Additives for lubricating oils and for fuel oils which comprise as the main component a disulfide represented by the following general formula (I) or (IV):
R
1
OOC-A
1
-S
x
-A
2
-COOR
2
(I)
(R
1
and R
2
each independently represent a hydrocarbyl group which has 1 to 30 carbon atoms and may have oxygen atom, sulfur atom or nitrogen atom, A
1
and A
2
each independently represent a group represented by CR
3
R
4
, R
3
and R
4
each independently representing hydrogen atom or a hydrocarbyl group having 1 to 20 carbon atoms, and x represents 2.)
R
1
OOC-A
3
-S
x
-A
4
-COOR
2
(IV)
(R
1
and R
2
are as defined above, A
3
and A
4
each independently represent a group represented by CR
5
R
6
—CR
7
R
8
, R
5
to R
8
each independently representing hydrogen atom or a hydrocarbyl group having 1 to 20 carbon atoms, and x represents 2.) The additives exhibit excellent functions as the extreme pressure additive and the antiwear agent and the suppressed corrosive property to nonferrous metals and are advantageously used as the sulfur-based extreme pressure additives for lubricating oils and fuel oils.
润滑油和燃料油的添加剂包括以下通式(I)或(IV)所表示的二
硫化物作为主要成分:
R1OOC-A1-Sx-A2-COOR2(I)(其中,R1和R2分别独立地表示具有1至30个碳原子且可能具有氧原子、
硫原子或氮原子的烃基,A1和A2分别独立地表示CR3R4所表示的基团,R3和R4分别独立地表示氢原子或具有1至20个碳原子的烃基,x表示2。)
R1OOC-A3-Sx-A4-COOR2(IV)(其中,R1和R2如上定义,A3和A4分别独立地表示CR5R6-CR7R8所表示的基团,R5至R8分别独立地表示氢原子或具有1至20个碳原子的烃基,x表示2。)
这些添加剂表现出极压添加剂和抗磨剂的优异功能,对非
铁质
金属具有抑制腐蚀性能,是用于润滑油和燃料油的
硫基极压添加剂的有利选择。