Non-scorching carbon black product and process of making the same

摘要

Furnace carbon black for use in rubber compositions is rendered non-scorching by pelleting the flocculent black in the presence of an aqueous solution of a watersoluble oxidizing agent, drying the pellets and heating them to a temperature of 250-650 DEG F. in a current of inert gas, e.g. air. The oxidizing agent may be nitric acid, hydrogen peroxide, sodium hypochlorite, potassium bichromate, or potassium permanganate. The resulting pellets preferably have a "volatile content" of 1-3 per cent. The concentration of nitric acid may be 5-25 per cent and the acid may be used in an amount to provide 0.031-0.138 lb. HNo3/lb. black (equivalent to 55.2-62 per cent aqueous solution based on the black). It is assumed that a concentration of 7.5 per cent in an amount of 80 per cent is optimum.