Issued Patents 1997
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5626668 | Process for the water-repellent impregnation of plaster | Richard Weidner, Hans Mayer | 1997-05-06 |
| 5624481 | Process for the water-repellent impregnation of plaster | Hans Mayer, Johannes Mittermeier | 1997-04-29 |