US20200165537A1

US20200165537A1 - Lubricating oil compositions with improved deposit resistance and methods thereof

Info

Publication number: US20200165537A1
Application number: US16/680,651
Authority: US
Inventors: Douglas E. Deckman; Andrew D. SATTERFIELD; Willie A. Givens, Jr.
Original assignee: ExxonMobil Research and Engineering Co
Current assignee: ExxonMobil Technology and Engineering Co
Priority date: 2018-11-28
Filing date: 2019-11-12
Publication date: 2020-05-28
Also published as: WO2020112338A1

Abstract

Provided is a lubricating oil composition and method of using such a composition that provides for improved high temperature deposit resistance. The composition includes a lubricating oil base stock at from 20 to 95 wt % of the composition, at least one ashless organic friction modifier at from 0.1 to 20 wt % of the composition, and at least one overbased detergent at from 0.1 to 20 wt % of the composition. The remainder of composition includes one or more other lubricating oil additives. The deposit resistance of the lubricating oil composition as measured by TEOST 33C total deposits is at least 20% lower than the deposit resistance for a comparable lubricating oil composition not including the combination of the at least one ashless organic friction modifier and the at least one overbased detergent.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No. 62/772,360, filed on Nov. 28, 2018, the entire contents of which are incorporated herein by reference.

FIELD

This disclosure relates to lubricating oils with improved deposit resistance and in particular, high temperature deposit resistance, and methods of making and using such lubricating oils. The lubricating oils include one or more ashless organic friction modifiers in combination with one or more overbased detergents. The lubricating oils are useful as passenger vehicle engine oil (PVEO) products or commercial vehicle engine oil (CVEO) products.

BACKGROUND

Lubricating oils for internal combustion engines contain in addition to at least one base lubricating oil, additives which enhance the performance of the lubricating oil. A variety of additives such as antioxidants, detergents, dispersants, friction modifiers, viscosity modifiers, corrosion inhibitors, antiwear additives, pour point depressants, seal swell additives, and antifoam agents are used in lubricating oil compositions.
During engine operation, oil insoluble oxidation byproducts are produced. Deposit formation in a lubricating oil will lead to the deposits eventually falling out of the oil and depositing on the surfaces for lubrication, which negatively impacts the performance of the oil. Dispersants help keep these byproducts in solution, thus diminishing their deposit on metal surfaces. Dispersants may be ashless or ash-forming (non-ashless) in nature. So called ashless dispersants are organic materials that form substantially no ash upon combustion.
A known class of dispersants is the alkenylsuccinic derivatives, typically produced by the reaction of a long chain substituted alkenyl succinic compound, usually a substituted succinic anhydride, with a polyhydroxy or polyamino compound. The long chain group constituting the oleophilic portion of the molecule which confers solubility in the oil, is normally a polyisobutylene group. Many examples of this type of dispersant are well known commercially and in the literature.
Engine cleanliness is a critical performance attribute of modern engine lubricants. A well-known engine cleanliness test is the TEOST 33C (ASTM D6335) deposit bench test, which is designed to simulate temperatures experienced in turbochargers.
Auto builders are faced with challenging emission requirements and CAFE requirements, and therefore are broadly deploying turbocharged engines. Turbochargers are exposed to engine exhaust gas and operate at speeds of 100,000 rpm or higher. As a result of these operating conditions, generation of deposits on the turbocharged engine surfaces greatly deteriorates engine performance. Therefore, there is a need for lubricating oils that when used with turbocharged passenger vehicle engines and turbocharged commercial vehicle engines provide for an improvement in high temperature deposit formation, deposit resistance and cleanliness performance. There is also a need for lubricating oils that provide for improvement cleanliness of mechanical components lubricated by such oils.

SUMMARY

This disclosure relates to lubricating oils which provide surprising and unexpected improvements in deposit resistance (in particular high temperature deposit resistance) and cleanliness and methods of making and using such lubricating oils. The lubricating oils of this disclosure include one or more ashless organic friction modifiers in combination with one or more overbased detergents that provide improvements in cleanliness performance. The disclosure also relates to methods of using such lubricating oils to improve passenger vehicle engine and commercial vehicle engine performance and in particular for turbocharged engines.
In one form the instant disclosure, a lubricating oil composition comprises: a lubricating oil base stock at from 20 to 95 wt % of the composition, at least one ashless organic friction modifier at from 0.1 to 20 wt % of the composition, at least one overbased detergent at from 0.1 to 20 wt % of the composition, and wherein the remainder of the lubricating oil composition includes one or more other lubricating oil additives. The at least one ashless organic friction modifier is selected from the group consisting of
wherein A and B are each independently H, a C1-C24 alkyl, or a C2-C24 alkenyl;
wherein A, B and C are each independently H, a C1-C24 alkyl, a C2-C24 alkenyl, a C1-C24 alkylcarbonyl, and a C1-C24 alkenylcarbonyl;
wherein A is a C1-C24 alkyl, or a C2-C24 alkenyl and B is O, an amino, a C1-C8 alkylamino or a C1-C8 dialkylamino;
n- tallow 1,3 diaminopropane; a polymeric organic friction modifier containing PIBSA, glycerol and oligomerized ethylene oxide and combinations thereof. The deposit resistance of the lubricating oil composition as measured by TEOST 33C total deposits (ASTM D6335) is at least 20% lower than the deposit resistance for a comparable lubricating oil composition not including the combination of the at least one ashless organic friction modifier and the at least one overbased detergent.
In another form the instant disclosure, a method for improving the high temperature deposit resistance of a lubricating oil composition for use in lubricating a mechanical component comprises: providing a lubricating oil composition to a mechanical component, wherein the lubricating oil composition comprises: a lubricating oil base stock at from 20 to 95 wt % of the composition, at least one ashless organic friction modifier at from 0.1 to 20 wt % of the composition, at least one overbased detergent at from 0.1 to 20 wt % of the composition, and wherein the remainder of the lubricating oil composition includes one or more other lubricating oil additives. The at least one ashless organic friction modifier is selected from the group consisting of
wherein A and B are each independently H, a C1-C24 alkyl, or a C2-C24 alkenyl;
wherein A, B and C are each independently H, a C1-C24 alkyl, a C2-C24 alkenyl, a C1-C24 alkylcarbonyl, and a C1-C24 alkenylcarbonyl;
wherein A is a C1-C24 alkyl, or a C2-C24 alkenyl and B is O, an amino, a C1-C8 alkylamino or a C1-C8 dialkylamino;
n- tallow 1,3 diaminopropane; a polymeric organic friction modifier containing PIBSA, glycerol and oligomerized ethylene oxide and combinations thereof. The method provides a deposit resistance as measured by TEOST 33C total deposits (ASTM D6335) that is at least 20% lower than the deposit resistance for a comparable lubricating oil composition not including the combination of the at least one ashless organic friction modifier and the at least one overbased detergent.
Other objects and advantages of the present disclosure will become apparent from the detailed description and drawings that follow.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a tabular depiction of TEOST 33C results for partially formulated lubricating oil compositions of the Examples including various base stocks and combinations of high TBN calcium salicylate detergent and ashless organic friction modifier.

FIG. 2 shows a tabular depiction of TEOST 33C results for partially formulated lubricating oil compositions of the Examples including a combination of various high TBN detergents and ashless organic friction modifier with a 4 cSt PAO base stock.

FIG. 3 shows a tabular depiction of TEOST 33C results for partially formulated lubricating oil compositions of the Examples including various friction modifiers in combination with a high TBN calcium salicylate detergent in a 4 cSt PAO base stock.

FIG. 4 shows a tabular depiction of TEOST 33C results for partially formulated lubricating oil compositions of the Examples including a combination of high TBN calcium salicylate detergent in combination with an ashless organic friction modifier at various loadings (0 to 1 wt. % of the partially formulated oil) in a 4 cSt PAO base stock.

FIG. 5 shows a graphical depiction of TEOST 33C results versus ashless organic friction modifier loading for the partially formulated lubricating oil compositions of the Examples of FIG. 4.

