| 摘要 |
PURPOSE:To improve the dispersion and the adhesive strength of magnetic powders and to stabilize the amount of electrification of the subject toner, and to improve the fixation of the toner by incorporating the magnetic powders which are made to hydrophobicity on the surface thereof, and needle-like nonmagnetic metal oxides which are not made to the hydrophobicity in the magnetic toner. CONSTITUTION:The magnetic powders which are made to the hydrophobicity on the surface thereof in the needle-like nonmagnetic metal oxides which are not made to the hydrophobicity are incorporated in the toner. The needle nonmagnetic oxide is composed of a water contg. iron oxide (FeOOH) and hematite (alpha-Fe2O3), etc. The needle particle has a ratio of the major axis to the minor axis of a particle of >=3, preferably >=5. The magnetic powder is composed of a ferromagnetic element and an alloy contg. the element or a compd. contg. the element, etc. and a compd. such as magnetite, hematite, and ferrite and a metal or an alloy such as Fe, Co, Ni and Mn. A hydrophobic treating agent is composed of a surfactant such as a metal salt of fatty acid, etc. or a titanium coupling agent, etc. |
