| 摘要 |
PURPOSE:To improve flowability and transportability and to provide higher image quality and longer life by externally adding specific silica to a base body, setting a BET specific surface area within a prescribed range and regulating the same under the conditions to reflect the amt. of the silica to be externally added and the state of the silica penetrated into the base body. CONSTITUTION:The silica to be externally added is specified to 10 to 100nm average particle size and is uniformized in the distribution state on the surface. The electrostatic charge quantity of the blow off particles is specified to +50 to +500muc/g to optimize the electrostatic charge characteristic on the surface. The BET specific surface area after the external addition of the silica is set in the prescribed range, by which the flowability and transportability are satisfied; further, the BET specific area is specified to 1.0 to 3.0m<2>/g, by which the characteristics are assisted and the image quality is improved. The longer life is thus obtd. |
