Patents by Inventor Shohei Tsuda

Shohei Tsuda 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
  • 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: 20230047510
    Abstract: A toner comprising: a toner particle comprising a binder resin and boric acid; and an external additive A having a primary particle major diameter of 80 to 200 nm, wherein in ATR-IR analysis of the toner particle in an ATR method using germanium as an ATR crystal, a peak corresponding to boric acid is detected, the average value of a shape factor SF-1 of the external additive A is 105 to 250, and the average value of a shape factor SF-2 of the external additive A is 102 to 250.
    Type: Application
    Filed: July 21, 2022
    Publication date: February 16, 2023
    Inventors: Shohei Tsuda, Taiji Katsura, Shintaro Kawaguchi
  • Publication number: 20230042289
    Abstract: A toner comprising a toner particle comprising a binder resin and boric acid, wherein the toner has an average circularity of 0.95 or more, and the toner has a shape factor SF1 of 105 to 125, and a method for producing to provide a toner with excellent durability for which the improvement of transfer rate with the above physical characteristics.
    Type: Application
    Filed: July 21, 2022
    Publication date: February 9, 2023
    Inventors: Masatake Tanaka, Shohei Tsuda, Tatsuya Saeki
  • 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
  • Publication number: 20220291601
    Abstract: A toner comprising a toner particle comprising a binder resin, a crystalline material A, and a crystalline material B, wherein the binder resin contains a resin M in an amount of 70 mass % or more relative to the binder resin, the crystalline material A has a melting point of 50.0° C. to 100.0° C., and when, the difference between the SP value of the resin M and material A is designated as ?SPAM, the difference between the SP value of the resin M and crystalline material B is designated as ?SPBM, the difference between the SP value of the crystalline material A and crystalline material B is designated as ?SPAB, the peak molecular weight of the crystalline material A and crystalline material B is designated as MpA and MpB each, the formulae (1) to (3) are satisfied: 50?MpB×?SPBM2?MpA×?SPAM2?450??(1) MpA×?SPAM2?800??(2) ?SPAB?0.
    Type: Application
    Filed: March 4, 2022
    Publication date: September 15, 2022
    Inventors: Taiji Katsura, Shohei Tsuda, Tatsuya Saeki
  • 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
  • Patent number: 11249408
    Abstract: A toner including a toner particle including a binder resin, wherein fine particles A and B are present on a surface of the toner particle; the fine particles A are a fatty acid metal salt; the fine particles B have a specific volume resistivity; an average theoretical surface area of the toner particle, an amount of the fine particles A, and a coverage ratio of the toner particle surface by the fine particles A satisfy a specific relationship; the amount of the fine particles B is in a specific range; and a proportion F of an area occupied by a part of the fine particles B embedded in a surface vicinity region of the toner in a total area occupied by the fine particles B present in a cross section of one particle of the toner is 50% by area or more.
    Type: Grant
    Filed: June 25, 2020
    Date of Patent: February 15, 2022
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Shohei Tsuda, Tsuneyoshi Tominaga, Masatake Tanaka, Taiji Katsura, Masamichi Sato
  • Patent number: 11112712
    Abstract: A toner comprising: a toner particle that contains a release agent-containing toner base particle, and an organosilicon polymer on a toner base particle surface, and an external additive A, the organosilicon polymer has a T3 unit structure; the organosilicon polymer forms protruded portions on the toner base particle surface; the number-average value of the protrusion height H is from 30 nm to 300 nm; the ratio of the number-average primary particle diameter R of the external additive A to the number-average value of the protrusion height H is from 1.00 to 4.00; the number-average primary particle diameter R of the external additive A is from 30 nm to 1,200 nm; and, in an image obtained by observing the toner surface with SEM, the area percentage for the bright region area in the image with reference to the total area of the image is from 30.0% to 75.0%.
    Type: Grant
    Filed: March 11, 2020
    Date of Patent: September 7, 2021
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Tomonori Matsunaga, Hidekazu Fumita, Noriyoshi Umeda, Shohei Tsuda
  • Patent number: 11112708
    Abstract: A toner comprising a toner particle including a binder resin and a colorant and an external additive, wherein the external additive contains an external additive A having a Feret diameter of 60 to 200 nm, the external additive A is inorganic fine particles or organic-inorganic composite fine particles, adhesion index of the external additive A to the toner is 0.00 to 3.00, and penetration depth b and protrusion height c satisfy Relational expressions (1) and (2) below, where b (nm) denotes penetration depth of the external additive A, at a portion of the external additive A penetrating into the toner particle interior from the surface thereof, and c (nm) denotes a protrusion height of the external additive A at that portion, in an observation of an image resulting from image processing of a cross section of the toner using TEM; 60?b+c?200??(1), 0.15?b/(b+c)?0.30??(2).
    Type: Grant
    Filed: January 30, 2020
    Date of Patent: September 7, 2021
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Kozue Uratani, Daisuke Yoshiba, Shohei Tsuda, Tomoya Nagaoka, Mariko Yamashita, Kazuki Kaneko, Ryo Nagata
  • 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
  • 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: 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
  • 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
  • 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
  • Publication number: 20210003932
    Abstract: A toner including a toner particle including a binder resin, wherein fine particles A and B are present on a surface of the toner particle; the fine particles A are a fatty acid metal salt; the fine particles B have a specific volume resistivity; an average theoretical surface area of the toner particle, an amount of the fine particles A, and a coverage ratio of the toner particle surface by the fine particles A satisfy a specific relationship; the amount of the fine particles B is in a specific range; and a proportion F of an area occupied by a part of the fine particles B embedded in a surface vicinity region of the toner in a total area occupied by the fine particles B present in a cross section of one particle of the toner is 50% by area or more.
    Type: Application
    Filed: June 25, 2020
    Publication date: January 7, 2021
    Inventors: Shohei Tsuda, Tsuneyoshi Tominaga, Masatake Tanaka, Taiji Katsura, Masamichi Sato
  • Patent number: 10782623
    Abstract: A toner comprising: a toner particle that contains a binder resin and a colorant: and an external additive, wherein (1) the average circularity of the toner is at least 0.960; (2) the fixing ratio of the external additive on the toner particle is from 75% to 100%; and (3) in a differential curve obtained by the differentiation, by load, of a load-displacement curve where the horizontal axis is load (mN) and the vertical axis is displacement (?m), the load-displacement curve being provided by measurement of the strength of the toner by a nanoindentation procedure, a load A that provides a maximum value in the differential curve in a load region from 0.20 mN to 2.30 mN is from 1.15 mN to 1.50 mN.
    Type: Grant
    Filed: July 27, 2018
    Date of Patent: September 22, 2020
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Daisuke Yoshiba, Shohei Tsuda, Mariko Yamashita, Kozue Uratani, Ryo Nagata