Hydraulic fluid composition

Abstract

A hydraulic lubricating oil composition is provided that contains a synergistic mixture of a polyalkenyl surfactant and a hydrocarbyl amine salt of an alkyl phosphoric acid to provide good demulsibility to the lubricating oil composition and rust resistance to hydraulic systems.

Description

Background Art

[0001] Hydraulic fluid compositions contain various surfactant additives to provide mechanical systems with protection from wear and corrosion. For example, hydraulic fluid compositions include additives to protect mechanical systems from rust. In addition, for hydraulic fluid compositions that are susceptible to water contamination and turbulence, the ability to separate water and oil is important. Therefore, it is desirable to provide hydraulic fluid compositions that provide rust protection as well as excellent demulsibility properties. Summary of the invention

[0002] The present invention provides a fluid composition for use in a hydraulic system, a turbine system, or a circulating oil system. A hydraulic system is typically a device or apparatus in which pressure is applied to a fluid (typically an oil-based fluid) to transfer energy to different parts of the system. Turbine lubricants are typically used to lubricate the gears or other moving parts of a turbine (such as a steam turbine or a gas turbine) (or a turbine system). Circulating oils are typically used to distribute heat to or through a device or apparatus that circulates it.

[0003] The hydraulic fluid composition of the present invention comprises an oil of lubricating viscosity, a polyalkenyl surfactant and a hydrocarbyl amine salt of an alkyl phosphoric acid. In one embodiment, the polyalkenyl surfactant used in the present invention comprises a functional group selected from the group consisting of imide, amide, ester, anhydride or a mixture thereof, for example, the polyalkenyl surfactant may comprise a polyamine polyisobutenyl succinimide, a polyisobutenyl succinic anhydride surfactant or a combination of a polyamine polyisobutenyl succinimide and a polyisobutenyl anhydride. In one embodiment, the hydrocarbyl amine salt of an alkyl phosphoric acid comprises a hydrocarbyl amine salt of an alkyl phosphoric acid, a hydrocarbyl amine salt of a dialkyl phosphoric acid or a mixture thereof. The hydrocarbyl amine salt of an alkyl phosphoric acid may be present in an amount sufficient to deliver 25 ppm to 800 ppm, or 50 ppm to 500 ppm, or 100 ppm to 400 ppm of phosphorus to the hydraulic fluid composition. In addition, the hydraulic fluid composition of the present invention may have an ISO viscosity grade of 68 to 460 or 100 to 220.

[0004] The lubricating composition may also include additional additives as further explained herein.

[0005] The present invention also provides a method of lubricating a hydraulic system or a method of operating the hydraulic system, wherein the method comprises supplying the hydraulic fluid composition as described herein to the hydraulic system.

[0006] Certain features and other aspects of the invention are described in more detail in the following detailed description herein. DETAILED DESCRIPTION

[0007] Oil of lubricating viscosity

[0008] The lubricating composition disclosed herein comprises an oil with lubricating viscosity. Suitable oils include natural lubricating oils and synthetic lubricating oils and mixtures thereof. In a fully formulated lubricant, the oil with lubricating viscosity is usually present in a major amount (i.e., an amount greater than 50% by weight). Typically, the oil with lubricating viscosity is present in an amount of 70% to 99.5% by weight of the entire composition, and often greater than 80% by weight. The oil with lubricating viscosity is usually used as the "base oil" of the lubricant composition and constitutes 100 parts by weight (pbw) of the entire composition, and the pbw ranges of other components are provided in consideration of the 100 pbw base oil. In other embodiments, the pbw ranges of various components (including base oil) are provided so that the pbw sum of all components is 100, and therefore the pbw value is equivalent to the weight percentage value. The pbw ranges provided for the various components described below can be used in any manner, but in most embodiments, they should be understood to be equivalent to weight percentage values.

[0009] Oils with lubricating viscosity may include natural and synthetic oils, oils derived from hydrocracking, hydrogenation and hydrofining, unrefined oils, refined oils and re-refined oils or mixtures thereof. Unrefined oils are oils obtained directly from natural or synthetic sources without (or in small amounts) further purification treatments generally. Refined oils are similar to unrefined oils, except that the refined oils have been further processed in one or more purification steps to improve one or more characteristics. Purification techniques are known in the art, and include solvent extraction, secondary distillation, acid or base extraction, filtration, percolation, etc. Re-refined oils are also referred to as regenerated oils or reprocessed oils, and are obtained by methods similar to those used to obtain refined oils, and are often processed in addition by techniques involving removal of spent additives and oil decomposition products.

[0010] Natural oils useful as the oil of lubricating viscosity include animal oils, vegetable oils (e.g., castor oil, lard oil), mineral lubricating oils (such as liquid petroleum), and solvent-treated or acid-treated mineral lubricating oils of the paraffinic, cycloparaffinic or mixed paraffinic-cycloparaffinic type, and oils derived from coal or shale, or mixtures thereof.

[0011] Synthetic oils of lubricating viscosity include hydrocarbon oils such as polymerized olefins and interpolymerized olefins (e.g., polybutene, polypropylene, propylene isobutylene copolymers); poly(1-hexene), poly(1-octene), poly(1-decene), and mixtures thereof; alkyl-benzenes (e.g., dodecylbenzene, tetradecylbenzene, dinonylbenzene, di-(2-ethylhexyl)-benzene); polyphenyls (e.g., biphenyl, terphenyl, alkylated polyphenyls); alkylated diphenyl ethers and alkylated diphenyl sulfides and derivatives, analogs and homologs thereof or mixtures thereof.

