A thermal insulation coating based on cesium tungsten oxide and its preparation method and application

Abstract

The present invention belongs to the technical field of coating compositions, and provides a thermal insulation coating based on cesium tungsten oxide, and a preparation method and application thereof, wherein the thermal insulation coating comprises the following raw materials by weight: 25-40 parts of modified epoxy resin, 15-25 parts of cesium tungsten oxide slurry, 6-10 parts of film-forming aid, 2-6 parts of modified ultraviolet absorber, 0.5-1 parts of defoamer, 1-2 parts of dispersant, and 0.8-2 parts of curing agent; wherein the cesium tungsten oxide slurry comprises the following raw materials by weight: 30-40 parts of cesium tungsten oxide powder, 45-70 parts of solvent, and 0.4-0.8 parts of composite silane coupling agent. The thermal insulation coating of the present invention has low transmittance, good toughness, good thermal insulation effect, good transparency, can be used in the field of glass curtain walls and building windows, and has high market value.

Description

Technical Field

[0001] The invention belongs to the technical field of coating compositions, and in particular relates to a thermal insulation coating based on cesium tungsten oxide and a preparation method and application thereof. Background Art

[0002] Thermal insulation coating is a new type of coating that absorbs and shields near-infrared light and ultraviolet light. It can increase the thermal insulation effect of building glass structures such as building windows and glass curtain walls, achieving the purpose of energy saving and consumption reduction, which is of great significance. However, 95% of building energy consumption is due to the energy consumption of heating, air conditioning, electric fans and household appliances in my country's buildings. Therefore, thermal insulation and heat insulation of buildings are of great significance to building energy conservation.

[0003] Thermal insulation coatings can be divided into two categories according to the properties of their components: water-based and solvent-based. When the external environmental conditions are the same, the coating formed by solvent-based coatings has a higher hardness, scratch resistance and strong adhesion. The comprehensive performance of solvent-based coatings is more advantageous than that of water-based coatings.

[0004] Chinese patent CN 109233362 B discloses a self-cleaning nano thermal insulation coating based on cesium tungsten bronze and a preparation method thereof. The preparation method comprises: using WCl6 and CsOH·5H2O as raw materials, PVP as a surfactant, and acetic acid as an acid catalyst, and using a hydrothermal method to prepare nano cesium tungsten bronze particles; using TiCl4 to prepare nano TiO2 particles; ball milling and dispersing the nano cesium tungsten bronze particles, nano TiO2 particles, a silane coupling agent and water together to prepare an aqueous slurry of cesium tungsten bronze / TiO2 composite particles; and adjusting the concentration of the aqueous slurry of cesium tungsten bronze / TiO2 composite particles to obtain a self-cleaning nano thermal insulation coating. The self-cleaning nano thermal insulation coating and the preparation method thereof of the invention are simple and practical, and have good thermal insulation effect and good self-cleaning effect; however, the thermal insulation coating has a low hardness and is prone to scratches.

[0005] Therefore, there is an urgent need to develop a thermal insulation coating based on cesium tungsten oxide, which has good thermal insulation and wear resistance. Summary of the invention

[0006] In view of the existing technical problems, the purpose of the present invention is to provide a thermal insulation coating based on cesium tungsten oxide and a preparation method thereof. The thermal insulation coating of the present invention has low transmittance, good toughness, and good thermal insulation effect. It can be used in the field of glass curtain walls and building windows and has high market value.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] The present invention first provides a thermal insulation coating based on cesium tungsten oxide, wherein the thermal insulation coating comprises the following raw materials by weight: 25-40 parts of modified epoxy resin, 15-25 parts of cesium tungsten oxide slurry, 6-10 parts of film-forming aid, 2-6 parts of modified ultraviolet absorber, 0.5-1 parts of defoamer, 1-2 parts of dispersant, and 0.8-2 parts of curing agent;

