Speed reducer lubricating oil suitable for new energy automobile and preparation method of speed reducer lubricating oil

Abstract

The invention belongs to the technical field of lubricating oil preparation, and provides speed reducer lubricating oil suitable for a new energy automobile and a preparation method of the speed reducer lubricating oil. Firstly, 2, 4, 6-trichloro-1, 3, 5-triazine serves as a core and reacts with 4-hydroxyphenylboronic acid and sodium hydride to generate a product A containing a triazine and boric acid ester functional structure, then the product A further reacts with phenanthroline and triphenyl phosphate, the multi-coordination triazine boron phosphorus compound is prepared, the compound has excellent high-temperature stability and abrasion resistance, and the service life of the compound is prolonged. The gear surface friction can be obviously reduced; and secondly, on the basis of 2-amino-4, 5-imidazole dinitrile, metallization of n-butyllithium and phosphorus oxychloride reaction are performed to obtain an activated intermediate, and thioester and 4, 4 '-dithiobenzoic acid are introduced to prepare the azacyclo-thiophosphorus polymer which has excellent thermal stability and oxidation resistance.

Description

Technical Field

[0001] The present invention belongs to the technical field of lubricating oil preparation, and relates to a reducer lubricating oil suitable for new energy vehicles and a preparation method thereof. Background Art

[0002] The rapid development of new energy vehicles has driven technological innovation in the automotive industry. Compared with traditional internal combustion engine vehicles, the reducers of new energy vehicles need to withstand higher speeds, greater output torques, and more complex working conditions. This makes the development of reducer lubricants key to improving the performance of new energy vehicles. The design of lubricants in traditional vehicles mainly revolves around the operating characteristics of the internal combustion engine. Its main functions include reducing friction, reducing wear, cooling the engine, and preventing corrosion. However, there are significant differences between the operating conditions of traditional internal combustion engines and the electric drive systems of new energy vehicles, making it difficult for traditional lubricants to fully meet the special needs of new energy vehicle reducers. In internal combustion engine vehicles, the design of lubricants usually needs to deal with complex combustion byproducts, while in new energy vehicles, the power transmission system mainly consists of high-efficiency motors and reducers, and their operating characteristics put forward new requirements for lubricants.

[0003] First, new energy vehicles (NEVs) are centered around electric drive systems. The high speeds of the motors significantly increase the operating frequency and surface sliding speeds of the gears within the reducer, posing new challenges to the lubricant's anti-wear properties, viscosity stability, and thermal-oxidative stability. Specifically, high speeds significantly increase the meshing frequency of the gears, leading to significantly increased contact stress and sliding friction between the gear surfaces. Conventional lubricants can experience a decrease in viscosity or oil film breakdown under high shear stress, rendering them unable to effectively protect the gear surfaces, leading to increased wear and lubrication failure. Furthermore, high speed operation can cause bubbles in the lubricant. These bubbles not only reduce the lubricant's heat transfer capacity but can also cause the lubricant film on the gear surface to break down and increase localized wear. Second, the high operating temperatures and long-duration operation within the reducer require lubricants with enhanced thermal stability and oxidation resistance to prevent degradation that could impact the reducer's lifespan. In NEVs, the high efficiency of the motors generates significant heat, which is transferred through the reducer into the lubricant, significantly increasing its temperature. At high temperatures, lubricating oil can undergo oxidative decomposition, producing acidic substances and insoluble particles. These byproducts can accelerate the corrosion and wear of gears and bearings, seriously affecting the reliability and life of the reducer. Therefore, the development of a lubricant for reducers suitable for new energy vehicles is of great significance. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the present invention aims to provide a reducer lubricant suitable for new energy vehicles and a preparation method thereof. First, 2,4,6-trichloro-1,3,5-triazine is reacted with 4-hydroxyphenylboronic acid to generate an intermediate containing triazine and borate functional units, and a multi-coordinated triazine boron-phosphorus complex is prepared, which effectively reduces the friction and wear of the reducer gear. Secondly, 2-amino-4,5-imidazole dicarbonitrile is used as the core raw material, and its reactivity is enhanced by metallization treatment with n-butyl lithium and reaction with phosphorus oxychloride. Subsequently, it is reacted with thioester and 4,4'-dithiodibenzoic acid to synthesize a nitrogen heterocycle-sulfur phosphorus polymer, which gives the lubricant excellent thermal and chemical stability. Finally, the two composite materials are dispersed in a base oil with additives such as antioxidants and defoamers to prepare a lubricant, thereby meeting the needs of actual production.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention provides a method for preparing a reducer lubricant suitable for new energy vehicles, the preparation method comprising:

[0007] S1, dispersing 2,4,6-trichloro-1,3,5-triazine, 4-hydroxyphenylboric acid, and sodium hydride in xylene, adjusting the temperature to a first temperature after uniform dispersion, stirring and refluxing, filtering while hot after completion of the reaction, and rotary evaporating to obtain product A, dispersing product A, o-phenanthroline, ferrous sulfate, and triethylamine in toluene, mixing uniformly, and then adding triphenyl phosphate, adjusting the temperature to a second temperature, refluxing, and refluxing. After completion of the reaction, maintaining the temperature and performing reduced pressure distillation to obtain a multi-coordinated triazine boron-phosphorus complex;