[0012] Another synthetic oil of lubricating viscosity includes polyol esters of polyoxyalkylene polyols that are not hydrocarbon-terminated as disclosed herein, dicarboxylic acid esters, liquid esters of phosphoric acid (e.g., tricresyl phosphate, trioctyl phosphate, and diethyl ester of decanephosphonic acid), or polytetrahydrofuran. Conventional synthetic oils of lubricating viscosity also include those prepared by the Fischer-Tropsch reaction, and can generally be hydroisomerized Fischer-Tropsch hydrocarbons or waxes. In one embodiment, the oil of lubricating viscosity can be prepared by the Fischer-Tropsch gas-liquid synthesis procedure, as well as other gas-liquid oils.

[0013] Oil with lubricating viscosity can also be defined as specified in the American Petroleum Institute (API) Base Oil Interchangeability Guidelines. Five types of base oils are as follows: Class I (sulfur content> 0.03 weight % and / or < 90 weight % saturates, viscosity index 80-120); Class II (sulfur content< 0.03 weight %, and> 90 weight % saturates, viscosity index 80-120); Class III (sulfur content< 0.03 weight %, and> 90 weight % saturates, viscosity index> 120); Class IV (all polyalphaolefins (PAO), such as PAO-2, PAO-4, PAO-5, PAO-6, PAO-7 or PAO-8); and Class V. In some embodiments, the oil with lubricating viscosity includes API Class I, Class II, Class III, Class IV, Class V oil or a mixture thereof. In other embodiments, the oil with lubricating viscosity is API Class I, Class II, Class III, Class IV oil or a mixture thereof. In other embodiments, the oil with lubricating viscosity is often API II class, III class or IV class oil or their mixture.In one embodiment, the oil with lubricating viscosity comprises I class base oil or is composed of I class base oil.In another embodiment, the oil with lubricating viscosity comprises II class base oil or is composed of II class base oil.In another embodiment, the oil with lubricating viscosity comprises III class base oil or is composed of III class base oil.In addition, in one embodiment, the oil with lubricating viscosity comprises IV class base oil or is composed of IV class base oil.

[0014] The various oils of lubricating viscosity described may be used alone or in combination. The amount of oil of lubricating viscosity used is in the range of about 70% to about 99.5% by weight of the lubricant composition, in another embodiment, in the range of about 75% to about 98% by weight of the lubricant composition, and in another embodiment, in the range of about 88% to about 97% by weight of the lubricant composition.

[0015] In a concentrate composition, typically the amount of additives and other components remains the same, but the amount of oil of lubricating viscosity is reduced in order to make the composition more concentrated and more efficiently stored and / or transported. One skilled in the art will be able to readily adjust the amount of oil of lubricating viscosity present to provide a concentrate and / or additive composition.

[0016] Surfactants

[0017] The hydraulic fluid composition of the present invention also includes a polyolefin surfactant. Surfactants that may be included in the composition include those surfactants having an oil-soluble polymeric hydrocarbon backbone and having functional groups that can associate with particles to be dispersed in oil. Exemplary functional groups include amine, alcohol, amide, imide, anhydride and ester polar moieties, which are often connected to the polymer backbone via a bridging group. Suitable surfactants include polyetheramines, borated succinimides, non-borated succinimides, Mannich reaction products of dialkylamines, aldehydes and hydrocarbyl-substituted phenols, or combinations thereof. The surfactant is included in the hydraulic fluid composition of the present invention in an amount of 100 ppm to 2500 ppm.

[0018] In one embodiment, the surfactant comprises a dispersant. Exemplary dispersants include polyalkylene succinimides as described in U.S. Pat. Nos. 5,851,965, 5,853,434, and 5,792,729; amines as described in U.S. Pat. Nos. 3,219,666, 3,565,804, and 5,633,326; anhydrides as described in U.S. Pat. Nos. 4,234,435, 3,172,892, 3,215,707, 3,361,673, and 3,401,118; ashless succinimide dispersants as described in U.S. Pat. Nos. 4,234,435 and 4,636,322; Mannich dispersants as described in U.S. Pat. Nos. 3,697,574 and 3,736,357; Koch dispersants as described in U.S. Pat. Nos. 5,936,041, 5,643,859, and 5,627,259.

[0019] In one embodiment, the surfactant comprises or consists of a polyamine polyisobutenyl succinimide. In another embodiment, the surfactant comprises or consists of a polyisobutenyl succinic anhydride surfactant. In another embodiment, the surfactant comprises or consists of a mixture of a polyamine polyisobutenyl succinimide and a polyisobutenyl succinic anhydride.

[0020] Alkylamine salts of alkylphosphonic acids

[0021] The hydraulic fluid composition of the present invention also includes a hydrocarbylamine salt of an alkylphosphoric acid. Examples of suitable compounds include hydrocarbylamine salts of alkylphosphoric acids, hydrocarbylamine salts of dialkylphosphoric acids, hydrocarbylamine salts of dialkyldithiophosphoric acids, or mixtures thereof.

[0022] Suitable hydrocarbyl amine salts of alkyl phosphoric acids can be represented by the following formula:

[0023]

[0024] Where R 26 and R 27 are independently hydrogen, an alkyl chain or a hydrocarbon group, typically R 26 and R 27 At least one of R is a hydrocarbon group. 26 and R 27 Contains 4 to 30, or 8 to 25, or 10 to 20, or 13 to 19 carbon atoms. 28 , R 29 and R 30 R is independently hydrogen, an alkyl branched or straight chain having 1 to 30, or 4 to 24, or 6 to 20, or 10 to 16, or 12 to 14 carbon atoms. 28 , R 29 and R 30 are independently hydrogen, a branched or straight alkyl chain, or R 28 , R 29 and R 30 At least one or both of them are hydrogen.

[0025] Applicable to R 28 , R 29 and R 30 Examples of alkyl groups include butyl, sec-butyl, isobutyl, tert-butyl, pentyl, n-hexyl, sec-hexyl, n-octyl, 2-ethyl, hexyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, octadecenyl, nonadecyl, eicosyl, or mixtures thereof.

