A preparation method of waterborne epoxy asphalt coating

Abstract

The present invention discloses a method for preparing a water-based epoxy asphalt coating and its application, belonging to the technical field of coating preparation. In view of the problems of poor compatibility and insufficient stability of existing water-based epoxy asphalt coatings, a performance breakthrough is achieved through a multi-component synergistic modification and a staged cross-linking process. The coating prepared by this method has excellent storage stability, adhesion of level 0, tensile strength ≥12.5MPa, significantly improved water resistance and corrosion resistance, and the all-water system is environmentally friendly and solvent-free. It is suitable for fields such as bridge steel structure anti-corrosion and road crack repair, and has both high performance and cost advantages.

Description

Technical Field

[0001] The present invention belongs to the technical field of coating preparation, and in particular relates to a preparation method of a water-based epoxy asphalt coating and an application thereof. Background Art

[0002] Asphalt coatings offer excellent waterproofing and corrosion resistance, making them widely used in construction, transportation, and other fields. However, traditional solvent-based asphalt coatings contain large amounts of organic solvents, which emit harmful gases during production and application, posing a threat to the environment and human health. With increasing environmental protection requirements, water-based asphalt coatings have become a research hotspot.

[0003] Waterborne epoxy asphalt coatings combine the high strength and adhesion of epoxy resin with the excellent waterproofing and anti-corrosion properties of asphalt, offering advantages such as environmental friendliness, safety, and ease of construction. However, current waterborne epoxy asphalt coatings face challenges during their preparation, such as poor compatibility between epoxy resin and asphalt, poor coating stability, and slow drying speed, which limit their application.

[0004] In order to solve these problems, people have conducted a lot of research. For example, by modifying epoxy resin to improve its compatibility with asphalt, patent document CN202411692304.9 adds acrylate copolymer to water-based epoxy resin coating, and combines epoxy resin, emulsifier and stabilizer for composite reaction to prepare epoxy composite resin emulsion, and further prepares water-based epoxy resin coating with enhanced toughness and improved hardness by mixing reaction with emulsified asphalt, curing agent and water. However, this method has a complex reaction process and high cost. At the same time, there may be certain problems with the compatibility of acrylate copolymer and epoxy resin. Phase separation may occur during the composite reaction and subsequent emulsion storage process, resulting in decreased emulsion stability.

[0005] People also add additives to improve the stability and drying speed of the coating. Patent document CN201710344313.2 uses polyvinyl alcohol, water glass and epoxy resin to synthesize epoxy-modified polyvinyl alcohol latex through a cross-linking modification process, which partially or completely replaces chloroprene latex or amino polyvinyl alcohol glue to prepare water glass and epoxy resin modified polyvinyl alcohol emulsified asphalt coating. However, during the storage of the epoxy-modified polyvinyl alcohol latex synthesized in this method, the water glass may undergo a slow secondary reaction with the polyvinyl alcohol and epoxy resin, resulting in a gradual increase in the viscosity of the latex system, and even the occurrence of gelation and precipitation, which reduces the storage life and performance of the latex. Summary of the Invention

[0006] The purpose of the present invention is to provide a method for preparing a water-based epoxy asphalt coating. The water-based epoxy asphalt coating prepared by the method is simple to prepare, has good compatibility, stability and drying speed, and has excellent waterproof and anti-corrosion properties.

[0007] In order to achieve the above object, the present application provides a method for preparing a waterborne epoxy asphalt coating, characterized in that:

[0008] The mass percentage components of the waterborne epoxy asphalt coating include:

[0009] Component A: water-based epoxy resin 30%-50%, water-based emulsified asphalt 20%-40%, modified nanofiller 5%-15%, defoamer 0.15%-0.25%, wetting agent 0.5%-2%, pH regulator 0.6%-0.8%, thickener 0.3%-0.5%, appropriate amount of water;

[0010] Component B: composite curing agent 5%-10%, dispersant 0.3%-0.5%, anti-settling agent 0.2%-0.3%, defoaming agent 0.15%-0.25%, appropriate amount of water;

[0011] Component C: 40%-60% water glass, 0.5%-2% wetting agent, 0.5%-2% photoenzyme, 1%-5% calcium bicarbonate, and appropriate amount of water;

[0012] The preparation method steps are:

[0013] To prepare component A, first add water, wetting agent, defoaming agent, and modified nanofiller to the paint mixing tank and disperse at a low speed for 5-30 minutes. Then add water-based epoxy resin and disperse at a medium speed for 5-30 minutes. Then add pH regulator to adjust the pH of the system to 9-10 and disperse for 1-10 minutes. Then add water-based emulsified asphalt and disperse at a low speed for 5-30 minutes. Finally, add thickener to adjust the viscosity and disperse at a low speed for another 5-30 minutes to prepare the required component A coating.

