PURPOSE: To exhibit high positive electrification stably for a long period and to obtain an image of high resolution by mixing inorganic fine particles obtained through surface treatment of polysiloxane having ammonium salt as a functional group, toner having a specific mean particle diameter, and a resin-covered carrier with each other.
CONSTITUTION: Toner having a mean particle diameter of 2-6μm, obtained by combining inorganic fine particles prepared by surface treatment of polysiloxane having ammonium salt as a functional group with primary particles of a mean particle diameter 0.1-3μm prepared by a polymerization method in an aquatic medium in the same aquatic medium, is mixed with a resin- covered carrier. As the inorganic fine particle, a fine particle of, for example, silica, alumina, titanium oxide and the like are adopted, wherein a silica fine particle is particularly desirable in view of fluidity improvement. A containing ratio of the inorganic fine particle in the toner is desirably 0.5-3 weight %, and 0.5-2 weight % is particularly desirable.
OKUYAMA TAKEKI
TSUJITA KENJI
