Durable Magnet Wire and Lubricating Fluids for Electric and Hybrid Vehicle Applications

Abstract

To provide a drive line for an electric or hybrid-electric vehicle including an electric motor with an insulated magnet wire, and a lubricating and cooling fluid configured to maintain the durability of the magnet wire.SOLUTION: A drive line comprises: an electric motor including an insulated magnet wire having an insulation coating thereon with a thermal rating of about 190°C to about 210°C; and a lubricating and cooling fluid in contact with the insulation coating of the insulated magnet wire of the electric motor. The lubricating and cooling fluid includes a detergent system providing at least about 50 ppm metal to the fluid and a base oil system including a first base oil of lubrication viscosity blended with an ester base oil. The base oil system includes at least about 20 wt.% of the ester base oil, and a ratio of the metal provided by the detergent system to mol percent of ester groups in the base oil system of the lubricating and cooling fluid of about 70 or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to a driveline for an electric or hybrid-electric vehicle including an electric motor having insulated magnet wire and a lubricating composition in contact with the insulated magnet wire that is effective to provide improved durability of the insulated magnet wire. [Background technology]

[0002] Electric and hybrid-electric vehicles may contain a power source (a conventional combustion engine, such as a gasoline or diesel engine, and / or a battery source coupled to an electric motor) combined with a driveline and / or transmission for transmitting power to the wheels of the vehicle. The driveline and / or transmission may include an electric motor and / or a gear reduction unit coupled to the wheels. In some applications, a lubricant containing a lubricant composition for lubricating both the electric motor and / or gearing in the driveline or the power gear reduction unit is provided.

[0003] In electric and hybrid-electric vehicle applications, lubricating fluids may be in contact with wires or components of electric motors, as well as components of drivelines, transmissions, and / or conventional combustion engine gear reduction units. Therefore, suitable fluids must have applicability for fairly specific types of vehicle components. For example, lubricating fluids may be in contact with magnet wires found in motor stators and gears in the mechanical portions of the drivelines or transmissions. Therefore, suitable fluids for these applications must not only have traditional lubricating properties, but also be compatible with electronic components and the insulating layers of such electronic components.

[0004] Previous lubricants for transmissions typically required low friction and antiwear capabilities, thermal and oxidative stability, and detergency and dispersancy capabilities. To achieve such properties, conventional lubricants generally included a base oil and various additives, such as antioxidants, detergents, dispersants, antiwear agents, rust inhibitors, metal deactivators, friction modifiers, antifoam agents, seal swell agents, and / or viscosity index improvers, to name just a few conventional lubricant additives.

[0005] To be suitable for electrical components, a fluid generally must provide good lubrication, electrical conductivity, and / or cooling performance, as well as be compatible with the insulating coating of any electrical wires or other components with which the fluid may come into contact. Often, one or more of the desired properties required for electric and hybrid-electric applications are impaired due to the assemblage of additives commonly used in such conventional lubricating fluids, making the conventional lubricating fluid unsuitable for electric or hybrid-electric vehicles for one or more reasons. For example, some conventional lubricant packages may have low electrical conductivity but poor thermal conductivity (providing poor cooling performance), which would be undesirable for electric or hybrid applications. Other conventional lubricant packages may have high thermal conductivity (providing good cooling capacity) but poor electrical conductivity, which would also be undesirable for electric or hybrid applications. Still other conventional lubricant compositions may attack or destroy the insulation provided on the electrical wires or components, degrading the performance of such electrical components over time, as evidenced by poor or reduced wire breakdown voltage after fluid aging. Thus, prior art conventional driveline lubricating fluids do not always provide the performance desired for these unique applications in the context of electric or hybrid-electric drivelines. [Brief explanation of the drawings]

[0006] [Figure 1]1 is a plot of magnet wire breakdown voltage versus metal content of a lubricating and cooling fluid and mole percent of ester groups in the base oil system of the lubricating fluid. Summary of the Invention

[0007] The present disclosure relates to a driveline for an electric or hybrid-electric vehicle. In one approach or embodiment, the driveline includes an electric motor including an insulated magnet wire with an insulating coating having a thermal rating of about 190°C to about 210°C, and a lubricating and cooling fluid in contact with the insulating coating of the insulated magnet wire of the electric motor. In some aspects of this embodiment, the lubricating and cooling fluid includes a detergent system providing at least about 50 ppm of metals to the fluid and a base oil system including a first base oil of lubricating viscosity blended with an ester base oil. In this approach, the base oil system may also include at least about 20 weight percent ester base oil, and the ratio of metals provided by the detergent system to mole percent of ester groups in the base oil system of the lubricating and cooling fluid is about 70 or less.

[0008] In other approaches or embodiments of the driveline, the driveline may also include several optional embodiments in any combination. These optional approaches or embodiments of the driveline include: the insulating coating of the magnet wire includes one or more layers, and the layer in contact with the lubricating and cooling fluid includes polyamide, polyimide, poly(amide / imide), combinations thereof, blends thereof, or copolymers thereof; and / or the magnet wire has an AWG gauge of 14 to 30; and / or the magnet wire is copper; and / or the insulated magnet wire in contact with the lubricating and cooling fluid has a breakdown voltage of about 10,000 volts or more; and / or the ester base oil includes a branched diester; and / or the branched diester is a reaction product of one or more dicarboxylic acids having an internal carbon chain length of 6 to 10 and one or more alcohols having a branched carbon chain length of 6 to 12 carbons; and / or the ester base oil is a carboxylic acid having a structure represented by Formula I: [ka] wherein R1 is a carbon chain having m-2 carbons, m is an integer from 6 to 10, R2 and R3 are the same or different and comprise a C8 to C20 linear or branched alkyl chain, n is an integer from 0 or 1, and / or n is 1, R2 and R3 are the same or different and comprise a C8 to C10 branched alkyl chain; and / or the ester base oil is a dibasic ester based on bi(6-methylheptyl)adipate, a dibasic ester based on bis(8-methylnonyl)adipate, or a linear monoester having about 16 to about 18 carbons in the acid portion and about 20 linear carbons in the alcohol portion. , linear monoesters having the formula (I), or combinations thereof; and / or the detergent system comprises an alkali or alkaline metal salt of a phenate, a sulfonate, a calixarate, a salixrate, a salicylate, a carboxylic acid, a sulfurized derivative thereof, or combinations thereof; and / or the alkali or alkaline metal comprises calcium, magnesium, potassium, sodium, lithium, barium, or mixtures thereof; and / or the detergent system provides 800 ppm or less of metals; and / or the first base oil of the base oil system is a mineral base oil or a synthetic base oil; and / or the first base oil of the base oil system is a polyalphaolefin.

[0009] In another approach or embodiment of the present disclosure, a driveline for a hybrid or hybrid electric vehicle includes an electric motor having insulated magnet wire with an insulating coating, the insulating coating comprising a polyamide, a polyimide, a poly(amide / imide), a combination thereof, a blend thereof, or a copolymer thereof in combination with a lubricating and cooling fluid in contact with the coating of the insulated magnet wire of the electric motor. In aspects of this embodiment, the lubricating and cooling fluid may include a detergent system providing at least about 50 ppm of metal to the fluid, and a base oil system including a first base oil of lubricating viscosity blended with an ester base oil, the base oil system including at least about 20 weight percent ester base oil.

[0010] In other approaches or embodiments of the driveline described in the previous paragraph, the driveline may also include several optional embodiments in any combination. These optional approaches or embodiments of the driveline include: a ratio of metal provided by the detergent system to mole percent of ester groups in the base oil system of about 70 or less; and / or the insulating coating of the magnet wire has a thermal rating of about 190°C to about 200°C; and / or the insulated magnet wire in contact with the lubricating and cooling fluid has a breakdown voltage of about 10,000 volts or more; and / or the ester base oil includes a branched diester; and / or the branched diester is a reaction product of one or more dicarboxylic acids having an internal carbon chain length of 6 to 10 and one or more alcohols having a branched carbon chain length of 6 to 12 carbons; and / or the ester base oil is a carboxylic acid represented by Formula I: [ka] wherein R1 is a carbon chain having m-2 carbon atoms, m is an integer from 6 to 10, R2 and R3 are the same or different and comprise a C8 to C20 linear or branched alkyl chain, n is an integer from 0 to 1, and / or n is 1, R2 and R3 are the same or different and comprise a C8 to C10 branched alkyl chain; and / or the ester base oil is a dibasic ester based on bi(6-methylheptyl)adipate, a dibasic ester based on bis(8-methylnonyl)adipate, or a linear monoester, the acid moiety of which is and / or the detergent system comprises an alkali or alkaline metal salt of a phenate, sulfonate, calixarate, salixrate, salicylate, carboxylic acid, sulfurized derivatives thereof, or combinations thereof; and / or the alkali or alkaline metal comprises calcium, magnesium, potassium, sodium, lithium, barium, or mixtures thereof; and / or the detergent system provides up to 800 ppm metal.

[0011] In a further approach or embodiment of the present disclosure, a method of lubricating a driveline and an electric motor is provided. In an aspect, the method includes lubricating the driveline and / or the electric motor with any of the embodiments of the lubricating and cooling fluids described herein, wherein the insulated magnet wire of the electric motor is in contact with the lubricating cooling fluid.

[0012] In yet another approach or embodiment, the use of any embodiment of the lubricating and cooling fluids herein to lubricate any embodiment of the driveline of a hybrid or hybrid electric vehicle described herein is described. In the approach, the use includes contacting at least the insulated magnet wire of an electric motor with any embodiment of the lubricating and cooling fluids herein to achieve the improved breakdown voltage described above. DETAILED DESCRIPTION OF THE INVENTION

[0013] The present disclosure describes systems including magnet wire with lubricating and cooling fluids suitable for electric and / or hybrid electric vehicle applications, specifically the drivelines and / or transmissions of those vehicles, where the lubricating and cooling fluid contacts the electric motors and / or hybrid electric motors and their components, such as the insulated magnet wire. The fluids herein exhibit not only good lubricating properties, but also good electrical properties and are compatible with the insulating coating layers of the magnet wire found in the electric motors of such vehicle applications.

[0014] In some aspects, the present disclosure includes a system having a driveline for an electric or hybrid electric vehicle, the driveline including at least one electric motor having one or more insulated magnet wires. Each magnet wire has thereon an insulating coating having a thermal rating of about 190°C to about 210°C. As will be understood by those skilled in the art, the thermal rating or thermal grade of the wire is based on ASTM D2307. This test is described in NEMA MW 1000, a standards publication from the National Electrical Manufacturers Association. In this approach, the insulating coating of the magnet wire may include one or more layers, with at least the outer layer in contact with the lubricating and cooling fluid comprising polyamide, polyimide, poly(amide / imide), combinations thereof, blends thereof, or copolymers thereof.

[0015] The driveline further includes a lubricating and cooling fluid in contact with the insulating coating of the magnet wire from the electric motor. To provide compatibility with the insulating coating of the magnet wire, the lubricating and cooling fluid includes a selected composition including, but not limited to, a detergent system providing the fluid with at least about 50 ppm of metals, and a selected base oil system including a first base oil of lubricating viscosity blended with an ester base oil. In some embodiments, the base oil system includes at least about 20 weight percent ester base oil, and the lubricating and cooling fluid has a ratio of metals provided by the detergent system to mole percent of ester groups in the base oil system of about 70 or less. Using such a fluid and magnet wire combination, the driveline system herein provides insulated magnet wire having a breakdown voltage of 10,000 volts or greater after aging (as further described below) when in contact with the lubricating and cooling fluid. As further explained below and shown in FIG. 1, lubricating and cooling fluids having such a unique relationship between metal and ester content surprisingly provide good compatibility with the insulating coating of the magnet wire, providing high levels of breakdown voltage and durability to the magnet wire insulation upon aging in the fluid.

[0016] Drivelines for electric and / or hybrid-electric vehicles all utilize electric motors. One feature of electric motors is magnet wire, which is used to exchange electrical energy with magnetic energy. As commonly understood, an electric motor includes one or more coils of magnet wire that become electromagnets when an electric current is passed through them. The electromagnets interact with permanent magnets to rotate the coils, thereby powering the motor. As an electric motor operates, it generates heat and must be lubricated and / or cooled. Thus, fluids commonly used in internal combustion engines are used in electric motors for similar cooling and lubrication purposes. However, as discussed in the Background section, conventional lubricants for internal combustion engines may not be compatible with the insulating coatings found on magnet wire, as conventional fluids tend to degrade the magnet wire coatings with aging, as evidenced by low measured breakdown voltages.

