Ventilated heat-shielding steel plate

Abstract

This invention provides a heat-shielding steel sheet for ventilation that is highly resistant to high temperatures and has low abrasion resistance, and is used to form a ventilation layer on the inside of building roofs and exterior walls. [Solution] The ventilated heat-shielding steel plate 10 is used on the roof 20 or exterior wall 20 of a building, and is used to form a ventilation layer 21 on the inside of the roof 20 or exterior wall 20 of the building. This ventilated heat-shielding steel plate 10 comprises a steel plate 11 and an aluminum foil sheet 12 attached to the inside of the steel plate 11, which has a flat surface and low air resistance.

Description

Technical Field

[0001] The present invention provides a ventilation heat-insulating steel plate that is strong against high temperatures and has low abrasion resistance by attaching a single aluminum foil sheet to an exterior material provided on the outside of steel plates such as roof and wall steel plates.

Background Art

[0002] A method has been proposed in which a heat-insulating material is pasted on the inside of a roof steel plate or the roof has a double structure, a heat-insulating material is applied inside the outer roof material, and the inside is ventilated (for example, Patent Document 1). Generally, in order to improve workability and construction strength or to obtain a non-combustion certification, the heat-insulating material is composed of a material in which high-purity aluminum foil, which is a material with a high reflectivity to radiant heat, is adhered to one side or both sides of glass fiber by heat welding or the like.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Until now, it was said that the maximum temperature of steel plate roofing materials in factories and other buildings during the summer was around 80°C. Therefore, there was no problem as long as the heat-shielding material could withstand this temperature. Generally, heat-shielding materials used for exterior materials (roofing materials, etc.) are composed of high-purity aluminum foil, a material with high reflectivity against radiant heat, bonded to one or both sides of glass fiber by heat welding or other means to improve workability and construction strength, or to obtain non-combustible certification. An example of such a composition is aluminum foil as the reflective material, polyethylene as the heat-welding material, glass fiber sheet as the reinforcing material, polyethylene as the heat-welding material, and aluminum foil as the reflective material. The problem here is that the heat resistance temperature of polyethylene, the heat-welding material, is 70 to 90°C, and its softening temperature is around 70°C. In other words, it is thought that peeling may occur from 70°C. When heat-shielding material is directly applied to the roofing material, about 10% of the radiant heat from the sun is reflected, but the remaining 90% is absorbed by the roofing material and transferred to the heat-shielding material on the interior side in the form of conductive heat. Currently, roofing materials can reach 80°C in the summer, but applying heat-reflective material to the interior side raises the temperature by another 5°C or more to 85°C. Heat-reflective material that is directly applied in contact with the roofing material will naturally reach this temperature, potentially causing partial peeling or other damage. Most heat-reflective materials have similar structures and materials, and it is highly likely that they will not be able to withstand future temperature increases.

[0005] There is also a ventilation method that uses a double-layer structure for roofs and walls, where a heat-shielding material is installed on the interior side of the outer exterior material, and the inside is ventilated. In the ventilated structure constructed using this method, a ventilation layer is created on the interior side of the heat-shielding material, allowing outside air to flow through. However, the unevenness of the surface of the heat-shielding material is a crucial factor here. The unevenness of the surface of the heat-shielding material is the biggest problem for ventilation methods (ventilated structures), as it not only increases air abrasion due to ventilation, but also raises concerns about contact with fine particles such as dust and dirt from outside, potentially damaging the surface of the soft aluminum foil. As mentioned above, the heat-shielding materials currently in use have a fiber base and the aluminum foil is thin, resulting in many uneven surfaces.

[0006] Therefore, the present invention aims to provide a heat-shielding steel sheet for ventilation that is resistant to high temperatures and has low abrasion resistance, and which can be used to form a ventilation layer on the inside of the roof or exterior wall of a building. [Means for solving the problem]

[0007] The ventilated heat-shielding steel sheet according to the present invention is used for the roof or exterior wall of a building, and is used to form a ventilation layer on the inside of the roof or exterior wall of a building, and is characterized by comprising a steel sheet and a single sheet of aluminum foil attached to the inside of the steel sheet, having a flat surface and low air resistance.

[0008] The ventilated heat-shielding steel sheet according to the present invention is characterized in that a highly permeable resin layer that transmits radiant heat well is provided on one or both sides of an aluminum foil sheet.

