Environment-friendly wear-resistant water-based paint and preparation method thereof

Abstract

The present application relates to the technical field of paint, and particularly relates to an environment-friendly wear-resistant water-based paint and a preparation method thereof.The environment-friendly wear-resistant water-based paint comprises, by weight fraction, modified acrylic emulsion 35-50 parts, functional filler 10-15 parts, curing agent 5-8 parts, dispersing agent 0.2-0.5 parts, defoaming agent 0.1-0.5 parts and leveling agent 0.3-0.5 parts.The modified acrylic emulsion is prepared by an emulsion polymerization method, which can not only improve the corrosion resistance of the paint, but also has good hydrophobicity, ensures that the barrier layer remains intact in a corrosive environment for a long time, and improves the salt mist resistance and acid and alkali corrosion resistance of the paint.The present application introduces organic modified montmorillonite as the functional filler, which improves the dispersibility and compatibility of the montmorillonite in the matrix, improves the wear resistance of the paint, and endows the paint with excellent antibacterial properties.

Description

Technical Field

[0001] This invention relates to the field of coating technology, and in particular to an environmentally friendly, wear-resistant water-based coating and its preparation method. Background Technology

[0002] In response to national environmental protection policies, the packaging coatings industry is accelerating its transformation towards water-based technologies, gradually reducing the use of solvent-based coatings in metal packaging. Water-based coatings, using water as the dispersion medium, offer significant advantages over traditional solvent-based coatings, including lower volatile organic compound (VOC) content, non-toxicity, odorlessness, and superior environmental performance. Against this backdrop, developing environmentally compliant water-based coatings for niche markets such as easy-open lids, food cans, and steel drums is particularly important.

[0003] Most existing water-based coatings use acrylic emulsions as the base, which has advantages such as environmental friendliness, convenient application, and low cost. However, the molecular structure of ordinary acrylic resins is mostly linear, resulting in insufficient anti-corrosion performance, poor salt spray resistance, and inadequate abrasion resistance. In addition, the interfacial bonding strength between water-based coatings and metal substrates is usually weak, making them prone to interfacial failure under external forces or environmental erosion, further shortening the protective life of the coating.

[0004] To improve the overall performance of coatings, existing technologies often involve adding anti-corrosion pigments or modifying resins. However, traditional anti-corrosion pigments can easily lead to a decrease in coating stability and have limited anti-corrosion effects. Resin modification often employs simple copolymerization or doping methods, which makes it difficult to form a strong interfacial bond between the coating and the metal substrate. This makes it impossible to effectively inhibit electrochemical reactions on the metal surface, and salt spray and acid / alkali media can easily penetrate the coating, leading to anti-corrosion failure.

[0005] Meanwhile, metal packaging often faces complex challenges of mechanical friction and microbial contamination during transportation, storage, and use, placing higher demands on the abrasion resistance and antibacterial properties of coatings. Therefore, it is necessary to optimize coating formulations to enhance their abrasion resistance and antibacterial capabilities while ensuring environmental performance, in order to meet the actual needs of different application scenarios. Summary of the Invention

[0006] To overcome the shortcomings of existing technologies, one of the objectives of this invention is to provide an environmentally friendly, wear-resistant waterborne coating. This invention designs a modified acrylic emulsion prepared via emulsion polymerization. This not only enhances the coating's anti-corrosion performance but also provides excellent hydrophobic properties, ensuring the barrier layer remains intact in corrosive environments over a long period, and improving the coating's resistance to salt spray and acid / alkali corrosion. This invention introduces organically modified montmorillonite as a functional filler, improving the dispersion and compatibility of montmorillonite in the matrix, enhancing the coating's wear resistance, and endowing it with excellent antibacterial properties.

[0007] The second objective of this invention is to provide a method for preparing an environmentally friendly, wear-resistant water-based coating. This preparation method is simple and highly operable.

[0008] One of the objectives of this invention is achieved through the following technical solution: An environmentally friendly, wear-resistant water-based coating, comprising, by weight: 35-50 parts modified acrylic emulsion, 10-15 parts functional filler, 5-8 parts curing agent, 0.2-0.5 parts dispersant, 0.1-0.5 parts defoamer, and 0.3-0.5 parts leveling agent; The preparation process of the modified acrylic emulsion is as follows: (1) Dissolve N,N,N',N'-tetramethyldiamine and 1,2-ethanedithiol in chloroform, add an ethanol solution of allyl thiourea and cesium carbonate, heat to react, filter, concentrate, and purify to obtain intermediate 1; (2) Dissolve intermediate 1 in 1,4-dioxane, heat to 70-80℃ under nitrogen protection, add catalyst and bistrimethylsiloxymethylsilane, heat to react and obtain active monomer; (3) Add hydroxyethyl methacrylate, methyl methacrylate, butyl acrylate, active monomer, initiator and emulsifier to water and heat to react to obtain modified acrylic emulsion.

