Engine oil formulations having improved sequence VIII performance

Abstract

A lubricating oil composition comprising greater than 50 weight percent of a base oil of lubricating viscosity, an amount of one or more esters of a polyhydric alcohol, and an amount of one or more boron-containing dispersants, wherein the ratio of the amount of the one or more esters of a polyhydric alcohol in weight percent provided in the lubricating oil composition to the amount of boron in weight percent provided by the one or more boron-containing dispersants is less than 40, based on a total weight of the lubricating oil composition. The lubricating oil composition has improved corrosion performance in engines or other mechanical parts lubricated with the lubricating oil.

Description

[Technical field]

[0001] The present invention relates to engine lubricants having improved Sequence VIII performance. In particular, the disclosure relates to lubricants and methods for improving the corrosion performance of the lubricants in engines or other machine parts lubricated with the lubricants. The lubricants of the disclosure are useful as internal combustion engine oils or in other applications where the lubricants are subjected to heat and corrosive conditions. [Background technology]

[0002] Lubricants are an important part of modern vehicle design for engine operation and protection. Friction modifiers are additives commonly used to reduce friction. They function in part by adhering to the surface of engine hardware. However, a drawback of surface active ingredients is the potential for corrosive action on metal hardware. It has been found that friction modifiers can have a significant effect on corrosion. Friction modifiers often contain combinations of carbon, hydrogen, nitrogen, oxygen, phosphorus, molybdenum, and / or sulfur.

[0003] As the demand for improved fuel economy continues to grow, friction modifiers and other chemicals that reduce friction become more important. Higher concentrations of more active friction modifiers, or similar concentrations of more active friction modifiers, can result in loss of performance characteristics, such as corrosion. Friction modifiers can significantly help improve the fuel economy characteristics of lubricants, but can also result in significant corrosion.

[0004] Thus, a need exists for engine oil additive components and / or combinations that can control copper, lead, and tin bearing corrosion under high temperature operating conditions as compared to conventional additive packages. Summary of the Invention

[0005] 1. In a first aspect, the present disclosure relates to a lubricating oil composition, the lubricating oil composition comprising: greater than 50% by weight of a base oil of lubricating viscosity; an amount of one or more esters of a polyhydric alcohol; and an amount of one or more boron-containing dispersants; a ratio of the amount of one or more esters of polyhydric alcohols provided in the lubricating oil composition in weight percent to the amount of boron provided by the one or more boron-containing dispersants in weight percent is less than 40, based on the total weight of the lubricating oil composition; The lubricating oil composition has a bearing weight loss of less than 25 as measured by ASTM D6709. 2. The lubricating oil composition of paragraph 1, wherein the amount of one or more esters of polyhydric alcohols is less than 0.60 wt.%, or less than 0.40 wt.%, or less than 0.38 wt.%, or about 0.35 wt.% or less, or about 0.01-0.60 wt.%, or about 0.05-0.40 wt.%, based on the total weight of the lubricating oil composition. 3. The lubricating oil composition according to any one of paragraphs 1 to 2, wherein the one or more esters of a polyhydric alcohol can be prepared from a polyhydric alcohol and a carboxylic acid. 4. The lubricating oil composition of any one of paragraphs 1 to 3, wherein one or more esters of a polyhydric alcohol may be prepared from a polyhydric alcohol and a carboxylic acid, the polyhydric alcohol may contain 2 to about 12 carbon atoms, 2 to about 5 carbon atoms, or the polyhydric alcohol may contain 2 to about 8 hydroxyl groups, 2 to about 4 hydroxyl groups, or about 3 hydroxyl groups, or the polyhydric alcohol may be selected from ethylene glycol, propylene glycol, trimethylene glycol, neopentylene glycol, glycerol, glycerine, pentaerythritol, and mixtures thereof, or the polyhydric alcohol may contain alkoxy groups, or ethoxy groups, or propoxy groups. 5. The lubricating oil composition of any one of sentences 1-4, wherein one or more esters of polyhydric alcohols may be prepared from polyhydric alcohols and carboxylic acids, and the carboxylic acids used to prepare the esters of the polyhydric alcohols may include "fatty acids" that may be obtained by hydrolysis of naturally occurring vegetable or animal fats or oils, or the carboxylic acids may contain 8 to 22 carbon atoms, or 16 to 20 carbon atoms, or 16 to 18 carbon atoms, or the carboxylic acids may be caprylic acid, caproic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, etc. 6. The lubricating oil composition according to any one of paragraphs 1 to 5, wherein the one or more esters of a polyhydric alcohol can be a glycerol monooleate compound. 7. The lubricating oil composition according to any one of sentences 1 to 6, wherein the one or more boron-containing dispersants may be present in an amount to provide greater than 0.004 wt.% boron, or greater than 0.006 wt.% boron, or greater than 0.007 wt.% boron, or 0.0077 wt.% or greater than 0.004 wt.% to 0.1 wt.% boron, or greater than 0.006 wt.% to 0.08 wt.% boron, based on the total weight of the lubricating oil composition, or the one or more boron-containing dispersants have 0.1 wt.% to 1.5 wt.% boron, or 0.25 wt.% to 1.25 wt.%, or 0.3 wt.% to 1.1 wt.% boron, based on the total weight of the one or more boron-containing dispersants. 8. The lubricating oil composition of any one of paragraphs 1-7, wherein the one or more boron-containing dispersants can be prepared from a polyisobutenyl group having a number average molecular weight of from about 500 g / mol to about 1800 g / mol, or from about 800 g / mol to about 1600 g / mol, or from about 1000 g / mol to about 1400 g / mol, or about 1300 g / mol, as measured by gel permeation chromatography. 9. The lubricating oil composition according to any one of paragraphs 1 to 8, which may further comprise a second dispersant. 10. The lubricating oil composition of paragraph 9, wherein the second dispersant can be prepared from a polyisobutenyl group having a number average molecular weight of about 1500 g / mol to about 3000 g / mol, or about 1800 g / mol to about 2600 g / mol, or about 2000 g / mol to about 2200 g / mol, or about 2100 g / mol, as measured by gel permeation chromatography. 11. The lubricating oil composition according to any one of paragraphs 9 to 10, wherein the second dispersant may be non-borated. 12. The lubricating oil composition of any one of paragraphs 1-11, wherein the nitrogen concentration from all dispersants can be greater than about 400 ppmw nitrogen, or greater than about 476 ppmw nitrogen, based on the total weight of the lubricating oil composition. 13. The lubricating oil composition of any one of paragraphs 1-12, which may further comprise one or more metal-containing detergents, or one or more calcium-containing detergents present in an amount to provide greater than 950 ppmw Ca, or from about 950 ppmw Ca to about 3000 ppmw Ca, or from about 1000 ppmw Ca to about 2750 ppmw Ca, or from about 1000 ppmw Ca to about 2500 ppmw Ca, based on the total weight of the lubricating oil composition. 14. The lubricating oil composition according to paragraph 13, wherein the one or more calcium-containing detergents can be overbased calcium-containing detergents having a total base number of about 200 mg KOH / g or more, or about 225 mg KOH / g or more, or about 250 mg KOH / gram or more, or about 300 mg KOH / g or more. 15. The lubricating oil composition according to any one of paragraphs 13-14, wherein the one or more calcium-containing detergents may comprise overbased calcium sulfonate detergents, overbased calcium phenate detergents, overbased calcium salicylate detergents, and mixtures thereof. 16. The lubricating oil composition according to any one of paragraphs 13 to 15, wherein the one or more calcium-containing detergents comprise a low-based or neutral calcium-containing detergent having a total base number of less than 175 mg KOH / g. 17. The lubricating oil composition according to any one of paragraphs 13 to 16, wherein the one or more calcium-containing detergents may comprise low-based or neutral calcium-containing detergents, including calcium sulfonate detergents, calcium phenate detergents, calcium salicylate detergents, and mixtures thereof. 18. The lubricating oil composition according to any one of paragraphs 13 to 17, wherein the one or more calcium-containing detergents may comprise low based or neutral calcium-containing detergents, which may be present in an amount from greater than 5 ppmw Ca to about 500 ppmw Ca, or from about 10 ppmw Ca to about 300 ppmw Ca, based on the total weight of the lubricating oil composition. 19. The lubricating oil composition of any one of paragraphs 1 to 18, which may further comprise a zinc dialkyldithiophosphate. 20. The lubricating oil composition of any one of paragraphs 1 to 19, wherein the lubricating oil composition may have a bearing weight loss, as measured by ASTM D6709, of less than 25, or less than 24, or less than 23.4. 21. In a second aspect, the present disclosure relates to a method for improving bearing weight loss of a lubricating oil in an engine, the method comprising adding to the engine the lubricating oil composition of any one of sentences 1-20.

[0006] The following definitions are provided to clarify the meaning of certain terms as used herein.

[0007] The terms "oil composition," "lubrication composition," "lubricating oil composition," "lubricating oil," "lubricant composition," "lubricating composition," "fully formulated lubricant composition," "lubricant," "crankcase oil," "crankcase lubricant," "engine oil," "engine lubricant," "motor oil," and "motor lubricant" are considered to be synonymous and fully interchangeable terms referring to a finished lubricant product comprising a major amount of a base oil plus a minor amount of an additive composition.

[0008] As used herein, the terms "additive package," "additive concentrate," "additive composition," "engine oil additive package," "engine oil additive concentrate," "crankcase additive package," "crankcase additive concentrate," "motor oil additive package," and "motor oil concentrate" are considered to be synonymous and fully interchangeable terms referring to that portion of a lubricating oil composition that excludes a major amount of a base oil stock blend.

[0009] The term "overbased" refers to metal salts, such as metal salts of sulfonates, carboxylates, salicylates, and / or phenates, in which the amount of metal present exceeds the stoichiometric amount. Such salts may have a conversion level of more than 100% (i.e., such salts may contain more than 100% of the theoretical amount of metal required to convert the acid to its "standard salt", "neutral salt"). The expression "metal ratio", often abbreviated as MR, is used to indicate the ratio of the total chemical equivalents of the metal in an overbased salt to the chemical equivalents of the metal in a neutral salt, according to known chemical reactivity and stoichiometry. In standard or neutral salts, the metal ratio (MR) is 1, whereas in overbased salts, the MR is greater than 1. These are generally referred to as overbased, hyperbased, or superbased salts, and may be salts of organic sulfur acids, carboxylic acids, salicylates, and / or phenols.

[0010] As used herein, the term "hydrocarbyl substituent" or "hydrocarbyl group" is used in its normal sense, which is well known to those skilled in the art. Specifically, it refers to a group having a carbon atom directly attached to the remainder of the molecule and having a predominantly hydrocarbon character. Each hydrocarbyl group is independently selected from hydrocarbon substituents, the substituted hydrocarbon substituents containing one or more of halo, hydroxyl, alkoxy, mercapto, nitro, nitroso, amino, pyridyl, furyl, imidazolyl, oxygen, and nitrogen, and no more than two non-hydrocarbon substituents are present for every 10 carbon atoms in the hydrocarbyl group.

[0011] As used herein, the term "hydrocarbylene substituent" or "hydrocarbylene group" is used in its ordinary sense, which is well known to those skilled in the art. Specifically, it refers to a group that is directly attached to the remainder of the molecule by carbon atoms at two locations in the molecule and has a predominantly hydrocarbon character. Each hydrocarbylene group is independently selected from divalent hydrocarbon substituents, where the substituted divalent hydrocarbon substituents include halo, alkyl, aryl, alkylaryl, arylalkyl, hydroxyl, alkoxy, mercapto, nitro, nitroso, amino, pyridyl, furyl, imidazolyl, oxygen, and nitrogen, and no more than two non-hydrocarbon substituents are present for every 10 carbon atoms in the hydrocarbylene group.

[0012] As used herein, the term "weight percent" means the percentage that the recited component represents relative to the weight of the entire composition, unless expressly stated otherwise.

[0013] The terms "soluble", "oil-soluble" or "dispersible" used herein may, but do not necessarily, indicate that a compound or additive is soluble, dissolvable, miscible, or can be suspended in oil in any proportion. However, the terms mean that they are, for example, soluble, suspendable, soluble, or stably dispersible in oil to a sufficient degree to exert their intended effect in the environment in which the oil is used. Furthermore, if desired, the incorporation of other additives may also allow the incorporation of higher levels of a particular additive.

[0014] As used herein, the term "TBN" is used to indicate the total base number in mg KOH / g as measured by the methods of ASTM D2896 or ASTM D4739 or DIN 51639-1.

[0015] The term "alkyl" as used herein refers to straight, branched, cyclic, and / or substituted saturated chain moieties of about 1 to about 100 carbon atoms.

[0016] The term "alkenyl," as used herein, refers to straight, branched, cyclic, and / or substituted unsaturated chain moieties of about 3 to about 10 carbon atoms.

[0017] The term "aryl" as used herein refers to mono- and polycyclic aromatic compounds that may contain alkyl, alkenyl, alkylaryl, amino, hydroxyl, alkoxy, halo substituents, and / or heteroatoms including, but not limited to, nitrogen, oxygen, and sulfur.

