TW201600573A - Composite coating for cooling and manufacturing method thereof - Google Patents

Abstract

The present invention provides a composite coating for cooling and a manufacturing method thereof, especially a coating used on an outdoor casing, comprising a radiation cooling layer and a reflective thermal insulating layer having a plurality of open radiation cavities. The reflective thermal insulating layer is formed on top of the radiation cooling layer and has heat reflecting effects for visible light and near infrared light. The radiation cooling layer radiates the heat accumulated in the casing outwardly as infrared radiation through the open radiation cavities. Further, taking the advantage of the temperature difference between inside and outside of the open radiation cavities, natural convection of air is formed to dissipate the heat. Therefore, the present invention provides triple composite cooling functions of thermal reflection, thermal radiation and thermal convection to reduce heat load of the outdoor casing.

Description

Composite cooling coating and manufacturing method thereof

The invention relates to a composite cooling coating, in particular to a composite cooling coating which simultaneously has the triple composite cooling function of heat reflection, heat radiation and heat convection, and a manufacturing method thereof.

The external enclosure is affected by the heat electronic components inside the enclosure and the sunshine of the environment. As a result, the heat generated inside the enclosure is large. If it cannot be dissipated immediately, it will accelerate the aging damage of the electronic components, resulting in failure and failure of the operation of the chassis equipment. In addition, there is a strong summer sunshine in Taiwan. Even if a cooling fan is installed inside the outdoor cabinet, the temperature inside the chassis often exceeds 50 °C. Therefore, the industry needs a method that can effectively reduce the thermal load of the outdoor chassis.

Insulation coatings have the advantages of obvious heat insulation effect and convenient use. They can be widely used in construction, agricultural storage, petrochemical storage tanks and transportation vehicles. The general thermal insulation coating can be divided into reflective partitions according to the mechanism of heat insulation. Thermal coatings, radiant heat-insulating coatings and barrier-type thermal insulation coatings, and the solar radiation spectrum can be mainly divided into three parts: (1) ultraviolet region with a wavelength of 0.2-0.4 μm , accounting for 5% of solar radiation energy; b) The visible light region has a wavelength of 0.4 to 0.72 μm , which accounts for 45% of the solar radiation energy; and (3) the near-infrared region has a wavelength of 0.72 to 2.5 μm , which accounts for 50% of the solar radiation energy.

Reflective thermal insulation coatings use a high reflectivity of special pigments and functional fillers to reflect large amounts of sunlight in the visible and near-infrared regions, and reduce the temperature of the coated objects by reducing the absorption of solar radiation energy.

The atmospheric environment has a high transparency in the wavelength range of 8~13.5 μm , which is called “atmospheric window”. The heat radiation of objects on the ground can directly pass through the atmospheric window to achieve the effect of radiating heat. The radiation type thermal insulation coating is a kind A coating capable of accumulating and dispersing an object by infrared radiation in the above-mentioned wavelength range by a plurality of metal oxide pigments having a high emissivity.

Barrier-type heat-insulating coatings are ones that achieve thermal insulation by the high thermal resistance of the coating itself. Usually, low-density, high-porosity and low-water-cement aggregates are added to the binder. The thickness of the coating generally needs 5~ 20mm is fully dried and solidified to block heat transfer.

Each of the above three types of heat-insulating coatings has its own advantages and disadvantages and application limitations. For an outdoor-type chassis with built-in electronic active components, it is necessary to immediately distribute the accumulated heat generated by the active components inside the chassis, so it is not suitable for the use of barrier-type heat insulation that blocks heat transfer. Paints, substrates, and reflective heat-insulating coatings can block solar heat energy by reflecting function, but lack sufficient infrared radiation heat dissipation capability, and can not effectively solve the problem of heat storage inside the chassis. In addition, radiation-type heat insulation coatings can The heat storage of the chassis is distributed. However, according to Kirchhoff's law of radiation, the greater the radiation capacity of the material at a certain temperature, the greater its absorption capacity. Therefore, in the outdoor environment with strong sunlight, the radiation type is separated. The far-infrared heat dissipation and near-infrared endothermic reaction of the thermal paint will be produced at the same time, thus reducing the near-infrared heat reflection effect. Similarly, the general composite heat-insulating coating is mixed with the heat-reflecting substance and the infrared radiation emissivity in the same paint. Higher substance, although it can simultaneously produce reflective heat insulation and radiation cooling function, On the one hand it will cause a decline in the near infrared reflectance affect the overall cooling effect coatings.

