Rust-proof mechanical lubricating oil for automobiles and preparation method of rust-proof mechanical lubricating oil

Abstract

The invention discloses antirust mechanical lubricating oil for automobiles and a preparation method thereof, and relates to the technical field of lubricating oil. Dodecenylsuccinic acid and magnesium hydroxide react to generate carboxylic acid magnesium salt, a compact adsorption film is formed on the metal surface, and metal corrosion is inhibited. Secondly, KH570 is used for modifying nano CeO2, so that double bonds and ester groups are introduced to the surface of CeO2, and due to the existence of the double bonds, CeO2 can be combined with magnesium carboxylate, and the compactness of the film is improved; octyldiphenylamine cooperates with the modified magnesium carboxylate to form a multi-layer anti-oxidation network, so that oxidation is effectively inhibited in high and low temperature environments. Then, due to the existence of ester groups in CeO2, CeO2 can be adsorbed on the surface of wax crystals, so that wax is dispersed in the lubricating oil in a smaller crystal grain form; meanwhile, the magnesium sulfonate clearing agent can prevent small solid particles in the lubricating oil from being gathered into large particles to be deposited, so that the freezing point of the lubricating oil is reduced, and the product is endowed with high stability.

Description

Technical Field

[0001] The present invention relates to the technical field of lubricating oils, and specifically to an anti-rust mechanical lubricating oil for automobiles and a manufacturing method thereof. Background Art

[0002] With the continuous innovation of modern automobile technologies and the continuous improvement of engine performance, automobiles have become an indispensable means of transportation in people's daily lives, and higher requirements are also put forward for the performance of automobile lubricating oils. Lubricating oils play a crucial role in the normal operation of automobiles. It can form an oil film between various moving parts inside the engine, reduce friction and wear, lower energy consumption, protect the engine from corrosion and pollution, and extend the service life of the engine. In harsh environments such as humid, rainy or coastal areas, traditional automobile lubricating oils are prone to being affected by corrosion factors such as moisture and salts on metal parts, which will trigger oxidation and corrosion reactions of metals, and it is difficult to provide long-term effective anti-rust protection, resulting in damage and performance degradation of automobile parts.

[0003] For anti-rust mechanical lubricating oils, in terms of anti-rust, their anti-rust components may decompose or volatilize at high temperatures, losing their anti-rust effects, may cause harm to the environment during use, are not easily uniformly dispersed in the base oil and are prone to conflict with other additives, leading to precipitation or performance degradation. In addition, if the adsorption film at the interface between the lubricating oil and the metal is not tightly combined, it will also reduce the anti-wear and anti-oxidation performance. Therefore, it is particularly important to develop a new type of lubricating oil equipped with an efficient and environmentally friendly anti-rust agent and using a variety of additives to synergistically enhance the effect. Summary of the Invention

[0004] The purpose of the present invention is to provide an anti-rust mechanical lubricating oil for automobiles and a preparation method thereof to solve the problems existing in the prior art.

[0005] To solve the above technical problems, the present invention provides the following technical solution: A preparation method of an anti-rust mechanical lubricating oil for automobiles, including the following preparation steps:

[0006] (1) Mix magnesium hydroxide and deionized water at a mass ratio of 1:10, stir at room temperature and 100 - 300 rpm for 15 - 30 min to prepare a magnesium hydroxide suspension; mix dodecenyl succinic acid and ethanol at a mass ratio of 1:5 and stir at room temperature for 15 - 30 min; at 100 - 300 rpm, add the magnesium hydroxide suspension to the dodecenyl succinic acid solution, react at 60 - 80 °C for 2 - 4 h, filter, wash the solid with deionized water 2 - 4 times, and dry at 60 °C for 3 - 5 h to obtain a magnesium carboxylate salt containing long-chain alkyls;

[0007] (2) Mix the silane coupling agent KH570, absolute ethanol, and deionized water in a three-necked round-bottom flask, stir at 40 °C - 70 °C and 100 - 300 rpm for 30 - 60 min to fully hydrolyze KH570. Add nano-ceria to the solution and continuously stir at a stirring speed of 200 - 400 rpm for 1 - 3 h. Filter, wash the solid with acetone 3 - 5 times, and dry at 70 - 90 °C for 6 - 8 h to introduce double bonds and ester groups on the surface of nano-CeO₂, obtaining modified nano-CeO₂;

