Organic anti-wear additive composition for lubricants

Abstract

An improved organic anti-wear additive composition is disclosed, comprising certain citrate esters (e.g., mixtures containing citrate oligomers) and fatty acid alkanolamides. This combination exhibits excellent and synergistic anti-wear activity in lubricants. The compositions of the present invention advantageously allow for a reduction in the amounts of zinc and phosphorus commonly used in lubricants, while improving anti-wear properties and maintaining (and often enhancing) friction-reducing properties.

Description

Background Technology

[0001] Various additives have been developed to improve the lifespan and effectiveness of lubricants, such as engine oils. These additives include antioxidants, anti-wear agents, deposit control agents, friction modifiers, and additives that improve lubricity and load-bearing properties. Some additives have more than one function; for example, zinc dialkyl dithiophosphate (ZDDP) has been used for many years as an anti-fatigue agent, anti-wear agent, antioxidant, extreme pressure agent, and friction modifier in lubricants. However, ZDDP has several drawbacks due to the presence of zinc and phosphorus.

[0002] Zinc dialkyl dithiophosphate (ZDDP) is a general term encompassing zinc dialkyl dithiophosphate, zinc diaryl dithiophosphate, zinc alkylaryl dithiophosphate, and combinations thereof. ZDDP has been used as an anti-wear additive in formulated oils for over 50 years. However, ZDDP produces ash, which contributes to particulate matter in vehicle exhaust emissions, and regulators are seeking to reduce zinc emissions into the environment. Furthermore, phosphorus is a component of ZDDP, and it is suspected of limiting the lifespan of catalytic converters used in vehicles to reduce pollution. Due to these drawbacks, efforts continue to be made to develop all-organic additives that can replace at least some of ZDDP. While limiting particulate matter and pollution generated during engine use is important for toxicological and environmental reasons, maintaining the anti-wear properties of lubricants is also crucial.

[0003] International Patent Publication No. WO 2019 / 157350 discloses certain citrate and citamide compounds, such as citrate dimers, trimers, higher oligomers, and mixtures thereof, as anti-wear and friction-modifying additives for lubricant compositions. The disclosed citrate and citamide compounds exhibit synergistic effects with zinc dihydrodithiophosphate (ZDDP), allowing for reductions in zinc and phosphorus levels, for example, by reducing the amount of ZDDP (commonly used in lubricants without sacrificing anti-wear properties). Despite these advances, efforts continue to develop all-organic additive compositions to improve anti-wear properties and reduce the amount of zinc and phosphorus in lubricant compositions. Summary of the Invention

[0004] According to this disclosure, it has been found that organic anti-wear additive compositions comprising certain citrate compounds (such as citrate dimers, trimers, higher oligomers, and mixtures thereof) as described herein, when combined with fatty acid alkanolamides, surprisingly exhibit synergistic anti-wear properties, which allows for a reduction in the level of zinc dihydrodithiophosphate (e.g., ZDDP) in the lubricant composition. Furthermore, although the use of conventional levels of ZDDP in the lubricant composition may result in decreased friction-reducing properties, the use of the synergistic combination of this disclosure leads to enhanced friction-reducing properties. Moreover, further enhanced anti-wear properties have been observed when the organic anti-wear additive compositions of this disclosure are combined with zinc dihydrodithiophosphate, thereby allowing for a further reduction in the levels of zinc and phosphorus in the lubricant composition.

[0005] In particular, an anti-wear additive composition is disclosed comprising (a) one or more citrate compounds of formula I, II, or III, or mixtures thereof, and (b) one or more fatty acid alkanolamide compounds of formula IV as described herein. In many embodiments, the weight ratio of the citrate component (a) to the fatty acid alkanolamide component (b) is 8:1 to 1:8, for example 6:1 to 1:6, 5:1 to 1:5, 4:1 to 1:4, 3.5:1 to 1:3.5, 3:1 to 1:3, 2:1 to 1:2, 1.5:1 to 1:1.5, or about 1:1.

[0006] The citrate compounds disclosed herein are represented by the following formulas I, II and III:

[0007]

[0008] Where R is an alkyl group that can be interrupted by -O-, carbonyl, carbonyloxy, carbocyclic or heterocyclic and / or substituted by OH, carbocyclic or heterocyclic.

[0009] R' is an alkylene group that can be interrupted by -O-, carbonyl, carbonyloxy, carbocyclic or heterocyclic and / or substituted by OH, carbocyclic or heterocyclic;

[0010] And n is between 1 and 20.

[0011] Unless otherwise stated, alkyl or alkylene groups may be straight-chain, branched, or cyclic, and carbocyclic or heterocyclic groups may be monocyclic, bicyclic, or polycyclic, and may be further substituted with alkyl groups.

[0012] This disclosure also provides a lubricant composition comprising A) a lubricating oil, B) 0.1 to 5 wt% of one or more citrate compounds of formula I, II, III, or mixtures thereof, based on the weight of the lubricant composition, and C) 0.1% to 5 wt% of one or more fatty acid alkanolamides, based on the weight of the lubricant composition. In many embodiments, the weight ratio of the citrate component B) to the fatty acid alkanolamide component C) is 8:1 to 1:8, for example 6:1 to 1:6, 5:1 to 1:5, 4:1 to 1:4, 3.5:1 to 1:3.5, 3:1 to 1:3, 2:1 to 1:2, 1.5:1 to 1:1.5, or about 1:1.

[0013] Many embodiments of this disclosure relate to citrate compounds of formula II or III, or mixtures of citrate compounds of formula II and III. Other embodiments relate to certain citrate compounds of formula I, such as compounds of formula I, wherein R is a carbocyclic or heterocyclic ring, an alkyl group substituted with a carbocyclic or heterocyclic ring, or an alkyl group interrupted by -O- (e.g., polyether), such as tribenzyl citrate, trinorbornelmethyl citrate, triadamantyl citrate, tri(tetrahydrofurfuryl) citrate, or tri(triethylene glycol) monomethyl ether ester, etc. Such compounds of formula I may or may not be used with other citrate compounds.

[0014] Further embodiments of the lubricant compositions disclosed herein comprise zinc dialkyl dithiophosphate, such as zinc dialkyl dithiophosphate (ZDDP). Detailed Implementation

[0015] Throughout this application, “a” or “an” means one or more, unless otherwise stated.

[0016] The organic anti-wear additive compositions disclosed herein exhibit synergistic anti-wear properties. That is, at the same total load level, the anti-wear activity of the inventive combination of citrate compound and fatty acid alkanolamide exceeds that of either citrate compound or fatty acid alkanolamide used alone. The superior activity of the combinations disclosed herein allows for the reduction of the amount of ZDDP present in lubricants while improving anti-wear properties and maintaining, and generally enhancing, friction-reducing properties.

