WO2009145188A1 - Electrolyte membrane - Google Patents

Electrolyte membrane Download PDF

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Publication number
WO2009145188A1
WO2009145188A1 PCT/JP2009/059605 JP2009059605W WO2009145188A1 WO 2009145188 A1 WO2009145188 A1 WO 2009145188A1 JP 2009059605 W JP2009059605 W JP 2009059605W WO 2009145188 A1 WO2009145188 A1 WO 2009145188A1
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WO
WIPO (PCT)
Prior art keywords
electrolyte
monomer
electrolyte membrane
porous body
monomer solution
Prior art date
Application number
PCT/JP2009/059605
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French (fr)
Japanese (ja)
Inventor
高見　昌宜
利彦 吉田
昌宏 植田
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トヨタ自動車株式会社
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Publication of WO2009145188A1 publication Critical patent/WO2009145188A1/en

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    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
    • C08J5/20—Manufacture of shaped structures of ion-exchange resins
    • C08J5/22—Films, membranes or diaphragms
    • C08J5/2206—Films, membranes or diaphragms based on organic and/or inorganic macromolecular compounds
    • C08J5/2218—Synthetic macromolecular compounds
    • C08J5/2231—Synthetic macromolecular compounds based on macromolecular compounds obtained by reactions involving unsaturated carbon-to-carbon bonds
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
    • H01B1/06—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors mainly consisting of other non-metallic substances
    • H01B1/12—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors mainly consisting of other non-metallic substances organic substances
    • H01B1/122—Ionic conductors
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/02—Details
    • H01M8/0289—Means for holding the electrolyte
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/10—Fuel cells with solid electrolytes
    • H01M8/1016—Fuel cells with solid electrolytes characterised by the electrolyte material
    • H01M8/1018—Polymeric electrolyte materials
    • H01M8/102—Polymeric electrolyte materials characterised by the chemical structure of the main chain of the ion-conducting polymer
    • H01M8/1023—Polymeric electrolyte materials characterised by the chemical structure of the main chain of the ion-conducting polymer having only carbon, e.g. polyarylenes, polystyrenes or polybutadiene-styrenes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/10—Fuel cells with solid electrolytes
    • H01M8/1016—Fuel cells with solid electrolytes characterised by the electrolyte material
    • H01M8/1018—Polymeric electrolyte materials
    • H01M8/1058—Polymeric electrolyte materials characterised by a porous support having no ion-conducting properties
    • H01M8/106—Polymeric electrolyte materials characterised by a porous support having no ion-conducting properties characterised by the chemical composition of the porous support
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/10—Fuel cells with solid electrolytes
    • H01M8/1016—Fuel cells with solid electrolytes characterised by the electrolyte material
    • H01M8/1018—Polymeric electrolyte materials
    • H01M8/1069—Polymeric electrolyte materials characterised by the manufacturing processes
    • H01M8/1072—Polymeric electrolyte materials characterised by the manufacturing processes by chemical reactions, e.g. insitu polymerisation or insitu crosslinking
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2335/00—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a carboxyl radical, and containing at least one other carboxyl radical in the molecule, or of salts, anhydrides, esters, amides, imides or nitriles thereof; Derivatives of such polymers
    • C08J2335/08—Copolymers with vinyl ethers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2300/00—Electrolytes
    • H01M2300/0017—Non-aqueous electrolytes
    • H01M2300/0065—Solid electrolytes
    • H01M2300/0082—Organic polymers
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/30—Hydrogen technology
    • Y02E60/50—Fuel cells
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

