Industrial lubricant compositions having improved thermal stability

Abstract

The invention relates to industrial gear oil compositions that have been designed to have improved thermal stability. These improvements are particularly relevant hydrocarbon base oils, wherein the hydrocarbon base oil contains at least 50% mineral oil. The inclusion of a β-branched, primary, saturated alcohol having 12 or more carbon atoms to the industrial gear oil composition provides enhanced thermal stability.

Description

TITLEINDUSTRIAL LUBRICANT COMPOSITIONS HAVING IMPROVED THERMAL STABILITYBACKGROUND OF THE INVENTION

[0001] Industrial gearboxes often encounter extreme operating conditions that can lead to damage, for example, wear to the internal components of the gearbox. This damage reduces the life of the industrial gearbox and can lead to costly and prolonged maintenance, repair costs, as well as unscheduled downtime for the equipment that contains the industrial gearbox, among other issues. Thus, there is an ongoing need for improved industrial lubricants for the protection of gearboxes to aid in extending the service life of the gearbox and the equipment that contains the gearbox.

[0002] One of the extreme operating conditions that industrial gearboxes face is elevated temperature. There is an ongoing need from improved industrial lubricants that have increased thermal stability in order to better protect gearboxes for a longer period of time over a greater temperature range.SUMMARY OF THE INVENTION

[0003] The present invention provides industrial lubricant compositions, and in particular industrial gear oil lubricant compositions, having improved thermal stability. The invention provides an industrial lubricant composition comprising: (a) a hydrocarbon base oil comprising at least 50 wt% mineral oil; (b) a metal-free phosphorous containing anti -wear agent in an amount to deliver 300ppm to 500 ppm phosphorous to the lubricant composition; (c) a sulfurized olefin in an amount to deliver 4000 ppm to 8000 ppm sulfur to the lubricant composition; and (d) a P- branched, primary, saturated alcohol having 12 or more carbon atoms.

[0004] The invention also provides for the use of a P-branched, primary, saturated alcohol having 12 or more carbon atoms to improve the thermal stability of an industrial lubricant composition where the industrial lubricant composition comprises (a) a hydrocarbon base oil comprising at least 50 wt% mineral oil, (b)a metal-free phosphorous containing anti-wear agent in an amount to deliver 300 ppm to 500 ppm phosphorous to the lubricant composition, and (c) a sulfurized olefin in an amount to deliver 4000 ppm to 8000 ppm sulfur to the lubricant composition.DETAILED DESCRIPTION OF THE INVENTION

[0005] Various features and embodiments will be described below by way of nonlimiting illustration.

[0006] The industrial lubricant compositions of the present invention comprise: (a) a hydrocarbon base oil comprising at least 50 wt% mineral oil; (b) a metal-free phosphorous containing anti -wear agent in an amount to deliver 300ppm to 500 ppm phosphorous to the lubricant composition; (c) a sulfurized olefin in an amount to deliver 4000 ppm to 8000 ppm sulfur to the lubricant composition; and (d) a P- branched, primary, saturated alcohol having 12 or more carbon atoms. Optionally, the industrial lubricant composition contains other additives useful in industrial lubricants. Oil of Lubricating Viscosity

[0007] The compositions of the invention include an oil of lubricating viscosity, and more specifically, a hydrocarbon base oil. The oil of lubricating viscosity may include natural and synthetic oils, oil derived from hydrocracking, hydrogenation, and hydrofinishing, unrefined, refined and re-refined oils or mixtures thereof. Unrefined oils are those obtained directly from a natural or synthetic source generally without (or with little) further purification treatment. Refined oils are similar to the unrefined oils except they have been further treated in one or more purification steps to improve one or more properties. Purification techniques are known in the art and include solvent extraction, secondary distillation, acid or base extraction, filtration, percolation and similar processes. Re-refined oils are also known as reclaimed or reprocessed oils and are obtained by processes similar to those used to obtain refined oils. Re-refined oils are often processed by techniques directed to removal of spent additives and oil breakdown products. Natural oils useful as the oil of lubricating viscosity include animal oils and vegetable oils (e.g., castor oil, lard oil), mineral lubricating oils such as liquid petroleum oils and solvent-treated or acid-treated mineral lubricating oils of the paraffinic, naphthenic or mixed paraffinic naphthenic types and oils derived from coal or shale or mixtures thereof.

[0008] Oils of lubricating viscosity may be defined as specified in the American Petroleum Institute (API) Base Oil Interchangeability Guidelines. The five base oil groups are as follows: Group I (sulfur content >0.03 percent by weight, and / or <90 percent by weight saturates, viscosity index 80-120); Group II (sulfur content <0.03percent by weight and >90 percent by weight saturates, viscosity index 80-120); Group III (sulfur content <0.03 percent by weight and >90 percent by weight saturates, viscosity index >120); Group IV (all polyalphaolefins, or PAO, such as PAO-2, PAO-4, PAO-5, PAO-6, PAO-7 or PAO-8); and Group V (which encompasses “all others”).

[0009] In the present invention, the base oil may be selected from a Group I, Group II, or Group III base oil. In one embodiment, the base oil is selected from a Group I base oil, a Group II base oil, or mixtures thereof. In the present invention, the base oil of lubricating viscosity is a hydrocarbon base oil comprising at least 50 wt% mineral oil. In one embodiment, the oil of lubricating viscosity consists of mineral oil.

[0010] In a fully formulated lubricant, the oil of lubricating viscosity is generally present in a major amount (i.e., an amount greater than 50 percent by weight). For example, the oil of lubricating viscosity may be present in an amount of 60 to 98 percent by weight or even 75 to 98 percent by weight of the overall lubricant composition.

