Issued Patents All Time
Showing 1–8 of 8 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5225574 | Preparation of phthalic anhydride from o-xylene | Heinrich Aichinger, Wilhelm Ruppel, Rolf Seubert, Karl-Heinz Boehning, Walter Scheidmeir +1 more | 1993-07-06 |
| 5206433 | Preparation of formic acid | Heinz Hohenschutz, Hans Kiefer | 1993-04-27 |
| 4961827 | Obtaining very pure maleic anhydride from crude maleic anhydride | Dieter Zimmerling, Rolf Seubert, Karl Fischer, Friedrich Sauer | 1990-10-09 |
| 4921977 | Obtaining maleic anhydride not prone to discolor | Gerhard Michl, Rolf Seubert | 1990-05-01 |
| 4568427 | Continuous isolation of phthalic anhydride and maleic anhydride from reaction gases | Eckehard Danz, Gerd Dumbgen, Ernest Miesen, Friedrich Wirth | 1986-02-04 |
| 4369327 | Preparation of phthalic anhydride | Dieter Stockburger, Wilhelm Schultz, Friedrich Wirth, Herwig Hoffmann, Bernhard Holzknecht +1 more | 1983-01-18 |
| 4218568 | Preparation of formic acid | Heinz Hohenschutz, Hans Kiefer | 1980-08-19 |
| 4217460 | Isolation of formic acid from its aqueous solutions | Heinz Hohenschutz, Hans Kiefer | 1980-08-12 |