Water-based plugging coating with flash rust prevention function for passenger car

Abstract

The invention belongs to the technical field of water-based coatings, and relates to a water-based plugging coating with an anti-flash-rust function for a passenger car. The invention relates to a water-based cleaning agent which comprises the following components in parts by weight: 10-20 parts of Fischer-Tropsch wax, 15-20 parts of sulfonated lanolin cerium / lanthanum salt, 30-70 parts of water, 1-4 parts of phenanthrene formic acid dimethylethanolamine salt, 2 parts of terephthalic acid dihydrazide and 1-5 parts of acetoacetoxy ethyl methacrylate modified iso-tridecanol polyoxyethylene ether TO-8. The method mainly solves the problem of flash rust of the inner wall of a cavity when a water-based product is used at the automobile door cavity folding edge and other automobile body gaps, and solves the problem of corrosion in the long-term inward volatilization process of water in the automobile door folding edge gaps when a coating is thickly coated. The phenanthrene formic acid dimethylethanolamine salt with moderate vapor pressure is used for guaranteeing the emulsifying characteristic, meanwhile, the gas-phase corrosion inhibition function of the phenanthrene formic acid dimethylethanolamine salt prevents flash rust, and along with gradual volatilization of water and amine, self-crosslinking of keto carbonyl-hydrazide and the HLB value of a system are gradually reduced, so that the coating has better waterproofness in the initial drying stage, and the water resistance of the coating is greatly improved. Perfect water-based substitution is realized.

Description

A water-based sealing coating for passenger vehicles with anti-flash rust function Technical Field

[0001] This invention belongs to the field of water-based coating technology, and specifically relates to a water-based sealing coating for passenger vehicles with anti-flash rust function. Background Technology

[0002] In recent years, with the rapid development of China's automobile industry and the surge in automobile exports, the focus on rust prevention performance in gaps has become insufficient for domestically sold models. During maritime transport, the problem of penetrating rust in these gaps has become increasingly apparent. Traditionally, solvent-based rust-preventive waxes are mainly used to fill and seal gaps in cavities and bolt seams, addressing the inability to effectively coat the inner walls of these gaps during pretreatment and electrophoresis due to their poor penetration. However, solvent-based rust-preventive waxes suffer from numerous problems, including low flash point, strong odor, and high VOC emissions, making them unsuitable for use throughout the painting, assembly, and even repair processes. With technological advancements, water-based systems have gained increasing application. However, water-based systems inevitably require emulsifiers to maintain the dispersion of the oil phase in water, directly resulting in water-based waxes failing to achieve the same water resistance and corrosion resistance as solvent-based products. Examples include CN104789126B (Rust-preventive Emulsified Wax and its Preparation Method) and CN103173124B (Metal Rust-preventive Wax Based on Emulsified Wax and its Preparation Method). In addition, a more serious problem is that during the sealing process of water-based systems, moisture evaporates in both the internal and external phases, easily causing excessive humidity in the cavity in a short period of time, leading to flash rust and reducing the service life of the metal. At the same time, to improve the water resistance of water-based waxes, the common practice is to reduce the amount of emulsifier used, but this leads to unstable emulsion micelles, large emulsion particles that are prone to aggregation, resulting in a gradual increase in viscosity or, in severe cases, emulsion instability and stratification. Therefore, the stability and shelf life of water-based products are also among their main drawbacks. Thus, solving the flash rust prevention problem and the hydrophilicity of emulsifiers are the most significant obstacles to the application of water-based systems in automotive bodies. Summary of the Invention

[0003] To address the aforementioned technical problems, the purpose of this invention is to develop a water-based sealing coating for passenger vehicles with anti-flash rust function. This coating provides vapor phase rust prevention, significantly reduces the system's HLB content and hydrophilicity during the drying process, and exhibits good storage stability, thus replacing solvent-based products.

