Engine oil with improved viscosity performance

Abstract

To provide lubricants with polymers effective to provide improved viscometric properties when using heavier base oils.SOLUTION: A multi-grade lubricating oil including a (meth)acrylate polymer with at least two distinct molecular weight arms and a blend of heavier and lighter base oils with increased amounts of the heavier base oil to achieve SAE grade performance. The compositions achieve SAE certifications as lower CCS viscosities at target kinematic viscosities for multi-grade oils.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This disclosure relates to a lubricant having a polymer that is effective in providing improved viscosity properties when using heavier base oils. [Background technology]

[0002] Lubricants intended for use as motor oil (commonly also called engine oil or crankcase oil) in gasoline or diesel vehicle engines typically consist of a base oil or a blend of base oils of lubricating viscosity and one or more additives to meet specific performance requirements. The viscosity profile of motor oil is most commonly defined by the Society of Automotive Engineers (SAE) J300 standard. This well-known standard classifies the performance of motor oil into various viscosity grades, with grade levels associated with the letter "W" intended for use at lower temperatures, and grade levels without "W" intended for use at higher temperatures. Multigrade oils meet the requirements of both low-temperature and higher-temperature performance standards. Viscosity grade classification is primarily based on CCS viscosity (cold cranking simulator) in accordance with ASTM D5292, cold pumping viscosity on a mini rotational viscometer (MRV) in accordance with ASTM D4684, kinematic viscosity at 100°C in accordance with ASTM D445, and / or high-temperature high-shear viscosity (HTHS) in accordance with ASTM D4683, D4741, and / or D5471.

[0003] For example, the conventional nomenclature for multi-grade viscosity engine oils is the "xW-y" classification, where the "x" value is 0, 5, 10, 15, 20, or 35, and the "y" value is typically 16, 20, 30, 40, 50, or 60. As an example, a 0W-20 multi-grade oil must meet the CCS, MRV, and kinematic viscosity requirements of a 0W viscosity grade oil, as well as the kinematic viscosity of a 20 viscosity grade oil. Modern automotive industry standards impose increasingly stringent requirements on the composition and performance of such oils, often leaving little room for flexibility in lubricant formulations. As lubricant manufacturers strive to meet not only SAE standards but also automotive standards, the challenge becomes achieving all required performance and automotive industry standards cost-effectively and simultaneously.

[0004] Generally, trim ingredients and other base oil blends may be used in engine lubricants to help achieve the required specifications. Typically, so-called lighter base oils, or lower viscosity base oils, are often preferred to achieve the desired specifications in multigrade oils. However, the use of such lighter base oils may be undesirable for a variety of reasons, including cost and the impact such lighter trim ingredients have on the balance of the fluid properties of the final fluid. [Overview of the project]

[0005] In one aspect of this disclosure, a multigrade lubricant composition is described that achieves SAE J300 certification for at least 0W-16, 0W-20, and 5W-20 grade oils with an increased amount of heavier base oil. In an approach or embodiment, the multigrade lubricant composition of this specification comprises a base oil blend comprising at least one lighter base oil having a KV100 of 4.5 cSt or less and at least one heavier base oil having a KV100 of 5.5 cSt or more. The base oil blend comprises at least about 20 weight percent of the at least one heavier base oil based on the total weight of the base oils in the blend. The composition further comprises about 1 weight percent or less of a (meth)acrylate copolymer based on a polymer solid having a hydrocarbyl group in the monomer ester portion, wherein the (meth)acrylate copolymer has, as polymerization monomer units, (i) a (meth)acrylate monomer unit having a hydrocarbyl group with an intermediate molecular weight of about 500 to about 700 in the monomer ester portion, and (ii) a (meth)acrylate monomer unit having a hydrocarbyl group with a molecular weight of about 6,000 to about 10,000 in the monomer ester portion. In an optional approach or embodiment, the (meth)acrylate copolymer further comprises, as polymerization monomer units, (iii) a (meth)acrylate monomer unit having a hydrocarbyl group with a low molecular weight of about 400 or less in the monomer ester portion.

[0006] In other approaches or embodiments, the multigrade lubricant compositions of the previous paragraph may be combined with one or more optional features or embodiments. These optional embodiments include the multigrade lubricant composition exhibiting a kinematic viscosity of 9.3 mm² / sec or less at 100°C (up to approximately 6.6 mm² / sec in some approaches) and a CCS of approximately 6200 mPas or less at -35°C or approximately 6600 mPas or less at -30°C (and down to 4300 mPas at -35°C or down to 4600 mPas at -30°C in some approaches), and / or at least one lighter base oil being a blend of two or more base oils, each having a KV100 of 4.5 cSt or less, and / or the blend of two or more lighter base oils being selected from API Group II base oils, API Group III base oils, API Group IV base oils, or a combination thereof, or at least one heavier base oil being selected from API Group III base oils, API Group IV base oils, or a combination thereof, and / or the ratio of lighter base oils to heavier base oils being 1.The molecular weight is 55 or less, and / or the base oil blend contains at least about 40 weight percent of heavier base oil, and / or the base oil blend contains about 40 to about 60 weight percent of heavier base oil, and / or the (meth)acrylate copolymer has a number average molecular weight of about 140,000 or more, and / or the (meth)acrylate copolymer has a number average molecular weight of 500,000 or less, and / or the (meth)acrylate copolymer has a number average molecular weight of 500,000 or less as polymerization monomer units, (ii i) The monomer ester portion further comprises (meth)acrylate monomer units having a hydrocarbyl group of about 400 or less in molecular weight, and / or the (meth)acrylate copolymer comprises a (meth)acrylate monomer having a hydrocarbyl moiety of 12 to 16 carbon atoms and a (meth)acrylate monomer having a hydrocarbyl moiety derived from a macromonomer of an alkene or alkadiene including ethylene, propylene, butene, butadiene, isoprene, or a combination thereof, and having a molecular weight of 10,000 or less. - is derived from and / or the molecular weight ratio of high molecular weight hydrocarbyl groups to low molecular weight hydrocarbyl groups in the (meth)acrylate monomer ester portion of the copolymer is about 1.5:1 to about 50:1 and / or further comprises a hydrocarbyl-substituted succinamide dispersant or succinimide dispersant and / or the multigrade lubricant composition contains about 1 to about 8 weight percent (or about 1 to 6 weight percent) of a hydrocarbyl-substituted succinamide dispersant or succinimide dispersant and / or the hydrocarbyl-substituted succinamide dispersant or succinimide dispersant is derived from a hydrocarbyl-substituted acylating agent reacted with a polyalkylene polyamine, and the hydrocarbyl substituent of the succinamide dispersant or succinimide dispersant is a linear or branched hydrocarbyl group having a number average molecular weight of about 250 to about 5,000 when measured by GPC using polystyrene as the calibration standard and / or the polyalkylene polyamine has the following formula. [ka] In the formula, each R and R' is independently a divalent C1-C6 alkylene linker, and each R1 and R2 is independently hydrogen, a C1-C6 alkyl group, or together with the nitrogen atom to which they are bonded, optionally fused with one or more aromatic or non-aromatic rings to form a 5-membered or 6-membered ring, and n is an integer from 0 to 8; and / or the polyalkylene polyamine may be selected from the group consisting of a mixture of polyethylene polyamines having an average of 5 to 7 nitrogen atoms, triethylenetetramine, tetraethylenepentaamine, and combinations thereof.

[0007] In other embodiments, methods for formulating multigrade lubricant compositions that achieve SAE J300 certification for at least 0W-16, 0W-20, and 5W-20 grade oils with increased amounts of heavier base oils are described herein. In some approaches or embodiments, this method involves using and / or blending a certain amount of base oil having about 1 weight percent or less of a (meth)acrylate copolymer based on a polymer solid to form a multigrade lubricant composition that exhibits a kinematic viscosity of 9.3 mm² / sec or less at 100°C (down to about 6.6 mm² / sec in some approaches) and a CCS of about 6200 mPas or less at -35°C or about 6600 mPas or less at -30°C (and down to 4300 mPas at -35°C or down to 4600 mPas at -30°C in some approaches), and in some approaches also exhibit a kinematic viscosity up to about 1 kV unit lower at the target CCS viscosity compared to a multigrade lubricant composition that does not contain a (meth)acrylate copolymer at the same target CCS viscosity. The base oil of this method comprises a blend of at least one lighter base oil having a KV100 of 4.5 cSt or less and at least one heavier base oil having a KV100 of 5.5 cSt or more, wherein the base oil blend has at least about 20 weight percent of at least one heavier base oil based on the total weight of the base oils in the blend. The (meth)acrylate copolymer of this method comprises, as polymerization monomer units, (i) a (meth)acrylate monomer unit having a hydrocarbyl group of an intermediate molecular weight of about 500 to about 700 in the monomer ester portion, and (ii) a (meth)acrylate monomer unit having a hydrocarbyl group of a molecular weight of 6,000 to 10,000 in the monomer ester portion. In an optional approach or embodiment of this method, the (meth)acrylate copolymer further comprises, as polymerization monomer units, (iii) a (meth)acrylate monomer unit having a hydrocarbyl group of a low molecular weight of about 400 or less in the monomer ester portion.

[0008] The methods or uses described in the preceding paragraph may be combined with any optional features and embodiments. These optional features or embodiments include any combination of any of the following: the base oil blend includes a ratio of lighter base oil to heavier base oil of about 1.55 or less; the base oil blend includes about 40 to about 60 weight percent of heavier base oil; and / or the multigrade lubricating oil composition includes about 1 to about 8 weight percent of a succinamide dispersant or succinimide dispersant substituted with hydrocarbyl; as well as any combination of any optional features or embodiments described in this disclosure.

[0009] To clarify the meaning of specific terms used herein, the following definitions are provided.

[0010] The terms “oil composition,” “lubrication composition,” “lubricating oil composition,” “lubricating oil,” “lubricant composition,” “lubricating composition,” “completely formulated lubricant composition,” “lubricant,” “crankcase oil,” “crankcase lubricant,” “engine oil,” “engine lubricant,” “motor oil,” and “motor lubricant” are considered synonymous, fully interchangeable technical terms referring to the final lubrication product containing a small amount of additive composition in addition to a major amount of base oil.

[0011] 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 synonymous, fully interchangeable technical terms referring to a portion of a lubricating oil composition excluding the main amount of base oil raw material mixture. An additive package may or may not contain viscosity index improvers or pour point depressants.

[0012] "Lighter base oil" refers to a lubricating base oil with a kinematic viscosity (KV100) of 4.5 cSt or less, while "heavier base oil" refers to a lubricating base oil with a kinematic viscosity (KV100) of 5.5 cSt or more.

[0013] The term “overbasic” refers to metal salts such as sulfonates, carboxylates, salicylates, and / or phenates in which the amount of metal present exceeds the stoichiometric amount. Such salts can have a conversion level greater than 100% (i.e., they can contain more than 100% of the theoretical amount of metal required to convert an acid to its “standard,” “neutral” salt). The expression “metallic ratio,” often abbreviated as MR, is used to indicate the ratio of the total stoichiometric equivalents of metal in an overbasic salt to the stoichiometric equivalents of metal in a neutral salt, according to known chemical reactivity and stoichiometry. The metallic ratio is 1 for standard or neutral salts, but for overbasic salts, the MR is greater than 1. These are commonly called overbasic, highly basic, or ultrabasic salts and may be salts of organic sulfur acids, carboxylic acids, salicylates, and / or phenols.

[0014] As used herein, the terms “hydrocarbyl,” “hydrocarbyl substituent,” or “hydrocarbyl group” are used in their ordinary sense as is well known to those skilled in the art. Specifically, they refer to groups having carbon atoms directly bonded to the rest of the molecule and having primarily hydrocarbon properties. Each hydrocarbyl group is independently selected from hydrocarbon substituents, the substituted hydrocarbon substituents containing one or more of the following: halo, hydroxyl, alkoxy, mercapto, nitro, nitroso, amino, pyridyl, furyl, imidazolyl, oxygen, and nitrogen, with no more than two non-hydrocarbon substituents for every 10 carbon atoms in the hydrocarbyl group.

