Extinction material and preparation method thereof

Abstract

The invention relates to a matting material and a preparation method thereof. The preparation method comprises the following steps: (1) directional arrangement: bonding a fiber bundle and an uncured adhesive film according to an orientation angle theta to obtain a unit layer; (2) fixed-height cutting: carrying out fixed-height cutting on the unit layers in the step (1) by adopting cutting equipment to obtain'fiber bundle-adhesive film 'structural units; (3) laminating and laying: laying a plurality of layers of'fiber bundle-adhesive film 'structural units in the step (2) together to obtain a laminated structure; and (4) curing and forming: curing the laminated structure in the step (3) to obtain the extinction material. The orientation angle of the extinction fiber array can be precisely designed and controlled, and therefore efficient absorption of incident light at a specific angle is achieved.

Description

Technical Field

[0001] This invention relates to the field of functional matting materials technology, and in particular to a matting material and its preparation method. Background Technology

[0002] Extinction materials possess high visible light absorption rates and are widely used in precision spectrometers, infrared detection systems, and visible light cameras. Array-type extinction materials (such as carbon nanotube arrays and microfiber arrays) generally consist of an array structure with a fixed arrangement perpendicular to the substrate (in this case, the array orientation angle is 90°). Figure 1 As shown, when the incident light is incident roughly along the direction perpendicular to the substrate (with a very small incident angle), the incident light enters the array structure and is gradually consumed through multiple reflections and absorptions within the array structure, thus exhibiting high light absorption efficiency. However, when the incident light angle is large, especially under large grazing angle conditions (incident angle greater than 70°), the incident light is generally reflected off the array sidewalls and has difficulty entering the array interior, causing the light trap to fail and resulting in a significant decrease in the material's light absorption rate at large incident angles. For example, CN110947594A discloses a short-cut fiber vertical array extinction material prepared by high-voltage electrostatic flocking technology, which has a high absorption rate in the visible light range, but the fiber array is vertically oriented, and this structure has insufficient absorption capacity for incident light at large grazing angles. CN119535656A discloses an ultra-black coating with a randomly oriented light trap structure, which improves the wide-angle absorption capability of the coating to a certain extent. However, analysis of electron micrographs shows that light traps prepared by spraying technology generally have a very low aspect ratio, indicating that their extinction capability is insufficient. In fact, the reported coating absorption rate does not reach 99%.

[0003] Therefore, how to design and precisely control the orientation angle of the extinction array structure according to the characteristics of the incident light angle distribution in the application scenario, so as to enhance its absorption capacity for incident light (especially grazing light) at a specific angle, has become an urgent problem to be solved in the field of extinction materials. Summary of the Invention

[0004] To address the aforementioned technical problems, the present invention aims to provide an extinction material and its preparation method. By bonding fiber bundles with specific orientation angles onto an adhesive film, a fiber array extinction material with precisely controllable fiber orientation angles is prepared. This enables the material to achieve high-efficiency extinction within the target incident angle range, solving the problem of high reflection of light rays with large grazing angle incident light in existing extinction array materials where the array direction is perpendicular to the substrate.

[0005] To achieve this objective, the present invention adopts the following technical solution: In a first aspect, the present invention provides a method for preparing an matting material, the method comprising the following steps: (1) Oriented arrangement: The fiber bundles and the uncured adhesive film are bonded together at an orientation angle θ to obtain a unit layer; (2) Fixed height cutting: The unit layer of step (1) is cut at a fixed height using a cutting device to obtain the "fiber bundle-film" structural unit; (3) Laying up: Laying up the multi-layer "fiber bundle-film" structural units described in step (2) together to obtain a laminated structure; (4) Curing and molding: The laminated structure described in step (3) is cured to obtain the matte material.

