Ultra-black surface coating prepared based on double-layer spraying process and method thereof

Abstract

The invention discloses an ultra-black surface coating prepared on the basis of a double-layer spraying process and a method of the ultra-black surface coating. The ultra-black surface coating is composed of a nano-structure surface paint layer, a micron-structure primer layer and a substrate back plate from top to bottom. The manufacturing method is simple, the manufacturing cost is low, and the prepared ultra-black surface coating can achieve the visible light absorption rate gt in the visible light wave band; the quality loss is at the same time of 99.4%; the ultra-black surface has high bonding force and high curved surface adaptability, is enveloped on the surface of a complex-configuration optical system, can adapt to curvature, has small influence on the performance of other subsystems, and reduces the restriction in the design of a novel optical system.

Description

Technical Field

[0001] The invention belongs to the field of aerospace science and technology, and relates to an ultra-black surface coating prepared based on a double-layer spraying process and a method thereof. Background Art

[0002] Spacecraft are one of the most important vehicles for modern deep space exploration, and the optical systems they carry are crucial tools for space research. With technological advancements and the growing demand for exploration, the precision and stability of space optical systems have become crucial specifications for spacecraft. Combined with the growing demand for the integration of diverse detection information across various industries, we urgently need to achieve the fabrication of ultra-black surfaces with high visible light absorption and variable curvature.

[0003] At present, the visible light treatment of space optical systems mostly adopts a combination of optical black paint spraying and shading treatment. However, black paint has problems such as low absorption rate and easy falling off during long-term on-orbit application; the configuration of the light shield itself greatly restricts the development of the ultimate performance of space optical systems. Literature 1 reports an extreme ultra-black coating based on a spray manufacturing method. The core manufacturing method is spraying and natural curing. Its average absorption rate in the visible light band (360-780nm) is 99.8%, but its surface is extremely easy to fall off, which obviously cannot be used for engineering applications. (Yuanhao Jin. Spray coating of aperfect absorber based on carbon nanotube multiscale composites. Carbon 178 (2021) 616-624). Therefore, it is of great scientific and technological significance to research and develop reliable performance variable curvature ultra-black surface films for space optical systems. Summary of the Invention

[0004] To address the weak bonding and poor rigid-flexible coupling capabilities of existing ultra-black visible light surfaces, the present invention provides an ultra-black surface coating and method for producing it using a double-layer spray coating process. This invention utilizes a visible light ultra-black surface structure of "nanostructured topcoat + microstructured primer" and creatively employs a double-layer spray coating process to produce a variable-curvature visible light ultra-black surface coating with excellent surface compatibility and visible light absorption.

[0005] The technical solution of the present invention is:

[0006] The ultra-black surface coating prepared based on the double-layer spraying process consists of a nanostructured topcoat layer, a microstructured primer layer and a base backplane from top to bottom. The nanostructured topcoat layer is composed of randomly distributed carbon-based nanostructures, and the particle size of the randomly distributed carbon-based nanostructures is 5 to 20 nm. The microstructured primer layer is composed of randomly distributed carbon-based microstructures, and the particle size of the randomly distributed carbon-based microstructures is 20 to 100 μm. The thickness of the ultra-black surface coating is 50 to 200 μm.

[0007] Furthermore, the surface of the ultra-black surface coating can absorb visible light in the 380nm to 760nm band, and the absorption mode is one or more of disordered microstructure light traps and plasmon resonance.

[0008] Furthermore, the surface paint material of the nanostructured surface paint layer is a hybrid carbon material that can be used in space, such as one or more of carbon nanotubes, carbon black, and carbon cluster structures, and the surface paint carrier is an oily solution with similar polarity to the material, such as polyetheretherketone, butyl acetate, polyurethane polymers, etc.

[0009] Furthermore, the primer material of the micron-structured primer layer is a hybrid carbon material that can be used in space, such as one or more of carbon nanotubes, carbon black, and carbon cluster structures, and the primer carrier is an oily solution with similar polarity to the material, such as cyclohexanone, ethanol, polyurethane polymers, etc.

[0010] Furthermore, the base material in the base backplane is a special insulating polymer material that can be used in space, such as polyimide, PDMS, FR4, etc.

[0011] The method for preparing the above-mentioned ultra-black surface coating using a double-layer spraying process comprises the following steps:

[0012] (1) Using an ultra-precision spray gun to spray a micron-structured primer layer on the surface of the substrate backplane;

[0013] (2) preliminarily drying the surface of the microstructured primer layer, and then covering the surface of the microstructured primer layer with a nanostructured topcoat layer using a double-layer manufacturing process, and curing the topcoat layer;

[0014] (3) The double-layer spray-coated ultra-black surface prepared above is subjected to heat treatment to obtain an ultra-black surface coating.

[0015] Furthermore, in step (1), the ultra-precision spray gun processing method is a common processing method in the art, such as plasma spraying, cold spraying, electrostatic spraying, conventional spraying, etc.

[0016] Furthermore, in step (2), the temperature of the preliminary surface drying is 150°C to 200°C, and the curing temperature is 50°C to 200°C.

