Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4874848 | Asymmetrical polyazo chromium complex dyes comprising resorcinol as a coupling component | Gerhard Back | 1989-10-17 |
| 4799933 | Process for the trichromatic dyeing of leather | Josef Koller | 1989-01-24 |