Lubricating oil composition for electric drive system and application thereof

Abstract

The invention relates to a lubricating oil composition for an electric driving system and application thereof. Based on 100 parts by weight of the composition, the lubricating oil composition comprises 70-95 parts by weight of base oil, and the base oil is selected from at least one or a combination of synthetic oil prepared by Fischer-Tropsch reaction, polyethylene oil, polyethylene degraded oil, poly-alpha-olefin oil and synthetic gas polymerized oil; the base oil has a kinematic viscosity of 1.2 to 13 cst at 100 DEG C as measured according to GB / T 265, a specific heat capacity of 1.8 to 2.5 J / gK at 20 DEG C as measured according to ASTM E1269 standard, and a density of 0.78 to 0.85 g / mL at 20 DEG C as measured according to GB / T 1884; the partial discharge PDIV of the lubricating oil composition after oil resistance is greater than or equal to 70% of an initial value; the breakdown voltage of the lubricating oil composition after oil resistance is greater than or equal to 70% of the initial value.

Description

Technical Field

[0001] The present invention belongs to the technical field of lubricating oils, and in particular relates to a lubricating oil composition for an electric drive system and an application thereof. Background Art

[0002] New energy vehicles refer to vehicles that use unconventional automotive fuels as their power source, including pure electric vehicles, extended-range electric vehicles, hybrid vehicles, fuel cell electric vehicles, hydrogen engine vehicles, etc. Traditional fuel vehicles use internal combustion engines to generate power and transmissions to drive the vehicle. New energy vehicles, on the other hand, are mostly powered by electric drive systems consisting of motors and reducers.

[0003] At present, the drive motor in new energy vehicles is mainly cooled by water cooling for stator or rotor, while the reducer is lubricated and cooled by reducer oil. Range anxiety is one of the biggest bottlenecks restricting the development of new energy vehicles, especially electric vehicles. The core issue of solving range anxiety is to solve the range and charging speed. As the core powertrain of new energy vehicles, the future development trend of electric drive system is integration, high voltage, high power, miniaturization and lightweight. The application of new processes and technologies such as 800V high voltage architecture, flat wire process, high-speed motor, etc. makes the drive motor generate greater heat load. High temperature will not only reduce the magnetic flux density, resulting in a decrease in rotor torque, but also affect the insulation life. When the temperature exceeds the insulation limit, it will directly lead to insulation failure. Considering the insulation problem, the traditional water cooling method can only be indirectly cooled in the form of a water jacket, and the thermal resistance is large, so it is impossible to effectively cool the motor windings, notches and other parts with high heat generation. Since the lubricating oil has insulation properties, direct oil cooling can be used, that is, spraying the lubricating oil to the high-temperature parts of the drive motor for direct cooling, and taking away the heat through the lubricating oil is an effective cooling method. The lubricating oil used to cool the drive motor can also be used to lubricate and cool the reducer. With this structure, the same lubricating oil can be used to cool the motor and lubricate the reducer at the same time, which can not only better cool the motor, but also greatly improve system efficiency, reduce system complexity, and reduce costs. Oil-cooled electric drive systems have become the direction of future development.

[0004] As an important component in the electric drive system, electric drive lubricants not only need to lubricate the reduction mechanism or speed change mechanism, but also the oil pump and other parts need to cool the motor and even the inverter. At present, there are no specifications and standards for electric drive lubricants for new energy vehicles in the industry. The use of inappropriate lubricants will not only cause the loss of motor insulation function, but also cause abrasions, pitting, bonding, etc. on the gears of the reduction and speed change mechanisms, as well as wear and pitting of the bearings. In particular, electric drive lubricants need to better cool the motor and improve the efficiency of the electric drive system. Therefore, it is necessary to develop special electric drive lubricants for new energy vehicles to meet this type of new application. Summary of the invention

[0005] In view of the above problems, an object of the present invention is to provide a lubricating oil composition for an electric drive system and application thereof.

[0006] The first aspect of the present invention provides a lubricating oil composition, which comprises, based on 100 parts by weight of the composition, 70 to 95 parts by weight of a base oil, wherein the base oil is selected from at least one of a synthetic oil prepared by a Fischer-Tropsch reaction, a polyethylene oil, a polyethylene degradation oil, a poly-α-olefin oil and a synthetic gas polymerization oil or a combination thereof; the base oil has:

[0007] The kinematic viscosity at 100°C measured according to GB / T 265 is 1.2 to 13 cst.

[0008] The specific heat capacity at 20°C measured according to ASTM E1269 is 1.8 to 2.5 J / g·K, and

[0009] The density at 20°C measured according to GB / T 1884 is 0.78-0.85 g / mL;

[0010] The partial discharge PDIV of the lubricating oil composition after oil resistance is ≥ 70% of the initial value, and the breakdown voltage of the lubricating oil composition after oil resistance is ≥ 70% of the initial value.

[0011] Preferably, the kinematic viscosity of the base oil at 100° C. measured according to GB / T 265 is 1.2 to 2.9 cst, or the kinematic viscosity of the base oil at 100° C. measured according to GB / T 265 is 3.8 to 6.5 cst.

[0012] Preferably, the synthetic oil produced by the Fischer-Tropsch reaction has carbon atoms ranging from C12 to C40.

[0013] Preferably, the polyethylene oil is a highly branched oily alkane mixture, and preferably, the number of methyl groups corresponding to every 1000 methylene groups in the highly branched oily alkane mixture is 100 to 500, and the degree of branching BI is 0.20 to 0.50.

[0014] Preferably, the polyethylene degradation oil is obtained by multiple cross-metathesis reactions of polyethylene and C2-C10 alkanes;

[0015] Preferably, the synthesis gas polymerization oil is synthesis gas produced by Fischer-Tropsch synthesis, and the synthesis gas is carbon monoxide and hydrogen; preferably, the synthesis gas is produced by coal gasification technology, carbon dioxide hydrogenation technology or carbon dioxide dry reforming technology.

