Abstract: It has been discovered that using n-butylmethyldimethoxysilane (BMDS) as an external electron donor for Ziegler-Natta catalysts can provide a catalyst system that may prepare polypropylene films with improved properties. The catalyst systems of the invention provide for controlled chain defects/defect distribution and thus a regulated microtacticity. Consequently, the curve of storage modulus (G?) v. temperature is shifted such that the film achieves the same storage modulus at a lower temperature enabling faster throughput of polypropylene film through a high-speed tenter.
Type:
Grant
Filed:
October 4, 2005
Date of Patent:
April 10, 2007
Assignee:
Fina Technology, Inc.
Inventors:
Kenneth Paul Blackmon, David J. Rauscher, Michael R. Wallace