Ricoh Company, Ltd.

Tomoki Murayama

Junichi Awamura

Shingo Sakashita

Satoshi Kojima

Daisuke Inoue

Tsuneyasu Nagatomo

Masaya Fukuda

Hiroshi Yamashita

Hiroshi Hosokawa

Masana Shiba

Rintaro Takahashi

Masaki Watanabe

Ryota Inoue

Yoshitsugu Kimura

Kenji Kikuchi

Shinji Tamaki

Shunji Katoh

Hiroshi Ikeguchi

Naohiro Watanabe

Michiharu Suzuki

Chihiro Kikuchi

Osamu Uchinokura

Takahiro Honda

Mamoru Hozumi

Akio Takei

Ryuuta Yoshida

Daisuke Misawa

Yuichi Shirasu

A toner including a binder resin, wherein a toner extract obtained by drying an extraction liquid obtained through Soxhlet extraction of the toner with tetrahydrofuran (THF) has glass transition temperature Tg in a range of from 35&#xb0; C. through 55&#xb0; C., and a moisture-content change rate of the toner extract before and after leaving the toner extract to stand for 3 days in an environment of 40&#xb0; C. and 70% RH is 0.5% or less, and wherein a specific-surface-area change rate of the toner before and after leaving the toner to stand for 3 days in an environment of 40&#xb0; C. and 70% RH is in a range of from 15% through 50%.

Toner, toner stored unit, and image forming apparatus

A toner comprising a binder resin and a release agent, wherein the toner has a difference of 30 or less between a maximum value and a minimum value among peak intensities in a range of Molecular weight M&#xb1;300 where Molecular weight M is a molecular weight selected from a range of from 300 through 5,000 in a molecular weight distribution of tetrahydrofuran (THF)-soluble components in the toner as measured by gel permeation chromatography (GPC), and wherein the peak intensities are defined as relative values assuming a maximum peak value in molecular weights of 20,000 or less is 100, in a molecular weight distribution curve taking an intensity as a vertical axis and a molecular weight as a horizontal axis as measured by GPC.

A toner including a binder resin and a release agent, wherein the toner has a component soluble in a 50% by mass aqueous methanol solution in an amount of 0.10% by mass to 0.60% by mass, and wherein the toner has a flowing-out beginning temperature (Tfb) of 55.0&#xb0; C. to 100.0&#xb0; C. as determined by a flowtester method.

Toner, image forming apparatus, and process cartridge

To provide a toner, which contains silica particles containing first silica particles, and second silica particles, wherein the toner is a toner produced by depositing the silica particles on surfaces of base particles, the first silica particles have an average primary particle diameter of 75 nm to 250 nm, the second silica particles have an average primary particle diameter of 10 nm to 50 nm, a mass ratio of the first silica particles to the base particles is 0.010 to 0.040, a mass ratio of the second silica particles to the base particles is 0.005 to 0.030, a liberation ratio of the silica particles from the toner by a ultrasonic vibration method is 5% by mass to 20% by mass, and an amount of particles having primary particle diameters of 30 nm or smaller in the silica particles librated from the toner by the ultrasonic vibration method is 20% by number or less.

Toner, developer and image forming apparatus

Provided is an electrostatic charge image developing toner, including: toner base particles including a polyester resin as a binder resin; and an external additive on the surface of the toner base particles. The external additive includes silica. The silica is produced by sol-gel method, and is aspherical. The percentage of change in the specific surface area of the toner when it is stored under high-temperature, high-humidity conditions is from 25% to 45%.

Electrostatic charge image developing toner

An image forming apparatus, including: photoconductor; charging unit; exposing unit; developing unit containing toner; transfer unit; and fixing unit, wherein the toner includes external additive and base particles containing binder resin, colorant, and release agent, the toner has melt viscosity at 100&#xb0; C. of 500 Pa&#xb7;s to 8,000 Pa&#xb7;s and the release agent has melt viscosity at 100&#xb0; C. of 20 mPa&#xb7;s to 30 mPa&#xb7;s, the fixing unit includes fixing member that has roller or belt shape and contacts toner image transferred onto recording medium, and the fixing member includes release layer on surface thereof that is to be brought into contact with the toner image transferred onto the recording medium, and wherein the release layer satisfies the following expressions:45&#x2266;&#x3b8;1&#x2266;60, and10&#x2266;&#x3b8;1&#x2212;&#x3b8;2,

