Lubricating oil composition and preparation method thereof

Abstract

The invention belongs to the technical field of lubricating oil, and particularly relates to a lubricating oil composition and a preparation method thereof. The lubricating oil composition is prepared from the following raw materials in percentage by weight: 4 to 9 weight percent of extreme pressure anti-wear agent, 2 to 5 weight percent of antioxidant, 0.8 to 1.5 weight percent of anticoagulant, 0.2 to 0.5 weight percent of metal deactivator and the balance of base oil, the anti-wear reagent at extreme pressure is prepared by the following preparation processes: adding black scale alkene and nano cerium hydroxide into acetone, carrying out electrostatic self-assembly under an ultrasonic condition, centrifuging and drying to obtain the anti-wear reagent at extreme pressure. The lubricating oil composition disclosed by the invention has good wear resistance and excellent oxidation resistance.

Description

Technical Field

[0001] This invention belongs to the field of lubricating oil technology, specifically relating to a lubricating oil composition and its preparation method. Background Technology

[0002] In modern society, large-scale mechanized production is a crucial mode of production driving economic development. Friction and wear inevitably occur between moving parts in mechanical systems, leading not only to significant energy waste but also severe damage to these components. For example, shape memory alloys may fail to meet design requirements due to uneven friction during processing. Therefore, lubricants are indispensable functional materials for maintaining smooth equipment operation, reducing friction in mechanical parts, lowering labor loads, and mitigating equipment wear. Lubricating oil is a commonly used lubricant in production, typically composed of base oil and additives. Base oil alone is prone to oxidation and aging under complex working conditions such as high temperature and high pressure, leading to deterioration and even loss of lubrication ability. Adding appropriate additives can improve its physicochemical properties, which is an effective way to enhance the overall performance of lubricating oil.

[0003] Lubricating oil additives mainly include corrosion inhibitors, antioxidants, extreme pressure anti-wear agents, emulsifiers, and dispersants. These additives work synergistically through mechanisms such as interface modification and friction film formation, significantly improving the oxidation stability, load-bearing capacity, and low-temperature flow characteristics of lubricating oils. As mechanical equipment rapidly develops towards high speed, heavy load, and precision, the working conditions of friction interfaces are becoming increasingly complex and extreme. Lubricating oils also face harsh working environments such as high temperatures and extreme pressures in practical applications. Traditional additives are gradually failing to meet the demands of industrial activities, exhibiting problems such as aging and performance degradation under harsh working conditions. To overcome these limitations, developing novel multifunctional materials, such as two-dimensional materials, nanomaterials, and biodegradable materials, as lubricating oil additives is of great significance for enhancing the overall performance of lubricating oils and achieving energy conservation and emission reduction. Summary of the Invention

[0004] The primary objective of this invention is to provide a lubricating oil composition that exhibits good wear resistance and excellent oxidation resistance.

[0005] A second objective of the present invention is to provide a method for preparing the above-mentioned lubricating oil composition.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A lubricating oil composition comprising the following raw materials in weight percentages: 4-9 wt% extreme pressure anti-wear agent, 2-5 wt% antioxidant, 0.8-1.5 wt% anti-gelling agent, 0.2-0.5 wt% metal deactivator, with the balance being base oil; The extreme pressure anti-wear agent is prepared by the following process: Black lepidocrolide and nano-cerium hydroxide were added to acetone and subjected to electrostatic self-assembly under ultrasonic conditions. After centrifugation and drying, the extreme pressure anti-wear agent was obtained.

[0007] Furthermore, the mass ratio of the black lepidocrolide to nano-cerium hydroxide is 1:1-10.

[0008] Furthermore, the power of the ultrasound is 30-50W, and the duration is 20-40 minutes.

