Electric vehicle gearbox lubricating oil composition

Abstract

The present invention provides an electric vehicle gearbox lubricating oil composition, comprising the following components: (A) an aromatic amine type ashless dispersant; (B) a viscosity index improver; (C) an extreme pressure anti-wear agent; (D) an antioxidant; (E) a metal deactivator; and (F) a base oil; wherein the preparation method of the aromatic amine type ashless dispersant comprises: (1) allowing isatoic anhydride to undergo a ring-opening reaction with polyene polyamine; (2) in the presence of a diluent oil, allowing the ring-opening reaction product obtained in step (1) to undergo an imidization reaction with polyisobutylene succinic anhydride, and collecting the reaction product. The electric vehicle gearbox lubricating oil composition of the present invention has excellent electrical insulation performance, cooling performance, and copper corrosion resistance.

Description

Technical Field

[0001] The invention relates to a lubricating oil composition, in particular to a lubricating oil composition for a gearbox of an electric vehicle. Background Art

[0002] The biggest difference between electric vehicles and traditional fuel vehicles is that electric motors are used to replace engines, so the performance requirements of electric vehicle lubricants are different from those of traditional oils. The transmission structure of electric vehicles is more compact, and the motor directly drives the gearbox, with a speed of generally 12,000 to 20,000 r / min. At the same time, due to the high speed and high load in the gearbox, the operating conditions are harsh and the oil working temperature is high, so the high-temperature oxidation stability, anti-wear and friction reduction, and copper corrosion inhibition of the oil are more stringent.

[0003] The structural characteristics of electric vehicles also require that the oil has good electrical insulation and cooling properties. Due to the high operating temperature of electric vehicle oil, high-temperature oxidation of the oil will lead to insufficient electrical insulation and poor heat dissipation of the oil after deterioration. At the same time, since the motor structure contains a large number of copper components, there are also strict requirements on the corrosion resistance of electric vehicle oil, especially the poor corrosion resistance of the oil after aging.

[0004] At present, there have been many research reports on electric vehicle lubricant compositions at home and abroad. CN107828481A provides an electric vehicle transmission oil composition, which contains a special compound for transmission oil and has good shear stability, but does not examine the electrical insulation and copper corrosion resistance of the oil. CN105087113A provides an electric vehicle transmission system composition, which examines the electrical insulation performance of the oil before and after aging, but does not take into account the copper corrosion resistance of the oil after aging.

[0005] Ashless dispersants have a very important influence on the electrical insulation of the composition in the fully formulated electric vehicle transmission oil. Most of the existing technologies use traditional succinimide (succinamide) type ashless dispersants, but they cannot balance the electrical insulation performance of the oil and the copper corrosion resistance of the oil after aging. Therefore, it is very necessary to develop a new type of ashless dispersant to improve the electrical insulation of the oil and balance the comprehensive performance of the electrical insulation, cooling and copper corrosion resistance of the oil after oxidation and degradation. Summary of the invention

[0006] The invention provides a lubricating oil composition for an electric vehicle gearbox.

[0007] The electric vehicle gearbox lubricating oil composition of the present invention comprises the following components:

[0008] (A) an aromatic amine type ashless dispersant, accounting for 1% to 5% of the total weight of the composition;

[0009] (B) viscosity index improver, accounting for 0.5% to 3% of the total mass of the composition;

[0010] (C) extreme pressure anti-wear agent, accounting for 0.1% to 2% of the total mass of the composition;

[0011] (D) an antioxidant, accounting for 0.5% to 3% of the total weight of the composition;

[0012] (E) metal deactivator, accounting for 0.01% to 0.2% of the total mass of the composition;

[0013] (F) base oil, constituting the main component of the composition;

[0014] The preparation method of the aromatic amine type ashless dispersant comprises:

[0015] (1) causing isocyanic anhydride to undergo a ring-opening reaction with polyene polyamine;

[0016] (2) In the presence of diluent oil, the ring-opening reaction product obtained in step (1) is subjected to an imidization reaction with polyisobutylene succinic anhydride, and the reaction product is collected.

