Ethylene copolymers with a novel composition distribution and processes for making the same

摘要

A Ziegler-Natta catalyzed ethylene copolymer having a novel composition distribution in which comonomers are incorporated into the high molecular weight polymer molecules and distributed evenly among the entire polyethylene chains, and a method for making the same are provided. The resins having a novel composition distribution have controlled molecular weight distribution which is narrower than conventional ZN-ethylene copolymers but broader than single-site catalyzed ethylene copolymers. The resins having a novel composition distribution exhibit a superior tear strength and impact strength.

主权项

1. A Ziegler-Natta catalyzed ethylene alpha-olefin copolymer, further comprising:
a density of between 0.900 g/cc and 0.930 g/cc; and a polydispersity index (Mw/Mn) of between 3.0 and 5.0; wherein the Temperature Raising Elution Fractionation (TREF) fraction distribution of the copolymer has at least 15 wt % of TREF fractions below an elution temperature of 35° C.; and wherein the molecular weight of the copolymer is substantially constant over the entire TREF fraction distribution.