WO2024019808A1

WO2024019808A1 - Lubricant additive composition

Info

Publication number: WO2024019808A1
Application number: PCT/US2023/023291
Authority: WO
Inventors: Mark Simonetti; Scott Bloom
Original assignee: Xg Industries
Priority date: 2022-07-21
Filing date: 2023-05-24
Publication date: 2024-01-25

Abstract

A lubricant additive composition includes particular amounts of a particle composition, a first polyhydroxy ester, a second polyhydroxy ester, a borate ester, and a dispersant. The lubricant additive composition can be used to treat a base oil to provide improved performance.

Description

LUBRICANT ADDITIVE COMPOSITION

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. Provisional Application No. 63/391,017, filed July 21, 2022, the content of which is incorporated by reference herein in its entirety.

BACKGROUND

[0001] Lubrication involves friction reduction by maintaining a film of a lubricant between adjacent surfaces that move with respect to each other. The lubricant film prevents direct contact of the adjacent surfaces, greatly reducing the coefficient of friction and wear of the surfaces. Commercially available lubricants include a mixture of a base grease and one or more additives. The additives can be selected to establish or enhance various properties of the lubricant. Because additives and the base grease may interact both physically and chemically, and because an additive may affect multiple properties of the base grease, formulation of additives can be complex.

[0002] For certain applications, reducing friction and wear can be especially desirable. Reducing friction losses can result in a variety of benefits, including improved fuel economy and reduced engine operating temperature. Reducing wear can also provide a variety of additional benefits, including extended life, reduced maintenance costs, and improved reliability. Furthermore, for certain applications, a lubricant that is substantially free of certain elements, such as phosphorous, sulfur, and metals such as molybdenum, antimony, and zinc (e.g., zinc dialkyldithiophosphate (ZDDP)) can be desirable for certain applications.

[0003] Many studies have been made on additives to provide reduced friction, wear, and improved load weld. Nonetheless, there remains a need for an improved lubricant additive composition that can provide improved performance. It would be particularly advantageous to provide an improved composition that is ashless and free of sulfur, phosphorus, molybdenum, antimony, and zinc.

SUMMARY

[0004] A lubricant additive composition comprises 0.1 to 5 weight percent of a particle composition having an average particle size of less than 1 micrometer; 10 to 94.3 weight percent of a first polyhydroxy ester; 5 to 30 weight percent of a second polyhydroxy ester; 0.5 to 5 weight percent of a borate ester; and 0.1 to 5 weight percent of a dispersant; wherein weight percent of each component is based on the total weight of the composition. [0005] A method for the manufacture of the lubricant additive composition comprises combining the components of the composition under conditions effective to provide the lubricant additive composition.

[0006] A method for the manufacture of the lubricant composition comprises combining a base oil with the lubricant additive composition.

[0007] A method for wear protection of a surface comprises applying the lubricant composition to at least a portion of a surface.

[0008] The above described and other features are exemplified by the following figures and detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The following figures are exemplary embodiments.

[0010] FIG. 1A is the ASTM D 130 copper corrosion strip standard.

[0011] FIG. IB is a plot of copper corrosion determined according to ASTM D4048 for various greases.

[0012] FIG. 2 is a plot of coefficient of friction determined according to ASTM D 183 for various greases.

[0013] FIG. 3 is a bar graph of wear scar size (millimeters, mm) and shows the results of four-ball wear test results for various greases, determined according to ASTM 2266.

[0014] FIG. 4 is a bar graph of load weld (kilograms force, kgf) and shows the results of four-ball load weld test results for various greases, determined according to ASTM 2596.

DETAILED DESCRIPTION

[0015] The present inventors have discovered an improved lubricant additive composition for use in grease that is free of various undesirable components, is environmentally friendly, is non-corrosive, and provides performance competitive with a lubricant additive composition that contains metals and other elements such as sulfur and phosphorus that would be preferably avoided. Specifically, the lubricant additive composition of the present disclosure can advantageously provide friction reduction, anti-wear properties, and improved load-weld. In a further advantageous feature, the composition can provide corrosion protection, believed to be due to the absence of heavy metals, without wishing to be bound by theory. The lubricant additive composition of the present disclosure comprises particular amounts of a particle composition, a first polyhydroxy ester, a second polyhydroxy ester, a borate ester, and a dispersant. The lubricant additive composition can advantageously provide a grease or a semifluid (also referred to herein as a lubricant composition) having reduced friction, reduced

7 corrosion, improved wear, and improved load-weld relative to the same grease without the lubricant additive composition.

[0016] The lubricant additive composition comprises a particle composition. The particle composition comprises a plurality of particles having an average particle size of less than or equal to 1 micrometer. For example, the particle composition can have an average particle size of 1 to 1000 nanometers, for example, 1 to 900 nanometers, or 1 to 800 nanometers, or 1 to 700 nanometers, or 1 to 600 nanometers, or 1 to 500 nanometers, or 1 to 400 nanometers or 1 to 300 nanometers, or 1 to 200 nanometers, or 1 to 100 nanometers, or 50 to 500 nanometers, or 50 to 400 nanometers, or 50 to 300 nanometers, or 50 to 250 nanometers, or 75 to 225 nanometers, or 100 to 200 nanometers. Particle size can be determined, for example, using screen analysis. Suitable particle compositions for use in the present disclosure are ashless. “Ashless” as used herein means that upon decomposition, the composition leaves little, if any, residue.

[0017] In an aspect, the particle composition can comprise boric acid, boric oxide, or a combination thereof. In an aspect, the boric acid, boric oxide, or combination thereof can have an average particle size of 1 micrometer or less, for example 1 to 500 nanometers, or 50 to 500 nanometers, or 50 to 250 nanometers, or 100 to 200 nanometers. The boric acid particles, boric oxide particles, or combination thereof may have a variety of shapes, and may be in the form of triangles, squares, spheres, hemispheres, rods, polygons, plates, rods, disks, or a combination thereof. The boric acid particles, boric oxide particles, or combination thereof may have various cross-sectional shapes, such as a rectangular, polygonal, oval, elliptical, or circular cross- sectional shape, or a combination thereof. The boric acid particles, boric oxide particles, or combination thereof may be produced by the low temperature jet-milling of commercially available boric acid, boric oxide, or a combination thereof. In an aspect, a combination or mixture of particles having different average particle size may be used. For example, a mixture of particles having an average particle size of 5 to 100 nanometers and particles having an average particle size of greater than 100 to 500 nanometers may be used.

[0018] In an aspect, the particle composition can comprise lanthanum oxide. The lanthanum oxide can comprise lanthanum oxide particles having an average particle size of, for example, 1 to 500 nanometers, or 50 to 500 nanometers, or 50 to 250 nanometers, or 100 to 200 nanometers.

[0019] In an aspect, the particle composition preferably comprises boric acid, boric oxide, or a combination thereof.

[0020] The particle composition can be present in the lubricant additive composition in an amount of 0.1 to 5 weight percent, based on the total weight of the composition. Within this range, the particle composition can be present in an amount of at least 0.2 weight percent, or at least 0.3 weight percent, or at least 0.4 weight percent, or at least 0.5 weight percent, or at least 0.6 weight percent, or at least 0.7 weight percent, or at least 0.8 weight percent, or at least 0.9 weight percent. Also within this range, the particle composition can be present in an amount of less than or equal to 4 weight percent, or less than or equal to 3 weight percent, or less than or equal to 2 weight percent, or less than or equal to 1.5 weight percent, or less than or equal to 1 weight percent. For example, the particle composition can be present in an amount of 0.1 to 4 weight percent, or 0.1 to 3 weight percent, or 0.1 to 2 weight percent, or 0.5 to 2 weight percent, or 0.5 to 1.5 weight percent, or 0.5 to 1.2 weight percent, or 0.75 to 1.1 weight percent, each based on the total weight of the composition.

