Patents by Inventor Kiyoko Tsuchiya

Kiyoko Tsuchiya 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: 5338638
    Abstract: A toner for developing an electrostatic image is provided as a pulverized mixture including a binder resin and a colorant. The binder resin is characterized by a molecular weight distribution on a GPC chromatogram of its tetrahydrofuran (THF)-soluble resin content including at least 15% and below 35% of a resin component in a molecular weight region of at most 5000 and at least 3 wt. % of a resin component in a molecular weight region of at least 5.times.10.sup.6 and showing a main peak in a molecular weight region of 5000 to 10.sup.5. The binder resin also has an acid value of 2-100 mg KOH/g. The THF-soluble resin component in the molecular weight region of at least 5.times.10.sup.6 is enriched during a melt-kneading step during the toner production.
    Type: Grant
    Filed: November 26, 1991
    Date of Patent: August 16, 1994
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kiyoko Tsuchiya, Koichi Tomiyama, Masayoshi Kato, Tsutomu Kukimoto, Hiroshi Yusa
  • Patent number: 5319424
    Abstract: A developer for developing an electrostatic image has a toner, fine resin particles with a surface shape sphericity .psi. of from 0.90 to 0.50, and fine inorganic particles.
    Type: Grant
    Filed: September 10, 1993
    Date of Patent: June 7, 1994
    Assignee: Canon Kabushiki Kaisha
    Inventors: Koichi Tomiyama, Masayoshi Kato, Tsutomu Kukimoto, Hiroshi Yusa, Kiyoko Tsuchiya
  • Patent number: 5298354
    Abstract: A toner for developing an electrostatic image, comprises a binder resin and a colorant. Such binder resin contains a THF-insoluble component in an amount of less than 10 wt. % based on the binder resin, and, in the molecular weight distribution measured by GPC (gel permeation chromatography) of a THF-soluble component, has a weight average molecular weight/number average molecular weight (Mw/Mn) of .gtoreq.18, a molecular weight peak MA in the region of a molecular weight of from 3,000 to 20,000, a molecular weight peak MB in the region of a molecular weight of from 380,000 to 1,000,000, a molecular weight minimum Md in the region of a molecular weight of from 20,000 to 380,000, provided that MB/MA is in the range of from 30 to 150, and a molecular weight distribution curve area ratio SA:SB:Sd of 1:0.3 to 0.8:0.35 to 0.8.
    Type: Grant
    Filed: March 23, 1992
    Date of Patent: March 29, 1994
    Assignee: Canon Kabushiki Kaisha
    Inventors: Satoshi Matsunaga, Takashige Kasuya, Hiroaki Kawakami, Kiyoko Tsuchiya, Yusuke Karami, Shinji Doi
  • Patent number: 5270143
    Abstract: A developer for developing an electrostatic image has a toner, fine resin particles with a surface shape sphericity .psi. of from 0.90 to 0.50, and fine inorganic particles.
    Type: Grant
    Filed: October 28, 1991
    Date of Patent: December 14, 1993
    Assignee: Canon Kabushiki Kaisha
    Inventors: Koichi Tomiyama, Masayoshi Kato, Tsutomu Kukimoto, Hiroshi Yusa, Kiyoko Tsuchiya
  • Patent number: 5215845
    Abstract: An electrostatic image supporting member which supports an electrostatic image and a toner carrying member for conveying a magnetic toner are disposed in a development section with a specified gap therebetween. The toner carrying member has a base whose surface has an average surface roughness (Ra) of 1.0 to 3.0 .mu.m. A resin coating containing electrically conductive fine particles is formed on the base surface at a density of 4 to 12 g per 1 m.sup.2. The outer layer of the coating has an Ra from 0.8 to 3.0 .mu.m. The toner carrying member carries an electrically insulating magnetic toner containing at least a binder resin and a magnetic component, and satisfying the conditions of a volumetric average particle size of 4.5 to 8 .mu.m, a BET specific surface area of 1.8 to 3.5 m.sup.2 /g, a charge amount of -20 to -35 .mu.c/g, a loose-state apparent density of 0.40 to 0.52 g/cm.sup.3, and a true specific gravity of 1.45 to 1.8.
    Type: Grant
    Filed: October 21, 1991
    Date of Patent: June 1, 1993
    Assignee: Canon Kabushiki Kaisha
    Inventors: Hiroshi Yusa, Kohichi Tomiyama, Masayoshi Kato, Tsutomu Kukimoto, Kiyoko Tsuchiya
  • Patent number: 5135833
    Abstract: A toner for developing an electrostatic image, comprises a binder resin and a colorant. Such binder resin contains a THF-insoluble matter in an amount of less than 10 wt. % based on the binder resin, and, in the molecular weight distribution measured by GPC (gel permeation chromatography) of a THF-soluble matter, has a weight average molecular weight/number average molecular weight (Mw/Mn) of .gtoreq.18, a molecular weight peak MA in the region of a molecular weight of from 3,000 to 20,000, a molecular weight peak MB in the region of a molecular weight of from 380,000 to 1,000,000, a molecular weight minimum Md in the region of a molecular weight of from 20,000 to 380,000, provided that MB/MA is in the range of from 30 to 150, and a molecular weight distribution curve area ratio SA:SB:Sd of 1:0.3 to 0.8:0.35 to 0.8.
    Type: Grant
    Filed: January 18, 1991
    Date of Patent: August 4, 1992
    Assignee: Canon Kabushiki Kaisha
    Inventors: Satoshi Matsunaga, Takashige Kasuya, Hiroaki Kawakami, Kiyoko Tsuchiya, Yusuke Karami, Shinji Doi