Patents by Inventor Yuji Natori

Yuji Natori 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: 20150152275
    Abstract: A method for preparing a pigment dispersion including subjecting a mixture including at least a pigment, a dispersant and water to a first dispersion treatment using a media mill to prepare a first dispersion; and then subjecting the first dispersion to a second dispersion treatment using a media-less mill to prepare the pigment dispersion, wherein the pigment in the pigment dispersion has an average particle diameter (D50) of from 20 to 130 nm for pigments except carbon black or from 70 to 180 for carbon black, and the standard deviation of the particle diameter of the pigment is less than the average particle diameter (D50) for pigments except carbon black or one half of the average particle diameter (D50) for carbon black. A pigment dispersion prepared by the method. An inkjet ink including the pigment dispersion and one member selected from water, water soluble organic solvents, and surfactants.
    Type: Application
    Filed: February 11, 2015
    Publication date: June 4, 2015
    Inventors: Minoru HAKIRI, Keishi TANIGUCHI, Shin HASEGAWA, Yuji NATORI, Yasuyuki HOSOGI, Shigeo HATADA
  • Patent number: 8523992
    Abstract: The present invention provides a magenta recording ink composition including at least a solid solution pigment (A) containing quinacridone, a lake pigment (B) having a xanthene structure, an aqueous solvent, and water, wherein the solid solution pigment (A) has visible light absorption peaks at wavelength ranges of from 510 nm to 530 nm and from 540 nm to 560 nm, and a mass ratio (B/A) of the lake pigment (B) to the solid solution pigment (A) falls within the range of 0.1 to 5.
    Type: Grant
    Filed: January 20, 2009
    Date of Patent: September 3, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Akihiko Matsuyama, Yuji Natori
  • Patent number: 8246156
    Abstract: The object of the present invention is to provide a water-based pigment dispersion containing a pigment, a dispersing agent, a resin emulsion, and water, the water-based pigment dispersion is subjected to a heat treatment. The present invention also provides a water-based pigment ink containing the water-based pigment dispersion, a dispersing agent, a resin emulsion, and water.
    Type: Grant
    Filed: August 12, 2010
    Date of Patent: August 21, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Shin Hasegawa, Keishi Taniguchi, Minoru Hakiri, Yasuyuki Hosogi, Yuji Natori, Shigeo Hatada
  • Publication number: 20100302306
    Abstract: The object of the present invention is to provide a water-based pigment dispersion containing a pigment, a dispersing agent, a resin emulsion, and water, the water-based pigment dispersion is subjected to a heat treatment. The present invention also provides a water-based pigment ink containing the water-based pigment dispersion, a dispersing agent, a resin emulsion, and water.
    Type: Application
    Filed: August 12, 2010
    Publication date: December 2, 2010
    Inventors: Shin HASEGAWA, Keishi Taniguchi, Minoru Hakiri, Yasuyuki Hosogi, Yuji Natori, Shigeo Hatada
  • Publication number: 20100285287
    Abstract: The present invention provides a magenta recording ink composition including at least a solid solution pigment (A) containing quinacridone, a lake pigment (B) having a xanthene structure, an aqueous solvent, and water, wherein the solid solution pigment (A) has visible light absorption peaks at wavelength ranges of from 510 nm to 530 nm and from 540 nm to 560 nm, and a mass ratio (B/A) of the lake pigment (B) to the solid solution pigment (A) falls within the range of 0.1 to 5.
    Type: Application
    Filed: January 20, 2009
    Publication date: November 11, 2010
    Inventors: Akihiko Matsuyama, Yuji Natori
  • Patent number: 7815301
    Abstract: The object of the present invention is to provide a water-based pigment dispersion containing a pigment, a dispersing agent, a resin emulsion, and water, the water-based pigment dispersion is subjected to a heat treatment. The present invention also provides a water-based pigment ink containing the water-based pigment dispersion, a dispersing agent, a resin emulsion, and water.
    Type: Grant
    Filed: March 15, 2006
    Date of Patent: October 19, 2010
    Assignee: Ricoh Company, Ltd.
    Inventors: Shin Hasegawa, Keishi Taniguchi, Minoru Hakiri, Yasuyuki Hosogi, Yuji Natori, Shigeo Hatada
  • Patent number: 7798629
    Abstract: The present invention provides a pigment dispersion that contains a carbon black, a dispersing agent and water, wherein the carbon black is any one of a channel black and a gas black, the dispersing agent is a sodium naphthalenesulfonate formalin condensate, and the total content of a dimer, a trimer and a tetramer of naphthalenesulfonate in the sodium naphthalenesulfonate formalin condensate is 20% by weight to 80% by weight. The present invention also provides an inkjet ink using the pigment dispersion.
    Type: Grant
    Filed: August 10, 2007
    Date of Patent: September 21, 2010
    Assignee: Ricoh Company, Ltd.