[0015] As used herein, the term "hydrocarbylene substituent" or "hydrocarbylene group" is used in its ordinary meaning well known to those skilled in the art. Specifically, it refers to a group that is directly bonded to the remainder of the molecule by carbon atoms at two locations in the molecule and mainly has hydrocarbon characteristics. Each hydrocarbylene group is independently selected from divalent hydrocarbon substituents, and the substituted divalent hydrocarbon substituents are halo groups, alkyl groups, aryl groups, alkylaryl groups, arylalkyl groups, hydroxyl groups, alkoxy groups, mercapto groups, nitro groups, nitroso groups, amino groups, pyridyl groups, furyl groups, imidazolyl groups, oxygen, and nitrogen, and there are two or fewer non-hydrocarbon substituents per ten carbon atoms in the hydrocarbylene group.

[0016] As used herein, the term "weight percent" means the percentage that the described component represents with respect to the total weight of the composition, unless otherwise specifically stated.

[0017] The terms "soluble", "oil-soluble", or "dispersible" as used herein may indicate that a compound or additive is soluble, soluble, miscible, or can be suspended in oil in any proportion, but not necessarily so. However, the foregoing terms mean that they are soluble, suspension, soluble, or stably dispersible in oil to such an extent that they can exert their intended effects, for example, in the environment where oil is produced. Further, if necessary, higher levels of incorporation of a particular additive may be possible by additionally incorporating other additives.

[0018] The term "TBN" as employed herein is used to indicate the total base number in units of mgKOH / g when measured by the method of ASTM D2896 or ASTM D4739 or DIN 51639-1.

[0019] The term "alkyl" as employed herein refers to straight-chain, branched-chain, cyclic, and / or substituted saturated chain moieties of from about 1 to about 100 carbon atoms.

[0020] As used herein, the term "alkenyl" refers to straight-chain, branched-chain, cyclic, and / or substituted unsaturated chain moieties having from about 3 to about 10 carbon atoms.

[0021] As used herein, the term "aryl" refers to monocyclic 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.

[0022] The lubricants, component combinations, 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 vehicle, light-duty diesel, medium-speed diesel, or marine engines. The internal combustion engine may be a diesel fuel engine, gasoline fuel engine, natural gas fuel engine, biofuel engine, mixed diesel / biofuel - fuel engine, mixed gasoline / biofuel - fuel engine, alcohol fuel engine, mixed gasoline / alcohol fuel engine, compressed natural gas (CNG) fuel 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 an electric or battery power source. An engine configured in this way is generally known as a hybrid engine. The internal combustion engine may be a two-stroke, four-stroke, or rotary engine. Suitable internal combustion engines include marine diesel engines (e.g., inland vessels), aircraft piston engines, low-load diesel engines, as well as motorcycle, automobile, locomotive, and truck engines.

[0023] An internal combustion engine may contain one or more components from 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 contain 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 containing aluminum and another component mixed or reacting at a microscopic or near-microscopic level, regardless of its detailed structure. This includes any conventional alloy containing metals other than aluminum, as well as composite or alloy-like structures having non-metallic elements or compounds such as ceramic-like materials.

[0024] Lubricating oil compositions for internal combustion engines may be suitable for any engine lubricant, regardless of their sulfur, phosphorus, or sulfated ash (ASTM D-874) content. The sulfur content of the engine oil lubricant may be about 1% by weight or less, or about 0.8% by weight or less, or about 0.5% by weight or less, or about 0.3% by weight or less, or about 0.2% by weight or less. In one embodiment, the sulfur content may be in the range of about 0.001% by weight to about 0.5% by weight, or about 0.01% by weight to about 0.3% by weight. The phosphorus content may be about 0.2% by weight or less, or about 0.1% by weight or less, or about 0.085% by weight or less, or about 0.08% by weight or less, or even about 0.06% by weight or less, about 0.055% by weight or less, or about 0.05% by weight 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 may 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 may 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 may be about 0.4% by weight or less, the phosphorus content may be about 0.08% by weight or less, and the sulfated ash content may be about 1% by weight or less. In yet another embodiment, the sulfur content may be about 0.3% by weight or less, the phosphorus content may be about 0.05% by weight or less, and the sulfated ash content may be about 0.8% by weight or less.

[0025] In one embodiment, the lubricating oil composition is engine oil, and the lubricating oil composition may have (i) a sulfur content of about 0.5% by weight or less, (ii) a phosphorus content of about 0.1% by weight or less, and (iii) a sulfated ash content of about 1.5% by weight or less.

[0026] 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 marine-suitable engine oil (e.g., more than about 40 TBN for marine-suitable engine oil).

[0027] In some embodiments, the lubricating oil composition is suitable for use in engines powered by low-sulfur fuels, such as fuels containing about 1 to about 5% sulfur. Highway vehicle fuel contains about 15 ppm of sulfur (or about 0.0015% sulfur).

[0028] Low-speed diesel typically refers to marine engines, medium-speed diesel typically refers to locomotives, and high-speed diesel typically refers to highway vehicles. The lubricating oil composition may be suitable for one or all of these types.

[0029] Furthermore, the lubricants described herein meet one or more industry specification requirements such as ILSAC GF-3, GF-4, 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, C1, C2, C3, C4, C5, E4 / E6 / E7 / E9, Euro 5 / 6, JASO DL-1, Low SAPS, Mid SAPS, or Dexos1 (trademark), Dexos2 (trademark), MB-Approval 229.1, 229.3, 229.5, 229.51 / 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-01 FE, Longlife-04, Longlife-12 FE, Longlife-14 FE+, Longlife-17 FE+, 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.03.5004, STJLR.It may be suitable for meeting the original equipment manufacturer's specifications such as 03.5005, STJLR.03.5006, STJLR.03.5007, STJLR.51.5122, or past or future PCMO or HDD specifications not described 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.

[0030] Other hardware may not be suitable for use with the disclosed lubricants. “Functional fluid” is a term encompassing a wide range of fluids, including but not limited to tractor working fluids, power transmission fluids including automatic transmission fluids, continuously variable transmission fluids and manual transmission fluids, working fluids including tractor working fluids, some gear oils, power steering fluids, fluids used in wind turbines and compressors, some industrial fluids, and fluids associated with components of power transmission systems. It should be noted that within each of these fluids, such as automatic transmission fluids, there are various different types of fluids for various transmissions with different designs that require fluids with significantly different functional characteristics. This is in contrast to the term “lubricating fluid,” which is not used for power generation or transmission.

[0031] For example, with respect to the working fluids of a tractor, these fluids are general-purpose fluids used for all lubrication applications in the tractor, except for lubricating the engine. These lubrication applications may include lubrication of the gearbox, power take-off and clutch, rear axle, reduction gear, wet brakes, and hydraulic accessories.

[0032] If the functional fluid is an automatic transmission fluid, the automatic transmission fluid must have sufficient friction for the clutch plates to transmit power. However, the coefficient of friction of a fluid tends to decrease due to the effect of temperature as the fluid heats up during operation. It is important for the working fluid or automatic transmission fluid of a tractor to maintain a high coefficient of friction at high temperatures, otherwise the braking system or automatic transmission may fail. This is not the function of engine oil.

[0033] Tractor fluids, such as Super Tractor Universal Oil (STUO) or Universal Tractor Transmission Oil (UTTO), may combine the performance of engine oil with the performance of transmissions, differentials, final drive planetary gears, wet brakes, and hydraulics. Many of the additives used to formulate UTTO or STUO fluids are functionally similar, but can have harmful effects if not properly incorporated. For example, some anti-wear and extreme-pressure additives used in engine oils can be extremely corrosive to the copper components of 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, stringent manufacturer requirements, regardless of functionality, tractor, or lubrication.

[0034] This disclosure provides novel lubricant blends formulated for use as automotive crankcase lubricants. This disclosure provides novel lubricant blends formulated for use as 2T and / or 4T motorcycle crankcase lubricants. Embodiments of this disclosure may provide lubricants suitable for crankcase applications and having improved properties of air inclusion, alcohol fuel compatibility, oxidation prevention, wear resistance, biofuel compatibility, bubble reduction, friction reduction, fuel efficiency, pre-ignition prevention, rust inhibition, sludge and / or soot dispersion, piston cleaning, deposit formation, and water resistance.

[0035] The engine oils of this 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, individually with the base oil (or a mixture of both). The fully formulated engine oil may exhibit improved performance characteristics based on the added additives and their respective proportions.

[0036] Where used herein, polymerizable reactants and / or monomers that form polymers or copolymers are described. Unless otherwise indicated, polymer generally refers to a polymer of one type of monomer, and copolymer refers to a polymer of two or more types of monomers. Reactants or monomers generally refer to compounds in the reaction mixture before polymerization, and monomer units or (alternatively) repeating units refer to reactants or monomers polymerized within a polymer chain. The various monomers herein are often polymerized randomly within a backbone as monomer units or repeating units. Where a discussion refers to reactants or monomers, it also means the obtained monomer units or repeating units derived therefrom in a polymer or copolymer. Similarly, where a discussion refers to monomer units or repeating units, it also means the reactant mixture or monomer mixture used to form a polymer or copolymer with the relevant monomers or repeating units therein.

[0037] The molecular weight of any embodiment of this specification may be determined using a gel permeation chromatography (GPC) instrument or similar instrument available from Waters, and data processed with Waters Empower Software or similar software. The GPC instrument may be equipped with a Waters Separations Module and a Waters refractive index detector (or similar optional equipment). Operating conditions for the GPC may include a guard column with a column temperature of approximately 40°C and four Agilent PLgel columns (300 × 7.5 mm in length, 5 μm in particle size, and pore size 100–10000 Å). Unstabilized HPLC-grade tetrahydrofuran (THF) may be used as the solvent at a flow rate of 1.0 mL / min. The GPC instrument may be calibrated using commercially available polystyrene (PS) standards with a narrow molecular weight distribution in the range of 500–380,000 g / mol. Calibration curves for samples with a mass of less than 500 g / mol may be extrapolated. The sample and PS standard can be dissolved in THF and prepared at a concentration of 0.1–0.5% by weight, and can be used without filtration. GPC measurement is also described in US5,266,223, which is incorporated herein by reference. For additional molecular weight distribution information, see, for example, WWYau, JJKirkland and DDBly, “Modern Size Exclusion Liquid Chromatography”, John Wiley and Sons, New York, 1979, which is also incorporated herein by reference.

[0038] Further details and benefits of this disclosure are partially described below and / or may be acquired through the implementation of this disclosure. These details and benefits may be realized and achieved through the elements and combinations specifically indicated in the attached claims. It should be understood that both the general description above and the detailed description below are illustrative and descriptive only and do not limit the claimed disclosure. [Brief explanation of the drawing]

[0039] [Figure 1] This is a viscosity map of potential multigrade lubricant compositions containing different polymers. [Modes for carrying out the invention]

[0040] Engine or crankcase lubricant compositions are generally used in vehicles, including those with spark-ignition or compression-ignition engines, to provide friction reduction and other benefits. Such engines may be used in automobiles, trucks, motorcycles, and / or trains, to name a few applications, and may be powered by fuels including, but not limited to, gasoline, diesel, alcohol, biofuels, and compressed natural gas. These engines may include hybrid electric engines, which include both an internal combustion engine and an electric or battery power source, and / or advanced hybrid or internal combustion engines, which include an automatic engine shut-off function when the vehicle is stationary.

[0041] This disclosure describes unique multigrade lubricant compositions that meet SAE J300 certification for at least 0W-16, 0W-20, and 5W-20 formulations, including more than one heavier base oil, which is surprisingly a base oil having a KV100 of 5.5 cSt or higher. In the approach, the multigrade lubricant compositions herein have at least about 20 wt percent, at least about 40 wt percent, about 20 to about 60 wt percent, or about 40 to about 60 wt percent of at least one heavier base oil, based on the total weight of base oils in the lubricant. However, the ability to use more than one such heavier base oil and still achieve SAE certification for at least 0W-16, 0W-20, and 5W-20 multigrade oils is possible in the embodiments herein when the multigrade lubricant composition also includes a certain (meth)acrylate copolymer based on the polymer solid, which has at least two, in some approaches three, distinct molecular weight pendant hydrocarbyl groups on the ester portion of the monomer units of the copolymer.

