EP4685215A1

EP4685215A1 - A lubricant composition including an ester amine

Info

Publication number: EP4685215A1
Application number: EP25191081.6A
Authority: EP
Inventors: Alina FILIN; John Thomas Dixon; Ezio AMERIO
Original assignee: Nouryon Chemicals International BV
Current assignee: Nouryon Chemicals International BV
Priority date: 2024-07-24
Filing date: 2025-07-22
Publication date: 2026-01-28
Also published as: CN121406392A

Abstract

A lubricant composition that is ashless includes an oil of lubricating viscosity, an ester amine that is the reaction product of a diacid and/or an anhydride, and an ethoxylated amine; wherein the ester amine is present in an amount of from about 0.05 to about 1 wt% actives, based on a total weight of the lubricant composition.

Description

TECHNICAL FIELD

The present disclosure generally relates to a lubricant composition that is ashless. More specifically, the lubricant composition includes an oil of lubricating viscosity and a particular ester amine.

BACKGROUND

Lubricants can be utilized in various industries for various applications, e.g. in machinery, automotive engines, and many other mechanical systems to facilitate a smooth operation and increase longevity of mechanical parts, by reducing friction, wear, and heat between moving surfaces of the mechanical parts. The effectiveness of a lubricant can often be attributed to its active components, e.g. friction modifiers.
Many conventional friction modifiers exhibit good friction modification performance but only in specific conditions, such as in a particular temperature range, load, and speed. For example, at high temperatures, thermal degradation of these friction modifiers can occur, which may lead to the formation of unwanted by-products, and thus, decrease the effectiveness in friction modification of the lubricant.
Furthermore, various conventional friction modifiers include rare metals that may be expensive to produce and may not be sustainable considering the increasing environmental and natural resource management standards.
Bio-lubricants including friction modifiers derived from natural and renewable resources can be desirable alternatives due to their low cost, high abundance and low toxicity. However, bio-lubricants can experience performance shortcomings. Accordingly, there is an opportunity for improvement.

BRIEF SUMMARY

This disclosure provides a lubricating composition that is ashless including an oil of lubricating viscosity; and an ester amine that is the reaction product of a diacid and an ethoxylated amine, wherein the ethoxylated amine has the structure: wherein R¹ is a C10-C24 alkyl or alkenyl group; wherein each x is independently from about 1 to about 10; and wherein the ester amine is present in an amount of from about 0.05 to about 1 wt% actives, based on a total weight of the lubricant composition.
The disclosure also provides a lubricating composition that is ashless including an oil of lubricating viscosity; and an ester amine that is the reaction product of adipic acid and an ethoxylated amine.
The disclosure additionally provides a lubricating composition that is ashless including an oil of lubricating viscosity; and an ester amine that is the reaction product of succinic acid and an ethoxylated amine.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will hereinafter be described in conjunction with the following figures, wherein

FIG. 1A is a collection of Stribeck curves, also described as line plots, of coefficient of friction versus entrainment speed, which can be categorized into three regimes including boundary, mixed, and an elastohydrodynamic lubrication (EHD), of the lubricant composition (Example 1) and a comparative composition (CE 4) of the Example, performed at a temperature of 40 °C;
FIG. 1B is a collection of Stribeck curves of the lubricant composition (Example 1) and a comparative composition (CE 4) of the Example, performed at a temperature of 80 °C;
FIG. 1C is a collection of Stribeck curves of the lubricant composition (Example 1) and a comparative composition (CE 4) of the Example, performed at a temperature of 120 °C;
FIG. 2 is a collection of Stribeck curves of Examples 1 and 3, and CE 4 of the Example, performed at 120 °C.

DETAILED DESCRIPTION

The following detailed description is merely exemplary in nature and is not intended to limit the current composition. Furthermore, there is no intention to be bound by any theory presented in the preceding background or the following detailed description.
Embodiments of the present disclosure are generally directed to chemical compounds, e.g. ester amines, ethoxylated amines, diacids, anhydrides, etc., compositions including the same, and methods for forming the same. For the sake of brevity, conventional techniques related to making such chemical compounds and compositions may not be described in detail herein. Moreover, the various tasks and process steps described herein may be incorporated into a more comprehensive procedure or process having additional steps or functionality not described in detail herein. In particular, various steps in the manufacture of chemical compounds and associated compositions are well-known and so, in the interest of brevity, many conventional steps will only be described briefly herein or will be omitted entirely without providing the well-known process details.
In this disclosure, the terminology "about" can describe values ± 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10%, in various embodiments. Moreover, it is contemplated that, in various non-limiting embodiments, it is to be appreciated that all numerical values as provided herein, save for the actual examples, are approximate values with endpoints or particular values intended to be read as "about" or "approximately" the value as recited. It is also contemplated that all isomers and chiral options for each compound described herein are hereby expressly contemplated for use herein in various non-limiting embodiments.
Throughout this disclosure, the terminology percent "actives" is well recognized in the art and means the percent amount of active or actual compound or molecule present as compared to, for example, a total weight of a diluted solution of a solvent and such a compound. Some compounds, such as a solvent, are not described relative to a percent actives because it is well known to be approximately 100% actives. Any one or more of the values described herein may be alternatively described as percent actives as would be understood by the skilled person.
In various embodiments, the terminology "free of" describes embodiments that include less than about 5, 4, 3, 2, 1, 0.5, or 0.1, weight percent (or weight percent actives) of the compound or element at issue using an appropriate weight basis as would be understood by one of skill in the art. In other embodiments, the terminology "free of" describes embodiments that have zero weight percent of the compound or element at issue.
The terminology "consists essentially of" may describe various non-limiting embodiments that are free of one or more optional compounds described herein and/or free of one or more chemical compounds, additives, solvents, etc.
It is to be understood that the subscripts of chemical compounds that are polymeric, e.g. ester amine, ethoxylated amine, etc., are typically described as average values because the synthesis of chemical compounds typically produces a distribution of various individual molecules.
The chemical compounds and compositions disclosed herein may suitably comprise, consist of, or consist essentially of the components, elements, and process delineations described herein. The embodiments illustratively disclosed herein suitably may be practiced in the absence of any element which is not specifically disclosed herein.

