Patents by Inventor Akinori Saitoh

Akinori Saitoh 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: 20230014605
    Abstract: A toner includes toner base particles and external additives deposited on a surface of the toner base particle. The toner base particle includes an amorphous polyester resin, a crystalline polyester resin, a release agent, and resin particles. An abundance ratio of the crystalline polyester resin in the surface of the toner base particle as observed by TEM is 2.5% or greater but 25% or less. The resin particles are deposited at the surface of the toner base particle as observed by SEM. A ratio of aggregates of the resin particles occupying the surface of the toner base particle is 1% or greater but 70% or less, where R is a major axis of the minimum particle of the resin particles, and the resin particle having a major axis of 3R or greater is determined as the aggregate.
    Type: Application
    Filed: July 6, 2022
    Publication date: January 19, 2023
    Applicant: Ricoh Company, Ltd.
    Inventors: Akinori SAITOH, Akio Takei, Toma Takebayashi, Masahiro Yukikawa, Tomomi Harashima, Hiroshi Yamada
  • Publication number: 20220050395
    Abstract: A toner includes toner particles, each including: a toner base particle including a binder resin, a colorant, and wax; and resin particles on a surface of the toner base particle, wherein Formulae 1 to 3 below are satisfied, where M is a volume average primary particle diameter (nm) of the resin particles, and L is a distance (nm) between the resin particles present next to one another on the surface of the toner base particle: M<L;??(Formula 1) 5 (nm)<M?60 (nm); and??(Formula 2) 0.40?[M (nm)/L (nm)]<0.90.
    Type: Application
    Filed: August 12, 2021
    Publication date: February 17, 2022
    Applicant: Ricoh Company, Ltd.
    Inventors: Hiroshi YAMADA, Akinori Saitoh, Akio Takei, Yasuo Kamada, Toma Takebayashi
  • Publication number: 20210356877
    Abstract: A toner includes toner base particles each including: a binder resin, a colorant, and wax; and resin particles on surfaces of the toner base particles. A standard deviation of a distance between the resin particles next to each other on the surfaces of the toner base particles is less than 500 nm.
    Type: Application
    Filed: May 12, 2021
    Publication date: November 18, 2021
    Inventors: Yasuo KAMADA, Hiroshi YAMADA, Akinori SAITOH, Akio TAKEI, Toma TAKEBAYASHI, Masahiro YUKIKAWA
  • Patent number: 10073366
    Abstract: A toner is provided. The toner includes an amorphous resin, a crystalline resin dispersed in the amorphous resin, and a release agent. The toner satisfies the following inequality: B/A<0.8 where A represents a perimeter of the crystalline resin and B represents a length of a part of the perimeter A of the crystalline resin at which the crystalline resin is in contact with the amorphous resin, A and B being measured from a cross-sectional image of the toner observed with transmission electron microscope.
    Type: Grant
    Filed: June 14, 2017
    Date of Patent: September 11, 2018
    Assignee: Ricoh Company, Ltd.
    Inventors: Kohsuke Nagata, Ryuuta Yoshida, Shinya Nakayama, Tsuyoshi Sugimoto, Akinori Saitoh, Hideyuki Santo, Suzuka Karato, Koh Ohnuma, Takahiro Kadota, Shinsuke Nagai, Akihiro Takeyama
  • Patent number: 9880479
    Abstract: Toner that includes a polyester resin, fluorine and aluminum. The toner satisfies formulae (1) and (2), 1.00?AB/B?0.50??(1) 0?(A?AB)/A?0.25??(2) where A represents an area where the fluorine exists measured by Energy Dispersive X-ray Spectroscopy (EDS), B represents an area where the aluminum exists measured by Energy Dispersive X-ray Spectroscopy (EDS) and AB represents an overlapping area between A and B. Toner stored unit, image forming apparatus, and image forming method.
    Type: Grant
    Filed: January 12, 2017
    Date of Patent: January 30, 2018
    Assignee: RICOH COMPANY, LTD.
    Inventors: Hideyuki Santoh, Tsuyoshi Sugimoto, Akinori Saitoh, Shin Hasegawa, Suzuka Amemori, Kohsuke Nagata, Koh Ohnuma
  • Publication number: 20170363980
    Abstract: A toner is provided. The toner includes an amorphous resin, a crystalline resin dispersed in the amorphous resin, and a release agent. The toner satisfies the following inequality: B/A<0.8 where A represents a perimeter of the crystalline resin and B represents a length of a part of the perimeter A of the crystalline resin at which the crystalline resin is in contact with the amorphous resin, A and B being measured from a cross-sectional image of the toner observed with transmission electron microscope.
