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, Ernst Schefczik, Helmut Barzynski, Klaus D. Schomann +2 more | 1989-10-24 |
| 4830951 | Naphtholactamsquaric acid dyes and optical recording materials containing these dyes | Matthias Dust, Peter Neumann, Peter Hauser, Gerhard Wagenblast, Helmut Barzynski +2 more | 1989-05-16 |