阅读说明：本技术 一种高导热型近红外电磁屏蔽膜 (High-heat-conduction near-infrared electromagnetic shielding film ) 是由 罗良林 江宗发 罗斌 于 2019-11-28 设计创作，主要内容包括：本发明公开了一种高导热型近红外电磁屏蔽膜,包含如下步骤：(1)将铜箔置于反应炉的底部,向炉内持续通入甲烷、氩气和氢气,炉内温度升至1000±20℃范围内,温度到达300℃后不断向炉内喷雾氯化铜溶液；(2)反应后将铜箔取出；(3)将聚甲基丙烯酸甲酯涂覆在铜箔上的沉积物表面,150±5℃下加热,空冷,浸泡在40～50℃的硝酸铁、柠檬酸的水溶液中,水浴恒温超声,然后将铜箔取出,获得液相；(4)向液相中加入氯铱酸的乙醇溶液,在基板表面旋涂混合液,烘干,氮气氛围下450～500℃,空冷,称重；重复旋涂、烘干和加热工序,直到基板增重2%～5%为止,基板表面即生成近红外电磁屏蔽膜。本发明方法制备的屏蔽膜在近红外波段具有良好的屏蔽效果。(The invention discloses a high-heat-conductivity near-infrared electromagnetic shielding film, which comprises the following steps: (1) placing the copper foil at the bottom of a reaction furnace, continuously introducing methane, argon and hydrogen into the furnace, raising the temperature in the furnace to be within the range of 1000 +/-20 ℃, and continuously spraying a copper chloride solution into the furnace after the temperature reaches 300 ℃; (2) taking out the copper foil after reaction; (3) coating polymethyl methacrylate on the surface of a deposit on a copper foil, heating at 150 +/-5 ℃, air-cooling, soaking in an aqueous solution of ferric nitrate and citric acid at 40-50 ℃, carrying out constant-temperature ultrasonic treatment in a water bath, and then taking out the copper foil to obtain a liquid phase; (4) adding an ethanol solution of chloroiridic acid into the liquid phase, spin-coating the mixed solution on the surface of the substrate, drying, cooling in air at 450-500 ℃ in a nitrogen atmosphere, and weighing; repeating the processes of spin coating, drying and heating until the weight of the substrate is increased by 2-5%, and generating the near-infrared electromagnetic shielding film on the surface of the substrate. The shielding film prepared by the method has good shielding effect in the near infrared band.)

1. A high heat conduction type near infrared electromagnetic shielding film is characterized by comprising the following steps:

(1) preparing a copper chloride solution, wiping the surface of a copper foil with acetone, cleaning and drying the copper foil to be used as a collecting plate, placing the collecting plate at the bottom of a reaction furnace, continuously introducing methane, argon and hydrogen into the furnace, discharging air in the furnace, raising the temperature in the furnace to be within the range of 1000 +/-20 ℃ after the air is discharged, and continuously spraying the copper chloride solution into the furnace after the temperature reaches 300 ℃;

(2) after the reaction is carried out for 30-50 min at the temperature of 1000 +/-20 ℃, stopping spraying, stopping heating, closing methane and hydrogen, continuously introducing argon to cool the temperature in the hearth to the normal temperature, finally stopping introducing argon, and taking out the copper foil;

(3) coating polymethyl methacrylate on the surface of a deposit on a copper foil, heating the copper foil at 150 +/-5 ℃, cooling the copper foil to normal temperature after heating, soaking the copper foil in an aqueous solution of ferric nitrate and citric acid at 40-50 ℃, carrying out water bath constant-temperature ultrasonic treatment for 10-20 min, and taking out the copper foil to obtain a liquid phase;

(4) adding an ethanol solution of chloroiridic acid into the liquid phase to prepare a mixed solution, taking a clean substrate, spin-coating the mixed solution on the surface of the substrate, drying the substrate, heating to 450-500 ℃ under the nitrogen atmosphere, taking out, air-cooling to normal temperature, and weighing; and then spin-coating the mixed solution again, drying, heating to 450-500 ℃ in a nitrogen atmosphere, repeating the spin-coating, drying and heating processes until the weight of the final weighing is increased by 2% -5% compared with the weight of the clean substrate before spin-coating, and generating the high-thermal-conductivity near-infrared electromagnetic shielding film on the surface of the substrate.

