| 摘要 |
<p>PURPOSE:To promote the magnetic behavior of a magnetic toner, thereby to obtain a stable triboelectric charge quantity and also to improve the reproducibility of a halftone image by forming a coercive force of the magnetic toner smaller than a coercive force of a magnetic carrier. CONSTITUTION:In an electrostatic charge image developer composed of a mixture of the magnetic carrier and the magnetic toner essentially consisting of a binding resin and magnetic powders, the coercive force of the magnetic toner is formed smaller than the coercive force of the magnetic carrier. The magnetic powders can be formed of soft ferrite powders having 0.1 to 3mum average particle size. As the soft ferrite powders, for example, the one having a composition of (MO)x(Fe2O3)100-x is exemplified. Where, M is >=1 kinds of metals which are monovalent or bivalent and are selected from Mn, etc., and x is in a range of 45 to 80mol%. The magnetic toner having smaller coercive force than the coercive force of the magnetic carrier can follow the magnetic behavior of the magnetic carrier and the triboelectric charging actions between mutual magnetic toner particles and between the magnetic toner particles and the magnetic carriers are improved.</p> |