DETAILED DESCRIPTION

Definitions

“About” or “approximately.” All numerical values within the detailed description and the claims herein are modified by “about” or “approximately” the indicated value, and take into account experimental error and variations that would be expected by a person having ordinary skill in the art.
“Alkyl” as it relates to the ashless organic friction modifiers includes straight-chain or branched alkyl groups, such as, methyl, ethyl, n-propyl, i-propyl or the different butyl, pentyl or hexyl isomers.
“Alkenyl” as it relates to the ashless organic friction modifiers includes straight-chain or branched alkenes such as ethenyl, 1-propenyl, 2-propenyl, and the different butenyl, pentenyl and hexenyl isomers.
“Alkylcarbonyl” as it relates to the ashless organic friction modifiers denotes a straight-chain or branched alkyl moieties bonded to a C(═O) moiety. Examples of “alkylcarbonyl” include CH₃C(═O)—, CH₃CH₂CH₂C)═O)— and (CH₃)₂CHC(═O)—.
“Major amount” as it relates to components included within the lubricating oils of the specification and the claims means greater than or equal to 50 wt. %, or greater than or equal to 60 wt. %, or greater than or equal to 70 wt. %, or greater than or equal to 80 wt. %, or greater than or equal to 90 wt. % based on the total weight of the lubricating oil.
“Minor amount” as it relates to components included within the lubricating oils of the specification and the claims means less than 50 wt. %, or less than or equal to 40 wt. %, or less than or equal to 30 wt. %, or greater than or equal to 20 wt. %, or less than or equal to 10 wt. %, or less than or equal to 5 wt. %, or less than or equal to 2 wt. %, or less than or equal to 1 wt. %, based on the total weight of the lubricating oil.
“Essentially free” as it relates to components included within the lubricating oils of the specification and the claims means that the particular component is at 0 weight % within the lubricating oil, or alternatively is at impurity type levels within the lubricating oil (less than 100 ppm, or less than 20 ppm, or less than 10 ppm, or less than 1 ppm).
“Other lubricating oil additives” as used in the specification and the claims means other lubricating oil additives that are not specifically recited in the particular section of the specification or the claims. For example, other lubricating oil additives may include, but are not limited to, antioxidants, detergents, dispersants, antiwear additives, corrosion inhibitors, viscosity modifiers, metal passivators, pour point depressants, seal compatibility agents, antifoam agents, extreme pressure agents, friction modifiers and combinations thereof.
“Hydrocarbon” refers to a compound consisting of carbon atoms and hydrogen atoms.
“Alkane” refers to a hydrocarbon that is completely saturated. An alkane can be linear, branched, cyclic, or substituted cyclic.
“Olefin” refers to a non-aromatic hydrocarbon comprising one or more carbon-carbon double bond in the molecular structure thereof.
“Mono-olefin” refers to an olefin comprising a single carbon-carbon double bond.
“Cn” group or compound refers to a group or a compound comprising carbon atoms at total number thereof of n. Thus, “Cm-Cn” group or compound refers to a group or compound comprising carbon atoms at a total number thereof in the range from m to n. Thus, a C1-C50 alkyl group refers to an alkyl group comprising carbon atoms at a total number thereof in the range from 1 to 50.
“Carbon backbone” refers to the longest straight carbon chain in the molecule of the compound or the group in question. “Branch” refer to any substituted or unsubstituted hydrocarbyl group connected to the carbon backbone. A carbon atom on the carbon backbone connected to a branch is called a “branched carbon.”
“Epsilon-carbon” in a branched alkane refers to a carbon atom in its carbon backbone that is (i) connected to two hydrogen atoms and two carbon atoms and (ii) connected to a branched carbon via at least four (4) methylene (CH₂) groups. Quantity of epsilon carbon atoms in terms of mole percentage thereof in a alkane material based on the total moles of carbon atoms can be determined by using, e.g., ¹³C NMR.
“SAE” refers to SAE International, formerly known as Society of Automotive Engineers, which is a professional organization that sets standards for internal combustion engine lubricating oils.
“SAE J300” refers to the viscosity grade classification system of engine lubricating oils established by SAE, which defines the limits of the classifications in rheological terms only.
“Base stock” or “base oil” interchangeably refers to an oil that can be used as a component of lubricating oils, heat transfer oils, hydraulic oils, grease products, and the like.
“Lubricating oil” or “lubricant” interchangeably refers to a substance that can be introduced between two or more surfaces to reduce the level of friction between two adjacent surfaces moving relative to each other. A lubricant base stock is a material, typically a fluid at various levels of viscosity at the operating temperature of the lubricant, used to formulate a lubricant by admixing with other components. Non-limiting examples of base stocks suitable in lubricants include API Group I, Group II, Group III, Group IV, and Group V base stocks. PAOs, particularly hydrogenated PAOs, have recently found wide use in lubricants as a Group IV base stock, and are particularly preferred. If one base stock is designated as a primary base stock in the lubricant, additional base stocks may be called a co-base stock.
All kinematic viscosity values in this disclosure are as determined pursuant to ASTM D445. Kinematic viscosity at 100° C. is reported herein as KV100, and kinematic viscosity at 40° C. is reported herein as KV40. Unit of all KV100 and KV40 values herein is cSt unless otherwise specified.
All viscosity index (“VI”) values in this disclosure are as determined pursuant to ASTM D2270.
All Noack volatility (“NV”) values in this disclosure are as determined pursuant to ASTM D5800 unless specified otherwise. Unit of all NV values is wt %, unless otherwise specified.
All pour point values in this disclosure are as determined pursuant to ASTM D5950 or D97.
All CCS viscosity (“CCSV”) values in this disclosure are as determined pursuant to ASTM 5293. Unit of all CCSV values herein is millipascal second (mPa·s), which is equivalent to centipoise), unless specified otherwise. All CCSV values are measured at a temperature of interest to the lubricating oil formulation or oil composition in question. Thus, for the purpose of designing and fabricating engine oil formulations, the temperature of interest is the temperature at which the SAE J300 imposes a minimal CCSV.
All percentages in describing chemical compositions herein are by weight unless specified otherwise. “Wt. %” means percent by weight.
Lubricating Oil Compositions and Methods of this Disclosure
It has been surprisingly found that, in accordance with this disclosure deposit resistance (in particular high temperature deposit resistance) and engine cleanliness are improved for lubricating oils including one or more ashless organic friction modifiers in combination with one or more overbased detergents in comparison to comparable lubricating oils not including the combinations of one or more ashless organic friction modifiers and one or more overbased detergents disclosed herein.
In particular, it has been surprisingly found that, for lubricating oils of this disclosure containing a lubricating oil base stock at from 20 to 95 wt % of the composition, at least one ashless organic friction modifier at from 0.1 to 20 wt % of the composition, at least one overbased detergent at from 0.1 to 20 wt % of the composition, and wherein the remainder of the lubricating oil composition includes one or more other lubricating oil additives provide for a deposit resistance as measured by TEOST 33C total deposits (ASTM D6335) that is at least 20% lower than the deposit resistance for a comparable lubricating oil composition not including the combination of the at least one ashless organic friction modifier and the at least one overbased detergent.
The at least one ashless organic friction modifier may be selected from the group consisting of
wherein A and B are each independently H, a C1-C24 alkyl, or a C2-C24 alkenyl;
wherein A, B and C are each independently H, a C1-C24 alkyl, a C2-C24 alkenyl, a C1-C24 alkylcarbonyl, and a C1-C24 alkenylcarbonyl;
wherein A is a C1-C24 alkyl, or a C2-C24 alkenyl and B is O, an amino, a C1-C8 alkylamino or a C1-C8 dialkylamino;
n- tallow 1,3 diaminopropane; a polymeric organic friction modifier containing PIBSA, glycerol and oligomerized ethylene oxide and combinations thereof.
For the at least one ashless organic friction modifier, it is preferable if it is selected from the group consisting of mixed mono-(47%), di-(33%) and tri-(20%) fatty acids using saturated C16 and C18 alkyl chains, glycerol mono-, di- and tri-mixed oleate, propylene glycol stearyl ether, poly-hydroxylcarboxylic acid esters of polyalkylene oxide modified polyols, n- tallow 1,3 diaminopropane, oleic acid, oleyl amide, and polymeric organic friction modifier containing PIBSA, glycerol and oligomerized ethylene oxide and combinations thereof.
In alternative forms, the deposit resistance as measured by TEOST 33C total deposits (ASTM D6335) of the lubricating oil compositions disclosed herein is at least 100% lower, or at least 90% lower, or at least 80% lower, or at least 70% lower, or at least 60% lower, or at least 50% lower, or at least 40% lower, or at least 30% lower, or at least 10% lower than a comparable lubricating oil composition not including the combination of one or more ashless organic friction modifiers and one or more overbased detergents disclosed herein.
The lubricating oil compositions disclosed herein provide a TEOST 33C deposits of less than or equal to 80 mg, or less than or equal to 70 mg, or less than or equal to 60 mg, or less than or equal to 50 mg, or less than or equal to 40 mg, or less than or equal to 30 mg, or less than or equal to 20 mg, or less than or equal to 10 mg. The benefit in TEOST 33C deposits (lower TEOST 33C values) provided by the lubricating oil compositions including one or more ashless organic friction modifiers in combination with one or more overbased detergents in comparison to comparable lubricating oil compositions not including the combinations of one or more ashless organic friction modifiers and one or more overbased detergents disclosed is surprising and unexpected.
In accordance with this disclosure, a method is also provided to improve the high temperature deposit resistance of a lubricating oil composition for use in lubricating a mechanical component comprising: providing a lubricating oil composition to a mechanical component, wherein the lubricating oil composition comprises: a lubricating oil base stock at from 20 to 95 wt % of the composition, at least one ashless organic friction modifier at from 0.1 to 20 wt % of the composition, at least one overbased detergent at from 0.1 to 20 wt % of the composition, and wherein the remainder of the lubricating oil composition includes one or more other lubricating oil additives. The method provides for a deposit resistance as measured by TEOST 33C total deposits (ASTM D6335) that is at least 20% lower than the deposit resistance for a comparable lubricating oil composition not including the combination of the at least one ashless organic friction modifier and the at least one overbased detergent. The at least one ashless organic friction modifier may be selected from the group consisting of
wherein A and B are each independently H, a C1-C24 alkyl, or a C2-C24 alkenyl;
wherein A, B and C are each independently H, a C1-C24 alkyl, a C2-C24 alkenyl, a C1-C24 alkylcarbonyl, and a C1-C24 alkenylcarbonyl;
wherein A is a C1-C24 alkyl, or a C2-C24 alkenyl and B is O, an amino, a C1-C8 alkylamino or a C1-C8 dialkylamino;
n- tallow 1,3 diaminopropane; a polymeric organic friction modifier containing PIBSA, glycerol and oligomerized ethylene oxide and combinations thereof.
For the at least one ashless organic friction modifier, it is preferable that it is selected from the group consisting of mixed mono-(47%), di-(33%) and tri-(20%) fatty acids using saturated C16 and C18 alkyl chains, glycerol mono-, di- and tri-mixed oleate, propylene glycol stearyl ether, poly-hydroxylcarboxylic acid esters of polyalkylene oxide modified polyols, n- tallow 1,3 diaminopropane, oleic acid, oleyl amide, and polymeric organic friction modifier containing PIBSA, glycerol and oligomerized ethylene oxide and combinations thereof.
The method to improve high temperature deposit resistance of a lubricating oil composition for use in lubricating a mechanical component provides a TEOST 33C deposits of less than or equal to 80 mg, or less than or equal to 70 mg, or less than or equal to 60 mg, or less than or equal to 50 mg, or less than or equal to 40 mg, or less than or equal to 30 mg, or less than or equal to 20 mg, or less than or equal to 10 mg. The benefit in TEOST 33C deposits (lower TEOST 33C values) provided by the methods to improve high temperature deposit resistance of a lubricating oil composition including one or more ashless organic friction modifiers in combination with one or more overbased detergents in comparison to comparable lubricating oil compositions not including the combinations of one or more ashless organic friction modifiers and one or more overbased detergents disclosed is surprising and unexpected.
The methods to improve deposit resistance of this disclosure provide advantaged cleanliness performance in the lubrication of internal combustion engines, power trains, drivelines, transmissions, gears, gear trains, gear sets, compressors, pumps, hydraulic systems, bearings, bushings, turbines, and the like. Also, the methods to improve deposit resistance of this disclosure provide advantaged cleanliness performance in the lubrication of mechanical components, which can include, for example, pistons, piston rings, cylinder liners, cylinders, cams, tappets, lifters, bearings (journal, roller, tapered, needle, ball, and the like), gears, valves, and the like. Further, the lubricating oil compositions of this disclosure provide advantaged cleanliness performance and deposit resistance as a component in lubricant compositions, which can include, for example, lubricating liquids, semi-solids, solids, greases, dispersions, suspensions, material concentrates, additive concentrates, and the like.

Friction Modifiers

A friction modifier is any material or materials that can alter the coefficient of friction of a surface lubricated by any lubricant or fluid containing such material(s). Friction modifiers, also known as friction reducers, friction improvers, or lubricity agents or oiliness agents, and other such agents that change the ability of base oils, formulated lubricant compositions, or functional fluids, to modify the coefficient of friction of a lubricated surface may be effectively used in combination with the base oils or lubricant compositions of the present disclosure if desired. Friction modifiers that lower the coefficient of friction are particularly advantageous in combination with the base oils and lube compositions of this disclosure.
Ashless organic friction modifiers are in included in the lubricating oil compositions of this disclosure. In particular, the inventive lubricating oils of this disclosure include at least one ashless organic friction modifier, which is incorporated at from 0.01 to 20 wt %, or 0.05 to 18 wt %, or 0.1 to 15 wt %, or 0.3 to 10 wt %, or 0.5 to 5 wt %, or 0.6 to 4 wt %, or 0.7 to 3 wt %, or 0.8 to 2.5 wt %, or 0.9 to 2.0 wt %, or 1.0 to 1.5 wt % of the lubricating oil composition.
Ashless organic friction modifiers useful in this disclosure may include lubricant materials that contain effective amounts of polar groups, for example, hydroxyl-containing hydrocarbyl base oils, glycerides, partial glycerides, glyceride derivatives, and the like. Polar groups in friction modifiers may include hydrocarbyl groups containing effective amounts of 0, N, S, or P, individually or in combination. Other friction modifiers that may be particularly effective include, for example, salts (both ash-containing and ashless derivatives) of fatty acids, fatty alcohols, fatty amides, fatty esters, hydroxyl-containing carboxylates, and comparable synthetic long-chain hydrocarbyl acids, alcohols, amides, esters, hydroxy carboxylates, and the like. In some instances fatty organic acids, fatty amines, and sulfurized fatty acids may be used as suitable friction modifiers.
Other illustrative friction modifiers useful in the lubricating engine oil formulations of this disclosure include, for example, alkoxylated fatty acid esters, alkanolamides, polyol fatty acid esters, borated glycerol fatty acid esters, fatty alcohol ethers, and mixtures thereof.
Illustrative alkoxylated fatty acid esters include, for example, polyoxyethylene stearate, fatty acid polyglycol ester, and the like. These can include polyoxypropylene stearate, polyoxybutylene stearate, polyoxyethylene isosterate, polyoxypropylene isostearate, polyoxyethylene palmitate, and the like.
Illustrative alkanolamides include, for example, lauric acid diethylalkanolamide, palmic acid diethylalkanolamide, and the like. These can include oleic acid diethyalkanolamide, stearic acid diethylalkanolamide, oleic acid diethylalkanolamide, polyethoxylated hydrocarbylamides, polypropoxylated hydrocarbylamides, and the like.
Illustrative polyol fatty acid esters include, for example, glycerol mono-oleate, glycerol mono-, di- and tri-mixed oleate, saturated mono-, di-, and tri-glyceride esters, glycerol mono-stearate, and the like. These can include polyol esters, hydroxyl-containing polyol esters, and the like.
Illustrative borated glycerol fatty acid esters include, for example, borated glycerol mono-oleate, borated glycerol mono-, di- and tri-mixed oleate, borated saturated mono-, di-, and tri-glyceride esters, borated glycerol mono-sterate, and the like. In addition to glycerol polyols, these can include trimethylolpropane, pentaerythritol, sorbitan, and the like. These esters can be polyol monocarboxylate esters, polyol dicarboxylate esters, and on occasion polyoltricarboxylate esters. Preferred can be the glycerol mono-oleates, glycerol dioleates, glycerol trioleates, glycerol mono-, di- and tri-mixed oleates, glycerol monostearates, glycerol distearates, and glycerol tristearates and the corresponding glycerol monopalmitates, glycerol dipalmitates, and glycerol tripalmitates, and the respective isostearates, linoleates, and the like. On occasion the glycerol esters can be preferred as well as mixtures containing any of these. Ethoxylated, propoxylated, butoxylated fatty acid esters of polyols, especially using glycerol as underlying polyol can be preferred.
Illustrative fatty alcohol ethers include, for example, stearyl ether, myristyl ether, and the like. Alcohols, including those that have carbon numbers from C3 to C50, can be ethoxylated, propoxylated, or butoxylated to form the corresponding fatty alkyl ethers. The underlying alcohol portion can preferably be stearyl, myristyl, C₁₁-C₁₃hydrocarbon, oleyl, isosteryl, and the like.
In certain embodiments, the friction modifier comprises at least one of a long chain alkly thiocarbamide, mixed glyceride ester (substituted or unsubstituted), ethoxylated fatty ester, phenyl, or combination thereof. In certain embodiments, the friction modifier is selected from the group consisting of a molybdenum-containing friction modifier (long chain alkyl thio carbamide molybdenum complex), a mono, di and/or trimester; mostly saturated C14, C16 & C18; an ethoxylated fatty ester; an ester/ether block copolymer, and combinations thereof.
Advantageous ashless organic friction modifiers for the lubricating oil compositions of the instant disclosure include the following:
wherein A and B are each independently H, a C1-C24 alkyl, or a C2-C24 alkenyl.
In a preferable form of structure (1), A is CH₃and B is a C16-C20 alkyl group.
wherein A, B and C are each independently H, a C1-C24 alkyl, a C2-C24 alkenyl, a C1-C24 alkylcarbonyl, and a C1-C24 alkenylcarbonyl.
In a preferable form of structure (2), A is a C14-C20 alkylcarbonyl or a C14-C20 alkenylcarbonyl
wherein A is a C1-C24 alkyl, or a C2-C24 alkenyl and B is O, an amino, a C1-C8 alkylamino or a C1-C8 dialkylamino.
In a preferable form of structure (3), A is a C14-C20 alkyl or a C14-C20 alkenyl and B is oxygen.
Preferred ashless friction modifiers for the lubricating oil compositions of the instant disclosure include mixed mono-(47%), di-(33%) and tri-(20%) fatty acids using saturated C16 and C18 alkyl chains), a glycerol mono-, di- and tri-mixed oleate, a propylene glycol stearyl ether, a poly-hydroxylcarboxylic acid esters of polyalkylene oxide modified polyols, n- tallow 1,3 diaminopropane, oleic acid, oleyl amide, and a polymeric organic friction modifier containing PIBSA, glycerol and oligomerized ethylene oxide.
Other optional non-ashless (ash forming) inorganic friction modifiers for use in combination with the at least one ashless organic friction modifier may include metal-containing compounds in combination with the ashless organic friction modifiers disclosed herein. Illustrative metal-containing friction modifiers may include, for example, inorganic compounds or materials, or mixtures thereof. Illustrative optional inorganic friction modifiers useful in the lubricating engine oil formulations of this disclosure include, for example, molybdenum amine, molybdenum diamine, an organotungstenate, a molybdenum dithiocarbamate, molybdenum dithiophosphates, molybdenum amine complexes, molybdenum carboxylates, and the like, and mixtures thereof. Similar tungsten based compounds may be preferable.
Optional non-ashless (ash forming) metal-containing inorganic friction modifiers may include metal salts or metal-ligand complexes where the metals may include alkali, alkaline earth, or transition group metals. Such metal-containing friction modifiers may also have low-ash characteristics. Transition metals may include Mo, Sb, Sn, Fe, Cu, Zn, and others. Ligands may include hydrocarbyl derivative of alcohols, polyols, glycerols, partial ester glycerols, thiols, carboxylates, carbamates, thiocarbamates, dithiocarbamates, phosphates, thiophosphates, dithiophosphates, amides, imides, amines, thiazoles, thiadiazoles, dithiazoles, diazoles, triazoles, and other polar molecular functional groups containing effective amounts of O, N, S, or P, individually or in combination. In particular, Mo-containing compounds can be particularly effective such as for example Mo-dithiocarbamates, Mo(DTC), Mo-dithiophosphates, Mo(DTP), Mo-amines, Mo (Am), Mo-alcoholates, Mo-alcohol-amides, etc. See U.S. Pat. Nos. 5,824,627; 6,232,276; 6,153,564; 6,143,701; 6,110,878; 5,837,657; 6,010,987; 5,906,968; 6,734,150; 6,730,638; 6,689,725; 6,569,820; WO 99/66013; WO 99/47629; WO 98/26030.
Useful concentrations of optional non-ashless (ash forming) friction modifiers may range from 0.01 weight percent to 5 weight percent, or about 0.1 weight percent to about 2.5 weight percent, or about 0.1 weight percent to about 1.5 weight percent, or about 0.1 weight percent to about 1 weight percent. Concentrations of molybdenum-containing materials are often described in terms of Mo metal concentration. Advantageous concentrations of Mo may range from 25 ppm to 700 ppm or more, and often with a preferred range of 50-200 ppm. Friction modifiers of all types may be used in mixtures with the ashless organic friction modifiers of this disclosure. Often to mixtures of two or more friction modifiers, or mixtures of friction modifier(s) with alternate surface active material(s), are also desirable.