It can be seen that there are still many shortcomings in the various thermal insulation coating technologies mentioned above, which are not a good designer, and need to be improved. In view of this, the industry needs a coating that can fully utilize various heat dissipation mechanisms. The present invention is directed to the above needs and actively studies Improvement and innovation, finally break through the traditional old thermal insulation coating structure, research and development of this composite cooling coating and its production methods.

The main object of the present invention is to provide a composite cooling coating which has excellent heat reflection performance, heat conduction and heat radiation performance, and which can exhibit a good cooling effect, and a production method thereof.

A secondary object of the present invention is to provide a composite cooling coating having a triple cooling function of heat reflection, heat radiation and heat convection, and a manufacturing method thereof.

Another object of the present invention is to provide a composite cooling coating capable of blocking the heat transfer from the outside sunlight to the inside of the chassis, and dissipating the heat storage inside the chassis, thereby effectively reducing the internal and external double thermal loads of the outdoor enclosure and the manufacturing method thereof. .

The composite cooling coating of the present invention and a manufacturing method thereof, comprising a radiant cooling layer and a reflective heat insulating layer, wherein the reflective heat insulating layer is formed above the radiant cooling layer, and the reflective heat insulating layer is provided with plural An open radiant cavity is used to generate a triple composite cooling function of heat reflection, heat radiation and heat convection.

Wherein the composition of the radiant cooling layer comprises an infrared radiator, which comprises between 50% and 60% by weight of the total composition of the radiant cooling layer; and a piece of filler which occupies 5% by weight of the total composition of the radiant cooling layer. And 15% by weight; and a polymer binder, which is between 25 wt% and 45 wt% of the total composition of the radiant cooling layer; the infrared radiator is selected from the group consisting of carbides, nitrides or a composition thereof, and the thermal conductivity is at least greater than 100W/mk, the infrared radiance of the atmospheric window wavelength range of 8~13.5μm is at least greater than 93%; the sheet filler is selected from the sheet carbon material, the thermal conductivity is at least greater than 100W/mk, and it is at 8 The infrared radiance in the wavelength range of ~13.5μm atmospheric window is at least greater than 90%, in the radiant cooling layer, the polymer binder connects the infrared radiator with high thermal conductivity and the sheet filler to form a coherent heat conduction and radiation network, thereby rapidly transmitting and dissipating heat. Achieve excellent radiation cooling.

The composition of the reflective heat insulation layer comprises a solid filler which accounts for between 30% and 60% by weight of the total composition of the reflective heat insulating layer; and a resin which accounts for 40% by weight of the total composition of the reflective heat insulating layer. 70 wt%; the solid filler comprises a plurality of reflective powders and a plurality of nano metal sheets, wherein in the reflective heat insulating layer, the nano metal sheets have a larger aspect ratio than the general metal powders, It can be suspended horizontally in the resin to produce a good specular reflection effect. When the sunlight illuminates the reflective heat insulation layer, the direct reflection and multiple reflections generated by the reflective powder and the nano metal sheet can enhance the reflective heat insulation layer. The reflectance is at least greater than 95%.

The composite cooling coating of the present invention is provided with a plurality of open radiation chambers for the purpose of achieving heat radiation and heat convection, and the opening radiation chamber has an aperture ratio of 10% to 40%. When less than 10% will hinder the amount of heat radiation and reduce the cooling efficiency. Conversely, when it is more than 40%, the amount of heat reflection will be reduced and excessive visible light and near-infrared light will be absorbed to reduce the cooling efficiency. The aperture is preferably 10mm to 30mm, and less than 10mm will reduce the heat convection efficiency. Conversely, if it is greater than 30mm, the thermal convection efficiency will also be reduced.

10‧‧‧Substrate

100‧‧‧Composite cooling coating

120‧‧‧radiation cooling layer

122‧‧‧Infrared radiator

124‧‧‧Flake filling

126‧‧‧ Polymer Adhesive

140‧‧‧Reflective insulation

142‧‧‧Reflecting powder

144‧‧‧Nano metal sheet

146‧‧‧Resin

160‧‧‧Opening cavity

A‧‧‧Heat reflex pathway

B‧‧‧thermal radiation pathway

C‧‧‧thermal convection

D‧‧‧heat storage

1 is a schematic view of a composite cooling coating of the present invention; FIG. 2 is an enlarged schematic view of a radiation cooling layer of the present invention; FIG. 3 is an enlarged schematic view of a reflective heat insulating layer of the present invention; and FIG. 4 is a reflective insulating layer of the present invention; Figure 3 is a perspective view showing the temperature and sunshine time in a sunshine test according to a comparative example and an embodiment of the present invention. Diagram.

