An epoxy coating, its preparation method and use

Abstract

The application relates to an epoxy coating material and a preparation method and application thereof. Raw materials of the coating material are composed of components A and B, wherein the component A comprises, in percentage of mass of the coating material, 15-20% of dimer acid modified bisphenol A type epoxy resin, 5-10% of polyurethane modified epoxy resin, 5-25% of pigment, 18-28% of filler, 10-15% of active diluent, 1-2% of dispersant, 0.5-2% of defoaming agent, 0.5-2% of leveling agent and 1-3% of rheological auxiliary agent; the component B comprises, in percentage of mass of the coating material, 5-10% of ketimine and 2-8% of polyether amine. The coating material has high elasticity, excellent corrosion resistance, complete solvent-free and good wet base construction adaptability, and has wide application prospects in the fields of buildings, bridges, ocean engineering and the like.

Description

Technical Field

[0001] This invention relates to an epoxy coating, its preparation method, and its application, and more particularly to a reactive elastomer-modified moisture-curing solvent-free epoxy coating and its preparation method, belonging to the field of polymer materials technology. Background Technology

[0002] In modern buildings and industrial facilities, surface protection of steel and concrete structures is crucial for ensuring their long-term durability. Affected by factors such as temperature stress, dynamic loads, and uneven settlement, the substrate often experiences dynamic propagation of microcracks, placing higher demands on the adaptability of protective coatings. While traditional epoxy coatings offer excellent corrosion protection, their inherent brittleness makes them unable to withstand substrate deformation, often leading to failure as the substrate cracks, thus compromising the protective system. Furthermore, these materials typically require application to clean, dry surfaces, demanding stringent substrate preparation standards, and their formulations often contain organic solvents, releasing large amounts of volatile organic compounds (VOCs) during application, posing a significant burden on the environment and human health.

[0003] While several protective materials with a degree of flexibility have entered the market, they still have significant shortcomings in terms of technical performance: some materials exhibit good flexibility but weak resistance to chemical media and barrier corrosion protection, making it difficult to meet the long-term protection requirements of harsh corrosive environments; others are limited by curing conditions, requiring application in low-humidity environments, making them unsuitable for high-humidity climates, rainy seasons, or damp conditions such as underground or underwater environments, severely restricting their application timeliness and geographical scope. Epoxy coatings that can be directly applied to damp substrates have become a pressing technical challenge in this field. Furthermore, many existing high-elasticity systems still employ solvent-based technologies, which contradicts the current green and low-carbon environmental protection policy.

[0004] Therefore, the industry urgently needs to develop a new type of coating material that simultaneously achieves high elasticity, excellent corrosion resistance, complete solvent-free properties, and good adaptability to wet substrates, thereby systematically resolving the contradictions and limitations of existing technologies. The successful development of such products will have significant technical and economic value. Summary of the Invention

[0005] The following is an overview of the subject matter described in detail herein. This overview is not intended to limit the scope of the claims.

[0006] To address the shortcomings of existing epoxy coating technologies, this invention aims to overcome the following key technical bottlenecks: 1. Solve the problem of coating cracking due to substrate deformation; 2. Overcome the stringent requirements of epoxy coatings on the humidity of the construction environment: Develop new coatings that can be directly cured on damp substrates or even underwater, eliminating the dependence on the dryness of the substrate and broadening their application in humid climates, underground engineering, water conservancy facilities and other fields; 3. Eliminate the use of organic solvents: Construct a completely solvent-free system formula to achieve zero VOC emissions, meet green environmental protection standards, and protect the health of construction workers and the safety of the ecological environment; 4. Reduced reliance on surface treatment level: Excellent adhesion and long-lasting corrosion protection can still be achieved even on substrate surfaces that are not sandblasted or can only meet low-level rust removal standards, reducing construction difficulty and cost; 5. Improve the curing adaptability of coatings under low temperature conditions, ensuring that the product can still react normally and complete curing in low temperature environments, thus expanding its applicability in cold regions or winter construction.