[0018] The lubricants, combinations of components, or individual components herein may be suitable for use in various types of internal combustion engines. Suitable engine types may include, but are not limited to, heavy duty diesel, passenger car, light duty diesel, medium speed diesel, or marine engines. The internal combustion engine may be a diesel fueled engine, a gasoline fueled engine, a natural gas fueled engine, a biofuel engine, a mixed diesel / biofuel-fueled engine, a mixed gasoline / biofuel-fueled engine, an alcohol fueled engine, a mixed gasoline / alcohol fueled engine, a compressed natural gas (CNG) fueled engine, or a mixture thereof. The diesel engine may be a compression ignition engine. The gasoline engine may be a spark ignition engine. The internal combustion engine may also be used in combination with electric or battery power sources. Engines so configured are generally known as hybrid engines. The internal combustion engine may be a two-stroke, four-stroke, or rotary engine. Suitable internal combustion engines include marine diesel engines (such as inland marine), aviation piston engines, light duty diesel engines, as well as motorcycle, automobile, locomotive, and truck engines.

[0019] The internal combustion engine may contain one or more components of aluminum alloys, lead, tin, copper, cast iron, magnesium, ceramics, stainless steel, composites, and / or mixtures thereof. The components may be coated, for example, with diamond-like carbon coatings, lubricating coatings, phosphorus-containing coatings, molybdenum-containing coatings, graphite coatings, nanoparticle-containing coatings, and / or mixtures thereof. The aluminum alloy may include aluminum silicate, aluminum oxide, or other ceramic materials. In one embodiment, the aluminum alloy is an aluminum silicate surface. As used herein, the term "aluminum alloy" is synonymous with "aluminum composite" and is intended to describe a component or surface that includes aluminum and another component that mixes or reacts at a microscopic or near-microscopic level, regardless of its detailed structure. This includes conventional alloys with metals other than aluminum, as well as composite or alloy-like structures with non-metallic elements or compounds, such as ceramic-like materials.

[0020] The lubricating oil composition for internal combustion engines may be suitable for any engine lubricant, regardless of sulfur, phosphorus, or sulfated ash (ASTM D-874) content. The sulfur content of the engine oil lubricant may be about 1 wt.% or less, or about 0.8 wt.% or less, or about 0.5 wt.% or less, or about 0.3 wt.% or less, or about 0.2 wt.% or less. In one embodiment, the sulfur content may range from about 0.001 wt.% to about 0.5 wt.%, or about 0.01 wt.% to about 0.3 wt.%. The phosphorus content may be about 0.2 wt.% or less, or about 0.1 wt.% or less, or about 0.085 wt.% or less, or about 0.08 wt.% or less, or even about 0.06 wt.% or less, about 0.055 wt.% or less, or about 0.05 wt.% or less. In one embodiment, the phosphorus content may be about 50 ppm to about 1000 ppm, or about 325 ppm to about 850 ppm. The total sulfated ash content can be about 2% by weight or less, or about 1.5% by weight or less, or about 1.1% by weight or less, or about 1% by weight or less, or about 0.8% by weight or less, or about 0.5% by weight or less. In one embodiment, the sulfated ash content can be about 0.05% by weight to about 0.9% by weight, or 0.1% by weight or about 0.2% by weight to about 0.45% by weight. In another embodiment, the sulfur content can be about 0.4% by weight or less, the phosphorus content can be about 0.08% by weight or less, and the sulfated ash can be about 1% by weight or less. In yet another embodiment, the sulfur content can be about 0.3% by weight or less, the phosphorus content can be about 0.05% by weight or less, and the sulfated ash can be about 0.8% by weight or less.

[0021] In one embodiment, the lubricating oil composition is an engine oil, and the lubricating oil composition may have (i) a sulfur content of less than or equal to about 0.5 wt. %, (ii) a phosphorus content of less than or equal to about 0.1 wt. %, and (iii) a sulfated ash content of less than or equal to about 1.5 wt. %.

[0022] In one embodiment, the lubricating oil composition is suitable for a two-stroke or four-stroke marine diesel internal combustion engine. In one embodiment, the marine diesel combustion engine is a two-stroke engine. In some embodiments, the lubricating oil composition is not suitable for a two-stroke or four-stroke marine diesel internal combustion engine for one or more reasons, including, but not limited to, the high sulfur content of the fuel used to power the marine engine and the high TBN required for engine oils suitable for marine use (e.g., greater than about 40 TBN for engine oils suitable for marine use).

[0023] In some embodiments, the lubricating oil compositions are suitable for use with engines powered by low sulfur fuels, such as fuels containing about 1 to about 5% sulfur. Highway vehicle fuels contain about 15 ppm sulfur (or about 0.0015% sulfur).

[0024] Low speed diesel typically refers to marine engines, medium speed diesel typically refers to locomotives, and high speed diesel typically refers to highway vehicles. A lubricating oil composition may be suitable for only one or all of these types.

[0025] Additionally, the lubricants herein may meet one or more industry specification requirements, such as ILSAC GF-3, GF-4, GF-5, GF-5+, GF-6, PC-11, CF, CF-4, CH-4, CK-4, FA-4, CJ-4, CI-4 Plus, CI-4, API SG, SJ, SL, SM, SN, SN PLUS, ACEA A1 / B1, A2 / B2, A3 / B3, A3 / B4, A5 / B5, A7 / B7, C1, C2, C3, C4, C5, C6E4 / E6 / E7 / E9, Euro5 / 6, JASO DL-1, Low SAPS, Mid SAPS, or Dexos1™, Dexos2™, MB-Approval™, Dexos3™, Dexos4™, Dexos5™, Dexos6™, Dexos7™, Dexos8™, Dexos9™, Dexos11™, Dexos12™, Dexos13™, Dexos14™, Dexos15™, Dexos16™, Dexos17™, Dexos18™, Dexos19™, Dexos21™, Dexos22™, Dexos23™, Dexos24™, Dexos25™, Dexos26™, Dexos27™, Dexos28™, Dexos29 ... 229.1, 229.3, 229.5, 22.51 / 229.31, 229.52, 229.6, 229.71, 226.5, 226.51, 228.0 / .1, 228.2 / .3, 228.31, 228.5, 228.51, 228.61, VW 501.01,502.00,503.00 / 503.01,504.00,505.00,505.01,506.00 / 506.01,507.00,508.00,509.00,508.88,509.99,BMW Longlife-01, Longlife-01FE, Longlife-04, Longlife-12FE, Longlife-14FE+, Longlife-17FE+Porsche A40, C30, Peugeot Citroen Automobiles B71 2290, B71 2294, B71 2295, B71 2296, B71 2297, B71 2300, B71 2302, B71 2312, B71 2007, B71 2008, Renault RN0700, RN0710, RN0720, Ford WSS-M2C153-H, WSS-M2C930-A, WSS-M2C945-A, WSS-M2C913A, WSS-M2C913-B, WSS-M2C913-C, WSS-M2C913-D, WSS-M2C948-B, WSS-M2C948-A, GM 6094-M, Chrysler MS-6395, Fiat 9.55535 G1, G2, M2, N1, N2, Z2, S1, S2, S3, S4, T2, DS1, DSX, GH2, GS1, GSX, CR1, Jaguar Land Rover STJLR.03.5003, STJLR.03.The compositions may be suitable to meet original equipment manufacturer specifications such as STJLR.03.5004, STJLR.03.5005, STJLR.03.5006, STJLR.03.5007, STJLR.51.5122, or past or future PCMO or HDD specifications not mentioned herein. In some embodiments for passenger car motor oil (PCMO) applications, the amount of phosphorus in the final fluid is 1000 ppm or less, or 900 ppm or less, or 800 ppm or less.

[0026] Other hardware may not be suitable for use with the disclosed lubricants. "Functional fluid" is a term that encompasses a variety of fluids, including, but not limited to, tractor hydraulic fluids, power transmission fluids including automatic transmission fluids, continuously variable transmission fluids and manual transmission fluids, hydraulic fluids including tractor hydraulic fluids, some gear oils, power steering fluids, wind turbines, fluids used in compressors, some industrial fluids, and fluids associated with power transmission components. It should be noted that within each of these fluids, such as automatic transmission fluids, there are a variety of different types of fluids for different transmissions with different designs that require fluids with significantly different functional properties. This is in contrast to the term "lubricating fluids" that are not used to generate or transmit power.

[0027] For example, with respect to tractor hydraulic fluids, these fluids are general purpose products used for all lubrication applications in the tractor except for lubricating the engine, which may include lubricating the gearbox, power take-offs and clutches, rear axles, reduction gears, wet brakes, and hydraulic accessories.

[0028] When the functional fluid is an automatic transmission fluid, the automatic transmission fluid must have enough friction for the clutch plates to transmit power. However, the coefficient of friction of the fluid tends to decrease due to the effects of temperature as the fluid heats up during operation. It is important that the tractor working fluid or automatic transmission fluid maintain a high coefficient of friction at high temperatures or else the brake system or automatic transmission may fail. This is not the function of engine oil.

[0029] Tractor fluids, such as Super Tractor Universal Oil (STUO) or Universal Tractor Transmission Oil (UTTO), may combine engine oil performance with transmission, differential, final drive planetary gear, wet brake, and hydraulic performance. Many of the additives used to formulate UTTO or STUO fluids are functionally similar, but they can have detrimental effects if not properly incorporated. For example, some anti-wear and extreme pressure additives used in engine oils can be highly corrosive to copper components in hydraulic pumps. Detergents and dispersants used in gasoline or diesel engine performance can be detrimental to wet brake performance. Friction modifiers specific to quiet wet brake squeal may lack the thermal stability required for engine oil performance. Each of these fluids is designed to meet specific and stringent manufacturer requirements, whether functional, tractor, or lubricity.

[0030] The present disclosure provides novel lubricating oil blends formulated for use as automotive crankcase lubricants. The present disclosure provides novel lubricating oil blends formulated for use as 2T and / or 4T motorcycle crankcase lubricants. Embodiments of the present disclosure may provide lubricating oils suitable for crankcase applications and having improvements in air entrainment, alcohol fuel compatibility, antioxidant properties, antiwear performance, biofuel compatibility, foam reduction properties, friction reduction, fuel economy, pre-ignition prevention, rust prevention, sludge and / or soot dispersancy, piston cleanliness, deposit formation, and water resistance properties.

[0031] The engine oils of the present disclosure may be formulated by adding one or more additives to a suitable base oil formulation, as described in detail below. The additives may be combined with the base oil in the form of an additive package (or concentrate), or alternatively, may be combined individually with the base oil (or a mixture of both). The fully formulated engine oil may exhibit improved performance characteristics based on the additives added and their respective proportions.

[0032] Further details and advantages of the present disclosure will be set forth in part in the description which follows and / or may be learned by the practice of the present disclosure. The details and advantages of the present disclosure may be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure as claimed. [Brief description of the drawings]

[0033] [Figure 1] 1 shows a chart comparing the ratio of weight percent of glycerol monooleate to weight percent of boron contributed by one or more boron-containing dispersants versus bearing weight loss for the oils of Table 4. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0034] The present disclosure relates to lubricating oil compositions having improved bearing weight loss. In particular, the present disclosure relates to lubricating oil compositions and methods for improving the bearing weight loss of lubricants in engines or other machine parts lubricated with the lubricating oil. The lubricating oils of the present disclosure are useful as passenger vehicle engine oil (PVEO) products, commercial vehicle engine oil (CVEO) products, or other applications in which the lubricating oil is subjected to thermal and corrosive conditions.

[0035] The lubricating oil composition of the present invention comprises greater than 50 weight percent of a base oil of lubricating viscosity, an amount of one or more esters of polyhydric alcohols, and an amount of one or more boron-containing dispersants, wherein the ratio of the amount of the one or more esters of polyhydric alcohols in weight percent provided in the lubricating oil composition to the amount of boron in weight percent provided by the one or more boron-containing dispersants, based on a total weight of the lubricating oil composition, is less than 40, and the lubricating oil composition has a bearing weight loss of less than 25 as measured by ASTM D6709.

[0036] Base Oil The base oil used in the lubricating oil compositions herein may be selected from any of the base oils in Groups I to V as specified in the American Petroleum Institute (API) Base Oil Interchangeability Guidelines. The five base oil groups are as follows:

[0037] [Table 1]

[0038] Group I, Group II, and Group III are mineral oil process feedstocks. Group IV base oils contain true synthetic molecular species produced by polymerization of olefinically unsaturated hydrocarbons. Many Group V base oils are also true synthetic products and may include diesters, polyol esters, polyalkylene glycols, alkylated aromatics, polyphosphate esters, polyvinyl ethers, and / or polyphenyl ethers, etc., but may be natural oils such as vegetable oils. It should be noted that Group III base oils are derived from mineral oils, but the rigorous processing these fluids undergo makes their physical properties very similar to some true synthetic oils such as PAOs. Thus, oils derived from Group III base oils may be referred to as synthetic fluids in the industry. Group II+ may include high viscosity index Group II.

[0039] The base oil used in the disclosed lubricating oil compositions can be mineral oils, animal oils, vegetable oils, synthetic oils, synthetic oil blends, or mixtures thereof. Suitable oils can be derived from hydrocracked, hydrogenated, hydrofinished, unrefined, refined, and rerefined oils, and mixtures thereof.

[0040] Unrefined oils are derived from natural, mineral, or synthetic sources with little or no further refinement processing. Refined oils are similar to unrefined oils, except that they have been treated with one or more refining steps, which may result in the improvement of one or more properties. Examples of suitable refining techniques are solvent extraction, secondary distillation, acid or base extraction, filtration, percolation, etc. Oils refined to edible quality may or may not be useful. Edible oils may also be called white oils. In some embodiments, the lubricating oil composition does not include edible oils or white oils.

[0041] Rerefined oils are also known as reclaimed or reprocessed oils. These oils are obtained similarly to refined oils using the same or similar processes. Often these oils are further processed by techniques directed to the removal of spent additives and oil breakdown products.

