Preparation method of high-efficiency wide-spectrum infrared absorption coating

Abstract

The invention discloses a preparation method of a high-efficiency wide-spectrum infrared absorption coating, which comprises the following steps of: performing pretreatment such as grinding, polishing and the like on a thermoelectric ceramic substrate; the preparation method comprises the following steps: uniformly dispersing micro-nano carbon, TiN and Si3N4 nanoparticles, a dispersing agent, a diluent, a binder and the like by adopting a method of combining physical dispersion and chemical dispersion by utilizing the dispersing agent, and blending into spraying slurry; and uniformly spraying the prepared spraying slurry on the surface of a pretreated thermoelectric ceramic substrate by using an electrostatic spraying method, and curing to obtain the wide-spectrum absorbing coating. The absorption coating can be used as an infrared absorption coating and can be used for devices such as an infrared detector, a laser energy meter or a thermal radiation detector.

Description

Technical Field

[0001] This invention relates to a method for preparing an absorption coating, particularly a method for preparing a high-efficiency broadband infrared absorption coating. The prepared coating can be used in devices such as infrared detectors, laser energy meters, or thermal radiation detectors. Background Technology

[0002] Lasers, with their advantages of high energy density, high monochromaticity, high directionality, and high coherence, are widely used in industry, defense, scientific research, and medicine. To better utilize laser technology, accurate measurement of laser parameters (such as energy and power) is crucial. A common method for laser energy measurement is based on the photothermal effect, which utilizes the thermal effect of the laser to convert light energy into heat energy through an absorbing coating, and then calculates the laser energy by measuring temperature changes or other physical quantities. The performance of the absorbing coating directly affects the sensitivity and accuracy of the measurement. Laser wavelengths cover multiple bands from ultraviolet to infrared, with infrared lasers (1.3-10.6 micrometers) often used in communications and other fields due to their low-loss characteristics. Developing efficient and stable absorbing coatings is of great significance for improving the accuracy and reliability of photothermal measurements.

[0003] Absorbing coatings are key materials for efficiently absorbing laser energy and are widely used in fields such as laser energy measurement. Currently, mainstream absorbing coating materials include gold black, soot black, and colloidal graphite. Each material has its advantages and disadvantages: Gold black: high absorption efficiency, wide absorption band, and stable performance, but high cost and complex preparation process, requiring vapor deposition under a protective atmosphere, making large-scale application difficult. Soot black: relatively simple to prepare and low cost, but poor heat resistance, easily burned off at high temperatures, leading to white spots in the absorption layer and affecting measurement accuracy. Colloidal graphite: possesses good absorption performance and certain heat resistance, but its absorption efficiency and stability are not as good as gold black, and it is prone to structural changes under high-power lasers. Although metallic black materials such as gold black have excellent absorption performance, their cost and process limitations make large-scale application difficult. Therefore, developing novel absorbing coating materials to improve absorption efficiency and efficient heat transfer characteristics to enhance their heat resistance is an important research direction.

[0004] Currently, research and applications of infrared absorbing coatings mainly focus on specific wavelengths (such as near-infrared or mid-infrared) or specific environmental conditions, but coatings that can truly achieve broadband infrared absorption are still relatively rare. For example, Chinese patent ZL201210093256.2 utilizes reduced graphene oxide and ethylene-vinyl acetate copolymer to prepare a broadband solar energy absorbing coating via solvent coating or melt pressing; Chinese patent 201511005884.0 grows semiconductor optical coating films on metal substrates using methods such as magnetron sputtering, covering a wavelength range of 400–1800 nm. In addition, many studies focus on infrared absorbing coatings in specific wavelengths, such as Chinese patent ZL201410105234.2, which prepares photothermal conversion coatings using ultrafine mica powder as raw material; the literature "Ni Yaru et al." uses Fe2O3 and other fillers in combination with binders to prepare infrared absorbing coatings; and the literature "Zhang Weigang et al." prepared a polyurethane / Sm2O3 composite coating, exhibiting strong absorption characteristics for specific near-infrared light. Other common coatings include gold-black coatings (high absorption efficiency but high cost and complex process), graphite coatings (simple to prepare but poor heat resistance), and composite material coatings (improving performance through the combination of multiple materials).

