| abstract |
PROBLEM TO BE SOLVED: To provide a high 1,4-cis bond content, a low 1,2-vinyl bond content, a narrow molecular weight distribution, a specific functional group in a molecule, and dispersibility with silica. A conjugated diene-based polymer is obtained which is excellent in abrasion resistance, mechanical strength and low heat build-up by blending silica. The cis-1,4-bond content is 85% or more, The 1,2-vinyl bond content is 2.0% or less, and the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) (Mw / M A conjugated diene-based polymer having n) of 5 or less and having at least one kind of functional group selected from the group consisting of an epoxy group and a hydroxyl group, and a rubber composition obtained by blending silica with the conjugated diene-based polymer. |