Lubricating oil additive and its preparation method and application

Abstract

The present invention discloses a lubricant additive, its preparation method, and its application. These materials fall within the technical field of lubricating materials and address the existing problem of poor compatibility between lubricant additives and lubricating oils. The lubricant additive comprises a compound represented by Formula I: #imgabs0#, where R is H or an alkali metal. The boron element in the lubricant additive can complex with the fluorine element in the lubricant, increasing its solubility in the lubricant.

Description

Technical Field

[0001] The present invention relates to the technical field of lubricating materials, and more particularly to a lubricating oil additive and a preparation method and application thereof. Background Art

[0002] Lubricating oil is the lifeblood of an engine, and its performance and quality are directly linked to the proper functioning of the engine system and the safe operation of the machine. With the advancement of industrial technology, aircraft are flying at ever-higher speeds and longer ranges, leading to ever-increasing temperatures in engine bearing chambers. Consequently, the demand for oxidative stability in engine lubricants is increasing. If lubricating oil has poor oxidative stability, prolonged use at high temperatures can easily lead to oxidation and polymerization, forming large coke particles. These coke particles can clog filters, increase wear on precision oil regulating components, and cause seal leakage, disrupting the proper oil supply to the engine and mechanical components, and in severe cases, jeopardizing flight safety. Therefore, antioxidants and anti-wear agents are crucial additives in lubricating oils.

[0003] At present, perfluoropolyether lubricants have been used as aircraft instrument bearing lubricants, special grease base oils, mechanical sealing fluids, rocket nozzle lubricants, and vacuum pump lubricants due to their excellent chemical inertness, thermal stability, non-flammability and low saturated vapor pressure.

[0004] However, perfluoropolyether lubricants are mostly non-polar compounds, while existing antioxidants and anti-wear agents are mostly polar additives. The compatibility between the two is poor. Long-term standing will cause stratification of the base oil and additives, reducing the overall performance of the lubricant. Summary of the Invention

[0005] The present invention provides a lubricating oil additive and a preparation method and application thereof, which are used to solve the problem of poor compatibility between existing additives and lubricating oil.

[0006] In a first aspect, the present invention provides a lubricating oil additive having a structural formula as shown in Formula I:

[0007]

[0008] In formula I, R is any one of an alkali metal or an alkaline earth metal.

[0009] In a second aspect, the present invention provides a method for preparing the lubricating oil additive described in the first aspect, comprising the following steps: reacting dodecylphenol, dibutylamine and formaldehyde in a solvent system to obtain an intermediate product I; reacting the intermediate product I with a chelating agent, and then adding benzotriazole, boric acid and ethanol to carry out an esterification reaction to obtain an intermediate product II; and allowing the intermediate product II to undergo a substitution reaction with an alkali metal salt / alkaline earth metal salt to obtain the lubricating oil additive.

[0010] As a possible implementation method, when dodecylphenol, dibutylamine and formaldehyde are reacted in a solvent system, the reaction temperature is 60-150°C and the reaction time is 20-720 min; and / or, when the intermediate product I is reacted with a chelating agent, the reaction temperature is 80-150°C and the reaction time is 10-360 min; and / or, when the intermediate product II is subjected to a substitution reaction with an alkali metal salt / alkaline earth metal salt, the reaction temperature is 60-150°C and the reaction time is 10-360 min.

[0011] As a possible implementation manner, when dodecylphenol, dibutylamine and formaldehyde are reacted in a solvent system, the molar ratio of dodecylphenol:dibutylamine:formaldehyde is 1:1-5:2-10; and / or, when benzotriazole, boric acid and ethanol are added for esterification reaction, the molar ratio of benzotriazole:boric acid:ethanol and dodecylphenol is 1-5:2-10:1-5:1; and / or, when the intermediate product I is reacted with a chelating agent, the molar ratio of the alkali metal salt / alkaline earth metal salt and dodecylphenol is 2-10:1.

[0012] As a possible implementation, the chelating agent is zinc acetate; and / or the alkali metal salt is any one of sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, sodium sulfate, sodium bisulfate, sodium chloride, and potassium chloride; and the alkaline earth metal salt is any one of calcium carbonate, magnesium sulfate, and magnesium chloride.