[0006] In this invention, fiber bundles are bonded to the surface of the adhesive film, allowing for precise control of the fiber bundle orientation angle. Specifically, the preparation method of the matting material of this invention is as follows: Figure 2 As shown, the process sequentially includes directional arrangement, fixed-height cutting, layering and laying, and curing. Compared to traditional methods such as flocking, laser etching, or chemical etching, the matting material preparation method of this invention combines directional arrangement with fixed-height cutting, enabling the design and controllable preparation of the fiber array orientation angle and height parameters, thus avoiding the problem of uncontrollable orientation in traditional structures. This method has a simple process flow. Furthermore, this invention has strong adaptability to fiber material systems, and can effectively absorb light from different incident directions and wavelengths by adjusting the fiber type and structural parameters, ensuring good structural stability while maintaining light absorption performance.

[0007] Preferably, the orientation angle θ is 0°-90°, for example, it can be 10°, 20°, 30°, 40°, 45°, 50°, 60°, 70° or 80°.

[0008] In this invention, the orientation angle θ is the angle between the fiber bundle and the uncured adhesive film, ranging from 0° to 90°.

[0009] Preferably, the orientation angle θ is determined based on the incident light angle α, where the incident light angle α is 0°-90° and the orientation angle θ is (90°-α).

[0010] In this invention, the incident light angle α refers to the angle between the incident light and the plane perpendicular to the uncured adhesive film, which is 0°-90°.

[0011] Preferably, the fiber bundle is made of any one or a combination of at least two of carbon fiber, glass fiber, ceramic fiber, metal fiber or polymeric organic fiber.

[0012] In this invention, different types of fiber materials exhibit varying absorption behaviors of incident light under the same array structure conditions due to differences in their intrinsic optical constants, microstructure, and surface morphology. Carbon fiber, with its high intrinsic absorption capacity in the visible-near-infrared band, is suitable for efficient extinction of light across a wide wavelength range. Glass fiber, ceramic fiber, and metal fiber can also achieve effective absorption in specific wavelength ranges through multiple scattering and optical path extension effects of the array structure. By rationally selecting fiber material types and combining them with the orientation angle and height control structure described in this invention, the applicability of extinction materials in different wavelength ranges and application scenarios can be further expanded.

[0013] Preferably, the fiber bundle contains 5,000-20,000 monofilaments, such as 7,000, 10,000, 12,000, 15,000 or 18,000 monofilaments.

[0014] Preferably, the diameter of the monofilament is 3-15 μm, for example, it can be 5 μm, 8 μm, 10 μm, 12 μm or 14 μm.

[0015] Preferably, the fiber bundle has undergone additive or subtractive processing.

[0016] In this invention, additive or subtractive processing of the fiber bundle can increase the roughness of the fiber surface, thereby enhancing the fiber's scattering characteristics and absorption rate.

[0017] Preferably, the adhesive film material includes any one or a combination of at least two of epoxy resin, phenolic resin, acrylic resin, or silicone rubber.

[0018] Preferably, the thickness of the uncured adhesive film is 0.01-0.1 mm, for example, it can be 0.02 mm, 0.04 mm, 0.05 mm, 0.06 mm or 0.08 mm.

[0019] Preferably, the height-fixed cutting method includes any one or a combination of at least two of laser cutting, mechanical cutting, water jet cutting, or ultrasonic cutting.

[0020] Preferably, the curing method includes any one or a combination of at least two of the following: heat curing, ultraviolet curing, or microwave curing.

[0021] Preferably, during the curing process, pressure is applied to the laminated structure along the thickness direction.

[0022] In this invention, applying pressure to the laminated structure during curing can improve the bonding strength.

[0023] In a second aspect, the present invention provides a matting material, which is prepared by the preparation method described in the first aspect.

[0024] Preferably, the height of the "fiber bundle-film" structural unit of the matting material is 0.5-20 mm, for example, it can be 1 mm, 3 mm, 5 mm, 8 mm, 10 mm, 15 mm or 18 mm, etc.

[0025] Preferably, the thickness of the stacked structure is 3cm-1m, for example, it can be 5cm, 10cm, 20cm, 30cm, 40cm, 50cm, 60cm, 70cm, 80cm or 90cm, etc.

