Issued Patents 1989
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4880497 | Preparation of water-soluble copolymers containing vinylamine units, and their use as wet strength agents and dry strength agents for paper | Michael Kroener, Heinrich Hartmann, Walter Denzinger | 1989-11-14 |
| 4818341 | Production of paper and paperboard of high dry strength | Hans-Juergen Degen, Volkmar Weberndoerfer, Gerd Rehmer, Michael Kroener, Andreas Stange | 1989-04-04 |
| 4804387 | Liquid black dye mixture | Hans-Juergen Degen, Rudolf Bermes | 1989-02-14 |