[0009] Further, in step (1), the ratio of N,N,N',N'-tetramethyldiamine, 1,2-ethylenedithiol, allylthiourea, cesium carbonate, and chloroform is 10 mmol: 10-12 mmol: 20-22 mmol: 1-1.2 mmol: 5-10 mL; the concentration of the allylthiourea ethanol solution is 2 mol / L; and the heating reaction temperature is 55-60 °C for 6-8 h.

[0010] Further, in step (2), the ratio of intermediate 1, bistrimethylsiloxymethylsilane, and 1,4-dioxane is 10 mmol: 10-12 mmol: 30 mL; the mass of the catalyst is 20-30 ppm of the total mass of intermediate 1, bistrimethylsiloxymethylsilane, and 1,4-dioxane, and the catalyst is chloroplatinic acid; the heating reaction temperature is 70-80 °C, and the time is 7-9 h.

[0011] Further, in step (3), the mass ratio of methyl methacrylate, butyl acrylate, hydroxyethyl methacrylate, active monomer, initiator, emulsifier and water is (25-35):(10-15):(6-10):(3-5):(0.05-0.2):(2-5):100; the initiator is benzoyl peroxide; the emulsifier is composed of sodium dodecyl sulfate and alkylphenol polyoxyethylene ether in a mass ratio of (1-1.5):1; the heating reaction temperature is 70-75℃ and the time is 3-6h.

[0012] Furthermore, the preparation method of the functional filler is as follows: A. 3-Trimethoxysilane-2-bromo-2-methylpropionate was added to an aqueous ethanol solution and stirred to hydrolyze. Montmorillonite was added and the mixture was heated to react, yielding intermediate 2. B. Disperse intermediate 2 in tetrahydrofuran, add diethyl p-[2-(diethylamino)-2-oxoethyl]phosphonate, and heat the reaction under nitrogen protection to obtain intermediate 3; C. Disperse intermediate 3 in dichloromethane, add trimethylbromosilane, and stir the reaction at room temperature to obtain the functional filler.

[0013] Further, in step A, the ratio of methyl 3-trimethoxysilane-2-bromo-2-methylpropionate to the aqueous ethanol solution is 4.8-5.6 g: 100 mL; the mass ratio of methyl 3-trimethoxysilane-2-bromo-2-methylpropionate to montmorillonite is 1: (1.2-1.6); the pH of the aqueous ethanol solution is 4-5, and the concentration is 90 wt%; the hydrolysis time is 4-5 h; and the heating reaction temperature is 70-75 °C, and the time is 20-24 h.

[0014] Further, in step B, the ratio of intermediate 2, diethyl p-[2-(diethylamino)-2-oxoethyl]phosphonate and tetrahydrofuran is 1 g: 1.2-1.8 g: 10-20 mL; the heating reaction is carried out at a temperature of 50-55 °C for 36-42 h.

[0015] Further, in step C, the ratio of intermediate 3, trimethylbromosilane, and dichloromethane is 1g:6-9g:20-30mL; and the stirring reaction time is 12-14h.

[0016] Furthermore, the curing agent is a hydrophilic aliphatic polyisocyanate; the defoamer is an organosilicon defoamer BYK-024; the leveling agent is BYK-410; and the dispersant is BYK-190.

[0017] The second objective of this invention is achieved by the following technical solution: A method for preparing an environmentally friendly, wear-resistant water-based coating includes the following steps: The modified acrylic emulsion and curing agent are mixed and stirred for 15-25 minutes. Then, functional fillers, dispersants, defoamers and leveling agents are added and stirred for 30-45 minutes to obtain the environmentally friendly wear-resistant water-based coating.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention uses N,N,N',N'-tetramethylmethyldiamine, 1,2-ethylenedithiol, and allyl thiourea as raw materials to synthesize an intermediate 1 containing double bonds at both ends. Further, utilizing the single-ended double bonds of intermediate 1, it reacts with bis(trimethylsiloxymethylsilane) to prepare an active monomer. Finally, using hydroxyethyl methacrylate, methyl methacrylate, and butyl acrylate as polymerization monomers, this active monomer is introduced, and a modified acrylic emulsion is prepared via emulsion polymerization. The NH-C=S-NH thiourea group in the active monomer structure can achieve strong interfacial adsorption by forming coordination and complexation bonds with the metal substrate, while effectively inhibiting electrochemical reactions on the metal surface, significantly improving the anti-corrosion performance of the coating. The siloxane segments introduced by bis(trimethylsiloxymethylsilane) have hydrophobicity and low surface energy, forming low-surface-energy hydrophobic regions within the coating, significantly reducing the penetration and diffusion of salt spray and acid / alkali media in the coating. Simultaneously, its chemical stability ensures the barrier layer remains intact in corrosive environments for a long time, thereby effectively improving the salt spray resistance of the coating.

