JPH0710609A - Heat-shielding glass and insulating glass produced by using the shielding glass - Google Patents

Abstract

PURPOSE:To obtain a heat-shielding glass by using a heat ray absorbing and ultraviolet shielding glass exhibiting green color mild to the eye as a main material and forming a low-radiation film to shield far infrared rays on the glass and to obtain an insulating glass by using the heat-shielding glass having remarkably excellent heat-shielding property and heat-insulating property. CONSTITUTION:This heat-shielding glass is produced by forming a low-radiation film composed of a multilayer film containing a silver layer and having a vertical emissivity of <=0.2 on (one surface of) a green-colored glass capable of absorbing heat rays and ultraviolet rays. This insulating glass is formed by placing the heat-shielding glass to the outdoor side, a clear glass to the indoor side and the low-radiation film to the inner side face of the heat-shielding glass.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to buildings and the like, which suppresses the incidence of solar energy in the summer to reduce the cooling load,
The present invention relates to a heat-shielding glass that is suitable as an energy-saving window material that suppresses heat radiation from the inside to the outside in the winter and reduces the heating load, and a double-layer glass having the heat-shielding glass.

[0002]

[Prior art and its problems] In the past, to absorb and suppress the incidence of solar radiation on buildings, vehicles, etc., and to reduce the cooling load at high temperatures, so-called blue glass, bronze colored glass, gray glass, etc. It is known to use glass, and in recent years, greenish colored glass has been adopted for vehicles and the like. However, in these heat ray absorbing glasses, the absorbed solar radiation is converted into heat, and is again radiated as heat rays (far infrared rays) not only outdoors but outside the vehicle as well as inside and inside the vehicle.

Further, regarding a glass having a heat-shielding film formed on a colored heat ray absorbing glass, Japanese Patent Laid-Open No. 4898/1985 discloses a panel which transmits at least a part of visible light, for example, a colored heat ray absorbing glass. , Borides, carbides, nitrides, oxides (metalloids) of elements belonging to a specific group of the Periodic Table
A sunlight filter heat insulating glass having a film formed thereon is disclosed, and in Japanese Utility Model Publication No. 3-55832, a gray heat absorbing glass is sequentially laminated with a chromium nitride film and a transparent oxide film, or a bronze heat absorbing glass. It is known that a heat-shielding film is simply formed on a colored heat-absorbing glass, such as the heat-shielding glass in which similar films are laminated.

However, it does not disclose a combination of a heat ray / ultraviolet ray absorbing green glass that effectively blocks solar radiation and a low emissivity film that effectively reflects far infrared rays having high heat energy. It is hard to say that metalloid films and the like are suitable from the viewpoint of low radiation.

Regarding the multi-layer glass (double glass) using the colored heat ray absorbing glass, the heat insulating property is designed by designing the colored heat ray absorbing glass on the outdoor side and the ordinary glass on the indoor side. It is known to improve,
In the Japanese Patent Application No. 2-321465, Japanese Patent Application No. 2-405840, etc. according to the applicant's earlier invention, among others, a greenish colored (heat ray absorbing) glass is proposed, and a laminated glass using the glass,
It is already known technical matter such as disclosing and suggesting the double glazing.

Further, regarding a double glazing composed of a colored glass-glass combination in which at least one of the glasses is provided with a heat-shielding film, US Pat. Bronze color glass, heat ray absorbing glass such as gray glass is arranged, an infrared reflection film made of tin oxide is filmed on the inner surface thereof, and a heat ray reflecting window in which ordinary glass is arranged on the indoor side is disclosed. U.S. Pat.No.4687687 discloses a double glazing unit incorporating two coatings, one coating being a low emissivity coating with doped tin oxide and / or doped indium oxide and the other coating. The film shall be a heat-reflecting metal oxide containing at least 30 wt% tin and at least 30 wt% titanium in terms of dioxide, and one of the glass plates shall be body colored glass. DOO proposed that can, for example, the outer bronze colored glass having a heat reflecting metal oxide coating on the outer surface, the double glazing unit consisting of an inner glass having a low emissivity coating on the inner surface side is disclosed.

However, it is not disclosed and suggested to dispose the heat ray / ultraviolet absorbing green glass on the outer glass and to form the low emissivity film including the silver layer on the inner surface as in the present invention.

