Process for preparing curable polyolefin polymers

Abstract

The disclosure is directed to improvements in a process for preparing curable polyolefin polymers in which a mass of dry, discrete, free-flowing particles of polyolefin polymer is tumbled in admixture with a curing agent effective to cause curing when the finished product is subjected to curing temperature, which comprises tumbling said mass in two separate and discrete steps in which essentially all of the curing agent is incorporated into said mass in the first tumbling step and equilibration between the curing agent and the polymer is effected in the second tumbling step while maintaining in both tumbling steps a temperature above the melting point of said curing agent but below both the agglomerating temperature and the curing temperature and, at least in the second tumbling step, a temperature which provides equilibration between the curing agent and the polymer; and thereafter tumble-cooling the thus-treated mass until a dry, discrete, free-flowing mass of polymer particles is obtained. The tumbling steps are advantageously effected in a Zig-Zag Blender.TM., wherein incorporation of the curing agent is effected by spraying liquid curing agent onto particles of said polymer while they are separated from said mass and dispersed in the atmosphere which envelopes said mass.

Dependencies are inferred from the claim text.