[0042] As will be further discussed below, these unique copolymers have, for example, at least two distinct polymerized (meth)acrylate monomer units, and in some approaches, three distinct polymerized (meth)acrylate monomer units selected from (1) a (meth)acrylate monomer unit having a pendant hydrocarbyl group with a low molecular weight of about 400 or less in its monomer ester portion, (2) a (meth)acrylate monomer unit having an intermediate molecular weight of pendant hydrocarbyl group of 500 to 700 in its monomer ester portion, and (3) a (meth)acrylate monomer unit having a high molecular weight of pendant hydrocarbyl group of 6,000 to 10,000 in its monomer ester portion. Surprisingly, when this unique copolymer is included in the multigrade lubricant composition herein at a concentration of about 1 weight percent or less, a base oil blend with a larger amount of heavier base oil can be used, and the final fluid can still achieve SAE certification for at least 0W-16, 0W-20, and / or 5W-20 oils. This result is surprising, as it was not expected that a fluid capable of meeting the lower KV100 and CCS targets of such SAE certification could be achieved by using a larger amount of heavier base oil compared to a lighter base oil. Such formulations offer greater flexibility to lubricant compositions that still achieve SAE certification. In some approaches, proprietary copolymers have the structure of formula I below, [ka] In the formula, R is methyl or hydrogen, R1 forms part of a low molecular weight pendant hydrocarbyl group, R2 forms part of an intermediate molecular weight pendant hydrocarbyl group, and / or R3 forms part of a high molecular weight pendant hydrocarbyl group, and a, b, and c are integers representing the number of repeating units of each monomer type in the copolymer to achieve the desired copolymer molecular weight (the a, b, and c units are preferably polymerized randomly within the copolymer). The copolymer contains at least monomer groups associated with integers b and c, and some approaches include all three of a, b, and c.

[0043] Poly(meth)acrylate copolymer In one embodiment, the fluid of this specification comprises a small amount (about 1 weight percent or less based on the polymer solid) of a selected (meth)acrylate copolymer having a blend of two or more distinct molecular weight pendant arms (in some cases, three distinct arms), such as low molecular weight, intermediate molecular weight, and / or high molecular weight pendant hydrocarbyl groups, in the ester portion of the (meth)acrylate monomer units that form in the copolymer. Suitable monomers or reactants for forming this copolymer for the unique fluids of this specification include a blend of at least two distinct (meth)acrylate monomers or reactants (and in some approaches, three distinct (meth)acrylate monomers or reactants) selected from: (1) (meth)acrylate monomers having hydrocarbyl groups with a low weight-average molecular weight of about 400 or less in the ester portion; (2) (meth)acrylate monomers having hydrocarbyl groups with an intermediate weight-average molecular weight of about 500 to about 700 in the ester portion; and (3) (meth)acrylate monomers having hydrocarbyl groups with a high weight-average molecular weight of about 6,000 to about 10,000 in the ester portion. As used herein, "(meth)acrylate" refers to both methacrylate and / or acrylate monomers or monomer units (or mixtures). The molecular weight of the hydrocarbyl group of the monomer ester includes the hydrocarbyl chain as well as the ester oxygen, but does not include the carbonyl group.

[0044] Typically, the formed or obtained (meth)acrylate copolymers have a monomer amount effective to achieve a number-average molecular weight of about 140,000 or more, and in some cases, about 250,000 or less, for example, about 150,000 to about 240,000 copolymers, and the polydispersity index is about 2.8 or less, or about 2.6 or less, and in other approaches, in the range of about 1.8 to about 2.6. In yet another approach, the copolymers herein have a molecular weight ratio between a higher molecular weight arm and a lower molecular weight arm of about 10:1 to about 50:1, in another approach, about 11:1 to about 30:1, and in yet another approach, about 12:1 to about 25:1. In other cases, the copolymers herein have a molecular weight ratio between a higher molecular weight arm and a lower molecular weight arm of about 1.5:1 to about 25:1, and in other approaches, about 1.5:1 to about 16:1.

[0045] Turning to the copolymer details, one approach is that the (meth)acrylate copolymers herein include reaction products in the form of linear random copolymers of selected amounts of low, intermediate, and / or high molecular weight pendant hydrocarbyl (meth)acrylate monomers. These monomers and monomer units, further described below, contain both linear and / or branched hydrocarbyl groups in their respective ester chains, forming comb-like copolymers having at least two distinct molecular weight arms, and possibly three distinct molecular weight arms, in some embodiments.

[0046] In embodiments or approaches, low molecular weight hydrocarbyl (meth)acrylate units are derived from alkyl (meth)acrylate monomers having an alkyl group having a total carbon chain length of a monomer ester moiety (including any branching) of 6 to 20 carbons and preferably 12 to 16 carbons. Exemplary low molecular weight hydrocarbyl (meth)acrylate monomers may also be lauryl (meth)acrylates, which may comprise a blend of (meth)acrylate monomers or monomer units having alkyl chain lengths in the range of C12 to C16, specifically alkyl chains of 12, 14, and 16 carbons, of which C12 alkyl (meth)acrylates constitute the majority.

[0047] In other embodiments or approaches, intermediate molecular weight hydrocarbyl (meth)acrylate units are derived from hydrocarbyl (meth)acrylate monomers having a hydrocarbyl group or total hydrocarbyl ester length (including any branching) and having a weight-average molecular weight of at least about 500 to a maximum of about 700. These intermediate molecular weight chains can be derived from macromonomers of polymer alcohols esterified with (meth)acrylic acid. The macromonomers may also be derived from alkenes or alkadienes, including ethylene, propylene, butene, butadiene, isoprene, or combinations thereof, and have a molecular weight of about 700 or less, such as about 500 to about 700.

[0048] In further embodiments or approaches, high molecular weight hydrocarbyl (meth)acrylate units are derived from hydrocarbyl (meth)acrylate monomers having a hydrocarbyl group or total hydrocarbyl ester length (including any branching) with a weight-average molecular weight of at least about 6,000 and up to about 10,000. These high molecular weight chains can be derived from macromonomers of polymer alcohols esterified with (meth)acrylic acid. The macromonomers may be derived from alkenes or alkadienes, including ethylene, propylene, butene, butadiene, isoprene, or combinations thereof, with molecular weights of about 500 to about 10,000, or less than about 10,000, such as about 6,000 to about 10,000.

[0049] In optional embodiments, the poly(meth)acrylate copolymers herein may also include other optional monomers and monomer units, such as hydroxyalkyl(meth)acrylates and / or various dispersant monomers and monomer units. The poly(meth)acrylate copolymers herein may optionally be functionalized with one or more dispersant monomers or monomer units. In one approach, the dispersant monomer or monomer unit may be a nitrogen-containing monomer or a unit thereof. Such monomers may impart dispersant functional groups to the polymer if used. In some approaches, the nitrogen-containing monomer may be a (meth)acrylic monomer such as methacrylate or methacrylamide. In some approaches, the bonding of the nitrogen-containing moiety to the acrylic moiety may be via a nitrogen atom or alternatively an oxygen atom, in which case the nitrogen of the monomer would be located elsewhere in the monomer. The nitrogen-containing monomer may be other than (meth)acrylic monomers such as vinyl-substituted nitrogen heterocyclic monomers and vinyl-substituted amines. Examples of nitrogen-containing monomers include those in US6,331,603. Other suitable dispersant monomers include, but are not limited to, dialkylaminoalkyl acrylates, dialkylaminoalkyl (meth)acrylates, dialkylaminoalkyl acrylamides, dialkylaminoalkyl methacrylamides, N-tertiary alkylacrylamides, and N-tertiary alkyl methacrylamides, and the alkyl or aminoalkyl group may independently contain 1 to 8 carbon atoms. For example, the dispersant monomer may be dimethylaminoethyl (meth)acrylate. Nitrogen-containing monomers may be, for example, t-butylacrylamide, dimethylaminopropyl (meth)acrylamide, dimethylaminoethyl methacrylamide, N-vinylpyrrolidone, N-vinylimidazole, or N-vinylcaprolactam.It may also be a (meth)acrylamide based on any of the aromatic amines disclosed in WO2005 / 087821, including 4-phenylazoaniline, 4-aminodiphenylamine, 2-aminobenzimidazole, 3-nitroaniline, 4-(4-nitrophenylazo)aniline, N-(4-amino-5-methoxy-2-methylphenyl)-benzamide, N-(4-amino-2,5-dimethoxyphenyl)-benzamide, N-(4-amino-2,5-diethoxyphenyl)-benzamide, N-(4-amino-phenyl)-benzamide, and 4-amino-2-hydroxybenzoic acid.

[0050] The (meth)acrylate copolymers of this disclosure are typically synthesized to have a number-average molecular weight of about 140,000 or more, and, by other approaches, about 250,000 or less. Preferred ranges of number-average molecular weight include about 140,000 to about 250,000, and, by other approaches, about 150,000 to about 240,000. Such copolymers of this specification typically have a polydispersity index in the range of about 1 to about 3, and, by other approaches, about 1.2 to about 3, and, by yet another approach, about 1.2 to about 2, and, by yet another approach, about 2 to about 3.

[0051] (Meth)acrylate copolymers may also be prepared by any suitable conventional or controlled free radical polymerization technique. Examples include conventional free radical polymerization (FRP), reversible addition-cleavage chain transfer (RAFT), atom transfer radial polymerization (ATRP), and other controlled types of polymerization known in the art. Polymerization procedures are known to those skilled in the art and include, for example, the use of common polymerization initiators (Vazo(trademark)67(2,2'-azobis(2-methylbutyronitrile, etc.)), chain transfer agents (dodecyl mercaptan, etc.) when using conventional FRP, or RAFT agents (4-cyano-4-[(dodecylsulfanylthiocarbonyl)sulfanyl]pentanoic acid, etc.) when using RAFT polymerization. Other initiators, chain transfer agents, RAFT agents, ATRP catalysts, and initiator systems may be used as known in the art, depending on the selected polymerization method and as required for the particular application.

[0052] lubricating oil composition The (meth)acrylate copolymers described herein may be combined with one or more further optional additives to produce lubricating oil compositions that meet SAE certification for at least 0W-16, 0W-20, and / or 5W-20 oils, in a major amount of a base oil blend or a base oil blend of lubricating viscosity (described below). In the approach, the lubricating oil composition comprises a base oil blend of about 50% by weight or more, about 60% by weight or more, about 70% by weight or more, or about 80% by weight or more to about 95% by weight or less, about 90% by weight or less, or about 85% by weight or less, such blends of which are further discussed below.

[0053] In one approach, the lubricating oil composition herein may be based on a polymer solid and may contain an amount of the above-mentioned (meth)acrylate polymer in the range of about 0.20% to about 1% by weight relative to the total weight of the lubricating composition; in another approach, the amount is in the range of at least about 0.2% by weight, at least about 0.25% by weight, at least about 0.3% by weight, at least about 0.4% by weight, at least about 0.5% to about 1% by weight or less, about 0.9% by weight or less, about 0.8% by weight or less, about 0.7% by weight or less, about 0.6% by weight or less, or about 0.5% by weight or less.

[0054] Base Oil Blends: The base oils used in the lubricating oil compositions herein may be selected from any of the base oils in Groups I through V, as specified in the American Petroleum Institute (API) Base Oil Interchangeability Guidelines. The five groups of base oils are as follows: [Table 1]

[0055] Groups I, II, and III are mineral oil process raw materials. Group IV base oils contain true synthetic molecular species produced by the polymerization of olefinic 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, but may also be naturally occurring oils such as vegetable oils. Group III base oils are derived from mineral oils, but it should be noted that the harsh processing these fluids undergo makes their physical properties very similar to some true synthetics such as PAOs. Therefore, oils derived from Group III base oils are sometimes referred to as synthetic fluids in the industry. Group II+ may also include high viscosity index Group II.