[0026] In one embodiment, the hydrocarbyl amine salt of an alkyl phosphoric acid is C 14 To C 18 Alkylated phosphoric acid 81R (produced and sold by Rohm and Haas), the 81R is C 11 To C 14 A mixture of tertiary alkyl primary amines.

[0027] Hydrocarbyl amine salts of dialkyl dithiophosphoric acid may include heptyl or octyl or nonyl dithiophosphoric acid with ethylenediamine, morpholine or 81R or a mixture thereof.

[0028] The hydrocarbyl amine salt of an alkyl phosphoric acid is present in the hydraulic fluid composition in an amount sufficient to deliver 25 ppm to 800 ppm of phosphorus to the hydraulic fluid composition. In some embodiments, the hydrocarbyl amine salt of an alkyl phosphoric acid is present in the hydraulic fluid composition in an amount sufficient to deliver 50 ppm to 500 ppm, or even 100 ppm to 400 ppm, or even 300 ppm to 400 ppm of phosphorus to the hydraulic fluid composition.

[0029] Other additives

[0030] The hydraulic fluid composition of the present invention may be in the form of a concentrate and / or a fully formulated lubricant. If the lubricant composition of the present invention (including the additives disclosed herein) is in the form of a concentrate (which may be combined with additional oils to form a finished lubricant in whole or in part), the weight ratio of these additives to the oil of lubricating viscosity and / or to the diluent oil comprises a range of 1:99 to 99:1 or 80:20 to 10:90.

[0031] In addition to the above-mentioned additives, the hydraulic fluid composition may also contain one or more additional other additives. In some embodiments, the additional additives may include ashless antiwear additives other than the above-mentioned hydrocarbyl amine salts of alkyl phosphoric acid, antioxidants, corrosion inhibitors, rust inhibitors, foam inhibitors, demulsifiers, metal deactivators, friction modifiers, metal-containing detergents, emulsifiers, pour point depressants, viscosity modifiers, or any combination thereof.

[0032] In one embodiment, the hydraulic fluid of the present invention comprises a metal-free phosphorus antiwear agent, which is different from the above-mentioned hydrocarbyl amine salt of an alkyl phosphoric acid. Examples of such suitable antiwear agents include tartrates, tartrimides, oil-soluble amine salts of phosphorus compounds; sulfided olefins; phosphites (such as dibutyl phosphite or dioleyl phosphite); phosphonates; compounds containing thiocarbamates, such as thiocarbamates, thiocarbamates, thiocarbamates, alkylene-coupled thiocarbamates, bis(S-alkyldithiocarbamoyl)disulfides, and oil-soluble phosphorus amine salts. In one embodiment, the metal-free phosphorus antiwear agent comprises or consists of (thio)phosphates. As used herein, the term (thio)phosphate is understood to include phosphates, thiophosphates, or mixtures thereof.

[0033] The phosphorus compound that can be used in the present invention may include a triaryl phosphate or a triaryl thiophosphate represented by the following formula (1):

[0034]

[0035] In formula (1), R is a hydrogen atom or an alkyl group having 3 to 9 (e.g., 3, 4, 5, 6, 7, 8, 9) carbon atoms or a combination of carbon atoms thereof, and X is an oxygen atom or a sulfur atom. In formula (1), the three R groups may be the same or different from each other. Examples of alkyl groups having 4 or fewer carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and tert-butyl.

[0036] Examples of the phosphorus compound represented by formula (1) include triphenyl phosphate, tricresyl phosphate, triphenyl thiophosphate, tricresyl thiophosphate, and butylated triphenyl thiophosphate.

[0037] Another example of the phosphorus compound that can be used in the present invention is represented by the following formula (2).

[0038]

[0039] In formula (2), R 1 represents a straight or branched chain alkylene group having 1 to 8 carbon atoms, R 2 and R 3 Each represents a hydrocarbon group having 3 to 20 carbon atoms, and X 2 and X 3 Each independently represents an oxygen atom or a sulfur atom.

[0040] In one embodiment, R 1 It may be a linear or branched alkylene group having 1 to 8 carbon atoms, more preferably a linear or branched alkylene group having 2 to 4 carbon atoms, and further preferably a branched alkylene group. Specifically, R 1 Preferably, for example, -CH 2 CH 2 —、—CH 2 CH(CH 3 )—、—CH 2 CH(CH 2 CH 3 )—or—CH 2 CH(CH 2 CH 2 CH 3 )—, and more preferably —CH 2 CH(CH 3 )—or—CH 2 CH(CH 3 )CH 2 —.

[0041] In one embodiment, R 2 To R 3Each preferably represents a straight-chain or branched alkyl group having 3 to 8 carbon atoms, and more preferably a straight-chain or branched alkyl group having 4 to 6 carbon atoms. Specifically, R 2 to R 3 each preferably is selected from the group consisting of: propyl, isopropyl, butyl, isobutyl, pentyl, isopentyl, hexyl, 2-ethylbutyl, 1-methylpentyl, 1,3-dimethylbutyl, and 2-ethylhexyl.

[0042] In one embodiment, X 2 and X 3 both represent oxygen atoms. In another embodiment, X 2 and X 3 both represent sulfur atoms. In another embodiment, X 2 is oxygen and X 3 is sulfur, and in another embodiment, X 2 is sulfur and X 3 is oxygen.

[0043] Another phosphorus compound useful in the present invention includes a thiophosphate compound represented by the following formula (3).

[0044]

[0045] In formula (3), R 4 , R 5 and R 7 are each independently a straight-chain or branched saturated or unsaturated aliphatic hydrocarbon group having 1 to 18 carbon atoms or a branched or unbranched saturated or unsaturated cyclic hydrocarbon group having 5 to 18 carbon atoms. R 6 is a straight-chain or branched alkylene group having 1 to 8 carbon atoms, and X 4 and X 5 are each independently an oxygen atom or a sulfur atom. In one embodiment of formula (3), there is at least one sulfur atom.

