Preparation method and application of broadleaf plant leaf imitating camouflage coating fabric

Abstract

The invention discloses a preparation method of a broadleaf plant leaf imitating camouflage coating fabric. The problem of compatibility of hyper-spectrum and thermal infrared camouflage is solved through the design of a multi-layer composite structure. The fabric is composed of a base fabric layer, a high-reflection layer, a hyper-spectral camouflage layer and a low-emissivity layer, wherein the high-reflection layer compensates near-infrared band absorption and maintains vegetation spectral characteristics; the hyperspectral camouflage layer simulates a spectral curve of a broad-leaved plant leaf in a 400-2500nm wave band, the fitting degree reaches 0.95 or above, and the GJB 1411A-2015 primary standard is met; the low-emissivity layer realizes 8-14 [mu] m band thermal infrared low emissivity while visible light is highly transparent, and the temperature difference between the low-emissivity layer and plant background radiation in a daily period is less than 5 DEG C. According to the method, near-infrared absorption of the silver nanowires is counteracted through optical path cooperative regulation and control, unification of visible light-near infrared high-precision vegetation imitation and thermal infrared stable camouflage is achieved, the environmental stability is good, humidity and heat resistance, high and low temperature resistance and mold resistance are achieved, the 60-degree glossiness of visible light is smaller than or equal to 5, and the full-time camouflage requirement of a complex battlefield is met.

Description

Technical Field

[0001] This invention belongs to the field of textile camouflage technology, specifically relating to a method for preparing and applying a camouflage coating fabric that imitates broadleaf plant leaves. Background Technology

[0002] With the rapid development of multispectral reconnaissance technology, modern military camouflage systems face the severe challenge of coordinated stealth across the entire visible, near-infrared, short-wave infrared, and thermal infrared spectrum. In modern battlefields, vegetated areas are crucial tactical concealment scenarios. Hyperspectral camouflage materials inspired by broadleaf plant leaves, through biomimetic micro-nano structure design, achieve active adaptation of spectral curves in the 400-2500nm wavelength range, effectively overcoming the spectral mismatch problem of traditional camouflage materials in complex backgrounds. Notably, the water contained within these materials undergoes a transpiration phase change under environmental thermal radiation. This process absorbs a large amount of latent heat, leading to a decrease in the material's surface temperature, unexpectedly endowing the material with passive thermal infrared stealth properties.

[0003] However, existing hyperspectral camouflage materials mimicking broadleaf plant leaves generally employ porous polymer matrices such as polyurethane foam and aerogel with an open porosity exceeding 80% to achieve lightweighting and spectral modulation. While these materials possess excellent spectral modulation capabilities and air permeability, their lightweight, porous structure leads to a rapid water evaporation rate and weak moisture retention, resulting in a short effective camouflage duration under high-temperature, dry environments. Although some studies have extended moisture retention time by applying a waterproof membrane to the surface of the camouflage material, this significantly reduces the material's moisture permeability, causing condensation to accumulate and impairing the spectral camouflage function.

[0004] Furthermore, current thermal infrared camouflage technologies mainly rely on two types of solutions: active cooling and passive reflection. The former, such as semiconductor cooling devices, can achieve low-temperature radiation control, but its high energy consumption significantly increases equipment load. The latter, such as metallic materials like aluminum foil, while possessing low emissivity, suffers from high visible light reflectivity, severely compromising the background blending effect required for hyperspectral camouflage. Silver nanowire networks with a diameter <500nm and a visible light transmittance >80% can effectively guarantee the underlying hyperspectral camouflage function, while their reflectivity >90% in the 8-14μm band endows them with low emissivity. However, current research has not effectively resolved the core contradiction in the synergy between spectral and thermal infrared camouflage performance: blending hyperspectral camouflage coatings with silver nanowires causes the material to lose its hyperspectral and emissivity control capabilities. If a highly transparent visible light silver nanowire is coated on the surface of the hyperspectral camouflage layer, the latter has some absorption in the near-infrared band, reducing near-infrared reflectivity and affecting hyperspectral camouflage performance. Therefore, there is an urgent need to develop a hyperspectral-thermal infrared compatible camouflage material that mimics the shape of broad-leaved plant leaves, possessing both spectral accuracy (0.4~2.5 μm full-band matching) and thermal infrared stealth properties, in order to meet the severe challenges of modern multi-band fusion reconnaissance systems. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a method for preparing and applying a camouflage coating fabric that mimics broadleaf plant leaves, solving the difficulty of achieving compatibility between hyperspectral and thermal infrared radiation, and meeting the need for stable camouflage across all time periods and multiple spectral bands in complex battlefield environments.

[0006] To address the aforementioned technical problems, embodiments of the present invention provide a method for preparing a camouflage coating fabric that mimics broadleaf plant leaves, comprising the following steps:

[0007] S1. Preparation of high-reflectivity coated fabric: Weigh a certain amount of adhesive and water, and add a certain amount of silicon dioxide, barium sulfate and titanium dioxide in sequence. Stir until uniform and free of particles to obtain a high-reflectivity coating. Use a coating machine to scrape the high-reflectivity coating onto the upper surface of the fabric, and bake at 130℃ for 2~3 minutes to obtain a high-reflectivity coated fabric.

[0008] S2. Preparation of hyperspectral camouflage coating fabric: A certain amount of dried MIL-101(Cr) was weighed into an inorganic salt solution of a certain concentration, stirred at room temperature for 1 hour, centrifuged to remove the lower precipitate, and dried at 140℃ for 12 hours to obtain the composite moisture-absorbing material M-MIL-101(Cr); A certain amount of M-MIL-101(Cr), inorganic pigment, binder, crosslinking agent, thickener and water were stirred until uniform to obtain hyperspectral camouflage coating; The hyperspectral camouflage coating was applied to the upper surface of the high-reflectivity coating fabric by coating method, and the color was fixed under a certain temperature to obtain the hyperspectral camouflage coating fabric imitating broad-leaved plant leaves;

[0009] S3. Preparation of hyperspectral-thermal infrared compatible camouflage coating fabric: Prepare a mixed solution of silver nanowire dispersion and crosslinking agent with a certain mass fraction, and spray it onto the upper surface of hyperspectral camouflage coating fabric that imitates broad-leaved plant leaves using a spray gun. Fix the color under certain temperature conditions to obtain hyperspectral-thermal infrared compatible camouflage coating fabric.

