Environment-friendly bearing anti-rust oil and preparation method thereof

Abstract

The invention discloses environment-friendly bearing anti-rust oil and a preparation method thereof, and relates to the technical field of metal protection, the environment-friendly bearing anti-rust oil comprises the following raw materials by weight: 45-55 parts of base oil, 4-6 parts of a film-forming agent, 3-7 parts of an anti-rust agent, 0.6-1 part of an antioxidant, 1.5-2.5 parts of an auxiliary agent, 1-2 parts of a surfactant, and 0.2-0.4 part of a pour point depressant; the base oil is castor oil-based base oil; the auxiliary agent is a novel composite material of L-tryptophan, chitosan and hollow mesoporous nano silicon dioxide; the novel L-tryptophan-chitosan-hollow mesoporous nano silicon dioxide composite material is prepared from the following raw materials in parts by weight: 2 to 3 parts of KH570 modified hollow mesoporous nano silicon dioxide, 200 to 300 parts of deionized water and 2 to 3 parts of an L-tryptophan-chitosan derivative. The cutting fluid has excellent anti-rust property, environmental protection property and oxidation stability.

Description

Technical Field

[0001] This application relates to the field of metal protection technology, and in particular to an environmentally friendly bearing rust-preventive oil and its preparation method. Background Technology

[0002] Bearings are typically divided into bearing rings, rolling elements, and cages, which are usually manufactured by different companies. Bearing rings and rolling elements require rust prevention treatment during processing, storage, and transportation to prevent corrosion. The commonly used material for rust prevention is rust-preventive oil, which is a temporary rust-preventive agent. Most rust-preventive oils consist of base oil and rust-inhibiting additives. Traditional rust-preventive oils mostly use petroleum-based mineral oils as base oils, whose non-renewable nature exacerbates resource depletion, and their difficulty in biodegradation after use easily leads to soil / water pollution. Furthermore, with technological advancements, current petroleum-based mineral oils can no longer fully meet production technology requirements. Therefore, for the sustainable development of the country and society, it is essential to develop a type of green and renewable lubricant to replace traditional petroleum-based mineral oils as soon as possible. Vegetable oils, as a type of natural lubricant, have many advantages: such as high viscosity index, low volatility, high flash point, excellent frictional performance, and large modification potential. Most importantly, vegetable oils are a green and renewable resource. Therefore, base oils prepared from vegetable oils can perfectly solve the major crises faced by traditional petroleum-based mineral oils.

[0003] However, existing vegetable oil-based rust inhibitors are poor in terms of oxidation stability and rust prevention, making it difficult to meet the requirements for long-term storage of bearings. Summary of the Invention

[0004] In order to improve the rust prevention performance and oxidation stability of vegetable oil-based rust inhibitors, this application provides an environmentally friendly bearing rust inhibitor and its preparation method.

[0005] This application provides an environmentally friendly bearing rust-preventive oil, which adopts the following technical solution: An environmentally friendly bearing rust-preventive oil comprises, by weight, 45-55 parts base oil, 4-6 parts film-forming agent, 3-7 parts rust inhibitor, 0.6-1 part antioxidant, 1.5-2.5 parts additives, 1-2 parts surfactant, and 0.2-0.4 parts pour point depressant; the base oil is castor oil-based base oil; and the additives are a novel composite material of L-tryptophan-chitosan-hollow mesoporous nano-silica.

[0006] Preferably, the novel L-tryptophan-chitosan-hollow mesoporous nano-silica composite material is prepared from the following raw materials in parts by weight: 2-3 parts KH570 modified hollow mesoporous nano-silica, 200-300 parts deionized water, and 2-3 parts L-tryptophan-chitosan derivative.

