Green biomimetic camouflage material simulating optical and infrared performance of vegetation and preparation method thereof

Abstract

The application discloses a green bionic camouflage material simulating optical and infrared performance of vegetation and a preparation method of the green bionic camouflage material. The green bionic camouflage material is made by double-sidedly dipping and coating green camouflage paint on a microporous film. The green camouflage paint is made of the following raw materials in percentage by weight: titanium white 5-6%, near-infrared high-reflection black 9-10%, organic yellow 17-18.2%, water-absorbing resin 1.2-1.5%, composite adsorbent 1-1.2%, film-forming material 35-40% and solvent 20-35%. The composite adsorbent is made of porous white carbon black and inorganic hydrated salt. The green bionic camouflage material can simulate the spectrum of green vegetation in 380nm-2500nm and the water absorption peaks near 1450nm and 1930nm. The water-absorbing resin can lock water to simulate the inherent water of vegetation leaves; the composite adsorbent is driven by environmental temperature and humidity and solar radiation, and can realize water vapor adsorption / desorption through the microporous film to simulate the transpiration of green vegetation leaves. The diurnal radiation temperature difference between the green bionic camouflage material and vegetation leaves is within ±2℃, and the green bionic camouflage material can well simulate the infrared radiation characteristics of green vegetation.

Description

Technical fields:

[0001] This invention belongs to the field of camouflage materials technology, and specifically relates to green biomimetic camouflage materials that simulate the optical and infrared properties of vegetation and their preparation methods. Background technology:

[0002] The essence of camouflage is to simulate the characteristics of the natural background, eliminate the differences in features between the military target and its surroundings, and thus make the target blend into the natural environment. Green vegetation, as a primary natural background, is the main object of camouflage simulation.

[0003] Green camouflage material is a key material for camouflage operations, requiring it to have a spectral reflectance curve similar to that of green vegetation across the entire optical and near-infrared band (380nm–2500nm). According to national military standards, the specific spectral values ​​are: 40–60% at 1200nm, 30–50% at 1400nm, 20–40% at 1800nm, and 0–20% at 2500nm. It must also simulate the water absorption peaks of green vegetation near 1450nm and 1930nm. In the infrared band (8μm–14μm), the green camouflage material must have infrared radiation characteristics as similar as possible to those of green vegetation. Green vegetation has a natural ability to regulate its own temperature. During the day, when exposed to solar radiation, it regulates its temperature through transpiration from its leaves to prevent excessive temperature increases. At night, the water content in the leaves prevents excessive temperature drops, giving green vegetation a unique trend in infrared radiation characteristics. Conventional green infrared camouflage materials struggle to simulate the infrared radiation characteristics of green plants in real time.

[0004] The information disclosed in this background section is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention:

[0005] The purpose of this invention is to provide a green biomimetic camouflage material that simulates the optical and infrared properties of vegetation and its preparation method, thereby overcoming the defects in the prior art.

[0006] To achieve the above objectives, the present invention provides a green biomimetic camouflage material that simulates the optical and infrared properties of vegetation, comprising the following raw materials in weight percentages: 5%–6% titanium dioxide, 9%–10% near-infrared high reflectance black, 17%–18.2% organic yellow, 1.2%–1.5% superabsorbent polymer powder, 1%–1.2% composite adsorbent, 35%–40% film-forming substance, and 20%–35% solvent.

[0007] Furthermore, as a preferred option, the titanium dioxide is rutile titanium dioxide.

[0008] Furthermore, as a preferred option, the near-infrared high reflectance black is selected from vat black pigment.

[0009] Furthermore, as a preferred option, the organic yellow is selected from macromolecular yellow or azo yellow.

[0010] Furthermore, as a preferred option, the superabsorbent polymer powder is selected from polymethyl methacrylate resin powder, starch-grafted acrylic resin powder, grafted acrylamide resin powder, cross-linked carboxymethyl cellulose powder, cross-linked carboxymethyl cellulose-grafted acrylamide resin powder, or cross-linked hydroxyethyl cellulose-grafted acrylamide polymer resin powder.

[0011] Furthermore, preferably, the composite adsorbent is composed of porous silica and inorganic hydrated salt; the preparation method of the composite adsorbent is as follows:

[0012] Step 1: Mix porous silica and inorganic hydrated salt at a weight ratio of 1:2;

[0013] Step 2: Add deionized water to the above mixture, wherein the mass ratio of the mixture to deionized water is 1:1. After stirring evenly, let it stand at a constant temperature of 55℃~65℃ for 20h~30h.

