Patents by Inventor John R. Richwine

John R. Richwine 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).

  • 2,5-Dimercapto-1,3,4-thiadiazole as a cross-linker for saturated, halogen-containing polymers
    Patent number: 4288576
    Abstract: It has been found that saturated, halogen-containing polymers can be cross-linked to yield stable vulcanizates using 2,5-dimercapto-1,3,4-thiadiazole in the presence of certain basic materials in normal vulcanization procedures.
    Type: Grant
    Filed: June 29, 1979
    Date of Patent: September 8, 1981
    Assignee: Hercules Incorporated
    Inventor: John R. Richwine
  • Vulcanizing halogen-containing polymers
    Patent number: 4128510
    Abstract: Halogen-containing polymers can be crosslinked by heating with certain derivatives of 2,5-dimercapto-1,3,4-thiadiazole, such as the monobenzoate derivative, and a basic material to produce useful vulcanizates of increased strength and insolubility in organic solvents. Concentrates of the derivatives of 2,5-dimercapto-1,3,4-thiadiazole may be prepared by incorporating the thiadiazole in a binder material such as a polymer, wax, rosin, etc. for subsequent compounding with the halogen-containing polymer to be crosslinked.
    Type: Grant
    Filed: April 18, 1977
    Date of Patent: December 5, 1978
    Assignee: Hercules Incorporated
    Inventor: John R. Richwine