Water-soluble antirust liquid composition and application method thereof

Abstract

The invention relates to a water-soluble antirust liquid composition and an application method thereof, and belongs to the technical field of metal rust prevention. The composition comprises the following components in percentage by mass: 50%-90% of mineral oil, 5%-20% of mahogany petroleum sulfonate, 5%-20% of an anti-rust additive, 5%-20% of a surfactant and 0.01%-0.5% of a defoaming agent. The composition can be diluted with water according to the volume ratio of 1: 1-50: 1, and then a metal workpiece is immersed for 1-30 seconds at the temperature of 25-40 DEG C, so that a compact and uniform anti-rust film is formed. The problems that a traditional water-soluble antirust liquid is poor in film-forming property and uneven in film layer at low temperature are solved, and the antirust liquid has the advantages of being environmentally friendly, low in toxicity, easy to clean and the like and is suitable for machining, cleaning and storing procedures of multiple kinds of metal such as steel, aluminum and copper.

Description

Technical Field

[0001] This invention belongs to the field of metal rust prevention technology, specifically relating to a water-soluble rust-preventive liquid composition and its application method. More specifically, this invention provides a rust-preventive liquid composition that, although a water-soluble system, can form a dense and uniform rust-preventive film on metal surfaces. This rust-preventive film can form stably even at relatively low temperatures (e.g., 25°C to 40°C) and exhibits excellent corrosion resistance and water resistance. This invention can be widely applied in the processing, cleaning, and storage of various metal materials such as steel, aluminum, and copper, belonging to a technical field that combines an environmentally friendly water-soluble formula with excellent rust-preventive performance. Background Technology

[0002] Metal products are prone to corrosion during manufacturing, processing, transportation, and storage due to reactions with moisture, oxygen, and salt in the air. This not only affects the product's appearance but also reduces its mechanical properties and service life. Traditionally, rust-preventive oils are used to prevent corrosion. These oils are typically composed of solvents, mineral oils, and rust-inhibiting additives. After being applied to the metal surface, the solvent evaporates rapidly, forming an oil film that blocks external moisture and oxygen, thus achieving a rust-preventive effect. However, these solvent-based products have significant drawbacks: firstly, the solvents pose a potential hazard to human health, and long-term exposure may lead to health problems; secondly, solvent evaporation causes environmental pollution and deteriorates the working environment; and thirdly, additional cleaning procedures are often required after use, increasing costs and operational complexity.

[0003] To overcome the aforementioned problems, water-soluble or emulsified rust inhibitors have been gradually developed and widely used in recent years. Water-soluble rust inhibitors do not use organic solvents and have the advantages of being environmentally friendly, low-toxicity, and easy to clean. However, their main drawback is the poor density of the rust-preventive film, and because they are water-based, they are more sensitive to temperature. Under low-temperature conditions (such as 25℃~40℃), water-soluble rust inhibitors are difficult to form a sufficient rust-preventive effect, and the residual film after drying is often uneven, which can easily lead to localized corrosion during long-term storage. For example, existing water-soluble rust inhibitors often rely on high-temperature drying or special additives to improve film formation, but this increases energy consumption and cost, and is not feasible in some field applications.

[0004] Furthermore, some water-soluble rust inhibitor formulations disclosed in the prior art suffer from poor component compatibility and unstable film-forming performance. For example, Chinese patent CN103013244B discloses a water-soluble rust inhibitor that uses a composite of a polymeric film-forming agent and a rust inhibitor, but this formulation exhibits slow film-forming speed at low temperatures and the film is prone to cracking. Another patent, CN108754500A, discloses a water-based metal rust inhibitor that emphasizes the use of special emulsifiers to improve stability, but its rust-preventive durability is insufficient, especially in humid environments where it is prone to failure. In addition, these prior arts often neglect the synergistic effect between the components, leading to a decline in the performance of the rust-preventive film under complex working conditions (such as temperature changes and mechanical friction).

[0005] Therefore, there is an urgent need in the field for a technology that, while being an environmentally friendly water-soluble system, can still form a dense and uniform anti-rust film on metal surfaces and maintain film stability at relatively low temperatures. Especially valuable is a technology that exhibits excellent anti-rust performance without high-temperature drying after metal processing and cleaning, making it highly valuable for industrial applications. This invention addresses these problems by optimizing the formulation and application method to achieve the goal of forming a stable and dense anti-rust film at low temperatures. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a water-soluble rust inhibitor composition that can be diluted with water and its application method. This product is environmentally friendly and user-friendly, and can improve the density and adhesion of the rust inhibitor film. It can stably form a rust inhibitor film even under low temperature conditions, thereby achieving a long-term rust prevention effect.

