Patents by Inventor Shinichi Wakamatsu

Shinichi Wakamatsu 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: 8932788
    Abstract: The present invention provides a toner containing at least a binder resin and a pigment, wherein the amount of the pigment in the toner is 3.0% by mass to 8.5% by mass, the volume average particle diameter of the toner is 2.0 ?m to 6.0 ?m, and a monochrome image, which has been fixed on a recording medium so that the amount of the toner adhered onto the recording medium is 0.25 mg/cm2, has a reflection density of 1.2 to 2.5.
    Type: Grant
    Filed: October 6, 2008
    Date of Patent: January 13, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Shinichi Wakamatsu, Hiroshi Yamashita, Naohiro Watanabe, Tsuyoshi Sugimoto
  • Publication number: 20140200326
    Abstract: To provide a polymer product, which is substantially free from an organic solvent and a metal atom, and has a number average molecular weight of 12,000 or greater.
    Type: Application
    Filed: August 6, 2012
    Publication date: July 17, 2014
    Inventors: Yoshitaka Yamauchi, Chiaki Tanaka, Taichi Nemoto, Kazumi Suzuki, Keiko Osaka, Shinichi Wakamatsu, Satomi Sabu
  • Patent number: 8673528
    Abstract: A toner including at least one polyester resin serving as a binder resin, a colorant, a releasing agent, and a fixing aid, wherein the fixing aid includes a fatty acid amide-based compound, and the fatty acid amide-based compound is at least one of a fatty acid amide compound having a mono- or higher valent amide bond and a fatty acid amide-based compound having a mono- or higher valent amino group or a hydroxyl group.
    Type: Grant
    Filed: May 22, 2009
    Date of Patent: March 18, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Tsuyoshi Sugimoto, Hiroshi Yamashita, Naohiro Watanabe, Shinichi Wakamatsu, Masaki Watanabe, Satoshi Ogawa, Masana Shiba, Junichi Awamura, Naohito Shimota
  • Patent number: 8557491
    Abstract: A toner according to the present invention contains at least a polyester resin as a binder resin, a colorant, a releasing agent, a fixing-assisting component, and a fatty acid, wherein the fixing-assisting component has a melting point of 60° C. to 120° C. and contains at least one of an esterified compound obtained by esterification of the fatty acid and an amide compound obtained by amidation of the fatty acid.
    Type: Grant
    Filed: July 27, 2009
    Date of Patent: October 15, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Tsuyoshi Sugimoto, Naohito Shimota, Hiroshi Yamashita, Naohiro Watanabe, Shinichi Wakamatsu, Masaki Watanabe
  • Patent number: 8541020
    Abstract: The invention aims at providing a polymeric hydrogel which is highly resistant to water washing. The aim is attained by a polymeric hydrogel comprising a polymeric matrix formed by copolymerizing a nonionic polymerizable monomer with a crosslinking monomer, characterized in that the polymeric matrix contains a wetting agent and water, at least 50 wt % of the wetting agent is constituted of a polymer prepared by polymerizing a polyhydric alcohol monomer component containing a trihydric or more alcohol monomer, and the polymer is a water-soluble one which has an average molecular weight of 150 to 4000 and satisfies the relationship: {(number of ether groups in the polymer+number of hydroxyl groups in the polymer)/number of carbon atoms present in the polymer}?1/3.
    Type: Grant
    Filed: September 17, 2002
    Date of Patent: September 24, 2013
    Assignee: Seikisui Plastics Co., Ltd.
    Inventors: Shuichi Sasahara, Kazuhiro Yosikawa, Shinichi Wakamatsu, Takahiko Fujita
  • Patent number: 8486596
    Abstract: A toner produced by a method including dissolving or dispersing toner components comprising a colorant and at least one of a binder resin and a precursor thereof in an organic solvent to prepare a toner components liquid, dispersing the toner components liquid in an aqueous medium including a surfactant, a particulate resin A having the same polarity as the surfactant and a volume average particle diameter of from 5 to 50 nm, and a particulate resin B having a volume average particle diameter of from 10 to 500 nm to form liquid droplets, and removing the organic solvent from the liquid droplets. The particulate resin B is incompatible with the binder resin and swells in the organic solvent.
    Type: Grant
    Filed: June 26, 2009
    Date of Patent: July 16, 2013
    Assignee: Ricoh Company, Limited
    Inventors: Masaki Watanabe, Hiroshi Yamashita, Tsuyoshi Sugimoto, Naohiro Watanabe, Shinichi Wakamatsu
  • Patent number: 8293442
    Abstract: Disclosed is a resin particle having a volume average particle diameter of 10 nm to 500 nm, obtained by polymerizing an addition polymerizable monomer containing a silsesquioxane (a) represented by Formula (I) or by copolymerizing the silsesquioxane (a) with an addition polymerizable monomer (b), where R1 to R7 each independently represent a group selected from the group consisting of hydrogen, alkyl having 1 to 40 carbon atoms, substituted or unsubstituted aryl, and substituted or unsubstituted arylalkyl; any hydrogen in the alkyl group is optionally substituted by fluorine and any —CH2— is optionally substituted by —O—, —CH?CH—, cycloalkylene or cycloalkenylene; any hydrogen in alkylene in the arylalkyl group is optionally substituted by fluorine and any —CH2— is optionally substituted by —O— or —CH?CH—; and A1 represents an addition polymerizable functional group.
