摘要 |
<p>The present invention relates to catalyst systems containing solid catalyst components comprising titanium, magnesium, halogen and an internal electron donor compound having at least one ether group and at least one ketone group; organoaluminum compounds and alkyl benzoate derivatives as external electron donors. The present invention also relates to methods of making the catalyst systems, and methods of polymerizing or copolymerizing alpha-olefins using the catalyst systems.</p> |