Ricoh Company, Ltd.

Akihiro Kotsugai

Shinya Nakayama

Satoshi Mochizuki

Hisashi Nakajima

Akiyoshi Sabu

Tomoyuki Ichikawa

Hideki Sugiura

Yasuaki Iwamoto

Yasuo Asahina

Osamu Uchinokura

Toyoshi Sawada

Hiroshi Yamashita

Masami Tomita

Hiroaki Takahashi

Hiroshi Yamada

Kimitoshi Yamaguchi

Koichi Sakata

Ryota Inoue

Masanori Suzuki

Tomoko Utsumi

Shingo Sakashita

Masayuki Ishii

Masahide Yamashita

Fumihiro Sasaki

Yukiko Nakajima

Keiko Osaka

Junichi Awamura

Yoshihiro Moriya

Keiko Shiraishi

Kohki Katoh

Naoki Imahashi

Tsuyoshi Sugimoto

Hiroto Higuchi

Yohichiroh Watanabe

Hitoshi Iwatsuki

Hiroyuki Fushimi

Takuya Saito

Sonoh Matsuoka

Yohichiro Watanabe

Shigeru Emoto

Shinichiro Yagi

Toshiki Nanya

Naohito Shimota

Tomomi Suzuki

Takahiro Honda

Yasutada Shitara

Yoichiro Watanabe

Kenkichi Muto

Kohichi Sakata

Mituo Aoki

Mitsuo Aoki

Kazuhiko Umemura

Hiroshi Ikuno

Yoshitaka Yamauchi

Tsuneyasu Nagatomo

Motoharu Tanaka

Daiki Yamashita

Shinichi Wakamatsu

Hiromitsu Kawase

Koichi Katoh

Hachiro Tosaka

Hachiroh Tosaka

Ian Harpur

Naohito Bell Shine Takehara A-103 Shimota

Tomoyuki Dai6 Sumika Bldg 206 Ichikawa

Koichi Takashimahoncho M's 503 Sakata

Masami Pasco Grand Mansion Shinnumazu 302 Tomita

Shinya Grand River A 201 Nakayama

The present invention provides a toner which, despite its spherical shape, makes it possible to prevent an external additive from being embedded in the toner easily or by a load generating low stress, reduce variation in image density, maintain cleaning ability and transfer ability throughout its long-term use and obtain excellent image quality, and further, provides a two-component developer, an image forming method and an image forming apparatus with the use of the toner. There is a toner including: base particles including a colorant and a resin, and hard fine particles, wherein the base particles and the hard fine particles are mixed together, and protruding portions formed of fine organic resin particles which are different in composition from a resin contained as a main component in the base particles are provided on surfaces of the base particles.

Toner for developing latent electrostatic image, two-component developer, image forming method and image forming apparatus

The present invention provides an image forming toner including at least a linear polyester resin (b1) as a binder resin, wherein the linear polyester resin (b1) is obtained by reacting a polyester diol (b11) having a polyhydroxycarboxylic acid skeleton, with a polyester diol (b12) other than the polyester diol (b11) in the presence of a chain extending agent.

Image forming toner, image forming apparatus, image forming method, and process cartridge

An electrostatic image developing toner including a toner particle (C), wherein the toner particle (C) has a structure in which a resin particle (A) containing at least a first resin (a) or a coated film (P) containing the first resin (a) is attached to a surface of a resin-containing particle (B) containing a second resin (b), and wherein the resin (b) includes a polyhydroxycarboxylic acid skeleton, and the resin (a) is a polyester resin containing a polybasic acid and a polyhydric alcohol.

Electrostatic image developing toner, developer, image forming apparatus, image forming method, and process cartridge

A toner including: a first binder resin; a colorant; a releasing agent; and a crystalline organic compound, wherein the first binder resin contains an amorphous polyester resin (a) having a polyhydroxycarboxylic acid skeleton derived from optically active monomers in a part of a main chain of the amorphous polyester resin, and the polyhydroxycarboxylic acid skeleton has an optical purity X, calculated on the monomer basis, of 80% or less, and the optical purity X is determined from the equation,Optical Purity(%)=|(-form)&#x2212;(-form)|

Toner, developer, and image forming method

A toner including a binder resin comprising a resin (a) comprising a polyhydroxycarboxylic acid skeleton formed from an optically-active monomer. The polyhydroxycarboxylic acid skeleton has a weight average molecular weight of from 7,000 to 60,000. The binder resin comprises the polyhydroxycarboxylic acid skeleton in an amount of from 10 to 90% by weight. The optical purity X (%) of the polyhydroxycarboxylic acid skeleton represented by the following formula is 80% or less:(%)=|(-isomer)&#x2212;(-isomer)|wherein X(L-isomer) and X(D-isomer) represent molar ratio (%) of L-isomer and D-isomer of the optically-active monomer, respectively.

Toner, color toner set, developer, process cartridge, and image forming method

To provide a toner including: a resin particle (C) containing a first resin (a1), a second resin (a2), and a resin particle (B) to a surface of which the first resin (a1) and the second resin (a2) are attached, wherein the first resin (a1) and the second resin (a2) have mutually different glass transition temperatures, and wherein the resin particle (B) contains a third resin (b) having an amorphous polyhydroxycarboxylic acid skeleton.

