A reflective heat-insulating stone-like energy-saving coating and its preparation method and application

Abstract

The present invention provides a reflective and heat-insulating stone-like energy-saving paint and a preparation method and application thereof, which belong to the field of architectural paints. By introducing an inorganic phase-change filler and a polymer modifier to jointly modify hollow glass microspheres, the mechanical properties and durability of the paint can be improved while improving the reflective and heat-insulating properties of the paint; by modifying the silicone resin with a crosslinking agent, a three-dimensional network structure connected by chemical bonds can be formed between the silicone resin molecules, thereby enhancing the stability and heat resistance of the paint; and the addition of white pigments can increase the reflectivity of the paint, reduce the heat absorption of the paint, and improve its heat-insulating properties; chemical etching modification of silica sand not only improves its stability and durability, but also enhances the reflective performance of sunlight, thereby improving the reflective and heat-insulating properties of the paint; and at the same time, more active sites are brought to its surface, thereby improving the overall performance of the paint. The reflective and heat-insulating stone-like energy-saving paint provided by the present invention has good application prospects in the construction industry.

Description

Technical Field

[0001] The invention belongs to the technical field of building coatings and relates to a reflective heat-insulating stone-like energy-saving coating and a preparation method and application thereof. Background Art

[0002] Reflective and heat-insulating stone-like energy-saving paint is an advanced architectural paint designed to improve the energy efficiency and comfort of buildings. This type of paint combines elegant appearance with excellent functionality. When the outdoor temperature is high in summer, it can effectively reflect solar radiation and reduce the heat absorption of the building, thereby lowering the indoor temperature, reducing the burden of air conditioning, and achieving energy conservation; while when the temperature is low, it can prevent indoor heat from transferring to the outdoors, thereby achieving a thermal insulation effect.

[0003] However, many traditional stone-like energy-saving coatings have insufficient reflectivity under high temperatures or strong sunlight, causing the building surface to absorb too much heat. This heat accumulation not only increases the internal temperature of the building, but also increases the burden on the air-conditioning system, which in turn leads to increased energy consumption. In addition, insufficient reflectivity may also lead to thermal aging of building materials and shorten their service life; existing coatings also perform poorly in terms of thermal insulation performance. The thermal insulation effect of traditional coatings often depends on their thickness and structural design, which are limited by construction technology, material quality and environmental conditions in actual applications. This dependence makes it difficult to maintain consistent thermal insulation effects, especially in extreme weather conditions, where thermal insulation performance can be significantly reduced, affecting indoor comfort.

[0004] As climate change intensifies, the heat load faced by buildings continues to increase. The reflective and thermal insulation properties of traditional stone-like energy-saving coatings are difficult to meet the needs of modern buildings for energy saving and environmental adaptability. Therefore, there is an urgent need for a new type of reflective thermal insulation coating to effectively enhance its reflective and thermal insulation properties and meet the construction industry's requirements for sustainable development. Summary of the invention

[0005] In view of the above problems, the purpose of the present invention is to provide a reflective and heat-insulating stone-like energy-saving paint and its preparation method and application. By modifying hollow glass microspheres with inorganic phase change fillers and polymer modifiers, the mechanical properties and durability of the paint can be improved while improving the reflective and heat-insulating properties of the paint; by modifying the silicone resin with a crosslinking agent, a three-dimensional network structure connected by chemical bonds can be formed between the silicone resin molecules, thereby enhancing the stability and heat resistance of the paint; and the addition of white pigments can increase the reflectivity of the paint, reduce the heat absorption of the paint, and thus improve its heat-insulating properties; chemical etching modification of silica sand not only improves its stability and durability, but also enhances the reflection performance of sunlight, thereby improving the reflective and heat-insulating properties of the paint; and at the same time, it also brings more active sites to its surface, thereby improving the overall performance of the paint.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a method for preparing a reflective heat-insulating stone-like energy-saving paint, the method for preparing the reflective heat-insulating stone-like energy-saving paint comprising:

[0008] S1: dispersing an inorganic phase change filler in deionized water, ultrasonically treating the mixture to obtain an inorganic phase change filler suspension; adding hollow glass microspheres to the inorganic phase change filler suspension to obtain a mixed solution A, stirring the mixture, filtering the mixture to obtain first modified hollow glass microspheres, and drying the mixture to obtain filler-embedded hollow glass microspheres; adding a polymer modifier to deionized water to obtain a polymer modifier solution, adding the filler-embedded hollow glass microspheres to obtain a mixed solution B, stirring the mixture to react, filtering the mixture to obtain second modified hollow glass microspheres, and curing the mixture to obtain modified hollow glass microspheres;

[0009] S2: dissolving a crosslinking agent in deionized water to obtain a crosslinking agent solution; stirring the silicone resin emulsion at room temperature, and while stirring, dropping the crosslinking agent solution into the silicone resin emulsion to obtain a crosslinked modified silicone resin emulsion; dispersing a white pigment in deionized water, ultrasonically dispersing to obtain a white pigment dispersion, adding the white pigment dispersion to the crosslinked modified silicone resin emulsion to obtain a mixed solution C, reacting at a constant temperature to obtain a mixed solution D, and cooling to room temperature to obtain a modified silicone resin emulsion;

[0010] S3: Soak silica sand in a hydrofluoric acid solution, wash it after soaking to obtain modified silica sand, and obtain chemically etched silica sand after drying; add chemically etched silica sand, high-reflective powder, and low-absorption pigment to a super-weather-resistant resin solution to obtain a mixed solution E, put the mixed solution E into an oven for curing to obtain coarse reflective insulating sand, and obtain homemade reflective insulating sand by screening.

[0011] S4: Add a thickener, a dispersant, and propylene glycol to deionized water in sequence, stir to obtain a base solution, and then add homemade reflective heat-insulating sand, modified hollow glass microspheres, and modified silicone resin emulsion in sequence, stir to obtain a reflective heat-insulating stone-like energy-saving coating.

