| 摘要 |
PURPOSE:To suppress an increase in production cost by electrostatically sticking magnetic powder having the average grain size smaller than the average grain size of a nonmagnetic toner on the surface of said toner, then thermally melting the surface of the toner to stick the magnetic powder to the surface of the toner. CONSTITUTION:The toner for electrophotography formed by electrostatically sticking the magnetic toner having the average grain size smaller than the average grain size of the nonmagnetic toner to the surface of the toner, then thermally melting the surface of the toner to fix the magnetic powder to the surface of the toner is used. Any magnetic materials are usable as the magnetic powder and may be the fine powder of magnetic metals such as iron (Fe) and nickel (Ni), metal oxides such as ferrite (gamma-Fe2O3) and magnetite (Fe3O4) and magnetic alloys; above all, the iron, ferrite and magnetite are more adequate. Magnetism is thereby imparted only to the surface of the toner. Since the magnetic powder of the amt. slighter than general magnetic toners needs be used, the permissible latitude of the toner concn. is widened with a slight increase in production cost. |