JP-A-1-105895 describes a double glass consisting of an outer colored glass for absorbing heat rays such as green and bronze and an inner annealed glass, and the inner surface of the inner glass (the surface facing the outer glass). It is disclosed to have a coating containing a silver layer of 15-40 nm. Although the coating including the silver layer exhibits a low radiation effect, the one having the low radiation film disposed on the inner surface of the inner glass has a heat shield more than the one disposed on the inner surface of the outer glass as exemplified in the section of the later-mentioned Examples. , Inferior in heat insulation.

That is, these known examples do not disclose the constitution as in the present invention, and although the constitution is simple, it is inferior in heat shield and heat insulation, and it is difficult to effectively shield harmful ultraviolet rays, or heat shield. Although the heat insulation has a proper function, it has a drawback that the structure is complicated, the lighting and the transparency are impaired, the cost is extremely high, and it is generally difficult to use. The present invention has a simple structure, has a color tone that is visually gentle and matches the green color of vegetation, absorbs heat rays from solar radiation, and is based on heat ray / ultraviolet ray absorbing green glass that acts to block harmful ultraviolet rays, In particular, by providing a low-emissivity film that blocks heat rays in the far infrared region, a heat-shielding glass that improves the heat-shielding effect without impairing daylighting and transparency, and a double-layer glass using the same are provided. To do.

[0010]

SUMMARY OF THE INVENTION The present invention relates to a heat-shielding glass, which is a heat-ray / ultraviolet-absorbing green glass formed on one surface with a multilayer film including a silver layer and having a low emissivity film having a vertical emissivity of 0.2 or less. The heat ray / ultraviolet absorbing green glass has a visible light transmittance of 65% or more (A light source) at a plate thickness of 5 mm, a solar radiation transmittance of 35 to 50%, an ultraviolet transmittance of 15% or less, a main wavelength of 500 to 530 nm, and a stimulus. It is a multi-layer glass having a purity of 5 or less, further, the heat-shielding glass is arranged on the outdoor side and a clear glass is arranged on the indoor side, and a low-emissivity film is formed on the inner surface of the heat-shielding glass. Consists of.

As a glass that matches the characteristics of the heat ray / ultraviolet absorbing green glass, Japanese Patent Application Nos. 2-321465, 2-405840, and 3-1449 according to the invention of the present applicant.
The glass proposed in No. 27, etc. can be preferably used. All of these are soda-lime-silica type glasses, and Fe ₂ O ₃ 0.58 to 0.75 wt% and CeO ₂ 0.15% as coloring components in total.
0 to 0.50 wt%, TiO ₂ 0.10 to 0.40 wt% in the range, and MnO is contained in an appropriate amount at 300 ppm or less, those having this composition range as Central Glass Co., Ltd. product name Greenral SP It is commercially available.

[0012] In addition, Japanese Patent Application No. 5-24456 of the applicant of the present invention discloses that in soda lime silica glass, Fe ₂ O ₃ (total iron) 0.1 to 0.3 wt% as a coloring component,
We proposed a greenish glass containing CoO 20 to 50 ppm and Cr ₂ O ₃ 200 to 400 ppm and a reduction rate (Fe ²⁺ / Fe ³⁺ ) of 20 to 50%, but based on this, within the range that does not impair the color tone. Glass to which TiO ₂ , CeO ₂ or the like is appropriately added can also be used.

The low-emissivity film in the present invention has a tendency to easily transmit visible light, but to reflect near-infrared light to far-infrared light, particularly light in the far-infrared region having a wavelength of 2100 nm or more. Heat (far-infrared rays) from the human body and other objects
It reduces the heat dissipation in the room and thus reduces the indoor heating load in winter. Also, since it suppresses the incidence of sunlight in the infrared region into the indoor, it reduces the indoor cooling load in summer, but rather, its action is significantly improved by combining it with heat ray / ultraviolet absorbing green glass. It is a thing.

The low-emissivity film is best if it includes a metal layer, especially a silver layer, in consideration of cost and performance, however, in consideration of adhesiveness with glass, stability to atmosphere, and corrosion resistance, metal oxide is used. It is preferable that the basic film structure is a physical layer-silver layer-metal oxide layer. By way of example, scissors ZnO -Ag-ZnO, or this Au, Al, Pt, Cr and other metal layers as appropriate, TiO _2, SiO ₂ and other metal oxide layer as appropriate inner layer, intermediate layer, or outer layer It is good to arrange as. Note that the low emissivity film usually has a vertical emissivity of 0.3 to 0.4 or less according to the measurement method specified in JIS R 3106, but in the present invention, the emissivity is sufficiently exhibited by setting it to 0.2 or less, and it is more preferable. Is preferably 0.1 or less.

