| 摘要 |
PURPOSE:To obtain the toner having always stable triboelectrostatic chargeability and bright image characteristics free from fogging by using a specific external additive and color toner and applying a specific grain size distribution to a part of toner particles. CONSTITUTION:The external additive has 20 to 200mum grain size and 10<6> to 10<14>OMEGA cm resistivity and is org. resin particles which are charged to the polarity reverse from the polarity of a coloring agent-contg. resin particles when triboelectrostatic charged with iron powder. The volume average diameter of the color toner is 6 to 10mum. The toner particles having <= 5mum grain size are incorporated at 15 to 40 number%, 12.7 to 16.0mum at 0.1 to 5.0 vol.% and >=16mum at <= 1.0 vol.% into the color toner. The toner particles of 6.35 to 10.1mum are so incorporated in the toner as to have the grain size distribution satisfying equation I. The electrostatic chargeability in various environments is stabilized in this way and the good color images free from the fogging are formed. |
