Weather-resistant anticorrosive multifunctional modified water-based paint and preparation method thereof

Abstract

The invention discloses a weather-resistant anticorrosive multifunctional modified water-based paint and a preparation method thereof, the water-based paint takes a water-based acrylic emulsion as a film-forming resin matrix, propyl gallate, N-(2-aminoethyl)-3-aminopropyltriethoxysilane and cerous nitrate are introduced in situ on a molecular chain or a crosslinking node of the water-based acrylic emulsion, and the weather-resistant anticorrosive multifunctional modified water-based paint is prepared. A water-based film-forming resin matrix is synergistically modified, and functional small organic molecule allantoin is introduced, so that a stable synergistic effect system is constructed. The water-based paint is prepared from a synergistic modified water-based film-forming resin matrix, functional small organic molecules, an anti-rust pigment and filler and a plurality of auxiliaries step by step. While the low-VOC environment-friendly characteristic of a water-based system is maintained, the weather resistance, the corrosion resistance, the adhesive force and the water-resistant stability of a coating film are remarkably improved, and the water-based paint is suitable for long-term protective coating of a metal base material.

Description

Technical Field

[0001] This invention belongs to the technical field of water-based coatings and functional protective materials, specifically relating to a weather-resistant and corrosion-resistant multifunctional modified water-based paint and its preparation method. Background Technology

[0002] With increasingly stringent environmental regulations, water-based paints have gained widespread attention in the field of metal corrosion protection and coating due to their advantages such as low volatile organic compound (VOC) emissions and high application safety. However, existing water-based paints still generally suffer from insufficient weather resistance, limited anti-corrosion life, and difficulty in achieving a balance of overall coating performance in practical applications. Especially under complex service environments such as ultraviolet radiation, damp heat cycling, and salt spray, the coating film is prone to aging, loss of adhesion, and degradation of protective performance, making it difficult to meet long-term protection requirements.

[0003] Currently, common techniques for improving the corrosion resistance and weather resistance of water-based paints include introducing rust-inhibiting pigments and fillers, adding corrosion inhibitors, or performing single chemical modifications on the film-forming resin. However, these techniques largely rely on physical dispersion or single-point chemical action, resulting in limited structural stability. Functional components are prone to migration or failure during service, making it difficult to form a long-term stable protective structure within the coating film. Furthermore, most functional additives in existing technologies originate from the coatings industry, with relatively simple mechanisms of action, limiting their synergistic effect on improving the weather resistance and corrosion resistance of the coating film.

[0004] Therefore, there is an urgent need to develop a new waterborne paint technology solution that involves creatively and synergistically modifying the waterborne film-forming resin matrix and introducing functional organic small molecules from non-coating fields that can function stably in the coating system. This would allow for the simultaneous improvement of weather resistance, corrosion resistance, and coating structure stability while maintaining the environmentally friendly characteristics of the waterborne system. Summary of the Invention

[0005] To overcome the problems of insufficient weather resistance, rapid degradation of anti-corrosion performance, and unstable synergistic effects of functional components in water-based paints mentioned above, the present invention aims to provide a weather-resistant and anti-corrosion multifunctional modified water-based paint and its preparation method. This is achieved by in-situ dynamic synergistic modification of the water-based film-forming resin matrix and the introduction of functional organic small molecules from non-coating fields to construct a stable multi-synergistic system. The present invention employs synergistic modification of a water-based acrylic film-forming resin by introducing propyl gallate, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, and cerium nitrate, combined with a composite formulation of functional organic small molecules (allantoin) and various additives, to prepare a weather-resistant and anti-corrosion multifunctional modified water-based paint. The beneficial effects of the present invention are: while maintaining the low VOC environmental characteristics of water-based paints, it significantly improves the weather resistance, anti-corrosion properties, and long-term structural stability of the coating film.

[0006] The objective of this invention can be achieved through the following technical solutions: A weather-resistant and corrosion-resistant multifunctional modified water-based paint, comprising the following raw materials in parts by weight: 55-80 parts of a synergistic modified water-based film-forming resin matrix; 0.3-5.0 parts of a functional organic small molecule; 5-25 parts of anti-rust pigments and fillers; 0.2-1.5 parts of a dispersant; 0.1-0.8 parts of a defoamer; 1-6 parts of a film-forming aid; 0.1-1.0 parts of a leveling agent; and 15-35 parts of deionized water. The synergistic modified water-based film-forming resin matrix is ​​an in-situ dynamic synergistic modified resin matrix formed by introducing propyl gallate, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, and cerium nitrate into its molecular chain or cross-linking nodes, under aqueous conditions, through reversible coordination of polyphenol-cerium ions, organosilicon condensation grafting, and synergistic hydrogen bonding. The functional organic small molecule is allantoin.

