Single-component sea gray water-based camouflage coating and preparation method thereof

Abstract

The invention relates to the technical field of infrared camouflage coatings, in particular to a single-component sea gray water-based camouflage coating and a preparation method thereof. The invention discloses a single-component sea gray water-based camouflage coating and a preparation method thereof, a white pigment of the camouflage coating uses infrared reflection titanium dioxide to replace part of conventional titanium dioxide, so that not only is the color displayed in a visible light region ensured, but also the reflectivity to sunlight in the visible light region and a near-infrared light region is improved; and the thermal radiation energy can be controlled from the temperature, so that the infrared emissivity is reduced. The inorganic pigment paste with different components and concentrations is used for toning, so that the coating can better adapt to the requirement of rich colors in different environments, not only has excellent aesthetic feeling in appearance, but also can meet the requirement of visible light camouflage compatibility visually.

Description

Technical Field

[0001] This invention relates to the field of infrared stealth coating technology, specifically to a single-component sea-gray water-based stealth coating and its preparation method. Background Technology

[0002] In modern reconnaissance technology, radar and infrared detection dominate. Infrared detection is widely used in reconnaissance and guidance due to its advantages such as all-weather capability, high precision, and strong anti-interference. Infrared detection is mainly based on the infrared radiation generated by the temperature of an object (above absolute zero). In the atmosphere, only three "atmospheric windows" of infrared radiation—0.76~1.5μm, 3~5μm, and 8~14μm—can propagate unimpeded. Among these, 8~14μm is the main band for thermal infrared imaging, and military infrared detection mostly employs imaging detection technology.

[0003] Traditional infrared stealth coatings are mostly solvent-based, releasing volatile organic solvents such as benzene and esters during application, resulting in high VOC content and posing health and environmental hazards. Existing water-based infrared stealth coatings are mostly two-component polyurethane systems, requiring the addition of isocyanate curing agents (toxic) and alcohol ether solvents and film-forming aids, leading to problems such as poor drying properties and low molecular weight. Pigments are crucial for infrared stealth: metallic pigments (such as aluminum silver paste) can reduce emissivity due to their flake-like structure (diameter-to-thickness ratio 40~100:1), but during dispersion, solvent evaporation easily generates Bénard vortices, resulting in poor aluminum flake alignment and decreased reflectivity; hollow glass microspheres, while reflecting sunlight (200~2500nm) and reducing infrared absorption, have poor hydrophilicity, easily floating and stratifying in water-based systems, thus compromising reflectivity; colored pigments need to also accommodate visible light camouflage (video stealth), but ordinary titanium dioxide is only suitable for light-colored systems, limiting its application in darker colors, and its infrared reflectivity is lower than visible light, hindering stealth; precipitated barium sulfate, while stable, has high density and insufficient hiding power, easily settling and penetrating the substrate.

[0004] Existing thermal infrared stealth coatings mostly achieve stealth by reducing surface emissivity, with little attention paid to controlling the target's own temperature.

[0005] Therefore, it is essential to develop a stealth coating that can reduce the infrared emissivity of a target while increasing the reflectivity in the visible light region, thus achieving both infrared and visible light stealth effects and meeting the requirements for camouflage such as sea gray. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention provides a single-component, sea-gray, water-based stealth coating and its preparation method. By using infrared-reflective titanium dioxide to replace part of the conventional titanium dioxide powder, it ensures color display in the visible light region while simultaneously improving the reflectivity of sunlight in both the visible and near-infrared regions. This allows for temperature-based control of thermal radiation energy, thereby reducing infrared emissivity. By using inorganic pigment pastes of different compositions and concentrations for color adjustment, the coating better adapts to the rich color requirements of various environments, possessing not only superior aesthetic appeal but also visually meeting the requirements for visible light camouflage compatibility.

[0007] This invention discloses a single-component sea-gray water-based stealth coating, which is composed of the following components in parts by weight: 75-85 parts of filler slurry; 10-14 parts of modified hollow glass microspheres; 10-14 parts of multi-colored paste; 11-15 parts of water-based aluminum silver paste; 5-15 parts of ethylene-vinyl acetate copolymer (EVA) wax; 70-80 parts of synthetic emulsion; 0.5-1.5 parts of leveling agent; 0.02-0.06 parts of thickener.

[0008] Preferably, the synthetic emulsion is an aqueous acrylate emulsion with a pH value of 6-8; the modified hollow glass microspheres have a particle size of 20-30 μm; the aluminum silver paste has a diameter of 0.1-10 μm; and the water is deionized water.

[0009] Preferably, the filler slurry is composed of 5-13 parts titanium dioxide, 5-13 parts infrared reflective titanium dioxide, 1 part barium sulfate, 0.5-2.5 parts dispersant, 0.1-0.5 parts defoamer, and 6-15.6 parts water.

[0010] Preferably, the multi-colored paste is composed of 1-5 parts of iron oxide yellow, 1-5 parts of iron oxide blue, 0.1-0.5 parts of dispersant, 0.01-0.05 parts of defoamer and 2-10 parts of water.

