Canon Kabushiki Kaisha

Satoshi Otsuji

Masamichi Sato

Hiroyuki Watanabe

Kentaro Yamawaki

Noriyoshi Umeda

Tomonori Matsunaga

Hidekazu Fumita

Atsushi Okuda

Tsutomu Nishida

Yuka Ishiduka

Nobuhiro Nakamura

Masatake Tanaka

Daisuke Miura

Tsuneyoshi Tominaga

Shohei Tsuda

Hideharu Shimozawa

Shohei Kototani

Shinsuke Mochizuki

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

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 toner having a toner particle including a binder resin and a wax, wherein the wax includes a specific diester compound; a proportion As of an area occupied by the wax in a region from a surface of the toner particle to 0.5 &#x3bc;m is 15.0% or less; wax domains are observed in the cross section of the toner particle, and an average number of the domains per cross section of one toner particle is from 10 to 2000; when a mass concentration of a polyvalent metal element in the toner particle determined by fluorescent X-ray analysis is denoted by Mi (ppm), Mi is from 3.5 ppm to 1100 ppm; and when a mass concentration of a polyvalent metal element in the toner particle determined by X-ray photoelectron spectroscopy is denoted by Ms (ppm),Mi&#x3e;Ms.

Provided is a process cartridge including: an electrophotographic photoreceptor; a charging unit configured to charge the electrophotographic photoreceptor through abutment against the electrophotographic photoreceptor; a developing unit configured to develop an electrostatic latent image formed on the electrophotographic photoreceptor with a toner to form a toner image; and a cleaning unit configured to remove the toner on the electrophotographic photoreceptor by bringing a blade into abutment against the electrophotographic photoreceptor, wherein the toner includes a toner base containing a coloring agent and a binder resin, and has a surface layer containing an organosilicon polymer having a specific sticking ratio to a toner base, and wherein the electrophotographic photoreceptor includes a supporting member and a surface layer, and the surface layer has a specific universal hardness value and a specific elastic deformation ratio (We).

Process cartridge and electrophotographic apparatus

Growing community of inventors

Yokohama, Japan

Satoshi Otsuji