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).

  • Publication number: 20240061355
    Abstract: A toner comprising a toner particle, the toner particle comprising a binder resin, wherein the toner particle comprises a monoester wax, and a fatty acid metal salt A is present on a surface of the toner particle, when X(A) is defined as a coverage ratio of the surface of the toner particle by the fatty acid metal salt A, as determined by X-ray photoelectron spectroscopy and S(A) is defined as the coverage ratio of the surface of the toner particle by the fatty acid metal salt A, as determined by analysis of a scanning electron microscope image, the formulae below are satisfied: S(A)?0.03??(1) X(A)?0.250??(2) 0.248?S(A)/X(A)?1.000??(3).
    Type: Application
    Filed: July 27, 2023
    Publication date: February 22, 2024
    Inventors: YUTA KOMIYA, KOSUKE FUKUDOME, KENTA KAMIKURA, SATOSHI ARIMURA, TORU ISHII, SHOHEI TSUDA
  • Publication number: 20240053691
    Abstract: A toner comprising a toner particle comprising a resin A and a resin B; wherein: the resin A is a vinyl resin having a sulfonic acid-type group, the resin B is a polyester resin; and when in analysis of the toner particle using time-of-flight secondary ion mass spectrometry, DA (nm) is defined as a depth at which an abundance of the resin A in a depth of 10 nm from a toner particle surface is a maximum, CAS (%) is defined as an abundance of the resin A at the depth DA, CBS (%) is defined as an abundance of the resin B at the depth DA, CA75 (%) is defined as an abundance of the resin A at a depth of 75 nm and CB75 (%) is defined as an abundance of the resin B at a depth of 75 nm, CAS, CA75, CBS and CB75 satisfy specific relationships.
    Type: Application
    Filed: July 27, 2023
    Publication date: February 15, 2024
    Inventors: KENTA KAMIKURA, KOSUKE FUKUDOME, SHOHEI TSUDA, SATOSHI ARIMURA, TORU ISHII, YUTA KOMIYA
  • Patent number: 11899395
    Abstract: A toner comprising a toner particle, wherein the toner particle includes a toner base particle containing a binder resin and includes a protruded portion on a surface of the toner base particle; the protruded portion comprises an organosilicon polymer and a polyhydric acid metal salt; and the polyhydric acid metal salt is present on a surface of the protruded portion.
    Type: Grant
    Filed: November 9, 2022
    Date of Patent: February 13, 2024
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Kenta Kamikura, Takashi Kenmoku, Noritaka Toyoizumi, Akane Masumoto, Yuzo Seino, Yu Yoshida
  • Publication number: 20240036489
    Abstract: A toner comprising a toner particle, the toner particle comprising a binder resin and a boric acid, wherein, where the toner particle is subjected to ATR-IR analysis by using germanium as an ATR crystal in an ATR method, a peak corresponding to the boric acid is detected, the toner comprises a fatty acid metal salt on a surface of the toner particle, and a presence ratio of an boron element on the surface of the toner particle is 0.01 atomic % or less as measured by X-ray photoelectron spectroscopy.
    Type: Application
    Filed: July 19, 2023
    Publication date: February 1, 2024
    Inventors: SATOSHI ARIMURA, KOSUKE FUKUDOME, KENTA KAMIKURA, SHOHEI TSUDA, YUTA KOMIYA, TORU ISHII
  • Publication number: 20230314974
    Abstract: A toner comprising a toner particle comprising a binder resin, and a strontium titanate particle and a hydrotalcite particle on a surface of the toner particle, wherein the hydrotalcite particle comprises fluorine, the fluorine is present inside the hydrotalcite particle in line analysis of STEM-EDS mapping analysis of the toner, and when an area ratio of the strontium titanate particle to the toner particle in an EDS measurement field, which is measured through the STEM-EDS mapping analysis of the toner, is defined as T1 (%) and an area ratio of the hydrotalcite particle to the toner particle in the EDS measurement field, which is measured through the STEM-EDS mapping analysis of the toner, is defined as H1 (%), T1/H1 is 0.15 to 9.00.