[0042] Mineral oils may include oils obtained by drilling or from plants and animals, or any mixture thereof. For example, such oils may include, but are not limited to, castor oil, lard oil, olive oil, peanut oil, corn oil, soybean oil, and linseed oil, as well as mineral lubricating oils, such as liquid petroleum oils, and solvent- or acid-treated mineral lubricating oils of the paraffinic, naphthenic, or mixed paraffinic-naphthenic types. Such oils may be partially or fully hydrogenated, if desired. Oils derived from coal or shale may also be useful.

[0043] Useful synthetic lubricating oils may include hydrocarbon oils such as polymerized, oligomerized, or interpolymerized olefins (e.g., polybutylene, polypropylene, propylene isobutylene copolymers); poly(1-hexene), poly(1-octene), trimers or oligomers of 1-decene, such as poly(1-decene) (such materials are often referred to as alpha-olefins), and mixtures thereof; alkyl-benzenes (e.g., dodecylbenzene, tetradecylbenzene, dinonylbenzene, di-(2-ethylhexyl)-benzene); polyphenyls (e.g., biphenyl, terphenyl, alkylated polyphenyls); diphenylalkanes, alkylated diphenylalkanes, alkylated diphenyl ethers, and alkylated diphenyl sulfides, and derivatives, analogs, and homologs thereof, or mixtures thereof. The polyalphaolefins are typically hydrogenated materials.

[0044] Other synthetic lubricating oils include polyol esters, diesters, liquid esters of phosphorus-containing acids (e.g., tricresyl phosphate, trioctyl phosphate, and diethyl ester of decane phosphonic acid), or polymeric tetrahydrofurans. Synthetic oils may be produced by the Fischer-Tropsch reaction and typically may be hydroisomerized Fischer-Tropsch hydrocarbons or waxes. In one embodiment, the oils may be prepared by the Fischer-Tropsch gas-liquid synthesis procedure, as well as other gas-liquid oils.

[0045] A major amount of base oil included in the lubricating composition may be selected from the group consisting of Group I, Group II, Group III, Group IV, Group V, and combinations of two or more of the foregoing, but the major amount of base oil is other than the base oil resulting from the provision of an additive component or viscosity index improver in the composition. In another embodiment, a major amount of base oil included in the lubricating composition may be selected from the group consisting of Group II, Group III, Group IV, Group V, and combinations of two or more of the foregoing, but the major amount of base oil is other than the base oil resulting from the provision of an additive component or viscosity index improver in the composition.

[0046] The amount of oil of lubricating viscosity present may be the remaining amount remaining after subtracting the sum of the amounts of performance additives, including viscosity index improvers and / or pour point depressants and / or other top treatment additives, from 100% by weight. For example, the oil of lubricating viscosity may be present in the final fluid in a major amount, such as greater than about 50% by weight, greater than about 60% by weight, greater than about 70% by weight, greater than about 80% by weight, greater than about 85% by weight, or greater than about 90% by weight.

[0047] Esters of polyhydric alcohols The lubricating oil composition may include an amount of one or more esters of a polyhydric alcohol. The one or more esters of a polyhydric alcohol may be partial fatty acid esters of a polyhydric alcohol containing at least one hydroxyl group in the alcohol portion of the ester, i.e., not all of the hydroxyl groups of the polyhydric alcohol are converted to ester groups. The esters of a polyhydric alcohol may be prepared by esterifying a polyhydric alcohol with one or more carboxylic acids.

[0048] Suitable examples of carboxylic acids used to prepare one or more esters of polyhydric alcohols include "fatty acids". The term "fatty acids" refers to acids that can be obtained by hydrolysis of naturally occurring vegetable or animal fats or oils. These acids usually contain 8 to 22 carbon atoms and include, for example, caprylic acid, caproic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, etc. Acids containing 16 to 20 carbon atoms are preferred, and acids containing 16 to 18 carbon atoms are particularly preferred.

[0049] Suitable examples of polyhydric alcohols used to prepare one or more esters of polyhydric alcohols may contain from 2 to about 12 carbon atoms, preferably from 2 to about 5 carbon atoms, and from 2 to about 8 hydroxyl groups, preferably from 2 to about 4 hydroxyl groups, and most preferably about 3 hydroxyl groups. For example, the polyhydric alcohol may be selected from ethylene glycol, propylene glycol, trimethylene glycol, neopentylene glycol, glycerol, glycerin, pentaerythritol, and mixtures thereof. In some embodiments, the polyhydric alcohol may contain an alkoxy group, preferably an ethoxy group or a propoxy group.

[0050] For example, the one or more esters of polyhydric alcohols may be organic ashless nitrogen-free friction modifiers, also known as glycerol monooleate compounds (or glyceryl monooleate). In this specification, the one or more glycerol monooleate compounds are selected from 9-octadecenoic acid; and mono-, di-, and tri-esters of oleic acid, such as glyceryl monooleate, glyceryl oleate, glycerol oleate, GMO, and monoolein. Preferably, the one or more esters of polyhydric alcohols are glycerol monooleate compounds (or glyceryl monooleate).

[0051] The one or more esters of polyhydric alcohols may be present in an amount of less than 0.60 wt%, or less than 0.40 wt%, or less than 0.38 wt%, or about 0.35 wt% or less, or about 0.01-0.60 wt%, or about 0.05-0.40 wt%, based on the total weight of the lubricating oil composition. A commonly used ester of polyhydric alcohol used as a friction modifier in engine oil compositions is glycerol monooleate.

[0052] The lubricating oil composition has a ratio of the amount of one or more esters of polyhydric alcohols, in weight percent, provided in the lubricating oil composition to the amount of boron, in weight percent, provided by the one or more boron-containing dispersants, of less than 40, based on the total weight of the lubricating oil composition.

[0053] Dispersants The lubricating oil composition includes one or more dispersants. Dispersants are often known as ashless dispersants because they do not contain ash-forming metals prior to mixing with the lubricating oil composition and do not normally contribute to ash when added to the lubricant. Ashless dispersants are characterized by having polar groups attached to a relatively high molecular weight hydrocarbon chain. Typical ashless dispersants include N-substituted long chain alkenyl succinimides. Examples of N-substituted long chain alkenyl succinimides include polyisobutylene succinimides in which the number average molecular weight of the polyisobutylene substituent ranges from about 350 to about 50,000, or up to about 5,000, or up to about 3,000, as measured by GPC. Succinimide dispersants and their preparation are disclosed, for example, in U.S. Pat. No. 7,897,696 or U.S. Pat. No. 4,234,435. The alkenyl substituent may be prepared from a polymerizable monomer containing from about 2 to about 16, or from about 2 to about 8, or from about 2 to about 6 carbon atoms. Succinimide dispersants are typically imides formed from polyamines, typically poly(ethyleneamines).

[0054] Preferred amines are selected from polyamines and hydroxyamines. Examples of polyamines that may be used include, but are not limited to, diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA), and higher homologs such as pentaethylaminehexamine (PEHA).

[0055] Suitable heavy polyamines are mixtures of polyalkylene-polyamines containing small amounts of lower polyamine oligomers such as TEPA and PEHA (pentaethylenehexamine), but primarily oligomers with 6 or more nitrogen atoms, 2 or more primary amines per molecule, and more extensive branching than conventional polyamine mixtures. Heavy polyamines preferably include polyamine oligomers containing 7 or more nitrogen atoms per molecule and having 2 or more primary amines per molecule. Heavy polyamines contain greater than 28% by weight (e.g., greater than 32% by weight) total nitrogen and an equivalent weight of 120 to 160 grams of primary amine groups per equivalent.

[0056] In some approaches, suitable polyamines, commonly known as PAM, contain a mixture of ethyleneamines, with TEPA and pentaethylenehexamine (PEHA) being the major portion of the polyamine, usually less than about 80%.

[0057] Typically, the PAM has 8.7 to 8.9 milliequivalents of primary amine per gram (115 to 112 equivalents per equivalent of primary amine) and a total nitrogen content of about 33% to 34% by weight. Heavier cuts of the PAM oligomers, substantially free of TEPA and containing only small amounts of PEHA, but containing primarily oligomers with more than 6 nitrogens and more extensive branching, may produce dispersants with improved dispersancy.

[0058] In some embodiments, the present disclosure further comprises at least one polyisobutylene succinimide dispersant derived from a polyisobutylene having a number average molecular weight in the range of about 350 to about 50,000, or to about 5,000, or to about 3,000, as determined by GPC. The polyisobutylene succinimide may be used alone or in combination with other dispersants.

[0059] In some embodiments, when polyisobutylene is included, the polyisobutylene may have a terminal double bond content of greater than 50 mol%, greater than 60 mol%, greater than 70 mol%, greater than 80 mol%, or greater than 90 mol%. Such PIB is also referred to as highly reactive PIB ("HR-PIB"). HR-PIB having a number average molecular weight in the range of about 800 to about 5000 as determined by GPC is suitable for use in embodiments of the present disclosure. Conventional PIB typically has a terminal double bond content of less than 50 mol%, less than 40 mol%, less than 30 mol%, less than 20 mol%, or less than 10 mol%.

[0060] HR-PIB having a number average molecular weight ranging from about 900 to about 3000 as measured by GPC may be suitable. Such HR-PIB is commercially available or can be synthesized by polymerization of isobutene in the presence of a non-chlorinated catalyst such as boron trifluoride, as described in U.S. Patent No. 4,152,499 to Boerzel, et al. and U.S. Patent No. 5,739,355 to Gateau, et al. When HR-PIB is used in the thermal ene reaction, it may result in higher conversion during the reaction and less precipitate formation due to increased reactivity. A suitable method is described in U.S. Patent No. 7,897,696.

[0061] In one embodiment, the present disclosure further comprises at least one dispersant derived from polyisobutylene succinic anhydride ("PIBSA"), which may have an average of about 1.0 to about 2.0 succinic moieties per polymer.

[0062] The percent actives of the alkenyl or alkyl succinic anhydride can be determined using chromatographic techniques, which are explained in columns 5 and 6 of U.S. Patent No. 5,334,321.

[0063] Polyolefin conversion is calculated from the percent actives using the formula in columns 5 and 6 of US Pat. No. 5,334,321.

[0064] Unless otherwise specified, all percentages are weight percent and all molecular weights are number average molecular weights as determined by gel permeation chromatography (GPC) using commercially available polystyrene standards (having number average molecular weights of 180 to about 18,000) as calibration standards.

[0065] In one embodiment, the dispersant may be derived from a polyalphaolefin (PAO) succinic anhydride. In one embodiment, the dispersant may be derived from an olefin maleic anhydride copolymer. As an example, the dispersant may be described as poly-PIBSA. In one embodiment, the dispersant may be derived from an anhydride grafted to an ethylene-propylene copolymer.

[0066] One class of suitable dispersants can be Mannich bases. Mannich bases are materials formed by the condensation of higher molecular weight alkyl-substituted phenols, polyalkylene polyamines, and aldehydes such as formaldehyde. Mannich bases are described in more detail in U.S. Pat. No. 3,634,515.

[0067] A suitable class of dispersants may also be high molecular weight esters or half ester amides.

[0068] Suitable dispersants may also be post-treated by conventional methods by reaction with any of a variety of agents. Among these are boron, urea, thiourea, dimercaptothiadiazoles, carbon disulfide, aldehydes, ketones, carboxylic acids, hydrocarbon-substituted succinic anhydrides, maleic anhydrides, nitriles, epoxides, carbonates, cyclic carbonates, hindered phenol esters, and phosphorus compounds. U.S. Patent No. 7,645,726, U.S. Patent No. 7,214,649, and U.S. Patent No. 8,048,831 are incorporated herein by reference in their entireties.

