Self-repairing polymer emulsion cement waterproof coating and preparation method thereof

Abstract

The application relates to the technical field of building waterproof materials, and discloses a self-repairing polymer emulsion cement waterproof coating and a preparation method thereof. The coating comprises liquid material and powder material in an isolated package. Polyethylene glycol monomethyl ether, urea and a composite metal crosslinking agent composed of ammonium zirconium carbonate and titanium lactate are introduced into the liquid material, and N, N-dimethyl ethanolamine is used to maintain a high-alkali dormant environment to guarantee long-term heat storage stability; tartaric acid potassium sodium and slow-release inorganic self-repairing particles with an outer polyethylene glycol isolation film are added to the powder material, so that the mixed slurry has sufficient construction application period. When the film is damaged and water seeps, the dissolved components are dissociated to promote the slip and recombination of polymer chain segments to the cracks, the crosslinking agent reconstructs the coordination network, and the inorganic particles release silicate ions to generate calcium silicate hydrate gel in situ. Through the synergistic mechanism of the organic and inorganic, the self-healing of microcracks is effectively realized, and the impermeability and mechanical strength of the coating film are recovered.

Description

Technical Field

[0001] This invention relates to the field of building waterproofing materials technology, specifically to a self-healing polymer emulsion cement waterproofing coating and its preparation method. Background Technology

[0002] Waterproofing in building construction is a crucial aspect of ensuring structural safety and extending the building's lifespan. Polymer cement waterproofing coatings, as a typical water-based environmentally friendly material, combine the flexibility and deformability of polymer films with the long-term durability of cement-based inorganic materials, making them widely used in waterproofing projects for various building areas such as basements, roofs, and bathrooms.

[0003] Traditional polymer cement waterproof coatings generally employ a two-component formulation system, primarily consisting of a liquid component made from water-based emulsions such as acrylic esters or styrene-acrylic resins, and a powder component composed of inorganic fillers such as ordinary silicate cement, quartz sand, and heavy calcium carbonate powder. During on-site construction, workers mix the liquid and powder components in a specific ratio to form a uniform slurry, which is then applied to the surface of the building substrate. As the moisture within the slurry evaporates and the cement hydration reaction progresses, the dispersed polymer particles gradually aggregate and fuse into a continuous organic macromolecular network. The hardened cement hydration products interweave and fill this organic network, and through physical interpenetration, ultimately form a cured coating film with basic impermeability.

[0004] However, due to the unpredictable shrinkage and settlement of concrete substrates during their service life, conventional coatings after curing are prone to developing penetrating microcracks when subjected to external forces exceeding their yield strength. To address this cracking problem, some solutions attempt to introduce metal complex crosslinking agents into the liquid to strengthen the network skeleton. However, these free, highly active metal ions tend to dissociate prematurely during room temperature storage. They spontaneously undergo irreversible crosslinking reactions with the free carboxyl groups on the side chains of the emulsion molecules, causing an abnormal increase in the viscosity of the liquid and even clumping and spoilage within the packaging container. Furthermore, mechanical water addition and stirring cause the instantaneous release of high-concentration silicate ions, which not only react violently with the free calcium ions in the early stages of cement hydration but also severely disrupt the electrostatic repulsion balance of the emulsion particles, leading to large-scale demulsification and flocculation of the mixed slurry in a very short time. Therefore, this invention provides a self-healing polymer emulsion cement waterproof coating and its preparation method to overcome the shortcomings of existing technologies. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a self-healing polymer emulsion cement waterproof coating and its preparation method, which solves the problem that existing polymer cement waterproof coatings cannot heal microcracks after being subjected to external forces, leading to waterproof system impermeability failure and a significant decrease in secondary tensile strength.

[0006] To achieve the above objectives, the present invention provides the following technical solution: In a first aspect, the present invention provides a self-healing polymer emulsion cement waterproof coating, which adopts the following technical solution: A self-healing polymer emulsion cement waterproof coating includes a liquid component and a powder component in separate packaging, wherein the mass ratio of the liquid component to the powder component is 1:1.2 to 1.6. The liquid is made from the following components in parts by weight: 15 to 25 parts deionized water, 2 to 5 parts polyethylene glycol monomethyl ether, 0.3 to 1.0 parts urea, 0.4 to 1.7 parts N,N-dimethylethanolamine, 40 to 60 parts styrene-acrylic emulsion, 2.0 to 4.0 parts ammonium zirconium carbonate aqueous solution, 0.8 to 2.0 parts titanium lactate aqueous solution, 0.1 to 0.3 parts polyether-modified polysiloxane defoamer, and 0.05 to 0.15 parts isothiazolinone preservative; The powder is made from the following components in parts by weight: 35 to 45 parts of rapid-hardening sulfoaluminate cement, 30 to 40 parts of quartz sand, 10 to 20 parts of slow-release inorganic self-healing particles, 4 to 8 parts of silica fume, 0.1 to 0.3 parts of dry powdered polycarboxylate superplasticizer, and 0.3 to 0.65 parts of potassium sodium tartrate.

[0007] By adopting the above technical solution, N,N-dimethylethanolamine can provide a highly alkaline environment during the long-term storage of the liquid material. This alkaline environment keeps ammonium zirconium carbonate and titanium lactate in a stable ionic complexation state, directly preventing premature cross-linking polymerization between the highly reactive metal cations and the free carboxyl groups on the side chains of the styrene-acrylic emulsion molecules. When the liquid material is mixed with the powder, the potassium sodium tartrate on the powder side preferentially complexes the trace calcium ions dissolved from the rapid-hardening sulfoaluminate cement, preventing free calcium ions from disrupting the electrostatic repulsion balance on the surface of the emulsion particles, thereby extending the actual usable construction time of the mixed slurry.

[0008] During the coating and film formation process, water evaporates continuously, and N,N-dimethylethanolamine also volatilizes, leading to a gradual decrease in the alkalinity of the system. Ammonium zirconate carbonate and titanium lactate begin to dissociate, releasing zirconium and titanium ions. These free metal cations then coordinate with the anionic carboxyl groups on the styrene-acrylic emulsion molecular chains, forming a dynamically reversible composite metal crosslinked framework.

[0009] During actual service, the coating may develop through-cracks due to substrate deformation. Once external moisture seeps in along the cracks, water molecules will dissolve the polyethylene glycol monomethyl ether and urea components pre-placed in the liquid. These dissolved substances form localized high-concentration water-retaining micro-regions in the fracture surface area and competitively bind to hydrogen bond acceptors and donors on the polymer molecular chains. The original solidified inter-chain hydrogen bonds are dissociated, causing the local glass transition temperature of the polymer at the crack interface to decrease.

