Canon Kabushiki Kaisha

Noriyoshi Umeda

Takeshi Yamamoto

Naoki Okamoto

Tetsuya Ida

Shohei Kototani

Tomonori Matsunaga

Yoshinobu Baba

Takayuki Itakura

Koh Ishigami

Tsuneyoshi Tominaga

Shohei Tsuda

Yojiro Hotta

Kazuo Terauchi

Kazuhiro Yamauchi

Masamichi Sato

Kunihiko Nakamura

Yuhei Terui

Kosuke Fukudome

Shuhei Moribe

Hiroaki Kawakami

Manami Haraguchi

Kenta Kubo

Hidekazu Fumita

Yoshiaki Shiotari

Satoshi Mita

Satoshi Otsuji

Masaya Kawada

Masahiro Kurachi

Shinsuke Mochizuki

Hirohide Tanikawa

Toshiaki Takeuchi

Nozomu Komatsu

Yoshihiro Mitsui

Masatake Tanaka

Kentaro Yamawaki

Yuichiro Hirata

Taiji Katsura

Masayuki Hama

Yasutaka Yagi

Go Shindo

Hideo Kihara

Takeshi Kaburagi

Motonari Ito

Yasukazu Ikami

Takeshi Naka

Fumihiro Arahira

Noboru Miyagawa

Kosuke Ikada

Naotaka Ikeda

Kazunori Hashimoto

Hirofumi Kyuushima

Katsuhiro Kojima

Shohei Shibahara

Takeshi Ootsu

Akinobu Saito

Yoshiaki Wada

An electrophotographic apparatus including an electrophotographic photosensitive member, a charging unit, and a developing unit, wherein the charging unit includes a conductive member disposed to be contactable with the electrophotographic photosensitive member, a conductive layer of the conductive member has a matrix-domain structure, at least some of the domains are exposed at the outer surface of the conductive member, the volume resistivity RI of the matrix is greater than 1.00&#xd7;10&#x3a9;&#xb7;cm and not greater than 1.00&#xd7;10&#x3a9;&#xb7;cm, the matrix volume resistivity R1 is at least 1.0&#xd7;10-times the domain volume resistivity R2, and the developing unit includes a toner, the toner includes a binder resin-containing toner particle and an external additive, and the external additive contains fine particles of a hydrotalcite compound.

Electrophotographic apparatus, process cartridge, and cartridge set

An electrophotographic apparatus comprising an electrophotographic photosensitive member, a charging unit, and a developing unit, wherein the charging unit has a conductive member contactable with the electrophotographic photosensitive member, and a conductive layer of the conductive member has a matrix-domain structure; at least some of the domains are exposed at the outer surface; a volume resistivity R1 of the matrix and a volume resistivity R2 of the domains satisfy specific relationship; Martens hardness G1 of the matrix and Martens hardness G2 of the domains satisfy relationship G1&#x3c;G2; the surface roughness Ra of the conductive member is not more than 2.00 &#x3bc;m; the toner has an external additive having a shape factor SF-1 of not more than 115; and A&#x3c;Dms is satisfied where A is the number-average diameter of the external additive and Dms is a distance between adjacent walls between the domains.

A toner comprising: a toner particle including a binder resin; and an external additive, wherein the external additive includes an external additive A which is silica fine particles and an external additive B which is a fatty acid metal salt, the external additive A has a specific particle diameter, a coverage ratio of a surface of the toner particle with the external additive A is from 60% to 80%, and where an average theoretical surface area obtained from a number average particle diameter, a particle size distribution and a true density of the toner particle is denoted by C (m/g), an amount of the external additive B is denoted by D (parts by mass) and a coverage ratio of the surface of the toner particle with the external additive B is denoted by E (%), following formulas are satisfied:0.05&#x2264;&#x2264;2.00/()&#x2264;50.0.

Toner

A toner comprising: a toner particle that contains a release agent-containing toner base particle, and an organosilicon polymer on a toner base particle surface, and an external additive A, the organosilicon polymer has a T3 unit structure; the organosilicon polymer forms protruded portions on the toner base particle surface; the number-average value of the protrusion height H is from 30 nm to 300 nm; the ratio of the number-average primary particle diameter R of the external additive A to the number-average value of the protrusion height H is from 1.00 to 4.00; the number-average primary particle diameter R of the external additive A is from 30 nm to 1,200 nm; and, in an image obtained by observing the toner surface with SEM, the area percentage for the bright region area in the image with reference to the total area of the image is from 30.0% to 75.0%.

An electrophotographic apparatus comprising an electrophotographic photosensitive member, a charging device, and a developing device, wherein the charging device comprises a conductive member arranged to be capable of contacting the electrophotographic photosensitive member, a conductive layer on the conductive member outer surface comprises a matrix and a plurality of domains dispersed in the matrix, at least some of the domains are exposed at the conductive member outer surface, the matrix has a volume resistivity of larger than 1.00&#xd7;10&#x3a9;&#xb7;cm and is 1.0&#xd7;10times or more one of the domains, the developing device comprises the toner comprising a toner particle, fine particles A and B, the fine particle A has a volume resistivity of 1.0&#xd7;10to 1.0&#xd7;10&#x3a9;&#xb7;cm, and the fine particle B is silica fine particle and having a volume resistivity of 1.0&#xd7;10to 1.0&#xd7;10&#x3a9;&#xb7;cm.

