US 12,378,418 B2
Photocurable silicone composition and cured product thereof
Hyeokseong Choo, Chungcheongbuk-do (KR); and Min Hee Kwon, Chungcheongbuk-do (KR)
Assigned to DOW SILICONES CORPORATION, Midland, MI (US)
Appl. No. 17/800,342
Filed by DOW SILICONES CORPORATION, Midland, MI (US)
PCT Filed Feb. 18, 2021, PCT No. PCT/US2021/018521
§ 371(c)(1), (2) Date Aug. 17, 2022,
PCT Pub. No. WO2021/168075, PCT Pub. Date Aug. 26, 2021.
Claims priority of provisional application 62/980,357, filed on Feb. 23, 2020.
Prior Publication US 2023/0101534 A1, Mar. 30, 2023
Int. Cl. C08L 83/10 (2006.01); C08G 77/28 (2006.01); C08G 77/392 (2006.01); C08G 77/42 (2006.01); C09D 183/10 (2006.01); C09J 183/10 (2006.01)
CPC C08L 83/10 (2013.01) [C08G 77/28 (2013.01); C08G 77/392 (2013.01); C08G 77/42 (2013.01); C09D 183/10 (2013.01); C09J 183/10 (2013.01); C08L 2201/10 (2013.01)] 10 Claims
 
1. A photocurable silicone composition comprising:
(A) an organopolysiloxane represented by the following average composition formula:
R1aR2bSiO(4-a-b)/2
wherein, R1 is a C2-12 alkenyl group; R2 is a C1-12 alkyl group, a C6-12 aryl group, or a C7-12 aralkyl group; provided that at least one R2 in a molecule is the aryl group or the aralkyl group; and “a” and “b” are positive numbers satisfying: 1≤a+b≤2.5 and 0.001≤a/(a+b)≤0.2;
(B) a polysiloxane block copolymer comprising:
(i) a polysiloxane block represented by the general formula: (R32SiO)n, wherein each R3 is independently a C1-12 alkyl group, a C6-12 aryl group, or a C7-12 aralkyl group; and “n” is a positive number of at least about 5; and
(ii) an organo block containing at least three sulfur atoms and free of silicon atom in a chemical structure thereof,
wherein the polysiloxane block (i) is bonded to the organo block (ii) via a linkage represented by the general formula: (Si)-R4-(S), wherein Si is an atom in a chemical structure of the polysiloxane block (i); S is an atom in a chemical structure of the organo block (ii); and R4 is a C2-6 alkylene group, and
wherein the polysiloxane block copolymer has at least two thiol (HS-) groups in a molecule, in an amount such that the thiol groups in component (B) is in a range of from 0.2 to 2.0 moles per 1 mole of the total alkenyl groups in component (A);
(C) a photoinitiator, in an amount of from 0.01 to 5 parts by mass of per 100 parts by mass of a total mass of components (A) and (B); and
(D) an inorganic filler, in an amount of from about 0.01 to about 40 parts by mass per 100 parts by mass of a total mass of components (A) and (B).