Lubricating oil composition for gearbox of electric vehicle and preparation method of lubricating oil composition

Abstract

The invention provides an electric vehicle transmission lubricating oil composition and a preparation method thereof, and the electric vehicle transmission lubricating oil composition comprises the following components: (A) an ashless dispersant accounting for 1.0-5.0% of the total mass of the composition; (B) a viscosity index improver accounting for 0.5%-5.0% of the total mass of the composition; (C) an antioxidant accounting for 0.1%-3.0% of the total mass of the composition; (D) a metal deactivator accounting for 0.01%-0.3% of the total mass of the composition; (E) phosphate ester salt which accounts for 0.2 to 2.0 percent of the total mass of the composition; and (F) a base oil which constitutes the main component of the composition. The lubricating oil composition for the gearbox of the electric vehicle has low viscosity, excellent copper corrosion resistance and high wear-resistant bearing performance.

Description

Technical Field

[0001] The present invention relates to the field of lubricating oils, and in particular to an electric vehicle gearbox lubricating oil composition and a preparation method thereof. Background Art

[0002] Unlike traditional fuel vehicles, electric vehicles use motors instead of engines, so new requirements are also put forward for the performance of the lubricants used in them. The technical development requirements of small, lightweight and low energy consumption of electric vehicles have led to the trend of integrated design of their motors and transmission systems, that is, the motor and reducer share a lubrication system, which has become the development trend of electric vehicle lubricants. At the same time, in order to improve the transmission efficiency of electric vehicles, low viscosity oil is also required. At present, electric vehicles on the market are mainly based on a first-gear reduction structure, and the transmission is directly driven by the motor. The maximum speed of the motor can reach more than 20,000r / min. The high input speed puts forward stringent requirements on the wear resistance and load-bearing performance of the transmission. In addition, a large number of copper parts are wrapped in the motor structure, so electric vehicle oils are also required to have excellent copper corrosion resistance.

[0003] Usually, the oil film thickness formed by low-viscosity oil during use is low, which is not conducive to the anti-wear and load-bearing performance of the oil. Therefore, to improve the anti-wear and load-bearing performance of the oil, it is necessary to start with high-performance extreme pressure anti-wear agents. In the formulated oil, extreme pressure anti-wear agents and corrosion inhibitors will compete for adsorption on the metal surface, especially extreme pressure anti-wear agents with high sulfur content will cause serious corrosion to copper parts.

[0004] CN111808658A discloses a lubricating oil composition containing phosphite and thiadiazole compound, which improves the sintering resistance and fatigue resistance of electric motors and transmissions, but does not investigate the effect of the additives on the copper corrosion resistance.

[0005] CN108218835A discloses a method for preparing a sulfur-nitrogen heterocyclic extreme pressure anti-wear agent and its application in new energy vehicle transmission oil. The extreme pressure anti-wear agent has a low dosage and good extreme pressure anti-wear performance, which reduces the cost of the transmission oil. However, the extreme pressure anti-wear agent has a greater corrosiveness to copper parts due to the introduction of sulfur element.

[0006] The above literature improves the extreme pressure and anti-wear performance of low-viscosity oils by introducing phosphorus-type, sulfur-type or sulfur-nitrogen-type extreme pressure and anti-wear agents, but it is difficult to take into account the copper corrosion resistance of the oils. Therefore, how to balance the low viscosity of the oil, excellent copper corrosion resistance and anti-wear and load-bearing performance is the focus of the development of electric vehicle oils. Summary of the invention

[0007] In order to solve the above technical problems, the present invention proposes an electric vehicle gearbox lubricating oil composition having low viscosity, excellent copper corrosion resistance and anti-wear load-bearing performance and a preparation method thereof.

[0008] The electric vehicle gearbox lubricating oil composition of the present invention comprises the following components:

[0009] (A) ashless dispersant, accounting for 1.0% to 5.0% of the total weight of the composition;

[0010] (B) a viscosity index improver, accounting for 0.5% to 5.0% of the total mass of the composition;

[0011] (C) an antioxidant, accounting for 0.1% to 3.0% of the total weight of the composition;

[0012] (D) metal deactivator, accounting for 0.01% to 0.3% of the total mass of the composition;

[0013] (E) phosphate salt, accounting for 0.2% to 2.0% of the total weight of the composition;

[0014] (F) base oil, constituting the main component of the composition;

[0015] The phosphate salt comprises a structural unit represented by formula (1) and at least one of the structural units represented by formula (2), formula (3) and formula (4),

[0016] Among them, R 1 and R 2 are each independently selected from hydrogen, hydrocarbyl, substituted hydrocarbyl or heteroalkyl;

[0017] Among them, X 1 R and R' are each independently selected from hydrogen or a C1-C4 hydrocarbon group; R 3 , R 4 and R 5 Each is independently selected from a C1-C5 hydrocarbon group, and r1 and r2 are each independently 0 or 1;

[0018] Among them, R 6 , R 7 and R 8 Each is independently selected from a C1-C5 hydrocarbon group, and r3 and r4 are each independently 0 or 1;

[0019] Wherein, R" is selected from hydrogen or C1-C4 hydrocarbon group, R 9 , R 10 and R 11r5 and r6 are each independently selected from a C1-C5 hydrocarbon group, and are each independently 0 or 1.

