Patent ID: 7842755
Filing Date: 2010-11-30
Classification: C08G,C08L,H01L

Abstract:
1. A curable organopolysiloxane composition comprising: 100 parts by weight of (A) a mixture of (A1) a liquid organopolysiloxane of an average unit formula: R a SiO (4-a)/2 that contains in one molecule at least two unsaturated aliphatic groups and has a viscosity at 25° C. within the range of 10 to 100,000 mPa·s, wherein R designates an unsubstituted or halogen-substituted univalent hydrocarbon group with 1 to 10 carbon atoms, “a” is a positive number that satisfies the following condition: 1.9≦a≦2.2, and no less than 20 mole % of all R's in one molecule are phenyl groups, and (A2) an organopolysiloxane resin of an average unit formula: R a SiO (4-a)/2 wherein R is an unsubstituted or halogen-substituted univalent hydrocarbon group with 1 to 10 carbon atoms, “a” is a positive number that satisfies the following condition: 0.5≦a≦1.7, and no less than 20 mole % of all R's in one molecule are phenyl groups, wherein said mixture constituent (A1) is added in the amount of 99 to 30 wt. %, and said mixture constituent (A2) is added in the amount of 1 to 70 wt. %; (B) an organohydrogenpolysiloxane of an average unit formula: R 1 b H c SiO (4-b-c)/2 that contains in one molecule at least two silicon-bonded hydrogen atoms, wherein R 1 designates an unsubstituted or halogen-substituted univalent hydrocarbon group with 1 to 10 carbon atoms, “b” and “c” are positive numbers that satisfy the following conditions: 0.002<c<1; 1.0<b<2.2; and 1.0<(b+c)<3.0 wherein said component (B) is added in such an amount that the mole ratio of said silicon-bonded hydrogen atoms of said component (B) to said unsaturated aliphatic groups of said component (A) is within the range of 0.3 to 5; 0.1 to 50 parts by weight of (C) a radical copolymer copolymerized from (a) a vinyl monomer that does not contain in its molecule an epoxy group, an alkoxysilyl group, and a hydrosilyl group, (b) a vinyl monomer having in its molecule an epoxy group and/or an alkoxysilyl group but not having a hydrosilyl group, and (c) a vinyl monomer having in one molecule a hydrosilyl group, said radical copolymer being copolymerized in the presence of (d) a chain-transfer agent; and a catalytic quantity of (D) a hydrosilation catalyst.