PH12014502212B1

PH12014502212B1 - Heat insulating plate

Info

Publication number: PH12014502212B1
Application number: PH12014502212A
Authority: PH
Inventors: Noguchi Shuhei; Noguchi Ayano; Amano Naoki
Original assignee: Nihon Shanetu Co Ltd
Priority date: 2012-07-30
Filing date: 2014-10-01
Publication date: 2015-01-12
Also published as: PH12014502212A1; WO2014021237A1; JP5322070B1; JP2014043762A

Abstract

Provided is a heat-insulating plate capable of being used for newly constructed buildings and existing buildings and of being used as an inexpensive and highly energy-saving metal external wall material, metal roofing material, metal shutter material, etc. This heat-insulating plate is characterized in that a heat-insulating layer (2), which comprises a layer of a material that has a high reflectance with respect to radiant heat, is provided on either the front or the back surface of a base material (metal substrate (1)) without interposing an air layer and the surface on which said heat-insulating layer has been provided is used as the surface on the opposite side from the surface that is directly or indirectly irradiated by sunlight.

Description

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RE - ARSE —

DESCRIPTION

Title of Invention: HEAT-SHIELDING PLATE

Technical Field

The present invention provides a heat-shielding plate which can be used for newly constructed buildings and existing buildings and which can be used as an inexpensive and highly energy-saving metal external wall material, metal roofing material, metal shutter material, or the like.

Background Art

In most of steel-framed buildings, such as factories and warehouses, as fire prevention measure, metal plates, for example, metal roofing materials, metal external wall materials, or metal shutters are used. However, although, for these metal plates, sheets or the like as measures against dew condensation are used, a heat-insulating material is scarcely used.

For example, in a steel-framed building, such as a factory or warehouse, many facilities are installed therein, the area of a floor is very large, and, in order to install a crane or the like on a ceiling or to take a measure against heat using convection heat, the roof height is high.

In addition, the area of a wall is designed to be markedly : large, compared with those of Jjeneral office buildings. a doorway is often left open for, for example, carrying in or out products. If indoor air-conditioning equipment is installed, it costs a great deal of money and has very high running costs. Thus, in most of warehouses and factories, even heat insulation work is not done under present circumstances.

Shutters wound around winding drums are often used for, for example, stores and factories. However, few shutters have ever been subjected to heat insulation work.

Furthermore, in the case of agricultural buildings, such as poultry houses and cattle sheds, metal roofs are corroded in a short period of time by alkaline substances generated from livestock excreta. Thus, slate roofs have been used for most of these agricultural buildings. However, after revealing asbestos problems of slate roofing materials, : non-slate roofing proceeds. In newly constructed buildings, roofing materials are being replaced with metal folded-plate ) roofing materials. However, there are a few metal roofing ; materials that can prevent corrosion due to alkaline substances.

Summary of Invention

Problems to be solved by the invention ~ Accordingly, there have been problems as described below. :

First, most of steel-framed buildings, such as factories and warehouses, have metal roofs, such as folded- plate roofs. Although some of the metal roofs use thin sheets for preventing dew condensation, the metal roofs are scarcely subjected to heat insulation work. Moreover, also as external walls, metal plates that are not equipped with heat-insulating materials are used. Thus, the insides of the buildings are very hot in summer and, conversely, cold in winter, which are hostile work environments.

If heat insulation work or heat shielding work is performed on the indoor sides of these metal roofs and external walls, heating and cooling efficiency is also improved, and work environments can also be significantly changed. However, as described above, there has been a problem of a high installation cost. Moreover, most of shutters installed on wall surfaces are not subjected to heat insulation work. This is also a factor in reducing thermal efficiency of insides of the buildings. The reason for this is that as described above, the shutters wound around winding drums are used. There has been a problem in which if heat-insulating materials are mounted on shutter materials, the winding drums are excessively large, thereby leading to difficulty in practically using them. Moreover, if the heat-insulating materials are thinned, a heat insulation effect is low. Furthermore, if the heat - ;

Co - insulating materials are mounted, the heat-insulating materials can be easily fallen off because the shutters are always moved. Thus, nothing is made on most of the shutters under present circumstances.

