Fluorine-containing copolymers and films thereof

摘要

A fluorine-containing copolymer comprising monomeric units of (a) tetrafluoroethylene, (b) 8 to 15% by weight of hexafluoropropene on the basis of the weight of the copolymer, and (c) 0.2 to 2% by weight of a fluoroalkyl vinyl ether of the formula: CF2=CF-O-(CF2)n-CF2X (I) wherein X is hydrogen or fluorine, and n is an integer of 3 to 9 on the basis of the weight of the copolymer, which has improved stress crack resistance, and flex resistance as well as good moldability.