Invisible waterproof agent based on molybdenum disulfide / titanium dioxide synergistic photocatalysis and preparation method thereof

Abstract

The invention discloses an invisible waterproof agent based on molybdenum disulfide / titanium dioxide synergistic photocatalysis and a preparation method. The waterproof agent comprises a photocatalytic composite master batch and a water-based main system, wherein the photocatalytic composite master batch comprises the following components: a mixed solvent, petroleum aromatic resin, molybdenum disulfide nanosheets, nano titanium dioxide, polyethylene wax micro powder, phenyl modified silicone oil and a macromolecular block compatilizer. According to the method disclosed by the invention, the molybdenum disulfide and the titanium dioxide are embedded with each other to form the heterojunction by accurately controlling the mass ratio of the molybdenum disulfide and the titanium dioxide and a heating ultrasonic and heat preservation curing process. The multifunctional bridging and catalytic synergistic effect of the molybdenum disulfide nanosheets not only realizes the stable compatibility of the hydrophobic component and the aqueous emulsion, but also creatively introduces an efficient visible light catalytic self-cleaning function for the waterproof coating, and solves the problem that the traditional waterproof agent is passive and single in function.

Description

Technical Field

[0001] This invention belongs to the field of waterproof coating technology, specifically relating to an invisible waterproofing agent based on the synergistic photocatalysis of molybdenum disulfide / titanium dioxide and its preparation method. Background Technology

[0002] Building exterior walls, constantly exposed to rainwater, ultraviolet radiation, and pollutants, are prone to problems such as water seepage, cracking, weathering, algae growth, and dirt accumulation. These issues not only affect aesthetics and hygiene but also accelerate material aging and shorten the building's lifespan. Traditional exterior waterproofing materials are primarily based on silicone and acrylic resins, which, while possessing some hydrophobicity and weather resistance, offer only passive and limited functionality, exhibiting significant shortcomings in long-term self-cleaning, resistance to biological contamination, and intelligent response. Especially for buildings that prioritize historical preservation or modern aesthetics, providing active protective capabilities to the coating without altering its appearance (i.e., "invisibility") remains a key technological challenge.

[0003] Currently, research on improving coating functionality mainly follows two directions: one is to construct superhydrophobic surfaces and utilize micro-nano rough structures to achieve the "lotus effect" for water repellency and anti-fouling; the other is to introduce photocatalytic materials (such as nano-titanium dioxide) to utilize their photo-oxidation capabilities to degrade surface organic matter and achieve self-cleaning. However, both of these approaches have limitations when applied alone: ​​the micro-nano structures of simple superhydrophobic structures are easily damaged in complex outdoor environments (such as dust accumulation and mechanical wear), leading to rapid functional failure, and high roughness often sacrifices the transparency of the coating; while nano-titanium dioxide used alone has limited catalytic activity under visible light due to its high photogenerated electron-hole recombination rate and low quantum efficiency, and its dispersibility and stability in coatings are also challenges.

[0004] In recent years, two-dimensional nanomaterials (such as graphene oxide) have been explored as reinforcing phases and barrier layers in coatings to improve overall performance due to their unique layered structure and tunable surface properties. However, these materials primarily provide physical barriers and passive protection, with limited ability to endow coatings with active intelligent properties such as environmental responsiveness and energy conversion.

[0005] Therefore, developing a stable and environmentally friendly coating system that organically combines highly efficient photocatalytic self-cleaning capabilities with excellent stealth and waterproof performance has significant practical application value. Research has found that molybdenum disulfide, as a typical two-dimensional transition metal sulfide, not only possesses a graphene-like layered structure that can serve as a physical barrier layer, but its unique band structure can also form a heterojunction with titanium dioxide, effectively promoting the separation of photogenerated carriers and significantly improving the catalytic efficiency of titanium dioxide in the visible light region. This synergistic effect provides a novel material basis and technological path for constructing next-generation "active" intelligent protective coatings. Summary of the Invention

[0006] The purpose of this invention is to provide an invisible waterproofing agent based on the synergistic photocatalysis of molybdenum disulfide and titanium dioxide, and its preparation method. This is a smart invisible waterproofing agent modified by the synergistic modification of molybdenum disulfide and titanium dioxide, characterized by an invisible and transparent coating, excellent waterproofing, abrasion resistance, durability, and visible light-responsive self-cleaning function. More specifically, this invention significantly improves the photocatalytic self-cleaning efficiency and stability of the coating by precisely controlling the mass ratio of molybdenum disulfide and titanium dioxide and the composite process, thereby constructing a highly efficient heterogeneous structure at their interface. To this end, this invention also provides a method for preparing this waterproofing agent.

[0007] The technical solution adopted by this invention to solve its technical problem is as follows: This invention provides an invisible waterproofing agent based on the synergistic photocatalysis of molybdenum disulfide / titanium dioxide, which includes a photocatalytic composite masterbatch and an aqueous main system.

[0008] The photocatalytic composite masterbatch components are as follows: 18-22 parts mixed solvent, 4-6 parts petroleum aromatic resin, 0.2-0.6 parts molybdenum disulfide nanosheets, 0.1-0.3 parts nano titanium dioxide, 1-2 parts polyethylene wax powder, 1.5-2.5 parts phenyl modified silicone oil, and 0.2-0.4 parts polymer block compatibilizer; The water-based main system components are in the following mass proportions: 68-75 parts silicone-acrylic emulsion, 1-2 parts polyurethane hardener, 2-3 parts film-forming aid, 0.5-1 part wetting and dispersing agent, 0.4-0.8 parts defoamer, 0.2-0.4 parts thickener, and 4-8 parts deionized water.

[0009] Another objective of this invention is to provide a method for preparing an invisible waterproofing agent based on the synergistic photocatalysis of molybdenum disulfide and titanium dioxide, the specific steps of which are as follows: Step 1: Molybdenum disulfide nanosheets and nano-titanium dioxide were added to a mixed solvent and sheared at high speed (800-1200 rpm) for 20-40 minutes at room temperature to obtain a preliminary dispersion. The dispersion was then heated to 40-60°C and ultrasonically treated at 200-400W for 30-60 minutes to obtain a uniform and stable molybdenum disulfide / titanium dioxide composite dispersion. This process utilizes the high-temperature, high-pressure microenvironment generated by ultrasonic cavitation and the thermal energy provided by the system to synergistically drive the physical embedding and chemical anchoring of nano-titanium dioxide at the edges and surface defect sites of the molybdenum disulfide nanosheets, thus initially constructing a heterojunction interface.

