High-temperature-corrosion-resistant lubricating oil and preparation method thereof

Abstract

The invention relates to the technical field of lubricating oil, in particular to high-temperature-corrosion-resistant lubricating oil and a preparation method thereof. The high-temperature-corrosion-resistant lubricating oil is prepared from the following raw materials in parts by mass: 130 to 190 parts of base oil, 1 to 5 parts of an anti-wear reagent at extreme pressure, 1 to 5 parts of amino modified graphene, 0.1 to 1 part of an anti-rust agent, 1 to 3 parts of an antioxidant, 0.1 to 1 part of a de-foaming agent, 5 to 15 parts of trioctyl trimellitate, 1 to 5 parts of sodium lignin sulfonate and 1 to 5 parts of sodium bentonite. The high temperature resistance and the viscosity-temperature performance of the lubricating oil can meet the use requirements of a bearing under the working conditions of high speed, high temperature and large load, the wear resistance and the friction reduction of the lubricating oil at high temperature are effectively improved, and meanwhile the preparation method is simple and suitable for large-scale popularization and application.

Description

Technical Field

[0001] The present invention relates to the technical field of lubricating oils, and in particular to a high-temperature corrosion-resistant lubricating oil and a preparation method thereof. Background Art

[0002] As an indispensable functional fluid in the modern industrial system, lubricating oil is widely used in scenarios such as automobile engines, industrial machinery and equipment, and precision instruments. It forms a protective medium on the surface of friction pairs in liquid or semi-solid form, and plays a key role in reducing mechanical wear, conducting heat, keeping components clean, enhancing sealing performance, and buffering impact loads.

[0003] The performance of lubricants directly impacts the operating efficiency, energy consumption, and service life of machinery and equipment. With the acceleration of industrialization and the shift toward higher power density in machinery and equipment, lubrication systems are facing the challenges of demanding operating conditions such as high temperatures, heavy loads, and long operating cycles, placing higher demands on the comprehensive performance of lubricants.

[0004] Currently, lubricants are primarily composed of two components: base oil and functional additives. The base oil, acting as the system's carrier, determines the lubricant's fundamental properties, such as viscosity-temperature characteristics and oxidative stability, through its molecular structure and physical and chemical properties. Functional additives, including extreme pressure anti-wear agents, antioxidants, and dispersants, can specifically address the base oil's performance shortcomings under specific operating conditions.

[0005] When mechanical equipment is in a high-temperature and high-pressure environment, the viscosity of the base oil will drop significantly as the temperature rises, causing the oil film thickness to decrease or even rupture, resulting in direct contact between the metal surfaces and causing severe friction. To cope with this type of boundary lubrication, the industry has long relied on sulfur, phosphorus, and chlorine-based extreme pressure anti-wear agents. These compounds undergo thermal decomposition reactions at the friction interface, forming a protective layer of metal salts such as iron sulfide and iron phosphate with the metal matrix. Although this type of reaction film has a high hardness, its brittle characteristics cause it to continuously peel off during actual friction, causing multiple negative effects: the acidic substances generated by the reaction corrode the metal surface and shorten the service life of key components; wear debris contamination exacerbates oil degradation, forming a vicious cycle of performance degradation; frequent lubricant replacement not only increases operation and maintenance costs, but also creates a large number of hazardous waste disposal problems.

[0006] Traditional lubrication systems have shown obvious lack of adaptability. Providing a lubricant that can maintain anti-wear performance under extreme pressure, has corrosion resistance under high temperature conditions, and has adaptive repair properties is of strategic significance for promoting the development of high-end equipment manufacturing. Summary of the Invention

[0007] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a high-temperature corrosion-resistant lubricating oil and a preparation method thereof.

[0008] A high-temperature corrosion-resistant lubricating oil comprises the following raw materials in parts by mass: 130-190 parts of base oil, 1-5 parts of extreme pressure anti-wear agent, 1-5 parts of amino-modified graphene, 0.1-1 part of rust inhibitor, 1-3 parts of antioxidant, 0.1-1 part of defoaming agent, 5-15 parts of trioctyl trimellitate, 1-5 parts of sodium lignin sulfonate, and 1-5 parts of sodium bentonite.

[0009] Preferably, the base oil comprises: polyalphaolefin and hydrogenated palm oil; the mass ratio of polyalphaolefin to hydrogenated palm oil is 100-150:30-40.

