Abstract: By performing photograft polymerization of functional monomers such that grafted chains will be introduced from the surface of a polymer base film into its interior without deteriorating its inherent characteristics and also by creating a multiplex crosslinked structure between the grafted chains and the base film under such conditions as to cause preferential radiation-induced crosslinking reaction, there is produced a polymer electrolyte membrane having high enough oxidation resistance and proton conductivity to be suitable for use in fuel cells.

Abstract: A method for producing a polymer electrolyte membrane for electrolyte fuel cells includes: irradiating gamma rays onto a polymer substrate to obtain a crosslinked polytetrafluoroetylene substrate, grafting a styrenic monomer and bis(vinylphenyl)ethane as monomers to the crosslinked polymer substrate, and introducing sulfonic acid groups into graft side chains formed by grafting. Fluoro polymer substrates such as polytetrafluoroethylene and ethylene tetrafluoroethylene copolymer may be used.

Abstract: Polymer ion-exchange membranes having outstanding electrical conductivity, water retention and oxidation resistance are produced by the steps of uniformly mixing an organic high-molecular weight resin with functional inorganics having the abilities to promote graft polymerization of polymerizable monomers, adsorb water and conduct protons, irradiating the resulting functional inorganics/polymer membrane to initiate graft polymerization or graft copolymerization of polymerizable monomers having functional groups, and then introducing sulfonic acid groups into the graft chains.

Abstract: The objective of the invention is to solve the problems of conventional polymer electrolyte membranes, including small ion-exchange capacity and low oxidation and methanol resistance. A polymer film substrate is irradiated with ?-rays, electron beams or other radiations to perform multi-graft polymerization with functional monomers and then the polymer film substrate containing the grafted molecular chains or the graft molecular chains into which sulfonic acid groups have been introduced is crosslinked by irradiation to produce a polymer electrolyte membrane that has outstanding oxidation resistance, dimensional stability, electrical conductivity and methanol resistance and which can be controlled in ion-exchange capacity over a wide range.

Abstract: Polymer ion-exchange membranes having outstanding electrical conductivity, water retention and oxidation resistance are produced by the steps of uniformly mixing an organic high-molecular weight resin with functional inorganics having the abilities to promote graft polymerization of polymerizable monomers, adsorb water and conduct protons, irradiating the resulting functional inorganics/polymer membrane to initiate graft polymerization or graft copolymerization of polymerizable monomers having functional groups, and then introducing sulfonic acid groups into the graft chains.

Abstract: An aromatic polymer film substrate, or a grafted aromatic polymer film substrate having a monomer introduced therein as graft chains is irradiated with ionizing radiation to impart a crosslinked structure. The aromatic polymer film substrate or the grafted aromatic polymer film substrate, provided with the crosslinked structure, is directly sulfonated to obtain a crosslinked aromatic polymer electrolyte membrane. The crosslinked aromatic polymer electrolyte membrane has low water uptake, high proton conductivity, low methanol permeability, high chemical stability, and excellent mechanical characteristics.

Abstract: An aromatic polymer film substrate, or a grafted aromatic polymer film substrate having a monomer introduced therein as graft chains is irradiated with ionizing radiation to impart a crosslinked structure. The aromatic polymer film substrate or the grafted aromatic polymer film substrate, provided with the crosslinked structure, is directly sulfonated to obtain a crosslinked aromatic polymer electrolyte membrane. The crosslinked aromatic polymer electrolyte membrane has low water uptake, high proton conductivity, low methanol permeability, high chemical stability, and excellent mechanical characteristics. A method for producing the crosslinked aromatic polymer electrolyte membrane is also provided.

Abstract: An object is to provide an electrolyte membrane that maintains excellent cell characteristics for a long time under high temperature and low water retention, as this is the most important point in fuel cells. A process for producing a polymer electrolyte membrane for fuel cells is provided, which process comprises in sequence: forming graft molecular chains by graft-polymerization of a vinyl silane coupling agent on a polymer film substrate that has phenyl groups capable of holding sulfonic acid groups; introducing sulfonic acid groups into phenyl groups contained in the graft molecular chains; and hydrolyzing and condensing alkoxy groups contained in the graft molecular chains so that a silane crosslinked structure is introduced between the graft molecular chains. A polymer electrolyte membrane produced by the process is also provided.

Abstract: A vinyl monomer is graft polymerized on an aromatic hydrocarbon-based polymer film substrate to introduce graft chains into the substrate and thereafter a functional monomer represented by the following formula and having sulfonic acid groups or functional groups capable of conversion to sulfonic acid groups is graft polymerized to introduce the sulfonic acid groups or the functional groups capable of conversion to sulfonic acid groups: where R is an aromatic ring or an aliphatic chain; X is (1) —OH, (2) —OLi, —ONa or —OK, (3) —F or —Cl, or (4) —OCnH2n+1 where n is an integer of 1 to 7. Since the graft chains obtained by graft polymerization of the vinyl monomer can also be utilized as scaffold polymers, the graft polymerizability of the functional monomer to the aromatic hydrocarbon-based polymer film substrate is sufficiently improved to enable the preparation of a polymer electrolyte membrane that excels not only in proton conductivity and mechanical strength but also in dimensional stability.

Abstract: An aromatic polymer film substrate, or a grafted aromatic polymer film substrate having a monomer introduced therein as graft chains is irradiated with ionizing radiation to impart a crosslinked structure. The aromatic polymer film substrate or the grafted aromatic polymer film substrate, provided with the crosslinked structure, is directly sulfonated to obtain a crosslinked aromatic polymer electrolyte membrane. The crosslinked aromatic polymer electrolyte membrane has low water uptake, high proton conductivity, low methanol permeability, high chemical stability, and excellent mechanical characteristics. A method for producing the crosslinked aromatic polymer electrolyte membrane is also provided.

