Patent ID: 6693064
Filing Date: 2004-02-17
Classification: C10M,C10N

Abstract:
A hydraulic fluid composition comprising at least 75% by weight, based on the total composition, of at least one ester formed by the reaction of(i) at least one polyol selected from the group consisting of trimethylol propane, pentaerythritol, neopentyl glycol, di-trimethylol propane, tri-trimethylol propane, di-pentaerythritol, tri-pentaerythritol; with (ii) a mixture of fatty acids consisting of a part (I) selected from the group consisting of straight or branched chain C8 and C10 acids or mixture thereof and a part (II) oleic acid, wherein the ratio of esterified acids (I):(II) is in the range 2:1 to 1:20; and wherein said hydraulic fluid has a viscosity of 7000 mm2/s or less, when measured at âˆ’30Â° C. after being held at âˆ’30Â° C. for 168 hours, and further comprising at least one additive selected from the group consisting of anti-oxidants, viscosity index improvers, anti-wear compounds and anti-foam compounds.