[0011] In one embodiment of the present invention, the hydrocarbon base oil has a kinematic viscosity at 100°C of 4 o 12 cSt as measured by ASTM D445. In another embodiment, the hydrocarbon base oil comprises a mixture of hydrocarbon base oils. For example, such a mixture may contain a first hydrocarbon base oil having a kinematic viscosity at 100°C of 4 cSt to 15 cSt or 4 cSt to 12 cSt (ASTM D445) and a second hydrocarbon base oil having a kinematic viscosity at 100°C of 20 to 35 cSt (ASTM D445). The second base oil may be present in the mixture in order to thicken the lubricating composition with or without the use of additional polymeric thickening additives. The second hydrocarbon base oil having a kinematic viscosity at 100°C of 20 to 35 cSt is commonly referred to as Brightstock. In one embodiment of the invention, the Brightstock may be present in an amount of up to 90 wt% or 55 wt% to 80 wt% of the lubricating composition, in some embodiments, the lubricating composition is free of Brightstock.

[0012] The various described oils of lubricating viscosity may be used alone or in combinations. The oil of lubricating viscosity (considering all oil present) may be used in the described industrial lubricant compositions in the range of about 40 or 50percent by weight to about 99 percent by weight, or from a minimum of 55, 60, 70, 75, 80, 90, 95 or even 97 up to a maximum of 99.8, 99, 98.5, 98 or even 97 percent by weight.

[0013] In concentrate compositions, 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 efficient to store and / or transport. A person skilled in the art would be able to easily adjust the amount of oil of lubricating viscosity present in order to provide a concentrate and / or additive composition.Phosphorous Containing Anti-Wear

[0014] The industrial lubricant composition of the present invention also includes a metal-free phosphorous containing anti-wear agent. Phosphorus containing antiwear and / or extreme pressure agents that are typically used in industrial gear lubricants are for the most part partially or fully esterified acids of phosphorus. Such antiwear agents include, but are not limited to, acid phosphates, hydrogen phosphites, phosphites, phosphates, phosphonates, phosphinates, and phosphoroamidates. Further antiwear agents can also include mono, di and trihydrocarbyl phosphites; mono, di, and trihydrocarbyl phosphates; mono, di, and trihydrocarbyl mono, di, tri, tetrathiophosphates; mono, di, trihydrocarbyl mono, di, tri, tetrathiophosphites; various hydrocarbyl phosphonates and thiophosphonates; dialkyl dithiophosphate esters and derivatives thereof, and various hydrocarbyl phosphonites and thiophosphonites, and the like.

[0015] Examples of phosphites include mono-hydrocarbyl substituted phosphite, a di-hydrocarbyl substituted phosphite, or a tri-hydrocarbyl substituted phosphite, and those phosphites having at least one hydrocarbyl group with 4 or more carbon atoms as represented by the formulae:wherein at least one of R8, R6and R7may be a hydrocarbyl group containing at least 4 carbon atoms and the other may be hydrogen or a hydrocarbyl group. In one embodiment R8, R6and R7are all hydrocarbyl groups. The hydrocarbyl groups may be alkyl, cycloalkyl, aryl, acyclic or mixtures thereof. In the formula with all three groups R8, R6and R7, the compound may be a tri-hydrocarbyl substituted phosphite i.e., R8, R6and R7are all hydrocarbyl groups. Alkyl groups may be linear or branched, typically linear, and saturated or unsaturated, typically saturated. Examples of alkyl groups for R8, R6and R7include octyl, 2-ethylhexyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, octadecenyl, nonadecyl, eicosyl or mixtures thereof.

[0016] All of the amine salts that can be formed with the above-mentioned phosphorus containing antiwear agents are included. The amines can be primary, secondary, tertiary, acyclic or cyclic, mono or polyamines. They can also be heterocyclic. The preferred amines are generally aliphatic in nature. Some specific examples of amines for producing amine salts of the phosphorus containing antiwear agents include: octylamine, decylamine, CIO, C12, C14 and C16 tertiary alkyl primary amines (or combinations thereof), laurylamine, hexadecylamine, heptadecylamine, octadecylamine, decenylamine, dodecenylamine, palmitoylamine, oleylamine, linoleylamine, di-isoamylamine, di-octylamine, di-(2-ethylhexyl)amine, dilauryl amine, cyclohexylamine, 1,2-propylene amine, 1,3 -propylenediamine, diethylene triamine, triethylene tetraamine, ethanolamine, triethanolamine, trioctylamine, pyridine, morpholine, 2-methylpiperazine, l,2-bis(N-piperazinyl- ethane), 1,2-diamine, tetraminooctadecene, triaminooctadecene, N-hexylaniline and the like. The amines may also be triazole or triazole derivatives.

[0017] In an embodiment, an amine salt of the phosphorus containing antiwear agent are those of the formula:where R9and R10are independently aliphatic groups containing from about 4 up to about 24 carbon atoms, R22and R23are independently hydrogen or aliphatic groupscontaining from about 1 up to about 18 aliphatic carbon atoms, the sum of m and n is 3 and X is oxygen or sulfur. In a preferred embodiment, R9contains from about 8 up to 18 carbon atoms, R10is:wherein R11is an aliphatic group containing from about 6 up to about 12 carbon atoms, R22and R23are hydrogen, m is 2, n is 1 and X is oxygen.

[0018] Specific examples of phosphorus containing antiwear agents can include tricresyl phosphate, tributylphosphite, triphenyl phosphite, 2-ethylhexyl phosphate, diisobutylhydrogen phosphite, diisopropyl dithiophosphate, diphenyl phosphate, fatty phosphites, etc. Some embodiments of phosphorus containing antiwear agents can include the dialkyl and diaryl phosphates and their amine salts. Also considered are aryl phosphates, such as the commercially available Irgalube™ 349 from Ciba and alkyl acid phosphates, including di- and / or mono-2-ethylhexyl phosphoric acid.

