Heat-insulation and heat-preservation water-based colorful exterior wall coating and preparation method thereof

Abstract

The invention relates to the technical field of building coatings, in particular to a heat-insulation and heat-preservation water-based colorful exterior wall coating and a preparation method thereof. The coating is prepared from the following raw materials in parts by weight: 15-25 parts of a water-based film-forming emulsion, 10-18 parts of nano silicon dioxide aerogel, 6-12 parts of ceramic far infrared powder, 7-10 parts of hollow silicon dioxide glass beads, 18 parts of hydroxypropyl starch, 3 parts of glycerol, 5 parts of phthalocyanine blue, 1.5 parts of a sodium polycarboxylate dispersant, 0.8 part of a fatty acid polyoxyethylene ether wetting agent, 0.6 part of an organic silicon defoaming agent and 0.8-1.8 parts of a thickening agent. The coating is prepared from the following components in parts by weight: 1 part of a silane coupling agent KH560, 3-5 parts of a coalescing agent, 12 parts of talcum powder and 18-20 parts of deionized water. According to the heat-insulation and heat-preservation water-based colorful exterior wall coating and the preparation method thereof, multiple inherent technical defects in the prior art are effectively overcome, the comprehensive performance of a product is remarkably improved, and the heat-insulation and heat-preservation water-based colorful exterior wall coating and the preparation method thereof have outstanding substantive features and remarkable progress.

Description

Technical Field

[0001] This invention relates to the field of architectural coatings technology, specifically to a heat-insulating water-based multicolor exterior wall coating and its preparation method. Background Technology

[0002] As an important material for building energy conservation and decoration, water-based exterior wall coatings, which combine thermal insulation performance with colorful decorative effects, have become a market trend due to their environmental protection and aesthetic advantages, as the construction industry continues to raise its requirements for energy conservation, emission reduction and appearance decoration. However, existing water-based colorful exterior wall thermal insulation coatings still have many technical defects and are difficult to meet the actual application needs.

[0003] Existing products mostly employ a single thermal insulation mechanism, lacking synergistic effects from multiple mechanisms, resulting in low thermal insulation efficiency and an inability to meet the high energy-saving standards of modern buildings. Nano-insulating powders are prone to agglomeration during application, exhibiting poor compatibility with film-forming systems. Conventional dispersion processes cannot achieve uniform powder dispersion, leading to a significant decrease in the coating's thermal insulation performance. Film-forming emulsions often employ a single type, creating an inherent conflict between film-forming properties and weather resistance, making it difficult to achieve both simultaneously. This results in insufficient coating adhesion, and long-term outdoor use is prone to aging and discoloration.

[0004] The preparation and composite process design of multi-colored particles are unreasonable, resulting in easy breakage and color bleeding of the particles. They are also prone to agglomeration during storage, and stratification easily occurs when the insulating filler and colored particles are mixed due to density differences. Residual air bubbles are also a significant problem in the process. Furthermore, existing technologies are mostly simple superpositions of single insulating and multi-colored technologies, failing to achieve organic synergy. This makes it impossible to simultaneously resolve the contradictions between insulating efficiency, decorative stability, and physicochemical properties, leading to poor overall product performance. Additionally, the process parameters have poor adaptability, making it difficult to balance repeatability in industrial production with performance stability in actual use. Summary of the Invention

[0005] The primary objective of this invention is to provide a heat-insulating, water-based, multi-colored exterior wall coating and its preparation method.