[0012] As a preferred technical solution of the present invention, in step S1, when the inorganic phase change filler is sodium sulfate hydrate, the mass ratio of the inorganic phase change filler to deionized water in the inorganic phase change filler suspension is (0.3-0.4):1, for example, it can be 0.3:1, 0.31:1, 0.32:1, 0.33:1, 0.34:1, 0.35:1, 0.36:1, 0.37:1, 0.38:1, 0.39:1 or 0.4:1, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0013] In some optional examples, when the inorganic phase change filler is calcium chloride hydrate, the mass ratio of the inorganic phase change filler to deionized water in the inorganic phase change filler suspension is (0.8-0.85):1, for example, it can be 0.8:1, 0.81:1, 0.82:1, 0.83:1, 0.84:1 or 0.85:1, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0014] In some optional examples, the power of ultrasonic treatment of the inorganic phase change filler dispersed in deionized water is 200-300 W, for example, it can be 200 W, 210 W, 220 W, 230 W, 240 W, 250 W, 260 W, 270 W, 280 W, 290 W or 300 W, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0015] In some optional examples, the time for ultrasonic treatment of the inorganic phase change filler dispersed in deionized water is 10-30 min, for example, it can be 10 min, 12 min, 14 min, 16 min, 18 min, 20 min, 22 min, 24 min, 26 min, 28 min or 30 min, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0016] In some optional examples, the mass ratio of the hollow glass microspheres to the inorganic phase change filler is 1:(0.5-2), for example, it can be 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1.0, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9 or 1:2, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0017] In some optional examples, the stirring speed of the mixed solution A is 300-500 rpm, for example, it can be 300 rpm, 320 rpm, 340 rpm, 360 rpm, 380 rpm, 400 rpm, 420 rpm, 440 rpm, 460 rpm, 480 rpm or 500 rpm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0018] In some optional examples, the stirring time of the mixed solution A is 1-2h, for example, it can be 1.0h, 1.1h, 1.2h, 1.3h, 1.4h, 1.5h, 1.6h, 1.7h, 1.8h, 1.9h or 2.0h, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0019] In some optional examples, the drying temperature of the first modified hollow glass microspheres is 50-60°C, for example, it can be 50°C, 51°C, 52°C, 53°C, 54°C, 55°C, 56°C, 57°C, 58°C, 59°C or 60°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0020] In some optional examples, the drying time of the first modified hollow glass microspheres is 5-10 hours, for example, 5 hours, 5.5 hours, 6 hours, 6.5 hours, 7 hours, 7.5 hours, 8 hours, 8.5 hours, 9 hours, 9.5 hours or 10 hours, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0021] In some optional examples, the mass fraction of the polymer modifier in the polymer modifier solution is 5-10%, for example, it can be 5.0%, 5.5%, 6.0%, 6.5%, 7.0%, 7.5%, 8.0%, 8.5%, 9.0%, 9.5% or 10.0%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0022] In some optional examples, the mass ratio of the polymer modifier to the filler-embedded hollow glass microspheres is 1:(1-3), for example, it can be 1:1.0, 1:1.2, 1:1.4, 1:1.6, 1:1.8, 1:2.0, 1:2.2, 1:2.4, 1:2.6, 1:2.8 or 1:3.0, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0023] In some optional examples, the stirring reaction speed of the mixed solution B is 200-300 rpm, for example, it can be 200 rpm, 210 rpm, 220 rpm, 230 rpm, 240 rpm, 250 rpm, 260 rpm, 270 rpm, 280 rpm, 290 rpm or 300 rpm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0024] In some optional examples, the temperature of the stirring reaction of the mixed solution B is 35-45°C, for example, it can be 35°C, 36°C, 37°C, 38°C, 39°C, 40°C, 41°C, 42°C, 43°C, 44°C or 45°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0025] In some optional examples, the stirring reaction time of the mixed solution B is 3-4h, for example, it can be 3.0h, 3.1h, 3.2h, 3.3h, 3.4h, 3.5h, 3.6h, 3.7h, 3.8h, 3.9h or 4.0h, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0026] In some optional examples, the curing temperature of the second modified hollow glass microspheres is 70-80°C, for example, 70°C, 71°C, 72°C, 73°C, 74°C, 75°C, 76°C, 77°C, 78°C, 79°C or 80°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0027] In some optional examples, the curing time of the second modified hollow glass microspheres is 4-6 hours, for example, it can be 4.0 hours, 4.2 hours, 4.4 hours, 4.6 hours, 4.8 hours, 5.0 hours, 5.2 hours, 5.4 hours, 5.6 hours, 5.8 hours or 6.0 hours, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0028] As a preferred technical solution of the present invention, in step S2, the mass fraction of the crosslinker in the crosslinker solution is 1-2%, for example, it can be 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9% or 2.0%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0029] In some optional examples, the mass ratio of the crosslinking agent to the silicone resin is 1:(5-10), for example, it can be 1:5.0, 1:5.5, 1:6.0, 1:6.5, 1:7.0, 1:7.5, 1:8.0, 1:8.5, 1:9.0, 1:9.5 or 1:10.0, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0030] In some optional examples, the stirring speed when the silicone resin emulsion and the crosslinker solution are mixed is 200-300 rpm, for example, it can be 200 rpm, 210 rpm, 220 rpm, 230 rpm, 240 rpm, 250 rpm, 260 rpm, 270 rpm, 280 rpm, 290 rpm or 300 rpm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0031] In some optional examples, the stirring time when the silicone resin emulsion and the crosslinker solution are mixed is 30-40 minutes, for example, it can be 30 minutes, 31 minutes, 32 minutes, 33 minutes, 34 minutes, 35 minutes, 36 minutes, 37 minutes, 38 minutes, 39 minutes or 40 minutes, but it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0032] In some optional examples, the mass fraction of the white pigment in the white pigment dispersion is 10-20%, for example, it can be 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19% or 20%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0033] In some optional examples, the mass ratio of the white pigment to the cross-linked modified silicone resin in the mixed solution C is 1:(2-5), for example, it can be 1:2.0, 1:2.5, 1:3.0, 1:3.5, 1:4.0, 1:4.5 or 1:5.0, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0034] In some optional examples, the temperature of the isothermal reaction of the mixed solution C is 70-80°C, for example, it can be 70°C, 71°C, 72°C, 73°C, 74°C, 75°C, 76°C, 77°C, 78°C, 79°C or 80°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0035] In some optional examples, the isothermal reaction time of the mixed solution C is 1-2h, for example, it can be 1.0h, 1.1h, 1.2h, 1.3h, 1.4h, 1.5h, 1.6h, 1.7h, 1.8h, 1.9h or 2.0h, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0036] As a preferred technical solution of the present invention, in step S3, the mass fraction of hydrofluoric acid in the hydrofluoric acid solution is 5-10%, for example, it can be 5.0%, 5.5%, 6.0%, 6.5%, 7.0%, 7.5%, 8.0%, 8.5%, 9.0%, 9.5% or 10.0%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0037] In some optional examples, the mass ratio of hydrofluoric acid to silica sand is 1:(5-10), for example, it can be 1:5, 1:5.5, 1:6, 1:6.5, 1:7, 1:7.5, 1:8, 1:8.5, 1:9, 1:9.5 or 1:10, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0038] In some optional examples, the silica sand is immersed in the hydrofluoric acid solution for 10-30 minutes, for example, 10 minutes, 12 minutes, 14 minutes, 16 minutes, 18 minutes, 20 minutes, 22 minutes, 24 minutes, 26 minutes, 28 minutes or 30 minutes, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0039] In some optional examples, the drying temperature of the modified silica sand is 60-70°C, for example, it can be 60°C, 61°C, 62°C, 63°C, 64°C, 65°C, 66°C, 67°C, 68°C, 69°C or 70°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0040] In some optional examples, the drying time of the modified silica sand is 2-4 hours, for example, it can be 2.0 hours, 2.2 hours, 2.4 hours, 2.6 hours, 2.8 hours, 3.0 hours, 3.2 hours, 3.4 hours, 3.6 hours, 3.8 hours or 4.0 hours, but it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0041] As a preferred technical solution of the present invention, in S3, the mass fraction of the super weather resistant resin in the super weather resistant resin solution is 5-10%, for example, it can be 5.0%, 5.5%, 6.0%, 6.5%, 7.0%, 7.5%, 8.0%, 8.5%, 9.0%, 9.5% or 10.0%, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0042] In some optional examples, the curing temperature of the mixed solution E in the oven is 50-60°C, for example, it can be 50°C, 51°C, 52°C, 53°C, 54°C, 55°C, 56°C, 57°C, 58°C, 59°C or 60°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0043] In some optional examples, the curing time of the mixed solution E in the oven is 4-6 hours, for example, it can be 4.0 hours, 4.2 hours, 4.4 hours, 4.6 hours, 4.8 hours, 5.0 hours, 5.2 hours, 5.4 hours, 5.6 hours, 5.8 hours or 6.0 hours, but it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0044] In some optional instances, the particle size of the homemade reflective insulating sand is 100-500 μm, for example, it can be 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm or 500 μm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0045] As a preferred technical solution of the present invention, the homemade reflective insulating sand includes the following components in parts by weight: 95-98 parts of chemically etched silica sand, 2-3 parts of super weather-resistant resin, 0.2-0.5 parts of high-reflective powder, and 0.2-0.5 parts of low-absorption pigment.

