US 12,104,059 B2
Curable silicone composition and cured product thereof
Stanton J. Dent, Midland, MI (US); and Randall G. Schmidt, Midland, MI (US)
Assigned to DOW SILICONES CORPORATION, Midland, MI (US)
Appl. No. 17/424,215
Filed by DOW SILICONES CORPORATION, Midland, MI (US)
PCT Filed Jan. 21, 2020, PCT No. PCT/US2020/014378
§ 371(c)(1), (2) Date Jul. 20, 2021,
PCT Pub. No. WO2020/154272, PCT Pub. Date Jul. 30, 2020.
Claims priority of provisional application 62/795,672, filed on Jan. 23, 2019.
Prior Publication US 2022/0112375 A1, Apr. 14, 2022
Int. Cl. C08L 83/04 (2006.01); C08G 77/08 (2006.01); C08G 77/12 (2006.01); C08G 77/20 (2006.01); C08G 77/24 (2006.01)
CPC C08L 83/04 (2013.01) [C08G 77/08 (2013.01); C08G 77/12 (2013.01); C08G 77/20 (2013.01); C08G 77/24 (2013.01); C08L 2201/08 (2013.01); C08L 2201/10 (2013.01); C08L 2205/025 (2013.01); C08L 2205/03 (2013.01)] 15 Claims
 
1. A curable silicone composition comprising:
(A) from about 40 to about 60 parts by mass of a silicone resin consisting essentially of R3SiO1/2 siloxane units and SiO4/2 siloxane units, wherein each R is the same or different, and independently selected from halogen-substituted or unsubstituted monovalent hydrocarbon groups free of aliphatic unsaturated bonds, and the mole ratio of R3SiO1/2 siloxane units to SiO4/2 siloxane units in the silicone resin having a value of from about 0.6 to about 1.5;
(B) from about 60 to about 40 parts by mass of an organopolysiloxane having at least two alkenyl groups per molecule and free of SiO4/2 siloxane units in the organopolysiloxane, with the proviso that the total amount of components (A) and (B) is 100 parts by mass;
(C) an organosiloxane having at least three silicon atom-bonded hydrogen atoms per molecule, in an amount of the organosiloxane being sufficient enough to provide a molar ratio of silicon atom-bonded hydrogen atoms of component (C) to the alkenyl groups in component (B) in the range of from about 1.0 to about 3.0; wherein component (C) comprises a silicone resin consisting essentially of R2HSiO1/2 siloxane units and SiO4/2 siloxane units, wherein each R is independently selected and as described above, and the mole ratio of R2HSiO1/2 siloxane units to SiO4/2 siloxane units in the silicone resin having a value of from about 1.5 to about 4.0; and
(D) a hydrosilylation catalyst in an amount sufficient to initiate curing of the composition.