A superhydrophobic, root-penetration-resistant acrylic waterproof coating and its preparation method

Abstract

This invention relates to the field of waterborne coating composition technology, and discloses a superhydrophobic, root-penetration-resistant acrylic waterproof coating and its preparation method. The acrylic waterproof coating uses an acrylic film-forming emulsion as the film-forming base material and includes layered composite root-barrier hydrophobic particles, inorganic fillers, dispersants, defoamers, thickeners, and water. The layered composite root-barrier hydrophobic particles include root-barrier active agent microcapsule particles, silane coupling sheet shells, and a dual-size hydrophobic silica outer layer. After curing, the coating forms an acrylic waterproof film, which includes a surface hydrophobic enrichment region and a root-barrier region, suitable for high-performance waterproof coatings.

Description

Technical Field

[0001] This invention relates to the field of water-based coating composition technology, and in particular to a superhydrophobic, root-penetration-resistant acrylic waterproof coating and its preparation method. Background Technology

[0002] Acrylic waterproof coatings are common water-based coating compositions, typically using acrylic film-forming emulsions as the main film-forming base material, combined with inorganic fillers, dispersants, defoamers, thickeners, and water. After application and curing, these coatings form a continuous acrylic waterproof film, suitable for building substrates, roof substrates, underground structure surfaces, and other building waterproofing surfaces. Due to the water-based application, continuous film formation, and certain elasticity of acrylic film-forming emulsions, acrylic waterproof coatings have a wide range of applications in building waterproofing materials.

[0003] In green roofs, green base layers, and waterproof areas subject to long-term moisture retention, acrylic waterproof coatings, in addition to basic waterproofing performance, need to maintain a hydrophobic surface in humid environments and prevent plant roots from penetrating and extending into the coating. Existing technologies already include solutions for incorporating root-blocking functionality into acrylic waterproof coatings. For example, patent application CN109082175A discloses a graphene root-blocking waterproof coating. This coating uses acrylic emulsion, graphene oxide aqueous solution, root inhibitor, light calcium carbonate, distilled water, thickener, preservative, and defoamer as its main components. By adding graphene oxide and root inhibitor to the acrylic emulsion system, the root-blocking performance or related mechanical properties of the coating are improved.

[0004] However, in existing waterproof coatings using acrylic film-forming emulsions as the film-forming base, hydrophobic additives, silica fillers, or surface-modified powders added to improve the water repellency of the coating surface usually need to be dispersed in the water-based acrylic emulsion system. Without compatibility dispersion or structural fixation measures, hydrophobic particles may agglomerate, float, or settle during storage, application, or film formation, affecting the uniformity and stability of the hydrophobic structure on the surface of the cured acrylic waterproof coating.

[0005] Meanwhile, for acrylic waterproof coatings used in planting environments or greening substrates, some existing solutions improve root penetration resistance by directly adding root-inhibiting agents, lamellar fillers, or other barrier fillers. When root-inhibiting agents are directly dispersed in acrylic film-forming emulsions, there may be problems of local enrichment, migration, or uneven distribution; when lamellar fillers or inorganic fillers are directly added to the system, they may also form a random distribution state inside the coating film, making their barrier effect greatly affected by the dispersion state and film-forming process.

[0006] Furthermore, in existing acrylic waterproof coatings, hydrophobic components are typically used primarily to improve surface water repellency, while root-barrier agents or fillers are typically used primarily to enhance the ability of plant roots to penetrate and block them. These two components are usually added separately within the acrylic emulsion system. This dispersion method results in a lack of stable correlation between the surface distribution of the hydrophobic components, the internal distribution of the root-barrier agents, and the barrier distribution of the lamellar fillers, thus affecting the stable formation of the hydrophobic structure on the surface and the internal root-barrier structure of the cured acrylic waterproof coating.

[0007] Therefore, existing waterproof coatings using acrylic film-forming emulsions as film-forming base materials still suffer from the problem that hydrophobic silica components, root-barrier active components, and lamellar barrier components are difficult to form a stable and synergistic distribution in acrylic waterproof coatings, thus affecting the stable formation of the hydrophobic structure on the surface and the internal root-barrier structure of the cured acrylic waterproof coating. Summary of the Invention

[0008] To overcome the aforementioned technical deficiencies, the present invention aims to provide a superhydrophobic, root-penetration-resistant acrylic waterproof coating and its preparation method. The present invention employs an acrylic film-forming emulsion as the film-forming base material and introduces a hierarchical composite root-barrier and hydrophobic particle structure composed of root-barrier microcapsule particles, silane-coupled sheet shells, and a dual-size hydrophobic silica outer layer. This allows the cured acrylic waterproof coating to form a surface hydrophobic enrichment zone and an inner root-barrier zone, thereby improving the synergistic distribution stability of the hydrophobic silica component, the root-barrier active component, and the sheet barrier component in the acrylic waterproof coating.

[0009] This invention discloses a superhydrophobic, root-penetration-resistant acrylic waterproof coating, which, by weight, comprises 42-66 parts of acrylic film-forming emulsion, 10-22 parts of layered composite root-barrier hydrophobic particles, 8-24 parts of inorganic filler, 0.3-1.2 parts of dispersant, 0.1-0.8 parts of defoamer, 0.3-1.6 parts of thickener, and 6-20 parts of water;

[0010] The film-forming base material in the superhydrophobic and root-penetration resistant acrylic waterproof coating is composed of acrylic film-forming emulsion;

[0011] The hierarchical composite root-barrier hydrophobic particles include root-barrier activator microcapsule particles, silane coupling sheet shells, and a dual-size hydrophobic silica outer layer. The silane coupling sheet shells include sheet barrier fillers. The silane coupling sheet shells are coated on the outer surface of the root-barrier activator microcapsule particles. The dual-size hydrophobic silica outer layer is fixed on the outer surface of the silane coupling sheet shells and in the sheet gaps formed by the sheet barrier fillers in the silane coupling sheet shells.

[0012] Superhydrophobic, root-penetration-resistant acrylic waterproof coating cures to form an acrylic waterproof film. The acrylic waterproof film includes a surface hydrophobic enrichment zone and a root-barrier zone located inside the surface hydrophobic enrichment zone. A dual-particle-size hydrophobic silica outer layer is distributed in the surface hydrophobic enrichment zone and is at least partially exposed on the surface of the acrylic waterproof film. Root-barrier active agent microcapsule particles and silane coupling sheet shells are embedded in the root-barrier zone.

[0013] Preferably, based on the total mass of the root-inhibiting agent microcapsule particles, silane coupling sheet shells, and dual-size hydrophobic silica outer layer in the hierarchical composite root-inhibiting hydrophobic particles, the root-inhibiting agent microcapsule particles account for 20% to 38%, the silane coupling sheet shells account for 24% to 42%, and the dual-size hydrophobic silica outer layer accounts for 28% to 50%.

[0014] Preferably, the root-inhibiting agent microcapsule particles comprise a root-inhibiting agent core material as the inner core material and an acrylate copolymer shell layer encapsulating the root-inhibiting agent core material. The root-inhibiting agent core material comprises a 2-methyl-4-chlorophenoxypropionate compound, and the root-inhibiting agent core material accounts for 35% to 68% of the mass of the root-inhibiting agent microcapsule particles. The thickness of the acrylate copolymer shell layer is 0.4 to 2.2 μm.

[0015] Preferably, the acrylate copolymer shell contains hydroxy acrylate structural units and silane acrylate structural units; based on the mass of the acrylate copolymer shell, the hydroxy acrylate structural units are 2% to 9%, and the silane acrylate structural units are 1% to 5%.

[0016] Preferably, the sheet barrier filler is fixed to the outer surface of the acrylate copolymer shell by a silane coupling layer; the silane coupling layer is formed of at least one of an aminosilane coupling agent, an epoxysilane coupling agent, or a methacryloxysilane coupling agent.

[0017] Preferably, the sheet barrier filler includes at least one of sericite powder, mica powder, flake wollastonite or flake glass powder, and the average aspect ratio of the sheet barrier filler is 45 to 160; the coverage area ratio of the silane coupling sheet shell is 62% to 96% based on the outer surface area of ​​the root-barrier microcapsule particles.

[0018] Preferably, the dual-particle-size hydrophobic silica outer layer comprises hydrophobic nano-silica and hydrophobic micron-sized silica particles. The hydrophobic nano-silica is fixed in the interlayer gaps formed by the layer barrier filler in the silane coupling layer shell, and the hydrophobic micron-sized silica particles are fixed on the outer surface of the silane coupling layer shell. The median particle size of the hydrophobic nano-silica is 25–90 nm, and the median particle size of the hydrophobic micron-sized silica particles is 1.5–10 μm.

[0019] Preferably, both the surface of the hydrophobic nano-silica and the hydrophobic micron-sized silica particles have a long-chain alkylsilane modified layer, which is formed by alkyltrialkoxysilanes with a carbon chain length of 12 to 18; the long-chain alkylsilane modified layer accounts for 0.8% to 4.5% of the mass of the two-particle-size hydrophobic silica outer layer.

[0020] Preferably, the outer surface of the hierarchical composite root-barrier hydrophobic particles has a polyacrylate anchoring and dispersion layer, which forms a discontinuous coating layer on the outside of the dual-particle-size hydrophobic silica outer layer; the polyacrylate anchoring and dispersion layer accounts for 0.4% to 2.2% of the total mass of the hierarchical composite root-barrier hydrophobic particles after the formation of the polyacrylate anchoring and dispersion layer.

