MAGNETIC TONER Russian patent published in 2015 - IPC G03G9/08 G03G9/83 G03G9/87 

FIELD: printing.

SUBSTANCE: invention relates to a magnetic toner. The magnetic toner comprises the magnetic toner particles containing a binder resin and a magnetic material, and inorganic fine particles present on the surface of the magnetic toner particles, in which the inorganic fine particles present on the surface of the magnetic toner particles comprise metal oxide fine particles, metal oxide fine particles containing fine particles of silica and optionally containing fine particles of titanium dioxide and fine particles of aluminium oxide, and the content of fine particles of silica is at least 85 wt % relative to the total weight of the fine particles of silica, fine particles of titanium dioxide and fine particles of aluminium oxide. The degree of coating A (%) represents the degree of coating the surface of the magnetic toner particles with inorganic fine particles, and the degree of coating B (%) represents the degree of coating the surface of the magnetic toner particles with inorganic fine particles which are fixed on the surface of the magnetic toner particles. The magnetic toner has a degree of coating A and a ratio (degree of coating B/degree of coating A) in the prescribed intervals, at that the magnetic toner has a dielectric permittivity ε' and tangent of angle of dielectric losses in the prescribed intervals.

EFFECT: obtaining the magnetic toner which provides a stable image density regardless of the environmental conditions in the application, which prevents veiling and formation of bands.

6 cl, 5 tbl, 7 dwg, 33 ex