[0016] Preferably, the poly α-olefin oil is a C5-C14 α-olefin oligomer, preferably with a molecular weight of 150-500.

[0017] Preferably, the lubricating oil composition of the present invention further comprises at least one of the following additives or a combination thereof: 1 to 5 parts by weight of a dispersant; 0.1 to 2 parts by weight of a seal expansion agent.

[0018] More preferably, the dispersant is selected from at least one of monoalkenyl succinimide, diene succinimide, boronated succinimide or a combination thereof; and / or the seal expansion agent is selected from at least one of organic phosphates, monoester oils, diester oils, polyol ester oils or a combination thereof.

[0019] More preferably, the lubricating oil composition of the present invention further comprises at least one of the following additives or a combination thereof:

[0020] 1 to 10 parts by weight of a viscosity index improver;

[0021] 0.1 to 2 parts by weight of detergent;

[0022] 0.1 to 3 parts by weight of extreme pressure anti-wear agent;

[0023] 0.1 to 3 parts by weight of a friction reducer;

[0024] 0.1 to 1 part by weight of a pour point depressant;

[0025] 0.1 to 2 parts by weight of an antioxidant;

[0026] 0.01 to 2 parts by weight of a rust inhibitor;

[0027] 0.01 to 1 parts by weight of a metal deactivator;

[0028] 0.001 to 0.05 parts by weight of anti-foaming agent.

[0029] The present invention adds dispersant, extreme pressure anti-wear agent, friction reducer, antioxidant and seal expansion agent to the base oil. Through the synergistic effect of these components, the obtained lubricating oil composition has excellent low-temperature performance, outstanding high-temperature stability, excellent gear and bearing protection ability, excellent anti-oxidation performance and good compatibility with copper and motor materials.

[0030] The above additives of the present invention all have specific functions. Among them, low temperature performance is improved by base oil and pour point depressant; high temperature stability is improved by base oil and antioxidant; excellent gear and bearing protection ability is improved by extreme pressure anti-wear agent; anti-oxidation performance is improved by antioxidant; copper corrosion is improved by metal deactivator and inactive extreme pressure anti-wear agent in the formula; motor material compatibility is more complicated and requires more balance of multiple additives in the formula.

[0031] Preferably, the viscosity index improver is selected from at least one of polymethacrylate copolymers, ethylene and α-olefin copolymers, polyα-olefins, or a combination thereof.

[0032] More preferably, the viscosity index improver has a PSSI of less than 20.

[0033] More preferably, the viscosity index improver is a mixture of a polymethacrylate copolymer and a metallocene polyalphaolefin.

[0034] Preferably, the extreme pressure anti-wear agent is selected from at least one of sulphurized olefins, alkyl polysulfides, ammonium thiophosphates, ammonium phosphates, phosphites, dialkyl dithiophosphates or a combination thereof.

[0035] Considering that sulfur-containing active extreme pressure anti-wear agents may have significant negative effects, the extreme pressure anti-wear agents in the present invention are preferably alkyl polysulfides, ammonium phosphates and phosphates.

[0036] Preferably, the weight ratio of alkyl polysulfide, ammonium phosphate and phosphate in the extreme pressure anti-wear agent is (0.3-0.5): (0.5-0.6): 0.3.

[0037] Preferably, the friction reducer is selected from at least one of dialkyl dithiocarbamate, fatty amine, fatty amide, fatty acid glyceride, borate, or a combination thereof;

[0038] and / or, the pour point depressant is a polymethacrylate copolymer and / or a poly-α-olefin, the polymethacrylate copolymer in the pour point depressant is different from the polymethacrylate copolymer in the viscosity index improver, and the poly-α-olefin in the pour point depressant is different from the poly-α-olefin oil in the base oil;

[0039] And / or, the antioxidant is an amine antioxidant and / or a phenolic antioxidant;

[0040] And / or, the detergent is selected from at least one of alkyl sulfonates, alkylbenzene sulfonates, substituted alkylphenol salts, aromatic carboxylates, or a combination thereof.

[0041] Preferably, the rust inhibitor is selected from at least one of alkenyl succinate, alkyl naphthalene sulfonate, oleoyl sarcosine, neutral / low base value petroleum calcium sulfonate or a combination thereof.

[0042] Preferably, the metal deactivator is selected from benzotriazole derivatives and / or thiadiazole derivatives.

[0043] Preferably, the antifoaming agent is selected from at least one of a silicone antifoaming agent or a non-silicon antifoaming agent or a combination thereof.

[0044] Preferably, the lubricating oil composition satisfies one or more of the following characteristics:

[0045] The dynamic viscosity of the lubricating oil composition at -40°C is not higher than 5000 mPa·s;

[0046] The kinematic viscosity of the lubricating oil composition at 100°C is not less than 2 mm 2 / s;

[0047] The pour point of the lubricating oil composition is not higher than -60°C;

[0048] The lubricating oil composition has a copper strip rating of not less than 1B after a copper strip corrosion test at 150°C for 192 hours;

[0049] The load-bearing capacity gear test FZG A10 / 16.6R / 90 failure level of the dynamic lubricating oil composition is not less than level 7;

[0050] The thermal conductivity of the lubricating oil composition at 30° C. is 0.14 to 0.15 W / (mK);

[0051] The bearing wear of the lubricating oil composition tested at 80 kN, 80 hr, and 80° C. is ≤3.0 mg.

[0052] A second aspect of the present invention provides application of the lubricating oil composition in new energy vehicles.

[0053] The third aspect of the present invention provides the use of the lubricating oil composition in the field of electric drive systems.

[0054] Preferably, the electric drive system field is a drive motor and / or a transmission system.

[0055] Beneficial effects of the present invention:

[0056] In the present invention, an extreme pressure anti-wear agent containing low active sulfur is added to the base oil, so that the lubricating oil composition has excellent partial discharge PDIV after oil resistance and breakdown voltage after oil resistance.

