PROCESS FOR THE PREPARATION OF (CO) POLYMERS OF CONJUGATED DIENES IN THE PRESENCE OF A CATALYTIC SYSTEM COMPRISING A VANADIUM BIS-IMINE COMPLEX

摘要

Process for the preparation of (co) polymers of conjugated dienes comprising polymerizing at least one conjugated diene in the presence of a catalytic system comprising at least one vanadium bis-imine complex having the general formula (I) : wherein : m is 0 or 1; Z represents a -CR5R6 group wherein R5 and R6, equal to or different from each other, represent a hydrogen atom; or a C1-C20 alkyl group, preferably C1-C15, linear or branched; or a bivalent aromatic group optionally substituted; R1 and R2 equal to or different from each other, represent a hydrogen atom; or they are selected from C1-C20 alkyl groups, preferably C1-C15, linear or branched, optionally halogenated, cycloalkyl groups optionally substituted; or R1 and R2, may be optionally bound each other so as to form, together with the other atoms which they are bound to, a cycle containing from 4 to 6 carbon atoms, saturated, unsaturated, or aromatic, optionally substituted by C1-C20 alkyl groups, preferably C1-C15, linear or branched, said cycle optionally containing heteroatoms such as, for example, oxygen, sulfur, nitrogen, silicon, phosphorus, selenium; R3 and R4, equal to or different from each other, represent a hydrogen atom; or they are selected from C1-C20 alkyl groups, preferably C1-C15, linear or branched, optionally halogenated, cycloalkyl groups optionally substituted, aryl groups optionally substituted; or R2 and R4, may be optionally bound each other so as to form, together with the other atoms which they are bound to, a cycle containing from 3 to 6 carbon atoms, saturated, unsaturated, or aromatic, optionally substituted by C1-C20 alkyl groups, preferably C1-C15, linear or branched, said cycle optionally containing other heteroatoms such as, for example, oxygen, sulfur, nitrogen, silicon, phosphorus, selenium; or R1 and R3, may be optionally bound each other so as to form, together with other atoms which they are bound to, a cycle containing from 3 to 6 carbon atoms, saturated, unsaturated, or aromatic, optionally substituted by C1-C20 alkyl groups, preferably C1-C1, linear or branched, said cycle optionally containing other heteroatoms such as oxygen, sulfur, nitrogen, silicon, phosphorus, selenium; X1, X2 and X3, equal to or different from each other, represent a halogen atom such as, for example, chlorine, bromine, iodine, preferably chlorine; or they are selected from C1-C20 alkyl groups, preferably C1-C15, linear or branched, -OCOR7 groups or -OR7 groups wherein R7 is selected from C1-C20 alkyl groups, preferably C1-C15, linear or branched; Y is selected from ethers such as, for example, diethylether, tetrahydrofuran (THF), dimethoxyethane, preferably is tetrahydrofuran (THF); n is 0 or 1.