| 摘要 |
PURPOSE:To improve flowability, environmental stability, filming preventive effect, effect of eliminating thickening of characters, offset preventive effect, cleanability and electrostatic charge stability by internally adding hard fine powder which does onto contain particles of large grain sizes and externally adding hydrophobic hard fine powder which is small in grain size to the toner. CONSTITUTION:The hard fine powder which has 0.3 to 1mum volume average grain size and does not contain the particles larger than 5mum grain size is internally added to the toner and the hydrophobic hard fine powder having <=0.3mum volume average grain size is externally added thereto. The hard fine powder which has 0.3 to 1mum volume average grain size and does not contain the particles larger than 5mum grain size is stable in electrostatic charge quantity, narrow in electrostatic charge quantity distribution, less in the fluctuation of the resistance and excellent in polishing effect. The hard fine powder having <=0.3mum volume average grain size sufficiently maintains the flowability. The flowability, environmental stability, filming preventive effect, effect of eliminating thickening of characters, offset preventive effect cleanability and electrostatic charge stability are improved in this way. |
