CN115734999A

CN115734999A - Engine oil lubricant composition with steel corrosion protection and preparation method thereof

Info

Publication number: CN115734999A
Application number: CN202180045146.6A
Authority: CN
Inventors: N·W·麦克博德; D·E·德克曼; M·L·布希; D·G·L·霍尔特; M·L·布鲁曼菲尔德
Original assignee: ExxonMobil Technology and Engineering Co
Current assignee: ExxonMobil Technology and Engineering Co
Priority date: 2020-11-06
Filing date: 2021-11-04
Publication date: 2023-03-03
Also published as: US20220145206A1; WO2022099291A1

Abstract

Low sulfated ash engine oil lubricant compositions containing organic friction modifiers are provided having improved fuel economy and corrosion resistance. The lubricant composition includes one or more metal-free corrosion inhibitors having organic acid groups and/or one or more organometallic naphthalene molecules having an ASTM D2896 total base number of less than 3mg KOH/g. The resulting lubricant composition improves ASTM D6557 corrosion protection for low sulfated ash engine oils containing organic friction modifiers while maintaining excellent fuel economy performance.

Description

Engine oil lubricant composition with steel corrosion protection and preparation method thereof

Technical Field

Embodiments of the present invention generally relate to low sulfated ash engine oil lubricant compositions and methods of making the same. Such compositions are useful in gasoline and diesel engines and provide an excellent combination of aftertreatment device protection, steel corrosion protection, and fuel efficiency.

Background

A major challenge in engine oil formulation is to simultaneously achieve aftertreatment device protection while also maintaining fuel economy performance and providing steel corrosion protection.

The fuel efficiency requirements of passenger vehicles are becoming more and more stringent. Burning 1 gallon of gasoline produces about 19.5 pounds of carbon dioxide (CO) ₂ ). Therefore, a technique to improve fuel economy (i.e., burn more miles per gallon) would necessarily reduce CO ₂ And (5) discharging. Over the past few years, new legislation in the united states and the european union has set fuel economy and carbon emissions goals that are not easily achieved with today's vehicle and lubricant technologies. For example, in Europe, the CO of a gasoline passenger car ₂ Emission requirements of 130g CO already from 2015 ₂ The/km dropped to 95 in 2021, 81 in 2025 and 59 in 2030. Due to these stricter government regulations on vehicle fuel consumption and carbon emissions, the use of passenger car diesel engines or gasoline direct injection engines or gasoline hybrid engines is becoming increasingly common.

To meet future carbon dioxide emission requirements, engine oil formulations often contain organic friction modifiers to help reduce friction, which helps to improve engine efficiency and fuel economy. However, a major challenge for engine oil formulations containing organic friction modifiers is high surface activity which can lead to greater corrosion, which leads to engine inefficiency and therefore reduced fuel economy.

Another major challenge in engine oil formulations is aftertreatment device durability. For example, diesel Particulate Filters (DPFs) and Gasoline Particulate Filters (GPFs) are exhaust aftertreatment devices used to control particulate matter and particle count emissions, and are negatively affected by metal species contained in engine oil formulations. Sulfated ash (ASTM D874) is a common measure of the metal content of engine oil formulations. In the ASTM D874 test, engine oil is evaporated to a residue and then reacted with sulfuric acid at 775 ℃. This converts the metallic calcium (Ca), magnesium (Mg), zinc (Zn), molybdenum (Mo), sodium (Na) in the residue into a sulfated "ash" which is then weighed.

To provide aftertreatment device durability, engine oils are typically formulated to have ≦ 1.0 wt% ash, or 0.9 wt% ash, or 0.8 wt% ash, or 0.5 wt% sulfated ash. The main source of sulfated ash is from metal detergents, which are used to provide piston cleanliness and neutralize acids formed by combustion. As the ash level decreases, the metal detergent level also decreases, which limits the ability of the engine oil to neutralize acidic species.

Accordingly, there remains a need for improved engine oil formulations that enable aftertreatment device protection while also providing fuel economy performance and steel corrosion protection.

Disclosure of Invention

Summary of The Invention

A low sulfated ash engine oil lubricant composition is provided. The engine oil lubricant composition may have a sulfated ash content of 0.5 wt.% or less and an HTHS (ASTM D4683) of less than or equal to 3.7cP at 150 ℃. In at least one particular embodiment, the composition may include from about 40 wt.% to about 90 wt.% of at least one base oil, from about 0.1 wt.% to about 5 wt.% of an organic friction modifier, from about 1 wt.% to about 6 wt.% of at least one detergent comprising magnesium or calcium, and from about 0.01 wt.% to about 1 wt.% of a corrosion inhibitor having at least one organic acid or organic salt group. In at least one other particular embodiment, the composition may include from about 40 wt% to about 90 wt% of at least one base oil, from about 0.1 wt% to about 5 wt% of an organic friction modifier, from about 1 wt% to about 6 wt% of at least one detergent comprising magnesium or calcium, and from about 0.01 wt% to about 1 wt% of a corrosion inhibitor comprising an organometallic naphthalene compound.

Detailed Description

It has been surprisingly found that a metal-free corrosion inhibitor having organic acid or organic salt groups can improve ASTM D6557 corrosion protection for low sulfated ash engine oils containing organic friction modifiers while maintaining excellent fuel economy performance. It has also been surprisingly found that organometallic naphthalene molecules having an ASTM D2896 total base number of less than 3mg KOH/g can improve ASTM D6557 corrosion protection of low sulfated ash engine oils containing organic friction modifiers while maintaining excellent fuel economy performance.

The ASTM D6557 test is a steel corrosion test in which a 5.6mm diameter steel ball is placed in a test tube with 10mL of engine oil. The test tube with the engine oil and steel ball was then placed on a mechanical shaker. An acid mixture of hydrochloric acid (HCl), hydrobromic acid (HBr) and acetic acid was continuously added to the tube. The test was carried out at 48 ℃ for 18 hours. Thereafter, the steel ball was removed, rinsed, and the reflectivity of the ball was measured. The new ball has a reflectivity of approximately 133 average gray value units ("AGV"). A decrease in the mean gray value indicates that corrosion has occurred.

In the following discussion and claims, the terms "include" and "comprise" are used in an open-ended fashion, and thus should be interpreted to mean "include, but not limited to. The phrase "consisting essentially of means that the described/claimed composition does not contain any other components that would substantially change its properties more than 5% of the properties, and in any case, does not contain any other components to a level of greater than 3 mass%. The term "or" is intended to encompass both exclusive and inclusive, i.e., "a or B" is intended to be synonymous with "at least one of a and B," unless the context clearly dictates otherwise. The term "weight%" means percent by weight, "volume%" means percent by volume, "mole%" means percent by mole, "ppm" means parts per million, and "ppm wt" and "wppm" are used interchangeably and mean parts per million on a weight basis. All concentrations herein are expressed on the basis of the total amount of the composition in question, unless otherwise indicated.

Base oil

Lubricating base oils useful in the present disclosure are natural and synthetic oils, and the unconventional oil (or mixtures thereof) may be used unrefined, refined, or rerefined (the latter also known as reclaimed or reprocessed oil). Unrefined oils are those obtained directly from a natural or synthetic source without added purification treatment. These include shale oil obtained directly from retorting operations, petroleum oil obtained directly from primary distillation or ester oil obtained directly from an esterification process. Refined oils are similar to the oils discussed for unrefined oils except that the refined oils are subjected to one or more purification steps to improve at least one lubricating oil property. Those skilled in the art are familiar with many purification methods. These methods include solvent extraction, secondary distillation, acid extraction, basic extraction, filtration and percolation. Rerefined oils are obtained by processes similar to those used to refine oils but using oils that have been previously used.

Groups I, II, III, IV and V are broad categories of base stocks developed and defined by the american petroleum institute (API Publication 1509 at www.api. Org) to create guidelines for lubricant base oils. Group I base stocks generally have a viscosity index of about 80 to 120 and contain greater than about 0.03% sulfur and/or less than about 90% saturates. Group II base stocks generally have a viscosity index of 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 basestocks generally 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 stocks include base stocks not included in groups I-IV.

Non-limiting exemplary group V binders include alkylated naphthalene binders, ester binders, aliphatic ether binders, aryl ether binders, ionic liquid binders, and combinations thereof.

Table 1: base oil properties of each of these five groups.

