An antioxidant lubricating oil composition and a method for preparing the same

Abstract

The present application relates to the technical field of lubricating oil, in particular to an antioxidant lubricating oil composition and a preparation method thereof, which comprises the following raw materials by weight: 75-80 parts of paraffin base oil, 2.5-3 parts of antioxidant lubricating filler, 3-4 parts of active additive, 1.8-2 parts of viscosity modifier, 0.8-1 part of pour point depressant, 0.08-0.1 part of defoaming agent and 0.8-1 part of rust inhibitor; the phosphate antioxidant is grafted on the filler in a covalent bonding manner, and is compounded with the boric acid ester active additive, and is added in the base oil, so that the antioxidant performance of the lubricating oil is greatly improved, and the introduction of the active additive enables the lubricating oil to have better and longer stable high-temperature lubricating performance.

Description

Technical Field

[0001] This invention relates to the field of lubricating oil technology, and more specifically to an antioxidant lubricating oil composition and its preparation method. Background Technology

[0002] As we all know, one of the core functions of lubricating oil is to reduce friction and wear between mechanical parts. Reducing friction directly means improving mechanical efficiency, thereby reducing energy consumption. The use of lubricating oil can reduce energy loss, which directly corresponds to less greenhouse gas (especially carbon dioxide) emissions, achieving a low-carbon emission effect.

[0003] Studies have found that paraffinic base oils occupy the vast majority of the lubricating oil market share due to their excellent viscosity-temperature properties, low cost, and wide availability. However, because their molecular structure contains a large number of alkane chains, they are prone to oxidation chain reactions under high temperature, oxygen, and metal ion catalysis, leading to changes in viscosity, clogging of oil passages, accumulation of acidic substances, accelerated corrosion of metal parts, and the formation of deposits, resulting in equipment wear. For example, patent CN116042287B, "A Wear-Resistant and Anti-Oxidation Lubricating Oil and Its Preparation Method and Application," describes the following technical solution: it improves the oxidation resistance of lubricating oil by adding a phosphorus-containing anti-wear agent. However, researchers have further discovered that the above solution usually adds various fillers to improve the lubrication performance of the lubricating oil, but phosphate ester antioxidants are difficult to synergize with fillers, easily leading to agglomeration and oxidation, thus reducing their performance. Therefore, a lubricating oil composition with excellent anti-oxidation properties is needed. Summary of the Invention

[0004] The purpose of this invention is to provide an antioxidant lubricating oil composition and its preparation method. The composition involves grafting phosphate ester antioxidants onto fillers in a covalent manner and compounding them with borate ester active additives, which are then added to base oil. This greatly improves the antioxidant properties of the lubricating oil, and the introduction of active additives enables it to exhibit better and longer-lasting stable high-temperature lubrication performance.

[0005] The objective of this invention can be achieved through the following technical solution: a method for preparing an antioxidant lubricating oil composition, comprising the following steps: weighing the following raw materials in parts by weight: 75-80 parts paraffinic base oil, 2.5-3 parts antioxidant lubricating filler, 3-4 parts active additive, 1.8-2 parts viscosity modifier, 0.8-1 part pour point depressant, 0.08-0.1 parts defoamer, and 0.8-1 part rust inhibitor; mixing the paraffinic base oil, antioxidant lubricating filler, active additive, viscosity modifier, pour point depressant, defoamer, and rust inhibitor, and ultrasonically dispersing for 15-20 minutes to obtain an antioxidant lubricating oil composition;

[0006] The paraffin base oil is from Qingyang and has a specification of 150SN.

[0007] The viscosity improver is Viscotech 533;

[0008] The pour point depressant is from Sanyo Chemicals, and its specification is AclubeP-2100;

[0009] The defoamer is from Evonik, and its specification is Antifoam793.

[0010] The rust inhibitor is from Jufan Industrial Co., Ltd., and its specification is TS-6.

[0011] The active additive is prepared by the following steps:

[0012] Step A1: Mix 3,5-di-tert-butyl-2-hydroxybenzaldehyde, N-phenyl-p-phenylenediamine and ethanol, and react under nitrogen protection, stirring at 120-140 rpm and at 70°C for 2-3 hours to obtain the intermediate.

[0013] Step A2: Mix benzotriazole, formaldehyde solution and deionized water, and react at a stirring rate of 120-140 rpm and a temperature of 80℃ for 30-40 min. Rotary evaporate, filter to obtain filter cake. Mix filter cake, boric acid and toluene, and react at a stirring rate of 120-140 rpm and a temperature of 110℃ for 1.5-2 h. Add intermediate, heat to 115℃, and continue to react for 2-3 h. Distill under reduced pressure, filter, wash to obtain active additive.