[0006] A further objective of this invention is to provide a heat-insulating and thermally insulating water-based multicolor exterior wall coating, made from the following raw materials in parts by weight: 15-25 parts of water-based film-forming emulsion, 10-18 parts of nano-silica aerogel, 6-12 parts of ceramic far-infrared powder, 7-10 parts of hollow silica glass microspheres, 18 parts of hydroxypropyl starch, 3 parts of glycerin, 5 parts of phthalocyanine blue, 1.5 parts of sodium polycarboxylate dispersant, 0.8 parts of fatty acid polyoxyethylene ether wetting agent, 0.6 parts of organosilicon defoamer, 0.8-1.8 parts of thickener, 0.8-1.5 parts of silane coupling agent KH560, 3-5 parts of film-forming aid, 12 parts of talc, and 18-20 parts of deionized water; wherein the water-based film-forming emulsion is a water-based acrylic emulsion, or a compound of a water-based acrylic emulsion and a water-based polyurethane emulsion.

[0007] Preferably, the thickener is hydroxyethyl cellulose, or a compound of hydroxyethyl cellulose and a polyurethane-associated thickener; the film-forming aid is propylene glycol methyl ether acetate, or a compound of propylene glycol methyl ether acetate and dodecyl ester.

[0008] A method for preparing the aforementioned heat-insulating water-based multicolor exterior wall coating includes the following steps: (1) Modification treatment: Nano-silica aerogel was mixed with silane coupling agent KH560 using a high-speed mechanical stirrer and stirred at a speed of 500 rpm to obtain modified nano-aerogel; Hydroxypropyl starch, glycerol and phthalocyanine blue were mixed using a twin-screw extruder and plasticized and extruded at 120 degrees Celsius and 80 rpm. After extrusion, the mixture was crushed and sieved by a high-speed pulverizer to obtain colorful particles; (2) Base material preparation: Sodium polycarboxylate dispersant and fatty acid polyoxyethylene ether wetting agent were added to deionized water using a high-speed disperser and stirred at 800 rpm until completely dissolved. Talc powder, modified nano aerogel and ceramic far-infrared powder were added in sequence and the temperature was raised to 40 degrees Celsius for dispersion treatment. Then, aqueous film-forming emulsion and film-forming aid were added and stirred at 600 rpm until the system was uniform and without layering. Finally, organosilicon defoamer and thickener were added to adjust the viscosity to 80 KU to obtain the base material. (3) Composite molding: Hollow silica glass microspheres and multicolored particles are added to the base material using a low-speed stirrer. The mixture is stirred at a low speed of 300 rpm until it is uniform and free of agglomeration. The mixture is then allowed to stand to defoam until there are no obvious bubbles in the system, thus obtaining the heat-insulating water-based multicolored exterior wall coating.

[0009] Preferably, in step (1), the mixing temperature of the nano-silica aerogel and the silane coupling agent KH560 is 60 to 70 degrees Celsius, and the mixing time is 60 to 90 minutes.

[0010] Preferably, in step (1), the sieving of the multicolored particles is to pass them through a 100 to 200 mesh sieve to obtain multicolored particles of the corresponding particle size.

[0011] Preferably, in step (2), the dispersion speed of talc powder, modified nano aerogel and ceramic far-infrared powder is 1200 to 1500 revolutions per minute, the dispersion time is 25 to 40 minutes, and the dispersion is carried out until there are no obvious particles in the system and the particle size is ≤5 micrometers.

[0012] Preferably, in step (2), when the aqueous film-forming emulsion is a mixture of aqueous acrylic emulsion and aqueous polyurethane emulsion, the aqueous acrylic emulsion is first added and stirred at 600 rpm for 20 minutes, and then the aqueous polyurethane emulsion is added and stirred for another 15 minutes until the system is uniform and without layering.

[0013] Preferably, in step (3), a step-by-step feeding method is adopted. First, hollow silica glass microspheres are added to the base material and stirred for 10 minutes, then colorful particles are added and stirred for another 15 minutes until uniform and free of agglomeration.

[0014] Preferably, in step (3), the time for standing and defoaming is 20 to 30 minutes.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. The thermal insulation water-based multicolor exterior wall coating and its preparation method provided by the present invention effectively overcome many inherent technical defects in the prior art, achieve a significant improvement in the overall performance of the product, and have outstanding substantive features and significant progress.