[0069] In addition to the carbonate and boric acid post-treatments, any of the compounds may be post-treated or further post-treated with a variety of post-treatments designed to improve or impart different properties. Such post-treatments include those summarized in columns 27-29 of U.S. Patent No. 5,241,003, which is incorporated herein by reference. Such treatments include treatment with: Inorganic phosphoric acids or anhydrides (e.g., U.S. Pat. Nos. 3,403,102 and 4,648,980); Organophosphorus compounds (e.g., U.S. Pat. No. 3,502,677); Phosphorus pentasulfide; The boron compounds already mentioned above (e.g., U.S. Pat. Nos. 3,178,663 and 4,652,387); Carboxylic acids, polycarboxylic acids, anhydrides, and / or acid halides (e.g., U.S. Pat. Nos. 3,708,522 and 4,948,386); epoxides, polyepoxiates, or thioepoxides (e.g., U.S. Pat. Nos. 3,859,318 and 5,026,495); Aldehydes or ketones (e.g., U.S. Pat. No. 3,458,530); Carbon disulfide (e.g., U.S. Pat. No. 3,256,185); glycidol (e.g., U.S. Pat. No. 4,617,137); urea, thiourea or guanidine (e.g., U.S. Pat. Nos. 3,312,619, 3,865,813, and British Pat. No. 1,065,595); organic sulfonic acids (e.g., U.S. Pat. No. 3,189,544 and British Pat. No. 2,140,811); Alkenyl cyanides (e.g., U.S. Pat. Nos. 3,278,550 and 3,366,569); Diketene (e.g., U.S. Pat. No. 3,546,243); diisocyanates (e.g., U.S. Pat. No. 3,573,205); Alkanesultones (e.g., U.S. Pat. No. 3,749,695); 1,3-dicarbonyl compounds (e.g., U.S. Pat. No. 4,579,675); Sulfates of alkoxylated alcohols or phenols (e.g., U.S. Pat. No. 3,954,639); Cyclic lactones (e.g., U.S. Pat. Nos. 4,617,138, 4,645,515, 4,668,246, 4,963,275, and 4,971,711); cyclic carbonates or thiocarbonates, linear monocarbonates or polycarbonates, or chloroformates (e.g., U.S. Pat. Nos. 4,612,132, 4,647,390, 4,648,886, 4,670,170); Nitrogen-containing carboxylic acids (e.g., U.S. Pat. No. 4,971,598 and British Pat. No. 2,140,811); Hydroxy-protected chlorodicarbonyloxy compounds (e.g., U.S. Pat. No. 4,614,522); lactams, thiolactams, thiolactones, or ditholactones (e.g., U.S. Pat. Nos. 4,614,603 and 4,666,460); cyclic carbonates or thiocarbonates, linear monocarbonates or polycarbonates, or chloroformates (e.g., U.S. Pat. Nos. 4,612,132, 4,647,390, 4,646,860, and 4,670,170); Nitrogen-containing carboxylic acids (e.g., U.S. Pat. No. 4,971,598 and British Pat. No. 2,440,811); Hydroxy-protected chlorodicarbonyloxy compounds (e.g., U.S. Pat. No. 4,614,522); Lactams, thiolactams, thiolactones, or dithiolactones (e.g., U.S. Pat. Nos. 4,614,603 and 4,666,460); Cyclic carbamates, cyclic thiocarbamates, or cyclic dithiocarbamates (e.g., U.S. Pat. Nos. 4,663,062 and 4,666,459); Hydroxyaliphatic carboxylic acids (e.g., U.S. Pat. Nos. 4,482,464, 4,521,318, and 4,713,189); oxidizing agents (e.g., U.S. Pat. No. 4,379,064); Combinations of phosphorus pentasulfide and polyalkylenepolyamines (e.g., U.S. Pat. No. 3,185,647); Combinations of carboxylic acids or aldehydes or ketones and sulfur or sulfur chlorides (e.g., U.S. Pat. Nos. 3,390,086 and 3,470,098); A combination of hydrazine and carbon disulfide (e.g., U.S. Pat. No. 3,519,564); Combinations of aldehydes and phenols (e.g., U.S. Pat. Nos. 3,649,229, 5,030,249, and 5,039,307); Combinations of aldehydes and O-diesters of dithiophosphoric acids (e.g., U.S. Pat. No. 3,865,740); Combinations of hydroxyaliphatic carboxylic acids and boric acid (e.g., U.S. Pat. No. 4,554,086); A combination of hydroxyaliphatic carboxylic acids followed by formaldehyde and phenol (e.g., U.S. Pat. No. 4,636,322); Combinations of hydroxyaliphatic carboxylic acids followed by aliphatic dicarboxylic acids (e.g., U.S. Pat. No. 4,663,064); A combination of formaldehyde and phenol followed by glycolic acid (e.g., U.S. Pat. No. 4,699,724); A combination of a hydroxyaliphatic carboxylic acid or oxalic acid followed by a diisocyanate (e.g., U.S. Pat. No. 4,713,191); Combinations of inorganic acids or anhydrides of phosphorus or their partial or total sulfur analogs and boron compounds (e.g., U.S. Pat. No. 4,857,214); A combination of an organic diacid, followed by an unsaturated fatty acid, and then a nitrosoaromatic amine, optionally followed by a boron compound, and then a glycosylation agent (e.g., U.S. Pat. No. 4,973,412); Combinations of aldehydes and triazoles (e.g., U.S. Pat. No. 4,963,278); A combination of an aldehyde and a triazole followed by a boron compound (e.g., U.S. Pat. No. 4,981,492); Combinations of cyclic lactones and boron compounds (e.g., U.S. Pat. Nos. 4,963,275 and 4,971,711), which are incorporated herein by reference in their entireties.

[0070] Suitable dispersants may have a TBN of about 10 to about 65 without oil, which is equivalent to a TBN of about 5 to about 30 when measured on a dispersant sample containing about 50% diluent oil. TBN is measured by the method of ASTM D2896.

[0071] Dispersants, when present, may be used in an amount sufficient to provide up to about 20% by weight, based on the final weight of the lubricating oil composition. Alternative amounts of dispersant that may be used may be from about 0.1% to about 15% by weight, or from about 0.1% to about 10% by weight, or from about 0.1% to about 8% by weight, or from about 1% to about 10% by weight, or from about 1% to about 8% by weight, or from about 1% to about 6% by weight, based on the final weight of the lubricating oil composition. In some embodiments, the lubricating oil composition utilizes a mixed dispersant system. A single type or a mixture of two or more types of dispersants in any desired ratio may be used.

[0072] The lubricating oil composition may comprise a concentration of total dispersant of greater than 0.1 wt.%, or greater than about 0.25 wt.%, or less than about 20 wt.%, or less than about 15.0 wt.%, from about 0.1 wt.% to about 15.0 wt.%, or from about 0.15 wt.% to about 10 wt.%, based on the total weight of the lubricating oil composition.

[0073] The lubricating oil composition may have a nitrogen concentration from total dispersants of greater than 200 ppmw nitrogen, or greater than 400 ppmw nitrogen, or greater than 476 ppmw nitrogen, or from about 200 ppmw to about 1200 ppmw nitrogen, or from about 400 ppmw nitrogen to about 1000 ppmw nitrogen, based on the total weight of the lubricating oil composition.

[0074] Boron-containing dispersants The lubricating oil composition may include one or more boron-containing or borated dispersants. The dispersants described in the previous section as being borated may be used, and the dispersants described in the previous section as being non-borated may be used after being borated.

[0075] The boron-containing dispersant may be prepared from a polyisobutylene group having a number average molecular weight of about 500 g / mol to about 1800 g / mol, or about 800 g / mol to about 1600 g / mol, or about 1000 g / mol to about 1400 g / mol, or about 1300 g / mol, as measured by gel permeation chromatography. The boron-containing dispersant may be prepared from succinic acid or anhydride.

[0076] The lubricating oil composition may contain one or more boron-containing dispersants in an amount of greater than 0.1 wt%, or greater than about 0.25 wt%, or greater than 0.50 wt%, or greater than 0.75 wt%, or less than about 20 wt%, or less than about 10.0 wt%, from about 0.1 wt% to about 15.0 wt%, or from about 0.15 wt% to about 10 wt%, or from about 0.25 wt% to about 7.5 wt%, or greater than about 0.5 wt% to about 7.5 wt%, or 0.75 wt% to about 7.5 wt%, based on the total weight of the lubricating oil composition.

[0077] The one or more boron-containing dispersants may be present in an amount to provide greater than 0.004 wt.% boron, or greater than 0.006 wt.% boron, or greater than 0.007 wt.% boron, or 0.0077 wt.% or more boron, or greater than 0.004 wt.% to 0.1 wt.% boron, or greater than 0.006 wt.% to 0.08 wt.% boron, based on the total weight of the lubricating oil composition, or the one or more boron-containing dispersants have 0.1 wt.% to 1.5 wt.% boron, or 0.25 wt.% to 1.25 wt.%, or 0.3 wt.% to 1.1 wt.% boron, based on the total weight of the one or more boron-containing dispersants.

[0078] Additional Dispersant The lubricating oil composition may optionally contain an additional non-borated dispersant. A single type or a mixture of two or more types of dispersants in any desired ratio may be used. The lubricating oil composition may contain one or more dispersants, or two or more dispersants, in addition to the boron-containing dispersant. Preferably, the lubricating oil composition contains an additional dispersant, also referred to as a second dispersant, which may not be borated. The dispersants described in the previous section as not borated may be used. The additional dispersant may be prepared from a polyisobutenyl group having a number average molecular weight of about 1500 g / mol to about 3000 g / mol, or about 1800 g / mol to about 2600 g / mol, or about 2000 g / mol to about 2200 g / mol, or about 2100 g / mol, as measured by gel permeation chromatography.

[0079] The lubricating oil composition may contain one or more additional dispersants in an amount of greater than 0.1 wt.%, or greater than about 0.25 wt.%, or less than about 15 wt.%, or less than about 10.0 wt.%, from about 0.1 wt.% to about 15.0 wt.%, or from about 0.15 wt.% to about 10 wt.%, or from about 0.25 wt.% to about 5.0 wt.%, based on the total weight of the lubricating oil composition.

[0080] Detergent The lubricating oil composition may include one or more detergents. The one or more detergents may be neutral, low based, or overbased detergents, and mixtures thereof. Suitable detergent substrates include phenates, sulfur-containing phenates, sulfonates, calixarates, salixarates, salicylates, carboxylic acids, phosphoric acids, mono- and / or di-thiophosphoric acids, alkylphenols, sulfur-linked alkylphenol compounds, or methylene bridged phenols. Suitable detergents and their preparation methods are described in more detail in numerous patent publications, including U.S. Pat. No. 7,732,390 and references cited therein.

[0081] One or more detergents may be formed from a detergent matrix salified with an alkali metal or another alkaline earth metal, such as, but not limited to, calcium, magnesium, potassium, sodium, lithium, barium, or mixtures thereof, hi some embodiments, the detergent does not include barium.

[0082] Suitable detergents may include salts of petroleum sulfonic acids and long chain mono- or di-alkylaryl sulfonic acids in which the aryl groups are benzyl, tolyl, and xylyl. Examples of suitable detergents include, but are not limited to, calcium phenate, sulfur-containing calcium phenate, calcium sulfonate, calcium calixarate, calcium salixarate, calcium salicylate, calcium carboxylate, calcium phosphate, calcium mono- and / or di-thiophosphate, calcium alkylphenol, calcium sulfur-bound alkylphenol compound, calcium methylene bridged phenol, magnesium phenate, sulfur-containing magnesium phenate, magnesium sulfonate, magnesium calixarate, magnesium salixarate, magnesium salicylate, magnesium carboxylate, magnesium phosphate, magnesium mono- and / or di-thiophosphate, magnesium alkylphenol, magnesium sulfur-bound alkylphenol compound, magnesium methylene bridged phenol, sodium phenate, sulfur-containing sodium phenate, sodium sulfonate, sodium calixarate, sodium salixarate, sodium salicylate, sodium carboxylate, sodium phosphate, sodium mono- and / or di-thiophosphate, sodium alkylphenol, sodium sulfur-bound alkylphenol compound, or sodium methylene bridged phenol.

[0083] One or more of the detergents may be overbased detergents. Such detergent additives may be prepared by reacting a metal oxide or metal hydroxide with a substrate and carbon dioxide gas. The substrate is typically an acid, such as an aliphatic-substituted sulfonic acid, an aliphatic-substituted carboxylic acid, or an aliphatic-substituted phenol.

[0084] The term "overbased" refers to metal salts, such as metal salts of sulfonates, carboxylates, and phenates, in which the amount of metal present exceeds the stoichiometric amount. Such salts may have a conversion level of more than 100% (i.e., such salts may contain more than 100% of the theoretical amount of metal required to convert the acid to its "standard" or "neutral" salt). The expression "metal ratio", often abbreviated as MR, is used to indicate the ratio of the total chemical equivalents of the metal in an overbased salt to the chemical equivalents of the metal in a neutral salt, according to known chemical reactivity and stoichiometry. In standard or neutral salts, the metal ratio (MR) is 1, whereas in overbased salts, the MR is greater than 1. They are generally referred to as overbased, hyperbased, or superbased salts, and may be salts of organic sulfur acids, carboxylic acids, or phenols.

[0085] The overbased detergent of the lubricating oil composition may have a total base number (TBN) of about 200 mg KOH / gram or greater, or, as a further example, about 225 mg KOH / gram or greater, or about 250 mg KOH / gram or greater, or about 300 mg KOH / gram or greater, or about 350 mg KOH / gram or greater, or about 375 mg KOH / gram or greater, or about 400 mg KOH / gram or greater.

[0086] Preferably, the one or more detergents comprise an overbased calcium-containing detergent.Suitable examples of overbased calcium-containing detergents include but are not limited to overbased calcium phenate, overbased sulfur-containing calcium phenate, overbased calcium sulfonate, overbased calcium calixarate, overbased calcium salixarate, overbased calcium salicylate, overbased calcium carboxylate, overbased calcium phosphate, overbased calcium monothiophosphate and / or dithiophosphate, overbased calcium alkylphenol, overbased calcium sulfur-bonded alkylphenol compound, and overbased calcium methylene-bridged phenol.Preferably, the overbased calcium-containing detergent is an overbased calcium sulfonate detergent.

[0087] Examples of other suitable overbased detergents include, but are not limited to, overbased magnesium phenol, overbased sulfur-containing magnesium phenol, overbased magnesium sulfonate, overbased magnesium calixarate, overbased magnesium salixarate, overbased magnesium salicylate, overbased magnesium carboxylate, overbased magnesium phosphate, overbased magnesium mono- and / or di-thiophosphate, overbased magnesium alkylphenol, overbased magnesium sulfur-linked alkylphenol compound, or overbased magnesium methylene bridged phenol.

[0088] Overbased detergents may have a metal to substrate ratio of 1.1:1 or greater, or 2:1 or greater, or 4:1 or greater, or 5:1 or greater, or 7:1 or greater, or 10:1 or greater.

