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Magnetic carrier and two-component developer

  • US 9,063,443 B2
  • Filed: 05/23/2013
  • Issued: 06/23/2015
  • Est. Priority Date: 05/28/2012
  • Status: Active Grant
First Claim
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1. A magnetic carrier of which a resin-filled core is coated with a vinyl-resin, the resin-filled core having a porous ferrite particle in pores of which a resin is filled, whereinthe porous ferrite particlei) has a resistivity at 100 V/cm of from at least 8.0×

  • 104 Ω

    ·

    cm to not more than 5.0×

    106 Ω

    ·

    cm,ii) contains an oxide of Mg in the range from at least 1.00 mass % to not more than 15.00 mass % as MgO with reference to the mass of the porous ferrite particle, andiii) contains an oxide of Sr and an oxide of Ca, with a total content of these oxides of from at least 0.20 mass % to not more than 3.00 mass % as SrO and CaO with reference to the mass of the porous ferrite particle, and whereinin a backscattered electron projection image of the magnetic carrier obtained by using a scanning electron microscope at an acceleration voltage of 2.0 kV, the magnetic carrier has a total area for regions originating from the porous ferrite particle of from at least 0.2 area % to not more than 5.0 area % with reference to the projected area of the magnetic carrier.

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