Patents by Inventor Koji Shimokusa

Koji Shimokusa 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: 10031432
    Abstract: According to the present invention, there are provided a process for producing a toner for development of electrostatic images which is capable of suppressing desorption and exposure of a releasing agent therein, and excellent in fusing property, suppression of toner cloud and durability; a process for producing a dispersion, and a kit for producing the dispersion.
    Type: Grant
    Filed: June 13, 2014
    Date of Patent: July 24, 2018
    Assignee: KAO CORPORATION
    Inventors: Hiroshi Mizuhata, Koji Shimokusa
  • Patent number: 9529290
    Abstract: The present invention relates to a process for producing a toner for electrophotography which is capable of suppressing liberation of a wax from a resin binder and exposure of the wax to a surface of respective toner particles in the step of obtaining fused particles upon production of the toner, and reducing a content of fine powders in the toner, and which is characterized by an excellent low-temperature fusing property and an excellent anti-high-temperature offset property.
    Type: Grant
    Filed: October 4, 2013
    Date of Patent: December 27, 2016
    Assignee: KAO CORPORATION
    Inventors: Yasuhiro Shidahara, Manato Ikeda, Hiroshi Mizuhata, Koji Shimokusa
  • Publication number: 20160179021
    Abstract: According to the present invention, there are provided a process for producing a toner for development of electrostatic images which is capable of suppressing desorption and exposure of a releasing agent therein, and excellent in fusing property, suppression of toner cloud and durability; a process for producing a dispersion, and a kit for producing the dispersion.
    Type: Application
    Filed: June 13, 2014
    Publication date: June 23, 2016
    Applicant: KAO CORPORATION
    Inventors: Hiroshi MIZUHATA, Koji SHIMOKUSA
  • Publication number: 20150277250
    Abstract: The present invention relates to a process for producing a toner for electrophotography which is capable of suppressing liberation of a wax from a resin binder and exposure of the wax to a surface of respective toner particles in the step of obtaining fused particles upon production of the toner, and reducing a content of fine powders in the toner, and which is characterized by an excellent low-temperature fusing property and an excellent anti-high-temperature offset property.
    Type: Application
    Filed: October 4, 2013
    Publication date: October 1, 2015
    Applicant: KAO CORPORATION
    Inventors: Yasuhiro Shidahara, Manato Ikeda, Hiroshi Mizuhata, Koji Shimokusa
  • Patent number: 9005868
    Abstract: The present invention relates to a process for producing a toner for electrophotography which includes the step of fusing aggregated particles containing resin particles (A) and releasing agent particles in an aqueous mixed solution containing the aggregated particles and an anionic surfactant having a polyalkylene glycol moiety with an average molar number of addition of an alkylene oxide having 2 to 3 carbon atoms of from 5 to 100 after and/or while adjusting a pH value of the aqueous mixed solution to 2.0 to 6.0 as measured at 25° C., and a toner for electrophotography obtained by the process.
    Type: Grant
    Filed: December 9, 2011
    Date of Patent: April 14, 2015
    Assignee: Kao Corporation
    Inventors: Shoichi Murata, Takayuki Ikenaga, Takashi Okuno, Hiroshi Mizuhata, Keishi Yokota, Koji Shimokusa, Koji Kameyama
  • Patent number: 8940468
    Abstract: Disclosed is a process for production of a decolorable toner, including: aggregating dispersed fine particles of a color material comprising at least a color-forming compound, a color-developing agent and a decoloring agent with dispersed fine particles comprising at least a binder resin comprising a polyester resin to form aggregates in an aqueous medium, adding a reactive polymer having an oxazoline group in to the aqueous medium, and fusing the aggregates in the aqueous medium. As a result, it becomes possible to produce a decolorable toner which suppresses the generation of fine powder due to the release of fine particles of an erasable color material from the toner.
