Self-layering colored low-emissivity coating and preparation method thereof

Abstract

The invention discloses a self-stratifying colored low-emissivity coating and a preparation method thereof, and belongs to the technical field of coating materials. The self-stratifying colored low-emissivity coating provided by the invention comprises a low-emissivity oil layer dispersion mixed solution and a pigment water layer mixed solution, the low-emissivity oil layer dispersion mixed liquid comprises flaky aluminum powder, a solvent A, a solvent B and a first adhesive; the pigment and water layer mixed solution comprises a pigment, a solvent C and a second adhesive. The self-stratifying colored low-emissivity coating provided by the invention can spontaneously form a unique double-layer structure after being sprayed, so that the labor cost and the application complexity are greatly reduced, and the self-stratifying colored low-emissivity coating provided by the invention is low in thermal emissivity (namely, intermediate infrared emissivity) and high in near-infrared reflectivity; and visible light with a required color can be selectively reflected, and the stability is excellent.

Description

Technical Field

[0001] The invention relates to the technical field of coating materials, and in particular to a self-stratified colorful low-emissivity coating and a preparation method thereof. Background Art

[0002] Energy shortages and excessive CO2 emissions are pressing global issues, highlighting the urgency of reducing energy consumption. In various environments, including buildings, transportation, storage, aquaculture and brewing, a considerable portion of energy is used for heating and cooling to maintain appropriate temperatures. Among various thermal regulation strategies, thermal insulation plays a vital role in improving energy efficiency by reducing radiant heat transfer. For example, in buildings, thermal insulation can effectively limit heat loss in winter and prevent heat gain in summer, thereby significantly reducing heating and cooling energy consumption. This insulation effect not only stabilizes indoor temperatures, but also reduces reliance on active heating and cooling systems, ultimately helping to save energy and reduce greenhouse gas emissions in different climates and application conditions.

[0003] Traditional thermal insulation materials are low thermal conductivity materials that have the ability to inhibit heat conduction. In order to achieve satisfactory thermal insulation effects, these materials are usually designed with high porosity to adsorb air and thus enhance thermal resistance. Depending on their working mechanism, materials with a thickness of several millimeters to several centimeters are usually required to achieve sufficient thermal insulation effects. In contrast, thinner low-emissivity materials achieve thermal insulation by changing the surface radiation properties. Their low emissivity (i.e., high reflectivity) can greatly reduce thermal radiation exchange, thereby enhancing the thermal insulation effect through radiation control.

[0004] Low-emissivity coatings are generally classified into two types: transparent and opaque, depending on their application. Transparent low-emissivity coatings are often used on windows to reflect infrared thermal radiation while allowing visible light to pass through, thereby improving energy efficiency without changing the appearance. Opaque coatings, on the other hand, usually present a metallic silver or gray appearance, which can lead to aesthetic limitations and potential light pollution. In many practical applications, aesthetic effects are as important as thermal performance, so there is an urgent need for colored low-emissivity coatings that combine effective thermal insulation with aesthetic effects.

[0005] To address this challenge, researchers have explored a number of approaches to coloring low-emissivity materials, such as surface modification, material blending, and lamination. However, the emissivity values ​​are not low enough to provide effective thermal insulation performance, and the resulting colors often do not meet people's aesthetic expectations.

[0006] Therefore, there is still an urgent need for a self-layered colored low-emissivity coating that is simple to operate, has low emissivity, and has good thermal insulation effects. Summary of the invention

[0007] Peng et al. (Y. Peng et al., "Colorful low- emissivity paints for spaceheating and cooling energy savings," Proceedings of the National Academy of Sciences of the United States of America 120(34), e2300856120 (2023). https: / / doi.org / 10.1073 / pnas.2300856120.) reported a colorful self-layered low-emissivity paint. However, it requires two independent spraying processes to form a double-layer structure, which increases labor costs and application complexity. The present invention adopts specific solvent A, specific solvent B, specific solvent C and the ratio of isopropanol to water in specific solvent C, and unexpectedly finds that the obtained coating can produce self-stratification phenomenon after spraying. After spraying, the low-emissivity oil layer dispersion mixed liquid and the pigment water layer mixed liquid of the coating are mutually immiscible due to different polarities, and are automatically stratified due to different densities, wherein the pigment water layer mixed liquid is in the upper layer, and the low-emissivity oil layer dispersion mixed liquid is in the lower layer. After the solvent evaporates, a double-layer coating is formed in which the pigment layer is in the upper layer and the aluminum layer is in the lower layer, which greatly reduces labor costs and application complexity, and has unexpected technical effects. In addition, the present invention adopts specific solvent A, specific solvent B, specific solvent C and the ratio of isopropanol to water in specific solvent C, and unexpectedly finds that its near-infrared reflectivity is high, the mid-infrared emissivity is low, and its high temperature, low temperature and light stability are excellent, which has unexpected technical effects.

[0008] In order to solve the above technical problems, the present invention provides the following technical solutions.

[0009] In a first aspect, the present invention provides a self-layering colored low-emissivity coating.

[0010] A self-stratified colored low-emissivity paint, comprising: a low-emissivity oil layer dispersion mixed liquid and a pigment water layer mixed liquid; The low-emissivity oil layer dispersion mixed liquid comprises: flaky aluminum powder, solvent A, solvent B and a first adhesive; The pigment-water layer mixed liquid comprises: pigment, solvent C and a second adhesive.

[0011] In some embodiments, the solvent A comprises at least one of tetrachloroethylene, dichloromethane, perfluorohexane and 1,1,2,2-tetrachloroethane. In some preferred embodiments, the solvent A is tetrachloroethylene.

[0012] In some embodiments, the solvent B comprises at least one of 1,1,2,2-tetrachloroethane and dichloromethane. In some preferred embodiments, the solvent B is 1,1,2,2-tetrachloroethane.

[0013] In some embodiments, the first adhesive comprises polyvinyl butyral. In some embodiments, the first adhesive is polyvinyl butyral.

[0014] In some embodiments, the solvent C includes isopropanol, ethanol, methanol or a mixed solvent of any alcohol solvent and water. In some preferred embodiments, the solvent C is isopropanol and water.

[0015] In some embodiments, the solvent C is isopropanol and water, and the volume ratio of the isopropanol and water is 3:1-1:3. In some embodiments, the solvent C is isopropanol and water, and the volume ratio of the isopropanol and water is 3:1, 3:2, 1:1, 2:3 or 1:3. In some embodiments, the solvent C is isopropanol and water, and the volume ratio of the isopropanol and water is 3:2-1:3.

[0016] In some embodiments, the second adhesive comprises at least one of polyvinyl alcohol, nitrile rubber or epoxy resin. In some preferred embodiments, the second adhesive is polyvinyl alcohol.