[0004] This invention utilizes phenanthrene acid and dimethylethanolamine to form a salt, giving it hydrophilicity while its polycyclic aromatic hydrocarbon structure helps emulsify other oil phase components. During film formation, as phenanthrene acid and dimethylethanolamine volatilize, not only is the system's HLB reduced, but a saturated vapor pressure is also created within the sealed cavity, forming a gas-phase corrosion-inhibiting atmosphere to prevent flash rust on the cavity wall. Simultaneously, phenanthrene acid also sublimates and volatilizes, providing a long-lasting sealing effect of 15-20 days. Finally, after the complete volatilization of phenanthrene acid and dimethylethanolamine, a stable hydrophobic film is formed.

[0005] The ketone carbonyl-hydrazide self-crosslinking emulsifier system used in this invention, namely isomeric tridecyl alcohol polyoxyethylene ether TO-8, has a terminal hydroxyl group. An acetoacetic acid group is grafted onto the terminal hydroxyl group (through an ester exchange reaction), without altering the hydrophilic and lipophilic structure of the polyether backbone, thus enabling the emulsifier to crosslink with diterephthalic acid hydrazide. During film formation, as water and amines gradually evaporate, the self-crosslinking of the ketone carbonyl-hydrazide group locks the hydrophilic group, preventing it from providing hydrophilic emulsification, thereby achieving the purpose of providing water resistance and salt spray resistance.

[0006] In order to provide better emulsion stability and better sealing effect for the system, this invention sulfonates lanolin, hydrophilizes it, and then forms a stable rust inhibitor with rare earth elements cerium and lanthanum.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is: a water-based sealing coating for passenger vehicles with anti-flash rust function, wherein the water-based sealing coating comprises, by weight, 10-20 parts Fischer-Tropsch wax, 15-20 parts sulfonated lanolin cerium / lanthanum salt, 30-70 parts water, 1-4 parts dimethyl ethanolamine phenanthreneate, 2 parts dihydrazide terephthalate, and 1-5 parts isomeric tridecyl alcohol polyoxyethylene ether TO-8 modified with ethyl acetoacetate; wherein the sulfonated lanolin cerium / lanthanum salt is prepared by adding cerium chloride / lanthanum chloride to potassium lanolinate to obtain lanolin cerium / lanthanum saponification, then adding trichloroethane and concentrated sulfuric acid for sulfonation to obtain sulfonated lanolin, and reacting with a mixed aqueous solution of cerium hydroxide / lanthanum hydroxide to obtain sulfonated lanolin cerium / lanthanum salt.

[0008] A water-based sealing coating for passenger vehicles with anti-flash rust function, wherein the water-based sealing coating comprises, by weight, 12 parts of Fischer-Tropsch wax, 18 parts of sulfonated lanolin cerium / lanthanum salt, 62.5 parts of water, 3.7 parts of dimethyl ethanolamine phenanthreneformate, 2 parts of dihydrazide terephthalate, and 1.8 parts of isomeric tridecyl alcohol polyoxyethylene ether TO-8 modified with ethyl acetoacetate methacrylate.

[0009] Furthermore, the above-mentioned water-based sealing coating for passenger vehicles with anti-flash rust function includes the following steps in the preparation method of sulfonated lanolin cerium / lanthanum salt: Pharmaceutical-grade lanolin is heated to 105℃ for 1 hour, and free small-molecule acids and alcohols are distilled off under negative pressure. The mixture is then cooled to 85℃ and added dropwise to a potassium hydroxide aqueous solution. After slow stirring for 6 hours, purified water is added and stirred for 1 hour, followed by standing for 6 hours. A potassium lanolinate suspension is then released from the bottom. A 10% mixed aqueous solution of cerium chloride / lanthanum chloride is added to the potassium lanolinate suspension, with a cerium / lanthanum molar ratio of 1:1, and the mixed aqueous solution is in excess. The mixture is slowly stirred at 40℃ for 3 hours, filtered, and washed with water to obtain cerium / lanthanum saponified lanolinate. Trichloroethane is added to the cerium / lanthanum saponified lanolinate, stirred evenly, and cooled to 5℃-10℃. 20% concentrated sulfuric acid is added dropwise, with the temperature controlled below 10℃ throughout. After 3 hours, purified water at 0-5℃ is added, and the mixture is allowed to stand and separate into layers. The upper oily layer—sulfonated lanolin—is then collected. A mixed aqueous solution of 10% cerium hydroxide / lanthanum hydroxide was added to the solution, and the mixture was reacted at 40°C for 2 hours. After washing with water, sulfonated lanolin cerium / lanthanum salt was obtained.