[0011] Preferably, the particle size of titanium dioxide is 280 nm; the particle size of infrared reflective titanium dioxide is 1.4 to 3.6 times that of titanium dioxide; and the mesh size of barium sulfate is 3000 mesh.

[0012] Preferably, the particle size of iron oxide blue is 50-150 nm; the particle size of iron oxide yellow is 80-150 nm.

[0013] This invention also discloses a method for preparing a single-component sea-gray water-based stealth coating, the method comprising the following steps: Preparation of S1 filler slurry: Add titanium dioxide, infrared reflective titanium dioxide, barium sulfate, dispersant, defoamer and water to grinding tank 1 in sequence. Then place grinding tank 1 in a basket mill, set the speed and time, filter with filter cloth after grinding, seal and use for later use. Preparation of S2 modified hollow glass microspheres: Add ethanol, silane coupling agent and hollow glass microspheres to dispersion tank 1 in sequence. Place dispersion tank 1 in a high-speed disperser, set the speed and time. After dispersion is completed, place it in a 90℃ vacuum drying oven and maintain the vacuum degree ≥0.08mpa. After 1.0h, seal it for later use. Preparation of S3 multicolor paste: Add iron oxide yellow, iron oxide blue, dispersant, defoamer and water to grinding tank 2 in sequence. Place grinding tank 2 in a basket mill. After grinding is completed, filter and seal for later use. Preparation of S4 finished coating: Add filler slurry, modified hollow glass microspheres, multi-colored paste, 220g water-based aluminum silver paste, ethylene-vinyl acetate copolymer, water-based acrylic emulsion, leveling agent and thickener to dispersion tank 2 in sequence. Place dispersion tank 2 in a high-speed disperser, set the speed and time, and filter after dispersion to obtain the finished coating.

[0014] Preferably, in the preparation step of the S1 filler slurry, the grinding mill rotates at 2000 r / min for 2 hours, and the filtration uses 320-mesh filter cloth.

[0015] Preferably, in the preparation step of the S2 modified hollow glass microsphere material, the mass ratio of the hollow glass microspheres, ethanol and silane coupling agent is 1:1:0.01; the speed of the disperser is 130 r / min and the time is 1 h.

[0016] Preferably, in the preparation step of the S4 finished coating, the speed of the disperser is 500 r / min and the time is 2 h.

[0017] Compared with the prior art, the beneficial effects of the present invention are: This invention aims to provide a novel infrared stealth coating and its preparation method. By supplementing the synergistic effect between the components, it overcomes the high reflectivity and low emissivity of the coating, achieving both infrared and visible light stealth, and breaking away from the methods of infrared stealth coatings with only one color and one method of suppressing thermal radiation.

[0018] Water-based aluminum silver paste is stable and inexpensive. Its flake-like appearance and large diameter-to-thickness ratio make it an ideal infrared emitting pigment. When dispersed on a carrier, the aluminum powder is parallel to the substrate. Numerous aluminum powder particles interconnect, with particles of varying sizes filling each other to form a continuous metallic film that both covers the substrate and reflects light from outside the coating. However, due to the Bernard vortex effect, the aluminum powder tumbles and cannot be neatly arranged. By adding ethylene-vinyl acetate copolymer, utilizing its unique hydrogen-bonded network, the entire system is in a coagulated state. Furthermore, its special anchoring effect on the flake-like structure constrains the movement and tumbling of the metallic pigment in the wet film, ensuring uniform dispersion and parallel arrangement of the aluminum powder pigment, thus improving the reflectivity. However, as an infrared stealth coating, its limited color options, while meeting the requirement of low infrared emissivity, cannot satisfy the visual camouflage needs of camouflage patterns.

[0019] Most coloring pigments do not reduce emissivity; they only require that the thermal stealth properties of the coating not be compromised. Coloring pigments can meet visible light camouflage requirements, achieving video stealth. Traditional titanium dioxide has a strong achromatic effect on colors, which cannot meet the needs of rich camouflage patterns. The infrared-reflective titanium dioxide introduced in this invention is between ordinary titanium dioxide and ideal infrared-reflective pigments. Due to its larger particle diameter, according to Weber's law, the ratio of particle diameter to the maximum reflection wavelength is approximately 1:2. By adding high-reflectivity infrared titanium dioxide, the reflectivity of the coating in the infrared region can be effectively improved, reducing thermal radiation energy. It does not absorb visible light, its reflectivity is adjustable, and its high infrared reflectivity reduces the achromatic effect of titanium dioxide. It can be used in medium and dark colors and is a universal ideal cool pigment suitable for different brightness levels of colors, improving TSR and NIR. When combined with ordinary rutile titanium dioxide, it can ensure the hiding power of the coating and allows for the selection of different proportions of the two titanium dioxides according to the depth and brightness of the color. Furthermore, by adding different formulations and concentrations of inorganic pigment pastes according to color requirements, different colored products can be obtained, achieving dual stealth in both visible light and infrared light. Adding precipitated barium sulfate and titanium dioxide at a mass ratio of 1:9 improves the weather resistance and corrosion resistance of the coating without affecting its storage stability and hiding power.