2. The high thermal conductivity near-infrared electromagnetic shielding film according to claim 1, wherein the high thermal conductivity near-infrared electromagnetic shielding film is subjected to post-processing, and the post-processing comprises:

1) placing the substrate attached with the high-heat-conductivity near-infrared electromagnetic shielding film on a cathode disc of a glow furnace, wherein the high-heat-conductivity near-infrared electromagnetic shielding film faces upwards; covering the substrate with a copper mesh, the copper mesh being in electrical contact with the cathode disk; closing the glow furnace, vacuumizing the glow furnace to 10-20 Pa, filling hydrogen into the glow furnace to 100-200 Pa, setting the glow starting voltage to 680V, adjusting the duty ratio to 6-15, starting glow starting and heating to prevent the copper mesh from arcing, and if the copper mesh arcs, reducing the duty ratio;

2) when the temperature in the furnace rises to 150 ℃, argon gas is started to be filled into the furnace, the voltage is adjusted to 710V, and the volume ratio of the flow of the hydrogen gas to the flow of the argon gas flowing into the furnace is H₂Ar =10: 0.5-0.9, adjusting a vacuum pump to keep the pressure in the furnace at 200 +/-20 Pa, further increasing the duty ratio to raise the temperature to 250 ℃ under the condition of no arc striking in the furnace, keeping the temperature at 250 +/-5 ℃ for 10-15 h, closing the duty ratio, voltage, the vacuum pump, argon and hydrogen in sequence after the heat preservation is finished to cool the substrate in the furnace to normal temperature along with the furnace, starting the vacuum pump to pump residual gas in the furnace to 10-20 Pa, then closing the vacuum pump, opening an air valve to enable air to enter the furnace to balance the internal and external air pressures, opening a glow furnace, and taking out the substrate to obtain the post-processed high-heat-conduction near-infrared electromagnetic shielding film.

3. The near-infrared electromagnetic shielding film with high thermal conductivity according to claim 2, wherein in the step (1), the concentration of copper chloride in the copper chloride solution is 20-30 g/L, and the balance is water; the flow rate of introducing argon is 50-100 mL/min, the flow rate of introducing hydrogen is 200-250 mL/min, the flow rate of introducing methane is 1-2 mL/min, and the spray amount of the copper chloride solution is 10 mL/min.

4. The near-infrared electromagnetic shielding film with high thermal conductivity of claim 2, wherein the copper foil is heated at 150 ± 5 ℃ for 10-15 min; the concentration of each component in the aqueous solution of the ferric nitrate and the citric acid is as follows: 50-80 g/L of ferric nitrate, 10-30 g/L of citric acid and the balance of water.

5. The near-infrared electromagnetic shielding film with high thermal conductivity as claimed in claim 2, wherein in the step (4), the mass percentage of the chloroiridic acid in the ethanol solution of chloroiridic acid is 10% to 15%, and the heating time at 450 to 500 ℃ is 20 to 30 min.

Technical Field

The invention belongs to the technical field of electromagnetic shielding, and particularly relates to a high-heat-conductivity near-infrared electromagnetic shielding film.

Background

In recent years, with the great increase of the application demand of electromagnetic waves, people have been deeply researching electromagnetic waves, and the application band of the electromagnetic waves is developed more and more. In order to meet the requirements of long-distance transmission and detection, the emission power of electromagnetic waves of radar, satellite communication and other equipment is gradually increased, and the intensity of the electromagnetic waves is greatly improved, particularly in a wide band from radio waves to microwaves. At present, electromagnetic waves are generally applied to various fields such as medical care, television broadcasting, mobile communication, optics and the like, so that a lot of convenience is provided for life, but excessive application of electromagnetic waves causes electromagnetic pollution to a certain extent, so that the electromagnetic environment of a space background is gradually complicated, and various fields begin to put forward requirements on electromagnetic interference resistance. In order to solve the electromagnetic shielding problem, novel electromagnetic shielding materials are continuously emerging, and novel electromagnetic shielding means are continuously applied. Generally, a near-infrared electromagnetic shielding film refers to a type of optical thin film that has a certain optical transmittance in the visible light band and the near-infrared optical band and can effectively shield other interfering electromagnetic waves outside the band. The indium tin oxide transparent conductive film is an electromagnetic shielding film which is widely used at present, has certain electromagnetic shielding capability on electromagnetic waves in a wide waveband range, and has good light transmission characteristic in a visible light waveband. However, the ITO thin film cannot shield electromagnetic waves in the near infrared range well due to its poor attenuation of electromagnetic waves. The technology for efficiently shielding electromagnetic waves in the near infrared band is still an urgent technical problem to be solved in the electromagnetic shielding technology in the current stage.

