Patents by Inventor Yusuke Kosaki
Yusuke Kosaki has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
-
Patent number: 11960242Abstract: 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 Y2 in 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.Type: GrantFiled: October 12, 2021Date of Patent: April 16, 2024Assignee: CANON KABUSHIKI KAISHAInventors: Kentaro Yamawaki, Sara Yoshida, Yusuke Kosaki, Taiji Katsura, Hidekazu Fumita, Toshiya Kaino
-
Patent number: 11841681Abstract: 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: A?90??(I) 100?B?1000??(II).Type: GrantFiled: June 15, 2021Date of Patent: December 12, 2023Assignee: CANON KABUSHIKI KAISHAInventors: Taiji Katsura, Hidekazu Fumita, Kentaro Yamawaki, Sara Yoshida, Yusuke Kosaki, Takayoshi Ootsuka
-
Patent number: 11573519Abstract: 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/mm2 as 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??0.0042×X1+0.60 is satisfied.Type: GrantFiled: March 18, 2022Date of Patent: February 7, 2023Assignee: CANON KABUSHIKI KAISHAInventors: Hidekazu Fumita, Kentaro Yamawaki, Sara Yoshida, Yusuke Kosaki, Taiji Katsura, Syoji Inoue, Arihiro Yamamoto
-
Publication number: 20220334530Abstract: 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/mm2 as 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??0.0042×X1+0.60 is satisfied.Type: ApplicationFiled: March 18, 2022Publication date: October 20, 2022Inventors: Hidekazu Fumita, Kentaro Yamawaki, Sara Yoshida, Yusuke Kosaki, Taiji Katsura, Syoji Inoue, Arihiro Yamamoto
-
Publication number: 20220121132Abstract: 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.Type: ApplicationFiled: October 8, 2021Publication date: April 21, 2022Inventors: Sara Yoshida, Yusuke Kosaki, Taiji Katsura, Hidekazu Fumita, Kentaro Yamawaki, Itaru Kondo
-
Publication number: 20220121133Abstract: 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 Y2 in 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.Type: ApplicationFiled: October 12, 2021Publication date: April 21, 2022Inventors: Kentaro Yamawaki, Sara Yoshida, Yusuke Kosaki, Taiji Katsura, Hidekazu Fumita, Toshiya Kaino
-
Publication number: 20210397110Abstract: 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: A?90??(I) 100?B?1000??(II).Type: ApplicationFiled: June 15, 2021Publication date: December 23, 2021Inventors: Taiji Katsura, Hidekazu Fumita, Kentaro Yamawaki, Sara Yoshida, Yusuke Kosaki, Takayoshi Ootsuka
-
Patent number: 10635010Abstract: 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.Type: GrantFiled: January 22, 2019Date of Patent: April 28, 2020Assignee: CANON KABUSHIKI KAISHAInventors: Kenta Kamikura, Kunihiko Nakamura, Maho Tanaka, Yusuke Kosaki
-
Patent number: 10539893Abstract: 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 nm2 to 5000 nm2, and a coefficient of variation of the area of the reaction product is not more than 10.0.Type: GrantFiled: January 22, 2019Date of Patent: January 21, 2020Assignee: CANON KABUSHIKI KAISHAInventors: Maho Tanaka, Kunihiko Nakamura, Kenta Kamikura, Yusuke Kosaki
-
Patent number: 10539899Abstract: 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.Type: GrantFiled: January 17, 2019Date of Patent: January 21, 2020Assignee: CANON KABUSHIKI KAISHAInventors: Kunihiko Nakamura, Kenta Kamikura, Maho Tanaka, Yusuke Kosaki
-
Patent number: 10409180Abstract: 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.Type: GrantFiled: February 6, 2018Date of Patent: September 10, 2019Assignee: CANON KABUSHIKI KAISHAInventors: Shinnosuke Koji, Sakae Suda, Yusuke Kosaki, Shohei Fukuya, Tetsuya Kinumatsu, Kenji Aoki, Toshifumi Mori, Shuntaro Watanabe, Noritaka Toyoizumi, Atsushi Tani, Kazumichi Nakahama
