Patents by Inventor Jiro Yamashiro

Jiro Yamashiro 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: 5362592
    Abstract: A decolorizable toner including a resin binder, a near infrared ray-absorbing dye, a decolorizing agent and a light fastness stabilizer, and a process for preparing the decolorizable toner, which includes the steps of mixing the near infrared ray-absorbing dye and the light fastness stabilizer with the resin binder, and then mixing the decolorizing agent therewith. The decolorizable toner has excellent light stability during its production or storage and excellent decolorizing property.
    Type: Grant
    Filed: November 13, 1992
    Date of Patent: November 8, 1994
    Assignees: Showa Denko K.K., Bando Chemical Industries, Ltd.
    Inventors: Katsumi Murofushi, Yoshikazu Hosoda, Toshio Kaji, Yuki Abe, Kiyotaka Yamaguchi, Takayuki Yoshida, Jiro Yamashiro, Toshio Arai, Takayuki Nagase, Harushi Nagami
  • Patent number: 5328795
    Abstract: There is disclosed a method of producing a toner particles for use in electrophotography which comprises: suspending a radical polymerizable monomer which contains a colorant and a charge controlling agent therein in an aqueous phase; suspension polymerizing the monomer to provide spherical polymer particles of 1-30 .mu.m in diameter; treating the suspension containing the polymer particles with a continuous, wet type, agitation mill, to deform the polymer particles.A further method of producing toner particles is disclosed which comprises: producing spherical polymer particles by suspension polymerization of a monomer; making finely divided triboelectric or electroconductive particles or both onto the surface of the polymer particles; and then mechanically pressing the polymer particles to deform the polymer particles as well as to fix the particles on the surface of the polymer particles.
    Type: Grant
    Filed: March 29, 1990
    Date of Patent: July 12, 1994
    Assignee: Bando Chemical Industries, Ltd.
    Inventors: Jiro Yamashiro, Harushi Nagami, Takashi Miki, Mitsuhiro Uchino
  • Patent number: 4904560
    Abstract: A process for producing toners for use in electrophotography which comprises: stirring a mixture of a radical polymerizable liquid monomer and carbon black in the presence of a peroxide polymerization initiator, thereby to disperse the carbon black uniformly and minutely in the monomer; adding an azobisnitrile polymerization initiator to the resultant monomer composition; suspension polymerizing the monomer in an aqueous medium; and recovering and drying the resultant spherical polymer particles.In a preferred process, the suspension polymerization is carried out in an aqueous medium which contains polyvinyl alcohol as a suspending agent, and after the polymerization, the polyvinyl alcohol remaining on the polymer particles is saponified or nitrated to produce a toner with a higher quality.
    Type: Grant
    Filed: June 28, 1988
    Date of Patent: February 27, 1990
    Assignee: Bando Chemical Industries, Ltd.
    Inventors: Jiro Yamashiro, Takashi Miki