[0046] In one embodiment, X 4 and X 5 both represent oxygen atoms. In another embodiment, X 4 and X 5 both represent sulfur atoms. In another embodiment, X 4 is oxygen and X 5 is sulfur, and in another embodiment, X 4 is sulfur and X 5 is oxygen.

[0047] In one embodiment, the metal-free antiwear agent of the present invention may be selected from methyl 3-((dialkoxythiophosphoryl)thio)propanoate, 3-((diisobutoxythiophosphoryl)thio)-2-methylpropanoic acid and mixtures thereof having mixed C4 / C5 alkoxy groups.

[0048] In another embodiment, the hydraulic fluid of the present invention may also include a metal-containing antiwear agent, which may include a metal dialkyl dithiophosphate. Typically, the metal dialkyl dithiophosphate may be zinc dialkyl dithiophosphate (ZDDP) or a mixture thereof. Zinc dialkyl dithiophosphates are known in the art.

[0049] The hydraulic fluid of the present invention will contain up to 800 ppm phosphorus. When included in the hydraulic fluid of the present invention, the antiwear additive may be present in an amount sufficient to provide 10 ppm to 500 ppm phosphorus, or even 50 ppm to 500 ppm phosphorus, or even 300 ppm to 400 ppm phosphorus by weight. If the antiwear agent is the only phosphorus-containing compound present in the hydraulic fluid, such compound will be present in an amount sufficient to deliver the desired amount of phosphorus. In one embodiment, the antiwear agent is metal-free, particularly zinc-free. In some embodiments, the hydraulic fluid composition is substantially zinc-free, or contains less than 10 ppm or even less than 5 ppm of zinc.

[0050] The hydraulic fluid composition may also contain an antioxidant. If present, the antioxidant may be present at 0 wt % to 4.0 wt %, or 0.02 wt % to 3.0 wt %, or 0.03 wt % to 1.5 wt % of the hydraulic fluid composition.

[0051] Antioxidants include diarylamines, alkylated diarylamines, hindered phenols, molybdenum compounds (such as molybdenum dithiocarbamates), hydroxy thioethers, trimethyl polyquinolines (eg, 1,2-dihydro-2,2,4-trimethylquinoline), or mixtures thereof.

[0052] The diarylamine or alkylated diarylamine may be phenyl-α-naphthylamine (PANA), alkylated diphenylamine or alkylated phenylnaphthylamine or a mixture thereof. The alkylated diphenylamine may include dinonylated diphenylamine, nonyldiphenylamine, octyldiphenylamine, dioctylated diphenylamine, didecylated diphenylamine, decyldiphenylamine, benzyldiphenylamine and a mixture thereof. In one embodiment, the diphenylamine may include nonyldiphenylamine, dinonyldiphenylamine, octyldiphenylamine, dioctyldiphenylamine or a mixture thereof. In one embodiment, the alkylated diphenylamine may include nonyldiphenylamine or dinonyldiphenylamine. The alkylated diarylamine may include octyl, dioctyl, nonyl, dinonyl, decyl or didecylphenylnaphthylamine. In one embodiment, the diphenylamine is alkylated with benzene and tert-butyl substituents.

[0053] Hindered phenol antioxidants often contain sec-butyl and / or tert-butyl groups as sterically hindering groups. The phenol group can typically be further substituted with a hydrocarbyl group (typically a straight or branched alkyl group) and / or a bridging group connected to a second aromatic group. Examples of suitable hindered phenol antioxidants include 2,6-di-tert-butylphenol, 4-methyl-2,6-di-tert-butylphenol, 4-ethyl-2,6-di-tert-butylphenol, 4-propyl-2,6-di-tert-butylphenol or 4-butyl-2,6-di-tert-butylphenol or 4-dodecyl-2,6-di-tert-butylphenol. In one embodiment, the hindered phenol antioxidant can be an ester and can include, for example, Irganox from BASF GmbH. TM L-135. A more detailed description of suitable ester-containing hindered phenol antioxidant chemistry is found in US Pat. No. 6,559,105.

[0054] The antioxidant may include a substituted hydrocarbyl monosulfide represented by the following Formula 4:

[0055]

[0056] Where R 6 It may be a saturated or unsaturated branched or straight chain alkyl group having 8 to 20 carbon atoms; R 7 , R 8 , R 9 and R 10 is independently hydrogen or an alkyl group containing 1 to 3 carbon atoms. In some embodiments, the substituted hydrocarbyl monosulfide comprises n-dodecyl-2-hydroxyethyl sulfide, 1-(tert-dodecylthio)-2-propanol, or a combination thereof. In some embodiments, the substituted hydrocarbyl monosulfide is 1-(tert-dodecylthio)-2-propanol.

[0057] Defoamers, also known as foam inhibitors, are known in the art and include organosiloxanes and non-silicone foam inhibitors. Examples of organosiloxanes include dimethylsiloxanes and polysiloxanes. Examples of non-silicone foam inhibitors include copolymers of ethyl acrylate and 2-ethylhexyl acrylate; copolymers of ethyl acrylate, 2-ethylhexyl acrylate and vinyl acetate; polyethers; polyacrylates and mixtures thereof. In some embodiments, the defoamer is a polyacrylate. The defoamer may be present in the composition at 0 wt % to 0.1 wt %, or 0.001 wt % to 0.012 wt %, or 0.004 wt %, or even 0.001 wt % to 0.003 wt %.

[0058] Demulsifier is known in the art and includes derivatives of propylene oxide, ethylene oxide, polyoxyalkylene alcohol, alkylamine, amino alcohol, diamine or polyamines reacted continuously with ethylene oxide or substituted ethylene oxide or their mixture. The example of demulsifier includes polyethylene glycol, polyethylene oxide, polypropylene oxide, (ethylene oxide-propylene oxide) polymer and their mixture. In some embodiments, demulsifier is polyether. In one embodiment, demulsifier can be an alkoxylated phenolic resin blend. This blend can include formaldehyde polymers with 4-nonylphenol, ethylene oxide and propylene oxide and formaldehyde polymers with 4-nonylphenol ethylene oxide. Demulsifier can be present in the composition with 0 weight % to 0.1 weight % or 0.002 weight % to 0.012 weight %.