The double glazing in the present invention is based on arranging a heat ray / ultraviolet absorbing green glass on the outside glass, arranging a low emissive film on the inside thereof, and arranging a clear glass on the inside glass. The clear glass includes light-colored glass, glass with a wire rod, clear glass with a non-coloring transparent film, and the like. In addition, it is not preferable to dispose a colored heat ray absorbing glass similar to or different from the outer glass on the inner glass, because the transparency may be impaired. Also, it is effective for heat insulation to dispose the low emissivity film inside the outer glass.

The thickness of each glass and the space thickness (width) between the glasses in the double glazing are not specified, but for example, glass thickness 3 mm-space 6 mm-glass thickness 3 mm, or glass thickness 3 mm-space 12 mm. -The most common arrangement is a glass thickness of 3 mm. Of course, the thickness of the glass and the width of the space can be appropriately designed, and it is also possible to use multi-layered glass with three or more layers, to use one or both of the glasses as tempered glass or semi-tempered glass, and to see through the inner glass surface with remarkable transparency. It is also an appropriate design matter to coat a functional film such as a low-emissivity film or a heat ray reflective film within a range not impairing, and to enclose various adiabatic gases other than air in the internal space.

The heat-shielding glass having the constitution of the present invention, in particular, the double glazing using the same is excellent in heat-shielding property, heat-insulating property, and ultraviolet-shielding property, and of course, has appropriate lighting and see-through properties, and is of a greenish type. Therefore, it has various effects such as giving a visually gentle feeling.

[0018]

EXAMPLES The present invention will be described below with reference to several examples.
FIG. 1A is a graph showing the transmittance of the glass used in this example and the comparative example, which is measured by a spectrophotometer, where a is an ultraviolet ray manufactured by Central Glass Co., Ltd.
Infrared absorbing green glass, trade name Green Ral SP, b is bronze glass manufactured by Central Glass Co., Ltd., product name Bronze Ral, c is blue glass manufactured by Central Glass Co., Ltd., product name Blue Ral, d is clear manufactured by Central Glass Co., Ltd. The transmittance curves of glass and float glass (FL) with a thickness of 3 mm are shown.

FIG. 1B is a graph showing the reflectance (measured from the glass surface side of a film having a thickness of 3 mm clear glass) of the low-emissivity film and the heat ray reflective film used in this example and comparative examples. It was measured by similar means,
In the figure, e is a low emissivity film with a vertical emissivity of 0.07, and f is a vertical emissivity.
The low emissivity film of 0.16, g shows the reflectance curve of the heat ray reflective film having a vertical emissivity of 0.36. In addition, the heat ray reflective film has a tendency to reflect solar radiation in the visible light to near infrared region as shown in the figure,
On the other hand, the reflection of heat rays in the far infrared region is not as strong as that of the low emissivity film,
On the other hand, the low-emissivity film is distinguished by the fact that it easily transmits visible light and selectively reflects far infrared rays strongly.

[I] Heat-shielding glass [Example A] Heat ray / ultraviolet absorbing green glass (thickness: 3 mm)
On one surface of (1), a low-emissivity film having a total film thickness of 880 A and having a vertical emissivity of 0.07 according to the measuring method specified in JIS R 3106 was formed by alternately sputtering ZnO and Ag. This film-coated glass was measured according to JIS R 3106 by the visible light transmittance by A light source, visible light reflectance, solar radiation transmittance, solar radiation reflectance (outer glass surface only), solar radiation absorptivity, UV blocking rate, The heat transmission coefficient, the shielding coefficient, and the solar heat gain coefficient were measured. The results are shown in Table 1.

[Example B] The same heat ray / ultraviolet absorbing green glass (thickness 3 mm) as in Example A was formed on one surface by sputtering, and the inner and outer layers were made of SiNx, and the metal layers sandwiched between them were made of Ag and Ni-Cr. And a low emissivity film having a total film thickness of 920 A and a vertical emissivity of 0.16 was applied. In the same manner as in Example A, the visible light transmittance, visible light reflectance, solar radiation transmittance, solar radiation reflectance, solar radiation absorptivity, ultraviolet ray blocking ratio, heat transmission coefficient, shielding coefficient, and solar heat gain coefficient were measured. The results are shown in Table 1.

