| abstract |
Magnetic toners capable of exhibiting stable chargeability regardless of environmental change are formed from magnetic toner particles each including at least a binder resin, iron oxide and a sulfur-containing polymer, and inorganic fine powder mixed with the magnetic toner particles. Magnetic toner also satisfies good developing performance and high transferability by satisfying a weight average particle size (D4) of 3 to 10 μm, an average circularity of 0.970 or more and a magnetization of 10 to 50 A m 2 / kg at a magnetic field of 79.6 μs / m. to provide. In addition, the magnetic toner retains an amount of carbon of A and an amount of iron of B on its surface when measured by X-ray photoelectron spectroscopy, satisfying B / A <0.001, and the magnetic toner has a D / C ≤0.02 ( Where C denotes the perspective area equivalent circle diameter of each magnetic toner particle, and D denotes the magnetic toner particles satisfying the relationship between the surface of the magnetic toner particles and the iron oxide particles contained in the magnetic toner particles). It is characterized by containing 50% or more by number. |