[0017] As used herein, breakdown voltage is defined as the AC breakdown voltage as specified in Sections 70-76 of ASTM D1676-17, measured on a six-wire strand using the parameters specified therein. The wires are twisted and prepared for this evaluation in accordance with Section 3.8.4 of ANSI NEMA Magnet Wire standard 1000-2018, and wire aging is performed by immersing the twisted wire in about 75 to about 100 grams of test fluid at about 150°C for about 5 days (120 hours), as further described below in the Examples. Water may be added to increase the severity of the test. Breakdown voltage may be measured using a Megger 1525 insulation resistance meter or equivalent.

[0018] Magnet wire:

[0019] The driveline systems herein include at least one electric motor and lubrication and cooling fluids. Each electric motor includes one or more coils of magnet wire. In embodiments, the magnet wire of the electric motors and drivelines of the systems herein may be 14-30 American Wire Gauge (AWG) copper or aluminum wire that is round, rectangular, or other shaped and coated with one or more insulation layers. The insulation layers, particularly the outer insulation layer of the wire, will contact the lubrication and cooling fluids of the vehicle driveline. The magnet wire often includes a polymer insulation layer that may include one or more distinct polymer compositions. These polymers may be blended into a single layer, or such polymers may be multiple concentric layers around the wire.

[0020] In embodiments, the magnet wire insulation coating may include a polymer or copolymer of polyvinyl alcohol-formaldehyde-polyvinyl acetate, polyurethane, polyamide, polyester, polyester-polyimide, polyamide-polyimide, and / or polyimide, or combinations thereof, in single or multiple coating layers. Preferably, the magnet wire of the drivelines and electric motors of the systems herein includes one or more coating layers of polyamide, polyimide, poly(amide / imide), polyamide-imide, or combinations thereof, blends thereof, or copolymers thereof. The insulated magnet wire has a thermal rating class, and the wire of the present disclosure typically has a thermal rating of at least 190°C, in some cases a thermal rating of 190°C to 210°C, and most preferably a thermal rating of 200°C. The outer surface of the magnet wire insulation coating contacts the lubricating and cooling fluid of the drivelines herein.

[0021] Lubricating and cooling fluids for drivelines

[0022] The driveline herein includes not only an electric motor and its associated magnet wire as described above, but also a lubricating and cooling fluid having a selected detergent system and a selected base oil system configured for magnet wire durability. These unique combinations of components provide magnet wire with high durability upon aging, as measured by high breakdown voltage. Each feature of the fluid is described in more detail below, but generally, the detergent system provides the fluid with at least about 50 ppm metal (preferably at least about 100 ppm metal, at least about 150 ppm metal, or at least about 200 ppm metal), and the base oil system includes a selected blend of one or more first base oils of lubricating viscosity combined with an ester base oil. In some embodiments, the fluids herein (i) may have at least about 20 weight percent ester base oil in the base oil system, and (ii) the lubricating and cooling fluids have a ratio of metals provided by the detergent system to mole percent of ester groups in the base oil system of no more than about 70, as generally shown in the chart of FIG. 1, to achieve high breakdown voltage durability.

[0023] Detergent System: The lubricants and coolants herein comprise a unique detergent system that provides select amounts of metals, such as calcium, magnesium, potassium, sodium, lithium, barium, or mixtures thereof (preferably calcium), and in some embodiments, select amounts of such metals relative to the mole percent of ester groups in the base oil system, to provide high breakdown voltage for driveline magnet wire.

[0024] In embodiments, the detergent system includes a detergent additive such as an alkali or alkali metal salt of a phenate, sulfonate, calixarate, salixrate, salicylate, carboxylic acid, sulfurized derivatives thereof, or combinations thereof. Preferably, the detergent is a phenate or sulfonate, and most preferably a sulfonate. Suitable detergents and methods for their preparation are described in more detail in numerous patent publications, such as U.S. Pat. No. 7,732,390 and the references cited therein, which are incorporated herein by reference. The lubricant compositions herein may contain from about 0.1 to about 5 weight percent of the detergent additive, and from about 0.15 to about 3 weight percent in other approaches, and from about 0.15 to 1.0 weight percent in still other approaches.

[0025] As noted above, and in some approaches, the detergent system provides a select amount of metal, and in some approaches, a select amount of calcium and / or magnesium. For example, the detergent system provides an amount of metal that is greater than about 50 ppm metal, and in other approaches, from about 50 ppm to about 800 ppm metal, from about 100 ppm to about 800 ppm metal, from about 150 to about 800 ppm metal, or from about 200 ppm to about 800 ppm metal, based on the total lubricating composition. In some approaches, the metal is preferably calcium and / or magnesium, most preferably calcium provided by a phenate and / or sulfonate, most preferably an overbased calcium sulfonate.

[0026] In one approach, suitable detergents in the system may include alkali or alkaline earth metal salts, such as calcium or magnesium, of petroleum sulfonic acids and long chain mono- or di-alkylaryl sulfonic acids in which the aryl groups are benzyl, tolyl, and xylyl, and / or various phenates or derivatives of phenates. Examples of suitable detergents include, but are not limited to, lowbased / neutral and overbased variations of the following detergents: calcium phenate, calcium sulfur-containing phenate, calcium sulfonate, calcium calixarate, calcium salixarate, calcium salicylate, calcium carboxylic acid, calcium phosphate, calcium mono- and / or di-thiophosphate, calcium alkyl phenol, calcium sulfur-bound alkyl phenol compound, calcium methylene bridged phenol, magnesium phenate, magnesium sulfur-containing phenate, magnesium sulfonate, magnesium calixarate, magnesium salixarate, magnesium salicylate, magnesium carboxylic acid, magnesium phosphate, magnesium mono- and / or di-thiophosphate, magnesium alkyl phenol, magnesium sulfur-bound alkyl phenol compound, magnesium methylene bridged phenol, sodium phenate, sodium sulfur-containing phenate, sodium sulfonate, sodium calixarate, sodium salixarate, sodium salicylate, sodium carboxylic acid, sodium phosphate, sodium mono- and / or di-thiophosphate, sodium alkyl phenol, sodium sulfur-bound alkyl phenol compound, or sodium methylene bridged phenol.

[0027] The detergent additive may be neutral, underbased, or overbased. As will be appreciated, overbased detergent additives are well known in the art and may be alkali or alkaline earth metal overbased 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, an aliphatic-substituted carboxylic acid, or an aliphatic-substituted phenol.

[0028] The term "overbased" 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 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 the acid to its "standard" or "neutral" salt). The expression "metal ratio," often abbreviated as MR, is used to indicate the ratio of the total chemical equivalents of metal in an overbased salt to the chemical equivalents of metal in a neutral salt, according to known chemical reactivity and stoichiometry. In standard or neutral salts, the MR is 1; in overbased salts, the MR is greater than 1. These are commonly referred to as overbased, highly based, or superbased salts and may be salts of organic sulfur acids, carboxylic acids, or phenols.

[0029] As used herein, the term "TBN" is used to represent a total base number in mg KOH / g as measured by the method of ASTM D2896. The overbased detergent of the lubricating oil composition may have a total base number (TBN) of about 200 mg KOH / gram or more, or 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. The overbased detergent may have a metal to substrate ratio of from 1.1:1, or from 2:1, or from 4:1, or from 5:1, or from 7:1, or from 10:1.

[0030] Examples of suitable overbased detergents include, but are not limited to, overbased calcium phenate, overbased calcium sulfur-containing phenate, overbased calcium sulfonate, overbased calcium calixarate, overbased calcium salixarate, overbased calcium salicylate, overbased calcium carboxylic acid, overbased calcium phosphate, overbased calcium mono- and / or dithiophosphate, overbased calcium alkylphenol, overbased calcium sulfur-bound alkylphenol compound, overbased calcium methylene-bridged phenol, overbased magnesium phenate, overbased magnesium sulfonate, overbased magnesium calixarate, overbased magnesium salixarate, overbased magnesium salicylate, overbased magnesium carboxylic acid, overbased magnesium phosphate, overbased magnesium and / or dithiophosphate, overbased magnesium alkylphenol, overbased magnesium sulfur-bound alkylphenol compound, or overbased magnesium methylene-bridged phenol.

[0031] When a low-based or neutral detergent is incorporated into the detergent system, the low-based or neutral detergent generally has a TBN of up to 175 mg KOH / g, up to 150 mg KOH / g, up to 100 mg KOH / g, or up to 50 mg KOH / g. The low-based / neutral detergent may include a calcium- or magnesium-containing detergent. Examples of suitable low-based / neutral detergents include, but are not limited to, calcium sulfonate, calcium phenate, calcium salicylate, magnesium sulfonate, magnesium phenate, and / or magnesium salicylate.

[0032] In some embodiments, the detergents used in the driveline fluids herein are neutral or low-based calcium sulfonates or calcium phenates having a total base number of about 0 to about 100, and in other approaches, about 0 to about 50. In another approach, the detergents used in the driveline fluids herein are overbased calcium sulfonates or calcium phenates having a total base number of 150 to 400, and in other approaches, about 200 to about 350. In yet another approach, the detergents used in the driveline fluids herein may be magnesium sulfonates or magnesium phenates, and when magnesium sulfonates are incorporated into the detergent system, the magnesium sulfonates may be overbased detergents having a total base number of 300 to 500, and in other approaches, about 350 to about 450. The TBN values above reflect the values of the finished detergent components diluted in the base oil.

[0033] In other embodiments, the TBN of the detergents herein may reflect the neat or undiluted version of the detergent component. For example, the fluids herein may include a neutral to low-based calcium sulfonate as a neat (or undiluted) additive having a TBN of 0 to about 80, and in other approaches, about 20 to about 80. An overbased calcium sulfonate or calcium phenate as a neat additive may have a TBN of about 300 to about 450, and in other approaches, about 380 to about 420. An overbased magnesium sulfonate as a neat additive may have a TBN of about 500 to about 700, and in other approaches, about 600 to about 700. Preferably, the detergent systems herein include an overbased calcium sulfonate detergent providing about 50 to about 800 ppm of calcium.

[0034] Base Oil System: In other aspects or embodiments, the lubricating and cooling fluids disclosed herein comprise a unique base oil system comprising (i) a first base oil of lubricating viscosity selected from one or more API Group I to Group V base oils, blended with (ii) a select amount of an ester base oil. In some embodiments, the base oil system herein comprises an API Group I, II, and / or III mineral base oil as the first base oil combined with the ester base oil. In another approach, the base oil system herein comprises an API Group IV polyalphaolfin base oil as the first base oil combined with the ester base oil. In any of the above embodiments, the base oil system comprises at least about 20 weight percent of the ester base oil. As described in more detail below, the ester base oil of the fluids herein is the reaction product of one or more carboxylic or dicarboxylic acids having specific internal carbon chain lengths with one or more alcohols having specific linear or branched carbon chain lengths, providing the fluid with a specified amount of ester functionality. Thus, when blended with detergent systems within the above relationship of metal to ester groups, the drivelines and electric motors herein have very high levels of magnet wire durability in the context of breakdown voltage.

[0035] Ester Base Oil of the Base Oil System: One component of the lubricating and cooling fluids herein is a base oil system comprising at least 20 weight percent of an ester base oil. In one approach, the ester base oil of the base oil system is a linear or branched monoester, and in another approach, a linear or branched diester of a dicarboxylic acid. The diester or diesters can be the reaction product of one or more carboxylic acids having an internal carbon chain length of 6 to 10 carbons with one or more alcohols having branched carbon chain lengths of 6 to 12 carbons, and in another approach, 8 to 10 carbons, and in yet still other approaches, 8 to 12 carbons, and various mixtures thereof. The monoester base oil can have up to 20 carbons in the ester or alcohol group.