  • the present invention relates to an electrolyte membrane having high ion exchange capacity retention, excellent adhesion between an electrolyte and a porous body, and improved proton conductivity.
  • a unit cell which is a minimum power generation unit of a solid polymer electrolyte fuel cell (hereinafter sometimes referred to simply as a fuel cell), generally has a catalyst electrode layer (an anode side catalyst electrode layer and a cathode side catalyst) on both sides of a solid electrolyte membrane. It has a membrane electrode assembly (MEA: Electrode Assembly) to which an electrode layer is bonded, and gas diffusion layers are arranged on both sides of this membrane electrode assembly. Furthermore, a separator having a gas flow path is arranged outside thereof, and the fuel gas and the oxidant gas supplied to the catalyst electrode layer of the membrane electrode composite are passed through the gas diffusion layer, It works to transmit the current obtained by power generation to the outside.
  • MEA Electrode Assembly
  • a method of humidifying the fuel gas and supplying water into the fuel cell is widely used.
  • a device that humidifies the fuel gas is a heavy object, which causes a reduction in fuel consumption, a reduction in vehicle space, an increase in cost, and the like.
  • the temperature of the fuel battery cell is preferably about 40 to 80 ° C. from the viewpoint of reaction efficiency, usually, cooling water is introduced into the cell to suppress the temperature rise caused by the battery reaction.
  • cooling requires a heavy device such as a cooling fan and a radiator, which also causes a reduction in fuel consumption, a reduction in in-vehicle space, and an increase in cost.
  • Patent Document 1 discloses an electrolyte membrane obtained by impregnating a porous material with a sulfonic acid group-containing vinyl monomer and a cross-linking agent.
  • the present invention has been made in view of the above problems, and provides an electrolyte membrane having high ion exchange capacity retention, excellent adhesion between an electrolyte and a porous body, and improved battery characteristics. This is the main purpose.
  • an electrolyte obtained by polymerizing at least a sulfonic acid group-containing vinyl monomer and a hydrophilic unit-containing polyfunctional crosslinking monomer having an HLB value of 5.0 or more is the above electrolyte.
  • the synthesis of the electrolyte is improved and the crosslinked structure in the electrolyte can be stabilized. It becomes. Thereby, the retainability of the ion exchange capacity can be increased.
  • the skeleton structure of the porous body the same as the main chain skeleton structure of the electrolyte, it becomes possible to increase the affinity between the electrolyte and the porous body, It is possible to improve the adhesion. For this reason, the electrolyte membrane which has a favorable battery characteristic can be obtained, without gas barrier property falling.
  • the sulfonic acid group-containing vinyl monomer is preferably vinyl sulfonic acid
  • the hydrophilic unit-containing polyfunctional crosslinking monomer is preferably polyethylene glycol diacrylate. This is because the crosslinked structure in the electrolyte can be effectively made stable and good.
  • the electrolyte is preferably obtained by polymerizing only the sulfonic acid group-containing vinyl monomer and the hydrophilic unit-containing polyfunctional crosslinking monomer having an HLB value of 5.0 or more. This is because the proton conductivity in the electrolyte can be made better.
  • the porous body preferably has a vinyl skeleton structure. This is because the affinity between the electrolyte and the porous body can be effectively increased and higher battery characteristics can be maintained.
  • the ion exchange capacity of the electrolyte membrane is preferably 3.0 meq / g or more. It is because it can be set as the electrolyte membrane excellent in proton conductivity.
  • an electrolyte obtained by polymerizing the monomer solution in a monomer solution containing at least a sulfonic acid group-containing vinyl monomer and a hydrophilic unit-containing polyfunctional crosslinking monomer having an HLB value of 5.0 or more.
  • a method for producing an electrolyte membrane comprising: a monomer solution impregnation step for impregnating the monomer solution to obtain a monomer solution-impregnated porous body; and a polymerization step for polymerizing the monomer solution to obtain an electrolyte membrane.
  • the monomer solution can be effectively impregnated in the porous body, and the monomer solution is effective in the porous body.
  • the monomer solution can be polymerized in a state of being impregnated.
  • both the sulfonic acid group-containing vinyl monomer and the hydrophilic unit-containing polyfunctional crosslinking monomer are hydrophilic, the sulfonic acid group-containing vinyl monomer and the hydrophilic unit-containing polyfunctional monomer in the monomer solution are used. It becomes possible to uniformly disperse the crosslinking monomer. For this reason, it is possible to obtain an electrolyte membrane having high ion exchange capacity retention, excellent adhesion between the electrolyte and the porous body, and improved proton conductivity.
  • FIG. 2 is a graph in which the ion exchange capacity before and after the hydrothermal test of an electrolyte membrane formed by changing only the PEGDA content of the electrolyte membrane obtained in Example 1 is plotted against the PEGDA content.
  • 6 is a graph in which the ion exchange capacity before and after the hydrothermal test of an electrolyte membrane formed by changing only the PEGDA content of the electrolyte membrane obtained in Example 2 is plotted against the PEGDA content.
  • electrolyte membrane of the present invention and the method for producing the electrolyte membrane will be described in detail below.
  • an electrolyte obtained by polymerizing at least a sulfonic acid group-containing vinyl monomer and a hydrophilic unit-containing polyfunctional crosslinking monomer having an HLB value of 5.0 or more is the same as the main chain skeleton structure of the electrolyte. It is characterized by being impregnated in a porous body having the skeleton structure.
  • the hydrophilic unit-containing polyfunctional crosslinking monomer by setting the HLB value of the hydrophilic unit-containing polyfunctional crosslinking monomer to 5.0 or more, for example, when water is used as a solvent, the hydrophilic unit-containing polyfunctional crosslinking monomer is uniformly distributed. Can be dissolved in the above solvent. Thereby, the reactivity with the said sulfonic acid group containing vinyl monomer with high solubility with respect to water similarly can be made favorable. For this reason, the crosslinked structure in the electrolyte formed by polymerizing these is uniformly formed in the electrolyte, and becomes stable and good.
  • the electrolyte even after the electrolyte is subjected to a hydrothermal test or the like, it is possible to suppress a decrease in ion exchange groups, and the ion exchange capacity (the amount of ion exchange groups per 1 g of dry ion exchange membrane (meq / G)) can be improved.
  • the ion exchange capacity the amount of ion exchange groups per 1 g of dry ion exchange membrane (meq / G)
  • the affinity between the electrolyte and the porous body can be increased. For this reason, it becomes possible to make the adhesiveness of the said electrolyte and the said porous body excellent, and peeling etc. between the said electrolyte and the said porous body can be suppressed.
  • the electrolyte membrane of the present invention is not particularly limited as long as it has at least the electrolyte and the porous body.
  • the electrolyte membrane of the present invention will be described in detail for each configuration.
  • the electrolyte in the present invention is obtained by polymerizing at least a sulfonic acid group-containing vinyl monomer and a hydrophilic unit-containing polyfunctional crosslinking monomer having an HLB value of 5.0 or more.
  • both of the sulfonic acid group-containing vinyl monomer and the hydrophilic unit-containing polyfunctional crosslinking monomer having an HLB value of 5.0 or more are hydrophilic.
  • the cross-linked structure in the electrolyte obtained by polymerization is uniformly formed in the electrolyte and becomes stable and good, and it is possible to suppress the reduction of ion exchange groups and increase the retention of ion exchange capacity. Can do.
  • Such an electrolyte is not particularly limited as long as it is formed by polymerizing at least the sulfonic acid group-containing vinyl monomer and the hydrophilic unit-containing polyfunctional crosslinking monomer as described above. It may be formed by polymerization in a state having the monomer.
  • the hydrophilic unit-containing polyfunctional crosslinking monomer, the sulfonic acid group-containing vinyl monomer, other monomers, and the electrolyte (electrolyte polymer) obtained by polymerizing the monomer will be described in detail.
  • the hydrophilic unit-containing polyfunctional crosslinking monomer in the present invention is a polyfunctional monomer having an HLB value of 5.0 or more and having at least a hydrophilic unit and a functional group such as a vinyl group.
  • a hydrophilic unit-containing polyfunctional crosslinking monomer excellent in hydrophilicity for example, when water is used as a solvent, the hydrophilic unit-containing polyfunctional crosslinking monomer is uniformly mixed with the above-mentioned hydrophilic unit-containing polyfunctional crosslinking monomer.
  • the cross-linked structure is uniformly formed in the electrolyte, and becomes stable and good.
  • the HLB (Hydrophile-Lipophile Balance) value usually takes a value from 0 to 20, and the closer to 0, the higher the lipophilicity, and the closer to 20, the higher the hydrophilicity.
  • HLB value 20 ⁇ total formula weight of hydrophilic part / molecular weight.
  • polyethylene glycol diacrylate has an HLB value (Griffin method) of 6.16
  • methylene bisacrylamide has 3.96.
  • the hydrophilic unit-containing polyfunctional crosslinking monomer has an HLB value of 5.0 or more.
  • the HLB value is preferably in the range of 5.0 to 15.0, particularly in the range of 5.0 to 10.0.
  • the hydrophilic unit-containing polyfunctional crosslinking monomer has a hydrophilicity represented by an HLB value within the above range, so that the solubility in water or the like can be increased. As described above, a uniform cross-linked structure is formed, and the cross-linked structure can be improved.
  • the hydrophilic unit-containing polyfunctional crosslinking monomer is not particularly limited as long as it has a HLB value of 5.0 or more and has at least a hydrophilic unit and a functional group such as a vinyl group.
  • the hydrophilic unit in the hydrophilic unit-containing polyfunctional crosslinking monomer is not particularly limited as long as the HLB value can be 5.0 or more.
  • Examples thereof include polyether units represented by the formula (1) and sulfonated compounds. Among these, a polyether unit represented by the following formula (1) is preferable. This is because the mechanical strength of the electrolyte can be improved.
  • the carbon number m in the polyether unit is usually in the range of 2 to 3.
  • polyethylene glycol having 2 carbon atoms is preferable.
  • the number n of repeating units in the polyether-based unit is preferably in the range of 2 to 4, more preferably 2.
  • the functional group in the hydrophilic unit-containing polyfunctional crosslinking monomer it is possible to form a stable and good crosslinked structure as described above by polymerization and obtain the desired electrolyte.
  • a conjugated vinyl group is preferable. This is because the electrolyte can be obtained under high reaction conditions under mild reaction conditions.
  • hydrophilic unit-containing polyfunctional crosslinking monomer examples include polyethylene glycol diacrylate, polypropylene glycol diacrylate, and divinylbenzenesulfonic acid represented by the following formula (2).
  • polyethylene glycol diacrylate represented by the following formula (2) is preferable. This is because the crosslinked structure in the electrolyte can be made more effective.
  • n in the formula (2) is the same as described above.
  • the ratio of the hydrophilic unit-containing polyfunctional crosslinking monomer to the sulfonic acid group-containing vinyl monomer described later is not particularly limited as long as the desired electrolyte can be obtained.
  • the electrolyte is obtained by polymerizing only polyethylene glycol diacrylate (hydrophilic unit-containing polyfunctional crosslinking monomer) and vinylsulfonic acid (sulfonic acid group-containing vinyl monomer) described later, the hydrophilicity described above.
  • Weight% of unit-containing polyfunctional crosslinking monomer weight based on the total weight of the hydrophilic unit-containing polyfunctional crosslinking monomer and the sulfonic acid group-containing vinyl monomer weight of hydrophilic unit-containing polyfunctional crosslinking monomer / (hydrophilic unit-containing polyfunctional Cross-linking monomer weight + sulfonic acid group-containing vinyl mono Is over weight) ⁇ 100
  • 15 wt% or more the range among them of 20% to 80% by weight, particularly preferably in the range of 25 wt% to 70 wt%.
  • the sulfonic acid group-containing vinyl monomer in the present invention is a vinyl monomer having a sulfonic acid group (—SO 3 H) and is hydrophilic.
  • a crosslinked structure in the electrolyte obtained by polymerizing at least the sulfonic acid group-containing vinyl monomer and the hydrophilic unit-containing polyfunctional crosslinking monomer is used as the electrolyte. It can be formed uniformly in the inside, and can be made stable and satisfactory.
  • the sulfonic acid group-containing vinyl monomer used in the present invention is a vinyl monomer having a sulfonic acid group and is not particularly limited as long as it is hydrophilic, but preferably has a smaller molecular weight. This is because the weight fraction of the sulfonic acid group in the sulfonic acid group-containing vinyl monomer can be increased, and the ion exchange capacity of the electrolyte can be improved.
  • Examples of such sulfonic acid group-containing vinyl monomers include vinyl sulfonic acid represented by the following formula (3), acrylamide n-butyl sulfonic acid, and styrene sulfonic acid.
  • vinyl sulfonic acid is preferable. This is because the ion exchange capacity of the electrolyte can be effectively improved.
  • sulfonic acid group-containing vinyl monomer in the present invention may be used, or a plurality of types may be used.
  • the electrolyte in the present invention is polymerized in a state having other monomers. Also good. As such other monomers, it is possible to obtain the electrolyte membrane having high ion exchange capacity retention and excellent adhesion between the electrolyte and the porous body, and having a certain degree of hydrophilicity. There is no particular limitation as long as it is present.
  • the HLB value of such other monomers is preferably 5 or more, particularly preferably in the range of 5-15.
  • acrylamide polyethylene glycol monoacrylate, polypropylene glycol monoacrylate, morpholino acrylate, dimethylaminopropyl acrylamide, acrylic acid, methacrylic acid, phosphate ester acrylate, ethyl vinyl sulfonate, vinyl ethyl ether, vinyl methyl ether, Examples thereof include vinyl acetate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate and the like.
  • a monomer having hydrophobicity it is not preferable to use a monomer having hydrophobicity.
  • those having an HLB value of 4 or less, particularly those in the range of 0 to 3.5 are not preferred in the present invention.
  • Specific examples include methyl methacrylate, neopentyl alcohol diacrylate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, styrene, chloromethylstyrene, divinylbenzene, and the like. This is because it is difficult to make the crosslinked structure in the electrolyte stable and good, and there is a risk that the retention of the ion exchange capacity and the like may be reduced.
  • Electrolyte polymer is particularly limited as long as it is obtained by polymerizing at least a sulfonic acid group-containing vinyl monomer and a hydrophilic unit-containing polyfunctional crosslinking monomer having an HLB value of 5.0 or more.
  • the electrolyte is a hydrophilic monomer having a sulfonic acid group-containing vinyl monomer and an HLB value of 5.0 or more. It is preferable that only the functional unit-containing polyfunctional crosslinking monomer is polymerized.
  • an electrolyte polymer represented by the following formula (4) obtained by polymerizing only vinyl sulfonic acid and polyethylene glycol diacrylate can be given.
  • k represents the number of units of the hydrophilic unit, which is the same as n in the above formula (2), so the description here is omitted.
  • i and j are each preferably in the range of, for example, 500 to 10,000, and more preferably in the range of 1,000 to 10,000.
  • the molecular weight determined here is preferably as high as possible. The upper limit is considered to be 10,000 in consideration of the implementation status, but may be more than that.
  • the porous body used in the present invention has the same skeleton structure as the main chain skeleton structure of the electrolyte, and impregnates the electrolyte.
  • the skeleton structure of the porous body and the main chain skeleton structure of the electrolyte are the same, the affinity between the electrolyte and the porous body is increased, and the electrolyte and the porous body are improved. It becomes possible to make the adhesiveness with a body excellent, and peeling between the electrolyte and the porous body can be suppressed. As a result, it is possible to prevent problems such as deterioration of gas barrier properties.
  • the porous body in the present invention may be impregnated with the electrolyte, and the skeleton structure of the porous body may be the same as the main chain skeleton structure of the electrolyte described above, and is particularly limited. It is not a thing.
  • those having a vinyl skeleton structure those containing fluorine such as PTFE (polytetrafluoroethylene), polyacrylonitrile, polystyrene, styrene / maleic anhydride copolymer, acrylonitrile / butadiene / styrene copolymer, polyvinyl alcohol And polyvinyl acetate, partially saponified polyvinyl acetate, and polyvinyl chloride.
  • the material having a vinyl skeleton structure examples include polyethylene, polypropylene, an ethylene / vinyl acetate copolymer, and an ethylene / methyl methacrylic acid copolymer.
  • polyethylene is preferable.
  • the ion exchange capacity of the electrolyte membrane is preferably 3.0 meq / g or more. In particular, it is preferably in the range of 3.0 to 6.0, particularly in the range of 4.0 to 5.0. It is because it can be set as the electrolyte membrane excellent in proton conductivity.
  • the use of the electrolyte membrane obtained by the present invention is not particularly limited.
  • a membrane electrode assembly including the electrolyte membrane and electrodes (anode and cathode) disposed on both sides of the electrolyte. It can be used as a fuel cell or the like in which a gas diffusion layer is disposed on both sides of the membrane electrode assembly and a separator having a gas flow path is disposed on the outside thereof.
  • an electrolyte membrane used for a membrane electrode assembly for automobiles, a fuel cell, and the like can be the same as those normally used, and description thereof is omitted here.
  • any method can be used as long as it is a production method capable of obtaining an electrolyte membrane having high ion exchange capacity retention, excellent adhesion between the electrolyte and the porous body, and improved proton conductivity. It is not limited. For example, the method etc. which are described later in "B. Manufacturing method of electrolyte membrane" can be mentioned.
  • the method for producing an electrolyte membrane of the present invention comprises polymerizing the monomer solution in a monomer solution containing at least a sulfonic acid group-containing vinyl monomer and a hydrophilic unit-containing polyfunctional crosslinking monomer having an HLB value of 5.0 or more.
  • It comprises a monomer solution impregnation step for impregnating the monomer solution into a body to obtain a monomer solution-impregnated porous body, and a polymerization step for polymerizing the monomer solution to obtain an electrolyte membrane.
  • the monomer solution can be effectively impregnated in the porous body, and the monomer solution is effective in the porous body.
  • the monomer solution can be polymerized in a state of being impregnated.
  • the hydrophilic unit-containing polyfunctional crosslinking monomer is uniformly contained in the solvent. It is possible to dissolve the sulfonic acid group-containing vinyl monomer having a high solubility in water.
  • the affinity between the electrolyte and the porous body is high, and the adhesion between the electrolyte and the porous body can be made excellent. Separation and the like can be suppressed. Furthermore, the crosslinked structure in the electrolyte is stable and good, and even after a hot water test or the like, it is possible to suppress a decrease in ion exchange groups, and it is possible to increase the retention of ion exchange capacity. . Accordingly, it is possible to prevent the gas barrier property from being lowered, and an electrolyte membrane having improved battery characteristics can be obtained.
  • an electrolyte membrane is obtained by performing the following steps along the electrolyte membrane formation flowchart illustrated in FIG. be able to. For example, first, a predetermined amount of a sulfonic acid group-containing vinyl monomer, a hydrophilic unit-containing polyfunctional crosslinking monomer having an HLB value of 5.0 or more, a radical polymerization initiator, and a solvent are added to a container and mixed. Prepare a monomer solution. Next, the porous body having the same skeleton structure as the main chain skeleton structure of the electrolyte obtained by polymerizing the monomer solution is immersed in the ice-cooled monomer solution.
  • the container is covered, depressurized with an aspirator or the like, a deaeration process for inducing the monomer solution into the pores of the porous body is performed, and deaeration is performed for a predetermined time. Thereafter, the aspirator is stopped, air is sent into the container, and a deaeration process for returning to normal pressure is performed.
  • the container is opened, and the porous body is impregnated with the monomer solution by applying and releasing mechanical pressure while the porous body is immersed in the ice-cooled monomer solution. Then, a monomer solution impregnation step for obtaining a monomer solution-impregnated porous body is performed.
  • the monomer solution impregnated porous body obtained in the monomer solution impregnation step is taken out of the container, and a monomer solution removal step for removing the monomer solution adhering to the surface of the monomer solution impregnated porous body is performed.
  • a lid is attached to the container, the inside of the container is depressurized with a vacuum pump or the like, and returned to normal pressure with nitrogen, thereby replacing the nitrogen in the container.
  • the electrolyte membrane can be obtained by performing a polymerization process in which the container is placed in a constant temperature bath or the like at a predetermined temperature, heated for a predetermined time, and subjected to a polymerization reaction. After the reaction, the whole container is cooled to room temperature by cooling, etc., and then the electrolyte membrane obtained by opening the container is taken out.
  • the method for producing an electrolyte membrane of the present invention is not particularly limited as long as it has at least the monomer solution impregnation step and the polymerization step, and includes other steps such as the deaeration step described above. You may have.
  • each process in the manufacturing method of the electrolyte membrane of this invention is demonstrated in detail.
  • the monomer solution impregnation step in the present invention is a polymerization of the monomer solution in a monomer solution containing at least a sulfonic acid group-containing vinyl monomer and a hydrophilic unit-containing polyfunctional crosslinking monomer having an HLB value of 5.0 or more.
  • a porous body having the same skeleton structure as the main chain skeleton structure of the electrolyte and suppressing the polymerization reaction mechanical pressure is applied to and released from the porous body.
  • the monomer solution is impregnated in the body to obtain a monomer solution-impregnated porous body.
  • the monomer solution used in this step contains at least a sulfonic acid group-containing vinyl monomer and a hydrophilic unit-containing polyfunctional crosslinking monomer having an HLB value of 5.0 or more.
  • the sulfonic acid group-containing vinyl monomer and the hydrophilic unit-containing polyfunctional crosslinking monomer contained in the monomer solution are the same as those described in “A. Electrolyte membrane 1. Electrolyte” described above. Explanation here is omitted.
  • the monomer solution may further contain other monomers in addition to the sulfonic acid group-containing vinyl monomer and the hydrophilic unit-containing polyfunctional crosslinking monomer. Such other monomers are the same as those described in the above-mentioned “A. Electrolyte membrane 1. Electrolyte”, and thus description thereof is omitted here.
  • the monomer solution can be formed using a predetermined solvent by adding the sulfonic acid group-containing vinyl monomer, the hydrophilic unit-containing polyfunctional crosslinking monomer, other monomers, and the like to the solvent.
  • the solvent is not particularly limited as long as it can dissolve the sulfonic acid group-containing vinyl monomer, the hydrophilic unit-containing polyfunctional crosslinking monomer, other monomers, and the like, and can obtain the desired monomer solution. There is no particular limitation.
  • water, methanol, DMF, NMP, HMPA especially water Is preferred.
  • the monomer solution since a monomer solution having a high density of sulfonic acid groups is usually used, extremely high hydrophilicity is required as the solvent.
  • the monomer solution may be prepared by mixing the sulfonic acid group-containing vinyl monomer, the hydrophilic unit-containing polyfunctional crosslinking monomer, other monomers, etc. without using the solvent. good.
  • the monomer solution usually contains a polymerization initiator used for initiating polymerization in the polymerization step described later.
  • the polymerization initiator varies depending on the type of the solvent and can be appropriately selected according to the type of the solvent. For example, an azo compound, an organic peroxide, etc. can be mentioned.
  • the porous body used in this step has the same skeleton structure as the main chain skeleton structure of the electrolyte obtained by polymerizing the monomer solution, and impregnates the monomer solution.
  • the details of the porous body are the same as those described in “A. Electrolyte membrane 2. Porous body” described above, and thus the description thereof is omitted here.
  • the porous body is impregnated with the monomer solution by immersing the porous body in the monomer solution and suppressing the polymerization reaction.
  • the method is not particularly limited as long as it is a method of impregnation by applying and releasing pressure.
  • a method for applying and releasing the mechanical pressure for example, as shown in FIG. 2, the porous body 2 is immersed in a cooled monomer solution 1 and the porous body 2 is predetermined by a roller 3 or the like.
  • a method of moving in a predetermined direction as indicated by an arrow in FIG. Further, as shown in FIG.
  • a predetermined pressure is applied to and released from the porous body 2 immersed in the cooled monomer solution 1 and placed on the pressing plate 4 by the pressing device 5 or the like.
  • the method of performing etc. can be mentioned.
  • the application and release of the mechanical pressure described above can be performed only once. It may be repeated several times.
  • a method of cooling the monomer solution in a container containing the monomer solution with ice can be exemplified.
  • a method of cooling by blowing low temperature inert gas (for example, low temperature nitrogen gas or low temperature argon gas) directly on the porous body may be used.
  • the polymerization step in the present invention is a step of obtaining an electrolyte membrane by performing polymerization using the monomer solution-impregnated porous material obtained in the monomer solution impregnation step.
  • the polymerization method for carrying out the polymerization using the monomer solution-impregnated porous body is not particularly limited as long as it can obtain the desired electrolyte membrane with improved proton conductivity. is not.
  • a monomer solution removing step for removing an excess monomer solution adhering to the surface of the monomer solution impregnated porous body obtained in the monomer solution impregnating step is performed, and then placed in a container. After this, the container is fitted with a lid, the inside of the container is depressurized with a vacuum pump, and returned to normal pressure with nitrogen, so that the inside of the container is replaced with nitrogen, and further, the above containers are installed in a constant temperature bath at a predetermined temperature. And a method of heating for a predetermined time.
  • the conditions for the polymerization for example, the gas atmosphere at the time of gas substitution, the temperature and time for the polymerization, etc. are not particularly limited as long as the desired electrolyte membrane can be obtained. It can be set as appropriate by conducting a preliminary experiment.
  • the method for producing an electrolyte membrane of the present invention is not particularly limited as long as it has at least the monomer solution impregnation step and the polymerization step.
  • the monomer solution impregnation step and the polymerization step You may have the deaeration process etc. which were mentioned above.
  • each process of a deaeration process and another process is demonstrated in detail.
  • the deaeration process in this invention is demonstrated.
  • the degassing step in the present invention is a step of degassing the porous body immersed in the monomer solution by reducing the pressure to induce the monomer solution into the pores of the porous body. This step may be performed before the monomer solution impregnation step, or may be performed using the monomer solution impregnated porous body after the monomer solution impregnation step. Usually, it is performed before the monomer solution impregnation step.
  • the monomer solution can be more effectively impregnated into the pores of the porous body.
  • any method can be used as long as it can degas from a porous body immersed in a monomer solution by reducing the pressure to induce the monomer solution into the pores of the porous material. It is not limited.
  • a predetermined amount of an initiator and a solvent are added and mixed to prepare a monomer solution.
  • the porous body is immersed in an ice-cooled monomer solution.
  • a method of covering the vessel and reducing the pressure with an aspirator to induce the monomer solution into the pores of the porous body can be exemplified. Further, for example, when this step is performed after the monomer solution impregnation step, after the monomer solution impregnation step is finished, the monomer solution impregnated porous body is immersed in the monomer solution, As described above, a method of reducing the pressure using an aspirator can be exemplified.
  • the degassing conditions such as the time during which the inside of the container is depressurized, are not particularly limited as long as the conditions allow desired degassing, and may be set as appropriate by conducting a preliminary experiment. Can do.
  • the monomer solution removal step in the present invention is a step of removing unnecessary residual monomer solution on the surface of the monomer solution-impregnated porous body using a blade or the like, and usually after the monomer solution impregnation step, It is carried out before the polymerization step. By passing through this step, a better electrolyte membrane can be obtained.
  • electrolyte membrane obtained by the present invention is the same as that described in the above-mentioned “A. Electrolyte membrane”, and thus the description thereof is omitted here.
  • the present invention is not limited to the above embodiment.
  • the above-described embodiment is an exemplification, and the present invention has substantially the same configuration as the technical idea described in the claims of the present invention, and any device that exhibits the same function and effect is the present invention. It is included in the technical scope of the invention.
  • Example 1 (Monomer solution impregnation porous body formation)
  • VSA-H vinyl sulfonic acid
  • PEGDA polyethylene glycol diacrylate
  • HLB value 6. 16
  • V-501 a water-soluble radical polymerization initiator
  • a 5 cm square polyethylene porous membrane (Solpore 16PO5A) was immersed in the monomer solution cooled with ice in the separable flask.
  • a lid of a separable flask was attached, the inside of the flask was depressurized with an aspirator, and a deaeration process for inducing the monomer solution into the pores of the porous membrane was performed.
  • the deaeration treatment was performed for about 3 minutes, the aspirator was stopped, air was sent into the flask, and the pressure was returned to normal pressure.
  • the lid of the separable flask was opened and a roller was rolled on the porous membrane as if pressed, so that the monomer solution was impregnated into the porous membrane to form a monomer solution-impregnated porous body.
  • the monomer solution-impregnated porous body was taken out of the flask, and unnecessary monomer solution adhering to the surface of the monomer solution-impregnated porous body was scraped off using a sharp blade. This was then suspended in a separable flask.
  • the lid of the separable flask was attached, the inside of the flask was depressurized with a vacuum pump, and then returned to normal pressure with nitrogen to perform nitrogen replacement in the flask.
  • the separable flask sealed with nitrogen was placed in a constant temperature bath of about 100 ° C., and heating was continued for about 10 hours to carry out the monomer polymerization reaction in the monomer solution-impregnated porous body. After the reaction, the whole flask was allowed to cool to room temperature, and then the lid was opened and the electrolyte membrane suspended in the flask was taken out. In this way, an electrolyte membrane was formed.
  • Electrolyte membrane of Example 1 and Example 2, and content of PEGDA in Example 1 and Example 2 (weight of hydrophilic unit-containing polyfunctional crosslinking monomer, hydrophilic unit-containing polyfunctional crosslinking monomer and sulfonic acid group
  • the ion exchange capacity before the hydrothermal test of the electrolyte membrane obtained by changing only the weight% of the total vinyl monomer content) was measured.
  • the electrolyte membrane was immersed in a 0.1N HCl aqueous solution for 2 hours, rinsed with ultrapure water, and then vacuum dried at 60 ° C. for 1 hour. Thereafter, the ion exchange capacity (IEC) of the electrolyte membrane was calculated from the result of mass measurement. Further, using the electrolyte membranes of Examples 1 and 2 and the electrolyte membranes obtained by changing only the PEGDA content in Examples 1 and 2, the mixture was stirred with hot water at 100 ° C. for 1 hour. The hot water test was conducted, and the ion exchange capacity after the hot water test was measured. The graph which plotted the ion exchange capacity before and after the obtained hot-water test with respect to content of PEGDA is shown in FIG. 5 and FIG.
  • Example 1 As shown in FIG. 4, the electrolyte membrane of Example 1 was found to exhibit proton conductivity exceeding that of Comparative Example 1 which is a standard electrolyte membrane Nafion. Although not shown, in Comparative Example 2, since the HLB value was smaller than 5.0 and the hydrophobicity was high, a good crosslinked structure was not formed, and the proton conductivity was a low value. As shown in FIGS. 5 and 6, the ion exchange capacity (IEC) before the hot water test was 4 or more in Example 1, and 3 or more in Example 2, showing a high value. .
  • IEC ion exchange capacity
  • the ion exchange capacity after the hot water test is higher in both Example 1 and Example 2 by increasing polyethylene diacrylate (PEGDA), which is a hydrophilic functional unit-containing polyfunctional crosslinking monomer. It was possible to suppress the decrease in ion exchange capacity after the hot water test.
  • PEGDA polyethylene diacrylate
  • an electrolyte obtained by polymerizing at least a sulfonic acid group-containing vinyl monomer and a hydrophilic unit-containing polyfunctional crosslinking monomer having an HLB value of 5.0 or more is a main chain skeleton of the electrolyte.
  • a porous body having the same skeleton structure as the structure it is possible to improve the cross-linked structure in the electrolyte, and to increase the affinity between the electrolyte and the porous body be able to. Therefore, it was possible to obtain an electrolyte membrane having high ion exchange capacity retention, excellent adhesion between the electrolyte and the porous body, and improved proton conductivity.
  • the hydrophilic unit-containing polyfunctional crosslinking monomer by increasing the content of the hydrophilic unit-containing polyfunctional crosslinking monomer, it becomes possible to form a crosslinked structure more effectively, and even after a hot water test or the like, the ion exchange group is more reliably formed. It was possible to keep the ion exchange capacity high.

