Ricoh Company, Ltd.

Shingo Sakashita

Akiyoshi Sabu

Atsushi Yamamoto

Yoshihiro Moriya

Tomoki Murayama

Tatsuya Morita

Satoshi Kojima

Suzuka Amemori

Masaya Fukuda

Hiroshi Yamashita

Tsuyoshi Sugimoto

Hiroshi Hosokawa

Takuya Seshita

Chiaki Tanaka

Ryota Inoue

Yukiko Nakajima

Shinya Nakayama

Masahide Yamada

Akihiro Kotsugai

Kazumi Suzuki

Junichi Awamura

Hideyuki Santo

Rintaro Takahashi

Keiko Osaka

Tsuneyasu Nagatomo

Masayuki Ishii

Yoshitaka Yamauchi

Masana Shiba

Daiki Yamashita

Daisuke Inoue

Kenji Kikuchi

Naohiro Watanabe

Shinji Tamaki

Toyoshi Sawada

Shunji Katoh

Hiroshi Ikeguchi

Michiharu Suzuki

Taichi Nemoto

Daisuke Asahina

Chihiro Kikuchi

Yasuo Katano

Yohichiroh Watanabe

Satoshi Mochizuki

Takahiro Honda

Satoyuki Sekiguchi

Yasutada Shitara

Takayuki Itoh

Masaki Yoshino

Keiji Makabe

Azumi Miyaake

Akio Takei

Hisao Kurosu

Daisuke Misawa

Hiroshi Endoh

Yoshitsugu Kimura

Tomoko Kino

Ayumi Satoh

Suzuka Amerori

A toner includes a binder resin; a release agent; and two or more inorganic fine particles as external additives. At least one of the inorganic fine particles is silica. When an ultrasonic oscillation is applied to a dispersion including the toner and a dispersant and a rate of the silica releasing from the toner is 20% based on total silica, an application energy of the ultrasonic oscillation is from 8 to 14 kJ, and from 70 to 130 kJ when the rate of the silica releasing from the toner is 50%.

Toner, developer, toner housing 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.

Toner, toner stored unit, and image forming apparatus

A toner including at least a crystalline resin as a binder resin, wherein a tetrahydrofuran soluble content of the toner includes 5.0% or more as a peak area of a component having a molecular weight of 100,000 or greater in a molecular weight distribution measured by gel permeation chromatography, and the tetrahydrofuran soluble content of the toner has a weight-average molecular weight of 20,000 to 60,000.

Toner, developer using the toner, image forming apparatus

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

A toner, including: a crystalline resin; a non-crystalline resin; and a colorant, wherein the toner has a sea-island structure which includes a sea containing the crystalline resin and an island containing the non-crystalline resin and the colorant, wherein the island is 1.0 &#x3bc;m or less in domain diameter, and wherein the toner is 1.7&#xd7;10Pa or less in storage elastic modulus at 160&#xb0; C.

Toner, method for producing the toner, two-component 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 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.

An electrostatic image forming toner including: toner base particles each containing at least a colorant, a binder resin, and a releasing agent, wherein the binder resin contains a non-crystalline polyester resin A and a crystalline polyester resin B, wherein a ratio of B/(A+B)&#xd7;100 is 10 or more but less than 50 where (A+B) is a total mass of the non-crystalline polyester resin A and the crystalline polyester resin B and 'B' is a mass of the crystalline polyester resin B, and wherein the toner base particles have a TMA compression deformation amount (TMA %) of 10% or less which is measured at 50&#xb0; C. and a relative humidity of 90%.

Electrostatic image forming toner and developer

A toner includes a binder resin, a coloring agent, and a releasing agent containing two or more kinds of alkyl monoester compounds having a different number of carbon atoms in a range of from 30 to 50 carbon atoms. The toner has a crystallinity of 10% or more as measured by x-ray diffraction and/or the binder resin is a crystalline resin in an amount of 50% by weight or more of the binder resin. The two or more kinds of alkyl monoester compounds include a component A accounting for the largest amount ranging from 30% by weight to less than 50% by weight of the releasing agent and a component B accounting for the second largest amount ranging from 10% by weight to less than 50% by weight of the releasing agent.

Toner, development agent, and image forming apparatus using the same

An electrophotographic toner, including: a binder resin; a colorant; and an organically-modified layered inorganic mineral, wherein the binder resin contains 50% by mass or more of a crystalline resin relative to the binder resin, and the crystalline resin contains a resin having a sulfonic acid group, and wherein an amount of the sulfonic acid group is 0.1% by mass to 2.0% by mass relative to the resin having the sulfonic acid group.

Electrophotographic toner, developer, and image forming apparatus

Growing community of inventors

Shizuoka, Japan

Shingo Sakashita