Non-magnetic single-component toner, method of preparing the same, and image forming apparatus using the same

Abstract

A non-magnetic single-component tonerof the present invention has toner mother particles, and external additivescomprising: two hydrophobic silicasof which particle diameters are different from each other, i.e. a mean primary particle diameter of 7 nm to 12 nm and a mean primary particle diameter of 40 nm to 50 nm, and a hydrophobic rutile/anatase type titanium oxidehaving a spindle shape of which major axial diameter is in a range from 0.02 nm to 0.10 nm and the ratio of the major axial diameter to the minor axial diameter is set to be 2 to 8, wherein the external additivesadhere to the toner mother particles. By the hydrophobic silicashaving work function smaller than the work function of the toner mother particles, the negative charging property is imparted to the toner mother particlesand the fluidity is also insured. On the other hand, by mixing and using hydrophobic rutile/anatase type titanium oxide particleshaving work function larger than or equal to the work function of the toner mother particlestogether with the hydrophobic silicas, the non-magnetic single-component toneris prevented from excessively charged. Therefore, the amount of fog toner on non-image portions is reduced, the transfer efficiency is further improved, the charging property is further stabilized, and the production of reverse transfer toner is further inhibited.