Patent ID: 6465144
Filing Date: 2002-10-15
Classification: G03G

Abstract:
A magnetic toner, comprising:(a) magnetic toner particles each comprising at least a binder resin and magnetic toner, and (b) inorganic fine powder externally blended with the magnetic tone particles; (c) wherein the magnetic toner has an average circularity of at least 0.970, the magnetic toner has a magnetization of 10-50 Am2/kg at a magnetic field of 79.6 kA/m, the magnetic powder comprises at least magnetic iron oxide, the magnetic toner particles retain carbon in an amount of A and iron in an amount of B at surfaces thereof as measured by X-ray photoelectron spectroscopy, satisfying: B/A<0.001, the binder resin comprises a resin formed by polymerization of a monomer comprising at least styrene monomer, the magnetic toner has a residual styrene monomer content of less than 300 ppm, and the magnetic toner contains at least 50% by number of toner particles satisfying a relationship of D/C&lE;0.02, wherein C represents a volume-average particle size of the magnetic toner, and D represents a minimum distance between a surface of a magnetic toner particle and magnetic powder particles contained in the magnetic toner particle.