Patent ID: 8614282

Claim:
A low gas permeable silicone resin composition comprising (A) 20 to 95 parts by weight of an organopolysiloxane containing at least two alkenyl groups in a molecule, having the average compositional formula (1): (R 1 SiO 3/2 ) a (R 2 2 SiO) b (R 1 R 2 R 3 SiO 1/2 ) c (1) wherein R 1 is each independently C 6 -C 14 aryl, R 2 which may be the same as or different from R 1 is each independently a substituted or unsubstituted, monovalent hydrocarbon group, R 3 is C 2 -C 8 alkenyl, a is a positive number of 0.3 to 0.9, b is a positive number of 0 to 0.5, c is a positive number of 0.05 to 0.7, and a+b+c=1.0, (B) 0.01 to 40 parts by weight of an organohydrogenpolysiloxane containing at least two silicon-bonded hydrogen atoms in a molecule, having the average compositional formula (2): R 1 d R 2 e H f SiO (4-d-e-f)/2 (2) wherein R 1 and R 2 are as defined above, d is a positive number of 0.6 to 1.5, e is a positive number of 0 to 0.5, f is a positive number of 0.4 to 1.0, and d+e+f=1.0 to 2.5, and (C) a catalytic amount of an addition reaction catalyst.