[0010] As the polymer molecular chains slide across the crack, the previously dissociated free metal cations and side-chain carboxyl groups reassociate, re-establishing a cross-interfacial metal coordination network on the fracture surface. Simultaneously, the inorganic system's repair mechanism is activated; the infiltrated moisture dissolves the polyethylene glycol coating on the surface of the slow-release inorganic self-healing particles, exposing the internally loaded lithium silicate solution. The dissolved silicate ions react with calcium ions continuously released from the hydration of the surrounding cement matrix, forming hydrated calcium silicate gel directly in situ within the crack.

[0011] Preferably, the slow-release inorganic self-healing particles are made from the following components in parts by weight: 8 to 12 parts of calcined diatomaceous earth powder, 4 to 6 parts of lithium silicate aqueous solution, and 2.5 to 3.5 parts of polyethylene glycol.

[0012] Preferably, in the slow-release inorganic self-healing particles, the lithium silicate is loaded inside the porous structure of the calcined diatomaceous earth powder, and the polyethylene glycol is formed by hot-melt coating to form a physical isolation film covering the surface of the calcined diatomaceous earth.

[0013] By employing the above technical solution, lithium silicate solution is pre-adsorbed into the pores of the porous calcined diatomaceous earth, and a closed isolation layer of polyethylene glycol is formed on the outside of the particles. To address the premature reaction defects of conventional inorganic repair agents, this method blocks the large-scale release of lithium silicate during the initial mixing stage of the powder and liquid, avoiding instantaneous contact between silicate ions and early-stage free calcium ions in the cement, thus preventing uncontrollable early-strength curing of the slurry. With this physical protection, the self-healing inorganic phase only triggers a slow-release dissolution reaction when the coating cures and encounters external moisture penetration again.

[0014] Preferably, the aqueous solutions of ammonium zirconium carbonate and titanium lactate in the liquid are diluted with deionized water by 3 times.

[0015] By employing the above technical solution, the composite crosslinking agent is pre-diluted quantitatively, effectively reducing the local concentration gradient generated in the initial reaction system during the dropwise addition. Directly adding a high concentration of crosslinking agent can easily lead to microscopic demulsification or even flocculation and aggregation in the contact area with the organic emulsion. Dilution treatment avoids this risk, ensuring the overall dispersion uniformity and compatibility of the finished liquid product.

[0016] Preferably, in the liquid material, the mass ratio of polyethylene glycol monomethyl ether to urea is 5:1 to 20:3; and the mass ratio of the aqueous zirconium carbonate solution to the aqueous titanium lactate solution is 2:1 to 2.5:1.

[0017] By employing the above technical solution, the mass ratio of polyethylene glycol monomethyl ether to urea is limited to a specific range, ensuring sufficient high osmotic pressure and accurate hydrogen bond dissociation efficiency when water seepage occurs, while also ensuring that the coating does not lose its initial adhesion strength under normal drying conditions. The specific blending ratio of ammonium zirconium carbonate and titanium lactate creates a stepped distribution of bond energy in the coordination bonds constructed by the composite metal cations. This alternation of different bond energies enables the coating to dissipate stress under external forces and ensures the rate of secondary complexation reaction after fracture.

[0018] Secondly, the present invention provides a method for preparing a self-healing polymer emulsion cement waterproof coating, which adopts the following technical solution: A method for preparing a self-healing polymer emulsion cementitious waterproof coating includes the following steps: S1. Deionized water, polyethylene glycol monomethyl ether and urea are added to a reactor equipped with a frequency converter and stirred. Then, N,N-dimethylethanolamine is added dropwise to adjust the pH of the system to obtain a premixed solution. S2. Increase the stirring speed of the reactor, add styrene-acrylic emulsion to the premixed liquid, and continue stirring to homogenize; S3. Add the diluted aqueous solutions of ammonium zirconate carbonate and titanium lactate to the reactor and stir at a reduced speed. Then add polyether-modified polysiloxane defoamer and isothiazolinone preservative. Add the remaining N,N-dimethylethanolamine dropwise to adjust the final pH value of the system. After filtration through a filter screen, fill and seal to obtain the liquid material. S4. Quick-hardening sulfoaluminate cement, quartz sand, slow-release inorganic self-healing granules, silica fume, dry powder polycarboxylate superplasticizer and potassium sodium tartrate are sequentially added to the mixer for mixing, discharged and sealed to obtain powder. S5. Mix the liquid and powder according to the ratio, and stir evenly with an electric mixer to obtain a mixed slurry; S6. After the mixed slurry obtained in step S5 is allowed to stand and mature, it is applied to the base layer. After the application is completed, environmental curing is carried out to obtain a self-healing polymer emulsion cement waterproof coating.

[0019] By adopting the above technical solution, establishing an initial basic alkaline environment using a portion of N,N-dimethylethanolamine in the liquid preparation stage is a key prerequisite for stabilizing the emulsion particles. After introducing the polymer emulsion and adding the crosslinking agent, the remaining N,N-dimethylethanolamine is used to raise the alkalinity of the system to the final target value required for dormancy. The stepwise pH adjustment logic aims to avoid drastic fluctuations in pH caused by the instantaneous addition of the crosslinking agent, thereby maintaining the macroscopic stability of the entire emulsion dispersion system.

[0020] Preferably, in step S4, the preparation steps of the sustained-release inorganic self-healing particles are as follows: Take calcined diatomaceous earth powder and place it in a vacuum mixer, and degas it for 15 to 20 minutes under a vacuum of 0.08 to 0.095 MPa. Maintain a vacuum state, spray an aqueous solution of lithium silicate through an atomizing feed device, and continue stirring for 20 to 30 minutes after restoring normal pressure; The material was transferred to a forced-air drying oven and dried at a constant temperature of 60 to 70°C to obtain lithium silicate-loaded powder. The lithium silicate-loaded powder was transferred to a plow-type mixer with a heating jacket, heated and maintained at 75 to 85°C, and polyethylene glycol was added and sheared and mixed for 30 to 45 minutes. Stop heating and allow it to cool naturally to 30°C while stirring. Then, sieve the material to obtain the product.

[0021] By employing the above technical solution, air trapped inside the porous diatomaceous earth is removed under vacuum negative pressure, and atomized feeding is used to allow liquid lithium silicate to deeply impregnate the pore network of the powder. After removing moisture through constant-temperature drying and completing the internal solid-phase loading, the system keeps polyethylene glycol in a molten state at 75-85℃, and uses the forced mechanical shearing action of a mixer to uniformly coat it onto the surface of the inorganic powder particles. The physical isolation membrane formed after natural cooling and solidification ensures the physical integrity of the microcapsule structure in the subsequent hydration and stirring environment.

