Patents by Inventor Mitutaka Arai

Mitutaka Arai 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: 4883734
    Abstract: Disclosed are a toner for development of electrostatic image, comprising as the main component a resin obtained by allowing a polymer containing a polymer component with low molecular weight and a polymer component with high molecular weight, at least the polymer component with low molecular weight containing a carboxylic acid component, to react with a polyvalent metal compound, and a method of fixing a toner image employing the toner described above.According to the present invention, there can be provided a toner for development of electrostatic image which has more improved fixability without lowering the anti-off-set property already improved, and also which can be prepared with good reproducibility without causing gelation to occur although the metal compound may be formulated therein, and can be improved in fixability without making charging characteristics unstable and at the same time without bringing about lowering in anti-off-set property, and thus an excellent toner image can be fixed.
    Type: Grant
    Filed: March 1, 1988
    Date of Patent: November 28, 1989
    Assignees: Konica Corporation, Sekisui Kagaku Kogyo Kabushiki
    Inventors: Satoru Ikeuchi, Mitutaka Arai, Yuki Okuyama, Hideki Yuri, Tomoo Shiohara, Yasuhiko Oyama
  • Patent number: 4882258
    Abstract: There are disclosed a toner for development of an electrostatic image which comprises containing (a) a mixture of a lower molecular weight polymer component and a higher molecular weight polymer component, and said lower molecular polymer component is a resin obtained by reacting a polymer containing a carboxylic acid component with a polyvalent metal compound to form cross-linking through a metal atom and (b) offset preventive agent; and also an electrostatic latent image developer which comprises (A) toner particles mainly comprising a resin obtained by reacting a carboxy group existing in a polymer component with a polyvalent metal compound and (B) resin coated-carrier particles coated with a fluorine-containing resin on a surface of a magnetic particle or inorganic fine particles.
    Type: Grant
    Filed: February 29, 1988
    Date of Patent: November 21, 1989
    Assignee: Konica Corporation
    Inventors: Satoru Ikeuchi, Mitutaka Arai, Yuki Okuyama, Akitoshi Matsubara
  • Patent number: 4464279
    Abstract: Magnetic recording medium having a non-magnetic support carrying a magnetic layer, the layer comprising a ferromagnetic powder, a binder, and a Nitrogen containing compound, which is able to complex with Iron ions wherein the stability constant of the Nitrogen compound and Iron ions is at least 15.
    Type: Grant
    Filed: October 18, 1982
    Date of Patent: August 7, 1984
    Assignee: Konishiroku Photo Industry Co., Ltd.
    Inventor: Mitutaka Arai