[0026] Compared with the prior art, the present invention has at least the following beneficial effects: The orientation angle of the extinction fiber array of the present invention can be precisely designed and controlled, thereby achieving efficient absorption of incident light at a specific angle (especially incident light at a large grazing angle). Attached Figure Description

[0027] Figure 1 The relationship between the incident light angle and the fiber array direction is as follows: a) small incident angle vs. vertical array, b) large incident angle vs. vertical array, c) small incident angle vs. tilted array, d) large incident angle vs. tilted array.

[0028] Figure 2 This is a schematic diagram of the preparation method of the matting material of the present invention.

[0029] Figure 3 Scanning electron microscope images of the sides of the matting material: a) Fiber array material with an orientation angle of 90°; b) Fiber array material with an orientation angle of 45°; c) Fiber array material with an orientation angle of 15°.

[0030] Figure 4 The value represents the hemispherical absorptivity of the extinction material at different incident angles (incident wavelength 500 nm). Detailed Implementation

[0031] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. However, the following examples are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims.

[0032] The sources of some of the raw materials used in the preparation of this invention are as follows: The carbon fiber bundles (LSCF-35mm) were purchased from Shanghai Lishuo Composite Materials Technology Co., Ltd.

[0033] The epoxy film (EC0711) was purchased from Shenzhen Tutmei Polymer Materials Co., Ltd.

[0034] Example 1 This embodiment provides a matting material and its preparation method. The preparation method of the matting material includes the following steps: (1) Oriented arrangement: Carbon fiber bundles containing 10,000-12,000 monofilaments (monofilament diameter 6-7 μm) are alternately layered with epoxy film with a thickness of 0.03 mm, and the fiber bundle orientation angle is controlled to be 90°. (2) Fixed height cutting: The above structure is cut into structural units with a length of 1 mm using a laser cutting device with a power of 15 W and a cutting speed of 200 mm / s; (3) Laying in layers: Lay in 50 layers of “fiber bundle-film” structural units that have been cut to a fixed height, with the fiber orientation consistent. (4) Curing: The above-mentioned laminated structure is heat-cured at 150°C for 30 min to obtain the matte material.

[0035] Example 2 This embodiment provides an matting material and its preparation method, which differs from Embodiment 1 only in that the fiber bundle orientation angle is 45°.

[0036] Example 3 This embodiment provides an matting material and its preparation method, which differs from Embodiment 1 only in that the fiber bundle orientation angle is 15°.

[0037] Comparative Example 1 This comparative example provides a matting material and its preparation method. The preparation method of the matting material includes the following steps: Comparative Example 1 uses the existing high-voltage electrostatic flocking method to prepare a fiber array matting material. Specifically, short-cut carbon fibers are sieved and placed in a high-voltage electrostatic device. Adhesive is pre-coated on the substrate surface. Under the action of a high-voltage electric field, the short-cut fibers fly perpendicularly to the substrate surface along the electric field direction and solidify to form a fiber array structure. Subsequently, the obtained fiber array is cured and subjected to necessary surface treatment to obtain the fiber array matting material.

[0038] Although the overall fiber orientation in the fiber array prepared by the above method is dominated by the electric field direction, achieving a quasi-vertical arrangement on a macroscopic scale, the microscopic arrangement of the fiber array still exhibits a certain degree of disorder. The angular deviation of individual fibers is quite significant, making it difficult to form a highly uniform and ordered structure, and the degree of orientation is difficult to control precisely. Furthermore, because the structural parameters (height, orientation angle) of the array prepared by this method are strongly correlated and coupled with the process parameters (electric field strength, fiber type), it is difficult to independently adjust the orientation angle and height parameters of the fiber array, thus limiting its potential for structural optimization.

[0039] Test methods Light absorption rate: The reflection spectrum of the above-mentioned extinction material at different incident angles was measured using a spectrophotometer equipped with an integrating sphere, and the hemispherical light absorption rate of the extinction material (incident wavelength: 500 nm) was calculated.

[0040] The test results are shown in Table 1.