[0014] Step 3: Place the above-mentioned well-mixed solution in an oven to dry, and obtain the composite adsorbent.

[0015] Furthermore, as a preferred embodiment, the inorganic hydrated salt is selected from KF·4H2O, LiNO3·3H2O and Na2S2O3·5H2O, with a weight ratio of 1:2 to 2.5:1.

[0016] Furthermore, preferably, the film-forming material is selected from breathable polyurethane or breathable acrylic resin.

[0017] This invention also provides a method for preparing a green biomimetic camouflage material that simulates the optical and infrared properties of vegetation, comprising the following steps:

[0018] Step 1: Prepare the raw materials according to the above-mentioned proportions of green biomimetic camouflage material, reserve a portion of the film-forming material, mix the other raw materials and grind them in a grinder for 50-70 minutes;

[0019] Step 2: Add the ground material to the remaining reserved film-forming material and stir in a high-speed disperser for about 10 to 20 minutes to obtain a mixture.

[0020] Step 3: Immerse the polyvinylidene fluoride microporous membrane in the above mixture and let it stand for 10-15 hours;

[0021] Step 4: After taking out the polyvinylidene fluoride microporous film, place it on a tray to air dry for 50-70 minutes, then place it in an oven at 75℃-85℃ to bake for 50-70 minutes, and then take it out and let it cool naturally.

[0022] Furthermore, preferably, the thickness of the polyvinylidene fluoride microporous film is 200 μm ± 10 μm.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] (1) This invention uses specific pigments for spectral matching, which can simulate the spectral characteristics of green vegetation from 380nm to 2500nm and the water absorption peaks near 1450nm and 1930nm; it uses superabsorbent polymer powder to lock in water, which can simulate the inherent water inside the leaves of vegetation; and the composite adsorbent, driven by environmental temperature, humidity and solar radiation, can autonomously achieve the adsorption / desorption of water vapor molecules through polyvinylidene fluoride microporous film, thereby simulating the transpiration of green vegetation leaves, realizing the simulation of the infrared radiation characteristic trend of green vegetation, and the test results show that the diurnal radiation temperature difference between the green biomimetic camouflage material and the vegetation leaves is within ±2℃; a green biomimetic camouflage material with good camouflage effect is obtained, which has a wide range of applications in the military field.

[0025] (2) The composite adsorbent of the present invention is composed of porous silica and inorganic hydrated salt, which avoids the precipitation of hydrated salt and ensures the performance stability of the coating system. Attached image description:

[0026] Figure 1 This is a scanning electron microscope image of the surface of the polyvinylidene fluoride microporous film of the present invention;

[0027] Figure 2 This is a spectrum of Embodiment 1 of the present invention;

[0028] Figure 3 Infrared test scene images of the green camouflage materials prepared in Examples 1 and 2 of this invention;

[0029] Figure 4 The graph shows the infrared radiation performance test results for one day and night in Embodiment 1 of the present invention.

[0030] Figure 5 This is a graph showing the infrared radiation performance test results for one day and night in Embodiment 2 of the present invention. Detailed implementation method:

[0031] The specific embodiments of the present invention will be described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.

[0032] The following provides a brief overview of one or more aspects to offer a basic understanding of them. This overview is not an exhaustive summary of all conceived aspects, nor is it intended to identify key or decisive elements of all aspects, nor to define the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form to prepare for the more detailed descriptions that follow.

[0033] Example 1:

[0034] The green biomimetic camouflage material, which simulates the optical and infrared properties of vegetation, is composed of the following raw materials by weight percentage: 5% rutile titanium dioxide, 9% reduced black pigment, 17% macromolecular yellow, 1.2% polymethyl methacrylate resin powder, 1% composite adsorbent, 38% breathable polyurethane, and 28.8% solvent, wherein the solvent is a mixture of toluene and xylene in a 1:1 ratio.

[0035] The preparation method of the composite adsorbent is as follows:

[0036] Step 1: Mix porous silica with inorganic hydrated salts at a weight ratio of 1:2. The inorganic hydrated salts selected are KF·4H2O, LiNO3·3H2O, and Na2S2O3·5H2O, which are mixed in a mass ratio of 1:2:1.