[0057] The lubricating oil composition for electric drive system provided in the present invention is obtained by adding a specific content of dispersant and a specific type of seal expansion agent to the base oil. Through the synergistic effect of these components, the lubricating oil composition has excellent low temperature performance, outstanding high temperature stability, excellent gear and bearing protection ability, excellent anti-oxidation performance, and good compatibility with copper and motor materials. The lubricating oil composition of the present invention is particularly suitable for electric drive systems in new energy vehicles. DETAILED DESCRIPTION

[0058] The present invention is further described below by the following embodiments. It should be understood that the following embodiments are only used to illustrate the present invention, but not to limit the present invention.

[0059] In the present invention, "parts by weight" should be interpreted as relative parts by weight, which can be any weight unit, such as but not limited to kilograms, kilograms, grams, pounds and other weight units. For example, 95 parts by weight of base oil means that it can be 95 kilograms of base oil or 95 pounds of base oil.

[0060] In one embodiment of the present invention, based on 100 parts by weight of the composition, the lubricating oil composition comprises the following components: 70 to 95 parts by weight of a base oil (preferably 80 to 95 parts by weight), wherein the base oil has a kinematic viscosity at 100°C of 1.2 to 13 cst (e.g., 1.2 to 2.9 cst or 3.8 to 6.5 cst) as measured in accordance with GB / T 265, a specific heat capacity at 20°C of 1.8 to 2.5 J / g·K as measured in accordance with ASTM E1269, and a density at 20°C of 0.78 to 0.85 g / mL as measured in accordance with GB / T 1884. Wherein, cst represents centistokes in units of square millimeters per second (i.e., 1 cst = 1 mm 2 / s). The partial discharge PDIV of the lubricating oil composition after oil resistance is ≥ 70% of the initial value, preferably ≥ 75% of the initial value, and more preferably ≥ 80% of the initial value. The breakdown voltage of the lubricating oil composition after oil resistance is ≥ 70% of the initial value, preferably ≥ 75% of the initial value, and more preferably ≥ 80% of the initial value.

[0061] In another embodiment of the present invention, the lubricating oil composition comprises the following components based on 100 parts by weight of the composition: 70 to 95 parts by weight of base oil (including one or a combination of synthetic oil made by Fischer-Tropsch reaction, polyethylene oil, polyethylene degradation oil, polyalphaolefin oil, and synthetic gas polymerization oil), dispersant and / or seal expansion agent.

[0062] In another embodiment of the present invention, the lubricating oil composition comprises the following components based on 100 parts by weight of the composition: 70 to 95 parts by weight of base oil (including one or a combination of synthetic oil made by Fischer-Tropsch reaction, polyethylene oil, polyethylene degradation oil, polyalphaolefin oil, and syngas polymerization oil), optional viscosity index improver, extreme pressure antiwear agent, friction reducer, pour point depressant, antioxidant, optional detergent, dispersant, seal expansion agent, rust inhibitor, metal deactivator and antifoaming agent.

[0063] In the present invention, the term "kinematic viscosity" is a physical quantity that measures the magnitude of the internal flow resistance of a fluid under the action of gravity, wherein the kinematic viscosity at 40°C and the kinematic viscosity at 100°C are both tested according to the national standard GB / T265 "Method for Determination of Kinematic Viscosity of Petroleum Products and Method for Calculation of Dynamic Viscosity".

[0064] In one embodiment of the present invention, the synthetic oil produced by the Fischer-Tropsch reaction is coal-to-oil, that is, coal is first gasified into synthesis gas, and then the base oil is produced by Fischer-Tropsch synthesis. The synthetic oil produced by the Fischer-Tropsch reaction can be produced from synthesis gas containing H2 and CO using a Fischer-Tropsch catalyst. The synthetic oil produced by the Fischer-Tropsch reaction of the present invention preferably has 12 to 40 carbon atoms. The number of carbon atoms in the synthetic oil of the present invention can be measured by combining means such as nuclear magnetic hydrogen spectrum and carbon spectrum.

[0065] In one embodiment of the present invention, the polyethylene oil is a highly branched oily alkane mixture, which is obtained by ethylene catalytic polymerization, hydrogenation, etc. The number of methyl groups corresponding to every 1000 methylene groups in the highly branched oily alkane mixture is 100 to 500, and the degree of branching BI is 0.20 to 0.50. The polyethylene degradation oil is obtained by multiple cross-metathesis reactions of polyethylene and C2 to C10 alkanes.

[0066] In one embodiment of the present invention, the polyalphaolefin oil is a C5-C14 alpha olefin oligomer, and its molecular weight is 150 to 500. The polyalphaolefin oil has a kinematic viscosity of 1.2 to 2.9 cst or 3.8 to 6.5 cst at 100° C., a specific heat capacity (20° C.) of 1.8 to 2.5 J / g·K, and a density (20° C.) of 0.78 to 0.85 g / mL.

[0067] In one embodiment of the present invention, the synthesis gas polymerization oil is synthesis gas (carbon monoxide and hydrogen) prepared by Fischer-Tropsch synthesis or the like.

[0068] In one embodiment of the present invention, the syngas polymerized oil is syngas (carbon monoxide and hydrogen) produced by Fischer-Tropsch synthesis, etc., and the syngas is produced by coal gasification technology, carbon dioxide hydrogenation technology or carbon dioxide dry reforming technology. In other words, syngas polymerized oil refers to base oil produced by directly using natural gas for Fischer-Tropsch synthesis.

[0069] In a preferred embodiment of the present invention, the kinematic viscosity of the base oil at 100°C is 1.2 to 13 cst; further, the kinematic viscosity of the base oil at 100°C is 1.2 to 10 cst; further, the kinematic viscosity of the base oil at 100°C is 1.2 to 7 cst.

[0070] In a preferred embodiment of the present invention, the specific heat capacity (20° C.) of the base oil is 2.0 to 2.5 J / g·K.

