CATALYTIC SYSTEMS MADE OF A COMPLEX OF RARE EARTHS FOR STEREOSPECIFIC POLYMERISATION OF CONJUGATED DIENES

摘要

The present invention relates to a multi-component catalytic system which can be used for 1,4-cis stereospecific polymerisation of conjugated dienes. The system is made up of (i) a rare earth complex with formula (II) Ln(A)3(B)n, in which Ln is a rare earth metal, A is a ligand, B is a Lewis base or a molecule of solvent and n is a number from 0 to 3; (ii) an alkylating agent, (iii) a compound made up of an aromatic ring having at least two hetero atoms, selected from the elements O, N, S, P, and having the formula (III), wherein the R groupings each designate hydrogen, an alkyl radical possibly comprising one or more hetero atoms (N, O, P, S, Si) or one or more halogen atoms, a halogen atom, a grouping made up of one or more hetero atoms (N, O, P, S, Si); x and y are integers from 0 to 6; D is a grouping having a chemical function in which one of the atoms has a non-binding doublet; L being an atom from the first column of the periodic table.