Detergents

Illustrative detergents useful in the lubricating oil compositions of this disclosure include, for example, alkali metal detergents, alkaline earth metal detergents, or mixtures of one or more alkali metal detergents and one or more alkaline earth metal detergents. A typical detergent is an anionic material that contains a long chain hydrophobic portion of the molecule and a smaller anionic or oleophobic hydrophilic portion of the molecule. The anionic portion of the detergent is typically derived from an organic acid such as a sulfur-containing acid, carboxylic acid (e.g., salicylic acid), phosphorus-containing acid, phenol, or mixtures thereof. The counterion is typically an alkaline earth or alkali metal. The detergent can be overbased as described herein.
The detergent is preferably a metal salt of an organic or inorganic acid, a metal salt of a phenol, or mixtures thereof. The metal is preferably selected from an alkali metal, an alkaline earth metal, and mixtures thereof. The organic or inorganic acid is selected from an aliphatic organic or inorganic acid, a cycloaliphatic organic or inorganic acid, an aromatic organic or inorganic acid, and mixtures thereof.
The metal is preferably selected from an alkali metal, an alkaline earth metal, and mixtures thereof. More preferably, the metal is selected from calcium (Ca), magnesium (Mg), and mixtures thereof.
The organic acid or inorganic acid is preferably selected from a sulfur-containing acid, a carboxylic acid, a phosphorus-containing acid, and mixtures thereof.
Preferably, the metal salt of an organic or inorganic acid or the metal salt of a phenol comprises calcium phenate, calcium sulfonate, calcium salicylate, magnesium phenate, magnesium sulfonate, magnesium salicylate, an overbased detergent, and mixtures thereof.
Salts that contain a substantially stochiometric amount of the metal are described as neutral salts and have a total base number (TBN, as measured by ASTM D2896) of from 0 to 80. Many compositions are overbased, containing large amounts of a metal base that is achieved by reacting an excess of a metal compound (a metal hydroxide or oxide, for example) with an acidic gas (such as carbon dioxide). Useful detergents can be neutral, mildly overbased, or highly overbased. These detergents can be used in mixtures of neutral, overbased, highly overbased calcium salicylate, sulfonates, phenates and/or magnesium salicylate, sulfonates, phenates. The TBN ranges can vary from low, medium to high TBN products, including as low as 0 to as high as 600. Preferably the TBN delivered by the detergent is between 60 and 600, more preferably between 200 and 500, and even more preferably between 250 and 450. Mixtures of low, medium, high TBN can be used, along with mixtures of calcium and magnesium metal based detergents, and including sulfonates, phenates, salicylates, and carboxylates. A detergent mixture with a metal ratio of 1, in conjunction of a detergent with a metal ratio of 2, and as high as a detergent with a metal ratio of 5, can be used. Borated detergents can also be used.
Alkaline earth phenates are another useful class of detergent. These detergents can be made by reacting alkaline earth metal hydroxide or oxide (CaO, Ca(OH)₂, BaO, Ba(OH)₂, MgO, Mg(OH)₂, for example) with an alkyl phenol or sulfurized alkylphenol. Useful alkyl groups include straight chain or branched C₁-C₃₀alkyl groups, preferably, C₄-C₂₀or mixtures thereof. Examples of suitable phenols include isobutylphenol, 2-ethylhexylphenol, nonylphenol, dodecyl phenol, and the like. It should be noted that starting alkylphenols may contain more than one alkyl substituent that are each independently straight chain or branched and can be used from 0.5 to 6 weight percent. When a non-sulfurized alkylphenol is used, the sulfurized product may be obtained by methods well known in the art. These methods include heating a mixture of alkylphenol and sulfurizing agent (including elemental sulfur, sulfur halides such as sulfur dichloride, and the like) and then reacting the sulfurized phenol with an alkaline earth metal base.
In accordance with this disclosure, metal salts of carboxylic acids are preferred detergents. These carboxylic acid detergents may be prepared by reacting a basic metal compound with at least one carboxylic acid and removing free water from the reaction product. These compounds may be overbased to produce the desired TBN level. Detergents made from salicylic acid are one preferred class of detergents derived from carboxylic acids. Useful salicylates include long chain alkyl salicylates. One useful family of compositions is of the formula
where R is an alkyl group having 1 to about 30 carbon atoms, n is an integer from 1 to 4, and M is an alkaline earth metal. Preferred R groups are alkyl chains of at least C₁₁, preferably C₁₃or greater. R may be optionally substituted with substituents that do not interfere with the detergent's function. M is preferably, calcium, magnesium, barium, or mixtures thereof. More preferably, M is calcium.
Hydrocarbyl-substituted salicylic acids may be prepared from phenols by the Kolbe reaction (see U.S. Pat. No. 3,595,791). The metal salts of the hydrocarbyl-substituted salicylic acids may be prepared by double decomposition of a metal salt in a polar solvent such as water or alcohol.
Alkaline earth metal phosphates are also used as detergents and are known in the art.
Detergents may be simple detergents or what is known as hybrid or complex detergents. The latter detergents can provide the properties of two detergents without the need to blend separate materials. See U.S. Pat. No. 6,034,039.
Preferred detergents include calcium sulfonates, magnesium sulfonates, calcium salicylates, magnesium salicylates, calcium phenates, magnesium phenates, and other related components (including borated detergents), and mixtures thereof. Preferred mixtures of detergents include magnesium sulfonate and calcium salicylate, magnesium sulfonate and calcium sulfonate, magnesium sulfonate and calcium phenate, calcium phenate and calcium salicylate, calcium phenate and calcium sulfonate, calcium phenate and magnesium salicylate, calcium phenate and magnesium phenate. Overbased detergents are also preferred in terms of having a high TBN in the range of between 200 and 600. A particularly preferred detergent for the lubricating oil compositions of the instant disclosure is a 350 TBN calcium salicylate. A 400 TBN magnesium sulfonate, a 400 TBN calcium sulfonate, a 255 TBN calcium phenate and a 68 TBN calcium salicylate detergent have also provided advantageous performance in the lubricating oil compositions of the instant disclosure.
The detergent concentration in the lubricating oil compositions of this disclosure can range from 0.1 to 20 wt %, or 0.2 to 15 wt %, or 0.3 to 10 wt %, or 0.4 to 8.0 wt %, or 0.5 to 6.0 wt %, or 0.8 to 4 wt %, or 1.0 to 3.0 wt %, or 1.2 to 2.5 wt %, or 1.5 to 2.0 wt %, based on the total weight of the lubricating oil composition.
As used herein, the detergent concentrations are given on an “as delivered” basis. Typically, the active detergent is delivered with a process oil. The “as delivered” detergent typically contains from about 20 weight percent to about 100 weight percent, or from about 40 weight percent to about 60 weight percent, of active detergent in the “as delivered” detergent product.

Lubricating Oil Base Stocks

A wide range of lubricating oil base stocks can be used in conjunction with the at least one organic ashless friction modifier and the at least one over based detergent of the lubricating oils disclosed herein. Such base stocks can be either derived from natural resources or synthetic, including un-refined, refined, or re-refined oils. Un-refined oil base stocks include shale oil obtained directly from retorting operations, petroleum oil obtained directly from primary distillation, and ester oil obtained directly from a natural source (such as plant matters and animal tissues) or directly from a chemical esterification process. Refined oil base stocks are those un-refined base stocks further subjected to one or more purification steps such as solvent extraction, secondary distillation, acid extraction, base extraction, filtration, and percolation to improve the at least one lubricating oil property. Re-refined oil base stocks are obtained by processes analogous to refined oils but using an oil that has been previously used as a feed stock.
Groups I, II, III, IV and V are broad base oil stock categories developed and defined by the American Petroleum Institute (API Publication 1509; www.API.org) to create guidelines for lubricant base oils. Group I base stocks have a viscosity index of between about 80 to 120 and contain greater than about 0.03% sulfur and/or less than about 90% saturates. Group II base stocks have a viscosity index of between about 80 to 120, and contain less than or equal to about 0.03% sulfur and greater than or equal to about 90% saturates. Group III stocks have a viscosity index greater than about 120 and contain less than or equal to about 0.03% sulfur and greater than about 90% saturates. Group IV includes polyalphaolefins (PAO). Group V base stock includes base stocks not included in Groups I-IV. The table below summarizes properties of each of these five groups.


	Base Oil Properties

	Saturates	Sulfur	Viscosity Index

Group I	<90 and/or	>0.03% and	≥80 and <120
Group II	≥90 and	≤0.03% and	≥80 and <120
Group III	≥90 and	≤0.03% and	≥120

	Group IV	polyalphaolefins (PAO)
	Group V	All other base oil stocks not included
		in Groups I, II, III or IV

