| 摘要 |
PURPOSE:To provide the wide setting latitude for developing conditions and to prevent the air breakdown of a developing bias by incorporating the pulverous particles having the same polarity as the electrostatic charge polarity of a toner and the pulverous particles having the polarity reversed from said polarity into said toner. CONSTITUTION:A developer is obtd. by kneading 8pts.wt. carbon black as a coloring agent, 0.5pt.wt. chromium-contg. metallic dye which is a negative polarity controlling agent, 2pts.wt. silicon dioxide powder which is the pulverous particles having the same polarity as the polarity of the toner and is subjected to a hydrophobing treatment and 1pt.wt. silicon dioxide powder which is the pulverous particles having the reversed polarity therefrom and is subjected to a surface treatment with an amino compd. with 100pts.wt. styrene/n-butyl methacrylate copolymer as a binder and pulverizing and classifying the mixture. The latitude for setting the developing conditions is remarkably improved by using such developer as is evident from the figure. |