[0021] Preferably, the acrylic film-forming emulsion includes an elastic acrylic film-forming emulsion and a self-crosslinking acrylic film-forming emulsion, wherein the mass ratio of the elastic acrylic film-forming emulsion to the self-crosslinking acrylic film-forming emulsion is 1:0.35 to 1:0.95; and the self-crosslinking acrylic film-forming emulsion contains acetylacetoxy structural units.

[0022] Preferably, by weight, it further includes 0.15 to 0.75 parts of an acylhydrazine crosslinking agent, which includes at least one of adipic acid dihydrazine, carbamate dihydrazine, or sebacyl hydrazine; after the superhydrophobic root-penetration resistant acrylic waterproof coating is cured, the acylhydrazine crosslinking agent forms a crosslinking network with the acetylacetoxy structural units in the self-crosslinking acrylic film-forming emulsion.

[0023] Preferably, the thickness of the surface hydrophobic enrichment region is 25–100 μm; in the cross-sectional image of the surface hydrophobic enrichment region, the cross-sectional area of ​​the dual-size hydrophobic silica outer layer accounts for 60%–88% of the total cross-sectional area of ​​the hierarchical composite root-barrier hydrophobic particles in the surface hydrophobic enrichment region.

[0024] Preferably, in the cross-sectional image of the root barrier zone, the number of sheet barrier fillers with an angle of 0° to 35° between the long axis direction of the sheet barrier filler and the plane direction of the acrylic waterproof coating surface accounts for 58% to 92% of the total number of sheet barrier fillers in the root barrier zone.

[0025] In view of this, the present invention also provides a method for preparing a superhydrophobic, root-penetration-resistant acrylic waterproof coating, comprising the following steps:

[0026] Preparation of root-barrier activator microcapsule particles;

[0027] The root-inhibiting agent microcapsule particles are dispersed in a silane coupling agent hydrolysate used to form a silane coupling layer, and a sheet-like barrier filler is added to fix the sheet-like barrier filler on the outer surface of the root-inhibiting agent microcapsule particles, thus obtaining sheet-like coated microcapsules.

[0028] Sheet-coated microcapsules are dispersed in an alcohol-water mixture containing long-chain alkyl silanes. Nano-silica and micron-sized silica particles are added to fix the nano-silica and micron-sized silica particles on the outer surface of the sheet-coated microcapsules and in the interlayer gaps formed by the sheet-barrier filler in the sheet-coated microcapsules, thus obtaining hierarchical composite root-barrier hydrophobic particles.

[0029] Water, dispersant, inorganic filler and part of defoamer are dispersed to obtain inorganic filler slurry;

[0030] An acrylic film-forming emulsion is added to an inorganic filler slurry and mixed to obtain an acrylic-based slurry.

[0031] The layered composite root-barrier hydrophobic particles, the remaining defoamer, and the thickener are added to the acrylic slurry for low-shear mixing. In the preparation of a superhydrophobic and root-penetration-resistant acrylic waterproof coating including an acylhydrazine crosslinking agent, the acylhydrazine crosslinking agent, the layered composite root-barrier hydrophobic particles, the remaining defoamer, and the thickener are added to the acrylic slurry for low-shear mixing to obtain the superhydrophobic and root-penetration-resistant acrylic waterproof coating.

[0032] Preferably, the pH value of the silane coupling agent hydrolysate is 4.0–5.5, and the mixing temperature of the sheet barrier filler and root-inhibiting activator microcapsule particles is 25–45°C; in the alcohol-water mixture containing long-chain alkyl silane, the mass ratio of alcohol to water is 3:1–9:1, and after adding nano-silica and micron-sized silica particles, the mixing temperature with the sheet-coated microcapsules is 35–60°C; the low-shear mixing speed is 200–550 r / min.

[0033] Compared with existing technologies, the above technical solution has the following advantages:

[0034] 1. This invention uses an acrylic film-forming emulsion as the film-forming base material and introduces hierarchical composite root-barrier hydrophobic particles into it. This allows the root-barrier active agent microcapsule particles, silane coupling sheet shells, and a dual-size hydrophobic silica outer layer to form an interconnected composite particle structure. This avoids the distribution instability caused by the separate dispersion of the root-barrier active component, sheet barrier component, and hydrophobic silica component in the acrylic waterproof coating, and is beneficial to improving the structural stability of the cured acrylic waterproof coating film.

[0035] 2. This invention fixes a dual-particle-size hydrophobic silica outer layer to the outer surface and interlayer gaps of a silane coupling layer shell, and distributes it in the surface hydrophobic enrichment area of ​​the cured acrylic waterproof coating film, with at least a portion exposed on the coating film surface. This facilitates the formation of a stable micro-nano hydrophobic structure on the surface of the acrylic waterproof coating film, thereby improving the hydrophobicity of the coating film surface and its hydrophobic retention ability after water immersion.

[0036] 3. In this invention, the root-repellent surfactant is placed in the root-repellent surfactant microcapsule particles, and the silane-coupled sheet shell is coated on the outer surface of the root-repellent surfactant microcapsule particles. This allows the root-repellent surfactant component and the sheet barrier component to form a more stable combination distribution inside the coating film, which helps to reduce the risk of local enrichment and migration of the root-repellent surfactant in the acrylic waterproof coating film and improves the long-term root-repellent stability of the coating film. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the overall structure of the hierarchical composite root-barrier hydrophobic particles in this invention;

[0039] Figure 2 This is a schematic diagram of the structure of the root-barrier activator microcapsule particles in this invention;

[0040] Figure 3 This is a schematic diagram of the structure of the silane coupling sheet shell covering the outer surface of the root-inhibiting agent microcapsule particles in this invention;

[0041] Figure 4 This is a schematic diagram of the structure of the dual-particle-size hydrophobic silica outer layer fixed to the silane coupling sheet shell in this invention;

[0042] Figure 5 This is a schematic diagram of the cross-sectional partition structure of the acrylic waterproof coating film formed by the curing of the superhydrophobic and root-penetration resistant acrylic waterproof coating in this invention.

[0043] Figure 6 This is a flowchart illustrating the preparation process of the superhydrophobic, root-penetration-resistant acrylic waterproof coating of this invention.

[0044] Figure 7 This is a schematic diagram illustrating the statistical method for the cross-sectional structural parameters of the acrylic waterproof coating in this invention;

[0045] Figure 8 This is a comparison chart of the performance test results of the embodiments and comparative examples in this invention.

[0046] Figure label:

[0047] 100 is a layered composite root-barrier hydrophobic particle, 110 is a root-barrier agent microcapsule particle, 111 is a root-barrier agent core material, 112 is an acrylate copolymer shell, 120 is a silane coupling sheet shell, 121 is a sheet barrier filler, 122 is a silane coupling layer, 123 is a sheet gap, 130 is a dual-size hydrophobic silica outer layer, 131 is hydrophobic nano-silica, 132 is hydrophobic micron-sized silica particles, 133 is a long-chain alkyl silane modified layer, 140 is a polyacrylate anchoring dispersion layer, 200 is an acrylic waterproof coating, 210 is a surface hydrophobic enrichment zone, 220 is a root-barrier zone, 230 is the surface of the acrylic waterproof coating, 300 is the statistical field of view of the cross section, and A is the angle between the long axis direction of the sheet barrier filler and the plane direction of the acrylic waterproof coating surface. Detailed Implementation

[0049] The following description, in conjunction with the accompanying drawings and specific embodiments, further illustrates the superhydrophobic, root-penetration-resistant acrylic waterproof coating and its preparation method. The following embodiments are used to illustrate the implementation methods, parameter ranges, testing methods, and technical effects of each technical feature, and should not be construed as limiting this application. Without departing from the technical concept of using acrylic film-forming emulsions as film-forming base materials and improving the coating structure distribution through hierarchical composite root-barrier hydrophobic particles, those skilled in the art can make equivalent substitutions or conventional adjustments to the specific material types, proportions, and process conditions.

[0050] like Figure 1 As shown, the hierarchical composite root-barrier hydrophobic particles 100 include root-barrier activator microcapsule particles 110, silane coupling sheet shells 120, and a dual-size hydrophobic silica outer layer 130. The silane coupling sheet shell 120 coats the outer surface of the root-barrier activator microcapsule particles 110, and the dual-size hydrophobic silica outer layer 130 is fixed to the outer surface of the silane coupling sheet shell 120 and in the interlayer gaps 123 formed by the sheet barrier filler 121 within the silane coupling sheet shell 120. The polyacrylate anchoring dispersion layer 140 can form a discontinuous coating layer outside the dual-size hydrophobic silica outer layer 130 to improve the dispersion state of the hierarchical composite root-barrier hydrophobic particles 100 in an aqueous acrylic film-forming emulsion system. Figure 2 The internal structure of the root-inhibiting agent microcapsule particle 110 is shown. The root-inhibiting agent microcapsule particle 110 includes a root-inhibiting agent core material 111 as the inner core material and an acrylate copolymer shell 112 covering the root-inhibiting agent core material 111. Figure 3 The encapsulation structure of the silane coupling sheet shell 120 is shown, wherein the sheet barrier filler 121 is fixed to the outer surface of the acrylate copolymer shell 112 through the silane coupling layer 122. Figure 4 The structure of a dual-size hydrophobic silica outer layer 130 is shown, which includes hydrophobic nano-silica 131 and hydrophobic micron-sized silica particles 132. Figure 5 The cross-sectional partition structure of the acrylic waterproof coating 200 is shown. The cured acrylic waterproof coating 200 includes a surface hydrophobic enrichment region 210 and a root barrier region 220 located inside the surface hydrophobic enrichment region 210. Figure 6 The preparation process of a superhydrophobic, root-penetration-resistant acrylic waterproof coating is shown. Figure 7 The statistical method for coating cross-section is shown. Figure 8 The method for comparing the performance test results of the embodiments and the comparative examples is shown.