[0019] 2. This invention also incorporates organically modified montmorillonite as a functional filler. Montmorillonite is modified with methyl 3-trimethoxysilane-2-bromo-2-methylpropionate to obtain silane-modified montmorillonite. The bromoalkyl groups on its surface further undergo a quaternization reaction with diethyl p-[2-(diethylamino)-2-oxoethyl]phosphonate. Finally, the phosphate protecting groups are removed with trimethylbromosilane to obtain organically modified montmorillonite. After organic modification, the surface of montmorillonite contains phosphate groups, which can chelate with the metal substrate surface, significantly improving the interfacial bonding strength between the coating and the metal substrate. Simultaneously, the carboxylic acid ester groups on its surface effectively improve the compatibility between the filler and the acrylic resin matrix, facilitating the uniform dispersion of the montmorillonite nanosheets. The synergistic effect of improved interfacial strength, the nano-reinforcing effect of montmorillonite, and the improved filler dispersion enhances the wear resistance of the coating. Furthermore, the quaternary ammonium groups on the surface of montmorillonite impart excellent antibacterial properties to the coating. Attached Figure Description

[0020] Figure 1 This is an electron microscope image of the functional filler obtained in Example 1 of the present invention. Detailed Implementation

[0021] The present invention will now be further described with reference to the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments. Specific conditions not specified in the embodiments are performed according to conventional conditions or conditions recommended by the manufacturer. Unless otherwise specified, all reagents or instruments used are conventional products obtained through commercial channels.

[0022] The curing agent of this invention is hydrophilic aliphatic polyisocyanate (Covestro XP2655); the defoamer is silicone defoamer BYK-024; the leveling agent is BYK-410; and the dispersant is BYK-190. Example

[0023] This embodiment provides an environmentally friendly, wear-resistant water-based coating, which comprises, by weight, 45 parts of modified acrylic emulsion, 12 parts of functional filler, 7 parts of curing agent, 0.4 parts of dispersant, 0.3 parts of defoamer, and 0.4 parts of leveling agent.

[0024] The preparation process of the modified acrylic emulsion is as follows: (1) N,N,N',N'-tetramethylmethylenediamine and 1,2-ethanedithiol were dissolved in chloroform to obtain a mixed solution; cesium carbonate was dissolved in an ethanol solution of allyl thiourea (concentration of 2 mol / L) and then added to the mixed solution; the ratio of N,N,N',N'-tetramethylmethylenediamine, 1,2-ethanedithiol, allyl thiourea, cesium carbonate and chloroform was 10 mmol: 11 mmol: 21 mmol: 1.1 mmol: 8 mL; after reacting at 58 °C for 7 h, the mixture was filtered, the filtrate was concentrated under reduced pressure, the crude product was redissolved in dichloromethane, washed with 1 M dilute hydrochloric acid and saturated sodium chloride, dried over anhydrous sodium sulfate, and purified by column chromatography (elution: petroleum ether / ethyl acetate volume ratio 10:1→5:1→2:1→1:1 gradient elution) to obtain intermediate 1; Intermediate 1 1 HNMR: (400MHz, DMSO-) d6 ) δ: 2.81 (s, 4H), 4.60 (s, 4H), 4.90-4.94 (dd, 4H), 5.04-5.08 (m, 2H), 5.17-5.21 (m, 2H), 5.83-5.87 (m, 2H), 7.82 (s, 2H), 9.01 (s, 2H). MS(ESI) m / z=350.07 [M].