[0017] According to the present invention, in step (1), the temperature of the ring-opening reaction is 90 to 220° C., preferably 110 to 160° C.; the time of the ring-opening reaction is 1 to 10 hours, preferably 1 to 6 hours; the molar ratio between the isatoic anhydride and the polyene polyamine is 0.1 to 1:1, preferably 0.3 to 1:1.

[0018] According to the present invention, in step (1), the ring-opening reaction is carried out under an inert atmosphere, and the inert atmosphere is preferably provided by nitrogen.

[0019] According to the present invention, after the ring-opening reaction in step (1) is completed, no special treatment is required and the product can be directly used in the imidization reaction in step (2).

[0020] According to the present invention, in step (2), the molar ratio of the polyisobutylene succinic anhydride to the polyene polyamine in step (1) is 0.5 to 3:1, preferably 1 to 2:1; the temperature of the imidization reaction is 80 to 180°C, preferably 90 to 150°C; and the reaction time is 1 to 10 hours, preferably 1 to 4 hours.

[0021] According to the present invention, in step (2), the amount of the diluent oil is 25% to 300% of the mass of the polyisobutylene succinic anhydride, preferably 25% to 200%.

[0022] According to the present invention, in step (2), there is no special requirement for the order of adding the materials. However, the inventors of the present invention have found through in-depth research that in step (2), controlling the order of adding the materials can obtain better technical effects. For example, when the polyisobutylene succinic anhydride is added to the mixture of the ring-opening reaction product obtained in step (1) and the diluent oil, the obtained reaction product has better dispersibility. When the molar ratio of isatoic anhydride to polyene polyamine is relatively small, in addition to controlling the order of adding the materials, further controlling the speed of adding the materials can further improve the dispersibility of the obtained reaction product, especially the sludge dispersibility.

[0023] Therefore, preferably, in step (2), the polyisobutylene succinic anhydride is added to the mixture of the ring-opening reaction product obtained in step (1) and the diluent oil, wherein the addition rate of the polyisobutylene succinic anhydride is 0.01 to 0.05 mol / min relative to 1 mol of the polyene polyamine used in step (1). It can be understood that the temperature of the imidization reaction system can generally be kept at about 90 to 150° C. by satisfying the above addition rate, and the dropwise addition can generally be completed in 0.5 to 2 hours.

[0024] According to the present invention, there is no particular limitation on the post-treatment of step (2). For example, the post-treatment can be carried out according to the following steps: vacuum dehydrating the material after the reaction in step (2) at 100 to 160° C., adding a filter aid (such as diatomaceous earth) for adsorption treatment, and then subjecting the mixture to solid-liquid separation (such as filtration) to obtain the aromatic amine-type ashless dispersant with dispersibility of the present invention.

[0025] According to the present invention, the nitrogen content of the prepared aromatic amine type ashless dispersant is 0.8% to 5% (mass fraction).

[0026] According to the present invention, the polyisobutylene succinic anhydride can be obtained commercially or can be prepared in-house. The number average molecular weight of the polyisobutylene in the polyisobutylene succinic anhydride is 800 to 2500 g / mol.

[0027] According to some embodiments of the present invention, the degree of substitution of the polyisobutylene succinic anhydride is 0.9 to 1.3.

[0028] According to some embodiments of the present invention, the structural formula of the polyene polyamine is H2N(CH2CH2NH) n H, wherein n is an integer of 1 to 4. Preferably, the polyene polyamine is selected from one or more of triethylenetetramine, tetraethylenepentamine and pentaethylenehexamine.

[0029] The present invention has no particular limitation on the type of the diluent oil. For example, the diluent oil can be an oil with lubricating viscosity selected from mineral base oil and / or synthetic base oil. Preferably, the diluent oil is 150SN and / or 32# white oil.

