Electric charge control medicine and toner null C.I. solvent black 7

摘要

PROBLEM TO BE SOLVED: To provide a nigrosine-contg. electric charge controlling agent having improved electrostatic charge kick-off property and stability and no environmental dependency and giving a toner having improved anti-offsetting property, fixability, heat and light resistances and to obtain a toner for developing an electrostatic charge image contg. the electric charge controlling agent. SOLUTION: This toner contains an electric charge controlling agent contg. a nigrosine compd. as an effective component. The nigrosine compd. is obtd. by allowing C.I. Solvent Black 7 or C.I. solvent black 5 to react with one or more kinds of surface active anionic org. compds. selected from among sulfonic acid, sulfuric ester, phosphoric ester and carboxylic acid compds. The carboxylic acid compd. is not satd. or unsatd. fatty acid (salt).