[0014] Furthermore, in step A1: the ratio of 3,5-di-tert-butyl-2-hydroxybenzaldehyde, N-phenyl-p-phenylenediamine, and ethanol is 2.3-2.4 g : 1.85-1.9 g : 40-45 mL;

[0015] Furthermore, in step A2, the ratio of benzotriazole, formaldehyde solution, deionized water, boric acid, toluene, and intermediate is 2.4-2.42g: 45-50mL: 15-20mL: 0.61-0.62g: 35-40mL: 4.2-4.3g, and the mass fraction of formaldehyde solution is 36%.

[0016] Furthermore, during the reaction, the aldehyde group in 3,5-di-tert-butyl-2-hydroxybenzaldehyde reacts with the primary amine group in N-phenyl-p-phenylenediamine to form a Schiff base structure, thus obtaining an intermediate. Benzotriazole reacts with formaldehyde to form a hydroxyl-containing intermediate, which then reacts with boric acid to form a borate ester structure. The intermediate is then added and reacts with the phenolic hydroxyl group in the intermediate to form an active additive containing boron nitrogen coordination and a Schiff base structure.

[0017]

[0018] The antioxidant lubricating filler is prepared by the following steps:

[0019] Step B1: Mix graphene oxide, phosphomolybdic acid and deionized water, and ultrasonically disperse for 30-35 min. Under the conditions of stirring at 300-400 rpm and room temperature, stir and add hexadecyltrimethylammonium bromide, stir for 15-20 min, then add L-cysteine ​​solution, ultrasonically disperse for 10-15 min, transfer to a reaction vessel, react at 180℃ for 24 h, filter, wash, dry, and then transfer to a tube furnace. Under nitrogen protection, heat to 750℃ at 5℃ / min, hold for 2 h, grind to obtain precursor 1;

[0020] Step B2: Mix precursor 1 with hydrogen peroxide solution and ultrasonically disperse for 15-20 min, let stand for 12 h, filter, and dry to obtain precursor 2. Mix precursor 2, deionized water and ethanol, and ultrasonically disperse for 40-50 min. Under the conditions of stirring speed of 120-180 rpm and temperature of room temperature, stir and add ferric chloride tetrahydrate and ferric chloride hexahydrate, stir for 15-20 min, heat to 80℃, stir and add ammonia water, react for 30-40 min, centrifuge, filter, wash, and dry to obtain precursor 3.

[0021] Step B3: Mix precursor 3 and isopropanol and ultrasonically disperse for 15-20 min. Under the conditions of stirring speed of 120-180 rpm and temperature of 60℃, stir and add O,O-diisooctyl dithiophosphate. React for 24 h, centrifuge, filter, wash, and dry to obtain antioxidant lubricating filler.

[0022] Furthermore, in step B1: the ratio of graphene oxide, phosphomolybdic acid, deionized water, hexadecyltrimethylammonium bromide, and L-cysteine ​​solution is 0.04-0.05g: 0.46-0.48g: 20-25mL: 0.008-0.01g: 8-10mL, and the mass concentration of L-cysteine ​​solution is 0.08g / mL;

[0023] The graphene oxide is from Pioneer Nano, with the product number XFSG01;

[0024] Further, in step B2: the ratio of precursor 1 to hydrogen peroxide solution is 0.45-0.5g:30-35mL, the molar concentration of hydrogen peroxide solution is 5mol / L, and the ratio of precursor 2, deionized water, ethanol, ferric chloride tetrahydrate, ferric chloride hexahydrate, and ammonia is 0.1-0.12g:50-60mL:50-60mL:0.14-0.15g:0.36-0.37g:20-25mL, and the mass fraction of ammonia is 15%.

[0025] Furthermore, in step B3: the ratio of precursor 3, isopropanol and O,O-diisooctyl dithiophosphate is 0.14-0.16g: 80-100mL: 25-30mL.