[0020] According to the present invention, the preparation method of the phosphate salt comprises:

[0021] The acidic phosphate having the structure shown in formula (5) is contacted with a nitrogen-containing organic substance having a bicyclic structure to react with a phosphate salt;

[0022] Among them, R 1 and R 2 are each independently selected from hydrogen, hydrocarbyl, substituted hydrocarbyl or heteroalkyl;

[0023] The nitrogen-containing organic compound has at least one of the structures shown in formula (6), formula (7) and formula (8),

[0024] Among them, X 1 R and R' are each independently selected from hydrogen or a C1-C4 hydrocarbon group; R 3 , R 4 and R 5 Each is independently selected from a C1-C5 hydrocarbon group, and r1 and r2 are each independently 0 or 1;

[0025] Among them, R 6 , R 7 and R 8 Each is independently selected from a C1-C5 hydrocarbon group, and r3 and r4 are each independently 0 or 1;

[0026] Wherein, R" is selected from hydrogen or C1-C4 hydrocarbon group, R 9 , R 10 and R 11 r5 and r6 are each independently selected from a C1-C5 hydrocarbon group, and are each independently 0 or 1.

[0027] According to the present invention, the phosphate ester salt does not contain metal elements, is not easy to produce ash, shows significant anti-wear properties at a relatively small dosage, and can effectively improve the anti-wear performance and load-bearing capacity of lubricating oil. In addition, when the phosphate ester salt is used as a lubricating oil anti-wear additive, it has low metal corrosion while showing excellent anti-wear properties.

[0028] According to the present invention, the ashless dispersant can be selected from polyisobutylene succinimide and / or boronated polyisobutylene succinimide, for example, one or more of monopolyisobutylene succinimide, dipolyisobutylene succinimide, high molecular weight polyisobutylene succinimide and boronated dipolyisobutylene succinimide can be selected, and common trade names include T151, T154, T161, T154B, etc.

[0029] According to the present invention, the viscosity index improver can be polymethacrylate and / or polyisobutylene. Common trade names include Viscoplex 8-219, TK-Chem6350, Viscoplex 8-310, PIB1400, etc., preferably with a kinematic viscosity of 500 to 1500 mm at 100°C. 2 / s polymethacrylate and / or polyisobutylene having a number average molecular weight of 1000 to 3400.

[0030] According to the present invention, the antioxidant can be selected from one or more of alkylated diphenylamine, N-phenyl-α-naphthylamine, shielded phenol and phenol ester, for example, one or more of dibutyl diphenylamine, dioctyl diphenylamine, butyl / octyl diphenylamine, didodecyl diphenylamine, dipentyl diphenylamine, 2,6-di-tert-butyl-p-cresol and 2,6-di-tert-butyl-4-hydroxyphenyl propionate can be selected. Common trade names include T534, T531, T501, etc.

[0031] According to the present invention, the metal deactivator is selected from one or more of alkylaminomethylenebenzotriazole, benzotriazole dialkylamine formaldehyde condensate, thiadiazole polysulfide and thiadiazole alkylthiol hydrogen peroxide condensate. Common trade names include T551, T552, T553, T571, T561, etc.

[0032] According to the present invention, the base oil can be selected from one or more of API I, II, III, IV and V base oils, for example, one or more of Class I base oil, Class II hydrogenated base oil, Class III hydrogenated base oil, poly α-olefin, alkylbenzene and alkylnaphthalene, preferably one or more of Class I base oil, Class II hydrogenated base oil, Class III hydrogenated base oil and poly α-olefin, more preferably a kinematic viscosity of 1 to 10 mm at 100°C. 2 / s base oil, and preferably has a kinematic viscosity of 3 to 6 mm at 100°C 2 / s base oil.

[0033] The preparation method of the electric vehicle gearbox lubricating oil composition of the present invention comprises the step of mixing various additives therein with base oil.

[0034] The electric vehicle gearbox lubricating oil composition of the present invention has low viscosity, excellent copper corrosion resistance and high anti-wear load-bearing performance. DETAILED DESCRIPTION

[0035] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0036] The present invention is further described in detail below in conjunction with the examples, but the present invention is not limited thereto. Unless otherwise specified, all ratios and parts are calculated by mass.

[0037] The first aspect of the present invention provides a phosphate salt, wherein the phosphate salt comprises a structural unit represented by formula (1) and at least one of the structural units represented by formula (2), formula (3) and formula (4),

[0038] Among them, R 1 and R 2 are each independently selected from hydrogen, hydrocarbyl, substituted hydrocarbyl or heteroalkyl;

[0039] Among them, X 1 R and R' are each independently selected from hydrogen or a C1-C4 hydrocarbon group; R 3 , R 4 and R 5 Each is independently selected from a C1-C5 hydrocarbon group, and r1 and r2 are each independently 0 or 1;

[0040] Among them, R 6 , R 7 and R 8 Each is independently selected from a C1-C5 hydrocarbon group, and r3 and r4 are each independently 0 or 1;

[0041] Wherein, R" is selected from hydrogen or C1-C4 hydrocarbon group, R 9 , R 10 and R 11 r5 and r6 are each independently selected from a C1-C5 hydrocarbon group, and are each independently 0 or 1.

[0042] In the prior art, phosphate amine salts are usually used as lubricating oil anti-wear additives and require a relatively high dosage. The inventors of the present invention have found through continuous research that phosphate organic alkali salts with a nitrogen-containing bicyclic structure can show significant anti-wear properties at a relatively low dosage level, and can effectively improve the anti-wear performance and load-bearing capacity of lubricating oil. The phosphate ester salt does not contain metal elements, is not easy to produce ash, and has low metal corrosion while showing excellent anti-wear properties, which is a significant improvement over the phosphate amine salt compounds of the prior art.