[0059] Pour point depressants are known in the art and include esters of maleic anhydride-styrene copolymers, polymethacrylates; polyacrylates; polyacrylamides; condensation products of halogenated paraffins and aromatic compounds; carboxylic acid vinyl ester polymers; and terpolymers of dialkyl fumarates, vinyl esters of fatty acids, ethylene-vinyl acetate copolymers, alkylphenol formaldehyde condensation resins, alkyl vinyl ethers, and mixtures thereof. In one embodiment, the polymethacrylate pour point depressant may be present in an amount of 0% to 0.4% or 0.005% to 0.3% by weight of the hydraulic fluid.

[0060] The metal deactivator may be selected from derivatives of benzotriazole, 1,2,4-triazole, benzimidazole, 2-alkyldithiobenzimidazole, 2-alkyldithiobenzothiazole or dithiothiadiazole. Examples of such derivatives include 2,5-dithio-1,3,4-thiadiazole or oligomers thereof, 2,5-dithio-1,3,4-thiadiazole substituted with a hydrocarbyl group, 2,5-dithio-1,3,4-thiadiazole substituted with a hydrocarbylsulfide or oligomers thereof. Oligomers of 2,5-dithio-1,3,4-thiadiazole substituted with a hydrocarbyl group are generally oligomers of two or more thiadiazole units formed by forming sulfur-sulfur bonds between 2,5-dithio-1,3,4-thiadiazole units. Examples of suitable thiadiazole compounds include at least one of dimercaptothiadiazole, 2,5-dimercapto-[1,3,4]-thiadiazole, 3,5-dimercapto-[1,2,4]-thiadiazole, 3,4-dimercapto-[1,2,5]-thiadiazole or 4-5-dimercapto-[1,2,3]-thiadiazole. Generally, readily available materials such as 2,5-dimercapto-1,3,4-thiadiazole or hydrocarbyl-substituted 2,5-dimercapto-1,3,4-thiadiazole or hydrocarbylsulfide-substituted 2,5-dimercapto-1,3,4-thiadiazole are generally utilized. In various embodiments, the number of carbon atoms on the hydrocarbyl substituent group includes 1 to 30, 2 to 25, 4 to 20, 6 to 16, or 8 to 10. The 2,5-dimercapto-1,3,4-thiadiazole can be 2,5-dioctyldithio-1,3,4-thiadiazole or 2,5-dinonyldithio-1,3,4-thiadiazole. Metal deactivators can also be described as corrosion inhibitors.

[0061] The metal deactivator may be present in the range of 0 wt % or 0.001 wt % to 0.1 wt %, 0.01 wt % to 0.04 wt %, or 0.015 wt % to 0.03 wt % of the lubricating oil composition. The metal deactivator may also be present in the composition at 0.002 wt % or 0.004 wt % to 0.02 wt %. The metal deactivator may be used alone or as a mixture thereof.

[0062] In one embodiment, the present invention provides a hydraulic fluid composition further comprising a metal-containing detergent. In some embodiments, the metal-containing detergent may be a calcium or magnesium detergent. In one embodiment, the metal-containing detergent may also be a high-based detergent having a total base number in the range of 30 to 500 mg KOH / g equivalent. In another embodiment, the metal-containing detergent may be a neutral detergent having a total base number of 0 to 30, or even 0 to 10, or even 30 or less, or even 10 or less mg KOH / g equivalent.

[0063] The metal-containing detergent may be selected from non-sulfur-containing phenates, sulfur-containing phenates, sulfonates, salicylates, salicylates, and mixtures thereof or their borated equivalents. The detergent may be borated with a borated agent such as boric acid, such as a borated overbased calcium or magnesium sulfonate detergent, or mixtures thereof. The detergent may be present in an amount of 0 wt % to 5 wt %, or 0.001 wt % to 1.5 wt %, or 0.005 wt % to 1 wt %, or 0.01 wt % to 0.5 wt % of the hydraulic composition.

[0064] In one embodiment, the hydraulic fluid composition of the present invention includes a calcium detergent. In such embodiments, the calcium detergent may be present in the hydraulic fluid composition in an amount that delivers 5 ppm to 200 ppm, or 10 ppm to 150 ppm, or 15 ppm to 100 ppm calcium to the hydraulic fluid composition.

[0065] In one embodiment, all additives used in the hydraulic fluid composition may be ashless. In another embodiment, the lubricating composition may be free of additives containing transition metals. In yet another embodiment, the lubricating composition may contain additives in which calcium is the only metal.

[0066] In one embodiment, the lubricants disclosed herein may contain at least one friction modifier. The friction modifier may be present at 0 wt % to 3 wt %, or 0.02 wt % to 2 wt %, or 0.05 wt % to 1 wt % of the lubricant composition.

[0067] Examples of suitable friction modifiers include long chain fatty acid derivatives of amines, fatty acid esters or fatty epoxides; fatty imidazolines, such as condensation products of carboxylic acids and polyalkylene polyamines; amine salts of alkyl phosphoric acids; fatty phosphonates; fatty phosphites; borated phospholipids, borated fatty epoxides; glycerides; borated glycerides; fatty amines; alkoxylated fatty amines; borated alkoxylated fatty amines; hydroxy and polyhydroxy fatty amines; hydroxyalkylamides; metal salts of fatty acids; metal alkyl salicylates; fatty oxazolines; fatty ethoxylated alcohols; condensation products of carboxylic acids and polyalkylene polyamines; or reaction products from fatty carboxylic acids with guanidine, aminoguanidine, urea or thiourea and their salts.