[0009] The cesium tungsten oxide slurry comprises the following raw materials by weight: 30-40 parts of cesium tungsten oxide powder, 45-70 parts of solvent, and 0.4-0.8 parts of composite silane coupling agent;

[0010] The preparation method of the modified epoxy resin comprises the following steps:

[0011] S1. Add diphenol propane and epichlorohydrin into a reaction kettle, heat in a water bath to 70-78°C, stir until bisphenol A is completely dissolved, reflux, and obtain a transparent liquid;

[0012] S2. After the system is cooled to 60-68°C, add 0.25-0.4 g / ml of sodium hydroxide solution to the transparent liquid obtained in step S1, control the addition time to 3-4h, heat to 65-78°C, and continue the reaction for 1.5-2.5h to obtain an oily liquid;

[0013] S3. The oily liquid obtained in step S2 is added to the mixed solvent for extraction, washed, the oil layers are combined, and rotary evaporated to obtain a bisphenol A epoxy resin;

[0014] S4. In step S3, a polyurethane-modified epoxy resin is added to the bisphenol A epoxy resin obtained, and the mixture is blended to obtain a modified epoxy resin;

[0015] The preparation method of the modified ultraviolet absorber comprises the following steps:

[0016] (1) Add 1-allyl-3-chloro-5-fluorobenzene, N-dodecylglycine, dimethyl sulfoxide and triethylamine to a reaction kettle, mix and stir for 30-60 minutes, add 10-15wt% sodium hydroxide solution, heat to 80-100°C, react for 3.5-4 hours, rotary evaporate, purify by column chromatography, and distill under reduced pressure to obtain an intermediate;

[0017] (2) The intermediate obtained in step (1), 3-(3-hydroxy-3-methylbutyl)-2,4,6-trihydroxybenzophenone and dimethyl sulfoxide are added to a reaction kettle, an inert gas is introduced, the mixture is stirred for 30-60 min, a concentrated sulfuric acid solution is added, the temperature is raised to 100-120° C. and the mixture is reacted for 3-4 h, the mixture is cooled to room temperature, a sodium bicarbonate solution is added, the mixture is separated, the organic layer is taken and distilled under reduced pressure, and then purified by column chromatography and distilled under reduced pressure to obtain a modified ultraviolet absorber.

[0018] The reaction mechanism and effects of the present invention are as follows:

[0019] 1. The modified epoxy resin of the present invention is obtained by blending bisphenol A epoxy resin and polyurethane modified epoxy resin in a specific ratio. Bisphenol A epoxy resin has excellent adhesion, high strength and chemical corrosion resistance, but the high curing density of bisphenol A epoxy resin may lead to high brittleness and poor impact resistance of the material. By introducing polyurethane prepolymer, polyurethane modified epoxy resin can form epoxy resin / polyurethane interpenetrating network polymer, improve the thermal stability, tensile strength and impact strength of the material; and the introduction of polyurethane can significantly improve the toughness of epoxy resin and reduce its brittleness, thereby obtaining better impact resistance.

[0020] Meanwhile, the present invention synthesizes bisphenol A epoxy resin. Firstly, the viscosity of the bisphenol A epoxy resin is reduced by controlling the molar ratio of diphenol propane to epichlorohydrin, and the epoxy content and transparency are increased. Furthermore, a 0.25-0.4 g / ml sodium hydroxide aqueous solution is selected and the dropping speed and time are controlled to avoid violent boiling and hydrolysis of the raw material epichlorohydrin, thereby increasing the epoxy content of the bisphenol A epoxy resin. Secondly, the mixed solvent selected during extraction not only greatly improves the separation effect and avoids emulsification, but also can make the product higher in purity and more transparent in color.

[0021] 2. The present invention synthesizes a new type of ultraviolet absorber, which can cooperate with cesium tungsten oxide slurry to absorb light and heat, improve ultraviolet resistance, have good heat resistance and stability, and have a toughening effect.

