CN118265765A

CN118265765A - Lubricating oil composition

Info

Publication number: CN118265765A
Application number: CN202280076562.7A
Authority: CN
Inventors: K·J·蔡斯; S·A·斯克尔顿; G·D·胡伦
Original assignee: Chevron Oronite Co LLC
Current assignee: Chevron Oronite Co LLC
Priority date: 2021-11-03
Filing date: 2022-11-03
Publication date: 2024-06-28
Also published as: WO2023079475A1; CA3237045A1; EP4426802A1

Abstract

The application relates to functional oil or EV oil. The functional oil may comprise a major amount of an oil of lubricating viscosity, at least one overbased sulfonate detergent, and an anti-fatigue additive. The functional oil or EV oil provides surprising and unexpected fatigue characteristics.

Description

Lubricating oil composition

The inventors: kevin J.Chase and Shelby A.Shelton and George D.Huron

Technical Field

The present disclosure relates to lubricating oil compositions that provide enhanced anti-fatigue protection.

Background

Modern lubricating oil formulations are formulated in accordance with stringent specifications typically set by original equipment manufacturers. To meet such specifications, it is necessary to use various additives as well as a base oil of lubricating viscosity. Depending on the application, typical lubricating oil compositions may contain dispersants, detergents, antioxidants, wear inhibitors, rust inhibitors, corrosion inhibitors, foam inhibitors, friction modifiers, and the like.

Different applications will determine the type of additives in the lubricating oil composition. For example, conventional road car lubricants are often required to meet certain wear resistance specifications, but typically have no similar requirements for fatigue resistance. However, other lubricating oil compositions may benefit from enhanced anti-fatigue properties. For example, functional oil and Electric Vehicle (EV) oil used in high strength load bearing environments are included. In such environments, the metal surface is particularly susceptible to pitting or void formation due to repeated loading and contact stresses exceeding the surface fatigue strength of the material.

Functional fluid is a term that encompasses a variety of fluids including, but not limited to, tractor hydraulic fluids, power transmission fluids (including Automatic Transmission Fluids (ATF), traction fluids, continuously Variable Transmission (CVT) fluids, and manual transmission fluids), hydraulic fluids (including tractor hydraulic fluids), gear fluids, power steering fluids, fluids used in wind turbines, and fluids associated with powertrain components. It should be noted that in each type of oil (such as automatic transmission oil), because the various transmissions have different designs, oil having significantly different functional characteristics is required, and thus there are many different types of oil.

In the case of tractor hydraulic oils, these oils are common products for all lubricant applications in the tractor except for lubricating the engine. So-called super tractor oil utility or "STOU" oil may also lubricate the engine. These lubrication applications may include lubrication of gearboxes, power take-offs and clutches, rear axles, reduction gears, wet brakes, and hydraulic accessories. The components contained in the tractor oil must be carefully selected so that the resulting oil composition will provide all the necessary characteristics required for different applications. Such features may include the ability to provide suitable friction characteristics to prevent wet brake rattle of the oil-filled brake, while providing the ability to activate the wet brake and providing Power Take Off (PTO) clutch performance. Tractor oil must provide adequate antiwear, antifatigue and extreme pressure properties and water resistance/filtration capabilities. For example, existing tractor oil formulations typically employ high levels of sulfur-containing phenates to provide adequate fatigue resistance properties to the oil.

There is now a recognized need for lubricating oil compositions having reduced sulfur-containing phenate levels. It would also be desirable if such compositions could be used in functional oil (e.g., construction machinery), electric vehicles, hybrid vehicles (including plug-in hybrid vehicles), etc., while maintaining acceptable limits for bearing fatigue protection and/or meeting stringent fatigue specification requirements. Advantageously, the compositions described herein meet one or more of the needs described above, as well as further needs.

Disclosure of Invention

In particular, the present application relates to a lubricant additive ("anti-fatigue additive") composition characterized by having enhanced anti-fatigue properties. In some embodiments, the anti-fatigue additive imparts enhanced anti-fatigue properties to a lubricating oil composition, such as those described herein. In some embodiments, the lubricating oil composition contains a relatively low level of sulfur-containing compounds, which are typically used to provide anti-fatigue properties. These sulfur-containing compounds include sulfurized overbased phenates and zinc dithiophosphates.

More specifically, the present application relates to lubricating oil compositions comprising from 0.001% to 1.5% of an anti-fatigue additive and a sulfonate detergent. In some embodiments, the lubricating oil composition contains a low level of metal-containing thiophenols (e.g., about 40 mmoles or less of metal from the metal-sulfurized phenates, such as 35 mmoles or less, 30 mmoles or less, 25 mmoles or less, 20 mmoles or less, 10 mmoles or less, and 0 mmoles) to provide improved fatigue protection and performance. By adding glycerol, the lubricating oil composition exhibits improved fatigue properties even at lower levels of sulfur-containing additives. The compositions described herein generally provide reduced material fatigue. The composition may also reduce bearing formation surface fatigue, micropitting or subsurface fatigue and/or pitting.

In one embodiment, the present application is directed to a functional or EV oil comprising (a) a major amount of an oil of lubricating viscosity; (b) An anti-fatigue additive comprising an alkyl polyol or derivative thereof comprising 2 to 20 carbon atoms; and (c) at least one overbased sulfonate detergent and at least one non-sulfonate detergent. In another embodiment, the anti-fatigue additive is present in an amount of about 0.001 wt.% to about 1.5 wt.% based on the total weight of the functional oil or EV oil. In another embodiment, the amount of anti-fatigue additive added is such that the fatigue time of the functional oil or EV oil is increased over a similar oil without the anti-fatigue additive, as determined by the ZF bearing pitting test. In another embodiment, the functional oil or EV oil may be used in a method of increasing bearing fatigue time, including contacting a metal surface with the functional oil or EV oil.

In one embodiment, the present application is directed to a hybrid vehicle oil or plug-in hybrid vehicle oil comprising (a) a major amount of an oil of lubricating viscosity; (b) An anti-fatigue additive comprising an alkyl polyol or derivative thereof comprising 2 to 20 carbon atoms; and (c) at least one overbased sulfonate detergent and at least one non-sulfonate detergent. In another embodiment, the amount of the anti-fatigue additive is about 0.001 wt% to about 1.5 wt% based on the total weight of the hybrid vehicle oil or plug-in hybrid vehicle oil. In another embodiment, the amount of anti-fatigue additive added is such that the fatigue time of the hybrid vehicle fluid or plug-in hybrid vehicle fluid is increased over a similar fluid without the anti-fatigue additive, as determined by the ZF bearing pitting test. In another embodiment, a hybrid vehicle fluid or plug-in hybrid vehicle fluid may be used in a method of increasing bearing fatigue time, including contacting a metal surface with the hybrid vehicle fluid or plug-in hybrid vehicle fluid.

Detailed Description

Definition of the definition

Unless otherwise indicated, the following terms will be used throughout the specification and will have the following meanings.

