Lubricating fluid for electric motor

Abstract

An electric motor lubricating fluid for an electric motor system includes a lubricating base oil, a tolyltriazole resist, an oil-soluble phosphorus antiwear additive, and a sulfonate detergent in an amount such that effective performance in terms of copper leaching and extreme pressure wear is facilitated when tolyltriazole is present.

Description

Technical Field

[0001] This disclosure relates to methods of using lubricating fluids and lubricating fluids for electric motor systems. Specifically, the disclosed methods and compositions relate to lubricating fluids suitable for electric or hybrid electric vehicles, comprising a toluenetriazole corrosion inhibitor, ashless dialkyl dithiophosphate, and a detergent to achieve copper corrosion and extreme pressure properties. Background Technology

[0002] The main challenge in developing lubricants for electric vehicle powertrains is to achieve acceptable extreme pressure performance while minimizing copper leaching to ensure compatibility with electronic components in the electric vehicle powertrain.

[0003] Tolyltriazole compounds (such as methylbenzotriazole) are effective metal passivators that inhibit copper leaching into lubricants, but they have been found to adversely affect the performance of certain extreme pressure additives. For example, combining tolyltriazole with ashless dialkyl dithiophosphate extreme pressure additives in electric vehicle powertrain lubricants results in a decrease in the destructive load level (FLS) in FZG performance (e.g., A10 / 16.6R / 120 wear test of CECL-84-02). Removing tolyltriazole from the composition improves the FZG FLS, but increases copper leaching. Summary of the Invention

[0004] In one embodiment, this document describes an electric motor lubricating fluid suitable for electric or hybrid electric vehicles. In one aspect of this embodiment, the electric motor lubricating fluid comprises one or more base oils having a lubricating viscosity; at least about 1 ppm of nitrogen provided by a toluenetriazole corrosion inhibitor; an oil-soluble phosphorus anti-wear additive comprising ash-free dialkyl dithiophosphate, providing the electric motor lubricating fluid with about 40 ppm to 150 ppm of phosphorus and about 85 ppm to about 315 ppm of sulfur; a succinimide dispersant derived from a hydrocarbon-substituted dicarboxylic acid or anhydride reacting with a polyalkylene polyamine having one or more primary or secondary amines, wherein the one or more primary or secondary amines are post-treated with an end-capping agent; a sulfonate detergent contributing about 0.02 to about 1.9 TBN (ASTM D2896) to the electric motor lubricating fluid; and wherein the electric motor lubricating fluid contains less than about 500 ppm of sulfur and at least about 70 ppm of phosphorus.

[0005] In other methods or embodiments, the electric motor lubricating fluid of the preceding paragraph may include other features or embodiments in any combination. These other features or embodiments may include one or more of the following: wherein the toluenetriazole resist comprises methyl-1H-benzotriazole; and / or wherein the ratio of the amount (ppm) of phosphorus delivered to the fluid from the ashless dialkyl dithiophosphate to the amount (ppm) of nitrogen delivered to the fluid from the toluenetriazole resist (EP Phos+CI nitrogen) relative to the TBN factor is about 70,000 or less, and wherein the TBN factor is the TBN (ASTM) delivered to the fluid by the detergent. D2896) divided by the amount of metal delivered from the detergent to the fluid (ppm) (TBN / Det metal); and / or wherein the sulfonate detergent is calcium sulfonate, and provides about 30 ppm to about 600 ppm of calcium to the electric motor lubricating fluid; and / or wherein the oil-soluble phosphorus anti-wear additive comprising ashless dialkyl dithiophosphate is prepared by a method comprising the steps of: (a) reacting an organic hydroxy compound with phosphorus pentasulfide to form a reaction product, and (b) further reacting the reaction product with an unsaturated carboxylic acid to form an oil-soluble phosphorus anti-wear additive comprising ashless dialkyl dithiophosphate; and / or wherein the ashless dialkyl dithiophosphate comprises a compound of formula I or a salt thereof:

[0006] (Form IIa)

[0007] R4 and R5 are independently C1 to C1. 10 The ashless dialkyl dithiophosphate comprises a straight-chain or branched alkyl group, and R6 is -H or -CH3; and / or wherein the ashless dialkyl dithiophosphate comprises 3-[[bis(2-methylpropoxy)thiophosphono]thio]-2-methylpropionic acid; and / or wherein the succinimide dispersant is post-treated with a phosphorus-containing compound and / or a boron-containing compound; and / or wherein the succinimide dispersant delivers about 20 ppm to about 100 ppm of phosphorus and about 5 ppm to about 50 ppm of boron to the motor lubricating fluid; and / or wherein the sulfonate detergent is provided in an amount contributing about 0.2 to about 0.6 TBN; and / or wherein the motor lubricating fluid exhibits about 30 ppm or less of copper leaching according to ASTM D130; and / or wherein the motor lubricating fluid has a destructive load class of 8 or higher in the FZG A10 / 16.6R / 120 test of ASTM D5182; and / or wherein the motor lubricating fluid contains less than about 300 ppm of sulfur.

[0008] In other methods or embodiments, this document describes a method for lubricating a powertrain component including an electric motor. In various aspects of this method or embodiment, the method includes lubricating the powertrain component with an electric motor lubricating fluid, wherein the electric motor lubricating fluid contacts portions of the electric motor; wherein in the electric motor, the lubricating fluid comprises (i) one or more base oils having a lubricating viscosity, (ii) at least about 1 ppm of nitrogen provided by a toluenetriazole corrosion inhibitor; and (iii) an oil-soluble phosphorus anti-wear additive comprising ashless dialkyl dithiophosphate, providing the electric motor lubricating fluid with about 40 ppm to about 150 ppm of phosphorus and about 85 ppm to about 3 ppm of nitrogen. 15 ppm sulfur, (iv) succinimide dispersant derived from a hydrocarbon-substituted dicarboxylic acid or anhydride reacting with a polyalkylene polyamine having one or more primary or secondary amines, wherein the one or more primary or secondary amines are post-treated with a capping agent; (v) sulfonate detergent contributing about 0.02 to about 1.9 TBN to the motor lubricating fluid; and (vi) wherein the motor lubricating fluid contains less than about 500 ppm sulfur and at least about 70 ppm phosphorus; and wherein the motor lubricating fluid exhibits about 30 ppm or less copper leaching according to ASTM D130 and has a destructive load class of 8 or higher in the FZG A10 / 16.6R / 120 test of ASTM D5182.

[0009] In other methods or embodiments, the methods in the preceding paragraph may include other steps, methods, embodiments, or features in any combination. These other steps, methods, embodiments, or features may include one or more of the following: wherein the triazole resist comprises methylbenzotriazole; and / or wherein the ratio of the amount (ppm) of phosphorus delivered from the ashless dialkyl dithiophosphate to the amount (ppm) of nitrogen (EP Phos+CI nitrogen) delivered from the toluenetriazole resist to the fluid is about 70,000 or less relative to the TBN factor, and wherein the TBN factor is the TBN (ASTM) delivered to the fluid by the detergent. D2896) divided by the amount of metal delivered from the detergent to the fluid (ppm) (TBN / Det metal); and / or wherein the sulfonate detergent is calcium sulfonate, and provides about 30 ppm to about 600 ppm of calcium to the electric motor lubricating fluid; and / or an oil-soluble phosphorus anti-wear additive comprising an ashless dialkyl dithiophosphate is prepared by a method comprising the steps of: (a) reacting an organic hydroxy compound with phosphorus pentasulfide to form a reaction product, and (b) further reacting the reaction product with an unsaturated carboxylic acid to form an oil-soluble phosphorus anti-wear additive comprising an ashless dialkyl dithiophosphate; and / or wherein the ashless dialkyl dithiophosphate comprises a compound of formula I or a salt thereof:

[0010] (Form IIa)

[0011] R4 and R5 are independently C1 to C1. 10 The ashless dialkyl dithiophosphate comprises a straight-chain or branched alkyl group, and R6 is -H or -CH3; and / or wherein the ashless dialkyl dithiophosphate comprises 3-[[bis(2-methylpropoxy)thiophosphono]thio]-2-methylpropionic acid; and / or wherein the succinimide dispersant is post-treated with a phosphorus-containing compound and / or a boron-containing compound; and / or wherein the succinimide dispersant delivers about 20 ppm to about 100 ppm of phosphorus and about 5 ppm to about 50 ppm of boron to the electric motor lubricating fluid; and / or wherein the sulfonate detergent is provided in an amount contributing about 0.2 to about 1.6 TBN; and / or wherein the electric motor lubricating fluid contains less than about 300 ppm of sulfur.

[0012] In other embodiments, the use of any embodiment of the electric motor lubricating fluid of the present invention is also provided for lubricating powertrain components of electric or hybrid electric vehicles and for achieving copper leaching of about 30 ppm or less according to ASTM D130 and / or for achieving a destructive load level (FLS) of 8 or higher in the FZG A10 / 16.6R / 120 test of ASTM D5182.

[0013] Other embodiments of this disclosure will be apparent to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. Attached Figure Description

[0014] Figure 1 This is a graph showing the FZG destructive load level and copper leaching relative to the ratios of anti-wear phosphorus, toluenetriazole nitrogen, and detergent TBN factor as described herein. Detailed Implementation

[0015] According to an exemplary embodiment, this document describes an electric motor lubricating fluid suitable for electric or hybrid electric vehicles that achieves low copper leaching while also providing acceptable FZG destructive load level (FLS) wear performance. It was found that toluenetriazole resist adversely affects the extreme pressure properties of ashless dialkyl dithiophosphate, which can lead to unacceptably low FZG wear FLS as measured by the A10 / 16.6R / 90 test of CEC L-84-02. While not wishing to be limited by theory, it is believed that toluenetriazole compounds and ashless dialkyl dithiophosphate compete for surface activity, thereby interfering with and / or inhibiting ashless dialkyl dithiophosphate from providing a sufficient protective layer on the metal surface, resulting in reduced FZG wear performance.

