Waterproof coating and preparation method thereof

Abstract

The invention relates to the technical field of waterproof coatings, in particular to a waterproof coating and a preparation method thereof.The waterproof coating comprises a composite layer structure formed after spraying, and the composite layer structure is composed of three functional layers including a high-permeability crystallization layer, an elastic waterproof layer and a self-cleaning hydrophobic layer; the three functional layers realize interface fusion through chemical bond crosslinking; according to the invention, the three functional layers realize interface fusion through chemical bond cross-linking, and the organic silicon resin permeates into the microcapsule gaps of the elastic layer to form a dual combination mechanism of physical winding and chemical cross-linking, so that the interlayer adhesive force is obviously improved, and the layering phenomenon is avoided. A gradient protection system is formed through chemical combination of the high-permeability crystallization layer and the base layer, the deformation adaptability of the elastic layer and the surface protection function of the hydrophobic layer, so that the coating has excellent waterproofness, high mechanical property and self-cleaning capacity. In addition, due to the introduction of the self-repairing microcapsules and photocatalytic TiO2, the coating is endowed with double functions of self-repairing and self-cleaning, the service life is prolonged, and the maintenance cost is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of waterproof coating, in particular to a waterproof coating and a preparation method thereof. BACKGROUND

[0002] In the field of construction, transportation and other engineering, coating as an important functional material undertakes the key role of protecting the base and prolonging the service life. Among them, waterproof coating plays a relatively important role in preventing water penetration and ensuring structural safety. With the development of building technology and the complexity of the use environment, the market demand for waterproof coating has changed from single waterproof function to durability, adaptability and multifunctionality.

[0003] The waterproof coating in the prior art generally has the problem of single function, and most coating products can only meet the basic waterproof requirement, and it is difficult to simultaneously realize performance guarantee in self-cleaning, mechanical property and other aspects. For example, the traditional waterproof coating is easy to adsorb pollutants on the surface after long-term exposure to the external environment, which not only affects the appearance, but also may accelerate the aging of the coating; in addition, its mechanical property is insufficient, and when the base slightly deforms, the coating is easy to crack and fall off, resulting in waterproof failure. Although some coatings containing elastic components have certain tensile properties, they lack self-repairing ability and are difficult to recover after damage, which requires manual maintenance and increases the use cost. SUMMARY

[0004] The purpose of the present application is to provide a waterproof coating, which is composed of three functional layers of high-permeability crystalline layer, elastic waterproof layer and self-cleaning hydrophobic layer.

[0005] To achieve the above-mentioned purpose, the present application provides the following technical scheme: A waterproof coating forms a composite layer structure after spraying, which is composed of three functional layers of high-permeability crystalline layer, elastic waterproof layer and self-cleaning hydrophobic layer, the thickness of the high-permeability crystalline layer is 0.1-0.3mm, the thickness of the elastic waterproof layer is 0.3-0.5mm, and the thickness of the self-cleaning hydrophobic layer is 0.05-0.15mm; the three functional layers are fused by chemical bond crosslinking; the high-permeability crystalline layer contains active silicate and nano-silica aerogel; the elastic waterproof layer takes acrylic acid-epoxy resin composite emulsion as the matrix and embeds self-repairing microcapsules; the self-cleaning hydrophobic layer is organic silicon resin loaded with photocatalytic nano-TiO2, and the chemical bond crosslinking is formed by the reaction of the organic silicon resin infiltrating into the gap between the microcapsules when the elastic layer is not cured and the acrylic acid-epoxy resin composite emulsion under the environment of 50-70℃ and humidity of 40-60%. Preferably, in the high-permeability crystalline layer, the content of active silicate is 30-40 parts by weight, and the content of nano-silica aerogel is 30-45 parts by weight.

[0006] Preferably, in the elastic waterproof layer, the weight ratio of acrylic emulsion to epoxy resin emulsion in the acrylic-epoxy resin composite emulsion is 1-3-5, and its content is 50-60 parts by weight, and the content of self-healing microcapsules accounts for 3-8% of the total weight of the elastic waterproof layer.

[0007] Preferably, the acrylic-epoxy resin composite emulsion has an average particle size of 0.1-0.5 μm, a solid content of 45-65%, a glass transition temperature of -20℃ to 10℃, and a viscosity of 500-2000 mPa·s at 25℃.