[0014] Prepare component B. First, add water, defoamer, dispersant, and anti-settling agent to the paint mixing tank according to the amount in the formula and disperse at low speed for 5-30 minutes. Then add the composite curing agent and disperse at medium-low speed for 10-30 minutes to prepare component B.

[0015] Prepare component C by first adding water glass, wetting agent and water into the paint mixing tank according to the amount in the formula and dispersing them at low speed for 5-30 minutes to obtain a premixed liquid, then adding calcium bicarbonate and light-controlled enzyme to obtain a prefabricated slurry, and dispersing it at medium-low speed for 10-30 minutes to prepare component C; the light-controlled enzyme is preferably a light-responsive metal-organic framework dynamic confined enzyme (PCN-224-CAT).

[0016] Component A and component B are mixed and stirred at low speed for 1-5 minutes to obtain a mixed solution, and then component C is added. The mixture is stirred for 1-5 minutes under light irradiation in the wavelength range of 320nm to 400nm, and then stirred for 5-30 minutes under light irradiation in the wavelength range of 450nm to 495nm to obtain a water-based epoxy asphalt coating. Component A and component B are first mixed, and the curing agent is preliminarily cross-linked with the epoxy resin to undergo a ring-opening addition reaction. At the same time, the emulsified asphalt particles form a preliminary physical entanglement with the resin through the synergistic effect of the compound emulsifier, forming a prototype of an "resin-asphalt" interpenetrating network. Then component C is added. When component C containing water glass is added to the preliminarily cross-linked epoxy asphalt coating, the water glass can accurately fill the resin-asphalt interface pores. At the same time, the preliminary network formed by pre-crosslinking provides attachment sites for water glass and light-controlled enzymes, thereby enhancing the interfacial adhesion between the components. The cross-linking reaction of water glass is controlled in stages by utilizing the characteristics of light-controlled enzymes under different wavelengths of light. The light-controlled enzymes are quickly activated under short-wavelength light (320-400nm) and catalyze the rapid cross-linking of water glass; the reaction stability is maintained under long-wavelength light (450-495nm) to ensure the uniform formation of the silicon-oxygen network. The reaction is first quickly activated by short-wavelength light, and then long-wavelength light is used to ensure the reaction stability. At the same time, calcium bicarbonate (Ca(HCO3)2) decomposes to release Ca2 + and HCO3 - , Ca2 + Combined with silicate to form calcium silicate (CaSiO3), which enhances the mechanical strength of the cross-linked network; at the same time, HCO3 - By adjusting the pH of the system and optimizing the reaction conditions, the uniform and dense silicon-oxygen network structure formed by the water glass after curing can effectively block the erosion of epoxy asphalt coatings by external factors such as ultraviolet rays, moisture, and oxygen, fundamentally solving the problems of stratification and precipitation during coating storage, and greatly improving the stability of the coating; and forming a uniform and dense cross-linked structure after film formation, which significantly enhances the mechanical properties of the coating such as adhesion, tensile strength, and elongation at break, while improving the protective properties such as waterproofing, acid and alkali resistance, and anti-aging, which can meet the long-term use requirements under complex working conditions in construction, transportation and other fields.

[0017] Furthermore, the modified nanofiller is nanosilica modified with a silane coupling agent, with a particle size of 20-50 nm. Modifying the nanosilica with a silane coupling agent, such as KH-550, and adding it to a water-based epoxy resin emulsion effectively improves the dispersibility of the nanosilica in the coating system. The modified nanosilica can be evenly distributed within the coating, forming a three-dimensional network reinforcement structure, like building countless microscopic "rebars" in the coating. These interact with the epoxy resin and asphalt, significantly improving the mechanical strength of the coating and making it more resistant to damage when subjected to external impact and wear. The addition and modification of nano-silica greatly enhances the corrosion resistance of the coating. On the one hand, nano-silica has a smaller particle size and a larger specific surface area, which can fill the pores and defects in the coating to form a dense shielding layer, effectively blocking the penetration of corrosive media (such as moisture, oxygen, salt ions, etc.); on the other hand, after modification with silane coupling agent, a strong chemical bond is formed between nano-silica and the coating matrix, which further improves the stability of the coating, delays the occurrence of corrosion reactions, and extends the service life of the coating.

