Patent ID: 8735479

Claim:
A fluorinated elastic copolymer composition, comprising: a tetrafluoroethylene-propylene elastic copolymer; and a compound of formula (1): (RCOO − ) n M n+ (1) wherein R is a C 10-30 organic group, n is an integer of 2 or 3, and M is an alkaline earth metal, Zn, Cd, Co, Sn, Cu, Pb, Ni or Al, and an organic peroxide, and an amount of the compound of formula (1) is from 0.1 to 10 parts by mass per 100 parts by mass of the tetrafluoroethylene-propylene elastic copolymer and wherein a volume swell ratio in a steam resistance test at 170° C. for 70 hours according to JIS K6258 of a member obtained by press-crosslinking the fluorinated elastic copolymer composition with triallyl isocyanurate is less than 3%.