[0010] Then, the composite dispersion is continuously heated to 75-85°C at a speed of 300-600 rpm for 1-2 hours. Petroleum aromatic resin is slowly added and the mixture is continuously heated and stirred for 15-45 minutes to allow the resin molecules to fully combine with the hydrophobic surface of molybdenum disulfide. At the same time, the resin can also penetrate and adhere to the formed heterostructure to obtain a uniform composite functional resin liquid. Step 2: Heat the composite functional resin liquid obtained in Step 1 to 80~90℃, add polyethylene wax micro powder under high-speed shearing at 5000~6000rpm, and stir for 25~35 minutes while maintaining the temperature and shear force to completely melt and disperse the polyethylene wax. Step 3: The system obtained in Step 2 is cooled to 55-65℃ at a rate of 1-2℃ / min. Phenyl modified silicone oil and polymer block compatibilizer are added sequentially under continuous high-speed shearing. After the addition is completed, shearing is continued for 30-40 minutes to obtain photocatalytic composite masterbatch. Step 4: Place the silicone-acrylic emulsion in a reaction vessel, and add the film-forming aid, wetting and dispersing agent and defoamer in sequence under low-speed stirring. Stir for 10-15 minutes to obtain a dispersed emulsion. Step 5: Under shearing at 3000~4000rpm, slowly add the multifunctional composite masterbatch obtained in step 3 to a portion of the dispersion emulsion to form a uniform pre-emulsion slurry. Step 6: While stirring at a low speed of 400~600 rpm, slowly add the pre-emulsified slurry to the remaining dispersion emulsion, then add the polyurethane hardener, and then stir at a medium speed of 800~1200 rpm for 15~25 minutes to ensure uniform mixing; Step 7: Predissolve the thickener in some deionized water and add it to the system, then add the remaining deionized water and stir continuously at 100-300 rpm for 30-45 minutes. Step 8: Let the obtained product stand at room temperature for 3-5 hours to mature, then filter it through a 5-10μm precision filter to obtain the finished invisible waterproofing agent.

[0011] In step 1 of this invention, the molybdenum disulfide nanosheets have a few-layer structure with 1 to 5 layers, a lateral dimension of 0.2 to 1.5 μm, and a purity of ≥99%.

[0012] In step 1 of this invention, the nano-titanium dioxide is anatase type with a particle size of 10~50nm. The preferred mass ratio of the molybdenum disulfide nanosheets to the nano-titanium dioxide is (2:1) to (3:1).

[0013] In step 3 of this invention, the phenyl-modified silicone oil has a phenyl content of 15% to 35% and a viscosity of 500 to 2000 mPa·s.

[0014] In step 3 of this invention, the polymeric block compatibilizer is one or a combination of two of ethylene oxide-propylene oxide block copolymer and polyether-modified polysiloxane.

[0015] In step 4 of this invention, the solid content of the silicone-acrylic emulsion is 40% to 60%, and the glass transition temperature is 15 to 25°C.

[0016] In step 5 of this invention, the amount of the partially dispersed emulsion used for pre-emulsification is 10% to 20% of the total amount of the dispersed emulsion.

[0017] In step 8 of this invention, the curing environment temperature is 20~30℃ and the relative humidity is 40%~60%.

[0018] This invention presents a molybdenum disulfide / titanium dioxide synergistic modified smart invisible waterproofing agent with excellent waterproofing performance, abrasion resistance, invisibility, and visible light-driven self-cleaning function. After application, the waterproofing agent forms a colorless and transparent coating on the substrate surface, penetrating concrete substrates to a depth of 3–7 mm, with a water contact angle ≥120°, and abrasion resistance (750g / 500r) weight loss ≤0.02g. After a xenon lamp aging test (simulated sunlight, 500h), the coating exhibits a degradation rate of ≥80% for liquid methylene blue, demonstrating durable self-cleaning ability.

[0019] Through experimentation, the inventors discovered that by combining a molybdenum disulfide / titanium dioxide composite, polyethylene wax, phenyl-modified silicone oil, and petroleum aromatic resin using a specific process sequence, they not only solved the multi-component compatibility problem but also creatively constructed a tight interfacial contact (heterojunction) between molybdenum disulfide and titanium dioxide. Molybdenum disulfide nanosheets play multiple key roles in the system: their hydrophobic basal surface tightly binds to organic components such as petroleum aromatic resin, while the active sites at their edges help to stably disperse and anchor nano-titanium dioxide in the aqueous phase. More importantly, as a highly efficient co-catalyst, the heterostructure formed by molybdenum disulfide and titanium dioxide significantly promotes the separation of photogenerated electron-hole pairs, extending the photoresponse range of titanium dioxide into the visible light region, thereby endowing the coating with strong and durable self-cleaning capabilities. The polyethylene wax, through melt dispersion and programmed cooling processes, exists stably in the coating in microcrystalline form, providing wear resistance while avoiding whitening caused by excessive crystallization.

[0020] Compared with the prior art, the beneficial effects of the present invention are mainly reflected in: (1) Through the multifunctional bridging and catalytic synergistic effect of molybdenum disulfide nanosheets, not only is stable compatibility between hydrophobic components and aqueous emulsion achieved, but also a highly efficient visible light catalytic self-cleaning function is introduced into the waterproof coating, solving the problem of passive and single function of traditional waterproofing agents. (2) Through heating, ultrasonication, and heat preservation curing processes, molybdenum disulfide and titanium dioxide are intercalated to form a heterojunction. Compared with the use of nano-titanium dioxide alone, this heterojunction has high catalytic efficiency and good stability, enabling the coating to continuously decompose surface organic pollutants under natural light, thus achieving "active" protection; (3) The excellent solid lubrication properties of molybdenum disulfide itself further enhance the wear resistance of the coating and produce a synergistic reinforcing effect with polyethylene wax microcrystals; (4) A stepwise composite process was adopted to first construct a molybdenum disulfide / titanium dioxide-aromatic resin composite framework, which ensured the uniform dispersion and interface stability of functional nanomaterials in the system, so that the functions of each component could be fully utilized. (5) The pre-emulsification process achieves a stable combination of high-content oil phase masterbatch and aqueous phase emulsion, avoiding phase separation and demulsification. (6) The high refractive index of phenyl modified silicone oil is well matched with the system, providing superhydrophobicity while ensuring the invisibility of the coating; (7) The product integrates waterproof, wear-resistant, invisible and self-cleaning properties, and provides intelligent and long-lasting protection for building exterior walls without changing their appearance. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the method of the present invention. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0023] Example 1 The formulation of the intelligent invisible waterproofing agent of this invention is as follows: Photocatalytic composite masterbatch formulation: 20 parts mixed solvent (10 parts xylene, 10 parts D-limonene), 5 parts petroleum aromatic resin, 0.4 parts molybdenum disulfide nanosheets, 0.2 parts nano titanium dioxide (anatase type), 1.5 parts polyethylene wax powder, 2 parts phenyl modified silicone oil, and 0.3 parts polymer block compatibilizer.

[0024] Water-based main system formulation: 70 parts silicone-acrylic emulsion, 1.5 parts polyurethane hardener, 2.5 parts film-forming aid, 0.8 parts wetting and dispersing agent, 0.6 parts defoamer, 0.3 parts thickener, and 6.1 parts deionized water.

[0025] like Figure 1 As shown, the preparation method of the intelligent invisible waterproofing agent of the present invention is as follows: Step 1: Preparation of molybdenum disulfide / titanium dioxide-aromatic resin composite solution Add 20 kg of the mixed solvent to a 50 L stainless steel reactor equipped with a jacketed heating system and variable frequency speed control, and install the high-speed dispersion disc. Start stirring at room temperature, controlling the speed at 1000 rpm. Accurately weigh 0.4 kg of molybdenum disulfide nanosheets and 0.2 kg of nano-titanium dioxide using a precision electronic balance, and slowly and evenly add them to the reactor over 30 minutes. After the addition is complete, maintain a speed of 1000 rpm for continuous high-speed shear dispersion for 30 minutes to obtain a preliminarily dispersed suspension.

