Patents by Inventor Toshikazu Umenura

Toshikazu Umenura 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).

  • Method for mixing raw materials for producing oxymethylene copolymers
    Patent number: 4224435
    Abstract: In a method for mixing a trioxane, a polymerization catalyst and a comonomer for producing of oxymethylene copolymers by continuously copolymerizing trioxane with a cyclic ether or a cyclic acetal as a comonomer, the improved method comprises following steps:spouting a comonomer and a polymerization catalyst from nozzle openings which are set adjacent to each other,while washing both openings at the tip end of the nozzles with a flow of trioxane,whereby mixing said comonomer, said polymerization catalyst and said trioxane,and then feeding the mixture to a polymerization reactor to effect copolymerization.The raw materials are mixed together before they are fed to the polymerization reactor, and no clogging trouble at the tip end of the nozzle for feeding a polymerization catalyst occurs. Further the resulting copolymer has a much superior heat stability.
    Type: Grant
    Filed: June 13, 1979
    Date of Patent: September 23, 1980
    Assignee: Mitsubishi Gas chemical Company, Inc.
    Inventors: Akitoshi Sugio, Akira Amamiya, Tadashi Kunii, Tomotaka Furusawa, Mutsuhiko Takeda, Katsumasa Tanaka, Toshikazu Umenura, Kiyokazu Kawaguchi