[0025] (2) Dissolve intermediate 1 in 1,4-dioxane, heat to 75°C under nitrogen protection, add chloroplatinic acid (catalyst), and then slowly add bis(trimethylsiloxymethylsilane) at a rate of 1 drop / 2 seconds. The ratio of intermediate 1, bis(trimethylsiloxymethylsilane) and 1,4-dioxane is 10 mmol: 11 mmol: 30 mL. The mass of chloroplatinic acid is 25 ppm of the total mass of intermediate 1, bis(trimethylsiloxymethylsilane) and 1,4-dioxane. After reacting at 75°C for 8 h, the catalyst is adsorbed with activated carbon, and the solvent and unreacted bis(trimethylsiloxymethylsilane) are removed by rotary evaporation to obtain the active monomer. active monomers 1 HNMR: (400MHz, DMSO-) d6 ) δ: 0.14 (s, 3H), 0.21 (s, 18H), 0.59-0.63 (m, 2H), 1.47-1.51 (m, 2H), 2.81 (s, 4H), 3.65-3.69 (m, 2H), 4.60 (s, 4H ), 4.90-4.94 (dd, 2H), 5.04-5.08 (m, H), 5.17-5.21 (m, H), 5.83-5.87 (m, H), 7.31 (s, H), 7.82 (s, H), 9.01 (s, 2H). MS (ESI) m / z=572.17 [M].

[0026] The reactive structural formula of the active monomer is shown below:

[0027] (3) Add hydroxyethyl methacrylate, methyl methacrylate, butyl acrylate, active monomer, initiator (benzoyl peroxide) and emulsifier (sodium dodecyl sulfate and alkylphenol polyoxyethylene ether in a mass ratio of 1-1.5:1) to water and stir until homogeneous. The mass ratio of methyl methacrylate, butyl acrylate, hydroxyethyl methacrylate, active monomer, initiator, emulsifier and water is 30:12:8:4:0.1:4:100. Heat to 72℃ and react for 5 hours to obtain modified acrylic emulsion.

[0028] The preparation method of the functional filler is as follows:

[0029] A. Prepare a 90% (w / w) ethanol aqueous solution, adjust the pH to 4.5 with acetic acid, add methyl 3-trimethoxysilane-2-bromo-2-methylpropionate, wherein the ratio of methyl 3-trimethoxysilane-2-bromo-2-methylpropionate to the ethanol aqueous solution is 5.2 g: 100 mL; stir and hydrolyze for 4.5 h; then add montmorillonite, controlling the mass ratio of methyl 3-trimethoxysilane-2-bromo-2-methylpropionate to montmorillonite to be 1:1.4; react at 72 °C for 22 h, filter, wash with ethanol, and vacuum dry to obtain intermediate 2; B. Intermediate 2 was ultrasonically dispersed in tetrahydrofuran, and diethyl p-[2-(diethylamino)-2-oxoethyl]phosphonate (CAS: 3699-76-1) was added; wherein, the ratio of intermediate 2, diethyl p-[2-(diethylamino)-2-oxoethyl]phosphonate and tetrahydrofuran was 1 g: 1.6 g: 15 mL; under nitrogen protection, the mixture was heated to 52 °C, stirred for 40 h, filtered, washed with ethanol, and dried under vacuum to obtain intermediate 3; C. Intermediate 3 was ultrasonically dispersed in dichloromethane, and trimethylbromosilane was added, controlling the ratio of intermediate 3, trimethylbromosilane, and dichloromethane to be 1 g: 8 g: 25 mL. After stirring overnight at room temperature, the mixture was filtered, washed with diethyl ether, and vacuum dried to obtain the functional packing material. The electron micrograph of the functional packing material is shown below. Figure 1 As shown.

[0030] This embodiment also provides a method for preparing an environmentally friendly, wear-resistant water-based coating, comprising the following steps: The modified acrylic emulsion and curing agent are mixed and stirred for 20 minutes. Then, functional fillers, dispersants, defoamers and leveling agents are added and stirred for 35 minutes to obtain the environmentally friendly wear-resistant water-based coating. Example

[0031] This embodiment provides an environmentally friendly, wear-resistant water-based coating, which comprises, by weight, 35 parts of modified acrylic emulsion, 10 parts of functional filler, 5 parts of curing agent, 0.2 parts of dispersant, 0.1 parts of defoamer, and 0.3 parts of leveling agent.

[0032] The preparation process of the modified acrylic emulsion is as follows: (1) N,N,N',N'-tetramethylmethylenediamine and 1,2-ethanedithiol were dissolved in chloroform to obtain a mixed solution; cesium carbonate was dissolved in an ethanol solution of allyl thiourea (concentration of 2 mol / L) and then added to the mixed solution; the ratio of N,N,N',N'-tetramethylmethylenediamine, 1,2-ethanedithiol, allyl thiourea, cesium carbonate and chloroform was 10 mmol: 10 mmol: 20 mmol: 1 mmol: 5 mL; after reacting at 55 °C for 8 h, the mixture was filtered, the filtrate was concentrated under reduced pressure, the crude product was redissolved in dichloromethane, washed with 1 M dilute hydrochloric acid and saturated sodium chloride, dried over anhydrous sodium sulfate, and purified by column chromatography (elution: petroleum ether / ethyl acetate volume ratio 10:1→5:1→2:1→1:1 gradient elution) to obtain intermediate 1; Intermediate 1 1 The characterization results of HNMR and MS (ESI) m / z are the same as in Example 1.