Furthermore, in most of agricultural buildings, such as poultry houses and cattle sheds, slate roofing materials were previously used as described above. In recent years, metal folded-plate roofing materials have been used. There have been problems similar to those in the foregoing buildings, such as factories and warehouses.

In addition, in agricultural buildings, such as poultry houses and cattle sheds, as a cause of a pronounced stress that affects weight gain in animals for meat and so forth, there is a natural phenomenon called the black globe phenomenon. This is a phenomenon which occurs at an air temperature higher than 25°C and which causes a problem in which the productivity of chickens, swine, cattle, and so forth is significantly reduced. To block this phenomenon, it is an important problem how to reduce the amount of radiant heat emitted from roofs and external walls, However, ) most of slate roofing materials, metal roofing materials, external wall materials, or the like emit a large amount of radiant heat. It is thus doubtful whether the productivity is improved. Moreover, the mortality rate of chickens and so forth tends to be increasing year by year.

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Furthermore, in buildings, roofs of station buildings and distribution centers without a wall, lean-to roofs around buildings, and so forth are assumed to be environments where the wind blows from the outside. When strong winds of a typhoon or the like blow in buildings, markedly high wind pressures are applied to ceilings.

Lightweight heat-insulating materials and so forth are detached or blown off by the wind pressures and thus cannot be used at all.

Accordingly, it is an object of the present invention to propose a heat-shielding plate which can be used for newly constructed buildings and existing buildings and which can be used as an inexpensive and highly energy-saving external wall material, roofing material, shutter material, or the like. ‘Means for solving the problem

The present invention has been proposed in light of the foregoing description and relates to a heat-shielding plate characterized in that a heat-shielding layer serving as a layer composed of a material having high reflectance for radiant heat is provided on one of the front and back sides of a base material without interposing an air layer, the base material being used as any one of an external wall material, a roofing material, and a shutter material for a :

building directly irradiated with sunlight, and in that the side where the heat-shielding layer is provided is exposed on an indoor side opposite a side directly irradiated with sunlight. 5 The "high reflectance" refers to a reflectance of about 80% to about 90% or more. The "layer composed of a material having high reflectance for radiant heat" is also referred to simply as a "high-reflectance layer" in the following description.

The present invention also proposes that the heat- shielding plate be characterized in that the high- reflectance layer is an aluminum layer.

The "aluminum layer" may be plate-like (film-like) aluminum foil (also referred to as aluminum foil) typically having a thickness of 0.005 to 0.035 mm and may be a more ultrathin evaporated aluminum layer. ]

The present invention als» proposes that the heat- shielding plate be characterized in that an electrolytic corrosion-preventive layer formed of one selected from a chemical fiber sheet, a resin sheet, a resin film, and a resin coating is interposed between a metal substrate and the heat-shielding layer serving as a layer composed of a material having high reflectance for radiant heat.

Advantageous Effects of Invention oo Co oo 7

In the heat-shielding plate of the present invention, the heat-shielding layer serving as the layer composed of the material having high reflectance for radiant heat, i.e., low emissivity, is provided on a side (indoor side) of the base material. Thus, for example, for a warm season, such as summer months, heat received from the outdoor side is scarcely radiated to the indoor side. Thereby, the indoor side can be kept cool. In contrast, for example, for a cool season, such as winter months, radiant heat from the indoor side is reflected toward the indoor side to be able to keep the inside of the building warm. It is thus possible to significantly improve heating and cooling efficiency of the inside of the building and appropriately improve an indoor temperature environment. Thus, nobody freezes with cold or suffers heat stroke caused by heat.

Moreover, the indoor-side surface of the heat-shielding plate of the present invention is the high-reflectance layer, such as an aluminum layer; hence, there is no problem even ] if strong winds of a typhoon or the like blow in.