[0022] Preferably, in step S1, the stirring temperature is 20 to 35°C, the stirring speed is 200 to 350 revolutions per minute, and the stirring time is 10 to 15 minutes; in step S2, the stirring speed is increased to 400 to 650 revolutions per minute, and the continuous stirring time is 15 to 20 minutes.

[0023] By adopting the above technical solution, the clearly defined process parameters for the premixing and homogenization stages create conditions for the full miscibility of powdered and liquid small molecule components in the aqueous phase. The specifically enhanced high-speed operation enables rapid homogenization of emulsion particles while avoiding agglomeration induced by excessive mechanical shearing.

[0024] Preferably, in step S3, the stirring speed of the reactor is reduced to 150 to 220 revolutions per minute, and the stirring speed is maintained for 20 to 30 minutes.

[0025] By adopting the above technical solution, the operating speed of the equipment can be actively reduced during the droplet addition of the metal coordination crosslinking system, which can effectively reduce the physical impact of fluid shear force on the forming ion dormant system and ensure that each ion component inside the liquid has sufficient diffusion time to achieve a balanced state of charge distribution.

[0026] Preferably, in step S4, the mixing time of the mixer is 8 to 15 minutes; in step S6, the thickness of the wet film of the mixed slurry in a single application is controlled to be 0.5 to 1.0 mm, and the environmental curing conditions are: temperature 23±2℃ and relative humidity 50%±10%.

[0027] By adopting the above technical solution, not only is the operation cycle of powder dry mixing defined, but the specific conditions for final coating application are also standardized. The limited single wet film thickness, combined with specific ambient temperature and humidity, helps the moisture inside the coating evaporate outward at a uniform rate. This suppresses shrinkage stress defects caused by uneven thickness or drying rate, ensuring the physical density of the waterproof coating after curing.

[0028] This invention provides a self-healing polymer emulsion cement waterproof coating and its preparation method. It has the following beneficial effects: 1. This invention introduces polyethylene glycol monomethyl ether, urea, and a composite metal crosslinking agent into the liquid component, along with slow-release inorganic self-healing particles in the powder component. When the coating is damaged and leaks water, the polyethylene glycol monomethyl ether and urea dissociate the hydrogen bonds between polymer chains, causing macromolecular segments to slide into the cracks. Simultaneously, the free metal cations and side-chain carboxyl groups re-coordinate to establish a crosslinking network. The inorganic particles release silicate ions upon contact with water, which react with calcium ions in the cement matrix to form hydrated calcium silicate gel. The interface reconstruction of the organic coordination network and the rigid filling of the inorganic crystalline phase work together to effectively restore the density, impermeability, and secondary tensile strength of the cracked coating.

[0029] 2. This invention relies on the highly alkaline environment constructed by N,N-dimethylethanolamine in the formula to maintain ammonium zirconium carbonate and titanium lactate in an ion-complexed and constrained state during liquid storage. This microscopic chemical inhibition mechanism blocks the contact reaction pathway between highly active metal cations and free carboxyl groups on the side chains of styrene-acrylic emulsion molecules, avoiding irreversible premature cross-linking and viscosity surge of the liquid material under normal temperature or heating conditions, and ensuring the shelf life of the material after it leaves the factory.

[0030] 3. The polyethylene glycol hot-melt coating on the exterior of the inorganic self-healing particles of this invention acts as a physical barrier, preventing the free dissolution of lithium silicate during the initial mixing with water. This avoids premature setting of the slurry caused by instantaneous contact with free calcium ions in cement. The potassium sodium tartrate added to the powder preferentially complexes and consumes some of the free calcium ions during the initial hydration stage, preventing polyvalent cations from disrupting the electrostatic repulsion balance on the surface of the emulsion particles. The combination of these two factors eliminates the risk of sudden flocculation and clumping of the slurry, ensuring smooth coating operations. Attached Figure Description

[0031] Figure 1 This is a flowchart illustrating the preparation process of the present invention; Figure 2The figure shows the test results of the macroscopic microcrack self-healing performance of the coating of the present invention. (a) is a schematic diagram of the correlation between the complete water stop time and the anti-seepage pressure of each group, and (b) is a characteristic diagram of the change of tensile strength recovery rate after healing of each group. Figure 3 The figure shows the test results comparing the thermal storage stability of the liquid material and the application period of the slurry in this invention. (a) is a schematic diagram of the viscosity increase characteristics of the liquid material during accelerated thermal storage aging, and (b) is a schematic diagram of the decay of the application period of the mixed slurry. Figure 4 The figure shows the test results of the initial mechanical properties and ultimate interface self-healing rate of the coating of the present invention. (a) is a schematic diagram comparing the initial tensile strength and elongation at break of each group of coatings, and (b) is a schematic diagram of the tensile strength recovery rate after the coating fractures and heals by immersion in water. Detailed Implementation

[0032] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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 skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] The main raw materials and reagents used in the following examples and comparative examples have the following sources and specifications. Reagents not specifically mentioned are all commercially available analytical grade or higher grade products.

[0034] The CAS number for styrene-acrylic emulsion is 25085-34-1. It is an aqueous emulsion copolymerized from styrene and acrylate monomers.

[0035] The CAS number for polyethylene glycol monomethyl ether is 9004-74-4.

[0036] Aqueous solution of zirconium carbonate: an inorganic-organic composite crosslinking agent with a mass fraction of 15% to 25% based on zirconium oxide.

[0037] Aqueous solution of titanium lactate: Aqueous titanium chelate crosslinking agent, with a mass fraction of 6% to 15% based on titanium oxide.

[0038] The solid content of the lithium silicate aqueous solution is 20% to 25%.

[0039] The CAS number for polyethylene glycol is 25322-68-3.

[0040] The CAS number for potassium sodium tartrate is 6381-59-5.

[0041] Calcined diatomaceous earth is a porous siliceous powder obtained by high-temperature calcination of natural diatomaceous earth. Rapid-hardening sulfoaluminate cement, quartz sand, microsilica powder, dry powder polycarboxylate superplasticizer, polyether-modified polysiloxane defoamer, isothiazolinone preservative, N,N-dimethylethanolamine, and urea are all commercially available raw materials.

