Issued Patents 1989
Showing 1–4 of 4 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4874849 | Asymmetric 1:2-chromium complex dyes containing two azo dyes, one containing an acetoacetanilide coupling component | Gerhard Back, Fabic Beffa, Ulrich Schlesinger | 1989-10-17 |
| 4836827 | Tris-azo black or grey dyes for leather or pelts | — | 1989-06-06 |
| 4818246 | Process for improving the light-fastness of leather dyeings | Gerhard Back, Josef Koller | 1989-04-04 |
| 4801695 | Iron complexes of azo dyes obtained from naphthylsulfonic acid, resorcinol and nitroaminophenol | — | 1989-01-31 |