Method for polymerizing olefins, metallocene catalysts therefor and cocatalysts for activating metallocene procatalysts

摘要

A polyolefin elastomer possessing a unique combination of properties, i.e., high molecular weight (Mw), high Mooney viscosity (ML1+4 at 125° C.), low polydispersity index (Mw/Mn) and low glass transition temperature (Tg), is obtained by a polymerization process employing a particular type of a metallocene catalyst. The polyolefin elastomer is useful for manufacturing a variety of products including rubber articles such as hoses, belts and moldings, polymer blends containing one or more other hydrocarbon polymers and lubricating oils in which the elastomer functions as a viscosity modifier. Also disclosed is a cocatalyst for activating the metallocene procatalyst employing a specific molar ratio of the components of the cocatalyst to the transition metal of the procatalyst.