Long-acting salt-mist-resistant anti-rust oil and preparation method thereof

Abstract

The invention relates to the technical field of anti-rust oil processing, in particular to long-acting salt-mist-resistant anti-rust oil and a preparation method thereof. The lubricating oil is prepared from the following raw materials in parts by weight: 60-80 parts of base oil, 0.5-1 part of an antioxidant, 2-4 parts of a film-forming agent, 10-15 parts of an antirust agent, 8-12 parts of a surfactant, 1-3 parts of acidic phosphate, 2-4 parts of N-oleoyl sarcosine, 1-2 parts of sodium dioctyl sulfosuccinate and 5-10 parts of fatty alcohol. The surface active agent is prepared from sodium lauroamphoacetate, cocamidopropyl betaine and fatty amine polyoxyethylene ether; the long-acting salt-mist-resistant anti-rust oil can effectively solve the problems of short service life, high antirust agent content, insufficient adhesive force and the like of the anti-rust oil, and is suitable for severe sea transportation environments with high salt mist, strong vibration and high humidity; and the salt-mist-resistant protection requirement for long-term storage of the metal workpiece for more than one year can be met.

Description

Technical Field

[0001] This application relates to the field of rust-preventive oil processing technology, and more specifically, to a long-lasting salt spray resistant rust-preventive oil and its preparation method. Background Technology

[0002] In industrial production, a large number of metal workpieces need to be transported across regions by sea, and often require long-term storage of more than one year during sea transport and subsequent storage due to supply chain scheduling and warehousing planning needs. However, the sea transport environment has significant high salt spray characteristics, and the marine atmosphere has extremely high content of salts such as sodium chloride, which easily adsorbs onto the surface of workpieces, corrodes them, and seriously affects the dimensional accuracy, mechanical properties, and subsequent reliability of the workpieces.

[0003] To improve the salt spray resistance of workpieces, rust-preventive oil is usually coated on their surface. Currently, commonly used rust-preventive oils in the industrial field mainly include three types: solvent-based, oil-based, and water-based. Although solvent-based rust-preventive oils have the advantages of strong penetration and fast film formation, the solvent is prone to slow evaporation during long-term storage, resulting in a gradual reduction in the oil film thickness and a continuous decline in salt spray resistance. They can usually only meet the short-term protection requirements for 3-6 months. Oil-based rust-preventive oils have higher viscosity and better oil film sealing, but their salt spray resistance depends on the synergistic effect of the base oil and the rust inhibitor. Commonly used rust inhibitors in existing formulations, such as barium sulfonate and zinc naphthenate, are prone to complexation reactions with chloride ions in high salt spray environments, losing their adsorption and rust-preventing ability. After one year of storage, the oil film is prone to blistering and peeling. Water-based rust-preventive oils are environmentally friendly and easy to clean, but the water-based system itself has strong conductivity, which can accelerate electrochemical corrosion in salt spray environments. Its salt spray resistance is the worst and it is difficult to meet the requirements for long-term storage at sea.

[0004] Furthermore, existing rust-preventive oils have other limitations in long-term seaborne storage scenarios: some products excessively increase the rust inhibitor content to improve salt spray resistance, leading to increased oil film hardness and brittleness, making them prone to cracking under the vibration and impact of ship turbulence; some products have insufficient adhesion to the workpiece surface, and in the high-humidity marine environment, the oil film is easily peeled off due to water penetration. In summary, existing rust-preventive oil technology cannot effectively solve the problem of salt spray protection for workpieces stored at sea for more than a year. Developing a new type of rust-preventive oil with long-lasting salt spray resistance, good stability, and compatibility has become a key technical problem urgently needing to be solved in the industrial field. Summary of the Invention

[0005] To address the problems of short service life, high rust inhibitor content, and insufficient adhesion of rust-preventive oils, this application provides a long-lasting salt spray resistant rust-preventive oil and its preparation method.