[0018] Furthermore, the composite curing agent is a polyamide curing agent compounded with dicyandiamide at a mass ratio of 1-3:1. This curing system, which uses an amine curing agent and dicyandiamide as a curing agent, achieves the dual effects of rapid room temperature curing and high-temperature deep crosslinking of the waterborne epoxy asphalt coating, significantly improving the overall performance and construction adaptability of the coating.

[0019] Furthermore, the water-based emulsified asphalt is emulsified using nonionic and anionic emulsifiers, with the two emulsifiers compounded in a mass ratio of 2-3:1. This specific mass ratio of 2-3:1 leverages the synergistic effect of the two emulsifiers, effectively reducing the interfacial tension between the asphalt and epoxy resin, enhancing the intermolecular interaction between the two, and significantly improving their compatibility. This reduces delamination and sedimentation during storage, significantly improving stability. During film formation, a uniform, dense coating structure is formed, enhancing the overall performance of the coating.

[0020] Furthermore, the pH regulator is one or more of ammonia water, sodium hydroxide, and potassium hydroxide.

[0021] Furthermore, the defoaming agent is one or more of an organosilicon defoaming agent and a polyether defoaming agent.

[0022] Furthermore, the thickener is one or more of hydroxyethyl cellulose, hydroxypropyl cellulose, and polyacrylate thickener.

[0023] Furthermore, the wetting agent is one or more of polyethylene glycol, sodium lauryl sulfate, Tween series or silane coupling agent.

[0024] The present invention also provides an application of the coating prepared by the above method in anti-corrosion of bridge steel structures or repairing of road cracks.

[0025] Beneficial effects of the present invention:

[0026] (1) After the water-based epoxy resin and emulsified asphalt are initially cured and cross-linked, component C containing water glass is added. The water glass is cured to form a silicon-oxygen network structure, which fills the pores between the epoxy resin and the asphalt, enhances the interfacial bonding force, and improves the adhesion of the coating. By utilizing the characteristics of light-controlled enzymes under different wavelengths of light, the cross-linking reaction of the water glass is controlled in stages. First, the reaction is quickly activated by short-wavelength light, and then long-wavelength light is used to ensure the stability of the reaction, which greatly improves the performance of the coating in all aspects.

[0027] (2) The performance of the multi-component synergistic enhancement system is improved by using nano-silica modified with silane coupling agent, which forms a three-dimensional network structure after uniform dispersion, significantly improving the mechanical strength (tensile strength, elongation at break) and corrosion resistance of the coating, and effectively blocking the penetration of moisture and salt ions; polyamide curing agent and latent dicyandiamide are compounded in a ratio of 2:1, taking into account rapid curing at room temperature (rapid ring-opening reaction of polyamide) and deep crosslinking at high temperature (dicyandiamide releases active groups at high temperature), shortening the drying time, and at the same time improving the hardness and chemical corrosion resistance of the coating; water-based emulsified asphalt uses non-ionic (fatty alcohol polyoxyethylene ether) and anionic (sodium dodecylbenzene sulfonate) emulsifiers in a ratio of 3:1 to reduce interfacial tension, enhance the intermolecular interaction between epoxy resin and asphalt, solve the problems of stratification and precipitation in storage of traditional coatings, and greatly improve stability.

[0028] (3) The all-water-based system does not contain organic solvents, and no harmful gases are emitted during the production and construction process, meeting environmental protection requirements and being suitable for indoor and outdoor use and sensitive environments. Raw materials such as water glass and nano-silica are inexpensive, and compounding technology can be used to reduce the amount of expensive additives, thereby reducing production costs and improving the cost-effectiveness of the coating. DETAILED DESCRIPTION

[0029] The present application is described in further detail below. It is necessary to point out that the following specific implementation methods are only used to further illustrate the present application and cannot be understood as limiting the scope of protection of the present application. Technicians in this field can make some non-essential improvements and adjustments to the present application based on the above application content.

[0030] 1. Materials and Methods

[0031] Unless otherwise specified, the methods used in this example are conventional methods known to those skilled in the art, and the reagents and other materials used are commercially available products unless otherwise specified.

