Organo zirconium-chromium compound, catalyst prepared therefrom and polymerization of olefins therewith
AssigneeThe Dow Chemical Company
InventorsRandall S. Shipley, Fred L. Vance, Jr.
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Abstract
Dual transition metal compounds containing zirconium and chromium are prepared by reacting a tetrahydrocarbyloxy zirconium compound such as tetraisopropoxy zirconium or a tetravalent hydrocarbyloxy zirconium halide such as triisopropoxy zirconium halide with a chromium compound such as CrO.sub.3. These compounds, as well as combinations of other soluble chromium and zirconium compounds, are useful in the polymerization of .alpha.-olefins to produce polymers having a high molecular weight and a narrow molecular weight distribution.
Claims8
As a composition of matter, the reaction product of ( 1) a zirconium compound or mixture of such compounds thereof represented by the empirical formula (RO).sub.m ZrX.sub.4-m wherein R is a monovalent hydrocarbyl group having from 1 to about 20 carbon atoms, X is a halogen, and m has a value from 0 to 4;
- with (2) an inorganic oxygen-containing chromium compound or mixture of such compounds represented by the empirical formulas CrO.sub.3 or CrO.sub.2 X.sub.2 ;
- wherein X is a halogen and wherein the mole ratio of component (2) to component (1) is of from about 0.05:1 to about 6:1.
A catalyst composition which comprises
- (A) the reaction product of
- (1) a zirconium compound, or mixture of such compounds represented by the empirical formula (RO).sub.m ZrX.sub.4-m ;
- wherein R is a monovalent hydrocarbyl group having from 1 to about 20 carbon atoms, X is a halogen and m has a value from 0 to 4;
- and
- (2) an inorganic oxygen-containing chromium compound represented by the empirical formulae CrO.sub.3 or CrO.sub.2 X.sub.2 ;
- wherein R and X are as defined above;
- and wherein the mole ratio of component (2) to component (1) is from about 0.05:1 to about 6:1;
- (B) a solid catalyst support containing magnesium;
- (C) at etrahydrocarbyloxy titanium or titanium halide compound;
- and
- (D) an organometallic activating agent;
- wherein the Mg:Cr atomic ratio is from about 1:1 to about 200:1;
- the Al:Cr atomic ratio is from about 1:1 to about 250:1, the Cr:Ti atomic ratio is from about 0.1:1 to about 50:1;
- and the excess X:Al atomic ratio is from zero to about 5:1.
Dependencies are inferred from the claim text.