Curable silicone composition, cured product thereof, and optical semiconductor device

摘要

A curable silicone composition comprising: (A) (A1) 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 (A1) and (A2) 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.

主权项

1. A curable silicone composition comprising:
(A) 100 parts by mass of a mixture of (A1) an organopolysiloxane having at least two alkenyl groups in a molecule, and free of silicon-bonded hydroxyl groups and silicon-bonded hydrogen atoms and (A2) a branched chain organopolysiloxane represented by the following average unit formula:
(R12R2SiO1/2)a(R13SiO1/2)b(SiO4/2)c(HO1/2)d  wherein R1 are the same or different alkyl groups having from 1 to 10 carbons; R2 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:
R3R4Si(OR5)2  wherein R3 is a glycidoxyalkyl group, an epoxycyclohexylalkyl group, an epoxyalkyl group, an acryloxyalkyl group, or a methacryloxyalkyl group; R4 is an alkyl group having from 1 to 6 carbons; and R5 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.