[0071] In a preferred embodiment of the present invention, the density of the base oil (20°C) is 0.78-0.82 g / mL, wherein the density is obtained by testing according to the national standard GB / T 1884.

[0072] The base oil of the present invention can be prepared according to methods known in the art, and used after being treated accordingly in known methods, for example, it can be hydroisomerized according to the method disclosed in U.S. Patent No. 6,103,099 or 6,180,575; hydrocracking and hydroisomerization using the method disclosed in U.S. Patent No. 4,943,672 or 6,096,940; dewaxing using the method disclosed in U.S. Patent No. 5,882,505; or hydroisomerized and dewaxed using the method disclosed in U.S. Patent Nos. 6,013,171, 6,080,301 or 6,165,949.

[0073] In some embodiments, the base oil may be a single type, or two or more base oils may be mixed and used in a certain ratio.

[0074] The term "viscosity index" in the present invention refers to the degree to which the viscosity of a fluid changes with temperature, and is obtained by testing according to the national standard GB / T1995.

[0075] The term "pour point" in the present invention refers to the lowest temperature at which a cooled lubricating oil sample can flow under specified test conditions. The pour point in the present invention is obtained by testing according to the national standard GB / T 3535 "Determination of pour point of petroleum products".

[0076] The synthetic oil prepared by the Fischer-Tropsch reaction of the present invention can also use relevant products commercially available on the market, such as ICCSYN 3, ICCSYN 4, ICCSYN 6 of Shanxi Lu'an Taihang Lubricating Oil, DURASYN 142, DURASYN 164, DURASYN 166 of INOES, SpectraSyn MaX3.5, SpectraSyn 4, SpectraSyn 6, polyethylene oil 4# and polyethylene oil 6# of EXXON MOBIL.

[0077] In one embodiment of the present invention, the lubricating oil composition comprises 1 to 10 parts by weight of a viscosity index improver for improving the shear performance and low temperature performance of the lubricating oil composition. As a preferred technical solution of the present invention, the viscosity index improver is selected from one or more of polymethacrylate copolymers, ethylene and α-olefin copolymers, and polyα-olefins. The polyα-olefins described in the present invention include but are not limited to homopolymers of 1-hexene, 1-octene, 1-decene, etc., which can be a single component of the above homopolymers or a mixture of two or more. More preferably, the PSSI of the viscosity index improver is less than 20.

[0078] In the present invention, the term "PSSI" refers to the permanent shear stability index, which represents the irreversible viscosity loss of the lubricating oil caused by strong mechanical shearing of the gears and bearings during the operation of the electric drive system. The parameter is obtained by testing according to NB / SH / T 0845 Determination of Viscosity Shear Stability of Transmission Lubricants (Tapered Roller Bearing Tester Method).

[0079] In some preferred embodiments, the viscosity index improver is a mixture of polymethacrylate copolymer and metallocene polyalpha-olefin (especially high molecular weight metallocene polyalpha-olefin with a molecular weight of 2000 g / mol or more), and the two components are mixed in a certain ratio (for example, the weight ratio of polymethacrylate copolymer to metallocene polyalpha-olefin is (0.5-2):1, preferably 1:1)) as a viscosity index improver. Among them, the polymethacrylate copolymer in the electric drive lubricant composition system of the present invention can make the composition have better low temperature performance and viscosity-temperature performance, while the metallocene polyalpha-olefin can make the composition have better shear stability, and the synergistic effect of the two can better improve the comprehensive performance of the composition.

[0080] In the present invention, the viscosity index improver can be a commercially available product on the market, including but not limited to VISCOPLEX 12-100 and VISCOPLEX 0-030 produced by EVONIK of Germany, ACLUBE 1050 and ACLUBE 1060 produced by Sanyo of Japan, LZ 8420 produced by Lubrizol of the United States, and other polymethacrylate copolymer products; SpectraSyn Elite 150 and SpectraSyn Elite 300 produced by EXXON MOBIL, and other metallocene polyalphaolefin products.

[0081] The above commercially available viscosity index improver products can be used alone or in combination of two or more products in a certain ratio.

[0082] In one embodiment of the present invention, the lubricating oil composition contains 0.1 to 3 parts by weight of an extreme pressure anti-wear agent to improve the wear protection of the lubricating oil composition for gears and bearings during operation. The extreme pressure anti-wear agent is selected from one or more of sulfided olefins, alkyl polysulfides, ammonium thiophosphates, ammonium phosphates, phosphites, phosphates, and dialkyl dithiophosphates.

[0083] In some preferred embodiments, the extreme pressure anti-wear agent is alkyl polysulfide, ammonium phosphate and phosphate, and preferably the weight ratio of alkyl polysulfide, ammonium phosphate and phosphate is (0.3-0.5): (0.5-0.6): 0.3. Adding an appropriate amount of compounded alkyl polysulfide, ammonium phosphate and phosphate to the composition system of the present invention can not only provide excellent gear and bearing wear protection for the composition system of the present invention, but also reduce the content of active sulfur in the system, reduce the corrosion of metal materials, especially copper-containing parts in motors, and have a good synergistic effect.

[0084] In a preferred embodiment of the present invention, the extreme pressure anti-wear agent can be a commercially available product on the market, including but not limited to alkyl polysulfide products such as TPS20 and TPS44 from ARKEMA; phosphate ester ammonium salt products such as T308 and P120 from Shenyang Hualun Lubricant Additive Co., Ltd.; and phosphate ester products such as DURAD 150B from LANXESS.

