BONDING SILICONE RUBBER

A mixture comprising a polydiorganosiloxane gum, filler, ethylpolysilicate, and acryloxyalkylsilane is useful as an adhesion additive for heat activated organic peroxide vulcanizable silicone rubber compositions. Silicone rubber compositions, containing the adhesion additive, bond to the surface of substrates when vulcanized while in contact with the substrate. The silicone rubber composition bonds to a wide variety of substrates with sufficient strength to cause cohesive type failures when the rubber separated from the substrate.