| abstract |
Described herein is a platinum curing organosiloxane composition having improved hysteresis characteristics when cured. The composition requires the presence of a diorganovinylsiloxy terminated polydiorganosiloxane having a viscosity within a range of 20 to 200 Pa·s at 25°C. and containing essentially no ethylenically unsaturated hydrocarbon radicals bonded to non-terminal silicon atoms and a diorganovinylsiloxy terminated polydiorganosiloxane having a viscosity within a range of 0.1 to 200 Pa·s at 25°C., where from 1 to 5 percent of the non-terminal repeating units of the siloxane comprise a vinyl radical. In addition, the present composition comprises 10 to 30 weight percent of a reinforcing silica filler that has been treated with hexamethyldisilazane and 1,1,3,3-tetramethyl-1,3-divinyldisilazane and an organohydrogen siloxane crosslinker comprising at least ten silicon-bonded hydrogen atoms per molecule. |