| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent the occurrence of fog and leadoff over a long period of time and to reduce the consumption of a carrier by providing a specified BET specific surface area and a specified dynamic current value. SOLUTION: This carrier has 0.50-2.00 m2/g BET specific surface area and 15-170 nA dynamic current value. In the case of <0.50 m2/g BET specific surface area, the lowering of the initial electric charge imparting ability of the carrier due to the spending of a toner is remarkable in continuous copying because the number of charge sites of the carrier is small and fog occurs on a copied image. In the case of >2.00 m2/g, mechanical strength is insufficient and the increase of the consumption of the carrier is remarkable. In the case of <15 nA dynamic current value, image untransfer phenomenon (leadoff) occurs because the surface resistance of the carrier is relatively high. In the case of >170 nA, the carrier is supplied to development together with a toner in continuous copying because the surface resistance of the carrier is relatively low and the increase of the consumption of the carrier is remarkable.</p> |