[0033] (2) Dissolve intermediate 1 in 1,4-dioxane, heat to 70°C under nitrogen protection, add chloroplatinic acid (catalyst), and then slowly add bis(trimethylsiloxymethylsilane) at a rate of 1 drop / 2 seconds. The ratio of intermediate 1, bis(trimethylsiloxymethylsilane) and 1,4-dioxane is 10 mmol: 10 mmol: 30 mL. The mass of chloroplatinic acid is 20 ppm of the total mass of intermediate 1, bis(trimethylsiloxymethylsilane) and 1,4-dioxane. After reacting at 70°C for 9 h, the catalyst is adsorbed with activated carbon, and the solvent and unreacted bis(trimethylsiloxymethylsilane) are removed by rotary evaporation to obtain the active monomer.

[0034] active monomers 1 The characterization results of HNMR and MS (ESI) are the same as in Example 1.

[0035] (3) Add hydroxyethyl methacrylate, methyl methacrylate, butyl acrylate, active monomer, initiator (benzoyl peroxide) and emulsifier (sodium dodecyl sulfate and alkylphenol polyoxyethylene ether in a mass ratio of 1-1.5:1) to water and stir until homogeneous. The mass ratio of methyl methacrylate, butyl acrylate, hydroxyethyl methacrylate, active monomer, initiator, emulsifier and water is 25:10:6:3:0.05:2:100. Heat to 70℃ and react for 6 hours to obtain modified acrylic emulsion.

[0036] The preparation method of the functional filler is as follows: A. Prepare a 90% (w / w) ethanol aqueous solution, adjust the pH to 4 with acetic acid, add methyl 3-trimethoxysilane-2-bromo-2-methylpropionate, wherein the ratio of methyl 3-trimethoxysilane-2-bromo-2-methylpropionate to the ethanol aqueous solution is 4.8 g: 100 mL; stir and hydrolyze for 4 h; then add montmorillonite, controlling the mass ratio of methyl 3-trimethoxysilane-2-bromo-2-methylpropionate to montmorillonite to be 1:1.2; react at 70 °C for 24 h, filter, wash with ethanol, and vacuum dry to obtain intermediate 2; B. Intermediate 2 was ultrasonically dispersed in tetrahydrofuran, and diethyl p-[2-(diethylamino)-2-oxoethyl]phosphonate was added; wherein the ratio of intermediate 2, diethyl p-[2-(diethylamino)-2-oxoethyl]phosphonate and tetrahydrofuran was 1 g: 1.2 g: 10 mL; under nitrogen protection, the mixture was heated to 50 °C and stirred for 42 h, then filtered, washed with ethanol, and dried under vacuum to obtain intermediate 3; C. Disperse intermediate 3 ultrasonically in dichloromethane, add trimethylbromosilane, and control the ratio of intermediate 3, trimethylbromosilane and dichloromethane to be 1g:6g:20mL; stir overnight at room temperature, filter, wash with ether, and vacuum dry to obtain the functional filler.

[0037] This embodiment also provides a method for preparing an environmentally friendly, wear-resistant water-based coating, comprising the following steps: The modified acrylic emulsion and curing agent are mixed and stirred for 15 minutes. Then, functional fillers, dispersants, defoamers and leveling agents are added and stirred for 30 minutes to obtain the environmentally friendly wear-resistant water-based coating. Example

[0038] This embodiment provides an environmentally friendly, wear-resistant water-based coating, which comprises, by weight, 50 parts of modified acrylic emulsion, 15 parts of functional filler, 8 parts of curing agent, 0.5 parts of dispersant, 0.5 parts of defoamer, and 0.5 parts of leveling agent.