    Type: Application
    Filed: June 14, 2017
    Publication date: December 21, 2017
    Inventors: Kohsuke NAGATA, Ryuuta YOSHIDA, Shinya NAKAYAMA, Tsuyoshi SUGIMOTO, Akinori SAITOH, Hideyuki SANTO, Suzuka KARATO, Koh OHNUMA, Takahiro KADOTA, Shinsuke NAGAI, Akihiro TAKEYAMA
  • Publication number: 20170199476
    Abstract: Toner that includes a polyester resin, fluorine and aluminum. The toner satisfies formulae (1) and (2), 1.00?AB/B?0.50 ??(1) 0?(A?AB)/A?0.25 ??(2) where A represents an area where the fluorine exists measured by Energy Dispersive X-ray Spectroscopy (EDS), B represents an area where the aluminum exists measured by Energy Dispersive X-ray Spectroscopy (EDS) and AB represents an overlapping area between A and B. Toner stored unit, image forming apparatus, and image forming method.
    Type: Application
    Filed: January 12, 2017
    Publication date: July 13, 2017
    Inventors: Hideyuki SANTOH, Tsuyoshi SUGIMOTO, Akinori SAITOH, Shin HASEGAWA, Suzuka AMEMORI, Kohsuke NAGATA, Koh OHNUMA
  • Patent number: 9588451
    Abstract: A toner, wherein an amount of Al detected in the toner is 0.7% to 1.3%, where the amount of Al detected is determined based on quantitative analysis of Al by X-ray photoelectron spectroscopic analysis (XPS), and wherein [Tg2nd (THF insoluble matter)] is ?40° C. to 30° C., where the [Tg2nd (THF insoluble matter)] is a glass transition temperature measured in second heating of differential scanning calorimetry (DSC) of THF insoluble matter of the toner.
    Type: Grant
    Filed: April 27, 2015
    Date of Patent: March 7, 2017
    Assignee: Ricoh Company, Ltd.
    Inventors: Akihiro Takeyama, Shinya Nakayama, Akinori Saitoh, Shinsuke Nagai, Hiroyuki Takeda
  • Patent number: 9557671
    Abstract: A toner, including: base particles containing a polyester resin, a colorant, and a release agent, wherein the toner has a glass transition temperature (Tg1st) of 20° C. to 50° C. where the glass transition temperature (Tg1st) is measured in first heating of differential scanning calorimetry (DSC) of the toner, wherein tetrahydrofuran (THF) insoluble matter of the toner has a glass transition temperature [Tg2nd (THF insoluble matter)] of 30° C. or lower where the glass transition temperature [Tg2nd (THF insoluble to matter)] is measured in second heating of differential scanning calorimetry (DSC) of the THF insoluble matter, and wherein 50% or less of the colorant is present within a region of 1,000 nm from a surface of each of the base particles toward a center thereof.
    Type: Grant
    Filed: February 24, 2015
    Date of Patent: January 31, 2017
    Assignee: Ricoh Company, Ltd.
    Inventors: Ryuta Chiba, Shinya Nakayama, Hiroshi Yamada, Minoru Masuda, Akinori Saitoh, Hideyuki Santo, Shinsuke Nagai, Akihiro Takeyama, Hiroyuki Takeda, Tsuyoshi Sugimoto, Suzuka Amemori, Kohsuke Nagata
  • Publication number: 20160187795
    Abstract: Provided is a toner including at least a polyester resin, wherein the polyester resin has a urethane bond and a urea bond, wherein a ratio (B)/(A) between a nitrogen content (A) in a compound that is contained in a pyrolysate of the toner produced when the toner is pyrolyzed from 50° C. to 700° C. and has two isocyanate groups and a nitrogen content (B) in a compound that is contained in the pyrolysate and has one isocyanate group and one amino group satisfies 0.6?(B)/(A)?1.3, and wherein a nitrogen content in the surface of the toner is from 0 atom % to 0.9 atom %.