Referring to FIG. 1 , the composite cooling coating 100 of the present invention is applied to a substrate 10 which is a metal, a non-metal or a mixture thereof (for example, a metal plate, a concrete wall or a cement floor). The composite cooling coating 100 comprises a radiant cooling layer 120, a reflective insulating layer 140 and an open radiant cavity 160. The reflective insulating layer 140 is formed above the radiant cooling layer 120 and disposed on the reflective insulating layer 140. There is a plurality of open radiant cavities 160. The composite cooling coating 100 can block most of the solar radiation from being absorbed by the substrate 10 by reflecting the heat reflection path A of the heat insulating layer 140. In addition, the composite cooling coating 100 The heat storage path D on the substrate 10 can be dissipated through the thermal radiation path B of the opening radiant cavity 160. Further, due to the temperature difference between the radiant cooling layer 120 and the reflective insulating layer 140, the open radiant cavity 160 can be via the thermal convection path C. The heat dissipation effect of the radiant cooling layer 120 is assisted, and the substrate 10 is accelerated to be cooled.

Referring to FIG. 2, the radiant cooling layer 120 has a plurality of infrared radiators 122, a plurality of sheet fillers 124, and a polymer binder 126. Although the shape of the infrared radiator 122 in FIG. 2 is a sphere, However, it can also be an irregular shape and is not limited to a sphere.

In a preferred embodiment, the infrared radiator 122 is preferably a nano-sized powder, and may be a nano-powder such as tantalum carbide (SiC) or aluminum nitride (AlN), or a combination thereof, and 55wt% of the total composition of the radiant cooling layer 120, the thermal conductivity of the infrared radiator 122 is at least greater than 100W/mk, and the infrared radiance in the atmospheric window wavelength range of 8~13.5μm is at least greater than 93%, by infrared The nano-crystallization of the radiator 122 can effectively improve the radiation heat dissipation function of the radiant cooling layer 120.

As is well known to those skilled in the art, the thermal conductivity of general polymer materials is less than 0.5 W/mk. If metal powder is added as a heat conductive filler, the thermal conductivity coefficient can be increased to more than 10 W/mk. However, general metal powder The infrared radiance of the bulk filler is often less than 75%, which inevitably reduces the infrared radiation performance of the polymer material. For this reason, the composite cooling coating system of the present invention utilizes a sheet having high thermal conductivity and high radiation. The carbon material is used as the sheet filler 124 to enhance the performance of the radiant cooling layer 120. In a preferred embodiment, the sheet filler 124 is preferably, for example, a sheet of bamboo carbon powder, a flake graphite powder or a combination thereof. , which accounts for 10% by weight of the total composition of the radiant cooling layer 120, and has a thermal conductivity of at least 100 W/mk, and has a particle diameter of 10 to 20 μm , and a thickness of 0.1 to 0.2 μm . The material 124 can increase the contact area with the polymer binder 126, and in the same filling state, it is easier to contact each other than the particulate filler to form a continuous heat conduction network, so that the radiant cooling layer 120 can be effectively improved. Save D transmits the heat transfer capability to the outside. In addition, the above-mentioned sheet filler 124 has an infrared radiance of at least 90% in the atmospheric window wavelength range of 8 to 13.5 μm, so that the radiant cooling layer 120 has good heat conduction and heat radiation functions at the same time. .

In a preferred embodiment, the polymer binder 126 is preferably an epoxy resin, a polyester resin or a rubber, and has an infrared radiance of at least 94% in an atmospheric window wavelength range of 8 to 13.5 μm. The infrared radiator 122 and the sheet filler 124 can be coupled to each other to form a continuous heat conduction and radiation network, so that the radiation cooling layer 120 achieves the dual effects of rapidly transferring heat and radiating heat.

