Patents by Inventor Ewald Katzschmann

Ewald Katzschmann 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 THE PREPARATION OF TEREPHTHALIC ACID
    Patent number: 3944602
    Abstract: An after-treatment or purification process for oxidation products produced by the air oxidation of a mixture of p-toluic acid methyl ester and p-xylene to provide terephthalic acid wherein the oxidation products are heated to an elevated temperature under pressure and a substance such as p-xylene, water, a lower carboxylic acid containing from 1 - 4 carbon atoms and mixtures thereof is added thereto. Subsequently, the desired terephthalic acid is separated from the resultant reaction mixture.
    Type: Grant
    Filed: September 7, 1971
    Date of Patent: March 16, 1976
    Assignee: Chemische Werke Witten GmbH
    Inventor: Ewald Katzschmann