Process for the preparation of organopolysiloxane foams
AssigneeWacker Chemie AG
InventorsAdolph Maschberger, Peter August
Life of this patent
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Abstract
Organopolysiloxane foams are prepared by heating a mixture containing (A) a diorganopolysiloxane, (B) silicon dioxide having a surface area of at least 50 m.sup.2 /g, (C) a peroxide compound, (D) at least one organosilicon compound containing at least 2 weight percent of Si-bonded hydroxyl groups and (E) at least one organopolysiloxane having Si-bonded hydrogen, to a temperature between 280.degree. and 320.degree. C. at a pressure which does not exceed the pressure of the surrounding atmosphere.
Claims5
A process for the preparation of organopolysiloxane foams which comprises rapidly heating a mixture consisting essentially of (A) a diorganopolysiloxane having terminal groups selected from the group consisting of hydroxyl groups, hydrocarbonoxy groups and mixtures thereof and having a viscosity of at least 500,000 mPa.s at 25.degree. C., (B) a pyrogenically produced silicon dioxide having a surface area of at least 50 m.sup.2 /g, (C) a peroxide compound, (D) 2 to 20 parts by weight per 100 parts of diorganopolysiloxane (A) of an organopolysiloxane containing at least 2 and up to 9.2 weight percent of Si-bonded hydroxyl groups and (E) at least one organopolysiloxane containing Si-bonded hydrogen, to a temperature of from 280.degree. to 320.degree. C. at a pressure which does not exceed that of the surrounding atmosphere.
Dependencies are inferred from the claim text.