Patents by Inventor John S. Letinski

John S. Letinski 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).

  • Moldable polybenzimidazole filaments and process for producing molded and foamed products from these filaments
    Patent number: 4810730
    Abstract: This invention relates to a process for the production of high strength polybenzimidazole filaments and molded products made from such filaments. The filaments produced by this process contain from about 10 to about 50 percent by weight residual solvent and can be heated at a temperature of about 350.degree. C. to about 600.degree. C. to produce three-dimensional foamed articles.
    Type: Grant
    Filed: May 6, 1987
    Date of Patent: March 7, 1989
    Assignee: Hoechst Celanese Corp.
    Inventors: John S. Letinski, Gunilla E. Gillberg-LaForce
  • Process for the production of molded polybenzimidazole articles and the resultant articles
    Patent number: 4717619
    Abstract: Disclosed herein is a process for the production of shaped polybenzimidazole articles which comprises forming a solvent solution of the polymer, depositing the solution on a support to form a film, removing sufficient solvent from the deposited film such that the film contains from about 10 to about 30 percent by weight of said solvent and compression molding the resulting product into a shaped article. Thus, this invention provides a unique process for the forming of molded shaped articles from polybenzimidazole based polymers.
    Type: Grant
    Filed: October 29, 1985
    Date of Patent: January 5, 1988
    Assignee: Hoechst Celanese Corporation
    Inventor: John S. Letinski
  • Process for the preparation of polybenzimidazole foams
    Patent number: 4681716
    Abstract: The present invention is a process for the preparation of polybenzimidazole foams. Polybenzimidazoles containing 10 to 30 percent by weight residual solvent can be heated at a temperature of about 350.degree. C. to about 600.degree. C. to produce three dimensional foamed articles.
    Type: Grant
    Filed: March 3, 1986
    Date of Patent: July 21, 1987
    Assignee: Celanese Corporation
    Inventor: John S. Letinski