Patents by Inventor Shohei Kototani

Shohei Kototani 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: 20240036493
    Abstract: A cartridge comprising: a toner; a developing roller; a supply member abutting the surface of the developing roller a regulating member regulating the toner carried on the surface of the developing roller, wherein the cartridge comprises a first supply electrode to which a voltage is supplied from outside of the cartridge, the supply member and the regulating member are electrically connected to the same first supply electrode, the toner comprises a compound A having a structure represented by Formula (1) below, —(CH2CH2O)—??(1) the compound A is eluted in methanol a supernatant comprising the compound A is analyzed by liquid chromatograph ESI/MS, a specific peak of which an average m/z is 300 to 1000 exists.
    Type: Application
    Filed: July 19, 2023
    Publication date: February 1, 2024
    Inventors: SHOHEI KOTOTANI, MASATAKE TANAKA, YOSUKE SUGITANI, DAISUKE BABA, TAKASHI HIRAMATSU
  • Publication number: 20240027930
    Abstract: A toner comprising a toner particle, the toner particle comprising: a binder resin and a wax; wherein the toner particle has a toner core particle and a protrusion present on the surface of the toner core particle, the protrusion comprises an organosilicon polymer, where in cross-sectional observation of the toner particle, a line segment connecting both ends of an interface between the toner core particle and the protrusion is defined as a reference line, and the length of the reference line is denoted by W (nm), and a maximum length of the protrusion in the toner core particle direction from the reference line in the normal direction of the reference line is defined as a maximum penetration depth I (nm), W and I satisfy I/W?0.050, and Young's modulus of the protrusion E1 is 1.00 to 3.90 GPa.
    Type: Application
    Filed: July 11, 2023
    Publication date: January 25, 2024
    Inventors: SHOHEI KOTOTANI, TAKASHI KENMOKU, YOSHIAKI SHIOTARI, MAYUMI INOUE, KOZUE URATANI
  • Publication number: 20240019793
    Abstract: A toner comprising a toner particle, wherein the toner particle comprises a toner core particle, and the toner core particle comprises a binder resin; the binder resin comprises a resin A; the resin A comprises a monomer unit M1 having a specific structure in a specific amount, and a monomer unit M2 comprising an organosilicon polymer segment in a specific amount; the organosilicon polymer segment has a T3 unit structure and a T2 unit structure; in a DD/MAS measurement of the resin A by solid-state 29Si-NMR, a proportion of a peak area corresponding to a silicon atom with the T3 unit structure, and a proportion of a peak area corresponding to a silicon atom with the T2 unit structure satisfy a specific relationship; and the weight-average molecular weight Mw of a tetrahydrofuran-soluble fraction of the resin A lies within a specific range.
    Type: Application
    Filed: July 11, 2023
    Publication date: January 18, 2024
    Inventors: YOSHIAKI SHIOTARI, TAKASHI KENMOKU, SHOHEI KOTOTANI, MAYUMI INOUE
  • Publication number: 20240019791
    Abstract: A toner comprising a toner particle, wherein the toner particle comprises a binder resin and wax, and where with respect to a slope X of a straight line obtained by performing a micro-compression test on the toner, obtaining a relationship of a deformation amount (?m) to a load (mN), calculating a percentage deformation (%), which is a ratio of the deformation amount to a particle diameter of the particle measured, plotting a load (mN)?percentage deformation (%) plot, and then using all the points plotted within the range in which the percentage deformation was 15% or less of the particle diameter of the particle for approximation by a least squares method, the slope X measured at 30° C. is denoted by X30 and the slope X measured at 45° C. is denoted by X45, the X30 is 25 to 300, and the X45 is 400 to 1000.
    Type: Application
    Filed: July 11, 2023
    Publication date: January 18, 2024
    Inventors: MAYUMI INOUE, TAKASHI KENMOKU, YOSHIAKI SHIOTARI, SHOHEI KOTOTANI, KOZUE URATANI
  • Publication number: 20220413407
    Abstract: A toner, comprising a toner particle, wherein the toner particle has a core-shell structure comprising a core particle and a shell on a surface of the core particle, the shell comprises a polymer having monomer units represented by Formula (I) below, the toner comprises a specific external additive A, the external additive A is at least one selected from the group consisting of silica fine particles and organosilicon polymer fine particles, and a ratio of coverage of a surface of the toner particle with the external additive A is 0.3 area % or higher: in Formula (I), L1 represents —COO(CH2)n— (where n is an integer of 1 to 10), and carbonyl of L1 is bonded to a carbon atom of a main chain; R1 represents hydrogen or a methyl group; and R2 to R10 represent each independently an alkyl group having 1 to 4 carbon atoms.
