An engine oil composition, its preparation and use

Abstract

The application belongs to the technical field of engine oil, and relates to an engine oil composition, a preparation method and application thereof.The engine oil composition comprises a specific amount of base oil, viscosity indicator, friction modifier, engine oil complexing agent and pour point depressant, and the base oil comprises CTL base oil and pentaerythritol ester base oil.By selecting CTL base oil and pentaerythritol ester base oil for compounding, the low-temperature performance and oxidation resistance of the obtained engine oil composition are significantly improved, and various additives can be stably dissolved in the base oil, so that the viscosity of the finally obtained engine oil composition is low, the oil consumption of the engine can be significantly reduced, the fuel economy is good, the oxidation resistance and wear resistance of the oil product are excellent, the service life of the engine oil can be prolonged, the content of phosphorus, sulfur and ash is reduced, and the compatibility with aftertreatment is good in a long oil change period.

Description

Technical Field

[0001] This invention belongs to the field of engine oil technology, and relates to an engine oil composition, its preparation method and application. Background Technology

[0002] Modern engines are evolving towards smaller size, higher power density (higher specific power), and higher torque at low speeds. This results in higher operating temperatures and heavier loads, specifically higher local operating temperatures and peak pressures. Consequently, unprecedentedly stringent requirements are placed on engine oils: they must simultaneously meet excellent high-temperature cleaning properties, anti-wear protection, oxidation resistance, and long-term durability at lower viscosity grades. Reducing oil viscosity is one of the most direct and effective ways to reduce fluid friction and improve fuel economy; however, higher viscosity grades result in thicker oil films and better lubrication protection. Therefore, lower viscosity grades inevitably lead to thinner oil films under high-temperature, high-shear (HTHS) conditions, making them more susceptible to wear, scratches, and even adhesion failure.

[0003] Currently, existing technologies mainly address this contradiction by optimizing base oils or adding additives, but significant shortcomings remain. For example, CN113174285A discloses the formulation of Group III base oils and / or PAO base oils—two specific types of base oils—with other components (especially specific types of viscosity index improvers with specific comb-like structures), exhibiting synergistic effects that balance bearing wear resistance and fuel efficiency, while also meeting the engine oil requirements under harsh wear environments. However, these base oils themselves lack sufficient extreme pressure anti-wear properties, and in ultra-low viscosity formulations, the strength of the physically adsorbed film they form is insufficient to cope with extremely high surface loads. Furthermore, balancing their low-temperature performance with dissolving additives also faces challenges.

[0004] Therefore, developing an engine oil composition with low viscosity grade, excellent oxidation and wear resistance, that can significantly reduce engine oil consumption and has an ultra-long oil change interval remains an urgent technical problem to be solved in this field. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide an engine oil composition, its preparation method, and its application. The engine oil composition has a low viscosity grade, which can significantly reduce engine oil consumption and provide good fuel economy. At the same time, it has excellent oxidation resistance and anti-wear properties, which can effectively extend the service life of the engine oil and provide an ultra-long mileage oil change interval. Furthermore, it has low phosphorus, sulfur, and ash content and good compatibility with aftertreatment during the long oil change interval.

[0006] To achieve this objective, the present invention adopts the following technical solution: In a first aspect, the present invention provides an engine oil composition comprising the following raw materials in weight percentages: Base oil 70-85%; Viscosity indicator 3~15%; Friction modifier 0.1~4%; Engine oil additives 5-20%; Pour point depressant 0.1-1%; The base oils include CTL base oils and pentaerythritol ester base oils.

[0007] The engine oil composition provided by this invention includes a specific amount of base oil, viscosity indicator, friction modifier, engine oil compounding agent, and pour point depressant. The base oil includes CTL base oil and pentaerythritol ester base oil. By selecting CTL base oil and pentaerythritol ester base oil for compounding, the low-temperature performance and oxidation resistance of the resulting engine oil composition can be significantly improved. Furthermore, it allows various additives (viscosity indicator, friction modifier, engine oil compounding agent, and pour point depressant) to dissolve stably in the base oil, exhibiting excellent additive compatibility. This maximizes the performance of various additives, resulting in a low-viscosity engine oil composition that significantly reduces engine fuel consumption, provides good fuel economy, and exhibits excellent oxidation and anti-wear properties, effectively extending the service life of the engine oil. Simultaneously, the content of phosphorus, sulfur, and ash is reduced, and it has good compatibility with aftertreatment during long oil change intervals.

[0008] The base oil may contain 70%, 72%, 74%, 76%, 78%, 80%, 82%, or 85% by mass, etc.

[0009] The viscosity indicator may have a mass percentage of 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 12%, 14%, or 15%, etc.