[0019] Phosphorous containing anti-wear agents are employed in amounts sufficient to deliver 150 ppm to 500 ppm or 180 ppm to 400 ppm or 200 ppm to 350ppm phosphorous to the lubricant composition.Sulfurized Olefin

[0020] The industrial lubricant composition of the present invention also includes a sulfurized olefin. Sulfurized olefins are well known commercial materials prepared by reacting a single reactant or a mixture of appropriate reactants with a source of sulfur. The sulfurization reaction generally is conducted at an elevated temperature, e.g., 50-350°C or 100-200°C, with efficient agitation and often in an inert atmosphere such as nitrogen, optionally in the presence of an inert solvent. The sulfurizing agents can include elemental sulfur, which is preferred, hydrogen sulfide, sulfur halide, sodium sulfide and a mixture of hydrogen sulfide and sulfur or sulfur dioxide. Usually, the amount of sulfur or sulfurizing agent employed is calculated based on the total olefinic unsaturation of the mixture. Typically, 0.5 to 3 moles of sulfur are employed per mole of olefinic bonds. One type of sulfurized olefin can be prepared in accordance with the detailed teachings of U.S. Pat. No. 4,957,651.

[0021] In the case of sulfurized olefins, the reactant can be an olefinic compound. Olefinic compounds which may be sulfurized are diverse in nature, and broadly speaking are those that contain at least one olefinic double bond, which is defined as a non-aromatic double bond; that is, a double bond connecting two aliphatic carbon atoms. In its broadest sense, the olefin may be defined by the formula R1R2C=CR3R4, wherein each of R1, R2, R3and R4can be hydrogen or an organic group. In general, the R groups in the above formula which are not hydrogen may be satisfied by such groups as -C(R5)3, -COOR5, -C00M, -X, -YR5or -Ar, wherein each R5is independently hydrogen, alkyl, alkenyl, aryl, substituted alkyl, substituted alkenyl or substituted aryl, with the proviso that any two R5groups can be alkylene or substituted alkylene whereby a ring of up to 12 carbon atoms is formed; M is one equivalent of a metal cation (preferably Group I or II, e.g., sodium, potassium, barium, calcium); X is halogen (e.g., chloro, bromo, or iodo); Y is oxygen or divalent sulfur; Ar is an aryl or substituted aryl group of up to 12 carbon atoms. Any two of R1, R2, R3and R4may also together form an alkylene or substituted alkylene group, i.e., the olefinic compound may be alicyclic.

[0022] The olefinic compound is usually one in which each R group, above, which is not hydrogen is independently alkyl, alkenyl or aryl group. Monoolefinic and diolefinic compounds, particularly the former, are preferred, and especially terminal monoolefinic hydrocarbons; that is, those compounds in which R3and R4are hydrogen and R1and R2are alkyl or aryl, especially alkyl (that is, the olefin is aliphatic) having 1 to 30, or 1 to 16, or 1 to 8, or 1 to 4 carbon atoms. Olefinic compounds having 3 to 30 or 3 to 16 (often fewer than 9) carbon atoms can be used.

[0023] Isobutylene, di-isobutylene, butylene, propylene and their dimers, trimers and tetramers, and mixtures thereof are useful as olefinic compounds for sulfurization, as are terpene compounds, that is, various isomeric terpene hydrocarbons having the empirical formula CioHie, as well as various synthetic and naturally occurring oxygen-containing derivatives thereof.

[0024] Other sulfurized olefins include those derived from natural sources, such as sulfurized vegetable oils and sulfurized lard oil (that is, sulfurized oils of animal sources generally). Example of natural oils from which such sulfurized olefins may be derived can include, but not be limited to, coconut oil, corn oil, cottonseed oil,castor oil, sunflower oil, olive oil, palm oil, peanut oil, rapeseed oil, safflower oil, sesame oil, soybean oil, tallow, lard, fatty acids, and mixtures thereof. Preferred organic portions for the sulfurized vegetable oil are those derived from sunflower oil, olive oil, and rapeseed oil.

[0025] In one embodiment, the sulfur component of the additive package of the present technology may comprise a biodegradable sulfurized olefin derived from a natural source such as sulfurized vegetable oil or sulfurized lard.

[0026] The total level of sulfur in the sulfurized olefin can be measured according to ASTM D129Q. Whether biodegradable or non-biodegradable, the sulfurized olefins can have a “high,” “nominal,” or “minimal,” level of total sulfur. A “high” level of sulfur means the sulfurized olefin contains about 30 wt% or greater sulfur. A “nominal” level of sulfur means the sulfurized olefin contains from about 10 to about 30 wt% sulfur, and a “minimal” level of sulfur means the sulfurized olefin contains less than about 10 wt% sulfur, or from about 0.01 to about 10 wt% sulfur.

[0027] In the present invention, it has been found that the amount of sulfurized olefin in the lubricating composition can be reduced with the addition of a small amount of ZDDP, which is a known anti-wear agent, while maintaining extreme pressure performance.

[0028] In the present invention, the sulfurized olefin can be included in the fully formulated lubricant at a level of about 0.1% by weight to about 3% by weight, or from about 0.2% by weight to about 2% by weight, or even from about 0.4% by weight to about 1.5% by weight. In some embodiments, the sulfurized olefin can be employed in an amount sufficient to deliver a total sulfur level in the fully formulated lubricant of 4000 ppm to 8000 ppm or 5000 ppm to 7000ppm or 5000 ppm to 6000 ppm.P-Branched Alcohol

[0029] The compositions of the invention include a P-branched, primary, saturated alcohol having 12 or more carbon atoms.

[0030] P-branched, primary, saturated alcohols suitable for use in the lubricating composition may contain 12 to 50 carbon atoms, for example, 12 to 32, or 12 to 30, or 12 to 26, or 14 to 16, or at least 12 carbons, at least 14 carbons, and in someembodiments, up to 32 carbons, up to 30 carbons, up to 24 carbons, up to 22 carbons, or up to 18 carbons. Mixtures of alcohols may also be used.

[0031] In one embodiment, the alcohol comprises a P-branched alcohol having the structure of Formula I:where R1is CH3 or an alkyl chain having 6 to 20 or 8 to 16 or 8 to 10 carbon atoms and R2is an alkyl chain having 4 to 14 or 6 to 12 or 10 to 12 carbon atoms.

