| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for preparing a rubber composition, by which rubber strength, low fuel consumption properties and wear resistance can be improved while excellent wet grip performance is kept.SOLUTION: There is provided a method for preparing a rubber composition which contains a rubber component, carbon black of 20-60 parts mass based on 100 parts mass of the rubber component and an amphoteric compound having acidic and basic functional groups. The method comprises: a first mixing step of kneading natural rubber of the amount of ≥50 mass% of 100 mass% rubber component, the carbon black of the amount of ≥50 mass% of 100 mass% carbon black and the amphoteric compound of 0.5-6 parts mass based on 100 parts mass rubber component until the temperature reaches 160°C or higher to form a master batch; and a second mixing step of kneading the formed master batch and butadiene rubber of the amount of ≤50 mass% of 100 mass% rubber component. |
