Canon Kabushiki Kaisha

Yusuke Kosaki

Kenji Aoki

Atsushi Tani

Shuntaro Watanabe

Tetsuya Kinumatsu

Takashige Kasuya

Noritaka Toyoizumi

Takaaki Kaya

Kazumichi Nakahama

Toshifumi Mori

Shinnosuke Koji

Kentaro Yamawaki

Taiji Katsura

Hidekazu Fumita

Sara Yoshida

Sakae Suda

Kunihiko Nakamura

Kenta Kamikura

Maho Tanaka

Keisuke Tanaka

Masami Fujimoto

Koji Nishikawa

Yojiro Hotta

Kazuyuki Sato

Yu Yoshida

Kazuo Terauchi

Takaaki Furui

Ryo Nagata

Yoshihiro Nakagawa

Arihiro Yamamoto

Toshiya Kaino

Syoji Inoue

Shohei Fukuya

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 having a toner particle having a plurality of fine particles on the surface of a toner base particle, the toner base particle contains a binder resin, wherein a fine particle layer A constituted of a plurality of the fine particles is observed in an EDX mapping image of the constituent elements in a cross section of the toner particle as provided by EDX of the toner particle cross section observed using TEM; a fine particle B, containing a metal compound containing at least one metal element M selected from all the metal elements belonging to Groups 3 to 13, is observed in the fine particle layer A; and the number-average particle diameter D of the fine particle B, the average value H of the thickness of the fine particle layer A, and the standard deviation S on the thickness of the fine particle layer A satisfy prescribed relationships.

A toner comprising a toner particle comprising a binder resin, wherein a layer comprising an organosilicon condensate is present on the surface of the toner particle; the layer comprising the organosilicon condensate further comprises a reaction product of a compound comprising at least one metal element selected from all the metal elements belonging to Groups 3 to 13, and a polyhydric acid; in a backscattered electron image of the toner captured at a magnification of 50,000 times by using a scanning electron microscope, an average value of an area of the reaction product is from 10 nmto 5000 nm, and a coefficient of variation of the area of the reaction product is not more than 10.0.

A toner comprising a toner particle that contains a binder resin, wherein the surface of the toner particle has a reaction product of a polyhydric acid and a compound that contains a group 4 element.

A method of producing a toner including the steps of: mixing resin fine particles, an organic solvent, and a resin R with a dispersion medium containing carbon dioxide, to prepare a dispersion of resin R-containing droplets; and removing the organic solvent by flowing carbon dioxide, wherein the resin fine particles contain one or more resins that have a partial structure A, B, and C, and are soluble in chloroform; the SP value of the partial structure A, the resin R, and the partial structure B satisfy particular relationships; a resin A constituted of the partial structure A and a resin B constituted of the partial structure B are soluble in the organic solvent; and a resin C constituted of the partial structure C is insoluble in the organic solvent.

Resin fine particles, method of producing resin fine particles, method of producing resin particles, and method of producing toner

A toner including a toner particle and an external additive, wherein the external additive contains an inorganic fine particle A and a silica fine particle; in a surface of the toner observed using a scanning electron microscope, a number-average particle diameter of primary particle of the silica fine particle is from 5 nm to 50 nm, a number-average particle diameter of primary particle of the inorganic fine particle A is at least 10 nm and less than 60 nm, a coverage ratio X1 of the toner surface covered by the silica fine particle is from 60 area % to 95 area %, the inorganic fine particle A is a fine particle of a titanate having a Group 2 element, and a coverage ratio X2 of the toner surface covered by the inorganic fine particle A is from 5 area % to 40 area %.

Provided is toner that contains a toner particle, and an external additive containing a strontium titanate particle, wherein the toner has an average circularity of at least 0.935 and not more than 0.995, the strontium titanate particle has a number-average primary particle diameter of at least 10 nm and not more than 60 nm, the strontium titanate particle has a peak in the range of 39.700&#xb0;&#xb1;0.150&#xb0; and a peak in the range of 46.200&#xb0;&#xb1;0.150&#xb0; in a CuK&#x3b1; x-ray diffraction spectrum obtained in the 2&#x3b8; range of at least 10&#xb0; and not more than 90&#xb0; where &#x3b8; is the Bragg angle, and the ratio of the area Sb of the peak at 46.200&#xb0;&#xb1;0.150&#xb0; to the area Sa of the peak at 39.700&#xb0;&#xb1;0.150&#xb0; is at least 1.80 and not more than 2.30.

