Polymerization catalyst and process

Claim 1

A polymerization process comprising contacting at least one aliphatic mono-olefin under polymerization conditions in the presence of a catalyst which is formed by (1) mixing together a first catalyst component comprising a metal hydrocarbyloxide compound having the formula M(OR) 2 ) where M is a metal selected from Group IIA and Group IIB of the Mendeleev Periodic Table and R is the same or different and is a hydrocarbyl group having from 1 to 20 carbon atoms and a transition metal hydrocarbyloxide compound in which the transition metal is selected from the group consisting of Group IVB and Group VB transition metals of the Mendeleev Periodic Table and wherein the hydrocarbyl group is as defined above in a molar ratio of transition metal compound to metal compound ranging from about 2:1 to about 1:2, (2) heating the first catalyst component solution formed in (1), (3) cooling the first catalyst component solution to a temperature below about 25° C. and optionally filtering the first catalyst component solution to remove any undissolved material from the cooled first catalyst component solution, (4) adding a precipitating agent comprising a second catalyst component in a molar ratio of transition metal compound to the precipitating agent within a range of about 2:1 to about 1:3 to the cooled first catalyst component solution which is at a temperature ranging from about -50° C. to about 25° C. under conditions so as to avoid a significant temperature rise in the solution and to produce a solid catalyst in the form of a slurry with the solvent, said second catalyst component comprising an organoaluminum halide represented by the formulas R Al X.sub.2 R.sub.2 Al X, and R.sub.3 Al.sub.2 X.sub.3 wherein each R in the above formulas is as defined before and each R can be the same or different, and X is a halogen atom, (5) washing and drying the solid catalyst component thus formed and contacting same with a transition metal halide ion exchange source selected from titanium tetrachloride, vanadium oxychloride (VOCl 3 ), and zirconium tetrachloride in a weight ratio of transition metal halide to said solid catalyst component ranging from about 7:1 to about 1:4, (6) separating the solid catalyst component formed in (5) and washing same, and, (7) combining the washed and dried solid catalyst component separated in (6) with a cocatalyst component comprising an organoaluminum compound.