Heat-vulcanizable silicone compositions from premix

Abstract

A continuous process of preparing a heat-vulcanizable filled silicone composition, comprises mixing filler and high viscosity silicone polymer continuously in a first co-rotating intermeshing twin screw extruder; and compounding a filler and silicone polymer mixture from the first extruder in a second single shaft reciprocating extruder. Another continuous process of preparing a heat-vulcanizable filled silicone composition, comprises forming a premix′ of filler and high viscosity silicone polymer; mixing the premix and additional high viscosity silicone polymer continuously in a co-rotating intermeshing twin screw extruder; and compounding a filler and silicone polymer mixture from the co-rotating intermeshing twin screw extruder in a second single shaft reciprocating extruder.

Dependencies are inferred from the claim text.