[0043] In the present invention, R 1 and R 2 Each is independently selected from hydrogen, hydrocarbon, substituted hydrocarbon or heteroalkyl. Preferably, R 1 and R 2 Not hydrogen at the same time.

[0044] Wherein, "hydrocarbyl" has the conventional meaning known in the art, including but not limited to straight or branched alkyl, straight or branched alkenyl, straight or branched alkynyl, cycloalkyl, cycloalkenyl, cycloalkynyl, aryl or a combination thereof. Preferably, the hydrocarbyl is a C1-C20 hydrocarbyl, including but not limited to a C1-C20 straight or branched alkyl, a C2-C20 straight or branched alkenyl, a C2-C20 straight or branched alkynyl, a C3-C20 cycloalkyl, a C3-C20 cycloalkenyl, a C3-C20 cycloalkynyl, a C6-C20 aryl or a combination thereof.

[0045] In the present invention, the "substituted hydrocarbon group" refers to a group obtained by directly replacing one or more hydrogen atoms in a hydrocarbon molecule with a substituent, and the substituent includes but is not limited to at least one of a fluorine atom, a chlorine atom, a bromine atom, a hydroxyl group, a mercapto group, an alkoxy group and an alkylthio group.

[0046] In the present invention, the "heteroalkyl" refers to a group obtained by directly replacing one or more carbon atoms in the alkyl molecular structure (excluding the ends of the main chain or any side chain in the alkyl molecular structure) with heteroatoms. It is understood that from the perspective of structural stability, when there are multiple heteroatoms, these heteroatoms are not directly bonded. In the present invention, although the number of carbon atoms in the alkyl group is reduced accordingly because the carbon atoms are replaced by heteroatoms, for the sake of simplicity, the number of carbon atoms in the alkyl group before the replacement is still used to refer to the number of carbon atoms in the heteroalkyl group.

[0047] For example, C 4 Straight chain alkyl such as (The group indicated by the arrow is at the end of the main chain) is directly replaced by a replacement group -O- to obtain -CH 2 -O-CH 2 -CH 3 or -CH 2-CH 2 -O-CH 3 , called C 4 Straight chain heteroalkyl. Alternatively, C 4 Branched chain alkyl such as (where the group indicated by the arrow is not inside the molecular structure, but at the end of the main chain and the side chain) is directly replaced by a replacement group -N< to obtain Call it C 4 Branched heteroalkyl group. According to the present invention, the heteroalkyl group includes but is not limited to a C3-C20 straight chain or branched heteroalkyl group, preferably a C3-C10 straight chain or branched heteroalkyl group.

[0048] Preferably, the heteroatom in the heteroalkyl group is at least one of O, N and S, preferably O and / or S, and more preferably S.

[0049] According to the present invention, preferably, the R 1 and R 2 Each is independently selected from a C4-C18 hydrocarbon group, a C4-C18 hydroxy-substituted hydrocarbon group or a C3-C20 heteroalkyl group, including but not limited to n-butyl, isobutyl, tert-butyl, n-hexyl, 2-ethylhexyl, n-octyl, 1-methylheptyl, 3,5,5-trimethylhexyl, n-decyl, n-dodecyl, n-tetradecyl, n-hexadecyl, n-octadecyl, 9-octadecenyl, 9,12-octadecadienyl, 12-hydroxy-9-octadecenyl, cyclohexyl, phenyl, methylphenyl or dimethylphenyl.

[0050] According to the present invention, in formula (2), r1 and r2 are each independently 0 or 1. It is understood that when r1 is 0, it means R 4 The group does not exist. In this case, R 4 The N atoms and C atoms on both sides are directly connected. Similarly, when r2 is 0, it means R 5 The group does not exist. In this case, R 5 N and X on both sides 1 The meanings of r3, r4, r5 and r6 in formula (3) and formula (4) are the same as those of r1 and r2, and will not be repeated here.

[0051] In the present invention, as long as the phosphate salt has a phosphate group and a nitrogen-containing bicyclic structure, the anti-wear performance of the lubricating oil can be improved. By controlling the size (carbon number) of the bicyclic ring, the anti-wear performance and metal corrosion resistance can be further optimized. For example, by adjusting R in formula (2) 3 , R 4 and R 5 The number of carbon atoms in the main chain of the group can control the size of the bicyclic structure in formula (2). Similarly, in the structures shown in formula (3) and formula (4), by adjusting R6 , R 7 and R 8 and R 9 , R 10 and R 11 The number of main chain carbon atoms of the group can control the size of the bicyclic structure in formula (2) and formula (3).

[0052] According to the present invention, preferably, in formula (2) to formula (4), R 3 , R 6 , R 9 Each is independently -(CH 2 ) a , wherein a is selected from 2-5.

[0053] According to the present invention, preferably, R 4 , R 7 , R 10 Each is independently -(CH 2 ) b -, where b is 1-2.

[0054] According to the present invention, preferably, R 5 , R 8 , R 11 Each is independently -(CH 2 ) c , where c is 1-3.

[0055] The ring number and stereostructure of the above-mentioned preferred nitrogen-containing organic compound can control the basicity and dispersibility of such compound in the base oil, and the nitrogen-containing organic compound with sufficiently stable chemical properties can also be selected according to the use environment.

[0056] According to the present invention, the phosphate salt can exist, be manufactured or used in the form of a single (pure) compound, or in the form of a mixture of two or more thereof (in any proportion), which does not affect the realization of the effects of the present invention.

