High stiffness polypropylene impact copolymer

Abstract

Disclosed is a polypropylene with an MFR of at least 20 g/10 min comprising a homopolypropylene and optionally within a range from 2 wt % to 30 wt % of an propylene-α-olefin copolymer by weight of the polypropylene; wherein the homopolypropylene has a MFR within a range from 30 g/10 min to 200 g/10 min, an Mw/Mn within a range from 7 to 16, and comprising 1.1 wt % or less atactic polypropylene based on the total weight of the homopolypropylene and atactic polypropylene, where the propylene-α-olefin copolymer has within a range from 30 wt % to 50 wt % α-olefin derived units by weight of the propylene-α-olefin copolymer, and an intrinsic viscosity within a range from 4 to 8 dL/g. The impact copolymer may be obtained by combining a Ziegler-Natta catalyst having at least two different internal electron donors with propylene in reactors in series to produce the homopolypropylene followed by a gas phase reactor to produce a propylene-α-olefin copolymer.