| 摘要 |
<p>PURPOSE:To obtain the dispersion-type carrier in which a magnetic powder and a binder resin are well-mixed and contg. the magnetic powder uniformly in large quantities by using a spherical magnetic powder having a specified Wadellisphereodicity. CONSTITUTION:This magnetic powder-dispersed electrostatic charge image developing carrier contains a magnetic powder and a binder resin. A spherical magnetic powder having 0.1-5mum average grain diameter is used as the fine magnetic powder. In this case, the two-dimensional projected image of a scanning electron microscope is used as measure, and a Wadellispheroidicity obtained by the tablet quantitative measuring method shown by the equation, Wadellisphereodicity (circumference of circle equivalent to projected area/ contour length of grain projected plan). The average Wadellis spheroidicity of the spherical magnetic power is preferably controlled to 0.9-1.1 or more preferably to 0.95-1.05. Besides, the magnetic powder is an ordinary ferromagnetic fine powder, and a modified magnetite contg. nickel and zinc, ferrite, iron powder, etc., are exemplified.</p> |