Lubricant Composition:

This disclosure provides a lubricating composition that is ashless including an oil of lubricating viscosity, and an ester amine that is the reaction product of a diacid and an ethoxylated amine. The lubricant composition may be described herein simply as "the composition". The lubricant composition may be further described as, or may be used as, a lubricant, a lubricator, an engine oil, a motor oil, a transmission fluid, an EV fluid, grease, etc. The lubricant composition may be used to reduce friction and wear in a mechanical system, e.g. a combustion engine, an electric motor, a gearbox, bearings, hydraulic systems, etc.
The composition is ashless. The terminology "ashless" may be used to describe a minimal presence of visible inorganic residues (ash), which may include a metal, when the composition is burned, which can negatively affect the performance of mechanical parts. In various embodiments, the composition is free of visible inorganic residues, or ashless. In other embodiments, the composition exhibits minimal visible inorganic residues, which may also be described as ashless.
The composition of this disclosure may also exhibit excellent wear performance, provide good wear protection at comparatively low treat rates, exhibit good oil solubility (e.g. high carbon content), have a comparatively low phosphorous content, and/or low sulfur content, as compared to comparative compositions. The composition may additionally exhibit both good wear performance and low friction coefficients simultaneously, have customizable TBN values, detergency properties, and/or friction modification properties. Moreover, the composition is ashless (low metal content), and can be halogen-, phosphor- and sulfur-free, which can be beneficial in several applications e.g. engine oils, transmission fluids for EVs and hydraulic fluids, that exhibit improved wear performance when compared to compositions that include, for example, an industry standard, e.g. zinc dihydrocarbyl dithiophosphate (ZDDP), tallow amide, and/or molybdenum dithiocarbamate (MoDTC), that exhibit excellent wear performance at comparatively low treat rates, that exhibit both low friction coefficients at various temperatures ( which can be desirable for EV fluids) and low wear performance (contrary to ZDDPs), that exhibit variable friction performance at the same low wear performance (which can be desirable for transmission fluids).
In various other embodiments, the lubricant composition is combined with an industry standard, including but not limited to ZDDP, tallow amide, and/or MoDTC, such that including one or more of the industry standards further provides synergistic effect to the lubricant composition, allowing for good wear performance and low friction coefficients.

Oil of Lubricating Viscosity

The lubricant composition includes an oil of lubricating viscosity. The oil of lubricating viscosity, i.e., an oil exhibiting a viscosity suitable for use in lubricating applications such as those described here, may be alternatively described as a base stock, a base oil, or simply as an oil. This oil is typically the primary liquid constituent of the composition and may be any known in the art. In one embodiment, the oil is described as a base oil and is chosen from natural (vegetable, animal or mineral), synthetic lubricating oils and combinations thereof. The type of oil is not particularly limited and may be any type of oil of lubricating viscosity known in the art.
In various embodiments, the oil is a Group I, II, III, IV, or V oil as defined in the American Petroleum Institute (API) publication "Engine Oil Licensing and Certification System", Industry Services Department, Fourteenth Edition, December 1996, Addendum 1, December 1998. For example, the oil may include less than about 90 percent saturates and/or greater than about 0.03 percent sulfur and has a viscosity index greater than or equal to about 80 and less than about 120.
In the aforementioned descriptions, saturates may be measured using ASTM D 2007, viscosity index may be determined using ASTM D 2270, sulfur may be measured using ASTM D 2622, ASTM D 4294, ASTM D 4927, ASTM D 3120, or combinations thereof.
In various embodiments, the oil includes greater than or equal to about 10, about 15, about 20, about 25, about 30, about 35, about 40, about 45, about 50, about 55, about 60, about 65, about 70, about 75, about 80, about 85, about 90, or about 95 wt %, of a Group I, II, III, IV, or V oil, based on the total weight of the oil itself. In various non-limiting embodiments, all values and ranges of values, both whole and fractional, including and between those described above, are hereby expressly contemplated for use herein.
In other embodiments, the oil is or includes a natural oil which may be chosen from animal and vegetable oils (e.g. castor and lard oil), liquid petroleum oils and hydro refined, solvent-treated mineral lubricating oils of the paraffinic, naphthenic and mixed paraffinic-naphthenic types, and combinations thereof. Alternatively, the oil may be derived from coal or shale.
In other embodiments, the oil is or includes a synthetic lubricating oil which may be chosen from hydrocarbon oils such as polymerized and interpolymerized olefins (e.g. polybutylenes, polypropylenes, propylene-isobutylene copolymers, chlorinated polybutylenes, poly(1-hexenes), poly(1-octenes), poly(1-decenes)); alkylbenzenes (e.g. dodecylbenzenes, tetradecylbenzenes, dinonylbenzenes, di(2-ethylhexyl)benzenes); polyphenols (e.g. biphenyls, terphenyls, alkylated polyphenols); and alkylated diphenyl ethers and alkylated diphenyl sulfides and the derivatives, analogues and homologues thereof, and combinations thereof.
In other embodiments, the oil is or includes an ester of a dicarboxylic acid (e.g. phthalic acid, succinic acid, alkyl succinic acids and alkenyl succinic acids, maleic acid, azelaic acid, suberic acid, sebasic acid, fumaric acid, adipic acid, linoleic acid dimer, malonic acid, alkylmalonic acids, alkenyl malonic acids) with a variety of alcohols (e.g. butyl alcohol, hexyl alcohol, dodecyl alcohol, 2-ethylhexyl alcohol, ethylene glycol, diethylene glycol monoether, propylene glycol), and combinations thereof. Specific 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, the 2-ethylhexyl diester of linoleic acid dimer, and the complex ester formed by reacting one mole of sebacic acid with two moles of tetraethylene glycol and two moles of 2-ethylhexanoic acid. Other esters include those made from C₅ to C₁₂ monocarboxylic acids and polyols, and polyol ethers such as neopentyl glycol, trimethylolpropane, pentaerythritol, dipentaerythritol and tripentaerythritol. Still others include esters made from mono carboxylic acids and monoalcohols e.g. methanol, ethanol, etc. Methyl esters often have low viscosities. These monoesters can also be based on alkoxylated alcohols wherein alkoxylate groups are ethylene oxide and/or propylene oxide. Other examples include polyalkylene glycol (PAG) derived oil. These polyalkylene glycols can be used as is or etherified by reaction with alcohols or esterified by reaction with carboxylic acids, particularly mono-acids.
In other embodiments, the oil is or includes an unrefined, refined or re-refined oil. Unrefined oils are those obtained directly from a natural or synthetic source without further purification treatment. For example, a shale oil obtained directly from retorting operations, a petroleum oil obtained directly from distillation or ester oil obtained directly from an esterification process and used without further treatment would be unrefined oil. 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. Many such purification techniques, such as distillation, solvent extraction, acid or base extraction, filtration and percolation are known to those skilled in the art. Re-refined oils are obtained by processes similar to those used to obtain refined oils applied to refined oils which have been already used in service. Such re-refined oils are also known as reclaimed or reprocessed oils and often are additionally processed by techniques for approval of spent additive and oil breakdown products.
In other embodiments, the oil is or includes a gas-to-liquid ("GTL") oil, i.e. the oil may be an oil derived from Fischer-Tropsch synthesized hydrocarbons made from synthesis gas containing H₂ and CO using a Fischer-Tropsch catalyst. These hydrocarbons typically require further processing in order to be useful as an oil. For example, they may, by methods known in the art, be hydroisomerized; hydrocracked and hydroisomerized; dewaxed; or hydroisomerized and dewaxed.
In other embodiments, the volatility of the oil, as measured by the NOACK test (ASTM D5880), is less than or equal to about 16%, about 13.5%, about 12%, about 10%, or about 8%. Typically, the viscosity index (VI) of the oil is at least about 95, about 110, about 120, or about 125, or from about 130 to about 140, measured according to ASTM D5880. In various non-limiting embodiments, all values and ranges of values, both whole and fractional, including and between those described above, are hereby expressly contemplated for use herein.
In various embodiments, the oil is present in an amount of greater than about 55, about 60, about 65, about 70, about 75, about 80, about 85, or about 90, wt %, based on the total weight of the composition. In other embodiments, the oil is present in an amount of less than about 99, about 98, about 97, about 96, about 95, about 94, about 93, about 92, about 91, or about 90, wt%, based on a total weight of the composition. In still other embodiments, the oil may be present in an amount to balance the amount of the ester amine (e.g. as described below), such that the total weight is about 100 wt%. Alternatively, the amount of the oil may be such that the amount of the oil, plus the amount of the ester amine, plus the amount of any one or more additives described herein, is about 100 wt%. In various non-limiting embodiments, all values and ranges of values, both whole and fractional, including and between those described above, are hereby expressly contemplated for use herein.

