A functional fluid composition useful as a brake fluid comprising from 0 to 94.99% by weight of alkoxy glycols of borate esters, from 5 to 99.99% by weight of alkoxy glycols, from 0.01 to 5% by weight of alkoxylates of saturated or unsaturated hydroxy-substituted fatty acids such as ricinoleic acid or esters thereof, the hydroxyl group located on the fatty acid side chain being etherified by at least one oxyalkylene unit, and from 0 to 10% by weight of an additive package comprising additives with corrosion inhibition action.

The present invention relates to a functional fluid composition comprising a glycol as a base material and a diamine-based noise reducer. According to the present invention as such, the functional fluid composition comprising a glycol as a base material and a diamine-based noise reducer represented by chemical formula 1 has an excellent noise reducing effect. In addition, the functional fluid composition of the present invention has an excellent metal corrosion inhibiting effect even, by using a diamine-based compound as a noise reducer, when a metal corrosion inhibitor composed of a triazole-based compound without including an amine-based compound is used as a metal corrosion inhibitor.

The present invention relates to a functional fluid composition comprising a glycol as a base material and a monoamine-based noise reducer. According to the present invention as such, the functional fluid composition comprising a glycol as a base material and a monoamine-based noise reducer represented by chemical formula 1 has an excellent noise reducing effect. In addition, the functional fluid composition of the present invention has an excellent metal corrosion inhibiting effect even, by using a monoamine-based compound as a noise reducer, when a metal corrosion inhibitor composed of a triazole-based compound without including an amine-based compound is used as a metal corrosion inhibitor.