Patents by Inventor Kiyokazu Kawaguchi

Kiyokazu Kawaguchi 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).

  • Stabilized oxymethylene copolymer composition
    Patent number: 4342680
    Abstract: A stabilized oxymethylene copolymer composition comprising an oxymethylene copolymer, and incorporated therein,(1) at least one amine-substituted triazine of the following formula ##STR1## wherein R.sub.1, R.sub.2 and R.sub.3 are a hydrogen atom, a halogen atom, a hydroxyl group, an alkyl group, an alkoxy group, an aryl group, a hydrogenated aryl group, an amino group or a substituted amino group, and at least one of them is an amino group or a substituted amino group,(2) at least one sterically hindered phenol of the following formula ##STR2## wherein R.sub.4 and R.sub.5 are an alkyl group, a substituted alkyl group or a substituted triazole group and R.sub.
    Type: Grant
    Filed: March 20, 1980
    Date of Patent: August 3, 1982
    Assignee: Mitsubishi Gas Chemical Company, Inc.
    Inventors: Akitoshi Sugio, Akira Amemiya, Masaharu Kimura, Yoshiharu Otuki, Kiyokazu Kawaguchi
  • 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
  • Process for polymerizing trioxane
    Patent number: 4189565
    Abstract: A process for polymerizing trioxane made from an aqueous solution of methanol-containing formaldehyde by a conventional method or copolymerizing the trioxane with another monomer, characterized bycooling the trioxane to crystallize it,allowing the trioxane in a crystalline state to stand in an open system in an atmosphere of air or an inert gas to remove polyoxymethylene dimethoxide from the trioxane,melting the trioxane, andpolymerizing the trioxane or copolymerizing the trioxane and the another monomer.
    Type: Grant
    Filed: December 20, 1978
    Date of Patent: February 19, 1980
    Assignee: Mitsubishi Gas Chemical Company, Inc.
    Inventors: Akitoshi Sugio, Akira Amemiya, Tetsuya Abe, Tomotaka Furusawa, Takeo Suzumori, Mutsuhiko Takeda, Masaharu Kimura, Yoshiharu Ohtsuki, Katsumasa Tanaka, Toshikazu Umemura, Kiyokazu Kawaguchi, Michio Ohba