[0016] This application relates to the discovery that by adding a selected TBN detergent contribution (ASTM D2896) relative to the nitrogen content of the extreme pressure agent and the tolyltriazole resist, lubricating fluids suitable for electric vehicle powertrains can overcome any adverse effects of tolyltriazole resist from dialkyl dithiophosphate on extreme pressure performance. The selected TBN contribution is primarily provided by one or more neutral to highly basic sulfonate detergents, contributing approximately 0.02 to approximately 1.9 (in other methods, approximately 0.04 to approximately 1.6, or approximately 0.2 to approximately 1.6, or approximately 0.2 to approximately 0.6) of TBN (ASTM D2896) to the electric motor lubricating fluid. As shown by the examples and some embodiments, a unique relationship has been discovered whereby the detergent TBN (ASTM D2896) is balanced relative to the amount of detergent metal (preferably calcium), and then further balanced relative to the phosphorus content provided by the extreme pressure additive and the nitrogen content provided by the tolyltriazole resist. As discussed in more detail below, this fluid relationship is defined by the ratio of approximately 70,000 or less of phosphorus (in ppm) delivered from ashless dialkyl dithiophosphoric acid to nitrogen (in ppm) delivered from the toluenetriazole resist (e.g., EP phosphorus + CI nitrogen) relative to the TBN factor, and wherein the TBN factor is the amount of TBN delivered to the fluid by the detergent (ASTM D2896) divided by the amount of metal delivered to the fluid by the detergent (in ppm) (TBN / detergent metal). Preferably, the detergent metal is calcium. For example, Figure 1 Examples of embodiments of the lubricants described herein are illustrated, wherein the ratio is about 70,000 or lower, and reflects the desired FZG performance (e.g., 8 or higher FLS) and desired copper leaching performance (e.g., 30 ppm or less copper leaching) in lubricants containing both toluenetriazole resist and ashless dialkyl dithiophosphate. The examples below illustrate in more detail how to calculate the ratio as defined herein.

[0017] Conventional powertrain lubricants may also contain some active sulfur, which can be harmful to copper wiring or other copper components near the lubricant found in electric motors. Therefore, it is generally preferred to formulate low-sulfur electric motor lubricating fluids to reduce corrosion of copper components. In embodiments, the electric motor lubricating fluids described herein also contain less than about 500 ppm of total sulfur (in other methods, less than about 400 ppm or less than about 300 ppm of sulfur, and in some methods, about 50 ppm or more, about 100 ppm or more, or about 200 ppm or more), and at least about 50 ppm of total phosphorus (in this method, about 50 ppm to about 200 ppm of phosphorus or about 50 ppm to about 150 ppm of total phosphorus).

[0018] Toluenetriazole corrosion inhibitor

[0019] In the methods and embodiments described herein, the electric motor lubricating fluid of this disclosure comprises at least about 2 ppm of tolyltriazole corrosion inhibitor, at least about 4 ppm of tolyltriazole corrosion inhibitor, at least about 5 ppm of tolyltriazole corrosion inhibitor, at least about 10 ppm of tolyltriazole corrosion inhibitor, at least about 20 ppm of tolyltriazole corrosion inhibitor, at least about 30 ppm of tolyltriazole corrosion inhibitor, at least about 50 ppm of tolyltriazole corrosion inhibitor, at least about 70 ppm of tolyltriazole corrosion inhibitor, or at least about 90 ppm of tolyltriazole corrosion inhibitor. In other embodiments, the electric motor lubricating fluid of this disclosure comprises about 150 ppm or less of tolyltriazole corrosion inhibitor, about 100 ppm or less of tolyltriazole corrosion inhibitor, or about 70 ppm or less of tolyltriazole corrosion inhibitor, or about 40 ppm or less of tolyltriazole corrosion inhibitor. Other ranges between such endpoints are also within the scope of this disclosure. The tolyltriazole compound (e.g., methyl-1H-benzotriazole or its isomers) contains about 31.5% by weight of nitrogen. Therefore, in other embodiments where nitrogen contributes to the lubrication fluid of the electric motor of this disclosure, the tolyltriazole provided contributes in amounts contributing at least about 1 ppm of tolyltriazole nitrogen, at least about 2 ppm of tolyltriazole nitrogen, at least about 4 ppm of tolyltriazole nitrogen, at least about 5 ppm of tolyltriazole nitrogen, at least about 10 ppm of tolyltriazole nitrogen, at least about 20 ppm of tolyltriazole nitrogen, or at least about 25 ppm of tolyltriazole nitrogen. In other embodiments, the tolyltriazole is provided in amounts contributing about 35 ppm or less of tolyltriazole nitrogen, about 30 ppm or less of tolyltriazole nitrogen, or about 25 ppm or less of tolyltriazole nitrogen, or about 15 ppm or less of tolyltriazole nitrogen. Other ranges within such specified endpoints are also within the scope of this disclosure.

[0020] In other embodiments, the toluenetriazole resist is a hydrocarbon-substituted benzotriazole compound having the structure of Formula I or a tribologically acceptable salt thereof:

[0021] (Formula I)

[0022] Each R1 is independently a hydrocarbon group having 1 to 10 carbon atoms, x is an integer from 1 to 4, and R2 is hydrogen or a hydrocarbon group containing 1 to 10 carbon atoms. In other methods, each R1 is independently a straight-chain or branched alkyl group or an aryl group, such as phenyl, and more preferably, R1 is independently a straight-chain or branched alkyl group having 1 to 8 carbon atoms (1 to 6 carbon atoms in other methods, and 1 to 4 carbon atoms in other methods, and most preferably, a methyl group). Examples suitable for R1 are alkyl groups, including methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and tert-butyl. Preferably, methyl and ethyl are alkyl groups of R1, and methyl is most preferably used for R1. As mentioned above, x is an integer from 1 to 4. In other embodiments, the upper limit of the integer x is preferably 3, and more preferably 2. x is particularly preferably 1.

[0023] In one embodiment, R2 is preferably hydrogen or a straight-chain or branched alkyl group or an aryl group, such as phenyl. More preferably, R2 is hydrogen or a straight-chain or branched alkyl group. Most preferably, R2 is hydrogen. When R2 is a hydrocarbon group containing 1 to 10 carbon atoms, it preferably contains 1 to 8 carbon atoms, more preferably 1 to 6 carbon atoms, and even more preferably 1 to 4 carbon atoms. In this regard, preferred embodiments of R2 are alkyl groups, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and tert-butyl, with methyl and ethyl being particularly preferred, and methyl being the most preferred. In other embodiments, R2 is hydrogen.

[0024] In a particularly preferred embodiment, the integer x is 1, R1 is a straight-chain or branched alkyl group containing 1 to 4 carbon atoms, such as methyl or ethyl (typically methyl), and R2 is hydrogen or a straight-chain or branched alkyl group containing 1 to 4 carbon atoms, such as methyl or ethyl (R2 is typically hydrogen). Examples of preferred compounds of formula I are tolyltriazole and hydrocarbon-substituted benzotriazoles, wherein tolyltriazole (e.g., methylbenzotriazole, such as methyl-1H-benzotriazole) is particularly preferred for the compositions herein.

[0025] Oil-soluble phosphorus extreme pressure additives :

[0026] In the method or implementation, the electric motor lubricating fluid of this invention also comprises an oil-soluble phosphorus extreme pressure additive in the form of an ashless dialkyl dithiophosphate extreme pressure additive.

[0027] In one embodiment, the ashless dialkyl dithiophosphate extreme pressure additive provides the electric motor lubricating fluid with about 40 ppm to about 150 ppm of phosphorus (in other methods, about 45 ppm to about 100 ppm of phosphorus or about 50 ppm to about 80 ppm of phosphorus) and about 85 ppm to about 315 ppm of sulfur (in other methods, about 80 ppm to about 300 ppm of sulfur, or about 95 ppm to about 210 ppm of sulfur, or about 95 ppm to about 170 ppm of sulfur). As shown by the following examples, when the electric motor lubricating fluid contains the above-mentioned toluenetriazole compound as a corrosion inhibitor in combination with ashless dialkyl dithiophosphate, it has an adverse effect on the extreme pressure performance of FZG.

[0028] In one embodiment, the ashless dialkyl dithiophosphate has the structure of a compound of formula II or a salt thereof.

[0029] (Formula II)

[0030] In equation II above, R4 and R5 are each independently a straight chain or a branched chain C1 to C2. 10 Hydrocarbon group, and R7 in formula II is C1 to C2. 10 Straight-chain or branched carboxyl groups or C1 to C1 groups 10 A straight-chain or branched alkyl ester group of alkyl alkanoates. Preferably, R4 and R5 of Formula II are each C3 to C8 straight-chain or branched alkyl groups and R7 of Formula II is derived from 2-methylpropionic acid, such that the phosphorus product (or its salt) has the structure of Formula II:

[0031] (Form IIa)

[0032] Where R4 and R5 are as defined relative to Equation II above, and are independently C1 to C... 10 Or a C3 to C8 straight-chain or branched alkyl group (preferably a branched C4 group), and R6 of Formula II above is -H or -CH3. In some methods or embodiments, the oil-soluble phosphorus anti-wear additive of the compositions and methods herein is preferably 3-[[bis(2-methylpropoxy)thiophosphono]thio]-2-methylpropionic acid.

[0033] In some methods, an oil-soluble phosphorus anti-wear additive comprising ashless dialkyl dithiophosphate is prepared by a method comprising the following steps: (a) reacting an organic hydroxy compound with phosphorus pentasulfide (in some forms, its monomer or dimer) to form a reaction product, and (b) further reacting the reaction product with an unsaturated carboxylic acid to form an oil-soluble phosphorus anti-wear additive comprising ashless dialkyl dithiophosphate.

[0034] Suitable organic hydroxyl compounds may include straight-chain alcohols, branched alcohols, hydroxyaryl compounds (such as phenol and naphthol), substituted aryl hydroxyl compounds (such as dipentylphenol), or any other hydroxyl organic material wherein the hydroxyl group will react with phosphorus pentasulfide. In one method, the starting alcohol is a saturated alcohol or a substituted aryl hydroxyl compound, such as an aryl hydroxyl compound substituted with a saturated alkyl radical. In some methods, the organic hydroxyl compound may be C1 to C2. 10 (In other methods, C1 to C6) straight-chain or branched alcohols, hydroxyaryl compounds, or mixtures thereof, such as methanol, ethanol, propanol, isopropanol, butanol, isobutanol, tert-butanol, sec-butanol, phenol, naphthol, pentanol, hexanol, isohexanol, octanol, decanol, dodecyl alcohol, octadecyl alcohol, 2-ethylhexanol, 4-methyl-2-pentanol, phenyl alcohol, butylphenyl alcohol, cyclohexanol, methylcyclopentanol, propenyl alcohol, butenyl alcohol, or combinations thereof. Preferred organic hydroxyl compounds herein include C1 to C4 alcohols, such as ethanol, propanol, or isopropanol, and most preferably, isobutanol.

[0035] Suitable unsaturated carboxylic acids that form the oil-soluble phosphorus anti-wear additives of this disclosure may include a wide variety of unsaturated carboxylic acids or fatty acids. Preferred unsaturated carboxylic acids may include C1 to C2. 20 Unsaturated fatty acids, such as acrylic acid, methacrylic acid, 2-ethylacrylic acid, or combinations thereof, with methacrylic acid being the most preferred. (As used herein, (meth)acrylic acid refers to acrylic acid or methacrylic acid.)