[0037] Step 2: Add deionized water to the above mixture, wherein the mass ratio of the mixture to deionized water is 1:1, stir evenly, and let stand at a constant temperature of 60°C for 24 hours.

[0038] Step 3: Place the above-mentioned uniformly mixed solution in an oven and set the oven temperature to 100℃. Dry for 22 hours to remove free water and obtain the composite adsorbent.

[0039] The preparation method of the above-mentioned green camouflage coating includes the following steps:

[0040] Step 1: Prepare the raw materials according to the above proportions for green camouflage coating, reserve a portion of the film-forming material, mix the other raw materials and grind them in a grinder for about 1 hour;

[0041] Step 2: Add the ground material to the remaining reserved film-forming material, and stir in a high-speed disperser at 6000 rpm for about 15 minutes to obtain a mixture.

[0042] Step 3: Select a polyvinylidene fluoride microporous film with a thickness of about 200μm±10μm as the substrate material, immerse the polyvinylidene fluoride microporous film in the above mixture and let it stand for 12 hours.

[0043] Step 4: After taking out the above polyvinylidene fluoride microporous film, place it on a tray and air dry it under environmental conditions for about 1 hour, then place it in an 80℃ oven for 1 hour, and then take it out and let it cool naturally to obtain green biomimetic camouflage material.

[0044] Example 2:

[0045] The green biomimetic camouflage material, which simulates the optical and infrared properties of vegetation, is composed of the following raw materials by weight percentage: 5.5% rutile titanium dioxide, 9.5% reduced black pigment, 17.5% macromolecular yellow, 1.3% polymethyl methacrylate resin powder, 1.1% composite adsorbent, 38% breathable polyurethane, and 27.1% solvent, wherein the solvent is a mixture of toluene and xylene in a 1:1 ratio;

[0046] The preparation method of the composite adsorbent is as follows:

[0047] Step 1: Mix porous silica with inorganic hydrated salts at a weight ratio of 1:2. The inorganic hydrated salts selected are KF·4H2O, LiNO3·3H2O, and Na2S2O3·5H2O, which are mixed in a mass ratio of 1:2:1.

[0048] Step 2: Add deionized water to the above mixture, wherein the mass ratio of the mixture to deionized water is 1:1, stir evenly, and let stand at a constant temperature of 60°C for 24 hours.

[0049] Step 3: Place the above-mentioned uniformly mixed solution in an oven and set the oven temperature to 100℃. Dry for 22 hours to remove free water and obtain the composite adsorbent.

[0050] The preparation method of the above-mentioned green camouflage coating includes the following steps:

[0051] Step 1: Prepare the raw materials according to the above proportions for green camouflage coating, reserve a portion of the film-forming material, mix the other raw materials and grind them in a grinder for about 1 hour;

[0052] Step 2: Add the ground material to the remaining reserved film-forming material, and stir in a high-speed disperser at 6000 rpm for about 15 minutes to obtain a mixture.

[0053] Step 3: Select a polyvinylidene fluoride microporous film with a thickness of about 200μm±10μm as the substrate material, immerse the polyvinylidene fluoride microporous film in the above mixture and let it stand for 12 hours.

[0054] Step 4: After taking out the above polyvinylidene fluoride microporous film, place it on a tray and air dry it under environmental conditions for about 1 hour, then place it in an 80℃ oven for 1 hour, and then take it out and let it cool naturally to obtain green biomimetic camouflage material.

[0055] Example 3:

[0056] The green biomimetic camouflage material, which simulates the optical and infrared properties of vegetation, is composed of the following raw materials by weight percentage: 6% rutile titanium dioxide, 10% reduced black pigment, 18.2% macromolecular yellow, 1.5% polymethyl methacrylate resin powder, 1.2% composite adsorbent, 40% breathable polyurethane, and 23.1% solvent, wherein the solvent is a mixture of toluene and xylene in a 1:1 ratio;

[0057] The preparation method of the composite adsorbent is as follows:

[0058] Step 1: Mix porous silica with inorganic hydrated salts at a weight ratio of 1:2. The inorganic hydrated salts selected are KF·4H2O, LiNO3·3H2O, and Na2S2O3·5H2O, which are mixed in a mass ratio of 1:2:1.