[0021] The lubricant additive composition further includes a first polyhydroxy ester. The first polyhydroxy ester can be derived from a C3 -12 aliphatic polyol comprising 2 to 8 hydroxyl groups and a C5-36 aliphatic monocarboxylic acid.

[0022] The C₃ -12 aliphatic polyol can be represented by the general formula R(OH)_n, wherein R is a C3-12 hydrocarbyl group, optionally comprising one or more nitrogen or oxygen atoms, and n is 2 to 8. The polyhydroxy compound may contain one or more oxyalkylene groups, and, thus, the polyhydroxy compounds can include compounds such as poly etherpolyols. Exemplary C3-12 aliphatic polyols can include, but are not limited to, neopentyl glycol, 2,2-dimethyl-3-hydroxypropyl-2,2-dimethyl-3-hydroxypropionate, 2,2,4-trimethyl-l,5- pentanediol, trimethylolethane, trimethylolpropane, glycerol, pentaerythritol, dipentaerythritol, tripentaerythritol, diethylene glycol, propylene glycol, triethylene glycol, dipropylene glycol, triglycerol, sorbitol, inositol, 2,2,4-trimethyl-l,3-pentanediol, 1,2-, 1,3- and 1,4-butanediols, and the like, or a combination thereof. In a specific aspect, the C3-12 aliphatic polyol can be trimethylolpropane.

[0023] The C₅.36 aliphatic monocarboxylic acid can be represented by the general formula R COOH, wherein R¹ is an aliphatic hydrocarbyl group having 4 to 35 carbon atoms. Preferably, R¹ can be a straight or branched chain aliphatic hydrocarbyl group. In an aspect, the first polyhydroxy ester can be derived from a C12-36 aliphatic monocarboxylic acid. Exemplary monocarboxylic acids can include, but are not limited to, dodecanoic acid, stearic acid, lauric acid, behenic acid, oleic acid, lanolin acid, and the like or a combination thereof. In a specific aspect, the C5-36 aliphatic monocarboxylic acid of the first polyhydroxy ester can be oleic acid. In an aspect, the first polyhydroxy ester can comprise trimethylolpropane trioleate.

[0024] The first polyhydroxy ester can be present in the lubricant additive composition in an amount of 10 to 94.3 weight percent, based on the total weight of the composition. Within this range, the first polyhydroxy ester can be present in the lubricant additive composition in an amount of at least 20 weight percent, or at least 30 weight percent, or at least 40 weight percent, or at least 50 weight percent, or at least 60 weight percent, or at least 70 weight percent. Also within this range, the first polyhydroxy ester can be present in the lubricant additive composition in an amount of less than or equal to 94 weight percent, or less than or equal to 90 weight percent, or less than or equal to 85 weight percent, or less than or equal to 80 weight percent. For example, the first polyhydroxy ester can be present in the lubricant additive composition in an amount of 70 to 80 weight percent.

[0025] The lubricant additive composition further comprises a second polyhydroxy ester. The second polyhydroxy ester can be as described above for the first polyhydroxy ester, provided that the first polyhydroxy ester and the second polyhydroxy ester are not the same. In a specific aspect, the second polyhydroxy ester comprises a pentaerythritol ester of lanolin acid.

[0026] The second polyhydroxy ester can be present in the lubricant additive composition in an amount of 5 to 30 weight percent, based on the total weight of the lubricant additive composition. Within this range, the second polyhydroxy ester can be present in the lubricant additive composition in an amount of at least 10 weight percent, or at least 15 weight percent, or at least 20 weight percent, based on the total weight of the lubricant additive composition. Also within this range, second polyhydroxy ester can be present in the lubricant additive composition in an amount of less than or equal to 25 weight percent. For example, the second polyhydroxy ester can be present in the lubricant additive composition in an amount of 15 to 25 weight percent, based on the total weight of the lubricant additive composition.

[0027] The lubricant additive composition further comprises a borate ester. Without wishing to be bound by theory, the borate ester can act as a dispersant and can provide desirable anti- wear and antioxidant properties. Furthermore, the borate ester may also act to improve dropping point of the lubricant additive composition.

[0028] The borate ester may be a reaction product of a boron compound and an epoxy compound, a halohydrin compound, an epihalohydrin compound, a polyol, or a combination thereof. The polyol may be a mono-ol, diol, triol, or a higher polyol. Boron compounds suitable for preparing the borate ester include boric acid, including metaboric acid, HBO2, orthoboric acid, H3BO3, and tetraboric acid, H2B4O7, boric oxide, boron trioxide, or an alkyl borate. The borate ester may also be prepared from a boron halide. The borate ester may contain at least one hydrocarbyl group, specifically a C4-30 hydrocarbyl group.

[0029] Borated epoxides are described in detail in U.S. Pat. No. 4,584,115, the content of which is incorporated herein by reference in its entirety. The borated epoxide may be prepared by reacting an epoxide with boric acid or boron trioxide. Borated epoxides are not actually epoxides, but are the boron-containing reaction products of epoxides and may be a borate ester. The epoxides can be commercial mixtures of C14-16 or C14-I8 epoxides, which can be purchased from ELF-ATOCHEM or Union Carbide and which can be prepared from the corresponding olefins by known methods. Purified epoxy compounds such as 1 ,2- epoxyhexadecane can be purchased from Aldrich Chemical. The borated compounds may be prepared by blending the boron compound and the epoxide and heating them at a suitable temperature, e.g., 80 to 250° C, optionally in the presence of an inert liquid medium, until the desired reaction has occurred. A suitable borated epoxide is the borated epoxide of a Ci6 olefin.

[0030] Representative borate esters can include, but are not limited to, trimethyl borate, triethyl borate, tri-n-propyl borate, tri-n-butyl borate, triphenyl borate, triisopropyl borate, tri-t- amyl borate, triphenyl borate, trimethoxy boroxine, tri-2-cyclohexylcyclohexyl borate, a trialkanolamine borate such as triethanolamine borate or triisopropanolamine borate, manittol borate, and glycerol borate.

[0031] Additionally, other amino-containing borates and tertiary amine salts of boric acid may be useful. Such boron-containing compounds include, but are not limited to, 2-(beta- dimethylaminoisopropoxy)-4,5-dimethyl-l,3,2-dioxaborolane, 2-(beta- diethylaminoethoxy)4,4,6-trimethyl-l ,3,2-dioxaborinane, 2-(beta-dimethylaminoethoxy)-4,4,6- trimethyl-l,3,2-dioxaborinane, 2-(betha-diisopropylaminoethoxy-l,3,2-dioxaborinane, 2-(beta- dibutylaminoethoxy)-4-methyl- 1 ,3 ,2-dioxaborinane, 2-(gamma-dimethylaminopropoxy)- 1 ,3,6,9- tetrapxa-2-boracycloundecane, and 2-(beta-dimethylaminoethoxy)-4,4-(4-hydorxybutyl)- 1,3,2- dioxaborolane.

[0032] The borate ester may be a reaction product of a fatty oil and a C2-10 dialkanolamine, and subsequent reaction with a boric acid or other suitable reagent effective to form a borate ester. The fatty oil may be a glyceryl ester of a C6-30 fatty acid, specifically a glyceryl ester of a C12-22 fatty acid. In an aspect, the C2-10 dialkanolamine is diethanolamine. The borated ester may be a reaction product of 1 mole of the fatty oil and 1 to 2.5 moles of diethanolamine followed by reaction with boric acid as provided in U.S. Patent Publication No. 2004/0138073, the content of which in its entirety is herein incorporated by reference.