[0026] Stirring was stopped, and hot water was introduced through the vessel jacket to raise the system temperature to 50℃±2℃. An ultrasonic probe was then inserted, and ultrasonic treatment was performed at 300W for 45 minutes. This process utilizes the synergistic effect of ultrasonic cavitation and thermal energy to promote the physical embedding and chemical anchoring of titanium dioxide nanoparticles at the edges and surface defect sites of molybdenum disulfide nanosheets, thus initially constructing a heterojunction interface.

[0027] Subsequently, the ultrasonicated composite dispersion was directly heated to 80℃±2℃ (i.e., the subsequent resin dissolution temperature), and stirred at 500 rpm for 1–1.5 hours. This high-temperature curing process provides sufficient energy for the chemical bonding of the heterojunction interface, which can significantly enhance the bonding force and stability between molybdenum disulfide and titanium dioxide.

[0028] After the curing process is complete, maintain the system at 80°C. Weigh 5 kg of pre-crushed petroleum aromatic resin particles (less than 5 mm in diameter) and slowly add them to the reactor in batches over 45 minutes to prevent clumping. During this process, the hydrophobic surfaces of the molybdenum disulfide nanosheets fully integrate with the resin molecules, while the molten resin at high temperature further penetrates and firmly fixes the formed heterostructure. After all the particles have been added, maintain the temperature at 80°C and the stirring speed at 500 rpm for 30 minutes until the resin is completely dissolved, resulting in a homogeneous, viscous molybdenum disulfide / titanium dioxide-aromatic resin composite solution.

[0029] Step 2: Composite polyethylene wax Maintain the high-speed dispersion disc at 5500 rpm and circulate high-temperature heat transfer oil through the jacket to heat the composite liquid obtained in step 1 to 85°C. Accurately weigh 1.5 kg of polyethylene wax micropowder with a particle size D50 of 5 μm and slowly add it to the reactor over 10 minutes. After the addition is complete, maintain the temperature at 85°C and the shear force at 5500 rpm, and continue stirring for 30 minutes to ensure that the polyethylene wax is completely melted and dispersed into uniform micron-sized droplets.

[0030] Step 3: Preparation of photocatalytic composite masterbatch Maintaining a high-speed shearing rate of 5500 rpm, the system was cooled to 60°C at a rate of 1.5°C / min by switching to programmed cooling mode via the jacket. Under continuous high-speed shearing, 2 kg of phenyl-modified silicone oil and 0.3 kg of polymeric block compatibilizer were slowly added dropwise sequentially using a constant flow pump, controlling the dropping rate to ensure completion within 20 minutes. After all materials were added, high-speed shearing was maintained at this temperature for another 35 minutes to obtain a homogeneous and fine photocatalytic composite masterbatch. The masterbatch was transferred to a sealed container for later use.

[0031] Step 4: Preparation of the aqueous host system In a clean 100 L low-speed stirred tank, 70 kg of silicone-acrylic emulsion was added, an anchor-type agitator was installed, and stirring was started at 400 rpm. 2.5 kg of film-forming aid, 0.8 kg of wetting and dispersing agent, and 0.6 kg of defoamer were then accurately added to the emulsion sequentially. After all aids were added, stirring was continued for 12 minutes to obtain a homogeneous aqueous main system.

[0032] Step 5: Pre-emulsification Accurately measure 12 kg of the aqueous master system prepared in step 4 and place it in a 30 L high-speed dispersion tank. Install the toothed dispersion disc and start shearing at 3500 rpm. Slowly pour all the photocatalytic composite masterbatch prepared in step 3 into the dispersion tank, controlling the pouring speed, and complete the addition within 5-8 minutes. At this time, the mixture will undergo a phase inversion process from thin to thick and then thin again, and continue shearing until a uniform, fine, blue-glossy pre-emulsion slurry is formed.

[0033] Step 6: Final compounding The pre-emulsified slurry obtained in step 5 is slowly added to the remaining aqueous main system in the main mixing vessel of step 4 at a low speed of 400 rpm, with the feeding time controlled at about 10 minutes. After the feeding is complete, accurately add 1.5 kg of polyurethane hardener. Increase the stirring speed to 1000 rpm and stir at medium speed for 20 minutes to ensure that the polyurethane hardener is evenly distributed in the complex multiphase system.

[0034] Step 7: Adjusting viscosity and setting volume Dissolve 0.3 kg of thickener in 2 parts deionized water in a beaker to form a homogeneous slurry. Slowly add this thickener slurry to the reactor at 400 rpm. Then, rinse the container with the remaining 4.1 kg of deionized water and add it to the reactor. Reduce the stirring speed to 200 rpm and continue stirring for 40 minutes to fully homogenize the system and achieve the desired application viscosity.

[0035] Step 8: Maturation and Filtration The product obtained in step 7 is pumped into a sealed curing tank and cured for 4 hours in a clean environment at 25°C and 50% relative humidity, allowing the bubbles to escape fully and the components to interact fully. Finally, the cured product is filtered through a 300-mesh funnel and bottled to obtain the milky white intelligent invisible waterproofing agent.

[0036] Example 2 The formulation of the intelligent invisible waterproofing agent of this invention is as follows: Photocatalytic composite masterbatch formulation: 20 parts mixed solvent (10 parts xylene, 10 parts D-limonene), 5 parts petroleum aromatic resin, 0.4 parts molybdenum disulfide nanosheets, 0.2 parts nano titanium dioxide (anatase type), 2.0 parts polyethylene wax micro powder, 2 parts phenyl modified silicone oil, and 0.3 parts polymer block compatibilizer.

[0037] Water-based main system formulation: 68 parts silicone-acrylic emulsion, 2.0 parts polyurethane hardener, 2.5 parts film-forming aid, 0.8 parts wetting and dispersing agent, 0.6 parts defoamer, 0.3 parts thickener, and 6.1 parts deionized water.

[0038] The preparation method of the intelligent invisible waterproofing agent of the present invention: Step 1: Preparation of molybdenum disulfide / titanium dioxide-aromatic resin composite solution Add 20 kg of the mixed solvent to a 50 L stainless steel reactor equipped with a jacketed heating system and variable frequency speed control, and install the high-speed dispersion disc. Start stirring at room temperature, controlling the speed at 1000 rpm. Accurately weigh 0.4 kg of molybdenum disulfide nanosheets and 0.2 kg of nano-titanium dioxide using a precision electronic balance, and slowly and evenly add them to the reactor over 30 minutes. After the addition is complete, maintain a speed of 1000 rpm for continuous high-speed shear dispersion for 30 minutes to obtain a preliminarily dispersed suspension.

[0039] Stirring was stopped, and hot water was introduced through the vessel jacket to raise the system temperature to 50℃±2℃. An ultrasonic probe was then inserted, and ultrasonic treatment was performed at 300W for 45 minutes. This process utilizes the synergistic effect of ultrasonic cavitation and thermal energy to promote the physical embedding and chemical anchoring of titanium dioxide nanoparticles at the edges and surface defect sites of molybdenum disulfide nanosheets, initially constructing a heterojunction interface. Subsequently, the ultrasonicated composite dispersion was directly heated to 80℃±2℃, and stirred at 500 rpm at this temperature for 1–1.5 hours for curing. This high-temperature curing process provides sufficient energy for the chemical bonding of the heterojunction interface, significantly enhancing the bonding force and stability between molybdenum disulfide and titanium dioxide.

