Environment-friendly long-life engine lubricating oil

Abstract

The application belongs to the technical field of lubricating oil, and particularly relates to an environment-friendly long-life engine lubricating oil. The environment-friendly long-life engine lubricating oil comprises, by mass percentage, 10-15% of synthetic ester, 0.2-3% of anti-wear agent, 0.4-0.8% of MOF composite material, 8-13% of composite additive, 0.1-5% of viscosity index improver, 0.1-0.4% of pour point depressant, 0.001-0.01% of anti-foaming agent and the rest of poly-alpha olefin. The methyl benzotriazole is introduced into the MOF material to improve the dispersibility of the MOF material in the lubricating oil. The methyl benzotriazole can form a protective film on the metal surface, isolating the direct contact of the friction pair, thereby achieving high-efficiency anti-wear; the spherical molybdenum disulfide can convert sliding friction into rolling friction, reducing the friction coefficient; the nano MOF composite material can enter the recessed part of the friction scratch to produce repair and protection, and the three synergistically make the MOF composite material of the application have good friction-reducing and anti-wear effects.

Description

Technical Field

[0001] This invention belongs to the field of lubricating oil technology, specifically relating to an environmentally friendly, long-life engine lubricating oil. Background Technology

[0002] In the field of modern automotive and industrial power equipment, the engine, as the core power output component, directly determines the overall performance of the machine through its operational reliability and service life. Engine lubricating oil, as a crucial medium ensuring the stable operation of the power system, plays a vital role in forming a lubricating film between high-speed relative moving parts such as crankshaft bearings, pistons and cylinder walls, and camshafts and tappets. It also possesses multiple functions including cooling and heat dissipation, cleaning and dispersing carbon deposits, sealing against leaks, and preventing rust and corrosion. It is a core element for maintaining the long-term efficient operation of the engine. As engine technology iterates and upgrades towards higher power density, higher load, and longer oil change intervals, the market places more stringent demands on the anti-wear and friction-reducing properties and service life of lubricating oils. Engine lubricating oil mainly consists of two parts: base oil and additives. Base oil is the main component, while additives mainly include detergents, dispersants, friction-reducing and anti-wear agents, antioxidants, and pour point depressants. Currently, friction-reducing and anti-wear agents mainly fall into two categories: oil-soluble additives, such as oiliness agents containing polar groups, fatty acids, organometallic compounds, and organomolybdenum compounds; and solid additives, such as graphite, molybdenum disulfide, tungsten disulfide, and boron nitride. These friction-reducing and anti-wear agents have good friction-reducing and anti-wear properties, which can increase the service life of oils. However, these friction-reducing and anti-wear agents are released and consumed rapidly in the early stages of oil use. In the middle and later stages of the oil change cycle, the concentration of effective anti-wear components in the oil has dropped below the critical value, and it can no longer provide reliable protection for the friction pairs under high-load conditions. Therefore, it is necessary to control the release rate of friction-reducing and anti-wear agents in order to improve the service life of lubricating oils. Summary of the Invention

[0003] The purpose of this invention is to provide an environmentally friendly, long-life engine lubricant to solve the technical problem of concentrated release of friction-reducing and anti-wear agents in the early stages of oil use.

[0004] To achieve the above objectives, the technical solution of the present invention is as follows: An environmentally friendly, long-life engine lubricant comprises, by weight percentage: 10-15% synthetic ester, 0.2-3% anti-wear agent, 0.4-0.8% MOF composite material, 8-13% composite additive, 0.1-5% viscosity index improver, 0.1-0.4% pour point depressant, 0.001-0.01% antifoaming agent, and the balance being polyalphaolefin.

[0005] Furthermore, the preparation method of the MOF composite material is as follows: dissolve methylbenzotriazole in solvent one to obtain an immersion solution, immerse ZIF-7 in the immersion solution, filter, and dry to obtain the final product.

[0006] Furthermore, the solvent is methanol, the concentration of methylbenzotriazole in the soaking solution is 1-3 mg / mL, and the mass ratio of ZIF-7 to methylbenzotriazole is 1:0.5-1.5.

[0007] Furthermore, the soaking temperature is 30–45 °C, and the soaking time is 48–72 h.