[0007] Optionally, the synergistically modified aqueous film-forming resin matrix comprises the following raw materials in parts by weight: 80-92 parts of aqueous acrylic emulsion; 0.5-3.0 parts of propyl gallate; 0.5-3.0 parts of N-(2-aminoethyl)-3-aminopropyltriethoxysilane; and 0.05-1.0 parts of cerium nitrate.

[0008] Optionally, the method for preparing the synergistically modified aqueous film-forming resin matrix includes the following steps: (1) Weigh out the aqueous acrylic emulsion, propyl gallate, N-(2-aminoethyl)-3-aminopropyltriethoxysilane and cerium nitrate, add propyl gallate to the aqueous acrylic emulsion and disperse and mix under stirring conditions; (2) Add N-(2-aminoethyl)-3-aminopropyltriethoxysilane to the dispersion system and continue stirring to allow it to condense under aqueous conditions and form a grafted modified system with the acrylic emulsion; (3) Add cerium nitrate to the grafting modification system and react under stirring conditions to allow propyl gallate to coordinate with cerium ions to obtain a synergistically modified aqueous film-forming resin matrix.

[0009] Optionally, the reaction conditions in step (1) are stirring and dispersing at 20–40°C for 10–60 min.

[0010] Optionally, the reaction conditions in step (2) are to stir the reaction at 25–60°C for 30–120 min.

[0011] Optionally, the reaction conditions in step (3) are to continue stirring the reaction at 20–50°C for 20–90 min.

[0012] Optionally, the anti-rust pigment and filler is a mixture of zinc phosphate and mica iron oxide in a mass ratio of (1-4):(1-3); the dispersant is a mixture of sodium polycarboxylate and fatty alcohol polyoxyethylene ether in a mass ratio of (1-3):(1-5); the defoamer is a mixture of polydimethylsiloxane and hydrophobic silica in a mass ratio of (5-15):(1-4); the film-forming aid is a mixture of dipropylene glycol butyl ether and ethylene glycol butyl ether in a mass ratio of (1-4):(1-4); and the leveling agent is a mixture of modified polysiloxane and acrylate leveling agent in a mass ratio of (1-3):(1-5).

[0013] Optionally, a method for preparing a weather-resistant and corrosion-resistant multifunctional modified water-based paint includes the following steps: S1, weigh out aqueous acrylic emulsion, propyl gallate, N-(2-aminoethyl)-3-aminopropyltriethoxysilane and cerium nitrate. First, add propyl gallate to the aqueous acrylic emulsion and disperse and mix it under stirring. Then, add N-(2-aminoethyl)-3-aminopropyltriethoxysilane to allow it to condense under aqueous conditions and form a grafted modified system with the acrylic emulsion. Finally, add cerium nitrate to react and obtain a synergistically modified aqueous film-forming resin matrix. S2, add allantoin to deionized water and dissolve or disperse it under stirring to obtain a functional organic small molecule dispersion system, and add the functional organic small molecule dispersion system to the synergistic modified aqueous film-forming resin matrix and stir to mix evenly. S3, add rust-inhibiting pigments and fillers, dispersants, film-forming aids, defoamers and leveling agents to the mixing system in sequence, and fully disperse and mix under stirring conditions to adjust the viscosity of the system to obtain weather-resistant and corrosion-resistant multifunctional modified water-based paint.

[0014] Optionally, the reaction conditions for step S1 are stirring at 20–50°C for 30–120 min; and the reaction conditions for step S2 are stirring and dispersing at 20–40°C for 10–60 min.

[0015] Optionally, the reaction conditions for step S3 are to continue stirring and mixing at 20–40°C for 20–90 min.