[0040] After the curing process is complete, maintain the system at 80°C. Weigh 5 kg of pre-crushed petroleum aromatic resin particles (less than 5 mm in diameter) and slowly add them to the reactor in batches over 45 minutes to prevent clumping. During this process, the hydrophobic surfaces of the molybdenum disulfide nanosheets fully integrate with the resin molecules, while the molten resin at high temperature further penetrates and firmly fixes the formed heterostructure. After all the particles have been added, maintain the temperature at 80°C and the stirring speed at 500 rpm for 30 minutes until the resin is completely dissolved, resulting in a homogeneous, viscous molybdenum disulfide / titanium dioxide-aromatic resin composite solution.

[0041] Step 2: Composite polyethylene wax Maintain the high-speed dispersion disc at 5500 rpm and circulate high-temperature heat transfer oil through the jacket to heat the composite liquid obtained in step 1 to 85°C. Accurately weigh 2.0 kg of polyethylene wax micropowder with a particle size D50 of 5 μm and slowly add it to the reactor over 10 minutes. After the addition is complete, maintain the temperature at 85°C and the shear force at 5500 rpm, and continue stirring for 40 minutes to ensure that the polyethylene wax is completely melted and dispersed into uniform micron-sized droplets.

[0042] Step 3: Preparation of photocatalytic composite masterbatch Maintaining a high-speed shearing rate of 5500 rpm, the system was cooled to 60°C at a rate of 1.5°C / min by switching to programmed cooling mode via the jacket. Under continuous high-speed shearing, 2 kg of phenyl-modified silicone oil and 0.3 kg of polymeric block compatibilizer were slowly added dropwise sequentially using a constant flow pump, controlling the dropping rate to ensure completion within 20 minutes. After all materials were added, high-speed shearing was maintained at this temperature for another 35 minutes to obtain a homogeneous and fine photocatalytic composite masterbatch. The masterbatch was transferred to a sealed container for later use.

[0043] Step 4: Preparation of the aqueous host system In a clean 100 L low-speed stirred tank, 68 kg of silicone-acrylic emulsion was added, an anchor-type agitator was installed, and stirring was started at 400 rpm. 2.5 kg of film-forming aid, 0.8 kg of wetting and dispersing agent, and 0.6 kg of defoamer were then accurately added to the emulsion sequentially. After all aids were added, stirring was continued for 12 minutes to obtain a homogeneous aqueous main system.

[0044] Step 5: Pre-emulsification Accurately measure 12 kg of the aqueous master system prepared in step 4 and place it in a 30 L high-speed dispersion tank. Install the toothed dispersion disc and start shearing at 3500 rpm. Slowly pour all the photocatalytic composite masterbatch prepared in step 3 into the dispersion tank, controlling the pouring speed, and complete the addition within 5-8 minutes. At this time, the mixture will undergo a phase inversion process from thin to thick and then thin again, and continue shearing until a uniform, fine, blue-glossy pre-emulsion slurry is formed.

[0045] Step 6: Final compounding The pre-emulsified slurry obtained in step 5 is slowly added to the remaining aqueous main system while being stirred at a low speed of 400 rpm in the main mixing vessel of step 4, with the feeding time controlled at approximately 10 minutes. After the feeding is complete, accurately add 2.0 kg of polyurethane hardener. Increase the stirring speed to 1000 rpm and stir at medium speed for 20 minutes to ensure that the polyurethane hardener is evenly distributed in the complex multiphase system.

[0046] Step 7: Adjusting viscosity and setting volume Dissolve 0.3 kg of thickener in 2 parts deionized water in a beaker to form a homogeneous slurry. Slowly add this thickener slurry to the reactor at 400 rpm. Then, rinse the container with the remaining 4.1 kg of deionized water and add it to the reactor. Reduce the stirring speed to 200 rpm and continue stirring for 40 minutes to fully homogenize the system and achieve the desired application viscosity.

[0047] Step 8: Maturation and Filtration The product obtained in step 7 is pumped into a sealed curing tank and cured for 4 hours in a clean environment at 25°C and 50% relative humidity, allowing the bubbles to escape fully and the components to interact fully. Finally, the cured product is filtered through a 300-mesh funnel and bottled to obtain the milky white intelligent invisible waterproofing agent.

[0048] Example 3 The formulation of the intelligent invisible waterproofing agent of this invention is as follows: Photocatalytic composite masterbatch formulation: 22 parts mixed solvent (11 parts xylene, 11 parts D-limonene), 5 parts petroleum aromatic resin, 0.3 parts molybdenum disulfide nanosheets, 0.3 parts nano titanium dioxide (anatase type), 1.0 part polyethylene wax powder, 2.5 parts phenyl modified silicone oil, and 0.3 parts polymer block compatibilizer.

[0049] Waterborne main system formulation: 72 parts silicone-acrylic emulsion, 1.0 part polyurethane hardener, 2.5 parts film-forming aid, 0.8 parts wetting and dispersing agent, 0.6 parts defoamer, 0.2 parts thickener, and 5.1 parts deionized water.

[0050] The preparation method of the intelligent invisible waterproofing agent of the present invention: Step 1: Preparation of molybdenum disulfide / titanium dioxide-aromatic resin composite solution 22 kg of the mixed solvent was added to a 50 L stainless steel reactor equipped with a jacketed heating system and variable frequency speed control, and a high-speed dispersion disc was installed. Stirring was started at room temperature, with the speed controlled at 1000 rpm. Using a precision electronic balance, 0.3 kg of molybdenum disulfide nanosheets and 0.3 kg of nano-titanium dioxide were accurately weighed and slowly and evenly added to the reactor over 30 minutes. After the addition was complete, the stirring speed was maintained at 1000 rpm for continuous high-speed shear dispersion for 30 minutes to obtain a preliminarily dispersed suspension.

[0051] Stirring was stopped, and hot water was introduced through the vessel jacket to raise the system temperature to 50℃±2℃. An ultrasonic probe was then inserted, and ultrasonic treatment was performed at 300W for 45 minutes. This process utilizes the synergistic effect of ultrasonic cavitation and thermal energy to promote the physical embedding and chemical anchoring of titanium dioxide nanoparticles at the edges and surface defect sites of molybdenum disulfide nanosheets, initially constructing a heterojunction interface. Subsequently, the ultrasonicated composite dispersion was directly heated to 80℃±2℃, and stirred at 500 rpm at this temperature for 1–1.5 hours for curing. This high-temperature curing process provides sufficient energy for the chemical bonding of the heterojunction interface, significantly enhancing the bonding force and stability between molybdenum disulfide and titanium dioxide.

[0052] After the curing process is complete, maintain the system at 80°C. Weigh 5 kg of pre-crushed petroleum aromatic resin particles (less than 5 mm in diameter) and slowly add them to the reactor in batches over 45 minutes to prevent clumping. During this process, the hydrophobic surfaces of the molybdenum disulfide nanosheets fully integrate with the resin molecules, while the molten resin at high temperature further penetrates and firmly fixes the formed heterostructure. After all the particles have been added, maintain the temperature at 80°C and the stirring speed at 500 rpm for 30 minutes until the resin is completely dissolved, resulting in a homogeneous, viscous molybdenum disulfide / titanium dioxide-aromatic resin composite solution.

