Organopolysiloxane composition suited to automobile oil seals

摘要

A organopolysiloxane composition suited to automobile oil seals is provided, which includes (A) a diorganopolysiloxane having a viscosity at 25 DEG C. of 25 to 1,000,000 cSt blocked with a hydroxyl group at both ends of its molecular chain; (B) an iminoxysilane having the formula (1): (R1)4-nSi[-O-N=C(R1)2]n(1)wherein R1 are an unsubstituted or substituted monovalent saturated hydrocarbon group, and n is 3 or 4; (C) an amino group-containing hydrolyzable silane having the formula (2): H2N-R2-NH-R2-Si(-O-R3)3(2)wherein R2 are an unsubstituted or substituted divalent saturated hydrocarbon group having 1 to 4 carbon atoms, and R3 are a monovalent saturated hydrocarbon group having 1 to 4 carbon atoms; and (D) a curing catalyst. The composition is able to maintain a low foamability even when dispersed or dissolved in automobile oils, and is cured to provide an automobile oil seal.