Patents by Inventor HARUKI MOKUDAI

HARUKI MOKUDAI 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: 10647817
    Abstract: The present invention is to provide a method that can produce polyarylene sulfide having a high viscosity at a high yield. The method of producing polyarylene sulfide according to an embodiment of the present invention includes: a preparation step of preparing a mixture containing an organic amide solvent, a sulfur source, a dihalo aromatic compound, and an alkali metal hydroxide; a first-stage polymerization step of initiating a polymerization reaction by heating the mixture and producing a prepolymer until a pH of a reaction system reaches a range of 10 to 11; and a second-stage polymerization step of continuing the polymerization reaction.
    Type: Grant
    Filed: September 30, 2016
    Date of Patent: May 12, 2020
    Assignee: KUREHA CORPORATION
    Inventors: Akihiro Konno, Ken-Ichi Takaki, Haruki Mokudai, Hiroyuki Sato
  • Patent number: 10570255
    Abstract: Provided is a method of producing polyarylene sulfide at low cost while productivity enhancement and resource saving are attempted by avoiding the use of a complicated step and special apparatus (facility). The method of producing polyarylene sulfide according to an embodiment of the present invention includes: a preparation step of preparing a mixture containing an organic amide solvent, a sulfur source, a dihalo aromatic compound, and an alkali metal hydroxide in an amount less than an equimolar amount relative to an amount of the sulfur source; a first-stage polymerization step of initiating a polymerization reaction by heating the mixture, and producing a prepolymer having a dihalo aromatic compound conversion ratio of 50% or greater; and a second-stage polymerization step of adding an alkali metal hydroxide such that the alkali metal hydroxide is in an amount of 1.00 to 1.10 mol per 1 mol of the sulfur source, and continuing the polymerization reaction in a homogeneous liquid phase condition.
    Type: Grant
    Filed: September 30, 2016
    Date of Patent: February 25, 2020
    Assignee: KUREHA CORPORATION
    Inventors: Haruki Mokudai, Akihiro Konno, Hiroyuki Sato
  • Publication number: 20180265636
    Abstract: The present invention is to provide a method that can produce polyarylene sulfide having a high viscosity at a high yield. The method of producing polyarylene sulfide according to an embodiment of the present invention includes: a preparation step of preparing a mixture containing an organic amide solvent, a sulfur source, a dihalo aromatic compound, and an alkali metal hydroxide; a first-stage polymerization step of initiating a polymerization reaction by heating the mixture and producing a prepolymer until a pH of a reaction system reaches a range of 10 to 11; and a second-stage polymerization step of continuing the polymerization reaction.
    Type: Application
    Filed: September 30, 2016
    Publication date: September 20, 2018
    Inventors: AKIHIRO KONNO, KEN-ICHI TAKAKI, HARUKI MOKUDAI, HIROYUKI SATO
  • Publication number: 20180244848
    Abstract: Provided is a method of producing polyarylene sulfide at low cost while productivity enhancement and resource saving are attempted by avoiding the use of a complicated step and special apparatus (facility). The method of producing polyarylene sulfide according to an embodiment of the present invention includes: a preparation step of preparing a mixture containing an organic amide solvent, a sulfur source, a dihalo aromatic compound, and an alkali metal hydroxide in an amount less than an equimolar amount relative to an amount of the sulfur source; a first-stage polymerization step of initiating a polymerization reaction by heating the mixture, and producing a prepolymer having a dihalo aromatic compound conversion ratio of 50% or greater; and a second-stage polymerization step of adding an alkali metal hydroxide such that the alkali metal hydroxide is in an amount of 1.00 to 1.10 mol per 1 mol of the sulfur source, and continuing the polymerization reaction in a homogeneous liquid phase condition.
    Type: Application
    Filed: September 30, 2016
    Publication date: August 30, 2018
    Inventors: HARUKI MOKUDAI, AKIHIRO KONNO, HIROYUKI SATO