[0010] In step S1,

[0011] The mass ratio of silicon dioxide, barium sulfate, and titanium dioxide is (0.5~5):(10~20):(15~30).

[0012] The total mass of the high-reflectivity coating consists of three particles: silica, barium sulfate, and titanium dioxide, which together account for 15-50 wt%.

[0013] In step S1, the adhesive accounts for 20-40 wt% of the total mass of the high-reflectivity coating.

[0014] In step S2,

[0015] The specific surface area of ​​the porous hygroscopic material MIL-101(Cr) is ≥2500 m².2 / g, pore volume ≥0.20 cm³ 3 / g, the static water vapor adsorption capacity is ≥0.90g / g under the conditions of 25℃ and 65%RH;

[0016] The inorganic salt is one or a mixture of lithium chloride, calcium chloride, potassium chloride, or magnesium sulfate, with a concentration of 1-15 wt%.

[0017] The mass ratio of MIL-101(Cr) to inorganic salt is 1:(5~25);

[0018] M-MIL-101(Cr) accounts for 0.1~5 wt% of the total mass of the hyperspectral camouflage coating.

[0019] In step S2,

[0020] The crosslinking agent is one of GC-902, CX-100, ZS-1890, HD-3100A, TE3893, LOCTITE UK2015, and Sac-100, accounting for 1-10 wt% of the total mass of the hyperspectral camouflage coating;

[0021] Inorganic pigments include chrome green, iron yellow, iron red, and phthalocyanine blue, with a mass ratio of (30~35):(0.3~0.5):(1.0~2.0):(0.4~0.6).

[0022] The color-fixing temperature is 30~100℃, and the time is 1min~4h.

[0023] In step S3,

[0024] The average diameter of the silver nanowire dispersion is 5 nm to 500 nm, the average wire diameter is 5 to 15 μm, and the mass fraction of the silver nanowire dispersion is 3 to 10 wt%.

[0025] In step S3,

[0026] The crosslinking agent is one of GC-902, CX-100, ZS-1890, HD-3100A, TE3893, LOCTITE UK2015, and Sac-100, accounting for 0.1~0.5 wt% of the total mass of the mixed solution;

[0027] The color-fixing temperature is 30~50℃, and the time is 15min~4h;

[0028] The amount of silver nanowires used in hyperspectral-thermal infrared compatible camouflage coating fabrics is 1.0~5.0 g / m. 2 .

[0029] Preferably, the fabric used in step S1 is any one of chemical fibers and natural fibers, or a blend thereof.

[0030] The present invention also provides an application of the hyperspectral-thermal infrared compatible camouflage coating fabric for imitating broad-leaved plant leaves prepared by the above preparation method in the fields of hyperspectral / hyperspectral simulation and infrared camouflage.

[0031] The beneficial effects of the above technical solution of the present invention are as follows:

[0032] 1. This invention provides a hyperspectral-thermal infrared compatible camouflage coating fabric that mimics broadleaf plant leaves, pioneering a multispectral compatible camouflage system: through a three-level decoupled structure design of a base layer hyperspectral camouflage layer, a surface layer silver nanowire film, and a backing layer near-infrared reflective layer, it achieves for the first time a material ≥0.95 in spectral fit with broadleaf plant leaves in the 400~2500nm band (meeting the first-level standard of GJB 1411A-2015), while maintaining a stable low emissivity (diurnal periodic radiation temperature difference <5K) in the 8~14μm thermal infrared band, overcoming the challenge of compatibility between silver nanowire absorption characteristics and spectral camouflage.

[0033] 2. The hyperspectral-thermal infrared compatible camouflage coating fabric imitating broad-leaved plant leaves prepared by this invention has good environmental adaptability, excellent hyperspectral camouflage performance, and also has excellent resistance to damp heat (level 1), resistance to mildew (level 1) and wide temperature range stability (no brittleness at -20℃, no sticking at 50℃), and visible light 60° gloss ≤5, meeting the long-term deployment requirements of complex battlefield environments.

[0034] 3. The hyperspectral-thermal infrared compatible camouflage coating fabric for imitating broad-leaved plant leaves prepared by this invention has significant engineering application value. The three-layer optical path synergistic compensation mechanism effectively counteracts the near-infrared absorption of silver nanowires, ensuring camouflage effectiveness across the entire spectrum. It provides core technical support for hyperspectral simulation and infrared compatible camouflage equipment, and promotes the development of multispectral stealth technology towards engineering and practical application. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the structure of the present invention;

[0036] Figure 2 This is a reflection spectrum curve of Example 1 in the 400~2500nm band;

[0037] Figure 3 This is a reflection spectrum curve of Example 2 in the 400~2500nm band;

[0038] Figure 4 This is a reflection spectrum curve of Example 3 in the 400~2500nm band;

[0039] Figure 5 The reflectance spectrum of Comparative Example 1 in the 400~2500nm band;

[0040] Figure 6 Comparative Example 2: Reflectance spectrum curves in the 400~2500nm wavelength range;

[0041] Figure 7 Comparative Example 3: Reflectance spectrum curves in the 400~2500nm wavelength range;

[0042] Figure 8 Comparative Example 4: Reflectance spectrum curves in the 400~2500nm band. Detailed Implementation

[0043] To make the technical problems, technical solutions and advantages of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0044] This invention provides a camouflage coating that mimics broadleaf plant leaves, comprising a high-reflectivity coating and a hyperspectral camouflage coating, wherein,

[0045] The high-reflectivity coating comprises: binder, water, silica, barium sulfate, and titanium dioxide. The mass ratio of silica, barium sulfate, and titanium dioxide is (0.5~5):(10~20):(15~30). The total mass of silica, barium sulfate, and titanium dioxide accounts for 15~50 wt% of the total mass of the high-reflectivity coating. The binder accounts for 20~40 wt% of the total mass of the high-reflectivity coating.