Ester Amine

The lubricant composition also includes the ester amine. The ester amine may also be described as a polymeric ester amine and may be used in the composition as a friction modifier. The ester amine is a reaction product of a diacid and/or an anhydride and an ethoxylated amine, wherein the ethoxylated amine has the structure: wherein R¹ is a C10-C24 alkyl or alkenyl group; and each x is independently from about 1 to about 10.
Referring to R¹ in structure (I), R¹ is a C10-C24 alkyl or alkenyl group. The C10-C24 alkyl or alkenyl group may be linear or branched having 10 to 24 carbon atoms. The group may be saturated or unsaturated. In various embodiments, the group has 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23 or 24 carbon atoms. In other embodiments, the group has 10 to 24, 11 to 23, 12 to 22, 13 to 21, 14 to 20, 15 to 19, 16 to 18, 15 to 17, 15 to 16, 14 to 18, or 15 to 20 carbon atoms. In various non-limiting embodiments, all values and ranges of values, both whole and fractional, including and between those described above, are hereby expressly contemplated for use herein.
The C10-C24 alkyl or alkenyl group may be synthetic or naturally derived. In various embodiments, R¹ is synthetically derived. The terminology "synthetic" indicates that the group is artificially formed through chemical synthesis, typically starting from a simple organic molecule, e.g. a shorter alkyl or alkenyl molecule, e.g. C1-C9, to form more complex structures through one or more chemical reactions, e.g. Wurtz reaction, Corey-House synthesis, Friedel-Crafts alkylation, Wittig Reaction, Hydroboration-Oxidation, Catalytic Hydrogenation, etc.
In various embodiments, R¹ is naturally derived. The terminology "naturally derived" indicates that R¹ is derived from a natural source such as a plant or animal, e.g. from animal fat. Therefore, it is contemplated that the C10-C24 group may be alternatively described as a naturally sourced group or as a group derived from a natural source. The group may also be described as a plant-based group or as an animal fat-based group. Non-limiting examples of naturally derived C10-C24 groups include tallowyl groups, oleyl groups, cocoyl groups, plant or animal esters, e.g. palm oil, rape seed oil, palm kernel oil, coconut oil, babassu oil, soybean oil, castor oil, tallow, tall oil, whale or fish oils, grease, lard, and mixtures thereof. Accordingly, suitably C10-C24 groups include cocoyl, oleyl, tallowyl, tallyl, soyayl, rapeseedyl, palmyl groups and the like. In other embodiments, the naturally derived C10-C24 group is chosen from groups such as C10 - Capric, C12 - Lauric, C14 - Myristic, C15 - Pentadecylic, C16 - Palmitic, C17 - Margaric, C18 - Stearic, C14 - Myristoleic, C16' - Palmitoleic, C18' - Oleic, C18"-Linoleic, C20 - Arachidic, C20 - Docosanoic, C24 - Tetracosanoic, and combinations thereof. In various embodiments, the ethoxylated amine is tallow amine ethoxylate.
Also referring back, each subscript x describes an average number of repeating ethylene oxide (C₂H₄O) units in structure (I). Accordingly, each x may be a whole or a fractional number. Typically, each x is independently from about 1 to about 10, about 2 to about 8, about 3 to about 7, about 4 to about 6, about 4 to about 5, or about 1 to about 3. In various embodiments, each x is independently about 1, about 2, about 3, about 4, about 5, about 6, about 7, about 8, about 9, or about 10. In various embodiments, the ethoxylated amine has the structure (I) that includes subscripts x that are the same. In other embodiments, the ethoxylated amine has the structure (I) that includes subscripts x that are different from each other. In various non-limiting embodiments, all values and ranges of values, both whole and fractional, including and between those described above, are hereby expressly contemplated for use herein.
As first described above, the ester amine is a reaction product of a diacid and/or an anhydride and an ethoxylated amine. Referring to the diacid, the terminology diacid, also known as dicarboxylic acid, describes an organic compound that includes two carboxyl functional groups -COOH in its molecular structure. The diacid can vary in carbon chain length, positioning of the carboxyl groups, and degree of saturation or unsaturation.
In various embodiments, the diacid has the chemical structure HOOC-R'-COOH, wherein R' is an alkyl group of various lengths, and typically has 1 to 5 carbon atoms. In other embodiments, R' has 1, 2, 3, 4, or 5 carbon atoms. In yet other embodiments, R' has from 1 to 5 carbon atoms, 1 to 2 carbon atoms, 1 to 3 carbon atoms, 1 to 4 carbon atoms, 2 to 3 carbon atoms, 2 to 4 carbon atoms, 2 to 5 carbon atoms, or 4 to 5 carbon atoms. In various non-limiting embodiments, all values and ranges of values, both whole and fractional, including and between those described above, are hereby expressly contemplated for use herein. In various other embodiments, the diacid has the chemical structure -(COOH)₂. Non-limiting examples of diacids include adipic acid, succinic acid, oxalic acid, malonic acid, glutaric acid, pimelic acid, etc., and combinations thereof.
The ester amine may alternatively be or include the product of the ethoxylated amine and the anhydride. The terminology "anhydride" describes an organic compound that has the structure R^a-(C=O)-O-(C=O)-R^b. R^a and R^b may independently be an alkyl group of various lengths of typically 1 to 5 carbon atoms. In various embodiments, R^a and/or R^b independently have 1, 2, 3, 4, or 5 carbon atoms. In yet other embodiments, R^a and/or R^b independently have from 1 to 5 carbon atoms, 1 to 2 carbon atoms, 1 to 3 carbon atoms, 1 to 4 carbon atoms, 2 to 3 carbon atoms, 2 to 4 carbon atoms, 2 to 5 carbon atoms, or 4 to 5 carbon atoms. In various non-limiting embodiments, all values and ranges of values, both whole and fractional, including and between those described above, are hereby expressly contemplated for use herein. In various embodiments, R^a and R^b may be connected in a ring system. Non-limiting examples of anhydrides include acetic anhydride, succinic anhydride, propanoic anhydride, ethanoic propanoic anhydride, etc. In one embodiment, the anhydride is succinic anhydride.
In various embodiments, the ester amine is the product of the ethoxylated amine and only one diacid. In other embodiments, the ester amine is product of the ethoxylated amine and two or more diacids. In various embodiments, the ester amine is the product of the ethoxylated amine and only one anhydride. In other embodiments, the ester amine is product of the ethoxylated amine and two or more anhydrides. In yet other embodiments, the ester amine is product of the ethoxylated amine, the anhydride, and the diacid.
Furthermore, the diacid and/or the anhydride and the ethoxylated amine may be reacted in various weight ratios, which may be varied according to different needs and applications of the lubricant composition, or the identity of the diacid, the anhydride and the ethoxylated amine. For example, the weight ratio of the diacid and/or the anhydride and the ethoxylated amine may be from about 5:95 to about 30:70. In various embodiments, the weight ratio is about 5:95, about 6:94, about 7:93, about 8:92, about 9:91, about 10:90, about 11:89, about 12:88, about 13:87, about 14:86, about 15:85, about 16:84, about 17:83, about 18:82, about 19:81, about 20:80, about 21:79, about 22:78, about 23:77, about 24:76, about 25:75, about 26:74, about 27:73, about 28:72, about 29:71, or about 30:70. In various non-limiting embodiments, all values and ranges of values, both whole and fractional, including and between those described above, are hereby expressly contemplated for use herein.
Depending on the identity of ethoxylated amine, the diacid, and/or the anhydride, the ester amine may have a repeating unit chosen from the structures: and combinations thereof;