[0016] 2. This invention establishes a multi-layered synergistic thermal insulation mechanism, breaking through the efficiency bottleneck of single thermal insulation methods and significantly improving the core thermal insulation performance of the coating, fully meeting the high energy-saving application requirements of modern buildings. Through targeted modification of the nanoparticles, the technical problem of easy agglomeration of nanoparticles is fundamentally solved, improving the compatibility between the thermal insulation powder and the film-forming system, ensuring the uniform dispersion of the thermal insulation components in the system, and effectively avoiding the attenuation of thermal insulation efficiency.

[0017] 3. This invention employs emulsion compounding technology to synergistically leverage the film-forming and weather-resistant advantages of different emulsions. This not only ensures the film-forming effect of the coating but also significantly improves the weather resistance and adhesion of the coating, thereby greatly extending the outdoor service life of the coating.

[0018] 4. This invention solves the problems of easy breakage and color bleeding of multicolored particles by optimizing the step-by-step preparation and composite molding process, ensuring the stability of the multicolored particles during storage and use, effectively avoiding the stratification phenomenon when the heat insulation filler and multicolored particles are mixed, solving the problem of residual air bubbles in the process, and improving the overall stability of the product.

[0019] 5. The core technical features of this invention are not simply superimposed, but form an organic whole that supports each other. It precisely solves the inherent contradictions between heat insulation efficiency and decorativeness, film formation and weather resistance in the prior art, so that the various performance indicators of the product can reach excellent levels at the same time, and the process parameters are highly adaptable and the operating range is wide. Detailed Implementation

[0020] The technical solutions in the embodiments of the present invention will be clearly and completely described below. 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.

[0021] Example 1:

[0022] Raw material ratio: The composition includes: 22 parts water-based acrylic emulsion, 10 parts nano-silica aerogel, 6 parts ceramic far-infrared powder, 8 parts hollow silica glass microspheres, 4 parts propylene glycol methyl ether acetate, 18 parts hydroxypropyl starch, 5 parts phthalocyanine blue, 3 parts glycerin, 1.5 parts sodium polycarboxylate dispersant, 0.8 parts fatty acid polyoxyethylene ether wetting agent, 0.6 parts silicone defoamer, 1.2 parts hydroxyethyl cellulose thickener, 0.8 parts silane coupling agent KH560, 20 parts deionized water, and 12 parts talc.

[0023] Preparation steps: (1) Modification treatment: Using a high-speed mechanical stirrer, nano-silica aerogel is mixed with silane coupling agent KH560 and stirred for 60 minutes at 60 degrees Celsius and 500 rpm to obtain modified nano-aerogel, which effectively solves the technical problem of easy agglomeration of nano-powders in the prior art; Using a twin-screw extruder, hydroxypropyl starch, glycerol and phthalocyanine blue are mixed and plasticized and extruded at 120 degrees Celsius and 80 rpm. After extrusion, it is crushed by a high-speed pulverizer and then screened through a 200-mesh sieve to obtain multicolored particles with a particle size of 0.1 mm, which effectively solves the problem of easy breakage of colored particles in the prior art.

[0024] (2) Base material preparation: Using a high-speed disperser, sodium polycarboxylate dispersant and fatty acid polyoxyethylene ether wetting agent were added to deionized water and stirred at 800 rpm for 15 minutes until completely dissolved; talc powder, modified nano aerogel and ceramic far-infrared powder were added in sequence, the temperature was raised to 40 degrees Celsius, the speed was increased to 1200 rpm and dispersed for 30 minutes until the system had no obvious particles and the particle size was ≤5 micrometers, so as to achieve uniform dispersion of solid particles and avoid the heat insulation efficiency reduction caused by uneven dispersion in the existing technology; then water-based acrylic emulsion and propylene glycol methyl ether acetate were added and stirred at 600 rpm for 25 minutes until the system was uniform and without layering; finally, organosilicon defoamer and hydroxyethyl cellulose thickener were added and the viscosity was adjusted to 80 KU to obtain the base material.