[0053] Step 2: Composite polyethylene wax Maintain the high-speed dispersion disc at 5500 rpm and heat the composite liquid obtained in step 1 to 83°C by introducing high-temperature heat transfer oil through the jacket. Accurately weigh 1.5 kg of polyethylene wax micropowder with a particle size D50 of 5 μm and slowly add it to the reactor over 10 minutes. After the addition is complete, maintain the temperature at 83°C and the shear force at 5500 rpm, and continue stirring for 25 minutes to ensure that the polyethylene wax is completely melted and dispersed into uniform micron-sized droplets.

[0054] Step 3: Preparation of photocatalytic composite masterbatch Maintaining a high-speed shearing rate of 5500 rpm, the system was cooled to 60°C at a rate of 1.5°C / min by switching to programmed cooling mode via the jacket. Under continuous high-speed shearing, 2.5 kg of phenyl-modified silicone oil and 0.3 kg of polymeric block compatibilizer were slowly added dropwise sequentially using a constant flow pump, controlling the dropping rate to ensure completion within 20 minutes. After all materials were added, high-speed shearing was maintained at this temperature for another 35 minutes to obtain a homogeneous and fine photocatalytic composite masterbatch. The masterbatch was then transferred to a sealed container for later use.

[0055] Step 4: Preparation of the aqueous host system In a clean 100 L low-speed stirred tank, 72 kg of silicone-acrylic emulsion was added, an anchor-type agitator was installed, and stirring was started at 400 rpm. 2.5 kg of film-forming aid, 0.8 kg of wetting and dispersing agent, and 0.6 kg of defoamer were then accurately added to the emulsion sequentially. After all aids were added, stirring was continued for 12 minutes to obtain a homogeneous aqueous main system.

[0056] Step 5: Pre-emulsification Accurately measure 12 kg of the aqueous master system prepared in step 4 and place it in a 30 L high-speed dispersion tank. Install the toothed dispersion disc and start shearing at 3500 rpm. Slowly pour all the photocatalytic composite masterbatch prepared in step 3 into the dispersion tank, controlling the pouring speed, and complete the addition within 5-8 minutes. At this time, the mixture will undergo a phase inversion process from thin to thick and then thin again, and continue shearing until a uniform, fine, blue-glossy pre-emulsion slurry is formed.

[0057] Step 6: Final compounding The pre-emulsified slurry obtained in step 5 is slowly added to the remaining aqueous main system in the main mixing vessel of step 4 at a low speed of 400 rpm, with the feeding time controlled at about 10 minutes. After the feeding is complete, accurately add 1.5 kg of polyurethane hardener. Increase the stirring speed to 1000 rpm and stir at medium speed for 20 minutes to ensure that the polyurethane hardener is evenly distributed in the complex multiphase system.

[0058] Step 7: Adjusting viscosity and setting volume Dissolve 0.3 kg of thickener in 2 parts deionized water in a beaker to form a homogeneous slurry. Slowly add this thickener slurry to the reactor at 400 rpm. Then, rinse the container with the remaining 3.1 kg of deionized water and add it to the reactor. Reduce the stirring speed to 200 rpm and continue stirring for 40 minutes to fully homogenize the system and achieve the desired application viscosity.

[0059] Step 8: Maturation and Filtration The product obtained in step 7 is pumped into a sealed curing tank and cured for 4 hours in a clean environment at 25°C and 50% relative humidity, allowing the bubbles to escape fully and the components to interact fully. Finally, the cured product is filtered through a 300-mesh funnel and bottled to obtain the milky white intelligent invisible waterproofing agent.

[0060] Example 4 The formulation of the intelligent invisible waterproofing agent of this invention is as follows: Photocatalytic composite masterbatch formulation: 20 parts mixed solvent (10 parts xylene, 10 parts D-limonene), 5 parts petroleum aromatic resin, 0.3 parts molybdenum disulfide nanosheets, 0.15 parts nano titanium dioxide (anatase type), 1.0 part polyethylene wax micro powder, 1.8 parts phenyl modified silicone oil, and 0.3 parts polymer block compatibilizer.

[0061] Water-based main system formulation: 73 parts silicone-acrylic emulsion, 1.2 parts polyurethane hardener, 2.5 parts film-forming aid, 0.8 parts wetting and dispersing agent, 0.6 parts defoamer, 0.3 parts thickener, and 6.1 parts deionized water.

[0062] The preparation method of the intelligent invisible waterproofing agent of the present invention: Step 1: Preparation of molybdenum disulfide / titanium dioxide-aromatic resin composite solution Add 20 kg of the mixed solvent to a 50 L stainless steel reactor equipped with a jacketed heating system and variable frequency speed control, and install the high-speed dispersion disc. Start stirring at room temperature, controlling the speed at 1000 rpm. Accurately weigh 0.3 kg of molybdenum disulfide nanosheets and 0.15 kg of nano-titanium dioxide using a precision electronic balance, and slowly and evenly add them to the reactor over 30 minutes. After the addition is complete, maintain a speed of 1000 rpm for continuous high-speed shear dispersion for 30 minutes to obtain a preliminarily dispersed suspension.

[0063] Stirring was stopped, and hot water was introduced through the vessel jacket to raise the system temperature to 50℃±2℃. An ultrasonic probe was then inserted, and ultrasonic treatment was performed at 300W for 45 minutes. This process utilizes the synergistic effect of ultrasonic cavitation and thermal energy to promote the physical embedding and chemical anchoring of titanium dioxide nanoparticles at the edges and surface defect sites of molybdenum disulfide nanosheets, initially constructing a heterojunction interface. Subsequently, the ultrasonicated composite dispersion was directly heated to 80℃±2℃, and stirred at 500 rpm at this temperature for 1–1.5 hours for curing. This high-temperature curing process provides sufficient energy for the chemical bonding of the heterojunction interface, significantly enhancing the bonding force and stability between molybdenum disulfide and titanium dioxide.

[0064] After the curing process is complete, maintain the system at 80°C. Weigh 5 kg of pre-crushed petroleum aromatic resin particles (less than 5 mm in diameter) and slowly add them to the reactor in batches over 45 minutes to prevent clumping. During this process, the hydrophobic surfaces of the molybdenum disulfide nanosheets fully integrate with the resin molecules, while the molten resin at high temperature further penetrates and firmly fixes the formed heterostructure. After all the particles have been added, maintain the temperature at 80°C and the stirring speed at 500 rpm for 30 minutes until the resin is completely dissolved, resulting in a homogeneous, viscous molybdenum disulfide / titanium dioxide-aromatic resin composite solution.

[0065] Step 2: Composite polyethylene wax Maintain the high-speed dispersion disc at 5500 rpm and circulate high-temperature heat transfer oil through the jacket to heat the composite liquid obtained in step 1 to 85°C. Accurately weigh 1.0 kg of polyethylene wax micropowder with a particle size D50 of 5 μm and slowly add it to the reactor over 10 minutes. After the addition is complete, maintain the temperature at 85°C and the shear force at 5500 rpm, and continue stirring for 25 minutes to ensure that the polyethylene wax is completely melted and dispersed into uniform micron-sized droplets.

