Process and catalyst for producing isotactic polyolefins

摘要

This invention is for a metallocene catalyst component comprising a bridged metallocene in which the two substituted indenyl rings are complexed to a metal hydrocarbyl or metal halide. This metallocene catalyst component is useful for polymerizing olefins having three or more carbon atoms to produce a polymer with a isotactic stereochemical configuration. The catalyst component is a stereorigid metallocene described by the formula:wherein (CpR2C4R4) and (CpR2C4R4) are substituted indenyl rings; each R and R' is a hydrogen or a hydrocarbyl radical having 1-20 carbon atoms; R'' is a structural bridge between the two indenyl rings imparting stereorigidity to the indenyl rings; Me is a transition metal; and each is a hydrocarbyl radical or is a halogen. Further, one R and R' is a hydrocarbyl radical having 1-20 carbon atoms in a proximal position adjacent to the bridgehead carbon of the indenyl rings. The invention also includes a process of preparing isotactic polyolefins that comprises the use of one or more of the disclosed catalyst components and also a process for preparing the catalyst components.