[0032] In some embodiments, the P-branched alcohol includes one or more Guerbet alcohols. Guerbet alcohols may be described as alcohols made via the Guerbet reaction, which was named after Marcel Guerbet. In a Guerbet reaction, a primary aliphatic alcohol is converted to its P-alkylated dimer alcohol (i.e., a branched, primary, saturated alcohol). Examples of alcohols of Formula I include 2- ethylhexanol, 2-butyloctanol, 2-hexyldecanol, 2-octyldodecanol, 2- decyltetradecanol, 2-dodecylhexadecanol, or any combination thereof. These types of alcohols are commercially available from Sasol and marketed as ISOFOL® alcohols. In some embodiments, the alcohol includes 2-hexyldecanol, 2- decyltetradecanol, or any combination thereof. In some embodiments, the alcohol includes 2-hexyldecanol. In some embodiments, the alcohol includes 2- decyltetradecanol. In some embodiments, the lubricating composition is substantially free of or free of 2-ethylhexanol and / or 2-butyloctanol.

[0033] Examples of alcohols which may be used in the present invention are summarized in the table below, where the alcohols have the formula of Formula I:

[0034] The P-branched alcohol may be present in the industrial lubricant composition at in amounts of 1 wt% to 20 wt%, or 2 wt% to 15 wt% or 5 wt% to 10 wt%.Other Additives

[0035] The lubricant compositions of the invention may also include other additives useful in industrial lubricant compositions. Such additives may include, but are not limited to, a foam inhibitor, a demulsifier, a pour point depressant, an antioxidant, a dispersant, a metal deactivator (such as a copper deactivator), an extreme pressure agent, a viscosity modifier, or some mixture thereof. The additives may each be present in the range from 50, 75, 100 or even 150 ppm up to 5, 4, 3, 2 or even 2.5 percent by weight, or from 75 ppm to 0.5 percent by weight, from 100 ppm to 0.4 percent by weight, or from 150 ppm to 0.3 percent by weight, where the percent by weight values are with regards to the overall lubricant composition. In other embodiments, the overall industrial additive package is present from 1 to 20, or from 1 to 10 percent by weight of the overall lubricant composition. However, it is noted that some additives, including viscosity modifying polymers, which may alternatively be considered as part of the base fluid, may be present in higher amounts including up to 30, 40, or even 50% by weight when considered separate from the base fluid. The additives may be used alone or as mixtures thereof.

[0036] The compositions of the invention may also include antifoams, also known as foam inhibitors, which include but are not limited to organic silicones and nonsilicon foam inhibitors. Examples of organic silicones include dimethyl silicone and polysiloxanes. Examples of non-silicon foam inhibitors include but are not limited to polyethers, polyacrylates and mixtures thereof as well as copolymers of ethyl acrylate, 2-ethylhexylacrylate, and optionally vinyl acetate. In some embodiments,the antifoam is a polyacrylate. Antifoams may be present in the composition from 0.001 to 0.012 or 0.004 pbw or even 0.001 to 0.003 pbw.

[0037] The compositions of the invention may also include demulsifiers, which include but are not limited to derivatives of propylene oxide, ethylene oxide, polyoxyalkylene alcohols, alkyl amines, amino alcohols, diamines or polyamines reacted sequentially with ethylene oxide or substituted ethylene oxides or mixtures thereof. Examples of demulsifiers include polyethylene glycols, polyethylene oxides, polypropylene oxides, (ethylene oxide-propylene oxide) polymers and mixtures thereof. In some embodiments, the demulsifiers are polyethers. Demulsifiers may be present in the composition from 0.002 to 0. 2 pbw.

[0038] The compositions of the invention may also include pour point depressants, which include but are not limited to esters of maleic anhydride-styrene copolymers, polymethacrylates; polyacrylates; polyacrylamides; condensation products of haloparaffin waxes and aromatic compounds; vinyl carboxylate polymers; and terpolymers of dialkyl fumarates, vinyl esters of fatty acids, ethylenevinyl acetate copolymers, alkyl phenol formaldehyde condensation resins, alkyl vinyl ethers and mixtures thereof.

[0039] The compositions of the invention may also include a rust inhibitor, other than some of the additives described above. Suitable rust inhibitors include hydrocarbyl amine salts of dialkyldithiophosphoric acid, hydrocarbyl amine salts of hydrocarbyl arenesulphonic acid, fatty carboxylic acids or esters thereof, an ester of a nitrogen-containing carboxylic acid, an ammonium sulfonate, an imidazoline, mono-thio phosphate salts or esters, or any combination thereof, or mixtures thereof. Examples of hydrocarbyl amine salts of dialkyldithiophosphoric acid of the invention include but are not limited to those described above, as well as the reaction product(s) of diheptyl or dioctyl or dinonyl dithiophosphoric acids with ethylenediamine, morpholine or Primene™ 81R or mixtures thereof. Suitable hydrocarbyl amine salts of hydrocarbyl arenesulphonic acids used in the rust inhibitor package of the invention are represented by the formula:wherein Cy is a benzene or naphthalene ring. R1is a hydrocarbyl group with about 4 to about 30, preferably about 6 to about 25, more preferably about 8 to about 20 carbon atoms, z is independently 1, 2, 3, or 4 and most preferably z is 1 or 2. R2, R3and R4are the same as described above. Examples of hydrocarbyl amine salts of hydrocarbyl arenesulphonic acid of the invention include but are not limited to the ethylenediamine salt of dinonylnaphthalene sulfonic acid. Examples of suitable fatty carboxylic acids or esters thereof include glycerol monooleate and oleic acid. An example of a suitable ester of a nitrogen-containing carboxylic acid includes oleyl sarcosine. The rust inhibitors may be present in the range from 0.02 to 0.2, from 0.03 to 0.15, from 0.04 to 0.12, or from 0.05 to 0.1 percent by weight of the lubricating oil composition. The rust inhibitors of the invention may be used alone or in mixtures thereof.

