Hydraulic Fluid Compositions and Preparation Thereof

Abstract

A hydraulic fluid composition having excellent oxidation stability prepared from an isomerized base oil is provided. The composition comprising (i) 80 to 99.999 wt. % of a lubricating base oil having consecutive numbers of carbon atoms, less than 10 wt % naphthenic carbon by n-d-M; and (ii) 0.001-20 wt % of at least an additive package. The hydraulic fluid composition meets the performance specifications of at least one of the JCMAS HK and JCMAS HKB standard specifications issued by the Fuels and Lubricants Technical Committee of Japan Construction Mechanization Association (JCMA).

Description

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation-in-part of U.S. patent application Ser. No. 11 / 078,746, filed Mar. 11, 2005; U.S. patent application Ser. No. 11 / 131,611 filed Dec. 21, 2005; and U.S. patent application Ser. No. 11 / 316,310 filed Dec. 21, 2005. This application claims priority to and benefits from the foregoing, the disclosure of which is incorporated herein by reference.TECHNICAL FIELD [0002] The invention relates generally to hydraulic fluid compositions, and more specifically to hydraulic fluid compositions having excellent oxidation stability. BACKGROUND [0003] Hydraulic fluids serve as the power transmission medium in a hydraulic system. They are designed to transmit force and motion in industrial, mobile and non-mobile hydraulic systems such as automobiles, tractors, earthmovers, construction machinery, and hydraulic pumps, etc. In one particular application in recent years, e.g., hydraulic systems in construction machinery, high...

AI Technical Summary

Benefits of technology

[0007] In another aspect, there is provided a method to minimize oxidative degradation of hydraulic fluids for use in construction machinery, the method comprising using a hydraulic fluid composition comprising a lubricating base oil having consecutive numbers of carbon atoms, less than 10 wt % naphthenic carbon by n-d-M, less than 0.10 wt. % olefins and less than 0.05 wt. % aromatics; (ii) 0.001-20 wt % of at least an additive package; wherein the hydraulic fluid composition meets at least one of JACMAS HK and JCMAS HKB specification standards.

Problems solved by technology

The reduced capacity of the reservoir tank for hydraulic fluid and less ventilation at the engine / pump room for noise protection accelerates oxidation and thermal degradation of hydraulic fluids.

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