[0025] (3) Composite molding: Using a low-speed mixer, hollow silica glass microspheres and multicolored particles are added to the base material and stirred at a low speed of 300 rpm for 15 minutes until uniform and free of agglomeration; let stand for 20 minutes to defoam until there are no obvious bubbles in the system, and obtain heat-insulating water-based multicolored exterior wall coating.

[0026] Example 2:

[0027] Raw material adjustment: 18 parts of nano-silica aerogel, 10 parts of ceramic far-infrared powder, and 7 parts of hollow silica glass microspheres are used to enhance the triple synergistic effect of barrier-radiation-reflection, so that the heat insulation efficiency can break through the upper limit of the existing technology; 20 parts of water-based acrylic emulsion and 18 parts of deionized water are used to adjust the proportion of heat insulation components to ensure system compatibility. The amount of other raw materials is completely consistent with that in Example 1 (the raw material specifications are the same as in Example 1).

[0028] Preparation steps adjusted: In the preparation of the base material, the dispersion time of the inorganic filler and the composite heat insulation component was extended to 40 minutes, and the dispersion was carried out until there were no obvious particles in the system and the particle size was ≤5 micrometers. The dispersion effect was optimized for the high-density heat insulation component. The stirring temperature in the composite molding stage was controlled at 25 degrees Celsius to reduce the negative impact of the system viscosity on the dispersion of the heat insulation filler. The remaining operation steps were completely consistent with those in Example 1.

[0029] Example 3:

[0030] Raw material adjustment: 15 parts of waterborne acrylic emulsion and 10 parts of waterborne polyurethane emulsion are used to overcome the performance shortcomings of single emulsions by utilizing the synergistic effect of the film-forming properties of acrylic emulsion and the weather resistance of polyurethane emulsion; the film-forming aids are 3 parts of propylene glycol methyl ether acetate and 2 parts of dodecyl alcohol ester, which are precisely adapted to the film-forming requirements of the compound emulsion. The amount of other raw materials is completely consistent with that in Example 2 (the raw material specifications are the same as in Example 1).

[0031] Preparation steps adjusted: In the preparation of the base material, two emulsions are added in stages. First, the aqueous acrylic emulsion is added and stirred at 600 rpm for 20 minutes until it is uniform. Then, the aqueous polyurethane emulsion is added and stirred for another 15 minutes until the system is uniform and without layering. This avoids the phase separation problem caused by direct mixing in the prior art. The remaining operation steps are completely consistent with those in Example 2.

[0032] Example 4:

[0033] Raw material ratio: completely consistent with Example 3 (raw material specifications are the same as in Example 1).

[0034] Preparation steps adjusted: (1) Modification treatment: A high-speed mechanical stirrer was used to increase the mixing temperature of nano-silica aerogel and silane coupling agent KH560 to 70 degrees Celsius, maintain the stirring speed at 500 rpm, and extend the stirring time to 90 minutes to enhance the modification effect, so that the surface modification rate of nano powder is ≥85%, which is far beyond the modification level of existing technologies; after the colorful particles are crushed, they are screened through a 100-mesh sieve, and the particle size is controlled to 0.3 mm to optimize the decorative effect and dispersion stability of the colored particles.

[0035] (2) Base material preparation: A high-speed disperser was used, and the dispersion speed was increased to 1500 rpm. The dispersion time of inorganic filler and heat insulation components was shortened to 25 minutes. The dispersion was carried out until there were no obvious particles in the system and the particle size was ≤5 micrometers. Through the synergistic optimization of speed and time, the dispersion efficiency was improved while avoiding excessive particle crushing. After adding the emulsion, the system was stirred at a low speed of 400 rpm for 30 minutes until the system was uniform and without layering. This ensured that the emulsion and the base material were fully integrated and reduced the generation of bubbles.

