Patent ID: 9296885
Filing Date: 2016-03-29
CPC Classification: C08K,C08L

Claim Text:
1. A process for producing a thermoplastic vulcanizate, the process comprising: (i) dynamically vulcanizing a rubber with a curative in a first stage, where the rubber is within a blend that includes the rubber, a propylene homopolymer, oil and the curative, where said step of dynamically vulcanizing occurs at a temperature at or above the melting point of the propylene homopolymer, where said rubber is a terpolymer having units derived from ethylene, one or more α-olefins, and 0.1 to 3.0 mole % polymeric units deriving from 5-vinyl-2-norbornene, wherein said propylene homopolymer has an MFR of less than 1 g/10 min, where said curative is a peroxide curative present in the first stage in an amount of from 0.5 to 6 parts by weight per 100 parts by weight of the rubber, and where the weight ratio of the propylene homopolymer to the rubber is from 0.1:1 to 0.4:1, and where the oil is present in the first stage in an amount of from 50 to 200 parts by weight per 100 parts by weight of the rubber; (ii) continuing said step of dynamically vulcanizing to cause phase inversion of the blend to thereby convert the propylene homopolymer into a continuous phase; (iii) maintaining the blend at or above the melting point of the propylene homopolymer after the phase inversion; and (iv) introducing molten thermoplastic resin into the blend in a second stage, where the thermoplastic resin introduced into the blend in the second stage is a propylene homopolymer, propylene copolymer with ethylene, reactor propylene copolymer, or impact propylene copolymer, where said step of introducing molten thermoplastic resin occurs after phase inversion but before the blend is cooled to a temperature below the melting point of the propylene homopolymer;