[0089] The one or more detergents may be low-based / neutral detergents having a TBN of up to 175 mg KOH / g, or up to 150 mg KOH / g. The low-based / neutral detergents may be formed from detergent substrates salified with an alkali metal or another alkaline earth metal, such as, but not limited to, calcium, magnesium, potassium, sodium, lithium, barium, or mixtures thereof. In some embodiments, the detergent does not contain barium. The low-based / neutral detergents may be selected from sulfonate, phenate, or salicylate detergents. In some embodiments, the low-based / neutral detergent is a calcium-containing detergent or a mixture of calcium-containing detergents. In some embodiments, the low-based / neutral detergent is a calcium sulfonate detergent or a calcium phenate detergent. In embodiments, the one or more detergents include a mixture of one or more low-based / neutral calcium-containing detergents and one or more overbased calcium-containing detergents.

[0090] The one or more detergents may include overbased calcium-containing detergents and low-based / neutral detergents that are salts of alkali metals or alkaline earth metals other than calcium.

[0091] The amount of calcium provided by the one or more calcium-containing detergents is greater than about 0.01 wt.%, or greater than about 0.02 wt.%, or up to about 0.25 wt.%, or from about 0.010 wt.% to about 0.25 wt.%, or from about 0.02 wt.% to about 0.20 wt.%, or from about 0.02 wt.% to about 0.15 wt.%, where the amount is based on the total weight of the lubricating oil composition.

[0092] The low based / neutral detergent may provide calcium in an amount that constitutes at least 0.001 wt. % of the calcium provided by the total detergents in the lubricating oil composition. In some embodiments, the low based / neutral detergent may provide calcium in an amount that constitutes at least 0.003 wt. %, or between 0.003 wt. % and 0.05 wt. % of the calcium provided by the total detergents in the lubricating oil composition.

[0093] In certain embodiments, the one or more low based / neutral detergents provide the lubricating oil composition with from about 1 ppmw to about 400 ppmw of calcium by weight, based on the total weight of the lubricating oil composition. In some embodiments, the one or more low based / neutral calcium-containing detergents provide the lubricating oil composition with from 1 ppmw to 350 ppmw of calcium by weight, based on the total weight of the lubricating oil composition.

[0094] In some embodiments, detergents are effective in suspending deleterious products that are formed in the lubricating oil composition during engine use.

[0095] The amount of calcium provided by the one or more overbased calcium-containing detergents can be greater than about 300 ppmw, or greater than 500 ppmw, or greater than 950 ppmw, or up to about 4000 ppmw, or up to about 3500 ppmw, or up to about 3000 ppmw, or from about 300 ppmw to about 4000 ppmw, or from about 500 ppmw to about 3500 ppmw, or from about 950 ppmw to about 3000 ppmw, or from about 1000 ppmw to about 2750 ppmw, or from about 950 to about 2500, based on the total weight of the lubricating oil composition.

[0096] The low based / neutral detergent may provide calcium in an amount that constitutes at least 0.01 wt.% of the calcium provided by the total detergents in the lubricating oil composition. In some embodiments, the low based / neutral detergent may provide calcium in an amount that constitutes at least 0.5 wt.%, or at least 1 wt.%, or from 0.01 wt.% to 12 wt.% of the calcium provided by the total detergents in the lubricating oil composition.

[0097] In certain embodiments, the one or more low based / neutral detergents provide the lubricating oil composition with from about 0 ppmw to about 1000 ppmw by weight of calcium, based on the total weight of the lubricating oil composition. In some embodiments, the one or more low based / neutral calcium-containing detergents provide the lubricating oil composition with from 25 ppmw to less than 800 ppmw by weight, or from 50 ppmw to 600 ppmw by weight, or from 70 to 300 ppm by weight of calcium, based on the total weight of the lubricating oil composition.

[0098] In some embodiments, detergents are effective in suspending deleterious products that are formed in the lubricating oil composition during engine use.

[0099] The one or more detergents may be present at from about 0 wt % to about 10 wt %, or from about 0.1 wt % to about 8 wt %, or from about 1 wt % to about 4 wt %, or from greater than about 4 wt % to about 8 wt %, based on the total weight of the lubricating oil composition.

[0100] Zinc dialkyldithiophosphate compounds The lubricating oil composition includes an amount of one or more zinc dialkyl dithiophosphate compounds (ZDDPs).

[0101] The ZDDP is present in the lubricating oil composition in an amount of from about 0.01 wt % to about 15 wt %, or from about 0.01 wt % to about 10 wt %, or from about 0.05 wt % to about 5 wt %, or from about 0.1 wt % to about 3 wt %, or from about 0.1 wt % to about 2 wt %, based on the total weight of the lubricating oil composition.

[0102] ZDDP compounds may include ZDDPs derived from primary alkyl alcohols, secondary alkyl alcohols, or combinations of primary and secondary alkyl alcohols. The primary and secondary alkyl alcohols used to prepare the ZDDP agents may have alkyl groups containing 1 to 20 carbon atoms, or about 1 to 18 carbon atoms, or about 1 to about 16 carbon atoms, or 2 to 12 carbon atoms, or about 3 to about 8 carbon atoms. Preferably, the primary alkyl alcohol has a branch at the beta carbon to the hydroxyl group.

[0103] For example, an alcohol having a branch at the beta (β) carbon will have the branch at the second carbon counting from the oxygen atom of the hydroxyl group.

[0104] [ka]

[0105] Suitable examples of primary and secondary alkyl alcohols for use in preparing the ZDDP agent may be selected from n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, 2-butanol, isobutyl alcohol, n-pentyl alcohol, amyl alcohol, hexanol, methyl isobutyl carbinol, isohexanol, n-heptanol, isoheptanol, octanol, nonanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol, pentadecanol, hexadecanol, heptadecanol, octadecanol, nonadecanol, eicosanol, and 2-ethylhexanol.

[0106] The molar ratio of the primary alkyl alcohol to the secondary alkyl alcohol used to make the ZDDP in the lubricating oil composition is about 100:0 to 0:100, or about 100:0 to 50:50, or 100:0 to 60:40. Preferably, the molar ratio of the primary alkyl alcohol to the secondary alkyl alcohol used to make the ZDDP in the lubricating oil composition is 100:0 or 0:100. The ZDDP may have a P:Zn ratio of about 1.08 to 1.3, or about 1.08 to 1.2, or about 1.09 to about 1.15.

[0107] In some embodiments, the additive composition comprises at least two different zinc dialkyldithiophosphate compounds. The two alkyl groups on the zinc dialkyldithiophosphate compounds can be the same or different.

[0108] In some embodiments, 100 mole percent of the alkyl groups of the one or more zinc dialkyldithiophosphate compounds can be derived from one or more primary alcohol groups. In some embodiments, 100 mole percent of the alkyl groups of the one or more zinc dialkyldithiophosphate compounds can be derived from one or more secondary alcohol groups.

[0109] The alcohol suitable for producing the zinc dialkyldithiophosphate salt can be a primary alkyl alcohol, a secondary alkyl alcohol. In an embodiment, the additive package includes two or more zinc dialkyldithiophosphate salts, the first of which is derived from an alcohol containing a primary alkyl group, and the second of which is derived from an alcohol containing a secondary alkyl group. In another embodiment, the zinc dialkyldithiophosphate compound is derived from at least two secondary alcohol groups. The alcohol can contain either branched, cyclic, or linear.

[0110] The one or more zinc dialkyldithiophosphate salts may be oil-soluble salts of dihydrocarbyl dithiophosphoric acids and may be represented by the formula:

[0111] [ka] In the formula, R5 and R6 can be the same or different alkyl groups containing 1 to 20 carbon atoms, or about 1 to 18 carbon atoms, or about 1 to about 16 carbon atoms, or 2 to 12 carbon atoms, or about 3 to about 8 carbon atoms, and including moieties such as alkyl and cycloalkyl moieties. Thus, the moieties can be, for example, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, amyl, n-hexyl, i-hexyl, n-octyl, decyl, dodecyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl, 2-ethylhexyl, cyclohexyl, or methylcyclopentyl.

[0112] The average number of total carbon atoms per mole of phosphorus in a ZDDP compound can be calculated by the sum of the carbon atoms in the four alkyl groups R5 and R6 provided to the ZDDP compound by the alcohol used to make the ZDDP compound, divided by 2. For example, in a single ZDDP compound, if R5 is a C3-alkyl group and R6 is a C6 alkyl group, the total number of carbon atoms is 3+3+6+6=18. Dividing this by the 2 moles of phosphorus per mole of ZDDP gives an average total of 9 carbon atoms per mole of phosphorus.

[0113] The average total number of carbon atoms per mole of phosphorus (ATCP) for a composition containing one or more ZDDP compounds can be calculated from the alcohol used to produce the ZDDP compound according to the following formula: ATCP=2 * [(mol% of Alc1 * (number of C atoms in alc1) + (mol% of alc2 * (number of C atoms in alc2) + (mol% of alc3 * number of C atoms in alc3) +... etc. In the formula, alc1, alc2, and alc3 each represent a different alcohol used to make the ZDDP compound, and the mole percent is the mole percentage of each alcohol that was present in the reaction mixture used to make the ZDDP compound. "And so forth" indicates that if more than three alcohols are used to make the ZDDP compound, the formula can be expanded to include each alcohol present in the reaction mixture.

[0114] The average total number of carbon atoms from both R5 and R6 of the ZDDP is greater than 2 carbon atoms per mole of phosphorus, and in one embodiment in the range of greater than 4 to 40 carbon atoms, or greater than 6 to about 20 carbon atoms, and in one embodiment in the range of greater than 6 to about 16 carbon atoms, and in one embodiment in the range of about 6 to about 15 carbon atoms, and in one embodiment in the range of about 9 to about 15 carbon atoms, and in one embodiment about 12 carbon atoms per mole of phosphorus.

[0115] The zinc dialkyldithiophosphate salts can be prepared according to known techniques by first forming a dialkyldithiophosphoric acid (DDPA), usually by reaction with one or more alcohols, and then neutralizing the formed DDPA with a zinc compound. Any basic or neutral zinc compound can be used to make the zinc salt, but oxides, hydroxides, and carbonates are most commonly used. The zinc dialkyldithiophosphates of component (i) can be made by processes such as those generally described in U.S. Pat. No. 7,368,596.

[0116] In some embodiments, at least one zinc dialkyldithiophosphate salt may be present in the lubricating oil in an amount sufficient to provide from about 10 ppmw zinc to about 1300 ppmw zinc, or from about 100 ppmw zinc to about 1200 ppmw zinc, or from about 200 ppmw zinc to about 1100 ppmw zinc, based on the total weight of the lubricating oil composition.

[0117] In some embodiments, at least one zinc dialkyldithiophosphate salt may be present in the lubricating oil in an amount sufficient to provide from about 100 to about 1200 ppm phosphorus, or from about 200 to about 1100 ppm phosphorus, or from about 300 to about 1000 ppm phosphorus, or from about 400 to about 1000 ppm phosphorus, or from about 550 to about 1000 ppm phosphorus, based on the total weight of the lubricating oil composition.

[0118] The present invention may include overbased ZDDPs, which are basic ZDDPs. The term basic ZDDPs, or equivalent expressions, is used herein to describe zinc salts in which the metal substituent is present in a stoichiometrically greater amount than the phosphate radical. For example, a standard or neutral zinc phosphorodithioate has two equivalents (i.e., one mole) of zinc per two equivalents (i.e., two moles) of phosphorodithioic acid, while a basic zinc diorganophosphorodithioate has more than two equivalents of zinc per two equivalents of phosphorodithioic acid.

[0119] For example, overbasing can be carried out using a basic zinc compound such as zinc oxide. The amount of basic zinc compound required to give the desired overbasing is not critical. The essential factor is that sufficient zinc compound is present in the reaction mixture for the overbasing reaction. Although not absolutely essential, it has been found that the reaction proceeds in a more satisfactory manner when a slight excess of zinc compound is used over the amount required for the reaction. This excess should be kept to a minimum level relative to the need to remove large amounts of solids from the final product. As a general statement, the excess of zinc compound should not exceed 10-15% by weight.

[0120] Viscosity modifier The lubricating oil composition of the present disclosure includes one or more viscosity modifiers (also known as viscosity index improvers and viscosity improvers). Viscosity modifiers provide the lubricant with high and low temperature operability. These additives impart shear stability at high temperatures and acceptable viscosity at low temperatures. The viscosity modifiers may be one or more dispersant viscosity modifiers that function as both viscosity modifiers and dispersants. Preferably, the lubricating oil composition includes one or more non-dispersant viscosity modifiers.

[0121] The one or more non-dispersant viscosity modifiers may be hydrocarbon polymers, which may be polyolefins having a backbone consisting essentially of aliphatic olefins, particularly alpha olefin monomers. Thus, polyolefins in this embodiment exclude polymers having a large component of other types of monomers copolymerized in the main polymer, such as ester monomers, acid monomers, and the like. Polyolefins may contain impurity amounts of such materials, e.g., less than 5% by weight, more often less than 1% by weight, and preferably less than 0.1% by weight, of other monomers. Useful polymers include those made of ethylene and C3-C6 28 Included are oil soluble or dispersible copolymers of alpha-olefins, or ethylene and C3-C8 alpha-olefins, or ethylene and C3-C6 alpha-olefins, or ethylene and C3-C4 alpha-olefins.