Abstract: A functional membrane and a production method thereof including: an ion irradiation step in which a polymer film substrate is irradiated with high energy heavy ions at 10 4 to 10 14 ions/cm2, to generate active species in the film substrate; and a graft polymerization step in which after the ion irradiation step, the film substrate is added with one or more monomers selected from a group A consisting of monomers each having a functional group and 1 to 80 mol % of a monomer including a group B consisting of a crosslinking agent(s) for the group A monomer(s), and the film substrate and the monomer(s) are graft-polymerized. There is obtained a functional membrane having high functionality in conjunction with the gas barrier property intrinsically possessed by a polymer film substrate, in particular, a polymer electrolyte membrane optimal as a polymer electrolyte membrane for use in fuel cells, high in proton conductivity and excellent in gas barrier property.

Abstract: A functional membrane is provided, which has high functionality combined with the gas barrier performance and mechanical strength inherent in a polymer film substrate. In particular, a polymer electrolyte membrane is provided, which is excellent in terms of high proton conductivity and gas barrier performance and is most appropriate to serve as a polymer electrolyte membrane for fuel cells. A method for producing a functional membrane is provided, which comprises: a step of ion irradiation, in which active species are generated in a polymer film substrate containing nonconductive inorganic particles by irradiating the polymer film substrate with high-energy heavy ions to the extent of 104/cm2 to 1014/cm2; and a step of graft polymerization subsequent to the step of ion irradiation, in which one or more monomers selected from group A consisting of monomers containing useful functional groups are added such that the monomers are graft polymerized with the polymer film substrate.

Abstract: A polymer film substrate is irradiated with ions to make a large number of nano-sized through-holes and the substrate is further irradiated with an ionizing radiation so that a functional monomer is grafted or co-grafted onto a surface of the film and within the holes; in addition, the sulfonic acid group is introduced into the graft chains, thereby producing a polymer ion-exchange membrane that has high oxidation resistance, dimensional stability, electrical conductivity and methanol resistance, as well as an ion-exchange capacity controlled over a wide range.

Abstract: By performing photograft polymerization of functional monomers such that grafted chains will be introduced from the surface of a polymer base film into its interior without deteriorating its inherent characteristics and also by creating a multiplex crosslinked structure between the grafted chains and the base film under such conditions as to cause preferential radiation-induced crosslinking reaction, there is produced a polymer electrolyte membrane having high enough oxidation resistance and proton conductivity to be suitable for use in fuel cells.

Abstract: A crosslinked nano-inorganic particle/polymer electrolyte membrane composed of a polymer film substrate, graft molecular chains bound to the backbone skeleton of the polymer film substrate and comprising a vinyl monomer graft-polymerized, sulfonic groups bound to the graft molecular chains, and an inorganic material as nano-scale particles uniformly dispersed within a crosslinked structure ascribed to the backbone skeleton of the polymer film substrate and the graft molecular chains, wherein the backbone skeleton of the polymer film substrate, the graft molecular chains, and the nano-inorganic particles mutually construct a crosslinked structure.

Abstract: A polymer electrolyte membrane produced by a process in which a monofunctional vinyl monomer into which sulfonic acid groups can be introduced and a vinyl monomer having a halogen at a terminal are co-grafted into a polymer base film that has been exposed to an ionizing radiation, and the base film is exposed again to an ionizing radiation and/or heat treated so that the terminal halogen is eliminated to introduce a crosslinking structure in which the graft molecular chains are bound together.

Abstract: Polymer ion-exchange membranes having outstanding electrical conductivity, water retention and oxidation resistance are produced by the steps of uniformly mixing an organic high-molecular weight resin with functional inorganics having the abilities to promote graft polymerization of polymerizable monomers, adsorb water and conduct protons, irradiating the resulting functional inorganics/polymer membrane to initiate graft polymerization or graft copolymerization of polymerizable monomers having functional groups, and then introducing sulfonic acid groups into the graft chains.

Abstract: The objective of the invention is to solve the problems of conventional polymer electrolyte membranes, including small ion-exchange capacity and low oxidation and methanol resistance. A polymer film substrate is irradiated with ?-rays, electron beams or other radiations to perform multi-graft polymerization with functional monomers and then the polymer film substrate containing the grafted molecular chains or the graft molecular chains into which sulfonic acid groups have been introduced is crosslinked by irradiation to produce a polymer electrolyte membrane that has outstanding oxidation resistance, dimensional stability, electrical conductivity and methanol resistance and which can be controlled in ion-exchange capacity over a wide range.

Abstract: The improved electrolyte membrane which is produced by grafting a styrenic monomer and bis(vinylphenyl)ethane as monomers to a polymer substrate and then introducing sulfonic acid groups into the graft side chains formed has improved oxidation resistance and good adhesion to electrodes. The polymer substrate is preferably made of a fluorocarbon polymer or an olefinic polymer. The styrenic monomer is preferably one or more species selected from the group consisting of styrene, ?-methylstyrene, vinyltoluene, and trifluorostyrene.

Abstract: A polymer film substrate is irradiated with ions to make a large number of nano-sized through-holes and the substrate is further irradiated with an ionizing radiation so that a functional monomer is grafted or co-grafted onto a surface of the film and within the holes; in addition, the sulfonic acid group is introduced into the graft chains, thereby producing a polymer ion-exchange membrane that has high oxidation resistance, dimensional stability, electrical conductivity and methanol resistance, as well as an ion-exchange capacity controlled over a wide range.