Patent ID: 7560218

Claim:
A process for preparing a toner comprising the following steps: (1) pulverizing a pulverized product, which has a volume-median particle size (D 50 ) of from 10 to 1000 μm, of a composition comprising a resin binder and a colorant with a jet pulverizer in the presence of fine inorganic oxide particles, wherein the jet pulverizer is a fluidized bed jet mill, to give an upper limit cut-off classification powder; and (2) classifying the upper limit cut-off classification powder with a classifier, the classifier comprising two classifying rotors sharing a driving shaft arranged in one casing as a central shaft thereof in a vertical direction, and a stationary spiral guiding vane arranged to share the same central shaft as the classifying rotors, wherein the stationary spiral guiding vane is arranged in a classification zone on an outer circumference of the classifying rotors with a given spacing to the outer circumferences of the classifying rotors, wherein the toner has a volume-median particle size (D 50 ) of from 3.5 to 6.5 μm, wherein the fluidized bed jet mill satisfies a formula (A): 0.55 <L/D <0.65 ( A ) wherein L is a nozzle distance of the fluidized bed jet mill, and D is a body diameter of the jet mill.