[0022] On the one hand, 3-(3-hydroxy-3-methylbutane)-2,4,6-trihydroxybenzophenone can effectively protect glass and prevent it from deteriorating due to light exposure. The internal hydrogen bonds formed between the hydroxyl and ketone groups make it have strong ultraviolet absorption. After absorbing ultraviolet light, the molecules undergo thermal vibrations, the internal hydrogen bonds are destroyed, and the compound releases the ultraviolet energy as other energy, closing the chelate ring and absorbing ultraviolet light in a continuous cycle. At the same time, the introduction of intermediates will cause the spectral absorption of the chromophore to move to the long-wave direction, improve its ultraviolet resistance, and cooperate with the cesium tungsten oxide slurry to absorb light and heat. , thereby making the formed coating have better thermal insulation effect; on the other hand, the introduction of fluorine-containing groups, the electronegativity of fluorine atoms is very high, which makes the carbon-fluorine bond of fluorine-containing compounds have good stability. Fluorine-containing compounds can withstand high temperature environments and corrosion by corrosive substances such as strong acids and alkalis, thereby improving thermal stability and chemical stability, thereby making the final thermal insulation coating have good heat resistance and stability, and improving service life; in addition, the long carbon chain contained in N-dodecylglycine can be interspersed between the macromolecular chains of the resin, which has a toughening effect, thereby enhancing the impact resistance of the glass material.

[0023] 3. There are many hydroxyl groups on the surface of cesium tungsten oxide nanoparticles, which makes it difficult to disperse evenly in organic polymer resins. If the dispersion is uneven, gaps may appear on the interface of the resin material, which will increase the chance of water entering the gaps. The penetration of water will cause the resin material to gradually decompose and become brittle, and its performance will deteriorate.

[0024] The present invention selects specific weight portions of solvent and composite silane coupling agent to form cesium tungsten oxide slurry, which can improve the compatibility of cesium tungsten oxide nanopowder and resin, thereby improving their dispersibility in the resin and improving the heat insulation performance of the resin.

[0025] In some embodiments, the molar ratio of diphenol propane to epichlorohydrin in step S1 is 1:(8-10).

[0026] In some embodiments, the mass ratio of the bisphenol A epoxy resin to the polyurethane modified epoxy resin in step S4 is (9-11):1.

[0027] Preferably, the mixed solvent in step S3 is benzene and distilled water at a temperature of 40-60°C.

[0028] In some embodiments, the molar ratio of 1-allyl-3-chloro-5-fluorobenzene to N-dodecylglycine in step (1) is (1.05-1.2):1.

[0029] In some embodiments, the molar ratio of the intermediate to 3-(3-hydroxy-3-methylbutanyl)-2,4,6-trihydroxybenzophenone in step (2) is (1.1-2.2):1.

[0030] Preferably, the particle size of the cesium tungsten oxide powder is 35-55 nm.

[0031] In some embodiments, the solvent in the cesium tungsten oxide slurry is 40-60 parts of ethylene glycol butyl ether acetate, 2-6 parts of propylene glycol methyl ether, 1-3 parts of propylene glycol methyl ether acetate and 1-2 parts of ethylene glycol butyl ether.

[0032] In some embodiments, the film-forming aid is tetraethyl orthosilicate.

[0033] In some embodiments, the defoaming agent is a silicone defoaming agent.

[0034] In some embodiments, the dispersant is an acrylic copolymer solution.

[0035] In some embodiments, the curing agent is dicyandiamide.

[0036] The present invention also provides a method for preparing a thermal insulation coating based on cesium tungsten oxide, comprising the following steps:

[0037] 1. Mix cesium tungsten oxide powder, solvent and composite silane coupling agent, and perform ball milling to obtain cesium tungsten oxide slurry;

[0038] 2. Mechanically blend the cesium tungsten oxide slurry obtained in step 1, modified epoxy resin, film-forming aid, modified ultraviolet absorber, defoamer, dispersant and curing agent to obtain a thermal insulation coating.