[0006] In the first aspect, this application provides a long-lasting anti-salt spray rust-preventive oil, which adopts the following technical solution: A long-lasting anti-salt spray rust-preventive oil is prepared from the following raw materials in parts by weight: 60-80 parts base oil Antioxidant 0.5-1 part 2-4 parts of film-forming agent 10-15 parts rust inhibitor 8-12 parts of surfactant 1-3 parts of acidic phosphate 2-4 parts of N-oleoylsarcosine 1-2 parts of sodium dioctyl sulfosuccinate 5-10 parts fatty alcohol The surfactant is composed of sodium lauroyl amphoteric acid, cocamidopropyl betaine, and fatty amine polyoxyethylene ether. The fatty alcohol is composed of higher carbon fatty alcohols and isomer fatty alcohols.

[0007] By adopting the above technical solutions, a long-lasting salt spray rust-preventive oil can be prepared, which can effectively solve the problems of short service life, high rust inhibitor content and insufficient adhesion of rust-preventive oil. It is suitable for the harsh environment of high salt spray, strong vibration and high humidity in sea transportation, and can meet the salt spray protection requirements of metal workpieces for long-term storage for more than one year.

[0008] This application uses base oil as the main component, without any easily volatile solvents. When combined with film-forming agents, it can form a continuous, dense, and physically stable oil film matrix, thus avoiding the problem of "oil film thinning as solvent evaporates" in solvent-based rust inhibitors from the root. At the same time, the addition of antioxidants can delay the oxidative aging of the base oil and oil film, and extend the service life of the oil film.

[0009] N-Oleylsarcosine exhibits strong adsorption to metal surfaces and is not prone to complexation with chloride ions in salt spray. Sodium dioctyl sulfonate enhances the oil film's barrier properties against salt spray. Together with the rust inhibitor, they synergistically prevent the blistering and peeling problems associated with oil-based rust inhibitors due to inhibitor failure. This application uses a small amount of rust inhibitor, reducing the risk of increased hardness and brittleness in the rust inhibitor from the outset.

[0010] Acidic phosphate esters can chemically adsorb and even slightly react with the surface of metal workpieces, forming a strong chemically adsorbed film. This film preferentially blocks chloride ions and water molecules in salt spray from contacting the metal substrate, further extending the protective life to more than one year. In other words, the chemical film-forming effect of acidic phosphate esters can directly supplement rust prevention, eliminating the need for large amounts of rust inhibitors. The synergistic effect of both allows for long-lasting protection with "low dosage of rust inhibitor," preventing the oil film from becoming brittle. Surfactants can significantly reduce the interfacial tension between the oil film and the metal surface, allowing the oil film to tightly adhere to the tiny irregularities on the workpiece surface, reducing interfacial voids, and further improving the adhesion of the rust-preventive oil film. The composite fatty alcohol, composed of high-carbon fatty alcohol and isomeric fatty alcohol, can improve the mechanical properties of the oil film. The high-carbon fatty alcohol ensures the basic strength, while the isomeric fatty alcohol enhances the elasticity and impact resistance of the film, making the oil film less prone to cracking under the vibration and impact of ship turbulence.

[0011] Preferably, the weight ratio of the sodium lauroamphoacetate, the cocamidopropyl betaine, and the fatty amine polyoxyethylene ether is (2-6):(4-8):1.

[0012] By adopting the above technical solution, the amount of surfactant is optimized. Cocamidopropyl betaine is used as the main wetting component to quickly reduce interfacial tension and penetrate microscopic defects in the workpiece. Sodium lauroylamphoacetate helps to enhance the affinity of the oil film, and fatty amine polyoxyethylene ether inhibits oil film shrinkage through steric hindrance. The three work together to achieve no dead angle coverage of the rust-preventive oil and improve the adhesion performance of the rust-preventive oil.

[0013] Preferably, the weight ratio of the higher carbon fatty alcohol to the isomeric fatty alcohol is (3-5):1.

[0014] By adopting the above technical solutions and optimizing the amount of fatty alcohol, higher carbon fatty alcohols form a tight interaction with base oil and film-forming agents with long straight-chain molecules, providing core strength and hardness for the oil film and resisting chloride ion penetration and erosion; isomer fatty alcohols reduce the crystallinity and brittleness of the oil film. The two work together to solve the contradiction between strength and toughness, so that the oil film can resist salt spray erosion and absorb the vibration energy of ship turbulence, thus avoiding crack formation.