[0032] Example 1

[0033] (1) Formulation (mass percentage)

[0034] Component A: 40% water-based epoxy resin, 30% water-based emulsified asphalt, 10% modified nano-silica (KH-550 modified, 20nm), 0.2% silicone defoamer, 1% Tween-80 (wetting agent), 0.7% ammonia water (pH regulator), 0.4% hydroxyethyl cellulose (thickener), and the balance is water.

[0035] Component B: polyamide 650 and dicyandiamide (mass ratio 2:1) composite curing agent 8%, polyether defoamer 0.2%, dispersant (sodium hexametaphosphate) 0.4%, anti-settling agent (organic bentonite BS-1C) 0.25%, and the balance is water.

[0036] Component C: 55% water glass, 1.5% sodium lauryl sulfate (wetting agent), 1% metal organic framework dynamic confined enzyme (PCN-224-CAT), 3% calcium bicarbonate, and the balance is water.

[0037] (2) Preparation steps

[0038] Preparation of component A: Add water, Tween-80, silicone defoamer, and modified nano-silica to the paint mixing tank and disperse at low speed (200 r / min) for 15 minutes; add water-based epoxy resin and disperse at medium speed (400 r / min) for 20 minutes; add ammonia water to adjust the pH to 9.5 and disperse for 5 minutes; add water-based emulsified asphalt (non-ionic and anionic emulsifiers are compounded in a mass ratio of 3:1) and disperse at medium-low speed (300 r / min) for 20 minutes; add hydroxyethyl cellulose to adjust the viscosity and disperse at low speed for 15 minutes.

[0039] Preparation of component B: Add water, polyether defoamer, dispersant and anti-settling agent to the paint mixing tank and disperse at low speed for 10 minutes; add composite curing agent and disperse at medium-low speed (300r / min) for 20 minutes.

[0040] Preparation of component C: Add water glass, sodium lauryl sulfate and water to the paint mixing tank and disperse at low speed for 15 minutes; add calcium bicarbonate and metal organic framework dynamic confined enzyme (PCN-224-CAT) and disperse at medium-low speed (300r / min) for 20 minutes.

[0041] Mixing and photo-controlled cross-linking: Component A and component B were mixed and stirred at a low speed (100 r / min) for 3 minutes; component C was added and first irradiated with 365 nm short-wavelength light, stirred at 150 r / min, and reacted for 3 minutes; then switched to 460 nm long-wavelength light for irradiation, stirred at 200 r / min, and reacted for 15 minutes to obtain the coating.

[0042] Comparative Example 1

[0043] The "modified nano-silica" in component A was replaced with unmodified nano-silica (20 nm), and the rest was consistent with Example 1.

[0044] Comparative Example 2

[0045] The "composite curing agent" in component B was replaced with a single polyamide 650 (without dicyandiamide) in an amount of 8%. The rest was the same as in Example 1.

[0046] Comparative Example 3

[0047] The ratio of the polyamide curing agent to dicyandiamide in component B was changed to 0.5:1, and the rest was the same as in Example 1.

[0048] Comparative Example 4

[0049] The ratio of polyamide curing agent to dicyandiamide in component B was changed to 4:1, and the rest was consistent with Example 1.

[0050] Comparative Example 5

[0051] The emulsifier of the aqueous emulsified asphalt was replaced with a single non-ionic emulsifier, and the rest was the same as in Example 1.

[0052] Comparative Example 6

[0053] The ratio of nonionic to anionic emulsifiers in the water-based emulsified asphalt was changed to 1:1, and the rest was the same as in Example 1.

[0054] Comparative Example 7

[0055] The ratio of nonionic to anionic emulsifiers in the water-based emulsified asphalt was changed to 4:1, and the rest was the same as in Example 1.

[0056] Comparative Example 8

[0057] Only the short-wavelength irradiation of 365 nm was performed, and the long-wavelength irradiation of 460 nm was not performed. The rest was the same as in Example 1.

[0058] Comparative Example 9

[0059] Only the long-wavelength irradiation of 460 nm was performed, and the short-wavelength irradiation of 365 nm was not performed. The rest was the same as in Example 1.

[0060] Comparative Example 10

[0061] First, long-wavelength irradiation of 460 nm is performed, and then short-wavelength irradiation of 365 nm is performed. The rest is the same as in Example 1.

[0062] Comparative Example 11

[0063] The "light-controlled enzyme" in component C was removed, and the other components remained unchanged. No light cross-linking was performed after mixing. The rest was consistent with Example 1.

