摘要 |
Siloxane foams can be prepared by mixing an organohydrogensiloxane, a hydroxylated organosiloxane and a platinum catalyst in amounts such that the ratio of silicon-bonded hydrogen atoms to silicon-bonded hydroxyl radicals is from 2.5 to 7 and thereafter allowing the mixture to foam. The amount of open-cell structure in the foam can be increased by having present in the mixture an organomonohydrogensiloxane such that the molar ratio of silicon-bonded hydrogen atoms from the organohydrogensiloxane to silicon-bonded hydrogen atoms from the organomonohydrogensiloxane is from 0.4 to 2. The siloxane foams can be made to have an increased fire retardant property by adding 0.01 to 2 parts by weight carbon black based on the weight of the total composition. Siloxane foams are also prepared from mixing an organohydrogensiloxane, an organomonohydrogensiloxane, a hydroxylated organosiloxane, a vinyl containing triorganosiloxy endblocked polydiorganosiloxane and a platinum catalyst. These foams can be used for cushioning, in acoustical applications and protective filling or coating applications and especially applications wherein fire retarding is important.
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