[0057] According to the present invention, there is no particular limitation on the preparation method of the phosphate ester salt, and the phosphate ester salt can be prepared by any method known in the art.

[0058] The second aspect of the present invention provides a method for preparing the phosphate ester salt, the method comprising:

[0059] The acidic phosphate having the structure shown in formula (5) is contacted with a nitrogen-containing organic substance having a bicyclic structure to react with a phosphate salt;

[0060] Among them, R 1 and R 2 are each independently selected from hydrogen, hydrocarbyl, substituted hydrocarbyl or heteroalkyl;

[0061] The nitrogen-containing organic compound has at least one of the structures shown in formula (6), formula (7) and formula (8),

[0062] Among them, X 1 R and R' are each independently selected from hydrogen or a C1-C4 hydrocarbon group; R 3 , R 4 and R 5 Each is independently selected from a C1-C5 hydrocarbon group, and r1 and r2 are each independently 0 or 1;

[0063] Among them, R 6 , R 7 and R 8 Each is independently selected from a C1-C5 hydrocarbon group, and r3 and r4 are each independently 0 or 1;

[0064] Wherein, R" is selected from hydrogen or C1-C4 hydrocarbon group, R 9 , R 10 and R 11 r5 and r6 are each independently selected from a C1-C5 hydrocarbon group, and are each independently 0 or 1.

[0065] In the present invention, the acidic phosphate ester can be directly a commercially available product, or can be manufactured by a conventional method known in the art, and the present invention has no particular limitation thereto. In addition, the acidic phosphate ester can be used alone or in combination of two or more, as long as the structure shown in formula (5) is satisfied.

[0066] According to the present invention, preferably, in formula (5), R 1 and R 2 Not hydrogen at the same time.

[0067] Preferably, the R 1 and R 2 Each is independently selected from a C4-C18 hydrocarbon group, a C4-C18 hydroxy-substituted hydrocarbon group or a C3-C20 heteroalkyl group.

[0068] Preferably, the heteroatom in the heteroalkyl group is at least one of O, N and S, preferably O and / or S, and more preferably S.

[0069] Preferably, R 1 and R 2Each is independently selected from n-butyl, isobutyl, tert-butyl, n-hexyl, 2-ethylhexyl, n-octyl, 1-methylheptyl, 3,5,5-trimethylhexyl, n-decyl, n-dodecyl, n-tetradecyl, n-hexadecyl, n-octadecyl, 9-octadecenyl, 9,12-octadecadienyl, 12-hydroxy-9-octadecenyl, cyclohexyl, phenyl, methylphenyl or dimethylphenyl.

[0070] According to the present invention, the acidic phosphate ester includes but is not limited to mono-n-butyl phosphate (CAS: 1623-15-0), di-n-butyl phosphate (CAS: 107-66-4), mono-isobutyl phosphate (CAS: 2466-73-1), di-isobutyl phosphate (CAS: 6303-30-6), mono-tert-butyl phosphate (CAS: 2382-75-4), di-tert-butyl phosphate (CAS: 33494-81-4), mono-n-hexyl phosphate (CAS: 3900-04-7), di-n-hexyl phosphate (CAS: 3900-04-7), di-n-butyl ... mono-tert-butyl phosphate (CAS: 3900-04-7), di-n-butyl phosphate (CAS: 3900-04-7), mono-tert-butyl phosphate (CAS: 3303-30-6), mono-tert-butyl phosphate (CAS: 2382-75-4), di-tert-butyl phosphate (CAS: 33494-81-4), mono-tert-butyl phosphate (CAS: 3382-75-4), di-tert-butyl phosphate (CAS: 33494-81-4), mono-tert-butyl phosphate (CAS: 3900-0 13-8), monophenyl phosphate (CAS: 701-64-4), diphenyl phosphate (CAS: 838-85-7), benzyl phosphate (CAS: 1623-07-0), dibenzyl phosphate (CAS: 1623-08-1), mono(methylphenyl) phosphate, di(methylphenyl) phosphate, mono-n-octyl phosphate (CAS: 3991-73-9), di-n-octyl phosphate (CAS: 3115-39-7), mono(2-ethylhexyl) phosphate (CAS: 1070-03-7), di(2- Phosphate (CAS: 298-07-7), mono(1-methylheptyl) phosphate (CAS: 10353-73-8), di(1-methylheptyl) phosphate (CAS: 77076-28-9), mono(3,5,5-trimethylhexyl) phosphate (CAS: 85006-34-4), di(3,5,5-trimethylhexyl) phosphate (CAS: 7153-98-2), mono-n-decyl phosphate (CAS: 3921-30-0), di-n-decyl phosphate (CAS: 7795-87-1) , monolauryl phosphate, dilauryl phosphate, monomyristyl phosphate, dimyristyl phosphate, mono(hexadecyl) phosphate, di(hexadecyl) phosphate, monostearyl phosphate, distearyl phosphate, mono(9-octadecenyl) phosphate, di(9-octadecenyl) phosphate, mono(9,12-octadecadienyl) phosphate, di(9,12-octadecadienyl) phosphate, mono(12-hydroxy-9-octadecenyl) phosphate and di(12-hydroxy-9-octadecenyl) phosphate or at least one of the isomers of the above compounds.