wherein each R¹, R², and R³ is independently a C10-C24 alkyl or alkenyl group;
wherein each R' is independently a C1-C5 alkyl group; and
wherein each x and y is independently from about 1 to about 10.

Referring to R¹, R², and R³, each R¹, R², and R³ may be independently a C10-C24 alkyl or alkenyl group. Each of R¹, R², and R³ may be derived from the same or different ethoxylated amines, and accordingly may be the same as, or different from, one another. Additionally, R¹, R², and R³ in structures (II), (III) and (IV) may be the same as, or different from R¹ in structure (I), which may be linear or branched having 10 to 24 carbon atoms. As first described above, C10-C24 alkyl or alkenyl group may be saturated or unsaturated. In various embodiments, the group has 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23 or 24 carbon atoms. In other embodiments, the group has 10 to 24, 11 to 23, 12 to 22, 13 to 21, 14 to 20, 15 to 19, 16 to 18, 15 to 17, 15 to 16, 14 to 18, 16 to 18 or 15 to 20 carbon atoms. In various non-limiting embodiments, all values and ranges of values, both whole and fractional, including and between those described above, are hereby expressly contemplated for use herein.
Referring to R', each R' may be independently a C1-C5 alkyl group. R' in structure (III) may be the same as, or different from, R' in structure (IV). Moreover, R' in structures (III) and (IV) may be the same as, or different from R' in the structure of the diacid as described above. In various embodiments, each R' is independently an alkyl group of various lengths, and typically has 1 to 5 carbon atoms. In other embodiments, each R' independently has 1, 2, 3, 4, or 5 carbon atoms. In yet other embodiments, each R' independently has from 1 to 5 carbon atoms, 1 to 2 carbon atoms, 1 to 3 carbon atoms, 1 to 4 carbon atoms, 2 to 3 carbon atoms, 2 to 4 carbon atoms, 2 to 5 carbon atoms, or 4 to 5 carbon atoms. In various non-limiting embodiments, all values and ranges of values, both whole and fractional, including and between those described above, are hereby expressly contemplated for use herein.
Each x and y is independently from about 1 to about 10. Each x and y may be the same as, or different from one another. In various embodiments, each x and y is independently from about 1 to about 10, about 2 to about 8, about 3 to about 7, about 4 to about 6, about 4 to about 5, about 1 to about 6, about or about 1 to about 3. In other embodiments, each x and y is independently 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10. In various non-limiting embodiments, all values and ranges of values, both whole and fractional, including and between those described above, are hereby expressly contemplated for use herein.
In various embodiments, the ester amine has structure (II) as the only repeating unit. In other embodiments, the ester amine has structure (III) as the only repeating unit. In other embodiments, the ester amine has structure (IV) as the only repeating unit. In various other embodiments, the ester amine has a combination of structures (II), (III), and (IV) as the repeating units.
In various embodiments, only one ester amine is included in the lubricant composition. In various other embodiments, two or more ester amines are included in the lubricant composition.
The repeating unit(s) of the ester amine may be repeated various number of times, so long as the weight average molecular weight (M_w) of the ester amine is from about 1000 to about 15,000 Da. In various embodiments, the weight average M_w of the ester amine is from about 1000 to about 15,000 Da. In other embodiments, the weight average M_w of the ester amine is from about 1000 to about 5000 Da, about 1100 to about 4900 Da, about 1200 to about 4800 Da, about 1300 to about 4700 Da, about 1400 to about 4600 Da, about 1500 to about 4500 Da, about 1600 to about 4400 Da, about 1700 to about 4300 Da, about 1800 to about 4200 Da, about 1900 to about 4100 Da, about 2000 to about 4000 Da, about 2100 to about 3900 Da, about 2200 to about 3800 Da, about 2300 to about 3700 Da, about 2400 to about 3600 Da, about 2500 to about 3500 Da, about 2600 to about 3400 Da, about 2700 to about 3300 Da, about 2800 to about 3200 Da, about 2900 to about 3100 Da, or about 2900 to about 3000 Da. In yet other embodiments, the weight average M_w of the ester amine is from about 5000 to about 15,000 Da, about 6000 to about 14,000 Da, about 7000 to about 13,000 Da, about 8000 to about 12,000 Da, about 9000 to about 11,000 Da, about 10,000 to about 11,000 Da. In various non-limiting embodiments, all values and ranges of values, both whole and fractional, including and between those described above, are hereby expressly contemplated for use herein.
The ester amine may be present in the lubricant composition in various amounts, typically from about 0.05 to about 1 wt% actives, based on a total weight of the lubricant composition. In various embodiments, the ester amine is present in an amount of from about 0.05 to about 1 wt% actives, about 0.1 to about 0.95 wt% actives, about 0.15 to about 0.9 wt% actives, about 0.2 to about 0.85 wt% actives, about 0.25 to about 0.8 wt% actives, about 0.3 to about 0.75 wt% actives, about 0.35 to about 0.7 wt% actives, about 0.4 to about 0.65 wt% actives, about 0.45 to about 0.6 wt% actives, about 0.5 to about 0.55 wt% active, based on a total weight of the lubricant composition. In other embodiments, the ester amine is present in an amount of from about 0.2 to about 4 wt% actives, based on a total weight of the lubricant composition. In various non-limiting embodiments, all values and ranges of values, both whole and fractional, including and between those described above, are hereby expressly contemplated for use herein.

