Patent ID: 6255417
Filing Date: 2001-07-03
Classification: C08F,Y10S

Abstract:
An improved process of preparing an olefinic polymer of the type in which an olefinic monomer is polymerized alone or with a comonomer in a hydrocarbon solvent using a metallocene catalyst of formula (I) in the presence of a cocatalyst; wherein the improvement comprises: preparing the olefinic polymer in an aliphatic hydrocarbon solvent selected from the group consisting of pentane, hexane and heptane, using a modified metallocene catalyst which is obtained by introducing at least one linear C.sub.5-20 alkyl substituent into the alkylene bridge of the metallocene catalyst of formula (I):L.sup.1 L.sup.2 MX.sub.2 (I)wherein,M is Ti, Zr or Hf;X is a halogen or a C.sub.1-3 alkyl group; andL.sup.1 and L.sup.2 are each a .pi.-ligand selected from the group consisting of cyclopentadienyl, indenyl, fluorenyl and derivatives thereof, and are linked together by a C.sub.1-4 alkylene bridge optionally further substituted with a C.sub.1-3 hydrocarbyl group.