Alkoxylated alcohols for increasing the breakdown voltage of lubricants.

Abstract

The present invention relates to a lubricant comprising a base stock selected from hydrocarbons, 50 to 1000 ppm of water, and an alkoxylated alcohol, wherein the alcohol is selected from the group consisting of C4-C 20 The invention also relates to a method for lubricating a mechanical device of an electric vehicle comprising contacting the lubricant with the mechanical device, the use of the alkoxylated alcohol to increase the breakdown voltage of a lubricant having a base stock selected from hydrocarbons, and the use of the alkoxylated alcohol in a lubricant having a base stock selected from hydrocarbons to reduce electrical discharge machining.

Description

[Technical field]

[0001] The present invention relates to a lubricant comprising a base stock selected from hydrocarbons, 50 to 1000 ppm of water, and an alkoxylated alcohol, wherein the alcohol is selected from the group consisting of C4-C 20 The invention also relates to a method for lubricating a mechanical device of an electric vehicle comprising the step of contacting the lubricant with the mechanical device, the use of an alkoxylated alcohol to increase the breakdown voltage of a lubricant comprising a base stock selected from a hydrocarbon, and the use of an alkoxylated alcohol in a lubricant comprising a base stock selected from a hydrocarbon to reduce electrical discharge machining, and a lubricant comprising a base stock selected from a hydrocarbon selected from API Group I, II, or III base stocks, 50 to 1000 ppm water, and an alkoxylated alcohol, wherein the alcohol is selected from a C4-C 20 alkoxylated with a hydrophobic epoxide selected from the group consisting of epoxides, and the alcohol is selected from the group consisting of C2-C 12 The diol is selected from the group consisting of polyethylene glycol, polypropylene glycol and polytetrahydrofuran. [Background technology]

[0002] Unintended electrical currents (sometimes called parasitic currents) flowing through rolling bearings can cause damage to machine components and lubricants. Typically, bearing current phenomena are in the form of arcing current pulses caused by capacitive discharge breakdown of the lubricant. Such phenomena are also known as electrical discharge machining (EDM). The result is either lubricant burning or bearing wear.

[0003] In the automotive industry, frequency inverters are used to control variable speed inverter fed electric motors and generators, which can cause damage to rolling bearings as a result of bearing currents.Typical events include damage caused by electrical currents, cratering of the bearing raceways, fluting across the bearing raceways, and oxidation of the lubricant in the contact areas between the rolling elements and the raceways.

[0004] To avoid these problems, the bearing or rotating shaft design has been optimized:

[0005] WO 2022 / 005935 proposed a grounding brush assembly for mitigating currents in a rotating shaft in the presence of viscous media.

[0006] In WO 2013 / 090997 an earth assembly for an electric motor was proposed.

[0007] US 2004 / 0056543 A1 proposed an electromechanical device in which a voltage reduction member is fixed to a rotatable member.

[0008] The effect of lubricants on parasitic currents was also investigated:

[0009] Bechev et al. “Characterization of electrical lubricant properties for modelling of electrical drive systems with rolling bearings” Bearing World Journal, 2018 (3) 93-106 investigated electrical lubricant properties related to parasitic bearing currents.

[0010] Gonda et al. “The Influence of Lubricant Conductivity on Bearing Currents in the Case of Rolling Bearing Greases” Lubricants, 2019(7), 108-121 investigated harmful electrical currents in rolling bearings. Summary of the Invention [Problem to be solved by the invention]

[0011] The object of the present invention was to provide a lubricant which overcomes the above problems. [Means for solving the problem]

[0012] The object is solved by a method for lubricating a mechanical device of an electric vehicle, comprising the step of contacting the mechanical device with a lubricant, wherein the lubricant comprises: a base stock selected from hydrocarbons; -50 to 1000 ppm water, -C4-C 20 and an alkoxylated alcohol that is alkoxylated with a hydrophobic epoxide selected from the group consisting of epoxides.

[0013] The purpose is to a base stock selected from hydrocarbons; -100~1000ppm water, -C4-C 20 and an alkoxylated alcohol which has been alkoxylated with a hydrophobic epoxide selected from epoxides.

[0014] The purpose is to a base stock selected from hydrocarbons selected from API Group I, II, or III base stocks; -50 to 1000 ppm water, -C4-C 20alkoxylated with a hydrophobic epoxide selected from epoxides, C2-C 12 and an alkoxylated alcohol, which is a diol selected from the group consisting of polyethylene glycol, polypropylene glycol, and polytetrahydrofuran. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] A lubricant is usually a substance capable of reducing friction between surfaces (preferably metal surfaces), such as the surfaces of a mechanical device. A mechanical device may be a mechanism consisting of a device that operates on a mechanical principle. A lubricant is usually a lubricating fluid, a lubricating oil, or a lubricating grease.

[0016] Lubricants include light, medium and heavy duty engine oils, industrial engine oils, marine engine oils, automotive engine oils, crankshaft oils, compressor oils, refrigeration oils, hydrocarbon compressor oils, ultra-low temperature lubricants, high temperature lubricants, wire rope lubricants, textile machine oils, refrigeration oils, aviation and aerospace lubricants, aviation turbine oils, transmission oils, gas turbine oils, spindle oils, spin oils, traction fluids, fluid), transmission oil, plastic transmission oil, passenger car transmission oil, truck transmission oil, industrial transmission oil, industrial gear oil, insulating oil, gauge oil, brake oil, transmission oil, shock absorber oil, heat dispersion medium oil, transformer oil, grease, chain oil, minimum quantity lubricant for metalworking operations, oil for warm and cold working, oil for water-based metalworking fluids, oil for neat oil metalworking fluids, oil for semi-synthetic metalworking fluids, oil for synthetic metalworking fluids, drilling detergent for soil exploration, hydraulic oil, biodegradable lubricant or lubricating grease or wax, oil for chainsaws, mold release agent, molding fluid, lubricant for guns, pistols, rifles or watch lubricant, and food grade approved lubricant.

[0017] The lubricants typically comprise at least 50, 60, 70, 80, or 90% by weight of the base stock. The lubricants typically comprise up to 80, 90, 95, or 99% by weight of the base stock. The lubricants typically comprise 50-99, 50-95, 60-90, or 70-80% by weight of the base stock.

[0018] The base stock is selected from hydrocarbons. Suitable hydrocarbons are usually mixtures of higher alkanes from mineral sources (e.g. mineral oils), especially from petroleum distillates, or from synthetic sources (e.g. polyalphaolefins or GTL oils). Hydrocarbons can be naphthenic, paraffinic, or aromatic in chemical structure. In industrial applications, base stocks usually include a chemical composition that contains all three oils (paraffinic, naphthenic, and aromatic) in certain proportions.

[0019] Naphthenic hydrocarbons consist of methylene groups arranged in a ring formation with paraffinic side chains attached to the ring. The pour points are generally lower than those of paraffinic oils.

[0020] Paraffinic hydrocarbons include saturated, straight or branched chain hydrocarbons. High molecular weight straight chain paraffins increase the pour point of the oil and are often removed by dewaxing.

[0021] Aromatic hydrocarbons are semi-unsaturated, closed carbon ring hydrocarbons that may have side chains attached. These oils are more susceptible to degradation than paraffinic and naphthenic oils, producing corrosive by-products.