[0036] Suitable ester base oils may include those obtained from the reaction of select carboxylic or dicarboxylic acids, including sebacic acid, octanedioic acid, and / or adipic acid, and the like, and mixtures thereof, with various linear or branched alcohols, including 4-methylpentanol, 3-methylpentanol, 2-methylheptanol, hexan-2-ol, 6-methylheptanol, 5-methylheptanol, 4-methylheptanol, 3-methylpentanol, 2-methylheptanol, octan-2-ol, 2-ethylhexanol, 4-ethylhexanol, 8-methylnonanol, 7-methylnonanol, 6-methylnonanol, 5-methylnonanol, 4-methylnonanol, 3-methylnonanol, 2-methylnonanol, decan-2-ol, 11-methyldodecanol, and the like, and mixtures thereof. Specific examples of these diesters include bis(6-methylheptyl) hexanedioate, bis(8-methylnonyl) hexanedioate, bis(2-ethylhexyl) decanedioate, bis(2-ethylhexyl) hexanedioate, and the like, and combinations thereof. In one embodiment, the ester base oil is selected from diisooctyl adipate, diisodecyl adipate, eicosyl palmitate, or combinations thereof. In yet another embodiment, the ester base oil is a dibasic ester based on bis(6-methylheptyl) adipate, a dibasic ester based on bi(8-methylnonyl) adipate, or a linear monoester having about 16-18 carbons in the acid portion and about 20 carbons in the alcohol portion, or a combination thereof.

[0037] Such esters or diesters may be prepared by reacting a selected carboxylic acid or dicarboxylic acid with a selected alcohol (or mixtures thereof), as generally shown by the following exemplary reaction scheme 1, which results in a monoester or diester of formula (I): [ka] wherein R1 comprises m-2 carbons, and in some embodiments, m is an integer from 6 to 10; R2 and R3 are the same or different (in Formula I) and comprise a C6-C12 branched alkyl chain, and in other approaches a C8-C10 branched alkyl chain, and in yet other approaches a C8-C12 branched alkyl chain, and in yet other approaches a C6-C10 branched alkyl chain; and n is an integer of 0 or 1. (Specifically, Formula I is a monoester when n is 0 and a diester when n is 1.) Preferably, the integer n is 1, and R2 and R3 are the same or different and comprise a C8-C10 branched alkyl chain. In the context of a monoester, when n is 0, R3 and / or R2 can be up to 20 carbons, such as, for example, icosyl palmitate.

[0038] The diester base oil can have a mole percent of ester groups (—C(O)O—) of about 20 mole percent or more (e.g., about 20 to about 30 mole percent ester groups or about 20 to about 25 mole percent ester groups), and the monoester base oil can have a mole percent of ester groups of about 8 percent or less (e.g., about 6 to about 8 mole percent ester groups).

[0039] First Base Oil of the Base Oil System: The base oil system herein may also include one or more mineral oils and / or other synthetic oils as a first base oil component. As used herein, mineral oil and other synthetic oils refer to oils classified by the American Petroleum Institute (API) Category Groups I to V. Examples of natural oils include animal oils, vegetable oils (e.g., castor oil and lard oil), and mineral oils such as petroleum, paraffinic, or naphthenic oils. Oils derived from coal or shale are also suitable. The American Petroleum Institute classifies these different base stock types as follows: Group I, greater than 0.03 weight percent sulfur and / or less than 90 volume percent saturates, with a viscosity index of 80 to 120; Group II, 0.03 weight percent or less sulfur and 90 volume percent or more saturates, with a viscosity index of 80 to 120; Group III, 0.03 weight percent or less sulfur and 90 volume percent or more saturates, with a viscosity index of 120 or more; and Group IV, all polyalphaolefins. Hydrotreated and catalytically dewaxed base stocks generally fall into the Group II and Group III categories due to their low sulfur and aromatics content. Polyalphaolefins (Group IV base stocks) are synthetic base oils prepared from various alphaolefins and are substantially free of sulfur and aromatics. Many Group V base oils are also true synthetic products and may contain diesters, polyol esters, polyalkylene glycols, alkylated aromatics, polyphosphate esters, polyvinyl ethers, and / or polyphenyl ethers, etc.

[0040] Suitable oils can be derived from hydrocracked, hydrogenated, hydrofinished, unrefined, refined, and rerefined oils, and mixtures thereof. Any oil blends of other base oils can be used as long as they do not impair the desired lubrication, electrical, and thermal properties discussed above.

[0041] Unrefined oils are derived from natural, mineral, or synthetic sources with little or no further purification processing. Refined oils are similar to unrefined oils except that they have been processed by one or more purification steps, which may result in the improvement of one or more properties. Examples of suitable purification techniques are solvent extraction, secondary distillation, acid or base extraction, filtration, percolation, etc. Oils refined to edible oil quality may or may not be useful. Edible oils may also be called white oils. In some embodiments, the lubricant composition does not include edible oils or white oils.

[0042] Re-refined oils are also known as reclaimed or reprocessed oils. These oils are obtained by methods similar to those used to obtain refined oils, using the same or similar processes. Often, these oils are further processed by techniques directed to the removal of spent additives and oil breakdown products.

[0043] Mineral oils may include oils obtained by drilling or from plants and animals, and mixtures thereof. For example, such oils include, but are not limited to, castor oil, lard oil, olive oil, peanut oil, corn oil, soybean oil, and linseed oil, as well as mineral lubricating oils, such as liquid petroleum oils and solvent- or acid-treated mineral lubricating oils of the paraffinic, naphthenic, or mixed paraffinic-naphthenic types. Such oils may be partially or fully hydrogenated, if desired. Oils derived from coal or shale may also be useful.

[0044] Other useful synthetic lubricating oils may include hydrocarbon oils such as polymerized, oligomerized, or interpolymerized olefins (e.g., polybutylene, polypropylene, propylene-isobutylene copolymers); poly(1-hexene), poly(1-octene), trimers or oligomers of 1-decene, such as poly(1-decene) (such materials are often referred to as α-olefins), and mixtures thereof; alkyl-benzenes (e.g., dodecylbenzene, tetradecylbenzene, dinonylbenzene, di-(2-ethylhexyl)-benzene); polyphenyls (e.g., biphenyl, terphenyl, alkylated polyphenyls); diphenylalkanes, alkylated diphenylalkanes, alkylated diphenyl ethers, and alkylated diphenyl sulfides, and derivatives, analogs, and homologs thereof, or mixtures thereof.

[0045] Other synthetic lubricating oils include polyol esters, liquid esters of phosphorus-containing acids (e.g., tricresyl phosphate, trioctyl phosphate, and diethyl ester of decane phosphonic acid), or polymeric tetrahydrofurans. Synthetic oils may be produced by the Fischer-Tropsch reaction and typically may be hydroisomerized Fischer-Tropsch hydrocarbons or waxes. In embodiments, oils may be prepared by Fischer-Tropsch gas-to-liquid synthesis procedures and from other gas-to-liquid oils.

[0046] The first base oil component of the base oil system herein may have a KV100 (kinematic viscosity at 100° C.) of from about 2 to about 6 cSt, from about 2 to about 4 cSt, from about 2 to about 3 cSt, measured according to ASTM D445-18.

[0047] The base oil systems used in the lubricating and cooling fluids herein comprise a blend of a first base oil with the ester base oils described above, and in some embodiments, a blend of the ester base oil with one or more of Group I through Group V base oils. In other embodiments, the first base oil is one or more oils selected from Group I through Group IV base oils, and in yet other embodiments, the first base oil is a mineral base oil selected from Group I, Group II, and / or Group III, or alternatively, a polyalphaolefin base oil selected from Group IV.

[0048] In some approaches, for example, base oil systems herein suitable for magnet wire durability when combined with the mentioned detergent systems comprise at least about 20 weight percent ester base oil, and in other approaches from about 20 to about 80 weight percent ester base oil (based on the total weight of the base oil system), and in yet other approaches the base oil system is from about 30 to about 75 weight percent ester base oil, and in yet other approaches from about 35 to about 73 weight percent ester base oil. In other approaches or embodiments, the base oil system may comprise ester base oil in an amount ranging from at least about 20 weight percent, at least about 25 weight percent, at least about 30 weight percent, at least about 35 weight percent, at least about 40 weight percent, or at least about 50 weight percent to about 80 weight percent or less, about 70 weight percent or less, about 65 weight percent or less, or about 50 weight percent or less of the total base oil system.

[0049] In some approaches, for example, a base oil system suitable for the lubricating compositions herein comprises from about 20 to about 80 weight percent of a Group I, II, III, and / or IV oil as the first base oil (based on the total weight of the base oil system), and in still other approaches, the base oil system is from about 60 to about 90 weight percent of the first base oil. In other approaches or embodiments, the base oil system may comprise the first base oil in an amount ranging from at least about 50 weight percent, at least about 60 weight percent, at least about 70 weight percent, at least about 75 weight percent to up to about 80 weight percent, or up to about 75 weight percent.

[0050] The finished lubricating and cooling fluid may comprise a majority amount of the base oil system (being the first base oil and the ester base oil), in some approaches from about 70 to about 98 weight percent, in other approaches from about 75 to about 90 weight percent, and in yet other approaches from about 75 to about 85 weight percent of the base oil system. In other approaches or embodiments, the lubricating composition may comprise the base oil system in an amount ranging from at least about 70 weight percent, at least about 75 weight percent, at least about 80 weight percent, at least about 85 weight percent, or at least 90 weight percent to about 98 weight percent or less, about 90 weight percent or less, about 85 weight percent or less, or about 80 weight percent or less.

[0051] In some approaches or embodiments, the base oil system herein comprises a blend of Group I through Group V base oils as a first base oil, and the recited ester base oil may have a KV100 of from about 2 to about 20 cSt, from about 2 to about 10 cSt in other approaches, from about 2.5 to about 6 cSt, from about 2.5 to about 3.5 cSt in yet other approaches, and from about 2.5 to about 4.5 cSt in yet other approaches.

[0052] Lubricating and Cooling Fluids

[0053] The lubricating and cooling fluids of the present disclosure are suitable for lubricating the transmissions and other components of electric and / or hybrid electric vehicles and comprise the above-described base oil system combined with one or more detergent additives that provide a selected ratio of metal to mole percent of ester groups (i.e., —C(O)O— groups) in the base oil system. A suitable ratio of metal to mole percent of ester groups in the base oil system can be about 70 or less, and in other approaches about 10 to about 70, to achieve high breakdown voltages of magnet wire. The lubricating oil compositions can be driveline oils, automotive transmission fluids, engine oils, etc., and are particularly suitable for lubricating and contacting components of electric and / or hybrid electric vehicles, including motors, generators, motor stators, and / or batteries.

[0054] In yet another approach, the lubricating and cooling fluids may comprise from about 30 to about 75 weight percent of the ester base oil as described herein, based on the total weight of the lubricating and cooling fluid. In other approaches, the lubricating and cooling fluids may comprise an amount of the ester base oil ranging from at least about 30 weight percent, at least about 40 weight percent, at least about 50 weight percent, at least about 60 weight percent, at least about 65 weight percent, at least about 70 weight percent to less than about 80 weight percent, less than about 75 weight percent, less than about 70 weight percent, less than about 60 weight percent, less than about 50 weight percent, or less than about 40 weight percent.

[0055] In a further approach, the lubricating oil composition may also comprise from about 40 to about 80 wt. % of one or more mineral or other synthetic (PAO) oils as a first base oil, based on the total weight of the lubricating / cooling fluid. The first base oil may comprise at least one or more of the Group I through Group V oils discussed above, so long as the lubricating composition still achieves the desired properties as discussed throughout this disclosure.

[0056] As used herein, the terms "oil composition," "lubricating composition," "lubricating oil composition," "lubricating oil," "lubricant composition," "fully formulated lubricant composition," "lubricant," and "lubricating and cooling fluid" are considered synonymous and fully interchangeable terms that refer to a finished lubricating product that includes a majority amount of a base oil component and minor amounts of detergents and other optional ingredients.

[0057] The lubricants herein may also contain other optional additives as needed for a particular application, so long as such additives do not impair the electrical and cooling properties as discussed herein. Some common optional additives are described herein.

[0058] Optional Additive Ingredients

[0059] In addition to the base oils described above, the lubricating oil compositions herein may also contain other additives to perform one or more functions required of a lubricating fluid. Furthermore, one or more of the additives described above may be multifunctional and provide other functions in addition to or other than those described herein.

[0060] For example, the compositions herein may include one or more of at least one component selected from the group consisting of friction modifiers, air scavenging additives, antioxidants, corrosion inhibitors, foam inhibitors, seal swell agents, viscosity index improvers, rust inhibitors, extreme pressure additives, and combinations thereof. Other performance additives, in addition to those specified above, may also include one or more of metal deactivators, ashless TBN boosters, demulsifiers, emulsifiers, pour point depressants, and mixtures thereof. Typically, fully formulated lubricating oils will contain one or more of these performance additives. Examples of some common optional additive components are listed below.