[0010] Preferably, the extreme pressure anti-wear agent comprises: isobutylene sulfide, tri-ethyl hexyl borate, nano-tungsten disulfide, and chelated zinc; the mass ratio of isobutylene sulfide, tri-ethyl hexyl borate, nano-tungsten disulfide, and chelated zinc is 1-3:1:0.1-1:0.1-1.

[0011] Preferably, the chelated zinc is zinc dialkyldithiophosphate.

[0012] Preferably, the rust inhibitor is barium petroleum sulfonate and / or calcium dinonylnaphthalene sulfonate.

[0013] Preferably, the antioxidant comprises: diphenylamine, alkyl diphenylamine, and 2,6-di-tert-butyl-p-cresol; the mass ratio of diphenylamine, alkyl diphenylamine, and 2,6-di-tert-butyl-p-cresol is 0.5-1:0.5-1:1-2.

[0014] Preferably, the defoaming agent is polyether-modified siloxane.

[0015] Preferably, the amino-modified graphene is prepared by the following steps: adding graphene oxide to an ethanol aqueous solution and ultrasonically treating it for 10-30 minutes, adjusting the pH value of the system to 5-6, adding tetrabutyl titanate thereto, continuing ultrasonic treatment at 60-70°C for 1-4 hours, adding a silane coupling agent, stirring at 70-80°C for 1-2 hours, filtering, washing, and vacuum drying.

[0016] More preferably, the mass ratio of graphene oxide, tetrabutyl titanate, and silane coupling agent is 1-5:1-3:0.1-1.

[0017] The preparation method of the above-mentioned high-temperature corrosion-resistant lubricating oil comprises the following steps: S1. Preheating hydrogenated palm oil to a molten state; mixing polyalphaolefin, molten hydrogenated palm oil, and amino-modified graphene under nitrogen protection, and ultrasonically treating at 80-90° C. for 1-2 hours to obtain a premix; S2. Add extreme pressure and anti-wear agent to the premix, stir at 80-88°C for 1-2 hours, add the remaining raw materials, stir evenly, and grind.

[0018] Beneficial effects: The present invention adopts a compound of polyalphaolefin and hydrogenated palm oil as the base oil, which is not only widely available but also can significantly improve the biodegradability of the lubricant. At the same time, the compound with amino-modified graphene can form an adsorption film on the metal surface, thereby isolating the metal from corrosive substances and achieving the effect of inhibiting corrosion. Combined with the effect of trioctyl trimellitate, the lubricant has excellent viscosity during operation in a high-temperature environment and a high performance retention rate in a high-temperature environment.

[0019] The present invention exfoliates graphene oxide and then deposits a nano-titanium dioxide layer on its lamellar structure to enhance thermal conductivity. The surface is treated with a KH550 coupling agent, and the organic chain segments of amino functional groups contained on the surface improve the compatibility of graphene in base oil, so that the amino-modified graphene forms a stable dispersion system in the oil phase, and is conducive to the formation of a directionally arranged interlayer slip structure during the lubrication process. The ball-bearing-like effect of the nanoparticles cooperates with sodium bentonite to form a layered composite structure through ion exchange. The combined effect has excellent anti-wear and self-repairing properties in a high-temperature environment.

[0020] Under high temperature conditions, the extreme pressure anti-wear agent decomposes isobutylene sulfide to generate iron sulfide, which works together with triisooctyl borate to form a boron-containing protective film. Combined with amino-modified graphene, it is adsorbed on the active sites of the metal, synergistically enhancing the extreme pressure performance.

[0021] The present invention not only has high temperature resistance and viscosity-temperature performance that can meet the use requirements of bearings under high speed, high temperature and heavy load conditions, but also effectively improves the anti-wear and friction reduction properties of lubricating oil at high temperatures. At the same time, the preparation method is simple and suitable for large-scale promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a load comparison chart of the four-ball load-bearing capacity of the lubricating oil obtained in Example 5 and Comparative Examples 1-2 before and after heat treatment.

[0023] Figure 2 The figure is a comparison chart of the coking quality and viscosity index of the lubricating oils obtained in Example 5 and Comparative Examples 1-2. DETAILED DESCRIPTION

[0024] The present invention will be further explained below with reference to specific embodiments.