[0042] Preparation Example 1: This preparation example provides a method for preparing inorganic self-healing particles, including the following steps: Take 8 parts by weight of calcined diatomaceous earth powder and place it in a vacuum mixer. Degas it for 15 minutes under a vacuum of 0.08 MPa. Maintain a vacuum state and uniformly spray 4 parts by mass of lithium silicate aqueous solution into the diatomaceous earth through an atomizing feeding device that is connected to the vacuum system in a closed manner. After the spraying is completed, restore the atmospheric pressure and stir continuously at a speed of 100 revolutions per minute for 20 minutes. The material was transferred to a forced-air drying oven and dried at 60°C for 2 hours until the moisture content was less than or equal to 3%, thus obtaining lithium silicate-loaded powder. The lithium silicate-loaded powder was transferred to a plow-type mixer with a heating jacket, heated and maintained at 75°C, and 2.5 parts by weight of polyethylene glycol were added. The mixture was sheared and mixed at 300 rpm for 30 minutes. Stop heating and allow the mixture to cool naturally to 30°C while continuously stirring. Then, sieve it through an 80-mesh sieve to remove agglomerates. Take the sieved material to obtain the slow-release inorganic self-healing granules.

[0043] Preparation Example 2: This preparation example provides a method for preparing inorganic self-healing particles, including the following steps: Take 10 parts by weight of calcined diatomaceous earth powder and place it in a vacuum mixer, and degas it for 18 minutes under a vacuum of 0.09 MPa. Maintain a vacuum state and uniformly spray 5 parts by mass of lithium silicate aqueous solution into the diatomaceous earth through an atomizing feeding device that is in a closed connection with the vacuum system. After the spraying is completed, restore the atmospheric pressure and stir continuously at a speed of 120 revolutions per minute for 25 minutes. The material was transferred to a forced-air drying oven and dried at 65°C for 3 hours until the moisture content was less than or equal to 3%, thus obtaining lithium silicate-loaded powder. The lithium silicate-loaded powder was transferred to a plow-type mixer with a heating jacket, heated and maintained at 80°C, and 3.0 parts by weight of polyethylene glycol were added. The mixture was sheared and mixed at 400 rpm for 38 minutes. Stop heating and allow the mixture to cool naturally to 30°C while continuously stirring. Then, sieve it through an 80-mesh sieve to remove agglomerates. Take the sieved material to obtain the slow-release inorganic self-healing granules.

[0044] Preparation Example 3: This preparation example provides a method for preparing inorganic self-healing particles, including the following steps: Take 12 parts by weight of calcined diatomaceous earth powder and place it in a vacuum mixer, and degas it for 20 minutes under a vacuum of 0.095 MPa. Maintain a vacuum state and uniformly spray 6 parts by mass of lithium silicate aqueous solution into diatomaceous earth through an atomizing feeding device that is connected to the vacuum system in a closed manner. After the spraying is completed, restore the atmospheric pressure and stir continuously at a speed of 150 revolutions per minute for 30 minutes. The material was transferred to a forced-air drying oven and dried at 70°C for 4 hours until the moisture content was less than or equal to 3%, thus obtaining lithium silicate-loaded powder. The lithium silicate-loaded powder was transferred to a plow-type mixer with a heating jacket, heated and maintained at 85°C, and 3.5 parts by weight of polyethylene glycol were added. The mixture was sheared and mixed at 500 rpm for 45 minutes. Stop heating and allow the mixture to cool naturally to 30°C while continuously stirring. Then, sieve it through an 80-mesh sieve to remove agglomerates. Take the sieved material to obtain the slow-release inorganic self-healing granules.

[0045] See attached document Figure 1 Example 1: This embodiment provides a method for preparing a self-healing polymer cement waterproof coating, including the following steps: S1. Add 15 parts by mass of deionized water, 2 parts by mass of polyethylene glycol monomethyl ether and 0.3 parts by mass of urea to a reactor equipped with a variable frequency disperser, and stir at 200 rpm for 10 minutes at 20°C; add 0.4 parts by mass of N,N-dimethylethanolamine dropwise to adjust the pH of the system to 9.0.

[0046] S2. Increase the stirring speed to 400 rpm, add 40 parts by weight of styrene-acrylic emulsion to the reactor, and continue stirring for 15 minutes.

[0047] S3. Dilute 2.0 parts by mass of ammonium zirconium carbonate aqueous solution and 0.8 parts by mass of titanium lactate aqueous solution with deionized water by 3 times respectively; adjust the stirring speed of the reactor to 150 rpm, add the diluted ammonium zirconium carbonate aqueous solution and titanium lactate aqueous solution to the reactor, and stir at 150 rpm for 20 minutes; add 0.1 parts by mass of polyether modified polysiloxane defoamer and 0.05 parts by mass of isothiazolinone preservative; add N,N-dimethylethanolamine dropwise to adjust the pH value of the system to the range of 9.0 to 9.3, filter through a 100-mesh filter, fill and seal to obtain liquid material.

[0048] S4. 35 parts by weight of rapid-hardening sulfoaluminate cement, 30 parts by weight of quartz sand, 10 parts by weight of the slow-release inorganic self-healing granules prepared in Preparation Example 1, 4 parts by weight of silica fume, 0.1 parts by weight of dry powdered polycarboxylate superplasticizer, and 0.3 parts by weight of potassium sodium tartrate were sequentially added into a mixer and mixed for 8 minutes. When the coefficient of variation of the mixing uniformity was less than or equal to 5% after three-point sampling, the mixture was discharged, filled, and sealed to obtain powder.

[0049] S5. Mix the liquid and powder obtained above at a mass ratio of 1:1.2, and stir with an electric mixer at a speed of 300 rpm for 3 minutes to obtain a mixed slurry.

[0050] S6. After the mixed slurry obtained in step S5 is allowed to stand and mature for 3 minutes, it is applied to the base layer. The thickness of the wet film in a single application is controlled to be 0.5 mm. After the application is completed, the film is placed under the conditions of 23±2℃ and 50%±10% relative humidity for 7 consecutive days to obtain a self-healing polymer cement waterproof coating.

[0051] Example 1: This embodiment provides a method for preparing a self-healing polymer cement waterproof coating, including the following steps: S1. Add 20 parts by weight of deionized water, 3.5 parts by weight of polyethylene glycol monomethyl ether and 0.65 parts by weight of urea to a reactor equipped with a variable frequency disperser, and stir at 250 rpm for 12 minutes at 25°C; add 0.7 parts by weight of N,N-dimethylethanolamine dropwise to adjust the pH of the system to 9.2.

[0052] S2. Increase the stirring speed to 500 rpm, add 50 parts by mass of styrene-acrylic emulsion to the reactor, and continue stirring for 18 minutes.