[0085] In one embodiment of the present invention, the lubricating oil composition contains 0.1 to 3 parts by weight of a friction reducer to reduce the friction coefficient of the electric drive lubricating oil composition to steel. As a preferred technical solution of the present invention, the friction reducer is selected from one or more of dialkyl dithiocarbamates, fatty amines, fatty amides, fatty acid glycerides, and borates. The fatty acid glyceride can be a compound obtained by esterification of glycerol and fatty acids, and the fatty acid can include but is not limited to erucic acid, stearic acid, oleic acid, lauric acid, palmitic acid, etc. Preferably, the fatty acid glyceride is monoolein. The friction reducer of the present invention can adopt relevant products commercially available on the market, including but not limited to dialkyl dithiocarbamate products such as NA-LUBE ADTC of King's Industries; fatty amines such as Fentacare C15 of Solvay; monoolein such as Radiasurf 7148 of Oleon, etc.

[0086] In one embodiment of the present invention, the lubricating oil composition contains 0.1 to 1 parts by weight of a pour point depressant to reduce the pour point and low temperature dynamic viscosity of the lubricating oil composition and improve the low temperature fluidity of the lubricating oil composition. In some preferred embodiments, the pour point depressant is one of a polymethacrylate copolymer or a polyalphaolefin or a mixture thereof. Among them, the molecular weight of the polyalphaolefin in the pour point depressant is larger, usually above 2000. The polymethacrylate copolymer used as a pour point depressant in the present invention is different from the polymethacrylate copolymer used as a viscosity index improver, and commercially available related products on the market can be used, including but not limited to EVONIK's VISCOPLEX 1-360, VISCOPLEX 1-300, Japan Sanyo's ACLUBE P4300, Lanzhou China Petroleum Lubricant Additives Company's Kunlun T809 and other polymethacrylate copolymer products.

[0087] In one embodiment of the present invention, the lubricating oil composition contains 0.1 to 2 parts by weight of an antioxidant. As a preferred technical solution of the present invention, the antioxidant is an amine, phenolic antioxidant or a mixture thereof. The amine and phenolic antioxidants are compounded to significantly improve the antioxidant capacity of the oil. Amine antioxidants may include but are not limited to β-naphthylamine, phenyl-α-naphthylamine, butyl-octyl diphenylamine, octyl-octyl diphenylamine (dioctyl diphenylamine), nonyl-nonyl diphenylamine (dinonyl diphenylamine), etc.; phenolic antioxidants may include but are not limited to 2,6-di-tert-butyl-p-cresol, 4,4'-methylenebis (2,6-di-tert-butylphenol), 3,5-di-tert-butyl-4-hydroxyphenyl methyl acrylate, etc.

[0088] In a preferred embodiment of the present invention, commercially available antioxidants can be used, for example, amine antioxidants can use T534 from Beijing Xingpu Fine Chemical Technology Development Co., Ltd., RF5057, RF5067 from Ruifeng New Materials and other products; phenolic antioxidants can use T512 from Beijing Xingpu Fine Chemical Technology Development Co., Ltd., RF1135 from Ruifeng New Materials and other products.

[0089] In one embodiment of the present invention, the lubricating oil composition contains 0.1 to 2 parts by weight of detergent. As a preferred technical solution of the present invention, the detergent is selected from one or more of alkyl sulfonates, alkylbenzene sulfonates, substituted alkylphenols, and aromatic carboxylates; further, the alkylbenzene sulfonates are synthetic alkylbenzene sulfonates, including but not limited to synthetic calcium alkylbenzene sulfonate, synthetic magnesium alkylbenzene sulfonate, etc.; the substituted alkylphenols include but not limited to sulfurized calcium alkylphenols, etc.; aromatic carboxylates include but not limited to calcium salicylate, magnesium salicylate, etc.

[0090] In a preferred embodiment of the present invention, commercially available detergents can be used, such as BD C150 and BD C300 of Jinzhou Kangtai, RF1105 and RF1106B of Ruifeng New Materials, synthetic alkylbenzene sulfonate calcium products; RF1107 and other synthetic alkylbenzene sulfonate magnesium products of Ruifeng New Materials; T121 and T122 of Wuxi Nanfang Petroleum Additives, RF1121 and RF1122 of Ruifeng New Materials, and other sulfided alkylphenol calcium products; T109 and other calcium salicylate products of Jinzhou Kangtai;

[0091] In one embodiment of the present invention, the lubricating oil composition contains 1 to 5 parts by weight of a dispersant. As a preferred technical solution of the present invention, the dispersant is selected from one or more of monoalkenyl succinimide, diene succinimide, and boronized succinimide. The main functions of the lubricating oil dispersant include the following: 1. Dispersion and solubilization: The dispersant can disperse and solubilize the non-soluble or unstable substances in the lubricating oil, prevent these substances from precipitating in the oil and forming sediments, thereby improving the service life and performance of the lubricating oil and protecting the normal operation of the machine or equipment. 2. Antioxidation: The precipitates and sediments in the lubricating oil may cause oxidation of the oil and reduce the performance and life of the lubricating oil. The dispersant can stably disperse these precipitates in the oil, reduce the occurrence of oxidation reactions, and extend the service life of the lubricating oil. 3. Corrosion resistance: Some precipitates are corrosive and will corrode the metal surface of the machine or equipment, causing damage to the equipment. The dispersant can disperse these precipitates in the lubricating oil to prevent them from directly contacting the metal surface and reduce the occurrence of corrosion. 4. Cleanliness: Sediments deposited on the surface of a machine or equipment will gradually form dirt, reduce the efficiency of the machine or equipment, and even cause malfunctions. Dispersants can effectively disperse these deposits in the oil to keep the machine or equipment clean. 5. Washing effect: Dispersants can wash off the paint film and carbon deposits that have been adsorbed on the surface of the parts and disperse them in the oil to keep the engine and metal surfaces clean. 6. Prevent sludge from agglomerating: Dispersants can adsorb sludge formed at lower operating temperatures, prevent it from agglomerating into sludge deposits, and disperse it and suspend it in the oil, thereby keeping the lubrication oil circuit unobstructed. In summary, lubricating oil dispersants can effectively disperse and stabilize solid particle pollutants in the oil through their surface activity, reduce the formation of sludge and carbon deposits, improve the performance and service life of the lubricating oil, and protect mechanical equipment from corrosion and wear. In the present invention, commercially available dispersants on the market can be used, such as Jinzhou Kangtai's KT1051, Ruifeng New Materials' RF1151 monoolefin succinimide; Jinzhou Kangtai's KT1354, Ruifeng New Materials' RF1154 diene succinimide; Jinzhou Kangtai's KT1354B, Wuxi Southern Petroleum Additives Company's T154B boronated succinimide.

