| 摘要 |
PROBLEM TO BE SOLVED: To obtain a power steering fluid composition which can effectively control the corrosion of a bearing metal and has low friction by blending a base oil selected from mineral oils or synthetic oils with at least one phosphate compound selected from alkyl phosphate compounds, phenyl phosphate compounds, etc., a thiadiazole derivative, and a sufurized mixture of alkaline earth metal salts of hydroxyalkylbenzoic acids and alkylphenols each in a specified amount. SOLUTION: This composition is obtained by mixing at least one base oil selected from mineral oils or synthetic oils with at least one compound (A) selected from alkyl phosphate compounds, phenyl phosphate compounds, etc., in an amount of 0.005-2.0wt.% in terms of phosphorus, at least on thiadiazole derivative (B) represented by the formula (R<1> and R<2> are each a 1-12C alkyl), in an amount of 0.05-1.0wt.%, and a sulfurized mixture (C) of alkaline earth metal salts of hydroxyalkylbenzoic acids and alkylphenols, in an amount of 0.1-6.0wt.%. |
