Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5182372 | Aniline-based oil-soluble azo dyes | Guenter Hansen, Helmut Reichelt, Christos Vamvakaris, Georg Zeidler | 1993-01-26 |
| 4904765 | Dye mixtures containing an oil-soluble dye and an acid-extractable dye | Rudolf Denninger | 1990-02-27 |