[0017] In some embodiments, the pigment comprises an inorganic pigment. In some embodiments, the pigment comprises at least one of Prussian blue, iron oxide, and goethite.

[0018] In some embodiments, the diameter of the flaky aluminum powder is 10 μm-120 μm. In some embodiments, the diameter of the flaky aluminum powder is 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm or 120 μm.

[0019] In some embodiments, 1 g of the flaky aluminum powder is mixed with 2.5 ml-10 ml of the solvent A. In some embodiments, 1 g of the flaky aluminum powder is mixed with 2.5 ml, 2.75 ml, 3 ml, 3.5 ml, 4 ml, 4.5 ml, 5 ml, 5.5 ml, 6 ml, 7 ml, 8 ml, 9 ml or 10 ml of the solvent A. In some embodiments, 1 g of the flaky aluminum powder is mixed with 2.75 ml-10 ml of the solvent A.

[0020] In some embodiments, 1 g of the first adhesive is mixed with 50 ml-150 ml of the solvent B. In some embodiments, 1 g of the first adhesive is mixed with 50 ml, 60 ml, 70 ml, 71 ml, 72 ml, 73 ml, 74 ml, 75 ml, 80 ml, 85 ml, 90 ml, 100 ml, 110 ml, 120 ml, 130 ml, 140 ml or 150 ml of the solvent B. In some embodiments, 73 ml-100 ml of the solvent B is mixed with 1 g of the first adhesive.

[0021] In some embodiments, the mass ratio of the first adhesive to the flaky aluminum powder is 1:20-1:500. In some embodiments, the mass ratio of the first adhesive to the flaky aluminum powder is 1:20, 1:30, 1:40, 1:50, 1:60, 1:70, 1:72, 1:73, 1.5:110, 1:74, 1:80, 1:81, 1:82, 1:83, 1:84, 1:85, 1:90, 1:100, 1:110, 1:120, 1:130, 1:140, 1:150, 1:200, 1:250, 1:300, 1:350, 1:400, 1:450 or 1:500. In some embodiments, the mass ratio of the first adhesive to the flaky aluminum powder is 1:20-1:500. In some embodiments, the mass ratio of the first adhesive to the flaky aluminum powder is 1.5:110-1:100. In some embodiments, the mass ratio of the first adhesive to the flaky aluminum powder is 1.5:110, 1:80 or 1:100.

[0022] In some embodiments, the mass ratio of the pigment to the flaky aluminum powder is 1:110-50:110. In some embodiments, the mass ratio of the pigment to the flaky aluminum powder is 1:110-5:110. In some embodiments, the mass ratio of the pigment to the flaky aluminum powder is 1:110, 2:110, 3:110, 3.3:110, 3.85:110, 4:110 or 5:110. In some embodiments, the mass ratio of the pigment to the flaky aluminum powder is 3.3:110-5:110.

[0023] In some embodiments, the volume ratio of the solvent C to the mass of the pigment is 0.6 ml: 1 mg-0.6 ml: 50 mg. In some embodiments, the volume ratio of the solvent C to the mass of the pigment is 0.6 ml: 1 mg, 0.6 ml: 2 mg, 0.6 ml: 3 mg, 0.6 ml: 4 mg, 0.6 ml: 5 mg, 0.6 ml: 6 mg, 0.6 ml: 7 mg, 0.6 ml: 8 mg, 0.6 ml: 9 mg, 0.6 ml: 10 mg, 0.6 ml: 15 mg, 0.6 ml: 20 mg, 0.6 ml: 25 mg, 0.6 ml: 30 mg, 0.6 ml: 35 mg, 0.6 ml: 40 mg, 0.6 ml: 45 mg or 0.6 ml: 50 mg. In some embodiments, the volume ratio of the solvent C to the mass of the pigment is 0.6 ml: 4 mg-0.6 ml: 7 mg.

[0024] In some embodiments, the ratio of the volume of the solvent C to the mass of the second adhesive is 0.6 ml:10 mg-0.6 ml:40 mg.

[0025] In some embodiments, the solvent A is tetrachloroethylene; the solvent B is 1,1,2,2-tetrachloroethane; the first adhesive is polyvinyl butyral, and the pigment includes at least one of Prussian blue, iron oxide and goethite; the solvent C is isopropyl alcohol and water; the second adhesive is polyvinyl alcohol; the volume ratio of isopropyl alcohol and water is 3:2-1:3; every 1 g of the mass of the flaky aluminum powder is mixed with 2.75 ml-10 ml of the solvent A; every 1 g of the first adhesive is mixed with 73 ml-100 ml of the solvent B; the mass ratio of the first adhesive to the flaky aluminum powder is 1.5:110-1:100; the mass ratio of the pigment to the flaky aluminum powder is 3.3:110-5:110; the ratio of the volume of the solvent C to the mass of the pigment is 0.6 ml:4 mg-0.6 ml:7 mg; the ratio of the volume of the solvent C to the mass of the second adhesive is 0.6 ml:10 mg-0.6 ml:40 mg.

[0026] In some embodiments, the solvent A is tetrachloroethylene; the solvent B is 1,1,2,2-tetrachloroethane; the first adhesive is polyvinyl butyral, and the pigment includes at least one of Prussian blue, iron oxide and goethite; the solvent C is isopropyl alcohol and water; the second adhesive is polyvinyl alcohol; the volume ratio of isopropyl alcohol and water is 1:1; every 1 g of the mass of the flaky aluminum powder is mixed with 5 ml of the solvent A; every 1 g of the first adhesive is mixed with 100 ml of the solvent B; the mass ratio of the first adhesive to the flaky aluminum powder is 1:100; the mass ratio of the pigment to the flaky aluminum powder is 5:110; the ratio of the volume of the solvent C to the mass of the pigment is 0.6 ml:5 mg; the ratio of the volume of the solvent C to the mass of the second adhesive is 0.6 ml:20 mg.

[0027] In some embodiments, the solvent A is tetrachloroethylene; the solvent B is 1,1,2,2-tetrachloroethane; the first adhesive is polyvinyl butyral, and the pigment includes at least one of Prussian blue, iron oxide and goethite; the solvent C is isopropyl alcohol and water; the second adhesive is polyvinyl alcohol; the volume ratio of isopropyl alcohol and water is 2:3; every 1 g of the mass of the flaky aluminum powder is mixed with 10 ml of the solvent A; every 1 g of the first adhesive is mixed with 73 ml of the solvent B; the mass ratio of the first adhesive to the flaky aluminum powder is 1.5:110; the mass ratio of the pigment to the flaky aluminum powder is 4:110; the ratio of the volume of the solvent C to the mass of the pigment is 0.6 ml:4 mg; the ratio of the volume of the solvent C to the mass of the second adhesive is 0.6 ml:10 mg.