[0056] The base oil blend used in the disclosed lubricating oil composition may be mineral oil, animal oil, vegetable oil, synthetic oil, synthetic oil blend, or a mixture thereof. Suitable oils may be derived from hydrocracking, hydrogenation, hydrofinishing, unrefined, refined and refined oils, as well as mixtures thereof.

[0057] Lighter and heavier base oils: In any embodiment or approach herein, the base oil is a blend of one or more lighter base oils and one or more heavier base oils. Preferably, the blend comprises at least one lighter base oil having a KV100 of 4.5 cSt or less and at least one heavier base oil having a KV100 of 5.5 cSt or more. More preferably, the base oil blend comprises at least about 20 weight percent or at least about 40 weight percent of at least one heavier base oil, based on the total weight of the base oils in the blend. In other approaches, the base oil blend comprises at least about 20 weight percent, at least about 30 weight percent, at least about 40 weight percent, at least about 42 weight percent, at least about 44 weight percent, at least about 46 weight percent, or at least about 48 weight percent to about 60 weight percent or less, about 58 weight percent or less, about 56 weight percent or less, about 54 weight percent or less, about 52 weight percent or less, or about 50 weight percent or less of heavier base oils, based on the total weight of the base oils in the composition.

[0058] The heavier base oils used in the blends herein may be API Group III or API Group IV base oils having a KV100 of 5.5 cSt or higher, and in embodiments, a KV100 of 5.5 to 10 cSt, 5.5 to 8 cSt, or 5.5 to 6.5 cSt. In some embodiments, the heavier base oil is a Group IV base oil from polyalphaolefins having a viscosity index of about 120 or higher, or about 120 to about 200.

[0059] The lighter base oils used in the blends herein may be API Group II, Group III, or API Group IV base oils having a KV100 of 4.5 cSt or less, and in embodiments, having a KV100 of 3.0–4.5 cSt, 3.5–4.5 cSt, 3.8–4.5 cSt, or 4.0–4.5 cSt. In some embodiments, the lighter base oil is a blend of both Group III oils and Group IV base oils from polyalphaolefins, and may have a viscosity index of about 120 or more, or about 120–about 200. In other embodiments, the lighter base oil is one or more Group III base oils.

[0060] Unrefined oils are derived from natural, mineral, or synthetic sources that undergo little to no refining. Refined oils are similar to unrefined oils, except that they have been processed in one or more refining steps that may result in an improvement in one or more properties. Examples of preferred refining techniques include solvent extraction, secondary distillation, acid or base extraction, filtration, and osmosis. Oils refined to edible quality may or may not be useful. Edible oils are sometimes also called white oils. In some embodiments, lubricating oil compositions do not contain edible oils or white oils.

[0061] Refined oil is also known as recycled oil or reprocessed oil. These oils are obtained in the same way as refined oil using the same or similar processes. Often, these oils are further processed by techniques that target the removal of spent additives and oil cracking products.

[0062] Mineral oils may include oils obtained by drilling, or oils obtained 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 lubricants such as liquid petroleum, paraffinic, naphthenic, or paraffin-naphthenic mixed types of solvent-treated or acid-treated mineral lubricants. Such oils may be partially or completely hydrogenated as needed. Oils derived from coal or shale may also be useful.

[0063] Useful synthetic lubricants may include hydrocarbon oils such as polymerized, oligomerized, or internally polymerized olefins (e.g., polybutylene, polypropylene, propylene isobutylene copolymers); trimers or oligomers of poly(1-hexene), poly(1-octene), 1-decene, e.g., poly(1-decene) (such materials are often called α-olefins), and mixtures thereof; alkylbenzenes (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, as well as their derivatives, analogs, and homologs, or mixtures thereof. Polyalphaolefins are typically hydrogenated materials.

[0064] Other synthetic lubricants include polyol esters, diesters, liquid esters of phosphorus-containing acids (e.g., tricresyl phosphate, trioctyl phosphate, diethyl ester of decanephosphonic acid), or polymeric tetrahydrofurans. Synthetic oils may also be produced by the Fischer-Tropsch reaction and are typically hydrogenated isomerized Fischer-Tropsch hydrocarbons or waxes. In one embodiment, the oil may be prepared by other gas-to-liquid oil procedures as well as the Fischer-Tropsch gas-to-liquid synthesis procedure.

[0065] The main amount of base oil in the lubricating composition may be selected from the group consisting of Group I, Group II, Group III, Group IV, Group V, and two or more combinations thereof, and the main amount of base oil is other than base oil resulting from the provision of additive components or viscosity index improvers in the composition. In another embodiment, the main amount of base oil in the lubricating composition may be selected from the group consisting of Group II, Group III, Group IV, Group V, and two or more combinations thereof, and the main amount of base oil is other than base oil resulting from the provision of additive components or viscosity index improvers in the composition.

[0066] The amount of lubricating viscosity oil present may be the remainder after subtracting from 100% by weight the total amount of performance additives, including viscosity index improvers and / or pour point depressants and / or other surface treatment additives. For example, the amount of lubricating viscosity oil that may be present in the final fluid may be a major amount such as over 50% by weight, over 60% by weight, over 70% by weight, over 80% by weight, over 85% by weight, or over 90% by weight.

[0067] Optional additives: The engine oil or lubricating oil compositions described herein may also include several optional additives as necessary to meet performance standards. These optional additives are described in the following paragraphs.

[0068] Dispersants: Lubricating oil compositions may optionally contain one or more dispersants or mixtures thereof. Dispersants are often known as ashless dispersants because they do not contain metals that form ash before being mixed into the lubricating oil composition and do not typically contribute to any ash when added to the lubricant. Ashless dispersants are characterized by polar groups being bonded to relatively high molecular weight hydrocarbon chains. Typical ashless dispersants include N-substituted long-chain alkenyl succinimides. An example of an N-substituted long-chain alkenyl succinimide is polyisobutylene succinimide, in which the number-average molecular weight of the polyisobutylene substituent is in the range of about 350 to about 50,000, or about 5,000, or about 3,000, as measured by GPC. Succinimide dispersants and their preparations are disclosed, for example, in U.S. Patent No. 7,897,696 or U.S. Patent No. 4,234,435. The alkenyl substituents may be prepared from polymerizable monomers containing about 2 to about 16 carbon atoms, or about 2 to about 8 carbon atoms, or about 2 to about 6 carbon atoms. The succinimide dispersant is typically an imide formed from a polyamine, which is typically poly(ethyleneamine).

[0069] Preferred amines are selected from polyamines and hydroxyamines. Examples of polyamines that may be used include, but are not limited to, higher homologues such as diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA), and pentaethylaminehexamine (PEHA).

[0070] A suitable heavy polyamine is a polyalkylene-polyamine mixture containing a small amount of lower polyamine oligomers such as TEPA and PEHA (pentaethylenehexamine), but mainly containing six or more nitrogen atoms, two or more primary amines per molecule, and oligomers having a broader branching than conventional polyamine mixtures. The heavy polyamine preferably contains a polyamine oligomer containing seven or more nitrogen atoms per molecule and two or more primary amines per molecule. The heavy polyamine contains more than 28% by weight (e.g., more than 32% by weight) of total nitrogen and 120 to 160 grams of primary amine groups per equivalent weight.

[0071] In some approaches, preferred polyamines are commonly known as PAMs and contain a mixture of ethyleneamines, with TEPA and pentaethylenehexamine (PEHA) being the main components of the polyamine, usually less than 80%.

[0072] Typically, PAMs contain 8.7–8.9 milliequivalents of primary amine per gram (115–112 gram equivalents per primary amine equivalent) and a total nitrogen content of approximately 33–34% by weight. Heavier cuts of PAM oligomers, which are substantially TEPA-free and contain very small amounts of PEHA, but mainly contain oligomers with six or more nitrogen atoms and broader branching, may produce dispersants with improved dispersibility.

[0073] In one embodiment, the disclosure further includes at least one polyisobutylene succinimide dispersant having a number average molecular weight in the range of about 350 to about 50,000, or about 5,000, or about 3,000, as determined by GPC. The polyisobutylene succinimide may be used alone or in combination with other dispersants.

[0074] In some embodiments, polyisobutylene, if present, may have a terminal double bond content of more than 50 mol%, more than 60 mol%, more than 70 mol%, more than 80 mol%, or more than 90 mol%. Such PIBs are also called highly reactive PIBs ("HR-PIBs"). HR-PIBs having a number-average molecular weight in the range of about 800 to about 5000 as determined by GPC are suitable for use in embodiments of this disclosure. Conventional PIBs typically have 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%.

[0075] When determined by GPC, HR-PIBs having a number-average molecular weight in the range of about 900 to about 3000 may be preferred. Such HR-PIBs are commercially available or can be synthesized by polymerization of isobutene in the presence of a non-chlorinating catalyst such as boron trichloride, 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 used in the aforementioned thermal ene reaction, HR-PIBs may result in a higher conversion rate during the reaction and the formation of less precipitate due to increased reactivity. A preferred method is described in U.S. Patent No. 7,897,696.

[0076] In one embodiment, the disclosure further comprises at least one dispersant derived from polyisobutylene succinic anhydride ("PIBSA"). PIBSA may have an average succinic acid moiety of about 1.0 to about 2.0 per polymer.

[0077] The activity percentage of alkenyl or alkyl succinic anhydride can be determined using chromatographic techniques. This method is described in columns 5 and 6 of U.S. Patent No. 5,334,321.

[0078] The conversion rate of polyolefins is calculated from the activity percentage using the formulas in columns 5 and 6 of U.S. Patent No. 5,334,321.

[0079] Unless otherwise specified, all percentages are weight percentages, and all molecular weights are number-average molecular weights determined by gel permeation chromatography (GPC) using commercially available polystyrene standards (with a number-average molecular weight of 180 to approximately 18,000 as a calibration standard).

[0080] In one embodiment, the dispersant may be derived from polyalphaolefin (PAO) succinic anhydride. In another embodiment, the dispersant may be derived from olefin maleic anhydride copolymer. For example, the dispersant may be described as polyPIBSA. In one embodiment, the dispersant may be derived from an anhydride grafted onto an ethylene-propylene copolymer.

[0081] A suitable class of nitrogen-containing dispersants may be derived from olefin copolymers (OCPs), more specifically from ethylene-propylene dispersants that can be grafted with maleic anhydride. A more complete list of nitrogen-containing compounds that can be reacted with functionalized OCPs is described and / or commercially available in U.S. Patents Nos. 7,485,603, 7,786,057, 7,253,231, 6,107,257, and 5,075,383.

[0082] The hydrocarbyl moiety of the hydrocarbyl-dicarboxylic acid or anhydride may, alternatively, be derived from ethylene-alphaolefin copolymers. These copolymers consist of multiple ethylene units and multiple C3-C3 groups. 10 Contains alpha-olefin units. C3~C 10The alpha-olefin units may also contain propylene units. The ethylene-alpha-olefin copolymer typically has a number-average molecular weight of less than 5,000 g / mol when measured by GPC using polystyrene as the calibration standard, or the number-average molecular weight of the copolymer may be less than 4,000 g / mol, or less than 3,500 g / mol, or less than 3,000 g / mol, or less than 2,500 g / mol, or less than 2,000 g / mol, or less than 1,500 g / mol, or less than 1,000 g / mol. In some embodiments, the number-average molecular weight of the copolymer may be between 800 and 3,000 g / mol.

[0083] The ethylene content of the ethylene-alphaolefin copolymer may be less than 80 mol%, less than 70 mol%, less than 65 mol%, less than 60 mol%, less than 55 mol%, less than 50 mol%, less than 45 mol%, or less than 40 mol%. The ethylene content of the copolymer may be at least 10 mol% and less than 80 mol%, or at least 20 mol% and less than 70 mol%, or at least 30 mol% and less than 65 mol%, or at least 40 mol% and less than 60 mol%.

