Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4877495 | Electrolytic coloring of anodized aluminum | Dieter Brodalla | 1989-10-31 |
| 4820417 | Use of citric acid partial esters for the extraction of iron | Ralf Kehl, Werner Schwab | 1989-04-11 |