[0007] Preferably, the method for preparing the castor oil-based base oil includes the following steps: S1. Add ricinoleic acid, organic solvent, catalyst Novozyme 435, and hydrogen peroxide to castor oil. Then, shake the reaction in a water bath at 40-50℃ and 200-250 rpm for 15-22 hours. After that, take out the sample, remove the catalyst from the reaction solution by vacuum filtration, let it stand to separate the layers, remove the hydrogen peroxide from the lower layer, and then centrifuge the upper oil layer at high speed to remove any remaining catalyst and hydrogen peroxide. Then, wash with sodium bicarbonate solution and distilled water to remove the water layer. Centrifuge the upper oil layer to remove water, and finally remove the organic solvent and residual water by vacuum rotary evaporation to obtain the primary castor oil base oil. S2. Add isooctanol to the primary castor oil-based base oil obtained in S1, preheat, and purge with nitrogen. When the temperature of the reaction system reaches 70-80℃, add concentrated sulfuric acid dropwise, then raise the temperature to 100-110℃ and react for 12-24 hours to complete the ring-opening reaction. Wash the completely reacted solution with sodium bicarbonate solution and distilled water, collect the upper oil layer, and remove water and organic alcohol solvent by vacuum distillation to obtain the ring-opening modified primary castor oil-based base oil. S3. Add hexanoic anhydride and catalyst 4-dimethylaminopyridine to the ring-opening modified primary castor oil base oil obtained in S2, purge with nitrogen, heat to 75-85℃, and react for 20-28 hours. Then add distilled water to the flask and continue the reaction for 1-3 hours to convert the organic acid anhydride into an organic acid. Then wash the reaction solution with sodium bicarbonate solution and water, collect the upper oil layer, and remove the water by vacuum distillation to obtain the castor oil base oil.

[0008] Preferably, the mass ratio of castor oil, organic solvent, catalyst Novozyme 435, ricinoleic acid, and hydrogen peroxide in S1 is 1:0.95-1:0.1-0.12:0.16-0.2:0.2-0.22.

[0009] Preferably, the mass ratio of isooctanol and concentrated sulfuric acid in the primary castor oil base oil in S2 is 1:2.8-3:0.006-0.0065.

[0010] Preferably, the mass ratio of the ring-opening modified primary castor oil base oil, hexanoic anhydride, and catalyst 4-dimethylaminopyridine in S3 is 1:1-1.2:0.0003-0.0005.

[0011] Preferably, the preparation method of the novel L-tryptophan-chitosan-hollow mesoporous nano-silica composite material includes the following steps: Add 2-3 parts of KH570 modified hollow mesoporous nano silica to 200-300 parts of deionized water and treat with ultrasound for 1-2 hours to disperse it evenly in the system; then add 2-3 parts of L-tryptophan-chitosan derivative and stir to dissolve, and magnetically stir at 50-60℃ for 3-5 hours; after the reaction, centrifuge the mixed solution, take the supernatant and dry it at 60-70℃ for 65-80 hours to obtain the novel L-tryptophan-chitosan-hollow mesoporous nano silica composite material.

[0012] Preferably, the preparation method of the L-tryptophan-chitosan derivative includes the following steps: By weight, 2-3 parts of chitosan powder were added to 120-160 parts of a 1% acetic acid solution, and the mixture was stirred continuously until the chitosan powder was completely dissolved to obtain a chitosan solution. 5.64-8.46 parts of L-tryptophan were added to 60-90 parts of ethanol and dissolved by ultrasonic heating to obtain an L-tryptophan solution. The chitosan solution and L-tryptophan solution were then mixed and magnetically stirred at 60-70℃ for 5-7 hours. After the reaction was completed, the mixture was cooled to room temperature. Sodium hydroxide solution was added to precipitate the product, which was then filtered. The precipitate was washed successively with deionized water and ethanol to remove impurities. Finally, the washed product was dried at 60-70℃ for 20-28 hours to obtain the L-tryptophan-chitosan derivative.

[0013] Preferably, the preparation method of the KH570 modified hollow mesoporous nano-silica includes the following steps: By weight, 0.08-0.12 parts of silane coupling agent KH570 were added to 0.8-1.2 parts of water and 7-10.6 parts of anhydrous ethanol, stirred and dissolved to obtain a silane coupling agent solution. The solution was then mechanically stirred and dispersed for 10-30 minutes. The pH was adjusted to 3-4, and 2-3 parts of hollow mesoporous nano-silica were added. After mixing evenly, the solution was dispersed in an ultrasonic water bath for 30-50 minutes. The temperature was then raised to 70-80℃ and refluxed under nitrogen protection for 10-14 hours. After the reaction was completed, the solution was vacuum filtered. The obtained sample was dried to obtain KH570 modified hollow mesoporous nano-silica.

[0014] Preferably, the rust inhibitor is composed of calcium petroleum sulfonate, zinc naphthenate, and benzotriazole in a mass ratio of 2-3:1-2:0.1-0.3.