[0010] Furthermore, in the aforementioned water-based sealing coating for passenger vehicles with anti-flash rust function, the preparation process of the phenanthrenecarboxylic acid dimethylethanolamine salt is as follows: 1-phenanthrenecarboxylic acid is dissolved in n-butanol, heated to 40°C, excess dimethylethanolamine is added dropwise and reacted for 1 hour, and n-butanol and dimethylethanolamine are distilled off under vacuum to obtain phenanthrenecarboxylic acid dimethylethanolamine salt. Its 10% aqueous dispersion should have an HLB of 11-13 and a pH of 8.5-9.5.

[0011] Furthermore, the preparation process of the aforementioned water-based sealing coating for passenger vehicles with anti-flash rust function, specifically the isomeric tridecyl alcohol polyoxyethylene ether TO-8 modified with ethyl acetoacetate methacrylate, is as follows: TO-8 emulsion is added to a reaction vessel, heated to 105°C, and vacuum dehydrated for 1 hour to remove trace amounts of water. The dehydrated TO-8 is then cooled to 85°C, and hydroquinone monomethyl ether and ethyl acetoacetate methacrylate (AAEM) are added sequentially, stirred for 5 minutes, followed by the addition of tetrabutyl titanate, and stirred for 5 minutes. The temperature is then raised to 105°C. Vacuum pressure is applied, and the reaction is maintained at this temperature and pressure for 4 hours. The temperature is then lowered to 75-80°C, a small amount of pure water is added, and the mixture is stirred for 20 minutes. After dehydration and monomer removal, the mixture is filtered to obtain the isomeric tridecyl alcohol polyoxyethylene ether TO-8 modified with ethyl acetoacetate methacrylate. Its HLB value is 12.5-13, and the acetoacetate content is 0.48 mmol / g.

[0012] A water-based sealing coating for passenger vehicles with anti-flash rust function includes the following steps: Water is added to a container and heated to 60°C. Dihydrazide terephthalate is added until completely dissolved. Dimethyl ethanolamine phenanthreneformate is added and stirred until homogeneous. In a separate container, C80 Fischer-Tropsch wax and sulfonated lanolin cerium / lanthanum salt are added, heated to 80°C and stirred until homogeneous. Ethyl acetoacetate-modified isomeric tridecyl alcohol polyoxyethylene ether TO-8 is then added. The molten oil phase mixture is slowly poured into the aqueous phase solution while continuously stirring. After 20 minutes, the mixture is cooled to obtain the water-based crack sealing coating for passenger vehicles with anti-flash rust function of this invention.

[0013] A water-based sealing coating for passenger vehicles with anti-flash rust function has the following advantages compared with traditional technology: 1. The present invention provides vapor phase corrosion inhibition function. By utilizing the reasonable vapor pressure of phenanthrene acid and dimethylethanolamine salt, it has good water vapor corrosion resistance from the initial stage of film formation to 20 days. Moreover, phenanthrene acid and dimethylethanolamine salt are not locked in the film-forming material, but eventually sublimate and volatilize without residue, and will not have an adverse effect on the odor inside the vehicle.

[0014] 2. This invention utilizes the volatility and self-polymerizing emulsifier functions of phenanthrene acid and dimethylethanolamine salt for emulsification, leaving no residue and having no impact on the system's water resistance. Even in the initial stage of surface drying, the dimethylethanolamine evaporates rapidly, and phenanthrene acid, being a hydrophobic rust inhibitor, provides good initial water resistance. Furthermore, the ketone carbonyl-hydrazide self-crosslinking emulsifier system, specifically the isomeric tridecyl alcohol polyoxyethylene ether TO-8 modified with ethyl acetoacetate methacrylate, achieves this by gradually evaporating water and amines during film formation. The reaction with phthalic acid dihydrazide locks in the hydrophilic groups, preventing further hydrophilic emulsification and thus providing water resistance and salt spray resistance.

