Patents Assigned to Daimippon Ink and Chemicals, Inc.
  • Patent number: 6183924
    Abstract: The present invention provides a novel developer comprising a spherically particulate toner having a volume-average particle diameter of from about 1 to 6 &mgr;m for use in the development of electrostatic image in electrophotographic copying machines or printers having a colorant content of from 8 to 20% by weight, if the colorant is carbon black, or from 3 to 20% by weight, if the colorant is an organic pigment, based on the sum of the weight of binder resin and colorant and a resin-coated carrier having a volume-average particle diameter of from 20 to 150 &mgr;m. The present invention also provides a suitable polymerization or emulsification process for the preparation of a particulate toner to be incorporated in the developer. The use of the electrostatic image developer makes it possible to not only improve the quality of images provided by copying machines or printers but also realize drastic reduction of the amount of toner to be consumed per sheet of printing paper.
    Type: Grant
    Filed: February 24, 1999
    Date of Patent: February 6, 2001
    Assignee: Daimippon Ink and Chemicals, Inc.
    Inventors: Minoru Nomura, Takashi Ito, Hitoshi Takayanagi, Kazuo Itoya