Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4867890 | Lubricating oil compositions containing ashless dispersant, zinc dihydrocarbyldithiophosphate, metal detergent and a copper compound | Terence Colclough, Frederick A. Gibson | 1989-09-19 |
| 4839094 | Overbased alkali metal additives | John A. Cleverley | 1989-06-13 |