[0015] 3. The sulfonated lanolin cerium / lanthanum salt of the present invention utilizes the easily emulsifiable structure of the carboxyl groups of lanolin. Sulfonation appropriately enhances its hydrophilicity, allowing it to be stably emulsified and dispersed in the system, avoiding particle increase and viscosity rise caused by the fusion of oil phase micelles during high-temperature storage. Simultaneously, the cerium / lanthanum salt exhibits significantly better adsorption to metal substrates than calcium salts, thus significantly improving rust prevention. Attached Figure Description

[0016] Figure 1 is a performance graph of the vapor phase rust prevention of the water-based sealing coatings for passenger vehicles with anti-flash rust function prepared in Example 1 (a), Comparative Example 1 (b), Comparative Example 2 (c), Comparative Example 3 (d), and Comparative Example 4 (e).

[0017] Figure 2 is a performance graph of the vapor phase rust prevention of the water-based sealing coatings for passenger vehicles with anti-flash rust function prepared in Example 1 (a), Comparative Example 1 (b), Comparative Example 2 (c), Comparative Example 3 (d), and Comparative Example 4 (e) after consumption.

[0018] Figure 3 shows the effect of neutral salt spray test on the water-based sealing coatings for passenger cars with anti-flash rust function prepared in Example 1 (a), Comparative Example 1 (b), Comparative Example 2 (c), Comparative Example 3 (d), and Comparative Example 4 (e).

[0019] Figure 4 shows the storage stability of the water-based sealing coatings for passenger vehicles with anti-flash rust function prepared in Example 1 (a), Comparative Example 1 (b), Comparative Example 2 (c), Comparative Example 3 (d), and Comparative Example 4 (e).

[0020] Figure 5 shows the initial water resistance of the water-based sealing coatings for passenger vehicles with anti-flash rust function prepared in Example 1 (a), Comparative Example 1 (b), Comparative Example 2 (c), Comparative Example 3 (d), and Comparative Example 4 (e).

[0021] Figure 6 is a diagram showing the dry water resistance of the water-based sealing coatings for passenger vehicles with anti-flash rust function prepared in Example 1 (a), Comparative Example 1 (b), Comparative Example 2 (c), Comparative Example 3 (d), and Comparative Example 4 (e). Detailed Implementation

[0022] The present invention will now be described in detail with reference to the embodiments.

[0023] Example 1: A water-based sealing coating for passenger vehicles with anti-flash rust function.

[0024] (a) The formula composition is as follows.

[0025] The formula is as follows (by weight): 12g Fischer-Tropsch wax C80, 18g sulfonated lanolin cerium / lanthanum salt, 3.7g dimethyl ethanolamine phenanthreneate, 2g dihydrazide terephthalate, 1.8g isomeric tridecyl alcohol polyoxyethylene ether TO-8 modified with ethyl acetoacetate methacrylate, and 62.5g deionized water.

[0026] (ii) The preparation method is as follows.

[0027] 1. Preparation of sulfonated lanolin cerium / lanthanum salt.

[0028] 150g of pharmaceutical-grade lanolin (moisture content ≤0.5%) was heated to 105℃ and subjected to negative pressure for 1 hour to evaporate free small-molecule acids and alcohols. The mixture was then cooled to approximately 85℃, and 10% potassium hydroxide aqueous solution (10%) was added dropwise, totaling 165g. After continuous slow stirring for 6 hours, 500g of purified water was added and stirred for 1 hour, followed by standing for 6 hours. 615g of potassium lanolinate suspension was collected from the bottom, and the pH was adjusted to approximately 7 using hydrochloric acid.

[0029] 170 g of a 10% aqueous solution of cerium chloride / lanthanum chloride (cerium / lanthanum molar ratio 1:1) was added to a potassium lanolinate suspension. The mixture was slowly stirred at 40°C for 3 hours, filtered, and washed with water to obtain 90 g of cerium / lanthanum saponified lanolinate. 200 g of trichloroethane was added to the cerium / lanthanum saponified lanolinate, stirred until homogeneous, and cooled to 5-10°C. 36.4 g of 20% concentrated sulfuric acid was added dropwise, maintaining the temperature below 10°C throughout the process. After 3 hours, 365 g of pure water (0-5°C) was added, and the mixture was allowed to stand and separate into layers. 275 g of the upper oily layer—sulfonated lanolin—was collected. 80 g of a 10% aqueous solution of cerium hydroxide / lanthanum hydroxide (cerium hydroxide to lanthanum hydroxide mass ratio 1:1) was added to this layer. The mixture was reacted at 40°C for 2 hours, and after washing with water, sulfonated lanolin cerium / lanthanum salt was obtained.