Natural oils include animal oils, vegetable oils (castor oil and lard oil, for example), and mineral oils. Animal and vegetable oils possessing favorable thermal oxidative stability can be used. Of the natural oils, mineral oils are preferred. Mineral oils vary widely as to their crude source, for example, as to whether they are paraffinic, naphthenic, or mixed paraffinic-naphthenic. Oils derived from coal or shale are also useful. Natural oils vary also as to the method used for their production and purification, for example, their distillation range and whether they are straight run or cracked, hydrorefined, or solvent extracted.
Group II and/or Group III hydroprocessed or hydrocracked base stocks, including synthetic oils such as alkyl aromatics and synthetic esters are also well known base stock oils.
Synthetic oils include hydrocarbon oil. Hydrocarbon oils include oils such as polymerized and interpolymerized olefins (polybutylenes, polypropylenes, propylene isobutylene copolymers, ethylene-olefin copolymers, and ethylene-alphaolefin copolymers, for example). Polyalphaolefin (PAO) oil base stocks are commonly used synthetic hydrocarbon oil. By way of example, PAOs derived from C₈, C₁₀, C₁₂, C₁₄olefins or mixtures thereof may be utilized. See U.S. Pat. Nos. 4,956,122; 4,827,064; and 4,827,073.
The number average molecular weights of the PAOs, which are known materials and generally available on a major commercial scale from suppliers such as ExxonMobil Chemical Company, Chevron Phillips Chemical Company, BP, and others, typically vary from about 250 to about 3,000, although PAO's may be made in viscosities up to about 150 cSt (100° C.). The PAOs are typically comprised of relatively low molecular weight hydrogenated polymers or oligomers of alphaolefins which include, but are not limited to, C₂to about C₃₂alphaolefins with the C₈to about C₁₆alphaolefins, such as 1-octene, 1-decene, 1-dodecene and the like, being preferred. The preferred polyalphaolefins are poly-1-octene, poly-1-decene and poly-1-dodecene and mixtures thereof and mixed olefin-derived polyolefins. However, the dimers of higher olefins in the range of C₁₄to C₁₈may be used to provide low viscosity base stocks of acceptably low volatility. Depending on the viscosity grade and the starting oligomer, the PAOs may be predominantly trimers and tetramers of the starting olefins, with minor amounts of the higher oligomers, having a viscosity range of 1.5 to 12 cSt. PAO fluids of particular use may include 3.0 cSt, 3.4 cSt, and/or 3.6 cSt and combinations thereof. Mixtures of PAO fluids having a viscosity range of 1.5 to approximately 150 cSt or more may be used if desired.
The PAO fluids may be conveniently made by the polymerization of an alphaolefin in the presence of a polymerization catalyst such as the Friedel-Crafts catalysts including, for example, aluminum trichloride, boron trifluoride or complexes of boron trifluoride with water, alcohols such as ethanol, propanol or butanol, carboxylic acids or esters such as ethyl acetate or ethyl propionate. For example the methods disclosed by U.S. Pat. Nos. 4,149,178 or 3,382,291 may be conveniently used herein. Other descriptions of PAO synthesis are found in the following U.S. Pat. Nos. 3,742,082; 3,769,363; 3,876,720; 4,239,930; 4,367,352; 4,413,156; 4,434,408; 4,910,355; 4,956,122; and 5,068,487. The dimers of the C14 to C18 olefins are described in U.S. Pat. No. 4,218,330.
Other useful lubricant oil base stocks include wax isomerate base stocks and base oils, comprising hydroisomerized waxy stocks (e.g. waxy stocks such as gas oils, slack waxes, fuels hydrocracker bottoms, etc.), hydroisomerized Fischer-Tropsch waxes, Gas-to-Liquids (GTL) base stocks and base oils, and other wax isomerate hydroisomerized base stocks and base oils, or mixtures thereof. Fischer-Tropsch waxes, the high boiling point residues of Fischer-Tropsch synthesis, are highly paraffinic hydrocarbons with very low sulfur content. The hydroprocessing used for the production of such base stocks may use an amorphous hydrocracking/hydroisomerization catalyst, such as one of the specialized lube hydrocracking (LHDC) catalysts or a crystalline hydrocracking/hydroisomerization catalyst, preferably a zeolitic catalyst. For example, one useful catalyst is ZSM-48 as described in U.S. Pat. No. 5,075,269, the disclosure of which is incorporated herein by reference in its entirety. Processes for making hydrocracked/hydroisomerized distillates and hydrocracked/hydroisomerized waxes are described, for example, in U.S. Pat. Nos. 2,817,693; 4,975,177; 4,921,594 and 4,897,178 as well as in British Patent Nos. 1,429,494; 1,350,257; 1,440,230 and 1,390,359. Each of the aforementioned patents is incorporated herein in their entirety. Particularly favorable processes are described in European Patent Application Nos. 464546 and 464547, also incorporated herein by reference. Processes using Fischer-Tropsch wax feeds are described in U.S. Pat. Nos. 4,594,172 and 4,943,672, the disclosures of which are incorporated herein by reference in their entirety.
Gas-to-Liquids (GTL) base oils, Fischer-Tropsch wax derived base oils, and other wax-derived hydroisomerized (wax isomerate) base oils be advantageously used in the instant disclosure, and may have useful kinematic viscosities at 100° C. of about 3 cSt to about 50 cSt, preferably about 3 cSt to about 30 cSt, more preferably about 3.5 cSt to about 25 cSt, as exemplified by GTL 4 with kinematic viscosity of about 4.0 cSt at 100° C. and a viscosity index of about 141. These Gas-to-Liquids (GTL) base oils, Fischer-Tropsch wax derived base oils, and other wax-derived hydroisomerized base oils may have useful pour points of about −20° C. or lower, and under some conditions may have advantageous pour points of about −25° C. or lower, with useful pour points of about −30° C. to about −40° C. or lower. Useful compositions of Gas-to-Liquids (GTL) base oils, Fischer-Tropsch wax derived base oils, and wax-derived hydroisomerized base oils are recited in U.S. Pat. Nos. 6,080,301; 6,090,989, and 6,165,949 for example, and are incorporated herein in their entirety by reference.
The hydrocarbyl aromatics can be used as a base oil or base oil component and can be any hydrocarbyl molecule that contains at least about 5% of its weight derived from an aromatic moiety such as a benzenoid moiety or naphthenoid moiety, or their derivatives. These hydrocarbyl aromatics include alkyl benzenes, alkyl naphthalenes, alkyl diphenyl oxides, alkyl naphthols, alkyl diphenyl sulfides, alkylated bis-phenol A, alkylated thiodiphenol, and the like. The aromatic can be mono-alkylated, dialkylated, polyalkylated, and the like. The aromatic can be mono- or poly-functionalized. The hydrocarbyl groups can also be comprised of mixtures of alkyl groups, alkenyl groups, alkynyl, cycloalkyl groups, cycloalkenyl groups and other related hydrocarbyl groups. The hydrocarbyl groups can range from about C₆up to about C₆₀with a range of about C₈to about C₂₀often being preferred. A mixture of hydrocarbyl groups is often preferred, and up to about three such substituents may be present. The hydrocarbyl group can optionally contain sulfur, oxygen, and/or nitrogen containing substituents. The aromatic group can also be derived from natural (petroleum) sources, provided at least about 5% of the molecule is comprised of an above-type aromatic moiety. Viscosities at 100° C. of approximately 3 cSt to about 50 cSt are preferred, with viscosities of approximately 3.4 cSt to about 20 cSt often being more preferred for the hydrocarbyl aromatic component. In one embodiment, an alkyl naphthalene where the alkyl group is primarily comprised of 1-hexadecene is used. Other alkylates of aromatics can be advantageously used. Naphthalene or methyl naphthalene, for example, can be alkylated with olefins such as octene, decene, dodecene, tetradecene or higher, mixtures of similar olefins, and the like. Useful concentrations of hydrocarbyl aromatic in a lubricant oil composition can be about 2% to about 25%, preferably about 4% to about 20%, and more preferably about 4% to about 15%, depending on the application.
Alkylated aromatics such as the hydrocarbyl aromatics of the present disclosure may be produced by well-known Friedel-Crafts alkylation of aromatic compounds. See Friedel-Crafts and Related Reactions, Olah, G. A. (ed.), Inter-science Publishers, New York, 1963. For example, an aromatic compound, such as benzene or naphthalene, is alkylated by an olefin, alkyl halide or alcohol in the presence of a Friedel-Crafts catalyst. See Friedel-Crafts and Related Reactions, Vol. 2, part 1, chapters 14, 17, and 18, See Olah, G. A. (ed.), Inter-science Publishers, New York, 1964. Many homogeneous or heterogeneous, solid catalysts are known to one skilled in the art. The choice of catalyst depends on the reactivity of the starting materials and product quality requirements. For example, strong acids such as AlCl₃, BF₃, or HF may be used. In some cases, milder catalysts such as FeCl₃or SnCl₄are preferred. Newer alkylation technology uses zeolites or solid super acids.
Esters comprise a useful base stock. Additive solvency and seal compatibility characteristics may be secured by the use of esters such as the esters of dibasic acids with monoalkanols and the polyol esters of monocarboxylic acids. Esters of the former type include, for example, the esters of dicarboxylic acids such as phthalic acid, succinic acid, alkyl succinic acid, alkenyl succinic acid, maleic acid, azelaic acid, suberic acid, sebacic acid, fumaric acid, adipic acid, linoleic acid dimer, malonic acid, alkyl malonic acid, alkenyl malonic acid, etc., with a variety of alcohols such as butyl alcohol, hexyl alcohol, dodecyl alcohol, 2-ethylhexyl alcohol, etc. Specific examples of these types of esters include dibutyl adipate, di(2-ethylhexyl) sebacate, di-n-hexyl fumarate, dioctyl sebacate, diisooctyl azelate, diisodecyl azelate, dioctyl phthalate, didecyl phthalate, dieicosyl sebacate, etc.
Particularly useful synthetic esters are those which are obtained by reacting one or more polyhydric alcohols, preferably the hindered polyols (such as the neopentyl polyols, e.g., neopentyl glycol, trimethylol ethane, 2-methyl-2-propyl-1,3-propanediol, trimethylol propane, pentaerythritol and dipentaerythritol) with alkanoic acids containing at least about 4 carbon atoms, preferably C5 to C30 acids such as saturated straight chain fatty acids including caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachic acid, and behenic acid, or the corresponding branched chain fatty acids or unsaturated fatty acids such as oleic acid, or mixtures of any of these materials.
Suitable synthetic ester components include the esters of trimethylol propane, trimethylol butane, trimethylol ethane, pentaerythritol and/or dipentaerythritol with one or more monocarboxylic acids containing from about 5 to about 10 carbon atoms. These esters are widely available commercially, for example, the Mobil P-41 and P-51 esters of ExxonMobil Chemical Company.
Also useful are esters derived from renewable material such as coconut, palm, rapeseed, soy, sunflower and the like. These esters may be monoesters, di-esters, polyol esters, complex esters, or mixtures thereof. These esters are widely available commercially, for example, the Esterex NP 343 ester of ExxonMobil Chemical Company.
More particularly, branched polyol esters comprise a useful base stock of this disclosure. The branched polyol esters are obtained by reacting one or more polyhydric alcohols, preferably the hindered polyols (such as the neopentyl polyols, e.g., neopentyl glycol, trimethylol ethane, 2-methyl-2-propyl-1,3-propanediol, trimethylol propane, pentaerythritol and dipentaerythritol) with single or mixed branched mono-carboxylic acids containing at least about 4 carbon atoms, preferably C₅to C₃₀branched mono-carboxylic acids including 2,2-dimethyl propionic acid (neopentanoic acid), neoheptanoic acid, neooctanoic acid, neononanoic acid, iso-hexanoic acid, neodecanoic acid, 2-ethyl hexanoic acid (2EH), 3,5,5-trimethyl hexanoic acid (TMH), isoheptanoic acid, isooctanoic acid, isononanoic acid, isodecanoic acid, or mixtures of any of these materials. These branched polyol esters include fully converted and partially converted polyol esters.
Particularly useful polyols include, for example, neopentyl glycol, 2,2-dimethylol butane, trimethylol ethane, trimethylol propane, trimethylol butane, mono-pentaerythritol, technical grade pentaerythritol, di-pentaerythritol, tri-pentaerythritol, ethylene glycol, propylene glycol and polyalkylene glycols (e.g., polyethylene glycols, polypropylene glycols, 1,4-butanediol, sorbitol and the like, 2-methylpropanediol, polybutylene glycols, etc., and blends thereof such as a polymerized mixture of ethylene glycol and propylene glycol). The most preferred alcohols are technical grade (e.g., approximately 88% mono-, 10% di- and 1-2% tri-pentaerythritol) pentaerythritol, mono-pentaerythritol, di-pentaerythritol, neopentyl glycol and trimethylol propane.
Particularly useful branched mono-carboxylic acids include, for example, 2,2-dimethyl propionic acid (neopentanoic acid), neoheptanoic acid, neooctanoic acid, neononanoic acid, iso-hexanoic acid, neodecanoic acid, 2-ethyl hexanoic acid (2EH), 3,5,5-trimethyl hexanoic acid (TMH), isoheptanoic acid, isooctanoic acid, isononanoic acid, isodecanoic acid, or mixtures of any of these materials. One especially preferred branched acid is 3,5,5-trimethyl hexanoic acid. The term “neo” as used herein refers to a trialkyl acetic acid, i.e., an acid which is triply substituted at the alpha carbon with alkyl groups.
Preferably, the branched polyol ester is derived from a polyhydric alcohol and a branched mono-carboxylic acid. In particular, the branched polyol ester is obtained by reacting one or more polyhydric alcohols with one or more branched mono-carboxylic acids containing at least about 4 carbon atoms.
Preferred branched polyol esters useful in this disclosure include, for example, mono-pentaerythritol ester of branched mono-carboxylic acids, di-pentaerythritol ester of branched mono-carboxylic acids, trimethylolpropane ester of C8-C10 acids, and the like.
Other synthetic esters that can be useful in this disclosure are those which are obtained by reacting one or more polyhydric alcohols, preferably the hindered polyols (such as the neopentyl polyols, e.g., neopentyl glycol, trimethylol ethane, 2-methyl-2-propyl-1,3-propanediol, trimethylol propane, pentaerythritol and dipentaerythritol) with mono carboxylic acids containing at least about 4 carbon atoms, preferably branched C₅to C₃₀acids including caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachic acid, and behenic acid, or the corresponding branched chain fatty acids or unsaturated fatty acids such as oleic acid, or mixtures of any of these materials.
Other ester base oils useful in this disclosure include adipate esters. The dialkyl adipate ester is derived from adipic acid and a branched alkyl alcohol.
Mixtures of branched polyol ester base stocks with other lubricating oil base stocks (e.g., Groups I, II, III, IV and V base stocks) may be useful in the lubricating oil formulations of this disclosure.
The branched polyol ester can be present in an amount of from about 1 to about 50 weight percent, or from about 5 to about 45 weight percent, or from about 10 to about 40 weight percent, or from about 15 to about 35 weight percent, or from about 20 to about 30 weight percent, based on the total weight of the formulated oil.
Engine oil formulations containing renewable esters are included in this disclosure. For such formulations, the renewable content of the ester is typically greater than about 70 weight percent, preferably more than about 80 weight percent and most preferably more than about 90 weight percent.
Other useful fluids of lubricating viscosity include non-conventional or unconventional base stocks that have been processed, preferably catalytically, or synthesized to provide high performance lubrication characteristics.
Non-conventional or unconventional base stocks/base oils include one or more of a mixture of base stock(s) derived from one or more Gas-to-Liquids (GTL) materials, as well as isomerate/isodewaxate base stock(s) derived from natural wax or waxy feeds, mineral and or non-mineral oil waxy feed stocks such as slack waxes, natural waxes, and waxy stocks such as gas oils, waxy fuels hydrocracker bottoms, waxy raffinate, hydrocrackate, thermal crackates, or other mineral, mineral oil, or even non-petroleum oil derived waxy materials such as waxy materials received from coal liquefaction or shale oil, and mixtures of such base stocks.
GTL materials are materials that are derived via one or more synthesis, combination, transformation, rearrangement, and/or degradation/deconstructive processes from gaseous carbon-containing compounds, hydrogen-containing compounds and/or elements as feed stocks such as hydrogen, carbon dioxide, carbon monoxide, water, methane, ethane, ethylene, acetylene, propane, propylene, propyne, butane, butylenes, and butynes. GTL base stocks and/or base oils are GTL materials of lubricating viscosity that are generally derived from hydrocarbons; for example, waxy synthesized hydrocarbons, that are themselves derived from simpler gaseous carbon-containing compounds, hydrogen-containing compounds and/or elements as feed stocks. GTL base stock(s) and/or base oil(s) include oils boiling in the lube oil boiling range (1) separated/fractionated from synthesized GTL materials such as, for example, by distillation and subsequently subjected to a final wax processing step which involves either or both of a catalytic dewaxing process, or a solvent dewaxing process, to produce lube oils of reduced/low pour point; (2) synthesized wax isomerates, comprising, for example, hydrodewaxed or hydroisomerized cat and/or solvent dewaxed synthesized wax or waxy hydrocarbons; (3) hydrodewaxed or hydroisomerized cat and/or solvent dewaxed Fischer-Tropsch (F-T) material (i.e., hydrocarbons, waxy hydrocarbons, waxes and possible analogous oxygenates); preferably hydrodewaxed or hydroisomerized/followed by cat and/or solvent dewaxing dewaxed F-T waxy hydrocarbons, or hydrodewaxed or hydroisomerized/followed by cat (or solvent) dewaxing dewaxed, F-T waxes, or mixtures thereof.
GTL base stock(s) and/or base oil(s) derived from GTL materials, especially, hydrodewaxed or hydroisomerized/followed by cat and/or solvent dewaxed wax or waxy feed, preferably F-T material derived base stock(s) and/or base oil(s), are characterized typically as having kinematic viscosities at 100° C. of from about 2 mm²/s to about 50 mm²/s (ASTM D445). They are further characterized typically as having pour points of −5° C. to about −40° C. or lower (ASTM D97). They are also characterized typically as having viscosity indices of about 80 to about 140 or greater (ASTM D2270).
In addition, the GTL base stock(s) and/or base oil(s) are typically highly paraffinic (>90% saturates), and may contain mixtures of monocycloparaffins and multicycloparaffins in combination with non-cyclic isoparaffins. The ratio of the naphthenic (i.e., cycloparaffin) content in such combinations varies with the catalyst and temperature used. Further, GTL base stock(s) and/or base oil(s) typically have very low sulfur and nitrogen content, generally containing less than about 10 ppm, and more typically less than about 5 ppm of each of these elements. The sulfur and nitrogen content of GTL base stock(s) and/or base oil(s) obtained from F-T material, especially F-T wax, is essentially nil. In addition, the absence of phosphorus and aromatics make this materially especially suitable for the formulation of low SAP products.
The term GTL base stock and/or base oil and/or wax isomerate base stock and/or base oil is to be understood as embracing individual fractions of such materials of wide viscosity range as recovered in the production process, mixtures of two or more of such fractions, as well as mixtures of one or two or more low viscosity fractions with one, two or more higher viscosity fractions to produce a blend wherein the blend exhibits a target kinematic viscosity.
The GTL material, from which the GTL base stock(s) and/or base oil(s) is/are derived is preferably an F-T material (i.e., hydrocarbons, waxy hydrocarbons, wax).
Base oils for use in the formulated lubricating oils useful in the present disclosure are any of the variety of oils corresponding to API Group I, Group II, Group III, Group IV, and Group V oils and mixtures thereof, preferably API Group II, Group III, Group IV, and Group V oils and mixtures thereof, more preferably the Group III to Group V base oils due to their exceptional volatility, stability, viscometric and cleanliness features. Minor quantities of Group I stock, such as the amount used to dilute additives for blending into formulated lube oil products, can be tolerated but should be kept to a minimum, i.e. amounts only associated with their use as diluent/carrier oil for additives used on an “as-received” basis. Even in regard to the Group II stocks, it is preferred that the Group II stock be in the higher quality range associated with that stock, i.e. a Group II stock having a viscosity index in the range 100<VI<120. Groups II and III base stocks can be included in the lubricating oil formulations of this disclosure, but preferably only those with high quality, e.g., those having a VI from 100 to 120. Group IV and V base stocks, preferably those of high quality, are desirably included into the lubricating oil formulations of this disclosure.
The base oil or base stock constitutes the major component or major amount of the lubricating oil compositions of the present disclosure and typically is present in an amount ranging from about 5 to about 99 weight percent, or about 7 to about 95 weight percent, or about 10 to about 90 weight percent, or about 20 to about 80 weight percent, preferably from about 70 to about 95 weight percent, and more preferably from about 85 to about 95 weight percent, based on the total weight of the composition. The base oil or base stock may be selected from any of the synthetic or natural oils typically used as crankcase lubricating oils for spark-ignited and compression-ignited engines.
The base oil or base stock conveniently has a kinematic viscosity, according to ASTM standards, of about 2.5 cSt to about 12 cSt (or mm²/s) at 100° C. and preferably of about 2.5 cSt to about 9 cSt (or mm²/s) at 100° C.
Mixtures of synthetic and natural base oils may be used if desired. Bi-modal mixtures of Group I, II, III, IV, and/or V base stocks may be used if desired. A second base stock or co-base stock may be also optionally incorporated into the lubricating oil compositions of this disclosure in an amount ranging from about 5 to about 80 weight percent, or about 10 to about 60 weight percent, or about 15 to about 50 weight percent, or about 20 to about 40 weight percent, or from about 25 to about 35 weight percent.
Other Lubricating Oil Additives of the Lubricating Oil Compositions of this Disclosure
The lubricating oil compositions (preferably lubricating oil formulations) of this disclosure may additionally contain one or more of the commonly used other lubricating oil performance additives including but not limited to dispersants, viscosity modifiers, antiwear additives, corrosion inhibitors, rust inhibitors, metal deactivators, extreme pressure additives, anti-seizure agents, wax modifiers, fluid-loss additives, seal compatibility agents, lubricity agents, anti-staining agents, chromophoric agents, defoamants, demulsifiers, densifiers, wetting agents, gelling agents, tackiness agents, colorants, and others. For a review of many commonly used additives and the quantities used, see: (i) Klamann in Lubricants and Related Products, Verlag Chemie, Deerfield Beach, Fla.; ISBN 0-89573-177-0; (ii) “Lubricant Additives,” M. W. Ranney, published by Noyes Data Corporation of Parkridge, N J (1973); (iii) “Synthetics, Mineral Oils, and Bio-Based Lubricants,” Edited by L. R. Rudnick, CRC Taylor and Francis, 2006, ISBN 1-57444-723-8; (iv) “Lubrication Fundamentals”, J. G. Wills, Marcel Dekker Inc., (New York, 1980); (v) Synthetic Lubricants and High-Performance Functional Fluids, 2nd Ed., Rudnick and Shubkin, Marcel Dekker Inc., (New York, 1999); and (vi) “Polyalphaolefins,” L. R. Rudnick, Chemical Industries (Boca Raton, Fla., United States) (2006), 111 (Synthetics, Mineral Oils, and Bio-Based Lubricants), 3-36. Reference is also made to: (a) U.S. Pat. No. 7,704,930 B2; (b) U.S. Pat. No. 9,458,403 B2, Column 18, line 46 to Column 39, line 68; (c) U.S. Pat. No. 9,422,497 B2, Column 34, line 4 to Column 40, line 55; and (d) U.S. Pat. No. 8,048,833 B2, Column 17, line 48 to Column 27, line 12, the disclosures of which are incorporated herein in its entirety. These additives are commonly delivered with varying amounts of diluent oil that may range from 5 wt % to 50 wt % based on the total weight of the additive package before incorporation into the formulated oil.
Further details of the other lubricating oil additives useful in the lubricating oil compositions of this disclosure are as follows:

Viscosity Modifiers

Viscosity modifiers provide lubricants with high and low temperature operability. These additives impart shear stability at elevated temperatures and acceptable viscosity at low temperatures.
Non-limiting exemplary viscosity modifiers for the inventive lubricating oils are as follows: high molecular weight hydrocarbons, polyesters and viscosity modifier dispersants that function as both a viscosity modifier and a dispersant. Typical molecular weights of these polymers are between about 10,000 to 1,500,000, more typically about 20,000 to 1,200,000, and even more typically between about 50,000 and 1,000,000.
Other examples of suitable viscosity modifiers are linear or star-shaped polymers and copolymers of methacrylate, butadiene, olefins, or alkylated styrenes. Polyisobutylene is a commonly used viscosity modifier. Another suitable viscosity modifier is polymethacrylate (copolymers of various chain length alkyl methacrylates, for example), some formulations of which also serve as pour point depressants. Other suitable viscosity modifiers include copolymers of ethylene and propylene, hydrogenated block copolymers of styrene and isoprene, and polyacrylates (copolymers of various chain length acrylates, for example). Specific examples include styrene-isoprene or styrene-butadiene based polymers of 50,000 to 200,000 molecular weight.
Olefin copolymers are commercially available from Chevron Oronite Company LLC under the trade designation “PARATONE®” (such as “PARATONE® 8921” and “PARATONE® 8941”); from Afton Chemical Corporation under the trade designation “HiTEC®” (such as “HiTEC® 5850B”; and from The Lubrizol Corporation under the trade designation “Lubrizol® 7067C”. Hydrogenated polyisoprene star polymers are commercially available from Infineum International Limited, e.g., under the trade designation “SV200” and “SV600”. Hydrogenated diene-styrene block copolymers are commercially available from Infineum International Limited, e.g., under the trade designation “SV 50”.
The polymethacrylate or polyacrylate polymers can be linear polymers which are available from Evonik Industries under the trade designation “Viscoplex®” (e.g., Viscoplex 6-954) or star polymers which are available from Lubrizol Corporation under the trade designation Asteric™ (e.g., Lubrizol 87708 and Lubrizol 87725).
Illustrative vinyl aromatic-containing polymers as viscosity modifiers useful in this disclosure may be derived predominantly from vinyl aromatic hydrocarbon monomer. Illustrative vinyl aromatic-containing copolymers useful in this disclosure may be represented by the following general formula:
A−B
wherein A is a polymeric block derived predominantly from vinyl aromatic hydrocarbon monomer, and B is a polymeric block derived predominantly from conjugated diene monomer.
In another embodiment of this disclosure, the at least one viscosity modifier may be used in an amount of less than about 20 weight percent, or less than about 15 weight percent, or less than about 10 weight percent, or less than about 7 weight percent, or less than about 5 weight percent, and in certain instances, may be used at less than 2 weight percent, or less than about 1 weight percent, or less than about 0.5 weight percent, based on the total weight of the formulated oil or lubricating engine oil. The preferred range for the at least one viscosity modifier is from 5 to 20 wt % of the formulated oil.
Viscosity modifiers are typically added as concentrates, in large amounts of diluent oil. As used herein, the viscosity modifier concentrations are given on an “as delivered” basis. Typically, the active polymer is delivered with a diluent oil. The “as delivered” viscosity modifier typically contains from 20 weight percent to 75 weight percent of an active polymer for polymethacrylate or polyacrylate polymers, or from 8 weight percent to 20 weight percent of an active polymer for olefin copolymers, hydrogenated polyisoprene star polymers, or hydrogenated diene-styrene block copolymers, in the “as delivered” polymer concentrate.

Antiwear Additives

A metal alkylthiophosphate and more particularly a metal dialkyl dithio phosphate in which the metal constituent is zinc, or zinc dialkyl dithio phosphate (ZDDP) can be a useful component of the lubricating oils of this disclosure. ZDDP can be derived from primary alcohols, secondary alcohols or mixtures thereof. ZDDP compounds generally are of the formula
Zn[SP(S)(OR¹)(OR²)]₂
where R¹and R²are C₁-C₁₈alkyl groups, preferably C₂-C₁₂alkyl groups. These alkyl groups may be straight chain or branched. Alcohols used in the ZDDP can be 2-propanol, butanol, secondary butanol, pentanols, hexanols such as 4-methyl-2-pentanol, n-hexanol, n-octanol, 2-ethyl hexanol, alkylated phenols, and the like. Mixtures of secondary alcohols or of primary and secondary alcohol can be preferred. Alkyl aryl groups may also be used.
Preferable zinc dithiophosphates which are commercially available include secondary zinc dithiophosphates such as those available from for example, The Lubrizol Corporation under the trade designations “LZ 677A”, “LZ 1095” and “LZ 1371”, from for example Chevron Oronite under the trade designation “OLOA 262” and from for example Afton Chemical under the trade designation “HITEC 7169”.
The ZDDP is typically used in amounts of from about 0.4 weight percent to about 1.2 weight percent, preferably from about 0.5 weight percent to about 1.0 weight percent, and more preferably from about 0.6 weight percent to about 0.8 weight percent, based on the total weight of the lubricating oil, although more or less can often be used advantageously. Preferably, the ZDDP is a secondary ZDDP and present in an amount of from about 0.6 to 1.0 weight percent of the total weight of the lubricating oil.
Low phosphorus engine oil formulations are included in this disclosure. For such formulations, the phosphorus content is typically less than about 0.12 weight percent preferably less than about 0.10 weight percent and most preferably less than about 0.085 weight percent.

