| 摘要 |
PURPOSE:To obtain an electrophotographic developer for use in a high-speed copying machine, having a long life and low running cost, by incorporating fine carrier powder, fine toner power, and fine conductive particles. CONSTITUTION:A colorant, such as carbon black is dispersed into a styrene type binder resin, kneaded, and finely pulverized to obtain a fine toner having <=6mum number average particle diameter measured with a coal counter, and <=8mum volume average particle diameter. Then, fine carrier powder having 10-20mum number average particle diameter, such as ferrite, and 0.01-10wt% conductive fine particles, such as SnO2, are added to 100pts.wt. toner and mixed. As a result, an electrophotographic developer stable in image quality in whatever environments it is used is obtained. |