[0015] Preferably, the film-forming agent is butyl paraffin oxide.

[0016] Preferably, the antioxidant is Vanlube 7723.

[0017] This application provides a method for preparing an environmentally friendly bearing rust-preventive oil, which adopts the following technical solution: A method for preparing an environmentally friendly bearing rust-preventive oil includes the following steps: Heat and stir 45-55 parts of base oil at 50-60℃, then add 4-6 parts of film-forming agent, 3-7 parts of rust inhibitor, 0.6-1 part of antioxidant, 1.5-2.5 parts of additives, 1-2 parts of surfactant, and 0.2-0.4 parts of pour point depressant in sequence. Stir at a constant temperature of 50-60℃ for 2-4 hours. After filtration through a 5μm bag, the environmentally friendly bearing rust-preventive oil is obtained.

[0018] In summary, this application includes at least one of the following beneficial technical effects: 1. This application uses epoxidized castor oil synthesized by bio-enzymatic method as raw material, and employs isooctyl alcohol and hexanoic anhydride to perform ring-opening modification and acylation modification on the epoxidized castor oil to develop a castor oil-based base oil with excellent low-temperature performance. Castor oil is a renewable resource, and its replacement of traditional mineral oil complies with green and environmentally friendly industry policies. Furthermore, the ring-opening reaction reduces the tendency of fatty acid crystallization, and combined with pour point depressants, ensures good fluidity even at low temperatures, facilitating bearing coating. Acylation modification reduces unsaturated double bonds, and combined with the synergistic effect of antioxidant Vanlube 7723, it delays the oxidative degradation of the oil and extends its service life.

[0019] 2. This application uses chitosan, L-tryptophan, and KH570-modified hollow mesoporous nano-silica as raw materials to prepare an L-tryptophan-chitosan derivative. This derivative is then hybridized with KH570-modified hollow mesoporous nano-silica to prepare a novel L-tryptophan-chitosan-hollow mesoporous nano-silica composite material. This material not only exhibits excellent corrosion inhibition, but the modification with KH570 enhances its compatibility with castor oil-based base oils, solving the problem of nanomaterial agglomeration. The amino groups of chitosan form coordination bonds with the metal surface, generating a dense protective film. The indole groups of L-tryptophan provide additional electrons, enhancing film stability. Combined with a composite rust inhibitor, this significantly improves the rust-preventive performance and storage stability of the rust-preventive oil. Detailed Implementation

[0020] The present application will be further described in detail below with reference to the embodiments.

[0021] The chemical reagents used in the preparation examples, embodiments, and comparative examples provided in this invention are all commercially available products.

[0022] Preparation Example 1: Preparation of Castor Oil-Based Base Oil Preparation Example 1.1 S1. Add 16g ricinoleic acid, 95g toluene, 10g catalyst Novozyme 435, and 20g hydrogen peroxide to 100g castor oil. Then, shake the reaction in a water bath at 40℃ and 200rpm for 15 hours. After that, take out the sample, remove the catalyst from the reaction solution by vacuum filtration, let it stand to separate the layers, remove the hydrogen peroxide from the lower layer, and then centrifuge the upper oil layer at high speed to remove any remaining catalyst and hydrogen peroxide. Then wash with a 2% sodium bicarbonate solution, followed by washing with distilled water until neutral to remove the water layer. Centrifuge the upper oil layer to remove water, and finally remove the organic solvent and residual water by rotary evaporation under reduced pressure to obtain the primary castor oil base oil. S2. Add 280g of isooctanol to 100g of primary castor oil-based base oil obtained from S1, preheat, and purge with nitrogen. When the temperature of the reaction system reaches 70℃, add 0.6g of 98% concentrated sulfuric acid dropwise, then raise the temperature to 100℃ and react for 12h to complete the ring-opening reaction. Wash the completely reacted solution with a 2% sodium bicarbonate solution, then wash with distilled water until neutral, collect the upper oil layer, and remove water and organic alcohol solvent by vacuum distillation to obtain the ring-opening modified primary castor oil-based base oil. S3. Add 100g of hexanoic anhydride and 0.03g of catalyst 4-dimethylaminopyridine to 100g of the ring-opening modified primary castor oil base oil obtained from S2, purge with nitrogen, heat to 75℃, and react for 20h. Then add 100g of distilled water to the flask and continue the reaction for 1h to convert the organic acid anhydride into an organic acid. Then wash the reaction solution with a 10% sodium bicarbonate solution, and then wash the product with distilled water until neutral. Collect the upper oil layer, remove water by vacuum distillation, and obtain the castor oil base oil.

