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 DEG C. above the melting or softening point of the 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. In its preferred embodiment the first polymer is an elastomer and the second polymer comprises at least one crystalline or semicrystalline plastic polymer. A typical composition comprises an EPM or EPDM rubber and a mixture of polyethylene and a crystalline copolymer of ethylene and propylene.