Canon Kabushiki Kaisha

Sara Yoshida

Kentaro Yamawaki

Tsuneyoshi Tominaga

Shiro Kuroki

Toshihiko Katakura

Kenta Kamikura

Tsutomu Shimano

Akane Masumoto

Shinsuke Mochizuki

Kunihiko Nakamura

Tomonori Matsunaga

Taiji Katsura

Yusuke Kosaki

Hidekazu Fumita

Katsuyuki Nonaka

Koji Abe

Yoshihiro Nakagawa

Naoya Isono

Arihiro Yamamoto

Yasutaka Yagi

Toshiya Kaino

Reo Tagawa

Maho Tanaka

Harumi Takada

Syoji Inoue

Takayoshi Ootsuka

Itaru Kondo

A toner including: a toner particle containing a binder resin and a colorant; and a fine particle on a surface of the toner particle, wherein the fine particle is a solid and substantially hemispherical shape, and has a substantially flat surface and a curved surface, and wherein a number-average value of a longest diameter 'w' of the substantially flat surface is 10 to 400 nm. An external additive for a toner that is a solid and substantially hemispherical shape, and has a substantially flat surface and a curved surface, wherein a number-average value of a longest diameter “w” of the substantially flat surface is 10 to 400 nm. A fine particle that is a solid and substantially hemispherical shape, and has a substantially flat surface and a curved surface, wherein a number-average value of a longest diameter “w” of the substantially flat surface is 10 to 400 nm.

Toner, external additive for toner, and fine particle

The present invention provides a toner that can maintain excellent transferability even when a transfer bias is low. The toner includes a toner particle that includes a toner base particle and a plurality of convex portions X existing on a surface of the toner base particle, wherein the convex portion X contains an organic silicon polymer; when a cross-section of the toner is observed with a scanning transmission electron microscope (STEM), and the convex portions X comprise a plurality of convex portions Y each having a convex height H of 40 nm or higher, a number ratio P (H/w) of the a number of the convex portions Yin which a ratio (H/w) of the convex height H to the convex width w is 0.33 or larger and 0.80 or smaller is 70% by number or more with respect to a total number of the convex portions Y.

Toner

A toner comprising a toner particle and an external additive, wherein the external additive comprises a composite particle comprising an organosilicon polymer fine particle covering a surface of an alumina particle, a coverage ratio of the surface of the alumina particle with the organosilicon polymer fine particle is 1 to 50 area %, and given A (nm) as a number-average particle diameter of primary particles of the organosilicon polymer fine particle and B (nm) as a number-average particle diameter of primary particles of the alumina particle, following formulae (I) and (II) are satisfied:&#x2264;90&#x2003;&#x2003;(I)100&#x2264;&#x2264;1000&#x2003;&#x2003;(II).

The electrophotographic apparatus and process cartridge comprising an electrophotographic photosensitive member, a cleaning blade, and developing unit containing a toner, wherein the cleaning blade comprising a support member and an elastic member whose portion is abutting a surface of the electrophotographic photosensitive member; the elastic member has an elastic modulus of 15 to 470 MPa with coefficient of variation for the elastic modulus being not more than 7.0%, and the absolute value of a difference between Martens hardness values is not more than 0.30 N/mmas measured under prescribed conditions; the toner contains a toner particle and an external additive whose a number-average primary particle diameter is from 5 to 25 nm, when X1 is a coverage ratio of the toner particle by the external additive and X2 is a theoretical coverage ratio, X1 is 50 to 85 area %, and X1/X2&#x2265;&#x2212;0.0042&#xd7;X1+0.60 is satisfied.

Electrophotographic apparatus and process cartridge

A toner comprising a binder resin and a colorant, wherein the toner has a Martens hardness, as measured at a maximum load condition of 2.0&#xd7;10N, of from 200 MPa to 1,100 MPa.

