Waterborne epoxy resin coating, preparation method and application in bridge protection

Abstract

The invention discloses a waterborne epoxy resin coating, a preparation method and application in bridge protection, and belongs to the technical field of coatings. The water-borne epoxy resin coating comprises the following raw material components in parts by weight: 15-25 parts of epoxy composite resin emulsion, 100 parts of emulsified asphalt, 3-5 parts of a curing agent and 6-10 parts of water, wherein the epoxy composite resin emulsion is obtained by carrying out a composite reaction on 30-60 parts by mass of epoxy resin, 2-3 parts by mass of an emulsifier, 6-9 parts by mass of an acrylate composition and 1.4-1.6 parts by mass of a co-stabilizer; the acrylate composition is prepared by prepolymerizing 15 to 16 parts by mass of butyl methacrylate, 10 to 12 parts by mass of 2-isopropenyl aniline, 5 to 7 parts by mass of allyl glycidyl ether and 1 to 1.2 parts by mass of allyl polyhedral oligomeric silsesquioxane and then combining the prepolymerized materials with 1 to 3 parts by mass of acrylic acid.

Description

Technical Field

[0001] The invention relates to a water-based epoxy resin coating, a preparation method thereof and application thereof in bridge protection. Background Art

[0002] With the rapid development of transportation infrastructure construction, bridges, as important transportation hubs connecting different geographical areas, are particularly important for their long-term stability and safety. The durability and protective performance of bridge structures directly affect the service life and maintenance cost of bridges. Among many protective materials, emulsified asphalt is widely used in road surface repair and preventive maintenance due to its good waterproof performance and construction convenience. However, ordinary emulsified asphalt has some significant limitations, such as low bonding strength, brittleness under low temperature conditions, and slow strength formation. These shortcomings limit its application effect under harsh environmental conditions.

[0003] In order to overcome the above problems, researchers are committed to modifying emulsified asphalt through various methods to improve its maintenance effect and construction efficiency. In recent years, water-based epoxy resin has been introduced into asphalt materials as an environmentally friendly modifier. Asphalt modified with water-based epoxy resin not only performs well in terms of bonding performance, high temperature stability and curing time, but also effectively avoids the volatile organic compound (VOC) emission problem existing in traditional solvent-based materials because its dispersion medium is water. It meets the requirements of current environmental protection policies and is a sustainable material modification solution.

[0004] Despite this, traditional water-based epoxy resins still face some challenges in practical applications, especially when they form a coating, they are prone to brittleness and easy fracture, which greatly limits their application in situations that require high strength and high impact toughness. In order to solve this problem, researchers have tried to add acrylate copolymers to water-based epoxy resin coatings to improve the flexibility and impact resistance of the coating. However, this approach also brings new problems, namely, the hardness of the coating will be reduced accordingly, resulting in poor wear resistance.

[0005] Therefore, the present invention provides a water-based epoxy resin coating, a preparation method thereof and application thereof in bridge protection. Summary of the invention

[0006] The purpose of the present invention is to provide a water-based epoxy resin coating and a preparation method thereof and application in bridge protection, so as to solve the technical problems mentioned in the above background technology.

[0007] The technical solution for achieving the purpose of the present invention is:

[0008] A water-based epoxy resin coating comprises, by weight, raw material components: 15 to 25 parts by weight of epoxy composite resin emulsion, 100 parts by weight of emulsified asphalt, 3 to 5 parts by weight of curing agent, and 6 to 10 parts by weight of water.

[0009] Furthermore, the epoxy composite resin emulsion is obtained by a composite reaction of 30 to 60 parts by mass of epoxy resin, 2 to 3 parts by mass of emulsifier, 6 to 9 parts by mass of acrylate composition, and 1.4 to 1.6 parts by mass of stabilizer.

[0010] Furthermore, the acrylic ester composition is obtained by prepolymerizing 15 to 16 parts by mass of butyl methacrylate, 10 to 12 parts by mass of 2-isopropenylaniline, 5 to 7 parts by mass of allyl glycidyl ether, and 1 to 1.2 parts by mass of allyl cage-type polyhedral oligomeric silsesquioxane and then combining them with 1 to 3 parts by mass of acrylic acid.

[0011] Furthermore, the curing agent is obtained by combining meta-phenylenediamine and meta-phenylenediamine.

