Patent ID: 7311989
Filing Date: 2007-12-25
Classification: C08J,H01M,Y02E,Y02P

Abstract:
1. A polymer membrane having a thickness of 50 μm or less, mainly made of an ion exchange resin which further comprises melt-spun fluororesin fibers having fiber diameters of from 0.01 to 20 μm, fiber lengths of from 1 μm to 10 mm and aspect ratios of at least 5 in an amount of from 1 to 40% based on the total mass, wherein the melt-spun fluororesin fibers are made of at least one member selected from the group consisting of an ethylene-tetrafluoroethylene copolymer, a tetrafluoroethylene-perfluoro(alkyl vinyl ether) polymer, and a tetrafluoroethylene-hexafluoropropylene copolymer.