摘要 |
The resistance of a fluorinated silicone elastomer to the effects of exposure to hot fuel, hot oil, and elevated temperature has been improved by the addition of from 0.8 to 5 parts by weight of polytetrafluoroethylene powder to a curable fluorinated silicone elastomeric composition, consisting essentially of a fluorinated polydiorganosiloxane gum having from 45 to 50 percent of the organic radicals being 2-(perfluoroalkyl)ethyl radicals, from 50 to 55 percent of the organic radicals being monovalent hydrocarbon radicals with from 0.1 to 1 percent of the monovalent hydrocarbon radicals being aliphatic unsaturated radicals, and a treated reinforcing silica filler. The resistance is further improved by also including an alkaline earth metal oxide or hydroxide acid acceptor. |