[0122] Olefin copolymers (sometimes referred to as polyolefins) can be random, block, and random block copolymers. Ethylene propylene copolymers are usually random or statistical copolymers. Random or statistical copolymers can be a mixture of two or more polymers made in two or more reactors in series. Block copolymers can be obtained by carrying out the reaction in a tubular reactor. Such a procedure is described in U.S. Pat. No. 4,804,794, which is incorporated herein by reference for its relevant disclosure in this regard. These polymers are commercially available as PARATONE® 8941 and PARATONE® 8910 (sold by Chevron Oronite Company LLC). Block copolymers can also be obtained by selecting the appropriate catalyst and / or process for polymerization. Such polymers are described in U.S. Pat. App. Pub. No. 2006 / 0199896, which is incorporated herein by reference for its relevant disclosure in this regard. Such olefin block copolymers are commercially available from Dow Chemical under the trade name INFUSE™ olefin block copolymers.

[0123] Numerous U.S. patents describe the preparation of copolymers of alpha olefins, including: Copolymers of ethylene and higher alpha olefins are the most common copolymers of aliphatic olefins. Ethylene-propylene copolymers are the most common ethylene-alpha-olefin copolymers and are preferred for use in the present invention. A description of ethylene-propylene copolymers can be found in U.S. Pat. No. 4,137,185, which is incorporated herein by reference. Useful ethylene-alpha olefins, typically ethylene-propylene copolymers, are commercially available. Ethylene-alpha olefin copolymers containing about 30 to about 60 weight percent of monomer units derived from ethylene are commonly referred to as low ethylene or amorphous copolymers. Ethylene alpha-olefin copolymers containing about 60 to about 80 weight percent of units derived from ethylene are commonly referred to as high ethylene (semicrystalline) polymers. In an embodiment, the one or more non-dispersant viscosity modifiers are ethylene-propylene copolymers having about 40 to about 60 weight percent ethylene and about 60 to about 40 weight percent propylene, the weight percent being based on the total weight of the olefin polymer. In another embodiment, the olefin polymer is an ethylene-propylene copolymer having about 45 to about 55 weight percent ethylene and about 55 to about 45 weight percent propylene, the weight percent being based on the total weight of the olefin polymer. The polymer substrate (i.e., the portion of the olefin polymer that is the backbone without the substituents) can also contain a mixture of amorphous and semi-crystalline polymers in weight ratios as described in U.S. Pat. No. 5,427,702, which is incorporated herein by reference. Exemplary commercially available polymers including amorphous copolymers are PARATONE® 8921 available from Chevron Oronite, LZ7067, LZ7065, and LZ7060 available from Lubrizol Corporation, Keltan® 1200A, 1200B available from Lanxess, and NDR125 available from Dow Chemical Company.

[0124] Olefin polymers (sometimes referred to as polyolefins) having a backbone consisting essentially of aliphatic olefins may be polymers containing dienes. The olefin polymers may be homopolymers or copolymers of one or more dienes. The dienes may be conjugated, such as isoprene, butadiene, 2,3-dimethyl-1,3-butadiene, chloroprene, 1,3-butadiene, and piperylene, or non-conjugated, such as 1,4-hexadiene, ethylidene norbornene, vinyl norbornene, 4-vinylcyclohexene, and dicyclopentadiene. Polymers of conjugated dienes are preferred. In embodiments, the total carbon content of the diene may not exceed 20 carbons. Such polymers are conveniently prepared via free radical and anionic polymerization techniques. Emulsion techniques are commonly used for free radical polymerization.

[0125] The olefin polymer having a backbone consisting essentially of aliphatic olefins may be a copolymer of a conjugated diene and a vinyl-substituted aromatic compound. In one embodiment, the olefin polymer is a copolymer of a vinyl-substituted aromatic compound and a conjugated diene. The vinyl-substituted aromatic generally contains 8 to about 20 carbon atoms, preferably 8 to 12 carbon atoms, and most preferably 8 or 9 carbon atoms. Examples of vinyl-substituted aromatic compounds include vinyl anthracene, vinyl naphthalene, and vinyl benzene (styrene-based compounds). Styrenic compounds are preferred, examples of which are styrene, alpha-methylstyrene, ortho-methylstyrene, meta-methylstyrene, para-methylstyrene, para-tertiary-butylstyrene, and chlorostyrene, with styrene being preferred. The vinyl-substituted aromatic content of these copolymers typically ranges from about 15% to about 70% by weight, or from about 20% to about 40% by weight, based on the total weight of the copolymer. The aliphatic conjugated diene content of these copolymers typically ranges from about 30% to about 85% by weight, or from about 60% to about 80% by weight, based on the total weight of the copolymer.

[0126] The polymers, especially styrene-diene copolymers, can be random or block copolymers, including regular or random block copolymers. Random copolymers are copolymers in which the comonomers are randomly or nearly randomly arranged in the polymer chain, and the homopolymers of either monomer are not significantly blocked. Regular block copolymers are copolymers in which a small number of relatively long chains of homopolymers of one type of monomer are alternately bonded to a small number of relatively long chains of homopolymers of another type of monomer. Random block copolymers are copolymers in which a large number of relatively short segments of homopolymers of one type of monomer alternate with relatively short segments of homopolymers of another monomer. Block copolymers, especially diblock copolymers, are preferred. Examples of such polymer substrates are illustrated in U.S. Pat. Nos. 6,162,768, 6,215,033, 6,248,702, and 6,034,184, which are incorporated herein by reference.

[0127] The random, regular block and random block polymers used in the present invention can be linear, or they can be partially or highly branched. The relative arrangement of the homopolymer segments in the linear regular block or random block polymers is obvious. The difference in the structure is in the number and relative size of the homopolymer segments, the arrangement in either type of linear block polymer always alternating with the homopolymer segments.

[0128] Normal or regular block copolymers usually have from 1 to about 5, often from 1 to about 3, and preferably only 1 to about 2 relatively large homopolymer blocks of each monomer. The size of the blocks is not necessarily the same and can vary considerably. The only stipulation is that any regular block copolymer contains relatively few but relatively large alternating homopolymer segments.

[0129] These olefin polymers having a backbone consisting essentially of aliphatic olefins can be hydrogenated to reduce the amount of olefinic unsaturation present in the polymer. They may or may not be fully hydrogenated. Hydrogenation is often accomplished using catalytic methods. Catalytic techniques using hydrogen under high pressure and temperature are well known to those skilled in the chemical arts. Other methods are also useful and known to those skilled in the art. An extensive discussion of diene polymers can be found in "Encyclopedia of Polymer Science and Engineering", Volume 2, pp. 550-586 and Volume 8, pp. 499-532, Wiley-Interscience (1986), which are expressly incorporated herein by reference for their relevant disclosures in this regard. As a specific example, U.S. Patent No. 3,959,161 teaches the preparation of hydrogenated polybutadiene. In another example, 1,4-polyisoprene, upon hydrogenation, becomes an alternating copolymer of ethylene and propylene. Copolymers of conjugated dienes are prepared from two or more conjugated dienes. Useful dienes are the same as those described above in the preparation of homopolymers of conjugated dienes. For example, U.S. Patent No. 4,073,737 describes the preparation and hydrogenation of butadiene-isoprene copolymers.

[0130] The olefin copolymers may have a weight average molecular weight (Mw), as determined by gel permeation chromatography using polystyrene standards, ranging from about 7,000 g / mol to about 500,000 g / mol, or about 20,000 g / mol to about 400,000 g / mol, or about 100,000 g / mol to about 300,000 g / mol. Exemplary polydispersity values ​​(Mw / Mn) range from about 1.5 to about 10, or from about 1.5 to about 3.0, or from about 1.7 to about 3.0, or from about 2.0 to about 2.5.

[0131] Suitable viscosity modifiers may include high molecular weight polyesters or functionalized polyolefins, such as ethylene-propylene copolymers functionalized with the reaction product of an acylating agent (such as maleic anhydride) with an amine, amine-functionalized polymethacrylates, or esterified maleic anhydride-styrene copolymers reacted with amines.Typical molecular weights (Mw) of these polymers are from 10,000 g / mol to 1,500,000 g / mol, more typically from 20,000 g / mol to 1,200,000 g / mol, and even more typically from 50,000 g / mol to 1,000,000 g / mol, as determined by gel permeation chromatography using polystyrene standards.

[0132] Examples of suitable viscosity modifiers include linear or star polymers and copolymers of methacrylates, such as copolymers of various chain length alkyl methacrylates.

[0133] Suitable non-dispersant olefin copolymer viscosity modifiers are the non-polar hydrogenated olefin copolymer type viscosity modifiers, such as the LUBRIZOL 7075™ series manufactured by LUBRIZOL (Wickliffe, Ohio). Hydrogenated olefin copolymers are the most widely used type of viscosity modifier for passenger car motor oils and heavy duty diesel engine oils.

[0134] The shear stability index (SSI) of the polymer substrate (i.e., the portion of the olefin polymer that is the backbone without any substituent groups) typically ranges from about 3 to about 60, or from about 5 to about 50, or from about 15 to about 40, or from about 25 to about 35. SSI is measured using test method ASTM-D6278 for evaluating the shear stability of polymer-containing fluids. The test method measures the percent viscosity loss at 100° C. of the polymer-containing fluid as evaluated by a diesel injector rig procedure using the European diesel injector test facility. The viscosity loss reflects the polymer degradation due to shear in the nozzle.

[0135] In embodiments of the present disclosure, the viscosity modifier and / or dispersant viscosity modifier may be used in an amount that is greater than about 0.5 wt%, or from about 0.5 wt% to about 30 wt%, or from about 1.0 wt% to about 25 wt%, or from about 2.0 wt% to about 20 wt%, or from about 2.5 wt% to about 15 wt%, or from about 3 wt% to about 10 wt%, or from about 5 wt% to about 10 wt%, based on the total weight of the lubricating oil composition.

[0136] In some embodiments of the present disclosure, the lubricating oil composition comprises two or more viscosity modifiers and / or dispersant viscosity modifiers.

[0137] Antioxidants The lubricating oil composition herein may also optionally contain one or more antioxidants. Antioxidant compounds are known and include, for example, phenates, phenate sulfides, sulfurized olefins, phosphosulfurized terpenes, sulfurized esters, aromatic amines, alkylated diphenylamines (e.g., nonyldiphenylamine, di-nonyldiphenylamine, octyldiphenylamine, di-octyldiphenylamine), phenyl-alpha-naphthylamines, alkylated phenyl-alpha-naphthylamines, hindered non-aromatic amines, phenols, hindered phenols, oil-soluble molybdenum compounds, polymeric antioxidants, or mixtures thereof. The antioxidant compounds may be used alone or in combination.

[0138] The hindered phenol antioxidant may contain secondary butyl and / or tertiary butyl groups as steric hindrance groups. The phenol group may be further substituted with a hydrocarbyl group and / or a bridging group that connects to a second aromatic group. Examples of suitable hindered phenol antioxidants include 2,6-di-tert-butylphenol, 4-methyl-2,6-di-tert-butylphenol, 4-ethyl-2,6-di-tert-butylphenol, 4-propyl-2,6-di-tert-butylphenol or 4-butyl-2,6-di-tert-butylphenol, or 4-dodecyl-2,6-di-tert-butylphenol. In one embodiment, the hindered phenol antioxidant may be an ester, but may include, for example, Irganox™ L-135 available from BASF or an addition product derived from 2,6-di-tert-butylphenol and an alkyl acrylate. Additionally, the alkyl group may contain from about 1 to about 18, or from about 2 to about 12, or from about 2 to about 8, or from about 2 to about 6, or about 4 carbon atoms. Another commercially available hindered phenol antioxidant, which may be an ester, may include Ethanox™ 4716 available from Albemarle Corporation.

[0139] Useful antioxidants may include diarylamines and high molecular weight phenols. In one embodiment, the lubricating oil composition may contain a mixture of diarylamines and high molecular weight phenols, such that each antioxidant may be present in an amount sufficient to provide up to about 5 wt. %, based on the final weight of the lubricating oil composition. In one embodiment, the antioxidant may be a mixture of about 0.3 to about 1.5 wt. % diarylamines and about 0.4 to about 2.5 wt. % high molecular weight phenols, based on the final weight of the lubricating oil composition.

[0140] Examples of suitable olefins that can be sulfurized to form sulfurized olefins include propylene, butylene, isobutylene, polyisobutylene, pentene, hexene, heptene, octene, nonene, decene, undecene, dodecene, tridecene, tetradecene, pentadecene, hexadecene, heptadecene, octadecene, nonadecene, eicosene, or mixtures thereof. In one embodiment, hexadecene, heptadecene, octadecene, nonadecene, eicosene, or mixtures thereof, as well as their dimers, trimers, and tetramers, are particularly useful olefins. Alternatively, the olefins can be Diels-Alder adducts of dienes such as 1,3-butadiene and unsaturated esters such as butyl acrylate.

[0141] Another class of sulfurized olefins includes sulfurized fatty acids and their esters. The fatty acids are often derived from vegetable or animal oils and typically contain from about 4 to about 22 carbon atoms. Examples of suitable fatty acids and their esters include triglycerides, oleic acid, linoleic acid, palmitoleic acid, or mixtures thereof. Often, the fatty acids are derived from lard oil, tall oil, peanut oil, soybean oil, cottonseed oil, sunflower seed oil, or mixtures thereof. The fatty acids and / or esters may be mixed with olefins, such as α-olefins.

[0142] In another alternative embodiment, the antioxidant composition contains a molybdenum-containing antioxidant in addition to the phenolic and / or aminic antioxidants discussed above. When a combination of these three antioxidants is used, preferably the ratio of phenolic to amine to molybdenum-containing is (0-2):(0-2):(0-1).

