| 摘要 |
PROBLEM TO BE SOLVED: To provide a two component developer capable of achieving: the improvement of dot reproducibility in an electrostatic latent image; the prevention of image density lowering at the tail end of a solid image section; the prevention of the sticking of a carrier to a photoreceptor drum; and the prevention of image density lowering when being left alone under high temperature-high humidity. SOLUTION: Disclosed is a two component developer comprising: magnetic carriers; and toner, and each magnetic carrier comprises resin-containing magnetic particles in which the vacancy of each porous magnetic core particle includes a resin component. The two component developer is used for an image forming apparatus using a photoreceptor provided with: a conductive substrate; a photoconductive layer at least including amorphous silicon on the conductive substrate; and a surface protective layer. Regarding each porous magnetic core particle, provided that compaction apparent density is defined asρ1 (g/cm<SP>3</SP>) and true density is defined asρ2 (g/cm<SP>3</SP>),ρ1 is 0.80 to 2.40 andρ1/ρ2 is 0.20 to 0.42, the specific resistance (Ωcm) of each porous magnetic core particle satisfies 1.0×10<SP>3</SP>to 5.0×10<SP>7</SP>, and the specific resistance (Ωcm) of each magnetic carrier satisfies 1.0×10<SP>10</SP>to 1.0×10<SP>17</SP>. The toner comprises toner particles at least comprising a binder resin and a release agent, and has one or more heat absorption peaks in the temperature range of 30 to 200°C in a heat absorption curve measured with a differential scanning calorimeter, and the peak temperature of the maximum heat absorption peak in the one or more heat absorption peaks is 55 to 140°C. COPYRIGHT: (C)2009,JPO&INPIT
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