[0009] Furthermore, the antioxidant is prepared by the following process: (1) Add copper salt, iron salt and pyromellitic acid to N,N-dimethylformamide and stir to obtain Fe-Cu bimetallic organic framework precursor solution; (2) Sodium dioctyl succinate sulfonate was added to the Fe-Cu bimetallic organic framework precursor solution and heated to react. After the reaction was completed, the solid substance was filtered out, washed and dried to obtain the antioxidant.

[0010] Further, the molar ratio of copper salt, iron salt and pyromellitic acid in step (1) is 1:(2-4):(1-2).

[0011] Furthermore, the copper salt is any one of copper nitrate, copper sulfate, or copper chloride; the iron salt is any one of ferric nitrate, ferric sulfate, or ferric chloride.

[0012] Further, in step (2), the ratio of sodium dioctyl succinate sulfonate to Fe-Cu bimetallic organic framework precursor solution is 0.1 mol: 3-5 L.

[0013] Furthermore, the heating reaction in step (2) is carried out at a temperature of 120-160°C for 20-25 hours.

[0014] Furthermore, the anticoagulant is a polyalphaolefin; the metal deactivator is methylbenzotriazole; and the base oil is a polyalkylene glycol.

[0015] A method for preparing the above-mentioned lubricating oil composition includes the following steps: Weigh each raw material according to the stated weight percentage, mix them evenly, and obtain the lubricating oil composition.

[0016] The beneficial technical effects of this invention are as follows: 1. This invention adds cerium hydroxide-modified black phosphorus as an extreme pressure anti-wear agent to lubricating oil, exhibiting excellent friction-reducing and lubrication properties and high thermal stability. Black phosphorus has a unique two-dimensional layered structure, which can slip through interlayer shear forces during friction, thereby reducing friction. By modifying black phosphorus with cerium hydroxide, nanoparticles can form a high-load-bearing protective film on the friction surface, synergistically reducing friction and wear with black phosphorus. Furthermore, cerium hydroxide has high thermal stability, which can prevent oxidation when coated on the surface of black phosphorus, while black phosphorus has high thermal conductivity, playing a role in rapid heat dissipation. The synergistic effect of these two additives ensures that the lubricating oil maintains good lubrication performance under high-temperature conditions.

[0017] 2. This invention prepares a composite material of sodium dioctyl succinate sulfonate (AOT) and a Fe-Cu bimetallic organic framework as an antioxidant, which has the functions of rust prevention, oxidation resistance, and improved wear resistance and dispersibility. The bimetallic organic framework has high porosity and high specific surface area, exposing many bimetallic active sites, which can adsorb and scavenge various reactive oxygen free radicals, thus playing an antioxidant role in lubricating oil. Moreover, the porous structure can achieve loading and slow release of AOT. As a surfactant, AOT can ensure the uniform dispersion of the organic framework in lubricating oil, and AOT can form an adsorption film on the metal surface, synergistically inhibiting metal corrosion with the copper ions released by the organic framework. In addition, the two synergistically form a composite film layer on the surface of the friction pair, which also has the functions of reducing the coefficient of friction and enhancing extreme pressure performance. Attached Figure Description

[0018] Figure 1 This is a scanning electron microscope image of the extreme pressure anti-wear agent prepared in Example 1 of the present invention. Detailed Implementation

[0019] The following is a further detailed description of the present invention in conjunction with specific preferred embodiments, and it should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention. Specific conditions not specified in the embodiments are performed according to conventional conditions or conditions recommended by the manufacturer. Unless otherwise specified, all reagents or instruments used are conventional products obtained through commercial channels.

[0020] The polyα-olefin of this invention has a kinematic viscosity of 30-80 mmHg at 40°C. 2 / s, pour point not higher than -15℃; the kinematic viscosity of polyalkylene glycol at 40℃ is 30-80 mm. 2 / s, pour point not higher than -15℃.

[0021] (I) Implementation Examples Example 1 Example 1 provides a lubricating oil composition comprising the following raw materials by weight percentage: 6 wt% extreme pressure anti-wear agent, 3 wt% antioxidant, 1 wt% polyalphaolefin, 4 wt% methylbenzotriazole, and the balance being polyalkylene glycol.