[0041] Table 1 The test results show that: (1) As can be seen from Examples 1-3, the present invention precisely controls the orientation angle of the fiber bundles by bonding fiber bundles to the surface of the adhesive film, thereby regulating the spatial arrangement structure of the fiber array, so that the prepared matting material exhibits high light absorption capacity under the corresponding incident conditions.

[0042] (2) As can be seen from the comparison of Examples 1-3, by further limiting the orientation angle θ, the present invention can achieve a light absorption rate of over 99.5% for incident light with wavelengths of 300-2000 nm and a specific incident angle. Scanning electron microscope images of the side surface of the extinction material in Examples 1-3 of the present invention are shown below. Figure 3 As shown. The light absorption rates of the matting materials in Examples 1-3 are as follows. Figure 4 As shown, the matting material with a fiber orientation angle of 90° has the highest light absorption rate at an incident angle of 0°, reaching 99.5%; the matting material with a fiber orientation angle of 45° has the highest light absorption rate at an incident angle of 40°, reaching 99.5%; and the matting material with a fiber orientation angle of 15° has the highest light absorption rate at an incident angle of 80°, reaching 99.5%. The matting material of the present invention achieves efficient absorption of incident light at specific angles.

[0043] (3) By comparing Example 1 and Comparative Example 1, it can be seen that the material obtained by the traditional extinction material preparation method lacks effective control of fiber structure orientation, the overall light absorption rate is difficult to reach a high level, and the light absorption performance decreases under large incident angle conditions. In contrast, the present invention can improve the light absorption performance of the material under large incident angle conditions and maintain a high light absorption performance by designing and controlling the fiber array orientation angle.

[0044] In summary, this invention achieves efficient absorption of incident light at a specific angle by precisely designing and controlling the orientation angle of the extinction fiber array.

[0045] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for preparing a matting material, characterized in that, The preparation method includes the following steps: (1) Oriented arrangement: The fiber bundles and the uncured adhesive film are bonded together at an orientation angle θ to obtain a unit layer; (2) Fixed height cutting: The unit layer of step (1) is cut at a fixed height using a cutting device to obtain the "fiber bundle-film" structural unit; (3) Laying up: Laying up the multi-layer "fiber bundle-film" structural units described in step (2) together to obtain a laminated structure; (4) Curing and molding: The laminated structure described in step (3) is cured to obtain the matte material.

2. The preparation method according to claim 1, characterized in that, The orientation angle θ is 0°-90°; Preferably, the orientation angle θ is determined based on the incident light angle α, where the incident light angle α is 0°-90° and the orientation angle θ is (90°-α).

3. The preparation method according to claim 1 or 2, characterized in that, The fiber bundle is made of any one or a combination of at least two of the following: carbon fiber, glass fiber, ceramic fiber, metal fiber, or high molecular organic fiber.

4. The preparation method according to any one of claims 1-3, characterized in that, The fiber bundle contains 5,000-20,000 monofilaments; Preferably, the diameter of the monofilament is 3-15 μm.

5. The preparation method according to any one of claims 1-4, characterized in that, The fiber bundles are processed by additive or subtractive manufacturing.

6. The preparation method according to any one of claims 1-5, characterized in that, The adhesive film material includes any one or a combination of at least two of epoxy resin, phenolic resin, acrylic resin or silicone rubber. Preferably, the thickness of the uncured adhesive film is 0.01-0.1 mm.

7. The preparation method according to any one of claims 1-6, characterized in that, The height-fixed cutting method includes any one or a combination of at least two of laser cutting, mechanical cutting, water jet cutting, or ultrasonic cutting.

8. The preparation method according to any one of claims 1-7, characterized in that, The curing method includes any one or a combination of at least two of the following: thermal curing, ultraviolet curing, or microwave curing. Preferably, during the curing process, pressure is applied to the laminated structure along the thickness direction.

9. A matting material, characterized in that, The matting material is prepared by the preparation method according to any one of claims 1-8.

10. The matting material according to claim 9, characterized in that, The height of the "fiber bundle-film" structural unit of the matting material is 0.5-20 mm.

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