Patents by Inventor Michihiko Namba

Michihiko Namba 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: 20100245416
    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 30 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: Application
    Filed: March 17, 2008
    Publication date: September 30, 2010
    Inventors: Tohru Ohshima, Kiyofumi Nagai, Naoya Morohoshi, Michihiko Namba
  • Publication number: 20100227067
    Abstract: An ink-jet recording ink including water, a water-soluble organic solvent, a pigment (P1) as a colorant (B), and at least one fluorochemical surfactant selected from compounds represented by Structural Formula (1) below, where R1 denotes any one of a hydrogen atom, an alkyl group and a fluorine-containing group, Rf denotes a fluorine-containing group, and each of x, y and z denotes an integer of 1 or greater.
    Type: Application
    Filed: November 20, 2008
    Publication date: September 9, 2010
    Inventors: Michihiko Namba, Naoya Morohoshi, Tohru Ohshima, Akihiko Gotoh, Kiyofumi Naigai
  • Patent number: 7699457
    Abstract: The recording ink having a water, a water-soluble organic solvent, a colorant, and at least one fluorochemical surfactant selected from the following Structural Formulae (1) to (3). Structural Formula (1): where, Rf is a fluorine-containing group; and m, n, and p are integers in the Structural Formula (1). Structural Formula (2): where, Rf is a fluorine-containing group; X is a cationic group; Y is an anionic group; and q is an integer in the Structural Formula (2). Structural Formula (3): where, Rf is a fluorine-containing group; X is a cationic group; Y is an anionic group; and q is an integer in the Structural Formula (3).
    Type: Grant
    Filed: September 13, 2005
    Date of Patent: April 20, 2010
    Assignee: Ricoh Company, Ltd.
    Inventors: Michihiko Namba, Hisashi Habashi, Akihiko Gotoh, Kiyofumi Nagai, Tomohiro Inoue
  • Patent number: 7682011
    Abstract: The object of the present invention is to provide a recording ink which is excellent in color developing properties, has a high delivery stability, can improve remarkably color saturation and can form a high-quality image, when the ink is used for printing a plain paper, further an ink cartridge, an ink record, an inkjet recording apparatus and an inkjet recording process, wherein the recording ink having water, a wetting agent, a surfactant, and a colorant.
    Type: Grant
    Filed: January 10, 2007
    Date of Patent: March 23, 2010
    Assignee: Ricoh Company, Ltd.
    Inventors: Michihiko Namba, Hisashi Habashi, Mariko Kojima, Tomohiro Inoue, Akiko Bannai, Akihiko Gotoh, Kiyofumi Nagai
  • Publication number: 20090263632
    Abstract: The present invention provides a recording ink set containing a black ink, a cyan ink, a magenta ink, and a yellow ink, each of which contains water, a water-insoluble color material, a water-soluble organic solvent, and a surfactant, wherein the black ink and at least one of the inks other than the black ink respectively contain a different water-soluble organic solvent; and the surface tension of the water-soluble organic solvent(s) used only for the inks other than the black ink is higher than that of the water-soluble organic solvent used only for the black ink; and the present invention also provides a recording method using the recording ink set.
    Type: Application
    Filed: October 24, 2006
    Publication date: October 22, 2009
    Inventors: Mariko Kojima, Akihiko Gotoh, Michihiko Namba, Kiyofumi Nagai, Naoya Morohoshi, Tohru Ohshima
  • Publication number: 20090258196
    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: Application
    Filed: March 14, 2008
    Publication date: October 15, 2009
    Inventors: Hidefumi Nagashima, Kiyofumi Nagai, Michihiko Namba, Mariko Kojima
  • Publication number: 20090239044
    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, 2006
    Publication date: September 24, 2009
    Inventors: Hisashi Habashi, Michihiko Namba, Mariko Kojima, Akihiko Gotoh, Tamotsu Aruga, Kiyofumi Nagai
  • Publication number: 20090186162
    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 inorganic pigment having a refractive index of less than 1.5.
    Type: Application
    Filed: August 30, 2007
    Publication date: July 23, 2009
    Inventors: Michihiko Namba, Akihiko Matsuyama, Naoya Morohoshi, Tohru Ohshima, Masayuki Koyano, Akihiko Gotoh, Kiyofumi Nagai
  • Publication number: 20090162569
    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: Application
    Filed: September 12, 2007
    Publication date: June 25, 2009
    Inventors: Naoya Morohoshi, Tamotsu Aruga, Michihiko Namba, Akihiko Gotoh, Kiyofumi Nagai
  • Publication number: 20080248260
    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: Application
    Filed: September 16, 2005
    Publication date: October 9, 2008
    Applicant: RICOH COMPANY, LTD.
