HYDRAULISCHE FLUESSIGKEITEN UND EINRICHTUNGEN

1341901 Hydraulic fluids BURMAH OIL TRADING Ltd 18 Jan 1972 [21 Jan 1971 21 July 1971] 2873/71 and 34240/71 Heading C5F A hydraulic fluid comprises in major amount (A) 10-90 wt. per cent of one or more esters of formula where R is straight or branched C 2+ alkylene R1 is phenyl or C 1-4 alkyl, R2 is ethylene, propylene or butylene; n is 0-3, R3 is -CH 3 or -C 2 H 5 , R4 is ethylene or propylene, and m is an integer (each n or R1-R4 being the same or different); and (B) 1-90 wt per cent of one or more borate esters of formula where R5 is straight or branched alkylene, R6 is alkyl, p is an integer, q is 2-6, R7 is the residue of a di- or polyhydroxy organic compound having a member of reactive OH groups equal to q, R8 is the residue of a dihydroxy organic compound attached to each boron atom via an oxygen atom, (each R5, R6 and R8 being the same or different. R7 may be derived from a glycol or thioglycol, an alkanolamine or alkoxylated alkanolamine or a 3-6 OH polyol. The hydraulic fluid may also contain an aliphatic or aromatic amine (several specified) and/or small amounts of lubricity agents, corrosion inhbitors, antioxidants of which extensive lists are given. In a typical example, the hydraulic fluid consists of tris (monobutyl ether of diethylene glycol) borate (20 pts.); di-(monoethyl ether of diethylene glycol) nylonate (20 pts.); triethylene glycol dipropionate (10 pts.) and di-amylamine (1 pt.).