Patents by Inventor Kiyofumi Nagai

Kiyofumi Nagai 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).

  • Patent number: 10703911
    Abstract: Organic colorant represented by General Formula (1) below: where in the General Formula (1), R1 and R2 each independently represent C1-C20 alkyl group, C1-C20 alkenyl group, phenyl group, naphthyl group, or group represented by —(CH2)n—COO—R3, —(CH2)n—R4, —(CH2)n—CONH—R5, —CR6R7—COO—R8, or —(CH2)n—OCOCH3; R3 represents hydrogen atom or C1-C2 alkyl group; R4 represents hydroxy group, C1-C2 alkoxy group, C2-C5 alkenyloxy group, SO3Na group, OSO3Na group, phenyl group, phenylalkyl group, naphthyl group, or naphthylalkyl group; R5 represents C1-C20 alkyl group, C1-C20 alkenyl group, or C1-C12 hydroxyalkyl group; R6 represents hydrogen atom or methyl group; R7 represents C1-C4 alkyl group; R8 represents C1-C5 alkyl group; and n is integer of from 1 to 12.
    Type: Grant
    Filed: July 5, 2018
    Date of Patent: July 7, 2020
    Assignees: Ricoh Company, Ltd., Tokyo University of Science Foundation
    Inventors: Takuya Fujita, Yoshimasa Miyazawa, Tatsuya Tomura, Masahiro Yanagisawa, Kiyofumi Nagai, Yukishige Kondo, Juki Migii
  • Publication number: 20190010331
    Abstract: Organic colorant represented by General Formula (1) below: where in the General Formula (1), R1 and R2 each independently represent C1-C20 alkyl group, C1-C20 alkenyl group, phenyl group, naphthyl group, or group represented by —(CH2)n—COO—R3, —(CH2)n—R4, —(CH2)n—CONH—R5, —CR6R7—COO—R8, or —(CH2)n—OCOCH3; R3 represents hydrogen atom or C1-C2 alkyl group; R4 represents hydroxy group, C1-C2 alkoxy group, C2-C5 alkenyloxy group, SO3Na group, OSO3Na group, phenyl group, phenylalkyl group, naphthyl group, or naphthylalkyl group; R5 represents C1-C20 alkyl group, C1-C20 alkenyl group, or C1-C12 hydroxyalkyl group; R6 represents hydrogen atom or methyl group; R7 represents C1-C4 alkyl group; R8 represents C1-C5 alkyl group; and n is integer of from 1 to 12.
    Type: Application
    Filed: July 5, 2018
    Publication date: January 10, 2019
    Inventors: Takuya Fujita, Yoshimasa Miyazawa, Tatsuya Tomura, Masahiro Yanagisawa, Kiyofumi Nagai, Yukishige Kondo, Juki Migii
  • Patent number: 9879207
    Abstract: A cleaning filling liquid for inkjet device including water; 10.0% by mass to 45% by mass per whole amount of the cleaning filling liquid of an amide compound having following formula (1).
    Type: Grant
    Filed: February 17, 2016
    Date of Patent: January 30, 2018
    Assignee: RICOH COMPANY, LTD.
    Inventors: Takashi Tamai, Tomohiro Inoue, Hiroshi Gotou, Michihiko Namba, Akihiko Gotoh, Kiyofumi Nagai
  • Patent number: 9518190
    Abstract: To provide an inkjet ink, which contains: water; a wetting agent; a surfactant; and a colorant, wherein the wetting agent contains at least an amide compound represented by the following structural formula (I):
    Type: Grant
    Filed: June 15, 2015
    Date of Patent: December 13, 2016
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroshi Gotou, Kiyofumi Nagai, Michihiko Namba, Hidetoshi Fujii, Yuuki Yokohama
  • Publication number: 20160160161
    Abstract: A cleaning filling liquid for inkjet device comprising: Water; 10.0% by mass to 45% by mass per whole amount of the cleaning filling liquid of an amide compound having following structural formula (1).
