Patent ID: 9062171
Filing Date: 2015-06-23
Classification: B29B,B60C,C08J,C08K,C08L

Abstract:
1. A method for producing a rubber composition, using an internal mixer having a stirring rotor to mix a diene rubber, a carbon black and a dihydrazide compound with each other, comprising step (I) of kneading the diene rubber and the carbon black to be mixed with each other, and then discharging the resultant mixture containing the diene rubber and the carbon black from the internal mixer, step (II) of kneading the mixture again in the internal mixer to crush a re-aggregate of the carbon black in the mixture, and step (III) of charging, after step (II), the dihydrazide compound into the internal mixer, and kneading the mixture and the dihydrazide compound to be mixed with each other, wherein in step (II), the period for the kneading is 15 seconds or longer, and the rotating speed of the stirring rotor of the internal mixer is 35 rpm or more, and in step (III), the period for the kneading is 40 seconds or longer, and the rotating speed of the stirring rotor of the internal mixer is from 15 to 25 rpm.