[0008] (3) Mix the modified nano-CeO₂, magnesium carboxylate, and deionized water in a mass ratio of 1:5:100 - 3:5:100, stir at 60 - 70 °C and 300 - 500 rpm for 1 - 3 h, filter, wash the solid with acetone 3 - 5 times, and dry at 70 - 90 °C for 6 - 8 h to obtain modified magnesium carboxylate;

[0009] (4) Mix the modified nano-CeO₂ and PAO synthetic oil in a reaction kettle, stir at 100 - 300 rpm for 1 - 2 h to obtain pretreated PAO synthetic oil;

[0010] (5) Take the pretreated PAO synthetic oil obtained in step (4) in a reaction kettle, add the modified magnesium carboxylate obtained in step (3), stir at 20 - 30 °C and 50 - 100 rpm for 20 - 32 min, then add octyldiphenylamine and stir for 20 - 32 min, and finally add magnesium sulfonate detergent and continue to stir for 30 - 40 min to obtain an anti-rust mechanical lubricating oil for automobiles.

[0011] Further, the anti-rust mechanical lubricating oil for automobiles in step (5) includes the following preparation raw materials: 85.5 - 91 parts of pretreated PAO synthetic oil, 3 - 6 parts of modified magnesium carboxylate, 0.5 - 1.5 parts of octyldiphenylamine as an antioxidant, and 1 - 3 parts of magnesium sulfonate detergent as a detergent-dispersant.

[0012] Further, the mass ratio of dodecenyl succinic acid to magnesium hydroxide in step (1) is 5:1 - 7:1.

[0013] Further, the mass ratio of KH570, absolute ethanol, and deionized water in step (2) is 1:40:40 - 1:80:80.

[0014] Further, the particle size of the nano-CeO₂ in step (2) is between 50 nm and 200 nm.

[0015] Further, the mass ratio of the nano-CeO₂ to KH570 in step (2) is 0.5:1 - 1.5:1.

[0016] Further, the mass ratio of the modified nano-CeO2 to the PAO synthetic oil in step (4) is 1:80 - 1:160.

[0017] Further, the preparation method of the PAO synthetic oil in step (4): Dissolve 2.5 - 3 parts of boron trifluoride in 2000 parts of n-heptane solvent, stir at room temperature at 100 - 300 rpm for 30 - 40 min, add 90 - 100 parts of α-olefin to the dissolved catalyst solution, heat the reaction system to 60 - 85 °C, stir at 200 - 400 rpm for 1 - 3 h, cool to room temperature, filter, and retain the solvent without impurities to obtain the PAO synthetic oil.

[0018] Further, the preparation method of octyldiphenylamine in step (5): Mix diphenylamine and molecular sieve catalyst YSBH-3 in a reaction kettle at a mass ratio of 4:1 - 6:1, heat to 50 - 200 °C, stir at 100 - 300 rpm for 0.5 - 5 h, then add diisobutylene which is 1.5 - 2 times the mass of diphenylamine, keep stirring at a constant temperature of 50 - 200 °C for 2 - 20 h, let it stand for 10 - 12 h to separate layers, remove the lower catalyst layer, and retain the upper solvent without impurities to obtain octyldiphenylamine.

[0019] Further, the preparation method of magnesium sulfonate detergent in step (5): Mix the PAO synthetic oil, ethanol, stearic acid, and dodecylbenzenesulfonic acid in a reaction kettle at a mass ratio of 20:4:1:6, heat to 40 - 45 °C, stir at 300 - 500 rpm for 0.5 - 1 h, then add magnesium oxide which is 0.3 - 0.5 times the mass of dodecylbenzenesulfonic acid and continue to stir for 0.5 - 1 h, introduce carbon dioxide until the pH value of the reaction system reaches 9 - 10, then heat the reaction kettle to 150 - 180 °C, carry out vacuum distillation at 4 - 10 kPa for 2 - 4 h, filter impurities to obtain the magnesium sulfonate detergent.

[0020] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0021] The present invention uses PAO synthetic oil, rust inhibitor, anti-wear agent, antioxidant, detergent-dispersant, and pour point depressant as raw materials to prepare a mechanical anti-rust lubricating oil for automobiles, which can achieve good lubrication, rust prevention, anti-wear and other effects, and solve the problems of environmental protection and unstable performance caused by temperature influence of traditional lubricating oils.

