Multiband infrared stealth composite material and preparation method thereof

Abstract

The invention relates to the technical field of military stealth materials, in particular to a multiband infrared stealth composite material and a preparation method thereof.The multiband infrared stealth composite material comprises an outer layer and an inner layer, each of the outer layer and the inner layer comprises a base material layer and a functional plating layer which are sequentially arranged from outside to inside, the base material layer is formed by blending aramid fibers and conductive fibers, and the functional plating layer is formed by blending the aramid fibers and the conductive fibers. The surface of the base material layer is provided with an infrared regulation and control printing layer, the infrared regulation and control printing layer is made of ITO / ATO composite oxide, the functional plating layer comprises a first aluminum plating layer and a first boron nitride layer which are sequentially arranged from outside to inside, and the first boron nitride layer on the outer layer and the first boron nitride layer on the inner layer are in composite connection through an adhesive layer. The first aluminum plating layer and the first boron nitride layer are combined in a sequential plating manner; the aramid fibers and the conductive fibers are blended, the mechanical property of the material is guaranteed, the base material layer is matched with the synergistic effect of the infrared regulation and control printing layer and the functional plating layer, the emissivity of the whole material is reduced, and effective regulation and control in a broadband are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of military stealth materials, and relates to a multi-band infrared stealth composite material and a preparation method thereof. Background Art

[0002] With the rapid development of infrared detection technology, the performance requirements for infrared stealth materials are becoming increasingly stringent. Existing infrared stealth materials have significant deficiencies in key performance aspects such as lightweight, wide-band regulation, and high mechanical strength. For example, many current infrared stealth materials on the market are difficult to control the areal density below 350 g / m 2 The following, which cannot meet the lightweight requirements of equipment, not only increases the load of the equipment but may also affect its mobility and endurance. In terms of band regulation, existing materials are difficult to achieve effective regulation in the 3-14 μm wide band, resulting in a significant reduction in the stealth effect when facing infrared detection devices in different bands. In terms of mechanical strength, the strength of most materials is less than 400 MPa, and in actual use, it is easily damaged by external forces, affecting the stability and durability of the stealth performance.

[0003] In addition, although traditional sandwich-structured infrared stealth materials can achieve the stealth function to a certain extent, the coating layer and the bonding interface are prone to delamination during long-term use, which affects the overall performance of the material. Therefore, it is of great practical significance to develop a multi-band infrared stealth composite material with lightweight, wide-band regulation, and high mechanical strength and its preparation method. Summary of the Invention

[0004] The present invention provides a multi-band infrared stealth composite material and a preparation method thereof to solve the problems of the prior art.

[0005] The object of the present invention can be achieved by the following technical solutions:

[0006] A multi-band infrared stealth composite material includes: an outer layer and an inner layer. Both the outer layer and the inner layer include a base material layer and a functional coating layer arranged in sequence from outside to inside. The base material layer is made of a blend of aramid fiber and conductive fiber. An infrared regulation printing layer is provided on the surface of the base material layer. The infrared regulation printing layer is made of ITO / ATO composite oxide. The functional coating layer includes a first aluminum plating layer and a first boron nitride layer arranged in sequence from outside to inside. The first boron nitride layer of the outer layer is compounded and connected with the first boron nitride layer of the inner layer through an adhesive layer. The first aluminum plating layer and the first boron nitride layer are combined in a sequential plating manner.

[0007] For further improvement, an intermediate layer is provided between the outer layer and the inner layer. The intermediate layer includes a PET substrate layer, a second aluminum plating layer, and a second boron nitride layer arranged in sequence from top to bottom. The second aluminum plating layer and the second boron nitride layer are combined by sequential plating.

[0008] For further improvement, the conductive fiber is silver-plated polyamide, copper-plated carbon fiber, or MXene-coated polyester material.

[0009] For further improvement, the proportion of aramid fiber in the substrate layer is 80 - 95%, the proportion of conductive fiber is 5 - 20%, and the areal density of the substrate layer is 120 - 180 g / m 2 .

[0010] For further improvement, the surface resistance of the infrared regulation printing layer < 100 Ω / Sq, and the regulation range of the emissivity of the camouflage pattern area is 0.3 - 0.7.

[0011] For further improvement, the thickness of the first aluminum plating layer in the functional coating is 30 - 80 nm, and the thickness of the first boron nitride layer in the functional coating is 0.5 - 2 μm.

