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Magnetic toner, image forming method and process cartridge

  • US 6,007,957 A
  • Filed: 09/24/1998
  • Issued: 12/28/1999
  • Est. Priority Date: 09/25/1997
  • Status: Expired due to Term
First Claim
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1. A magnetic toner comprising:

  • magnetic toner particles containing at least a binder resin and magnetic iron oxide;

    wherein the magnetic iron oxide contains 0.2 to 4.0% by weight of at least one metal element selected from the group consisting of Mn, Zn, Ni, Cu, Co, Cr, Cd, Al, Sn and Mg, and 0.2 to 0.8% by weight of silicon element based on an iron element;

    the ratio (Bsi /ASi

    100 of the content BSi of the silicon element present in the magnetic iron oxide up to an iron element solubility of 20% by weight to the total content ASi of the silicon element present in the magnetic iron oxide is 45 to 85%;

    the ratio (Csi /Asi

    100 of the content CSi of the silicon element present in the magnetic iron oxide up to an iron element solubility of 10% by weight to the total content ASi is 35 to 70%; and

    the magnetic toner has a weight average particle diameter of 3.5 to 10.0 μ

    m, and contains 0 to 30% by volume of magnetic toner particles having a volume particle diameter of 12.7 μ

    m or more determined from a volume distribution.

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