[0026] Furthermore, during the reaction, phosphomolybdic acid was used as the molybdenum source, L-cysteine ​​solution as the sulfur source and reducing agent, and hexadecyltrimethylammonium bromide as the dopant and surfactant. Molybdenum disulfide was loaded onto a graphene oxide substrate using a hydrothermal method, followed by calcination to obtain precursor 1. Precursor 1 was then immersed in hydrogen peroxide solution. Due to the doping of hexadecyltrimethylammonium bromide during the preparation of molybdenum disulfide, defects appeared in the molybdenum disulfide. Simultaneously, etching with hydrogen peroxide solution created sulfur atom vacancies on the surface, resulting in precursor 2. Then, using a hydrothermal method, ferric chloride tetrahydrate and ferric chloride hexahydrate were used as iron sources to load iron(III) oxide onto its surface, resulting in precursor 3. Finally, through the reaction of sulfur atom vacancy defects with the thiol groups in O,O-diisooctyl dithiophosphate, it was grafted onto precursor 3 to obtain an antioxidant lubricating filler.

[0027] The beneficial effects of the present invention are as follows: The present invention discloses an antioxidant lubricating oil composition and its preparation method, which involves grafting phosphate ester antioxidants onto fillers in a covalent manner and compounding them with borate ester active additives, and adding them to base oil, thereby greatly improving the antioxidant performance of the lubricating oil. Furthermore, the introduction of active additives enables it to exhibit better and longer-lasting stable high-temperature lubrication performance.

[0028] Antioxidant lubricating fillers are based on graphene oxide and loaded with molybdenum disulfide containing defect sites. Simultaneously, magnetic iron oxide particles are generated in situ, and antioxidants are grafted onto these defect sites. The introduction of magnetic iron oxide particles significantly improves the filler's loading capacity. Due to its synthesis method, these particles are evenly distributed and isolated on the substrate, resulting in friction reduction. The magnetism of the magnetic iron oxide particles allows the filler to adhere more effectively to the metal contact surface, stabilizing and facilitating lubrication. Its unique structure allows the magnetic iron oxide particles to act as "micro-bearings," altering the friction pattern and further reducing friction loss. After covalent grafting with phosphate ester antioxidants, they are firmly fixed to the substrate and compounded with borate ester active additives. Since the active additives are boron-nitrogen coordinated compounds with Schiff base structures, they exhibit synergistic effects, greatly enhancing the antioxidant properties of the lubricating oil. The active additives themselves also exhibit anti-wear properties, further improving the lubrication effect of the lubricating oil. Detailed Implementation

[0029] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] Example 1: A method for preparing an antioxidant lubricating oil composition, comprising the following steps: weighing the following raw materials in parts by weight: 75 parts paraffinic base oil, 2.5 parts antioxidant lubricating filler, 3 parts active additive, 1.8 parts viscosity modifier, 0.8 parts pour point depressant, 0.08 parts defoamer, and 0.8 parts rust inhibitor; mixing the paraffinic base oil, antioxidant lubricating filler, active additive, viscosity modifier, pour point depressant, defoamer, and rust inhibitor, and ultrasonically dispersing for 15 minutes to obtain an antioxidant lubricating oil composition;

[0031] The paraffin base oil is from Qingyang and has a specification of 150SN.

[0032] The viscosity improver is Viscotech 533;

[0033] The pour point depressant is from Sanyo Chemicals, and its specification is AclubeP-2100;

[0034] The defoamer is from Evonik, and its specification is Antifoam793.

[0035] The rust inhibitor is from Jufan Industrial Co., Ltd., and its specification is TS-6.

[0036] The active additive is prepared by the following steps:

[0037] Step A1: Mix 3,5-di-tert-butyl-2-hydroxybenzaldehyde, N-phenyl-p-phenylenediamine and ethanol, and react for 2 hours under nitrogen protection, stirring at 120 rpm and at 70°C to obtain the intermediate.

[0038] Step A2: Mix benzotriazole, formaldehyde solution and deionized water, and react for 30 min at a stirring rate of 120 rpm and a temperature of 80 °C. Rotary evaporate, filter to obtain filter cake. Mix filter cake, boric acid and toluene, and react for 1.5 h at a stirring rate of 120 rpm and a temperature of 110 °C. Then add intermediate, raise the temperature to 115 °C and continue to react for 2 h. Distill under reduced pressure, filter, wash to obtain active additive.

[0039] Furthermore, in step A1: the ratio of 3,5-di-tert-butyl-2-hydroxybenzaldehyde, N-phenyl-p-phenylenediamine, and ethanol is 2.3 g: 1.85 g: 40 mL;

[0040] Furthermore, in step A2, the ratio of benzotriazole, formaldehyde solution, deionized water, boric acid, toluene, and intermediate is 2.4g:45mL:15mL:0.6g:35mL:4.2g, and the mass fraction of formaldehyde solution is 36%.