[0012] The present invention also provides a method for preparing a water-based epoxy resin coating, comprising the following preparation steps:

[0013] Add 100 parts by mass of emulsified asphalt and 15-25 parts by mass of epoxy composite resin emulsion into a stirrer, pour 3-5 parts by mass of curing agent into 6-10 parts by mass of water to dilute and add to the stirrer, stir thoroughly for 20-40 minutes at room temperature, then cool to 0-4°C, add initiator ammonium persulfate mixed solution dropwise at 2-4 drops / s, continue stirring and reacting for 1-6 hours to obtain a water-based epoxy resin coating.

[0014] Furthermore, the preparation steps of the epoxy composite resin emulsion are as follows: 30 to 60 parts by weight of epoxy resin, 1 to 3 parts by weight of acrylic acid, acrylate prepolymer, and 1.4 to 1.6 parts by weight of hexadecane are stirred at 300 to 500 rpm for 10 to 20 minutes at room temperature, and then oxidative initiator ammonium persulfate and di-tert-butyl peroxide are added and stirred for 8 to 12 minutes, and then an aqueous solution of an emulsifier is added and stirred at 400 to 600 rpm for 25 to 35 minutes, and then stirred at 1 The pre-emulsion was sheared at 000-2000rpm for 14-16min, and a high-pressure homogenizer was used for high-pressure homogenization at 80MPa for 2-4 times to obtain a pre-emulsion; 25% of the pre-emulsion and 25% of the reducing initiator were mixed, the temperature was raised to 58-62°C, and the remaining 75% of the pre-emulsion and 75% of the reducing initiator were added separately using a peristaltic pump, and the addition was completed within 55-65min, and then under nitrogen protection, the polymerization reaction was carried out at 58-62°C for 4-6h to obtain an epoxy composite resin emulsion.

[0015] Furthermore, the preparation steps of the acrylate prepolymer are as follows: toluene and butyl acetate are mixed in a mass ratio of 1:1 to obtain a mixed solvent; 10 parts by mass of the mixed solvent are taken, the temperature is raised to 44-46°C, and then 15-16 parts by mass of butyl methacrylate, 10-12 parts by mass of 2-isopropenylaniline, 5-7 parts by mass of allyl glycidyl ether, 0.15-0.17 parts by mass of azoisobutyronitrile, and 1-1.2 parts by mass of allyl cage-type polyhedral oligomeric silsesquioxane are added to obtain solution A; 1 / 3 of solution A and 24-26 parts by mass of the mixed solvent are mixed, and the temperature is raised to 80°C, and after constant temperature stirring for 20 minutes, the remaining 2 / 3 of solution A and 0.15-0.17 parts by mass of thioglycolic acid are added dropwise at 2-4 drops / s, and after the addition is completed, the reaction is continued to be kept warm for 4 hours, and finally the solvent and monomers not participating in the reaction are removed by rotary evaporation to obtain an acrylate prepolymer.

[0016] Furthermore, the preparation step of the ammonium persulfate mixed solution is as follows: 6 to 7 parts by mass of ammonium persulfate are uniformly dispersed in 20 parts by mass of 1M hydrochloric acid solution to obtain the ammonium persulfate mixed solution.

[0017] Furthermore, the curing agent is obtained by combining meta-phenylenediamine and meta-phenylenediamine in a mass ratio of 1:2 to 4.

[0018] The present invention also provides an application method of water-based epoxy resin coating in bridge protection, and the specific steps are as follows: 0.1 to 0.2 times the mass of the water-based epoxy resin coating is mixed into cement mortar, and then filled in the damaged parts of the bridge deck that need to be repaired.

[0019] By adopting the above technical solution, the present invention has the following beneficial effects:

[0020] The waterborne epoxy resin coating of the present invention comprises raw material components: epoxy composite resin emulsion, emulsified asphalt, curing agent and water; wherein the epoxy composite resin emulsion is obtained by composite reaction of epoxy resin, emulsifier, acrylate composition and stabilizer; the acrylate composition is obtained by prepolymerizing butyl methacrylate, 2-isopropenylaniline, allyl glycidyl ether and allyl cage-type polyhedral oligomeric silsesquioxane and then combining them with acrylic acid.