[0008] Furthermore, the method for preparing the anti-wear agent is as follows: menthol is mixed with long-chain fatty acids to obtain a eutectic solvent, the eutectic solvent is dissolved in solvent two to obtain a mixture, spherical porous molybdenum disulfide is placed in the mixture, ultrasonically treated, stirred and solvent two is removed, and then dried to obtain the anti-wear agent.

[0009] Furthermore, the molar ratio of menthol to long-chain fatty acid is 1:1.9 to 2.1; the long-chain fatty acid is one or more of decanoic acid and lauric acid.

[0010] Furthermore, the mass ratio of the eutectic solvent to solvent two is 1:8 to 10; the mass ratio of the eutectic solvent to spherical porous molybdenum disulfide is 3 to 4:1; the ultrasonic power is 100 to 120 W, and the time is 5 to 8 min; the stirring time is 15 to 18 h; and solvent two is methanol.

[0011] Furthermore, the synthetic ester is one or more of neopentyl glycol ester, trimethylolpropane ester, and pentaerythritol ester; the pour point depressant is polymethacrylate; the antifoaming agent is polydimethyl silicone oil; and the viscosity index improver is one or more of ethylene propylene copolymer, polyisobutylene, or polymethacrylate.

[0012] Furthermore, the composite additive includes 2-6% detergent, 1.5-2% antioxidant, and 1-5% dispersant; the detergent is one or more of sulfonate and sulfurized alkylphenol salt; the antioxidant is one or more of phenolic antioxidant and amine antioxidant; and the dispersant is polyisobutylene succinimide.

[0013] The beneficial effects of this invention are: MOF materials exhibit poor dispersibility in lubricating oils. This invention introduces methylbenzotriazole into the MOF material to improve its dispersibility in lubricating oils. Furthermore, methylbenzotriazole possesses good thermal stability, corrosion inhibition, and anti-wear properties, which can enhance the thermal stability, corrosion resistance, and anti-wear performance of the lubricating oil of this invention. The methylbenzotriazole in the MOF composite material of this invention can form a protective film on the metal surface, isolating the friction pairs from direct contact, thereby achieving highly efficient anti-wear. The spherical molybdenum disulfide can convert sliding friction into rolling friction, reducing the coefficient of friction. The nano-MOF composite material can penetrate the depressions of friction scratches to provide repair and protection. These three factors synergistically give the MOF composite material of this invention excellent friction reduction, anti-wear, and repair effects. In addition, the low-eutectic solvent adsorbed by the anti-wear agent of this invention is slowly released during lubricating oil use, avoiding rapid consumption of the friction-reducing and anti-wear agent in the early stages of lubricating oil use, thus preventing a short service life. Detailed Implementation

[0014] The following will provide further details with reference to embodiments of the present invention.

[0015] Spherical porous molybdenum disulfide was prepared using existing methods. The specific steps were as follows: 3 kg of sodium molybdate dihydrate, 2.82 kg of thiourea, and 3.9 kg of nano-silica were mixed and ultrasonically treated for 30 min, followed by reaction at 200 ℃ for 24 h. After the reaction was completed, the mixture was cooled and washed with anhydrous ethanol and deionized water to obtain an intermediate product. The intermediate product was mixed with 2 M sodium hydroxide solution and kept at 60 ℃ for 6 h. After washing and drying, the final product was obtained.

[0016] Example 1 Example 1's environmentally friendly, long-life engine lubricant comprises: 68 kg of polyalphaolefin, 14.999 kg of synthetic ester, 2 kg of anti-wear agent, 0.5 kg of MOF composite material, 6 kg of detergent, 2 kg of antioxidant, 4.1 kg of dispersant, 2 kg of viscosity index improver, 0.4 kg of pour point depressant, and 0.001 kg of antifoaming agent. The synthetic ester is pentaerythritol ester, the detergent is calcium sulfonate, the dispersant is polyisobutylene succinimide, the pour point depressant is polymethyl methacrylate, the antifoaming agent is polydimethyl silicone oil, the antioxidant is naphthylamine, and the viscosity index improver is polymethyl methacrylate.