[0039] The preparation process of the modified acrylic emulsion is as follows: (1) N,N,N',N'-tetramethylmethyldiamine and 1,2-ethanedithiol were dissolved in chloroform to obtain a mixed solution; cesium carbonate was dissolved in an ethanol solution of allyl thiourea (concentration of 2 mol / L) and then added to the mixed solution; the ratio of N,N,N',N'-tetramethylmethyldiamine, 1,2-ethanedithiol, allyl thiourea, cesium carbonate and chloroform was 10 mmol: 12 mmol: 22 mmol: 1.2 mmol: 10 mL; after reacting at 60 °C for 6 h, the mixture was filtered, the filtrate was concentrated under reduced pressure, the crude product was redissolved in dichloromethane, washed with 1 M dilute hydrochloric acid and saturated sodium chloride, dried over anhydrous sodium sulfate, and purified by column chromatography (elution: petroleum ether / ethyl acetate volume ratio 10:1→5:1→2:1→1:1 gradient elution) to obtain intermediate 1; Intermediate 1 1 The characterization results of HNMR and MS (ESI) m / z are the same as in Example 1.

[0040] (2) Dissolve intermediate 1 in 1,4-dioxane, heat to 80°C under nitrogen protection, add chloroplatinic acid (catalyst), and then slowly add bis(trimethylsiloxymethylsilane) at a rate of 1 drop / 2 seconds. The ratio of intermediate 1, bis(trimethylsiloxymethylsilane) and 1,4-dioxane is 10 mmol: 12 mmol: 30 mL. The mass of chloroplatinic acid is 30 ppm of the total mass of intermediate 1, bis(trimethylsiloxymethylsilane) and 1,4-dioxane. After reacting at 80°C for 7 h, the catalyst is adsorbed with activated carbon, and the solvent and unreacted bis(trimethylsiloxymethylsilane) are removed by rotary evaporation to obtain the active monomer. active monomers 1 The characterization results of HNMR and MS (ESI) are the same as in Example 1.

[0041] (3) Hydroxyethyl methacrylate, methyl methacrylate, butyl acrylate, active monomer, initiator (benzoyl peroxide) and emulsifier (sodium dodecyl sulfate and alkylphenol polyoxyethylene ether in a mass ratio of 1.5:1) are added to water and stirred evenly. The mass ratio of methyl methacrylate, butyl acrylate, hydroxyethyl methacrylate, active monomer, initiator, emulsifier and water is 35:15:10:5:0.2:5:100. The mixture is heated to 75°C and reacted for 3 hours to obtain the modified acrylic emulsion.

[0042] The preparation method of the functional filler is as follows: A. Prepare a 90% (w / w) aqueous ethanol solution, adjust the pH to 5 with acetic acid, add methyl 3-trimethoxysilane-2-bromo-2-methylpropionate, wherein the ratio of methyl 3-trimethoxysilane-2-bromo-2-methylpropionate to the aqueous ethanol solution is 5.6 g: 100 mL; stir and hydrolyze for 5 h; then add montmorillonite, controlling the mass ratio of methyl 3-trimethoxysilane-2-bromo-2-methylpropionate to montmorillonite to be 1:1.6; react at 75 °C for 20 h, filter, wash with ethanol, and vacuum dry to obtain intermediate 2; B. Intermediate 2 was ultrasonically dispersed in tetrahydrofuran, and diethyl p-[2-(diethylamino)-2-oxoethyl]phosphonate was added; wherein the ratio of intermediate 2, diethyl p-[2-(diethylamino)-2-oxoethyl]phosphonate and tetrahydrofuran was 1 g: 1.8 g: 20 mL; under nitrogen protection, the temperature was raised to 55 °C, and the reaction was stirred for 36 h. After filtration, washing with ethanol, and vacuum drying, intermediate 3 was obtained. C. Disperse intermediate 3 ultrasonically in dichloromethane, add trimethylbromosilane, and control the ratio of intermediate 3, trimethylbromosilane and dichloromethane to be 1g:9g:30mL; stir overnight at room temperature, filter, wash with ether, and vacuum dry to obtain the functional filler.

[0043] This embodiment also provides a method for preparing an environmentally friendly, wear-resistant water-based coating, comprising the following steps: The modified acrylic emulsion and curing agent are mixed and stirred for 25 minutes. Then, functional fillers, dispersants, defoamers and leveling agents are added and stirred for 45 minutes to obtain the environmentally friendly wear-resistant water-based coating.

[0044] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that allyl thiourea is used to replace the active monomer; otherwise, they are the same as in Example 1.

[0045] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that montmorillonite is used instead of modified montmorillonite; otherwise, they are the same as in Example 1.

[0046] Experimental Example 1 The coatings obtained in Examples 1-3 and Comparative Examples 1-2 were applied to tinplate substrates and cured to obtain the coatings. The performance of the coatings was tested using the following method.