[0036] Succinimide dispersant :

[0037] The electric motor lubricating fluid described herein also comprises a dispersant system having at least one oil-soluble, ashless dispersant, which is a succinimid dispersant derived from a hydrocarbon-substituted dicarboxylic acid or anhydride reacting with a polyalkylene polyamine having one or more primary or secondary amines, and wherein the one or more primary or secondary amines of the dispersant are post-treated with a capping agent. Suitable succinimid dispersants and their preparation are disclosed in at least US 7,897,696 and / or US 4,234,435, which are incorporated herein by reference.

[0038] In one embodiment, the succinimide dispersant of this invention has a hydrocarbon substituent having a number average molecular weight of about 500 to about 5000, about 800 to about 2500, and in one method of this embodiment, preferably derived from polyisobutylene having a number average molecular weight of about 1000 or less, and in another method of this embodiment, preferably derived from polyisobutylene having a number average molecular weight of about 2000 to about 3000. In the method or embodiment, the hydrocarbon portion of the hydrocarbon dicarboxylic acid or anhydride may be derived from a butene polymer, such as a polymer of isobutylene. Suitable polyisobutylenes suitable for this invention include those formed from conventional polyisobutylene or highly reactive polyisobutylene having a terminal vinylidene content of at least 60%, such as 70% to 90% and higher. Suitable polyisobutylenes may include those prepared using a BF3 catalyst. In a preferred embodiment, the dispersant described herein has a relatively low molecular weight; therefore, the number average molecular weight of the polyisobutylene substituents in the dispersant may be from at least about 1,000 or less, and in some cases, from about 500 to about 1,000 or from about 700 to about 1,000, as determined by gel permeation chromatography (GPC) using polystyrene (with a number average molecular weight of 180 to about 18,000) as a calibration reference. In other preferred embodiments, the dispersant described herein has a relatively high molecular weight; therefore, the number average molecular weight of the polyisobutylene substituents in the dispersant may be at least about 2,000, and in some cases, from about 2,000 to about 5,000 or from about 2,000 to about 3,000, as determined by gel permeation chromatography (GPC) using polystyrene (with a number average molecular weight of 180 to about 18,000) as a calibration reference. The GPC method also provides information on the average weight molecular weight distribution; see, for example, WW Yau, JJ Kirkland and DD Bly, “Modern Size Exclusion Liquid Chromatography”, John Wiley and Sons, New York, 1979, which is also incorporated herein by reference.

[0039] The polyisobutylene portion of any embodiment of the dispersant described herein may also have a molecular weight distribution (MWD), also known as a polydispersity index (PDI), as determined by the ratio of weight-average molecular weight (Mw) to number-average molecular weight (Mn). In some methods or embodiments, a suitable polyisobutylene portion may have a Mw / Mn ratio of less than about 3.0, or less than about 2.8, or less than about 2.5, and in other methods, a suitable polyisobutylene substituent has a polydispersity of about 1.5 to about 3.0, or about 2.0 to about 3.0.

[0040] The dicarboxylic acids or anhydrides suitable for forming dispersants described herein can be selected from carboxylic acid reactants, such as maleic anhydride, maleic acid, fumaric acid, malic acid, tartaric acid, itaconic acid, itaconic anhydride, citraconic acid, citraconic anhydride, mesoconic acid, ethyl maleic anhydride, dimethyl maleic anhydride, ethyl maleic acid, dimethyl maleic acid, hexyl maleic acid, etc., including the corresponding acidic halides and C1-C4 aliphatic esters. In some methods, the molar ratio of the dicarboxylic acid or anhydride to the hydrocarbon moiety in the reaction mixture used to prepare the hydrocarbon-dicarboxylic acid or anhydride can vary widely. Therefore, the feed molar ratio can vary from 5:1 to 1:5, for example from 3:1 to 1:3. In some embodiments, a particularly suitable molar ratio of acid or anhydride to the hydrocarbon moiety is 1:1 to less than 1.6:1. In other embodiments, another useful feed molar ratio of the dicarboxylic acid or anhydride to the hydrocarbon moiety may be 1:1 to 1.5:1, or 1:1 to 1.4:1, or 1.1:1 to 1.3:1, or 1:1 to 1.2:1.

[0041] Any of many polyalkylene polyamines can be used as the dispersant additives described herein. Non-limiting exemplary polyamines may include aminoguanidine bicarbonate (AGBC), diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA), pentaethylenehexamine (PEHA), and heavy polyamines. Heavy polyamines may comprise mixtures of polyalkylene polyamines having small amounts of polyamine oligomers, such as TEPA and PEHA, but primarily oligomers having seven or more nitrogen atoms, two or more primary amines per molecule, and more extensive branching than conventional polyamine mixtures. Typically, these heavy polyamines have an average of 6.5 nitrogen atoms per molecule. Other non-limiting polyamines that can be used to prepare hydrocarbon-substituted succinimide dispersants are disclosed in US 6,548,458, the disclosure of which is incorporated herein by reference in its entirety. In some embodiments, the feed molar ratio of the hydrocarbon-dicarboxylic acid or anhydride to the polyalkylene polyamine may be from about 1:1 to about 3.0:1. In one embodiment, the dispersant described herein may be a reaction product of polyisobutylene succinic anhydride (PIBSA) and a polyamine (e.g., a heavy polyamine), wherein the feed molar ratio of the polyisobutylene-substituted succinic anhydride to the polyamine is from about 1.7:1 to about 2.5:1.

[0042] As described above, the embodiments of the succinimide dispersants suitable for the lubricating fluids of electric motors described herein are post-treated with end-capping agents, and specifically, one or more primary or secondary amines of the succinimide dispersant are post-treated with end-capping agents. As shown in the examples below, uncapped succinimide dispersants also do not provide suitable performance in the context of corrosion and extreme pressure properties. Suitable end-capping agents include, but are not limited to, boron compounds, urea compounds, thiourea compounds, dimercaptothiadiazole compounds, carbon disulfide, aldehydes, ketones, lactones, carboxylic acids, hydrocarbon-substituted succinic anhydrides, maleic anhydrides, naphthalenecarboxylic anhydrides, nitriles, epoxides, carbonates, ethylene carbonate, cyclic carbonates, aromatic glycidyl ethers, acidic acids, hindered phenolic esters, and / or phosphorus compounds. (See, for example, US 7,645,726; US 7,214,649; US 8,048,831; and US 5,241,003, the entire contents of which are incorporated herein by reference.) Preferably, the post-treatment capping agent is one or more boron compounds, one or more phosphorus compounds, or both boron and phosphorus compounds.

[0043] In one embodiment, suitable boron compounds that can be used as capping agents in the dispersants forming this document include any boron compound or mixture of boron compounds capable of introducing boron-containing substances into an ashless dispersant. Any organic or inorganic boron compound capable of carrying out this reaction can be used. Thus, boron oxide, boron oxide hydrate, boron trifluoride, boron tribromide, boron trichloride, HBF4 boron acids such as borous acid (e.g., alkyl-B(OH)2 or aryl-B(OH)2), boric acid (i.e., H3BO3), tetraboric acid (i.e., H2B5O7), metaboric acid (i.e., HBO2), ammonium salts of these boron acids, and esters of these boron acids can be used. Using boron trihalides in complexes with ethers, organic acids, inorganic acids, or hydrocarbons is a convenient method for introducing boron reactants into the reaction mixture. Such complexes are known, for example, boron trifluoride-diethyl ether, boron trifluoride-phenol, boron trifluoride-phosphoric acid, boron trichloride-chloroacetic acid, boron tribromide-dioxane, and boron trifluoride-methyl ethyl ether.

[0044] In other embodiments, suitable phosphorus compounds that can be used as dispersants for the formation of this document include phosphorus compounds or mixtures of phosphorus compounds capable of introducing phosphorus-containing substances into an ashless dispersant. Therefore, any organic or inorganic phosphorus compound capable of carrying out such a reaction can be used. Thus, such inorganic phosphorus compounds as inorganic phosphoric acid and inorganic phosphorus oxides, including their hydrates, can be used. Typical organophosphorus compounds include full-ester and partial-ester forms of phosphoric acid, such as mono- and di- and tri-esters of phosphate, thiophosphoric acid, dithiophosphoric acid, trithiophosphoric acid, and tetrathiophosphoric acid; mono- and di- and tri-esters of phosphite, thiophosphite, dithiophosphite, and trithiophosphite; trialkylphosphine oxides; trialkylphosphine sulfides; monoalkylphosphonates and dialkylphosphonates (RPO(OR')(OR"), where R and R' are hydrocarbon groups and R" is a hydrogen atom or a hydrocarbon group), and their monothio, dithio, and trithio analogs; monoalkylphosphonates and dialkylphosphonates (RP(OR')(OR"), where R and R' are hydrocarbon groups and R" is a hydrogen atom or a hydrocarbon group) and their monothio and dithio analogs; and so on. Therefore, compounds such as phosphorous acid (H3PO3, sometimes described as H2(HPO3), sometimes called orthophosphorous 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 hypophosphonic acid), pyrophosphorous acid (H4P2O5, sometimes called pyrophosphonic acid), hypophosphonic acid (H3PO), and tripolyphosphoric acid (H5P3O) can be used. 10 ), tetrapolyphosphoric acid (H5P4O) 13 Phosphoric acid includes trimethomorphic phosphoric acid (H3P3O9), phosphorus trioxide, phosphorus tetroxide, and phosphorus pentoxide. Partially sulfur or all-sulfur analogs include tetrathiophosphoric acid (H3PS4), thiophosphoric acid (H3PO3S), dithiophosphoric acid (H3PO2S2), trithiophosphoric acid (H3POS3), sesquisulfide, phosphorus heptasulfide, and phosphorus pentasulfide (P2S5, sometimes called P4S). 10 It can also be used to form the dispersant of this disclosure. Inorganic phosphorus halide compounds, such as PCl3, PBr3, POCl3, PSCl3, etc., can also be used.

