JP2578489B

PURPOSE:To obtain the negative electrostatic chargeable color toner which is hardly affected by external additives by incorporating a negative chargeable binder resin, specific metal complex and a positive chargeable coloring material treated with the homopolymer or copolymer of a nitrogenous vinyl monomer into the toner. CONSTITUTION:The binder resin is prepd. by dispersing a negative charge control agent and the electrically positive coloring agent into a negative chargeable thermoplastic resin. The metal complex of salicylic acid, alkylsalicylic acid or dialkylsalicyclic acid which ion-crosslinks the binder resin at the time of thermal kneading with the binder resin is used for the negative charge control agent. The pigment which is subjected to a coating treatment with the homopolymer or copolymer of the nitrogenous vinyl monomer and is electrically electrified and intensified positive is used as the coloring agent. The specific negative chargeable color toner which has the less dependency of the developing characteristics of the toner on environment and can maintain the initial development characteristics even after repetitive use is obtd. in this way.