[0039] The third aspect of the present invention provides an application of a thermal insulation coating based on cesium tungsten oxide, which is used in the fields of glass curtain walls, building windows, etc.

[0040] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0041] 1. The heat-insulating coating of the present invention has low transmittance, good toughness, good heat-insulating effect, good transparency, can be used in the field of glass curtain walls and building windows, and has high market value.

[0042] 2. The modified epoxy resin of the present invention is obtained by blending bisphenol A epoxy resin and polyurethane modified epoxy resin in a specific ratio. The synergistic effect of the two can improve the thermal stability, tensile strength and impact strength of the material; at the same time, the bisphenol A epoxy resin synthesized by the present invention has higher purity, higher epoxy content and more transparent color.

[0043] 3. The present invention synthesizes a new type of ultraviolet absorber, which can cooperate with cesium tungsten oxide slurry to absorb light and heat, improve ultraviolet resistance, have good heat resistance and stability, and have a toughening effect.

[0044] 4. The present invention selects a specific silane coupling agent and a solvent to modify the cesium tungsten oxide nanopowder so that it can be better integrated into the resin, avoid the adverse effects of moisture, and improve the overall performance of the material. DETAILED DESCRIPTION

[0045] The present invention will be described below in conjunction with specific embodiments. It should be noted that the following embodiments are examples of the present invention and are only used to illustrate the present invention, rather than to limit the present invention. Other combinations and various modifications within the concept of the present invention may be performed without departing from the spirit or scope of the present invention.

[0046] The thermal insulation coatings were prepared according to the proportions of the raw materials and the preparation methods specified in the following examples and comparative examples.

[0047] In order to facilitate those skilled in the art to implement the present invention, some raw material manufacturers of the embodiments and comparative examples are described as follows:

[0048] Polyurethane modified epoxy resin: purchased from Langfang Zhan'ao Environmental Protection Technology Co., Ltd.; bisphenol A epoxy resin: purchased from Meizhou Fuxi Chemical Co., Ltd.; cesium tungsten oxide powder: purchased from Hangzhou Jikang New Materials Co., Ltd., particle size 40nm; silicone defoamer: purchased from Hunan Jiaxinzhi New Materials Technology Co., Ltd., model BYK-141; dispersant: purchased from Dongguan Huazhiyuan Chemical Co., Ltd., model BYK-2020; other raw materials are not specially specified and can be purchased from the market.

[0049] Preparation Example 1

[0050] The preparation method of modified epoxy resin A comprises the following steps:

[0051] S1. Add 4.56 g of diphenol propane and 16.65 g of epichlorohydrin into a reaction kettle, heat in a water bath to 75°C, stir until bisphenol A is completely dissolved, reflux, and obtain a transparent liquid;

[0052] S2. After the system is cooled to 65°C, 0.32 g / ml of sodium hydroxide aqueous solution is added dropwise to the transparent liquid obtained in step S1 at a dropping speed of 0.2 ml / min. The dropping time is controlled to 3.5 h, heated to 70°C, and the reaction is continued for 2 h to obtain an oily liquid;

[0053] S3. 8 g of the oily liquid obtained in step S2 was extracted by adding 60 ml of benzene and 40 ml of distilled water at a temperature of 50°C, and the layers were allowed to stand for stratification. The water layer was washed three times with 20 ml of benzene each time, and the oil layers were combined. The layers were then washed with 20 ml of distilled water at 50°C each time until the water layer was neutral, and the oil layers were combined and rotary evaporated to obtain a bisphenol A epoxy resin.

[0054] S4. Add 0.4 g of polyurethane-modified epoxy resin to 4 g of bisphenol A epoxy resin obtained in step S3, and blend them to obtain modified epoxy resin A.

[0055] Preparation Example 2

[0056] The preparation method of modified epoxy resin B is the same as that of Preparation Example 1, except that the amount of epichlorohydrin added is 12.03 g.