[0045] In other embodiments, organophosphorus compounds may be used as capping agents. Exemplary organophosphorus compounds include, but are not limited to, monoesters, diesters, and trimers of phosphoric acid (e.g., trialkyl phosphates, dialkyl monophosphates, monoalkyl diacid phosphates, and mixtures thereof), monoesters, diesters, and trimers of phosphorous acid (e.g., trialkyl phosphite, dialkyl hydrogen phosphite, alkyl diacid phosphite, and mixtures thereof), phosphonates (“primary” RP(O)(OR)2 and “secondary” R2P(O)(OR)), hypophosphonates, and phosphonyl halides (e.g., RP(O)Cl2 and R2P(O)C l), halophosphites (e.g., (RO)PCl2 and (RO)2PCl), halophosphates (e.g., ROP(O)Cl2 and (RO)2P(O)Cl), tertiary pyrophosphates (e.g., (RO)2P(O)-OP(O)(OR)2), and all-sulfur or partially-sulfur analogs of any of the aforementioned organophosphorus compounds, wherein each hydrocarbon group contains up to 100 carbon atoms, preferably up to 50 carbon atoms, more preferably up to 24 carbon atoms, and most preferably up to 12 carbon atoms. Additionally, halophosphine halides (e.g., alkyl tetrahalides, dialkyl trihalides, and trialkyl dihalides) and halophosphines (monohalophosphines and dihalophosphines) are suitable as end-capping agents.

[0046] In other methods, carboxylic acids may also be used as post-treatment reagents, and in such embodiments, they may be saturated or unsaturated mono-, di-, or poly-carboxylic acids. Examples of carboxylic acids include, but are not limited to, maleic acid, fumaric acid, succinic acid, and naphthalic acid (e.g., 1,8-naphthalic acid). Anhydrides may be used as post-treatment reagents and may be selected from monounsaturated anhydrides (e.g., maleic anhydride), alkyl- or alkylene-substituted cyclic anhydrides (e.g., succinic anhydride or glutamic acid anhydride), and aromatic carboxylic anhydrides (including naphthalenedicarboxylic anhydride, such as 1,8-naphthalenedicarboxylic anhydride).

[0047] In embodiments, the method for post-processing any embodiment of the dispersant described herein includes first forming a succinimide product as described above, and then further reacting the succinimide product with a post-processing agent. In some cases, the dispersant described herein may be post-processed with more than one post-processing agent. For example, the dispersant may be post-processed with a boron compound (such as boric acid) and a phosphorus compound (phosphoric acid).

[0048] In one embodiment, when one or more of the dispersants are post-treated (e.g., with one or both of a boron compound and / or a phosphorus compound), the dispersants are post-treated to provide the lubricating composition with at least about 5 ppm of boron and at most 50 ppm of boron and / or to provide the lubricating composition with at least about 20 ppm of phosphorus and at most about 100 ppm of phosphorus. In other methods, the dispersant may be used in the lubricating composition in an amount of about 0.1 wt% to about 10 wt%, or about 0.1 wt% to about 5 wt%, or about 0.1 wt% to 3 wt%, or about 0.5 wt% to about 2 wt%, or about 0.5 wt% to about 1.5 wt%, based on the final weight of the lubricating oil composition. In yet another embodiment, the succinimide dispersant for the electric motor lubricating fluid of this document preferably comprises at least a polyisobutylene moiety having a number average molecular weight of 1000 or less, and in other methods about 500 to about 1000, or in other methods about 700 to about 1000, and having nitrogen of about 0.5 wt% to about 2.5 wt%, boron of about 0.1 wt% to about 0.7 wt%, and phosphorus of about 0.20 wt% to about 1.0 wt%, or in other embodiments, at least a number average molecular weight of between 800 and The polyisobutylene moiety has a number average molecular weight between 1000 and 2000, and contains about 1.0% to about 2.0% nitrogen, about 0.2% to about 0.6% boron and about 0.6% to about 0.9% phosphorus, or in other embodiments, it contains at least a polyisobutylene moiety having a number average molecular weight between 2000 and 3000, and contains about 0.5% to about 1.0% nitrogen, about 0.1% to about 0.3% boron and about 0.2% to about 0.6% phosphorus.

[0049] Cleaning agent

[0050] The electric motor lubricating fluid described herein also includes one or more detergents selected to enhance the effectiveness of toluenetriazole corrosion inhibitors in combination with oil-soluble phosphorus extreme pressure additives in the context of electric motor lubricating fluids. In one embodiment, the detergent is one or more neutral, low-alkaline, or high-alkaline sulfonate detergents (preferably calcium sulfonate detergents) having a total base number (TBN) of about 450 or less (preferably about 0 to about 450), and is provided in an amount to the electric motor lubricating fluid to contribute about 0.02 to about 1.9 TBN (in other cases, about 0.02 to about 1.6, about 0.04 to about 1.6, about 0.04 to about 0.6, or about 0.2 to about 0.6 TBN), and wherein the TBN is measured according to ASTM D2896. Suitable detergents and methods of their preparation are described in more detail in several patent publications, including US 7,732,390; US 4,165,291 and / or US 4,206,062 (and references cited therein), which are incorporated herein by reference.

[0051] As used herein, low-alkaline to neutral detergent additives may have a total base number (TBN) of less than about 200 mg KOH / g, and high-alkaline detergents may have a total base number (TBN) of about 200 mg KOH / g or greater, or about 250 mg KOH / g or greater, or about 350 mg KOH / g or greater, or about 375 mg KOH / g or greater, or about 400 mg KOH / g or greater (wherein the TBN is measured by ASTM D2896). In other embodiments, high-alkaline detergents may have a metal-to-matrix ratio of 1.1:1 or less, or 2:1 or less, or 4:1 or less, or 5:1 or less, or 7:1 or less, or 10:1 or less, or 12:1 or less, or 15:1 or less, or 20:1 or less.

[0052] As illustrated in the examples below, the detergent selection that benefits the effective performance of the combined toluenetriazole resist and oil-soluble phosphorus extreme pressure additive requires proper balance relative to, for example, the amount of detergent metal (e.g., calcium), and in other embodiments, also relative to the phosphorus from the oil-soluble anti-wear compound and the nitrogen from the toluenetriazole resist. As shown in the examples, the selected sulfonate is provided in an amount of about 0.02 to about 1.9 (or about 0.02 to about 1.6, or about 0.2 to about 0.6, or other ranges as described above) of TBN (ASTM D2896) to the electric motor lubricating fluid, and such detergent selection is surprisingly beneficial to the effective performance of both the toluenetriazole resist and the oil-soluble ashless dialkyl dithiophosphate extreme pressure additive when the detergent TBN is properly balanced relative to the detergent metal (e.g., calcium), anti-wear phosphorus, and toluenetriazole nitrogen.

[0053] As shown in the examples and some embodiments, the detergent TBN is first balanced relative to the detergent metal content (e.g., calcium) to produce a TBN factor of about 0.0011 to about 0.0025, wherein the TBN factor is the TBN measured by ASTM D2896 divided by the detergent metal (in ppm) and reflects the amount of TBN provided per ppm of detergent metal. Preferably, the detergent metal is calcium. To improve the performance of the oil-soluble phosphorus anti-wear additive in combination with the toluenetriazole resist, the amount of detergent is further balanced relative to the phosphorus content provided by the extreme pressure additive and the nitrogen content provided by the toluenetriazole resist. That is, an effective fluid relationship was discovered, thereby achieving surprisingly low copper leaching (as per ppm) and high FZG performance (ASTM D5182) with a ratio of approximately 70,000 or less of phosphorus (in ppm) delivered from ashless dialkyl dithiophosphoric acid to nitrogen (in ppm) delivered from toluenetriazole resist (e.g., EP phosphorus + CI nitrogen) relative to the TBN factor (ASTM D5182). In other embodiments, the ratio is approximately 65,000 or less, approximately 60,000 or less, or in other embodiments, approximately 20,000 to approximately 70,000 or approximately 30,000 to approximately 70,000 (or in other embodiments, any other range between such endpoints). For example, Figure 1 An embodiment of the lubricant described herein is illustrated, wherein the fluid ratio is about 70,000 or less, and reflects the desired FZG performance (e.g., 8 or higher FLS) and desired copper leaching performance (e.g., 30 ppm or less copper leaching) in a lubricant comprising both toluenetriazole corrosion inhibitor and ashless dialkyl dithiophosphate. The examples below further illustrate in more detail how to calculate the ratio as defined herein.

[0054] In embodiments, a suitable detergent matrix (e.g., sulfonate) can be salted with an alkali metal or alkaline earth metal, preferably calcium and / or magnesium, and most preferably calcium. Therefore, suitable detergents may include alkali metal or alkaline earth metal salts of petroleum sulfonic acids and long-chain mono- or dialkyl aryl sulfonic acids, wherein the aryl group is benzyl, tolyl, or xylyl. Examples of suitable detergents found to be beneficial to the effective performance of toluenetriazole corrosion inhibitors and oil-soluble ashless dialkyl dithiophosphate extreme pressure additives include calcium sulfonate and / or magnesium sulfonate, and preferably calcium sulfonate.

[0055] High-alkalinity detergent additives are well known in the art and generally include alkali metal or alkaline earth metal high-alkalinity detergent additives. Such detergent additives are prepared by reacting a metal oxide or metal hydroxide with a matrix and carbon dioxide gas. The matrix is ​​typically an acid, for example, in the context of lubricants herein, an acid such as an aliphatic-substituted sulfonic acid. The term “high-alkalinity” refers to metal salts, such as metal salts of sulfonic acids used in the fluids herein, in which the amount of metal present exceeds the stoichiometric amount. Such salts can have conversion levels exceeding 100% (i.e., they can contain more than 100% of the theoretical amount of metal required to convert the acid to its “normal” or “neutral” salt). The expression “metal ratio” is commonly abbreviated as MR, which is used to represent the ratio of the total stoichiometric amount of metal in a high-alkalinity salt to the stoichiometric amount of metal in a neutral salt, based on known chemical reactivity and stoichiometry. In normal or neutral salts, the metal ratio is one, while in high-alkalinity salts, MR is greater than one. They are often referred to as highly basic, super-basic, or hyperbasic salts, and can be salts of organic sulfuric acid.

[0056] As used herein, in one embodiment, the highly alkaline detergent for the electric motor lubricating fluid of this document may have a total base number (TBN) of about 200 mg KOH / g or greater, about 290 mg KOH / g or greater, or about 300 mg KOH / g or greater. As used herein, the total base number or TBN is determined using ASTM D2896. When such detergent compositions are formed in an inert diluent (e.g., process oil, typically mineral oil), the total base number reflects the alkalinity of the overall composition, which includes the diluent and any other materials that may be present in the detergent composition (e.g., accelerators, etc.). The TBN of a highly alkaline detergent may be about 450 or less, or about 400 or less.

[0057] Preferably, the detergent described herein is a neutral, low-alkaline, or high-alkaline calcium sulfonate detergent, and wherein the detergent provides about 30 ppm to about 600 ppm of calcium (in other embodiments, about 30 ppm to about 300 ppm of calcium, about 30 ppm to about 100 ppm of calcium, or about 100 ppm or about 200 ppm of calcium). As mentioned above, the amount of calcium is a factor contributing relative to TBN, and then its contribution is balanced relative to anti-wear phosphorus and toluenetriazole nitrogen.

