| 摘要 |
PROBLEM TO BE SOLVED: To prevent the occurrence of a fog and uneven density and read-off over a long period by incorporating a binder carrier comprising a magnetic powder containing phosphorus and a binder resin. SOLUTION: The binder carrier comprises at least a magnetic powder containing phosphorus dispersed in a binder resin. As the magnetic powder to be used in this binder carrier, whatever magnetic powder can be used so long as it contains phosphorus, and for example, ferrite, magnetite, iron powder, and the like are enumerated, and it is preferred to use magnetite. A molar ratio of Fe<2+> /Fe<3+> is controlled to 0.1-0.5, preferably, to 0.15-0.48, further preferably, 0.25-0.40. The use of the magnetic powder containing the phosphorus permits the obtained carrier to be enhanced in charge stability and charge rising characteristics and to be prevented from the occurrence of a fog and uneven density and read-off over a long period. |