[0022] The extreme pressure anti-wear agent is prepared by the following process: According to the ratio of black styrene, nano-cerium hydroxide, and acetone 1g:6g:22mL, black styrene and nano-cerium hydroxide were added to acetone, and electrostatic assembly was performed by sonication at 40W for 30min. After centrifugation and drying, the extreme pressure anti-wear agent was obtained. Figure 1 This is a scanning electron microscope image of the extreme pressure anti-wear agent.

[0023] The antioxidant is prepared by the following process: (1) Copper nitrate, ferric nitrate, trimesic acid and N,N-dimethylformamide were added to N,N-dimethylformamide and stirred according to the ratio of copper nitrate, ferric nitrate, trimesic acid and N,N-dimethylformamide 1mol: 3mol: 1mol: 20L to obtain Fe-Cu bimetallic organic framework precursor solution; (2) Sodium dioctyl succinate sulfonate was added to the Fe-Cu bimetallic organic framework precursor solution at a ratio of 0.1 mol: 4 L, and the reaction was carried out at 140 °C for 24 h. After the reaction was completed, the solid substance was filtered out, washed and dried to obtain the antioxidant.

[0024] This embodiment also provides a method for preparing the above-mentioned lubricating oil composition, the specific steps of which are as follows: Weigh each raw material according to the above weight percentages, mix them evenly to obtain a lubricating oil composition.

[0025] Example 2 Example 2 provides a lubricating oil composition comprising the following raw materials in weight percentage: 4 wt% extreme pressure anti-wear agent, 2 wt% antioxidant, 0.8 wt% polyalphaolefin, 0.2 wt% methylbenzotriazole, and the balance being polyalkylene glycol.

[0026] The extreme pressure anti-wear agent is prepared by the following process: According to the ratio of black styrene, nano-cerium hydroxide and acetone 1g:1g:20mL, black styrene and nano-cerium hydroxide were added to acetone, and electrostatic assembly was performed by sonication at 30W power for 20min. After centrifugation and drying, extreme pressure anti-wear agent was obtained.

[0027] The antioxidant is prepared by the following process: (1) Copper nitrate, ferric nitrate, trimesic acid and N,N-dimethylformamide were added to N,N-dimethylformamide and stirred according to the ratio of copper nitrate, ferric nitrate, trimesic acid and N,N-dimethylformamide 1mol: 2mol: 1mol: 15L to obtain Fe-Cu bimetallic organic framework precursor solution; (2) Sodium dioctyl succinate sulfonate was added to the Fe-Cu bimetallic organic framework precursor solution at a ratio of 0.1 mol: 3 L, and the reaction was carried out at 120 °C for 20 h. After the reaction was completed, the solid substance was filtered out, washed and dried to obtain the antioxidant.

[0028] This embodiment also provides a method for preparing the above-mentioned lubricating oil composition, the specific steps of which are as follows: Weigh each raw material according to the above weight percentages, mix them evenly to obtain a lubricating oil composition.

[0029] Example 3 Example 3 provides a lubricating oil composition comprising the following raw materials in weight percentage: 9 wt% extreme pressure anti-wear agent, 5 wt% antioxidant, 1.5 wt% polyalphaolefin, 0.5 wt% methylbenzotriazole, and the balance being polyalkylene glycol.

[0030] The extreme pressure anti-wear agent is prepared by the following process: According to the ratio of black styrene, nano-cerium hydroxide and acetone 1g:10g:25mL, black styrene and nano-cerium hydroxide were added to acetone and electrostatically assembled by sonication at 50W power for 40min. After centrifugation and drying, extreme pressure anti-wear agent was obtained.

