Patent ID: 8653170
Filing Date: 2014-02-18
Classification: C08L

Abstract:
1. A process for preparing a thermoplastic vulcanizate composition comprising: melt-blending from 1 to 18 wt % thermoplastic polymer, based upon the total polymer, a cross-linkable elastomer, at least one curing agent, and a process oil such that the weight ratio of process oil to thermoplastic polymer ranges from 200:1 to 4:1; and isolating a thermoplastic vulcanizate composition exhibiting a level of extractables in room temperature cyclohexane not greater that 6 wt %, the composition having a durometer of less than 25 Shore A; wherein the cross-linkable elastomer is one or more of mono-olefin copolymer elastomers, EPDM or butyl rubber, wherein the thermoplastic polymer is one or more of propylene homopolymers or copolymers having a melt temperature due to isotactic arrangement of propylene derived monomers, as measured by DSC, from 50° C. to 175° C. a density of 0.90 to 0.91 g/cm wherein the thermoplastic vulcanizate composition consists of the reaction product of the thermoplastic polymer, the cross-linkable elastomer, the curing agent, and the process oil.