Patent ID: 8748533

Claim:
A curable organopolysiloxane composition comprising: (A) an organopolysiloxane having at least two silicon-bonded alkenyl groups and having an average unit formula (I): (R 1 2 SiO 2/2 ) a (R 2 3 SiO 1/2 ) b (R 3 SiO 3/2 ) c (SiO 4/2 ) d (CH 2 CH 2 ) e (I); wherein R 1 , R 2 and R 3 are independently a substituted or unsubstituted mono-valent hydrocarbon group, each of R 1 is the same with or different from each other, each of R 2 is the same with or different from each other, and a>0, b>0, c≧0, d≧0, and e>0, wherein c+d>0; (B) a branched organopolysiloxane having at least one silicon-bonded alkenyl group and having a siloxane unit of formula R 4 SiO 3/2 wherein R 4 is a substituted or unsubstituted mono-valent hydrocarbon group, and wherein the amount of component (B) is about 1 part by weight to about 9900 parts by weight, based on 100 parts by weight of component (A); (C) an organopolysiloxane having an average unit formula (II) being capped with H: (R 5 2 SiO 2/2 ) f (R 6 3 SiO 1/2 ) g (R 7 SiO 3/2 ) h (SiO 4/2 ) i (CH 2 CH 2 ) j (II): wherein R 5 , R 6 and R 7 are independently H or a substituted or unsubstituted mono-valent hydrocarbon group, wherein each of R 5 is the same with or different from each other, each of R 6 is the same with or different from each other, f>0, g>0, h≧0, i≧0, j≧0, and the amount of component (C) is about 1 parts by weight to about 300 parts by weight, based on 100 parts by weight of the total amount of components (A) and (B); and (D) a catalyst.