Patent ID: 6878785

Claim:
A polymer produced using a polymerization process comprising contacting, under polymerization conditions, at least one monomer and a catalyst composition which is substantially free of aluminoxanes; wherein the catalyst composition is produced by a process comprising: (1) contacting alumina with a solution containing a zirconium tetraalkoxide, (Zr(OR) 4 ), where R is an aliphatic radical containing one to twelve carbons, to produce a zirconium-containing alumina having from 1 to 10 weight percent zirconium based on the weight of the zirconium-containing alumina before calcining; (2) calcining the zirconium-containing alumina at a temperature within a range of 350 to 600° C. for 3 to 20 hours to produce a calcined composition; (3) contacting the calcined composition with carbon tetrachloride in an amount equal to 0.05 to 1 times the weight of the alumina before calcining for 10 minutes to 30 minutes to produce a chlorided, zirconium-containing alumina; (4) combining the chlorided, zirconium-containing alumina and bis(n-butylcyclopentadienyl) zirconium dichloride at a temperature within a range of 15° C. to 80° C. for about 1 minute to 1 hour to produce a mixture; and (5) combining the mixture with triethylaluminum to produce the catalyst composition.