[0046] In some optional examples, the silica sand is 95-98 parts, for example, it can be 95.0 parts, 95.2 parts, 95.4 parts, 95.6 parts, 95.8 parts, 96.0 parts, 96.2 parts, 96.4 parts, 96.6 parts, 96.8 parts, 97.0 parts, 97.2 parts, 97.4 parts, 97.6 parts, 97.8 parts or 98.0 parts, but it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0047] In some optional examples, the super weather resistant resin is 2-3 parts, for example, it can be 2.0 parts, 2.1 parts, 2.2 parts, 2.3 parts, 2.4 parts, 2.5 parts, 2.6 parts, 2.7 parts, 2.8 parts, 2.9 parts or 3.0 parts, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0048] In some optional examples, the high reflective powder is 0.2-0.5 parts, for example, it can be 0.2 parts, 0.22 parts, 0.24 parts, 0.26 parts, 0.28 parts, 0.3 parts, 0.32 parts, 0.34 parts, 0.36 parts, 0.38 parts, 0.4 parts, 0.42 parts, 0.44 parts, 0.46 parts, 0.48 parts or 0.5 parts, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0049] In some optional examples, the low absorption pigment is 0.2-0.5 parts, for example, it can be 0.2 parts, 0.22 parts, 0.24 parts, 0.26 parts, 0.28 parts, 0.3 parts, 0.32 parts, 0.34 parts, 0.36 parts, 0.38 parts, 0.4 parts, 0.42 parts, 0.44 parts, 0.46 parts, 0.48 parts or 0.5 parts, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0050] As a preferred technical solution of the present invention, the reflective heat-insulating stone-like energy-saving paint includes the following components in parts by mass: 20-30 parts of modified silicone resin emulsion; 5-10 parts of modified hollow glass microspheres; 40-60 parts of homemade reflective heat-insulating sand; 1-3 parts of thickener; 0.5-1 part of dispersant; 1-2 parts of propylene glycol; 30-40 parts of deionized water; wherein the thickener is carboxymethyl cellulose or hydroxypropyl cellulose; and the dispersant is sodium stearate or polyethyleneimine.

[0051] In some optional examples, the modified silicone resin emulsion is 20-30 parts, for example, it can be 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, 26 parts, 27 parts, 28 parts, 29 parts or 30 parts, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0052] In some optional examples, the modified hollow glass microspheres are 5-10 parts, for example, 5.0 parts, 5.5 parts, 6.0 parts, 6.5 parts, 7.0 parts, 7.5 parts, 8.0 parts, 8.5 parts, 9.0 parts, 9.5 parts or 10.0 parts, but are not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0053] In some optional instances, the homemade reflective insulating sand is 40-60 parts, for example, it can be 40 parts, 42 parts, 44 parts, 46 parts, 48 ​​parts, 50 parts, 52 parts, 54 parts, 56 parts, 58 parts or 60 parts, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0054] In some optional examples, the thickener is 1-3 parts, for example, it can be 1.0 parts, 1.2 parts, 1.4 parts, 1.6 parts, 1.8 parts, 2.0 parts, 2.2 parts, 2.4 parts, 2.6 parts, 2.8 parts or 3.0 parts, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0055] In some optional examples, the dispersant is 0.5-1 part, for example, it can be 0.5 part, 0.55 part, 0.6 part, 0.65 part, 0.7 part, 0.75 part, 0.8 part, 0.85 part, 0.9 part, 0.95 part or 1.0 part, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0056] In some optional examples, the propylene glycol is 1-2 parts, for example, it can be 1.0 parts, 1.1 parts, 1.2 parts, 1.3 parts, 1.4 parts, 1.5 parts, 1.6 parts, 1.7 parts, 1.8 parts, 1.9 parts or 2.0 parts, but it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0057] In some optional examples, the deionized water is 30-40 parts, for example, it can be 30 parts, 31 parts, 32 parts, 33 parts, 34 parts, 35 parts, 36 parts, 37 parts, 38 parts, 39 parts or 40 parts, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0058] In the second aspect, the present invention provides a reflective heat-insulating imitation stone energy-saving paint, which comprises a modified silicone resin emulsion, a modified hollow glass microsphere, a self-made reflective heat-insulating sand, a thickener, a dispersant, propylene glycol and deionized water. Among them, the hollow glass microspheres are modified by an inorganic phase change filler and a polymer modifier, which can improve the mechanical properties and durability of the paint while improving the reflective and heat-insulating properties of the paint; the silicone resin is modified by a cross-linking agent to form a three-dimensional network structure connected by chemical bonds between silicone resin molecules, thereby enhancing the stability and heat resistance of the paint; and the addition of white pigment can improve the reflectivity of the paint, reduce the heat absorption of the paint, and thus improve its heat-insulating properties; chemical etching modification of silica sand not only improves its stability and durability, but also enhances the reflective performance of sunlight, thereby improving the reflective heat-insulating properties of the paint; and at the same time, more active sites are brought to its surface, thereby improving the overall performance of the paint.

[0059] The present invention modifies hollow glass microspheres by introducing inorganic phase change fillers. The smooth surface and specific optical properties of hollow glass microspheres enable them to effectively reflect solar radiation, especially visible light and near-infrared light, thereby reducing heat absorption; and due to its gas-filled characteristics, hollow glass microspheres can form a heat-insulating layer in the coating to prevent heat conduction, thereby improving the heat-insulating effect of the coating. Compared with air, inorganic phase change fillers can absorb or release a large amount of heat during the phase change process and have a higher heat capacity. This enables them to effectively regulate temperature changes and provide a more lasting heat-insulating effect; secondly, the phase change between solid and liquid of inorganic phase change fillers can quickly absorb or release heat when the temperature reaches a certain value, and can actively regulate the ambient temperature; inorganic phase change fillers can undergo phase changes multiple times without failure, and continue to provide thermal management functions, while the air layer may gradually lose its heat-insulating effect due to flow or heat conduction. That is, the addition of inorganic phase change fillers helps to improve the thermal stability of the coating and reduce the risk of performance degradation of the coating at high temperatures.

[0060] The inorganic phase change filler selected by the present invention is sodium sulfate hydrate or calcium chloride hydrate. Sodium sulfate hydrate and calcium chloride hydrate have high latent heat of phase change, can store and release a large amount of heat energy during the phase change process, improve the thermal management performance of the coating, and make it perform well in an environment with large temperature fluctuations; secondly, sodium sulfate hydrate and calcium chloride hydrate have good stability, which increases the service life of the coating; and the cost of these two phase change fillers is relatively low, suitable for large-scale production and application, and reduces the overall cost of the product.

[0061] The present invention modifies hollow glass microspheres by introducing a polymer modifier. The polymer modifier can improve the dispersibility of the hollow glass microspheres in the coating matrix, ensure that the hollow glass microspheres are evenly distributed, thereby avoiding precipitation and aggregation; at the same time, the addition of the polymer modifier can increase the toughness and flexibility of the coating, improve its wear resistance and weather resistance, and reduce cracks and peeling caused by environmental changes.

[0062] The polymer modifier selected by the present invention is polyurethane, polyvinyl alcohol or polypropylene alcohol. Polyurethane has good adhesion and can form a stable interface with hollow glass microspheres, thereby improving its dispersibility and stability in the coating. Polyvinyl alcohol and polypropylene alcohol can also provide good adhesion and ensure uniform distribution of fillers; polyurethane has good stability at high temperatures and can maintain performance in high temperature applications, and polyvinyl alcohol and polypropylene alcohol have relatively high thermal stability, so that the coating can be applied to a variety of environmental conditions.

[0063] The present invention defines the mass fraction of the modified hollow glass microspheres as 5-10 parts. The modified hollow glass microspheres obtained by jointly modifying with inorganic phase change fillers and polymer modifiers can improve the reflection and heat insulation performance of the coating while improving the mechanical properties and durability of the coating. However, when the content of the modified hollow glass microspheres in the coating is too high, it may cause the overall structure of the coating to become loose, thereby reducing the mechanical strength and adhesion of the coating, and at the same time may cause uneven reflection performance. If the content is too low, the heat insulation and reflection effects may not be fully exerted, affecting the overall thermal performance of the coating.

[0064] The present invention modifies the silicone resin with a crosslinking agent and a white pigment. The crosslinking agent reacts with the active groups of the silicone resin to form a three-dimensional network structure, and the crosslinked structure can improve the heat distortion temperature and heat resistance of the silicone resin, which helps the coating to maintain its performance in a high-temperature environment; and after crosslinking, the mechanical properties of the silicone resin will be improved, making it more durable during use. That is, the crosslinking reaction will increase the crosslinking degree of the silicone resin, causing chemical bond connections to form between the silicone resin molecules, thereby enhancing the stability and heat resistance of the coating.

