Patent ID: 8178642

Claim:
A curable organopolysiloxane composition comprising: (A) a solvent-soluble organopolysiloxane obtained by conducting a hydrosilylation reaction between (i) an organopolysiloxane that contains in one molecule at least two alkenyl groups and is represented by the following average structural formula: R 1 a SiO (4-a)/2 (wherein R 1 represents a substituted or unsubstituted monovalent hydrocarbon group, the content of alkenyl groups in all groups represented by R 1 is within the range of 0.1 to 40 mole %, and “a” is a positive number that satisfies the following condition: 1≦a<2), and (ii) a diorganopolysiloxane represented by the following general formula: HR 2 2 SiO(R 2 2 SiO) n R 2 2 SiH (wherein R 2 designates substituted or unsubstituted monovalent hydrocarbon groups that can be identical or different and that are free of unsaturated aliphatic bonds, and “n” is an integer ranging from 0 to 1,000) {constituent (ii) is used in such an amount that the content of silicon-bonded hydrogen atoms of this constituent is less than 1 mole per 1 mole of alkenyl groups of constituent (i)}, the reaction being carried out in the presence of (iii) a hydrosilylation catalyst; (B) an organohydrogenpolysiloxane represented by the following average structural formula: R 2 b H c SiO (4-b-c )/2 (wherein R 2 is the same as defined above, and “b” and “c” are positive numbers that satisfy the following conditions: 0.7≦b≦2.1; 0.001≦c≦1.0; and 0.8≦(b+c)≦2.6); {component (B) is used in such an amount that the content of silicon-bonded hydrogen atoms of this component is in the range of 0.1 to 10 moles per 1 mole of alkenyl groups of component (A)}; and (C) a hydrosilylation catalyst used in a catalytic amount.