[0009] The ventilated heat-shielding steel sheet according to the present invention is characterized in that a steel sheet, a first highly permeable resin layer that transmits radiant heat well, an aluminum foil sheet, and a second highly permeable resin layer that transmits radiant heat well are sequentially laminated from the outside of the roof or exterior wall of a building, and multiple adhesive layers are provided between the steel sheet and the first highly permeable resin layer to partially bond the steel sheet and the first highly permeable resin layer. [Effects of the Invention]

[0010] The ventilated heat-shielding steel sheet according to the present invention uses a single sheet of aluminum foil with a flat surface and low air resistance. This allows air to flow smoothly through the ventilation layer formed between the ventilated heat-shielding steel sheet and the exterior material (wall material or roofing material), reducing wear between the aluminum foil sheet and the air, and enabling long-term use without degrading the function of the aluminum foil sheet. Furthermore, because the ventilated heat-shielding steel sheet according to the present invention is directly attached to the steel sheet using an acrylic adhesive, it is possible to prevent the aluminum foil sheet from peeling off the steel sheet even when the ventilated heat-shielding steel sheet reaches temperatures of 80°C or higher in the summer.

[0011] The heat-shielding steel sheet for ventilation according to the present invention significantly reduces processing costs by reducing the amount of materials that make up the heat-shielding material. As a result, the price of this heat-shielding steel sheet for ventilation can also be reduced, making it usable in a wide range of fields. Furthermore, the development of a method for partially bonding aluminum foil sheets to the steel sheet enables continuous production using mechanical means, further improving productivity and reducing costs. [Brief explanation of the drawing]

[0012] [Figure 1] This is a diagram illustrating the flow of fluid (air) inside a pipe. [Figure 2] This diagram illustrates the movement of air flowing through the ventilation layer when a double-layered roof structure is formed. [Figure 3] This diagram illustrates the movement of air flowing through a ventilation layer when a double-layered wall is formed and the inner wall has irregularities. [Figure 4] This is a cross-sectional view of a ventilated heat-shielding steel plate according to an embodiment of the present invention, where (a) is a ventilated heat-shielding steel plate formed in an uneven shape, and (b) is a ventilated heat-shielding steel plate formed in a flat shape. [Figure 5] This figure shows a ventilated heat-shielding steel plate according to an embodiment of the present invention attached to an exterior member. [Figure 6] This figure shows an example in which a single sheet of aluminum foil or the like is attached to a ventilated heat-shielding steel plate according to an embodiment of the present invention by partial adhesion. [Modes for carrying out the invention]

[0013] The climate is rapidly changing, shifting from an era of global warming to an era of global boiling. In Japan, Kumagaya City recorded a temperature of 41.4°C in 2017, and in Discovery, California, USA, it reached a staggering 54.4°C. Consequently, phenomena that cannot be overlooked by conventional standards are rapidly increasing.

[0014] It is known that while applying heat shielding to the interior side of exterior materials is effective against heat from the outside, it also retains heat generated from inside, significantly reducing the heat shielding effect. Therefore, a new technology has been developed: a ventilated construction method that uses a double-layered structure for the exterior materials, with heat shielding material placed between them, and an air ventilator inside. This new method utilizes the low radiance properties of the heat shielding material, and by constantly expelling the small amount of heat radiated to the outside, it is possible to obtain highly efficient and stable heat shielding performance. To enhance the durability of this method, it is important to take measures to prevent wear and tear between the heat shielding material and the air.

[0015] These problems can be broadly categorized into four main issues. The first is the wear of the heat-shielding material due to the air flowing through the double-layered ventilation structure. Until now, heat-shielding materials have been primarily used in a state where the air is still, and have not been used in a ventilation layer. However, the heat-shielding effect of ventilated construction is overwhelmingly higher for buildings, and it is certain that this method will increase. Heat-shielding materials are made in a multi-layered structure for construction and strength reasons, but it is unavoidable that irregularities will form on the surface due to the nature of the base material. For example, when using glass fiber, its high rigidity and aluminum foil's thinness mean that when the two are heat-welded together, the shape of the fibers will inevitably appear on the surface. Also, when using thin resin sheets as the base material, irregularities are likely to occur on the surface of the heat-shielding material due to resin shrinkage, etc.

