KR20100019539A - Lubricating composition containing ashfree antiwear agent based on hydroxypolycarboxylic acid derivative and a molybdenum compound - Google Patents

Abstract

The invention provides a lubricating composition containing an oil of lubricating viscosity, an oil soluble molybdenum compound, and an ashless antiwear agent. The invention further provides for a new antioxidant. The lubricating composition is suitable for lubricating an internal combustion engine.

Description

Lubrication composition containing ash-free antiwear agent based on hydroxypolycarboxylic acid derivative and molybdenum compound

The present invention provides a lubricating composition containing an oil of lubricating viscosity, an oil soluble molybdenum compound and an ashless antiwear agent. The present invention also provides new antioxidants. The lubricating composition is suitable for lubricating internal combustion engines.

Engine manufacturers are focusing on improving engine design to improve fuel economy and fuel efficiency (typically based on CAFE standards). While improvements in engine design and operation contribute, improvements in the formulation of engine oil lubricants can also improve fuel economy and fuel efficiency. Lubricants work to reduce and disperse engine deposits that build up when the engine is running. It also acts to reduce the friction between sliding movable parts (generally metallic or ceramic parts) in contact.

Lubricants are well known to contain a number of additives (eg, antiwear agents, antioxidants, dispersants, detergents, etc.) used to protect machinery such as internal combustion engines from wear, oxidation, soot deposits and acidity buildup. A common antiwear additive for engine lubricants is zinc dialkyldithiophosphate (ZDDP). ZDDP antiwear additives are thought to protect the engine by forming a protective film on the metal surface. ZDDP is also thought to have a detrimental effect on fuel economy and fuel efficiency. In conclusion, it contains additional friction modifiers to prevent the harmful effects of ZDDP on fuel economy and fuel efficiency. Both ZDDP and friction modifiers function by adsorbing on the surface of the slide and can interfere with each other's respective functions.

In addition, engine lubricants containing phosphorus compounds and sulfur have been found to partially contribute to particulate emissions, and other pollutant emissions. In addition, sulfur and phosphorus tend to poison the catalyst used in the catalytic converter, reducing the performance of the catalyst.

As emissions are increased (often related to NO _x formation, SO _x formation, sulfated ash formation and reducing the efficiency of the aftertreatment catalytic converter), sulfur, phosphorus and sulfated ash There is an urgent need to reduce the content. However, decreasing the level of antiwear additives such as ZDDP can increase wear and lead to other detrimental performance of the engine.

In addition, as technology advances, components of the engine are exposed to more stringent operating conditions. Operating conditions may include high power density engines, the use of turbo chargers, the use of alternative fuels and similar conditions thereof. Under many stringent operating conditions, oxidation of lubricants and components occurs more easily. Thus, a reduction in oxidation is required, and consequently also can increase device life or reliability.

International Publication No. WO 2005/087904 discloses a lubricant composition containing at least one hydroxycarboxylic acid ester or hydroxy polycarboxylic acid. This lubricant composition may further comprise zinc dihydrocarbyldithiophosphate or other phosphorus-containing additives such as trilauryl phosphate or triphenylphosphorothionate. This lubricant composition exhibits abrasion resistance or fatigue resistance.

International Publication No. WO 2006/044411 discloses low sulfur, low phosphorus, low ash lubricant compositions suitable for lubricating internal combustion engines containing tartrate esters or amides having 1 to 150 carbon atoms per ester of amide groups. .

US Patent 5,338,470 discloses alkylated citric acid derivatives obtained as reaction products of citric acid and alkyl alcohols or amines. Such alkylated citric acid derivatives are effective as antiwear and friction modifiers.

U.S. Patent 4,237,022 discloses tartrimide useful as an additive in fuels and lubricants for improved fuel economy as well as effective reduction of squeaks and friction.

U.S. Patent 4,952,328 is a lubricating oil composition for an internal combustion engine, comprising (A) a lubricity viscosity oil, (B) a carboxyl derivative produced by reacting a specific amine with a succinic acylating agent, and (C) a basic alkali metal salt of sulfonic acid or carboxylic acid. Disclosed is a composition.

U.S. Patent 4,326,972 discloses a lubricant composition for improving fuel economy of an internal combustion engine. This composition includes specific sulfided compositions (based on esters of carboxylic acids) and basic alkali metal sulfonates.

US patent application 60/867534 discloses malonate esters suitable as antiwear agents.

Canadian patent CA 1 183 125 discloses lubricants for gasoline engines containing alkyl-ester tartrates having at least eight total carbon atoms of alkyl groups.

In conclusion, the lubricating composition is characterized by (i) reducing or preventing phosphorus emissions, (ii) reducing or preventing sulfur emissions, (ii) complete or partial replacement of ZDDP of lubricant, (iii) improved fuel economy, (iv) fuel economy maintenance / There is a need for provision of a lubricating composition that can provide at least one of efficiency, and (v) oxidation control. The present invention provides an antiwear agent capable of achieving at least one of the above (i), (ii), (iii), (iv) and (v). It may also be desirable for the antiwear agent to have no deleterious effect on other components of the mechanical device. It may also be desirable for the antiwear agent to have antioxidant performance.

Summary of the Invention

In one aspect, the present invention provides a lubricating composition comprising an oil of lubricating viscosity, an oil soluble molybdenum compound, and an ashless antiwear agent represented by the following formula (1):

In this expression,

Y and Y 'are independently -O-,>NH,> NR ³ or an imide group made by taking together the Y and Y' groups and forming a R ¹ -N <group between two> C═O groups;

X is independently -ZO-Z'-,> CH ₂ ,> CHR ⁴ ,> CR ⁴ R ⁵ ,> C (OH) (CO ₂ R ² ),> C (CO ₂ R ² ) ₂ ,> CCH ₂ CO ₂ R ² or> CHOR ⁶ ;

Z and Z 'are independently> CH ₂ ,> CHR ⁴ ,> CR ⁴ R ⁵ ,> C (OH) (CO ₂ R ² ) or> CHOR ⁶ ;

n is 0 to 10 or 1 to 8, or 1 to 6, or 2 to 6, or 2 to 4, provided that when n = 1, X is not> CH ₂ , and when n = 2, two X ′ Is not> CH ₂ at the same time;

m is 0 or 1;

R ¹ is independently hydrogen or a hydrocarbyl group containing generally 1 to 150, 4 to 30, 6 to 20, 10 to 20, 11 to 18 or 8 to 10 carbon atoms Provided that when R ¹ is hydrogen m is 0 and n is 1 or more;

R ² is generally a hydrocarbyl group containing 1 to 150, 4 to 30, 6 to 20, 10 to 20, 11 to 18 or 8 to 10 carbon atoms;

R ³ , R ⁴ and R ⁵ are independently hydrocarbyl groups or hydroxy containing hydrocarbyl groups or carboxy containing hydrocarbyl groups;

R ⁶ is hydrogen or a hydrocarbyl group which generally contains 1 to 150 or 4 to 30 carbon atoms.