[0059] Step 2: Add deionized water to the above mixture, wherein the mass ratio of the mixture to deionized water is 1:1, stir evenly, and let stand at a constant temperature of 60°C for 24 hours.

[0060] Step 3: Place the above-mentioned uniformly mixed solution in an oven and set the oven temperature to 100℃. Dry for 22 hours to remove free water and obtain the composite adsorbent.

[0061] The preparation method of the above-mentioned green camouflage coating includes the following steps:

[0062] Step 1: Prepare the raw materials according to the above proportions for green camouflage coating, reserve a portion of the film-forming material, mix the other raw materials and grind them in a grinder for about 1 hour;

[0063] Step 2: Add the ground material to the remaining reserved film-forming material, and stir in a high-speed disperser at 6000 rpm for about 15 minutes to obtain a mixture.

[0064] Step 3: Select a polyvinylidene fluoride microporous film with a thickness of about 200μm±10μm as the substrate material, immerse the polyvinylidene fluoride microporous film in the above mixture and let it stand for 12 hours.

[0065] Step 4: After taking out the above polyvinylidene fluoride microporous film, place it on a tray and air dry it under environmental conditions for about 1 hour, then place it in an 80℃ oven for 1 hour, and then take it out and let it cool naturally to obtain green biomimetic camouflage material.

[0066] In Examples 1, 2, and 3 above, the polyvinylidene fluoride microporous membrane serves to simulate the stomatal microstructure of plant leaves, thereby regulating the adsorption / desorption of water molecules by the composite adsorbent. The microporous membrane surface has numerous uniformly distributed micropores with a porosity of 60%–80% and a pore size ranging from 0.7 μm to 0.9 μm, ensuring that water vapor can pass freely while liquid water cannot. Its scanning electron microscopy reveals… Figure 1 As shown.

[0067] The spectral reflectance characteristics of the green biomimetic camouflage materials prepared in Examples 1, 2, and 3 were tested. The results showed that the developed green biomimetic camouflage materials have spectral characteristics similar to green vegetation. The spectral values ​​in the 380nm to 2500nm band meet the spectral band requirements of the national military standard (see table below). The water characteristic absorption peaks are obvious near 1450nm and 1930nm.

[0068]

[0069] The spectrum of Example 1 is as follows: Figure 2 As shown.

[0070] The infrared radiation performance of the camouflage materials prepared in Examples 1 and 2 was tested. The specific testing method is as follows: In the thermal infrared band, an infrared thermal imager was used to conduct an infrared radiation performance test for one day and night, with a test time interval of 1 hour.

[0071] The green biomimetic camouflage material samples from Examples 1 and 2 were numbered and placed on green plants, designated Sample 1 and Sample 2. The sample surfaces were either parallel or perpendicular to the horizontal plane to simulate the morphology of different plant leaves, such as... Figure 3 As shown;

[0072] The surface radiation temperature of green biomimetic camouflage material samples and plant leaves was collected sequentially, and the results are as follows: Figure 4 , Figure 5 As shown.

[0073] from Figure 4 and Figure 5It can be seen that the radiant temperature of Sample 1 and Sample 2 is consistent with the trend of the control leaf throughout the day. Taking the average temperature of the three leaves as the representative of the actual leaf temperature, the maximum radiant temperature difference between Sample 1 and the actual leaf occurs at 0:00 the next day, at which time the radiant temperature of Sample 1 is 2.0℃ higher than that of the actual leaf; the maximum radiant temperature difference between Sample 2 and the actual leaf occurs at 6:20 the next morning, at which time the radiant temperature of Sample 2 is 1.7℃ lower than that of the actual leaf. Throughout the 24 hours, the temperature difference between the green biomimetic camouflage materials Sample 1 and Sample 2 and the vegetation leaves is within ±2℃, exhibiting a similar radiant temperature change trend to the vegetation; Example 3 has the same infrared effect, which will not be elaborated further.

[0074] In summary, the green biomimetic camouflage material designed and manufactured using this invention has a good camouflage effect.