[0025] The polyalphaolefin used below was purchased from Hubei Moufeng Chemical Co., Ltd. with CAS number 68037-01-4.

[0026] Example 1

[0027] A high-temperature corrosion-resistant lubricating oil, whose raw materials include: 100g of polyalphaolefin, 30g of hydrogenated palm oil, 1g of extreme pressure anti-wear agent, 1g of amino-modified graphene, 0.1g of barium petroleum sulfonate, 1g of antioxidant, 0.1g of BYK024 defoaming agent, 5g of trioctyl trimellitate, 1g of sodium lignin sulfonate, and 1g of sodium bentonite.

[0028] The extreme pressure and anti-wear agent is composed of sulfided isobutylene, triethylhexyl borate, nano-tungsten disulfide, and zinc dialkyl dithiophosphate in a mass ratio of 1:1:0.1:0.1. The antioxidant is composed of diphenylamine, alkyl diphenylamine, and 2,6-di-tert-butyl-p-cresol in a mass ratio of 0.5:0.5:1.

[0029] Amino-modified graphene was prepared by the following steps: 1 g of graphene oxide was added to 30 g of 40% ethanol aqueous solution and ultrasonically treated for 10 minutes at an ultrasonic frequency of 30 kHz. The pH value of the system was adjusted to 5-6 using 1 mol / L acetic acid solution. 1 g of tetrabutyl titanate was added thereto and ultrasonic treatment was continued at a temperature of 60°C for 1 hour. 0.1 g of KH550 coupling agent was added and stirred at a temperature of 70°C for 1 hour at a stirring speed of 100 r / min. The mixture was filtered, washed, and vacuum dried.

[0030] The preparation method of the above-mentioned high-temperature corrosion-resistant lubricating oil comprises the following steps: S1. Preheat hydrogenated palm oil to a molten state; add polyalphaolefin, molten hydrogenated palm oil, and amino-modified graphene to a reactor under nitrogen protection, and ultrasonically treat at a temperature of 80° C. for 1 h at an ultrasonic frequency of 30 kHz to obtain a premix; S2. Add extreme pressure anti-wear agent to the premix, stir at 80°C for 1 hour at a stirring speed of 500 r / min, add the remaining raw materials and stir evenly, stir at a vacuum degree of -0.08 MPa, and grind.

[0031] Example 2

[0032] A high-temperature corrosion-resistant lubricating oil, whose raw materials include: 150g of polyalphaolefin, 40g of hydrogenated palm oil, 5g of extreme pressure anti-wear agent, 5g of amino-modified graphene, 1g of calcium dinonylnaphthalenesulfonate, 3g of antioxidant, 1g of BYK024 defoaming agent, 15g of trioctyl trimellitate, 5g of sodium lignin sulfonate, and 5g of sodium bentonite.

[0033] The extreme pressure anti-wear agent is composed of sulfided isobutylene, triethylhexyl borate, nano-tungsten disulfide, and zinc dialkyl dithiophosphate in a mass ratio of 3:1:1:1. The antioxidant is composed of diphenylamine, alkyl diphenylamine, and 2,6-di-tert-butyl-p-cresol in a mass ratio of 1:1:2.

[0034] Amino-modified graphene was prepared by the following steps: 5 g of graphene oxide was added to 50 g of 60% ethanol aqueous solution and ultrasonically treated for 30 min at an ultrasonic frequency of 50 kHz. The pH value of the system was adjusted to 5-6 using a 2 mol / L acetic acid solution. 3 g of tetrabutyl titanate was added thereto and ultrasonic treatment was continued at a temperature of 70°C for 4 h. 1 g of KH550 coupling agent was added and stirred at a temperature of 80°C for 2 h at a stirring speed of 400 r / min. The mixture was filtered, washed, and vacuum dried.

[0035] The preparation method of the above-mentioned high-temperature corrosion-resistant lubricating oil comprises the following steps: S1. Preheat hydrogenated palm oil to a molten state; add polyalphaolefin, molten hydrogenated palm oil, and amino-modified graphene to a reactor under nitrogen protection, and ultrasonically treat at a temperature of 90° C. for 2 h at an ultrasonic frequency of 50 kHz to obtain a premix; S2. Add extreme pressure anti-wear agent to the premix, stir at 88°C for 2h, stirring at 1500r / min, add the remaining raw materials and stir evenly, stirring at a vacuum degree of -0.1MPa, and grind.

