METHOD OF BLENDING POLYOLEFINS AND POLYDIORGANOSILOXANE GUMS AND BLENDS THEREOF

摘要

Mechanically mixing 7 to 75 weight percent of a polydiorganosiloxane gum having 1.5 to 17 mol percent vinyl or allyl bearing siloxane units with 25 to 93 weight percent of a low density polyethylene, a high density polyethylene, polymethylpentene, polypropylene or a copolymer of tetrafluorethylene and ethylene at a shear rate greater than 10 sec <->1 for a period of time suitable to obtain a viscosity within 60 percent of the maximum viscosity obtainable at mixing conditions where the temperature is from 175 DEG to 300 DEG C. for low density polyethylene, from 200 DEG to 320 DEG C. for high density polyethylene, from 225 DEG to 300 DEG C. for polymethylpentene, from 215 DEG to 300 DEG C. for polypropylene and from 275 DEG to 350 DEG C. for the copolymer of tetrafluorethylene and ethylene produces a blend of lower modulus suitable for electrical insulation.