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).

  • Publication number: 20120293582
    Abstract: A recording ink containing a pigment dispersion, a surfactant, a water-dispersible resin, a humectant and water. The pigment dispersion contains a pigment dispersant, which is an anionic surfactant or a nonionic surfactant having an HLB value of 10 to 20. The pigment dispersion also contains a polymer dispersion stabilizer, which is an alpha-olefin/maleic anhydride copolymer expressed by the formula (1) below, where R is an alkyl group having 6 to 25 carbon atoms, and where the mass average molecular weight of the copolymer is 5000 to 20000. An ink cartridge, an inkjet recording method, an inkjet recording apparatus, and an ink recorded matter, each employing the recording ink, are also provided.
    Type: Application
    Filed: June 26, 2012
    Publication date: November 22, 2012
    Inventors: Hiroshi Goto, Akihiko Matsuyama, Kiyofumi Nagai
  • Patent number: 8304043
    Abstract: There is provided an inkjet recording ink and recording media set, which contains: an inkjet recording ink; and a recording medium, wherein the inkjet recording ink comprises at least: water; a water-soluble organic solvent; and a colorant containing carbon black, and having a volume average particle diameter of 40 nm to 100 nm, wherein the recording medium contains: a substrate; and a coating layer on at least one side of the substrate, and wherein an amount of pure water transferred to the recording medium, as measured with a dynamic scanning absorptometer at 23 C and 50% RH, at a contact time of 100 ms is 2 ml/m2 to 35 ml/m2 while an amount of pure water transferred to the recording medium at a contact time of 400 ms is 3 ml/m2 to 40 ml/m2.
    Type: Grant
    Filed: March 14, 2008
    Date of Patent: November 6, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Hidefumi Nagashima, Kiyofumi Nagai, Michihiko Namba, Mariko Kojima
  • Patent number: 8303099
    Abstract: The object of the invention to provide a recording ink with excellent discharge stability and storage stability, which rapidly penetrates into a recording medium and forms a coating, and which will never generate smearing upon high-speed printing or double-sided printing, and which excels in marker resistance, and which enables high quality image recording with less bleeding, and the ink cartridge, the ink record, the inkjet recording apparatus, and the inkjet recording method using the recording ink. The recording ink containing at least water, a colorant, a resin fine-particle, a water-soluble organic solvent and a penetrant, in which the penetrant is a diol compound whose carbon number is 7 to 11 and the resin fine-particle is a silicone modified acrylic resin not containing a hydrolyzable silyl group.
    Type: Grant
    Filed: July 7, 2010
    Date of Patent: November 6, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Mariko Kojima, Tomohiro Inoue, Akihiko Gotoh, Michihiko Namba, Hisashi Habashi, Akiko Bannai, Kiyofumi Nagai
  • Patent number: 8252207
    Abstract: To provide an ink for inkjet recording containing water, water-soluble organic solvent, water-dispersible resin, fluorochemical surfactant or derivative thereof, and coloring agent containing pigment, wherein the ink has a surface tension of 20-35 mN/m and viscosity of 5 mPa·s or more at 25° C., total amount of the water-dispersible resin and the coloring agent in the ink is 5-40% by mass, and mass ratio A/B of the water-dispersible resin A to the coloring agent B is 0.5-4, wherein the ink is applied for a recording medium for inkjet recording containing a support containing cellulose pulp, and one or more barrier layers disposed on at least one face of the support, and wherein the barrier layer contains 30% by mass or more of inorganic pigment having refractive index of 1.5 or more, excluding aluminum hydrate, and 10% by mass or less of an inorganic pigment having a refractive index of less than 1.5.
    Type: Grant
    Filed: August 30, 2007
    Date of Patent: August 28, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Michihiko Namba, Akihiko Matsuyama, Naoya Morohoshi, Tohru Ohshima, Masayuki Koyano, Akihiko Gotoh, Kiyofumi Nagai
  • Patent number: 8242201
    Abstract: A pigment dispersion is provided that includes a pigment, a pigment dispersant, a polymer dispersion stabilizer and water, wherein the polymer dispersion stabilizer is an alpha-olefin/maleic anhydride copolymer expressed by the formula (1) below. A recording ink is also provided that includes the pigment dispersion, a surfactant, a water-dispersible resin, a humectant and water. In the structural formula (1), R represents an alkyl group and n is an integer of 30 to 100.