[0012] For further improvement, the thickness of the second aluminum plating layer in the intermediate layer is 30 - 80 nm, and the thickness of the second boron nitride layer in the intermediate layer is 0.5 - 2 μm.

[0013] For further improvement, the main body of the adhesive layer is flame-retardant polyurethane glue. Boron nitride or graphene fillers are provided in the flame-retardant polyurethane glue, and the thermal conductivity of the flame-retardant polyurethane glue > 0.2 W / m·K.

[0014] A preparation method of a multi-band infrared stealth composite material includes the following steps:

[0015] S1: Preparation of the substrate layer: Blend 80 - 95% of aramid fiber with 5 - 20% of conductive fiber to make a substrate layer with an areal density of 120 - 180 g / m 2 ;

[0016] S2: Preparation of the infrared regulation printing layer: Use ITO / ATO composite oxide to make the infrared regulation printing layer, and form a camouflage pattern on the surface of the substrate layer obtained in step S1 through vacuum plating or rotary screen printing process;

[0017] S3: Preparation of the functional coating: On the surface of the substrate layer treated in step S2, through sequential plating, first deposit a first aluminum plating layer with a thickness of 30 - 80 nm, and then deposit a first boron nitride layer with a thickness of 0.5 - 2 μm to form a functional coating;

[0018] S4: Outer layer and inner layer fabrication: Use the materials that have completed step S3 as semi-finished products for the outer layer and the inner layer respectively, and set them aside.

[0019] S5: Two-layer lamination: Connect the first boron nitride layer of the outer layer and the first boron nitride layer of the inner layer through an adhesive layer to complete the preparation of the multi-band infrared stealth composite material.

[0020] Further improvement, S6: Intermediate layer preparation: After the fabrication of the outer layer and the inner layer in step S4, set an intermediate layer. On the PET substrate layer, deposit a second aluminum plating layer with a thickness of 30 - 80 nm and a second boron nitride layer with a thickness of 0.5 - 2 μm in a sequential plating manner to form the intermediate layer;

[0021] S7: Three-layer lamination: Connect the first boron nitride layer of the outer layer and the PET substrate layer of the intermediate layer through an adhesive layer, and connect the first boron nitride layer of the inner layer and the second boron nitride layer of the intermediate layer through an adhesive layer to complete the preparation of the multi-band infrared stealth composite material.

[0022] Compared with the prior art, the beneficial effects of the multi-band infrared stealth composite material and its preparation method of the present invention:

[0023] In the two-layer multi-band infrared stealth composite material, the outer layer and the inner layer achieve the synergistic optimization of infrared reflection and heat conduction through the facing connection of the plating layers. By blending aramid fibers and conductive fibers, it not only ensures the mechanical properties of the material but also endows it with certain conductivity, which helps to adjust the infrared emissivity. Cooperating with the infrared regulation printing layer made of ITO / ATO composite oxides, by controlling the surface resistance and utilizing its selective absorption and emission characteristics in the infrared band, the regulation of the emissivity is realized, and forming a camouflage pattern can further enhance the stealth effect; at the same time, the boron nitride layer and the aluminum layer in the functional plating layers of the outer layer and the inner layer achieve a double-layer combination, improving the infrared reflection performance and good thermal stability; in the three-layer multi-band infrared stealth composite material, the outer layer, the intermediate layer and the inner layer achieve the synergistic optimization of infrared reflection and heat conduction through the facing connection of the plating layers and the gradient plating in the interlayer. The setting of the intermediate layer further optimizes the reflection and absorption performance of the material in the infrared band; the cooperation of the substrate layer, the infrared regulation printing layer and the functional plating layer reduces the emissivity of the overall material and realizes the effective regulation in a wide band. Description of the Drawings

[0024] Figure 1 It is a schematic structural diagram of the two-layer lamination of the present invention

[0025] Figure 2 It is a schematic structural diagram of the three-layer lamination of the present invention

[0026] In the figure, 1 - outer layer, 2 - inner layer, 3 - substrate layer, 4 - functional coating layer, 41 - first aluminum plating layer, 42 - first boron nitride layer, 5 - infrared regulation printing layer, 6 - intermediate layer, 61 - PET substrate layer, 62 - second aluminum plating layer, 63 - second boron nitride layer, 7 - adhesive layer. Detailed implementation mode

[0027] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0028] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0029] The following combines the embodiments and the attached Figures 1-2 , and further elaborates on the technical solutions of the present invention.

