| 摘要 |
PURPOSE:To improve the electrostatic chargeability and cleanability in various environments by adding specific external additives to the toner and specifying the grain size distribution of the toner. CONSTITUTION:The color toner consist of at least nonmagnetic coloring agent- contg. resin particles and the external additives. The external additives consist at least of titanium oxide or alumina and the org. resin particles which have two peaks at 20 to 200mum and 300 to 800mum grain sizes, have 10<6> - 10<14>OMEGA.cm electric resistivity and are charged to the polarity reverse from the polarity of the coloring agent-contg. resin particles when triboelectrostatically charged with iron powder. The weight average grain size of the color toner is 6 to 10mum and the color toner is so formed that the toner particles having <=5mum grains size are incorporated therein at 15 to 40 number%, the toner particles having 12.7 to 16.0mum at 0.1 to 5.0vol.%, and the toner particles having >=16.0mum at <=1.0vol.%. The toner particles sized 6.35 to 10.1mum are so formed as to satisfy equation I. In the equation I, V: vol.% of the toner particles having 6.35 to 10.1mum grain size, N: number % of the toner particles having 6.35 to 10.1mum grain size, d'4: the weight average grain size of the total toner particles. |
