Patent ID: 7482388
Filing Date: 2009-01-27
Classification: B01D,C08J,H01M,Y02E

Abstract:
1. A polymer electrolyte membrane for a polymer electrolyte fuel cell comprising a fluorine polymer substrate having grafted thereon vinyl monomers having sulfone groups as a cation-exchange group, wherein a main chain of the graft chain comprises a hydrocarbon or a partially fluorinated hydrocarbon, and sulfone groups or substituents having sulfone groups are bonded to the main chain through a C—C single bond as a side chain, and wherein the monomer is represented by formula (1) wherein X represents H, hydrocarbon or F; when X is H, R wherein R when X is CH when X is F, R wherein in element compositional ratio by X-ray photoeletron spectroscopy (“ESCA”), at least one surface of the polymer eletrolyte membrane has O/S value of 5.0 or higher, and a surface element proportion of S is 0.4-5.0%.