HYDROSILYLATION-CURABLE SILICONE RUBBER COMPOSITION

摘要

Provided is a silicone rubber composition having good transparency and hardness. The present invention is a hydrosilylation-curable silicone rubber composition containing (A) 100 parts by mass of an organopolysiloxane, (B) a silicone resin, (C) an organohydrogenpolysiloxane, (D) a rare earth salt of a carboxylic acid represented by general formula (I): (RCOO)nM (I) (in the formula, R denotes a monovalent hydrocarbon group having 4 to 10 carbon atoms, n denotes a number between 3 and 4, and M denotes a rare earth element selected from among cerium (Ce), lanthanum (La), neodymium (Nd), praseodymium (Pr), samarium (Sm) and the like), and (E) a hydrosilylation reaction catalyst.

主权项

1. A hydrosilylation-curable silicone rubber composition comprising:
(A) 100 parts by mass of an organopolysiloxane having an average degree of polymerization of 50 to 10000 and containing at least two alkenyl groups bonded to a silicon atom in one molecule; (B) 10 to 400 parts by mass of a silicone resin which includes units selected from R1SiO1/2 unit (unit M), SiO4/2 unit (unit Q), R2SiO2/2 unit (unit D), and R3SiO3/2 unit (unit T) and in which a sum of the unit M, unit Q and unit T in the whole structural units is 80% by mole or more, wherein R1, R2 and R3 are a monovalent hydrocarbon group having 1 to 6 carbon atoms, and at least two in one molecule are alkenyl groups; (C) an organohydrogenpolysiloxane containing at least two hydrogen atoms bonded to a silicon atom in one molecule, in an amount in which the number of the hydrogen atoms bonded to a silicon atom per one alkenyl group bonded to a silicon atom in the component (A) and the component (B) is 1.0 to 10.0; (D) a rare-earth salt of a carboxylic acid represented by the formula (I) or a mixture thereof:
(RCOO)nM  (I)wherein R is a monovalent hydrocarbon group having 4 to 10 carbon atoms, n is a number of 3 to 4, and M is a rare-earth element selected from cerium (Ce), lanthanum (La), neodymium (Nd), praseodymium (Pr), and samarium (Sm; and
(E) a hydrosilylation reaction catalyst.