[0046] The hyperspectral camouflage coating comprises: MIL-101(Cr), inorganic salt solution, inorganic pigment, binder, crosslinking agent, thickener and water, with an inorganic salt concentration of 1~15wt%; the mass ratio of MIL-101(Cr) to inorganic salt is 1:(5~25); M-MIL-101(Cr) accounts for 0.1~5wt% of the total mass of the hyperspectral camouflage coating.

[0047] The crosslinking agent is one of GC-902, CX-100, ZS-1890, HD-3100A, TE3893, LOCTITE UK2015 and Sac-100, accounting for 1~10wt% of the total mass of the hyperspectral camouflage coating; the inorganic pigments include chrome green, iron yellow, iron red and phthalocyanine blue, with a mass ratio of (30~35):(0.3~0.5):(1.0~2.0):(0.4~0.6).

[0048] An embodiment of the present invention provides a method for preparing a camouflage coating fabric that mimics broadleaf plant leaves, comprising the following steps:

[0049] S1. Preparation of high-reflectivity coated fabric: Weigh a certain amount of adhesive and water, and add a certain amount of silicon dioxide, barium sulfate and titanium dioxide in sequence. Stir until uniform and free of particles to obtain a high-reflectivity coating. Use a coating machine to scrape the high-reflectivity coating onto the upper surface of the fabric, and bake at 130℃ for 2~3 minutes to obtain a high-reflectivity coated fabric.

[0050] In step S1, the mass ratio of silica, barium sulfate, and titanium dioxide is (0.5~5):(10~20):(15~30); the total mass of silica, barium sulfate, and titanium dioxide accounts for 15~50 wt% of the total mass of the high-reflectivity coating; the binder accounts for 20~40 wt% of the total mass of the high-reflectivity coating.

[0051] S2. Preparation of hyperspectral camouflage coating fabric: A certain amount of dried MIL-101(Cr) was weighed into an inorganic salt solution of a certain concentration, stirred at room temperature for 1 hour, centrifuged to remove the lower precipitate, and dried at 140℃ for 12 hours to obtain composite moisture-absorbing material M-MIL-101(Cr); A certain amount of M-MIL-101(Cr), inorganic pigment, binder, crosslinking agent, thickener and water were stirred until uniform to obtain hyperspectral camouflage coating; The hyperspectral camouflage coating was applied to the upper surface of the high-reflectivity coating fabric by coating method, and the color was fixed under a certain temperature to obtain hyperspectral camouflage coating fabric imitating broad-leaved plant leaves.

[0052] In step S2, the specific surface area of ​​the porous hygroscopic material MIL-101(Cr) is ≥2500 m². 2 / g, pore volume ≥0.20 cm³ 3 / g, static water vapor adsorption capacity ≥0.90g / g under 25℃ and 65%RH conditions; inorganic salt is one or more of lithium chloride, calcium chloride, potassium chloride or magnesium sulfate, and inorganic salt concentration is 1~15wt%; mass ratio of MIL-101(Cr) to inorganic salt is 1:(5~25); M-MIL-101(Cr) accounts for 0.1~5wt% of the total mass of hyperspectral camouflage coating. The crosslinking agent is one of GC-902, CX-100, ZS-1890, HD-3100A, TE3893, LOCTITE UK2015 and Sac-100, accounting for 1~10wt% of the total mass of the hyperspectral camouflage coating; the inorganic pigments include chrome green, iron yellow, iron red and phthalocyanine blue, with a mass ratio of (30~35):(0.3~0.5):(1.0~2.0):(0.4~0.6); the baking and fixing temperature is 30~100℃, and the time is 1min~4h.

[0053] S3. Preparation of hyperspectral-thermal infrared compatible camouflage coating fabric: Prepare a mixed solution of silver nanowire dispersion and crosslinking agent with a certain mass fraction, and spray it onto the upper surface of hyperspectral camouflage coating fabric that imitates broad-leaved plant leaves using a spray gun. Fix the color under certain temperature conditions to obtain hyperspectral-thermal infrared compatible camouflage coating fabric.

[0054] In step S3, the average diameter of the silver nanowire dispersion is 5 nm to 500 nm, the average wire diameter is 5 to 15 μm, and the mass fraction of the silver nanowire dispersion is 3 to 10 wt%. The crosslinking agent is one of GC-902, CX-100, ZS-1890, HD-3100A, TE3893, LOCTITE UK2015, and Sac-100, accounting for 0.1 to 0.5 wt% of the total mass of the mixed solution; the fixing temperature is 30 to 50 °C, and the time is 15 min to 4 h; the amount of silver nanowires used in the hyperspectral-thermal infrared compatible camouflage coating fabric is 1.0 to 5.0 g / m². 2 .

[0055] In this invention, the fabric used in step S1 is any one of chemical fibers and natural fibers, or a blend thereof. It can be polyester, nylon, cotton, viscose, linen, or a combination thereof, or their blends.

[0056] The present invention also provides an application of the hyperspectral-thermal infrared compatible camouflage coating fabric for imitating broad-leaved plant leaves prepared by the above preparation method in the fields of hyperspectral / hyperspectral simulation and infrared camouflage.

[0057] The preferred embodiments of the present invention are described below. It should be understood that the embodiments are for better explanation of the present invention and are not intended to limit the present invention.

[0058] Test method:

[0059] 1. Spectral fit

[0060] The spectral reflectance of the hyperspectral camouflage coating fabric imitating broadleaf plant leaves was tested according to GJB 1082A-2021 "Colors for Camouflage Nets". A UV-Vis-NIR spectrophotometer was used to measure the spectral reflectance curves of the hyperspectral camouflage coating fabric imitating broadleaf plant leaves in the range of 0.4–2.5 μm (using a 2° field of view and a 1 nm wavelength interval). The curves were compared with the spectral reflectance curves of broadleaf plant leaves, and the similarity between the two spectral curves was calculated using the similarity formula (3-1).

[0061] Equation (3-1);

[0062] In the formula, x ik and x jkThese represent the spectral values ​​of the k-th band of the two spectral curves; m represents the total number of bands. and ρ represents the mean of spectral curves i and j. ij ρ represents the similarity between two spectral curves; the higher the similarity between the two spectral lines, the higher the similarity. ij The closer the value of ρ is to 1, the better if the two spectral lines are exactly the same. ij It equals 1.

[0063] 2. Visible light 60° gloss

[0064] According to GB / T 9754-2007 "Determination of 20°, 60° and 85° specular gloss of paint films without metallic pigments", the visible light 60° gloss of the hyperspectral camouflage coating fabric imitating broad-leaved plant leaves was tested by a gloss meter.

[0065] 3. Low temperature resistance

[0066] The low-temperature environmental adaptability of the hyperspectral camouflage coating fabric imitating broad-leaved plant leaves was measured in accordance with the provisions of GJB 150.4A-2009 "Laboratory Environmental Testing Methods for Military Equipment - Part 4: Low Temperature Testing".

[0067] 4. High temperature resistance

[0068] The high-temperature environmental adaptability of the hyperspectral camouflage coating fabric imitating broad-leaved plant leaves was measured in accordance with the provisions of GJB 150.3A-2009 "Laboratory Environmental Testing Methods for Military Equipment - Part 3: High Temperature Test".

[0069] 5. Resistance to damp heat

[0070] The damp heat resistance of the hyperspectral camouflage coating fabric imitating broadleaf plant leaves was measured under laboratory conditions in accordance with GB / T 1740-2007 "Determination of Damp Heat Resistance of Coating Film".

[0071] 6. Application amount of low emissivity material on the surface of hyperspectral-thermal infrared compatible camouflage fabric

[0072] A low-emissivity layer was sprayed onto the surface of a hyperspectral camouflage fabric using a spray gun. The amount of low-emissivity material applied to the fabric surface was calculated by measuring the weight of the fabric before and after spraying. The calculation formula is as follows:

[0073] Application amount (g / m 2 ) = (m1-m0) / S;

[0074] Where m1 is the mass (g) of the low-emissivity material after baking, m0 is the mass (g) of the hyperspectral camouflage fabric before spraying, and S is the area of ​​spraying (m²). 2 );

[0075] 7. Absolute value of radiant temperature difference

[0076] Thermal infrared images of the sample were captured using a thermal imager (model TiS20+ MAX), and the average radiation temperatures of the sample and the background environment were recorded. The absolute value of the radiation temperature difference between the two was calculated.

[0077] Example 1

[0078] Preparation and application of a hyperspectral camouflage coating fabric mimicking broadleaf plant leaves; the preparation method includes the following steps:

[0079] S101. Preparation of high-reflectivity coated fabric: Weigh 24g of adhesive and 61.2g of water, and add 1.8g of silicon dioxide, 15g of barium sulfate and 22g of titanium dioxide in sequence. Stir until uniform and free of particles to obtain a high-reflectivity coating. Use a coating machine to scrape the high-reflectivity coating onto the fabric surface and bake at 130℃ for 2~3 minutes to obtain a high-reflectivity coated fabric.

[0080] S102. Preparation of hyperspectral camouflage coating fabric: Weigh 40g of dry MIL-101(Cr) into a 5wt% lithium chloride solution, stir for 1h at room temperature, centrifuge to remove the lower precipitate, and dry at 140 ℃ for 12h to obtain Li-MIL-101(Cr).

[0081] Among them, MIL-101(Cr) has a specific surface area of ​​2600 m² at 25℃ and 65%RH. 2 / g, pore volume 0.24cm 3 / g, with a static water vapor adsorption capacity of 0.98g / g. 2g Li-MIL-101(Cr), 3g chrome green, 0.04g iron yellow, 0.15g iron red, 0.05g phthalocyanine blue, 5g binder DM-5128, 2g crosslinking agent CX-100, 10.5g thickener, and 77.26g water were stirred until homogeneous to obtain a hyperspectral camouflage coating. The hyperspectral camouflage coating was applied to the surface of polyester fabric using a coating method, and the fabric was fixed at 60℃ for 30 minutes to obtain a hyperspectral camouflage coating fabric resembling broadleaf plant leaves.

[0082] S103. Preparation of Hyperspectral-Thermal Infrared Compatible Camouflage Coating Fabric: 0.5 g of crosslinking agent GC-902 was added to 99.5 g of a 5% (w / w) dispersion of silver nanowires (average diameter 500 nm, average wire diameter 12 μm). The mixture was then sprayed onto the surface of the hyperspectral camouflage coating fabric. After color fixing at 30℃ for 6 h, the application amount of low emissivity material was controlled at 1.0 g / m². 2 This resulted in a hyperspectral-thermal infrared compatible camouflage coating fabric. The material's reflectance spectrum curve (1 nm spacing) is shown below. Figure 2As shown in Table 1, the spectral simulation results for typical background environments are presented in Table 2, and the infrared radiation characteristics are also shown in Table 3. The absolute value of the maximum radiative temperature difference between the sample and the background over a daily period after 30 days of outdoor placement is shown in Table 3, and the various physical properties of the sample are shown in Table 4.

[0083] Example 2

[0084] Preparation and application of a hyperspectral camouflage coating fabric mimicking broadleaf plant leaves; the preparation method includes the following steps:

[0085] S201, Preparation of hyperspectral camouflage coating fabric: Weigh 40g of dry MIL-101(Cr) into a 5wt% lithium chloride solution, stir for 1h at room temperature, centrifuge to remove the lower precipitate, and dry at 140℃ for 12h to obtain Li-MIL-101(Cr).

[0086] Among them, MIL-101(Cr) has a specific surface area of ​​2600 m² under conditions of 25℃ and 65%RH. 2 / g, pore volume 0.24cm 3 / g, with a static water vapor adsorption capacity of 0.98 g / g. 2g Li-MIL-101(Cr), 3g chrome green, 0.04g iron yellow, 0.15g iron red, 0.05g phthalocyanine blue, 5g binder DM-5128, 2g crosslinking agent CX-100, 10.5g thickener, and 77.26g water were stirred until homogeneous to obtain a hyperspectral camouflage coating. The hyperspectral camouflage coating was applied to the surface of a polyester fabric using a coating method, and the fabric was fixed at 60℃ for 30 minutes to obtain a hyperspectral camouflage coating fabric resembling broadleaf plant leaves.

[0087] Preparation of S202, Hyperspectral-Thermal Infrared Compatible Camouflage Coating Fabric: 0.5g of crosslinking agent GC-902 was added to a 5% (w / w) dispersion of silver nanowires (average diameter 500nm, average wire diameter 12μm). The mixture was then sprayed onto the surface of the hyperspectral camouflage coating fabric. After color fixing at 30℃ for 6 hours, the application amount of low emissivity material was controlled at 2.0g / m². 2 This resulted in a hyperspectral-thermal infrared compatible camouflage coating fabric. The material's reflectance spectrum curve (1 nm spacing) is shown below. Figure 3 As shown in Table 1, the spectral simulation results for typical background environments are presented in Table 2, and the infrared radiation characteristics are also shown in Table 3. The absolute value of the maximum radiative temperature difference between the sample and the background over a daily period after 30 days of outdoor placement is shown in Table 3, and the various physical properties of the sample are shown in Table 4.

[0088] Example 3

[0089] Preparation and application of a hyperspectral camouflage coating fabric mimicking broadleaf plant leaves; the preparation method includes the following steps:

[0090] S301. Preparation of high-reflectivity coated fabric: Weigh 24g of adhesive and 61.2g of water, and add 2g of silicon dioxide, 15g of barium sulfate and 25g of titanium dioxide in sequence. Stir until uniform and free of particles to obtain a high-reflectivity coating. Use a coating machine to scrape the high-reflectivity coating onto the fabric surface and bake at 130℃ for 2~3 minutes to obtain a high-reflectivity coated fabric.

[0091] S302. Preparation of hyperspectral camouflage coating fabric: Weigh 40g of dry MIL-101(Cr) into a 5 wt% lithium chloride solution, stir for 1h at room temperature, centrifuge to remove the lower precipitate, and dry at 140℃ for 12h to obtain Li-MIL-101(Cr).

[0092] Among them, MIL-101(Cr) has a specific surface area of ​​2600 m² under conditions of 25℃ and 65%RH. 2 / g, pore volume 0.24cm 3 / g, with a static water vapor adsorption capacity of 0.98g / g. 2g Li-MIL-101(Cr), 3g chrome green, 0.04g iron yellow, 0.15g iron red, 0.05g phthalocyanine blue, 5g binder DM-5128, 2g crosslinking agent CX-100, 10.5g thickener, and 77.26g water were stirred until homogeneous to obtain a hyperspectral camouflage coating. The hyperspectral camouflage coating was applied to the surface of polyester fabric using a coating method, and the fabric was fixed at 60℃ for 30 minutes to obtain a hyperspectral camouflage coating fabric resembling broadleaf plant leaves.

[0093] Preparation of S303, Hyperspectral-Thermal Infrared Compatible Camouflage Coating Fabric: 0.5g of crosslinking agent GC-902 was added to a 5% (w / w) dispersion of silver nanowires (average diameter 500nm, average wire diameter 12μm). The mixture was then sprayed onto the surface of the hyperspectral camouflage coating fabric. After color fixing at 30℃ for 6 hours, the application amount of low emissivity material was controlled at 2.0g / m². 2 This resulted in a hyperspectral-thermal infrared compatible camouflage coating fabric. The material's reflectance spectrum curve (1 nm spacing) is shown below. Figure 4 As shown in Table 1, the spectral simulation results for typical background environments are presented in Table 2, and the infrared radiation characteristics are also shown in Table 3. The absolute value of the maximum radiative temperature difference between the sample and the background over a daily period after 30 days of outdoor placement is shown in Table 3, and the various physical properties of the sample are shown in Table 4.

[0094] Conclusions of Examples 1-3: The spectral fit of the samples in Examples 1-3 with typical broad-leaved plant leaves was good, with a fit of ≥0.95, reaching a maximum of 0.981 (Table 1), meeting the first-level standard in GJB 1411A-2015 "Camouflage Requirements for Surface-to-Surface Missile Weapon Equipment Systems"; and after being placed in the field for 30 days, the maximum radiation temperature difference between the samples and the background broad-leaved plant leaves within one diurnal cycle was less than 5K; the damp heat resistance reached level 1; after the low temperature (-20℃) test, the sample coating did not become brittle or peel off, and after the high temperature (50℃) test, the sample coating did not become sticky or peel off; the visible light 60° gloss was ≤5; and the mildew resistance reached level 1.

[0095] Comparative Example 1

[0096] A method for preparing a green coated fabric includes the following steps:

[0097] S401, Preparation of green coated fabric: Weigh 40g of dry MIL-101(Cr) into a 5wt% lithium chloride solution, stir for 1h at room temperature, centrifuge to remove the lower precipitate, and dry at 140℃ for 12h to obtain Li-MIL-101(Cr).