[0058] base oil :

[0059] The electric motor lubricating fluid described herein comprises one or more base oils having a lubricating viscosity. The base oil or base oil having a lubricating viscosity suitable for formulating the electric motor lubricating fluid for electric and / or hybrid electric motor vehicles according to this disclosure may be selected from any of suitable synthetic or natural oils or mixtures thereof having a suitable lubricating viscosity. Natural oils may include animal and vegetable oils (e.g., castor oil, lard) and mineral oils, such as liquid petroleum and solvent-treated or acid-treated alkanes, naphthenes, or mixed alkanes-naphthenes type mineral lubricants. Oils derived from coal or shale may also be suitable. Furthermore, oils derived from gas-to-liquid processes are also suitable. As measured by ASTM D2270-10, the base oil may have a kinematic viscosity of about 2 cSt to about 15 cSt at 100°C (e.g., kV100).

[0060] The base oils used in this invention may be a single base oil or a mixture of two or more base oils. One or more base oils may be selected from any base oil in Group III or IV as specified in the American Petroleum Institute (API) Base Oil Interchangeability Guide. These base oil classes are shown in Table 1 below:

[0061] Table 1

[0062]

[0063] In one embodiment, the base oil may be selected from API GII base oils, API Group III base oils, or API Group IV base oils, or mixtures of these base oils. Alternatively, the base oil may be two or more of API Group II base oils, two or more of API GIII base oils, or two or more of API Group IV base oils.

[0064] API Group III base oils may include oils derived from Fischer-Tropsch synthetic hydrocarbons. Fischer-Tropsch synthetic hydrocarbons are prepared from syngas containing H2 and CO using a Fischer-Tropsch catalyst. These hydrocarbons typically require further processing before use as base oils. These types of oils are commonly referred to as gas-to-liquid (GTL) oils. For example, the hydrocarbons can be hydroisomerized using the methods disclosed in U.S. Patent Nos. 6,103,099 or 6,180,575; hydrocracking and hydroisomerized using the methods disclosed in U.S. Patent Nos. 4,943,672 or 6,096,940; dewaxing using the methods disclosed in U.S. Patent No. 5,882,505; or hydroisomerized and dewaxing using the methods disclosed in U.S. Patent Nos. 6,013,171, 6,080,301; or 6,165,949.

[0065] API Group IV base oils, PAOs, are typically derived from monomers having 4 to 30, 4 to 20, or 6 to 16 carbon atoms. Examples of PAOs that can be used in this invention include those derived from octene, decene, mixtures thereof, etc. As measured by ASTM D2270-10, PAOs can have a kinematic viscosity of 2 to 15, 3 to 12, or 4 to 8 cSt at 100°C. Examples of PAOs include PAOs with a viscosity of 4 cSt at 100°C, PAOs with a viscosity of 6 cSt at 100°C, and mixtures thereof.

[0066] The base oil is combined with additive compositions as disclosed in the embodiments herein to provide lubricating and cooling fluids for use in electric motor systems having electric motors, gears, and clutches. Therefore, the base oil may be present in the lubricating and cooling fluids in an amount greater than about 80% by weight, based on the total weight of the lubricating and cooling fluids. In some embodiments, the base oil may be present in the lubricating and cooling fluids in an amount greater than about 85% by weight, based on the total weight of the lubricating and cooling fluids.

[0067] Other additives

[0068] In addition to the components described above, the electric motor lubricating fluid described herein may also contain other additives for transmission fluid composition types. Such additives include, but are not limited to, antioxidants, viscosity modifiers, phosphorus-containing components, detergents, corrosion inhibitors, rust inhibitors, defoamers, demulsifiers, pour point depressants, sealing and swelling agents, and additional dispersants, additional friction modifiers, and additional sulfur-containing components.

[0069] antioxidants In some embodiments, the lubricating fluid of the electric motor contains one or more antioxidants. Suitable antioxidants include phenolic antioxidants, aromatic amine antioxidants, sulfur-containing antioxidants, and organophosphites, etc.

[0070] Examples of phenolic antioxidants include 2,6-di-tert-butylphenol, liquid mixtures of tert-butylphenol, 2,6-di-tert-butyl-4-cresol, 4,4'-methylenebis(2,6-di-tert-butylphenol), 2,2'-methylenebis(4-methyl-6-tert-butylphenol), and mixtures of methylene-bridged polyalkylphenols and 4,4'-thiobis(2-methyl-6-tert-butylphenol), N,N'-di-sec-butylphenylenediamine, 4-isopropylaminodiphenylamine, benzene-α-naphthylamine, benzene-α-naphthylamine, and cycloalkylated diphenylamines. Examples include sterically hindered tert-butylated phenols, bisphenols, and cinnamic acid derivatives, and combinations thereof.

[0071] Aromatic amine antioxidants include, but are not limited to, diarylamines having the following formula:

[0072]

[0073] R' and R'' each independently represent a substituted or unsubstituted aryl group having 6 to 30 carbon atoms. Examples of substituents for aryl groups include aliphatic hydrocarbon groups such as alkyl, hydroxyl, halogen, carboxylic, ester, or nitro groups having 1 to 30 carbon atoms.

[0074] The aryl group is preferably a substituted or unsubstituted phenyl or naphthyl group, particularly wherein one or both of these aryl groups are substituted with at least one alkyl group having 4 to 30 carbon atoms, preferably 4 to 18 carbon atoms, and most preferably 4 to 9 carbon atoms. It is preferred that one or both aryl groups are substituted, for example, monoalkylated diphenylamine, dialkylated diphenylamine, or a mixture of monoalkylated diphenylamine and dialkylated diphenylamine.

[0075] Examples of diarylamines that may be used include, but are not limited to: diphenylamine; various alkylated diphenylamines, 3-hydroxydiphenylamine, N-phenyl-1,2-phenylenediamine, N-phenyl-1,4-phenylenediamine, monobutyldiphenylamine, dibutyldiphenylamine, monooctyldiphenylamine, dioctyldiphenylamine, monononyldiphenylamine, dinonyldiphenylamine, monotetradecyldiphenylamine, tetradecyldiphenylamine, benzene-α-naphthylamine, monooctylbenzene-α-naphthylamine, benzene-β-naphthylamine, monoheptyldiphenylamine, diheptyldiphenylamine, p-oriented styrylated diphenylamine, mixed butyloctyldiphenylamine and mixed octylstyryldiphenylamine.

[0076] Sulfur-containing antioxidants include, but are not limited to, sulfurized olefins, characterized by the type of olefin used in their production and the final sulfur content of the antioxidant. High molecular weight olefins (i.e., those with an average molecular weight of 168 g / mol to 351 g / mol) are preferred. Examples of olefins that can be used include α-olefins, isomerized α-olefins, branched olefins, cycloolefins, and combinations thereof.

[0077] α-olefins include, but are not limited to, any C4 to C5 olefins. 25 α-Alkenes. α-Alkenes can be isomerized before or during sulfidation. Structural and / or conformational isomers of α-alkenes containing internal double bonds and / or branches can also be used. For example, isobutene is a branched alkene counterpart of the α-alkene 1-butene.

[0078] Sulfur sources that can be used in olefin sulfidation reactions include elemental sulfur, sulfur monochloride, sulfur dichloride, sodium sulfide, sodium polysulfide, and mixtures thereof, either together or added at different stages of the sulfidation process.

[0079] Unsaturated oils, due to their unsaturation, can also be sulfurized and used as antioxidants. Examples of oils or fats that can be used include corn oil, canola oil, cottonseed oil, grapeseed oil, olive oil, palm oil, peanut oil, coconut oil, rapeseed oil, safflower oil, sesame oil, soybean oil, sunflower oil, tallow, and combinations thereof.

[0080] The total amount of antioxidant in the lubricating and cooling fluids described herein may be present in amounts of up to about 200 ppm of nitrogen, up to about 150 ppm of nitrogen, or about 100 ppm to about 150 ppm of nitrogen.

[0081] Friction modifier In some embodiments, the electric motor lubricating fluid includes additional friction modifiers besides those included in the friction modifier systems described above. Suitable additional 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, amides, nitriles, betaine, quaternary amines, imines, amine salts, aminoguanidines, enolamides, phosphonates, metal-containing compounds, glycerides, sulfurized aliphatic compounds and olefins, sunflower oil, other naturally occurring vegetable or animal oils, dicarboxylic acid esters, polyols and esters or metaesters of one or more aliphatic or aromatic carboxylic acids, etc.

[0082] Suitable friction modifiers may contain a hydrocarbon group selected from straight-chain, branched, or aromatic hydrocarbon groups or mixtures thereof, and such hydrocarbon groups may be saturated or unsaturated. The hydrocarbon group may consist of carbon and hydrogen or heteroatoms (such as sulfur or oxygen). The hydrocarbon group may have between 12 and 25 carbon atoms. In some embodiments, the friction modifier may be a long-chain fatty acid ester. In another embodiment, the long-chain fatty acid ester may be a monoester, diester, or (tri)glycerol ester. 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.

[0083] Other suitable friction modifiers may include organic, ashless (metal-free), nitrogen-free organic friction modifiers. Such friction modifiers may comprise esters formed by reacting carboxylic acids and anhydrides with alkanols, and typically contain polar terminal groups (e.g., carboxyl or hydroxyl groups) covalently bonded to a lipophilic hydrocarbon chain. Examples of organic ashless and nitrogen-free friction modifiers are generally known as glyceryl monooleate (GMO), which may contain monoesters, diesters, and trimers of oleic acid. Other suitable friction modifiers are described in U.S. Patent 6,723,685.

[0084] Amine-based friction modifiers may include amines or polyamines. These compounds may have straight-chain saturated or unsaturated hydrocarbon groups or mixtures thereof, and may contain 12 to 25 carbon atoms. Other examples of suitable friction modifiers include alkoxylated amines and alkoxylated ether amines. These compounds may have linear chains, saturated or unsaturated hydrocarbon groups, or mixtures thereof. They may contain about 12 to about 25 carbon atoms. Examples include ethoxylated amines and ethoxylated ether amines.

[0085] Amines and amides may be used as is or as additions or reaction products with boron compounds, such as boron oxide, boron halide, metaborates, boric acids or monoalkyl, dialkyl, or trialkyl esters of borate. Other suitable friction modifiers are described in U.S. Patent 6,300,291.

[0086] If the added friction modifier contains nitrogen, such added friction modifier can be present in the lubricating and cooling fluids in any amount, as long as it does not impair performance requirements.