[0017] The preparation method of MOF composite materials includes the following steps: 0.5 kg of methylbenzotriazole was dissolved in methanol to obtain a soaking solution with a concentration of 1 mg / mL. 1 kg of ZIF-7 was placed in the soaking solution and soaked at 30 ℃ for 72 h. During the soaking process, the original soaking solution was replaced with a methylbenzotriazole solution of the same concentration every 12 h. After soaking, the solution was filtered and dried to obtain the final product.

[0018] The preparation method of the anti-wear agent includes the following steps: 1.8 kg of menthol and 4.2 kg of decanoic acid were mixed to obtain a eutectic solvent. The eutectic solvent was then mixed with 48 kg of methanol to obtain a mixture. 2 kg of spherical porous molybdenum disulfide was placed in the mixture, and the mixture was ultrasonically treated at 100 W for 5 min, stirred for 18 h, and then the methanol was removed by rotary evaporation at 50 °C. The mixture was then dried at 50 °C to obtain the final product.

[0019] Example 2 Example 2's environmentally friendly, long-life engine lubricant comprises: 71 kg of polyalphaolefin, 12 kg of synthetic ester, 2.79 kg of anti-wear agent, 0.4 kg of MOF composite material, 2.5 kg of detergent, 2 kg of antioxidant, 5 kg of dispersant, 4 kg of viscosity index improver, 0.3 kg of pour point depressant, and 0.01 kg of antifoaming agent. The synthetic ester is trimethylolpropane ester, the detergent is magnesium sulfonate, the dispersant is polyisobutylene succinimide, the pour point depressant is polymethyl methacrylate, the antifoaming agent is polydimethyl silicone oil, the antioxidant is diphenylamine, and the viscosity index improver is ethylene-propylene copolymer.

[0020] The preparation method of MOF composite materials includes the following steps: 1 kg of methylbenzotriazole was dissolved in methanol to obtain a soaking solution with a concentration of 2 mg / mL. 1 kg of ZIF-7 was placed in the soaking solution and soaked at 40 °C for 60 h. During the soaking process, the original soaking solution was replaced with a methylbenzotriazole solution of the same concentration every 12 h. After soaking, the solution was filtered and dried to obtain the final product.

[0021] The preparation method of the anti-wear agent includes the following steps: 2.7 kg of menthol and 6.3 kg of decanoic acid were mixed to obtain a eutectic solvent. The eutectic solvent was then mixed with 81 kg of methanol to obtain a mixture. 2.5 kg of spherical porous molybdenum disulfide was placed in the mixture, and the mixture was ultrasonically treated at 120 W for 5 min, stirred for 15 h, and then the methanol was removed by rotary evaporation at 50 °C. The mixture was then dried at 60 °C to obtain the final product.

[0022] Example 3 Example 3's environmentally friendly, long-life engine lubricant comprises: 79.5 kg of polyalphaolefin, 10 kg of synthetic ester, 0.5 kg of anti-wear agent, 0.8 kg of MOF composite material, 5.99 kg of detergent, 1.5 kg of antioxidant, 1.1 kg of dispersant, 0.5 kg of viscosity index improver, 0.1 kg of pour point depressant, and 0.01 kg of antifoaming agent. The synthetic ester includes 3 kg of neopentyl glycol ester and 7 kg of pentaerythritol ester. The detergent is calcium sulfonate, the dispersant is polyisobutylene succinimide, the pour point depressant is polymethyl methacrylate, the antifoaming agent is polydimethyl silicone oil, the antioxidant is antioxidant 1135, and the viscosity index improver is polyisobutylene.

[0023] The preparation method of MOF composite materials includes the following steps: 1.5 kg of methylbenzotriazole was dissolved in methanol to obtain a soaking solution with a concentration of 3 mg / mL. 1 kg of ZIF-7 was placed in the soaking solution and soaked at 45 ℃ for 48 h. During the soaking process, the original soaking solution was replaced with a methylbenzotriazole solution of the same concentration every 12 h. After soaking, the solution was filtered and dried to obtain the final product.

