Borohydride metallocene complex of a lanthanide, catalytic system including said complex, polymerization method using same and ethylene/butadiene copolymer obtained using said method

摘要

Borohydride metallocene complex of lanthanide, preparation process, catalytic system incorporating borohydride metallocene complex, process for copolymerization of olefins employing catalytic system. The complex corresponds to one or other of formulae A and B:; where, in A, two ligands Cp₁, Cp₂, each composed of a cyclopentadienyl group, are connected to the lanthanide Ln, such as Nd, and where, in B, a ligand molecule, composed of two cyclopentadienyl groups Cp₁, Cp₂ connected to one another via a bridge P of formula MR₁R₂, M is an element from group IVa, and R₁ and R₂, which are identical or different, represent an alkyl group comprising from 1 to 20 carbon atoms, is connected to the lanthanide Ln, L is alkali metal, N is molecule of a complexing solvent, x is integral or non-integral number≧0, p is integer≧than 1 and y is integer≧0.