[0053] S3. Dilute 3.0 parts by mass of ammonium zirconium carbonate aqueous solution and 1.4 parts by mass of titanium lactate aqueous solution with deionized water by 3 times respectively; adjust the stirring speed of the reactor to 180 rpm, add the diluted ammonium zirconium carbonate aqueous solution and titanium lactate aqueous solution to the reactor, and stir at 180 rpm for 25 minutes; add 0.2 parts by mass of polyether modified polysiloxane defoamer and 0.1 parts by mass of isothiazolinone preservative; add N,N-dimethylethanolamine dropwise to adjust the pH value of the system to the range of 9.2 to 9.5, filter through a 100-mesh filter, fill and seal to obtain liquid material.

[0054] S4. 40 parts by weight of rapid-hardening sulfoaluminate cement, 35 parts by weight of quartz sand, 15 parts by weight of the slow-release inorganic self-healing granules prepared in Preparation Example 2, 6 parts by weight of silica fume, 0.2 parts by weight of dry powdered polycarboxylate superplasticizer, and 0.55 parts by weight of potassium sodium tartrate were sequentially added into a mixer and mixed for 10 minutes. When the coefficient of variation of the mixing uniformity was less than or equal to 5% after three-point sampling, the mixture was discharged, filled, and sealed to obtain powder.

[0055] S5. Mix the liquid and powder obtained above at a mass ratio of 1:1.4, and stir with an electric mixer at a speed of 400 rpm for 4 minutes to obtain a mixed slurry.

[0056] S6. After the mixed slurry obtained in step S5 is allowed to stand and mature for 3 minutes, it is applied to the base layer. The thickness of the wet film in a single application is controlled to be 0.8 mm. After the application is completed, the film is placed under the conditions of 23±2℃ and 50%±10% relative humidity for 7 consecutive days to obtain a self-healing polymer cement waterproof coating.

[0057] Example 2: This embodiment provides a method for preparing a self-healing polymer cement waterproof coating, including the following steps: S1. Add 25 parts by weight of deionized water, 5 parts by weight of polyethylene glycol monomethyl ether and 1.0 part by weight of urea to a reactor equipped with a variable frequency disperser, and stir at 300 rpm for 15 minutes at 30°C; add 1.0 part by weight of N,N-dimethylethanolamine dropwise to adjust the pH of the system to 9.5.

[0058] S2. Increase the stirring speed to 600 rpm, add 60 parts by mass of styrene-acrylic emulsion to the reactor, and continue stirring for 20 minutes.

[0059] S3. Dilute 4.0 parts by mass of ammonium zirconium carbonate aqueous solution and 2.0 parts by mass of titanium lactate aqueous solution with deionized water by 3 times respectively; adjust the stirring speed of the reactor to 200 rpm, add the diluted ammonium zirconium carbonate aqueous solution and titanium lactate aqueous solution to the reactor, and stir at 200 rpm for 30 minutes; add 0.3 parts by mass of polyether modified polysiloxane defoamer and 0.15 parts by mass of isothiazolinone preservative; add N,N-dimethylethanolamine dropwise to adjust the pH value of the system to the range of 9.5 to 9.8, filter through a 100-mesh filter, fill and seal to obtain liquid material.

[0060] S4. 45 parts by weight of rapid-hardening sulfoaluminate cement, 40 parts by weight of quartz sand, 20 parts by weight of the slow-release inorganic self-healing granules prepared in Preparation Example 3, 8 parts by weight of silica fume, 0.3 parts by weight of dry powdered polycarboxylate superplasticizer, and 0.65 parts by weight of potassium sodium tartrate were sequentially added into a mixer and mixed for 12 minutes. When the coefficient of variation of the mixing uniformity was less than or equal to 5% after three-point sampling, the mixture was discharged, filled, and sealed to obtain powder.

[0061] S5. Mix the liquid and powder obtained above at a mass ratio of 1:1.6, and stir with an electric mixer at a speed of 500 rpm for 5 minutes to obtain a mixed slurry.

[0062] S6. After the mixed slurry obtained in step S5 has been left to stand and mature for 3 minutes, it is applied to the base layer. The thickness of the wet film in a single application is controlled to be 1.0 mm. After the application is completed, the film is placed under the conditions of 23±2℃ and 50%±10% relative humidity for 7 consecutive days to obtain a self-healing polymer cement waterproof coating.

[0063] Example 3: This embodiment provides a method for preparing a self-healing polymer cement waterproof coating, including the following steps: S1. Add 20 parts by weight of deionized water, 3.5 parts by weight of polyethylene glycol monomethyl ether and 0.65 parts by weight of urea to a reactor equipped with a variable frequency disperser, and stir at 350 rpm for 15 minutes at 35°C; add 0.7 parts by weight of N,N-dimethylethanolamine dropwise to adjust the pH of the system to 9.2.

[0064] S2. Increase the stirring speed to 650 rpm, add 50 parts by weight of styrene-acrylic emulsion to the reactor, and continue stirring for 20 minutes.

[0065] S3. Dilute 3.0 parts by mass of ammonium zirconium carbonate aqueous solution and 1.4 parts by mass of titanium lactate aqueous solution with deionized water by 3 times respectively; adjust the stirring speed of the reactor to 220 rpm, add the diluted ammonium zirconium carbonate aqueous solution and titanium lactate aqueous solution to the reactor, and stir at 220 rpm for 25 minutes; add 0.2 parts by mass of polyether modified polysiloxane defoamer and 0.1 parts by mass of isothiazolinone preservative; add N,N-dimethylethanolamine dropwise to adjust the pH value of the system to the range of 9.2 to 9.5, filter through a 100-mesh filter, fill and seal to obtain liquid material.

[0066] S4. 40 parts by weight of rapid-hardening sulfoaluminate cement, 35 parts by weight of quartz sand, 15 parts by weight of the slow-release inorganic self-healing granules prepared in Preparation Example 2, 6 parts by weight of silica fume, 0.2 parts by weight of dry powdered polycarboxylate superplasticizer, and 0.55 parts by weight of potassium sodium tartrate were sequentially added into a mixer and mixed for 15 minutes. When the coefficient of variation of the mixing uniformity was less than or equal to 5% after three-point sampling, the mixture was discharged, filled, and sealed to obtain powder.

[0067] S5. Mix the liquid and powder obtained above at a mass ratio of 1:1.4, and stir with an electric mixer at a speed of 500 rpm for 5 minutes to obtain a mixed slurry.