In one embodiment, the lubricating composition is characterized by at least one of (i) sulfur content of 0.8 wt% or less, (ii) phosphorus content of 0.2 wt% or less, or (iii) sulfated ash content of 2 wt% or less.

In one embodiment, the lubricating composition of the present invention is characterized by (i) up to 0.5 wt% sulfur content, (ii) up to 0.1 wt% phosphorus content and (iii) up to 1.5 wt% sulfated ash content.

In one aspect, the present invention provides a method for lubricating an internal combustion engine, comprising supplying the lubricating composition disclosed herein to an internal combustion engine.

In one aspect, the present invention provides an apparatus for (i) reducing or preventing phosphorus emissions, (ii) reducing or preventing sulfur emissions, (ii) complete or partial replacement of ZDDP of lubricant, (iii) improved fuel economy, and (iv) fuel economy maintenance. Provides the use of the lubricating composition disclosed herein, which is used to provide at least one of / efficiencies.

In one aspect, the present invention provides the use of a compound which can be represented by the following formula (1) used as an antioxidant in a lubricant:

[Formula 1]

In this expression,

Y and Y 'are independently -O-,>NH,> NR ³ or an imide group made by taking together the Y and Y' groups and forming a R ¹ -N <group between two> C═O groups;

X is independently -ZO-Z'-,> CH ₂ ,> CHR ⁴ ,> CR ⁴ R ⁵ ,> C (OH) (CO ₂ R ² ),> C (CO ₂ R ² ) ₂ or> CHOR ⁶ Is;

Z and Z 'are independently> CH ₂ ,> CHR ⁴ ,> CR ⁴ R ⁵ ,> C (OH) (CO ₂ R ² ) or> CHOR ⁶ ;

n is 0 to 10 or 1 to 8, or 1 to 6, or 2 to 6, or 2 to 4, provided that when n = 1, X is not> CH ₂ , and when n = 2, two X ′ Is not> CH ₂ at the same time;

m is 0 or 1;

R ¹ is independently hydrogen or a hydrocarbyl group containing generally 1 to 150, 4 to 30, 6 to 20, 10 to 20, 11 to 18 or 8 to 10 carbon atoms, Provided that when R ¹ is hydrogen m is 0 and n is at least 1;

R ² is generally a hydrocarbyl group containing 1 to 150, 4 to 30, 6 to 20, 10 to 20, 11 to 18 or 8 to 10 carbon atoms;

R ³ , R ⁴ and R ⁵ are independently hydrocarbyl groups;

R ⁶ is hydrogen or a hydrocarbyl group which generally contains 1 to 150 or 4 to 30 carbon atoms.

In one embodiment, the present invention provides the use of a compound of formula 1 as an antioxidant in a lubricant wherein the compound of formula 1 is an ester (eg, a monoester, diester or triester).

In one aspect, the present invention provides the use of a compound of formula 1, wherein the compound of formula 1 is used as an antioxidant in a lubricant, not citrate.

In one aspect, the present invention provides the use of tartaric acid derivatives (typically tartrate esters) for use as antioxidants in lubricants.

In one aspect, the present invention provides the use of a compound of formula 1 (typically a tartaric acid derivative) for use as an antioxidant in internal combustion engine lubricants.

The present invention provides a lubricating composition and a method for lubricating an engine as described above.

Oil Soluble Molybdenum Compounds

The oil soluble molybdenum compound may have the functional performance of the antiwear agent, the antioxidant, the friction modifier, or a mixture thereof. Typically, oil soluble molybdenum compounds include molybdenum dithiocarbamate, molybdenum dialkyldithiophosphate, amine salts of molybdenum compounds, molybdenum xanthate, molybdenum sulfide, molybdenum carboxylate, molybdenum alkoxide or mixtures thereof. Molybdenum sulfides include molybdenum disulfides. Molybdenum disulfide may be in the form of a stable dispersion. In one embodiment, the oil soluble molybdenum compound may be selected from the group consisting of molybdenum dithiocarbamate, molybdenum dialkyldithiophosphate, amine salts of molybdenum compounds, and mixtures thereof. In one embodiment, the oil soluble molybdenum compound is molybdenum dithiocarbamate.

Suitable examples of molybdenum dithiocarbamates that can be used as antioxidants include the trade names Molyvan 822 ™ and Molyvan ™ A and Asahi Denka Kogyo Co., Ltd., from RVanderbilt Co., Ltd. Commercially available products sold under the trade names Adeka Sakura-Lube ™ S-100, S-165, S-515 and S-600 and mixtures thereof.

The oil soluble molybdenum compound may be present in an amount sufficient to provide 0.5 ppm to 2000 ppm, 1 ppm to 700 ppm, 1 ppm to 550 ppm, 5 ppm to 300 ppm or 20 ppm to 250 ppm of molybdenum.

Ashless antiwear

In one embodiment, the compound of formula 1 is an ashless antiwear agent and may also act as an antioxidant.

In one embodiment, the compound of formula 1 contains an imide group. Imide groups are generally prepared by taking the Y and Y 'groups together and forming a R ¹ -N <group between two> C═O groups.

In one embodiment, the compound of formula 1 is such that m, n, X and R ¹ , R ² and R ⁶ are defined as follows: m is 0 or 1, n is 1 to 2, X is> CHOR ⁶ , R ¹ , R ² and R ⁶ are independently hydrocarbyl groups containing 4 to 30 carbon atoms.

In one embodiment, both Y and Y 'are -O-.

In one embodiment, the compound of Formula 1 is m, n, X, Y, Y 'and R ¹ , R ² and R ⁶ are defined as follows: m is 0 or 1, n is 1 to 2, X is > CHOR ⁶ , Y and Y 'are both -O- and R ¹ , R ² and R ⁶ are independently a hydrocarbyl group containing 4 to 30 carbon atoms or hydrogen.

In one embodiment, the ashless antiwear agent includes an imide, diester, di-amide, di-imide, ester-amide, ester-imide or imide-amide. In one embodiment, the antiwear agent comprises an imide, di-ester, di-amide or ester-amide.

Diesters, di-amides, ester-amides, ester-imide compounds of formula (1) may be prepared by reacting a dicarboxylic acid (e.g. tartaric acid) with an amine or an alcohol, optionally in the presence of a known esterification catalyst. Can be. In the case of ester-imide compounds, there must be at least three carboxylic acid groups (eg, citric acid). In the case of di-imide, the carboxylic acid groups should be at least four. Amines or alcohols generally have sufficient carbon atoms to meet the conditions of R ¹ and / or R ² as described in the definition of formula (1).