[0040] The compositions of the invention may also include a metal deactivator. Metal deactivators are used to neutralise the catalytic effect of metal for promoting oxidation in lubricating oil. Suitable metal deactivators include but are not limited to triazoles, tolyltriazoles, a thiadiazole, or combinations thereof, as well as derivatives thereof. Examples include derivatives of benzotriazoles other than those described above, benzimidazole, 2-alkyldithiobenzimidazoles, 2- alkyldithiobenzothiazoles, 2-(N,N’-dialkyldithio-carbamoyl)benzothiazoles, 2,5- bis(alkyl-dithio)-l,3,4-thiadiazoles, 2, 5-bis(N,N’ -dialkyldithiocarbamoyl)- 1,3,4- thiadiazoles, 2-alkyldithio-5-mercapto thiadiazoles or mixtures thereof. These additives may be used from 0.01 to 0.25 percent by weight in the overall composition. In some embodiments, the metal deactivator is a hydrocarbyl substituted benzotriazole compound. The benzotriazole compounds with hydrocarbyl substitutions include at least one of the following ring positions 1- or 2- or 4- or 5- or 6- or 7- benzotriazoles. The hydrocarbyl groups contain about 1 to about 30,preferably about 1 to about 15, more preferably about 1 to about 7 carbon atoms, and most preferably the metal deactivator is 5-methylbenzotriazole used alone or mixtures thereof. The metal deactivators may be present in the range from 0.001 to 0.5, from 0.01 to 0.04 or from 0.015 to 0.03 pbw of the lubricating oil composition. Metal deactivators may also be present in the composition from 0.002 or 0.004 to 0.02 pbw. The metal deactivator may be used alone or mixtures thereof.

[0041] The compositions of the invention may also include antioxidants, including (i) an alkylated diphenylamine, and (ii) a substituted hydrocarbyl monosulfide. In some embodiments, the alkylated diphenylamines of the invention are bis- nonylated diphenylamine and bis-octylated diphenylamine. In some embodiments, the substituted hydrocarbyl monosulfides include n-dodecyl-2-hydroxyethyl sulfide, l-(tert-dodecylthio)-2-propanol, or combinations thereof. In some embodiments, the substituted hydrocarbyl monosulfide is l-(tert-dodecylthio)-2-propanol. The antioxidant package may also include sterically hindered phenols. Examples of suitable hydrocarbyl groups for the sterically hindered phenols include but are not limited to 2-ethylhexyl or n-butyl ester, dodecyl or mixtures thereof. Examples of methylene-bridged sterically hindered phenols include but are not limited to 4,4 - methylene-bis(6-tert-butyl o-cresol), 4,4'-methylene-bis(2-tert-amyl-o-cresol), 2,2 - methylene-bis(4-methyl-6-tert-butylphenol), 4,4'-methylene-bis(2,6-di- tertbutylphenol) or mixtures thereof.

[0042] The compositions of the invention may also include nitrogen-containing dispersants, for example, a hydrocarbyl substituted nitrogen containing additive. Suitable hydrocarbyl substituted nitrogen containing additives include ashless dispersants and polymeric dispersants. Ashless dispersants are so-named because, as supplied, they do not contain metal and thus do not normally contribute to sulfated ash when added to a lubricant. However, they may, of course, interact with ambient metals once they are added to a lubricant which includes metal-containing species. Ashless dispersants are characterized by a polar group attached to a relatively high molecular weight hydrocarbon chain. Examples of such materials include succinimide dispersants, Mannich dispersants, and borated derivatives thereof.

[0043] The compositions of the invention may also include one or more addititional anti -wear additives and / or extreme pressure agents, one or more rustand / or corrosion inhibitors, one or more foam inhibitors, one or more demulsifiers, or any combination thereof.

[0044] In some embodiments, the industrial lubricant additive packages, or the resulting industrial lubricant compositions, include a demulsifier, a corrosion inhibitor, a friction modifier, or combination of two or more thereof. In some embodiments, the corrosion inhibitor includes a tolyltriazole. In still other embodiments, the industrial additive packages, or the resulting industrial lubricant compositions, include one or more sulfurized olefins or polysulfides; one or more phosphorus amine salts; one or more thiophosphate esters, one or more thiadiazoles, tolyltriazoles, polyethers, and / or alkenyl amines; one or more ester copolymers; one or more carboxylic esters; one or more succinimide dispersants, or any combination thereof.

[0045] The industrial lubricant additive package may be present in the overall industrial lubricant from 1 to 5 percent by weight, or in other embodiments from 1, 1.5, or even 2 percent by weight up to 2.5, 3, 4, 5, 7 or even 10 percent by weight. Amounts of the industrial gear additive package that may be present in the industrial gear concentrate compositions of the invention are the corresponding amounts to the weight percent above, where the values are considered without the oil present (i.e., they may be treated as pbw values along with the actual amount of oil present). Industrial Application

[0046] As noted above, the invention includes both industrial lubricant compositions and industrial additive concentrate compositions that may be used to make industrial lubricant compositions. In some embodiments, the industrial lubricant compositions of the invention are industrial gear lubricant compositions.

[0047] The various ranges for the components described above can be applied to concentrate compositions by maintaining the same relative ratios between components (b) and (c), while adjustment the amount of (a), (that is the amount of(a) will be much lower in a concentrate composition compared to a lubricant composition). In such embodiments, the percent by weight values for components(b) and (c) may be treated as parts by weight (pbw), with oil making up the balance of the concentrate composition, including anywhere from 0 or 0.1 or 0.5 or even 1 pbw up to 10, 20, 30 or even 40 or 50 pbw oil and / or base fluid.

[0048] The invention provides a method of improving the overall thermal stability of an industrial lubricant composition comprising adding a P-branched, primary, saturated alcohol having 12 or more carbon atoms to a lubricant composition comprising (a) a hydrocarbon base oil comprising at least 50 wt% mineral oil; (b) a metal-free phosphorous containing anti -wear agent in an amount to deliver 150ppm to 500 ppm or 180 ppm to 400 ppm or 200 ppm to 300 ppm phosphorous to the lubricant composition; and (c) a sulfurized olefin in an amount to deliver 4000 ppm to 8000 ppm or 5000 ppm to 7000 ppm or 5000 ppm to 6000 ppm sulfur to the lubricant composition.

