Ricoh Company, Ltd.

Saori Yamada

Hisashi Nakajima

Masashi Nagayama

Mariko Takii

Koichi Sakata

Hitoshi Iwatsuki

Kimitoshi Yamaguchi

Hiroyuki Kishida

Toyoaki Tano

Minoru Masuda

Mitsuo Aoki

Kazumi Suzuki

Yoshitaka Sekiguchi

Yoshitaka Yamauchi

Yu Naito

Shinya Nakayama

Yutaka Takahashi

Shigenori Yaguchi

Shinya Hanatani

Shinya Nakagawa

Hyo Shu

Haruki Murata

Masahiro Seki

Kei Niwayama

Kohsuke Miyazaki

Hiroshi Yamashita

Hiroshi Hosokawa

Kenji Kikuchi

Shinji Tamaki

Toyoshi Sawada

Shunji Katoh

Yoshimichi Ishikawa

Hiroshi Ikeguchi

Michiharu Suzuki

Hiroshi Tohmatsu

Akihiro Kaneko

Tohru Suganuma

Yoshihiro Murasawa

A carrier for forming an electrophotographic image is provided. The carrier includes a core particle comprising a manganese-based ferrite particle having an apparent density of from 2.0 to 2.2 g/cmand a magnetization of from 44 to 52 emu/g in a magnetic field of 500 Oe; and a coating layer coating a surface of the core particle. The coating layer contains a carbon black, an inorganic particle A, and an inorganic particle B. The inorganic particle A and the carbon black each have a concentration gradient in a thickness direction of the coating layer. A concentration of the inorganic particle A increases toward a surface of the coating layer, and a concentration of the carbon black decreases toward the surface of the coating layer.

Carrier, developer, method, and apparatus for forming electrophotographic image, and process cartridge

A toner, where a diffraction peak of the toner as measured by X-ray diffraction spectroscopy is present at least in a region where 2&#x3b8; is from 20&#xb0; through 25&#xb0;, and a difference between Tg1 and Tg2 is 10&#xb0; C. or less, where Tg1 is a glass transition temperature of the toner, as observed in a last heating step, when heating and cooling are performed on the toner by means of a differential scanning calorimeter (DSC) under the heating and cooling conditions 1 defined in the specification, and Tg2 is a glass transition temperature of the toner, as observed in a last heating step, when heating and cooling are performed on the toner by means of the differential scanning calorimeter (DSC) under the heating and cooling conditions 2 defined in the specification.

Toner, image forming apparatus, and toner stored unit

A toner for electrophotography, which contains a binder resin, and a release agent, wherein a maximum value of loss tangent of the toner at 95&#xb0; C. to 115&#xb0; C. is 8 or greater, as a viscoelasticity of the toner is measured, where the loss tangent is represented by the following formula: Loss tangent (tan &#x3b4;)=loss elastic modulus (G&#x2033;)/storage elastic modulus (G').

Toner for electrophotography, image forming method, and process cartridge

A carrier for a developer of an electrostatic latent image, the carrier including: core particles having magnetism; and a coating layer coating a surface of each of the core particles, wherein the coating layer includes two or more kinds of inorganic particles, at least one kind of inorganic particles among the two or more kinds of inorganic particles is inorganic particles A having conductivity and a peak particle diameter of from 300 nm through 1,000 nm, and surface roughness of the carrier calculated by Formula 1 below is from 1.10 m/g through 1.90 m/g,C&#x2212;F&#x2003;&#x2003;Formula 1where C is a BET specific surface area (m/g) of the carrier and F is a BET specific surface area (m/g) of the core particles.

Carrier for developer of electrostatic latent image, developer, and image forming apparatus

Toner contains a binder resin, a releasing agent, and a tri- or higher metal salt, wherein the toner has a weight average molecular weight (Mw) of from 7,000 to 10,000, a ratio of the weight average molecular weight (Mw) to a number average molecular weight (Mn) of 5 or less, and an acid value of from 6 mgKOH/g to 12 mgKOH/g, wherein the binder resin is a polyester resin, wherein the releasing agent is a monoester wax.

Toner, image forming method, and process cartridge

Carrier for image forming includes a core material particle including a magnetic material and a coating layer disposed on the surface of the core material particle, the coating layer including a resin, carbon black, an inorganic particulate A, and an inorganic particulate B. The carbon black has a concentration gradient along a thickness direction of the coating layer with a concentration from high to low toward a surface of the coating layer while the inorganic particulate A has a concentration gradient along a thickness direction of the coating layer with a concentration from low to high toward the surface of the coating layer. The volume ratio of the carbon black is 0-30 percent at a depth range of 0.0-0.1 &#x3bc;m from the surface of the coating layer. The inorganic particulate A is electroconductive with a powder specific resistance of 200 &#x3a9;&#xb7;cm or less.