[0030] 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.

[0031] According to the present invention, the extreme pressure anti-wear agent can be selected from one or more of phosphate esters, thiophosphates and phosphate amine salts, for example, one or more of tricresyl phosphate, di-n-butyl phosphite, dialkyl dithiophosphate and isooctyl phosphate octadecylamine salt can be selected. Common trade names include T306, T307, T308, etc.

[0032] 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, N-phenyl-α-naphthylamine, 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.

[0033] According to the present invention, the metal deactivator can be selected from one or more of benzotriazole derivatives, thiazole derivatives and thiadiazole derivatives, for example, one or more of alkylaminomethylenebenzotriazole, benzotriazole dialkylamine formaldehyde condensate, thiadiazole polysulfide and thiadiazole alkylthiol hydrogen peroxide condensate can be selected. Common trade names include T551, T561, etc.

[0034] 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.

[0035] The electric vehicle gearbox lubricating oil composition of the present invention has excellent electrical insulation performance, cooling performance and copper corrosion resistance.

[0036] The present invention measures the volume resistivity of new oil and aged oil at 80°C according to the GB / T5654 standard method. The measurement results show that the volume resistivity of the new oil of the lubricating oil composition of the present invention at 80°C is within 5×10 7 Ω·m or more, the volume resistivity of the oil after aging is 1×10 7 Ω·m or more.

[0037] The aging method of the new oil in the present invention is a DKA oxidation test, using the CEC L-48-00 standard method, with the conditions of 170° C., 192 hours, and 83 cc / min of air.

[0038] The present invention measures the copper corrosion resistance of the aged composition according to the GB / T 5096 standard method. The copper corrosion resistance test conditions are 150° C., 192 hours, and the copper content in the oil after oxidation degradation is less than 200 ppm. DETAILED DESCRIPTION

[0039] The present invention is further described below by way of examples, but they are not intended to limit the present invention.

[0040] Unless otherwise specified, all reagents used in the present invention are analytically pure and commercially available.

[0041] The saponification value was analyzed and determined according to SY2604-77.

[0042] The nitrogen content is analyzed and determined in accordance with SH / T0656-2017.

[0043] The molecular weight (Mn, Mw, and Mw / Mn) was analyzed and determined according to SH / T0108-92, and the unit is g / mol.

[0044] Degree of substitution X = (Mn*saponification value) / (112200-96*saponification value), wherein Mn is the number average molecular weight of polyisobutylene.

[0045] The main raw materials used are as follows:

[0046] Triethylenetetramine, CP, Sinopharm Reagent Co., Ltd.;

[0047] Tetraethylenepentamine, CP, Sinopharm Reagent Co., Ltd.;

[0048] 150SN base oil, Shanghai Gaoqiao Petrochemical Co., Ltd.;

[0049] Isatoic anhydride, analytical grade; Inokai Technology Co., Ltd.;

[0050] Polyisobutylene PIB1000, M n =1000, α-double bond content>75%, purchased from Yangzi Petrochemical-BASF Co., Ltd.;

[0051] Non-dispersible PMA viscosity index improver, Viscoplex 8-219, kinematic viscosity 800mm at 100℃ 2 / s, produced by Evonik Degussa (China) Investment Co., Ltd.;

[0052] Diisobutylene succinimide T154A, dispersibility SDT ≥ 55, produced by Yangzi Petrochemical Company;

[0053] 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.;

[0054] Tricresol phosphate T306, acid value less than 0.1 mg KOH / g, produced by Zibo Huihua Petrochemical Company;

[0055] Benzotriazole derivative T551, 100℃ kinematic viscosity, 12.5mm 2 / s, produced by Zibo Huihua Petrochemical Company;

[0056] Type III hydrogenated base oil, kinematic viscosity at 100°C 4.45 mm 2 / s, viscosity index 125, produced by Maoming Petrochemical.