[0049] The invention also provides for the use of a P-branched, primary, saturated alcohol having 12 or more carbon atoms to improve the thermal stability of a lubricant composition comprising (a) a hydrocarbon base oil comprising at least 50 wt% mineral oil; (b) a metal-free phosphorous containing anti-wear agent in an amount to deliver 150 ppm to 500 ppm or 180 ppm to 400 ppm or 200 ppm to 300 ppm phosphorous to the lubricant composition; and (c) a sulfurized olefin in an amount to deliver 4000 ppm to 8000 ppm or 5000 ppm to 7000 ppm or 5000 ppm to 6000 ppm sulfur to the lubricant composition.

[0050] The industrial lubricant composition provided by the invention herein may have a kinematic viscosity at 40°C (ISO viscosity grade) of 100 cSt to 680 cSt or 150 cSt to 680 cSt or 200 cSt to 480 cSt (ASTM D445).

[0051] The amount of each chemical component described is presented exclusive of any solvent or diluent oil, which may be customarily present in the commercial material, that is, on an active chemical basis, unless otherwise indicated. However, unless otherwise indicated, each chemical or composition referred to herein should be interpreted as being a commercial grade material which may contain the isomers, byproducts, derivatives, and other such materials which are normally understood to be present in the commercial grade.

[0052] As used herein, the term "hydrocarbyl substituent" or "hydrocarbyl group" is used in its ordinary sense, which is well-known to those skilled in the art. Specifically, it refers to a group having a carbon atom directly attached to the remainder of the molecule and having predominantly hydrocarbon character. Examples of hydrocarbyl groups include: (i) hydrocarbon substituents, that is, aliphatic (e.g., alkyl or alkenyl), alicyclic (e.g., cycloalkyl, cycloalkenyl) substituents, and aromatic-,aliphatic-, and alicyclic-substituted aromatic substituents, as well as cyclic substituents wherein the ring is completed through another portion of the molecule (e.g., two substituents together form a ring); (ii) substituted hydrocarbon substituents, that is, substituents containing non-hydrocarb on groups which, in the context of this invention, do not alter the predominantly hydrocarbon nature of the substituent (e.g., halo (especially chloro and fluoro), hydroxy, alkoxy, mercapto, alkylmercapto, nitro, nitroso, and sulfoxy); (iii) hetero substituents, that is, substituents which, while having a predominantly hydrocarbon character, in the context of this invention, contain other than carbon in a ring or chain otherwise composed of carbon atoms and encompass substituents as pyridyl, furyl, thienyl and imidazolyl. Heteroatoms include sulfur, oxygen, and nitrogen. In general, no more than two, or no more than one, nonhydrocarbon substituent will be present for every ten carbon atoms in the hydrocarbyl group; alternatively, there may be no non-hydrocarbon substituents in the hydrocarbyl group.

[0053] It is known some of the materials described above may interact in the final formulation, so that components of the final formulation may be different from those initially added. For instance, metal ions (of, e.g., a detergent) can migrate to other acidic or anionic sites of other molecules. The products formed thereby, including the products formed upon employing the composition of the invention in its intended use, may not be susceptible of easy description. Nevertheless, all such modifications and reaction products are included within the scope of the invention; the invention encompasses the composition prepared by admixing the components described above.

[0054] The invention may be better understood with reference to the following nonlimiting examples.EXAMPLES

[0055] A series of industrial gear lubricating compositions were prepared in Group I and Group II mineral oils. In addition to oils of lubricating viscosity, the lubricating compositions contained metal free phosphorus anti-wear agents, sulfurized olefins, and other additives including corrosion inhibitors, metal passivators, foam inhibitors, demulsifiers, and pourpoint depressants. Compositions were divided into two broad groups, based upon blending strategy to achieve desired viscosity. In the first group, lubricating compositions were thickened by employing mineral oil “bright stock”(kinematic viscosity of approximately 30 cSt at 100 °C) as both the oil of lubricating viscosity and the thickening agent (Table 1). The second group of lubricating compositions were blended in lower viscosity mineral oil and employed polymeric thickeners (e.g. polyisobutylene, i.e. PIB; or ethylene-propylene, i.e. EP, copolymer) to achieve desired viscosity levels (Table 2).

[0056] Beta-branched hydrocarbyl alcohols were included at various treat rates to assess the effect of the composition on oxidative stability.Table 1 - Industrial Gear Lubricating Compositions with Bright Stock11. All treat rates are oil free unless otherwise noted2. 2-octyl-l -dodecanol, available as Isofol 20 from Sasol3. Oleyl phosphite4. Salt of 2-ethylhexylamine and iso-octylphosphoric acid5. Other additives include corrosion inhibitor, metal passivator, pourpoint depressant, friction modifier, foam inhibitor, and demulsifier6. Kinematic viscosity at 40 O, determined according to ASTM D4457. Kinematic viscosity at 100 O, determined according to ASTM D445Table 2 - Industrial Gear Lubricating Compositions with Polymeric Thickeners11. All treat rates are oil free unless otherwise noted2. 2-octyl-l -dodecanol, available as Isofol 20 from Sasol3. Oleyl phosphite4. Salt of 2-ethylhexylamine and iso-octylphosphoric acid5. Poly isobutylene (Mn 2010; contains 10 wt% oil)6. Ethylene-propylene random copolymer (MW 11, 000; 60 wt% propylene) ; available as Lucant® HC- 11007. Other additives include corrosion inhibitor, metal passivator, pourpoint depressant, friction modifier, foam inhibitor, and demulsifier8. Kinematic viscosity at 40 O, determined according to ASTM D4459. Kinematic viscosity at 100 O, determined according to ASTM D44510. 2-hexyl-l-decanol, available as Isofol 16 from Saso

[0057] Lubricating compositions were evaluated for resistance to oxidation and resistance to corrosion resulting from oxidation. Determination of oxidation resistance was achieved with the SKF Roller Oxidation Test. Per the test procedure, 15 rollers (SKF Loose Roller RC-17xl7CD) are cleaned with tetrachloroethane and submerged in the lubricating composition to de evaluated. The immersed rollers are stored for 8 weeks in an oven at 120 °C, with samples rated every 2 weeks until end of test. Visual rating of the rollers (from 1 to 4) is determined; ratings are explained in Table 3 below. Table 3 - Evaluation of Rollersbranched alcohol in various base oil mixtures with increasing levels of the alcohol (Table 4).Table 4 - Roller Oxidation Evaluation*No beta-branched alcohol