[0016] The best mode for carrying out the present invention will be described below with reference to Figures 1 to 6.

[0017] As shown in Figure 1, considering the fluid flowing through the inside (ventilation layer) 102 of the cylindrical pipe 100, generally, if the fluid (air) F flowing through the ventilation layer is laminar, the flow velocity will be faster in the center of the ventilation layer and zero on the inner wall surface 101 side. Therefore, it is considered that there is almost no wear between the inner wall surface 101 and the air F.

[0018] When a ventilation layer 5 is formed on the roof between an exterior member 2 provided with a heat insulating material 4 on the inner side and an interior member 3 facing the exterior member 2, as shown in Fig. 2, due to the inclination, high-temperature heat flows in such a way that pressure is applied to the upper part in the ventilation layer 5 by buoyancy, causing friction between the heat insulating material 4 and the air F, which becomes a cause of wear of the heat insulating material 4. Also, when a ventilation layer 5 is formed on a wall between an exterior member 2 provided with a heat insulating material 4 on the inner side and an interior member 3 facing the exterior member 2, as shown in Fig. 3, the ventilation layer 5 is formed in the vertical direction Y (the vertical direction). Turbulent flow is generated not only by mounting members such as eaves but also by the unevenness 6 on the surface of the heat insulating material 4 and the unevenness 6 on the surface of the interior member 3, etc., and wear of the heat insulating material 4 is more concerning. Since the fluid F flows in a laminar flow with the least friction against the wall surface, it is important how to reduce the unevenness 6 on the surface of the members constituting the ventilation layer 5.

[0019] Second, most of the currently used heat insulating materials are generally for a use range of approximately -30°C to 80°C. It is expected that the temperature of the roof will exceed 85°C in the future, making it difficult to use the existing heat insulating materials. In general heat insulating materials, a reinforcing material is used to increase the strength of the aluminum foil, which is a reflective material. The reinforcing material itself is generally heat-resistant and there is no problem, but it is desirable to consider changes such as the heat welding material that adheres the aluminum foil and the reinforcing material.

[0020] Third, when air is taken into the ventilation layer, fine materials such as sand, dust, and powder will collide with the soft surface of the heat insulating material, causing scratching wear, which may lead to a decrease in the performance of the heat insulating material and in some cases, destruction of the heat insulating material. Currently, the thickness of the aluminum foil used in the heat insulating material is 5μm to 10μm, and there is a concern that it will be easily damaged.

[0021] Fourth, when a ventilation layer is provided, acidic and alkaline substances from the outside constantly penetrate into the ventilation layer. Aluminum foil is weak against both acids and alkalis, and contact with these components will cause corrosion. Therefore, it is necessary to protect the heat insulating material from these materials.

[0022] The ventilated heat-shielding steel sheet 10 according to the present invention is used for the roof or exterior wall of a building, and is used to form a ventilation layer 21 on the inside of the roof or exterior wall of a building. As shown in Figure 4, this ventilated heat-shielding steel sheet 10 comprises a steel sheet 11 and an aluminum foil sheet 12 attached to the inside of the steel sheet 11, which has a flat surface and low air resistance. This aluminum foil sheet 12 is bonded to the steel sheet 11 via an adhesive layer 14. In the ventilated heat-shielding steel sheet 10, one aluminum foil sheet 12 is bonded to the steel sheet 11. For the adhesive layer 14, for example, an acrylic adhesive is used. Furthermore, the ventilated heat-shielding steel sheet 10 can be composed only of the steel sheet 11 and the aluminum foil sheet 12 bonded to the inside of the steel sheet 11.

[0023] The ventilated heat-shielding steel sheet 10 according to the present invention is made by directly attaching an aluminum foil sheet 12 to a steel sheet 11 used for roofs, walls, etc., via an adhesive layer 14. In this invention, since the aluminum foil sheet 12 is directly attached to the steel sheet 11, the strength of the aluminum foil sheet 12 is not necessary; rather, a smooth surface with low air resistance and high radiant heat reflectivity is important. This invention focuses on this point and makes it possible to utilize the maximum performance of the aluminum foil sheet 12. When the aluminum foil sheet 12 is rolled, due to the process, one side becomes a textured surface with many irregularities, and the other side becomes a shiny, smooth surface. The aluminum foil sheet 12 manufactured by rolling is an aluminum plate material.