[0057] Preparation Example 3

[0058] The preparation method of modified epoxy resin C is the same as that of Preparation Example 1, except that the amount of polyurethane modified epoxy resin added is 0.56 g.

[0059] Preparation Example 4

[0060] The preparation method of the modified ultraviolet absorber A comprises the following steps:

[0061] (1) Add 22 mmol 1-allyl-3-chloro-5-fluorobenzene, 20 mmol N-dodecylglycine, 40 ml dimethyl sulfoxide and 4 ml triethylamine to a reaction kettle, mix and stir for 45 min, add 4 ml 12 wt% sodium hydroxide solution, heat to 90 ° C, react for 4 h, remove part of the solvent by rotary evaporation, and then purify by column chromatography (the eluent is a mixed solvent of benzene and methanol in a volume ratio of 9:1), and remove the eluent by reduced pressure distillation to obtain an intermediate;

[0062] (2) 15 mmol of the intermediate obtained in step (1), 10 mmol of 3-(3-hydroxy-3-methylbutyl)-2,4,6-trihydroxybenzophenone and 80 ml of dimethyl sulfoxide were added to a reaction kettle, nitrogen was introduced, and the mixture was stirred for 50 min. 6 ml of 98 wt % concentrated sulfuric acid solution was added, the mixture was heated to 110° C. and reacted for 4 h. The mixture was cooled to room temperature, and a 20 wt % sodium bicarbonate solution was added to neutralize the mixture until the pH value was neutral. The mixture was separated, and the organic layer was distilled under reduced pressure to remove part of the solvent. The mixture was purified by column chromatography (the eluent was a mixed solvent of benzene and ether in a volume ratio of 3:2). The eluent was distilled under reduced pressure to obtain a modified ultraviolet absorber A.

[0063] Preparation Example 5

[0064] The preparation method of modified ultraviolet absorber B is the same as that of Preparation Example 4, except that the amount of 1-allyl-3-chloro-5-fluorobenzene added is 16 mmol.

[0065] Preparation Example 6

[0066] The preparation method of modified ultraviolet absorber C is the same as that of Preparation Example 4, except that the amount of the intermediate added in step (2) is 30 mmol.

[0067] Example 1

[0068] A thermal insulation coating based on cesium tungsten oxide, comprising the following raw materials by weight: 32.5 parts of modified epoxy resin A, 20 parts of cesium tungsten oxide slurry, 8 parts of tetraethyl orthosilicate, 4 parts of modified ultraviolet absorber A, 10.75 parts of organosilicon defoamer BYK-141, 1.5 parts of dispersant BYK-2020, and 1.4 parts of dicyandiamide;

[0069] The cesium tungsten oxide slurry comprises the following raw materials by weight: 35 parts of cesium tungsten oxide powder, 50 parts of ethylene glycol butyl ether acetate, 4 parts of propylene glycol methyl ether, 2 parts of propylene glycol methyl ether acetate, 1.5 parts of ethylene glycol butyl ether, 0.3 parts of 3-aminopropyltriethoxysilane, and 0.3 parts of tetra-n-propoxysilane.

[0070] The preparation method of the thermal insulation coating of this embodiment comprises the following steps:

[0071] 1. Cesium tungsten oxide powder, ethylene glycol butyl ether acetate, propylene glycol methyl ether, propylene glycol methyl ether acetate, ethylene glycol butyl ether, 3-aminopropyltriethoxysilane and tetra-n-propoxysilane were mixed, and ball-milled at 2500 rpm and 35° C. for 7 h to obtain cesium tungsten oxide slurry;

[0072] 2. Mechanically blend the cesium oxide tungsten slurry obtained in step 1, modified epoxy resin A, ethyl orthosilicate, modified ultraviolet absorber A, silicone defoamer BYK-141, dispersant BYK-2020, and dicyandiamide to obtain a thermal insulation coating.

