Patents by Inventor Kenta Kamikura
Kenta Kamikura 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).
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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
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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
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Publication number: 20190384200Abstract: The toner has a toner particle in which a toner core containing a binder resin is coated with a shell layer, wherein the binder resin contains a polymer A that has a first monomer unit and a second monomer unit; the first unit is derived from (meth)acrylate ester having an alkyl group having 18 to 36 carbon atoms; the content of the first monomer unit in the polymer is 5.0 to 60.0 mol %; the content of the second monomer unit is 20.0 to 95.0 mol %; the following formula (1) is satisfied when the SP value of the first unit is denoted by SP11 and the SP value of the second unit is denoted by SP21; and the toner core is coated with a highly uniform shell over at least 90% of the circumference of the toner cross section; 3.00?(SP21?SP11)?25.00??(1).Type: ApplicationFiled: June 12, 2019Publication date: December 19, 2019Inventors: Kenta Kamikura, Takashi Matsui, Kenji Aoki, Masao Suzuki, Tsutomu Shimano, Reo Tagawa
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Publication number: 20190384198Abstract: Provided is a toner has a toner particle containing a binder resin and is characterized in that the binder resin contains a polymer A, which is a polymer of a composition containing a first polymerizable monomer, a second polymerizable monomer and a crosslinking agent, the first polymerizable monomer is at least one monomer selected from the group consisting of (meth)acrylic acid esters having an alkyl group with 18 to 36 carbon atoms, the crosslinking agent has two or more polymerizable double bonds, a content of the first polymerizable monomer in the composition is 5.0 to 60.0 mol %, a content of the second polymerizable monomer is 20.0 to 95.0 mol %, and when the SP values of the first polymerizable monomer, the second polymerizable monomer and the crosslinking agent are denoted by SP12, SP22 and SPC2, respectively, the formulae 0.60?(SP22?SP12)?15.00 and SP12<SPC2<(SP22+3.00) are satisfied.Type: ApplicationFiled: June 12, 2019Publication date: December 19, 2019Inventors: Takashi Matsui, Kenta Kamikura, Kenji Aoki, Masao Suzuki, Tsutomu Shimano, Reo Tagawa
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Publication number: 20190384197Abstract: A toner, including a toner particle that contains a binder resin and a release agent, wherein the binder resin contains a polymer A, the polymer A including a first monomer unit derived from a first polymerizable monomer and a second monomer unit derived from a second polymerizable monomer different from the first polymerizable monomer; the first polymerizable monomer is selected from (meth)acrylic acid esters having a C18-36 alkyl group; the toner has a first monomer unit content and a second monomer unit content in the polymer A which are within specific ranges, and assuming that an SP value of the first monomer unit is taken as SP11 and an SP value of the second monomer unit is taken as SP21, the formula (1) below is satisfied, and the molecular weight of the release agent is at least 1,000. 3.00?(SP21?SP11)?25.Type: ApplicationFiled: June 12, 2019Publication date: December 19, 2019Inventors: Kenji Aoki, Takashi Matsui, Kenta Kamikura, Masao Suzuki, Tsutomu Shimano, Reo Tagawa
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Patent number: 10503090Abstract: 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.Type: GrantFiled: May 2, 2018Date of Patent: December 10, 2019Assignee: CANON KABUSHIKI KAISHAInventors: Tsuneyoshi Tominaga, Akane Masumoto, Toshihiko Katakura, Shiro Kuroki, Kenta Kamikura, Sara Yoshida, Shinsuke Mochizuki, Tsutomu Shimano, Kentaro Yamawaki, Tomonori Matsunaga, Kunihiko Nakamura
