Abstract: To provide a liquid composition capable of forming a membrane excellent in durability against hydrogen peroxide or peroxide radicals and excellent in hydrogen gas barrier property; a polymer electrolyte membrane; a membrane electrode assembly; and a polymer electrolyte fuel cell. Liquid composition comprising a liquid medium, an acid-type sulfonic acid group-containing fluorocarbon polymer of which the hydrogen gas permeation coefficient under the conditions of a temperature of 80° C. and a relative humidity of 10% is at most 2.5×10?9 cm3·cm/(s·cm2·cmHg), and cerium atoms; a polymer electrolyte membrane 15 comprising the acid-type sulfonic acid group-containing fluorocarbon polymer, and cerium atoms; and a membrane electrode assembly 10 comprising an anode 13 having a catalyst layer, a cathode 14 having a catalyst layer, and the polymer electrolyte membrane 15 disposed between the anode 13 and the cathode 14.

Abstract: An acid-type sulfonic acid group-containing polymer containing perfluoromonomer units, no monomer units having a halogen atom other than a fluorine atom, and acid type sulfonic acid groups, whose hydrogen gas permeability coefficient under the conditions of a temperature of 80° C. and a relative humidity of 10% is at most 2.5×10?9 cm3·cm/(s·cm2·cmHg), and whose mass reduction rate when immersed in hot water at 120° C. for 24 hours is at most 15 mass %. Liquid composition, membrane electrode assembly, polymer electrolyte fuel cell, and ion exchange membrane utilizing the acid-type sulfonic acid group-containing polymer.

Abstract: To provide a perfluoropolymer capable of producing an electrolyte membrane excellent in mechanical strength in high temperature environments; as well as a liquid composition, polymer electrolyte membrane, membrane electrode assembly and polymer electrolyte water electrolyzer, obtainable by using the perfluoropolymer. The perfluoropolymer of the present invention contains perfluoromonomer units, does not substantially contain units having a halogen atom other than a fluorine atom, does not substantially contain units having a ring structure, and has acid-type sulfonic acid groups, wherein the perfluoromonomer units contain at least one type of units A selected from the group consisting of perfluorovinyl ether units and perfluoroallyl ether units; the ion exchange capacity is from 0.9 to 1.4 milliequivalent/gram dry resin; and the storage modulus at 120° C. is at least 100 MPa.

Abstract: A fluorosulfonyl group-containing polymer having units represented by the following formula u1, a sulfonic acid group-containing polymer having fluorosulfonyl groups in the fluorosulfonyl group-containing polymer converted into sulfonic acid groups, its production method and its applications: wherein RF1 and RF2 are a C1-3 perfluoroalkylene group.

Abstract: A method for producing a fluorosulfonyl group-containing compound to obtain a compound represented by the following formula 5 from a compound represented by the following formula 1 as a starting material and a method for producing a fluorosulfonyl group-containing monomer in which the fluorosulfonyl group-containing compound is used: wherein R1 and R2 are a C1-3 alkylene group, and RF1 and RF2 are a C1-3 perfluoroalkylene group.

Abstract: A method for producing a fluorosulfonyl group-containing compound to obtain a compound represented by the following formula 5 from a compound represented by the following formula 1 as a starting material and a method for producing a fluorosulfonyl group-containing monomer in which the fluorosulfonyl group-containing compound is used: wherein R1 and R2 are a C1-3 alkylene group, and RF1 and RF2 are a C1-3 perfluoroalkylene group.

Abstract: To provide a polymer wherein a linking group that connects the main chain of the polymer and a cyclic perfluoroaliphatic disulfonimide skeleton, is a fluoroalkylene group which may have an ether oxygen atom. A polymer which has either one or both of units represented by formula u1-1 and units represented by formula u1-2: RF1, RF2: a C1-3 perfluoroalkylene group; RF3: a C1-6 perfluoroalkylene group; m: 0 or 1; and X: a hydrogen atom, an alkali metal atom, a fluorine atom, an alkyl group, ammonium or the like.

Abstract: To provide a perfluoropolymer capable of producing an electrolyte membrane excellent in electrical conductivity and mechanical strength under high temperature environment, as well as a liquid composition, a polymer electrolyte membrane, a membrane electrode assembly and a polymer electrolyte fuel cell, obtainable by using the perfluoropolymer. The perfluoropolymer of the present invention contains perfluoromonomer units, does not substantially contain units having a halogen atom other than a fluorine atom, does not substantially contain units having a ring structure, and has acid-type sulfonic acid groups, wherein the perfluoromonomer units contain at least one type of units A selected from the group consisting of perfluoro vinyl ether units and perfluoro allyl ether units; the ion exchange capacity is from 1.4 to 2.5 milliequivalent/gram dry resin; and the storage modulus at 120° C. is at least 60 MPa.

Abstract: To provide an acid-type sulfonic acid group-containing polymer which is excellent in hydrogen gas barrier properties and hot water resistance and which generates less oligomer during production; a liquid composition and a polymer electrolyte membrane comprising this acid-type sulfonic acid group-containing polymer; and a membrane electrode assembly and a polymer electrolyte fuel cell provided with the polymer electrolyte membrane. This acid-type sulfonic acid group-containing polymer is a polymer which has perfluoromonomer units, no monomer units having a halogen atom other than a fluorine atom, and acid-type sulfonic acid groups, and of which the hydrogen gas permeability coefficient under the conditions of a temperature of 80° C. and a relative humidity of 10%, is at most 2.5×10?9 cm3·cm/(s·cm2·cmHg), and the mass reduction rate when being immersed in hot water at 120° C.