[0007] To address the shortcomings and deficiencies of existing technologies, this invention, based on innovative molecular structure design and curing mechanism, employs dimer acid-modified bisphenol A epoxy resin as the main resin. The flexible long-chain structure in its molecular chain endows the coating film with extremely high elastic deformation capability. Simultaneously, polyurethane-modified epoxy resin is introduced to further enhance the toughness and adhesion of the coating film. Regarding the curing system, an innovative composite curing technology of ketimine and polyetheramine is adopted: the ketimine curing agent decomposes upon exposure to moisture to generate active amines, achieving moisture curing; the polyetheramine curing agent provides a flexible cross-linking network, ensuring the high elasticity of the coating film.

[0008] The objective of this application can be achieved through the following technical solutions: The first aspect of this application provides an epoxy coating, characterized in that the raw materials of the coating are composed of component A and component B, wherein: Component A, by weight percentage of the coating, comprises: 15%-20% dimer acid modified bisphenol A type epoxy resin, 5%-10% polyurethane modified epoxy resin, 5%-25% pigment, 18%-28% filler, 10%-15% reactive diluent, 1%-2% dispersant, 0.5%-2% defoamer, 0.5%-2% leveling agent, and 1%-3% rheology modifier; Component B, by mass percentage of the coating, comprises: 5%-10% ketimine and 2%-8% polyetheramine.

[0009] In one exemplary embodiment, the A component, by mass percentage of the coating, comprises 15%-20% dimer acid modified bisphenol A type epoxy resin, 5%-10% polyurethane modified epoxy resin, 5%-25% pigment, 18%-28% filler, 10%-15% reactive diluent, 1%-2% dispersant, 0.5%-2% defoamer, 0.5%-2% leveling agent, and 1%-3% rheology modifier.

[0010] In one exemplary embodiment, component B, by weight percentage of the coating, consists of 5%-10% ketimine and 2%-8% polyetheramine.

[0011] In one exemplary embodiment, the dimer acid modified bisphenol A type epoxy resin is YD171, jER® 871, EPD-171E-X or YD172.

[0012] In one exemplary embodiment, the polyurethane-modified epoxy resin is UME305, UME330, PY 340, or NPER-133L.

[0013] In this application, C36 dicarboxylic acid (with a very long and flexible molecular chain) is introduced into the epoxy resin backbone in dimer acid-modified bisphenol A type epoxy resin, which is equivalent to adding flexible segments to a rigid epoxy network. In polyurethane-modified epoxy resin, flexible polyurethane segments are dispersed in a rigid epoxy resin crosslinking network. When subjected to external impact or stress, these flexible segments can absorb and disperse energy through deformation, effectively preventing crack propagation.

[0014] In one exemplary embodiment, the pigment includes one or more of titanium dioxide, carbon black, and phthalocyanine blue. The pigment provides hiding power and color, while also possessing a certain degree of corrosion resistance.

[0015] In one exemplary embodiment, the filler is any one or more of talc, barium sulfate, and feldspar powder, which adjusts the physical properties of the coating and reduces costs.

[0016] In one exemplary embodiment, the reactive diluent is a monofunctional epoxy reactive diluent or a glycidyl ether (AGE), optionally Ultra LITE 513 or SM-90P, which reduces the viscosity of the system without introducing VOCs.

[0017] In one exemplary embodiment, the dispersant is a modified polyurethane polymer, or a mixture of high molecular weight unsaturated carboxylic acid and highly compatible organic modified polysiloxane, optionally Efcona AFCONA PF502, Efcona AFCONA PF161, BYK-190, or BYK-163. The dispersant ensures uniform dispersion of the pigment filler.

[0018] In one exemplary embodiment, the defoamer is a non-silicone defoamer or a silicone defoamer, optionally BYK-052N, BYK-066N, Defom 6800, or TEGO902W. The defoamer prevents the formation of bubbles during construction.