[0030] 2. Preparation of dimethyl ethanolamine phenanthrenecarboxylic acid salt: 100g of 1-phenanthrenecarboxylic acid was dissolved in 150g of n-butanol, heated to 40℃, and 42g of dimethyl ethanolamine was added dropwise. The reaction was carried out for 1 hour. The n-butanol and dimethyl ethanolamine were distilled off under vacuum to obtain dimethyl ethanolamine phenanthrenecarboxylic acid salt. Its 10% solution has an HLB of 11-13 and a pH of 8.5-9.5.

[0031] 3. Preparation of isomeric tridecyl alcohol polyoxyethylene ether TO-8 modified with ethyl acetoacetate methacrylate: 100g of TO-8 was added to a reaction vessel, heated to 105℃, and vacuum dehydrated for 1 hour to remove trace amounts of water. The dehydrated TO-8 was then cooled to 85℃, and 0.01g of hydroquinone monomethyl ether and 20g of ethyl acetoacetate methacrylate (AAEM) were added sequentially. The mixture was stirred for 5 minutes, followed by the addition of 0.24g of tetrabutyl titanate, and stirred for 5 minutes. The temperature was then raised to 105℃. A vacuum was applied, and the reaction was maintained at this temperature and pressure for 4 hours. The temperature was then lowered to 75-80℃, a small amount of pure water was added, and the mixture was stirred for 20 minutes. After dehydration and monomer removal, the mixture was filtered to obtain isomeric tridecyl alcohol polyoxyethylene ether TO-8 modified with ethyl acetoacetate methacrylate. Its HLB value was 12.5-13, and the acetoacetate group content was 0.48 mmol / g.

[0032] 4. Preparation of a water-based sealing coating for passenger vehicles with anti-flash rust function: 62.5g of water was added to a container, heated to 60℃, and 2g of dihydrazide terephthalate was added until completely dissolved. Then, 3.7g of dimethyl ethanolamine phenanthreneate was added to obtain an aqueous phase solution. In another container, 12g of C80 Fischer-Tropsch wax and sulfonated lanolin cerium / lanthanum salt were added for 18 hours, heated to 80℃ and stirred until homogeneous. Then, 1.8g of isomeric tridecyl alcohol polyoxyethylene ether TO-8 modified with ethyl acetoacetate methacrylate was added to obtain an oil phase mixture. The molten oil phase mixture was slowly poured into the aqueous phase solution while continuously stirring. After 20 minutes, the mixture was cooled to obtain a water-based sealing coating for passenger vehicles with anti-flash rust function.

[0033] (III) Comparative analysis and performance testing.

[0034] 1. Comparative Example 1.

[0035] Sulfonated lanolin calcium soap was used instead of sulfonated lanolin cerium / lanthanum salt in Example 1, while other components and proportions remained unchanged.

[0036] 2. Comparative Example 2.

[0037] Isotridecyl alcohol polyoxyethylene ether TO-8 was used instead of the ethyl acetoacetate-modified isotridecyl alcohol polyoxyethylene ether TO-8 in Example 1, while other components and proportions remained unchanged.

[0038] 3. Comparative Example 3.

[0039] Ammonium benzoate was used to replace dimethyl ethanolamine phenanthrene benzoate in Example 1, while other components and proportions remained unchanged.

[0040] 4. Comparative Example 4.

[0041] Commercially available water-based cavity rust-preventing wax used by automobile OEMs.

