| 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 |