[0092] In one embodiment of the present invention, the lubricating oil composition contains 0.1 to 2 parts by weight of a seal expansion agent. As a preferred technical solution of the present invention, the seal expansion agent is selected from one or more of organic phosphates, monoester oils, diester oils, and polyol ester oils. The main functions of the lubricating oil seal expansion agent are as follows: 1. Prevent oil leakage: The seal expansion agent can keep the elastomer slightly expanded, thereby helping the seal to maintain its sealing performance under various conditions and prevent oil leakage in the lubricating oil system. 2. Protect seals: By maintaining hydraulic pressure, the seal expansion agent can protect the seal, making it easier to remove and replace faulty parts, while reducing the pollution and loss of lubricating oil. 3. Maintain hydraulic pressure: The seal expansion agent helps maintain the normal operation of the hydraulic system and reduce the problem of hydraulic pressure drop caused by poor sealing. 4. Maintain low temperature performance: Rubber seals may shrink at low temperatures, lose elasticity and sealing performance. The seal expansion agent can help the seal maintain its performance at low temperatures and prevent the sealing performance from decreasing due to temperature changes. 5. Improve the sealing effect: The viscosity of the lubricating oil makes it adhere to the surface of the moving parts, enhance the sealing effect of the parts, and reduce air leakage. 6. Wide application scope: As one of the lubricant additives, the seal expansion agent can expand the application scope of the lubricant, especially in applications requiring good sealing performance. In summary, the lubricant seal expansion agent plays an important role in ensuring the reliability of mechanical equipment and extending its service life by maintaining the expansion state of the seal, improving the sealing performance, reducing lubricant leakage, protecting the seal, and maintaining the normal operation of the hydraulic system. The present invention can use commercially available seal expansion agents on the market, such as DOA (dioctyl adipate) of Boju New Materials Company; Cargill's Priolube 3970 polyol ester.

[0093] In one embodiment of the present invention, the lubricating oil composition contains 0.01 to 2 parts by weight of a rust inhibitor. As a preferred technical solution of the present invention, the rust inhibitor is selected from one or more of alkenyl succinates, alkyl naphthalene sulfonates, and neutral / low-base petroleum calcium sulfonates. Under the synergistic effect of the above-mentioned detergent, synthetic oil prepared by Fischer-Tropsch reaction and other components of the present invention, the above-mentioned rust inhibitor can better produce a passivation layer on the metal surface or adsorb to the metal surface, preventing oxygen and water from attacking the metal, thereby playing a better role in preventing rust.

[0094] In a preferred embodiment of the present invention, commercially available rust inhibitors can be used, such as T746 and other alkenyl succinic acid products of Wuxi Southern Petroleum Additives Company; dinonylnaphthalene sulfonate calcium products such as Vanlube RI-CSN of Vanderbilt Company; and neutral / low base value calcium sulfonate products such as RC4103 and RC4202 of Rhein Chemie.

[0095] In one embodiment of the present invention, the lubricating oil composition contains 0.01 to 1 parts by weight of a metal deactivator. As a preferred technical solution of the present invention, the metal deactivator is a benzotriazole derivative and / or a thiadiazole derivative; the benzotriazole derivative includes but is not limited to benzotriazole, and the thiadiazole derivative includes but is not limited to 2,5-dimercapto-1,3,4-thiadiazole, 2-mercaptobenzothiadiazole, 2-mercaptobenzothiadiazole sodium, etc.

[0096] In a preferred embodiment of the present invention, commercially available metal deactivators can be used, such as T551, T555 and other benzotriazole derivatives produced by Beijing Xingpu Fine Chemical Technology Development Co., Ltd.; POUPC 6001-8, POUPC 6001-9 and other thiadiazole derivatives produced by Pacific Petrochemical Co., Ltd.

[0097] In one embodiment of the present invention, the lubricating oil composition contains 0.001 to 0.05 parts by weight of an antifoaming agent, which is also a defoaming agent. As a preferred technical solution of the present invention, the antifoaming agent is selected from one or more combinations of silicone antifoaming agents or non-silicon antifoaming agents. The antifoaming agent described in the present invention acts on the gas-liquid interface through its lower surface tension, making the bubble film thinner and thinner, thereby accelerating the merging and continuous rupture of bubbles, thereby achieving good antifoaming performance.

[0098] In a preferred embodiment of the present invention, commercially available antifoaming agents on the market may be used, such as T901, 1# composite antifoaming agent and other silicone defoaming agent products of Jinzhou Xinxing Petroleum Additives Co., Ltd.

[0099] As a preferred technical solution of the present invention, the pour point of the lubricating oil composition is not higher than -60°C; further, the pour point of the lubricating oil composition is not higher than -63°C.

[0100] Further preferably, the dynamic viscosity of the lubricating oil composition at -40°C is not higher than 5000 mPa·s; further, the dynamic viscosity of the lubricating oil composition at -40°C is not higher than 4000 mPa·s, and further the dynamic viscosity of the lubricating oil composition at -40°C is not higher than 1350 mPa·s. In the present invention, the dynamic viscosity of the lubricating oil composition at -40°C is tested according to GB / T 11145 standard.

[0101] Preferably, the dynamic viscosity of the lubricating oil composition at 100°C is not less than 2 mPa.s; more preferably, the dynamic viscosity of the lubricating oil composition at 100°C is 2 to 6 mPa.s. The dynamic viscosity described in the present invention refers to Brookfield viscosity, which is obtained by testing according to GB / T 265 standard.