[0022] First, dodecenyl succinic acid reacts with magnesium hydroxide to form magnesium carboxylate. As an environmentally friendly rust inhibitor additive, the long-chain alkyl group of the magnesium carboxylate has hydrophobicity, enabling the magnesium carboxylate to form a tight adsorption film on the metal surface and inhibit metal corrosion. The nano-ceria is modified with silane coupling agent KH570. After hydrolysis of KH570, a condensation reaction occurs with the hydroxyl groups on the surface of CeO2, successfully introducing double bonds and ester groups onto the surface of ceria. The presence of double bonds allows nano-CeO2 to combine with magnesium carboxylate, thereby enhancing the density of the film and improving the anti-wear and anti-oxidation properties of the lubricating oil. The presence of ester groups enables nano-CeO2 to adsorb on the surface of wax crystals, preventing PAO molecules from forming a three-dimensional network structure and causing the wax to disperse in the lubricating oil in the form of smaller crystal grains. Octyldiphenylamine synergistically modifies magnesium carboxylate to form a multi-level antioxidant network, effectively inhibiting oxidation in high and low temperature environments and thus extending the service life of the lubricating oil.

[0023] Finally, the addition of magnesium sulfonate detergent can not only neutralize the acidic substances generated during the use of the lubricating oil to protect engine components from corrosion, but also prevent solid small particles dispersed in the lubricating oil from aggregating into larger particles and depositing, thereby reducing the freezing point of the lubricating oil, improving its fluidity at low temperatures and endowing the product with high stability. Specific embodiments

[0024] The following will combine the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0025] In order to more clearly illustrate the method provided by the present invention, the following examples are used for detailed description. The test methods for each index of an anti-rust mechanical lubricating oil for automobiles prepared in the following examples are as follows:

[0026] Rust prevention performance: Immerse the test piece in the lubricating oil of the example and the comparative example for 1 min, conduct a salt spray effect test, place it in a salt spray chamber at 35 °C, corrode for 72 h, and observe whether there are corrosion spots on the surface.

[0027] Anti-oxidation performance: Conduct a thin-film oxidation test to simulate the oxidation of the lubricating oil under the conditions of 160 °C and 620 kPa, and observe the time required for the oxygen pressure to drop by 172 kPa.

[0028] Wear resistance: Use the four-ball friction tester method to judge the anti-wear performance of the lubricating oil according to the size of the wear scar diameter.

[0029] Dispersion performance: Drop a certain amount of lubricating oil sample on the filter paper and let the oil drop naturally spread to form a spot, and observe the distribution of the spot.

[0030] Example 1

[0031] (1) Mix magnesium hydroxide and deionized water at a mass ratio of 1:10, stir at room temperature and 100 rpm for 15 min to prepare a magnesium hydroxide suspension; mix dodecenyl succinic acid and ethanol at a mass ratio of 1:5, stir at room temperature and 100 rpm for 15 min to make a dodecenyl succinic acid solution; at 100 rpm, add a magnesium hydroxide suspension with a mass 1 / 7 times that of dodecenyl succinic acid to the dodecenyl succinic acid solution, react at 60 °C for 2 h, filter, wash the solid with deionized water twice, and dry at 60 °C for 3 h to obtain a magnesium carboxylate salt containing long-chain alkyl groups;

[0032] (2) Mix silane coupling agent KH570, absolute ethanol and deionized water in a three-necked round-bottom flask at a mass ratio of 1:40:40, stir at 40 °C and 100 rpm for 30 min to fully hydrolyze KH570, add nano-ceria with a mass 1 / 2 times that of KH570 to the solution, continuously stir at a stirring speed of 200 rpm for 1 h, filter, wash the solid with acetone three times, and dry at 70 °C for 6 h to introduce double bonds and ester groups on the surface of nano-CeO2 and obtain modified nano-CeO2;

[0033] (3) Mix modified nano-CeO2, magnesium carboxylate salt and deionized water at a mass ratio of 1:5:100, stir at 60 °C and 300 rpm for 1 h, filter, wash the solid with acetone three times, and dry at 70 °C for 6 h to obtain a modified magnesium carboxylate salt;

[0034] (4) Dissolve 2.5 parts of boron trifluoride in 2000 parts of n-heptane solvent, stir at room temperature and 100 rpm for 30 min, add 90 parts of α-olefin to the dissolved catalyst solution, heat the reaction system to 60 °C, stir at 200 rpm for 1 h, cool to room temperature, filter, and retain the solvent without impurities to obtain PAO synthetic oil;

