HYDRAULIC WORKING FLUID COMPOSITION FOR SHOCK ABSORBER

摘要

PROBLEM TO BE SOLVED: To obtain a hydraulic working fluid composition for shock absorbers capable of increasing the frictional force between piston rod/seal and reducing the frictional force between piston rod/bush and between piston band/cylinder and excellent in abrasion preventiveness. SOLUTION: This hydraulic working fluid composition is characterized by being obtained by incorporating a lubricating base oil with [1] at least one nitrogen-containing compound selected from the group consisting of (A) aliphatic primary amines of the general formula (R1, R2 and R3 are each a 1-30C alkyl or alkenyl) and (B) succinimides each having 8-30C hydrocarbon group and [2] at least one phosphorus-containing compound selected from the group consisting of (C) phosphoric esters each having 3-10C branched hydrocarbon group and (D) phosphoric esters each having 6-18C (alkyl)aryl group.