Ricoh Company, Ltd.

Mitsui Petrochemical Industries, Ltd.

Yoshihisa Okamoto

Chiharu Mochizuki

Satoru Inoue

Yasuo Asahina

Shinichi Kuramoto

Tomomi Suzuki

Akio Matsui

Shunichi Chiba

Hidefumi Gohhara

Michio Izumi

Hiroaki Matsuda

Hideo Nakamura

Masaru Wakisaka

A dry toner for use in electrophotography including a coloring agent and a polyol resin serving as a binder resin, which has a main chain portion containing an epoxy resin moiety and an alkylene oxide moiety, and protected terminal portions bonded to the main chain portion.

Electrophotographic dry toner

A developer is composed of toner particles which contain a thermoplastic resin, a coloring agent, one component selected from the group consisting of a fluorine-containing quaternary ammonium salt compound and a fluorine-containing iminium compound, and an aromatic hydroxycarboxylic acid metallic salt. This developer may also contain a carrier.

Developer for developing latent electrostatic images

A set of color developers for use in multi-color electrophotography comprises (a) a yellow developer, (b) a magenta developer, (c) a cyan developer, and (d) a black developer, in which the viscoelasticity (tan.delta..sup.1) of each of the yellow developer, the magenta developer and the cyan developer is smaller than the viscoelasticity (tan.delta..sup.2) of the black developer at a storage modulus (G'(.omega.)) of 10.sup.5 dyn/cm.sup.2. This set of color developers is particularly suitable for use with a digital multi-color electrophotography.

Color developers for use in multi-color electrophotography and image

An electrographic process comprising the steps of forming latent electrostatic images on a photoconductive material, developing the latent electrostatic images with a toner to toner images, transferring the toner images to a recording sheet, fixing the toner images to the recording sheet by causing the toner image bearing recording sheet to pass between a heat application roller coated with a fluorine-containing resin and a pressure application roller for fixing to the toner images to the recording sheet, in which electrographic process the rheological characteristics of the toner are such that the loss tangent (tan .delta.), which is a ratio of the loss moldus (G') to the storage modulus (G') of the toner, is in the range of 1.70 to 3.00 when the storage modulus (G') is 10.sup.5 dynes/cm.sup.2, namely

Electrophotographic process using fluorine resin coated heat application

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Fuji, Japan

Yoshihisa Okamoto