[0061] Viscosity index improver

[0062] In addition to the poly(meth)acrylate copolymers described above, the lubricating oil compositions herein may optionally contain one or more additional or supplemental viscosity index improvers. Suitable supplemental viscosity index improvers may include polyolefins, olefin copolymers, ethylene / propylene copolymers, polyisobutene, hydrogenated styrene-isoprene polymers, styrene / maleic acid ester copolymers, hydrogenated styrene / butadiene copolymers, hydrogenated isoprene polymers, alpha-olefin maleic anhydride copolymers, poly(meth)acrylates, polyacrylates, polyalkylstyrenes, hydrogenated alkenylaryl conjugated diene copolymers, or mixtures thereof. The viscosity index improver may also include star polymers, suitable examples of which are described in U.S. Publication No. 2012 / 0101017(A1).

[0063] The lubricating oil compositions herein may optionally also contain one or more dispersant viscosity index improvers in addition to the PMA viscosity index improvers discussed above. Suitable dispersant viscosity index improvers may include functionalized polyolefins, such as ethylene-propylene copolymers functionalized with the reaction product of an acylating agent (such as maleic anhydride) and an amine, amine-functionalized poly(meth)acrylates, or esterified maleic anhydride-styrene copolymers reacted with amines.

[0064] The total amount of viscosity index improver and / or dispersant viscosity index improver can be from 0% to 20%, 0.1% to 15%, 0.25% to 12%, or 0.5% to 10% by weight of the lubricating composition.

[0065] Dispersants

[0066] Lubricant compositions may contain one or more select dispersants or mixtures thereof. Dispersants are often referred to as ashless-type dispersants because they do not contain ash-forming metals prior to incorporation into the lubricating oil composition and do not typically contribute ash when added to the lubricant. Ashless-type dispersants are characterized by a polar group attached to a relatively high molecular weight or weight hydrocarbon chain. Typical ashless dispersants include N-substituted long-chain alkenyl succinimides. N-substituted long-chain alkenyl succinimides contain polyisobutylene (PIB) substituents with a number average molecular weight of the polyisobutylene substituent ranging from about 800 to about 2500, as determined by gel permeation chromatography (GPC) using polystyrene (having a number average molecular weight of 180 to about 18,000) as the calibration standard. PIB substituents used in dispersants typically have a viscosity at 100°C of about 2100 to about 2700 cSt, as determined using ASTM D445-18. Succinimide dispersants and their preparation methods are disclosed, for example, in U.S. Patent Nos. 7,897,696 and 4,234,435, which are incorporated herein by reference. Succinimide dispersants are typically imides formed from polyamines, typically poly(ethyleneamines). The dispersant may contain two succinimide moieties connected by a polyamine. The polyamine may be tetraethylenepentamine (TEPA), triethylenetetraamine (TETA), pentaethylenehexaamine (PEHA), other high-nitrogen ethylenediamine species, and / or mixtures thereof. The polyamine may be a mixture of linear, branched, and cyclic amines. A PIB substituent may be attached to each succinimide moiety.

[0067] In some embodiments, the lubricant composition comprises at least one polyisobutylene succinimide dispersant derived from polyisobutylene having a number average molecular weight, as measured by the GPC method described above, in the range of from about 350 to about 5000, or from about 500 to about 3000. The polyisobutylene succinimide may be used alone or in combination with other dispersants.

[0068] In some embodiments, polyisobutylene (PIB), when present, may have a terminal double bond content of greater than 50 mol%, greater than 60 mol%, greater than 70 mol%, greater than 80 mol%, or greater than 90 mol%. Such PIB is also referred to as highly reactive PIB ("HR-PIB"). HR-PIB having a number average molecular weight in the range of about 800 to about 5000 is suitable for use in embodiments of the present disclosure. Conventional non-highly reactive 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%.

[0069] HR-PIB having a number average molecular weight ranging from about 900 to about 3000, as measured by the GPC method described above, may be suitable. Such HR-PIB is commercially available or can be synthesized by polymerization of isobutene in the presence of a non-chlorinated catalyst, such as boron trifluoride, as described in U.S. Pat. Nos. 4,152,499 and 5,739,355. When used in the aforementioned thermal ene reaction, HR-PIB can result in higher conversion rates and less precipitate formation in the reaction due to its increased reactivity.

[0070] In some embodiments, the lubricant composition includes at least one dispersant derived from polyisobutylene succinic anhydride. In embodiments, the dispersant may be derived from polyalphaolefin (PAO) succinic anhydride. In embodiments, the dispersant may be derived from an olefin maleic anhydride copolymer. By way of example, the dispersant may be described as polyPIBSA. In embodiments, the dispersant may be derived from an anhydride grafted to an ethylene-propylene copolymer.

[0071] One type of suitable dispersant can be a Mannich base. Mannich bases are materials formed by the condensation of higher molecular weight alkyl-substituted phenols, polyalkylene polyamines, and aldehydes such as formaldehyde. Mannich bases are described in more detail in U.S. Pat. No. 3,634,515.

[0072] A suitable type of dispersant may be a high molecular weight ester or half ester amide.

[0073] Suitable dispersants can also be post-treated by conventional methods by reaction with any of a variety of agents, including boron, urea, thiourea, dimercaptothiadiazole, carbon disulfide, aldehydes, ketones, carboxylic acids, hydrocarbon-substituted succinic anhydrides, maleic anhydride, nitriles, epoxides, carbonates, cyclic carbonates, hindered phenol esters, and phosphorus compounds. U.S. Patent Nos. 7,645,726, 7,214,649, and 8,048,831 describe some suitable post-treatment methods and post-treated products.

[0074] Suitable boron compounds useful in forming the dispersants herein include any boron compound or mixture of boron compounds capable of introducing a boron-containing species into the ashless dispersant. Any organic or inorganic boron compound capable of undergoing such a reaction can be used. Thus, boron oxide, boron oxide hydrate, boron trifluoride, boron tribromide, boron trichloride, HBF4, boric acids such as boronic acids (e.g., alkyl-B(OH)2 or aryl-B(OH)2), boric acid (i.e., H3BO3), tetraboric acid (i.e., H2BO7), metaboric acid (i.e., HBO2), ammonium salts of such boric acids, and esters of such boric acids can be used. The use of complexes of boron trihalides with ethers, organic acids, inorganic acids, or hydrocarbons is a convenient means of introducing the boron reactant into the reaction mixture. Such complexes are known and are exemplified by boron trifluoride-diethyl ether, boron trifluoride-phenol, boron trifluoride-phosphoric acid, boron trichloride-chloroacetic acid, boron tribromide-dioxane, and boron trifluoride-methyl ethyl ether.

[0075] Suitable phosphorus compounds for forming the dispersant herein include any phosphorus compound or mixture of phosphorus compounds capable of introducing phosphorus-containing species into the ashless dispersant. Thus, either organic or inorganic phosphorus compounds capable of such a reaction can be used. Thus, such inorganic phosphorus compounds can be used as inorganic phosphoric acid and inorganic phosphorus oxides, including hydrates thereof. Typical organophosphorus compounds include full and partial esters of phosphoric acid, such as the mono-, di-, and triesters of phosphoric, thiophosphoric, dithiophosphoric, trithiophosphoric, and tetrathiophosphoric acids; the mono-, di-, and triesters of phosphorous, thiophosphorous, dithiophosphorous, and trithiophosphorous acids; trihydrocarbyl phosphine oxides; trihydrocarbyl phosphine sulfides; mono- and dihydrocarbyl phosphonates (RPO(OR')(OR"), where R and R' are hydrocarbyl and R" is hydrogen or a hydrocarbyl group), and their mono-, di-, and trithio analogs; mono- and dihydrocarbyl phosphonites (RP(OR')(OR"), where R and R' are hydrocarbyl and R" is hydrogen or a hydrocarbyl group), and their mono- and dithio analogs. Thus, such compounds may be, for example, phosphorous acid (H3PO3, sometimes represented as H2(HPO3) and sometimes called ortho-phosphorous acid or phosphonic acid), phosphoric acid (H3PO4, sometimes called orthophosphoric acid), hypophosphoric acid (H4P2O6), metaphosphoric acid (HPO3), pyrophosphoric acid (H4P2O7), hypophosphorous acid (H3PO2, sometimes called phosphinic acid), pyrophosphorous acid (H4P2O5, sometimes called pyrophosphonic acid), phosphinous acid (H3PO), tripolyphosphoric acid (H5P3O 10 ), tetrapolyphosphate (H5P4O 13 ), trimetaphosphoric acid (H3P3O9), phosphorus trioxide, phosphorus tetroxide, phosphorus pentoxide, etc. Phosphorotetrathioic acid (H3PS4), phosphoromonothioic acid (H3PO3S), phosphorodithioic acid (H3PO2S2), phosphorotrithioic acid (H3POS3), phosphorus sesquisulfide, phosphorus heptasulfide, and phosphorus pentasulfide (PS5, P4S10 Partial or all sulfur analogs such as HCl, HCl (sometimes referred to as HCl), may also be used in forming dispersants for the present disclosure. Inorganic phosphorus halide compounds such as PCl, PBr, POCl, PSCl, etc. may also be used.

[0076] Similarly, such organophosphorus compounds may be used as mono-, di-, and triesters of phosphoric acid (e.g., trihydrocarbyl phosphates, dihydrocarbyl monoacid phosphates, monohydrocarbyl diacid phosphates, and mixtures thereof), mono-, di-, and triesters of phosphorous acid (e.g., trihydrocarbyl phosphites, dihydrocarbyl hydrogen phosphites, hydrocarbyl diacid phosphites, and mixtures thereof), esters of phosphonic acid (both "primary", R P(O)(OR) and "secondary", R P(O)(OR)), esters of phosphinic acid, phosphonyl halides (e.g., For example, RP(O)Cl and RP(O)Cl), halophosphites (e.g., (RO)PCl and (RO)PCl), halophosphates (e.g., ROP(O)Cl and (RO)P(O)Cl), tertiary pyrophosphates (e.g., (RO)P(O)-OP(O)(OR)), and all- or partial-sulfur analogs of any of the foregoing organophosphorus compounds can be used, where each hydrocarbyl group contains up to about 100 carbon atoms, or up to about 50 carbon atoms, or up to about 24 carbon atoms, or up to about 12 carbon atoms. Halophosphines (e.g., hydrocarbyl phosphorus tetrahalides, dihydrocarbyl phosphorus trihalides, and trihydrocarbyl phosphorus dihalides), and halophosphines (monohalophosphines and dihalophosphines) can also be used.

[0077] Lubricants herein may include mixtures of one or more of the borated and phosphated dispersants described above in combination with non-boronated and non-phosphated dispersants.

[0078] In one embodiment, the lubricating oil composition may contain at least one borated dispersant, where the dispersant is an olefin copolymer or a reaction product of an olefin copolymer or a reaction product of an olefin copolymer with succinic anhydride and at least one polyamine. The ratio of PIBSA to polyamine may be from 1:1 to 10:1, or from 1:1 to 5:1, or from 4:3 to 3:1, or from 4:3 to 2:1. Particularly useful dispersants comprise polyisobutenyl groups in PIBSA having a number average molecular weight (Mn) in the range of about 500 to 5000 as measured by the GPC method described above, and a polyamine having the general formula HN(CH). m -[NH(CH2) m ] n and (B) a polyamine having —NH 2 , wherein m is in the range of 2 to 4 and n is in the range of 1 to 2.

[0079] In addition to the above, the dispersant may be post-treated with an aromatic carboxylic acid, aromatic polycarboxylic acid, or aromatic anhydride, with all carboxylic acid or anhydride groups directly attached to the aromatic ring. Such carboxyl-containing aromatic compounds may be selected from 1,8-naphthalene acid or anhydride and 1,2-naphthalenedicarboxylic acid or anhydride, 2,3-naphthalenedicarboxylic acid or anhydride, naphthalene-1,4-dicarboxylic acid, naphthalene-2,6-dicarboxylic acid, phthalic anhydride, pyromellitic anhydride, 1,2,4-benzenetricarboxylic anhydride, diphenic acid or anhydride, 2,3-pyridinedicarboxylic acid or anhydride, 3,4-pyridinedicarboxylic acid or anhydride, 1,4,5,8-naphthalenetetracarboxylic acid or anhydride, perylene-3,4,9,10-tetracarboxylic anhydride, pyrenedicarboxylic acid or anhydride, and the like. The moles of this post-treatment component reacted per mole of polyamine may range from about 0.1:1 to about 2:1. Typical molar ratios of this post-treatment component to polyamine in the reaction mixture may range from about 0.2:1 to about 2:1. Alternative molar ratios of this post-treatment component to polyamine that may be used may range from 0.25:1 to about 1.5:1. This post-treatment component may be reacted with the other components at temperatures ranging from about 140°C to about 180°C.