[0051] In this embodiment, an acrylic film-forming emulsion is used as the film-forming base material for the superhydrophobic, root-penetration-resistant acrylic waterproof coating. The film-forming base material in the superhydrophobic, root-penetration-resistant acrylic waterproof coating is composed of an acrylic film-forming emulsion. The acrylic film-forming emulsion can be an elastic acrylic film-forming emulsion, a self-crosslinking acrylic film-forming emulsion, or a combination of both. The solid content of the elastic acrylic film-forming emulsion can be 48% to 58%, the glass transition temperature can be -35°C to -15°C, and the minimum film-forming temperature can be 0°C to 8°C; the solid content of the self-crosslinking acrylic film-forming emulsion can be 45% to 55%, the glass transition temperature can be -20°C to 0°C, and it contains acetylacetoxy structural units. When using a blend of elastic and self-crosslinking acrylic film-forming emulsions, the mass ratio of the elastic to self-crosslinking acrylic film-forming emulsions can be 1:0.35 to 1:0.95. The acylhydrazide crosslinking agent can be at least one of adipic acid dihydrazide, carbamate dihydrazide, or sebacyl hydrazide. The acylhydrazide crosslinking agent is added as a crosslinking auxiliary component and is not used as a film-forming base material. After the superhydrophobic, root-penetration-resistant acrylic waterproof coating cures, the acylhydrazide crosslinking agent forms a crosslinking network with the acetylacetoxy structural units in the self-crosslinking acrylic film-forming emulsion.

[0052] In this embodiment, the root-inhibiting agent core material 111 can be a 2-methyl-4-chlorophenoxypropionate compound, specifically isooctyl 2-methyl-4-chlorophenoxypropionate. The acrylate copolymer shell 112 can be formed by emulsion polymerization or suspension polymerization of methyl methacrylate, butyl acrylate, hydroxyacrylate monomers, and silane acrylate monomers. The hydroxyacrylate structural units can be derived from hydroxyethyl acrylate or hydroxyethyl methacrylate, and the silane acrylate structural units can be derived from γ-methacryloyloxypropyltrimethoxysilane. Introducing hydroxyacrylate and silane acrylate structural units into the acrylate copolymer shell 112 facilitates the fixation of the sheet barrier filler 121 to the outer surface of the root-inhibiting agent microcapsule particles 110 through the silane coupling layer 122.

[0053] In this embodiment, the root-inhibiting agent microcapsule particles 110 can be prepared as follows: A root-inhibiting agent core material 111, methyl methacrylate, butyl acrylate, hydroxyethyl acrylate, and γ-methacryloyloxypropyltrimethoxysilane are mixed to form an oil phase, and an aqueous solution of polyvinyl alcohol is used as the aqueous phase. The mixture is sheared and emulsified at 6000 r / min to 10000 r / min for 5 min to 15 min to obtain an emulsion system containing the root-inhibiting agent core material 111. Subsequently, a water-soluble initiator is added at 65℃ to 80℃ to carry out a polymerization reaction for 2 h to 5 h, causing an acrylate copolymer shell layer 112 to form on the outside of the root-inhibiting agent core material 111. After the reaction, the mixture is centrifuged, washed, and vacuum dried at 40℃ to 50℃ to obtain the root-inhibiting agent microcapsule particles 110.

[0054] In one specific embodiment, the mass concentration of the polyvinyl alcohol aqueous solution is 1.0% to 3.0%, and the mass ratio of the oil phase to the aqueous phase is 1:3 to 1:8; the water-soluble initiator is ammonium persulfate or potassium persulfate, and its amount is 0.3% to 1.2% of the total mass of the acrylate monomers. In the oil phase, the mass ratio of the root-inhibiting activator core material 111 to the total amount of acrylate monomers is 1:0.5 to 1:1.8; the mass ratio of methyl methacrylate to butyl acrylate is 1:0.6 to 1:1.5. By adjusting the above ratios, the content of the root-inhibiting activator core material 111 and the thickness of the acrylate copolymer shell layer 112 fall within the corresponding ranges. The contents of hydroxyl acrylate structural units and silane acrylate structural units in the acrylate copolymer shell layer 112 in Examples 1 to 5 are shown in Table 2.

[0055] In this embodiment, the lamellar barrier filler 121 can be at least one of sericite powder, mica powder, flake wollastonite, or flake glass powder. The silane coupling layer 122 can be formed from at least one of aminosilane coupling agent, epoxysilane coupling agent, or methacryloxysilane coupling agent. The average aspect ratio of the lamellar barrier filler 121 can be 45 to 160, and the coverage area ratio of the silane coupling lamellar shell 120 can be 62% to 96% based on the outer surface area of ​​the root-barrier microcapsule particles 110. In forming the silane coupling sheet shell 120, the silane coupling agent is added to an alcohol-water mixture, the pH is adjusted to 4.0–5.5, and hydrolysis is carried out for 20–60 minutes to obtain a silane coupling agent hydrolysate. The root-inhibiting agent microcapsule particles 110 are dispersed in the silane coupling agent hydrolysate, and then sheet barrier filler 121 is added. The mixture is stirred at 25–45°C for 30–90 minutes to fix the sheet barrier filler 121 to the outer surface of the root-inhibiting agent microcapsule particles 110 through the silane coupling layer 122. After solid-liquid separation and drying, sheet-coated microcapsules are obtained.

[0056] In this embodiment, the dual-particle-size hydrophobic silica outer layer 130 includes hydrophobic nano-silica 131 and hydrophobic micron-sized silica particles 132. The median particle size of the hydrophobic nano-silica 131 is 25 nm to 90 nm, and the median particle size of the hydrophobic micron-sized silica particles 132 is 1.5 μm to 10 μm. Both the surface of the hydrophobic nano-silica 131 and the hydrophobic micron-sized silica particles 132 have a long-chain alkylsilane modified layer 133, which can be formed from alkyltrialkoxysilanes with a carbon chain length of 12 to 18. Specifically, layered microcapsules are dispersed in an alcohol-water mixture containing long-chain alkyl silanes, with an alcohol-to-water mass ratio of 3:1 to 9:1. Nano-silica and micron-sized silica particles are then added, and the mixture is stirred at 35°C to 60°C for 1 to 3 hours. Under the action of the long-chain alkyl silanes, the nano-silica and micron-sized silica particles form hydrophobic nano-silica 131 and hydrophobic micron-sized silica particles 132, which are then fixed on the outer surface of the layered microcapsules and in the interlayer gaps 123 formed by the layered barrier filler 121 within the layered microcapsules. After the reaction is complete, solid-liquid separation, washing, and drying are performed to obtain particles with a dual-size hydrophobic silica outer layer 130. Subsequently, a polyacrylate dispersant solution is sprayed or dropped onto the surface of these particles. After low-speed mixing and drying, a polyacrylate anchoring dispersion layer 140 forms a discontinuous coating layer outside the dual-size hydrophobic silica outer layer 130, resulting in a layered composite root-barrier hydrophobic particle 100.

[0057] In one specific embodiment, the polyacrylate anchoring dispersion layer 140 is formed using sodium polyacrylate or ammonium polyacrylate with a number average molecular weight of 3000-12000, and the mass concentration of the polyacrylate dispersant solution is 5%-15%. When the polyacrylate dispersant solution is added by spraying, the spraying time is 5-20 minutes. After spraying, it is mixed at a low speed of 100-300 rpm for 10-30 minutes and then dried at 40-60°C, so that the polyacrylate anchoring dispersion layer 140 accounts for 0.4%-2.2% of the total mass of the layered composite root-barrier hydrophobic particles 100 after the formation of the polyacrylate anchoring dispersion layer 140.

[0058] In this embodiment, the preparation sequence of the superhydrophobic root-penetration resistant acrylic waterproof coating is as follows: First, root-barrier agent microcapsule particles 110 are prepared. Then, a silane coupling agent hydrolysate is used to fix the sheet-like barrier filler 121 on the outer surface of the root-barrier agent microcapsule particles 110 to form sheet-like coated microcapsules. Next, the sheet-like coated microcapsules are dispersed in an alcohol-water mixture containing long-chain alkyl silanes, and nano-silica and micron-sized silica particles are added to fix the nano-silica and micron-sized silica particles on the outer surface of the sheet-like coated microcapsules and in the sheet-like gaps 123 formed by the sheet-like barrier filler 121 within the sheet-like coated microcapsules to obtain layered composite root-barrier hydrophobic particles 100. Then, water, dispersant, inorganic filler, and part of the defoamer are dispersed to obtain an inorganic filler slurry. Subsequently, an acrylic film-forming emulsion is added to obtain an acrylic base slurry. Finally, the layered composite root-barrier hydrophobic particles 100, the remaining defoamer, and the thickener are added to the acrylic base slurry and mixed under low shear. When the superhydrophobic and root-penetration-resistant acrylic waterproof coating contains hydrazine crosslinking agent, the hydrazine crosslinking agent, the layered composite root-barrier hydrophobic particles 100, the remaining defoamer and thickener are added to the acrylic base slurry for low-shear mixing.

[0059] In this embodiment, the inorganic filler can be at least one of heavy calcium carbonate, light calcium carbonate, talc, kaolin, barium sulfate, or wollastonite. The dispersant can be at least one of polycarboxylate dispersant or polyacrylate dispersant. The defoamer can be at least one of mineral oil defoamer or polyether-modified siloxane defoamer. The thickener can be at least one of associative polyurethane thickener, alkali-swellable acrylic thickener, or cellulose ether thickener. In this example, the inorganic filler is a mixture of heavy calcium carbonate and talc, the dispersant is a polycarboxylate dispersant, the defoamer is a mineral oil defoamer, and the thickener is an alkali-swellable acrylic thickener.

