PRODUCTION OF OIL-TREATED INSOLUBLE SULFUR WITH IMPROVED FLUIDITY

摘要

PURPOSE:To obtain the titled oil-treated insoluble sulfur having excellent fluidity and highly dispersible in rubber by mixing the dry powder of the insoluble sulfur purified with CS2 contg. alpha-methylstyrene and a rubber processing oil by a specified two-stage mixing method. CONSTITUTION:Insoluble sulfur powder is added into carbon disulfide contg. alpha-methylstyrene, sufficiently agitated, and mixed. The mixture is filtered and dried to obtain the dry powder of the purified insoluble sulfur. Then 0.3-0.5pts. wt. rubber processing oil is added to 1pts.wt. insoluble sulfur, and the first-stage mixing is carried out by a high-speed mixer. Then the dry powder of the purified insoluble sulfur is added to the mixture to control the content of the rubber processing oil in the whole material to 17-22%, the second-stage mixing is performed, and the desired oil-treated insoluble sulfur is obtained. The obtained oil-treated sulfur is appropriately used especially as the vulcanizing agent for a radial tire.