Patent ID: 9745461
Date: 2017-08-29
CPC Classifications: C08L

Claim:
1. A process for producing a heterogeneous vulcanized polymer blend comprising (a) a continuous phase comprising a thermoplastic polypropylene that is semi-crystalline; and (b) a dispersed phase comprising particles of an elastomeric copolymer different from the polypropylene dispersed in the continuous phase, the elastomeric copolymer having a crystallinity less than that of the polypropylene and being at least partially cross-linked, the process comprising: (i) polymerizing propylene to produce the thermoplastic polypropylene that is semi-crystalline and comprises vinyl terminal groups within the range from 0.40 vinyl/chain to 1.10 vinyl/chain; (ii) contacting at least part of the polypropylene with at least one second monomer and at least one α,ω-diene selected from the group consisting of butadiene, 1,4-pentadiene, 1,5-hexadiene, 1,6-heptadiene, 1,7-octadiene, 1,8-nonadiene, 1,9-decadiene, 1,10-undecadiene, 1,11-dodecadiene, 1,12-tridecadiene, and 1,13-tetradecadiene while maintaining reaction conditions below the cloud point of the thermoplastic polypropylene produced in the polymerizing (i) so as to (1) produce branch-block copolymers comprising an amorphous backbone having crystalline side chains originating from the thermoplastic polypropylene, and (2) produce, and simultaneously cross-link, the elastomeric copolymer as particles dispersed in the thermoplastic polypropylene, such that the degree of cross-link for the elastomeric copolymer particles dispersed in the thermoplastic polypropylene is within the range from 20% to 90%; and (iii) subjecting the product produced in (ii) to a vulcanization step by addition of a cross-linking agent to increase the amount of the elastomeric copolymer that is insoluble in xylene.