| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing a rubber composition which can improve low heat generation performance of vulcanized rubber while improving processability of the rubber composition.SOLUTION: A method for producing a rubber composition includes: a step (I) of, after mixing a diene rubber and carbon black by kneading, discharging a mixture containing the diene rubber and the carbon black from an internal mixer; a step (II) of crushing a reaggregated product of the carbon black in the mixture by kneading the mixture again in the internal mixer; and a step (III) of, after the step (II), feeding a dihydrazide compound into the internal mixer and mixing the mixture and the dihydrazide compound by kneading. In the step (II), a kneading time is at least 15 seconds or more, and the rotational speed of an agitating rotor of the internal mixer is 35 rpm. In the step (III), a kneading time is at least 40 seconds or more, and the rotational speed of the agitating rotor of the internal mixer is 15-25 rpm or more. |
