Patents by Inventor Artur Meyer

Artur Meyer 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 derivatives of 3-(4-hydroxy-anilino)carbazole
    Patent number: 4320060
    Abstract: The process for the preparation of a 3-(4-hydroxyanilino)carbazole of the formula ##STR1## wherein R is hydrogen, alkyl having 1 to 8 carbon atoms or halogenoalkyl having 1 to 8 carbon atoms, comprising reacting a 3-aminocarbazole of the formula ##STR2## with p-hydroquinone or p-aminophenol or a mixture of p-hydroquinone and p-aminophenol in at least stoichiometric amounts by heating to a temperature of 150.degree. to 300.degree. C. with exclusion of oxygen.
    Type: Grant
    Filed: December 31, 1979
    Date of Patent: March 16, 1982
    Assignee: Cassella Aktiengesellschaft
    Inventors: Steffen Piesch, Friedrich Engelhardt, Herbert Wille, Wolf Weidemuller, Artur Meyer
  • Process for isolating sulphur dyestuffs from aqueous crude melts containing sodium polysulphide
    Patent number: 4309178
    Abstract: In the processs for isolating solid sulphur dyestuffs from crude sulphur dyestuff melts, the improvement comprises adding 10.sup.-4 to 1% by weight, relative to the amount of dyestuff, of an organic flocculating auxiliary to the crude dyestuff melt to produce a filterable dyestuff precipitate and then separating said precipitate.
    Type: Grant
    Filed: October 17, 1980
    Date of Patent: January 5, 1982
    Assignee: Cassella Aktiengesellschaft
    Inventors: Georg Daniek, Artur Meyer, Wolf Weidemuller