[0068] S6. After the mixed slurry obtained in step S5 is allowed to stand and mature for 3 minutes, it is applied to the base layer. The thickness of the wet film in a single application is controlled to be 0.8 mm. After the application is completed, the film is placed under the conditions of 23±2℃ and 50%±10% relative humidity for 7 consecutive days to obtain a self-healing polymer cement waterproof coating.

[0069] Comparative Example 1: Compared with Example 2, the difference is that the inorganic self-healing particles used in the powder were not coated with polyethylene glycol during the preparation process, and calcined diatomaceous earth powder loaded with lithium silicate was used directly. All other aspects are the same.

[0070] Comparative Example 2: The difference from Example 2 is that N,N-dimethylethanolamine was not added dropwise during the preparation of the liquid to adjust the pH value; otherwise, they are the same.

[0071] Comparative Example 3: Compared with Example 2, the difference is that potassium sodium tartrate was not added to the powder, and it was replaced with quartz sand in equal mass; otherwise, they are the same.

[0072] Comparative Example 4: Compared with Example 2, the difference is that polyethylene glycol monomethyl ether and urea were not added to the liquid, and were replaced with deionized water in equal mass; otherwise, they are the same.

[0073] Comparative Example 5: Compared with Example 2, the difference is that: no slow-release inorganic self-healing particles were added to the powder, and they were replaced by particles of pure calcined diatomaceous earth coated with polyethylene glycol without lithium silicate loading. All other aspects are the same.

[0074] Comparative Example 6: Compared with Example 2, the difference is that no aqueous solution of ammonium zirconium carbonate and aqueous solution of titanium lactate were added to the liquid, and deionized water was replaced by an equal mass. All other aspects are the same.

[0075] Test Example 1: Test Description: This experiment compares the performance differences of Examples 1 to 4 of the present invention with those of Comparative Examples 4 to 6 in the fracture rehealing process, and examines the anti-permeability healing performance and the degree of mechanical strength recovery of the coating with microcracks under a set water pressure.

[0076] Test steps: The self-healing polymer cement waterproof coatings prepared in Examples 1 to 4 and Comparative Examples 4 to 6 were selected as test objects. Each group of coatings was cut into standard square specimens with a length and width of 150 mm using a cutter. A linear micro-crack penetrating the thickness of the coating was horizontally cut in the center area of ​​the square specimen using a fine scalpel. The initial crack width of each group of specimens was controlled to be about 0.30 mm by cross-positioning with vernier calipers and thickness gauges.

[0077] Square specimens with initial microcracks were fixed onto the test mold of a building mortar permeability tester, with the back of the specimen connected to a pressure-stabilized water system. The tester was started and a constant low water pressure of 0.1 MPa was applied. The time taken for the cracks to completely stop leaking under this water pressure was recorded as the time to complete cessation of water seepage. After no water droplets seeped from the specimen surface and this was maintained for 24 hours, the system water pressure was gradually increased in increments of 0.05 MPa. Each pressure increase was followed by a stabilization observation for 1 hour until the specimen experienced a rupture failure point where water again seeped through the cracks. The previous stabilization pressure value was recorded as the highest permeability resistance pressure after healing.

[0078] For dumbbell-shaped specimens, the specimens were completely severed at the middle gauge length using a blade. The two fragments were then joined tightly together and placed flat in a shallow trough lined with a PTFE film. Deionized water at 20°C was poured into the trough until it just covered the specimen surface, and the specimens were left to cure in the water for 7 days. After curing, the specimens were removed and the surface moisture was blotted dry with filter paper. They were then clamped in a universal tensile testing machine and subjected to a second tensile test at a tensile speed of 200 mm / min. The obtained fracture load was converted into tensile strength, and divided by the nominal tensile strength of the undamaged original specimens in the same group to calculate the tensile strength recovery rate after healing.

[0079] The test data is shown in Table 1: Table 1: Test data on the self-healing performance of macroscopic and micro-cracks in the coating

[0080] See attached document Figure 2According to the data in Table 1, the coating specimens prepared in Examples 1 to 4, under a set constant low water pressure, were able to effectively compact internal pores and microcracks within a range of 31.8 to 38.5 hours, blocking water penetration. The healed system could withstand secondary anti-permeability pressure above 0.28 MPa, and the tensile strength recovery rate after fracture repair remained stable at over 80%. Example 2 exhibited relatively optimal comprehensive performance among various test indicators, indicating that the inorganic active material and polymer network achieved the best synergistic effect under this ratio.

[0081] In Comparative Example 4, due to the removal of polyethylene glycol monomethyl ether and urea, the infiltrated water was unable to construct locally high-concentration water-retaining micro-regions at the fracture interface to break the existing hydrogen bonds between polymer chain segments. The lack of this plasticizing unlocking mechanism resulted in the polymer molecular chains being solidified and bound, making it difficult for them to slide and migrate into the crack space. Macroscopically, this manifested as the specimen remaining in a leaking state throughout more than 120 hours of continuous hydrostatic testing, with complete failure of the interfacial physical adhesion and a tensile strength recovery rate of only 12.4%.

[0082] Comparative Example 5 used pure diatomaceous earth particles without lithium silicate loading in the powder. Although the polymer phase exhibited certain swelling and chain segment creep behavior, which allowed the specimen to barely achieve penetration slowdown after nearly 100 hours, the structure of the healed area was fragile due to the lack of a hydrated calcium silicate gel network inside the crack for physical support and hard blocking.

[0083] Comparative Example 6 did not introduce a composite metal crosslinking system with dual coordination function, making it difficult to construct a coordination network with dynamic reversible properties in the main framework of the coating film. This structural defect caused the fracture surface to lose the chemical driving force for the reassociation of metal cations and side-chain anions in the hydration environment. Since the residual strength is maintained solely by the physical entanglement of polymer chain segments, both its impermeability density and interface healing rate declined.

[0084] Test Example 2: Test Description: This experiment observes the consistency change of the liquid system under accelerated aging conditions and analyzes the differences between the examples and comparative examples in maintaining system stability by combining the decline history of the slurry fluidity after powder-liquid mixing.

[0085] Test steps: The finished materials prepared in Examples 1 to 4 and Comparative Examples 1 to 3 were selected as the main test objects. Liquid samples from each group were collected, and their initial viscosity values ​​were measured using a rotational viscometer at room temperature. Subsequently, the sealed packages of the test liquids were transferred to an electric thermostatic incubator set at 50°C for 14 days of continuous accelerated thermal storage aging. After the aging cycle, all samples were removed and allowed to cool to 25°C in a standard laboratory. The absolute viscosity of the system was measured again, and the appearance of the phase phase (whether stratification or agglomeration occurred) was recorded simultaneously. The thermal storage viscosity growth rate was calculated based on the viscosity values ​​obtained before and after aging.