Dispersants

During engine operation, oil-insoluble oxidation byproducts are produced. Dispersants help keep these byproducts in solution, thus diminishing their deposition on metal surfaces. Dispersants used in the formulation of the lubricating oil may be ashless or ash-forming in nature. Preferably, the dispersant is ashless. So called ashless dispersants are organic materials that form substantially no ash upon combustion. For example, non-metal-containing or borated metal-free dispersants are considered ashless. In contrast, metal-containing detergents discussed herein form ash upon combustion.
Suitable dispersants typically contain a polar group attached to a relatively high molecular weight hydrocarbon chain. The polar group typically contains at least one element of nitrogen, oxygen, or phosphorus. Typical hydrocarbon chains contain 50 to 400 carbon atoms.
A particularly useful class of dispersants are the (poly)alkenylsuccinic derivatives, typically produced by the reaction of a long chain hydrocarbyl substituted succinic compound, usually a hydrocarbyl substituted succinic anhydride, with a polyhydroxy or polyamino compound. The long chain hydrocarbyl group constituting the oleophilic portion of the molecule which confers solubility in the oil, is normally a polyisobutylene group. Many examples of this type of dispersant are well known commercially and in the literature. Exemplary U.S. patents describing such dispersants are U.S. Pat. Nos. 3,172,892; 3,215,707; 3,219,666; 3,316,177; 3,341,542; 3,444,170; 3,454,607; 3,541,012; 3,630,904; 3,632,511; 3,787,374 and 4,234,435. Other types of dispersant are described in U.S. Pat. Nos. 3,036,003; 3,200,107; 3,254,025; 3,275,554; 3,438,757; 3,454,555; 3,565,804; 3,413,347; 3,697,574; 3,725,277; 3,725,480; 3,726,882; 4,454,059; 3,329,658; 3,449,250; 3,519,565; 3,666,730; 3,687,849; 3,702,300; 4,100,082; 5,705,458. A further description of dispersants may be found, for example, in European Patent Application No. 471 071, to which reference is made for this purpose.
Hydrocarbyl-substituted succinic acid and hydrocarbyl-substituted succinic anhydride derivatives are useful dispersants. In particular, succinimide, succinate esters, or succinate ester amides prepared by the reaction of a hydrocarbon-substituted succinic acid compound preferably having at least 50 carbon atoms in the hydrocarbon substituent, with at least one equivalent of an alkylene amine are particularly useful.
Succinimides are formed by the condensation reaction between hydrocarbyl substituted succinic anhydrides and amines. Molar ratios can vary depending on the polyamine. For example, the molar ratio of hydrocarbyl substituted succinic anhydride to TEPA can vary from about 1:1 to about 5:1. Representative examples are shown in U.S. Pat. Nos. 3,087,936; 3,172,892; 3,219,666; 3,272,746; 3,322,670; and 3,652,616, 3,948,800; and Canada Patent No. 1,094,044.
Succinate esters are formed by the condensation reaction between hydrocarbyl substituted succinic anhydrides and alcohols or polyols. Molar ratios can vary depending on the alcohol or polyol used. For example, the condensation product of a hydrocarbyl substituted succinic anhydride and pentaerythritol is a useful dispersant.
Succinate ester amides are formed by condensation reaction between hydrocarbyl substituted succinic anhydrides and alkanol amines. For example, suitable alkanol amines include ethoxylated polyalkylpolyamines, propoxylated polyalkylpolyamines and polyalkenylpolyamines such as polyethylene polyamines. One example is propoxylated hexamethylenediamine. Representative examples are shown in U.S. Pat. No. 4,426,305.
The molecular weight of the hydrocarbyl substituted succinic anhydrides used in the preceding paragraphs will typically range between 800 and 2,500 or more. The above products can be post-reacted with various reagents such as sulfur, oxygen, formaldehyde, carboxylic acids such as oleic acid. The above products can also be post reacted with boron compounds such as boric acid, borate esters or highly borated dispersants, to form borated dispersants generally having from about 0.1 to about 5 moles of boron per mole of dispersant reaction product.
Mannich base dispersants are made from the reaction of alkylphenols, formaldehyde, and amines. See U.S. Pat. No. 4,767,551, which is incorporated herein by reference. Process aids and catalysts, such as oleic acid and sulfonic acids, can also be part of the reaction mixture. Molecular weights of the alkylphenols range from 800 to 2,500. Representative examples are shown in U.S. Pat. Nos. 3,697,574; 3,703,536; 3,704,308; 3,751,365; 3,756,953; 3,798,165; and 3,803,039.
Typical high molecular weight aliphatic acid modified Mannich condensation products useful in this disclosure can be prepared from high molecular weight alkyl-substituted hydroxyaromatics or HNR₂group-containing reactants.
Hydrocarbyl substituted amine ashless dispersant additives are well known to one skilled in the art; see, for example, U.S. Pat. Nos. 3,275,554; 3,438,757; 3,565,804; 3,755,433, 3,822,209, and 5,084,197.
Preferred dispersants include borated and non-borated succinimides, including those derivatives from mono-succinimides, bis-succinimides, and/or mixtures of mono- and bis-succinimides, wherein the hydrocarbyl succinimide is derived from a hydrocarbylene group such as polyisobutylene having a Mn of from about 500 to about 5000, or from about 1000 to about 3000, or about 1000 to about 2000, or a mixture of such hydrocarbylene groups, often with high terminal vinylic groups. Other preferred dispersants include succinic acid-esters and amides, alkylphenol-polyamine-coupled Mannich adducts, their capped derivatives, and other related components.
Polymethacrylate or polyacrylate derivatives are another class of dispersants. These dispersants are typically prepared by reacting a nitrogen containing monomer and a methacrylic or acrylic acid esters containing 5-25 carbon atoms in the ester group. Representative examples are shown in U.S. Pat. Nos. 2,100,993, and 6,323,164. Polymethacrylate and polyacrylate dispersants are normally used as multifunctional viscosity modifiers. The lower molecular weight versions can be used as lubricant dispersants or fuel detergents.
Illustrative preferred dispersants useful in this disclosure include those derived from polyalkenyl-substituted mono- or dicarboxylic acid, anhydride or ester, which dispersant has a polyalkenyl moiety with a number average molecular weight of at least 900 and from greater than 1.3 to 1.7, preferably from greater than 1.3 to 1.6, most preferably from greater than 1.3 to 1.5, functional groups (mono- or dicarboxylic acid producing moieties) per polyalkenyl moiety (a medium functionality dispersant). Functionality (F) can be determined according to the following formula:
F=(SAP×M_n)/((112,200×A.I.)−(SAP×98))
wherein SAP is the saponification number (i.e., the number of milligrams of KOH consumed in the complete neutralization of the acid groups in one gram of the succinic-containing reaction product, as determined according to ASTM D94); M_nis the number average molecular weight of the starting olefin polymer; and A.I. is the percent active ingredient of the succinic-containing reaction product (the remainder being unreacted olefin polymer, succinic anhydride and diluent).
The polyalkenyl moiety of the dispersant may have a number average molecular weight of at least 900, suitably at least 1500, preferably between 1800 and 3000, such as between 2000 and 2800, more preferably from about 2100 to 2500, and most preferably from about 2200 to about 2400. The molecular weight of a dispersant is generally expressed in terms of the molecular weight of the polyalkenyl moiety. This is because the precise molecular weight range of the dispersant depends on numerous parameters including the type of polymer used to derive the dispersant, the number of functional groups, and the type of nucleophilic group employed.
Polymer molecular weight, specifically M_n, can be determined by various known techniques. One convenient method is gel permeation chromatography (GPC), which additionally provides molecular weight distribution information (see W. W. Yau, J. J. Kirkland and D. D. Bly, “Modern Size Exclusion Liquid Chromatography”, John Wiley and Sons, New York, 1979). Another useful method for determining molecular weight, particularly for lower molecular weight polymers, is vapor pressure osmometry (e.g., ASTM D3592).
The polyalkenyl moiety in a dispersant preferably has a narrow molecular weight distribution (MWD), also referred to as polydispersity, as determined by the ratio of weight average molecular weight (M_w) to number average molecular weight (M_n). Polymers having a M_w/M_nof less than 2.2, preferably less than 2.0, are most desirable. Suitable polymers have a polydispersity of from about 1.5 to 2.1, preferably from about 1.6 to about 1.8.
Suitable polyalkenes employed in the formation of the dispersants include homopolymers, interpolymers or lower molecular weight hydrocarbons. One family of such polymers comprise polymers of ethylene and/or at least one C₃to C₂alpha-olefin having the formula H₂C═CHR¹wherein R¹is a straight or branched chain alkyl radical comprising 1 to 26 carbon atoms and wherein the polymer contains carbon-to-carbon unsaturation, and a high degree of terminal ethenylidene unsaturation. Preferably, such polymers comprise interpolymers of ethylene and at least one alpha-olefin of the above formula, wherein R¹is alkyl of from 1 to 18 carbon atoms, and more preferably is alkyl of from 1 to 8 carbon atoms, and more preferably still of from 1 to 2 carbon atoms.
Another useful class of polymers is polymers prepared by cationic polymerization of monomers such as isobutene and styrene. Common polymers from this class include polyisobutenes obtained by polymerization of a C₄refinery stream having a butene content of 35 to 75% by wt., and an isobutene content of 30 to 60% by wt. A preferred source of monomer for making poly-n-butenes is petroleum feedstreams such as Raffinate II. These feedstocks are disclosed in the art such as in U.S. Pat. No. 4,952,739. A preferred embodiment utilizes polyisobutylene prepared from a pure isobutylene stream or a Raffinate I stream to prepare reactive isobutylene polymers with terminal vinylidene olefins. Polyisobutene polymers that may be employed are generally based on a polymer chain of from 1500 to 3000.
The dispersant(s) are preferably non-polymeric (e.g., mono- or bis-succinimides). Such dispersants can be prepared by conventional processes such as disclosed in U.S. Patent Application Publication No. 2008/0020950, the disclosure of which is incorporated herein by reference.
The dispersant(s) can be borated by conventional means, as generally disclosed in U.S. Pat. Nos. 3,087,936, 3,254,025 and 5,430,105.
Such dispersants may be used in an amount of about 0.01 to 20 weight percent or 0.01 to 10 weight percent, preferably about 0.5 to 8 weight percent, or more preferably 0.5 to 4 weight percent. Or such dispersants may be used in an amount of about 2 to 12 weight percent, preferably about 4 to 10 weight percent, or more preferably 6 to 9 weight percent. On an active ingredient basis, such additives may be used in an amount of about 0.06 to 14 weight percent, preferably about 0.3 to 6 weight percent. The hydrocarbon portion of the dispersant atoms can range from C₆₀to C₁₀₀₀, or from C₇₀to C₃₀₀, or from C₇₀to C₂₀₀. These dispersants may contain both neutral and basic nitrogen, and mixtures of both. Dispersants can be end-capped by borates and/or cyclic carbonates. Nitrogen content in the finished oil can vary from about 200 ppm by weight to about 2000 ppm by weight, preferably from about 200 ppm by weight to about 1200 ppm by weight. Basic nitrogen can vary from about 100 ppm by weight to about 1000 ppm by weight, preferably from about 100 ppm by weight to about 600 ppm by weight.
As used herein, the dispersant concentrations are given on an “as delivered” basis. Typically, the active dispersant is delivered with a process oil. The “as delivered” dispersant typically contains from about 20 weight percent to about 80 weight percent, or from about 40 weight percent to about 60 weight percent, of active dispersant in the “as delivered” dispersant product.

Antioxidants

Antioxidants retard the oxidative degradation of base oils during service. Such degradation may result in deposits on metal surfaces, the presence of sludge, or a viscosity increase in the lubricant. One skilled in the art knows a wide variety of oxidation inhibitors that are useful in lubricating oil compositions. See, Klamann in Lubricants and Related Products, op cite, and U.S. Pat. Nos. 4,798,684 and 5,084,197, for example.
Useful antioxidants include hindered phenols. These phenolic antioxidants may be ashless (metal-free) phenolic compounds or neutral or basic metal salts of certain phenolic compounds. Typical phenolic antioxidant compounds are the hindered phenolics which are the ones which contain a sterically hindered hydroxyl group, and these include those derivatives of dihydroxy aryl compounds in which the hydroxyl groups are in the o- or p-position to each other. Typical phenolic antioxidants include the hindered phenols substituted with C₆+ alkyl groups and the alkylene coupled derivatives of these hindered phenols. Examples of phenolic materials of this type 2-t-butyl-4-heptyl phenol; 2-t-butyl-4-octyl phenol; 2-t-butyl-4-dodecyl phenol; 2,6-di-t-butyl-4-heptyl phenol; 2,6-di-t-butyl-4-dodecyl phenol; 2-methyl-6-t-butyl-4-heptyl phenol; and 2-methyl-6-t-butyl-4-dodecyl phenol. Other useful hindered mono-phenolic antioxidants may include for example hindered 2,6-di-alkyl-phenolic proprionic ester derivatives. Bis-phenolic antioxidants may also be advantageously used in combination with the instant disclosure. Examples of ortho-coupled phenols include: 2,2′-bis(4-heptyl-6-t-butyl-phenol); 2,2′-bis(4-octyl-6-t-butyl-phenol); and 2,2′-bis(4-dodecyl-6-t-butyl-phenol). Para-coupled bisphenols include for example 4,4′-bis(2,6-di-t-butyl phenol) and 4,4′-methylene-bis(2,6-di-t-butyl phenol).
Effective amounts of one or more catalytic antioxidants may also be used. The catalytic antioxidants comprise an effective amount of a) one or more oil soluble polymetal organic compounds; and, effective amounts of b) one or more substituted N,N′-diaryl-o-phenylenediamine compounds or c) one or more hindered phenol compounds; or a combination of both b) and c). Catalytic antioxidants are more fully described in U.S. Pat. No. 8,048,833, herein incorporated by reference in its entirety.
Non-phenolic oxidation inhibitors which may be used include aromatic amine antioxidants and these may be used either as such or in combination with phenolics. Typical examples of non-phenolic antioxidants include: alkylated and non-alkylated aromatic amines such as aromatic monoamines of the formula R⁸R⁹R¹⁰N where R⁸is an aliphatic, aromatic or substituted aromatic group, R⁹is an aromatic or a substituted aromatic group, and R¹⁰is H, alkyl, aryl or R¹¹S(O)_XR¹²where R¹¹is an alkylene, alkenylene, or aralkylene group, R¹²is a higher alkyl group, or an alkenyl, aryl, or alkaryl group, and x is 0, 1 or 2. The aliphatic group R⁸may contain from 1 to about 20 carbon atoms, and preferably contains from about 6 to 12 carbon atoms. The aliphatic group is a saturated aliphatic group. Preferably, both R⁸and R⁹are aromatic or substituted aromatic to groups, and the aromatic group may be a fused ring aromatic group such as naphthyl. Aromatic groups R⁸and R⁹may be joined together with other groups such as S.
Typical aromatic amines antioxidants have alkyl substituent groups of at least about 6 carbon atoms. Examples of aliphatic groups include hexyl, heptyl, octyl, nonyl, and decyl. Generally, the aliphatic groups will not contain more than about 14 carbon atoms. The general types of amine antioxidants useful in the present compositions include diphenylamines, phenyl naphthylamines, phenothiazines, imidodibenzyls and diphenyl phenylene diamines. Mixtures of two or more aromatic amines are also useful. Polymeric amine antioxidants can also be used. Particular examples of aromatic amine antioxidants useful in the present disclosure include: p,p′-dioctyldiphenylamine; t-octylphenyl-alpha-naphthylamine; phenyl-alphanaphthylamine; and p-octylphenyl-alpha-naphthylamine.
Sulfurized alkyl phenols and alkali or alkaline earth metal salts thereof also are useful antioxidants.
Preferred antioxidants include hindered phenols, arylamines. These antioxidants may be used individually by type or in combination with one another. Such additives may be used in an amount of about 0.01 to 5 weight percent, preferably about 0.01 to 1.5 weight percent, more preferably zero to less than 1.5 weight percent, more preferably zero to less than 1 weight percent.

Pour Point Depressants (PPDs)

Conventional pour point depressants (also known as lube oil flow improvers) may be added to the compositions of the present disclosure if desired. These pour point depressant may be added to lubricating compositions of the present disclosure to lower the minimum temperature at which the fluid will flow or can be poured. Examples of suitable pour point depressants include polymethacrylates, polyacrylates, polyarylamides, condensation products of haloparaffin waxes and aromatic compounds, vinyl carboxylate polymers, and terpolymers of dialkylfumarates, vinyl esters of fatty acids and allyl vinyl ethers. U.S. Pat. Nos. 1,815,022; 2,015,748; 2,191,498; 2,387,501; 2,655, 479; 2,666,746; 2,721,877; 2,721,878; and 3,250,715 describe useful pour point depressants and/or the preparation thereof. Such additives may be used in an amount of about 0.01 to 5 weight percent, preferably about 0.01 to 1.5 weight percent.