Abstract

Disclosed is an electrolyte membrane wherein the ion exchange capacity is well maintained, adhesion between an electrolyte and a porous body is excellent, and proton conductivity is improved. The electrolyte membrane is characterized in that the electrolyte membrane is obtained by impregnating a porous body with an electrolyte which is obtained by polymerizing at least a sulfonic acid group-containing vinyl monomer and a hydrophilic unit-containing polyfunctional crosslinkable monomer having an HLB value of not less than 5.0.  The porous body has the same skeletal structure as the main skeletal structure of the electrolyte.

Description

電解質膜Electrolyte membrane
　本発明は、イオン交換容量の保持性が高く、さらに電解質と多孔質体との密着性に優れ、プロトン伝導率が向上した電解質膜に関する。 The present invention relates to an electrolyte membrane having high ion exchange capacity retention, excellent adhesion between an electrolyte and a porous body, and improved proton conductivity.
　固体高分子電解質型燃料電池（以下、単に燃料電池と称する場合がある。）の最小発電単位である単位セルは、一般に固体電解質膜の両側に触媒電極層（アノード側触媒電極層およびカソード側触媒電極層）が接合されている膜電極複合体（ＭＥＡ：Ｍｅｍｂｒａｎｅ　Ｅｌｅｃｔｒｏｄｅ　Ａｓｓｅｍｂｌｙ）を有し、この膜電極複合体の両側にはガス拡散層が配されている。さらに、その外側にはガス流路を備えたセパレータが配されており、ガス拡散層を介して膜電極複合体の触媒電極層へと供給される燃料ガスおよび酸化剤ガスを通流させるとともに、発電により得られた電流を外部に伝える働きをしている。 A unit cell, which is a minimum power generation unit of a solid polymer electrolyte fuel cell (hereinafter sometimes referred to simply as a fuel cell), generally has a catalyst electrode layer (an anode side catalyst electrode layer and a cathode side catalyst) on both sides of a solid electrolyte membrane. It has a membrane electrode assembly (MEA: Electrode Assembly) to which an electrode layer is bonded, and gas diffusion layers are arranged on both sides of this membrane electrode assembly. Furthermore, a separator having a gas flow path is arranged outside thereof, and the fuel gas and the oxidant gas supplied to the catalyst electrode layer of the membrane electrode composite are passed through the gas diffusion layer, It works to transmit the current obtained by power generation to the outside.
　このような燃料電池では、アノード側触媒電極層から電解質膜、電解質膜からカソード側触媒電極層へのプロトンの移動に際して水が必要となる。したがって、一般的には燃料ガスを加湿して、燃料電池セル内に水を供給する方法が多く採用されている。しかしながら、例えば、自動車搭載用途などに燃料電池を使用する場合には、燃料ガスを加湿する装置は、重量物であり、燃費の低下、車載スペースの低下、コストの上昇などを招く。 In such a fuel cell, water is required for proton transfer from the anode side catalyst electrode layer to the electrolyte membrane and from the electrolyte membrane to the cathode side catalyst electrode layer. Therefore, generally, a method of humidifying the fuel gas and supplying water into the fuel cell is widely used. However, for example, when a fuel cell is used for a vehicle-mounted application or the like, a device that humidifies the fuel gas is a heavy object, which causes a reduction in fuel consumption, a reduction in vehicle space, an increase in cost, and the like.
　また、燃料電池セルの温度としては、反応効率の観点から４０～８０℃程度が望ましいため、通常はセルに冷却水を導入して、電池反応に伴う温度上昇を抑制している。しかしながら、冷却するには冷却ファン・ラジエータなどの重量物である装置が必要となり、これも、燃費低下、車載スペースの低下、コストの上昇を招く。 Also, since the temperature of the fuel battery cell is preferably about 40 to 80 ° C. from the viewpoint of reaction efficiency, usually, cooling water is introduced into the cell to suppress the temperature rise caused by the battery reaction. However, cooling requires a heavy device such as a cooling fan and a radiator, which also causes a reduction in fuel consumption, a reduction in in-vehicle space, and an increase in cost.
　そこで、上述したような「加湿」や「冷却」を行う必要がない状態、すなわち、できるだけ高温、低加湿の状態で燃料ガスを供給することが望ましい。特に自動車用の場合、室温付近から高温（８０～１００℃）域の幅広い温度領域において高い発電特性を示す必要がある。
　このような問題に対し、例えば、特許文献１には、スルホン酸基含有ビニルモノマーと架橋剤とを多孔質体に含浸させて、重合した電解質膜が開示されている。これは、高純度に精製した高濃度のビニルスルホン酸溶液を使用することにより、プロトン輸送能を有する上記スルホン酸基を高密度で配列させたプロトン伝導性ポリマーを上記電解質膜中に形成することが可能となり、プロトン伝導性が向上し、高温、低加湿の状態で高い発電特性が得られるものである。また、架橋剤を用いることにより、電解質膜中のプロトン伝導性ポリマーの溶解性等を抑制し、耐熱性を向上させることができるものである。 Therefore, it is desirable to supply the fuel gas in a state where it is not necessary to perform “humidification” and “cooling” as described above, that is, in a state where the temperature is as high as possible and the humidity is low. Particularly for automobiles, it is necessary to exhibit high power generation characteristics in a wide temperature range from near room temperature to high temperature (80 to 100 ° C.).
For example, Patent Document 1 discloses an electrolyte membrane obtained by impregnating a porous material with a sulfonic acid group-containing vinyl monomer and a cross-linking agent. This is because, by using a highly concentrated vinyl sulfonic acid solution purified to a high purity, a proton conductive polymer in which the sulfonic acid groups having proton transport ability are arranged at high density is formed in the electrolyte membrane. Proton conductivity is improved, and high power generation characteristics can be obtained at high temperature and low humidification. Moreover, by using a crosslinking agent, the solubility of the proton conductive polymer in the electrolyte membrane can be suppressed, and the heat resistance can be improved.
　しかしながら、この方法では、スルホン酸基含有ビニルモノマーと架橋剤との相溶性が低く充分な重合が進まないため、電解質膜中に架橋構造が充分に形成されず、これにより、プロトン伝導性ポリマーの溶解性を抑制することが困難になり、イオン交換容量が低下しやすいという問題があった。また、プロトン伝導性ポリマー等からなる電解質と多孔質体との界面等において剥離等して、ガスバリア性が低下し、電池特性が低下してしまうという問題もあった。 However, in this method, since the compatibility between the sulfonic acid group-containing vinyl monomer and the crosslinking agent is low and sufficient polymerization does not proceed, a sufficient crosslinked structure is not formed in the electrolyte membrane. There is a problem that it becomes difficult to suppress the solubility, and the ion exchange capacity tends to decrease. In addition, there is a problem that gas barrier properties are deteriorated and battery characteristics are deteriorated due to peeling at an interface between an electrolyte made of a proton conductive polymer or the like and a porous body.
特開２００６－２１６５３１号公報JP 2006-216531 A 特開２００８－７１７０６号公報JP 2008-71706 A 特開２００６－１２０６２０号公報JP 2006-120620 A
　本発明は、上記問題点に鑑みてなされたものであり、イオン交換容量の保持性が高く、さらに電解質と多孔質体との密着性に優れ、電池特性が向上した電解質膜を提供することを主目的とするものである。 The present invention has been made in view of the above problems, and provides an electrolyte membrane having high ion exchange capacity retention, excellent adhesion between an electrolyte and a porous body, and improved battery characteristics. This is the main purpose.
　上記目的を達成するために、本発明においては、少なくともスルホン酸基含有ビニルモノマーとＨＬＢ値が５．０以上である親水性ユニット含有多官能架橋モノマーとが重合してなる電解質が、上記電解質の主鎖骨格構造と同一の骨格構造を有する多孔質体に含浸されてなることを特徴とする電解質膜を提供する。 In order to achieve the above object, in the present invention, an electrolyte obtained by polymerizing at least a sulfonic acid group-containing vinyl monomer and a hydrophilic unit-containing polyfunctional crosslinking monomer having an HLB value of 5.0 or more is the above electrolyte. Provided is an electrolyte membrane characterized by being impregnated in a porous body having the same skeleton structure as a main chain skeleton structure.
　本発明によれば、上記親水性ユニット含有多官能架橋モノマーのＨＬＢ値を５．０以上とすることにより、電解質の合成が良好となり、上記電解質中の架橋構造を安定なものとすることが可能となる。これにより、イオン交換容量の保持性を高くすることができる。また、上記多孔質体の骨格構造を上記電解質の主鎖骨格構造と同一のものとすることにより、上記電解質と上記多孔質体との親和性を高めることが可能となり、電解質と多孔質体との密着性を向上させることができる。このため、ガスバリア性が低下することなく、良好な電池特性を有する電解質膜を得ることができる。 According to the present invention, by setting the HLB value of the hydrophilic unit-containing polyfunctional crosslinking monomer to 5.0 or more, the synthesis of the electrolyte is improved and the crosslinked structure in the electrolyte can be stabilized. It becomes. Thereby, the retainability of the ion exchange capacity can be increased. Further, by making the skeleton structure of the porous body the same as the main chain skeleton structure of the electrolyte, it becomes possible to increase the affinity between the electrolyte and the porous body, It is possible to improve the adhesion. For this reason, the electrolyte membrane which has a favorable battery characteristic can be obtained, without gas barrier property falling.
　上記発明においては、上記スルホン酸基含有ビニルモノマーがビニルスルホン酸であり、上記親水性ユニット含有多官能架橋モノマーがポリエチレングリコールジアクリレートであることが好ましい。効果的に上記電解質中の架橋構造を安定で良好なものとすることができるからである。 In the above invention, the sulfonic acid group-containing vinyl monomer is preferably vinyl sulfonic acid, and the hydrophilic unit-containing polyfunctional crosslinking monomer is preferably polyethylene glycol diacrylate. This is because the crosslinked structure in the electrolyte can be effectively made stable and good.
　上記発明においては、上記電解質が、上記スルホン酸基含有ビニルモノマーおよび上記ＨＬＢ値が５．０以上である親水性ユニット含有多官能架橋モノマーのみが重合してなるものであることが好ましい。上記電解質中のプロトン導電性をより良好なものとすることが可能となるからである。 In the above invention, the electrolyte is preferably obtained by polymerizing only the sulfonic acid group-containing vinyl monomer and the hydrophilic unit-containing polyfunctional crosslinking monomer having an HLB value of 5.0 or more. This is because the proton conductivity in the electrolyte can be made better.
　上記発明においては、上記多孔質体がビニル系骨格構造を有することが好ましい。効果的に、上記電解質と上記多孔質体との親和性を高め、より高い電池特性を維持することができるからである。 In the above invention, the porous body preferably has a vinyl skeleton structure. This is because the affinity between the electrolyte and the porous body can be effectively increased and higher battery characteristics can be maintained.
　上記発明においては、上記電解質膜のイオン交換容量が３．０ｍｅｑ／ｇ以上であることが好ましい。プロトン伝導率に優れた電解質膜とすることができるからである。 In the above invention, the ion exchange capacity of the electrolyte membrane is preferably 3.0 meq / g or more. It is because it can be set as the electrolyte membrane excellent in proton conductivity.
　また、本発明においては、少なくともスルホン酸基含有ビニルモノマーとＨＬＢ値が５．０以上である親水性ユニット含有多官能架橋モノマーとを含むモノマー溶液中に、上記モノマー溶液を重合してなる電解質の主鎖骨格構造と同一の骨格構造を有する多孔質体を浸漬させ、重合反応を抑制した状態で、上記多孔質体に対する機械的な圧力の付加および開放を行うことにより、上記多孔質体中に上記モノマー溶液を含浸させてモノマー溶液含浸多孔質体を得るモノマー溶液含浸工程と、上記モノマー溶液を重合して電解質膜を得る重合工程とを有することを特徴とする電解質膜の製造方法を提供する。 Further, in the present invention, an electrolyte obtained by polymerizing the monomer solution in a monomer solution containing at least a sulfonic acid group-containing vinyl monomer and a hydrophilic unit-containing polyfunctional crosslinking monomer having an HLB value of 5.0 or more. By immersing a porous body having the same skeleton structure as the main chain skeleton structure and applying and releasing a mechanical pressure to the porous body in a state in which a polymerization reaction is suppressed, Provided is a method for producing an electrolyte membrane, comprising: a monomer solution impregnation step for impregnating the monomer solution to obtain a monomer solution-impregnated porous body; and a polymerization step for polymerizing the monomer solution to obtain an electrolyte membrane. .
　本発明によれば、上述したような機械的な圧力を用いることにより、上記モノマー溶液を上記多孔質体内に効果的に含浸させることが可能となり、このような上記モノマー溶液が多孔質体内に効果的に含浸された状態で、上記モノマー溶液を重合することができる。さらに、上記スルホン酸基含有ビニルモノマーと上記親水性ユニット含有多官能架橋モノマーとがいずれも親水性であることにより、上記モノマー溶液中の上記スルホン酸基含有ビニルモノマーと上記親水性ユニット含有多官能架橋モノマーとを均一に分散することが可能となる。このため、イオン交換容量の保持性が高く、さらに電解質と多孔質体との密着性に優れ、プロトン伝導率を向上させた電解質膜を得ることができる。 According to the present invention, by using the mechanical pressure as described above, the monomer solution can be effectively impregnated in the porous body, and the monomer solution is effective in the porous body. The monomer solution can be polymerized in a state of being impregnated. Furthermore, since both the sulfonic acid group-containing vinyl monomer and the hydrophilic unit-containing polyfunctional crosslinking monomer are hydrophilic, the sulfonic acid group-containing vinyl monomer and the hydrophilic unit-containing polyfunctional monomer in the monomer solution are used. It becomes possible to uniformly disperse the crosslinking monomer. For this reason, it is possible to obtain an electrolyte membrane having high ion exchange capacity retention, excellent adhesion between the electrolyte and the porous body, and improved proton conductivity.
　本発明においては、イオン交換容量の保持性が高く、さらに電解質と多孔質体との密着性に優れ、プロトン伝導率が向上した電解質膜を得ることができるという効果を奏する。 In the present invention, it is possible to obtain an electrolyte membrane having high ion exchange capacity retention, excellent adhesion between the electrolyte and the porous body, and improved proton conductivity.
本発明の電解質膜の製造方法の一例を示す電解質膜形成フロー図である。It is an electrolyte membrane formation flowchart which shows an example of the manufacturing method of the electrolyte membrane of this invention. 機械的な圧力の付加および開放を行う方法の一例を説明する概略断面図である。It is a schematic sectional drawing explaining an example of the method of performing addition and releasing of mechanical pressure. 機械的な圧力の付加および開放を行う方法のその他の例を説明する概略断面図である。It is a schematic sectional drawing explaining the other example of the method of adding and releasing a mechanical pressure. 実施例１および比較例１で得られた電解質膜のプロトン伝導率を表すグラフである。3 is a graph showing proton conductivity of electrolyte membranes obtained in Example 1 and Comparative Example 1. FIG. 実施例１で得られた電解質膜のＰＥＧＤＡの含有量のみを変化させて形成された電解質膜の熱水試験前後のイオン交換容量を、ＰＥＧＤＡの含有量に対してプロットしたグラフである。2 is a graph in which the ion exchange capacity before and after the hydrothermal test of an electrolyte membrane formed by changing only the PEGDA content of the electrolyte membrane obtained in Example 1 is plotted against the PEGDA content. 実施例２で得られた電解質膜のＰＥＧＤＡの含有量のみを変化させて形成された電解質膜の熱水試験前後のイオン交換容量を、ＰＥＧＤＡの含有量に対してプロットしたグラフである。6 is a graph in which the ion exchange capacity before and after the hydrothermal test of an electrolyte membrane formed by changing only the PEGDA content of the electrolyte membrane obtained in Example 2 is plotted against the PEGDA content.
　本発明の電解質膜、および電解質膜の製造方法について、以下詳細に説明する。 The electrolyte membrane of the present invention and the method for producing the electrolyte membrane will be described in detail below.
Ａ．電解質膜
　まず、本発明の電解質膜について、以下詳細に説明する。
　本発明の電解質膜は、少なくともスルホン酸基含有ビニルモノマーとＨＬＢ値が５．０以上である親水性ユニット含有多官能架橋モノマーとが重合してなる電解質が、上記電解質の主鎖骨格構造と同一の骨格構造を有する多孔質体に含浸されてなることを特徴とするものである。 A. Electrolyte membrane First, the electrolyte membrane of the present invention will be described in detail below.
In the electrolyte membrane of the present invention, an electrolyte obtained by polymerizing at least a sulfonic acid group-containing vinyl monomer and a hydrophilic unit-containing polyfunctional crosslinking monomer having an HLB value of 5.0 or more is the same as the main chain skeleton structure of the electrolyte. It is characterized by being impregnated in a porous body having the skeleton structure.
　本発明によれば、上記親水性ユニット含有多官能架橋モノマーのＨＬＢ値を５．０以上とすることにより、例えば、水を溶媒として用いた場合に、上記親水性ユニット含有多官能架橋モノマーを均一に上記溶媒中に溶解させることができる。これにより、同様に水に対する溶解性が高い上記スルホン酸基含有ビニルモノマーとの反応性を良好なものとすることができる。このため、これらが重合してなる上記電解質中の架橋構造が上記電解質中に均一に形成されて、安定で良好なものとなる。これにより、例えば、上記電解質を熱水試験等行った後においても、イオン交換基の減少を抑制することが可能となり、イオン交換容量（乾燥イオン交換膜の重量１ｇ当たりのイオン交換基量（ｍｅｑ／ｇ））の保持性を高くすることができる。
　また、上記電解質の主鎖骨格構造と、上記多孔質体の骨格構造とが同一のものであるため、上記電解質と上記多孔質体との親和性を高めることができる。このため、上記電解質と上記多孔質体との密着性を優れたものとすることが可能となり、上記電解質と上記多孔質体との間の剥離等を抑制することができる。従って、ガスバリア性が低下することなく、さらには、プロトン伝導率が向上した電解質膜を得ることができるのである。
　このような本発明の電解質膜においては、少なくとも、上記電解質、および上記多孔質体を有するものであれば特に限定されるものではない。
　以下、本発明の電解質膜について、構成ごとに詳細に説明する。 According to the present invention, by setting the HLB value of the hydrophilic unit-containing polyfunctional crosslinking monomer to 5.0 or more, for example, when water is used as a solvent, the hydrophilic unit-containing polyfunctional crosslinking monomer is uniformly distributed. Can be dissolved in the above solvent. Thereby, the reactivity with the said sulfonic acid group containing vinyl monomer with high solubility with respect to water similarly can be made favorable. For this reason, the crosslinked structure in the electrolyte formed by polymerizing these is uniformly formed in the electrolyte, and becomes stable and good. Accordingly, for example, even after the electrolyte is subjected to a hydrothermal test or the like, it is possible to suppress a decrease in ion exchange groups, and the ion exchange capacity (the amount of ion exchange groups per 1 g of dry ion exchange membrane (meq / G)) can be improved.
In addition, since the main chain skeleton structure of the electrolyte and the skeleton structure of the porous body are the same, the affinity between the electrolyte and the porous body can be increased. For this reason, it becomes possible to make the adhesiveness of the said electrolyte and the said porous body excellent, and peeling etc. between the said electrolyte and the said porous body can be suppressed. Therefore, an electrolyte membrane with improved proton conductivity can be obtained without deteriorating gas barrier properties.
The electrolyte membrane of the present invention is not particularly limited as long as it has at least the electrolyte and the porous body.
Hereinafter, the electrolyte membrane of the present invention will be described in detail for each configuration.
１．電解質
　まず、本発明に用いられる電解質について説明する。本発明における電解質は、少なくともスルホン酸基含有ビニルモノマーとＨＬＢ値が５．０以上である親水性ユニット含有多官能架橋モノマーとが重合してなるものである。
　本発明においては、上述したように、上記スルホン酸基含有ビニルモノマーとＨＬＢ値が５．０以上である上記親水性ユニット含有多官能架橋モノマーとのいずれもが親水性であることにより、これらが重合してなる上記電解質中の架橋構造が上記電解質中に均一に形成されて安定で良好なものとなり、イオン交換基の減少を抑制することが可能となり、イオン交換容量の保持性を高くすることができる。 1. Electrolyte First, the electrolyte used in the present invention will be described. The electrolyte in the present invention is obtained by polymerizing at least a sulfonic acid group-containing vinyl monomer and a hydrophilic unit-containing polyfunctional crosslinking monomer having an HLB value of 5.0 or more.