[0017] The citrate compounds used in the compositions disclosed herein are those of formula I, II, and / or III:

[0018]

[0019]

[0020] in:

[0021] n is 1 to 20, for example, 1 to 10, 1 to 5, or 1 to 3;

[0022] R is C 1-18 alkyl;

[0023] C atoms substituted with a carbon ring containing 5 to 12 carbon atoms or a heterocycle containing 3 to 11 carbon atoms and one or more heteroatoms selected from O, S, and N 1-18 Alkyl groups, wherein the carbocyclic or heterocyclic ring can be composed of one or more C atoms. 1-12 Alkyl or alkoxy substitution;

[0024] C ions interrupted by one or more -O-, carbonyl, carbonyloxy groups and / or substituted by OH 2-18 alkyl;

[0025] C atoms interrupted by one or more -O-, carbonyl, or carbonyloxy groups and substituted by a carbon ring containing 5 to 12 carbon atoms or a heterocycle containing 3 to 11 carbon atoms and one or more heteroatoms selected from O, S, and N 2-18 Alkyl groups, wherein the carbocyclic or heterocyclic rings can be C 1-12 Alkyl or alkoxy substitution; or

[0026] A carbon ring containing 5 to 12 carbon atoms or a heterocycle containing 3 to 11 carbon atoms and one or more heteroatoms selected from O, S, and N, wherein the carbon ring or heterocycle can be C 1-12 Alkyl or alkoxy substitution; and

[0027] R' is C 2-18 Alkylene;

[0028] C atoms interrupted by one or more -O-, carbonyl or carbonyloxy groups and / or substituted by OH, a carbocyclic ring containing 5 to 12 carbon atoms, or a heterocyclic ring containing 3 to 11 carbon atoms and one or more heteroatoms selected from O, S, and N 2-18 Alkylenes, wherein the carbocyclic or heterocyclic rings can be C 1-12 Alkyl or alkoxy substitution; or

[0029] The alkylene, interrupted alkylene, or substituted alkylene is a carbon ring containing 5 to 12 carbon atoms or a heterocycle containing 3 to 11 carbon atoms and one or more heteroatoms selected from O, S, and N, wherein the carbon ring or heterocycle may be C 1-12 Alkyl or alkoxy substitution. For example, compounds of formula I, II, and / or III, wherein:

[0030] R is C 1-16 Alkyl, C 1-12 Alkyl or C 1-6 Alkyl group, wherein the alkyl group is substituted with a carbon ring comprising 5 to 12 carbon atoms or a heterocycle comprising 3 to 8 carbon atoms and one or more heteroatoms selected from O, S, and N, wherein the carbon ring or heterocycle may be substituted with one or more C atoms. 1-8 Alkyl or alkoxy substitution;

[0031] C 2-16 Alkyl, C 2-12 Alkyl or C 2-6 Alkyl group, interrupted by one or more -O-, carbonyl, carbonyloxy groups and / or substituted by a carbocyclic ring comprising 5 to 12 carbon atoms or a heterocyclic ring comprising 3 to 8 carbon atoms and one or more heteroatoms selected from O, S and N, wherein the carbocyclic ring or heterocyclic ring may be C 1-8 Alkyl or alkoxy substitution; or

[0032] A carbon ring containing 5 to 12 carbon atoms or a heterocycle containing 3 to 8 carbon atoms and one or more heteroatoms selected from O, S, and N, wherein the carbon ring or heterocycle can be made of C 1-8 Alkyl or alkoxy substitution; and

[0033] R' is C 2-16 Alkylene, C 2-12 Alkylene or C 2-8 Alkylene, wherein the alkylene is interrupted by one or more -O-, carbonyl or carbonyloxy groups and / or substituted by OH, a carbocyclic ring comprising 5 to 12 carbon atoms, or a heterocyclic ring comprising 3 to 11 carbon atoms and one or more heteroatoms selected from O, S, and N, wherein the carbocyclic or heterocyclic ring may be C 1-8 Alkyl or alkoxy substitution; or

[0034] The alkylene, interrupted alkylene, or substituted alkylene is a carbon ring containing 5 to 12 carbon atoms or a heterocycle containing 3 to 11 carbon atoms and one or more heteroatoms selected from O, S, and N, wherein the carbon ring or heterocycle may be C 1-8 Alkyl or alkoxy substitution. In many embodiments of this disclosure, the anti-wear additive composition comprises:

[0035] (a) Citrate compounds of formula II

[0036]

[0037] Citrate compounds of Formula III

[0038]

[0039] A mixture of citrate compounds of formula II and formula III,

[0040] in:

[0041] n is 1 to 20, for example, 1 to 10, 1 to 5, or 1 to 3;

[0042] R is C 1-18 Alkyl, C 1-12 Alkyl or C 1-6 alkyl;

[0043] C atoms substituted with a carbon ring containing 5 to 12 carbon atoms or a heterocycle containing 3 to 11 carbon atoms and one or more heteroatoms selected from O, S, and N 1-18 Alkyl, C 1-12 Alkyl or C 1-6 Alkyl groups, wherein the carbocyclic or heterocyclic ring can be composed of one or more C atoms. 1-12 Alkyl or alkoxy substitution;

[0044] C ions interrupted by one or more -O-, carbonyl, carbonyloxy groups and / or substituted by OH 2-18 Alkyl, C 2-12 Alkyl or C 2-6 alkyl;

[0045] C atoms interrupted by one or more -O-, carbonyl, or carbonyloxy groups and substituted by a carbon ring containing 5 to 12 carbon atoms or a heterocycle containing 3 to 11 carbon atoms and one or more heteroatoms selected from O, S, and N 2-18 Alkyl, C 2-12 Alkyl or C 2-6 Alkyl groups, wherein the carbocyclic or heterocyclic rings can be C 1-12 Alkyl or alkoxy substitution; or

[0046] A carbon ring containing 5 to 12 carbon atoms or a heterocycle containing 3 to 11 or 3 to 8 carbon atoms and one or more heteroatoms selected from O, S, and N, wherein the carbon ring or heterocycle can be C 1-12 Or C 1-8 Alkyl or alkoxy substitution; and R' is C 2-18 Alkylene, C 2-12 Alkylene or C 2-8 Alkylene;

[0047] C atoms interrupted by one or more -O-, carbonyl or carbonyloxy groups and / or substituted by OH, a carbocyclic ring containing 5 to 12 carbon atoms, or a heterocyclic ring containing 3 to 11 carbon atoms and one or more heteroatoms selected from O, S, and N 2-18 Alkylene, C 2-12 Alkylene or C 2-8 Alkylenes, wherein the carbocyclic or heterocyclic ring can be C 1-12 Alkyl or alkoxy substitution; or

[0048] The alkylene, interrupted alkylene, or substituted alkylene is a carbon ring containing 5 to 12 carbon atoms or a heterocycle containing 3 to 11 carbon atoms and one or more heteroatoms selected from O, S, and N, wherein the carbon ring or heterocycle may be C 1-12 Or C 1-8 Alkyl or alkoxy substitution;

[0049] Each R and each R' can be the same as or different from any other R or R';

[0050] and

[0051] (b) Formula IV fatty acid alkylamide

[0052]

[0053] Where n is 1 or 2; when n is 1, m is 1; when n is 2, m is 0.

[0054] R 1 For H or C 1-12 Alkyl (e.g., C10) 1-8 Alkyl or C 1-4 Alkyl group (such as methyl or ethyl), where G is H or C. 1-6 Alkyl, and

[0055] R 2 Selected from C 7-23 Alkyl or alkenyl (e.g., C10) 7-19 alkyl or alkenyl, or C 9-19 (alkyl or alkenyl).

[0056] Typically, the weight ratio of the citrate ester component (a) to the fatty acid alkanolamide component (b) is 8:1 to 1:8, for example, 6:1 to 1:6, 5:1 to 1:5, 4:1 to 1:4, 3.5:1 to 1:3.5, 3:1 to 1:3, 2:1 to 1:2, 1.5:1 to 1:1.5, or about 1:1.

[0057] In many embodiments, the anti-wear additive composition comprises more than one citrate compound of formula III, differing only in having different n values.

[0058] In many embodiments, the citrate component (a) of the anti-wear composition further comprises a citrate compound of formula I.