-
Publication number: 20190235407Abstract: 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.Type: ApplicationFiled: January 17, 2019Publication date: August 1, 2019Inventors: Kunihiko Nakamura, Kenta Kamikura, Maho Tanaka, Yusuke Kosaki
-
Publication number: 20190235404Abstract: 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.Type: ApplicationFiled: January 22, 2019Publication date: August 1, 2019Inventors: Kenta Kamikura, Kunihiko Nakamura, Maho Tanaka, Yusuke Kosaki
-
Publication number: 20190235403Abstract: 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 nm2 to 5000 nm2, and a coefficient of variation of the area of the reaction product is not more than 10.0.Type: ApplicationFiled: January 22, 2019Publication date: August 1, 2019Inventors: Maho Tanaka, Kunihiko Nakamura, Kenta Kamikura, Yusuke Kosaki
-
Patent number: 10303075Abstract: 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 %.Type: GrantFiled: February 23, 2018Date of Patent: May 28, 2019Assignee: CANON KABUSHIKI KAISHAInventors: Keisuke Tanaka, Yojiro Hotta, Kazuo Terauchi, Koji Nishikawa, Takaaki Furui, Ryo Nagata, Kazuyuki Sato, Yu Yoshida, Yusuke Kosaki, Masami Fujimoto
-
Patent number: 10295920Abstract: 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°±0.150° and a peak in the range of 46.200°±0.150° in a CuK? x-ray diffraction spectrum obtained in the 2? range of at least 10° and not more than 90° where ? is the Bragg angle, and the ratio of the area Sb of the peak at 46.200°±0.150° to the area Sa of the peak at 39.700°±0.150° is at least 1.80 and not more than 2.30.Type: GrantFiled: February 21, 2018Date of Patent: May 21, 2019Assignee: CANON KABUSHIKI KAISHAInventors: Koji Nishikawa, Yojiro Hotta, Kazuo Terauchi, Takaaki Furui, Ryo Nagata, Keisuke Tanaka, Kazuyuki Sato, Yu Yoshida, Yusuke Kosaki, Masami Fujimoto
-
Patent number: 10078280Abstract: 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.Type: GrantFiled: June 14, 2017Date of Patent: September 18, 2018Assignee: Canon Kabushiki KaishaInventors: Kenji Aoki, Yusuke Kosaki, Noritaka Toyoizumi, Tetsuya Kinumatsu, Toshifumi Mori, Sakae Suda, Shinnosuke Koji, Shuntaro Watanabe, Kazumichi Nakahama, Atsushi Tani, Takashige Kasuya
-
Publication number: 20180246432Abstract: 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°±0.150° and a peak in the range of 46.200°±0.150° in a CuK? x-ray diffraction spectrum obtained in the 2? range of at least 10° and not more than 90° where ? is the Bragg angle, and the ratio of the area Sb of the peak at 46.200°±0.150° to the area Sa of the peak at 39.700°±0.150° is at least 1.80 and not more than 2.30.Type: ApplicationFiled: February 21, 2018Publication date: August 30, 2018Inventors: Koji Nishikawa, Yojiro Hotta, Kazuo Terauchi, Takaaki Furui, Ryo Nagata, Keisuke Tanaka, Kazuyuki Sato, Yu Yoshida, Yusuke Kosaki, Masami Fujimoto
-
Publication number: 20180246430Abstract: 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 %.Type: ApplicationFiled: February 23, 2018Publication date: August 30, 2018Inventors: Keisuke Tanaka, Yojiro Hotta, Kazuo Terauchi, Koji Nishikawa, Takaaki Furui, Ryo Nagata, Kazuyuki Sato, Yu Yoshida, Yusuke Kosaki, Masami Fujimoto
-
Publication number: 20180231901Abstract: 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.Type: ApplicationFiled: February 6, 2018Publication date: August 16, 2018Inventors: Shinnosuke Koji, Sakae Suda, Yusuke Kosaki, Shohei Fukuya, Tetsuya Kinumatsu, Kenji Aoki, Toshifumi Mori, Shuntaro Watanabe, Noritaka Toyoizumi, Atsushi Tani, Kazumichi Nakahama