[0013] In a third aspect, the present invention provides a lubricating oil comprising the lubricating oil additive described in the first aspect or the lubricating oil additive prepared by any possible implementation method of the second aspect, and a base oil.

[0014] As a possible implementation, the base oil is one of perfluoropolyether lubricating oil, hydrocarbon lubricating oil, polyphenylene ether lubricating oil, perfluoroester lubricating oil, and polyphenylene sulfide lubricating oil.

[0015] As a possible implementation, the base oil is perfluoropolyether lubricating oil.

[0016] As a possible implementation manner, the mass percentage of the lubricating oil additive in the lubricating oil is 0.1% to 1.0%.

[0017] As a possible implementation manner, the mass percentage of the lubricating oil additive in the lubricating oil is 0.5% to 0.8%.

[0018] The lubricating oil additive provided by the present invention has an organic borate group, a benzotriazole group and an aromatic amine group, and can dissociate into alkali metal / alkaline earth metal cations. Among them, the boron element of the organic borate group in the lubricating oil additive provided by the present invention can be complexed with the fluorine element in the lubricating oil, thereby improving the solubility of the additive in the lubricating oil; and the group modifies the surface of the borate to introduce nitrogen atoms, which can further improve the hydrolysis stability of the compound; and the organic borate group is easily adsorbed on the metal surface, which can increase the anti-wear performance of the lubricating oil. The benzotriazole group in the lubricating oil additive provided by the present invention can capture free radicals generated by the oxidation of the oil and hydroperoxides generated by the decomposition, effectively improving the antioxidant performance of the lubricating oil and extending the service life of the lubricating oil. The dissociated alkali metal / alkaline earth metal cations react with the original aromatic amine groups to reduce the reactivity of aromatic amines, resulting in a synergistic antioxidant effect, thereby increasing the induction period of the additive and improving its thermal oxidation stability. Moreover, alkali metal salts or alkaline earth metal salts not only perform well in ester lubricants, but also exhibit good antioxidant stability in other oils, such as hydrocarbons, polyphenylene ethers, perfluoroesters, and polyphenylene sulfide lubricants. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 This is the infrared spectrum of the lubricating oil additive provided by an embodiment of the present invention.

[0021] Figure 2 This is a graph showing the anti-wear performance test results of the blank group provided in an embodiment of the present invention.

[0022] Figure 3 This is a graph showing the anti-wear performance test results of Experiment V group provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0023] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0024] In order to solve the problem of poor compatibility between existing additives and lubricating oil, this embodiment provides a lubricating oil additive and a preparation method and application thereof.

[0025] The lubricating oil additive provided by the present invention has a boron element that can complex with the fluorine element in the lubricating oil, thereby increasing the solubility of the additive in the lubricating oil. The examples of the present invention demonstrate that the lubricating oil additive provided by the present invention effectively improves its compatibility with the lubricating oil.

[0026] Furthermore, the examples of the present invention demonstrate that, compared with traditional additives, the lubricating oil additive provided by the present invention has better compatibility with perfluoropolyether lubricating oil; accordingly, it is verified that it has better performance in improving the antioxidant and anti-wear properties of lubricating oil.

[0027] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0028] The formaldehyde solution (ρ=1.083 g / mL) used in the embodiment of the present invention has a formaldehyde concentration of 40%. The solvent of the benzotriazole solution used is ethanol, and the volume fraction of the benzotriazole solution is 50%.

[0029] Example 1

[0030] This example provides an experiment for preparing a lubricating oil additive.