Additives

The lubricant composition may include, or be free of, one or more additives that is not the ester amine described above. For example, the composition may include, or be free of, one or more additives such as, but not limited to, metal deactivators, viscosity modifiers, detergents, friction modifiers, antiwear agents, corrosion inhibitors, dispersants, dispersant viscosity modifiers, extreme pressure agents, antioxidants, foam inhibitors, demulsifiers, pour point depressants, seal swelling agents, and any combination or mixture thereof.
More specifically, the composition may include, or be free of, MoDTC, which may be used as an additional friction modifier. In various embodiments, MoDTC is present in the composition in an amount of from about 0.1 to about 1 wt% actives, based on a total weight of the composition. In other embodiments, MoDTC is present in the composition in an amount of from about 0.2 to about 0.9 wt%, about 0.3 to about 0.8 wt%, about 0.4 to about 0.7 wt%, or about 0.5 to about 0.6 wt%, based on a total weight of the composition. In various non-limiting embodiments, all values and ranges of values, both whole and fractional, including and between those described above, are hereby expressly contemplated for use herein.
The composition may additionally and optionally include ZDDP, which may be used as an antiwear agent. In various embodiments, ZDDP is present in the composition in an amount of from about 0.1 to about 1 wt% actives, based on a total weight of the composition. In other embodiments, ZDDP is present in the composition in an amount of from about 0.2 to about 0.9 wt%, about 0.3 to about 0.8 wt%, about 0.4 to about 0.7 wt%, or about 0.5 to about 0.6 wt%, based on a total weight of the composition. In various non-limiting embodiments, all values and ranges of values, both whole and fractional, including and between those described above, are hereby expressly contemplated for use herein.
In various embodiments, the composition includes both MoDTC and ZDDP, in a total weight amount of from about 0.2 to about 2 wt%, about 0.3 to about 1.9 wt%, about 0.4 to about 1.8 wt%, about 0.5 to about 1.7 wt%, about 0.6 to about 1.6 wt%, 0.7 to about 1.5 wt%, about 0.8 to about 1.4 wt%, about 0.9 to about 1.3 wt%, about 1 to about 1.2 wt%, or about 1 to about 1.1 wt%, based on a total weight of the composition. In various non-limiting embodiments, all values and ranges of values, both whole and fractional, including and between those described above, are hereby expressly contemplated for use herein.
In various embodiments, the composition includes from about 0.1 to about 25 wt%, about 1 to about 5 wt%, about 1 to about 4 wt%, about 1 to about 3 wt%, about 1 to about 2 wt%, or about 2 to about 3 wt% of one or more additives, based on a total weight of the composition. In other embodiments, the composition includes from about 5 to about 25 wt%, about 6 to about 24 wt%, about 7 to about 23 wt%, about 8 to about 22 wt%, about 9 to about 21 wt%, about 10 to about 20 wt%, about 11 to about 19 wt%, about 12 to about 18 wt%, about 13 to about 17 wt%, about 14 to about 16 wt%, or about 14 to about 15 wt% of one or more additives, based on a total weight of the composition. In various non-limiting embodiments, all values and ranges of values, both whole and fractional, including and between those described above, are hereby expressly contemplated for use herein.