[0022] In another form, hydrocarbons can be GTL (gas to liquid) oils, synthesized using the Fischer-Tropsch process to convert natural gas into liquid fuels. GTL oils can be produced as follows: in the first stage, synthesis gas (a mixture of hydrogen and carbon monoxide) is produced from natural gas by partial oxidation. In the second stage, the synthesis gas is converted into liquid hydrocarbons using a catalyst. The final stage is cracking and isomerization, which "tunes" the molecular chains into products with desired properties. These GTL oils correspond to API Group 3 base oils, Shell XHVI being an example of a commercial product.

[0023] Preferably, the hydrocarbons are selected from API Group I, II, III or IV base stocks, or mixtures thereof. In particular, the hydrocarbons are selected from API Group I, II or III base stocks, or mixtures thereof. In another particular embodiment, the hydrocarbons are selected from API Group III base stocks.

[0024] A definition of base stocks can be found in the American Petroleum Institute (API) publication "Engine Oil Licensing and Certification System", Industry Services Department, Fourteenth Edition, December 1996, Addendum 1, December 1998. Said publication classifies base oils as follows: a) Group I base oils contain less than 90% saturates (ASTM D2007) and / or more than 0.03% sulfur (ASTM D2622) and have a viscosity index greater than or equal to 80 and less than 120 (ASTM D2270). b) Group II base oils contain greater than or equal to 90 percent saturates and less than or equal to 0.03 percent sulfur and have a viscosity index greater than or equal to 80 and less than 120. c) Group III base oils contain greater than or equal to 90 percent saturates and less than or equal to 0.03 percent sulfur and have a viscosity index greater than or equal to 120. d) Group IV base oils include polyalphaolefins. Polyalphaolefins (PAOs) include known PAO materials that typically include relatively low molecular weight hydrogenated polymers or oligomers of alpha olefins, including but not limited to C2 to C32 alpha olefins, with C8 to about C16 alpha olefins, such as 1-octene, 1-decene, 1-dodecene, and the like, being preferred. Preferred polyalphaolefins are poly-1-octene, poly-1-decene, and poly-1-dodecene. e) Group V base oils include any base oil not listed in Groups I to IV. Examples of Group V base oils include alkyl naphthalenes, alkylene oxide polymers, silicone oils, and phosphate esters.

[0025] The lubricant is typically free of API Group V base stocks. In another embodiment, the lubricant contains up to 20, 10, 5, or 1 weight percent of an API Group V base stock.

[0026] In another embodiment, the lubricant is typically free of API Group IV and V base stocks. In another embodiment, the lubricant contains up to 20, 10, 5, or 1 weight percent of API Group IV and V base stocks.

[0027] Base stocks typically have a breakdown voltage of up to 1000, 500, 250, 150 or 100 volts. Base stocks typically have a breakdown voltage of at least 1, 3, 5, 10 or 20 volts. Base stocks typically have a breakdown voltage in the range of 1 to 1000 volts, or 5 to 500 volts, or 10 to 150 volts. The breakdown voltage of the base stock is typically determined at a water concentration of less than 5 ppm, especially 0 ppm.

[0028] The breakdown voltage of the base stock can be determined in accordance with DIN EN 60156 (“Insulating liquids - Determination of the breakdown voltage at power frequency - Test method”) prior to use in the lubricant.

[0029] The lubricant contains water in an amount of 50 to 1000 ppm, or 100 to 1000 ppm, or 150 to 900 ppm, or 200 to 800 ppm, or 200 to 600 ppm.

[0030] The water content can be determined by the Karl Fischer method (DIN 51777 / 1 / ASTM D1744). The water content can be determined at 20°C.

[0031] Water is normally present in dissolved form in the lubricant.

[0032] Moisture in the lubricant can come from traces of moisture in the base stock, lubricant additives, or alkoxylated alcohols, or from moisture in the air.

[0033] The moisture content in the lubricant can be adjusted, for example, using a desiccant breather, which can be attached to the equipment (e.g., oil reservoir, oil drum). When moist air passes through the desiccant breather, the moisture in the air is then absorbed by a moisture absorbent (e.g., a silica gel layer). The moisture content in the lubricant can be adjusted by subjecting the lubricant to a vacuum or by excluding the air or moisture before or during mixing of the lubricant's components.

[0034] The lubricant comprises an alkoxylated alcohol, where the alcohol is a C4-C 20 The alkoxylated epoxide is selected from the group consisting of hydrophobic epoxides.

[0035] The alcohol can be a monoalcohol, a diol, or a polyol having three or more hydroxy groups.

[0036] In one form, the alcohol is a straight or branched C1-C 22 Alkanol or C4-C 18 Alkanols, which may be straight or branched chain, C1-C 22 The monoalcohol is selected from the group consisting of methanol, ethanol, propanol, butanol, pentanol, hexanol, neopentanol, isobutanol, decanol, 2-ethylhexanol, and higher acyclic alcohols having 11 to 22 carbon atoms that can be obtained from both natural and petrochemical sources.

[0037] In another embodiment, the alcohol is a C2-C 12 The diol is selected from diols (e.g., C2-C8 alkanediols or C2-C8 alkanediols), polyethylene glycols, polypropylene glycols and polytetrahydrofurans. Preferably, the alcohol is a C2-C 12 C2-C 12 Examples of diols are monoethylene glycol, monopropylene glycol, butylene glycol, diethylene glycol or dipropylene glycol. In another embodiment, the alcohol is polytetrahydrofuran, which may have 2-30, 3-20, 5-20 or 6-16 repeat units. In another embodiment, the alcohol is polyethylene glycol or polypropylene glycol, which may have 2-30, 3-20, 5-20 or 6-16 repeat units. In particular, the alcohol is a C2-C 12 The diol is selected from the group consisting of polyethylene glycol, polypropylene glycol and polytetrahydrofuran.

[0038] In another embodiment, the alcohol is a C3-C glycerol such as neopentyl glycol, trimethylolpropane, and pentaerythritol. 12 The polyol is a polyol having three or more hydroxy groups selected from the group consisting of polyols.

[0039] The alcohol is preferably a C1-C 22 Monoalcohols, C2-C 12 Diol, polytetrahydrofuran, or C3-C 12 It is a polyol.

[0040] In another preferred embodiment, the alcohol is a C1-C 22 It is an alkanol, a C2-C8 alkanediol, or a polytetrahydrofuran having 3 to 20 repeating units.

[0041] In another preferred embodiment, the alcohol is a C4-C 18 It is an alkanol, a C2-C6 alkanediol, or a polytetrahydrofuran having 5 to 20 repeating units.

[0042] Hydrophobic epoxides are C4-C 20 Epoxides, preferably C4-C 12 Epoxides, for example, selected from butylene oxide, pentylene oxide, hexylene oxide, heptylene oxide, 1,2-epoxyoctane, 1,2-epoxynonane, 1,2-epoxydecane, 1,2-epoxyundecane, 1,2-epoxydodecane (also called dodecyl oxide), 1,2-epoxytridecane, 1,2-epoxytetradecane, 1,2-epoxypentadecane, 1,2-epoxyhexadecane, 1,2-epoxyheptadecane, 1,2-epoxyoctadecane, or mixtures thereof.

[0043] Preferably, the hydrophobic epoxide is selected from butylene oxide, dodecyl oxide, or a mixture thereof.

[0044] In another preferred embodiment, the hydrophobic epoxide is selected from dodecyl oxide, In another preferred embodiment, the hydrophobic epoxide is selected from butylene oxide.

[0045] The alcohol can be alkoxylated with a hydrophobic epoxide and, optionally, further alkoxylated with propylene oxide.

