High performance Ziegler-Natta catalyst systems, processes for producing such catalyst systems, and use thereof

摘要

A catalyst system for the polymerization of olefins may include a first solid catalytic component and a second solid catalytic component. The first solid catalytic component may include: a spherical MgCl2-xROH support; a group 4-8 transition metal; and a diether internal electron donor. The second solid catalytic component may include: a spherical MgCl2-xROH support; a group 4-8 transition metal; and a diether internal electron donor. The first solid catalytic component produces a propylene homopolymer having a Xylene Solubles (XS) value of greater than 2 wt %; and the second solid catalytic component produces a propylene homopolymer having a XS value of less than 2 wt %. The second catalytic component may act as an external electron donor during use, and embodiments herein do not require use of any additional external electron donors to control polymerization and reliably vary the properties of the resulting polymer.

主权项

1. A catalyst system useful for the polymerization of propylene or propylene copolymers, comprising:
a first solid catalytic component comprising:
a spherical MgCl2-xROH support, where x is in the range from about 1 to about 10 and wherein ROH is an alcohol or a mixture of at least two different alcohols;a group 4-8 transition metal; anda diether internal electron donor; a second solid catalytic component comprising:
a spherical MgCl2-xROH support, where x is in the range from about 1 to about 10 and wherein ROH is an alcohol or a mixture of at least two different alcohols;a group 4-8 transition metal; anda diether internal electron donor; wherein the molar ratio of diether internal electron donor to Mg in the first solid catalytic component is such that:
the first solid catalytic component produces a propylene homopolymer having a xylene solubles (XS) value of greater than 2 wt %; and wherein the molar ratio of diether internal electron donor to Mg in the second solid catalytic component is such that:
the second solid catalytic component produces a propylene homopolymer having a XS value of less than 2 wt %.