[0010] The mass percentage of the friction modifier can be 0.1%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, or 4%, etc.

[0011] The mass percentage of the engine oil compound can be 5%, 7%, 9%, 11%, 13%, 15%, 17%, 19%, or 20%, etc.

[0012] The mass percentage of the pour point depressant can be 0.1%, 0.2%, 0.4%, 0.6%, 0.8%, or 1%, etc.

[0013] Preferably, the mass ratio of the CTL base oil to the pentaerythritol ester base oil is (90~95):(5~10), for example, 90:10, 91:9, 92:8, 93:7, 94:6 or 95:5, etc.

[0014] Preferably, the CTL base oil includes CTL4 base oil, CTL6 base oil and CTL8 base oil.

[0015] Preferably, the mass ratio of the CTL4 base oil, CTL6 base oil and CTL8 base oil is (4~6):(2~4):1, for example 4:2:1, 4.5:2.5:1, 5:3:1, 5.5:3.5:1 or 6:4:1, etc.

[0016] Preferably, the pentaerythritol ester base oil has a pour point ≥ -55°C, such as -55°C, -52°C, -50°C, -48°C, -45°C, -42°C, or -40°C.

[0017] Preferably, the pentaerythritol ester base oil has a viscosity index >135, such as 135, 140, 145, 150, 155, 160, 165, 170, 175 or 180.

[0018] Preferably, the friction modifier comprises a WO3-La2O3 / SiC@PEI composite material and 2,4,6-tris(dimethylamino)triazine; wherein WO3 is tungsten trioxide, La2O3 is lanthanum trioxide, SiC is silicon carbide, and PEI is polyethyleneimine.

[0019] As a preferred technical solution of the present invention, a WO3-La2O3 / SiC@PEI composite material is further compounded with a 2,4,6-tris(dimethylamino)triazine binary system. On one hand, the PEI in the WO3-La2O3 / SiC@PEI composite material has a certain adsorption effect on anti-wear substances (WO3 and La2O3), enabling the anti-wear substances to be uniformly and firmly adsorbed onto the SiC carrier surface, thereby achieving high dispersion of anti-wear particles on the carrier surface and fully utilizing the anti-wear effect. On the other hand, the PEI further enhances the anti-wear effect by... The encapsulation process greatly enhances its solubility in base oils and effectively prevents nanoparticle aggregation. On the other hand, the 2,4,6-tris(dimethylamino)triazine is a polynitrogen heterocyclic compound that combines good anti-wear and friction-reducing properties, thermal stability, and oxidation resistance. It also does not contain phosphorus, sulfur, or ash, which is beneficial for achieving ultra-long oil change intervals in engine oils. When the WO3-La2O3 / SiC@PEI composite material is compounded with the 2,4,6-tris(dimethylamino)triazine binary system, the two exhibit a good synergistic effect and achieve a significant friction-reducing effect.

[0020] Preferably, the mass ratio of the WO3-La2O3 / SiC@PEI composite material to 2,4,6-tris(dimethylamino)triazine is (0.01~35):(65~99.99), for example, 0.01:99.99, 0.05:99.95, 0.1:99.9, 0.5:99.5, 1:99, 5:95, 10:90, 15:85, 20:80, 25:75, 30:70 or 35:65, etc.

[0021] Preferably, the WO3 mass percentage in the WO3-La2O3 / SiC@PEI composite material is 10-30%, for example, 10%, 12%, 14%, 16%, 18%, 20%, 22%, 24%, 26%, 28%, or 30%.

[0022] Preferably, the mass percentage of La2O3 in the WO3-La2O3 / SiC@PEI composite material is 5-25%, such as 5%, 7%, 9%, 11%, 13%, 15%, 17%, 19%, 21%, 23%, or 25%.

[0023] Preferably, the WO3-La2O3 / SiC@PEI composite material is prepared by the following method, which includes the following steps: (A1) The SiC particles are activated to obtain activated SiC particles; (A2) The activated SiC particles obtained in step (A1) are added to a PEI aqueous solution for mixing and then dried to obtain a SiC@PEI composite carrier; (A3) Combine La(NO3)3•6H2O and (NH4) 10 W 12 O 41 • A mixture of 5H2O and water is mixed with the SiC@PEI composite carrier obtained in step (A2), and then subjected to heat treatment and calcination to obtain the WO3-La2O3 / SiC@PEI composite material.

[0024] Preferably, the average particle size of the SiC particles in step (A1) is 80~100 mesh, such as 80 mesh, 82 mesh, 84 mesh, 86 mesh, 88 mesh, 90 mesh, 92 mesh, 94 mesh, 96 mesh, 98 mesh or 100 mesh.

[0025] Preferably, the activation treatment in step (A1) is carried out in a muffle furnace.