[0057] Example 1

[0058] Under nitrogen protection, 4.22 g (0.022 mol) of tetraethylenepentamine and 2.87 g (0.0176 mol) of isocyanic anhydride were added to a four-necked flask, the system was premixed at 40 ° C for 0.5 h under stirring, the temperature was raised to 120 ° C and the ring-opening reaction was continued for 10 h, 100 g (0.044 mol) of polyisobutylene succinic anhydride (prepared according to the method described in Example 3 of CN1315317A, wherein the number average molecular weight of the polyisobutylene group is M n =2300, the saponification value of the obtained polyisobutylene succinic anhydride =60 mgKOH / g, the degree of substitution X =1.3) and 100 g of 150SN base oil were mixed and added to the reaction product (ring-opening reaction product) of isatoic anhydride and tetraethylenepentamine at a rate of 0.01 mol / min, then the temperature was raised to 150°C, the acylation reaction was continued for 1.5 h, and then vacuum dehydration was carried out at 150°C for 3 h, adsorption treatment was carried out with diatomaceous earth, and the aromatic amine type ashless dispersant of the present invention was obtained after filtration, and the nitrogen content of the aromatic amine type ashless dispersant was 1.07% by weight.

[0059] Example 2

[0060] Under nitrogen protection, 13.84 g (0.073 mol) of tetraethylenepentamine and 5.95 g (0.0365 mol) of isocyanic anhydride were added to a four-necked flask, the system was premixed at 40 ° C for 0.1 h under stirring, the temperature was raised to 200 ° C for further ring-opening reaction for 1 h, 100 g (0.073 mol) of polyisobutylene succinic anhydride (prepared according to the method described in Example 2 of CN1315317A, wherein the number average molecular weight of the polyisobutylene group is M n =1300, the saponification value of the obtained polyisobutylene succinic anhydride =86 mgKOH / g, the degree of substitution X =1.07) and 50g of 150SN base oil were mixed and added to the reaction product of isatoic anhydride and tetraethylenepentamine (ring-opening reaction product) at a rate of 0.05 mol / min, then the temperature was raised to 120°C, the acylation reaction was continued for 3h, and then vacuum dehydration was carried out at 120°C for 3h, adsorption treatment was carried out with diatomaceous earth, and the aromatic amine type ashless dispersant of the present invention was obtained after filtration, and the nitrogen content of the aromatic amine type ashless dispersant was 3.61% by weight.

[0061] Example 3

[0062] Under nitrogen protection, 9.58 g (0.066 mol) of triethylenetetramine and 1.08 g (0.0066 mol) of isocyanic anhydride were added to a four-necked flask, the system was premixed at 40°C for 0.4 h under stirring, the temperature was raised to 160°C for further ring-opening reaction for 3 h, 100 g (0.088 mol) of polyisobutylene succinic anhydride (prepared according to the method described in Example 1 of CN1315317A, wherein the number average molecular weight of the polyisobutylene group is Mn=1000, the obtained polyisobutylene succinic anhydride was added to the flask. The saponification value of butene succinic anhydride = 93 mgKOH / g, degree of substitution X = 0.9) and 75 g of 150SN base oil were mixed and added to the reaction product (ring-opening reaction product) of isatoic anhydride and triethylenetetramine at a rate of 0.01 mol / min, then the temperature was raised to 90° C., the acylation reaction was continued for 4 hours, and then vacuum dehydration was carried out at 150° C. for 3 hours, adsorption treatment was carried out with diatomaceous earth, and the aromatic amine type ashless dispersant of the present invention was obtained after filtration, and the nitrogen content of the aromatic amine type ashless dispersant was 2.61% by weight.

[0063] Example 4

[0064] The process was carried out in the same manner as in Example 1, except that the molar amount of isatoic anhydride was changed to 0.044 mol.