[0042] Specific testing technical indicators are shown in Table 1: Table 1 Comparison of coating performance prepared in the examples and comparative examples

[0043] As shown in Table 1, Figure 1, and Figure 2, the samples with added dimethyl ethanolamine phenanthreneate exhibited excellent vapor-phase corrosion inhibition capabilities. While ammonium benzoate in the three comparative examples is also a vapor-phase corrosion inhibitor, its effect requires a large dosage. As a hydrophilic substance, large-scale addition in water-based protective products is impractical (leading to decreased water resistance and corrosion resistance), thus limiting its vapor-phase corrosion inhibition effect. Furthermore, ammonium benzoate has a high vapor pressure and poor persistence, resulting in the unsatisfactory effect shown in Figure 2. Commercially available water-based cavity wax products essentially lack vapor-phase corrosion inhibition properties.

[0044] As shown in Table 1 and Figure 3, the salt spray resistance of the embodiments of the present invention is better, 10 times that of traditional commercially available water-based cavity waxes. Furthermore, the sulfonated lanolin cerium / lanthanum salt has a 5 times higher salt spray resistance than the calcium salt. This is because the single metal soap structure of the sulfonated lanolin calcium salt has limited adsorption on the metal substrate and cannot achieve network-like layered adsorption. In Comparative Example 2, the isomeric tridecyl alcohol polyoxyethylene ether TO-8 with more hydrophilic groups also shows significantly lower salt spray resistance than the TO-8 with locked hydrophilic groups after curing.

[0045] As shown in Table 1 and Figure 4, the embodiments of the present invention exhibit better thermal storage stability compared to other comparative examples. In Comparative Example 1, the sulfonated lanolin calcium salt tends to increase viscosity and precipitate soap in low-viscosity systems, significantly impacting storage stability. In Comparative Example 3, the system is more balanced and stable primarily because phenanthrene-2-methylethanolamine salt is not only a vapor-phase corrosion inhibitor but also possesses good emulsifying properties of carboxylic acid ethanolamine salts.

[0046] As shown in Table 1, Figure 5, and Figure 6, in Comparative Example 2, the use of isomeric tridecyl alcohol polyoxyethylene ether TO-8 instead of the ethyl methacrylate-modified isomeric tridecyl alcohol polyoxyethylene ether TO-8 in Example 1 resulted in the lack of locking of hydrophilic groups during the drying process. This led to the absorption of hydrophilic groups by the emulsifier during the water-resistant period, causing the coating to turn white, a common problem with traditional water-based cavity waxes. In Comparative Example 3, the use of ammonium benzoate instead of dimethyl ethanolamine phenanthreneate in Example 1 resulted in poor initial water resistance due to the excessive hydrophilicity of ammonium benzoate. (The practical significance of initial water resistance lies mainly in effectively preventing back dissolution and avoiding the "white liquid overflowing from the drainage holes" caused by back dissolution of the coating during the enhanced rain test phase for different vehicle models.)

[0047] Comparative Example 4: The main problems with commercially available products are that flash rust is prone to occur during film drying, the coating is easily washed away causing runoff, and long-term use can easily lead to demulsification and stratification, resulting in pipeline blockage.

Claims

1. A water-based sealing coating for passenger vehicles with anti-flash rust function, characterized in that, The mixture, by weight, comprises 10-20 parts Fischer-Tropsch wax, 15-20 parts sulfonated lanolin cerium / lanthanum salt, 30-70 parts water, 1-4 parts dimethyl ethanolamine phenanthreneate, 2 parts dihydrazide terephthalate, and 1-5 parts isomeric tridecyl alcohol polyoxyethylene ether TO-8 modified with ethyl acetoacetate. The sulfonated lanolin cerium / lanthanum salt is prepared by adding cerium chloride / lanthanum chloride to potassium lanolinate to obtain lanolin cerium / lanthanum saponification, followed by sulfonation with trichloroethane and concentrated sulfuric acid to obtain sulfonated lanolin, and then reacting with a mixed aqueous solution of cerium hydroxide / lanthanum hydroxide to obtain sulfonated lanolin cerium / lanthanum salt.

2. The water-based sealing coating for passenger vehicles with anti-flash rust function according to claim 1, characterized in that, The formula, by weight, includes 12 parts Fischer-Tropsch wax, 18 parts sulfonated lanolin cerium / lanthanum salt, 62.5 parts water, 3.7 parts dimethyl ethanolamine phenanthrene ether, 2 parts dimethyl terephthalate dihydrazide, and 1.8 parts isomeric tridecyl alcohol polyoxyethylene ether TO-8 modified with ethyl acetoacetate methacrylate.