Disclosure of Invention

In order to solve the technical problem, the invention provides a high-thermal-conductivity near-infrared electromagnetic shielding film, which comprises the following steps:

(1) preparing a copper chloride solution, wiping the surface of a copper foil with acetone, cleaning and drying the copper foil to be used as a collecting plate, placing the collecting plate at the bottom of a reaction furnace, continuously introducing methane, argon and hydrogen into the furnace, discharging air in the furnace, raising the temperature in the furnace to be within the range of 1000 +/-20 ℃ after the air is discharged, and continuously spraying the copper chloride solution into the furnace after the temperature reaches 300 ℃;

(2) after the reaction is carried out for 30-50 min at the temperature of 1000 +/-20 ℃, stopping spraying, stopping heating, closing methane and hydrogen, continuously introducing argon to cool the temperature in the hearth to the normal temperature, finally stopping introducing argon, and taking out the copper foil;

(3) coating polymethyl methacrylate on the surface of a deposit on a copper foil, heating the copper foil at 150 +/-5 ℃, cooling the copper foil to normal temperature after heating, soaking the copper foil in an aqueous solution of ferric nitrate and citric acid at 40-50 ℃, carrying out water bath constant-temperature ultrasonic treatment for 10-20 min, and taking out the copper foil to obtain a liquid phase;

(4) adding an ethanol solution of chloroiridic acid into the liquid phase to prepare a mixed solution, taking a clean substrate, spin-coating the mixed solution on the surface of the substrate, drying the substrate, heating to 450-500 ℃ under the nitrogen atmosphere, taking out, air-cooling to normal temperature, and weighing; and then spin-coating the mixed solution again, drying, heating to 450-500 ℃ in a nitrogen atmosphere, repeating the spin-coating, drying and heating processes until the weight of the final weighing is increased by 2% -5% compared with the weight of the clean substrate before spin-coating, and generating the high-thermal-conductivity near-infrared electromagnetic shielding film on the surface of the substrate.

Further, the high-thermal-conductivity near-infrared electromagnetic shielding film is subjected to post-treatment, and the post-treatment comprises the following steps:

1) placing the substrate attached with the high-heat-conductivity near-infrared electromagnetic shielding film on a cathode disc of a glow furnace, wherein the high-heat-conductivity near-infrared electromagnetic shielding film faces upwards; covering the substrate with a copper mesh, the copper mesh being in electrical contact with the cathode disk; closing the glow furnace, vacuumizing the glow furnace to 10-20 Pa, filling hydrogen into the glow furnace to 100-200 Pa, setting the glow starting voltage to 680V, adjusting the duty ratio to 6-15, starting glow starting and heating to prevent the copper mesh from arcing, and if the copper mesh arcs, reducing the duty ratio;

2) when the temperature in the furnace rises to 150 ℃, argon gas is started to be filled into the furnace, the voltage is adjusted to 710V, and the volume ratio of the flow of the hydrogen gas to the flow of the argon gas flowing into the furnace is H₂Ar =10: 0.5-0.9, adjusting the vacuum pump to keep the pressure in the furnace at 200 +/-20 Pa, and further increasing the duty ratio to prevent the furnace from being ignitedAnd (3) heating to 250 ℃ under the arc condition, keeping the temperature at 250 +/-5 ℃ for 10-15 h, closing duty ratio, voltage, a vacuum pump, argon and hydrogen in sequence after the heat preservation is finished, cooling the substrate in the furnace to normal temperature along with the furnace, starting the vacuum pump to pump residual gas in the furnace into the furnace to 10-20 Pa, closing the vacuum pump, opening an air valve to enable air to enter the furnace to balance the internal and external air pressure, opening a glow furnace, and taking out the substrate to obtain the post-processed high-heat-conductivity near-infrared electromagnetic shielding film.

Further, in the step (1), the concentration of copper chloride in the copper chloride solution is 20-30 g/L, and the balance is water; the flow rate of introducing argon is 50-100 mL/min, the flow rate of introducing hydrogen is 200-250 mL/min, the flow rate of introducing methane is 1-2 mL/min, and the spray amount of the copper chloride solution is 10 mL/min.

Further, heating the copper foil at 150 +/-5 ℃ for 10-15 min; the concentration of each component in the aqueous solution of the ferric nitrate and the citric acid is as follows: 50-80 g/L of ferric nitrate, 10-30 g/L of citric acid and the balance of water.

Further, in the step (4), the mass percentage of the chloroiridic acid in the ethanol solution of chloroiridic acid is 10-15%, and the heating time at 450-500 ℃ is 20-30 min.

Therefore, the beneficial effects of the invention are as follows:

1) the shielding film prepared by the method has good shielding effect in the near infrared band, shows that the passing rate of electromagnetic waves in the near infrared band is low, and particularly has the best shielding effect on the electromagnetic waves in the 1100-1600 nm band;

2) the invention designs a post-treatment optimization procedure aiming at the prepared near-infrared electromagnetic shielding film, and after the shielding film prepared by the method is subjected to the post-treatment procedure, the near-infrared shielding effect is obviously improved, and the technical reference is provided for preparing a high-performance shielding coating.

Drawings

Fig. 1 is a graph showing the transmittance of the electro-magnetic shielding films prepared in each example and comparative example in the near infrared electromagnetic wave band.

Detailed Description

The following is a detailed description with reference to examples: