Patent ID: 7754799
Filing Date: 2010-07-13
Classification: C08G,C08K,C08L,Y10T

Abstract:
1. An organopolysiloxane composition for magnesium alloy bonding, having improved chemical resistance, said composition comprising (A) 100 parts by weight of an organopolysiloxane having the general formula (1): wherein R is each independently a substituted or unsubstituted monovalent hydrocarbon radical of 1 to 10 carbon atoms, X is an oxygen atom or an alkylene radical of 2 to 5 carbon atoms, Me is methyl, n is an integer of at least 10, and m is each independently 0 or 1, or an organopolysiloxane having the general formula (2): wherein R, Me, X and m are as defined above, p is an integer of at least 10, q is an integer of 1 to 5, and R 1 is a branching chain containing hydrolyzable radicals of the formula (3): wherein R, Me, X and m are as defined above, or a mixture thereof, (B) 1 to 50 parts by weight of a non-reactive silicone oil, (C) 20 to 100 parts by weight of zinc oxide which is surface treated with a silane or siloxane treating agent, (D) 20 to 100 parts by weight of heavy calcium carbonate which is surface treated with a paraffin treating agent, (E) 0.1 to 30 parts by weight of an organosilicon compound having at least three hydrolyzable radicals each bonded to a silicon atom in the molecule or a partial hydrolyzate thereof, (F) 0.1 to 10 parts by weight of a silane coupling agent having at least one epoxy radical in the molecule, and (G) an effective amount of a titanium chelate catalyst, wherein components (C) and (D) are present in a weight ratio C/D between 0.5 and 1.5.