| 摘要 |
PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor or more particularly an organic photoreceptor which is further improved in durability by lowering the coefficient of friction on the surface of the uppermost layer of the photoreceptor, is improved in cleaning characteristics and makes it possible to stably obtain high-density and bright images at all times. SOLUTION: The uppermost layer of this electrophotographic photoreceptor contains spherical hydrophobic silica particulates which satisfy the following conditions (i) and (ii) and are 0.01 to 5μm in the average grain size of the primary particles. (i) The silica particulates disperse uniformly into an organic compound which is liquid at room temperature and has a dielectric constant of 1 to 40 F/m when this organic compound and the silica particulates are mixed at a weight ratio of 5:1 and are shaken. (ii) The ratio of the quantity of the primary particles remaining as primary particles to the quantity of the initially existing primary particles is >=20% when the dispersion prepared by dispersing the silica particulates into methanol is held for two hours at 100 deg.C after the methanol is distilled away under heating in an evaporator.
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