Ricoh Company, Ltd.

Kouji Noge

Nobuyasu Makino

Kenta Kawasumi

A method for preparing a toner including 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 7 to 30 &#x3bc;m; 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 2 to 6 &#x3bc;m and an average circularity of 0.93 to 0.96. A toner including toner particles including at least a binder resin and a colorant and prepared by the method. An image forming apparatus including an image bearing member configured to bear an electrostatic image thereon; and a developing device configured to develop the electrostatic image with a developer including the toner.

Method for preparing toner, toner prepared by the method, and image forming apparatus using the toner

To provide an electrophotographic toner pulverizing apparatus and an electrophotographic toner pulverizing method for preventing reduction in wear resistance of a rotor, a stator, and the like even in long-term pulverizing of toner. The electrophotographic toner pulverizing apparatus according to the present invention has a pulverizing chamber with at least a rotor and a stator disposed therein. The surface of at least one of the rotor and the stator has a chromium plated layer having Cr as a main component and containing Mg, Al, Si, Ti, Mn, Fe, and C elements.

Electrophotographic toner pulverizing apparatus and electrophotographic toner pulverizing method

A pulverizing and coarse powder classifying apparatus including: a mechanical pulverizer that pulverizes a powder raw material, a cyclone that collects pulverized powder, and a coarse powder classifier that separates coarse powder from the collected powder, wherein the coarse powder classifier is a cyclone classifier including a dispersion chamber equipped with a center core and used for dispersing the powder, and a classification chamber equipped with a separator core, and wherein the center core has at its center a fine powder discharge pipe.

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Numazu, Japan

Kouji Noge