ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 23, Number 1
JKCSEZ 23(1)
February 20, 1979 

Metallic dialkyldithiophosphates are widely used in lubricating oils as antioxidant and antiwear agents. Zinc DDTP are used most frequently in lubricating oil. Zinc, lead, tin and cobalt DDTP were prepared with primary and secondary alkyl groups. The effects of oxidation, thermal stability, metal corrosion and antiwear of each metallic DDTP prepared were studied. Based on the results, cobalt DDTP has a significant effect of antiwear on chrome alloy steel comparing with the other metallic DDTP. Also cobalt DDTP has a characteristic property of thermal sensitivity in its color, which was shown by the color change from brown to blue over a certain temperature. Another phenomenon obtained was that all metallic DDTP initiates the effect of antioxidation at the time of reaching to a certain effective acid concentration in lubricating oil.