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US 9,434,795 B2Granted
Production of vinyl terminated polyethylene using supported catalyst system
AssigneeExxonMobil Chemical Patents Inc.
InventorsDonna J. Crowther, Patrick Brant
Life of this patent
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Abstract
This invention relates to processes to produce vinyl terminated polyethylene involving contacting ethylene with a supported metallocene catalyst system; wherein the supported catalyst system comprises a support material; an alumoxane activator; and a metallocene compound. A supported metallocene catalyst system is also disclosed. Processes to produce ethylene copolymers are also disclosed.
Claims26
A process to produce polyethylene comprising:
- (a) contacting ethylene with a supported metallocene catalyst system;
- wherein the supported catalyst system comprises:
- (i) a support material;
- (ii) an alumoxane activator having from about 1 wt % to about 14 wt % trimethylaluminum, based on the weight of the alumoxane activator;
- (iii) a metallocene compound represented by the formula:
- wherein
- T is Si or Ge;
- each RA is a C1 to C20 substituted or unsubstituted hydrocarbyl group;
- each RB is, independently, H or a C1 to C8 substituted or unsubstituted hydrocarbyl group, or a group represented by the formula —CH2Rx;
- wherein Rx is a C1 to C20 substituted or unsubstituted hydrocarbyl group provided that at least one RB is methyl or a group represented by the formula —CH2Rx;
- each RC is, independently, H or a C1 to C20 substituted or unsubstituted hydrocarbyl group;
- each A is independently selected from the group consisting of C1 to C20 substituted or unsubstituted hydrocarbyl groups, hydrides, amides, amines, alkoxides, sulfides, phosphides, halides, dienes, phosphines, and ethers, and two A groups can form a cyclic structure including aromatic, partially saturated, or saturated cyclic or fused ring system;
- each X is, independently, hydrogen, halogen or a substituted or unsubstituted C1 to C20 hydrocarbyl, and two X groups can form a cyclic structure including aromatic, partially saturated, or saturated cyclic or fused ring system;
- further provided that any of adjacent RA, RB, and/or RC groups may form a fused ring or multicenter fused ring systems, where the rings may be substituted or unsubstituted, and may be aromatic, partially unsaturated, or unsaturated;
- (b) obtaining a vinyl terminated polyethylene having:
- (i) at least 60% allyl chain ends, based on total unsaturations;
- (ii) a molecular weight distribution of less than or equal to 4.0;
- (iii) an Mn (1HNMR) of at least 20,000 g/mol;
- and
- (iv) wherein the polyethylene is an ethylene polymer having less than 2wt % of a C3 to C40 alphaolefin comonomer.
17 more elements
Dependencies are inferred from the claim text.