[0047] (1) Antibacterial properties: The antibacterial rate of the coatings obtained in Examples 1-3 and Comparative Examples 1-2 against Escherichia coli was tested according to the test standard of GB / T21866-2008.

[0048] (2) Abrasion resistance: The abrasion resistance of the coatings obtained in Examples 1-3 and Comparative Examples 1-2 was tested in accordance with GB / T1768-2006.

[0049] (3) Water contact angle: The surface water contact angle of the coatings obtained in Examples 1-3 and Comparative Examples 1-2 was measured using a contact angle measuring instrument.

[0050] (4) The acid and alkali corrosion resistance of the coatings obtained in Examples 1-3 and Comparative Examples 1-2 were tested according to GB / T9274-1988. Acid resistance: soaked in 5wt% hydrochloric acid for 72h; Alkali resistance: soaked in 5wt% sodium hydroxide for 72h. Observe whether there are blistering, peeling, rust spots or other phenomena on the coating surface.

[0051] (5) Salt spray resistance: The coatings obtained in Examples 1-3 and Comparative Examples 1-2 were tested according to the test standard of GB / T10125-2021. After being exposed to neutral salt spray test conditions for 500 hours, the coatings were observed to see whether blistering, wrinkling, peeling and other phenomena occurred.

[0052] The results are shown in Table 1.

[0053] Table 1 Group / Project Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Antibacterial rate (%) 98.5 97.6 98.1 93.6 83.7 Abrasion resistance (mg) 11.2 12.8 12.4 13.7 16.5 Water contact angle (°) 132 126 130 95 122 Acid and alkali resistance No abnormalities No abnormalities No abnormalities Bubbling, slight peeling, and rust spots. Slight bubbling, no peeling, no rust spots Acid and alkali resistance No abnormalities No abnormalities No abnormalities Bubbling, slight peeling, and rust spots. Slight bubbling, no peeling, no rust spots Salt spray resistance No abnormalities No abnormalities No abnormalities Bubbling, slight peeling, and rust spots. Slight bubbling, no peeling, no rust spots As shown in Table 1, the antibacterial rates of Examples 1-3 were all higher than those of Comparative Examples 1-2. Among them, the antibacterial rate of Comparative Example 2 was significantly lower than that of Example 1, indicating that the organically modified montmorillonite introduced in this invention endows the coating with excellent antibacterial properties, while the unmodified montmorillonite basically lacks efficient antibacterial ability. Although Comparative Example 1 still has some antibacterial effect, its effect is not as good as that of Example 1.

[0054] The water contact angles of Examples 1-3 were all higher than those of Comparative Examples 1-2. Among them, the water contact angle of Comparative Example 1 was significantly lower than that of Example 1, which proves that the siloxane segment in the active monomer is the key to high hydrophobicity and low surface energy, and directly determines the coating's resistance to water penetration.

[0055] The lower the abrasion resistance value, the better the abrasion resistance. The abrasion resistance of Examples 1-3 is higher than that of Comparative Examples 1-2. Comparative Example 2 has the worst abrasion resistance because it uses unmodified montmorillonite, which indicates that unmodified montmorillonite has poor compatibility with resin, uneven dispersion, lacks chelation with metal, and has insufficient interfacial strength.

[0056] Examples 1-3 showed no abnormalities on the coating surface after acid, alkali, and salt spray treatment, indicating that the coating of the present invention has good corrosion resistance, acid and alkali resistance, and salt spray resistance, and the coating has strong integrity and protection. Comparative Example 1, where the active monomer was replaced with allyl thiourea, showed rapid penetration of the corrosive medium, electrochemical corrosion of the metal, surface blistering, slight peeling, and rust spots, exhibiting the worst resistance to the medium. This demonstrates that the active monomer of the present invention is key to improving acid and alkali resistance and salt spray resistance. Comparative Example 2 showed slight blistering, no peeling, and no rust spots, but the effect was not as good as Example 1.

[0057] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. An environmentally friendly, wear-resistant water-based coating, characterized in that, The environmentally friendly wear-resistant water-based coating comprises, by weight, 35-50 parts of modified acrylic emulsion, 10-15 parts of functional filler, 5-8 parts of curing agent, 0.2-0.5 parts of dispersant, 0.1-0.5 parts of defoamer, and 0.3-0.5 parts of leveling agent; The preparation process of the modified acrylic emulsion is as follows: (1) Dissolve N,N,N',N'-tetramethyldiamine and 1,2-ethanedithiol in chloroform, add an ethanol solution of allyl thiourea and cesium carbonate, heat to react, filter, concentrate, and purify to obtain intermediate 1; (2) Dissolve intermediate 1 in 1,4-dioxane, heat to 70-80℃ under nitrogen protection, add catalyst and bistrimethylsiloxymethylsilane, heat to react and obtain active monomer; (3) Add hydroxyethyl methacrylate, methyl methacrylate, butyl acrylate, active monomer, initiator and emulsifier to water and heat to react to obtain modified acrylic emulsion.

