Impact modification of thermoplastics with ethylene/alpha-olefin interpolymers

摘要

Impact modified compositions having good impact performance can be made from a thermoplastic (e.g., a polyolefin such as polypropylene or HDPE) and a multi-block ethylene/α-olefin interpolymer. The compositions are easily molded and often have particular utility in making, for example, automotive facia, parts and other household articles.

主权项

1. An impact modified composition comprising:
A) a thermoplastic polymer composition; and B) from 1 to 25 weight percent based on the total composition of an impact-modifying amount of a multi-block ethylene/C4-C12 α-olefin copolymer consisting of (i) at leas 60 mole percent ethylene and (ii) a C4-C12 α-olefin comonomer and having a linear block structure comprising hard segments and soft segments, the multi-block ethylene/C4-C12 α-olefin copolymer is polymerized in the presence of two polymerization catalysts having different comonomer incorporation indices, and a chain shutting agent and has a Mw/Mn from 1.7 to 3.5, at least one melting point, Tm, in degrees Celsius and a density, d, in grams/cubic centimeter, wherein the numerical values of Tm and d correspond to the relationship:
Tm>−2002.9+4538.5(d)−2422.2(d)2 wherein the amount of the hard segments is at least 30 weight percent to 70 weight percent, based on the total weight of the multi-block ethylene/α-olefin interpolymer.