SILICONE RUBBER COMPOSITION FOR SEALING ELECTRIC/ELECTRONIC PART

PROBLEM TO BE SOLVED: To provide a silicone rubber composition for sealing electric/electronic parts, excellent in reliability, and giving a cured material having a uniform film thickness on using the same as a sealing material of the electric/electronic parts. SOLUTION: This silicone rubber composition for sealing the electric/electronic parts, containing (A) a base polymer, (B) a cross-linking agent and (C) a platinum-based catalyst is provided by using, as the component (A), an alkenyl group-containing polyorganosiloxane having ≥1.02 relative viscosity ratio (viscosity B/viscosity A) and (D) a filler. Provided that the viscosity A is the viscosity measured at 23°C by mixing 100 pts.wt. component (A) with 1 pt.wt. condensation catalyst and 3 pts.wt. alkoxy group-containing silane, and the viscosity B is the viscosity of the above mixed liquid at 23°C after further standing the mixture still for 30 min at a room temperature. The composition containing the (A) component shows 28-45 mm diameter at 10 min after 1 cc of the composition is dripped on a flat plate. COPYRIGHT: (C)2007,JPO&INPIT