[0008] Preferably, the core of the self-healing microcapsule is composed of a self-healing prepolymer generated by reacting dicyclopentadiene and vinyl silicone oil in a molar ratio of 1-2:3 under a platinum catalyst of 0.3-0.7wt%; the wall material is a polyvinyl alcohol-sodium alginate composite membrane, wherein the weight ratio of polyvinyl alcohol to sodium alginate in the wall material is 2:2-3, and the microcapsule particle size is 40-120μm. Preferably, in the self-cleaning hydrophobic layer, the content of the organosilicon resin supporting photocatalytic nano-TiO2 is 10-15 parts by weight, the nano-TiO2 particle size is 10-30 nm, and the content accounts for 15-18% of the total weight of the self-cleaning hydrophobic layer.

[0009] Waterproof coating methods include the following steps: Step 1: Preparation of coatings for each functional layer: Prepare the coatings for each functional layer according to the weight proportions. Step Two: Layered Coating and Curing: Apply the coating in layers, spraying in the following order: high-penetration crystalline layer, elastic waterproof layer, and self-cleaning hydrophobic layer. The spraying pressure is 0.2-0.3 MPa. The high-penetration crystalline layer is heat-cured at 60-85℃ for 1.5-2 hours. When the coating hardness reaches Shore A 25-30, the elastic waterproof layer is applied. The elastic waterproof layer requires interface strengthening treatment. After interface strengthening treatment, the hydrophobic layer is sprayed. The initial curing temperature of the hydrophobic layer is 60-70℃, and the time is 1-1.5 hours. Control the amount of each layer sprayed to achieve the corresponding thickness. Step 3: Interface strengthening treatment: When the elastic layer is cured at a temperature of 70-75 degrees Celsius and the hardness reaches Shore A15-20, a hydrophobic layer is sprayed to allow the silicone resin to penetrate into the gaps between the microcapsules to form an interpenetrating network. Step 4: Secondary curing of the hydrophobic layer: After the hydrophobic layer is sprayed, it is cured for 1-1.5 hours at 98-105℃. Preferably, when preparing the high-penetration crystalline coating, the raw materials are dispersed in 100-150 parts by weight of deionized water and subjected to ultrasonic dispersion treatment for 30-40 minutes.

[0010] Preferably, when the elastic layer coating is prepared, the acrylic-epoxy resin composite emulsion and the self-healing microcapsules are continuously dispersed at a stirring speed of 350-450 rpm for 30-40 minutes, and 35-40 parts by weight of deionized water are added during the dispersion process to adjust the viscosity.

[0011] Preferably, when preparing the self-cleaning hydrophobic coating, the organosilicon resin loaded with photocatalytic nano-TiO2 is dissolved in 40-50 parts by weight of anhydrous ethanol, 1.2-1.8 parts by weight of silane coupling agent is added, and the mixture is stirred and mixed at 50-60°C for 1-2 hours. Then, nano-TiO2 is added and the mixture is further dispersed for 40-60 minutes.

[0012] Compared with the prior art, the beneficial effects of the present invention are: In this invention, the waterproof coating provides a combination of multiple protective functions and performance enhancement through the synergistic design of a three-layer functional structure and the optimization of specific components.

[0013] The high-permeability crystalline layer in this invention is composed of active silicate and nano-silica aerogel. The active silicate can penetrate deep into the pores of the substrate and undergo a chemical reaction to generate insoluble crystals that block capillary channels, forming a permanent waterproof barrier. The nano-silica aerogel has a high specific surface area and low thermal conductivity, which not only enhances the coating's permeability and crystallization ability but also improves the coating's anti-aging properties and thermal stability.

[0014] The elastic waterproof layer in this invention uses an acrylic-epoxy resin composite emulsion as the matrix, embedding self-healing microcapsules. The acrylic emulsion imparts high elasticity and elongation at break to the coating, while the epoxy resin enhances adhesion and strength. The composite of these two materials forms a network structure that combines flexibility and rigidity. When the coating is damaged, the core of the self-healing microcapsule ruptures, and dicyclopentadiene and vinyl silicone oil prepolymer undergo a cross-linking reaction under the action of a platinum catalyst, filling the cracks and achieving the self-healing function.

[0015] The self-cleaning hydrophobic layer in this invention is composed of an organosilicon resin loaded with photocatalytic nano-TiO2. The organosilicon resin undergoes chemical cross-linking with the uncured composite emulsion of the elastic layer, forming an interpenetrating network structure that enhances interlayer bonding. The nano-TiO2 exhibits a photocatalytic effect under ultraviolet light, decomposing surface contaminants. Simultaneously, the low surface energy of the organosilicon resin imparts a hydrophobic effect to the coating, reducing contaminant adhesion.

