| 摘要 |
PURPOSE:To obtain a hydraulic fluid composition free from precipitation of boric acid even at a high water-content, having high boiling point in hydrated state and exhibiting excellent low-temperature viscosity characteristics, by combining a polyoxyalkylene glycol monoalkyl ether and its boric acid ester with a specific amine compound. CONSTITUTION:The objective composition is composed of (A) 10-80wt.% of a polyoxyalkylene glycol monoalkyl ether, (B) 18-85wt.% of a boric acid ester of formula II and (C) 2-15wt.% of an aliphatic alkoxypropyl alkanolamine of formula III (R<1> and R<2> are 1-3C alkyl; R<3> is 1-9C hydrocarbon group; A<1>O-A<4>O are 2-4C oxyalkylene; m and n are 2-5; p and q are >=0; p+q is 1-6). The composition forms little precipitate and satisfies the specification of DOT-4 and DOT-5 brake fluid. |