    Type: Application
    Filed: February 17, 2016
    Publication date: June 9, 2016
    Inventors: Takashi TAMAI, Tomohiro INOUE, Hiroshi GOTOU, Michihiko NAMBA, Akihiko GOTOH, Kiyofumi NAGAI
  • Publication number: 20150307729
    Abstract: To provide an inkjet ink, which contains: water; a wetting agent; a surfactant; and a colorant, wherein the wetting agent contains at least an amide compound represented by the following structural formula (I)
    Type: Application
    Filed: June 15, 2015
    Publication date: October 29, 2015
    Inventors: Hiroshi GOTOU, Kiyofumi Nagai, Michihiko Namba, Hidetoshi Fujii, Yuuki Yokohama
  • Patent number: 9163160
    Abstract: Aqueous ink for inkjet contains water; a hydrosoluble organic solvent; a pigment; and a resin, wherein the hydrosoluble organic solvent contains 2,3-butane diol having meso-2,3-butane diol in an amount of 50% by weight or more in 2,3-butane diol and 2,3-butane diol accounts for 5% by weight to 40% by weight of the entire of the aqueous ink.
    Type: Grant
    Filed: September 10, 2014
    Date of Patent: October 20, 2015
    Assignee: RICOH COMPANY, LTD.
    Inventors: Naohiro Toda, Tomohiro Nakagawa, Hidefumi Nagashima, Juichi Furukawa, Ichiroh Fujii, Kiyofumi Nagai
  • Patent number: 9085706
    Abstract: To provide an inkjet ink, which contains: water; a wetting agent; a surfactant; and a colorant, wherein the wetting agent contains at least an amide compound represented by the following structural formula (I):
    Type: Grant
    Filed: July 29, 2011
    Date of Patent: July 21, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroshi Gotou, Kiyofumi Nagai, Michihiko Namba, Hidetoshi Fujii, Yuuki Yokohama
  • Patent number: 9062217
    Abstract: A liquid composition for agglutinating particles having a negative charge which are dispersed in a dispersion liquid, the liquid composition including: an organic acid ammonium salt represented by Formula (1), and water, Formula (1) where R1 represents a hydroxyl group, a methyl group or a hydrogen atom; and R2 represents a hydroxyl group or a methyl group.
    Type: Grant
    Filed: June 15, 2011
    Date of Patent: June 23, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroshi Gotou, Hidetoshi Fujii, Kiyofumi Nagai
  • Patent number: 9034091
    Abstract: An inkjet recording ink set including a black ink and color inks, wherein the black ink and the color inks each contain at least a dye, a water-soluble solvent and water and each have a viscosity of 5 mPa-s to 20 mPa-s at 25° C., and wherein the respective color inks each satisfy a mass ratio relationship of S/W?1, and the black ink satisfies a mass ratio relationship of S/W<1, where S denotes an amount of the water-soluble solvent contained in the respective inks, and W denotes an amount of the water contained in the respective inks.
    Type: Grant
    Filed: February 23, 2011
    Date of Patent: May 19, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Akihiko Matsuyama, Kiyofumi Nagai
  • Patent number: 9028600
    Abstract: An inkjet ink, which contains water, an organic solvent, a surfactant, and a colorant, wherein the organic solvent contains at least one polyhydric alcohol having an equilibrium moisture content of 30% by mass or higher at a temperature of 23° C.
    Type: Grant
    Filed: March 9, 2012
    Date of Patent: May 12, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroshi Goto, Akihiko Gotoh, Kiyofumi Nagai, Yuuki Yokohama, Hidetoshi Fujii
  • Publication number: 20150077482
    Abstract: Aqueous ink for inkjet contains water; a hydrosoluble organic solvent; a pigment; and a resin, wherein the hydrosoluble organic solvent contains 2,3-butane diol having meso-2,3-butane diol in an amount of 50% by weight or more in 2,3-butane diol and 2,3-butane diol accounts for 5% by weight to 40% by weight of the entire of the aqueous ink.
    Type: Application
    Filed: September 10, 2014
    Publication date: March 19, 2015
    Applicant: RICOH COMPANY, LTD.
    Inventors: Naohiro Toda, Tomohiro Nakagawa, Hidefumi Nagashima, Juichi Furukawa, Ichiroh Fujii, Kiyofumi Nagai
  • Patent number: 8980408
    Abstract: A liquid composition containing: a water-soluble cationic polymer obtained by polymerizing monomers containing epihalohydrin and at least one of amine and amide; and water, wherein the liquid composition is for agglutinating negatively charged particles which are dispersed in a dispersion liquid.
    Type: Grant
    Filed: August 18, 2011
    Date of Patent: March 17, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroshi Gotou, Hidetoshi Fujii, Kiyofumi Nagai
  • Patent number: 8899719
    Abstract: An image forming method includes discharging an inkjet ink including a water-dispersible colorant, a wetter, a surfactant, a penetrant water-dispersible polyurethane resin having a median diameter of from 0.01 to 0.10 ?m water and at least one of a polyethylene wax and a paraffin wax on the surface of the recording medium on which the inkjet ink is discharged.
