Issued Patents 1997
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5693135 | Interference pigments containing reduced titanium oxide layers for preparing forgeryproof documents and packaging | Raimund Schmid, Norbert Mronga, Werner Ostertag, Helmut Schmidt | 1997-12-02 |
| 5624487 | Preparation of bluish luster pigments | Helmut Schmidt, Werner Ostertag, Hermann Bidlingmaier, Norbert Mronga, Juan Antonio Gonzalez Gomez +2 more | 1997-04-29 |