PRODUCTION OF TONER FOR TWO-COMPONENT DEVELOPMENT

PURPOSE:To sharpen a charge distribution and to decrease sticking of the toner to the non-image part of a photosensitive body and staining of the inside of an electrophotographic copying device by subjecting toner particles to a heating treatment at the temp. below the glass transition temp. of a binder resin. CONSTITUTION:The toner particles are formed by kneading the binder resin and coloring agent and grinding the mixture and an external additive is added thereto so as to be stuck to the toner particles. The toner particles are then subjected to the heating treatment at the temp. below the glass transition point of this binder resin. The binder resin to be used is exemplified by polystyrene, styrene-alkyl acrylate, etc. The coloring agent is exemplified by, for example, a carbon black, oil black, graphite, etc. The desired electrostatic charge quantity is attained in this way and the excellent charge exchangeability is obtd. The charge distribution is sharp even after toner admixing and the sticking of the toner to the non-image part of the photosensitive body decreases; in addition, the staining in the machine decreases.