[0033] In an aspect, the borate ester can comprise a borated monoglyceride ethoxylated amide, for example a compound of the formula

or a compound of the formula

or a combination thereof. In the foregoing formulas, R² is independently at each occurrence H or a substituted or unsubstituted Ci-60 hydrocarbyl group and Y represents a fatty oil residue, specifically a residue of a glyceryl ester or a C12-22 fatty acid. In an aspect, the borate ester may be a reaction product of a fatty oil and a C2-10 dialkanolamine, and subsequent reaction with a boric acid or other suitable reagent effective to form a borate ester. The fatty oil may be a glyceryl ester of a C6-30 fatty acid, specifically a glyceryl ester of a C12-22 fatty acid. In an aspect, the C2-10 dialkanolamine can be diethanolamine. In an aspect, the borated ester may be a reaction product of 1 mole of the fatty oil and 1 to 2.5 moles of diethanolamine followed by reaction with boric acid as provided in U.S. Patent Publication No. 2004/0138073, the content of which in its entirety is herein incorporated by reference. An exemplary commercially available borate ester is VANLUBE 289, available from R.T. Vanderbilt Co., Norwalk, CT.

L0034J The borate ester can be present in the lubricant additive composition in an amount of 0.5 to 5 weight percent, based on the total weight of the lubricant additive composition. Within this range, the borate ester can be present in an amount of at least 1 weight percent, or at least 1.5 weight percent, or at least 2 weight percent, or at least 2.25 weight percent. Also within this range, the borate ester can be present in an amount of less than or equal to 4 weight percent, or less than or equal to 3 weight percent, or less than or equal to 2.75 weight percent. For example, the borate ester can be present in an amount of 2 to 3 weight percent, based on the total weight of the lubricant additive composition.

[0035] The lubricant additive composition further comprises a dispersant. Use of the dispersant promotes the formation of a dispersion, e.g., a colloidal dispersion, comprising the components of the composition. In addition, the dispersant can further prevent a deposit, e.g., a sludge or a varnish, by keeping various components of the composition suspended in a colloidal state. The dispersant can also improve the dropping point of the composition. While not wanting to be bound by theory, the dispersant can perform these functions via one or more means selected from: (1) solubilizing polar contaminants in their micelles; (2) stabilizing colloidal dispersions in order to prevent aggregation of their particles and their separation out of oil; (3) suspending such products, if they form, in the bulk lubricant; (4) modifying soot to minimize its aggregation and oil thickening; and (5) lowering surface/interfacial energy of undesirable materials to decrease their tendency to adhere to surfaces. The undesirable materials are typically formed as a result of oxidative degradation of the lubricant, the reaction of chemically reactive species such as carboxylic acids with the metal surfaces in the engine, or the decomposition of thermally unstable lubricant additive compositions such as, for example, extreme pressure agents.

[0036] A dispersant generally comprises three distinct structural features: (1) a hydrocarbyl group; (2) a polar group; and (3) a connecting group or a link.

[0037] The hydrocarbyl group can be polymeric in nature, and can have a molecular weight of at least 1,000 grams per mole (g/mol), or at least 1,500 g/mol, or at least 2,000 g/mol, or at least 3,000 g/mol, or at least 5,000 g/mol, or at least 8,000 g/mol. A variety of olefins, such as polyisobutylene, polypropylene, polyalphaolefins, or a combination thereof, can be used to make a suitable polymeric dispersant. In an aspect, the polymeric dispersant can be a polyisobutylene-derived or a polyester-derived dispersant. The number average molecular weight of the polyisobutylene or the polyester in such dispersants can be, for example, 500 to 3,000 g/mole, or 800 to 2,000 g/mol, or 1,000 to 2,000 g/mol, or 1,000 to 2,500 g/mol. In an aspect, the polar group in the dispersant is nitrogen- or oxygen-derived. Nitrogen-based dispersants are typically derived from amines, which can include poly amines. The amines from which the nitrogen-based dispersants are derived are often polyalkylenepolyamines, such as, for example, diethylenetriamine and trithylene tetramine. Amine-derived dispersants are also called nitrogen- or amine-dispersants, while those derived from alcohol are also called oxygen or ester dispersants. In an aspect, oxygen-based dispersants can be neutral and the amine-based dispersants can be basic.

[0038] Non-limiting examples of suitable dispersants can include substituted or unsubstituted alkenyl succinimide, an alkenyl succinimide derived by post-treatment with ethylene carbonate or boric acid, a succinimide, succinate esters, succinate ester-amide, pentaerythritol, phenate-salicylate or an analog thereof, an alkali metal or mixed alkali metal salt thereof, a polyamide ashless dispersant, a benzylamine, a Mannich type dispersant, or a combination thereof, in addition to the borate ester disclosed above.

[0039] Representative polymeric dispersants can include poly(styrene-co-lauryl methacrylate-co-sulfoethyl methacrylate), poly(vinyltoluene-co-lauryl methacrylate-co-lithium methacrylate), poly(vinyltoluene-co-lauryl methacrylate-co-lithium methacrylate), poly(styrene- co-lauryl methacrylate-co-lithium methacrylate), poly(t-butylstyrene-co-styrene-co-lithium sulfoethyl methacrylate), poly(t-butylstyrene-co-lauryl methacrylate-co-lithium methacrylate), poly(t-butylstyrene-co-lithium methacrylate), poly(t-butylstyrene-co-lauryl methacrylate-co- lithium methacrylate-co-methacrylic acid), and poly(vinyltoluene-co-lauryl methacrylate-co- methacryloyloxyethyltrimethylammonium p-toluenesulfonate).

[0040] In a specific aspect, the dispersant can be a borated dispersant. The borated dispersant can comprise a borate or a borate ester in addition to the borate ester disclosed above.

[0041] The borated dispersant comprises the three structural features described above, and has further been borated (e.g., by treatment with boric acid).

[0042] In a specific aspect, the borated dispersant can comprise a polyisobutylene succinic acid or anhydride and a polyamine, wherein the dispersant is post-treated with maleic anhydride and boric acid. The polyisobutylene succinic acid or anhydride can have, for example, a molecular weight of 1,000 to 2,500 grams per mole. A representative suitable commercially available borated dispersant is HITEC 643d, with 0.8 weight percent boron and 1.6 weight percent nitrogen, available from Afton Chemical.

[0043] The dispersant can be present in the lubricant additive composition in an amount of 0.1 to 5 weight percent, based on the total weight of the lubricant additive composition. Within this range, the borated dispersant can be present in an amount of at least 0.2 weight percent, or at least 0.25 weight percent, or at least 0.3 weight percent, or at least 0.35 weight percent, or at least 0.4 weight percent, based on the total weight of the lubricant additive composition. Also within this range, the borated dispersant can be present in an amount of less than or equal to 4.5 weight percent, or less than or equal to 4 weight percent, or less than or equal to 3 weight percent, or less than or equal to 2 weight percent, or less than or equal to 1.5 weight percent, or less than or equal to 1.25 weight percent, or less than or equal to 1 weight percent, or less than or equal to 0.8 weight percent, or less than or equal to 0.75 weight percent, or less than or equal to 0.6 weight percent, or less than or equal to 0.55 weight percent, or less than or equal to 0.5 weight percent, based on the total weight of the lubricant additive composition. For example, the borated dispersant can be present in an amount of 0.1 to 1 weight percent, based on the total weight of the lubricant additive composition.

[0044] In a specific aspect, the lubricant additive composition can comprise 0.5 to 1.5 weight percent of the particle composition; 70 to 80 weight percent of the first polyhydroxy ester; 15 to 25 weight percent of the second polyhydroxy ester; 2 to 3 weight percent of the borate ester; and 0.1 to 1 weight percent of the dispersant, based on the total weight of the lubricant additive composition. The particle composition can comprise boric acid, boric oxide, or a combination thereof; the first polyhydroxy ester can comprise trimethylolpropane trioleate; the second polyhydroxy ester can comprise a pentaerythritol ester of lanolin acid; the borate ester can comprise a borated monoglyceride ethoxylated amide; and the dispersant can comprise a polyisobutylene succinic acid or anhydride and a polyamine, wherein the dispersant is treated with maleic anhydride and boric acid.