[0020] Neither single metallic pigments nor coloring pigments can achieve the versatility of stealth coatings. A solution that combines metallic pigments and special coloring pigments can achieve both infrared and visual stealth.

[0021] Hollow glass microspheres exhibit excellent reflectivity in the 200–2500 nm solar radiation band, effectively reducing infrared radiation absorption and providing thermal insulation. As an effective means of reducing infrared radiation characteristics, they work in conjunction with methods that apply low-infrared-emissivity coatings to object surfaces to effectively reduce the infrared radiation characteristics of those surfaces. The hollow glass microspheres used in this invention, after modification with a silane coupling agent, significantly increase the hydrophilicity of the inorganic particles, allowing them to be uniformly dispersed in the water-based coating system. Their thin-walled hollow spherical structure has a low thermal conductivity, and their tightly packed, multi-level arrangement within the coating forms a vacuum layer, providing strong reflection and blocking of solar radiation heat. Adding them to the coating system not only improves the mechanical properties of the coating but also effectively hinders heat transfer, weakens the temperature characteristics of the target surface, and ultimately reduces the infrared radiation intensity of the target.

[0022] Utilizing a high-molecular-weight water-emulsion resin, it possesses excellent mechanical properties, water resistance, and corrosion resistance. It eliminates the need for alcohol ether film-forming aids, reducing the evaporation of organic solvents. It dries quickly, cures at room temperature, and exhibits a high degree of cross-linking. It can be easily applied directly using spraying, roller coating, or brushing processes. Detailed Implementation

[0023] The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.

[0024] For experiments not specifically described in the examples, the procedures or conditions should be followed according to the conventional experimental procedures described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products.

[0025] Example 1: A single-component sea-gray water-based stealth coating, composed of the following parts by weight: 75 parts filler slurry; 10 parts modified hollow glass microspheres with a particle size of 20 μm; 10 parts multi-colored paste; 11 parts water-based aluminum silver paste with a diameter of 0.1 μm; 5 parts ethylene-vinyl acetate copolymer (EVA) wax; 70 parts synthetic emulsion, wherein the synthetic emulsion is a water-based acrylic emulsion with a pH value of 6; 0.5 parts leveling agent; 0.02 parts thickener.

[0026] A method for preparing a single-component sea-gray water-based stealth coating includes the following steps: Preparation of S1 filler slurry: Add 5 parts of titanium dioxide with a particle size of 280nm, 5 parts of infrared reflective titanium dioxide with a particle size of 400nm, 1 part of barium sulfate with a mesh size of 3000 mesh, 0.5 parts of dispersant, 0.1 parts of defoamer and 6 parts of deionized water to grinding tank 1 in sequence. Then place grinding tank 1 in a basket mill, set the speed to 2000r / min and the time to 2h. After grinding, filter with 320 mesh filter cloth, seal and use for later use.

[0027] Preparation of S2 modified hollow glass microspheres: Ethanol, silane coupling agent and hollow glass microspheres are added sequentially to dispersion tank 1, wherein the mass ratio of hollow glass microspheres, ethanol and silane coupling agent is 1:1:0.01; Dispersion tank 1 is placed in a high-speed disperser, the speed is set to 130 r / min and the time is 1 h. After dispersion is completed, it is placed in a 90℃ vacuum drying oven and the temperature is maintained at a vacuum degree ≥0.08 MPa. After maintaining the temperature for 1.0 h, it is sealed and used for later use.

[0028] Preparation of S3 multicolor paste: Add 1 part of iron oxide yellow with a particle size of 80nm, 5 parts of iron oxide blue with a particle size of 50nm, 0.1 part of dispersant, 0.01 part of defoamer and 2 parts of deionized water to grinding tank 2 in sequence. Place grinding tank 2 in a basket mill, set the speed to 2000r / min and the time to 2h. After grinding is completed, filter and seal for later use.

[0029] Preparation of S4 finished coating: Add 75 parts of filler slurry, 10 parts of modified hollow glass microspheres, 10 parts of multi-colored paste, 11 parts of water-based aluminum silver paste, 5 parts of ethylene-vinyl acetate copolymer, 70 parts of water-based acrylic emulsion, 0.5 parts of leveling agent, and 0.02 parts of thickener sequentially to dispersion tank 2. Place dispersion tank 2 in a high-speed disperser, set the speed to 500 r / min, and the time to 2 hours. After dispersion, filter to obtain the finished coating. The finished coating is a uniform liquid without lumps or coarse particles, and the color of the coating and paint film is uniform.

[0030] Example 2: A single-component sea-gray water-based stealth coating, composed of the following parts by weight: 77 parts of filler slurry; 11 parts of modified hollow glass microspheres with a particle size of 20 μm; 11 parts of multi-colored paste; 12 parts of water-based aluminum silver paste with a diameter of 0.1 μm; 7 parts of ethylene-vinyl acetate copolymer (EVA) wax; 72 parts of synthetic emulsion, wherein the synthetic emulsion is a water-based acrylic emulsion with a pH value of 6; 0.7 parts of leveling agent; 0.03 parts of thickener.