Seal Compatibility Agents

Seal compatibility agents help to swell elastomeric seals by causing a chemical reaction in the fluid or physical change in the elastomer. Suitable seal compatibility agents for lubricating oils include organic phosphates, aromatic esters, aromatic hydrocarbons, esters (butylbenzyl phthalate, for example), and polybutenyl succinic anhydride. Such additives may be used in an amount of about 0.01 to 3 weight percent, preferably about 0.01 to 2 weight percent.

Antifoam Agents

Anti-foam agents may advantageously be added to lubricant compositions. These agents retard the formation of stable foams. Silicones and organic polymers are typical anti-foam agents. For example, polysiloxanes, such as silicon oil or polydimethyl siloxane, provide antifoam properties. Anti-foam agents are commercially available and may be used in conventional minor amounts along with other additives such as demulsifiers; usually the amount of these additives combined is less than 1 weight percent and often less than 0.1 weight percent.

Inhibitors and Antirust Additives

Antirust additives (or corrosion inhibitors) are additives that protect lubricated metal surfaces against chemical attack by water or other contaminants. A wide variety of these are commercially available.
One type of antirust additive is a polar compound that wets the metal surface preferentially, protecting it with a film of oil. Another type of antirust additive absorbs water by incorporating it in a water-in-oil emulsion so that only the oil touches the metal surface. Yet another type of antirust additive chemically adheres to the metal to produce a non-reactive surface. Examples of suitable additives include zinc dithiophosphates, metal phenolates, basic metal sulfonates, fatty acids and amines. Such additives may be used in an amount of about 0.01 to 5 weight percent, preferably about 0.01 to 1.5 weight percent.
The types and quantities of performance additives used in combination with the instant disclosure in lubricant compositions are not limited by the examples shown herein as illustrations.
When lubricating oil compositions contain one or more of the additives discussed above, the additive(s) are blended into the composition in an amount sufficient for it to perform its intended function. Typical amounts of such additives useful in the present disclosure are shown in Table 1 below.
It is noted that many of the additives are shipped from the additive manufacturer as a concentrate, containing one or more additives together, with a certain amount of base oil diluents. Accordingly, the weight amounts in the table below, as well as other amounts mentioned herein, are directed to the amount of active ingredient (that is the non-diluent portion of the ingredient). The weight percent (wt %) indicated below is based on the total weight of the lubricating oil composition.
When lubricating oil compositions contain one or more of the additives discussed above, the additive(s) are blended into the composition in an amount sufficient for it to perform its intended function. Typical amounts of such additives useful in the present disclosure are shown to in Table 1 below.
It is noted that many of the additives are shipped from the additive manufacturer as a concentrate, containing one or more additives together, with a certain amount of base oil diluents. Accordingly, the weight amounts in the table below, as well as other amounts mentioned herein, are directed to the amount of active ingredient (that is the non-diluent portion of the ingredient). The weight percent (wt %) indicated below is based on the total weight of the lubricating oil composition.

TABLE 1

Typical Amounts of Other Lubricating Oil Components

	Approximate	Approximate
Compound	wt % (Useful)	wt % (Preferred)

Antiwear	0.1-2	0.5-1
Dispersant	0.1-20	0.1-8
Detergent	0.1-20	0.1-8
Antioxidant	0.1-10	0.1-5
Friction Modifier	0.01-10	0.01-1.5
Pour Point Depressant	0.0-5	0.01-1.5
(PPD)
Anti-foam Agent	0.001-3	0.001-0.15
Viscosity Index Improver	0.0-8	0.1-6
(pure polymer basis)
Inhibitor and Antirust	0.01-5	0.01-1.5

The foregoing additives are all commercially available materials. These additives may be added independently but are usually precombined in packages which can be obtained from suppliers of lubricant oil additives. Additive packages with a variety of ingredients, proportions and characteristics are available and selection of the appropriate package will take the requisite use of the ultimate composition into account.
The following non-limiting examples are provided to illustrate the disclosure.

EXAMPLES

Test Methods

In all Examples herein, unless specified otherwise, the following properties are determined pursuant to the following ASTM standards:


				Noack	Pour
Properties	KV100	KV40	VI	Volatility	Point	CCSV

ASTM Standard	D445	D445	D2270	D5800	D5950	D5293

Additional bench testing was conducted for the lubricating oil compositions or formulations of this disclosure. The additional bench testing included the following: thermo-oxidation engine oil simulation testing (TEOST 33C-SAE 932837 and SAE 962039).
Deposit resistance formation of the lubricating oils was compared using a thermo-oxidation engine oil simulation test (TEOST 33C) measured by ASTM D6335. A good result in the TEOST test is defined as less than 80 mg, or less than 60 mg, or less than 40 mg, or less than 30 mg, or less than 20 mg, or less than 10 mg. TEOST 33C performance results correlates directly with high temperature deposit resistance and engine cleanliness for a lubricating oil. Hence, the lower the TEOST 33C total deposits in milligrams, the cleaner the internal engine components of an internal combustion engine lubricated with the lubricating oil compositions disclosed herein.

Inventive and Comparative Lubricating Oil Compositions

Table 2 below compares physical properties of the various Group I to Group V base stocks used in the comparative and inventive lubricating oils of the instant disclosure.

TABLE 2

Base Stock Properties

			Noack	CCS-35C,	Pour Point,	Aniline Point,
KV40	KV100	VI	Loss, %	cP	° C.	° C.

	D445	D445	D2270	D5800	D5293	D97	D611
Group 1 - 100N	20.4	4.1	99	26.3	5590	−18	98
Group II - 4.5 cSt	22.9	4.6	114	13.8	4906	−18	113
Group III - GTL4	18.3	4.1	126	11.9	1757	−37	121
Group IV - PAO 4	18.5	4.1	126	11.5	1442	<−60	120
Di-isononyl Phthalate	33.4	5.0	55	13.4		−39	<0
ester - Group V

FIG. 1 shows deposit results for partial lubricating oil compositions (no pour point depressant, no antifoam agent, no viscosity modifier or other lubricating oil additives) in order to assess the impact of base stock type, ashless organic friction modifier and overbased detergent on cleanliness performance. The partial lubricating oil compositions of FIG. 1 include both comparative examples and inventive examples in order to determine the impact of the ashless organic friction modifier (mixed mono (47%), di (33%) and tri (20%) fatty acids using saturated C₁₆and C₁₈alkyl chains) in each of the inventive examples on the high temperature cleanliness performance as measured by the TEOST 33C deposit test. Each of the inventive lubricating oil compositions of FIG. 1 also included a high TBN (350 TBN) calcium salicylate detergent at 2 wt. %. Five different base stocks were evaluated in the examples of FIG. 1 including a Group I-100 Neutral, a 4.5 cSt Group II, a 4 cSt Group III GTL, a 4 cSt Group IV PAO, and a Group V di-isononyl phthalate ester. For all five base stock types, it can be seen that when a combination of the ashless organic friction modifier (mixed mono (47%), di (33%) and tri (20%) fatty acids using saturated C₁₆and C₁₈alkyl chains) and 350 TBN calcium salicylate detergent were used in the partial formulations, the TEOST 33C deposit resistance is significantly lower than if either the ashless organic friction modifier or the overbased detergent or both were left out of the lubricating oil compositions. Hence, the surprising benefit in deposit resistance when the lubricating oils included a synergistic combination of the ashless organic friction modifier and the overbased detergent. It can be seen from FIG. 1 that lubricating oil compositions including a combination of the high TBN calcium salicylate detergent and the ashless organic friction modifier (mixed mono (47%), di (33%) and tri (20%) fatty acids using saturated C₁₆and C₁₈alkyl chains) provided for TEOST 33C deposits that were from 32 to 91% lower than comparable (comparative) lubricating oil compositions not including the ashless organic friction modifier. The improvement in deposit resistance for the inventive examples of FIG. 1 relative to the comparative examples not including the combination of the ashless organic friction modifier and the overbased detergent was surprising and unexpected. The improvement in deposit resistance and cleanliness performance was also seen across all five groups of base stocks tested.
FIG. 2 shows deposit results for partial lubricating oil compositions (no pour point depressant, no antifoam agent, no viscosity modifier or other lubricating oil additives) in order to assess the impact of overbased detergent type in combination with ashless organic friction modifier on cleanliness performance. The base stock used for all of the partial formulations was 4 cSt PAO. The five overbased detergents evaluated in FIG. 2 included 350 TBN calcium salicylate, 400 TBN magnesium sulfonate, 400 TBN calcium sulfonate, 255 TBN calcium phenate, and 68 TBN calcium salicylate. For all five overbased detergents, it can be seen that when a combination of the ashless organic friction modifier (mixed mono (47%), di (33%) and tri (20%) fatty acids using saturated C16 and C18 alkyl chains) and any of the five overbased detergents were used in the partial formulations, the TEOST 33C deposit resistance is significantly lower than if either the ashless organic friction modifier or the overbased detergent or both were left out of the lubricating oil compositions. Hence, further support for the surprising benefit in deposit resistance when the lubricating oils included a synergistic combination of the ashless organic friction modifier and the overbased detergent across a range of different overbased detergent types. The improvement in deposit resistance for the inventive examples of FIG. 2 ranged from 17 to 80% lower than comparable comparative examples not including the combination of the ashless organic friction modifier and the overbased detergent. Hence, the improvement in deposit resistance and cleanliness performance was seen across all five types of overbased detergents tested.
FIG. 3 shows deposit results for partial lubricating oil compositions (no pour point depressant, no antifoam agent, no viscosity modifier or other lubricating oil additives) in order to assess the impact of ashless organic friction modifier type in combination with a 350 TBN calcium salicylate detergent on cleanliness performance. The base stock used for all of the partial formulations was 4 cSt PAO. The nine different ashless organic friction modifiers evaluated in FIG. 3 included mixed mono-(47%), di-(33%) and tri-(20%) fatty acids using saturated C16 and C18 alkyl chains, glycerol mono-, di- and tri-mixed oleate, propylene glycol stearyl ether, poly-hydroxylcarboxylic acid esters of polyalkylene oxide modified polyols, n- tallow 1,3 diaminopropane, oleic acid, oleyl amide, and polymeric organic friction modifier containing PIBSA, glycerol and oligomerized ethylene oxide. The composition of the glycerol mono-, di- and tri-mixed oleate utilized was determined by GC-MS analysis with the analysis results indicated in the Table 3 below, which shows that it is mainly glycerol dioleate.

TABLE 3

Glycerol Mixed Oleate Compositional Analysis

		GLYCEROL MIXED OLEATE
		Wt. % (value in parentheses
	Area % based on GC-MS	based on GPC trace)

	Ocatdecadienoic acid	6.3
	Glycerol monooleate	13.3 (16.2)
	Glycerol dioleate	42.3 (42.6)
	Triglycerides	14.5
	Other	23.6 (41.2 - including triglycerides)

For all nine ashless organic friction modifiers evaluated, it can be seen that when a combination of any of one of the nine ashless organic friction modifiers was used in combination with a 350 TBN calcium salicylate detergent in the partial formulations, the TEOST 33C deposit resistance is significantly lower than if either the ashless organic friction modifier or the overbased detergent or both were left out of the lubricating oil compositions. Hence, further support for the surprising benefit in deposit resistance when the lubricating oils included a synergistic combination of the ashless organic friction modifier and the overbased detergent across a range of different ashless organic friction modifier types. The improvement in deposit resistance for the inventive examples of FIG. 3 ranged from 14 to 88% lower than comparable comparative examples not including the combination of the ashless organic friction modifier and the overbased detergent. Hence, the improvement in deposit resistance and cleanliness performance was seen across all nine types of ashless organic friction modifiers tested.
FIG. 4 (tabular form) and FIG. 5 (graphical form) show deposit results for partial lubricating oil compositions (no pour point depressant, no antifoam agent, no viscosity modifier or other lubricating oil additives) in order to assess the impact of ashless organic friction modifier loading level or concentration on cleanliness performance. The ashless organic friction modifier evaluated was a mixed mono-(47%), di-(33%) and tri-(20%) fatty acids using saturated C16 and C18 alkyl chains across a loading range in the partial formulation of 0 to 1 wt. %. The detergent used was 350 TBN calcium salicylate detergent at 2 wt. %. The base stock used for all of the partial formulations was 4 cSt PAO. It can be seen from FIGS. 4 and 5 that the TEOST 33C deposits decrease as the loading level of the mixed mono-(47%), di-(33%) and tri-(20%) fatty acids using saturated C16 and C18 alkyl chains ashless organic friction modifier increases in the inventive formulations. Relative to the comparative examples in FIG. 4, which do not include both the ashless organic friction modifier and the overbased detergent, the inventive examples provided a 21% to 91% decrease in TEOST 33C deposits, which is surprising and unexpected.
In summary, it has been discovered that by employing a combination of an ashless organic friction modifier and an overbased detergent in lubricating oil formulations, high deposit resistance is improved significantly in comparison to comparable lubricating oils not including a combination of the ashless organic friction modifier and the overbased detergent.

