Catalysts for olefin polymerization or oligomerization
View Patent ↗Novel iron and cobalt complexes of certain novel tricyclic ligands containing a “pyridine” ring and substituted with two imino groups are polymerization and/or oligomerization catalysts for olefins, especially ethylene. Depending on the exact structure of the ligand, and polymerization process conditions, products ranging from α-olefins to high polymers may be produced. The polymers, especially polyethylenes, are useful for films and as molding resins.
1. A process for the polymerization or oligomerization of olefins, comprising, contacting one or more olefins of the formula:
R 1 CH═CH 2 (I),
with an iron or cobalt complex of a diimine of a diketone of the formula:
wherein:
(i) R 1 is hydrogen or n-alkyl;
(ii) m and n are each independently an integer of 1 to 5;
(iii) each R 2 and R 3 is independently hydrogen, hydrocarbyl, substituted hydrocarbyl, or a functional group; and
(iv) R 4 is hydrogen, hydrocarbyl, substituted hydrocarbyl, or a functional group.
2. The process as recited in claim 1 , wherein m and n are both 2 or 3, R 4 is hydrogen, and wherein R 2 and R 3 are hydrogen.
3. The process as recited in claim 1 , wherein (II) has the formula:
wherein R 5 and R 6 are hydrocarbyl or substituted hydrocarbyl.
4. The process as recited in claim 3 , wherein R 5 and R 6 are each independently aryl or substituted aryl.
5. The process as recited in claim 4 , wherein R 5 and R 6 are each independently phenyl, substituted phenyl, 1-pyrrolyl or substituted 1-pyrrolyl.
6. The process as recited in claim 1 , wherein said olefin comprises ethylene.
7. The process as recited in claim 6 , wherein the olefin is ethylene only.
8. The process as recited in claim 1 , wherein a polymer having a weight average molecular weight of about 10,000 Daltons or more is produced.
9. The process as recited in claim 1 , wherein linear alpha-olefins are produced.
10. The process as recited in claim 3 , wherein R 5 and R 6 are each independently aryl or substituted aryl, m and n are both 2 or 3, R 4 is hydrogen, every R 2 and R 3 is hydrogen, and said olefin comprises ethylene, and said complex is an iron complex.