Abstract: Curable polyorganosiloxane compositions that can be cured to yield readily deformable, tough, elastomeric gels comprise a liquid triorganosiloxy endblocked polydimethylsiloxane containing terminal vinyl radicals, a resinous organosiloxane polymer containing dimethylvinylsiloxy, trimethylsiloxy and SiO.sub.4/2 groups, a polyorganosiloxane containing at least 3 silicon-bonded hydrogen atoms per molecule, a substantially linear polydimethylsiloxane containing dimethylhydrogensiloxy terminal groups and a catalyst to promote curing of said composition. Gels prepared using preferred embodiments of these curable compositions are transparent and useful as pressure sensitive optical waveguides.

Abstract: Curable polyorganosiloxane compositions that can be cured to yield readily deformable, tough, elastomeric gels comprise a liquid triorganosiloxy endblocked polydimethylsiloxane containing terminal vinyl radicals, a resinous organosiloxane polymer containing dimethylvinylsiloxy, trimethylsiloxy and SiO.sub.4/2 groups, a polyorganosiloxane containing at least 3 silicon-bonded hydrogen atoms per molecule, a substantially linear polydimethylsiloxane containing dimethylhydrogensiloxy terminal groups and a catalyst to promote curing of said composition. Gels prepared using preferred embodiments of these curable compositions are transparent and useful as pressure sensitive optical waveguides.

Abstract: Bubble formation at the interface between an organosiloxane gel that is curable by a hydrosilation reaction and a substrate possessing potential nucleation sites for bubbles can be prevented if the substrate is first coated with an uncured extrudable silicone rubber composition that is curable by hydrosilation reaction in addition to being compatible with and adherent to the gel. The gel is then applied over the uncured silicone rubber composition and the two materials are concurrently cured. The cured rubber composition exhibits a durometer hardness value of at least 10 on the Shore A scale.

Abstract: The processibility of high viscosity, marginally extrudable polyorganosiloxane compositions containing a reinforcing silica filler and a filler treating agent to prevent crepe hardening of the compositions is improved by the presence in said treating agent of at least one component that is incompatible with the polydimethylsiloxane portion of the curable composition prior to the reaction of said component with the filler.