[0028] In some embodiments, the solvent A is tetrachloroethylene; the solvent B is 1,1,2,2-tetrachloroethane; the first adhesive is polyvinyl butyral, and the pigment includes at least one of Prussian blue, iron oxide and goethite; the solvent C is isopropyl alcohol and water; the second adhesive is polyvinyl alcohol; the volume ratio of isopropyl alcohol and water is 3:2; every 1 g of the mass of the flaky aluminum powder is mixed with 2.75 ml-10 ml of the solvent A; every 1 g of the first adhesive is mixed with 75 ml of the solvent B; the mass ratio of the first adhesive to the flaky aluminum powder is 1:100; the mass ratio of the pigment to the flaky aluminum powder is 3.3:110; the ratio of the volume of the solvent C to the mass of the pigment is 0.6 ml:6 mg; the ratio of the volume of the solvent C to the mass of the second adhesive is 0.6 ml:30 mg.

[0029] In some embodiments, the solvent A is tetrachloroethylene; the solvent B is 1,1,2,2-tetrachloroethane; the first adhesive is polyvinyl butyral, and the pigment includes at least one of Prussian blue, iron oxide and goethite; the solvent C is isopropyl alcohol and water; the second adhesive is polyvinyl alcohol; the volume ratio of isopropyl alcohol and water is 1:3; every 1 g of the mass of the flaky aluminum powder is mixed with 5.5 ml of the solvent A; every 1 g of the first adhesive is mixed with 80 ml of the solvent B; the mass ratio of the first adhesive to the flaky aluminum powder is 1:80; the mass ratio of the pigment to the flaky aluminum powder is 3.85:110; the ratio of the volume of the solvent C to the mass of the pigment is 0.6 ml:7 mg; the ratio of the volume of the solvent C to the mass of the second adhesive is 0.6 ml:40 mg.

[0030] In a second aspect, the present invention provides a method for preparing the self-layering colored low-emissivity coating described in the first aspect.

[0031] A method for preparing the self-layering colored low-emissivity coating according to the first aspect comprises: (1) dissolving a first adhesive in solvent B to obtain a first adhesive solution; dissolving a second adhesive in a partial amount of solvent C to obtain a second adhesive solution; (2) mixing flaky aluminum powder, a first binder solution and a solvent A to obtain the low emissivity oil layer dispersion mixed solution; (3) mixing the pigment, the second binder solution and the remaining amount of solvent C to obtain the pigment-water layer mixture; (4) Mixing the low-emissivity oil layer dispersion mixture and the pigment water layer mixture to obtain the self-stratifying colored low-emissivity paint.

[0032] In some embodiments, the amount of solvent C in step (1) is 5 / 12 to 10 / 12 of the formula amount of solvent C. In some embodiments, the amount of solvent C in step (1) is 5 / 12, 6 / 12, 7 / 12, 8 / 12, 9 / 12, 4 / 5 or 10 / 12 of the formula amount of solvent C.

[0033] In a third aspect, the present invention provides a low-emissivity product or thermal insulation material.

[0034] In some embodiments, a low-emissivity article is coated on a surface of the self-layered colored low-emissivity coating described in the first aspect or the self-layered colored low-emissivity coating prepared by the preparation method described in the second aspect.

[0035] In some embodiments, a thermal insulation material is coated on its surface with the self-layered colored low-emissivity coating described in the first aspect or the self-layered colored low-emissivity coating prepared by the preparation method described in the second aspect. Beneficial Effects

[0036] Compared with the prior art, a certain technical solution of the present invention has at least one of the following beneficial technical effects: (1) The self-layering colored low-emissivity coating provided by the present invention can be spontaneously layered after spraying, wherein the pigment water layer mixture is in the upper layer and the low-emissivity oil layer dispersion mixture is in the lower layer. After the solvent evaporates, a double-layer coating is formed with the pigment layer in the upper layer and the aluminum layer in the lower layer, which greatly reduces labor costs and application complexity and has unexpected technical effects. In addition, the self-layering colored low-emissivity coating provided by the present invention can be self-layered to form a pigment layer and an aluminum layer after spraying, and the pigment layer covers the aluminum layer, forming an appearance of different colors according to different pigments, having excellent aesthetic effects, and avoiding a single metallic silver or gray appearance and light pollution caused by the metallic silver or gray appearance.

[0037] (2) The self-layered color low-emissivity paint provided by the present invention has a high near-infrared reflectivity. Under the sun exposure in summer, the high near-infrared reflectivity can reflect a large amount of near-infrared light, which is beneficial to reduce the absorption of solar heat by the object sprayed with the paint. At the same time, the self-layered color low-emissivity paint provided by the present invention has a low thermal emissivity (i.e., mid-infrared emissivity), which can prevent the heat of the surrounding environment from entering the interior of the object sprayed with the self-layered color low-emissivity paint provided by the present invention, thereby reducing the energy consumption for cooling. In winter, the low thermal emissivity (i.e., mid-infrared emissivity) helps to maintain the heat inside the object sprayed with the self-layered color low-emissivity paint provided by the present invention, prevents the heat from being lost to the external environment too quickly, and is beneficial to maintaining indoor heat, reducing heat loss and saving heating energy consumption.

[0038] (3) Compared with other solvents A (such as cyclohexane, acetone or xylene), the solvent A (such as tetrachloroethylene) provided by the present invention is conducive to the self-stratification phenomenon of the obtained coating, which has unexpected technical effects.

[0039] (4) Compared with other solvents A (such as cyclohexane, acetone or one of xylene), the solvent A (such as tetrachloroethylene) provided by the present invention is beneficial to reducing the mid-infrared (wavelength 4 μm - 16 μm) emissivity of the obtained coating and improving the near-infrared (wavelength 780 nm - 2000 nm) reflectivity of the obtained coating, which has unexpected technical effects.

[0040] (5) Compared with other solvents B (such as isopropanol, ethanol or acetone), the solvent B provided by the present invention (such as 1,1,2,2-tetrachloroethane) is conducive to the self-stratification phenomenon of the obtained coating, which has unexpected technical effects.

[0041] (6) Compared with other solvents B (such as isopropanol, ethanol or acetone), the solvent B provided by the present invention (such as 1,1,2,2-tetrachloroethane) is beneficial to reducing the mid-infrared (wavelength 4 μm - 16 μm) emissivity of the obtained coating and improving the near-infrared (wavelength 780 nm -2000 nm) reflectivity of the obtained coating, which has unexpected technical effects.

[0042] (7) Compared with other solvents C (such as isopropanol or acetone), the solvent C provided by the present invention (such as a mixed solvent of isopropanol and water) is conducive to the self-stratification phenomenon of the obtained coating, which has unexpected technical effects.