[0065] The crosslinking agent selected in the present invention is formaldehyde or glutaraldehyde. Both formaldehyde and glutaraldehyde are highly active aldehyde compounds that can react with the nucleophilic groups of the silicone resin, thereby effectively achieving crosslinking. The crosslinking reaction produces a stable three-dimensional network structure, thereby enhancing the heat resistance of the resin. Formaldehyde and glutaraldehyde do not require extreme conditions during the reaction, thereby reducing the energy consumption and operation difficulty of the reaction.

[0066] The introduced white pigment has good light scattering and reflection properties and can effectively reflect infrared light and visible light in sunlight. The addition of the white pigment can increase the reflectivity of the coating, reduce the heat absorption of the coating, and thus improve its heat insulation performance; and by improving the reflection performance, the surface temperature of the coating will be effectively reduced, thereby reducing the heat load on the substrate, and at the same time the weather resistance and aging resistance of the coating are improved.

[0067] The white pigment selected in the present invention is titanium dioxide or aluminum hydroxide. Titanium dioxide is one of the commonly used white pigments and has excellent covering power, which can effectively cover the surface of the substrate, making the coating have a stronger shielding effect. In addition, titanium dioxide has good light scattering properties, which can enhance the reflection performance of the coating and improve the heat insulation effect of the coating; aluminum hydroxide can provide a good diffuse reflection effect, making the coating have a good optical effect and will not cause excessive gloss or reflection, which is suitable for stone-like coatings; at the same time, it can release moisture during heating and has good flame retardant properties, which helps the thermal stability and safety of the coating.

[0068] The present invention limits the mass fraction of the modified silicone resin to 20-30 parts. When the content of the modified silicone resin is too high, the viscosity of the coating may increase, making it difficult to apply, and may affect the reflective performance, causing uneven pigment dispersion and reducing the overall light reflectivity. If the content is too low, the reinforcing effect of the crosslinking agent and the white pigment may not be fully exerted, resulting in a decrease in the thermal insulation performance of the coating and affecting the weather resistance and mechanical strength of the coating.

[0069] The present invention modifies silica sand by chemical etching. Chemical etching can enhance the roughness of the surface of silica sand, thereby increasing its specific surface area. This rough structure helps to enhance the adhesion between the coating and the substrate, and improve the stability and durability of the coating; secondly, the surface of the etched silica sand has more microscopic depressions and protrusions, which can enhance the scattering effect of light, thereby improving the reflective performance of the silica sand, making it more effectively reflect sunlight, thereby enhancing the heat insulation effect of the coating; at the same time, the chemical etching process will change the surface chemical properties of the silica sand, so that its surface may have more active sites. These active sites can react chemically with other components, enhance the compatibility between different components, and then improve the overall performance of the coating; after improving the surface properties of silica sand by chemical etching, the overall weather resistance, wear resistance and chemical corrosion resistance of the coating may be improved, thereby enhancing its service life under various environmental conditions.

[0070] The super weather-resistant resin selected in the present invention is methyl silicone resin or polytetrafluoroethylene resin. Methyl silicone resin and polytetrafluoroethylene have excellent high temperature resistance and can remain stable at extreme temperatures; at the same time, methyl silicone resin and polytetrafluoroethylene resin can maintain strong chemical stability in complex environments and will not fail in some acidic and alkaline environments; in addition, methyl silicone resin and polytetrafluoroethylene resin have good weather resistance and can effectively extend the service life of the coating.

[0071] The high-reflective powder selected in the present invention is aluminum powder or aluminum silicate. Aluminum powder has a high light reflectivity in the visible light and near-infrared range, and aluminum silicate improves the heat insulation effect by scattering light and enhancing diffuse reflection. Both can provide good heat insulation; secondly, aluminum silicate and aluminum powder both have excellent high temperature resistance and can be applied to a variety of high temperature environments.

[0072] The low-absorption pigment selected in the present invention is titanium dioxide or zinc oxide. Titanium dioxide and zinc oxide have high reflectivity, especially in the visible light, ultraviolet light and near-infrared light regions. They can effectively reflect the heat in sunlight, achieve good heat insulation effect, and can more effectively reduce heat accumulation; titanium dioxide and zinc oxide have low heat absorption in a wide range of the reflection spectrum (especially ultraviolet light and near-infrared light), which can prevent the surface temperature of the coating from rising and enhance the heat insulation performance.

[0073] In a third aspect, the present invention provides the use of a reflective, heat-insulating, stone-like energy-saving paint obtained by the above-mentioned preparation method in the decoration of building exterior walls.

[0074] Compared with the prior art, the present invention has the following beneficial effects:

[0075] (1) The present invention modifies hollow glass microspheres by using inorganic phase change fillers and polymer modifiers. Inorganic phase change fillers can absorb or release a large amount of heat during the phase change process and have a higher heat capacity. This enables them to effectively regulate temperature changes and provide a more lasting thermal insulation effect. At the same time, they can actively regulate the ambient temperature without failure when the phase change temperature value is reached; polymer modifiers can improve the dispersibility of hollow glass microspheres in the coating matrix, ensuring that the hollow glass microspheres are evenly distributed, thereby avoiding precipitation and aggregation;

[0076] (2) The present invention modifies the silicone resin by a crosslinking agent, so that the silicone resin molecules form a three-dimensional network structure connected by chemical bonds, thereby enhancing the stability and heat resistance of the coating; and the addition of white pigment can increase the reflectivity of the coating, reduce the heat absorption of the coating, and thus improve its thermal insulation performance; and by improving the reflective performance, the surface temperature of the coating will be effectively reduced, thereby reducing the heat load on the substrate, and at the same time, the weather resistance and aging resistance of the coating will be improved;

[0077] (3) The present invention modifies silica sand by chemical etching. Chemical etching can enhance the roughness of the silica sand surface, thereby increasing its specific surface area; secondly, the etched silica sand surface has more microscopic depressions and protrusions, which can improve the reflective properties of the silica sand, thereby enhancing the thermal insulation effect of the coating; at the same time, the chemical etching process will change the surface chemical properties of the silica sand, so that its surface may have more active sites. This enhances the compatibility between different components, thereby improving the overall performance of the coating. BRIEF DESCRIPTION OF THE DRAWINGS

[0078] Figure 1 A flow chart of a method for preparing a reflective heat-insulating stone-like energy-saving coating provided in Example 1 of the present invention;

[0079] Figure 2 This is a SEM image of the hollow glass microspheres embedded with fillers provided in Example 1 of the present invention;

[0080] Figure 3 This is a SEM image of the modified hollow glass microspheres provided in Example 1 of the present invention. DETAILED DESCRIPTION

[0081] The technical solution of the present invention is described in detail below in conjunction with specific embodiments and their accompanying drawings. The embodiments recorded herein are specific embodiments of the present invention, which are used to illustrate the concept of the present invention; these descriptions are explanatory and exemplary and should not be construed as limitations on the embodiments of the present invention and the scope of protection of the present invention. In addition to the embodiments recorded herein, those skilled in the art can also adopt other obvious technical solutions based on the contents disclosed in the claims of this application and its specification, including technical solutions that adopt any obvious replacements and modifications to the embodiments recorded herein.

[0082] The chemical reagents used in the examples and comparative examples of the present invention are all commercially available products, and their brands, specifications, manufacturers and other information are as follows:

[0083] Sodium sulfate hydrate: purchased from Nanjing Chemical Reagent Co., Ltd.

[0084] Calcium chloride hydrate: purchased from Shanghai Weitao Chemical Co., Ltd.

[0085] Hollow glass microspheres: specification HM15, purchased from Zhengzhou Shenglait Hollow Microsphere New Materials Co., Ltd.;

[0086] Polyurethane: purchased from Guangdong Yunxing Biotechnology Co., Ltd.;

[0087] Polyvinyl alcohol: purchased from Shandong Sanwei Shengtai New Material Technology Co., Ltd.;

[0088] Polypropylene alcohol: purchased from Nantong Chenrun Chemical Co., Ltd.

[0089] Formaldehyde solution: 37 wt.%, purchased from Qingdao Lianli Longmen Technology Co., Ltd.