[0019] In one exemplary embodiment, the leveling agent is Disparlon LHP-96, BYK-333, Efcona AFCONA PL241, or BYK-320. The leveling agent improves the leveling properties of the coating surface.

[0020] In one exemplary embodiment, the rheology modifier is a polyamide wax or organobentonite, optionally polyamide wax 6900-20X, polyamide wax A630-20X, organobentonite SK-08, or organobentonite BENTONE SD. The rheology modifier adjusts the application viscosity and prevents sagging.

[0021] In one exemplary embodiment, the ketimine is a ketimine-modified phenolic amine, optionally GX-5618, GX-5616, or DA324.

[0022] In one exemplary embodiment, the polyetheramine is a bifunctional terminal primary amine polyetheramine, optionally WANAMINE 8100, Huntsman D-230, or BASF EC-301.

[0023] The curing agent uses a composite system of ketimide curing agent and polyetheramine curing agent to achieve a balance between moisture curing and high elasticity.

[0024] The formulation of this application mainly utilizes the active amine released by the hydrolysis of ketimine in moisture. The active amine has excellent low-temperature curing properties and works synergistically with the directly added polyether amine to achieve rapid and thorough curing of the epoxy coating at low temperatures.

[0025] The second aspect of this application provides a method for preparing the above-mentioned epoxy coating, comprising the following steps: i) Preparation of component A: (1) Premixing stage: According to the raw material ratio, add dimer acid modified bisphenol A type epoxy resin and polyurethane modified epoxy resin into the mixing tank, and add reactive diluent and dispersant in sequence under stirring to make them fully mixed; (2) Pigment dispersion stage: According to the raw material ratio, slowly add pigment and defoamer, and stir until uniform; (3) Filler addition stage: Add various fillers in batches under stirring, and ensure that each filler is fully wetted before adding the next one; (4) Grinding stage: Transfer the mixture to a grinding equipment and grind it to a fineness of ≤30μm; (5) Paint mixing stage: Return the qualified slurry to the mixing tank, and add leveling agent and rheology modifier in sequence while stirring; (6) Filtration and packaging: After filtration through a sieve, the product is packaged to obtain component A; ii) Preparation of component B: According to the raw material ratio, ketimine and polyetheramine are mixed evenly in a sealed container to prevent the absorption of moisture from the air, and then packaged to obtain component B; and iii) Mix component A and component B and stir until homogeneous to obtain the epoxy coating.

[0026] In one exemplary embodiment, the method includes the following steps: i) Preparation of component A: (1) Premixing stage: According to the raw material ratio, the dimer acid modified bisphenol A type epoxy resin and the polyurethane modified epoxy resin are added to the mixing tank, and the reactive diluent and the dispersant are added in sequence at a speed of 300-500 rpm. Stir for 10-15 minutes to make them fully mixed. (2) Pigment dispersion stage: Increase the rotation speed to 800 rpm, slowly add the pigment and the defoamer, and stir for 20-30 minutes until uniform; (3) Filler addition stage: Maintain stirring speed and add various fillers in batches, ensuring that each filler is fully wetted before adding the next one; (4) Grinding stage: Transfer the mixture to a grinding equipment and grind it to a fineness of ≤30μm; (5) Paint mixing stage: Return the qualified slurry to the mixing tank, add the leveling agent and the rheology modifier in sequence at a speed of 400-600 rpm, and stir for 15-20 minutes; (6) Filtration and packaging: After filtration through a 200-mesh sieve, the product is packaged to obtain component A; ii) Preparation of component B: According to the raw material ratio, ketimine and polyetheramine are mixed evenly in a sealed container to prevent the absorption of moisture from the air, and then packaged to obtain component B; and iii) Mix component A and component B and stir until homogeneous to obtain the epoxy coating.

[0027] A third aspect of this application provides the application of the above-described epoxy coating or epoxy coating prepared by the above method on a damp substrate. Optionally, the substrate includes concrete, steel, or aluminum alloy.