[0026] Preferably, the activation treatment temperature in step (A1) is 500~600℃, such as 500℃, 510℃, 520℃, 530℃, 540℃, 550℃, 560℃, 570℃, 580℃, 590℃ or 600℃.

[0027] Preferably, the activation treatment time in step (A1) is 2 to 4 hours, such as 2 hours, 2.2 hours, 2.4 hours, 2.6 hours, 2.8 hours, 3 hours, 3.2 hours, 3.4 hours, 3.6 hours, 3.8 hours, or 4 hours.

[0028] Preferably, the molar concentration of PEI in the PEI aqueous solution in step (A2) is 0.005~0.02 mmol / L, such as 0.005 mmol / L, 0.007 mmol / L, 0.009 mmol / L, 0.01 mmol / L, 0.012 mmol / L, 0.014 mmol / L, 0.016 mmol / L, 0.018 mmol / L, or 0.02 mmol / L.

[0029] Preferably, the pH value of the PEI aqueous solution in step (A2) is 9 to 11, such as 9, 9.2, 9.4, 9.6, 9.8, 10, 10.2, 10.4, 10.6, 10.8 or 11.

[0030] Preferably, based on a volume of 100 mL of the PEI aqueous solution in step (A2), the amount of activated SiC particles added in step (A2) is 2~4 g, for example, 2 g, 2.2 g, 2.4 g, 2.6 g, 2.8 g, 3 g, 3.2 g, 3.4 g, 3.6 g, 3.8 g, or 4 g, etc.

[0031] Preferably, the mixing temperature in step (A2) is 30~40℃, such as 30℃, 31℃, 32℃, 33℃, 34℃, 35℃, 36℃, 37℃, 38℃, 39℃ or 40℃.

[0032] Preferably, the mixing time in step (A2) is 15 to 20 hours, such as 15 hours, 15.5 hours, 16 hours, 16.5 hours, 17 hours, 17.5 hours, 18 hours, 18.5 hours, 19 hours, 19.5 hours, or 20 hours.

[0033] Preferably, based on the amount of water used in step (A3) being 100 mL, the amount of La(NO3)3•6H2O added is 0.1~0.5 g, for example, 0.1 g, 0.15 g, 0.2 g, 0.25 g, 0.3 g, 0.35 g, 0.4 g, 0.45 g, or 0.5 g.

[0034] Preferably, based on the amount of water used in step (A3) being 100 mL, the (NH4) 10 W 12 O41 • The amount of 5H2O used is 0.3~0.8 g, for example 0.3 g, 0.35 g, 0.4 g, 0.45 g, 0.5 g, 0.55 g, 0.6 g, 0.65 g, 0.7 g, 0.75 g or 0.8 g, etc.

[0035] Preferably, the pH value of the mixture in step (A3) is 8 to 10, such as 8, 8.2, 8.4, 8.6, 8.8, 9, 9.2, 9.4, 9.6, 9.8 or 10.

[0036] Preferably, based on the amount of the mixture in step (A3) being 100 mL, the amount of the SiC@PEI composite carrier in step (A3) is 1~5 g, for example, 1 g, 1.5 g, 2 g, 2.5 g, 3 g, 3.5 g, 4 g, 4.5 g or 5 g, etc.

[0037] Preferably, the heat treatment temperature in step (A3) is 150~180℃, such as 150℃, 155℃, 160℃, 165℃, 170℃, 175℃ or 180℃.

[0038] Preferably, the heat treatment in step (A3) ends when the material is evaporated to dryness.

[0039] Preferably, the calcination temperature in step (A3) is 350~450℃, such as 350℃, 360℃, 370℃, 380℃, 390℃, 400℃, 410℃, 420℃, 430℃, 440℃ or 450℃.

[0040] Preferably, the calcination time in step (A3) is 2 to 4 hours, such as 2 hours, 2.2 hours, 2.4 hours, 2.6 hours, 2.8 hours, 3 hours, 3.2 hours, 3.4 hours, 3.6 hours, 3.8 hours, or 4 hours.

[0041] Preferably, the viscosity indicator comprises a dispersed ethylene-propylene copolymer and a comb polymer.

[0042] Preferably, the mass ratio of the dispersed ethylene propylene copolymer to the comb polymer is (75~85):(15~25), for example, 75:25, 76:24, 77:23, 78:22, 79:21, 80:20, 81:19, 82:18, 83:17, 84:16 or 85:15, etc.

[0043] Preferably, the engine oil compound includes calcium alkylphenolate sulfide, magnesium alkyl salicylate, boronized succinimide, zinc thiophosphate di-secondary alkyl ester, octadecyl alcohol ester of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, N,N-di(2-ethylhexyl)-methyl-1H-benzotriazole-1-methylamine, and methyl silicone oil ester.