    Type: Application
    Filed: February 23, 2023
    Publication date: October 5, 2023
    Inventors: SHOHEI TSUDA, KENTA KAMIKURA, KOSUKE FUKUDOME, YUTA KOMIYA, SATOSHI ARIMURA, TORU ISHII
  • Publication number: 20230273538
    Abstract: A toner comprising a toner particle comprising a binder resin, a fatty acid metal salt particle on a surface of the toner particle, and a hydrotalcite particle on a surface of the toner particle, wherein the hydrotalcite particle comprises fluorine, the fluorine is present inside the hydrotalcite particle in line analysis of STEM-EDS mapping analysis of the toner, and when an area ratio of the fatty acid metal salt particle to the toner particle in an EDS measurement field, which is measured through the STEM-EDS mapping analysis of the toner, is defined as Si (%) and an area ratio of the hydrotalcite particle to the toner particle in the EDS measurement field, which is measured through the STEM-EDS mapping analysis of the toner, is defined as H1 (%), S1/H1 is 0.25 to 9.00.
    Type: Application
    Filed: February 23, 2023
    Publication date: August 31, 2023
    Inventors: KOSUKE FUKUDOME, SHOHEI TSUDA, KENTA KAMIKURA, SATOSHI ARIMURA, TORU ISHII, YUTA KOMIYA
  • Publication number: 20230117448
    Abstract: A toner comprising a toner particle comprising a binder resin and an ester compound, wherein: the binder resin comprises a resin A comprising a specific amount of a long-chain acrylate unit and a styrene-based monomer unit, and a resin B comprising a specific monomer unit in a specific amount; the ester compound has an alkyl chain with a specific chain length, a content of the resin A in the chloroform-soluble portion of the toner particles is 60% by mass or more; and using SPm (J/cm3)1/2 for a SP value of the long-chain acrylate unit and using SPw (J/cm3)1/2 for a SP value of the ester compound, SPm is 18.00 to 19.00, and SPm and SPw satisfy formula (a). |SPm?SPw|?1.
    Type: Application
    Filed: October 14, 2022
    Publication date: April 20, 2023
    Inventors: Kosuke Fukudome, Kenta Kamikura, Kozue Uratani, Tetsuya Kinumatsu, Yuta Komiya
  • Publication number: 20230122974
    Abstract: A magnetic toner comprising a toner particle comprising a binder resin and a magnetic body, wherein the binder resin comprises a styrene-acrylic resin, the styrene-acrylic resin comprises a monomer unit represented by Formula (1): where, in Formula (1), R1 represents a hydrogen atom or a methyl group; and R2 represents a linear alkyl group having CB carbon atoms, CB being an integer from 10 to 15; the magnetic body comprises an alkyl group having CM carbon atoms, on a surface of the magnetic body, CM being an integer from 4 to 20; CB and CM satisfy Formula (3): |CM?CB|?10??(3), and in a cross-sectional observation of the magnetic toner using a transmission electron microscope, a coefficient of variation of an occupied area ratio of the magnetic body in a specific square grid, is 80.0% or lower.
    Type: Application
    Filed: October 14, 2022
    Publication date: April 20, 2023
    Inventors: Hiroki Kagawa, Kenta Kamikura, Kosuke Fukudome, Atsuhiko Ohmori
  • Publication number: 20230080900
    Abstract: A toner comprising a toner particle, wherein the toner particle includes a toner base particle containing a binder resin and includes a protruded portion on a surface of the toner base particle; the protruded portion comprises an organosilicon polymer and a polyhydric acid metal salt; and the polyhydric acid metal salt is present on a surface of the protruded portion.
    Type: Application
    Filed: November 9, 2022
    Publication date: March 16, 2023
    Inventors: Kenta Kamikura, Takashi Kenmoku, Noritaka Toyoizumi, Akane Masumoto, Yuzo Seino, Yu Yoshida
  • Patent number: 11573499
    Abstract: Provided is a process cartridge detachably attachable to a main body of an electrophotographic apparatus, the process cartridge including: a developing unit including a toner; and an electrophotographic photosensitive member, wherein the toner includes a toner particle, the toner particle has a surface containing a polyvalent acid metal salt particle, and a surface layer of the electrophotographic photosensitive member contains at least one metal oxide particle among an aluminum oxide particle, a silicon dioxide particle, and a tin oxide particle.