[0045] The lubricant additive composition can optionally further comprise an additional chemical agent or other type of material to impart additional desired properties, provided that the desired properties of the lubricant additive composition are not significantly adversely affected by the presence of the additional chemical agent or additive. Exemplary additional chemical agents can include, for example, a friction reducing agent, anti-wear or extreme-pressure agent, anti-corrosion agent, detergent, antioxidant, suspension agent, thixotropic agent, pour point depressant, or metal deactivator to provide a lubricant composition suitable for use in a particular application.

[0046] Advantageously, the lubricant additive composition can be free of sulfur, phosphorus, a metal (e.g., tungsten, molybdenum, antimony, nickel, chrome, zinc, antimony, lithium, calcium, aluminum, magnesium, and the like), or a combination thereof. In an aspect, a content of sulfur in the lubricant additive is less than 1 part per million (ppm), 0.001 ppm to 1 ppm, or 0.01 ppm to 0.1 ppm. In an aspect, a content of phosphorus in the lubricant additive is less than 1 part per million (ppm), 0.001 ppm to 1 ppm, or 0.01 ppm to 0.1 ppm. In an aspect, a content of the metal in the lubricant additive is less than 1 part per million (ppm), 0.001 ppm to 1 ppm, or 0.01 ppm to 0.1 ppm. In an aspect, a content of molybdenum and/or tungsten in the lubricant additive is less than 1 part per million (ppm), 0.001 ppm to 1 ppm, or 0.01 ppm to 0.1 ppm. In an aspect, molybdenum or tungsten are not detected in the lubricant additive composition when analyzed by atomic absorption spectroscopy. In an aspect, molybdenum or tungsten are not detected in the lubricant additive composition when analyzed by atomic absorption spectroscopy. In an aspect, the composition can comprise less than 1 part per million (ppm), 0.001 ppm to 1 ppm, or 0.01 ppm to 0.1 ppm, or can exclude, tungsten disulfide, molybdenum disulfide, or both. In an aspect, the composition comprises a metal of Group VI- XII of the periodic table in an amount of less than 1 part per million (ppm), 0.001 ppm to 1 ppm, or 0.01 ppm to 0.1 ppm. Preferably, a metal of Group VI-XII of the periodic table is absent from the lubricant additive composition. The lubricant additive composition can minimize or exclude a metal deactivator, e.g., a compound which reduces the activity of the metal. Some non- limiting examples of metal deactivators which can be minimized or excluded from the present composition include, but are not limited to, disalicylidene propylenediamine, a triazole, a thiadiazole, or a mercaptobenzimidazole. A specific example of a metal deactivator can include N,N-bis(2-ethylhexyl)-ar-methyl- IH-benzo triazole- 1 -methanamine, commercially available as CUV AN 303, from Vanderbilt Chemicals, LLC. [0047] A method for the manufacture of the lubricant additive composition represents another aspect of the present disclosure. The lubricant additive composition can be prepared by combining the components of the composition under conditions effective to provide the lubricant additive composition. For example, the method can comprise combining the particle composition, the first polyhydroxy ester, the second polyhydroxy ester in liquid form, the borate ester, and the dispersant to provide a mixture. The mixture can be subjected to high-shear conditions to provide the lubricant additive composition.

[0048] The components of the composition can be mixed stepwise or simultaneously. For example, in an aspect, the particle composition and the first polyhydroxy ester can be combined to provide a first mixture. The particle composition can be present in the first mixture in an amount of 5 to 50 weight percent, or 10 to 40 weight percent or 15 to 30 weight percent, or 20 to 30 weight percent, based on the total weight of the first mixture. The first polyhydroxy ester can be present in the first mixture in an amount of 50 to 95 weight percent, or 60 to 90 weight percent, 70 to 85 weight percent, or 70 to 80 weight percent, based on the total weight of the first mixture. The first mixture can be subsequently combined with the second polyhydroxy ester in liquid form, the borate ester, and the dispersant to provide a second mixture. Optionally, an additional amount of the first polyhydroxy ester can be added to the second mixture (e.g., to adjust the relative amounts of the components) to provide the lubricant additive composition.

[0049] The conditions effective to provide the lubricant additive composition can comprise milling the composition, for example for 1 to 24 hours at a temperature of 75 to 120°C. In an aspect, the method can comprise milling the first mixture (e.g., comprising the particle composition and the first polyhydroxy ester) prior to combining with the second polyhydroxy ester in liquid form, the borate ester, and the dispersant. In an aspect, the method can comprise milling the second mixture (e.g., comprising the particle composition, the first polyhydroxy ester, the second polyhydroxy ester in liquid form, the borate ester, and the dispersant).

[0050] The second polyhydroxy ester is preferably combined with the components of the composition in liquid form. Accordingly, if needed, the method can further comprise heating the second polyhydroxy ester to a temperature greater than the melting point of the second polyhydroxy ester to provide the second polyhydroxy ester as a liquid. The liquid second polyhydroxy ester can then be combined with the remaining components of the composition.

[0051] In an aspect, the conditions effective to provide the lubricant additive composition can comprise homogenizing the composition under high-shear conditions. Without wishing to be bound by theory, combining the components in the high shear mixer can reduce or eliminate aggregation within the composition. Combining the components under high shear may comprise mixing with a KADY mill or a DAYMAX mixer, for example, at 2000 to 12000 RPM, specifically 2500 to 10000 RPM, and for 1 to 100 minutes, specifically 5 to 80 minutes. A temperature of the mixture during the high shear mixing may be 20 to 200°C, specifically 30 to 180°C, more specifically 40 to 160°C. Tn an aspect, the method can comprise homogenizing the second mixture (e.g., comprising the particle composition, the first polyhydroxy ester, the second poly hydroxy ester in liquid form, the borate ester, and the dispersant). In an aspect, the homogenizing and the aforementioned milling can be conducted simultaneously.

[0052] In an aspect, the conditions effective to provide the lubricant additive composition can comprise ultrasonically mixing the lubricant additive composition. Without wishing to be bound by theory, it is believed that ultrasonication of the second mixture can stabilize the composition. A representative ultrasonic mixer is a SONOLATOR or an ultrasonic wand. The ultrasonic mixing may be conducted for 1 to 100 minutes, specifically 5 to 80 minutes, more specifically 10 to 60 minutes. A temperature of the mixture during the ultrasonic mixing may be 20 to 200°C, specifically 30 to 180°C, more specifically 40 to 160°C. The ultrasonically mixing may be conducted before or after the blending. The resulting composition can be provided in the form of a solution or dispersion.

[0053] In an aspect, the ultrasonic mixing can be replaced with a high-pressure homogenizer. High pressure homogenization processes can reduce particle size by subjecting the particle population to one or more of cavitation, shear, and impact within a homogenization chamber under operating pressures from 5,000 psi to 45,000 psi, for example, 5,000, 10,000, 15,000, 20,000, 25,000, 30,000, 35,000, 40,000 or 45,000 psi. In an aspect, when used, a high- pressure homogenization process can be performed at 40,000 to 45,000 psi, or at 45,000 psi or more. Exemplary high-pressure homogenizers can include those available from Bee International, such as the DeBEE 2000 series homogenizers.

[0054] In a specific aspect, the particle composition and the first polyhydroxy ester can be mixed in a ball mill under conditions effective to provide the particle composition having a desired size (e.g., having an average size of less than 1 micrometer). The first mixture can then be combined with the second polyhydroxy ester in liquid form, the borate ester, and the dispersant to provide the second mixture, preferably in a high shear mixer. The second mixture can further be ultrasonically mixed.

[0055] In an aspect, the lubricant additive composition can be optically transparent. In an aspect, the method can further comprise additional high shear mixing until the desired transparency of the lubricant additive composition is obtained. Use of a KADY mill mixer is mentioned.

[0056] An exemplary method for the manufacture of the lubricant additive composition described herein is further described in the working examples below. [0057] The lubricant additive composition can be combined with a base oil to provide a lubricant composition. A lubricant (e.g., a grease or a semifluid lubricant) comprising the lubricant additive composition described herein represents another aspect of the present disclosure.