[0043] (8) Compared with other solvents C (such as water, isopropanol or acetone), the solvent C provided by the present invention (such as a mixed solvent of isopropanol and water) is beneficial to reducing the mid-infrared (wavelength 4μm - 16μm) emissivity of the obtained coating and improving the near-infrared (wavelength 780nm -2000nm) reflectivity of the obtained coating, which has unexpected technical effects.

[0044] (9) Compared with other volume ratios of isopropanol and water in solvent C (such as isopropanol: water (V:V) = 20:1-10:1), the volume ratio of isopropanol and water in solvent C provided by the present invention (such as isopropanol: water (V:V) = 3:2-1:3) is conducive to the self-stratification phenomenon of the obtained coating, which has unexpected technical effects.

[0045] (10) Compared with other volume ratios of isopropanol and water in solvent C (such as isopropanol:water (V:V) = 20:1-1:10), the volume ratio of isopropanol and water in solvent C provided by the present invention (such as isopropanol:water (V:V) = 3:2-1:3) is beneficial to reducing the mid-infrared (wavelength 4 μm - 16 μm) emissivity of the obtained coating and improving the near-infrared (wavelength 780nm -2000nm) reflectivity of the obtained coating, which has unexpected technical effects.

[0046] (11) Compared with other solvents A, the high temperature, low temperature and light stability of the mid-infrared (wavelength 4 μm - 16 μm) emissivity and the high temperature, low temperature and light stability of the near-infrared (wavelength 780 nm - 2000 nm) reflectivity of the coating obtained by using the solvent A provided by the present invention (such as tetrachloroethylene) are better, and have unexpected technical effects.

[0047] (12) Compared with other solvents B, the high temperature, low temperature and light stability of the mid-infrared (wavelength 4 μm - 16 μm) emissivity and the high temperature, low temperature and light stability of the near-infrared (wavelength 780 nm - 2000 nm) reflectivity of the coating obtained by using the solvent B provided by the present invention (such as 1,1,2,2-tetrachloroethane) are better, and have unexpected technical effects.

[0048] (13) Compared with other solvents C, the high temperature, low temperature and light stability of the mid-infrared (wavelength 4 μm - 16 μm) emissivity of the coating obtained by using the solvent C provided by the present invention (such as a mixed solvent of isopropanol and water) and the high temperature, low temperature and light stability of the near-infrared (wavelength 780 nm - 2000 nm) reflectivity of the coating obtained are better, which has unexpected technical effects.

[0049] (14) Compared with other volume ratios of isopropanol and water in solvent C, the high-temperature, low-temperature and light stability of the mid-infrared (wavelength 4 μm - 16 μm) emissivity of the coating obtained by using the volume ratio of isopropanol and water in solvent C provided by the present invention (such as isopropanol: water (V:V) = 3:2-1:3) and the high-temperature, low-temperature and light stability of the near-infrared (wavelength 780 nm -2000 nm) reflectivity of the coating obtained are better, which has unexpected technical effects.

[0050] (15) The self-stratified colored low-emissivity coating provided by the present invention is conducive to isolating the transfer of heat and has excellent thermal insulation performance.

[0051] Terminology Before describing the present invention in more detail, it should be understood that the present invention is not limited to the specific embodiments described herein, because such embodiments may vary. It should also be understood that the terms used herein are only used for the purpose of describing specific embodiments, and the terms are not used for limitation. Unless otherwise specified, all technical and scientific terms used herein have the same meanings generally understood by those skilled in the art. All publications and patents referenced herein are incorporated herein by reference in their entirety.

[0052] Where a numerical range is provided, it is understood that, unless the context clearly indicates otherwise, to one tenth of the unit of the lower limit, intervening values ​​between the upper and lower limits of the range and any other stated or intervening values ​​in the range are encompassed within the present invention. These smaller range limits may be independently included within the smaller range and are also encompassed within the present invention, subject to any specific exclusion of limitation within the range. Where the range includes one or both of the limits, the range excluding either or both of those including the limits is also encompassed within the present invention.

[0053] The term "wt%" means percent by weight.

[0054] In the following content, all numbers disclosed herein are approximate values, regardless of whether the words "about" or "approximately" are used. The value of each number may vary by 1%, 2%, 5%, 7%, 8%, 10%, 15% or 20%. Whenever a number with a value of N is disclosed, any number with a value of N+ / -1%, N+ / -2%, N+ / -3%, N+ / -5%, N+ / -7%, N+ / -8%, N+ / -10%, N+ / -15% or N+ / -20% will be explicitly disclosed, where "+ / -" means plus or minus.

[0055] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0056] The term “comprise” or “include” is an open expression, that is, including the contents specified in the present invention but not excluding other contents.

[0057] In the present invention, the term "sheet diameter" refers to the diameter corresponding to the circumscribed circle of the particle. This circumscribed circle can just contain the aluminum powder particle, and its diameter is used as a value to measure the sheet diameter.

[0058] The term "V:V" means volume ratio.

[0059] In the present invention, the ratio of volume to mass refers specifically to the ratio between the volume of the corresponding component in the coating and the mass of the corresponding component. This ratio is not used to limit the actual amount of the corresponding component in the coating. For example, when it is expressed as "the ratio of the volume of the solvent C to the mass of the second adhesive is 0.6 ml: 10 mg", it means that for every 0.6 ml of solvent C, 10 mg of the second adhesive needs to be added. However, this does not mean that the actual volume of the solvent C in the coating is fixed to 0.6 ml and the actual mass of the second adhesive is fixed to 10 mg.

[0060] "Prussian Blue" is a coordination compound, also known as Teng's Blue, ferric ferrocyanide, English name Prussian Blue, abbreviated as PB, the molecular formula is Fe4(Fe(CN)6)3.

[0061] The term "iron oxide" means ferric oxide.

[0062] The term "goethite" refers to α-FeOOH (i.e., α-type iron oxyhydroxide). DETAILED DESCRIPTION

[0063] The scheme of the present invention will be explained below in conjunction with the embodiments. It will be appreciated by those skilled in the art that the following embodiments are only used to illustrate the present invention and should not be considered as limiting the scope of the present invention. Where specific techniques or conditions are not indicated in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. The reagents or instruments used are not indicated by the manufacturer and are all conventional products that can be obtained commercially.

[0064] 1. Paint spraying method: Unless otherwise specified, the self-layering colored low-emissivity coatings of the following examples or the coatings of the comparative examples were sprayed according to the following operation: A 40 mm ☓ 50 mm ☓ 1 mm glass substrate was used, and it was rinsed with deionized water, ethanol and acetone in turn, and finally dried with nitrogen. The coating to be tested was shaken evenly, and then sprayed on the substrate by spraying; the pressure of the spray gun was set to 200 KPa, and a spray gun with a caliber of 0.5 mm (SIBONGD, S-CP2-0.5) was used. During the spraying process, the tip of the spray gun was about 0.1 m away from the substrate. After the coating was naturally dried, a coating with a total thickness of about 15 μm of the pigment layer and the aluminum layer was obtained.