Electrophotographic apparatus, process cartridge and cartridge set

A process cartridge includes a seal member contacting an image bearing member upstream in the rotation direction of the image bearing member from a cleaning member and allowing the developer to move from upstream in the rotation direction from the contact part between the seal member and the image bearing to downstream from the contact part while regulating movement from downstream to upstream from the contact part. The developer has surface protrusions containing an organic silicon polymer, wherein either (i) the work function of the seal member is greater than the work function of the developer when the developer has a negative charging polarity and is smaller than the work function of the developer when the developer has a positive charging polarity, or (ii) the absolute value of the difference between the work function of the seal member and the work function of the developer is within a predetermined range.

Process cartridge, image forming apparatus and cleaning apparatus

Provided is a toner including a toner particle containing a binder resin, and an external additive, wherein the external additive contains an external additive A and an external additive B, the external additive A is an organosilicon polymer fine particle, the number-average particle diameter of primary particles of the organosilicon polymer fine particle is from 30 to 300 nm, the external additive B is a silica fine particle, the number-average particle diameter of primary particles of the silica fine particle is from 100 to 300 nm, the fixing rate of the external additive A to the toner particle according to a water washing method is less than 30%, and the fixing rate of the external additive B to the toner particle according to the washing method is at least 30%.

A toner has a toner particle that has a binder resin and a release agent, wherein when the temperature when G'=1.0&#xd7;10Pa in a dynamic viscoelastic measurement on the toner is denoted by Ta, and the glass transition temperature in a differential scanning calorimetric measurement on the toner is denoted by Tg, the Ta and the Tg satisfy the following formulas:40&#xb0; C.&#x2264;Tg&#x2264;70&#xb0; C.,60&#xb0; C.&#x2264;Ta&#x2264;90&#xb0; C., and0&#xb0; C.&#x2264;&#x2264;35&#xb0; C.; and

A image-forming apparatus includes a plurality of process cartridges each having a toner and an image bearing member, and has an intermediate transfer member, wherein the toner comprises a toner particle that contains a toner base particle and a prescribed organosilicon polymer on the surface of the toner base particle, and the organosilicon polymer forms protruded portions on the surface of the toner base particle, for the protrusions having a protrusion height H from 40 nm to 300 nm, the numerical proportion P(D/w) of protruded portions having a ratio of the protrusion diameter D to the protrusion width w in a prescribed range is at least 70 number %, and one of the plurality of process cartridges has a carbon black-containing black toner, and the weight-average particle diameter of this black toner is smaller than that of the toner present in the other process cartridges.

Image-forming apparatus

A toner comprising a toner particle that contains a toner base particle and an organosilicon polymer on a surface of the toner base particle, wherein the organosilicon polymer forms protruded portions with a prescribed structure on the surface of the toner base particle, and in the toner cross section, when the protrusion width w is the length of the segment where a protruded portion and the toner base particle form a continuous interface, the protrusion diameter D is the maximum length of a protruded portion, and the protrusion height H is the length from the peak of the protruded portion to the line along the circumference of the toner base particle surface, the numerical proportion of these protruded portions having a ratio D/w of the protrusion diameter D to the protrusion width w from 0.33 to 0.80, is a least 70 number %.

Toner comprising a surface layer of an organosilicon polymer protrusion

A toner comprising a toner particle having a binder resin, a wax and a colorant, and metal titanate fine particles having a perovskite crystal structure, wherein in cross section observation of the toner using a transmission electron microscope, when a proportion of an area occupied by the wax in a surface layer region from the surface of the toner particle to a depth of 1.0 &#x3bc;m is denoted by As, the As is from 5.0% to 30.0%, and a number average particle diameter of primary particles of the metal titanate fine particles is from 10 nm to 80 nm.

The toner has a toner particle that contains a binder resin and a wax, wherein the wax is present in domain form in the interior of the toner particle; the proportion of toner particles for which the position of the wax domains are controlled, is in a prescribed range; using d for a major axis length of the domain having the largest major axis length and using D for a number-average particle diameter of the toner, the d and D satisfy a prescribed relationship; and the ratio between the major axis length and the minor axis length of the domain having the largest major axis length is in a prescribed range.

A toner contains toner particles. The toner particles are made of a resin containing an amorphous polyester resin, a releasing agent, an additive and a coloring agent. The additive has a polyester portion and a crystalline acrylic portion that are chemically bound to each other.

Toner and two-component developer

Provided is a toner has toner particle containing a crystalline polyester resin A, an amorphous resin B and a colorant, wherein (1) the crystalline polyester resin A is a resin that has a crystal nucleating agent segment (D) on the end of a polyester molecular chain (C), (2) the amorphous resin (B) is a hybrid resin in which a polyester unit (E) and a vinyl polymer unit (F) are chemically bonded, and (3) the SP value of the polyester molecular chain (C) (Sc), the SP value of the crystal nucleating agent segment (D) (Sd), the SP value of the polyester unit (E) (Se) and the SP value of the vinyl polymer unit (F) (Sf) satisfy specific relationships.

Provided is a toner having excellent long-term storage stability and exhibiting both low-temperature fixability and uniform gloss in high-speed printing. A toner has a toner particle that contains a crystalline polyester resin A, an amorphous polyester resin B and a colorant, wherein the crystalline polyester resin A has a polyester molecular chain having a nucleating agent segment at the terminal end thereof, and an SP value Sa ((cal/cm)) of the crystalline polyester resin A ranges from 9.00 to 11.50, and the amorphous polyester resin B has a specific functional group.

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Suntou-gun, Japan

Noriyoshi Umeda