    Type: Application
    Filed: June 14, 2022
    Publication date: December 29, 2022
    Inventors: Mayumi Inoue, Takashi Kenmoku, Yoshiaki Shiotari, Shohei Kototani
  • Patent number: 11448982
    Abstract: An electrophotographic apparatus including an electrophotographic photosensitive member, a charging unit, and a developing unit, wherein the charging unit includes a conductive member disposed to be contactable with the electrophotographic photosensitive member, a conductive layer of the conductive member has a matrix-domain structure, at least some of the domains are exposed at the outer surface of the conductive member, the volume resistivity RI of the matrix is greater than 1.00×1012 ?·cm and not greater than 1.00×1017 ?·cm, the matrix volume resistivity R1 is at least 1.0×105-times the domain volume resistivity R2, and the developing unit includes a toner, the toner includes a binder resin-containing toner particle and an external additive, and the external additive contains fine particles of a hydrotalcite compound.
    Type: Grant
    Filed: October 15, 2020
    Date of Patent: September 20, 2022
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Tsuneyoshi Tominaga, Shohei Tsuda, Shohei Kototani, Noriyoshi Umeda, Masahiro Kurachi, Kazuhiro Yamauchi, Motonari Ito
  • Patent number: 11320756
    Abstract: An electrophotographic apparatus comprising an electrophotographic photosensitive member, a charging unit, and a developing unit, wherein the charging unit has a conductive member contactable with the electrophotographic photosensitive member, and a conductive layer of the conductive member has a matrix-domain structure; at least some of the domains are exposed at the outer surface; a volume resistivity R1 of the matrix and a volume resistivity R2 of the domains satisfy specific relationship; Martens hardness G1 of the matrix and Martens hardness G2 of the domains satisfy relationship G1<G2; the surface roughness Ra of the conductive member is not more than 2.00 ?m; the toner has an external additive having a shape factor SF-1 of not more than 115; and A<Dms is satisfied where A is the number-average diameter of the external additive and Dms is a distance between adjacent walls between the domains.
    Type: Grant
    Filed: October 15, 2020
    Date of Patent: May 3, 2022
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Shohei Kototani, Noriyoshi Umeda, Tsuneyoshi Tominaga, Shohei Tsuda, Noboru Miyagawa, Kazuhiro Yamauchi
  • Publication number: 20220128918
    Abstract: A toner comprising a toner particle comprising a binder resin, wherein the toner particle comprises a condensation product of an organosilicon compound, in time-of-flight secondary ion mass spectrometry of the toner particle, a normalized intensity of silicon ions derived from the condensation product of the organosilicon compound is from 7.00×10?4 to 3.00×10?2, a normalized intensity of silicon ions after sputtering the toner particle under a specific condition is 6.99×10?4 or lower, the toner comprises a fine particle on the surface of the toner particle, and the fine particle has at least one selected from the group consisting of a specific fine particle of a polyhydric acid metal salt, a strontium titanate fine particle, a titanium oxide fine particle and an aluminum oxide fine particles.
    Type: Application
    Filed: October 15, 2021
    Publication date: April 28, 2022
    Inventors: Shohei Kototani, Takashi Kenmoku, Noritaka Toyoizumi, Yoshiaki Shiotari, Mayumi Inoue
  • Patent number: 11169460
    Abstract: A toner including a toner particle containing a binder resin, and an external additive, wherein the external additive contains an organosilicon polymer fine particle, the organosilicon polymer has a structure represented by at least one selected from the group consisting of RaSiO3/2 and Rb2SiO2/2 (wherein Ra and Rb represent organic groups), and in the number particle size distribution of the toner as measured within a particle size range of from 2 to 60 ?m, the number-average particle diameter T-D50n at which the accumulation from the smallest diameter is 50% is from 6 to 12 ?m, the number ratio of toner 4 ?m or less in size is from 2% to 5% of the total toner, and the number ratio of toner 3 ?m or less in size as a percentage of the total toner 4 ?m or less in size is from 25% to 50%.
    Type: Grant
    Filed: December 27, 2019
    Date of Patent: November 9, 2021
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Shohei Kototani, Kentaro Yamawaki, Tsuneyoshi Tominaga, Masatake Tanaka, Taiji Katsura, Masamichi Sato
  • Patent number: 11061342
    Abstract: An electrophotographic apparatus comprising an electrophotographic photosensitive member, a charging device, and a developing device, wherein the charging device comprises a conductive member arranged to be capable of contacting the electrophotographic photosensitive member, a conductive layer on the conductive member outer surface comprises a matrix and a plurality of domains dispersed in the matrix, at least some of the domains are exposed at the conductive member outer surface, the matrix has a volume resistivity of larger than 1.00×1012 ?·cm and is 1.0×105 times or more one of the domains, the developing device comprises the toner comprising a toner particle, fine particles A and B, the fine particle A has a volume resistivity of 1.0×103 to 1.0×1010 ?·cm, and the fine particle B is silica fine particle and having a volume resistivity of 1.0×1011 to 1.0×1017 ?·cm.