[0068] As used herein, the term "fatty alkyl" or "fatty" with respect to friction modifiers means a carbon chain having 8 to 22 carbon atoms, typically a straight carbon chain. Alternatively, the fatty alkyl group may be a monobranched alkyl group, wherein the branching is typically at the beta position. Examples of monobranched alkyl groups include 2-ethylhexyl, 2-propylheptyl, or 2-octyldodecyl.

[0069] The hydraulic fluid composition may also contain one or more viscosity modifiers. Suitable viscosity modifiers for the present invention (often referred to as viscosity index improvers) include polymeric materials including styrene-butadiene rubber, olefin copolymers, hydrogenated styrene-isoprene polymers, hydrogenated free radical isoprene polymers, poly (methyl) acrylates, polyalkyl styrenes, hydrogenated alkenyl aryl conjugated diene copolymers, esters of maleic anhydride-styrene copolymers or mixtures thereof. In some embodiments, the viscosity modifier is poly (methyl) acrylate, olefin copolymers or mixtures thereof. The viscosity modifier may be present in 0% to 10% by weight, 0.5% to 8% by weight, 1% to 6% by weight of the lubricant.

[0070] An exemplary hydraulic fluid may have a formulation as defined in the following table. All additives are expressed on an oil-free basis.

[0071] Exemplary Hydraulic Lubricant Compositions

[0072]

[0073] Industrial Applications

[0074] According to one aspect of the exemplary embodiment, the hydraulic fluid is used in a hydraulic system, a turbine system, or other circulating oil system. A hydraulic system may be a device or apparatus in which a hydraulic fluid transfers energy to different parts of a system by hydraulic force. Turbine lubricants are typically used to lubricate gears or other moving parts of a turbine (such as a steam turbine or a gas turbine) (or a turbine system). Circulating oils are typically used to distribute heat to or through a device or apparatus that circulates it.

[0075] Viscosity grades commonly used for hydraulic oils are ISO 10, 15, 22, 32, 46, 68, 100 and 150 (cSt). The viscosity of each grade is the kinematic viscosity at 40°C + / - 10%, as measured by ASTM D445 or ISO 3104. Thus, an ISO 46 of 46 cSt at 40°C may have a kinematic viscosity of 41.4 cSt to 50.6 cSt at 40°C. The ISO viscosity classification system is defined in ISO 3448. Exemplary viscosity grades are listed in the following table:

[0076]

[0077] Thus, in some embodiments, the lubricating composition may have an ISO viscosity grade (VG) of 10, 15, 22, 32, 46, 68, 100, 150, 220, 320, 460, or 680 (cSt) lubricant. In other embodiments, the lubricating composition may have an ISO VG of 68 cSt to 460 cSt, or 100 cSt or 420 cSt.

[0078] The present invention provides a method of lubricating a hydraulic system, wherein the method comprises supplying a hydraulic fluid composition as described herein to the hydraulic system. The present invention also provides a method of operating a hydraulic system, wherein the method comprises supplying a hydraulic fluid composition as described herein to the hydraulic system. The present invention also includes the use of the hydraulic fluid composition as described herein for lubricating a hydraulic system.

[0079] Example

[0080] Exemplary hydraulic fluid compositions were prepared and evaluated as outlined in the following Examples. Unless otherwise noted, all treatment grades were oil-free (ie, active).

[0081] A base formulation containing dispersant, ashless antioxidant, ashless phosphorus antiwear agent, triazole corrosion inhibitor and other typical hydraulic additives was prepared for top treatment with the phosphorus additive of the present invention (Table 1).

[0082] Table 1 - Basic Hydraulic Additive Package 1

[0083] additive BF1 <![CDATA[Polyisobutenyl succinimide dispersant 2 > 5.9 Polyisobutenyl succinic anhydride 5.9 <![CDATA[Ashless antioxidant 3 > 47.0 <![CDATA[Dithiophosphate antiwear agent 4 > 7.0 <![CDATA[Alkyl dithiocarbamate 5 > 5.9 Polyether demulsifier 1.5 Olein 11.8 <![CDATA[Triazole corrosion inhibitor 6 > 5.9 Defoaming Additives 0.6 Diluent Oil 8.5

[0084] 1. Unless otherwise specified, treatment rates are oil-free

[0085] 2. Preparation from intermediate succinate PIB and polyaromatic polyamine

[0086] 3. Combination of alkylated diphenylamine and hindered phenol

[0087] 4. Combinations of hydrocarbon esters of di(C4 / C5) dithiophosphoric acids

[0088] 5. Methylene bis(dibutyl dithiocarbamate)

[0089] 6. Combination of alkylated benzotriazole and substituted 1,2,4-triazole

[0090] A series of hydraulic fluid formulations of several ISO viscosity grades were prepared to evaluate demulsibility and corrosion resistance. Example formulations (Table 2) were prepared by top treating fully formulated hydraulic fluids with the additives to be evaluated. The treatment rates of the amine phosphates were also varied.

[0091] Table 2 - Hydraulic Lubricant Composition

[0092]

[0093]

[0094] 1. Unless otherwise specified, treatment rates are oil-free

[0095] 2. Group II base oil with a kinematic viscosity of 12 cSt at 100°C

[0096] 3. Group II base oil with kinematic viscosity of 11.5 cSt at 100C

[0097] 4. Group II base oil with kinematic viscosity of 6.4 cSt at 100°C

[0098] 5. Type I bright stock with a kinematic viscosity of 32 cSt at 100°C

[0099] 6. Mixed salts of 2-ethylhexylamine and mono- and di-(isooctyl)phosphoric acid

[0100] 7. Mixed salts of C12-14-tertiary alkyl (mono)amines and combinations of mono- and di-(C14-18 fatty alkyl)phosphoric acids

[0101] The effects of various concentrations of formulation components were also evaluated. The treatment rates of the base formulation were varied and the amine phosphate additives of the present invention were top treated (Table 3).