[0007] The above-mentioned objective of this invention is achieved through the following technical solutions: In a first aspect, the present invention provides a water-soluble rust-preventive liquid composition comprising the following components by mass percentage: 50%–90% mineral oil, 5%–20% petroleum sulfonate, 5%–20% rust-preventive additive, 5%–20% surfactant, and 0.01%–0.5% defoamer. The components work synergistically within the above-mentioned ranges to ensure that the composition, after dilution with water, can form a uniform and dense rust-preventive film on the metal surface.

[0008] As a further technical solution of the present invention: the viscosity of the mineral oil is 8-100 cSt (@40℃), and it is a naphthenic or paraffinic mineral oil. Low viscosity mineral oil (e.g., 15-30 cSt) helps to improve emulsification stability and film uniformity.

[0009] As a further technical solution of the present invention: the molecular weight of the petroleum sulfonate is 100-1000, and it can be selected from one or more of alkylbenzene sulfonates, alkylnaphthalene sulfonates, petroleum sulfonates, polyalkyl sulfonates, alkyltoluene sulfonates, linear alkylbenzene sulfonates (LAS), and natural or synthetic alkylaryl sulfonates. These components not only act as polar adsorbents on metal surfaces, but also serve as emulsifying stabilizers and corrosion inhibitors.

[0010] As a further technical solution of the present invention: the rust-inhibiting additive is selected from one or more of the following: calcium petroleum sulfonate, barium petroleum sulfonate, fatty acids with 6 to 30 carbon atoms, sulfonic acids with 6 to 30 carbon atoms, aminosulfonic acids with 6 to 30 carbon atoms, and their amine neutralization products and complexes. The amine in the amine neutralization product can be selected from triethanolamine, monoethanolamine, isopropanolamine, diethylene glycolamine, dicyclohexylamine, methylpropanolamine, etc., and these amines can improve the metal adhesion and water solubility of the rust-inhibiting additive.

[0011] As a further technical solution of the present invention: the surfactant has an HLB value of 3 to 20, a carbon number of 6 to 30, and is a nonionic or anionic surfactant, such as alkyl alcohol polyoxyethylene ether, nonylphenol polyoxyethylene ether, fatty acid monoglyceride, etc., to improve the compatibility between the aqueous phase and the oil phase and the coating uniformity.

[0012] As a further technical solution of the present invention: the defoamer is selected from one or more of silicone-based, non-silicone-based, alcohol-based or amine-based defoamers, such as polydimethylsiloxane and silica-based defoamers, and is used to suppress the generation of bubbles during mixing and coating processes.

[0013] Secondly, this invention provides a method for applying the above-mentioned water-soluble rust inhibitor composition, comprising the following steps: diluting the composition with water at a volume ratio of 1:1 to 50:1 to obtain a diluted solution; immersing the metal workpiece to be treated in the diluted solution at a temperature of 25°C to 40°C for 1 to 30 seconds; removing the metal workpiece and allowing it to air dry or dry at a low temperature to form a rust-preventive film. Deionized water is preferred for dilution, but tap water or groundwater can also be used. This method is applicable to various metal workpieces such as steel, aluminum, and copper, and is simple to operate without the need for high-temperature treatment.

[0014] Furthermore, the present invention also provides an optional electrochemical-assisted application method, wherein a weak current (e.g., 0.1-1.0 A / m²) is applied during the impregnation step to promote the formation and densification of the anti-rust film. This method is particularly suitable for high-precision metal parts and can further improve the adhesion and uniformity of the anti-rust film.

[0015] Furthermore, this invention also covers applications such as spraying, brushing, or roller coating, wherein the diluent can be applied to the metal surface using conventional spraying equipment, and the application time can be adjusted according to the shape of the workpiece, but is preferably completed within 1-60 seconds. These variant methods expand the scope of application of this invention to large or complex structural workpieces.

[0016] The core innovation of this invention lies in the synergistic mechanism among its components: mineral oil serves as the film-forming base, providing a physical barrier; petroleum sulfonates form a primary protective layer on the metal surface through polar adsorption; rust inhibitors enhance corrosion resistance through chemical adsorption and hydrophobic interactions; surfactants ensure uniform dispersion and emulsification stability of each component; and defoamers prevent film defects caused by air bubbles. This multi-component synergistic system can still rapidly form a dense film at low temperatures, overcoming the film-forming bottleneck of traditional water-soluble rust inhibitors.