    Type: Application
    Filed: December 27, 2015
    Publication date: June 30, 2016
    Inventors: Akinori SAITOH, Tsuyoshi SUGIMOTO, Shinsuke NAGAI, Hiroyuki TAKEDA, Takahiro KADOTA, Akihiro TAKEYAMA
  • Publication number: 20150323878
    Abstract: A toner, wherein an amount of Al detected in the toner is 0.7% to 1.3%, where the amount of Al detected is determined based on quantitative analysis of Al by X-ray photoelectron spectroscopic analysis (XPS), and wherein [Tg2nd (THF insoluble matter)] is ?40° C. to 30° C., where the [Tg2nd (THF insoluble matter)] is a glass transition temperature measured in second heating of differential scanning calorimetry (DSC) of THF insoluble matter of the toner.
    Type: Application
    Filed: April 27, 2015
    Publication date: November 12, 2015
    Inventors: Akihiro TAKEYAMA, Shinya NAKAYAMA, Akinori SAITOH, Shinsuke NAGAI, Hiroyuki TAKEDA
  • Publication number: 20150248070
    Abstract: A toner, including: base particles containing a polyester resin, a colorant, and a release agent, wherein the toner has a glass transition temperature (Tg1st) of 20° C. to 50° C. where the glass transition temperature (Tg1st) is measured in first heating of differential scanning calorimetry (DSC) of the toner, wherein tetrahydrofuran (THF) insoluble matter of the toner has a glass transition temperature [Tg2nd (THF insoluble matter)] of 30° C. or lower where the glass transition temperature [Tg2nd (THF insoluble to matter)] is measured in second heating of differential scanning calorimetry (DSC) of the THF insoluble matter, and wherein 50% or less of the colorant is present within a region of 1,000 nm from a surface of each of the base particles toward a center thereof.
    Type: Application
    Filed: February 24, 2015
    Publication date: September 3, 2015
    Inventors: Ryuta CHIBA, Shinya Nakayama, Hiroshi Yamada, Minoru Masuda, Akinori Saitoh, Hideyuki Santo, Shinsuke Nagai, Akihiro Takeyama, Hiroyuki Takeda, Tsuyoshi Sugimoto, Suzuka Amemori, Kohsuke Nagata
  • Patent number: 8492063
    Abstract: A method of manufacturing a toner including forming a wax liquid dispersion in which a wax is dispersed in an organic solvent (A1), mixing an organic layer including the wax liquid dispersion, a binder resin and an organic solvent (A) to form an oil phase and dispersing and emulsifying the oil phase in an aqueous medium to obtain an emulsified liquid dispersion, wherein the aspect ratio average of the wax in the wax liquid dispersion is from 0.3 to 0.7 and the toner includes toner particles satisfying the following relationship (1) in an amount of 20% by number or smaller based on all toner particles: 0.5<D2/D1, relationship (1), where D1 represents the major diameter (D1) of the toner and D2 represents the major diameter of the wax.
    Type: Grant
    Filed: November 28, 2008
    Date of Patent: July 23, 2013
    Assignee: Ricoh Company, Limited
    Inventors: Junichi Awamura, Akinori Saitoh, Masahide Yamada, Osamu Uchinokura, Tomomi Suzuki
  • Patent number: 8192911
    Abstract: A method of manufacturing a toner including dispersing a binder resin, a coloring agent and a releasing agent in an organic solvent to obtain an oil phase; dispersing the oil phase in an aqueous medium with a shearing force to obtain a dispersion emulsion; wherein the shearing force is made by a screen or vessel that is situated around a rotor, the screen spinning in a direction opposite to the direction that the rotor spins. Toner produced. Method of using the toner.
    Type: Grant
    Filed: May 8, 2009
    Date of Patent: June 5, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Junichi Awamura, Akinori Saitoh, Osamu Uchinokura, Masahide Yamada, Tomomi Suzuki
  • Patent number: 8187785
    Abstract: A method of manufacturing the toner comprising dispersing at least one of a binder resin or a precursor thereof, a coloring agent and a releasing agent in an organic solvent to obtain an oil phase, dispersing the oil phase in an aqueous medium with a shearing force to obtain a dispersion emulsion, wherein the dispersion emulsion process has plural stages and the shear speed A of the emulsification process of stage n is faster than the shear speed B of the emulsification process of stage n+1.
