Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4877595 | Method of compressing pyrogenically prepared silicic acid | Reinhard Klingle | 1989-10-31 |
| 4853190 | Process & apparatus for the production of hydrogen cyanide | Hans Schaefer, Carl Voight, Wolf-Dieter Pfeifer | 1989-08-01 |