[0059]

[0060] R is as described above.

[0061] In another embodiment, the anti-wear additive composition comprises at least one citrate compound of formula I, at least one citrate compound of formula II, and at least one citrate compound of formula III, wherein n is 1 to 5, and R is C 1-12 Alkyl groups or C groups interrupted by one or more -O- groups 2-12 Alkyl group, and R' is C 2-12 Alkylene or alkylene interrupted by one or more -O-.

[0062] In yet another embodiment of this disclosure, the anti-wear additive composition comprises:

[0063] (a) Citrate compounds of formula I

[0064]

[0065] Wherein R is a carbon ring containing 5 to 12 carbon atoms or a hetero ring containing 3 to 11 carbon atoms and one or more heteroatoms selected from O, S, and N, wherein the carbon ring or hetero ring can be C 1-12 Alkyl or alkoxy substitution;

[0066] C atoms substituted with a carbon ring containing 5 to 12 carbon atoms or a heterocycle containing 3 to 11 carbon atoms and one or more heteroatoms selected from O, S, and N 1-6 Alkyl groups, wherein the carbocyclic or heterocyclic ring can be composed of one or more C atoms. 1-12 Alkyl or alkoxy substitution;

[0067] C ions interrupted by one or more -O-, carbonyl or carbonyl groups and / or substituted with OH 6-18 Alkyl; or

[0068] C atoms interrupted by one or more -O-, carbonyl or carbonyloxy groups and substituted by OH, a carbocyclic ring containing 5 to 12 carbon atoms, or a heterocyclic ring containing 3 to 11 carbon atoms and one or more heteroatoms selected from O, S, and N. 6-18 Alkyl groups, wherein the carbocyclic or heterocyclic rings can be C 1-12 Alkyl or alkoxy substitution; and

[0069] (b) Fatty acid alkanolamides of formula IV as described above.

[0070] Typically, the weight ratio of the citrate ester component (a) to the fatty acid alkanolamide component (b) is 8:1 to 1:8, for example, 6:1 to 1:6, 5:1 to 1:5, 4:1 to 1:4, 3.5:1 to 1:3.5, 3:1 to 1:3, 2:1 to 1:2, 1.5:1 to 1:1.5, or about 1:1.

[0071] For example, R in a citrate compound of formula I can be tribenzyl, trinorbornelmethyl, triadamantyl, tri(tetrahydrofurfuryl), or tri(triethylene glycol) monomethyl ether ester, etc. Such a compound of formula I may or may not be used with other citrate esters.

[0072] The alkyl group described above can be a straight-chain alkyl group or a branched alkyl group, and the alkylene group can be a straight-chain alkylene group or a branched alkylene group. An alkylene group refers to a hydrocarbon-based chain or group attached to two other groups, also known as an alkyl-diyl group. The carbocyclic and heterocyclic rings can be aromatic or non-aromatic, monocyclic or polycyclic. Alkyl or alkylene groups interrupted by -O- can be ethers, for example, R can be as shown in parentheses:

[0073]

[0074] Or polyether, for example, R' can be as shown in parentheses:

[0075]

[0076] In some exemplary implementations:

[0077] R is ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, benzyl, norbornelmethyl, adamantyl, tetrahydrofurfuryl, triethylene glycol monomethyl ether, and their isomers, such as isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, tert-pentyl, 2-ethylhexyl, etc.; and

[0078] R' represents ethylenediyl; propane 1,2- or 1,3-diyl; butane 1,4-, 1,2- or 1,3-diyl; pentane 1,5- or 1,4-diyl; hexane 1,6-diyl; 2-ethylhexane 1,6-diyl; etc.

[0079] Citrate compounds of formulas I, II, and III can be prepared according to the methods described in International Patent Publication No. WO 2019 / 157350. For example, citrate of formula I can be prepared by any known esterification method. In one embodiment, citrates of formulas II and III can be prepared by reacting citric acid with a polyol (e.g., a diol) in the presence of an acid catalyst (e.g., methanesulfonic acid) to obtain dimers, trimers, various other oligomers, etc., depending on the relative amounts of citric acid and polyol used, followed by standard esterification of the remaining carboxylic acid group, for example, by reacting with a monohydric alcohol in the presence of an acid, i.e., a two-step method. In an alternative method, citric acid can be reacted simultaneously with an alcohol (e.g., butanol) and a diol (e.g., 1,6-hexanediol) in the same vessel in the presence of a catalyst (e.g., an acid catalyst), i.e., a one-step method.

[0080] Typically, depending on the method of preparation of the compound of Formula III, mixtures of compounds of Formula III with different n values ​​will exist in different amounts. For example, when the main preparation is of a trimer, i.e., a compound of Formula III where n = 1, dimers, monomers, tetramers, and pentamers are usually also present. Similarly, when the main preparation is of a compound of Formula II, monomers and compounds of Formula III are usually also present. In some embodiments, such mixtures of compounds are desirable because mixtures can exhibit higher solubility than single components.

[0081] Many embodiments of this disclosure utilize the above-described one-step or two-step method to generate mixtures of citrate compounds containing varying amounts of compounds of formulas II and III with different n values. Typically, these mixtures also contain compounds of formula I. The amounts of desired components can be increased by changing the conditions, and the mixtures can be separated using standard techniques if necessary.

[0082] Exemplary citrate compounds used in this disclosure include, but are not limited to, tris(tetrahydrofurfuryl) citrate, ethyl-tetrahydrofurfuryl citrate, tris(1-adamantyl) citrate, tris(2-adamantyl) citrate, tris(2-norbornelalkylmethyl) citrate, tris(triethylene glycol monomethyl ether) citrate, and tribenzyl citrate.

[0083] In many embodiments, the citrate compound used according to this disclosure is selected from dialkyl citrate diol-linked oligomers, for example, wherein the alkyl group is C10. 2-12 Alkyl, C 2-8 Alkyl or C 2-6 Alkyl groups (e.g., ethyl, propyl, butyl, pentyl, hexyl, heptyl, or octyl), and the glycol linker is ethylene glycol, propane 1,2 or 1,3 diol, butane 1,4, 1,2 or 1,3 diol, pentane 1,5 or 1,4 diol, hexane 1,6 diol, or 2-ethylhexane 1,6 diol. For example, the citrate compound may be selected from oligomers linked with dihexyl citrate diol, such as oligomers of dihexyl citrate linked via ethane-1,2 diol, propane-1,2 diol, or butane-1,4 diol linkers.

[0084] The fatty acid alkylolamide disclosed herein is a compound of formula IV:

[0085]

[0086] Where n is 1 or 2; when n is 1, m is 1; when n is 2, m is 0.

[0087] R 1 For H or C 1-12 Alkyl (e.g., C10) 1-8 Alkyl or C 1-4 Alkyl groups, such as methyl or ethyl groups,

[0088] G is H or C 1-6 Alkyl, and

[0089] R 2 Selected from C 7-23 Alkyl or alkenyl (e.g., C10) 7-19 alkyl or alkenyl, or C 9-19 (alkyl or alkenyl).

[0090] In another embodiment, the fatty acid alkanolamide of formula IV is a compound of formula V:

[0091]

[0092]

[0093] Where R 1 Is it H or C? 1-12 Alkyl (e.g., C10) 1-8 Alkyl or C 1-4 Alkyl groups, such as methyl or ethyl, and R 2 Selected from C 7-23 Alkyl or alkenyl (e.g., C10) 7-19 alkyl or alkenyl, or C 9-19 (alkyl or alkenyl).