[0015] Preferably, the higher carbon fatty alcohols include at least one of cetyl alcohol, stearyl alcohol, and behenyl alcohol.

[0016] By adopting the above technical solutions and optimizing the types of high-carbon fatty alcohols, they can form tight intermolecular forces with base oils and film-forming agents, providing mechanical support for the oil film, enhancing the structural strength against chloride ion penetration in salt spray, strengthening the density of the physical barrier, and improving impermeability. Simultaneously, the three components are chemically stable and have excellent compatibility with non-polar base oils. Combined with isomeric fatty alcohols, they solidify the foundation of oil film strength and impermeability, ensuring system stability and precisely meeting the requirements for long-term storage at sea.

[0017] Preferably, the base oil is composed of paraffinic base, dodecanedicarboxylic acid and refined mineral oil in a weight ratio of (8-10):(2-4):5.

[0018] By adopting the above technical solutions, the types and amounts of base oils are optimized, thereby improving the long-term protective capability, film adhesion, and system stability of the rust inhibitor, and precisely meeting the stringent requirements of long-term storage at sea.

[0019] A high proportion of paraffin-based materials, with their low volatility and high viscosity index, forms the protective matrix, completely avoiding the thinning problem caused by the evaporation of solvent-based oil films. Furthermore, its excellent viscosity-temperature properties allow it to adapt to the temperature variations during sea transport, preventing sagging at high temperatures and solidification at low temperatures, thus ensuring the long-term integrity of the oil film. Dodecanoic acid forms a chemical adsorption with the metal surface through its dicarboxyl groups, enhancing interfacial bonding. Its polar structure also fills gaps in the matrix network, improving oil film density and blocking chloride ion penetration. Refined mineral oil acts as a "compatibility bridge," harmonizing the strong non-polarity of the paraffin-based materials with the polarity of the dodecanoic acid, while simultaneously promoting the uniform dispersion of functional components such as rust inhibitors and fatty alcohols, preventing agglomeration and failure. These three components work synergistically to provide a stable substrate, strong adsorption, and a dense structure for the oil film, precisely supporting the salt spray resistance requirements of long-term sea transport.

[0020] Preferably, the refined mineral oil includes at least one of 60SN, 100SN, 150SN, 500SN, 1000SN and cycloalkane-type refined oils.

[0021] By adopting the above technical solutions, the types of refined mineral oils are optimized to ensure strong compatibility with paraffin bases. This allows for efficient blending of polar and non-polar components, preventing stratification, while providing a uniformly dispersed carrier for functional components, ensuring stable oil film structure, and further solidifying the long-term protective foundation of base oils.

[0022] Preferably, the rust inhibitor is composed of zinc naphthenate and polypropylene glycol ether in a weight ratio of (5-9):3.

[0023] By adopting the above technical solutions, the type and dosage of rust inhibitors are optimized, further enhancing the long-term salt spray resistance of the rust-preventive oil. Zinc naphthenate, as the primary rust inhibitor, allows its zinc ions to form a robust chemical adsorption film with active sites on the metal surface, while the naphthenic groups are oriented to form a hydrophobic barrier, effectively blocking chloride ion penetration. Polypropylene glycol plays a key synergistic role: its polar ether groups can form hydrogen bonds with zinc naphthenate, strengthening the density of the adsorption film; its flexible molecular chains can fill the microscopic gaps in the adsorption film, further blocking the channels of corrosive media. Simultaneously, at this ratio, polypropylene glycol ethers can inhibit the aggregation tendency of zinc naphthenate, ensuring its uniform dispersion in the base oil and guaranteeing full coverage of the metal surface. Furthermore, the oleophilic end of polypropylene glycol ethers exhibits excellent compatibility with the base oil, enhancing the bonding force between the rust inhibitor and the oil film matrix, preventing protective failure caused by oil film vibration and detachment.

[0024] Preferably, the film-forming agent is composed of pentaerythritol lanolinate and diethanolamide oleate in a weight ratio of (4-8):3.