Base oil Properties

Natural oils include animal oils, vegetable oils (e.g., castor oil and lard oil), and mineral oils. Animal and vegetable oils with advantageous thermo-oxidative stability can be used. Among natural oils, mineral oils are preferred. Mineral oils vary widely according to their natural source, for example, according to whether they are paraffinic, naphthenic, or mixed paraffinic-naphthenic. Oils derived from coal or shale are also useful. Natural oils also vary according to the process used for their production and purification, such as their distillation range and whether they are straight-run or cracked, hydrorefined or solvent extracted.

Group II and/or group III hydrotreated or hydrocracked basestocks, including synthetic oils such as polyalphaolefins, alkylaromatics and synthetic esters, are also well known basestocks.

Synthetic oils include hydrocarbon oils. Hydrocarbon oils include oils such as polymerized and interpolymerized olefins (e.g., polybutylenes, polypropylenes, propylene isobutylene copolymers, ethylene-olefin copolymers, and ethylene-alpha-olefin copolymers). Polyalphaolefin (PAO) oil base stocks are common synthetic hydrocarbon oils. For example, derivatives derived from C may be used ₈ 、C ₁₀ 、C ₁₂ 、C ₁₄ PAOs of olefins or mixtures thereof. See U.S. Pat. nos. 4,956,122;4,827,064 and 4,827,073.

The number average molecular weight of PAOs (which are known materials and are generally available on a large commercial scale from suppliers such as ExxonMobil Chemical Company, chevron Phillips Chemical Company, BP and others) typically varies from about 250g/mol to about 3,000g/mol, although PAOs can be made up to viscosities of about 100cSt (100 ℃). PAOs are typically comprised of lower molecular weight hydrogenated polymers or oligomers of alpha-olefins including, but not limited to, C ₂ To about C ₃₂ Alpha-olefins, of which C is preferred ₈ To about C ₁₆ Alpha-olefins such as 1-octene, 1-decene, 1-dodecene, and the like. Preferred polyalphaolefins are poly-1-octene, poly-1-decene, and poly-1-dodecene, and mixtures and mixed olefin derived polyolefins thereof. However, at C ₁₄ To C ₁₈ Dimers of higher olefins in the range may be used to provide a low viscosity base with acceptably low volatility. Depending on the viscosity grade and starting oligomers, the PAO may be predominantly trimers and tetramers of the starting olefins, with small amounts of higher oligomers, with a viscosity range of 1.5 to 12cSt (100 ℃).

The PAO fluid may suitably be prepared by polymerising alpha-olefins in the presence of a polymerisation catalyst, for example a Friedel-Crafts catalyst comprising, for example, aluminium trichloride, boron trifluoride, or a complex of boron trifluoride with water, an alcohol such as ethanol, propanol or butanol, a carboxylic acid or ester such as ethyl acetate or ethyl propionate. For example, the methods disclosed in U.S. Pat. No. 4,149,178 or U.S. Pat. No. 3,382,291 may be suitably employed in the present invention. Additional 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.C ₁₄ -C ₁₈ Dimers of olefins are described in U.S. Pat. No. 4,218,330.

The hydrocarbyl aromatic compound may be used as a base oil or base oil component and may be any hydrocarbyl molecule containing at least about 5% by weight thereof derived from an aromatic moiety, such as a benzene-type moiety or a cycloalkane-type moiety, or derivatives thereof. These hydrocarbyl aromatic compounds include alkylbenzenes, alkylnaphthalenes, alkyldiphenyl ethers, alkylnaphthols, alkyldiphenyl sulfides, alkylated bisphenol a, alkylated thiodiphenols, and the like. The aromatic compound may be monoalkylated, dialkylated, polyalkylated, etc. The aromatic compound may be mono-or polyfunctional. The hydrocarbyl groups can also be comprised of mixtures of alkyl groups, alkenyl groups, alkynyl groups, cycloalkyl groups, cycloalkenyl groups, and other related hydrocarbyl groups. The hydrocarbyl group may be in about C ₆ To about C ₆₀ Wherein about C is generally preferred ₈ To about C ₂₀ In the presence of a surfactant. Mixtures of hydrocarbyl groups are generally preferred, and up to about three such substituents may be present. The hydrocarbyl group may optionally contain sulfur, oxygen and/or nitrogen containing substituents. The aromatic groups may also be derived from natural (petroleum) sources, provided that at least about 5% of the molecules are made up of aromatic moieties of the type described above. For the hydrocarbyl aromatic component, a viscosity of from about 1.8cSt to about 50cSt at 100 ℃ is preferred, and a viscosity of from about 2.2cSt to about 20cSt is generally more preferred. In one embodiment, use is made of a compound in which the alkyl radical consists essentially of1-hexadecene, or a mixture thereof. Other alkylates of aromatic compounds may be advantageously used. For example, naphthalene or methylnaphthalene may be alkylated with olefins such as octene, decene, dodecene, tetradecene, or higher, mixtures of similar olefins, and the like. Depending on the application, useful concentrations of hydrocarbyl aromatic compounds in the lubricating oil composition may range from about 2% to about 25%, preferably from about 4% to about 20%, more preferably from about 4% to about 15%.

The esters comprise a useful binder. Additive solvency and seal compatibility characteristics can be imparted by utilizing esters such as esters of dibasic acids with monoalkanols and polyol esters of monocarboxylic acids. The former type of esters include, for example, esters of dicarboxylic acids such as phthalic acid, succinic acid, alkyl succinic acids, alkenyl succinic acids, maleic acid, azelaic acid, suberic acid, sebacic acid, fumaric acid, adipic acid, linoleic acid dimer, malonic acid, alkylmalonic acids, alkenyl malonic acids, etc., with various alcohols such as butanol, hexanol, dodecanol, 2-ethylhexanol, 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, eicosyl sebacate, and the like.

Particularly useful synthetic esters are those obtained as follows: one or more polyols, preferably sterically hindered polyols (such as neopentyl polyols, for example neopentyl glycol, trimethylolethane, 2-methyl-2-propyl-1, 3-propanediol, trimethylolpropane, pentaerythritol and dipentaerythritol) are reacted with an alkanoic acid containing at least about 4 carbon atoms, preferably C ₅ -C ₃₀ Acids, such as saturated straight chain fatty acids, including caprylic, capric, lauric, myristic, palmitic, stearic, arachidic and behenic acids, or corresponding branched fatty acids or unsaturated fatty acids, such as oleic acid, or mixtures of any of these.

Suitable synthetic ester components include esters of trimethylolpropane, trimethylolbutane, trimethylolethane, pentaerythritol and/or dipentaerythritol with one or more monocarboxylic acids having from about 5 to about 10 carbon atoms. These esters are widely commercially available, for example, the Mobil P-41 and P-51 esters from ExxonMobil Chemical Company.

Other useful fluids of lubricating viscosity include unconventional or unconventional base stocks which have been processed, preferably catalyzed, or synthesized to provide high performance lubricating properties.

Unconventional or unconventional base/oils include one or more of the following: mixtures of base stock(s) derived from one or more Gas-to-Liquids (GTL) materials, as well as isomerate/isodewaxed base stock(s) derived from natural wax or waxy feedstocks, mineral and/or non-mineral oil waxy feedstocks such as slack waxes, natural waxes, and waxy feedstocks such as Gas oils, waxy fuel hydrocracking bottoms, waxy raffinates, hydrocrackates, thermal cracked oils, or other mineral, mineral oils, or even non-petroleum derived waxy materials such as waxy materials derived from coal liquefaction or shale oils, and mixtures of such base stocks.

The base oil constitutes the major component of the engine oil lubricant composition and is typically present in an amount of from about 50 to about 99 weight percent, for example from 70 to 90 weight percent or from about 85 to about 95 weight percent, based on the total weight of the composition. The base oil may be selected from any synthetic or natural oil commonly used as crankcase lubricating oils for spark-ignition and compression-ignition engines. The base oil has a kinematic viscosity according to ASTM standards of from about 1.0cSt to about 16.0cSt (100 ℃), preferably from about 1.0cSt to about 12.0cSt (100 ℃), more preferably from about 2.0cSt to about 8.0cSt (100 ℃), even more preferably from about 2.0cSt to about 4.0cSt (100 ℃). Mixtures of synthetic and natural base oils may be used if desired. As used herein, the binder name is related to the kinematic viscosity of the binder at ASTM D445 ℃ of 100 ℃. For example, PAO 4 has an ASTM D445 kinematic viscosity of 4 cSt; GTL 3 had a D445 kinematic viscosity of 3cSt at 100 ℃.