[0028] The fourth aspect of this application provides a coating formed by the above-described epoxy coating or an epoxy coating prepared by the above method, wherein the coating is formed by applying the epoxy coating onto a substrate and curing it.

[0029] In some exemplary embodiments, the substrate includes concrete, steel, or aluminum alloy.

[0030] The epoxy coating of this application can be applied using high-pressure airless spraying, brushing, or roller coating. The ambient temperature during application should not be lower than -5°C, and the substrate surface temperature should be at least 3°C ​​above the dew point temperature. It can be applied directly to damp but dry concrete and steel structures. A dry film thickness of 200-500 μm is recommended. Curing time depends on ambient temperature and humidity; typically, surface drying time is 2-4 hours, actual drying time is approximately 24 hours, and complete curing takes about 7 days.

[0031] Compared with the prior art, this application has the following beneficial technical effects: Environmental advantages: Completely solvent-free design, zero VOC content, no pollution to the environment, and safe construction; Construction advantages: Breakthrough application to damp substrates, greatly simplifying surface preparation procedures and saving time and costs; Performance advantages: The coating film has both excellent elasticity, such as elongation at break >230% and excellent anti-corrosion performance, such as salt spray resistance >1500 hours, effectively adapting to the dynamic deformation of the substrate and avoiding protection failure due to crack expansion; Wide applicability: It can be applied and cured at low temperatures and is suitable for a variety of substrates, including concrete, steel, aluminum alloys, etc. Good economic benefits: a single application can achieve the protective effect of traditional multi-layer coating systems, with a long service life and low maintenance costs.

[0032] Specifically, the comparison with traditional coatings is as follows: Compared with the prior art document CN109456673A, this application demonstrates comprehensive advantages in key performance indicators. The coating of this application not only possesses a high elongation at break exceeding 230%, but also boasts an excellent tensile strength of 12-15 MPa, approximately twice that of CN109456673A (6-8 MPa), meaning the coating is more durable, wear-resistant, and resistant to damage. Furthermore, the adhesion of this application to concrete substrates (≥8 MPa) far surpasses the data for CN109456673A on dry substrates (2.5-5.0 MPa), and provides excellent anti-corrosion performance with salt spray resistance exceeding 1500 hours—a key indicator not mentioned in the prior art. In addition, the solvent-free nature of this application's coating and its low-temperature application at -5°C are also superior to existing technologies.

[0033] The elasticity of the coating in this application mainly comes from the flexible chain segment design of the resin itself and the flexible cross-linking of polyetheramine, which is an "internal toughening" technology. In contrast, CN109456673A relies more on the added "polyurethane toughening agent" to achieve elasticity, which is an "external toughening" method. The two are completely different in their technical paths to achieve high elasticity.

[0034] Other features and advantages of this application will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the application. Other advantages of this application can be realized and obtained by means of the embodiments described in the description and the accompanying drawings. Attached Figure Description

[0035] The accompanying drawings are used to provide an understanding of the technical solutions of this application and constitute a part of the specification. They are used together with the embodiments of this application to explain the technical solutions of this application and do not constitute a limitation on the technical solutions of this application.

[0036] Figure 1 The graph shows the tensile strength comparison curves for Examples 1-5, where the legend in the upper right corner, 2025091901-1, corresponds to Example 1, 2025091901-2 to Example 2, 2025091901-3 to Example 3, 2025091901-4 to Example 4, and 2025091901-5 to Example 5. Figure 2 The image shows the curing curves of the coating of Example 1 of this application under different humidity levels; and Figure 3 This is a comparison of the coating effect of the coating of Example 1 of this application and the traditional epoxy coating on a cracked substrate sample (the sample of Example 1 is on the right). Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in detail below. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be arbitrarily combined with each other.

[0038] The present invention will be further described in detail below with reference to the accompanying drawings and specific examples, but these examples should not be construed as limiting the present invention.

