Patents by Inventor Yojiro Hotta

Yojiro Hotta 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).

  • Publication number: 20030129517
    Abstract: A toner characterized by improved fixing performances with no or minimum oil application is formed of: (i) a binder resin, (ii) a colorant, (iii) a hydrocarbon wax, (iv) a resin composition formed by copolymerization of a styrenic monomer together with at least one of nitrogen-containing vinyl monomers, carboxyl group-containing monomers, hydroxyl group-containing monomers and (meth)acrylate ester monomers, in the presence of a hydrocarbon unit; and (v) an organometallic compound. The binder resin (i) comprises a polyester component in a proportion of at least 60 wt. % of the binder resin. The toner has a GPC molecular weight distribution including a weight-average molecular weight (Mw) of at least 4.0×104 an a ratio Mw/Mn of at least 50 between the Mw and a number-average molecular weight (Mn).
    Type: Application
    Filed: September 4, 2002
    Publication date: July 10, 2003
    Inventors: Yojiro Hotta, Wakashi Iida, Tetsuya Ida, Takayuki Itakura, Nozomu Komatsu
  • Patent number: 6586147
    Abstract: A toner, particularly a color toner suitable for full-color image formation through a substantially oil-less heat-pressure fixing device, is formed from at least a binder resin, a colorant and a wax. The toner has viscoelasticity including: a storage modulus at 80° C. (G′80) in a range of 1×106-1×1010 dN/m2, storage moduli at temperatures of 120-180° C. (G′120-180) in a range of 5×103-1×106 dN/m2, and loss tangents (tan &dgr;=G″/G′ as a ratio between G″ (loss modulus) and G′ (storage molecules)) including a loss tangent at 180° C. (tan &dgr;180) and a minimum of loss tangents over a temperature range of 120-180 ° C. (tan &dgr;min) satisfying 1≦tan &dgr;180/tan &dgr;min. The toner further exhibits a thermal behavior providing a heat-absorption curve according to differential scanning calorimetry (DSC) showing a maximum heat-absorption peak temperature in a range of 50-110° C. in a temperature range of 30-200° C.
    Type: Grant
    Filed: July 9, 2001
    Date of Patent: July 1, 2003
    Assignee: Canon Kabushiki Kaisha
    Inventors: Wakashi Iida, Takaaki Kohtaki, Nobuyoshi Sugawara, Takayuki Itakura, Yojiro Hotta
  • Patent number: 6528222
    Abstract: A toner, particularly a color toner suitable for full-color image formation through a substantially oil-less heat-pressure fixing device, is formed from at least a binder resin, a colorant and a wax. The binder resin comprises a polyester-based resin selected from the group consisting of (a) a polyester resin, (b) a hybrid resin having a polyester unit and a vinyl polymer unit, and (c) a mixture of these resins. The wax is characterized by including a structural unit including an OH group, an amide, or an ester group at a specific position.
    Type: Grant
    Filed: July 9, 2001
    Date of Patent: March 4, 2003
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takaaki Kohtaki, Wakashi Iida, Nobuyoshi Sugahara, Takayuki Itakura, Yojiro Hotta
  • Publication number: 20020072005
    Abstract: A toner, particularly a color toner suitable for full-color image formation through a substantially oil-less heat-pressure fixing device, is formed from at least a binder resin, a colorant and a wax. The binder resin comprises a polyester-based resin selected from the group consisting of (a) a polyester resin, (b) a hybrid resin having a polyester unit and a vinyl polymer unit, and (c) a mixture of these resins. The wax is characterized by including a structural unit including an OH group, an amide, or an ester group at a specific position.
    Type: Application
    Filed: July 9, 2001
    Publication date: June 13, 2002
    Inventors: Takaaki Kohtaki, Wakashi Iida, Nobuyoshi Sugahara, Takayuki Itakura, Yojiro Hotta
  • Publication number: 20020051924
    Abstract: A toner, particularly a color toner suitable for full-color image formation through a substantially oil-less heat-pressure fixing device, is formed from at least a binder resin, a colorant and a wax. The toner has viscoelasticity including: a storage modulus at 80° C. (G′80) in a range of 1×106-1×1010 dN/m2, storage moduli at temperatures of 120-180 ° C. (G′120-180) in a range of 5×103-1×106 dN/m2, and loss tangents (tan &dgr;=G″/G′ as a ratio between G″ (loss modulus) and G′ (storage molecules)) including a loss tangent at 180° C. (tan &dgr;180) and a minimum of loss tangents over a temperature range of 120-180 ° C. (tan &dgr;min) satisfying 1≦tan &dgr;180/tan &dgr;min. The toner further exhibits a thermal behavior providing a heat-absorption curve according to differential scanning calorimetry (DSC) showing a maximum heat-absorption peak temperature in a range of 50-110 ° C. in a temperature range of 30-200° C.
    Type: Application
    Filed: July 9, 2001
    Publication date: May 2, 2002
    Inventors: Wakashi Iida, Takaaki Kohtaki, Nobuyoshi Sugahara, Takayuki Itakura, Yojiro Hotta