[0044] Preferably, the pour point depressant comprises a poly-α-olefin.

[0045] Preferably, the viscosity grade of the engine oil composition is 0W-20 or 5W-20.

[0046] Preferably, the oil change interval of the engine oil composition is 100,000 to 300,000 kilometers, such as 100,000 kilometers, 120,000 kilometers, 140,000 kilometers, 160,000 kilometers, 180,000 kilometers, 200,000 kilometers, 220,000 kilometers, 240,000 kilometers, 260,000 kilometers, 280,000 kilometers, or 300,000 kilometers.

[0047] In a second aspect, the present invention provides a method for preparing the engine oil composition as described in the first aspect, the method comprising the following steps: (1) Mix CTL base oil and pentaerythritol ester base oil to obtain base oil; (2) The base oil, viscosity indicator, engine oil compound and pour point depressant obtained in step (1) are mixed to obtain a mixed oil; (3) The mixed oil obtained in step (2) and the friction modifier are mixed to obtain the engine oil composition.

[0048] Preferably, the mixing temperature in step (1) is 65~70℃, such as 65℃, 66℃, 67℃, 68℃, 69℃ or 70℃.

[0049] Preferably, the mixing time in step (1) is 2 to 3 hours, such as 2 hours, 2.2 hours, 2.4 hours, 2.6 hours, 2.8 hours or 3 hours.

[0050] Preferably, the mixing temperature in step (2) is 65~70℃, such as 65℃, 66℃, 67℃, 68℃, 69℃ or 70℃.

[0051] Preferably, the mixing time in step (2) is 2 to 3 hours, such as 2 hours, 2.2 hours, 2.4 hours, 2.6 hours, 2.8 hours or 3 hours.

[0052] Preferably, the mixing temperature in step (3) is 75~80℃, such as 75℃, 76℃, 77℃, 78℃, 79℃ or 80℃.

[0053] Preferably, the mixing time in step (3) is 2 to 3 hours, such as 2 hours, 2.1 hours, 2.2 hours, 2.3 hours, 2.4 hours, 2.5 hours, 2.6 hours, 2.7 hours, 2.8 hours, 2.9 hours or 3 hours.

[0054] Thirdly, the present invention provides the application of the engine oil composition as described in the first aspect in an automobile.

[0055] Compared with the prior art, the present invention has the following beneficial effects: (1) The engine oil composition provided by the present invention, by selecting CTL base oil and pentaerythritol ester base oil for compounding, significantly improves the low-temperature performance and antioxidant performance of the obtained engine oil composition, and also enables various additives to dissolve stably in the base oil, exhibiting excellent additive compatibility, so that the final obtained engine oil composition has a low viscosity grade (viscosity grade of 0W-20 or 5W-20), high temperature and high shear (150℃, 106 s) -1 The lower viscosity is not less than 2.6 mPa•s, and the kinematic viscosity at 100℃ is in the range of 6.9~9.3 mm. 2 / s), which can significantly reduce engine oil consumption, resulting in good fuel economy. The oil also has excellent oxidation and anti-wear properties, effectively extending the service life of the engine oil. Furthermore, the content of phosphorus, sulfur, and ash is reduced, and it has good compatibility with aftertreatment during long oil change intervals. (2) Furthermore, the friction modifier of the engine oil composition provided by the present invention is a compound of WO3-La2O3 / SiC@PEI composite material and 2,4,6-tris(dimethylamino)triazine. The two exhibit a good synergistic effect and have a significant friction reduction effect. It can further improve the anti-wear and friction reduction properties, thermal stability and antioxidant properties of the obtained engine oil composition. It does not contain phosphorus, sulfur and ash, which is conducive to achieving an ultra-long oil change interval for engine oil. Detailed Implementation

[0056] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention.

[0057] In this invention, detailed information on some of the raw materials involved in the following embodiments and comparative examples is shown below: (1) Pentaerythritol base oil: pour point not less than -55℃, viscosity index greater than 135, grade PE343; (2) 2,4,6-Tris(dimethylamino)triazine: CAS number is 645-05-6, molecular weight is 210.28; (3) Dispersed ethylene-propylene copolymer: purchased from Mitsubishi Chemical, Japan, brand name Lucant DC-3000; (4) Comb polymer: purchased from Evonik, Germany, brand name VISCOPLEX 12-199; (5) Medium alkali number alkylphenol calcium sulfide: purchased from Evonik Germany, brand name RF1121; (6) High-base-value alkyl salicylate magnesium: purchased from Evonik Germany, brand name RHY109M; (7) Borated succinimide: brand name T154B; (8) Zinc sulfide di-secondary alkyl phosphate: grade RF2205; (9) 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate n-octadecyl alcohol ester: grade RF2205; (10) N,N-Di(2-ethylhexyl)-methyl-1H-benzotriazole-1-methylamine: brand name Cuvan303; (11) Methyl silicone oil: grade T903; (12) Poly-α-olefin: purchased from Mobil in the United States, grade T803B.

