Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4882095 | Preparation of alkoxy(iso)violanthrenediones | Reinhard Helwig | 1989-11-21 |
| 4824608 | Preparation of C.I. Vat Blue 16 | Reinhard Helwig | 1989-04-25 |
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4882095 | Preparation of alkoxy(iso)violanthrenediones | Reinhard Helwig | 1989-11-21 |
| 4824608 | Preparation of C.I. Vat Blue 16 | Reinhard Helwig | 1989-04-25 |