[0008] S2, under a nitrogen atmosphere and an ice-water bath, dispersing 2-amino-4,5-imidazole dicarbonitrile and n-butyl lithium solution in tetrahydrofuran, stirring evenly, then adding phosphorus oxychloride and removing the ice-water bath, stirring thoroughly, and concentrating under reduced pressure to obtain pre-derivatized 2-amino-4,5-imidazole dicarbonitrile, mixing 1,2,3-triazole-4,5-dicarboxylic acid, methanol, and concentrated sulfuric acid, adjusting the temperature to a second temperature, reacting to generate triazole dicarboxylic acid dimethyl ester, and then mixing triazole dicarboxylic acid dimethyl ester with phosphorus pentasulfide, maintaining the second temperature, and reacting to obtain a thioester, dispersing the pre-derivatized 2-amino-4,5-imidazole dicarbonitrile, the thioester, boron trifluoride etherate, and 4,4'-dithiodibenzoic acid in dimethylformamide, adjusting the temperature to a third temperature for reaction, cooling to 50° C. after the reaction, pouring the reaction solution into deionized water, separating the organic phase, and drying to obtain an nitrogen heterocycle-phosphorus sulfur polymer;

[0009] S3, adding a multi-coordinated triazine boron-phosphorus complex, a nitrogen heterocycle-sulfur-phosphorus polymer, an antioxidant, a defoaming agent, and a rust inhibitor to a base oil, and mixing them evenly to obtain a reducer lubricant suitable for new energy vehicles.

[0010] 2,4,6-Trichloro-1,3,5-triazine reacts with 4-hydroxyphenylboronic acid to form intermediate A. 2,4,6-Trichloro-1,3,5-triazine is a typical nitrogen-aromatic compound. Its triazine ring consists of three nitrogen atoms and three carbon atoms, forming a conjugated aromatic system. The triazine ring's electronic structure gives it strong electron-attracting properties, resulting in a strong electrophilicity of the chlorine atoms on the ring. This electrophilicity makes the chlorine atoms on the triazine ring easily attacked and substituted by nucleophiles. The hydroxyl group in 4-hydroxyphenylboronic acid acts as a nucleophile, which can deprotonate under alkaline conditions to form a negative ion, thus exhibiting stronger nucleophilicity. At the beginning of the reaction, 4-hydroxyphenylboronic acid undergoes a nucleophilic aromatic substitution reaction with the triazine ring. The nucleophilic hydroxyl anion attacks a chlorine atom on the triazine ring, forming a hydroxyphenylboronic acid-modified triazine product. Throughout the reaction, the highly conjugated nature of the triazine ring stabilizes the transition state and lowers the reaction energy barrier, allowing the nucleophilic aromatic substitution reaction to proceed smoothly under relatively mild conditions. To improve the efficiency and selectivity of the reaction, sodium hydride is added to the reaction system as a base. This design serves to capture the hydrogen chloride generated during the reaction, preventing its accumulation in the system and increasing the acidity. The presence of hydrogen chloride significantly reduces the activity of the nucleophile and may attack the triazine ring, leading to side reactions or degradation of the product. Sodium hydride reacts with hydrogen chloride, removing hydrogen chloride from the reaction system, thereby maintaining an alkaline environment and ensuring high activity of the nucleophile. This process improves the reaction yield and increases the purity of the product. The final product is a triazine intermediate bearing a hydroxyphenylboronic acid group, namely, Product A. The introduction of hydroxyphenylboronic acid is of great significance in molecular structure design. First, the introduction of the benzene ring enhances the rigidity of the molecular system through π-π interactions with the triazine ring, thereby improving the mechanical stability of the product, especially under high shear conditions. Second, the boronic acid group provides the molecule with multiple potential reaction sites, which can participate in subsequent chemical reactions through hydrogen bonds or coordination bonds, providing the possibility for further functionalization. Furthermore, the introduction of hydroxyphenylboronic acid enhances the ability of intermolecular interactions, allowing Product A to form more complex three-dimensional molecular networks with other molecules in subsequent reactions.

[0011] Product A undergoes a complex coordination chemical reaction with o-phenanthroline and triphenyl phosphate, further functionalizing it into a multi-coordinated triazine boron-phosphorus complex. O-phenanthroline is a bidentate ligand containing two pyridine rings in its molecular structure. Each nitrogen atom on the pyridine ring possesses a lone pair of electrons, which can form stable coordination bonds with electron-deficient centers (such as nitrogen or boron atoms on the triazine ring). In Product A, both the boronic acid group and the nitrogen atom of the triazine ring provide potential coordination sites. In the presence of ferrous iron, o-phenanthroline, through its bidentate coordination properties, forms an octahedral structure with the ferrous iron ion. The metal coordination center binds to the electron-deficient region of the triazine ring through electrostatic interactions. Triphenyl phosphate forms a BOP covalent bond with the boronic acid group through an ester exchange reaction, constructing a three-dimensional crosslinked network. The phosphorus-oxygen double bond stabilizes free radicals through an inductive effect. Lubricant oxidation is an inevitable problem under high temperature conditions. Phosphates, by capturing free radicals, can effectively inhibit the occurrence of oxidative chain reactions, thereby significantly improving the antioxidant properties of lubricants. Furthermore, the introduction of triphenyl phosphate further enhances the three-dimensional rigidity of the molecular system, resulting in superior stability under high-temperature and high-shear conditions. The triazine ring, as the core skeleton, provides a highly stable chemical structure. The boric acid group and phosphate interact through chemical and coordination bonds to form a multifunctional molecular network. The introduction of o-phenanthroline further enhances the molecule's overall performance, including chemical inertness, thermal stability, and shear stability. This molecular design not only imparts excellent performance to the final product under high-temperature conditions but also provides a sound chemical foundation for its use as a lubricant additive.

