Method for making free-flowing coated rubber pellets

摘要

Free flowing coated pellets are prepared by blending a first polymer with a second polymer wherein the second polymer is a polymer which has a crystalline or semicrystalline melting point which is at least 10° C. above the melting or softening point of the first polymer, the two polymers being insoluble in one another in the melt state; (2) intimately blending the two polymers; and (3) extruding the blend through a die having an outlet die face which is maintained at a substantially lower temperature than the extruder melt temperature. PPIn its preferred embodiment the first polymer is an elastomer and the second polymer comprises at least one crystalline or semi-crystalline plastic polymer. A typical composition comprises an EMP or EPDM rubber and a mixture of polyethylene and a crystalline copolymer of ethylene and propylene.