JPH07315889A - Heat shielding glass and its composite material - Google Patents

Abstract

PURPOSE:To produce a heat shielding glass capable of exhibiting a solar radiation screening effect without reducing the transmittance of visible light so remarkably as to cause an obstruct in practical use by making up it from a glass base and a coating film formed on one of the main surfaces. CONSTITUTION:This heat shielding glass is composed of a glass base 1 and a coating film 2 formed on one of the main surfaces 4 and the coating film 2 side is directed toward the room in practical use. The glass base 1 is composed of a colorless soda-lime glass having >=8mm thickness or a soda-lime silica glass containing a very small amount of a coloring agent and having >=8mm thickness and has >=55% transmittance of visible light and >=15% absorbance of solar radiation. The coating film 2 has <=0.3 vertical emissivity. In order to realize this emissivity value, the surface resistance value of this coating film is controlled to <= about 40OMEGA/cm<2> and the coating film is composed of a multi-layer film containing a conductive film of Ag, Al, etc., or a single layer film containing a conductive oxide as the main components. The heat shielding glass is designed so as to have a visible light transmittance value higher than 50% and higher than the take-up of the solar radiation heat from the outdoor, <=70% take-up of the solar radiation heat from the outdoor and <=10% reflectance of visible light from the coating film side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat ray shielding glass which is effective in reducing the inflow of solar energy into the internal space of a building or the like, and particularly in reducing the cooling load in the summer.

[0002]

2. Description of the Related Art Conventionally, as a glass for reducing the inflow of solar energy into a room, a metal (Cr, Ti, SUS, etc.) or a metal (Cr, T) having a high reflectance on the glass surface is used.
i, SUS, etc.) Nitride, metal (Cr, Ti, SUS, etc.)
A so-called heat ray-reflecting glass is generally known in which a thin film containing an oxynitride or the like is coated, and the thin film reflects visible light or near-infrared light which occupies most of the solar energy. Further, a so-called heat ray absorbing glass in which a very small amount of a coloring component is added to the glass and the solar energy is absorbed in the glass itself is generally known.

[0003]

However, the conventional heat-ray-reflecting glass or heat-absorbing glass which simply reflects or absorbs visible light or near-infrared light, which occupies most of the solar radiation energy, is a building of solar energy. Although it is possible to reduce a certain amount of inflow into the internal space, the transmittance of the visible light portion of the sunlight spectrum is also considerably reduced, which leads to unfavorable results such as darkening the room and impairing comfort.

It is an object of the present invention to provide a heat ray shielding glass which solves the above-mentioned conventional problems while reducing the inflow of solar energy.

[0005]

A heat ray-shielding glass according to the present invention comprises a glass substrate and a coating film formed on one of its main surfaces, and has a visible light transmittance of 55% or more and a solar radiation absorptivity. Is 15% or more and the vertical emissivity of the coating is 0.3 or less, and the solar light has a visible light transmittance of 50% or more and is incident from a main surface opposite to the main surface on which the coating is formed. It is characterized in that the acquisition rate is not less than 70% and the solar heat acquisition rate is not less than 70%.

Here, the main surface of the glass substrate means the main surface of the glass substrate 1, and the surfaces 3 and 4 located on the front surface or the back surface when the glass substrate 1 is seen in a plan view.

The glass substrate has a visible light transmittance of 55.
%, And if the solar radiation absorption rate is 15% or more, it can be used without particular limitation, but in the case of colorless soda lime silica glass generally used for buildings etc., it is shown in Table 1. As described above, the solar radiation absorption rate is 15% or more when the thickness is 8 mm or more. However, in the case of soda lime silica glass (colored transparent heat ray absorbing glass colored in blue, gray, bronze, green, etc.) that has been added with a minute amount of coloring components to enhance the effect of solar radiation, even if the thickness is less than 8 mm The absorptivity is 15% or more (for example, the visible light transmittance of "Gray Pane" (trade name of Nippon Sheet Glass) having a thickness of 3 mm is 72.4%, and the solar absorptivity is 18.
5%. ), There are some that can be used in the present invention. In addition, as shown in Table 1 together, soda lime silica glass having a fireproof property with a net or a wire can also be used as the glass substrate of the present invention.