    Type: Grant
    Filed: July 21, 2020
    Date of Patent: February 7, 2023
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Takeshi Murakami, Kazunori Noguchi, Harunobu Ogaki, Kenta Kamikura, Yuzo Seino, Takashi Kenmoku
  • Patent number: 11531282
    Abstract: A toner comprising a toner particle, wherein the toner particle includes a toner base particle containing a binder resin and includes a protruded portion on a surface of the toner base particle; the protruded portion comprises an organosilicon polymer and a polyhydric acid metal salt; and the polyhydric acid metal salt is present on a surface of the protruded portion.
    Type: Grant
    Filed: July 22, 2020
    Date of Patent: December 20, 2022
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Kenta Kamikura, Takashi Kenmoku, Noritaka Toyoizumi, Akane Masumoto, Yuzo Seino, Yu Yoshida
  • Patent number: 11392068
    Abstract: In an image forming apparatus, a fixing member has a surface layer having conductivity. A developer is a toner having a toner particle including a binder resin, a reactant of a polyhydric acid and a compound containing a group 4 element is present on a surface of the toner particle, and Tv/Fv>100 is satisfied where Tv represents a volume resistivity upon being unfixed, and Fv represents a volume resistivity after fixing. A bias applying unit can selectively apply a bias of a positive polarity and a bias of a negative polarity, and applies a bias of the same polarity as the charged polarity of a filler included in a recording material when the recording material passes through a fixing nip portion, and when the recording material does not pass through the fixing nip portion, respectively.
    Type: Grant
    Filed: August 2, 2021
    Date of Patent: July 19, 2022
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Tohru Saito, Yoshiro Saito, Akihiko Uchiyama, Tomoaki Nakai, Kenta Kamikura, Yuzo Seino
  • Publication number: 20220214630
    Abstract: The present disclosure provides a toner that achieves both high image gloss and high image loadability. The toner includes a toner particle that includes: a styrene-acrylic resin having a unit represented by the formula (1); and an ester compound A, wherein the ester compound A is an ester compound represented by the formula (2) or the formula (3): and an absolute value of a difference between SPb (J/cm3)1/2 that is an SP value of the styrene-acrylic resin and SPw1 (J/cm3)1/2 that is an SP value of the ester compound A is 1.00 or larger and 2.00 or smaller.
    Type: Application
    Filed: December 9, 2021
    Publication date: July 7, 2022
    Inventors: Kenta Kamikura, Kozue Uratani, Kosuke Fukudome, Tetsuya Kinumatsu, Takuya Mizuguchi, Yuta Komiya
  • Publication number: 20220214629
    Abstract: A toner containing a toner particle, wherein, when a dielectric loss tangent measured at a frequency of 10 kHz in an impedance measurement on the toner in an environment having a temperature of 50° C. and a relative humidity of 50% RH is designated by tan?50° C.(1), and a dielectric loss tangent measured at a frequency of 10 kHz in an impedance measurement on the toner in an environment having a temperature of 30° C. and a relative humidity of 50% RH after the impedance measurement on the toner in an environment having a temperature of 50° C. and a relative humidity of 50% RH is designated by tan?30° C.(2), tan?50° C.(1) is from 0.015 to 0.050, the relationship tan?50° C.(1)>tan?30° C.(2) is satisfied, and tan?30° C.(2)/tan?50° C.(1) is from 0.25 to 0.66.
    Type: Application
    Filed: March 16, 2022
    Publication date: July 7, 2022
    Inventors: Takashi Kenmoku, Kenta Kamikura, Yuzo Seino
  • Publication number: 20220206402
    Abstract: A toner including a toner particle containing a binder resin and an ester compound, wherein the binder resin contains a styrene-acrylic-based resin, the styrene-acrylic-based resin contains a specific unit, the ester compound has a specific structure, and a molar ratio of the specific unit to the ester compound is 0.5 to 1.5.