Abstract: To provide a perfluoropolymer capable of producing an electrolyte membrane excellent in mechanical strength in high temperature environments; as well as a liquid composition, polymer electrolyte membrane, membrane electrode assembly and polymer electrolyte water electrolyzer, obtainable by using the perfluoropolymer. The perfluoropolymer of the present invention contains perfluoromonomer units, does not substantially contain units having a halogen atom other than a fluorine atom, does not substantially contain units having a ring structure, and has acid-type sulfonic acid groups, wherein the perfluoromonomer units contain at least one type of units A selected from the group consisting of perfluorovinyl ether units and perfluoroallyl ether units; the ion exchange capacity is from 0.9 to 1.4 milliequivalent/gram dry resin; and the storage modulus at 120° C. is at least 100 MPa.

Abstract: To provide a liquid composition capable of forming a membrane excellent in durability against hydrogen peroxide or peroxide radicals and excellent in hydrogen gas barrier property; a polymer electrolyte membrane; a membrane electrode assembly; and a polymer electrolyte fuel cell. Liquid composition comprising a liquid medium, an acid-type sulfonic acid group-containing fluorocarbon polymer of which the hydrogen gas permeation coefficient under the conditions of a temperature of 80° C. and a relative humidity of 10% is at most 2.5×10?9 cm3·cm/(s·cm2·cmHg), and cerium atoms; a polymer electrolyte membrane 15 comprising the acid-type sulfonic acid group-containing fluorocarbon polymer, and cerium atoms; and a membrane electrode assembly 10 comprising an anode 13 having a catalyst layer, a cathode 14 having a catalyst layer, and the polymer electrolyte membrane 15 disposed between the anode 13 and the cathode 14.

Abstract: The present invention relates to a method for producing a 1,3-dioxolane compound represented by formula 1, the method containing step (a), in which hexafluoroacetone monohydrate is brought into contact with a metal fluoride, step (b), in which fluorine gas is brought into contact, and step (c), in which an olefin compound represented by formula 2 is brought into contact. In formulae 1 and 2, X1 to X4 each independently represent a hydrogen atom, fluorine atom, chlorine atom, or trifluoromethyl group.

Abstract: The present invention relates to a method for producing a 1,3-dioxolane compound represented by formula 1, the method containing step (a), in which hexafluoroacetone monohydrate is brought into contact with a metal fluoride, step (b), in which fluorine gas is brought into contact, and step (c), in which an olefin compound represented by formula 2 is brought into contact. In formulae 1 and 2, X1 to X4 each independently represent a hydrogen atom, fluorine atom, chlorine atom, or trifluoromethyl group.

Abstract: A method for producing a fluorosulfonyl group-containing compound to obtain a compound represented by the following formula 5 from a compound represented by the following formula 1 as a starting material and a method for producing a fluorosulfonyl group-containing monomer in which the fluorosulfonyl group-containing compound is used: wherein R1 and R2 are a C1-3 alkylene group, and RF1 and RF2 are a C1-3 perfluoroalkylene group.

Abstract: A fluorosulfonyl group-containing polymer having units represented by the following formula u1, a sulfonic acid group-containing polymer having fluorosulfonyl groups in the fluorosulfonyl group-containing polymer converted into sulfonic acid groups, its production method and its applications: wherein RF1 and RF2 are a C1-3 perfluoroalkylene group.

Abstract: A method for producing at least one olefin compound selected from the group consisting of a compound of formula (51) and a compound of formula (52), the method including reacting an olefin compound of formula (21) with a olefin compound of formula (31) in the presence of at least one metal catalyst selected from the group consisting of a compound of formula (11), a compound of formula (12), a compound of formula (13), a compound of formula (14), and a compound of formula (15).

Abstract: Provided is a fluorinated ether compound capable of imparting excellent antifouling properties such as oil-based ink repellency, fingerprint stain removability, to a hard coating layer; a composition for forming a hard coating layer, and an article having an antifouling hard coating layer formed from the composition. The fluorinated ether compound has either a poly(oxyperfluoroalkylene) chain having a repeated unit that includes a C1-2 oxyperfluoroalkylene group and a C3-6 oxyperfluoroalkylene group, bonded to each other, or a poly(oxyperfluoroalkylene) chain having a repeated unit that contains a C4 oxyperfluoroalkylene group and a different oxyperfluoroalkylene group, bonded to each other, a linking group bonded to a first terminal of the poly(oxyperfluoroalkylene) chain, and at least one (meth)acryloyl group bonded to the linking group.

Abstract: A method for producing a fluorine-containing polymer includes subjecting at least one kind of fluorine-containing cycloolefin compound selected from the group consisting of a fluorine-containing cycloolefin compound represented by the following formula (41) and a fluorine-containing cycloolefin compound represented by the following formula (42) to ring-opening metathesis polymerization in the presence of a metal-carbene complex compound (10) having an olefin metathesis reaction activity.

Abstract: A method for producing at least one olefin compound selected from the group consisting of a compound of formula (51) and a compound of formula (52), the method including reacting an olefin compound of formula (21) with a olefin compound of formula (31) in the presence of at least one metal catalyst selected from the group consisting of a compound of formula (11), a compound of formula (12), a compound of formula (13), a compound of formula (14), and a compound of formula (15).

Abstract: To provide a fluorinated ether compound, a fluorinated ether composition and a coating liquid, whereby it is possible to form a surface-treated layer which has high initial water/oil repellency and which is excellent in abrasion resistance and fingerprint stain removability, and a substrate having a surface-treated layer and a method for its production. A fluorinated ether compound which has a poly(oxyperfluoroalkylene) chain (??) having a C4 oxyperfluoroalkylene unit (?) and an oxyperfluoroalkylene unit (?) other than the unit (?) and which has a hydrolysable silyl group on at least one terminal of the poly(oxyperfluoroalkylene) chain (??) via a linking group.