[0024] The preparation method of the anti-wear agent includes the following steps: 0.84 kg of menthol and 2.16 kg of lauric acid were mixed to obtain a eutectic solvent. The eutectic solvent was then mixed with 30 kg of methanol to obtain a mixture. 0.75 kg of spherical porous molybdenum disulfide was placed in the mixture, and the mixture was ultrasonically treated at 100 W for 8 min, stirred for 15 h, and then the methanol was removed by rotary evaporation at 50 °C. The mixture was then dried at 55 °C to obtain the final product.

[0025] Example 4 Example 4's environmentally friendly, long-life engine lubricant comprises: 74.9 kg of polyalphaolefin, 11 kg of synthetic ester, 1 kg of anti-wear agent, 0.8 kg of MOF composite material, 5 kg of detergent, 2 kg of antioxidant, 4.89 kg of dispersant, 0.1 kg of viscosity index improver, 0.3 kg of pour point depressant, and 0.01 kg of antifoaming agent. The synthetic ester is neopentyl glycol ester, the detergent is calcium alkylphenol sulfide, the total base value is 150 mgKOH / g, the dispersant is polyisobutylene succinimide, the pour point depressant is polymethyl methacrylate, the antifoaming agent is polydimethyl silicone oil, the antioxidant is antioxidant 1135, and the viscosity index improver is ethylene-propylene copolymer.

[0026] The preparation methods of the MOF composite material and anti-wear agent in Example 4 are the same as those in Example 1.

[0027] Comparative Example 1 The environmentally friendly long-life engine lubricant of Comparative Example 1 is made from roughly the same raw materials as the environmentally friendly long-life engine lubricant of Example 1. The difference between the raw materials of the environmentally friendly long-life engine lubricant of Comparative Example 1 and Example 1 is that the environmentally friendly long-life engine lubricant of Comparative Example 1 does not contain anti-wear agents, and the mass of the MOF composite material is 2.5 kg.

[0028] Comparative Example 2 The environmentally friendly long-life engine lubricant of Comparative Example 2 has roughly the same raw materials as the environmentally friendly long-life engine lubricant of Example 1. The difference between the raw materials of the environmentally friendly long-life engine lubricant of Comparative Example 2 and Example 1 is that the environmentally friendly long-life engine lubricant of Comparative Example 2 does not contain MOF composite material, and the mass of the anti-wear agent is 2.5 kg.

[0029] Comparative Example 3 The environmentally friendly long-life engine lubricant of Comparative Example 3 is made from roughly the same raw materials as the environmentally friendly long-life engine lubricant of Example 1. The difference between the raw materials of the environmentally friendly long-life engine lubricant of Comparative Example 3 and Example 1 is that the anti-wear agent of Comparative Example 3 is molybdenum disulfide.

[0030] Comparative Example 4 The environmentally friendly long-life engine lubricant of Comparative Example 4 uses roughly the same raw materials as the environmentally friendly long-life engine lubricant of Example 1. The difference between the raw materials of Comparative Example 4 and Example 1 is that the MOF composite material of Comparative Example 4 is replaced with ZIF-7.

[0031] Experimental Example 1 Performance test Aging performance test: Oxygen was introduced into the environmentally friendly long-life engine lubricating oils of Examples 1-2 and Comparative Examples 1-4 at a flow rate of 10 L / h, and the oils were tested for 150 h at 100 °C under the catalysis of copper strips. The performance of the lubricating oils was then tested. The performance test results before the aging test are shown in Table 1, and the performance test results after the aging test are shown in Table 2.

[0032] Wear scar diameter: Tested according to ASTM D4172-21.

[0033] Four-ball load capacity: tested according to GB / T 3142-2019.

[0034] Maximum non-seize load: tested according to ASTM D2783-21.

