Electrically conductive silicone compositions have been described in the art. For example, Ehrreich et al., in U.S. Pat. No. 3,609,104 discloses a method of making an electrically conductive plastic article, the method comprising providing a first mixture of pressure distortable, cured thermosetting resin particles and an uncured thermosetting resin, providing a second mixture comprising the first mixture and metallic particles sufficient in quantity to provide electrical conductivity in said article, applying pressure to said second mixture thereby to distort said cured particles and reduce the interstices between them, curing said uncured resin while said second mixture is under pressure, and forming said article from said second mixture. Ehrreich et al. further disclose that the cure particles can be of a silicone resin, that the uncured resin can be a silicone resin, and that the cure particles can be particles of the pressure-distortable silicone foam.
Japanese Patent Application Laid-Open No. 61-108661 (108,661/1986) discloses an electrically conductive silicone rubber composition obtained by blending an already vulcanized silicone rubber particulate into a carbon black-loaded silicone rubber base, where the silicone rubber base may be composed of an organopolysiloxane which contains substituted or unsubstituted monovalent hydrocarbon groups such as alkyl groups exemplified by methyl, or alkenyl groups exemplified by vinyl or allyl. J'661 also discloses that the already vulcanized silicone rubber particulate may be afforded by addition reaction upon heating in the presence of a platinum catalyst.
Japanese Patent Application Laid-Open No. 5-314812 (314,812/1993) discloses an electrically conductive resin paste that contains modified bisphenol A diglycidyl ether epoxy resin that is modified with carboxyl-terminated butadiene-nitrile copolymer rubber or amino-terminated butadiene-nitrile copolymer rubber, addition reaction-type silicone resin, silver powder, a curing agent, a curing accelerator, and a solvent which can be a reactive diluent, a non-reactive diluent, or a plasticizer.
Fukuda et al. in U.S. Pat. No. 5,082,596 discloses an electroconductive silicone rubber composition comprising a uniform blend of a diorganopolysiloxane containing alkyl groups, cycloalkyl groups, alkenyl groups, or aryl groups, a cured silicone rubber in the form of a powder of which the particles have a spherical configuration, carbon black in an amount sufficient to impart electroconductivity to the composition, and a curing agent.
Nakano et al. in U.S. Pat. No. 5,229,037 discloses electroconductive silicone rubber compositions which comprises as a blend a diorganopolysiloxane containing alkyl groups , cycloalkyl groups, alkenyl groups, or aryl groups, spherical particles of a cured silicone elastomer, a metallic electroconductivity-imparting agent, and a curing agent of a silicone rubber in an amount sufficient to cure the composition. Nakano et al. also discloses that the silicone rubber composition may further comprise up to 20 parts by weight of a liquid organosilicon compound.