Carrier, developing agent, image forming apparatus, image forming method, replenishment toner, and process cartridge

A white toner has a first temperature range not less than 25&#xb0; C. in which 60&#xb0; glossiness is 10 or less between a fixable minimum temperature and a fixable maximum temperature thereof. The white toner has a second temperature range not less than 25&#xb0; C. in which 60&#xb0; glossiness is from 30 to 60 therebetween.

White toner, and image forming method and image forming apparatus using the white toner

A toner housing container includes a container body housing a toner; a conveying portion conveying the toner from one end of the container body, in a longer direction of the container body, to its other end at which a container opening portion is provided; a pipe receiving port receiving a conveying pipe fixed to a toner conveying device; and an uplifting portion moving the toner toward a toner receiving port of conveying pipe. Such toner has a molecular weight distribution having a peak in a range of 10to 10, and has C/R of from 0.03 to 0.55 between peak height C attributed to crystalline polyester resin and R attributed to non-crystalline resin when measured by FT-IR after stored at 45&#xb0; C. for 12 hours.

Toner housing container and image forming apparatus

A toner, including: a binder resin; and a colorant, wherein the binder resin contains: a crystalline polyester resin (A); a non-crystalline resin (B); and a composite resin (C), where the composite resin (C) contains a condensation polymerization resin unit and an addition polymerization resin unit, wherein the toner contains chloroform insoluble matter in an amount of 1% by mass to 30% by mass, wherein the toner has a molecular weight distribution having a main peak in a range of 1,000 to 10,000 and a half width of 15,000 or less, where the molecular weight distribution is obtained through gel permeation chromatography (GPC) of tetrahydrofuran soluble matter of the toner, and wherein the toner has an endothermic peak in a range of 90&#xb0; C. to 130&#xb0; C. in measurement through differential scanning calorimetry (DSC).

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

A toner for forming an electrophotographic image is provided, wherein the toner includes at least four types of binder resins,

Toner for forming electrophotographic image, method for manufacturing toner for forming electrophotographic image, image forming method, and process cartridge

A carrier for use in a two component developer for developing an electrostatic latent image is provided. The carrier includes a particulate core material; and a cover layer located on a surface of the core material and including a silicone resin and barium sulfate. The cover layer includes Ba and Si at an atomic ratio of from 0.01 to 0.08 as determined by X-ray photoelectron spectroscopy.

Carrier, developer using the carrier, and developing device, image forming method, image forming apparatus and process cartridge using the developer

An electrostatic image developing toner including a resin fine particle, and a toner material containing a polyester-based resin, wherein the electrostatic image developing toner is obtained by dissolving and/or dispersing the toner material containing the polyester-based resin in an organic solvent to prepare a toner material liquid, and dispersing the toner material liquid in an aqueous solvent containing the resin fine particle, and wherein the polyester-based resin contains a polyester resin obtained by polycondensation of an alcohol component with a carboxylic acid component containing a modified purified-rosin.

Toner, developer, toner container, process cartridge, image forming method, and image forming apparatus

A toner including a crystalline polyester resin (A), an amorphous resin (B), and a composite resin (C) having a condensation polymerization resin unit and an addition polymerization resin unit is provided. A molecular weight distribution of the toner based on THF-soluble contents thereof has a main peak within a molecular weight range from 1,000 to 10,000 and a half bandwidth of the main peak is 15,000 or less. The molecular weight distribution is determined by gel permeation chromatography. The toner includes chloroform-insoluble contents. A ratio C/R of the toner is within a range from 0.03 to 0.55. C and R represent heights of spectrum peaks specific to the crystalline polyester resin (A) and the amorphous resin (B), respectively, determined by a Fourier transform infrared spectroscopic attenuation total reflection method after the toner is stored in a thermostatic chamber at 45&#xb0; C. for 12 hours.

The developing method includes developing an electrostatic latent image on an image bearing member with a two-component developer including a toner and a carrier and born on at least one developer bearing member, whose surface moves at a linear speed of from 300 mm/sec to 2,000 mm/sec. The carrier includes a particulate core material; and a cover layer located on a surface of the core material and including a crosslinked material obtained by crosslinking a resin including a first unit having a specific tris(trialkylsiloxy) silyl group and a second unit having a specific alkoxysilyl group having a crosslinking ability. Each of the first unit and the second unit is included in the resin in a molar ratio of from 0.1 to 0.9 based on all the units included in the resin.

Developing method and image forming method

An image forming method including forming an electrostatic latent image on an image bearing member; developing the electrostatic latent image using a color toner and a transparent toner to form a color toner image and a transparent toner image thereon; transferring the color toner image and the transparent toner image to a recording material; and fixing the color toner image and the transparent toner image on the recording material. The color toner includes a polyester resin and a colorant, and the loss tangent of the color toner has a maximum peak at a temperature of from 80&#xb0; C. to 160&#xb0; C., and is not greater than 3 at the maximum peak. The transparent toner includes a crystalline polyester resin, and the loss tangent of the transparent toner has a maximum peak at a temperature of from 80&#xb0; C. to 160&#xb0; C., and is not less than 3 at the maximum peak.

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Shizuoka, Japan

Saori Yamada