The term "major amount" of base oil refers to the case where the amount of base oil is at least 40 wt.% of the lubricating oil composition. In some embodiments, a "major amount" of base oil refers to an amount of base oil that is greater than 50 wt.%, greater than 60 wt.%, greater than 70 wt.%, greater than 80 wt.%, or greater than 90 wt.% of the lubricating oil composition.

In the following description, all numbers disclosed herein are approximate values, regardless of whether the word "about" or "approximately" is used in conjunction therewith. It may vary by 1%, 2%, 5%, or sometimes by 10% to 20%.

The term "construction machine" refers to off-road heavy vehicles and off-road vehicles and/or machines including, but not limited to, excavators, dozers, loaders, lithotripters, pavers, compactors, and cranes.

"HOB" refers to high overbasing with TBN above 250 on an active basis, while "LOB" refers to low overbasing with TBN below 100 on an active basis.

"TPP" means tetrapropenyl phenol or its salts.

The term "total base number" or "TBN" refers to the level of alkalinity in an oil sample as per ASTM standard No. D2896 or equivalent procedure, which indicates the ability of the composition to continue to neutralize corrosive acids. The test measures the change in conductivity and the results are expressed as mgKOH/g (milliequivalents of KOH required to neutralize 1 gram of product). Thus, a high TBN reflects a strong overbased product and is therefore a higher base store for neutralizing the acid.

As used herein, EV oil refers to electrically driven oil used in electric vehicles equipped with wet EV motors. Electrically driven oil is similar to transmission oil (for conventional automobiles), but typically has one or more additional functions (e.g., acting as a coolant for EV motors, providing electrical resistivity, etc.). One or more additional functions may present unique challenges to formulating EV oil.

In some embodiments, the lubricating oil compositions of the present invention may provide anti-fatigue benefits to a hybrid vehicle equipped with an electric motor (hybrid vehicle oil) or a plug-in hybrid vehicle (plug-in hybrid vehicle oil).

Oil of lubricating viscosity

The lubricating oil compositions disclosed herein generally comprise at least one oil of lubricating viscosity. Any base oil known to those skilled in the art may be used as the oil of lubricating viscosity disclosed herein. Some base oils suitable for use in preparing lubricating oil compositions are described in the following documents: mortier et al, "CHEMISTRY AND Technology of Lubricants", 2 nd edition, london, springer, chapters 1 and 2 (1996); and a.sequencer, jr., "Lubricant Base Oil and Wax Processing", new York, MARCEL DECKER, chapter 6, (1994); and D.V. Brock, lubrication Engineering, volume 43, pages 184-5, (1987), all of which are incorporated herein by reference. Typically, the amount of base oil in the lubricating oil composition may be from about 70 wt.% to about 99.5 wt.%, based on the total weight of the lubricating oil composition. In some embodiments, the amount of base oil in the lubricating oil composition is from about 75 wt.% to about 99 wt.%, from about 80 wt.% to about 98.5 wt.%, or from about 80 wt.% to about 98 wt.%, based on the total weight of the lubricating oil composition.

In certain embodiments, the base oil is or comprises any natural or synthetic lubricating base oil fraction. Some non-limiting examples of synthetic oils include oils prepared from the polymerization of at least one alpha-olefin, such as ethylene, or from hydrocarbon synthesis procedures using carbon monoxide and hydrogen, such as the Fischer-Tropsch process, such as polyalphaolefins or PAOs. In certain embodiments, the base oil comprises less than about 10 weight percent of one or more heavy fractions, based on the total weight of the base oil. The heavy fraction refers to a lube fraction having a viscosity of at least about 20cSt at 100 ℃. In certain embodiments, the heavy fraction has a viscosity of at least about 25cSt or at least about 30cSt at 100 ℃. In further embodiments, the amount of one or more heavy fractions in the base oil is less than about 10 wt%, less than about 5 wt%, less than about 2.5 wt%, less than about 1 wt%, or less than about 0.1 wt%, based on the total weight of the base oil. In yet other embodiments, the base oil does not comprise a heavy fraction.

In certain embodiments, the lubricating oil composition comprises a major amount of a base oil of lubricating viscosity. In some embodiments, the base oil has a kinematic viscosity at 100 ℃ of from about 2.5 centistokes (cSt) to about 20cSt, from about 4 cSt to about 20cSt, or from about 5cSt to about 16cSt. The kinematic viscosity of the base oils or lubricating oil compositions disclosed herein may be measured according to ASTM D445, which is incorporated herein by reference.

In other embodiments, the base oil is or comprises a base stock or blend of base stocks. In further embodiments, base stocks are manufactured using a variety of different processes including, but not limited to, distillation, solvent refining, hydroprocessing, oligomerization, esterification, and rerefining. In some embodiments, the base stock comprises a rerefined stock. In further embodiments, the rerefined stock should be substantially free of materials introduced by manufacture, contamination, or prior use.

In some embodiments, the base oil comprises one or more base Oils as specified in one or more of group I-group V as specified in American Petroleum Institute (API) publication 1509, fourteenth edition, month 12 1996 (i.e., API Base Oil Interchangeability Guidelines for PASSENGER CAR Motor Oils AND DIESEL ENGINE Oils), which is incorporated herein by reference. API guidelines define base stocks as lubricant components that can be manufactured using a variety of different methods. Group I, group II and group III base stocks are mineral oils, each having a particular range of saturates, sulfur content and viscosity index. Group IV base stocks are Polyalphaolefins (PAOs). Group V base stocks include all other base stocks not included in group I, group II, group III or group IV.

In some embodiments, the base oil comprises one or more base stocks of group I, group II, group III, group IV, group V base stocks, or a combination thereof. In other embodiments, the base oil comprises one or more base oils of group II, group III, group IV base oils, or a combination thereof. In further embodiments, the base oil comprises one or more base stocks of group II, group III, group IV, or a combination thereof, wherein the base oil has a kinematic viscosity at 100 ℃ of from about 2.5 centistokes (cSt) to about 20cSt, from about 4cSt to about 20cSt, or from about 5cSt to about 16 cSt.

The base oil may be selected from the group consisting of natural oils of lubricating viscosity, synthetic oils of lubricating viscosity, and mixtures thereof. In some embodiments, the base oils include base stocks obtained by isomerization of synthetic wax and slack wax, as well as hydrocracked base stocks produced by hydrocracking (rather than solvent extracting) the aromatic and polar components of the crude. In other embodiments, base oils of lubricating viscosity include natural oils such as animal oils, vegetable oils, mineral oils (e.g., liquid petroleum oils and mineral oils of the solvent treated or acid treated paraffinic, naphthenic or mixed paraffinic-naphthenic types), oils derived from coal or shale, and combinations thereof. Some non-limiting examples of animal oils include bone oil, lanolin, fish oil, lard, dolphin oil, seal oil, shark oil, tallow, and whale oil. Some non-limiting examples of vegetable oils include castor oil, olive oil, peanut oil, canola oil, corn oil, sesame oil, cottonseed oil, soybean oil, sunflower oil, safflower oil, hemp oil, linseed oil, tung oil, bast oil, jojoba oil, and meadowfoam seed oil. Such oils may be partially or fully hydrogenated.