Provided is a toner containing a colorant and a binder resin, wherein, in a wettability test of the toner with respect to a methanol/water mixed solvent, the methanol concentration when the transmittance of light at a wavelength of 780 nm is 50% is at least 5.0 volume % and not more than 30.0 volume %, and the interparticle force measured by rupturing a consolidation of the toner formed by compression of the toner with a load of 78.5 N is at least 1.0 nN and not more than 25.0 nN.

A toner comprising a toner particle that contains a binder resin and a release agent, wherein the toner particle has a surface layer that contains an organosilicon polymer and the luminance histogram of a backscattered electron image of the toner particle has two peak values Pand Pand a minimum value V between Pand P, Poriginates from the organosilicon polymer, and the luminance giving Pand Pare in specific ranges, percentages for Pand Pare each at least 0.50%, and using the luminance Bl at V as a reference point, specific relationships are satisfied by A, AV, and A, where Ais the total number of pixels at luminance from 0 to (Bl&#x2212;30 ), AV is the total number of pixels at luminance from (Bl&#x2212;29 ) to (Bl+29 ), and Ais the total number of pixels at luminance from (Bl+30 ) to 255.

An image forming apparatus includes an image bearing member, a developing device, and an intermediate transfer member. The developing device includes a toner container containing a toner. The intermediate transfer member is charged to 3.0 nC/g or less in terms of absolute value at the surface thereof. The toner particles include a surface layer, and the brightness histogram of the toner particles has two local maximums Pand Pand a local minimum V between Pand P. Pis derived from an organosilicon polymer. Plies in a brightness range of 20 to 70, and Plies in a brightness range of 130 to 230. The number of pixels of Pand the number of pixels of Pare each 0.50% or more relative to the total number of pixels. The total numbers of pixels A, AV, and Aeach in a specific brightness range satisfy specific relationships.

Image forming apparatus and image forming method

Provided is a toner that is excellent in development durability and has excellent solid followability even when the amount of the toner in a toner cartridge is small. The toner includes toner particles each having a surface layer containing an organosilicon polymer, in which: the organosilicon polymer includes a siloxane-based polymer having partial structures represented by the following formulae (1) and (2); and in a chart obtained bySi-NMR measurement of a tetrahydrofuran-insoluble matter of the toner particles, an area RT3 of a peak assigned to the partial structure represented by the following formula (1) and an area RfT3 of a peak assigned to the partial structure represented by the following formula (2) satisfy the following formula (3).0.300&#x3e;(3/3)&#x2267;0.010&#x2003;&#x2003;(3)R&#x2014;SiO&#x2003;&#x2003;(1)Rf&#x2014;SiO&#x2003;&#x2003;(2)

A toner contains a styrene acrylic resin, a block polymer, and an organosilicon polymer, in which the organosilicon polymer has a specific partial structure, the block polymer has a polyester segment and a vinyl polymer segment, the melting point is 55&#xb0; C. or more and 90&#xb0; C. or less, the mass ratio of the polyester segment to the vinyl polymer segment is 40/60 to 80/20, and the polyester segment has a specific unit.

Toner and method for producing toner

Provided is a toner, including toner particle having surface layer, in which: the surface layer includes organosilicon polymer which has a partial structure represented by formula (1); inSi-NMR measurement of tetrahydrofuran-insoluble matter of toner particle, a ratio of a peak area for the partial structure represented by formula (1) to a total peak area for the organosilicon polymer is 5.0% or more; in X-ray photoelectron spectroscopic analysis of a surface of toner particle, a ratio of a density of a silicon atom dSi in the surface of toner particle is 1.0 to 28.6 atom %; and in a roughness curve of toner particle measured by using a scanning probe microscope: an arithmetic average roughness Ra is 10 to 300 nm; &#x3c3;Ra/Ra is 0.60 or less; an average length RSm of a roughness curve element is 20 to 500 nm; and &#x3c3;RSm/RSm is 0.60 or less.

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Mishima, Japan

Sara Yoshida