[0041] The antioxidant lubricating filler is prepared by the following steps:

[0042] Step B1: Mix graphene oxide, phosphomolybdic acid and deionized water, and ultrasonically disperse for 35 min. Under the conditions of stirring at 300 rpm and room temperature, stir and add hexadecyltrimethylammonium bromide, stir for 15 min, then add L-cysteine ​​solution, ultrasonically disperse for 15 min, transfer to a reaction vessel, react at 180℃ for 24 h, filter, wash, dry, and then transfer to a tube furnace. Under nitrogen protection, heat to 750℃ at 5℃ / min, hold for 2 h, grind to obtain precursor 1;

[0043] Step B2: Mix precursor 1 with hydrogen peroxide solution and ultrasonically disperse for 15 min, let stand for 12 h, filter, and dry to obtain precursor 2. Mix precursor 2, deionized water and ethanol, and ultrasonically disperse for 40 min. Under the conditions of stirring speed of 180 rpm and temperature of room temperature, stir and add ferric chloride tetrahydrate and ferric chloride hexahydrate, stir for 15 min, heat to 80℃, stir and add ammonia water, react for 40 min, centrifuge, filter, wash, and dry to obtain precursor 3.

[0044] Step B3: Mix precursor 3 and isopropanol and ultrasonically disperse for 20 min. Under the conditions of stirring speed of 120 rpm and temperature of 60℃, stir and add O,O-diisooctyl dithiophosphate hydrogen ester. React for 24 h, centrifuge, filter, wash, and dry to obtain antioxidant lubricating filler.

[0045] Furthermore, in step B1: the ratio of graphene oxide, phosphomolybdic acid, deionized water, hexadecyltrimethylammonium bromide and L-cysteine ​​solution is 0.04g:0.48g:20mL:0.008g:10mL, and the mass concentration of L-cysteine ​​solution is 0.08g / mL;

[0046] The graphene oxide is from Pioneer Nano, with the product number XFSG01;

[0047] Furthermore, in step B2: the ratio of precursor 1 to hydrogen peroxide solution is 0.5g:30mL, the molar concentration of hydrogen peroxide solution is 5mol / L, and the ratio of precursor 2, deionized water, ethanol, ferric chloride tetrahydrate, ferric chloride hexahydrate, and ammonia is 0.12g:50mL:60mL:0.15g:0.37g:20mL, with ammonia mass fraction of 15%.

[0048] Furthermore, in step B3: the ratio of precursor 3, isopropanol and O,O-diisooctyl dithiophosphate is 0.14g:100mL:25mL.

[0049] Example 2 A method for preparing an antioxidant lubricating oil composition, comprising the following steps: weighing the following raw materials in parts by weight: 80 parts paraffinic base oil, 2.5 parts antioxidant lubricating filler, 3 parts active additive, 2 parts viscosity modifier, 0.8 parts pour point depressant, 0.1 parts defoamer, and 0.8 parts rust inhibitor; mixing the paraffinic base oil, antioxidant lubricating filler, active additive, viscosity modifier, pour point depressant, defoamer, and rust inhibitor, and ultrasonically dispersing for 20 minutes to obtain an antioxidant lubricating oil composition;

[0050] The paraffin base oil is from Qingyang and has a specification of 150SN.

[0051] The viscosity improver is Viscotech 533;

[0052] The pour point depressant is from Sanyo Chemicals, and its specification is AclubeP-2100;

[0053] The defoamer is from Evonik, and its specification is Antifoam793.

[0054] The rust inhibitor is from Jufan Industrial Co., Ltd., and its specification is TS-6.

[0055] The active additive is prepared by the following steps:

[0056] Step A1: Mix 3,5-di-tert-butyl-2-hydroxybenzaldehyde, N-phenyl-p-phenylenediamine and ethanol, and react under nitrogen protection, stirring at 140 rpm and at 70 °C for 2 h to obtain the intermediate.

[0057] Step A2: Mix benzotriazole, formaldehyde solution and deionized water, and react for 30 min at a stirring rate of 140 rpm and a temperature of 80 °C. Rotary evaporate, filter to obtain filter cake. Mix filter cake, boric acid and toluene, and react for 2 h at a stirring rate of 140 rpm and a temperature of 110 °C. Add intermediate, raise the temperature to 115 °C and continue to react for 2 h. Distill under reduced pressure, filter, wash to obtain active additive.