[0039] The following five typical embodiments further illustrate the specific implementation of the present invention, with each component expressed as a percentage by mass: Table 1: Formulation Table for Examples 1-5 (percentage by mass) The raw materials used in Examples 1 to 5 and the companies from which they were purchased are as follows: The dimer acid-modified bisphenol A epoxy resin was YD171, purchased from Guodu Chemical. The polyurethane-modified epoxy resins were UME305 and UME330, purchased from Guodu Chemical. The dispersant was AFCONA PF161, purchased from Evcona; The titanium dioxide was R996, purchased from Lomon. The reactive diluent was Ultra LITE 513, purchased from Cardlä, or AGE, purchased from Miki Chemical. The leveling agent was LHP-96, purchased from DISPARON; The defoamer was BYK-052N, purchased from BYK Chemical. Talc powder (800 mesh) is ZJ101, purchased from Qunxin; Barium sulfate (1250 mesh) was 44HB and purchased from Juguang. Feldspar powder (600 mesh) is GC-800, purchased from Greenpeace. The rheology modifier was polyamide wax 6900-20X, purchased from DISPARON; Organic bentonite SK-08, purchased from Jiangsu Mining Bureau; Ketoimine was GX-5618 or GX-5616, purchased from Cardlä; The polyetheramine used was WANAMINE 8100, purchased from Huntsman.

[0040] In Examples 1 to 5, the preparation methods of the epoxy coatings are as follows: i) Preparation of component A: (1) Premixing stage: According to the raw material ratio, add dimer acid modified bisphenol A type epoxy resin YD171, polyurethane modified epoxy resin UME305 and UME330 into the mixing tank, add reactive diluent and dispersant in sequence at a speed of 300-500 rpm, and stir for 10-15 minutes to make it fully mixed. (2) Pigment dispersion stage: Increase the speed to 800 rpm, slowly add titanium dioxide and defoamer, and stir for 20-30 minutes until uniform; (3) Filler addition stage: Maintain stirring speed and add talc, barium sulfate and feldspar powder in batches, ensuring that each filler is fully wetted before adding the next one; (4) Grinding stage: Transfer the mixture to a grinding equipment and grind it to a fineness of ≤30μm; (5) Paint mixing stage: Return the qualified slurry to the mixing tank, add leveling agent LHP-96, polyamide wax 6900-20X and organic bentonite SK-08 in sequence at a speed of 400-600 rpm, and stir for 15-20 minutes; (6) Filtration and packaging: After filtration through a 200-mesh sieve, the product is packaged to obtain component A; ii) Preparation of component B: According to the raw material ratio, ketimines GX-5618 and GX-5616 are mixed evenly with polyetheramine WANAMINE 8100 in a sealed container to prevent the absorption of moisture from the air, and then packaged to obtain component B; and iii) Mix component A and component B and stir until homogeneous to obtain epoxy coating.

[0041] Coating samples were prepared according to the above formulation, and performance tests were conducted according to national standards. All examples exhibited the following excellent properties: Table 2: Performance Indicators of Examples 1-5 The examples show that Examples 1 to 5 can form a complete, continuous, and defect-free coating on damp concrete surfaces (moisture content > 8%) and manually rust-removed (St2 grade) steel surfaces, effectively covering microcracks smaller than 0.3 mm.

[0042] 1. Curing speed: The curing speed increases significantly with the increase of WANAMINE 8100 content in the formulation. The higher the WANAMINE content, the shorter the surface drying time and the complete drying time.

[0043] 2. Mechanical properties: The elongation at break increases significantly with the increase of the flexible segment polyetheramine content. Correspondingly, its tensile strength decreases slightly, but still remains within the range of excellent high performance.

[0044] 3. Adhesion: All formulations exhibit excellent adhesion, fully meeting high standards. Slight differences arise from minor variations in filler type and content, as well as differences in the internal stress of the cured coating.

[0045] 4. Corrosion resistance & water resistance: The pigment and filler systems of the five formulations (high content of titanium dioxide, barium sulfate, etc.) provide excellent physical shielding, and the epoxy-amine system has a high crosslinking density after curing. Therefore, all examples show excellent and very similar salt spray and water resistance.