[Comparative Example A] Bronze glass (thickness 3 m
m), Fe-Ni-Cr (stainless steel) and TiNx
The total film thickness is 480A and the vertical emissivity is 0.36
The heat ray reflective film made of was deposited by the sputtering method. In the same manner as in Example A, the visible light transmittance, visible light reflectance, solar radiation transmittance, solar radiation reflectance, solar radiation absorptivity, ultraviolet ray blocking rate, heat transmission coefficient, shielding coefficient, and solar heat gain rate were measured. The results are shown in Table 1.

Comparative Example B The same vertical emissivity as in Example A was applied to the same bronze colored glass (thickness 3 mm) as in Comparative Example A.
A 0.07 low emissivity film was applied. In the same manner as in Example A, the visible light transmittance, visible light reflectance, solar radiation transmittance, solar radiation reflectance, solar radiation absorptivity, ultraviolet ray blocking rate, heat transmission coefficient, shielding coefficient, and solar heat gain rate were measured. The results are shown in Table 1.

[Comparative Example C] On a blue glass (thickness: 3 mm),
A low emissivity film having a vertical emissivity of 0.07, which is exactly the same as that of Example A, was applied. In the same manner as in Example A, the visible light transmittance, visible light reflectance, solar radiation transmittance, solar radiation reflectance, solar radiation absorptivity, ultraviolet ray blocking rate, heat transmission coefficient, shielding coefficient, and solar heat gain rate were measured. The results are shown in Table 1.

[Comparative Example D] Clear glass (thickness 3 mm)
Then, a low-emissivity film having a vertical emissivity of 0.07, which is exactly the same as in Example A, was applied. Similar to Example A, this is the visible light transmittance,
Visible light reflectance, solar radiation transmittance, solar reflectance, solar absorption,
The ultraviolet ray blocking rate, heat transmission coefficient, shielding coefficient, and solar heat gain coefficient were measured. The results are shown in Table 1.

[0026]

[Table 1]

As is clear from the results shown in Table 1, the heat-shielding glasses of Examples A and B according to the present invention have a visible light transmittance of 66% or more and an ultraviolet light shielding rate of 85% or more, and particularly, the solar heat acquisition. With a ratio of 0.50 or less, it has good transparency and excellent shielding from ultraviolet rays and solar heat. For example, the thickness of glass is 3 mm to 6 mm.
However, since the visible light transmittance is well above 50%, the transparency is not impaired, and the ultraviolet and solar heat shielding properties are improved, which is a more preferable embodiment. The low emissivity film may have a vertical emissivity of 0.20 or less, but a value of 0.10 or less is recommended because it further improves the solar heat shielding property.

Comparative Example A had a visible light transmittance of less than 10% and almost no function as a window material, and Comparative Examples B to D had a solar heat gain of 0.52 or more. Obviously inferior to the example.

[II] Double-layered glass [Example 1] The heat-shielding glass (heat ray with film / UV absorbing green-based glass: thickness 3 mm) used in the above-mentioned Example A was used as the outer glass and had a low vertical emissivity of 0.07. A radioactive film is placed on the inner surface, and clear glass (thickness 3
mm) as the inner glass,
In the same manner as in Example A, the visible light transmittance, visible light reflectance, solar radiation transmittance, solar radiation reflectance, solar radiation absorptivity, ultraviolet ray blocking ratio, heat transmission coefficient, shielding coefficient, and solar heat gain coefficient were measured. The results are shown in Table 2.

Example 2 The same as in Example 1, except that a double glazing having an air space of 12 mm was prepared, and in the same manner as in Example 1, visible light transmittance, visible light reflectance, solar radiation transmittance, solar radiation The reflectance, the solar radiation absorptance, the ultraviolet ray blocking rate, the heat transmission coefficient, the shielding coefficient, and the solar heat gain rate were measured. The results are shown in Table 2.

Example 3 The same procedure as in Example 1 was repeated, except that a double-layer glass in which a space (6 mm) was filled with argon gas was prepared, and the visible light transmittance, visible light reflectance, and
Solar transmittance, solar reflectance, solar absorption, UV blocking rate,
The heat transmission coefficient, the shielding coefficient, and the solar heat gain coefficient were measured. The results are shown in Table 2.