In some embodiments, synthetic oils of lubricating viscosity include hydrocarbon oils and halogen-substituted hydrocarbon oils such as polymerized and interpolymerized olefins, alkylbenzenes, polyphenyls, alkylated diphenyl ethers, alkylated diphenyl sulfides, as well as derivatives, analogs, homologs, and the like thereof. In other embodiments, synthetic oils include alkylene oxide polymers, interpolymers, copolymers, and derivatives thereof where the terminal hydroxyl groups may be modified by esterification, etherification, etc. In further embodiments, the synthetic oil includes esters of dicarboxylic acids with various alcohols. In certain embodiments, the synthetic oil includes esters prepared from C ₅ to C ₁₂ monocarboxylic acids, polyols, and polyol ethers. In further embodiments, the synthetic oil includes a trialkyl phosphate oil, such as tri-n-butyl phosphate and tri-isobutyl phosphate.

In some embodiments, synthetic oils of lubricating viscosity include silicon-based oils (such as polyalkyl-, polyaryl-, polyalkoxy-, polyaryloxy-siloxane oils and silicate oils). In other embodiments, the synthetic oil includes liquid esters of phosphorus-containing acids, polymeric tetrahydrofurans, polyalphaolefins, and the like.

Base oils derived from wax hydroisomerization may also be used alone or in combination with the natural and/or synthetic base oils described above. Such wax isomerates are produced by hydroisomerizing natural or synthetic waxes or mixtures thereof over a hydroisomerization catalyst.

In further embodiments, the base oil comprises a poly-alpha-olefin (PAO). Generally, the poly-alpha-olefin may be derived from an alpha-olefin having from about 2 to about 30, from about 4 to about 20, or from about 6 to about 16 carbon atoms. Non-limiting examples of suitable poly-alpha-olefins include those derived from octene, decene, mixtures thereof, and the like. These poly-alpha-olefins may have a viscosity at 100 ℃ of from about 2 centistokes to about 15 centistokes, from about 3 centistokes to about 12 centistokes, or from about 4 centistokes to about 8 centistokes. In some examples, the poly-alpha-olefins may be used with other base oils (such as mineral oils).

In further embodiments, the base oil comprises a polyalkylene glycol or polyalkylene glycol derivative, wherein the terminal hydroxyl groups of the polyalkylene glycol may be modified by esterification, etherification, acetylation, and the like. Non-limiting examples of suitable polyalkylene glycols include polyethylene glycol, polypropylene glycol, polyisopropylene glycol, and combinations thereof. Non-limiting examples of suitable polyalkylene glycol derivatives include ethers of polyalkylene glycols (e.g., methyl ether of poly (isopropyl glycol), diphenyl ether of polyethylene glycol, diethyl ether of polypropylene glycol, and the like), mono-and polycarboxylic esters of polyalkylene glycols, and combinations thereof. In some examples, the polyalkylene glycol or polyalkylene glycol derivative may be used with other base oils (such as poly-alpha-olefins and mineral oils).

In further embodiments, the base oil comprises any of the esters of dicarboxylic acids (e.g., phthalic acid, succinic acid, alkyl succinic acids, alkenyl succinic acids, maleic acid, azelaic acid, suberic acid, sebacic acid, fumaric acid, adipic acid, linoleic acid dimer, malonic acid, alkyl malonic acids, alkenyl malonic acids, etc.) with a variety of alcohols (e.g., butanol, hexanol, dodecanol, 2-ethylhexanol, ethylene glycol, diethylene glycol monoether, propylene glycol, etc.). Non-limiting examples of such esters include dibutyl adipate, di (2-ethylhexyl) sebacate, di-n-hexyl fumarate, dioctyl sebacate, diisooctyl azelate, diisodecyl azelate, dioctyl phthalate, didecyl phthalate, di (eicosyl) sebacate, 2-ethylhexyl diester of linoleic acid dimer, and the like.

In further embodiments, the base oil comprises hydrocarbons produced by a fischer-tropsch process. Fischer-Tropsch processes use Fischer-Tropsch catalysts to produce hydrocarbons from gases containing hydrogen and carbon monoxide. These hydrocarbons may require further processing in order to be useful as base oils. For example, the hydrocarbons may be dewaxed, hydroisomerized, and/or hydrocracked using methods known to those of ordinary skill in the art.

In further embodiments, the base oil comprises unrefined oils, refined oils, rerefined oils, or mixtures thereof. Unrefined oils are those obtained directly from a natural or synthetic source without further purification treatment. Non-limiting examples of unrefined oils include a shale oil obtained directly from a retorting operation, a petroleum oil obtained directly from primary distillation, and an ester oil obtained directly from an esterification process and used without further treatment. Refined oils are similar to unrefined oils except that the former have been further treated by one or more purification methods to improve one or more properties. Many such purification methods are known to those skilled in the art, such as solvent extraction, secondary distillation, acid or base extraction, filtration, diafiltration, and the like. Rerefined oils are obtained by applying a process similar to that used to obtain refined oils to refined oils. Such rerefined oils are also known as reclaimed or reprocessed oils and often are additionally processed by methods directed to removal of spent additives and oil breakdown products.

Anti-fatigue additive

The lubricating oil compositions herein contain an anti-fatigue additive. The anti-fatigue additive is an alkyl polyol, wherein the alkyl polyol has 2 to 20 carbon atoms, such as 2 to 19 carbon atoms, 2 to 18 carbon atoms, 2 to 17 carbon atoms, 2 to 16 carbon atoms, 2 to 15 carbon atoms, 2 to 14 carbon atoms, 2 to 13 carbon atoms, 2 to 12 carbon atoms, 2 to 11 carbon atoms, 2 to 10 carbon atoms, 2 to 9 carbon atoms, and 2 to 8 carbon atoms. The alkyl polyol contains 2 or more alcohol groups, such as 3 or more alcohol groups, 4 or more alcohol groups, and 5 or more alcohol groups. The term "alkyl" as used herein includes, unless otherwise specified, C1 to C20 saturated straight chain hydrocarbons, branched chain hydrocarbons, cyclic hydrocarbons, primary hydrocarbons, secondary hydrocarbons, or tertiary hydrocarbons.

Suitable alkyl polyols include glycerol, ethylene glycol, 3-amino-1, 2-propanediol, 1,2, 4-butanetriol, 1, -tris (hydroxymethyl) propane, meso-erythritol, D-sorbitol, xylitol, 2-diethyl-1, 3-propanediol, 3-methoxy-1, 2, -propanediol, 2-dimethyl-1, 3-propanediol, pentaerythritol and polyvinyl alcohol. Suitable cyclic alkyl polyols include inositol, D- (+) -xylose, and D- (+) -glucose. Other alkyl polyols include alcohol ethers such as diglycerol, triglycerol, diethylene glycol, triethylene glycol, dipentaerythritol, and tripentaerythritol.

