Patent ID: 6362293
Filing Date: 2002-03-26
Classification: C08F,Y10S

Abstract:
A process for preparing syndiotactic polymers of vinylidene aromatic monomers comprising contacting one or more vinylidene aromatic monomers under polymerization conditions with a catalytically effective amount of a concentrated catalyst premix composition comprising:a) a metal complex corresponding to the formula: CpmMXnXâ€²p â€ƒwherein: Cp is a single &eegr;5-cyclopentadienyl or &eegr;5-substituted cyclopentadienyl group, the substituted cyclopentadienyl group being optionally also bonded to M through a substituent X; M is a metal of Group 4 or the Lanthanide Series of the Periodic Table; X in each occurrence is hydrogen, an inert anionic ligand of up to 20 nonhydrogen atoms and optionally X and Cp are joined together; Xâ€² is an inert, neutral donor ligand; m and p are independently 0 or 1; n is an integer greater than or equal to 1; and the sum of m and n is equal to the oxidation state of the metal; b) an activating cocatalyst, wherein the concentrated catalyst premix composition contains no additional solvent.