[0084] C3-C of ethylene-alphaolefin copolymer 10 The alpha-olefin content may be at least 20 mol%, or at least 30 mol%, or at least 35 mol%, or at least 40 mol%, or at least 45 mol%, or at least 50 mol%, or at least 55 mol%, or at least 60 mol%.

[0085] In some embodiments, at least 70 mol% of the molecules of the ethylene-alpha olefin copolymer may have an unsaturated group, and at least 70 mol% of the unsaturated groups may be located at a terminal vinylidene group or a trisubstituted isomer of a terminal vinylidene group, or at least 75 mol% of the copolymer may terminate with a terminal vinylidene group or a trisubstituted isomer of a terminal vinylidene group, or at least 80 mol% of the copolymer may terminate with a terminal vinylidene group or a trisubstituted isomer of a terminal vinylidene group, or at least 80 mol% of the copolymer may terminate with a terminal vinylidene group or a trisubstituted isomer of a terminal vinylidene group, or at least 85 mol% of the copolymer may terminate with a terminal vinylidene group or a trisubstituted isomer of a terminal vinylidene group, or at least 90 mol% of the copolymer may terminate with a terminal vinylidene group or a trisubstituted isomer of a terminal vinylidene group, or at least 95 mol% of the copolymer may terminate with a terminal vinylidene group or a trisubstituted isomer of a terminal vinylidene group. The terminal vinylidene and trisubstituted isomers of the terminal vinylidene of the copolymer have one or more of the following structural formulas (A) to (C), [Chemical Formula] In the formula, R represents a C1-C8 alkyl group, and " [Chemical Formula] " indicates that the bond is bonded to the remaining part of the copolymer.

[0086] The ethylene-alpha olefin copolymer of the dispersant 13 may have an average ethylene unit run length (n C2 ) of less than 2.8 when determined by 13C NMR spectroscopy, and also satisfies the relationship shown by the following formula, [Equation] In the formula, EEE = (x C2 ) 3 , EEA = 2(x C2 ) 2 (1 - x C2), AEA=x C2 (1-x C2 ) 2 , and x C2 teeth, 1 The average ethylene unit run length n is the mole fraction of ethylene incorporated into the polymer, as measured by 1H-NMR spectroscopy, where E represents ethylene units and A represents alpha-olefin units. The copolymer may have an average ethylene unit run length of less than 2.6, less than 2.4, less than 2.2, or less than 2. c2 The relationship shown in the following equation may also be satisfied: In the formula, n C2、実際 <n C2、統計 That is the case.

[0087] The crossover temperature of the ethylene-alphaolefin copolymer may be -20°C or below, or -25°C or below, or -30°C or below, or -35°C or below, or -40°C or below. The copolymer may have a polydispersity index of 4 or below, or 3 or below, or 2 or below. Less than 20% of the unit triads in the copolymer may be ethylene-ethylene-ethylene triads, or less than 10% of the unit triads in the copolymer may be ethylene-ethylene-ethylene triads, or less than 5% of the unit triads in the copolymer may be ethylene-ethylene-ethylene triads. Further details of the ethylene-alphaolefin copolymer and dispersants prepared therefrom can be found in PCT / US18 / 37116 filed with the U.S. Receiving Office, the disclosure thereof is incorporated herein by reference in its entirety.

[0088] One class of suitable dispersants may also 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 detail by U.S. Patent No. 3,634,515.

[0089] A suitable class of dispersants may also be high molecular weight esters or semi-esteramides. The suitable dispersants may also be post-treated by reacting with any of the various agents by conventional methods. These include boron, urea, thiourea, dimercaptothiadiazole, carbon disulfide, aldehydes, ketones, carboxylic acids, hydrocarbon-substituted succinic anhydride, maleic anhydride, nitriles, epoxides, carbonates, cyclic carbonate hindered phenol esters, and phosphorus compounds. US7,645,726, US7,214,649, and US8,048,831 are incorporated herein by reference in their entirety.

[0090] In addition to carbonate and boric acid post-treatment, each compound may be post-treated or further post-treated by 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 inorganic phosphoric acid or anhydride (e.g., U.S. Patents No. 3,403,102 and 4,648,980); organophosphorus compounds (e.g., U.S. Patent No. 3,502,677); phosphorus pentasulfide; boron compounds as already mentioned above (e.g., U.S. Patents No. 3,178,663 and 4,652,387); carboxylic acids, polycarboxylic acids, anhydrides and / or acid halides (e.g., U.S. Patent No. 3,708,52 U.S. Patent Nos. 2 and 4,948,386); Epoxy polyepoxides or thioepoxides (e.g., U.S. Patents 3,859,318 and 5,026,495); Aldehydes or ketones (e.g., U.S. Patent No. 3,458,530); Carbon disulfide (e.g., U.S. Patent No. 3,256,185); Glycidol (e.g., U.S. Patent No. 4,617,137); Urea, thiourea, or guanidine (e.g., U.S. Patent Nos. 3,3 U.S. Patent No. 12,619, U.S. Patent No. 3,865,813, and British Patent No. GB1,065,595); Organic sulfonic acids (e.g., U.S. Patent No. 3,189,544 and British Patent No. GB2,140,811); Alkenyl cyanides (e.g., U.S. Patent No. 3,278,550 and U.S. Patent No. 3,366,569); Diketenes (e.g., U.S. Patent No. 3,546,243); Diisocyanates (e.g., U.S. Patent No. 3,573,205); A Lucansultones (e.g., U.S. Patent No. 3,749,695); 1,3-dicarbonyl compounds (e.g., U.S. Patent No. 4,579,675); alkoxylated alcohols or phenolic sulfates (e.g., U.S. Patent No. 3,954,639); cyclic lactones (e.g., U.S. Patents No. 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. Patents 4,612,132, 4,647,390, 4,648,886, and 4,670,170); nitrogen-containing carboxylic acids (e.g., U.S. Patent 4,971,598 and UK Patent GB2,140,811); hydroxy-protected chlorodicarbonyloxy compounds (e.g., U.S. Patent 4,614,522), lactams, thiolactams, thiolactones, or ditractones (e.g., U.S. (U.S. Patent Nos. 4,614,603 and 4,666,460), cyclic carbonates or thiocarbonates, linear monocarbonates or polycarbonates, or chloroformates (e.g., U.S. Patents Nos. 4,612,132, 4,647,390, 4,646,860, and 4,670,170); nitrogen-containing carboxylic acids (e.g., U.S. Patent No. 4,971,598 and UK Patent No. 2,440,811); hydroxy-protected chlorodicarbonyloxy compounds (e.g., U.S. Patent No. 4,614,522); Talams, thiolactams, thiolactones, or dithiolactones (e.g., U.S. Patent Nos. 4,614,603 and 4,666,460); cyclic carbamates, cyclic thiocarbamates, or cyclic dithiocarbamates (e.g., U.S. Patent Nos. 4,663,062 and 4,666,459); hydroxyaliphatic carboxylic acids (e.g., U.S. Patents Nos. 4,482,464, 4,521,318 and 4,713,189); oxidizing agents (e.g., U.S. Patent No. 4,379,064); combinations of phosphorus pentasulfide and polyalkylene polyamines (e.g., U.S. Patent No. 3,185,647); combinations of carboxylic acids, aldehydes, or ketones with sulfur or sulfur chloride (e.g., U.S. Patents No. 3,390,086 and 3,470,098); combinations of hydrazine and carbon disulfide (e.g., U.S. Patent No. 3,519,564); combinations of aldehydes and phenols (e.g., U.S. Patents No. 3,649,229, 5,030,249 and 5,039,307); combinations of aldehydes and O-diesters of dithiophosphate (e.g., U.S. Patent No. 3,865,740);Combinations of hydroxyaliphatic carboxylic acid and boric acid (e.g., U.S. Patent No. 4,554,086); combinations of hydroxyaliphatic carboxylic acid, then formaldehyde and phenol (e.g., U.S. Patent No. 4,636,322); combinations of hydroxyaliphatic carboxylic acid and then aliphatic dicarboxylic acid (e.g., U.S. Patent No. 4,663,064); combinations of formaldehyde and phenol, then glycolic acid (e.g., U.S. Patent No. 4,699,724); combinations of hydroxyaliphatic carboxylic acid or oxalic acid and then diisocyanate (e.g., U.S. Patent No. 4,713,191); inorganic acids or anhydrides of phosphorus, also This includes treatments using combinations of partial or total sulfur analogs with boron compounds (e.g., U.S. Patent No. 4,857,214); combinations of organic diacids, then unsaturated fatty acids, then nitroso aromatic amines, optionally boron compounds, then glycolating agents (e.g., U.S. Patent No. 4,973,412); combinations of aldehydes and triazoles (e.g., U.S. Patent No. 4,963,278); combinations of aldehydes and triazoles, then boron compounds (e.g., U.S. Patent No. 4,981,492); and combinations of cyclic lactones and boron compounds (e.g., U.S. Patents No. 4,963,275 and 4,971,711). The above patents are incorporated herein by reference in their entirety.

[0091] A suitable dispersant may have a TBN of approximately 5 to 30 TBN when measured in a dispersant sample containing approximately 50% diluted oil, or approximately 10 to 65 mg KOH / g on an oil-free basis. TBN is measured by the method of ASTM D2896.

[0092] In further embodiments, the optional dispersant additive may be a hydrocarbyl-substituted succinamide or succinimide dispersant. In this approach, the hydrocarbyl-substituted succinamide or succinimide dispersant may be derived from a hydrocarbyl-substituted acylating agent reacted with a polyalkylene polyamine, where the hydrocarbyl substituent of the succinamide or succinimide dispersant is a linear or branched hydrocarbyl group having a number-average molecular weight of about 250 to about 5,000 when measured by GPC using polystyrene as the calibration standard.

[0093] In some approaches, the polyalkylene polyamine used to form the dispersant has the following formula: [ka] In the formula, each R and R' is independently a divalent C1-C6 alkylene linker, each R1 and R2 independently forms a 5-membered or 6-membered ring by being either hydrogen, a C1-C6 alkyl group, or a nitrogen atom to which they are bonded, and optionally fused with one or more aromatic or non-aromatic rings, where n is an integer from 0 to 8. Another approach is to select polyalkylene polyamines from the group consisting of mixtures of polyethylene polyamines having an average of 5-7 nitrogen atoms, triethylenetetramine, tetraethylenepentaamine, and combinations thereof.

[0094] If present, the dispersant 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. Other amounts of dispersant that may be used may be about 0.1% to about 15% by weight, or about 0.1% to about 10% by weight, about 0.1% to about 8% by weight, or about 1% to about 10% by weight, or about 1% to about 8% by weight, or 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.

[0095] Antioxidants: The lubricating oil compositions of this specification may optionally contain one or more antioxidants. Antioxidant compounds are known and include, for example, phenates, phenate sulfides, sulfurized olefins, phosphosulfur terpenes, sulfurized esters, aromatic amines, alkylated diphenylamines (e.g., nonyldiphenylamine, di-nonyldiphenylamine, octyldiphenylamine, dioctyldiphenylamine), phenyl-alpha-naphthylamines, alkylated phenyl-alpha-naphthylamines, hindered non-aromatic amines, phenols, hindered phenols, oil-soluble molybdenum compounds, polymeric antioxidants, or mixtures thereof. Antioxidant compounds may be used alone or in combination.

[0096] Hindered phenol antioxidants may contain secondary butyl groups and / or tertiary butyl groups as sterically hindering groups. The phenol group may be further substituted with a hydrocarbyl group and / or a crosslinking group bonded 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, for example, Irganox® L-135 available from BASF, or an addition product derived from 2,6-di-tert-butylphenol and an alkyl acrylate, where the alkyl group may contain about 1 to about 18 carbon atoms, or about 2 to about 12 carbon atoms, or about 2 to about 8 carbon atoms, or about 2 to about 6 carbon atoms, or about 4 carbon atoms. Another commercially available hindered phenol antioxidant may be an ester, and may include Ethanox® 4716 available from Albemarle Corporation.

