Fluorosilicone rubber compositions

A fluorosilicone rubber composition comprising

• (A) 100 parts by weight of an organopolysiloxane represented by the following average compositional formula (1):
• R1aR2bR3cSiO(4-a-b-c)/2 (1)
• wherein R1 is trifluoropropyl, R2 is a substituted or unsubstituted, monovalent, aliphatic unsaturated hydrocarbon group having 2 to 8 carbon atoms, R3 is an unsubstituted, monovalent, aliphatic saturated hydrocarbon or aromatic hydrocarbon group having 1 to 8 carbon atoms, “a” is a positive number of 0.96 to 1.01, “b” is a positive number of 0.0001 to 0.01, “c” is a positive number of 0.96 to 1.06, and the sum of a+b+c is 1.98 to 2.02, and having a viscosity of at least 10,000 cs at 25° C.,
• (B) 5 to 100 parts by weight of a silica filler,
• (C) 0.01 to 5 parts by weight of an organic peroxide of the following general formula (2) or (3):
• wherein each of R4 and R5, which are the same or different, is a monovalent hydrocarbon group having 3 to 10 carbon atoms,
• wherein each of R6 and R8, which are the same or different, is a monovalent hydrocarbon group having 3 to 10 carbon atoms, and R7 is a divalent hydrocarbon group of 2 to 8 carbon atoms which may contain an oxygen atom, and
• (D) 0.01 to 2 parts by weight of a co-crosslinking agent having a molecular weight of up to 10,000 and bearing in a molecule at least two substituents selected from the group consisting of allyl, acryloyl, methacryloyl, epoxy and alkoxy groups, at least one of the substituents being selected from the group consisting of allyl, acryloyl, methacryloyl and epoxy groups.