[0012] 2-Amino-4,5-imidazole dicarbonitrile was introduced as a starting material into the reaction system. Its molecule contains two nitrile groups and one amino group, providing key reactive sites for subsequent reactions. The high electron density and polarity of the nitrile group, due to its triple bond structure, allow it to participate in a variety of chemical reactions through appropriate activation methods, while the nucleophilicity of the amino group provides additional reactive functionality. Under nitrogen protection and in an ice-water bath, 2-amino-4,5-imidazole dicarbonitrile reacted with n-butyllithium solution. n-Butyllithium is a strongly basic organic reagent that activates the nitrile group by deprotonation, generating a more reactive lithiated nitrile group. This process occurs through electron transfer between the base and the nitrile group, significantly enhancing the nucleophilicity of the nitrile group and providing the necessary chemical activity for the subsequent reaction with thionyl chloride. After activation of the nitrile group by n-butyllithium, phosphorus oxychloride was gradually added to the reaction system. Phosphorus oxychloride is a highly electrophilic reagent, and the unique electron cloud distribution of the phosphorus atom in its molecule makes it extremely reactive toward nucleophiles. When phosphorus oxychloride comes into contact with the lithiated nitrile group, the nucleophilic center (nitrogen atom) of the nitrile group will actively attack the phosphorus atom to generate pre-derivatized 2-amino-4,5-imidazole dicarbonitrile, and the chloride ion leaves to form a PO bond.

[0013] After the pre-derivatization step, the product is introduced into a dimethylformamide solvent. The thioester groups, acting as electrophilic centers, undergo nucleophilic substitution reactions with amino groups in the pre-derivatized product, forming thioamide bonds. Specifically, carboxyl groups react with amino groups via electrophilic attack and dehydration to form amide bonds, while carboxyl groups react with nitrile groups via nucleophilic addition to form ester bonds or other crosslinked structures. The formation of these chemical bonds not only strengthens intermolecular bonding but also significantly enhances the mechanical strength and chemical stability of the polymer. The introduction of the triazole ring provides additional rigidity and electron density to the polymer network. As a nitrogen-containing aromatic ring, the triazole ring has a high π electron density, which enables strong intermolecular interactions with the imidazole ring in the pre-derivatized product through π-π stacking. This interaction helps to build a highly compact molecular network, resulting in enhanced mechanical integrity of the polymer under high shear conditions. Furthermore, the high electron density of the triazole ring enables it to capture free radicals or other oxidative intermediates under oxidative conditions, thereby inhibiting the propagation of the oxidative chain reaction. This property is crucial for improving the polymer's high-temperature oxidation resistance. Boron trifluoride also enhances the π-π stacking between the triazole and imidazole rings through electrostatic interactions with the aromatic rings. This dual effect of catalysis and intermolecular forces further increases the crosslink density and structural rigidity of the molecular network. 4,4'-Dithiodibenzoic acid undergoes free radical addition to the unsaturated bonds in the pre-cured product, forming an SS crosslinked network. The resulting nitrogen-heterocyclic-phosphorus-sulfur polymer exhibits a highly crosslinked three-dimensional network structure, comprising a variety of functional building blocks, including imidazole, triazole, aromatic, phosphorus-sulfur, and amide bonds. These building blocks work synergistically to impart the polymer with exceptional shear resistance and high-temperature oxidation resistance. This enhanced shear resistance is primarily attributed to strong intermolecular interactions, including π-π stacking, hydrogen bonding, and the high strength of chemical crosslinks. These forces collectively create a highly rigid molecular network, enabling the polymer to maintain mechanical integrity and stable performance under high shear conditions. The enhancement of high-temperature oxidation resistance comes from the synergistic effect of sulfur-phosphorus bonds, triazole rings and hydroxyl groups. These structural units can capture oxidative intermediates, inhibit oxidation chain reactions, and resist high-temperature degradation through chemical stability, thereby extending the service life of the material under extreme working conditions.

[0014] The reaction of 2,4,6-trichloro-1,3,5-triazine with 4-hydroxyphenylboronic acid, followed by coordination with ligands such as o-phenanthroline, ferrous sulfate, and triphenyl phosphate, produces a multi-coordinated triazine boron-phosphorus complex. The self-healing ability of this complex stems from the reversibility of its dynamic coordination bonds, particularly the boron-oxygen and iron-nitrogen coordination bonds on the triazine ring, which break and reform under friction or high temperature conditions, thereby enabling the self-repair of damaged structures. Furthermore, the phosphate groups form a stable phosphate protective film on the friction surface, which can re-cover damaged areas through intermolecular self-assembly after wear. The chemical stability of the triazine ring further enhances the material's tolerance under harsh conditions and slows the spread of wear. The reaction of 2-amino-4,5-imidazole dicarbonitrile with a thioester and 4,4'-dithiodibenzoic acid successfully prepared a nitrogen heterocycle-sulfur-phosphorus polymer. The self-healing properties of this material primarily rely on the dynamic covalent bonds in its molecular structure, particularly sulfur-phosphorus and disulfide bonds, which can break and reform under external forces, thereby repairing damage to the material. Furthermore, the high polarity of the nitrogen atoms in the imidazole ring structure can promote hydrogen bonding or ionic interactions between molecules, which enhances the material's ability to recover structural integrity through reassembly after damage.