[0080] Alternatively, or in addition to the above-mentioned post-treatment, the dispersant may be post-treated with a non-aromatic dicarboxylic acid or anhydride. The non-aromatic dicarboxylic acid or anhydride may have a number average molecular weight of less than 500 as measured by the GPC method described above. Suitable carboxylic acids or anhydrides may include, but are not limited to, acetic acid or anhydride, oxalic acid and anhydride, malonic acid and anhydride, succinic acid and anhydride, alkenylsuccinic acid and anhydride, glutaric acid and anhydride, adipic acid and anhydride, pimelic acid and anhydride, suberic acid and anhydride, azelaic acid and anhydride, sebacic acid and anhydride, maleic acid and anhydride, fumaric acid and anhydride, tartaric acid and anhydride, glycolic acid and anhydride, 1,2,3,6-tetrahydronaphthalic acid and anhydride, and the like.

[0081] The non-aromatic carboxylic acid or anhydride is reacted with the polyamine in a molar ratio ranging from about 0.1 to about 2.5 moles per mole of polyamine. Typically, the amount of non-aromatic carboxylic acid or anhydride used will be proportional to the number of secondary amino groups in the polyamine. Thus, about 0.2 to about 2.0 moles of non-aromatic carboxylic acid or anhydride per secondary amino group in component B can be reacted with the other components to provide a dispersant according to an embodiment of the present disclosure. Other molar ratios of non-aromatic carboxylic acid or anhydride to polyamine that can be used range from 0.25:1 to about 1.5:1 moles per mole of polyamine. The non-aromatic carboxylic acid or anhydride can be reacted with the other components at temperatures ranging from about 140°C to about 180°C.

[0082] The active matter weight percent of the alkenyl or alkyl succinic anhydride can be measured using chromatographic techniques, as described in claims 5 and 6 of U.S. Patent No. 5,334,321. The polyolefin conversion is calculated from the activity percent using the formula described in columns 5 and 6 of U.S. Patent No. 5,334,321.

[0083] Suitable borated dispersants may have a TBN of from about 10 to about 65 mg KOH / gram without oil, which is equivalent to a TBN of from about 5 to about 30 mg KOH / gram when measured on a dispersant sample containing about 50% diluent oil.

[0084] Typically, the dispersants described above are provided in the lubricant at about 4.5 to about 25 weight percent, and in other approaches, about 4.5 to about 12 weight percent, and in still other approaches, about 4.5 to about 7.7 weight percent.

[0085] extreme pressure agents

[0086] The lubricating oil compositions herein may also 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, dibutyl tetrasulfide, sulfurized methyl ester of oleic acid, sulfurized alkylphenols, sulfurized dipentene, sulfurized terpene, and sulfurized Diels-Alder adducts; phosphorus sulfurized hydrocarbons, such as the reaction product of phosphorus sulfide with turpentine or methyl oleate; phosphites, such as dihydrocarbyl phosphites and trihydrocarbyl phosphites; For example, dibutyl phosphite, diheptyl phosphite, dicyclohexyl phosphite, pentylphenyl phosphite; dipentylphenyl phosphite, tridecyl phosphite, distearyl phosphite, and polypropylene-substituted phenyl phosphites; metal thiocarbamates, such as zinc dioctyldithiocarbamate and barium heptylphenol diate; amine salts of alkyl and dialkyl phosphoric acids, including, for example, the amine salt of the reaction product of a dialkyldithiophosphoric acid with propylene oxide; and mixtures thereof.

[0087] The extreme pressure agent may be present in an amount of, for example, 0 to 3.0 wt %, or 0.1 to 2.0 wt %, based on the total weight of the lubricating oil composition.

[0088] Antioxidants: The lubricating oil compositions herein may also optionally contain one or more antioxidants. Examples of suitable antiwear agents include, but are not limited to, metal thiophosphates, metal dialkyldithiophosphates; phosphate esters or salts thereof; phosphoric acid esters; phosphites; phosphorus-containing carboxylic acid esters, ethers, or amides; sulfurized olefins; thiocarbamate-containing compounds such as thiocarbamate esters, alkylene-linked thiocarbamates, and bis(S-alkyldithiocarbamyl) disulfides; and mixtures thereof. A suitable antiwear agent may be molybdenum dithiocarbamate. Phosphorus-containing antiwear agents are described in more detail in EP 612839. The metal in the dialkyldithiophosphate salt may be an alkali metal, alkaline earth metal, aluminum, lead, tin, molybdenum, manganese, nickel, copper, titanium, or zinc. A useful antiwear agent may be zinc dialkyldithiophosphate.

[0089] Further examples of suitable antiwear agents include titanium compounds, tartrates, tartrimides, oil-soluble amine salts of phosphorus compounds, sulfurized olefins, phosphites (e.g., dibutyl phosphite), phosphonates, thiocarbamate-containing compounds such as thiocarbamate esters, thiocarbamate amides, thiocarbamic acid ethers, alkylene-linked thiocarbamates, and bis(S-alkyldithiocarbamyl) disulfides. The tartrates or tartrimides may contain alkyl-ester groups, and the total number of carbon atoms on the alkyl group may be at least 8. The antiwear agent, in one embodiment, may include citrate.

[0090] The antiwear agent may be present in a range including from about 0% to about 15% by weight of the lubricating oil composition, in another approach from about 0.01% to about 10% by weight, in yet another approach from about 0.05% to about 5% by weight, or in a further approach from about 0.1% to about 3% by weight.

[0091] friction modifiers

[0092] The lubricating oil compositions herein may also 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 ether amines, amine oxides, amidoamines, nitriles, betaines, quaternary amines, imines, amine salts, aminoguanidines, alkanolamides, phosphonic acids, metal-containing compounds, glycerol esters, sulfurized fatty compounds and olefins, sunflower oil and 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.

[0093] Suitable friction modifiers may contain hydrocarbyl groups selected from linear, branched, or aromatic hydrocarbyl groups, or mixtures thereof, and may be saturated or unsaturated. The hydrocarbyl groups may be composed of carbon and hydrogen or heteroatoms such as sulfur or oxygen. The hydrocarbyl groups may range from 12 to 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, a diester, or a (tri)glyceride. The friction modifier may be a long-chain fatty amide, a long-chain fatty ester, a long-chain fatty epoxide derivative, or a long-chain imidazoline.

[0094] Other suitable friction modifiers may include organic, ashless (metal-free), nitrogen-free friction modifiers. Such friction modifiers include esters formed by reacting carboxylic acids and anhydrides with alkanols, and may generally contain polar end groups (e.g., carboxyl or hydroxyl) covalently bonded to an oleophilic 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 U.S. Patent No. 6,723,685.

[0095] Aminic friction modifiers may include amines or polyamines. Such compounds may have hydrocarbyl groups that are either saturated or unsaturated, linear, or a mixture thereof, and may contain 12 to 25 carbon atoms. Further examples of suitable friction modifiers include alkoxylated amines and alkoxylated ether amines. Such compounds may have hydrocarbyl groups that are linear, saturated, unsaturated, or a mixture thereof. They may contain from about 12 to about 25 carbon atoms. Examples include ethoxylated amines and ethoxylated ether amines.

[0096] The amines and amides may be used as such or in the form of 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. Pat. No. 6,300,291.

[0097] Friction modifiers may optionally be present in ranges such as 0% to 6% by weight, or 0.01% to 4% by weight, or 0.05% to 2% by weight. Detergent

[0098] The lubricant composition also contains one or more selected detergents or mixtures thereof to provide a specific amount of metal and soap content to the lubricating composition. By one approach, the detergent is a metal-containing detergent, such as a neutral to overbased detergent. Suitable detergent substrates include phenates, sulfur-containing phenates, sulfonates, calixarates, salixarates, salicylates, carboxylic acids, phosphoric acids, mono- and / or di-thiophosphoric acids, alkylphenols, sulfur-bonded alkylphenol compounds, and methylene-bridged phenols. Suitable detergents and their preparation are described in more detail in numerous patent publications, including U.S. Pat. No. 7,732,390 and the references cited therein. By one approach, the detergent is a neutral to overbased sulfonate, phenate, or carboxylate containing an alkali metal or alkaline earth metal salt. The detergent can be linear or branched, such as a linear or branched sulfonate. Linear detergents are those containing a straight chain with no side chains attached, typically containing a carbon atom bonded to only one or two other carbon atoms. Branched detergents are those containing one or more side chains attached to the backbone of the molecule, and may contain a carbon atom bonded to one, two, three, or four other carbon atoms. In one embodiment, the sulfonate detergent may be a predominantly linear alkylbenzene sulfonate detergent. In some embodiments, the linear alkyl (or hydrocarbyl) group may be attached to the benzene ring anywhere along the linear chain of the alkyl group, but is often attached to the 2-, 3-, or 4-position of the linear chain, and in some instances, is predominantly attached to the 2-position. In other embodiments, the alkyl (or hydrocarbyl) group may be branched, i.e., formed from a branched olefin such as propylene or 1-butene or isobutene. Sulfonate detergents having a mixture of linear and branched alkyl groups may also be used.

[0099] The detergent substrate may be salted with an alkali or alkaline earth metal, such as, but not limited to, calcium, magnesium, potassium, sodium, lithium, barium, or mixtures thereof. In some embodiments, the detergent is barium-free. Suitable detergents may include alkali or alkaline earth metal salts of petroleum sulfonic acids and long-chain mono- or di-alkylaryl sulfonic acids, where the aryl group is one of benzyl, tolyl, and xylyl.

[0100] Overbased detergent additives are known in the art and may be alkali or alkaline earth metal overbased 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, an aliphatic-substituted carboxylic acid, or an aliphatic-substituted phenol. The term "overbased" generally refers to metal salts, such as metal salts of sulfonates, carboxylates, and phenates, in which the amount of metal present exceeds the stoichiometric amount. Such salts may have conversion levels greater than 100% (i.e., they may contain more than 100% of the theoretical amount of metal required to convert the acid to its "standard" or "neutral" salt). The expression "metal ratio," often abbreviated as MR, is used to indicate the ratio of the total chemical equivalents of metal in the overbased salt to the chemical equivalents of metal in the neutral salt, according to known chemical reactivity and stoichiometry. In normal or neutral salts, the metal ratio is 1; in overbased salts, the MR is greater than 1. Such salts are commonly referred to as overbased, overbased, or superbased salts and may be salts of organic sulfur acids, carboxylic acids, or phenols. The detergents may also exhibit a total base number (TBN) of from about 27 to about 400, or alternatively from about 200 to about 400.

[0101] In transmission fluids, the detergent contributes less than about 455 ppm of metal to the lubricant composition. Higher levels of metal result in failure of one or more of the friction durability or wear tests described herein. In another approach, the detergent contributes from about 0 to about 281 ppm of metal. In yet another approach, the detergent contributes from about 0 to about 100 ppm of metal to the lubricant composition.

[0102] The detergent also provides a selected level of soap content to the lubricant composition, with the amount of soap provided being balanced with the level of metals, so that if the metals are not within the desired range, increasing the soap content will not achieve the desired results, as discussed in more detail in the Examples herein. By one approach, the detergent provides from about 0.02 to about 0.15 percent soap content to the final lubricating composition, such as sulfonate soaps, phenate soaps, and / or carboxylate soaps. In another approach, the detergent provides from about 0.02 to about 0.1 percent soap, and in yet another approach, from about 0.02 to about 0.05 percent soap.

[0103] Soap content generally refers to the amount of neutral organic acid salts and reflects the cleaning ability, or cleaning power, and soil lifting ability of a detergent. Soap content is shown for an exemplary calcium sulfonate detergent (represented as RSO3), with v, w, x, and y representing the number of sulfonate groups, calcium atoms, carbonate groups, and hydroxyl groups, respectively. v Ca w (CO3) x (Oh) y can be determined using the following formula:

number

[0104] In some approaches, the metal-containing detergent is not boronated so that the boron in the lubricant is provided solely by the dispersant.