[0087] Cleaning agents The metal cleaners that may be included in the electric motor lubricating fluids described herein typically comprise a polar head with a long, hydrophobic tail, wherein the polar head contains a metal salt of an acidic organic compound. The salts may contain substantially stoichiometric amounts of metal, in which case they are typically described as normal or neutral salts and generally have a total base number (TBN) of 0 to less than 150 (as measured by ASTM D2896). A significant amount of metal base can be included by reacting an excess of a metal compound (such as an oxide or hydroxide) with an acidic gas (such as carbon dioxide). The resulting highly alkaline cleaner comprises micelles of neutralizing cleaner surrounding an inorganic metal base (e.g., hydrated carbonate) core. Such highly alkaline cleaners can have a TBN of 150 or higher, such as 150 to 450 or higher.

[0088] Cleaning agents suitable for embodiments of the present invention include oil-soluble highly alkaline, low alkaline, and neutral sulfonates, phenolates, sulfurized phenolates, and salicylates of metals, particularly alkali metals or alkaline earth metals (e.g., sodium, potassium, lithium, calcium, and magnesium). More than one metal may be present, such as calcium and magnesium. Mixtures of calcium and / or magnesium with sodium are also suitable. Suitable metal cleaners may be highly alkaline calcium or magnesium sulfonates with a TBN of 150 to 450 TBN, highly alkaline calcium or magnesium phenolates or sulfurized phenolates with a TBN of 150 to 300 TBN, and highly alkaline calcium or magnesium salicylate with a TBN of 130 to 350 TBN. Mixtures of these salts may also be used.

[0089] Metal-containing cleaning agents can be present in lubricating and cooling fluids in an amount sufficient to improve the rust-preventive properties of the fluid. By total weight of the lubricating and cooling fluids, the metal-containing cleaning agent can be present in the fluid in an amount sufficient to provide up to 90 ppm of alkali metals and / or alkaline earth metals. In one example, the metal-containing cleaning agent can be present in an amount sufficient to provide about 20 ppm to about 50 ppm of alkali metals and / or alkaline earth metals. In another embodiment, the metal-containing cleaning agent can be present in an amount sufficient to provide about 30 ppm to about 40 ppm of alkali metals and / or alkaline earth metals.

[0090] In one method, the preferred cleaning agent may be a neutral to low-alkaline sulfonate, and in some methods, calcium sulfonate. Suitable cleaning agents may be calcium sulfonate having a TBN of 50 or less (e.g., about 25 to about 30) and providing the lubricant with no more than about 50 ppm of calcium. In other methods, the cleaning agent may provide about 25 ppm to about 40 ppm of calcium, about 30 ppm to about 40 ppm of calcium, or about 30 ppm to about 38 ppm of calcium to the finished electric motor lubricating fluid or composition. With regard to additive concentrates, the cleaning agent may provide the additive concentrate with more than about 950 ppm of calcium, or provide about 500 ppm to about 950 ppm of calcium, about 550 ppm to about 900 ppm of calcium, about 600 ppm to about 800 ppm of calcium, or about 600 ppm to about 700 ppm of calcium.

[0091] corrosion inhibitor Other rust inhibitors or corrosion inhibitors may also be included in the electric motor lubricating fluid described herein. Such materials include monocarboxylic acids and polycarboxylic acids. Examples of suitable monocarboxylic acids are octanoic acid, capric acid, and dodecanoic acid. Suitable polycarboxylic acids include dimer and trimer acids, such as those produced from tall oil fatty acids, oleic acid, linoleic acid, or their analogues.

[0092] Another useful type of rust inhibitor can be alkenyl succinic acid and alkenyl succinic anhydride corrosion inhibitors, such as, for example, tetrapropylene succinic acid, tetrapropylene succinic anhydride, tetradecenyl succinic acid, tetradecenyl succinic anhydride, hexadecenyl succinic acid, hexadecenyl succinic anhydride, etc. Also useful are half-esters of alkenyl succinic acid having 8 to 24 carbon atoms in the alkenyl group with alcohols (such as polyethylene glycol). Other suitable rust inhibitors or corrosion inhibitors include ether amines, acid phosphates, amines, polyethoxylated compounds such as ethoxylated amines, ethoxylated phenols and ethoxylated alcohols, imidazolines, aminosuccinic acid or derivatives thereof, etc. Mixtures of such rust inhibitors or corrosion inhibitors can be used. The total amount of corrosion inhibitor, when present in the lubricating composition described herein, can range from up to 2.0% by weight or from 0.01% by weight to 1.0% by weight, based on the total weight of the lubricating composition.

[0093] Viscosity modifierThe lubricating fluid for electric motors may optionally contain one or more viscosity modifiers. Suitable viscosity modifiers may include polyolefins, olefin copolymers, ethylene / propylene copolymers, polyisobutylene, hydrogenated styrene-isoprene polymers, styrene / maleate copolymers, hydrogenated styrene / butadiene copolymers, hydrogenated isoprene polymers, α-olefin maleic anhydride copolymers, polymethacrylates, polyacrylates, polyalkylstyrene, hydrogenated alkenylaryl conjugated diene copolymers, or mixtures thereof. Viscosity modifiers may include star polymers, and suitable examples are described in U.S. Publication 2012 / 0101017 A1.

[0094] In addition to viscosity modifiers or alternatives to viscosity modifiers, the electric motor lubricating fluids described herein may optionally contain one or more dispersant viscosity modifiers. Suitable dispersant viscosity modifiers may include functionalized polyolefins, such as ethylene-propylene copolymers functionalized with the reaction product of an acylation agent (such as maleic anhydride) and an amine; amine-functionalized polymethacrylates; or esterified maleic anhydride-styrene copolymers reacted with an amine.

[0095] The total amount of viscosity modifier and / or dispersant (if present) may be up to about 1.0% by weight, or up to about 0.5% by weight, or up to about 0.3% by weight, based on the total weight of the lubricating and cooling fluids.

[0096] Demulsifier Demulsifiers include trialkyl phosphates, and various polymers and copolymers of ethylene glycol, ethylene oxide, propylene oxide, or mixtures thereof, including polyethylene oxide, polypropylene oxide, and (ethylene oxide-propylene oxide) polymers. When present, the amount of demulsifier in the lubricating and cooling fluid may be up to about 0.05% by weight, up to about 0.02% by weight, or less than about 0.015% by weight, based on the total weight of the lubricating and cooling fluid.

[0097] Defoamer Defoamers used to reduce or prevent the formation of stable foams include siloxanes, polyacrylates, or organic polymers. Foam inhibitors that can be used in the compositions of the disclosed invention include copolymers of polysiloxanes, ethyl acrylates, and 2-ethylhexyl acrylate, and optionally vinyl acetate. When present, the amount of defoamer in the lubricating and cooling fluids can be up to about 0.1% by weight, up to about 0.05% by weight, or less than about 0.04% by weight, based on the total weight of the lubricating and cooling fluids.

[0098] Pour point depressantThe lubricating fluid for electric motors may optionally contain one or more pour point depressants. Suitable pour point depressants may include maleic anhydride-styrene esters, polymethyl methacrylates, polyacrylates, polyacrylic acid esters, or polyacrylamide, or mixtures thereof. Based on the total weight of the lubricant, the pour point depressant (if present) may be present in an amount from about 0.001% by weight to about 0.04% by weight.

[0099] Generally, the lubricating and cooling fluids described herein may include additive components within the range listed in Table 2.

[0100] Table 2

[0101]

[0102] The percentages for each component above represent the weight percentage of each component based on the total weight of the lubricating and cooling fluids containing said components. Additives used to formulate the compositions described herein can be blended into the base oil alone or in various sub-combinations. However, it may be suitable to simultaneously blend all components using additive concentrates (i.e., additives plus diluents, such as hydrocarbon solvents). The use of additive concentrates utilizes the compatibility offered by the combination of components in additive concentrate form. Furthermore, the use of concentrates reduces blending time and the possibility of blending errors.

[0103] The electric motor lubricating fluid described in this paper achieved a minimum FLS of 8 in the FZG A10 / 16.6R / 90 wear test under CEC L-84-02 and exhibited copper leaching of approximately 30 ppm or less when measured according to ASTM D130-19 (e.g., a semi-submerged copper strip heated to 150°C for 168 hours). Surprisingly, the fluid with low copper leaching performance described in this paper, consisting of a combination of toluenetriazole and an oil-soluble phosphorus extreme pressure additive, also achieved the aforementioned acceptable performance in the FZG A10 / 16.6R / 90 wear test under CEC L-84-02. Such performance is achieved when the detergent TBN is properly balanced relative to the anti-wear phosphorus and toluenetriazole nitrogen.

[0104] Unless the context of this discussion indicates otherwise, the following definitions of terms are provided to clarify the meaning of certain terms as used herein.

[0105] The terms “lubricating oil,” “lubricant composition,” “lubricating compound,” “lubricant,” and “lubricating and cooling fluid” refer to finished lubricating products comprising a major amount of a base oil and a minor amount of an additive composition. As used herein, the major amount includes at least 50% by weight or more, and the minor amount includes less than 50% by weight.

[0106] As used herein, the terms “additive package,” “additive concentrate,” and “additive composition” refer to a portion of a lubricating oil composition that does not include a major amount of base oil.

[0107] As used herein, the term "hydrocarbon substituent" or "hydrocarbon group" is used in its common sense, as is well known to those skilled in the art. Specifically, it refers to a group having a carbon atom directly connected to the rest of the molecule and having predominantly hydrocarbon characteristics. Each hydrocarbon group is independently selected from hydrocarbon substituents and hydrocarbon substituents containing one or more of a halogen group, hydroxyl group, alkoxy group, mercapto group, nitro group, nitroso group, amino group, pyridyl group, furanyl group, imidazolyl group, oxygen, and nitrogen, and wherein there are no more than two non-hydrocarbon substituents present for every ten carbon atoms in the hydrocarbon group.

[0108] As used herein, unless otherwise expressly stated, the terms “weight percentage” or “weight %” mean the percentage of the said component by weight of the whole composition.

[0109] As used herein, the terms “soluble,” “oil-soluble,” or “dispersible” may, but do not necessarily, mean that a compound or additive is soluble, miscible, or capable of being suspended in oil in all proportions. However, the foregoing terms do mean that they are, for example, soluble, suspended, dispersible, or stably dispersed in oil to a degree sufficient to exert their intended effect in an environment where oil is used. Furthermore, if desired, additional admixtures may be permitted at higher levels of specific additives.

[0110] As used herein, the term "alkyl" refers to a straight-chain, branched, cyclic, and / or substituted saturated chain moiety of about 1 to about 200 carbon atoms.