[0023] Preparation Example 1.2 S1. Add 18g ricinoleic acid, 98g toluene, 11g catalyst Novozyme 435, and 21g hydrogen peroxide to 100g castor oil. Then, shake the reaction in a water bath at 45℃ and 225rpm for 19 hours. After 19 hours, take out the sample, remove the catalyst from the reaction solution by vacuum filtration, let it stand to separate the layers, remove the hydrogen peroxide from the lower layer, and then centrifuge the upper oil layer at high speed to remove any remaining catalyst and hydrogen peroxide. Then wash with a 2% sodium bicarbonate solution, followed by washing with distilled water until neutral to remove the water layer. Centrifuge the upper oil layer to remove water, and finally remove the organic solvent and residual water by rotary evaporation under reduced pressure to obtain primary castor oil-based base oil. S2. Add 290g of isooctanol to 100g of primary castor oil-based base oil obtained from S1, preheat, and purge with nitrogen. When the temperature of the reaction system reaches 75℃, add 0.625g of 98% concentrated sulfuric acid dropwise, then raise the temperature to 105℃ and react for 18h to complete the ring-opening reaction. Wash the completely reacted solution with a 2% sodium bicarbonate solution, then wash with distilled water until neutral, collect the upper oil layer, and remove water and organic alcohol solvent by vacuum distillation to obtain the ring-opening modified primary castor oil-based base oil. S3. Add 110g of hexanoic anhydride and 0.04g of catalyst 4-dimethylaminopyridine to 100g of the ring-opening modified primary castor oil base oil obtained from S2, purge with nitrogen, heat to 80℃, and react for 24h. Then add 110g of distilled water to the flask and continue the reaction for 2h to convert the organic acid anhydride into an organic acid. Then wash the reaction solution with a 10% sodium bicarbonate solution, and then wash the product with distilled water until neutral. Collect the upper oil layer, remove water by vacuum distillation, and obtain the castor oil base oil.

[0024] Preparation Example 1.3 S1. Add 20g ricinoleic acid, 100g toluene, 12g catalyst Novozyme 435, and 22g hydrogen peroxide to 100g castor oil. Then, shake the reaction in a water bath at 50℃ and 250rpm for 22 hours. After 22 hours, take out the sample, remove the catalyst from the reaction solution by vacuum filtration, let it stand to separate the layers, remove the hydrogen peroxide from the lower layer, and then centrifuge the upper oil layer at high speed to remove any remaining catalyst and hydrogen peroxide. Then wash with a 2% sodium bicarbonate solution, followed by washing with distilled water until neutral to remove the water layer. Centrifuge the upper oil layer to remove water, and finally remove the organic solvent and residual water by rotary evaporation under reduced pressure to obtain primary castor oil-based base oil. S2. Add 300g of isooctanol to 100g of primary castor oil-based base oil obtained from S1, preheat, and purge with nitrogen. When the temperature of the reaction system reaches 80℃, add 0.65g of 98% concentrated sulfuric acid dropwise, then raise the temperature to 110℃ and react for 24h to complete the ring-opening reaction. Wash the completely reacted solution with a 2% sodium bicarbonate solution, then wash with distilled water until neutral, collect the upper oil layer, and remove water and organic alcohol solvent by vacuum distillation to obtain the ring-opening modified primary castor oil-based base oil. S3. Add 120g of hexanoic anhydride and 0.05g of catalyst 4-dimethylaminopyridine to 100g of the ring-opening modified primary castor oil base oil obtained from S2, purge with nitrogen, heat to 85℃, and react for 28h. Then add 120g of distilled water to the flask and continue the reaction for 3h to convert the organic acid anhydride into an organic acid. Then wash the reaction solution with a 10% sodium bicarbonate solution, and then wash the product with distilled water until neutral. Collect the upper oil layer, remove water by vacuum distillation, and obtain the castor oil base oil.