[0098] Among them, MIL-101(Cr) has a specific surface area of ​​2600 m² under conditions of 25℃ and 65%RH. 2 / g, pore volume 0.24cm 3 / g, with a static water vapor adsorption capacity of 0.98g / g. 2g Li-MIL-101(Cr), 3g chrome green, 0.04g iron yellow, 0.15g iron red, 0.05g phthalocyanine blue, 5g binder DM-5128, 2g crosslinking agent CX-100, 10.5g thickener, and 77.26g water were stirred until homogeneous to obtain a hyperspectral camouflage coating. The hyperspectral camouflage coating was applied to the surface of polyester fabric using a coating method, and the color was fixed at 60℃ for 30 minutes to obtain a green coated fabric.

[0099] S402, Preparation of Composite Coated Fabric: 0.5g of crosslinking agent GC-902 was added to a dispersion of 99.5g of silver nanowires (average diameter 500nm, average wire diameter 12μm) with a mass fraction of 5%. The mixture was then sprayed onto the surface of a hyperspectral camouflage fabric. After color fixing at 30℃ for 6 hours, the application amount of low emissivity material was controlled at 1.0g / m². 2 This yields a composite coated fabric. The material's reflectance spectrum curve (1 nm spacing) is shown below. Figure 5 As shown in Table 1, the spectral simulation results for typical background environments are presented in Table 2, and the infrared radiation characteristics are also shown in Table 3. The absolute value of the maximum radiative temperature difference between the sample and the background over a daily period after 30 days of outdoor placement is shown in Table 3, and the various physical properties of the sample are shown in Table 4.

[0100] Conclusion of Comparative Example 1: Although Comparative Example 1 has good thermal infrared performance like Examples 1-3, the spectral fitting degree of Comparative Example 1 is worse than that of Examples 1-3. This is because although silver nanowires have good transparency in the visible light band, they have certain absorption in the near-infrared band, which makes the reflectivity of the hyperspectral camouflage material coated with silver nanowires decrease in the 780-2500nm band, thus reducing the fitting degree to a certain extent.

[0101] Comparative Example 2

[0102] A method for preparing a green coated fabric includes the following steps:

[0103] S501. Preparation of high-reflectivity coated fabric: Weigh 24g of adhesive and 61.2g of water, and add 1.8g of silicon dioxide, 15g of barium sulfate and 22g of titanium dioxide in sequence. Stir until uniform and free of particles to obtain a high-reflectivity coating. Use a coating machine to apply the high-reflectivity coating to the surface of the fabric, and bake at 130℃ for 2~3 minutes to obtain a high-reflectivity coated fabric.

[0104] S502. Preparation of green coated fabric: Weigh 40g of dry MIL-101(Cr) into a 5wt% lithium chloride solution, stir for 1h at room temperature, centrifuge to remove the lower precipitate, and dry at 140℃ for 12h to obtain Li-MIL-101(Cr).

[0105] Among them, MIL-101(Cr) has a specific surface area of ​​2600 m² under conditions of 25℃ and 65%RH. 2 / g, pore volume 0.24cm 3 / g, static water vapor adsorption capacity is 0.98g / g. 2g Li-MIL-101(Cr), 3g chrome green, 0.04g iron yellow, 0.15g iron red, 0.05g phthalocyanine blue, 5g binder DM-5128, 2g crosslinking agent CX-100, 10.5g thickener, and 77.26g water were stirred until homogeneous to obtain a hyperspectral camouflage coating. The hyperspectral camouflage coating was applied to the surface of polyester fabric using a coating method, and the color was fixed at 60℃ for 30 min to obtain a green coated fabric. The material reflectance spectrum curve (interval 1nm) is shown below. Figure 6 As shown in Table 1, the spectral simulation results for typical background environments are presented in Table 2, and the infrared radiation characteristics are also shown in Table 3. The absolute value of the maximum radiative temperature difference between the sample and the background over a daily period after 30 days of outdoor placement is shown in Table 3, and the various physical properties of the sample are shown in Table 4.

[0106] Conclusion of Comparative Example 2: Compared with Example 1, Comparative Example 2, due to its coating with a high-reflectivity inorganic coating of silica, barium sulfate, and titanium dioxide, exhibits excessively high reflectivity in the near-infrared band of 780–2500 nm, resulting in a certain degree of reduced goodness of fit. Furthermore, since Comparative Example 2 relies on the moisture absorption peaks at 1.45 μm and 1.93 μm to impart its thermal infrared performance, its thermal infrared performance is inferior to that of the sample coated with a low-emissivity material. Moreover, under continuous 30-day outdoor exposure, the water absorption peak weakens, indicating poor thermal infrared performance.

[0107] Comparative Example 3

[0108] A method for preparing a green coated fabric includes the following steps:

[0109] 40 g of dried MIL-101(Cr) was weighed into a 5 wt% lithium chloride solution, stirred at room temperature for 1 h, centrifuged, and the lower precipitate was collected and dried at 140 °C for 12 h to obtain Li-MIL-101(Cr). The specific surface area of ​​MIL-101(Cr) at 25 °C and 65% RH was 2600 m². 2 / g, pore volume 0.24 cm³ 3 / g, static water vapor adsorption capacity is 0.98g / g. 2g Li-MIL-101(Cr), 3g chrome green, 0.04g iron yellow, 0.15g iron red, 0.05g phthalocyanine blue, 5g binder DM-5128, 2g crosslinking agent CX-100, 10.5g thickener, and 77.26g water were stirred until homogeneous to obtain a hyperspectral camouflage coating. The hyperspectral camouflage coating was applied to the surface of polyester fabric using a coating method, and the color was fixed at 60℃ for 30 min to obtain a green coated fabric. The material reflectance spectrum curve (1nm spacing) is shown below. Figure 7 As shown in Table 1, the spectral simulation results for typical background environments are presented in Table 2, and the infrared radiation characteristics are also shown in Table 3. The absolute value of the maximum radiative temperature difference between the sample and the background over a daily period after 30 days of outdoor placement is shown in Table 3, and the various physical properties of the sample are shown in Table 4.