[0046] Preferably, the alcohol is alkoxylated with a hydrophobic epoxide selected from butylene oxide and dodecyl oxide, and optionally further alkoxylated with propylene oxide.

[0047] In another preferred form, the alcohol is alkoxylated with a hydrophobic epoxide selected from butylene oxide and dodecyl oxide and further alkoxylated with propylene oxide.

[0048] In another preferred form, the alcohol is alkoxylated with a hydrophobic epoxide selected from butylene oxide and further alkoxylated with propylene oxide.

[0049] In another preferred form, the alcohol is alkoxylated with a hydrophobic epoxide selected from dodecyl oxide and further alkoxylated with propylene oxide.

[0050] In another preferred form, the alcohol is alkoxylated with a hydrophobic epoxide selected from butylene oxide and dodecyl oxide, and optionally further alkoxylated with propylene oxide, and the alcohol is a C1-C 22 Monoalcohols, C2-C 12 Diol, polytetrahydrofuran, or C3-C 12 It is a polyol.

[0051] In another preferred form, the alcohol is alkoxylated with a hydrophobic epoxide selected from butylene oxide and dodecyl oxide, and optionally further alkoxylated with propylene oxide, and the alcohol is a C2-C 12 The diol is selected from the group consisting of polyethylene glycol, polypropylene glycol and polytetrahydrofuran.

[0052] In another preferred embodiment, the alcohol is alkoxylated with a hydrophobic epoxide selected from butylene oxide and dodecyl oxide and further alkoxylated with propylene oxide, the alcohol being a C1-C 22 Monoalcohols, C2-C 12 Diol, polytetrahydrofuran, or C3-C 12 It is a polyol.

[0053] In another preferred embodiment, the alcohol is alkoxylated with a hydrophobic epoxide selected from butylene oxide and further alkoxylated with propylene oxide, the alcohol being a C1-C 22 Monoalcohols, C2-C 12 Diol, polytetrahydrofuran, or C3-C 12 It is a polyol.

[0054] In another preferred embodiment, the alcohol is alkoxylated with a hydrophobic epoxide selected from dodecyl oxide and further alkoxylated with propylene oxide, the alcohol being a C1-C 22 Monoalcohols, C2-C 12 Diol, polytetrahydrofuran, or C3-C 12 It is a polyol.

[0055] In another preferred embodiment, the alcohol is alkoxylated with a hydrophobic epoxide selected from dodecyl oxide and further alkoxylated with propylene oxide, the alcohol being a C2-C 12 The diol is selected from the group consisting of polyethylene glycol, polypropylene glycol, and polytetrahydrofuran.

[0056] Propylene oxide may be present in amounts up to 90, 80, 70, 65, 60, or 55 weight percent based on the total amount of hydrophobic epoxide and propylene oxide. Propylene oxide may be present in amounts up to 85, 75, 70, or 65 mole percent based on the total amount of hydrophobic epoxide and propylene oxide.

[0057] Preferably, the alcohol is alkoxylated with a hydrophobic epoxide selected from butylene oxide and dodecyl oxide, and optionally further alkoxylated with propylene oxide, which may be present up to 90, 80, 70, 65, 60, or 55 wt. %, based on the total amount of hydrophobic epoxide and propylene oxide.

[0058] In another preferred form, the alcohol is alkoxylated with a hydrophobic epoxide selected from butylene oxide and dodecyl oxide, and optionally further alkoxylated with propylene oxide, which may be present in an amount of up to 85, 75, 70, or 65 mole %, based on the total amount of hydrophobic epoxide and propylene oxide.

[0059] In another preferred form, the alcohol is alkoxylated with a hydrophobic epoxide selected from butylene oxide and dodecyl oxide and further alkoxylated with propylene oxide, the propylene oxide being present in an amount of up to 90, 80, 70, 65, 60, or 55 weight percent based on the total amount of hydrophobic epoxide and propylene oxide.

[0060] In another preferred form, the alcohol is alkoxylated with a hydrophobic epoxide selected from butylene oxide and dodecyl oxide, and further alkoxylated with propylene oxide, the propylene oxide being present in an amount of up to 85, 75, 70, or 65 mole %, based on the total amount of hydrophobic epoxide and propylene oxide.

[0061] In another preferred form, the alcohol is alkoxylated with a hydrophobic epoxide selected from butylene oxide and further alkoxylated with propylene oxide, the propylene oxide being present in an amount of up to 90, 80, 70, 65, 60, or 55 weight percent based on the total amount of hydrophobic epoxide and propylene oxide.

[0062] In another preferred form, the alcohol is alkoxylated with a hydrophobic epoxide selected from dodecyl oxide and further alkoxylated with propylene oxide, the propylene oxide being present in an amount of up to 85, 75, 70, or 65 mole %, based on the total amount of hydrophobic epoxide and propylene oxide.

[0063] In another preferred form, the alcohol is alkoxylated with a hydrophobic epoxide selected from dodecyl oxide and further alkoxylated with propylene oxide, the propylene oxide being present in an amount of up to 85, 75, 70, or 65 mole %, based on the total amount of hydrophobic epoxide and propylene oxide.

[0064] In one form of alkoxylated alcohol, the alcohol is alkoxylated with a hydrophobic epoxide selected from butylene oxide and further alkoxylated with propylene oxide, C1-C 22 It is an alkanol.

[0065] In another form of alkoxylated alcohol, the alcohol is alkoxylated with a hydrophobic epoxide selected from butylene oxide and further alkoxylated with propylene oxide, C6-C 18 The weight ratio of butylene oxide to propylene oxide is 4:1 to 1:4, preferably 2:1 to 1:2.

[0066] In another form of alkoxylated alcohol, the alcohol is alkoxylated with a hydrophobic epoxide selected from butylene oxide and further alkoxylated with propylene oxide, C8-C 14 It is an alkanol, the weight ratio of butylene oxide to propylene oxide is 4:1 to 1:4, preferably 2:1 to 1:2, and the molecular weight of the alkoxylated alcohol is 300 to 5000 g / mol.

[0067] In another form of alkoxylated alcohol, the alcohol is alkoxylated with a hydrophobic epoxide selected from butylene oxide and further alkoxylated with propylene oxide. 12 It is an alkanol, the weight ratio of butylene oxide to propylene oxide is 3:1 to 1:3, preferably 1.5:1 to 1:1.5, and the molecular weight of the alkoxylated alcohol is 500 to 3000 g / mol.

[0068] In one form of the alkoxylated alcohol, the alcohol is a C2-C8 alkanediol that is alkoxylated with a hydrophobic epoxide selected from butylene oxide.

[0069] In another form of the alkoxylated alcohol, the alcohol is a C2-C4 alkanediol that is alkoxylated with a hydrophobic epoxide selected from butylene oxide, and the molecular weight of the alkoxylated alcohol is from 500 to 10,000 g / mol.

[0070] In another form of the alkoxylated alcohol, the alcohol is a C2-C3 alkanediol that is alkoxylated with a hydrophobic epoxide selected from butylene oxide, and the molecular weight of the alkoxylated alcohol is from 1,000 to 8,000 g / mol.

