Patent ID: 8257900

Claim:
A method for preparing a toner comprising: primarily pulverizing a toner composition powder including at least a binder resin and a colorant using a mechanical pulverizer to prepare a first particulate material with a weight average particle diameter of from 7 to 30 μm; secondarily pulverizing the first particulate material using a jet air pulverizer having a pulverization plate to prepare a second particulate material; and classifying the second particulate material in two steps to prepare particles of the toner with a weight average particle diameter of from 2 to 6 μm and an average circularity of from 0.93 to 0.96, wherein the primarily pulverizing step includes: primarily pulverizing a toner composition powder including at least a binder resin and a colorant using a mechanical pulverizer having a rotor rotated at a peripheral speed of not lower than 120 m/s while rounding the primarily pulverized toner composition powder to prepare a first particulate material with a weight average particle diameter of from 7 to 20 μm and an average circularity of from 0.94 to 0.96; and wherein the classifying step includes: classifying the second particulate material in two steps to prepare particles of the toner with a weight average particle diameter of from 2 to 5 μm and an average circularity of from 0.93 to 0.96.