The engine oil lubricant composition of the present invention may have an ASTM D4683 High Temperature High Shear (HTHS) viscosity of less than or equal to 3.7cP at 150 ℃, or less than or equal to 2.9cP at 150 ℃, or less than or equal to 2.6cP at 150 ℃, or less than or equal to 2.3cP at 150 ℃, preferably about 2.6cP at 150 ℃. HTHS viscosity is a measure of lubricant viscosity under severe engine conditions, measured using ASTM D4683.

Viscosity Modifiers (VM)

Viscosity modifiers are also known as VI improvers, viscosity index improvers, and viscosity modifiers. Suitable viscosity modifiers provide high and low temperature operability for the lubricant. Suitable viscosity modifiers also impart shear stability at elevated temperatures and acceptable viscosity at low temperatures. Suitable viscosity modifiers may be or may include one or more linear or star polymers and/or copolymers of methacrylate, butadiene, olefins, isoprene or alkylated styrenes, polyisobutylene, polymethacrylates, ethylene-propylene, hydrogenated block copolymers of styrene and isoprene, polyacrylates, styrene-isoprene block copolymers, styrene-butadiene copolymers, ethylene-propylene copolymers, hydrogenated star polyisoprenes, and combinations thereof.

The term "polymer" as used herein refers to any two or more of the same or different repeat units/monomer units. The term "homopolymer" refers to a polymer having the same units. The term "copolymer" refers to a polymer having two or more units different from each other, and includes terpolymers and the like. The term "terpolymer" refers to a polymer having three different monomeric units from each other. The term "different" refers to units that indicate that the units differ from each other by at least one atom or are isomerically different. Also, as used herein, the definition of polymer includes homopolymers, copolymers, and the like. Furthermore, the term "styrenic block copolymer" refers to any copolymer comprising units of styrene and a mid-block.

Suitable olefin copolymers are available, for example, under the trade name

(e.g. in

And

) Commercially available from Chevron Oronite Company LLC; and by trade name

(e.g. in

) From Afton Chemical Corporation and under the trade name

Commercially available from The Lubrizol Corporation. Suitable polyisoprene polymers are commercially available, for example, from infinium International Limited under the trade designation "SV 200". Suitable diene-styrene copolymers are commercially available, for example, from Infineum International Limited under the trade designation "SV 260".

One particularly suitable viscosity modifier is polyisobutylene. Another particularly suitable viscosity modifier is polymethacrylate, which also acts as a pour point depressant. Other particularly suitable viscosity modifiers include copolymers of ethylene and propylene, hydrogenated block copolymers of styrene and isoprene, and polyacrylates. Specific examples include styrene-isoprene and styrene-butadiene based polymers having a molecular weight of 50,000g/mol to 200,000g/mol.

Suitable viscosity modifiers may further include high molecular weight hydrocarbons, polyesters, and dispersants that function as both viscosity modifiers and dispersants. Typical molecular weights of these polymers may be from about 10,000g/mol to about 2,000,000g/mol, more typically from about 20,000g/mol to about 1,500,000g/mol, and even more typically from about 50,000g/mol to about 1,200,000g/mol.

The at least one viscosity modifier may be included in the engine oil lubricant composition at a concentration of 0.1 to 5 wt.%, or 0.1 to 8 wt.%, or 0.1 to 14 wt.%, or 0.5 to 10 wt.%, or 0.01 to 2 wt.%, or 1.0 to 7.5 wt.%, or 1.5 to 5 wt.%. The at least one viscosity modifier may also be included in the engine oil lubricant composition at a concentration ranging from a lower limit of about 0.1 wt.%, about 0.3 wt.%, or about 0.5 wt.% to an upper limit of about 5 wt.%, about 8 wt.%, or about 16 wt.%. The concentration of the at least one viscosity modifier may also range from a lower limit of about 0.1 wt.%, about 0.5 wt.%, or about 1.0 wt.% to an upper limit of about 8 wt.%, about 12 wt.%, or about 14 wt.%. The foregoing viscosity modifier concentrations are based on the polymer concentrate, based on the total weight of the lubricating composition.

Friction Modifier (FM)

A friction modifier is any material or two or more materials that can alter the coefficient of friction of a surface lubricated by a lubricant or fluid containing such material(s). If desired, friction modifiers (also known as friction reducers) or lubricant or oil additives, as well as other such agents that modify the ability of the base oil, formulated lubricant composition or functional fluid to modify the coefficient of friction of a lubricated surface, can be effectively used in combination with the base oil or lubricant composition of the present invention. Friction modifiers that reduce the coefficient of friction are particularly advantageous in combination with the base oil and lubricating oil compositions of the present invention. The friction modifier may include a metal-containing compound or material and an ashless compound or material, or mixtures thereof. The metal-containing friction modifier may include a metal salt or a metal-ligand complex, where the metal may include an alkali metal, an alkaline earth metal, or a transition group metal. Such metal-containing friction modifiers may also have low ash characteristics. The transition metal may include molybdenum (Mo), antimony (Sb), tin (Sn), iron (Fe), copper (Cu), zinc (Zn), and the like. Such suitable ligands may include hydrocarbyl derivatives 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 oxygen (O), nitrogen (N), sulfur (S), or phosphorus (P), alone or in combination.

Ashless friction modifiers may also be used. Suitable ashless friction modifiers may include hydroxyl-containing hydrocarbon base oils, glycerol esters, partial glycerol esters, glycerol ester derivatives, fatty organic acids, fatty amines and sulfurized fatty acids. Fatty acids include short chain fatty acids, medium chain fatty acids, long chain fatty acids, and very long chain fatty acids. Short chain fatty acids have a carbon chain of 1 to 5 carbon atoms. Medium chain fatty acids have a carbon chain of 6 to 12 carbon atoms. Long chain fatty acids have a carbon chain of 13 to 21 carbon atoms. Very long chain fatty acids have a carbon chain greater than 21 carbons. These carbon chains may be saturated or unsaturated. Suitable ashless friction modifiers may also include lubricant materials containing an effective amount of polar groups, such as hydroxyl-containing hydrocarbon base oils, glycerol esters, partial glycerol esters, glycerol ester derivatives, and the like. Suitable ashless friction modifiers may include alkyl or alkylene fatty acid esters, alkyl or alkylene glycerides of glycerol esters. The polar groups in the friction modifier may include hydrocarbyl groups containing an effective amount of oxygen (O), nitrogen (N), sulfur (S), or phosphorus (P), alone or in combination. Other friction modifiers that may be particularly effective include, for example, salts (ash-and ashless derivatives) of fatty acids, fatty alcohols, fatty amides, fatty esters, hydroxyl-containing carboxylates, and similar synthetic long-chain hydrocarbon acids, alcohols, amides, esters, hydroxyl carboxylates, and the like. In some cases, fatty organic acids, fatty amines, and sulfurized fatty acids may be used as suitable friction modifiers. In some cases, friction modifiers containing ethylene oxide, oligomers of ethylene oxide, or polymer segments of ethylene oxide are effective.

The ashless friction modifier may be or may include polymeric and/or non-polymeric molecules. Suitable polymeric friction modifiers may have a molecular weight of 3,000g/mol or greater; 4,000g/mol or more; 5,000g/mol or more; 6,000g/mol or more; 7,000g/mol or more; 8,000g/mol or more; 9,000g/mol or more; 10,000g/mol or more; 15,000g/mol or more; 20,000g/mol or more; 30,000g/mol or more; 40,000g/mol or more; or a weight average molecular weight (Mw) of 45,000g/mol or more. Suitable polymeric friction modifiers may also have a molecular weight ranging from a lower limit of about 3,000g/mol, about 4,000g/mol, or about 5,000g/mol to about 10,000g/mol; an upper limit of about 30,000g/mol, or about 50,000g/mol. Suitable polymeric friction modifiers may also have a molecular weight of about 3,000g/mol to 15,000g/mol; about 4,000g/mol to about 12,000g/mol; about 3,000g/mol to about 9,000g/mol; about 3,000g/mol to about 7,000g/mol. Suitable polymeric friction modifiers may also have a molecular weight of about 3,000g/mol, about 4,000g/mol, about 5,000g/mol, about 6,000g/mol, about 7,000g/mol, about 8,000g/mol, or about 9,000g/mol. Particularly suitable polymeric friction modifiers are or include ethylene oxide (ETO), oligomers of ethylene oxide, or polymers of ethylene oxide.