A method for producing a toner particle include: (a) mixing a binder resin A, resin fine particles containing a resin B, a resin C, an organic solvent, and carbon dioxide, thereby forming a droplet of a resin solution containing the binder resin A, covered with the resin fine particles; (b) applying a pressure by introducing carbon dioxide, thereby precipitating the resin C at the surface of the droplet; and (c) passing carbon dioxide so as to remove the organic solvent from the droplet with the carbon dioxide. The resin C has an organic polysiloxane structure and a weight average molecular weight of 50,000 to 500,000. The ratio of the weight average molecular weight to the number average molecular weight of the resin C is not more than 5.0. The proportion of the resin C to the rein fine particles is 5.0% by mass to 50.0% by mass.

Methods for producing toner particle and producing resin particle

A toner includes toner particles which contain a binder resin, a colorant, a wax, and a resin A having an organic polysiloxane structure; the amount of Si atoms of the toner particles is 4.5 to 10.0; in an analysis of a cross-section of each toner particle, in a surface layer region R from the periphery of the cross-section of the toner particle to the inside at a distance of 10.0% of the particle diameter in the cross-section of the toner particle, the content of Si atoms derived from the organic polysiloxane structure is 90.0% or more with respect to the total amount of Si atoms contained in the toner particle; and in a line analysis along a straight line between the periphery of the surface layer region R and a gravity center of the cross-section, an intensity count of Si atoms in the toner particle satisfies formula Si&#x3e;Si&#x3e;Si&#x3e;Si&#x2265;0.

Toner and method for manufacturing the same

A method of producing a toner containing a toner particle, including the steps of: a) preparing a resin solution by mixing a resin A and an organic solvent, b) mixing the resin solution, a resin fine particle containing a resin B, and a dispersion medium to form a droplet of the resin solution whose surface has been covered with the resin fine particle, and c) removing the organic solvent in the droplet, in which the resin B is a polymer of a monomer composition containing a monomer X having polymerizable unsaturated groups at the both ends; the monomer X has a peak molecular weight of 5,000 to 50,000; the content of the monomer X is 0.10% to 3.00% by mol; and the following formula (1) is satisfied,|SP&#x2212;SP|&#x2266;2.0&#x2003;&#x2003;(1)where SPand SPrepresent solubility parameters of the resin A and the monomer X, respectively.

Method of producing toner and method of producing resin particle

Provided is a toner, comprising a toner particle having a core-shell structure composed of a core particle and a shell phase on a surface of the core particle, the core particle containing a resin X and a colorant, the shell phase being derived from a resin fine particle containing a resin Y, in which a relationship among a SP value of the resin X, a SP value of the resin Y, and a SP value of an organic solvent falls within a specific range, and a relationship between a number-average particle diameter of the resin fine particle when the resin fine particle is dispersed in water and a number-average particle diameter of the resin fine particle when the resin fine particle is dispersed in the organic solvent falls within a specific range.

Resin particle and method of producing the resin particle, and toner and method of producing the toner

Provided is a toner including toner particle, the toner particle having a core-shell structure having: a core containing a core resin, a colorant, and a wax; and a shell layer containing a resin 'A' on a surface of the core, in which: the resin 'A' contains a segment having an organopolysiloxane structure; the toner particle has an amount of Si derived from the organopolysiloxane structure of 6.0 or more and 10.0 or less, the amount of Si being measured by X-ray photoelectron spectroscopy; the resin &#x201c;A&#x201d; is a polymer of a monomer composition containing a monomer &#x201c;a&#x201d; having two or more polymerizable unsaturated groups in one molecule thereof; and the monomer &#x201c;a&#x201d; satisfies the following formula (1).(&#x2212;1.0)&#xd7;&#x2267;3.0&#xd7;10&#x2003;&#x2003;(1)

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Susono, Japan

Yusuke Kosaki