    Type: Grant
    Filed: June 29, 2012
    Date of Patent: January 27, 2015
    Assignee: Toshiba Tec Kabushiki Kaisha
    Inventors: Takayasu Aoki, Takafumi Hara, Tsuyoshi Itou, Masahiro Ikuta, Motonari Udo, Koji Shimokusa, Hiroshi Mizuhata
  • Publication number: 20130295499
    Abstract: The present invention relates to a process for producing a toner for electrophotography which includes the step of fusing aggregated particles containing resin particles (A) and releasing agent particles in an aqueous mixed solution containing the aggregated particles and an anionic surfactant having a polyalkylene glycol moiety with an average molar number of addition of an alkylene oxide having 2 to 3 carbon atoms of from 5 to 100 after and/or while adjusting a pH value of the aqueous mixed solution to 2.0 to 6.0 as measured at 25° C., and a toner for electrophotography obtained by the process.
    Type: Application
    Filed: December 9, 2011
    Publication date: November 7, 2013
    Applicant: KAO CORPORATION
    Inventors: Shoichi Murata, Takayuki Ikenaga, Takashi Okuno, Hiroshi Mizuhata, Keishi Yokota, Koji Shimokusa, Koji Kameyama
  • Publication number: 20130011777
    Abstract: Disclosed is a process for production of a decolorable toner, including: aggregating dispersed fine particles of a color material comprising at least a color-forming compound, a color-developing agent and a decoloring agent with dispersed fine particles comprising at least a binder resin comprising a polyester resin to form aggregates in an aqueous medium, adding a reactive polymer having an oxazoline group in to the aqueous medium, and fusing the aggregates in the aqueous medium. As a result, it becomes possible to produce a decolorable toner which suppresses the generation of fine powder due to the release of fine particles of an erasable color material from the toner.
    Type: Application
    Filed: June 29, 2012
    Publication date: January 10, 2013
    Applicant: TOSHIBA TEC KABUSHIKI KAISHA
    Inventors: Takayasu Aoki, Takafumi Hara, Tsuyoshi Itou, Masahiro Ikuta, Motonari Udo, Koji Shimokusa, Hiroshi Mizuhata
  • Patent number: 7723002
    Abstract: A toner for electrostatic image development, comprising a resin binder comprising a crystalline polyester; a releasing agent comprising a wax having a melting point of from 60 to 85° C. and a penetration at 25° C. of from 4 to 10; and a colorant. The toner for electrostatic image development can be used, for instance, for the development of a latent image formed in electrophotography, electrostatic recording method, electrostatic printing method or the like.
    Type: Grant
    Filed: September 23, 2004
    Date of Patent: May 25, 2010
    Assignee: Kao Corporation
    Inventors: Koji Shimokusa, Shinichi Sata, Yasuhiro Hidaka
  • Patent number: 7625684
    Abstract: A toner for electrophotography containing a resin binder and a colorant, wherein the resin binder contains a polyester in an amount higher than 50% by weight of the resin binder, wherein the polyester is obtained by polycondensing an alcohol component containing 60% by mol or more of an aliphatic diol having 3 to 10 carbon atoms and a carboxylic acid component comprising 80% by mol or more of an aromatic dicarboxylic acid compound, the polyester having an index of crystallinity of from 0.6 to 1.5, and a glass transition temperature of 0° C. or more and less than 40° C. The toner for electrophotography of the present invention can be used for, for example, developing electrostatic latent images formed in electrophotography, electrostatic recording method, electrostatic printing method, or the like.
    Type: Grant
    Filed: July 5, 2005
    Date of Patent: December 1, 2009
    Assignee: Kao Corporation
    Inventors: Nobumichi Kamiyoshi, Koji Shimokusa, Takashi Yamaguchi, Shinichi Sata
  • Patent number: 7579129
    Abstract: The present invention relates to a process for preparing a toner for electrophotography comprising a crystalline polyester and a colorant, wherein the colorant is added in at least one of the neutralizing step, the emulsifying step, and the aggregating step and a process for preparing a toner for electrophotography comprising a crystalline polyester and a colorant, wherein the colorant is added in at least one of the neutralizing and emulsifying step, and the aggregating step. The toner obtained according to the process of the present invention can be suitably used, for example, in development of a latent image formed in electrophotography, electrostatic recording method, electrostatic printing method, or the like.