[0143] The 0.5 or more antioxidants may be present in the range of from about 0% to about 20%, or from about 0.1% to about 10%, or from about 1% to about 5% by weight of the lubricating oil composition.

[0144] Anti-wear Agent The lubricating oil composition herein may also optionally contain one or more antiwear agents. Examples of suitable antiwear agents include, but are not limited to, metal thiophosphates; metal dialkyldithiophosphates; phosphoric acid esters or salts thereof; phosphoric acid esters; phosphites; phosphorus-containing carboxylic acid esters, ethers, or amides; sulfurized olefins; thiocarbamate-containing compounds, such as thiocarbamate esters, alkylene-linked thiocarbamates, and bis(S-alkyldithiocarbamyl) disulfides; and mixtures thereof. A suitable antiwear agent may be molybdenum dithiocarbamate. Phosphorus-containing antiwear agents are described more fully in EP 612839. The metal in the dialkyldithiophosphate salt may be an alkali metal, an alkaline earth metal, aluminum, lead, tin, molybdenum, manganese, nickel, copper, titanium, or zinc. A useful antiwear agent may be zinc dialkyldithiophosphate.

[0145] Further examples of suitable antiwear agents include titanium compounds, tartrates, tartrimides, oil-soluble amine salts of phosphorus compounds, sulfurized olefins, phosphites (e.g., dibutyl phosphite), phosphonates, thiocarbamate-containing compounds such as thiocarbamate esters, thiocarbamate amides, thiocarbamic acid ethers, alkylene-linked thiocarbamates, and bis(S-alkyldithiocarbamyl) disulfides. The tartrates or tartrimides may contain alkyl-ester groups, but the total of carbon atoms on the alkyl group may be at least 8. The antiwear agent may, in one embodiment, include citrates.

[0146] The antiwear agent may be present in a range including from about 0% to about 15%, or from about 0.01% to about 10%, or from about 0.05% to about 5%, or from about 0.1% to about 3% by weight of the lubricating oil composition.

[0147] Boron-Containing Compounds The lubricating oil compositions herein may optionally contain other boron-containing compounds in addition to one or more boron-containing dispersants discussed above.

[0148] Examples of boron-containing compounds include boric acid esters, borated fatty amines, borated epoxides, and borated dispersants, as disclosed in US Pat. No. 5,883,057.

[0149] When present, the boron-containing compound may be used in an amount sufficient to provide up to about 8 wt. %, from about 0.01 wt. % to about 7 wt. %, from about 0.05 wt. % to about 5 wt. %, or from about 0.1 wt. % to about 3 wt. % of the lubricating oil composition.

[0150] Friction modifiers The lubricating oil composition herein may also optionally contain a friction modifier in addition to one or more esters of polyhydric alcohols discussed above.Suitable friction modifiers may include metal-containing and metal-free friction modifiers, which may include, but are not limited to, imidazolines, amides, amines, succinimides, alkoxylated amines, alkoxylated ether amines, amine oxides, amidoamines, nitriles, betaines, quaternary amines, imines, amine salts, aminovanidines, alkanolamides, phosphonates, metal-containing compounds, sulfurized fatty compounds and olefins, sunflower oil, other naturally occurring vegetable or animal oils, dicarboxylic acid esters, polyols, and esters or partial esters of one or more aromatic carboxylic acids.

[0151] Suitable friction modifiers may contain hydrocarbyl groups selected from linear, branched, or aromatic hydrocarbyl groups, or mixtures thereof, and may be saturated or unsaturated. The hydrocarbyl groups may be composed of carbon and hydrogen or heteroatoms such as sulfur or oxygen. The hydrocarbyl groups may range from about 12 to about 25 carbon atoms. In some embodiments, the friction modifier may be a long chain fatty acid ester. In other embodiments, the long chain fatty acid ester may be a mono-ester, or a di-ester, or a (tri)glyceride. The friction modifier may be a long chain fatty amide, a long chain fatty ester, a long chain fatty epoxide derivative, or a long chain imidazoline.

[0152] Other suitable friction modifiers may include organic, ashless (metal-free), nitrogen-free mechanical friction modifiers. Such friction modifiers include esters formed by reacting carboxylic acids and anhydrides with alkanols, and generally may include polar end groups (e.g., carboxyl or hydroxyl) covalently bonded to an oleophilic hydrocarbon chain. Other suitable friction modifiers are described in U.S. Patent No. 6,723,685, the entirety of which is incorporated herein by reference.

[0153] Aminic friction modifiers may include amines or polyamines. Such compounds may have hydrocarbyl groups that are linear, either saturated or unsaturated, or a mixture thereof, and may contain from about 12 to about 25 carbon atoms. Further examples of suitable friction modifiers include alkoxylated amines and alkoxylated ether amines. Such compounds may have hydrocarbyl groups that are linear, either saturated or unsaturated, or a mixture thereof. They may contain from about 12 to about 25 carbon atoms. Examples include ethoxylated amines and ethoxylated ether amines.

[0154] The amines and amides may be used by themselves or in the form of adducts or reaction products with boron compounds such as boron oxides, boron halides, metaborates, boric acid or mono-, di-, or tri-alkyl borates. Other suitable friction modifiers are described in U.S. Patent No. 6,300,291, which is incorporated herein by reference in its entirety.

[0155] Friction modifiers may optionally be present in ranges such as from about 0% to about 10% by weight, or from about 0.01% to about 8% by weight, or from about 0.1% to about 4% by weight.

[0156] Molybdenum-Containing Components The lubricating oil composition herein may also optionally contain one or more molybdenum-containing compounds. The oil-soluble molybdenum compounds may have the functional properties of antiwear agents, antioxidants, friction modifiers, or mixtures thereof. The oil-soluble molybdenum compounds may include molybdenum dithiocarbamates, molybdenum dialkyldithiophosphates, molybdenum dithiophosphinates, amine salts of molybdenum compounds, molybdenum xanthates, molybdenum thioxanthates, molybdenum sulfides, molybdenum carboxylates, molybdenum alkoxides, trinuclear organomolybdenum compounds, and / or mixtures thereof. The molybdenum sulfides include molybdenum disulfide. The molybdenum disulfide may be in the form of a stable dispersion. In one embodiment, the oil-soluble molybdenum compounds may be selected from the group consisting of molybdenum dithiocarbamates, molybdenum dialkyldithiophosphates, amine salts of molybdenum compounds, and mixtures thereof. In one embodiment, the oil soluble molybdenum compound can be a molybdenum dithiocarbamate.

[0157] Suitable examples of molybdenum compounds that may be used include commercially available materials sold under trade names such as Molyvan 822™, Molyvan™ A, Molyvan 2000™, and Molyvan 855™ from R.T. Vanderbilt Co., Ltd., and Sakura-Lube™ S-165, S-200, S-300, S-310G, S-525, S-600, S-700, and S-710 available from Adeka Corporation, and mixtures thereof. Suitable molybdenum components are described in U.S. Patent No. 5,650,381, U.S. Reissue Patent Nos. 37,363 (E1), 38,929 (E1), and 40,595 (E1), the entireties of which are incorporated herein by reference.

[0158] Additionally, the molybdenum compound can be an acidic molybdenum compound, including molybdic acid, ammonium molybdate, sodium molybdate, potassium molybdate, and other alkali metal molybdates and other molybdenum salts, such as sodium hydrogen molybdate, MoOCl4, MoO2Br2, Mo2O3Cl6, molybdenum trioxide, or similar acidic molybdenum compounds. Alternatively, the composition can provide the molybdenum through a molybdenum / sulfur complex of a basic nitrogen compound, as described, for example, in U.S. Pat. Nos. 4,263,152, 4,285,822, 4,283,295, 4,272,387, 4,265,773, 4,261,843, 4,259,195, and 4,259,194, and WO 94 / 06897, the foregoing patents being incorporated herein by reference in their entireties.

[0159] Another class of suitable organo-molybdenum compounds is the trinuclear molybdenum compounds, e.g., those of the formula MoS k L n Q z and mixtures thereof, where S represents sulfur, L represents an independently selected ligand having an organic group having a sufficient number of carbon atoms to render the compound soluble or dispersible in oil, n is 1 to 4, k varies from 4 to 7, Q is selected from the group of neutral electron donor compounds, such as water, amines, alcohols, phosphines, and ethers, and z ranges from 0 to 5, including non-stoichiometric values. At least 21 total carbon atoms may be present, with at least 25, at least 30, or at least 35 carbon atoms present among all of the ligand organic groups. Additional suitable molybdenum compounds are described in U.S. Pat. No. 6,723,685, which is incorporated herein by reference in its entirety.

[0160] The oil soluble molybdenum compound may be present in an amount sufficient to provide from about 0.5 ppm to about 2000 ppm, from about 1 ppm to about 700 ppm, from about 1 ppm to about 550 ppm, from about 5 ppm to about 300 ppm, or from about 20 ppm to about 250 ppm of molybdenum.

[0161] Transition metal-containing compounds In another embodiment, the oil-soluble compound can be a transition metal-containing compound or metalloid. Transition metals can include, but are not limited to, titanium, vanadium, copper, zinc, zirconium, molybdenum, tantalum, tungsten, etc. Suitable metalloids include, but are not limited to, boron, silicon, antimony, tellurium, etc.

[0162] In some embodiments, the oil-soluble transition metal-containing compound may function as an antiwear agent, a friction modifier, an antioxidant, an adhesion control additive, or two or more of these functions. In some embodiments, the oil-soluble transition metal-containing compound may be an oil-soluble titanium compound, such as titanium (IV) alkoxide. Among the titanium-containing compounds that may be used in or for the preparation of oil-soluble materials in the technology of the present disclosure, include various Ti (IV) compounds, such as titanium (IV) oxide; titanium (IV) sulfide; titanium (IV) nitrate; titanium (IV) alkoxides, such as titanium methoxide, titanium ethoxide, titanium propoxide, titanium isopropoxide, titanium butoxide, titanium 2-ethylhexoxide; and other titanium compounds or complexes, such as, but not limited to, titanium phenate; titanium carboxylates, such as titanium (IV) 2-ethyl-1,3-hexanedioate or titanium citrate or titanium oleate; and titanium (IV) (triethanolaminato) isopropoxide. Other forms of titanium encompassed by the disclosed technology include titanium phosphates, such as titanium dithiophosphates (e.g., dialkyl dithiophosphates) and titanium sulfonates (e.g., alkyl benzene sulfonates), or generally reaction products of titanium compounds with various acidic materials to form salts, such as oil-soluble salts. Thus, titanium compounds may be derived from organic acids, alcohols, and glycols, among others. Ti compounds may also exist in dimeric or oligomeric forms containing Ti-O-Ti structures. Such titanium materials are commercially available or can be readily prepared by suitable synthetic techniques that will be apparent to those skilled in the art. They may exist at room temperature as solids or liquids, depending on the particular compound. They may also be provided in solution form in a suitable inert solvent.

[0163] In one embodiment, titanium may be provided as a Ti-modified dispersant, such as a succinimide dispersant. Such materials may be prepared by forming a titanium mixed anhydride between a titanium alkoxide and a hydrocarbyl-substituted succinic anhydride, such as an alkenyl-(or alkyl) succinic anhydride. The resulting titanate-succinate intermediate may be used directly or may be reacted with any of several materials, such as (a) polyamine-based succinimide / amide dispersants having free condensable -NH functional groups; (b) components of polyamine-based succinimide / amide dispersants, i.e., alkenyl (or alkyl) succinic anhydrides and polyamines; (c) hydroxy-containing polyester dispersants prepared by reaction of substituted succinic anhydrides with polyols, amino alcohols, polyamines, or mixtures thereof. Alternatively, the titanate-succinate intermediate can be reacted with other agents such as alcohols, amino alcohols, ether alcohols, polyether alcohols or polyols, or fatty acids, and the product can be used directly to impart Ti to a lubricant or can be further reacted with a succinic dispersant as described above. As an example, one part (mol) of tetraisopropyl titanate can be reacted with about two parts (moles) of polyisobutene-substituted succinic anhydride at 140-150°C for 5-6 hours to provide a titanium modified dispersant or intermediate. The resulting material (30 g) can be further reacted with a succinimide dispersant from a polyisobutene-substituted succinic anhydride and polyethylene polyamine mixture (127 grams + diluent oil) at 150°C for 1.5 hours to produce a titanium modified succinimide dispersant.

[0164] Another titanium-containing compound is titanium alkoxide and C6-C 25 It may be a reaction product with a carboxylic acid. The reaction product has the following formula:

[0165] [ka] wherein n is an integer selected from 2, 3, and 4, and R is a hydrocarbyl group containing from about 5 to about 24 carbon atoms, or the following formula:

[0166] [ka] where m+n=4, n ranges from 1 to 3, R4 is an alkyl moiety having from 1 to 8 carbon atoms, R1 is selected from hydrocarbyl groups containing from about 6 to 25 carbon atoms, and R2 and R3 are the same or different and are selected from hydrocarbyl groups containing from 1 to 6 carbon atoms, or a compound of the formula:

[0167] [ka] (wherein x ranges from 0 to 3; R1 is selected from hydrocarbyl groups containing about 6 to 25 carbon atoms; R2 and R3 are the same or different and are selected from hydrocarbyl groups containing about 1 to 6 carbon atoms; R4 is H, C6-C 25 The carboxylic acid moiety may be selected from the group consisting of

[0168] Suitable carboxylic acids may include, but are not limited to, caproic acid, caprylic acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachic acid, oleic acid, erucic acid, linoleic acid, linolenic acid, cyclohexanecarboxylic acid, phenylacetic acid, benzoic acid, neodecanoic acid, and the like.

