Issued Patents 1982
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4332955 | Preparation of transparent pigmentary forms of 4,4',7,7'-tetrachlorothioindigo | Helmut Hoch, Erwin Hahn | 1982-06-01 |
| 4323510 | Brown vat dye and its preparation | Helmut Hoch | 1982-04-06 |