Kabushiki Kaisha Toshiba

Toshiba Tec Kabushiki Kaisha

Tokyo Electric Co.

Toshiba America Business Solutions, Inc.

The Electric Co., Ltd.

Shuitsu Sato

Takashi Urabe

Yasuhito Noda

Masahiro Hosoya

Mitsunaga Saito

Mitsuharu Endo

Yukio Futamata

Satoshi Takayama

Takahito Kabai

Kenji Sano

Shigeru Machida

Toshiaki Yamauchi

Taishi Takano

Yoshimitsu Ohtaka

Tsutomu Uehara

Koichi Tsunemi

Yukihiro Fujikura

Yukihiro Osugi

Steven M Rice

Yuichi Hori

Hiroki Takano

Shinjiro Ueda

Miho Takigawa

In an image forming apparatus, a developer agitation member has a mechanism to vary its driving force, and the driving force of the developer agitation member is changed by a control unit according to the information of the number of times of image formation from a counter.

Image forming apparatus and method for forming image

Image forming histories when decolorization toner is used by a first counter or a second counter and when ordinary toner is used are counted respectively, and image forming histories of a decolorization developing device and an ordinary developing device are counted by a third counter or a fourth counter, and life control is executed for expendables, and adjustment of process conditions is controlled.

Image forming method and image forming apparatus including decolorization counter and ordinary counter

A toner is formed of toner particles including a polyester resin as a principal component, and at least a colorant and a charge control agent, and externally added inorganic fine particles and organic fine particles. The toner has a volume-average diameter of 4 to 10 &#x3bc;m, contains the charge control agent at 0.1 to 1.5%, and has an acid value of 2 to 33 mgKOH/g. The charge control agent exhibits a number-basis isolation percentage of at most 10% with respect to the toner particle. The charge control agent, the inorganic fine particles and organic fine particles exhibit number-basis isolation percentages from the toner particles satisfying a following relationship: 30%&#x3e;inorganic fine particles&#x3e;organic fine particles&#x3e;charge control agent&#x3e;0%.

Toner

A developing agent comprising color toners and a cyan toner, the color toners including a yellow toner, a magenta toner, and a black toner, wherein the black toner comprises a binder resin containing a crystalline polyester resin, and the yellow toner, the magenta toner and the cyan toner each comprise a binder resin containing no crystalline polyester resin.

Developing agent

Of developing agents each having a binder containing a polyester resin having an acidic value, wax having a softening point higher than that of the binder, and wax having a softening point lower than that of the binder, the acidic value of a black developing agent is made higher than that of a color developing agent.

Developing agent and image forming apparatus using the same

The invention provides a developing agent that includes color toners and a black toner. The color toners include a yellow toner, a magenta toner and a cyan toner. Each of the yellow toner, the magenta toner and the cyan toner contains, as a binder resin, a mixture of an H form of polyester mainly containing higher molecular components polyester, and an L form of polyester mainly containing lower molecular components of polyester. The black toner contains, as a binder resin, a mixture of an H form of polyester mainly containing higher molecular components of polyester, and an L form of polyester mainly containing lower molecular components polyester, and a crystalline polyester resin.

Disclosed is a developing agent using a binder resin including a styrene-acrylic-series resin, a crystalline polyester resin, a first wax having a melting point higher than the softening point of the crystalline polyester resin, and a second wax having a melting point lower than the softening point of the crystalline polyester resin.

A binder resin includes a first polyester resin having a high softening point Sp, a second polyester resin having a softening point Sphigher than the softening point Sp, a first wax having a melting point Mphigher than the softening point Sp, and a second wax having a melting point Mplower than the softening point Sp

Toner comprises rutile/anatase mixed crystal titanium oxide that is externally added to toner particles containing binder resin and coloring agents and hydrophobic processed, and hydrophobic silica externally added to the toner particles.

Toner, developer and methods for manufacturing toner and developer

An erasable image forming material includes a color former, a developer, a binder resin, and a polymer decolorizer having an electron donating group capable of physically or chemically adsorbing the developer. This polymer decolorizer is, e.g., a polymer compound having a sugar skeleton, representatively starch. This image forming material can form sharp images and erase images by heat or a solvent to achieve a good erased state.

Erasable image forming material

A developing agent exhibiting satisfactory negative charging characteristics can be obtained by allowing the developing agent to contain a toner, which contains a predetermined 2:1 type metal complex salt dye as a charge control agent or as a coloring agent, and carrier particles represented by general formula (MO).sub.X (Fe.sub.2 O.sub.3).sub.Y, obtained by using a kneaded mixture containing predetermined 2:1 type metal complex salt compound particles and a binder resin to have an average particle diameter of 0.2 .mu.m or less, or by allowing a binder resin to contain in advance a low molecular weight wax in manufacturing a developing agent containing a predetermined 2:1 type metal complex salt compound.

A substantially chromium-free toner composition which comprises, as a negative charge control agent, one or more complexes of Formula 1: ##STR1## including other acceptable forms of such complex, in which: X+ is H+, Na+ or mixtures thereof; M is Fe or Co; R.sup.1 is sulphonyl or sulphamoyl, substituted by one or more C.sub.1-4 alkyl; and R.sup.2 is carboxy or phenylcarbamoyl, optionally substituted by one or more C.sub.1-4 alkyl; but when R.sub.1 is methylsulphonyl, R.sup.2 is not carboxy.

Toner compositions and use

A toner comprises a first particle having a predetermined volume average diameter and including thermoplastic binding resin and a colorant mixed into the thermoplastic binding resin to apply a color thereto. Wax of a second particle whose volume average diameter is considerably smaller than that of the first particle, is attached to the first particle by mechanical pressure. A nonmagnetic particle of a third particle is attached to the wax. The volume average diameter of the third particle is considerably smaller than that of the second particle. The attachment of the nonmagnetic particle decreases the area of an exposed surface of the wax, thereby preventing the wax from being attached to other wax and preventing the wax from contacting another toner.

Growing community of inventors

Tokyo, Japan

Shuitsu Sato