[0017] In summary, compared with the prior art, the present invention has at least one of the following beneficial technical effects: Environmental friendliness: The composition is a water-soluble system and does not contain organic solvents, which reduces harm to the environment and human health.

[0018] Low-temperature film-forming properties: By immersion treatment at 25℃~40℃, a dense and uniform anti-rust film can be formed on the metal surface, solving the problem of poor film-forming properties of traditional water-soluble anti-rust liquids at low temperatures.

[0019] Synergistic effect: The components such as mineral oil, petroleum sulfonates, rust inhibitors and surfactants work together to enhance the adhesion, water resistance and corrosion resistance of the film.

[0020] Wide applicability: Applicable to a variety of metal materials and industrial processes, such as processing, cleaning and storage, and has high practical value.

[0021] Long-term rust prevention performance: Accelerated aging tests and actual storage tests have proven that the rust-preventive film of this invention can still effectively inhibit corrosion within 30-90 days, which is superior to similar products on the market.

[0022] Easy to clean: The rust-preventive film can be easily removed with conventional alkaline or neutral cleaning agents without leaving any residue, making it suitable for metal workpieces that require further processing.

[0023] Economic efficiency: Since no high-temperature drying or special equipment is required, this invention reduces energy consumption and operating costs, making it suitable for large-scale industrial applications. Detailed Implementation

[0024] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the embodiments of this application. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0025] The water-soluble rust inhibitor of the present invention comprises the following core components, and the functions and preferred ranges of each component are as follows: (a) Base Oil: The base oil serves as the main carrier of the components, providing lubrication and a film-forming basis. In this invention, the base oil is preferably a mineral oil system, a synthetic oil system, or a mixture thereof, such as low-viscosity mineral oil, paraffinic base oil, naphthenic base oil, polyalphaolefin (PAO), isoparaffin, polyethylene glycol, polyalkylene glycol (PAG), ester synthetic oil, polyol ester, glycerol trioleate, polydimethylsiloxane, etc. The viscosity of the base oil is preferably 10–100 cSt (@40°C), preferably a low-viscosity oil of 15–30 cSt, to ensure emulsification stability and film uniformity. The mass ratio of mineral oil ranges from 50% to 90%. If it is less than 50%, the film is too thin and the rust prevention effect is insufficient; if it is more than 90%, the proportion of other components is limited, affecting the overall performance.

[0026] Furthermore, the selection of base oils also considers their aniline point, preferably mineral oils with an aniline point of 60-100°C, to ensure compatibility with other components and low-temperature fluidity. For example, high aniline point oils (>90°C) are suitable for high-temperature environments, while low aniline point oils (<70°C) are more conducive to low-temperature film formation. The pour point of the base oil is preferably below -10°C to ensure good fluidity and workability in winter or low-temperature environments.

[0027] (b) Petroleum sulfonates: Petroleum sulfonates play multiple roles in the composition: as polar adsorbents on metal surfaces, forming adsorbent protective films; as emulsion stabilizers, improving oil-water compatibility; and simultaneously possessing corrosion inhibitor functions. The molecular weight of petroleum sulfonates is 100–1000, and they can be selected from one or more of alkylbenzene sulfonates, alkylnaphthalene sulfonates, petroleum sulfonates, polyalkyl sulfonates, alkyltoluene sulfonates, linear alkylbenzene sulfonates (LAS), and natural or synthetic alkylaryl sulfonates. Preferably, these compounds can be used alone or in combination of two or more, and their hydrocarbon chains have a carbon number of C8–C9. 25 C is preferred 12 ~C 20Petroleum sulfonates can be derived not only from natural petroleum fractions but also from synthetic alkylaryl sulfonic acids, products obtained from the sulfidation of medium and heavy oil products, and polyisobutylene sulfonates. Petroleum sulfonates can exist in the form of metal salts, such as sodium, potassium, calcium, magnesium, barium, or amine salts (e.g., triethanolamine and diethanolamine). Commercial products such as Petronate HL, Petronate CA, Witconate series, Gardinol series, Nacconol, Hostapur, Aerosol OT, and DDBSA (dodecylbenzene sulfonic acid) derivatives are all available. The mass ratio of petroleum sulfonates ranges from 5% to 20%; too low a ratio results in insufficient adsorption and emulsification, while too high a ratio may lead to an overly viscous system. In water-soluble or emulsified rust inhibitor compositions, these petroleum sulfonates can act as polar adsorbents on metal surfaces, serving as emulsion stabilizers, and simultaneously possessing the dual functions of corrosion inhibitors and surfactants.

