| 摘要 |
PURPOSE:To provide an electrophotographic positively chargeable toner superior in fluidity and chargeability by emulsion polymerizing an alpha-, beta-ethylenically unsaturated monomer in an aqueous medium in the presence of a surfactant of an alkali metal salt of a higher fatty acid and a polymerization initiator having a carboxylic acid or carboxylic acid salt, and adding the obtained vinyl resin particles to the surface of each toner particle. CONSTITUTION:At least one kind of alpha-, beta-ethylenically unsaturated monomer is emulsion polymerized in the aqueous medium in the presence of the surfactant of the alkali metal salt of a higher fatty acid and the polymerization initiator having a carboxylic acid or carboxylic acid salt, and the obtained fine vinyl resin particles having an average particle diameter of 0.02 - 0.1 mum are added to the surface of each toner particle. The charge amount of the toner with the fine resin particles attached is made smaller than that of each colorant particle by controlling charge, thus permitting the fine resin particle layer lower in charge to cover the outer side of each colorant particle higher in charge, accordingly, the chargeability of the toner to be little affected even if the sub stance on the surface of each toner particle is moved to a charge-giving mem ber, and the toner superior in stability with time lapse to be obtained. |