    Type: Grant
    Filed: April 23, 2009
    Date of Patent: May 29, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Junichi Awamura, Akinori Saitoh, Osamu Uchinokura, Tomomi Suzuki
  • Patent number: 8178276
    Abstract: A method of manufacturing a toner including granulating mother toner particles in an aqueous medium to obtain a slurry containing the mother toner particles and adjusting a size distribution of the mother toner particles by screening coarse mother toner particles from the slurry with a screen to obtain the toner containing mother toner particulates.
    Type: Grant
    Filed: March 6, 2009
    Date of Patent: May 15, 2012
    Assignee: Ricoh Company Limited
    Inventors: Osamu Uchinokura, Akinori Saitoh, Junichi Awamura, Masahide Yamada, Hiroshi Yamada
  • Patent number: 8137883
    Abstract: A toner is provided including a binder resin and a wax having primarily C—H and C—C bonds, and having a melting point of 50 to 90° C., wherein the wax is present in a surface portion of the toner in an amount of from 0.1 to 4.0% by weight, wherein the amount of the wax is determined by Fourier transform infrared spectroscopy attenuated total reflectance (FTIR-ATR); and the use of the toner in an image forming method, image forming apparatus, developer and toner cartridge containing the toner.
    Type: Grant
    Filed: May 20, 2011
    Date of Patent: March 20, 2012
    Assignee: Ricoh Company Limited
    Inventors: Ryota Inoue, Shigeru Emoto, Naohiro Watanabe, Masahide Yamada, Akinori Saitoh, Masahiro Ohki, Tsunemi Sugiyama, Shinichi Wakamatsu, Takayuki Yoshii, Eiji Sawamura
  • Patent number: 8124308
    Abstract: Toner and a developer which are excellent in cleaning property and fixing property at low temperature, and capable of forming images with high quality are provided, along with a method for their production. A toner producing method involves dispersing and/or emulsifying an oil phase or a monomer phase containing a toner composition and/or a toner composition precursor in a water-based medium to granulate, wherein the toner has an average circularity of 0.925 to 0.970, and the toner composition and/or the toner composition precursor has a layered inorganic material in which at least a part of interlayer ions in the layered inorganic material has been exchanged with organic ions.
    Type: Grant
    Filed: December 13, 2010
    Date of Patent: February 28, 2012
    Assignee: Ricoh Company. Ltd.
    Inventors: Naohiro Watanabe, Shigeru Emoto, Yohichiroh Watanabe, Masahide Yamada, Tsunemi Sugiyama, Masahiro Ohki, Akinori Saitoh, Ryota Inoue, Osamu Uchinokura, Junichi Awamura
  • Patent number: 8034524
    Abstract: A toner satisfying at least one of the following relationships: 10° C.<(T1?T2)<60° C. and 0<Q2/Q1<? wherein T1 represents a glass transition temperature of the toner and Q1 represents an endothermic quantity at a melting point thereof before melting when heated from ?20° C. to 150° C. at a heating speed of 10° C./min, and T2 represents a glass transition temperature thereof and Q2 represents a an endothermic quantity at a melting point thereof after melting after heated from ?20° C. to 150° C. at a heating speed of 10° C./min, cooled to ?20° C. at a cooling speed of 10° C./min and heated again at a heating speed of 10° C./min.
    Type: Grant
    Filed: January 29, 2010
    Date of Patent: October 11, 2011
    Assignee: Ricoh Company, Ltd.
    Inventors: Ryota Inoue, Sonoh Matsuoka, Chiaki Tanaka, Naohiro Watanabe, Masahide Yamada, Masahiro Ohki, Akinori Saitoh
  • Patent number: 8026031
    Abstract: Toner and a developer which are excellent in cleaning property and fixing property at low temperature, and capable of forming images with high quality are provided. A toner prepared by dispersing and/or emulsifying an oil phase or a monomer phase comprising a toner composition and/or a toner composition precursor in a water-based medium to granulate, wherein the toner has an average circularity of 0.925 to 0.970, and the toner composition and/or the toner composition precursor has a layered inorganic material in which at least a part of interlayer ions in the layered inorganic material has been exchanged with organic ions.
    Type: Grant
    Filed: March 5, 2007
    Date of Patent: September 27, 2011
    Assignee: Ricoh Company, Ltd.
    Inventors: Naohiro Watanabe, Shigeru Emoto, Yohichiroh Watanabe, Masahide Yamada, Tsunemi Sugiyama, Masahiro Ohki, Akinori Saitoh, Ryota Inoue, Osamu Uchinokura, Junichi Awamura