Patent ID: 7964667

Claim:
A gasket, comprising: (a) cured elastomer cured from a polymeric admixture of fluoroelastomer and fluorinated silicone polymer, the fluorinated silicone comprising a polysiloxane having a Williams plasticity of between about 250 and about 300, and that comprises 3,3,3-trifluoropropyl groups in a sufficient number to provide between about 1 to about 43 weight percent fluorine in the polymer; (b) wherein said gasket has a vaporous hydrocarbon permeation rate value of not greater than 25 gm-mm/m 2 /day, determined according to ASTM D-814, and a thermal strain value of not less than 80 percent at a temperature of not less than 150 degrees Celsius, determined according to ASTM D-412.