[0031] 0.1 mol of dodecylphenol (chemically pure, Aladdin Reagent (Shanghai) Co., Ltd.) was added to a 250 mL three-necked flask, and 0.1 mol of dibutylamine (chemically pure, Aladdin Reagent (Shanghai) Co., Ltd.), 15 g of formaldehyde solution (chemically pure, Sinopharm Chemical Reagent Co., Ltd.), and 5 mL of toluene (chemically pure, Sinopharm Chemical Reagent Co., Ltd.) were added as solvent. The mixture was mixed and reacted at 60°C for 20 min, and the reaction was complete. 25 g of zinc acetate (chemically pure, Aladdin Reagent (Shanghai) Co., Ltd.) was added, and the chelation reaction was carried out at 80°C for 10 min, and the reaction was complete. 17.7 mL of benzotriazole solution (chemically pure, Sinopharm Chemical Reagent Co., Ltd.), 0.1 mol of boric acid (chemically pure, Sinopharm Chemical Reagent Co., Ltd.), and 5 mL of water were added as solvent, heated with stirring, and esterification reaction was carried out at 120°C. 21.2 g of sodium carbonate (chemically pure, Shandong Wanqing Chemical Co., Ltd.) was added, and the hydrogen ions were replaced at 60°C. The reaction was reacted for 10 min to obtain product A1.

[0032] 0.1 mol of dodecylphenol was added to a 250 mL three-necked flask, and 0.25 mol of dibutylamine, 45 g of formaldehyde solution, and 10 mL of toluene were added as a solvent. The mixture was mixed and reacted at 100°C for 6 hours until the reaction was complete. 55 g of zinc acetate was added and the chelation reaction was carried out at 110°C for 3 hours until the reaction was complete. 44.2 mL of benzotriazole solution, 0.6 mol of boric acid, and 10 mL of water were added as a solvent. The mixture was heated and stirred, and an esterification reaction was carried out at 135°C. 63.6 g of sodium carbonate was added and the hydrogen ions were replaced at 100°C. The reaction was carried out for 3 hours to obtain product A2.

[0033] 0.1 mol of dodecylphenol was added to a 250 mL three-necked flask, followed by 0.5 mol of dibutylamine, 75 g of formaldehyde solution, and 15 mL of toluene as a solvent. The mixture was mixed and reacted at 150°C for 12 hours until the reaction was complete. 110 g of zinc acetate was added, and a chelation reaction was carried out at 150°C for 6 hours until the reaction was complete. 110.4 mL of benzotriazole solution, 1 mol of boric acid, and 20 mL of water were added as a solvent. The mixture was heated and stirred, and an esterification reaction was carried out at 150°C. 106 g of sodium carbonate was added, and the hydrogen ions were replaced at 150°C. The reaction was carried out for 6 hours to obtain product A3.

[0034] 0.1 mol of dodecylphenol was added to a 250 mL three-necked flask, and 0.25 mol of dibutylamine, 45 g of formaldehyde solution, and 7.5 mL of toluene were added as solvent. The mixture was mixed and reacted at 100°C for 6 hours until the reaction was complete. 55 g of zinc acetate was added and the chelation reaction was carried out at 110°C for 3 hours until the reaction was complete. 44.2 mL of benzotriazole solution, 0.6 mol of boric acid, and 7.5 mL of water were added as solvent. The mixture was heated and stirred, and the esterification reaction was carried out at 135°C. 82.9 g of potassium carbonate was added and the hydrogen ions were replaced at 100°C. The reaction was carried out for 3 hours to obtain product B.

[0035] 0.1 mol of dodecylphenol was added to a 250 mL three-necked flask, and 0.25 mol of dibutylamine, 45 g of formaldehyde solution, and 7.5 mL of toluene were added as a solvent. The mixture was mixed and reacted at 100°C for 6 hours until the reaction was complete. 55 g of zinc acetate was added and the chelation reaction was carried out at 110°C for 3 hours until the reaction was complete. 44.2 mL of benzotriazole solution, 0.6 mol of boric acid, and 7.5 mL of water were added as a solvent. The mixture was heated and stirred, and the esterification reaction was carried out at 135°C. 60 g of calcium carbonate was added and the hydrogen ions were replaced at 100°C. The reaction was carried out for 3 hours to obtain product C.

