Patent ID: 7105619

Claim:
A fluorine-containing copolymer obtained by copolymerizing tetrafluoroethylene, hexafluoropropylene and optionally perfluoro vinyl ether as component monomers, wherein a weight ratio of tetrafluoroethylene, hexafluoropropylene and perfluoro vinyl ether units constituting said fluorine-containing copolymer is 70 to 95: 5 to 20: 0 to 10, respectively; said fluorine-containing copolymer having: a melt flow rate of 30 (g/10 minutes) or more; a volatile content index of 0.2% by weight or less; and a stress relaxation modulus G(t) (unit: dyn/cm 2 ) which satisfies the following formula at t =0.1 second when measured at a temperature of 310° C.: G (0.1)>7×10 6 ×X −1.62 −3000 where X denotes the melt flow rate (unit: g/10 minutes).