Ricoh Company, Ltd.

Minolta Company, Ltd.

Konica Minolta Business Technologies, Inc.

Yoshihiro Mikuriya

Masayuki Hagi

Kazuoki Fuwa

Takuya Kadota

Hideaki Yasunaga

Yoshimichi Ishikawa

Masahide Inoue

Yoshitaka Sekiguchi

Atsushi Yamamoto

Tsuyoshi Nozaki

Tomohiro Fukao

Hiroaki Katoh

Tomoharu Miki

Minoru Nakamura

Katsunori Kurose

Hiroaki Kato

Junichi Tamaoki

Megumi Aoki

Takeshi Arai

Masahiro Anno

Tetsuo Sano

Kenichi Kido

Yoshikazu Nishihara

Chiyoshi Nozaki

Satoshi Ogawa

Ichiro Demizu

Naoki Nakatake

Hiroyuki Fukuda

Takayuki Nakamura

Hiroshi Fukao

Hiroyuki Murakami

Yoshiyuki Shimizu

Yuta Takeuchi

Fumiko Nakazawa

Ryota Inoue

Shun Saito

Yoshie Iwakura

Chikara Tsutsui

Manabu Hamada

Takeshi Yamashita

Yasuhide Matsuno

Tetsushi Sakuma

Hidekazu Shono

Masahiro Seki

Takeshi Ishida

Chieko Yamazaki

Mikihiko Sukeno

Masayasu Hagi

Fumiko Hirano

A toner is provided. The toner includes a crystalline resin and a non-crystalline resin, and has a thermal property such that when the toner is heated after being firstly heated to 60&#xb0; C. followed by cooling in differential scanning calorimetry (DSC), the toner has a clear peak specific to melting of the crystalline resin at a temperature T1, and when the toner is heated after being firstly heated to 80&#xb0; C. followed by cooling in the differential scanning calorimetry (DSC), the toner does not have a clear peak specific to melting of the crystalline resin at a temperature not higher than the temperature T1.

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

A toner is prepared by wet granulation methods, including a monoester wax having carbon atoms of from 36 to 46 on average as a release agent. The toner has a DSC endothermic energy amount (&#x394;H1) originating from the wax of from 10 to 12 mJ/mg and a DSC endothermic energy amount (&#x394;H2) originating from the wax of from 0.6 to 0.9 times as much as &#x394;H1 after a part of the wax is separated by hexane extraction from the toner. The hexane extraction includes mixing 1 g of the toner in 7 ml of n-hexane to prepare a mixture; stirring the mixture at 120 rpm for 1 min by a pot mill to prepare a dispersion; and subjecting the dispersion to suction filtration.

Toner

A toner including: toner particles each including a toner base particle and an external additive attached thereon, where the toner base particle includes a binder resin and a colorant, wherein the toner base particles each have protrusions on a surface thereof, an average of lengths of long sides of the protrusions is 0.10 &#x3bc;m or more but less than 0.50 &#x3bc;m, a standard deviation of the lengths of the long sides of the protrusions is 0.2 or less, a coverage rate of the protrusions on the surface of the toner base particle is 10% to 90%, and the external additive includes fine inorganic particles whose surfaces have been treated with an amino group-containing silane coupling agent.

Toner and image forming apparatus

An image forming apparatus is provided which includes an image bearer, a charger, an irradiator, a developing device to develop an electrostatic latent image on the image bearer with a toner to form a toner image, a transfer device to transfer the toner image onto a transfer medium, and a cleaner to remove toner particles remaining on the image bearer without being transferred. The toner includes a mother particle including a binder resin and a colorant and one or more external additives. At least one of the external additives includes primary particles having a number average particle diameter in the range of 0.05 to 0.30 &#x3bc;m. The cleaner includes an elastic body blade having a contact part with the image bearer. The contact part has a surface elastic modulus in the range of 15 to 25 N/mmand a surface friction coefficient in the range of 0.5 to 0.7.

Image forming apparatus and process cartridge

A toner including: a core particle containing at least a binder resin, a colorant and a releasing agent; and a shell on a surface of the core particle, wherein the toner gives a supernatant having a transmittance of 50% to 95% with respect to light having a wavelength of 800 nm, where the supernatant is formed after 3 g of the toner is added to 40 g of ion-exchange water containing 0.5% by mass of sodium dodecyl sulfate, followed by stirring for 90 min and by irradiating with ultrasonic waves of 20 kHz and 80 W for 5 min, and a liquid containing the toner dispersed therein is centrifugated at 3,000 rpm for 5 min.

Latent electrostatic image developing toner

An electrostatic image developing toner including: toner base particles each including a binder resin and a colorant; and an external additive, wherein the toner base particles each have protrusions on a surface thereof, an average of lengths of long sides of the protrusions is 0.1 &#x3bc;m or more but less than 0.5 &#x3bc;m, a standard deviation of the lengths of the long sides of the protrusions is 0.2 or less, a coverage rate of the protrusions on the surface of each toner base particle is 10% to 90%, and the external additive includes an external additive (A) which is fine inorganic particles each containing silicone oil.