[0090] Glutaraldehyde: 25wt.%, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.;

[0091] Silicone resin emulsion: purity 50%, purchased from Shenzhen Jipeng Silicon Fluoride Materials Co., Ltd.;

[0092] Titanium dioxide: purchased from Shanghai Puzhen Biotechnology Co., Ltd.;

[0093] Aluminum hydroxide: purchased from Tai'an Jiangzhou Biotechnology Co., Ltd.;

[0094] Carboxymethyl cellulose: purchased from Shanghai Yuanye Biotechnology Co., Ltd.;

[0095] Hydroxypropyl cellulose: purchased from Jinan World Chemical Co., Ltd.

[0096] Sodium stearate: purchased from Hubei Qifei Pharmaceutical Chemical Co., Ltd.;

[0097] Polyethylenimine: purchased from Shanghai Yihe Biotechnology Co., Ltd.;

[0098] Propylene glycol: purchased from Shandong Xintu Chemical Co., Ltd.;

[0099] Hydrofluoric acid: purchased from Anhui Xuxin Chemical Co., Ltd.

[0100] Silica sand: purchased from Tongliao Yongxin Silica Sand Co., Ltd.;

[0101] Methyl silicone resin: purchased from Hubei Xinmingtai Chemical Co., Ltd.;

[0102] Polytetrafluoroethylene resin: purchased from Shanghai Jizhi Biochemical Technology Co., Ltd.;

[0103] Aluminum powder: purchased from Sinopharm Group Chemical Reagent Co., Ltd.;

[0104] Aluminum silicate: purchased from Nantong Runfeng Chemical Co., Ltd.

[0105] Titanium dioxide: purchased from Shanghai Yuejiang Titanium Dioxide Chemical Products Co., Ltd.

[0106] Zinc oxide: purchased from Wuhan Jisheng Chemical Co., Ltd.

[0107] Example 1

[0108] like Figure 1 As shown, this embodiment provides a reflective heat-insulating stone-like energy-saving paint and a preparation method thereof, wherein the reflective heat-insulating stone-like energy-saving paint includes the following components in parts by mass: 25 parts of modified silicone resin emulsion; 7.5 parts of modified hollow glass microspheres; 50 parts of homemade reflective heat-insulating sand; 1.6 parts of thickener; 0.7 parts of dispersant; 1.5 parts of propylene glycol; and 37 parts of deionized water.

[0109] The self-made reflective heat-insulating sand comprises the following components in parts by weight: 97 parts of chemically etched silica sand; 2 parts of super weather-resistant resin; 0.5 parts of high-reflective powder; and 0.2 parts of low-absorption pigment.

[0110] The preparation method specifically comprises the following steps:

[0111] S1: Sodium sulfate hydrate is dispersed in deionized water, and ultrasonically treated at a power of 270 W for 16 minutes to obtain a sodium sulfate hydrate suspension, wherein the mass ratio of sodium sulfate hydrate to deionized water is 0.4:1; hollow glass microspheres are added to the sodium sulfate hydrate suspension to obtain a mixed solution A, wherein the mass ratio of hollow glass microspheres to sodium sulfate hydrate is 1:1, stirred at 400 rpm for 1.5 hours, filtered to obtain the first modified hollow glass microspheres, and dried at 60°C for 5 hours to obtain hollow glass microspheres embedded with fillers; polyurethane is added to deionized water to obtain a polyurethane solution with a mass fraction of 8%, and hollow glass microspheres embedded with fillers are added to obtain a mixed solution B, wherein the mass ratio of polyurethane to hollow glass microspheres embedded with fillers is 1:1, stirred at a speed of 200 rpm and a temperature of 35°C for 4 hours, filtered to obtain the second modified hollow glass microspheres, and cured at 80°C for 4 hours to obtain modified hollow glass microspheres; Figure 2 SEM image of hollow glass microspheres embedded with fillers: Sodium sulfate hydrate phase change fillers are distributed inside the hollow glass microspheres, enhancing the heat storage capacity of the microspheres; Figure 3 This is the SEM image of the modified hollow glass microspheres: after being modified with polyurethane, a layer of polyurethane film is formed on its surface, which helps to improve its dispersibility and stability.

[0112] S2: dissolving glutaraldehyde solution in deionized water to obtain a glutaraldehyde dilution solution with a mass fraction of 1%; stirring the silicone resin emulsion at room temperature at a rotation speed of 280 rpm for 32 minutes, while stirring, adding the glutaraldehyde dilution solution dropwise to the silicone resin emulsion to obtain a cross-linked modified silicone resin emulsion, wherein the mass ratio of glutaraldehyde to silicone resin is 1:10; dispersing aluminum hydroxide in deionized water, ultrasonically dispersing to obtain an aluminum hydroxide dispersion solution with a mass fraction of 15%, adding the aluminum hydroxide dispersion solution to the cross-linked modified silicone resin emulsion to obtain a mixed solution C, wherein the mass ratio of aluminum hydroxide to silicone resin is 1:3, reacting at a constant temperature of 70°C for 2 hours to obtain a mixed solution D, and cooling to room temperature to obtain a modified silicone resin emulsion;

[0113] S3: Dilute hydrofluoric acid to obtain a hydrofluoric acid solution with a mass fraction of 7%, soak silica sand in the hydrofluoric acid solution, wherein the mass ratio of hydrofluoric acid to silica sand is 1:5; soak for 10 minutes, rinse with deionized water to obtain modified silica sand, and dry at 60°C for 4 hours to obtain chemically etched silica sand; add methyl silicone resin to anhydrous ethanol to obtain a methyl silicone resin solution with a mass fraction of 10%, add chemically etched silica sand, aluminum powder, and titanium dioxide to the super weather-resistant resin solution to obtain a mixed solution E, put the mixed solution E into an oven and cure at 55°C for 5 hours to obtain coarse reflective insulation sand, and obtain homemade reflective insulation sand with a particle size of 300μm by sieving;

[0114] S4: Carboxymethyl cellulose, sodium stearate and propylene glycol are added to deionized water in sequence, stirred to obtain a base solution, and then homemade reflective insulation sand, modified hollow glass microspheres and modified silicone resin emulsion are added in sequence, stirred to obtain a reflective insulation imitation stone energy-saving coating.

[0115] Example 2

[0116] The present embodiment provides a reflective heat-insulating stone-like energy-saving paint and a preparation method thereof, wherein the reflective heat-insulating stone-like energy-saving paint comprises the following components in parts by weight: 20 parts of modified silicone resin emulsion; 5 parts of modified hollow glass microspheres; 40 parts of homemade reflective heat-insulating sand; 2.4 parts of thickener; 0.5 parts of dispersant; 1 part of propylene glycol; and 35 parts of deionized water.

[0117] The self-made reflective heat-insulating sand comprises the following components in parts by weight: 98 parts of chemically etched silica sand; 2.5 parts of super weather-resistant resin; 0.2 parts of high-reflective powder; and 0.5 parts of low-absorption pigment.