[0015] As a preferred technical solution of the present invention, in S1, the mass volume ratio of the 2,4,6-trichloro-1,3,5-triazine, 4-hydroxyphenylboric acid, sodium hydride and xylene is (50-60) g: (180-190) g: (12-15) g: 300 mL, for example, it can be (50, 51, 52, 53, 54, 55, 56, 57, 58, 59 or 60) g: ( 180, 181, 182, 183, 184, 185, 186, 187, 188, 189 or 190)g: (12.0, 12.3, 12.6, 12.9, 13.2, 13.5, 13.8, 14.1, 14.4, 14.7 or 15.0)g: 300mL, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0016] In some optional embodiments, the first temperature is 120-130°C, for example, it can be 120°C, 121°C, 122°C, 123°C, 124°C, 125°C, 126°C, 127°C, 128°C, 129°C or 130°C, but is not limited to the listed values, and other unlisted values ​​within the temperature range are also applicable.

[0017] In some optional embodiments, the stirring reflux reaction time is 3-4h, for example, it can be 3h, 3.1h, 3.2h, 3.3h, 3.4h, 3.5h, 3.6h, 3.7h, 3.8h, 3.9h or 4h, but is not limited to the listed times, and other times not listed within the time range are also applicable.

[0018] In some optional embodiments, the mass volume ratio of the product A, o-phenanthroline, ferrous sulfate, triethylamine, toluene and triphenyl phosphate is (80-90) g: (6-10) g: (1-2) g: (4-5) g: 100 mL: (40-45) g, for example, it can be (80, 81, 82, 83, 84, 85, 86, 87, 88, 89 or 90) g: (6.0, 6.4, 6.8, 7.2, 7.6, 8.0, 8.4, 8.8, 9.2, 9.6 or 10.0) g: (1. 0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9 or 2.0)g: (4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9 or 5.0)g: 100mL: (40.0, 40.5, 41.0, 41.5, 42.0, 42.5, 43.0, 43.5, 44.0, 44.5 or 45.0)g, but are not limited to the listed values, and other values ​​not listed within the range are also applicable.

[0019] In some optional embodiments, the second temperature is 90-100°C, for example, it can be 90°C, 91°C, 92°C, 93°C, 94°C, 95°C, 96°C, 97°C, 98°C, 99°C or 100°C, but is not limited to the listed values, and other unlisted values ​​within the temperature range are also applicable.

[0020] In some optional embodiments, the reflux reaction time is 2-3h, for example, it can be 2h, 2.1h, 2.2h, 2.3h, 2.4h, 2.5h, 2.6h, 2.7h, 2.8h, 2.9h or 3h, but is not limited to the listed times, and other times not listed within the time range are also applicable.

[0021] As a preferred technical solution of the present invention, in S2, the mass volume ratio of the 2-amino-4,5-imidazole dicarbonitrile, n-butyl lithium solution, tetrahydrofuran and phosphorus oxychloride is (30-40) g: (56-60) mL: 200 mL: (16-20) g.

[0022] In some optional embodiments, the concentration of the n-butyllithium solution is 2.5 mol / L, and the solvent is n-hexane.

[0023] In some optional embodiments, the mass ratio of 1,2,3-triazole-4,5-dicarboxylic acid, methanol and concentrated sulfuric acid is (10-15):(20-25):(1-2), for example, it can be (10.0, 10.5, 11.0, 11.5, 12.0, 12.5, 13.0, 13.5, 14.0, 14.5 or 15.0):(20.0, 20.5, 21.0, 21.5, 22.0, 22.5, 23.0, 23.5, 24.0, 24.5 or 25.0):(1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9 or 2.0), but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0024] In some optional embodiments, the mass ratio of dimethyl triazoledicarboxylate to phosphorus pentasulfide is 10:(12-15), for example, it can be 10:(12.0, 12.3, 12.6, 12.9, 13.2, 13.5, 13.8, 14.1, 14.4, 14.7 or 15.0), but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0025] In some optional embodiments, the mass volume ratio of the pre-derivatized 2-amino-4,5-imidazole dicarbonitrile, thioester, boron trifluoride etherate, dimethylformamide and 4,4'-dithiodibenzoic acid is (30-35) g: (20-25) g: 2 g: 200 mL: (5-7) g, for example, (30.0, 30.5, 31.0, 31.5, 32.0, 32.5, 33.0, 33.5, 34.0, 35.0, 36.0, 37.0, 38.0, 39.0, 40.0, 41.0, 42.0, 43.0, 44.0, 45.0, 46.0, 47.0, 48.0, 49.0, 50.0, 51.0, 52.0, 53.0, 54.0, 55.0 4.5 or 35.0)g: (20.0, 20.5, 21.0, 21.5, 22.0, 22.5, 23.0, 23.5, 24.0, 24.5 or 25.0)g: 2g: 200mL: (5.0, 5.2, 5.4, 5.6, 5.8, 6.0, 6.2, 6.4, 6.6, 6.8 or 7.0)g, but are not limited to the listed values, other values ​​not listed within the range are also applicable.

[0026] In some optional embodiments, the third temperature is 120-130°C, for example, it can be 120°C, 121°C, 122°C, 123°C, 124°C, 125°C, 126°C, 127°C, 128°C, 129°C or 130°C, but is not limited to the listed values, and other unlisted values ​​within the temperature range are also applicable.

[0027] In some optional embodiments, the third temperature reaction time is 4-5h, for example, it can be 4h, 4.1h, 4.2h, 4.3h, 4.4h, 4.5h, 4.6h, 4.7h, 4.8h, 4.9h or 5h, but is not limited to the listed times, and other unlisted times within the time range are also applicable.

[0028] As a preferred technical solution of the present invention, in S3, the antioxidant is 2,6-di-tert-butyl-p-cresol.