    Inventors: Minoru Hakiri, Keishi Taniguchi, Yuji Natori, Yasuyuki Hosogi, Shigeo Hatada, Shin Hasegawa
  • Publication number: 20080036830
    Abstract: An ink-jet ink including a pigment a dispersant, a water, a particulate resin (A) dyed with a fluorescent dye and having an average particle diameter of from 50 to 200 nm, and an emulsion of a self-emulsifiable polyurethane; and a method for preparing the ink-jet ink, an ink cartridge containing the ink-jet ink, an image forming method using the ink-jet ink, and an image formed with the ink-jet ink.
    Type: Application
    Filed: August 6, 2007
    Publication date: February 14, 2008
    Inventors: Yuji NATORI, Keishi TANIGUCHI, Minoru HAKIRI, Yasuyuki HOSOGI, Shigeo HATADA, Shinn HASEGAWA
  • Publication number: 20080036840
    Abstract: The present invention provides a pigment dispersion that contains a carbon black, a dispersing agent and water, wherein the carbon black is any one of a channel black and a gas black, the dispersing agent is a sodium naphthalenesulfonate formalin condensate, and the total content of a dimer, a trimer and a tetramer of naphthalenesulfonate in the sodium naphthalenesulfonate formalin condensate is 20% by weight to 80% by weight. The present invention also provides an inkjet ink using the pigment dispersion.
    Type: Application
    Filed: August 10, 2007
    Publication date: February 14, 2008
    Inventors: Minoru Hakiri, Keishi Taniguchi, Yuji Natori, Yasuyuki Hosogi, Shigeo Hatada, Shin Hasegawa
  • Patent number: 7250240
    Abstract: The toner according to the present invention may be produced from a toner raw composition which comprises a foaming agent, a binder resin and a colorant, wherein the colorant comprises a black metal compound, the foaming agent has a volume-average particle diameter of 2 ?m to 50 ?m, the toner raw composition turns into a porous mixture while the foaming agent expands at melting and kneading the toner raw composition, and the toner obtained through milling and classifying the porous mixture has a specific density of 1.0 g/cm3 to 1.3 g/cm3, wherein the specific density is determined as follows: 1 gram of toner is pressed at 400 kgf/cm2 for five minutes in a discal cavity having a diameter of 20 mm, then the discal toner is removed; the discal toner volume (V) is calculated from the diameter and height, measured at 10 minutes after releasing the pressure on the discal toner, and the discal toner mass (W) is measured; then the specific density is determined from the following formula: Specific Density (?T)=W/V.
    Type: Grant
    Filed: June 9, 2004
    Date of Patent: July 31, 2007
    Assignee: Ricoh Company, Ltd.
    Inventors: Hachiroh Tosaka, Tomiaki Ito, Yuji Natori
  • Patent number: 7201938
    Abstract: A thermosensitive stencil paper having a thermoplastic resin film and a porous resin layer which is provided on the thermoplastic resin film by coating a porous resin layer formation coating liquid including a water-in-oil emulsion of a resin on the thermoplastic resin film and drying the coating liquid. In addition, the method of producing the above-mentioned thermosensitive stencil paper is also disclosed.
    Type: Grant
    Filed: January 30, 2002
    Date of Patent: April 10, 2007
    Assignees: Ricoh Company, Ltd., Tohoku Ricoh Co., Ltd.
    Inventors: Fumiaki Arai, Takehiko Iwaoka, Yuji Natori, Masanori Rimoto
  • Publication number: 20060272543
    Abstract: A method for preparing a pigment dispersion including subjecting a mixture including at least a pigment, a dispersant and water to a first dispersion treatment using a media mill to prepare a first dispersion; and then subjecting the first dispersion to a second dispersion treatment using a media-less mill to prepare the pigment dispersion, wherein the pigment in the pigment dispersion has an average particle diameter (D50) of from 20 to 130 nm for pigments except carbon black or from 70 to 180 for carbon black, and the standard deviation of the particle diameter of the pigment is less than the average particle diameter (D50) for pigments except carbon black or one half of the average particle diameter (D50) for carbon black. A pigment dispersion prepared by the method. An inkjet ink including the pigment dispersion and one member selected from water, water soluble organic solvents, and surfactants.
    Type: Application
    Filed: June 1, 2006
    Publication date: December 7, 2006
    Inventors: Minoru Hakiri, Keishi Taniguchi, Shin Hasegawa, Yuji Natori, Yasuyuki Hosogi, Shigeo Hatada
  • Patent number: 7142800
    Abstract: Disclosed is an intermediate transferring belt utilized in order to transfer a toner image formed by developing a latent image on an image bearing member by means of a toner, wherein the intermediate transferring belt comprises a matrix and conductive fine particles, the conductive fine particles are dispersed into the matrix, and the surface resistivity ?s of the outer surface of the intermediate transferring belt is 1.0×109 ohm/square to 1.0×1013 ohm/square, and wherein the intermediate transferring belt is applied to an image forming apparatus of which transferring electric field is controlled to 15 MV/m or less when the toner image on the image bearing member is primarily transferred to the intermediate transferring belt.