Accordingly, the heat-shielding plate of the present invention may also be used for buildings that are not provided with a wall, such as station buildings and distribution centers, without any difficulty. 1In addition, on-site installation work may be performed in just the same : way as conventional work. There is no need for a new facility or tool. Thus, the installation cost is low.

Furthermore, the thickness after formation is increased only by about 0.1 to about 0.2 mm, compared with common metal plates. It is thus possible to significantly reduce the transportation cost. Since the entire thickness is very small, the heat-shielding plate is easily subjected to bending with, for example, a galvanized iron roof forming machine or a folded-plate forming machine. It is possible to easily produce a long product having a length of 50 to 100 m in a short period of time. :

In the case where the high-reflectance layer is an aluminum layer, the reflectance is as high as 97% to 98%, and the emissivity is as low as 3% to 2%. It is thus possible to sufficiently provide the effects regarding the low emission property and the high reflection property.

Moreover, since the aluminum foil (aluminum foil) or an aluminum evaporation coating, which are highly reliable as industrial products, is used, bonding work with the metal substrate is easily performed, and the material cost is low.

When an electrolytic corrosion-preventive layer that is any one of a chemical fiber sheet, a resin sheet, a resin film, and a resin coating is provided between the metal substrate and the heat-shielding layer that is a layer composed of a material having high reflectance for radiant heat, even in the case where the base material is a metal :

substrate and where the high-reflectance layer is composed : of a metal material, such as an aluminum layer, it is possible to prevent electrolytic corrosion that can be caused by the contact between the metal material and the metal substrate. Moreover, the electrolytic corrosion- preventive layer formed of a chemical fiber sheet or a resin coating and so forth may be a thin layer with a thickness of about 0.1 to about 0.2 mm. Thus, also in the case where this heat-shielding plate is subjected to any forming process, for example, a roofing material or a shutter material, any forming process may be performed without inhibiting the forming process. Furthermore, the thickness after the formation is also small, so the resulting plate is lightweight and is not bulky. It is thus possible to significantly reduce the management cost and the transportation cost. In addition, the electrolytic corrosion-preventive layer is effective against acid and alkali.

In the case where the heat-shielding plate is used as an external wall material, a roofing material, or a shutter material for a building, the heat-shielding plate having this structure may be subjected to a forming process in just the same way as in conventional external wall materials, roofing materials, and shutter materials formed of metal plates. The on-site installation work may also be performed in just the same way as conventional work. It is thus possible to achieve a low installation cost, compared with the case where heat insulation work or heat shielding work is separately performed.

The heat-shielding plate of the present invention is not limited to the case where the heat-shielding plate itself is subjected to a forming process for an external wall material, a roofing material, or a shutter material.

For example, a known roofing tile (for example, a Japanese roof tile or western roof tile), a concrete block, a steel product, or the like is used as a base material. The additional installation of the heat-shielding layer inside the base material results in a heat-shielding plate of the present invention. It is thus possible to easily impart the foregoing heat shielding effect to the roofing tile, the concrete block, the steel product, or the like. :

Brief Description of Drawings

Fig. 1 is a schematic cross-sectional view of a heat- shielding plate (an embodiment of a structure with a total of three layers) according to an embodiment of the present invention;

Fig. 2 is a schematic cross-sectional view of a heat - shielding plate (an embodiment of a structure with a total of two layers) according to another embodiment of the :

present invention; and

Fig. 3 is a schematic cross-sectional view of a heat- shielding plate (an embodiment of a structure with a total of four layers) according to another embodiment of the present invention.

Description of the Embodiments

Best modes for carrying out the present invention will be described below.

According to reports of many organizations of the U.s., an average of 75% of heat flowing in a building is said to be radiant heat. On top of that, 70% to 93% of heat flowing through a roof is said to be radiant heat. The amount of radiant heat in the direction of a wall is said to be 65% to 80% of all walls. Accordingly, cutting such radiant heat is a most efficient energy-saving construction method.

