Issued Patents All Time
Showing 1–7 of 7 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5756757 | Process for the preparation of 3-hydroxy-N-benzimidazolon-5-yl-2-naphthamide in the high purity required of azo pigments | Michael Meier, Heinrich Volk | 1998-05-26 |
| 4916257 | Process for the purification of 2-hydroxynaphthalene-6-carboxylic acid | Helmold von Plessen, Siegbert Rittner, Heinrich Volk, Werner Wykypiel | 1990-04-10 |
| 4831168 | Process for preparing 2-hydroxydibenzofuran-3-carboxylic acid and alkali metal salts thereof | Wolfgang Ironich | 1989-05-16 |
| 4638053 | Process for the preparation of chlorozincate salts of benzo thiazolium azo dyestuffs by alkylating with dialkylsulfate in aqueous medium in the presence of Zn-containing acid acceptor at pH.ltoreq.7 | Reinhard Mohr | 1987-01-20 |
| 4618701 | Process for preparing 6-acetoxy-2-naphthoic-acid and pure 6-hydroxy-2-naphthoic acid | Wolfgang Ironich, Heinrich Volk | 1986-10-21 |
| 4423226 | Zinc chloride complex compounds | Reinhard Mohr | 1983-12-27 |
| 4269768 | Process for the preparation of chlorozincate salts of thiazolium azo dyestuffs | Kurt Hohmann, Reinhard Mohr | 1981-05-26 |