2. The environmentally friendly wear-resistant water-based coating according to claim 1, characterized in that, In step (1), the ratio of N,N,N',N'-tetramethyldiamine, 1,2-ethylenedithiol, allyl thiourea, cesium carbonate, and chloroform is 10 mmol: 10-12 mmol: 20-22 mmol: 1-1.2 mmol: 5-10 mL; the concentration of the allyl thiourea ethanol solution is 2 mol / L; and the heating reaction temperature is 55-60℃ for 6-8 h.

3. The environmentally friendly wear-resistant water-based coating according to claim 1, characterized in that, In step (2), the ratio of intermediate 1, bis(trimethylsiloxymethylsilane) and 1,4-dioxane is 10 mmol: 10-12 mmol: 30 mL; the mass of the catalyst is 20-30 ppm of the total mass of intermediate 1, bis(trimethylsiloxymethylsilane) and 1,4-dioxane, and the catalyst is chloroplatinic acid; the heating reaction temperature is 70-80 °C and the time is 7-9 h.

4. The environmentally friendly wear-resistant water-based coating according to claim 1, characterized in that, In step (3), the mass ratio of methyl methacrylate, butyl acrylate, hydroxyethyl methacrylate, active monomer, initiator, emulsifier, and water is (25-35):(10-15):(6-10):(3-5):(0.05-0.2):(2-5):100; the initiator is benzoyl peroxide; the emulsifier is composed of sodium dodecyl sulfate and alkylphenol polyoxyethylene ether in a mass ratio of (1-1.5):1; the heating reaction temperature is 70-75℃ and the time is 3-6h.

5. The environmentally friendly, wear-resistant water-based coating according to claim 1, characterized in that, The preparation method of functional fillers is as follows: A. 3-Trimethoxysilane-2-bromo-2-methylpropionate was added to an aqueous ethanol solution and stirred to hydrolyze. Montmorillonite was added and the mixture was heated to react, yielding intermediate 2. B. Disperse intermediate 2 in tetrahydrofuran, add diethyl p-[2-(diethylamino)-2-oxoethyl]phosphonate, and heat the reaction under nitrogen protection to obtain intermediate 3; C. Disperse intermediate 3 in dichloromethane, add trimethylbromosilane, and stir the reaction at room temperature to obtain the functional filler.

6. The environmentally friendly wear-resistant water-based coating according to claim 5, characterized in that, In step A, the ratio of methyl 3-trimethoxysilane-2-bromo-2-methylpropionate to ethanol aqueous solution is 4.8-5.6 g: 100 mL; the mass ratio of methyl 3-trimethoxysilane-2-bromo-2-methylpropionate to montmorillonite is 1: (1.2-1.6); the pH of the ethanol aqueous solution is 4-5, and the concentration is 90 wt%; the hydrolysis time is 4-5 h; and the heating reaction temperature is 70-75 °C, and the time is 20-24 h.

7. The environmentally friendly, wear-resistant water-based coating according to claim 5, characterized in that, In step B, the ratio of intermediate 2, diethyl p-[2-(diethylamino)-2-oxoethyl]phosphonate, and tetrahydrofuran is 1 g: 1.2-1.8 g: 10-20 mL; the heating reaction is carried out at a temperature of 50-55 °C for 36-42 h.

8. The environmentally friendly, wear-resistant water-based coating according to claim 5, characterized in that, In step C, the ratio of intermediate 3, trimethylbromosilane, and dichloromethane is 1g:6-9g:20-30mL; the stirring reaction time is 12-14h.

9. The environmentally friendly wear-resistant water-based coating according to claim 1, characterized in that, The curing agent is a hydrophilic aliphatic polyisocyanate; the defoamer is an organosilicon defoamer BYK-024; the leveling agent is BYK-410; and the dispersant is BYK-190.

10. The method for preparing the environmentally friendly wear-resistant water-based coating according to any one of claims 1-9, characterized in that, Includes the following steps: The modified acrylic emulsion and curing agent are mixed and stirred for 15-25 minutes. Then, functional fillers, dispersants, defoamers and leveling agents are added and stirred for 30-45 minutes to obtain the environmentally friendly wear-resistant water-based coating.

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