In some embodiments, the alkyl polyol is added to the lubricating oil composition in an amount such that the fatigue time of the lubricating oil composition is increased over a comparable oil without the alkyl polyol according to the ZF bearing pitting test.

The exact amount of anti-fatigue additive may vary depending on the composition and amount of oil or lubricating viscosity, the particular detergent and amount, and other desired characteristics of the lubricating oil composition. In some embodiments, the amount of the anti-fatigue additive is at least about 0.001, or at least about 0.05, or at least about 0.1, or at least about 0.3, or at least about 0.4, or at least about 0.5, or at least about 0.75, or at least about 1.0 wt.% up to about 1.5, or up to about 1.25, or up to about 1.0, or up to about 0.9, or up to about 0.8 wt.%, based on the total weight of the lubricating oil composition.

Detergent

The lubricating oil composition comprises a metal sulfonate detergent. The metal may be any metal suitable for use in preparing the sulphonate detergent. Non-limiting examples of suitable metals include alkali metals, alkaline earth metals, and transition metals. In some embodiments, the metal is Ca, mg, ba, K, na, li or the like.

Typically, the amount of detergent is from about 0.001 wt.% to about 10 wt.%, from about 0.05 wt.% to about 3 wt.%, or from about 0.1 wt.% to about 1 wt.%, based on the total weight of the lubricating oil composition.

Optionally, the lubricating oil composition may contain additional detergents generally known in the art. Some suitable detergents have been described in the following documents: mortier et al, "CHEMISTRY AND Technology of Lubricants", 2 nd edition, london, springer, chapter 3, pages 75-85 (1996); and Leslie R.Rudnick, "Lubricant Additives: CHEMISTRY AND Applications," New York, MARCEL DEKKER, chapter 4, pages 113-136 (2003), all of which are incorporated herein by reference. Examples of such detergents include phenates, salicylates, phosphonates, and the like.

In some embodiments, the detergent comprises at least one overbased (TBN above 250 on an active basis) sulfonate detergent, such as an overbased calcium sulfonate.

Overbased metal detergents are typically produced by carbonating a mixture of a hydrocarbon, a detergent acid (e.g., sulfonic acid, alkyl hydroxybenzoate, etc.), a metal oxide or hydroxide (e.g., calcium oxide or calcium hydroxide), and an accelerator such as xylene, methanol, and water. For example, to prepare overbased calcium sulfonates, calcium oxide or hydroxide is reacted with gaseous carbon dioxide to form calcium carbonate during carbonation. The sulfonic acid is neutralized with excess CaO or Ca (OH) ₂ to form the sulfonate salt.

In general, the overbased detergent may be low overbased, such as an overbased salt having a TBN of less than 100 on an active basis. In one aspect, the low overbased salt may have a TBN of about 10 to about 100. In another aspect, the low overbased salt may have a TBN of about 10 to about 80. The overbased detergent may be a Medium Overbased (MOB), such as an overbased salt having a TBN of about 100 to about 250 on an active basis. In one aspect, the TBN of the medium overbased salt may be from about 100 to about 200. In another aspect, the TBN of the medium overbased salt may be from about 125 to about 175. The overbased detergent may be an overbased (HOB), for example an overbased salt having a TBN above 250 on an active basis. In one aspect, the TBN of the overbased salt may be from about 250 to about 800, based on the active substance.

In some embodiments, the lubricating oil composition comprises a low level of sulfur-containing calcium phenate (e.g., about 40 mmoles or less of Ca from sulfurized phenates, such as 35 mmoles or less, 30 mmoles or less, 25 mmoles or less, 20 mmoles or less, 10 mmoles or less, 5 mmoles or less, and 0 mmoles).

Other additives

Optionally, the lubricating oil composition may further comprise additives or modifiers (hereinafter "additives") that may at least impart or improve any desired properties of the lubricating oil composition. Any additive known to one of ordinary skill in the art may be used in the lubricating oil compositions disclosed herein. Some suitable additives are described in Mortier et al, "CHEMISTRY AND Technology of Lubricants", 2 nd edition, london, springer, (1996) and Leslie R.Rudnick, "Lubricant Additives: CHEMISTRY AND Applications", new York, MARCEL DEKKER (2003), all of which are incorporated herein by reference. In some embodiments, the additive may be selected from the group consisting of: antioxidants, antiwear agents, detergents, rust inhibitors, demulsifiers, friction modifiers, multi-functional additives, viscosity index improvers, pour point depressants, foam inhibitors, metal deactivators, dispersants, corrosion inhibitors, lubricity improvers, thermal stability improvers, anti-mist additives, icing inhibitors, dyes, markers, static dissipative agents, biocides, and combinations thereof.

A particularly suitable combination of additives comprises an anti-fatigue additive in the amounts described above; dispersant additives such as ethylene carbonate post-treated bissuccinimide; antiwear additives such as zinc dialkyldithiophosphates, such as zinc dialkyldithiophosphates derived from primary alcohols; and the above detergent compositions comprising at least one overbased sulfonate detergent (e.g., overbased calcium sulfonate). Optionally, the lubricating oil composition may comprise an additional detergent (e.g., a phenate detergent). The zinc dialkyldithiophosphate is a primary alkyl zinc dialkyldithiophosphate, a secondary alkyl zinc dialkyldithiophosphate, or a combination thereof, and may be present at 3 wt.% or less (e.g., 0.1 wt.% to 1.5 wt.%, or 0.5 wt.% to 1.0 wt.%) of the lubricating oil composition. Dispersants such as ethylene carbonate post-treated bissuccinimide may be present in an amount of 0.1 wt.% to 10 wt.% (e.g., 0.5 wt.% to 8 wt.%, 0.7 wt.% to 7 wt.%, 0.7 wt.% to 6 wt.%, 0.7 wt.% to 5 wt.%, 0.7 wt.% to 4 wt.%) based on the total weight of the lubricating oil composition.

Generally, when used, the concentration of each additive in the lubricating oil composition can be in the range of from about 0.001 wt.% to about 10 wt.%, from about 0.01 wt.% to about 5 wt.%, or from about 0.1 wt.% to about 2.5 wt.%, based on the total weight of the lubricating oil composition. Further, the total amount of additives in the lubricating oil composition may range from about 0.001 wt.% to about 20 wt.%, from about 0.01 wt.% to about 10 wt.%, or from about 0.1 wt.% to about 5 wt.%, based on the total weight of the lubricating oil composition.

Antiwear agent

Optionally, the lubricating oil compositions disclosed herein may comprise one or more antiwear agents. In some embodiments, the lubricating oil composition is free or substantially free of sulfur-containing antiwear compositions.