    Type: Grant
    Filed: December 15, 2006
    Date of Patent: August 14, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroshi Goto, Akihiko Matsuyama, Kiyofumi Nagai
  • Patent number: 8201935
    Abstract: The image recording method includes ejecting an ink to form an image on the surface of a recording layer of a recording medium; and then applying a glossiness imparting liquid on the surface of the recording medium. The ink includes a particulate colorant, a surfactant and water, and has a solid content of not lower than 6% by weight. The recording layer is located overlying a substrate including cellulose pulp as a main component and includes an inorganic pigment and a styrene-butadiene copolymer. The surface of the recording medium bearing the recording layer absorbs the ink in an amount of from 1 ml/m2 to 10 ml/m2 before coating the glossiness imparting liquid when the ink absorbing amount is measured with a dynamic scanning absorptometer at a contact time of 500 ms.
    Type: Grant
    Filed: January 7, 2010
    Date of Patent: June 19, 2012
    Assignee: Ricoh Company, Limited
    Inventors: Tohru Ohshima, Kiyofumi Nagai
  • Patent number: 8173227
    Abstract: There is provided a recording ink containing: solid constituents, which contain a colorant and a resin, and stay solid in the ink having a temperature of 25° C.; liquid constituents, which have a higher boiling point than a boiling point of water, and stay liquid in the ink having a temperature of 25° C.; and water, wherein a total amount of the solid constituents in the recording ink is in the range of 2.0% by mass or more to less than 20% by mass, wherein a ratio A/B of a total amount of the liquid constituents in the recording ink A to the total amount of the solid constituents in the recording ink B is from 0.70 to 1.75, and wherein the viscosity of the recording ink at 25° C. is 10 mPa s or less.
    Type: Grant
    Filed: September 12, 2007
    Date of Patent: May 8, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Naoya Morohoshi, Tamotsu Aruga, Michihiko Namba, Akihiko Gotoh, Kiyofumi Nagai
  • Publication number: 20120098883
    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: Application
    Filed: June 23, 2010
    Publication date: April 26, 2012
    Inventors: Akihiko Matsuyama, Ichiroh Fujii, Yuuki Yokohama, Kiyofumi Nagai, Hiroshi Gotou
  • Patent number: 8142849
    Abstract: To provide an inkjet recording method including: flying ink by application of stimulation to the ink to form an image on a recording media, wherein the recording media has at least one barrier layer of 10 m or less in thickness on at least one surface of a substrate comprising a cellulose pulp, the barrier layer contains 30% by mass or more of an inorganic pigment with a refraction index of 1.5 or less other than alumina, and the content of pigment with a refraction index of less than 1.5 in the barrier layer is 10% by mass or less, wherein the ink contains either a pigment or colored fine particle as coloring material, and a coloring material fixing constituent, and the surface tension of the ink is 25 mN/m or less, and the total amount of the ink on the recording media is 15 g/m2 or less.
    Type: Grant
    Filed: October 26, 2006
    Date of Patent: March 27, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Tohru Ohshima, Naoya Morohoshi, Kiyofumi Nagai
  • Patent number: 8118419
    Abstract: An ink-jet recording process which conducts recording by imparting ink onto the surface of a recording medium according to recording information, where the recording medium has a base material and a porous ink receiving layer thereon containing inorganic particles having a BET specific surface area of at least 150 m2/g, and the ink contains a polymer emulsion having a water-insoluble or hardly-soluble colorant contained in polymer fine particles and at least one wetting agent, 8-11 C polyol or glycol ether, anionic or nonionic surfactant, water-soluble organic solvent, and water; and has a surface tension of 40 mN/m or less at 25° C. This process can provide high-grade images excellent in ink absorbing and fixing properties and satisfactory in color tone, produce images excellent in image fastness such as water resistance and light resistance, and implement ink-jet recording excellent in storage stability and discharge stability and free from head clogging at printing.