Other additives

The engine oil lubricant composition may also include one or more other additives typically used in engine oils. These other additives may include any one or more of anti-wear additives, dispersants, detergents, antioxidants, pour point depressants, corrosion inhibitors, anti-rust additives, metal deactivators, seal compatibility additives, and antifoamants. These other additives may be provided to the lubricant composition in the form of an additive package. The additive package may be incorporated into the engine lubricant composition at a loading of from about 9 wt.% to about 15 wt.%, or from about 10 to about 14.5 wt.%, or from about 11 to about 14 wt.%, based on the total weight of the composition. The additive package may also be incorporated into the engine lubricant composition at a loading of from a lower limit of about 5 wt.%, about 7 wt.%, about 9 wt.%, or about 10 wt.% to an upper limit of about 11 wt.%, about 14 wt.%, about 14.5 wt.%, or about 15 wt.%, based on the total weight of the composition.

Antiwear agent

Although there are many different types of anti-wear additives, for decades, the primary anti-wear additive used in internal combustion engine crankcase oils has been metal alkyl thiophosphates, and more particularly metal dialkyl dithiophosphates, wherein the metal component is zinc, or Zinc Dialkyl Dithiophosphate (ZDDP). ZDDP may be primary, secondary or mixtures thereof. ZDDP compounds typically have the formula Zn [ Sp (S) (OR) ¹ )(OR ² )] ₂ Wherein R is ¹ And R ² Is C ₁ -C ₁₈ Alkyl, preferably C ₂ -C ₁₂ An alkyl group. These alkyl groups may be straight or branched chain alkyl groups. ZDDP's are typically used in amounts of about 0.4 to 1.4 wt.% of the total lubricating oil composition, although more or less may generally be advantageously used. Preferably, ZDDP is secondary ZDDP and is present in an amount of about 0.6 to 1.0 wt.%, or 0.6 to 0.91 wt.%, of the total lubricant composition.

Commercially available preferred zinc dithiophosphates include zinc secondary dithiophosphates such as those available under The trade names "LZ 677A", "LZ 1095" and "LZ 1371" from, for example, the Lubrizol Corporation, under The trade name "OLOA 262" from, for example, chevron Oronite and under The trade name "Hitec 7169" from, for example, after Chemical.

Dispersing agent

During engine operation, oil-insoluble oxidation byproducts are produced. The dispersant helps to keep these by-products in solution, thereby reducing their deposition on the metal surface. The dispersants may be ashless or ash-forming in nature. Preferably, the dispersant is ashless. So-called ashless dispersants are organic materials that do not substantially form ash on combustion. For example, metal-free or borated metal-free dispersants are considered ashless. In contrast, the above-described metal-containing detergents form ash upon combustion.

Suitable dispersants typically contain polar groups attached to higher molecular weight hydrocarbon chains. The polar group generally contains at least one element of nitrogen, oxygen, or phosphorus. Typical hydrocarbon chains contain 50 to 400 carbon atoms.

Chemically, many dispersants can be characterized as phenates, sulfonates, sulfurized phenates, salicylates, naphthenates, stearates, carbamates, thiocarbamates, phosphorus derivatives. One particularly useful class of dispersants are alkenyl succinic acid derivatives, typically prepared by the reaction of a long chain substituted alkenyl succinic compound (typically a substituted succinic anhydride) with a polyhydroxy or polyamino compound. The long chain group that constitutes the lipophilic part of the molecule, which imparts solubility in oils, is typically a polyisobutylene group. Many examples of such dispersants are well known commercially and in the literature. Exemplary U.S. patents that describe such dispersants are 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 dispersants 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. Another description of dispersants can be found, for example, in European patent application No. 471071, to which reference is made for this purpose.

Hydrocarbyl-substituted succinic acid compounds are common dispersants. In particular, succinimides, succinate esters, or succinate amides prepared by the reaction of a hydrocarbon-substituted succinic compound, preferably containing 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 alkenyl succinic anhydrides and amines. The molar ratio may vary depending on the polyamine. For example, the molar ratio of alkenyl succinic anhydride to polyvinylamine (TEPA, tetraethylenepentamine) can vary from about 1 to about 5. 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 canadian patent No. 1,094,044.

The succinate is formed by a condensation reaction between an alkenyl succinic anhydride and an alcohol or polyol. The molar ratio may vary depending on the alcohol or polyol used. For example, condensation products of alkenyl succinic anhydrides and pentaerythritol are useful dispersants.

The succinate amide is formed by a condensation reaction between an alkenyl succinic anhydride and an alkanolamine. For example, suitable alkanolamines include ethoxylated polyalkyl polyamines, propoxylated polyalkyl polyamines, and polyalkenyl polyamines such as polyethylene polyamines. One example is propoxylated hexamethylenediamine. Representative examples are shown in U.S. Pat. No. 4,426,305.

The alkenyl succinic anhydrides used in the preceding paragraph typically have a molecular weight of from 800 to 2,500g/mol. The above products can be post-reacted with various agents such as sulfur, oxygen, formaldehyde, carboxylic acids such as oleic acid and boron compounds such as borate esters or highly borated dispersants. The dispersant may be borated with 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 an alkylphenol, formaldehyde, and an amine. See U.S. Pat. No. 4,767,551, which is incorporated herein by reference. Processing aids and catalysts, such as oleic acid and sulfonic acid, may also be part of the reaction mixture. The alkylphenol has a molecular weight of 800 to 2,500g/mol. 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 the present invention may be hydroxy aromatic compounds substituted with high molecular weight alkyl groups or containing HN (R) ₂ Reactant preparation of the radicals.

Hydrocarbyl-substituted amine ashless dispersant additives are well known to those skilled in the art; see, e.g., 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 derived 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 polyisobutylenes having a number average molecular weight (Mn) of about 500 to about 5000g/mol or mixtures of these hydrocarbylene groups. Other preferred dispersants include succinic acid esters and amides, alkylphenol-polyamine coupled mannich adducts, their capped derivatives, and other related components. Such additives may be used in an amount of about 0.1 to 20% by weight, preferably about 0.5 to 8% by weight.

Detergent composition

Detergents are commonly used in lubricating compositions. Typical detergents are anionic materials that contain 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 sulfuric acid, carboxylic acid, phosphorous acid, phenol, or mixtures thereof. The counter ion is typically an alkaline earth metal or an alkali metal.

Salts containing a substantially stoichiometric 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 80mg KOH/g. It is desirable that at least some detergents are overbased, meaning that the detergents contain a significant amount of metal base obtained by reacting an excess of a metal compound (e.g., a metal hydroxide or oxide) with an acidic gas (e.g., carbon dioxide). Overbased detergents help neutralize acidic impurities produced by the combustion process and are trapped in the oil. Typically, the overbased material has a ratio of metal ion to anionic portion based on an equivalent weight of about 1.05. More preferably, the ratio is from about 4. The resulting detergent is an overbased detergent, which will typically have greater than 80mg KOH/g, for example 80 to 450;85 to 450 or 150 to 450mg KOH/g TBN. Useful detergents may also have a TBN ranging from a lower limit of about 81mg KOH/g, about 90mg KOH/g, or about 100mg KOH/g to an upper limit of about 200, 300, or 450mg KOH/g. Preferably, the overbased cation is sodium (Na), calcium (Ca), or magnesium (Mg). Mixtures of detergents of different TBN may also be used.

Preferred detergents include alkali or alkaline earth metal sulfonates, phenates, carboxylates, phosphates, and salicylates. Sulfonates can be prepared from sulfonic acids, which are typically obtained by sulfonation of alkyl-substituted aromatic hydrocarbons. Examples of hydrocarbons include those obtained by alkylating benzene, toluene, xylene, naphthalene, biphenyl, and halogenated derivatives thereof (e.g., chlorobenzene, chlorotoluene, and chloronaphthalene). The alkylating agent generally has from about 3 to 70 carbon atoms. The alkylaryl sulfonates typically contain from about 9 to about 80 carbon atoms or more, more typically from about 16 to 60 carbon atoms.