[0065] Example 5

[0066] 100g (0.1mol) of highly active polyisobutylene PIB1000 (Mn=1000, α-double bond content>75%, purchased from Yangzi Petrochemical-BASF Co., Ltd.) was added to a stirred reactor, and after nitrogen replacement, 9.81g (0.1mol) of maleic anhydride was added at a molar ratio of polyisobutylene to maleic anhydride of 1:1. After heating to 240°C for reaction for 6h, the temperature was lowered and purged with nitrogen at 230°C for 3h until the content of free maleic anhydride in the material was 0.64% by weight.

[0067] (1) Under nitrogen protection, 4.22 g (0.022 mol) of tetraethylenepentamine and 2.87 g (0.0176 mol) of isocyanic anhydride were added to a four-necked flask, the system was premixed at 40° C. under stirring for 0.5 h, and the temperature was raised to 120° C. to continue the ring-opening reaction for 10 h;

[0068] (2) 0.044 mol of the obtained polyisobutylene succinic anhydride (saponification value = 94 mgKOH / g) was taken, the temperature of which was maintained at 230° C., and it was added to a mixture of 100 g of 150SN base oil and the ring-opening product obtained in step (1) at a rate of 0.02 mol / min within 2 hours. The addition of polyisobutylene succinic anhydride maintained the system temperature at 150° C. and carried out acylation reaction for 1.5 hours, and then vacuum dehydration was carried out at 150° C. for 3 hours, adsorption treatment was carried out with diatomaceous earth, and after filtration, the aromatic amine type ashless dispersant of the present invention was obtained, and the nitrogen content of the aromatic amine type ashless dispersant was 0.98% by weight.

[0069] Comparative Example 1

[0070] The commercial T161 ashless dispersant was used as a comparative dispersant.

[0071] Comparative Example 2

[0072] The commercial T151 ashless dispersant was used as a comparative dispersant.

[0073] Comparative Example 3

[0074] The commercial T154 ashless dispersant was used as a comparative dispersant.

[0075] Examples 6 to 10 and Comparative Examples 4 to 6 of Electric Vehicle Gearbox Lubricant Compositions

[0076] According to the formulation in Table 1, examples 6 to 10 and comparative examples 4 to 6 of electric vehicle gearbox lubricating oil compositions were prepared respectively.

[0077] Table 1 Electric vehicle gearbox lubricant composition

[0078]

[0079] The kinematic viscosity, high temperature oxidation resistance, copper corrosion, volume resistivity and thermal conductivity of the examples and comparative examples of the electric vehicle gearbox lubricating oil composition were measured.

[0080] The main test methods are as follows:

[0081] The kinematic viscosity determination method is GB / T 265 standard method;

[0082] The high temperature oxidation resistance test was conducted using the DKA oxidation test, using the CEC L-48-00 standard method, with the test conditions of 170°C, 192h, and 83cc / min air;

[0083] The copper corrosion test adopts GB / T 5096 standard method, the test conditions are 150℃, 192h;

[0084] The volume resistivity was determined using the GB / T5654 standard method;

[0085] The thermal conductivity was determined using the ASTM D 2717 standard method.

[0086] The measurement results of the embodiments and comparative examples of the electric vehicle gearbox lubricant composition are shown in Table 2.

[0087] Table 2 Evaluation test results of electric vehicle gearbox lubricant

[0088]

[0089] It can be seen from the above test results that the lubricating oil composition of the present invention has excellent electrical insulation, heat dissipation and copper corrosion resistance. The volume resistivity and copper corrosion resistance of the new oil and the aged oil of the embodiment composition of the present invention are better than those of the comparative example, and the high-temperature thermal conductivity is greater than that of the comparative example, indicating that the cooling performance of the embodiment oil is also better than that of the comparative example.

[0090] The electric vehicle gearbox lubricating oil composition of the present invention has excellent electrical insulation performance and copper corrosion resistance, and still has good electrical insulation performance and copper corrosion resistance after experiencing oxidative degradation.

