| abstract |
PURPOSE:To enhance development efficiency and cycle stability, and to lower the potential of a toner layer by adding carbon black to a high resistance magnetic toner in a specified range of proportion. CONSTITUTION:One component type magnetic toner is used contg. 0.2-0.7wt% carbon black. When it contains no carbon black, toner layer potential is high, and triboelectric charge among the toner itself and between the toner and other materials are ready to occur. When it contians 0.7-1.0wt%, a layer of conductive particles is formed on the surface of each toner particle, and exchange of the electrostatic charge is smoothly executed at the time of peeling charging, resulting in lowering and stabilizing toner layer potential. When the carbon content is low, the toner layer potential rises with the time length of continuous rotation of the toner around a developing roll, and exerts influence on the cycle stability of development. Therefore, it is desirable to control the carbon content of the range of 0.2-0.7wt%. |