[0024] As shown in Figure 5(a), the ventilated heat-shielding steel plate 10 of the present invention is used by being attached to the outside of the exterior member (roofing material) 20, or as shown in Figure 5(b), to the outside of the exterior member (wall material) 20. A ventilation layer 21 is formed between the ventilated heat-shielding steel plate 10 and the exterior member 20. In this way, a double roof structure or a double wall structure is formed by the ventilated heat-shielding steel plate 10 and the exterior member 20. In order to pursue a smooth surface, the ventilated heat-shielding steel plate 10 of the present invention uses a slightly shiny side facing the ventilation layer 21. As for heat resistance, since it is made of aluminum foil, it goes without saying that it can withstand high temperatures.

[0025] Heat-reflective materials are commonly used to reflect radiant heat. When used between walls and exterior walls or in ceiling spaces, a certain degree of strength is required. Therefore, all heat-reflective materials are reinforced by sandwiching non-woven fabric, glass cloth, or resin mats between or on one side of the aluminum foil, creating a composite structure with increased strength. For example, non-combustible heat-reflective materials used in roofing materials consist of five layers: aluminum foil (radiant heat reflector), heat-sealing material, glass cloth (reinforcement material to increase strength), heat-sealing material, and aluminum foil (radiant heat reflector). The aluminum foil used in heat-reflective materials is typically very thin, ranging from 5 to 10 μm. When these materials are heat-sealed, the unevenness of the glass cloth fibers becomes clearly visible on the surface. This unevenness is a major cause of air abrasion within the ventilation layer.

[0026] On the other hand, in the present invention, since a smooth aluminum foil sheet 12 is used, which is obtained by rolling an aluminum ingot, no irregularities are formed on the surface of the aluminum foil sheet 12, and there is absolutely no concern about air abrasion in the ventilation layer 21.

[0027] As mentioned earlier, heat-shielding materials are composites, and the most important component to pay attention to is the heat-sealing material. Because heat-sealing materials are welded together, their melting point and softening temperature are lower than those of aluminum foil or reinforcing materials like glass cloth. Generally, polyethylene is used, and it softens at around 70°C. The typical operating temperature range for heat-shielding materials is around -30°C to +80°C. Therefore, considering that the upper limit is 80°C, it is undoubtedly an extremely tight temperature range. In the future, roof temperatures may rise to as high as 85-90°C, making direct application of heat-shielding materials extremely risky.

[0028] In the ventilated heat-shielding steel plate 10 according to the present invention, an aluminum foil sheet 12 is used, and an acrylic adhesive is used for bonding with the steel plate, thus solving the above-mentioned problems.

[0029] The aluminum foil sheet 12 used in this invention is preferably 30 μm to 80 μm thick, which is considerably thicker than the aluminum foil used as a heat shield (5 μm to 10 μm). This thickness allows the foil to withstand some surface damage over a long period of time. Of course, even thicker foils are possible, but this would lead to problems such as increased weight and higher cost.

[0030] Furthermore, the ventilated heat-shielding steel sheet 10 according to the present invention may also be provided with a highly permeable resin layer 13 that transmits radiant heat well on one or both sides of the aluminum foil sheet 12 (Figure 4).

[0031] The highly permeable resin layer 13, which transmits radiant heat well, is a thin film of resin, approximately 5 μm thick. When used between the steel plate 11 and the aluminum foil sheet 12, this thin film serves to prevent galvanic corrosion, while when used on the ventilation layer 21 side, it also serves to protect the aluminum foil sheet 12 from acidic and alkaline substances in the air.

[0032] In the ventilated heat-shielding steel sheet 10 according to the present invention, when the steel sheet 11 and the aluminum foil sheet 12 are bonded by a method such as full-surface adhesive bonding, the adhesive itself serves to prevent galvanic corrosion, so the structure is used as is. When producing the ventilated heat-shielding steel sheet 10, there are two methods depending on the production volume, such as manually attaching the aluminum foil sheet 12 or attaching it by machine, but in either case there is no problem with the performance, and it is manufactured using the method that is easiest to produce.