    Type: Grant
    Filed: May 25, 2005
    Date of Patent: August 25, 2009
    Assignee: Kao Corporation
    Inventors: Nobumichi Kamiyoshi, Koji Shimokusa, Hiroyuki Kawaji
  • Publication number: 20060029875
    Abstract: A toner for electrophotography containing a resin binder and a colorant, wherein the resin binder contains a polyester in an amount higher than 50% by weight of the resin binder, wherein the polyester is obtained by polycondensing an alcohol component containing 60% by mol or more of an aliphatic diol having 3 to 10 carbon atoms and a carboxylic acid component comprising 80% by mol or more of an aromatic dicarboxylic acid compound, the polyester having an index of crystallinity of from 0.6 to 1.5, and a glass transition temperature of 0° C. or more and less than 40° C. The toner for electrophotography of the present invention can be used for, for example, developing electrostatic latent images formed in electrophotography, electrostatic recording method, electrostatic printing method, or the like.
    Type: Application
    Filed: July 5, 2005
    Publication date: February 9, 2006
    Applicant: KAO CORPORATION
    Inventors: Nobumichi Kamiyoshi, Koji Shimokusa, Takashi Yamaguchi, Shinichi Sata
  • Publication number: 20050271965
    Abstract: The present invention relates to a process for preparing a toner for electrophotography comprising a crystalline polyester and a colorant, wherein the colorant is added in at least one of the neutralizing step, the emulsifying step, and the aggregating step and a process for preparing a toner for electrophotography comprising a crystalline polyester and a colorant, wherein the colorant is added in at least one of the neutralizing and emulsifying step, and the aggregating step. The toner obtained according to the process of the present invention can be suitably used, for example, in development of a latent image formed in electrophotography, electrostatic recording method, electrostatic printing method, or the like.
    Type: Application
    Filed: May 25, 2005
    Publication date: December 8, 2005
    Applicant: KAO CORPORATION
    Inventors: Nobumichi Kamiyoshi, Koji Shimokusa, Hiroyuki Kawaji
  • Publication number: 20050095523
    Abstract: A toner for electrostatic image development, comprising a resin binder comprising a crystalline polyester; a releasing agent comprising a wax having a melting point of from 60 to 85° C. and a penetration at 25° C. of from 4 to 10; and a colorant. The toner for electrostatic image development can be used, for instance, for the development of a latent image formed in electrophotography, electrostatic recording method, electrostatic printing method or the like.
    Type: Application
    Filed: September 23, 2004
    Publication date: May 5, 2005
    Applicant: KAO CORPORATION
    Inventors: Koji Shimokusa, Shinichi Sata, Yasuhiro Hidaka
  • Patent number: 6660442
    Abstract: A nonmagnetic black toner for reversal development comprising a resin binder; and a black colorant comprising a composite oxide of two or more metals, the composite oxide having an oil absorption per unit area of 0.07 ml/m2 or less. The nonmagnetic black toner can be suitably used for the development of a latent image formed in electrophotography, electrostatic recording method, electrostatic printing method or the like.
    Type: Grant
    Filed: April 3, 2002
    Date of Patent: December 9, 2003
    Assignee: Kao Corporation
    Inventors: Shinichi Sata, Akihiro Eida, Koji Shimokusa, Jun Shimizu
  • Publication number: 20020177059
    Abstract: A nonmagnetic black toner for reversal development comprising a resin binder; and a black colorant comprising a composite oxide of two or more metals, the composite oxide having an oil absorption per unit area of 0.07 ml/m2 or less. The nonmagnetic black toner can be suitably used for the development of a latent image formed in electrophotography, electrostatic recording method, electrostatic printing method or the like.