[0105] The total amount of detergent that may be present in the lubricating oil composition may be from 0% to 2% by weight, or from about 0% to about 0.5% by weight, or from about 0% to about 0.15% by weight.

[0106] antioxidants

[0107] The lubricating oil compositions herein may also optionally contain one or more antioxidants. Antioxidant compounds are known and include, for example, phenates, phenate sulfides, sulfurized olefins, phosphosulfurized terpenes, sulfurized esters, aromatic amines, alkylated diphenylamines (e.g., nonyldiphenylamine, di-nonyldiphenylamine, octyldiphenylamine, di-octyldiphenylamine), phenyl-alpha-naphthylamines, alkylated phenyl-alpha-naphthylamines, hindered non-aromatic amines, phenols, hindered phenols, oil-soluble molybdenum compounds, polymeric antioxidants, or mixtures thereof. The antioxidant compounds may be used alone or in combination.

[0108] Useful antioxidants may include diarylamines and high molecular weight phenols. In embodiments, the lubricating oil composition may contain a mixture of diarylamines and high molecular weight phenols, such that each antioxidant may be present in an amount sufficient to provide up to about 5 wt. % antioxidant, based on the final weight of the lubricating oil composition. In embodiments, the antioxidant may be a mixture of 0.3 to 2 wt. % diarylamines and 0.4 to 2 wt. % high molecular weight phenols, based on the final weight of the lubricating oil composition.

[0109] The one or more antioxidants may be present in the range of 0% to 5%, or 0.01% to 5%, or 0.1% to 3%, or 0.8% to 2% by weight of the lubricating composition.

[0110] Corrosion inhibitors

[0111] The automatic transmission lubricant may further include additional corrosion inhibitors (it should be noted that some of the other mentioned ingredients may also have copper corrosion inhibitor properties). Suitable additional inhibitors of copper corrosion include ether amines, polyethoxylated compounds such as ethoxylated amines and ethoxylated alcohols, imidazolines, mono- and di-alkyl thiadiazoles, and the like.

[0112] Thiazoles, triazoles, and thiadiazoles can also be used in lubricants. Examples include benzotriazole, tolyltriazole, octyltriazole, decyltriazole, dodecyltriazole, 2-mercaptobenzothiazole, 2,5-dimercapto-1,3,4-thiadiazole, 2-mercapto-5-hydrocarbylthio-1,3,4-thiadiazole, and 2-mercapto-5-hydrocarbyldithio-1,3,4-thiadiazole. In one embodiment, the thiadiazole is 1,3,4-thiadiazole. In another embodiment, the thiadiazole is 2-hydrocarbyldithio-5-mercapto-1,3,4-dithiadiazole. Many thiadiazoles are commercially available.

[0113] When present, the corrosion inhibitor may be used in an amount sufficient to provide from 0 wt. % to 5 wt. %, from 0.01 wt. % to 3 wt. %, from 0.1 wt. % to 2 wt. %, based on the final weight of the lubricating oil composition.

[0114] Antifoam / defoaming agents

[0115] Antifoaming agents / surfactants may also be included in the fluids of the present disclosure. Various agents are known for such applications. In one embodiment, the agent is a copolymer of ethyl acrylate and hexyl ethyl acrylate, such as PC-1244, available from Solutia. In another embodiment, the agent is a silicone fluid, such as 4% DCF. In another embodiment, the agent is a mixture of antifoaming agents.

[0116] Rust inhibitor

[0117] A variety of known rust inhibitors or additives are known for use in transmission fluids and are suitable for use in fluids according to the present disclosure, including alkyl polyoxyalkylene ethers such as Mazawet® 77, C-8 acids such as Neofat® 8, oxyalkylamines such as Tomah PA-14, 3-decyloxypropylamine, and polyoxypropylene-polyoxyethylene block copolymers such as Pluronic® L-81.

[0118] Pour Point Depressants

[0119] Suitable pour point depressants may include polymethyl methacrylate or mixtures thereof. The pour point depressant may be present in an amount sufficient to provide from 0 to 1 wt %, from 0.01 to 0.5 wt %, or from 0.02 to 0.04 wt %, based on the total weight of the lubricating composition.

[0120] Seal swelling agent

[0121] The automatic transmission fluids of the present disclosure may further include a seal swelling agent, such as an ester, adipate, sebacate, azelaate, phthalate, sulfone, alcohol, alkyl benzene, substituted sulfolane, aromatic compound, or mineral oil, that causes swelling of elastomeric materials used as seals in engines and automatic transmissions.

[0122] Alcohol-based seal swelling agents are generally low-volatility linear alkyl alcohols such as decyl alcohol, tridecyl alcohol, and tetradecyl alcohol. Alkyl benzenes useful as seal swelling agents include dodecyl benzene, tetradecyl benzene, dinonyl-benzene, di(2-ethylhexyl)benzene, and the like. Substituted sulfolanes (such as those described in U.S. Pat. No. 4,029,588, incorporated herein by reference) are also useful as seal swelling agents in compositions according to the present disclosure. Mineral oils useful as seal swelling agents in the present disclosure include low-viscosity mineral oils with high naphthenic or aromatic content. Aromatic seal swelling agents include the commercially available Exxon Aromatic 200 ND seal swelling agent. Commercially available examples of mineral oil seal swelling agents include Exxon® Necton®-37 (FN 1380) and Exxon® Mineral Seal Oil (FN 3200).

[0123] Based on the above discussion, exemplary ranges for various lubricating composition components are set forth in Table 1 below.

[0124] [Table 1]

[0125] The percentages of each component above represent the weight percent of each component, based on the total final weight of the lubricating oil composition. As defined above, 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 into the base oil individually or in various subcombinations. However, it may be preferred to blend all of the components simultaneously using an additive concentrate (i.e., additives plus a diluent such as a hydrocarbon solvent). definition

[0126] For purposes of this disclosure, chemical elements are identified according to the Periodic Table of the Elements, CAS version, Handbook of Chemistry and Physics, 75th Ed. Additionally, general principles of organic chemistry are described in "Organic Chemistry," Thomas Sorrell, University Science Books, Sausolito: 1999, and "March's Advanced Organic Chemistry," 5th Ed., Ed.: Smith, M.B. and March, J., John Wiley & Sons, New York: 2001, the entire contents of which are incorporated herein by reference.

[0127] As described herein, compounds may be optionally substituted with one or more substituents as exemplified generally above or by specific classes, subclasses, and species of the present disclosure.

[0128] Unless otherwise clear from the context, the term "major amount" is understood to mean an amount of 50 weight percent or more, for example, about 80 to about 98 weight percent, based on the total weight of the composition, and the term "minor amount" as used herein is understood to mean an amount of less than 50 weight percent, based on the total weight of the composition.

[0129] As used herein, the term "hydrocarbyl group" or "hydrocarbyl" is used in its ordinary sense, as is well known to those skilled in the art. Specifically, it refers to a group having a carbon atom directly attached to the remainder of the molecule and having predominantly hydrocarbon character. Examples of hydrocarbyl groups include (1) hydrocarbon substituents, i.e., aliphatic (e.g., alkyl or alkenyl) substituents, alicyclic (e.g., cycloalkyl, cycloalkenyl) substituents, and aromatic, aliphatic, and alicyclic-substituted aromatic substituents, as well as cyclic substituents in which the ring is completed through another portion of the molecule (e.g., two substituents together form an alicyclic radical); (2) substituted hydrocarbon substituents, i.e., substituents containing non-hydrocarbon groups (e.g., halo (especially chloro and fluoro), hydroxy, alkoxy, mercapto, alkylmercapto, nitro, nitroso, amino, alkylamino, and sulfoxy) that do not alter the predominantly hydrocarbon substituent in the context of this disclosure; and (3) heterosubstituents, i.e., substituents that, while predominantly hydrocarbon in the context of this disclosure, contain other than carbon atoms in the ring or chain or are otherwise composed of carbon atoms. Heteroatoms include sulfur, oxygen, and nitrogen, and encompass substituents such as pyridyl, furyl, thienyl, and imidazolyl. Generally, no more than two, or as a further example, only one, non-hydrocarbon substituent will be present for every ten carbon atoms in the hydrocarbyl group, and in some embodiments, there will be no non-hydrocarbon substituents in the hydrocarbyl group.

[0130] As used herein, the term "aliphatic" encompasses the terms alkyl, alkenyl, alkynyl, each of which is optionally substituted as described below.

[0131] As used herein, an "alkyl" group refers to a saturated aliphatic hydrocarbon group containing 1 to 12 (e.g., 1 to 8, 1 to 6, or 1 to 4) carbon atoms. The alkyl group can be straight-chained or branched. Examples of alkyl groups include, but are not limited to, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-heptyl, or 2-ethylhexyl. An alkyl group can have one or more substituents, such as halo, phospho, alicyclic [e.g., cycloalkyl or cycloalkenyl], heteroalicyclic [e.g., heterocycloalkyl or heterocycloalkenyl], aryl, heteroaryl, alkoxy, aroyl, heteroaroyl, acyl [e.g., (aliphatic)carbonyl, (alicyclic)carbonyl, or (heteroalicyclic)carbonyl], nitro, cyano, amido [e.g., (cycloalkylalkyl)carbonylamino, arylcarbonylamino, aralkylcarbonylamino, (heterocycloalkyl)carbonylamino, (heterocycloalkylalkyl)carbonylamino, heteroarylcarbonylamino, heteroaralkylcarbonylamino], or the like. It can be substituted (i.e., optionally substituted) with alkylaminocarbonyl, cycloalkylaminocarbonyl, heterocycloalkylaminocarbonyl, arylaminocarbonyl, or heteroarylaminocarbonyl], amino, [e.g., aliphatic amino, alicyclic amino, or heteroalicyclic amino], sulfonyl [e.g., aliphatic -SO2-], sulfinyl, sulfanyl, sulfoxy, urea, thiourea, sulfamoyl, sulfamido, oxo, carboxy, carbamoyl, alicyclicoxy, heterocycloaliphaticoxy, aryloxy, heteroaryloxy, aralkyloxy, heteroarylalkoxy, alkoxycarbonyl, alkylcarbonyloxy, or hydroxy.Some examples of substituted alkyls include, but are not limited to, carboxyalkyl (e.g., HOOC-alkyl, alkoxycarbonylalkyl, and alkylcarbonyloxyalkyl), cyanoalkyl, hydroxyalkyl, alkoxyalkyl, acylalkyl, aralkyl, (alkoxyaryl)alkyl, (sulfonylamino)alkyl (e.g., (alkyl-SO2-amino)alkyl), aminoalkyl, amidoalkyl, (alicyclic)alkyl, or haloalkyl.

[0132] As used herein, an "alkenyl" group refers to an aliphatic carbon group containing 2 to 8 (e.g., 2 to 12, 2 to 6, or 2 to 4) carbon atoms and at least one double bond. Like an alkyl group, an alkenyl group can be straight or branched. Examples of alkenyl groups include, but are not limited to, allyl, isoprenyl, 2-butenyl, and 2-hexenyl. Alkenyl groups can have one or more substituents, such as halo, phospho, alicyclic [e.g., cycloalkyl or cycloalkenyl], heteroalicyclic [e.g., heterocycloalkyl or heterocycloalkenyl], aryl, heteroaryl, alkoxy, aroyl, heteroaroyl, acyl [e.g., (aliphatic)carbonyl, (alicyclic)carbonyl, or (heteroalicyclic)carbonyl], nitro, cyano, amido [e.g., (cycloalkylalkyl)carbonylamino, arylcarbonylamino, aralkylcarbonylamino, (heterocycloalkyl)carbonylamino, (heterocycloalkylalkyl)carbonylamino, heteroarylcarbonylamino, heteroaralkylcarbonylamino, or heteroarylcarbonylamino. The aryloxy group may be optionally substituted with alkyl, cycloalkylaminocarbonyl, heterocycloalkylaminocarbonyl, arylaminocarbonyl, or heteroarylaminocarbonyl], amino, [e.g., aliphatic amino, cycloaliphatic amino, heteroalicyclic amino, or aliphatic sulfonylamino], sulfonyl [e.g., alkyl-SO2-, cycloaliphatic-SO2-, or aryl-SO2-], sulfinyl, sulfanyl, sulfoxy, urea, thiourea, sulfamoyl, sulfamido, oxo, carboxy, carbamoyl, cycloaliphaticoxy, heteroalicyclicoxy, aryloxy, heteroaryloxy, aralkyloxy, heteroaralkoxy, alkoxycarbonyl, alkylcarbonyloxy, or hydroxy. Some examples of substituted alkenyls include, but are not limited to, cyanoalkenyl, alkoxyalkenyl, acylalkenyl, hydroxyalkenyl, aralkenyl, (alkoxyaryl)alkenyl, (sulfonylamino)alkenyl (e.g., (alkyl-SO2-amino)alkenyl), aminoalkenyl, amidoalkenyl, (alicyclic)alkenyl, or haloalkenyl.

