Claims
- 1. A process for the polymerization of propylene with a Ziegler-type catalyst formulation comprising a transition metal catalyst component, an organosilicon electron donor component and an organoaluminum co-catalyst component, the steps comprising:(a) combining said organoaluminum co-catalyst component selected from the group consisting of trimethylaluminum and triethylaluminum with said transition metal catalyst component comprising titanium tetrachloride in relative amounts to formulate a precursor mixture having a molar ratio of aluminum to titanium from 200 to 400, wherein the precursor formulation of the organoaluminum co-catalyst and transition metal catalyst component is maintained for a time within the range of 5-120 seconds prior to subsequent contact with the organosilicon electron donor component; (b) combining said precursor mixture with said electron donor component comprising an organosilane to produce a Ziegler-type catalyst formulation of said transition metal catalyst component, electron donor component in relative amounts to provide an aluminum/silicon mole ratio of no more than 50; and (c) thereafter contacting said Ziegler-type catalyst mixture with propylene to effect polymerization of said propylene in the presence of said Ziegler-type catalyst mixture to produce a polymerization product.
- 2. The process of claim 1, wherein the mole ratio of aluminum to silicon in said mixture is within the range of 20-50.
- 3. The process of claim 1, wherein the ratio of silicon to titanium is within the range of 5-20.
- 4. The process of claim 1, wherein step (c) is carried out as a prepolymerization reaction to effect pre-polymerization of said Ziegler catalyst formulation and thereafter introducing said pre-polymerized catalyst into a polymerization reactor containing propylene.
- 5. The process claim 1, wherein said transition metal component is a titanium tetrahalide supported on a magnesium or zinc based support.
- 6. The process of claim 1, wherein said electron donor is an organodialkoxysilane.
- 7. The process of claim 6, wherein said electron donor is cyclohexalmethyldimethoxysilane.
- 8. A process for the polymerization of a C2-C4 alpha olefin with a Ziegler-type catalyst formulation comprising a transition metal catalyst component, an organosilicon electron donor component and an organoaluminum co-catalyst component, the steps comprising:(a) combining said organoaluminum co-catalyst component comprising an aluminum trialkyl or an aluminum alkyl halide with said transition metal catalyst component comprising a halide of titanium, zirconium or hafnium in relative amounts to formulate a precursor mixture having an aluminum to transition metal mole ratio from 200 to 400, wherein the precursor formulation of the organoaluminum co-catalyst and transition metal catalyst component is maintained for a time within the range of 5-120 seconds prior to subsequent contact with the organosilicon electron donor component; (b) combining said precursor mixture with said electron donor component comprising an organosilane to produce a Ziegler-type catalyst formulation of said transition metal catalyst component, electron donor component in relative amounts to provide an aluminum/silicon mole ratio of no more than 50; and (c) thereafter contacting said Ziegler-type catalyst mixture with a C2-C4 alpha olefin to effect polymerization of said olefin in the presence of said Ziegler-type catalyst mixture to produce a polymerization product.
- 9. The process of claim 8, wherein said C2-C4 alpha olefin comprises propylene.
- 10. The process of claim 9, wherein said transition metal component is a titanium tetrahalide supported on a magnesium or zinc based support.
- 11. The process of claim 9, wherein said co-catalyst is selected from the group consisting of trimethylaluminum and triethylaluminum.
- 12. The process of claim 9, wherein said electron donor is an organodiakoxysilane.
- 13. The process of claim 12, wherein said electron donor is cyclohexalmethyldimethoxysilane.
- 14. The process of claim 12, wherein said co-catalyst is trimethyaluminum or triethylaluminum.
- 15. The process of claim 8, wherein step (c) is carried out as a prepolymerization reaction to effect pre-polymerization of said Ziegler catalyst formulation and thereafter introducing said pre-polymerized catalyst into a polymerization reactor containing an olefin.
- 16. A process for the polymerization of propylene with a Ziegler-type catalyst formulation comprising a transition metal catalyst component, an organosilicon electron donor component and an organoaluminum co-catalyst component, the steps comprising:(a) combining said organoaluminum co-catalyst component comprising an aluminum trialkyl or an aluminum alkyl halide with said transition metal catalyst component comprising a halide of titanium, zirconium or hafnium in relative amounts to formulate a precursor mixture having an aluminum to transition metal mole ratio from 200 to 400, wherein the precursor formulation of the organoaluminum co-catalyst and transition metal catalyst component is maintained for a time within the range of 5-120 seconds prior to subsequent contact with the organosilicon electron donor component; (b) combining said precursor mixture with said electron donor component comprising an organosilane to produce a Ziegler-type catalyst formulation of said transition metal catalyst component, electron donor component in relative amounts to provide an aluminum/silicon mole ratio of no more than 50; and (c) contacting said Ziegler-type catalyst formulation with propylene to effect prepolymerization of said Ziegler-type catalyst formulation; and (d) thereafter introducing said prepolymerized catalyst formulation into a continuous loop-type polymerization reactor containing propylene to produce a polymerization product.
- 17. The process of claim 16, wherein said Ziegler catalyst formulation is pre-polymerization for a time period of less than one minute prior to introduction of said pre-polymerization catalyst formulation into said polymerization reactor.
Parent Case Info
This application is a continuation of prior application Ser. No. 07/846,930, filed Mar. 4, 1992 now abandoned.
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4767735 |
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Aug 1988 |
A |
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Continuations (1)
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Number |
Date |
Country |
Parent |
07/846930 |
Mar 1992 |
US |
Child |
09/643540 |
|
US |