[0016] The beneficial effects of this invention are: This invention synergistically modifies waterborne acrylic film-forming resin by in-situ introducing propyl gallate, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, and cerium nitrate into the molecular chain or cross-linking nodes of the resin. During film formation, a dynamic synergistic modification structure combining polyphenol-metal coordination and organosilicon grafting is constructed, transforming the waterborne film-forming resin matrix from a traditional physical film-forming system into a functionalized film-forming system with an endogenous synergistic network. This significantly improves the structural stability and weather resistance of the coating under UV irradiation, humid heat cycling, and corrosive environments. Simultaneously, this invention is the first to introduce allantoin, derived from the pharmaceutical and cosmetic fields, into a waterborne anti-corrosion paint system. Through the amide and hydroxyl groups in the molecule, allantoin forms a multi-site stabilizing effect with the synergistically modified resin network, effectively inhibiting the migration and loss of functional components and forming a durable and stable protective state on the metal substrate surface. Thus, while maintaining the low VOC environmental characteristics of the waterborne system, it achieves a synergistic improvement in weather resistance, corrosion resistance, and long-term service reliability of the coating, demonstrating significant inventiveness and practical value. Attached Figure Description

[0017] The invention will now be further described with reference to the accompanying drawings.

[0018] Figure 1 The infrared spectra of the aqueous film-forming resin matrix and the synergistically modified aqueous film-forming resin matrix are compared. Figure 2 This is a comparison chart of the neutral salt spray test time results for samples with different ratios. Detailed Implementation

[0019] The present invention will be further described below with reference to specific embodiments. However, the present invention is not limited to the following embodiments. Equivalent adjustments made without departing from the spirit and essence of the present invention should also be considered to fall within the protection scope of the present invention.

[0020] Example 1: This example aims to verify the feasibility and system stability of the weather-resistant and anti-corrosion multifunctional modified water-based paint of the present invention under conditions of high degree of modification and high content of functional components by using synergistic modification components and upper limits of reaction conditions.

[0021] Preparation method S1, Preparation of synergistically modified aqueous film-forming resin matrix Weigh 92 parts of aqueous acrylic emulsion, add 3.0 parts of propyl gallate under stirring, and disperse at 40°C for 60 min. Then add 3.0 parts of N-(2-aminoethyl)-3-aminopropyltriethoxysilane and stir at 60°C for 120 min to allow it to condense and form a grafted modified system with the acrylic emulsion under aqueous conditions. Finally, add 1.0 part of cerium nitrate and continue stirring at 50°C for 90 min to obtain a synergistically modified aqueous film-forming resin matrix. S2, the introduction of functional organic small molecules 5.0 parts of allantoin were added to 35 parts of deionized water and stirred and dispersed at 40°C for 60 min to obtain a functional organic small molecule dispersion system. This system was then added to the above-mentioned synergistically modified aqueous film-forming resin matrix and stirred until homogeneous. Preparation of S3, a multi-functional modified water-based paint with weather resistance and corrosion resistance. Add 25 parts of rust-inhibiting pigments and fillers, 1.5 parts of dispersant, 6 parts of film-forming aid, 0.8 parts of defoamer, and 1.0 part of leveling agent to the obtained mixture in sequence. Continue stirring and mixing at 40℃ for 90 minutes, and adjust the viscosity of the system to obtain a weather-resistant and corrosion-resistant multifunctional modified water-based paint.

[0022] Example 2: This example aims to verify the overall balance between performance and system stability of the technical solution of the present invention by using the intermediate values ​​of each component and reaction conditions.

