Polymerization process for the production of polyolefin elastomers, cationic-producing catalysts for the activation of metallocene procatalysts, polyolefin elastomers with special combinations of physical properties and products made from them

摘要

PURPOSE: A polyolefin elastomer possessing a unique combination of properties, i.e., high molecular weight (Mw), high Mooney viscosity (ML1+4 at 125C), low polydispersity index (Mw/Mn), low glass transition temperature (Tg) and low hysteresis (tan delta) is provided by a polymerization process employing a particular type of metallocene catalyst, and also cation-generating cocatalyst for activating a metallocene procatalyst and products manufactured therefrom are provided. CONSTITUTION: The liquid phase polymerization process is carried out under solution or slurry conditions an in batch or continuously, for producing a polyolefin elastomer employing as the catalyst composition as an activated bridged metallocene in which the bridging group possesses at least two bulky groups. In particular, the process comprises contacting a monomer under liquid phase polymerization conditions with a catalytically effective amount of a catalyst composition comprising the product obtained by combining a metallocene catalyst containing a bridging group having at least two bulky groups and a cation-generating cocatalyst.