In the present invention, as described above, both of the sulfonic acid group-containing vinyl monomer and the hydrophilic unit-containing polyfunctional crosslinking monomer having an HLB value of 5.0 or more are hydrophilic. The cross-linked structure in the electrolyte obtained by polymerization is uniformly formed in the electrolyte and becomes stable and good, and it is possible to suppress the reduction of ion exchange groups and increase the retention of ion exchange capacity. Can do.
　このような電解質においては、上述したように、少なくとも、上記スルホン酸基含有ビニルモノマーおよび上記親水性ユニット含有多官能架橋モノマーが重合してなるものであれば特に限定されるものではなく、さらにその他のモノマーを有した状態で重合してなるものであっても良い。
　以下、上記親水性ユニット含有多官能架橋モノマー、上記スルホン酸基含有ビニルモノマー、その他のモノマー、および上記モノマーを重合して得られる電解質（電解質ポリマー）について、それぞれ、詳細に説明する。 Such an electrolyte is not particularly limited as long as it is formed by polymerizing at least the sulfonic acid group-containing vinyl monomer and the hydrophilic unit-containing polyfunctional crosslinking monomer as described above. It may be formed by polymerization in a state having the monomer.
Hereinafter, the hydrophilic unit-containing polyfunctional crosslinking monomer, the sulfonic acid group-containing vinyl monomer, other monomers, and the electrolyte (electrolyte polymer) obtained by polymerizing the monomer will be described in detail.
（１）親水性ユニット含有多官能架橋モノマー
　まず、本発明における親水性ユニット含有多官能架橋モノマーについて説明する。本発明における親水性ユニット含有多官能架橋モノマーは、ＨＬＢ値が５．０以上であり、少なくとも親水性ユニットおよびビニル基等の官能基を有する多官能モノマーであるものである。本発明においては、このような親水性に優れた親水性ユニット含有多官能架橋モノマーを用いることにより、例えば、水を溶媒として用いた場合に、上記親水性ユニット含有多官能架橋モノマーを均一に上記溶媒中に溶解させることが可能となり、同様に水に対する溶解性が高い上記スルホン酸基含有ビニルモノマーとの反応性を良好なものとすることができる。このため、上記架橋構造が上記電解質中に均一に形成され、安定で良好なものとなるのである。 (1) Hydrophilic unit-containing polyfunctional crosslinking monomer First, the hydrophilic unit-containing polyfunctional crosslinking monomer in the present invention will be described. The hydrophilic unit-containing polyfunctional crosslinking monomer in the present invention is a polyfunctional monomer having an HLB value of 5.0 or more and having at least a hydrophilic unit and a functional group such as a vinyl group. In the present invention, by using such a hydrophilic unit-containing polyfunctional crosslinking monomer excellent in hydrophilicity, for example, when water is used as a solvent, the hydrophilic unit-containing polyfunctional crosslinking monomer is uniformly mixed with the above-mentioned hydrophilic unit-containing polyfunctional crosslinking monomer. It becomes possible to dissolve in a solvent, and the reactivity with the sulfonic acid group-containing vinyl monomer having high solubility in water can be improved. Therefore, the cross-linked structure is uniformly formed in the electrolyte, and becomes stable and good.
　ここで、上記ＨＬＢ（Ｈｙｄｒｏｐｈｉｌｅ－Ｌｉｐｏｐｈｉｌｅ　Ｂａｌａｎｃｅ）値とは、通常、０～２０までの値を取り、０に近いほど親油性が高く、２０に近いほど親水性が高いものである。この数値は、例えば、グリフィン法（ＨＬＢ値＝２０×親水部の式量の総和／分子量）により得ることができる。具体的には、例えば、ポリエチレングリコールジアクリレートはＨＬＢ値（グリフィン法）が６．１６であり、メチレンビスアクリルアミドでは３．９６である。 Here, the HLB (Hydrophile-Lipophile Balance) value usually takes a value from 0 to 20, and the closer to 0, the higher the lipophilicity, and the closer to 20, the higher the hydrophilicity. This numerical value can be obtained, for example, by the Griffin method (HLB value = 20 × total formula weight of hydrophilic part / molecular weight). Specifically, for example, polyethylene glycol diacrylate has an HLB value (Griffin method) of 6.16, and methylene bisacrylamide has 3.96.
　本発明における、上記親水性ユニット含有多官能架橋モノマーは、ＨＬＢ値が５．０以上である。上記ＨＬＢ値は、中でも、５．０～１５．０の範囲内、特に、５．０～１０．０の範囲内であることが好ましい。本発明においては、上記親水性ユニット含有多官能架橋モノマーが、上記範囲内のＨＬＢ値で表される親水性を有することにより、水等に対する溶解性を高いものとすることが可能となり、これにより、上述したように、均一な架橋構造が形成され、架橋構造を良好なものとすることができるのである。 In the present invention, the hydrophilic unit-containing polyfunctional crosslinking monomer has an HLB value of 5.0 or more. The HLB value is preferably in the range of 5.0 to 15.0, particularly in the range of 5.0 to 10.0. In the present invention, the hydrophilic unit-containing polyfunctional crosslinking monomer has a hydrophilicity represented by an HLB value within the above range, so that the solubility in water or the like can be increased. As described above, a uniform cross-linked structure is formed, and the cross-linked structure can be improved.
　上記親水性ユニット含有多官能架橋モノマーとしては、ＨＬＢ値が５．０以上であり、少なくとも親水性ユニットおよびビニル基等の官能基を有する多官能モノマーであれば特に限定されるものではない。
　上記親水性ユニット含有多官能架橋モノマー中の上記親水性ユニットとしては、上記ＨＬＢ値を５．０以上とすることができるようなものであれば、特に限定されるものではないが、例えば、下記式（１）で表されるようなポリエーテル系ユニット、スルホン化化合物等を挙げることができる。中でも、下記式（１）で表されるポリエーテル系ユニットであることが好ましい。上記電解質の機械強度を良好なものとすることができるからである。 The hydrophilic unit-containing polyfunctional crosslinking monomer is not particularly limited as long as it has a HLB value of 5.0 or more and has at least a hydrophilic unit and a functional group such as a vinyl group.
The hydrophilic unit in the hydrophilic unit-containing polyfunctional crosslinking monomer is not particularly limited as long as the HLB value can be 5.0 or more. Examples thereof include polyether units represented by the formula (1) and sulfonated compounds. Among these, a polyether unit represented by the following formula (1) is preferable. This is because the mechanical strength of the electrolyte can be improved.
Figure JPOXMLDOC01-appb-C000001
Figure JPOXMLDOC01-appb-C000001
　上記ポリエーテル系ユニット中の炭素数ｍは、通常、２～３の範囲内である。本発明においては、上記ポリエーテル系ユニットの中でも、上記炭素数ｍが２であるポリエチレングリコールが好ましい。また、上記ポリエーテル系ユニットにおける繰り返しユニットの数ｎとしては、２～４の範囲内であることが好ましく、中でも２であることが好ましい。上記炭素数および上記繰り返しユニットの数が、上記範囲内であれば、上記電解質膜中のポリエーテル系ユニットの化学的安定性を高めて分解が起こりにくいものとすることが可能となる。また、上記ポリエーテル系ユニットの余分な動きを抑制して架橋効果を高めることができる。さらに、少ない添加量で架橋点を多く形成することができるからである。 The carbon number m in the polyether unit is usually in the range of 2 to 3. In the present invention, among the polyether units, polyethylene glycol having 2 carbon atoms is preferable. Further, the number n of repeating units in the polyether-based unit is preferably in the range of 2 to 4, more preferably 2. When the number of carbon atoms and the number of repeating units are within the above ranges, it becomes possible to increase the chemical stability of the polyether unit in the electrolyte membrane and to prevent decomposition. Moreover, the excessive movement of the said polyether-type unit can be suppressed and the crosslinking effect can be heightened. Furthermore, it is because many crosslinking points can be formed with a small addition amount.
　上記親水性ユニット含有多官能架橋モノマー中の官能基としては、上述したような安定で良好な架橋構造を重合により形成することが可能であり、所望の上記電解質を得ることができるものであれば良く、特に限定されるものではないが、中でも、共役系ビニル基が好ましい。反応性が高く、温和な反応条件下で上記電解質を得ることができるからである。 As the functional group in the hydrophilic unit-containing polyfunctional crosslinking monomer, it is possible to form a stable and good crosslinked structure as described above by polymerization and obtain the desired electrolyte. Although not particularly limited, a conjugated vinyl group is preferable. This is because the electrolyte can be obtained under high reaction conditions under mild reaction conditions.
　上記親水性ユニット含有多官能架橋モノマーとしては、より具体的には例えば、下記式（２）で表されるポリエチレングリコールジアクリレート、ポリプロピレングリコールジアクリレート、ジビニルベンゼンスルホン酸等を挙げることができる。中でも、下記式（２）で表されるポリエチレングリコールジアクリレートであることが好ましい。より効果的に上記電解質中の架橋構造を良好なものとすることができるからである。
　なお、式（２）中のｎについては上述したものと同様である。 More specific examples of the hydrophilic unit-containing polyfunctional crosslinking monomer include polyethylene glycol diacrylate, polypropylene glycol diacrylate, and divinylbenzenesulfonic acid represented by the following formula (2). Among these, polyethylene glycol diacrylate represented by the following formula (2) is preferable. This is because the crosslinked structure in the electrolyte can be made more effective.
Note that n in the formula (2) is the same as described above.
Figure JPOXMLDOC01-appb-C000002
Figure JPOXMLDOC01-appb-C000002
　また、本発明における、上記親水性ユニット含有多官能架橋モノマーの、後述するスルホン酸基含有ビニルモノマーに対する割合としては、所望の上記電解質を得ることができれば、特に限定されるものではないが、例えば、上記電解質がポリエチレングリコールジアクリレート（親水性ユニット含有多官能架橋モノマー）および後述するビニルスルホン酸（スルホン酸基含有ビニルモノマー）のみを重合させて得られたものである場合には、上記親水性ユニット含有多官能架橋モノマー重量の、上記親水性ユニット含有多官能架橋モノマーおよび上記スルホン酸基含有ビニルモノマーの合計重量に対する重量％（親水性ユニット含有多官能架橋モノマー重量／（親水性ユニット含有多官能架橋モノマー重量＋スルホン酸基含有ビニルモノマー重量）×１００）が、１５重量％以上、中でも２０重量％～８０重量％の範囲内、特に、２５重量％～７０重量％の範囲内であることが好ましい。上記範囲内であれば、架橋構造をより効果的に形成することが可能となり、熱水試験等を行った後においても、より確実にイオン交換基の減少を抑制し、イオン交換容量を高く保持することが可能となるからである。 In the present invention, the ratio of the hydrophilic unit-containing polyfunctional crosslinking monomer to the sulfonic acid group-containing vinyl monomer described later is not particularly limited as long as the desired electrolyte can be obtained. In the case where the electrolyte is obtained by polymerizing only polyethylene glycol diacrylate (hydrophilic unit-containing polyfunctional crosslinking monomer) and vinylsulfonic acid (sulfonic acid group-containing vinyl monomer) described later, the hydrophilicity described above. Weight% of unit-containing polyfunctional crosslinking monomer weight based on the total weight of the hydrophilic unit-containing polyfunctional crosslinking monomer and the sulfonic acid group-containing vinyl monomer (weight of hydrophilic unit-containing polyfunctional crosslinking monomer / (hydrophilic unit-containing polyfunctional Cross-linking monomer weight + sulfonic acid group-containing vinyl mono Is over weight) × 100), 15 wt% or more, the range among them of 20% to 80% by weight, particularly preferably in the range of 25 wt% to 70 wt%. Within the above range, a crosslinked structure can be formed more effectively, and even after a hot water test or the like, the reduction of ion exchange groups is more reliably suppressed and the ion exchange capacity is kept high. Because it becomes possible to do.
（２）スルホン酸基含有ビニルモノマー
　次に、本発明に用いられるスルホン酸基含有ビニルモノマーについて説明する。本発明おけるスルホン酸基含有ビニルモノマーは、スルホン酸基（－ＳＯ３Ｈ）を有するビニルモノマーであり、親水性のものである。本発明においては、このようなスルホン酸基含有ビニルモノマーを用いることにより、少なくともスルホン酸基含有ビニルモノマーおよび上記親水性ユニット含有多官能架橋モノマーが重合してなる上記電解質中の架橋構造を上記電解質中において均一に形成することが可能となり、安定で良好なものとすることができるのである。 (2) Sulfonic Acid Group-Containing Vinyl Monomer Next, the sulfonic acid group-containing vinyl monomer used in the present invention will be described. The sulfonic acid group-containing vinyl monomer in the present invention is a vinyl monomer having a sulfonic acid group (—SO 3 H) and is hydrophilic. In the present invention, by using such a sulfonic acid group-containing vinyl monomer, a crosslinked structure in the electrolyte obtained by polymerizing at least the sulfonic acid group-containing vinyl monomer and the hydrophilic unit-containing polyfunctional crosslinking monomer is used as the electrolyte. It can be formed uniformly in the inside, and can be made stable and satisfactory.
　本発明に用いられる上記スルホン酸基含有ビニルモノマーは、スルホン酸基を有するビニルモノマーであり、親水性のものであれば特に限定されるものではないが、分子量が小さい方が好ましい。スルホン酸基含有ビニルモノマー中のスルホン酸基の重量分率を高くすることが可能となり、上記電解質のイオン交換容量を向上させることができるからである。 The sulfonic acid group-containing vinyl monomer used in the present invention is a vinyl monomer having a sulfonic acid group and is not particularly limited as long as it is hydrophilic, but preferably has a smaller molecular weight. This is because the weight fraction of the sulfonic acid group in the sulfonic acid group-containing vinyl monomer can be increased, and the ion exchange capacity of the electrolyte can be improved.
　このようなスルホン酸基含有ビニルモノマーとしては、下記式（３）で表されるビニルスルホン酸、アクリルアミドｎ－ブチルスルホン酸、スチレンスルホン酸等を挙げることができる。中でも、ビニルスルホン酸であることが好ましい。効果的に上記電解質のイオン交換容量を向上させることができるからである。 Examples of such sulfonic acid group-containing vinyl monomers include vinyl sulfonic acid represented by the following formula (3), acrylamide n-butyl sulfonic acid, and styrene sulfonic acid. Among these, vinyl sulfonic acid is preferable. This is because the ion exchange capacity of the electrolyte can be effectively improved.
Figure JPOXMLDOC01-appb-C000003
Figure JPOXMLDOC01-appb-C000003
　なお、本発明における上記スルホン酸基含有ビニルモノマーは、１種類のみ用いても良く、複数種類用いても良い。 In addition, only one type of sulfonic acid group-containing vinyl monomer in the present invention may be used, or a plurality of types may be used.
（３）その他のモノマー
　本発明における上記電解質は、上記スルホン酸基含有ビニルモノマーおよび上記親水性ユニット含有多官能架橋モノマー以外に、さらにその他のモノマーを有した状態で重合してなるものであっても良い。
　このようなその他のモノマーとしては、イオン交換容量の保持性が高く、さらに上記電解質と上記多孔質体との密着性に優れた上記電解質膜を得ることができ、親水性をある程度以上有するものであれば特に限定されるものではない。
　このようなその他のモノマーの上記ＨＬＢ値としては、好ましくは、５以上、特に５～１５の範囲内のものが好ましい。具体的には、アクリルアミド、ポリエチレングリコールモノアクリレート、ポリプロピレングリコールモノアクリレート、モルホリノアクリレート、ジメチルアミノプロピルアクリルアミド、アクリル酸、メタクリル酸、リン酸エステル系アクリレート、ビニルスルホン酸エチル、ビニルエチルエーテル、ビニルメチルエーテル、酢酸ビニル、２－ヒドロキシエチルアクリレート、２－ヒドロキシエチルメタクリレート等を挙げることができる。 (3) Other monomers In addition to the sulfonic acid group-containing vinyl monomer and the hydrophilic unit-containing polyfunctional crosslinking monomer, the electrolyte in the present invention is polymerized in a state having other monomers. Also good.
As such other monomers, it is possible to obtain the electrolyte membrane having high ion exchange capacity retention and excellent adhesion between the electrolyte and the porous body, and having a certain degree of hydrophilicity. There is no particular limitation as long as it is present.
The HLB value of such other monomers is preferably 5 or more, particularly preferably in the range of 5-15. Specifically, acrylamide, polyethylene glycol monoacrylate, polypropylene glycol monoacrylate, morpholino acrylate, dimethylaminopropyl acrylamide, acrylic acid, methacrylic acid, phosphate ester acrylate, ethyl vinyl sulfonate, vinyl ethyl ether, vinyl methyl ether, Examples thereof include vinyl acetate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate and the like.
　また、本発明においては、疎水性を有するモノマーを用いることは好ましくない。具体的には、ＨＬＢ値が４以下のもの、特に０～３．５の範囲内のものは、本発明において好ましくない。具体的には、メチルメタクリレート、ネオペンチルアルコールジアクリレート、トリメチロールプロパントリアクリレート、ペンタエリスリトールテトラアクリレート、ジペンタエリスリトールヘキサアクリレート、スチレン、クロロメチルスチレン、ジビニルベンゼン等を挙げることができる。上記電解質中の架橋構造を安定で良好なものとすることが困難となり、イオン交換容量の保持性等が低下してしまうおそれがあるからである。 In the present invention, it is not preferable to use a monomer having hydrophobicity. Specifically, those having an HLB value of 4 or less, particularly those in the range of 0 to 3.5 are not preferred in the present invention. Specific examples include methyl methacrylate, neopentyl alcohol diacrylate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, styrene, chloromethylstyrene, divinylbenzene, and the like. This is because it is difficult to make the crosslinked structure in the electrolyte stable and good, and there is a risk that the retention of the ion exchange capacity and the like may be reduced.
（４）電解質ポリマー
　上記電解質ポリマーは、少なくともスルホン酸基含有ビニルモノマーとＨＬＢ値が５．０以上である親水性ユニット含有多官能架橋モノマーとが重合してなるものであれば特に限定されるものではなく、さらにその他のモノマーを有した状態で重合してなるものであっても良いが、本発明においては、上記電解質が、スルホン酸基含有ビニルモノマーおよびＨＬＢ値が５．０以上である親水性ユニット含有多官能架橋モノマーのみが重合してなるものであることが好ましい。例えば、上述したような疎水性モノマー等を用いないことにより、より確実に、上記電解質中の架橋構造を良好なものとすることが可能となり、イオン交換容量の保持性が高く、さらに電解質と多孔質体との密着性に優れ、ガスバリア性が低下することなく、プロトン伝導率が向上した電解質膜を得ることができるからである。
　具体的には、ビニルスルホン酸およびポリエチレングリコールジアクリレートのみが重合してなる、下記式（４）で表される電解質ポリマー等を挙げることができる。 (4) Electrolyte polymer The electrolyte polymer is particularly limited as long as it is obtained by polymerizing at least a sulfonic acid group-containing vinyl monomer and a hydrophilic unit-containing polyfunctional crosslinking monomer having an HLB value of 5.0 or more. However, in the present invention, the electrolyte is a hydrophilic monomer having a sulfonic acid group-containing vinyl monomer and an HLB value of 5.0 or more. It is preferable that only the functional unit-containing polyfunctional crosslinking monomer is polymerized. For example, by not using the hydrophobic monomer as described above, it becomes possible to improve the cross-linking structure in the electrolyte more reliably, the ion exchange capacity is high, the electrolyte and the porous This is because it is possible to obtain an electrolyte membrane having excellent proton conductivity and excellent adhesion to the material without lowering the gas barrier property.
Specifically, an electrolyte polymer represented by the following formula (4) obtained by polymerizing only vinyl sulfonic acid and polyethylene glycol diacrylate can be given.
Figure JPOXMLDOC01-appb-C000004
Figure JPOXMLDOC01-appb-C000004
　上記式（４）中、ｋは親水性ユニットのユニット数を表し、これについては上記式（２）のｎと同様であるので、ここでの説明は省略する。また、ｉおよびｊは、それぞれ、例えば５００～１００００の範囲内、中でも１０００～１００００の範囲内であることが好ましい。ただし、ここで定める分子量に関しては高いほど好ましい。上限は、実施の状況を考えるに１００００となることが考えられるが、それ以上であっても良い。 In the above formula (4), k represents the number of units of the hydrophilic unit, which is the same as n in the above formula (2), so the description here is omitted. Further, i and j are each preferably in the range of, for example, 500 to 10,000, and more preferably in the range of 1,000 to 10,000. However, the molecular weight determined here is preferably as high as possible. The upper limit is considered to be 10,000 in consideration of the implementation status, but may be more than that.
２．多孔質体
　次に、本発明に用いられる多孔質体について説明する。本発明における多孔質体は、上記電解質の主鎖骨格構造と同一の骨格構造を有しており、上記電解質を含浸するものである。
　本発明においては、上記多孔質体の骨格構造と上記電解質の主鎖骨格構造とが同一のものであるため、上記電解質と上記多孔質体との親和性が高められ、上記電解質と上記多孔質体との密着性を優れたものとすることが可能となり、上記電解質と上記多孔質体との間の剥離等を抑制することができる。これにより、ガスバリア性が低下してしまう等の不具合を防止することができるのである。 2. Next, the porous body used in the present invention will be described. The porous body in the present invention has the same skeleton structure as the main chain skeleton structure of the electrolyte, and impregnates the electrolyte.
In the present invention, since the skeleton structure of the porous body and the main chain skeleton structure of the electrolyte are the same, the affinity between the electrolyte and the porous body is increased, and the electrolyte and the porous body are improved. It becomes possible to make the adhesiveness with a body excellent, and peeling between the electrolyte and the porous body can be suppressed. As a result, it is possible to prevent problems such as deterioration of gas barrier properties.
