Claims
- 1. A method of making a solid procatalyst composition for use in a Ziegler-Natta olefin polymerization catalyst composition, said method comprising:
contacting a solid precursor composition comprising magnesium, titanium, and alkoxide moieties with a titanium halide compound and an internal electron donor in any order, in a suitable reaction medium to prepare a solid procatalyst composition, separating the solid procatalyst composition from the reaction medium, further exchanging residual alkoxide functionality of the solid procatalyst composition for chloride functionality by contacting the same two or more times with benzoyl chloride under metathesis conditions for a period of time sufficient to prepare a solid procatalyst composition having a decreased alkoxide content compared to the alkoxide content of the solid procatalyst composition before said exchange, and recovering the solid procatalyst composition.
- 2. The method of claim 1 wherein the internal electron donor is a C1-4 alkyl ester of an aromatic monocarboxylic or dicarboxylic acid, or a C1-4 alkyl ether derivative thereof.
- 3. The method of claim 2 wherein the internal electron donor is ethylbenzoate, ethyl p-ethoxybenzoate, di(n-butyl)phthalate, or di(isobutyl)phthalate.
- 4. The method of claim 1 wherein the exchange is conducted at a temperature from 45° C. to 120° C. for a time from 10 minutes to 3 hours.
- 5. The method of claim 1 wherein the exchange is conducted at a temperature within the range of from 70° C. to about 115° C. for a time from 30 to 90 minutes.
- 6. The method of claim 5 wherein exchange takes place at a temperature within the range of from 85° C. to 110° C. for a time from 40 to 80 minutes.
- 7. The method of claim 1 wherein the exchange is conducted three times.
- 8. The method of claim 1 where the solid procatalyst is also extracted one or more times with an inert diluent simultaneously or subsequently to said exchange.
- 9. The method of claim 1 wherein the solid procatalyst is contacted with a halide salt compound before or during the exchange step.
- 10. The method of claim 8 wherein the solid procatalyst is contacted with a halide salt compound before or during the exchange step.
- 11. A solid procatalyst composition for use in a Ziegler-Natta olefin polymerization catalyst composition prepared according to the method of claim 1.
- 12. A Ziegler-Natta olefin polymerization catalyst composition comprising a solid procatalyst composition of claim 11,
a cocatalyst; and a selectivity control agent.
- 13. A Ziegler-Natta olefin polymerization catalyst composition according to claim 11, wherein the selectivity control agent is ethyl p-methoxybenzoate, ethyl p-ethoxybenzoate, n-propyltrimethoxysilane, cyclohexylmethyldimethoxysilane, or dicyclopentyldimethoxy-silane.
- 14. A process for polymerizing an olefin monomer comprising contacting the olefin monomer under polymerization conditions with a Ziegler-Natta olefin polymerization catalyst composition according to claim 12.
- 15. A process according to claim 14 conducted in two or more gas-phase polymerization reactors operating in series wherein the polymer in an ethylene/propylene rubber modified polypropylene containing at least 40 weight percent rubber.
- 16. An olefin polymer prepared by the process recited in claim 14.
- 17. An ethylene/propylene rubber modified polypropylene according to claim 16 containing at least 40 weight percent rubber.
CROSS REFERENCE STATEMENT
[0001] This application claims the benefit of U.S. Provisional Application No. 60/294,183, filed May 29, 2001, the teachings of which are incorporated herein by reference.
Provisional Applications (1)
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Number |
Date |
Country |
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60294183 |
May 2001 |
US |