| US 7,473,745 B2 | ||
| Preparation of multimodal polyethylene | ||
| Venki Chandrashekar, Houston, Tex. (US); Mark P. Mack, West Chester, Ohio (US); Charles H. Gates, Jr., Lake Jackson, Tex. (US); Charles S. Holland, Coal City, Ill. (US); Natalia Nagy, Naperville, Ill. (US); Sandor M. Nagy, Naperville, Ill. (US); Edward S. Vargas, Loveland, Ohio (US); and Jean A. Merrick-Mack, West Chester, Ohio (US) | ||
| Assigned to Equistar Chemicals, LP, Houston, Tex. (US) | ||
| Filed on Sep. 02, 2005, as Appl. No. 11/218,888. | ||
| Prior Publication US 2007/0055021 A1, Mar. 08, 2007 | ||
| Int. Cl. C08F 4/06 (2006.01) | ||
| U.S. Cl. 526—65 [526/73; 526/79; 526/113; 526/118; 526/161; 526/172; 526/348.2; 526/348.3; 526/348.6; 526/352] | 7 Claims |
| 1. A multi-stage process comprising:
(a) polymerizing, in the presence of two or more single-site catalysts, ethylene or a mixture of ethylene and a C3 to C10 α-olefin at a hydrogen/monomer molar ratio within the range of about 0.0001/1 to about 10/1 to produce a first multimodal
resin; and
(b) continuing the polymerization in the presence of the same catalysts as in stage (a) at a reduced hydrogen/monomer ratio
to produce a second multimodal resin;
wherein the single-site catalysts comprise an indenoindolyl catalyst.
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