Patents by Inventor Tsuneyoshi Miwa

Tsuneyoshi Miwa 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).

  • Biaxially stretched isotropic polyimide film having specific properties
    Patent number: 5460890
    Abstract: An isotropic, biaxially stretched polyimide film prepared by casting a solution of a polyamic acid precursor in an organic solvent containing a cyclization catalyst and dehydrating agent onto the surface of a support, imidizing the polyamic acid to give a continuous self-supporting gel film containing 5-50% by weight of solids, stretching the gel film in the machine direction (MD) at a ratio of 1.1-1.9, and stretching in the transverse direction (TD) with respect to the machine direction so as to maintain a TD/MD stretch ratio of from 0.9 to 1.3.
    Type: Grant
    Filed: February 26, 1992
    Date of Patent: October 24, 1995
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Masakazu Okahashi, Akimitsu Tsukuda, Tsuneyoshi Miwa, James R. Edman, Charles M. Paulson, Jr.
  • Process for preparing biaxially stretched isotropic polyimide film
    Patent number: 5324475
    Abstract: An isotropic, biaxially stretched polyimide film prepared by casting a solution of a polyamic acid precursor in an organic solvent containing a cyclization catalyst and dehydrating agent onto the surface of a support, imidizing the polyamic acid to give a continuous self-supporting gel film containing 5-50% by weight of solids, stretching the gel film in the machine direction (MD) at a ratio of 1.1-1.9, and stretching in the transverse direction (TD) with respect to the machine direction so as to maintain a TD/MD stretch ratio of from 0.9 to 1.3.
    Type: Grant
    Filed: February 25, 1993
    Date of Patent: June 28, 1994
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Masakazu Okahashi, Akimitsu Tsukuda, Tsuneyoshi Miwa, James R. Edman, Charles M. Paulson, Jr.
  • Fiber and film forming polyester composition
    Patent number: 4067855
    Abstract: Polyester compositions suitable for fiber and film formation contain from 0.2 to 3.0% by weight of fine particles of uniform size and possess sufficient slippery tendency, appropriate opacity and crystallizing potential; said particles containing lithium and phosphorus as a lithium salt of a phosphoric acid ester constituent of short chain polyesters.
    Type: Grant
    Filed: November 20, 1975
    Date of Patent: January 10, 1978
    Assignee: Toray Industries, Inc.
    Inventors: Tsuneyoshi Miwa, Shinji Nakazawa, Masaaki Itoga, Keizo Sano, Itaru Nakamura, Taigi Watanabe, Yasuhiko Shingu