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Patent number: 10429757Abstract: 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 P1 and P2 and a minimum value V between P1 and P2, P2 originates from the organosilicon polymer, and the luminance giving P1 and P2 are in specific ranges, percentages for P1 and P2 are each at least 0.50%, and using the luminance Bl at V as a reference point, specific relationships are satisfied by A1, AV, and A2, where A1 is the total number of pixels at luminance from 0 to (Bl?30 ), AV is the total number of pixels at luminance from (Bl?29 ) to (Bl+29 ), and A2 is the total number of pixels at luminance from (Bl+30 ) to 255.Type: GrantFiled: May 8, 2018Date of Patent: October 1, 2019Assignee: Canon Kabushiki KaishaInventors: Sara Yoshida, Shinsuke Mochizuki, Tsuneyoshi Tominaga, Kenta Kamikura, Tsutomu Shimano, Kentaro Yamawaki, Akane Masumoto, Tomonori Matsunaga, Kunihiko Nakamura, Toshihiko Katakura, Shiro Kuroki
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Publication number: 20190271926Abstract: A toner including: a toner particle including a toner base particle containing a binder resin, and an organosilicon condensate present on a surface of the toner base particle, wherein a charge attenuation constant of the toner is 3.5×10?3 or more to 1.0×100 or less.Type: ApplicationFiled: May 21, 2019Publication date: September 5, 2019Inventors: Kenta Kamikura, Kunihiko Nakamura, Maho Tanaka, Fumiya Hatakeyama
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Patent number: 10401750Abstract: Provided is a toner comprising a toner particle including a toner base particle and fine particles present on a surface of the toner base particle, wherein each of the fine particles includes a core fine particle and a condensate of at least one organosilicon compound selected from the group consisting of organosilicon compounds represented by specific structural formulas, the condensate coating the surface of the core fine particle, and in a wettability test of the toner with respect to a methanol/water mixed solvent, a methanol concentration, when a transmittance of light having a wavelength of 780 nm is 50%, is 5.0 to 20.0% by volume: in above Formulas, each of Ra, Rb and Rc independently represents an alkyl group, an alkenyl group, an acetoxy group, an acyl group, an aryl group, or a methacryloxyalkyl group, R1 to R5 each independently represents a halogen atom or an alkoxy group.Type: GrantFiled: May 9, 2018Date of Patent: September 3, 2019Assignee: CANON KABUSHIKI KAISHAInventors: Kunihiko Nakamura, Kenta Kamikura, Maho Tanaka, Fumiya Hatakeyama
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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
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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
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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
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Publication number: 20190235406Abstract: A toner comprising a binder resin and a colorant, wherein the toner has a Martens hardness, as measured at a maximum load condition of 2.0×10?4 N, of from 200 MPa to 1,100 MPa.Type: ApplicationFiled: April 8, 2019Publication date: August 1, 2019Inventors: Kentaro Yamawaki, Akane Masumoto, Tomonori Matsunaga, Kunihiko Nakamura, Sara Yoshida, Shinsuke Mochizuki, Tsuneyoshi Tominaga, Kenta Kamikura, Tsutomu Shimano, Toshihiko Katakura, Shiro Kuroki
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Patent number: 10353308Abstract: Provided is a toner, including a toner particle containing a toner base particle and a fine particle, wherein the fine particle includes a composite particle each having a surface covered with a condensation product of at least one kind of organosilicon compound selected from the group consisting of a compound represented by the following formula (1) and a compound represented by the following formula (2), wherein the fine particle is stuck in a state of being embedded in a surface of the toner base particle, and wherein a coverage of a composition containing the organosilicon compound with respect to the surface of the toner base particle excluding the fine particle is 0.1% by area or more and 40.Type: GrantFiled: May 9, 2018Date of Patent: July 16, 2019Assignee: CANON KABUSHIKI KAISHAInventors: Fumiya Hatakeyama, Kunihiko Nakamura, Kenta Kamikura, Maho Tanaka
