Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4845223 | Fluorescent aryloxy-substituted perylene-3,4,9,10-tetracarboxylic acid diimides | Guenther Seybold | 1989-07-04 |
| 4818341 | Production of paper and paperboard of high dry strength | Hans-Juergen Degen, Sigberg Pfohl, Volkmar Weberndoerfer, Gerd Rehmer, Michael Kroener | 1989-04-04 |