[0035] (5) Mix modified nano-CeO2 and the PAO synthetic oil obtained in step (4) in a reaction kettle at a mass ratio of 1:80, stir at 100 rpm for 1 h to obtain a pretreated PAO synthetic oil;

[0036] (6) Mix diphenylamine and molecular sieve catalyst YSBH-3 in a reaction kettle at a mass ratio of 4:1, heat to 50 °C, stir at 100 rpm for 0.5 h, then add diisobutylene with a mass 1.5 times that of diphenylamine, keep stirring at 50 °C for 2 h, let it stand for 10 h to separate layers, remove the lower catalyst layer, and retain the upper solvent without impurities to obtain octyldiphenylamine;

[0037] (7) Mix PAO synthetic oil, ethanol, stearic acid, and dodecylbenzenesulfonic acid in a reaction kettle at a mass ratio of 20:4:1:6. Heat up to 40 °C, stir at 300 rpm for 0.5 h, then add magnesium oxide which is 0.3 times the mass of dodecylbenzenesulfonic acid and continue stirring for 0.5 h. Introduce carbon dioxide until the pH value of the reaction system reaches 9, then heat up the reaction kettle to 150 °C and carry out vacuum distillation at 4 kPa for 2 h. Filter impurities to obtain magnesium sulfonate detergent;

[0038] (8) Take 85.5 parts of the pretreated PAO synthetic oil obtained in step (5) in a reaction kettle, add 3 parts of the modified magnesium carboxylate obtained in step (3), stir at 20 °C and 50 rpm for 20 min, then add 0.5 part of the octyldiphenylamine obtained in step (6) and stir for 20 min. Finally, add 1 part of the magnesium sulfonate detergent obtained in step (7) and continue stirring for 30 min to obtain an anti-rust mechanical lubricating oil for automobiles.

[0039] Example 2

[0040] (1) Mix magnesium hydroxide and deionized water at a mass ratio of 1:10, stir at room temperature and 200 rpm for 25 min to prepare a magnesium hydroxide suspension; mix dodecenyl succinic acid and ethanol at a mass ratio of 1:5, stir at room temperature and 200 rpm for 25 min to make a dodecenyl succinic acid solution; at 200 rpm, add the magnesium hydroxide suspension which is 1 / 6 times the mass of dodecenyl succinic acid to the dodecenyl succinic acid solution, react at 70 °C for 3 h, filter, wash the solid with deionized water 3 times, and dry at 60 °C for 4 h to obtain a magnesium carboxylate salt containing long-chain alkyl groups;

[0041] (2) Mix silane coupling agent KH570, absolute ethanol, and deionized water in a three-necked round-bottom flask at a mass ratio of 1:60:60, stir at 55 °C and 200 rpm for 45 min to fully hydrolyze KH570. Add nano-ceria with the same mass as KH570 to the solution, continuously stir at a stirring speed of 300 rpm for 2 h, filter, wash the solid with acetone 4 times, and dry at 80 °C for 7 h to introduce double bonds and ester groups on the surface of nano-CeO2 and obtain modified nano-CeO2;

[0042] (3) Mix modified nano-CeO2, magnesium carboxylate salt, and deionized water at a mass ratio of 2:5:100, stir at 65 °C and 400 rpm for 2 h, filter, wash the solid with acetone 4 times, and dry at 80 °C for 7 h to obtain a modified magnesium carboxylate salt;

[0043] (4) Dissolve 2.7 parts of boron trifluoride in 2000 parts of n - heptane solvent at room temperature, stir at 200 rpm for 35 min, add 95 parts of α - olefin to the dissolved catalyst solution, heat the reaction system to 70 °C, stir at 300 rpm for 2 h, cool to room temperature, filter, and retain the solvent without impurities to obtain PAO synthetic oil;

[0044] (5) Mix the modified nano - CeO₂ and the PAO synthetic oil obtained in step (4) in a mass ratio of 1:120 in a reaction kettle, stir at 200 rpm for 1.5 h to obtain pretreated PAO synthetic oil;

[0045] (6) Mix diphenylamine and molecular sieve catalyst YSBH - 3 in a mass ratio of 5:1 in a reaction kettle, heat up to 125 °C, stir at 200 rpm for 3.5 h, then add diisobutylene which is 1.7 times the mass of diphenylamine, keep stirring at 125 °C for 11 h, let it stand for 11 h to separate layers, and remove the lower catalyst layer, retain the upper solvent without impurities to obtain octyldiphenylamine;

