Canon Kabushiki Kaisha

Nobuyuki Asaoka

Norio Hikake

Naoto Kitamori

Colored resinous particles suitable for use in toner powder for developing electrostatic latent images are produced from a pulverized feed at a good production efficiency and with a sharp particle size distribution through a classifying and pulverizing system including a second pulverization step associated with a second classification step in addition to a first classification step, such a second classification step and first pulverization step. The pulverized feed supplies to the first classification step is classified into a first classified fine powder and a first coarse powder, which is then pulverized in the first pulverization step and recycled to the first classification step. The first classified fine powder is supplied to the second classification step and classified therein into a second classified fine powder and a second coarse powder, which is then pulverized in the second pulverization step and recycled to the first classification step or the second classification step. The second pulverization step is effected under the action of an impact force which is smaller than that exerted in the first pulverization step.

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Abiko, Japan

Nobuyuki Asaoka