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

Image forming apparatus, image forming method and process cartridge

A toner, including: a binder resin; releasing agent-encapsulating capsules; and a colorant, wherein the releasing agent-encapsulating capsules each include: a capsule formed of a resin (I) which is different from the binder resin; and a releasing agent (RA) which is encapsulated in the capsule, and the releasing agent-encapsulating capsules exist in the binder resin, and wherein 50% to 100% of the releasing agent-encapsulating capsules exist in a region from a surface of the toner to a depth of 0.10 times a volume-average particle diameter of the toner.

Toner, developer, process cartridge, and image forming apparatus

To provide a toner comprising: a binder resin, a colorant, and a releasing agent, wherein the toner has a core shell structure, and wherein the core contains at least one resin selected from the group consisting of a hybrid resin and a polyester resin, where the hybrid resin is a resin in which a polyester resin and a vinyl resin are chemically bonded to each other, and the shell contains a resin prepared by polymerizing at least a styrene monomer and an ester monomer represented by the following General Formula (1): where, 'n' is 2 or 3, 'X' is any of 0 to 9, Ris a hydrogen atom, or an alkyl group, and Ris a hydrogen atom, an alkyl group, or a phenyl group.

Toner, image forming apparatus, and process cartridge

A method for producing colored resin particles including: dissolving or dispersing at least binder resin and colorant in organic solvent to prepare oil phase; dissolving resin A and basic compound in aqueous medium to prepare aqueous phase, the resin A having solubility &#x3c;2.0 g/100 g water having temperature 25&#xb0; C. and pH 3.0 and solubility &#x2267;2.0 g/100 g water having temperature 25&#xb0; C. and pH 10.0; dispersing the oil phase in the aqueous phase to prepare core particle dispersion liquid; dispersing resin particles in aqueous medium to prepare resin particle dispersion liquid, and adding the resin particle dispersion liquid to the core particle dispersion liquid so that the resin particles are attached onto the core particles, to prepare dispersion liquid containing particles each having the core particle and the resin particles attached thereonto; removing the organic solvent from the dispersion liquid; washing the particles; and drying the particles.

Method for producing colored resin particles, colored resin particles, developer, image forming apparatus, image forming method, and process cartridge

A toner including: a core particle; and fine resin particles, the core particle containing at least a binder resin, a releasing agent and a colorant, wherein the toner is in shape of particles, and each toner particle has a sea-island structure having the core particle and island portions, which are convex portions formed from the fine resin particles on surface of the core particle, wherein the binder resin contains first and second resins, and the fine resin particles are made of third resin, wherein the first resin is crystalline resin, and the second and third resins are non-crystalline resin, wherein the second resin has glass transition temperature (Tg2) and the crystalline resin has melting point (Tc1) where Tg2 is higher than Tc1, and wherein the third resin has glass transition temperature (Tg3) and the toner has glass transition temperature (Tgt) wherein Tg3 is higher than Tgt.

Toner, developer and method for producing toner

An electrostatic image developing toner including: toner particles each containing binder resin and colorant; and an external additive supported on the toner particles, wherein the toner particles each have protrusions on surface thereof, average of lengths of long sides of the protrusions is 0.10 &#x3bc;m or more but less than 0.50 &#x3bc;m, standard deviation of the lengths of the long sides of the protrusions is 0.20 or less, coverage rate of the protrusions on the surface of each toner particle is 30% to 90%, the external additive includes at least two different particles including external additive (A) and one or more external additives (B), external additive (A) has longest average primary particle diameter among the external additives and charged to have the opposite polarity to the toner particles, and at least one of the external additives (B) is charged to have the same polarity as the toner particles.

Electrostatic image developing toner, developer, and image forming apparatus

An electrostatic image developing toner including: toner particles; wherein the toner particles each contain: a core particle including a first resin and a colorant; and fine resin particles each formed of a second resin and existing in a surface of the core particle, wherein part of each fine resin particle is embedded in the core particle to form an embedded region, and the remaining part of the fine resin particle is exposed on the surface of the core particle to form an exposed region, and wherein each toner particle satisfies an expression of R&#x3e;R' where, in a cross-section of the toner particle, R&#x2032; denotes an average diameter of openings of the first resin in which the second resin is embedded and Rdenotes an average diameter of the exposed regions.

Electrostatic image developing toner, toner container and process cartridge

An electrostatic image developing toner including toner core particles each containing at least a first resin and a colorant, and fine resin particles formed of a second resin, wherein part of each of the fine resin particles is embedded in each of the toner core particles, and the remaining part of the fine resin particle is exposed on a surface of the toner core particle to form a protrusion, and wherein when a rate of the part of the fine resin particle to the fine resin particle is indicated by an embedment rate, an average of the embedment rates in the fine resin particles is 40% to 80%.

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

A toner containing core particles each containing at least a resin A having a polyester skeleton and a colorant; and vinyl resin fine particles each of which encapsulates a resin B having at least a polyester skeleton and an endothermic peak measured by differential scanning calorimeter (DSC) at 40&#xb0; C. to 110&#xb0; C., wherein the vinyl resin fine particles are attached onto each of the core particles.

Toner and method for producing the same

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Nishinomiya, Japan

Yoshihiro Mikuriya