Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4521579 | High molecular weight water-soluble polymers useful in deoiling sand and rock masses | Friedrich Engelhardt, Hermann Schmitz, Walter Gulden | 1985-06-04 |
| 4451631 | Agent and method for deoiling sand and rock masses | Friedrich Engelhardt, Hermann Schmitz, Walter Gulden | 1984-05-29 |