Issued Patents All Time
Showing 1–9 of 9 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4431824 | Preparation of 4,4',7,7'-tetrachlorothioindigo pigments of high color strength | Helmut Hoch | 1984-02-14 |
| 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 |
| 4298534 | Preparation of brilliant, transparent pigmentary bromo-isoviolanthrone of high tinctorial strength | Helmut Hoch, Erwin Hahn | 1981-11-03 |
| 4286094 | Preparation of a pigmentary form of perylene-3,4,9,10-tetracarboxylic acid diimide | Helmut Hoch | 1981-08-25 |
| 4278606 | Preparation of 1-amino-2-phenoxy-4-hydroxyanthraquinone | Heinz Eilingsfeld, Helmut Reinicke, Fritz Traub | 1981-07-14 |
| 4217455 | Preparation of transparent and easily dispersible perylene-3,4,9,10-tetracarboxylic acid diimide pigments of high tinctorial strength | Helmut Hoch | 1980-08-12 |
| 4197250 | Manufacture of 1-amino-2-bromo-4-hydroxyanthraquinone | Joerg Redeker, Enno Spohler | 1980-04-08 |
| 4189582 | Process for upgrading the color value of 3,4,9,10-tetracarboxylic acid N,N'-bis-methylimide | Helmut Hoch | 1980-02-19 |