Patent ID: 8877867
Filing Date: 2014-11-04
Classification: C08K,C08L

Abstract:
1. A process for preparing a modified thermoplastic vulcanizate compositions, the process comprising the steps of: i. providing a molten thermoplastic vulcanizate, where the thermoplastic vulcanizate includes cured ethylene-propylene-diene rubber dispersed within a matrix of propylene polymer, where the propylene polymer comprises at least 97 wt % of propylene-derived units, based on the weight of the propylene polymer, and where the thermoplastic vulcanizate is prepared by dynamically vulcanizing the ethylene-propylene-diene rubber with a non-peroxide curative to provide a degree of cure where less than 5 wt % of the rubber is extractable by cyclohexane at 23° C., and where the thermoplastic vulcanizate comprises from 75 to 90 wt % of the ethylene-propylene-diene rubber and from 10 to 30 wt % of the propylene polymer based on the entire weight of the ethylene-propylene-diene rubber and the propylene polymer combined; ii. introducing 100 to 700 parts by weight of peroxide per million parts by weight of the thermoplastic vulcanizate to the molten thermoplastic vulcanizate to produce the modified thermoplastic vulcanizate composition, where the modified thermoplastic vulcanizate is further formed into an extrudate characterized by an extrusion surface roughness (ESR) of 76 to 108 microinches and where the ESR of the extrudate of the modified thermoplastic vulcanizate is at least 27.5% less than an ESR of an extrudate formed from the same thermoplastic vulcanizate not modified with the peroxide.