[0021] Firstly, butyl methacrylate, 2-isopropenylaniline, allyl glycidyl ether and allyl cage type polyhedral oligomeric silsesquioxane are prepolymerized through unsaturated bond copolymerization and then combined with acrylic acid to obtain an acrylate composition, and then the acrylate composition is composited with epoxy resin and emulsifier and stabilizer to obtain an epoxy composite resin emulsion; the carboxyl group of acrylic acid is reacted and grafted with the epoxy group on the epoxy resin, the acrylate prepolymer is grafted with acrylic acid through unsaturated bond polymerization, and the acrylate is grafted onto the epoxy resin, which has a toughening effect on the waterborne epoxy resin coating, but also reduces the surface hardness of the waterborne epoxy resin coating, and the introduction of the rigid benzene ring of 2-isopropenylaniline and the unique three-dimensional cage-like rigid structure of the allyl cage type polyhedral oligomeric silsesquioxane help to improve the problem of poor hardness of the coating.

[0022] Secondly, epoxy composite resin emulsion, emulsified asphalt, curing agent and water are mixed to react to prepare water-based epoxy resin coating, wherein the curing agent is obtained by combining m-phenylenediamine and m-phenylenediamine; compounding epoxy composite resin emulsion and emulsified asphalt can improve the bonding strength of emulsified asphalt, and has good compatibility with ordinary emulsified asphalt and good dispersibility in emulsified asphalt; aniline in epoxy composite resin emulsion and m-phenylenediamine in curing agent are polymerized under the action of initiator ammonium persulfate mixed solution to form a polyaniline network that is uniformly interspersed in the polymer network of the coating, thereby increasing the crosslinking density of the water-based epoxy resin coating, while polyaniline enhances ionic resistance by providing positive charge, which can prevent H 3 O + Migrate to the cathode area, inhibit the corrosion reaction, and achieve corrosion resistance. DETAILED DESCRIPTION

[0023] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with specific implementation methods.

[0024] The following embodiments are only used to more clearly illustrate the technical solutions of the present invention, and are not intended to limit the protection scope of the present invention.

[0025] Some of the raw material components of the embodiments of the present invention and the comparative examples are as follows:

[0026] The emulsified asphalt adopts BCR emulsified asphalt produced by Mianyang Zhonghe High-Tech Asphalt Equipment Co., Ltd.

[0027] The emulsifier is styrylphenol polyoxyethylene ether;

[0028] The epoxy resin is bisphenol A epoxy resin E51.

[0029] (Example 1)

[0030] A method for preparing a water-based epoxy resin coating comprises the following preparation steps:

[0031] 100 parts by mass of emulsified asphalt and 15 parts by mass of epoxy composite resin emulsion were added into a stirrer, 3 parts by mass of curing agent were diluted into 6 parts by mass of water and added into the stirrer and stirred thoroughly for 20 minutes at room temperature, then cooled to 0°C, initiator ammonium persulfate mixed solution was added dropwise at 2 drops / s, and the stirring reaction was continued for 1 hour to obtain a water-based epoxy resin coating.

[0032] The preparation steps of the epoxy composite resin emulsion are as follows: 30 parts by mass of epoxy resin, 1 part by mass of acrylic acid, acrylate prepolymer and 1.4 parts by mass of hexadecane are stirred at 300 rpm for 10 minutes at room temperature, then the oxidative initiator ammonium persulfate and di-tert-butyl peroxide are added and the stirring is continued for 8 minutes, then the aqueous solution of the emulsifier is added and stirred at 400 rpm for 25 minutes, and then sheared at 1000 rpm for 14 minutes, and a high-pressure homogenizer is used for high-pressure homogenization twice at 80 MPa to obtain a pre-emulsion; 25% of the pre-emulsion and 25% of the reducing initiator are mixed, the temperature is raised to 58°C, and the remaining 75% of the pre-emulsion and 75% of the reducing initiator are added respectively by a peristaltic pump, and the addition is completed within 55 minutes, and then under nitrogen protection, polymerization reaction is carried out at 58°C for 4 hours to obtain the epoxy composite resin emulsion.

