摘要 |
<p>IMPROVED SOLVENT RESISTANT VULCANIZABLE SILICONE RUBBER COMPOSITION Solvent resistant, room temperature vulcanizable silicone rubber compositions are improved by blending a siloxane resin of the type having silsesquioxane units containing a perfluorinated alkyl ethyl radical thereon with a vinyl-containing polymer and a hydride-containing resin or a hydrogen-containing polysiloxane as a cross-linking agent. The solvent resistant room temperature vulcanizable silicone rubber compositions also contain a catalyst, such as, a platinum catalyst. The compositions optionally contain filler. An example of the siloxane resin having silsesquioxane units and perfluorinated alkyl radical thereon is R"SiO1.5 wherein R" is a (-CH2-)aR' radical where R' is perfluoroalkyl of 1 to about 8 carbon atoms, a is at least 2 but less than 10, and (-CH2-)a is a straight or branched chain, and in a preferred embodiment, R' is -CF3, and a is 2, and the R"SiO1.5 is derived from 3,3,3-trifluoropropyltrichlorosilane.</p> |