Patents by Inventor John David Hartzler

John David Hartzler 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).

  • Polyhydrazide spinning solutions
    Patent number: 4039502
    Abstract: This invention relates to film- and fiber-forming polyhydrazide solutions (dopes) in a solvent system comprising concentrated sulfuric acid or mixtures thereof with fluorosulfonic acid. Some dopes of this invention are optically anisotropic.
    Type: Grant
    Filed: January 2, 1976
    Date of Patent: August 2, 1977
    Assignee: E. I. Du Pont de Nemours & Company
    Inventors: John David Hartzler, Paul Winthrop Morgan