Patent ID: 7884163

Claim:
An olefin polymerization process, the process comprising: contacting a catalyst composition with at least one olefin monomer and optionally at least one olefin comonomer under polymerization conditions to produce an olefin polymer, wherein the catalyst composition comprises at least one transition metal compound comprising titanium, zirconium, or hafnium, and at least one activator-support, wherein: the at least one activator-support comprises at least one silica-coated alumina treated with at least one electron-withdrawing anion, wherein: the at least one silica-coated alumina has a weight ratio of alumina to silica in a range from about 1:1 to about 100:1, and the at least one electron-withdrawing anion comprises fluoride, chloride, bromide, phosphate, triflate, bisulfate, sulfate, or any combination thereof.