[0102] Table 3 - Hydraulic Lubricant Composition

[0103]

[0104]

[0105] 1. Unless otherwise specified, treatment rates are oil-free

[0106] 2. Group II base oil with a kinematic viscosity of 12 cSt at 100°C

[0107] 3. Group II base oil with kinematic viscosity of 11.5 cSt at 100C

[0108] 4. Type I bright oil with kinematic viscosity of 32 cSt at 100°C

[0109] 5. Mixed salt of 2-ethylhexylamine with mono- and di-(isooctyl)phosphoric acid

[0110] Lubricant formulations are evaluated for protection of hydraulic systems, with particular emphasis on wear protection, corrosion protection, and demulsification. Corrosion protection (or rust protection) is evaluated in a mineral oil rust protection test performed according to ASTM D665B. Demulsification is determined via several tests, including the Standard Test Method for Water Separability of Petroleum and Synthetic Fluids (according to ASTM D1401) and the Demulsification Properties Test for Lubricating Oils (according to ASTM D2711 Procedure B). The test results are summarized below (Table 4).

[0111] Table 4 – Demulsibility Test

[0112]

[0113] 1. Average of 2 tests

[0114] 2. Average of 3 tests

[0115] Table 4 (continued)

[0116]

[0117] The data demonstrate that the addition of amine phosphates to lubricating compositions results in increased demulsibility, i.e., a more rapid reduction in emulsion volume. This phenomenon is demonstrated at various viscosity grades at different additive treat rates.

[0118] As used herein, "substantially free" means that the amount of the contemplated substance is below an amount that would affect the relevant properties of the fluid in a measurable manner. "Substantially free" may also mean that the contemplated substance is not intentionally added to the composition, but the presence of such materials as contaminants is not excluded. "Substantially free" may also mean that the contemplated substance may be present in an amount below the detection limit of a standard test method now known or later developed by one skilled in the art. In some embodiments, "substantially free" may mean less than 10 ppm by weight or even less than 5 ppm by weight.

[0119] It is known that some of the above-mentioned substances may interact in the final formulation so that the components of the final formulation may be different from those initially added. The products thus formed, including the products formed by using the lubricant composition of the present invention in its intended use, may not be susceptible to easy description. However, all such modifications and reaction products are included within the scope of the present invention. The present invention includes lubricating compositions prepared by mixing the above-mentioned components.

[0120] Each file mentioned above is incorporated herein by reference.Unless in the examples or otherwise clearly indicated, all numerical values ​​of the amount of a given substance, reaction conditions, molecular weight, number of carbon atoms, etc., in this specification sheet should be understood to be modified by the word "about".Unless otherwise indicated, each chemical or composition mentioned herein should be interpreted as a commercial grade material, which may contain isomers, by-products, derivatives and other such materials generally understood to be present in the commercial grade. However, unless otherwise indicated, the amount of each chemical component does not include any solvent or diluent oil, which may be present in commercial materials generally.It should be understood that the upper and lower limits of the amount, range and ratio described herein can be independently combined.Similarly, the scope and amount of each element of the present invention can be used together with the scope or amount of any other element.

[0121] Although the present invention has been explained with respect to its preferred embodiment, it should be understood that various modifications thereof will become apparent to those skilled in the art upon reading this specification. Therefore, it should be understood that the invention disclosed herein is intended to cover these modifications falling within the scope of the appended claims.

Claims

1. A hydraulic fluid composition, comprising: oil of lubricating viscosity; a polyalkenyl surfactant in an amount of 100 ppm to 2500 ppm; and Alkylamine salts of alkylphosphonic acids.

2. The hydraulic fluid composition of claim 1, wherein the polyalkylene surfactant comprises a functional group selected from the group consisting of imide, amide, ester, anhydride, or a mixture thereof.

3. A hydraulic fluid composition according to any preceding claim, wherein the polyalkylene-based surfactant comprises or consists of a polyamine polyisobutenyl succinimide.

4. The hydraulic fluid composition of claim 3, wherein the composition contains less than 1500 ppm of the polyamine polyisobutenyl succinimide.

5. The hydraulic fluid composition of claim 1 or 2, wherein the polyalkenyl surfactant comprises or consists of a polyisobutenyl succinic anhydride surfactant.

6. A hydraulic fluid composition according to any preceding claim, wherein the polyalkenyl surfactant comprises or consists of a mixture of polyamines polyisobutenyl succinimides and polyisobutenyl anhydrides.

7. A hydraulic fluid composition according to any preceding claim, wherein the hydrocarbylamine salt of an alkyl phosphoric acid comprises a hydrocarbylamine salt of an alkyl phosphoric acid, a hydrocarbylamine salt of a dialkyl phosphoric acid, or a mixture thereof.

8. A hydraulic fluid composition according to any preceding claim, wherein the hydrocarbyl amine salt of an alkyl phosphoric acid has the formula: Where R 26 and R 27 are independently hydrogen or an alkyl or hydrocarbyl chain containing 4 to 30, or 8 to 25, or 10 to 20, or 13 to 19 carbon atoms, and R 28 , R 29 and R 30 Independently hydrogen, alkyl branched or straight alkyl chain having 1 to 30, or 4 to 24, or 6 to 20, or 10 to 16 carbon atoms.

9. The hydraulic fluid composition according to claim 8, wherein R 28 , R 29 and R 30 Each is independently a group selected from the following: butyl, sec-butyl, isobutyl, tert-butyl, pentyl, n-hexyl, sec-hexyl, n-octyl, 2-ethyl, hexyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, octadecenyl, nonadecyl, eicosyl or a mixture thereof.

10. A hydraulic fluid composition according to any preceding claim wherein the hydrocarbyl amine salt of an alkyl phosphoric acid is present in an amount sufficient to deliver 25 ppm to 800 ppm, or 50 ppm to 500 ppm, or 100 ppm to 400 ppm phosphorus to the hydraulic fluid composition.