[0066] Step 3: Preparation of photocatalytic composite masterbatch Maintaining a high-speed shearing rate of 5500 rpm, the system was cooled to 60°C at a rate of 2°C / min by switching to programmed cooling mode via the jacket. Under continuous high-speed shearing, 1.8 kg of phenyl-modified silicone oil and 0.3 kg of polymeric block compatibilizer were slowly added dropwise using a constant flow pump, controlling the dropping rate to ensure completion within 20 minutes. After all materials were added, high-speed shearing was maintained at this temperature for another 35 minutes to obtain a homogeneous and fine photocatalytic composite masterbatch. The masterbatch was then transferred to a sealed container for later use.

[0067] Step 4: Preparation of the aqueous host system In a clean 100 L low-speed stirred tank, 73 kg of silicone-acrylic emulsion was added, an anchor-type agitator was installed, and stirring was started at 400 rpm. 2.5 kg of film-forming aid, 0.8 kg of wetting and dispersing agent, and 0.6 kg of defoamer were then accurately added to the emulsion sequentially. After all aids were added, stirring was continued for 12 minutes to obtain a homogeneous aqueous main system.

[0068] Step 5: Pre-emulsification Accurately measure 12 kg of the aqueous master system prepared in step 4 and place it in a 30 L high-speed dispersion tank. Install the toothed dispersion disc and start shearing at 3500 rpm. Slowly pour all the photocatalytic composite masterbatch prepared in step 3 into the dispersion tank, controlling the pouring speed, and complete the addition within 5-8 minutes. At this time, the mixture will undergo a phase inversion process from thin to thick and then thin again, and continue shearing until a uniform, fine, blue-glossy pre-emulsion slurry is formed.

[0069] Step 6: Final compounding The pre-emulsified slurry obtained in step 5 is slowly added to the remaining aqueous main system in the main mixing vessel of step 4 at a low speed of 400 rpm, with the feeding time controlled at approximately 10 minutes. After the feeding is complete, 1.2 kg of polyurethane hardener is accurately added. The stirring speed is increased to 1000 rpm, and the mixture is stirred at medium speed for 20 minutes to ensure that the polyurethane hardener is evenly distributed in the complex multiphase system.

[0070] Step 7: Adjusting viscosity and setting volume Dissolve 0.3 kg of thickener in 2 parts deionized water in a beaker to form a homogeneous slurry. Slowly add this thickener slurry to the reactor at 400 rpm. Then, rinse the container with the remaining 4.1 kg of deionized water and add it to the reactor. Reduce the stirring speed to 200 rpm and continue stirring for 40 minutes to fully homogenize the system and achieve the desired application viscosity.

[0071] Step 8: Maturation and Filtration The product obtained in step 7 is pumped into a sealed curing tank and cured for 4 hours in a clean environment at 25°C and 50% relative humidity, allowing the bubbles to escape fully and the components to interact fully. Finally, the cured product is filtered through a 300-mesh funnel and bottled to obtain the milky white intelligent invisible waterproofing agent.

[0072] Comparative Example 1 formula: Photocatalytic composite masterbatch: 20 kg mixed solvent (10 kg xylene, 10 kg D-limonene), 5 kg petroleum aromatic resin, 0.4 kg molybdenum disulfide nanosheets, 0.2 kg nano titanium dioxide, 1.5 kg polyethylene wax powder, 2 kg phenyl modified silicone oil, and 0.3 kg polymer block compatibilizer.

[0073] Water-based main system: 70 kg silicone-acrylic emulsion, 1.5 kg polyurethane hardener, 2.5 kg film-forming aid, 0.8 kg wetting and dispersing agent, 0.6 kg defoamer, 0.3 kg thickener, and 6.1 kg deionized water.

[0074] Preparation method: Step 1: Preparation of molybdenum disulfide / titanium dioxide-aromatic resin composite solution Add 20 kg of the mixed solvent to a 50 L stainless steel reactor equipped with a jacketed heating system and variable frequency speed control, and install the high-speed dispersion disc. Start stirring at room temperature, controlling the speed at 1000 rpm. Accurately weigh 0.4 kg of molybdenum disulfide nanosheets and 0.2 kg of nano-titanium dioxide using a precision electronic balance, and slowly and evenly add them to the reactor over 30 minutes. After the addition is complete, maintain a speed of 1000 rpm for continuous high-speed shear dispersion for 30 minutes to obtain a preliminarily dispersed suspension.

[0075] Stop stirring and introduce hot water through the vessel jacket to raise the system temperature to 50℃±2℃. Then, insert an ultrasonic probe and perform ultrasonic treatment at 300W power for 45 minutes. Next, directly heat the ultrasonicated composite dispersion to 80℃±2℃ and maintain this temperature with stirring for 1 hour. Weigh 5 kg of pre-crushed petroleum aromatic resin particles (less than 5 mm in diameter) and slowly add them to the reactor in batches over 45 minutes to prevent agglomeration. During this process, the hydrophobic surfaces of the molybdenum disulfide nanosheets fully bind with the resin molecules. After all the particles have been added, maintain the temperature at 80℃ and the stirring speed at 500 rpm for 30 minutes until the resin is completely dissolved, resulting in a homogeneous, viscous molybdenum disulfide / titanium dioxide-aromatic resin composite solution.

[0076] Step 2: Composite polyethylene wax Maintain the high-speed dispersion disc at 5500 rpm and circulate high-temperature heat transfer oil through the jacket to heat the composite liquid obtained in step 1 to 85°C. Accurately weigh 1.5 kg of polyethylene wax micropowder with a particle size D50 of 5 μm and slowly add it to the reactor over 10 minutes. After the addition is complete, maintain the temperature at 85°C and the shear force at 5500 rpm, and continue stirring for 30 minutes.

[0077] Step 3: Preparation of photocatalytic composite masterbatch This comparative example uses a rapid cooling process for comparison. A high-speed shearing process of 5500 rpm was maintained, the heat transfer oil in the reactor jacket was rapidly emptied, and the system was immediately switched to ice-water circulation, rapidly cooling the system from 85°C to 60°C within 15 minutes. Under continuous high-speed shearing, 2 kg of phenyl-modified silicone oil and 0.3 kg of polymeric block compatibilizer were slowly added dropwise using a constant flow pump, controlling the dropping rate to complete the addition within 20 minutes. After all materials were added, high-speed shearing was maintained at this temperature for another 35 minutes to obtain the composite masterbatch. Compared to Example 1, this masterbatch showed decreased gloss and a slightly dull appearance; microscopically, the polyethylene wax failed to form uniform and fine microcrystals. The masterbatch was transferred to a sealed container for later use.

[0078] Step 4: Preparation of the aqueous host system In a clean 100 L low-speed stirred tank, 70 kg of silicone-acrylic emulsion was added, an anchor-type agitator was installed, and stirring was started at 400 rpm. 2.5 kg of film-forming aid, 0.8 kg of wetting and dispersing agent, and 0.6 kg of defoamer were then accurately added to the emulsion sequentially. After all aids were added, stirring was continued for 12 minutes to obtain a homogeneous aqueous main system.

[0079] Step 5: Pre-emulsification Accurately measure 12 kg of the aqueous masterbatch prepared in step 4 and place it in a 30 L high-speed dispersion tank. Install the toothed dispersion disc and start shearing at 3500 rpm. Slowly pour all the photocatalytic composite masterbatch prepared in step 3 into the dispersion tank, controlling the pouring speed, and complete the addition within 5-8 minutes. Continue shearing until a uniform pre-emulsion slurry is formed.

