Patents by Inventor Dieter Stieler

Dieter Stieler 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).

  • Color photographic recording material containing color couplers
    Patent number: 4529691
    Abstract: Yellow couplers corresponding to the formula ##STR1## wherein Y represents an aromatic, aliphatic or cycloaliphatic group,X represents hydrogen or a releasable group,R.sup.1 represents halogen, andR.sup.2 and R.sup.3 each represent an alkyl group having 1 to 20 carbon atoms,are readily soluble in oil formers and undergo coupling with a high color yield. They are resistant to heat and moisture and undergo color development to yield stable yellow dyes with an absorption maximum below 450 nm. They have a high absorption capacity in the near UV region and are virtually unaffected by fluctuations in the pH during processing.
    Type: Grant
    Filed: April 4, 1984
    Date of Patent: July 16, 1985
    Assignee: Agfa-Gevaert AG
    Inventors: Gunter Renner, Erich Wolff, Friedhelm Sommer, Herbert Stark, Dieter Stieler, Egon Meier