[0025] Preparation Example 2: Novel L-tryptophan-chitosan-hollow mesoporous nano-silica composite material Preparation Example 2.1 S1. Add 2g of chitosan powder to 120g of 1% acetic acid solution and stir continuously until the chitosan powder is completely dissolved to obtain a chitosan solution; add 5.64g of L-tryptophan to 60g of ethanol and dissolve by ultrasonic heating to obtain an L-tryptophan solution; then mix the chitosan solution and L-tryptophan solution and stir magnetically at 60℃ for 5h; after the reaction is completed, cool to room temperature; add 5% sodium hydroxide solution to precipitate, filter, and wash the precipitate with deionized water and ethanol in sequence to remove impurities; finally, dry the washed product at 60℃ for 20h to obtain the L-tryptophan-chitosan derivative; S2. Add 0.08g of silane coupling agent KH570 to 0.8g of deionized water and 7g of anhydrous ethanol, stir to dissolve, and obtain silane coupling agent solution. Then, mechanically stir and disperse for 10min, adjust pH to 3, add 2g of hollow mesoporous nano silica, mix evenly, and then disperse using an ultrasonic water bath for 30min. Then, heat to 70℃ and reflux under nitrogen protection for 10h. After the reaction is completed, vacuum filter, and dry the obtained sample to obtain KH570 modified hollow mesoporous nano silica. S3. Add 2g of KH570 modified hollow mesoporous nano silica prepared by S2 to 200g of deionized water and treat it with ultrasound for 1h to make it uniformly dispersed in the system; then add 2g of L-tryptophan-chitosan derivative prepared by S1 and stir to dissolve, and stir magnetically at 50℃ for 3h; after the reaction is completed, centrifuge the mixed solution, take the supernatant and dry it at 60℃ for 65h to obtain the new L-tryptophan-chitosan-hollow mesoporous nano silica composite material.

[0026] Preparation Example 2.2 S1. Add 2.5g of chitosan powder to 140g of 1% acetic acid solution and stir continuously until the chitosan powder is completely dissolved to obtain a chitosan solution; add 7.05g of L-tryptophan to 75g of ethanol and dissolve by ultrasonic heating to obtain an L-tryptophan solution; then mix the chitosan solution and L-tryptophan solution and stir magnetically at 65℃ for 6h; after the reaction is completed, cool to room temperature; add 5% sodium hydroxide solution to precipitate, filter, and wash the precipitate with deionized water and ethanol in sequence to remove impurities; finally, dry the washed product at 65℃ for 24h to obtain the L-tryptophan-chitosan derivative; S2. Add 0.1g of silane coupling agent KH570 to 1.0g of deionized water and 8.8g of anhydrous ethanol, stir to dissolve, and then mechanically stir to disperse for 20min. Adjust the pH to 3.5, add 2.5g of hollow mesoporous nano silica, mix evenly, and then disperse using an ultrasonic water bath for 40min. Then raise the temperature to 75℃ and reflux under nitrogen protection for 12h. After the reaction is completed, vacuum filter and dry the obtained sample to obtain KH570 modified hollow mesoporous nano silica. S3. Add 2.5g of KH570 modified hollow mesoporous nano-silica obtained from S2 to 250g of deionized water and treat with ultrasound for 1.5h to make it uniformly dispersed in the system; then add 2.5g of L-tryptophan-chitosan derivative obtained from S1 and stir to dissolve, and stir magnetically at 55℃ for 4h; after the reaction is completed, centrifuge the mixed solution, take the supernatant and dry it at 65℃ for 72h to obtain the new L-tryptophan-chitosan-hollow mesoporous nano-silica composite material.

