Unsymmetrical metallocene catalysts and uses thereof

Patent metadata

Field	Value
Publication number	US-11053269-B2
Application number	US-201716099855-A
Country	US
Kind code	B2
Filing date	May 10, 2017
Priority date	May 12, 2016
Publication date	Jul 6, 2021
Grant date	Jul 6, 2021

Abstract

Unsymmetrical metallocene compounds based on cyclopentadienyl ligands are disclosed, as well as catalytic compositions comprising the compounds supported on solid support materials. The compounds and compositions are useful as catalysts in the polymerisation of olefins. In particular, the compounds and compositions are useful catalysts in the preparation of low molecular weight polyethylene (e.g. polyethylene wax) and copolymers formed from the polymerisation of ethylene and other α-olefins.

First claim

The invention claimed is:

1. A compound of formula (I):

wherein
R 1 , R 2 , R 3 and R 4 are each independently selected from hydrogen or (1-4C)alkyl;
R a and R b are each independently (1-4C)alkyl;
X is zirconium or hafnium; and
each Y is independently selected from halo, phenyl, aryl(1-2C)alkyl, or (CH 2 ) z Si(CH 3 ) 3 , any of which is optionally substituted with one or more (1-3C)alkyl or halo;
wherein z is 1, 2 or 3;
or each Y is independently chloro, methyl, propyl, neopentyl, phenyl, benzyl, or —CH 2 Si(CH 3 ) 3 ;
with the proviso that at least one of R 1 , R 2 , R 3 and R 4 is not hydrogen.

2. The compound of claim 1 , wherein each Y is independently chloro, methyl, propyl, neopentyl, phenyl, benzyl, or —CH 2 Si(CH 3 ) 3 .

3. The compound of claim 1 , wherein at least one Y group is chloro, methyl or benzyl.

4. The compound of claim 1 , wherein both Y groups are chloro, methyl or benzyl.

5. The compound of claim 1 , wherein the compound of formula (I) has a structure according to formula (Ia) or (Ib):

wherein
R a and R b are each independently (1-4C)alkyl;
each Y is independently selected from halo, phenyl, aryl(1-2C)alkyl, or (CH 2 ) z Si(CH 3 ) 3 , any of which is optionally substituted with one or more (1-3C)alkyl or halo;
m is 1, 2, 3, or 4; and
Q is n-butyl or t-butyl.

6. The compound of claim 1 , wherein the compound has a structure according to formula (Ie) or (If):

wherein
m is 1, 2 3 or 4; and
Q is n-butyl or t-butyl.

7. The compound of claim 1 , wherein the compound has any one of the following structures:

8. A composition comprising the compound of formula (I) of claim 1 , and a support material.

9. The composition of claim 8 , wherein the support material is solid MAO.

10. The composition of claim 9 , wherein a mole ratio of support material to the compound of formula (I) is 50:1 to 500:1.

11. A polymerisation process comprising the step of
polymerising one or more olefins in the presence of
the composition of claim 8 .

12. The process of claim 11 , wherein the one or more olefins is ethylene.

13. The process of claim 12 , wherein ethylene is polymerised in the presence of
hydrogen.

14. The process of claim 13 , wherein a mole ratio of hydrogen to ethylene ranges from 0.005:1 to 0.08:1.

15. The process of claim 11 , wherein the one or more olefins is ethylene and one or more (3-8C)α-olefin.

16. The process of claim 15 , wherein a quantity of the one or more (3-8C)α-olefin, relative to a quantity of ethylene, is 0.05-10 mol %.

17. The process of claim 15 , where the step of polymerizing is conducted in the presence of one of more compounds selected from triethyl aluminium, methyl aluminoxane, trimethyl aluminium and triisobutyl aluminium.

18. A polymerisation process comprising a step of:
polymerising ethylene in the presence of hydrogen and
a composition comprising solid MAO and a compound according to formula (II)

wherein X is zirconium or hafnium;

wherein a mole ratio of hydrogen to ethylene ranges from 0.0365:1 to 0.3:1.

19. The process of claim 18 , wherein a mole ratio of solid MAO to the compound of formula (II) is 125:1 to 400:1.

20. The process of claim 18 , where the step of polymerizing is conducted in the presence of one of more compounds selected from triethyl aluminium, methyl aluminoxane, trimethyl aluminium or triisobutyl aluminium.

Assignees

• Scg Chemicals Co Ltd

Inventors

• O'Hare Dermot
• Buffet Jean-Charles
• LAMB Jessica
• Khamnaen Tossapol
• Charernsuk Manutsavin
• Parawan Thawesak
• Charoenchaidet Sumate

Classifications

• C08F4/65927

  two cyclopentadienyl rings being mutually bridged · CPC title

• C08F4/65916

  supported on a carrier, e.g. silica, MgCl2, polymer · CPC title

• C08F4/65912

  in combination with an organoaluminium compound · CPC title

• C07F17/00 Primary

  Metallocenes · CPC title

• C08F10/02

  Ethene · CPC title