Antiwear agents reduce wear of metal parts. Suitable antiwear agents include metal dihydrocarbyl dithiophosphates such as Zinc Dihydrocarbyl Dithiophosphate (ZDDP) having the following structure:

Zn[S-P(＝S)(OR¹)(OR²)]₂

Wherein R ¹ and R ² may be the same or different hydrocarbyl groups having from 1 to 18 (e.g., 2 to 12) carbon atoms and include groups such as alkyl, alkenyl, aryl, aralkyl, alkaryl, and cycloaliphatic groups. Particularly preferred as the groups of R ¹ and R ² are alkyl groups having 2 to 8 carbon atoms (for example, alkyl groups may be ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, n-pentyl, isopentyl, n-hexyl, isohexyl, 2-ethylhexyl). To obtain oil solubility, the total number of carbon atoms (i.e., R ¹+R²) is at least 5. Thus, the zinc dihydrocarbyl dithiophosphate can include zinc dialkyl dithiophosphate. The zinc dialkyldithiophosphate is a primary alkyl-type zinc dialkyldithiophosphate, a secondary alkyl-type zinc dialkyldithiophosphate, or a combination thereof. ZDDP may be present at 3 wt.% or less (e.g., 0.1 wt.% to 1.5 wt.%, or 0.5 wt.% to 1.0 wt.%) of the lubricating oil composition.

Dispersing agent

Optionally, the lubricating oil compositions disclosed herein may also contain a dispersant. The dispersant remains in the oil-insoluble suspended material resulting from oxidation during engine operation, thereby preventing sludge flocculation and precipitation or deposition on the metal parts. Dispersants useful herein include nitrogen-containing, ash-free (metal-free) dispersants that are known to be effective in reducing deposit formation when used in gasoline and diesel engines. Suitable dispersants include hydrocarbyl succinimides, hydrocarbyl succinamides, mixed esters/amides of hydrocarbyl-substituted succinic acids, hydroxy esters of hydrocarbyl-substituted succinic acids, and Mannich condensation products of hydrocarbyl-substituted phenols, formaldehyde and polyamines. Condensation products of polyamines and hydrocarbyl-substituted phenyl acids are also suitable. Mixtures of these dispersants may also be used.

Basic nitrogen-containing ashless dispersants are well known lubricating oil additives, and methods for their preparation are widely described in the patent literature. Preferred dispersants are alkenyl succinimides and succinamides in which the alkenyl substituent is a long chain preferably greater than 40 carbon atoms. These materials are readily prepared by reacting a hydrocarbyl-substituted dicarboxylic acid material with a molecule containing an amine functional group. Examples of suitable amines are polyamines, such as polyalkylene polyamines, hydroxy-substituted polyamines and polyoxyalkylene polyamines. The dispersant may be post-treated (e.g., with a borating agent, ethylene carbonate, or cyclic carbonate) as is known in the art. Nitrogen-containing ashless (metal-free) dispersants are basic and contribute to the TBN of lubricating oil compositions to which they are added without introducing additional sulfated ash. The dispersant may be present at 0.1 wt.% to 10 wt.% (e.g., 0.5 wt.% to 8 wt.%, 0.7 wt.% to 7 wt.%, 0.7 wt.% to 6 wt.%, 0.7 wt.% to 5 wt.%, 0.7 wt.% to 4 wt.%) of the lubricating oil composition based on the active level. Nitrogen from the dispersant is present at greater than 0.0050 wt% to 0.30 wt% (e.g., greater than 0.0050 wt% to 0.10 wt%, 0.0050 wt% to 0.080 wt%, 0.0050 wt% to 0.060 wt%, 0.0050 wt% to 0.050 wt%, 0.0050 wt% to 0.040 wt%, 0.0050 wt% to 0.030 wt%) based on the weight of dispersant in the finished oil.

Antioxidant agent

Optionally, the lubricating oil compositions disclosed herein may also contain additional antioxidants that may reduce or prevent oxidation of the base oil. Any antioxidant known to those of ordinary skill in the art may be used in the lubricating oil composition. Non-limiting examples of suitable antioxidants include amine-based antioxidants (e.g., alkyl diphenylamines, phenyl-alpha-naphthylamines, alkyl or aralkyl substituted phenyl-alpha-naphthylamines, alkylated p-phenylenediamine, tetramethyl-diaminodiphenylamines, and the like), phenolic antioxidants (e.g., 2-t-butylphenol, 4-methyl-2, 6-di-t-butylphenol, 2,4, 6-tri-t-butylphenol, 2, 6-di-t-butyl-p-cresol, 2, 6-di-t-butylphenol, 4' -methylenebis- (2, 6-di-t-butylphenol), 4' -thiobis (6-di-t-butyl-o-cresol), and the like), sulfur-based antioxidants (e.g., dilauryl-3, 3' -thiodipropionate, sulfurized phenolic antioxidants, and the like), phosphorus-based antioxidants (e.g., phosphites, and the like), zinc dithiophosphate, oil-soluble copper compounds, and combinations thereof. The amount of antioxidant may vary from about 0.01 wt.% to about 10wt.%, from about 0.05 wt.% to about 5 wt.%, or from about 0.1 wt.% to about 3 wt.%, based on the total weight of the lubricating oil composition. Leslie R.Rudnick, "Lubricant Additives: CHEMISTRY AND Applications", new York. Marcel Dekker, chapter 1, pages 1-28 (2003), incorporated herein by reference, describes some suitable antioxidants.

Friction modifiers

The lubricating oil compositions disclosed herein may optionally contain a friction modifier that reduces friction between moving parts. Any friction modifier known to those of ordinary skill in the art may be used in the lubricating oil composition. Non-limiting examples of suitable friction modifiers include fatty carboxylic acids: derivatives of fatty carboxylic acids (e.g., alcohols, esters, borates (borated ester), amides, metal salts, and the like); mono-, di-or tri-alkyl substituted phosphoric or phosphonic acids; derivatives (e.g., esters, amides, metal salts, etc.) of mono-, di-, or tri-alkyl substituted phosphoric or phosphonic acids; mono-, di-or tri-alkyl substituted amines; mono-or di-alkyl substituted amides and combinations thereof. In some embodiments, the friction modifier is selected from the group consisting of: aliphatic amines, ethoxylated aliphatic amines, aliphatic carboxylic acid amides, ethoxylated aliphatic ether amines, aliphatic carboxylic acids, glycerides, aliphatic carboxylic acid ester amides, aliphatic imidazolines, aliphatic tertiary amines, wherein the aliphatic or aliphatic group contains more than about eight carbon atoms, thereby imparting suitable oil solubility to the compound. In other embodiments, the friction modifier comprises an aliphatic substituted succinimide formed by reacting an aliphatic succinic acid or anhydride with ammonia or a primary amine. The amount of friction modifier may vary from about 0.01 wt.% to about 10 wt.%, from about 0.05 wt.% to about 5 wt.%, or from about 0.1 wt.% to about 3 wt.%, based on the total weight of the lubricating oil composition. Some suitable friction modifiers have been described in the following documents: mortier et al, "CHEMISTRY AND Technology of Lubricants", 2 nd edition, london, springer, chapter 6, pages 183-187 (1996); and Leslie R.Rudnick, "Lubricant Additives: CHEMISTRY AND Applications", new York, MARCEL DEKKER, chapters 6 and 7, pages 171-222 (2003), all of which are incorporated herein by reference.