[0030] Embodiment 1

[0031] A multi-band infrared stealth composite material includes: an outer layer 1 and an inner layer 2. Both the outer layer 1 and the inner layer 2 include a substrate layer 3 and a functional coating layer 4 arranged in sequence from outside to inside. The substrate layer 3 is made of a blend of aramid fiber and conductive fiber. An infrared regulation printing layer 5 is provided on the surface of the substrate layer 3. The infrared regulation printing layer 5 is made of ITO / ATO composite oxide. The functional coating layer 4 includes a first aluminum plating layer 41 and a first boron nitride layer 42 arranged in sequence from outside to inside. The first boron nitride layer 42 of the outer layer 1 is compounded and connected with the first boron nitride layer 42 of the inner layer 2 through an adhesive layer 7. The first aluminum plating layer 41 and the first boron nitride layer 42 are combined in a sequential plating manner.

[0032] A preparation method of a multi-band infrared stealth composite material includes the following steps:

[0033] S1: Substrate layer preparation: Blend 92% aramid fiber and 8% silver-plated polyamide conductive fiber to make a surface density of 150 g / m 2The substrate layer, wherein the aramid fiber is para-aramid with a single filament diameter of 12 - 15 μm; the single filament diameter of the conductive fiber is 10 - 12 μm, and it is woven in a 2 / 2 twill by a rapier loom with a warp density of 60 threads / cm and a weft density of 40 threads / cm to form a three-dimensional intertwined structure, enabling the conductive fiber to form a continuous conductive network in the substrate layer;

[0034] S2: Preparation of the infrared regulation printing layer: An infrared regulation printing layer is made of ITO / ATO composite oxide, and a camouflage pattern is formed on the surface of the substrate layer obtained in step S1 through vacuum plating or rotary screen printing process, controlling the surface resistance to be 80 Ω / sq. Among them, in the ITO / ATO composite oxide, the molar ratio of In 2 O 3 :SnO 2 :Sb 2 O 5 is 85:10:5. The nano-powder is synthesized by the sol-gel method with a particle size of 50 - 80 nm, and a camouflage pattern with a thickness of 200 - 500 nm is formed by screen printing. The doping concentration gradient varies in different regions (the Sb content ranges from 3% to 8%), achieving zonal regulation of the mid-wave infrared emissivity of 0.3 ± 0.05 in the range of 3 - 5 μm and the long-wave infrared emissivity of 0.6 ± 0.1 in the range of 8 - 14 μm;

[0035] S3: Preparation of the functional coating layer: On the surface of the substrate layer treated in step S2, through sequential plating, a first aluminum plating layer with a thickness of 50 nm and a surface density of about 0.05 g / m 2 is plated first, and then a first boron nitride layer with a thickness of 1 μm and a surface density of about 1.5 g / m 2 is plated to form a functional coating layer;

[0036] S4: Production of the outer layer and the inner layer: The materials completed in step S3 are used as semi-finished products for the outer layer and the inner layer respectively, and are reserved.

[0037] S5: Two-layer composite: The first boron nitride layer of the outer layer and the first boron nitride layer of the inner layer are composite-connected through an adhesive layer with a surface density of 2 g / m 2 . The main body of the adhesive layer is flame-retardant polyurethane glue, and boron nitride filler is added to the flame-retardant polyurethane glue to make its thermal conductivity 0.3 W / m·K, completing the preparation of the multi-band infrared stealth composite material.

[0038] Aramid fibers are characterized by high strength and low density. When blended with conductive fibers, they not only ensure the mechanical properties of the material but also endow it with certain electrical conductivity, which helps to regulate the infrared emissivity. The infrared control printing layer made of ITO / ATO composite oxides realizes the regulation of emissivity by controlling the sheet resistance and utilizing its selective absorption and emission characteristics in the infrared band. The formation of a camouflage pattern can further enhance the stealth effect. The first aluminized layer has good infrared reflection performance, and the first boron nitride layer has high hardness, high temperature resistance, and good thermal stability. The combination of the two improves the comprehensive performance of the material. The substrate layer, in cooperation with the infrared control printing layer and the functional coating layer, reduces the emissivity of the overall material. The flame-retardant polyurethane glue with boron nitride filler as the adhesive layer not only ensures the firm bonding between the two layers but also improves the thermal conductivity and flame-retardant properties of the composite material.