[0064] Comparative Example 12

[0065] Components A and B are not pre-crosslinked. Components A, B, and C are directly mixed together at the same time. The rest is the same as in Example 1.

[0066] Table 1 shows the performance parameters of the coatings in Example 1 and Comparative Examples 1-11. The test methods for each performance parameter are detailed in the Test Methods for Building Waterproof Coatings (GB / T 16777-2008).

[0067] Table 1

[0068]

[0069] Through the experimental data of Example 1 and Comparative Example 1, we can see that compared with Example 1, the tensile strength of Comparative Example 1 is reduced from 12.5 MPa to 8.2 MPa, the elongation at break is reduced from 48% to 32%, and the corrosion resistance is also reduced. It can be seen that the nano-silica modified by the silane coupling agent forms a chemical bond with the epoxy resin / asphalt through a silicon-oxygen bond, forming a three-dimensional network reinforcement structure inside the coating, such as a "micro-steel bar" supporting the matrix, thereby improving the mechanical strength; the unmodified nano-silica has poor dispersibility in the aqueous system due to the unmodified surface hydrophilic groups, is easy to agglomerate, and only physically fills the pores, and cannot form effective chemical bonds, resulting in a significant decrease in strength and corrosion resistance.

[0070] The experimental data from Example 1 and Comparative Examples 2-4 show that in Comparative Example 2, the dry time of polyamide 650 alone was prolonged and the corrosion resistance was reduced due to insufficient crosslinking density of the coating due to the lack of high-temperature crosslinking with dicyandiamide. In Comparative Example 3, the polyamide:dicyandiamide ratio was 0.5:1, resulting in deteriorated storage stability, moderate delamination, and prolonged surface-free time. Excessive dicyandiamide hindered the room-temperature reaction. In Comparative Example 4, the polyamide:dicyandiamide ratio was 4:1, resulting in a shortened dry time but reduced water resistance. This may be related to the loosening of the crosslinking network caused by the excessive polyamide. The specific combination of polyamide 650 (room-temperature fast-drying) and dicyandiamide (high-temperature deep crosslinking) achieves "room-temperature rapid film formation + high-temperature densification," which not only meets construction efficiency but also improves the chemical resistance of the coating through secondary crosslinking of the cyanamide groups of dicyandiamide with the epoxy groups.

[0071] It can be seen from Example 1 and Comparative Examples 5-7 that Comparative Example 5 (single non-ionic type) has the worst storage stability (obvious stratification) and its adhesion is reduced to level 2. Due to the lack of the electrostatic repulsion of the anionic emulsifier, the interfacial tension between the asphalt and the resin particles is high and the compatibility is poor; Comparative Examples 6 / 7 (1:1 / 4:1): The performance is between that of Example 1 and Comparative Example 5. At a ratio of 3:1, the synergistic effect of the nonionic type (steric hindrance) and the anionic type (electrostatic repulsion) is the best. This is because the nonionic type (such as fatty alcohol polyoxyethylene ether) provides a hydration film and the anionic type (such as sodium dodecylbenzene sulfonate) provides negative charge repulsion. The 3:1 ratio balances the two forces, making the stability of the asphalt and epoxy resin emulsion optimal.

[0072] It can be seen from Example 1 and Comparative Examples 8-11 that in Comparative Example 8, only short-wave irradiation is used, and the water resistance decreases, because only short-wave (365nm) quickly activates the photosensitizer and then does not pass through the long-wave (460nm) to stabilize the reaction, and the cross-linking network is incomplete; in Comparative Example 9, only long-wave irradiation is used, the surface drying time is prolonged, the photosensitizer is not effectively activated, and the reaction rate is reduced; in Comparative Example 10, the order of long-wave and short-wave is reversed, and the adhesion is reduced to level 1. The long-wave followed by the short-wave leads to the premature passivation of the enzyme active center and the reduction of cross-linking sites; in Comparative Example 11, there is no photosensitizer and light, and the performance deteriorates comprehensively, the storage stratification is serious, and the corrosion resistance completely fails, which confirms that the staged cross-linking of photosensitizers is the core mechanism for forming the silicon-oxygen network and dense coating.

