Patent ID: 6998454
Filing Date: 2006-02-14
Classification: C08F,C08L,Y10T

Abstract:
1. A process for lowering permeability to liquid chemical, which comprises molding a fluorine-containing resin material comprising 85 to 95.5% by mole of a repeating unit from tetrafluoroethylene, 5 to 10% by mole of a repeating unit from hexafluoropropylene and 0.1 to 5% by mole of a repeating unit from at least one higher perfluoro(vinyl ether) represented by the formula (1): wherein Rf 1 is a perfluoroalkyl group having 5 to 10 carbon atoms or a perfluoro(alkoxyalkyl) group having 4 to 17 carbon atoms, wherein said liquid chemical is nitric acid, and said molded fluorine-containing resin material has a permeability to nitric acid of at most 9.0×10 −7 g.cm 2.