    Inventors: Mariko Kojima, Tomohiro Inoue, Akihiko Gotoh, Michihiko Namba, Hisashi Habashi, Akiko Bannai, Kiyofumi Nagai
  • Publication number: 20080070008
    Abstract: The recording ink having a water, a water-soluble organic solvent, a colorant, and at least one fluorochemical surfactant selected from the following Structural Formulae (1) to (3). Structural Formula (1): where, Rf is a fluorine-containing group; and m, n, and p are integers in the Structural Formula (1). Structural Formula (2): where, Rf is a fluorine-containing group; X is a cationic group; Y is an anionic group; and q is an integer in the Structural Formula (2). Structural Formula (3): where, Rf is a fluorine-containing group; X is a cationic group; Y is an anionic group; and q is an integer in the Structural Formula (3).
    Type: Application
    Filed: September 13, 2005
    Publication date: March 20, 2008
    Inventors: Michihiko Namba, Hisashi Habashi, Akihiko Gotoh, Kiyofumi Nagai, Tomohiro Inoue
  • Patent number: 7284851
    Abstract: A recording ink including a colorant dispersible in water, a humectant, a surfactant, and a wetting agent, wherein the rate of viscosity increase associated with evaporation of moisture in the recording ink is 5.0 mPa·s/% or less while the evaporated moisture content is less than 30% by weight based on the whole weight of the recording ink, the rate of viscosity increase associated with evaporation of moisture exceeds 50 mPa·s/% while the evaporated moisture content is 30 to 45% by weight, and the average particle size of the colorant in the recording ink is less than five times the average particle size of the colorant in the initial recording ink, and is 0.8 ?m or less, at the stage of the recording ink when the rate of viscosity increase amounts to 50 mPa·s/%, wherein the rate of viscosity increase associated with evaporation of moisture (mPa·s/%) is defined as the increment of viscosity (mPa·s) versus the increment of evaporated moisture content (%).
    Type: Grant
    Filed: February 28, 2005
    Date of Patent: October 23, 2007
    Assignee: Ricoh Company, Ltd.
    Inventors: Akiko Bannai, Kiyofumi Nagai, Akihiko Gotoh, Mariko Kojima, Michihiko Namba, Tomohiro Inoue
  • Publication number: 20070221078
    Abstract: The object of the present invention is to provide a recording ink which is excellent in color developing properties, has a high delivery stability, can improve remarkably color saturation and can form a high-quality image, when the ink is used for printing a plain paper, further an ink cartridge, an ink record, an inkjet recording apparatus and an inkjet recording process.
    Type: Application
    Filed: March 17, 2005
    Publication date: September 27, 2007
    Inventors: Michihiko Namba, Hisashi Habashi, Mariko Kojima, Tomohiro Inoue, Akiko Bannai, Akihiko Gotoh, Kiyofumi Nagai
  • Patent number: 7122284
    Abstract: An electrophotographic photoconductor has an electroconductive support and a photoconductive layer which is formed thereon and contains at least one resin of a polyurethane resin, a polyester resin, or a polycarbonate resin, each resin having at least a structural unit of formula (1): wherein R1, R2, R3, a, b, and n are the same as those specified in the specification. An electrophotographic image forming apparatus and method, and a process cartridge employ the above photoconductor.
    Type: Grant
    Filed: October 6, 2005
    Date of Patent: October 17, 2006
    Assignee: Ricoh Company, Ltd.
    Inventors: Shinichi Kawamura, Kazukiyo Nagai, Tomoyuki Shimada, Chiaki Tanaka, Michihiko Namba
  • Patent number: 7094813
    Abstract: An ink and ink set characterized in that both a combination of a specific wetting agent, penetrating agent, and water-soluble organic solvent and use of surfactant, particularly fluorine surfactant are enabled by using water dispersion in which polymer fine particles contain coloring material. Even when plain paper is printed at high speed by ink-jet recording by using this ink and ink set, the ink and ink set can realize a pigment ink for ink-jet recording, an ink set, an ink-jet recording method, ink cartridge, and recorder which have an excellent ejection stability and excellent preservability, and provide (1) good color tone, (2) high image density, (3) recorded image free of unsharpness near character or image and feathering and high in sharpness, (4) less boundary color bleedings between different colors, (5) image adaptable to both-side printing and causing less strike-throughs, and (6) image fastness such as water resistance and light resistance.