It is known that, as described above, the execution of heat insulation work or heat shielding work on the indoor sides of a roof and external walls is effective as a method for cutting the radiant heat. However, the work is expensive. A thick heat-insulating material is installed in a tense state, so the management cost and the transportation cost are high. Moreover, a structure in order not to scatter the heat-insulating material inside the building is also necessary. As an example, there is a method in which,

for example, a wool-like heat-insulating material is wound around a column or the like, and then aluminum foil is wound around the outer surface thereof.

The present invention is not an invention directed to insulate heat transfer from a base material located at the outermost surface using a heat-insulating material or the like. The present invention is directed to suppress a rise in the temperature inside the building by the use of a heat- shielding layer composed of a low-emissive material. The present invention has been accomplished by focusing attention on the fact that a heat-shielding layer including a layer composed of a material with high reflectance for radiant heat has low emissive properties.

The sum of the reflectance and the emissivity of a metal is one (1). That is, a substance with high reflectance has low emissivity. A material with high ‘reflectance has a low emission property (= a material with high heat reflectance has a low heat emission property).

For example, aluminum foil (aluminum foil) or an aluminum layer, such as an aluminum evaporation coating, has a reflectance of 97% to 98% for radiant heat. Thus, the emissivity is only 2% to 3%. The material having high reflectance for radiant heat is not limited to aluminum.

For example, a noble metal, e.g., gold or silver, may be used.

The higher reflectance for radiant heat is, the more it is effective. The reflectance of at least 95% or more is desirable.

The biggest factor in increasing the temperature of a substance is radiant heat. Thus, according to the present invention, in the case where the inside of a building is a low-emissive environment, for example, a change in environmental temperature of people or animals, such as chickens or cattle, living inside the building is small without being affected by the outside air temperature even in the extreme-cold winter months and extreme-hot summer months. Moreover, it is possible to reduce changes in the temperature of various substances stored inside the building.

In other words, heat flow transferred in the building is inverted between a warm season, such as summer months, and a cool season, such as winter months. Thus, the low- emissive performance can be effectively used in the warm season. The high reflective performance for radiant heat can be effectively used in the cool season.

As a base material serving as a base of the heat- shielding plate of the present invention, a metal substrate is mainly used. However, a pottery plate, a concrete plate, or a plastic substrate may also be used. In particular, for the metal substrate, a function (property) in response to the purpose is most important, and sufficient stiffness is also required. As the metal substrate, various steel sheets, such as decorative steel sheets, and alloy sheets may be used. For example, the strength properties required for the metal substrate vary, depending on applications (purposes) of using the heat-shielding plate. For example, in an embodiment in which the heat-shielding plate is directly formed before use, in the case of a roofing material, a thickness of about 0.5 to about 1.2 mm is used. In the case of an external wall material, as with common roofing materials, a thickness of about 0.25 to about 0.8 mm is used.

In the case of a shutter material, a thickness of about 0.5 mm is used. Meanwhile, a plastic substrate is used in an embodiment in which the plastic substrate is additionally installed on the inner side of another external wall ; material. Thus, the thickness of the base material is not so important.

As the plastic substrate, various hard resin plates may be used. :

The pottery plate is a roofing tile. The concrete plate is a concrete block. These building materials routinely used may be used as base materials in the present invention. Thus, also in the cases of each of the pottery plate and the concrete plate, the thickness is not so important.

In the heat-shielding plate of the present invention,

the heat-shielding layer having the foregoing structure, high reflectance for radiant heat, and low emissivity is provided on at least one side (indoor side) of the base material having the foregoing structure without interposing an air layer therebetween. If the air layer is present between the base material and the heat-shielding layer, radiant heat radiates from the back side of the base material to the air layer. The air layer itself absorbs the heat. The heat is eventually transferred to the heat- shielding layer. As described above, in the heat-shielding plate of the present invention, the high-reflectance layer (heat -shielding layer), such as an aluminum layer, is : directly mounted on the indoor side of the base material.