　本発明における上記多孔質体としては、上記電解質を含浸することが可能であり、上記多孔質体の骨格構造が上述した電解質の主鎖骨格構造と同一のものであれば良く、特に限定されるものではない。例えば、ビニル系骨格構造を有するもの、ＰＴＦＥ(ポリテトラフルオロエチレン)等のフッ素を含有するもの、ポリアクリロニトリル、ポリスチレン、スチレン・無水マレイン酸共重合体、アクリロニトリル・ブタジエン・スチレン共重合体、ポリビニルアルコール、ポリビニル酢酸、ポリビニル酢酸部分鹸化物、ポリ塩化ビニル等を挙げることができる。中でも、ビニル系骨格構造を有することが好ましい。効果的に、上記電解質と上記多孔質体との親和性を高めることができるからである。 The porous body in the present invention may be impregnated with the electrolyte, and the skeleton structure of the porous body may be the same as the main chain skeleton structure of the electrolyte described above, and is particularly limited. It is not a thing. For example, those having a vinyl skeleton structure, those containing fluorine such as PTFE (polytetrafluoroethylene), polyacrylonitrile, polystyrene, styrene / maleic anhydride copolymer, acrylonitrile / butadiene / styrene copolymer, polyvinyl alcohol And polyvinyl acetate, partially saponified polyvinyl acetate, and polyvinyl chloride. Among them, it is preferable to have a vinyl skeleton structure. This is because the affinity between the electrolyte and the porous body can be effectively increased.
　上記ビニル系骨格構造を有する材料としては、具体的には、ポリエチレン、ポリプロピレン、エチレン・酢酸ビニル共重合体、エチレン・メチルメタクリル酸共重合体等を挙げることができる。中でも、ポリエチレンであることが好ましい。 Specific examples of the material having a vinyl skeleton structure include polyethylene, polypropylene, an ethylene / vinyl acetate copolymer, and an ethylene / methyl methacrylic acid copolymer. Among these, polyethylene is preferable.
３．その他
　本発明においては、上記電解質膜のイオン交換容量が３．０ｍｅｑ／ｇ以上であることが好ましい。中でも、３．０～６．０の範囲内、特に、４．０～５．０の範囲内であることが好ましい。プロトン伝導率に優れた電解質膜とすることができるからである。 3. Others In the present invention, the ion exchange capacity of the electrolyte membrane is preferably 3.0 meq / g or more. In particular, it is preferably in the range of 3.0 to 6.0, particularly in the range of 4.0 to 5.0. It is because it can be set as the electrolyte membrane excellent in proton conductivity.
　本発明により得られる電解質膜の用途としては、特に限定されるものではないが、例えば、上記電解質膜と、上記電解質の両側に配設される電極（アノード及びカソード）とを備える膜電極複合体、上記膜電極複合体の両側にガス拡散層が配され、さらにその外側にガス流路を備えたセパレータが配された燃料電池等として、用いることができる。中でも、自動車用の膜電極複合体、燃料電池等に用いられる電解質膜として用いることが好ましい。
　上記膜電極複合体、上記燃料電池に用いられる上記電極、上記ガス拡散層、上記セパレータ等については、通常用いられるものと同様のものを用いることができ、ここでの説明は省略する。 The use of the electrolyte membrane obtained by the present invention is not particularly limited. For example, a membrane electrode assembly including the electrolyte membrane and electrodes (anode and cathode) disposed on both sides of the electrolyte. It can be used as a fuel cell or the like in which a gas diffusion layer is disposed on both sides of the membrane electrode assembly and a separator having a gas flow path is disposed on the outside thereof. Especially, it is preferable to use as an electrolyte membrane used for a membrane electrode assembly for automobiles, a fuel cell, and the like.
The membrane electrode assembly, the electrode used in the fuel cell, the gas diffusion layer, the separator, and the like can be the same as those normally used, and description thereof is omitted here.
　上記電解質膜の製造方法としては、イオン交換容量の保持性が高く、さらに電解質と多孔質体との密着性に優れ、プロトン伝導率が向上した電解質膜を得ることができる製造方法であれば特に限定されるものではない。例えば、後述する、「Ｂ．電解質膜の製造方法」に記載される方法等を挙げることができる。 As the method for producing the electrolyte membrane, any method can be used as long as it is a production method capable of obtaining an electrolyte membrane having high ion exchange capacity retention, excellent adhesion between the electrolyte and the porous body, and improved proton conductivity. It is not limited. For example, the method etc. which are described later in "B. Manufacturing method of electrolyte membrane" can be mentioned.
Ｂ．電解質膜の製造方法
　次に、本発明の電解質膜の製造方法について、以下詳細に説明する。
　本発明の電解質膜の製造方法は、少なくともスルホン酸基含有ビニルモノマーとＨＬＢ値が５．０以上である親水性ユニット含有多官能架橋モノマーとを含むモノマー溶液中に、上記モノマー溶液を重合してなる電解質の主鎖骨格構造と同一の骨格構造を有する多孔質体を浸漬させ、重合反応を抑制した状態で、上記多孔質体に対する機械的な圧力の付加および開放を行うことにより、上記多孔質体中に上記モノマー溶液を含浸させてモノマー溶液含浸多孔質体を得るモノマー溶液含浸工程と、上記モノマー溶液を重合して電解質膜を得る重合工程とを有することを特徴とするものである。 B. Next, the manufacturing method of the electrolyte membrane of this invention is demonstrated in detail below.
The method for producing an electrolyte membrane of the present invention comprises polymerizing the monomer solution in a monomer solution containing at least a sulfonic acid group-containing vinyl monomer and a hydrophilic unit-containing polyfunctional crosslinking monomer having an HLB value of 5.0 or more. By immersing a porous body having the same skeleton structure as the main chain skeleton structure of the electrolyte and suppressing the polymerization reaction, mechanical pressure is applied to and released from the porous body. It comprises a monomer solution impregnation step for impregnating the monomer solution into a body to obtain a monomer solution-impregnated porous body, and a polymerization step for polymerizing the monomer solution to obtain an electrolyte membrane.
　本発明によれば、上述したような機械的な圧力を用いることにより、上記モノマー溶液を上記多孔質体内に効果的に含浸させることが可能となり、このような上記モノマー溶液が多孔質体内に効果的に含浸された状態で、上記モノマー溶液を重合することができる。また、上記親水性ユニット含有多官能架橋モノマーのＨＬＢ値を５．０以上とすることにより、例えば、水を溶媒として用いた場合に、上記親水性ユニット含有多官能架橋モノマーを均一に上記溶媒中に溶解させることが可能となり、同様に水に対する溶解性が高い上記スルホン酸基含有ビニルモノマーとの反応性を良好なものとすることができる。
　このため、上記電解質と上記多孔質体との親和性が高く、上記電解質と上記多孔質体との密着性を優れたものとすることが可能となり、上記電解質と上記多孔質体との間の剥離等を抑制することができる。さらに、上記電解質中の架橋構造が安定で良好となり、熱水試験等を行った後においても、イオン交換基の減少を抑制することが可能となり、イオン交換容量の保持性を高くすることができる。従って、ガスバリア性の低下を防止することが可能となり、電池特性が向上した電解質膜を得ることができるのである。 According to the present invention, by using the mechanical pressure as described above, the monomer solution can be effectively impregnated in the porous body, and the monomer solution is effective in the porous body. The monomer solution can be polymerized in a state of being impregnated. Further, by setting the HLB value of the hydrophilic unit-containing polyfunctional crosslinking monomer to 5.0 or more, for example, when water is used as a solvent, the hydrophilic unit-containing polyfunctional crosslinking monomer is uniformly contained in the solvent. It is possible to dissolve the sulfonic acid group-containing vinyl monomer having a high solubility in water.
Therefore, the affinity between the electrolyte and the porous body is high, and the adhesion between the electrolyte and the porous body can be made excellent. Separation and the like can be suppressed. Furthermore, the crosslinked structure in the electrolyte is stable and good, and even after a hot water test or the like, it is possible to suppress a decrease in ion exchange groups, and it is possible to increase the retention of ion exchange capacity. . Accordingly, it is possible to prevent the gas barrier property from being lowered, and an electrolyte membrane having improved battery characteristics can be obtained.
　このような本発明の電解質膜の製造方法としては、具体的には、図１に例示するような、電解質膜形成フロー図に沿って、次のような工程を経ることにより、電解質膜を得ることができる。
　例えば、まず、容器中に、スルホン酸基含有ビニルモノマー、ＨＬＢ値が５．０以上である親水性ユニット含有多官能架橋モノマー、ラジカル重合開始剤、および溶媒を所定の量添加して、混合し、モノマー溶液を調製する。次に、氷冷したモノマー溶液に、上記モノマー溶液を重合してなる電解質の主鎖骨格構造と同一の骨格構造を有する多孔質体を浸す。
　次に、上記容器に蓋をし、アスピレーター等で、減圧し、多孔質体の細孔にモノマー溶液を誘導する脱気処理を行い、脱気を所定の時間行う。この後、アスピレーターを停止し、容器内に空気を送り込み、常圧に戻す脱気工程を行う。
　次に、上記容器の蓋を開けて、氷冷したモノマー溶液に、上記多孔質体を浸した状態のまま、機械的な圧力の付加および開放を行うことにより、モノマー溶液を多孔質体へ含浸させて、モノマー溶液含浸多孔質体を得るモノマー溶液含浸工程を行う。 As a method for producing the electrolyte membrane of the present invention, specifically, an electrolyte membrane is obtained by performing the following steps along the electrolyte membrane formation flowchart illustrated in FIG. be able to.
For example, first, a predetermined amount of a sulfonic acid group-containing vinyl monomer, a hydrophilic unit-containing polyfunctional crosslinking monomer having an HLB value of 5.0 or more, a radical polymerization initiator, and a solvent are added to a container and mixed. Prepare a monomer solution. Next, the porous body having the same skeleton structure as the main chain skeleton structure of the electrolyte obtained by polymerizing the monomer solution is immersed in the ice-cooled monomer solution.
Next, the container is covered, depressurized with an aspirator or the like, a deaeration process for inducing the monomer solution into the pores of the porous body is performed, and deaeration is performed for a predetermined time. Thereafter, the aspirator is stopped, air is sent into the container, and a deaeration process for returning to normal pressure is performed.
Next, the container is opened, and the porous body is impregnated with the monomer solution by applying and releasing mechanical pressure while the porous body is immersed in the ice-cooled monomer solution. Then, a monomer solution impregnation step for obtaining a monomer solution-impregnated porous body is performed.
　次に、上記モノマー溶液含浸工程で得られたモノマー溶液含浸多孔質体を上記容器から取り出し、モノマー溶液含浸多孔質体表面に付着したモノマー溶液を除去するモノマー溶液除去工程を行い、この後、容器内に吊るす。
　次に、容器に蓋を装着し、容器内を真空ポンプ等で減圧し、窒素で常圧に戻すことにより、容器内の窒素置換を行う。次に、上記容器ごと、所定の温度の恒温槽等に設置して、所定の時間加熱し、重合反応させる重合工程を行うことにより電解質膜を得ることができる。反応後は、容器ごと室温まで放冷等により冷却し、次に、容器を開けて得られた電解質膜を取り出す。 Next, the monomer solution impregnated porous body obtained in the monomer solution impregnation step is taken out of the container, and a monomer solution removal step for removing the monomer solution adhering to the surface of the monomer solution impregnated porous body is performed. Hang inside.
Next, a lid is attached to the container, the inside of the container is depressurized with a vacuum pump or the like, and returned to normal pressure with nitrogen, thereby replacing the nitrogen in the container. Next, the electrolyte membrane can be obtained by performing a polymerization process in which the container is placed in a constant temperature bath or the like at a predetermined temperature, heated for a predetermined time, and subjected to a polymerization reaction. After the reaction, the whole container is cooled to room temperature by cooling, etc., and then the electrolyte membrane obtained by opening the container is taken out.
　このような本発明の電解質膜の製造方法においては、少なくとも上記モノマー溶液含浸工程、および上記重合工程を有するものであれば特に限定されるものではなく、上述した脱気工程等の他の工程を有していても良い。
　以下、本発明の電解質膜の製造方法における各工程について、詳細に説明する。 The method for producing an electrolyte membrane of the present invention is not particularly limited as long as it has at least the monomer solution impregnation step and the polymerization step, and includes other steps such as the deaeration step described above. You may have.
Hereafter, each process in the manufacturing method of the electrolyte membrane of this invention is demonstrated in detail.
１．モノマー溶液含浸工程
　本発明におけるモノマー溶液含浸工程について説明する。本発明におけるモノマー溶液含浸工程とは、少なくともスルホン酸基含有ビニルモノマーとＨＬＢ値が５．０以上である親水性ユニット含有多官能架橋モノマーとを含むモノマー溶液中に、上記モノマー溶液を重合してなる電解質の主鎖骨格構造と同一の骨格構造を有する多孔質体を浸漬させ、重合反応を抑制した状態で、上記多孔質体に対する機械的な圧力の付加および開放を行うことにより、上記多孔質体中に上記モノマー溶液を含浸させてモノマー溶液含浸多孔質体を得る工程である。 1. Monomer solution impregnation step The monomer solution impregnation step in the present invention will be described. The monomer solution impregnation step in the present invention is a polymerization of the monomer solution in a monomer solution containing at least a sulfonic acid group-containing vinyl monomer and a hydrophilic unit-containing polyfunctional crosslinking monomer having an HLB value of 5.0 or more. By immersing a porous body having the same skeleton structure as the main chain skeleton structure of the electrolyte and suppressing the polymerization reaction, mechanical pressure is applied to and released from the porous body. In this step, the monomer solution is impregnated in the body to obtain a monomer solution-impregnated porous body.
　本工程に用いられる、上記モノマー溶液は、少なくともスルホン酸基含有ビニルモノマーとＨＬＢ値が５．０以上である親水性ユニット含有多官能架橋モノマーとを含むものである。上記モノマー溶液中に含まれる、上記スルホン酸基含有ビニルモノマー、上記親水性ユニット含有多官能架橋モノマーについては、上述した「Ａ．電解質膜　１．電解質」に記載したものと同様のものであるので、ここでの説明は省略する。
　また、上記モノマー溶液は、上記スルホン酸基含有ビニルモノマーおよび上記親水性ユニット含有多官能架橋モノマー以外に、さらにその他のモノマーを有していても良い。このようなその他のモノマーについては、上述した「Ａ．電解質膜　１．電解質」に記載したものと同様のものであるので、ここでの説明は省略する。 The monomer solution used in this step contains at least a sulfonic acid group-containing vinyl monomer and a hydrophilic unit-containing polyfunctional crosslinking monomer having an HLB value of 5.0 or more. The sulfonic acid group-containing vinyl monomer and the hydrophilic unit-containing polyfunctional crosslinking monomer contained in the monomer solution are the same as those described in “A. Electrolyte membrane 1. Electrolyte” described above. Explanation here is omitted.
The monomer solution may further contain other monomers in addition to the sulfonic acid group-containing vinyl monomer and the hydrophilic unit-containing polyfunctional crosslinking monomer. Such other monomers are the same as those described in the above-mentioned “A. Electrolyte membrane 1. Electrolyte”, and thus description thereof is omitted here.
　また、上記モノマー溶液は、所定の溶媒を用いて、上記溶媒中に、上記スルホン酸基含有ビニルモノマー、上記親水性ユニット含有多官能架橋モノマー、その他のモノマー等を添加して形成することができる。上記溶媒としては、上記スルホン酸基含有ビニルモノマー、上記親水性ユニット含有多官能架橋モノマー、その他のモノマー等を溶解することが可能であり、所望の上記モノマー溶液を得ることができるものであれば、特に限定されるものではない。例えば、水、メタノール、エタノール、イソプロピルアルコール（ＩＰＡ）、ジメチルホルムアミド（ＤＭＦ）、ジメチルアセトアミド、Ｎ－メチルピロリドン（ＮＭＰ）、ヘキサメチルホスホラミド（ＨＭＰＡ）、エチルセロソルブ、メチルセロソルブ、エチレングリコール、プロピレングリコール、炭酸エチレン、炭酸プロピレン、炭酸ジエチル、アセトニトリル、アセトン、テトラヒドロフラン（ＴＨＦ）、メチルエチルケトン（ＭＥＫ）、およびこれらの混合物等を挙げることができ、中でも、水、メタノール、ＤＭＦ、ＮＭＰ、ＨＭＰＡ、特に、水が好ましい。本発明においては、通常、スルホン酸基の密度の高いモノマー溶液を用いるため、上記溶媒としては極めて高い親水性を求められるからである。なお、本発明においては、上記モノマー溶液を、上記溶媒を用いずに、上記スルホン酸基含有ビニルモノマー、上記親水性ユニット含有多官能架橋モノマー、その他のモノマー等を混合することにより調製しても良い。 The monomer solution can be formed using a predetermined solvent by adding the sulfonic acid group-containing vinyl monomer, the hydrophilic unit-containing polyfunctional crosslinking monomer, other monomers, and the like to the solvent. . The solvent is not particularly limited as long as it can dissolve the sulfonic acid group-containing vinyl monomer, the hydrophilic unit-containing polyfunctional crosslinking monomer, other monomers, and the like, and can obtain the desired monomer solution. There is no particular limitation. For example, water, methanol, ethanol, isopropyl alcohol (IPA), dimethylformamide (DMF), dimethylacetamide, N-methylpyrrolidone (NMP), hexamethylphosphoramide (HMPA), ethyl cellosolve, methyl cellosolve, ethylene glycol, propylene glycol , Ethylene carbonate, propylene carbonate, diethyl carbonate, acetonitrile, acetone, tetrahydrofuran (THF), methyl ethyl ketone (MEK), and mixtures thereof. Among them, water, methanol, DMF, NMP, HMPA, especially water Is preferred. In the present invention, since a monomer solution having a high density of sulfonic acid groups is usually used, extremely high hydrophilicity is required as the solvent. In the present invention, the monomer solution may be prepared by mixing the sulfonic acid group-containing vinyl monomer, the hydrophilic unit-containing polyfunctional crosslinking monomer, other monomers, etc. without using the solvent. good.
　また、上記モノマー溶液中には、通常、後述する重合工程において重合を開始するために用いられる重合開始剤が、含有されている。上記重合開始剤としては、上記溶媒の種類等によって変化するものであり、溶媒の種類等に応じて、適宜選択することができる。例えば、アゾ化合物、有機過酸化物等を挙げることができる。 The monomer solution usually contains a polymerization initiator used for initiating polymerization in the polymerization step described later. The polymerization initiator varies depending on the type of the solvent and can be appropriately selected according to the type of the solvent. For example, an azo compound, an organic peroxide, etc. can be mentioned.
　本工程に用いられる上記多孔質体は、上記モノマー溶液を重合してなる電解質の主鎖骨格構造と同一の骨格構造を有し、上記モノマー溶液を含浸するものである。上記多孔質体の詳細については、上述した「Ａ．電解質膜　２．多孔質体」に記載したものと同様のものであるので、ここでの説明は省略する。 The porous body used in this step has the same skeleton structure as the main chain skeleton structure of the electrolyte obtained by polymerizing the monomer solution, and impregnates the monomer solution. The details of the porous body are the same as those described in “A. Electrolyte membrane 2. Porous body” described above, and thus the description thereof is omitted here.
　本工程において、上記多孔質体中に上記モノマー溶液を含浸させる方法としては、上記モノマー溶液中に、上記多孔質体を浸漬させ、重合反応を抑制した状態で、上記多孔質体に対する機械的な圧力の付加および開放を行うことにより含浸させる方法であれば、特に限定されるものではない。
　上記機械的な圧力の付加および開放を行う方法としては、例えば、図２に示されるように、冷却したモノマー溶液１中に多孔質体２を浸漬させ、多孔質体２をローラー３等により所定の圧力で挟持しながら、例えば図２中の矢印に示されるような所定の方向に移動させる方法等を挙げることができる。
　また、図３に示されるように、冷却したモノマー溶液１中に浸漬され、プレス用板４上に設置された多孔質体２に対して、プレス装置５等により所定の圧力の付加および開放を行う方法等を挙げることができる。
　なお、上記多孔質体内に上記モノマー溶液を効果的に含浸させて、所望の上記モノマー溶液含浸多孔質体を得ることができれば、上述した機械的な圧力の付加および開放は、一回行うのみであっても良く、複数回繰り返して行っても良い。 In this step, the porous body is impregnated with the monomer solution by immersing the porous body in the monomer solution and suppressing the polymerization reaction. The method is not particularly limited as long as it is a method of impregnation by applying and releasing pressure.
As a method for applying and releasing the mechanical pressure, for example, as shown in FIG. 2, the porous body 2 is immersed in a cooled monomer solution 1 and the porous body 2 is predetermined by a roller 3 or the like. For example, a method of moving in a predetermined direction as indicated by an arrow in FIG.
Further, as shown in FIG. 3, a predetermined pressure is applied to and released from the porous body 2 immersed in the cooled monomer solution 1 and placed on the pressing plate 4 by the pressing device 5 or the like. The method of performing etc. can be mentioned.
In addition, if the said monomer solution can be effectively impregnated in the porous body to obtain the desired monomer solution-impregnated porous body, the application and release of the mechanical pressure described above can be performed only once. It may be repeated several times.