[0031] A method for preparing a single-component sea-gray water-based stealth coating includes the following steps: Preparation of S1 filler slurry: Add 7 parts of titanium dioxide with a particle size of 280nm, 7 parts of infrared reflective titanium dioxide with a particle size of 400nm, 1 part of barium sulfate with a mesh size of 3000 mesh, 0.9 parts of dispersant, 0.2 parts of defoamer and 8.4 parts of deionized water to grinding tank 1 in sequence. Then place grinding tank 1 in a basket mill, set the speed to 2000r / min and the time to 2h. After grinding, filter with 320 mesh filter cloth, seal and set for later use.

[0032] Preparation of S2 modified hollow glass microspheres: Ethanol, silane coupling agent and hollow glass microspheres are added sequentially to dispersion tank 1, wherein the mass ratio of hollow glass microspheres, ethanol and silane coupling agent is 1:1:0.01; Dispersion tank 1 is placed in a high-speed disperser, the speed is set to 130 r / min and the time is 1 h. After dispersion is completed, it is placed in a 90℃ vacuum drying oven and the temperature is maintained at a vacuum degree ≥0.08 MPa. After maintaining the temperature for 1.0 h, it is sealed and used for later use.

[0033] Preparation of S3 multicolor paste: Add 2 parts of iron oxide yellow with a particle size of 80nm, 4 parts of iron oxide blue with a particle size of 50nm, 0.2 parts of dispersant, 0.02 parts of defoamer and 4 parts of deionized water to grinding tank 2 in sequence. Place grinding tank 2 in a basket mill, set the speed to 2000r / min and the time to 2h. After grinding is completed, filter and seal for later use.

[0034] Preparation of S4 finished coating: Add 77 parts filler slurry, 11 parts modified hollow glass microspheres, 11 parts multi-colored paste, 12 parts water-based aluminum silver paste, 7 parts ethylene-vinyl acetate copolymer, 72 parts water-based acrylic emulsion, 0.7 parts leveling agent, and 0.03 parts thickener sequentially to dispersion tank 2. Place dispersion tank 2 in a high-speed disperser, set the speed to 500 r / min, and the time to 2 hours. After dispersion, filter to obtain the finished coating. The finished coating is a uniform liquid without lumps or coarse particles, and the color of the coating and paint film is uniform.

[0035] Example 3: A single-component sea-gray water-based stealth coating, composed of the following parts by weight: 80 parts of filler slurry; 12 parts of modified hollow glass microspheres with a particle size of 20 μm; 12 parts of multi-colored paste; 13 parts of water-based aluminum silver paste with a diameter of 0.1 μm; 10 parts of ethylene-vinyl acetate copolymer (EVA) wax; 75 parts of synthetic emulsion, wherein the synthetic emulsion is a water-based acrylic emulsion with a pH value of 6; 1 part of leveling agent; 0.04 parts of thickener.

[0036] A method for preparing a single-component sea-gray water-based stealth coating includes the following steps: Preparation of S1 filler slurry: Add 9 parts of titanium dioxide with a particle size of 280nm, 9 parts of infrared reflective titanium dioxide with a particle size of 400nm, 1 part of barium sulfate with a mesh size of 3000 mesh, 1.3 parts of dispersant, 0.3 parts of defoamer, and 10.8 parts of deionized water to grinding tank 1 in sequence. Then place grinding tank 1 in a basket mill, set the speed to 2000r / min, and the time to 2h. After grinding, filter with 320 mesh filter cloth, seal and set for later use.

[0037] Preparation of S2 modified hollow glass microspheres: Ethanol, silane coupling agent and hollow glass microspheres are added sequentially to dispersion tank 1, wherein the mass ratio of hollow glass microspheres, ethanol and silane coupling agent is 1:1:0.01; Dispersion tank 1 is placed in a high-speed disperser, the speed is set to 130 r / min and the time is 1 h. After dispersion is completed, it is placed in a 90℃ vacuum drying oven and the temperature is maintained at a vacuum degree ≥0.08 MPa. After maintaining the temperature for 1.0 h, it is sealed and used for later use.

[0038] Preparation of S3 multicolor paste: Add 3 parts of iron oxide yellow with a particle size of 80nm, 3 parts of iron oxide blue with a particle size of 50nm, 0.3 parts of dispersant, 0.03 parts of defoamer and 6 parts of deionized water to grinding tank 2 in sequence. Place grinding tank 2 in a basket mill, set the speed to 2000r / min and the time to 2h. After grinding is completed, filter and seal for later use.

[0039] Preparation of S4 finished coating: Add 80 parts of filler slurry, 12 parts of modified hollow glass microspheres, 12 parts of multi-colored paste, 13 parts of water-based aluminum silver paste, 9 parts of ethylene-vinyl acetate copolymer, 75 parts of water-based acrylic emulsion, 1 part of leveling agent, and 0.04 parts of thickener sequentially to dispersion tank 2. Place dispersion tank 2 in a high-speed disperser, set the speed to 500 r / min, and the time to 2 hours. After dispersion, filter to obtain the finished coating. The finished coating is a uniform liquid without lumps or coarse particles, and the color of the coating and paint film is uniform.