[0097] Useful antioxidants may include diarylamines and high molecular weight phenols. In some embodiments, the lubricating oil composition may contain a mixture of diarylamines and high molecular weight phenols, so that each antioxidant may be present in an amount sufficient to provide up to about 5% by weight, based on the final weight of the lubricating oil composition. In some embodiments, the antioxidant may be a mixture of about 0.3 to about 1.5% by weight of diarylamine and about 0.4 to about 2.5% by weight of high molecular weight phenol, based on the final weight of the lubricating oil composition.

[0098] 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 may be Diels-Alder adducts of dienes such as 1,3-butadiene and unsaturated esters such as butyl acrylate.

[0099] Another class of sulfurized olefins includes sulfurized fatty acids and their esters. Fatty acids are often obtained from vegetable or animal oils and typically contain 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, fatty acids are obtained from lard oil, tall oil, peanut oil, soybean oil, cottonseed oil, sunflower seed oil, or mixtures thereof. Fatty acids and / or esters may be mixed with olefins such as α-olefins.

[0100] In another alternative embodiment, the antioxidant composition also contains a molybdenum-containing antioxidant in addition to the phenolic and / or amine antioxidants described above. When a combination of these three antioxidants is used, the preferred ratio of phenol, amine, and molybdenum content is (0-2):(0-2):(0-1).

[0101] One or more antioxidants may be present in the lubricating oil composition in an amount ranging from about 0% to about 20% by weight, or from about 0.1% to about 10% by weight, or from about 1% to about 5% by weight.

[0102] Anti-wear agents: The lubricating oil compositions of this specification may optionally contain one or more anti-wear agents. Examples of suitable anti-wear agents include, but are not limited to, metal thiophosphates, metal dialkyldithiophosphates, phosphate esters or salts thereof; phosphate esters, phosphites, phosphorus-containing carboxylic acid esters, ethers, or amides; sulfurized olefins; thiocarbamate-containing compounds including thiocarbamate esters, alkylene-linked thiocarbamates, and bis(S-alkyldithiocarbamyl) disulfide; and mixtures thereof. A suitable anti-wear agent may be molybdenum dithiocarbamate. Phosphorus-containing anti-wear agents are described in detail in European Patent No. 612839. The metal in the dialkyldithiophosphate salt may be alkali metals, alkaline earth metals, aluminum, lead, tin, molybdenum, manganese, nickel, copper, titanium, or zinc. A useful anti-wear agent may be zinc dialkyldithiophosphate.

[0103] Further examples of suitable abrasion resistant agents include titanium compounds, tartarates, tartrimides, oil-soluble amine salts of phosphorus compounds, sulfurized olefins, phosphites (e.g., dibutylphosphite), phosphonates, thiocarbamate-containing compounds, such as thiocarbamate esters, thiocarbamate amides, thiocarbamate ethers, alkylene-bonded thiocarbamates, and bis(S-alkyldithiocarbamyl) disulfides. Tartarates or tartrimides may contain alkyl-ester groups, and the total number of carbon atoms on the alkyl group may be at least 8. In one embodiment, the abrasion resistant agent may also contain citrate.

[0104] The anti-wear agent may be present in the range of about 0% to about 15% by weight, or about 0.01% to about 10% by weight, or about 0.05% to about 5% by weight, or about 0.1% to about 3% by weight of the lubricating oil composition.

[0105] Boron-containing compounds: The lubricating oil compositions herein may optionally contain one or more boron-containing compounds. Examples of boron-containing compounds include borate esters, boro-fatty amines, boro-epoxides, boro-detergents, and boro-dispersants such as succinimide boro-dispersants, as disclosed in U.S. Patent No. 5,883,057. If present, boron-containing compounds may be used in amounts sufficient to provide up to about 8% by weight, about 0.01% to about 7% by weight, about 0.05% to about 5% by weight, or about 0.1% to about 3% by weight of the lubricating oil composition.

[0106] Detergents: The lubricating oil composition may optionally further contain one or more neutral, low-basic, or over-basic detergents, and mixtures thereof. Suitable detergent substrates include phenates, sulfur-containing phenates, sulfonates, calixalates, salixalates, salicylates, carboxylic acids, phosphoric acids, mono and / or dithiophosphates, alkylphenols, sulfur-linked alkylphenol compounds, or methylene-crosslinked phenols. Suitable detergents and methods for preparing them are described in detail in numerous patent publications, including US7,732,390 and the references cited therein.

[0107] The detergent substrate is not limited, but may be based with an alkali metal or alkaline earth metal such as calcium, magnesium, potassium, sodium, lithium, barium, or a mixture thereof. In some embodiments, the detergent is barium-free. In some embodiments, the detergent may contain trace amounts of other metals such as magnesium or calcium in amounts such as 50 ppm or less, 40 ppm or less, 30 ppm or less, 20 ppm or less, or 10 ppm or less. Suitable detergents may include alkali metal or alkaline earth metal salts of petroleum sulfonic acid and long-chain mono- or dialkylaryl sulfonic acid whose aryl group is benzyl, tolyl, or xylyl. Examples of suitable detergents include, but are not limited to, calcium phenate, calcium sulfur-containing phenate, calcium sulfonate, calcium calixalate, calcium salixalate, calcium salicylate, calcium carboxylic acid, calcium phosphate, calcium mono and / or dithiophosphate, calcium alkylphenol, calcium sulfur-linked alkylphenol compounds, calcium methylene crosslinked phenol, magnesium phenate, magnesium sulfur-containing phenate, magnesium sulfonate, magnesium calixalate, magnesium salixalate, magnesium salicylate, magnesium carboxylic acid, magnesium phosphate, magnesium mono and / or dithiophosphate, magnesium alkylphenol, magnesium sulfur-linked alkylphenol compounds, magnesium methylene crosslinked phenol, sodium phenate, sodium sulfur-containing phenate, sodium sulfonate, sodium calixalate, sodium salixalate, sodium salicylate, sodium carboxylic acid, sodium phosphate, sodium mono and / or dithiophosphate, sodium alkylphenol, sodium sulfur-linked alkylphenol compounds, or sodium methylene crosslinked phenol.

[0108] Overbasic detergent additives are well known in the art and may be alkali metal or alkaline earth metal overbasic detergent additives. 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, aliphatic-substituted carboxylic acid, or aliphatic-substituted phenol.

[0109] The term “overbasic” refers to metal salts such as sulfonates, carboxylates, and phenates in which the amount of metal present exceeds the stoichiometric amount. Such salts may have a conversion level greater than 100% (i.e., they may contain more than 100% of the theoretical amount of metal required to convert an acid to its “standard” or “neutral” salt). The expression “metallic ratio,” often abbreviated as MR, is used to indicate the ratio of the total stoichiometric equivalents of metal in an overbasic salt to the stoichiometric equivalents of metal in a neutral salt, according to known chemical reactivity and stoichiometry. The metallic ratio is 1 for standard or neutral salts, but for overbasic salts, the MR is greater than 1. These are commonly called overbasic, highly basic, or ultrabasic salts and may be salts of organic sulfur acids, carboxylic acids, or phenols.

[0110] The overbasic cleaning agent in the lubricating oil composition may have a total base number (TBN) of about 200 mg KOH / gram or more, or, as further examples, about 250 mg KOH / gram or more, or about 350 mg KOH / gram or more, or about 375 mg KOH / gram or more, or about 400 mg KOH / gram or more.

[0111] Suitable examples of overbasic detergents include, but are not limited to, overbasic calcium phenate, overbasic calcium sulfur-containing phenate, overbasic calcium sulfonate, overbasic calcium calixalate, overbasic calcium salixalate, overbasic calcium salicylate, overbasic calcium carboxylic acid, overbasic calcium phosphate, overbasic calcium mono and / or dithiophosphate, overbasic calcium alkylphenol, overbasic calcium sulfur-bonded alkylphenol compound, overbasic calcium methylene crosslinked phenol, overbasic magnesium phenate, overbasic magnesium sulfur-containing phenate, overbasic magnesium sulfonate, overbasic magnesium calixalate, overbasic magnesium salixalate, overbasic magnesium salicylate, overbasic magnesium carboxylic acid, overbasic magnesium phosphate, overbasic magnesium mono and / or dithiophosphate, overbasic magnesium alkylphenol, overbasic magnesium sulfur-bonded alkylphenol compound, or overbasic magnesium methylene crosslinked phenol.

[0112] Overbasic phenate calcium detergents, when measured according to the ASTM D-2896 method, have a total base number of at least about 150 mg KOH / g, at least about 225 mg KOH / g, at least about 225 mg KOH / g to about 400 mg KOH / g, at least about 225 mg KOH / g to about 350 mg KOH / g, or about 230 mg KOH / g to about 350 mg KOH / g. When such detergent compositions are formed with an inert diluent, e.g., process oil, usually mineral oil, the total base number reflects the basicity of the entire composition, including the diluent and any other materials that may be contained in the detergent composition (e.g., accelerators).

[0113] The overbasic cleaning agent may have a metal-to-substrate ratio ranging from 1.1:1, 2:1, 4:1, 5:1, 7:1, or 10:1. In some embodiments, the cleaning agent is effective in reducing or preventing rust in the engine. The cleaning agent may be present in amounts of about 0% to about 10% by weight, or about 0.1% to about 8% by weight, or about 1% to about 4% by weight, or more than about 4% to about 8% by weight.

[0114] Extreme pressure agents: The lubricating oil compositions of this specification may optionally contain one or more extreme pressure agents. Oil-soluble extreme pressure (EP) agents include sulfur and chlorosulfur-containing EP agents, chlorinated hydrocarbon EP agents, and phosphorus EP agents. Examples of such EP agents include chlorinated waxes; organic sulfides and polysulfides such as dibenzyl disulfide, bis(chlorobenzyl) disulfide, dibutyltetrasulfide, methyl sulfide esters of oleic acid, alkylphenol sulfides, dipentene sulfides, terpenes sulfides, and Diels-Alder sulfide adducts; phosphorus sulfide hydrocarbons such as reaction products of phosphorus sulfides with turpentine or methyl oleate; phosphorus esters such as dihydrocarbyl and trihydrocarbyl phosphates, e.g., dibutyl phosphite, diheptyl phosphite, dicyclohexyl phosphite, pentylphenyl phosphite; dipentylphenyl phosphite, tridecyl phosphite, distearyl phosphite, and polypropylene-substituted phenyl phosphates; metal thiocarbamates such as zinc dioctyl dithiocarbamate and barium heptylphenol dioate; amine salts of alkyl and dialkyl phosphates, e.g., amine salts of reaction products of dialkyldithiophosphate and propylene oxide; and mixtures thereof.

[0115] Friction modifiers: The lubricating oil compositions of this specification may optionally contain one or more friction modifiers. Suitable friction modifiers may include metal-containing and metal-free friction modifiers, and may include, but are not limited to, imidazolines, amides, amines, succinimides, alkoxylated amines, alkoxylated etheramines, amine oxides, amidoamines, nitriles, betaines, quaternary amines, imines, amine salts, aminoguanidines, alkanolamides, phosphonates, metal-containing compounds, glycerol esters, sulfurized fatty compounds and olefins, sunflower oil, other naturally occurring vegetable or animal oils, dicarboxylic acid esters, esters or partial esters of polyols with one or more aliphatic or aromatic carboxylic acids, and the like.

[0116] A suitable friction modifier may contain a hydrocarbyl group selected from linear, branched, or aromatic hydrocarbyl groups, or mixtures thereof, and may be saturated or unsaturated. The hydrocarbyl group may consist of a heteroatom such as carbon and hydrogen or sulfur or oxygen. The hydrocarbyl group may be in the range of 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 monoester, diester, or (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.