　また、上記重合反応を抑制する方法としては、上記モノマー溶液を、モノマー溶液の入った容器ごと氷冷する方法等を挙げることができる。また、低温の不活性ガス(例えば低温の窒素ガスや低温のアルゴンガス)を直接、上記多孔質体に吹き付けて冷却する方法等を用いても良い。 In addition, as a method for suppressing the polymerization reaction, a method of cooling the monomer solution in a container containing the monomer solution with ice can be exemplified. Alternatively, a method of cooling by blowing low temperature inert gas (for example, low temperature nitrogen gas or low temperature argon gas) directly on the porous body may be used.
２．重合工程
　本発明における重合工程について説明する。本発明における重合工程とは、上記モノマー溶液含浸工程で得られた上記モノマー溶液含浸多孔質体を用いて、重合を行い、電解質膜を得る工程である。 2. Polymerization step The polymerization step in the present invention will be described. The polymerization step in the present invention is a step of obtaining an electrolyte membrane by performing polymerization using the monomer solution-impregnated porous material obtained in the monomer solution impregnation step.
　本工程において、上記モノマー溶液含浸多孔質体を用いて重合を行う際の、重合方法としては、プロトン伝導率が向上した所望の上記電解質膜を得ることができる方法であれば特に限定されるものではない。
　例えば、上記モノマー溶液含浸工程で得られた上記モノマー溶液含浸多孔質体表面に付着した余分なモノマー溶液を除去するモノマー溶液除去工程を行い、この後容器内に設置する。この後、容器に蓋を装着し、容器内を真空ポンプで減圧し、窒素で常圧に戻すことにより、容器内の窒素置換を行い、さらに、上記容器ごと、所定の温度の恒温槽に設置して、所定の時間加熱する方法等を挙げることができる。 In this step, the polymerization method for carrying out the polymerization using the monomer solution-impregnated porous body is not particularly limited as long as it can obtain the desired electrolyte membrane with improved proton conductivity. is not.
For example, a monomer solution removing step for removing an excess monomer solution adhering to the surface of the monomer solution impregnated porous body obtained in the monomer solution impregnating step is performed, and then placed in a container. After this, the container is fitted with a lid, the inside of the container is depressurized with a vacuum pump, and returned to normal pressure with nitrogen, so that the inside of the container is replaced with nitrogen, and further, the above containers are installed in a constant temperature bath at a predetermined temperature. And a method of heating for a predetermined time.
　上記重合の条件、例えば、ガス置換を行う際のガス雰囲気、重合する際の温度や時間等については、所望の上記電解質膜を得ることができる条件であれば、特に限定されるものではなく、予備実験を行うことにより、適宜設定することができる。 The conditions for the polymerization, for example, the gas atmosphere at the time of gas substitution, the temperature and time for the polymerization, etc. are not particularly limited as long as the desired electrolyte membrane can be obtained. It can be set as appropriate by conducting a preliminary experiment.
３．その他工程
　本発明の電解質膜の製造方法は、少なくとも上記モノマー溶液含浸工程および上記重合工程を有するものであれば特に限定されるものではないが、上記モノマー溶液含浸工程および上記重合工程の他に、上述したような脱気工程等を有していても良い。
　以下、脱気工程、およびその他工程の各工程について詳細に説明する。 3. Other Steps The method for producing an electrolyte membrane of the present invention is not particularly limited as long as it has at least the monomer solution impregnation step and the polymerization step. In addition to the monomer solution impregnation step and the polymerization step, You may have the deaeration process etc. which were mentioned above.
Hereinafter, each process of a deaeration process and another process is demonstrated in detail.
（１）脱気工程
　本発明における脱気工程について説明する。本発明における脱気工程とは、モノマー溶液中に浸漬させた多孔質体から、減圧することにより脱気を行い、多孔質体の細孔に上記モノマー溶液を誘導する工程である。
　本工程は、上記モノマー溶液含浸工程の前に行っても良く、上記モノマー溶液含浸工程の後に上記モノマー溶液含浸多孔質体を用いて行っても良い。通常は、上記モノマー溶液含浸工程の前に行う。 (1) Deaeration process The deaeration process in this invention is demonstrated. The degassing step in the present invention is a step of degassing the porous body immersed in the monomer solution by reducing the pressure to induce the monomer solution into the pores of the porous body.
This step may be performed before the monomer solution impregnation step, or may be performed using the monomer solution impregnated porous body after the monomer solution impregnation step. Usually, it is performed before the monomer solution impregnation step.
　本工程を経ることにより、多孔質体の細孔に上記モノマー溶液をより効果的に含浸させることができる。 By passing through this step, the monomer solution can be more effectively impregnated into the pores of the porous body.
　上記脱気する方法としては、モノマー溶液中に浸漬させた多孔質体から、減圧することにより脱気を行い、多孔質体の細孔に上記モノマー溶液を誘導することができる方法であれば特に限定されるものではない。
　例えば、本工程を、上記モノマー溶液含浸工程の前に行う場合には、容器中に、スルホン酸基含有ビニルモノマー、ＨＬＢ値が５．０以上である親水性ユニット含有多官能架橋モノマー、ラジカル重合開始剤、および溶媒を、所定の量添加して、混合してモノマー溶液を調製する。次に、氷冷したモノマー溶液に、上記多孔質体を浸す。その後、上記容器に蓋をし、アスピレーターで減圧し、多孔質体の細孔にモノマー溶液を誘導する方法等を挙げることができる。
　また、例えば、本工程を、上記モノマー溶液含浸工程の後に行う場合には、上記モノマー溶液含浸工程が終了した後、上記モノマー溶液含浸多孔質体がモノマー溶液中に浸漬されたままの状態で、上述したように、アスピレーターを用いて減圧する方法等を挙げることができる。 As the method for degassing, any method can be used as long as it can degas from a porous body immersed in a monomer solution by reducing the pressure to induce the monomer solution into the pores of the porous material. It is not limited.
For example, when this step is performed before the monomer solution impregnation step, a sulfonic acid group-containing vinyl monomer, a hydrophilic unit-containing polyfunctional crosslinking monomer having an HLB value of 5.0 or more, radical polymerization in a container. A predetermined amount of an initiator and a solvent are added and mixed to prepare a monomer solution. Next, the porous body is immersed in an ice-cooled monomer solution. Thereafter, a method of covering the vessel and reducing the pressure with an aspirator to induce the monomer solution into the pores of the porous body can be exemplified.
Further, for example, when this step is performed after the monomer solution impregnation step, after the monomer solution impregnation step is finished, the monomer solution impregnated porous body is immersed in the monomer solution, As described above, a method of reducing the pressure using an aspirator can be exemplified.
　上記脱気する際の条件、例えば、上記容器中を減圧する時間等については、所望の脱気ができる条件であれば、特に限定されるものではなく、予備実験を行うにより、適宜設定することができる。 The degassing conditions, such as the time during which the inside of the container is depressurized, are not particularly limited as long as the conditions allow desired degassing, and may be set as appropriate by conducting a preliminary experiment. Can do.
（２）その他工程
　本発明においては、その他工程として、上述したようなモノマー溶液除去工程を有していても良い。本発明における上記モノマー溶液除去工程とは、上記モノマー溶液含浸多孔質体表面の不必要な残存モノマー溶液を、ブレード等を用いて除去する工程であり、通常、上記モノマー溶液含侵工程の後、上記重合工程の前に行う。本工程を経ることにより、より良好な上記電解質膜を得ることができる。 (2) Other process In this invention, you may have a monomer solution removal process as mentioned above as another process. The monomer solution removal step in the present invention is a step of removing unnecessary residual monomer solution on the surface of the monomer solution-impregnated porous body using a blade or the like, and usually after the monomer solution impregnation step, It is carried out before the polymerization step. By passing through this step, a better electrolyte membrane can be obtained.
４．その他
　本発明により得られる電解質膜については、上述した「Ａ．電解質膜」に記載したものと同様のものであるので、ここでの説明は省略する。 4). Others The electrolyte membrane obtained by the present invention is the same as that described in the above-mentioned “A. Electrolyte membrane”, and thus the description thereof is omitted here.
　なお、本発明は、上記実施形態に限定されるものではない。上記実施形態は、例示であり、本発明の特許請求の範囲に記載された技術的思想と実質的に同一な構成を有し、同様な作用効果を奏するものは、いかなるものであっても本発明の技術的範囲に包含される。 Note that the present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has substantially the same configuration as the technical idea described in the claims of the present invention, and any device that exhibits the same function and effect is the present invention. It is included in the technical scope of the invention.
　以下に実施例を示して本発明をさらに具体的に説明する。 The present invention will be described more specifically with reference to the following examples.
　[実施例１]
（モノマー溶液含浸多孔質体形成）
　１００ｍＬのセパラブルフラスコに、ビニルスルホン酸（ＶＳＡ－Ｈ、旭化成ファインケム社製）０．８０ｇ、ポリエチレングリコールジアクリレート（ＰＥＧＤＡ）（親水性ユニット数ｎ＝２、アルドリッチ社製）（ＨＬＢ値＝６．１６）０．２０ｇ、および、水溶性ラジカル重合開始剤（Ｖ－５０１、和光純薬製）２０ｍｇを添加し、混合して、モノマー溶液を調製した。
　なお、ＰＥＧＤＡのＨＬＢ値は、グリフィン法（ＨＬＢ値＝２０×親水部の式量の総和／分子量）により導出した。
　次に、セパラブルフラスコごと氷冷したモノマー溶液に縦横５ｃｍ角のポリエチレン製の多孔質膜（ソルポア　１６ＰＯ５Ａ）を浸した。セパラブルフラスコの蓋を装着し、フラスコ内をアスピレータで減圧し、多孔質膜の細孔にモノマー溶液を誘導する脱気処理を行った。脱気処理は約３分間行い、アスピレータを停止し、フラスコ内に空気を送り込み常圧に戻した。
　次に、セパラブルフラスコの蓋を開けて、押し付けるようにして多孔質膜上でローラーを転がし、モノマー溶液を多孔質膜へ含浸させて、モノマー溶液含浸多孔質体を形成した。 [Example 1]
(Monomer solution impregnation porous body formation)
In a 100 mL separable flask, 0.80 g of vinyl sulfonic acid (VSA-H, manufactured by Asahi Kasei Finechem), polyethylene glycol diacrylate (PEGDA) (hydrophilic unit number n = 2, manufactured by Aldrich) (HLB value = 6. 16) 0.20 g and 20 mg of a water-soluble radical polymerization initiator (V-501, manufactured by Wako Pure Chemical Industries, Ltd.) were added and mixed to prepare a monomer solution.
The HLB value of PEGDA was derived by the Griffin method (HLB value = 20 × total formula weight of hydrophilic part / molecular weight).
Next, a 5 cm square polyethylene porous membrane (Solpore 16PO5A) was immersed in the monomer solution cooled with ice in the separable flask. A lid of a separable flask was attached, the inside of the flask was depressurized with an aspirator, and a deaeration process for inducing the monomer solution into the pores of the porous membrane was performed. The deaeration treatment was performed for about 3 minutes, the aspirator was stopped, air was sent into the flask, and the pressure was returned to normal pressure.
Next, the lid of the separable flask was opened and a roller was rolled on the porous membrane as if pressed, so that the monomer solution was impregnated into the porous membrane to form a monomer solution-impregnated porous body.
（電解質膜形成）
　モノマー溶液含浸多孔質体を、フラスコから取り出し、鋭利な刃を使ってモノマー溶液含浸多孔質体表面に付着した不必要なモノマー溶液を擦り取った。次に、これをセパラブルフラスコ内に吊るした。セパラブルフラスコの蓋を装着し、フラスコ内を真空ポンプで減圧し、その後、窒素で常圧に戻すことで、フラスコ内の窒素置換を行った。
　次に、窒素置換して密閉したセパラブルフラスコごと約１００℃の恒温槽に設置し、約１０時間加熱を続けることで、モノマー溶液含浸多孔質体内のモノマーの重合反応を行った。
　反応後、フラスコごと室温まで放冷し、その後、蓋を開けてフラスコ内に吊るされた電解質膜を取り出した。このようにして電解質膜を形成した。 (Electrolyte film formation)
The monomer solution-impregnated porous body was taken out of the flask, and unnecessary monomer solution adhering to the surface of the monomer solution-impregnated porous body was scraped off using a sharp blade. This was then suspended in a separable flask. The lid of the separable flask was attached, the inside of the flask was depressurized with a vacuum pump, and then returned to normal pressure with nitrogen to perform nitrogen replacement in the flask.
Next, the separable flask sealed with nitrogen was placed in a constant temperature bath of about 100 ° C., and heating was continued for about 10 hours to carry out the monomer polymerization reaction in the monomer solution-impregnated porous body.
After the reaction, the whole flask was allowed to cool to room temperature, and then the lid was opened and the electrolyte membrane suspended in the flask was taken out. In this way, an electrolyte membrane was formed.
　[実施例２]
　ポリエチレンジアクリレートとして、親水性ユニット数ｎ＝４であるものを用いた以外は、実施例１と同様にして電解質膜を形成した。 [Example 2]
An electrolyte membrane was formed in the same manner as in Example 1 except that polyethylene diacrylate having a hydrophilic unit number n = 4 was used.
　[比較例１]
　Ｎａｆｉｏｎ（商品名、デュポン社製）を、比較例１の電解質膜とした。 [Comparative Example 1]
Nafion (trade name, manufactured by DuPont) was used as the electrolyte membrane of Comparative Example 1.
　[比較例２]
　ポリエチレンジアクリレートの代わりに、メチレンビスアクリルアミド（ＨＬＢ値(グリフィン法)＝３．９６）を用いたこと以外は、実施例１と同様にして、電解質膜を形成した。 [Comparative Example 2]
An electrolyte membrane was formed in the same manner as in Example 1 except that methylene bisacrylamide (HLB value (Griffin method) = 3.96) was used instead of polyethylene diacrylate.
　[評価]
（プロトン伝導率測定）
　実施例１、実施例２、比較例１および比較例２で得られた電解質膜を用いて、プロトン伝導率を測定した。具体的には、周波数１０ｋＨｚで交流インピーダンス測定を行うことにより、プロトン伝導率の測定を行った。なお、インピーダンス測定は、実施例１、実施例２、比較例１および比較例２で得られた電解質膜を、所定の相対湿度（ＲＨ）、８０℃において放置し、平衡状態となった後に行った。実施例１および比較例１について得られたプロトン伝導率（Ｈ＋　Ｃｏｎｄｕｃｔｉｖｉｔｙ（Ｓ／ｃｍ））の相対湿度（ＲＨ（％））依存性を図４に示す。 [Evaluation]
(Proton conductivity measurement)
Using the electrolyte membranes obtained in Example 1, Example 2, Comparative Example 1 and Comparative Example 2, proton conductivity was measured. Specifically, proton conductivity was measured by measuring AC impedance at a frequency of 10 kHz. The impedance measurement was performed after the electrolyte membranes obtained in Example 1, Example 2, Comparative Example 1 and Comparative Example 2 were allowed to stand at a predetermined relative humidity (RH) and 80 ° C. to reach an equilibrium state. It was. FIG. 4 shows the relative humidity (RH (%)) dependence of the proton conductivity (H + Conductivity (S / cm)) obtained for Example 1 and Comparative Example 1.
（イオン交換容量測定）
　実施例１、実施例２の電解質膜、および実施例１、実施例２におけるＰＥＧＤＡの含有量（親水性ユニット含有多官能架橋モノマー重量の、上記親水性ユニット含有多官能架橋モノマーおよび上記スルホン酸基含有ビニルモノマーの合計重量に対する重量％）のみを変化させて得られた電解質膜の熱水試験前のイオン交換容量を測定した。イオン交換容量測定は、滴定装置にて測定した。具体的には、飽和ＮａＣｌ水溶液にて２４時間に亘ってイオン交換し、その後０．０２Ｎ－ＮａＯＨ水溶液にて、フェノールフタレインを指示薬として滴定した（ｐＨ＝７にて滴定）。次に、電解質膜を０．１Ｎ－ＨＣｌ水溶液へ２時間に亘って浸漬し、超純水でリンスし、この後６０℃の環境下で１時間に亘って真空乾燥を実施した。その後、質量測定の結果より、電解質膜のイオン交換容量（ＩＥＣ）を算出した。
　また、実施例１、実施例２の電解質膜、および実施例１、実施例２におけるＰＥＧＤＡの含有量のみを変化させて得られた電解質膜を用いて、１００℃の熱水で１時間攪拌して熱水試験し、熱水試験後のイオン交換容量を測定した。得られた熱水試験前後のイオン交換容量を、ＰＥＧＤＡの含有量に対してプロットしたグラフを、図５および図６に示す。 (Ion exchange capacity measurement)
Electrolyte membrane of Example 1 and Example 2, and content of PEGDA in Example 1 and Example 2 (weight of hydrophilic unit-containing polyfunctional crosslinking monomer, hydrophilic unit-containing polyfunctional crosslinking monomer and sulfonic acid group The ion exchange capacity before the hydrothermal test of the electrolyte membrane obtained by changing only the weight% of the total vinyl monomer content) was measured. The ion exchange capacity was measured with a titrator. Specifically, ion exchange was performed with a saturated NaCl aqueous solution for 24 hours, and then titration was performed with 0.02 N NaOH aqueous solution using phenolphthalein as an indicator (titration at pH = 7). Next, the electrolyte membrane was immersed in a 0.1N HCl aqueous solution for 2 hours, rinsed with ultrapure water, and then vacuum dried at 60 ° C. for 1 hour. Thereafter, the ion exchange capacity (IEC) of the electrolyte membrane was calculated from the result of mass measurement.
Further, using the electrolyte membranes of Examples 1 and 2 and the electrolyte membranes obtained by changing only the PEGDA content in Examples 1 and 2, the mixture was stirred with hot water at 100 ° C. for 1 hour. The hot water test was conducted, and the ion exchange capacity after the hot water test was measured. The graph which plotted the ion exchange capacity before and after the obtained hot-water test with respect to content of PEGDA is shown in FIG. 5 and FIG.
　図４に示すように、実施例１の電解質膜は、標準的な電解質膜Ｎａｆｉｏｎである比較例１を超えるプロトン伝導率を示すことが分かった。また、図示しないが、比較例２においては、ＨＬＢ値が５．０より小さく、疎水性が高いため、良好な架橋構造が形成されず、プロトン伝導率は低い値であった。
　また、図５および図６に示すように、熱水試験前のイオン交換容量（ＩＥＣ）は、実施例１においては、４以上となり、実施例２においては、３以上となり、高い値を示した。また、熱水試験後のイオン交換容量は、実施例１および実施例２のいずれにおいても、親水性ユニット含有多官能架橋モノマーであるポリエチレンジアクリレート（ＰＥＧＤＡ）を増加させることにより、より高い値を示し、熱水試験後のイオン交換容量の低下を抑制することができた。 As shown in FIG. 4, the electrolyte membrane of Example 1 was found to exhibit proton conductivity exceeding that of Comparative Example 1 which is a standard electrolyte membrane Nafion. Although not shown, in Comparative Example 2, since the HLB value was smaller than 5.0 and the hydrophobicity was high, a good crosslinked structure was not formed, and the proton conductivity was a low value.
As shown in FIGS. 5 and 6, the ion exchange capacity (IEC) before the hot water test was 4 or more in Example 1, and 3 or more in Example 2, showing a high value. . Moreover, the ion exchange capacity after the hot water test is higher in both Example 1 and Example 2 by increasing polyethylene diacrylate (PEGDA), which is a hydrophilic functional unit-containing polyfunctional crosslinking monomer. It was possible to suppress the decrease in ion exchange capacity after the hot water test.
　以上の結果から、実施例においては、少なくともスルホン酸基含有ビニルモノマーとＨＬＢ値が５．０以上である親水性ユニット含有多官能架橋モノマーとが重合してなる電解質が、上記電解質の主鎖骨格構造と同一の骨格構造を有する多孔質体に含浸されてなることにより、電解質中の架橋構造を良好なものとすることが可能となり、また、上記電解質と上記多孔質体との親和性を高めることができる。このため、イオン交換容量の保持性が高く、さらに電解質と多孔質体との密着性に優れ、プロトン伝導率が向上した電解質膜を得ることができた。
　また、親水性ユニット含有多官能架橋モノマーの含有量を増加させることにより、架橋構造をより効果的に形成することが可能となり、熱水試験等を行った後においても、より確実にイオン交換基の減少を抑制し、イオン交換容量を高く保持することを可能とすることができた。 From the above results, in the examples, an electrolyte obtained by polymerizing at least a sulfonic acid group-containing vinyl monomer and a hydrophilic unit-containing polyfunctional crosslinking monomer having an HLB value of 5.0 or more is a main chain skeleton of the electrolyte. By being impregnated in a porous body having the same skeleton structure as the structure, it is possible to improve the cross-linked structure in the electrolyte, and to increase the affinity between the electrolyte and the porous body be able to. Therefore, it was possible to obtain an electrolyte membrane having high ion exchange capacity retention, excellent adhesion between the electrolyte and the porous body, and improved proton conductivity.
Further, by increasing the content of the hydrophilic unit-containing polyfunctional crosslinking monomer, it becomes possible to form a crosslinked structure more effectively, and even after a hot water test or the like, the ion exchange group is more reliably formed. It was possible to keep the ion exchange capacity high.
　１　…　モノマー溶液
　２　…　多孔質体
　３　…　ローラー
　４　…　プレス用板
　５　…　プレス装置 DESCRIPTION OF SYMBOLS 1 ... Monomer solution 2 ... Porous body 3 ... Roller 4 ... Plate for press 5 ... Press apparatus