Pour point depressant

The lubricating oil compositions disclosed herein may optionally comprise a pour point depressant that can reduce the pour point of the lubricating oil composition. Any pour point depressant known to one of ordinary skill in the art may be used in the lubricating oil composition. Non-limiting examples of suitable pour point depressants include polymethacrylates, alkyl acrylate polymers, alkyl methacrylate polymers, di (tetra-alkylphenol) phthalate, condensates of tetra-alkylphenol, condensates of chlorinated paraffin with naphthalene, and combinations thereof. In some embodiments, the pour point depressant includes ethylene vinyl acetate copolymers, condensates of chlorinated paraffins and phenol, polyalkylstyrenes, and the like. The amount of pour point depressant may vary from about 0.01 wt.% to about 10 wt.%, from about 0.05 wt.% to about 5 wt.%, or from about 0.1 wt.% to about 3 wt.%, based on the total weight of the lubricating oil composition. Some suitable pour point depressants have been described in the following documents: mortier et al, "CHEMISTRY AND Technology of Lubricants", 2 nd edition, london, springer, chapter 6, pages 187-189 (1996); and Leslie R.Rudnick, "Lubricant Additives: CHEMISTRY AND Applications", new York, MARCEL DEKKER, chapter 11, pages 329-354 (2003), all of which are incorporated herein by reference.

Demulsifier

The lubricating oil compositions disclosed herein may optionally include demulsifiers that can promote oil-water separation in the lubricating oil compositions that are exposed to water or steam. Any demulsifier known to those of ordinary skill in the art may be used in the lubricating oil composition. Non-limiting examples of suitable demulsifiers include anionic surfactants (e.g., alkyl naphthalene sulfonates, alkylbenzene sulfonates, etc.), nonionic alkoxylated alkylphenol resins, alkylene oxide polymers (e.g., polyethylene oxide, polypropylene oxide, block copolymers of ethylene oxide, propylene oxide, etc.), esters of oil-soluble acids, polyoxyethylene sorbitan esters, and combinations thereof. The amount of demulsifier may vary from about 0.01 wt.% to about 10 wt.%, from about 0.05 wt.% to about 5 wt.%, or from about 0.1 wt.% to about 3 wt.%, based on the total weight of the lubricating oil composition. Some suitable demulsifiers are described in Mortier et al, "CHEMISTRY AND Technology of Lubricants", 2 nd edition, london, springer, chapter 6, pages 190-193 (1996), which is incorporated herein by reference.

Foam inhibitors

The lubricating oil compositions disclosed herein may optionally contain foam inhibitors or defoamers that can disrupt the foam in the oil. Any foam inhibitor or defoamer known to those of ordinary skill in the art may be used in the lubricating oil composition. Non-limiting examples of suitable defoamers include silicone oils or polydimethylsiloxanes, fluorosilicones, alkoxylated aliphatic acids, polyethers (e.g., polyethylene glycol), branched polyvinyl ethers, alkyl acrylate polymers, alkyl methacrylate polymers, polyalkoxyamines, and combinations thereof. In some embodiments, the defoamer comprises glycerol monostearate, polyethylene glycol palmitate, trialkyl monothiophosphates, sulfonated ricinoleate, benzoylacetone, methyl salicylate, glycerol monooleate, or glycerol dioleate. The amount of defoamer may vary from about 0.01 wt.% to about 5 wt.%, from about 0.05 wt.% to about 3 wt.%, or from about 0.1 wt.% to about 1 wt.%, based on the total weight of the lubricating oil composition. Some suitable defoamers are described in Mortier et al, "CHEMISTRY AND Technology of Lubricants", 2 nd edition, london, springer, chapter 6, pages 190-193 (1996), which is incorporated herein by reference.

Corrosion inhibitors

The lubricating oil compositions disclosed herein may optionally contain a corrosion inhibitor that may reduce corrosion. Any corrosion inhibitor known to those of ordinary skill in the art may be used in the lubricating oil composition. Non-limiting examples of suitable corrosion inhibitors include half esters or amides of dodecyl succinic acid, phosphate esters, thiophosphate esters, alkyl imidazolines, sarcosine, and combinations thereof. The amount of corrosion inhibitor may vary from about 0.01 wt.% to about 5 wt.%, from about 0.05 wt.% to about 3 wt.%, or from about 0.1 wt.% to about 1 wt.%, based on the total weight of the lubricating oil composition. Some suitable corrosion inhibitors are described in Mortier et al, "CHEMISTRY AND Technology of Lubricants", 2 nd edition, london, springer, chapter 6, pages 193-196 (1996), which is incorporated herein by reference.

Extreme pressure agent

The lubricating oil compositions disclosed herein may optionally comprise Extreme Pressure (EP) agents that may prevent sliding metal surfaces from seizing under extreme pressure conditions. Any extreme pressure agent known to one of ordinary skill in the art may be used in the lubricating oil composition. Typically, extreme pressure agents are compounds that can chemically bond with metals to form surface films that prevent welding against asperities in the metal surface under high loads. Non-limiting examples of suitable extreme pressure agents include sulfurized animal or vegetable fats or oils, sulfurized animal or vegetable fatty acid esters, fully or partially esterified esters of trivalent or pentavalent acids of phosphorus, sulfurized olefins, dialkyl polysulfides, sulfurized diels-alder adducts (sulfurized Diels-Alder adduct), sulfurized dicyclopentadiene, sulfurized or co-sulfurized mixtures of fatty acid esters and monounsaturated olefins, co-sulfurized blends of fatty acids, fatty acid esters and alpha-olefins, functionally substituted dialkyl polysulfides, thioaldehydes, thioketones, episulfide compounds, sulfur acetal derivatives, co-sulfurized blends of terpenes and acyclic olefins, and polysulfide olefin products, amine salts of phosphoric or thiophosphoric esters, and combinations thereof. The amount of extreme pressure agent may vary from about 0.01 wt.% to about 5 wt.%, from about 0.05 wt.% to about 3 wt.%, or from about 0.1 wt.% to about 1 wt.%, based on the total weight of the lubricating oil composition. Leslie R.Rudnick, "Lubricant Additives: CHEMISTRY AND Applications", new York, MARCEL DEKKER, chapter 8, pages 223-258 (2003), incorporated herein by reference, describes some suitable extreme pressure agents.

