Patent ID: 8748293

Claim:
An organopolysiloxane obtained by subjecting an alkenyl group-containing organopolysiloxane (A1) to a hydrosilylation reaction with a hydrosilyl group-containing compound (A2) in the presence of a platinum group metal-based catalyst; wherein the alkenyl group-containing organopolysiloxane (A1) is a non-aromatic saturated hydrocarbon group-containing organppolysiloxane containing the following units (I) to (III): (I) a siloxane unit (T unit) represented by R 1 SiO 3/2 : 40 to 99 mol %; (II) a siloxane unit (D unit) represented by R 2 R 3 SiO 2/2 : 59 mol % or less; and (III) a siloxane unit (M unit) represented by R 4 R 5 R 6 SiO 1/2 : 1 to 30 mol %; wherein: R 1 to R 6 represents a monovalent organic group or a hydrogen atom; 40 mol % or more of all the organic groups and hydrogen atoms represented by R 1 to R 6 are each a non-aromatic saturated hydrocarbon group having 3 to 20 carbon atoms; 30 mol % or more of all the organic groups and hydrogen atoms represented by R 1 to R 3 may be the same or different and represent non-aromatic saturated hydrocarbon groups, having one of the following cyclic structures having 5 to 7 carbon atoms: and, the remainder of all the organic groups and hydrogen atoms represented by R 1 to R 6 may be the same or different and represent hydrogen atoms or substituted or unsubstituted monovalent hydrocarbon groups, having 1 to 7 carbon atoms, and wherein 2 to 30 mol % of all the organic groups and hydrogen atoms represented by R 1 to R 6 are each an alkenyl group having 2 to 7 carbon atoms; wherein the hydrosilyl group-containing compound (A2) is represented by the following average composition formula (1): R 7 a R 8 b H c SiO (4-a-b-c)/2 (1), wherein R 7 represents a monovalent organic group other than an alkenyl group; R 8 represents a divalent organic group; and a, b, and c represent positive numbers satisfying that: 0≦a≦2.5, 0≦b≦1, 0.75≦a+b≦2.5, 0.005≦c≦1, and 0.8≦a+b+c≦4, wherein the hydrosilyl group-containing compound (A2) contains at least two SiH groups in one molecule, and wherein the hydrosilyl group-containing compound (A2) is such content that the total molar amount of the SiH groups is 0.4 to 1.0 times a total molar amount of the alkenyl groups contained in the alkenyl group-containing organopolysiloxane (A1).