Patents by Inventor Keiji Kaiho

Keiji Kaiho 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).

  • Polyphenylene sulfide fiber, filter cloth comprising polyphenylene sulfide fiber, and method for producing polyphenylene sulfide fiber
    Patent number: 9365954
    Abstract: The present invention provides: a polyphenylene sulfide fiber that has excellent tensile strength; and a polyphenylene sulfide fiber that decreases in toughness to a small extent even when subjected to a long-term heat treatment and has excellent tensile strength. The polyphenylene sulfide fiber according to the present invention is characterized by comprising a polyphenylene sulfide resin having a weight average molecular weight of 50000 to 80000 inclusive, having a rigid amorphous content of 50% or more, and having a crystal size of 5 nm or more in the direction of a (111) crystal plane.
    Type: Grant
    Filed: February 19, 2013
    Date of Patent: June 14, 2016
    Assignee: TORAY INDUSTRIES, INC.
    Inventors: Takeshi Sugimoto, Keiji Kaiho, Koichiro Maeda
  • POLYPHENYLENE SULFIDE FIBER, FILTER CLOTH COMPRISING POLYPHENYLENE SULFIDE FIBER, AND METHOD FOR PRODUCING POLYPHENYLENE SULFIDE FIBER
    Publication number: 20150013296
    Abstract: The present invention provides: a polyphenylene sulfide fiber that has excellent tensile strength; and a polyphenylene sulfide fiber that decreases in toughness to a small extent even when subjected to a long-term heat treatment and has excellent tensile strength. The polyphenylene sulfide fiber according to the present invention is characterized by comprising a polyphenylene sulfide resin having a weight average molecular weight of 50000 to 80000 inclusive, having a rigid amorphous content of 50% or more, and having a crystal size of 5 nm or more in the direction of a (111) crystal plane.
    Type: Application
    Filed: February 19, 2013
    Publication date: January 15, 2015
    Inventors: Takeshi Sugimoto, Keiji Kaiho, Koichiro Maeda