DEVELOPER AND PRODUCTION OF THIS DEVELOPER

摘要

PURPOSE: To obtain a developer which rapidly electrostatically charges toners for replenishment without the occurrence of trouble, such as filming, and with which images having less initial fogging are obtainable and a process for producing such developer. CONSTITUTION: The developer composed of toner particles contg. resins and coloring agents and carriers contg. ferrite or iron powder is so formed that the existence ratio of the toner particles having an electrostatic charge quantity of Q*1.5(μC) or above is <=14% when the average value of the electrostatic charge quantity possessed by one piece of the toner particle is defined as Q(μC). The carriers and the toner particles are charged in this order into a mixer and are one discharged during the course of mixing and are then charged into a 'Nauta Mixer (R) (orbiting-screw mixer) 1 and are mixed until the target electrostatic charge quantity is attained at the time of preparing such developer.