[0065] 2. Mid-infrared reflectivity detection method: The test was carried out using a Fourier transform infrared spectrometer with an integrating sphere.

[0066] Instrument manufacturer and model: Thermo Fisher Scientific, USA, Nicolet iS50.

[0067] Integrating sphere: PIKE.

[0068] 3. Detection method of near infrared reflectivity: The test was carried out using a UV / visible / near-infrared spectrophotometer with an integrating sphere.

[0069] Instrument manufacturer and model: PerkinElmer, Lambda1050+.

[0070] Examples 1-4: Self-Laminated Colored Low Emissivity Coatings Recipe: See Table 1.

[0071] Table 1: Self-layering colored low emissivity coating formulation

[0072] Preparation method: (1) dissolving a first adhesive in solvent B to obtain a first adhesive solution; dissolving a second adhesive in five-sixths of the amount of solvent C to obtain a second adhesive solution; (2) mixing flaky aluminum powder, a first binder solution and a solvent A to obtain the low emissivity oil layer dispersion mixed solution; (3) mixing the pigment, the second binder solution and the remaining amount of solvent C to obtain the pigment-water layer mixture; (4) The low-emissivity oil layer dispersion mixed liquid and the pigment water layer mixed liquid are mixed, shaken, and ultrasonicated to obtain the self-stratified colored low-emissivity coating.

[0073] Example 5-Example 6: Self-layering colored low emissivity coatings with different pigments Based on the formulation and preparation method of Example 1, the Prussian blue was replaced with an equal mass of iron oxide to obtain the self-layering colored low-emissivity coating of Example 5.

[0074] Based on the formulation and preparation method of Example 1, the Prussian blue was replaced with an equal mass of goethite to obtain the self-stratified colored low-emissivity coating of Example 6.

[0075] Comparative Example 1-Comparative Example 3: Investigation of Solvent A The coatings of Comparative Examples 1 to 3 differ from those of Example 1 in that the types of solvent A are different, and the rest are the same as Example 1. The specific selection of solvent A for Comparative Examples 1 to 3 is shown in Table 2, and the coatings of Comparative Examples 1 to 3 are obtained.

[0076] Table 2: Investigation of Solvent A Comparative Example Solvent A Comparative Example 1 Cyclohexane Comparative Example 2 acetone Comparative Example 3 Xylene Comparative Examples 4-6: Investigation of Solvent B The coatings of Comparative Examples 4 to 6 differ from those of Example 1 in that the types of solvent B are different, and the rest are the same as Example 1. The specific selection of solvent B of Comparative Examples 4 to 6 is shown in Table 3, and the coatings of Comparative Examples 4 to 6 are obtained.

[0077] Table 3: Investigation of Solvent B Comparative Example Solvent B Comparative Example 4 Isopropyl alcohol Comparative Example 5 Ethanol Comparative Example 6 acetone Comparative Examples 7-9: Investigation of Solvent C The coatings of Comparative Examples 7 to 9 differ from those of Example 1 in that the types of solvent C are different, and the rest are the same as Example 1. The specific selection of solvent C of Comparative Examples 7 to 9 is shown in Table 4, and the coatings of Comparative Examples 7 to 9 are obtained.

[0078] Table 4: Investigation of solvent C Comparative Example Solvent C Comparative Example 7 water Comparative Example 8 Isopropyl alcohol Comparative Example 9 acetone Comparative Example 10-Comparative Example 12: Investigation of the ratio of isopropanol and water in solvent C The coatings of Comparative Examples 10 to 12 differ from those of Example 1 in that the ratio of isopropanol to water in solvent C is different, and the rest is the same as Example 1. The specific selection of the ratio of isopropanol to water in solvent C of Comparative Examples 7 to 9 is shown in Table 5, and the coatings of Comparative Examples 10 to 12 are obtained.

[0079] Table 5: Investigation of the ratio of isopropanol to water in solvent C Comparative Example Volume ratio of isopropyl alcohol to water (isopropyl alcohol:water (V:V)) Comparative Example 10 10:1 Comparative Example 11 20:1 Comparative Example 12 1:10 Test Example 1: Emissivity and reflectivity testing The self-stratified colored low-emissivity coating obtained in the above embodiment and the coating obtained in the comparative example were sprayed (sprayed according to the operation under the above “1. Coating spraying method”), and after drying to form a coating, the mid-infrared (wavelength 4 μm-16 μm) emissivity, near-infrared (wavelength 780 nm-2000 nm) reflectivity and self-stratification effect were detected. The test results are shown in Table 6.

[0080] Table 6: Emissivity and reflectivity test results coating Mid-infrared (wavelength 4 μm - 16 μm) emissivity Near infrared (wavelength 780 nm -2000 nm) reflectivity Whether it is self-stratified (whether the pigment layer is on the top and the aluminum layer is on the bottom) Example 1 0.107 0.892 yes Example 2 0.121 0.773 yes Example 3 0.105 0.786 yes Example 4 0.138 0.771 yes Example 5 0.160 0.840 yes Example 6 0.139 0.863 yes Comparative Example 1 0.285 0.765 no Comparative Example 2 0.396 0.705 no Comparative Example 3 0.151 0.891 no Comparative Example 4 0.370 0.712 no Comparative Example 5 0.349 0.709 no Comparative Example 6 0.325 0.695 no Comparative Example 7 0.285 0.689 yes Comparative Example 8 0.378 0.714 no Comparative Example 9 0.347 0.769 no Comparative Example 10 0.327 0.701 no Comparative Example 11 0.374 0.652 no Comparative Example 12 0.276 0.716 yes Result analysis: (1) Compared with other solvents A (such as cyclohexane (Comparative Example 1), acetone (Comparative Example 2) or xylene (Comparative Example 3)), the use of solvent A provided by the present invention (such as tetrachloroethylene in Examples 1 to 6) is conducive to the self-stratification phenomenon of the obtained coating, which has unexpected technical effects.

[0081] (2) Compared with other solvents A (such as cyclohexane (Comparative Example 1), acetone (Comparative Example 2) or xylene (Comparative Example 3)), the solvent A provided by the present invention (such as tetrachloroethylene in Examples 1 to 6) is beneficial to reducing the mid-infrared (wavelength 4 μm - 16 μm) emissivity of the obtained coating and improving the near-infrared (wavelength 780 nm - 2000 nm) reflectivity of the obtained coating, which has unexpected technical effects.