[0073] Example 2

[0074] A thermal insulation coating based on cesium tungsten oxide, comprising the following raw materials by weight: 25 parts of modified epoxy resin A, 15 parts of cesium tungsten oxide slurry, 6 parts of tetraethyl orthosilicate, 2 parts of modified ultraviolet absorber A, 10.5 parts of organosilicon defoamer BYK-141, 1 part of dispersant BYK-2020, and 0.8 parts of dicyandiamide;

[0075] The cesium tungsten oxide slurry comprises the following raw materials by weight: 30 parts of cesium tungsten oxide powder, 41 parts of ethylene glycol butyl ether acetate, 2 parts of propylene glycol methyl ether, 1 part of propylene glycol methyl ether acetate, 1 part of ethylene glycol butyl ether, 0.2 parts of 3-aminopropyltriethoxysilane, and 0.2 parts of tetra-n-propoxysilane.

[0076] The preparation method of the thermal insulation coating of this embodiment is the same as that of Example 1.

[0077] Example 3

[0078] A thermal insulation coating based on cesium tungsten oxide, comprising the following raw materials by weight: 40 parts of modified epoxy resin A, 25 parts of cesium tungsten oxide slurry, 10 parts of tetraethyl orthosilicate, 6 parts of modified ultraviolet absorber A, 11 parts of organosilicon defoamer BYK-14, 2 parts of dispersant BYK-2020, and 2 parts of dicyandiamide;

[0079] The cesium tungsten oxide slurry comprises the following raw materials by weight: 40 parts of cesium tungsten oxide powder, 59 parts of ethylene glycol butyl ether acetate, 6 parts of propylene glycol methyl ether, 3 parts of propylene glycol methyl ether acetate and 2 parts of ethylene glycol butyl ether, 0.4 parts of 3-aminopropyltriethoxysilane and 0.4 parts of tetra-n-propoxysilane.

[0080] The preparation method of the thermal insulation coating of this embodiment is the same as that of Example 1.

[0081] Example 4

[0082] A thermal insulation coating based on cesium tungsten oxide and a preparation method thereof, wherein the specific implementation manner is the same as that of Example 1, except that an equal amount of modified epoxy resin B is used to replace modified epoxy resin A.

[0083] Example 5

[0084] A thermal insulation coating based on cesium tungsten oxide and a preparation method thereof, wherein the specific implementation manner is the same as that of Example 1, except that an equal amount of modified epoxy resin C is used to replace modified epoxy resin A.

[0085] Example 6

[0086] A thermal insulation coating based on cesium tungsten oxide and a preparation method thereof, wherein the specific implementation manner is the same as that of Example 1, except that an equal amount of modified ultraviolet absorber B is used to replace the modified ultraviolet absorber A.

[0087] Example 7

[0088] A thermal insulation coating based on cesium tungsten oxide and a preparation method thereof, wherein the specific implementation manner is the same as that of Example 1, except that an equal amount of modified ultraviolet absorber C is used to replace modified ultraviolet absorber A.

[0089] Example 8

[0090] A thermal insulation coating based on cesium tungsten oxide and a preparation method thereof. The specific implementation method is the same as that of Example 1, except that 57.5 parts of ethylene glycol butyl ether acetate are used to replace 50 parts of ethylene glycol butyl ether acetate, 4 parts of propylene glycol methyl ether, 2 parts of propylene glycol methyl ether acetate, and 1.5 parts of ethylene glycol butyl ether.

[0091] Comparative Example 1

[0092] A thermal insulation coating based on cesium tungsten oxide and a preparation method thereof, wherein the specific implementation manner is the same as that of Example 1, except that an equal amount of commercially available bisphenol A type epoxy resin is used to replace modified epoxy resin A.

[0093] Comparative Example 2

[0094] A thermal insulation coating based on cesium tungsten oxide and a preparation method thereof, wherein the specific implementation manner is the same as that of Example 1, except that an equal amount of 2,4-dihydroxybenzophenone is used to replace the modified ultraviolet absorber A.