Claims (6)

  1. 　少なくともスルホン酸基含有ビニルモノマーとＨＬＢ値が５．０以上である親水性ユニット含有多官能架橋モノマーとが重合してなる電解質が、前記電解質の主鎖骨格構造と同一の骨格構造を有する多孔質体に含浸されてなることを特徴とする電解質膜。 An electrolyte obtained by polymerizing at least a sulfonic acid group-containing vinyl monomer and a hydrophilic unit-containing polyfunctional crosslinking monomer having an HLB value of 5.0 or more has a porous structure having the same skeleton structure as the main chain skeleton structure of the electrolyte. An electrolyte membrane which is impregnated in a body.
  2. 　前記スルホン酸基含有ビニルモノマーがビニルスルホン酸であり、前記親水性ユニット含有多官能架橋モノマーがポリエチレングリコールジアクリレートであることを特徴とする請求の範囲第１項に記載の電解質膜。 2. The electrolyte membrane according to claim 1, wherein the sulfonic acid group-containing vinyl monomer is vinyl sulfonic acid, and the hydrophilic unit-containing polyfunctional crosslinking monomer is polyethylene glycol diacrylate.
  3. 　前記電解質が、前記スルホン酸基含有ビニルモノマーおよび前記ＨＬＢ値が５．０以上である親水性ユニット含有多官能架橋モノマーのみが重合してなるものであることを特徴とする請求の範囲第１項または第２項に記載の電解質膜。 2. The electrolyte according to claim 1, wherein the electrolyte is obtained by polymerizing only the sulfonic acid group-containing vinyl monomer and the hydrophilic unit-containing polyfunctional crosslinking monomer having an HLB value of 5.0 or more. Or the electrolyte membrane of a 2nd term | claim.
  4. 　前記多孔質体がビニル系骨格構造を有することを特徴とする請求の範囲第１項から第３項までのいずれかに記載の電解質膜。 The electrolyte membrane according to any one of claims 1 to 3, wherein the porous body has a vinyl skeleton structure.
  5. 　前記電解質膜のイオン交換容量が３．０ｍｅｑ／ｇ以上であることを特徴とする請求の範囲第１項から第４項までのいずれかに記載の電解質膜。 The electrolyte membrane according to any one of claims 1 to 4, wherein an ion exchange capacity of the electrolyte membrane is 3.0 meq / g or more.
  6. 　少なくともスルホン酸基含有ビニルモノマーとＨＬＢ値が５．０以上である親水性ユニット含有多官能架橋モノマーとを含むモノマー溶液中に、前記モノマー溶液を重合してなる電解質の主鎖骨格構造と同一の骨格構造を有する多孔質体を浸漬させ、重合反応を抑制した状態で、前記多孔質体に対して機械的な圧力の付加および開放を行うことにより、前記多孔質体中に前記モノマー溶液を含浸させてモノマー溶液含浸多孔質体を得るモノマー溶液含浸工程と、前記モノマー溶液を重合して電解質膜を得る重合工程とを有することを特徴とする電解質膜の製造方法。 The same as the main chain skeleton structure of an electrolyte obtained by polymerizing the monomer solution in a monomer solution containing at least a sulfonic acid group-containing vinyl monomer and a hydrophilic unit-containing polyfunctional crosslinking monomer having an HLB value of 5.0 or more. The porous body is impregnated with the monomer solution by immersing the porous body having a skeletal structure and applying and releasing mechanical pressure to the porous body while suppressing the polymerization reaction. A method for producing an electrolyte membrane comprising: a monomer solution impregnation step for obtaining a monomer solution-impregnated porous body; and a polymerization step for polymerizing the monomer solution to obtain an electrolyte membrane.
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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102637891A (en) * 2012-04-27 2012-08-15 东方电气集团东方汽轮机有限公司 Vanadium cell nafion proton membrane and preparation method thereof
JP2015164976A (en) * 2014-02-28 2015-09-17 富士フイルム株式会社 Ion-exchange membrane and method for producing the same
US9598243B2 (en) 2011-11-04 2017-03-21 Roche Diagnostics Operations, Inc. Laboratory sample distribution system and corresponding method of operation
WO2017219020A1 (en) * 2016-06-17 2017-12-21 Cornell University Cross-linked polymeric material