[0111] As used herein, the term "alkenyl" refers to a straight-chain, branched, cyclic, and / or substituted unsaturated chain portion of about 3 to about 30 carbon atoms.

[0112] As used herein, the term "aryl" refers to monocyclic and polycyclic aromatic compounds, which may include alkyl, alkenyl, alkylaryl, amino, hydroxyl, alkoxy, halogen substituents and / or heteroatoms including but not limited to nitrogen and oxygen.

[0113] As used herein, “number-average molecular weight” or “Mn” was determined by gel permeation chromatography (GPC) using commercially available polystyrene standards (where Mn was approximately 180 to approximately 18,000 as a calibration reference).

[0114] Total base number (TBN) is measured according to ASTM D2896.

[0115] It should be understood that throughout this disclosure, the terms “comprising,” “including,” “containing,” etc., are considered open-ended and include any element, step, or ingredient not expressly listed. The phrase “consisting substantially of…” means including any expressly listed element, step, or ingredient, as well as any additional element, step, or ingredient that does not substantially affect the basic and novel aspects of the invention. This disclosure also considers that any composition described using the terms “comprising,” “including,” or “containing” is also to be interpreted as including the disclosure of the same composition “consisting substantially of its specifically listed components” or “consisting of its specifically listed components.”

[0116] Example

[0117] The present disclosure and its many advantages can be better understood through the following examples. These examples are illustrative and do not limit its scope or spirit. Those skilled in the art will readily understand that variations of the components, methods, steps, and apparatus described in these examples can be used. All percentages, ratios, and parts mentioned in this disclosure are by weight, unless otherwise stated or apparent from the context of the following examples and the discussion throughout the disclosure. Any standardized test methods pointed to in the examples, disclosure, or claims, unless obvious from the context of their use, refer to a version of the test method publicly available at the time of filing of this disclosure.

[0118] The FZG friction resistance test is used to evaluate the friction load resistance of a lubricant and is performed according to the A10 / 16.6R / 90 test of CEC L-84-02. Results are reported as a destructive load level (FLS), with better results obtained for samples with higher FLS. Preferably, an FLS of 8 or higher is desired.

[0119] The leaching of copper into the lubricating composition was determined by ICP using a modified procedure according to ASTM D130-19 (using a semi-submerged copper strip heated to approximately 150°C and maintained for approximately 168 hours). Preferably, less than 30 ppm of copper was leached into the fluid after the test.

[0120] All embodiments and comparative examples of this invention contain varying amounts of phosphorus extreme pressure additives, detergents, and dispersants, as shown in the table for each embodiment. Each finished fluid contains the same base additive package containing the same antioxidants and defoamers. The antioxidants and defoamers are added to each fluid at the same processing rate. Slight variations in the process oil in the base package are used to account for variations in the processing rates of the phosphorus extreme pressure additives, detergents, and dispersants. In blends of the same base oils of Class II / III, the formulations of this invention and the comparative formulations are tested at their respective processing rates to obtain finished fluids with a kV100 of approximately 3.5 cSt. The formulations of this invention contain additives similar to those of the comparative formulations, but balance the delivery of phosphorus from the extreme pressure additives and nitrogen from the corrosion inhibitors, and are combined with selected sulfonate detergents to achieve surprisingly improved extreme pressure and corrosion performance in compositions that also contain toluenetriazole corrosion inhibitors. Details of these components are described below:

[0121] • Dispersant 1 (Disp-1) This is a phosphorylated and borated succinimide dispersant additive made from a mixture of polyisobutylene with a Mn of approximately 1000 and a PDI of less than 2.5, maleic anhydride, and a polyalkylene polyamine having an average of 6.5 nitrogen atoms per molecule. The dispersant is post-treated with phosphorous acid and boric acid. The dispersant contains approximately 0.8 wt% phosphorus, approximately 0.4 wt% boron, and approximately 1.8 wt% nitrogen.

[0122] • Dispersant 2 (Disp-2) This is a phosphorylated and borated succinimide dispersant additive obtained from a mixture of polyisobutylene with a Mn of approximately 2000 and a PDI of less than 3.0, maleic anhydride, and a polyalkylene polyamine having an average of 6.5 nitrogen atoms per molecule. The dispersant is post-treated with phosphorous acid and boric acid. The dispersant contains approximately 0.8 wt% nitrogen, approximately 0.2 wt% boron, and approximately 0.4 wt% phosphorus.

[0123] • Dispersant 3 (Disp-3) This is a succinimide dispersant additive obtained from a mixture of polyisobutylene with a Mn of approximately 1000 and a PDI of less than 2.5, maleic anhydride, and a polyalkylene polyamine having an average of 6.5 nitrogen atoms per molecule. The dispersant contains approximately 2.1% nitrogen by weight. No post-treatment with end-capping agents is required for the dispersant.

[0124] • Phosphorus EP Additive 1 (EP-1) Ash-free dialkyl dithiophosphate additive containing at least 3-[[bis(2-methylpropoxy)thiophosphono]thio]-2-methylpropionic acid having about 9.5% by weight of phosphorus and 19.5% by weight of sulfur.

[0125] • Detergent Additive 1 (Det-1)A highly alkaline calcium sulfonate detergent with approximately 300 TBN (as measured by ASTM D2896) and approximately 11.9% by weight of calcium.

[0126] • Detergent Additive 2 (Det-2) A low-alkaline to neutral calcium sulfonate detergent with approximately 28 TBN (as measured by ASTM D2896) and approximately 2.7% by weight of calcium.

[0127] • Detergent Additive 3 (Det-3) Phenolic calcium detergent with approximately 250 TBN (as measured by ASTM D2896) and approximately 9.25% by weight calcium.

[0128] • Corrosion resist 1 (CI-1) Toluyltriazole additive containing approximately 31.5% nitrogen by weight.

[0129] • Corrosion resist 2 (CI-2) It can be used as Cuvan 313 ™ Commercially available, and mainly composed of N-((1H-1,2,4-triazol-1-yl)methyl)-2-ethyl-N-(2-ethylhexyl)hex-1-amine, and having 17.6% nitrogen.

[0130] • Corrosion resist 3 (CI-3) : Can be used as Irgamet 39 ™ Commercially available, and mainly composed of N,N-bis(2-ethylhexyl)-aryl-methyl-1H-benzotriazole-1-carboxamide, and having 14.5% nitrogen.

[0131] Comparative Examples 1-4

[0132] Comparative Examples 1 and 2 are electric motor lubricating fluids prepared without a corrosion inhibitor. While the compositions of Comparative Examples 1 and 2 achieved acceptable FZG wear performance, they exhibited poor copper leaching performance. Comparative Example 3 is an electric motor lubricating fluid prepared similar to Comparative Example 1, but with the addition of a toluenetriazole corrosion inhibitor (CI-1). While this composition showed improved copper leaching performance, its FZG wear performance was compromised. Comparative Example 4 is an electric motor lubricating fluid prepared similar to Comparative Example 3, but with a higher extreme pressure additive treatment rate. However, as this fluid demonstrates, when used in combination with the toluenetriazole corrosion inhibitor, even doubling the extreme pressure additive treatment rate did not provide acceptable FZG wear performance. The fluid compositions are summarized in Table 3, elemental calculations are provided in Table 4, and results are provided in Table 5.

[0133] Table 3: Comparative Fluid Compositions

[0134]

[0135] Table 4: Elemental Analysis of Fluids (Calculated)

[0136]

[0137] The ratio [(EP P) + (CI N)] / TBN factor is calculated by adding the total phosphorus (in ppm) from EP-1 and the total nitrogen (in ppm) provided by CI-1, and then dividing by the detergent's TBN factor. For Comparative Example 3, the ratio is (57 + 31.5) / 0.001143

[0138] Table 5: Fluid performance (Results that do not pass are underlined)

[0139]

[0140] CEC L-84-022 (A10 / 16.6R / 90)

[0141] Modified procedure of ASTM D130-19 (half-immersed copper strip heated to 150°C for 168 hours)

[0142] Embodiments 1-8 of the present invention

[0143] Examples 1-8 of this invention comprise selected amounts of highly alkaline calcium sulfonate detergents or low-alkaline to neutral calcium sulfonate detergents (e.g., Det-1 or Det-2), which surprisingly contribute to the effective performance of toluenetriazole resist and oil-soluble phosphorus extreme pressure additives in achieving acceptable copper leaching performance and FZG wear resistance. Fluid compositions are provided in Table 6, elemental calculations are provided in Table 7, and test results are provided in Table 8. All examples of this invention are low-sulfur formulations containing less than 300 ppm sulfur.

[0144] Table 6: Fluid Compositions of the Invention

[0145]

[0146] Table 7: Elemental Analysis of Fluids (Calculated)

[0147]

[0148] The ratio [(EP P) + (CI N)] / TBN factor is calculated by adding the total phosphorus (in ppm) from EP-1 and the total nitrogen (in ppm) provided by CI-1, and then dividing by the detergent's TBN factor. For Example 1 of the present invention, the ratio is (57 + 31.5) / 0.002581.

[0149] Table 8: Fluid Properties

[0150]

[0151] CEC L-84-022 (A10 / 16.6R / 90)

[0152] Modified procedure of ASTM D130-19 (half-immersed copper strip heated to 150°C for 168 hours)

[0153] Comparative Examples 5-10

[0154] Comparative Example 5 is similar to Example 1 of the present invention, but with increased amounts of EP-1 and Det-1 additives. As can be seen in the test results in Table 11, this example illustrates that even with a high processing rate of Det-1, too much EP-1 has an adverse effect on copper leaching. Comparative Example 6 is similar to Comparative Example 3, but with an increased amount of Det-2, and illustrates that increasing the TBN contribution from the low-alkaline to neutral calcium sulfonate detergent Det-2 while maintaining a high processing rate of CI-1 is not conducive to achieving acceptable copper leaching performance and effective FZG wear performance. Comparative Example 7 illustrates that calcium phenolate Det-3 is not conducive to achieving acceptable copper leaching performance and effective FZG wear performance. Comparative Example 8 illustrates that the uncapped dispersant (Disp-3) is also ineffective in achieving the desired performance. Finally, Comparative Examples 9 and 10 are similar to Example 1 of the present invention, but include different resists. As can be seen in the test results, these combinations of additives do not achieve the desired performance, with unsuccessful results underlined.

[0155] Table 9: Comparative Fluid Compositions 5-10

[0156]

[0157] Table 10: Elemental Analysis of Fluids (Calculated)

[0158]

[0159] The ratio [(EP P) + (CI N)] / TBN factor is calculated by adding the total phosphorus (in ppm) from EP-1 and the total nitrogen (in ppm) provided by CI-1, and then dividing by the detergent's TBN factor. For Comparative Example 5, this ratio is (285 + 31.5) / 0.002581.