[0058] Furthermore, in step A1: the ratio of 3,5-di-tert-butyl-2-hydroxybenzaldehyde, N-phenyl-p-phenylenediamine, and ethanol is 2.4 g: 1.9 g: 40 mL;

[0059] Furthermore, in step A2, the ratio of benzotriazole, formaldehyde solution, deionized water, boric acid, toluene, and intermediate is 2.42g:45mL:15mL:0.62g:35mL:4.2g, and the mass fraction of formaldehyde solution is 36%.

[0060] The antioxidant lubricating filler is prepared by the following steps:

[0061] Step B1: Mix graphene oxide, phosphomolybdic acid and deionized water, and ultrasonically disperse for 30 min. Under the conditions of stirring at 300 rpm and room temperature, stir and add hexadecyltrimethylammonium bromide, stir for 15 min, then add L-cysteine ​​solution, ultrasonically disperse for 10 min, transfer to a reaction vessel, react at 180℃ for 24 h, filter, wash, dry, and then transfer to a tube furnace. Under nitrogen protection, heat to 750℃ at 5℃ / min, hold for 2 h, grind to obtain precursor 1;

[0062] Step B2: Mix precursor 1 with hydrogen peroxide solution and ultrasonically disperse for 15 min, let stand for 12 h, filter, and dry to obtain precursor 2. Mix precursor 2, deionized water and ethanol, and ultrasonically disperse for 40 min. Under the conditions of stirring speed of 120 rpm and temperature of room temperature, stir and add ferric chloride tetrahydrate and ferric chloride hexahydrate, stir for 15 min, heat to 80℃, stir and add ammonia water, react for 30 min, centrifuge, filter, wash, and dry to obtain precursor 3.

[0063] Step B3: Mix precursor 3 and isopropanol and ultrasonically disperse for 15 min. Under the conditions of stirring speed of 120 rpm and temperature of 60℃, stir and add O,O-diisooctyl dithiophosphate. React for 24 h, centrifuge, filter, wash, and dry to obtain antioxidant lubricating filler.

[0064] Furthermore, in step B1: the ratio of graphene oxide, phosphomolybdic acid, deionized water, hexadecyltrimethylammonium bromide and L-cysteine ​​solution is 0.04g:0.46g:20mL:0.008g:8mL, and the mass concentration of L-cysteine ​​solution is 0.08g / mL;

[0065] The graphene oxide is from Pioneer Nano, with the product number XFSG01;

[0066] Furthermore, in step B2: the ratio of precursor 1 to hydrogen peroxide solution is 0.45g:30mL, the molar concentration of hydrogen peroxide solution is 5mol / L, and the ratio of precursor 2, deionized water, ethanol, ferric chloride tetrahydrate, ferric chloride hexahydrate, and ammonia is 0.1g:50mL:50mL:0.14g:0.36g:20mL, with ammonia mass fraction of 15%.

[0067] Furthermore, in step B3: the ratio of precursor 3, isopropanol and O,O-diisooctyl dithiophosphate is 0.14g:80mL:25mL.

[0068] Example 3 A method for preparing an antioxidant lubricating oil composition, comprising the following steps: weighing the following raw materials in parts by weight: 80 parts paraffinic base oil, 3 parts antioxidant lubricating filler, 4 parts active additive, 2 parts viscosity modifier, 1 part pour point depressant, 0.1 part defoamer, and 1 part rust inhibitor; mixing the paraffinic base oil, antioxidant lubricating filler, active additive, viscosity modifier, pour point depressant, defoamer, and rust inhibitor, and ultrasonically dispersing for 20 minutes to obtain an antioxidant lubricating oil composition;

[0069] The paraffin base oil is from Qingyang and has a specification of 150SN.

[0070] The viscosity improver is Viscotech 533;

[0071] The pour point depressant is from Sanyo Chemicals, and its specification is AclubeP-2100;

[0072] The defoamer is from Evonik, and its specification is Antifoam793.

[0073] The rust inhibitor is from Jufan Industrial Co., Ltd., and its specification is TS-6.

[0074] The active additive is prepared by the following steps:

[0075] Step A1: Mix 3,5-di-tert-butyl-2-hydroxybenzaldehyde, N-phenyl-p-phenylenediamine and ethanol, and react for 3 hours under nitrogen protection, stirring at 140 rpm and at 70°C to obtain the intermediate.