[0059] In several of the examples, high viscosity mineral oil was replaced with lower viscosity mineral oils in conjunction with polymeric thickeners. The impact of polymeric thickeners and beta-branched alcohols in a series of lubricating compositions was evaluated for oxidative tarnishing (Table 5).Table 5 - Evaluation of Polymeric Thickeners and P-Branched Alcohols*No beta-branched alcohol

[0060] Each of the documents referred to above is incorporated herein by reference, including any prior applications, whether specifically listed above, from which priority is claimed. The mention of any document is not an admission that such document qualifies as prior art or constitutes the general knowledge of the skilled person in any jurisdiction. Except in the Examples, or where otherwise explicitly indicated, all numerical quantities in this description specifying amounts of materials, reaction conditions, molecular weights, number of carbon atoms, and the like, are to be understood as modified by the word "about." It is to be understood that the upper and lower amount, range, and ratio limits set forth herein may be independently combined. Similarly, the ranges and amounts for each element of the invention can be used together with ranges or amounts for any of the other elements.

[0061] As used herein, the transitional term “comprising,” which is synonymous with “including,” “containing,” or “characterized by,” is inclusive or open-ended and does not exclude additional, un-recited elements or method steps. However, in each recitation of “comprising” herein, it is intended that the term also encompass, as alternative embodiments, the phrases “consisting essentially of’ and “consisting of,” where “consisting of’ excludes any element or step not specified and “consisting essentially of’ permits the inclusion of additional un-recited elements or steps that donot materially affect the basic and novel characteristics of the composition or method under consideration.

[0062] While certain representative embodiments and details have been shown for the purpose of illustrating the subject invention, it will be apparent to those skilled in this art that various changes and modifications can be made therein without departing from the scope of the subject invention. In this regard, the scope of the invention is to be limited only by the following claims.

Claims

What is claimed is:

1. An industrial lubricant composition comprising:(a) a hydrocarbon base oil comprising at least 50 wt% mineral oil;(b) a metal-free phosphorous containing anti-wear agent in an amount to deliver 150 ppm to 500 ppm phosphorous to the lubricant composition;(c) a sulfurized olefin in an amount to deliver 4000 ppm to 8000 ppm or 5000 to 7000 ppm or 5000 to 6000 ppm sulfur to the lubricant composition; and(d) a P- branched, primary, saturated alcohol having 12 or more carbon atoms.

2. The industrial lubricant composition of claim 1, wherein the P-branched alcohol contains 10 to 32 carbon atoms, or 10 to 30 carbon atoms, or 12 to 26 carbon atoms, or 14 to 16 carbon atoms.

3. The industrial lubricant composition of claim 1, wherein the P-branched alcohol has the structure of Formula I:wherein R1is CH3 or an alkyl chain having 4 to 20 or 4 to 14 or 4 to 10, or 6 to 8 carbon atoms and R2is H or an alkyl chain having 4 to 16, or 6 to 16, or 6 to 12, or 8 to 10 carbon atoms.

4. The industrial lubricant composition of any of claims 1 to 3 wherein the lubricant composition contains 1 wt% to 20 wt% or 2 wt% to 15 wt% or 5 wt% to 10 wt% of the P-branched alcohol.

5. The industrial lubricant composition of any of claims 1 to 4, wherein the hydrocarbon base oil comprises or consists of a Group I base oil, a Group II base oil, or a mixture thereof.

6. The industrial lubricant composition of any of claims 1 to 5, wherein the hydrocarbon base oil consists of a Group I base oil.

7. The industrial lubricant composition of any of claims 1 to 5, wherein the hydrocarbon base oil consists of a Group II base oil.

8. The industrial lubricant composition of any of claims 1 to 7, wherein the hydrocarbon base oil has a kinematic viscosity at 100°C of 4 cSt to 15 cSt or 4 cSt to 12 cSt (ASTM D445).

9. The industrial lubricant composition of claim 8, further comprising a polymeric thickening additive.

10. The industrial lubricant composition of claim 9, wherein the polymeric thickening additive comprises or consists of a polyolefin thickener11. The industrial lubricant of claim 10, wherein the polyolefin thickener comprises an ethylene-propylene copolymer or a polyisobutylene.

12. The industrial lubricant composition of any of claims 9 to 11, wherein the polymeric thickening additive is present in an amount of 12 wt% to 45 wt% of the industrial lubricant composition.

13. The industrial lubricant composition of any of claims 1 to 7, wherein the hydrocarbon oil comprises a mixture of a first hydrocarbon base oil having a kinematic viscosity at 100°C of 4 cSt to 15 cSt or 4 cSt to 12 cSt and a second hydrocarbon base oil having a kinematic viscosity at 100°C of 20 to 35 cSt.

14. The industrial lubricant composition of claim 13, wherein the second base oil is present in an amount of up to 90wt% or 55 wt% to 80 wt% of the industrial lubricant composition.

15. The industrial lubricant composition of any of claims 1 to 14, wherein the industrial lubricant composition has a kinematic viscosity at 40°C of 100 cSt to 680 cSt or 150 cSt to 680 cSt or 200 cSt to 480 cSt (ASTM D445).

16. The industrial lubricant composition of any of claims 1 to 15, wherein the metal - free phosphorous containing antiwear agent is selected from phosphites, phosphonates, alkylphosphate esters, amine phosphate salts, ammonium phosphate salts, and mixtures thereof.

17. The industrial lubricant composition of any of claims 1 to 16, wherein the composition is an industrial gear oil lubricant composition or a hydraulic lubricant composition.

18. The industrial lubricant composition of any of claims 1 to 17, wherein the hydrocarbon base oil is present in an amount of 60 wt% to 98 wt% of the lubricant composition.

19. The industrial lubricant composition of any of claims 1 to 18, wherein the P- branched, primary, saturated alcohol having 12 or more carbon atoms is present in an amount of 1 wt% to 20 wt% of the lubricant composition.