[0023] Preparation method S1, Preparation of synergistically modified aqueous film-forming resin matrix Weigh 86 parts of aqueous acrylic emulsion, add 1.75 parts of propyl gallate, stir and disperse at 30°C for 30 min, then add 1.75 parts of N-(2-aminoethyl)-3-aminopropyltriethoxysilane, stir and react at 40°C for 60 min, then add 0.5 parts of cerium nitrate, and continue stirring and reacting at 35°C for 45 min to obtain a synergistically modified aqueous film-forming resin matrix; Figure 1 The infrared spectrum of the unmodified aqueous acrylic emulsion mainly showed a strong absorption peak of the ester group C=O near 1730 cm⁻¹ and an alkyl C–H stretching vibration peak in the range of 2950–2850 cm⁻¹. The overall spectrum was dominated by the characteristics of acrylic resin, with a weak –OH absorption band, indicating that the system was mainly composed of physical film-forming structures. After synergistic modification, the broad –OH peak in the range of 3400–3500 cm⁻¹ was significantly enhanced and broadened, and a new aromatic ring vibration peak appeared in the region of 1600–1500 cm⁻¹, indicating that propyl gallate was successfully introduced and participated in the modification. Hydrogen bonding and coordination interactions; obvious Si–O–Si / Si–O–C characteristic absorption peaks appear in the 1100–1030 cm⁻¹ region, and organosilicon-related vibrational peaks appear in the 900–800 cm⁻¹ region, proving that organosilicon undergoes condensation grafting in the resin; the newly added metal–oxygen-related absorption in the low wavenumber region further corroborates the formation of polyphenol–cerium ion coordination structure; in summary, the infrared results show that the modified system is not a simple physical mixture, but rather a stable dynamic synergistic modified structure formed in the resin matrix through the synergistic effect of polyphenols, organosilicon and cerium ions. S2, the introduction of functional organic small molecules Add 2.5 parts allantoin to 25 parts deionized water, stir and disperse at 30°C for 30 min, and then add to the synergistically modified aqueous film-forming resin matrix and stir to mix evenly. Preparation of S3, a multi-functional modified water-based paint with weather resistance and corrosion resistance. Add 15 parts of rust-inhibiting pigments and fillers, 0.8 parts of dispersant, 3.5 parts of film-forming aid, 0.4 parts of defoamer, and 0.5 parts of leveling agent to the mixture in sequence, and continue stirring and mixing at 30°C for 45 minutes to obtain a weather-resistant and corrosion-resistant multifunctional modified water-based paint.

[0024] Example 3: This example aims to verify the basic feasibility of the technical solution of the present invention under low addition amount and mild reaction conditions by using the lower limit values ​​of synergistic modification components and reaction conditions.

[0025] Preparation method S1, Preparation of synergistically modified aqueous film-forming resin matrix Weigh 80 parts of aqueous acrylic emulsion, add 0.5 parts of propyl gallate, stir and disperse at 20°C for 10 min, then add 0.5 parts of N-(2-aminoethyl)-3-aminopropyltriethoxysilane, stir and react at 25°C for 30 min, then add 0.05 parts of cerium nitrate, and continue stirring and reacting at 20°C for 20 min to obtain a synergistically modified aqueous film-forming resin matrix; S2, the introduction of functional organic small molecules Add 0.3 parts allantoin to 15 parts deionized water, stir and disperse at 20°C for 10 min, and then add to the synergistically modified aqueous film-forming resin matrix and stir to mix evenly. Preparation of S3, a multi-functional modified water-based paint with weather resistance and corrosion resistance. Add 5 parts of rust-inhibiting pigments and fillers, 0.2 parts of dispersant, 1.0 part of film-forming aid, 0.1 part of defoamer and 0.1 part of leveling agent to the mixing system in sequence, and continue to stir and mix for 20 minutes at 20℃ to obtain weather-resistant and corrosion-resistant multifunctional modified water-based paint.

[0026] Comparative Example 1: This comparative example aims to compare and verify the inventive contribution of "polyphenol-organosilicon-cerium ion synergistic modification" by modifying only the aqueous film-forming resin matrix while keeping the other components and reaction conditions of Example 2 unchanged.

[0027] Preparation method S1, Preparation of aqueous film-forming resin matrix Weigh 86 parts of aqueous acrylic emulsion, add 1.75 parts of propyl gallate, and stir and disperse at 30°C for 30 min; then continue stirring at 40°C for 60 min; and then continue stirring at 35°C for 45 min to obtain a single modified aqueous film-forming resin matrix. S2, the introduction of functional organic small molecules Add 2.5 parts allantoin to 25 parts deionized water, stir and disperse at 30°C for 30 min, and then add to the single modified aqueous film-forming resin matrix and stir to mix evenly. Preparation of S3, a multi-functional modified water-based paint with weather resistance and corrosion resistance. Add 15 parts of rust-inhibiting pigments and fillers, 0.8 parts of dispersant, 3.5 parts of film-forming aid, 0.4 parts of defoamer, and 0.5 parts of leveling agent to the mixing system in sequence, and continue stirring and mixing at 30°C for 45 minutes to obtain water-based paint.

