US 12,247,125 B2
Curable silicone composition, encapsulant and optical semiconductor device
Sawako Horie, Chiba (JP); Shunya Takeuchi, Chiba (JP); Akihiko Kobayashi, Chiba (JP); Misoon Jung, Gyeonggi-do (KR); and Hyunji Kang, Gyeonggi-do (KR)
Assigned to DuPont Toray Specialty Materials Kabushiki Kaisha, Tokyo (JP); and DuPont Specialty Materials Korea Ltd., Chungcheongnam-Do (KR)
Filed by DuPont Toray Specialty Materials Kabushiki Kaisha, Tokyo (JP); and Rohm and Haas Electronic Materials Korea Ltd., Chungcheongnam-do (KR)
Filed on Jun. 29, 2021, as Appl. No. 17/361,788.
Claims priority of application No. 2020-123588 (JP), filed on Jul. 20, 2020.
Prior Publication US 2022/0017746 A1, Jan. 20, 2022
Int. Cl. C08L 83/04 (2006.01)
CPC C08L 83/04 (2013.01) [C08L 2205/025 (2013.01); C08L 2205/035 (2013.01)] 11 Claims
 
1. A curable silicone composition which forms a cured product of having a type D durometer hardness of 30 or more at 25° C. and having a light transmittance of 95% or more at wavelengths ranging from 400 nm to 700 nm, said curable silicone composition comprising:
(A) a resinous alkenyl group-containing organopolysiloxane including at least two alkenyl groups per molecule and at least one (SiO4/2) unit, wherein said resinous alkenyl group-containing organopolysiloxane (A) is present in an amount of 4 mass % or more based on a total mass of organopolysiloxane components in said curable silicone composition and which is represented by the following average unit formula (II):
(R13SiO1/2)a(SiO4/2)d(XO1/2)e  (II),
wherein each R1 are the same or different C1-6 alkyl groups or C2-6 alkenyl groups and where at least two R1 in one molecule are alkenyl groups, wherein X is a hydrogen atom or an alkyl group, and wherein 0.2≤a<1, 0<d<0.8, 0≤e<0.4, and a+d=1.0 are satisfied,
(B) a resinous organohydrogenpolysiloxane including at least two silicon atom-bonded hydrogen atoms per molecule and at least one (SiO4/2) unit, wherein said resinous organohydrogenpolysiloxane (B) is present in an amount of 2 mass % or more based on the total mass of organopolysiloxane components in said curable silicone composition and which is represented by the following average unit formula (IV):
(R23SiO1/2)a(SiO4/2)d(XO1/2)e  (IV),
wherein each R2 are the same or different and comprise a hydrogen atom or a C1-6 alkyl group and where at least two R2 in one molecule are hydrogen atoms, wherein X is a hydrogen atom or an alkyl group, and wherein 0.2≤a<1, 0≤d≤0.8, 0≤e<0.4, and a+d=1.0 are satisfied,
wherein the viscosity of component (B) is within the range of from 1 mPa to 500 mPa at 25° C.,
(C) a catalyst for hydrosilylation reaction,
(D) a curing reaction inhibitor,
(E) (E-1) a linear alkenyl group-containing organopolysiloxane having at least one aryl group in one molecule, wherein an aryl group content in said linear alkenyl group-containing organopolysiloxane (E-1) is 10 mol % or more of a total content of silicon atom-bonded organic groups in said curable silicone composition and (E-2) a resinous alkenyl group-containing organopolysiloxane free from siloxane units represented by (SiO4/2) and having at least one aryl group in one molecule, wherein said resinous alkenyl group-containing organopolysiloxane (E-2) is present in at an amount of 30 mass % or more based on the total mass of organopolysiloxane components in said curable silicone composition, wherein an aryl group content in said resinous alkenyl group-containing organopolysiloxane (E-2) is 3 mol % or more of a total content of silicon atom-bonded organic groups in said curable silicone composition, and
(F) a linear organohydrogenpolysiloxane having at least one aryl group in one molecule, wherein an aryl group content in said linear organohydrogenpolysiloxane (F) is 10 mol % or more of a total content of silicon atom-bonded organic groups in said linear organohydrogenpolysiloxane in said curable silicone composition.