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5942909B2 (en) * 2013-03-25 2016-06-29 トヨタ自動車株式会社 Manufacturing method and manufacturing apparatus for reinforced electrolyte membrane
JP5831666B1 (en) * 2014-12-12 2015-12-09 東洋インキＳｃホールディングス株式会社 Cell culture components
JP6822101B2 (en) * 2016-11-29 2021-01-27 セイコーエプソン株式会社 Polymer electrolytes, batteries, and electronics

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH02155662A (en) * 1988-12-07 1990-06-14 Matsushita Electric Ind Co Ltd Thermal transfer recorder
JP2004146279A (en) * 2002-10-25 2004-05-20 Toagosei Co Ltd Electrolyte membrane and fuel cell using the electrolyte membrane
JP2006073530A (en) * 2004-08-31 2006-03-16 Samsung Sdi Co Ltd Polymer electrolyte membrane and fuel cell employing the same
JP2006216531A (en) * 2004-12-03 2006-08-17 Nitto Denko Corp Electrolyte membrane and solid polymer fuel cell using the same
JP2007048543A (en) * 2005-08-09 2007-02-22 Toagosei Co Ltd Electrolyte film and direct liquid fuel type fuel cell
WO2007094279A1 (en) * 2006-02-15 2007-08-23 Toagosei Co., Ltd. Method for producing functional membrane
JP2007305371A (en) * 2006-05-10 2007-11-22 Nitto Denko Corp Electrolyte membrane and solid polymer electrolyte fuel cell

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH02155662A (en) * 1988-12-07 1990-06-14 Matsushita Electric Ind Co Ltd Thermal transfer recorder
JP2004146279A (en) * 2002-10-25 2004-05-20 Toagosei Co Ltd Electrolyte membrane and fuel cell using the electrolyte membrane
JP2006073530A (en) * 2004-08-31 2006-03-16 Samsung Sdi Co Ltd Polymer electrolyte membrane and fuel cell employing the same
JP2006216531A (en) * 2004-12-03 2006-08-17 Nitto Denko Corp Electrolyte membrane and solid polymer fuel cell using the same
JP2007048543A (en) * 2005-08-09 2007-02-22 Toagosei Co Ltd Electrolyte film and direct liquid fuel type fuel cell
WO2007094279A1 (en) * 2006-02-15 2007-08-23 Toagosei Co., Ltd. Method for producing functional membrane
JP2007305371A (en) * 2006-05-10 2007-11-22 Nitto Denko Corp Electrolyte membrane and solid polymer electrolyte fuel cell

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9598243B2 (en) 2011-11-04 2017-03-21 Roche Diagnostics Operations, Inc. Laboratory sample distribution system and corresponding method of operation
CN102637891A (en) * 2012-04-27 2012-08-15 东方电气集团东方汽轮机有限公司 Vanadium cell nafion proton membrane and preparation method thereof
JP2015164976A (en) * 2014-02-28 2015-09-17 富士フイルム株式会社 Ion-exchange membrane and method for producing the same
US9790338B2 (en) 2014-02-28 2017-10-17 Fujifilm Corporation Ion exchange membrane and method for manufacturing the same
WO2017219020A1 (en) * 2016-06-17 2017-12-21 Cornell University Cross-linked polymeric material
CN109312030A (en) * 2016-06-17 2019-02-05 康奈尔大学 Cross-linked polymeric material
US10913809B2 (en) 2016-06-17 2021-02-09 Cornell University Cross-linked polymeric material

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