Physical Properties

The composition may exhibit a friction coefficient when utilized, which may be used to describe the ability of the composition to reduce friction between two or more surfaces, e.g. parts inside a combustion engine, an electric motor, a gearbox, between bearings, etc.
The friction coefficient of the composition may be evaluated in comparison to a comparative composition using a standardized method, e.g. ASTM D471, or by using a Mini Traction machine (MTM) test conducted at a sliding rolling ratio of about 50%, a load of about 20 N. The friction coefficient of the lubricant composition may alternatively be measured using various methods and/or instruments, e.g. using a pin-on-disk tribometer, using a four-ball tester, using a reciprocating tribometer, etc. A smaller friction coefficient may indicate an increase in lubrication performance, and thus, a more effective lubricant composition.
The friction coefficient may be measured at various temperatures, typically from about 40 to about 120 °C, e.g. about 40 °C, about 50 °C, about 60 °C, about 70 °C, about 80 °C, about 90 °C, about 100 °C, about 110 °C, or about 120 °C. Additionally, the friction coefficient may be measured at various entrainment speeds, e.g. about 1 to about 5000 mm/s, about 5 mm/s, about 50 mm/s, about 500 m/s, or about 5000 mm/s. Entrainment speeds may be categorized into lubrication regimes, which are known in art to include a boundary regime, a mixed regime, and a elastohydrodynamic lubrication (EHD) regime.
The friction coefficient at various conditions, e.g. various temperatures, entrainment speeds and/or lubrication regimes, may be visualized using a Stribeck curve, which may be known in the art as a plot of friction coefficient vs. entrainment speed. In various embodiments, the friction coefficient of the lubricant composition, measured using any of the aforementioned method and/or conditions, may be from about 0.001 to about 0.2. In other embodiments, the friction coefficient is from about 0.001 to about 0.01, about 0.002 to about 0.009, about 0.003 to about 0.008, about 0.004 to about 0.007, or about 0.005 to about 0.006. In other embodiments, the friction coefficient is from about 0.01 to about 0.1, about 0.02 to about 0.09, about 0.03 to about 0.08, about 0.04 to about 0.07, or about 0.05 to about 0.06. In yet other embodiments, the friction coefficient is from about 0.05 to about 0.2, about 0.1 to about 0.19, about 0.11 to about 0.18, about 0.12 to about 0.17, about 0.13 to about 0.16, or about 0.14 to about 0.15. In various non-limiting embodiments, all values and ranges of values, both whole and fractional, including and between those described above, are hereby expressly contemplated for use herein.
In various embodiments, the composition has a friction coefficient, as determined using an MTM test conducted at a sliding to rolling ratio of about 50%, a load of about 20 N, and at a temperature of from about 40 °C to about 120 °C, that is at least about 20, 25, 30, 35, 40, 45, or greater, % less than that of a comparative composition that includes MoDTC in a comparative amount to the ester amine but is free of the ester amine. In other words, when the composition of this disclosure is compared to a comparative composition that includes MoDTC, the instant composition has an improved coefficient of friction as described above. The terminology "in a comparative amount" means that the MoDTC is included in an amount that may or may not be the same weight or molar amount as the ester amine but is an amount that would be known to be comparative by the skilled person. In various embodiments, such an amount is about ± 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 mole or weight % different. It is contemplated that the above values may change depending on the content and type of oil (e.g. oil of lubricating viscosity) that is used for the test. In various non-limiting embodiments, all values and ranges of values, both whole and fractional, including and between those described above, are hereby expressly contemplated for use herein.
Likewise, in other embodiments, the composition has a friction coefficient, as determined using an MTM test conducted at a sliding to rolling ratio of about 50%, a load of about 20 N, and at a temperature of from about 40 °C to about 120 °C, that is at least about 20, 25, 30, 35, 40, 45, or greater, % less than that of a comparative composition that includes a tallow amide in a comparative amount to the ester amine but is free of the ester amine. In various non-limiting embodiments, all values and ranges of values, both whole and fractional, including and between those described above, are hereby expressly contemplated for use herein.
In various other embodiments, the composition has a friction coefficient, as determined using an MTM test conducted at a sliding to rolling ratio of about 50%, a load of about 20 N, and at a temperature of from about 40 °C to about 120 °C, that is at least about 20, 25, 30, 35, 40, 45, or greater, % less than that of a comparative composition that includes ZDDP in a comparative amount to the ester amine but is free of the ester amine. In various non-limiting embodiments, all values and ranges of values, both whole and fractional, including and between those described above, are hereby expressly contemplated for use herein.
Additionally, the composition may exhibit synergistic effect with another friction modifier and/or an antiwear agent, e.g. MoDTC, ZDDP, etc. such that the composition including the ester amine and MoDTC and/or ZDDP may exhibit a friction coefficient, as determined using an MTM test at various entrainment speed, e.g. 5 mm/s, 50 mm/s, 500 mm/s, 5000 mm/s, etc., that is at least about 20, 25, 30, 35, 40, 45, or greater, % less than that of a comparative composition that includes only MoDTC or only ZDDP in a comparative amount to the ester amine but is free of the ester amine, or at least about 5, 10, 20, 25, 30, 35, 40, 45, or greater, % less than that of the composition that includes only the ester amine but is free of the MoDTC or free of the ZDDP. In various non-limiting embodiments, all values and ranges of values, both whole and fractional, including and between those described above, are hereby expressly contemplated for use herein.
The composition may also exhibit an average wear scar, which can be used to describe the size of a wear mark left on a test article, such as a ball or a disk. The average wear scar may be measured using any standardized method known in the art, e.g. ASTM D4172, ASTM D975, in various conditions. In various embodiments, the average wear scar exhibited by the composition, measured using a high frequency reciprocating rig (HFRR) test, performed at about 120 °C, a frequency at about 20 Hz, and a load of about 1000 g, is from about 100 to about 300 microns, about 110 to about 290 microns, about 120 to about 270 microns, about 130 to about 260 microns, about 140 to about 250 microns, about 150 to about 240 microns, about 160 to about 230 microns, about 170 to about 220 microns, about 180 to about 210 microns, or about 190 to about 200 microns. In various non-limiting embodiments, all values and ranges of values, both whole and fractional, including and between those described above, are hereby expressly contemplated for use herein.
The average wear scar of the composition may also be evaluated in comparison to a comparative composition. A smaller scar diameter may indicate a better wear protection performance of the composition. In various embodiment, the composition exhibits an average wear scar diameter, as determined using HFRR screening conducted at a temperature of about 120 °C, a frequency of about 20 Hz, and a load of about 1000g, that is at least about 10, 15, 20, 25, 30, 35, 40, 45, or greater % smaller than that of a comparative composition that includes MoDTC in a comparative amount as the ester amine, but is free of the ester amine. In other words, when the composition of this disclosure is compared to a comparative composition that includes MoDTC, the instant composition has improved 4-ball wear preventative performance as described above. The terminology "in a comparative amount" means that the MoDTC is included in an amount that may or may not be the same weight or molar amount as the ester amine but is an amount that would be known to be comparative by the skilled person. In various embodiments, such an amount is about ± 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 mole or weight % different. It is contemplated that the above values may change depending on the content and type of oil (e.g. oil of lubricating viscosity) that is used for the test. In various non-limiting embodiments, all values and ranges of values, both whole and fractional, including and between those described above, are hereby expressly contemplated for use herein.
In other embodiments, the composition exhibits an average wear scar diameter, as determined using HFRR screening conducted at a temperature of about 120 °C, a frequency of about 20 Hz, and a load of about 1000g, that is at least about 10, 15, 20, 25, 30, 35, 40, 45, or greater % smaller than that of a comparative composition that includes a tallow amide in a comparative amount as the ester amine, but is free of the ester amine. In various non-limiting embodiments, all values and ranges of values, both whole and fractional, including and between those described above, are hereby expressly contemplated for use herein.
In other embodiments, the composition exhibits an average wear scar diameter, as determined using HFRR screening conducted at a temperature of about 120 °C, a frequency of about 20 Hz, and a load of about 1000g, that is at least about 10, 15, 20, 25, 30, 35, 40, 45, or greater % smaller than that of a comparative composition that includes ZDDP in a comparative amount as the ester amine, but is free of the ester amine. In various non-limiting embodiments, all values and ranges of values, both whole and fractional, including and between those described above, are hereby expressly contemplated for use herein.
The composition is not limited to any particular total base number (TBN). In various embodiments, the composition has a TBN, measured according to ASTM D2896, of from about 4 to about 15, about 5 to about 14, about 6 to about 13, about 7 to about 12, about 8 to about 11, or about 9 to about 10. In various non-limiting embodiments, all values and ranges of values, both whole and fractional, including and between those described above, are hereby expressly contemplated for use herein.
The composition is also not limited relative to viscometric description. For example, in various embodiments the composition may be described as SAE 20WX, SAE 15WX, SAE 10WX, SAE 5WX or SAE 0WX, where X represents any one of 20, 30, 40 and 50 wherein the characteristics of the different viscometric grades can be found in the SAE J300 classification. In an embodiment of each aspect, independently of the other embodiments, the composition is in the form of an SAE 10WX, SAE 5WX or SAE 0WX, In various embodiments in the form of an SAE 5WX or SAE 0WX, wherein X represents any one of 20, 30, 40 and 50. In various embodiments X is 20 or 30. Alternatively, the composition may be described as a transmission/gear oils. Typical transmission oil grades are SAE 80W, 75W-90, 80W-90 and SAE 90. Alternatively, the composition may be described as a hydraulic oil which has ISO viscosity grades and typical ISO grades such as ISO VG 32, ISO VG 46, ISO VHG 68, and ISO VG 100.

Method of Forming the Composition

The composition may be formed by any method known in the art. In various embodiments, the method includes the step of providing the oil of lubricating viscosity, providing the ester amine, and combining the oil and the ester amine to form the composition. Alternatively, the method may include the step of providing one or more additives and the step of combining the one or more additives with the oil, the ester amine, and/or with the combination of the oil and the ester amine, to form the composition. The method may include batch or continuous steps.

Method of Forming the Ester Amine

The method of forming the ester amine is not particularly limited and may be any known in the art. The method of forming the composition itself may include one or more steps of the synthesis of the ester amine. Alternatively, the ester amine may be formed entirely independently from the method of forming the composition. In such an embodiment, the ester amine may be provided in an already formed state.

