Issued Patents 1997
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5681791 | Color former mixture | Rudolf Zink | 1997-10-28 |
| 5670082 | Bleaching auxiliary | Albert Stehlin, Thomas Maier | 1997-09-23 |
| 5646271 | Bleaching auxiliary | Albert Stehlin, Thomas Maier | 1997-07-08 |