[0073] It can be seen from Example 1 and Comparative Example 12 that if A, B, and C are directly mixed without pre-crosslinking and curing components A and B, the adhesion strength, tensile strength, elongation at break, water resistance, and corrosion resistance of the coating are all reduced to varying degrees. This is because after component A (water-based epoxy resin + emulsified asphalt) and component B (composite curing agent) are pre-mixed, the curing agent first undergoes preliminary cross-linking and ring-opening addition reaction with the epoxy resin. At the same time, the emulsified asphalt particles form preliminary physical entanglement with the resin through the synergistic effect of the compounded emulsifier, forming a prototype of an interpenetrating network of "resin-asphalt". The preliminary network formed by pre-crosslinking provides attachment sites for water glass and light-controlled enzymes, so that water glass can accurately fill the resin-asphalt interface pores. In Comparative Example 12, water glass is randomly distributed in the coating due to lack of skeleton support, forming invalid agglomerations, and cannot effectively enhance the interfacial adhesion.

[0074] The above-described embodiments merely illustrate several implementations of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous improvements without departing from the scope of the present invention, and such improvements are all within the scope of protection of the present invention.

Claims

1. A method for preparing a waterborne epoxy asphalt coating, characterized in that: The mass percentage components of the waterborne epoxy asphalt coating include: Component A: water-based epoxy resin 30%-50%, water-based emulsified asphalt 20%-40%, modified nanofiller 5%-15%, defoamer 0.15%-0.25%, wetting agent 0.5%-2%, pH adjuster 0.6%-0.8%, thickener 0.3%-0.5%, appropriate amount of water; Component B: composite curing agent 5%-10%, dispersant 0.3%-0.5%, anti-settling agent 0.2%-0.3%, defoaming agent 0.15%-0.25%, appropriate amount of water; Component C: 40%-60% water glass, 0.5%-2% wetting agent, 0.5%-2% photosensitizer, 1%-5% calcium bicarbonate, and appropriate amount of water; the photosensitizer is a light-responsive metal-organic framework dynamically confined enzyme; The preparation method steps are: To prepare component A, first add water, wetting agent, defoaming agent, and modified nanofiller to the paint mixing tank and disperse at a low speed for 5-30 minutes, then add water-based epoxy resin and disperse at a medium speed for 5-30 minutes, then add pH regulator to adjust the pH of the system to 9-10 and disperse for 1-10 minutes, then add water-based emulsified asphalt and disperse at a low speed for 5-30 minutes, finally add thickener to adjust the viscosity, and then disperse at a low speed for 5-30 minutes to prepare the required component A coating; Prepare component B by adding water, defoamer, dispersant, and anti-settling agent to the paint mixing tank according to the amount in the formula and dispersing at low speed for 5-30 minutes. Then add the composite curing agent and disperse at medium-low speed for 10-30 minutes to prepare component B. Prepare component C by first adding water glass, wetting agent and water to a paint mixing tank according to the amount in the formula and dispersing at low speed for 5-30 minutes to obtain a premixed solution. Then add calcium bicarbonate and light-controlled enzyme to obtain a prefabricated slurry and disperse at medium-low speed for 10-30 minutes to prepare component C. Component A and component B are mixed and stirred at a low speed for 1-5 minutes to obtain a mixed solution, and then component C is added and stirred for 1-5 minutes under irradiation with light having a wavelength range of 320 nm to 400 nm, and then stirred for 5-30 minutes under irradiation with a wavelength of 450 nm to 495 nm to obtain a waterborne epoxy asphalt coating; The modified nanofiller is nano-silica modified by a silane coupling agent, and has a particle size of 20-50 nm; The composite curing agent is a polyamide curing agent and dicyandiamide compounded in a mass ratio of 1-3:1; Water-based emulsified asphalt is emulsified by non-ionic and anionic emulsifiers, and the non-ionic and anionic emulsifiers are compounded in a mass ratio of 2-3:

1.

2. The method according to claim 1, characterized in that The pH regulator is one or more of ammonia water, sodium hydroxide and potassium hydroxide.

3. The method according to claim 1, characterized in that The defoaming agent is one or more of an organosilicon defoaming agent and a polyether defoaming agent.

4. The method according to claim 1, wherein The thickener is one or more of hydroxyethyl cellulose, hydroxypropyl cellulose and polyacrylate thickener.

5. The method according to claim 1, characterized in that The wetting agent is one or more of polyethylene glycol, sodium lauryl sulfate, Tween series or silane coupling agent.

6. Use of a coating prepared by the method according to any one of claims 1 to 5 in corrosion protection of bridge steel structures or repair of road cracks.

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