| 摘要 |
This invention provides a magnetic toner which has good developing properties and is free from fogging and, even in a halftone site, can stably form images having a high level of blackness and free from uneven density. The magnetic toner comprises magnetic toner particles comprising at least a binder resin and magnetic iron oxide particles. The magnetic toner is characterized in that, when the amount of Fe element contained in a solution (Fe element dissolution rate: 10% by mass) relative to the amount of Fe element contained in a solution prepared by dissolving all the magnetic iron oxide particles in an aqueous acid solution is presumed to be the total Fe element amount, the proportion (X) of the amount of Fe(2+) contained in a solution (Fe element dissolution rate: 10% by mass) relative to the amount of Fe element contained in a solution (Fe element dissolution rate: 10% by mass), in which the magnetic iron oxide particles have been dissolved to such a state that 10% by mass of the total Fe element amount is present in the solution, is not less than 34% by mass and not more than 50% by mass, and that the magnetic toner satisfies the requirements that, for the dielectric dissipation factor measured at a temperature of 40°C, (a) the dielectric dissipation factor (A) at a frequency of 10000 Hz is not less than 1.0 x 10-6 and not more than 1.0 x 10-1, (b) the dielectric dissipation factor (B) at a frequency of 1000 Hz is not less than 1.0 x 10-6 and not more than 1.0 x 10-1, and (c) the ratio of the dielectric dissipation factor (A) to the dielectric dissipation factor (B), i.e., A/B, is not less than 0.10 and not more than 10.00.
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