[0040] Example 4: A single-component sea-gray water-based stealth coating, composed of the following parts by weight: 82 parts of filler slurry; 13 parts of modified hollow glass microspheres with a particle size of 20 μm; 13 parts of multi-colored paste; 14 parts of water-based aluminum silver paste with a diameter of 0.1 μm; 12 parts of ethylene-vinyl acetate copolymer (EVA) wax; 77 parts of synthetic emulsion, wherein the synthetic emulsion is a water-based acrylic emulsion with a pH value of 6; 1.2 parts of leveling agent; and 0.05 parts of thickener.

[0041] A method for preparing a single-component sea-gray water-based stealth coating includes the following steps: Preparation of S1 filler slurry: Add 11 parts of titanium dioxide with a particle size of 280nm, 11 parts of infrared reflective titanium dioxide with a particle size of 400nm, 1 part of barium sulfate with a mesh size of 3000 mesh, 2.0 parts of dispersant, 0.4 parts of defoamer, and 12.1 parts of deionized water to grinding tank 1 in sequence. Then place grinding tank 1 in a basket mill, set the speed to 2000r / min, and the time to 2h. After grinding, filter with 320 mesh filter cloth, seal and set for later use.

[0042] Preparation of S2 modified hollow glass microspheres: Ethanol, silane coupling agent and hollow glass microspheres are added sequentially to dispersion tank 1, wherein the mass ratio of hollow glass microspheres, ethanol and silane coupling agent is 1:1:0.01; Dispersion tank 1 is placed in a high-speed disperser, the speed is set to 130 r / min and the time is 1 h. After dispersion is completed, it is placed in a 90℃ vacuum drying oven and the temperature is maintained at a vacuum degree ≥0.08 MPa. After maintaining the temperature for 1.0 h, it is sealed and used for later use.

[0043] Preparation of S3 multicolor paste: Add 4 parts of iron oxide yellow with a particle size of 80nm, 2 parts of iron oxide blue with a particle size of 50nm, 0.4 parts of dispersant, 0.04 parts of defoamer and 8 parts of deionized water to grinding tank 2 in sequence. Place grinding tank 2 in a basket mill, set the speed to 2000r / min and the time to 2h. After grinding is completed, filter and seal for later use.

[0044] Preparation of S4 finished coating: Add 82 parts of filler slurry, 13 parts of modified hollow glass microspheres, 13 parts of multi-colored paste, 14 parts of water-based aluminum silver paste, 11 parts of ethylene-vinyl acetate copolymer, 77 parts of water-based acrylic emulsion, 1.2 parts of leveling agent, and 0.05 parts of thickener sequentially to dispersion tank 2. Place dispersion tank 2 in a high-speed disperser, set the speed to 500 r / min, and the time to 2 hours. After dispersion, filter to obtain the finished coating. The finished coating is a uniform liquid without lumps or coarse particles, and the color of the coating and paint film is uniform.

[0045] Example 5: A single-component sea-gray water-based stealth coating, composed of the following parts by weight: 85 parts of filler slurry; 14 parts of modified hollow glass microspheres with a particle size of 20 μm; 14 parts of multi-colored paste; 15 parts of water-based aluminum silver paste with a diameter of 0.1 μm; 15 parts of ethylene-vinyl acetate copolymer (EVA) wax; 80 parts of synthetic emulsion, wherein the synthetic emulsion is a water-based acrylic emulsion with a pH value of 6; 1.5 parts of leveling agent; 0.06 parts of thickener.

[0046] A method for preparing a single-component sea-gray water-based stealth coating includes the following steps: Preparation of S1 filler slurry: Add 13 parts of titanium dioxide with a particle size of 280nm, 13 parts of infrared reflective titanium dioxide with a particle size of 400nm, 1 part of barium sulfate with a mesh size of 3000 mesh, 2.5 parts of dispersant, 0.5 parts of defoamer, and 15.6 parts of deionized water to grinding tank 1 in sequence. Then place grinding tank 1 in a basket mill, set the speed to 2000r / min, and the time to 2h. After grinding, filter with 320 mesh filter cloth, seal and set for later use.

[0047] Preparation of S2 modified hollow glass microspheres: Ethanol, silane coupling agent and hollow glass microspheres are added sequentially to dispersion tank 1, wherein the mass ratio of hollow glass microspheres, ethanol and silane coupling agent is 1:1:0.01; Dispersion tank 1 is placed in a high-speed disperser, the speed is set to 130 r / min and the time is 1 h. After dispersion is completed, it is placed in a 90℃ vacuum drying oven and the temperature is maintained at a vacuum degree ≥0.08 MPa. After maintaining the temperature for 1.0 h, it is sealed and used for later use.

[0048] Preparation of S3 multicolor paste: Add 5 parts of iron oxide yellow with a particle size of 80nm, 1 part of iron oxide blue with a particle size of 50nm, 0.5 parts of dispersant, 0.05 parts of defoamer and 10 parts of deionized water to grinding tank 2 in sequence. Place grinding tank 2 in a basket mill, set the speed to 2000r / min and the time to 2h. After grinding is completed, filter and seal for later use.