[0046] (7) Mix PAO synthetic oil, ethanol, stearic acid and dodecylbenzenesulfonic acid in a mass ratio of 20:4:1:6 in a reaction kettle, heat up to 42 °C, stir at 400 rpm for 1 h, then add magnesium oxide which is 0.4 times the mass of dodecylbenzenesulfonic acid and continue stirring for 1 h, introduce carbon dioxide until the pH value of the reaction system reaches 9, then heat the reaction kettle to 165 °C, carry out vacuum distillation at 7 kPa for 3 h, filter impurities to obtain magnesium sulfonate detergent;

[0047] (8) Take 88 parts of the pretreated PAO synthetic oil obtained in step (5) in a reaction kettle, add 4.5 parts of the modified magnesium carboxylate salt obtained in step (3), stir at 20 °C and 50 rpm for 20 min, then add 1 part of the octyldiphenylamine obtained in step (6) and stir for 20 min, finally add 2 parts of the magnesium sulfonate detergent obtained in step (7), and continue stirring for 30 min to obtain automotive anti - rust mechanical lubricating oil.

[0048] Example 3

[0049] (1) Mix magnesium hydroxide and deionized water in a mass ratio of 1:10, stir at room temperature and 300 rpm for 30 min to prepare a magnesium hydroxide suspension; mix dodecenyl succinic acid and ethanol in a mass ratio of 1:5, stir at room temperature and 300 rpm for 30 min to prepare a dodecenyl succinic acid solution; at 300 rpm, add the magnesium hydroxide suspension which is 1 / 5 times the mass of dodecenyl succinic acid to the dodecenyl succinic acid solution, react at 80 °C for 4 h, filter, wash the solid with deionized water 4 times, and dry at 60 °C for 5 h to obtain a magnesium carboxylate salt containing long - chain alkyl;

[0050] (2) Mix silane coupling agent KH570, absolute ethanol, and deionized water in a mass ratio of 1:80:80 in a three-necked round-bottom flask. Stir at 70 °C and 300 rpm for 60 min to fully hydrolyze KH570. Add nano-ceria with 1.5 times the mass of KH570 to the solution, and continuously stir at a stirring speed of 400 rpm for 3 h. Filter, wash the solid with acetone 5 times, and dry at 90 °C for 8 h to introduce double bonds and ester groups on the surface of nano-CeO2, obtaining modified nano-CeO2;

[0051] (3) Mix modified nano-CeO2, magnesium carboxylate salt, and deionized water in a mass ratio of 3:5:100, stir at 70 °C and 500 rpm for 3 h, filter, wash the solid with acetone 5 times, and dry at 90 °C for 8 h to obtain modified magnesium carboxylate salt;

[0052] (4) Dissolve 3 parts of boron trifluoride in 2000 parts of n-heptane solvent, stir at room temperature and 300 rpm for 40 min. Add 100 parts of α-olefin to the dissolved catalyst solution, heat the reaction system to 85 °C, stir at 400 rpm for 3 h, cool to room temperature, filter, and retain the solvent without impurities to obtain PAO synthetic oil;

[0053] (5) Mix modified nano-CeO2 and the PAO synthetic oil obtained in step (4) in a mass ratio of 1:160 in a reaction kettle, stir at 300 rpm for 2 h to obtain pretreated PAO synthetic oil;

[0054] (6) Mix diphenylamine and molecular sieve catalyst YSBH-3 in a mass ratio of 6:1 in a reaction kettle, heat to 200 °C, stir at 300 rpm for 5 h, then add diisobutene with 2 times the mass of diphenylamine, and continuously stir at 200 °C for 20 h. Let it stand for 12 h to separate layers, and remove the lower catalyst layer to retain the upper solvent without impurities to obtain octyldiphenylamine;

[0055] (7) Mix PAO synthetic oil, ethanol, stearic acid, and dodecylbenzenesulfonic acid in a mass ratio of 20:4:1:6 in a reaction kettle, heat to 45 °C, stir at 500 rpm for 1 h, then add magnesium oxide with 0.5 times the mass of dodecylbenzenesulfonic acid and continue to stir for 1 h. Introduce carbon dioxide until the pH value of the reaction system reaches 10, then heat the reaction kettle to 180 °C and perform vacuum distillation at 10 kPa for 4 h, filter impurities to obtain magnesium sulfonate detergent;

[0056] (8) Take 91 parts of the pretreated PAO synthetic oil obtained in step (5) into a reaction kettle, add 6 parts of the modified magnesium carboxylate obtained in step (3), stir at 20 °C and 50 rpm for 20 min, then add 1.5 parts of the octyldiphenylamine obtained in step (6) and stir for 20 min. Finally, add 3 parts of the magnesium sulfonate detergent obtained in step (7) and continue to stir for 30 min to prepare an anti-rust mechanical lubricating oil for automobiles.

