Chevron Phillips Chemical Company LP

Kevin J Taylor

James A Solis

Charles D Mills

David L Beach

Gene E Kellum

Javier M Mora

Mary A Schexnayder

The present invention is directed to producing a resin which, when formed into a film, has excellent gas barrier and/or moisture barrier (low MVTR) properties. Further, the resin has a relatively high molecular weight distribution, preferably above 6, and has excellent processability/extrudability. The resin is produced using a cyclopentadienyl chromium compound, preferably a mono CpCr compound, on a support, preferably a silica support. A particularly preferred catalyst for use in the present invention comprises pentamethylcyclopentadienyidimethylchromiumpyridine. Preferably, the catalyst is used in a slurry polymerization process.

Process for making MVTR resin

A process is disclosed for producing polyethylene resin of broad molecular weight distribution, when formed into a film, high barrier to moisture (low MVTR (Moisture Vapor Transmission Rate) for the film). The resin is formed by polymerizing ethylene, preferably in a gas phase process or in a slurry process, using a post-titanated catalyst, that is, a catalyst wherein after initial formation of a catalyst comprising Cr&mdash;Ti-inorganic refractory support, further titanium is added to the catalyst in a post-titanation step, preferably to increase the titanium content of the catalyst to a final level preferably between 7 and 9.5 wt. %.

MVTR resin produced with post-titanated Cr/Si/Ti catalyst

Growing community of inventors

Orange, TX, United States of America

Kevin J Taylor