Patents by Inventor Donald Roy Cowsar

Donald Roy Cowsar 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).

  • Thermoplastic hydrogels
    Patent number: 4064086
    Abstract: Thermoplastic hydrogels are prepared by making condensation polymers of spirolactones of the formula: ##STR1## with a difunctional compound capable of opening the lactone rings. The thermoplastic hydrogels can be cross-linked. In the formula the total of n and m and also of n' and m' is 2 to 5 and the R groups are H or hydrocarbyl with not over 3 R groups being hydrocarbyl. Most preferably all R groups are H and n, m, n' and m' are all 1.
    Type: Grant
    Filed: July 13, 1976
    Date of Patent: December 20, 1977
    Assignee: National Patent Development Corporation
    Inventors: Donald Roy Cowsar, Albert Charles Tanquary