[0160] Table 11: Fluid Properties

[0161]

[0162] CEC L-84-022 (A10 / 16.6R / 90)

[0163] Modified procedure of ASTM D130-19 (half-immersed copper strip heated to 150°C for 168 hours)

[0164] Figure 1 The illustration shows an embodiment in which a detergent TBN is properly balanced relative to anti-abrasion phosphorus and toluenetriazole nitrogen in a fluid composition that also includes a capped succinimide dispersant. Figure 1 As shown, a ratio of approximately 70,000 or less of [(EP phosphorus) + (CI nitrogen)] / TBN factor achieves an FZG destructive load level of 8 or higher and copper leaching of 30 ppm or less. Figure 1 This includes data from Tables 4-5, 7-8, and 10-11.

[0165] It should be understood that although the lubricating compositions and formulations of this disclosure have been described in conjunction with their detailed description and summary herein, the foregoing description is intended to be illustrative and not limiting of the scope of this disclosure, which is defined by the scope of the appended claims. Other aspects, advantages, and modifications are also within the scope of the claims. This specification and the examples are intended to be illustrative only, wherein the true scope of this disclosure is indicated by the appended claims.

[0166] Other embodiments of this disclosure will be apparent to those skilled in the art upon consideration of this specification and the practices of the embodiments disclosed herein. As used throughout the specification and claims, “a / an” and / or “a / an” may refer to one or more. Unless otherwise indicated, all figures expressing quantities of components and properties, such as molecular weight, percentage, ratio, reaction conditions, etc., used in this specification should be understood to be modified in all cases by the term “about,” regardless of whether the term “about” is present. Therefore, unless indicated to the contrary, the numerical parameters set forth in this specification are approximations that may vary depending on the desired properties sought to be obtained through this disclosure. To a minimum, and without attempting to limit the application of the equivalence principle to the scope of the claims, each numerical parameter should be interpreted at least according to the number of significant figures reported and by applying general rounding techniques. Although the numerical ranges and parameters set forth in the broad scope of this disclosure are approximations, the values ​​set forth in particular embodiments are reported as precisely as possible. However, any numerical value inherently contains some error necessarily caused by the standard deviation found in its corresponding test measurement.

[0167] It should be understood that each component, compound, substituent or parameter disclosed herein should be interpreted as disclosed for use alone or in combination with one or more of each other component, compound, substituent or parameter disclosed herein.

[0168] It should also be understood that each range disclosed herein should be interpreted as a disclosure of each specific value within the disclosed range having the same significant digits. Thus, the range 1-4 will be interpreted as an explicit disclosure of the values ​​1, 2, 3, and 4, as well as any range of these values, such as 1-4, 1-3, 1-2, 2-4, 2-3, etc.

[0169] It should also be understood that each lower limit of each range disclosed herein should be interpreted as a combination of each upper limit of each range and each specific value within each range disclosed herein for the same component, compound, substituent, or parameter. Therefore, this disclosure should be interpreted as a disclosure of all ranges derived by combining each lower limit of each range with each upper limit of each range or with each specific value within each range, or by combining each upper limit of each range with each specific value within each range.

[0170] Furthermore, the specific amounts / values ​​of components, compounds, substituents, or parameters disclosed in this specification or examples should be interpreted as disclosures of a lower or upper limit of a range, and therefore can be combined with any other lower or upper limit or specific amount / value of the range of the same components, compounds, substituents, or parameters disclosed elsewhere in this disclosure to form such a range of components, compounds, substituents, or parameters.

Claims

1. A lubricating fluid for an electric motor in an electric or hybrid electric vehicle, the electric motor lubricating fluid comprising: One or more base oils having a lubricating viscosity; At least about 1 ppm of nitrogen provided by toluenetriazole resist; An oil-soluble phosphorus anti-wear additive, comprising ashless dialkyl dithiophosphate, provides the electric motor lubricating fluid with about 40 ppm to 150 ppm of phosphorus and about 85 ppm to about 315 ppm of sulfur. Succinimide dispersant, said succinimide dispersant being derived from a hydrocarbon-substituted dicarboxylic acid or anhydride that reacts with a polyalkylene polyamine having one or more primary or secondary amines, wherein said one or more primary or secondary amines are post-treated with an end-capping agent. A sulfonate detergent, wherein the amount of the sulfonate detergent contributes approximately 0.02 to approximately 1.9 TBN (ASTM D2896) to the lubricating fluid of the electric motor; and The electric motor lubricating fluid contains less than about 500 ppm of sulfur and at least about 70 ppm of phosphorus.

2. The electric motor lubricating fluid according to claim 1, wherein the toluenetriazole corrosion inhibitor comprises methyl-1H-benzotriazole.

3. The electric motor lubricating fluid of claim 1, wherein the ratio of the amount of phosphorus (ppm) delivered to the fluid from the ashless dialkyl dithiophosphoric acid to the amount of nitrogen (ppm) (EPPhos+CI nitrogen) delivered to the fluid from the toluenetriazole resist to the TBN factor is about 70,000 or less, and wherein the TBN factor is the TBN (ASTM D2896) delivered to the fluid by the amount of metal (ppm) delivered to the fluid by the detergent (TBN / Det metal).

4. The electric motor lubricating fluid of claim 3, wherein the sulfonate detergent is calcium sulfonate, and the electric motor lubricating fluid is supplied with about 30 ppm to about 600 ppm of calcium.

5. The electric motor lubricating fluid according to claim 1, wherein the oil-soluble phosphorus anti-wear additive comprising the ashless dialkyl dithiophosphate is prepared by a method comprising the steps of: (a) reacting an organic hydroxyl compound with phosphorus pentasulfide to form a reaction product, and (b) further reacting the reaction product with an unsaturated carboxylic acid to form the oil-soluble phosphorus anti-wear additive comprising the ashless dialkyl dithiophosphate; and / or wherein the ashless dialkyl dithiophosphate comprises a compound of formula I or a salt thereof: (Form IIa) R4 and R5 are independently C1 to C1. 10 A straight-chain or branched alkyl group, and R6 is -H or -CH3; and / or said ashless dialkyl dithiophosphate comprises 3-[[bis(2-methylpropoxy)thiophosphines]thio]-2-methylpropionic acid.

6. The electric motor lubricating fluid of claim 1, wherein the succinimide dispersant is post-treated with a phosphorus-containing compound and / or a boron-containing compound; and / or wherein the succinimide dispersant delivers about 20 ppm to about 100 ppm of phosphorus and about 5 ppm to about 50 ppm of boron to the electric motor lubricating fluid.

7. The electric motor lubricating fluid of claim 1, wherein the sulfonate detergent is provided in an amount contributing about 0.2 to about 0.6 TBN; and / or wherein the electric motor lubricating fluid exhibits copper leaching of about 30 ppm or less according to ASTM D130; and / or wherein the electric motor lubricating fluid has a destructive load class of 8 or higher in the FZG A10 / 16.6R / 120 test of ASTM D5182; and / or wherein the electric motor lubricating fluid contains less than about 300 ppm of sulfur.

8. A method for lubricating a power transmission system component including an electric motor, the method comprising: The power transmission system components are lubricated with an electric motor lubricating fluid, wherein the electric motor lubricating fluid contacts a portion of the electric motor; In the electric motor, the lubricating fluid comprises (i) one or more base oils having a lubricating viscosity; (ii) at least about 1 ppm of nitrogen provided by a toluenetriazole corrosion inhibitor; (iii) an oil-soluble phosphorus anti-wear additive comprising ashless dialkyl dithiophosphate, providing the electric motor lubricating fluid with about 40 ppm to about 150 ppm of phosphorus and about 85 ppm to about 315 ppm of sulfur; (iv) a succinimide dispersant derived from a hydrocarbon-substituted dicarboxylic acid or anhydride reacting with a polyalkylene polyamine having one or more primary or secondary amines, wherein the one or more primary or secondary amines are post-treated with an end-capping agent; (v) a sulfonate detergent provided in an amount contributing about 0.02 to about 1.9 TBN to the electric motor lubricating fluid; and (vi) wherein the electric motor lubricating fluid contains less than about 500 ppm of sulfur and at least about 70 ppm of phosphorus; and The electric motor lubricating fluid described therein exhibits copper leaching of approximately 30 ppm or less according to ASTM D130 and has a destructive load rating of 8 or higher in the FZG A10 / 16.6R / 120 test of ASTM D5182.

9. The method of claim 8, wherein the triazole resist comprises methylbenzotriazole.

10. The method of claim 8, wherein the ratio of the amount (ppm) of phosphorus delivered from the ashless dialkyl dithiophosphoric acid to the amount (ppm) of nitrogen delivered from the toluenetriazole resist to the fluid (EP Phos + CI nitrogen) relative to the TBN factor is about 70,000 or less, and wherein the TBN factor is the TBN (ASTM D2896) delivered to the fluid by the detergent divided by the amount (ppm) of metal delivered to the fluid by the detergent (TBN / Det metal); and / or wherein the sulfonate detergent is calcium sulfonate, and provides about 30 ppm to about 600 ppm of calcium to the electric motor lubricating fluid.

11. The method of claim 8, wherein the oil-soluble phosphorus anti-wear additive of the ashless dialkyl dithiophosphate is prepared by a method comprising the steps of: (a) reacting an organic hydroxy compound with phosphorus pentasulfide to form a reaction product, and (b) further reacting the reaction product with an unsaturated carboxylic acid to form the oil-soluble phosphorus anti-wear additive comprising the ashless dialkyl dithiophosphate.

12. The method of claim 8, wherein the ashless dialkyl dithiophosphate comprises a compound of formula I or a salt thereof: (Form IIa) R4 and R5 are independently C1 to C1. 10 A straight-chain or branched alkyl group, and R6 is -H or -CH3; and / or said ashless dialkyl dithiophosphate comprises 3-[[bis(2-methylpropoxy)thiophosphines]thio]-2-methylpropionic acid.

13. The method of claim 8, wherein the succinimide dispersant is post-treated with a phosphorus-containing compound and / or a boron-containing compound; and / or wherein the succinimide dispersant delivers about 20 ppm to about 100 ppm of phosphorus and about 5 ppm to about 50 ppm of boron to the electric motor lubricating fluid.

14. The method of claim 8, wherein the sulfonate detergent is provided in an amount contributing about 0.2 to about 1.6 TBN.

15. The method of claim 8, wherein the electric motor lubricating fluid contains less than about 300 ppm of sulfur.

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