[0076] Step A2: Mix benzotriazole, formaldehyde solution and deionized water, and react for 40 min at a stirring rate of 140 rpm and a temperature of 80 °C. Rotary evaporate, filter to obtain filter cake. Mix filter cake, boric acid and toluene, and react for 2 h at a stirring rate of 140 rpm and a temperature of 110 °C. Then add intermediate, raise the temperature to 115 °C and continue to react for 3 h. Distill under reduced pressure, filter, wash to obtain active additive.

[0077] Furthermore, in step A1: the ratio of 3,5-di-tert-butyl-2-hydroxybenzaldehyde, N-phenyl-p-phenylenediamine, and ethanol is 2.4 g: 1.9 g: 45 mL;

[0078] Furthermore, in step A2: the ratio of benzotriazole, formaldehyde solution, deionized water, boric acid, toluene and intermediate is 2.42g:50mL:20mL:0.62g:40mL:4.3g, and the mass fraction of formaldehyde solution is 36%.

[0079] The antioxidant lubricating filler is prepared by the following steps:

[0080] Step B1: Mix graphene oxide, phosphomolybdic acid and deionized water, and ultrasonically disperse for 35 min. Under the conditions of stirring at 400 rpm and room temperature, stir and add hexadecyltrimethylammonium bromide, stir for 20 min, then add L-cysteine ​​solution, ultrasonically disperse for 15 min, transfer to a reaction vessel, react at 180℃ for 24 h, filter, wash, dry, and then transfer to a tube furnace. Under nitrogen protection, heat to 750℃ at 5℃ / min, hold for 2 h, grind to obtain precursor 1;

[0081] Step B2: Mix precursor 1 with hydrogen peroxide solution and ultrasonically disperse for 20 min, let stand for 12 h, filter, and dry to obtain precursor 2. Mix precursor 2, deionized water and ethanol, and ultrasonically disperse for 50 min. Under the conditions of stirring speed of 180 rpm and temperature of room temperature, stir and add ferric chloride tetrahydrate and ferric chloride hexahydrate, stir for 20 min, heat to 80℃, stir and add ammonia water, react for 40 min, centrifuge, filter, wash, and dry to obtain precursor 3.

[0082] Step B3: Mix precursor 3 and isopropanol and ultrasonically disperse for 20 min. Under the conditions of stirring speed of 180 rpm and temperature of 60℃, stir and add O,O-diisooctyl dithiophosphate hydrogen ester. React for 24 h, centrifuge, filter, wash, and dry to obtain antioxidant lubricating filler.

[0083] Furthermore, in step B1: the ratio of graphene oxide, phosphomolybdic acid, deionized water, hexadecyltrimethylammonium bromide and L-cysteine ​​solution is 0.05g:0.48g:25mL:0.01g:10mL, and the mass concentration of L-cysteine ​​solution is 0.08g / mL;

[0084] The graphene oxide is from Pioneer Nano, with the product number XFSG01;

[0085] Furthermore, in step B2: the ratio of precursor 1 to hydrogen peroxide solution is 0.5g:35mL, the molar concentration of hydrogen peroxide solution is 5mol / L, and the ratio of precursor 2, deionized water, ethanol, ferric chloride tetrahydrate, ferric chloride hexahydrate, and ammonia is 0.12g:60mL:60mL:0.15g:0.37g:25mL, with ammonia mass fraction of 15%.

[0086] Furthermore, in step B3: the ratio of precursor 3, isopropanol and O,O-diisooctyl dithiophosphate is 0.16g:100mL:30mL.

[0087] Comparative Example 1: Compared with Example 3, the antioxidant lubricating filler in the preparation process of the antioxidant lubricating oil composition in Example 3 was replaced with a composition of graphene oxide, molybdenum disulfide and phosphate antioxidant. The other steps were the same, wherein the weight ratio of graphene oxide, molybdenum disulfide and phosphate antioxidant was 0.2g:0.1g:5mL.

[0088] The graphene oxide is from Pioneer Nano (item number XFSG01), the molybdenum disulfide is from Zhiheng Zhiyuan (specification 500 mesh), and the phosphate antioxidant is from Kemike (model T202).

[0089] Comparative Example 2: Compared with Example 3, the active additive in the preparation process of the antioxidant lubricating oil composition in Example 3 was replaced with diethanolamine borate, while the other steps were the same.

