Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4867894 | Pour point improving additives for mineral oils | Horst Pennewiss, Helmut Knoell | 1989-09-19 |
| 4822508 | Shear stable multirange oils having an improved viscosity index | Horst Pennewiss, Helmut Knoell | 1989-04-18 |