Patents by Inventor Dölf Käser

Dölf Käser 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).

  • Dyes incorporating annionic and cationic groups
    Patent number: 7066969
    Abstract: The present invention relates to novel compounds of the formulae A, D1, D2, R1 and n are as defined in the description the compounds being in an internal or external salt form, or mixtures of compounds (1) and (2), a process for their preparation and preparations containing them used for dyeing paper.
    Type: Grant
    Filed: July 11, 2002
    Date of Patent: June 27, 2006
    Assignee: Ciba Specialty Chemicals Corporation
    Inventors: Michael Lennartz, Dölf Käser, Sandra Weiss