[Embodiment 4] The heat-shielding glass used in the above-mentioned embodiment B (heat ray with film / green glass absorbing ultraviolet rays: thickness 3)
(mm) as the outer glass, a low emissivity film with a vertical emissivity of 0.16 is placed on the inner surface, and clear glass is provided through the air space (6 mm).
A multi-layer glass in which (thickness: 3 mm) was disposed as an inner glass was prepared, and in the same manner as in Example 1, visible light transmittance, visible light reflectance, solar radiation transmittance, solar radiation reflectance, solar radiation absorptivity, ultraviolet ray blocking rate, The heat transmission coefficient, the shielding coefficient, and the solar heat gain coefficient were measured. The results are shown in Table 2.

[Embodiment 5] The heat-shielding glass used in the above-mentioned Embodiment A (heat ray with film / UV absorbing green glass: thickness 3)
mm) as the outer glass and a low emissivity film with a vertical emissivity of 0.07 on the inner surface, and the heat-shielding glass (clear glass with film: thickness 3 mm) used in Comparative Example D through the air space (6 mm) as the inner glass As a double-layered glass having a low emissivity film with a vertical emissivity of 0.07 on its inner surface, as in Example 1, visible light transmittance, visible light reflectance, solar radiation transmittance, solar radiation reflectance, solar radiation absorptivity, The ultraviolet ray blocking rate, heat transmission coefficient, shielding coefficient, and solar heat gain coefficient were measured. The results are shown in Table 2.

Comparative Example 1 The heat-shielding glass (bronze colored glass with a film: thickness 3 mm) used in the above-mentioned Comparative Example A was used as an outer glass, and a heat-reflecting film having a vertical emissivity of 0.36 was arranged on the inner surface, and air was blown. Clear glass through the space (6 mm): thickness 3
mm) as the inner glass,
In the same manner as in Example 1, the visible light transmittance, visible light reflectance, solar radiation transmittance, solar radiation reflectance, solar radiation absorptivity, ultraviolet ray blocking rate, heat transmission coefficient, shielding coefficient, and solar heat gain rate were measured. The results are shown in Table 2.

[Comparative Example 2] The heat-shielding glass (bronze colored glass with a film: thickness 3 mm) used in Comparative Example B was used as an outer glass, and a low emissivity film having a vertical emissivity of 0.07 was arranged on the inner surface, and an air space (6 mm ) And a clear glass (thickness: 3 mm) as an inner glass, a double-layer glass was prepared, and Example 1
Similarly, the visible light transmittance, the visible light reflectance, the solar radiation transmittance, the solar radiation reflectance, the solar radiation absorption rate, the ultraviolet ray blocking rate, the heat transmission coefficient, the shielding coefficient, and the solar heat gain rate were measured. The results are shown in Table 2.

Comparative Example 3 The heat-shielding glass (blue glass with film: thickness 3 mm) used in Comparative Example C was used as the outer glass.
A low emissivity film with a vertical emissivity of 0.07 is placed on the inner surface to create an air space.
A multilayer glass in which clear glass (thickness 3 mm) was provided as an inner glass via (6 mm) was prepared, and as in Example 1, visible light transmittance, visible light reflectance, solar radiation transmittance, solar radiation reflectance, The solar absorptance, the UV blocking rate, the heat transmission rate, the screening coefficient, and the solar heat gain rate were measured. The results are shown in Table 2.

[Comparative Example 4] The heat-shielding glass (clear glass with a film: thickness 3 mm) used in Comparative Example D was used as an outer glass, and a low emissivity film having a vertical emissivity of 0.07 was arranged on the inner side surface to form an air space (6 mm). A multilayer glass in which clear glass (thickness: 3 mm) is disposed as an inner glass through the glass is prepared, and in the same manner as in Example 1, visible light transmittance, visible light reflectance, solar radiation transmittance, solar radiation reflectance, solar radiation absorption rate. The UV blocking rate, the heat transmission rate, the blocking coefficient, and the solar heat gain rate were measured. The results are shown in Table 2.