[0033] The preparation steps of the acrylate prepolymer are as follows: toluene and butyl acetate are mixed in a mass ratio of 1:1 to obtain a mixed solvent; 10 parts by mass of the mixed solvent are taken, the temperature is raised to 44° C., and then 15 parts by mass of butyl methacrylate, 10 parts by mass of 2-isopropenylaniline, 5 parts by mass of allyl glycidyl ether, 0.15 parts by mass of azoisobutyronitrile, and 1 part by mass of allyl cage-type polyhedral oligomeric silsesquioxane are added to obtain a solution A; 1 / 3 of the solution A is mixed with 24 parts by mass of the mixed solvent, and the temperature is raised to 80° C., and after constant temperature stirring for 20 minutes, the remaining 2 / 3 of the solution A and 0.15 parts by mass of thioglycolic acid are added dropwise at a rate of 2 drops / s, and after the addition is completed, the reaction is continued by keeping the temperature for 4 hours, and finally the solvent and the monomers not participating in the reaction are removed by rotary evaporation to obtain an acrylate prepolymer.

[0034] The preparation steps of the ammonium persulfate mixed solution are as follows: 6 parts by mass of ammonium persulfate are uniformly dispersed in 20 parts by mass of 1M hydrochloric acid solution to obtain the ammonium persulfate mixed solution.

[0035] The curing agent is obtained by combining m-phenylenediamine and m-phenylenediamine in a mass ratio of 1:2.

[0036] (Example 2)

[0037] A method for preparing a water-based epoxy resin coating comprises the following preparation steps:

[0038] 100 parts by mass of emulsified asphalt and 20 parts by mass of epoxy composite resin emulsion were added into a stirrer, 4 parts by mass of curing agent were diluted into 8 parts by mass of water and added into the stirrer and stirred thoroughly for 30 minutes at room temperature, then cooled to 2°C, initiator ammonium persulfate mixed solution was added dropwise at 3 drops / s, and the stirring reaction was continued for 4 hours to obtain a water-based epoxy resin coating.

[0039] The preparation steps of the epoxy composite resin emulsion are as follows: 45 parts by mass of epoxy resin, 2 parts by mass of acrylic acid, acrylate prepolymer and 1.5 parts by mass of hexadecane are stirred at 400 rpm for 15 minutes at room temperature, then the oxidative initiator ammonium persulfate and di-tert-butyl peroxide are added and the stirring is continued for 10 minutes, then the aqueous solution of the emulsifier is added and stirred at 500 rpm for 30 minutes, and then sheared at 1500 rpm for 15 minutes, and a high-pressure homogenizer is used for high-pressure homogenization at 80 MPa for 3 times to obtain a pre-emulsion; 25% of the pre-emulsion and 25% of the reducing initiator are mixed, the temperature is raised to 60°C, and the remaining 75% of the pre-emulsion and 75% of the reducing initiator are added respectively by a peristaltic pump, and the addition is completed within 60 minutes, and then under nitrogen protection, polymerization reaction is carried out at 60°C for 5 hours to obtain the epoxy composite resin emulsion.

[0040] The preparation steps of the acrylate prepolymer are as follows: toluene and butyl acetate are mixed in a mass ratio of 1:1 to obtain a mixed solvent; 10 parts by mass of the mixed solvent are taken, heated to 45°C, and then 15.5 parts by mass of butyl methacrylate, 11 parts by mass of 2-isopropenylaniline, 6 parts by mass of allyl glycidyl ether, 0.16 parts by mass of azoisobutyronitrile, and 1.1 parts by mass of allyl cage-type polyhedral oligomeric silsesquioxane are added to obtain solution A; 1 / 3 of solution A and 25 parts by mass of the mixed solvent are mixed, and the mixture is heated to 80°C, stirred at a constant temperature for 20 minutes, and then the remaining 2 / 3 of solution A and 0.16 parts by mass of thioglycolic acid are added dropwise at a rate of 3 drops / s, and after the addition is completed, the mixture is kept warm for reaction for 4 hours, and finally the solvent and monomers not involved in the reaction are removed by rotary evaporation to obtain the acrylate prepolymer.

[0041] The preparation steps of the ammonium persulfate mixed solution are as follows: 6.5 parts by mass of ammonium persulfate are uniformly dispersed in 20 parts by mass of 1M hydrochloric acid solution to obtain the ammonium persulfate mixed solution.

[0042] The curing agent is obtained by combining m-phenylenediamine and m-phenylenediamine in a mass ratio of 1:3.

