Ricoh Company, Ltd.

Mitsui Petrochemical Industries, Ltd.

Chiharu Mochizuki

Yoshihisa Okamoto

Yasuo Asahina

Shinichi Kuramoto

Tomomi Suzuki

Hidefumi Gohhara

Michio Izumi

Hiroaki Matsuda

Satoru Inoue

Hideo Nakamura

Akio Matsui

Shunichi Chiba

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

Growing community of inventors

Numazu, Japan

Chiharu Mochizuki