[0025] By adopting the above technical solutions and optimizing the type and dosage of film-forming agents, the adhesion of the rust-preventive oil film is further improved, solving problems such as insufficient density, easy peeling, and poor impact resistance of traditional oil films, thus meeting the requirements of harsh marine environments. Pentaerythritol lanolinate contains multiple polar ester groups and long-chain alkyl groups, which can form a strong adsorption on the metal surface through polarity and also tightly bind with base oil molecules, constructing a continuous and uniform base oil film framework, giving the film structural strength, and initially blocking the penetration of chloride ions and water molecules in salt spray. The amide and hydroxyl groups of oleic acid diethanolamide can form hydrogen bonds with the ester groups of pentaerythritol lanate, and can also coordinate with the zinc ions of zinc naphthenate in rust inhibitors, further densifying the microstructure of the oil film, filling the gaps in the basic film layer, and significantly compressing the penetration path of corrosive media; moreover, the flexible molecular chains can neutralize the rigidity of the main film-forming agent, improve the elasticity of the oil film, and enable it to absorb the vibration energy of ship turbulence, thus preventing crack formation; finally, its strong polar groups enhance the chemical adsorption between the oil film and the metal surface, and combined with the improved wettability of the composite surfactant, it completely solves the problem of oil film peeling in high humidity environments.

[0026] Preferably, the antioxidant is composed of benzotriazole and phenolic antioxidant in a weight ratio of (2-3):1.

[0027] By adopting the above technical solutions, optimizing the type and amount of oxidant, the antioxidant properties of rust-preventive oil are further improved, effectively delaying the oxidative degradation of the oil film, maintaining the film layer's density and integrity, and providing continuous antioxidant protection for more than one year of seaborne storage.

[0028] Secondly, this application provides a method for preparing a long-lasting anti-salt spray rust-preventive oil, using the following technical solution: A method for preparing a long-lasting anti-salt spray rust-preventive oil involves melting all the base oil and fatty alcohol, adding a surfactant and stirring until homogeneous, then adding an antioxidant, rust inhibitor, film-forming agent, acidic phosphate ester, N-oleoylsarcosine and sodium dioctyl sulfosuccinate, and stirring until homogeneous to obtain the long-lasting anti-salt spray rust-preventive oil.

[0029] By adopting the above technical solution, the base oil and fatty alcohol are completely melted and mixed. The high carbon straight chain and isomer branches of the fatty alcohol can be fully interspersed in the molecular network of the base oil, avoiding the imbalance of film strength and toughness caused by local aggregation, and forming a uniform dispersion substrate.

[0030] In summary, this application has the following beneficial effects: 1. This application uses base oil as the main component and contains no volatile solvents. Combined with a film-forming agent, it forms a stable oil film matrix, preventing the oil film from thinning due to solvent evaporation. Antioxidants are used to delay oil film oxidation and aging, extending the service life of the oil film. The amount of rust inhibitor used is small. N-oleoylsarcosine and sodium dioctyl sulfonate succinate work synergistically with the rust inhibitor, preventing rust inhibitor failure and reducing the risk of increased hardness and brittleness of the rust-preventive oil from the source. Surfactants significantly reduce the interfacial tension between the oil film and the metal surface, allowing the oil film to adhere tightly to the workpiece, reducing interfacial voids and improving oil film adhesion. Acidic phosphate esters form a chemical adsorption film, preferentially blocking chloride ions and water molecules, working synergistically with the rust inhibitor to achieve long-term protection. The synergistic effect of all components makes it suitable for high-salt-spray environments in marine environments, meeting the salt-spray resistance requirements for metal workpieces stored for more than one year. High-carbon fatty alcohols in the fatty alcohols ensure basic strength, while isomerized fatty alcohols enhance elasticity and impact resistance, making the oil film less prone to cracking under vibration and impact. Detailed Implementation Example Example

[0031] A long-lasting salt spray resistant rust-preventive oil is prepared by the following method: Melt 600g of base oil and 50g of fatty alcohol, then add 80g of surfactant and stir well. Next, add 5g of antioxidant, 100g of rust inhibitor, 20g of film-forming agent, 10g of acidic phosphate ester, 20g of N-oleoylsarcosine and 10g of sodium dioctyl sulfosuccinate, and stir well to obtain a long-lasting salt spray rust-preventive oil.