[0043] (Example 3)

[0044] A method for preparing a water-based epoxy resin coating comprises the following preparation steps:

[0045] 100 parts by mass of emulsified asphalt and 25 parts by mass of epoxy composite resin emulsion were added into a stirrer, 5 parts by mass of curing agent were diluted into 10 parts by mass of water and added into a stirrer, and stirred for 40 minutes at room temperature. Then the temperature was lowered to 4°C, and the initiator ammonium persulfate mixed solution was added dropwise at a rate of 4 drops / s. The stirring reaction was continued for 6 hours to obtain a water-based epoxy resin coating.

[0046] The preparation steps of the epoxy composite resin emulsion are as follows: 60 parts by mass of epoxy resin, 3 parts by mass of acrylic acid, acrylate prepolymer and 1.6 parts by mass of hexadecane are stirred at 500 rpm for 20 minutes at room temperature, then the oxidative initiator ammonium persulfate and di-tert-butyl peroxide are added and the stirring is continued for 12 minutes, then the aqueous solution of the emulsifier is added and stirred at 600 rpm for 35 minutes, then sheared at 2000 rpm for 16 minutes, and high-pressure homogenized 4 times at 80 MPa using a high-pressure homogenizer to obtain a pre-emulsion; 25% of the pre-emulsion and 25% of the reducing initiator are mixed, the temperature is raised to 62°C, and the remaining 75% of the pre-emulsion and 75% of the reducing initiator are added respectively using a peristaltic pump, and the addition is completed within 65 minutes, and then polymerization is carried out at 62°C for 6 hours under nitrogen protection to obtain the epoxy composite resin emulsion.

[0047] The preparation steps of the acrylate prepolymer are as follows: toluene and butyl acetate are mixed in a mass ratio of 1:1 to obtain a mixed solvent; 10 parts by mass of the mixed solvent are taken, the temperature is raised to 46°C, and then 16 parts by mass of butyl methacrylate, 12 parts by mass of 2-isopropenylaniline, 7 parts by mass of allyl glycidyl ether, 0.17 parts by mass of azoisobutyronitrile, and 1.2 parts by mass of allyl cage-type polyhedral oligomeric silsesquioxane are added to obtain a solution A; 1 / 3 of the solution A is mixed with 26 parts by mass of the mixed solvent, and the temperature is raised to 80°C. After constant temperature stirring for 20 minutes, the remaining 2 / 3 of the solution A and 0.17 parts by mass of thioglycolic acid are added dropwise at a rate of 4 drops / s, and after the addition is completed, the reaction is continued by keeping the temperature for 4 hours, and finally the solvent and the monomers not participating in the reaction are removed by rotary evaporation to obtain an acrylate prepolymer.

[0048] The preparation steps of the ammonium persulfate mixed solution are as follows: 7 parts by mass of ammonium persulfate are uniformly dispersed in 20 parts by mass of 1M hydrochloric acid solution to obtain the ammonium persulfate mixed solution.

[0049] The curing agent is obtained by combining m-phenylenediamine and m-phenylenediamine in a mass ratio of 1:4.

[0050] (Comparative Example 1)

[0051] The difference between Comparative Example 1 and Example 2 is that the acrylate composition is obtained by prepolymerizing butyl methacrylate, 2-isopropenylaniline, and allyl glycidyl ether and then combining them with acrylic acid; the remaining steps and components are the same as those in Example 2.

[0052] (Comparative Example 2)

[0053] The difference between Comparative Example 2 and Example 2 is that the acrylate composition is obtained by prepolymerizing butyl methacrylate, allyl glycidyl ether, and allyl cage-type polyhedral oligomeric silsesquioxane and then combining them with acrylic acid; the remaining steps and ingredients are the same as those in Example 2.

[0054] (Comparative Example 3)

[0055] The difference between Comparative Example 3 and Example 2 is that m-xylylenediamine is used as the curing agent; the remaining steps and components are the same as those of Example 2.

[0056] (Comparative Example 4)

[0057] The difference between Comparative Example 4 and Example 2 is that the preparation method of the water-based epoxy resin coating includes the following preparation steps:

[0058] Add 100 parts by mass of emulsified asphalt and 15-25 parts by mass of epoxy composite resin emulsion into a stirrer, pour 3-5 parts by mass of curing agent into 6-10 parts by mass of water to dilute and add to the stirrer and stir thoroughly for 20-40 minutes at room temperature to obtain a water-based epoxy resin coating; the remaining steps and ingredients are the same as those in Example 2.

