Thermosetting silicone composition

PROBLEM TO BE SOLVED: To provide a heat-curable silicone composition giving a cured product having high hardness/transparency and excellent heat-resistance and light resistance, and resistant to clouding even by leaving in a high-temperature and humidity state and returning to room temperature. SOLUTION: The heat-curable silicone composition is composed of (i) an organopolysiloxane expressed by formula (1): R 1 n (C 6 H 5 ) m SiO (4-n-m)/2 (R 1 is a univalent hydrocarbon group, an alkoxy group or hydroxyl group; 1≤n+m 2 a H b SiO (4-a-b)/2 (R 2 is a univalent hydrocarbon group; 0.7≤a≤2.1; 0.01≤b≤1.0; and 0.8≤a+b≤3.0), (iii) a catalyst for addition reaction, and (iv) one or more compounds selected from organohydrogenpolysiloxane having epoxy group and/or alkoxy group, organosilane having epoxy group and/or alkoxy group and non-silicon epoxy compound. COPYRIGHT: (C)2007,JPO&INPIT