Referring to FIG. 3, the reflective heat insulating layer 140 has a plurality of reflective powders 142, a plurality of nano metal sheets 144, and a resin 146. The reflective powder 142 is selected from a substance having a higher refractive index by increasing reflection. The difference in refractive index between the powder 142 and the resin 146 can effectively improve the reflection ability of the reflective heat insulating layer 140 for incident light, and the nano metal sheet 144 is selected from a sheet metal of a nanometer size. Powder, due to its light weight and thin thickness, has a large aspect ratio, can be suspended horizontally in the resin to avoid the phenomenon of oblique suspension, vertical distribution or sinking, which is not conducive to light reflection, thus producing high-efficiency specular reflection. The direct reflection and the multiple reflection jointly produced by the reflective powder 142 and the nano metal sheet 144, and the reflectance of the reflective heat insulating layer 140 can be improved by utilizing the refractive index difference of the material and the specular reflection. At least greater than 95%.

Although the shape of the reflective powder 142 in FIG. 3 is shown as a solid sphere, it may be a hollow structure or other shaped particles, and is not limited to a solid sphere. The reflective powder 142 may be titanium dioxide, mica, or In a preferred embodiment, the reflective powder 142 is preferably rutile type titanium dioxide (TiO ₂ ) particles, and has a refractive index of about 2.75, and the reflection heat insulation The layer 140 has a total composition of 35 wt%.

The above-mentioned nano metal sheet 144 may be selected from the group consisting of aluminum, zinc, copper, nickel, cobalt, chromium, iron or a combination thereof. In a preferred embodiment, the above-mentioned nano metal sheet 144 is preferably, for example, a sheet of aluminum. The powder has a particle diameter of 100 to 300 nm and a thickness of 20 to 40 nm, and it accounts for 15% by weight of the total composition of the reflective heat insulating layer 140.

Referring to FIG. 4, the reflective heat insulating layer 140 is provided with a plurality of open radiating cavities 160 for radiating heat of the lower radiant cooling layer 120 on the one hand, and using the reflective insulating layer 140 and radiation on the other hand. The difference in temperature between the cooling layers 120 causes natural convection of the air in the radiation chamber to enhance the heat dissipation effect of the composite cooling coating.

When the aperture of the opening radiant cavity 160 is too small, the air in the radiant cavity is confined to a small area, and natural convection is not easily generated. Conversely, when the aperture of the radiant cavity 160 is too large, the reflective insulating layer 140 and the radiant cooling are reduced. The temperature difference between the layers 120 is also unfavorable for natural convection. Although the shape of the open radiant cavity 160 of Fig. 4 is shown as a square, it may also be a circle. Shape or other shape, in a preferred embodiment, the aperture of the open cavity 160 is preferably, for example, a square or circular shape of 15 to 25 mm.

When the aperture ratio of the open radiant cavity 160 is too low, the ability of the radiant cooling layer 120 to radiate heat to the outside is reduced. Conversely, when the aperture ratio of the open radiant cavity 160 is too high, the reflective insulating layer 140 is reduced. The amount of sunlight reflected, in a preferred embodiment, the aperture ratio of the open cavity 160 is preferably, for example, 25 to 35%.

The features of the present invention will become more apparent to those skilled in the art of the present invention. .

Example 1: Production of composite cooling coating

In Fig. 1, a substrate 10 is provided, first, 55 wt% (based on the total weight of the radiant cooling coating) of cerium carbide (SiC) nanopowder, 10 wt% of flaky bamboo carbon powder and 35 wt% The epoxy resin is placed in a container and mixed for about 30 minutes to prepare a radiant cooling coating. Then, the radiant cooling coating prepared above is sprayed under high pressure on the substrate to form a thickness of 0.15 to 0.2. The radiant cooling layer 120 between mm.

Next, 35 wt% (based on the total weight of the reflective heat insulating coating) of rutile type titanium dioxide powder, 15 wt% of nano-flaky aluminum powder and 50 wt% of aqueous acrylic resin (Acrylic resin) were placed in one In the container, mixing and stirring is carried out for about 40 minutes to prepare a reflective heat insulating coating. After the radiation cooling layer 120 has reached the level of dryness, the reflective heat insulating coating prepared above is applied to the radiation by brushing or spraying. Above the cooling layer 120, to form a reflective thermal insulation layer 140 having a thickness of between 0.2 and 0.25 mm, the brushing operation of the reflective thermal insulation coating can be performed by vertical staggered brushing, for example, parallel adjacent The distance between the two paints remains 20mm, it is possible to form a square opening radiation cavity with a hole diameter of 20mm. By adjusting the ratio between the total area of the radiation cavity and the brushing area of the reflective heat insulation layer, the aperture ratio can be controlled, and the opening radiation cavity of this embodiment can be controlled. 160 is a square having a hole diameter of 20 mm, and its opening ratio is 30%.