[0036] Example 3

[0037] A high-temperature corrosion-resistant lubricating oil, whose raw materials include: 110g of polyalphaolefin, 37g of hydrogenated palm oil, 2g of extreme pressure anti-wear agent, 4g of amino-modified graphene, 0.3g of barium petroleum sulfonate, 2.5g of antioxidant, 0.2g of BYK024 defoaming agent, 12g of trioctyl trimellitate, 2g of sodium lignin sulfonate, and 4g of sodium bentonite.

[0038] The extreme pressure and anti-wear agent is composed of sulfided isobutylene, triethylhexyl borate, nano-tungsten disulfide, and zinc dialkyl dithiophosphate in a mass ratio of 1.5:1:0.8:0.3. The antioxidant is composed of diphenylamine, alkyl diphenylamine, and 2,6-di-tert-butyl-p-cresol in a mass ratio of 0.9:0.6:1.7.

[0039] Amino-modified graphene was prepared by the following steps: 2 g of graphene oxide was added to 45 g of 45% ethanol aqueous solution and ultrasonically treated for 25 min at an ultrasonic frequency of 35 kHz. The pH value of the system was adjusted to 5-6 using 1.8 mol / L acetic acid solution. 1.5 g of tetrabutyl titanate was added thereto and ultrasonic treatment was continued at a temperature of 68°C for 2 h. 0.8 g of KH550 coupling agent was added and stirred at a temperature of 73°C for 100 min at a stirring speed of 200 r / min. The mixture was filtered, washed, and vacuum dried.

[0040] The preparation method of the above-mentioned high-temperature corrosion-resistant lubricating oil comprises the following steps: S1. Preheat hydrogenated palm oil to a molten state; add polyalphaolefin, molten hydrogenated palm oil, and amino-modified graphene to a reactor under nitrogen protection, and ultrasonically treat at a temperature of 88° C. for 80 min at an ultrasonic frequency of 45 kHz to obtain a premix; S2. Add extreme pressure anti-wear agent to the premix, stir at 82°C for 100 min at a stirring speed of 800 r / min, add the remaining raw materials and stir evenly, stir at a vacuum degree of -0.09 MPa, and grind.

[0041] Example 4

[0042] A high-temperature corrosion-resistant lubricating oil, whose raw materials include: 130g of polyalphaolefin, 33g of hydrogenated palm oil, 4g of extreme pressure anti-wear agent, 2g of amino-modified graphene, 0.2g of barium petroleum sulfonate, 0.5g of calcium dinonylnaphthalene sulfonate, 1.5g of antioxidant, 0.8g of BYK024 defoaming agent, 8g of trioctyl trimellitate, 4g of sodium lignin sulfonate, and 2g of sodium bentonite.

[0043] The extreme pressure and anti-wear agent is composed of sulfided isobutylene, triethylhexyl borate, nano-tungsten disulfide, and zinc dialkyl dithiophosphate in a mass ratio of 2.5:1:0.2:0.7. The antioxidant is composed of diphenylamine, alkyl diphenylamine, and 2,6-di-tert-butyl-p-cresol in a mass ratio of 0.7:0.8:1.3.

[0044] Amino-modified graphene was prepared by the following steps: 4 g of graphene oxide was added to 35 g of 55% ethanol aqueous solution and ultrasonically treated for 15 min at an ultrasonic frequency of 45 kHz. The pH value of the system was adjusted to 5-6 using 1.2 mol / L acetic acid solution. 2.5 g of tetrabutyl titanate was added thereto and ultrasonic treatment was continued at a temperature of 62°C for 3 h. 0.2 g of KH550 coupling agent was added and stirred at a temperature of 77°C for 80 min at a stirring speed of 300 r / min. The mixture was filtered, washed, and vacuum dried.

[0045] The preparation method of the above-mentioned high-temperature corrosion-resistant lubricating oil comprises the following steps: S1. Preheat hydrogenated palm oil to a molten state; add polyalphaolefin, molten hydrogenated palm oil, and amino-modified graphene to a reactor under nitrogen protection, and ultrasonically treat at a temperature of 82° C. for 100 min at an ultrasonic frequency of 35 kHz to obtain a premix; S2. Add extreme pressure anti-wear agent to the premix, stir at 86°C for 80 minutes at a stirring speed of 1200 r / min, add the remaining raw materials and stir evenly, stir at a vacuum degree of -0.09 MPa, and grind.