[0071] The alkoxylated alcohol is preferably an alkoxylated polytetrahydrofuran. In a preferred embodiment, the alkoxylated alcohol is represented by the general formula (I): [ka] (In the formula, m is an integer ranging from 1 to 50; m' is an integer ranging from 1 to 50; (m+m') is an integer ranging from 1 to 90, and n is an integer ranging from 0 to 75; n' is an integer ranging from 0 to 75; p is an integer ranging from 0 to 75; p' is an integer ranging from 0 to 75; k is an integer ranging from 2 to 30; R 1 represents an unsubstituted linear or branched alkyl group having 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27 or 28 carbon atoms; R 2 represents -CH2-CH3, R 3 are the same or different and represent a hydrogen atom or -CH3, The linkages represented by k are distributed to form a block polymer structure, and the linkages represented by p, p', n, n', m and m' are distributed to form a block polymer structure or a random polymer structure.

[0072] In another preferred embodiment, the alkoxylated alcohol has the general formula (I): [ka] (In the formula, m is an integer ranging from 1 to 30; m' is an integer ranging from 1 to 30; (m+m') is an integer ranging from 2 to 60, and n is an integer ranging from 0 to 45; n' is an integer ranging from 0 to 45; (n+n') is an integer ranging from 0 to 80, and p is an integer ranging from 0 to 25, p' is an integer ranging from 0 to 25; (p+p') is an integer ranging from 0 to 30, and k is an integer ranging from 2 to 30; R 1 represents an unsubstituted linear or branched alkyl group having 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27 or 28 carbon atoms; R 2 represents -CH2-CH3, R3 are the same or different and represent a hydrogen atom or -CH3, The linkages represented by k are distributed to form a block polymer structure, and the linkages represented by p, p', n, n', m, and m' are distributed to form a block polymer structure or a random polymer structure.

[0073] Preferably, the alkoxylated polytetrahydrofuran has a viscosity of 200 mm at 40° C., determined according to ASTM D445. 2 / s to 700mm 2 / s range, more preferably 250 mm 2 / s to 650mm 2 / s range of kinematic viscosity.

[0074] Preferably, the alkoxylated polytetrahydrofuran has a viscosity of 25 mm at 100° C., determined according to ASTM D445. 2 / s to 90mm 2 / s range, more preferably 30 mm 2 / s to 80mm 2 / s range of kinematic viscosity.

[0075] Preferably, the alkoxylated polytetrahydrofuran has a pour point, determined according to DIN ISO 3016, in the range of from -60°C to 20°C, more preferably in the range of from -50°C to 15°C.

[0076] Preferably, the alkoxylated polytetrahydrofuran has a weight average molecular weight Mw, determined according to DIN 55672-1, in the range of 500 to 20 000 g / mol, more preferably in the range of 2 000 to 10 000 g / mol, most preferably in the range of 2 000 to 7 000 g / mol, even more preferably in the range of 4 000 to 7 000 g / mol.

[0077] Preferably, the alkoxylated polytetrahydrofuran has a polydispersity, determined according to DIN 55672-1, in the range of 1.05 to 1.60, more preferably in the range of 1.05 to 1.50, most preferably in the range of 1.05 to 1.45.

[0078] Preferably, k is an integer in the range of 3-25, more preferably, k is an integer in the range of 3-20, most preferably, in the range of 5-20, and even more preferably, in the range of 6-16.

[0079] Preferably, m is an integer in the range of 1 to 25, and m' is an integer in the range of 1 to 25, and more preferably, m is an integer in the range of 1 to 20, and m' is an integer in the range of 1 to 20.

[0080] Preferably, (m+m') is an integer in the range of 3 to 65, more preferably, (m+m') is an integer in the range of 3 to 50, and even more preferably, (m+m') is an integer in the range of 3 to 40.

[0081] Preferably, the ratio of (m+m') to k is in the range of 0.3:1 to 6:1, more preferably in the range of 0.3:1 to 5:1, most preferably in the range of 0.3:1 to 4:1, and even more preferably in the range of 0.3:1 to 3:1.

[0082] Preferably, n is an integer in the range of 6 to 40, and n' is an integer in the range of 6 to 40, and more preferably, n is an integer in the range of 8 to 35, and p' is an integer in the range of 8 to 35.

[0083] Preferably, (n+n') is an integer in the range of 10-80, and more preferably, (n+n') is an integer in the range of 15-70.

[0084] Preferably, p is an integer in the range of 5 to 25, and p' is an integer in the range of 5 to 25, and more preferably, p is an integer in the range of 5 to 15, and p' is an integer in the range of 5 to 15.

[0085] Preferably, (p+p') is an integer in the range of 10-30, and more preferably, (p+p') is an integer in the range of 15-30.

[0086] Preferably, R 1 represents an unsubstituted linear alkyl group having 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17 or 18 carbon atoms. More preferably, R 1 represents an unsubstituted linear alkyl group having 8, 9, 10, 11, 12, 13, 14, 15 or 16 carbon atoms. 1 represents an unsubstituted straight chain alkyl group having 8, 9, 10, 11 or 12 carbon atoms.

[0087] The alkoxylated polytetrahydrofuran is R 2 When contains a unit representing -CH2-CH3, the ratio of (n+n') to k is in the range of 1.5:1 to 10:1, more preferably in the range of 1.5:1 to 6:1, and most preferably in the range of 2:1 to 5:1.

[0088] The alkoxylated polytetrahydrofuran is R 3 When contains a unit representing -CH3, the ratio of (p+p') to k is in the range of 1.2:1 to 10:1, and more preferably in the range of 1.2:1 to 6:1.

[0089] In another preferred embodiment, the alkoxylated alcohol has the general formula (I): [ka] (In the formula, m is an integer ranging from 1 to 30; m' is an integer ranging from 1 to 30; (m+m') is an integer ranging from 3 to 50; n is an integer ranging from 3 to 45; n' is an integer ranging from 3 to 45; (n+n') is an integer ranging from 6 to 90; p is an integer ranging from 0 to 75; p' is an integer ranging from 0 to 75; k is an integer ranging from 3 to 25; (p+p') is an integer ranging from 0 to 30, k is an integer ranging from 3 to 25; R 1 represents an unsubstituted linear alkyl group having 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17 or 18 carbon atoms; R 2 represents -CH2-CH3, R 3 represents -CH3, The linkages represented by k are distributed to form a block polymer structure, and the linkages represented by p, p', n, n', m and m' are distributed to form a block polymer structure or a random polymer structure.

[0090] In another preferred embodiment, the alkoxylated alcohol has the general formula (I): [ka] (In the formula, m is an integer ranging from 1 to 30; m' is an integer ranging from 1 to 30; (m+m') is an integer ranging from 3 to 50; n is an integer ranging from 3 to 45; n' is an integer ranging from 3 to 45; (n+n') is an integer ranging from 6 to 90; p is an integer ranging from 0 to 75; p' is an integer ranging from 0 to 75; k is an integer ranging from 3 to 25; (p+p') is an integer ranging from 0 to 30, k is an integer ranging from 3 to 25; R 1 represents an unsubstituted linear alkyl group having 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17 or 18 carbon atoms; R 2 represents -CH2-CH3, R 3 represents -CH3, wherein the linkages represented by k are distributed to form a block polymer structure, and the linkages represented by p, p', n, n', m, and m' are distributed to form a block polymer structure or a random polymer structure, and the ratio of (m+m') to k is in the range of 0.3:1 to 6:1, and the ratio of (n+n') to k is in the range of 1.5:1 to 10:1.