[0046] 5. Environmental friendliness: Based on a solvent-free system with 100% active ingredients, the VOC content of all formulations was undetectable, demonstrating excellent environmental performance.

[0047] Example 1 has the best overall performance.

[0048] The above formulation design of this application can not only meet the requirements of heavy-duty anti-corrosion fields with high mechanical performance, but also has excellent curing speed and construction adaptability, making it suitable for most conventional application scenarios.

[0049] Based on Example 1, the degree of curing under different humidity conditions was compared. Table 3 systematically analyzes the changes in key performance indicators of the formulation in Example 1 under different relative humidity (RH).

[0050] Table 3: Curing data of the coating in Example 1 under different humidity conditions The present invention also provides comparative examples 1 to 4, the formulations of which are shown in Table 4.

[0051] Table 4: Formulation Tables for Comparative Examples 1-4 (mass percentage %) The raw materials and preparation methods used in Comparative Examples 1 to 4 were the same as those in Examples 1 to 5. The performance of the coatings obtained in Comparative Examples 1 to 4 was tested, and the test results are shown in Table 5.

[0052] Table 5: Performance Indicators of Example 1 and Comparative Examples 1-4 A comparison of the coatings from Comparative Examples 1 to 4 with those from Example 1 reveals that the simplification of the epoxy resin system leads to a comprehensive decrease in the flexibility, adhesion, smoke resistance, and water resistance of the coating film. The disruptive modification of the curing agent system in Comparative Example 4 severely hinders the curing process, resulting in a drastically prolonged drying time and a catastrophic decline in the mechanical and protective properties of the coating film. This demonstrates that polyetheramine is indispensable in this formulation for forming a complete, high-performance coating network.

[0053] In summary, this invention successfully developed a moisture-curing, highly elastic, solvent-free epoxy coating, overcoming the industry challenges of traditional epoxy materials' excessive rigidity but insufficient toughness, and their strict reliance on dry substrates and high-grade rust removal. Through innovative resin system design and curing mechanism, utilizing a moisture-triggered curing mechanism, the coating film achieves an elongation at break exceeding 230%, while simultaneously forming a dense and tough anti-corrosion barrier on low-surface-treatment substrates. This perfectly resolves the contradiction between high elasticity and strong corrosion resistance, and between moisture application and environmental performance, demonstrating revolutionary application advantages. This product not only boasts excellent performance but also offers simple application, wide applicability, and significant economic and social benefits, with broad application prospects in fields such as construction, bridges, and marine engineering.

[0054] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. An epoxy coating, characterized in that, The raw materials of the coating consist of component A and component B, wherein: Component A, by weight percentage of the coating, comprises: 15%-20% dimer acid modified bisphenol A type epoxy resin, 5%-10% polyurethane modified epoxy resin, 5%-25% pigment, 18%-28% filler, 10%-15% reactive diluent, 1%-2% dispersant, 0.5%-2% defoamer, 0.5%-2% leveling agent, and 1%-3% rheology modifier; Component B, by mass percentage of the coating, comprises: 5%-10% ketimine and 2%-8% polyetheramine.

2. The epoxy coating according to claim 1, characterized in that, The dimer acid-modified bisphenol A type epoxy resin is YD171, jER® 871, EPD-171E-X or YD172; and / or The polyurethane-modified epoxy resin is UME305, UME330, PY 340 or NPER-133L.