[0080] Step 6: Final compounding The pre-emulsified slurry obtained in step 5 is slowly added to the remaining aqueous main system while being stirred at a low speed of 400 rpm in the main mixing vessel of step 4, with the feeding time controlled at approximately 10 minutes. After the feeding is complete, accurately add 1.5 kg of polyurethane hardener. Increase the stirring speed to 1000 rpm and stir at medium speed for 20 minutes.

[0081] Step 7: Adjusting viscosity and setting volume Dissolve 0.3 kg of thickener in 2 kg of deionized water in a beaker to form a homogeneous slurry. Slowly add the thickener slurry to the vessel while stirring at 400 rpm. Then, rinse the container with the remaining 4.1 kg of deionized water and add it to the vessel. Reduce the stirring speed to 200 rpm and continue stirring for 40 minutes.

[0082] Step 8: Maturation and Filtration The product obtained in step 7 was pumped into a sealed curing tank and cured for 4 hours in a clean environment at 25°C and 50% relative humidity. After curing, the product was found to be slightly milky white and turbid, with a small amount of white precipitate at the bottom caused by the coarsening of polyethylene wax microcrystals due to rapid cooling, which affected the uniformity of the system's appearance and storage stability. Finally, the cured product was filtered through a 300-mesh funnel. Slight resistance was felt during filtration, and the product was bottled to obtain a milky white, opaque liquid.

[0083] Comparative Example 2 formula: Photocatalytic composite masterbatch: 20 kg mixed solvent (10 kg xylene, 10 kg D-limonene), 5 kg petroleum aromatic resin, 0.4 kg molybdenum disulfide nanosheets, 0.2 kg nano titanium dioxide, 1.5 kg polyethylene wax powder, 2 kg phenyl modified silicone oil, and 0.3 kg polymer block compatibilizer.

[0084] Water-based main system: 70 kg silicone-acrylic emulsion, 1.5 kg polyurethane hardener, 2.5 kg film-forming aid, 0.8 kg wetting and dispersing agent, 0.6 kg defoamer, 0.3 kg thickener, and 6.1 kg deionized water.

[0085] Preparation method: Step 1: Preparation of molybdenum disulfide / titanium dioxide-aromatic resin composite solution Add 20 kg of the mixed solvent to a 50 L stainless steel reactor equipped with a jacketed heating system and variable frequency speed control, and install the high-speed dispersion disc. Start stirring at room temperature, controlling the speed at 1000 rpm. Accurately weigh 0.4 kg of molybdenum disulfide nanosheets and 0.2 kg of nano-titanium dioxide using a precision electronic balance, and slowly and evenly add them to the reactor over 30 minutes. After the addition is complete, maintain a speed of 1000 rpm for continuous high-speed shear dispersion for 30 minutes to obtain a preliminarily dispersed suspension.

[0086] Stop stirring and introduce hot water through the vessel jacket to raise the system temperature to 50℃±2℃. Then, insert an ultrasonic probe and perform ultrasonic treatment at 300W power for 45 minutes. Subsequently, heat the ultrasonicated composite dispersion directly to 80℃±2℃ and maintain this temperature with stirring for 1 hour.

[0087] Weigh 5 kg of pre-crushed petroleum aromatic resin particles (less than 5 mm in diameter) and slowly add them in batches to the reactor over 45 minutes to prevent clumping. During this process, the hydrophobic surfaces of the molybdenum disulfide nanosheets fully bond with the resin molecules. After all the particles have been added, maintain the temperature at 80°C and the stirring speed at 500 rpm for 30 minutes until the resin is completely dissolved, resulting in a homogeneous, viscous molybdenum disulfide / titanium dioxide-aromatic resin composite solution.

[0088] Step 2: Composite polyethylene wax Maintain the high-speed dispersion disc at 5500 rpm and circulate high-temperature heat transfer oil through the jacket to heat the composite liquid obtained in step 1 to 85°C. Accurately weigh 1.5 kg of polyethylene wax micropowder with a particle size D50 of 5 μm and slowly add it to the reactor over 10 minutes. After the addition is complete, maintain the temperature at 85°C and the shear force at 5500 rpm, and continue stirring for 30 minutes.

[0089] Step 3: Preparation of photocatalytic composite masterbatch Maintaining a high-speed shearing rate of 5500 rpm, the system was cooled to 60°C at a rate of 1.5°C / min by switching to programmed cooling mode via the jacket. Under continuous high-speed shearing, 2 kg of phenyl-modified silicone oil and 0.3 kg of polymeric block compatibilizer were slowly added dropwise sequentially using a constant flow pump, controlling the dropping rate to ensure completion within 20 minutes. After all materials were added, high-speed shearing was maintained at this temperature for another 35 minutes to obtain a homogeneous and fine photocatalytic composite masterbatch. The masterbatch was transferred to a sealed container for later use.

[0090] Step 4: Preparation of the aqueous host system In a clean 100 L low-speed stirred tank, 70 kg of silicone-acrylic emulsion was added, an anchor-type agitator was installed, and stirring was started at 400 rpm. 2.5 kg of film-forming aid, 0.8 kg of wetting and dispersing agent, and 0.6 kg of defoamer were then accurately added to the emulsion sequentially. After all aids were added, stirring was continued for 12 minutes to obtain a homogeneous aqueous main system.

[0091] Step 5: Final compounding (the pre-emulsification step is omitted in this comparative example for comparison) In step 4, under low-speed stirring at 400 rpm in the main mixing vessel, the photocatalytic composite masterbatch prepared in step 3 was slowly and directly poured into the aqueous main system in a thin stream, with the feeding time controlled at approximately 10 minutes. During the feeding process, white flocculent matter was clearly observed to appear immediately in the system, accompanied by a significant tendency for oil-water separation. After the feeding was completed, 1.5 kg of polyurethane hardening agent was accurately added. The stirring speed was increased to 1000 rpm, and the system was stirred at medium speed for 20 minutes. The system remained turbid and uneven, with fine oil droplets on the surface, indicating severe phase separation and failure to form a stable emulsion.

[0092] Step 6: Adjusting viscosity and setting volume After pre-dissolving 0.3 kg of thickener in 2 kg of deionized water in a beaker, the thickener slurry was attempted to be added to the stirred tank at 400 rpm. However, due to the instability of the system, the thickening effect was abnormal, and local gel lumps were formed. Subsequently, the remaining deionized water was added, the stirring speed was reduced to 200 rpm, and stirring was continued for 40 minutes.

[0093] Step 7: Mature and Filter The product obtained in step 6 was pumped into a curing tank and left to stand for 4 hours. After curing, the product exhibited severe stratification, with a semi-transparent clear liquid (mainly aqueous phase) on top and a thick precipitate (mainly demulsified oil phase and agglomerated solids) on the bottom. Attempts were made to filter the product using a 300-mesh funnel, but the filter was quickly clogged by the paste-like substance, making filtration impossible and ultimately yielding only a small amount of coarse liquid with a very strong granular texture.

