LANTHANIDE COMPLEXES EFFICIENT IN THE POLYMERIZATION OF CONJUGATED DIENES AND A PROCESS FOR THE POLYMERIZATION OF C4-C20 CONJUGATED DIENES

摘要

This invention relates to lanthanide complexes efficient in the polymerization of conjugated dienes, obtained by reacting LnX3 with at least one Lithium compound selected from: (i) Li(A), the molar ratio Li(A)/LnX3 being from 1.5 to 2.5; (ii)LiLn(A)4' the molar ratio between LiLn(A)4 and LnX3 being from 0.5 to 1.5; wherein Ln is selected from any of the Lanthanides; X is selected from halides, carboxylates, alcoholates, -N(Rx) (Ry) wherein Rx and Ry, the same or different, are CI-Cs alkyl radicals; A is an allyl radical having the general formula R2 R3 R4 , I I (R1-C=C=C-R5) wherein R1, R2, R3, and R5, the same or different, are selected from hydrogen and C1-C1O alkyl radicals. This invention also relates to a process for the polymerization of C4-C20 conjugated dienes.