PCT and EP Clauses:

1. A lubricating oil composition comprising:
a lubricating oil base stock at from 20 to 95 wt % of the composition, at least one ashless organic friction modifier at from 0.1 to 20 wt % of the composition, at least one overbased detergent at from 0.1 to 20 wt % of the composition, and wherein the remainder of the lubricating oil composition includes one or more other lubricating oil additives;
wherein the at least one ashless organic friction modifier is selected from the group consisting of
wherein A and B are each independently H, a C1-C24 alkyl, or a C2-C24 alkenyl;
wherein A, B and C are each independently H, a C1-C24 alkyl, a C2-C24 alkenyl, a C1-C24 alkylcarbonyl, and a C1-C24 alkenylcarbonyl;
wherein A is a C1-C24 alkyl, or a C2-C24 alkenyl and B is O, an amino, a C1-C8 alkylamino or a C1-C8 dialkylamino;
n- tallow 1,3 diaminopropane; a polymeric organic friction modifier containing PIBSA, glycerol and oligomerized ethylene oxide and combinations thereof; and
wherein the deposit resistance as measured by TEOST 33C total deposits (ASTM D6335) is at least 20% lower than the deposit resistance for a comparable lubricating oil composition not including the combination of the at least one ashless organic friction modifier and the at least one overbased detergent.
2. The composition of clause 1, wherein the lubricating oil base stock is selected from the from the group consisting of a Group I base stock, a Group II base stock, a Group III base stock, a Group IV base stock, a Group V base stock and combinations thereof.
3. The composition of clauses 1-2, wherein the lubricating oil base stock is from 85 to 95 wt % of the lubricating oil composition.
4. The composition of clauses 1-3, wherein the lubricating oil base stock is selected from the group consisting of a 100N Group I base stock, a 4.5 cSt Group II base stock, a 4 cSt gas to liquids (GTL) base stock, a 4 cSt polyalphaolefin (PAO) base stock, a di-isononyl phthalate ester base stock and combinations thereof.
5. The composition of clauses 1-4, wherein the at least one overbased detergent is metal containing detergent including sulfonates, phenates, salicylates, carboxylates and combinations thereof and having a Total Base Number (TBN) ranging between 60 and 600.
6. The composition of clause 5, wherein the at least one overbased detergent is selected from the group consisting of 350 TBN calcium salicylate, 400 TBN magnesium sulfonate, 400 TBN calcium sulfonate, 255 TBN calcium phenate, 68 TBN calcium salicylate and combinations thereof.
7. The composition of clauses 1-6, wherein the at least one ashless organic friction modifier is selected from the group consisting of mixed mono-(47%), di-(33%) and tri-(20%) fatty acids using saturated C16 and C18 alkyl chains, glycerol mono-, di- and tri-mixed oleate, propylene glycol stearyl ether, poly-hydroxylcarboxylic acid esters of polyalkylene oxide modified polyols, oleic acid, oleyl amide, and combinations thereof.
8. The composition of clause 7, wherein the at least one ashless organic friction modifier is mixed mono-(47%), di-(33%) and tri-(20%) fatty acids using saturated C16 and C18 alkyl chains at from 0.1 to 2.0 wt % of the lubricating oil composition.
9. The composition of clauses 1-8, wherein the deposit resistance as measured by TEOST 33C total deposits (ASTM D6335) is less than or equal to 75 mg.
10. The composition of clauses 1-9, wherein the one or more other lubricating oil additives are selected from the group consisting of an anti-wear additive, viscosity index improver, antioxidant, dispersant, pour point depressant, corrosion inhibitor, metal deactivator, seal compatibility additive, anti-foam agent, inhibitor, anti-rust additive, and ash forming metal containing friction modifier.
11. The composition of clause 10, wherein the one or more other lubricating oil additives range from 1 to 10 wt % of the lubricating oil composition and include a combination of a PIBSA/PAM dispersant, a C3/C6 secondary ZDDP antiwear additive, and a diphenylamine antioxidant.
12. The composition of clauses 1-11, wherein the lubricating oil base stock has a kinematic viscosity at 100 deg. C. ranging from 2.5 to 12 cSt.
13. The composition of clauses 1-12, wherein lubricating oil composition is an SAE viscosity grade selected from the group consisting of 0W-30, 5W-30, 0W-20, 5W-20, 0W-16, 5W-16, 0W-12, 5W-12, 0W-8, and 5W-8.
14. The composition of clauses 1-13, wherein the lubricating oil composition is a passenger vehicle engine oil (PVEO) or a commercial vehicle engine oil (CVEO).
15. A method for improving the high temperature deposit resistance of a lubricating oil composition for use in lubricating a mechanical component comprising:
providing a lubricating oil composition to a mechanical component, wherein the lubricating oil composition comprises: a lubricating oil base stock at from 20 to 95 wt % of the composition, at least one ashless organic friction modifier at from 0.1 to 20 wt % of the composition, at least one overbased detergent at from 0.1 to 20 wt % of the composition, and wherein the remainder of the lubricating oil composition includes one or more other lubricating oil additives;
wherein the at least one ashless organic friction modifier is selected from the group consisting of
wherein A and B are each independently H, a C1-C24 alkyl, or a C2-C24 alkenyl;
wherein A, B and C are each independently H, a C1-C24 alkyl, a C2-C24 alkenyl, a C1-C24 alkylcarbonyl, and a C1-C24 alkenylcarbonyl;
wherein A is a C1-C24 alkyl, or a C2-C24 alkenyl and B is O, an amino, a C1-C8 alkylamino or a C1-C8 dialkylamino;
n- tallow 1,3 diaminopropane;
a polymeric organic friction modifier containing PIBSA, glycerol and oligomerized ethylene oxide and combinations thereof; and

- wherein the deposit resistance as measured by TEOST 33C total deposits (ASTM D6335) is at least 20% lower than the deposit resistance for a comparable lubricating oil composition not including the combination of the at least one ashless organic friction modifier and the at least one overbased detergent.

All patents and patent applications, test procedures (such as ASTM methods, UL methods, and the like), and other documents cited herein are fully incorporated by reference to the extent such disclosure is not inconsistent with this disclosure and for all jurisdictions in which such incorporation is permitted.
When numerical lower limits and numerical upper limits are listed herein, ranges from any lower limit to any upper limit are contemplated. While the illustrative embodiments of the disclosure have been described with particularity, it will be understood that various other modifications will be apparent to and can be readily made by those skilled in the art without departing from the spirit and scope of the disclosure. Accordingly, it is not intended that the scope of the claims appended hereto be limited to the examples and descriptions set forth herein but rather that the claims be construed as encompassing all the features of patentable novelty which reside in the present disclosure, including all features which would be treated as equivalents thereof by those skilled in the art to which the disclosure pertains.
The present disclosure has been described above with reference to numerous embodiments and specific examples. Many variations will suggest themselves to those skilled in this art in light of the above detailed description. All such obvious variations are within the full intended scope of the appended claims.

Claims

1. A lubricating oil composition comprising:

a lubricating oil base stock at from 20 to 95 wt % of the composition, at least one ashless organic friction modifier at from 0.1 to 20 wt % of the composition, at least one overbased detergent at from 0.1 to 20 wt % of the composition, and wherein the remainder of the lubricating oil composition includes one or more other lubricating oil additives;

wherein the at least one ashless organic friction modifier is selected from the group consisting of

wherein A and B are each independently H, a C1-C24 alkyl, or a C2-C24 alkenyl;

wherein A, B and C are each independently H, a C1-C24 alkyl, a C2-C24 alkenyl, a C1-C24 alkylcarbonyl, and a C1-C24 alkenylcarbonyl;

wherein A is a C1-C24 alkyl, or a C2-C24 alkenyl and B is O, an amino, a C1-C8 alkylamino or a C1-C8 dialkylamino;

n-tallow 1,3 diaminopropane; a polymeric organic friction modifier containing PIBSA, glycerol and oligomerized ethylene oxide and combinations thereof; and

wherein the deposit resistance as measured by TEOST 33C total deposits (ASTM D6335) is at least 20% lower than the deposit resistance for a comparable lubricating oil composition not including the combination of the at least one ashless organic friction modifier and the at least one overbased detergent.

2. The composition of claim 1, wherein the lubricating oil base stock is selected from the from the group consisting of a Group I base stock, a Group II base stock, a Group III base stock, a Group IV base stock, a Group V base stock and combinations thereof.

3. The composition of claim 1, wherein the lubricating oil base stock is from 85 to 95 wt % of the lubricating oil composition.

4. The composition of claim 3, wherein the lubricating oil base stock is selected from the group consisting of a 100N Group I base stock, a 4.5 cSt Group II base stock, a 4 cSt gas to liquids (GTL) base stock, a 4 cSt polyalphaolefin (PAO) base stock, a di-isononyl phthalate ester base stock and combinations thereof.

5. The composition of claim 1, wherein the at least one overbased detergent is metal containing detergent including sulfonates, phenates, salicylates, carboxylates and combinations thereof and having a Total Base Number (TBN) ranging between 60 and 600.

6. The composition of claim 5, wherein the at least one overbased detergent is selected from the group consisting of 350 TBN calcium salicylate, 400 TBN magnesium sulfonate, 400 TBN calcium sulfonate, 255 TBN calcium phenate, 68 TBN calcium salicylate and combinations thereof.

7. The composition of claim 1, wherein the at least one ashless organic friction modifier is selected from the group consisting of mixed mono-(47%), di-(33%) and tri-(20%) fatty acids using saturated C16 and C18 alkyl chains, glycerol mono-, di- and tri-mixed oleate, propylene glycol stearyl ether, poly-hydroxylcarboxylic acid esters of polyalkylene oxide modified polyols, oleic acid, oleyl amide, and combinations thereof.

8. The composition of claim 7, wherein the at least one ashless organic friction modifier is mixed mono-(47%), di-(33%) and tri-(20%) fatty acids using saturated C16 and C18 alkyl chains at from 0.1 to 2.0 wt % of the lubricating oil composition.

9. The composition of claim 1, wherein the deposit resistance as measured by TEOST 33C total deposits (ASTM D6335) is less than or equal to 75 mg.

10. The composition of claim 1, wherein the one or more other lubricating oil additives are selected from the group consisting of an anti-wear additive, viscosity index improver, antioxidant, dispersant, pour point depressant, corrosion inhibitor, metal deactivator, seal compatibility additive, anti-foam agent, inhibitor, anti-rust additive, and ash forming metal containing friction modifier.

11. The composition of claim 1, wherein the one or more other lubricating oil additives range from 1 to 10 wt % of the lubricating oil composition and include a combination of a PIBSA/PAM dispersant, a C3/C6 secondary ZDDP antiwear additive, and a diphenylamine antioxidant.

12. The composition of claim 1, wherein the lubricating oil base stock has a kinematic viscosity at 100 deg. C. ranging from 2.5 to 12 cSt.

13. The composition of claim 1, wherein lubricating oil composition is an SAE viscosity grade selected from the group consisting of 0W-30, 5W-30, 0W-20, 5W-20, 0W-16, 5W-16, 0W-12, 5W-12, 0W-8, and 5W-8.

14. The composition of claim 1, wherein the lubricating oil composition is a passenger vehicle engine oil (PVEO) or a commercial vehicle engine oil (CVEO).

15. A method for improving the high temperature deposit resistance of a lubricating oil composition for use in lubricating a mechanical component comprising:

providing a lubricating oil composition to a mechanical component, wherein the lubricating oil composition comprises: a lubricating oil base stock at from 20 to 95 wt % of the composition, at least one ashless organic friction modifier at from 0.1 to 20 wt % of the composition, at least one overbased detergent at from 0.1 to 20 wt % of the composition, and wherein the remainder of the lubricating oil composition includes one or more other lubricating oil additives;

wherein A and B are each independently H, a C1-C24 alkyl, or a C2-C24 alkenyl;

16. The method of claim 15, wherein the lubricating oil base stock is selected from the from the group consisting of a Group I base stock, a Group II base stock, a Group III base stock, a Group IV base stock, a Group V base stock and combinations thereof.

17. The method of claim 15, wherein the lubricating oil base stock is from 85 to 95 wt % of the lubricating oil composition.

18. The method of claim 15, wherein the lubricating oil base stock is selected from the group consisting of a 100N Group I base stock, a 4.5 cSt Group II base stock, a 4 cSt gas to liquids (GTL) base stock, a 4 cSt polyalphaolefin (PAO) base stock, a di-isononyl phthalate ester base stock and combinations thereof.

19. The method of claim 15, wherein the at least one overbased detergent is metal containing detergent including sulfonates, phenates, salicylates, carboxylates and combinations thereof and having a Total Base Number (TBN) ranging between 60 and 600.

20. The method of claim 19, wherein the at least one overbased detergent is selected from the group consisting of 350 TBN calcium salicylate, 400 TBN magnesium sulfonate, 400 TBN calcium sulfonate, 255 TBN calcium phenate, 68 TBN calcium salicylate and combinations thereof.

21. The method of claim 15, wherein the at least one ashless organic friction modifier is selected from the group consisting of mixed mono-(47%), di-(33%) and tri-(20%) fatty acids using saturated C16 and C18 alkyl chains, glycerol mono-, di- and tri-mixed oleate, propylene glycol stearyl ether, poly-hydroxylcarboxylic acid esters of polyalkylene oxide modified polyols, oleic acid, oleyl amide, and combinations thereof.

22. The method of claim 21, wherein the at least one ashless organic friction modifier is mixed mono-(47%), di-(33%) and tri-(20%) fatty acids using saturated C16 and C18 alkyl chains at from 0.1 to 2.0 wt % of the lubricating oil composition.

23. The method of claim 15, wherein the deposit resistance as measured by TEOST 33C total deposits (ASTM D6335) is less than or equal to 75 mg.

24. The method of claim 15, wherein the one or more other lubricating oil additives are selected from the group consisting of an anti-wear additive, viscosity index improver, antioxidant, dispersant, pour point depressant, corrosion inhibitor, metal deactivator, seal compatibility additive, anti-foam agent, inhibitor, anti-rust additive, and ash forming metal containing friction modifier.

25. The method of claim 24, wherein the one or more other lubricating oil additives range from 1 to 10 wt % of the lubricating oil composition and include a combination of a PIBSA/PAM dispersant, a C3/C6 secondary ZDDP antiwear additive, and a diphenylamine antioxidant.

26. The method of claim 15, wherein the lubricating oil base stock has a kinematic viscosity at 100 deg. C. ranging from 2.5 to 12 cSt.

27. The method of claim 15, wherein the mechanical component is selected from the group consisting of internal combustion engines, power trains, drivelines, transmissions, gears, gear trains, gear sets, compressors, pumps, hydraulic systems, bearings, bushings, turbines, pistons, piston rings, cylinder liners, cylinders, cams, tappets, lifters, bearings (journal, roller, tapered, needle, ball), gears and valves.

28. The method of claim 27, wherein the mechanical component is an internal combustion engine.

29. The method of claim 28, wherein lubricating oil composition is an SAE viscosity grade selected from the group consisting of 0W-30, 5W-30, 0W-20, 5W-20, 0W-16, 5W-16, 0W-12, 5W-12, 0W-8, and 5W-8.

30. The method of claim 29, wherein the lubricating oil composition is a passenger vehicle engine oil (PVEO) or a commercial vehicle engine oil (CVEO).