Patent ID: 7655727
Filing Date: 2010-02-02
Classification: B29C,B29K,C08F

Abstract:
1. A process for the preparation of dynamically vulcanized thermoplastic elastomers comprising melt processing under shearing conditions in melt reaction extruder, A) at least one thermoplastic resin that is a polypropylene homopolymer, B) at least one vulcanizable gas-phase elastomer having a Mooney viscosity (ML 1+4 (125° C.)) of from about 80 to about 200, C) at least one curing agent that is a phenolic resin, and D) process oil, wherein said process oil D) is added to the extruder in at least three oil injection positions located: a) at least one location within the first 15% of the total length of the extruder; b) at least one other location prior to, at or within 10% total extruder length after the onset of the vulcanization of said gas-phase elastomer; and c) at least one location subsequent to the point at which the vulcanization of said gas-phase elastomer is substantially completed; and wherein the direct oil injection locations into the extruder are positioned at or immediately before one or more distributive mixing elements, which distributive mixing elements are immediately followed by one or more dispersive mixing elements, and wherein 9-18 phr oil is added in (a), 36-45 phr oil is added in (b), and 74.3-81 phr oil is added in (c).