Catalyst composition with mixed selectivity control agent and method

Patent metadata

Field	Value
Publication number	US-10207238-B2
Application number	US-201113025532-A
Country	US
Kind code	B2
Filing date	Feb 11, 2011
Priority date	Aug 24, 2007
Publication date	Feb 19, 2019
Grant date	Feb 19, 2019

Abstract

The present disclosure provides a Ziegler-Natta catalyst composition comprising a procatalyst, a cocatalyst and a mixed external electron donor comprising a first selectivity control agent, a second selectivity control agent, and an activity limiting agent. A polymerization process incorporating the present catalyst composition produces a high-stiffness propylene-based polymer with a melt flow rate greater than about 50 g/10 min. The polymerization process occurs in a single reactor, utilizing standard hydrogen concentration with no visbreaking.

First claim

I claim:

1. A propylene-based polymer comprising:
dicyclopentyldimethoxysilane, an ethoxysilane, and at least about 5 ppm to about 150 ppm of an activity limiting agent (ALA) comprising a C 4 -C 30 aliphatic acid monoester, polymer wherein a mole ratio of dicyclopentyldimethoxysilane to ethoxysilane is 0.1-1:1, the propylene-based polymer:
(A) having a melt flow rate greater than about 100 g/10 min as measured in accordance with ASTM D 1238-01 at 230° C., 2.16 kg;
(B) having a xylene solubles content of from 0.1 weight percent to less than 2 weight percent;
(C) exhibiting a T MF greater than about 165° C.;
(D) wherein the ratio of combined moles of dicyclopentyldimethoxysilane and ethoxysilane to moles of activity limiting agent is about 0.43-2.33:1; and
(E) wherein the mole ratio of dicyclopentyldimethoxysilane to combined moles of dicyclopentyldimethoxysilane and ethoxysilane is about 0.2-0.5:1.

2. The propylene-based polymer of claim 1 wherein the ALA comprises isopropyl myristate.

3. The propylene-based polymer of claim 1 wherein the propylene-based polymer is uncracked.

4. The propylene-based polymer of claim 1 wherein the propylene-based polymer is a propylene homopolymer.

5. The propylene-based polymer of claim 1 comprising a silicon content less than about 200 ppm.

6. The propylene-based polymer of claim 1 comprising from about 1 ppm to about 100 ppm dicyclopentyldimethoxysilane.

7. The propylene-based polymer of claim 1 comprising a post-reactor oligomer content less than about 3000 ppm.

8. The propylene-based polymer of claim 1 wherein the ethoxysilane is selected from the group consisting of a diethoxysilane, a triethoxysilane, a tetraethoxysilane, and combinations thereof.

9. The propylene-based polymer of claim 1 wherein the ethoxysilane is selected from the group consisting of methylcyclohexyldiethoxysilane, diisobutyldiethoxysilane, tetraethoxysilane, n-propyltriethoxysilane, benzyltriethoxysilane, butenyltriethoxysilane, and (triethoxysilyl)cyclohexane.

10. The propylene-based polymer of claim 1 comprising tetraethoxysilane, and the ALA comprises isopropyl myristate.

11. The propylene-based polymer of claim 1 comprising n-propyltriethoxysilane, and the ALA comprises isopropyl myristate.

12. The propylene-based polymer of claim 1 comprising a phenylene dibenzoate.

13. The propylene-based polymer of claim 1 comprising 3-methyl-5-tert-butyl-1,2-phenylene dibenzoate.

14. The propylene-based polymer of claim 1 comprising a T MF greater than 170° C.

15. The propylene-based polymer of claim 1 comprising a T MF greater than 170° C. and a post-reactor oligomer content of less than about 3000 ppm.

16. A propylene-based polymer comprising:
dicyclopentyldimethoxysilane, an ethoxysilane, and at least about 5 ppm to about 150 ppm of an activity limiting agent (ALA) comprising a C 4 -C 30 aliphatic acid monoester, wherein a mole ratio of dicyclopentyldimethoxysilane to ethoxysilane is 0.1-1:1, wherein the ethoxysilane is selected from the group consisting of a diethoxysilane, a tetraethoxysilane, and combinations thereof, the propylene-based polymer:
(A) having a melt flow rate greater than about 100 g/10 min as measured in accordance with ASTM D 1238-01 at 230° C., 2.16 kg;
(B) having a xylene solubles content of from 0.1 weight percent to less than 2 weight percent;
(C) exhibiting a T MF greater than about 165° C.;
(D) wherein the ratio of combined moles of dicyclopentyldimethoxysilane and ethoxysilane to moles of activity limiting agent is about 0.43-2.33:1; and
(E) wherein the mole ratio of dicyclopentyldimethoxysilane to combined moles of dicyclopentyldimethoxysilane and ethoxysilane is about 0.2-0.5:1.

17. A propylene-based polymer comprising:
dicyclopentyldimethoxysilane, an ethoxysilane, wherein a mole ratio of dicyclopentyldimethoxysilane to ethoxysilane is 0.1-1:1, and at least about 5 ppm to about 150 ppm of an activity limiting agent (ALA) comprising a C 4 -C 30 aliphatic acid monoester, the propylene-based polymer:
(A) having a melt flow rate greater than 100 g/10 min as measured in accordance with ASTM D 1238-01 at 230° C., 2.16 kg;
(B) having a xylene solubles content of from 0.1 weight percent to less than 2 weight percent;
(C) exhibiting a T MF greater than about 165° C.;
(D) wherein the ratio of combined moles of dicyclopentyldimethoxysilane and ethoxysilane to moles of activity limiting agent is about 0.43-2.33:1; and
(E) wherein the mole ratio of dicyclopentyldimethoxysilane to combined moles of dicyclopentyldimethoxysilane and ethoxysilane is about 0.2-0.5:1.

Assignees

• Chen Linfeng
• Grace W R & Co

Inventors

• Chen Linfeng

Classifications

• C08F2/00

  Processes of polymerisation · CPC title

• B01J31/2226

  Anionic ligands, i.e. the overall ligand carries at least one formal negative charge · CPC title

• B01J8/1809

  Controlling processes · CPC title

• C08F2500/18

  Bulk density · CPC title

• C08F2500/12

  Melt flow index or melt flow ratio · CPC title