[0046] Example 5

[0047] A high-temperature corrosion-resistant lubricating oil, whose raw materials include: 120g of polyalphaolefin, 35g of hydrogenated palm oil, 3g of extreme pressure anti-wear agent, 3g of amino-modified graphene, 0.25g of barium petroleum sulfonate, 0.25g of calcium dinonylnaphthalene sulfonate, 2g of antioxidant, 0.5g of BYK024 defoaming agent, 10g of trioctyl trimellitate, 3g of sodium lignin sulfonate, and 3g of sodium bentonite.

[0048] The extreme pressure and anti-wear agent is composed of sulfided isobutylene, triethylhexyl borate, nano-tungsten disulfide, and zinc dialkyl dithiophosphate in a mass ratio of 2:1:0.5:0.5. The antioxidant is composed of diphenylamine, alkyl diphenylamine, and 2,6-di-tert-butyl-p-cresol in a mass ratio of 0.8:0.7:1.5.

[0049] Amino-modified graphene was prepared by the following steps: 3 g of graphene oxide was added to 40 g of 50% ethanol aqueous solution and ultrasonically treated for 20 min at an ultrasonic frequency of 40 kHz. The pH value of the system was adjusted to 5-6 using 1.5 mol / L acetic acid solution. 2 g of tetrabutyl titanate was added thereto and ultrasonic treatment was continued at a temperature of 65°C for 2.5 h. 0.5 g of KH550 coupling agent was added and stirred at a temperature of 75°C for 90 min at a stirring speed of 240 r / min. The mixture was filtered, washed, and vacuum dried.

[0050] The preparation method of the above-mentioned high-temperature corrosion-resistant lubricating oil comprises the following steps: S1. Preheat hydrogenated palm oil to a molten state; add polyalphaolefin, molten hydrogenated palm oil, and amino-modified graphene to a reactor under nitrogen protection, and ultrasonically treat at a temperature of 85° C. for 90 min at an ultrasonic frequency of 40 kHz to obtain a premix; S2. Add extreme pressure anti-wear agent to the premix, stir at 84°C for 90 minutes at a stirring speed of 1000 r / min, add the remaining raw materials and stir evenly, stir at a vacuum degree of -0.09 MPa, and grind.

[0051] Comparative Example 1

[0052] A high-temperature corrosion-resistant lubricating oil, whose raw materials include: 120g of polyalphaolefin, 35g of hydrogenated palm oil, 3g of extreme pressure anti-wear agent, 3g of amino-modified graphene, 0.25g of barium petroleum sulfonate, 0.25g of calcium dinonylnaphthalene sulfonate, 2g of antioxidant, 0.5g of BYK024 defoaming agent, 10g of trioctyl trimellitate, 3g of sodium lignin sulfonate, and 3g of sodium bentonite.

[0053] The extreme pressure and anti-wear agent is composed of sulfided isobutylene, triethylhexyl borate, nano-tungsten disulfide, and zinc dialkyl dithiophosphate in a mass ratio of 2:1:0.5:0.5. The antioxidant is composed of diphenylamine, alkyl diphenylamine, and 2,6-di-tert-butyl-p-cresol in a mass ratio of 0.8:0.7:1.5.

[0054] Amino-modified graphene was prepared by the following steps: 3 g of graphene oxide was added to 40 g of 50% ethanol aqueous solution and ultrasonically treated for 20 min at an ultrasonic frequency of 40 kHz. The pH value of the system was adjusted to 5-6 with a 1.5 mol / L acetic acid solution. 0.5 g of KH550 coupling agent was added, and the mixture was stirred at 75°C for 90 min at a stirring speed of 240 r / min. The mixture was filtered, washed, and vacuum dried.

[0055] The preparation method of the above-mentioned high-temperature corrosion-resistant lubricating oil comprises the following steps: S1. Preheat hydrogenated palm oil to a molten state; add polyalphaolefin, molten hydrogenated palm oil, and amino-modified graphene to a reactor under nitrogen protection, and ultrasonically treat at a temperature of 85° C. for 90 min at an ultrasonic frequency of 40 kHz to obtain a premix; S2. Add extreme pressure anti-wear agent to the premix, stir at 84°C for 90 minutes at a stirring speed of 1000 r / min, add the remaining raw materials and stir evenly, stir at a vacuum degree of -0.09 MPa, and grind.