[0090] The antioxidant lubricating oil compositions prepared in Examples 1, 2, 3, Comparative Example 1, and Comparative Example 2 were subjected to friction and wear tests using a reciprocating friction testing machine (HT-1000). The steel balls were made of Gcr15 with a diameter of 6 mm and a hardness of HRC61, and the steel disc was also made of Gcr15 with a thickness of 4 mm and a hardness of HRC61. The load was 8 N, the speed was 300 r / min, the rotation radius was 5 mm, and the rotational linear velocity was 9.42 m / min. The test temperatures were 30℃, 160℃, and 250℃. The test results are shown in Table 1 below. (Table of Friction Performance Test Results)

[0091] Table 1. Results of Friction Performance Test

[0092]

[0093] As shown in the table, the test results indicate that when comparing Examples 1, 2, and 3 with Comparative Examples 1 and 2, Comparative Example 1, which replaced the antioxidant lubricating filler in the preparation process of the antioxidant lubricating oil composition of Example 3 with a composition of graphene oxide, molybdenum disulfide, and phosphate ester antioxidants, failed to effectively reduce friction and drag under high-temperature conditions due to the lack of a special structure and the covalent grafting of antioxidants, and its wear rate increased rapidly. Comparative Example 2, which replaced the active additive in the preparation process of the antioxidant lubricating oil composition of Example 3 with diethanolamine borate, failed to exert a good compounding effect with the antioxidant lubricating filler, resulting in a certain decline in the performance of Comparative Example 2.

[0094] The antioxidant lubricating oil compositions prepared in Examples 1, 2, 3, Comparative Example 1, and Comparative Example 2 were used to test their antioxidant properties using a high-pressure differential scanning calorimeter. The initial oxidation temperature and oxidation induction period were used to determine their antioxidant properties. In the initial oxidation temperature test, the sample mass was 0.5 mg, the oxygen flow rate was 100 mL / min, the pressure was 3.5 MPa, the initial temperature was room temperature, and the heating rate was 10 °C / min. In the oxidation induction period test, the sample mass was 1.0 mg, the flow rate was 100 mL / min, the initial temperature was room temperature, and the heating rate was 30 °C / min. The test results are shown in Table 2. Mechanical property test results are also provided.

[0095] Table 2 Mechanical Performance Test Results

[0096]

[0097] As shown in the table, comparing Examples 1, 2, and 3 with Comparative Examples 1 and 2, Comparative Example 1 replaced the antioxidant lubricating filler in the preparation process of the antioxidant lubricating oil composition of Example 3 with a composition of graphene oxide, molybdenum disulfide, and phosphate ester antioxidants. Due to the lack of a special structure and the covalent grafting of antioxidants, the initial oxidation temperature of Comparative Example 1 was significantly reduced, and the oxidation induction period was significantly shortened. Comparative Example 2 replaced the active additive in the preparation process of the antioxidant lubricating oil composition of Example 3 with diethanolamine borate. Compared with Example 3, Comparative Example 2 showed a reduced initial oxidation temperature and a shorter oxidation induction period, indicating that there is a good synergistic antioxidant effect between the active additive and the antioxidant lubricating filler.

[0098] In the description of this specification, the references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0099] The above content is merely an example and illustration of the concept of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the concept of the invention, they should all fall within the protection scope of the present invention.