3. A water-based sealing coating for passenger vehicles with anti-flash rust function according to claim 1 or 2, characterized in that, The method for preparing sulfonated lanolin cerium / lanthanum salt includes the following steps: In a potassium lanolinate suspension, a 10% mixed aqueous solution of cerium chloride and lanthanum chloride is added, with a cerium / lanthanum molar ratio of 1:

1. The mixture is slowly stirred at 40°C for 3 hours, filtered, and washed with water to obtain lanolin cerium / lanthanum saponified product. Trichloroethane is added to the lanolin cerium / lanthanum saponified product, stirred evenly, and cooled to 5°C-10°C. 20% concentrated sulfuric acid is added dropwise for sulfonation, with the temperature controlled below 10°C throughout. After 3 hours, pure water at 0-5°C is added, and the mixture is allowed to stand and separate into layers. The upper oily layer – sulfonated lanolin – is taken, and a 10% mixed aqueous solution of cerium hydroxide and lanthanum hydroxide is added to it. The mixture is reacted at 40°C for 2 hours, and after washing with water, sulfonated lanolin cerium / lanthanum salt is obtained.

4. The water-based sealing coating for passenger vehicles with anti-flash rust function according to claim 3, characterized in that, The preparation method of potassium lanolinate is as follows: pharmaceutical grade lanolin with a water content of ≤0.5% is heated to 105℃, and negative pressure is turned on for 1 hour to evaporate free small molecule acids and alcohols. After cooling to 80-90℃, 10% potassium hydroxide aqueous solution is added dropwise. After stirring slowly for 6 hours, pure water is added and stirred for 1 hour. After standing for 6 hours, the potassium lanolinate suspension is released from the bottom and the pH is adjusted to about 6-8 with hydrochloric acid to obtain potassium lanolinate.

5. A water-based sealing coating for passenger vehicles with anti-flash rust function according to claim 1, characterized in that, The preparation process of the phenanthrene acid dimethyl ethanolamine salt is as follows: phenanthrene acid is dissolved in n-butanol, heated to 40°C, excess dimethyl ethanolamine is added dropwise and reacted for 1 hour, and n-butanol and dimethyl ethanolamine are distilled off under vacuum to obtain phenanthrene acid dimethyl ethanolamine salt.

6. The water-based sealing coating for passenger vehicles with anti-flash rust function according to claim 1, characterized in that, The preparation process of the ethyl acetoacetate methacrylate-modified isomeric tridecyl alcohol polyoxyethylene ether TO-8 is as follows: the TO-8 emulsifier is dehydrated under vacuum, the dehydrated TO-8 is cooled, hydroquinone monomethyl ether and ethyl acetoacetate methacrylate are added sequentially, stirred, tetrabutyl titanate is added, stirred, heated to 105°C, vacuum negative pressure is turned on, and the reaction is maintained at temperature and pressure for 4 hours. After that, the temperature is cooled to 75-80°C, a small amount of pure water is added, stirred, and then the mixture is dehydrated, removed monomers, and filtered to obtain the ethyl acetoacetate methacrylate-modified isomeric tridecyl alcohol polyoxyethylene ether TO-8.

7. A water-based sealing coating for passenger vehicles with anti-flash rust function according to claim 1, characterized in that, The trade name of the Fischer-Tropsch wax is SASOLWAX C80.

8. A method for preparing a water-based sealing coating for passenger vehicles with anti-flash rust function as described in claim 1 or 2, characterized in that, The method is as follows: water is heated to 60°C, terephthalic acid dihydrazide is added and completely dissolved, and dimethyl ethanolamine salt of phenanthrenecarboxylic acid is added to obtain an aqueous phase solution; Fischer-Tropsch wax and sulfonated lanolin cerium / lanthanum salt are mixed, heated to 80°C and stirred evenly, and then isomeric tridecyl alcohol polyoxyethylene ether TO-8 modified with ethyl acetoacetate methacrylate is added to obtain an oil phase mixture. The molten oil phase mixture is slowly poured into the aqueous phase solution and stirred continuously. After 20 minutes, the mixture is cooled to obtain the target product.

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