[0056] Comparative Example 2

[0057] A high-temperature corrosion-resistant lubricating oil, whose raw materials include: 120g of polyalphaolefin, 35g of hydrogenated palm oil, 3g of extreme pressure anti-wear agent, 3g of amino-modified graphene, 0.25g of barium petroleum sulfonate, 0.25g of calcium dinonylnaphthalene sulfonate, 2g of antioxidant, 0.5g of BYK024 defoaming agent, 10g of trioctyl trimellitate, and 3g of sodium lignin sulfonate.

[0058] The extreme pressure and anti-wear agent is composed of sulfided isobutylene, triethylhexyl borate, nano-tungsten disulfide, and zinc dialkyl dithiophosphate in a mass ratio of 2:1:0.5:0.5. The antioxidant is composed of diphenylamine, alkyl diphenylamine, and 2,6-di-tert-butyl-p-cresol in a mass ratio of 0.8:0.7:1.5.

[0059] Amino-modified graphene was prepared by the following steps: 3 g of graphene oxide was added to 40 g of 50% ethanol aqueous solution and ultrasonically treated for 20 min at an ultrasonic frequency of 40 kHz. The pH value of the system was adjusted to 5-6 using 1.5 mol / L acetic acid solution. 2 g of tetrabutyl titanate was added thereto and ultrasonic treatment was continued at a temperature of 65°C for 2.5 h. 0.5 g of KH550 coupling agent was added and stirred at a temperature of 75°C for 90 min at a stirring speed of 240 r / min. The mixture was filtered, washed, and vacuum dried.

[0060] The preparation method of the above-mentioned high-temperature corrosion-resistant lubricating oil comprises the following steps: S1. Preheat hydrogenated palm oil to a molten state; add polyalphaolefin, molten hydrogenated palm oil, and amino-modified graphene to a reactor under nitrogen protection, and ultrasonically treat at a temperature of 85° C. for 90 min at an ultrasonic frequency of 40 kHz to obtain a premix; S2. Add extreme pressure anti-wear agent to the premix, stir at 84°C for 90 minutes at a stirring speed of 1000 r / min, add the remaining raw materials and stir evenly, stir at a vacuum degree of -0.09 MPa, and grind.

[0061] The four-ball load capacity of the lubricating oils obtained in Example 5 and Comparative Examples 1-2 was measured with reference to GB / T 3142-2019, "Lubricants - Determination of Load Capacity - Four-Ball Method." The lubricating oils obtained in Example 5 and Comparative Examples 1-2 were conditioned at 150°C for 8 hours, and their four-ball load capacity was measured again.

[0062] like Figure 1 As shown, the four-ball load capacity of the lubricating oil obtained in Example 5 is the highest before and after heat treatment, which is better than that of Comparative Examples 1-2 (P < 0.05).

[0063] The copper corrosion rating of the lubricating oils obtained in Example 5 and Comparative Examples 1-2 was measured with reference to GB / T 5096-2017, "Petroleum Products, Copper Strip Corrosion Test Method." The lubricating oils obtained in Example 5 and Comparative Examples 1-2 were exposed to a 150°C environment for 8 hours, and their copper strip corrosion ratings were measured again. The results are shown in Table 1.

[0064] Table 1 Copper sheet corrosion grade of the lubricating oil obtained in Example 5 and Comparative Examples 1-2 before and after heat treatment

[0065] As shown in Table 1, the copper sheet corrosion level of the lubricating oil obtained in Example 5 was the best before and after heat treatment.

[0066] The lubricating oils obtained in Example 5 and Comparative Examples 1-2 were subjected to a coking quality test at 150°C for 20 hours using a lubricating oil high temperature coking performance tester. The viscosity index of the lubricating oils obtained in Example 5 and Comparative Examples 1-2 was measured with reference to ASTM D 2270.

[0067] like Figure 2 As shown, the coke quality of the lubricating oil obtained in Example 5 is the smallest, while the viscosity index is the largest, which is better than that of Comparative Examples 1-2 (P < 0.05).