[0057] Comparative Example 1

[0058] The difference between Comparative Example 1 and Example 2 lies in step (1). Modify step (1) as follows: Mix magnesium hydroxide and deionized water at a mass ratio of 1:10, stir at room temperature and 200 rpm for 25 min to prepare a magnesium hydroxide suspension; mix dodecenyl succinic acid and ethanol at a mass ratio of 1:5, stir at room temperature and 200 rpm for 25 min to make a dodecenyl succinic acid solution; at 200 rpm, add the magnesium hydroxide suspension with a mass 1 / 7 times that of dodecenyl succinic acid to the dodecenyl succinic acid solution, react at 70 °C for 3 h, filter, wash the solid with deionized water 3 times, and dry at 60 °C for 4 h to obtain a magnesium carboxylate salt containing long-chain alkyl groups; the remaining steps are the same as those in Example 2.

[0059] Comparative Example 2

[0060] The difference between Comparative Example 2 and Example 2 lies in step (2). Modify step (2) as follows: Mix silane coupling agent KH570, absolute ethanol and deionized water at a mass ratio of 1:60:60 in a three-necked round-bottom flask, stir at 55 °C and 200 rpm for 45 min to fully hydrolyze KH570, add nano-ceria with a mass 0.5 times that of KH570 to the solution, continuously stir at a stirring speed of 300 rpm for 2 h, filter, wash the solid with acetone 4 times, and dry at 80 °C for 7 h to introduce double bonds and ester groups on the surface of nano-CeO2 to obtain modified nano-CeO2; the remaining steps are the same as those in Example 2.

[0061] Comparative Example 3

[0062] The difference between Comparative Example 3 and Example 2 lies in step (3). Modify step (3) as follows: Mix modified nano-CeO2, magnesium carboxylate salt and deionized water at a mass ratio of 1:5:100, stir at 65 °C and 400 rpm for 2 h, filter, wash the solid with acetone 4 times, and dry at 80 °C for 7 h to obtain a modified magnesium carboxylate salt; the remaining steps are the same as those in Example 2.

[0063] Comparative Example 4

[0064] The difference between Comparative Example 4 and Example 2 lies in step (4). Step (4) is changed to: Dissolve 2.5 parts of boron trifluoride in 2,000 parts of n-heptane solvent at room temperature, stir at 200 rpm for 35 min, add 95 parts of α-olefin to the dissolved catalyst solution, heat the reaction system to 70 °C, stir at 300 rpm for 2 h, cool to room temperature, filter, retain the solvent without impurities, and obtain PAO synthetic oil; the remaining steps are the same as those in Example 2.

[0065] Comparative Example 5

[0066] The difference between Comparative Example 5 and Example 2 lies in step (5). Step (5) is changed to: Mix modified nano-CeO2 and the PAO synthetic oil obtained in step (4) in a reaction kettle at a mass ratio of 1:160, stir at 200 rpm for 1.5 h to obtain pretreated PAO synthetic oil; the remaining steps are the same as those in Example 2.

[0067] Comparative Example 6

[0068] The difference between Comparative Example 6 and Example 2 lies in step (6). Step (6) is changed to: Mix diphenylamine and molecular sieve catalyst YSBH-3 in a reaction kettle at a mass ratio of 4:1, heat to 125 °C, stir at 200 rpm for 3.5 h, then add diisobutylene which is 1.7 times the mass of diphenylamine, keep stirring at 125 °C for 11 h, let it stand for 11 h to separate layers, remove the lower catalyst layer, and retain the upper solvent without impurities to obtain octyldiphenylamine; the remaining steps are the same as those in Example 2.

[0069] Comparative Example 7

[0070] The difference between Comparative Example 7 and Example 2 lies in step (7). Step (7) is changed to: Mix PAO synthetic oil, ethanol, stearic acid and dodecylbenzenesulfonic acid in a reaction kettle at a mass ratio of 20:4:1:6, heat to 42 °C, stir at 400 rpm for 1 h, then add magnesium oxide which is 0.3 times the mass of dodecylbenzenesulfonic acid and continue stirring for 1 h, introduce carbon dioxide until the pH value of the reaction system reaches 9, then heat the reaction kettle to 165 °C, carry out vacuum distillation at 7 kPa for 3 h, filter impurities, and obtain magnesium sulfonate detergent; the remaining steps are the same as those in Example 2.