[0110] Conclusion of Comparative Example 3: Comparative Example 3 is a hyperspectral camouflage material. Its bottom does not contain highly reflective materials, and its surface does not contain low-emissivity materials, thus exhibiting a high degree of spectral fit. However, this material relies on the moisture absorption peaks at 1.45 μm and 1.93 μm to impart its thermal infrared performance. Its thermal infrared performance is inferior to that of the sample coated with a low-emissivity material. Furthermore, under continuous 30 days of field exposure, the water absorption peak weakens, indicating poor thermal infrared performance.

[0111] Comparative Example 4

[0112] A method for preparing a thermal infrared coated fabric includes the following steps:

[0113] 0.5 g of crosslinking agent GC-902 was added to a dispersion of 99.5 g of silver nanowires (average diameter 500 nm, average wire diameter 12 μm) with a mass fraction of 5%. The mixture was then sprayed onto the surface of a hyperspectral camouflage fabric. After color fixing at 30 °C for 6 h, the application rate of the low emissivity material was controlled at 1.0 g / m². 2 A thermal infrared coated fabric was obtained. The material's reflectance spectrum curve (1 nm spacing) is shown below. Figure 8 As shown in Table 1, the spectral simulation results for typical background environments are presented in Table 2, and the infrared radiation characteristics are also shown in Table 3. The absolute value of the maximum radiative temperature difference between the sample and the background over a daily period after 30 days of outdoor placement is shown in Table 3, and the various physical properties of the sample are shown in Table 4.

[0114] Conclusion of Comparative Example 4: Due to the lack of a hyperspectral camouflage layer, Comparative Example 4 did not exhibit the green peaks, red edges, and moisture absorption valleys characteristic of broadleaf plant leaves, resulting in poor spectral fitting. However, because the fabric surface was coated with a low-emissivity material, it exhibited good thermal infrared performance.

[0115] This invention prepares a hyperspectral-thermal infrared compatible camouflage coating fabric that mimics broadleaf plant leaves, enabling compatible camouflage against plant backgrounds in the 400-2500 nm and 8-14 μm wavelength bands. Specifically, the hyperspectral camouflage performance achieves a spectral fit of over 0.95 with leaves of broadleaf plants such as loquat, camphor, goldenrain tree, and magnolia, meeting the Class I standard in GJB 1411A-2015 "Camouflage Requirements for Surface-to-Surface Missile Weapon Equipment Systems." The thermal infrared camouflage performance achieves a radiation temperature difference of less than 5 K between the sample and the plant background within one diurnal cycle. Furthermore, the material also meets the following requirements: Class 1 resistance to damp heat; no brittleness or peeling of the coating after low-temperature (-20℃) testing; no stickiness or peeling of the coating after high-temperature (50℃) testing; visible light 60° gloss ≤ 5; and Class 1 resistance to mold. This material can be applied in hyperspectral / hyperspectral simulation and infrared camouflage fields.

[0116] This invention achieves decoupled control of spectral and thermal properties through a multi-layered composite structure designed on the surface of a fabric, as shown in the figure: 1) a high-reflectivity layer: a near-infrared high-reflectivity compensation layer composed of silicon dioxide, barium sulfate, and titanium dioxide; 2) a hyperspectral camouflage layer: a hyperspectral camouflage layer mimicking the spectrum of plants; and 3) a low-emissivity layer: a visible-light transparent / thermal-infrared low-emissivity silver nanowire film. The three layers work synergistically along the optical path to counteract the near-infrared absorption of the silver nanowires, maintaining full-band camouflage effectiveness. This solution overcomes the compatibility challenge between silver nanowires and hyperspectral camouflage through a hierarchical separation design, achieving for the first time that the material accurately simulates the spectral characteristics of plants in the visible-near-infrared band while maintaining a stable low emissivity in the thermal-infrared band, providing core technological support for next-generation multispectral stealth equipment.

[0117] This invention provides the preparation and application of a hyperspectral-thermal infrared compatible camouflage coating fabric that mimics the shape of broadleaf plant leaves. The coating fabric is made of, for example, a material that mimics the shape of broadleaf plant leaves. Figure 1 The structure consists of a textile fabric layer, a high-reflectivity layer, a hyperspectral camouflage layer, and a low-emissivity layer. The textile fabric can be a chemical or natural fiber fabric or its blended fabric. The hyperspectral camouflage layer mainly includes M-MIL-101(Cr), inorganic pigments, and crosslinking agents. The thermal infrared layer mainly includes silver nanowires and crosslinking agents. The high-reflectivity layer mainly includes silica, barium sulfate, titanium dioxide, and polyurethane adhesive.

[0118] Table 1. Spectral similarity between the sample and broadleaf plant leaves in the 400–2500 nm band.

[0119] Broadleaf plant leaves Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 loquat 0.978 0.963 0.978 0.841 0.856 0.981 ＜0.5 Osmanthus fragrans 0.975 0.975 0.965 0.826 0.874 0.981 ＜0.5 Aoki 0.968 0.964 0.974 0.857 0.863 0.983 ＜0.5 Photinia 0.981 0.971 0.969 0.847 0.897 0.960 ＜0.5 Octagon gold plate 0.967 0.968 0.976 0.863 0.857 0.983 ＜0.5 Crape myrtle 0.958 0.965 0.972 0.816 0.861 0.977 ＜0.5 cedar 0.971 0.972 0.978 0.843 0.847 0.976 ＜0.5 Loblolly Pine 0.959 0.976 0.968 0.816 0.835 0.980 ＜0.5 camphor tree 0.974 0.970 0.956 0.809 0.863 0.978 ＜0.5 Magnolia 0.963 0.973 0.966 0.806 0.849 0.971 ＜0.5

[0120] Table 2. Maximum radiation temperature difference between a daily-cycle sample and the background when placed in the field.