[0118] The preparation method specifically comprises the following steps:

[0119] S1: Calcium chloride hydrate is dispersed in deionized water, and ultrasonically treated at a power of 300 W for 10 minutes to obtain a calcium chloride hydrate suspension, wherein the mass ratio of calcium chloride hydrate to deionized water is 0.85:1; hollow glass microspheres are added to the calcium chloride hydrate suspension to obtain a mixed solution A, wherein the mass ratio of hollow glass microspheres to calcium chloride hydrate is 1:0.5, stirred at 460 rpm for 1.2 hours, filtered to obtain the first modified hollow glass microspheres, and dried at 50°C for 10 hours to obtain the filler-embedded hollow glass microspheres; polyvinyl alcohol is added to deionized water to obtain a polyvinyl alcohol solution with a mass fraction of 10%, and the filler-embedded hollow glass microspheres are added to obtain a mixed solution B, wherein the mass ratio of polyvinyl alcohol to the filler-embedded hollow glass microspheres is 1:2, stirred at a speed of 250 rpm and a temperature of 45°C for 3 hours, filtered to obtain the second modified hollow glass microspheres, and cured at 70°C for 6 hours to obtain the modified hollow glass microspheres;

[0120] S2: Dissolve the formaldehyde solution in deionized water to obtain a formaldehyde dilution with a mass fraction of 1.5%; stir the silicone resin emulsion at room temperature at a speed of 250 rpm for 35 minutes, and while stirring, drop the formaldehyde dilution into the silicone resin emulsion to obtain a cross-linked modified silicone resin emulsion, wherein the mass ratio of formaldehyde to silicone resin is 1:5; disperse titanium dioxide in deionized water, and ultrasonically disperse to obtain a titanium dioxide dispersion with a mass fraction of 10%, and add the titanium dioxide dispersion to the cross-linked modified silicone resin emulsion to obtain a mixed solution C, wherein the mass ratio of titanium dioxide to silicone resin is 1:2, and react at a constant temperature of 78°C for 1.2 hours to obtain a mixed solution D, and cool to room temperature to obtain a modified silicone resin emulsion;

[0121] S3: dilute hydrofluoric acid to obtain a hydrofluoric acid solution with a mass fraction of 5%, soak silica sand in the hydrofluoric acid solution, wherein the mass ratio of hydrofluoric acid to silica sand is 1:10; soak for 30 minutes, rinse with deionized water to obtain modified silica sand, and dry at 65°C for 3 hours to obtain chemically etched silica sand; add polytetrafluoroethylene resin to anhydrous ethanol to obtain a polytetrafluoroethylene resin solution with a mass fraction of 7%, add chemically etched silica sand, aluminum silicate, and zinc oxide to the super weather-resistant resin solution to obtain a mixed solution E, put the mixed solution E into an oven and cure at 60°C for 4 hours to obtain coarse reflective insulation sand, and obtain homemade reflective insulation sand with a particle size of 400μm by sieving;

[0122] S4: Add hydroxypropyl cellulose, polyethyleneimine and propylene glycol to deionized water in sequence, stir to obtain a base solution, and then add homemade reflective insulation sand, modified hollow glass microspheres and modified silicone resin emulsion in sequence, stir to obtain a reflective insulation imitation stone energy-saving coating.

[0123] Example 3

[0124] The present embodiment provides a reflective heat-insulating stone-like energy-saving paint and a preparation method thereof, wherein the reflective heat-insulating stone-like energy-saving paint comprises the following components in parts by weight: 30 parts of modified silicone resin emulsion; 10 parts of modified hollow glass microspheres; 55 parts of homemade reflective heat-insulating sand; 1 part of thickener; 0.82 parts of dispersant; 1.8 parts of propylene glycol; and 40 parts of deionized water.

[0125] The self-made reflective heat-insulating sand comprises the following components in parts by weight: 96 parts of chemically etched silica sand; 3 parts of super weather-resistant resin; 0.35 parts of high-reflective powder; and 0.36 parts of low-absorption pigment.

[0126] The preparation method specifically comprises the following steps:

[0127] S1: Sodium sulfate hydrate is dispersed in deionized water, and ultrasonically treated at a power of 250W for 20 minutes to obtain a sodium sulfate hydrate suspension, wherein the mass ratio of sodium sulfate hydrate to deionized water is 0.38:1; hollow glass microspheres are added to the sodium sulfate hydrate suspension to obtain a mixed solution A, wherein the mass ratio of hollow glass microspheres to sodium sulfate hydrate is 1:2, stirred at 300rpm for 2h, filtered to obtain the first modified hollow glass microspheres, and dried at 55°C for 5.5h to obtain the hollow glass microspheres embedded with fillers; polypropylene alcohol is added to deionized water to obtain a polypropylene alcohol solution with a mass fraction of 5%, and the hollow glass microspheres embedded with fillers are added to obtain a mixed solution B, wherein the mass ratio of polypropylene alcohol to the hollow glass microspheres embedded with fillers is 1:3, stirred at a speed of 270rpm and a temperature of 40°C for 3.5h, filtered to obtain the second modified hollow glass microspheres, and cured at 75°C for 5h to obtain the modified hollow glass microspheres;

[0128] S2: Dissolve the formaldehyde solution in deionized water to obtain a formaldehyde dilution solution with a mass fraction of 2%; stir the silicone resin emulsion at room temperature at a speed of 300 rpm for 30 minutes, and while stirring, drop the formaldehyde solution into the silicone resin emulsion to obtain a cross-linked modified silicone resin emulsion, wherein the mass ratio of formaldehyde to silicone resin is 1:7.5; disperse titanium dioxide in deionized water, and ultrasonically disperse to obtain a titanium dioxide dispersion with a mass fraction of 20%, and add the titanium dioxide dispersion to the cross-linked modified silicone resin emulsion to obtain a mixed solution C, wherein the mass ratio of titanium dioxide to silicone resin is 1:4, and react at a constant temperature of 75°C for 1.5 hours to obtain a mixed solution D, and cool to room temperature to obtain a modified silicone resin emulsion;

[0129] S3: Dilute hydrofluoric acid to obtain a hydrofluoric acid solution with a mass fraction of 10%, soak silica sand in the hydrofluoric acid solution, wherein the mass ratio of hydrofluoric acid to silica sand is 1:7.5; soak for 20 minutes, rinse with deionized water to obtain modified silica sand, and dry at 68°C for 2.5 hours to obtain chemically etched silica sand; add methyl silicone resin to anhydrous ethanol to obtain a methyl silicone resin solution with a mass fraction of 8%, add chemically etched silica sand, aluminum powder, and titanium dioxide to the super weather-resistant resin solution to obtain a mixed solution E, put the mixed solution E into an oven and cure it at 58°C for 4.2 hours to obtain coarse reflective insulation sand, and obtain homemade reflective insulation sand with a particle size of 100 μm by sieving;

[0130] S4: Hydroxypropyl fiber yarn, polyethyleneimine, and propylene glycol are added to deionized water in sequence, stirred to obtain a base solution, and then homemade reflective insulation sand, modified hollow glass microspheres, and modified silicone resin emulsion are added in sequence, stirred to obtain a reflective insulation imitation stone energy-saving coating.

[0131] Example 4

[0132] The present embodiment provides a reflective heat-insulating stone-like energy-saving paint and a preparation method thereof, wherein the reflective heat-insulating stone-like energy-saving paint comprises the following components in parts by weight: 27 parts of modified silicone resin emulsion; 9 parts of modified hollow glass microspheres; 60 parts of homemade reflective heat-insulating sand; 3 parts of thickener; 1 part of dispersant; 2 parts of propylene glycol; and 30 parts of deionized water.

[0133] The self-made reflective heat-insulating sand comprises the following components in parts by weight: 95 parts of chemically etched silica sand; 2.8 parts of super weather-resistant resin; 0.4 parts of high-reflective powder; and 0.42 parts of low-absorption pigment.

[0134] The preparation method specifically comprises the following steps:

[0135] S1: Calcium chloride hydrate is dispersed in deionized water, and ultrasonically treated at a power of 200 W for 30 minutes to obtain a calcium chloride hydrate suspension, wherein the mass ratio of calcium chloride hydrate to deionized water is 0.84:1; hollow glass microspheres are added to the calcium chloride hydrate suspension to obtain a mixed solution A, wherein the mass ratio of hollow glass microspheres to calcium chloride hydrate is 1:1.5, stirred at 500 rpm for 1 hour, filtered to obtain the first modified hollow glass microspheres, and dried at 57°C for 7.5 hours to obtain the filler-embedded hollow glass microspheres; polyurethane is added to deionized water to obtain a polyurethane solution with a mass fraction of 7.6%, and the filler-embedded hollow glass microspheres are added to obtain a mixed solution B, wherein the mass ratio of polyurethane to the filler-embedded hollow glass microspheres is 1:2.4, stirred at a speed of 300 rpm and a temperature of 43°C for 3.2 hours, filtered to obtain the second modified hollow glass microspheres, and cured at 77°C for 5.4 hours to obtain the modified hollow glass microspheres;