EXAMPLES

General Procedure For Formation Of Lubricant Compositions and Comparative Compositions

Various ester amines were synthesized and used to form various lubricant compositions, described herein as Examples 1-3. Example 1 includes an ester amine (1A), which is synthesized from a reaction of tallow amine ethoxylate, which can be described as structure (I) wherein R¹ is a C16-C18 alkyl group and x is about 5.5, and adipic acid in a weight ratio of about 85:15. Example 1 includes the ester amine (1A) in an amount of 0.3 wt% and Group III oils in balance amount.
Similarly, Example 2 includes an ester amine (2A), which is synthesized from a reaction of tallowamine ethoxylate, which can be described as structure (I) wherein R¹ is a C16-C18 alkyl group and x is about 1, and succinic acid in a weight ratio of about 81:19. Example 2 is formed by combining Group III oils with the ester amine (2A) wherein the ester amine (2A) is present in an amount of 0.8 wt%, based on a total weight of the lubricant composition (Example 2).
Example 3 includes the ester amine (1A) in an amount of about 0.3 wt%, MoDTC in an amount of about 0.2 wt% and Group III oils in balance amount.
Comparative compositions, described herein as CE's 4 and 5, include other friction modifiers but are free of the ester amine. Specifically, CE 4 includes MoDTC in an amount of 0.2 wt% and Group III oils in balance amount. CE 5 includes N,N-bis(2-hydroxypropyl) tallow amide in an amount of 0.5 wt% and Group III oils in balance amount.

Evaluation of Physical Properties of Lubricant Compositions

The antiwear and friction-reducing performances of the Examples and CE's were measured following the same procedure.
The Examples and CE's were tested for average wear scar using a High Frequency Reciprocating Rig (HFRR) to evaluate the anti-wear properties. The protocol employed was as follows:

Load: 1000 g
Duration: 60 minutes
Frequency: 20 Hz
Standard steel ball on AISI 52100 steel

The Examples and CE's were tested for friction coefficient using a Mini Traction machine (MTM) test to evaluate the friction modification properties. The protocol employed was as follows:

Load: 20 N
Sliding to rolling ratio: 50%
Frequency: 20 Hz

The friction coefficient was constantly monitored, and the reported value is the average over three regimes (boundary, mixed and EHD). The average wear scar was measured at the end of the test using optical microscopy, and the reported value is the average of the wear scar diameter on the ball along the horizontal and vertical directions. The results of Example 1 and CE's 4 and 5 are reported in Table 1 below. Table 1. Average Friction Coefficient and Average Wear Scar Measured at 120 °C

Parameter Example 1 CE 4 CE 5

Friction Coefficient 0.02 0.05 0.09

Average Wear Scar (microns) 289 351 374
The data in Table 1 indicates that Example 1 including the ester amine exhibits better performance in terms of wear scar diameter and friction modification compared to the CE's, which include industry standards and are free of the ester amine.
The friction coefficient of Example 1, which is measured according to the procedure first described above, can further be visualized in FIGS. 1A, 1B and 1C, and compared against CE 4. FIGS. 1A, 1B, and 1C are collections of line plots of coefficient of friction versus entrainment speed, which is categorized into regimes of boundary, mixed, and an elastohydrodynamic lubrication (EHD). Each line plot shown in FIGS.1A, 1B and 1C may also be known in the art as a Stribeck curve. FIGS. 1A, 1B and 1C include the Stribeck curves of Example 1 and CE 4, measured at three different temperatures of 40 °C, 80 °C and 120 °C, respectively. In the boundary regime measured at 40 °C, Example 1 exhibits a smaller friction coefficient than CE 4, which can indicate a more efficient lubrication performance. In other regimes at 40 °C, no significant difference in the friction coefficient between Example 1 and CE 4 is observed, which can indicate a comparable lubrication performance between the lubricant composition and the industry standard MoDTC. At 80 °C and 120 °C, Example 1 exhibits a smaller friction coefficient, which can indicate a more efficient lubrication performance, in the boundary regime and the mixed regime.
The boundary regime generally occurs under high-load and low-speed conditions, e.g. bearings, gears, pumps, transmissions, etc., which can limit the durability of a mechanical component. Example 1 exhibits a smaller friction coefficient in the boundary regime compared to CE 4 at all examined temperatures, which may be beneficial in different applications, e.g. lubricant for electric vehicles, lubricant for diesel vehicles, etc. Accordingly, the data presented in FIGS. 1A, 1B and 1C shows that the lubricant composition of this disclosure provides a superior performance in friction modification compared to the art.
The lubricant composition is also unexpectedly found to exhibit synergistic effect with other friction modifiers, as shown in FIG. 2. Briefly, FIG.2 is a collection of Stribeck curves of Examples 1 and 3, and CE 4, measured at 120 °C. Surprisingly, Example 3, which includes the ester amine and MoDTC, outperforms CE 4 with respect to friction modification across all entrainment speeds. Additionally, Example 3 either outperforms Example 1, or exhibits a comparative performance in friction modification. The superior and unexpected performance of Example 3 shows the compatibility of ester amine with other friction modifiers, e.g. MoDTC.
Overall, the data above show the capability of the ester amine to significantly improve the wear prevention capability of lubricant compositions while concurrently markedly reducing the coefficient of friction of these compositions. These results are superior to what is known in the art because the results show that these compositions outperform the combined friction and wear performance of lubricant compositions including industry standards, e.g. tallow amide or MoDTC. Additionally, the lubricant composition including both the ester amine and MoDTC exhibits a synergistic effect regarding both wear prevention and friction modification.
While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment. It being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope as set forth in the appended claims.
The present disclosure may be further described with reference to the following Aspects.

