Patents by Inventor Shuichi Aita

Shuichi Aita 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: 5219947
    Abstract: A toner for developing electrostatic latent images with a good combination of fixability, anti-offset characteristic, anti-sticking characteristic and pulverizability is provided as a composition comprising a colorant or magnetic material and a binder resin. The binder resin has 0.1 to 60 wt. % of a chloroform-insoluble or a THF (tetrahydrofuran)insoluble and a THF-soluble, the THF-soluble providing a molecular weight distribution in the chromatogram of GPC (gel permeation chromatography) thereof such that there are a main peak in the molecular weight range of 1,000 to 25,000 and a sub-peak or shoulder in the molecular weight range of 2,000 to 150,000. The binder resin may suitably be obtained through two polymerization steps including a solution polymerization step and a suspension polymerization step.
    Type: Grant
    Filed: April 23, 1990
    Date of Patent: June 15, 1993
    Assignee: Canon Kabushiki Kaisha
    Inventors: Satoshi Yasuda, Kiichiro Sakashita, Yasuo Mitsuhashi, Seiichi Takagi, Shuichi Aita, Yoshinobu Nagai, Toshiaki Nakahara
  • Patent number: 4966829
    Abstract: A toner for developing electrostatic latent images with a good combination of fixability, anti-offset characteristic, anti-sticking characteristic and pulverizability is provided as a composition comprising a colorant or magnetic material and a binder resin. The binder resin has 0.1 to 60 wt. % of a chloroform-insoluble or a THF (tetrahydrofuran)-insoluble and a THF-soluble, the THF-soluble providing a molecular weight distribution in the chromatogram of GPC (gel permeation chromatography) thereof such that there are a main peak in the molecular weight range of 1,000 to 25,000 and a sub-peak or shoulder in the molecular weight range of 2,000 to 150,000. The binder resin may suitably be obtained through two polymerization steps including a solution polymerization step and a suspension polymerization step.
    Type: Grant
    Filed: November 23, 1988
    Date of Patent: October 30, 1990
    Assignee: Canon Kabushiki Kaisha
    Inventors: Satoshi Yasuda, Kiichiro Sakashita, Yasuo Mitsuhashi, Seiichi Takagi, Shuichi Aita, Yoshinobu Nagai, Toshiaki Nakahara
  • Patent number: 4868085
    Abstract: A developer for developing electrostatic latent images comprises a toner comprising a colorant and a binder resin composed of a non-linear, low melting point polyester resin, inorganic fine powder A having BET specific surface area of 0.5-30 m.sup.2 /g and inorganic fine powder B having BET specific surface area of 40-400 m.sup.2 /g measured by means of nitrogen adsorption.
    Type: Grant
    Filed: March 22, 1988
    Date of Patent: September 19, 1989
    Assignee: Canon Kabushiki Kaisha
    Inventor: Shuichi Aita