Curable composition

A curable composition, comprising:

• (A) an organopolysiloxane, which comprises an organopolysiloxane having an average composition formula of Formula 8, and which comprises an aliphatic unsaturated bond and an aryl group and of which a molar ratio (Ar/Si) of aryl groups (Ar) binding to silicon atoms with respect to a total of silicon atoms (Si) is from 0.3 to 1.1;
• (B) an organopolysiloxane, which comprises an aryl group and a hydrogen atom binding to a silicon atom and of which a molar ratio (Ar/Si) of aryl groups (Ar) binding to silicon atoms with respect to a total of silicon atoms (Si) is from 0.3 to 1.2;
• and
• (C) an inorganic particle, of which the surface is treated with an organopolysiloxane which has an average composition formula of Formula 17 and of which a molar ratio (Ar/Si) of aryl groups (Ar) binding to silicon atoms with respect to a total of silicon atoms (Si) is from 0.1 to 1.8:
• (R1R22SiO1/2)a(R3R4SiO2/2)b(R5SiO3/2)c(SiO2)d [Formula 8]
• where R1 is a monovalent hydrocarbon group having 2 or more carbon atoms, R2 is an alkyl group having 1 to 4 carbon atoms, R3 and R4 are each independently an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms or an aryl group having 6 to 25 carbon atoms, R5 is an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 25 carbon atoms, with the proviso that at least one of R1, R3 and R4 is an alkenyl group;
• a is a positive number, b is a positive number, c is a positive number, d is 0 or a positive number, b/a is 5 or more, and b/c is 5 or more,
• (R3SiO1/2)a(R2SiO2/2)b(RSiO3/2)c(SiO2)d [Formula 17]
• where R's are independently hydrogen, a hydroxyl group, an alkoxy group, an epoxy group, a (meth)acryloyl group, an isocyanate group or a monovalent hydrocarbon group, with the proviso that at least one of R's is an aryl group;
• and a, b, c and d are each independently 0 or a positive number, with the proviso that the sum thereof (a+b+c+d) is 1, and a is 0 to 0.3, b is 0 to 1, c is 0 to 0.8, and d is 0 to 0.8.