Processes for producing fluorided solid oxides and uses thereof in metallocene-based catalyst systems
Disclosed herein are methods for preparing fluorided solid oxides by contacting an acidic fluorine-containing compound with an inorganic base to form an aqueous mixture having a pH of at least 4, followed by contacting a solid oxide with the aqueous mixture to produce the fluorided solid oxide. Also disclosed are methods for preparing fluorided solid oxides by contacting an acidic fluorine-containing compound with a solid oxide to produce a mixture, followed by contacting the mixture with a inorganic base to produce the fluorided solid oxide at a pH of at least about 4. The fluorided solid oxide can be used as an activator component in a catalyst system for the polymerization of olefins.
1. An olefin polymerization process, the process comprising:
contacting a catalyst composition with an olefin monomer and an optional olefin comonomer in a polymerization reactor system under polymerization conditions to produce an olefin polymer; wherein the catalyst composition comprises:
a metallocene compound;
a fluorided solid oxide comprising:
a silica-coated alumina containing from about 10 to about 80 wt. % silica;
from about 0.5 to about 15 wt. % F;
from about 0.5 to about 15 wt. % Zn; and
from about 0.2 to about 1.2 wt. % B; and
optionally, a co-catalyst.
2. The process of claim 1 , wherein the fluorided solid oxide comprises:
from about 3 to about 7 wt. % F;
from about 1 to about 5 wt. % Zn; and
from about 0.3 to about 1 wt. % B.
3. The process of claim 2 , wherein the silica-coated alumina contains from about 25 to about 50 wt. % silica.
4. The process of claim 1 , wherein the fluorided solid oxide has:
a total pore volume from about 0.5 to about 2.5 mL/g;
a BET surface area from about 150 to about 700 m 2 /g; and
an average (d50) particle size from about 10 to about 100 microns.
5. The process of claim 1 , wherein the metallocene compound is an unbridged metallocene compound.
6. The process of claim 1 , wherein the metallocene compound is a bridged metallocene compound.
7. The process of claim 1 , wherein the catalyst composition comprises two or more metallocene compounds.
8. The process of claim 1 , wherein the catalyst composition is contacted with ethylene and an olefin comonomer comprising 1-butene, 1-hexene, 1-octene, or a mixture thereof.
9. The process of claim 1 , wherein the polymerization reactor system comprises a loop slurry reactor, a gas-phase reactor, a solution reactor, or a combination thereof.
10. The process of claim 1 , wherein the olefin polymer comprises an ethylene homopolymer, an ethylene/1-butene copolymer, an ethylene/1-hexene copolymer, and/or an ethylene/1-octene copolymer.
11. The process of claim 1 , wherein the catalyst composition comprises the co-catalyst.
12. The process of claim 11 , wherein:
the polymerization reactor system comprises a loop slurry reactor, a gas-phase reactor, a solution reactor, or a combination thereof; and
the olefin polymer comprises an ethylene homopolymer, an ethylene/1-butene copolymer, an ethylene/1-hexene copolymer, and/or an ethylene/1-octene copolymer.
13. The process of claim 12 , wherein the co-catalyst comprises an aluminoxane compound, an organoboron or organoborate compound, an ionizing ionic compound, an organoaluminum compound, an organozinc compound, an organomagnesium compound, an organolithium compound, or any combination thereof.
14. The process of claim 12 , wherein the co-catalyst comprises trimethylaluminum (TMA), triethylaluminum (TEA), tri-n-propylaluminum (TNPA), tri-n-butylaluminum (TNBA), triisobutylaluminum (TIBA), tri-n-hexylaluminum, tri-n-octylaluminum, or any combination thereof.
15. The process of claim 14 , wherein the fluorided solid oxide comprises:
from about 3 to about 7 wt. % F;
from about 1 to about 5 wt. % Zn; and
from about 0.3 to about 1 wt. % B.
16. The process of claim 15 , wherein the silica-coated alumina contains from about 25 to about 50 wt. % silica.
17. The process of claim 15 , wherein the metallocene compound is an unbridged metallocene compound.
18. The process of claim 15 , wherein the metallocene compound is a bridged metallocene compound.
19. The process of claim 15 , wherein the catalyst composition comprises two or more metallocene compounds.