An anti-wear and anti-oxidation lubricating oil additive and its preparation method and application

Abstract

The present invention discloses an anti-wear and anti-oxidation lubricating oil additive, its preparation method, and its application. This invention relates to the field of lubricating materials technology and addresses the problem of unsatisfactory thermal oxidation stability of existing lubricating oil additives. The anti-wear and anti-oxidation lubricating oil additive comprises a compound represented by Formula I: #imgabs0#, where R is an alkali metal or alkaline earth metal. The additive provided by the present invention exhibits excellent thermal oxidation stability.

Description

Technical Field

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

[0002] The modern machinery industry has increasingly higher requirements for the high-temperature antioxidant properties of lubricants. Whether it is aerospace lubricants, engine lubricants or industrial lubricants, increasingly stringent requirements are placed on the high-performance antioxidants of lubricants. As lubrication conditions become more stringent, lubricants are required to have good high-temperature antioxidant properties.

[0003] At present, the antioxidants used in high-temperature lubricating oils are mainly aromatic amine antioxidants. Aromatic amine antioxidants can effectively control the changes in oil viscosity and acid value, increase the synergistic effect between various additives, and improve the efficiency of additive use.

[0004] However, aromatic amine antioxidants are easily oxidized and have a short induction period. Therefore, they still have certain limitations in improving the thermal oxidation stability of lubricating oils. Summary of the Invention

[0005] The present invention provides an anti-wear and anti-oxidation lubricating oil additive and a preparation method and application thereof, which are used to solve the problem that the thermal oxidation stability of lubricating oil additives in the prior art is not ideal.

[0006] In a first aspect, the present invention provides an anti-wear and antioxidant lubricating oil additive, wherein the lubricating oil additive comprises a compound represented by 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 anti-wear and antioxidant 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 2-mercaptobenzimidazole and boric acid 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 anti-wear and antioxidant 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 minutes; and / or, when the product I is reacted with a chelating agent, the reaction temperature is 80-150°C and the reaction time is 10-360 minutes; and / or, when the 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 minutes.

[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 2-mercaptobenzimidazole and boric acid are added for esterification reaction, the molar ratio of 2-mercaptobenzimidazole:boric acid and dodecylphenol is 1-5:2-10:1; and / or, when product II is subjected to a substitution reaction with an alkali metal salt / alkaline earth metal salt, 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 one or more 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 anti-wear and anti-oxidation lubricating oil additive described in the first aspect or the anti-wear and anti-oxidation lubricating oil additive prepared by the preparation method described in 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 0.7%.

[0018] The anti-wear and anti-oxidation lubricating oil additive provided by the present invention comprises an organic borate group, a benzimidazole group, and an aromatic amine group, and can dissociate into alkali metal / alkaline earth metal cations. Specifically, the anti-wear and anti-oxidation lubricating oil additive provided by the present invention replaces the hydroxyl group in the borate with an organic alcohol to form an organic borate. Modification of the borate surface to introduce nitrogen atoms further enhances the compound's hydrolytic stability. Furthermore, the organic borate group readily adsorbs on metal surfaces, enhancing the lubricating oil's anti-wear properties. The benzimidazole group can capture free radicals generated by oil oxidation and hydroperoxides generated by decomposition, improving the lubricating oil's antioxidant properties. The dissociated alkali metal / alkaline earth metal cations interact with the original aromatic amine group to reduce the aromatic amine's reactivity, creating a synergistic antioxidant effect. This increases the additive's induction period and improves its thermal oxidative stability. Furthermore, the alkali metal or alkaline earth metal salts exhibit excellent antioxidant stabilization not only in ester lubricating oils but also in other lubricating oils, such as hydrocarbons, polyphenylene ethers, perfluoroesters, and polyphenylene sulfides.

[0019] The anti-wear and anti-oxidation lubricating oil additive provided by the present invention has a boron element that can complex with the fluorine in the perfluoropolyether lubricating oil, thereby increasing the solubility of the additive in the perfluoropolyether lubricating oil and improving the effect efficiency of the additive. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] 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.

[0021] Figure 1 The infrared spectrum of potassium 2-mercaptobenzimidazole borate provided in an embodiment of the present invention.

[0022] 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.

[0023] Figure 3 This is a graph showing the anti-wear performance test results of Experiment V provided in an embodiment of the present invention, wherein the scale bar in A is 100 μm and the scale bar in B is 50 μm. DETAILED DESCRIPTION

[0024] The following will provide a clear and complete description of 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. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0025] In order to solve the problem of unsatisfactory thermal oxidation stability of lubricating oil additives in the prior art, this embodiment provides an anti-wear and anti-oxidation lubricating oil additive and a preparation method and application thereof.