[0029] In some optional embodiments, the defoaming agent is dimethyl silicone oil.

[0030] In some optional embodiments, the rust inhibitor is benzotriazole.

[0031] In some optional embodiments, the base oil is any one of mineral base oil, poly-α-olefin synthetic oil, and ester synthetic oil.

[0032] In some optional embodiments, the mass ratio of the multi-coordinated triazine boron-phosphorus complex, nitrogen heterocycle-sulfur-phosphorus polymer, antioxidant, defoaming agent, rust inhibitor and base oil is 7:5:1:1:1:85.

[0033] In a second aspect, the present invention provides a reducer lubricant suitable for new energy vehicles, which is prepared by the preparation method described in the first aspect.

[0034] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) the multi-coordinated triazine boron-phosphorus complex improves the wear resistance and thermal oxidation stability by introducing functional chemical units such as triazine, borate and phosphate. The high symmetry and chemical inertness of the triazine ring give the complex excellent high-temperature stability, so that it can maintain the integrity of the molecular structure under high temperature environment and is not easy to decompose or fail. The borate and phosphate form a stable lubricating protective film on the metal surface, thereby effectively reducing the friction coefficient and reducing the wear of the gear meshing parts. The phosphate can also provide extreme pressure protection under high load conditions, further improving the extreme working condition adaptability of the lubricant; (2) the nitrogen heterocycle-sulfur phosphorus polymer is formed by the specific chemical structure of imidazole dinitrile, triazole, phosphorus pentasulfide and the like. The introduction of imidazole dinitrile enhances the anti-oxidation and extreme pressure protection properties of the lubricant. The nitrogen heterocyclic structure of imidazole dinitrile has excellent chemical stability and high temperature resistance, which can effectively inhibit the oxidative decomposition of the lubricant at high temperature, thereby avoiding the formation of acidic byproducts and deposits. The sulfur-phosphide structure forms a strong extreme pressure protective film through chemical reaction under high load conditions, significantly enhancing the load-bearing capacity of the lubricant under extreme working conditions and reducing the wear of gears and bearings. (3) The boron-oxygen bond and iron-nitrogen coordination bond in the multi-coordinated triazine boron-phosphorus complex, as well as the sulfur-phosphorus bond and disulfide bond in the nitrogen heterocyclic-sulfur-phosphorus polymer, all have dynamic chemical bond characteristics and can be broken under external force and reformed through thermodynamic drive or catalysis, thereby repairing the damage of the molecular structure. At the same time, the phosphate group and sulfur element form phosphate and sulfide protective films on the friction surface, respectively, which can be rebuilt through molecular migration and self-assembly after surface wear, further reducing wear and repairing damage. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a flow chart of a method for preparing reducer lubricating oil suitable for new energy vehicles provided in Examples 1-4 of the present invention. DETAILED DESCRIPTION

[0036] The technical solutions of the present invention are described in detail below in conjunction with specific embodiments and their accompanying drawings. The embodiments described herein are specific embodiments of the present invention and are used to illustrate the concept of the present invention; these descriptions are explanatory and exemplary and should not be understood as limiting the embodiments of the present invention and the scope of protection of the present invention. In addition to the embodiments described herein, those skilled in the art can also adopt other obvious technical solutions based on the contents disclosed in the claims of this application and its specification, including technical solutions that adopt any obvious replacements and modifications to the embodiments described herein.

[0037] The chemical reagents used in the examples and comparative examples of the present invention are all commercially available products and have not been subjected to any further purification treatment.

[0038] Example 1

[0039] This embodiment provides a reducer lubricant suitable for new energy vehicles, see Figure 1 , and its preparation method specifically comprises the following steps:

[0040] S1, 50g of 2,4,6-trichloro-1,3,5-triazine, 180g of 4-hydroxyphenylboric acid and 12g of sodium hydride were dispersed in 300mL of xylene, and after uniform dispersion, the temperature was adjusted to 128°C, and the mixture was stirred and refluxed for 3.2h. After the reaction was completed, the mixture was filtered while hot and rotary evaporated to obtain product A. 80g of product A, 6g of o-phenanthroline, 1g of ferrous sulfate and 4g of triethylamine were dispersed in 100mL of toluene, mixed uniformly, and 40g of triphenyl phosphate was added. The temperature was adjusted to 90°C, and the mixture was refluxed for 2.5h. After the reaction was completed, the temperature was maintained and the mixture was distilled under reduced pressure to obtain a multi-coordinated triazine boron-phosphorus complex;

[0041] S2, under nitrogen atmosphere and ice-water bath conditions, disperse 30 g of 2-amino-4,5-imidazole dicarbonitrile and 56 mL of n-butyl lithium solution in 200 mL of tetrahydrofuran, stir evenly, then add 16 g of phosphorus oxychloride and remove the ice-water bath. After sufficient stirring, concentrate under reduced pressure to obtain pre-derivatized 2-amino-4,5-imidazole dicarbonitrile. Mix 10 g of 1,2,3-triazole-4,5-dicarboxylic acid, 20 g of methanol and 1 g of concentrated sulfuric acid, adjust the temperature to 90 ° C, and react to generate triazole dicarboxylic acid dimethyl ester. 10 g of dimethyl triazoledicarboxylate was mixed with 12 g of phosphorus pentasulfide and maintained at 90°C to react to obtain a thioester. 30 g of pre-derivatized 2-amino-4,5-imidazole dicarbonitrile, 20 g of the thioester, 2 g of boron trifluoride etherate, and 5 g of 4,4'-dithiodibenzoic acid were dispersed in 200 mL of dimethylformamide and the temperature was adjusted to 122°C for 4.2 h. After the reaction, the temperature was lowered to 50°C, and the reaction solution was poured into deionized water. The organic phase was separated and dried to obtain an nitrogen heterocycle-phosphorus sulfide polymer.

[0042] S3, add 7g of multi-coordinated triazine boron-phosphorus complex, 5g of nitrogen heterocycle-sulfur-phosphorus polymer, 1g of antioxidant, 1g of defoaming agent, and 1g of rust inhibitor to 85g of base oil, and mix them evenly to obtain a reducer lubricant suitable for new energy vehicles.

[0043] Example 2

[0044] This embodiment provides a reducer lubricant suitable for new energy vehicles, and the preparation method thereof specifically includes the following steps:

[0045] S1, 60g of 2,4,6-trichloro-1,3,5-triazine, 190g of 4-hydroxyphenylboric acid and 15g of sodium hydride were dispersed in 300mL of xylene, and after uniform dispersion, the temperature was adjusted to 120°C, and the mixture was stirred and refluxed for 3.0h. After the reaction was completed, the mixture was filtered while hot and rotary evaporated to obtain product A. 90g of product A, 10g of o-phenanthroline, 2g of ferrous sulfate and 5g of triethylamine were dispersed in 100mL of toluene, mixed uniformly, and 45g of triphenyl phosphate was added. The temperature was adjusted to 96°C, and the mixture was refluxed for 2.0h. After the reaction was completed, the temperature was maintained and the mixture was distilled under reduced pressure to obtain a multi-coordinated triazine boron-phosphorus complex;

[0046] S2, under nitrogen atmosphere, in an ice-water bath, disperse 40 g of 2-amino-4,5-imidazole dicarbonitrile and 60 mL of n-butyl lithium solution in 200 mL of tetrahydrofuran, stir evenly, then add 20 g of phosphorus oxychloride and remove the ice-water bath. After sufficient stirring, concentrate under reduced pressure to obtain pre-derivatized 2-amino-4,5-imidazole dicarbonitrile. Mix 15 g of 1,2,3-triazole-4,5-dicarboxylic acid, 25 g of methanol and 2 g of concentrated sulfuric acid, adjust the temperature to 100 ° C, and react to generate dimethyl triazoledicarboxylate. 10 g of dimethyl triazoledicarboxylate was mixed with 15 g of phosphorus pentasulfide and the reaction was maintained at 100°C to obtain a thioester. 35 g of pre-derivatized 2-amino-4,5-imidazole dicarbonitrile, 25 g of the thioester, 2 g of boron trifluoride etherate, and 7 g of 4,4'-dithiodibenzoic acid were dispersed in 200 mL of dimethylformamide. The temperature was adjusted to 128°C and the reaction was carried out for 4.8 hours. After the reaction was completed, the temperature was lowered to 50°C, and the reaction solution was poured into deionized water. The organic phase was separated and dried to obtain an nitrogen heterocycle-phosphorus sulfide polymer.

[0047] S3, add 7g of multi-coordinated triazine boron-phosphorus complex, 5g of nitrogen heterocycle-sulfur-phosphorus polymer, 1g of antioxidant, 1g of defoaming agent, and 1g of rust inhibitor to 85g of base oil, and mix them evenly to obtain a reducer lubricant suitable for new energy vehicles.

[0048] Example 3

[0049] This embodiment provides a reducer lubricant suitable for new energy vehicles, and the preparation method thereof specifically includes the following steps:

[0050] S1, 54g of 2,4,6-trichloro-1,3,5-triazine, 186g of 4-hydroxyphenylboric acid and 14g of sodium hydride were dispersed in 300mL of xylene, and after uniform dispersion, the temperature was adjusted to 124°C, and the mixture was stirred and refluxed for 3.5h. After the reaction was completed, the mixture was filtered while hot and rotary evaporated to obtain product A. 83g of product A, 7g of o-phenanthroline, 1.3g of ferrous sulfate and 4.3g of triethylamine were dispersed in 100mL of toluene, mixed uniformly, and 42g of triphenyl phosphate was added. The temperature was adjusted to 100°C, and the mixture was refluxed for 2.3h. After the reaction was completed, the temperature was maintained and distilled under reduced pressure to obtain a multi-coordinated triazine boron-phosphorus complex;

[0051] S2, under nitrogen atmosphere and ice-water bath conditions, disperse 33 g of 2-amino-4,5-imidazole dicarbonitrile and 57 mL of n-butyl lithium solution in 200 mL of tetrahydrofuran, stir evenly, then add 17 g of phosphorus oxychloride and remove the ice-water bath. After sufficient stirring, concentrate under reduced pressure to obtain pre-derivatized 2-amino-4,5-imidazole dicarbonitrile. Mix 12 g of 1,2,3-triazole-4,5-dicarboxylic acid, 22 g of methanol and 1.3 g of concentrated sulfuric acid, adjust the temperature to 93 ° C, and react to generate dimethyl triazoledicarboxylate. 10 g of dimethyl triazoledicarboxylate was mixed with 13 g of phosphorus pentasulfide and maintained at 93°C to react to obtain a thioester. 31 g of pre-derivatized 2-amino-4,5-imidazole dicarbonitrile, 22 g of the thioester, 2 g of boron trifluoride etherate, and 5.5 g of 4,4'-dithiodibenzoic acid were dispersed in 200 mL of dimethylformamide and the temperature was adjusted to 130°C for 4.0 h. After the reaction, the temperature was lowered to 50°C, and the reaction solution was poured into deionized water. The organic phase was separated and dried to obtain an nitrogen heterocycle-phosphorus sulfide polymer.