Aspect 1. A lubricant composition that is ashless and comprises:
- an oil of lubricating viscosity; and
- an ester amine that is the reaction product of a diacid and/or an anhydride and an ethoxylated amine;
  - wherein the ethoxylated amine has the structure:
  - wherein R¹ is a C10-C24 alkyl or alkenyl group;
  - wherein each x is independently from about 1 to about 10; and
- wherein the ester amine is present in an amount of from about 0.05 to about 1 wt% actives, based on a total weight of the lubricant composition.
Aspect 2. The lubricant composition of Aspect 1 wherein the diacid is chosen from adipic acid, succinic acid, oxalic acid, malonic acid, glutaric acid, pimelic acid, and combinations thereof.
Aspect 3. The lubricant composition of Aspect 1 wherein the anhydride is succinic anhydride.
Aspect 4. The lubricant composition of any preceding Aspect wherein more than one ester amine is included in the lubricant composition.
Aspect 5. The lubricant composition of any preceding Aspect wherein the ester amine has a repeating unit chosen from the structures: and combinations thereof;
- wherein each R¹, R², and R³ is independently a C10-C24 alkyl or alkenyl group;
- wherein each R' is independently a C1-C5 alkyl group; and
- wherein each x and y is independently from about 1 to about 10.
Aspect 6. The lubricant composition of Aspect 5 wherein each R¹, R², and R³ is independently a C16-C18 alkyl or alkenyl group.
Aspect 7. The lubricant composition of Aspect 5 wherein each x and y is independently from about 1 to about 6.
Aspect 8. The lubricant composition of any preceding Aspect wherein the ester amine has a weight average molecular weight (M_w) of from about 1000 Da to about 15,000 Da.
Aspect 9. The lubricant composition of any preceding Aspect wherein the ester amine is present in an amount of from about 0.2 to about 0.4 wt%, based on a total weight of the lubricant composition.
Aspect 10. The lubricant composition of any preceding Aspect wherein the ethoxylated amine is tallow amine ethoxylate.
Aspect 11. The lubricant composition of any preceding Aspect the diacid and/or anhydride and the ethoxylated amine are reacted at a weight ratio of from about 5:95 to about 30:70.
Aspect 12. The lubricant composition of any preceding Aspect exhibiting a friction coefficient that is at least 20% less than that of a comparative composition that comprises molybdenum dithiocarbamate in a comparative amount to the ester amine but is free of the ester amine, as determined using a Mini Traction machine test conducted at a sliding to rolling ratio of about 50%, a load of about 20 N, and at a temperature of from about 40 °C to about 120 °C.
Aspect 13. The lubricant composition of any preceding Aspect exhibiting a friction coefficient that is at least 20% less than that of a comparative composition that comprises a tallow amide in a comparative amount to the ester amine but is free of the ester amine, as determined using a Mini Traction machine test conducted at a sliding to rolling ratio of about 50%, a load of about 20 N, and at a temperature of from about 40 °C to about 120 °C.
Aspect 14. The lubricant composition of any preceding Aspect exhibiting an average wear scar diameter that is at least 10% smaller than that of a comparative composition that comprises molybdenum dithiocarbamate and/or a tallow amide in a comparative amount to the ester amine but is free of the ester amine, as determined using High-Frequency Reciprocating Rig screening conducted at a temperature of about 120 °C, a frequency of about 20 Hz, and a load of about 1000g.
Aspect 15. The lubricant composition of any preceding Aspect further comprising molybdenum dithiocarbamate.
Aspect 16. The lubricant composition of Aspect 15 wherein the molybdenum dithiocarbamate is present in an amount of from about 0.1 to about 1 wt% actives, based on a total weight of the lubricant composition.
Aspect 17. The lubricant composition of any preceding Aspect further comprising zinc dihydrocarbyl dithiophosphate.
Aspect 18. The lubricant composition of Aspect 17 wherein the zinc dihydrocarbyl dithiophosphate is present in an amount of from about 0.1 to about 1 wt% actives, based on a total weight of the lubricant composition.
Aspect 19. A lubricant composition that is ashless and comprises:
- an oil of lubricating viscosity; and
- an ester amine that is the reaction product of adipic acid and an ethoxylated amine;
  - wherein the ethoxylated amine has the structure:
  - wherein R¹ is a C16-C18 alkyl group;
  - wherein each x is independently from about 4 to about 6; and
- wherein the ester amine is present in an amount of from about 0.05 to about 1 wt% actives, based on a total weight of the lubricant composition.
Aspect 20. A lubricant composition that is ashless and comprises:
- an oil of lubricating viscosity; and
- an ester amine that is the reaction product of succinic acid and an ethoxylated amine;
  - wherein the ethoxylated amine has the structure:
  - wherein R¹ is a C16-C18 alkenyl group;
  - wherein each x is independently from about 1 to 3; and
- wherein the ester amine is present in an amount of from about 0.05 to about 1 wt% actives, based on a total weight of the lubricant composition.

Claims

A lubricant composition that is ashless and comprises:
an oil of lubricating viscosity; and

an ester amine that is the reaction product of a diacid and/or an anhydride and an ethoxylated amine;
wherein the ethoxylated amine has the structure:

wherein R¹ is a C10-C24 alkyl or alkenyl group;

wherein each x is independently from about 1 to about 10; and

wherein the ester amine is present in an amount of from about 0.05 to about 1 wt% actives, based on a total weight of the lubricant composition.
The lubricant composition of claim 1, wherein the diacid is chosen from adipic acid, succinic acid, oxalic acid, malonic acid, glutaric acid, pimelic acid, and combinations thereof.
The lubricant composition of claims 1 or 2, wherein the anhydride is succinic anhydride.
The lubricant composition of any preceding claim, wherein more than one ester amine is included in the lubricant composition.
The lubricant composition of any preceding claim, wherein the ester amine has a repeating unit chosen from the structures: and combinations thereof;
wherein each R¹, R², and R³ is independently a C10-C24 alkyl or alkenyl group;

wherein each R' is independently a C1-C5 alkyl group; and

wherein each x and y is independently from about 1 to about 10.
The lubricant composition of claim 5, wherein each R¹, R², and R³ is independently a C16-C18 alkyl or alkenyl group; and/or
wherein each x and y is independently from about 1 to about 6.
The lubricant composition of any preceding claim, wherein the ester amine has a weight average molecular weight (M_w) of from about 1000 Da to about 15,000 Da.
The lubricant composition of any preceding claim, wherein the ester amine is present in an amount of from about 0.2 to about 0.4 wt%, based on a total weight of the lubricant composition.
The lubricant composition of claim 1, wherein the ethoxylated amine is tallow amine ethoxylate.
The lubricant composition of any preceding claim, wherein the diacid and/or anhydride and the ethoxylated amine are reacted at a weight ratio of from about 5:95 to about 30:70.
The lubricant composition of any preceding claim exhibiting a friction coefficient that is at least 20% less than that of a comparative composition that comprises molybdenum dithiocarbamate in a comparative amount to the ester amine but is free of the ester amine, as determined using a Mini Traction machine test conducted at a sliding to rolling ratio of about 50%, a load of about 20 N, and at a temperature of from about 40 °C to about 120 °C.
The lubricant composition of any preceding claim exhibiting a friction coefficient that is at least 20% less than that of a comparative composition that comprises a tallow amide in a comparative amount to the ester amine but is free of the ester amine, as determined using a Mini Traction machine test conducted at a sliding to rolling ratio of about 50%, a load of about 20 N, and at a temperature of from about 40 °C to about 120 °C.
The lubricant composition of any preceding claim exhibiting an average wear scar diameter that is at least 10% smaller than that of a comparative composition that comprises molybdenum dithiocarbamate and/or a tallow amide in a comparative amount to the ester amine but is free of the ester amine, as determined using High-Frequency Reciprocating Rig screening conducted at a temperature of about 120 °C, a frequency of about 20 Hz, and a load of about 1000g.
The lubricant composition of any preceding claim further comprising molybdenum dithiocarbamate, wherein the molybdenum dithiocarbamate is preferably present in an amount of from about 0.1 to about 1 wt% actives, based on a total weight of the lubricant composition.
The lubricant composition of any preceding claim further comprising zinc dihydrocarbyl dithiophosphate, wherein the zinc dihydrocarbyl dithiophosphate is preferably present in an amount of from about 0.1 to about 1 wt% actives, based on a total weight of the lubricant composition.