[0026] The anti-wear and anti-oxidation lubricating oil additive provided by the present invention comprises an organic borate group, a benzimidazole group, and an aromatic amine group, and can dissociate into alkali metal / alkaline earth metal cations. Specifically, the anti-wear and anti-oxidation lubricating oil additive provided by the present invention replaces the hydroxyl group in the borate with an organic alcohol to form an organic borate. Modification of the borate surface to introduce nitrogen atoms further enhances the compound's hydrolytic stability. Furthermore, the organic borate group readily adsorbs on metal surfaces, enhancing the lubricating oil's anti-wear properties. The benzimidazole group can capture free radicals generated by oil oxidation and hydroperoxides generated by decomposition, improving the lubricating oil's antioxidant properties. The dissociated alkali metal / alkaline earth metal cations interact with the original aromatic amine group to reduce the aromatic amine's reactivity, creating a synergistic antioxidant effect. This increases the additive's induction period and improves its thermal oxidative stability. Furthermore, the alkali metal or alkaline earth metal salts exhibit excellent antioxidant stabilization not only in ester lubricating oils but also in other lubricating oils, such as hydrocarbons, polyphenylene ethers, perfluoroesters, and polyphenylene sulfides.

[0027] Furthermore, the examples of the present invention demonstrate that, compared with traditional additives, the lubricating oil additive provided by the present invention can improve the anti-wear and thermal oxidation stability of lubricating oil.

[0028] 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 lubricating oil.

[0029] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0030] 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 2-mercaptobenzimidazole solution used is ethanol, and the 2-mercaptobenzimidazole solution has a concentration of 50%.

[0031] Example 1

[0032] This example provides an experiment for preparing a lubricating oil additive.

[0033] 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 stirred at 60° C. for 20 min until 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 until the reaction was complete. 30 g of 2-mercaptobenzimidazole solution (chemically pure, Zhengzhou Keyulong Chemical Products Co., Ltd.), 0.1 mol of boric acid (chemically pure, Sinopharm Chemical Reagent Co., Ltd.), and 5 mL of water were added as solvent. The mixture was heated with stirring and the mixture was subjected to esterification reaction at 120° C. 27.7 g of potassium carbonate (chemically pure, Shandong Wanqing Chemical Co., Ltd.) was added, and the hydrogen ions were replaced at 60° C. The reaction was carried out for 10 min to obtain product A1.

[0034] 0.1 mol of dodecylphenol was added to a 250 mL three-necked flask, followed by 0.25 mol of dibutylamine, 45 g of formaldehyde solution, and 10 mL of toluene as a solvent. The mixture was stirred at 100°C for 6 hours until the reaction was complete. 55 g of zinc acetate was added, and a chelation reaction was carried out at 110°C for 3 hours until the reaction was complete. 75.1 g of 2-mercaptobenzimidazole solution, 0.6 mol of boric acid, and 10 mL of water were added as a solvent. The mixture was heated with stirring and an esterification reaction was carried out at 135°C. 83 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 A2.

[0035] 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. 150.2 g of 2-mercaptobenzimidazole solution, 1 mol of boric acid, and 20 mL of water were added as a solvent. The mixture was heated with stirring and an esterification reaction was carried out at 150°C. 138.2 g of potassium carbonate was added, and the hydrogen ions were replaced at 150°C. The reaction was carried out for 6 hours to obtain product A3.

[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 10 mL of toluene were added as a solvent. The mixture was stirred 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. 75.1 g of 2-mercaptobenzimidazole 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 B.

[0037] 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 stirred at 100°C for 6 hours until the reaction was complete. 55 g of zinc acetate was added, and a chelation reaction was carried out at 110°C for 3 hours until the reaction was complete. 75.1 g of 2-mercaptobenzimidazole 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. 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.

[0038] 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 stirred at 100°C for 6 hours until the reaction was complete. 55 g of zinc acetate was added, and a chelation reaction was carried out at 110°C for 3 hours until the reaction was complete. 75.1 g of 2-mercaptobenzimidazole 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. 72.3 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.

[0039] The infrared spectrum of the obtained product A2 is shown in Figure 1 ,from Figure 1 It can be seen that at 3201cm -1 There is an OH absorption peak at 2958 cm -1 The peak of CH stretching vibration is at 1378 cm -1 The borate ester BO absorption peak appears at 1263 cm -1 The elemental analysis results of the obtained product are shown in Table 1.