In addition, the reflective heat insulating layer 140 may also be formed by high pressure spraying. For example, a plurality of square masks having a side length of 20 mm are first disposed on the surface of the radiant cooling layer 120, and the reflective heat insulating coating is sprayed on the surface. Above the radiant cooling layer 120, the square mask is removed to form a reflective insulating layer having a plurality of square open radiating cavities having a diameter of 20 mm, in combination with the reflective insulating layer 140 and the radiant cooling layer 120. That is, the composite cooling coating 100 of the present invention is formed.

In the above composite cooling coating, the upper reflective heat insulation layer has high reflectivity for sunlight, and can prevent solar heat from entering the substrate, and the bottom radiant cooling layer has high radiation heat dissipation capability, allowing the heat storage to be efficiently radiated. The effect of cooling the substrate, together with the natural convection of the air generated by the open radiant cavity, combines the reflective insulating layer with the radiant cooling layer to achieve an excellent cooling effect.

Example 2: Sunlight test of composite cooling coating

Two sealed stainless steel cabinets were used as test chambers, and were placed outdoors for sunshine test. One of the test chambers was not subjected to any coating treatment, which was Comparative Example 1; the other test chamber was Example 2 and was on the surface of the cabinet. The composite cooling coating of the present invention is prepared, and the composite cooling coating is produced in the same manner as in the first embodiment. Here, the width, height and depth of the casing of the test box are 400 mm and 469 mm, respectively. 300mm, and a 20W cement resistor is placed inside the test chamber as a heat source to simulate the heat storage generated by the continuous operation of the heating elements inside the chassis.

The above Comparative Example 1 and Example 2 were placed in the outdoor environment to receive sunlight, and the heat source inside the test chamber was started, and then the ambient temperature and the internal temperature of the test chamber were recorded. The results of the recording are shown in Fig. 5, and the results showed that The maximum temperatures of Comparative Example 1, Example 2 and the environment were 55 ° C, 40.7 ° C and 37.7 ° C, respectively. It can be seen that the test chamber with composite cooling coating is the highest of the two compared with the test chamber without composite cooling coating. The temperature difference reached 14.3 ° C. It can be clearly seen from the results that the composite cooling coating of the invention has a good cooling effect, and the internal temperature of the test chamber can be kept close to the environment under the double heat load conditions of receiving sunlight and heat storage in the tank. Temperature, the maximum temperature difference between the two is only 3 °C.

The composite cooling coating provided by the invention has the following advantages when compared with other conventional techniques:

1. The reflective heat insulating layer of the present invention has excellent heat reflecting properties.

2. The radiant cooling layer of the present invention has excellent heat conduction and heat radiation properties and can exert a good cooling effect.

3. The reflective heat insulating layer of the present invention is provided with a plurality of open radiating cavities, which enable the present invention to simultaneously have a triple cooling function of heat reflection, heat radiation and heat convection.

4. The invention not only can block the heat transfer of the outside sunlight to the inside of the chassis, but also can dissipate the heat storage inside the chassis to achieve the cooling effect, and can effectively reduce the internal and external double heat load of the outdoor type chassis.

The detailed description above is intended to be illustrative of a possible embodiment of the present invention, and is not intended to limit the scope of the present invention. Any equivalent implementations or modifications that are not departing from the spirit of the present invention should be included in The patent scope of this case.