[0058] Preparation Example 1 A WO3-La2O3 / SiC@PEI composite material, the preparation method of which includes the following steps: (1) After mechanically crushing SiC, it is sieved and SiC particles with an average particle size of 100 mesh are taken and washed with a mixture of ethanol and water (volume ratio of 1:1) until the upper layer of the washing liquid is clear. After filtration, it is placed in an oven at 120°C overnight. The dried SiC particles are placed in a muffle furnace and calcined at 550°C for 3 h. The particles are collected and sealed to obtain activated SiC particles. (2) Prepare 100 mL of PEI aqueous solution with a molar concentration of 0.01 mmol / L, add sodium hydroxide solution to adjust its pH to 10, then add 3 g of the activated SiC particles obtained in step (1), stir at 35℃ for 18 h, and dry at 110℃ overnight to obtain SiC@PEI composite carrier; (3) Mix 0.2 g of La(NO3)3•6H2O and 0.62 g of (NH4) 10 W 12 O 41• 5H2O was dissolved in 100 mL of deionized water to obtain a mixture. The pH of the mixture was adjusted to 9 with ammonia water. The adjustment process was continuously stirred. After stirring for 2 h, 3 g of the SiC@PEI composite carrier obtained in step (2) was added. The mixture was heated in an oil bath at 165℃ until it was naturally dried. After rapid drying, it was washed with deionized water and then calcined at 400℃ for 3 h. After drying, it was sealed and stored to obtain the WO3-La2O3 / SiC@PEI composite material.

[0059] Preparation Example 2 A WO3 / SiC@PEI composite material, which differs from Preparation Example 1 only in that La(NO3)3•6H2O is not added in step (3), while the other substances, amounts and preparation methods are the same as in Preparation Example 1.

[0060] Preparation Example 3 A La2O3 / SiC@PEI composite material, which differs from Preparation Example 1 only in that (NH4) is not added in step (3). 10 W 12 O 41 •5H2O, and the other substances, amounts and preparation methods are the same as in Preparation Example 1.

[0061] Preparation Example 4 A WO3-La2O3 / SiC composite material, the preparation method of which includes the following steps: (1) After mechanically crushing SiC, it is sieved and SiC particles with an average particle size of 100 mesh are taken and washed with a mixture of ethanol and water (volume ratio of 1:1) until the upper layer of the washing liquid is clear. After filtration, it is placed in an oven at 120°C overnight. The dried SiC particles are placed in a muffle furnace and calcined at 550°C for 3 h. The particles are collected and sealed to obtain activated SiC particles. (2) Mix 0.2 g of La(NO3)3•6H2O and 0.62 g of (NH4) 10 W 12 O 41 • 5H2O was dissolved in 100 mL of deionized water to obtain a mixture. The pH of the mixture was adjusted to 9 with ammonia water. The adjustment process was continuously stirred. After stirring for 2 h, 3 g of the activated SiC particles obtained in step (1) were added. The mixture was heated in an oil bath at 165 °C until it was naturally dried. After rapid drying, it was washed with deionized water and then calcined at 400 °C for 3 h. After drying, it was sealed and stored to obtain the WO3-La2O3 / SiC composite material.

[0062] Example 1 An engine oil composition comprising the following raw materials in weight percentages: Base oil 70%; Viscosity indicator 8.5%; Friction modifier 4%; Engine oil additive 17%; Pour point depressant 0.5%; The base oil is composed of CTL base oil and pentaerythritol ester base oil in a mass ratio of 9:1, wherein the CTL base oil is composed of CTL4 base oil, CTL6 base oil and CTL8 base oil in a mass ratio of 5:3:1. The viscosity indicator is composed of a dispersed ethylene-propylene copolymer and a comb-like polymer in a mass ratio of 8.3:1.7; The friction modifier is composed of a WO3-La2O3 / SiC@PEI composite material (Preparation Example 1) in a mass ratio of 3:7 and 2,4,6-tris(dimethylamino)triazine; The engine oil compound is composed of medium-base-value alkylphenol calcium sulfate, high-base-value alkyl salicylate magnesium, boronized succinimide, di-secondary alkyl zinc thiophosphate, octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, N,N-di(2-ethylhexyl)-methyl-1H-benzotriazole-1-methylamine, and methyl silicone oil ester in a mass ratio of 26:14:26:10:18:4:2. The pour point depressant is a polyα-olefin; The method for preparing the engine oil composition provided in this embodiment includes the following steps: (1) Add CTL base oil and pentaerythritol ester base oil to a blending vessel and stir and mix at 70°C for 2.5 h to obtain base oil; (2) Add viscosity indicator, engine oil compound and pour point depressant to the mixing tank, and continue to stir and mix at 70°C for 2.5 h to obtain mixed oil; (3) Add the friction modifier to the mixing vessel, continue stirring and mixing at 80°C for 2.5 h, and let stand for 3 h to obtain the engine oil composition.