[0036] (3) Composite molding: A low-speed stirrer is used, and the material is added in steps. First, hollow silica glass microspheres are added to the base material and stirred for 10 minutes until uniform. Then, colorful particles are added and stirred for another 15 minutes until uniform and free of agglomeration, so as to avoid the mutual influence of components with different densities. The standing defoaming time is extended to 30 minutes until the system is free of obvious bubbles, which solves the problem of residual bubbles caused by simple stirring in the prior art. The remaining operation steps are completely consistent with those in Example 3.

[0037] Example 5:

[0038] Raw material adjustments: 15 parts nano-silica aerogel, 12 parts ceramic far-infrared powder, and 10 parts hollow silica glass microspheres were used to optimize the ratio of the triple insulation components to the optimal synergistic state; the thickener consisted of 0.8 parts hydroxyethyl cellulose and 1 part polyurethane associative thickener, utilizing the synergistic effect of the thixotropic properties of the cellulose thickener and the leveling properties of the polyurethane thickener to improve the construction performance; the amount of silane coupling agent KH560 was increased to 1.5 parts to further enhance the bonding force between the insulation filler and the film-forming system and extend the product's service life; the remaining raw material amounts were completely consistent with those in Example 4 (raw material specifications were the same as in Example 1).

[0039] Preparation steps: exactly the same as in Example 4.

[0040] Comparative Example 1: To mimic the shortcomings of the single heat insulation mechanism in existing technologies, the raw materials were adjusted: nano-silica aerogel and ceramic far-infrared powder were removed, and only 25 parts of hollow silica glass microspheres (particle size 50 micrometers, reflectivity 80%, bulk density 0.3 g per cubic centimeter) were retained. Only reflective heat insulation was achieved, without any synergistic effect. The amount of other raw materials was completely consistent with that in Example 1 (the raw material specifications were the same as in Example 1).

[0041] Preparation steps: exactly the same as in Example 1.

[0042] Comparative Example 2: To mimic the shortcomings of unmodified nanoparticles in existing technologies, the raw materials were adjusted: the nano-silica aerogel was not modified with silane coupling agents to retain the potential for agglomeration, while the amounts of the remaining raw materials were exactly the same as in Example 2 (the specifications of the raw materials were the same as in Example 1).

[0043] Preparation steps: The modification process is removed, and the unmodified nano-silica aerogel is directly added to the base material. The remaining operation steps are completely consistent with those in Example 2.

[0044] Comparative Example 3: To mimic the shortcomings of existing single emulsion combined with one-step dispersion process, the raw materials were adjusted: only 25 parts of water-based acrylic emulsion (50% solid content) were used, without any weather resistance optimization, and the amount of other raw materials was exactly the same as in Example 3 (the raw material specifications were the same as in Example 1).

[0045] Preparation steps: The base material is prepared by a one-step dispersion method. All solid raw materials are added to water at the same time and stirred for 40 minutes at 1000 rpm using a high-speed disperser to simulate the problem of uneven dispersion in the existing technology. The remaining operation steps are completely consistent with those in Example 3.

[0046] Comparative Example 4: To mitigate the shortcomings of a simple combination of single multicolor technology and single heat insulation technology, the raw materials were adjusted as follows: 18 parts of hydroxypropyl starch (viscosity 300 mPa·s), 5 parts of phthalocyanine blue (color content 95%), and 3 parts of glycerol (purity 99%) were directly mixed with 20 parts of hollow silica glass microspheres (particle size 50 micrometers, reflectivity 80%, bulk density 0.3 g / cm³). There was no nano-modification or emulsion compounding. The amounts of the remaining raw materials were completely consistent with those in Example 5 (the raw material specifications were the same as in Example 1).

[0047] Preparation steps: Using existing conventional technology, all raw materials are dispersed in one step. A high-speed disperser is used to stir at 900 rpm for 35 minutes. There is no stepwise compounding or low temperature control. The remaining operation steps are completely consistent with those in Example 5.

