Patent ID: 11879060
Assignee: DOW SILICONES CORPORATION
Field: Macromolecular chemistry, polymers (Chemistry)
Classification: CPC C  H | IPC C  H

Claim 0:
1. A curable silicone composition comprising:
(A) 100 parts by mass of a linear organopolysiloxane having at least two alkenyl groups and at least one aryl group in a molecule;
(B) 10 to 60 parts by mass of a branched organopolysiloxane represented by the following average unit formula:
(R13S1/2)a(R22SiO2/2)b(SiO4/2)c 
wherein, R1 are the same or different, and are alkyl groups having from 1 to 12 carbon atoms, or aryl groups having from 6 to 20 carbon atoms, with at least one R1 in a molecule being an aryl group; R2 are the same or different, and are alkyl groups having from 1 to 12 carbon atoms, alkenyl groups having from 2 to 12 carbon atoms, or aryl groups having from 6 to 20 carbon atoms; and subscripts a, b, and c are numbers that satisfy the following conditions: 0.1≤a≤0.6, 0≤b≤0.1, 0.4≤c≤0.9, and a+b+c=1;
(C) an organosiloxane having at least two silicon atom-bonded hydrogen atoms in a molecule, in an amount such that the number of silicon atom-bonded hydrogen atoms in this component is from 0.4 to 5 moles per 1 mole of total alkenyl groups in components (A) and (B), wherein the organosiloxane is:
(C1) an organosiloxane represented by the following general formula:

HR52SiO(R52SiO)nSiR52H

wherein, R5 are the same or different, and are alkyl groups having from 1 to 12 carbon atoms, or aryl groups having from 6 to 12 carbon atoms, with at least one R5 in a molecule being an aryl group; and subscript n is a number from 1 to 100;
(C2) an organopolysiloxane having at least two silicon-bonded hydrogen atoms in a molecule and represented by the following average unit formula:

(HR52SiO1/2)d(R52SiO/2)e(R5SiO3/2)f 

wherein, each R5 is independently selected and defined above, with at least one R5 in a molecule being an aryl group; and subscripts d, e, and f are numbers that satisfy the following conditions: 0.1<d≤0.7,0≤e≤0.5,0.1≤f<0.9, and d+e+f=1; or
a mixture of components (C1) and (C2); and
(D) an effective quantity of a hydrosilylation reaction catalyst.