In this way, since the high-reflectance layer (heat- shielding layer) is directly mounted on the base material, the low-emissive property of the high-reflectance layer (heat-shielding layer) is used as described above. For example, in a warm season, such as summer months, heat received from the outdoor side is scarcely radiated to the indoor side. Thus, the indoor side can be kept cool.

Specifically, for example, in a warm season, such as summer months, conductive heat, convective heat, or radiant heat from the outside is transferred toward the inside of a building and absorbed by the base material located on the : outermost surface side. The heat is transferred as conductive heat to the high-reflectance layer (heat- shielding layer) located on the back side. Most of the amount of heat is transferred to indoor air in the form of conductive heat or convective heat. Naturally, at this time, radiant heat is radiated. However, since the high- reflectance layer (heat-shielding layer), such as an aluminum layer, is a low-emissivity layer, the amount of heat radiated to the inside of the building is very small.

Conversely, in a cool season, such as winter months, heat in the inside of the building is transferred toward the outside. However, since the high-reflectance layer (heat- shielding layer), such as an aluminum layer, is composed of a material having high reflectance for radiant heat, radiant heat is returned to the inside of the building, thereby providing a heat keeping effect that continuously maintains ; a heating effect.

The heat-shielding plate of the present invention has a structure in which the heat-shielding layer formed of the high-reflectance layer is provided on at least one side of the base material, as described above. The heat-shielding layer formed of the high-reflectance layer may be formed on each of the sides of the base material. An embodiment in which the heat-shielding layer formed of the high- reflectance layer is provided on each of the sides of the base material (in particular, a metal substrate) as :

described above is suitable for specifications, for example, an application, such as a shutter material serving as a partition in a building, e.g., a factory or warehouse.

However, as described above, since the heat-shielding layer is formed only of the high-reflectance layer, such as an aluminum layer, electrolytic corrosion can be caused by contact with the metal substrate (dissimilar metal) of a surface. Thus, an electrolytic corrosion-preventive layer formed of any one of a chemical fiber sheet, e.g., an unwoven fabric or glass cloth, a resin sheet, a resin film, or a resin coating composed of polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET, polyester), or the like is preferably provided between the metal substrate and the high-reflectance layer, such as an aluminum layer. The electrolytic corrosion-preventive layer is effective against acid and alkali.

The electrolytic corrosion-preventive layer, irrespective of an application (for example, a roofing material, an external wall material, or a shutter material), is preferably about 0.1 to about 0.2 mm. Thus, even if the thickness of 7 to 35 pum of the high-reflectance layer, such as an aluminum layer, is added, the heat-shielding layer may be about 0.1 to about 0.25 mm in total.

Accordingly, regarding the thickness of the heat - shielding plate of the present invention, as described above,

since the thickness of the heat-shielding layer is about 0.1 to about 0.25 mm and the thickness of the (metal) base material is about 0.5 to about 1.2 mm, the entire thickness of the heat-shielding plate is about 0.7 to about 1.8 mm, so that rolling and bending can be performed.

Moreover, the electrolytic corrosion-preventive layer prevents the contact between a metal (metal substrate) as the base material and a metal (e.g., aluminum layer) as the high-reflectance layer. The electrolytic corrosion- preventive layer may be provided in order to prevent the contact between the metal substrate and an external metal or between the high-reflectance layer and an external metal.

The electrolytic corrosion-preventive layer used here may be identical to that described above. In view of ] corrosion due to an alkaline substance generated from livestock excreta, a high transmission resin, such as a high-molecular polymer-based film, is preferably bonded. :

As described above, the heat-shielding plate of the present invention may have a structure with a total of two layers, the structure including the heat-shielding layer formed of the high-reflectance layer, such as an aluminum layer, provided on the back side (indoor side) of the base material, or may have a structure with a total of three layers, the structure including two layers consisting of the electrolytic corrosion-preventive layer and the high-

reflectance layer (heat-shielding layer). Examples of the applications of the former structure include pottery tiles, walls, floors, and FRP shutters. They are mainly used for wooden buildings. Examples of the applications of the latter structure include colonials, metallic tiles, and ceramic siding. They are mainly used for wooden buildings.

