METHOD FOR PRODUCING ELECTROSTATIC CHARGE CONTROLLING AGENT-CONTAINING FERRITE PARTICLE

摘要

PROBLEM TO BE SOLVED: To prevent the lowering of the image density and resolution of a toner and fogging and to enhance transfer efficiency. SOLUTION: An iron-containing salt, a solvent and an alkali metal hydroxide are mixed and oxidized to obtain a reacted mixture containing a ferrite and a by-product. The ferrite is extracted from the mixture, a metallic salt- containing aqueous solution and an ion-containing aqueous solution of a carboxy compound are added to the ferrite and the resulting electrostatic charge controlling agent-containing ferrite is purified. A high purity ferrite 2 is contained in the obtained electrostatic charge controlling agent-containing ferrite particles 1 and the electrostatic charge controlling agent 3 is uniformly dispersed in a toner.