    Type: Grant
    Filed: October 15, 2020
    Date of Patent: July 13, 2021
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Noriyoshi Umeda, Tsuneyoshi Tominaga, Shohei Tsuda, Shohei Kototani, Masahiro Kurachi, Kazuhiro Yamauchi, Hideo Kihara
  • Patent number: 11022933
    Abstract: A process cartridge includes a seal member contacting an image bearing member upstream in the rotation direction of the image bearing member from a cleaning member and allowing the developer to move from upstream in the rotation direction from the contact part between the seal member and the image bearing to downstream from the contact part while regulating movement from downstream to upstream from the contact part. The developer has surface protrusions containing an organic silicon polymer, wherein either (i) the work function of the seal member is greater than the work function of the developer when the developer has a negative charging polarity and is smaller than the work function of the developer when the developer has a positive charging polarity, or (ii) the absolute value of the difference between the work function of the seal member and the work function of the developer is within a predetermined range.
    Type: Grant
    Filed: May 15, 2020
    Date of Patent: June 1, 2021
    Assignee: CANON KABUSHI KIKAISHA
    Inventors: Kazunori Hashimoto, Katsuhiro Kojima, Toshiaki Takeuchi, Yasukazu Ikami, Kosuke Ikada, Yoshihiro Mitsui, Yuichiro Hirata, Go Shindo, Akinobu Saito, Yuhei Terui, Noriyoshi Umeda, Tomonori Matsunaga, Shohei Kototani, Masamichi Sato
  • Patent number: 11003104
    Abstract: Provided is a toner including a toner particle and an external additive, wherein the external additive includes a composite particle including a hydrotalcite particle covered on the surface with an organosilicon polymer fine particle, a coverage ratio of the hydrotalcite particle surface by the organosilicon polymer fine particle is from 1% to 50%, and given A (nm) as the number-average particle diameter of the primary particles of the organosilicon polymer fine particle and B (nm) as the number-average particle diameter of the primary particles of the hydrotalcite particle, the toner satisfies the following formula (I) and formula (II): A<B??(I) 20?A?350??(II).
    Type: Grant
    Filed: December 27, 2019
    Date of Patent: May 11, 2021
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Taiji Katsura, Masamichi Sato, Shohei Kototani, Kentaro Yamawaki, Tsuneyoshi Tominaga, Masatake Tanaka
  • Patent number: 11003105
    Abstract: A toner including a toner particle containing a binder resin and an external additive, wherein the external additive contains composite particles of an organosilicon polymer fine particle and a fatty acid metal salt.
    Type: Grant
    Filed: December 27, 2019
    Date of Patent: May 11, 2021
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Masamichi Sato, Shohei Kototani, Kentaro Yamawaki, Tsuneyoshi Tominaga, Masatake Tanaka, Taiji Katsura
  • Publication number: 20210116831
    Abstract: An electrophotographic apparatus including an electrophotographic photosensitive member, a charging unit, and a developing unit, wherein the charging unit includes a conductive member disposed to be contactable with the electrophotographic photosensitive member, a conductive layer of the conductive member has a matrix-domain structure, at least some of the domains are exposed at the outer surface of the conductive member, the volume resistivity RI of the matrix is greater than 1.00×1012 ?·cm and not greater than 1.00×1017 ?·cm, the matrix volume resistivity R1 is at least 1.0×105-times the domain volume resistivity R2, and the developing unit includes a toner, the toner includes a binder resin-containing toner particle and an external additive, and the external additive contains fine particles of a hydrotalcite compound.
    Type: Application
    Filed: October 15, 2020
    Publication date: April 22, 2021
    Inventors: Tsuneyoshi Tominaga, Shohei Tsuda, Shohei Kototani, Noriyoshi Umeda, Masahiro Kurachi, Kazuhiro Yamauchi, Motonari Ito
  • Publication number: 20210116832
    Abstract: An electrophotographic apparatus comprising an electrophotographic photosensitive member, a charging unit, and a developing unit, wherein the charging unit has a conductive member contactable with the electrophotographic photosensitive member, and a conductive layer of the conductive member has a matrix-domain structure; at least some of the domains are exposed at the outer surface; a volume resistivity R1 of the matrix and a volume resistivity R2 of the domains satisfy specific relationship; Martens hardness G1 of the matrix and Martens hardness G2 of the domains satisfy relationship G1<G2; the surface roughness Ra of the conductive member is not more than 2.00 ?m; the toner has an external additive having a shape factor SF-1 of not more than 115; and A<Dms is satisfied where A is the number-average diameter of the external additive and Dms is a distance between adjacent walls between the domains.