[0059] Effect example:

[0060] Impact resistance: The impact resistance of the waterborne epoxy resin coating layers prepared in the test examples and comparative examples was tested with reference to GB / T1732.

[0061] Waterproofness: The contact angle of the waterborne epoxy resin coating layer prepared in the embodiment and the comparative example was measured by a JC2000DM contact angle measuring instrument produced by Shanghai Zhongchen Digital Technology Equipment Co., Ltd., and 2 μL of deionized water was used each time for the test.

[0062] Corrosion resistance: Referring to the water-based epoxy resin coating layer prepared in the test examples and comparative examples of GB / T1771, an "X" was scratched on the surface of the prepared coating until the bottom plate was exposed, and the coating was placed in a 35°C salt spray corrosion box. The corrosion condition of the scratch was observed after 240 hours, and the maximum corrosion width of the left and right scratches was measured.

[0063] Hardness: The hardness of the waterborne epoxy resin coating layer prepared in the embodiment and the comparative example was tested according to the national standard GB / T6739. A high-grade drawing pencil of the Zhonghua brand was used. The hardness was divided into 13 grades, namely, 6H, 5H, 4H, 3H, 2H, H, HB, B, 2B, 3B, 4B, 5B, and 6B. 6H was the hardest and 6B was the softest. Five scratches of about 1 cm were made on the coating at a speed of 1 cm / s. Starting from the maximum hardness, the hardness of the pencil was determined until there was no damage to the paint film. The hardness of the pencil was the hardness of the paint film.

[0064] Adhesion performance: Adhesion performance test was carried out with reference to JGJ / T70, and the waterborne epoxy resin coating prepared in the embodiment and the comparative example was applied to two cement mortar specimens. After bonding, the specimens were cured at 45°C for 24 hours. A tensile test was carried out on an electronic universal testing machine, and the maximum tensile force F was recorded. Each group of tests was tested in parallel 5 times to obtain the average value. The bonding strength (f) was calculated according to the following formula: f=F / A; wherein: F is the maximum tensile force obtained by the test, N; A is the bonding area.

[0065] Table 1 below shows the performance test results of the waterborne epoxy resin coatings prepared in the examples and comparative examples:

[0066] Table 1

[0067]

[0068] It can be seen from Table 1 above that the water-based epoxy resin coatings prepared in Examples 1 to 3 have strong waterproofness, corrosion resistance, impact resistance, adhesion and good hardness.

[0069] Comparative Example 1 is compared with Example 2. In the acrylate composition of Comparative Example 1, no allyl cage-type polyhedral oligomeric silsesquioxane is added, and the water-based epoxy resin coating obtained has weaker waterproofness, corrosion resistance, and impact resistance, and has lower hardness.

[0070] Comparative Example 2 Compared with Example 2, the acrylic ester composition of Comparative Example 2 does not add 2-isopropenylaniline, and the corrosion resistance and impact resistance of the obtained water-based epoxy resin coating are weak, and the hardness is low.

[0071] Comparative Example 3 is compared with Example 2. In Comparative Example 3, the curing agent does not use m-phenylenediamine, and the corrosion resistance and impact resistance of the obtained water-based epoxy resin coating are weak, and the hardness is low.

[0072] Comparative Example 4 Compared with Example 2, in the preparation method of the water-based epoxy resin coating of Comparative Example 4, no initiator ammonium persulfate mixed solution was added for reaction, polyaniline could not be formed, and the corrosion resistance and impact resistance of the obtained coating were weak, and the hardness was low.

[0073] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A water-based epoxy resin coating, characterized in that: The raw material components include, by weight: 15 to 25 parts by weight of epoxy composite resin emulsion, 100 parts by weight of emulsified asphalt, 3 to 5 parts by weight of curing agent, and 6 to 10 parts by weight of water.

2. The waterborne epoxy resin coating according to claim 1, characterized in that: The epoxy composite resin emulsion is obtained by composite reaction of 30-60 parts by weight of epoxy resin, 2-3 parts by weight of emulsifier, 6-9 parts by weight of acrylate composition and 1.4-1.6 parts by weight of auxiliary stabilizer.

