MODIFIED DIENE-BASED POLYMER RUBBER, METHOD FOR PRODUCING THE SAME AND RUBBER COMPOSITION

Japanese Patent JP3797262

B2

PROBLEM TO BE SOLVED: To provide a modified diene-based polymer rubber in which both terminals and places at arbitrary positions (n-2) in a chain are modified, excellent in a saving property of a fuel cost and to provide a production method in which the process number is simplified and to provide a rubber composition using the polymer. SOLUTION: In the conjugated diene-based polymer rubber, both terminals and (n-2) places in the chain are modified with a compound represented by formula (1), wherein n is an integer of ≥3. The diene-based polymer rubber is obtained by polymerizing a conjugated diene monomer with an aromatic vinyl monomer in a hydrocarbon solvent in the presence of (A) mixed chemical seeds obtained by reacting an organic alkali metal compound with the compound represented by formula (1) at a ratio of 1: (n±0.7), further stirring the solvent for ≥30 min after finishing polymerization, adding the conjugated diene monomer and the aromatic vinyl monomer thereto again, carrying out polymerization, further repeatedly stirring the polymer and the solvent for ≤30 min (n-2) times after finishing polymerization.