[0036] 0.1 mol of dodecylphenol was added to a 250 mL three-necked flask, and 0.25 mol of dibutylamine, 45 g of formaldehyde solution, and 7.5 mL of toluene were added as a solvent. The mixture was mixed and reacted at 100°C for 6 hours until the reaction was complete. 55 g of zinc acetate was added and the chelation reaction was carried out at 110°C for 3 hours until the reaction was complete. 44.2 mL of benzotriazole solution, 0.6 mol of boric acid, and 7.5 mL of water were added as a solvent. The mixture was heated and stirred, and the esterification reaction was carried out at 135°C. 72 g of magnesium sulfate was added and the hydrogen ions were replaced at 100°C. The reaction was carried out for 3 hours to obtain product D.

[0037] The infrared spectrum of the obtained product A2 is shown in Figure 1 ,from Figure 1 It can be seen that at 3325cm -1 There is an OH stretching vibration absorption peak at 3000~2800cm -1 The absorption peak at 1309cm is the C-H bond stretching vibration peak. -1 The borate ester BO stretching vibration absorption peak appears at 1020 cm -1 The elemental analysis results of the obtained product are shown in Table 1.

[0038] Table 1 Elemental analysis results of compounds

[0039]

[0040] As shown in Table 1, the measured values ​​of the elemental analysis results for Products A1 to D are generally consistent with the theoretical values. Combining the infrared spectra and elemental content analysis, it can be concluded that the synthesized Products A1 to D are all compounds represented by Formula I, where R in Products A1 to A3 is sodium.

[0041] Example 2

[0042] This example provides a compatibility test experiment of lubricating oil additives and perfluoropolyether lubricating oil.

[0043] Compatibility tests were conducted on products A1 to D prepared in Example 1. The results showed that products A1 to D had better compatibility with perfluoropolyether lubricants as additives. This example used product A2 as an example for experiments.

[0044] Perfluoropolyether lubricant (M03, DuPont China Group Co., Ltd.) was randomly divided into 10 equal parts, namely a blank group, a control group, and experimental groups I to VIII. Among them, the blank group did not add any additives; the control group added a commercial additive 2,4-dimethyl-6-phenylenediphenol at a dose of 0.5%, and experimental groups I to VIII added the product A2 prepared in Example 1 at doses of 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7% and 0.8%, respectively; as the test matrix for each group.

[0045] The test matrices of the control group and experimental groups I to VIII were ultrasonically treated at 120 kHz for 0.5 h, stirred for 0.5 h, and allowed to stand for 24 h. Samples of the upper 10% (upper part), the middle 10% (middle part), and the lower 10% (lower part) of the height of the test matrices of the three groups were taken respectively. The content of 2,4-dimethyl-6-phenylenediol in the control oil sample was determined by acid-base titration; the content of product A2 in the oil samples of experimental groups I to VIII was determined by HG / T5.1519-85 ultraviolet spectrophotometry. The test results are shown in Table 2.

[0046] Table 2 Additive content

[0047]

[0048] As shown in Table 2, the control group showed obvious stratification, with the additive located in the upper layer of the lubricant. Groups I to VIII showed no stratification, indicating that product A2, with varying addition amounts, exhibited good compatibility with the perfluoropolyether lubricant.

[0049] Example 3

[0050] This example provides a performance test experiment for a lubricating oil additive.

[0051] Performance testing experiments were conducted on products A1 to D prepared in Example 1. The results showed that adding products A1 to D as additives significantly improved the anti-wear and antioxidant properties of perfluoropolyether lubricants. This example used product A2 as an example for the experiment.

[0052] According to the NB / SH / T 0189-2017 standard, the blank group test matrix prepared in Example 2 and the test matrix of Experiment V were respectively subjected to the four-ball method lubricant anti-wear performance test, and the applied load was 392N. Figure 2 The SEM images of the blank test balls shown in FIG. Figure 3 The SEM image of the surface of the test ball of Experimental Group V is shown.

[0053] Depend on Figure 2 It can be seen that the blank group test ball has obvious scratches and furrows on its wear surface. The reason for the furrow wear is the abrasive wear. Figure 3 It can be seen that the surface of the test ball in Experimental Group V is smoother than that in the blank group, indicating that the product A2 prepared in Example 1 can improve the anti-wear performance of perfluoropolyether lubricant as an additive.

