| abstract |
A catalyst composition for olefin polymerization and copolymerization which contains a complex of Ti, V, Zr, or Hf with a bidentate ligand or a tridentate ligand and a cocatalyst mixture containing dialkylaluminum halide and dialkylmagnesium. The bidentate ligands are described by general formulas Z-R-Z or Z-R-W-R-Z where R is an alkylene, cycloalkylene, arylene, or alkylarylene group; W is CH2, O, S, N-R', or SiR'2 where R' is an alkyl or aryl grup; and Z is O, S, N-H, or C(=O)-O. The tridentate ligands are described by formulas Z-(R-Z)-Z or Z-(R-U)-Z where R is an alkylene or arylene group; and Z and U are different and are O, S, N-H, or C-(=O)-O. |