Klamann discloses in the previously cited "lubricating and Related Products" a number of overbased metal salts of various sulfonic acids which are useful as detergents and dispersants in Lubricants. A book entitled "Lubricant Additives", c.v. smallher and r.k.smith, published by Leziushiles co.of Cleveland, ohio (1967), similarly discloses a number of overbased sulfonates which are useful as dispersants/detergents.

Alkaline earth metal phenates are another useful class of detergents. These detergents may be prepared by reacting alkaline earth metal hydroxides or oxides (e.g., caO, ca (OH) ₂ 、BaO、Ba(OH) ₂ 、MgO、Mg(OH) ₂ ) With an alkylphenol or sulfurized alkylphenol. Useful alkyl groups include straight or branched C ₁ -C ₃₀ Alkyl, preferably C ₄ -C ₂₀ . Examples of suitable phenols include isobutylphenol, 2-ethylhexyl phenol, nonylphenol, dodecylphenol, and the like. It should be noted that the starting alkylphenol may contain more than one alkyl substituent each independently being a straight or branched chain. When non-sulfurized alkylphenols are used, the sulfurized product can be obtained by methods well known in the art. These methods involve heating a mixture of an alkylphenol and a 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.

Metal salts of carboxylic acids may also be used as 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 levels. 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 has the following structure:

structure 1: structural examples of salicylates

In structure 1 above, R is a hydrogen atom or an alkyl group containing from 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 at least C ₁₁ Preferably C ₁₃ Or larger alkyl chains. R may optionally be substituted with substituents that do not interfere with the function of the detergent. M is preferably calcium, magnesium or barium. More preferably, M is calcium.

Hydrocarbyl-substituted salicylic acids can be prepared from phenols by the kolbe reaction (see U.S. Pat. No. 3,595,791). Metal salts of hydrocarbyl-substituted salicylic acids can be prepared by metathesis of the metal salt in a polar solvent such as water or an alcohol.

Alkaline earth metal phosphates may also be used as detergents.

The detergent may be a simple detergent or a so-called hybrid or complex detergent. The latter detergents may provide the properties of both detergents without the need to blend separate materials. See, for example, U.S. Pat. No. 6,034,039.

Preferred detergents may include calcium phenates, calcium sulfonates, calcium salicylates, magnesium phenates, magnesium sulfonates, magnesium salicylates, and other related components (including borated detergents). Typically, the total detergent concentration is about 0.01 to about 6.0 wt.%, or 0.01 to 4 wt.%, or 0.01 to 3 wt.%, or 0.01 to 2.2 wt.%, or 0.01 to 1.5 wt.%, preferably about 0.1 to 3.5 wt.%.

Antioxidant agent

Antioxidants retard the oxidative degradation of base oils during use. This degradation may result in deposits on the metal surfaces, the presence of sludge, or an increase in the viscosity of the lubricant. Those skilled in the art are aware of the various oxidation inhibitors that can be used in lubricating oil compositions. See, for example, klamann in Lubricants and Related Products, and U.S. Pat. Nos. 4,798,684 and 5,084,197, cited previously.

Useful antioxidants may 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 sterically hindered phenols, which are those containing sterically hindered hydroxyl groups, and these include those derivatives of dihydroxyaryl compounds in which the hydroxyl groups are in the ortho or para position to each other. Typical phenolic antioxidants include comforters C ₆ + alkyl substituted hindered phenols and alkylene coupled derivatives of these hindered phenols. Examples of phenolic materials of this type are 2-tert-butyl-4-heptylphenol; 2-tert-butyl-4-octylphenol; 2-tert-butyl-4-dodecylphenol; 2, 6-di-tert-butyl-4-heptylphenol; 2, 6-di-tert-butyl-4-dodecylphenol; 2-methyl-6-tert-butyl-4-heptylphenol; and 2-methyl-6-tert-butyl-4-dodecylphenol. Other useful hindered monophenol antioxidants may include, for example, hindered 2, 6-dialkylphenol propionate derivatives. Bisphenol antioxidants may also be advantageously used in combination with the present invention. Examples of ortho-coupled phenols include: 2,2' -bis (4-heptyl-6-butyl-phenol); 2,2' -bis (4-octyl-6-butyl-phenol); and 2,2' -bis (4-dodecyl-6-tert-butyl-phenol). Para-coupled bisphenols include, for example, 4 '-bis (2, 6-di-tert-butylphenol) and 4,4' -methylene-bis (2, 6-di-tert-butylphenol).

Non-phenolic oxidation inhibitors that may be used include aromatic amine antioxidants, and these may be used as such or in combination with phenols. Typical examples of non-phenolic antioxidants include: alkylated and non-alkylated aromatic amines, e.g. of the formula R ⁸ R ⁹ R ¹⁰ Aromatic monoamines of N, wherein R ⁸ Is an aliphatic, aromatic or substituted aromatic radical, R ⁹ Is an aromatic or substituted aromatic radical, R ¹⁰ Is H, alkyl, aryl or R ¹¹ S(O)xR ¹² Wherein R is ¹¹ Is alkylene, alkenylene or aralkylene, R ¹² Is a higher alkyl, or alkenyl, aryl or alkaryl group, x is 0,1 or 2. Aliphatic radical R ⁸ May contain from 1 to about 20 carbon atoms, preferably from about 6 to 12 carbon atoms. The aliphatic group is a saturated aliphatic group. Preferably, R ⁸ And R ⁹ Are all aromatic or substituted aromatic groups, and the aromatic groups may be fused ring aromatic groups, such as naphthyl. Aromatic radical R ⁸ And R ⁹ May be linked together with other groups such as sulfur.

Typical aromatic amine antioxidants have alkyl substituents containing at least about 6 carbon atoms. Examples of aliphatic groups include hexyl, heptyl, octyl, nonyl, and decyl. Typically, the aliphatic group will contain no more than about 14 carbon atoms. Typical types of amine antioxidants useful in the compositions of the present invention include diphenylamine, phenylnaphthylamine, phenothiazine, iminodibenzyl, and diphenylphenylenediamine. Mixtures of two or more aromatic amines are also useful. Polymeric amine antioxidants may also be used. Specific examples of aromatic amine antioxidants useful in the present invention include: p, p' -dioctyldiphenylamine; tert-octylphenyl-alpha-naphthylamine; phenyl-alpha-naphthylamine; and p-octylphenyl-alpha-naphthylamine. Sulfurized alkylphenols and their alkali or alkaline earth metal salts may also be useful antioxidants.

Preferred antioxidants include sterically hindered phenols, aryl amines. These antioxidants may be used alone or in combination with each other by type.

Antioxidants may be used in amounts of about 0.01 to 5 weight percent, preferably about 0.01 to 1.5 weight percent, more preferably 0 to less than 1.5 weight percent, most preferably 0, based on the total weight of the engine oil lubricant.

Pour point depressant

Conventional pour point depressants (also known as lube oil flow improvers) may be added to the compositions of the present invention if desired. These pour point depressants may be added to the lubricating composition of the present invention 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 halogenated paraffins and aromatics, vinyl carboxylate polymers and terpolymers of dialkyl fumarates, 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 their preparation. These additives may be used in amounts of about 0.01 to 5 wt%, preferably about 0.01 to 1.5 wt%, based on the total weight of the engine oil lubricant.

Corrosion Inhibitors (CI)

One or more corrosion inhibitors may be added to the lubricating oil composition. Corrosion inhibitors are additives that protect lubricated metal surfaces from chemical attack by water or other contaminants. Corrosion inhibitors may also be used to reduce degradation of metal parts in contact with the lubricating oil composition. Corrosion inhibitors, as used herein, include rust inhibiting additives, metal deactivators, and metal deactivators.

One type of corrosion inhibitor is a polar compound that preferentially wets the metal surface, protecting it with an oil film. Another type of corrosion inhibitor absorbs water by incorporating it into a water-in-oil emulsion so that only the oil contacts the metal surface. Another type of corrosion inhibitor chemically adheres to metals to create a non-reactive surface. Suitable corrosion inhibitors include organic salts including zinc dithiophosphates, metal phenolates, neutral metal sulfonates (e.g., calcium sulfonate, magnesium sulfonate, barium sulfonate, zinc sulfonate, etc.), metal naphthenates (e.g., zinc naphthenate, barium naphthenate, calcium naphthenate, magnesium naphthenate, etc.), fatty acids, and amines. Other suitable corrosion inhibitors include, for example, arylthiazines, alkyl-substituted dimercaptothiadiazoles, thiazoles, triazoles, nonionic polyoxyalkylene polyols and esters thereof, polyoxyalkylene phenols, anionic alkyl sulfonic acids, and the like, and mixtures thereof.