[0091] In another preferred embodiment, the alkoxylated alcohol has the general formula (I): [ka] (In the formula, m is an integer ranging from 1 to 25; m' is an integer ranging from 1 to 25; (m+m') is an integer ranging from 3 to 40; n is an integer ranging from 6 to 40; n' is an integer ranging from 6 to 40; (n+n') is an integer ranging from 12 to 70; p is an integer ranging from 0 to 25; p' is an integer ranging from 0 to 25; (p+p') is an integer ranging from 0 to 30, k is an integer ranging from 5 to 20; R 1 represents an unsubstituted linear alkyl group having 8, 9, 10, 11 or 12 carbon atoms; R 2 represents -CH2-CH3, R 3 represents -CH3, The linkages represented by k are distributed to form a block polymer structure, and the linkages represented by p, p', n, n', m, and m' are distributed to form a block polymer structure or a random polymer structure; The ratio of (m+m') to k is in the range of 0.3:1 to 4:1, and the ratio of (n+n') to k is in the range of 1.5:1 to 5:1.

[0092] In another preferred embodiment, the alkoxylated alcohol has the general formula (I): [ka] (In the formula, m is an integer ranging from 1 to 25; m' is an integer ranging from 1 to 25; (m+m') is an integer ranging from 3 to 50; n is an integer ranging from 0 to 45; n' is an integer ranging from 0 to 45; (n+n') is an integer ranging from 0 to 80, p is an integer ranging from 3 to 45; p' is an integer ranging from 3 to 45; (p+p') is an integer ranging from 6 to 90, k is an integer ranging from 3 to 25; R 1 represents an unsubstituted linear alkyl group having 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17 or 18 carbon atoms; R 2 represents -CH2-CH3, R 3 represents -CH3, The linkages represented by k are distributed to form a block polymer structure, and the linkages represented by p, p', n, n', m and m' are distributed to form a block polymer structure or a random polymer structure.

[0093] In another preferred embodiment, the alkoxylated alcohol is a lubricant having the general formula (I): [ka] (In the formula, m is an integer ranging from 1 to 30; m' is an integer ranging from 1 to 30; (m+m') is an integer ranging from 3 to 50; n is an integer ranging from 0 to 45; n' is an integer ranging from 0 to 45; (n+n') is an integer ranging from 0 to 80, p is an integer ranging from 3 to 45; p' is an integer ranging from 3 to 45; (p+p') is an integer ranging from 6 to 90, k is an integer ranging from 3 to 25; R 1 represents an unsubstituted linear alkyl group having 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17 or 18 carbon atoms; R 2 represents -CH2-CH3, R 3 represents -CH3, wherein the linkages represented by k are distributed to form a block polymer structure, and the linkages represented by p, p', n, n', m, and m' are distributed to form a block polymer structure or a random polymer structure, and the ratio of (m+m') to k is in the range of 0.3:1 to 6:1, and the ratio of (p+p') to k is in the range of 1.5:1 to 10:1.

[0094] In another preferred embodiment, the alkoxylated alcohol has the general formula (I): [ka] (In the formula, m is an integer ranging from 1 to 25; m' is an integer ranging from 1 to 25; (m+m') is an integer ranging from 3 to 50; n is an integer ranging from 0 to 45; n' is an integer ranging from 0 to 45; (n+n') is an integer ranging from 0 to 80, p is an integer ranging from 5 to 20; p' is an integer ranging from 5 to 20; (p+p') is an integer ranging from 10 to 30, k is an integer ranging from 5 to 20; R 1 represents an unsubstituted linear alkyl group having 8, 9, 10, 11 or 12 carbon atoms; R 2 represents -CH2-CH3, R 3 represents -CH3, wherein the linkages represented by k are distributed to form a block polymer structure, and the linkages represented by p, p', n, n', m, and m' are distributed to form a block polymer structure or a random polymer structure, and the ratio of (m+m') to k is in the range of 0.3:1 to 4:1, and the ratio of (p+p') to k is in the range of 1.5:1 to 5:1.

[0095] Alkoxylated polytetrahydrofuran is typically prepared by esterifying at least one polytetrahydrofuran block polymer with at least one C8-C 30 It can be obtained by reacting an epoxyalkane with, optionally, at least one epoxide selected from the group consisting of ethylene oxide, propylene oxide and butylene oxide. When at least one epoxide selected from the group consisting of ethylene oxide, propylene oxide and butylene oxide is used, at least one C8-C 30 The epoxyalkane and at least one epoxide selected from the group consisting of ethylene oxide, propylene oxide, and butylene oxide can be added as a mixture of epoxides to obtain a random copolymer, or in portions (wherein each portion contains a different epoxide) to obtain a block copolymer.

[0096] Preferably, at least one C8-C 30The epoxyalkane is selected from the group consisting of 1,2-epoxyoctane, 1,2-epoxynonane, 1,2-epoxydecane, 1,2-epoxyundecane, 1,2-epoxydodecane, 1,2-epoxytridecane, 1,2-epoxytetradecane, 1,2-epoxypentadecane, 1,2-epoxyhexadecane, 1,2-epoxyheptadecane, 1,2-epoxyoctadecane, 1,2-epoxynonadecane, 1,2-epoxyicosane, 1,2-epoxyunicosane, 1,2-epoxydocosane, 1,2-epoxytricosane, 1,2-epoxytetracosane, 1,2-epoxypentacosane, 1,2-epoxyhexacosane, 1,2-epoxyheptacosane, 1,2-epoxyoctacosane, 1,2-epoxynonacosane, and 1,2-epoxytriacontane.

[0097] Alkoxylated alcohols are typically oil soluble, which may mean that when mixed with a hydrocarbon in weight ratios of 10:90, 50:50, and 90:10, the alkoxylated alcohols do not exhibit phase separation after standing at room temperature for 24 hours in at least two of the three weight ratios of 10:90, 50:50, and 90:10.

[0098] The lubricant may comprise 2-99 wt.%, preferably 2-50 wt.%, more preferably 10-25 wt.% of an alkoxylated alcohol. In another embodiment, the lubricant comprises 5-99 wt.%, 10-50 wt.%, or 15-50 wt.% of an alkoxylated alcohol. In another embodiment, the lubricant comprises 3-40 wt.%, 5-30 wt.%, or 5-20 wt.% of an alkoxylated alcohol.

[0099] The lubricant does not usually contain ionic liquids. Ionic liquids are usually salts with a melting point of less than 100° C. at 1 bar. Ionic liquids can be liquid under normal conditions (1 bar, room temperature). Ionic liquids can contain at least one organic compound as a cation, such as a quaternary ammonium cation, for example, a pyridinium cation, a pyridazinium cation, a pyrimidinium cation, a pyrazinium cation, an imidazolinium cation, a pyrazolium cation, a pyrazolinium cation, an imidazolinium cation, a thiazolium cation, a triazolium cation, a pyrrolidinium cation and an imidazolidinium cation.

[0100] The lubricant has a kinematic viscosity of 1 to 100 mm at 100°C, which can be determined in accordance with ASTM D445. 2 / s.

[0101] The lubricant may further comprise lubricant additives in addition to the base stock selected from hydrocarbons, water and alkoxylated alcohols. Suitable lubricant additives may be selected from viscosity index improvers, polymeric thickeners, corrosion inhibitors, detergents, dispersants, antifoam agents, dyes, antiwear additives, extreme pressure additives (EP additives), antiwear additives (AW additives), friction modifiers, metal deactivators, pour point depressants.

[0102] The combined total amount of the lubricant additives in the lubricant may comprise in the range of 0 to 25%, or 0.01 to 20%, or 0.1 to 15%, or 0.5 to 10%, or 1 to 5% by weight of the lubricant.