[0068] The applicant believes that this is because the present invention uses a compound of polyalphaolefin and hydrogenated palm oil as the base oil, which is not only widely available, but also significantly improves the biodegradability of the lubricant. At the same time, compounding with amino-modified graphene can form an adsorption film on the metal surface, thereby isolating the metal from corrosive substances, achieving the effect of inhibiting corrosion. In combination with trioctyl trimellitate, the lubricant has excellent viscosity during high-temperature environment movement and high high-temperature environment performance retention. At the same time, after the graphene oxide is peeled off, the present invention deposits a nano-titanium dioxide layer on its lamellar structure to enhance the thermal conductivity, and the surface is treated with KH550 coupling agent. The organic chain segments of the amino functional groups contained on its surface improve the compatibility of graphene in the base oil, allowing the amino-modified graphene to form a stable dispersion system in the oil phase, while facilitating the formation of an oriented interlayer slip structure during the lubrication process. The ball bearing-like effect of the nanoparticles is coordinated with sodium bentonite to form a layered composite structure through ion exchange. The combined effect has excellent anti-wear and self-repairing properties in high-temperature environments. Under high temperature conditions, the extreme pressure anti-wear agent decomposes isobutylene sulfide to generate iron sulfide, which works together with triisooctyl borate to form a boron-containing protective film. Combined with amino-modified graphene, it is adsorbed on the active sites of the metal, synergistically enhancing the extreme pressure performance.

[0069] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A high temperature corrosion resistant lubricating oil, characterized in that: The raw materials include, by mass, 130-190 parts of base oil, 1-5 parts of extreme pressure anti-wear agent, 1-5 parts of amino-modified graphene, 0.1-1 parts of rust inhibitor, 1-3 parts of antioxidant, 0.1-1 parts of defoaming agent, 5-15 parts of trioctyl trimellitate, 1-5 parts of sodium lignin sulfonate, and 1-5 parts of sodium bentonite.

2. The high temperature corrosion resistant lubricating oil according to claim 1, characterized in that: The base oil includes: polyalphaolefin and hydrogenated palm oil; the mass ratio of polyalphaolefin and hydrogenated palm oil is 100-150:30-40.

3. The high temperature corrosion resistant lubricating oil according to claim 1, characterized in that: The extreme pressure anti-wear agent comprises: isobutylene sulfide, tri-ethylhexyl borate, nano-tungsten disulfide and chelated zinc; the mass ratio of isobutylene sulfide, tri-ethylhexyl borate, nano-tungsten disulfide and chelated zinc is 1-3:1:0.1-1:0.1-1.

4. The high temperature corrosion resistant lubricating oil according to claim 3, characterized in that: The chelated zinc is zinc dialkyl dithiophosphate.

5. The high temperature corrosion resistant lubricating oil according to claim 1, characterized in that: The rust inhibitor is barium petroleum sulfonate and / or calcium dinonylnaphthalene sulfonate.

6. The high temperature corrosion resistant lubricating oil according to claim 1, characterized in that the antioxidant include: The mass ratio of diphenylamine, alkyl diphenylamine and 2,6-di-tert-butyl-p-cresol is 0.5-1:0.5-1:1-2.

7. The high temperature corrosion resistant lubricating oil according to claim 1, characterized in that: The defoamer is polyether modified siloxane.

8. The high temperature corrosion resistant lubricating oil according to claim 1, characterized in that: The amino-modified graphene is prepared by the following steps: adding graphene oxide to an ethanol aqueous solution and ultrasonically treating the solution for 10-30 minutes, adjusting the pH value of the system to 5-6, adding tetrabutyl titanate, and continuing ultrasonic treatment at 60-70° C. for 1-4 hours, adding a silane coupling agent, stirring at 70-80° C. for 1-2 hours, filtering, washing, and vacuum drying.

9. The high temperature corrosion resistant lubricating oil according to claim 1, characterized in that: The mass ratio of graphene oxide, tetrabutyl titanate and silane coupling agent is 1-5:1-3:0.1-1.

10. A method for preparing the high temperature corrosion resistant lubricating oil according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1. Preheating hydrogenated palm oil to a molten state; mixing polyalphaolefin, molten hydrogenated palm oil, and amino-modified graphene under nitrogen protection, and ultrasonically treating at 80-90° C. for 1-2 hours to obtain a premix; S2. Add extreme pressure and anti-wear agent to the premix, stir at 80-88°C for 1-2 hours, add the remaining raw materials, stir evenly, and grind.

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