3. The epoxy coating according to claim 1, characterized in that, The pigment includes any one or more of titanium dioxide, carbon black, and phthalocyanine blue; and / or The filler is any one or more of talc powder, barium sulfate, and feldspar powder; and / or The reactive diluent is a monofunctional epoxy reactive diluent or a glycidyl ether, optionally Ultra LITE513 or SM-90P; and / or The dispersant is a modified polyurethane polymer, or a mixture of high molecular weight unsaturated carboxylic acid and highly compatible organic modified polysiloxane, optionally Efcona AFCONA PF502, Efcona AFCONA PF161, BYK-190 or BYK-163; and / or The defoamer is a non-silicone defoamer or a silicone defoamer, optionally BYK-052N, BYK-066N, Defom6800, or TEGO902W; and / or The leveling agent is Disparlon LHP-96, BYK-333, AFCONA PL241, or BYK-320; and / or The rheology modifier is polyamide wax or organobentonite, optionally polyamide wax 6900-20X, polyamide wax A630-20X, organobentonite SK-08 or organobentonite BENTONE SD.

4. The epoxy coating according to any one of claims 1-3, characterized in that, The ketimine is a ketimine-modified phenolic amine, optionally GX-5618, GX-5616, or DA324; and / or The polyetheramine is a bifunctional terminal primary amine polyetheramine, optionally WANAMINE 8100, Huntsman D-230 or BASF EC-301.

5. The method for preparing the epoxy coating according to any one of claims 1-4, characterized in that, Includes the following steps: i) Preparation of component A: (1) Premixing stage: According to the raw material ratio, add dimer acid modified bisphenol A type epoxy resin and polyurethane modified epoxy resin into the mixing tank, and add reactive diluent and dispersant in sequence under stirring to make them fully mixed; (2) Pigment dispersion stage: According to the raw material ratio, slowly add pigment and defoamer, and stir until uniform; (3) Filler addition stage: Add various fillers in batches under stirring, ensuring that each filler is fully wetted before adding the next one; (4) Grinding stage: Transfer the mixture to a grinding equipment and grind it to a fineness of ≤30μm; (5) Paint mixing stage: Return the qualified slurry to the mixing tank, and add leveling agent and rheology modifier in sequence while stirring; (6) Filtration and packaging: After filtration through a sieve, the product is packaged to obtain component A; ii) Preparation of component B: According to the raw material ratio, ketimine and polyetheramine are mixed evenly in a sealed container to prevent the absorption of moisture from the air, and then packaged to obtain component B; and iii) Mix component A and component B and stir until homogeneous to obtain the epoxy coating.

6. The method according to claim 5, characterized in that, The method includes the following steps: i) Preparation of component A: (1) Premixing stage: According to the raw material ratio, the dimer acid modified bisphenol A type epoxy resin and the polyurethane modified epoxy resin are added to the mixing tank, and the reactive diluent and the dispersant are added in sequence at a speed of 300-500 rpm. Stir for 10-15 minutes to make them fully mixed. (2) Pigment dispersion stage: Increase the rotation speed to 800 rpm, slowly add the pigment and the defoamer, and stir for 20-30 minutes until uniform; (3) Filler addition stage: Maintain stirring speed and add various fillers in batches, ensuring that each filler is fully wetted before adding the next one; (4) Grinding stage: Transfer the mixture to a grinding equipment and grind it to a fineness of ≤30μm; (5) Paint mixing stage: Return the qualified slurry to the mixing tank, add the leveling agent and the rheology modifier in sequence at a speed of 400-600 rpm, and stir for 15-20 minutes; (6) Filtration and packaging: After filtration through a 200-mesh sieve, the product is packaged to obtain component A; ii) Preparation of component B: According to the raw material ratio, ketimine and polyetheramine are mixed evenly in a sealed container to prevent the absorption of moisture from the air, and then packaged to obtain component B; and iii) Mix component A and component B and stir until homogeneous to obtain the epoxy coating.

7. The application of the epoxy coating according to any one of claims 1-4 or the epoxy coating prepared by the method according to claim 5 or 6 on a damp substrate, wherein the substrate optionally includes concrete, steel or aluminum alloy.

8. A coating formed by an epoxy coating according to any one of claims 1-4 or an epoxy coating prepared by the method according to claim 5 or 6, wherein the coating is formed by applying the epoxy coating to a substrate and curing it, and optionally, the substrate includes concrete, steel or aluminum alloy.

Images