In one embodiment, R ¹ and R ² are independently linear or branched hydrocarbyl groups. In one embodiment, the hydrocarbyl group is branched. In one embodiment, the hydrocarbyl group is linear. R ¹ and R ² may be incorporated into Formula 1 by amine or alcohol. Alcohols include both monohydric alcohols and polyhydric alcohols. The carbon atoms of the alcohol may be linear chains, branched chains or mixtures thereof.

Examples of suitable branched alcohols include 2-ethylhexanol, isotridecanol, Guerbet alcohol or mixtures thereof.

Examples of monohydric alcohols include methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol, pentadecanol, Hexadecanol, heptadecanol, octadecanol, nonadecanol, eicosanol or mixtures thereof. In one embodiment the monohydric alcohol contains 5 to 20 carbon atoms.

Alcohols include monohydric alcohols or polyhydric alcohols. Examples of suitable polyhydric alcohols include ethylene glycol, propylene glycol, 1,3-butylene glycol, 2,3-butylene glycol, 1,5-pentane diol, 1,6-hexane diol, glycerol, sorbitol, pentaerythritol, Trimethylolpropane, starch, glucose, sucrose, methylglucoside or mixtures thereof. In one embodiment, polyhydric alcohols are used in a mixture with monohydric alcohols. Generally, the monohydric alcohols in such mixtures constitute at least 60 mol%, or at least 90 mol% of the mixture.

In one embodiment, the ashless antiwear agent is derived from tartaric acid. Tartaric acid used to prepare the tartrate of the present invention is commercially available, which is often one or more isomers such as d-tartaric acid, l-tartaric acid or mesotartaric acid, depending on the source (natural) or synthetic method (from maleic acid). It is possible to exist in the form. For example, a racemic mixture of d-tartaric acid and l-tartaric acid is obtained from the catalytic oxidation of hydrogen peroxide with maleic acid (in the presence of a tungstic acid catalyst). Such derivatives may also be prepared from functional equivalents to diacids, such as esters, acid chlorides or anhydrides, which are apparent to those skilled in the art.

When the compound of formula 1 is derived from tartaric acid, the tartrate obtained can be solid, semisolid or oil depending on the particular alcohol used for the preparation of tartrate. The tartrate used as an additive in the lubricating composition is advantageously soluble and / or stable dispersible in such oily compositions. For example, a composition designed for use in oils is generally oil soluble and / or stable dispersible in the oil in which it is used. The term "oil solubility", as used in this specification and in the claims that follow, does not necessarily mean that the entire composition in question is miscible or soluble in total proportion to the total oil. Rather, it should be considered to mean that the solution is soluble in oils (inorganic oils, synthetic oils, etc.) intended to function so that the solution can exhibit one or more of the necessary properties. Similarly, the "solution" need not necessarily be a true solution in the strict physical or chemical sense. Instead, it may be a microemulsion or colloidal dispersion which exhibits properties that are sufficiently similar to a true solution for the purposes of the present invention so that it can be exchanged with the solution for practical purposes in the context of the present invention.

In one embodiment, the ashless antiwear agent comprises a compound derived from hydroxycarboxylic acid. In one embodiment, the ashless antiwear agent is a hydroxy-polycarboxylic acid di-ester, hydroxy-polycarboxylic acid di-amide, hydroxy-polycarboxylic acid di-imide, hydroxy-polycarboxylic acid ester-amide, hydroxy-polycarboxylic acid Derived from at least one of ester-imide and hydroxy-polycarboxylic acid imide-amide. In one embodiment, the ashless antiwear agent is derived from at least one of the group consisting of hydroxy-polycarboxylic acid di-esters, hydroxy-polycarboxylic acid di-amides and hydroxy-polycarboxylic acid ester-amides.

Examples of suitable hydroxycarboxylic acids include citric acid, tartaric acid, lactic acid, glycolic acid, hydroxy-propionic acid, hydroxyglutaric acid or mixtures thereof. In one embodiment, the ashless antiwear agent is derived from tartaric acid, citric acid, hydroxy-succinic acid, dihydroxy monoacid, mono-hydroxy diacid or mixtures thereof. In one embodiment, the ashless antiwear agent comprises a compound derived from tartaric acid or citric acid. In one embodiment, the ashless antiwear agent comprises a compound derived from tartaric acid. In one embodiment, the compound of formula 1 is not citrate.

US patent application 2005/198894 discloses suitable hydroxycarboxylic acid compounds and methods for their preparation.

Canadian Patent 1183125; US Patent Publication Nos. 2006/0183647 and US-2006-0079413; US Patent Application No. 60/867402; And British Patent 2 105 743 A all disclose examples of suitable tartaric acid derivatives.

In one embodiment, the di-ester, di-amide, di-imide, ester-amide, ester-imide, imide-amide compound is derived from a compound of formula (1). In one embodiment, the di-ester, di-amide, ester-amide compound is derived from a compound of formula (1).

A detailed description (by the reaction of primary amines and tartaric acid) of the preparation of suitable tartrimides is disclosed in US Pat. No. 4,237,022.

In one embodiment, the ashless antiwear agent includes an imide, di-ester, di-amide, ester-amide derivative of tartaric acid.

Examples of suitable citric acid derivatives include trialkyl citrate or borate trialkyl citrate. Suitable examples include triethyl citrate, ethyl pentyl citrate-containing tripentyl citrate, borate triethyl citrate, tributyl citrate, triethyl citrate transesterified with 1,2-propanediol, triethyl O-acetyl citrate, triethyl Citrate octadecyl succinate or mixtures thereof. Further details of suitable citrates are disclosed in WO 2005/087904 and US Pat. No. 5,338,470. Other suitable citrates include 2-ethylhexyl citrate, dodecyl citrate or mixtures thereof.

Ashless antiwear agents, generally tartrates, of the present invention may also act as rust and corrosion inhibitors, friction modifiers, antiwear agents and demulsifiers.

In one embodiment, the ashless antiwear agent is not borated.

The ashless antiwear agent of the present invention may be present at 0.01 wt% to 20 wt% or 0.05 to 10 wt% or 0.1 to 5 wt% of the lubricating composition.

Oil of lubricity viscosity

The lubricating composition comprises an oil of lubricity viscosity. Such oils include natural and synthetic oils, oils from hydrocracking, hydrogenation and hydrofinishing, crude, refined and refined oils and mixtures thereof.

Crude oils are generally obtained directly from natural or synthetic sources with no (or little) further purification.

Refined oils are similar to crude oils, except that they are further treated with one or more purification steps to improve one or more properties. Purification techniques are known in the art and include solvent extraction, secondary distillation, acid or base extraction, filtration, percolation, and the like.

Refined oils, also known as regenerated oils or reprocessed oils, are obtained in a manner similar to the method used to obtain refined oils and further processed by techniques for removal of consumed additives and oil decay products.