[0103] Viscosity index improvers include high molecular weight polymers that increase the relative viscosity of oils at high temperatures compared to their relative viscosity at low temperatures. Viscosity index improvers include polyacrylates, polymethacrylates, alkyl methacrylates, vinylpyrrolidone / methacrylate copolymers, polyvinylpyrrolidones, polybutenes, olefin copolymers such as ethylene-propylene copolymers or styrene-butadiene copolymers, or polyalkenes such as PIB, styrene / acrylate copolymers, and polyethers, and combinations thereof. The most common Vl improvers are methacrylate polymers and copolymers, acrylate polymers, olefin polymers and copolymers, and styrene-butadiene copolymers. Other examples of viscosity index improvers include polymethacrylates, polyisobutylenes, α-olefin polymers, α-olefin copolymers (e.g., ethylene-propylene copolymers), polyalkylstyrenes, phenol condensates, naphthalene condensates, styrene-butadiene copolymers, and the like. Of these, preferred are polymethacrylates having a number average molecular weight of 10,000 to 300,000, and α-olefin polymers or α-olefin copolymers having a number average molecular weight of 1,000 to 30,000, in particular ethylene-α-olefin copolymers having a number average molecular weight of 1,000 to 10,000. The viscosity index improvers can be used alone or in the form of a mixture, conveniently added in an amount within the range of 0.05% to 20.0% by weight relative to the weight of the base stock.

[0104] Suitable (polymeric) thickeners include, but are not limited to, polyisobutene (PIB), oligomeric copolymers (OCP), polymethacrylates (PMA), copolymers of styrene and butadiene, or high viscosity esters (complex esters).

[0105] Corrosion inhibitors can include a variety of oxygen-, nitrogen-, sulfur-, and phosphorus-containing materials, metal-containing compounds (salts, organometallics, etc.), and non-metal-containing or ashless materials. Corrosion inhibitors include, for example, hydrocarbyl-, aryl-, alkyl-, arylalkyl-, and alkylaryl-type detergents (neutral, overbased), sulfonates, phenates, salicylates, alcoholates, carboxylates, salixarates, phosphites, phosphates, thiophosphates, amines, amine salts, amine phosphates, amine sulfonates, alkoxylated amines, ether amines, polyether amines, amides, imides, azoles, diazoles, triazoles, benzotriazoles, benzothiadols, mercaptan ... Additive types that may be mentioned include, but are not limited to, captobenzothiazoles, tolyltriazoles (TTZ type), heterocyclic amines, heterocyclic sulfides, thiazoles, thiadiazoles, mercaptothiadiazoles, dimercaptothiadiazoles (DMTD type), imidazoles, benzimidazoles, dithiobenzimidazoles, imidazolines, oxazolines, Mannich reaction products, glycidyl ethers, anhydrides, carbamates, thiocarbamates, dithiocarbamates, polyglycols, and the like, or mixtures thereof.

[0106] Detergents include detergents that adhere to dirt particles and prevent them from adhering to critical surfaces. Detergents can also adhere to the metal surface itself to keep it clean and prevent corrosion from occurring. Detergents include calcium alkyl salicylates, calcium alkyl phenates, and calcium alkaryl sulfonates, with alternative metal ions such as magnesium, barium, or sodium being used. Examples of detergents and dispersants that can be used include metal-based detergents such as neutral and basic alkaline earth metal sulfonates, alkaline earth metal phenates, and alkaline earth metal salicylates, alkenyl succinimides and alkenyl succinimide esters and their boron hydrogen, phenates, salienius complex detergents, and ashless dispersants modified with sulfur compounds. These agents can be used singly or in the form of mixtures, conveniently added in amounts ranging from 0.01% to 1.0% by weight based on the weight of the base stock, and they can also be high total base number (TBN), low TBN, or high / low TBN mixtures.

[0107] Dispersants are lubricant additives that help prevent the formation of sludge, varnish, and other deposits on critical surfaces. Dispersants can be succinimide dispersants (e.g., N-substituted long chain alkenyl succinimides), Mannich dispersants, ester-containing dispersants, condensation products of fatty hydrocarbyl monocarboxylic acylating agents with amines or ammonia, alkylaminophenol dispersants, hydrocarbyl-amine dispersants, polyether dispersants, or polyetheramine dispersants. In one embodiment, succinimide dispersants include polyisobutylene-substituted succinimides, where the polyisobutylene from which the dispersant is derived can have a number average molecular weight of about 400 to about 5000, or about 950 to about 1600. In one embodiment, dispersants include borated dispersants. Typically, borated dispersants include succinimide dispersants, including polyisobutylene succinimides, where the polyisobutylene from which the dispersant is derived can have a number average molecular weight of about 400 to about 5000. Borated dispersants are described in more detail above in the description of extreme pressure agents.

[0108] The antifoaming agent may be selected from silicones, polyacrylates, and the like. The amount of antifoaming agent in the lubricant compositions described herein may range from 0.001% to 0.1% by weight, based on the total weight of the formulation. By way of further example, the antifoaming agent may be present in an amount of about 0.004% to about 0.008% by weight.

[0109] Suitable extreme pressure agents are sulfur-containing compounds. In one embodiment, the sulfur-containing compound may be a sulfurized olefin, a polysulfide, or a mixture thereof. Examples of sulfurized olefins include sulfurized olefins derived from propylene, isobutylene, pentene, polysulfides including organic sulfides and / or benzyl disulfides, bis-(chlorobenzyl) disulfide, dibutyl tetrasulfide, di-tertiary butyl polysulfide, as well as sulfurized methyl ester of oleic acid, sulfurized alkylphenols, sulfurized dipentenes, sulfurized terpenes, sulfurized Diels-Alder adducts, alkylsulfenyl N'N-dialkyldithiocarbamates, or mixtures thereof. In one embodiment, the sulfurized olefins include sulfurized olefins derived from propylene, isobutylene, pentene, or mixtures thereof. In one embodiment, the sulfur-containing compound of the extreme pressure additive includes dimercaptothiadiazole or derivatives, or mixtures thereof. Examples of dimercaptothiadiazoles include compounds such as 2,5-dimercapto-1,3,4-thiadiazole or hydrocarbyl-substituted 2,5-dimercapto-1,3,4-thiadiazoles, or oligomers thereof. Hydrocarbyl-substituted 2,5-dimercapto-1,3,4-thiadiazole oligomers are typically formed by forming sulfur-sulfur bonds between 2,5-dimercapto-1,3,4-thiadiazole units to form derivatives or oligomers of two or more of the thiadiazole units. Suitable 2,5-dimercapto-1,3,4-thiadiazole derived compounds include, for example, 2,5-bis(tert-nonyldithio)-1,3,4-thiadiazole, or 2-tert-nonyldithio-5-mercapto-1,3,4-thiadiazole. The number of carbon atoms of the hydrocarbyl substituent of the hydrocarbyl-substituted 2,5-dimercapto-1,3,4-thiadiazole is typically 1 to 30, or 2 to 20, or 3 to 16. The extreme pressure additive includes a compound containing boron and / or sulfur and / or phosphorus. The extreme pressure agent may be present in the lubricant composition at 0% to about 20% by weight, or about 0.05% to about 10.0% by weight, or about 0.1% to about 8% by weight of the lubricant composition.

[0110] Examples of anti-wear additives include organic borates, organic phosphites such as didodecyl phosphite, organic sulfur-containing compounds such as sulfurized sperm oil or sulfurized terpenes, zinc dialkyldithiophosphates, zinc diaryldithiophosphates, phosphosulfurized hydrocarbons, and any combination thereof.