[0028] The molecular structure of petroleum sulfonates significantly affects their performance. For example, linear alkylbenzene sulfonates (LAS) exhibit good biodegradability, while branched structures provide stronger adsorption. This invention optimizes the coverage and film density of petroleum sulfonates on metal surfaces by controlling the chain length and branching degree. Preferably, the mass ratio of linear to branched structures in the petroleum sulfonate is 1:5 to 5:1, more preferably 1:2 to 2:1, to achieve a balance between adsorption strength and environmental friendliness.

[0029] (c) Rust inhibitors: The rust inhibitors inhibit the corrosion process by imparting affinity and hydrophobicity to the metal surface, and achieve long-term rust prevention by blocking the direct contact between the metal and moisture, oxygen and salt.

[0030] Rust inhibitors may include, for example, one or more selected from petroleum-based or synthetic sulfonates, fatty acid salts, aminosulfonates, carboxylates, phosphate esters, alkylphenol derivatives, and complexes thereof. More specifically, the rust inhibitor may include one or more of the following groups of compounds: Metal sulfonates: Calcium petroleum sulfonate, barium petroleum sulfonate, magnesium petroleum sulfonate, sodium petroleum sulfonate, potassium petroleum sulfonate, zinc petroleum sulfonate, and ammonium petroleum sulfonate (these can exist in the form of metal salts or organic salts obtained from petroleum sulfonic acid, alkylbenzene sulfonic acid, alkylnaphthalene sulfonic acid, etc.).

[0031] Fatty acids and their salts: Saturated or unsaturated fatty acids with 6 to 30 carbon atoms (such as caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, etc.) and their amine salts.

[0032] Sulfonic acids and aminosulfonic acids: Alkyl sulfonic acids, alkylbenzene sulfonic acids, alkylnaphthalene sulfonic acids, and alkyltoluene sulfonic acids with 6 to 30 carbon atoms. And their amine salts, alkylammonium salts, calcium salts, barium salts, magnesium salts, etc. In addition, aromatic sulfonamide compounds may also be included, such as 6-(4-Methylphenylsulfonamido)hexanoic acid, 4-dodecylbenzenesulfonamide octanoic acid, etc.

[0033] Composite rust inhibitor: Mixed salts of sulfonic acids and fatty acids, complex salts of sulfonic acids and phosphate esters, mixtures of sulfonic acids and carboxylic acids, or chelated complexes of sulfonamide compounds and metal salts.

[0034] Other functional rust prevention systems: Alkylphenol derivatives, alkyl resorcinols, alkyl catechols, naphthol derivatives Alkyl phosphates are associated with phosphonates, aminocarboxylic acids, imidazoles, triazoles, benzotriazoles, toluenetriazoles, methylbenzotriazoles, etc.

[0035] The above-mentioned rust inhibitors can be used alone or in combination of two or more. Its total content can be controlled within 0.5 to 20 wt% of the whole composition, preferably within the range of 1 to 10 wt%.

[0036] Furthermore, the rust-inhibiting additive can improve the water resistance and corrosion resistance of the film by simultaneously forming a physical adsorption layer and a chemical reaction layer on the metal surface, and can also produce a synergistic effect with other surfactants or amines.

[0037] To further enhance rust prevention performance, this invention also introduces nano-rust-preventive fillers, such as nano-silica, nano-zinc oxide, or nano-clay, with a particle size range of 10-100 nm and an addition amount of 0.1-5%. These nano-fillers can fill the micropores of the film layer, enhancing its density and mechanical strength. The nano-fillers are preferably surface-modified, for example, treated with silane coupling agents (such as KH-550, KH-560) to improve their dispersibility in oil-water systems and their adhesion to the rust-preventive film substrate.

[0038] (d) Amines: Amines act as neutralizing agents or synergists, forming amine salts with rust inhibitors to enhance their performance. Usable amines include hydroxyl-containing amines (such as monoethanolamine, triethanolamine, monoisopropanolamine, diethylene glycolamine, etc.) and non-hydroxyl-containing amines (such as morpholine, cyclohexylamine, dicyclohexylamine, ethylenediamine, etc.). The amount of amines added can be adjusted according to the proportion of rust inhibitors, typically accounting for 0.5% to 10% of the composition.