[0082] (3) Compared with other solvents B (such as isopropanol (Comparative Example 4), ethanol (Comparative Example 5) or acetone (Comparative Example 6)), the use of the solvent B provided by the present invention (such as 1,1,2,2-tetrachloroethane in Examples 1 to 6) is conducive to the self-stratification phenomenon of the obtained coating, which has unexpected technical effects.

[0083] (4) Compared with other solvents B (such as isopropanol (Comparative Example 4), ethanol (Comparative Example 5) or acetone (Comparative Example 6)), the use of the solvent B provided by the present invention (such as 1,1,2,2-tetrachloroethane in Examples 1 to 6) is beneficial to reducing the mid-infrared (wavelength 4 μm - 16 μm) emissivity of the obtained coating and improving the near-infrared (wavelength 780 nm - 2000 nm) reflectivity of the obtained coating, which has unexpected technical effects.

[0084] (5) Compared with other solvents C (such as isopropyl alcohol (Comparative Example 8) or acetone (Comparative Example 9)), the use of the solvent C provided by the present invention (such as isopropyl alcohol and water in Examples 1 to 4) is conducive to the self-stratification phenomenon of the obtained coating, which has unexpected technical effects.

[0085] (6) Compared with other solvents C (such as water (Comparative Example 7), isopropanol (Comparative Example 8) or acetone (Comparative Example 9)), the use of the solvent C provided by the present invention (such as isopropanol and water in Examples 1 to 6) is beneficial to reducing the mid-infrared (wavelength 4 μm - 16 μm) emissivity of the obtained coating and improving the near-infrared (wavelength 780 nm - 2000 nm) reflectivity of the obtained coating, which has unexpected technical effects.

[0086] (7) Compared with other volume ratios of isopropanol and water in solvent C (such as isopropanol:water (V:V) = 20:1-10:1 (Comparative Example 10-Comparative Example 11)), the volume ratio of isopropanol and water in solvent C provided by the present invention (such as isopropanol:water (V:V) = 3:2-1:3 in Examples 1-6) is conducive to the self-stratification phenomenon of the obtained coating, which has unexpected technical effects.

[0087] (8) Compared with other volume ratios of isopropanol and water in solvent C (such as isopropanol:water (V:V) = 20:1-1:10 (Comparative Examples 10-13)), the volume ratio of isopropanol and water in solvent C provided by the present invention (such as isopropanol:water (V:V) = 3:2-1:3 in Examples 1-6) is beneficial to reducing the mid-infrared (wavelength 4 μm - 16 μm) emissivity of the obtained coating and improving the near-infrared (wavelength 780 nm - 2000 nm) reflectivity of the obtained coating, which has unexpected technical effects.

[0088] Test Example 2: Stability Study 1. High temperature stability The self-layered colored low-emissivity coatings obtained in the above examples and the coatings obtained in the comparative examples were sprayed according to the operation under the above “I. Coating Spraying Method”. After drying to form a coating, the mid-infrared (wavelength 4 μm - 16 μm) emissivity and the near-infrared (wavelength 780 nm - 2000 nm) reflectivity were detected. Then, they were placed under high temperature (80°C) conditions for 6 months, and the mid-infrared (wavelength 4 μm - 16 μm) emissivity and the near-infrared (wavelength 780 nm - 2000 nm) reflectivity were detected. The results are shown in Table 7.

[0089] Table 7: Stability study at high temperature (80°C) for 6 months coating Mid-infrared (wavelength 4 μm - 16 μm) emissivity Near infrared (wavelength 780 nm -2000 nm) reflectivity Example 1 - Before placing under high temperature conditions 0.106 0.893 Example 2 - Before exposure to high temperature conditions 0.122 0.772 Example 3 - Before exposure to high temperature 0.104 0.785 Example 4 - Before exposure to high temperature 0.137 0.772 Example 5 - Before placing under high temperature conditions 0.160 0.841 Example 6 - Before exposure to high temperature conditions 0.139 0.864 Comparative Example 2-Before placing under high temperature conditions 0.396 0.704 Comparative Example 8-Before placing under high temperature conditions 0.377 0.715 Comparative Example 12-Before placing under high temperature conditions 0.277 0.715 Example 1 High temperature for 6 months 0.109 0.892 Example 2 High temperature for 6 months 0.123 0.772 Example 3 High temperature for 6 months 0.109 0.781 Example 4 High temperature for 6 months 0.141 0.765 Example 5 High temperature for 6 months 0.162 0.838 Example 6 High temperature for 6 months 0.140 0.860 Comparative Example 2 High temperature for 6 months 0.457 0.587 Comparative Example 8 High temperature for 6 months 0.478 0.592 Comparative Example 12 High temperature for 6 months 0.509 0.621 2. Low temperature stability The self-layered colored low-emissivity coatings obtained in the above embodiments and the coatings obtained in the comparative examples were sprayed according to the operation under the above “I. Coating Spraying Method”. After drying to form a coating, the mid-infrared (wavelength 4 μm - 16 μm) emissivity and the near-infrared (wavelength 780 nm - 2000 nm) reflectivity were detected. Then, the coatings were placed at low temperature (-20°C) for 6 months, and the mid-infrared (wavelength 4 μm - 16 μm) emissivity and the near-infrared (wavelength 780 nm - 2000 nm) reflectivity were detected. The results are shown in Table 8.

[0090] Table 8: 6-month stability study at low temperature (-20°C) coating Mid-infrared (wavelength 4 μm - 16 μm) emissivity Near infrared (wavelength 780 nm -2000 nm) reflectivity Example 1 - Before placing under low temperature conditions 0.107 0.893 Example 2 - Before placing under low temperature conditions 0.121 0.772 Example 3 - Before placing under low temperature conditions 0.104 0.786 Example 4 - Before placing under low temperature conditions 0.138 0.772 Example 5 - Before placing under low temperature conditions 0.161 0.840 Example 6 - Before placing under low temperature conditions 0.138 0.865 Comparative Example 2-Before placing under low temperature conditions 0.395 0.705 Comparative Example 8-Before placing under low temperature conditions 0.378 0.713 Comparative Example 12-Before placing under low temperature conditions 0.275 0.717 Example 1 Low temperature for 6 months 0.107 0.892 Example 2 Low temperature for 6 months 0.122 0.773 Example 3 Low temperature for 6 months 0.108 0.786 Example 4 Low temperature for 6 months 0.139 0.770 Example 5 Low temperature for 6 months 0.161 0.839 Example 6 Low temperature for 6 months 0.140 0.858 Comparative Example 2 Low temperature for 6 months 0.431 0.684 Comparative Example 8 Low temperature for 6 months 0.458 0.612 Comparative Example 12 Low temperature for 6 months 0.341 0.598 3. Light stability The self-layered colored low-emissivity coating obtained in the above embodiment and the coating obtained in the comparative example were sprayed according to the operation under the above "I. Coating Spraying Method". After drying to form a coating, the mid-infrared (wavelength 4 μm - 16 μm) emissivity and near-infrared (wavelength 780 nm - 2000 nm) reflectivity were detected, and then an ultraviolet lamp (350 mW / cm 2 ) for 6 months, and the mid-infrared (wavelength 4 μm - 16 μm) emissivity and near-infrared (wavelength 780 nm -2000nm) reflectivity were tested. The results are shown in Table 9.

