Patent ID: 7491771
Filing Date: 2009-02-17
Classification: C08K,C08L

Abstract:
1. A process for producing a thermoplastic olefinic rubber composition comprising (A) 1 to 99 parts by weight of an ethylene-α-olefin copolymer having ethylene units and C 3 -C 20 α-olefin units, and (B) 1 to 99 parts by weight of a thermoplastic olefinic resin, the total amount of (A) and (B) being 100 parts by weight, said (A) having a degree of crosslinking of 50% or more and a degree of swelling of 5 to 40, wherein said thermoplastic olefinic resin (B) is selected from the group consisting of polyethylenes, isotactic homopolypropylenes and isotactic (block and random) copolymers of propylene and other α-olefin selected from the group consisting of ethylene, butane-1, pentene-1 and hexane-1; the process comprising the steps of using a radical initiator (D) having a one-minute half-life temperature T setting an extruder zone with a length of 0.1L to 0.5L at a melting temperature T and controlling degree of mixing M defined as in a range of 10×10 6 ≦M≦1,000×10 6 wherein L is extruder length (mm), D is inner diameter (mm) of extruder barrel, Q is discharge rate (kg/h) and N is screw rotation speed (rpm).