US 12,122,880 B2
Curable organopolysiloxane composition, cured product thereof, and transducer and the like equipped with said cured product
Hiroshi Fukui, Ichihara (JP); and Kyoko Toyama, Ichihara (JP)
Assigned to Dow Toray Co., Ltd., Tokyo (JP)
Appl. No. 17/298,081
Filed by Dow Toray Co., Ltd., Tokyo (JP)
PCT Filed Dec. 3, 2019, PCT No. PCT/JP2019/047211
§ 371(c)(1), (2) Date May 28, 2021,
PCT Pub. No. WO2020/116440, PCT Pub. Date Jun. 11, 2020.
Claims priority of application No. 2018-229640 (JP), filed on Dec. 7, 2018.
Prior Publication US 2022/0017701 A1, Jan. 20, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. C08L 83/04 (2006.01); C08G 77/08 (2006.01); C08G 77/12 (2006.01); C08G 77/20 (2006.01); C08K 3/36 (2006.01); C08K 9/06 (2006.01)
CPC C08G 77/20 (2013.01) [C08G 77/08 (2013.01); C08G 77/12 (2013.01); C08K 3/36 (2013.01); C08K 9/06 (2013.01); C08L 83/04 (2013.01); C08L 2203/20 (2013.01)] 16 Claims
 
1. A curable organopolysiloxane composition, the composition comprising:
(A1) a straight chain or branched organopolysiloxane having an alkenyl group only at an end of a molecular chain and a degree of siloxane polymerization within a range of 50 to 550;
(A2) a straight chain or branched organopolysiloxane having an alkenyl group only at an end of a molecular chain and a degree of siloxane polymerization within a range of 600 to 1000;
(B) hydrophobically treated reinforcing silica;
(C) optionally, an organopolysiloxane resin containing an alkenyl group having at least one branched siloxane unit in a molecule with an amount of vinyl (CH2═CH—) groups within a range of 1.0 to 5.0 mass %;
(D) an organohydrogenpolysiloxane having at least three silicon atom-bonded hydrogen atoms in a molecule; and
(E) an effective amount of a hydrosilylation reaction catalyst;
wherein:
the mass ratio of component (A1) to component (A2) ((A1)/(A2)) is within a range of 0.45 to 1.30,
the sum of the components (B) and (C) is within a range of 10 to 25 mass % of the entire composition,
the mass ratio of component (C) to the sum of components (B) and (C) ((C)/{(B)+(C)}) is within a range of 0 to 0.2, and
the sum of silicon atom-bonded hydrogen atoms in component (B) is an amount of from 0.1 to 2.5 mol with respect to the total amount of 1 mol of an alkenyl group in the composition.