| abstract |
Additives for lubricating oils and fuel oils, which contain as the main component disulfide compounds represented by the general formula (I) or (IV): R1OOC-A1-Sx-A2-COOR2 (I) (wherein R1 and R2 are each independently C1-30 hydrocarbyl which may contain oxygen, sulfur or nitrogen; A1 and A2 are each independently CR3R4 wherein R3 and R4 are each independently hydrogen or C1-20 hydrocarbyl; and x is 2), and R1OOC-A3-Sx-A4-COOR2 (IV) (wherein R1 and R2 are as defined above; A3 and A4 are each independently CR5R6-CR7R8 wherein R5 to R8 are each independently hydrogen or C1-20 hydrocarbyl; and x is 2). The additives exhibit excellent functions as extreme -pressure additive or anti-wear additive and little corrode nonferrous metals, thus being useful as sulfur-containing extreme-pressure additives suitable for lubricating oils and fuel oils. |