[0033] Since the ventilated heat-shielding steel sheet 10 is used in double-roof or double-wall structures where air flows inside, the inside of the ventilated heat-shielding steel sheet 10 is constantly in contact with the flowing air. Because air contains salt and alkaline components, a surface treatment that can deal with this is necessary. This can be addressed by the aforementioned highly permeable resin layer 13 that transmits radiant heat well.

[0034] As shown in Figure 6, the ventilated heat-shielding steel sheet 10 of the present invention is constructed by sequentially laminating a steel sheet 11, a first highly permeable resin layer 15 that transmits radiant heat well, an aluminum foil sheet 12, and a second highly permeable resin layer 13 that transmits radiant heat well, from the outside of the roof or exterior wall of a building. Multiple adhesive layers 14 are provided between the steel sheet 11 and the first highly permeable resin layer 15 to partially bond the steel sheet 11 and the first highly permeable resin layer 15.

[0035] When steel sheets for exteriors such as roofs and exterior walls are automatically bonded to heat-insulating materials on a manufacturing line, air can be trapped, creating bubbles. Generally, one method is to puncture the heat-insulating material to remove the bubbles, but these punctures then become a source of air abrasion.

[0036] To solve this problem, a highly permeable resin layer 15 that transmits radiant heat well is provided on the steel plate 11 side of the aluminum foil sheet 12, and the adhesive is applied only partially, thereby creating an air layer between the steel plate 11 and the aluminum foil sheet 12. As a result, galvanic corrosion between the steel plate 11 and the aluminum foil sheet 12 is prevented, and problems such as blistering due to air are also eliminated. Since the present invention relies solely on low radiation performance, such issues on the reflective side do not cause a decrease in performance on the radiating side. In this case, the ventilated heat-shielding steel plate 10 has a five-layer structure consisting of a steel plate 11, a partially formed adhesive layer (partial adhesive layer) 14, a highly permeable resin layer 15 that transmits radiant heat well, an aluminum foil sheet 12, and a highly permeable resin layer 13 that transmits radiant heat well.

[0037] In this invention, the aluminum foil sheet 12 used has an aluminum foil purity of 99.5% and a reflectivity of 98% or higher. However, due to the aforementioned surface treatment, the final reflectivity is approximately 95%. Generally, heat shielding materials consist of aluminum foil 5 μm to 7 μm thick, and the total thickness including the base material is 0.2 mm to 0.3 mm, but in this invention, since only aluminum foil 12 is used, the thickness is approximately 30 μm to 80 μm.

[0038] The history of using heat-shielding materials worldwide spans over a hundred years, but it has always been understood that heat-shielding materials are materials that reflect radiant heat and therefore require a reflective space. To create this reflective space, the heat-shielding material needs to be fixed to components such as furring strips, and strength is also important. Therefore, heat-shielding materials have not been thin aluminum foil alone, but have been used as composite materials in combination with other base materials.

[0039] The method of blocking radiant heat by applying heat-shielding material to exterior steel plates such as roofs and exterior walls was developed around 2013, which is quite recent. The reason why such an excellent technology had not been adopted until now stems from the fact that the basic idea was that most heat transfer is by conduction, and surface temperature was measured by sandwiching thermocouples on both sides of the test specimen, that is, by measuring conduction heat. In other words, no matter how reflective a material is, when the temperature is measured by sandwiching it, the temperature difference between the two sides hardly changes, so it was judged to be poor performance. The reality is that it was not generally understood that radiant heat cannot be measured by contact methods.

[0040] In recent years, there has been an increasing trend to apply heat-reflective materials to exterior cladding used for roofs and walls. The problem here is rising temperatures. With global warming, temperatures are rising year by year, and the temperature of cladding, which was previously said to be around 80°C, is on an upward trend. Furthermore, if the material is applied to the radiant side, the inside (indoor side), the temperature of the cladding will rise by at least 5 to 8°C. Therefore, considering these factors, it becomes difficult to use heat-reflective materials unless their heat resistance temperature is at least close to 90°C.

