Silica-coated alumina activator-supports for metallocene catalyst compositions

Patent metadata

Field	Value
Publication number	US-10676553-B2
Application number	US-201916266176-A
Country	US
Kind code	B2
Filing date	Feb 4, 2019
Priority date	Mar 20, 2008
Publication date	Jun 9, 2020
Grant date	Jun 9, 2020

Abstract

Silica-coated alumina activator-supports, and catalyst compositions containing these activator-supports, are disclosed. Methods also are provided for preparing silica-coated alumina activator-supports, for preparing catalyst compositions, and for using the catalyst compositions to polymerize olefins.

First claim

We claim:

1. An activator-support comprising a silica-coated alumina treated with an electron-withdrawing anion, wherein:
the silica-coated alumina has a weight ratio of alumina to silica in a range from about 1:1 to about 2:1 and a surface area in a range from about 200 to about 600 m 2 /g; and
the electron-withdrawing anion comprises fluoride.

2. The activator-support of claim 1 , wherein the weight ratio of alumina to silica is in a range from about 1.2:1 to about 1.8:1.

3. The activator-support of claim 1 , wherein the silica-coated alumina is further characterized by:
a surface area in a range from about 250 to about 500 m 2 /g; and
a pore volume in a range from about 0.5 to about 1.8 mL/g.

4. The activator-support of claim 1 , wherein the activator-support contains from about 2 to about 15 wt. % fluoride.

5. The activator-support of claim 4 , wherein the silica-coated alumina is further characterized by an average particle size in a range from about 5 to about 150 microns.

6. The activator-support of claim 4 , wherein the silica-coated alumina is further characterized by:
a surface area in a range from about 250 to about 500 m 2 /g; and
a pore volume in a range from about 1 to about 1.6 mL/g.

7. The activator-support of claim 6 , wherein the silica-coated alumina is further characterized by an average particle size in a range from about 30 to about 100 microns.

8. The activator-support of claim 1 , wherein the activator-support is further characterized by:
a surface area in a range from about 200 to about 500 m 2 /g; and
a pore volume in a range from about 0.8 to about 1.8 mL/g.

9. The activator-support of claim 1 , wherein:
the weight ratio of alumina to silica is in a range from about 1.2:1 to about 1.8:1; and
the activator-support contains from about 3 to about 12 wt. % fluoride.

10. The activator-support of claim 9 , wherein the silica-coated alumina is further characterized by
a pore volume in a range from about 0.8 to about 1.7 mL/g.

11. The activator-support of claim 9 , wherein the electron-withdrawing anion further comprises sulfate or phosphate.

12. The activator-support of claim 9 , wherein the activator-support is further characterized by:
a surface area in a range from about 200 to about 500 m 2 /g; and
a pore volume in a range from about 1 to about 1.6 mL/g.

13. A process for preparing an activator-support, the process comprising:
contacting a silica-coated alumina with a fluoriding agent to form the activator-support;
wherein the silica-coated alumina has a weight ratio of alumina to silica in a range from about 1:1 to about 2:1 and a surface area in a range from about 200 to about 600 m 2 /g; and
wherein the activator-support contains from about 2 to about 15 wt. % fluoride.

14. The process of claim 13 , further comprising a step of drying and/or a step of calcining after the contacting step.

15. The process of claim 13 , further comprising a step of calcining the silica-coated alumina prior to the contacting step.

16. The process of claim 13 , wherein a slurry of the silica-coated alumina in a solvent is contacted with the fluoriding agent.

17. The process of claim 13 , wherein the silica-coated alumina is impregnated with a solution containing the fluoriding agent and a solvent.

18. The process of claim 17 , wherein the solvent comprises water or an alcohol.

19. The process of claim 13 , wherein the fluoriding agent comprises hydrofluoric acid (HF), ammonium fluoride (NH 4 F), ammonium bifluoride (NH 4 HF 2 ), ammonium tetrafluoroborate (NH 4 BF 4 ), ammonium hexafluorosilicate ((NH 4 ) 2 SiF 6 ), ammonium hexafluorophosphate (NH 4 PF 6 ), hexafluorotitanic acid (H 2 TiF 6 ), ammonium hexafluorotitanic acid ((NH 4 ) 2 TiF 6 ), hexafluorozirconic acid (H 2 ZrF 6 ), AlF 3 , NH 4 AlF 4 , triflic acid, ammonium triflate, or any combination thereof.

20. The process of claim 13 , wherein the silica-coated alumina is calcined while being contacted with the fluoriding agent.

21. The process of claim 13 , wherein a gas stream containing the fluoriding agent fluidizes the silica-coated alumina during calcination.

22. The process of claim 13 , wherein the fluoriding agent comprises perfluorohexane, perfluorobenzene, fluoromethane, trifluoroethanol, HF, F 2 , silicon tetrafluoride (SiF 4 ), a tetrafluoroborate (BF 4 − ) compound, or any combination thereof.

23. The process of claim 13 , wherein:
the silica-coated alumina is characterized by a surface area in a range from about 250 to about 500 m 2 /g and a pore volume in a range from about 0.5 to about 1.8 mL/g;
the weight ratio of alumina to silica is in a range from about 1.2:1 to about 1.8:1; and
the activator-support contains from about 3 to about 12 wt. % fluoride.

Assignees

• Chevron Phillips Chemical Co Lp

Inventors

• Mcdaniel Max P
• Yang Qing
• Muninger Randy S
• Benham Elizabeth A
• Clear Kathy S

Classifications

• C08F210/06

  Propene · CPC title

• C08F4/65916

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

• B01J31/143

  of aluminium · CPC title

• C08F2500/17

  Viscosity · CPC title

• B01J35/0006

  Operations & Transport · mapped topic