[0032] The surfactant is composed of sodium lauroylamphoacetate, cocamidopropyl betaine, and fatty amine polyoxyethylene ether in a weight ratio of 2:4:1; Fatty alcohols consist of higher carbon fatty alcohols (cetyl alcohol) and isomer fatty alcohols (C6H ... 13 -Isomeric alcohols) are composed of a weight ratio of 3:1; The base oil is composed of paraffinic (150N paraffinic), dodecanedicarboxylic acid and refined mineral oil (60SN) in a weight ratio of 8:2:5; The rust inhibitor is composed of zinc naphthenate and polypropylene glycol ether in a weight ratio of 5:3; The film-forming agent is composed of pentaerythritol lanate and diethanolamide oleate in a weight ratio of 4:3; The antioxidant is composed of benzotriazole and a phenolic antioxidant (2,6-di-tert-butyl-p-cresol) in a weight ratio of 2:1.

[0033] The difference between Examples 2-3 and Example 1 lies in the types and amounts of raw materials and parameters used in preparing the long-lasting anti-salt spray rust-preventive oil. The specific differences are shown in Table 1. Table 1. Raw material types, dosages, and parameters for preparing long-lasting anti-salt spray rust-preventive oils in Examples 1-3.

[0034] In Example 2, the high-carbon fatty alcohol is stearyl alcohol, the isomeric fatty alcohol is isoundecyl alcohol, the paraffinic base is 150N paraffinic base, the refined mineral oil is 100SN, and the phenolic antioxidant is 2,6-di-tert-butylphenol.

[0035] In Example 3, the high-carbon fatty alcohol is behenol, the isomeric fatty alcohol is isotetradecyl alcohol, the paraffinic base is 60N paraffinic base, the refined mineral oil is 150SN, and the phenolic antioxidant is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid].

[0036] Example 2 A long-lasting anti-salt spray rust-preventing oil, the difference between this embodiment and Example 1 is that the surfactant is composed of sodium lauroylamphoacetate, cocamidopropyl betaine and fatty amine polyoxyethylene ether in a weight ratio of 2:2:1.

[0037] Example 3 A long-lasting anti-salt spray rust-preventive oil, the difference between this embodiment and Example 1 is that the fatty alcohol is composed of higher carbon fatty alcohol (cetyl alcohol) and isomer fatty alcohol (C... 13 -Isomeric alcohols) are composed of 1:1 by weight.

[0038] Example 4 A long-lasting anti-salt spray rust-preventive oil, the difference between this embodiment and embodiment 1 is that the base oil is composed of paraffinic base (150N paraffinic base) and refined mineral oil (60SN) in a weight ratio of 8:5.

[0039] Example 5 A long-lasting anti-salt spray rust-preventive oil, the difference between this embodiment and Example 1 is that the base oil is composed of paraffinic (150N paraffinic) and dodecanedicarboxylic acid in a weight ratio of 8:2.

[0040] Example 6 A long-lasting anti-salt spray rust-preventing oil, the difference between this embodiment and Example 1 is that the rust inhibitor is composed of barium cyclopetroleum sulfonate and polypropylene glycol ether in a weight ratio of 5:3.

[0041] Example 7 A long-lasting anti-salt spray rust-preventing oil, the difference between this embodiment and Example 1 is that the film-forming agent is composed of pentaerythritol lanolin and petrolatum in a weight ratio of 4:3.

[0042] Example 8 A long-lasting anti-salt spray rust-preventing oil, the difference between this embodiment and Example 1 is that the film-forming agent is pentaerythritol lanolinate.

[0043] Example 9 A long-lasting salt spray resistant rust-preventing oil, the difference between this embodiment and Embodiment 1 is that the rust inhibitor is zinc naphthenate.

[0044] Example 10 A long-lasting anti-salt spray rust-preventive oil, the difference between this embodiment and Embodiment 1 is that the antioxidant is benzotriazole.

[0045] Comparative Example Comparative Example 1 A salt spray rust-preventing oil, the difference between this comparative example and Example 1 is that the surfactant is composed of sodium lauroylamphoacetate and fatty amine polyoxyethylene ether in a weight ratio of 2:1.

