Low viscosity functional fluid composition

Abstract Borate-free low viscosity functional fluid composition 5 This invention relates to a functional fluid, comprising (A) from 50 to 85, preferably 60 - 82 wt.-% of alkoxy glycol according to formula (1) CH3 - O - (CH2 - CH2 - O)n -H (1) wherein n is a number from 2 to 5, with the proviso that in at least 30 wt.-% 10 of all compounds according to formula (1) n is 3, and (B) from 1 to 20, preferably 1.5 to 10 wt.-% of alkoxy glycol according to formula (II) R 1 - O - (CH2 - CH 2 - 0)m - H (II) wherein 15 R1 is a C2 to C alkyl residue, m is a number from 2 to 6, with the proviso that in at least 65 wt.-% of all compounds according to formula (II) m is 3, and 20 (C) from 6 to 35, preferably 10 - 25 wt.-% of at least one compound according to formula (Ill) H - O - (CH2 - CH2 - O)k-H (III) wherein k is a number of 2 or higher, with the proviso that in at least 80 wt.-% of all compounds according to formula (Il) k is 2 or 3, (D) at least one additive, selected from the group consisting of corrosion inhibitor, amines, stabilizers, defoamers and lubricants, the fluid comprising at most 3 wt.-% of an ester between boric acid and a 30 glycol or alkyl polyglycol compound.