[0039]

[0040] Key performance comparison table

[0041] The areal density of the two-layer multi-band infrared stealth composite material is about 305 g / m 2 , the tensile strength is about 450 MPa, the emissivity at 3 - 5 μm is about 0.22, the emissivity at 8 - 14 μm is about 0.28, and there is no delamination after more than 240 h of resistance to heat and humidity.

[0042] Example 2

[0043] A multi-band infrared stealth composite material, comprising: an outer layer 1 and an inner layer 2. Both the outer layer 1 and the inner layer 2 include a substrate layer 3 and a functional coating layer 4 arranged in sequence from outside to inside. The substrate layer 3 is made of a blend of aramid fibers and conductive fibers. An infrared control printing layer 5 is provided on the surface of the substrate layer 3. The infrared control printing layer is made of ITO / ATO composite oxides. The functional coating layer 4 includes a first aluminized layer 41 and a first boron nitride layer 42 arranged in sequence from outside to inside. The first boron nitride layer 42 of the outer layer 1 and the first boron nitride layer 42 of the inner layer 2 are connected by a composite through an adhesive layer 7. The first aluminized layer 41 and the first boron nitride layer 42 are combined in a sequential plating manner;

[0044] An intermediate layer 6 is provided between the outer layer 1 and the inner layer 2. The intermediate layer 6 includes a PET substrate layer 61, a second aluminized layer 62, and a second boron nitride layer 63 arranged in sequence from top to bottom. The second aluminized layer 62 and the second boron nitride layer 63 are combined in a sequential plating manner.

[0045] A preparation method of a multi-band infrared stealth composite material, comprising the following steps:

[0046] S1: Preparation of the substrate layer: 93% of aramid fibers and 7% of MXene-coated polyester conductive fibers are blended to produce a substrate layer with a surface density of 140 g / m 2

[0047]

[0047] 2 O 3 :SnO 2 :Sb 2 O 5

[0048]

[0048] 2 ;

[0049] S4: Production of the outer layer and the inner layer: The materials completed in step S3 are used as semi-finished products for the outer layer and the inner layer respectively and set aside.

[0050] S5: Preparation of the intermediate layer: After the production of the outer layer and the inner layer in step S4, an intermediate layer is set. On a PET substrate layer with a surface density of 20 g / m 2 2 2

[0051]

[0051] ​S6: Three-layer lamination: The first boron nitride layer on the outer layer and the PET substrate layer in the middle layer are laminated and connected through an adhesive layer. The main body of the adhesive layer is flame-retardant polyurethane glue, and graphene fillers are added to the flame-retardant polyurethane glue. Since there are two connection parts, the areal density of the adhesive layer at each connection part is 2 g / m 2 , with a total of 4 g / m 2 . Make its thermal conductivity > 0.35 W / m·K. The first boron nitride layer on the inner layer and the second boron nitride layer in the middle layer are laminated and connected through an adhesive layer to complete the preparation of the multi-band infrared stealth composite material.

[0052] The setting of the middle layer further enhances the performance of the material. The PET substrate layer has good flexibility and dimensional stability. The combination of the second aluminum plating layer and the second boron nitride layer cooperates with the first aluminum plating layer and the first boron nitride layer in the functional plating layers of the outer layer and the inner layer to achieve an alternating gradient plating combination, further optimizing the reflection and absorption performance of the material in the infrared band.

[0053] Adding graphene fillers to the flame-retardant polyurethane glue improves the thermal conductivity and mechanical properties of the adhesive layer, making the overall performance of the composite material more excellent.

[0054]

[0055]

[0056] Key performance comparison table

[0057] The areal density of the three-layer multi-band infrared stealth composite material is about 309 g / m 2 , the tensile strength is about 490 MPa, the emissivity at 3 - 5 μm is about 0.27, the emissivity at 8 - 14 μm is about 0.33, and the resistance to humidity and heat is > 240 h without delamination.

[0058] The preferred specific embodiments of the present invention have been described in detail above. It should be understood that those of ordinary skill in the art can make many modifications and variations based on the concept of the present invention without creative labor. Therefore, all technical solutions that can be obtained by those skilled in the art in the technical field of the present invention based on the concept of the present invention through logical analysis, reasoning, or limited experiments on the basis of the existing technology should be within the protection scope determined by the claims.

