Ethylene alpha-olefin copolymers and methods

Patent metadata

Field	Value
Publication number	US-10654956-B2
Application number	US-201815962522-A
Country	US
Kind code	B2
Filing date	Apr 25, 2018
Priority date	May 3, 2017
Publication date	May 19, 2020
Grant date	May 19, 2020

Abstract

The present disclosure generally relates to ethylene alpha-olefin copolymers and methods of making ethylene alpha-olefin copolymers. The ethylene alpha-olefin copolymers may have a density of about 0.915 g/mL to about 0.918 g/mL, a rheological polydispersity index greater than 0.8, a melt index of about 0.4 dg/10 min to about 2.0 dg/10 min, and/or a CEF T50 of 84° C. or less. The ethylene alpha-olefin copolymers may be made by combining an ethylene monomer and one or more alpha-olefin monomers in the presence of a catalyst, such as a Ziegler-Natta catalyst.

First claim

What is claimed is:

1. An ethylene alpha-olefin copolymer comprising:
an ethylene monomer; and
an alpha-olefin monomer;
wherein the ethylene alpha-olefin copolymer comprises—
(i) a density of about 0.915 g/mL to about 0.918 g/mL,
(ii) a rheological polydispersity index greater than 0.8,
(iii) a melt index of about 0.4 dg/10 min to about 2.0 dg/10 min, and
(iv) a CEF T 50 of 84° C. or less.

2. The ethylene alpha-olefin copolymer of claim 1 , wherein the alpha-olefin monomer comprises one or more C 3 -C 10 alpha-olefins.

3. The ethylene alpha-olefin copolymer of claim 2 , wherein the alpha-olefin monomer comprises a C 6 alpha-olefin.

4. The ethylene alpha-olefin copolymer of claim 3 , wherein the C 6 alpha-olefin comprises hex-1-ene.

5. The ethylene alpha-olefin copolymer of claim 1 , wherein the ethylene alpha-olefin copolymer has a density of about 0.915 g/mL to about 0.917 g/mL.

6. The ethylene alpha-olefin copolymer of claim 1 , wherein the ethylene alpha-olefin copolymer has a density of about 0.916 g/mL.

7. The ethylene alpha-olefin copolymer of claim 1 , wherein the ethylene alpha-olefin copolymer has a melt index of about 0.4 dg/10 min to about 1.0 dg/10 min.

8. The ethylene alpha-olefin copolymer of claim 1 , wherein the ethylene alpha-olefin copolymer is film-shaped.

9. A method of producing an ethylene alpha-olefin copolymer comprising:
contacting an ethylene monomer and one or more alpha-olefin monomers in the presence of a Ziegler-Natta catalyst to produce the ethylene alpha-olefin copolymer;
wherein the ethylene alpha-olefin copolymer has—
(i) a density of about 0.915 g/mL to about 0.918 g/mL,
(ii) a rheological polydispersity index greater than 0.8,
(iii) a melt index of about 0.4 dg/10 min to about 2.0 dg/10 min, and
(iv) a CEF T 50 of 84° C. or less.

10. The method of claim 9 , further comprising forming a blown film of the ethylene alpha-olefin copolymer.

11. The method of claim 9 , wherein the Ziegler-Natta catalyst comprises:
(i) a compound according to the formula (I)—
MR x   (I),

wherein M is a transition metal of Groups IV to VI of the periodic table, R is a halogen, an alkoxy, or a hydrocarboxyl group, and x is the valence of the transition metal;
(ii) a co-catalyst; and
(iii) an internal donor (ID) comprising a C 3 -C 6 cyclic ether.

12. The method of claim 11 , wherein the co-catalyst comprises one or more organoaluminum compounds.

13. The method of claim 12 , wherein the co-catalyst comprises trimethylaluminum (TMA).

14. The method of claim 11 , wherein the Ziegler-Natta catalyst further comprises a catalyst support.

15. The method of claim 14 , wherein the catalyst support comprises MgCl 2 .

16. The method of claim 9 , wherein the Ziegler-Natta catalyst comprises:
(i) Mg;
(ii) Ti;
(iii) a halogen;
(iv) an electron donor compound; and
(v) a co-catalyst;
wherein the Ziegler-Natta catalyst has—
(a) a molar ratio Mg to Ti of at least 5:1,
(b) a molar ratio of Mg to electron donor of less than 2.1:1, and
(c) an X-ray diffraction spectrum comprising at least three 2θ diffraction angle peaks between 5.0° and 20.0°, wherein the at least three 2θ diffraction angle peaks comprise a first 2θ diffraction angle peak of 7.2±0.2°, a second 2θ diffraction angle peak of 11.5±0.2°, and a third 2θ diffraction angle peak of 14.5±0.2°, wherein the first 2θ diffraction angle peak of 7.2±0.2° is the most intense and the second 2θ diffraction angle peak of 11.5±0.2° has an intensity less than 0.9 times the intensity of the first 2θdiffraction angle peak.

17. The method of claim 16 , wherein the molar ratio of Mg to electron donor is about 1.1:1 to about 1.4:1.

18. The method of claim 16 , wherein the co-catalyst comprises one or more organoaluminum compounds.

19. The method of claim 18 , wherein the co-catalyst comprises trimethylaluminum (TMA).

20. The method of claim 16 , wherein the electron donor is an inner electron donor.

Assignees

• Equistar Chem Lp

Inventors

• Mavridis Harilaos
• Pica Roberta
• Baita Pietro
• Mei Gabriele
• Covezzi Massimo

Classifications

• C08F210/16 Primary

  Copolymers of ethene with alpha-alkenes, e.g. EP rubbers · CPC title

• C08F4/648

  inorganic · CPC title

• C08F4/6425

  containing magnesium · CPC title

• C08F4/022

  Magnesium halide as support anhydrous or hydrated or complexed by means of a Lewis base for Ziegler-type catalysts · CPC title

• C08F2500/12

  Melt flow index or melt flow ratio · CPC title