[0136] S2: dissolving the glutaraldehyde solution in deionized water to obtain a glutaraldehyde dilution solution with a mass fraction of 1.8%; stirring the silicone resin emulsion at room temperature at a speed of 200 rpm for 40 minutes, while stirring, adding the glutaraldehyde solution dropwise to the silicone resin emulsion to obtain a cross-linked modified silicone resin emulsion, wherein the mass ratio of glutaraldehyde to the silicone resin is 1:8.2; dispersing aluminum hydroxide in deionized water, ultrasonically dispersing to obtain an aluminum hydroxide dispersion with a mass fraction of 18%, adding the aluminum hydroxide dispersion to the cross-linked modified silicone resin emulsion to obtain a mixed solution C, wherein the mass ratio of aluminum hydroxide to the silicone resin is 1:5, reacting at a constant temperature of 80°C for 1 hour to obtain a mixed solution D, and cooling to room temperature to obtain a modified silicone resin emulsion;

[0137] S3: dilute hydrofluoric acid to obtain a hydrofluoric acid solution with a mass fraction of 8%, soak silica sand in the hydrofluoric acid solution, wherein the mass ratio of hydrofluoric acid to silica sand is 1:9; soak for 25 minutes, rinse with deionized water to obtain modified silica sand, and dry at 70°C for 2 hours to obtain chemically etched silica sand; add polytetrafluoroethylene resin to anhydrous ethanol to obtain a polytetrafluoroethylene resin solution with a mass fraction of 5%, add chemically etched silica sand, aluminum silicate, and zinc oxide to the super weather-resistant resin solution to obtain a mixed solution E, put the mixed solution E into an oven and cure at 50°C for 6 hours to obtain coarse reflective insulation sand, and obtain homemade reflective insulation sand with a particle size of 500μm by sieving;

[0138] S4: Carboxymethyl cellulose, sodium stearate and propylene glycol are added to deionized water in sequence, stirred to obtain a base solution, and then homemade reflective insulation sand, modified hollow glass microspheres and modified silicone resin emulsion are added in sequence, stirred to obtain a reflective insulation imitation stone energy-saving coating.

[0139] Comparative Example 1

[0140] This embodiment provides a reflective heat-insulating stone-like energy-saving paint, which is different from Example 1 in that the mass fraction of the modified silicone resin emulsion in the reflective heat-insulating stone-like energy-saving paint is adjusted to 35 parts. Compared with Example 1, the mass fraction of the modified silicone resin emulsion in this embodiment is increased by 10 parts, and the increased mass fraction is deducted from the modified hollow glass microspheres, the homemade reflective heat-insulating sand, the thickener, the dispersant, the propylene glycol, and the deionized water in equal proportions, so that the mass fraction ratios of the other components except the modified silicone resin emulsion remain unchanged. The mass fractions of the components of the adjusted reflective heat-insulating stone-like energy-saving paint are as follows: 35 parts of modified silicone resin emulsion; 6.74 parts of modified hollow glass microspheres; 44.91 parts of homemade reflective heat-insulating sand; 1.44 parts of thickener; 0.63 parts of dispersant; 1.35 parts of propylene glycol; and 33.24 parts of deionized water.

[0141] The other process parameters and operating conditions are exactly the same as those in Example 1.

[0142] Comparative Example 2

[0143] This embodiment provides a reflective heat-insulating imitation stone energy-saving paint, which is different from Example 1 in that the mass fraction of the modified silicone resin emulsion in the reflective heat-insulating imitation stone energy-saving paint is adjusted to 10 parts. Compared with Example 1, the mass fraction of the modified silicone resin emulsion in this embodiment is reduced by 15 parts, and the reduced mass fraction is added to the mass fraction of the modified hollow glass microspheres, the homemade reflective heat-insulating sand, the thickener, the dispersant, the propylene glycol, and the deionized water in equal proportion, so that the mass fraction ratios of the other components except the modified silicone resin emulsion remain unchanged. The mass fractions of the components of the adjusted reflective heat-insulating imitation stone energy-saving paint are as follows: 10 parts of modified silicone resin emulsion; 8.64 parts of modified hollow glass microspheres; 57.63 parts of homemade reflective heat-insulating sand; 1.84 parts of thickener; 0.81 parts of dispersant; 1.73 parts of propylene glycol; 42.65 parts of deionized water.

[0144] The other process parameters and operating conditions are exactly the same as those in Example 1.

[0145] Comparative Example 3

[0146] This embodiment provides a reflective heat-insulating imitation stone energy-saving paint, which is different from Example 1 in that the mass fraction of the modified hollow glass microspheres in the reflective heat-insulating imitation stone energy-saving paint is adjusted to 15 parts. Compared with Example 1, the mass fraction of the modified hollow glass microspheres in this embodiment is increased by 7.5 parts, and the increased mass fraction is deducted from the modified silicone resin emulsion, the homemade reflective heat-insulating sand, the thickener, the dispersant, the propylene glycol, and the deionized water in equal proportions, so that the mass fraction ratios of the other components except the modified hollow glass microspheres remain unchanged. The mass fractions of the components of the adjusted reflective heat-insulating imitation stone energy-saving paint are as follows: 23.38 parts of modified silicone resin emulsion; 15 parts of modified hollow glass microspheres; 46.76 parts of homemade reflective heat-insulating sand; 1.50 parts of thickener; 0.65 parts of dispersant; 1.40 parts of propylene glycol; 34.60 parts of deionized water.

[0147] The other process parameters and operating conditions are exactly the same as those in Example 1.

[0148] Comparative Example 4

[0149] This embodiment provides a reflective heat-insulating imitation stone energy-saving paint, which is different from Example 1 in that the mass fraction of the modified hollow glass microspheres in the reflective heat-insulating imitation stone energy-saving paint is adjusted to 2 parts. Compared with Example 1, the mass fraction of the modified hollow glass microspheres in this embodiment is reduced by 5.5 parts, and the reduced mass fraction is added to the mass fraction of the modified silicone resin emulsion, the homemade reflective heat-insulating sand, the thickener, the dispersant, the propylene glycol, and the deionized water in equal proportion, so that the mass fraction ratios of the other components except the modified hollow glass microspheres remain unchanged. The mass fractions of the components of the adjusted reflective heat-insulating imitation stone energy-saving paint are as follows: 26.19 parts of modified silicone resin emulsion; 2 parts of modified hollow glass microspheres; 52.37 parts of homemade reflective heat-insulating sand; 1.68 parts of thickener; 0.73 parts of dispersant; 1.57 parts of propylene glycol; 38.76 parts of deionized water.

[0150] The other process parameters and operating conditions are exactly the same as those in Example 1.

[0151] The performance test of the reflective heat-insulating stone-like energy-saving coatings of the above-mentioned Examples 1-4 and Comparative Examples 1-4 was carried out, and the specific process is as follows:

[0152] Test the thermal conductivity of the sample according to GB / T 10294-2008;

[0153] Test the lightness value of the sample according to GB / T 11186.2-1989;

[0154] The solar reflectance, near-infrared reflectance and hemispherical emissivity of the test samples are tested according to JG / T 235-2014.

[0155] The test results are shown in Table 1.

[0156] Table 1: Performance test results of reflective heat-insulating stone-like energy-saving coatings of Examples 1-4 and Comparative Examples 1-4

[0157]

[0158] As can be seen from Table 1, the reflective heat-insulating stone-like energy-saving coatings prepared in Examples 1-4 provided by the present invention have good sunlight reflection, near-infrared and heat-insulating energy-saving performance, which is conducive to the application of reflective heat-insulating stone-like energy-saving coatings in building exterior wall decoration.

[0159] From the test results of Example 1 and Comparative Examples 1 and 2, it can be seen that the silicone resin has a relatively low thermal conductivity. However, when the content of the modified silicone resin is too high, the viscosity of the coating may increase, forming a denser structure, affecting the thermal conductivity; at the same time, it causes uneven dispersion of the pigment, which may affect the reflective performance and reduce the overall light reflectivity. If the content is too low, the reinforcing effect of the crosslinking agent and the white pigment may not be fully exerted, resulting in a decrease in the thermal insulation performance of the coating and affecting the weather resistance and mechanical strength of the coating.