[0028] Comparative Example 2: This comparative example aims to compare and verify the contribution of the "multi-site synergistic modification network" to the stability and protective performance of the system by performing single organosilicon graft modification on the aqueous film-forming resin matrix while keeping the other components and reaction conditions of Example 2 unchanged.

[0029] Preparation method S1, Preparation of aqueous film-forming resin matrix Weigh 86 parts of aqueous acrylic emulsion, add 1.75 parts of N-(2-aminoethyl)-3-aminopropyltriethoxysilane under stirring, and stir and react at 40°C for 60 min; then stir and disperse at 30°C for 30 min; and then continue stirring at 35°C for 45 min to obtain a single modified aqueous film-forming resin matrix. S2, the introduction of functional organic small molecules Add 2.5 parts allantoin to 25 parts deionized water, stir and disperse at 30°C for 30 min, and then add to the single modified aqueous film-forming resin matrix and stir to mix evenly. Preparation of S3, a multi-functional modified water-based paint with weather resistance and corrosion resistance. Add 15 parts of rust-inhibiting pigments and fillers, 0.8 parts of dispersant, 3.5 parts of film-forming aid, 0.4 parts of defoamer, and 0.5 parts of leveling agent to the mixing system in sequence, and continue stirring and mixing at 30°C for 45 minutes to obtain water-based paint.

[0030] Comparative Example 3: This comparative example aims to compare and verify the creative role of "cross-domain functional organic small molecules" in synergistic improvement of weather resistance and corrosion protection by removing only the functional organic small molecule allantoin while keeping the synergistic modification of the aqueous film-forming resin matrix and its reaction conditions unchanged in Example 2.

[0031] Preparation method S1, Preparation of synergistically modified aqueous film-forming resin matrix Weigh 86 parts of aqueous acrylic emulsion, add 1.75 parts of propyl gallate, stir and disperse at 30°C for 30 min, then add 1.75 parts of N-(2-aminoethyl)-3-aminopropyltriethoxysilane, stir and react at 40°C for 60 min, then add 0.5 parts of cerium nitrate, and continue stirring and reacting at 35°C for 45 min to obtain a synergistically modified aqueous film-forming resin matrix; S2, the introduction of functional organic small molecules 25 parts of deionized water were stirred and dispersed at 30°C for 30 minutes, and then added to the synergistically modified aqueous film-forming resin matrix and stirred until homogeneous. Preparation of S3, a multi-functional modified water-based paint with weather resistance and corrosion resistance. Add 15 parts of rust-inhibiting pigments and fillers, 0.8 parts of dispersant, 3.5 parts of film-forming aid, 0.4 parts of defoamer, and 0.5 parts of leveling agent to the mixing system in sequence, and continue stirring and mixing at 30°C for 45 minutes to obtain water-based paint.

[0032] Performance testing: 1. Salt spray corrosion resistance test method: The water-based paints prepared in the examples and comparative examples were coated onto the surface of standard carbon steel test plates that had been degreased, derusted, and polished. The dry film thickness was controlled to be 60–80 μm. After curing at room temperature for 7 days, the test was conducted according to the neutral salt spray test method. The test plates were placed in a salt spray test chamber and continuously sprayed at 35°C. The spray medium was a 5% sodium chloride aqueous solution. The blistering, rusting, and coating failure on the test plate surface were observed periodically to evaluate the anti-corrosion durability of the coatings of different systems.

[0033] 2. Weathering resistance test method: The coating samples obtained in the examples and comparative examples were placed in an accelerated UV aging test chamber and subjected to weathering aging tests using an alternating cycle of UV irradiation and condensation. The temperature was controlled at 60°C during the UV irradiation stage and at 50°C during the condensation stage. The test was conducted according to a set cycle, and the coating surface was periodically observed for chalking, cracking, discoloration, or loss of gloss during the aging process to evaluate the influence of the synergistic modified resin matrix and functional organic small molecules on the weathering stability of the coating.

[0034] 3. Coating adhesion test method: The water-based paints prepared in the examples and comparative examples were coated on the surface of standard metal substrates and fully cured. The adhesion of the coating was tested by the cross-cut test. A grid of specified size was drawn on the surface of the coating and peeled off with standard tape. The peeling off of the coating in the grid area was observed to evaluate the effect of different modification methods on the interfacial bonding performance between the water-based film-forming resin matrix and the metal substrate.

