| 摘要 |
PROBLEM TO BE SOLVED: To improve mold releasability and flow characteristics in a mold without impairing characteristics of a silicone rubber by using an organopolysiloxane, a reinforceable silica and a hardening agent as indispensable components, and blending an ester wax with a silicone rubber composition molded in the mold. SOLUTION: A mean composition formula of an organopolysiloxane is represented by R<1> a SiO(1-a)/2 wherein R<1> is an alkyl group such as a methyl group, ethyl group, propyl group, butyl group or the like, and a is a positive number of 1.90 to 2.05. A reinforceable silica which has at least 50 m<2> /g or more of a specific surface area is preferable or particularly 100 to 400 m<2> /g is preferable. As an ester wax, the wax which has a melting point of 40 to 150 deg.C or particularly 40 to 100 deg.C at an ordinary pressure is preferable. If the melting point is less than 40 deg.C, a mold releasability at the time of heating sometimes become insufficient, while if it exceeds 150 deg.C, dispersibility in the rubber compound might be lowered. |