Rust inhibitor

The lubricating oil compositions disclosed herein may optionally comprise rust inhibitors capable of inhibiting corrosion of ferrous metal surfaces. Any rust inhibitor known to those of ordinary skill in the art may be used in the lubricating oil composition. Non-limiting examples of suitable rust inhibitors include oil-soluble monocarboxylic acids (e.g., 2-ethylhexanoic acid, lauric acid, myristic acid, palmitic acid, oleic acid, linoleic acid, linolenic acid, behenic acid, cerotic acid, etc.), oil-soluble polycarboxylic acids (e.g., those prepared from tall oil fatty acids, oleic acid, linoleic acid, etc.), alkenyl succinic acids in which the alkenyl group contains 10 or more carbon atoms (e.g., tetrapropenyl succinic acid, tetradecenyl succinic acid, hexadecenyl succinic acid, etc.); long chain alpha, omega-dicarboxylic acids having a molecular weight in the range of 600 to 3000 daltons, and combinations thereof. The amount of rust inhibitor may vary from about 0.01 wt.% to about 10 wt.%, from about 0.05 wt.% to about 5 wt.%, or from about 0.1 wt.% to about 3 wt.%, based on the total weight of the lubricating oil composition.

Other non-limiting examples of suitable rust inhibitors include nonionic polyoxyethylene surfactants such as polyoxyethylene lauryl ether, polyoxyethylene higher alcohol ether, polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene octylstearyl ether, polyoxyethylene oleyl ether, polyoxyethylene sorbitol monostearate, polyoxyethylene sorbitol monooleate, and polyethylene glycol monooleate. Other non-limiting examples of suitable rust inhibitors include stearic acid and other fatty acids, dicarboxylic acids, metal soaps, fatty acid amine salts, metal salts of heavy sulfonic acids, partial carboxylic esters of polyols, and phosphoric esters.

Multifunctional additive

In some embodiments, the lubricating oil composition comprises at least a multi-functional additive. Some non-limiting examples of suitable polyfunctional additives include molybdenum sulfide dithiocarbamates, molybdenum sulfide organic dithiophosphates, molybdenum oxide monoglycerides, molybdenum oxide diacetic amides, amine-molybdenum complexes, and sulfur-containing molybdenum complexes.

Viscosity index improver

In certain embodiments, the lubricating oil composition comprises at least one viscosity index improver. Some non-limiting examples of suitable viscosity index improvers include polymethacrylate polymers, ethylene-propylene copolymers, styrene-isoprene copolymers, hydrated styrene-isoprene copolymers, polyisobutylene, and dispersant viscosity index improvers.

Metal deactivator

In some embodiments, the lubricating oil composition comprises at least a metal deactivator. Some non-limiting examples of suitable metal deactivators include salicylidene propylene diamine, triazole derivatives, thiadiazole derivatives, and mercaptobenzimidazole.

Additive concentrate formulations

The additives disclosed herein may be in the form of an additive concentrate having more than one additive. The additive concentrate may comprise a suitable diluent, such as a hydrocarbon oil having a suitable viscosity. Such diluents may be selected from the group consisting of natural oils (e.g., mineral oils), synthetic oils, and combinations thereof. Some non-limiting examples of mineral oils include paraffinic, naphthenic, asphaltic, and combinations thereof. Some non-limiting examples of synthetic base oils include polyolefin oils (especially hydrogenated alpha-olefin oligomers), alkylated aromatics, polyalkylene oxides, aromatic ethers, and carboxylic acid esters (especially diester oils), and combinations thereof. In some embodiments, the diluent is a light hydrocarbon oil, either natural or synthetic. In general, diluent oils may have a viscosity of about 13 centistokes to about 35 centistokes at 40℃.

In general, it is desirable for the diluent to readily solubilize the lubricating oil soluble additives and provide an oil additive concentrate that is readily soluble in the lubricant base oil stock or fuel. Furthermore, it is desirable that the diluent not introduce any undesirable characteristics to the lubricant base oil stock, and thus ultimately to the finished lubricant or fuel, including, for example, high volatility, high viscosity, and impurities such as heteroatoms.

The present application also provides an oil-soluble additive concentrate composition comprising an inert diluent and from 2.0 to 90 wt%, preferably from 10 to 50 wt%, based on the total concentrate, of an oil-soluble additive composition of the present application.

Functional oil containing the above additives may be used in a method of increasing bearing fatigue time comprising contacting a metal surface with the functional oil.

The following examples are presented to illustrate embodiments but are not intended to limit the application to the specific embodiments set forth. All parts and percentages are by weight unless indicated to the contrary. All values are approximations. When numerical ranges are given, it should be understood that embodiments outside the stated ranges still fall within the scope of the application. Specific details described in each embodiment should not be construed as essential features.

Examples

The following examples are intended for illustrative purposes only and are not intended to limit the scope in any way.

ZF bearing pitting test

The ZF specification 03C bearing pitting test 0000 702 232 was used to evaluate bearing performance. The test used an FE8 roller thrust bearing with an axial force of 68kN and a rotational speed of 300rpm. The temperature was 100 ℃. In this test, the length of the failure time was measured and determined to be a failure when the vibration became so severe that metal fragments were shed from the bearing or the housing in contact with the bearing and the FE8 test stand was automatically closed. The detached metal may leave pockets in the bearing or housing. To pass the ZF 03C specification test, the minimum fault duration was 300 hours. The maximum amount of time allowed for the test run was 750 hours. ZF bearing pitting test is available from Assmann Laboratories, aachen, germany.

Benchmark formulations

The baseline formulation included the following:

(i) 1% by weight of an ethylene carbonate end-capped dispersant;

(ii) 1.28% by weight of a zinc dithiophosphate oil concentrate derived from a primary alcohol containing 7.3% by weight of phosphorus;

(iii) 0.79 wt.% 320TBN calcium sulfonate detergent oil concentrate;

(iv) 0.5 weight percent pour point depressant;

(v) 0.6 wt% seal swell additive;

(vi) 0.04 wt% of a foam inhibitor;

(vii) The balance is group II base oil with a viscosity of 10W.

Comparative example A

Comparative example a was prepared using the above reference formulation and adding 1.46% by weight (35 mmol Ca) of a highly overbased calcium phenate (TBN 263).

Comparative example B

Comparative example B was prepared using the above reference formulation and adding 1.88% by weight (45 mmol Ca) of highly sulfided overbased calcium phenate (TBN 263).

Comparative example C

Comparative example C was prepared using the above reference formulation and adding 2.29% by weight (55 mmol Ca) of highly sulfided overbased calcium phenate (TBN 263).

Table 1 summarizes comparative examples A, B and C. Table 1 also shows that in the absence of glycerol, a threshold amount of sulfurized phenate detergent is required to pass the ZF FE 8 bearing pitting test. Increasing the amount of sulfurized phenate improves the ZF test results.

TABLE 1

Examples 1 to 6

The lubricating oil composition was prepared using the above-described baseline formulation and adding 1.46 wt.% (35 mmol Ca) of a sulfurized highly overbased calcium phenate (TBN 263). Glycerin was added to the formulation at the weight% shown in table 2 below.

TABLE 2

Table 2 shows that, surprisingly and unexpectedly, the addition of glycerol at very low treat rates allows the ZF FE 8 bearing pitting test to pass even below the threshold level of sulfurized phenate. Increasing the glycerol treatment rate significantly improved the ZF test performance, maximizing the duration of the ZF test (750 hours).

