Thermosetting silicone resin composition for reflector of led, reflector for led using the same and optical semiconductor apparatus

A thermosetting silicone resin composition for a reflector of an LED comprising

• (A) 45 to 90 parts by mass of an organopolysiloxane represented by the following average compositional formula (1), and having at least two alkenyl groups in one molecule,
• R1aR2bR3c(OR0)dSiO(4-a-b-c-d)/2 (1)
• wherein R1 each independently represents a substituted or unsubstituted monovalent hydrocarbon group having neither alkenyl group nor aryl group;
• R2 represents an aryl group;
• R3 represents an alkenyl group;
• R0 represents a hydrogen atom, a methyl group or an ethyl group;
• “a” represents a number of 0.4 to 1.0;
• “b” represents a number of 0 to 0.5;
• “c” represents a number of 0.05 to 0.5;
• “d” represents a number of 0 to 0.5;
• and these numbers satisfy a+b+c+d=1.0 to 2.0,
• (B) 10 to 55 parts by mass of a linear organohydrogen polysiloxane represented by the following general formula (2) and/or a branched organohydrogenpolysiloxane represented by the following average compositional formula (3), which has at least two hydrogen atoms directly bonded to a silicon atom in one molecule, provided that the sum of Component (A) and Component (B) is 100 parts by mass,
• wherein R4 each independently represents a substi-tuted or unsubstituted monovalent hydrocarbon group having no alkenyl group;
• R5 represents hydrogen;
• and a repeating unit “n” represents an integer of 1 to 10,
• R7eR8fHgSiO(4-e-f-g)/2 (3)
• wherein R7 each independently represents a substituted or unsubstituted monovalent hydrocarbon group containing neither an alkenyl group nor an aryl group;
• R8 represents an aryl group;
• “e” represents a number of 0.6 to 1.5;
• “f” represents a number of 0 to 0.5;
• “g” represents a number of 0.4 to 1.0;
• and these numbers satisfy e+f+g=1.0 to 2.5,
• (C) a catalytic amount of an addition reaction catalyst,
• (D) 3 to 200 parts by mass of a white pigment selected from titanium oxide, zinc oxide, magnesium oxide, barium carbonate, magnesium silicate, zinc sulfate and barium sulfate, and
• (E) 100 to 1000 parts by mass of an inorganic filler other than Component (D), and
• wherein an amount of Component (B) is 70% by mass or more based on a whole hydrogen atom-containing silicon compound having at least two hydrogen atoms directly bonded to a silicon atom in one molecule contained in the thermosetting silicone resin composition.