[0017] Compared with the prior art, the present invention has the following advantages:

[0018] (1) The ultra-black surface coating of the present invention can achieve a visible light absorption rate of >99.4% in the visible light band while maintaining a mass loss of <0.5%, thereby achieving high bonding strength and high surface adaptability of the ultra-black surface. When it is encapsulated on the surface of a complex optical system, it can adapt to the curvature and has little impact on the performance of other subsystems, thereby reducing the constraints in the design of new optical systems.

[0019] (2) The manufacturing method of the present invention is simple, has low manufacturing cost, and has the adaptability to large-area surfaces with complex curvatures. Compared with the traditional black paint manufacturing and curing method, the manufacturing efficiency is significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the structure of the ultra-black surface coating prepared based on the double-layer spraying process;

[0021] Figure 2 This is a physical picture of the ultra-black surface coating prepared in Example 1.

[0022] Figure 3 This is a physical picture of the ultra-black surface coating prepared in Comparative Example 1.

[0023] Figure 4 This is a physical picture of the ultra-black surface coating prepared in Comparative Example 2. DETAILED DESCRIPTION

[0024] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described below with reference to specific implementation cases and drawings, but the examples given are not intended to limit the invention.

[0025] Example 1

[0026] The ultra-black surface coating is prepared based on a double-layer spraying process, which includes the following steps:

[0027] (1) Using an ultra-precision spray gun to spray a micron-structured primer layer on the surface of the substrate backplane, the spray gun pressure is set to 0.3 MPa, the spray gun diameter is 0.5 mm, the solution viscosity is less than 60 MPa, and the homogenization method is a circular grinding stirring supplemented by ultrasonic dispersion;

[0028] (2) preliminarily drying the microstructured primer layer, with the surface drying temperature set at 160°C, and then covering the surface of the microstructured primer layer with a nanostructured topcoat layer using a double-layer manufacturing process and curing the nanostructured topcoat layer at a curing temperature between 80°C and 100°C;

[0029] (3) The double-layer spray-coated ultra-black surface prepared above is subjected to heat treatment at a temperature of 200° C. to eliminate internal stress and obtain an ultra-black surface coating.

[0030] like Figure 2 The surface shown is an ultra-black surface produced by a double-layer spraying process. The surface quality is intact and the absorption rate meets the requirements.

[0031] Comparative Example 1

[0032] This comparative example is basically the same as Example 1, except that only one microstructured primer layer is prepared. Figure 3 As shown, it can be seen that the phenomenon of insufficient absorption rate obviously occurs, which is physically characterized as not being black enough.

[0033] Comparative Example 2

[0034] This comparative example is basically the same as Example 1, except that the thermal curing temperature is different and is set to 160°C. Figure 4 As shown, it can be seen that cracks and peeling appear on the surface, and the surface quality is not up to standard.

[0035] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. Ultra-black surface coating prepared by double-layer spraying process, characterized in that: From top to bottom, it is composed of a nanostructured topcoat layer, a microstructured primer layer and a base backplane. The nanostructured topcoat layer is composed of randomly distributed carbon-based nanostructures with a particle size of 5 to 20 nm. The microstructured primer layer is composed of randomly distributed carbon-based microstructures with a particle size of 20 to 100 μm. The thickness of the ultra-black surface coating is 50 to 200 μm.

2. The ultra-black surface coating according to claim 1, characterized in that The surface of the ultra-black surface coating can absorb visible light in the 380nm~760nm band, and the absorption mode is one or more of disordered microstructure light trap and plasmon resonance.

3. The ultra-black surface coating according to claim 1, characterized in that The surface paint material of the nanostructured surface paint layer is a hybrid carbon material that can be used in space, and the surface paint carrier is an oily solution with a polarity similar to that of the material; the primer material of the microstructured primer layer is a hybrid carbon material that can be used in space, and the primer carrier is an oily solution with a polarity similar to that of the material.

4. The ultra-black surface coating according to claim 3, characterized in that The surface paint material of the nanostructured surface paint layer is one or more of carbon nanotubes, carbon black, and carbon cluster structures, and the surface paint carrier is polyetheretherketone, butyl acetate or polyurethane polymer; the primer material of the microstructured primer layer is one or more of carbon nanotubes, carbon black, and carbon cluster structures, and the primer carrier is cyclohexanone, ethanol or polyurethane polymer.

5. The ultra-black surface coating according to claim 1, characterized in that The base material in the base backplane is a special insulating polymer material that can be used in space.

6. The ultra-black surface coating according to claim 5, characterized in that The substrate material in the substrate backplane is polyimide, PDMS or FR4.

7. A method for preparing the ultra-black surface coating according to any one of claims 1 to 6 using a double-layer spraying process, characterized in that: The following steps are involved: (1) Use ultra-precision spray gun to spray a micron structure primer layer on the surface of the substrate backplane; (2) Preliminary surface drying of the microstructured primer layer is performed, and then a nanostructured topcoat layer is covered on the surface of the microstructured primer layer using a double-layer manufacturing process and cured; (3) The double-layer spray-coated ultra-black surface prepared above is subjected to heat treatment to obtain an ultra-black surface coating.

8. The method according to claim 7, characterized in that In step (1), the ultra-precision spray gun processing method is plasma spraying, cold spraying, electrostatic spraying or conventional spraying.

9. The method according to claim 7, characterized in that In step (2), the temperature for preliminary surface drying is 150°C to 200°C, and the curing temperature is 50°C to 200°C.

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