[0111] Friction modifiers can include metal-containing compounds or materials, as well as ashless compounds or materials, or mixtures thereof. Metal-containing friction modifiers include metal salts or metal-ligand complexes, where the metal can include alkali metals, alkaline earth metals, or transition metals. Such metal-containing friction modifiers can also have low ash characteristics. Transition metals can include Mo, Sb, Sn, Fe, Cu, Zn, and the like. Ligands can include hydrocarbyl derivatives of alcohols, polyols, glycerol, partial ester glycerol, thiols, carboxylates, carbamates, thiocarbamates, dithiocarbamates, phosphates, thiophosphates, dithiophosphates, amides, imides, amines, thiazoles, thiadiazoles, dithiazoles, diazoles, triazoles, and other polar molecular functional groups containing effective amounts of O, N, S, or P, alone or in combination. In particular, Mo-containing compounds such as Mo-dithiocarbamates, Mo(DTC), Mo-dithiophosphates, Mo(DTP), Mo-amines, Mo(Am), Mo-alcoholates, Mo-alcohol-amides, and the like, may be particularly effective.

[0112] Ashless friction modifiers can also include lubricant materials containing effective amounts of polar groups, such as hydroxyl-containing hydrocarbyl base oils, glycerides, partial glycerides, glyceride derivatives, and the like. Polar groups in friction modifiers can include hydrocarbyl groups containing effective amounts of O, N, S, or P, alone or in combination. Other friction modifiers that may be particularly effective include, for example, salts of fatty acids (both ash-containing and ashless derivatives), fatty alcohols, fatty amides, fatty esters, hydroxyl-containing carboxylates, and equivalent synthetic long-chain hydrocarbyl acids, alcohols, amides, esters, hydroxycarboxylates, and the like. In some cases, fatty organic acids, fatty amines, and sulfurized fatty acids can be used as suitable friction modifiers. Examples of friction modifiers include fatty acid esters and amides, organomolybdenum compounds, molybdenum dialkylthiocarbamates, and molybdenum dialkyldithiophosphates.

[0113] Suitable metal deactivators include benzotriazole and its derivatives, such as 4- or 5-alkylbenzotriazoles (e.g., triazoles) and their derivatives, 4,5,6,7-tetrahydrobenzotriazole, and 5,5'-methylenebisbenzotriazole, Mannich bases of benzotriazoles or triazoles, such as 1-[bis(2-ethylhexyl)aminomethyl)triazole and 1-[bis(2-ethylhexyl)aminomethyl)benzotriazole, and alkoxyalkylbenzotriazoles, such as 1-(nonyloxymethyl)benzotriazole, 1-(1-butoxyethyl)benzotriazole, and 1-(1-cyclohexyloxybutyl)triazole, and combinations thereof. Additional non-limiting examples of the one or more metal deactivators include 1,2,4-triazole and its derivatives, such as 3-alkyl (or aryl)-1,2,4-triazoles, and Mannich bases of 1,2,4-triazoles, such as 1-[bis(2-ethylhexyl)aminomethyl-1,2,4-triazole, alkoxyalkyl-1,2,4-triazoles, such as 1-(1-butoxyethyl)-1,2,4-triazole, and acylated 3-amino-1,2,4-triazoles, imidazole derivatives, such as 4,4'-methylenebis(2-undecyl-5-methylimidazole) and bis[(N-methyl)imidazol-2-yl]carbinol octyl ether, and combinations thereof. Further non-limiting examples of the one or more metal deactivators include sulfur-containing heterocyclic compounds, such as 2-mercaptobenzothiazole, 2,5-dimercapto-1,3,4-thiadiazole, and derivatives thereof, and 3,5-bis-[di(2-ethylhexyl)aminomethyl]-1,3,4-thiadiazolin-2-one, and combinations thereof. Further non-limiting examples of the one or more metal deactivators include amino compounds, such as salicylidene propylene diamine, salicylamino guanidine, and salts thereof, and combinations thereof.The one or more metal deactivators are not particularly limited in amount in the composition, but are typically present in an amount of about 0.01 to about 0.1 wt%, about 0.05 to about 0.01 wt%, or about 0.07 to about 0.1 wt%, based on the weight of the composition. Alternatively, the one or more metal deactivators may be present in an amount less than about 0.1 wt%, less than about 0.7 wt%, or less than about 0.5 wt%, based on the weight of the composition.

[0114] Pour point depressants (PPDs) include polymethacrylates, alkylated naphthalene derivatives, and combinations thereof. Commonly used additives such as alkyl aromatic polymers and polymethacrylates are also useful for this purpose. Typically, treat rates range from 0.001% to 1.0% by weight based on the weight of the base stock.

[0115] Demulsifiers include trialkyl phosphates and various polymers and copolymers of ethylene glycol, ethylene oxide, propylene oxide, or mixtures thereof.

[0116] The present invention also relates to a method of lubricating a mechanical device of an electric vehicle, comprising the step of contacting the mechanical device with a lubricant.

[0117] Suitable electric vehicles include fully electric vehicles and hybrid electric vehicles. Electric vehicles typically include a rotating electric machine and a power storage device configured to store electrical power used to drive the rotating electric machine. Hybrid electric vehicles typically use electrical power from the rotating electric machine and a combustion engine to run.

[0118] Suitable hybrid electric vehicles are full hybrids (also called strong hybrids), plug-in hybrid (also called PHEV) electric vehicles, or range extended electric vehicles (also called REEVs). Full hybrid electric vehicles are typically vehicles that can run on only the combustion engine, only the electric motor, or a combination of both. Plug-in hybrid electric vehicles are typically hybrid electric vehicles with a rechargeable battery that can be returned to a full charge by connecting the plug to an external power source.

[0119] Suitable electric vehicles are battery electric vehicles (also referred to as BEVs) or fuel cell electric vehicles. BEVs are a type of electric vehicle that typically uses chemical energy stored in a rechargeable battery pack and an electric motor and motor controller instead of an internal combustion engine for propulsion. Fuel cell electric vehicles (FCEVs) are a type of electric vehicle that typically uses a fuel cell instead of a battery, or in combination with a battery or supercapacitor, to power its on-board rotating electric machine. Fuel cells in vehicles typically use oxygen from the air and compressed hydrogen to generate electricity to power the motor.

[0120] The term "vehicle" refers to any mobile or stationary platform, although in this case mobile platforms are preferred. In particular, the vehicle is selected from a passenger car, a light or heavy truck, a utility vehicle, an agricultural vehicle, an industrial or warehouse vehicle, or a recreational off-road vehicle.

[0121] Lubrication of the machinery of an electric vehicle may refer to the lubrication of the powertrain, driveline, transmission, differential, gear, gear train, gear set, gear box, bearing, bushing, axle, turbine, compressor, pump, hydraulic system, battery, capacitor, electric motor, traction motor, generator, AC / DC converter, alternator, transformer, kinetic energy converter, kinetic energy recovery system. A single lubricant or multiple lubricants may be used in an electric vehicle, for example, one lubricant composition for the transmission and another lubricant composition for another component of the vehicle system.

[0122] The present invention also relates to the use of alkoxylated alcohols to increase the breakdown voltage of lubricants containing base stocks selected from hydrocarbons.

[0123] Preferably, the breakdown voltage of the lubricant containing the alkoxylated alcohol is at least 100, 500, 1000, 2000, or 5000 V higher than the lubricant without the alkoxylated alcohol.