    Type: Grant
    Filed: August 5, 2004
    Date of Patent: August 22, 2006
    Assignee: Ricoh Company, Ltd.
    Inventors: Michihiko Namba, Toshiroh Tokuno, Akihiko Gotoh, Kiyofumi Nagai
  • Patent number: 7056633
    Abstract: An electrophotographic photoconductor has an electroconductive support and a photoconductive layer which is formed thereon and contains at least one resin of a polyurethane resin, a polyester resin, or a polycarbonate resin, each resin having at least a structural unit of formula (1): wherein R1, R2, R3, a, b, and n are the same as those specified in the specification. An electrophotographic image forming apparatus and method, and a process cartridge employ the above photoconductor.
    Type: Grant
    Filed: February 12, 2003
    Date of Patent: June 6, 2006
    Assignee: Ricoh Company, Ltd.
    Inventors: Shinichi Kawamura, Kazukiyo Nagai, Tomoyuki Shimada, Chiaki Tanaka, Michihiko Namba
  • Publication number: 20060035161
    Abstract: An electrophotographic photoconductor has an electroconductive support and a photoconductive layer which is formed thereon and contains at least one resin of a polyurethane resin, a polyester resin, or a polycarbonate resin, each resin having at least a structural unit of formula (1): wherein R1, R2, R3, a, b, and n are the same as those specified in the specification. An electrophotographic image forming apparatus and method, and a process cartridge employ the above photoconductor.
    Type: Application
    Filed: October 6, 2005
    Publication date: February 16, 2006
    Applicant: RICOH COMPANY, LTD.
    Inventors: Shinichi Kawamura, Kazukiyo Nagai, Tomoyuki Shimada, Chiaki Tanaka, Michihiko Namba
  • Patent number: 6974654
    Abstract: An electrophotographic photoconductor has an electroconductive support and a photoconductive layer which is formed thereon and contains at least one resin of a polyurethane resin, a polyester resin, or a polycarbonate resin, each resin having at least a structural unit of formula (1): wherein R1, R2, R3, a, b, and n are the same as those specified in the specification. An electrophotographic image forming apparatus and method, and a process cartridge employ the above photoconductor.
    Type: Grant
    Filed: December 16, 2003
    Date of Patent: December 13, 2005
    Assignee: Ricoh Company, Ltd.
    Inventors: Shinichi Kawamura, Kazukiyo Nagai, Tomoyuki Shimada, Chiaki Tanaka, Michihiko Namba
  • Publication number: 20050231575
    Abstract: A recording ink comprising a colorant dispersible in water, a humectant, a surfactant, and a wetting agent, wherein the rate of viscosity increase associated with evaporation of moisture in the recording ink is 5.0 mPa·s/% or less while the evaporated moisture content is less than 30% by weight based on the whole weight of the recording ink, the rate of viscosity increase associated with evaporation of moisture exceeds 50 mPa·s/% while the evaporated moisture content is 30 to 45% by weight, and the average particle size of the colorant in the recording ink is less than five times the average particle size of the colorant in the initial recording ink, and is 0.8 ?m or less, at the stage of the recording ink when the rate of viscosity increase amounts to 50 mPa·s/%, wherein the rate of viscosity increase associated with evaporation of moisture (mPa·s/%) is defined as the increment of viscosity (mPa·s) versus the increment of evaporated moisture content (%).
    Type: Application
    Filed: February 28, 2005
    Publication date: October 20, 2005
    Inventors: Akiko Bannai, Kiyofumi Nagai, Akihiko Gotoh, Mariko Kojima, Michihiko Namba, Tomohiro Inoue
  • Publication number: 20050054751
    Abstract: An ink and ink set characterized in that both a combination of a specific wetting agent, penetrating agent, and water-soluble organic solvent and use of surfactant, particularly fluorine surfactant are enabled by using water dispersion in which polymer fine particles contain coloring material. Even when plain paper is printed at high speed by ink-jet recording by using this ink and ink set, the ink and ink set can realize a pigment ink for ink-jet recording, an ink set, an ink-jet recording method, ink cartridge, and recorder which have an excellent ejection stability and excellent preservability, and provide (1) good color tone, (2) high image density, (3) recorded image free of unsharpness near character or image and feathering and high in sharpness, (4) less boundary color bleedings between different colors, (5) image adaptable to both-side printing and causing less strike-throughs, and (6) image fastness such as water resistance and light resistance.
    Type: Application
    Filed: August 5, 2004
    Publication date: March 10, 2005
    Inventors: Michihiko Namba, Toshiroh Tokuno, Akihiko Gotoh, Kiyofumi Nagai