Patents by Inventor Hideto Umekawa

Hideto Umekawa 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: 5391225
    Abstract: An alkenylsuccinic acid emulsion sizing agent, wherein said alkenylsuccinic acid emulsion sizing agent has a solid concentration of at least 25% by weight, and comprises active components comprising an alkenylsuccinic acid present in an amount of at least 50 parts by weight, per 100 parts by weight of the total active components in the alkenylsuccinic acid emulsion sizing agent; and, wherein said alkenylsuccinic acid is obtained by dispersing a product prepared by reacting a branched inner olefin having from 9 to 18 carbon atoms with maleic anhydride in water using an amphoteric acrylamide-series polymer.
    Type: Grant
    Filed: October 13, 1993
    Date of Patent: February 21, 1995
    Assignee: Mitsubishi Oil. Co., Ltd.
    Inventors: Hatanaka Shigeto, Hideto Umekawa
  • Patent number: 5306757
    Abstract: Disclosed is an emulsified alkenylsuccinic acid sizing agent useful for acid papermaking. The sizing agent has a solid concentration of at least 25% by weight and comprises an alkenylsuccinic acid which is the reaction product of a branched internal olefin and maleic anhydride and which has been dispersed in water by an emulsifying and dispersing agent comprising polyvinyl alcohol. The sizing agent results in good storage stability and has an excellent sizing effect at a low addition ratio immediately after completion of high-temperature papermaking and over a wide pH range.
    Type: Grant
    Filed: December 21, 1992
    Date of Patent: April 26, 1994
    Assignee: Mitsubishi Oil Co., Ltd.
    Inventors: Shigeto Hatanaka, Yoshio Takahashi, Hideto Umekawa
  • Patent number: 5219912
    Abstract: An emulsified alkenylsuccinic acid sizing agent having a solid content of not less than 25% by weight is disclosed, which comprises a composition having not less than 25 parts by weight of alkenylsuccinic acid derived from the reaction product of a branched internal olefin of 12-18 carbon atoms with maleic anhydride, and being dispersed in water with an anionic polymer type dispersant or with an anionic polymer type dispersant and an emulsifier.
    Type: Grant
    Filed: July 10, 1991
    Date of Patent: June 15, 1993
    Assignee: Mitsubishi Oil Co., Ltd.
    Inventors: Yoshio Takahashi, Junji Okazaki, Hideto Umekawa, Toshihiro Tahara