| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for kneading injection-moldable natural rubber, easily controlling its Mooney viscosity and giving the kneaded product of adequately low Mooney viscosity, by kneading the natural rubber stock incorporated with a kneading promoter under specific conditions and then kneading the above with a filler under specific conditions. SOLUTION: This method kneads (A) natural rubber incorporated with (B) a disulfide-based kneading promoter at 150 deg.C or lower for 10 to 17 min, and further kneads the above together with (C) a filler at 150 deg.C or lower for 10 min or shorter. It is preferable that 100 pts.wt. of the component A is kneaded together with 0.4 to 0.5 pt.wt. of the component B, e.g. 2,2'-dibenzamidodiphenyl disulfide incorporated with an activator, dispersant and oil or fat, and 40 pts.wt. or less of the component C, e.g. carbon black. |