[0095] Effect evaluation:

[0096] The thermal insulation coatings prepared in the above-mentioned Examples 1-8 and Comparative Examples 1-2 were tested and analyzed, and the specific results are shown in Table 1.

[0097] Performance Test:

[0098] The sample was applied on the glass and cured at 70° C. for 2 h to make the dry film coating thickness 8 μm. Then, the test method was followed according to JG / T 338-2011 Test method for performance of thermal insulation coating for architectural glass.

[0099] Table 1

[0100] Serial number 365nm transmittance / % 950nm transmittance / % Visible light transmittance / % Example 1 3.3 5.9 75.1 Example 2 3.6 6.6 73.2 Example 3 3.5 6.3 74.5 Example 4 3.2 5.8 59.4 Example 5 3.3 6.0 63.6 Example 6 6.8 6.0 74.8 Example 7 5.7 5.9 75.0 Example 8 3.4 7.0 72.1 Comparative Example 1 3.3 5.8 52.1 Comparative Example 2 7.4 6.0 75.0

[0101] It can be seen from the results in Table 1 that the thermal insulation coatings prepared in Examples 1-3 have low transmittance, which makes them have better thermal insulation effect.

[0102] Compared with Example 1, in Examples 4-5, the molar ratio of diphenol propane and epichlorohydrin, and the mass ratio of bisphenol A epoxy resin and polyurethane modified epoxy resin were changed respectively when preparing the modified epoxy resin. Example 4 increased the viscosity of the formed bisphenol A epoxy resin and reduced the epoxy content. Example 5 increased the viscosity of the modified epoxy resin, affecting the uniformity of the final coating. Compared with Example 1, Comparative Example 1 used an equal amount of commercially available bisphenol A epoxy resin to replace modified epoxy resin A, which had poor transparency and reduced epoxy content. Although the above examples or comparative examples had no significant effect on the transmittance at 365nm and the transmittance at 950nm, they would reduce the visible light transmittance.

[0103] Compared with Example 1, in the preparation of the modified UV absorber, the molar ratio of 1-allyl-3-chloro-5-fluorobenzene and N-dodecylglycine, the molar ratio of the intermediate and 3-(3-hydroxy-3-methylbutane)-2,4,6-trihydroxybenzophenone were changed respectively, and the UV absorption capacity was weakened; similarly, in Comparative Example 2, compared with Example 1, an equal amount of 2,4-dihydroxybenzophenone was used to replace the modified UV absorber A, which affected the anti-ultraviolet performance. The above embodiments or comparative examples have no obvious effect on the transmittance at 950nm and the visible light transmittance, but increase the transmittance at 365nm.

[0104] Compared with Example 1, Example 8 changes the solvent in the cesium tungsten oxide slurry, so that the cesium tungsten oxide powder is unevenly dispersed, the transmittance at 950nm is increased, and the transmittance at 365nm and the visible light transmittance are not significantly affected.

[0105] The above is only a preferred embodiment of the present invention and does not constitute any form of limitation to the present application. Although the present application is disclosed as above in the preferred embodiment, it is not intended to limit the present application. Any technician familiar with the profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution.