[0046] Comparative Example 2 A salt spray rust-preventing oil, the difference between this comparative example and Example 1 is that the surfactant is sodium lauroylamphoacetate.

[0047] Comparative Example 3 A salt spray rust-preventive oil, the difference between this comparative example and Example 1 is that the fatty alcohol is a high-carbon fatty alcohol (cetyl alcohol).

[0048] Comparative Example 4 A salt spray rust-preventive oil, the difference between this comparative example and Example 1 is that no acidic phosphate ester is added.

[0049] Comparative Example 5 A salt spray rust-preventive oil, the difference between this comparative example and Example 1 is that N-oleoylsarcosine is not added.

[0050] Comparative Example 6 A salt spray rust-preventive oil, the difference between this comparative example and Example 1 is that sodium salicylate is used instead of sodium dioctyl sulfosuccinate.

[0051] Detection methods / test methods Alternating salt spray test: Q235 steel test pieces with dimensions of 100mm×50mm×2mm were selected and coated with the long-lasting anti-salt spray rust-preventive oil of Examples 1-10 and the long-lasting anti-salt spray rust-preventive oil of Comparative Examples 1-6, respectively. The test was then carried out using Method 7 in GB / T2423.18-2021. After each cycle, the state of the oil film on the surface of the test piece was observed, such as whether there were cracks, blistering, peeling, etc. If the above conditions did not appear after more than 100 cycles, the experiment was stopped. Oil film adhesion test: Q235 steel test pieces with dimensions of 100mm×50mm×2mm were selected and coated with the long-lasting anti-salt spray rust-preventive oil of Examples 1-10 and the long-lasting anti-salt spray rust-preventive oil of Comparative Examples 1-6, respectively. A grid of 10×10 was drawn on the surface of the oil film with a cross-cutting knife (grid spacing of 1mm, depth penetrating the oil film to the substrate). Debris was removed with a soft brush, and 3M 600 tape was applied (pressure 5N / cm²). After standing for 1 minute, the film was quickly peeled off vertically. The degree of oil film peeling at the grid edge was divided into 0-5 grades according to the standard (grade 0: no peeling, grade 5: complete peeling).

[0052] Vibration and shock resistance test: Q235 steel specimens with dimensions of 100mm×50mm×2mm were selected and coated with the long-lasting anti-salt spray rust-preventive oils of Examples 1-10 and Comparative Examples 1-6, respectively. An electromagnetic vibration table was prepared, and the samples were placed on the vibration table fixture. The vibration direction was vertical + horizontal, the frequency was 200Hz (frequency sweep), the acceleration was 5g, and the vibration was continued for 200h. The cracking and peeling of the oil film after vibration were observed (under magnification; crack width ≤0.1mm was considered qualified). The experimental data are shown in Table 2: Table 2 Experimental data of Examples 1-10 and Comparative Examples 1-6

[0053] As can be seen from the data of Example 1 and Comparative Examples 1-2, sodium lauroamphoacetate, cocamidopropyl betaine and fatty amine polyoxyethylene ether can greatly improve the ability of rust-preventive oil to resist salt spray corrosion, oil film adhesion and vibration and shock resistance, providing better protection for metal workpieces in harsh environments such as sea transport.

[0054] As can be seen from the data of Example 1 and Comparative Example 3, by combining high-carbon fatty alcohols and isomer fatty alcohols in a specific ratio, a synergistic effect can be achieved in terms of salt spray resistance, oil film adhesion, and vibration and shock resistance, thus providing better overall performance for rust-preventive oils.

[0055] As can be seen from the data of Example 1 and Comparative Examples 4-6, acidic phosphate, N-oleoylsarcosine and sodium dioctyl sulfosuccinate not only play a role in salt spray resistance, but also have a positive impact on the vibration and shock resistance of the oil film, which helps to enhance the toughness and stability of the oil film, making it less prone to cracking when subjected to vibration and shock.