[0121] sample Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Maximum radiation temperature difference (K) 3.5 3.2 4.2 4.3 5.6 5.8 3.8

[0122] Table 3. Absolute values ​​of the maximum radiative temperature difference between the daily periodic sample and the background after 30 days of outdoor placement.

[0123] sample Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Maximum radiation temperature difference (K) 3.5 3.3 4.2 4.1 9.2 9.6 3.9

[0124] Table 4. Physical properties of the samples

[0125] parameter Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 <![CDATA[Visible light 60 o Gloss]]> 4.1 4.2 3.8 4.5 3.8 3.9 4.6 Moist heat resistance Level 1 Level 1 Level 1 Level 1 Level 1 Level 1 Level 1 High temperature resistance (50℃) No stickiness or peeling No stickiness or peeling No stickiness or peeling No stickiness or peeling No stickiness or peeling No stickiness or peeling No stickiness or peeling Low temperature resistance (-20℃) No brittleness or shedding No brittleness or shedding No brittleness or shedding No brittleness or shedding No brittleness or shedding No brittleness or shedding No brittleness or shedding

[0126] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method of making a broad-leaf plant leaf blade camouflage coating fabric, characterized by, Comprising the following steps: S1, preparation of high reflection coating fabric: weigh a certain amount of adhesive and water, and then add a certain amount of silica, barium sulfate and titanium white powder, stir until uniform and no particles, get high reflection coating; using coating machine, high reflection coating is scraped to the upper surface of the fabric, and baked at 130℃ for 2~3min, get high reflection coating fabric; S2, preparation of hyperspectral camouflage coating fabric: weigh a certain amount of dry MIL-101(Cr) in a certain concentration of inorganic salt solution, stir at room temperature for 1h, centrifuge and take the precipitate, dry at 140℃ for 12h, get composite hygroscopic material M-MIL-101(Cr); a certain amount of M-MIL-101(Cr), inorganic pigment, adhesive, crosslinking agent, thickening agent and water are stirred until uniform, get hyperspectral camouflage coating; using coating method, hyperspectral camouflage coating is scraped on the upper surface of high reflection coating fabric, and fixed at a certain temperature to get hyperspectral camouflage coating fabric imitating broadleaf plant leaves; S3, preparation of hyperspectral-thermal infrared compatible camouflage coating fabric: prepare a certain mass fraction of silver nanowire dispersion and crosslinking agent mixed solution, spray on the upper surface of hyperspectral camouflage coating fabric imitating broadleaf plant leaves, and fix at a certain temperature to get hyperspectral-thermal infrared compatible camouflage coating fabric.

2. The method of making a broadleaf plant leaf mimic camouflage coating fabric according to claim 1, wherein, In step S1, The mass ratio of silica, barium sulfate and titanium white powder is (0.5~5):(10~20):(15~30); The total amount of silica, barium sulfate and titanium white powder accounts for 15~50wt% of the total mass of high reflection coating.

3. The method of making a broadleaf plant leaf mimic camouflage coating fabric according to claim 1, wherein, In step S1, the adhesive accounts for 20~40wt% of the total mass of high reflection coating.

4. The method of making a broadleaf plant leaf mimic camouflage coating fabric of claim 1, wherein, In step S2, The porous hygroscopic material MIL-101 (Cr) has a specific surface area ≥ 2500 m 2 / g, a pore volume ≥ 0.20 cm 3 / g, a static water vapor adsorption capacity ≥ 0.90 g / g at 25 °C and 65 % RH; The inorganic salt is one or more of lithium chloride, calcium chloride, potassium chloride or magnesium sulfate, and the inorganic salt concentration is 1~15wt%; The mass ratio of MIL-101(Cr) to inorganic salt is 1:(5~25); M-MIL-101(Cr) accounts for 0.1~5wt% of the total mass of hyperspectral camouflage coating.

5. The method of making a broadleaf plant leaf mimic camouflage coating fabric of claim 1, wherein, In step S2, The crosslinking agent is one of GC-902, CX-100, ZS-1890, HD-3100A, TE3893, LOCTITE UK2015 and Sac-100, accounting for 1~10wt% of the total mass of hyperspectral camouflage coating; The inorganic pigment includes chromium green, iron yellow, iron red and phthalocyanine blue, and the mass ratio is (30~35):(0.3~0.5):(1.0~2.0):(0.4~0.6); The fixing temperature is 30~100℃, and the time is 1min~4h.

6. The method of making a broadleaf plant leaf mimic camouflage coating fabric of claim 1, wherein, In step S3, The average diameter of silver nanowire dispersion is 5nm~500nm, the average wire diameter is 5~15μm, and the mass fraction of silver nanowire dispersion is 3~10wt%.

7. The method of making a broadleaf plant leaf mimic camouflage coating fabric according to claim 1, wherein, In step S3, The crosslinking agent is one of GC-902, CX-100, ZS-1890, HD-3100A, TE3893, LOCTITE UK2015 and Sac-100, accounting for 0.1~0.5wt% of the total mass of the mixed solution; The fixing temperature is 30-50 DEG C, and the time is 15 min-4 h; The amount of silver nanowires in the hyperspectral-thermal infrared compatible camouflage coating fabric is 1.0-5.0 g / m 2 .

8. The method of making a broadleaf plant leaf mimic camouflage coating fabric of claim 1, wherein, The fabric used in step S1 is any one of chemical fibers and natural fibers and blended fabrics thereof.

9. The application of the leaflet-like super-spectral and thermal-infrared compatible camouflage coating fabric imitating broad-leaf plant leaves prepared by the preparation method in any one of claims 1-8 in the field of high / super-spectral simulation and infrared camouflage.

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