| 摘要 |
The present invention is directed to a coordinating catalyst system comprising at least one metallocene or constrained geometry pre-catalyst transition metal compound, (e.g., di-(n-butylcyclopentadienyl)zirconium dichloride), at least one support-activator (e.g., spray dried silica/clay agglomerate), and optionally at least one organometallic compound (e.g., triisobutyl aluminum), in controlled amounts, and methods for preparing the same. The resulting catalyst system exhibits enhanced activity for polymerizing olefins and yields polymer having very good morphology. The support-activator is a layered material having a negative charge on its interlaminar surfaces and is sufficiently Lewis acidic to activate the transition metal compound for olefin polymerization.
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