[0052] S3, add 7g of multi-coordinated triazine boron-phosphorus complex, 5g of nitrogen heterocycle-sulfur-phosphorus polymer, 1g of antioxidant, 1g of defoaming agent, and 1g of rust inhibitor to 85g of base oil, and mix them evenly to obtain a reducer lubricant suitable for new energy vehicles.

[0053] Example 4

[0054] This embodiment provides a reducer lubricant suitable for new energy vehicles, and the preparation method thereof specifically includes the following steps:

[0055] S1, 57g of 2,4,6-trichloro-1,3,5-triazine, 182g of 4-hydroxyphenylboric acid and 13g of sodium hydride were dispersed in 300mL of xylene, and after uniform dispersion, the temperature was adjusted to 130°C, and the mixture was stirred and refluxed for 4.0h. After the reaction was completed, the mixture was filtered while hot and rotary evaporated to obtain product A. 87g of product A, 8g of o-phenanthroline, 1.7g of ferrous sulfate and 4.6g of triethylamine were dispersed in 100mL of toluene, mixed uniformly, and 43g of triphenyl phosphate was added. The temperature was adjusted to 93°C, and the mixture was refluxed for 3.0h. After the reaction was completed, the temperature was maintained and the mixture was distilled under reduced pressure to obtain a multi-coordinated triazine boron-phosphorus complex;

[0056] S2, under nitrogen atmosphere, in ice-water bath, disperse 37g of 2-amino-4,5-imidazole dicarbonitrile and 56mL of n-butyl lithium solution in 200mL of tetrahydrofuran, stir evenly, then add 19g of phosphorus oxychloride and remove the ice-water bath, stir thoroughly and concentrate under reduced pressure to obtain pre-derivatized 2-amino-4,5-imidazole dicarbonitrile, mix 14g of 1,2,3-triazole-4,5-dicarboxylic acid, 24g of methanol and 1.7g of concentrated sulfuric acid, adjust the temperature to 98°C, react to generate dimethyl triazole dicarboxylate, 10g of triazole dicarbonate The dimethyl carboxylate was then mixed with 14.5 g of phosphorus pentasulfide and maintained at 98°C to react to obtain a thioester. 33 g of pre-derivatized 2-amino-4,5-imidazole dicarbonitrile, 24 g of the thioester, 2 g of boron trifluoride etherate, and 6.5 g of 4,4'-dithiodibenzoic acid were dispersed in 200 mL of dimethylformamide. The temperature was adjusted to 120°C for reaction for 5.0 h, then adjusted to 84°C. After the reaction, the temperature was lowered to 50°C, and the reaction solution was poured into deionized water. The organic phase was separated and dried to obtain an nitrogen heterocycle-phosphorus sulfide polymer.

[0057] S3, add 7g of multi-coordinated triazine boron-phosphorus complex, 5g of nitrogen heterocycle-sulfur-phosphorus polymer, 1g of antioxidant, 1g of defoaming agent, and 1g of rust inhibitor to 85g of base oil, and mix them evenly to obtain a reducer lubricant suitable for new energy vehicles.

[0058] Comparative Example 1

[0059] This comparative example provides a reducer lubricant suitable for new energy vehicles. The difference between it and Example 1 is that the mass of triphenyl phosphate in S1 is 70g, which is 30g more than that in Example 1. The other process parameters and operating conditions are exactly the same as those in Example 1.

[0060] Comparative Example 2

[0061] This comparative example provides a reducer lubricant suitable for new energy vehicles. The difference between it and Example 1 is that the mass of triphenyl phosphate in S1 is 10g, which is 30g less than that in Example 1. The other process parameters and operating conditions are exactly the same as those in Example 1.

[0062] Comparative Example 3

[0063] This comparative example provides a reducer lubricant suitable for new energy vehicles. The difference between it and Example 1 is that the mass of 1,2,3-triazole-4,5-dicarboxylic acid in S2 is 40g, which is 20g more than that in Example 1. The other process parameters and operating conditions are exactly the same as those in Example 1.

[0064] Comparative Example 4

[0065] This comparative example provides a reducer lubricant suitable for new energy vehicles. The difference between it and Example 1 is that the mass of 1,2,3-triazole-4,5-dicarboxylic acid in S2 is 5g, which is 15g less than that in Example 1. The other process parameters and operating conditions are exactly the same as those in Example 1.

[0066] The high-temperature oxidation resistance of lubricating oils (rotating oxygen egg method) was tested according to ASTM D2272, and the shear stability index (SSI) was tested according to SH / T0103-92. The test results are shown in Table 1.

[0067] Table 1 Test results of reducer lubricating oil suitable for new energy vehicles in Examples 1-4 and Comparative Examples 1-4

[0068]

[0069] As shown in Table 1, compared with Example 1, the rotary oxygen bomb time of Comparative Example 1 is reduced and the SSI is increased; the rotary oxygen bomb time of Comparative Example 2 is reduced and the SSI is increased. Excessive triphenyl phosphate in Comparative Example 1 may lead to the generation of by-products (such as incompletely reacted phosphate remaining in the final lubricant), which may have lower thermal stability and accelerate degradation at high temperatures. Excessive phosphate causes cross-linking points to be too dense, molecular chain motion is restricted, and material brittleness increases. In Comparative Example 2, the amount of triphenyl phosphate is insufficient, and the introduction of insufficient phosphate groups can cause the antioxidant properties of the multi-coordinated triazine boron-phosphorus complex to decrease, and the free radical capture efficiency is reduced. At the same time, there are too few cross-linking points and the molecular chain is easy to slip.

