RUBBER COMPOSITION AND TIRE COMPRISING THE SAME

This invention relates to a rubber composition which has an excellent processability but also improves a storage modulus (G') and loss tangent (tan ´) at a low temperature and further improves a wear resistance, and more particularly to a rubber composition characterized by compounding more than 1 part by mass but less than 30 parts by mass of a low-molecular weight polymer component (B) having an amount of an aromatic vinyl compound bonded of less than 30 mass% and a weight average molecular weight as converted to polystyrene of 0.2x 10 4 -8.0×10 4 and not less than 5 parts by mass of a filler (C) based on 100 parts by mass of a high-molecular weight polymer component (A) having an amount of an aromatic vinyl compound bonded of not more than 80 mass% and a weight average molecular weight as converted to polystyrene of not less than 1.5×10 5 , wherein the amount of the aromatic vinyl compound bonded (S 2 ) (mass%) in the low-molecular weight polymer component (B) and a vinyl bond content (V 2 ) (%) of a conjugated diene compound portion in the low-molecular weight polymer component (B) satisfy a relation of the equation (I): S 2 + V 2 /2 < 25.