[0048] Performance testing and results analysis: Test standards and methods: (1) Thermal insulation performance: According to GB / T26744-2011, the thermal insulation coating performance test device for building exterior surface is used to simulate the solar radiation intensity of 500 watts per square meter and test the temperature difference between the substrate and the coating surface when the coating thickness is 200 micrometers; the thermal conductivity is tested according to GB / T10294-2008 using the steady-state heat flow method at a test temperature of 25 degrees Celsius.

[0049] (2) Weather resistance: In accordance with GB / T1865-2009, artificial accelerated aging test was carried out using a xenon lamp aging test chamber, with a cumulative irradiation of 1000 hours. After the test, the appearance of the coating was observed, and the color difference ΔE was measured using a colorimeter.

[0050] (3) Adhesion: According to GB / T9286-1998, the cross-cut test is performed using a cross-cut tester with a cross-cut spacing of 1 mm. After the cross-cut is performed, the coating is peeled off with adhesive tape, and the coating peeling is observed to determine the adhesion level.

[0051] (4) Water resistance: According to GB / T1733-1993, the coated test plate was immersed in deionized water at 25 degrees Celsius for 240 hours. After immersion, the coating was observed to see if it wrinkled or peeled off.

[0052] (5) Color stability: Store the paint sample at room temperature of 25 degrees Celsius for 6 months and observe regularly whether the color particles agglomerate or bleed.

[0053] (6) Low temperature stability: According to GB / T20624.1-2006, the coating sample was stored in a low temperature environment of -5 degrees Celsius for 72 hours, and then taken out and restored to room temperature to observe the coating condition.

[0054] The test results are shown in Table 1 below: Table 1:

[0055] Test Result Analysis: (1) In terms of thermal insulation performance, the temperature difference of Examples 1 to 5 gradually increased from 12.5 degrees Celsius to 18.2 degrees Celsius, and the thermal conductivity gradually decreased from 0.038 W / m Kelvin to 0.025 W / m Kelvin, which were significantly better than the comparative examples and the average level of the prior art. Comparative Example 1 only used a single hollow glass microsphere to achieve reflective thermal insulation, without synergistic effect, with a temperature difference of only 8.6 degrees Celsius and a thermal conductivity of 0.056 W / m Kelvin, proving the core role of the triple synergistic thermal insulation mechanism; Comparative Example 2 did not modify the nano aerogel, resulting in powder agglomeration, with a temperature difference of 11.2 degrees Celsius and a thermal conductivity of 0.043 W / m Kelvin, which was lower than that of Example 2, proving the necessity of nano powder modification.

[0056] (2) Regarding weather resistance and adhesion, after using emulsion compounding technology in Examples 3 to 5, the weather resistance color difference ΔE decreased from 1.8 to 0.8, and the adhesion improved from level 1 to level 0, which is better than Comparative Examples 3 and 4, which use a single emulsion. Comparative Example 3 uses a single water-based acrylic emulsion, with a weather resistance color difference ΔE of 2.3 and an adhesion level of 1, proving that the emulsion compounding technology can effectively solve the contradiction between the film-forming properties and weather resistance of a single emulsion; Comparative Example 4 is a simple combination of existing technologies, with a weather resistance color difference ΔE of 3.6 and an adhesion level of 2, further proving the synergistic advantages of emulsion compounding and process optimization in this invention.

[0057] (3) In terms of water resistance, color stability, and low-temperature stability, all embodiments showed excellent performance. Water resistance remained normal after 240 hours, color stability remained stable after 6 months, and low-temperature stability was normal. However, each comparative example showed different degrees of performance defects. Comparative example 1 showed slight wrinkling and delamination, comparative example 2 showed slight whitening and delamination, comparative example 3 showed partial agglomeration and slight delamination, and comparative example 4 showed local peeling, severe agglomeration, and severe delamination. All of these were inferior to the embodiments of the present invention.