[0094] Table 1. Test results of various performance aspects of the new intelligent invisible waterproofing agent In summary, through the performance comparison of the embodiments and comparative examples in Table 1, the molybdenum disulfide / titanium dioxide synergistic modified smart invisible waterproofing agent provided by the present invention not only endows the substrate with excellent superhydrophobicity, but also possesses visible light-responsive self-cleaning function and excellent durability. The fundamental reason lies in the fact that molybdenum disulfide nanosheets play multiple key roles in the system. Their hydrophobic surface tightly binds with petroleum aromatic resin, effectively constructing a low surface energy microstructure. The heterojunction formed by molybdenum disulfide and nano-titanium dioxide significantly improves the photogenerated carrier separation efficiency, endowing the coating with the ability to actively degrade surface contaminants. Simultaneously, the programmed cooling process ensures that the polyethylene wax exists in a fine and uniform microcrystalline form, providing wear resistance while maintaining the coating's transparency. The pre-emulsification process achieves stable bonding between the high-content functional masterbatch and the aqueous emulsion, avoiding phase separation.

[0095] Compared with the prior art, the beneficial effects of the present invention are specifically reflected through performance comparison: (1) The introduction of the molybdenum disulfide / titanium dioxide synergistic system not only endows the coating with excellent superhydrophobicity, but also adds a significant photocatalytic self-cleaning function, realizing the leap from "passive protection" to "active purification"; (2) The intrinsic lubricity and two-dimensional lamellar structure of molybdenum disulfide synergistically improve the wear resistance and density of the coating; (3) The programmed cooling process is the key to ensuring the "invisibility" effect of the coating. Its absence will directly lead to the coarsening of polyethylene wax microcrystals, causing the waterproofing agent to turn white and fail (as in Comparative Example 1); (4) The pre-emulsification process is the core to ensure the uniform dispersion of functional nanomaterials in complex multiphase systems, product storage stability and construction film formation. Its absence will cause the oil and water phases to separate, and the product will completely fail (as in Comparative Example 2); (5) By adjusting the component ratio, a series of products with different performance requirements such as high wear resistance, high penetration or strong self-cleaning can be flexibly prepared.

[0096] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of their technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An invisible waterproofing agent based on the synergistic photocatalysis of molybdenum disulfide / titanium dioxide, characterized in that, This invisible waterproofing agent comprises a photocatalytic composite masterbatch and a water-based main system; The photocatalytic composite masterbatch components are in the following mass proportions: 18-22 parts mixed solvent, 4-6 parts petroleum aromatic resin, 0.2-0.6 parts molybdenum disulfide nanosheets, 0.1-0.3 parts nano titanium dioxide, 1-2 parts polyethylene wax powder, 1.5-2.5 parts phenyl modified silicone oil, and 0.2-0.4 parts polymer block compatibilizer.

2. The invisible waterproofing agent based on the synergistic photocatalysis of molybdenum disulfide / titanium dioxide according to claim 1, characterized in that, The water-based main system components are in the following mass proportions: 68-75 parts silicone-acrylic emulsion, 1-2 parts polyurethane hardener, 2-3 parts film-forming aid, 0.5-1 part wetting and dispersing agent, 0.4-0.8 parts defoamer, 0.2-0.4 parts thickener, and 4-8 parts deionized water.

3. A method for preparing an invisible waterproofing agent based on the synergistic photocatalysis of molybdenum disulfide / titanium dioxide, characterized in that, This method is used to prepare the invisible waterproofing agent as described in claim 1, and the specific steps are as follows: Step 1: Add molybdenum disulfide nanosheets and nano-titanium dioxide to a mixed solvent and disperse them at high speed under high temperature to obtain a preliminary dispersion. Then, sonicate the dispersion to obtain a uniform and stable molybdenum disulfide / titanium dioxide composite dispersion. Continue stirring and maintaining the composite dispersion at a specified speed and temperature. Slowly add petroleum aromatic resin and continue heating and stirring to fully combine the resin molecules with the hydrophobic surface of molybdenum disulfide. At the same time, the resin can also penetrate and adhere to the formed heterostructure to obtain a uniform composite functional resin liquid. Step 2: After heating the composite functional resin liquid, add polyethylene wax powder under high-speed shearing, and stir while maintaining the temperature and shear force to make the polyethylene wax completely melt and disperse. Step 3: Cool the system obtained in Step 2 to the specified temperature, and add phenyl modified silicone oil and polymer block compatibilizer in sequence under continuous high-speed shearing. After the addition is completed, continue shearing to obtain photocatalytic composite masterbatch. Step 4: Place the silicone-acrylic emulsion in a reaction vessel, and add the film-forming aid, wetting and dispersing agent and defoamer in sequence under low-speed stirring, and stir to obtain a dispersed emulsion; Step 5: Under high-speed shearing, the photocatalytic composite masterbatch obtained in step 3 is slowly added to a partially dispersed emulsion to form a uniform pre-emulsion slurry. Step 6: Under low-speed stirring, slowly add the pre-emulsified slurry to the remaining dispersion emulsion, then add the polyurethane hardener, and then stir at medium speed at the specified speed to ensure uniform mixing; Step 7: Predissolve the thickener in some deionized water and add it to the system, then add the remaining deionized water and continue stirring at the specified speed; Step 8: Let the obtained product stand at room temperature to mature, then filter it through a precision filter to obtain the finished invisible waterproofing agent.

4. The preparation method of the invisible waterproofing agent based on the synergistic photocatalysis of molybdenum disulfide / titanium dioxide according to claim 3, characterized in that, In step 1, the molybdenum disulfide nanosheets have a few-layer structure with 1 to 5 layers, a lateral dimension of 0.2 to 1.5 μm, and a purity of ≥99%.

5. The preparation method of the invisible waterproofing agent based on the synergistic photocatalysis of molybdenum disulfide / titanium dioxide according to claim 3 or 4, characterized in that, In step 1, the nano-titanium dioxide is anatase type with a particle size of 10~50nm.

6. The preparation method of the invisible waterproofing agent based on the synergistic photocatalysis of molybdenum disulfide / titanium dioxide according to claim 5, characterized in that, The mass ratio of molybdenum disulfide nanosheets to nano-titanium dioxide is (2:1) to (3:1).

7. The preparation method of the invisible waterproofing agent based on the synergistic photocatalysis of molybdenum disulfide / titanium dioxide according to claim 6, characterized in that, The phenyl-modified silicone oil described in step 3 has a phenyl content of 15% to 35% and a viscosity of 500 to 2000 mPa·s.

8. The preparation method of the invisible waterproofing agent based on the synergistic photocatalysis of molybdenum disulfide / titanium dioxide according to claim 5, characterized in that, In step 3, the polymeric block compatibilizer is one or a combination of two of ethylene oxide-propylene oxide block copolymers and polyether-modified polysiloxanes.

9. The preparation method of the invisible waterproofing agent based on the synergistic photocatalysis of molybdenum disulfide / titanium dioxide according to claim 5, characterized in that, In step 4, the solid content of the silicone-acrylic emulsion is 40% to 60%, and the glass transition temperature is 15 to 25°C.

10. The method for preparing the invisible waterproofing agent based on the synergistic photocatalysis of molybdenum disulfide / titanium dioxide according to claim 5, characterized in that, In step 5, the amount of the partially dispersed emulsion used for pre-emulsification is 10% to 20% of the total amount of the dispersed emulsion.

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