[0040] Table 1 Elemental analysis results of compounds

[0041]

[0042]

[0043] As can be seen from Table 1, the measured values ​​of the elemental analysis results of Products A1 to Product D are roughly consistent with the theoretical values. Combining the infrared spectra and elemental content analysis, it can be concluded that the synthesized Products A1 to Product D are all compounds represented by Formula I, wherein R in Products A1 to Product A3 is potassium.

[0044] Example 2

[0045] This example provides a performance test experiment for a lubricating oil additive.

[0046] Products A1 to D prepared in Example 1 were subjected to antioxidant and anti-wear performance test experiments. The results showed that adding products A1 to D as additives significantly improved the antioxidant and anti-wear properties of perfluoropolyether lubricants. This example used product A2 as an example for the experiment.

[0047] Perfluoropolyether lubricant was randomly divided into 10 parts, namely blank group, control group I, control group II and experimental groups I to VII, among which, the blank group did not add additives; dialkyl dithiophosphate zinc (chemically pure, Wuhan Jixin Yibang Biotechnology Co., Ltd.) was added at a dose of 0.5% in the control group I; N, N-di-sec-butyl-p-phenylenediamine (chemically pure, Tianjin CITIC Kaitai Chemical Co., Ltd.) was added at a dose of 0.5% in the control group II; the experimental groups I to VII were added with the product A2 prepared in Example 1 at doses of 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6% and 0.7%, respectively; as the test matrix for each group.

[0048] Oxidation stability tests were conducted on 10 groups of test substrates according to the SH / T0259-1992 lubricating oil thermal oxidation stability test method, and the results are shown in Table 2.

[0049] Table 2 Oxidation stability of different groups of lubricants

[0050]

[0051]

[0052] As shown in Table 2, the initial oxidation temperature of the perfluoropolyether lubricant is 293°C. This temperature increases rapidly with the addition of Product A2, and further increases with increasing additive content, demonstrating the additive's excellent antioxidant properties. Furthermore, the antioxidant properties of lubricants containing Product A2 prepared in Example 1 (Experimental Groups I to VII) are significantly superior to those containing conventional additives (Control Group II). When the addition level of Product A2 prepared in Example 1 is between 0.5% and 0.7%, the antioxidant properties are even better.

[0053] 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.

[0054] 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 balls in the experimental group V is smoother than that of the test balls in the blank group, indicating that the product A2 prepared in Example 1 can improve the anti-wear performance of perfluoropolyether lubricant as a lubricant additive.

[0055] Example 3

[0056] This example provides a compatibility test experiment between lubricating oil additives and lubricating oil.

[0057] Products A1 to D prepared in Example 1 were all subjected to compatibility tests. The results showed that Products A1 to D had better compatibility with perfluoropolyether lubricant as additives. This example used Product A2 as an example for the experiment.

[0058] The 9 groups of matrices prepared in Example 2, except the control group, 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 three test matrices were taken respectively. The content of zinc dialkyl dithiophosphate in the oil sample of control group I was determined by infrared spectroscopy; the content of N,N-di-sec-butyl-p-phenylenediamine in the oil sample of control group II was determined by high performance liquid chromatography; and the content of the compound represented by formula I in the oil samples of experimental groups I to VII was determined by Raman spectroscopy. The test results are shown in Table 3.

[0059] Table 3 Additive content

[0060]

[0061] As shown in Table 3, both Control Groups I and II showed obvious stratification, with the additive located in the upper layer of the lubricant. Experimental Groups I to VII showed no stratification, indicating that Product A2 with different addition amounts had good compatibility with the lubricant.

[0062] 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.

[0063] 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. An anti-wear and anti-oxidation 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 anti-wear and antioxidant 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, 2-mercaptobenzimidazole and boric acid 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 anti-wear and anti-oxidation 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 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 product II undergoes 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 2-mercaptobenzimidazole and boric acid are added for esterification reaction, the molar ratio of the 2-mercaptobenzimidazole: the boric acid and the dodecylphenol is 1-5:2-10:1; And / or, when the product II is subjected to a substitution reaction with an alkali metal salt / alkaline earth metal salt, 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 one or more 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 anti-wear and anti-oxidation lubricating oil additive according to claim 1 or the anti-wear and anti-oxidation 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 0.7%.

Images