10‧‧‧Substrate

100‧‧‧Composite cooling coating

120‧‧‧radiation cooling layer

140‧‧‧Reflective insulation

160‧‧‧Opening cavity

Claims (26)

A composite cooling coating, which mainly comprises: a radiant cooling layer coated on a substrate, the radiant cooling layer comprising between 50% and 60% by weight of the total composition of the radiant cooling layer An infrared radiator, a sheet filler between 5 wt% and 15 wt% of the total composition of the radiant cooling layer, and a polymer binder between 25 wt% and 45 wt% of the total composition of the radiant cooling layer; A reflective insulating layer is formed on the radiant cooling layer, and the reflective insulating layer is provided with a plurality of open radiant cavities. The composite cooling coating according to claim 1, wherein the reflective heat insulating layer comprises a solid filler and a resin, and the solid filler accounts for 30% by weight to 60% by weight of the total composition of the reflective heat insulating layer. Between 40% and 70% by weight of the total composition of the reflective insulating layer. The composite cooling coating of claim 1, wherein the infrared radiator is a carbide, a nitride or a composition thereof. The composite cooling coating according to claim 1, wherein the sheet filler is flaky bamboo carbon powder, flake graphite powder or a combination thereof. The composite cooling coating of claim 2, wherein the solid filler is composed of a mixture of a plurality of reflective powders and a plurality of nanosheets. The composite temperature-lowering coating according to claim 5, wherein the reflective powder is titanium dioxide, mica, ceria, calcium carbonate or a combination thereof. The composite cooling coating of claim 5, wherein the nanosheet is a sheet of aluminum, zinc, copper, nickel, cobalt, chromium, iron or a combination thereof. The composite cooling coating according to claim 1, wherein the nano metal piece is between 10 nm and 500 nm. between. The composite cooling coating of claim 1, wherein the openings of the open cavity are square or circular in shape. The composite cooling coating according to claim 1, wherein the apertures of the open-radiation cavities are between 1 mm and 100 mm. The composite cooling coating according to claim 1, wherein the aperture ratio of the open cavity is between 1% and 50%. A composite cooling coating manufacturing method comprises the following steps: Step 1: mixing an infrared radiator, a sheet filler and a polymer adhesive to form a radiation cooling coating; and step 2, coating the radiation cooling coating on a substrate. a step of forming a radiant cooling layer; mixing the solid filler with the resin to form a reflective heat insulating coating; and step 4, applying a reflective heat insulating coating to the radiant cooling layer to form a reflective insulating layer. And a plurality of open radiant cavities are disposed on the reflective insulating layer. The composite cooling coating manufacturing method according to claim 12, wherein the infrared radiator is a carbide, a nitride or a composition thereof. The composite temperature-lowering coating manufacturing method according to claim 12, wherein the sheet-shaped filler is a flaky bamboo carbon powder, a flake graphite powder or a combination thereof. The composite cooling coating manufacturing method according to claim 12, wherein the solid filler accounts for 30% by weight to 60% by weight of the total composition of the reflective heat insulating coating, and the resin accounts for 40% by weight of the total composition of the reflective heat insulating coating. Between 70wt%. The composite cooling coating manufacturing method according to claim 14, wherein the solid filler is plural A mixture of reflective powder and a plurality of nano metal sheets. The composite cooling coating manufacturing method according to claim 16, wherein the reflective powder is titanium dioxide, mica, ceria, calcium carbonate or a combination thereof. The composite cooling coating manufacturing method according to claim 16, wherein the nano metal sheet is sheet-shaped aluminum, zinc, copper, nickel, cobalt, chromium, iron or a combination thereof. The composite cooling coating manufacturing method according to claim 12, wherein the infrared radiator accounts for 50% by weight to 60% by weight of the total composition of the radiation cooling coating, and the sheet filler accounts for 5% by weight of the total composition of the radiation cooling coating. Between 15% by weight, the polymeric binder accounts for between 25% and 45% by weight of the total composition of the radiant cooling coating. The composite cooling coating manufacturing method of claim 12, wherein the apertures of the open-radiation cavities are between 1 mm and 100 mm. The method of fabricating a composite cooling coating according to claim 12, wherein the shape of the open-radiation cavities is square or circular. The composite cooling coating manufacturing method of claim 12, wherein the aperture ratio of the open cavity is between 1% and 50%. The composite cooling coating manufacturing method of claim 12, wherein the substrate is a metal, a non-metal or a combination thereof. The composite cooling coating manufacturing method according to claim 12, wherein the radiant cooling coating is applied to the substrate by a high pressure spraying method. The composite cooling coating manufacturing method of claim 12, wherein the reflective thermal barrier coating is applied to the radiant cooling layer by brushing or high pressure spraying. The composite cooling coating manufacturing method according to claim 1, wherein the open-radiation cavity is in opposition When the thermal barrier coating is applied to the radiant cooling layer, it is formed by brushing or by using a mask and a high pressure spraying method.