Patent ID: 7632901
Filing Date: 2009-12-15
Classification: C08F

Abstract:
1. A process of polymerizing ethylene in a slurry polymerization reactor, the process comprising: (a) providing a supported chromium catalyst comprising: (b) providing a trialkylaluminum cocatalyst of formula AlR (c) contacting the catalyst and cocatalyst to form a catalyst system wherein the ratio of moles of cocatalyst to moles of chromium in the catalyst is in the range of 3:1 to 8:1 by: (d) contacting the catalyst system with a monomer feed consisting essentially of liquid phase ethylene, wherein the reactor is operated at a temperature and pressure sufficient to polymerize ethylene in a slurry phase; and (e) recovering a polymer having an ESCR of at least 500 hours according to ASTM D 1693, Condition B.