide methylpropane sulfonic acid, polyacid phosphooxyethyl methacrylate, poly (meth) acrylic acid, polystyrene sulfonic acid, or isobutylene maleic anhydride copolymer. 1. The solid polymer electrolyte according to 1.   The polymer having the basic group is polyacrylamide, polyallylamine, polydimethylaminoethyl (meth) acrylate, aminopolyacrylamide, polyaminosulfone, polyvinylpyridine, polyvinylpyrrolidone, polyvinylcaprolactam, polyvinylcarbazole, polyvinyldiaminotriazine, or polyethyleneimine The solid polymer electrolyte according to claim 1.   The solid polymer electrolyte according to claim 1, further comprising a filler.   The solid polymer electrolyte according to claim 7, wherein the filler is a siloxane resin, sulfonated pitch, sulfonated carbon, montmorillonite, or acidic zeolite.   The solid polymer electrolyte according to claim 7, wherein the filler is added in an amount of 5 to 300 parts by weight with respect to 100 parts by weight of the polymer content in the solid polymer electrolyte.   And a matrix polymer, which is a polyolefin, halogenated polyolefin, polyvinyl alcohol, polystyrene, polyimide, polybenzimidazole, polyoxazole, polycarbonate, polyparavinylphenol, polyethylene oxide, polyphenylene oxide, and derivatives thereof. The solid polymer electrolyte according to claim 1, comprising at least one selected from the group consisting of:   The solid polymer electrolyte according to claim 10, wherein the total content of the polymer having an acidic group and the polymer having a basic group is 5 to 90% by weight.   The matrix polymer is polytetrafluoroethylene, polyvinyl chloride, polyvinyl chloride copolymer, styrene-acrylonitrile copolymer, vinyl acetate-vinyl pyridine copolymer, polyethylene, polyethylene-vinyl alcohol copolymer, polypropylene, polychlorinated. The solid polymer electrolyte according to claim 10, which is vinylidene or an ethylenetetrafluoroethylene copolymer.   Furthermore, it is a solid polymer electrolyte containing a crosslinking agent, Comprising: The solid polymer electrolyte of Claim 10 obtained by making it bridge | crosslink with a heat | fever, light, or an electron beam.   A solid polymer gel film formed by forming the solid polymer electrolyte according to claim 1.   A solid polymer electrolyte membrane comprising the solid polymer gel membrane according to claim 14 sandwiched between porous membranes.   The solid polymer electrolyte membrane according to claim 15, wherein the porous membrane has a Gurley value of 100 seconds / 100 ml or less.   A solid polymer electrolyte membrane formed by forming the solid polymer electrolyte according to claim 10.   A fuel cell comprising the solid polymer gel film according to claim 14 and a positive electrode and a negative electrode sandwiching the solid polymer gel film.   A fuel cell comprising the solid polymer electrolyte membrane according to claim 15, and a positive electrode and a negative electrode sandwiching the solid polymer electrolyte membrane.   A fuel cell comprising: the solid polymer electrolyte membrane according to claim 17; and a positive electrode and a negative electrode sandwiching the solid polymer electrolyte membrane.

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