Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4665016 | Chromogenic compounds, a process for their preparation and their use | Helmut Heber, Volker Teetz | 1987-05-12 |
| 4508644 | Chromogenic compounds, a process for their preparation and their use | Helmut Heber, Volker Teetz | 1985-04-02 |