[0094] The fatty acid alkanolamides disclosed herein can be prepared by known methods, such as the reaction between an alkanolamine and a carboxylic acid or a carboxylic acid derivative (e.g., esters, acyl chlorides, etc.). Although individual amides can be prepared and mixed, mixtures of compounds can be conveniently prepared by using more than one alkanolamine and / or more than one carboxylic acid or a carboxylic acid derivative during the reaction.

[0095] In some embodiments, the fatty acid alkyl alcohol amide is a compound of formula IV or V, wherein R 1 Selected from C 1-12 Alkyl, such as C 1-8 Alkyl or C 1-4 Alkyl groups, such as methyl or ethyl. Exemplary fatty acid alkanolamides of formulas IV and V and methods for their preparation are found in US 9,562,207, which is incorporated herein by reference for this purpose.

[0096] C 1-12 Alkyl and C 1-6 Alkyl (e.g., C) 1-8 Alkyl or C 1-4 Alkyl groups represent a fully saturated straight or branched chain with a specified number of carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, isobutyl, tert-butyl, pentyl, sec-pentyl, tert-pentyl, hexyl, methylpentyl, ethylbutyl, etc.

[0097] C 7-23 Alkyl or alkenyl (e.g., C10) 7-19 alkyl or alkenyl, or C 9-19 Alkyl or alkenyl) indicates a straight or branched chain with a specified number of carbon atoms, which is fully saturated in the case of alkyl, or contains one or more carbon-carbon double bonds in the case of alkenyl.

[0098] The two Rs in equation V 1 The functional groups can be the same or different. For example, each R1 It can be independently selected from H, methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, isobutyl, and tert-butyl. In some embodiments, R 1 It is methyl or ethyl. In some embodiments, each R 1 It is a methyl group.

[0099] In many embodiments, fatty acid alkanolamides are mixtures of compounds. For example, in many embodiments, R is used. 2 A mixture of compounds of different formulas IV or V. In such a mixture, for example, at least one compound wherein R is present. 2 It is C 15 Compounds of formula IV or V, which are alkyl or alkenyl, and at least one wherein R 2 It is C 17 Compounds of formula IV or V, either alkyl or alkenyl. In some embodiments, the majority of R in the mixture... 2 The group is selected from C 13 C 15 and C 17 Alkyl or alkenyl (which are derived from C) 14 C 16 and C 18 (related to fatty acid products), for example, in some embodiments, most of the R in the mixture 2 The group is C 15 and / or C 17 Alkyl or alkenyl groups. In many embodiments, both alkyl and alkenyl groups are present in the R group of the amide mixture. 2 Place.

[0100] Carboxylic acids or their derivatives used in the preparation of alkanolamides have a variety of natural sources, such as fats and oils, including canola oil, corn oil, coconut oil, sunflower oil, soybean oil, lard, palm oil, tallow, cocoa butter, and illipe, which provide mixtures of carboxylic acids and their derivatives. Carboxylic acids or their derivatives can react with di(hydroxyalkyl)amines. US 9,562,207 has shown particular value in the preparation of fatty acid alkanolamides from bis(2-hydroxypropyl)amine and methyl esters derived from beef tallow carboxylate.

[0101] The carboxylic acid groups in fats and oils are usually present in the form of esters. For example, beef tallow contains palmitic acid (saturated C42-C ... 16 (acid), stearic acid (saturated C) 18 ), oleic acid (monounsaturated C) 18 Esters such as glycerides, diglycerides, and triglycerides (of acids), as well as small amounts of polyunsaturated C 18Acids and other fatty acids. Therefore, using tallow as a source of the alkyl carboxyl moiety of alkanolamides provides a mixture primarily of palmitamide, stearamide, and oleamide, where R... 2 C 15 Alkyl, C 17 Alkyl and C 17 Alkenyl compounds of formula V.

[0102] Obtained natural sources, such as mixtures of glycerides, can be used, or natural mixtures of products can be hydrolyzed into mixtures of fatty acids or otherwise converted, such as by transesterification with a smaller alcohol, before use. For example, tallow triglycerides can be reacted with methanol to provide a mixture of methyl tallow esters, which can then be reacted with the desired amine; tallow triglycerides can be hydrolyzed into a mixture of tallow acids and then reacted with an amine; or the triglycerides can be reacted directly with an amine. Each of these methods can be used to prepare the same or similar amide mixtures; however, the processing conditions and byproducts may differ.

[0103] In some embodiments, the fatty acid alkanolamide is a mixture of compounds of formula IV or V, wherein

[0104] By weight, approximately 15% to approximately 45% of the alkanolamide is R. 2 C 15 Alkyl or alkenyl compounds,

[0105] By weight, approximately 40% to approximately 80% of the alkanolamides are R. 2 C 17 Alkyl or alkenyl compounds, and

[0106] The alkanolamide is 0 or 0.1% to about 15%, or 2% to 15% by weight, of which R 2 C 7-14 C 16 Or C 18-19 Alkyl or alkenyl compounds;

[0107] For example, among them

[0108] By weight, approximately 20% to approximately 35% of the alkanolamide is R. 2 C 15 Alkyl or alkenyl compounds,

[0109] By weight, approximately 50% to approximately 75% of the alkanolamide is R. 2 C 17 Alkyl or alkenyl compounds, and

[0110] By weight, 0% to about 15%, or 2% to 15%, of the alkanolamide is R. 2 C 7-14 C16 Or C 18-19 The alkyl or alkenyl compound, in some embodiments, contains 0 or 2% to about 15% by weight of an alkanolamide, wherein R is... 2 C 9-14 C 16 Or C 18-19 Compounds with alkyl or alkenyl groups.

[0111] In some embodiments, about 30% to about 70% by weight of the alkanolamide is R. 2 C 7-19 Alkyl compounds, and by weight about 30% to about 70% of which R is present. 2 C 7-19 Alkenyl compounds.

[0112] In some embodiments, the fatty acid alkanolamide is a mixture of compounds of formula IV or V, wherein

[0113] By weight, approximately 15% to approximately 45%, for example, approximately 20% to approximately 35%, of which alkanolamides are R 2 C 15 Alkyl or alkenyl compounds, wherein the majority, for example, about 75% or more, 90% or more, or 95% or more C 15 The alkyl or alkenyl group is alkyl;

[0114] By weight, approximately 40% to approximately 80%, for example, approximately 50% to approximately 75%, of the alkanolamides is R. 2 C 17 Alkyl or alkenyl compounds, wherein about 40% to about 95% of the C 17 Alkyl or alkenyl is an alkenyl group; and

[0115] Alkylamides, by weight, comprise 0 or 1% to approximately 15% of R. 2 C 7-14 C 16 Or C 18-19 Alkyl or alkenyl, for example C 9-14 C 16 Or C 18-19 Compounds with alkyl or alkenyl groups.

[0116] In some embodiments, about 15% to about 45% of the alkanolamide is R. 2 For fully saturated C 15 Alkyl compounds, and some alkanolamides, are among them as C 17 R 2 It is a compound that is saturated alkyl and partially alkenyl. In some embodiments, about 20% to about 35% by weight of the alkanolamide is present in which R... 2 It is a fully saturated C15 Alkyl groups and present as R 2 C 17 Alkyl and C 17 Alkenyl compounds.

