| 摘要 |
The invention is directed to a supported olefin polymerization catalyst system comprising catalyst compound, silica support and alumoxane activator, where part of the alumoxane is present on the support and part of the alumoxane is not associated with the support, wherein the silica comprises silica particles having an average surface area of greater than about 400 m2/g, an average pore diameter of less than about 70 Angstroms, and wherein alumoxane is present on the support in an amount of less than 7 mmol Al/g silica and at least 1 wt% of alumoxane particles not associated with the support are present in the catalyst system, based upon the weight of the catalyst system. |