In addition, for external walls of livestock sheds and so forth, in view of corrosion due to an alkaline substance generated from livestock excreta, the heat-shielding plate preferably has a structure with a total of four layers, the structure including a corrosion-preventive layer provided on the inner side of the high-reflectance layer (heat-shielding layer), such as an aluminum layer. The corrosion-preventive layer is not particularly limited as long as it has resistance to acids and alkalis. The corrosion-preventive layer may be a common layer with the electrolytic corrosion- preventive layer. Examples of the applications of this ] structure include metal roofs, external walls, shutters, doors, ALC roofs, walls, RC roofs, and walls (external wall tiles and artificial marble). They are used for steel- framed buildings, agriculture, high-rise building PC construction methods, and general buildings.

In the case of the structure with a total of two layers, the metal substrate and the heat-shielding layer may be bonded together without interposing an air layer therebetween. In the case of the structure with a total of three layers, after the electrolytic corrosion-preventive layer and the heat-shielding layer are welded or bonded, the welded or bonded sheet may be bonded or welded again in such a manner that the electrolytic corrosion-preventive layer is in direct contact with the metal substrate.

As described above, The unified heat-shielding plates with the structures each having two to four layers in total of the present invention have a very small overall thickness and thus can be processed into any shape with various forming machines.

EMBODIMENTS

While embodiments of the present invention will be described below, the present invention is not limited to these examples. Any configuration may be made without departing from the foregoing claims.

A heat-shielding plate of Embodiment 1 illustrated in

Fig. 1 has composition of a structure with a total of three layers, the structure including an electrolytic corrosion- preventive layer 3 and a high-reflectance layer (heat- shielding layer) 2 formed on the back side of a base material (metal substrate) 1.

A heat-shielding plate of Embodiment 2 illustrated in

Fig. 2 has composition of a structure with a total of two layers, the structure including the high-reflectance layer (heat-shielding layer) 2 formed on the back side of the base material (metal substrate) 1.

A heat-shielding plate of Embodiment 3 illustrated in

Fig. 3 has composition of a structure with a total of four layers, the structure including the electrolytic corrosion- preventive layer 3, the high-reflectance layer (heat- shielding layer) 2, and the electrolytic corrosion- preventive layer 3 formed on the back side of the base material (metal substrate) 1.

Each of Figs. 1 to 3 schematically illustrates a cross- sectional structure. The thickness and so forth are not realistically illustrated.

As the base material (metal substrate) 1 in each of

Examples 1 to 3, a decorative steel sheet having a thickness of 0.5 mm was used. As the high-reflectance layer 2, an aluminum layer (aluminum foil) having a thickness of 15 pm was used. As the electrolytic corrosion-preventive layer 3, a chemical fiber sheet (PE unwoven fabric) having a thickness of 0.3 mm was used.

When the heat-shielding plate illustrated in Fig. 1 was produced, after the electrolytic corrosion-preventive layer ~ 3 and the high-reflectance layer 2 were joined together by welding (specifically, aluminum foil was heat-welded to the unwoven fabric via PE to produce a heat-shielding sheet),

the resulting heat-shielding sheet was bonded (or welded) in such a manner that the electrolytic corrosion-preventive layer 3 was in direct contact with the metal substrate 1 into one component. When the heat-shielding plate illustrated in Fig. 3 was produced, similarly, after the electrolytic corrosion-preventive layer 3, the high- reflectance layer 2, and the electrolytic corrosion- preventive layer 3 were joined by welding, the joined sheet was bonded (joined) to the metal substrate 1 into one component. <Test of heat shielding property 1>

The heat-shielding plates of Example 2 were used and subjected to a forming process for a roofing material and an external wall material, respectively. As a comparative example, metal plates each identical to the metal substrate 1 were used and similarly subjected to a forming process for a roofing material and an external wall material.