[0035] 4. Test methods for coating water resistance and structural stability: The coated test plates obtained in the examples and comparative examples were completely immersed in deionized water and continuously soaked for a set time at room temperature. After removal, the coatings were observed to see if blistering, whitening, peeling, or a decrease in mechanical properties occurred. The stability of functional organic small molecules in the synergistically modified aqueous film-forming resin matrix and their impact on the long-term structural integrity of the coating were evaluated in combination with the changes in the appearance of the coating.

[0036] Table 1 Comparison of Performance Test Results

[0037] As shown in Table 1, the different embodiments and comparative examples exhibit significant differences in salt spray corrosion resistance, weather aging resistance, coating adhesion, water resistance, and structural stability. Overall, Examples 1-3 are significantly superior to the comparative examples in all performance indicators, with Example 2 showing the most outstanding performance in several key indicators, demonstrating the advantages of the synergistic modification system in terms of comprehensive performance.

[0038] In terms of salt spray corrosion resistance, Figure 2 In Example 2, the duration of no significant rust under neutral salt spray conditions reached 960 hours, significantly higher than the 720 hours of Example 1 and the 600 hours of Example 3, and also significantly better than the 360 ​​hours of Comparative Example 1, the 420 hours of Comparative Example 2, and the 480 hours of Comparative Example 3. These results indicate that, compared to systems with single modified or non-functional small organic molecules, the synergistic modification of the aqueous film-forming resin matrix combined with allantoin can effectively delay the erosion of metal substrates by corrosive media.

[0039] Regarding weather resistance and aging performance, Example 2 showed a gloss loss rate of only 10% after QUV aging testing, significantly lower than the 18% of Example 1 and 22% of Example 3, while the gloss loss rates of Comparative Examples 1, 2, and 3 reached 35%, 32%, and 28%, respectively. This result indicates that the synergistic modified structure exhibits higher stability under UV irradiation and thermal cycling conditions, and can significantly slow down the coating aging process.

[0040] Regarding coating adhesion, Example 2 achieved a grade 0 adhesion, Example 1 achieved a grade 1, and Example 3 achieved grades 1-2, all significantly better than the grades 3 of Comparative Examples 1 and 2, and grades 2-3 of Comparative Example 3. This result indicates that synergistic modification of the aqueous film-forming resin matrix is ​​beneficial for enhancing the interfacial bonding strength between the coating and the metal substrate, thereby improving the long-term service reliability of the coating.

[0041] In the water immersion and structural stability tests, Example 2 showed no bubbling after continuous immersion for 240 hours, Examples 1 and 3 remained stable for 168 hours and 120 hours, respectively, while Comparative Examples 1, 2, and 3 only maintained stability for 72 hours, 96 hours, and 96 hours, respectively. This difference further demonstrates that the synergistic modification system can effectively inhibit water penetration and maintain the integrity of the coating structure.

[0042] In summary, based on the specific data in Table 1, it can be seen that the present invention significantly improves multiple performance dimensions such as salt spray resistance, anti-aging, adhesion, and water resistance by multi-component synergistic modification of the aqueous film-forming resin matrix and the introduction of functional organic small molecule allantoin. Among them, Example 2 shows the best comprehensive balance effect in all performance indicators, fully demonstrating the creativity and practical value of the technical solution of the present invention.

Claims

1. A weather-resistant and corrosion-resistant multifunctional modified water-based paint, characterized in that, The weather-resistant and corrosion-resistant multifunctional modified waterborne paint comprises the following raw materials in parts by weight: 55-80 parts of synergistic modified waterborne film-forming resin matrix; 0.3-5.0 parts of functional organic small molecules; 5-25 parts of anti-rust pigments and fillers; 0.2-1.5 parts of dispersant; 0.1-0.8 parts of defoamer; 1-6 parts of film-forming aid; 0.1-1.0 parts of leveling agent; and 15-35 parts of deionized water. The synergistic modified waterborne film-forming resin matrix is ​​an in-situ dynamic synergistic modified resin matrix formed by introducing propyl gallate, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, and cerium nitrate into its molecular chain or cross-linking nodes, under aqueous conditions, through reversible coordination of polyphenol-cerium ions, organosilicon condensation grafting, and hydrogen bonding synergistic effects. The functional organic small molecule is allantoin.