[0060] In this embodiment, the structural parameters of the hierarchical composite root-barrier hydrophobic particles 100, the surface hydrophobic enrichment region 210, and the root-barrier region 220 are statistically analyzed using cross-sectional images. Cross-sectional samples were prepared using liquid nitrogen brittle fracture, and the cross-sections were observed using a scanning electron microscope after gold sputtering. Three cross-sections were randomly selected from each sample, and five fields of view were selected from each cross-section. The magnification of each field of view ranged from 1000x to 5000x, and the statistical results were averaged. For the embodiment, statistics were performed based on the hierarchical composite root-barrier hydrophobic particles 100, the dual-particle-size hydrophobic silica outer layer 130, and the sheet-like barrier filler 121. For the comparative example and prior art control example, comparative statistics were performed based on the identifiable hydrophobic particles, root-barrier components, or sheet-like fillers within the same cross-sectional area. This comparative statistical analysis reflects the influence of different component addition methods on the cross-sectional distribution of the coating.

[0061] The coverage area ratio is calculated using the following formula:

[0062]

[0063] In the formula, This represents the coverage area ratio of the silane coupling sheet shell. The area of ​​the outer surface of the root-inhibiting surfactant microcapsule particles covered by silane coupling sheets is expressed in square micrometers. The surface area of ​​the root-inhibiting surfactant microcapsule particles is expressed in square micrometers.

[0064] The thickness of the surface hydrophobic enrichment zone is measured from the surface of the acrylic waterproof coating inward along the cross-sectional normal direction. The cross-sectional area ratio of the dual-particle-size hydrophobic silica outer layer is calculated using the following formula:

[0065]

[0066] In the formula, The cross-sectional area ratio of the hydrophobic silica outer layer with two particle sizes. This represents the cross-sectional area of ​​the two-particle-size hydrophobic silica outer layer within the surface hydrophobic enrichment region, expressed in square micrometers. The total cross-sectional area of ​​the hierarchical composite root-barrier hydrophobic particles within the surface hydrophobic enrichment zone is expressed in square micrometers.

[0067] The proportion of oriented layer barrier fillers is calculated according to the following formula:

[0068]

[0069] In the formula, The proportion of oriented layered barrier fillers. The number of lamellar barrier fillers in the root-barrier zone with an angle of 0° to 35° between the long axis direction and the plane direction of the acrylic waterproof coating surface. This refers to the total number of lamellar barrier packings within the root barrier zone. The total number of lamellar barrier packings counted for each sample shall not be less than 250.

[0070] The contact angle retention rate after water immersion is calculated using the following formula:

[0071]

[0072] In the formula, The contact angle retention rate after water immersion. The water contact angle after immersion in deionized water at 25°C for 168 hours is expressed in degrees. The initial water contact angle is expressed in degrees.

[0073] The cumulative release rate of the root-barrier surfactant is calculated using the following formula:

[0074]

[0075] In the formula, This represents the cumulative release rate of the root-inhibiting surfactant. The mass of root-inhibiting surfactant that enters the extract within a set time, expressed in milligrams. The initial mass of the root-inhibiting surfactant in the coated sample is expressed in milligrams.

[0076] The formula-converted mass is calculated using the following formula:

[0077]

[0078] In the formula, The actual mass of a component in the target batch, in kilograms; This refers to the mass fraction of the component. It is the sum of the mass fractions of all components in the paint formulation; The total mass of the target batch, in kilograms.

[0079] The mass of the main structure in the hierarchical composite root-barrier hydrophobic particles is calculated according to the following formula:

[0080]

[0081] In the formula, The total mass of the root-inhibiting agent microcapsule particles, silane coupling sheet shell, and dual-size hydrophobic silica outer layer is expressed in kilograms. The actual mass of the target batch of mid-level composite root-barrier hydrophobic particles is expressed in kilograms. This represents the actual mass of the polyacrylate anchoring dispersion layer, expressed in kilograms.

[0082] The actual mass of the polyacrylate anchoring dispersion layer is calculated using the following formula:

[0083]

[0084] In the formula, The actual mass of the polyacrylate anchoring dispersion layer is expressed in kilograms. The actual mass of the target batch of mid-level composite root-barrier hydrophobic particles is expressed in kilograms. The mass ratio of the polyacrylate anchoring dispersion layer to the total mass of the hierarchical composite root-barrier hydrophobic particles after the formation of the polyacrylate anchoring dispersion layer.

[0085] In this embodiment, the water contact angle is used as the criterion for determining the superhydrophobic surface. When the initial water contact angle is not less than 150°, the surface of the cured acrylic waterproof coating is considered to have formed a superhydrophobic state. In the preferred embodiment, the roll-off angle is not greater than 15°.

[0086] In the root penetration resistance test, the coating to be tested was applied to the surface of a cement mortar substrate, with a wet film thickness controlled at 2.0 mm. The substrate was cured for 7 days at 23℃ and 50% relative humidity to obtain the sample. The sample was placed at the bottom of a culture container containing nutrient soil, with the coating surface facing the direction of plant root growth. Ryegrass seeds were sown above the sample, and the soil moisture content was maintained at 30%–45%. The culture temperature was 23℃–28℃. Three parallel samples were set for each group. After 90 days of culture, the samples were removed, and it was observed whether the plant roots penetrated the acrylic waterproof coating and reached the surface of the cement mortar substrate. No root channels penetrating the coating were recorded as non-penetration; root channels penetrating the coating but with no more than three penetration points were recorded as partial penetration; and more than three penetration points were recorded as full penetration.

[0087] In the cumulative release rate test of the root-inhibiting surfactant, the cured coating was cut into 50mm × 50mm samples, and the initial mass of the root-inhibiting surfactant in the samples was recorded. The samples were then placed in 100mL of deionized water and extracted at 25℃. Extracts were collected at 7, 14, and 28 days, filtered through a 0.45μm filter membrane, and the content of the root-inhibiting surfactant in the extract was determined by high-performance liquid chromatography (HPLC). The cumulative release rate at the corresponding time points was calculated according to the formula for the cumulative release rate of the root-inhibiting surfactant. For HPLC detection, a 70:30 volume ratio of methanol and water was used as the mobile phase, the detection wavelength was 280nm, and the injection volume was 10μL. For comparative examples where the root-inhibiting surfactant was added directly, the initial mass of the surfactant was calculated based on the actual amount added; for examples and comparative examples containing microcapsule particles of the root-inhibiting surfactant, the initial mass of the surfactant was calculated based on the content of the surfactant core material.

[0088] In the tensile property test, the cured acrylic waterproof coating was cut into dumbbell-shaped specimens and placed at 23℃ and 50% relative humidity for 24 hours before testing. The tensile speed was 200 mm / min, and 5 specimens were tested in each group. The average value was taken as the tensile strength and elongation at break. In the water absorption test, the specimens were immersed in deionized water at 23℃ for 24 hours, and the water absorption rate was calculated based on the mass change before and after immersion. The impermeability test conditions were 0.3 MPa for 30 minutes. In the low-temperature flexibility test, the specimens were kept at -20℃ for 2 hours and then bent around a round bar of a specified diameter. The appearance of cracks in the coating was observed.

[0089] Example 2 is provided as a calculation example. In Example 2, the components are: acrylic film-forming emulsion (54.0 parts), hierarchical composite root-barrier hydrophobic particles (16.0 parts), inorganic filler (16.0 parts), dispersant (0.7 parts), defoamer (0.4 parts), thickener (0.9 parts), water (12.0 parts), and hydrazide crosslinking agent (0.35 parts). The total mass fraction of each component in the coating formulation is:

[0090]

[0091] When the total target batch mass is 100 kg, the actual mass of the acrylic film-forming emulsion in Example 2 is:

[0092]

[0093] The actual mass of the hierarchical composite root-barrier hydrophobic particles in Example 2 is:

[0094]

[0095] The actual mass of the inorganic packing in Example 2 is:

[0096]

[0097] The actual mass of the dispersant in Example 2 is:

[0098]

[0099] The actual mass of the defoamer in Example 2 is:

[0100]

[0101] The actual mass of the thickener in Example 2 is:

[0102]

[0103] The actual mass of water in Example 2 is:

[0104]

[0105] The actual mass of the acylhydrazide crosslinking agent in Example 2 is:

[0106]

[0107] The above conversion results are used to illustrate the calculation method when converting the mass fraction formula into actual production batches. Those skilled in the art can scale up or down the formula composition proportionally according to the target batch size.

[0108] In Example 2, the polyacrylate anchoring dispersion layer content was 1.2%, and the actual mass of the layered composite root-barrier hydrophobic particles was 15.94 kg. Therefore, the actual mass of the polyacrylate anchoring dispersion layer was:

[0109]

[0110] In Example 2, the total mass of the root-inhibiting surfactant microcapsule particles, the silane coupling sheet shell, and the dual-size hydrophobic silica outer layer is:

[0111]

[0112] In Example 2, based on the total mass of the root-inhibiting agent microcapsule particles, the silane coupling sheet shell, and the dual-size hydrophobic silica outer layer, the proportion of the root-inhibiting agent microcapsule particles was 30.2%, the proportion of the silane coupling sheet shell was 31.8%, and the proportion of the dual-size hydrophobic silica outer layer was 38.0%. Therefore, the actual mass of the root-inhibiting agent microcapsule particles was:

[0113]

[0114] The actual mass of the silane coupling sheet shell is:

[0115]

[0116] The actual mass of the two-particle-size hydrophobic silica outer layer is:

[0117]

[0118] The sum of the above three parts' mass and the actual mass of the polyacrylate anchoring dispersion layer is:

[0119]

[0120] This result is consistent with the actual mass of 15.94 kg of the target batch of mid-level composite root-barrier hydrophobic particles.

