US 6,444,154 B1 · Continuous preparation of a liquid silicone rubber composition

Abstract

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

Claims24

Dependent claims

A process of preparing a liquid silicone rubber composition, comprising:

introducing a filler, treating agent and silicone polymer into an extruder having a length to diameter ratio of at least greater than 50;
and
continuously compounding and devolatilizing said filler, treating agent and silicone polymer into said liquid silicone rubber composition in said extruder;
wherein said silicone polymer comprises a vinyl-terminated polydimethylsiloxane represented by recurring units of the following Formula:
wherein, R1 independently at each occurrence represents C1-4 alkyl, or C2-4 alkylene;
R2 independently at each occurrence represents C1-4 alkyl, C1-C4 haloalkyl or C2-4 alkylene;
R3 independently at each occurrence represents H, C1-10 alkyl, C2-4 alkylene, C4-6 cycloalkyl, OH or C1-C4 haloalkyl;
and n is a value of about 100 to less than 1000.

5 more elements

Dependencies are inferred from the claim text.

Continuous preparation of a liquid silicone rubber composition

Life of this patent

Continuous preparation of a liquid silicone rubber composition

Life of this patent

Abstract

Claims24