US 12,371,567 B2
Thermosetting silicone composition
Yutaka Oka, Chiba (JP)
Assigned to DuPont Toray Specialty Materials Kabushiki Kaisha, Tokyo (JP)
Filed by DuPont Toray Specialty Materials Kabushiki Kaisha, Tokyo (JP)
Filed on Jul. 29, 2021, as Appl. No. 17/388,406.
Claims priority of application No. 2020-147454 (JP), filed on Sep. 2, 2020.
Prior Publication US 2022/0064445 A1, Mar. 3, 2022
Int. Cl. C08L 83/04 (2006.01); C08G 77/08 (2006.01); C08G 77/12 (2006.01); C08G 77/20 (2006.01)
CPC C08L 83/04 (2013.01) [C08G 77/08 (2013.01); C08G 77/12 (2013.01); C08G 77/20 (2013.01); C08L 2203/20 (2013.01); C08L 2205/025 (2013.01); C08L 2205/03 (2013.01)] 20 Claims
 
1. A thermosetting transparent silicone composition comprising:
(A) a linear organopolysiloxane capped at both ends of the molecular chain with alkenyl groups, which is represented by the structural formula:
R1R22SiO(R22SiO)nSiR1R22 (in the formula, R1 is an alkenyl group, R2 are each independently C1-12 alkyl groups, and n is an integer of from 5 to 1500),
(B) a resinous organopolysiloxane having at least two alkenyl groups at the end of the molecular chain, wherein the amount of alkenyl groups in the entire silicon atom-bonded functional group of component (B) is 6 mol % or more with respect to the total amount of the silicon atom-bonded functional group,
(C) an organohydrogenpolysiloxane having at least two silicon atom-bonded hydrogen atoms at the side chain of the molecular chain, which is represented by the structural formula:
R43SiO(R52SiO)mSiR43 (in the formula, R4 are each independently C1-12 alkyl groups, R5 are each independently C1-12 alkyl groups or hydrogen atoms, while at least two R5 are hydrogen atoms, and m is an integer of from 3 to 200),
(D) a curing reaction catalyst; and
(E) a silicone compound functionalized with an epoxy group or an alkoxy group;
wherein component (A) is included in the amount of 60 mass % or more based on the total mass of all the organopolysiloxane component,
wherein the content of organohydrogenpolysiloxane of component (C) is 1.0 to 3.0 mols of silicon atom-bonded hydrogen atoms per 1 mol of silicon atom-bonded alkenyl groups in the composition, and
wherein the composition further comprises methyl-tris(3-methyl-1-butyn-3-oxy)silane as a reaction inhibitor.