Silicone rubber compositions containing 0.5-60 wt. hydrophobic silicic acids and pyrogen based granulate useful in silicone rubber seals for automobiles, sports, domestic, electrical and electronic equipment, and oil exuding seals

摘要

Silicone rubber compositions containing 0.5-60 wt.% hydrophobic silicic acids and a granulate based on pyrogen obtained by flame hydrolysis of an Si dioxide obtained from a volatile Si compound with the following physicochemical characteristic:mean grain size 10-120 micron, BET-surface 40-400 m2g, pH value 3.0-8.5, density (stampfdichte, sic) 220-700 g/liter, and 40-99.5 wt.% organosiloxane of given formula are new. Silicone rubber compositions containing 0.5-60 wt.% hydrophobic silicic acids and a granulate based on pyrogen obtained by flame hydrolysis of an Si dioxide obtained from a volatile Si compound with the following physicochemical characteristic:mean grain size 10-120 micron, BET-surface 40-400 m2g, ph value 3.0-8.5, density (stampfdichte, sic) 220-700 g/liter, and 40-99.5 wt.% organosiloxane of formula (I)(structure I, page 18): R = alkyl, alkoxy, aryl, oxime, acetoxy, 1-50C alkyl, optionally substituted with O, S, F, Cl, Bi, I, and/or polstyrene-, vinyl acetate-, acrylate-, or polyacrylonitrile with 40-10,000 repeating units, Z = OH, Cl, Br, acetoxy, amino, aminoxy, oxime, alkoxy-amido, alkenyloxy, acryloxy, or phosphate, and the organic residue can have up to 20 C atoms, Z' = oxime, alkoxy, acetoxy, amino, or amido, n = 1-3, X =100-15,000.