[0117] In some embodiments, the anti-wear additive composition of this disclosure consists essentially of a citrate ester component (a) and a fatty acid alkanolamide component (b), as described herein, as an activator. In some embodiments, the anti-wear additive composition is completely organic. In some embodiments, the anti-wear additive composition is metal-free. In other embodiments, the anti-wear additive composition is metal-free, phosphorus-free, and sulfur-free. In other embodiments, the anti-wear additive composition further comprises ZDDP. In other embodiments, the anti-wear additive composition consists essentially of a citrate ester component (a), a fatty acid alkanolamide component (b), and ZDDP as an activator. In many embodiments, the weight ratio of the citrate ester component (a) to ZDDP is 4:1 to 1:4, for example 3:1 to 1:3, 2:1 to 1:2, 1.5:1 to 1:1.5, 2:1 to 1:1, or 1:1 to 1:2.

[0118] In another aspect, this disclosure relates to lubricant compositions comprising A) a lubricating oil, B) one or more citrate compounds of formula I, II, III, or mixtures thereof as described above, in an amount of 0.1 to 5 wt%, such as 0.15 to 4 wt%, 0.2 to 3 wt%, 0.25% to 2.5 wt%, 0.3% to 2.0 wt%, 0.4% to 1.5%, 0.45% to 1.25%, or 0.5% to 1.0% based on the weight of the lubricant composition, and C) a fatty acid alkanolamide of formula IV as described herein, in an amount of 0.1 to 5 wt%, such as 0.15 to 4 wt%, 0.2 to 3 wt%, 0.25 to 2.5 wt%, 0.3% to 2.0 wt%, 0.4% to 1.5%, 0.45% to 1.25%, or 0.5% to 1.0% based on the weight of the lubricant composition. Typically, the weight ratio of citrate component B) to fatty acid alkanolamide component C) is 8:1 to 1:8, for example 6:1 to 1:6, 5:1 to 1:5, 4:1 to 1:4, 3.5:1 to 1:3.5, 3:1 to 1:3, 2:1 to 1:2, 1.5:1 to 1:1.5, or about 1:1.

[0119] In many embodiments, the lubricant composition comprises:

[0120] A) Lubricating oil,

[0121] B) Based on the weight of the lubricant composition, 0.1 to 5 wt% (e.g., as described above)

[0122] The citrate compound of formula II above, or

[0123] The citrate compound of formula III above, or

[0124] A mixture of citrate compounds of formula II and formula III,

[0125] Where n, R, and R' are as described above; and

[0126] C) Based on the weight of the lubricant composition, 0.1 to 5 wt% (e.g., as described above) of a fatty acid alkanolamide of formula IV as described above.

[0127] In many embodiments, the weight ratio of citrate component B) to fatty acid alkanolamide component C) is 8:1 to 1:8, as described above.

[0128] In many embodiments, the lubricant composition further comprises a citrate ester compound of Formula I as described above, wherein R is as described above, and the total wt% of all citrate ester compounds of Formulas I, II, and III combined is 0.1 to 5 wt%, for example 0.15 to 4 wt%, 0.2 to 3 wt%, 0.25% to 2.5 wt%, 0.3% to 2.0 wt%, 0.4% to 1.5%, 0.45% to 1.25%, or 0.5% to 1.0%, based on the weight of the lubricant composition.

[0129] In another embodiment, the lubricant composition comprises at least one citrate compound of formula I, at least one citrate compound of formula II, and at least one citrate compound of formula III, wherein n is 1 to 5, and R is C 1-12 Alkyl groups or C groups interrupted by one or more -O- groups 2-12 Alkyl group, and R' is C 2-12 Alkylene, or alkylene interrupted by one or more -O-.

[0130] In other embodiments, the lubricant composition comprises:

[0131] A) Lubricating oil,

[0132] B) Based on the weight of the lubricant composition, 0.1 to 5 wt%, for example 0.15 to 4 wt%, 0.2 to 3 wt%, 0.25% to 2.5 wt%, 0.3% to 2.0 wt%, 0.4% to 1.5%, 0.45% to 1.25%, or 0.5% to 1.0% of a citrate ester compound of Formula I above.

[0133] Wherein R is a carbon ring containing 5 to 12 carbon atoms or a hetero ring containing 3 to 11 carbon atoms and one or more heteroatoms selected from O, S, and N, wherein the carbon ring or hetero ring can be C 1-12 Alkyl or alkoxy substitution;

[0134] C atoms substituted with a carbon ring containing 5 to 12 carbon atoms or a heterocycle containing 3 to 11 carbon atoms and one or more heteroatoms selected from O, S, and N 1-6 Alkyl groups, wherein the carbocyclic or heterocyclic ring can be composed of one or more C atoms. 1-12 Alkyl or alkoxy substitution;

[0135] C ions interrupted by one or more -O-, carbonyl or carbonyl groups and / or substituted with OH 6-18 Alkyl; or

[0136] C atoms interrupted by one or more -O-, carbonyl, or carbonyloxy groups and substituted by OH, a carbocyclic ring containing 5 to 12 carbon atoms, or a heterocyclic ring containing 3 to 11 carbon atoms and one or more heteroatoms selected from O, S, and N. 6-18 Alkyl groups, wherein the carbocyclic or heterocyclic rings can be C 1-12 Alkyl or alkoxy substitution; and

[0137] C) Based on the weight of the lubricant composition, 0.1 to 5 wt%, for example 0.15 to 4 wt%, 0.2 to 3 wt%, 0.25% to 2.5 wt%, 0.3% to 2.0 wt%, 0.4% to 1.5%, 0.45% to 1.25%, or 0.5% to 1.0% of the fatty acid alkanolamide of formula IV as described above.

[0138] Typically, the weight ratio of citrate component B) to fatty acid alkanolamide component C) is 8:1 to 1:8, for example 6:1 to 1:6, 5:1 to 1:5, 4:1 to 1:4, 3.5:1 to 1:3.5, 3:1 to 1:3, 2:1 to 1:2, 1.5:1 to 1:1.5, or about 1:1.

[0139] For example, R in the citrate compound of Formula I can be tribenzyl, trinorbornelmethyl, triadamantyl, tri(tetrahydrofurfuryl), or tri(triethylene glycol) monomethyl ether ester, etc. This compound of Formula I may or may not be used with other citrate esters.

[0140] In another embodiment, the lubricant composition comprises the lubricating oil component A), citrate component B), and fatty acid alkanolamide component C as described above, and further comprises ZDDP as component D. In many embodiments, ZDDP is present at 0.1 to 2.5 wt% based on the weight of the lubricant composition, for example, 0.1 to 2 wt%, 0.1 to 1.5 wt%, 0.5 to 2 wt%, 0.5 to 1.5 wt%, or 0.5 to 1 wt%. Typically, the weight ratio of citrate component B) to ZDDP component D) is 4:1 to 1:4, for example, 3:1 to 1:3, 2:1 to 1:2, 1.5:1 to 1:1.5, 2:1 to 1:1, or 1:1 to 1:2.

[0141] Lubricant compositions typically contain a variety of other additives, such as dispersants, detergents, corrosion / rust inhibitors, antioxidants, anti-wear agents, defoamers, friction modifiers, sealant swelling agents, demulsifiers, VI modifiers, pour point depressants, etc. Samples of these additives can be found, for example, in U.S. Patent Nos. 5,498,809 and 7,696,136, the relevant portions of each of which are incorporated herein by reference, although it is clear to those skilled in the art that this constitutes only a partial list of available lubricant additives. It is also well known that an additive may provide or improve more than one property; for example, anti-wear agents may also be used as anti-fatigue and / or extreme pressure additives.

