Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4843153 | Azo dyes containing thienothiophene radicals as radicals of the diazo component | Heinz Eilingsfeld, Karl-Heinz Etzbach, Guenter Hansen | 1989-06-27 |
| 4837269 | 2-aminothiophene radical substituted by an electron withdrawing group | Karl-Heinz Etzbach, Guenter Hansen, Ernst Schefczik | 1989-06-06 |