| 摘要 |
PURPOSE:To obtain a long-lived developer causing no reversal fog in a reversal developing device using an OPC by incorporating specified amounts of 2 kinds of silica specified in diameter and enhanced in hydrophobicness. CONSTITUTION:The developer contains the silica A having a primary particle diameter of 5-200nm and enhanced hydrophobicness and the silica B having a primary particle diameter of 0.5-5mu in amounts of 0.05-0.5wt.% and 0.3-1.0wt.%, respectively. The silica A and the silica B are added in order to give fluidity and to prevent reversal fog, respectively, and it is preferred to control the electric charge amount of the silica A to a lower value, preferably, to <=-100muC/g, and to select the size of the silica B larger enough than the roughness of the surfaces of the developer particles, thus permitting the obtained photosensitive body to be improved in fluidity and reversal fog resistance and to form a good-quality image for a long period. |