[0063] Example 2 An engine oil composition comprising the following raw materials in weight percentages: Base oil 75%; Viscosity indicator 7.5%; Friction modifier 3%; Engine oil additive 14%; Pour point depressant 0.5%; The base oil is composed of CTL base oil and pentaerythritol ester base oil in a mass ratio of 9.5:0.5, wherein the CTL base oil is composed of CTL4 base oil, CTL6 base oil and CTL8 base oil in a mass ratio of 5:3:1. The viscosity indicator is composed of a dispersed ethylene-propylene copolymer and a comb-like polymer in a mass ratio of 7.5:2.5; The friction modifier is composed of a WO3-La2O3 / SiC@PEI composite material (Preparation Example 1) in a mass ratio of 2:8 and 2,4,6-tris(dimethylamino)triazine; The engine oil compound is composed of medium-base-value alkylphenol calcium sulfate, high-base-value alkyl salicylate magnesium, boronized succinimide, di-secondary alkyl zinc thiophosphate, octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, N,N-di(2-ethylhexyl)-methyl-1H-benzotriazole-1-methylamine, and methyl silicone oil ester in a mass ratio of 26:14:26:10:18:4:2. The pour point depressant is a polyα-olefin; The preparation method of the engine oil composition provided in Example 2 is the same as that in Example 1.

[0064] Example 3 An engine oil composition comprising the following raw materials in weight percentages: Base oil 73.5%; Viscosity indicator 8%; Friction modifier 2%; Engine oil additive 16%; Pour point depressant 0.5%; The base oil is composed of CTL base oil and pentaerythritol ester base oil in a mass ratio of 9.3:0.7, wherein the CTL base oil is composed of CTL4 base oil, CTL6 base oil and CTL8 base oil in a mass ratio of 5:3:1. The viscosity indicator is composed of a dispersed ethylene-propylene copolymer and a comb-like polymer in a mass ratio of 8.5:1.5; The friction modifier is composed of a WO3-La2O3 / SiC@PEI composite material (Preparation Example 1) in a mass ratio of 1:9 and 2,4,6-tris(dimethylamino)triazine; The engine oil compound is composed of medium-base-value alkylphenol calcium sulfate, high-base-value alkyl salicylate magnesium, boronized succinimide, di-secondary alkyl zinc thiophosphate, octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, N,N-di(2-ethylhexyl)-methyl-1H-benzotriazole-1-methylamine, and methyl silicone oil ester in a mass ratio of 26:14:26:10:18:4:2. The pour point depressant is a polyα-olefin; The preparation method of the engine oil composition provided in Example 3 is the same as that in Example 1.

[0065] Example 4 An engine oil composition comprising the following raw materials in weight percentages: Base oil 72.5%; Viscosity indicator 7%; Friction modifier 1%; Engine oil additive 19%; Pour point depressant 0.5%; The base oil is composed of CTL base oil and pentaerythritol ester base oil in a mass ratio of 9.1:0.9, wherein the CTL base oil is composed of CTL4 base oil, CTL6 base oil and CTL8 base oil in a mass ratio of 5:3:1. The viscosity indicator is composed of a dispersed ethylene-propylene copolymer and a comb-like polymer in a mass ratio of 8.2:1.8; The friction modifier is composed of a WO3-La2O3 / SiC@PEI composite material (Preparation Example 1) with a mass ratio of 1.2:8.8 and 2,4,6-tris(dimethylamino)triazine; The engine oil compound is composed of medium-base-value alkylphenol calcium sulfate, high-base-value alkyl salicylate magnesium, boronized succinimide, di-secondary alkyl zinc thiophosphate, octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, N,N-di(2-ethylhexyl)-methyl-1H-benzotriazole-1-methylamine, and methyl silicone oil ester in a mass ratio of 26:14:26:10:18:4:2. The pour point depressant is a polyα-olefin; The preparation method of the engine oil composition provided in Example 4 is the same as that in Example 1.

[0066] Example 5 An engine oil composition differs from Example 1 only in that an equal amount of the WO3 / SiC@PEI composite material obtained in Preparation Example 2 is used to replace the WO3-La2O3 / SiC@PEI composite material obtained in Preparation Example 1. All other substances, amounts, and preparation methods are the same as in Example 1.

