Olefin polymerization catalyst on plasma-contacted support
View Patent ↗A method for preparing an olefin polymerization catalyst is disclosed. An inorganic oxide is contacted with plasma and a transition metal compound is supported on the contacted inorganic oxide. The method is fast, convenient, and avoids many of the problems associated with known methods of supporting catalysts.
1. A method which comprises preparing an olefin polymerization catalyst by contacting an inorganic oxide with plasma and supporting a Group 3 to 10 transition or lanthanide metal compound on the plasma-contacted inorganic oxide wherein the transition metal compound contains a polymerization-stable anionic ligand.
2. The method of claim 1 wherein the plasma is generated with electromagnetic radiation having a frequency from about 0.01 to about 10 6 MHz or combinations thereof.
3. The method of claim 2 wherein the frequency is from about 300 to about 10 5 MHz.
4. The method of claim 3 wherein the frequency is from about 10 3 to about 10 4 MHz.
5. The method of claim 2 wherein a combination of electromagnetic radiation frequencies is used.
6. The method of claim 2 wherein the plasma is generated by irradiating a carrier gas selected from the group consisting of oxygen, helium, neon, argon, xenon, nitrogen, air, and mixtures thereof.
7. The method of claim 6 wherein the carrier gas is oxygen.
8. The method of claim 1 wherein the inorganic oxide is contacted with plasma at a temperature below 200°.
9. The method of claim 1 wherein the inorganic oxide is contacted with plasma for a time from about 1 minute to about 200 minutes.
10. The method of claim 9 wherein the time is from about 2 minutes to about 50 minutes.
11. The method of claim 1 wherein the inorganic oxide is selected from the group consisting of silica, alumina, and aluminosilicates.
12. The method of claim 11 wherein the inorganic oxide is silica.
13. The method of claim 12 wherein the silica has an average particle size of from about 1 to about 500 microns.
14. The method of claim 13 wherein the silica has an average particle size of from about 2 to about 30 microns.
15. The method of claim 1 wherein the polymerization-stable anionic ligand is selected from the group consisting of substituted or unsubstituted cyclopentadienyl, indenyl, fluorenyl, boraaryl, pyrrolyl, indolyl, indenoindolyl, quinolinoxy, pyridinoxy, and azaborolinyl.
16. The method of claim 15 wherein the polymerization-stable anionic ligand is an indenoindolyl ligand.
17. A process which comprises polymerizing an olefin in the presence of a catalyst made by the method of claim 1 .
18. The process of claim 17 wherein the olefin is polymerized in the presence of the catalyst and an activator selected from the group consisting of alumoxanes, organoboranes, and ionic borates.
19. The process of claim 18 wherein the olefin is selected from the group consisting of ethylene, propylene, 1-butene, 1-hexene, 1-octene, and mixtures thereof.