Self limiting catalyst composition and propylene polymerization process
View Patent ↗A catalyst composition for the polymerization of propylene comprising one or more Ziegler-Natta procatalyst compositions comprising one or more transition metal compounds and one or more esters of aromatic dicarboxylic acid internal electron donors; one or more aluminum containing cocatalysts; a selectivity control agent (SCA) comprising at least one silicon containing compound containing at least one C 1-10 alkoxy group bonded to a silicon atom, and one or more activity limiting agent (ALA) compounds comprising one or more aliphatic or cycloaliphatic carboxylic acids; alkyl-, cycloalkyl- or alkyl(poly)(oxyalkyl)-(poly)ester derivatives thereof; or inertly substituted derivatives of the foregoing.
1. A polymerization process comprising:
charging an effluent of a first polymerization reactor to a second polymerization reactor;
contacting the effluent with propylene and a copolymerizable comonomer under polymerization conditions in the second polymerization reactor;
adding a mixture of a selectivity control agent (SCA) comprising one or more silicon containing compounds and an activity limiting agent (ALA) selected from the group consisting of a C 1-20 alkyl ester of an aliphatic C 8-20 monocarboxylic acid, a C 2-20 alkyl mono- or poly-carboxylate derivative of a C 2-100 polyglycol, and combinations thereof to the second polymerization reactor; and
forming a copolymer.
2. The polymerization process of claim 1 wherein the effluent comprises a polypropylene and the copolymerizable copolymer is ethylene, the process comprising forming a copolymer of propylene and ethylene in the presence of the polypropylene in the second reactor.
3. The process of claim 1 comprising adding the SCA/ALA mixture to the second reactor and eliminating fouling in the second reactor.
4. The polymerization process of claim 1 comprising mixing the ALA with the SCA before the adding.
5. The process of claim 1 comprising forming the SCA/ALA mixture in the second reactor in situ.
6. The process of claim 1 comprising imparting no undesired odor to the copolymer.
7. A polymerization process comprising:
preparing a polypropylene in a first polymerization reactor;
preparing a copolymer of ethylene and propylene in the presence of the polypropylene in a second polymerization reactor; and
adding, to at least one of the polymerization reactors, a mixture of a selectivity control agent (SCA) comprising one or more silicon containing compounds and an activity limiting agent (ALA) selected from the group consisting of a C 1-20 alkyl ester of an aliphatic C 8-20 monocarboxylic acid, a C 2-20 alkyl mono- or poly-carboxylate derivative of a C 2-100 polyglycol, and combinations thereof.
8. The process of claim 7 comprising adding the SCA/ALA mixture to a member selected from the group consisting of the first polymerization reactor, the second polymerization reactor, and combinations thereof.
9. The process of claim 7 comprising adding the SCA/ALA mixture to the second polymerization reactor.
10. The process of claim 7 comprising adding a first SCA/ALA mixture to the first polymerization reactor and adding a second SCA/ALA mixture to the second reactor.
11. The process of claim 7 comprising forming, in the second polymerization reactor, a copolymer comprising the polypropylene and the copolymer of ethylene and propylene.
12. The polymerization process of claim 7 comprising adding a mixture comprising the SCA and an ALA selected from the group consisting of a C 1-20 alkyl ester of an aliphatic C 8-20 monocarboxylic acid, a C 2-20 alkyl mono- or poly-carboxylate derivative of a C 2-100 polyglycol, and combinations thereof.
13. The process of claim 7 comprising adding the SCA/ALA mixture to the second polymerization reactor; and eliminating fouling in the second polymerization reactor.
14. A polymerization process comprising:
preparing a copolymer of ethylene and propylene in the presence of a polypropylene in a polymerization reactor under polymerization conditions; and
adding, to the polymerization reactor, a mixture of a selectivity control agent (SCA) comprising one or more silicon containing compounds and an activity limiting agent (ALA) selected from the group consisting of a C 1-20 alkyl ester of an aliphatic C 8-20 monocarboxylic acid, a C 2-20 alkyl mono- or poly-carboxylate derivative of a C 2-100 polyglycol, and combinations thereof.
15. The polymerization process of claim 14 comprising adding a mixture comprising the SCA and an ALA selected from the group consisting of a C 1-20 alkyl ester of an aliphatic C 8-20 monocarboxylic acid, a C 2-20 alkyl mono- or poly-carboxylate derivative of a C 2-100 polyglycol, and combinations thereof.
16. The polymerization process of claim 14 comprising eliminating, with the addition of the SCA/ALA mixture, fouling in the polymerization reactor.
17. The polymerization process of claim 14 comprising separately adding the ALA and separately adding the SCA to the polymerization reactor.
18. The polymerization process of claim 14 comprising mixing the ALA and the SCA before the adding.
19. The polymerization process of claim 14 comprising preparing the polypropylene in a first polymerization reactor and preparing the copolymer of ethylene and propylene in a second polymerization reactor.