Abstract: A process for polymerizing ethylene is disclosed. The polymerization is performed in the presence of a Ziegler-Natta catalyst system in two slurry reaction zones. Most of the polyethylene (70-95 wt. %) is produced in one of the zones, while a smaller fraction is produced in the other zone. The ratio of the weight average molecular weight of the smaller fraction to that of the larger fraction is greater than 8:1. The resulting polyethylene blend, which should have both high melt strength and high extrudate swell, will be useful for blow-molding applications.
Type:
Grant
Filed:
November 30, 2006
Date of Patent:
October 13, 2009
Assignee:
Equistar Chemicals, IP
Inventors:
Harilaos Mavridis, Manivakkam J. Shankernararayanan