[0058] The lubricant can comprise a major proportion of a base oil and a minor proportion of the lubricant additive composition. As used herein, the term “major proportion” refers to a concentration of the base oil within the lubricant composition of at least 50 weight percent. For example, the lubricant can comprise 55 to 99.99 weight percent, or 55 to 99.95 weight percent, or 55 to 99.9 weight percent, or 55 to 95 weight percent, or 55 to 90 weight percent, or 60 to 85 weight percent of the base grease, each based on the total weight of the lubricant. In an aspect, the lubricant can comprise 75 to 99.99 weight percent, or 80 to 99.99 weight percent, or 85 to 99.99 weight percent, or 90 to 99.99 weight percent, or 95 to 99.99 weight percent of the base grease, and 0.01 to 25 weight percent, or 0.01 to 20 weight percent, or 0.01 to 15 weight percent, or 0.01 to 10 weight percent, or 0.01 to 5 weight percent of the lubricant additive composition, each based on the total weight of the lubricant composition.

[0059] The base oil can comprise a base stock of one or more of Groups I-V as specified in the American Petroleum Institute (API) Publication 1509, Fourteenth Edition, December 1996 (i.e., API Base Oil Interchangeability Guidelines for Passenger Car Motor Oils and Diesel Engine Oils), which is incorporated herein by reference in its entirety. The API guideline defines a base stock as a lubricant component that may be manufactured using a variety of different processes. Groups I (solvent refined mineral oils), II (hydrocracked mineral oils) and III (severely hydrocracked based oils) base stocks are mineral oils, each with specific ranges of the amount of saturates, sulfur content, and viscosity index. Group IV base stocks are polyalphaolefins (PAOs). Group V base stocks include all other base stocks not included in Group I, II, III, or IV and include esters and naphthenes. A vegetable oil may be used.

[0060] In an aspect, the base oil can comprise a base stock of Groups I, II, III, IV, V, or a combination thereof. In an aspect, the base oil can comprise a base stock of Group II, III, IV, or a combination thereof. In yet another aspect the base oil can comprise a base stock of Group II, III, IV, or a combination thereof. The base oil may have a kinematic viscosity of 1 to 150 centistokes (cSt), specifically 2 cSt to 100 cSt, more specifically 4 cSt to 50 cSt at 100°C.

[0061] The base oil may comprise a natural oil having a viscosity suitable for lubrication, a synthetic oil having a viscosity suitable for lubrication, or a combination thereof. In an aspect, the base oil can include a base stock obtained by isomerization of a synthetic wax and a slack wax, as well as hydrocrackate base stock produced by hydrocracking (rather than solvent extracting) the aromatic and polar components of crude oil. In an aspect, the base oil of lubricating viscosity can include a natural oil such as an animal oil, vegetable oil, mineral oil (e.g., liquid petroleum oil or solvent treated or acid-treated mineral oil of the paraffinic, naphthenic, or mixed paraffinic-naphthenic types), an oil derived from coal or shale, or a combination thereof. Some non-limiting examples of animal oils include bone oil, lanolin, fish oil, lard oil, dolphin oil, seal oil, shark oil, tallow oil, and whale oil. Some non-limiting examples of vegetable oils include castor oil, olive oil, peanut oil, rapeseed oil, corn oil, sesame oil, cottonseed oil, soybean oil, sunflower oil, safflower oil, hemp oil, linseed oil, tung oil, oiticica oil, jojoba oil, and meadow foam oil. Such oils may be partially or fully hydrogenated.

[0062] In an aspect the synthetic oil of lubricating viscosity can include a hydrocarbon oil and/or a halo-substituted hydrocarbon oil such as a polymerized and/or cross-linked olefin, an alkylbenzene, a polyphenyl, an alkylated diphenyl ether, an alkylated diphenyl sulfide, a derivative, analogues or homologues thereof, or a combination thereof. In an aspect the synthetic oil can include an alkylene oxide polymer, a cross-linked polymer, a copolymer, or a derivative thereof wherein the terminal hydroxyl groups can be modified by esterification or etherification. In an aspect the synthetic oil can include the ester of a dicarboxylic acids with a variety of alcohols. In an aspect the synthetic oil can include an ester made from a C5-12 monocarboxylic acid and a polyol and a polyol ether. In an aspect the synthetic oil can include a tri-alkyl phosphate ester oil such as tri-n-butyl phosphate or tri-iso-butyl phosphate.

[0063] In an aspect the synthetic oil can include a silicon-based oil (such as the polyalkyl-, polyaryl-, polyalkoxy-, poly aryloxy- siloxane oil or a silicate oil). In an aspect the synthetic oil can include a liquid ester of a phosphorus-containing acid, a polymeric tetrahydrofuran, or a polyalphaolefin.

[0064] A base oil derived from the hydroisomerization of wax may also be used, either alone or in combination with the aforesaid natural and/or synthetic base oil. Such wax isomerate oil is produced by the hydroisomerization of natural or synthetic waxes or mixtures thereof over a hydroisomerization catalyst.

[0065] In an aspect, the base oil can comprise a polyalphaolefin (PAO). Non-limiting examples of suitable polyalphaolefins include those derived from octene, decene, or a combination thereof. The polyalphaolefin may have a viscosity of 1 to 150, specifically 2 to 100, more specifically 4 to 75, or 8 to 50 centistokes at 100°C. In some instances, the poly- alpha-olefin may be used together with another base oil such as a mineral oil. A polyalphaolefin comprising 1 -decene is specifically mentioned. In an aspect the polyalphaolefin comprises 75 wt% to 85 wt% decene trimer, 3 wt% to 23 wt% decene tetramer, and 0.1 wt% to 4 wt% pentamer or higher oligomer. SYNFLUID, a product of Chevron Phillips Chemical Company, specifically SYNFLUID PAO 4 cSt is specifically mentioned. [0066] In an aspect the base oil can comprise a polyalkylene glycol or a polyalkylene glycol derivative, where a terminal hydroxyl group of the polyalkylene glycol may be modified by esterification, etherification, or acetylation. Non-limiting examples of suitable polyalkylene glycols include polyethylene glycol, polypropylene glycol, polyisopropylene glycol, or a combination thereof. Non- limiting examples of suitable polyalkylene glycol derivatives include an ether of a poly alkylene glycol (e.g., methyl ether of polyisopropylene glycol, diphenyl ether of polyethylene glycol, or diethyl ether of polypropylene glycol), a mono- and polycarboxylic ester of a polyalkylene glycol, or a combination thereof. In some instances, the polyalkylene glycol or polyalkylene glycol derivative may be used together with a base oil such as poly- alpha-olefin or a mineral oil.

[0067] In an aspect the base oil can comprise an ester of a dicarboxylic acid (e.g., phthalic acid, succinic acid, an alkyl succinic acid, an alkenyl succinic acid, maleic acid, azelaic acid, suberic acid, sebacic acid, fumaric acid, adipic acid, linoleic acid dimer, malonic acid, an alkyl malonic acid, or an alkenyl malonic acid) with an alcohol (e.g., butyl alcohol, hexyl alcohol, dodecyl alcohol, 2-ethylhexyl alcohol, ethylene glycol, diethylene glycol monoether, or propylene glycol). Non-limiting examples of these esters include dibutyl adipate, di(2- ethylhexyl) sebacate, di-n-hexyl fumarate, dioctyl sebacate, diisooctyl azelate, diisodecyl azelate, dioctyl phthalate, didecyl phthalate, dieicosyl sebacate, or the 2-ethylhexyl diester of linoleic acid dimer.

[0068] In an aspect the base oil can comprise a hydrocarbon prepared by the Fischer- Tropsch process. The Fischer-Tropsch process provides a hydrocarbon from gases containing hydrogen and carbon monoxide using a Fischer-Tropsch catalyst. These hydrocarbons may require further processing in order to be useful as a base oil. For example, the hydrocarbon may be dewaxed, hydroisomerized, and/or hydrocracked.

