Processes for preparing solid metallocene-based catalyst systems
Methods for preparing metallocene-based catalyst systems containing an activator-support are disclosed. These methods can include contacting a solid metallocene compound, an activator-support, and an organoaluminum compound, resulting in catalyst systems with increased catalytic activity as compared to catalyst systems utilizing a solution of the metallocene compound.
1. A process to produce a catalyst composition, the process comprising:
(i) contacting an activator-support and a solid metallocene compound for a first period of time to form a precontacted mixture; and
(ii) contacting the precontacted mixture with an organoaluminum compound for a second period of time to produce the catalyst composition;
wherein an activity of the catalyst composition is from about 5% to about 100% greater than that of a catalyst system obtained by using a solution of the metallocene compound instead of the solid metallocene compound, under the same polymerization conditions.
2. The process of claim 1 , wherein in step (i), a slurry of the activator-support in a first diluent is contacted with a slurry of the solid metallocene compound in a second diluent.
3. The process of claim 1 , wherein in step (i), at least one of the activator-support and the solid metallocene compound is a dry solid.
4. The process of claim 1 , wherein:
the activator-support comprises a fluorided solid oxide, a sulfated solid oxide, a phosphated solid oxide, or a combination thereof; and
the 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 1 , wherein:
the first period of time is at least about 15 seconds; and
the activity of the catalyst composition is from about 5% to about 75% greater than that of a catalyst system obtained by using a solution of the metallocene compound instead of the solid metallocene compound, under the same polymerization conditions.
6. The process of claim 1 , wherein:
the organoaluminum compound comprises trimethylaluminum, triethylaluminum, tri-n-propylaluminum, tri-n-butylaluminum, triisobutylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum, diisobutylaluminum hydride, diethylaluminum ethoxide, diethylaluminum chloride, or any combination thereof; and
the activator-support comprises fluorided silica-alumina, fluorided silica-coated alumina, sulfated alumina, or a combination thereof.
7. The process of claim 1 , wherein:
a weight ratio of the solid metallocene compound to the activator-support is in a range from about 1:10 to about 1:10,000; and
a weight ratio of the activator-support to the organoaluminum compound is in a range from about 1:5 to about 1000:1.
8. A process to produce a catalyst composition, the process comprising contacting, in any order:
(a) an activator-support;
(b) a solid metallocene compound; and
(c) an organoaluminum compound;
to produce the catalyst composition;
wherein an activity of the catalyst composition is from about 5% to about 100% greater than that of a catalyst system obtained by using a solution of the metallocene compound instead of the solid metallocene compound, under the same polymerization conditions.
9. The process of claim 8 , wherein the process comprises comprising contacting a slurry of the activator-support in a first diluent, a slurry of the solid metallocene compound in a second diluent, and the organoaluminum compound.
10. The process of claim 8 , wherein the process comprises comprising contacting a slurry of the activator-support in a first diluent, a slurry of the solid metallocene compound in a second diluent, and a solution of the organoaluminum compound.
11. The process of claim 8 , wherein at least one of the activator-support and the solid metallocene compound is a dry solid.
12. The process of claim 8 , wherein:
the solid metallocene compound comprises a bridged metallocene compound; and
the activator-support comprises sulfated alumina.
13. The process of claim 8 , wherein:
the activator-support comprises a fluorided solid oxide, a sulfated solid oxide, or a combination thereof;
the organoaluminum compound comprises trimethylaluminum, triethylaluminum, tri-n-propylaluminum, tri-n-butylaluminum, triisobutylaluminum, or any combination thereof; and
the 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.
14. The process of claim 8 , wherein the activity of the catalyst composition is from about 5% to about 75% greater than that of a catalyst system obtained by using a solution of the metallocene compound instead of the solid metallocene compound, under the same polymerization conditions.
15. The process of claim 1 , wherein:
the activator-support comprises a fluorided solid oxide and/or a sulfated solid oxide; and
the solid metallocene compound comprises a bridged zirconium or hafnium based metallocene compound with a cyclopentadienyl group and a fluorenyl group, and with an alkenyl substituent.
16. The process of claim 15 , wherein the activator-support comprises fluorided silica-alumina, fluorided silica-coated alumina, sulfated alumina, or a combination thereof.
17. The process of claim 1 , wherein:
the activator-support comprises a fluorided solid oxide and/or a sulfated solid oxide; and
the solid metallocene compound comprises an unbridged zirconium based metallocene compound containing two cyclopentadienyl groups, two indenyl groups, or a cyclopentadienyl and an indenyl group.
18. The process of claim 2 , wherein the first diluent and the second diluent independently comprise propane, cyclohexane, isobutane, n-butane, n-pentane, isopentane, neopentane, n-hexane, or combinations thereof.
19. The process of claim 8 , wherein:
the activator-support comprises a fluorided solid oxide and/or a sulfated solid oxide; and
the solid metallocene compound comprises a bridged zirconium or hafnium based metallocene compound with a cyclopentadienyl group and a fluorenyl group, and with an alkenyl substituent.
20. The process of claim 19 , wherein the activator-support comprises fluorided silica-alumina, fluorided silica-coated alumina, sulfated alumina, or a combination thereof.
21. The process of claim 9 , wherein the first diluent and the second diluent independently comprise propane, cyclohexane, isobutane, n-butane, n-pentane, isopentane, neopentane, n-hexane, or combinations thereof.
22. The process of claim 13 , wherein:
the activator-support comprises fluorided silica-alumina, fluorided silica-coated alumina, sulfated alumina, or a combination thereof; and
the solid metallocene compound comprises an unbridged zirconium based metallocene compound containing a cyclopentadienyl and an indenyl group, and with an alkenyl substituent.