Patents by Inventor Hans Galster

Hans Galster 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).

  • Patent number: 3947515
    Abstract: Process for the preparation of pure aromatic o-hydroxy-carboxylic acid aryl amides by condensing an aromatic o-hydroxy-carboxylic acid with an aryl amine in the presence of phosphorus chlorides in an organic solvent or diluent, which process comprises treating the reaction mixture or the reaction product with 1 to 25 %, calculated on the weight of the reaction product, of an aliphatic amino-polycarboxylic acid as chelate forming agent. It is not necessary to purify the products, because they are obtained in such a pure form that they can be used directly as coupling components for azo pigments.
    Type: Grant
    Filed: February 4, 1975
    Date of Patent: March 30, 1976
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Sighart Miedtank, Adam Ruffer, Hans Galster