[0086] Accurately weigh the liquid and powder materials according to the preset liquid-solid ratio range of each embodiment and corresponding proportion, and mix them evenly using a dispersing mixer at a specified speed to prepare a test slurry. Quickly pour the freshly mixed slurry into a standard truncated cone mold for initial flowability testing, and record the average diameter of the slurry after it has freely spread and stabilized. After the initial test, collect the remaining slurry and store it in a sealed container. Resample every 30 minutes and repeat the above spreading test process until obvious flocculation and agglomeration are observed inside the slurry or the measured flowability value decreases to less than 50% of the initial value. Record the time span from the start of liquid-powder contact mixing to the flowability reaching the above-mentioned failure threshold as the applicable construction period for the corresponding group of materials. If, during this test, a certain proportion has already undergone severe solidification during the pretreatment stage and cannot be mixed and homogenized, its relevant flowability performance indicators are directly recorded as the failure threshold parameters.

[0087] The test data is shown in Table 2: Table 2: Comparative Test Data of Storage Aging and Construction Applicability

[0088] See attached document Figure 3 According to the data in Table 2, the viscosity increase of the liquid component in the examples was controlled within 6% after undergoing rigorous high-temperature aging cycles. The initial free flowability of the mixed slurry was at a high baseline, and the effective construction time span was maintained at over 140 minutes. These measured indicators verified the engineering reliability and component compatibility of the proposed formulation system under extreme environmental and actual construction conditions.

[0089] Comparative Example 2, by directly removing the volatile organic amine responsible for pH regulation during the liquid synthesis stage, disrupted the highly alkaline dormant environment required for system stability. The dissolved ammonium zirconium carbonate and titanium lactate irreversibly released their existing ionic complexation constraints at room temperature and under subsequent thermal activation, resulting in a large release of highly reactive metal cations that rapidly and violently crosslinked with the free carboxyl groups in the emulsion's main chain region. This uncontrolled, abnormal polymerization at the microscopic level directly led to severe phase separation and large-area network agglomeration in the macroscopic liquid, causing an exponential increase in internal motion resistance and rendering powder coating operations unfeasible.

[0090] Comparative Example 1 omitted the physical thermal coating process of polyethylene glycol onto the outer porous diatomaceous earth structure during the inorganic phase processing. This caused a large amount of the originally latent highly active lithium silicate solution to dissolve and release during the early stages of mechanical stirring in water. The high concentration of silicate ions in the solution collided and came into contact with the calcium ions stripped from the initial hydration reaction of cement, producing a large amount of insoluble crystal precipitates. This sudden side reaction, uncontrolled by the time gradient, induced irreversible early-strength curing of the mixture in about 21 minutes. Comparative Example 3, lacking the addition of potassium sodium tartrate, lacked a preferential and mild complexation intervention mechanism for trace amounts of free calcium ions. The various inorganic cations released by the dissolution of cement particles disrupted the originally fragile electrostatic repulsion balance on the surface of the styrene-acrylic emulsion, causing local demulsification and flocculation of polymer particles, thereby reducing the spreading and deformation ability and service life of the reference slurry.

[0091] Test Example 3: Test Description: This experiment investigates the specific effects of core components such as the crosslinking system, hydrogen bond disruptor, and inorganic active repair particles on the material's elasticity and fracture surface bonding strength by measuring the tensile strength and elongation of the original coating and comparing them with the same group of specimens after complete cutting and water immersion repair.

[0092] Test steps: Samples from Examples 1 to 4 and Comparative Examples 4 to 6, cured under standard curing conditions, were used as test subjects. Each group of coatings was cut into standard dumbbell-shaped specimens using a cutter. Multiple points within the gauge length were measured using calipers and a thickness gauge, and the average cross-sectional area was recorded. The specimens were clamped in the upper and lower fixtures of a universal tensile testing machine, and subjected to unidirectional axial tensile testing at a specified tensile rate under normal temperature conditions until the specimen completely fractured. The maximum breaking load and corresponding elongation at break were recorded. The initial tensile strength was calculated by the ratio of the maximum load to the initial cross-sectional area.

[0093] Collect fresh dumbbell-shaped specimens unused in the first tensile test. Using a single-edged blade, completely cut them in half perpendicular to the direction of force at the center of the gauge length. Place the two cut surfaces tightly together and horizontally at the bottom of a constant-temperature water bath lined with a PTFE release liner. Slowly pour in deionized water at a constant temperature of 20°C, ensuring the liquid level just covers the specimen surface. Maintain this submerged state for 7 consecutive days to fully activate the physicochemical healing reaction within the system.

[0094] After the curing period, the specimens were removed from the water tank, wiped with absorbent filter paper to remove any remaining free moisture, and allowed to dry at room temperature for 2 hours. The repaired specimens were then reinstalled on a universal tensile testing machine and subjected to tensile testing again until fracture using the same operating parameters as the initial test. The corresponding secondary maximum load was extracted and converted into the secondary tensile strength after healing. The obtained secondary tensile strength was divided by the initial tensile strength of the original specimens in the same group to obtain the tensile strength recovery rate of each group of coatings.

[0095] The test data is shown in Table 3: Table 3: Comparison Test Data of Initial Mechanical Properties and Self-Healing Rate of Coating Film

[0096] See attached document Figure 4 According to the data in Table 3, the high-density dynamic coordination network constructed within the example group effectively absorbed and dispersed the applied tensile stress, giving the coating a limiting elongation of over 240%. Under the stimulation of the water immersion environment, the fractured specimen activated the small molecule plasticization and release mechanism and the macromolecular chain segment unlocking mechanism. With the dense filling of the inorganic phase, the repair interface regenerated a cross-scale physical anchoring and chemical association network, and finally recorded more than 80% of the secondary tensile strength recovery data.

[0097] In Comparative Example 6, the removal of ammonium zirconium carbonate and titanium lactate made it difficult to form a special coordination framework with both strong ionic bonds and reversible hydrogen bonds within the coating. The polymer matrix could only maintain its morphology through weak intermolecular van der Waals forces and physical entanglement. This loose microstructure directly led to the specimen exhibiting macroscopic brittleness and deterioration, with the elongation at break sharply reduced to about 74%. During the water immersion repair stage, the lack of a driving force for the reassociation of free metal cations and side-chain carboxyl groups made it difficult to achieve high-strength interfacial chemical bonding on the fracture surface.