[0005] It should be noted that the information disclosed in this background section is only for understanding the background technology of this application concept, and therefore may include information that does not constitute prior art. Summary of the Invention

[0006] This disclosure provides at least one method for preparing a high-efficiency broadband infrared absorbing coating.

[0007] In a first aspect, embodiments of this disclosure provide a method for preparing a high-efficiency broadband infrared absorption coating, comprising the following steps:

[0008] Step S1 involves pre-treating the thermoelectric ceramic substrate by grinding and polishing.

[0009] Step S2 involves using a combination of physical dispersion and chemical dispersion with a dispersant to uniformly disperse micro / nano carbon, TiN and Si3N4 nanoparticles, dispersant, diluent and binder, and prepare a spraying slurry.

[0010] Step S3: The prepared spray slurry is uniformly sprayed onto the pretreated thermoelectric ceramic substrate surface using an electrostatic spraying method. After curing, a broadband absorption coating is obtained.

[0011] In one optional embodiment, the percentage content of the spray slurry composition is as follows: micro / nano carbon: 30%–50%; TiN nanoparticles: 20%–30%; Si3N4 nanoparticles: 20%–30%; dispersant: 5%–10%; diluent: 5%–10%; binder: 10%–20%.

[0012] In one optional embodiment, the micro / nano carbon has a particle size of 0.1–1 μm, and the TiN and Si3N4 nanoparticles have a particle size of 10–100 nm.

[0013] In one alternative embodiment, the physical dispersion method is ultrasonic dispersion or mechanical stirring dispersion.

[0014] In one alternative embodiment, the physical dispersion time of the micro / nano carbon, TiN, and Si3N4 nanoparticles is 30–120 minutes.

[0015] In one optional embodiment, the dispersant is a polycarboxylate dispersant, a polyether-modified polysiloxane dispersant, or an organosilicon dispersant, and the amount of dispersant added is 5%–20% of the amount of micro / nano carbon added.

[0016] In one alternative embodiment, the diluent is dodecyl to tetradecyl glycidyl ether, and the binder is polyvinyl alcohol or epoxy resin.

[0017] In one optional embodiment, the spraying voltage is 30–40kV, the spraying distance is 15–25cm, the spraying speed is 10–15cm / s, and the thickness of the absorbent coating is 20–200μm.

[0018] The beneficial effects of this invention are that it differs significantly in material selection and process. It also possesses excellent heat resistance and efficient heat transfer characteristics, and the process is simple and low-cost, exhibiting significant material and process advantages, thus providing a new direction for the development of infrared absorbing coatings.

[0019] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention are realized and obtained in accordance with the structures particularly pointed out in the description, claims and drawings.

[0020] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0021] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0022] Figure 1 A flowchart illustrating a method for preparing a high-efficiency broadband infrared absorbing coating, as provided in this embodiment of the disclosure. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Research has shown that absorbing coatings are key materials for efficiently absorbing laser energy and are widely used in fields such as laser energy measurement. Currently, mainstream absorbing coating materials include gold black, soot black, and colloidal graphite. Each material has its advantages and disadvantages: Gold black: high absorption efficiency, wide absorption band, and stable performance, but high cost and complex preparation process, requiring vapor deposition under a protective atmosphere, making large-scale application difficult. Soot black: relatively simple to prepare and low cost, but poor heat resistance, easily burned off at high temperatures, leading to white spots in the absorption layer and affecting measurement accuracy. Colloidal graphite: possesses good absorption performance and certain heat resistance, but its absorption efficiency and stability are not as good as gold black, and it is prone to structural changes under high-power lasers. Although metallic black materials such as gold black have excellent absorption performance, their cost and process limitations make large-scale application difficult. Therefore, developing novel absorbing coating materials to improve absorption efficiency and efficient heat transfer characteristics to enhance their heat resistance is an important research direction.

[0025] Currently, the research and application of infrared absorbing coatings mainly focus on specific wavelengths (such as near-infrared or mid-infrared) or specific environmental conditions, but coatings that can truly achieve broadband infrared absorption are still relatively rare.

[0026] The shortcomings of the above solutions are the result of the inventor's practical experience and careful research. Therefore, the discovery process of the above problems and the solutions proposed in this disclosure below should be considered as the inventor's contribution to this disclosure.