    Type: Grant
    Filed: November 7, 2013
    Date of Patent: December 2, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Hidefumi Nagashima, Michihiko Namba, Kiyofumi Nagai
  • Patent number: 8857962
    Abstract: An image forming method of the present invention including applying a pretreatment liquid to a recording medium, and discharging an inkjet recording ink dropwise according to an image signal to form an image on the recording medium on which the pretreatment liquid has been applied, wherein the recording medium is regular paper which has no coat layer, the pretreatment liquid contains a cationic polymer compound, a surfactant A, water and a water-soluble organic acid, and the inkjet recording ink contains a water-dispersible colorant, a water-soluble organic solvent, a surfactant B, a penetrating agent and water, and wherein the pretreatment liquid has a static surface tension of 20 mN/m to 30 mN/m.
    Type: Grant
    Filed: January 16, 2009
    Date of Patent: October 14, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroshi Goto, Hisashi Habashi, Kiyofumi Nagai
  • Patent number: 8845091
    Abstract: A printing medium including at least base paper and a coating layer, wherein the coating layer is directly formed on the base paper by a cast coating method using a coating liquid, which contains kaolin and amorphous silica and contains the amorphous silica in an amount of 3% by mass to 20% by mass.
    Type: Grant
    Filed: March 17, 2010
    Date of Patent: September 30, 2014
    Assignees: Ricoh Company, Ltd., Hokuetsu Kishu Paper Co., Ltd.
    Inventors: Tohru Ohshima, Michihiko Namba, Kiyofumi Nagai, Atsushi Hasegawa, Shuichi Oguma, Hisanori Sakatsume
  • Publication number: 20140192112
    Abstract: An image forming method includes discharging an inkjet ink including a water-dispersible colorant, a wetter, a surfactant, a penetrant water-dispersible polyurethane resin having a median diameter of from 0.01 to 0.10 ?m water and at least one of a polyethylene wax and a paraffin wax on the surface of the recording medium on which the inkjet ink is discharged.
    Type: Application
    Filed: November 7, 2013
    Publication date: July 10, 2014
    Applicant: RICOH COMPANY, LTD.
    Inventors: Hidefumi NAGASHIMA, Michihiko Namba, Kiyofumi Nagai
  • Patent number: 8752948
    Abstract: An inkjet recording ink including a water-soluble organic solvent, a colorant, at least one fluorine-based surfactant having a chemical structure represented by Structural Formula (I) below, and water, where Rf represents any one of CF3, CF2CF3, (CF2)3F, and (CF2)4F, and X plus Y is an integer of 4 or 5.
    Type: Grant
    Filed: March 2, 2011
    Date of Patent: June 17, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Takashi Tamai, Michihiko Namba, Akihiko Matsuyama, Akihiko Gotoh, Kiyofumi Nagai
  • Patent number: 8746869
    Abstract: An ink for inkjet recording, containing: dispersed particles A; dispersed particles B; a water-soluble solvent; a surfactant; and water, wherein the dispersed particles A are coloring particles obtained by dispersing an organic pigment in water with assistance of a surfactant, and the dispersed particles B are coloring particles obtained by dispersing a polymer-coated organic pigment in water.
    Type: Grant
    Filed: June 23, 2010
    Date of Patent: June 10, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Akihiko Matsuyama, Ichiroh Fujii, Yuuki Yokohama, Kiyofumi Nagai, Hiroshi Gotou
  • Patent number: 8651650
    Abstract: An inkjet recording ink containing a colorant, a surfactant A, a surfactant B, a water soluble organic solvent, and water, wherein the surfactant A is expressed by any one of Structural Formula (1) and Structural Formula (2), and the surfactant B is expressed by Structural Formula (3): in Structural Formula (1), R1 represents hydrogen, an alkyl group, or an acyl group; Rf represents —CF3 or —CF2CF3; and m, n and p are natural numbers; in Structural Formula (2), M represents alkali metal, ammonium, phosphonium, or alkanolamine; Rf represents —CF3 or —CF2CF3; and q is a natural number; in Structural Formula (3), R3 and R4 each represent hydrogen or an alkyl group; and r, s, t and u are natural numbers.
    Type: Grant
    Filed: October 29, 2009
    Date of Patent: February 18, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Akihiko Matsuyama, Ichiroh Fujii, Yuuki Yokohama, Kiyofumi Nagai, Akihiko Gotoh, Mariko Kojima, Masaki Kudoh, Tomohiro Nakagawa