    Type: Grant
    Filed: October 14, 2004
    Date of Patent: November 28, 2006
    Assignee: Ricoh Company, Ltd.
    Inventors: Yuji Natori, Minoru Matsuo
  • Publication number: 20060209149
    Abstract: The object of the present invention is to provide a water-based pigment dispersion containing a pigment, a dispersing agent, a resin emulsion, and water, the water-based pigment dispersion is subjected to a heat treatment. The present invention also provides a water-based pigment ink containing the water-based pigment dispersion, a dispersing agent, a resin emulsion, and water.
    Type: Application
    Filed: March 15, 2006
    Publication date: September 21, 2006
    Inventors: Shin Hasegawa, Keishi Taniguchi, Minoru Hakiri, Yasuyuki Hosogi, Yuji Natori, Shigeo Hatada
  • Patent number: 7090955
    Abstract: A toner for developing an electrostatic latent image, including toner particles each containing a black colorant and a binder resin, wherein the black colorant comprises a metal oxide having a number average particle diameter in the range of 20 to 100 nm in an amount of 10 to 40% by weight based on a total weight of the toner particles.
    Type: Grant
    Filed: June 7, 2005
    Date of Patent: August 15, 2006
    Assignee: Ricoh Company, Ltd.
    Inventors: Hachiro Tosaka, Tomiaki Ito, Yuji Natori
  • Patent number: 6969574
    Abstract: A toner for developing an electrostatic latent image, including toner particles each containing a black colorant and a binder resin, wherein the black colorant comprises a metal oxide having a number average particle diameter in the range of 20 to 100 nm in an amount of 10 to 40% by weight based on a total weight of the toner particles.
    Type: Grant
    Filed: February 28, 2003
    Date of Patent: November 29, 2005
    Assignee: Ricoh Company, Ltd.
    Inventors: Hachiro Tosaka, Tomiaki Ito, Yuji Natori
  • Publication number: 20050238981
    Abstract: A toner for developing an electrostatic latent image, including toner particles each containing a black colorant and a binder resin, wherein the black colorant comprises a metal oxide having a number average particle diameter in the range of 20 to 100 nm in an amount of 10 to 40% by weight based on a total weight of the toner particles.
    Type: Application
    Filed: June 7, 2005
    Publication date: October 27, 2005
    Inventors: Hachiro Tosaka, Tomiaki Ito, Yuji Natori
  • Publication number: 20050118361
    Abstract: Disclosed is an intermediate transferring belt utilized in order to transfer a toner image formed by developing a latent image on an image bearing member by means of a toner, wherein the intermediate transferring belt comprises a matrix and conductive fine particles, the conductive fine particles are dispersed into the matrix, and the surface resistivity ?s of the outer surface of the intermediate transferring belt is 1.0×109 ohm/square to 1.0×1013 ohm/square, and wherein the intermediate transferring belt is applied to an image forming apparatus of which transferring electric field is controlled to 15 MV/m or less when the toner image on the image bearing member is primarily transferred to the intermediate transferring belt.
    Type: Application
    Filed: October 14, 2004
    Publication date: June 2, 2005
    Inventors: Yuji Natori, Minoru Matsuo
  • Patent number: 6889605
    Abstract: A heat-sensitive stencil including a resin film on which a thin resin layer and a porous resin layer are formed in succession.
    Type: Grant
    Filed: October 5, 2000
    Date of Patent: May 10, 2005
    Assignees: Ricoh Company, Ltd., Tohoku Ricoh, Co., Ltd.
    Inventors: Yuji Natori, Fumiaki Arai, Masanori Rimoto, Tetsuo Tanaka, Hiroshi Tateishi
  • Publication number: 20050014081
    Abstract: The toner according to the present invention may be produced from a toner raw composition which comprises a foaming agent, a binder resin and a colorant, wherein the colorant comprises a black metal compound, the foaming agent has a volume-average particle diameter of 2 ?m to 50 ?m, the toner raw composition turns into a porous mixture while the foaming agent expands at melting and kneading the toner raw composition, and the toner obtained through milling and classifying the porous mixture has a specific density of 1.0 g/cm3 to 1.3 g/cm3, wherein the specific density is determined as follows: 1 gram of toner is pressed at 400 kgf/cm2 for five minutes in a discal cavity having a diameter of 20 mm, then the discal toner is removed; the discal toner volume (V) is calculated from the diameter and height, measured at 10 minutes after releasing the pressure on the discal toner, and the discal toner mass (W) is measured; then the specific density is determined from the following formula: Specific Density (?T)=W/V.
    Type: Application
    Filed: June 9, 2004
    Publication date: January 20, 2005
    Inventors: Hachiroh Tosaka, Tomiaki Ito, Yuji Natori