Methods for restoring metallocene solids exposed to air

Patent metadata

Field	Value
Publication number	US-10550208-B2
Application number	US-201916249975-A
Country	US
Kind code	B2
Filing date	Jan 17, 2019
Priority date	Mar 17, 2017
Publication date	Feb 4, 2020
Grant date	Feb 4, 2020

Abstract

Methods for treating solid metallocene compounds that are exposed to air are disclosed. These methods include a step of contacting the exposed solid metallocene compound with a purging gas stream containing an inert gas, and optionally, subjecting the exposed solid metallocene compound to a sub-atmospheric pressure.

First claim

We claim:

1. A process comprising:
(i) in any order, contacting an exposed solid metallocene compound with a purging gas stream comprising an inert gas, and subjecting the exposed solid metallocene compound to a sub-atmospheric pressure, to form a treated solid metallocene compound;
(ii) forming a slurry of the treated solid metallocene compound in a diluent or a solution of the treated solid metallocene compound in a solvent; and
(iii) combining the slurry or the solution, an activator, and optionally, a co-catalyst, to produce a catalyst composition.

2. The process of claim 1 , wherein:
the purging gas stream comprises nitrogen, less than 25 ppmw of water, and less than 25 ppmw of oxygen-containing compounds; and
subjecting the exposed solid metallocene compound to a sub-atmospheric pressure comprises a pressure in a range from about 100 torr to about 0.01 torr, and a temperature in a range from about 10° C. to about 75° C.

3. The process of claim 1 , wherein the solution, the activator, and an organoaluminum co-catalyst are combined to produce the catalyst composition.

4. The process of claim 3 , wherein the treated solid metallocene compound comprises a bridged zirconium or hafnium based metallocene compound with a cyclopentadienyl group and a fluorenyl group.

5. The process of claim 3 , wherein the treated solid metallocene compound comprises an unbridged zirconium or hafnium based metallocene compound containing two cyclopentadienyl groups, two indenyl groups, or a cyclopentadienyl and an indenyl group.

6. The process of claim 1 , wherein a 1 mg/mL solution of the treated solid metallocene compound of step (i) in toluene has a moisture content of less than 10 ppmw.

7. The process of claim 6 , wherein the activator comprises an activator-support comprising a fluorided solid oxide, a sulfated solid oxide, a phosphated solid oxide, or a combination thereof.

8. The process of claim 6 , wherein the activator comprises an aluminoxane compound.

9. The process of claim 1 , further comprising a step of contacting the catalyst composition with an olefin monomer and an optional olefin comonomer in a polymerization reactor system under polymerization conditions to produce an olefin polymer.

10. The process of claim 9 , wherein:
the polymerization reactor system comprises a slurry reactor, a gas-phase reactor, a solution reactor, or a combination thereof; and
the catalyst composition is contacted with ethylene and an olefin comonomer comprising 1-butene, 1-hexene, 1-octene, or a mixture thereof.

11. The process of claim 10 , wherein:
the purging gas stream comprises nitrogen, less than 25 ppmw of water, and less than 25 ppmw of oxygen-containing compounds;
subjecting the exposed solid metallocene compound to a sub-atmospheric pressure comprises a pressure in a range from about 100 torr to about 0.01 torr, and a temperature in a range from about 10° C. to about 75° C.;
a 1 mg/mL solution of the treated solid metallocene compound of step (i) in toluene has a moisture content of less than 5 ppmw; and
the solution or the slurry, the activator, and an organoaluminum co-catalyst are combined to produce the catalyst composition.

12. The process of claim 11 , wherein the treated solid metallocene compound comprises titanium, zirconium, hafnium, or a combination thereof.

13. The process of claim 11 , wherein the treated solid metallocene compound comprises:
a bridged zirconium or hafnium based metallocene compound with a cyclopentadienyl group and a fluorenyl group; or
an unbridged zirconium or hafnium based metallocene compound containing two cyclopentadienyl groups, two indenyl groups, or a cyclopentadienyl and an indenyl group.

14. A process comprising:
(a) contacting an exposed solid metallocene compound with a purging gas stream comprising an inert gas to form a treated solid metallocene compound;
(b) forming a slurry of the treated solid metallocene compound in a diluent or a solution of the treated solid metallocene compound in a solvent; and
(c) combining the slurry or the solution, an activator, and optionally, a co-catalyst, to produce a catalyst composition.

15. The process of claim 14 , wherein:
the purging gas stream comprises nitrogen, less than 25 ppmw of water, and less than 25 ppmw of oxygen-containing compounds;
step (a) comprises fluidizing the exposed solid metallocene compound with the purging gas stream; and
the treated solid metallocene compound comprises titanium, zirconium, hafnium, or a combination thereof.

16. The process of claim 15 , wherein the treated solid metallocene compound comprises:
a bridged zirconium or hafnium based metallocene compound with a cyclopentadienyl group and a fluorenyl group; or
an unbridged zirconium or hafnium based metallocene compound containing two cyclopentadienyl groups, two indenyl groups, or a cyclopentadienyl and an indenyl group.

17. The process of claim 15 , wherein a 1 mg/mL solution of the treated solid metallocene compound of step (a) in toluene has a moisture content of less than 5 ppmw.

18. The process of claim 14 , further comprising a step of contacting the catalyst composition with an olefin monomer and an optional olefin comonomer in a polymerization reactor system under polymerization conditions to produce an olefin polymer.

19. The process of claim 18 , wherein:
the solution, the activator, and an organoaluminum co-catalyst are combined to produce the catalyst composition;
the polymerization reactor system comprises a slurry reactor, a gas-phase reactor, a solution reactor, or a combination thereof; and
the olefin monomer comprises ethylene.

20. The process of claim 19 , wherein:
a 1 mg/mL solution of the treated solid metallocene compound of step (a) in toluene has a moisture content of less than 5 ppmw;
the treated solid metallocene compound comprises titanium, zirconium, hafnium, or a combination thereof; and
the catalyst composition is contacted with ethylene and an olefin comonomer comprising a C 3 -C 10 alpha-olefin.

Assignees

• Chevron Phillips Chemical Co Lp

Inventors

• Yang Qing
• Crain Tony R
• Rajaendran George R

Classifications

• C08F4/65916

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

• C08F4/6592

  containing at least one cyclopentadienyl ring, condensed or not, e.g. an indenyl or a fluorenyl ring · CPC title

• C08F4/65927

  two cyclopentadienyl rings being mutually bridged · CPC title

• C08F4/65912

  in combination with an organoaluminium compound · CPC title

• C08F4/63925

  two cyclopentadienyl rings being mutually non-bridged · CPC title