In a forming process for the roofing material, a folded-plate roof shape in which ridge portions and valley portions were alternately connected was formed. In a process for the external wall material, a shape in which both sides of a substantially flat central portion slanted upward was formed. [Experimental method]

The heat-shielding plates of Example 2 were used and,

23 oo. as described above, formed into the roofing material and the external wall material, which were used as the example. The metal plates each identical to the metal substrate 1 were used and, as described above, formed into the roofing material and the external wall material, which were used as the comparative example. They were arranged outdoors and allowed to stand under the same conditions. The temperature of the indoor side thereof (a side thereof opposite the side irradiated with sunlight) was measured, and comparisons were made. [Result 1]

At an outside air temperature of 32°C, the temperature of the indoor side of the roofing material of Example 2 was 42.2°C. In contrast, the temperature of the indoor side of the roofing material (the metal substrate 1 alone) of the comparative example was 46.2°C. The difference was 4°C.

At an outside air temperature of 32°C, the temperature of the indoor side of the external wall material of Example 2 was 37.2°C. In contrast, the temperature of the indoor side of the external wall material (the metal substrate 1 alone) of the comparative example was 46.4°C. The difference was 9.2°C. [Discussion]

The heat-shielding plate of Example 2 of the present invention has a very small overall thickness and thus can be easily subjected to any processing (a rolling process or bending and so forth) that provides a surface with the shape of projections and recesses. Accordingly, as with the comparative example consisting of the metal substrate 1 alone, it is possible to easily produce a long product for a short period of time.

In each of the heat-shielding plates of Example 1 to 3, the high-reflectance layer, such as an aluminum layer, was provided on the back side thereof. Thus, even when strong winds of a typhoon and so forth blow in, since the high- reflectance layer, such as an aluminum layer, was provided on the inner side, no problem occurred. ~~ <Test of heat shielding property 2>

A heat-shielding plate having a structure in which a heat-shielding layer consisting of the high-reflectance layer 2 alone was additionally installed inside a concrete block was used as an example. A distance from a heat source (800-W heater) was changed from 100 mm to 500 mm. The temperature of the inside thereof was measured, and comparisons were made. ]

[Result 2] [Table 1]

Distance from 800-W Comparative example (°C) Example (°C) heater without heat shielding with heat shielding 100mm [ ~~ 496 | = 329 [200mm [| 426 | = 315 30mm [| 35 | = 313 400mm | 329 | = 326 500mm | = 296 | = 308 [Discussion]

As is apparent from Table 1, when the distance from the heat source was 100 to 300 mm, the heat-shielding plate of the present invention clearly revealed a heat-shielding effect, compared with the comparative example in which the heat-shielding layer was not present. In contrast, at a distance from the heat source of 400 to 500 mm, the influence of wind and so forth was seemingly reflected in the data.

Explanation of Reference Numerals 1 base material (metal substrate) 2 aluminum layer (high-reflectance layer) 3 electrolytic corrosion-preventive layer 4 external wall material formed of steel sheet

Claims

CLAIMS FD room 1

1. A heat-shielding plate is characterized in that a heat- shielding layer serving as a layer composed of a material having a high reflectance for radiant heat is provided on one of the front and back sides of a base material without interposing an air layer, the base material being used as any one of an external wall material, a roofing material, and a shutter material for a building directly irradiated with sunlight, and in that the side where the heat-shielding layer is provided is exposed on an indoor side opposite a side directly irradiated with sunlight.

2. The heat-shielding plate according to claim 1, wherein characterized in that the heat-shielding layer serving as a layer composed of a material having high reflectance for radiant heat is an aluminum layer.

3. The heat-shielding plate according to claim 1 or 2, wherein characterized in that an electrolytic corrosion- preventive layer formed of one selected from a chemical fiber sheet, a resin sheet, a resin film, and a resin coating is interposed between a metal substrate and the heat-shielding layer serving as a layer composed of a material having high reflectance for radiant heat.