[0117] Other suitable friction modifiers may include organic, ashless (metal-free), and nitrogen-free organic friction modifiers. Such friction modifiers may include esters formed by reacting carboxylic acids and anhydrides with alkanols, and generally contain polar end groups (e.g., carboxyl or hydroxyl) covalently bonded to a lipophilic hydrocarbon chain. An example of an organic ashless nitrogen-free friction modifier is commonly known as glycerol monooleate (GMO), which may contain mono-, di-, and tri-esters of oleic acid. Other suitable friction modifiers are described in whole in U.S. Patent No. 6,723,685, which is incorporated herein by reference.

[0118] Amineral friction modifiers may contain amines or polyamines. Such compounds may have hydrocarbyl groups that are linear, saturated, unsaturated, or mixtures thereof, and may contain about 12 to about 25 carbon atoms. Further examples of suitable friction modifiers include alkoxylated amines and alkoxylated etheramines. Such compounds may have hydrocarbyl groups that are linear, saturated, unsaturated, or mixtures thereof. These may contain about 12 to about 25 carbon atoms. Examples include ethoxylated amines and ethoxylated etheramines.

[0119] Amines and amides may be used on their own or as adducts or reaction products with boron compounds such as boron oxide, boron halides, metaborates, boric acid, or mono-, di-, or tri-alkylborates. Other suitable friction modifiers are described in U.S. Patent No. 6,300,291, which is incorporated herein by reference in whole.

[0120] The friction modifier may optionally be present in a range such as approximately 0% to 10% by weight, or approximately 0.01% to 8% by weight, or approximately 0.1% to 4% by weight.

[0121] Molybdenum-containing components: The lubricating oil compositions of this specification may optionally also contain one or more molybdenum-containing compounds. Oil-soluble molybdenum compounds may have the functional properties of anti-wear agents, antioxidants, friction modifiers, or mixtures thereof. Oil-soluble molybdenum compounds may include molybdenum dithiocarbamates, molybdenum dialkyldithiophosphates, molybdenum dithiophosphinates, amine salts of molybdenum compounds, molybdenum xanthanates, molybdenum thioxanthanates, molybdenum sulfides, molybdenum carboxylates, molybdenum alkoxides, trinuclear organic molybdenum compounds, and / or mixtures thereof. Molybdenum sulfides include molybdenum disulfides. Molybdenum disulfides may be in the form of stable dispersants. 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 may be molybdenum dithiocarbamate.

[0122] Suitable examples of molybdenum compounds that can be used include commercially available materials sold under trade names such as Molyvan 822®, Molyvan® A, Molyvan 2000®, and Molyvan 855® from RTVanderbilt Co., Ltd., as well as commercially available materials sold under trade names such as Sakura-Lube® S-165, S-200, S-300, S-310G, S-525, S-600, S-700, and S-710 from Adeka Corporation, and mixtures thereof. Suitable molybdenum components are described in US5,650,381, US RE37,363 E1, US RE38,929 E1, and US RE40,595 E1, which are incorporated herein by reference in their entirety.

[0123] Additionally, the molybdenum compounds may be acidic molybdenum compounds. These include molybdic acid, ammonium molybrate, sodium molybrate, potassium molybrate, and other alkali metal molybrates and other molybdenum salts, such as sodium hydrogen molybrate, MoOCl4, MoO2Br2, Mo2O3Cl6, molybdenum trioxide, or similar acidic molybdenum compounds. Alternatively, compositions may include, for example, molybdenum in the form of molybdenum / sulfur complexes of basic nitrogen compounds described in U.S. Patents 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, which are incorporated herein by reference in their entirety, as well as WO94 / 06897.

[0124] Another class of preferred organomolybdenum compounds are trinuclear molybdenum compounds and mixtures thereof, such as compounds of the formula Mo3SkLnQz, where S represents sulfur, L represents an independently selected ligand having a sufficient number of carbon atoms to make the organic group 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-donating compounds such as water, amines, alcohols, phosphines, and ethers, and z is in the range of 0 to 5, including non-stoichiometric values. All ligand organic groups may contain at least 21 total carbon atoms, such as at least 25, at least 30, or at least 35 carbon atoms. Additional preferred molybdenum compounds are described in U.S. Patent No. 6,723,685, which is incorporated herein by reference in whole.

[0125] The oil-soluble molybdenum compound may be present in an amount sufficient to provide molybdenum in the ranges of approximately 0.5 ppm to approximately 2000 ppm, approximately 1 ppm to approximately 700 ppm, approximately 1 ppm to approximately 550 ppm, approximately 5 ppm to approximately 300 ppm, or approximately 20 ppm to approximately 250 ppm.

[0126] Transition metal-containing compounds: In another embodiment, the oil-soluble compound may be a transition metal-containing compound or a metalloid. Transition metals may include, but are not limited to, titanium, vanadium, copper, zinc, zirconium, molybdenum, tantalum, tungsten, and the like. Preferred metalloids include, but are not limited to, boron, silicon, antimony, tellurium, and the like.

[0127] In some embodiments, the oil-soluble transition metal-containing compound may function as an anti-wear agent, friction modifier, antioxidant, 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 the disclosed technology or in the preparation of oil-soluble materials of the disclosed technology are various Ti(IV) compounds such as titanium(IV) oxide, titanium(IV) sulfide, and titanium(IV) nitrate; titanium(IV) alkoxides such as titanium methoxide, titanium ethoxide, titanium propoxide, titanium isopropoxide, titanium butoxide, and titanium 2-ethylhexoxide; and other titanium compounds or complexes including 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)(triethanolamine)isopropoxide. Other forms of titanium encompassed in the disclosed technology include titanium phosphates such as titanium dithiophosphates (e.g., dialkyldithiophosphates) and titanium sulfonates (e.g., alkylbenzene sulfonates), or reaction products of titanium compounds that form salts, such as oil-soluble salts, with various acidic substances. Therefore, titanium compounds can be derived, among other things, from organic acids, alcohols, and glycols. Ti compounds may also exist in dimer or oligomeric forms containing a Ti-O-Ti structure. Such titanium materials are commercially available or readily prepared by suitable synthetic techniques evident to those skilled in the art. These may exist as solids or liquids at room temperature, depending on the specific compound. They may also be provided in solution form in a suitable inert solvent.

[0128] In one embodiment, titanium may be supplied as a Ti-modified dispersant such as a succinimide dispersant. Such a material may be prepared by forming a titanium mixed anhydride between a titanium alkoxide and a hydrocarbyl-substituted succinic anhydride such as alkenyl-(or alkyl-) succinic anhydride. The resulting succinate titanate intermediate may be used directly or reacted with any of a number of substances such as (a) a polyamine succinimide / amide dispersant having a free, condensable --NH functional group, (b) a polyamine succinimide / amide dispersant, i.e., a component of alkenyl-(or alkyl-) succinic anhydride and a polyamine, (c) a hydroxy-containing polyester dispersant prepared by the reaction of substituted succinic anhydride with a polyol, amino alcohol, polyamine, or a mixture thereof. Alternatively, the succinate titanate intermediate may be reacted with other agents such as an alcohol, amino alcohol, ether alcohol, polyether alcohol or polyol, or a fatty acid, and the product may be used directly to impart Ti to a lubricant or further reacted with a succinic acid dispersant as described above. For example, to provide a titanium-modified dispersant or intermediate, 1 part (mol) of tetraisopropyl titanate may be reacted with about 2 parts (mol) of polyisobutene-substituted succinic anhydride at 140-150°C for 5-6 hours. The resulting material (30 g) may be further reacted at 150°C for 1.5 hours with a succinimide dispersant made from a mixture of polyisobutene-substituted succinic anhydride and polyethylene polyamine (127 g + diluent oil) to produce a titanium-modified succinimide dispersant.

[0129] Another titanium-containing compound is titanium alkoxide and C6-C6 25 The reaction product may also be a reaction product with a carboxylic acid. The reaction product may be represented by the following formula: [ka] In the formula, n is an integer selected from 2, 3, and 4, and R is a hydrocarbyl group containing about 5 to about 24 carbon atoms, or may be represented by the following formula: [ka] In the formula, m+n=4, n is in the range of 1 to 3, R4 is an alkyl moiety having 1 to 8 carbon atoms, R1 is selected from a hydrocarbyl group containing approximately 6 to 25 carbon atoms, and R2 and R3 are the same or different, selected from a hydrocarbyl group containing 1 to 6 carbon atoms, or the titanium compound may be represented by the following formula: [ka] In the formula, x is in the range of 0 to 3, R1 is selected from hydrocarbyl groups containing approximately 6 to 25 carbon atoms, R2 and R3 are the same or different and selected from hydrocarbyl groups containing approximately 1 to 6 carbon atoms, and R4 is H, C6 to C 25 Selected from the group consisting of any of the carboxylic acid moieties.

[0130] Suitable carboxylic acids may include, but are not limited to, caproic acid, caprylic acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, oleic acid, erucic acid, linoleic acid, linolenic acid, cyclohexanecarboxylic acid, phenylacetic acid, benzoic acid, and neodecanoic acid.

[0131] In one embodiment, the oil-soluble titanium compound may be present in the lubricating oil composition in an amount that provides about 0 to about 3000 ppm by weight of titanium, or about 25 to about 1500 ppm by weight of titanium, or about 35 ppm to about 500 ppm by weight of titanium, or about 50 ppm to about 300 ppm by weight of titanium.

[0132] Viscosity Index Improvers: The lubricating oil compositions of this specification may optionally contain one or more viscosity index improvers. Suitable viscosity index improvers may include polyolefins, olefin copolymers, ethylene / propylene copolymers, polyisobutene, styrene-isoprene polymers, styrene / maleate copolymers, styrene-butadiene copolymers, styrene-isoprene polymers, alpha-olefin maleic anhydride copolymers, polymethacrylates, polyacrylates, polyalkylstyrenes, hydrated alkenylaryl conjugated diene copolymers, or mixtures thereof. Viscosity index improvers may also include star polymers, and suitable examples are described in U.S. Publication No. 2012 / 0101017(A1).

[0133] The lubricating oil compositions herein may optionally contain, in addition to or instead of viscosity index improvers, one or more dispersant viscosity index improvers. Suitable viscosity index improvers may include functionalized polyolefins, such as ethylene-propylene copolymers functionalized with reaction products of acylating agents (such as maleic anhydride) and amines, amine-functionalized polymethacrylates, or esterified maleic anhydride-styrene copolymers reacted with amines.

[0134] Viscosity index improver and / or dispersant. The total amount of viscosity index improver may be about 0% to about 20% by weight, about 0.1% to about 15% by weight, about 0.1% to about 12% by weight, or about 0.5% to about 10% by weight of the lubricating oil composition.

[0135] Other optional additives: Other additives may be selected to perform one or more functions required of the lubricating fluid. Furthermore, one or more of the aforementioned additives may be polyfunctional and may provide functions in addition to those described herein, or other functions.

[0136] Lubricant compositions according to this disclosure may optionally contain other performance additives. These other performance additives may be additions to specific additives of this disclosure, and / or may include one or more of the following: metal deactivators, viscosity index improvers, detergents, ashless TBN boosters, friction modifiers, anti-wear agents, corrosion inhibitors, rust inhibitors, dispersants, dispersant viscosity index improvers, extreme pressure agents, antioxidants, foam inhibitors, deemulsifiers, emulsifiers, pour point depressants, seal swelling agents, and mixtures thereof. Typically, a complete lubricant composition contains one or more of these performance additives.

[0137] Suitable metal deactivators may include benzotriazole derivatives (typically toltriazole), dimercaptothiadiazole derivatives, 1,2,4-triazole, benzimidazole, 2-alkyldithiobenzimidazole, or 2-alkyldithiobenzothiazole; foam inhibitors comprising ethyl acrylate and 2-ethylhexyl acrylate and optionally vinyl acetate copolymers; deemulsifiers comprising trialkyl phosphate, polyethylene glycol, polyethylene oxide, polypropylene oxide, and (ethylene oxide-propylene oxide) polymers; and pour point depressants comprising maleic anhydride-styrene esters, polymethacrylate, polyacrylate, or polyacrylamide.

