SEALING AGENT FOR OPTICAL SEMICONDUCTOR DEVICES, AND OPTICAL SEMICONDUCTOR DEVICE

摘要

Provided is a sealing agent for optical semiconductor devices, which is capable of suppressing surface tackiness of a cured product thereof and is also capable of improving the heat resistance and temperature cycle characteristics of the cured product. A sealing agent for optical semiconductor devices of the present invention contains: a first organopolysiloxane which is represented by formula (1A) or formula (1B) and has an alkenyl group and a methyl group that is bonded to a silicon atom; a second organopolysiloxane which is represented by formula (51A) or formula (51B) and has a hydrogen atom that is bonded to a silicon atom and a methyl group that is bonded to a silicon atom; and a catalyst for hydrosilylation reactions. The content ratios of the methyl groups bonded to silicon atoms in the first and second organopolysiloxanes are respectively 80% by mole or more. (R1R2R3SiO1/2)a(R4R5SiO2/2)b(R6SiO3/2)c Formula (1A) (R1R2R3SiO1/2)a(R4R5SiO1/2)b(R6SiO3/2)c Formula (1B) (R51R52R53SiO1/2)p(R54R55SiO2/2)q(R56SiO3/2)r Formula (51A) (R51R52R53SiO1/2)p(R54R55SiO2/2)q(R56SiO3/2)r Formula (51B)