TONER FOR DEVELOPMENT OF ELECTROSTATIC LATENT IMAGE

摘要

PURPOSE:To obtain stable pictures even in case of continuous copies by subjecting the surface of toner particles relatively large in size to a prescribed insulating processing and making the insulating property of surfaces of toner particles having a relatively small particle size lower than that of said toner particles to develop both toners uniformly. CONSTITUTION:A fine hydrophobic powder is added to the toner having a large particle size out of toners having prescribed particle size distributions, and the quantity of charging of this toner is so adjusted that it is matched to a system. For the purpose of making the quantity of charging of the classified toner having a small particle size equal to or slightly larger than that of said toner having a large particle size, the quantity of the added silica is reduced or the quantity of added fine alumina powder having a low charging property is reduced or a conductive fine powder such as carbon black or the like is added. Two kinds of toner which are processed in this manner are mixed to average the quantity of charging per unit weight of individual particles.