[0069] In an aspect, the base oil can comprise an unrefined oil, a refined oil, a rerefined oil, or a combination thereof. An unrefined oil is obtained directly from a natural or synthetic source without further purification treatment. Non-limiting examples of the unrefined oil includes a shale oil obtained directly from a retorting operation, a petroleum oil obtained directly from primary distillation, or an ester oil obtained directly from an esterification process and used without further treatment. A refined oil is similar to the unrefined oil except that the former have been further treated by one or more purification processes to improve one or more properties. Such processes include solvent extraction, secondary distillation, acid or base extraction, filtration, and percolation. The rerefined oil is obtained by applying to a refined oil processes similar to those used to obtain the refined oil. Such rerefined oils are also known as reclaimed or reprocessed oils and often are additionally treated by processes directed to removal of spent additives and oil breakdown products.

[0070] An aspect in which the base oil is an olefin, specifically a polyalphaolefin, more specifically a polyalphaolefin having viscosity at 100°C of 4 centistokes, is specifically mentioned.

[0071] Greases can be divided into 9 NLGI (National Lubricating Grease Institute) classes or grades commonly used in the field of greases according to their consistency. The grades are shown in the table below.

[0072] Exemplary base oil suitable for use in the present lubricant composition can preferably have a consistency of 265 to 430, or 310 to 430, or 265 to 340 tenths of a millimeter, determined according to ASTM D217. In an aspect, the base oil can be grade NLGI 00, 0, 1 or 2.

[0073] In an aspect, the base oil can further comprise a thickener. Suitable organic thickeners can include, without limitation, a metal or mineral soap or complex soap, a polyurea, another polymer, or a combination thereof. Representative soaps or soap complexes include an aluminum benzoate-stearate complex, an aluminum benzoate-behenate-arachidate complex, a lithium azelate- stearate complex, a lithium sebecate-stearate or behenate complex, a lithium adipate-stearate complex, a calcium acetate-stearate complex, and a calcium sulfonate-stearate complex. Other aluminum, calcium, lithium, or other mineral soaps or complex soaps and combinations thereof can equally well be used.

[0074] In an aspect, the thickener can comprise a lithium complex thickener, for example a lithium soap derived from a fatty acid containing an epoxy group or ethylenic unsaturation and a dilithium salt derived from a straight chain dicarboxylic acid or, in an aspect, a lithium salt derived from a hydroxy-substituted carboxylic acid such as salicylic acid.

[0075] The lubricant composition can also contain other suitable additives, for example antioxidants, such as aminated or phenolic antioxidants, anti-rust additives which can be oxygenated compounds such as esters, for example sorbitan monoleate, oxidized waxes, copper passivators, and the like, provided that the presence of such additives does not significantly adversely affect a desired property of the lubricant composition. When present, these different compounds can be included in the composition in an amount of less than 1 weight percent, or less than 0.5 weight percent, based on a total weight of the lubricant composition.

[0076] The lubricant composition can be prepared by combining the base oil with the lubricant additive composition described herein.

[0077] Also provided is a method for wear protection of a surface, for example a metal surface. The method comprises applying the lubricant composition comprising the lubricant additive composition of the present disclosure to at least a portion of a surface. In an aspect, the surface can be a metal surface.

[0078] The present inventors have unexpectedly found that the lubricant composition of the present disclosure can advantageously provide reduced friction, good wear performance, and improved load-weld. Accordingly, a significant improvement is provided by the present disclosure.

[0079] This disclosure is further illustrated by the following examples, which are nonlimiting.

EXAMPLES

Lubricant Additive Preparation

[0080] A lubricant additive composition was prepared by combining boric acid (33 grams), trimethylolpropane trioleate (2622 grams, obtained as TRUVIS 3055), pentaerythritol ester of lanolin fatty acids (745.2 grams, obtained as PENTALAN), borate ester (88.95 grams, obtained as VANLUBE 289), and a borated dispersant (14.56 grams, obtained as HITEC 643d) under conditions effective to provide the lubricant additive composition. The boric acid and the trimethylolpropane trioleate were combined to form a first mixture. The first mixture was ball milled for 10 hours at 90°C using yttrium oxide media in a stainless-steel mill. Separately, PENTALAN was heated to 100°C. The heated PENTALAN was combined with the first mixture, the borate ester, and the borated dispersant in a KADY mill to provide a second mixture. The second mixture was milled in the KADY mill for 10-30 minutes until dissolution or dispersion of the boric acid. The second mixture was then transferred to a SONOLATOR, and additional trimethylolpropane trioleate was added to obtain the final lubricant additive composition. The lubricant additive composition was treated with the SONOLATOR for 1 to 2 hours until visually transparent.

[0081] Copper corrosion of the lubricant additive composition was assessed according to ASTM D 130/IP 154 and compared to a standard lithium complex grease NLGI #2, and three molybdenum containing additive packages. Copper corrosion is indicated using a scale of 1 to 4, where a result of 1 represents slight tarnish and a result of 4 represents copper corrosion as provided by the ASTM D 130 Copper Strip Corrosion Standard shown in FIG. 1A. The results are shown in FIG. I B. From FIG. IB, it can be seen that the lubricant composition according to the present disclosure (indicated as “composition 1”) provides a significant reduction in copper corrosion compared to the molybdenum-containing additive packages. It can also be seen that the corrosion was similar to that of the grease alone (i.e., containing no additive package).

[0082] Lubricant compositions were prepared according to Table 1. Component amounts are expressed in weight percent based on the total weight of the composition. The lubricant additive composition according to the present disclosure and prepared as described above is referred to as “Composition 1’’. “Moly A’’ is a commercially available friction reducer comprising molybdenum di-n-butyldithiocarbamate, available as MOLYVAN A from Vanderbilt Chemicals, LLC. “Moly B” is a commercially available friction reducer comprising molybdenum di(2-ethylhexyl)phosphorodithioate, available as MOLYVAN L from Vanderbilt Chemicals, LLC. “Moly C” is molybdenum disulfide, CAS Reg. No. 01317-33-5, having a particle size of 10 to 30 micrometers, available from Rose Mill Co.

Table 1

“*” denotes a comparative example

[0083] The lubricant compositions were characterized in terms of coefficient of friction, determined according to ASTM D5183. The results are shown in FIG. 2, where it can be seen that the lubricant including the additive composition according to the present disclosure can provide a coefficient of friction of 0.05 to 0.06.

[0084] The composition of examples 1*, 5 and 6 were further characterized using a 4- ball wear test according to ASTM 2266, and a 4-ball load weld test according to ASTM 2596. The results are shown in FIG. 3 and 4, respectively. As shown in FIG. 3, when present in the grease composition in an amount of 1 to 3 weight percent, the lubricant composition exhibited a decrease in wear scar (reported in millimeters, mm) relative to the base grease not including any additives. FIG. 4 shows that when present in the grease composition in an amount of 1 to 3 weight percent, the lubricant composition exhibited an increase in load weld (kgf) relative to the base grease, not including any additives.

[0085] Accordingly, the lubricant additive composition provided by the present disclosure avoids inclusion of metals, such as molybdenum, tungsten, antimony, and zinc, as well as elements such as phosphorus and sulfur, associated with adverse environmental effects. The composition also has low toxicity and good biodegradability, and has been demonstrated as an alternative friction modifier having improved wear and improved load-weld, wherein the use of agents containing molybdenum, sulfur, phosphorus, graphite, or antimony can be avoided. A significant improvement is therefore provided by the present disclosure.

[0086] This disclosure further encompasses the following aspects.

[0087] Aspect 1: A lubricant additive composition comprising: 0.1 to 5 weight percent of a particle composition; 10 to 94.3 weight percent of a first polyhydroxy ester; 5 to 30 weight percent of a second polyhydroxy ester; 0.5 to 5 weight percent of a borate ester; and 0.1 to 5 weight percent of a dispersant; wherein weight percent of each component is based on the total weight of the composition.

[0088] Aspect 2: The lubricant additive composition of aspect 1, wherein the particle composition comprises boric acid, boric oxide, or a combination thereof.