Claims

1. A thermal insulation coating based on cesium tungsten oxide, characterized in that: The thermal insulation coating comprises the following raw materials by weight: 25-40 parts of modified epoxy resin, 15-25 parts of cesium tungsten oxide slurry, 6-10 parts of film-forming aid, 2-6 parts of modified ultraviolet absorber, 0.5-1 parts of defoamer, 1-2 parts of dispersant, and 0.8-2 parts of curing agent; The cesium tungsten oxide slurry comprises the following raw materials by weight: 30-40 parts of cesium tungsten oxide powder, 45-70 parts of solvent, and 0.4-0.8 parts of composite silane coupling agent; The preparation method of the modified epoxy resin comprises the following steps: S1. Add diphenol propane and epichlorohydrin into a reaction kettle, heat in a water bath to 70-78°C, stir until diphenol propane is completely dissolved, reflux, and obtain a transparent liquid; S2. After the system is cooled to 60-68°C, add 0.25-0.4 g / ml of sodium hydroxide solution to the transparent liquid obtained in step S1, control the addition time to 3-4h, heat to 65-78°C, and continue the reaction for 1.5-2.5h to obtain an oily liquid; S3. The oily liquid obtained in step S2 is added to the mixed solvent for extraction, washed, the oil layers are combined, and rotary evaporated to obtain a bisphenol A epoxy resin; S4. In step S3, a polyurethane-modified epoxy resin is added to the bisphenol A epoxy resin obtained, and the mixture is blended to obtain a modified epoxy resin; The molar ratio of diphenol propane to epichlorohydrin in step S1 is 1:(8-10).

2. The thermal insulation coating based on cesium tungsten oxide according to claim 1, characterized in that: The mass ratio of the bisphenol A epoxy resin to the polyurethane modified epoxy resin in step S4 is (9-11):

1.

3. The thermal insulation coating based on cesium tungsten oxide according to claim 1, characterized in that: The preparation method of the modified ultraviolet absorber comprises the following steps: (1) Add 1-allyl-3-chloro-5-fluorobenzene, N-dodecylglycine, dimethyl sulfoxide and triethylamine to a reaction kettle, mix and stir for 30-60 minutes, add 10-15wt% sodium hydroxide solution, heat to 80-100°C, react for 3.5-4 hours, rotary evaporate, purify by column chromatography, and distill under reduced pressure to obtain an intermediate; (2) The intermediate obtained in step (1), 3-(3-hydroxy-3-methylbutyl)-2,4,6-trihydroxybenzophenone and dimethyl sulfoxide are added to a reaction kettle, an inert gas is introduced, the mixture is stirred for 30-60 min, a concentrated sulfuric acid solution is added, the temperature is raised to 100-120° C. and the mixture is reacted for 3-4 h, the mixture is cooled to room temperature, a sodium bicarbonate solution is added, the mixture is separated, the organic layer is taken and distilled under reduced pressure, and then purified by column chromatography and distilled under reduced pressure to obtain a modified ultraviolet absorber.

4. The thermal insulation coating based on cesium tungsten oxide according to claim 3 is characterized in that: The molar ratio of 1-allyl-3-chloro-5-fluorobenzene to N-dodecylglycine in step (1) is (1.05-1.2):

1.

5. The thermal insulation coating based on cesium tungsten oxide according to claim 3, characterized in that: The molar ratio of the intermediate and 3-(3-hydroxy-3-methylbutane)-2,4,6-trihydroxybenzophenone in step (2) is (1.1-2.2):

1.

6. The thermal insulation coating based on cesium tungsten oxide according to claim 1, characterized in that: In parts by weight, the solvent in the cesium tungsten oxide slurry is 40-60 parts of ethylene glycol butyl ether acetate, 2-6 parts of propylene glycol methyl ether, 1-3 parts of propylene glycol methyl ether acetate and 1-2 parts of ethylene glycol butyl ether.

7. A method for preparing a thermal insulation coating based on cesium tungsten oxide according to any one of claims 1 to 6, characterized in that: The following steps are included:

1. Mixing cesium tungsten oxide powder, solvent and composite silane coupling agent, and subjecting them to ball milling to obtain cesium tungsten oxide slurry; 2. Mechanically blend the cesium tungsten oxide slurry, modified epoxy resin, film-forming aid, modified ultraviolet absorber, defoamer, dispersant and curing agent prepared in step 1 to obtain a thermal insulation coating.

8. An application of a thermal insulation coating based on cesium tungsten oxide according to any one of claims 1 to 6, characterized in that: Used in glass curtain walls and building windows.