[0142] The lubricant compositions disclosed herein typically contain any amount of these additives. Therefore, the lubricant compositions typically contain an inventive combination of additives with the citrate ester component and fatty acid alkanolamide component of this disclosure, optionally further combined with ZDDP. Based on the total weight of the lubricant composition, the total combined additives can range, for example, from about 0.5 to about 30% by weight, such as from about 0.5 to about 20, about 15, or about 10% by weight. For example, the combined additives can be present in an amount from about 1 to about 5, or about 10% by weight. An oil concentrate of the additives may contain, for example, from about 30 to about 75% by weight of the additives.

[0143] Given the prevalence of additives in lubricant formulations, the amount of lubricating oil present in the lubricant composition of the present invention is not specified above. However, in most embodiments, in addition to the additive concentrate, the lubricating oil is the main component, i.e., it is present in more than 50 wt% based on the weight of the composition, such as 60 wt% or more, 70 wt% or more, 80 wt% or more, 90 wt% or more, or 95 wt% or more.

[0144] Lubricating oils can be of any lubricating viscosity. For example, a lubricating oil base feedstock is any natural or synthetic lubricating oil base feedstock fraction with a kinematic viscosity of about 2 to about 200 cSt, about 3 to about 150 cSt, and typically about 3 to about 100 cSt at 100°C. Lubricating oil base feedstocks can be derived from natural lubricating oils, synthetic lubricating oils, or mixtures thereof. Suitable lubricating oil base feedstocks include, for example, petroleum, mineral oils, and oils derived from coal petroleum or shale oil, animal fats (such as lard), vegetable oils (such as rapeseed oil, castor oil, and sunflower oil), and synthetic oils.

[0145] Synthetic oils include hydrocarbon oils and halogenated hydrocarbon oils, such as polymerized and interpolymerized olefins, gas-to-liquids produced by the Fischer-Tropsch process, alkylbenzenes, polybenzene, alkylated diphenyl ethers, alkylated diphenyl sulfides, and their derivatives, analogs, and homologues. Synthetic lubricants also include epoxy alkyl polymers, interpolymers, copolymers, and their derivatives, wherein the terminal hydroxyl groups have been modified by esterification, etherification, etc. Another suitable class of synthetic lubricants includes esters of dicarboxylic acids with various alcohols. Esters used as synthetic oils also include those made from monocarboxylic acids or diacids with polyols and polyol ethers. Other esters used as synthetic oils include those made from copolymers of α-olefins and dicarboxylic acids (esterified with short-chain or medium-chain alcohols).

[0146] Silicone-based oils (such as polyalkyl-, polyaryl-, polyalkoxy-, or polyaryloxy-siloxane oils and silicate ester oils) comprise another class of useful synthetic lubricants. Other synthetic lubricants include phosphoric acid-containing liquid esters, polymeric tetrahydrofurans, polyalphaolefins, etc.

[0147] Lubricating oils can be derived from unrefined, refined, refined oils, or mixtures thereof. Unrefined oils are obtained directly from natural or synthetic sources (e.g., coal, shale, or tar and bitumen) without further purification or treatment. Examples of unrefined oils include shale oils obtained directly from carbonization operations, petroleum obtained directly from distillation, or ester oils obtained directly from esterification processes, each of which is then used without further processing. Refined oils are similar to unrefined oils, except that they undergo one or more purification steps to improve one or more properties. Suitable purification techniques include distillation, hydrotreating, dewaxing, solvent extraction, acid or alkali extraction, filtration, percolation, etc., all of which are well known to those skilled in the art. Refined oils are obtained by processing refined oils in processes similar to those used to obtain refined oils. These refined oils are also called recycled oils or reprocessed oils and are typically further processed using techniques to remove waste additives and oil decomposition products.

[0148] Hydroisomerized lubricating oil bases derived from waxes can also be used, either alone or in combination with the aforementioned natural and / or synthetic bases. These wax isomers are produced by the hydroisomerization of natural or synthetic waxes, or mixtures thereof, over a hydroisomerization catalyst. Natural waxes are typically slackwax recovered through solvent dewaxing of mineral oils; synthetic waxes are typically produced via the Fischer-Tropsch process. The resulting isomerization products are usually subjected to solvent dewaxing and fractionation to recover various fractions with specific viscosity ranges. Wax isomers are also characterized by very high viscosity indices (typically at least 130, preferably at least 135 or higher), and after dewaxing, pour points of about -20°C or lower.

[0149] The organic citrate and fatty acid alkanolamide additives disclosed herein can be added directly to lubricating oils, either in combination or as individual components. These additives, individually or in mixtures thereof, can be added separately or together with other commonly used additives (e.g., as part of an additive package). Concentrates containing these additives can also be prepared and added to lubricating oils. The citrate and fatty acid alkanolamide components can also be added to preformed lubricating oils that already contain all or most of the other formulation components. For example, preformed lubricating oils containing many or all other formulation components can be top-treated with the citrate and fatty acid alkanolamide additives of this disclosure, or with either of them (if the formulation already contains the other).

[0150] The lubricant compositions disclosed herein can be used in a variety of applications, such as crankcase lubricants for spark-ignited and compression-ignited internal combustion engines, gas engine lubricants, turbine lubricants, automatic transmission fluids, gear lubricants, compressor lubricants, metalworking lubricants, hydraulic fluids, damping fluids, and other lubricant and grease compositions.

[0151] Further non-limiting disclosures are provided in the following embodiments.

[0152] Example

[0153] Example 1

[0154] Citrate component (citrate-1):

[0155] Propane-1,2-dimethylbis(dihexyl citrate) oligomers were prepared by the reaction of citric acid, hexanol and 1,2-propanediol in the presence of an acid catalyst.

[0156] Fatty acid alkanolamides:

[0157] From LANXESS RC 3502 is bis(2-hydroxypropyl) tallow amide.

[0158] Zinc dialkyl dithiophosphate (ZDDP).

[0159] lubricating oil:

[0160] 5W-30 oil (fully formulated, but without any anti-wear or friction-modifying additives, "STD").

[0161] A lubricant composition containing a reference 5W-30 oil (STD) and additives in the weight percentages shown in Table 1a was prepared, and its anti-wear properties were tested using the ASTM D4172 four-ball wear test, in which three hardened steel balls were placed in contact with the test fluid under a 40 kg load, and a fourth ball was rotated at 1200 rpm for 1 hour while the test sample was heated at 75°C. After the test, the wear track diameter of each of the three captured stationary balls was measured in two perpendicular directions, and the average wear track (in millimeters) was reported.

[0162] Table 1a

[0163]

[0164] The results showed that the combination of the citrate and alkanolamide components had a synergistic effect on anti-wear performance. In other words, at the same total load level, the anti-wear activity of this combination was significantly enhanced compared to the activity of each of the citrate and fatty acid alkanolamide components tested individually.

[0165] Furthermore, the three-way combination of citrate ester, fatty acid alkanolamide, and ZDDP exhibits further enhanced anti-wear activity, as shown in Table 1b. Therefore, this invention allows for the use of all-organic anti-wear additive compositions to achieve excellent anti-wear properties, and, if combined with ZDDP, achieves further enhanced anti-wear properties, while allowing for a reduction in the ZDDP content level in lubricant formulations.

[0166] Table 1b

[0167]

[0168]

[0169] Similar results are shown in the following additional embodiments.

[0170] Example 2

[0171] The lubricant composition was prepared and tested according to Example 1, except that the citrate component (citrate-2) was a butane-1,4-dimethylbis(dihexyl citrate) oligomer, which was prepared by the reaction of citric acid, hexanol and 1,4-butanediol in the presence of an acid catalyst. Samples and results are shown in Tables 2a and 2b.

