Ricoh Company, Ltd.

Kenichi Uehara

Noboru Kuroda

Yasuaki Iwamoto

Junichi Watanabe

Tomio Kondou

Kohki Katoh

Keisuke Tada

Yoshihiro Sugiyama

Yasushi Nakamura

Daisuke Misawa

Ryoichi Ito

Junya Koeda

Masato Kobayashi

Satoshi Okano

Nobuyasu Makino

Takahiro Kadota

Hiroyuki Yoshikawa

Hiroshi Endoh

Kazuyuki Matsui

Yasuyuki Sanui

Miyuki Hirata

Osamu Kouzu

Eisuke Sugisawa

Ayumi Oikawa

Keiko Watanabe

A method for manufacturing a toner, including at least: dissolving or dispersing a toner material including at least any one of a binder resin and a precursor of a binder resin in an organic solvent which is dispersed in a dispersant-including aqueous medium; forming particles by removing the organic solvent; washing the particles; forming voids in the particles by heating to a temperature T while or after dispersing the particles in an aqueous medium; forming toner base particles by adding a charge controlling agent; and adding an external additive to the toner base particles to obtain toner particles, wherein the T is between a glass transition temperature Tg of the toner particles and Tg+25&#xb0; C., and the toner has a cross-sectional void fraction Sp/St of 0.1% to 15.0%, where St is a cross-sectional area of the toner particles, and Sp is a cross-sectional area of the voids.

Method for manufacturing toner, toner and image forming method

A reactor, which heats a slurry raw material including a solid component, including a reaction tube, wherein the slurry raw material is continuously fed from an end of the reaction tube relative to the central axial direction of the reaction tube so as to be flown toward another end of the reaction tube to be heated; and plural perforated plates arranged in the reaction tube so as to separate the inside of the reaction tube into plural compartments. The reactor satisfies the relations (&#xbd;)&#xb7;D'&#x2266;D&#x3c;D&#x2032;, and 0.2&#x2266;S/D&#x2032;&#x2266;5.0, wherein D represents the diameter of each of the perforated plates, D&#x2032; represents the inner diameter of the reaction tube, and S represents the interval between any two adjacent perforated plates in the central axial direction of the reaction tube.

Reactor, toner production method, and toner

A method of manufacturing toner including preparing a first liquid by dissolving or dispersing toner components including one or both of a binder resin and a precursor thereof in an organic solvent; preparing a second liquid by dispersing the first liquid in a first aqueous medium including a dispersant; producing primary particles by removing the organic solvent from the second liquid; washing the primary particles; preparing a third liquid by dispersing the washed primary particles in a second aqueous medium and heating the second aqueous medium while or after dispersing the washed primary particles therein; and producing toner particles by adding a charge controlling agent to the third liquid. This method satisfies the following inequation:0.60&#x2266;&#x2266;1.00wherein Sa represents a BET specific surface area of the primary particles included in the third liquid and Sb represents that of the toner particles stored for 2 weeks at 40&#xb0; C., 70% RH.

Method of manufacturing toner and toner

A cyclone classifier for classifying a particulate material, including an outer cylinder having a waistless part and an inverted-cone part vertically connected to an underside of the waistless part, and an inner cylinder which includes an exhaust opening such that the inner cylinder has a position-adjustable bottom end.

Cyclone classifier, flash drying system using the cyclone classifier, and toner prepared by the flash drying system

A method of producing a toner composition, including stirring and mixing toner particles comprising a binder resin, a colorant and a release agent with a charge controlling agent in a fluidizing and stirring mixer comprising a rotor having a stirring blade to fix the charge controlling agent on a surface of the toner particles, wherein the stirring and mixing comprises rotating the rotor at a peripheral speed of from 65 to 120 m/s at an environmental temperature (T) in the fluidizing and stirring mixer, satisfying the relationship,Tg-10&#x3e;T&#x3e;Tg-35(&#xb0; C.), where the Tg represents a glass transition temperature of the binder resin.

Method and apparatus for producing toner for electrophotography

A two-component developer includes a magnetic carrier including magnetic carrier particles with an average particle diameter of 35 &mgr;m to 100 &mgr;m, and a toner including toner particles with a weight-average particle diameter of 6.0 &mgr;m to 11.5 &mgr;m, to which at least one additive is externally added thereto in an amount of 0.3 to 1.5 wt. % to the toner, the toner particles including (a) toner particles with a particle diameter of 5 &mgr;m or less with a content ratio of 15% or less by number, and (b) toner particles with such a particle diameter that is two times or greater than the weight-average particle diameter of the toner particles with a content ratio of 5% or less by volume, the toner particles satisfying a relationship of 0.60&lE;D25/D75&lE;0.85 as defined in the specification. A container in which the two-component developer is contained, and an electrophotographic image formation apparatus in which the container is incorporated are proposed.

Two-component developer, two-component developer holding container, and electrophotographic image formation apparatus equipped with the container

A toner is made or toner particles which contains a binder resin and a coloring agent, wherein the toner particles have a weight-average particle size in a range of 6.0 to 11.5 &mgr;m, and contains toner particles (a) with a particle diameter of 5 &mgr;m or less in a content ratio of 1 to 15% by number, and toner particles (b) with a particle diameter of twice or more the weight-average particle size in a content ratio of 5 wt % or less, and the number-average particle size D25 and the number-average particle size D75 respectively obtained when the cumulative number of the toner particles reaches 25% and 75% at the measurement of a cumulative toner particle distribution by number thereof are in the relationship of 0.60&lE;D25/D75&lE;0.95. A two-component developer includes the above-mentioned toner and a carrier.

Toner and two-component developer for electrophotographic process and image formation method and image formation apparatus using the toner

A classifying device including an upper, dispersing chamber for dispersing solid particles supplied thereto together with a carrier gas, and a lower, classifying chamber directly connected to a lower end of the dispersing chamber for centrifugally classifying the solid particles, supplied from the dispersing chamber to the classifying chamber, into relatively fine particles and relatively coarse particles. The dispersing chamber is provided with a rotor for swirling the solid particles in the dispersing chamber.

Classifying device

Growing community of inventors

Shizuoka, Japan

Kenichi Uehara