Selective activity of metallocene-type catalyst for isotactic poly-alpha-olefin production

摘要

Provided is process for polymerizing isotactic poly- alpha -olefin comprising the steps of: A. Providing suitable catalyst system comprising metallocene-type catalyst capable of producing isotactic poly alpha -olefin; cocatalyst or catalyst activator; and, optionally, catalyst system support; B. Activating suitable catalyst system by contacting with alkyl aluminum such that the activated catalyst system is used for polymerization: 1) within a minimum of about two hours through about 72 hours of its activation for producing polymers of melt flow greater than about eight dg/min; or 2) within about six hours through about fourteen days of its activation for producing polymers of melt flow equal to or less than about eight dg/min; C. Polymerizing suitable monomer, using activated catalyst system, to obtain desired isotactic polyolefin; and D. Separating desired isotactic polyolefin.