Patent ID: 7312289

Claim:
A fluorine-containing elastomer having a copolymer composition, which comprises 50-85% by mole of (a) vinylidene fluoride, 0-25% by mole of (b) tetrafluoroethylene, 7-20% by mole of (c) perfluoro(methyl vinyl ether), 2.2-15% by mole of (d) CF 2 ═CFO[CF 2 CF(CF 3 )O] n CF 3 , where n is an integer of 4-6, and 0.1-2% by mole of (e) RfX, where Rf is an unsaturated fluorocarbon group having 2-8 carbon atoms, which may contain at least one ether group, and X is a bromine or iodine atom.