Patent ID: 7740998
Filing Date: 2010-06-22
Classification: G03G

Abstract:
1. A positively chargeable developer comprising at least positively chargeable toner particles each containing at least a binder resin and magnetic iron oxide, wherein: an inorganic fine powder is externally added to the positively chargeable toner particles, the inorganic fine powder comprises a magnesium oxide fine powder; the magnesium oxide fine powder comprises a crystal system having a peak at a Bragg angle (2θ±0.2 deg) of 42.9 deg in CuKα characteristic X-ray diffraction; and a half width of the X-ray diffraction peak at the Bragg angle (2θ±0.2 deg) of 42.9 deg is 0.40 deg or less, an unconfined yield strength (U an unconfined yield strength (U