[0098] Comparative Example 4, after removing the polyethylene glycol monomethyl ether and urea composite system, lost its specific dissociation ability against the deadlocked hydrogen bonds within the polymer chain. Moisture penetration into the fracture surface failed to induce a temporary decrease in the local glass transition temperature. Macromolecular segments were rigidly fixed at the fracture edge by the rigid network, preventing cross-fracture sliding and fusion. The macroscopic tensile strength recovery rate plummeted to the ineffective range of 13%. Comparative Example 5, using pure diatomaceous earth without lithium silicate loading, severed the chemical pathway for the formation of hydrated calcium silicate gel. Although the creep behavior of the organic phase contributed to the physical adhesion of the interface to some extent, the lack of rigid thermodynamic welding support provided by the interweaving of insoluble inorganic crystalline phases meant that the fracture surface, relying purely on soft polymer bonding, was easily torn under secondary mechanical tension.

[0099] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A self-healing polymer emulsion cement waterproof coating, characterized in that, Includes liquid and powder materials in isolated packaging, wherein the mass ratio of liquid to powder is 1:1.2-1.6; The liquid is composed of the following components in parts by weight: 15-25 parts deionized water, 2-5 parts polyethylene glycol monomethyl ether, 0.3-1.0 parts urea, 0.4-1.7 parts N,N-dimethylethanolamine, 40-60 parts styrene-acrylic emulsion, 2.0-4.0 parts ammonium zirconium carbonate aqueous solution, 0.8-2.0 parts titanium lactate aqueous solution, 0.1-0.3 parts polyether-modified polysiloxane defoamer, and 0.05-0.15 parts isothiazolinone preservative; The powder is made from the following components in parts by weight: 35-45 parts of rapid-hardening sulfoaluminate cement, 30-40 parts of quartz sand, 10-20 parts of slow-release inorganic self-healing particles, 4-8 parts of microsilica powder, 0.1-0.3 parts of dry powder polycarboxylate superplasticizer, and 0.3-0.65 parts of potassium sodium tartrate.

2. The self-healing polymer emulsion cement waterproof coating according to claim 1, characterized in that, The slow-release inorganic self-healing particles are made from the following components in parts by weight: 8-12 parts calcined diatomaceous earth powder, 4-6 parts lithium silicate aqueous solution, and 2.5-3.5 parts polyethylene glycol.

3. The self-healing polymer emulsion cement waterproof coating according to claim 2, characterized in that, In the slow-release inorganic self-healing particles, lithium silicate is loaded inside the porous structure of the calcined diatomaceous earth, and polyethylene glycol forms a physical isolation film covering the surface of the calcined diatomaceous earth through hot-melt coating.

4. The self-healing polymer emulsion cement waterproof coating according to claim 1, characterized in that, The aqueous solutions of zirconium carbonate and titanium lactate in the liquid are both diluted with deionized water by a factor of 3.

5. The self-healing polymer emulsion cement waterproof coating according to claim 1, characterized in that, In the liquid, the mass ratio of polyethylene glycol monomethyl ether to urea is 5:1-20:3; the mass ratio of the aqueous zirconium carbonate solution to the aqueous titanium lactate solution is 2:1-2.5:

1.

6. A method for preparing a self-healing polymer emulsion cement waterproof coating, used to prepare the self-healing polymer emulsion cement waterproof coating according to any one of claims 1-4, characterized in that, Includes the following steps: S1. Deionized water, polyethylene glycol monomethyl ether and urea are added to a reactor equipped with a frequency converter and stirred. Then, N,N-dimethylethanolamine is added dropwise to adjust the pH of the system to obtain a premixed solution. S2. Increase the stirring speed of the reactor, add styrene-acrylic emulsion to the premixed liquid, and continue stirring to homogenize; S3. Add the diluted aqueous solutions of ammonium zirconate carbonate and titanium lactate to the reactor and stir at a reduced speed. Then add polyether-modified polysiloxane defoamer and isothiazolinone preservative. Add the remaining N,N-dimethylethanolamine dropwise to adjust the final pH value of the system. After filtration through a filter screen, fill and seal to obtain the liquid material. S4. Quick-hardening sulfoaluminate cement, quartz sand, slow-release inorganic self-healing granules, silica fume, dry powder polycarboxylate superplasticizer and potassium sodium tartrate are sequentially added to the mixer for mixing, discharged and sealed to obtain powder. S5. Mix the liquid and powder according to the ratio, and stir evenly with an electric mixer to obtain a mixed slurry; S6. After the mixed slurry obtained in step S5 is allowed to stand and mature, it is applied to the base layer. After the application is completed, environmental curing is carried out to obtain a self-healing polymer emulsion cement waterproof coating.

7. The preparation method of the self-healing polymer emulsion cement waterproof coating according to claim 6, characterized in that, In step S4, the preparation steps of the sustained-release inorganic self-healing particles are as follows: Take calcined diatomaceous earth powder and place it in a vacuum mixer, and degas it for 15-20 minutes under a vacuum of 0.08-0.095 MPa. Maintain a vacuum state, spray lithium silicate aqueous solution into the atomizing feed device, and continue stirring for 20-30 minutes after restoring normal pressure; The material was transferred to a forced-air drying oven and dried at a constant temperature of 60-70℃ to obtain lithium silicate-loaded powder. The lithium silicate-loaded powder was transferred to a plow-type mixer with a heating jacket, heated and maintained at 75-85°C, and polyethylene glycol was added and sheared and mixed for 30-45 minutes. Stop heating and allow it to cool naturally to 30°C while stirring. Then, sieve the material to obtain the product.

8. The preparation method of the self-healing polymer emulsion cement waterproof coating according to claim 6, characterized in that, In step S1, the stirring temperature is 20-35℃, the stirring speed is 200-350 revolutions per minute, and the stirring time is 10-15 minutes; in step S2, the stirring speed is increased to 400-650 revolutions per minute, and the stirring time is 15-20 minutes.

9. The preparation method of the self-healing polymer emulsion cement waterproof coating according to claim 6, characterized in that, In step S3, the stirring speed of the reactor is reduced to 150-220 revolutions per minute, and the stirring speed is maintained for 20-30 minutes.

10. The preparation method of the self-healing polymer emulsion cement waterproof coating according to claim 6, characterized in that, In step S4, the mixing time of the mixer is 8-15 minutes; in step S6, the thickness of the wet film of the mixed slurry in a single coat is controlled to be 0.5-1.0 mm, and the environmental curing conditions are: temperature 23±2℃ and relative humidity 50%±10%.

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