| abstract |
A process for producing a modified conjugated diene polymer which comprises the steps of (I) polymerizing a conjugated diene in an inert organic solvent in the presence of a catalyst comprising (a) a lanthanum series rare earth element compound, (b) an organoaluminum compound represented by the general formula, AlR1R2R3 (wherein R1, R2 and R3 which may be same or different, are hydrogen atoms or hydrocarbon groups of 1 to 8 carbon atoms and at least one of R1, R2 and R3 is said hydrocarbon group) and, if necessary, at least one member selected from the group consisting of (c) a Lewis acid and/or (d) a Lewis base, and then (II) modifying the resulting reactive polymer with a modifying compound of the general formula, R4nMX4-n (wherein R4 is an alkyl group of 1 to 20 carbon atoms or an aryl group, M is a tin atom, X is a halogen atom, and n is an integer of 1 to 3). |