[0058] In summary, this invention achieves excellent performance in all aspects of the product through the organic synergy of a triple synergistic thermal insulation mechanism, nanoparticle modification, emulsion compounding, and step-by-step process optimization. Each technical feature is indispensable, and the test results fully demonstrate the feasibility and superiority of the technical solution of this invention.

[0059] Compared with existing technologies and combinations thereof, the technical solution of this invention has outstanding substantive features and significant progress, specifically reflected in the following aspects: The core technological value of this invention lies in the organic synergy of its various technical features, rather than the simple superposition of existing technologies. Existing technologies have never simultaneously integrated the four core technical features: a triple synergistic heat insulation mechanism, nanopowder modification, emulsion compounding, and stepwise process optimization. A simple combination of a single multi-color technology and a single heat insulation technology, as shown in Comparative Example 4, suffers from powder agglomeration due to the lack of nano-modification, resulting in a thermal conductivity of 0.053 W / m Kelvin; poor weather resistance due to the lack of emulsion compounding, with a color difference ΔE of 3.6; and severe agglomeration of colored particles due to the lack of stepwise processing. The overall performance is far inferior to that of this invention. The four technical features of this invention form a mutually supportive organic whole. Nano-modification solves the compatibility problem between the triple heat insulation components and the film-forming system; emulsion compounding provides a stable film-forming environment for the heat insulation components; and the stepwise process ensures the integrity of the colored particles and the dispersibility of the heat insulation filler. The synergy of these four features achieves a technical effect superior to the superposition of individual technologies, rather than simply a functional stacking of existing technologies.

[0060] This invention precisely addresses the inherent contradictions and performance bottlenecks of existing technologies. For example, it addresses the contradiction between thermal insulation efficiency and decorative properties, where existing technologies cannot simultaneously achieve a temperature difference ≥15 degrees Celsius and color particle stability for 6 months. In this invention, the temperature difference in Examples 2 and above is ≥15.3 degrees Celsius, and the color particles remain stable for 6 months at room temperature. It also addresses the contradiction between nanopowder dispersibility and thermal insulation efficiency, where existing technologies use unmodified nanopowder with a dispersion particle size ≥10 micrometers. This invention, after modification, achieves a dispersion particle size ≤5 micrometers, improving thermal insulation efficiency by over 40%. Furthermore, it addresses the contradiction between film-forming properties and weather resistance, where existing single-emulsion technologies either have poor film-forming properties or insufficient weather resistance. This invention, through emulsion compounding, achieves synergistic optimization of adhesion grade 0 and color difference ΔE 0.8. Finally, it addresses the contradiction between process adaptability and performance stability, where existing technologies use fixed parameters that only adapt to specific equipment. This invention, through synergistic optimization of process parameters, ensures stable performance over a wider operating range. These breakthroughs cannot be achieved through conventional improvements to existing technologies.

[0061] The technical solution of this invention achieves a significant improvement in the core performance of the product. Compared with the average level of existing technologies, the thermal conductivity is reduced by 51% (0.025 vs. 0.051), the temperature difference is increased by 91% (18.2 vs. 9.5), the weather resistance color difference ΔE is reduced by 76% (0.8 vs. 3.3), the adhesion is improved by 1 level (0 vs. 2), and the stability of multicolor is extended by more than 2 times.

[0062] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention.