Toner, developer, image forming method and image forming apparatus

A toner including a colorant, a thermoplastic resin (a) comprising an amorphous polyester resin having a main chain having a polyhydroxycarboxylic acid skeleton, and a thermoplastic resin (b) is provided. The toner is manufactured by a method including mixing the colorant with the thermoplastic resin (a) to prepare a preliminary mixture, and mixing the preliminary mixture with the thermoplastic resin (b).

Toner, and developer, toner cartridge, image forming apparatus, process cartridge and image forming method using the same

The toner includes a binder resin; a release agent; a colorant; and a dispersing resin configured to disperse the release agent. The dispersing resin includes a polyhydroxycarboxylic acid unit obtained from an optically active monomer. The polyhydroxycarboxylic acid unit has an optical purity of not greater than 80%, wherein the optical purity is defined as the absolute value of difference between the mole percentage of a L-monomer in the optically active monomer and the mole percentage of a D-monomer in the optically active monomer.

Toner, developer, and image forming method and apparatus using the toner

There is provided a method for producing a carrier, which includes depositing a resin coating layer on the surface of a magnetic material; adding a treatment agent for a conductor precursor to the resin coating layer so as to treat the resin coating layer with the treatment agent; and exposing the treatment agent-added resin coating layer to a conductor precursor in a supercritical or subcritical fluid so as to form a conductor in the resin coating layer.

Carrier, production method thereof, developer and image forming method

An image forming apparatus including: a latent electrostatic image bearing member, a charging unit, an exposing unit, a developing unit, a transfer unit, and a fixing unit, wherein the toner contains at least a binder resin and a colorant, the binder resin contains a polyester resin obtained by polycondensation of an alcohol component with a carboxylic acid component containing a rosin compound, the amount of the rosin compound contained in the carboxylic acid component is 5% by mass or more based on the total mass of the alcohol component and carboxylic acid component, and the amount of an abietic acid contained in the toner is 1% by mass or less.

Toner, image forming apparatus, image forming method, and process cartridge

A carrier for electrophotographic developer, including a core material; and a layer comprising a binder resin, located overlying the core material, wherein the binder resin includes a segment including one or more polymerizable vinyl monomers as a structural unit; and another segment including a partial cleavage structure of polyhedral oligomeric silsesquioxane and/or another partial cleavage structure of polyhedral oligomeric silsesquioxane as a structural unit.

Carrier for electrophotography and two-component developer

The present invention provides a toner containing at least a binder resin, a releasing agent, and a colorant, wherein the binder resin contains at least a polyester resin (A) having a softening point Tm (A) of 120&#xb0; C. to 160&#xb0; C., a polyester resin (B) having a softening point Tm (B) of 80&#xb0; C. or more and less than 120&#xb0; C. and a composite resin (C) containing a condensation polymerization monomer and an addition polymerization monomer, at least any one of the polyester resins (A) and (B) is a polyester resin prepared by condensation-polymerizing an alcohol component substantially composed of only aliphatic alcohol with a carboxylic acid component, and 65% or more of the alcohol component is 1,2-propanediol.

Toner, image forming apparatus, image forming method, and process cartridge using the toner

To provide a toner produced by emulsifying or dispersing in an aqueous medium particles containing at least polyester resin particles and by aggregating the polyester resin particles, wherein the polyester resin particles contain a polyester resin, the polyester resin is produced by condensation polymerization of an alcohol component containing 65 mol % or more 1,2-propanediol in a dihydroxy alcohol component and a carboxylic acid component containing purified rosin, and the softening point of the polyester resin is 80&#xb0; C. or more and less than 120&#xb0; C., and wherein the toner comprises a colorant and a releasing agent.

Toner, as well as image forming apparatus and image forming method using the same

A toner that is excellent in low-temperature fixing property, offset resistance, storage stability, charge rising property, charge stability with time and pulverizability and allows for forming high-quality images over a long period of time. The toner contains at least a binder resin, a colorant and a charge controlling agent, wherein the charge controlling agent contains an aromatic oxycarboxylic acid metal compound having a trivalent or more central metal, the binder resin comprises a polyester resin (A) having a softening point Tm (A) of 120&#xb0; C. to 160&#xb0; C. and a polyester resin (B) having a softening point Tm (B) of 80&#xb0; C. to less than 120&#xb0; C., and at least any one of the polyester resins (A) and (B) contains 1,2-propane diol at 65 mol % or more in a divalent alcohol component and can be obtained by condensation polymerizing an alcohol component substantially composed of only an aliphatic alcohol with a carboxylic acid component.

Toner, image forming apparatus using the same, image forming method using the same, and process cartridge

An image forming apparatus including a charging unit, an exposing unit, a developing unit, a transferring unit, and a fixing unit. A toner containing a colorant and a binder resin which contains a polyester resin (A) and a polyester resin (B) having a softening point 10&#xb0; C. or more higher than that of the polyester resin (A); the polyester resin (A) is a (meth)acrylic acid-modified rosin derived resin having a polyester unit obtained by polycondensation of an alcohol component, which contains 65 mol % or more of 1,2-propanediol in a dihydric alcohol component, and a carboxylic acid component containing a (meth)acrylic acid-modified rosin; the polyester resin (B) is a purified rosin derived resin having a polyester unit obtained by polycondenstation of an alcohol component, which contains a total of 70 mol % or more of 1,2-propanediol and 1,3-propanediol in a dihydric alcohol component, and a carboxylic acid component containing purified rosin.

Image forming apparatus, image forming method, and process cartridge

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Numazu, Japan

Akihiro Kotsugai