[0027] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the embodiments and features described below can be combined with each other. Furthermore, in the accompanying drawings, the thickness of components may be exaggerated or reduced for the purpose of effectively describing the technical content.

[0028] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0029] Based on the above research, this disclosure provides a method for preparing a high-efficiency broadband infrared absorption coating, specifically including the following steps: (1) pre-treating the thermoelectric ceramic substrate by grinding and polishing; (2) uniformly dispersing micro-nano carbon, TiN and Si3N4 nanoparticles, dispersant, diluent and binder by a combination of physical dispersion and chemical dispersion using a dispersant, and preparing a spraying slurry; (3) uniformly spraying the prepared spraying slurry onto the surface of the pre-treated thermoelectric ceramic substrate using an electrostatic spraying method, and obtaining a broadband absorption coating after curing.

[0030] The percentage content of the spraying slurry of the present invention is as follows: micro-nano carbon: 30%–50%; TiN nanoparticles: 20%–30%; Si3N4 nanoparticles: 20%–30%; dispersant: 5%–10%; diluent: 5%–10%; binder: 10%–20%.

[0031] The micro / nano carbon particles described in this invention have a particle size of 0.1–1 μm, and the TiN and Si3N4 nanoparticles have a particle size of 10–100 nm.

[0032] The physical dispersion method described in this invention is ultrasonic dispersion or mechanical stirring dispersion.

[0033] The physical dispersion time of the micro / nano carbon, TiN and Si3N4 nanoparticles described in this invention is 30–120 minutes.

[0034] The dispersant described in this invention is a polycarboxylate dispersant (such as Disperbyk-161 or Disperbyk-180), a polyether-modified polysiloxane dispersant (such as BYK-P104 or BYK-P105), or an organosilicon dispersant (such as BYK-348 or BYK-349). The amount of dispersant added is 5%–20% of the amount of micro / nano carbon added.

[0035] The diluent described in this invention is dodecyl to tetradecyl glycidyl ether.

[0036] The adhesive described in this invention is polyvinyl alcohol or epoxy resin.

[0037] The spraying voltage, spraying distance, and spraying speed parameters described in this invention are 30–40kV, 15–25cm, and 10–15cm / s.

[0038] The thickness of the absorbent coating formed by the spraying material described in this invention is 20–200 μm.

[0039] In Case Study 1, step S1 involves grinding and polishing the thermoelectric ceramic substrate to ensure a smooth and clean surface, thereby improving the adhesion of the coating.

[0040] Step S2: Weigh out 40% micro / nano carbon (0.1–1 μm particle size), 25% TiN nanoparticles (10–100 nm particle size), and 25% Si3N4 nanoparticles (10–100 nm particle size). Add 10% of the added micro / nano carbon dispersant Disperbyk-161 using a polycarboxylate dispersant. Disperse using ultrasound for 45 minutes to ensure uniform dispersion of the nanoparticles. Add 5% dodecyl glycidyl ether as a diluent. Add 15% epoxy resin as a binder. Stir until homogeneous to form a stable spray coating slurry.

[0041] Step S3: Using an electrostatic spraying method, the prepared spraying slurry is uniformly sprayed onto the surface of the pretreated thermoelectric ceramic substrate.

[0042] Spraying parameters: spraying voltage 35kV, spraying distance 20cm, spraying speed 12cm / s. After spraying, the coating is cured at 80℃ for 2 hours to form a broadband infrared absorption coating. By controlling the number of spray layers and the spraying time, the final coating thickness is 50μm.

[0043] In Implementation Case 2, step S1 involves grinding and polishing the thermoelectric ceramic substrate to ensure a smooth and clean surface, thereby improving the adhesion of the coating.

[0044] Step S2: Weigh out 30% micro / nano carbon (0.1–1 μm particle size), 30% TiN nanoparticles (10–100 nm particle size), and 30% Si3N4 nanoparticles (10–100 nm particle size). Add 15% of the amount of polyether-modified polysiloxane dispersant BYK-P104. Disperse using mechanical stirring for 60 minutes to ensure uniform dispersion of the nanoparticles. Add 10% dodecyl glycidyl ether as a diluent. Add 20% polyvinyl alcohol as a binder. Stir until homogeneous to form a stable spray slurry.