Illustrative corrosion inhibitors may include, for example, (short chain) alkyl and alkenyl succinic acids, partial esters thereof, and nitrogen-containing derivatives thereof; and petroleum sulfonates, synthetic alkylaryl sulfonates such as metal alkylbenzenesulfonates and metal dinonylnaphthalenesulfonates. Corrosion inhibitors also include, for example, monocarboxylic acids containing 8 to 30 carbon atoms, alkyl or alkenyl succinic acid esters or partial esters thereof, hydroxy fatty acids containing 12 to 30 carbon atoms and derivatives thereof, sarcosines containing 8 to 24 carbon atoms and derivatives thereof, amino acids and derivatives thereof, naphthenic acids and derivatives thereof, lanolin fatty acids, mercapto fatty acids, and paraffin oxides.

Particularly preferred corrosion inhibitors include, for example, monocarboxylic acids (C) ₈ -C ₃₀ ) Octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, cerotic acid, montanic acid, melissic acid, oleic acid, behenic acid, erucic acid, eicosenoic acid, tallow fatty acid, soy fatty acid, coconut fatty acid, linoleic acid, tall oil fatty acid, 12-hydroxystearic acid, lauryl sarcosine, myristyl sarcosine, palmityl sarcosine, stearyl sarcosine, oleyl sarcosine, alkylation (C) ₈ -C ₂₀ ) Phenoxyacetic acid, lanolin fatty acid and C ₈ -C ₂₄ Mercapto-fatty acids.

Examples of the polycarboxylic acid serving as the corrosion inhibitor include alkenyl (C) ₁₀ -C ₁₀₀ ) Succinic acid and its ester derivatives, dimer acid, N-acyl-N-alkoxyalkyl aspartate (U.S. Pat. No. 5,275,749). Alkanes acting as corrosion inhibitors or as reaction products with the above-mentioned carboxylates to give amides and the likeExamples of the amines are represented by primary amines such as laurylamine, cocoamine, n-tridecylamine, tetradecylamine, n-pentadecylamine, palmitylamine, n-heptadecylamine, stearylamine, n-nonadecylamine, n-eicosylamine, n-heneicosylamine, n-docosylamine, n-tricosylamine, n-pentacosylamine, oleylamine, tallow amine, hydrogenated tallow amine and soybean amine. Examples of secondary amines include dilaurylamine, dicocoamine, di-n-tridecylamine, dimyristylamine, di-n-pentadecylamine, dipalmitylamine, di-n-pentadecylamine, distearylamine, di-n-nonadecylamine, di-n-eicosylamine, di-n-heneicosylamine, di-n-docosylamine, di-n-tricosylamine, di-n-pentacosylamine, dioleylamine, ditallowamine, dihydrotallow amine, and soyamine. The above-mentioned alkylene diamine, alkylated alkylene diamine and N-alkyl polyalkylene diamine include: ethylenediamine such as lauryl ethylenediamine, coconut ethylenediamine, N-tridecyl ethylenediamine, myristyl ethylenediamine, N-pentadecyl ethylenediamine, palmityl ethylenediamine, N-heptadecyl ethylenediamine, stearyl ethylenediamine, N-nonadecyl ethylenediamine, N-eicosyl ethylenediamine, N-heneicosyl ethylenediamine, N-docosyl ethylenediamine, N-tricosyl ethylenediamine, N-pentacosyl ethylenediamine, oleyl ethylenediamine, tallow-ethylenediamine, hydrogenated tallow-ethylenediamine and soybean-ethylenediamine; propylenediamines, such as lauryl propylenediamine, coco propylenediamine, N-tridecylpropyldiamine, myristyl propylenediamine, N-pentadecylpropyldiamine, palmityl propylenediamine, N-heptadecyl propylenediamine, stearyl propylenediamine, N-nonadecyl propylenediamine, N-eicosylpropyldiamine, N-heneicosyl propylenediamine, N-docosylpropanediamine, N-tricosyl propylenediamine, N-pentacosylpropanediamine, diethylenetriamine (DETA) or triethylenetetramine (TETA), oleyl propylenediamine, tallow-propylenediamine, hydrogenated tallow-propylenediamine and soybean-propylenediamine; butanediamines, e.g. lauryl butanediamine, coco butanediamine, N-tridecyl butanediamine, myristyl butanediamine, N-pentadecyl butanediamine, stearyl butanediamine, N-eicosyl butanediamine, N-heneicosyl butanediamine, N-docosyl butanediamine, N-tricosyl butanediamine, N-eicosyl butanediamine, N-tricosyl butanediamine, N-icosyl butanediaminePentaalkyl butanediamine, oleyl butanediamine, tallow butanediamine, hydrogenated tallow butanediamine and soy butanediamine; and pentanediamines such as laurylpentylene diamine, cocoylpentylene diamine, myristyl pentanediamine, palmitylpentylene diamine, stearyl pentanediamine, oleyl pentadiamine, tallow-pentadiamine, hydrogenated tallow-pentadiamine, and soy pentadiamine.

Other exemplary corrosion inhibitors include 2, 5-dimercapto-1, 3, 4-thiadiazole and its derivatives, mercaptobenzothiazole, alkyltriazole, and benzotriazole. Examples of diacids useful as corrosion inhibitors for use in the present disclosure are sebacic acid, adipic acid, azelaic acid, dodecanedioic acid, 3-methyladipic acid, 3-nitrophthalic acid, 1, 10-decanedicarboxylic acid, and fumaric acid. The corrosion inhibitor may be a linear or branched, saturated or unsaturated monocarboxylic acid or ester thereof, optionally sulfurized in an amount of up to 35 wt%. Preferably, the acid is C ₄ To C ₂₂ A linear unsaturated monocarboxylic acid. Preferred concentrations of such additives are from 0.001 wt.% to 0.35 wt.% of the total lubricant composition. The preferred monocarboxylic acid is sulfurized oleic acid. Alternatively, other suitable materials include oleic acid itself, valeric acid, and erucic acid. Exemplary corrosion inhibitors include triazoles as previously defined. The triazole should be used at a concentration of 0.005 to 0.25% by weight of the total composition. The preferred triazole is tolyltriazole, which is suitably included in the compositions of the present disclosure. Also suitably included in the composition are triazoles, thiazoles and certain diamine compounds which are useful as metal deactivators or metal deactivators. Examples include triazoles, benzotriazoles and substituted benzotriazoles such as alkyl substituted derivatives. The alkyl substituents generally contain up to 15 carbon atoms, preferably up to 8 carbon atoms. The triazole optionally contains other substituents on the aromatic ring, such as halogen, nitro, amino, mercapto, and the like. Examples of suitable compounds are benzotriazole and tolyltriazole, ethylbenzotriazole, hexylbenzotriazole, octylbenzotriazole, chlorobenzotriazole and nitrobenzotriazole. Benzotriazole and tolyltriazole are particularly preferred. Optionally sulfurized linear or branched saturated or unsaturated monocarboxylic acid in an amount of up to 35% by weight; or an ester of such an acid; and triazoles or alkyl derivatives thereofBio, or short chain alkyl of up to 5 carbon atoms; n is 0 or an integer between 1 and 3, including 1 and 3; and is hydrogen, morpholinyl, alkyl, amido, amino, hydroxy, or an alkyl or aryl substituted derivative thereof; or a triazole selected from 1,2, 4-triazole, 1,2, 3-triazole, 5-aniline-1, 2,3, 4-thiatriazole, 3-amino-1, 2, 4-triazole, 1-H-benzotriazol-1-yl-methyl isocyanide, methylene-bis-benzotriazole, and naphthotriazole.

Other illustrative corrosion inhibitors may include 2-mercaptobenzothiazole, dialkyl-2, 5-dimercapto-1, 3,4 thiadiazole; n, N ' -disalicylidene ethylenediamine, N ' -disalicylidene propylenediamine, N-salicylidene ethylamine, N ' -disalicylidene ethylenediamine; triethylenediamine, ethylenediaminetetraacetic acid; zinc dialkyldithiophosphates and zinc dialkyldithiocarbamates, and the like.