[0121] In Example 2, the root-inhibiting agent core material accounts for 50.5% of the mass of the root-inhibiting agent microcapsule particles, and the actual mass of the root-inhibiting agent microcapsule particles is 4.756 kg. Therefore, the actual mass of the root-inhibiting agent core material is:

[0122]

[0123] The actual mass of the acrylate copolymer shell is:

[0124]

[0125] In Example 2, the acrylic film-forming emulsion is composed of an elastic acrylic film-forming emulsion and a self-crosslinking acrylic film-forming emulsion, with a mass ratio of 1:0.55. The actual mass of the acrylic film-forming emulsion in the target batch is 53.81 kg, therefore the actual mass of the elastic acrylic film-forming emulsion is:

[0126]

[0127] The actual mass of the self-crosslinking acrylic film-forming emulsion is:

[0128]

[0129] In Example 2, the external surface area of ​​the root-inhibiting surfactant microcapsule particles was found to be 5000 μm² using scanning electron microscopy images, of which 4020 μm² was covered by the silane coupling sheet shell. Therefore, the coverage area ratio of the silane coupling sheet shell is:

[0130]

[0131] In Example 2, the total cross-sectional area of ​​the hierarchical composite root-barrier hydrophobic particles in the surface hydrophobic enrichment region was statistically determined to be 25000 μm², of which the cross-sectional area of ​​the dual-size hydrophobic silica outer layer was 19200 μm². Therefore, the proportion of the cross-sectional area of ​​the dual-size hydrophobic silica outer layer is:

[0132]

[0133] In Example 2, 400 sheet barrier fillers were counted within the root barrier zone. Among them, 314 sheet barrier fillers had an angle of 0° to 35° between their long axis and the plane of the acrylic waterproof coating surface. Therefore, the orientation ratio of the sheet barrier fillers is:

[0134]

[0135] In Example 2, the thicknesses of the surface hydrophobic enrichment region measured in five random fields of view were 58 μm, 62 μm, 64 μm, 60 μm, and 66 μm, respectively. Therefore, the average thickness of the surface hydrophobic enrichment region is:

[0136]

[0137] In Example 2, the initial water contact angles measured at five test points were 156°, 158°, 160°, 157°, and 159°, respectively. The average initial water contact angle is:

[0138]

[0139] In Example 2, after immersion in deionized water at 25°C for 168 hours, the water contact angle was measured to be 151°, while the initial water contact angle was 158°. Therefore, the contact angle retention rate after water immersion is:

[0140]

[0141] In Example 2, the initial mass of the root-inhibiting surfactant in the coating sample was 100 mg. After 7 days of extraction, the mass of the root-inhibiting surfactant entering the extract was 4.2 mg; after 14 days of extraction, the mass of the root-inhibiting surfactant entering the extract was 7.1 mg; and after 28 days of extraction, the mass of the root-inhibiting surfactant entering the extract was 10.5 mg. The cumulative release rate of the root-inhibiting surfactant over 7 days was:

[0142]

[0143] The cumulative release rate of the root-inhibiting surfactant over 14 days was:

[0144]

[0145] The cumulative release rate of the root-inhibiting surfactant over 28 days was:

[0146]

[0147] The above calculation examples demonstrate that the formulation mass fraction, the internal composition of the layered composite root-barrier hydrophobic particles, the statistical parameters of the coating cross-section, and the performance test indicators can all be obtained through clearly defined data sources and calculation formulas. Those skilled in the art can use the above calculation methods to perform formulation conversion, structural statistics, and performance evaluation of different batches of superhydrophobic, root-penetration-resistant acrylic waterproof coatings.

[0148] In Example 1, by weight, 42.0 parts of acrylic film-forming emulsion, 10.0 parts of layered composite root-barrier hydrophobic particles, 8.0 parts of inorganic filler, 0.3 parts of dispersant, 0.1 parts of defoamer, 0.3 parts of thickener, and 20.0 parts of water were used. The acrylic film-forming emulsion was an elastic acrylic film-forming emulsion with a solid content of 50% and a glass transition temperature of -28°C. The core material of the root-barrier microcapsule particles was isooctyl 2-methyl-4-chlorophenoxypropionate, and the hydroxyl acrylate structural units in the acrylate copolymer shell were 2.2%, while the silane acrylate structural units were 1.1%. The sheet barrier filler was sericite powder with an average aspect ratio of 48; the silane coupling layer was formed by an aminosilane coupling agent. In the dual-size hydrophobic silica outer layer, the median particle size of the hydrophobic nano-silica is 26 nm, the median particle size of the hydrophobic micron-sized silica particles is 1.6 μm, and the long-chain alkylsilane modified layer is formed by dodecyltrimethoxysilane.

[0149] In Example 2, the following components were used by weight: 54.0 parts of acrylic film-forming emulsion, 16.0 parts of layered composite root-barrier hydrophobic particles, 16.0 parts of inorganic filler, 0.7 parts of dispersant, 0.4 parts of defoamer, 0.9 parts of thickener, and 12.0 parts of water. The acrylic film-forming emulsion was a combination of elastic acrylic film-forming emulsion and self-crosslinking acrylic film-forming emulsion, with a mass ratio of 1:0.55. The self-crosslinking acrylic film-forming emulsion contained acetylacetoxy structural units. In this example, 0.35 parts of adipic acid dihydrazide were also added. The sheet barrier filler was mica powder with an average aspect ratio of 102; the silane coupling layer was formed by a methacryloyloxysilane coupling agent. In the dual-size hydrophobic silica outer layer, the median particle size of the hydrophobic nano-silica is 55 nm, the median particle size of the hydrophobic micron-sized silica particles is 5.2 μm, and the long-chain alkylsilane modified layer is formed by hexadecyltrimethoxysilane.

[0150] In Example 3, the following components were used by weight: 66.0 parts of acrylic film-forming emulsion, 22.0 parts of layered composite root-barrier hydrophobic particles, 24.0 parts of inorganic filler, 1.2 parts of dispersant, 0.8 parts of defoamer, 1.6 parts of thickener, and 6.0 parts of water. The acrylic film-forming emulsion was a combination of elastic acrylic film-forming emulsion and self-crosslinking acrylic film-forming emulsion, with a mass ratio of 1:0.95. The self-crosslinking acrylic film-forming emulsion contained acetylacetoxy structural units. 0.75 parts of sebacic acid dihydrazide were also added in this example. The layered barrier filler was flake-shaped glass powder with an average aspect ratio of 158; the silane coupling layer was formed by an epoxy silane coupling agent. In the dual-particle-size hydrophobic silica outer layer, the median particle size of the hydrophobic nano-silica was 88 nm, the median particle size of the hydrophobic micron-sized silica particles was 9.8 μm, and the long-chain alkyl silane modified layer was formed by octadecyltrimethoxysilane.

[0151] In Example 4, the following components were used by weight: 50.0 parts of acrylic film-forming emulsion, 15.0 parts of layered composite root-barrier hydrophobic particles, 14.0 parts of inorganic filler, 0.6 parts of dispersant, 0.3 parts of defoamer, 0.8 parts of thickener, and 14.0 parts of water. The acrylic film-forming emulsion used was an elastic acrylic film-forming emulsion. The layered barrier filler was flake-shaped wollastonite with an average aspect ratio of 86. The silane coupling layer was formed by aminosilane coupling agent and methacryloxysilane coupling agent in a 1:1 mass ratio. In the dual-particle-size hydrophobic silica outer layer, the median particle size of the hydrophobic nano-silica was 48 nm, and the median particle size of the hydrophobic micron-sized silica particles was 4.6 μm. The long-chain alkylsilane modified layer was formed by dodecyltrimethoxysilane and octadecyltrimethoxysilane in a 1:1 mass ratio.

[0152] In Example 5, the following components were used by weight: 58.0 parts of acrylic film-forming emulsion, 18.0 parts of layered composite root-barrier hydrophobic particles, 20.0 parts of inorganic filler, 0.9 parts of dispersant, 0.5 parts of defoamer, 1.2 parts of thickener, and 10.0 parts of water. The acrylic film-forming emulsion was a combination of elastic acrylic film-forming emulsion and self-crosslinking acrylic film-forming emulsion, with a mass ratio of 1:0.35. The self-crosslinking acrylic film-forming emulsion contained acetylacetoxy structural units. 0.15 parts of carbazide were also added in this example. The sheet barrier filler was a mixed sheet barrier filler composed of sericite powder and mica powder in a mass ratio of 1:1, with an average aspect ratio of 74. The silane coupling layer was formed by an aminosilane coupling agent. In the dual-particle-size hydrophobic silica outer layer, the median particle size of the hydrophobic nano-silica is 37 nm, the median particle size of the hydrophobic micron-sized silica particles is 3.5 μm, and the long-chain alkylsilane modified layer is formed by hexadecyltrimethoxysilane.

