Mita Industrial Co., Ltd.

Hiroshi Komata

Yutaka Shigemura

Shigeo Kurando

Yoshinori Makiura

Eiji Mifune

Hidenori Asada

Mikio Ido

Tatsuo Imafuku

Junichi Ooura

Takahiko Kimura

Takeshi Arakawa

Masanori Fujii

Nobuyuki Tsuji

Shigeki Yamada

Atsushi Yamaguchi

Kiminori Umeda

Shunsuke Ogami

The present invention provides an electrophotographic toner containing, as a fixing resin, a styrene-acrylic copolymer in which styrene content and molecular-weight distribution are specified, and which contains a specific high-molecular-weight component. The electrophotographic toner of the present invention is improved in bending resistance while assuring excellent low-temperature fixing properties, resistance to off-set and heat resistance.

Electrophotographic toner

The present invention relates to a system for making discriminations between cartridges for housing toners to be equipped on image forming apparatus such as electrostatic copiers, laser beam printers, facsimiles, etc. in which while a cartridge indicating means is provided on a part of a toner housing cartridge, an indication detecting means for detecting the aforementioned cartridge indicating means is provided on the image forming apparatus proper side, so that the suitability of the type or position of the cartridge inserted is detected by detecting the cartridge indicating means by the aforementioned detecting means, when the cartridge has been inserted into the cartridge inserting part of the image forming apparatus proper.

Cartridge discriminating system

Disclosed is a toner for the electrophotography, which comprises as a main component a styrene/acrylic copolymer having at least two molecular weight distribution peaks, the molecular weight (Mw) of the peak on the lowest molecular weight side being lower than 13000, wherein the toner contains a charge controlling agent dispersed therein at a concentration of at least 0.3% by weight and the charge controlling agent has such a particle size distribution that the area ratio of particles having a particle size larger than 2.5 .mu.m is at least 80% based on the section of the toner. If this toner is used, the fixing-possible temperature can be broadened while increasing the fixing ratio without reduction of the performances of the toner.

Toner for electrophotography and process for preparation thereof

Growing community of inventors

Hyogo, Japan

Hiroshi Komata