[0138] Suitable foam inhibitors include silicon-based compounds such as siloxanes.

[0139] Suitable pour point depressants may include polymethyl methacrylate or mixtures thereof. The pour point depressant may be present in an amount sufficient to provide about 0% to about 1% by weight, about 0.01% to about 0.5% by weight, or about 0.02% to about 0.04% by weight, based on the final weight of the lubricating oil composition.

[0140] Suitable rust inhibitors may be a single compound or a mixture of compounds having properties that inhibit corrosion of 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 dimeric and trimeric acids such as those derived from tall oil fatty acids, oleic acid, and linoleic acid. Other suitable corrosion inhibitors include long-chain alpha- and omega-dicarboxylic acids in the molecular weight range of about 600 to about 3000, and alkenyl succinates containing about 10 or more carbon atoms in the alkenyl group, such as tetrapropenyl succinic acid, tetradecenyl succinic acid, and hexadecenyl succinic acid. Other useful types of acidic corrosion inhibitors are semi-esters of alkenyl succinates having about 8 to about 24 carbon atoms in the alkenyl group with alcohols such as polyglycols. The corresponding semiamides 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 rust inhibitors.

[0141] If present, rust inhibitors may be used in an amount sufficient to provide about 0% to about 5% by weight, about 0.01% to about 3% by weight, or about 0.1% to about 2% by weight, based on the final weight of the lubricating oil composition.

[0142] Generally speaking, a suitable crankcase lubricant may contain additive components within the range listed in the table below. [Table 2]

[0143] The percentages of each component listed above represent the weight percentage of each component based on the weight of the final lubricating oil composition. The remainder of the lubricating oil composition consists of one or more base oils. The additives used in formulating the compositions described herein may be blended with the base oils individually or in various partial combinations. However, it may be preferable to blend all the components simultaneously using an additive concentrate (i.e., the additive plus a diluent such as a hydrocarbon solvent). [Examples]

[0144] The following examples illustrate exemplary embodiments of the present disclosure. In these examples and elsewhere in this application, all proportions, parts, and percentages are by weight unless otherwise indicated. These examples are intended to be presented for illustrative purposes only and are not intended to limit the scope of the invention disclosed herein.

[0145] Example 1 Various polymer additives were evaluated in both ACEA and GF6 style lubricant compositions using various blends of heavier and lighter base oils. The copolymer additives considered for this study are provided in Table 3 below and include both olefin polymers and (meth)acrylate polymers. [Table 3]

[0146] The polymers listed in Table 3 were used in the ACEA-based formulation of 0W-20 lubricant shown in Table 4, and the GF6-based formulation of 5W-20 lubricant shown in Table 5. In formulations with the selected (meth)acrylate polymers, SAE certification could be achieved by increasing the amount of heavier base oil. [Table 4] [Table 5]

[0147] Example 2 Another study of 0W-20 ACEA formulations compares OCP polymer A and PMA polymer B from Table 3 above, as shown in Table 6 below. [Table 6]

[0148] Based on the data from this embodiment, viscosity maps can be created in Figure 1 for various potential formulations using polymers A and B, demonstrating that polymer B of this application, when combined with the base oil blends described above, provides greater flexibility in the formulation space to achieve SAE parameters. For example, formulations using polymer B can be formulated down to a full kV unit lower (approximately 0.5 to 0.75 kV units lower in other approaches), regardless of the target CCS, compared to formulations with polymer A. In other cases, formulations using polymer B can be formulated near the lower end of the KV100 specification, and still provide shear results within the SAE grade at lower CCS35 values. It was surprising that the polymers of this disclosure could achieve such performance when combined with so many heavier base oils.

[0149] As used herein and in the appended claims, the singular forms “a,” “an,” and “the” include multiple referents unless explicitly and clearly limited to one. For example, a reference to “antioxidants” includes two or more different antioxidants. Where used herein, the term “includes” and its grammatical variations are intended to be non-limiting so as not to exclude other similar items that may be substituted for or added to the items in the list.

[0150] For the purposes of this specification and the appended claims, unless otherwise specified, all numbers representing quantities, percentages or proportions, and other numerical values ​​used herein and in the claims are understood to be modified in all cases by the term “approximately.” Therefore, unless otherwise specified, the numerical parameters described in the following specification and the appended claims are approximations that may vary depending on the desired characteristics to be obtained by this disclosure. At a minimum, each numerical parameter should be interpreted, not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, but at least in terms of the number of significant figures reported and by applying common rounding techniques.

[0151] It should be understood that each component, compound, substituent, or parameter disclosed herein is disclosed for use alone or in combination with any one or more other components, compounds, substituents, or parameters disclosed herein.

[0152] It should be further understood that each range disclosed herein should be interpreted as a disclosure of each specific value within the disclosure range having the same number of significant figures. Therefore, for example, the range 1–4 should be interpreted as a clear disclosure of any range of such values, not just the values ​​1, 2, 3, and 4.

[0153] It should be 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. Therefore, this 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 with 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 should also be further understood that any range between endpoint values ​​within a broad range is also considered herein. Thus, the range 1-4 also means ranges such as 1-3, 1-2, 2-4, 2-3, etc.

[0154] Furthermore, any specific amounts / values ​​of components, compounds, substituents, or parameters disclosed in the description or examples should be interpreted as disclosures of either a lower or upper limit of a range, and can therefore be combined with any other lower or upper limit or specific amounts / values ​​of the 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.

[0155] While specific embodiments have been described, alternatives, modifications, variations, improvements, and substantial equivalents may emerge that are not currently anticipated or can not be anticipated by the applicants or others skilled in the art. Accordingly, the attached claims filed and any modified attached claims are intended to encompass all such alternatives, modifications, variations, improvements, and substantial equivalents.

Claims

1. A multigrade lubricating oil composition that achieves SAE J300 certification for at least 0W-16, 0W-20, and 5W-20 grade oils, with an increased amount of heavier base oil, A blend of base oils comprising at least one lighter base oil having a KV100 of 4.5 cSt or less, and at least one heavier base oil having a KV100 of 5.5 cSt or more, wherein the base oil blend contains at least 20 weight percent of the at least one heavier base oil based on the total weight of the base oils in the blend. A multigrade lubricating oil composition comprising a (meth)acrylate copolymer of 1 weight percent or less based on a polymer solid having a hydrocarbyl group in the monomer ester portion, wherein the (meth)acrylate copolymer comprises, as polymerization monomer units, (i) a (meth)acrylate monomer unit having a hydrocarbyl group with an intermediate weight-average molecular weight of 500 to 700 in the monomer ester portion, and (ii) a (meth)acrylate monomer unit having a hydrocarbyl group with a high weight-average molecular weight of 6,000 to 10,000 in the monomer ester portion, and a (meth)acrylate copolymer.

2. The multigrade lubricating oil composition according to claim 1, wherein the multigrade lubricating oil composition exhibits a kinematic viscosity of 9.3 mm² / sec or less at 100°C and a CCS of 6200 mPa or less at -35°C.

3. The multigrade lubricating oil composition according to claim 2, wherein a blend of two or more lighter base oils is selected from API Group II base oils, API Group III base oils, API Group IV base oils, or a combination thereof, or the at least one heavier base oil is selected from API Group III base oils, API Group IV base oils, or a combination thereof, and / or the base oil blend comprises at least 40 weight percent of the heavier base oil.

4. The multigrade lubricating oil composition according to claim 1, wherein the ratio of the lighter base oil to the heavier base oil is 1.55 or less, and / or the base oil blend comprises 40 to 60 weight percent of the heavier base oil, and / or the at least one lighter base oil is a blend of two or more base oils, each having a KV100 of 4.5 cSt or less.

5. The multigrade lubricating oil composition according to claim 1, wherein the (meth)acrylate copolymer has a number average molecular weight of 140,000 or more, and / or the (meth)acrylate copolymer has a number average molecular weight of 500,000 or less.

6. The multigrade lubricating oil composition according to claim 1, wherein the (meth)acrylate copolymer further comprises, as polymerization monomer units, (iii) (meth)acrylate monomer units having a hydrocarbyl group with a low weight-average molecular weight of 400 or less in the monomer ester portion.

7. The multigrade lubricating oil composition according to claim 6, wherein the (meth)acrylate copolymer is derived from a (meth)acrylate monomer having a hydrocarbyl moiety of 12 to 16 carbon atoms and a (meth)acrylate monomer having a hydrocarbyl moiety derived from a macromonomer of an alkene or alkadiene containing ethylene, propylene, butene, butadiene, isoprene, or a combination thereof, and having a weight-average molecular weight of 10,000 or less.

8. The multigrade lubricating oil composition according to claim 1, wherein the molecular weight ratio of the high weight-average molecular weight hydrocarbyl groups in the (meth)acrylate monomer ester portion of the copolymer to the low weight-average molecular weight hydrocarbyl groups is 1.5:1 to 50:

1.

9. The multigrade lubricating oil composition according to claim 1, further comprising a hydrocarbyl-substituted succinamide dispersant or succinimide dispersant, and / or the multigrade lubricating oil composition comprising 1 to 8 weight percent of the hydrocarbyl-substituted succinamide dispersant or succinimide dispersant.

10. The multigrade lubricating oil composition according to claim 9, wherein the hydrocarbyl-substituted succinamide dispersant or succinimide dispersant is derived from a hydrocarbyl-substituted acylating agent reacted with a polyalkylene polyamine, and the hydrocarbyl substituent of the succinamide dispersant or succinimide dispersant is a linear or branched hydrocarbyl group having a number average molecular weight of 250 to 5,000 when measured by GPC using polystyrene as a calibration standard.

11. The polyalkylene polyamine has the following formula: 【Chemistry 1】 In the formula, each R and R' is independently a divalent C1-C6 alkylene linker, and each R １ and R ２ The multigrade lubricating oil composition according to claim 10, wherein, independently, hydrogen, a C1-C6 alkyl group, or a nitrogen atom to which they are bonded, optionally fuses with one or more aromatic or non-aromatic rings to form a five-membered or six-membered ring, and n is an integer from 0 to 8.

12. The multigrade lubricating oil composition according to claim 11, wherein the polyalkylene polyamine is selected from the group consisting of a mixture of polyethylene polyamines having an average of 5 to 7 nitrogen atoms, triethylenetetramine, tetraethylenepentaamine, and combinations thereof.

13. A method for formulating a multigrade lubricant composition that achieves SAE J300 certification for at least 0W-16, 0W-20, and 5W-20 grade oils, with an increased amount of heavier base oil, The present invention involves blending a certain amount of base oil having 1% or less by weight of a (meth)acrylate copolymer based on a polymer solid to form a multigrade lubricant composition that exhibits a kinematic viscosity of 9.3 mm² / sec or less at 100°C and a CCS viscosity of 6200 mPa or less at -35°C, and exhibits a kinematic viscosity up to 1 kV lower at the target CCS viscosity compared to a multigrade lubricant composition that does not contain the (meth)acrylate copolymer, The base oil comprises a blend of at least one lighter base oil having a KV100 of 4.5 cSt or less and at least one heavier base oil having a KV100 of 5.5 cSt or more, wherein the base oil blend contains at least 20 weight percent of the at least one heavier base oil based on the total weight of the base oils in the blend. A method wherein the (meth)acrylate copolymer comprises, as polymerization monomer units, (i) a (meth)acrylate monomer unit having a hydrocarbyl group with an intermediate weight-average molecular weight of 500 to 700 in the monomer ester portion, and (ii) a (meth)acrylate monomer unit having a hydrocarbyl group with a high weight-average molecular weight of 6,000 to 10,000 in the monomer ester portion.

14. The method according to claim 13, wherein the base oil blend includes a ratio of 1.55 or less of the lighter base oil to the heavier base oil, and the base oil blend includes 40 to 60 weight percent of the heavier base oil.

15. The method according to claim 14, wherein the multigrade lubricating oil composition comprises 1 to 8 weight percent of the hydrocarbyl-substituted succinamide dispersant or succinimide dispersant.

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