    Type: Application
    Filed: October 15, 2020
    Publication date: April 22, 2021
    Inventors: Shohei Kototani, Noriyoshi Umeda, Tsuneyoshi Tominaga, Shohei Tsuda, Noboru Miyagawa, Kazuhiro Yamauchi
  • Publication number: 20210116828
    Abstract: An electrophotographic apparatus comprising an electrophotographic photosensitive member, a charging device, and a developing device, wherein the charging device comprises a conductive member arranged to be capable of contacting the electrophotographic photosensitive member, a conductive layer on the conductive member outer surface comprises a matrix and a plurality of domains dispersed in the matrix, at least some of the domains are exposed at the conductive member outer surface, the matrix has a volume resistivity of larger than 1.00×1012 ?·cm and is 1.0×105 times or more one of the domains, the developing device comprises the toner comprising a toner particle, fine particles A and B, the fine particle A has a volume resistivity of 1.0×103 to 1.0×1010 ?·cm, and the fine particle B is silica fine particle and having a volume resistivity of 1.0×1011 to 1.0×1017 ?·cm.
    Type: Application
    Filed: October 15, 2020
    Publication date: April 22, 2021
    Inventors: Noriyoshi Umeda, Tsuneyoshi Tominaga, Shohei Tsuda, Shohei Kototani, Masahiro Kurachi, Kazuhiro Yamauchi, Hideo Kihara
  • Patent number: 10976679
    Abstract: A toner containing: a toner particle that contains a binder resin and an external additive, wherein the external additive contains an organosilicon polymer fine particle, the binder resin contains an amorphous resin and a crystalline polyester resin, a content of the crystalline polyester resin in the binder resin is from 5 to 30 mass %, and the crystalline polyester resin contains from 5 to 25 mass % of a component having a molecular weight of not more than 2,500.
    Type: Grant
    Filed: December 27, 2019
    Date of Patent: April 13, 2021
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Masatake Tanaka, Taiji Katsura, Masamichi Sato, Shohei Kototani, Kentaro Yamawaki, Tsuneyoshi Tominaga
  • Patent number: 10976678
    Abstract: Provided is a toner including a toner particle containing a binder resin, and an external additive, wherein the external additive contains an external additive A and an external additive B, the external additive A is an organosilicon polymer fine particle, the number-average particle diameter of primary particles of the organosilicon polymer fine particle is from 30 to 300 nm, the external additive B is a silica fine particle, the number-average particle diameter of primary particles of the silica fine particle is from 100 to 300 nm, the fixing rate of the external additive A to the toner particle according to a water washing method is less than 30%, and the fixing rate of the external additive B to the toner particle according to the washing method is at least 30%.
    Type: Grant
    Filed: December 27, 2019
    Date of Patent: April 13, 2021
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Kentaro Yamawaki, Shohei Kototani, Noriyoshi Umeda, Tomonori Matsunaga, Shohei Tsuda, Satoshi Otsuji
  • Patent number: 10942466
    Abstract: A toner including a toner particle containing a binder resin and an external additive, wherein the toner particle contains a polyvalent metal compound, the polyvalent metal compound is at least one selected from the group consisting of aluminum compounds, iron compounds and magnesium compounds, a content of a metal element derived from the polyvalent metal compound in the toner particle is from 0.080 to 20.000 ?mol/g, the external additive contains an organosilicon polymer particle having a hydroxyl group, a ratio of a number-average particle diameter of the organosilicon polymer particle to a number-average particle diameter of the toner particle is from 0.0160 to 0.0650, and a content of the organosilicon polymer particle is at least 0.10 mass parts per 100.00 mass parts of the toner particle.
    Type: Grant
    Filed: December 27, 2019
    Date of Patent: March 9, 2021
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Tsuneyoshi Tominaga, Masatake Tanaka, Taiji Katsura, Masamichi Sato, Shohei Kototani, Kentaro Yamawaki
  • Patent number: 10942465
    Abstract: A toner comprising a toner particle that contains a binder resin and a wax; in a microcompression test under a maximum load condition of 1.1×10?3 N, a force applied to the toner particle when a percentage deformation of the toner particle with reference to a number-average particle diameter of the toner particle at 25° C. reaches 15% is 0.10 to 1.00 mN and the force applied to the toner particle when the percentage deformation at 45° C. reaches 15% is 0.10 to 0.40 mN; and when the force applied to the toner particle is a variable and the percentage deformation of the toner particle is from 15 to 30%, the rate of increase in the percentage deformation of the toner particle at 25° C. and the rate of increase in the percentage deformation of the toner particle at 45° C. satisfy specific formula.
    Type: Grant
    Filed: October 14, 2019
    Date of Patent: March 9, 2021
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Shohei Kototani, Kentaro Yamawaki, Koji Abe, Tomonori Matsunaga, Masamichi Sato