Other illustrative corrosion inhibitors may include yellow metal passivators. The term "yellow metal" refers to a metallurgical group including, for example, brass and bronze alloys, aluminum bronze, phosphor bronze, copper nickel alloys, beryllium copper, and the like. Typical yellow metal deactivators include, for example, benzotriazole, tolyltriazole, mixtures of sodium tolyltriazole and tolyltriazole, imidazoles, benzimidazoles, imidazolines, pyrimidines and derivatives thereof, and combinations thereof. In a specific and non-limiting embodiment, tolyltriazole containing compounds are selected.

One or more metal corrosion inhibitors may be present in an amount of about 0.01 wt.% to about 5.0 wt.%, preferably about 0.01 wt.% to about 3.0 wt.%, more preferably about 0.01 wt.% to about 1.5 wt.%, based on the total weight of the engine oil lubricant composition.

Seal compatibility agent

The seal compatiblizer helps swell the elastomer seal by causing a chemical reaction in the fluid or a physical change in the elastomer. Suitable seal compatibility agents for lubricating oils include organophosphates, aromatic esters, aromatic hydrocarbons, esters (e.g., butyl benzyl phthalate) and polybutenyl succinic anhydride. These additives may be used in amounts of about 0.01 to 3 wt%, preferably about 0.01 to 2 wt%, based on the total weight of the engine oil lubricant.

Defoaming

An anti-foaming agent may advantageously be added to the lubricant composition. These agents retard the formation of stable foams. Silicones and organic polymers are typical defoamers. For example, polysiloxanes, such as silicone oils or polydimethylsiloxanes, provide defoaming properties. Defoamers are commercially available and can be used in conventional small amounts with other additives such as demulsifiers; typically, the combined amount of these additives is less than 1 wt.%, typically less than 0.1 wt.%, based on the total weight of the engine oil lubricant composition.

When the lubricating oil composition contains any one or more of the above-described additives, the additive(s) are blended into the composition in an amount sufficient to perform their intended function. Illustrative amounts of such additives useful in the engine oil lubricants described herein are shown in table 1 below.

It should be noted that many additives are shipped from the manufacturer and used in the formulation with a certain amount of base oil diluent. Thus, the weights in table 2, as well as other amounts referred to in this specification, refer to the amount of active ingredient (i.e., the non-diluent portion of the composition). The wt.% indicated below are based on the total weight of the lubricating oil composition.

Table 2: typical amounts of various lubricating oil components

The foregoing additives may be added separately or may be pre-combined in a package available from the supplier of the lubricating oil additives. Additive packages are available in various ingredients, proportions and characteristics, and the selection of a suitable package will take into account the necessary use of the final composition. The additive package may be incorporated into an engine oil lubricant composition at a loading of from about 9 wt.% to about 15 wt.%, or from about 10 to about 14.5 wt.%, or from about 11 to about 14 wt.%, based on the total weight of the lubricant composition.

Examples

The above discussion may be further described with reference to the following non-limiting examples. In the following examples, a 0.5 wt.% sulfated ash 5W-30 base formulation (i.e., a "low ash" formulation) was investigated for fuel economy and therefore CO using organic friction modifiers in combination with different detergents and corrosion inhibitors ₂ The effect of emissions.

Two 0.5 wt% sulfated ash 5W-30 base formulations, base formulation 1 ("BF 1") and base formulation 2 ("BF 2") were prepared. BF1 and BF2 were the same except that BF2 also contained 0.7 wt% of a mixed glyceride friction modifier. BF1 and BF2 were formulated with 64mg KOH/g ASTM D2896 calcium salicylate detergent (2.3% Ca) as sole detergent additive. Table 3 summarizes the BF1 and BF2 formulations and the ash content and fuel economy measured for each.

Table 3: lubricant formulations and fuel economy test results

Ash content is measured according to ASTM D874. The sulfated ash value was calculated using the following factor (F): ca-3.4, mg-4.95, B-3.22, zn-1.25, mo-1.5, where the calculated sulfated ash is given by equation 1.

Calculated sulphated ash (% by weight) = Σ M _i ·F _i Eq.1

Wherein M is _i Equal to the metal concentration in% by weight, F _i Equal to the sulphated ash factor of the metal.

Table 3 shows that the presence of a mixed glyceride friction modifier in BF2 produces a significant increase in fuel economy as measured by the ASTM-D8114 Sequence VIE fuel economy test in the presence of 64mg KOH/g of ASTM D2896 TBN calcium salicylate detergent. Having 0.7 wt.% mixed glyceride compared to BF1 (without mixed glyceride friction modifier)The initial fuel economy (FEI 1) and aged fuel economy (FEI 2) of BF2 of the friction modifier increased significantly. This significant increase in fuel economy necessarily results in significantly reduced CO ₂ And (4) discharging.

Eight different corrosion inhibitors (additives 1 to 8) were then added to the BF2 formulation to determine the effect on corrosion protection as determined by ASTM D6557. Additive 1 is an imidazoline, which is the reaction product of oleic acid and amino-ethyl 2-ethylhexyl amine, and has no pendant organic acid groups.

Additives 2,3 and 7 contain organic acid groups. Specifically, additive 2 is the imidazoline reaction product of oleic acid and aminoethyl 2-ethylhexylamine plus free oleic acid. Additive 3 is C reacted with 1,3 propylene glycol ₁₆ Alkylated succinic anhydrides. Additive 7 is an ashless ester/amide/carboxylate having the structure:

structure 2: structural example of additive 7

(wherein R is a mixture of n-C8 and n-C10)

Additives 4,5, 6 and 8 are organic salts (organometallic molecules) having an ASTM D2896 Total Base Number (TBN) of less than 3mg KOH/g. Specifically, additive 4 is a barium salt of dinonylnaphthalene sulfonic acid having an ASTM D2896 TBN of less than 1mg KOH/g and a Ba content of 6.65 wt.%. Additive 5 was zinc dinonylnaphthalenesulfonate having an ASTM D2896 TBN of 1.9mg KOH/g and a Zn content of 2.9% by weight. Additive 6 was zinc naphthenate having an ASTM D2896 TBN of 2.9mg KOH/g, a Zn content of 10% by weight. Additive 8 was calcium dinonylnaphthalenesulfonate having an ASTM D2896 TBN of less than 1mg KOH/g and a Ca content of 2.1% by weight.

Table 4 summarizes the lubricant formulations and the ball rust test results measured according to ASTM D6557. All weights are weight percent based on the total weight of the lubricant.

TABLE 4 formulation overview of ASTM D6557 BRT test (AGV)

Base formulation 2 had an ASTM D6557 steel corrosion performance of 33AGV. This is considered to be a poor result; however, this is not unexpected because the formulation ash level of 0.5% is low. As shown in table 4 above, the addition of 1 wt% of additives 1 to 8 to base formulation 2 increased the steel corrosion performance (AGV) to 40, 60, 79, 57, 82, 88, 52 and 65, respectively. The AGV results for additives 2 to 8 are significantly improved. Addition of only 0.5 wt% of additive 1 did not improve the steel corrosion performance (AGV down to 19).

The addition of 0.5 wt% of each additive, 1 to 8, changed the AGV results to 19, 76, 77, 66,74, 76, 70 and 68 AGVs, respectively. Additive 1 did not improve corrosion performance. The results of additives 2 to 8 are significantly improved.

The addition of 0.2 wt% of additives 2,3, 6,7 and 8 significantly improved the AGV results to 76, 69, 64, 60 and 74 AGVs, respectively.

The addition of 0.05 wt% of additives 2,3, 6,7 and 8 changed the AGV results to 72, 62, 74, 52 and 74 AGVs respectively, which is a significant improvement and similar to the improvement obtained with the addition of 0.2 wt% of these same additives.

Two other detergents were studied in combination with additive 3 (C16 alkylated succinic anhydride, reacted with 1,3 propylene glycol) in a 0.5 wt% sulfated ash 5W-30 base formulation ("BF 3"). In these examples, BF3 was similar to BF2 except that the 64mg KOH/g calcium TBN salicylate detergent in BF2 was replaced with 405mg KOH/g magnesium TBN sulfonate detergent and 300mg KOH/g calcium TBN sulfonate detergent in the amounts reported in table 5 below. 405Mg KOH/g magnesium TBN sulfonate detergent contained 9.1 wt.% Mg and 300Mg KOH/g calcium TBN sulfonate detergent contained 11.6 wt.% Ca. The amount of each detergent was selected to provide a sulfated ash value of 0.5% to a fully formulated lubricant. For these formulations, 0.05 wt% of additive 3 was used.