[0089] Aspect 3: The lubricant additive composition of aspect 1 or 2, wherein the particle composition comprises lanthanum oxide.

[0090] Aspect 4: The lubricant additive composition of any of aspects 1 to 3, wherein the particle composition has an average particle size of less than 1 micrometer, preferably SO- SOO nanometers.

[0091] Aspect 5: The lubricant additive composition of any of aspects 1 to 4, wherein the first and second polyhydroxy ester are each independently derived from a C3-12 aliphatic polyol comprising 2 to 8 hydroxyl groups and a C5-36 aliphatic monocarboxylic acid, and wherein the first and second polyhydroxy ester are not the same.

[0092] Aspect 6: The lubricant additive composition of any of aspects 1 to 5, wherein the first and second polyhydroxy ester are each independently derived from a polyol comprising neopentyl glycol, 2,2-dimethyl-3-hydroxypropyl-2,2-dimethyl-3-hydroxypropionate, 2,2,4- trimethyl-l,5-pentanediol, trimethylolethane, trimethylolpropane, glycerol, pentaerythritol, dipentaerythritol, tripentaerythritol; and a C12-36 aliphatic monocarboxylic acid.

[0093] Aspect 7: The lubricant additive composition of any of aspects 1 to 6, wherein the first polyhydroxy ester comprises trimethylolpropane trioleate and the second polyhydroxy ester comprises a pentaerythritol ester of lanolin acid.

[0094] Aspect 8: The lubricant additive composition of any of aspects 1 to 7, wherein the borate ester is a borated monoglyceride ethoxylated amide.

[0095] Aspect 9: The lubricant additive composition of any of aspects 1 to 8, wherein the dispersant comprises a polymeric polyamine dispersant. [0096] Aspect 10: The lubricant additive composition of any of aspects 1 to 9, wherein the dispersant comprises a polyisobutylene succinic acid or anhydride and a polyamine, wherein the dispersant is treated with maleic anhydride and boric acid.

[0097] Aspect 11: The lubricant additive composition of aspect 10, wherein the polyisobutylene succinic acid or anhydride has a molecular weight of 1,000 to 2,500 grams per mole.

[0098] Aspect 12: The lubricant additive composition of any of aspects 1 to 11, comprising 0.5 to 1.5 weight percent of the particle composition; 70 to 80 weight percent of a first polyhydroxy ester; 15 to 25 weight percent of a second polyhydroxy ester; 1 to 3 weight percent of the borate ester; and 0.1 to 1 weight percent of the dispersant.

[0099] Aspect 13: The lubricant additive composition of aspect 12, wherein the particle composition comprises boric acid, boric oxide, or a combination thereof; the first polyhydroxy ester comprises trimethylolpropane trioleate; the second polyhydroxy ester comprises a pentaerythritol ester of lanolin acid; the borate ester comprises a borated monoglyceride ethoxylated amide; and the dispersant comprises a polyisobutylene succinic acid or anhydride and a polyamine, wherein the dispersant is treated with maleic anhydride and boric acid.

[0100] Aspect 14: The lubricant additive composition of any of aspects 1 to 13, wherein the composition is free of sulfur, phosphorus, metal, or a combination thereof.

[0101] Aspect 15: A lubricant composition comprising the lubricant additive composition of any of aspects 1 to 14.

[0102] Aspect 16: The lubricant composition of aspect 15, comprising a major proportion of a base oil and a minor proportion of the lubricant additive composition.

[0103] Aspect 17: The lubricant composition of aspect 16, comprising 55 to 99.99 weight percent of the base oil and 0.01 to 45 weight percent of the lubricant additive composition, wherein weight percent is based on the total weight of the lubricant composition.

[0104] Aspect 18: A method for the manufacture of the lubricant additive composition of any of aspects 1 to 14, the method comprising: combining the components of the composition under conditions effective to provide the lubricant additive composition.

[0105] Aspect 19: The method of aspect 18, wherein combining the components of the composition comprises combining the particle composition, the first polyhydroxy ester, the second poly hydroxy ester in liquid form, the borate ester, and the dispersant to provide a mixture; and mixing the mixture under high-shear to provide the lubricant additive composition.

[0106] Aspect 20: The method of aspect 18, wherein combining the components comprises combining the particle composition and the first polyhydroxy ester to provide a first mixture; combining the first mixture, the second polyhydroxy ester in liquid form, the borate ester, and the dispersant to provide a second mixture.

[0107] Aspect 21 : The method of any of aspects 18 to 20, further comprising adding an additional amount of the first polyhydroxy ester to provide the lubricant additive composition.

[0108] Aspect 22: The method of any of aspects 18 to 21, wherein conditions effective to provide the lubricant additive composition comprise milling, preferably for 1 to 24 hours at a temperature of 75 to 120°C.

[0109] Aspect 23: The method of any of aspects 18 to 22, further comprising heating the second polyhydroxy ester to a temperature greater than the melting point of the second polyhydroxy ester to provide the second polyhydroxy ester as a liquid.

[0110] Aspect 24: The method of any of aspects 18 to 23, wherein conditions effective to provide the lubricant additive composition comprise homogenizing the lubricant additive composition under high shear.

[0111] Aspect 25: The method of any of aspects 18 to 24, wherein conditions effective to provide the lubricant additive composition comprise ultrasonically mixing the lubricant additive composition.

[0112] Aspect 26: A method for the manufacture of the lubricant composition of any of aspects 15 to 17, the method comprising: combining a base grease with the lubricant additive composition of any of aspects 1 to 14.

[0113] Aspect 27: A method for wear protection of a surface, the method comprising: applying the lubricant composition of any of aspects 15 to 17 to at least a portion of a surface.

[0114] The compositions, methods, and articles can alternatively comprise, consist of, or consist essentially of, any appropriate materials, steps, or components herein disclosed. The compositions, methods, and articles can additionally, or alternatively, be formulated so as to be devoid, or substantially free, of any materials (or species), steps, or components, that are otherwise not necessary to the achievement of the function or objectives of the compositions, methods, and articles.

[0115] All ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other. “Combinations” is inclusive of blends, mixtures, alloys, reaction products, and the like. The terms “first,” “second,” and the like, do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The terms “a” and “an” and “the” do not denote a limitation of quantity, and are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. “Or” means “and/or” unless clearly stated otherwise. Reference throughout the specification to “an aspect” means that a particular element described in connection with the aspect is included in at least one aspect described herein, and may or may not be present in other aspects. The term “combination thereof’ as used herein includes one or more of the listed elements, and is open, allowing the presence of one or more like elements not named. In addition, it is to be understood that the described elements may be combined in any suitable manner in the various aspects.

[0116] Unless specified to the contrary herein, all test standards are the most recent standard in effect as of the filing date of this application, or, if priority is claimed, the filing date of the earliest priority application in which the test standard appears.

[0117] Unless defined otherwise, technical and scientific terms used herein have the same meaning as is commonly understood by one of skill in the art to which this application belongs. All cited patents, patent applications, and other references are incorporated herein by reference in their entirety. However, if a term in the present application contradicts or conflicts with a term in the incorporated reference, the term from the present application takes precedence over the conflicting term from the incorporated reference.

[0118] Compounds are described using standard nomenclature. For example, any position not substituted by any indicated group is understood to have its valency filled by a bond as indicated, or a hydrogen atom. A dash

that is not between two letters or symbols is used to indicate a point of attachment for a substituent. For example, -CHO is attached through carbon of the carbonyl group.

