| abstract |
An addition hardening type silicone rubber composition containing (A) with the following average composition formula (1)nn n n R 1 a SiO (4-a)/2 (1)n n n (In the formula, R 1 are mutually the same or different monovalent hydrocarbon groups, and a is a positive number from 1.5 to 2.8)n n n It means that an organopolysiloxane containing at least 2 alkenyl groups bonded to silicon atoms in one molecule: 100 parts by mass, (B) contains at least 2 hydrogen atoms bonded to silicon atoms in one molecule (SiH Functional group) organohydrogen polysiloxane: 0.3 to 20 parts by mass, (C) reinforcing silica: 5 to 80 parts by mass, (D) addition reaction catalyst: a platinum group metal, relative to (A) ), the total mass of (B) components is 0.5 to 1,000 ppmnn n n (E) The content of the organopolysiloxane having a degree of polymerization of 10 or less and containing one or more Si-OH functional groups in one molecule is 0.005 to 0.3% by mass relative to the entire composition. |