PROCESS FOR PRODUCTION OF MODIFIED CONJUGATED DIENE POLYMERS, MODIFIED CONJUGATED DIENE POLYMERS PRODUCED BY THE PROCESS, RUBBER COMPOSITIONS, AND TIRES

摘要

The invention provides a process for producing a modified conjugated diene based polymer which attains favorable interaction between a rubber component and carbon black and/or silica, thereby improving dispersibility of the fillers, and which exhibits excellent properties such as heat-buildup-suppressing performance, fracture characteristics, and wear resistance; a modified conjugated diene based polymer produced through the process; a rubber composition containing the diene polymer; and a tire produced from the rubber composition and exhibiting the above properties. The process for producing a modified conjugated diene based polymer includes a step (a) of reacting a silicon compound with a conjugated diene based polymer having an active end so that the reaction takes place at the active end, the silicon compound having a protected primary amino group in the molecule thereof and a bi-functional silicon atom to which a hydrocarbyloxy group and a reactive group are bonded, to thereby modify the active end, and a step (b) of performing condensation reaction which involves the compound having a bi-functional silicon atom, in the presence of a titanium compound serving as a titanium-based condensation-accelerating agent.