| 摘要 |
PURPOSE:To fully exhibit the effect of AC electric fields and to increase the image density of copied images and exceedingly improve brightness by regulat ing the surface reforming rate of a magnetic toner to a specific range. CONSTITUTION:The developer is formed as one-component developer contg. the magnetic toner obtd, by subjecting the particle powder contg. at least a resin, magnetic material and polyolefin to a mechanical spheroidization treat ment. The surface reforming rate alpha defined by equation I of this magnetic toner is specified to 4-16. In the equation I, A denotes the content (weight %) of the polyolefin in the magnetic toner material; PSI1 denotes the wadell's spheroi dicity of the particle powder before the mechanical spheroidization treatment; PSI'2 denotes the Wadell's spheroidicity of the particle powder after the mechani cal spheroidization treatment. The AC electric fields act well on the magnetic toner in this way and the images having the high image density and excellent brightness are formed. |
