| 摘要 |
PURPOSE:To obtain an excellent transfer characteristic by limiting the content of ultrafine magnetic powder. CONSTITUTION:Ultrafine magnetic powder is powder consisting of magnetic particles having <=0.1mum number average grain size and is incorporated into a toner at <=20wt% thereof. The ultrafine magnetic powder has a large coloring power and the amt. to be incorporated of <=20wt% is enough in an empirical point of view and the amt. of >=5wt% is more preferable in terms of magnetic force and coloration. Any material which exhibits magnetism or is magnetizable is usable for the ultrafine magnetic powder, for example, ultrafine powders of metals including iron, manganese, nickel, cobalt, chromium, etc., alloys including iron-cobalt, iron-nickel, etc. and various ferrites are usable. |