[0067] Example 6 An engine oil composition differs from Example 1 only in that an equal amount of the La2O3 / SiC@PEI composite material obtained in Preparation Example 3 is used to replace the WO3-La2O3 / SiC@PEI composite material obtained in Preparation Example 1. All other substances, amounts, and preparation methods are the same as in Example 1.

[0068] Example 7 An engine oil composition differs from Example 1 only in that an equal amount of the WO3-La2O3 / SiC composite material obtained in Preparation Example 4 is used to replace the WO3-La2O3 / SiC@PEI composite material obtained in Preparation Example 1. All other substances, amounts, and preparation methods are the same as in Example 1.

[0069] Example 8 An engine oil composition differs from Example 1 only in that the friction modifier is composed of 100% WO3-La2O3 / SiC@PEI composite material, while the other substances, amounts, and preparation methods are the same as in Example 1.

[0070] Example 9 An engine oil composition differs from Example 1 only in that the friction modifier consists of 100% 2,4,6-tris(dimethylamino)triazine, while the other substances, amounts, and preparation methods are the same as in Example 1.

[0071] Comparative Example 1 A reference engine oil with a viscosity grade of 10W-40.

[0072] Comparative Example 2 An engine oil composition differs from Example 1 only in that the base oil is composed of 100% CTL base oil and no pentaerythritol ester base oil is added; all other substances, amounts, and preparation methods are the same as in Example 1.

[0073] Comparative Example 3 An engine oil composition differs from Example 1 only in that the base oil is composed of 100% pentaerythritol ester base oil, without the addition of CTL base oil, while the other substances, amounts, and preparation methods are the same as in Example 1.

[0074] Comparative Example 4 An engine oil composition differs from Example 1 only in that the total amount of friction modifier added is reduced to 0.05%, and the reduced amount is proportionally added to other components to keep the mass ratio of other components unchanged. The preparation method is the same as in Example 1.

[0075] Performance testing: (1) Oxidation induction period: The test was conducted according to the test method provided by ASTM D6186; (2) High-temperature high-shear viscosity: obtained by testing according to the test method provided by ASTM D4683; (3) Average friction coefficient of SRV, wear depth of cylinder liner corresponding to SRV first ring and wear depth of cylinder liner corresponding to SRV second ring: obtained by testing according to the test method provided by ASTM D6425; (4) Vehicle fuel consumption reduction rate: The vehicle fuel consumption reduction rate is calculated as (baseline fuel consumption - fuel consumption after test) / baseline fuel consumption × 100%, where the baseline fuel consumption is the vehicle fuel consumption using the engine oil composition provided in Comparative Example 1.

[0076] The engine oil compositions provided in Examples 1-9 and Comparative Examples 1-4 were tested according to the above test methods, and the test results are shown in Table 1. Table 1 According to the data in Table 1: The engine oil compositions provided in Examples 1-9 all have a long oxidation induction period, indicating good antioxidant properties. Furthermore, the average friction coefficient of the SRV, the cylinder liner wear depth corresponding to the first SRV ring, and the cylinder liner wear depth corresponding to the second SRV ring are all low, indicating good anti-wear and friction reduction properties. At the same time, the overall vehicle fuel consumption is reduced.

[0077] Compared with Example 1, the reference engine oil provided in Comparative Example 1 has a shorter oxidation induction period, indicating poorer oxidation resistance. At the same time, the average friction coefficient of SRV, the cylinder liner wear depth corresponding to the first SRV ring, and the cylinder liner wear depth corresponding to the second SRV ring are all higher, indicating poorer anti-wear and friction reduction properties, and relatively higher overall vehicle fuel consumption.

[0078] Compared to Example 1, the engine oil composition provided in Comparative Example 2, which uses 100% CTL base oil as the base oil, also resulted in a shorter oxidation induction period, an increased average friction coefficient of the SRV, an increased cylinder liner wear depth corresponding to the SRV first ring, and an increased cylinder liner wear depth corresponding to the SRV second ring, leading to poorer oxidation resistance and anti-wear and friction reduction properties. In contrast, the engine oil composition provided in Comparative Example 3, which uses 100% pentaerythritol ester base oil as the base oil, resulted in higher costs.

[0079] Compared with Example 1, the total amount of friction modifier added in the engine oil composition provided in Comparative Example 4 is lower, which also leads to an increase in the average friction coefficient of SRV, the cylinder liner wear depth corresponding to the first SRV ring and the cylinder liner wear depth corresponding to the second SRV ring, and a decrease in anti-wear and friction reduction properties.

