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 catalyst composition comprising:
(i) a precontacted mixture comprising:
an activator-support, and
a solid metallocene compound; and
(ii) an organoaluminum compound;
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 composition of claim 1 , wherein:
the activator-support comprises a fluorided solid oxide, a sulfated solid oxide, a phosphated alumina, 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 a bridged zirconium or hafnium based metallocene compound with a cyclopentadienyl group and a fluorenyl group.
3. The composition of claim 1 , 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.
4. The composition of claim 1 , wherein the precontacted mixture comprises a hydrocarbon diluent that does not dissolve the solid metallocene compound.
5. The composition of claim 1 , wherein the activator-support comprises a fluorided solid oxide and/or a sulfated solid oxide.
6. The composition of claim 5 , wherein 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.
7. The composition of claim 5 , wherein 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.
8. The composition of claim 1 , wherein the activator-support comprises fluorided silica-alumina, fluorided silica-coated alumina, sulfated alumina, or a combination thereof.
9. The composition of claim 8 , wherein the organoaluminum compound comprises trimethylaluminum, triethylaluminum, tri-n-propylaluminum, tri-n-butylaluminum, triisobutyl aluminum, tri-n-hexylaluminum, tri-n-octylaluminum, diisobutylaluminum hydride, diethylaluminum ethoxide, diethylaluminum chloride, or any combination thereof.
10. The composition 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.
11. A catalyst composition comprising:
(a) an activator-support;
(b) a solid metallocene compound; and
(c) an organoaluminum compound;
wherein an activity of the catalyst composition is from about 5% to about 150% 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.
12. The composition of claim 11 , wherein the activity of the catalyst composition is from about 5% to about 50% 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.
13. The composition of claim 11 , wherein the catalyst composition comprises a hydrocarbon diluent that does not dissolve the solid metallocene compound.
14. The composition of claim 11 , wherein the activator-support comprises a fluorided solid oxide and/or a sulfated solid oxide.
15. The composition of claim 14 , wherein 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.
16. The composition of claim 14 , wherein 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.
17. The composition of claim 11 , wherein the activator-support comprises fluorided silica-alumina, fluorided silica-coated alumina, sulfated alumina, or a combination thereof.
18. The composition of claim 17 , 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.
19. The composition of claim 11 , 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.
20. The composition of claim 11 , wherein:
the solid metallocene compound comprises a bridged metallocene compound;
the activator-support comprises sulfated alumina; and
the organoaluminum compound comprises trimethylaluminum, triethylaluminum, tri-n-propylaluminum, tri-n-butylaluminum, triisobutylaluminum, or any combination thereof.