[0071] Comparative Example 8

[0072] The difference between Comparative Example 8 and Example 2 lies in step (8). Step (8) is modified as follows: Take 85.5 parts of the pretreated PAO synthetic oil obtained in step (5) into a reaction kettle, add 3 parts of the modified magnesium carboxylate obtained in step (3), stir at 20 °C and 50 rpm for 20 min, then add 0.5 part of the octyldiphenylamine obtained in step (6) and stir for 20 min, and finally add 1 part of the magnesium sulfonate detergent obtained in step (7), and continue to stir for 30 min to obtain an anti-rust mechanical lubricating oil for automobiles.

[0073] Effect Example

[0074] Table 1 below gives the performance analysis results of the anti-rust mechanical lubricating oils of Examples 1 to 3 and Comparative Examples 1 to 8 of the present invention.

[0075] Table 1

[0076]

[0077]

[0078] From the comparison of the experimental data of the wear scar diameter of the examples and comparative examples, it can be found that the magnesium carboxylate salt formed by the reaction of dodecenyl succinic acid and magnesium hydroxide in this product forms a tight adsorption film with the metal surface, which can effectively inhibit metal corrosion; from the comparison of the experimental data of the corrosion situation and oxidation time, it can be found that after using KH570-modified nano-CeO2 in this product, the introduction of double bonds on the surface of nano-CeO2 enables nano-CeO2 to be loaded on the surface of the magnesium carboxylate salt, further improving the anti-wear and anti-oxidation performance of the lubricating oil. At the same time, the presence of octyldiphenylamine synergistically modifies the magnesium carboxylate salt to form a multi-level antioxidant network, effectively inhibiting oxidation in high and low temperature environments; from the comparison of the experimental data of the dispersion situation, it can be found that after KH570-modified nano-CeO2, the ester groups introduced on the surface of nano-CeO2 enable nano-CeO2 to adsorb on the surface of wax crystals, preventing PAO molecules from forming a three-dimensional network structure, and making the wax disperse in the lubricating oil in the form of smaller crystal grains; on the other hand, the magnesium sulfonate detergent can prevent the solid small particles dispersed in the lubricating oil from aggregating into larger particles and depositing, thereby reducing the freezing point of the lubricating oil, improving the fluidity of the lubricating oil at low temperature and endowing the product with high stability.

[0079] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above-described exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced within the present invention. Any reference signs in the claims should not be construed as limiting the claims involved.

Claims

1. A preparation method of an anti-rust mechanical lubricating oil for automobiles, characterized in that, It includes the following preparation steps: (1) Mix magnesium hydroxide and deionized water at a mass ratio of 1:10, stir at room temperature and 100 - 300 rpm for 15 - 30 min to prepare a magnesium hydroxide suspension; mix dodecenyl succinic acid and ethanol at a mass ratio of 1:5, stir at room temperature and 100 - 300 rpm for 15 - 30 min to make a dodecenyl succinic acid solution; at 100 - 300 rpm, add the magnesium hydroxide suspension to the dodecenyl succinic acid solution, react at 60 - 80 °C for 2 - 4 h, filter, wash the solid with deionized water 2 - 4 times, and dry at 60 °C for 3 - 5 h to obtain a magnesium carboxylate salt containing long-chain alkyl groups; (2) Mix the silane coupling agent KH570, absolute ethanol and deionized water in a three-necked round-bottom flask, stir at 40 °C - 70 °C and 100 - 300 rpm for 30 - 60 min to fully hydrolyze KH570, add nano-ceria to the solution, continuously stir at a stirring speed of 200 - 400 rpm for 1 - 3 h, filter, wash the solid with acetone 3 - 5 times, and dry at 70 - 90 °C for 6 - 8 h to introduce double bonds and ester groups on the surface of nano-CeO₂ and obtain modified nano-CeO₂; (3) Mix the modified nano-CeO₂, magnesium carboxylate salt and deionized water at a mass ratio of 1:5:100 - 3:5:100, stir at 60 - 70 °C and 300 - 500 rpm for 1 - 3 h, filter, wash the solid with acetone 3 - 5 times, and dry at 70 - 90 °C for 6 - 8 h to obtain a modified magnesium carboxylate salt; (4) Mix the modified nano-CeO₂ and PAO synthetic oil in a reaction kettle, stir at 100 - 300 rpm for 1 - 2 h to obtain a pretreated PAO synthetic oil; (5) Take the pretreated PAO synthetic oil obtained in step (4) in a reaction kettle, add the modified magnesium carboxylate salt obtained in step (3), stir at 20 - 30 °C and 50 - 100 rpm for 20 - 32 min, then add octyldiphenylamine and stir for 20 - 32 min, and finally add magnesium sulfonate detergent and continue to stir for 30 - 40 min to obtain an anti-rust mechanical lubricating oil for automobiles.