[0160] From the test results of Example 1 and Comparative Examples 3 and 4, it can be seen that the modified hollow glass microspheres obtained by co-modification of the inorganic phase change filler and the polymer modifier can improve the reflective and thermal insulation properties of the coating, but when the content of the modified hollow glass microspheres in the coating is too high, it may lead to a loose structure, which in turn increases the heat conduction path, thereby increasing the thermal conductivity coefficient; and an excessive amount of modified hollow glass microspheres may lead to uneven reflective properties; when the content is too low, it may not be sufficient to enhance the reflective ability of the coating.

[0161] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for preparing a reflective heat-insulating stone-like energy-saving coating, characterized in that: The preparation method comprises: S1: dispersing an inorganic phase change filler in deionized water, ultrasonically treating the mixture to obtain an inorganic phase change filler suspension; adding hollow glass microspheres to the inorganic phase change filler suspension to obtain a mixed solution A, stirring the mixture, filtering the mixture to obtain first modified hollow glass microspheres, and drying the mixture to obtain filler-embedded hollow glass microspheres; adding a polymer modifier to deionized water to obtain a polymer modifier solution, adding the filler-embedded hollow glass microspheres to obtain a mixed solution B, stirring the mixture to react, filtering the mixture to obtain second modified hollow glass microspheres, and curing the mixture to obtain modified hollow glass microspheres; S2: dissolving a crosslinking agent in deionized water to obtain a crosslinking agent solution; stirring the silicone resin emulsion at room temperature, and while stirring, dropping the crosslinking agent solution into the silicone resin emulsion to obtain a crosslinked modified silicone resin emulsion; dispersing a white pigment in deionized water, ultrasonically dispersing to obtain a white pigment dispersion, adding the white pigment dispersion to the crosslinked modified silicone resin emulsion to obtain a mixed solution C, reacting at a constant temperature to obtain a mixed solution D, and cooling to room temperature to obtain a modified silicone resin emulsion; S3: Soaking silica sand in a hydrofluoric acid solution, washing after soaking to obtain modified silica sand, and drying to obtain chemically etched silica sand; adding chemically etched silica sand, high-reflective powder, and low-absorption pigment to a super-weather-resistant resin solution to obtain a mixed solution E, placing the mixed solution E in an oven for curing to obtain coarse reflective thermal insulation sand, and obtaining reflective thermal insulation sand by screening; S4: adding a thickener, a dispersant, and propylene glycol to deionized water in sequence, stirring to obtain a base solution, and then adding reflective heat-insulating sand, modified hollow glass microspheres, and modified silicone resin emulsion in sequence, stirring to obtain a reflective heat-insulating imitation stone energy-saving coating; The inorganic phase change filler is sodium sulfate hydrate or calcium chloride hydrate; The polymer modifier is polyurethane, polyvinyl alcohol or polypropylene alcohol; The reflective heat-insulating stone-like energy-saving paint comprises the following components in parts by weight: 20-30 parts of modified silicone resin emulsion; 5-10 parts of modified hollow glass microspheres; 40-60 parts of reflective heat-insulating sand; 1-3 parts of thickener; 0.5-1 part of dispersant; 1-2 parts of propylene glycol; and 30-40 parts of deionized water.

2. The method for preparing a reflective heat-insulating stone-like energy-saving paint according to claim 1, characterized in that: In S1: When the inorganic phase change filler is sodium sulfate hydrate, the mass ratio of the inorganic phase change filler to deionized water in the inorganic phase change filler suspension is (0.3-0.4):1; When the inorganic phase change filler is calcium chloride hydrate, the mass ratio of the inorganic phase change filler to deionized water in the inorganic phase change filler suspension is (0.8-0.85):1; The power of ultrasonic treatment of the inorganic phase change filler dispersed in deionized water is 200-300W; The inorganic phase change filler is dispersed in deionized water and ultrasonically treated for 10-30 minutes; The mass ratio of the hollow glass microspheres to the inorganic phase change filler is 1:(0.5-2); The mixed solution A is stirred at a speed of 300-500 rpm; The stirring time of the mixed solution A is 1-2h; The drying temperature of the first modified hollow glass microspheres is 50-60°C; The first modified hollow glass microspheres are dried for 5-10 hours.

3. The method for preparing a reflective heat-insulating stone-like energy-saving paint according to claim 1, characterized in that: In S1: The mass fraction of the polymer modifier in the polymer modifier solution is 5-10%; The mass ratio of the polymer modifier to the hollow glass microspheres embedded with fillers is 1:(1-3); The stirring speed of the mixed solution B is 200-300 rpm; The temperature of the mixed solution B stirring reaction is 35-45°C; The stirring reaction time of the mixed solution B is 3-4h; The curing temperature of the second modified hollow glass microsphere is 70-80°C; The curing time of the second modified hollow glass microspheres is 4-6 hours.

4. The method for preparing a reflective heat-insulating stone-like energy-saving paint according to claim 1, characterized in that: In S2: The cross-linking agent is formaldehyde or glutaraldehyde; The mass fraction of the crosslinking agent in the crosslinking agent solution is 1-2%; The mass ratio of the crosslinking agent to the silicone resin is 1:(5-10); The stirring speed when the silicone resin emulsion and the crosslinking agent solution are mixed is 200-300 rpm; The stirring time when the silicone resin emulsion and the crosslinking agent solution are mixed is 30-40 minutes.

5. The method for preparing a reflective heat-insulating stone-like energy-saving paint according to claim 1, characterized in that: In S2: The white pigment is titanium dioxide or aluminum hydroxide; The mass fraction of the white pigment in the white pigment dispersion is 10-20%; The mass ratio of the white pigment to the cross-linked modified silicone resin in the mixed solution C is 1:(2-5); The temperature of the isothermal reaction of the mixed solution C is 70-80°C; The isothermal reaction time of the mixed solution C is 1-2 hours.

6. The method for preparing a reflective heat-insulating stone-like energy-saving paint according to claim 1, characterized in that: In S3: The mass fraction of hydrofluoric acid in the hydrofluoric acid solution is 5-10%; The mass ratio of the hydrofluoric acid to the silica sand is 1:(5-10); The silica sand is immersed in the hydrofluoric acid solution for 10-30 minutes; The temperature of drying the modified silica sand is 60-70°C; The modified silica sand is dried for 2-4 hours.

7. The method for preparing a reflective heat-insulating stone-like energy-saving paint according to claim 5, characterized in that: In S3: The super weather-resistant resin is methyl silicone resin or polytetrafluoroethylene resin; The mass fraction of the super weather resistant resin in the super weather resistant resin solution is 5-10%; The temperature at which the mixed solution E is cured in the oven is 50-60°C; The mixed solution E is cured in the oven for 4-6 hours; The particle size of the reflective heat-insulating sand is 100-500 μm.

8. The method for preparing a reflective heat-insulating stone-like energy-saving paint according to claim 1, characterized in that: The reflective heat-insulating sand comprises the following components in parts by weight: 95-98 parts of chemically etched silica sand, 2-3 parts of super-weather-resistant resin, 0.2-0.5 parts of high-reflective powder, and 0.2-0.5 parts of low-absorption pigment; Wherein, the highly reflective powder is aluminum powder or aluminum silicate; The low absorption pigment is titanium dioxide or zinc oxide.

9. A reflective heat-insulating stone-like energy-saving paint prepared by the preparation method according to any one of claims 1 to 8, characterized in that: The reflective heat-insulating stone-like energy-saving paint comprises the following components in parts by weight: 20-30 parts of modified silicone resin emulsion; 5-10 parts of modified hollow glass microspheres; 40-60 parts of reflective heat-insulating sand; 1-3 parts of thickener; 0.5-1 parts of dispersant; 1-2 parts of propylene glycol; and 30-40 parts of deionized water. wherein the thickener is carboxymethyl cellulose or hydroxypropyl cellulose; The dispersant is sodium stearate or polyethyleneimine.

10. Use of a reflective, heat-insulating, stone-like energy-saving paint obtained by the preparation method according to any one of claims 1 to 8 in building exterior wall decoration.

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