Multiple catalyst system and polymerization process for use thereof
AssigneeExxonMobil Chemical Patents Inc.
InventorsGlen E. Alliger, John W. Walzer, Jr.
Life of this patent
Estimating the term…
Abstract
This invention relates to a catalyst system comprising a half sandwich chromocene compound featuring a tethered N-donor, with an alumoxane and consequent supportation on silica produces a catalyst that produces ultra-high molecular weight polyethylene and that further supportation of a catalyst capable of producing linear low density polyethylene produces a multiple-catalyst system on the same support, capable of producing polyethylene with a bimodal molecular weight distribution and excellent molecular weight.
Claims25
A catalyst system comprising activator, support, catalyst compound represented by Formula I and catalyst compound represented by Formula II where:
- Formula I is
- where
- T is a bridging group;
- N is nitrogen;
- M* is Cr, Mo, or W, where M* is in a +3 oxidation state prior to contacting with activator;
- each X, is independently, selected from the group consisting of hydrocarbyl radicals having from 1 to 20 carbon atoms, hydrides, amides, alkoxides, sulfides, phosphides, halides, dienes, amines, phosphines, ethers, and a combination thereof, two X's optionally form a part of a fused ring or a ring system;
- each R1, R2, R3, and R4 is independently, hydrogen, a C1 to C12 hydrocarbyl, a substituted C1 to C12 hydrocarbyl, a heteroatom, or substituted heteroatom group;
- and each R5 and R6 is, independently, a C1 to C12 hydrocarbyl, a substituted C1 to C12 hydrocarbyl, a heteroatom, or substituted heteroatom group, where the R5 and R6 groups optionally form a fused ring or multicenter fused ring system where the rings are aromatic, partially saturated or saturated;
- and
- Formula II is:
- where
- M is Hf or Zr;
- z is 0 or 1;
- R1, R2, R3, R4, T and X, are as described above;
- and
- each R8, R9, R10, and R11 is, independently, hydrogen, a C1 to C12 hydrocarbyl, a substituted C1 to C12 hydrocarbyl, a heteroatom, or substituted heteroatom group.
Dependencies are inferred from the claim text.