Natural oils useful in the preparation of the lubricants of the present invention include animal oils, vegetable oils (eg castor oil), inorganic lubricating oils such as liquid petroleum oils and solvent treated or acid treated paraffinic, naphthenic or mixed paraffinic-naphthenic based Inorganic lubricants, and oils derived from coal or shale or mixtures thereof.

Synthetic lubricating oils are useful and include hydrocarbon oils such as: polymerized, prepolymerized or interpolymerized olefins (eg polybutylene, polypropylene, propyleneisobutylene copolymers); Poly (1-hexene), poly (1-octene), 1-decene trimers or oligomers, such as poly (1-decene) (such materials are often called poly α-olefins) and mixtures thereof; Alkyl-benzenes (eg dodecylbenzene, tetradecylbenzene, dinonylbenzene, di- (2-ethylhexyl) -benzene); Polyphenyls (eg, biphenyls, terphenyls, alkylated polyphenyls); Diphenyl alkanes, alkylated diphenyl alkanes, alkylated diphenyl ethers and alkylated diphenyl sulfides and derivatives, analogs and homologs thereof, or mixtures thereof.

Other synthetic lubricants include polyol esters (e.g. Prolube® 3970), diesters, liquid esters of phosphorus-containing acids (e.g. diethyl esters of tricresyl phosphate, trioctyl phosphate and decane phosphonic acid) or polymeric tetrahydro Furan is included. Synthetic oils may be produced in a Fischer-Tropsch reaction and may generally be hydroisomerized Fischer-Tropsch hydrocarbons or waxes. In one aspect, the oil can be oil and other gas-liquid oils prepared by the Fischer-Tropsch gas-liquid synthesis procedure.

Lubricant viscosity oils may also be defined as specified in the American Petroleum Institute (API) Base Oil Compatibility Guidelines. The five base oil groups are as follows: group I (sulfur content> 0.03 wt%, and / or <90 wt% saturates, viscosity index 80-120); Group II (sulfur content ≦ 0.03 wt% and ≧ 90 wt% saturates, viscosity index 80-120); Group III (sulfur content ≦ 0.03 wt%, and saturates ≧ 90 wt%, viscosity index ≧ 120); Group IV (all polyalphaolefins (PAO)); And group V (other total not included in group I, II, III or IV). Oils of lubricity viscosity include oils of API group I, group II, group III, group IV, group V or mixtures thereof. Often oils of lubricious viscous are API Group I, Group II, Group III, Group IV oils or mixtures thereof. Alternatively, oils of lubricity viscosity are often API Group II, Group III or Group IV oils or mixtures thereof.

The amount of lubricious viscosity oil present is generally the remaining amount after 100 wt% minus the total amount of ash antiwear agent, oil soluble molvedin compound and other performance additives.

The lubricating composition may be in the form of a concentrate and / or a fully formulated lubricant. If the lubricating composition of the present invention (including (i) ashless antiwear agent and (ii) oil soluble molybdenum compound) is in the form of a concentrate (in which the additional oil can be formulated in whole or in part to make the final lubricant), The ratio of the component of the invention to the oil of lubricity viscosity and / or the ratio of the component of the invention to the diluent oil may range from 1:99 to 99: 1 (by weight), or from 80:20 to 10:90 (by weight). Include.

Other performance additives

The composition optionally includes other performance additives. Other performance additives include metal deactivators, viscosity modifiers, cleaning agents, friction modifiers (in addition to oil soluble molybdenum compounds or compounds of formula 1), antiwear agents (in addition to ashless antiwear agents of the present invention), corrosion inhibitors, dispersants, dispersant viscosity modifiers, extreme pressure agents , Antioxidants (in addition to the oil soluble molybdenum compounds of the present invention), foam inhibitors, demulsifiers, pour point depressants and seal swelling agents, and mixtures thereof. Generally a fully formulated lubricant will comprise one or more of these performance additives.

In one embodiment, the lubricating composition comprises ashless antiwear agent and further comprises at least one of a viscosity modifier, an antioxidant, an overbased detergent, a succinimide dispersant or a mixture thereof.

In one embodiment, the lubricating composition containing ashless antiwear agent further comprises a phosphorus containing antiwear agent.

Freshener

The lubricating composition optionally further comprises other known neutral or overbased detergents. Suitable detergent substrates include phenates, sulfur containing phenates, sulfonates, salicylates, silicates, carboxylic acids, phosphoric acids, mono and / or di-thiophosphoric acids, alkyl phenols, sulfur coupled alkyl phenol compounds or salinine This includes. Various overbased detergents and methods for their preparation are described in more detail in numerous patent publications such as WO2004 / 096957 and references cited therein. Detergent substrates are generally salted with metals such as calcium, magnesium, potassium, sodium or mixtures thereof. In one embodiment, the lubricating composition further comprises an overbased detergent. Generally overbased detergents include phenates, sulfur containing phenates, sulfonates, salixates, salicylates or mixtures thereof.

The detergent may be present at 0 wt% to 10 wt%, or 0.1 wt% to 8 wt% or 1 wt% to 4 wt% or more than 4 to 8 wt%.

Dispersant

Dispersants are often known as ashless dispersants because they do not contain ash forming metal prior to mixing in the lubricating oil composition and generally do not contribute to any ash forming metal when added to the lubricant and polymeric dispersant. Ashless dispersants are characterized by polar groups attached to relatively high molecular weight hydrocarbon chains. Typical ashless dispersants include N-substituted long chain alkenyl succinimides. Examples of N-substituted long chain alkenyl succinimides include polyisobutylene succinimide having a number average molecular weight of the polyisobutylene substituent in the range of 350 to 5000, or 500 to 3000. Succinimide dispersants and their preparation are disclosed in US Pat. No. 3,172,892 or US Pat. No. 4,234,435 or EP 0355895 and the like. Succinimide dispersants are generally imides formed from polyamines, typically poly (ethyleneamine).

In one embodiment, the invention further comprises at least one polyisobutylene succinimide dispersant derived from polyisobutylene having a number average molecular weight in the range of 350 to 5000, or 500 to 3000. Polyisobutylene succinimide may be used alone or in combination with other dispersants.

In one aspect, the invention further comprises at least one dispersant derived from polyisobutylene succinic anhydride, amines and zinc oxide to form zinc and polyisobutylene succinimide complexes. Polyisobutylene succinimide zinc complexes may be used alone or in mixtures.

Another class of ashless dispersant is the Mannich base. Mannich dispersants are reaction products of aldehydes (especially formaldehyde) and amines (especially polyalkylene polyamines) with alkyl phenols. Alkyl groups generally contain at least 30 carbon atoms.

Dispersants may also be worked up according to conventional methods through reaction with a variety of optional agents. Among these are boron, urea, thiourea, dimercaptothiadiazole, carbon disulfide, aldehydes, ketones, carboxylic acids, hydrocarbon-substituted succinic anhydrides, maleic anhydrides, nitriles, epoxides and phosphorus compounds.