2. The weather-resistant and corrosion-resistant multifunctional modified water-based paint according to claim 1, characterized in that, The synergistically modified aqueous film-forming resin matrix comprises the following raw materials in parts by weight: 80-92 parts of aqueous acrylic emulsion; 0.5-3.0 parts of propyl gallate; 0.5-3.0 parts of N-(2-aminoethyl)-3-aminopropyltriethoxysilane; and 0.05-1.0 parts of cerium nitrate.

3. A weather-resistant and corrosion-resistant multifunctional modified water-based paint according to claim 1 or 2, characterized in that, The method for preparing the synergistically modified aqueous film-forming resin matrix includes the following steps: (1) Weigh out the aqueous acrylic emulsion, propyl gallate, N-(2-aminoethyl)-3-aminopropyltriethoxysilane and cerium nitrate, add propyl gallate to the aqueous acrylic emulsion and disperse and mix under stirring conditions; (2) Add N-(2-aminoethyl)-3-aminopropyltriethoxysilane to the dispersion system and continue stirring to allow it to condense under aqueous conditions and form a grafted modified system with the acrylic emulsion; (3) Add cerium nitrate to the grafting modification system and react under stirring conditions to allow propyl gallate to coordinate with cerium ions to obtain a synergistically modified aqueous film-forming resin matrix.

4. The weather-resistant and corrosion-resistant multifunctional modified water-based paint according to claim 3, characterized in that, The reaction conditions for step (1) are stirring and dispersing at 20-40°C for 10-60 minutes.

5. The weather-resistant and corrosion-resistant multifunctional modified water-based paint according to claim 3, characterized in that, The reaction conditions for step (2) are stirring at 25-60°C for 30-120 minutes.

6. The weather-resistant and corrosion-resistant multifunctional modified water-based paint according to claim 3, characterized in that, The reaction conditions for step (3) are to continue stirring the reaction at 20-50°C for 20-90 minutes.

7. The weather-resistant and corrosion-resistant multifunctional modified water-based paint according to claim 1, characterized in that, The rust-preventive pigment and filler are composed of zinc phosphate and mica iron oxide in a mass ratio of (1-4):(1-3); the dispersant is composed of sodium polycarboxylate and fatty alcohol polyoxyethylene ether in a mass ratio of (1-3):(1-5); the defoamer is composed of polydimethylsiloxane and hydrophobic silica in a mass ratio of (5-15):(1-4); the film-forming aid is composed of dipropylene glycol butyl ether and ethylene glycol butyl ether in a mass ratio of (1-4):(1-4); and the leveling agent is composed of modified polysiloxane and acrylate leveling agent in a mass ratio of (1-3):(1-5).

8. A method for preparing a weather-resistant and corrosion-resistant multifunctional modified water-based paint, characterized in that, The preparation method includes the following steps: S1, weigh out aqueous acrylic emulsion, propyl gallate, N-(2-aminoethyl)-3-aminopropyltriethoxysilane and cerium nitrate. First, add propyl gallate to the aqueous acrylic emulsion and disperse and mix it under stirring. Then, add N-(2-aminoethyl)-3-aminopropyltriethoxysilane to allow it to condense under aqueous conditions and form a grafted modified system with the acrylic emulsion. Finally, add cerium nitrate to react and obtain a synergistically modified aqueous film-forming resin matrix. S2, add allantoin to deionized water and dissolve or disperse it under stirring to obtain a functional organic small molecule dispersion system, and add the functional organic small molecule dispersion system to the synergistic modified aqueous film-forming resin matrix and stir to mix evenly. S3, add rust-inhibiting pigments and fillers, dispersants, film-forming aids, defoamers and leveling agents to the mixing system in sequence, and fully disperse and mix under stirring conditions to adjust the viscosity of the system to obtain weather-resistant and corrosion-resistant multifunctional modified water-based paint.

9. The method for preparing a weather-resistant and corrosion-resistant multifunctional modified water-based paint according to claim 8, characterized in that, The reaction conditions for step S1 are stirring at 20–50°C for 30–120 min; the reaction conditions for step S2 are stirring and dispersing at 20–40°C for 10–60 min.

10. The method for preparing a weather-resistant and corrosion-resistant multifunctional modified water-based paint according to claim 8, characterized in that, The reaction conditions for step S3 are to continue stirring and mixing at 20–40°C for 20–90 minutes.

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