[0035] Table 1 Performance test results before aging test

[0036] Table 2 Performance test results after aging test

[0037] As can be seen from Examples 1, 1, and 2 in Table 1, the MOF composite material and the anti-wear agent have a good synergistic effect. The methylbenzotriazole in the MOF composite material can react with the metal substrate to form a protective film, thereby reducing the coefficient of friction and wear. Simultaneously, the small particle size of the nano-MOF composite material allows it to embed itself within friction scratches for repair, while the ball-bearing effect formed by the spherical anti-wear agent transforms sliding friction into rolling friction. This synergistic relationship reduces the frictional resistance of the engine lubricating oil of this invention. Furthermore, the eutectic solvent also has good friction-reducing and anti-wear functions. The anti-wear agent of this invention adsorbs the eutectic solvent internally, which is slowly released during the use of the lubricating oil, extending the service life of the lubricating oil and avoiding direct consumption of the friction-reducing and anti-wear agent in the early stages of lubricating oil use. Comparative Example 3 uses conventional molybdenum disulfide, which does not adsorb eutectic solvents and therefore cannot slowly release them during lubricant use. As shown in Tables 1 and 2, after aging tests, the anti-wear performance of the lubricants in Comparative Examples 1 and 3 is significantly lower than that in Examples 1 and 2, indicating a significant decline in lubricant quality. This demonstrates that the slowly released eutectic solvents in the anti-wear agent of this invention can extend the service life of the lubricant. Comparative Example 4 uses ZIF-7 material. ZIF-7 has poor dispersion in lubricant, resulting in poor friction-reducing and anti-wear performance. In this example, methylbenzotriazole was grafted onto ZIF-7. Methylbenzotriazole can improve the dispersibility of ZIF-7 in lubricant and synergistically enhance its friction-reducing and anti-wear effects.

Claims

1. An environmentally friendly, long-life engine lubricant, characterized in that, The composition, by mass percentage, includes: 10-15% synthetic ester, 0.2-3% anti-wear agent, 0.4-0.8% MOF composite material, 8-13% composite additive, 0.1-5% viscosity index improver, 0.1-0.4% pour point depressant, 0.001-0.01% antifoaming agent, and the balance being polyalphaolefin.

2. The environmentally friendly, long-life engine lubricating oil according to claim 1, characterized in that, The preparation method of the MOF composite material is as follows: dissolve methylbenzotriazole in solvent one to obtain an immersion solution, immerse ZIF-7 in the immersion solution, filter, and dry to obtain the final product.

3. The environmentally friendly, long-life engine lubricating oil according to claim 2, characterized in that, The solvent is methanol, the concentration of methylbenzotriazole in the soaking solution is 1-3 mg / mL, and the mass ratio of ZIF-7 to methylbenzotriazole is 1:0.5-1.

5.

4. The environmentally friendly, long-life engine lubricating oil according to claim 2, characterized in that, The soaking temperature is 30–45 °C, and the soaking time is 48–72 h.

5. The environmentally friendly, long-life engine lubricating oil according to claim 1, characterized in that, The method for preparing the anti-wear agent is as follows: menthol and long-chain fatty acids are mixed to obtain a eutectic solvent, the eutectic solvent is dissolved in solvent two to obtain a mixture, spherical porous molybdenum disulfide is placed in the mixture, ultrasonically treated, stirred and solvent two is removed, and then dried to obtain the anti-wear agent.

6. The environmentally friendly, long-life engine lubricating oil according to claim 5, characterized in that, The molar ratio of menthol to long-chain fatty acid is 1:1.9 to 2.1; the long-chain fatty acid is one or more of decanoic acid and lauric acid.

7. The environmentally friendly, long-life engine lubricating oil according to claim 5, characterized in that, The mass ratio of the eutectic solvent to solvent two is 1:8 to 10; the mass ratio of the eutectic solvent to spherical porous molybdenum disulfide is 3 to 4:1; the ultrasonic power is 100 to 120 W and the time is 5 to 8 min; the stirring time is 15 to 18 h; and solvent two is methanol.

8. The environmentally friendly, long-life engine lubricating oil according to claim 1, characterized in that, The synthetic ester is one or more of neopentyl glycol ester, trimethylolpropane ester, and pentaerythritol ester; the pour point depressant is polymethacrylate; the antifoaming agent is polydimethyl silicone oil; and the viscosity index improver is one or more of ethylene propylene copolymer, polyisobutylene, or polymethacrylate.

9. The environmentally friendly, long-life engine lubricating oil according to claim 1, characterized in that, The composite additive comprises 2-6% detergent, 1.5-2% antioxidant, and 1-5% dispersant; the detergent is one or more of sulfonates and sulfide alkylphenol salts; the antioxidant is one or more of phenolic antioxidants and amine antioxidants; and the dispersant is polyisobutylene succinimide.

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