| abstract |
(57) [Summary] (Modified) [Purpose] To provide a hydraulic fluid composition for shock absorbers, which is excellent in the durability of the friction reducing effect (the change over time with use is small). [Constitution] With respect to a lubricating base oil, (A) at least one kind of phosphorus-containing compound selected from the following (a) to (c); (a) a phosphoric acid ester represented by the following formula (1) , (B) a phosphite represented by the following formula (2), (C) The above-mentioned (a) phosphate ester and / or (b) A salt of a phosphite ester and an aliphatic monoamine having 8 to 22 carbon atoms, [for example, dioleyl acid phosphate], and (B) at least one kind selected from the following (d) to (e) A nitrogen-containing compound; (d) an aliphatic polyamine represented by the following formula (3), (E) A salt of the above-mentioned (d) an aliphatic polyamine and a fatty acid having 6 to 22 carbon atoms, [for example, oleylethylenediamine]. A hydraulic fluid composition for shock absorbers, characterized in that: is added as an essential component. |