| 摘要 |
PROBLEM TO BE SOLVED: To produce oxidized carbon black having the low contents of nitrogen oxides, etc., and excellent safety, imparting excellent flowability, when dispersed in an ink, and giving excellent gloss, when dispersed in a coating, by using an ozone-containing gas having a nitrogen oxide concentration of a specific value or smaller. SOLUTION: In this method for producing oxidized carbon black, the characteristic comprises using an ozone-containing gas having a nitrogen oxide concentration of <=80 ppm (for example, a gas obtained by generating ozone in an oxygen-containing gas having a nitrogen gas content of <=50 vol.% as a raw material by the use of a silent discharge type ozone generator). The production is preferably carried out by reacting 100 pts.wt. of carbon black having an aromatic hydrocarbon content of <=50 ppm with >=2 pts.wt. (as ozone) of the gas A. Thus, the carbon black having a total acidic group content of >=100 μequ/g, a nitrogen oxide content of <=20 ppm, a polycyclic aromatic hydrocarbon content of <=30 ppm and a nitropyrene content of <=3 ppm can be produced. |