3. The water-based epoxy resin coating according to claim 2, characterized in that: The acrylic ester composition is obtained by prepolymerizing 15-16 parts by weight of butyl methacrylate, 10-12 parts by weight of 2-isopropenylaniline, 5-7 parts by weight of allyl glycidyl ether, 1-1.2 parts by weight of allyl cage-type polyhedral oligomeric silsesquioxane and then combining them with 1-3 parts by weight of acrylic acid.

4. The water-based epoxy resin coating according to claim 1, characterized in that: The curing agent is obtained by combining meta-phenylenediamine and meta-phenylenediamine.

5. A method for preparing a water-based epoxy resin coating, characterized in that: The method comprises the following preparation steps: Add 100 parts by mass of emulsified asphalt and 15-25 parts by mass of epoxy composite resin emulsion into a stirrer, pour 3-5 parts by mass of curing agent into 6-10 parts by mass of water to dilute and add to the stirrer, stir thoroughly for 20-40 minutes at room temperature, then cool to 0-4°C, add ammonium persulfate mixed solution dropwise at 2-4 drops / s, continue stirring and reacting for 1-6 hours to obtain a water-based epoxy resin coating.

6. The method for preparing a waterborne epoxy resin coating according to claim 5, characterized in that: The preparation steps of the epoxy composite resin emulsion are as follows: 30 to 60 parts by weight of epoxy resin, 1 to 3 parts by weight of acrylic acid, acrylate prepolymer, and 1.4 to 1.6 parts by weight of hexadecane are stirred at 300 to 500 rpm for 10 to 20 minutes at room temperature, then an oxidative initiator ammonium persulfate and di-tert-butyl peroxide are added, and stirring is continued for 8 to 12 minutes, then an aqueous solution of an emulsifier is added, and stirring is continued at 400 to 600 rpm for 25 to 35 minutes, and then stirring is continued at 100 The mixture was sheared at 0-2000 rpm for 14-16 min, and homogenized at 80 MPa for 2-4 times using a high-pressure homogenizer to obtain a pre-emulsion; 25% of the pre-emulsion and 25% of the reducing initiator were mixed, the temperature was raised to 58-62°C, and the remaining 75% of the pre-emulsion and 75% of the reducing initiator were added separately using a peristaltic pump, the addition was completed within 55-65 min, and then, under nitrogen protection, polymerization was carried out at 58-62°C for 4-6 hours to obtain an epoxy composite resin emulsion.

7. The method for preparing a waterborne epoxy resin coating according to claim 6, characterized in that: The preparation steps of the acrylate prepolymer are as follows: toluene and butyl acetate are mixed in a mass ratio of 1:1 to obtain a mixed solvent; 10 parts by mass of the mixed solvent are taken, the temperature is raised to 44-46° C., and then 15-16 parts by mass of butyl methacrylate, 10-12 parts by mass of 2-isopropenylaniline, 5-7 parts by mass of allyl glycidyl ether, 0.15-0.17 parts by mass of azoisobutyronitrile, and 1-1.2 parts by mass of allyl cage-type polyhedral oligomeric silsesquioxane are added to obtain a solution A; 1 / 3 of the solution A is mixed with 24-26 parts by mass of the mixed solvent, the temperature is raised to 80° C., and after constant temperature stirring for 20 minutes, the remaining 2 / 3 of the solution A and 0.15-0.17 parts by mass of thioglycolic acid are added dropwise at a rate of 2-4 drops / s, and after the addition is completed, the reaction is continued by heat preservation for 4 hours, and finally the solvent and monomers not participating in the reaction are removed by rotary evaporation to obtain an acrylate prepolymer.

8. The method for preparing a waterborne epoxy resin coating according to claim 5, characterized in that: The preparation steps of the ammonium persulfate mixed solution are as follows: 6 to 7 parts by mass of ammonium persulfate are uniformly dispersed in 20 parts by mass of 1M hydrochloric acid solution to obtain the ammonium persulfate mixed solution.

9. The method for preparing a waterborne epoxy resin coating according to claim 5, characterized in that: The curing agent is obtained by combining meta-phenylenediamine and meta-phenylenediamine in a mass ratio of 1:2-4.

10. A method for applying a waterborne epoxy resin coating in bridge protection, characterized in that: The waterborne epoxy resin coating according to any one of claims 1 to 4 is mixed into cement mortar in an amount of 0.1 to 0.2 times the mass of cement mortar, and then filled in the damaged part of the bridge deck that needs to be repaired.

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