| abstract |
An improved process of preparing a 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 using a modified metallocene catalyst which is obtained by introducing at least one C5-20 alkyl substituent into the pi-ligand, the alkylene bridge or silicon bridge of the metallocene catalyst of formula (I):wherein,M is Ti, Zr or Hf;X is a halogen, or a C1-3 alkyl group; andL1 and L2 are each a pi-ligand selected from the group consisting of cyclopentadienyl, indenyl, fluorenyl and derivatives thereof, and are optionally linked together by a C1-4 alkylene bridge optionally substituted with a C1-3 hydrocarbyl group or by a silicon bridge optionally substituted with a C1-3 hydrocarbyl group. |