Patents by Inventor Wilfried Krulla

Wilfried Krulla 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 pure cyanuric acid
    Patent number: 4278794
    Abstract: Pure cyanuric acid is prepared from crude or waste melamine by introducing the melamine into 70 to 80% strength sulfuric acid at room temperature and heating the reaction mixture to 150.degree. to 190.degree. C., the water introduced with the sulfuric acid being distilled off during the heating period.
    Type: Grant
    Filed: July 1, 1980
    Date of Patent: July 14, 1981
    Assignee: Chemie Linz Aktiengesellschaft
    Inventors: Karlheinz Wegleitner, Wilfried Krulla, Richard Willim