Claims

1. A heat-insulating, water-based, multi-colored exterior wall coating, characterized in that, It is made from the following raw materials in parts by weight: 15-25 parts of aqueous film-forming emulsion, 10-18 parts of nano-silica aerogel, 6-12 parts of ceramic far-infrared powder, 7-10 parts of hollow silica glass microspheres, 18 parts of hydroxypropyl starch, 3 parts of glycerol, 5 parts of phthalocyanine blue, 1.5 parts of sodium polycarboxylate dispersant, 0.8 parts of fatty acid polyoxyethylene ether wetting agent, 0.6 parts of organosilicon defoamer, 0.8-1.8 parts of thickener, 0.8-1.5 parts of silane coupling agent KH560, 3-5 parts of film-forming aid, 12 parts of talc, and 18-20 parts of deionized water; wherein the aqueous film-forming emulsion is an aqueous acrylate emulsion, or a compound of aqueous acrylate emulsion and aqueous polyurethane emulsion.

2. The thermal insulation water-based multicolor exterior wall coating according to claim 1, characterized in that, The thickener is hydroxyethyl cellulose, or a compound of hydroxyethyl cellulose and a polyurethane-associated thickener; the film-forming aid is propylene glycol methyl ether acetate, or a compound of propylene glycol methyl ether acetate and dodecyl ester.

3. A method for preparing a heat-insulating, water-based, multi-colored exterior wall coating as described in claim 1, characterized in that, Includes the following steps: (1) Modification treatment: Nano-silica aerogel was mixed with silane coupling agent KH560 using a high-speed mechanical stirrer and stirred at a speed of 500 rpm to obtain modified nano-aerogel; Hydroxypropyl starch, glycerol and phthalocyanine blue were mixed using a twin-screw extruder and plasticized and extruded at 120 degrees Celsius and 80 rpm. After extrusion, the mixture was crushed and sieved by a high-speed pulverizer to obtain colorful particles; (2) Base material preparation: Sodium polycarboxylate dispersant and fatty acid polyoxyethylene ether wetting agent were added to deionized water using a high-speed disperser and stirred at 800 rpm until completely dissolved. Talc powder, modified nano aerogel and ceramic far-infrared powder were added in sequence and the temperature was raised to 40 degrees Celsius for dispersion treatment. Then, aqueous film-forming emulsion and film-forming aid were added and stirred at 600 rpm until the system was uniform and without layering. Finally, organosilicon defoamer and thickener were added to adjust the viscosity to 80 KU to obtain the base material. (3) Composite molding: Hollow silica glass microspheres and multicolored particles are added to the base material using a low-speed stirrer. The mixture is stirred at a low speed of 300 rpm until it is uniform and free of agglomeration. The mixture is then allowed to stand to defoam until there are no obvious bubbles in the system, thus obtaining the heat-insulating water-based multicolored exterior wall coating.

4. The preparation method according to claim 3, characterized in that, In step (1), the mixing temperature of the nano-silica aerogel and the silane coupling agent KH560 is 60 to 70 degrees Celsius, and the mixing time is 60 to 90 minutes.

5. The preparation method according to claim 3, characterized in that, In step (1), the colorful particles are sieved through a 100 to 200 mesh sieve to obtain colorful particles of the corresponding particle size.

6. The preparation method according to claim 3, characterized in that, In step (2), the dispersion speed of talc powder, modified nano aerogel and ceramic far-infrared powder is 1200 to 1500 rpm and the dispersion time is 25 to 40 minutes, until the system has no obvious particles and the particle size is ≤5 micrometers.

7. The preparation method according to claim 3, characterized in that, In step (2), when the aqueous film-forming emulsion is a mixture of aqueous acrylic emulsion and aqueous polyurethane emulsion, the aqueous acrylic emulsion is added first and stirred at 600 rpm for 20 minutes, and then the aqueous polyurethane emulsion is added and stirred for another 15 minutes until the system is uniform and without layering.

8. The preparation method according to claim 3, characterized in that, In step (3), a step-by-step feeding method is adopted. First, hollow silica glass microspheres are added to the base material and stirred for 10 minutes. Then, colorful particles are added and stirred for another 15 minutes until uniform and free of agglomeration.

9. The preparation method according to claim 3, characterized in that, In step (3), the time for letting the foam stand is 20 to 30 minutes.

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