    Type: Grant
    Filed: September 20, 2002
    Date of Patent: February 21, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Naoya Morohoshi, Masayuki Koyano, Akihiko Gotoh, Kiyofumi Nagai
  • Patent number: 8109622
    Abstract: The present invention provides a recording ink including a composite pigment particle, a water-soluble solvent, and water, wherein the composite pigment particle is a primary particle coated with a coating resin, wherein the primary particle is a white pigment on the surface of which an oil-soluble dye is adsorbed or attached. In one aspect, the white pigment is preferably at least one selected from a white inorganic pigment, a pearl pigment, and an extender pigment, in another aspect, the coating resin is preferably one of a (meth)acrylic resin, a polyester resin, and a polyurethane resin, wherein the acid value of the coating resin is from 50 mgKOH/g to 250 mgKOH/g, and in another aspect, an average particle diameter (D50%) of the composite pigment particle is preferably 150 nm or less.
    Type: Grant
    Filed: March 9, 2007
    Date of Patent: February 7, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroshi Goto, Akihiko Matsuyama, Kiyofumi Nagai
  • Patent number: 8110257
    Abstract: An ink-jet recording method including recording onto a recording medium a black image of composite black using a black ink and color inks, wherein the black ink includes water, a water-soluble organic solvent, a surfactant, and a carbon black whose volume average particle diameter is 40 nm to 100 nm, and the color inks include a cyan ink, a magenta ink and a yellow ink, wherein the mass ratio (A/B) of a solid content A to a water-soluble organic solvent content B in the black ink is in the range of 1/8 to 1/15, and wherein the recording medium includes a support with a coating layer, and the amounts of purified water transferred to the recording medium at contact periods of 100 ms and 400 ms at a temperature of 23 C and a relative humidity of 50% are 2 ml/m2 to 35 ml/m2 and 3 ml/m2 to 40 ml/m2 respectively.
    Type: Grant
    Filed: June 26, 2008
    Date of Patent: February 7, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Hidefumi Nagashima, Kiyofumi Nagai
  • Patent number: 8096651
    Abstract: An ink-jet recording method including: printing on a medium by ejecting thereon ink having a pH value of 8 or more and containing at least a particulate colorant, emulsion resin and surfactant, the medium prepared by providing at least a coat layer containing a pigment on at least one surface of a substrate containing cellulose pulp as a main component, wherein printing is performed at a deposited ink amount of 15 g/m2 or less, and wherein the medium has a pH value of 8 or more at a paper surface, and the amount of pure water transferring onto a surface of the medium having the coat layer after a contact time of 100 ms measured with a dynamic scanning absorptometer is 1 mL/m2 or less and the amount of pure water transferring onto the surface of the medium after a contact time of 400 ms is 35 mL/m2 or less.
    Type: Grant
    Filed: March 17, 2008
    Date of Patent: January 17, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Tohru Ohshima, Kiyofumi Nagai, Naoya Morohoshi, Michihiko Namba
  • Publication number: 20110316947
    Abstract: An inkjet recording ink including at least a pigment, fine resin particles, a water soluble organic solvent, and water, wherein a polymer chain is grafted onto a surface of the pigment, and the polymer chain is composed of at least one monomer unit, which is selected from the monomers represented by the following Chemical Formulas (1) to (4): Chemical Formula (1) where R1 represents H or CH3, and “n” represents the number of carbon atoms; Chemical Formula (2) where R2 and R3 each represent H or CH3, and “m” represents the number of units repeated; Chemical Formula (3) where R4 and R5 each represent H or CH3, and “p” is the number of units repeated; and Chemical Formula (4) where R6 and R7 each represent H or CH3, and “k” and “l” each represent the number of units repeated.