Optional detergent combinations evaluated in BRT

	CEx.4	CEx.5	CEx.6	Ex.25	Ex.26	Ex.27
							Base oil, wt.%	80.28	80.17	80.23	80.23	80.12	80.18
Mixed glyceride friction modifier,% by weight	0.7	0.7	0.7	0.7	0.7	0.7
							Other additives, wt.%	18.26	18.26	18.26	18.26	18.26	18.26
Additive 3% by weight				0.05	0.05	0.05
							Sulfonic acid Mg,405TBN,% by weight	0.76		0.38	0.76		0.38
Ca sulfonate, 300TBN,% by weight		0.87	0.43		0.87	0.43
							BRT AGV,％	41	29	33	47	35	39

These additives were then tested to determine their effectiveness for corrosion protection as determined by the ASTM D6557 ball rust test (ASTM D6557 BRT).

Using 405mg KOH/g magnesium TBN sulfonate detergent (CEx. 4), the BRT result was 41. The addition of 0.05 wt% additive 3 (ex.25) increased the BRT result from 41AGV to 47AGV. Using 300mg KOH/g calcium TBN sulfonate detergent (CEx. 5), the BRT result was 29. Addition of 0.05 wt% additive 3 (ex.26) increased the BRT results from 29 AGVs to 35 AGVs. Using a mixture of 405mg KOH/g magnesium TBN sulfonate detergent and 300TBN calcium sulfonate detergent (CEx. 6), the BRT result was 33. Addition of 0.05 wt% additive 3 (ex.27) increased the BRT results from 33 AGVs to 39 AGVs.

These formulations show that additives that provide BRT benefits to calcium salicylate (ex.1 to 24) also provide benefits to magnesium sulfonate (ex.25), calcium sulfonate (ex.26) or a mixture of magnesium sulfonate and calcium sulfonate (ex.27). This is a significant benefit for formulating engine oils with all or a mixture of magnesium or calcium.

It was also unexpected that organic salt (organo) naphthalene additives (additives 4,5, 6 and 8) with very low TBN values (less than 3mg KOH/g) were effective in ball rust tests conducted in the presence of organic and inorganic acids. TBN is generally associated with the ability to neutralize acidic species to prevent corrosion. The higher the TBN, the better the ability to neutralize acidity. Since additives 4,5, 6 and 8 had TBN less than 3mg KOH/g and those additives caused an increase in BRT, the results imply that these improvements were not from acid neutralization, which is entirely surprising and unexpected.

Even more unexpectedly, additives 2,3, and 7 provided effective BRT results of 19 or greater. Additives 2,3 and 7 contain organic acid groups, which are known to promote corrosion, e.g. lead corrosion. It is entirely surprising and unexpected that additives 2,3 and 7 having organic acid groups provide effective corrosion results in the presence of calcium salicylate detergents and mixed glyceride friction modifiers, which exhibit excellent fuel economy and thus reduced CO ₂ And (5) discharging.

Certain embodiments and features have been described using a set of numerical upper limits and a set of numerical lower limits. It is self-evident that ranges including any combination of two values, e.g., any combination of any lower value with any upper value, any combination of two lower values, and/or any combination of two upper values, are contemplated unless otherwise indicated. Certain lower limits, upper limits and ranges appear in one or more claims below. All numerical values are "about" or "approximately" indicative values and take into account experimental error and deviation as would be expected by one of ordinary skill in the art.

Various terms have been defined above. To the extent a term used in a claim is not defined above, it should be given the broadest definition persons in the pertinent art have given that term as reflected in at least one printed publication or issued patent. In addition, all patents, test procedures, and other documents cited in this application are fully incorporated by reference to the extent such disclosure is not inconsistent with this invention and for all jurisdictions in which such incorporation is permitted.

While certain preferred embodiments of the present invention have been illustrated and described in detail above, it will be apparent that modifications and adaptations thereof will occur to those skilled in the art. It is, therefore, to be clearly understood that such modifications and adaptations may be devised without departing from the basic scope thereof, and the scope thereof may be determined by the claims that follow.

Claims

1. An engine oil lubricant composition comprising:

about 40 wt% to about 90 wt% of at least one base oil;

about 0.1 wt% to about 5 wt% of an organic friction modifier;

about 1 wt% to about 6 wt% of at least one detergent comprising magnesium or calcium;

from about 0.01% to about 1% by weight of a corrosion inhibitor having at least one organic acid moiety or an organic salt thereof;

wherein the engine oil lubricant composition has a sulfated ash content of 0.5 wt.% or less and an HTHS of less than or equal to 3.7cP at 150 ℃ (ASTM D4683).

2. The lubricant composition of claim 1, wherein the at least one detergent has a total base number (TBN, measured by ASTM D2896) of from 50mg KOH/g to 100mg KOH/g.

3. The lubricant composition of any one of claims 1 to 2 wherein the at least one detergent comprises magnesium or calcium sulfonate or calcium salicylate or mixtures thereof.

4. The engine lubricating oil of any one of claims 1 to 3, wherein the corrosion inhibitor having naphthenate, naphthalene sulfonate, or at least one organic acid or organic salt moiety improves the ball rust test (ASTM D6557) Average Gray Value (AGV) by at least 25%.

5. The engine oil of any of claims 1 to 4, wherein the corrosion inhibitor having naphthenate, naphthalene sulfonate, or at least one organic acid or organic salt moiety improves the ball rust test (ASTM D6557) Average Grey Value (AGV) by at least 50%.

6. The engine lubricating oil of any one of claims 1 to 5, wherein the corrosion inhibitor having naphthenate, naphthalene sulfonate, or at least one organic acid or organic salt moiety improves the ball rust test (ASTM D6557) Average Gray Value (AGV) by at least 100%.

7. The engine lubricating oil of any one of claims 1 to 6, wherein the corrosion inhibitor has at least one organic acid or salt of an alkyl or alkylene substituted naphthenate or naphthalene sulfonate moiety.

8. The engine lubricating oil of any one of claims 1 to 7, wherein the corrosion inhibitor is zinc naphthenate.

9. The engine lubricating oil of any one of claims 1 to 7, wherein the corrosion inhibitor is a barium salt of dinonylnaphthalene sulfonic acid.

10. The engine lubricating oil of any one of claims 1 to 7, wherein the corrosion inhibitor is calcium dinonylnaphthalenesulfonate.

11. The engine lubricating oil of any one of claims 1 to 7, wherein the corrosion inhibitor is zinc dinonylnaphthalenesulfonate.

12. The engine lubricating oil of any one of claims 1 to 7, wherein the corrosion inhibitor has at least one organic acid or organic salt of a carboxylate moiety.

13. The engine oil of any of claims 1 to 7, wherein the corrosion inhibitor is an imidazoline reaction product of oleic acid and aminoethyl 2-ethylhexyl amine plus free oleic acid.

14. The engine lubricating oil of any one of claims 1 to 7, wherein the corrosion inhibitor is a 16 carbon chain alkylated succinic anhydride reacted with 1, 3-propanediol.

15. The engine lubricating oil of any one of claims 1 to 7, wherein the corrosion inhibitor has at least one organic salt moiety containing a counterion from the alkali, alkaline earth, transition, metalloid or post-transition metal group.

16. The engine oil of any one of claims 1 to 15, wherein the corrosion inhibitor has at least one organic salt moiety containing calcium, magnesium, lithium, sodium, barium, zinc, or copper counterions.

17. An engine oil lubricant composition comprising:

about 40 wt% to about 90 wt% of at least one base oil;

about 0.1 wt% to about 5 wt% of an organic friction modifier;

from about 0.01% to about 1% by weight of a corrosion inhibitor comprising an organometallic naphthalene compound;

wherein the engine oil lubricant composition has a sulfated ash content of 0.5 wt.% or less and an HTHS (ASTM D4683) of less than or equal to 3.7cP at 150 ℃.

18. The engine lubricating oil of claim 17, wherein the corrosion inhibitor has at least one organic acid or salt of an alkyl or alkylene substituted naphthenate or naphthalene sulfonate moiety.

19. The engine lubricating oil of claim 17, wherein the corrosion inhibitor is selected from the group consisting of zinc naphthenate, barium salts of dinonylnaphthalenesulfonic acid, calcium dinonylnaphthalenesulfonate, zinc dinonylnaphthalenesulfonate.