Claims

1. A multi-band infrared stealth composite material, characterized in that: include: The outer layer and the inner layer both include a substrate layer and a functional coating layer sequentially arranged from the outside to the inside, the substrate layer is made of a blend of aramid fiber and conductive fiber, an infrared regulating printing layer is arranged on the surface of the substrate layer, and the infrared regulating printing layer is made of ITO / ATO composite oxide, the functional coating includes a first aluminum coating layer and a first boron nitride layer sequentially arranged from the outside to the inside, the first boron nitride layer of the outer layer and the first boron nitride layer of the inner layer are compositely connected by an adhesive layer, and the first aluminum coating layer and the first boron nitride layer are combined and arranged in a sequential plating manner.

2. The multi-band infrared stealth composite material according to claim 1, characterized in that: An intermediate layer is provided between the outer layer and the inner layer, and the intermediate layer includes a PET substrate layer, a second aluminum coating layer, and a second boron nitride layer arranged in sequence from top to bottom, and the second aluminum coating layer and the second boron nitride layer are combined and arranged in a sequential plating manner.

3. The multi-band infrared stealth composite material according to claim 1, characterized in that: The conductive fiber is silver-plated nylon, copper-plated carbon fiber or MXene-coated polyester material.

4. The multi-band infrared stealth composite material according to claim 1, characterized in that: The aramid fiber accounts for 80-95% of the substrate layer, the conductive fiber accounts for 5-20%, and the substrate layer density is 120-180g / m 2 .

5. The multi-band infrared stealth composite material according to claim 1, characterized in that: The square resistance of the infrared controlled printing layer is less than 100Ω / Sq, and the emissivity range of the formed camouflage pattern partition control is 0.3-0.

7.

6. The multi-band infrared stealth composite material according to claim 1, characterized in that: The thickness of the first aluminum coating layer in the functional coating layer is 30-80 nm, and the thickness of the first boron nitride layer in the functional coating layer is 0.5-2 μm.

7. The multi-band infrared stealth composite material according to claim 2, characterized in that: The thickness of the second aluminum plating layer in the intermediate layer is 30-80 nm, and the thickness of the second boron nitride layer in the intermediate layer is 0.5-2 μm.

8. The multi-band infrared stealth composite material according to claim 1, characterized in that: The adhesive layer is mainly composed of flame-retardant polyurethane adhesive, in which boron nitride or graphene filler is arranged, and the thermal conductivity of the flame-retardant polyurethane adhesive is greater than 0.2 W / m·K.

9. A method for preparing a multi-band infrared stealth composite material according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1: Preparation of the substrate layer: 80-95% of aramid fiber and 5-20% of conductive fiber are blended to form a substrate with a surface density of 120-180g / m 2 The substrate layer; S2: Preparation of infrared control printing layer: using ITO / ATO composite oxide to make infrared control printing layer, and forming camouflage pattern on the surface of the substrate layer prepared in step S1 by screen printing or spraying process; S3: Preparation of functional coating: on the surface of the substrate layer treated in step S2, a first aluminum coating with a thickness of 30-80 nm is firstly coated, and then a first boron nitride layer with a thickness of 0.5-2 μm is coated by sequential coating to form a functional coating; S4: outer layer and inner layer production: the materials obtained in step S3 are used as semi-finished products for the outer layer and the inner layer respectively for later use. S5: Two-layer composite: The outer first boron nitride layer and the inner first boron nitride layer are compositely connected through an adhesive layer to complete the preparation of the multi-band infrared stealth composite material.

10. The method for preparing a multi-band infrared stealth composite material according to claim 9, characterized in that: The following steps are involved: S6: Preparation of the intermediate layer: After the outer layer and the inner layer are prepared in step S4, the intermediate layer is provided. On the PET substrate layer, a second aluminum layer with a thickness of 30-80 nm and a second boron nitride layer with a thickness of 0.5-2 μm are plated in a sequential plating manner to form the intermediate layer; S7: Three-layer composite: The first boron nitride layer of the outer layer is composited and connected with the PET substrate layer of the middle layer through an adhesive layer, and the first boron nitride layer of the inner layer is composited and connected with the second boron nitride layer of the middle layer through an adhesive layer to complete the preparation of the multi-band infrared stealth composite material.

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