Patents by Inventor Ryuta NAKAGAKI

Ryuta NAKAGAKI 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).

  • Polyimide fiber and method for producing polyimide fiber
    Patent number: 10662555
    Abstract: The method for producing a polyimide fiber includes a coagulation step of forming a polyimide precursor fiber by extruding a polyimide precursor solution containing a polyimide precursor and a compound having an acid dissociation constant (pKa) of a conjugate acid in water at 25° C. of 6.0 to 10 inclusive and an octanol-water partition coefficient (Log P) at 25° C. of ?0.75 to 0.75 inclusive into a poor solvent or nonsolvent for the polyimide precursor; and a heat drawing step of forming the polyimide fiber by drawing the polyimide precursor fiber while heating same. The polyimide fiber of the present disclosure has a physical property such that the coefficient of thermal expansion thereof is in the range of ?15 ppm/K to 0 ppm/K inclusive.
    Type: Grant
    Filed: February 6, 2017
    Date of Patent: May 26, 2020
    Assignee: I.S.T. CORPORATION
    Inventors: Ryuta Nakagaki, Katsuki Morishima, Koji Moriuchi
  • POLYIMIDE FIBRE AND METHOD FOR PRODUCING POLYIMIDE FIBRE
    Publication number: 20170283990
    Abstract: The method for producing a polyimide fiber includes a coagulation step of forming a polyimide precursor fiber by extruding a polyimide precursor solution containing a polyimide precursor and a compound having an acid dissociation constant (pKa) of a conjugate acid in water at 25° C. of 6.0 to 10 inclusive and an octanol-water partition coefficient (Log P) at 25° C. of ?0.75 to 0.75 inclusive into a poor solvent or nonsolvent for the polyimide precursor; and a heat drawing step of forming the polyimide fiber by drawing the polyimide precursor fiber while heating same. The polyimide fiber of the present disclosure has a physical property such that the coefficient of thermal expansion thereof is in the range of ?15 ppm/K to 0 ppm/K inclusive.
    Type: Application
    Filed: February 6, 2017
    Publication date: October 5, 2017
    Inventors: Ryuta NAKAGAKI, Katsuki MORISHIMA, Koji MORIUCHI