Continuous preparation of a liquid silicone rubber composition

摘要

A continuous process provides a devolatilized liquid injection moldable silicone composition. In the process, a filler, treating agent (16) and silicone polymer are introduced into an extruder (22) having a length to diameter ratio of at least greater than 50. The filler, treating agent (16) and silicone elastomer are continuously compounded in the extruder (22) into a devolatilized liquid injection moldable silicone composition. A system (40) for preparing a liquid silicone rubber composition comprises a mixer (18) to prepare a concentrate (20) of filler and silicone polymer, a long extruder (22) having an L/D ratio of greater than 50, connected to the mixer (18) to receive the concentrate (20) from the mixer (18) and to compound and devolatilize the concentrate (20), a treating agent (16) and silicone polymer into a liquid silicone rubber composition containing volatiles and a cooler to receive the liquid silicone rubber composition to cool, homogenize and further devolatilized the composition.