Patent ID: 7884166

Claim:
An elastic fluorocopolymer comprising repeating units (l) based on at least one fluoromonomer selected from the group consisting of tetrafluoroethylene, hexafluoropropylene, vinylidene fluoride and a perfluorovinyl ether represented by the formula CF 2 ═CF—O—R f (wherein R f is a C 1-8 saturated perfluoroalkyl group or a perfluoro(alkoxyalkyl) group), repeating units (m) based on vinyl crotonate, and optionally, repeating units (n) based on at least one hydrocarbon monomer selected from the group consisting of ethylene, propylene and a vinyl ether represented by the formula CH 2 ═CH—O—R 4 (wherein R 4 is a C 1-8 saturated alkyl group or an alkoxyalkyl group) in a molar ratio of (m)/((l)+(n))=0.0001 to 0.1.