[0153] Comparative Example 1 used a common acrylic waterproof coating without adding layered composite root-barrier hydrophobic particles, only adding conventional inorganic fillers, dispersants, defoamers, thickeners, and water. Comparative Example 2 directly added a root-barrier surfactant to the same acrylic film-forming emulsion system as Example 2, without preparing root-barrier surfactant microcapsule particles. Comparative Example 3 directly added hydrophobic silica modified with long-chain alkylsilane to the same acrylic film-forming emulsion system as Example 2, and simultaneously added the same mass of root-barrier surfactant microcapsule particles as in Example 2, but without forming a dual-size hydrophobic silica outer layer. Comparative Example 4 added corresponding functional particles to the same acrylic film-forming emulsion system as Example 2. These functional particles contained root-barrier surfactant microcapsule particles and hydrophobic silica particles, but the layered barrier filler was not fixed to the outer surface of the root-barrier surfactant microcapsule particles through a silane coupling layer. Comparative Example 5: Root-barrier microcapsule particles, layered barrier fillers, and hydrophobic silica particles were added separately to an acrylic film-forming emulsion system without pre-forming a layered composite root-barrier hydrophobic particle structure. The prior art comparative example follows the graphene root-barrier waterproof coating concept disclosed in application publication number CN109082175A, preparing a root-barrier waterproof coating using acrylic emulsion, graphene oxide aqueous solution, root-barrier agent, light calcium carbonate, water, thickener, preservative, and defoamer, and comparing it with the example under the same test conditions.

[0154] Table 1 lists the coating formulations of the examples, comparative examples, and prior art comparative examples. All components are expressed in parts by weight.

[0155] Table 1 Sample Composition Information

[0156] Example 1 42 10 8 0.3 0.1 0.3 20 0 none Example 2 54 16 16 0.7 0.4 0.9 12 0.35 none Example 3 66 22 24 1.2 0.8 1.6 6 0.75 none Example 4 50 15 14 0.6 0.3 0.8 14 0 none Example 5 58 18 20 0.9 0.5 1.2 10 0.15 none Comparative Example 1 54 0 24 0.7 0.4 0.9 12 0 none Comparative Example 2 54 0 16 0.7 0.4 0.9 12 0.35 Directly add root inhibitor Comparative Example 3 54 16 16 0.7 0.4 0.9 12 0.35 Hydrophobic silica is added directly without forming a hydrophobic silica outer layer with two particle sizes. Comparative Example 4 54 16 16 0.7 0.4 0.9 12 0.35 Add corresponding functional particles that do not form silane coupling sheet shells Comparative Example 5 54 16 16 0.7 0.4 0.9 12 0.35 The three functional components were added separately. Comparison of existing technologies 54 0 16 0.7 0.4 0.9 12 0 Graphene oxide aqueous solution and root inhibitor

[0157] Table 2 lists the structural parameters of the hierarchical composite root-barrier hydrophobic particles in the embodiments. The proportions of the root-barrier activator microcapsule particles, silane coupling sheet shells, and dual-size hydrophobic silica outer layer are calculated based on their total mass; the contents of hydroxy acrylate structural units and silane acrylate structural units are calculated based on the mass of the acrylate copolymer shell.

[0158] Table 2 Sample Component Ratios and Related Parameters

[0159] Example 1 20.5 29.7 49.8 0.5 36 0.5 2.2 1.1 48 63.5 26 1.6 0.9 Example 2 30.2 31.8 38 1.2 50.5 1.2 5 3 102 80.4 55 5.2 2.6 Example 3 37.6 34 28.4 2.1 67.2 2.1 8.8 4.8 158 95 88 9.8 4.4 Example 4 28 34.5 37.5 1 49 1 4.5 2.2 86 78.2 48 4.6 2.1 Example 5 33.5 28 38.5 1.5 55 1.5 6.2 3.5 74 84.6 37 3.5 3

[0160] Table 3 lists the main preparation process parameters. The pH value of the silane coupling agent hydrolysate is controlled at 4.0–5.5 to enable the silane coupling agent to form a hydrolysis state suitable for fixing the layered barrier filler; low-shear mixing is used to reduce the breakage of the root-barrier microcapsule particles and maintain the outer layer structure of the hierarchical composite root-barrier hydrophobic particles.

[0161] Table 3 Sample Parameter Information

[0162] Example 1 1 1∶3 0.3 4.1 25 3∶1 35 200 25 Example 2 2 1∶5 0.7 4.8 35 6∶1 45 360 20 Example 3 3 1∶8 1.2 5.5 45 9∶1 60 550 18 Example 4 1.8 1∶4 0.6 4.6 32 5∶1 42 320 22 Example 5 2.5 1∶6 0.9 5 38 7∶1 50 420 20

[0163] Table 4 lists the statistical results of the cross-sectional structure of the cured acrylic waterproof coating. The coating was applied to the surface of a cement mortar substrate, with a wet film thickness controlled at 2.0 mm. It was cured for 7 days at 23°C and 50% relative humidity. Cross-sectional observation and statistics were then performed on the resulting acrylic waterproof coating. In the examples, the surface hydrophobic enrichment zone, the dual-particle-size hydrophobic silica outer layer, and the sheet-like barrier filler were statistically analyzed according to the above definitions. Comparative examples and prior art examples were statistically analyzed based on the identifiable hydrophobic particles or sheet-like fillers in the same cross-sectional area.

[0164] Table 4 Sample Performance Parameters

[0165] Example 1 28 61.5 59.2 Example 2 62 76.8 78.5 Example 3 96 87 90.4 Example 4 55 74.1 75.3 Example 5 70 80.5 82.6 Comparative Example 1 8 12.4 21.3 Comparative Example 2 20 28.6 35.2 Comparative Example 3 42 45 32.8 Comparative Example 4 48 56.5 40.1 Comparative Example 5 45 49.8 46.5 Comparison of existing technologies 18 22.7 38

[0166] Table 5 lists the comprehensive performance test results of the examples, comparative examples, and prior art control examples. Water contact angle and roll-off angle were measured using a contact angle meter, with 5 test points taken for each sample and the average value calculated. Water absorption rate was determined based on the change in immersion mass. Impermeability was tested under conditions of 0.3 MPa and 30 min. Tensile strength and elongation at break were performed using the methods described above. Root penetration resistance was tested using a ryegrass root penetration simulation experiment, observing whether penetration occurred after 90 days. The cumulative release rate of the root-inhibiting surfactant was detected by high-performance liquid chromatography after extraction with deionized water at 25°C.

[0167] Table 5 Sample Performance Test Table

[0168] Example 1 151 14 90.7 5.8 impermeable 2.3 610 No cracks at -20℃ Not penetrated 14.8 Example 2 158 8 95.6 3.6 impermeable 3 540 No cracks at -20℃ Not penetrated 10.5 Example 3 166 4 94 3.1 impermeable 3.6 420 No cracks at -20℃ Not penetrated 8.6 Example 4 156 9 93.5 3.9 impermeable 2.8 560 No cracks at -20℃ Not penetrated 11.2 Example 5 160 7 96.2 3.4 impermeable 3.2 510 No cracks at -20℃ Not penetrated 9.8 Comparative Example 1 103 42 72.8 12.5 impermeable 1.8 660 No cracks at -20℃ penetrate — Comparative Example 2 126 31 78.4 9.6 impermeable 2 590 No cracks at -20℃ Local penetration 33.5 Comparative Example 3 143 19 70.6 8.2 impermeable 2.1 570 No cracks at -20℃ Local penetration 25 Comparative Example 4 138 22 76.8 7.5 impermeable 2.2 555 No cracks at -20℃ Local penetration 20.6 Comparative Example 5 145 18 79.3 7 impermeable 2.4 530 No cracks at -20℃ Local penetration 24.8 Comparison of existing technologies 118 36 73.1 10.2 impermeable 2.1 610 No cracks at -20℃ Not penetrated 29.4

[0169] As shown in Tables 1 to 5, all examples 1 to 5 used acrylic film-forming emulsions as film-forming base materials, and constructed an interconnected composite particle structure by using hierarchical composite root-barrier hydrophobic particles 100 to integrate root-barrier microcapsule particles 110, silane coupling sheet shells 120, and dual-size hydrophobic silica outer layers 130. Compared with ordinary acrylic waterproof coatings, coatings with directly added root-barrier agents, coatings with directly added hydrophobic silica, coatings with unfixed sheet barrier fillers, and coatings with three types of functional components added separately, the acrylic waterproof coating 200 in these examples can form a surface hydrophobic enrichment region 210 with a thickness of 25μm to 100μm, and the dual-size hydrophobic silica outer layer 130 has a high cross-sectional area ratio within the surface hydrophobic enrichment region 210; at the same time, the sheet barrier filler 121 has a high proportion of low-angle orientation in the root-barrier region 220.

[0170] Example 2, as a preferred embodiment, uses a formulation of 54.0 parts acrylic film-forming emulsion, 16.0 parts layered composite root-barrier hydrophobic particles 100, and 16.0 parts inorganic filler. The surface hydrophobic enrichment zone 210 has a thickness of 62 μm, the cross-sectional area of ​​the dual-particle-size hydrophobic silica outer layer 130 accounts for 76.8%, and the proportion of the sheet-like barrier filler 121 with an included angle of 0°–35° is 78.5%. Its initial water contact angle is 158°, the roll-off angle is 8°, the contact angle retention rate after 168 hours is 95.6%, the root penetration resistance result after 90 days is no penetration, and the cumulative release rate of the root-barrier active agent after 28 days is 10.5%. These results indicate that the layered composite root-barrier hydrophobic particles 100 can enable a stable and synergistic distribution of the hydrophobic silica component, the root-barrier active component, and the sheet-like barrier component in the acrylic waterproof coating, thereby improving the surface hydrophobic stability and internal root-barrier stability of the cured acrylic waterproof coating 200.