The dispersant may be present at 0 wt% to 20 wt%, or 0.1 wt% to 15 wt%, or 0.1 wt% to 10 wt%, or 1 wt% to 6 wt%, or 7 wt% to 12 wt%.

Antioxidant

Antioxidant compounds are known and include, for example, sulfided olefins (generally sulfided 4-carbobutoxy cyclohexene or triphenylphosphite equivalents or olefin sulfides), alkylated diphenylamines (e.g. nonyl diphenylamine , Typically di-nonyl diphenylamine, octyl diphenylamine, di-octyl diphenylamine), hindered phenols, or mixtures thereof. Antioxidant compounds may be used alone or in mixtures. Antioxidants may be present in the range of 0 wt% to 20 wt%, 0.1 wt% to 10 wt%, or 1 wt% to 5 wt% of the lubricating composition.

Hindered phenolic antioxidants often contain secondary butyl and / or tertiary butyl groups as steric hinders. Phenolic groups are often further substituted with bridging groups bound to hydrocarbyl groups and / or secondary aromatic groups. Examples of suitable hindered phenol antioxidants include 2,6-di-tert-butylphenol, 4-methyl-2,6-di-tert-butylphenol, 4-ethyl-2,6-di-tert-butylphenol, 4-propyl-2,6-di-tert-butylphenol or 4-butyl-2,6-di-tert-butylphenol or 4-dodecyl-2,6-di-tert-butylphenol. In one embodiment, the hindered phenolic antioxidant is an ester, such as the Shiva product Irganox ™ L-135 or 2,6-di-tert-butylphenol and alkyl acrylates wherein the alkyl groups are from 1 to 18, 2 to 12, 2 To 8, 2 to 6 or 4 carbon atoms) may be included. Further details of suitable ester-containing hindered phenol antioxidant chemistries are given in US Pat. No. 6,559,105.

In one embodiment, the lubricant does not contain (or contain reduced amounts) phenolic antioxidants when the compound of Formula 1 is used. This embodiment may be useful because the compound of formula 1 may be used as part or all substitutes for phenolic antioxidants. It is believed that traces of impurity tris-tert-butyl phenol are formed and maintained in the final product during the preparation of the tertiary butyl phenol. Tris-tert-butyl phenol is known to accumulate in vivo and is highly enriched in precipitates. Thus, the use of Formula 1 compound as an antioxidant can reduce in vivo accumulation.

Viscosity modifier

Viscosity modifiers are hydrogenated copolymers of styrene-butadiene, ethylene-propylene copolymers, polyisobutenes, hydrogenated styrene-isoprene polymers, hydrogenated isoprene polymers, polymethacrylates, polyacrylates, polyalkyl styrenes, hydrogenated eggs Kenyl aryl conjugated diene copolymers, polyolefins, esters of maleic anhydride-styrene copolymers or esters of (alpha-olefin maleic anhydride) copolymers or mixtures thereof.

Dispersion viscosity modifiers (often called DVMs) include ethylene-propylene copolymers functionalized by the reaction product of functionalized polyolefins such as acylating agents (eg, maleic anhydride) and amines; Polymethacrylates functionalized with amines, or esterified maleic anhydride-styrene copolymers reacted with amines.

The total content of the viscosity modifier and / or the dispersion viscosity modifier may be 0 wt% to 20 wt%, 0.1 wt% to 15 wt%, or 0.1 wt% to 10 wt% of the lubricating composition.

Abrasion resistant

The lubricating composition optionally comprises at least one other antiwear agent in addition to the ashless antiwear agent of the present invention. Examples of suitable antiwear agents include phosphate esters, sulfided olefins, sulfur containing antiwear additives such as metal dihydrocarbyldithiophosphates (eg zinc dialkyldithiophosphates), thiocarbamate containing compounds such as thiocarbamates Esters, alkylene-coupled thiocarbamates, and bis (S-alkyldithiocarbamyl) disulfides.

Dithiocarbamate containing compounds can be prepared by reacting dithiocarbamate acid or salt with an unsaturated compound. Dithiocarbamate-containing compounds can also be prepared by simultaneously reacting amines, carbon disulfides and unsaturated compounds. In general, the reaction is carried out at a temperature of 25 to 125 ° C. U.S. Patents 4,758,362 and 4,997,969 describe dithiocarbamate compounds and methods for their preparation.

Examples of suitable olefins that may be sulfided to form sulfurized olefins are propylene, butylene, isobutylene, pentene, hexane, heptene, octane, nonene, decene, undecene, dodecene, undecyl, tridecene, tetra Decene, pentadecene, hexadecene, heptadecene, octadecene, octadecenene, nonadecene, eicosene or mixtures thereof. In one embodiment, hexadecene, heptadecene, octadecene, octadecenene, nonadecene, eicosene or mixtures thereof acl dimers, trimers and tetramers thereof are particularly useful olefins.

Other classes of sulfurized olefins include fatty acids and esters thereof. Fatty acids are often obtained from vegetable or animal oils and generally contain 4 to 22 carbon atoms. Examples of suitable fatty acids and esters thereof include triglycerides, oleic acid, linoleic acid, palmitoleic acid or mixtures thereof. Often fatty acids are obtained from lard oil, tallow, peanut oil, soybean oil, cottonseed oil, sunflower seed oil or mixtures thereof. In one embodiment, the fatty acids and / or esters are mixed with olefins such as α-olefins.

In alternative embodiments, ashless antiwear agents (also referred to as friction modifiers) may be monoesters of polyols and aliphatic carboxylic acids, often acids containing 12 to 24 carbon atoms. Often the monoesters of polyols and aliphatic carboxylic acids are from 5 to 95% by weight of the mixture, in other embodiments from 10 to 90% or from 20 to 85% or from 20 to 80% by weight of sunflower seed oil which may be present in ashless antiwear agents. And mixtures thereof. Aliphatic carboxylic acids (particularly monocarboxylic acids) which form esters are generally acids containing 12 to 24 or 14 to 20 carbon atoms. Examples of carboxylic acids include dodecanoic acid, stearic acid, lauric acid, behenic acid and oleic acid.

Polyols include diols, triols and alcohols having a plurality of alcoholic OH groups. Polyhydric alcohols include ethylene glycols such as di-, tri- and tetra-ethylene glycol; Propylene glycols such as di-, tri- and tetra-propylene glycols; Glycerol; Butanediol; Hexanediol; Sorbitol; Arabitol; Mannitol; Sucrose; Fructose; Glucose; Cyclohexane diol; Erythritol; And pentaerythritol, such as di- and tri-pentaerythritol. Often, the polyol is diethylene glycol, triethylene glycol, glycerol, sorbitol, pentaerythritol or dipentaerythritol. Commercially known glycerol monooleates are thought to comprise about 60 ± 5 wt% of the chemical species “glycerol monooleate”, 35 ± 5 wt% of glycerol dioleate and less than about 5 wt% of trioleate and oleic acid. The content of monoesters described below is that of commercial grade materials.