[0031] The antioxidant is prepared by the following process: (1) Copper nitrate, ferric nitrate, trimesic acid and N,N-dimethylformamide were added to N,N-dimethylformamide and stirred according to the ratio of copper nitrate, ferric nitrate, trimesic acid and N,N-dimethylformamide 1mol: 4mol: 2mol: 25L to obtain Fe-Cu bimetallic organic framework precursor solution. (2) Sodium dioctyl succinate sulfonate was added to the Fe-Cu bimetallic organic framework precursor solution at a ratio of 0.1 mol: 5 L, and the reaction was carried out at 160 °C for 25 h. After the reaction was completed, the solid substance was filtered out, washed and dried to obtain the antioxidant.

[0032] This embodiment also provides a method for preparing the above-mentioned lubricating oil composition, the specific steps of which are as follows: Weigh each raw material according to the above weight percentages, mix them evenly to obtain a lubricating oil composition.

[0033] (ii) Comparative Example Comparative Example 1 Comparative Example 1 is basically the same as Example 1, except that the extreme pressure anti-wear agent in Example 1 is replaced with black styrene.

[0034] Comparative Example 2 Comparative Example 2 is basically the same as Example 1, except that the extreme pressure anti-wear agent in Example 1 is replaced with a physical mixture of black styrene and nano-cerium hydroxide.

[0035] Comparative Example 3 Comparative Example 3 is basically the same as Example 1, except that sodium dioctyl succinate sulfonate in step (2) of Example 1 is omitted, i.e. Fe-Cu bimetallic organic framework is used as antioxidant.

[0036] Comparative Example 4 Comparative Example 4 is basically the same as Example 1, except that sodium dioctyl succinate sulfonate in step (2) of Example 1 is omitted to obtain Fe-Cu bimetallic organic framework, and then Fe-Cu bimetallic organic framework and sodium dioctyl succinate sulfonate are physically mixed as antioxidant.

[0037] (III) Test Examples The lubricating oil compositions prepared in Examples 1-3 and Comparative Examples 1-4 were subjected to the following performance tests.

[0038] Wear resistance test: According to GB / T3142-2019 "Determination of load-carrying capacity of lubricants - Four-ball method", the maximum non-seize load (P) of the lubricating oil compositions of Examples 1-3 and Comparative Examples 1-4 was tested. B The results for the wear scar diameter ( / N) are shown in Table 1.

[0039] Oxidation stability test: The oxidation stability of the lubricating oil compositions of Examples 1-3 and Comparative Examples 1-4 was tested according to the method of NB / SH / T 0193-2022 "Determination of Oxidation Stability of Lubricating Oils - Rotating Bomb Oxygen Method". The results are shown in Table 1.

[0040] Rust prevention test: The rust prevention performance of the lubricating oil compositions of Examples 1-3 and Comparative Examples 1-4 was tested according to the method of GB / T11143-2008 "Test method for rust prevention performance of mineral oil with inhibitor in the presence of water". The results are shown in Table 1.

[0041] Table 1. Test results of wear resistance and oxidation stability of lubricating oil compositions. As shown in Table 1, the lubricating oil compositions prepared in Examples 1-3 of the present invention have good wear resistance and excellent oxidation resistance.