    Type: Application
    Filed: April 3, 2002
    Publication date: November 28, 2002
    Inventors: Shinichi Sata, Akihiro Eida, Koji Shimokusa, Jun Shimizu
  • Patent number: 5655202
    Abstract: A fixing apparatus for fixing visible images formed on a recording medium has a heat roller having a heating member in the inner portion of the heat roller, and a flat plate-like elastic member forming a nip in contact with the heat roller and capable of exerting a pressure at the nip portion by an elastic stress, the recording medium being fed into the nip portion. According to the fixing apparatus and the fixing method using this apparatus, since a pressure roller is not necessary, the system can be simplified, which leads to miniaturization of the overall fixing apparatus, reduction of overall weight and cost reduction.
    Type: Grant
    Filed: February 20, 1996
    Date of Patent: August 5, 1997
    Assignee: Kao Corporation
    Inventors: Yoshio Yoshimura, Ikuo Takahashi, Shuji Watanabe, Koji Akiyama, Koji Shimokusa
  • Patent number: 5567567
    Abstract: The encapsulated toner for heat-and-pressure fixing of the present invention having a heat-fusible core material containing at least a thermoplastic resin and a shell formed thereon so as to cover the surface of the core material is produced by the method having the steps of (a) dispersing in a shell-forming resin an additive selected from the group consisting of conductive materials, charge control agents, wax components, color pigments, particulate magnetic materials, and mixtures thereof to give a shell-forming resin containing the additive; (b) dissolving the shell-forming resin containing the additive in a mixture containing a core material-constituting monomer; (c) dispersing the mixture obtained in step (b) in an aqueous dispersant, and localizing the shell-forming resin containing the additive on the surface of droplets of the core-constituting material to give a polymerizable composition; and (d) polymerizing the polymerizable composition obtained in step (c) by in situ polymerization to form the cor
    Type: Grant
    Filed: November 2, 1994
    Date of Patent: October 22, 1996
    Assignee: Kao Corporation
    Inventors: Koji Akiyama, Takashi Yamaguchi, Koji Kameyama, Koji Shimokusa
  • Patent number: 5565293
    Abstract: The encapsulated toner for heat-and-pressure fixing of the present invention has a heat-fusible core material containing at least a thermoplastic resin and a coloring agent and a shell formed thereon so as to cover the surface of the core material. Moreover, the encapsulated toner has the following properties: 1) The glass transition temperature ascribed to the thermoplastic resin used as a main component of the heat-fusible core material is 10.degree. C. to 50.degree. C.; 2) A minimum load required for 58 compression of a particle size of the encapsulated toner is from 5 to 50 mgf, and a minimum load required for 10% compression of a particle size of the encapsulated toner is from 10 to 100 mgf, when a compressive variation of one toner particle is measured by a micro compression testing machine under the given conditions; and 3) The difference in cohesiveness before and after keeping the toner standing at 50.degree. C.
    Type: Grant
    Filed: March 9, 1995
    Date of Patent: October 15, 1996
    Assignee: KAO Corporation
    Inventors: Koji Akiyama, Koji Kameyama, Koji Shimokusa, Kuniyasu Kawabe
  • Patent number: 5330870
    Abstract: An electrophotographic developer composition for flash fusing containing at least a binder resin based on a polyester resin and a colorant, the polyester resin being formed between an acid component, not less than 80 mol % of the acid component being phthalic acid series dicarboxylic acid and an alcohol component, not less than 80 mol % of the alcohol component being bisphenol A alkylene oxide adduct, the polyester resin having an acid value of not more than 10.0 KOH mg/g, a softening temperature of not less than 95.0.degree. C. and not more than 125.0.degree. C. as determined using a flow tester of the "koka-shiki" type and a glass transition temperature of not less than 50.0.degree. C. and not more than 80.0.degree. C. as determined by DSC, whereby substantially no odor is produced upon flash fusing.
    Type: Grant
    Filed: August 31, 1992
    Date of Patent: July 19, 1994
    Assignee: Kao Corporation
    Inventors: Shingo Tanaka, Koji Nishibuchi, Koji Shimokusa, Tetsuya Ueno