[0075] The technical principle of this invention is as follows:

[0076] This study utilizes porous microstructured membrane materials to simulate the stomatal channels of transpiration in green plant leaves; it employs superabsorbent polymer powder to lock in moisture, simulating the inherent water within plant leaves; and a composite adsorbent, driven by environmental conditions such as temperature, humidity, and solar radiation, autonomously achieves water molecule adsorption / desorption. Specifically, at night when temperatures are low and humidity is relatively high, the composite adsorbent adsorbs water vapor from the air, releasing heat and preventing the temperature of the green biomimetic camouflage material from dropping too much. During the day when temperatures rise, the composite adsorbent desorbs crystal water, turning it into water vapor that carries away heat, preventing the temperature of the green biomimetic camouflage material from rising too much, thus simulating the infrared radiation characteristics of green vegetation. Furthermore, it uses pigments with specific spectra for spectral matching to achieve precise simulation of the spectral characteristics of green vegetation, thereby achieving a good biomimetic camouflage effect.

[0077] The foregoing description of specific exemplary embodiments of the invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. A green biomimetic camouflage material that simulates the optical and infrared properties of vegetation, characterized in that: It is composed of the following raw materials in weight percentage: 5.5%~6% rutile titanium dioxide, 9%~10% near-infrared high reflectance black, 17%~18.2% organic yellow, 1.2%~1.5% superabsorbent polymer powder, 1%~1.2% composite adsorbent, 35%~40% film-forming substance and 20%~35% solvent; the composite adsorbent is composed of porous silica and inorganic hydrated salt.

2. The green biomimetic camouflage material simulating the optical and infrared properties of vegetation according to claim 1, characterized in that: The near-infrared high reflectance black is made from a reduction black pigment.

3. The green biomimetic camouflage material simulating the optical and infrared properties of vegetation according to claim 1, characterized in that: The organic yellow is selected from macromolecular yellow or azo yellow.

4. The green biomimetic camouflage material simulating the optical and infrared properties of vegetation according to claim 1, characterized in that: The superabsorbent polymer powder is selected from polymethyl methacrylate resin powder, starch-grafted acrylic resin powder, grafted acrylamide resin powder, cross-linked carboxymethyl cellulose powder, cross-linked carboxymethyl cellulose-grafted acrylamide resin powder, or cross-linked hydroxyethyl cellulose-grafted acrylamide polymer resin powder.

5. The green biomimetic camouflage material simulating the optical and infrared properties of vegetation according to claim 1, characterized in that: The composite adsorbent is composed of porous silica and inorganic hydrated salt; the preparation method of the composite adsorbent is as follows: Step 1: Mix porous silica and inorganic hydrated salt at a weight ratio of 1:2; Step 2: Add deionized water to the above mixture, wherein the mass ratio of the mixture to deionized water is 1:1, stir evenly, and let it stand at a constant temperature of 55℃~65℃ for 20h~30h. Step 3: Place the above-mentioned well-mixed solution in an oven to dry, and obtain the composite adsorbent.

6. The green biomimetic camouflage material simulating the optical and infrared properties of vegetation according to claim 5, characterized in that: The inorganic hydrated salt is selected from KF·4H2O, LiNO3·3H2O, and Na2S2O3·5H2O, with a weight ratio of 1:2 to 2.5:

1. 。 7. The green biomimetic camouflage material simulating the optical and infrared properties of vegetation according to claim 1, characterized in that: The film-forming material is selected from either a breathable polyurethane resin or a breathable acrylic resin.

8. A method for preparing green biomimetic camouflage materials that simulate the optical and infrared properties of vegetation, characterized in that: Includes the following steps: Step 1: Prepare the raw materials according to the proportion of the green biomimetic camouflage material according to any one of claims 1 to 7, reserve a portion of the film-forming material, mix the other raw materials and grind them in a grinder for 50 to 70 minutes; Step 2: Add the ground material to the remaining reserved film-forming material and stir in a high-speed disperser for 10-20 minutes to obtain a mixture. Step 3: Immerse the polyvinylidene fluoride microporous membrane in the above mixture and let it stand for 10-15 hours; Step 4: After taking out the polyvinylidene fluoride microporous film, place it on a tray to air dry for 50-70 minutes, then place it in an oven at 75℃-85℃ for 50-70 minutes, and then take it out and let it cool naturally.

9. The method for preparing green biomimetic camouflage material simulating the optical and infrared properties of vegetation according to claim 8, characterized in that: The thickness of the polyvinylidene fluoride microporous film is 200 mm ± 10 mm.

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