[0056] Data from Examples 1 and 4-5 show that dodecanedicarboxylic acid plays a positive role in improving the salt spray resistance of rust-preventive oils in base oil formulations. It may enhance interfacial bonding by forming chemical adsorption with metal surfaces, and improve the density of the oil film by filling the voids in the matrix network, thereby better blocking chloride ion penetration.

[0057] Data from Examples 1 and 5 show that dodecanoic acid enhances interfacial bonding through chemical adsorption to metal surfaces, and refined mineral oil harmonizes various components and promotes the dispersion of functional components. Both are crucial for improving salt spray resistance and oil film adhesion.

[0058] As can be seen from the data in Examples 1, 6, and 9, the combination of zinc naphthenate and polypropylene glycol ether in a specific ratio in the formulation can improve the salt spray resistance and overall performance of the oil film of the rust-preventive oil.

[0059] As can be seen from the data in Examples 1 and 7-8, by using pentaerythritol lanate and diethanolamide oleate in a specific ratio, the salt spray resistance and overall performance of the oil film of the rust-preventive oil can be improved.

[0060] As can be seen from the data of Examples 1 and 10, by using benzotriazole and phenolic antioxidants in a specific ratio, the oxidative degradation of the oil film can be delayed more effectively, and the film layer can be maintained densely and intact.

[0061] 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. A long-lasting anti-salt spray rust-preventive oil, characterized in that, It is prepared from the following raw materials in parts by weight: 60-80 parts base oil Antioxidant 0.5-1 part 2-4 parts of film-forming agent 10-15 parts rust inhibitor 8-12 parts of surfactant 1-3 parts of acidic phosphate 2-4 parts of N-oleoylsarcosine 1-2 parts of sodium dioctyl sulfosuccinate 5-10 parts fatty alcohol The surfactant is composed of sodium lauroyl amphoteric acid, cocamidopropyl betaine, and fatty amine polyoxyethylene ether. The fatty alcohol is composed of higher carbon fatty alcohols and isomer fatty alcohols.

2. The long-lasting anti-salt spray rust-preventive oil according to claim 1, characterized in that: The weight ratio of the sodium lauroylamphoteric acid, the cocamidopropyl betaine, and the fatty amine polyoxyethylene ether is (2-6):(4-8):

1.

3. The long-lasting anti-salt spray rust-preventive oil according to claim 1, characterized in that: The weight ratio of the higher carbon fatty alcohol to the isomeric fatty alcohol is (3-5):

1.

4. The long-lasting anti-salt spray rust-preventive oil according to claim 3, characterized in that: The higher fatty alcohols include at least one of cetyl alcohol, stearyl alcohol, and behenyl alcohol.

5. The long-lasting anti-salt spray rust-preventive oil according to claim 1, characterized in that: The base oil is composed of paraffinic base, dodecanedicarboxylic acid and refined mineral oil in a weight ratio of (8-10):(2-4):

5.

6. The long-lasting anti-salt spray rust-preventive oil according to claim 5, characterized in that: The refined mineral oil includes at least one of 60SN, 100SN, 150SN, 500SN, 1000SN, and cycloalkane-type refined oils.

7. The long-lasting anti-salt spray rust-preventive oil according to claim 1, characterized in that: The rust inhibitor is composed of zinc naphthenate and polypropylene glycol ether in a weight ratio of (5-9):

3.

8. The long-lasting anti-salt spray rust-preventive oil according to claim 1, characterized in that: The film-forming agent is composed of pentaerythritol lanolinate and diethanolamide oleate in a weight ratio of (4-8):

3.

9. The long-lasting anti-salt spray rust-preventive oil according to claim 1, characterized in that: The antioxidant is composed of benzotriazole and phenolic antioxidants in a weight ratio of (2-3):

1.

10. A method for preparing a long-lasting anti-salt spray rust-preventive oil as described in any one of claims 1-9, characterized in that, The preparation steps include the following: Melt the base oil and fatty alcohol completely, then add the surfactant and stir until homogeneous. Next, add the antioxidant, rust inhibitor, film-forming agent, acidic phosphate ester, N-oleoylsarcosine and sodium dioctyl sulfosuccinate, and stir until homogeneous to obtain a long-lasting salt spray rust-preventive oil.

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