| abstract |
A lubricant composition with a low phosphorus content or free of phosphorus is obtained by adding an additive of formula (I), where R1 and R2 are independently alkyl having from 1 to about 7 carbon atoms, aryl or aralkyl, or together form an alicyclic or heteroalicyclic radical in which the ring is completed by nitrogen; X is O or S; a is 1 or 2; R3 and R4 are independently H, alkyl or aryl; and Z is CN, (II), (III), (IV), (V) where R5 is hydrogen, alkyl or aralkyl, and (VI) where Y is H, OH, R6 where R6 is alkyl, aryl or aralkyl, OR6, OR7-OH, where R7 is alkylene having from 1 to about 7 carbon atoms, and NR8R9 where R8 and R9 are independently hydrogen, alkyl, cycloaliphatic or heteroalicyclic, or together form an alicylic or heteroalicyclic radical in which the ring is supplemented with nitrogen; provided that when a is 1, Y is not OR6. These additives give lubricant compositions better anti-wear properties and resistance to extreme pressures. |