    Type: Application
    Filed: March 4, 2010
    Publication date: December 29, 2011
    Inventors: Mariko Kojima, Kiyofumi Nagai
  • Publication number: 20110300353
    Abstract: There is provided an ink for recording, which contains: a coloring agent; a water-dispersible resin; a wetting agent; a surfactant; and water, wherein a total solid content of the coloring agent and the water-dispersible resin is 10% by mass to 30% with respect to a total mass of the ink, a ratio B/C is 0.1 to 1.6 where B is a solid content of the coloring agent in the ink, and C is a solid content of the water-dispersible resin in the ink, a viscosity of the ink is 5 mPa·s to 20 mPa·s at 25° C., and a surface tension of the ink is 35 mN/m or less.
    Type: Application
    Filed: August 22, 2011
    Publication date: December 8, 2011
    Inventors: Hisashi HABASHI, Michihiko NAMBA, Mariko KOJIMA, Akihiko GOTOH, Tamotsu ARUGA, Kiyofumi NAGAI
  • Patent number: 8044114
    Abstract: There is provided an ink for recording, which contains: a coloring agent; a water-dispersible resin; a wetting agent; a surfactant; and water, wherein a total solid content of the coloring agent and the water-dispersible resin is 10% by mass to 30% with respect to a total mass of the ink, a ratio B/C is 0.1 to 1.6 where B is a solid content of the coloring agent in the ink, and C is a solid content of the water-dispersible resin in the ink, a viscosity of the ink is 5 mPa·s to 20 mPa·s at 25° C., and a surface tension of the ink is 35 mN/m or less.
    Type: Grant
    Filed: August 22, 2006
    Date of Patent: October 25, 2011
    Assignee: Ricoh Company, Ltd.
    Inventors: Hisashi Habashi, Michihiko Namba, Mariko Kojima, Akihiko Gotoh, Tamotsu Aruga, Kiyofumi Nagai
  • Patent number: 8029122
    Abstract: A recording ink containing at least: water; a water-soluble organic solvent; a surfactant; and a carbon black having a hydrophilic group on a surface thereof, wherein at least part of a terminal of the hydrophilic group on the carbon black is substituted with an alkali metal, wherein the carbon black releases humic acid in an aqueous dispersion of the carbon black, which is recovered from the recording ink, a concentration of the humic acid released in the aqueous dispersion containing 20% by mass of the carbon black of is expressed with a maximum absorbance at a wavelength of 230 nm to 260 nm, and the recording ink has the maximum absorbance of 5.0 to 20.0 at the wavelength of 230 nm to 260 nm.
    Type: Grant
    Filed: September 12, 2007
    Date of Patent: October 4, 2011
    Assignee: Ricoh Company, Ltd.
    Inventors: Mariko Kojima, Kiyofumi Nagai, Akihiko Gotoh, Akiko Bannai, Tomohiro Inoue
  • Publication number: 20110216123
    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: Application
    Filed: March 2, 2011
    Publication date: September 8, 2011
    Inventors: Takashi TAMAI, Michihiko NAMBA, Akihiko MATSUYAMA, Akihiko GOTOH, Kiyofumi NAGAI
  • Publication number: 20110205288
    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: Application
    Filed: October 29, 2009
    Publication date: August 25, 2011
    Inventors: Akihiko Matsuyama, Ichiroh Fujii, Yuuki Yokohama, Kiyofumi Nagai, Akihiko Gotoh, Mariko Kojima, Masaki Kudoh, Tomohiro Nakagawa
  • Patent number: 7950793
    Abstract: The object of the present invention is to provide a recording ink having excellent color developing properties and high delivery stability, by which not only the color saturation of the obtained image can be remarkably improved, but also the image having a high quality can be formed. For this object, the present invention provides a recording ink used for an inkjet recording using a dye ink and a pigment ink properly alternately through one inkjet head, wherein the dye ink and the pigment ink have respectively a viscosity at 25° C. of 5 mPa·s or more and the difference between the viscosity of the dye ink and the viscosity of the pigment ink is 3 mPa·s or less.
    Type: Grant
    Filed: April 6, 2005
    Date of Patent: May 31, 2011
    Assignee: Ricoh Company, Ltd.
    Inventors: Tamotsu Aruga, Kiyofumi Nagai