[0054] According to the SH / T0259-1992 lubricating oil thermal oxidation stability test method, thermal oxidation experiments were performed on the 10 groups of matrices prepared in Example 2, and the results shown in Table 3 were obtained.

[0055] Table 3 Oxidation stability of different groups of lubricants

[0056] Initial oxidation temperature (℃) ΔT(℃) Blank group 293 control group 303 10 Experimental Group I 342 49 Experimental Group II 355 62 Experimental group III 371 78 Experimental Group IV 383 90 Experimental Group V 387 94 Experimental Group VI 397 104 Experimental Group VII 397 104 Experimental Group VIII 397 104

[0057] As shown in Table 3, the initial oxidation temperature of the perfluoropolyether lubricant is 293°C. This temperature increases rapidly with the addition of Product A2 prepared in Example 1, and further increases with increasing additive content, indicating that the additive has excellent antioxidant properties. When the addition level of Product A2 prepared in Example 1 is 0.5% or greater, the antioxidant properties are even better.

[0058] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0059] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A lubricating oil additive, characterized in that: Containing the compound shown in formula I: In formula I, R is any one of an alkali metal or an alkaline earth metal.

2. A method for preparing the lubricating oil additive according to claim 1, characterized in that: The following steps are involved: Dodecylphenol, dibutylamine and formaldehyde react in a solvent system to obtain intermediate product I; After reacting the intermediate product I with a chelating agent, benzotriazole, boric acid and ethanol are added to carry out an esterification reaction to obtain an intermediate product II; The intermediate product II is subjected to a substitution reaction with an alkali metal salt / alkaline earth metal salt to obtain the lubricating oil additive.

3. The preparation method according to claim 2, characterized in that When the dodecylphenol, dibutylamine and formaldehyde are reacted in a solvent system, the reaction temperature is 60 to 150° C. and the reaction time is 20 to 720 minutes; and / or, when the intermediate product I is reacted with a chelating agent, the reaction temperature is 80 to 150° C. and the reaction time is 10 to 360 minutes; And / or, when the intermediate product II is subjected to a substitution reaction with an alkali metal salt / alkaline earth metal salt, the reaction temperature is 60-150° C. and the reaction time is 10-360 min.

4. The preparation method according to claim 2, characterized in that When the dodecylphenol, dibutylamine and formaldehyde are reacted in a solvent system, the molar ratio of the dodecylphenol: the dibutylamine: the formaldehyde is 1:1-5:2-10; And / or, when benzotriazole, boric acid and ethanol are added for esterification reaction, the molar ratio of the benzotriazole: the boric acid: the ethanol and the dodecylphenol is 1-5:2-10:1-5:1; And / or, when the intermediate product I is reacted with a chelating agent, the molar ratio of the alkali metal salt / alkaline earth metal salt to the dodecylphenol is 2 to 10:

1.

5. The preparation method according to claim 2, characterized in that The chelating agent is zinc acetate; And / or, the alkali metal salt is any one of sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, sodium sulfate, sodium bisulfate, sodium chloride, and potassium chloride; and the alkaline earth metal salt is any one of calcium carbonate, magnesium sulfate, and magnesium chloride.

6. A lubricating oil, characterized in that: The invention comprises a lubricating oil additive and a base oil, wherein the lubricating oil additive is the lubricating oil additive according to claim 1 or the lubricating oil additive prepared by the preparation method according to any one of claims 2 to 5.

7. The lubricating oil according to claim 6, characterized in that The base oil is one of perfluoropolyether lubricating oil, hydrocarbon lubricating oil, polyphenylene ether lubricating oil, perfluoroester lubricating oil and polyphenylene sulfide lubricating oil.

8. The lubricating oil according to claim 6, characterized in that The base oil is perfluoropolyether lubricating oil.

9. The lubricating oil according to claim 6, characterized in that The mass percentage of the lubricating oil additive in the lubricating oil is 0.1% to 1.0%.

10. The lubricating oil according to claim 6, characterized in that The mass percentage of the lubricating oil additive in the lubricating oil is 0.5% to 0.8%.

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