[0049] Preparation of S4 finished coating: Add 84 parts of filler slurry, 14 parts of modified hollow glass microspheres, 14 parts of multi-colored paste, 15 parts of water-based aluminum silver paste, 13 parts of ethylene-vinyl acetate copolymer, 79 parts of water-based acrylic emulsion, 1.4 parts of leveling agent, and 0.06 parts of thickener sequentially to dispersion tank 2. Place dispersion tank 2 in a high-speed disperser, set the speed to 500 r / min, and the time to 2 hours. After dispersion, filter to obtain the finished coating. The finished coating is a uniform liquid without lumps or coarse particles, and the color of the coating and paint film is uniform.

[0050] Example 6: In the preparation steps of S3 multi-color paste, no iron oxide yellow was added; the remaining steps and components were the same as in Example 3. The finished coating was a uniform liquid without lumps or coarse particles, and the color of the coating and paint film was bluish-green.

[0051] Comparative Example 1: In the preparation steps of S3 multi-color paste, iron oxide blue was not added; the remaining steps and components were the same as in Example 3. The finished coating was a uniform liquid without lumps or coarse particles, and the color of the coating and paint film was yellowish.

[0052] The properties of the finished coatings prepared in Examples 1-7 were tested, and the test data are shown in the table below:

[0053] As can be seen from the data in the table above, the core variables in Examples 1 to 5 are the increasing weight parts of filler slurry, modified hollow glass microspheres, multi-colored paste, water-based aluminum silver paste, EVA wax, and synthetic emulsion. In addition, the ratio of iron oxide yellow to iron oxide blue in the multi-colored paste is gradually adjusted from 1:5 to 5:1. Finally, in Example 3, the ratio of "3 parts yellow + 3 parts blue" is achieved. At the same time, the amount of each basic component is in the middle gradient (80 parts filler, 12 parts modified microspheres, and 75 parts synthetic emulsion), forming the optimal ratio.

[0054] Viscosity and workability: The viscosity of Examples 1-5 increased from 880 mcp.s to 980 mcp.s. The viscosity of Example 3 at 950 mcp.s can ensure both the stability of the coating (no layering) and the leveling properties of the coating. In Examples 4-5, due to the excessive amount of components, slight agglomeration occurred, resulting in a slight decrease in solid content (50.31%~49.95%) and a drop in water resistance from 14 days to 13 days.

[0055] Stealth performance (reflectivity + emissivity): Solar reflectivity (200~2500nm) is a key indicator of the coating's "visual stealth". Example 3 reached 0.61, indicating that it has the strongest ability to reflect sunlight, which can reduce the visual contrast between the target and the environment. Infrared emissivity (3~5μm, 8~14μm) is the core of "infrared stealth". The values ​​of 0.34 (3~5μm) and 0.51 (8~14μm) in Example 3 are the lowest, which means that it has the weakest ability to radiate infrared waves and is difficult to be identified by infrared detection equipment.

[0056] Mechanical properties and weather resistance: The adhesion (≤1 grade), impact resistance (≥50cm), and water resistance (no abnormalities after 14 days) of Example 3 were all optimal, indicating that at this component dosage, the filler and emulsion had the strongest bonding force, and the coating had the best toughness and water penetration resistance.

[0057] Examples 6 (without iron oxide yellow) and 7 (without iron oxide blue) are based on Example 3, but with the removal of one pigment component, the performance significantly decreased. The core reason is the synergistic effect of iron oxide yellow and iron oxide blue. Appearance and color uniformity: The absence of both leads to uneven color (6 is more blue and 7 is more yellow). Furthermore, due to the incomplete pigment system, the pigment dispersion decreases and the solar reflectance drops sharply (6 is 0.48 and 7 is 0.52), which greatly weakens the visual stealth effect.

[0058] Infrared stealth and weather resistance: The infrared emissivity is significantly increased (0.60 for 8~14μm and 0.43 for 3~5μm), and the water resistance is shortened to 10~12 days. This indicates that the two iron oxides are not only colorants, but can also optimize the microstructure of the coating through their own nanoparticle size (80nm for yellow and 50nm for blue), thereby improving infrared shielding and water resistance.

[0059] Example 8: The particle size of the modified hollow glass microspheres was changed (20μm, 22μm, 24μm, 26μm, 28μm, 30μm), while the remaining steps and raw materials were the same as in Example 3. The properties of the prepared coating were tested, and the test data are shown in the table below:

[0060] As can be seen from the data in the table above, Example 8 only changed the particle size of the modified hollow glass microspheres. The other raw material components (such as filler slurry, multi-colored paste, water-based aluminum silver paste, etc.) and preparation steps were completely consistent with Example 3. With "microsphere particle size" as the only variable (20μm→30μm), the performance showed the pattern of "gradual optimization → peak (26μm) → slow decay". The core reason is that the microsphere particle size affects the overall performance by regulating the coating's "particle compatibility", "micropore structure" and "interfacial bonding state".

