| 摘要 |
PURPOSE:To stabilize the triboelectrostatic chargeability of the developer and to form the developer so as to exhibit uniform positive chargeability even under various environments by incorporating a carbon black treated by a specific silicone oil into the developer. CONSTITUTION:The developer is so formed as to contain the carbon black treated with the silicone oil expressed by formula I. In the formula, R denotes hydrogen or methyl group. The carbon black having 10 to 70mmu particle size is used as the carbon black to constitute one constituting component of the developer. Above all, conductive furnace black and oil furnace black are used. The silicone oil having <=100cps viscosity at 25 deg.C among the silicone oils is adequate for treatment of the carbon black. The developer having the positive chargeability without having a change in electrostatic characteristics even after the execution of repetitive copying over a long period of time under low humidity is obtd. in this way. |