[0016] In this invention, the three functional layers achieve interfacial fusion through chemical cross-linking. Organosilicon resin penetrates the microcapsule gaps in the elastic layer, forming a dual bonding mechanism of physical entanglement and chemical cross-linking, significantly improving interlayer adhesion and preventing delamination. The chemical bonding between the high-penetration crystalline layer and the substrate, the deformation adaptability of the elastic layer, and the surface protection function of the hydrophobic layer form a gradient protection system, giving the coating excellent waterproofing, high mechanical properties, and self-cleaning ability. Furthermore, the introduction of self-healing microcapsules and photocatalytic TiO2 endows the coating with dual functions of self-healing and self-cleaning, extending its service life, reducing maintenance costs, and solving the problems of single function and insufficient mechanical properties in existing coatings. Attached Figure Description

[0017] Figure 1 This is a flowchart of a method for preparing a waterproof coating. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0019] This invention provides a waterproof coating that forms a composite layer structure after spraying. This composite layer consists of three functional layers: a high-permeability crystalline layer, an elastic waterproof layer, and a self-cleaning hydrophobic layer. The thicknesses of each layer are as follows: high-permeability crystalline layer 0.1-0.3 mm, elastic waterproof layer 0.3-0.5 mm, and self-cleaning hydrophobic layer 0.05-0.15 mm. The three functional layers achieve interfacial fusion through chemical bond cross-linking, wherein: The highly permeable crystalline layer comprises active silicates and nano-silica aerogel; The elastic waterproof layer uses an acrylic-epoxy resin composite emulsion as the matrix and embeds self-healing microcapsules; The self-cleaning hydrophobic layer is an organosilicon resin loaded with photocatalytic nano-TiO2.

[0020] Chemical crosslinking occurs when silicone resin penetrates into the gaps between microcapsules before the elastic layer is cured, and reacts with acrylic-epoxy resin composite emulsion at 50-70℃ and 40-60% humidity to form crosslinks.

[0021] The following are the specific preparation steps: Formulation of coatings for each functional layer High-penetration crystalline coating: Disperse 30-40 parts by weight of active silicate and 30-45 parts by weight of nano-silica aerogel in 100-150 parts by weight of deionized water and perform ultrasonic dispersion treatment for 30-40 minutes.

[0022] Elastic waterproof coating: An acrylic-epoxy resin composite emulsion (acrylic emulsion to epoxy resin emulsion weight ratio 1-3:5, content 50-60 parts by weight) and self-healing microcapsules accounting for 3-8% of the total weight of the elastic waterproof coating are continuously dispersed at a stirring speed of 350-450 rpm for 30-40 minutes. During the dispersion process, 35-40 parts by weight of deionized water are added to adjust the viscosity. The composite emulsion has an average particle size of 0.1-0.5 μm, a solid content of 45-65%, a glass transition temperature of -20℃ to 10℃, and a viscosity of 500-2000 mPa·s at 25℃. The self-healing microcapsule core is composed of a self-healing prepolymer generated by reacting dicyclopentadiene and vinyl silicone oil at a molar ratio of 1-2:3 under a platinum catalyst of 0.3-0.7 wt%. The wall material is a polyvinyl alcohol-sodium alginate composite film, with a polyvinyl alcohol to sodium alginate weight ratio of 2:2-3 and a microcapsule particle size of 40-120 μm.

[0023] Self-cleaning hydrophobic coating: Dissolve 10-15 parts by weight of organosilicon resin loaded with photocatalytic nano-TiO2 in 40-50 parts by weight of anhydrous ethanol, add 1.2-1.8 parts by weight of silane coupling agent, stir and mix at 50-60℃ for 1-2 hours, then add 15-18% of nano-TiO2 (particle size 10-30nm) of the total weight of the self-cleaning hydrophobic layer and continue to disperse for 40-60 minutes.

[0024] Layered coating and curing Apply the coating in the following order: high-penetration crystalline layer, elastic waterproof layer, and self-cleaning hydrophobic layer, with a spraying pressure of 0.2-0.3 MPa.

[0025] The high-penetration crystalline layer is heat-cured at 60-85℃ for 1.5-2 hours. When the coating hardness reaches Shore A25-30, the elastic waterproof layer is then applied.

[0026] The elastic layer is cured at 70-75℃. When the hardness reaches Shore A15-20, an interface strengthening treatment is performed, and then a hydrophobic layer is sprayed on.

