Patent ID: 9695302
Date: 2017-07-04
CPC Classifications: B60C,C08K,C08L

Claim:
1. A rubber composition for studless winter tires, comprising: a rubber component that comprises natural rubber and butadiene rubber; an aromatic oil; silica; and carbon black, wherein a combined amount of the natural rubber and the butadiene rubber is 30 mass % or more based on 100 mass % of the rubber component; an amount of the butadiene rubber is 20-60 mass % based on 100 mass % of the rubber component; an amount of the natural rubber is 40-80 mass % based on 100 mass % of the rubber component; an amount of the aromatic oil is 12 to 85 parts by mass relative to 100 parts by mass of the rubber component; a silica content is 45 mass % or more based on 100 mass % in total of the silica and the carbon black; the silica comprises one or more kinds of silica (1) with a nitrogen adsorption specific surface area of 100 m a combined amount of the silica (1) and the silica (2) is 30 to 150 parts by mass relative to 100 parts by mass of the rubber component; and an amount of the silica (1) and an amount of the silica (2) satisfy the following relation: