Issued Patents 1997
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5697984 | Dye preparations with ethylene oxide-castor oil reaction products | Dieter Swatzina, Karin H. Beck, Juliane Krusemann | 1997-12-16 |
| 5663386 | Method for marking mineral oils with amthraquinones | Friedrich-Wilhelm Raulfs | 1997-09-02 |