Abstract: A compound containing two fluorosulfonyl groups which are groups convertible to sulfonic acid groups, an intermediate therefor, and methods for their production with high productivity, are provided. Also provided are a fluorosulfonyl group-containing polymer obtained by polymerizing such a compound, and a sulfonic acid group-containing polymer obtained from such a polymer.

Abstract: A membrane-electrode assembly for polymer electrolyte fuel cells which is excellent in water repellency and gas diffusivity and which exhibits a high output power density, can be obtained by using, as an electrolyte material for polymer electrolyte fuel cells, a fluoropolymer obtained by contacting a fluoropolymer which is excellent in gas diffusivity and which has alicyclic structures in its main chain and further has sulfonic acid groups, with fluorine gas for fluorination to increase water repellency and stabilize the molecule ends.

Abstract: A compound containing two fluorosulfonyl groups which are groups convertible to sulfonic acid groups, an intermediate therefor, and methods for their production with high productivity, are provided. Also provided are a fluorosulfonyl group-containing polymer obtained by polymerizing such a compound, and a sulfonic acid group-containing polymer obtained from such a polymer.

Abstract: An electrolyte membrane for a polymer electrolyte fuel cell, which comprises an ion exchange membrane made of a fluoropolymer having a softening temperature of at least 90° C. and having acidic groups, and contains cerium atoms.

Abstract: To provide an electrolyte polymer for polymer electrolyte fuel cells, made of a perfluorinated polymer having sulfonic groups, characterized in that in a test of immersing 0.1 g of the polymer in 50 g of a fenton reagent solution containing 3% of an aqueous hydrogen peroxide solution and 200 ppm of bivalent iron ions at 40° C. for 16 hours, the amount of eluted fluorine ions detected in the solution is not more than 0.002% of the total amount of fluorine in the polymer immersed. The electrolyte polymer of the present invention has very few unstable terminal groups and has an excellent durability, and therefore, is suitable as a polymer constituting an electrolyte membrane for polymer electrolyte fuel cells and a polymer contained in a catalyst layer.

Abstract: To provide a fluorosulfonyl group-containing monomer having a high polymerization reactivity and plural fluorosulfonyl groups. Further, to provide a fluorosulfonyl group-containing polymer and a sulfonic acid group-containing polymer, obtained by using the monomer. A perfluoro(2-methylene-1,3-dioxolane) derivative which is represented by the following formula (3) and which has two fluorosulfonyl groups, and its production process and its synthetic intermediate. A fluorosulfonyl group-containing polymer having monomer units represented by the following formula (3U) obtained by polymerizing the compound (3) by itself or with a comonomer, and a sulfonic acid group-containing polymer having the following units (5U) obtained by hydrolyzing a fluorosulfonyl group of the polymer. In the following formulae, each of Rf1 and Rf2 which are independent of each other, is a C1-8 perfluoroalkylene group which may have an etheric oxygen atom between carbon atoms.

Abstract: To provide an electrolyte polymer for polymer electrolyte fuel cells, made of a perfluorinated polymer having sulfonic groups, characterized in that in a test of immersing 0.1 g of the polymer in 50 g of a fenton reagent solution containing 3% of an aqueous hydrogen peroxide solution and 200 ppm of bivalent iron ions at 40° C. for 16 hours, the amount of eluted fluorine ions detected in the solution is not more than 0.002% of the total amount of fluorine in the polymer immersed. The electrolyte polymer of the present invention has very few unstable terminal groups and has an excellent durability, and therefore, is suitable as a polymer constituting an electrolyte membrane for polymer electrolyte fuel cells and a polymer contained in a catalyst layer.

Abstract: A polymer electrolyte fuel cell comprising a membrane-form polymer electrolyte, a cathode disposed on one side of the polymer electrolyte, and an anode disposed on the other side of the polymer electrolyte, wherein the cathode comprises a catalyst and an ion exchange resin, and the ion exchange resin is made of a polymer comprising the following segments A and segments B: Segments A: segments made of a polymer having sulfonic acid groups; and Segments B: segments made of a fluoropolymer having substantially no ion exchange groups.

Abstract: A fluorosulfonyl group-containing compound having a high polymerization reactivity, a process for its production, a sulfonyl group-containing polymerizable monomer led from the sulfonyl group-containing compound, and a polymer obtainable by polymerizing the sulfonyl group-containing polymerizable monomer, are provided. A compound (3) is fluorinated to form a compound (4), and then, the compound (4) is subjected to a decomposition reaction to produce a compound (5). A preferred compound (5-1) of the compound (5) is thermally decomposed to produce a compound (7-1) having a high polymerization reactivity. wherein RA is a bivalent organic group such as a fluoroalkylene group, RAF is a group having RA fluorinated, or the same group as RA, each of RB to RD which are independent of one another, is a hydrogen atom, etc., each of RBF to RDF is a fluorine atom, etc.

Abstract: The present invention provides a polymer electrolyte material comprising a polymer having a repeating unit based on an alicyclic fluoromonomer having a carbon-carbon double bond with radical polymerization reactivity, wherein either of carbon atoms at both ends of the double bond constitutes a ring structure; the repeating unit contains a strongly acidic group such as a sulfonic acid group; the polymer is preferably perfluorinated. This electrolyte material has a high softening temperature and a polymer electrolyte fuel cell using this electrolyte material can be operated at higher temperatures than before. Furthermore, when this electrolyte material is used for a catalyst layer of a cathode in a polymer electrolyte fuel cell, an output voltage of the cell can be increased.

