Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4876356 | Naphtholactam dyes and optical recording medium containing these days | Matthias Dust, Peter Neumann, Heidi Benthack-Thoms, Helmut Barzynski, Klaus D. Schomann +2 more | 1989-10-24 |
| 4837269 | 2-aminothiophene radical substituted by an electron withdrawing group | Karl-Heinz Etzbach, Guenter Hansen, Helmut Reichelt | 1989-06-06 |