Example 7

Example 7 was prepared using the above reference formulation and adding 1.04 wt% (25 mmol Ca) of highly sulfided overbased calcium phenate (TBN 263) and 0.25 wt% glycerol.

Example 8

Example 8 was prepared using the above reference formulation and adding 0.42 wt% (10 mmol Ca) of highly sulfided overbased calcium phenate (TBN 263) and 0.25 wt% glycerol.

Example 9

Example 9 was prepared using the above-described baseline formulation with the addition of 0.25 wt% glycerol.

Example 10

Example 10 was prepared using the above-described baseline formulation with the addition of 0.20 wt% glycerol.

Example 11

Example 11 was prepared using the above-described baseline formulation with the addition of 0.15 wt% glycerol.

Example 12

Example 12 was prepared using the above-described baseline formulation with the addition of 0.10 wt% glycerol.

Example 13

Example 13 was prepared using the above-described baseline formulation with the addition of 0.05 wt% glycerol.

Example 14

Example 14 was prepared using the above-described baseline formulation with the addition of 0.03 wt% glycerol.

Examples 7 to 14 are summarized in table 3 below.

TABLE 3 Table 3

As shown in table 3, the addition of glycerol allowed the ZF FE 8 bearing pitting test to pass at very low sulfurized phenate treatment rates or even in the complete absence of sulfurized phenate. In fact, only a very small amount of glycerol and complete removal of the sulfurized phenolate salt is required to achieve optimal ZF test performance.

Examples 15 to 19

Examples 15-19 were prepared using the above-described baseline formulation, in which no zinc dithiophosphate was present, and the weight% of glycerol is shown in table 4.

Surprisingly, improved bearing pitting results were also observed in samples containing little or no zinc dithiophosphate. In these samples, glycerol is essentially the only anti-fatigue component. This can be observed even in the case of very low glycerol contents (e.g. as low as 0.05% glycerol).

As shown in table 4, equivalent amounts of glycerol, especially at low treat rates, achieved performance in ZF FE 8 bearing pitting tests for up to 750 hours. In addition, for example, comparison of example 13 with 0.05 wt% glycerol and 1.28% zinc dithiophosphate gave a failed result of 252 hours, while equivalent zinc-free example 19 gave a maximum pass result of 750 hours.

TABLE 4 Table 4

It should be understood that various modifications may be made to the embodiments disclosed herein. Therefore, the above description should not be construed as limiting, but merely as exemplifications of embodiments of the application. For example, the functions described above and implemented for operation are for illustration purposes only. Other arrangements and methods may be implemented by those skilled in the art without departing from the scope and spirit of the application. Further, other modifications within the scope and spirit of the appended claims will occur to those skilled in the art.

Claims

1. A functional oil or EV oil, the oil comprising:

(a) A major amount of an oil of lubricating viscosity;

(b) An anti-fatigue additive comprising an alkyl polyol having 2 to 20 carbon atoms; and

(C) At least one overbased sulfonate detergent;

wherein the anti-fatigue additive is present in an amount of about 0.001 wt.% to about 1.5 wt.% based on the total weight of the functional oil or EV oil.

2. The functional oil or EV oil of claim 1, wherein the at least one overbased sulfonate detergent is an overbased calcium sulfonate.

3. The functional oil or EV oil of claim 1, further comprising a sulfurized calcium phenate detergent present in an amount that provides about 40mmol or less of calcium.

4. The functional oil or EV oil of claim 1, wherein the functional oil further comprises at least one dispersant additive.

5. The functional oil or EV oil of claim 4, wherein the at least one dispersant additive is ethylene carbonate post-treated bissuccinimide.

6. The functional oil or EV oil of claim 1, further comprising at least one antiwear additive.

7. The functional oil or EV oil of claim 6, wherein the at least one antiwear additive is zinc dialkyldithiophosphate.

8. The functional oil or EV oil of claim 7, wherein the zinc dialkyldithiophosphate is derived from a primary alcohol.

9. The functional oil or EV oil of claim 1, wherein the anti-fatigue additive is glycerol, triglycerol, 1,2, 4-butanetriol, 2-diethyl-1, 3-propanediol, diglycerol, 3-methoxy-1, 2-propanediol, inositol, meso-erythritol, D-sorbitol, xylitol, D- (+) -xylose, D- (+) -glucose, pentaerythritol, dipentaerythritol, tripentaerythritol, ethylene glycol, diethylene glycol, triethylene glycol, 2-dimethyl-1, 3-propanediol, or polyvinyl alcohol.

10. The functional oil or EV oil of claim 1, wherein the functional oil or EV oil comprises 3 wt% or less zinc dithiophosphate based on the total weight of the functional oil or EV oil.

11. A method of increasing bearing fatigue time, the method comprising contacting a metal surface with a functional oil or EV oil, the oil comprising:

a) A major amount of an oil of lubricating viscosity;

(C) At least one overbased sulfonate detergent; wherein the anti-fatigue additive is present in an amount of about 0.001 wt% to about 1.5 wt%.

12. The method of claim 11, wherein the at least one overbased sulfonate detergent is an overbased calcium sulfonate.

13. The method of claim 11, wherein the functional oil or EV oil further comprises a sulfurized calcium phenate detergent, the detergent being present in an amount to provide about 40mmol or less of calcium.

14. The method of claim 11, wherein the functional oil or EV oil further comprises at least one dispersant additive.

15. The method of claim 11, wherein the anti-fatigue additive is glycerol, triglycerol, 1,2, 4-butanetriol, 1, -tris (hydroxymethyl) propane, 2-diethyl-1, 3-propanediol, diglycerol, 3-methoxy-1, 2, -propanediol, inositol, meso-erythritol, D-sorbitol, xylitol, D- (+) -xylose, D- (+) -glucose, pentaerythritol, dipentaerythritol, tripentaerythritol, ethylene glycol, diethylene glycol, triethylene glycol, 2-dimethyl-1, 3-propanediol, or polyvinyl alcohol.

16. The method of claim 11, wherein the functional oil or EV oil comprises less than 3 wt% zinc dithiophosphate based on the total weight of the functional oil or EV oil.

17. A lubricating oil composition for a hybrid vehicle or plug-in hybrid vehicle, the lubricating oil composition comprising:

(a) A major amount of an oil of lubricating viscosity;

(C) At least one overbased sulfonate detergent;

Wherein the anti-fatigue additive is present in an amount of about 0.001 wt.% to about 1.5 wt.% based on the total weight of the lubricating oil composition.

18. The lubricating oil composition of claim 17, wherein the at least one overbased sulfonate detergent is an overbased calcium sulfonate.

19. The lubricating oil composition of claim 17, wherein the lubricating oil composition comprises 3 wt.% or less zinc dithiophosphate based on the total weight of the lubricating oil composition.

20. The lubricating oil composition of claim 17, wherein the lubricating oil composition comprises a calcium phenate detergent in an amount that provides about 40 mmoles or less of calcium.