摘要 |
This invention provides a rubber composition being excellent in the workability during production and the heat resistance and high in the storage elastic modulus (G') and small in the loss tangent (tan ´), which is formed by compounding 1-60 parts by mass of a low-molecular weight conjugated diene-based polymer (B) having a weight average molecular weight as measured through a gel permeation chromatography and converted to polystyrene of 10,000-200,000 and a vinyl bond content in a conjugated diene compound portion of not less than 40% based on 100 parts by mass of a rubber component (A) comprised of at least one selected from the group consisting of natural rubber, polyisoprene rubber, styrene-butadiene copolymer rubber, polybutadiene rubber and isobutylene isoprene rubber, wherein the rubber component (A) comprises natural rubber and/or polyisoprene rubber and a proportion of styrene units in total of the low-molecular weight conjugated diene-based polymer (B) is less than 5% by mass. |