[0041] Many current heat-shielding materials consist of aluminum foil as a reflective material, polyethylene as a heat-sealing material, glass fiber or polyester sheet as a reinforcing material, polyethylene as a heat-sealing material, and aluminum foil as a reflective material. While the reflective and reinforcing materials have sufficient heat resistance, the polyethylene heat-sealing material softens at around 70°C, raising concerns about the heat-shielding material itself peeling off. Since radiant heat reflection occurs on the surface of the aluminum foil, it doesn't need to be very thick and doesn't require a composite structure. Therefore, to solve these problems, aluminum foil alone should be used as a substitute for the heat-shielding material, and an acrylic adhesive should be used for bonding. In this way, all heat-related problems can be resolved.

[0042] Recently, a new construction method has emerged that uses a double-layer structure for exterior materials such as roofs and walls, with a reflective material placed between them, and ventilation on the radiating side. Until now, heat-shielding materials have primarily been used in stationary spaces and have not been used in ventilated environments, but this presents new problems. Firstly, laminar flow is preferable for the air flowing between the exterior material and the heat-shielding material. However, in reality, there is a temperature difference between the exterior material and the heat-shielding material, and heat moves in a direction perpendicular to the flow according to the principle that heat moves from high temperature to low temperature. Furthermore, because roofs are sloped, the hot air rises due to buoyancy and moves along the upper wall surface. In addition, in walls, obstacles such as furring strips and tight frames are present within the ventilation layer, resulting in turbulent flow due to various factors. In other words, friction between the heat-shielding material and the air increases, potentially leading to increased wear of the heat-shielding material. To mitigate this, the hardness of the aluminum foil itself could be increased, but purity is important for improving the performance of aluminum foil, and increasing purity decreases hardness, so this method cannot solve the problem as they have conflicting properties.

[0043] Therefore, to minimize friction, it is important to make the surface of the heat-shielding material smooth. However, heat-shielding materials used for roofing must be non-combustible and use glass fiber sheets as a reinforcing material. Glass fiber sheets are made by layering rigid glass fibers, resulting in an uneven surface. When these are heat-welded to create a heat-shielding material, the thin aluminum foil on the surface softens when heat is applied and adheres to the glass fiber side, resulting in an uneven surface on the heat-shielding material, making it difficult to make it flat. On the other hand, aluminum foil is an aluminum film made by rolling aluminum ingots into a thin film, and its surface is smooth. Therefore, using aluminum foil alone is effective in this case as well.

[0044] Secondly, the air flowing through the ventilation layer contains dust and dirt. These substances come into contact with the soft aluminum foil, causing scratching and abrasion that damages the surface, potentially reducing or destroying its heat-shielding performance. To remove dust, dust filters can be installed at the air intakes, but this would be an extremely large undertaking for the entire building, significantly increasing maintenance costs. Another way to reduce this abrasion is to increase the surface hardness of the aluminum foil, but as mentioned earlier, it is impossible to make aluminum foil extremely hard. Furthermore, although aluminum foil is said to be highly durable due to the formation of an oxide film, this is only true in the case of still air; it is extremely difficult for it to withstand prolonged impact from dust and other particles.

[0045] Therefore, in the ventilated heat-shielding steel plate 10 of the present invention, surface snagging can be reduced by using an aluminum foil sheet 12, thereby addressing this problem. Furthermore, while the thickness of general heat-shielding materials is approximately 5 μm to 10 μm, the present invention uses an aluminum foil sheet 12 with a thickness of 30 μm to 80 μm. Of course, a slightly thicker aluminum foil sheet 12 could also be used, but the decision should be made based on a balance between weight and cost.

[0046] Thirdly, by utilizing the atmosphere, there is a possibility of incorporating acidic or alkaline components. For example, it is a well known fact that areas near the sea have high alkaline content. This is called corrosive wear, and to address this, a resin layer 13 that transmits radiant heat well is provided on the surface of the aluminum foil sheet 12. The thickness of this resin layer 13 is generally within 5 μm, as increasing its thickness reduces its heat shielding performance.

[0047] Thus, as a method to withstand future temperature increases, and to ensure that ventilation methods utilizing atmospheric air can be used without problems over the long term, the ventilated heat-shielding steel plate 10, which has a single sheet of aluminum foil 12 attached to a steel plate 11, is a simple structure but is extremely important and groundbreaking.

