Soft polyolefin compositions with improved processability

摘要

Soft polyolefin composition with improved processability comprising from 8 to 45% by weight of a polypropylene component (A), from 82 to 45% by weight of an elastomeric component (B), and from 10 to 25% by weight of a viscosity reducing agent (C) comprising polybutene-1 and paraffinic wax or grease. The composition is easily processable also by injection molding and has better tensile properties than compositions in which processability is improved by visbreaking.

主权项

1. A polyolefin composition comprising:
(A) from 10 to 30% by weight of a polypropylene component comprising:
(i) a propylene homopolymer or(ii) a propylene copolymer with another α-olefin,wherein the polypropylene component contains at least 85% by weight of propylene, and has a solubility in xylene at room temperature lower than 20% by weight; (B) from 60 to 80% by weight of an elastomeric component comprising:
(i) a copolymer or a composition of copolymers of ethylene with propylene and/or at least one other α-olefin, containing from 15% by weight to 40% by weight of ethylene, the elastomeric component having a solubility in xylene at room temperature greater than 60% by weight; and (C) from 12 to 20% by weight of a viscosity reducing agent comprising:
homo or copolymer of butene-1, wherein the homo or copolymer of butene-1 has a melt flow rate from 100 and 500 g/10 min at 190° C./2.16 kg, anda paraffinic wax or grease, wherein the polyolefin composition has a melt flow rate equal to or greater than 1 g/10 min at 230° C./2.16 kg; and, wherein the homo or copolymer of butene-1 and the paraffin wax or grease are present in the reducing agent at a weight ratio from 2:1 to 1:2.