[0071] The present invention has no particular limitation on the source of the nitrogen-containing organic compound having a bicyclic structure, and commercially available products can be used directly, or they can be prepared by conventional methods known in the art. The nitrogen-containing organic compound can be used alone or in combination of two or more, as long as it satisfies at least one of the structures shown in formula (6), formula (7) and formula (8).

[0072] According to the present invention, preferably, in formula (6) to formula (8), R 3 , R 6 , R 9 Each is independently -(CH 2 ) a , wherein a is selected from 2-5.

[0073] Preferably, R 4 , R 7 , R 10 Each is independently -(CH 2 ) b -, where b is 1-2.

[0074] Preferably, R 5 , R 8 , R 11 Each is independently -(CH 2 ) c , where c is 1-3.

[0075] According to the present invention, the nitrogen-containing organic matter includes but is not limited to 1,4-diazabicyclo[2.2.2]octane (CAS: 280-57-9), 1-azabicyclo[2.2.2]octane (quinuclidine, CAS: 100-76-5), 1,5-diazabicyclo[4.3.0]-5-nonene (CAS: 3001-72-7), 1,8-diazabicyclo[5.4.0]undec-7-ene (abbreviated as DBU, CAS: 6674-22-2), and any proportion of the above compounds.

[0076] In the present invention, preferably, the molar ratio of the acidic phosphate to the nitrogen-containing organic matter is 1:0.1-10, preferably 1:0.4-5, and more preferably 1:0.5-2.

[0077] The present invention has a wide range of selection for the reaction temperature of the phosphate salt. Preferably, the reaction temperature is 0-200°C, preferably 20-150°C, and more preferably 60-120°C. The present invention has no special requirements for the reaction time. In order to ensure sufficient reaction, preferably, the reaction time is 0.1-24h, preferably 0.5-12h, and more preferably 1-5h.

[0078] The present invention has no particular limitation on the reaction pressure and atmosphere for the reaction of the phosphate ester salt, and the reaction can be carried out under normal pressure and air conditions.

[0079] According to the present invention, the phosphate salt reaction can be carried out in the presence of a solvent or in the absence of a solvent, and the reaction can be achieved. Preferably, the phosphate salt reaction is carried out in the presence of a solvent, for example, the acidic phosphate and the nitrogen-containing organic matter are added to a reactor containing a solvent for contact, or the acidic phosphate and the nitrogen-containing organic matter are dissolved in a solvent respectively, and then both are added to a reactor for the phosphate salt reaction. The present invention has no special requirements for the reactor, as long as the reaction conditions can be controlled within the above range, conventional reaction devices in the art can be applied to the present invention.

[0080] The present invention has no particular requirements for the specific operating conditions for adding the above-mentioned reactants to the reactor, and can be carried out in a conventional operating manner in the art. Preferably, the reactants are slowly added in batches or dropwise to the reactor, and the temperature is controlled within the above-mentioned reaction temperature range.

[0081] The present invention has no particular limitation on the order of adding the reaction raw materials, and they can be added in any order.

[0082] Preferably, the solvent is selected from at least one of C6-C10 alkanes, C6-C20 aromatic hydrocarbons, C5-C10 fatty ethers, C2-C20 halogenated hydrocarbons and C3-C10 amides. The C6-C10 alkanes include but are not limited to at least one of n-hexane, cyclohexane and petroleum ether; the C6-C20 aromatic hydrocarbons include but are not limited to at least one of benzene, toluene, xylene and isopropylbenzene; the C2-C20 halogenated hydrocarbons include but are not limited to at least one of dichloromethane, carbon tetrachloride, chlorobenzene and 1,2-dichlorobenzene; the C5-C10 fatty ethers include but are not limited to at least one of methyl tert-butyl ether, 1,2-dimethoxyethane, ethylene glycol diethyl ether and 1,4-dioxane; the C3-C10 amides include but are not limited to at least one of dimethylformamide, dimethylacetamide and N-methylpyrrolidone.

[0083] According to the present invention, preferably, the mass ratio of the total mass of the acidic phosphate and the nitrogen-containing organic matter to the solvent is 1:0.5-10, preferably 1:0.5-5, and more preferably 1:0.8-3.

[0084] According to the present invention, the solvent may be used alone or in combination of two or more. Preferably, the preparation method further comprises recovering the solvent after the reaction and recycling it in the same reaction. For example, the solvent may be recovered by vacuum distillation.

[0085] According to the present invention, in the preparation method of the phosphate salt, the obtained reaction product can be a single phosphate salt or a mixture containing multiple phosphate salts. These reaction products are all expected by the present invention, and the phosphate salts all have the structural unit shown in formula (1), and at least one of the structural units shown in formula (2), formula (3) and formula (4), and the difference in their specific existence forms does not affect the realization of the effect of the present invention. Therefore, in the context of this specification, these reaction products are collectively referred to as the phosphate salts of the present invention without distinction.

[0086] Therefore, in the present invention, the product obtained by the reaction of the phosphate ester salt may be purified or not. In order to further improve the performance of the phosphate ester salt, preferably, the preparation method further comprises: purifying the product obtained by the reaction of the phosphate ester salt. The phosphate ester salt of a specific structure is separated from the product obtained by the reaction of the phosphate ester salt by the purification.

[0087] The purification may be carried out by any conventional purification or separation method in the art, and the present invention has no particular limitation thereto. For example, the reaction product may be purified by column chromatography or preparative chromatography.

[0088] The present invention will be described in detail below through examples.

[0089] In the following examples and comparative examples, unless otherwise specified, the raw materials used were commercially available.