Claims

1. A process for the preparation of an antioxidant lubricating oil composition characterized by: The method comprises the following steps: weighing raw materials in the following weight parts: 75-80 parts of paraffin base oil, 2.5-3 parts of antioxidant lubricating filler, 3-4 parts of active additive, 1.8-2 parts of viscosity modifier, 0.8-1 part of pour point depressant, 0.08-0.1 part of defoaming agent and 0.8-1 part of anti-rust agent; the paraffin base oil, the antioxidant lubricating filler, the active additive, the viscosity modifier, the pour point depressant, the defoaming agent and the anti-rust agent are mixed, and ultrasonic dispersion is carried out for 15-20 min to prepare an antioxidant lubricating oil composition; The active additive is prepared by the following steps: Step A1: 3,5-di-tert-butyl-2-hydroxybenzaldehyde, N-phenyl-p-phenylenediamine and ethanol are mixed, under the condition of nitrogen protection, the stirring speed is 120-140 rpm, the temperature is 70 DEG C, and reaction is carried out for 2-3 h to prepare an intermediate; Step A2: benzotriazole, formaldehyde solution and deionized water are mixed, under the condition of stirring speed of 120-140 rpm and temperature of 80 DEG C, reaction is carried out for 30-40 min, rotary evaporation is carried out, filtration is carried out, the filter cake is obtained, the filter cake, boric acid and toluene are mixed, under the condition of stirring speed of 120-140 rpm and temperature of 110 DEG C, reaction is carried out for 1.5-2 h, the intermediate is added again, the temperature is increased to 115 DEG C, and reaction is continued for 2-3 h, filtration is carried out, washing is carried out, and the active additive is prepared; The antioxidant lubricating filler is prepared by the following steps: Step B1: graphene oxide, phosphomolybdic acid and deionized water are mixed and ultrasonic dispersion is carried out for 30-35 min, under the condition of stirring speed of 300-400 rpm and room temperature, stirring is carried out, cetyltrimethylammonium bromide is added, stirring is carried out for 15-20 min, L-cysteine solution is added, ultrasonic dispersion is carried out for 10-15 min, it is transferred to a reaction kettle, reaction is carried out for 24 h under the condition of temperature of 180 DEG C, filtration is carried out, washing is carried out, drying is carried out, it is moved to a tube furnace, under the condition of nitrogen protection, the temperature is increased to 750 DEG C at a rate of 5 DEG C / min, and heat preservation is carried out for 2 h, grinding is carried out, and the precursor 1 is prepared; Step B2: the precursor 1 and hydrogen peroxide solution are mixed and ultrasonic dispersion is carried out for 15-20 min, standing is carried out for 12 h, filtration is carried out, drying is carried out, the precursor 2 is prepared, the precursor 2, deionized water and ethanol are mixed and ultrasonic dispersion is carried out for 40-50 min, under the condition of stirring speed of 120-180 rpm and room temperature, stirring is carried out, ferric chloride tetrahydrate and ferric chloride hexahydrate are added, stirring is carried out for 15-20 min, the temperature is increased to 80 DEG C, stirring is carried out, ammonia water is added, reaction is carried out for 30-40 min, centrifugal filtration is carried out, washing is carried out, drying is carried out, and the precursor 3 is prepared; Step B3: the precursor 3 and isopropanol are mixed and ultrasonic dispersion is carried out for 15-20 min, under the condition of stirring speed of 120-180 rpm and temperature of 60 DEG C, stirring is carried out, O,O-diisooctyl phosphorodithioate is added, reaction is carried out for 24 h, centrifugal filtration is carried out, washing is carried out, drying is carried out, and the antioxidant lubricating filler is prepared.

2. A process for the preparation of an antioxidant lubricating oil composition according to claim 1, characterized in that: In step A1: the amount ratio of 3,5-di-tert-butyl-2-hydroxybenzaldehyde, N-phenyl-p-phenylenediamine and ethanol is 2.3-2.4 g: 1.85-1.9 g: 40-45 mL.

3. A process for the preparation of an antioxidant lubricating oil composition according to claim 1, characterized in that: In step A2: the amount ratio of benzotriazole, formaldehyde solution, deionized water, boric acid, toluene and intermediate is 2.4-2.42 g: 45-50 mL: 15-20 mL: 0.61-0.62 g: 35-40 mL: 4.2-4.3 g, the mass fraction of formaldehyde solution is 36%.

4. A process for the preparation of an antioxidant lubricating oil composition according to claim 1, characterized in that: In step B1: the amount ratio of graphene oxide, phosphomolybdic acid, deionized water, cetyltrimethylammonium bromide and L-cysteine solution is 0.04-0.05 g: 0.46-0.48 g: 20-25 mL: 0.008-0.01 g: 8-10 mL, the mass concentration of L-cysteine solution is 0.08 g / mL.

5. A process for the preparation of an antioxidant lubricating oil composition according to claim 1, characterized by: In step B2: the amount ratio of precursor 1 and hydrogen peroxide solution is 0.45-0.5 g: 30-35 mL, the molar concentration of hydrogen peroxide solution is 5 mol / L, the amount ratio of precursor 2, deionized water, ethanol, iron dichloride hexahydrate, iron trichloride hexahydrate and ammonia water is 0.1-0.12 g: 50-60 mL: 50-60 mL: 0.14-0.15 g: 0.36-0.37 g: 20-25 mL, the mass fraction of ammonia water is 15%.

6. A process for the preparation of an antioxidant lubricating oil composition according to claim 1, characterized in that: In step B3: the amount ratio of precursor 3, isopropyl alcohol and O,O-diisooctyl dithiophosphoric acid hydrogen ester is 0.14-0.16 g: 80-100 mL: 25-30 mL.

7. An antioxidant lubricating oil composition characterized by: Prepared according to the preparation method of any one of claims 1-6. Prepared according to the preparation method of any one of claims 1-6.

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