Kao Corporation

Shunji Arita

Shinichiro Omatsu

A process for preparing a toner comprising the steps of (1) pulverizing a pulverized product of a composition comprising a resin binder and a colorant with a jet type pulverizer in the presence of fine inorganic oxide particles, 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 a classifying rotor comprising 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 rotor, wherein the stationary spiral guiding vane is arranged in a classification zone on an outer circumference of the classifying rotor with a given spacing to the outer circumference of the classifying rotor. The toner obtained according to the present invention can be used for, for example, developing a latent image formed in electrophotography, electrostatic recording method, electrostatic printing method, or the like.

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Wakayama, Japan

Shunji Arita