[0171] Comparative Example 5 involved adding root-barrier microcapsule particles, sheet-like barrier fillers, and hydrophobic silica particles to an acrylic film-forming emulsion system, without pre-forming a hierarchical composite root-barrier hydrophobic particle 100. Although this comparative example contained functional components similar to those in Example 2, its corresponding hydrophobic particle cross-sectional area ratio was 49.8%, the sheet-like barrier filler ratio (0°–35° angle) was 46.5%, the initial water contact angle was 145°, the contact angle retention rate after 168 hours was 79.3%, and the 90-day root penetration resistance result showed only localized penetration. These results indicate that simply adding the root-barrier active component, sheet-like barrier component, and hydrophobic silica component to an acrylic film-forming emulsion system is insufficient to obtain the same coating partitioning structure and performance stability as the hierarchical composite root-barrier hydrophobic particle 100.

[0172] The prior art comparative example was prepared using the graphene root-barrier waterproof coating concept mentioned in the background art. While it can provide root-barrier properties to some extent, its initial water contact angle, roll-off angle, and contact angle retention rate after 168 hours are all lower than those of Example 2, and its cumulative release rate of the root-barrier active agent after 28 days is higher than that of Example 2. These results indicate that in acrylic waterproof coatings, relying solely on graphene oxide and the direct addition of root-barrier agents is insufficient to simultaneously ensure the stability of the surface hydrophobic structure, the distribution stability of the root-barrier active components, and the stability of the internal root-barrier barrier structure.

[0173] In summary, this embodiment uses an acrylic film-forming emulsion as the film-forming base material and disperses the hierarchical composite root-barrier hydrophobic particles 100 in the acrylic film-forming emulsion system, so that the cured acrylic waterproof coating 200 forms a surface hydrophobic enrichment region 210 and a root-barrier region 220 located inside the surface hydrophobic enrichment region 210. This structure allows the dual-particle-size hydrophobic silica outer layer 130 to mainly participate in the formation of the surface hydrophobic structure, and allows the root-barrier active agent microcapsule particles 110 and silane coupling sheet shells 120 to mainly participate in the formation of the internal root-barrier structure, thereby improving the synergistic distribution stability of the hydrophobic silica component, the root-barrier active component, and the sheet barrier component in the acrylic waterproof coating.

[0174] In one embodiment, the preparation method of the superhydrophobic, root-penetration-resistant acrylic waterproof coating includes the sequential steps of preparing root-inhibiting agent microcapsule particles, preparing sheet-coated microcapsules, preparing layered composite root-inhibiting hydrophobic particles, preparing inorganic filler slurry, preparing acrylic base slurry, and low-shear mixing to form the coating. This preparation method focuses on the addition and dispersion of acrylic film-forming emulsions as the film-forming base material, without involving the synthesis reaction control of the acrylic polymer main resin. The resulting product is still a water-based acrylic waterproof coating with acrylic film-forming emulsions as the film-forming base material.

[0175] Specifically, root-inhibiting surfactant microcapsule particles are first prepared. A root-inhibiting surfactant core material, methyl methacrylate, butyl acrylate, hydroxyethyl acrylate, and γ-methacryloyloxypropyltrimethoxysilane are mixed to form an oil phase. A 1.0%–3.0% (w / w) polyvinyl alcohol aqueous solution is used as the aqueous phase, with a oil-to-water ratio of 1:3–1:8. The mixture is sheared and emulsified at 6000–10000 r / min for 5–15 min to obtain an emulsion system containing the root-inhibiting surfactant core material. The emulsion system is then heated to 65–80°C, and ammonium persulfate or potassium persulfate is added as a water-soluble initiator. The amount of the water-soluble initiator is 0.3%–1.2% of the total mass of the acrylate monomers, and the reaction is maintained at this temperature for 2–5 h, allowing an acrylate copolymer shell to form on the outside of the root-inhibiting surfactant core material. After the reaction, the mixture is centrifuged, washed with deionized water, and vacuum dried at 40–50°C to obtain the root-inhibiting surfactant microcapsule particles. By adjusting the mass ratio of the root-inhibiting surfactant core material to the total amount of acrylate monomers in the oil phase to 1:0.5 to 1:1.8, and adjusting the mass ratio of methyl methacrylate to butyl acrylate to 1:0.6 to 1:1.5, the content of the root-inhibiting surfactant core material and the thickness of the acrylate copolymer shell are kept within a predetermined range.

[0176] Then, sheet-coated microcapsules are prepared. A silane coupling agent is added to an alcohol-water mixture, the pH is adjusted to 4.0–5.5, and hydrolyzed for 20–60 minutes to obtain a silane coupling agent hydrolysate for forming the silane coupling layer. The silane coupling agent can be at least one of aminosilane coupling agents, epoxysilane coupling agents, or methacryloxysilane coupling agents. The root-inhibiting agent microcapsule particles are dispersed in the silane coupling agent hydrolysate, stirred for 10–30 minutes, and then a sheet-like barrier filler is added. Mixing continues at 25–45°C for 30–90 minutes, allowing the sheet-like barrier filler to be fixed to the outer surface of the root-inhibiting agent microcapsule particles through the silane coupling layer, resulting in sheet-coated microcapsules. The sheet-like barrier filler can be at least one of sericite powder, mica powder, flaky wollastonite, or flake glass powder, with an average aspect ratio of 45–160.

[0177] Subsequently, hierarchical composite root-barrier hydrophobic particles were prepared. Sheet-coated microcapsules were dispersed in an alcohol-water mixture containing long-chain alkyl silanes, wherein the mass ratio of alcohol to water in the alcohol-water mixture was 3:1 to 9:1, and the long-chain alkyl silanes were alkyltrialkoxysilanes with a carbon chain length of 12 to 18. Nano-silica and micron-sized silica particles were added to the system, and the mixture was stirred at 35°C to 60°C for 1 to 3 hours. This allowed the nano-silica and micron-sized silica particles to be modified by the long-chain alkyl silanes, forming hydrophobic nano-silica and hydrophobic micron-sized silica particles, which were then fixed on the outer surface of the sheet-coated microcapsules and in the interlayer spaces formed by the sheet-barrier filler within the sheet-coated microcapsules. After the reaction, solid-liquid separation, washing with the alcohol-water mixture, and drying were performed to obtain particles with a dual-size hydrophobic silica outer layer. Further, the polyacrylate dispersant solution is sprayed or dripped onto the surface of the particles with the dual-size hydrophobic silica outer layer, mixed at a low speed of 100 r / min to 300 r / min for 10 min to 30 min, and dried at 40℃ to 60℃, so that the polyacrylate anchoring dispersion layer forms a discontinuous coating layer on the outside of the dual-size hydrophobic silica outer layer, thus obtaining a hierarchical composite root-barrier hydrophobic particle.

[0178] In the preparation of the water-based acrylic base material, water, dispersant, inorganic filler, and a portion of defoamer are added to a dispersion container and dispersed at 800 r / min to 1500 r / min for 20 min to 40 min to obtain an inorganic filler slurry. The inorganic filler can be at least one of heavy calcium carbonate, light calcium carbonate, talc, kaolin, barium sulfate, or wollastonite. The dispersant can be at least one of polycarboxylate dispersant or polyacrylate dispersant. The defoamer can be at least one of mineral oil defoamer or polyether-modified siloxane defoamer.

[0179] Subsequently, the acrylic film-forming emulsion is added to the inorganic filler slurry and mixed at 400 r / min to 800 r / min for 15 min to 30 min to obtain an acrylic-based slurry. The acrylic film-forming emulsion is the film-forming base material for superhydrophobic, root-penetration-resistant acrylic waterproof coatings. When the acrylic film-forming emulsion includes an elastic acrylic film-forming emulsion and a self-crosslinking acrylic film-forming emulsion, the elastic acrylic film-forming emulsion and the self-crosslinking acrylic film-forming emulsion are premixed at a set mass ratio before being added to the inorganic filler slurry. The self-crosslinking acrylic film-forming emulsion contains acetylacetoxy structural units.

[0180] Finally, the hierarchical composite root-barrier hydrophobic particles, the remaining defoamer, and the thickener are added to the acrylic-based slurry and mixed at a low shear rate of 200 r / min to 550 r / min for 18 min to 30 min to obtain a superhydrophobic, root-penetration-resistant acrylic waterproof coating. When it is necessary to prepare a superhydrophobic, root-penetration-resistant acrylic waterproof coating containing an acylhydrazine crosslinking agent, the acylhydrazine crosslinking agent is added together with the hierarchical composite root-barrier hydrophobic particles, the remaining defoamer, and the thickener to the acrylic-based slurry for low shear mixing. The acylhydrazine crosslinking agent can be at least one of adipate dihydrazide, carbamate dihydrazide, or sebacylhydrazine. The low shear mixing can reduce the breakage of the root-barrier active agent microcapsule particles and maintain the structural state of the silane coupling sheet shell and the dual-size hydrophobic silica outer layer in the hierarchical composite root-barrier hydrophobic particles.

