Olefin polymerization catalyst

Claim 1

A method of preparing catalysts for polymerization of alpha-olefins comprising contacting, in substantial absence of proton donors, a soluble magnesium compound of the general formula Mg(OSiR.sup.1 R.sup.2 R.sup.3).sub.2 with a titanium alkoxide of the formula Ti(OR 4 ) 4 in combination with at least one transition metal alkoxide having a general formula selected from the group consisting of (a) M 1 (OR 4 ) 4 wherein M 1 is at least one metal selected from the group consisting of zirconium, vanadium and hafnium, (b) M 2 O(OR 4 ) 3 wherein M 2 is vanadium, (c) [M 3 (OR 4 ) 5 ] 2 where M 3 is at least one material selected from the group consisting of niobium and tantalum, (d) M 4 O 2 (OR 4 ) 2 and M 4 2 O 3 (OR 4 ) 2 wherein M 4 is chromium, and (e) at least one material selected from the group consisting of tungsten alkoxides and molybdenum alkoxides, in a sauturated aliphatic hydrocarbon solvent to form a solution, then forming a precipitate by chlorinating the solution in the substantial absence of free oxygen and recovering the precipitate for use as a catalyst, wherein each of R 1 , R 2 and R 3 is, independently, alkyl groups or alkoxy groups containing from 1 to about 20 carbon atoms or aryl groups, aryloxy groups, cycloalkoxy groups or cycloalkyl groups containing from 6 to 14 carbon atoms, and each R 4 is, independently, alkyl groups or etherically substituted alkyl groups containing from 1 to 20 carbon atoms, aryl groups, cycloalkyl groups or etherically substituted aryl groups or cycloalkyl groups containing from 6 to 14 carbon atoms.

Claim 2

A method of preparing catalysts for polymerization of alpha-olefins comprising contacting, in substantial absence of proton donors, a soluble magnesium compound of the general formula Mg(OSiR.sup.1 R.sup.2 R.sup.3).sub.2 with a titanium alkoxide of the formula Ti(OR 4 ) 4 in combination with at least one transition metal alkoxide having a general formula selected from the group consisting of (a) M 1 (OR 4 ) 4 wherein M 1 is at least one metal selected from the group consisting of zirconium, vanadium and hafnium, (b) M 2 O(OR 4 ) 3 wherein M 2 is vanadium, (c) [M 3 (OR 4 ) 5 ] 2 where M 3 is at least one material selected from the group consisting of niobium and tantalum, (d) M 4 O 2 (OR 4 ) 2 and M 4 2 O 3 (OR 4 ) 2 wherein M 4 is chromium, and (e) at least one material selected from the group consisting of tungsten alkoxides and molybdenum alkoxides, in a sauturated aliphatic hydrocarbon solvent to form a solution, then forming a precipitate by chlorinating the solution in the substantial absence of free oxygen and recovering the precipitate for use as a catalyst, wherein each of R 1 , R 2 and R 3 is, independently, alkyl groups or alkoxy groups containing from 1 to about 20 carbon atoms or aryl groups, aryloxy groups, cycloalkoxy groups or cycloalkyl groups containing from 6 to 14 carbon atoms, and each R 4 is, independently, alkyl groups or etherically substituted alkyl groups containing from 1 to 20 carbon atoms, aryl groups, cycloalkyl groups or etherically substituted aryl groups or cycloalkyl groups containing from 6 to 14 carbon atoms.