[0039] The selection of amines also considers their pKa value and volatility. For example, triethanolamine (pKa ≈ 7.8) is suitable for neutral to weakly basic systems, while low-volatility amines (such as dicyclohexylamine) are beneficial for long-term rust prevention. This invention optimizes the stability and rust-preventive effect of amine salts by controlling the molar ratio of amines to rust-inhibiting additives (preferably 1:1 to 1:3). Particularly preferred is the use of a mixture of triethanolamine and dicyclohexylamine at a mass ratio of 1:1 to 4:1 to balance rapid film formation and long-term rust prevention.

[0040] (e) Surfactants: Surfactants are used to improve the compatibility between the aqueous and oil phases and to ensure uniform coating of the anti-rust film. Preferred surfactants are nonionic and anionic surfactants with an HLB value of 3–20 and a carbon number of 6–30, such as alkyl alcohol polyoxyethylene ethers (EO 2–20 mol), nonylphenol polyoxyethylene ethers, fatty acid monoglycerides, sorbitan esters (Span series), and polyoxyethylene sorbitan esters (Tween series). The mass ratio of surfactant should be 5%–20%; too low a ratio will result in poor emulsification, while too high a ratio may introduce excessive air bubbles.

[0041] The dynamic surface tension (DST) of the surfactant is also a key parameter. This invention preferably uses surfactants with a DST value below 40 mN / m (@1 Hz) to ensure rapid spreading and film formation. Furthermore, composite surfactant systems (such as nonionic and anionic formulations) can further improve emulsion stability and low-temperature performance. The preferred nonionic surfactant is C12-15 alcohol polyoxyethylene ether (EO=7), and the preferred anionic surfactant is sodium dodecylbenzenesulfonate, with a preferred mass ratio of 2:1 to 5:1.

[0042] (f) Defoamer: The defoamer is used to suppress bubbles generated during mixing and coating. It can be selected from one or more of the following: polydimethylsiloxane-based, silica-based, polyether-based, fatty acid ester-based, alkyl alcohol-based, and amide-based defoamers. Commercial products such as Lubrizol 5674, BYK-066N, and TegoFoam series can be used. The mass ratio of defoamer is in the range of 0.01% to 0.5%. If the ratio is too low, the defoaming effect will be insufficient; if it is too high, it may affect the film performance.

[0043] The method of adding the defoamer also affects performance. This invention recommends pre-dispersing the defoamer in a portion of the base oil before adding it to the system to improve dispersion efficiency and defoaming persistence. Polyether-modified polysiloxane defoamers are preferred, as they have better compatibility with the system described in this invention and are less likely to cause film defects.

[0044] Application method: Dilute the above components with water at a volume ratio of 1:1 to 50:1. Deionized water is preferred for dilution, but tap water or groundwater can also be used. Maintain the temperature of the diluted solution between 25℃ and 40℃. Immerse the metal workpiece in the solution for 1 to 30 seconds, then remove it and allow it to air dry or dry at a low temperature to form a rust-preventive film. This method is suitable for various metals such as steel, aluminum, and copper, requires no high-temperature treatment, and is easy to operate.

[0045] For workpieces with special shapes, ultrasonic-assisted impregnation can be used, with an ultrasonic frequency of 20-40 kHz and a duration of 5-15 seconds, to enhance the uniformity and adhesion of the film. In the drying step, natural drying is suitable for room temperature environments, while low-temperature drying (such as 40-60℃ hot air) can shorten the drying time to 1-5 minutes, suitable for assembly line operations. The thickness of the dried anti-rust film is preferably 0.5-5 μm, within which the anti-rust effect is guaranteed without adversely affecting subsequent processing.

[0046] Example: The present invention is further illustrated below with reference to specific embodiments, but the present invention is not limited to these embodiments. The formulations of each embodiment are expressed as a percentage by mass, and the test methods are as follows: Emulsion stability: Dilute the rust inhibitor with deionized water at a volume ratio of 20%, let it stand for 24 hours, and observe whether it separates into layers.

[0047] Rust prevention performance: Immerse the polished rolled steel plate in the diluted solution for 10 seconds, dry it at room temperature for 6 hours, and then place it in a humidification chamber at 30℃ and 90% humidity for 7 days to observe and record the rust condition.