    Type: Grant
    Filed: September 22, 2009
    Date of Patent: October 23, 2012
    Assignees: Ricoh Company, Ltd., JNC Corporation
    Inventors: Masaki Watanabe, Naohito Shimota, Hiroshi Yamashita, Naohiro Watanabe, Tsuneyasu Nagatomo, Tsuyoshi Sugimoto, Shinichi Wakamatsu, Kenya Itoh, Mikio Yamahiro
  • Patent number: 8178268
    Abstract: A magenta toner, produced by a method including suspending an oily liquid comprising a binder resin and a colorant in an aqueous medium, wherein the colorant comprises a naphthol pigment and a quinacridone pigment, and the quinacridone pigment comprises a pigment having a specific formula.
    Type: Grant
    Filed: September 28, 2009
    Date of Patent: May 15, 2012
    Assignee: Ricoh Company, Limited
    Inventors: Naohiro Watanabe, Shinichi Wakamatsu, Naohito Shimota, Hiroshi Yamashita, Tsuyoshi Sugimoto, Masaki Watanabe, Tsuneyasu Nagatomo
  • Patent number: 8163455
    Abstract: Provided is a toner for image formation, granulated by dispersing, emulsifying, or both dispersing and emulsifying an oil phase containing toner constituting materials in an aqueous medium. The toner constituting materials contain a binder resin, a colorant and a pigment dispersant which is a polyester derivative having an acid value of 28 to 50 mgKOH/g and an amine value of 1 to 50 mgKOH/g, and satisfy the following Expressions 1 and 2, where Expression 1 represents a mass ratio, ? is a glass transition temperature of the binder resin, and ? is a glass transition temperature of a mixture of the binder resin and the pigment dispersant in the ratio of Expression 1. Binder resin:Pigment dispersant=100:5??Expression 1 0° C.?????10° C.
    Type: Grant
    Filed: March 13, 2009
    Date of Patent: April 24, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Naohiro Watanabe, Hiroshi Yamashita, Shinichi Wakamatsu, Tsuyoshi Sugimoto
  • 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
  • Publication number: 20110223530
    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: Application
    Filed: May 20, 2011
    Publication date: September 15, 2011
    Inventors: Ryota Inoue, Shigeru Emoto, Naohiro Watanabe, Masahide Yamada, Akinori Saitoh, Masahiro Ohki, Tsunemi Sugiyama, Shinichi Wakamatsu, Takayuki Yoshii, Eiji Sawamura
  • Patent number: 7989131
    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: September 13, 2006
    Date of Patent: August 2, 2011
    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: 7968265
    Abstract: A toner is provided that includes a release agent, a colorant, a binder resin including a polyester resin, and a fixing auxiliary component including an ester compound of a fatty acid with an alcohol. The fatty acid includes stearic acid and behenic acid in a total amount of 80% by weight or more. The alcohol includes ethylene glycol in an amount of 80% by weight or more. The ester compound has a hydroxyl value of 10 to 100 mgKOH/g.
    Type: Grant
    Filed: February 26, 2009
    Date of Patent: June 28, 2011
    Assignee: Ricoh Company, Limited
    Inventors: Tsuyoshi Sugimoto, Hiroshi Yamashita, Naohiro Watanabe, Shinichi Wakamatsu, Masaki Watanabe
  • Patent number: 7947419
    Abstract: A toner including a binder resin including a polyester resin, a colorant, and a release agent including a polyglycerin ester having a melt viscosity of from 1.0 to 40 mPa·sec at 120° C. and a hydroxyl value of from 0 to 100 mgKOH/g is provided. The polyglycerin ester is an ester of a polyglycerin having an average polymerization degree of from 2 to 10 and an aliphatic acid having 16 to 24 carbon atoms in average.
    Type: Grant
    Filed: October 9, 2008
    Date of Patent: May 24, 2011
    Assignee: Ricoh Company Limited
    Inventors: Tsuyoshi Sugimoto, Hiroshi Yamashita, Naohiro Watanabe, Shinichi Wakamatsu
  • Publication number: 20110076607
    Abstract: A toner including at least one polyester resin serving as a binder resin, a colorant, a releasing agent, and a fixing aid, wherein the fixing aid includes a fatty acid amide-based compound, and the fatty acid amide-based compound is at least one of a fatty acid amide compound having a mono- or higher valent amide bond and a fatty acid amide-based compound having a mono- or higher valent amino group or a hydroxyl group.