Abstract: It is to provide a process for producing a polymer for an electrolyte material to prepare polymer electrolyte fuel cells which can be operated at a high temperature and with which high output can be obtained, with a stable composition. A process for producing a fluoropolymer by polymerization reaction of tetrafluoroethylene and a fluoromonomer represented by the following formula (m), wherein the polymerization reaction is carried out by continuously charging the reactor with tetrafluoroethylene and the fluoromonomer: wherein m1 is an integer of from 1 to 6.

Abstract: A compound containing two fluorosulfonyl groups which are groups convertible to sulfonic acid groups, an intermediate therefor, and methods for their production with high productivity, are provided. Also provided are a fluorosulfonyl group-containing polymer obtained by polymerizing such a compound, and a sulfonic acid group-containing polymer obtained from such a polymer.

Abstract: To provide a polymer electrolyte material for polymer electrolyte fuel cells, which is an electrolyte material having a high ion exchange capacity and a low resistance, and which has a higher softening temperature than a conventional electrolyte material.

Abstract: A solid polymer electrolyte material made of a copolymer comprising a repeating unit based on a fluoromonomer A which gives a polymer having an alicyclic structure in its main chain by radical polymerization, and a repeating unit based on a fluoromonomer B of the following formula (1): CF2?CF(Rf)jSO2X??(1) wherein j is 0 or 1, X is a fluorine atom, a chlorine atom or OM {wherein M is a hydrogen atom, an alkali metal atom or a group of NR1R2R3R4 (wherein each of R1, R2, R3 and R4 which may be the same or different, is a hydrogen atom or a monovalent organic group)}, and Rf is a C1-20 polyfluoroalkylene group having a straight chain or branched structure which may contain ether oxygen atoms.

Abstract: A fluorosulfonyl group-containing compound having a high polymerization reactivity, a process for its production, a sulfonyl group-containing polymerizable monomer led from the sulfonyl group-containing compound, and a polymer obtainable by polymerizing the sulfonyl group-containing polymerizable monomer

Abstract: To provide an electrolyte material for polymer electrolyte fuel cells having a high softening temperature and being excellent in durability, and an electrolyte membrane and a process for producing a membrane-electrode assembly using it. An electrolyte material made of a polymer containing a segment A of a polymer containing repeating units based on a perfluoromonomer having an ion exchange group and having a polymerizable double bond, at least one of carbon atoms in the polymerizable double bond being a carbon atom contained in an alicyclic structure, and a segment B of a fluoropolymer containing substantially no ion exchange group, and an electrolyte membrane and a membrane-electrode assembly using it.

Abstract: A solid polymer electrolyte material made of a copolymer comprising a repeating unit based on a fluoromonomer A which gives a polymer having an alicyclic structure in its main chain by radical polymerization, and a repeating unit based on a fluoromonomer B of the following formula (1): CF2?CF(Rf)jSO2X??(1) wherein j is 0 or 1, X is a fluorine atom, a chlorine atom or OM {wherein M is a hydrogen atom, an alkali metal atom or a group of NR1R2R3R4 (wherein each of R1, R2, R3 and R4 which may be the same or different, is a hydrogen atom or a monovalent organic group)}, and Rf is a C1-20 polyfluoroalkylene group having a straight chain or branched structure which may contain ether oxygen atoms.

Abstract: A membrane-electrode assembly for polymer electrolyte fuel cells which is excellent in water repellency and gas diffusivity and which exhibits a high output power density, can be obtained by using, as an electrolyte material for polymer electrolyte fuel cells, a fluoropolymer obtained by contacting a fluoropolymer which is excellent in gas diffusivity and which has alicyclic structures in its main chain and further has sulfonic acid groups, with fluorine gas for fluorination to increase water repellency and stabilize the molecule ends.

Abstract: To present an electrolyte material having a high softening temperature, which is useful for obtaining a polymer electrolyte fuel cell which can be operated at a high temperature and whereby a high output power can be obtained with little catalyst poisoning. An electrolyte material for polymer electrolyte fuel cells, which is made of a polymer containing repeating units based on a fluoromonomer having a radical polymerization reactivity, wherein the repeating units contain a 5-membered ring (which may contain 1 or 2 oxygen atoms), of which at least one carbon atom is contained in the main chain of the polymer, and an ionic group such as a sulfonic acid group which is bonded to the 5-membered ring directly or via a perfluoroalkylene group having a linear or branched structure; and the polymer has a softening temperature of at least 120° C.

Abstract: To provide an electrolyte polymer for polymer electrolyte fuel cells, made of a perfluorinated polymer having sulfonic groups, characterized in that in a test of immersing 0.1 g of the polymer in 50 g of a fenton reagent solution containing 3% of an aqueous hydrogen peroxide solution and 200 ppm of bivalent iron ions at 40° C. for 16 hours, the amount of eluted fluorine ions detected in the solution is not more than 0.002% of the total amount of fluorine in the polymer immersed. The electrolyte polymer of the present invention has very few unstable terminal groups and has an excellent durability, and therefore, is suitable as a polymer constituting an electrolyte membrane for polymer electrolyte fuel cells and a polymer contained in a catalyst layer.