| 摘要 |
PURPOSE:To maintain transparency of silicone rubber for a long time and to prevent deterioration of the transparency at high temp. effectively by constructing a core of additive reaction type silicone rubber and incorporating a specified pts.wt. crosslinking catalyst into the silicon rubber. CONSTITUTION:A cylindrical clad 2 having lower refractive index than that of a core 1 is adhered to the periphery of a transparent core 1 consisting of silicone rubber having high refractive index. The content of a crosslinking catalyst in the silicone rubber is selected to 0.005X10<-4>-0.1X10<-4>pts.wt., pref. 0.01X10<-4>-0.05X10<-4>pts.wt. as Pt basing on 100pts.wt. base polymer. The addition reaction type silicone rubber consists of a base polymer comprising diorgano polysiloxane contg. vinyl groups, a crosslinking agent comprising organo hydrogen polysiloxane contg. Si-H groups, and Pt compd. as a catalyst for crosslinking the above described base polymer to the crosslinking agent. |
