Issued Patents All Time
Showing 26–28 of 28 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4238404 | Process for the preparation of isocyanate derivatives of aliphatic, cycloaliphatic, and araliphatic compounds | Hans Zengel, Rainer Zielke, Erich Klimesch | 1980-12-09 |
| 4210602 | Process for the preparation of asymmetrical N-phenyl-N'-substituted para-phenylene diamines | Hans Zengel | 1980-07-01 |
| 4203916 | Preparation of trans cyclohexane 1,4 diisocyanate | Hans Zengel | 1980-05-20 |