[0181] In one specific preparation example, an oil phase was prepared by taking the root-inhibiting activator core material, methyl methacrylate, butyl acrylate, hydroxyethyl acrylate, and γ-methacryloxypropyltrimethoxysilane. The oil phase was mixed with a 2.0% (w / w) polyvinyl alcohol aqueous solution at a mass ratio of 1:5 and sheared and emulsified at 8000 r / min for 10 min. Subsequently, ammonium persulfate was added at 72 °C, and the reaction was maintained at this temperature for 3 h. After centrifugation and washing, the mixture was vacuum dried at 45 °C to obtain root-inhibiting activator microcapsule particles. The methacryloxysilane coupling agent was added to the alcohol-water mixture, the pH was adjusted to 4.8, and after hydrolysis for 40 min, the root-inhibiting activator microcapsule particles were added. Then, mica powder was added, and the mixture was mixed at 35 °C for 60 min to obtain sheet-coated microcapsules. Layered coated microcapsules were added to an alcohol-water mixture containing hexadecyltrimethoxysilane at a mass ratio of 6:1. Nano-sized silica with a median particle size of 55 nm and micron-sized silica particles with a median particle size of 5.2 μm were added. The mixture was mixed at 45 °C for 2 h. After solid-liquid separation and drying, the surface was discontinuously coated with a 10% sodium polyacrylate solution to obtain hierarchical composite root-barrier hydrophobic particles.

[0182] In the specific preparation example above, 12.0 parts of water, 0.7 parts of polycarboxylate dispersant, 16.0 parts of inorganic filler, and a portion of mineral oil defoamer were added to a dispersion container and dispersed at 1200 r / min for 30 min to obtain an inorganic filler slurry. Subsequently, 54.0 parts of acrylic film-forming emulsion were added and mixed at 600 r / min for 20 min to obtain an acrylic-based slurry. Then, 16.0 parts of layered composite root-barrier hydrophobic particles, 0.35 parts of adipic acid dihydrazide, the remaining mineral oil defoamer, and an alkali-swellable acrylic thickener were added and mixed at 360 r / min under low shear for 20 min to obtain a superhydrophobic, root-penetration-resistant acrylic waterproof coating. In this preparation example, the pH value of the silane coupling agent hydrolysate, the mixing temperature of the layered barrier filler and root-barrier activator microcapsule particles, the alcohol-to-water mass ratio, the hydrophobic outer layer formation temperature, and the low-shear mixing speed were all within the range described above.

[0183] The superhydrophobic, root-penetration-resistant acrylic waterproof coating obtained by the above preparation method can form an acrylic waterproof film after application and curing. Because the hierarchical composite root-barrier hydrophobic particles have completed the sequential construction of root-barrier microcapsule particles, silane coupling sheet shells, and a dual-size hydrophobic silica outer layer before being added to the acrylic base slurry, the cured acrylic waterproof coating can form a surface hydrophobic enrichment zone and a root-barrier zone located inside the surface hydrophobic enrichment zone. This results in a more stable and synergistic distribution of the hydrophobic silica component, the root-barrier active component, and the sheet barrier component in the acrylic waterproof coating.

[0184] It should be noted that the embodiments of the present invention have better implementability and are not intended to limit the present invention in any way. Any person skilled in the art may use the above-disclosed technical content to change or modify it into equivalent effective embodiments. However, any modifications or equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A superhydrophobic, root-penetration-resistant acrylic waterproof coating, characterized in that, By weight, it comprises 42-66 parts of acrylic film-forming emulsion, 10-22 parts of hierarchical composite root-barrier hydrophobic particles, 8-24 parts of inorganic filler, 0.3-1.2 parts of dispersant, 0.1-0.8 parts of defoamer, 0.3-1.6 parts of thickener, and 6-20 parts of water; The film-forming base material in the superhydrophobic and root-penetration resistant acrylic waterproof coating is composed of the acrylic film-forming emulsion. The hierarchical composite root-barrier hydrophobic particles include root-barrier activator microcapsule particles, silane coupling sheet shells, and a dual-size hydrophobic silica outer layer. The silane coupling sheet shells include sheet barrier fillers. The silane coupling sheet shells are coated on the outer surface of the root-barrier activator microcapsule particles. The dual-size hydrophobic silica outer layer is fixed on the outer surface of the silane coupling sheet shells and in the sheet gaps formed by the sheet barrier fillers within the silane coupling sheet shells. The superhydrophobic, root-penetration-resistant acrylic waterproof coating cures to form an acrylic waterproof film. The acrylic waterproof film includes a surface hydrophobic enrichment zone and a root-barrier zone located inside the surface hydrophobic enrichment zone. The dual-particle-size hydrophobic silica outer layer is distributed in the surface hydrophobic enrichment zone and is at least partially exposed on the surface of the acrylic waterproof film. The root-barrier active agent microcapsule particles and the silane coupling sheet shell are embedded in the root-barrier zone.

2. The superhydrophobic, root-penetration-resistant acrylic waterproof coating according to claim 1, characterized in that, Based on the total mass of the root-barrier activator microcapsule particles, silane coupling sheet shells, and dual-size hydrophobic silica outer layer in the hierarchical composite root-barrier hydrophobic particles, the root-barrier activator microcapsule particles account for 20% to 38%, the silane coupling sheet shells account for 24% to 42%, and the dual-size hydrophobic silica outer layer accounts for 28% to 50%.

3. The superhydrophobic, root-penetration-resistant acrylic waterproof coating according to claim 2, characterized in that, The root-inhibiting agent microcapsule particles comprise a root-inhibiting agent core material as an inner core material and an acrylate copolymer shell layer encapsulating the root-inhibiting agent core material. The root-inhibiting agent core material comprises a 2-methyl-4-chlorophenoxypropionate compound. The root-inhibiting agent core material accounts for 35% to 68% of the mass of the root-inhibiting agent microcapsule particles, and the thickness of the acrylate copolymer shell layer is 0.4 to 2.2 μm.

4. The superhydrophobic, root-penetration-resistant acrylic waterproof coating according to claim 3, characterized in that, The acrylate copolymer shell contains hydroxy acrylate structural units and silane acrylate structural units; based on the mass of the acrylate copolymer shell, the hydroxy acrylate structural units are 2% to 9%, and the silane acrylate structural units are 1% to 5%.

5. The superhydrophobic, root-penetration-resistant acrylic waterproof coating according to claim 4, characterized in that, The sheet barrier filler is fixed to the outer surface of the acrylate copolymer shell by a silane coupling layer; the silane coupling layer is formed of at least one of an aminosilane coupling agent, an epoxysilane coupling agent, or a methacryloxysilane coupling agent.

6. The superhydrophobic, root-penetration-resistant acrylic waterproof coating according to claim 5, characterized in that, The sheet barrier filler includes at least one of sericite powder, mica powder, flaky wollastonite, or flake glass powder, and the average aspect ratio of the sheet barrier filler is 45 to 160; the coverage area ratio of the silane coupling sheet shell is 62% to 96% based on the outer surface area of ​​the root-barrier activator microcapsule particles.

7. The superhydrophobic, root-penetration-resistant acrylic waterproof coating according to claim 5, characterized in that, The dual-particle-size hydrophobic silica outer layer comprises hydrophobic nano-silica and hydrophobic micron-sized silica particles. The hydrophobic nano-silica is fixed in the interlayer gaps formed by the layer barrier filler in the silane coupling layer shell, and the hydrophobic micron-sized silica particles are fixed on the outer surface of the silane coupling layer shell. The median particle size of the hydrophobic nano-silica is 25–90 nm, and the median particle size of the hydrophobic micron-sized silica particles is 1.5–10 μm.

8. The superhydrophobic, root-penetration-resistant acrylic waterproof coating according to claim 7, characterized in that, Both the hydrophobic nano-silica and the hydrophobic micron-sized silica particles have a long-chain alkylsilane modified layer on their surface. The long-chain alkylsilane modified layer is formed by alkyltrialkoxysilanes with a carbon chain length of 12 to 18. The long-chain alkylsilane modified layer accounts for 0.8% to 4.5% of the mass of the dual-particle-size hydrophobic silica outer layer.

9. A method for preparing a superhydrophobic, root-penetration-resistant acrylic waterproof coating as described in any one of claims 1 to 8, characterized in that, Includes the following steps: Preparation of root-barrier activator microcapsule particles; The root-barrier activator microcapsule particles are dispersed in a silane coupling agent hydrolysate used to form a silane coupling layer, and a sheet-like barrier filler is added to fix the sheet-like barrier filler to the outer surface of the root-barrier activator microcapsule particles, thereby obtaining sheet-like coated microcapsules. The sheet-coated microcapsules are dispersed in an alcohol-water mixture containing long-chain alkyl silanes. Nano-silica and micron-sized silica particles are added to fix the nano-silica and micron-sized silica particles on the outer surface of the sheet-coated microcapsules and in the interlayer gaps formed by the sheet-barrier filler in the sheet-coated microcapsules, thereby obtaining a hierarchical composite root-barrier hydrophobic particle. Water, dispersant, inorganic filler and part of defoamer are dispersed to obtain inorganic filler slurry; An acrylic film-forming emulsion is added to the inorganic filler slurry and mixed to obtain an acrylic-based slurry; The layered composite root-barrier hydrophobic particles, the remaining defoamer, and the thickener are added to the acrylic slurry for low-shear mixing. In preparing a superhydrophobic, root-penetration-resistant acrylic waterproof coating including an acylhydrazine crosslinking agent, the acylhydrazine crosslinking agent, the layered composite root-barrier hydrophobic particles, the remaining defoamer, and the thickener are added to the acrylic slurry for low-shear mixing to obtain the superhydrophobic, root-penetration-resistant acrylic waterproof coating.

10. The preparation method according to claim 9, characterized in that, The pH value of the silane coupling agent hydrolysate is 4.0–5.5; the mixing temperature of the sheet barrier filler and the root-barrier activator microcapsule particles is 25–45°C; in the alcohol-water mixture containing long-chain alkyl silane, the mass ratio of alcohol to water is 3:1–9:1; after adding the nano-silica and the micron-sized silica particles, the mixing temperature with the sheet-coated microcapsules is 35–60°C; the rotation speed of the low-shear mixing is 200–550 r / min.

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