[0172] Table 2a

[0173]

[0174] Table 2b

[0175]

[0176] Example 3

[0177] The lubricant composition was prepared and tested according to Example 1, except that the citrate component (citrate-3) was a hexane-1,6-dimethylbis(dihexyl citrate) oligomer, which was prepared by the reaction of citric acid, hexanol, and 1,6-hexanediol in the presence of an acid catalyst. Samples and results are shown in Tables 3a and 3b.

[0178] Table 3a

[0179]

[0180] Table 3b

[0181]

[0182] Example 4

[0183] The lubricant composition was prepared and tested according to Example 1, except that the citrate component (citrate-4) was an ethane-1,2-dimethylbis(dihexyl citrate) oligomer, which was prepared by reacting citric acid, hexanol, and 1,2-ethylene glycol in the presence of an acid catalyst. Samples and results are shown in Tables 4a and 4b.

[0184] Table 4a

[0185]

[0186] Table 4b

[0187]

[0188] Although specific embodiments of the invention have been described and illustrated, this description is not intended to be limiting. Various changes and modifications may be made without departing from the principles and scope of the invention as defined by the appended claims.

Claims

1. An anti-wear additive composition comprising: (a) a citrate ester compound of Formula II or a citrate ester compound of Formula III or a mixture of citrate ester compounds of Formula II and Formula III, wherein: n is 1 to 20; R is C 1-18 alkyl; C substituted by a carbocycle comprising 5 to 12 carbon atoms or a heterocycle comprising 3 to 11 carbon atoms and one or more heteroatoms selected from O, S and N 1-18 alkyl, wherein the carbocycle or heterocycle can be substituted by one or more C 1-12 alkyl or alkoxy; C ions interrupted by one or more -O-, carbonyl, carbonyloxy groups and / or substituted by OH 2-18 alkyl; C interrupted by one or more -O-, carbonyl or carbonyloxy and substituted by a carbocycle containing 5 to 12 carbon atoms or a heterocycle containing 3 to 11 carbon atoms and one or more heteroatoms selected from the group consisting of O, S and N 2-18 alkyl, wherein the carbocycle or heterocycle can be substituted by C 1-12 alkyl or alkoxy; or carbocycle comprising 5 to 12 carbon atoms or a heterocycle comprising 3 to 11 carbon atoms and one or more heteroatoms selected from the group consisting of O, S and N, wherein the carbocycle or heterocycle can be substituted by C 1-12 alkyl or alkoxy; and R' is C 2-18 alkylene; C interrupted by one or more -O-, carbonyl or carbonyloxy and / or substituted by OH, a carbocycle comprising 5 to 12 carbon atoms or a heterocycle comprising 3 to 11 carbon atoms and one or more heteroatoms selected from the group consisting of O, S and N 2-18 alkylene, wherein the carbocycle or heterocycle can be substituted by C 1-12 alkyl or alkoxy; or carbocycle containing 5 to 12 carbon atoms or said alkylene, interrupted alkylene or substituted alkylene containing 3 to 11 carbon atoms interrupted by one or more heteroatoms selected from the group consisting of O, S and N, wherein the carbocycle or heterocycle can be substituted by C 1-12 alkyl or alkoxy; wherein each R and each R' can be the same or different from any other R or R'; and (b) a fatty acid alkanolamide of Formula IV wherein n is 1 or 2; when n is 1, m is 1; when n is 2, m is 0, R 1 is H or C 1-12 alkyl, G is H or C 1-6 alkyl, and R 2 selected from C 7-23 alkyl or alkenyl; wherein the weight ratio of citrate ester component (a) to fatty acid alkanolamide component (b) is 2: 1 to 1:

8.

2. The anti-wear additive composition of claim 1, wherein the composition comprises more than one citrate ester compound of Formula III that differs by having different n values.

3. The anti-wear additive composition of claim 1, wherein component (a) further comprises a citrate ester compound of Formula I wherein R is described for Formula II and III.

4. The anti-wear additive composition of claim 3, wherein the additive composition comprises at least one citrate compound of Formula I, at least one citrate compound of Formula II, and at least one citrate compound of Formula III, wherein n is 1 to 5; R is C 1-12 alkyl or C 2-12 alkyl interrupted by one or more -O-, and R' is C 2-12 alkylene or said alkylene interrupted by one or more -O-.

5. An anti-wear additive composition comprising: (a) a citrate ester compound of Formula I wherein R is a carbocyclic ring comprising 5 to 12 carbon atoms or a heterocyclic ring comprising 3 to 11 carbon atoms and one or more heteroatoms selected from O, S and N, wherein the carbocyclic or heterocyclic ring can be substituted with C 1-12 alkyl or alkoxy; C substituted by a carbocycle comprising 5 to 12 carbon atoms or a heterocycle comprising 3 to 11 carbon atoms and one or more heteroatoms selected from O, S and N 1-6 alkyl, wherein the carbocycle or heterocycle can be substituted by one or more C 1-12 alkyl or alkoxy; C ions interrupted by one or more -O-, carbonyl or carbonyl groups and / or substituted with OH 6-18 Alkyl; or C interrupted by one or more -O-, carbonyl or carbonyloxy and substituted by OH, a carbocycle comprising 5 to 12 carbon atoms or a heterocycle comprising 3 to 11 carbon atoms and one or more heteroatoms selected from the group consisting of O, S and N 6-18 alkyl, wherein the carbocycle or heterocycle can be substituted by C 1-12 alkyl or alkoxy; and (b) a fatty acid alkanolamide of Formula IV wherein n is 1 or 2; when n is 1, m is 1; when n is 2, m is 0, R 1 is H or C 1-12 alkyl, G is H or C 1-6 alkyl, and R 2 selected from C 7-23 alkyl or alkenyl; wherein the weight ratio of citrate ester component (a) to fatty acid alkanolamide component (b) is 2: 1 to 1:

8.

6. The anti-wear additive composition of any of the preceding claims, wherein the fatty acid alkanolamide is a compound of Formula V: wherein R 1 is H or C 1-12 alkyl, and R 2 is selected from C 7-23 alkyl or alkenyl.

7. The anti-wear additive composition of claim 6, wherein R 1 selected from C 1-4 alkyl.

8. The anti-wear additive composition of claim 7, wherein R 1 is methyl.

9. The anti-wear additive composition of claim 6, wherein the fatty acid alkanolamide is a mixture of compounds of Formula V, wherein about 15% to about 45% by weight of the fatty acid alkylol amide is wherein R 2 is C 15 alkyl or alkenyl, about 40% to about 80% by weight of the fatty acid alkylol amide is wherein R 2 is C 17 alkyl or alkenyl, and from about 0 to about 15% by weight of the fatty acid alkylol amide is a compound wherein R 2 is C 7-14 , C 16 or C 18-19 alkyl or alkenyl.

10. The anti-wear additive composition of claim 6, wherein the fatty acid alkanolamide is prepared by reacting a di(hydroxyalkyl)amine with a carboxylic acid or carboxylic acid derivative from rapeseed oil, corn oil, coconut oil, sunflower oil, soybean oil, lard, palm oil, tallow, cocoa butter, or illipe butter.

11. The anti-wear additive composition of claim 10, wherein the di(hydroxyalkyl)amine is bis(2-hydroxypropyl)amine.

12. The anti-wear additive composition of claim 11, wherein the fatty acid alkanolamide is prepared by reacting bis(2-hydroxypropyl)amine with a methyl ester derived from tallow carboxylic acid.