[0091] Table 9: UV lamp (350 mW / cm 2 ) 6 months stability test coating Mid-infrared (wavelength 4 μm - 16 μm) emissivity Near infrared (wavelength 780 nm -2000 nm) reflectivity Example 1 - Before placing under UV light irradiation conditions 0.108 0.891 Example 2 - Before placing under UV light irradiation conditions 0.120 0.771 Example 3 - Before placing under UV light irradiation conditions 0.103 0.787 Example 4 - Before placing under UV light irradiation conditions 0.139 0.771 Example 5 - Before placing under UV light irradiation conditions 0.161 0.841 Example 6 - Before placing under UV light irradiation conditions 0.139 0.865 Comparative Example 2-Before UV Light Irradiation Conditions 0.396 0.704 Comparative Example 8-Before UV Light Irradiation Conditions 0.378 0.715 Comparative Example 12-Before UV Light Irradiation Conditions 0.275 0.716 Example 1 UV light irradiation for 6 months 0.110 0.890 Example 2 UV light irradiation for 6 months 0.126 0.771 Example 3 UV light irradiation for 6 months 0.111 0.779 Example 4 UV light irradiation for 6 months 0.139 0.769 Example 5 UV light irradiation for 6 months 0.163 0.836 Example 6 UV light irradiation for 6 months 0.143 0.857 Comparative Example 2 UV light irradiation for 6 months 0.554 0.603 Comparative Example 8 UV light irradiation for 6 months 0.567 0.612 Comparative Example 12 UV light irradiation for 6 months 0.454 0.517 in conclusion: (1) Compared with other solvents A, the high temperature, low temperature and light stability of the mid-infrared (wavelength 4 μm - 16 μm) emissivity of the coating obtained by using the solvent A provided by the present invention (such as tetrachloroethylene in Examples 1 to 6) and the high temperature, low temperature and light stability of the near-infrared (wavelength 780 nm - 2000 nm) reflectivity of the coating obtained are more excellent, and have unexpected technical effects.

[0092] (2) Compared with other solvents B, the high temperature, low temperature and light stability of the mid-infrared (wavelength 4 μm - 16 μm) emissivity of the coating obtained by using the solvent B provided by the present invention (such as 1,1,2,2-tetrachloroethane in Examples 1 to 6) and the high temperature, low temperature and light stability of the near-infrared (wavelength 780 nm - 2000 nm) reflectivity of the coating obtained are more excellent, with unexpected technical effects.

[0093] (3) Compared with other solvents C, the high temperature, low temperature and light stability of the mid-infrared (wavelength 4 μm - 16 μm) emissivity of the coating obtained by using the solvent C provided by the present invention (such as isopropyl alcohol and water in Examples 1 to 6) and the high temperature, low temperature and light stability of the near-infrared (wavelength 780 nm - 2000 nm) reflectivity of the coating obtained are more excellent, with unexpected technical effects.

[0094] (4) Compared with other volume ratios of isopropanol and water in solvent C, the high-temperature, low-temperature and light stability of the mid-infrared (wavelength 4 μm - 16 μm) emissivity of the coating obtained by using the volume ratio of isopropanol and water in solvent C provided by the present invention (such as isopropanol:water (V:V) = 3:2-1:3 in Examples 1-6) and the high-temperature, low-temperature and light stability of the near-infrared (wavelength 780 nm-2000 nm) reflectivity of the coating obtained are more excellent, with unexpected technical effects.

[0095] Test Example 3: Ice cream melting test (heat insulation performance test) Ice cubes: Add water containing blue food-grade pigment to ice cream molds, freeze them in a -20 ℃ refrigerator for 2 days, and then demold them as ice cubes used in this experiment. The initial weight of the ice cubes was about 18 grams.

[0096] Ice cubes of the same mass (about 18 g) were placed in a cubic glass box with the inner surface, outer surface, or inner and outer surfaces coated with the same thickness of layered colored low-emissivity paint obtained in different embodiments or commercial red paint, or without any paint, and the bottom was isolated by an insulating board. They were placed at 24°C for 1 hour, and the melted mass of the ice cubes was measured. The results are shown in Table 10.

[0097] Table 10: Thermal insulation performance investigation Conclusion: The self-stratified colored low-emissivity coating provided by the present invention is conducive to isolating the transfer of heat and has excellent thermal insulation performance.

[0098] The method of the present invention has been described through preferred embodiments, and relevant personnel can obviously modify or appropriately change and combine the methods and applications described herein within the content, spirit and scope of the present invention to implement and apply the technology of the present invention. Those skilled in the art can refer to the content of this article and appropriately improve the process parameters. It is particularly important to point out that all similar replacements and modifications are obvious to those skilled in the art, and they are all considered to be included in the present invention.

Claims

1. A self-layering colored low emissivity coating, characterized in that: include: A low emissivity oil layer dispersion mixed solution and a pigment water layer mixed solution; The low-emissivity oil layer dispersion mixed liquid comprises: flaky aluminum powder, solvent A, solvent B and a first adhesive; The pigment-water layer mixed liquid comprises: pigment, solvent C and a second adhesive.

2. The self-layering colored low-emissivity coating according to claim 1, wherein the solvent A comprises at least one of tetrachloroethylene, dichloromethane, perfluorohexane and 1,1,2,2-tetrachloroethane; preferably tetrachloroethylene; The solvent B comprises at least one of 1,1,2,2-tetrachloroethane and dichloromethane; preferably 1,1,2,2-tetrachloroethane; The first adhesive includes polyvinyl butyral.

3. The self-layering colored low-emissivity coating according to any one of claims 1 to 2, wherein the solvent C comprises isopropanol, ethanol, methanol or a mixed solvent of any alcohol solvent and water, preferably isopropanol and water; and / or The solvent C is isopropanol and water, and the volume ratio of the isopropanol to water is 3:1-1:3, or 3:1, or 1:1, or 2:3; and / or The second adhesive comprises at least one of polyvinyl alcohol, nitrile rubber or epoxy resin, preferably polyvinyl alcohol.

