Patent ID: 8907001

Claim:
A method of reinforcing a silicone elastomer, the method comprising cold mixing a precipitated silica, pretreated with at least one organosilane hydrophobing compound or one hydrophobing silicone oil, with said silicone elastomer, wherein said pretreated silica has the following properties: (a) a median particle size lower than 30 μm, (b) a BET specific surface ranging from 50 to 450 m 2 /g, (c) a water wettability lower than 80, and (d) a sulfur content lower than 0.1% by weight; and wherein the silica before treatment with at least one organosilane hydrophobing compound or one hydrophobing silicone oil presents a BET specific surface S BET , and a CTAB specific surface, S CTAB , such that their difference (S BET −S CTAB ) is greater than 25 m 2 /g.