The antiwear agent may be present in a range comprising 0 wt% to 15 wt% or 0 wt% to 10 wt%, 0.05 wt% to 5 wt%, or 0.1 wt% to 3 wt% of the lubricating composition.

In one embodiment, the lubricating composition does not comprise zinc dihydrocarbyl dithiophosphate. In one embodiment, the lubricating composition further comprises zinc dihydrocarbyl dithiophosphate.

Extreme pressure

Extreme pressure (EP) agents which are soluble in oils include sulfur- and chlorosulfur-containing EP agents, chlorinated hydrocarbon EP agents and phosphorus EP agents. Examples of such EP agents include chlorinated waxes; Organic sulfides and polysulfides such as dibenzyldisulfide, bis- (chlorobenzyl) disulfide, dibutyl tetrasulfide, sulfided methyl esters of oleic acid, sulfided alkylphenols, sulfided dipentene, sulfided terpenes and sulfided diels- Elder adduct; Reaction products of phosphosulfated hydrocarbons such as phosphorus sulfide with terpentin or methyl oleate; Phosphorus esters such as dihydrocarbon and trihydrocarbon phosphites such as dibutyl phosphite, diheptyl phosphite, dicyclohexyl phosphite, pentylphenyl phosphite; Dipentylphenyl phosphite, tridecyl phosphite, distearyl phosphite and polypropylene substituted phenyl phosphite; Metal thiocarbamates such as zinc dioctyldithiocarbamate and barium heptylphenol diacid; Amine salts of alkyl and dialkylphosphoric acids, such as amine salts of reaction products of propylene oxide with dialkyldithiophosphoric acid; And mixtures thereof.

Friction modifier

In one embodiment, further comprises a friction modifier or mixtures thereof. In general, the friction modifier may be present in a range including 0wt% to 10wt%, 0.05wt% to 8wt% or 0.1wt% to 4wt%.

Examples of suitable friction modifiers include long chain fatty acid derivatives of amines, esters or epoxides; Fatty acid imidazolines (ie, long chain fatty acid amides, long chain fatty acid esters, long chain fatty acid epoxide derivatives, and long chain fatty acid imidazolines); And amine salts of alkaline phosphoric acid.

Friction modifiers also include materials such as sulfurized fatty acid compounds and monoesters of olefins, triglycerides (e.g. sunflower seed oil) or polyols, and aliphatic carboxylic acids, all of which have been described as antioxidants or antiwear agents. can do.

In one embodiment, the friction modifier is a long chain fatty acid amide, a long chain fatty acid ester, a long chain fatty acid epoxide derivative or a long chain fatty acid imidazoline.

In one embodiment, the friction modifier is a long chain fatty acid ester (described above as ashless antiwear agent). In other embodiments, the long chain fatty acid ester is a monoester and in other embodiments the long chain fatty acid ester is a (tri) glyceride.

Other additives

Other performance additives such as corrosion inhibitors are those described in paragraphs 5 to 8 of US patent application US05 / 038319 (filed Oct. 25, 2004, inventors McArty and Boyer), octylamine octanoate and dodecenyl succinic acid or Condensation products of fatty acids with polyamines such as anhydrides and oleic acid. In one embodiment, the corrosion inhibitor comprises a Synalox® corrosion inhibitor. Synalox® corrosion inhibitors are generally homopolymers or copolymers of propylene oxide. Synalox® corrosion inhibitors are available from The Dow Chemical Company. 118-01453-0702 is described in more detail in the product brochure with AMS. The product brochure is titled "SYNALOX Lubricants, High-Performance Polyglycols for Demanding Applications."

Metal deactivators are derivatives of benzotriazole (typically tolyltriazole), dimercaptothiadiazole derivatives, 1,2,4-triazole, benzimidazole, 2-alkyldithiobenzimidazole, or 2-alkyl Dithiobenzothiazole; Foam inhibitors include copolymers of ethylacrylate and 2-ethylhexylacrylate and optionally vinyl acetate; Demulsifiers include trialkyl phosphates, polyethylene glycols, polyethylene oxides, polypropylene oxides and (ethylene oxide-propylene oxide) polymers; Pour point depressants include esters of maleic anhydride-styrene, polymethacrylates, polyacrylates or polyacrylamides.

Industrial availability

Lubrication compositions can be used on a variety of surfaces commonly found in machinery including aluminum-alloy surfaces. Mechanisms include internal combustion engines, gearboxes, automatic transmissions, hydraulics or turbines. In general, the lubricating composition may be engine oil, gear oil, automatic transmission oil, hydraulic fluid, turbine oil, metalworking fluid or circulating oil. In one embodiment, the mechanical device is an internal combustion engine.

In one aspect, the internal combustion engine can be a diesel fuel engine, a gasoline fuel engine, a natural gas fuel engine or a mixed gasoline / alcohol fuel engine. In one aspect, the internal combustion engine can be a diesel fuel engine and in another aspect can be a gasoline fuel engine.

The internal combustion engine may be a two or four stroke engine. Suitable internal combustion engines include marine diesel engines, aircraft piston engines, low load diesel engines, and automobile and truck engines.

In one embodiment, the internal combustion engine contains components of aluminum-alloy. Aluminum alloys include aluminum silicates, aluminum oxides or other ceramic materials. In another embodiment, the aluminum-alloy is an aluminum-silicate surface. As used herein, the term "aluminum alloy" is synonymous with "aluminum composite" and includes components that comprise aluminum and other components that intermix or react at the microscopic or near microscopic level, regardless of their detailed structure. Or to represent a surface. This may include composite or alloy-like structures having non-metallic elements or compounds, such as all conventional alloys and ceramic-like materials that hold metals in addition to aluminum.

Lubricant compositions for internal combustion engines may be suitable for all engine lubricants regardless of sulfur, phosphorus or sulfated ash (ASTM D874) content. The sulfur content of the engine oil lubricant may be 1 wt% or less, 0.8 wt% or less, 0.5 wt% or less, or 0.3 wt% or less. In one embodiment, the sulfur content may range from 0.001 wt% to 0.5 wt% or 0.01 wt% to 0.3 wt%. The phosphorus content may be 0.2 wt% or less, 0.1 wt% or less, 0.085 wt% or less, 0.06 wt% or less, 0.055 wt% or less, or 0.05 wt% or less. In one embodiment, the phosphorus content may be between 100 ppm and 1000 ppm or 325 ppm and 700 ppm. The total content of sulfated ash may be 2 wt% or less, 1.5 wt% or less, 1.1 wt% or less, 1 wt% or less, 0.8 wt% or less, or 0.5 wt% or less. In one embodiment, the sulfated ash content may range from 0.05 wt% to 0.9 wt% or 0.1 wt% or 0.2 wt% to 0.45 wt%. In another embodiment, the sulfur content is 0.4 wt% or less, the phosphorus content is 0.08 wt% or less and the sulfated ash content is 1 wt% or less. In another embodiment, the sulfur content is 0.3 wt% or less, the phosphorus content is 0.05 wt% or less and the sulfated ash content is 0.8 wt% or less.