[0061] Example 9: The diameter of the water-based aluminum silver paste was changed to (20μm, 30μm, 40μm, 50μm, 60μm, 70μm), and the particle size of the modified hollow glass microspheres was 26μm. The remaining steps and raw materials were the same as in Example 3. The properties of the prepared coating were tested.

[0062] Example 9 only changed the diameter of the water-based aluminum silver paste; the other raw material components (such as filler slurry, modified hollow glass microspheres of 26μm, multi-colored paste, etc.) and preparation steps were completely consistent with Example 8. The water-based aluminum silver paste consists of flake-shaped metal particles, and its diameter directly affects the coating's "dispersion, microstructure, optical properties, and mechanical bonding state." In Example 9, with the aluminum silver paste diameter as the only variable (20μm→70μm), the performance showed a pattern of "gradual optimization → peak (50μm) → gradual decay."

[0063] Example 10: The particle size of the infrared reflective titanium dioxide was changed to (400nm, 700nm, 1000nm), the particle size of the modified hollow glass microspheres was 26μm, and the diameter of the water-based aluminum silver paste was 8.1μm. The remaining steps and raw materials were the same as in Example 3. The properties of the prepared coating were tested, and the test data are shown in the table below:

[0064] As shown in the table above, Example 10 only changed the particle size of the infrared reflective titanium dioxide. Infrared reflective titanium dioxide is the core filler for the infrared stealth and light reflection functions of the coating, and its particle size directly affects the coating's "particle compatibility, infrared reflection efficiency, and mechanical bonding state". Example 10, with particle size as the only variable (400nm→1000nm), shows a performance trend of "optimization and improvement → peak value (1000nm)".

[0065] Example 11: The particle size of iron oxide yellow was changed to (80nm, 90nm, 105nm, 120nm, 135nm, 150nm), the particle size of modified hollow glass microspheres was 26μm, the particle size of infrared reflective titanium dioxide was 1000nm, and the diameter of water-based aluminum silver paste was 50μm. The remaining steps and raw materials were the same as in Example 3. The properties of the prepared coating were tested, and the test data are shown in the table below:

[0066] As shown in the table above, Example 11 only changed the particle size of iron oxide yellow. Iron oxide yellow is the core component for coloring the sea gray coating. Due to its nanoscale particle size, it also participates in regulating the dispersibility, microstructure, and optical synergistic properties of the coating. Example 11, with iron oxide yellow particle size as the only variable (80nm→150nm), exhibited a performance pattern of "continuous optimization → peak (120nm) → significant decay".

[0067] Example 12: The particle size of iron oxide blue was changed to (50nm, 70nm, 90nm, 110nm, 130nm, 150nm), the particle size of modified hollow glass microspheres was 26μm, the particle size of infrared reflective titanium dioxide was 1000nm, the diameter of water-based aluminum silver paste was 50μm, and the particle size of iron oxide yellow was 135nm. The remaining steps and raw materials were the same as in Example 3. The properties of the prepared coating were tested, and the test data are shown in the table below:

[0068] As shown in the table above, Example 12 only changed the particle size of the iron oxide blue. Iron oxide blue is the core coloring component for precise control of the sea gray tone of the coating. Its nanoparticle size not only determines the color balance, but also participates in the optimization of the coating's microstructure and stealth performance through "nanofilling" and "optical synergy". In Example 12, with the iron oxide blue particle size as the only variable (50nm→150nm), the performance showed a pattern of "gradual optimization → peak (110nm) → rapid decay".

[0069] Data from Examples 3 and 8-12 show that, through single-variable optimization in Examples 8-12, the optimal particle size / diameter parameters of the five core raw materials in the coating system were determined, ultimately forming a comprehensive optimized formula of "modified hollow glass microspheres 26μm + water-based aluminum silver paste 50μm + infrared reflective titanium dioxide 1000nm + iron oxide yellow 120nm + iron oxide blue 110nm". The performance of this comprehensive formula (such as infrared reflectivity, weather resistance, adhesion, color uniformity, and gloss) is significantly better than that of Example 3 (basic formula) and the experimental groups where each single variable did not reach its optimal value, proving that the optimal parameters of each core raw material are not effective in isolation, but rather form a "functional synergy".

[0070] Example 13: The pH of the synthetic emulsion was changed to (6, 6.3, 6.7, 7.1, 7.6, 8). The particle size of the modified hollow glass microspheres was 26 μm, the particle size of the infrared reflective titanium dioxide was 1000 nm, the diameter of the water-based aluminum silver paste was 50 μm, the particle size of the iron oxide yellow was 135 nm, and the particle size of the iron oxide blue was 130 nm. The remaining steps and raw materials were the same as in Example 3. The properties of the prepared coating were tested, and the test data are shown in the table below:

[0071] As can be seen from the data in the table above, Example 13 only changed the pH value of the synthetic emulsion. The pH value of the synthetic emulsion (aqueous acrylic emulsion) is the core parameter for regulating the stability, component compatibility and film-forming performance of the coating system. It affects the overall performance of the coating by influencing the surface charge of emulsion particles, pigment dispersion and film crosslinking efficiency.

