| 摘要 |
PROBLEM TO BE SOLVED: To provide a curable silicone composition having excellent handleability and high reactivity and forming a low gas-permeable cured product, the low gas-permeable cured product, and an optical semiconductor device excellent in reliability.SOLUTION: A curable silicone composition comprises at least (A) an organopolysiloxane represented by an average unit formula and having at least two alkenyl groups in one molecule, optionally, (B) a linear organopolysiloxane having at least two alkenyl groups in one molecule and not having a silicon atom-bound hydrogen atom, (C) an organopolysiloxane having at least two silicon atom-bound hydrogen atoms in one molecule and at least 80 mass% of organotrisiloxanes represented by a formula, H(CH)SiO(CH)SiOSi(CH)H in the component, and (D) a catalyst for hydrosilylation reaction. |
