| 摘要 |
PURPOSE:To prevent the degradation in the image density by an increase of the charge of a toner and carrier and to obtain stable images at the time of continuous copying of many sheets by incorporating a conductive metal oxide into the compounded compsn. of the color toner. CONSTITUTION:The color toner is provided by adding the conductive metal oxide having the following characteristics at 5 to 20% of the total weight of the toner to the compounded compsn. of the toner essentially consisting of a binder resin, coloring agent and charge control agent and by an ordinary hot kneading, grinding and classifying method. The conductive metal oxide which can be used in this case is fine powder which is transparent or white and has <=100OMEGA.cm volume resistivity value. Leak of charge arises hardly and the effect of the addition of the conductive metal oxide is not obtd. because of the high resistance if the volume resistivity value is larger than 100OMEGA.cm. The degradation in the image density is prevented while the increase of the charge of the toner and carrier is suppressed at the time of copying of many sheets. The copies which are free from a change in the image quality are thus obtd. |