[0102] Further preferably, the lubricating oil composition has a copper strip rating of not less than 1B after a copper strip corrosion test at 150° C. for 192 hours.

[0103] Further preferably, the load-bearing capacity gear test FZG A10 / 16.6R / 90 failure level of the dynamic lubricating oil composition is not less than level 7.

[0104] More preferably, the thermal conductivity of the lubricating oil composition at 30° C. is 0.14 to 0.15 W / (mK).

[0105] Further preferably, the bearing wear of the lubricating oil composition tested at 80 kN, 80 hr, and 80° C. is ≤3.0 mg.

[0106] More preferably, the viscosity index of the lubricating oil composition is 130-170.

[0107] More preferably, the flash point of the lubricating oil composition is 200-220°C.

[0108] More preferably, the evaporation loss (200° C., 1 hr) of the lubricating oil composition is ≤7.5%.

[0109] More preferably, the resistivity (30° C.) of the lubricating oil composition is ≤270 MΩ·m.

[0110] More preferably, the specific heat capacity (30° C.) of the lubricating oil composition is 2.05 to 2.30 J / (g*K).

[0111] Further preferably, the kinematic viscosity of the lubricating oil composition after aging at 180°C with 5L / h air for 192 hours (oxidation stability) changes by no more than 5% at 100°C and by no more than 7% at 40°C, wherein the specific treatment process is carried out in accordance with CEC L-48-B-00 standard.

[0112] In one embodiment of the present invention, the lubricating oil composition can be applied to the electric drive system of a new energy vehicle to lubricate and cool the motor and the gearbox at the same time.

[0113] The following further examples are given to illustrate the present invention in detail. It should also be understood that the following examples are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the above content of the present invention belong to the scope of protection of the present invention. The specific process parameters and the like in the following examples are also only examples within a suitable range, that is, those skilled in the art can make a selection within a suitable range through the description herein, and are not limited to the specific values ​​​​exemplified below.

[0114] Examples 1-4

[0115] The composition and properties of the base oil in Examples 1-4 (E1-E4) are shown in Table 1. The composition and content of the lubricating oil composition prepared using the base oil are shown in Table 2.

[0116] Table 1 shows the composition and content of the base oil of Examples 1-4 (unit: parts by weight)

[0117]

[0118] Table 2 shows the composition and content of the lubricating oil composition of Examples 1-4 (E1-E4) (unit: weight parts)

[0119]

[0120]

[0121] Comparative Example 1 (C1)

[0122] The lubricating oil composition in Comparative Example 1 comprises the following components based on the weight of the lubricating oil composition:

[0123] a) 90.44 parts by weight of a conventional hydroisomerized base oil (YUBASE 4);

[0124] b) 9.0 parts by weight of Lubrizol's electric drive lubricant additive package Evogen 4006;

[0125] c) 0.5 parts by weight of EVONIK's pour point depressant VISCOPLEX 1-300;

[0126] k) 0.06 parts by weight of an antifoaming agent; the antifoaming agent is composed of 0.05 parts by weight of 1# composite antifoaming agent and 0.01 parts by weight of T901 antifoaming agent.

[0127] The YUBASE 4 of SK Enmove Co., Ltd., the basis of the conventional hydroisomerization, has typical physical and chemical parameters as shown in Table 3 below.

[0128] Table 3

[0129] project YUBASE 4 Test Method Appearance Clear and transparent Visual inspection color ＜0.5 GB / T 6540 Density(20℃),g / mL 0.833 GB / T 1884 <![CDATA[Kinematic viscosity (40 °C), mm 2 / s]]> 19.44 GB / T 265 <![CDATA[Kinematic viscosity (100 °C), mm 2 / s]]> 4.27 GB / T 265 Viscosity Index 128 GB / T 1995 Flash point (open), ℃ 220 GB / T 3536 Pour point,℃ -18 GB / T 3535 Sulfur content (mg / kg) 3 GB / T 17476 Specific heat capacity (20℃), J / gK 2.00 ASTM E1269

[0130] The lubricating oil compositions in the above-mentioned Examples 1-4 and Comparative Example 1 were subjected to relevant performance tests, and the test standards thereof are shown in Table 4 below.

[0131] Table 4

[0132]

[0133]

[0134] The performance parameters of the lubricating oil compositions prepared in the examples and comparative examples of the present invention are shown in Table 5.

[0135] Table 5 shows the performance parameters of the lubricating oil compositions in Examples 1-4 and Comparative Example 1:

[0136]

[0137]

[0138] In summary, the lubricating oil composition of the present invention has excellent low-temperature performance, outstanding high-temperature stability, good gear and bearing protection ability, outstanding anti-oxidation performance, and good compatibility with copper and motor materials.

[0139] It should be noted that all technical features described in the present invention can be freely combined or combined in any way unless there is a contradiction between them. Various modifications and changes can be made to the present invention without departing from the scope of the present invention, which will be obvious to those skilled in the art. For example, a feature shown or described as part of one embodiment can be used together with another embodiment to produce another embodiment. Therefore, the present invention is intended to cover these modifications that fall within the scope of the appended claims and their equivalents.

Claims

1. A lubricating oil composition, characterized in that: The lubricating oil composition comprises, based on 100 parts by weight of the composition, 70 to 95 parts by weight of a base oil, wherein the base oil is selected from at least one of a synthetic oil prepared by a Fischer-Tropsch reaction, a polyethylene oil, a polyethylene degradation oil, a poly-α-olefin oil and a synthetic gas polymerization oil or a combination thereof; the base oil has: The kinematic viscosity at 100°C measured according to GB / T 265 is 1.2 to 13 cst. The specific heat capacity at 20°C measured according to ASTM E1269 is 1.8 to 2.5 J / g·K, and The density at 20°C measured according to GB / T 1884 is 0.78-0.85 g / mL; The partial discharge PDIV of the lubricating oil composition after oil resistance is ≥ 70% of the initial value, and the breakdown voltage of the lubricating oil composition after oil resistance is ≥ 70% of the initial value.