In one embodiment, the lubricating composition comprises an engine oil characterized by (i) a sulfur content of 0.5 wt% or less, (ii) a phosphorus content of 0.1 wt% or less, and (iii) a sulfated ash content of 1.5 wt% or less. to be.

In one embodiment, the lubricating composition is suitable for two-stroke or four-stroke marine diesel internal combustion engines. In one aspect, the marine diesel internal combustion engine is a two stroke engine. The ashless antiwear agent of the present invention may be added to the marine diesel lubricating composition at 0.01 to 20 wt%, 0.05 to 10 wt% or 0.1 to 5 wt%.

The following examples are intended to illustrate the present invention. This embodiment is non-exclusive and is not intended to limit the scope of the invention.

As used herein, the sum of the dispersant, detergent, and viscosity modifier contents set forth below includes the contents of conventional diluent oils. Typically, diluent oil accounts for 20 wt% to 90 wt% of each component. In the case of anti-wear, anti-corrosion, antioxidants, the stated content is on an active basis, ie diluent oil is excluded since the components are usually not contained in diluent oil.

Example 1 (EX1): 1 wt% di-2-ethylhexyl tartrate, 0.6 wt% other antiwear agent, 7.9 wt% dispersant, 1.5 wt% detergent, 3.6 wt% antioxidant containing an effective amount of molybdenum dithiocarbamate And a lubricating composition containing 6.1 wt% of a viscosity modifier, 0.1 wt% of a corrosion inhibitor, and 0.1 wt% of a friction modifier. The lubricating composition has a sulfated ash content of 0.6 wt%, a phosphorus content of about 570 ppm and a sulfur content of 0.17 wt%.

Example 2 (EX2): Antioxidant (Sakuralube ™ manufactured by Asahi Denka) containing 1 wt% C _12-14 -alkyl tartrate, 4.1 wt% dispersant, 1.4 wt% detergent, 0.7 wt% molybdenum dithiocarbamate A lubricating composition containing 2.5 wt% of a commercial item 515), 0.56 wt% of abrasion resistant agent, 0.1 wt% of corrosion inhibitor, and 0.1 wt% of friction modifier are prepared. The phosphorus content of this lubricating composition is about 560 ppm.

Comparative Example 1 (CE1): Similar to Example 2, except that it does not contain 0.7 wt% molybdenum dithiocarbamate or 1 wt% C _12-14 -alkyl tartrate.

Comparative Example 2 (CE2): Similar to Example 2, except that it did not contain 0.7 wt% molybdenum dithiocarbamate.

Comparative Example 3 (CE3): similar to Example 2, except not containing 1 wt% C _12-14 -alkyl tartrate.

Ten grams of the sample in this example were each treated with 1% by volume cumene hydroperoxide. This sample (2 ml volume) is then evaluated for wear performance by an isothermal high speed reciprocation suitability test (HFRR) available from PCS Instruments. HFRR conditions for evaluation are 500 g load, 75 minute duration, 1000 micrometer stroke, 20 hertz frequency and 105 ° C. Then, the wear flaw (micrometer) and film formation (film thickness%) were measured with low wear flaw values and high film formation values to indicate an improvement in wear performance. The results obtained are as follows:

Tartrate Example Abrasion Flaw (μm) Film thickness (%) EX2 169 95 CE1 358 One CE2 188 88 CE3 189 57

Overall, the results indicate that the lubricating composition of the present invention is (i) reducing or preventing emissions, (ii) reducing or preventing sulfur emissions, (ii) complete or partial replacement of ZDDP of lubricant, (iii) improved fuel economy, and ( iv) implying at least one of fuel economy maintenance / efficiency.

Example 3 (EX3): The lubricating composition is designed to meet Euro 4 and Euro 5 emission standards and to contain 1 wt% of C _8-10 alkyl tartrate. The lubricating composition has a phosphorus content of 900 ppm or less, sulfur 0.3 wt% or less and sulfated ash 0.9 wt% or less.

Example 4 (EX4): The lubricating composition is designed to meet Euro 4 and Euro 5 emission standards and to contain 1 wt% of C _8-10 alkyl tartrate. This lubricating composition has a phosphorus content of 500 ppm or less, sulfur 0.2 wt% or less and sulfated ash 0.5 wt% or less.

Comparative Examples 4 (CE4) and 5 (CE5): Lubricating compositions similar to EX3 and EX4, respectively, except that C _8-10 alkyl tartrate is not included.

Iron-catalyzed bulk oxidation tests were performed with EX3, EX4, CE4 and CE5. This test is carried out in the presence of 170 ° C., an air flow rate of 10 liters / hr and 360 ppm of iron catalyst. Oxidation is measured by monitoring the peak area increase of the CO stretch from the FT-IR. The results obtained in EX4 and CE5 show that the relative peak area increased by 383 units in EX4. In contrast, in CE5 the relative peak area increases by 428 units. Thus, the use of compounds falling within the definition of Formula 1 of the present invention reduces the oxidation of lubricants (especially internal combustion engines).

It is known that some of the foregoing materials may interact in the final formulation such that the components of the final formulation may differ from the initially added components. The products thus formed, such as those formed upon the use of the lubricant composition of the present invention in its intended use, cannot be easily explained. Nevertheless, all such changes and reaction products are included within the scope of the present invention, and the present invention includes lubricant compositions prepared upon mixing the aforementioned components.

Each of the documents mentioned above is incorporated herein by reference. Except in addition to the examples or other obvious indications, it is to be understood that all numerical quantities expressing substance content, reaction conditions, molecular weight, number of carbon atoms, etc. herein are modified by the word "about." Unless otherwise indicated, each compound or composition referred to herein is to be interpreted as a commercial grade material which may contain isomers, by-products, derivatives and other materials generally understood to be present in the commercial grade. However, the amounts of each chemical component are values excluding any solvent or diluent oil which may conventionally be present in the commercial materials, unless otherwise indicated. It is to be understood that the upper, lower, and lower limits of content, range, and ratio set forth herein may be combined independently. Similarly, the range and content of each element of the present invention may be used with the range or content of any other element.

