Patents by Inventor Kazuhiro Hirama

Kazuhiro Hirama 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).

  • Developer for electrostatic latent image
    Patent number: 6399264
    Abstract: An electrostatic developer comprising a mixture of (1) toner components containing image-forming particles, (2) positively charged particles, (3) negatively charged particles, and (4) a lubricant.
    Type: Grant
    Filed: October 25, 2000
    Date of Patent: June 4, 2002
    Assignee: Mitsubishi Chemical America, Inc.
    Inventors: Kenzo Ogata, Kazuhiro Hirama, Shinichi Saiki
  • Electrostatic toner composition to enhance copy quality by rejection of ghosting and method of manufacturing same
    Patent number: 5981131
    Abstract: An electrostatic developer comprising a mixture of (1) a toner component containing image-forming particles, and (2) particles obtained by subjecting inorganic oxide or organic particles to a hydrophobic treatment with a dimethyl cyclopolysiloxane.
    Type: Grant
    Filed: July 27, 1998
    Date of Patent: November 9, 1999
    Assignee: Mitsubishi Chemical America, Inc.
    Inventors: Kazuhiro Hirama, Kenichi Nakazato, Kenzo Ogata, Kenichi Asajima, Shaw-Ping Chang
  • Toner for flash fixation
    Patent number: 5501931
    Abstract: Disclosed is a toner for flash fixation which comprises: (i) a resin containing (a) a low molecular weight compound having the peak of molecular weight in 3,000 to 60,000 by gel permeation chromatography (GPC) and (b) a high molecular weight compound having the peak or shoulder of molecular weight in 80,000 to 1,000,000 by GPC, with the weight ratio of the low molecular weight to the high molecular weight compound in the range of 97 to 60/3 to 40 and (ii) a coloring material or a toner for flash fixation which comprises (i) a resin containing (a) a low molecular weight compound having the peak of molecular weight (Lp) in 3,000 to 60,000 by GPC, (b) a middle molecular weight compound having the peak of molecular weight (Mp) in 5,000 to 100,000 by GPC and (c) a high molecular weight compound having the peak of molecular weight (Hp) in 80,000 to 1,000,000 by GPC, with the condition of Lp<Mp<Hp and (ii) a coloring material, and a method for fixing a toner by flash fixation using these.
    Type: Grant
    Filed: August 18, 1994
    Date of Patent: March 26, 1996
    Assignee: Mitsubishi Kasei Corporation
    Inventors: Kazuhiro Hirama, Mikio Uno
  • Electrostatic image-developing toner and developer
    Patent number: 5320924
    Abstract: Disclosed herein are an electrostatic image-developing toner comprising a binder resin, a quaternary ammonium salt and an acidic carbon black as colorant, and an electrostatic image developer containing the same.
    Type: Grant
    Filed: April 28, 1992
    Date of Patent: June 14, 1994
    Assignee: Mitsubishi Kasei Corporation
    Inventors: Takashi Shintaku, Kazuhiro Hirama, Masami Tsurumori