Olefin polymerization process
A slurry process for polymerizing ethylene is disclosed. The process comprises polymerizing ethylene in the presence of an α-olefin, hydrogen, and a catalyst comprising an activator and a supported, dimethylsilyl-bridged bis(indenoindolyl)zirconium complex. The process has high catalyst activity and produces polyethylene having a broad molecular weight distribution.
1. A slurry process which comprises polymerizing ethylene at a temperature within the range of about 40° C. to about 90° C. in the presence of a C 3 -C 10 α-olefin, hydrogen, and a catalyst comprising an activator and a supported, dimethylsilyl-bridged bis(indeno-indolyl)zirconium complex to produce polyethylene with broad molecular weight distribution as indicated by a M w /M n greater than 12, wherein the catalyst has an activity ratio as defined herein greater than 4.
2. The process of claim 1 wherein the complex has the structure:
wherein each L′ is an indenoindolyl ligand and each L is independently selected from the group consisting of halide, alkoxy, aryloxy, siloxy, alkylamino, and C 1 -C 30 hydrocarbyl.
3. The process of claim 1 wherein the complex has a structure selected from the group consisting of:
wherein each R 1 is independently selected from the group consisting of C 1 -C 10 hydrocarbyl; each R 2 is independently selected from the group consisting of H, F, and C 1 -C 10 hydrocarbyl; and each L is independently selected from the group consisting of halide, alkoxy, aryloxy, siloxy, alkylamino, and C 1 -C 30 hydrocarbyl.
4. The process of claim 1 wherein the C 3 -C 10 α-olefin is selected from the group consisting of 1-butene, 1-hexene, and 1-octene.
5. The process of claim 1 capable of forming polyethylene having a weight-average molecular weight greater than 100,000.
6. The process of claim 1 wherein 63 mmoles of 1-butene per mole of ethylene in the liquid phase forms polyethylene with greater than 5 tertiary carbons per 1000 carbons.
7. The process of claim 1 wherein introduction of 0.82 mmoles of hydrogen per mole of ethylene into the liquid phase reduces the weight-average molecular weight by at least 60%.
8. The process of claim 1 wherein the supported complex is supported on silica.
9. The process of claim 1 wherein the activator is selected from the group consisting of alumoxanes, alkylaluminum compounds, organoboranes, ionic borates, ionic aluminates, aluminoboronates, and combinations thereof.
10. The process of claim 9 wherein the activator is methylalumoxane.
11. The process of claim 3 wherein the complex has the structure:
wherein each R 1 is independently selected from the group consisting of C 1 -C 10 hydrocarbyl; and each L is independently selected from the group consisting of halide, alkoxy, aryloxy, siloxy, alkylamino, and C 1 -C 30 hydrocarbyl.
12. The process of claim 11 wherein each R 1 is methyl.
13. The process of claim 11 wherein each R 1 is phenyl.
14. The process of claim 3 wherein the complex has the structure:
wherein each L is independently selected from the group consisting of halide, alkoxy, aryloxy, siloxy, alkylamino, and C 1 -C 30 hydrocarbyl.