Granted Patent B2

US 7,935,766 · App. 12/650,625 · Granted May 3, 2011

Abstract

Claims (28)

1. A polymerization process comprising:

contacting, under polymerization conditions, propylene with a catalyst composition comprising a substituted phenylene aromatic diester in a first polymerization reactor;

forming an active propylene-based polymer;

contacting, under polymerization conditions, the active propylene-based polymer with at least one olefin in a second polymerization reactor; and

forming a propylene impact copolymer comprising a substituted phenylene aromatic diester.

2. The process of claim 1 comprising forming a propylene impact copolymer having a volatiles content less than about 30 μg/g in accordance with VW standard PV3341.

3. The process of claim 1 wherein the catalyst composition comprises aluminum, the process comprising adding an external electron donor to at least one of the polymerization reactors and maintaining an Al: EED ratio of less than 5.0.

4. The process of claim 3 comprising adding a single external electron donor.

5. The process of claim 1 comprising forming an active propylene-based polymer having a melt flow rate greater than 100 g/10 min as measured in accordance with ASTM D 1238, 2.16 kg, 230° C.

6. The process of claim 1 comprising forming a propylene impact copolymer having a melt flow rate greater than 40 g/10 min as measured in accordance with ASTM D 1238, 2.16 kg, 230° C.

7. The process of claim 1 comprising maintaining a H 2 /C 3 mole ratio of greater than 0.1 in the second polymerization reactor.

8. The process of claim 1 comprising contacting, in the second polymerization reactor, the active propylene-based polymer with propylene and ethylene and forming a propylene impact copolymer having an Fc value from about 5 wt % to about 50 wt % and an Ec value from about 20 wt % about 90 wt %.

9. A propylene impact copolymer comprising:

a propylene-based polymer;

a propylene/ethylene copolymer dispersed within the propylene-based polymer; and

a substituted phenylene aromatic diester.

10. The propylene impact copolymer of claim 9 wherein the substituted phenylene diester is present in a member selected from the group consisting of the propylene-based polymer, the propylene/ethylene copolymer, and combinations thereof.

11. The propylene impact copolymer of claim 9 comprising 3-methyl-5-tert-butyl-1,2 phenylene dibenzoate.

12. The propylene impact copolymer of claim 9 having a volatiles content less than about 30 μg/g as measured in accordance with VW standard PV3341.

13. The propylene impact copolymer of claim 9 wherein the propylene-based polymer has a melt flow rate (MFR) greater than about 100 g/10 min as measured in accordance with ASTM D 1238-01 (230° C., 2.16 kg).

14. The propylene impact copolymer of claim 9 wherein the propylene impact copolymer has a melt flow rate (MFR) greater than about 40 g/10 min as measured in accordance with ASTM D 1238-01 (230° C., 2.16 kg).

15. The propylene impact copolymer of claim 9 wherein the propylene-based polymer has a property selected from the group consisting of a xylene solubles content less than about 4%, a T MF greater than about 170° C., and combinations thereof.

16. The propylene impact copolymer of claim 9 wherein the propylene impact copolymer has an Fc value from about 5 wt % to about 50 wt %, an Ec value from about 20 wt % to about 90 wt %.

17. An article comprising:

a propylene impact copolymer comprising 3-methyl-5-tert-butyl-1,2 phenylene dibenzoate.

18. The article of claim 17 having a volatiles content less than about 30 μg/g as measured in accordance with VW standard PV3341.

19. The article of claim 17 selected from the group consisting of an extruded article, an injection molded article, a rotational molded article, a blow molded article, and a thermoformed article.

20. The article of claim 17 wherein the propylene impact copolymer has a melt flow rate greater than about 40 g/10 min as measured in accordance with ASTM D 1238-01(230° C., 2.16 kg).

Assignments (13)