[0048] Salt spray test: According to ASTM B117 standard, the treated steel plate is placed in a salt spray chamber (5% NaCl solution, 35°C), and the time when corrosion appears is recorded.

[0049] Film thickness measurement: The thickness of the anti-rust film is measured using an eddy current thickness gauge, with a preferred range of 0.5-5 μm.

[0050] Adhesion test: The cross-cut adhesion test is performed according to ASTM D3359 standard to evaluate the adhesion level of the film layer.

[0051] Long-term storage test: Place the treated workpiece in an indoor environment (temperature 15-35℃, humidity 40-80%) and observe the corrosion regularly.

[0052] Electrochemical testing: The corrosion resistance of the anti-rust film is evaluated by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization curves. Preferably, in a 3.5% NaCl solution, the charge transfer resistance (Rct) of the metal sample treated by this invention should be greater than 1×10^5 Ω·cm², and the corrosion current density (Icorr) should be less than 1×10^-7 A / cm².

[0053] Example 1: Base oil (viscosity 20 cSt, aniline point 70℃): 63.9%; Petronate H (petroleum sulfonate): 10%; Triethanolamine: 8%; Oleic acid: 3%; Rust-inhibiting compound agent 1:5%; Nonionic surfactant: 10%; Defoamer: 0.1%.

[0054] Test results: The emulsification stability was stable, and no rust was observed after 7 days of rust prevention testing in the humidification chamber.

[0055] Example 2: Base oil (viscosity 20 cSt, aniline point 70℃): 63.9%; Petronate HL (petroleum sulfonate): 10%; Monoethanolamine: 8%; Erucic acid: 3%; Rust-inhibiting composite agent 2:5%; Nonionic surfactant: 10%; Defoamer: 0.1%.

[0056] Test results: The emulsification stability was stable, and no rust was observed after 7 days of rust prevention testing in the humidification chamber.

[0057] Example 3: Base oil (viscosity 20 cSt, aniline point 70℃): 60.9%; Petronate H: 15%; Triethanolamine: 8%; Oleic acid: 3%; Rust-inhibiting compound agent 1:3%; Nonionic surfactant: 10%; Defoamer: 0.1%.

[0058] Test results: The emulsification stability was stable, and no rust was observed after 7 days of rust prevention testing in the humidification chamber.

[0059] Example 4: Base oil (viscosity 20 cSt, aniline point 70℃): 60.9%; Petronate HL: 15%; Monoethanolamine: 8%; Erucic acid: 3%; Rust-inhibiting composite agent 2:3%; Nonionic surfactant: 10%; Defoamer: 0.1%.

[0060] Test results: The emulsification stability was stable, and no rust was observed after 7 days of rust prevention testing in the humidification chamber.

[0061] Example 5: Base oil (viscosity 20 cSt, aniline point 70℃): 61.9%; Petronate H: 10%; Triethanolamine: 10%; Oleic acid: 5%; Rust-inhibiting compound agent 1:3%; Nonionic surfactant: 10%; Defoamer: 0.1%.

[0062] Test results: The emulsification stability was stable, and no rust was observed after 7 days of rust prevention testing in the humidification chamber.

[0063] Example 6: Base oil (viscosity 20 cSt, aniline point 70℃): 61.9%; Petronate HL: 10%; Monoethanolamine: 10%; Erucic acid: 5%; Rust-inhibiting composite agent 2:3%; Nonionic surfactant: 20%; Defoamer: 0.1%.

[0064] Test results: The emulsification stability was stable, and no rust was observed after 7 days of rust prevention testing in the humidification chamber.

[0065] Example 7: Base oil (viscosity 30 cSt, aniline point 80℃): 70%; Petronate H: 8%; Triethanolamine: 5%; Oleic acid: 2%; Rust-inhibiting compound agent 1:3%; Nonionic surfactant: 10%; Nano-silica (particle size 20 nm): 1%; Defoamer: 0.1%.

[0066] Test results: The emulsion stability was stable, no rust was observed in the humidification chamber rust prevention test after 7 days, and no rust was observed in the salt spray test after 72 hours. The film thickness was 1.2 μm, and the adhesion grade was 5B.

[0067] Example 8: Base oil (viscosity 15 cSt, aniline point 65℃): 55%; Petronate HL: 12%; Monoethanolamine: 6%; Erucic acid: 4%; Rust-inhibiting composite agent 2:5%; Nonionic surfactant: 15%; Defoamer: 0.1%; Deionized water: 2.9% (as a pre-diluent).