2. The lubricating oil composition according to claim 1, characterized in that The kinematic viscosity of the base oil at 100° C. measured according to GB / T 265 is 1.2 to 2.9 cst; or, the kinematic viscosity of the base oil at 100° C. measured according to GB / T 265 is 3.8 to 6.5 cst.

3. The lubricating oil composition according to claim 1, characterized in that The number of carbon atoms in the synthetic oil produced by the Fischer-Tropsch reaction is C12 to C40; The polyethylene oil is a highly branched oily alkane mixture, preferably the number of methyl groups corresponding to every 1000 methylene groups in the highly branched oily alkane mixture is 100 to 500, and the degree of branching BI is 0.20 to 0.50; The polyethylene degradation oil is prepared by multiple cross-metathesis reactions between polyethylene and C2-C10 alkanes; The synthesis gas polymerization oil is prepared from synthesis gas by Fischer-Tropsch synthesis, and the synthesis gas is carbon monoxide and hydrogen; preferably, the synthesis gas is prepared by coal gasification technology, carbon dioxide hydrogenation technology or carbon dioxide dry reforming technology.

4. The lubricating oil composition according to claim 1, characterized in that The poly α-olefin oil is a C5-C14 α-olefin oligomer, preferably with a molecular weight of 150-500.

5. The lubricating oil composition according to claim 1, characterized in that: The lubricating oil composition further comprises at least one of the following additives or a combination thereof: 1 to 5 parts by weight of a dispersant; 0.1 to 2 parts by weight of a seal expansion agent.

6. The lubricating oil composition according to claim 5, characterized in that The dispersant is selected from at least one of monoalkenyl succinimide, bisalkenyl succinimide, and boronated succinimide, or a combination thereof; And / or, the sealing member expansion agent is selected from at least one of organic phosphates, monoester oils, diester oils, polyol ester oils, or a combination thereof.

7. The lubricating oil composition according to claim 5, characterized in that The lubricating oil composition further comprises at least one of the following additives or a combination thereof: 1 to 10 parts by weight of a viscosity index improver; 0.1 to 2 parts by weight of detergent; 0.1 to 3 parts by weight of extreme pressure anti-wear agent; 0.1 to 3 parts by weight of a friction reducer; 0.1 to 1 part by weight of a pour point depressant; 0.1 to 2 parts by weight of an antioxidant; 0.01 to 2 parts by weight of a rust inhibitor; 0.01 to 1 parts by weight of a metal deactivator; 0.001 to 0.05 parts by weight of anti-foaming agent.

8. The lubricating oil composition according to claim 6, characterized in that The viscosity index improver is selected from at least one of polymethacrylate copolymers, ethylene and α-olefin copolymers, polyα-olefins, or a combination thereof; Preferably, the PSSI of the viscosity index improver is less than 20; Preferably, the viscosity index improver is a mixture of polymethacrylate copolymer and metallocene polyalphaolefin.

9. The lubricating oil composition according to claim 6, characterized in that: The extreme pressure anti-wear agent is selected from at least one of sulphurized olefins, alkyl polysulfides, ammonium thiophosphates, ammonium phosphates, phosphites, dialkyl dithiophosphates or a combination thereof; Preferably, the extreme pressure anti-wear agent is alkyl polysulfide, ammonium phosphate and phosphate; Preferably, the weight ratio of alkyl polysulfide, ammonium phosphate and phosphate in the extreme pressure anti-wear agent is (0.3-0.5): (0.5-0.6): 0.

3.

10. The lubricating oil composition according to claim 6, characterized in that: The friction reducer is selected from at least one of dialkyl dithiocarbamate, fatty amine, fatty amide, fatty acid glyceride, borate, or a combination thereof; and / or, the pour point depressant is a polymethacrylate copolymer and / or a poly-α-olefin, the polymethacrylate copolymer in the pour point depressant is different from the polymethacrylate copolymer in the viscosity index improver, and the poly-α-olefin in the pour point depressant is different from the poly-α-olefin oil in the base oil; And / or, the antioxidant is an amine antioxidant and / or a phenolic antioxidant; and / or, the detergent is selected from at least one of alkyl sulfonates, alkylbenzene sulfonates, substituted alkylphenol salts, aromatic carboxylates, or a combination thereof; And / or, the rust inhibitor is selected from at least one of alkenyl succinate, alkyl naphthalene sulfonate, oleoyl sarcosine, neutral / low base value petroleum calcium sulfonate or a combination thereof; and / or, the metal deactivator is selected from benzotriazole derivatives and / or thiadiazole derivatives; And / or, the antifoaming agent is selected from at least one of a silicone antifoaming agent or a non-silicon antifoaming agent or a combination thereof.

11. The lubricating oil composition according to claim 1, characterized in that The lubricating oil composition satisfies one or more of the following characteristics: The dynamic viscosity of the lubricating oil composition at -40°C is not higher than 5000 mPa·s; The kinematic viscosity of the lubricating oil composition at 100°C is not less than 2 mm 2 / s; The pour point of the lubricating oil composition is not higher than -60°C; The lubricating oil composition has a copper strip rating of not less than 1B after a copper strip corrosion test at 150°C for 192 hours; The load-bearing capacity gear test FZG A10 / 16.6R / 90 failure level of the dynamic lubricating oil composition is not less than level 7; The thermal conductivity of the lubricating oil composition at 30° C. is 0.14 to 0.15 W / (mK); The bearing wear of the lubricating oil composition tested at 80 kN, 80 hr, and 80° C. is ≤3.0 mg.

12. Use of the lubricating oil composition according to claim 1 in new energy vehicles.

13. Use of the lubricating oil composition according to claim 1 in the field of electric drive systems.

14. The use according to claim 13, characterized in that The electric drive system field is a drive motor and / or a transmission system.

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