[0027] Preparation Example 2.3 S1. Add 3g of chitosan powder to 160g of 1% acetic acid solution and stir continuously until the chitosan powder is completely dissolved to obtain a chitosan solution; add 8.46g of L-tryptophan to 90g of ethanol and dissolve by ultrasonic heating to obtain an L-tryptophan solution; then mix the chitosan solution and L-tryptophan solution and stir magnetically at 70℃ for 7h; after the reaction is completed, cool to room temperature; add 5% sodium hydroxide solution to precipitate, filter, and wash the precipitate with deionized water and ethanol in sequence to remove impurities; finally, dry the washed product at 70℃ for 28h to obtain the L-tryptophan-chitosan derivative; S2. Add 0.12g of silane coupling agent KH570 to 1.2g of deionized water and 10.6g of anhydrous ethanol, stir to dissolve, and obtain silane coupling agent solution. Then, mechanically stir and disperse for 30min, adjust pH to 4, add 3g of hollow mesoporous nano silica, mix evenly, and then disperse using an ultrasonic water bath for 50min. Then, heat to 80℃ and reflux under nitrogen protection for 14h. After the reaction is completed, vacuum filter, and dry the obtained sample to obtain KH570 modified hollow mesoporous nano silica. S3. Add 3g of KH570 modified hollow mesoporous nano silica prepared by S2 to 300g of deionized water and treat with ultrasound for 2h to make it uniformly dispersed in the system; then add 3g of L-tryptophan-chitosan derivative prepared by S1 and stir to dissolve, and stir magnetically at 60℃ for 5h; after the reaction is completed, centrifuge the mixed solution, take the supernatant and dry it at 70℃ for 80h to obtain the new L-tryptophan-chitosan-hollow mesoporous nano silica composite material.

[0028] Example 1 45g of castor oil-based base oil prepared in Preparation Example 1.1 was heated and stirred at 50°C. Then, 4g of film-forming agent butyl paraffin oxide, 3g of rust inhibitor, 0.6g of antioxidant Vanlube 7723, 1.5g of the novel composite material of additive-tryptophan-chitosan-hollow mesoporous nano silica prepared in Preparation Example 2.1, 1g of surfactant, and 0.2g of pour point depressant polymethyl methacrylate were added sequentially. The mixture was stirred at a constant temperature and high speed at 50°C for 2 hours. After filtration through a 5μm bag, an environmentally friendly bearing rust-preventive oil was obtained. The rust inhibitor is composed of calcium petroleum sulfonate, zinc naphthenate, and benzotriazole in a mass ratio of 2:1:0.1. The surfactant is composed of Span-80 and Tween-80 in a mass ratio of 1:0.5.

[0029] Example 2 50g of castor oil-based base oil prepared in Preparation Example 1.1 was heated and stirred at 55°C. Then, 5g of film-forming agent butyl paraffin oxide, 5g of rust inhibitor, 0.8g of antioxidant Vanlube 7723, 1.5g of novel composite material of additive-tryptophan-chitosan-hollow mesoporous nano silica prepared in Preparation Example 2.1, 1.5g of surfactant, and 0.3g of pour point depressant polymethyl methacrylate were added sequentially. The mixture was stirred at a constant temperature and high speed at 55°C for 3 hours. After filtration through a 5μm bag, an environmentally friendly bearing rust-preventive oil was obtained. The rust inhibitor is composed of calcium petroleum sulfonate, zinc naphthenate, and benzotriazole in a mass ratio of 2.5:1.5:0.2. The surfactant is composed of Span-80 and Tween-80 in a mass ratio of 1:0.55.

[0030] Example 3 55g of castor oil-based base oil prepared in Preparation Example 1.1 was heated and stirred at 60°C. Then, 6g of film-forming agent butyl paraffin oxide, 7g of rust inhibitor, 1g of antioxidant Vanlube 7723, 1.5g of the novel composite material of additive-tryptophan-chitosan-hollow mesoporous nano silica prepared in Preparation Example 2.1, 2g of surfactant, and 0.4g of pour point depressant polymethyl methacrylate were added sequentially. The mixture was stirred at a constant temperature of 60°C at high speed for 4 hours. After filtration through a 5μm bag, an environmentally friendly bearing rust-preventive oil was obtained. The rust inhibitor is composed of calcium petroleum sulfonate, zinc naphthenate, and benzotriazole in a mass ratio of 3:2:0.3. The surfactant is composed of Span-80 and Tween-80 in a mass ratio of 1:0.6.

[0031] Example 4 The difference between Example 4 and Example 1 is that the castor oil-based base oil used in Example 4 was prepared from Preparation Example 1.2.

[0032] Example 5 The difference between Example 5 and Example 1 is that the castor oil-based base oil used in Example 5 was prepared from Preparation Example 1.3.

[0033] Example 6 The difference between Example 6 and Example 1 is that the novel composite material of tryptophan-chitosan-hollow mesoporous nano silica used in Example 6 was prepared by Preparation Example 2.2 and the mass was 1.5g.