[0090] Example 1

[0091] In a 250mL three-necked flask equipped with a magnetic stirrer, a thermometer, a condenser and a dropping funnel, add 5.59 grams (49.84 mmol) of 1,4-diazabicyclo[2.2.2]octane and 44.15 grams of 1,2-dimethoxyethane, and stir rapidly to dissolve at room temperature; 25.02 grams (100.00 mmol) of diphenyl phosphate is dissolved in 49.09 grams of 1,2-dimethoxyethane and then slowly dripped into the three-necked flask; the temperature is raised to 85°C, and the temperature is controlled to reflux between 80-85°C for 4.5 hours. After the reaction is completed, the solvent is evaporated by reduced pressure distillation to obtain 30.48 grams of a white waxy product. The product is recorded as S1. The product structure was characterized by chromatography-mass spectrometry, and the molecular weight of the main product was measured to be 350.12. According to the analysis, the structure of the main product in S1 is shown as follows:

[0092]

[0093] Example 2

[0094] In a 250mL three-necked flask equipped with a magnetic stirrer, a thermometer, a condenser and a dropping funnel, add 5.60 grams (49.92 mmol) of 1,4-diazabicyclo[2.2.2]octane and 46.02 grams of 1,2-dimethoxyethane, and stir and dissolve rapidly at room temperature; 32.21 grams (99.90 mmol) of di(2-ethylhexyl) phosphate is slowly dripped into the three-necked flask, the temperature is raised to 85°C, and the temperature is controlled to reflux at 80-85°C for 4 hours. After the reaction is completed, the solvent is evaporated by reduced pressure distillation to obtain 37.32 grams of a white waxy product. The product is recorded as S2. The product structure was characterized by chromatography-mass spectrometry, and the molecular weight of the main product was measured to be 434.38. According to the analysis, the structure of the main product in S2 is shown as follows:

[0095]

[0096] Example 3

[0097] In a 250mL three-necked flask equipped with a magnetic stirrer, a thermometer, a condenser and a dropping funnel, add 5.61 grams (50.13 mmol) of 1,4-diazabicyclo[2.2.2]octane and 45.52 grams of 1,2-dimethoxyethane, and stir and dissolve rapidly at room temperature; 21.04 grams (100.01 mmol) of di-n-butyl phosphate are slowly dripped into the three-necked flask, the temperature is raised to 85°C, and the temperature is controlled to reflux at 80-85°C for 4 hours. After the reaction is completed, the solvent is evaporated by reduced pressure distillation to obtain 26.06 grams of a slightly yellow, clear, transparent oily liquid product. The product is recorded as S3. The product structure was characterized by chromatography-mass spectrometry, and the molecular weight of the main product was measured to be 321.99. According to the analysis, the structure of the main product in S3 is shown as follows:

[0098]

[0099] Example 4

[0100] In a 250mL three-necked flask equipped with a magnetic stirrer, a thermometer, a condenser and a dropping funnel, add 12.50 grams (49.96 mmol) of diphenyl phosphate and 25.36 grams of 1,2-dimethoxyethane, and stir rapidly to dissolve at room temperature; 3.84 grams (25.22 mmol) of 1,8-diazabicyclo[5.4.0]undec-7-ene are slowly dripped into the three-necked flask, the temperature is raised to 95°C, and the temperature is controlled to reflux between 85-90°C for 4.5 hours. After the reaction is completed, the solvent is evaporated by reduced pressure distillation to obtain 16.14 grams of a slightly yellow, clear and transparent viscous product. The product is recorded as S4. The product structure was characterized by chromatography-mass spectrometry, and the molecular weight of the main product was measured to be 402.89. According to the analysis, the structure of the main product in S4 is shown as follows:

[0101]

[0102] Example 5

[0103] In a 250mL three-necked flask equipped with a magnetic stirrer, a thermometer, a condenser and a dropping funnel, add 16.17 grams (50.15 mmol) of di(2-ethylhexyl) phosphate and 19.92 grams of 60-90°C petroleum ether, and stir and dissolve at room temperature; 3.81 grams (25.03 mmol) of 1,8-diazabicyclo[5.4.0]undec-7-ene are slowly dripped into the three-necked flask, the temperature is raised to 85°C, and the temperature is controlled to reflux at 65-75°C for 4 hours. After the reaction is completed, the solvent is evaporated by reduced pressure distillation to obtain 19.92 grams of a slightly yellow, clear, transparent oily liquid product. The product is recorded as S5. The product structure was characterized by chromatography-mass spectrometry, and the molecular weight of the main product was measured to be 474.56. According to the analysis, the structure of the main product in S5 is shown as follows:

[0104]

[0105] Comparative Example 1 Diphenyl phosphate lauryl amine salt antiwear agent

[0106] Commercially available diphenyl phosphate and lauryl amine are used as raw materials. Diphenyl phosphate is dissolved in 1,2-dimethoxyethane, wherein the mass ratio of diphenyl phosphate to 1,2-dimethoxyethane is 1:2. Lauryl amine is dissolved in 60-90°C petroleum ether, wherein the mass ratio of lauryl amine to petroleum ether is 1:1. Slowly drip the lauryl amine solution into the diphenyl phosphate solution under stirring, wherein the molar ratio of diphenyl phosphate to lauryl amine is 1:1. Heat to 85°C, control the temperature at 70-80°C and reflux for 4 hours. After the reaction is completed, the solvent is evaporated to obtain a product recorded as DS1, wherein the main component is diphenyl phosphate lauryl amine salt, and the structure is shown below:

[0107]

[0108] Comparative Example 2: Di(2-ethylhexyl) phosphate di-n-hexylamine salt antiwear agent

[0109] The raw materials used are commercially available di(2-ethylhexyl) phosphate and di-n-hexylamine. Dissolve di(2-ethylhexyl) phosphate in 60-90°C petroleum ether, wherein the mass ratio of di(2-ethylhexyl) phosphate to 60-90°C petroleum ether is 1:1. Slowly drip di-n-hexylamine into the di(2-ethylhexyl) phosphate solution under stirring, wherein the molar ratio of di(2-ethylhexyl) phosphate to di-n-hexylamine is 1:1. Heat to 85°C, control the temperature at 75-80°C and reflux for 4 hours. After the reaction is completed, evaporate the solvent and obtain a product recorded as DS2, wherein the main component is di(2-ethylhexyl) phosphate di-n-hexylamine salt, and the structure is shown below:

[0110]

[0111] Comparative Example 3: Di-n-butyl phosphate di-n-hexylamine salt anti-wear agent

[0112] The raw materials used are commercially available di-n-butyl phosphate and di-n-hexylamine. Di-n-butyl phosphate is dissolved in 60-90°C petroleum ether, wherein the mass ratio of di-n-butyl phosphate to 60-90°C petroleum ether is 1:1. Di-n-hexylamine is slowly dripped into the di-n-butyl phosphate solution under stirring, wherein the molar ratio of di-n-butyl phosphate to di-n-hexylamine is 1:1. Heat to 85°C, control the temperature at 75-80°C and reflux for 4 hours. After the reaction is completed, the solvent is evaporated and the product is recorded as DS3, wherein the main component is di-n-butyl phosphate di-n-hexylamine salt, and the structure is shown below:

[0113]

[0114] Comparative Example 4 selected the product Irgalube 349 from BASF.

[0115] Examples I-1 to I-5 and Comparative Examples DI-1 to DI-4 of Electric Vehicle Transmission Lubricant Compositions

[0116] According to the formulation composition in Table 1, examples I-1 to I-5 and comparative examples DI-1 to DI-4 of electric vehicle gearbox lubricant compositions were prepared respectively. The main additives and base oils used therein are from the following sources:

[0117] Diisobutylene succinimide T154A, dispersibility SDT ≥ 55, produced by Yangzi Petrochemical Company;

[0118] Non-dispersible PMA viscosity index improver Viscoplex 8-310, 100℃ kinematic viscosity 1250mm 2 / s, produced by Evonik Degussa;

[0119] Amine antioxidant T534, nitrogen content> 3.0%, kinematic viscosity at 100℃ 10.0mm 2 / s, produced by Beijing Xingpu Fine Chemical Technology Development Co., Ltd.;

[0120] Phenolic antioxidant T512, 100℃ kinematic viscosity 7.0mm 2 / s, produced by Beijing Xingpu Fine Chemical Technology Development Co., Ltd.;

[0121] Benzotriazole derivative T551, 100℃ kinematic viscosity, 12.5mm 2 / s, produced by Zibo Huihua Petroleum Additives Company;

[0122] Product Irgalube 349, viscosity at 40°C is 2200 mPa·s, BASF;

[0123] Type III hydrogenated base oil, kinematic viscosity at 100°C 4.45 mm 2 / s, viscosity index 125, produced by Maoming Petrochemical.

[0124] Table 1 Lubricating oil composition for electric vehicle gearbox

[0125]

[0126] The kinematic viscosity, load-bearing performance, and copper corrosion test performance of the embodiments and comparative examples of the electric vehicle gearbox lubricating oil composition were evaluated respectively.

[0127] The main test methods are as follows:

[0128] The kinematic viscosity determination method is GB / T 265 standard method;

[0129] Four-ball wear and extreme pressure test, using GB / T 3142 standard method;

[0130] Falex extreme pressure performance test adopts SH / T 0187 standard method;

[0131] FZG gear test, A10 / 16.6R / 90°C, using ISO 14635-2 standard method;

[0132] The copper corrosion test adopts GB / T 5096 standard method, and the test conditions are 150℃, 192h;

[0133] The measurement results are shown in Table 2.

[0134] Table 2 Evaluation test results of electric vehicle gearbox lubricant

[0135]

[0136] It can be seen from the above test results that the lubricating oil composition of the present invention can meet the requirement of low viscosity of oil products, and at the same time has high load-bearing performance and excellent copper corrosion resistance.

[0137] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. An electric vehicle gearbox lubricating oil composition comprising the following components: (A) ashless dispersant, accounting for 1.0% to 5.0% of the total weight of the composition; (B) a viscosity index improver, accounting for 0.5% to 5.0% of the total mass of the composition; (C) an antioxidant, accounting for 0.1% to 3.0% of the total weight of the composition; (D) metal deactivator, accounting for 0.01% to 0.3% of the total mass of the composition; (E) phosphate salt, accounting for 0.2% to 2.0% of the total weight of the composition; (F) base oil, constituting the main component of the composition; The phosphate salt comprises a structural unit represented by formula (1) and at least one of the structural units represented by formula (2), formula (3) and formula (4), in, R1 and R2 are each independently selected from hydrogen, hydrocarbyl, substituted hydrocarbyl or heteroalkyl; wherein X1 is selected from nitrogen or methine, R and R' are each independently selected from hydrogen or a C1-C4 hydrocarbon group; R3, R4 and R5 are each independently selected from a C1-C5 hydrocarbon group, and r1 and r2 are each independently 0 or 1; wherein R6, R7 and R8 are each independently selected from a C1-C5 hydrocarbon group, and r3 and r4 are each independently 0 or 1; Wherein, R" is selected from hydrogen or C1-C4 hydrocarbon group, R9, R 10 and R 11 r5 and r6 are each independently selected from a C1-C5 hydrocarbon group, and are each independently 0 or 1.

