Curable silicone composition, cured product thereof, and optical semiconductor device
View Patent ↗A curable silicone composition comprising: (A) (A 1 ) an organopolysiloxane having at least two alkenyl groups in a molecule and free of silicon-bonded hydroxyl groups or silicon-bonded hydrogen atoms, or a mixture of said component (A 1 ) and (A 2 ) a branched chain organopolysiloxane represented by an average unit formula; (B) an organopolysiloxane having at least two silicon-bonded hydrogen atoms in a molecule; (C) a diorganodialkoxysilane represented by a general formula; (D) a straight chain organosiloxane oligomer having at least one silicon-bonded hydroxyl group in a molecule and free of silicon-bonded hydrogen atoms; and (E) a hydrosilylation catalyst, can form a cured product which exhibits excellent initial adhesive properties and transparency and exhibits excellent adhesive durability and retention of transparency under conditions of high temperature and high humidity.
1. A curable silicone composition comprising:
(A) 100 parts by mass of a mixture of (A 1 ) an organopolysiloxane having at least two alkenyl groups in a molecule, and free of silicon-bonded hydroxyl groups and silicon-bonded hydrogen atoms and (A 2 ) a branched chain organopolysiloxane represented by the following average unit formula:
(R 1 2 R 2 SiO 1/2 ) a (R 1 3 SiO 1/2 ) b (SiO 4/2 ) c (HO 1/2 ) d
wherein R 1 are the same or different alkyl groups having from 1 to 10 carbons; R 2 is an alkenyl group; and “a”, “b”, “c” and “d” are all positive numbers that satisfy the following conditions: a+b+c=1; a/(a+b)=0.15 to 0.35; c/(a+b+c)=0.53 to 0.62; and d/(a+b+c)=0.005 to 0.03;
(B) an organopolysiloxane having at least two silicon-bonded hydrogen atoms in a molecule, in an amount that provides from 0.1 to 10 moles of silicon-bonded hydrogen atoms in this component per 1 mole of the alkenyl groups in component (A);
(C) from 0.01 to 10 parts by mass of a diorganodialkoxysilane represented by the following general formula:
R 3 R 4 Si(OR 5 ) 2
wherein R 3 is a glycidoxyalkyl group, an epoxycyclohexylalkyl group, an epoxyalkyl group, an acryloxyalkyl group, or a methacryloxyalkyl group; R 4 is an alkyl group having from 1 to 6 carbons; and R 5 is an alkyl group having from 1 to 4 carbons;
(D) from 0.01 to 10 parts by mass of a straight chain organosiloxane oligomer having at least one silicon-bonded hydroxyl group in a molecule and free of silicon-bonded hydrogen atoms; and
(E) a catalytic amount of a hydrosilylation catalyst.
2. The curable silicone composition according to claim 1 , wherein a content of component (A 2 ) in component (A) is 60 mass % or less.
3. The curable silicone composition according to claim 1 , which is a sealing agent or adhesive for an optical semiconductor element.
4. A cured product obtained by curing the curable silicone composition of claim 1 .
5. An optical semiconductor device comprising: an optical semiconductor element; and a cured product of the curable silicone composition of claim 1 , which seals or bonds the optical semiconductor element.
6. The optical semiconductor device according to claim 5 , wherein the optical semiconductor element is a light emitting diode.
7. The curable silicone composition according to claim 1 , wherein component (A 1 ) is a dimethylpolysiloxane capped at both molecular terminals with dimethylvinylsiloxy groups.
8. The curable silicone composition according to claim 2 , wherein the following conditions are satisfied: a/(a+b)=0.2 to 0.3; c/(a+b+c)=0.55 to 0.60; and d/(a+b+c)=0.01 to 0.025.
9. The curable silicone composition according to claim 1 , wherein the following conditions are satisfied: a/(a+b)=0.2 to 0.3; c/(a+b+c)=0.55 to 0.60; and d/(a+b+c)=0.01 to 0.025.