Water-based hydraulic fluids comprising dithio-di(aryl carbolic acids)
AssigneeClarient Finance (BVI) Limited
InventorsRainer Kupfer, Carsten Cohrs
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Abstract
The invention relates to water-based hydraulic fluids comprising a) water, b) at least one glycol, a polyglycol, or both, and c) 0.1 to 30 wt % of at least one compound of formula 1, where M is hydrogen, an alkali metal, an alkali earth metal, or ammonia, Ar1 and Ar2 are independently monocyclic or polycyclic aromatic groups that can have substituents or can comprise heteroatoms.
Claims21
A hydraulic fluid comprising
- a) water,
- b) at least one glycol, a polyglycol or both, and
- c) from 0.1 to 30% by weight of at least one compound of the formula 1
- wherein
- M is hydrogen, alkali metal, alkaline earth metal or ammonium,
- Ar1 and Ar2 are each independently mono- or polycyclic aromatic groups which may bear substituents or may contain heteroatoms, and wherein the Ar1 and Ar2 radicals each have only one substituent which is not H apart from the carboxyl group and the sulfide bridge.
A hydraulic fluid comprising
- a) water,
- b) at least one glycol, a polyglycol or both, and
- c) from 0.1 to 30% by weight of at least one compound of the formula 1
- wherein
- M is hydrogen, alkali metal, alkaline earth metal or ammonium, and
- wherein each of the Ar1 and Ar2 radicals are monocyclic aromatic radical of the formula 3
- wherein the free valence indicates the position of the sulfide bridge, and X is a C1- to C4-alkyl group, a nitro group or a halogen atom.
A process for improving the anti-corrosivity or lubricity of a hydraulic fluid, wherein the hydraulic fluid comprises water and at least one glycol, at least one polyglycol or mixtures thereof, comprising the step of adding from 0.1 to 30% by weight of a compound of the formula 1
- in which
- M is hydrogen, alkali metal, alkaline earth metal or ammonium,
- Ar1 and Ar2 are each independently mono- or polycyclic aromatic groups which may bear substituents or may contain heteroatoms, and wherein the Ar1 and Ar2 radicals each bear only one substituent which is not H apart from the carboxyl group and the sulfide bridge to the hydraulic fluid.
A process for improving the anti-corrosivity or lubricity of a hydraulic fluid, wherein the hydraulic fluid comprises water and at least one glycol, at least one polyglycol or mixtures thereof, comprising the step of adding from 0.1 to 30% by weight of a compound of the formula 1
- in which
- M is hydrogen, alkali metal, alkaline earth metal or ammonium,
- and wherein each of the Ar1 and Ar2 radicals are a monocyclic aromatic radical of the formula 3
- wherein the free valence indicates the position of the sulfide bridge, and X is a C1- to C4-alkyl group, a nitro group or a halogen atom to the hydraulic fluid.
Dependencies are inferred from the claim text.