20. A method of lubricating an industrial gearbox comprising delivering to the gearbox the industrial lubricant composition of any of claims 1 to 19.

21. The use of a P- branched, primary, saturated alcohol having 12 or more carbon atoms to improve the thermal stability of an industrial lubricant composition where the industrial lubricant composition comprises (a) a hydrocarbon base oil comprising at least 50 wt% mineral oil, (b)a metal-free phosphorous containing anti-wear agent in an amount to deliver 300 ppm to 500 ppm phosphorous to the lubricant composition, and (c) a sulfurized olefin in an amount to deliver 4000 ppm to 8000 ppm sulfur to the lubricant composition.

22. The use of a P- branched, primary, saturated alcohol having 12 or more carbon atoms to improve the thermal stability of an industrial lubricant composition as recited in claim 21, wherein the P-branched alcohol contains 10 to 32 carbon atoms, or 10 to 30 carbon atoms, or 12 to 26 carbon atoms, or 14 to 16 carbon atoms.

23. The use of a P- branched, primary, saturated alcohol having 12 or more carbon atoms to improve the thermal stability of an industrial lubricant composition as recited in claim 21 or 22, wherein the P-branched alcohol has the structure of Formula I:wherein R1is CH3 or an alkyl chain having 4 to 20 or 4 to 14 or 4 to 10, or 6 to 8 carbon atoms and R2is H or an alkyl chain having 4 to 16, or 6 to 16, or 6 to 12, or 8 to 10 carbon atoms.

24. The use of a P- branched, primary, saturated alcohol having 12 or more carbon atoms to improve the thermal stability of an industrial lubricant composition as recited in any of claims 21 to 23 wherein the lubricant composition contains 1 wt% to 20 wt% or 2 wt% to 15 wt% or 5 wt% to 10 wt% of the P-branched alcohol.

25. The use of a P- branched, primary, saturated alcohol having 12 or more carbon atoms to improve the thermal stability of an industrial lubricant composition as recited in any of claims 21 to 44, wherein the hydrocarbon base oil comprises or consists of a Group I base oil, a Group II base oil, or a mixture thereof.

26. The use of a P- branched, primary, saturated alcohol having 12 or more carbon atoms to improve the thermal stability of an industrial lubricant composition as recited in any of claims 21 to 25, wherein the hydrocarbon base oil consists of a Group I base oil.

27. The use of a P- branched, primary, saturated alcohol having 12 or more carbon atoms to improve the thermal stability of an industrial lubricant composition as recited in any of claims 21 to 25, wherein the hydrocarbon base oil consists of a Group II base oil.

28. The use of a P- branched, primary, saturated alcohol having 12 or more carbon atoms to improve the thermal stability of an industrial lubricant composition as recited in any of claims 21 to 27, wherein the hydrocarbon base oil has a kinematic viscosity at 100°C of 4 cSt to 15 cSt or 4 cSt to 12 cSt (ASTM D445).

29. The use of a P- branched, primary, saturated alcohol having 12 or more carbon atoms to improve the thermal stability of an industrial lubricant composition as recited in any of claims 21 to 27, wherein the lubricant composition further comprises a polymeric thickening additive.

30. The use of a P- branched, primary, saturated alcohol having 12 or more carbon atoms to improve the thermal stability of an industrial lubricant composition as recited in claim 29, wherein the polymeric thickening additive comprises or consists of a polyolefin thickener31. The use of a P- branched, primary, saturated alcohol having 12 or more carbon atoms to improve the thermal stability of an industrial lubricant composition as recited in claim 30, wherein the polyolefin thickener comprises an ethylene-propylene copolymer or a polyisobutylene.

32. The use of a P- branched, primary, saturated alcohol having 12 or more carbon atoms to improve the thermal stability of an industrial lubricant composition as recited in any of claims 29 to 31, wherein the polymeric thickening additive is present in an amount of 12 wt% to 45 wt% of the industrial lubricant composition.

33. The use of a P- branched, primary, saturated alcohol having 12 or more carbon atoms to improve the thermal stability of an industrial lubricant composition as recitedin any of claims 21 to 27, wherein the hydrocarbon oil comprises a mixture of a first hydrocarbon base oil having a kinematic viscosity at 100°C of 4 to 15 cSt or 4 cSt to 12 cSt and a second hydrocarbon base oil having a kinematic viscosity at 100°C of 20 to 35 cSt.

34. The use of a P- branched, primary, saturated alcohol having 12 or more carbon atoms to improve the thermal stability of an industrial lubricant composition as recited in any of claims 21 to 27, wherein the second base oil is present in an amount of up to 90 wt% or 55 wt% to 80 wt% of the industrial lubricant composition.

35. The use of a P- branched, primary, saturated alcohol having 12 or more carbon atoms to improve the thermal stability of an industrial lubricant composition as recited in any of claims 21 to 34, wherein the industrial lubricant composition has a kinematic viscosity at 40°C of 100 cSt to 680 cSt or 150 cSt to 680 cSt or 200 cSt to 480 cSt (ASTM D445).

36. The use of a P- branched, primary, saturated alcohol having 12 or more carbon atoms to improve the thermal stability of an industrial lubricant composition as recited in any of claims 21 to 35, wherein the metal-free phosphorous containing antiwear agent is selected from phosphites, phosphonates, alkylphosphate esters, amine phosphate salts, ammonium phosphate salts, and mixtures thereof.

37. The use of a P- branched, primary, saturated alcohol having 12 or more carbon atoms to improve the thermal stability of an industrial lubricant composition as recited in any of claims 21 to 36, wherein the hydrocarbon base oil is present in an amount of 60 wt% to 98 wt% of the lubricant composition.

38. The use of a P- branched, primary, saturated alcohol having 12 or more carbon atoms to improve the thermal stability of an industrial lubricant composition as recited in any of claims 21 to 37, wherein the P- branched, primary, saturated alcohol having 12 or more carbon atoms is present in an amount of 1 wt% to 20 wt% of the lubricant composition.

Images