Reference Example 1 The same heat ray / ultraviolet absorbing green glass (thickness 3 mm) as the glass adopted in Example A was used as the outside glass without filming, and Comparative Example D was placed through the air space (6 mm). The heat-shielding glass (clear glass with film: thickness 3 mm) used in 1. was used as the inner glass, and a low-emissivity film with a vertical emissivity of 0.07 was arranged on the inner surface to prepare a double-layer glass. The light transmittance, the visible light reflectance, the solar radiation transmittance, the solar radiation reflectance, the solar radiation absorption rate, the ultraviolet ray blocking rate, the heat transmission coefficient, the shielding coefficient, and the solar heat gain rate were measured. The results are shown in Table 2.

[Reference Example 2] A multilayer glass similar to that of Reference Example 1 was prepared except that the air space was 12 mm, and the visible light transmittance, the visible light reflectance, the solar radiation transmittance and the solar radiation were the same as in Example 1. The reflectance, the solar radiation absorptance, the ultraviolet ray blocking rate, the heat transmission coefficient, the shielding coefficient, and the solar heat gain rate were measured. The results are shown in Table 2.

[0040]

[Table 2]

As is clear from Table 2, the double glazings of Examples 1 to 4 according to the present invention have a visible light transmittance of 60% or more, an ultraviolet ray blocking ratio of 90% or more, and a solar heat gain ratio of 0.45 or less, which are suitable for visible light. Shows light transparency, ultraviolet rays, and solar heat shielding properties, and if the vertical emissivity of 0.10 or less is adopted as in Examples 1 to 3, it exhibits a solar radiation shielding property of around 0.40, which is extremely desirable. . Of course, the thickness of the heat-shielding glass is used as an example.
If 3 mm of 1 to 3 is changed to about 6 mm, the ability to block ultraviolet rays and solar radiation can be further improved without significantly impairing the transparency.

The visible light transmittance of Example 5 is in the order of 50%, which is inferior to that of Examples 1 to 4, but does not significantly impair the transparency, and the ultraviolet ray blocking rate is 97% or more and the solar heat gain rate is less than 0.40. Shows the best value.

From the viewpoint of energy saving in recent years, the solar heat gain rate
0.4 order is recommended, and in particular, there are many cases where the customer demands a value around 0.4 or less, but Examples 1 to 5 according to the present invention sufficiently satisfy that.

In Comparative Example 1, the visible light transmittance was less than 10%, and the function as a window material was almost lost. In Comparative Examples 2 to 4, the ultraviolet ray blocking rate was not high, and the solar heat gain rate exceeded 0.45. Obviously, it is inferior to the examples.

The reference examples 1 and 2 are different from the examples 1 and 2 in that the arrangement of the low emissivity film is changed and the inner glass is arranged. Slightly inferior to No. 2, it is clear that the embodiment according to the present invention is the best arrangement configuration.

[0046]

EFFECTS OF THE INVENTION According to the present invention, the heat-shielding glass has a visually mild color tone that matches the green color of vegetation, absorbs heat rays from solar radiation, and has a function of blocking harmful ultraviolet rays. By forming a low-emissivity film that blocks heat rays in the far infrared region on the basis of greenish glass, the heat-shielding effect is improved and, of course, light and transparency are not impaired. In addition, the double glazing using the same has an effect of improving the ultraviolet ray blocking rate and being significantly excellent in heat blocking property and heat insulating property.

[Brief description of drawings]

FIG. 1A is a graph showing the transmittance of ultraviolet / infrared absorbing green glass, bronze glass, blue glass, and clear glass. FIG. 1B is a graph showing the reflectance of the low emissivity film and the heat ray reflective film.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Shoji Onishi 1510 Oguchi-cho, Matsusaka-shi, Mie Central Glass Co., Ltd. Technical Center

Claims (3)

[Claims] 1. A heat-ray / ultraviolet-absorbing green glass on one side,
A heat-shielding glass comprising a multi-layer film including a silver layer and having a low emissivity film having a vertical emissivity of 0.2 or less. 2. The heat ray / ultraviolet absorbing green glass has a plate thickness of 5
mm visible light transmittance (A light source) 65% or more, solar radiation transmittance 35 to 50%, ultraviolet light transmittance 15% or less, dominant wavelength 500 to 530n
The heat-shielding glass according to claim 1, wherein m 2 and stimulus purity are 5 or less. 3. A multi-layer glass comprising the heat-shielding glass according to claim 1 or 2 on the outdoor side and a clear glass on the indoor side, wherein the low emissivity film is formed on the inner surface of the heat-shielding glass. Multi-layer glass using a heat-shielding glass characterized by.