[0169] In one embodiment, the oil soluble titanium compound may be present in the lubricating oil composition in an amount to provide from about 0 to about 3000 ppm by weight of titanium, or from 25 to about 1500 ppm by weight of titanium, or from about 35 ppm to about 500 ppm by weight of titanium, or from about 50 ppm to about 300 ppm.

[0170] Other optional additives Other additives may be selected to perform one or more functions required in a lubricating fluid. Additionally, one of the additives mentioned may be multifunctional and may provide functions in addition to or other than those described herein.

[0171] The lubricating oil composition according to the present disclosure may optionally contain other performance additives. The other performance additives may be in addition to the specified additives of the present disclosure and / or may include one or more of metal deactivators, viscosity index improvers, detergents, ashless TBN boosters, friction modifiers, antiwear agents, corrosion inhibitors, rust inhibitors, dispersants, dispersant viscosity index improvers, extreme pressure agents, antioxidants, foam suppressants, demulsifiers, emulsifiers, pour point depressants, seal swell agents, and mixtures thereof. Typically, a fully formulated lubricating oil will contain one or more of these performance additives.

[0172] Suitable metal deactivators may include derivatives of benzotriazole (typically tolyltriazole), dimercaptothiadiazole derivatives, 1,2,4-triazole, benzimidazole, 2-alkyldithiobenzimidazole, or 2-alkyldithiobenzothiazole; foam suppressors including copolymers of ethyl acrylate and 2-ethylhexyl acrylate and optionally vinyl acetate; demulsifiers including trialkyl phosphates, polyethylene glycol, polyethylene oxide, polypropylene oxide, and (ethylene oxide-propylene oxide) polymers; pour point depressants including esters of maleic anhydride-styrene, polymethacrylates, polyacrylates, or polyacrylamides.

[0173] Suitable suds suppressors include silicon-based compounds such as siloxanes.

[0174] Suitable pour point depressants may include polymethyl methacrylate or mixtures thereof. The pour point depressant may be present in an amount sufficient to provide from about 0 wt. % to about 1 wt. %, from about 0.01 wt. % to about 0.5 wt. %, or from about 0.02 wt. % to about 0.04 wt. %, based on the final weight of the lubricating oil composition.

[0175] A suitable rust inhibitor can be a single compound or a mixture of compounds that have the property of inhibiting corrosion of ferrous metal surfaces. Non-limiting examples of rust inhibitors useful herein include oil-soluble high molecular weight organic acids such as 2-ethylhexanoic acid, lauric acid, myristic acid, palmitic acid, oleic acid, linoleic acid, linolenic acid, behenic acid, and cerotic acid, as well as oil-soluble polycarboxylic acids including dimer and trimer acids such as those produced from tall oil fatty acids, oleic acid, and linoleic acid. Other suitable corrosion inhibitors include long chain alpha, omega-dicarboxylic acids in the molecular weight range of about 600 to about 3000, and alkenyl succinic acids in which the alkenyl group contains about 10 or more carbon atoms, such as tetrapropenyl succinic acid, tetradecenyl succinic acid, and hexadecenyl succinic acid. Another useful type of acidic corrosion inhibitor is the half ester of an alkenyl succinic acid having about 8 to about 24 carbon atoms in the alkenyl group with an alcohol, such as a polyglycol. The corresponding half amides of such alkenyl succinic acids are also useful. Useful rust inhibitors are high molecular weight organic acids. In some embodiments, the engine oil does not contain a rust inhibitor.

[0176] When present, the rust inhibitor may be used in an amount sufficient to provide from about 0 wt. % to about 5 wt. %, from about 0.01 wt. % to about 3 wt. %, from about 0.1 wt. % to about 2 wt. %, based on the final weight of the lubricating oil composition.

[0177] Generally speaking, a suitable crankcase lubricant may contain additive components in the ranges listed in the table below.

[0178] [Table 2]

[0179] The percentages of each component above represent the weight percent of each component based on the weight of the final lubricant composition, with the remainder of the lubricant composition consisting of one or more base oils.

[0180] The additives used in formulating the compositions described herein may be blended into the base oil individually or in various partial combinations, however, it may be preferred to use an additive concentrate (i.e., additives plus a diluent such as a hydrocarbon solvent) and blend all of the components simultaneously. EXAMPLES

[0181] The following examples illustrate, but do not limit, the methods and compositions of the present disclosure. Other suitable modifications and adaptations of the variety of conditions and parameters normally encountered in the art and obvious to those skilled in the art are within the spirit and scope of the present disclosure. All patents and publications cited herein are hereby fully incorporated by reference in their entirety.

[0182] Each of the lubricating oil compositions contained a major amount of base oil and a base conventional dispersant inhibitor (DI) package. The DI package contained conventional amounts of dispersants, antiwear additives, antioxidants, friction modifiers, antifoam agents, process oils, viscosity modifiers, and pour point depressants, as provided in Table 3 below. The majority of the base oils were a mixture of Group II and Group III base oils. The components that were modified are specified in the example tables and discussion below. All values ​​listed are stated as weight percent of the component in the lubricating oil composition (i.e., active stock plus diluent oil, if any) unless otherwise specified.

[0183] [Table 3]

[0184] The lubricating oil compositions were tested according to the Sequence VIII engine test. The Sequence VIII test method (ASTM D6709) covers the evaluation of both single and multi-viscosity grade automotive engine oils intended for use in spark-ignition gasoline engines. The test procedure is performed using a 0.7L carbureted spark-ignition Cooperative Lubrication Research (CLR) oil test engine (also referred to in this test method as the Sequence VIII test engine) running on unleaded fuel. The oil is evaluated for its ability to protect the engine and oil from degradation under high temperature and severe operating conditions. The engine runs continuously at 3150 rpm using unleaded gasoline for 40 hours, during which the lubricant temperature is raised to 143°C using an external lubricant heater. This test method is used to evaluate automotive engine oils for engine protection against bearing weight loss and to evaluate the retention of grade capability of multi-viscosity grade oils.

[0185] [Table 4] a) Glycerol monooleate is an ester of a polyhydric alcohol prepared from glycerol and oleate. b) Dispersant 1 - Prepared from polyisobutylene having a number average molecular weight of about 1900 g / mol to 2200 g / mol. c) Dispersant 2 - A borated dispersant prepared from polyisobutylene having a number average molecular weight of about 1000 g / mol to about 1500 g / mol. d) Dispersant 3 - A borated dispersant prepared from polyisobutylene having a number average molecular weight of about 1000 g / mol to about 1500 g / mol.

[0186] The data from Table 4 are plotted in the graph of Figure 1. The data in Table 4 show that there is improved bearing weight loss for lubricating oil compositions containing a ratio of weight percent glycerol monooleate to weight percent boron from the dispersant less than 40. This is evident from the lower bearing weight loss for Inventive Examples IE1-IE6 when compared to the values ​​for Comparative Examples CE1-CE2.

[0187] The data in Table 4 also show that there is an improvement in corrosion resistance for lubricating oil compositions formulated with a ratio of weight percent glycerol to weight percent boron from total dispersant less than 40 and an amount of glycerol monooleate less than 0.40 wt%. This is evident from the lower bearing weight loss for Inventive Examples IE1-IE6 when compared to the values ​​for Comparative Examples CE1 and CE2.

[0188] Additionally, the data in Table 4 shows that there is an improvement in corrosion resistance for lubricating oil compositions formulated with a ratio of wt% glycerol to wt% boron from total dispersant less than 40 and amounts (wt%) of boron from total dispersant greater than 0.0040 wt%. This is evident from the lower bearing weight loss of Inventive Examples IE1-IE6 when compared to the values ​​for Comparative Examples CE1 and CE2.

[0189] Other embodiments of the present disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the embodiments disclosed herein. As used throughout the specification and claims, "a" and / or "an" and / or "the" can refer to one or more than one. Unless otherwise indicated, all numbers expressing quantities, proportions, percentages, or other numerical values ​​should be understood in all instances as being modified by the term "about". Accordingly, unless indicated to the contrary, the numerical parameters set forth in the specification and claims are approximations that may vary depending on the desired properties sought to be obtained by the present disclosure. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should be construed at least in light of the number of reported significant digits and by applying ordinary rounding techniques.

[0190] It is understood that each component, compound, substituent, or parameter disclosed herein should be construed as disclosed for use alone or in combination with one or more of any and all other components, compounds, substituents, or parameters disclosed herein.

[0191] It is further to be understood that each range disclosed herein should be construed as a disclosure of each specific value within the disclosed range having the same number of significant digits. Thus, for example, a range of 1 to 4 should be construed as an explicit disclosure of the values ​​1, 2, 3, and 4, and any range of such values.

[0192] It is further understood that each lower limit of each range disclosed herein should be interpreted as being disclosed in combination with each upper limit of each range and each specific value within each range disclosed herein for the same component, compound, substituent, or parameter. Thus, the present disclosure should be interpreted as a disclosure of all ranges derived by combining each lower limit of each range with each upper limit of each range or each specific value within each range, or by combining each upper limit of each range with each specific value within each range. That is, it is further understood that any range between the endpoint values ​​within the broad range is also contemplated herein. Thus, a range of 1 to 4 also means a range of 1 to 3, 1 to 2, 2 to 4, 2 to 3, etc.

[0193] Furthermore, a specific amount / value of a component, compound, substituent, or parameter disclosed in the description or examples should be construed as a disclosure of either a lower or upper limit of a range and therefore can be combined with any other lower or upper limit or specific amount / value in a range for the same component, compound, substituent, or parameter disclosed elsewhere in this application to form a range for that component, compound, substituent, or parameter.

Claims

1. 1. A lubricating oil composition comprising: greater than 50% by weight of a base oil of lubricating viscosity; less than 0.40 wt. %, based on the total weight of the lubricating oil composition, of one or more esters of a polyhydric alcohol; and an amount of one or more boron-containing dispersants; the ratio of the amount of said one or more esters of polyhydric alcohols provided in said lubricating oil composition in weight percent to the amount of boron provided by said one or more boron-containing dispersants in weight percent is less than 40, based on the total weight of the lubricating oil composition; A lubricating oil composition, wherein the lubricating oil composition has a bearing weight loss of less than 25 as measured by ASTM D6709.

2. 10. The lubricating oil composition of claim 1, wherein the amount of the one or more esters of polyhydric alcohols is less than 0.38 wt%, based on the total weight of the lubricating oil composition.

3. 10. The lubricating oil composition of claim 1, wherein the one or more esters of a polyhydric alcohol are prepared from a polyhydric alcohol and a carboxylic acid.

4. 2. The lubricating oil composition of claim 1, wherein the one or more esters of a polyhydric alcohol is a glycerol monooleate compound.

5. 10. The lubricating oil composition of claim 1, wherein the one or more boron-containing dispersants are present in an amount providing greater than 0.004 wt. % boron, based on a total weight of the lubricating oil composition.

6. 10. The lubricating oil composition of claim 1, wherein the one or more boron-containing dispersants are prepared from polyisobutenyl groups having a number average molecular weight of from about 500 g / mol to about 1800 g / mol as measured by gel permeation chromatography.

7. 10. The lubricating oil composition of claim 1, further comprising a second dispersant.

8. 8. The lubricating oil composition of claim 7, wherein the second dispersant is prepared from a polyisobutenyl group having a number average molecular weight of about 1500 g / mol to about 3000 g / mol as measured by gel permeation chromatography.

9. 8. The lubricating oil composition of claim 7, wherein the second dispersion fluid is non-boronated.

10. 8. The lubricating oil composition of claim 7, wherein the nitrogen concentration from all dispersants is greater than about 400 ppmw nitrogen, based on the total weight of the lubricating oil composition.

11. 10. The lubricating oil composition of claim 1, further comprising one or more metal-containing detergents, or one or more calcium-containing detergents present in an amount providing greater than 950 ppmw Ca based on the total weight of the lubricating oil composition.

12. 12. The lubricating oil composition of claim 11, wherein the one or more calcium-containing detergents are overbased calcium-containing detergents having a total base number of about 200 mg KOH / g or greater.

13. 13. The lubricating oil composition of claim 12, wherein the one or more calcium-containing detergents comprise an overbased calcium sulfonate detergent, an overbased calcium phenate detergent, an overbased calcium salicylate detergent, and mixtures thereof.

14. 12. The lubricating oil composition of claim 11, wherein the one or more calcium-containing detergents comprise a low-based or neutral calcium-containing detergent having a total base number of less than 175 mg KOH / g.

15. 15. The lubricating oil composition of claim 14, wherein the low based or neutral calcium-containing detergent comprises a calcium sulfonate detergent, a calcium phenate detergent, a calcium salicylate detergent, and mixtures thereof.

16. 15. The lubricating oil composition of claim 14, wherein the low based or neutral calcium-containing detergent is present in an amount from greater than 5 ppmw Ca to about 500 ppmw Ca, based on a total weight of the lubricating oil composition.

17. 10. The lubricating oil composition of claim 1, further comprising a zinc dialkyldithiophosphate.

18. 10. The lubricating oil composition of claim 1, wherein the lubricating oil composition has a bearing weight loss of less than 25 as measured by ASTM D6709.

19. 13. A method for improving bearing weight loss of a lubricating oil in an engine, said method comprising adding to said engine the lubricating oil composition of claim 1.

20. 20. The method of claim 19, wherein the amount of the one or more esters of polyhydric alcohols is less than 0.38 wt. %, based on the total weight of the lubricating oil composition.

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