[0068] Test results: The emulsion stability was stable, no rust was observed in the humidification chamber rust prevention test after 7 days, and no rust was observed in the salt spray test after 96 hours. The film thickness was 0.8 μm, and the adhesion grade was 5B.

[0069] Example 9: Base oil (viscosity 25 cSt, aniline point 75℃): 68%; Petronate H: 10%; Triethanolamine: 7%; Oleic acid: 3%; Rust-inhibiting composite agent 1:4%; Nonionic surfactant: 7%; Defoamer: 0.1%; Nano zinc oxide (particle size 50 nm): 0.9%.

[0070] Test results: The emulsion stability was stable, no rust was observed after 7 days of rust prevention test in the humidification chamber, and no rust was observed after 120 hours of salt spray test. The film thickness was 1.5 μm, and the adhesion grade was 4B.

[0071] Example 10: Base oil (viscosity 20 cSt, aniline point 70℃): 60%; Petronate HL: 15%; Monoethanolamine: 8%; Erucic acid: 3%; Rust-inhibiting composite agent 2:3%; Nonionic surfactant: 10%; Defoamer: 0.1%; Ultrasound-assisted application: frequency 30 kHz, duration 10 seconds.

[0072] Test results: The emulsion stability was stable, no rust was observed in the humidification chamber rust prevention test after 7 days, and no rust was observed in the salt spray test after 144 hours. The film thickness was 1.0 μm, and the adhesion grade was 5B.

[0073]

[0074] * Using deionized water, the rust inhibitor was prepared into a diluted solution at a volume ratio of 20%. The polished rolled steel plate was immersed in the diluted solution for 10 seconds and then dried at room temperature for 6 hours for the experiment.

[0075] Comparative Example: To compare the effectiveness of this invention, the same test was conducted using a traditional water-soluble rust inhibitor (containing no petroleum sulfonates and with a low proportion of rust inhibitor additives). Results: Poor emulsification stability; separation occurred after standing; rust appeared after 3 days in the humidification chamber rust prevention test. This indicates that the composition of this invention has significant advantages in low-temperature film-forming properties and rust prevention performance.

[0076] Furthermore, compared with commercially available products (such as a certain brand of water-based rust inhibitor), Examples 1-10 of the present invention show superior performance in salt spray testing, film thickness uniformity, and adhesion. For example, commercially available products only achieve 24-48 hours in salt spray testing, while most examples of the present invention exceed 72 hours. The table below shows a comprehensive performance comparison between Example 7 of the present invention and two mainstream commercially available products (Product A: solvent-based rust inhibitor; Product B: a certain water-based rust inhibitor):

[0077] Note: Although solvent-based product A has some good performance characteristics, it is not environmentally friendly and safe.

[0078] Industrial Applications: The components of this invention have been tested in actual production for cleaning and rust prevention of steel parts. Results show that treated workpieces showed no rust within 30 days of storage, and the cleaning process is simple and environmentally friendly.

[0079] Expanding industrial application examples: Case 1: Rust Prevention for Automotive Parts. An automotive parts factory used the formula of Example 1 of this invention to treat transmission gears, immersing them for 15 seconds, and then storing them in an outdoor warehouse (humidity 70-90%) after drying. After 60 days, no rust was found, and no additional cleaning was required before subsequent assembly.

[0080] Case 2: Aluminum Profile Processing. An aluminum factory used the formula in Example 5 to apply the coating to the surface of aluminum profiles via spraying. After natural drying, a uniform film layer was formed. No corrosion was observed after 96 hours of salt spray testing, and the coating did not affect subsequent anodizing treatment.

[0081] Case 3: Copper Wire Storage. A cable factory treated copper wire coils using the formula in Example 8, followed by low-temperature drying (50°C). After storage in a humid warehouse for 90 days, there was no oxidation or discoloration, and the conductivity was unaffected.

[0082] Case 4: Large steel structural components. A bridge manufacturing company used the formulation of Example 10, combined with ultrasonic-assisted application, to treat welded joints and riveted areas. After 30 days of exposure in a marine atmospheric environment (high salinity), no localized corrosion was observed, and the anti-rust film remained intact.