[0027] The initial curing temperature of the hydrophobic layer is 60-70℃, and the time is 1-1.5 hours; the secondary curing is carried out at 98-105℃ for 1-1.5 hours.

[0028] The following are specific embodiments. Example

[0029] High-permeability crystalline layer: 35 parts by weight of active silicate, 38 parts by weight of nano-silica aerogel, 120 parts by weight of deionized water, ultrasonically dispersed for 35 minutes.

[0030] Elastic waterproof layer: acrylic emulsion to epoxy resin emulsion weight ratio 2:5, composite emulsion 55 parts by weight, self-healing microcapsules account for 5% of the total weight, stirring speed 400 rpm, dispersion for 35 minutes, and deionized water 38 parts by weight added.

[0031] Self-cleaning hydrophobic layer: 12 parts by weight of organosilicon resin loaded with photocatalytic nano-TiO2, 45 parts by weight of anhydrous ethanol, 1.5 parts by weight of silane coupling agent, and nano-TiO2 accounting for 16% of the total weight, prepared according to the steps.

[0032] Coating and curing: Spraying pressure 0.25MPa, high-penetration crystalline layer cured at 70℃ for 1.8 hours, elastic layer cured at 72℃ to Shore hardness A18 for interface strengthening, hydrophobic layer initially cured at 65℃ for 1.2 hours, then cured at 100℃ for 1.3 hours. Example

[0033] High-permeability crystalline layer: 30 parts by weight of active silicate, 45 parts by weight of nano-silica aerogel, 100 parts by weight of deionized water, ultrasonically dispersed for 30 minutes.

[0034] Elastic waterproof layer: Acrylic emulsion and epoxy resin emulsion in a weight ratio of 1:5, 60 parts by weight of composite emulsion, self-healing microcapsules accounting for 3% of the total weight, stirring speed of 350 rpm, dispersion for 40 minutes, and adding 35 parts by weight of deionized water.

[0035] Self-cleaning hydrophobic layer: 10 parts by weight of organosilicon resin loaded with photocatalytic nano-TiO2, 50 parts by weight of anhydrous ethanol, 1.2 parts by weight of silane coupling agent, and nano-TiO2 accounting for 18% of the total weight.

[0036] Coating and curing: Spraying pressure 0.2MPa, high-penetration crystalline layer cured at 60℃ for 2 hours, elastic layer cured at 70℃ to Shore hardness A15 for interface strengthening, hydrophobic layer initially cured at 60℃ for 1.5 hours, then cured at 98℃ for 1.5 hours. Example

[0037] High-permeability crystalline layer: 40 parts by weight of active silicate, 30 parts by weight of nano-silica aerogel, 150 parts by weight of deionized water, ultrasonically dispersed for 40 minutes.

[0038] Elastic waterproof layer: acrylic emulsion to epoxy resin emulsion weight ratio 3:5, composite emulsion 50 parts by weight, self-healing microcapsules account for 8% of the total weight, stirring speed 450 rpm, disperse for 30 minutes, add deionized water 40 parts by weight.

[0039] Self-cleaning hydrophobic layer: 15 parts by weight of organosilicon resin loaded with photocatalytic nano-TiO2, 40 parts by weight of anhydrous ethanol, 1.8 parts by weight of silane coupling agent, and nano-TiO2 accounting for 15% of the total weight.

[0040] Coating and curing: Spraying pressure 0.3MPa, high-penetration crystalline layer cured at 85℃ for 1.5 hours, elastic layer cured at 75℃ to Shore hardness A20 for interface strengthening, hydrophobic layer initially cured at 70℃ for 1 hour, then cured at 105℃ for 1 hour. Example

[0041] High-permeability crystalline layer: 32 parts by weight of active silicate, 42 parts by weight of nano-silica aerogel, 130 parts by weight of deionized water, ultrasonically dispersed for 38 minutes.

[0042] Elastic waterproof layer: acrylic emulsion to epoxy resin emulsion weight ratio 2.5:5, composite emulsion 58 parts by weight, self-healing microcapsules account for 6% of the total weight, stirring speed 420 rpm, dispersion for 32 minutes, and deionized water 37 parts by weight added.

[0043] Self-cleaning hydrophobic layer: 13 parts by weight of organosilicon resin loaded with photocatalytic nano-TiO2, 43 parts by weight of anhydrous ethanol, 1.6 parts by weight of silane coupling agent, and nano-TiO2 accounting for 17% of the total weight.