[0042] Compared to Example 1, Comparative Example 1 replaced the extreme pressure anti-wear agent with black phosphorus olefin, Comparative Example 2 replaced the extreme pressure anti-wear agent with a physical mixture of black phosphorus olefin and nano-cerium hydroxide, Comparative Example 3 used Fe-Cu bimetallic organic framework as an antioxidant, and Comparative Example 4 used a physical mixture of Fe-Cu bimetallic organic framework and sodium dioctyl succinate sulfonate as an antioxidant. The wear resistance and oxidation stability of Comparative Examples 1-4 all decreased to varying degrees. The above results indicate that, on the one hand, the present invention can significantly improve the friction reduction and lubrication performance of lubricating oil by adding cerium hydroxide-modified black phosphorus olefin as an extreme pressure anti-wear agent. Specifically, black phosphorus has a unique two-dimensional layered structure, which allows it to slip through interlayer shear forces during friction, thereby reducing friction. Modifying black phosphorus with cerium hydroxide allows nanoparticles to form a high-load-bearing protective film on the friction surface, synergistically reducing friction and wear. Furthermore, cerium hydroxide's high thermal stability, when coated on the black phosphorus surface, prevents oxidation, while black phosphorus's high thermal conductivity facilitates rapid heat dissipation. Together, these two additives ensure good lubrication performance of the lubricating oil even under high-temperature conditions. On the other hand, the composite material prepared in this invention, consisting of sodium dioctyl succinate sulfonate (AOT) and an Fe-Cu bimetallic organic framework, serves as an antioxidant, significantly improving the rust-preventive and antioxidant properties of the lubricating oil. Specifically, bimetallic organic frameworks possess high porosity and high specific surface area, exposing numerous bimetallic active sites that can adsorb and scavenge various reactive oxygen free radicals, thus playing an antioxidant role in lubricating oils. Furthermore, the porous structure enables the loading and slow release of AOT (a surfactant), which ensures the uniform dispersion of the organic framework in the lubricating oil. AOT can also form an adsorption film on the metal surface, synergistically inhibiting metal corrosion with the copper ions released by the organic framework. In addition, the two work together to form a composite film on the surface of the friction pair, which also reduces the coefficient of friction and enhances extreme pressure performance.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. The basic principles and main features of the present invention have been described above with specific implementation schemes. Based on the present invention, some modifications or substitutions can be made, but these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of protection claimed by the present invention.

Claims

1. A lubricating oil composition, characterized in that, It is composed of the following raw materials by weight percentage: extreme pressure anti-wear agent 4-9wt%, antioxidant 2-5wt%, anticoagulant 0.8-1.5wt%, metal deactivator 0.2-0.5wt%, balance base oil; The extreme pressure anti-wear agent is prepared by the following process: Black lepidocrolide and nano-cerium hydroxide were added to acetone and subjected to electrostatic self-assembly under ultrasonic conditions. After centrifugation and drying, the extreme pressure anti-wear agent was obtained.

2. The lubricating oil composition according to claim 1, characterized in that, The mass ratio of melanin to nano-cerium hydroxide is 1:1-10.

3. The lubricating oil composition according to claim 1, characterized in that, The ultrasound power is 30-50W, and the duration is 20-40 minutes.

4. The lubricating oil composition according to claim 1, characterized in that, The antioxidant is prepared by the following process: (1) Add copper salt, iron salt and pyromellitic acid to N,N-dimethylformamide and stir to obtain Fe-Cu bimetallic organic framework precursor solution; (2) Sodium dioctyl succinate sulfonate was added to the Fe-Cu bimetallic organic framework precursor solution and heated to react. After the reaction was completed, the solid substance was filtered out, washed and dried to obtain the antioxidant.

5. The lubricating oil composition according to claim 4, characterized in that, The molar ratio of copper salt, iron salt and pyromellitic acid in step (1) is 1:(2-4):(1-2).

6. The lubricating oil composition according to claim 4, characterized in that, The ratio of sodium dioctyl succinate sulfonate to Fe-Cu bimetallic organic framework precursor solution in step (2) is 0.1 mol: 3-5 L.

7. The lubricating oil composition according to claim 4, characterized in that, The heating reaction in step (2) is carried out at a temperature of 120-160℃ for 20-25 hours.

8. The lubricating oil composition according to claim 1, characterized in that, The anticoagulant is a polyalphaolefin; the metal deactivator is methylbenzotriazole; and the base oil is a polyalkylene glycol.

9. A method for preparing a lubricating oil composition according to any one of claims 1-8, characterized in that, Includes the following steps: Weigh each raw material according to the stated weight percentage, mix them evenly, and obtain the lubricating oil composition.

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