11. A hydraulic fluid composition according to any preceding claim, wherein the hydraulic fluid composition has an ISO viscosity grade of 68 to 460 or 100 to 220.

12. A hydraulic fluid composition according to any preceding claim further comprising an ashless antiwear additive, wherein the ashless antiwear additive is different from the hydrocarbyl amine salt of an alkyl phosphoric acid.

13. The hydraulic fluid composition of claim 12, wherein the ashless antiwear additive comprises a dithiophosphate.

14. A hydraulic fluid composition according to any preceding claim, wherein the hydraulic fluid composition contains up to 800 ppm phosphorus, or from 25 ppm to 800 ppm phosphorus, from 100 ppm to 400 ppm phosphorus, or from 300 ppm to 400 ppm phosphorus.

15. A hydraulic fluid composition according to any preceding claim, wherein the lubricating composition further comprises 0 wt% to 4 wt% or 0.02 wt% to 3 wt% or 0.03 wt% to 1.5 wt% of an antioxidant.

16. The hydraulic fluid composition of claim 15, wherein the antioxidant is selected from the group consisting of diarylamines, alkylated diarylamines, hindered phenols, molybdenum compounds, hydroxy thioethers, trimethyl polyquinolines, or mixtures thereof.

17. A hydraulic fluid composition according to any preceding claim further comprising up to 0 to 5 wt% or 0.001 to 1.5 wt% or 0.005 to 1 wt% or 0.01 to 0.5 wt% of a metal-containing detergent.

18. The hydraulic fluid composition of claim 17, wherein the metal-containing detergent is a calcium detergent or a magnesium detergent or a mixture thereof.

19. The hydraulic fluid composition of claim 17 or 18, wherein the metal-containing detergent is selected from the group consisting of phenates, sulfonates, salicylate alkoxides, salicylates, or mixtures thereof.

20. The hydraulic fluid composition of any one of claims 17 to 19, wherein the metal-containing detergent comprises a calcium detergent, and wherein the calcium detergent is present in an amount to deliver 5 ppm to 200 ppm, or 5 ppm to 150 ppm, or 5 ppm to 100 ppm calcium to the hydraulic fluid composition.

21. A hydraulic fluid composition according to any preceding claim further comprising 0 to 3 wt% or 0.02 to 2 wt% or 0.05 to 1 wt% of a friction modifier.

22. The hydraulic fluid composition of claim 21, wherein the friction modifier is selected from the group consisting of: long chain fatty acid derivatives of amines, fatty esters or fatty epoxides; fatty imidazolines; amine salts of alkyl phosphoric acids; fatty phosphonates; fatty phosphites; borated phospholipids, borated fatty epoxides; glycerides; borated glycerides; fatty amines; alkoxylated fatty amines; borated alkoxylated fatty amines; hydroxy and polyhydroxy fatty amines; hydroxyalkylamides; metal salts of fatty acids; metal salts of alkyl salicylates; fatty oxazolines; fatty ethoxylated alcohols; condensation products of carboxylic acids with polyalkylene polyamines; or Reaction products of fatty carboxylic acids with guanidine, aminoguanidine, urea or thiourea and salts thereof, or mixtures thereof.

23. A hydraulic fluid composition according to any preceding claim further comprising 0 to 10 wt%, 0.5 to 8 wt%, 1 to 6 wt% of a viscosity modifier.

24. The hydraulic fluid composition of claim 23, wherein the viscosity modifier is selected from the group consisting of styrene-butadiene rubber, olefin copolymers, hydrogenated styrene-isoprene polymers, hydrogenated free radical isoprene polymers, poly(meth)acrylates, polyalkylstyrenes, hydrogenated alkenyl aryl conjugated diene copolymers, esters of maleic anhydride-styrene copolymers, or mixtures thereof.

25. A hydraulic fluid composition according to any preceding claim further comprising 0 wt% or 0.001 wt% to 0.1 wt%, 0.01 wt% to 0.04 wt% or 0.015 wt% to 0.03 wt% of a metal deactivator.

26. The hydraulic fluid of claim 25, wherein the metal deactivator comprises a derivative of benzotriazole, 1,2,4-triazole, benzimidazole, 2-alkyldithiobenzimidazole, 2-alkyldithiobenzothiazole or dimercaptothiadiazole, or a mixture thereof.

27. A hydraulic fluid according to any preceding claim further comprising up to 0.4 wt% or 0.005 wt% to 0.3 wt% of a pour point depressant.

28. The hydraulic fluid of claim 27, wherein the pour point depressant is selected from the group consisting of esters of maleic anhydride-styrene copolymers, polymethacrylates; polyacrylates; polyacrylamides; condensation products of halogenated paraffins and aromatic compounds; carboxylic acid vinyl ester polymers; terpolymers of dialkyl fumarates, vinyl esters of fatty acids, ethylene-vinyl acetate copolymers, alkylphenol formaldehyde condensation resins, alkyl vinyl ethers, and mixtures thereof.

29. A hydraulic fluid composition according to any preceding claim, wherein the hydraulic fluid composition contains less than 10 ppm or even less than 5 ppm zinc.

30. A hydraulic fluid composition according to any preceding claim, wherein the hydraulic fluid composition contains less than 500 ppm sulphur.

31. A hydraulic fluid composition according to any one of claims 1 to 28, wherein the hydraulic fluid composition is substantially free of ash.

32. A method of lubricating a hydraulic system, the method comprising supplying the hydraulic system with a hydraulic fluid composition according to any preceding claim.

33. A method of operating a hydraulic system, the method comprising supplying the hydraulic system with a hydraulic fluid composition according to any one of claims 1 to 31.

34. Use of a composition according to any one of claims 1 to 31 for lubricating a hydraulic system.

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