[0133] As used herein, an "alkynyl" group refers to an aliphatic carbon group containing 2 to 8 (e.g., 2 to 12, 2 to 6, or 2 to 4) carbon atoms and having at least one triple bond. Alkynyl groups can be straight-chained or branched. Examples of alkynyl groups include, but are not limited to, propargyl and butynyl. Alkynyl groups can be substituted with one or more groups, such as aroyl, heteroaroyl, alkoxy, cycloalkyloxy, heterocycloalkyloxy, aryloxy, heteroaryloxy, aralkyloxy, nitro, carboxy, cyano, halo, hydroxy, sulfo, mercapto, sulfanyl [e.g., aliphatic sulfanyl or alicyclic sulfanyl], sulfinyl [e.g., aliphatic sulfinyl or alicyclic sulfinyl], sulfonyl [e.g., aliphatic -SO2-, aliphatic amino-SO2-, or alicyclic -SO2-], amido [e.g., aminocarbonyl, alkylaminocarbonyl, alkylcarbonylamino, cycloalkylaminocarbonyl, heterocycloalkylaminocarbonyl, cycloalkylcarbonylamino, aryl aminocarbonyl, arylcarbonylamino, aralkylcarbonylamino, (heterocycloalkyl)carbonylamino, (cycloalkylalkyl)carbonylamino, heteroaralkylcarbonylamino, heteroarylcarbonylamino, or heteroarylaminocarbonyl], urea, thiourea, sulfamoyl, sulfamido, alkoxycarbonyl, alkylcarbonyloxy, alicyclic, heteroalicyclic, aryl, heteroaryl, acyl [e.g., (alicyclic)carbonyl or (heteroalicyclic)carbonyl], amino [e.g., aliphatic amino], sulfoxy, oxo, carboxy, carbamoyl, (alicyclic)oxy, (heteroalicyclic)oxy, or (heteroaryl)alkoxy.

[0134] As used herein, an "amino" group refers to an -NR X R Y In the formula, R X and R Yis independently hydrogen, alkyl, cycloalkyl, (cycloalkyl)alkyl, aryl, aralkyl, heterocycloalkyl, (heterocycloalkyl)alkyl, heteroaryl, carboxy, sulfanyl, sulfinyl, sulfonyl, (alkyl)carbonyl, (cycloalkyl)carbonyl, ((cycloalkyl)alkyl)carbonyl, arylcarbonyl, (aralkyl)carbonyl, (heterocycloalkyl)carbonyl, ((heterocycloalkyl)alkyl)carbonyl, (heteroaryl)carbonyl, or (heteroaralkyl)carbonyl, each of which is defined herein and optionally substituted. Examples of amino groups include alkylamino, dialkylamino, or arylamino. When the term "amino" is not a terminal group (e.g., alkylcarbonylamino), it is not -NR X - Represented by R X is as defined above.

[0135] As used herein, a "cycloalkyl" group refers to a saturated carbocyclic monocyclic or bicyclic (fused or bridged) ring of 3 to 10 (e.g., 5 to 10) carbon atoms. Examples of cycloalkyl groups include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, adamantyl, norbornyl, cubyl, octahydroindenyl, decahydronaphthyl, bicyclo[3.2.1]octyl, bicyclo[2.2.2]octyl, bicyclo[3.3.1]nonyl, bicyclo[3.3.2]decyl, bicyclo[2.2.2]octyl, adamantyl, or ((aminocarbonyl)cycloalkyl)cycloalkyl.

[0136] As used herein, a "heterocycloalkyl" group refers to a 3- to 10-membered mono- or bicyclic (fused or bridged) (e.g., 5- to 10-membered mono- or bicyclic) saturated ring structure in which one or more of the ring atoms is a heteroatom (e.g., N, O, S, or combinations thereof). Examples of heterocycloalkyl groups include piperidyl, piperazyl, tetrahydropyranyl, tetrahydrofuryl, 1,4-dioxolanyl, 1,4-dithianyl, 1,3-dioxolanyl, oxazolidyl, isoxazolidyl, morpholinyl, thiomorpholyl, octahydrobenzofuryl, octahydrochromenyl, octahydrothiochromenyl, octahydroindolyl, octahydropyrindinyl, decahydroquinolinyl, octahydrobenzo[b]thiophenyl, 2-oxa-bicyclo[2.2.2]octyl, 1-aza-bicyclo[2.2.2]octyl, 3-aza-bicyclo[3.2.1]octyl, and 2,6-dioxa-tricyclo[3.3.1.0]nonyl. Monocyclic heterocycloalkyl groups can be fused with a phenyl moiety to form structures such as tetrahydroisoquinoline, which would be classified as heteroaryls.

[0137] As used herein, a "heteroaryl" group refers to a monocyclic, bicyclic, or tricyclic ring system having 4 to 15 ring atoms, where one or more ring atoms are heteroatoms (e.g., N, O, S, or a combination thereof), and the monocyclic ring system is aromatic, or at least one ring in the bicyclic or tricyclic ring system is aromatic. Heteroaryl groups include benzo-fused ring systems having 2 to 3 rings. For example, a benzo-fused group includes benzo fused to one or two 4- to 8-membered heterocyclic aliphatic moieties (e.g., indolyl, indolyl, isoindolyl, 3H-indolyl, indolinyl, benzo[b]furyl, benzo[b]thiophenyl, quinolinyl, or isoquinolinyl). Some examples of heteroaryl are pyridyl, 1H-indazolyl, furyl, pyrrolyl, thienyl, thiazolyl, oxazolyl, imidazolyl, tetrazolyl, benzofuryl, isoquinolinyl, benzthiazolyl, xanthene, thioxanthene, phenothiazine, dihydroindole, benzo[1,3]dioxole, benzo[b]furyl, benzo[b]thiophenyl, indazolyl, benzimidazolyl, benzthiazolyl, puryl, cinnolyl, quinolyl, quinazolyl, cinnolyl, phthalazyl, quinazolyl, quinoxalyl, isoquinolyl, 4H-quinolidyl, benzo-1,2,5-thiadiazole, or 1,8-naphthyridyl.

[0138] Monocyclic heteroaryls include, but are not limited to, furyl, thiophenyl, 2H-pyrrolyl, pyrrolyl, oxazolyl, thazolyl, imidazolyl, pyrazolyl, isoxazolyl, isothiazolyl, 1,3,4-thiadiazolyl, 2H-pyranyl, 4H-pyranyl, pyridyl, pyridazyl, pyrimidyl, pyrazolyl, pyrazyl, or 1,3,5-triazyl. Monocyclic heteroaryls are numbered according to standard chemical nomenclature.

[0139] Bicyclic heteroaryls include indolizyl, indolyl, isoindolyl, 3H-indolyl, indolinyl, benzo[b]furyl, benzo[b]thiophenyl, quinolinyl, isoquinolinyl, indolizinyl, isoindolyl, indolyl, benzo[b]furyl, bexo[b]thiophenyl, indazolyl, benzimidazyl, benzthiazolyl, purinyl, 4H-quinolizyl, quinolyl, isoquinolyl, cinnolyl, phthalazyl, quinazolyl, quinoxalyl, 1,8-naphthyridyl, or pteridyl. Bicyclic heteroaryls are numbered according to standard chemical nomenclature.

[0140] As used herein, the term "treat rate" refers to the weight percent of a component in lubricating and cooling fluids. For example, the treat rate of a particular polymer or additive in an oil composition is the weight percent of the polymer or additive in the composition: Treat Rate = (weight of polymer / additive on an oil-free basis) / (weight of total composition) x 100%. As noted above, the polymer / additive treat rate herein refers to the solids of the polymer / additive without any oil or carrier fluid present.

[0141] As used herein, the term "viscosity index" is any measure of the change in viscosity with temperature. Viscosity index can be calculated using the following formula: VI = 100 * [(LU) / (LH)], where ● L = kinematic viscosity at 40°C of an oil with a viscosity index of 0 that has the same kinematic viscosity at 100°C as the oil for which the viscosity index is to be calculated, mm 2 / second (cSt), ● H = kinematic viscosity at 40°C of an oil with a viscosity index of 100 that has the same kinematic viscosity at 100°C as the oil for which the viscosity index is to be calculated, mm 2 / second (cSt), and ● U = kinematic viscosity at 40°C of the oil for which the viscosity index is to be calculated, mm 2 / second (cSt).

[0142] The weight-average molecular weight (Mw) and number-average molecular weight (Mn) can be determined using a gel permeation chromatography (GPC) instrument from Waters or similar equipment and 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). GPC operating conditions may include a guard column, four Agilent PLgel columns (300 x 7.5 mm long, 5 μm particle size, and pore sizes ranging from 100 to 10,000 Å), and a column temperature of approximately 40°C. Unstabilized HPLC-grade tetrahydrofuran (THF) can be used as the solvent at a flow rate of 1.0 mL / min. The GPC instrument can be calibrated using commercially available poly(methyl methacrylate) (PMMA) standards with narrow molecular weight distributions ranging from 960 to 1,568,000 g / mol. Calibration curves for samples with masses less than 500 g / mol may be extrapolated. Samples and PMMA standards can be prepared in THF at concentrations of 0.1 to 0.5% by weight and used without filtration. GPC measurements are also described in U.S. Pat. No. 5,266,223, which is incorporated herein by reference. The GPC method also provides molecular weight distribution information. See, for example, W.W. Yau, J.J. Kirkland, and D.D. Bly, "Modern Size Exclusion Liquid Chromatography," John Wiley and Sons, New York, 1979, also incorporated herein by reference.

[0143] As discussed, the lubricating and cooling fluids herein are particularly suitable for electric and hybrid electric vehicles. Electric vehicles are those equipped with batteries, including, but not limited to, lead-acid batteries, nickel-metal hydride batteries, lithium-ion batteries, and fuel cells, and an electric motor. Hybrid electric vehicles employ a combination of a battery, an electric motor, and an internal combustion engine. The lubricants herein may be in contact with components of the electric motor, the magnet wire within the electric motor, and / or may be used both for the transmission and for cooling and lubricating the motor. For example, the lubricating compositions herein may be in contact with the electrical windings and magnet wire found in the stator.

[0144] A better understanding of the present disclosure and its many advantages may be clarified with the following examples. The following examples are illustrative and not limiting in scope or spirit. Those skilled in the art will readily understand that variations of the components, methods, steps, and devices described in these examples can be used. Unless otherwise specified or apparent from the context of the following examples and discussion throughout this disclosure, all percentages, ratios, and parts described in this disclosure are by weight. Unless otherwise noted, exemplary reactions described herein and throughout this disclosure were generally carried out in 500 mL flasks with overhead stirring, a condenser, a temperature probe, and a nitrogen supply. If necessary, reactions were heated using an isomantle. Example

[0145] The insulated magnet wires were evaluated for breakdown voltage after aging in the comparative and inventive lubricating and cooling fluids. The breakdown voltage was measured for six stranded wires using the AC breakdown voltage as specified in Sections 70-76 of ASTM D1676-17 and the parameters specified in Table 9. Each wire was conditioned in accordance with Section 3.8.4 of ANSI NEMA Magnet Wire Standard 1000-2018. The stranded wires were placed in glass containers and immersed in approximately 75 grams of either the comparative or inventive lubricating and cooling fluid and approximately 1500 ppm water. Each container was aged at approximately 150°C for five days. The water added to the containers increased the severity of the test. After aging, the samples were allowed to cool to room temperature. The wires were removed from the containers and washed four times with heptane. The wires were then air-dried. The insulation around each wire was removed approximately 1 millimeter from the tip. Electrodes were then connected to the exposed wire tips for testing.