2. The lubricating oil composition according to claim 1, characterized in that In formula (1), R1 and R2 are not hydrogen at the same time; Preferably, R1 and R2 are each independently selected from a C4-C18 hydrocarbon group, a C4-C18 hydroxy-substituted hydrocarbon group or a C3-C20 heteroalkyl group; Preferably, the heteroatom in the heteroalkyl group is at least one of O, N and S, preferably O and / or S, and more preferably S.

3. The lubricating oil composition according to claim 2, characterized in that R1 and R2 are each independently selected from n-butyl, isobutyl, tert-butyl, n-hexyl, 2-ethylhexyl, n-octyl, 1-methylheptyl, 3,5,5-trimethylhexyl, n-decyl, n-dodecyl, n-tetradecyl, n-hexadecyl, n-octadecyl, 9-octadecenyl, 9,12-octadecadienyl, 12-hydroxy-9-octadecenyl, cyclohexyl, phenyl, benzyl, methylphenyl or dimethylphenyl.

4. The lubricating oil composition according to claim 1, characterized in that In formula (2) to formula (4), R3, R6, and R9 are each independently -(CH2) a -, wherein a is selected from 2-5; and / or, R4, R7, R 10 Each independently is -(CH2) b -, where b is 1-2; and / or, R5, R8, R 11 Each independently is -(CH2) c -, where c is 1-3.

5. The lubricating oil composition according to claim 1, characterized in that: The preparation method of the phosphate salt comprises: The acidic phosphate having the structure shown in formula (5) is contacted with a nitrogen-containing organic substance having a bicyclic structure to react with a phosphate salt; wherein R1 and R2 are each independently selected from hydrogen, a hydrocarbon group, a substituted hydrocarbon group or a heteroalkyl group; The nitrogen-containing organic compound has at least one of the structures shown in formula (6), formula (7) and formula (8), wherein X1 is selected from nitrogen or methine, R and R' are each independently selected from hydrogen or a C1-C4 hydrocarbon group; R3, R4 and R5 are each independently selected from a C1-C5 hydrocarbon group, and r1 and r2 are each independently 0 or 1; wherein R6, R7 and R8 are each independently selected from a C1-C5 hydrocarbon group, and r3 and r4 are each independently 0 or 1; Wherein, R" is selected from hydrogen or C1-C4 hydrocarbon group, R9, R 10 and R 11 r5 and r6 are each independently selected from a C1-C5 hydrocarbon group, and are each independently 0 or 1.

6. The lubricating oil composition according to claim 5, characterized in that In formula (5), R1 and R2 are not hydrogen at the same time; Preferably, R1 and R2 are each independently selected from a C4-C18 hydrocarbon group, a C4-C18 hydroxy-substituted hydrocarbon group or a C3-C20 heteroalkyl group; Preferably, the heteroatom in the heteroalkyl group is at least one of O, N and S, preferably O and / or S, and more preferably S; Preferably, R1 and R2 are each independently selected from n-butyl, isobutyl, tert-butyl, n-hexyl, 2-ethylhexyl, n-octyl, 1-methylheptyl, 3,5,5-trimethylhexyl, n-decyl, n-dodecyl, n-tetradecyl, n-hexadecyl, n-octadecyl, 9-octadecenyl, 9,12-octadecadienyl, 12-hydroxy-9-octadecenyl, cyclohexyl, phenyl, benzyl, methylphenyl or dimethylphenyl.

7. The lubricating oil composition according to claim 5, characterized in that In formula (6) to formula (8), R3, R6, and R9 are each independently -(CH2) a -, wherein a is selected from 2-5; and / or, R4, R7, R 10 Each independently is -(CH2) b -, where b is 1-2; and / or, R5, R8, R 11 Each independently is -(CH2) c -, where c is 1-3.

8. The lubricating oil composition according to claim 5, characterized in that The molar ratio of the acidic phosphate to the nitrogen-containing organic matter is 1:0.1-10, preferably 1:0.4-5, more preferably 1:0.5-2; Preferably, the conditions for the reaction of the phosphate salt include: reaction temperature of 0-200°C, preferably 20-150°C, more preferably 60-120°C, reaction time of 0.1-24h, preferably 0.5-12h, more preferably 1-5h.

9. The lubricating oil composition according to any one of claims 1 to 8, characterized in that: The ashless dispersant is selected from polyisobutylene succinimide and / or boronated polyisobutylene succinimide; the viscosity index improver is selected from polymethacrylate and / or polyisobutylene; the antioxidant is selected from one or more of alkylated diphenylamine, N-phenyl-α-naphthylamine, shielded phenol and phenol ester; the metal deactivator is selected from one or more of alkylaminomethylenebenzotriazole, benzotriazole dialkylamine formaldehyde condensate, thiadiazole polysulfide and thiadiazole alkyl mercaptan hydroperoxide condensate; the base oil is selected from one or more of API I, II, III, IV and V base oils.

10. The method for preparing the electric vehicle gearbox lubricating oil composition according to any one of claims 1 to 9, comprising the step of mixing various additives therein with the base oil.

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