[0048] [Test 1] A steel plate measuring 0.6 mm thick, 20 cm wide, and 25 cm high was fitted with a heat-shielding material (THB-FX) on one side of test specimen (1) and a single sheet of aluminum foil (30 μm) on test specimen (2). Both specimens were set up 30 cm in front of a 1 KW far-infrared heater, with the aluminum foil side facing away from the heater. The temperature of the aluminum foil side was measured using a thermograph. The room temperature was 25°C. Test specimen (1): THB-FX (textured surface) 0.2 mm Test specimen (2): Aluminum foil sheet (shiny surface) 30 μm

[0049] [Result 1] Test specimen (1): Temperature 35.3℃ Test specimen (2): Temperature 34.7℃

[0050] [Consideration 1] Thermographic temperature measurements show that the aluminum foil sheet, which is test specimen (2), performs slightly better, by 0.6°C.

[0051] Next, the effects and advantages of the ventilated heat-shielding steel plate 10 according to the present invention will be explained.

[0052] The ventilated heat-shielding steel sheet 10 according to the present invention uses an aluminum foil sheet 12 with a flat surface and low air resistance. As a result, the air flowing through the ventilation layer 21 formed between the ventilated heat-shielding steel sheet 10 and the exterior member (wall material or roofing material) 20 becomes smoother, reducing wear between the aluminum foil sheet 12 and the air. Therefore, the aluminum foil sheet 12 can be used for a long period of time without degrading its function.

[0053] The ventilated heat-shielding steel plate 10 according to the present invention has an aluminum foil sheet 12 directly attached to the steel plate 11 using an acrylic adhesive. Therefore, even when the ventilated heat-shielding steel plate 10 reaches temperatures of 80°C or higher in the summer, the aluminum foil sheet 12 is prevented from peeling off the steel plate 11. Thus, by using this ventilated heat-shielding steel plate 10, stable heat-shielding performance can be maintained.

[0054] In the ventilated heat-shielding steel sheet 10 according to the present invention, an aluminum foil sheet 12 is used instead of the conventional heat-shielding material, thus reducing the number of constituent materials of the conventional heat-shielding material. As a result, processing costs are significantly reduced, and the product price of the ventilated heat-shielding steel sheet 10 can also be reduced, making it possible to use it in many fields.

[0055] Furthermore, if a method is developed to partially bond an aluminum foil sheet 12 to a steel plate 11, as in the heat-shielding steel plate 10 according to the present invention, continuous production by mechanical use becomes possible, further improving productivity and reducing costs.

[0056] The ventilated heat-shielding steel plate 10 according to the present invention has an aluminum foil sheet 12 installed on the inside of the steel plate 11, but since glass is often used in high-rise buildings, it can also be used on the inside of the glass in that case.

[0057] Although this embodiment has been described above, it is possible to select or replace the configurations listed in the above embodiment, or to change them to other configurations as appropriate, as long as they do not deviate from the spirit of the present invention. [Explanation of Symbols]

[0058] 2 Outer cladding material 3. Interior exterior material 4 Heat shield material 5. Ventilation layer 6 Unevenness 10. Heat-shielding steel plate for ventilation 11 Steel plate 12 sheets of aluminum foil 13 Highly transparent resin layer (second highly transparent resin layer) 14 Adhesive layer 15 Highly transparent resin layer (first highly transparent resin layer) 20. Exterior components (roofing materials, exterior wall materials) 21 Ventilation layer 100 tubes 101 Interior wall surface 102 Interior (ventilation layer) F Fluid (Air) X Anteroposterior direction Y: Vertical direction (up and down)

Claims

1. A ventilated heat-shielding steel sheet used for the roof or exterior wall of a building, which is used to form a ventilation layer on the inside of the roof or exterior wall of the building, It comprises a steel plate and a single sheet of aluminum foil attached to the inside of the steel plate, having a flat surface and low air resistance. A heat-shielding steel plate for ventilation, characterized by the following features.

2. One or both sides of the aluminum foil sheet are provided with a highly permeable resin layer that transmits radiant heat well. The ventilated heat-shielding steel plate according to feature 1.

3. The building's roof or exterior wall is constructed by sequentially laminating the steel plate, a first highly permeable resin layer that transmits radiant heat well, the aluminum foil sheet, and a second highly permeable resin layer that transmits radiant heat well, from the outside of the building. Multiple adhesive layers are provided between the steel plate and the first highly permeable resin layer to partially bond the steel plate and the first highly permeable resin layer. The ventilated heat-shielding steel plate according to feature 1.

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