[0146] The following ester base oils were tested in the base oil systems of comparative and inventive lubricating and cooling fluids: In each fluid, the base oil system included (i) one of the ester base oils described below and (ii) at least one other API Group IV polyalphaolefin base oil. Ester base oil 1 (E-1): A dibasic ester based on bis(6-methylheptyl) adipate was a branched diester with six internal carbons in the acid moiety and eight carbons in the alcohol moiety. This branched diester had a KV 100C of approximately 2.7 cSt and approximately 23.7 mole percent ester groups (the ester group is a -C(O)O- group; E-1 has two such ester groups). Ester base oil 2 (E-2): A dibasic ester based on bis(8-methylnonyl) adipate was a branched diester with 6 internal carbons in the acid moiety and 10 carbons in the alcohol moiety. This branched diester had a KV 100C of 3.5 cSt and approximately 20.6 mole percent ester groups (the ester group is a -C(O)O- group; E-2 has two such ester groups). Ester base oil 3 (E-3): A linear monoester (C) having approximately 16 to 18 carbon atoms in the acid portion and 20 linear carbon atoms in the alcohol portion. 16~18 -Alkyl-COO-C 20 This monoester had a KV 100C of about 5.4 cSt and about 7.7 mole percent ester groups (an ester group is a -C(O)O- group, and E-3 has one such ester group).

[0147] The following calcium or magnesium overbased detergents were tested in comparative and inventive lubricating and cooling fluids. ● Detergent 1 (DET-1): An overbased calcium sulfonate detergent (approximately 300 TBN, 11.9% calcium, and 25% soap content). ● Detergent 2 (DET-2): Overbased magnesium sulfonate detergent (approximately 400 TBN, 9.6% magnesium).

[0148] Each comparative example and inventive fluid also contained the same amounts and set of additional fluid additives, which included dispersants, friction modifiers, antioxidants, metal passivators, extreme pressure agents, antifoam agents, and demulsifiers.

[0149] Example 1

[0150] An insulated 15 American wire gauge (AWG) magnet wire (Wire A) having a polyester(amide)(imide) inner insulation overcoated with a polyamideimide outer insulation layer and a thermal rating of 200°C was aged for 5 days at 150°C in the comparative and inventive fluids listed in Tables 2-4 below. After aging, the wire was washed in heptane and the breakdown voltage was measured as reported in each table and shown in the graph of Figure 1. A second 15 AWG magnet wire (Wire B) having a single polyester insulation layer and a thermal rating of 180°C was also tested for comparison in Table 2. The base oil system included the ester base oil and PAO base oil listed in each table.

[0151] [Table 2] 1 PAO: 100cSt at KV100 2 PAO: 4cSt at KV100 * Metal content was calculated from the amount of calcium or magnesium provided by Det-1 or Det 2. No other sources of calcium or magnesium were present in the fluid. ** The ratio of metal to ester groups in the base oil system is the ppm of detergent metal divided by the mole percent of ester groups in the base oil system (e.g., the ratio for Fluid C-1 was calculated from 214 ppm calcium from the detergent and 23.7 mole % ester groups from the E-1 ester base oil present at 10% in the base oil system, i.e., 214 / (23.7% x 10%) = 90.3).

[0152] [Table 3] 1 PAO: 100cSt at kV100C * Metal content was calculated from the amount of calcium provided by Det-1. No other calcium sources were present in the fluid. **The ratio of metal to ester groups in the base oil system is the ppm of detergent metal divided by the mole percent of ester groups in the base oil system (e.g., the ratio for Fluid C-3 was calculated from 214 ppm calcium from the detergent and 20.6 mole % ester groups from the E-2 ester base oil present at 10% in the base oil system, i.e., 214 / (20.6% x 10%) = 104.0).

[0153] [Table 4] 1 PAO: 100cSt at kV100C * Metal content was calculated from the amount of calcium provided by Det-1. No other calcium sources were present in the fluid. ** The ratio of metal to ester groups in the base oil system is the ppm of detergent metal divided by the mole percent of ester groups in the base oil system (e.g., the ratio for Fluid C-4 was calculated from 214 ppm calcium from the detergent and 7.7 mole % ester groups from the E-3 ester base oil present at 10% in the base oil system, i.e., 214 / (7.7% x 10%) = 278.0).

[0154] Figure 1 contains a chart of breakdown voltage versus the ratio of detergent metal to mole percent of ester groups (-C(O)O-) in the base oil system. As shown in the box in the upper left corner, fluids having ratios of about 70 or less (or from about 10 to about 70) achieved high breakdown voltages of over 10,000 volts when combined with Wire A.

[0155] It should be noted that, as used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless expressly and unambiguously limited to one referent. Thus, for example, a reference to an "antioxidant" includes two or more different antioxidants. As used herein, the term "comprises" and grammatical variations thereof are intended to be open-ended such that the recitation of items in a list does not exclude other similar items that may be substituted for or added to the listed items.

[0156] For purposes of this specification and the appended claims, unless otherwise indicated, all numbers expressing quantities, percentages, or proportions, and other numerical values used in the specification and claims should be understood as being modified in all instances by the term "about." Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and appended claims are approximations that may vary depending upon the desired properties sought to be obtained by the present disclosure. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

[0157] It is understood that each component, compound, substituent, or parameter disclosed herein should be construed as disclosed for use alone or in combination with one or more of any and all other components, compounds, substituents, or parameters disclosed herein.

[0158] It is further understood that each range disclosed herein should be construed as a disclosure of each specific value within the disclosed range having the same number of significant digits. Thus, for example, a range of 1 to 4 should be construed as an explicit disclosure of not only the values 1, 2, 3, and 4, but also any range of such values.

[0159] 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 for the same component, compound, substituent, or parameter. Thus, the present disclosure should be interpreted as a disclosure of all ranges derived by combining each lower limit of each range with each upper limit of each range, or each specific value within each range, or by combining each upper limit of each range with each specific value within each range. It is further understood that any range between the endpoints within a broad range is also contemplated herein. Thus, a range of 1 to 4 also means ranges of 1 to 3, 1 to 2, 2 to 4, 2 to 3, etc.

[0160] Furthermore, a specific amount / value of a component, compound, substituent, or parameter disclosed in the description or examples should be construed as a disclosure of either a lower or upper limit of a range and, therefore, can be combined with any other lower or upper limit of a range or specific amount / value for the same component, compound, substituent, or parameter disclosed elsewhere in this application to form a range for that component, compound, substituent, or parameter.

[0161] While particular embodiments have been described, alternatives, modifications, variations, improvements, and substantial equivalents may occur that are not presently anticipated or presently unforeseeable to Applicants or others skilled in the art. Accordingly, the appended claims as filed, and the appended claims as they may be amended, are intended to embrace all such alternatives, modifications, variations, improvements, and substantial equivalents.

Claims

1. 1. A driveline for an electric or hybrid electric vehicle, the driveline comprising: an electric motor including an insulated magnet wire with an insulating coating having a thermal rating of 190°C to 210°C; a lubricating and cooling fluid in contact with the insulating coating of the insulated magnet wire of the electric motor; the lubricating and cooling fluid comprises a detergent system providing at least 50 ppm metals to the fluid; and a base oil system comprising a first base oil of lubricating viscosity blended with an ester base oil; 1. A driveline wherein the base oil system comprises at least 20 weight percent of the ester base oil, and the ratio of the metal content (in ppm) provided by the detergent system to the percent ester groups in the base oil system of the lubricating and cooling fluid on a formula weight basis is 70 or less.

2. 10. The driveline for a hybrid or hybrid-electric vehicle of claim 1, wherein the insulating coating of the insulated magnet wire comprises one or more layers, the layer in contact with the lubricating and cooling fluid comprising polyamide, polyimide, poly(amide / imide), combinations thereof, blends thereof, or copolymers thereof.

3. 10. The driveline for a hybrid or hybrid-electric vehicle of claim 1, wherein the insulated magnet wire in contact with the lubricating and cooling fluid has a breakdown voltage of 10,000 volts or greater.

4. 3. The driveline for a hybrid or hybrid electric vehicle of claim 2, wherein said insulated magnet wire has an AWG gauge of 14 to 30.

5. the ester base oil comprises a branched diester, and / or the branched diester is a reaction product of one or more dicarboxylic acids having an internal carbon chain length of 6 to 10 and one or more alcohols having a branched carbon chain length of 6 to 12 carbons, and / or the ester base oil comprises a monoester and / or a diester having the structure of Formula I, 【Chemical 1】 In the formula, R 1 is a carbon chain having m-2 carbons, m is an integer from 6 to 10, and R 2 and R 3 10. The driveline for a hybrid or hybrid electric vehicle of claim 1, wherein: are the same or different and comprise a C8 to C20 straight or branched alkyl chain; and n is an integer of 0 or 1.

6. 2. The driveline for a hybrid or hybrid electric vehicle of claim 1, wherein the ester base oil is selected from a dibasic ester based on bi(6-methylheptyl) adipate, a dibasic ester based on bis(8-methylnonyl) adipate, or a linear monoester having 16 to 18 carbons in its acid portion and 20 linear carbons in its alcohol portion, or a combination thereof.

7. 10. The driveline for a hybrid or hybrid-electric vehicle of claim 1, wherein the detergent system comprises alkali or alkaline metal salts of phenates, sulfonates, calixarates, salixrates, salicylates, carboxylic acids, sulfurized derivatives thereof, or combinations thereof, and / or the alkali or alkaline metal comprises calcium, magnesium, potassium, sodium, lithium, barium, or mixtures thereof, and / or the detergent system provides 800 ppm or less of said metals.

8. 10. The driveline for a hybrid or hybrid electric vehicle of claim 1, wherein the first base oil of the base oil system is a mineral base oil or a synthetic base oil and / or the first base oil of the base oil system is a polyalphaolefin.

9. 1. A driveline for a hybrid or hybrid electric vehicle, the driveline comprising: an electric motor including an insulated magnet wire having an insulating coating thereon, the insulating coating comprising polyamide, polyimide, poly(amide / imide), combinations thereof, blends thereof, or copolymers thereof; a lubricating and cooling fluid in contact with the insulating coating of the insulated magnet wire of the electric motor; the lubricating and cooling fluid comprises a detergent system providing at least 50 ppm metals to the fluid; and a base oil system comprising a first base oil of lubricating viscosity blended with an ester base oil, the base oil system comprising at least 20 weight percent of the ester base oil; the ratio of the metal content (in ppm) provided by the detergent system to the percent ester groups in the base oil system, on a formula weight basis, is 70 or less; The driveline, wherein the insulating coating of the insulated magnet wire has a thermal rating of 190°C to 200°C.

10. the ester base oil comprises a branched diester, and / or the branched diester is a reaction product of one or more dicarboxylic acids having an internal carbon chain length of 6 to 10 and one or more alcohols having a branched carbon chain length of 6 to 12 carbons, and / or the ester base oil comprises a monoester and / or a diester having the structure of Formula I, 【Chemistry 2】 In the formula, R 1 is a carbon chain having m-2 carbons, m is an integer from 6 to 10, and R 2 and R 3 10. The driveline for a hybrid or hybrid electric vehicle of claim 9, wherein are the same or different and comprise a C8 to C20 straight or branched alkyl chain, and n is an integer of 0 or 1.

11. 10. The driveline for a hybrid or hybrid electric vehicle of claim 9, wherein the ester base oil is selected from a dibasic ester based on bi(6-methylheptyl)adipate, a dibasic ester based on bis(8-methylnonyl)adipate, or a linear monoester having 16 to 18 carbons in its acid portion and 20 linear carbons in its alcohol portion, or a combination thereof.

12. 10. The driveline for a hybrid or hybrid-electric vehicle of claim 9, wherein the detergent system comprises alkali or alkaline metal salts of phenates, sulfonates, calixarates, salixrates, salicylates, carboxylic acids, sulfurized derivatives thereof, or combinations thereof, and / or the alkali or alkaline metal comprises calcium, magnesium, potassium, sodium, lithium, barium, or mixtures thereof.

13. 10. The driveline for a hybrid or hybrid-electric vehicle of claim 9, wherein the detergent system provides 800 ppm or less of the metals.

14. 10. The driveline for a hybrid or hybrid-electric vehicle of claim 9, wherein the insulated magnet wire in contact with the lubricating and cooling fluid has a breakdown voltage of 10,000 volts or greater.

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