Patents by Inventor Akiyoshi Kozuma

Akiyoshi Kozuma 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).

  • Process for preparing biaxially drawn thermoplastic polyester film
    Patent number: 4230658
    Abstract: A biaxially drawn thermoplastic polyester film is prepared by concurrent-biaxially drawing a thermoplastic polyester film by a tenter method at a drawing temperature higher than the glass transition temperature of the thermoplastic polyester while maintaining the preheating temperature of the film just prior to drawing at a level greater than the drawing temperature and maintaining the subsequent heat-treating temperature immediately after drawing lower than the preheating temperature and carrying out a reheat-treating process in a plurality of steps while elevating the temperature in each step over a substantially equal temperature range.
    Type: Grant
    Filed: March 26, 1979
    Date of Patent: October 28, 1980
    Assignee: Unitika Limited
    Inventors: Kazuo Matsukura, Kunio Murakami, Tsugio Nagasawa, Tadashi Hayashi, Akiyoshi Kozuma