Silicone rubber composition and manufacturing method thereof

A method for preparing a silicone rubber composition, comprising the steps of:

• heating a first mixture, which comprises 100 parts by weight of a polydimethylvinylsiloxane represented by the following formula 1, about 5 parts by weight to about 100 parts by weight of a silica filler, and about 0.1 parts by weight to about 15 parts by weight of a polymethylvinylsiloxane oil containing about 1 mole % to about 20 mole % of a vinyl group, at a temperature between about 120° C. and about 180° C.;
• depressurizing the heated first mixture to about 0.5 bar to about 0.9 bar;
• adding, to the first mixture, about 0.1 parts by weight to about 5 parts by weight of a hydrogen-modified polyorganosiloxane containing about 1 mole % to about 20 mole % of a vinyl group and about 0.05 mole % to about 20 mole % of hydrogen, about 0.0001 parts by weight to about 3 parts by weight of a platinum-based catalyst, and about 0.1 parts by weight to about 5 parts by weight of a polymethylhydrogensiloxane vulcanizing agent, followed by mixing at a temperature between about 50° C. and about 70° C. to prepare a second mixture;
• and
• subjecting the second mixture to molding and first curing to prepare a first cured product:
• (wherein R1 to R8 are each independently selected from among linear or branched C1-C10 alkyl group, C1 to C10 aminoalkyl group, C1 to C10 hydroxyalkyl group, C1 to C20 haloalkyl group, C3 to C15 cycloalkyl group, C6 to C12 aryl group, C7 to C20 aralkyl group and C2 to C20 alkenyl group;
• a, b and c are each an integer ranging from 1 to 100;
• and at least one of R1 and R8 is a vinyl group.)