[0044] Coating and curing: Spraying pressure 0.26MPa, high-penetration crystalline layer cured at 75℃ for 1.7 hours, elastic layer cured at 73℃ to Shore hardness A17 for interface strengthening, hydrophobic layer initially cured at 68℃ for 1.1 hours, then cured at 102℃ for 1.2 hours. Example

[0045] High-permeability crystalline layer: 38 parts by weight of active silicate, 35 parts by weight of nano-silica aerogel, 140 parts by weight of deionized water, ultrasonically dispersed for 36 minutes.

[0046] Elastic waterproof layer: acrylic emulsion to epoxy resin emulsion weight ratio 1.5:5, composite emulsion 52 parts by weight, self-healing microcapsules account for 7% of the total weight, stirring speed 380 rpm, dispersion for 38 minutes, and deionized water 39 parts by weight added.

[0047] Self-cleaning hydrophobic layer: 14 parts by weight of organosilicon resin loaded with photocatalytic nano-TiO2, 42 parts by weight of anhydrous ethanol, 1.7 parts by weight of silane coupling agent, and nano-TiO2 accounting for 16.5% of the total weight.

[0048] Coating and curing: Spraying pressure 0.28MPa, high-penetration crystalline layer cured at 80℃ for 1.6 hours, elastic layer cured at 74℃ to Shore hardness A19 for interface strengthening, hydrophobic layer initially cured at 67℃ for 1.3 hours, then cured at 103℃ for 1.1 hours.

[0049] Comparative Example 1 The difference between this comparative example and Example 1 is that this comparative example lacks a high-penetration crystalline layer and directly sprays an elastic waterproof layer and a self-cleaning hydrophobic layer.

[0050] Comparative Example 2 The difference between this comparative example and Example 1 is that: no self-healing microcapsules were added to the elastic waterproof layer in this comparative example, the weight ratio of acrylic emulsion to epoxy resin emulsion was 2:5, and the composite emulsion was 55 parts by weight.

[0051] Comparative Example 3 The difference between this comparative example and Example 1 is that the self-cleaning hydrophobic layer in this comparative example is not loaded with nano-TiO2, but only uses organosilicon resin with a content of 12 parts by weight, anhydrous ethanol 45 parts by weight, and silane coupling agent 1.5 parts by weight.

[0052] test Experiment 1: Waterproof Performance Test Referencing GB / T16777-2008 "Test Methods for Waterproof Coatings for Buildings", the impermeability and elongation at break of the samples were tested.

[0053] Impermeability: Use a cross-shaped plate, apply pressure of 0.3 MPa, maintain for 30 minutes, and observe whether there is water leakage.

[0054] Elongation at break: Prepare specimens according to standard, tensile speed 500 mm / min, and test the elongation at break; All embodiments exhibited excellent waterproof performance, being impermeable to water and having high elongation at break, thanks to the synergistic effect of the three-layer structure: the high-permeability crystalline layer penetrates deep into the base layer, the elastic layer provides tensile properties, and the hydrophobic layer prevents water penetration.

[0055] Experiment 2: Elastic Recovery Rate Test Referring to GB / T23445-2009 "Polymer Cement Waterproof Coatings", the elastic recovery ability of the samples after tension was tested. The specimen was stretched to 100% of its original length, held for 10 minutes, and then released. The recovery rate was measured after 1 hour. The elastic recovery rates of the embodiments were all above 93%, which is excellent. This is because the acrylic-epoxy resin composite emulsion in the elastic waterproof layer works synergistically with the self-healing microcapsules to give the coating good elasticity and recovery ability.

[0056] Experiment 3: Self-cleaning performance test Referring to GB / T23261-2009 "Glass and Metal Railings for Buildings", simulated pollutants (a mixture of kaolin and water) were sprayed onto the sample surface. After drying, the sample was irradiated with an ultraviolet lamp (wavelength 365nm, power 100W) for 12 hours, and the pollutant removal rate was observed. The self-cleaning effect of the embodiment is significant, with a removal rate of over 90%. This is because the nano-TiO2 in the self-cleaning hydrophobic layer plays a photocatalytic role under ultraviolet light, decomposing pollutants. At the same time, the hydrophobic surface of the organosilicon resin reduces the adhesion of pollutants.