[0034] Example 7 The difference between Example 7 and Example 1 is that the novel composite material of additive-tryptophan-chitosan-hollow mesoporous nano silica used in Example 7 was prepared by Preparation Example 2.3 and the mass was 1.5g.

[0035] Example 8 The difference between Example 8 and Example 1 is that the novel composite material of tryptophan-chitosan-hollow mesoporous nano-silica used in Example 8 was prepared by Example 2.1 and the mass was 2g.

[0036] Example 9 The difference between Example 9 and Example 1 is that the novel composite material of additive-tryptophan-chitosan-hollow mesoporous nano silica used in Example 9 was prepared by Preparation Example 2.1 and the mass was 2.5g.

[0037] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that the novel composite material of additive-tryptophan-chitosan-hollow mesoporous nano-silica used in Comparative Example 1 was prepared by Preparation Example 2.1 and had a mass of 0g.

[0038] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that the novel composite material of additive-tryptophan-chitosan-hollow mesoporous nano-silica used in Comparative Example 2 was prepared by Example 2.1 and weighed 4g.

[0039] Performance testing The performance of the environmentally friendly bearing rust-preventive oils obtained in Examples 1-9 and Comparative Examples 1-2 was tested. The test methods and test results are shown in Table 1.

[0040] The specific test results are as follows: Table 1 Performance Test Results

[0041] As shown in the test results in Table 1, the environmentally friendly rust-preventive oil provided in this application has excellent oxidation stability and good stability. The oil does not precipitate or separate into layers after long-term storage. It is suitable for rust prevention of bearings and their parts and can meet the requirements for rust prevention period of six months or more.

[0042] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. An environmentally friendly bearing rust-preventive oil, characterized in that: The raw materials, by weight, include 45-55 parts base oil, 4-6 parts film-forming agent, 3-7 parts rust inhibitor, 0.6-1 part antioxidant, 1.5-2.5 parts additives, 1-2 parts surfactant, and 0.2-0.4 parts pour point depressant; the base oil is castor oil-based base oil; the additives are a novel composite material of L-tryptophan-chitosan-hollow mesoporous nano-silica.

2. The environmentally friendly bearing rust-preventive oil according to claim 1, characterized in that: The novel L-tryptophan-chitosan-hollow mesoporous nano-silica composite material is prepared from the following raw materials in parts by weight: 2-3 parts KH570 modified hollow mesoporous nano-silica, 200-300 parts deionized water, and 2-3 parts L-tryptophan-chitosan derivative.

3. The environmentally friendly bearing rust-preventive oil according to claim 1, characterized in that: The method for preparing the castor oil-based base oil includes the following steps: S1. Add ricinoleic acid, organic solvent, catalyst Novozyme 435, and hydrogen peroxide to castor oil. Then, shake the reaction in a water bath at 40-50℃ and 200-250 rpm for 15-22 hours. After that, take out the sample, remove the catalyst from the reaction solution by vacuum filtration, let it stand to separate the layers, remove the hydrogen peroxide from the lower layer, and then centrifuge the upper oil layer at high speed to remove any remaining catalyst and hydrogen peroxide. Then, wash with sodium bicarbonate solution and distilled water to remove the water layer. Centrifuge the upper oil layer to remove water, and finally remove the organic solvent and residual water by vacuum rotary evaporation to obtain the primary castor oil base oil. S2. Add isooctanol to the primary castor oil-based base oil obtained in S1, preheat, and purge with nitrogen. When the temperature of the reaction system reaches 70-80℃, add concentrated sulfuric acid dropwise, then raise the temperature to 100-110℃ and react for 12-24 hours to complete the ring-opening reaction. Wash the completely reacted solution with sodium bicarbonate solution and distilled water, collect the upper oil layer, and remove water and organic alcohol solvent by vacuum distillation to obtain the ring-opening modified primary castor oil-based base oil. S3. Add hexanoic anhydride and catalyst 4-dimethylaminopyridine to the ring-opening modified primary castor oil base oil obtained in S2, purge with nitrogen, heat to 75-85℃, and react for 20-28 hours. Then add distilled water to the flask and continue the reaction for 1-3 hours to convert the organic acid anhydride into an organic acid. Then wash the reaction solution with sodium bicarbonate solution and water, collect the upper oil layer, and remove the water by vacuum distillation to obtain the castor oil base oil.