Claims

1. An electric vehicle gearbox lubricating oil composition, consisting of the following components: (A) Aromatic amine type ashless dispersant, accounting for 1% to 5% of the total mass of the composition; (B) viscosity index improver, accounting for 0.5% to 3% of the total mass of the composition; (C) extreme pressure anti-wear agent, accounting for 0.1% to 2% of the total mass of the composition; (D) antioxidant, accounting for 0.5% to 3% of the total weight of the composition; (E) metal deactivator, accounting for 0.01% to 0.2% of the total mass of the composition; (F) base oil, constituting the main component of the composition; The preparation method of the aromatic amine type ashless dispersant comprises: (1) causing isocyanic anhydride to undergo a ring-opening reaction with polyene polyamine; (2) in the presence of diluent oil, subjecting the ring-opening reaction product obtained in step (1) to an imidization reaction with polyisobutylene succinic anhydride, and collecting the reaction product; wherein the number average molecular weight of the polyisobutylene in the polyisobutylene succinic anhydride is 800-2500 g / mol.

2. The lubricating oil composition according to claim 1, characterized in that In step (1), the temperature of the ring-opening reaction is 90-220° C.; the time of the ring-opening reaction is 1-10 hours; and the molar ratio of the isatoic anhydride to the polyene polyamine is 0.1-1:

1.

3. The lubricating oil composition according to claim 1, characterized in that In step (1), the ring-opening reaction is carried out under an inert atmosphere.

4. The lubricating oil composition according to claim 1, characterized in that In step (2), the molar ratio of the polyisobutylene succinic anhydride to the polyene polyamine in step (1) is 0.5-3:1; the temperature of the imidization reaction is 80-180° C.; and the reaction time is 1-10 hours.

5. The lubricating oil composition according to claim 1, characterized in that: In step (2), the amount of the diluent oil used is 25% to 300% of the mass of the polyisobutylene succinic anhydride.

6. The lubricating oil composition according to claim 1, characterized in that In step (2), the polyisobutylene succinic anhydride is added to a mixture of the ring-opening reaction product obtained in step (1) and diluent oil.

7. The lubricating oil composition according to claim 1, characterized in that The structural formula of the polyene polyamine is H2N(CH2CH2NH) n H, wherein n is an integer from 1 to 4.

8. The lubricating oil composition according to claim 1, characterized in that The viscosity index improver is selected from polymethacrylate and / or polyisobutylene; the extreme pressure anti-wear agent is selected from one or more of phosphate esters, thiophosphates and phosphate amine salts; 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 benzotriazole derivatives, thiazole derivatives and thiadiazole derivatives; the base oil is selected from one or more of APII, II, III, IV and V base oils.

9. The lubricating oil composition according to claim 1, characterized in that The viscosity index improver has a kinematic viscosity of 500-1500 mm at 100°C. 2 / s polymethacrylate and / or polyisobutylene with a number average molecular weight of 1000-3400; the extreme pressure anti-wear agent is selected from one or more of tricresyl phosphate, di-n-butyl phosphite, dialkyl dithiophosphate and isooctyl phosphate octadecylamine salt; the antioxidant is selected from one or more of dibutyl diphenylamine, dioctyl diphenylamine, butyl / octyl diphenylamine, didodecyl diphenylamine, dipentyl diphenylamine, N-phenyl-α-naphthylamine, 2,6-di-tert-butyl-p-cresol and 2,6-di-tert-butyl-4-hydroxyphenyl propionate; the metal deactivator is selected from one or more of alkylaminomethylene benzotriazole, benzotriazole dialkylamine formaldehyde condensate, thiadiazole polysulfide and thiadiazole alkyl mercaptan hydroperoxide condensate; the base oil is selected from one or more of Class I base oil, Class II hydrogenated base oil, Class III hydrogenated base oil, polyalpha-olefin, alkylbenzene and alkylnaphthalene.

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