CURABLE SILICONE COMPOSITION, ENCAPSULANT AND OPTICAL SEMICONDUCTOR DEVICE
A curable silicone composition is provided that is exhibits excellent wetting properties on glass substrates and that forms a cured product that has a smooth surface. The curable silicone composition comprises: (A-1) a resinous alkenyl group-containing organopolysiloxane in which aryl groups account for more than 30 mol % of all silicon atom-bonded functional groups; (A-2) a linear alkenyl group-containing organopolysiloxane in which aryl groups account for more than 30 mol % of all silicon atom-bonded functional groups; (B) a linear organopolysiloxane or a cerium-containing organopolysiloxane, in which aryl groups account for no more than 30 mol % of all silicon atom-bonded functional groups, contained in an amount of no more than 2% by mass based on the total mass of all organopolysiloxane components; (C) an organohydrogenpolysiloxane including at least 2 silicon atom-bonded hydrogen atoms per molecule, that is different from component (B); and (D) a catalyst for hydrosilylation reaction.
1 . A curable silicone composition comprising:
(A-1) a resinous alkenyl group-containing organopolysiloxane in which aryl groups account for more than 30 mol % of all silicon atom-bonded functional groups;
(A-2) a linear alkenyl group-containing organopolysiloxane in which aryl groups account for more than 30 mol % of all silicon atom-bonded functional groups;
(B) a linear organopolysiloxane or a cerium-containing organopolysiloxane, in which aryl groups account for no more than 30 mol % of all silicon atom-bonded functional groups, contained in an amount of no more than 2% by mass based on the total mass of all organopolysiloxane components;
(C) an organohydrogenpolysiloxane including at least 2 silicon atom-bonded hydrogen atoms per molecule, that is different from component (B); and
(D) a catalyst for hydrosilylation reaction.
2 . The curable silicone composition according to claim 1 , wherein the content of organopolysiloxane components (A-1) and (A-2) is 30 to 90% by mass based on the total mass of all organopolysiloxane components in the composition.
3 . The curable silicone composition according to claim 1 , wherein organopolysiloxane component (B) has a number-average molecular weight of 500 or more.
4 . The curable silicone composition according to claim 1 , wherein the content of organopolysiloxane component (B) is 1.5% by mass or less based on the total mass of all organopolysiloxane components.
5 . The curable silicone composition according to claim 1 , wherein organohydrogenpolysiloxane component (C) contains silicon atom-bonded aryl groups, and the aryl groups account for 5 to 50 mol % of all silicon atom-bonded functional groups of component (C).
6 . The curable silicone composition according to claim 1 , wherein the content of organohydrogenpolysiloxane component (C) is 5% by mass or more based on the total mass of all organopolysiloxane components.
7 . An encapsulant, comprising the curable silicone composition according to claim 1 .
8 . An optical semiconductor device, equipped with the encapsulant according to claim 7 .
9 . The curable silicone composition according to claim 2 , wherein organopolysiloxane component (B) has a number-average molecular weight of 500 or more.
10 . The curable silicone composition according to claim 2 , wherein the content of organopolysiloxane component (B) is 1.5% by mass or less based on the total mass of all organopolysiloxane components.
11 . The curable silicone composition according to claim 3 , wherein the content of organopolysiloxane component (B) is 1.5% by mass or less based on the total mass of all organopolysiloxane components.
12 . The curable silicone composition according to claim 9 , wherein the content of organopolysiloxane component (B) is 1.5% by mass or less based on the total mass of all organopolysiloxane components.
13 . The curable silicone composition according to claim 2 , wherein organohydrogenpolysiloxane component (C) contains silicon atom-bonded aryl groups, and the aryl groups account for 5 to 50 mol % of all silicon atom-bonded functional groups of component (C).
14 . The curable silicone composition according to claim 3 , wherein organohydrogenpolysiloxane component (C) contains silicon atom-bonded aryl groups, and the aryl groups account for 5 to 50 mol % of all silicon atom-bonded functional groups of component (C).
15 . The curable silicone composition according to claim 4 , wherein organohydrogenpolysiloxane component (C) contains silicon atom-bonded aryl groups, and the aryl groups account for 5 to 50 mol % of all silicon atom-bonded functional groups of component (C).
16 . The curable silicone composition according to claim 2 , wherein the content of organohydrogenpolysiloxane component (C) is 5% by mass or more based on the total mass of all organopolysiloxane components.
17 . The curable silicone composition according to claim 3 , wherein the content of organohydrogenpolysiloxane component (C) is 5% by mass or more based on the total mass of all organopolysiloxane components.
18 . The curable silicone composition according to claim 4 , wherein the content of organohydrogenpolysiloxane component (C) is 5% by mass or more based on the total mass of all organopolysiloxane components.
19 . The curable silicone composition according to claim 5 , wherein the content of organohydrogenpolysiloxane component (C) is 5% by mass or more based on the total mass of all organopolysiloxane components.