[0045] Step S3: Using an electrostatic spraying method, the prepared spraying slurry is uniformly sprayed onto the surface of the pretreated thermoelectric ceramic substrate.

[0046] Spraying parameters: spraying voltage 30kV, spraying distance 15cm, spraying speed 10cm / s. After spraying, the coating is cured at 70℃ for 3 hours to form a broadband infrared absorption coating. By controlling the number of spray layers and the spraying time, the final coating thickness is 100μm.

[0047] In implementation case 3, step S1 involves grinding and polishing the thermoelectric ceramic substrate to ensure a smooth and clean surface, thereby improving the adhesion of the coating.

[0048] Step S2: Weigh out 50% micro / nano carbon (0.1–1 μm particle size), 20% TiN nanoparticles (10–100 nm particle size), and 20% Si3N4 nanoparticles (10–100 nm particle size). Add organosilicon dispersant BYK-348, at a rate of 5% of the added micro / nano carbon. Disperse using ultrasound for 30 minutes to ensure uniform dispersion of the nanoparticles. Add 5% dodecyl glycidyl ether as a diluent. Add 10% epoxy resin as a binder. Stir until homogeneous to form a stable spray coating slurry.

[0049] Step S3: Using electrostatic spraying, the prepared spray slurry is uniformly sprayed onto the pretreated thermoelectric ceramic substrate surface. Spraying parameters: spraying voltage 40kV, spraying distance 25cm, spraying speed 15cm / s. After spraying, the coating is cured at 90℃ for 1.5 hours to form a broadband infrared absorption coating. By controlling the number of spray layers and the spraying time, the final coating thickness is 200μm.

[0050] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. Furthermore, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Based on the above-described ideal embodiments of the present invention, and through the above description, those skilled in the art can make various changes and modifications without departing from the technical spirit of the disclosed embodiments. The technical scope of the embodiments of this disclosure is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A method for preparing a high-efficiency broadband infrared absorption coating, characterized in that, Includes the following steps: Step S1 involves pre-treating the thermoelectric ceramic substrate by grinding and polishing. Step S2 involves using a combination of physical dispersion and chemical dispersion with a dispersant to uniformly disperse micro / nano carbon, TiN and Si3N4 nanoparticles, dispersant, diluent and binder, and prepare a spraying slurry. Step S3: The prepared spray slurry is uniformly sprayed onto the pretreated thermoelectric ceramic substrate surface using an electrostatic spraying method. After curing, a broadband absorption coating is obtained.

2. The method for preparing a high-efficiency broadband infrared absorption coating as described in claim 1, characterized in that, The percentage content of the spray slurry composition is as follows: micro / nano carbon: 30%–50%; TiN nanoparticles: 20%–30%; Si3N4 nanoparticles: 20%–30%; dispersant: 5%–10%; diluent: 5%–10%; binder: 10%–20%.

3. The method for preparing a high-efficiency broadband infrared absorption coating as described in claim 1, characterized in that, The micro / nano carbon particles have a diameter of 0.1–1 μm, and the TiN and Si3N4 nanoparticles have a diameter of 10–100 nm.

4. The method for preparing a high-efficiency broadband infrared absorption coating as described in claim 1, characterized in that, The physical dispersion methods are ultrasonic dispersion or mechanical stirring dispersion.

5. The method for preparing a high-efficiency broadband infrared absorption coating as described in claim 1, characterized in that, The physical dispersion time of the micro / nano carbon, TiN, and Si3N4 nanoparticles is 30–120 minutes.

6. The method for preparing a high-efficiency broadband infrared absorption coating as described in claim 1, characterized in that, The dispersant is a polycarboxylate dispersant, a polyether-modified polysiloxane dispersant, or an organosilicon dispersant, and the amount of dispersant added is 5%–20% of the amount of micro / nano carbon added.

7. The method for preparing a high-efficiency broadband infrared absorption coating as described in claim 1, characterized in that, The diluent is dodecyl glycidyl ether, and the binder is polyvinyl alcohol or epoxy resin.

8. The method for preparing a high-efficiency broadband infrared absorption coating as described in claim 1, characterized in that, The spraying voltage is 30–40kV, the spraying distance is 15–25cm, the spraying speed is 10–15cm / s, and the thickness of the absorbent coating is 20–200μm.

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