13. A lubricant composition comprising: A) a lubricating oil, B) 0.1 to 5 wt%, based on the weight of the lubricant composition, of a citrate ester compound of Formula II or a citrate ester compound of Formula III or a mixture of citrate ester compounds of Formula II and Formula III, wherein: n is 1 to 20; R is C 1-18 alkyl; C substituted by a carbocycle comprising 5 to 12 carbon atoms or a heterocycle comprising 3 to 11 carbon atoms and one or more heteroatoms selected from O, S and N 1-18 alkyl, wherein the carbocycle or heterocycle can be substituted by one or more C 1-12 alkyl or alkoxy; C ions interrupted by one or more -O-, carbonyl, carbonyloxy groups and / or substituted by OH 2-18 alkyl; C interrupted by one or more -O-, carbonyl or carbonyloxy and substituted by a carbocycle containing 5 to 12 carbon atoms or a heterocycle containing 3 to 11 carbon atoms and one or more heteroatoms selected from the group consisting of O, S and N 2-18 alkyl, wherein the carbocycle or heterocycle can be substituted by C 1-12 alkyl or alkoxy; or carbocycle comprising 5 to 12 carbon atoms or a heterocycle comprising 3 to 11 carbon atoms and one or more heteroatoms selected from the group consisting of O, S and N, wherein the carbocycle or heterocycle can be substituted by C 1-12 alkyl or alkoxy; and R' is C 2-18 alkylene; C interrupted by one or more -O-, carbonyl or carbonyloxy and / or substituted by OH, a carbocycle comprising 5 to 12 carbon atoms or a heterocycle comprising 3 to 11 carbon atoms and one or more heteroatoms selected from the group consisting of O, S and N 2-18 alkylene, wherein the carbocycle or heterocycle can be substituted by C 1-12 alkyl or alkoxy; or said alkylene, interrupted alkylene or substituted alkylene interrupted by a carbocyclic ring comprising 5 to 12 carbon atoms or a heterocyclic ring comprising 3 to 11 carbon atoms and one or more heteroatoms selected from the group consisting of O, S and N, wherein the carbocyclic or heterocyclic ring can be substituted by C 1-12 alkyl or alkoxy; wherein each R and each R' can be the same or different from any other R or R'; and C) 0.1 to 5 wt%, based on the weight of the lubricant composition, of a fatty acid alkanolamide of Formula IV wherein n is 1 or 2; when n is 1, m is 1; when n is 2, m is 0, R 1 is H or C 1-12 alkyl, G is H or C 1-6 alkyl, and R 2 selected from C 7-23 alkyl or alkenyl, and wherein the weight ratio of citrate ester component B) to fatty acid alkanolamide component C) is 2: 1 to 1:

8.

14. The lubricant composition of claim 13, wherein the composition comprises more than one citrate ester compound of Formula III that differs by having different n values.

15. The lubricant composition of claim 13, further comprising a citrate ester compound of Formula I wherein R is described for Formula II and III, and the wt% of all citrate ester compounds of Formula I, II, and III combined is 0.1 to 5 wt% based on the weight of the lubricant composition.

16. The lubricant composition of claim 15, wherein the composition comprises at least one citrate ester compound of Formula I, at least one citrate ester compound of Formula II, and at least one citrate ester compound of Formula III, wherein n is 1 to 5; R is C 1-12 alkyl or C 2-12 alkyl interrupted by one or more -O-, and R' is C 2-12 alkylene or said alkylene interrupted by one or more -O-.

17. A lubricant composition comprising: A) a lubricating oil, B) 0.1 to 5 wt% of a citrate ester compound of Formula I wherein R is a carbocyclic ring comprising 5 to 12 carbon atoms or a heterocyclic ring comprising 3 to 11 carbon atoms and one or more heteroatoms selected from O, S and N, wherein the carbocyclic or heterocyclic ring can be substituted with C 1-12 alkyl or alkoxy; C substituted by a carbocycle comprising 5 to 12 carbon atoms or a heterocycle comprising 3 to 11 carbon atoms and one or more heteroatoms selected from O, S and N 1-6 alkyl, wherein the carbocycle or heterocycle can be substituted by one or more C 1-12 alkyl or alkoxy; C ions interrupted by one or more -O-, carbonyl or carbonyl groups and / or substituted with OH 6-18 Alkyl; or C interrupted by one or more -O-, carbonyl or carbonyloxy and substituted by OH, a carbocycle comprising 5 to 12 carbon atoms or a heterocycle comprising 3 to 11 carbon atoms and one or more heteroatoms selected from the group consisting of O, S and N 6-18 alkyl, wherein the carbocycle or heterocycle can be substituted by C 1-12 alkyl or alkoxy; and C) 0.1 to 5 wt% of a fatty acid alkanolamide of Formula IV wherein n is 1 or 2; when n is 1, m is 1; when n is 2, m is 0, R 1 is H or C 1-12 alkyl, G is H or C 1-6 alkyl, and R 2 selected from C 7-23 alkyl or alkenyl, and wherein the weight ratio of citrate ester component B) to fatty acid alkanolamide component C) is 2: 1 to 1:

8.

18. The lubricant composition of any one of claims 13 to 17, wherein the fatty acid alkanolamide is a compound of Formula V: wherein R 1 is H or C 1-12 alkyl, and R 2 is selected from C 7-23 alkyl or alkenyl.

19. The lubricant composition of claim 18, wherein R 1 is selected from C 1-4 alkyl.

20. The lubricant composition of claim 19, wherein R 1 is methyl.

21. The lubricant composition of claim 18, wherein the fatty acid alkanolamide is a mixture of compounds of Formula V, wherein about 15% to about 45% by weight of the fatty acid alkylol amide is wherein R 2 is C 15 alkyl or alkenyl, about 40% to about 80% by weight of the fatty acid alkylol amide is where R 2 is C 17 alkyl or alkenyl, and from about 0 to about 15% by weight of the fatty acid alkylol amide is a compound wherein R 2 is C 7-14 , C 16 or C 18-19 alkyl or alkenyl.

22. The lubricant composition of claim 18, wherein the fatty acid alkanolamide is prepared by reacting a di(hydroxyalkyl)amine with a carboxylic acid or carboxylic acid derivative from rapeseed oil, corn oil, coconut oil, sunflower oil, soybean oil, lard, palm oil, tallow, cocoa butter, or illipe butter.

23. The lubricant composition of claim 22, wherein the di(hydroxyalkyl)amine is bis(2-hydroxypropyl)amine.

24. The lubricant composition of claim 23, wherein the fatty acid alkanolamide is prepared by reacting bis(2-hydroxypropyl)amine with a methyl ester derived from tallow carboxylic acid.

25. The lubricant composition of any one of claims 13 to 24, further comprising D) zinc dialkyldithiophosphate (ZDDP).

26. The lubricant composition of claim 25, wherein the weight ratio of citrate ester component B) to ZDDP component D) is 4: 1 to 1:

4.

27. The lubricant composition of any one of claims 13 to 26, wherein the lubricating oil is present in the lubricant composition at about 80 wt% or more based on the total weight of the lubricant composition.

28. The lubricant composition of claim 27, further comprising one or more additional additives selected from the group consisting of dispersants, detergents, corrosion / rust inhibitors, antioxidants, antiwear agents, defoamers, friction modifiers, seal swell agents, demulsifiers, V.I. improvers, and pour point depressants.

Images