Ricoh Company, Ltd.

Yoshitaka Yamauchi

Kazumi Suzuki

Taichi Nemoto

Hisashi Nakajima

Yoshihiro Moriya

Yukiko Nakajima

Daiki Yamashita

Masahide Yamada

Akiyoshi Sabu

Keiji Makabe

Akihiro Kaneko

Chiaki Tanaka

Suzuka Amemori

Tatsuya Morita

Yu Naito

Namie Suzuki

Saori Yamada

Masana Shiba

Azumi Miyaake

Kohtaroh Ogino

Masashi Nagayama

Shingo Sakashita

Daisuke Asahina

Rintaro Takahashi

Hiroshi Yamashita

Tsuyoshi Sugimoto

Ryota Inoue

Satoyuki Sekiguchi

Keiko Osaka

Atsushi Yamamoto

Shinya Nakayama

Akihiro Kotsugai

Katsunori Kurose

Yoshitaka Sekiguchi

Hideyuki Santo

Shinji Ohtani

Hyo Shu

Takeshi Sako

Idzumi Okajima

Shunsuke Mori

Keishi Mizuno

Jyun Ishiduka

Nobuyuki Mase

Teruyuki Suzuki

Ayaka Mori

A toner includes: a crystalline polyester resin; and a partially hydrogenated petroleum resin. A hydrogenation rate of the partially hydrogenated petroleum resin is from 30% through 70%. An amount of the partially hydrogenated petroleum resin relative to the toner is from 1% by mass through 15% by mass.

Toner

A toner including a strontium titanate powdery material as an external additive, the strontium titanate powdery material including Si-containing particles on a surface of the strontium titanate powdery material, the Si-containing particles having a number average circle equivalent diameter of 5 nm or more but 15 nm or less.

Toner, toner stored container, developer, developing device, process cartridge, and image forming apparatus

Provided is a toner including toner particles, each toner particle includes: a base particle including a binder resin; and external additive particles, wherein the external additive particles include particles each having an equivalent circle diameter of 10 nm or greater, a volume average particle diameter of the particles each having an equivalent circle diameter of 10 nm or greater is 80 nm or greater but 140 nm or less, and a ratio (circumscribed circle area/particle area) of a circumscribed circle area of the particle having an equivalent circle diameter of 10 nm or greater to a particle area of the particle having an equivalent circle diameter of 10 nm or greater is 1.60 or greater but 2.60 or less.

Toner, toner stored unit, and image forming apparatus

A toner is provided. The toner comprises a binder resin, a release agent, and a function imparting agent comprising a fatty acid amide having a melting point of from 110 to 160 degrees C. When the toner is heated by a differential scanning calorimeter, the toner exhibits no endothermic peak within a temperature range of &#xb1;20 degrees C. of a temperature at a highest endothermic peak derived from the fatty acid amide.

Toner, image forming apparatus, image forming method, and toner accommodating unit

A toner is provided. The toner includes at least two types of polyester resins and a release agent. When the toner is subjected to a dynamic viscoelasticity measurement at a frequency of 6.28 rad/sec to obtain a temperature-dependent curve of loss tangent (tan &#x3b4;), and the temperature-dependent curve is differentiated one time with temperature, a resulting curve has a maximum value of 0.07 or more and a minimum value of 0.025 or less within a temperature range of from 85&#xb0; C. to 110&#xb0; C. When the toner is subjected to a differential scanning calorimetry (DSC), an endothermic amount measured in a first temperature rising in the DSC is 3.5 J/g or less within a temperature range of from 85&#xb0; C. to 120&#xb0; C.

Toner, developer, toner storage unit, image forming apparatus, image forming method, and method for producing printed matter

A toner is provided. The toner comprises mother particles and an external additive covering the mother particles. The mother particles comprise a binder resin, and the external additive comprises inorganic particles. The inorganic particles comprise small-size inorganic particles having an equivalent circle diameter of from 30 to 70 nm and large-size inorganic particles having an equivalent circle diameter of from 150 to 200 nm and a circularity of 0.85 or more. The large-size inorganic particles are 20 to 70 in number per 100 &#x3bc;mimage area of the toner observed with a field-emission scanning electron microscope.

Toner, image forming apparatus, image forming method, and toner storage unit

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 is provided. The toner comprises a binder resin comprising a polyester resin, a release agent comprising an ester wax, and a wax dispersing agent comprising a hybrid resin. The hybrid resin comprises a condensation polymerization resin unit and an addition polymerization resin unit. The condensation polymerization resin unit comprises a condensation polymerization product of an aromatic alcohol component and a carboxylic acid component, and the carboxylic acid component comprises an aliphatic dicarboxylic acid having 9 to 14 carbon atoms. The addition polymerization resin unit comprises an addition polymerization product of a styrene monomer.

Toner and image forming method

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 toner for electrophotography, the toner including an amorphous polyester resin, an addition polymerization-based resin, and wax that is ester wax or carnauba wax, wherein the toner satisfies relationships represented by Formula 1 and Formula 2 below,&#x2003;&#x2003;(Formula 1)|&#x2003;&#x2003;(Formula 2)where SPr is a value of a solubility parameter of the amorphous polyester resin, SPw is a value of a solubility parameter of the wax, and SPd is a value of a solubility parameter of the addition polymerization-based resin.

Toner for electrophotography, developer for electrophotography, image forming apparatus, and process cartridge

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

A toner includes a binder resin; and a plate-shaped pigment having a silica coated layer on the surface, an average-particle diameter of from 10 &#x3bc;m to 25 &#x3bc;m, and an aspect ratio of from 20 to 125.

Toner, toner housing unit, image forming apparatus, and image forming method

A resin composition for a toner including a polyester resin and a colorant, wherein the polyester resin has A(10)-A(180) of 70 or greater, where A(10) (%) is a transmittance of light having a wavelength of 500 nm through a mixture of 20 parts by mass of the polyester resin added to 80 parts by mass of ethyl acetate and stirred at 25&#xb0; C. for 10 minutes, and A(180) (%) is the transmittance after the mixture is left to stand for 3 hours.

Resin composition for toner, toner, developer and image forming apparatus

A toner prepared by a method comprising granulating while polymerizing a ring-opening polymerizable monomer with a catalyst under the presence of a surfactant and a colorant in a compressible fluid.

Provided is a toner including a crystalline resin and a non-crystalline resin. In a reflected electron image of a cross-section of the toner stained by ruthenium tetroxide captured by a scanning electron microscope, the ratio of regions stained by ruthenium tetroxide is from 50 area % to 80 area %. In a reflected electron image of the surface of the toner stained by ruthenium tetroxide captured by a scanning electron microscope, the ratio of regions stained by ruthenium tetroxide is from 10 area % to 40 area %.

Toner, developer, image forming apparatus, and process cartridge

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Shizuoka, Japan

Yoshitaka Yamauchi