[0057] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0058] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A waterproof coating, characterized in that, After spraying, a composite layer structure is formed, consisting of three functional layers: a high-permeability crystalline layer, an elastic waterproof layer, and a self-cleaning hydrophobic layer. The thickness of the high-permeability crystalline layer is 0.1-0.3 mm, the thickness of the elastic waterproof layer is 0.3-0.5 mm, and the thickness of the self-cleaning hydrophobic layer is 0.05-0.15 mm. The three functional layers achieve interface fusion through chemical bond cross-linking. The high-permeability crystalline layer contains active silicates and nano-silica aerogel. The elastic waterproof layer uses an acrylic-epoxy resin composite emulsion as the matrix and embeds self-healing microcapsules. The self-cleaning hydrophobic layer is an organosilicon resin loaded with photocatalytic nano-TiO2.

2. The waterproof coating according to claim 1, characterized in that, The high-permeability crystalline layer contains 30-40 parts by weight of active silicate and 30-45 parts by weight of nano-silica aerogel.

3. The waterproof coating according to claim 1, characterized in that, In the elastic waterproof layer, the acrylic-epoxy resin composite emulsion has an acrylic emulsion to epoxy resin emulsion weight ratio of 1-3-5 and a content of 50-60 parts by weight, and the self-healing microcapsule content accounts for 3-8% of the total weight of the elastic waterproof layer.

4. The waterproof coating according to claim 1, characterized in that, The acrylic-epoxy resin composite emulsion has an average particle size of 0.1-0.5 μm, a solid content of 45-65%, a glass transition temperature of -20℃ to 10℃, and a viscosity of 500-2000 mPa·s at 25℃.

5. The waterproof coating according to claim 1, characterized in that, The core of the self-healing microcapsule is composed of a self-healing prepolymer generated by reacting dicyclopentadiene and vinyl silicone oil in a molar ratio of 1-2:3 under a 0.3-0.7wt% platinum catalyst; the wall material is a polyvinyl alcohol-sodium alginate composite membrane, with a weight ratio of polyvinyl alcohol to sodium alginate of 2:2-3 in the wall material, and the microcapsule particle size is 40-120μm.

6. The waterproof coating according to claim 1, characterized in that, In the self-cleaning hydrophobic layer, the content of organosilicon resin supporting photocatalytic nano-TiO2 is 10-15 parts by weight, the nano-TiO2 particle size is 10-30nm, and the content accounts for 15-18% of the total weight of the self-cleaning hydrophobic layer.

7. A method for preparing the waterproof coating according to any one of claims 1-6, characterized in that, Includes the following steps: Step 1: Preparation of coatings for each functional layer: Prepare the coatings for each functional layer according to the weight proportions. Step Two: Layered Coating and Curing: Apply the coating in layers, spraying in the following order: high-penetration crystalline layer, elastic waterproof layer, and self-cleaning hydrophobic layer. The spraying pressure is 0.2-0.3 MPa. The high-penetration crystalline layer is heat-cured at 60-85℃ for 1.5-2 hours. When the coating hardness reaches Shore A 25-30, the elastic waterproof layer is applied. The elastic waterproof layer requires interface strengthening treatment. After interface strengthening treatment, the hydrophobic layer is sprayed. The initial curing temperature of the hydrophobic layer is 60-70℃, and the time is 1-1.5 hours. Control the amount of each layer sprayed to achieve the corresponding thickness. Step 3: Interface strengthening treatment: When the elastic layer is cured at a temperature of 70-75 degrees Celsius and the hardness reaches Shore A15-20, a hydrophobic layer is sprayed to allow the silicone resin to penetrate into the gaps between the microcapsules to form an interpenetrating network. Step 4: Secondary curing of the hydrophobic layer: After the hydrophobic layer is sprayed, it is cured for 1-1.5 hours at 98-105℃.

8. The preparation method according to claim 7, characterized in that, When preparing the high-penetration crystalline coating, the raw materials are dispersed in 100-150 parts by weight of deionized water and subjected to ultrasonic dispersion treatment for 30-40 minutes.

9. The preparation method according to claim 7, characterized in that, When preparing the elastic layer coating, the acrylic-epoxy resin composite emulsion and self-healing microcapsules are continuously dispersed at a stirring speed of 350-450 rpm for 30-40 minutes, and 35-40 parts by weight of deionized water are added during the dispersion process to adjust the viscosity.

10. The preparation method according to claim 7, characterized in that, When preparing the self-cleaning hydrophobic coating, the organosilicon resin loaded with photocatalytic nano-TiO2 is dissolved in 40-50 parts by weight of anhydrous ethanol, and 1.2-1.8 parts by weight of silane coupling agent is added. After stirring and mixing at 50-60°C for 1-2 hours, nano-TiO2 is added and dispersion is continued for 40-60 minutes.

Images