[0083] Case 5: Precision Instrument Components. An instrument company used the formula from Example 7 and employed an electrochemical-assisted method (0.5 A / m²) to treat precision copper alloy contacts. After treatment, the contact resistance remained stable, and no corrosion was observed after 180 days of storage in a constant temperature and humidity chamber, meeting high reliability requirements.

[0084] In summary, this invention achieves highly efficient rust prevention of water-soluble rust inhibitors at low temperatures by optimizing the formulation and application method, and has broad application prospects.

[0085] The principle of this invention is as follows: This invention relates to a water-soluble rust inhibitor composition and its application method, belonging to the field of metal rust prevention technology. The composition includes 50%–90% mineral oil, 5%–20% petroleum sulfonate, 5%–20% rust inhibitor additives, 5%–20% surfactants, and 0.01%–0.5% defoamer by mass ratio. This composition can be diluted with water at a volume ratio of 1:1 to 50:1, and then the metal workpiece can be immersed at 25℃–40℃ for 1–30 seconds to form a dense and uniform rust-preventive film. This invention solves the problems of poor film formation and uneven film layer in traditional water-soluble rust inhibitors at low temperatures, and has advantages such as environmental friendliness, low toxicity, and easy cleaning. It is suitable for the processing, cleaning, and storage of various metals such as steel, aluminum, and copper.

[0086] The technical solution of this invention has been fully verified through the above embodiments. Its component selection, proportion range, and application method have all undergone extensive experimental optimization, ensuring repeatability and industrial feasibility. Those skilled in the art can adjust the specific formulation according to the content of this invention without departing from the core protection scope of this invention.

[0087] The embodiments described herein are preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape, and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A water-soluble rust inhibitor composition, characterized in that, consisting of: mineral oil: 50% to 90%; petroleum sulfonate: 5% to 20%; antirust additive: 5% to 20%; surfactant: 5% to 20%; antifoaming agent: 0.01% to 0.5%. The mineral oil has a viscosity of 8 to 100 cSt and is a naphthenic or paraffinic mineral oil.

2. The water-soluble rust preventive liquid composition according to claim 1, wherein The petroleum sulfonate has a molecular weight of 100 to 1000 and is selected from one or more of alkyl benzene sulfonate, alkyl naphthalene sulfonate, petroleum sulfonate, polyalkyl sulfonate, alkyl toluene sulfonate, linear alkyl benzene sulfonate, natural or synthetic alkyl aryl sulfonate.

3. The water-soluble rust preventive liquid composition according to claim 1, wherein The antirust additive is selected from one or more of calcium petroleum sulfonate, barium petroleum sulfonate, fatty acid having a carbon number of 6 to 30, sulfonic acid having a carbon number of 6 to 30, aminosulfonic acid having a carbon number of 6 to 30, and amine neutralization and complex thereof.

4. The water-soluble rust preventive liquid composition according to claim 1, wherein The amine in the amine neutralization is selected from one or more of triethanolamine, monoethanolamine, isopropanolamine, diglycolamine, dicyclohexylamine, and methylpropanolamine.

5. The water-soluble rust preventive liquid composition according to claim 4, wherein The surfactant has an HLB value of 3 to 20, a carbon number of 6 to 30, and is a nonionic or anionic surfactant.

6. The water-soluble rust preventive liquid composition according to claim 1, wherein The antifoaming agent is selected from one or more of silicon-based, non-silicon-based, alcohol-based, or amine-based antifoaming agents.

7. The water-soluble rust preventive liquid composition according to claim 1, wherein The method comprises the following steps:

8. The method of claim 1 to 7, wherein the water-soluble rust preventive liquid composition is applied to the surface of the metal material by spraying, dipping, or immersing the metal material in the water-soluble rust preventive liquid composition. diluting the water-soluble antirust liquid composition with water at a volume ratio of 1:1 to 50:1 to obtain a diluted solution; immersing the metal workpiece to be treated in the diluted solution at a temperature of 25°C to 40°C for 1 to 30 seconds; removing the metal workpiece and naturally or low-temperature drying to form an antirust film. The dilution water is deionized water, tap water, or underground water.

9. The method of claim 8, wherein the water-soluble rust preventive liquid composition is applied to the surface of the metal product in a form of a film having a thickness of 0.1 to 10 μm. The metal workpiece is made of steel, aluminum, or copper.

10. The method of claim 8, wherein the water-soluble rust preventive liquid composition is applied to the surface of the metal product in a form of a film having a thickness of 0.1 to 10 μm. ​

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