4. The environmentally friendly bearing rust-preventive oil according to claim 3, characterized in that: In S1, the mass ratio of castor oil, organic solvent, catalyst Novozyme 435, ricinoleic acid, and hydrogen peroxide is 1:0.95-1:0.1-0.12:0.16-0.2:0.2-0.

22.

5. The environmentally friendly bearing rust-preventive oil according to claim 3, characterized in that: The mass ratio of isooctanol and concentrated sulfuric acid in the primary castor oil base oil described in S2 is 1:2.8-3:0.006-0.0065.

6. The environmentally friendly bearing rust-preventive oil according to claim 3, characterized in that: The mass ratio of the ring-opening modified primary castor oil base oil, hexanoic anhydride, and catalyst 4-dimethylaminopyridine described in S3 is 1:1-1.2:0.0003-0.0005.

7. The environmentally friendly bearing rust-preventive oil according to claim 2, characterized in that: The preparation method of the novel L-tryptophan-chitosan-hollow mesoporous nano-silica composite material includes the following steps: Add 2-3 parts of KH570 modified hollow mesoporous nano silica to 200-300 parts of deionized water and treat with ultrasound for 1-2 hours to disperse it evenly in the system; then add 2-3 parts of L-tryptophan-chitosan derivative and stir to dissolve, and magnetically stir at 50-60℃ for 3-5 hours; after the reaction, centrifuge the mixed solution, take the supernatant and dry it at 60-70℃ for 65-80 hours to obtain the novel L-tryptophan-chitosan-hollow mesoporous nano silica composite material.

8. The environmentally friendly bearing rust-preventive oil according to claim 2, characterized in that: The method for preparing the L-tryptophan-chitosan derivative, Includes the following steps: By weight, 2-3 parts of chitosan powder were added to 120-160 parts of a 1% acetic acid solution, and the mixture was stirred continuously until the chitosan powder was completely dissolved to obtain a chitosan solution. 5.64-8.46 parts of L-tryptophan were added to 60-90 parts of ethanol, and the mixture was ultrasonically heated to dissolve the L-tryptophan solution. The chitosan solution and L-tryptophan solution were then mixed and magnetically stirred at 60-70°C for 5-7 hours. After the reaction was completed, the mixture was cooled to room temperature. Sodium hydroxide solution was added to precipitate the product, which was then filtered. The precipitate was washed successively with deionized water and ethanol to remove impurities. Finally, the washed product was dried at 60-70°C for 20-28 hours to obtain the L-tryptophan-chitosan derivative. The preparation method of the KH570 modified hollow mesoporous nano silica includes the following steps: By weight, 0.08-0.12 parts of silane coupling agent KH570 were added to 0.8-1.2 parts of water and 7-10.6 parts of anhydrous ethanol, stirred and dissolved to obtain a silane coupling agent solution. The solution was then mechanically stirred and dispersed for 10-30 minutes. The pH was adjusted to 3-4, and 2-3 parts of hollow mesoporous nano-silica were added. After mixing evenly, the solution was dispersed in an ultrasonic water bath for 30-50 minutes. The temperature was then raised to 70-80℃ and refluxed under nitrogen protection for 10-14 hours. After the reaction was completed, the solution was vacuum filtered. The obtained sample was dried to obtain KH570 modified hollow mesoporous nano-silica.

9. The environmentally friendly bearing rust-preventive oil according to claim 1, characterized in that: The rust inhibitor is composed of calcium petroleum sulfonate, zinc naphthenate, and benzotriazole in a mass ratio of 2-3:1-2:0.1-0.

3. The film-forming agent is butyl paraffin oxide; The antioxidant is Vanlube 7723.

10. A method for preparing an environmentally friendly bearing rust-preventive oil according to any one of claims 1-9, characterized in that: Includes the following steps: Heat and stir 45-55 parts of base oil at 50-60℃, then add 4-6 parts of film-forming agent, 3-7 parts of rust inhibitor, 0.6-1 part of antioxidant, 1.5-2.5 parts of additives, 1-2 parts of surfactant, and 0.2-0.4 parts of pour point depressant in sequence. Stir at a constant temperature of 50-60℃ for 2-4 hours. After filtration through a 5μm bag, the environmentally friendly bearing rust-preventive oil is obtained.

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