[0072] In summary, the data from Examples 1-13 show that the single-component sea-gray waterborne stealth coating was gradually optimized using a single-factor variable method. First, Example 3 was determined as the base formulation through Examples 1-5, and then key parameters were optimized sequentially. Example 8 determined the optimal particle size of the modified hollow glass microspheres to be 26 μm; Example 9 determined the diameter of the waterborne aluminum silver paste to be 50 μm; Example 10 determined the infrared reflective titanium dioxide to be 1000 nm; Example 11 determined the iron oxide yellow to be 120 nm; Example 12 determined the iron oxide blue to be 110 nm; and Example 13 determined the pH of the synthetic emulsion to be 7.1, ultimately forming a closed-loop synergistic optimal formulation. The performance was significantly improved after optimization. Therefore, the preparation method provided by this invention forms a multi-level particle size gradient of "26 μm, 1000 nm, 50 μm, 120 nm, and 110 nm," with synergistic color matching of iron oxide yellow and blue at 120:110 nm, and the weakly neutral pH of the emulsion at 7.1 ensuring system stability. All parameters are synergistically optimized and none can be omitted.

[0073] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A single-component, sea-gray, water-based stealth coating, characterized in that, Composed of the following components by weight: 75-85 parts of filler slurry; 10-14 parts of modified hollow glass microspheres; 10-14 parts of multi-colored paste; 11-15 parts of water-based aluminum silver paste; 5-15 parts of ethylene-vinyl acetate copolymer wax; 70-80 parts of synthetic emulsion; 0.5-1.5 parts of leveling agent; 0.02-0.06 parts of thickener.

2. The single-component sea-gray water-based stealth coating according to claim 1, characterized in that, The synthetic emulsion is an aqueous acrylate emulsion with a pH of 6-8; the modified hollow glass microspheres have a particle size of 20-30 μm; the aluminum silver paste has a diameter of 20-70 μm; and the water is deionized water.

3. The single-component sea-gray water-based stealth coating according to claim 1, characterized in that, The filler slurry is composed of 5-13 parts titanium dioxide, 5-13 parts infrared reflective titanium dioxide, 1 part barium sulfate, 0.5-2.5 parts dispersant, 0.1-0.5 parts defoamer, and 6-15.6 parts water.

4. The single-component sea-gray water-based stealth coating according to claim 1, characterized in that, The multi-colored paste is composed of 1-5 parts of iron oxide yellow, 1-5 parts of iron oxide blue, 0.1-0.5 parts of dispersant, 0.01-0.05 parts of defoamer, and 2-10 parts of water.

5. The single-component sea-gray water-based stealth coating according to claim 3, characterized in that, The titanium dioxide has a particle size of 280 nm; the infrared reflective titanium dioxide has a particle size of 1.4 to 3.6 times that of the titanium dioxide; and the barium sulfate has a mesh size of 3000 mesh.

6. The single-component sea-gray water-based stealth coating according to claim 4, characterized in that, The particle size of the iron oxide blue is 50–150 nm; the particle size of the iron oxide yellow is 80–150 nm.

7. A method for preparing a single-component sea-gray water-based stealth coating, characterized in that, Includes the following steps: Preparation of S1 filler slurry: Add titanium dioxide, infrared reflective titanium dioxide, barium sulfate, dispersant, defoamer and water to grinding tank 1 in sequence. Then place grinding tank 1 in a basket mill, set the speed and time, filter with filter cloth after grinding, seal and use for later use. Preparation of S2 modified hollow glass microspheres: Add ethanol, silane coupling agent and hollow glass microspheres to dispersion tank 1 in sequence. Place dispersion tank 1 in a high-speed disperser, set the speed and time. After dispersion is completed, place it in a 90℃ vacuum drying oven and maintain the vacuum degree ≥0.08mpa. After 1.0h, seal it for later use. Preparation of S3 multicolor paste: Add iron oxide yellow, iron oxide blue, dispersant, defoamer and water to grinding tank 2 in sequence. Place grinding tank 2 in a basket mill. After grinding is completed, filter and seal for later use. Preparation of S4 finished coating: Add filler slurry, modified hollow glass microspheres, multi-colored paste, 220g water-based aluminum silver paste, EVA wax water-based acrylic emulsion, leveling agent and thickener to dispersion tank 2 in sequence. Place dispersion tank 2 in a high-speed disperser, set the speed and time, and filter after dispersion to obtain finished coating.

8. A method for preparing a single-component sea-gray water-based stealth coating according to claim 7, characterized in that, In the preparation step of the S1 filler slurry, the grinding mill rotates at 2000 r / min for 2 hours, and the filtration uses 320 mesh filter cloth.

9. The method for preparing a single-component sea-gray water-based stealth coating according to claim 7, characterized in that, In the preparation step of S2 modified hollow glass microspheres, the mass ratio of the hollow glass microspheres, ethanol and silane coupling agent is 1:1:0.01; the speed of the disperser is 130 r / min and the time is 1 h.

10. The method for preparing a single-component sea-gray water-based stealth coating according to claim 7, characterized in that, In the preparation step of the S4 finished coating, the speed of the disperser is 500 r / min and the time is 2 h.

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