As used herein, the terms "hydrocarbyl substituent" or "hydrocarbyl group" are used in their ordinary meanings known to those skilled in the art. Specifically, it refers to a group in which a carbon atom is directly attached to the rest of the molecule and mainly exhibits hydrocarbon properties. Examples of hydrocarbyl groups include the following:

(i) hydrocarbon substituents, ie aliphatic (eg, alkyl or alkenyl), aliphatic ring (eg, cycloalkyl, cycloalkenyl) substituents, and aromatic-, aliphatic- and aliphatic ring-substituted aromatic substituents, and cyclic molecule Ring substituents, complete through different moieties of (eg, two substituents together form a ring);

(ii) substituted hydrocarbon substituents, i.e., substituents containing non-hydrocarbon groups that do not primarily alter the hydrocarbon nature of the substituents (e.g. halo (especially chloro and fluoro), hydroxy, alkoxy, mercapto, al) Chelmercapto, nitro, nitroso and sulfoxy);

(iii) hetero substituents, ie substituents which exhibit primarily hydrocarbon properties in the context of the present invention, but contain other than carbon in a ring or chain consisting of carbon atoms.

Heteroatoms include sulfur, oxygen, nitrogen and include substituents such as pyridyl, furyl, thienyl and imidazolyl. In general, there will be up to two non-hydrocarbon substituents per ten carbon atoms in the hydrocarbyl group; Usually, non-hydrocarbon substituents are not usually present in hydrocarbyl groups.

While the present invention has been described in connection with its preferred embodiments, those skilled in the art will clearly appreciate the various modifications thereof. Accordingly, it is to be understood that the invention disclosed herein includes such modifications as long as they fall within the scope of the following claims.

The anti-wear agents described herein include at least one additional —OH, 0NHR, wherein R is hydrogen or alkyl, such as C1-, separated by a chain of two or three atoms from the carbon of the first carboxy group and the first carboxy group. 6 alkyl) or an oil soluble derivative of a molecule containing a = 0 moiety.

Claims (22)

A lubricating composition comprising an oil of lubricating viscosity, an oil soluble molybdenum compound, and an ashless antiwear agent represented by the following general formula (1): [Formula 1]

[In this equation, Y and Y 'are independently -O-,>NH,> NR ³ or an imide group made by taking together the Y and Y' groups and forming a R ¹ -N <group between two> C═O groups; X is independently -ZO-Z'-,> CH ₂ ,> CHR ⁴ ,> CR ⁴ R ⁵ ,> C (OH) (CO ₂ R ² ),> C (CO ₂ R ² ) ₂ ,> CCH ₂ CO ₂ R ² or> CHOR ⁶ ; Z and Z 'are independently> CH ₂ ,> CHR ⁴ ,> CR ⁴ R ⁵ ,> C (OH) (CO ₂ R ² ) or> CHOR ⁶ ; n is 0 to 10, provided that when n = 1, X is not> CH ₂ , and when n = 2, both X ′ are not> CH ₂ simultaneously; m is 0 or 1; R ¹ is independently hydrogen or a hydrocarbyl group which generally contains 1 to 150 carbon atoms, provided that when R ¹ is hydrogen, m is 0 and n is at least 1; R ² is generally a hydrocarbyl group containing 1 to 150 carbon atoms; R ³ , R ⁴ and R ⁵ are independently hydrocarbyl groups or hydroxy containing hydrocarbyl groups or carboxy containing hydrocarbyl groups; R ⁶ is hydrogen or a hydrocarbyl group containing generally 1 to 150 carbon atoms. The lubricating composition of claim 1, wherein the ashless antiwear agent of formula I is derived from at least one hydroxy-polycarboxylic acid. The ashless antiwear agent according to claim 1, wherein the ashless antiwear agent is hydroxy-polycarboxylic acid di-ester, hydroxy-polycarboxylic acid di-amide, hydroxy-polycarboxylic acid imide, hydroxy-polycarboxylic acid di-imide, hydroxy-poly A lubricating composition comprising a carboxylic acid ester-amide, a hydroxy-polycarboxylic acid ester-imide and a hydroxy-polycarboxylic acid imide-amide. The lubricating composition according to claim 1, wherein the ashless antiwear agent represented by the formula (1) is imide, di-ester or di-amide.  The lubricating composition of claim 1, wherein Y and Y ′ in formula 1 are both —O—. The compound of claim 1, wherein m is 0 or 1, n is 1 to 2, X is> CHOR ⁶ , R ¹ , R ^2, and R ⁶ is independently a hydro containing 4 to 30 carbon atoms. Carbyl group, lubricating composition. The lubricating composition of claim 1 wherein the ashless antiwear agent is derived from tartaric acid or citric acid. The lubricating composition of claim 1 wherein the ashless antiwear agent is present at 0.05 to 10 wt% or 0.1 to 5 wt% of the lubricating composition. The group according to claim 1, wherein the oil soluble molybdenum compound consists of molybdenum dithiocarbamate, molybdenum dialkyldithiophosphate, amine salt of molybdenum compound, molybdenum xanthate, molybdenum sulfide, molybdenum carboxylate and molybdenum alkoxide A lubricating composition selected from at least one compound of the. The lubricating composition of claim 9, wherein the oil soluble molybdenum compound is selected from at least one compound of the group consisting of molybdenum dithiocarbamate, molybdenum dialkyldithiophosphate and an amine salt of molybdenum compound. The lubricating composition of claim 10 wherein the oil soluble molybdenum compound is molybdenum dithiocarbamate. The lubricating composition of claim 1, wherein the oil soluble molybdenum compound is present in an amount that provides 0.5 ppm to 2000 ppm, 1 ppm to 700 ppm, or 20 ppm to 250 ppm molybdenum. The method of claim 1 further comprising at least one of (i) sulfur content of 0.8 wt% or less, (ii) phosphorus content of 0.2 wt% or less, or (iii) sulfated ash content of 2 wt% or less. Lubrication composition. The lubricating composition of claim 1 having (i) sulfur content of 0.5 wt% or less, (ii) phosphorus content of 0.1 wt% or less and (iii) sulfated ash content of 1.5 wt% or less. The method of claim 1 further comprising at least one of a friction modifier (in addition to the oil soluble molybdenum compound or the compound of formula 1), a viscosity modifier, an antioxidant (in addition to the oil soluble molybdenum compound), an overbased detergent, a succinimide dispersant or a mixture thereof. A lubricating composition comprising one. The lubricating composition of claim 15 wherein the friction modifier is selected from the group consisting of long chain fatty acid amides, long chain fatty acid esters, long chain fatty acid epoxide derivatives, long chain fatty acid imidazolines and amine salts of alkylphosphoric acids. The lubricating composition according to claim 1, further comprising a phosphorus-containing antiwear agent. The lubricating composition of claim 1 further comprising an overbased detergent. 19. The lubricating composition of claim 18, wherein the overbased detergent is selected from the group consisting of non-sulfur containing phenates, sulfur containing phenates, sulfonates, salicylates, salicylates, and mixtures thereof. A method for lubricating an internal combustion engine, comprising supplying the lubricating composition according to claim 1 to an internal combustion engine. Use of tartaric acid derivative used as an antioxidant in lubricants. 22. The use of claim 21 wherein the tartaric acid derivative is a tartrate ester.