    Type: Application
    Filed: December 13, 2021
    Publication date: June 30, 2022
    Inventors: Kozue Uratani, Kenta Kamikura, Kosuke Fukudome, Tetsuya Kinumatsu, Takuya Mizuguchi, Yuta Komiya
  • Patent number: 11347157
    Abstract: A toner comprising a toner particle, wherein the toner has G1 of from 5.0×10?13 to 1.0×10?10, and a ratio G2/G1 of G2 to G1 is from 0.10 to 0.60, when a conductivity of the toner measured at a frequency of 0.01 Hz under a pressure of 1,000 kPa is designated by G1 in S/m, and a conductivity of the toner measured at a frequency of 0.01 Hz under a pressure of 100 kPa is designated by G2 in S/m.
    Type: Grant
    Filed: July 22, 2020
    Date of Patent: May 31, 2022
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Kenta Kamikura, Takashi Kenmoku, Yuzo Seino
  • Publication number: 20220155700
    Abstract: A developing apparatus comprising a toner and a toner bearing member for bearing the toner, wherein the volume resistivity of the toner is from 1.0×1010 ?·cm to 1.0×1014 ?·cm, a toner bearing member exhibits multiple elementary processes, the volume resistance value Rdr per unit area of the toner bearing member is from 5.0×105 ?/cm2 to 2.0×108 ?/cm2, the capacitance Cdr per unit area of the toner bearing member is from 300 pF/cm2 to 900 pF/cm2, and the capacitance per unit area and volume resistance value of the toner as converted by a parallel plate capacitor model at a thickness of 1.5 times the weight-average particle diameter of the toner are in specific relationships.
    Type: Application
    Filed: November 11, 2021
    Publication date: May 19, 2022
    Inventors: Yuzo Seino, Kenta Kamikura, Noriyuki Doi, Takuho Sato
  • Patent number: 11320754
    Abstract: The present disclosure provides a process cartridge and an electrophotographic apparatus in which fogging is reduced so as to reduce an amount of toner consumed. A process cartridge configured to be detachably attachable to a main body of an electrophotographic apparatus includes a developing unit containing a toner, and an electrophotographic photosensitive member, wherein the toner is a toner that has a toner particle, and has a metal salt of a polyvalent acid at least on a part of a surface of the toner particle; wherein the metal salt of the polyvalent acid includes at least one kind of metal element selected from metal elements belonging to from Group 3 to Group 13, and a surface layer of the electrophotographic photosensitive member contains an acrylic resin or a methacrylic resin.
    Type: Grant
    Filed: July 21, 2020
    Date of Patent: May 3, 2022
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Kazunori Noguchi, Takeshi Murakami, Harunobu Ogaki, Kenta Kamikura, Yuzo Seino, Takashi Kenmoku
  • Patent number: 11314178
    Abstract: A toner containing a toner particle, wherein, when a dielectric loss tangent measured at a frequency of 10 kHz in an impedance measurement on the toner in an environment having a temperature of 50° C. and a relative humidity of 50% RH is designated by tan ?50° C.(1), and a dielectric loss tangent measured at a frequency of 10 kHz in an impedance measurement on the toner in an environment having a temperature of 30° C. and a relative humidity of 50% RH after the impedance measurement on the toner in an environment having a temperature of 50° C. and a relative humidity of 50% RH is designated by tan ?30° C.(2), tan ?50° C.(1) is from 0.015 to 0.050, the relationship tan ?50° C.(1)>tan ?30° C.(2) is satisfied, and tan ?30° C.(2)/tan ?50° C.(1) is from 0.25 to 0.66.
    Type: Grant
    Filed: July 22, 2020
    Date of Patent: April 26, 2022
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Takashi Kenmoku, Kenta Kamikura, Yuzo Seino
  • Patent number: 11287758
    Abstract: 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: Grant
    Filed: June 22, 2020
    Date of Patent: March 29, 2022
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Takashi Matsui, Kenta Kamikura, Kenji Aoki, Masao Suzuki, Tsutomu Shimano, Reo Tagawa