METHOD FOR PRODUCTION OF NATURAL RUBBER-CARBON BLACK WET MASTERBATCH

摘要

PROBLEM TO BE SOLVED: To provide a method for production of a natural rubber-carbon black wet masterbatch further enhancing the dispersibility of carbon black in a rubber without excessively lowering the molecular weight of the natural rubber.;SOLUTION: A method for production of a natural rubber-carbon black wet masterbatch includes: a process of blending a natural rubber latex solution and a carbon black slurry solution in a liquid phase to prepare a liquid mixture; a process of chemically and/or physically coagulating the mixture and taking out a generated coagulation; and a process of dehydrating the coagulation to obtain a mixture. The moisture content of the mixture after the dehydration process by a twin screw extruder is 0.9 to 2%, and a mechanical energy imparted to the coagulation is 280 to 380 wh/kg. The method is characterized in that a filling factor (%) represented by: a screw radius (mm) of the twin screw extruder; one rotation pitch (mm) of the screw; a screw revolution (rpm); a coagulation amount (g/min) charged in the twin screw extruder; and the density (g/mm³) of the coagulation before the dehydration process satisfies the following expression (I): filling factor (%)=(charged amount (g/min))/[(screw revolution (rpm))×(one rotation pitch (mm) of screw)×π×{screw radius (mm)}²×density (g/mm³) of coagulation before dehydration process]=5 to 9 ... (I).;SELECTED DRAWING: None;COPYRIGHT: (C)2016,JPO&INPIT