4. The self-layering colored low-emissivity coating according to any one of claims 1 to 3, wherein the pigment comprises an inorganic pigment; and / or The pigment includes at least one of Prussian blue, iron oxide, and goethite.

5. The self-stratifying colored low-emissivity coating according to any one of claims 1 to 4, wherein the flake diameter of the flaky aluminum powder is 10 μm to 120 μm.

6. The self-layering colored low-emissivity coating according to any one of claims 1 to 5, wherein 1 g of the flaky aluminum powder is mixed with 2.5 ml to 10 ml of the solvent A; and / or Each 1g of the first adhesive is mixed with 50ml-150ml of the solvent B; and / or The mass ratio of the first adhesive to the flaky aluminum powder is 1:20-1:500; and / or The mass ratio of the pigment to the flaky aluminum powder is 1:110-50:110; and / or The ratio of the volume of the solvent C to the mass of the pigment is 0.6 ml:1 mg-0.6 ml:50 mg or the ratio of the volume of the solvent C to the mass of the pigment is 0.6 ml:4 mg-0.6 ml:7 mg; and / or The ratio of the volume of the solvent C to the mass of the second adhesive is 0.6 ml:10 mg-0.6 ml:40 mg.

7. The self-layering colored low-emissivity coating according to any one of claims 1 to 6, characterized in that: The solvent A is tetrachloroethylene; the solvent B is 1,1,2,2-tetrachloroethane; the first adhesive is polyvinyl butyral, and the pigment includes at least one of Prussian blue, iron oxide and goethite; the solvent C is isopropyl alcohol and water; the second adhesive is polyvinyl alcohol; the volume ratio of isopropyl alcohol to water is 3:2-1:3; every 1 g of the mass of the flaky aluminum powder is mixed with 2.75 ml-10 ml of the solvent A; every 1 g of the first adhesive is mixed with 73 ml-100 ml of the solvent B; the mass ratio of the first adhesive to the flaky aluminum powder is 1.5:110-1:100; the mass ratio of the pigment to the flaky aluminum powder is 3.3:110-5:110; the ratio of the volume of the solvent C to the mass of the pigment is 0.6 ml:4 mg-0.6 ml:7 mg; the ratio of the volume of the solvent C to the mass of the second adhesive is 0.6 ml:10 mg-0.6 ml:40 mg; or The solvent A is tetrachloroethylene; the solvent B is 1,1,2,2-tetrachloroethane; the first adhesive is polyvinyl butyral, and the pigment includes at least one of Prussian blue, iron oxide and goethite; the solvent C is isopropyl alcohol and water; the second adhesive is polyvinyl alcohol; the volume ratio of isopropyl alcohol to water is 1:1; every 1 g of the mass of the flaky aluminum powder is mixed with 5 ml of the solvent A; every 1 g of the first adhesive is mixed with 100 ml of the solvent B; the mass ratio of the first adhesive to the flaky aluminum powder is 1:100; the mass ratio of the pigment to the flaky aluminum powder is 5:110; the ratio of the volume of the solvent C to the mass of the pigment is 0.6 ml:5 mg; the ratio of the volume of the solvent C to the mass of the second adhesive is 0.6 ml:20 mg; or The solvent A is tetrachloroethylene; the solvent B is 1,1,2,2-tetrachloroethane; the first adhesive is polyvinyl butyral, and the pigment includes at least one of Prussian blue, iron oxide and goethite; the solvent C is isopropyl alcohol and water; the second adhesive is polyvinyl alcohol; the volume ratio of isopropyl alcohol to water is 2:3; every 1g of the mass of the flaky aluminum powder is mixed with 10 ml of the solvent A; every 1g of the first adhesive is mixed with 73 ml of the solvent B; the mass ratio of the first adhesive to the flaky aluminum powder is 1.5:110; the mass ratio of the pigment to the flaky aluminum powder is 4:110; the ratio of the volume of the solvent C to the mass of the pigment is 0.6 ml:4 mg; the ratio of the volume of the solvent C to the mass of the second adhesive is 0.6 ml:10 mg; or The solvent A is tetrachloroethylene; the solvent B is 1,1,2,2-tetrachloroethane; the first adhesive is polyvinyl butyral, and the pigment includes at least one of Prussian blue, iron oxide and goethite; the solvent C is isopropyl alcohol and water; the second adhesive is polyvinyl alcohol; the volume ratio of isopropyl alcohol to water is 3:2; every 1 g of the mass of the flaky aluminum powder is mixed with 2.75 ml-10 ml of the solvent A; every 1 g of the first adhesive is mixed with 75 ml of the solvent B; the mass ratio of the first adhesive to the flaky aluminum powder is 1:100; the mass ratio of the pigment to the flaky aluminum powder is 3.3:110; the ratio of the volume of the solvent C to the mass of the pigment is 0.6 ml:6 mg; the ratio of the volume of the solvent C to the mass of the second adhesive is 0.6 ml:30 mg or The solvent A is tetrachloroethylene; the solvent B is 1,1,2,2-tetrachloroethane; the first adhesive is polyvinyl butyral, and the pigment includes at least one of Prussian blue, iron oxide and goethite; the solvent C is isopropyl alcohol and water; the second adhesive is polyvinyl alcohol; the volume ratio of isopropyl alcohol and water is 1:3; every 1g of the mass of the flaky aluminum powder is mixed with 5.5 ml of the solvent A; every 1g of the first adhesive is mixed with 80 ml of the solvent B; the mass ratio of the first adhesive to the flaky aluminum powder is 1:80; the mass ratio of the pigment to the flaky aluminum powder is 3.85:110; the ratio of the volume of the solvent C to the mass of the pigment is 0.6 ml:7 mg; the ratio of the volume of the solvent C to the mass of the second adhesive is 0.6 ml:40 mg.

8. A method for preparing the self-layering colored low-emissivity coating according to any one of claims 1 to 7, characterized in that: include: (1) dissolving a first binder in a solvent B to obtain a first binder solution; Dissolving the second adhesive in a portion of the solvent C to obtain a second adhesive solution; (2) mixing flaky aluminum powder, a first binder solution and a solvent A to obtain the low emissivity oil layer dispersion mixed solution; (3) mixing the pigment, the second binder solution and the remaining amount of solvent C to obtain the pigment-water layer mixture; (4) Mixing the low-emissivity oil layer dispersion mixture and the pigment water layer mixture to obtain the self-stratifying colored low-emissivity paint.

9. The preparation method according to claim 8, wherein the amount of solvent C added in step (1) is 5 / 12 to 10 / 12 of the formulated amount of solvent C.

10. A low emissivity product or thermal insulation material, characterized in that: The surface is coated with the self-layering colored low-emissivity coating according to any one of claims 1 to 7 or the self-layering colored low-emissivity coating prepared by the preparation method according to any one of claims 8 to 9.

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