Patents by Inventor Kazuo Murakata

Kazuo Murakata 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).

  • Carrier for electrophotography and developer for electrophotography using the carrier
    Patent number: 6197465
    Abstract: A carrier for electrophotography includes a carrier core material provided with magnetism and a coating layer which coats the surface of the carrier core material and includes a high molecular weight polyethylene resin having a weight average molecular weight of 50,000 or more. An outermost layer containing a magnetic powder having a three-dimensional form of a convex polyhedron is formed on the outermost surface of the coating layer.
    Type: Grant
    Filed: October 25, 1999
    Date of Patent: March 6, 2001
    Assignees: Idemitsu Kosan Co., Ltd., Kyocera Corporation
    Inventors: Shigeo Matsuzaki, Takashi Arakane, Kazuo Murakata, Susumu Kikuchi, Hisashi Mukataka, Yuji Kamiyama
  • Electrophotographic carrier and electrophotographic developer using same
    Patent number: 5968699
    Abstract: Disclosed is an electrophotographic carrier comprising a magnetic carrier core and a coating layer composed of a high molecular weight polyethylene resin with which the carrier core is coated, wherein the coating layer composed of a high molecular weight polyethylene resin includes a layer containing hydrophobic silica, a magnetic powder, and/or a micropowdered resin at least as the outermost layer.
    Type: Grant
    Filed: September 11, 1997
    Date of Patent: October 19, 1999
    Assignees: Idemitsu Kosan Co., Ltd., Kyocera Corporation
    Inventors: Shigeo Matsuzaki, Takashi Arakane, Kazuo Murakata, Susumu Kikuchi
  • Carrier for electrophotography and developing material for electrophotography using same
    Patent number: 5919593
    Abstract: The invention relates to a carrier for electrophotography comprising a carrier core material covered with a polymeric polyolefin-based resin. Such a carrier is used that the carrier core material content accounts for 90% by weight or more of the carrier and he carrier surface has a shape factor S(smoothness) satisfying the relation, 100.ltoreq.S<130, when represented by the following equation (I):S=(L.sup.2 /A).times.(1/4.pi.).times.100 (I),(where L designates an average value of an outer periphery of a projection of the carrier and A designates an average value of a projected area of the carrier).
    Type: Grant
    Filed: January 7, 1998
    Date of Patent: July 6, 1999
    Assignee: Idemitsu Kosan Co., Ltd.
    Inventors: Yusuke Karima, Kazuo Murakata, Hiroshi Matsuo