[0119] As used herein, the term “hydrocarbyl”, whether used by itself, or as a prefix, suffix, or fragment of another term, refers to a residue that contains only carbon and hydrogen. The residue can be aliphatic or aromatic, straight-chain, cyclic, bicyclic, branched, saturated, or unsaturated. It can also contain combinations of aliphatic, aromatic, straight chain, cyclic, bicyclic, branched, saturated, and unsaturated hydrocarbon moieties. However, when the hydrocarbyl residue is described as substituted, it may, optionally, contain heteroatoms over and above the carbon and hydrogen members of the substituent residue. Thus, when specifically described as substituted, the hydrocarbyl residue can also contain one or more carbonyl groups, amino groups, hydroxyl groups, or the like, or it can contain heteroatoms within the backbone of the hydrocarbyl residue. The term "alkyl" means a branched or straight chain, saturated aliphatic hydrocarbon group, e.g., methyl, ethyl, n-propyl, i-propyl, n-butyl, s-butyl, t-butyl, n- pentyl, s-pentyl, and n- and s-hexyl. “Alkoxy” means an alkyl group that is linked via an oxygen (i.e., alkyl-O-), for example methoxy, ethoxy, and sec -butyloxy groups. "Alkylene" means a straight or branched chain, saturated, divalent aliphatic hydrocarbon group (e.g., methylene (-CH2-) or, propylene (-(CH2)3-)). “Cycloalkylene” means a divalent cyclic alkylene group, -C_nH2n-x, wherein x is the number of hydrogens replaced by cyclization(s). The prefix 1 "halo" means a group or compound including one more of a fluoro, chloro, bromo, or iodo substituent. A combination of different halo atoms (e.g., bromo and fluoro), or only chloro atoms can be present. The prefix “hetero” means that the compound or group includes at least one ring member that is a heteroatom (e.g., 1, 2, or 3 heteroatom(s)), wherein the heteroatom(s) is each independently N, O, S, Si, or P. “Substituted” means that the compound or group is substituted with at least one (e.g., 1, 2, 3, or 4) substituents that can each independently be a C1-9 alkoxy, a C1-9 haloalkoxy, a nitro (-NO2), a cyano (-CN), a C1-6 alkyl sulfonyl (-S(=O)2-alkyl), a C6-12 aryl sulfonyl (-S(=O)2-aryl), a thiol (-SH), a thiocyano (-SCN), a tosyl (CH3C6H4SO2-), a C3-12 cycloalkyl, a C2-12 alkenyl, a C5-12 cycloalkenyl, a Ce-12 aryl, a C7-13 arylalkylene, a C4-12 heterocycloalkyl, and a C3-12 heteroaryl instead of hydrogen, provided that the substituted atom’s normal valence is not exceeded. The number of carbon atoms indicated in a group is exclusive of any substituents. For example -CH2CH2CN is a C2 alkyl group substituted with a nitrile.

[0120] While particular embodiments have been described, alternatives, modifications, variations, improvements, and substantial equivalents that are or may be presently unforeseen may arise to applicants or others skilled in the art. Accordingly, the appended claims as filed and as they may be amended are intended to embrace all such alternatives, modifications variations, improvements, and substantial equivalents.

Claims

1 . A lubricant additive composition comprising:

0.1 to 5 weight percent of a particle composition having an average particle size of less than 1 micrometer;

10 to 94.3 weight percent of a first polyhydroxy ester;

5 to 30 weight percent of a second polyhydroxy ester;

0.5 to 5 weight percent of a borate ester; and

0.1 to 5 weight percent of a dispersant; wherein weight percent of each component is based on the total weight of the composition.

2. The lubricant additive composition of claim 1, wherein the particle composition comprises boric acid, boric oxide, or a combination thereof.

3. The lubricant additive composition of claim 1 , wherein the particle composition comprises lanthanum oxide.

4. The lubricant additive composition of claim 1 , wherein the particle composition has an average particle size of 50-500 nanometers.

5. The lubricant additive composition of claim 1, wherein the first and second polyhydroxy ester are each independently derived from a C3-12 aliphatic polyol comprising 2 to 8 hydroxyl groups and a C5-36 aliphatic monocarboxylic acid, and wherein the first and second polyhydroxy ester are not the same.

6. The lubricant additive composition of claim 1 , wherein the first and second polyhydroxy ester are each independently derived from a polyol comprising neopentyl glycol, 2,2-dimethyl-3-hydroxypropyl-2,2-dimethyl-3- hydroxypropionate, 2,2,4-trimethyl-l,5-pentanediol, trimethylolethane, trimethylolpropane, glycerol, pentaerythritol, dipentaerythritol, tripentaerythritol; and a C12-36 aliphatic monocarboxylic acid.

7. The lubricant additive composition of claim 1, wherein the first polyhydroxy ester comprises trimethylolpropane trioleate and the second polyhydroxy ester comprises a pentaerythritol ester of lanolin acid.

8. The lubricant additive composition of claim 1, wherein the borate ester is a borated monoglyceride ethoxylated amide.

9. The lubricant additive composition of claim 1 , wherein the dispersant comprises a polymeric polyamine dispersant.

10. The lubricant additive composition of claim 1, wherein the dispersant comprises a polyisobutylene succinic acid or anhydride and a polyamine, wherein the dispersant is treated with maleic anhydride and boric acid.

11. The lubricant additive composition of claim 10, wherein the polyisobutylene succinic acid or anhydride has a molecular weight of 1,000 to 2,500 grams per mole.

12. The lubricant additive composition of claim 1, comprising

0.5 to 1.5 weight percent of the particle composition;

70 to 80 weight percent of a first polyhydroxy ester;

15 to 25 weight percent of a second polyhydroxy ester;

1 to 3 weight percent of the borate ester; and

0.1 to 1 weight percent of the dispersant.

13. The lubricant additive composition of claim 12, wherein the particle composition comprises boric acid, boric oxide, or a combination thereof; the first polyhydroxy ester comprises trimethylolpropane trioleate; the second polyhydroxy ester comprises a pentaerythritol ester of lanolin acid; the borate ester comprises a borated monoglyceride ethoxylated amide; and the dispersant comprises a polyisobutylene succinic acid or anhydride and a polyamine, wherein the dispersant is treated with maleic anhydride and boric acid.

14. The lubricant additive composition of claim 1, wherein the composition is free of sulfur, phosphorus, metal, or a combination thereof.

15. A lubricant composition comprising the lubricant additive composition of claim 1.

16. The lubricant composition of claim 15, comprising a major proportion of a base oil and a minor proportion of the lubricant additive composition.

17. The lubricant composition of claim 16, comprising 55 to 99.99 weight percent of the base oil and 0.01 to 45 weight percent of the lubricant additive composition, wherein weight percent is based on the total weight of the lubricant composition.

18. A method for the manufacture of the lubricant additive composition of claim 1, the method comprising: combining the components of the composition under conditions effective to provide the lubricant additive composition.

19. The method of claim 18, wherein combining the components of the composition comprises combining the particle composition, the first polyhydroxy ester, the second polyhydroxy ester in liquid form, the borate ester, and the dispersant to provide a mixture; and mixing the mixture under high shear to provide the lubricant additive composition.

20. The method of claim 18, wherein combining the components comprises combining the particle composition and the first polyhydroxy ester to provide a first mixture; combining the first mixture, the second polyhydroxy ester in liquid form, the borate ester, and the dispersant to provide a second mixture.

21. The method of claim 18, further comprising adding an additional amount of the first polyhydroxy ester to provide the lubricant additive composition.

22. The method of claim 18, wherein conditions effective to provide the lubricant additive composition comprise milling, preferably for 1 to 24 hours at a temperature of 75 to 120°C.

23. The method of claim 18, further comprising heating the second polyhydroxy ester to a temperature greater than the melting point of the second polyhydroxy ester to provide the second polyhydroxy ester as a liquid.

24. The method of claim 18, wherein conditions effective to provide the lubricant additive composition comprise homogenizing the lubricant additive composition under high shear.

25. The method of claim 18, wherein conditions effective to provide the lubricant additive composition comprise ultrasonically mixing the lubricant additive composition.

26. A method for the manufacture of the lubricant composition of claim 15, the method comprising: combining a base grease with the lubricant additive composition of claim 1.

27. A method for wear protection of a surface, the method comprising: applying the lubricant composition of claim 15 to at least a portion of a surface.