[0080] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. An engine oil composition, characterized in that, The engine oil composition comprises the following raw materials in the indicated mass percentages: Base oil 70-85%; Viscosity indicator 3~15%; Friction modifier 0.1~4%; Engine oil additives 5-20%; Pour point depressant 0.1-1%; The base oils include CTL base oils and pentaerythritol ester base oils.

2. The engine oil composition according to claim 1, characterized in that, The mass ratio of CTL base oil to pentaerythritol ester base oil is (90~95):(5~10); Preferably, the CTL base oil includes CTL4 base oil, CTL6 base oil, and CTL8 base oil; Preferably, the mass ratio of the CTL4 base oil, CTL6 base oil and CTL8 base oil is (4~6):(2~4):1; Preferably, the pentaerythritol ester base oil has a pour point ≥ -55°C and a viscosity index > 135.

3. The engine oil composition according to claim 1 or 2, characterized in that, The friction modifier comprises WO3-La2O3 / SiC@PEI composite material and 2,4,6-tris(dimethylamino)triazine; Preferably, the mass ratio of the WO3-La2O3 / SiC@PEI composite material to 2,4,6-tris(dimethylamino)triazine is (0.01~35):(65~99.99); Preferably, the WO3 content in the WO3-La2O3 / SiC@PEI composite material is 10-30% by mass. Preferably, the mass percentage of La2O3 in the WO3-La2O3 / SiC@PEI composite material is 5-25%; Preferably, the WO3-La2O3 / SiC@PEI composite material is prepared by the following method, which includes the following steps: (A1) The SiC particles are activated to obtain activated SiC particles; (A2) The activated SiC particles obtained in step (A1) are added to a PEI aqueous solution for mixing and then dried to obtain a SiC@PEI composite carrier; (A3) Combine La(NO3)3·6H2O and (NH4) 10 W 12 O 41 The mixture obtained by dissolving 5H2O in water is mixed with the SiC@PEI composite carrier obtained in step (A2), and after heat treatment and calcination, the WO3-La2O3 / SiC@PEI composite material is obtained. Preferably, the activation treatment in step (A1) is performed at a temperature of 500-600°C for 2-4 hours. Preferably, the pH value of the PEI aqueous solution in step (A2) is 9-11; Preferably, based on a volume of 100 mL for the PEI aqueous solution described in step (A2), the amount of activated SiC particles added in step (A2) is 2-4 g. Preferably, the mixing temperature in step (A2) is 30~40℃ and the time is 15~20 h; Preferably, the pH value of the mixture in step (A3) is 8-10; Preferably, based on the amount of the mixture in step (A3) being 100 mL, the amount of the SiC@PEI composite carrier in step (A3) is 1~5 g; Preferably, the heat treatment temperature in step (A3) is 150~180℃; Preferably, the heat treatment in step (A3) ends when the material is evaporated to dryness; Preferably, the calcination treatment in step (A3) is carried out at a temperature of 350~450℃ for 2~4 hours.

4. The engine oil composition according to any one of claims 1 to 3, characterized in that, The viscosity indicator comprises a dispersed ethylene-propylene copolymer and a comb-like polymer; Preferably, the mass ratio of the dispersed ethylene propylene copolymer to the comb polymer is (75~85):(15~25).

5. The engine oil composition according to any one of claims 1 to 4, characterized in that, The engine oil compound comprises a combination of calcium alkylphenolate sulfide, magnesium alkyl salicylate, boronized succinimide, zinc thiophosphate di-secondary alkyl ester, octadecyl alcohol ester of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, N,N-di(2-ethylhexyl)-methyl-1H-benzotriazole-1-methylamine, and methyl silicone oil ester.

6. The engine oil composition according to any one of claims 1 to 5, characterized in that, The pour point depressant includes poly-α-olefins.

7. The engine oil composition according to any one of claims 1 to 6, characterized in that, The viscosity grade of the engine oil composition is 0W-20 or 5W-20; Preferably, the engine oil composition has an oil change interval of 100,000 to 300,000 kilometers.

8. A method for preparing an engine oil composition according to any one of claims 1 to 7, characterized in that, The preparation method includes the following steps: (1) Mix CTL base oil and pentaerythritol ester base oil to obtain base oil; (2) The base oil, viscosity indicator, engine oil compound and pour point depressant obtained in step (1) are mixed to obtain a mixed oil; (3) The mixed oil obtained in step (2) and the friction modifier are mixed to obtain the engine oil composition.

9. The preparation method according to claim 8, characterized in that, The mixing temperature in step (1) is 65~70℃, and the time is 2~3 h; Preferably, the mixing temperature in step (2) is 65~70℃ and the time is 2~3 h; Preferably, the mixing temperature in step (3) is 75~80℃ and the time is 2~3 h.

10. The use of an engine oil composition as described in any one of claims 1 to 7 in an automobile.

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