[0070] As shown in Table 1, compared with Example 1, the rotary oxygen bomb time of Comparative Example 3 is reduced and the SSI is increased; the rotary oxygen bomb time of Comparative Example 4 is reduced and the SSI is increased. In Comparative Example 3, the amount of 1,2,3-triazole-4,5-dicarboxylic acid used is too much, and incompletely reacted triazole dicarboxylic acid remains, which may accelerate the oxidation reaction in a high temperature environment. The excess 1,2,3-triazole-4,5-dicarboxylic acid causes the thioester cross-linking network to be too dense. The high cross-linking density restricts the movement of molecular segments and increases the brittleness of the material. In Comparative Example 4, the amount of 1,2,3-triazole-4,5-dicarboxylic acid used is insufficient, resulting in fewer thioester cross-linking points, reduced free radical capture ability, and decreased antioxidant performance. The sparse cross-linking points make the molecular chain easy to slip, making the lubricating oil more susceptible to molecular chain breakage under high shear conditions.

[0071] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for preparing a reducer lubricating oil suitable for new energy vehicles, characterized in that: The preparation method comprises: S1, dispersing 2,4,6-trichloro-1,3,5-triazine, 4-hydroxyphenylboric acid, and sodium hydride in xylene to react to obtain product A, dispersing product A, o-phenanthroline, ferrous sulfate, and triethylamine in toluene, adding triphenyl phosphate, and reacting to obtain a multi-coordinated triazine boron-phosphorus complex; S2, in an ice-water bath, dispersing 2-amino-4,5-imidazole dicarbonitrile and n-butyl lithium solution in anhydrous tetrahydrofuran, adding phosphorus oxychloride to obtain pre-derivatized 2-amino-4,5-imidazole dicarbonitrile, mixing 1,2,3-triazole-4,5-dicarboxylic acid, methanol and concentrated sulfuric acid to react to produce dimethyl triazole dicarboxylate, which is then mixed with phosphorus pentasulfide to react to produce a thioester, dispersing the pre-derivatized 2-amino-4,5-imidazole dicarbonitrile, the thioester, boron trifluoride etherate and 4,4'-dithiodibenzoic acid in dimethylformamide to react to produce an nitrogen heterocycle-phosphorus sulfide polymer; S3, adding a multi-coordinated triazine boron-phosphorus complex, a nitrogen heterocycle-sulfur-phosphorus polymer, an antioxidant, a defoaming agent, and a rust inhibitor to a base oil, and mixing them evenly to obtain a reducer lubricant suitable for new energy vehicles.

2. The method for preparing a reducer lubricating oil suitable for new energy vehicles according to claim 1, characterized in that: In S1: The mass volume ratio of the 2,4,6-trichloro-1,3,5-triazine, 4-hydroxyphenylboric acid, sodium hydride and xylene is (50-60) g: (180-190) g: (12-15) g: 300 mL.

3. The method for preparing a reducer lubricating oil suitable for new energy vehicles according to claim 1, characterized in that: In S1: The mass volume ratio of the product A, o-phenanthroline, ferrous sulfate, triethylamine, toluene and triphenyl phosphate is (80-90) g: (6-10) g: (1-2) g: (4-5) g: 100 mL: (40-45) g.

4. The method for preparing a reducer lubricating oil suitable for new energy vehicles according to claim 1, characterized in that: In S2: The mass volume ratio of the 2-amino-4,5-imidazole dicarbonitrile, n-butyl lithium solution, tetrahydrofuran and phosphorus oxychloride is (30-40) g: (56-60) mL: 200 mL: (16-20) g.

5. The method for preparing a reducer lubricating oil suitable for new energy vehicles according to claim 1, characterized in that: In S2: The concentration of the n-butyllithium solution is 2.5 mol / L, and the solvent is n-hexane; The mass ratio of the 1,2,3-triazole-4,5-dicarboxylic acid, methanol and concentrated sulfuric acid is (10-15): (20-25): (1-2).

6. The method for preparing a reducer lubricating oil suitable for new energy vehicles according to claim 1, characterized in that: In S2: The mass ratio of the dimethyl triazoledicarboxylate to phosphorus pentasulfide is 10:(12-15).

7. The method for preparing a reducer lubricating oil suitable for new energy vehicles according to claim 1, characterized in that: In S2: The mass volume ratio of the pre-derivatized 2-amino-4,5-imidazole dicarbonitrile, thioester, boron trifluoride etherate, dimethylformamide and 4,4'-dithiodibenzoic acid is (30-35) g: (20-25) g: 2 g: 200 mL: (5-7) g.

8. The method for preparing a reducer lubricating oil suitable for new energy vehicles according to claim 1, characterized in that: In S3: The base oil is any one of mineral base oil, polyalphaolefin synthetic oil, and ester synthetic oil.

9. The method for preparing a reducer lubricating oil suitable for new energy vehicles according to claim 1, characterized in that: In S3: The mass ratio of the multi-coordinated triazine boron-phosphorus complex, the nitrogen heterocycle-sulfur-phosphorus polymer, the antioxidant, the defoaming agent, the rust inhibitor and the base oil is 7:5:1:1:1:

85.

10. A reducer lubricant suitable for new energy vehicles is obtained according to the preparation method according to any one of claims 1 to 9.

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