Patent ID: 8044145

Claim:
A cross-linkable fluoroelastomer having a Mooney viscosity of from 20 to 300, obtained by heat treating a mixture of a fluoroelastomer (A) and an organic peroxide (B) at a temperature of from 110 to 380° C. for from 10 seconds to 3 hours, wherein the cross-linkable fluoroelastomer has an absorption peak at from 1,640 to 1,700 cm −1 , wherein the intensity of the absorption peak at from 1,640 to 1,700 cm −1 of the infrared absorption spectrum as represented by absorbance of a hot pressed sample having a thickness of 0.2 mm is from 0.05 to 1.5, and wherein after the heat treating the cross-linkable fluoroelastomer has more unsaturated carbon-carbon bonds than the fluoroelastomer (A), wherein the fluoroelastomer (A) is a tetrafluoroethylene/propylene copolymer.