A room temperature crosslinking, one component (RTV 1C) silicone rubber formulation
with hydrophobic, silica featuring extremely low water absorption, a high level
of whiteness, and fine-tunable, storage-stable rheological properties with a high
reinforcing action in the silicone rubber vulcanizate contains A) from 0.5 to 60%
by weight of a hydrophobic silica having the following properties: a carbon content
of 3.1%; a methanol wettability of 60%; a reflectance of 94%;
a BET/CTAB ratio of from 1 to 3; a DBP absorption of 230 g/100
g; a BET surface area of from 50 to 110 m2/g; a CTAB surface area of
30 m2/g; a water vapor absorption at 30 C. at an ambient
humidity of 30 of 1.3; a water vapor absorption at 30 C. at an ambient
humidity of 70 of 1.7; and B) 40-99.5% by weight of an organopolysiloxane
of the formula
wherein each R represents independently alkyl, acetoxy, oxime, alkoxy, amido,
aryl or alkenyl radicals, each having from 1 to 50 carbon atoms, each unsubstituted
or substituted identically or differently by O, S, F, Cl, Br or I; or R represents
independently polystyrene, polyvinyl acetate, polyacrylate, polymethacrylate, or
polyacrylonitrile radicals, each having 50-10 000 repeating units; wherein each
Z represents independently OH, Cl, Br, acetoxy, amino, amido, amineoxy, oxime,
alkoxy, alkenyloxy, acyloxy or phosphate radicals, wherein said acetoxy, amino,
amido, amineoxy, oxime, alkoxy, alkenyloxy and acyloxy radicals each have up to
20 carbon atoms; wherein each Z represents independently oxime, alkoxy,
amido or acetoxy radicals; wherein n is 1-3; and wherein x is 100-15 000.