    Type: Application
    Filed: May 22, 2009
    Publication date: March 31, 2011
    Inventors: Tsuyoshi Sugimoto, Hiroshi Yamashita, Naohiro Watanabe, Shinichi Wakamatsu, Masaki Watanabe, Satoshi Ogawa, Masana Shiba, Junichi Awamura, Naohito Shimota
  • Patent number: 7820350
    Abstract: A toner containing a colorant, and a binder resin, wherein the toner is prepared by dissolving or dispersing a colorant, a precursor of the binder resin having a site capable of reacting with an active hydrogen group-containing compound, the active hydrogen group-containing compound, in an organic solvent, to prepare a toner constituent mixture liquid, dispersing or emulsifying the toner constituent mixture liquid, in an aqueous medium while subjecting the precursor to a reaction with the active hydrogen group-containing compound, to prepare a toner dispersion, and removing the organic solvent from the toner dispersion; the binder resin contains a modified polyester having an isocyanate-derived binding site; the Sn content in the toner is 800 ppm or less; the content of a metal which is non Sn and derived from a polyesterified catalyst is 10 ppm to 200 ppm; and the content of a metal which is non Sn and derived from an isocyanated catalyst is 10 ppm to 200 ppm.
    Type: Grant
    Filed: March 16, 2007
    Date of Patent: October 26, 2010
    Assignee: Ricoh Company, Ltd.
    Inventors: Masahide Yamada, Shigeru Emoto, Naohiro Watanabe, Masahiro Ohki, Akinori Saitoh, Shinichi Wakamatsu
  • Patent number: 7709174
    Abstract: A toner is provided including a colorant; a first binder resin; and a second binder resin, wherein an amount of the first binder resin and an amount of the second binder resin are phase separated from each other in the toner, and wherein a phase of the first binder resin is partially or completely covered with a phase of the second binder resin; and a method of preparing the toner, and a developer, an image forming method, an image forming apparatus, and a process cartridge using the toner.
    Type: Grant
    Filed: December 15, 2006
    Date of Patent: May 4, 2010
    Assignee: Ricoh Company Limited
    Inventors: Tsuyoshi Sugimoto, Hiroshi Yamashita, Ryota Inoue, Yoshihiro Moriya, Shinichi Wakamatsu, Akihiro Kotsugai
  • Patent number: 7695883
    Abstract: To provide a toner containing an ethyl acetate-soluble polyester component and an ethyl acetate-insoluble polyester component, wherein the toner is granulated in an aqueous medium, the ethyl acetate-insoluble polyester component is obtained by elongating and/or cross-linking a modified polyester resin during granulating and/or after granulating, the modified polyester resin is produced by condensation polymerization of an acid component and at least one type of diol compound selected from aliphatic diol and alicyclic diol in the presence of a catalyst, and the mass average molecular weight of the modified polyester resin is 10,000 to 100,000.
    Type: Grant
    Filed: December 24, 2008
    Date of Patent: April 13, 2010
    Assignee: Ricoh Company, Ltd.
    Inventors: Masahide Yamada, Ryota Inoue, Naohiro Watanabe, Shigeru Emoto, Masahiro Ohki, Akinori Saitoh, Tsunemi Sugiyama, Shinichi Wakamatsu, Toshiki Nanya, Naohito Shimota, Hiroshi Yamada, Junichi Awamura, Tomomi Suzuki, Kazuyuki Hirai, Kazushige Yasumatsu
  • Publication number: 20100081075
    Abstract: A magenta toner, produced by a method including suspending an oily liquid comprising a binder resin and a colorant in an aqueous medium, wherein the colorant comprises a naphthol pigment and a quinacridone pigment, and the quinacridone pigment comprises a pigment having a specific formula.
    Type: Application
    Filed: September 28, 2009
    Publication date: April 1, 2010
    Inventors: Naohiro WATANABE, Shinichi WAKAMATSU, Naohito SHIMOTA, Hiroshi YAMASHITA, Tsuyoshi SUGIMOTO, Masaki WATANABE, Tsuneyasu NAGATOMO
  • Publication number: 20100075243
    Abstract: A toner for electrophotography, including a release agent; a binder resin; a colorant; and an external additive, wherein the binder resin is a polyester resin, and wherein the toner has a loss on heat not greater than 0.40% by weight at 165° C. and a difference between a loss on heat at 200° C. and the loss on heat at 165° C. not greater than 0.50% by weight, and includes a n-paraffin in an amount not less than 3% by weight.
    Type: Application
    Filed: September 22, 2009
    Publication date: March 25, 2010
    Inventors: Naohito SHIMOTA, Naohiro Watanabe, Hiroshi Yamashita, Tsuyoshi Sugimoto, Masaki Watanabe, Satoshi Kojima, Shinichi Wakamatsu, Tsuneyasu Nagatomo