RUBBER COMPOSITION AND PNEUMATIC TIRE COMPRISING THE SAME

摘要

Disclosed is a rubber composition comprising: 100 parts by mass of a rubber component (A) comprising at least one member selected from the group consisting of a natural rubber, a polyisoprene rubber, a styrene-butadiene copolymer rubber, a polybutadiene rubber and an isobutyrene isoprene rubber; and 1 to 60 parts by mass of a low-molecular-weight conjugated diene polymer (B) having a weight average molecular weight of 10,000 to 200,000 in terms of polystyrene as measured by gel permeation chromatography and having an amount of vinyl bonds in the conjugated diene compound moiety of 40% or more, wherein the rubber component (A) comprises a natural rubber and/or a polyisoprene rubber, and the percentage of a styrene unit in the low-molecular-weight conjugated diene polymer (B) is less than 5 mass%. The rubber composition is excellent in workability during production process and heat resistance, and has a high storage modulus (G') and a low loss tangent value (tand).