Claims
- 1. A polymerization process comprising contacting at least one alpha-olefin monomer under polymerization conditions with a catalyst system comprising:
- (1) a catalyst A comprising an organometal compound and a transition metal compound,
- wherein said organometal compound is selected from the group consisting of alkali metal alkyls and alkaline earth metal alkyls and mixtures thereof, and
- wherein said transition metal compound is selected from the group consisting of compounds having the formula TiX.sub.4, wherein each X is individually selected from the group consisting of halogen, alkyl, alkoxy, and aryl radicals; and
- (2) a catalyst B comprising a rare earth complex having a formula Cp.sub.n MX.sub.4-n.M'L.sub.x, wherein Cp is cyclopentadienyl or cyclopentadienyl substituted with an alkyl or alkyl silyl radical, M is yttrium, scandium or a rare earth metal having an atomic number in the range of 57 to 71, M' is an alkali metal, L is a suitable electron donor ligand, X is a halogen, n is 1 or 2, and x is a number corresponding to the value needed to form a stable complex.
- 2. A process according to claim 1 wherein said polymerization conditions comprise a temperature of about 0.degree. to about 200.degree. C. and a pressure up to 300 atmospheres.
- 3. A process according to claim 1 wherein said catalyst A further comprises a metal halide selected from the group consisting of yttrium, scandium, and rare earth metal halides having atomic numbers 57-71 inclusive.
- 4. A process according to claim 1 wherein said catalyst B further comprises a metal alkyl selected from the group consisting of alkali metal alkyls, alkaline earth metal alkyls, and mixtures thereof.
- 5. A process according to claim 1 wherein said catalyst B further comprises a hydrocarbyl aluminum compound.
- 6. A process according to claim 1 wherein said organometal compound in catalyst A is selected from the group consisting of lithium alkyls and magnesium alkyls containing 2 to 6 carbon atoms.
- 7. A process according to claim 1 wherein said transition metal compound in catalyst A is a titanium tetrahalide.
- 8. A process according to claim 1 wherein Cp in catalyst B is pentamethylcyclopentadienyl;
- wherein M is selected from the group consisting of neodymium, samarium, and ytterbium;
- wherein M' is selected from from the group consisting of lithium, sodium, and potassium; and
- wherein L is selected from the group consisting of tetrahydrofuran, diethylether, and N,N,N',N'-tetramethylethylene diamine.
- 9. A process according to claim 3 wherein said metal halide in catalyst A is selected from the halides of neodymium, praseodymium, lanthanum, yttrium, and mixtures thereof.
- 10. A process according to claim 4 wherein said metal alkyl in catalyst B is selected from the group consisting of alkyl lithium and alkyl magnesium.
- 11. A polymerization process comprising contacting at least one alpha-olefin monomer under polymerization conditions with a catalyst system comprising:
- (1) a catalyst A comprising neodymium trichloride, n-butyl lithium, and titanium tetrachloride;
- (2) a catalyst B comprising (Me.sub.5 C.sub.5)NdCl.sub.2.Li(Et.sub.2 O).sub.2 and a metal alkyl selected from the group consisting of butyl lithium, dibutyl magnesium, diethylaluminum hydride, and mixtures thereof.
- 12. A process according to claim 11 wherein said alpha-olefin monomer comprises ethylene.
- 13. A process according to claim 11 wherein said polymerization conditions comprise a temperature of 25.degree. C. to 100.degree. C. and a pressure of atmospheric up to 50 atmospheres.
- 14. A process according to claim 11 wherein said polymerization is conducted in the presence of hydrogen in an amount sufficient to control the molecular weight distribution of the polymer.
Parent Case Info
This application is a divisional of copending application Ser. No. 07/955,606, filed Oct. 1, 1992 now U.S. Pat. No. 5,260,244, which is a division of application Ser. No. 07,810,581, Dec. 19, 1991, U.S. Pat. No. 5,182,244.
US Referenced Citations (10)
Non-Patent Literature Citations (1)
Entry |
"Pentamethylcyclopentadienyl Derivatives of the Trivalent Lanthanide Elements Neodymium, Samarium, and Ytterbium", T. Don Tilley and Richard Andersen, Inorg. Chem. vol. 20, pp. 3267-3270, 1981 (No month available). |
Divisions (2)
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Number |
Date |
Country |
Parent |
955606 |
Oct 1992 |
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Parent |
810581 |
Dec 1991 |
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