2. The anti-rust mechanical lubricating oil for automobiles according to claim 1, characterized in that, The anti-rust mechanical lubricating oil for automobiles in step (5) includes the following preparation raw materials: 85.5 - 91 parts of pretreated PAO synthetic oil, 3 - 6 parts of modified magnesium carboxylate salt, 0.5 - 1.5 parts of octyldiphenylamine as an antioxidant, and 1 - 3 parts of magnesium sulfonate detergent as a detergent-dispersant.

3. The preparation method of an anti-rust mechanical lubricating oil for automobiles according to claim 1, characterized in that, In step (1), the mass ratio of dodecenyl succinic acid to magnesium hydroxide is 5:1 - 7:

1.

4. The preparation method of an anti-rust mechanical lubricating oil for automobiles according to claim 1, characterized in that, In step (2), the mass ratio of KH570, absolute ethanol and deionized water is 1:40:40 - 1:80:

80.

5. The preparation method of an anti-rust mechanical lubricating oil for automobiles according to claim 1, characterized in that, In step (2), the particle size of the nano-CeO₂ is between 50 nm and 200 nm.

6. The preparation method of an anti-rust mechanical lubricating oil for automobiles according to claim 1, characterized in that, In step (2), the mass ratio of nano-CeO₂ to KH570 is 0.5:1 - 1.5:

1.

7. The preparation method of an anti-rust mechanical lubricating oil for automobiles according to claim 1, characterized in that, In step (4), the mass ratio of the modified nano-CeO₂ to the PAO synthetic oil is 1:80 - 1:

160.

8. The preparation method of an anti-rust mechanical lubricating oil for automobiles according to claim 1, characterized in that, Preparation method of the PAO synthetic oil described in step (4): Dissolve 2.5 - 3 parts of boron trifluoride in 2000 parts of n - heptane solvent. At room temperature, stir for 30 - 40 min at 100 - 300 rpm. Add 90 - 100 parts of α - olefin to the dissolved catalyst solution. Heat the reaction system to 60 - 85 °C and stir for 1 - 3 h at 200 - 400 rpm. Cool to room temperature, filter, and retain the solvent without impurities to obtain the PAO synthetic oil.

9. The preparation method of an anti-rust mechanical lubricating oil for automobiles according to claim 2, characterized in that, Preparation method of the octyldiphenylamine: Mix diphenylamine and molecular sieve catalyst YSBH - 3 in a reaction kettle at a mass ratio of 4:1 - 6:

1. Heat to 50 - 200 °C and stir at 100 - 300 rpm for 0.5 - 5 h. Then add diisobutylene with a mass 1.5 - 2 times that of diphenylamine and stir at a constant temperature of 50 - 200 °C for 2 - 20 h. Let it stand for 10 - 12 h to separate layers, and remove the lower catalyst layer. Retain the upper solvent without impurities to obtain octyldiphenylamine.

10. The preparation method of an anti-rust mechanical lubricating oil for automobiles according to claim 2, characterized in that, Preparation method of the magnesium sulfonate detergent: Mix the PAO synthetic oil, ethanol, stearic acid, and dodecylbenzenesulfonic acid in a reaction kettle at a mass ratio of 20:4:1:

6. Heat to 40 - 45 °C and stir at 300 - 500 rpm for 0.5 - 1 h. Then add magnesium oxide with a mass 0.3 - 0.5 times that of dodecylbenzenesulfonic acid and continue to stir for 0.5 - 1 h. Introduce carbon dioxide until the pH value of the reaction system reaches 9 - 10, then heat the reaction kettle to 150 - 180 °C and carry out vacuum distillation at 4 - 10 kPa for 2 - 4 h. Filter out impurities to obtain the magnesium sulfonate detergent.

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