摘要 |
A silicone rubber composition comprising an organopolysiloxane having a viscosity of at least 250,000 mPa·s at 25° C., treated filler and a curing agent is described. The composition is substantially free of reinforcing silica fillers and the filler comprises calcium carbonate treated with a treating agent having the formula: R4H3-dSiO[(R42SiO)f(R4HSiO)g]SiR4dH3-d wherein in each formula, R4 represents an optionally substituted hydrocarbon group containing 1-6 carbon atoms; H is hydrogen, d is zero or an integer from 1 to 3; and f and g are independently is zero or an integer which treating agent has at least one Si—H groups and a viscosity of from 5 to 500 mPa·s at 25° C. |