[0124] Preferably, the alkoxylated alcohols for increasing the breakdown voltage of lubricants comprising base stocks selected from hydrocarbons are used in electric vehicles.

[0125] The present invention also relates to the use of alkoxylated alcohols in lubricants containing base stocks selected from hydrocarbons to reduce electrical discharge machining. EXAMPLES

[0126] Base stock A: API Group III base stock, YUBASE 3 from SK Lubricants Ltd, transparent liquid hydrocarbon, mineral oil, kinematic viscosity (ASTM D445) 12,4mm at 40°C 2 / s, 3,1mm at 100℃ 2 / s, viscosity index 112 (ASTM D2270), and sulfur content less than 10 ppm (ASTM D2622).

[0127] Base Stock B: API Group III base stock, YUBASE 6 from SK Lubricants Ltd, transparent liquid hydrocarbon, mineral oil, kinematic viscosity (ASTM D445) 36,8mm at 40°C 2 / s, 6,5mm at 100℃ 2 / s, viscosity index 131 (ASTM D2270), and sulfur content less than 10 ppm (ASTM D2622).

[0128] Additive Pack: An additive package was added that included commercial additives from the categories of antioxidants, anti-wear additives, corrosion inhibitors, metal deactivators, and silicone oils.

[0129] Polyalphaolefin 150: Highly branched isoparaffinic polyalphaolefin, kinematic viscosity 1719 mm at 40°C 2 / s, 156 mm at 100°C 2 / s, Chevron Phillips Synfluid mPAO 150cST.

[0130] Polymethyl acrylate: Polyalkyl methacrylate viscosity index improver, linear and branched C 12-15 It has an alkyl group and a permanent shear stability index of about 20 (20 hour KRL, determined according to CEC L-45-99).

[0131] Alkoxylate A: A liquid alkoxylated alcohol, in this case the alcohol is polytetrahydrofuran (molecular weight about 650 g / mol) which is randomly alkoxylated with 12 equivalents of dodecyl epoxide and 20 equivalents of propylene oxide, with a kinematic viscosity (ASTM D445) of about 320-350 mm at 40° C. 2 / s.

[0132] Example 1 Lubricants A, B, and C were prepared from base stock A, additive pack (1.1 wt. % concentration), and base stock B, polymethylacrylate (comparative), polyalphaolefin 150 (comparative), or alkoxylate A in the amounts shown in Table 1. The amounts of base stock B, polymethylacrylate, polyalphaolefin 150, and alkoxylate A were adjusted so that the KV100 of the final lubricant was 5 mm 2 It has been adjusted to / s.

[0133] The kinematic viscosities at 40°C (KV40) and 100°C (KV100) were determined according to ASTM D445. From these data the viscosity index VI was calculated. The water content of the final lubricants was determined by the Karl Fischer method (DIN 517771 / ASTM D1744). The breakdown voltage of the final lubricants was determined according to DIN EN 60156 ("Insulating liquids - Determination of the breakdown voltage at power frequency - Test method").

[0134] The results are summarized in Table 1 and demonstrate an increased breakdown voltage for Lubricant E. A high breakdown voltage is advantageous because the lubricant acts as an insulator.

[0135] Comparative lubricant A has a very low water content of 20 ppm. Typically, hydrocarbons with low water content have an increased breakdown voltage, which can be seen by comparing comparative lubricants C and D. Surprisingly, lubricant E has a higher breakdown voltage despite having a higher water content of 300 ppm.

[0136] [Table 1]

[0137] Example 2 The EDM (electrical discharge machining) currents of lubricants A, B and C of Example 1 were analyzed in a test setup in which a common mode voltage was applied to the rolling bearing and the resulting bearing currents were recorded according to R. Pelz et al. “Charakterisierung von E-Fluiden von der Laboranalytik bis zum Pruefstand”, MTZ - Motorentechnische Zeitschrift, 2021 (10), 46-50. The temperature was varied from 30 to 80 ° C and the common mode voltage was varied between 5, 10 and 20 volts.

[0138] The results are summarized in Table 2 and demonstrate a reduction in the total EDM current for Lubricant C. A reduction in the total EDM current is advantageous as EDM current can damage bearings.

[0139] [Table 2]

[0140] [Table 3]

Claims

1. A method for lubricating the mechanical device of an electric vehicle, comprising the step of bringing a lubricant into contact with the mechanical device, wherein the lubricant is - A base stock selected from hydrocarbons, -50 to 1000 ppm water, -C ４ -C ２０ A method comprising: an alkoxylated alcohol being alkoxylated with a hydrophobic epoxide selected from epoxides;

2. The method according to claim 1, wherein the hydrophobic epoxide is selected from butylene oxide, dodecyl oxide, or a mixture thereof.

3. The method according to claim 1, wherein the alcohol is alkoxylated with the hydrophobic epoxide and optionally further alkoxylated with propylene oxide.

4. The aforementioned alcohol is C １ -C ２２ Monoalcohol, C ２ -C １２ Diol, polyethylene glycol, polypropylene glycol, polytetrahydrofuran, or C ３ -C １２ The method according to claim 1, wherein the polyol is selected from the polyols.

5. The method according to claim 1, wherein the lubricant comprises 2 to 50% by weight, preferably 10 to 25% by weight, of the alkoxylated alcohol.

6. The method according to claim 1, wherein the hydrocarbon is selected from base stocks of API groups I, II, III, or IV, or mixtures thereof.

7. The method according to claim 1, wherein the lubricant does not contain a base stock of API group V.

8. The method according to claim 1, wherein the breakdown voltage of the base stock is a maximum of 500 volts.

9. The alkoxylated alcohol is of general formula (I) 【Chemistry 1】 (In the formula, m is an integer in the range of 1 to 50. m' is an integer in the range of 1 to 50. (m + m') is an integer in the range of 1 to 90. n is an integer in the range of 0 to 75. n' is an integer in the range of 0 to 75. p is an integer in the range of 0 to 75. p' is an integer in the range of 0 to 75. k is an integer in the range of 2 to 30. R １ represents an unsubstituted straight-chain or branched-chain alkyl group having 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27 or 28 carbon atoms, R ２ is, -CH ２ -CH ３ This represents, R ３ These are identical or different, hydrogen atoms or -CH ３ This represents, The method according to claim 1, wherein the linkage represented by k is distributed to form a block polymer structure, and the linkages represented by p, p', n, n', m, and m' are distributed to form a block polymer structure or a random polymer structure.

10. The method according to claim 1, wherein the lubricant comprises at least 50% by weight of the base stock.

11. - A base stock selected from hydrocarbons selected from base stocks of API Group I, II, or III, -50 to 1000 ppm water, -C ４ -C ２０ Alkoxylated with a hydrophobic epoxide selected from epoxides, C ２ -C １２ A lubricant as defined in any one of claims 1 to 10, comprising an alkoxylated alcohol which is a diol selected from diols, polyethylene glycol, polypropylene glycol, and polytetrahydrofuran.

12. Use of an alkoxylated alcohol as defined in any one of claims 1 to 10 to increase the yield voltage of a lubricant comprising the base stock selected from the hydrocarbons.

13. The use according to claim 12, wherein the breakdown voltage of the lubricant containing the alkoxylated alcohol is at least 100 V higher than that of the lubricant without the alkoxylated alcohol.

14. Use of an alkoxylated alcohol as defined in any one of claims 1 to 10 in a lubricant comprising the base stock selected from the hydrocarbons for reducing electrical discharge machining.

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