Patent ID: 8765892

Claim:
A method for producing a conjugated diene polymer, comprising steps A and B: step A: copolymerizing monomers comprising 1,3-butadiene, styrene and a vinyl compound of formula (IV) below in a hydrocarbon solvent in the presence of an alkali metal catalyst to produce a polymer having an alkali metal originating from the catalyst at at least one terminus of the polymer chain comprising a monomer unit based on 1,3-butadiene, a monomer unit based on styrene and a monomer unit based on the vinyl compound of formula (IV): wherein X 4 , X 5 , and X 6 independently denote a group of formula (IVa) below, a hydrocarbyl group, or a substituted hydrocarbyl group, and at least one of X 4 , X 5 , and X 6 is a group of formula (IVa): wherein R 8 and R 9 independently denote a hydrocarbyl group having 1 to 6 carbon atoms, a substituted hydrocarbyl group having 1 to 6 carbon atoms, a silyl group, or a substituted silyl group, and R 8 and R 9 may be bonded so as to form, together with the nitrogen atom, a ring structure; and wherein the amount of vinyl compound of formula (IV) added, relative to the total amount of 1,3-butadiene and styrene, is at least 0.001 mmol/g but no greater than 0.1 mmol/g, and step B: reacting the resulting polymer in step A with a compound of formula (II): wherein n denotes an integer of 1 to 10, R 3 denotes a hydrogen atom, a hydrocarbyl group having 1 to 6 carbon atoms, or a substituted hydrocarbyl group having 1 to 6 carbon atoms, A 1 denotes an oxygen atom or an —NR 4 — group, wherein R 4 denotes a hydrogen atom or a hydrocarbyl group having 1 to 10 carbon atoms, and A 2 denotes a nitrogen atom- and/or oxygen atom-containing functional group.