Image forming apparatus

A toner including: a binder resin containing a non-crystalline resin and a crystalline resin; a colorant; and, a releasing agent, wherein the releasing agent has a melting point of 55&#xb0; C. to 80&#xb0; C., and wherein the toner satisfies the following Expressions 1 and 2: (Expression 1): 20,000 Pa&#xb7;s&#x2266;G&#x2266;50,000 Pa&#xb7;s; and (Expression 2): (G/G)/(G/G) 1.00, where Gis a storage modulus, Gis a loss modulus, Gis a storage modulus and Gis a loss modulus, and the storage modulus Gand the loss modulus Gare measured at 80&#xb0; C. when the toner is heated from 70&#xb0; C. to 150&#xb0; C. and the storage modulus Gand the loss modulus Gare measured at 80&#xb0; C. when the toner heated to 150&#xb0; C. is cooled to 70&#xb0; C.

A toner housing container includes: a container body housing a toner; a conveying portion; a pipe receiving port; and an uplifting portion. Flow rate index of the toner measured by powder rheometer and represented by 'flow rate index=(total energy at a rotation speed of 10 mm/s)/(total energy at a rotation speed of 100 mm/s)' is in a range of '1.8&#x2266;flow rate index&#x2266;6.5'. Container body includes protruding portion protruding from container body interior side of container opening portion toward one end of container body. Uplifting portion includes: uplifting wall surface extending from container body internal wall surface toward protruding portion; and curving portion curving to conform to protruding portion. When the toner housing container is mounted on the toner conveying device, the protruding portion is present between the curving portion and the toner receiving port of the conveying pipe being inserted.

Toner housing container and image forming apparatus

A developing device, including: a developer bearing member, which is disposed opposite to an electrostatic latent image bearing member and which bears thereon a developer for developing an electrostatic latent image formed on the electrostatic latent image bearing member and conveys the developer to a developing region, wherein the developer includes a toner and a carrier, the toner containing: a toner base containing a binder resin and a colorant; and an external additive, wherein the external additive contains coalescent particles each made up of a plurality of coalescing primary particles, and wherein a work function Wc of the carrier and a work function Ws of the developer bearing member satisfy a relationship of the following formula (1):&#x2267;0.4 eV&#x2003;&#x2003;(1).

Developing device that suppresses hysteresis

Toner housing container includes: container body mountable on toner conveying device and housing toner supplied into toner conveying device; conveying portion provided in container body and conveying toner from longer direction one end of container body to other end at which container opening portion is provided; pipe receiving port provided at container opening portion and receiving conveying pipe fixed to toner conveying device; and uplifting portion to move toner conveyed by conveying portion toward toner receiving port of conveying pipe. Toner has loose apparent density of 0.28 g/cmto 0.53 g/cm. Container body includes protruding portion protruding from container body interior side of container opening portion toward one end. Uplifting portion includes uplifting wall surface extending from internal wall surface of container body toward protruding portion, and curving portion curving to conform to protruding portion. Protruding portion is present between curving portion and toner receiving port of inserted conveying pipe.

A toner obtained by a method for producing a toner, which includes dissolving or dispersing in an organic solvent a toner material containing at least a binder resin, and a dispersion liquid of a crystalline polyester resin, so as to prepare a solution or dispersion liquid of the toner material, emulsifying or dispersing the solution or dispersion liquid of the toner material in an aqueous medium, so as to prepare an emulsion or dispersion liquid, and removing the organic solvent from the emulsion or dispersion liquid, wherein the crystalline polyester resin is localized near a surface of the toner.

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

A method for producing an electrophotographic toner including forming a toner base particle by emulsifying or dispersing a solution or dispersion of a toner material comprising a colorant, and any one of a binder resin and a binder resin precursor in an aqueous medium, and adding crystalline organic fine particles having an acid value of 20 mgKOH/g to 80 mgKOH/g into the aqueous medium, before, during or after the forming so as to attach the crystalline organic fine particles onto a surface of the toner base particle.

Growing community of inventors

Kanagawa, Japan

Tomoki Murayama