| abstract |
A novel metallocene catalyst for the production of olefin homo- or copolymers is of the formula: Ak-N=M(X)m(Cp)n; where Ak is a C1-12 alkyl group, arylalkyl group, optionally substitued with a C1-12 haloalkyl, halogen or a C1-12 alkoxy group; M is a transition metal of groups 3-10, preferably Groups 3-7, more preferably groups 4-6, and most preferably groups 4-5, of the Periodic Table; Cp is a cyclopentadienyl group-containing ligand; X is a halogen, preferably Cl or Br, C1-20 alkoxy, C1-20 siloxy, N(R)2, a hydrocarbyl group of up to about 12 carbon atoms, hydrogen, or another monoanionic ligand, or mixtures thereof; preferably X is halogen, methoxy, ethoxy or siloxy (R1)3SiO-, where R1 is C1-20 alkyl and R is C1-12 alkyl; and m + n equals the remaining valence of the metal imido group; wherein Cp and the imido group may be bridged to each other, and Cp may also be a borabenzyl, pyrrolyl, or azaboralinyl or homologous ligand. An alumoxane or boron-containing cocatalyst may be used. |