Patent ID: 7829641

Claim:
A process for making multimodal polyethylene resin comprising: (a) polymerizing ethylene or mixture of ethylene and C 3-8 α-olefin in a first reactor in the presence of hydrogen and a catalyst system comprised of a supported mixed indenoindolyl single site catalyst comprised of (5,10-dihydro-5,8-dimethylindeno[1,2-b]indole-10-yl)(cyclopentadienyl) zirconium dichloride and rac-ansa (methylene)bis(2,5-dimethyl-indeno[2,1-b]indolyl)zirconium dichloride, and an activator, to produce a polymerizate containing a first polyethylene resin having a density of 0.942 g/cm 3 or greater and MI 2 from 0.1 to 10 g/10 min; (b) removing substantially all hydrogen from the polymerizate and transferring to a second reactor; and (c) polymerizing ethylene and a C 3-8 α-olefin in the second reactor to produce a second polyethylene resin of relatively higher molecular weight and lower density than said first polyethylene resin and obtain a multimodal polyethylene resin product comprised of 30 to 55 weight percent first polyethylene resin and 45 to 70 weight percent second polyethylene resin and having a density from 0.940 to 0.960 g/cm 3 and HLMI from 2 to 50 g/10 min.