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Patent number: 10345726Abstract: There is provided a method of manufacturing a toner including a toner particle containing a binder resin, the method including: process 1: preparing a mixed solution including the following components i) to iii) in an aqueous medium: i) a particular silicon compound, ii) a fine particle having a number average particle diameter of 3 nm or more and 500 nm or less, and iii) a toner base particle containing the binder resin; and process 2: adjusting a pH of the mixed solution to 7.0 or more and 12.0 or less to condense the silicon compound, wherein the fine particle has an absolute value of zeta potential of 10.0 mV or more at the pH of the mixed solution of process 1.Type: GrantFiled: May 9, 2018Date of Patent: July 9, 2019Assignee: CANON KABUSHIKI KAISHAInventors: Kunihiko Nakamura, Kenta Kamikura, Maho Tanaka, Fumiya Hatakeyama
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Patent number: 10338487Abstract: A toner including: a toner particle including a toner base particle containing a binder resin, and an organosilicon condensate present on a surface of the toner base particle, wherein a charge attenuation constant of the toner is 3.5×10?3 or more to 1.0×100 or less.Type: GrantFiled: May 8, 2018Date of Patent: July 2, 2019Assignee: CANON KABUSHIKI KAISHAInventors: Kenta Kamikura, Kunihiko Nakamura, Maho Tanaka, Fumiya Hatakeyama
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Patent number: 10324399Abstract: 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 P1 and P2 and a local minimum V between P1 and P2. P2 is derived from an organosilicon polymer. P1 lies in a brightness range of 20 to 70, and P2 lies in a brightness range of 130 to 230. The number of pixels of P1 and the number of pixels of P2 are each 0.50% or more relative to the total number of pixels. The total numbers of pixels A1, AV, and A2 each in a specific brightness range satisfy specific relationships.Type: GrantFiled: August 22, 2018Date of Patent: June 18, 2019Assignee: Canon Kabushiki KaishaInventors: Yasutaka Yagi, Sara Yoshida, Shinsuke Mochizuki, Tsuneyoshi Tominaga, Kenta Kamikura, Tsutomu Shimano
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Patent number: 10310396Abstract: A first aspect is a toner production method in which an organosilicon compound is condensed in a surfactant-containing aqueous medium with a specific surface tension, in which a resin particle is dispersed, to produce a toner having the condensate of the organosilicon compound on the surface of the resin particle, and a second aspect is a toner production method in which an organosilicon compound is condensed in an aqueous medium which has a surfactant and a specific metal salt and in which a resin particle is dispersed, to produce a toner having the condensate of the organosilicon compound on the surface of the resin particle.Type: GrantFiled: May 9, 2018Date of Patent: June 4, 2019Assignee: CANON KABUSHIKI KAISHAInventors: Kenta Kamikura, Kunihiko Nakamura, Maho Tanaka, Fumiya Hatakeyama
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Patent number: 10303074Abstract: A toner comprising a binder resin and a colorant, wherein the toner has a Martens hardness, as measured at a maximum load condition of 2.0×10?4 N, of from 200 MPa to 1,100 MPa.Type: GrantFiled: May 9, 2018Date of Patent: May 28, 2019Assignee: CANON KABUSHIKI KAISHAInventors: Kentaro Yamawaki, Akane Masumoto, Tomonori Matsunaga, Kunihiko Nakamura, Sara Yoshida, Shinsuke Mochizuki, Tsuneyoshi Tominaga, Kenta Kamikura, Tsutomu Shimano, Toshihiko Katakura, Shiro Kuroki
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Publication number: 20190064705Abstract: 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 P1 and P2 and a local minimum between P1 and P2. P2 is derived from the organosilicon polymer. P1 lies in a brightness range of 20 to 70, and P2 lies in a brightness range of 130 to 230. The number of pixels of P1 and the number of pixels of P2 are each 0.50% or more relative to the total number of pixels. The total numbers of pixels A1, AV, and A2 each in a specific brightness range satisfy specific relationships.Type: ApplicationFiled: August 22, 2018Publication date: February 28, 2019Inventors: Yasutaka Yagi, Sara Yoshida, Shinsuke Mochizuki, Tsuneyoshi Tominaga, Kenta Kamikura, Tsutomu Shimano