[0008]

[Table 1]

The vertical emissivity of the coating that can be used in the present invention is 0.3 or less.
The surface resistance of the coating may be about 40 Ω / square or less. For example, from a multilayer film including a conductive coating film containing at least one of Ag, Au, Cu, and Al as a main component, a single-layer film containing a conductive oxide as a main component, or a multilayer film including the single-layer film. Can be used.

The heat ray-shielding glass according to the present invention may be used as a glass composite such as a double-glazing or laminated glass. That is, a plurality of glass plates including the heat-shielding glass according to the present invention that are adjacent to each other are airtightly sealed around the periphery of these glass plates in a state where they are separated from each other to secure an air layer It is also possible to use a laminated glass or a heat ray-shielding laminated glass in which a plurality of glass sheets including the heat ray-shielding glass according to the present invention are bonded and integrated by a plastic intermediate film arranged on the joint surface between these glass sheets.

Alternatively, a coating having a vertical emissivity of 0.3 or less is formed on at least one of the main surfaces of the plurality of glass plates, and the outermost main surface of the double glazing or laminated glass. 15% or more of the solar energy incident from any one of the above will be absorbed by the glass plate constituting the multi-layer glass or the like until it reaches any one of the main surfaces on which the coating is formed, and the coating is not formed. When the visible light transmittance of the glass composite in the state is 55% or more, the visible light transmittance is 50% or more, and the solar heat gain rate or more for the incident from the same direction as the solar energy and the solar heat gain rate. May be 70% or less, and may be heat-ray shielding laminated glass, heat-ray shielding laminated glass, or the like.

As the plastic intermediate film,
For example, PVB (polyvinyl butyral) can be used. Further, in the heat ray-shielding laminated glass using the intermediate film such as PVB, it is preferable that the coating film is formed not on the main surface in contact with the intermediate film 10 but on the main surface 34 in contact with the atmosphere as shown in FIG. That is, in the heat ray-shielding glass composite according to the present invention, generally, the main surface forming the coating film is the main surface in contact with the air layer, which is a condition for achieving the following effects of the present invention.

The heat ray-shielding glass according to the present invention has its characteristics by being installed in an opening of a building or the like with the main surface on which the film is formed being indoors (the main surface without the film being being outdoors). It will be a heat-shielding glass window that makes good use of it. Similarly, for heat ray shielding double glazing, heat ray laminated glass, etc., the characteristics of the main surface formed with a coating having the following functions of the present invention are set in an opening of a building or the like so that the main surface faces the indoor direction. A heat ray-shielding glass composite window such as a heat ray-shielding laminated glass window or a heat ray-shielding laminated glass window is utilized.

[0014]

The heat-shielding glass according to the present invention is capable of absorbing solar radiation energy absorbed in the glass and re-radiated by a coating having a low vertical emissivity formed on one of the main surfaces of the glass. In order to facilitate the re-radiation of solar radiation energy only to the other glass main surface direction by suppressing the re-radiation of the glass, use a glass substrate that forms a film that has the characteristic of absorbing solar radiation energy above a certain level. Thus, the effect of increasing the contribution of the coating film to the heat ray shielding effect is exerted.

Further, the heat ray-shielding glass according to the present invention shifts the wavelength range of energy re-radiated from the glass to the longer wavelength side than the wavelength range of the sunlight absorbed by the glass and shifts the visible light range as a whole. By utilizing the fact that they are further apart, the solar radiation energy absorbed by a predetermined amount or more and shifted to the long wavelength side and re-emitted is reflected by a coating having a vertical emissivity of a predetermined value or less to obtain the solar heat gain rate. Even if it is reduced, it is possible to suppress the decrease in visible light transmittance as compared with the conventional heat ray reflective glass in which the coating film directly and directly reflects the solar energy in the visible light region or the near infrared region. It plays.

Further, when a colorless soda lime silica glass is used as the glass substrate of the heat ray shielding glass according to the present invention, a more preferable result can be obtained by using a glass having a thickness of a certain value or more. That is, in the spectral transmittance curve of soda lime silica glass, as shown in FIG. 6, the transmittance particularly in the near infrared region of about 1 μm decreases. Therefore, the degree of increase in the solar energy absorbed by the glass as the thickness increases becomes greater than the degree of increase in visible light absorption. For example, the thickness is 3mm
From 8 mm to 8 mm, the increase in visible light absorption is about 2.7%, while the increase in solar radiation absorption is about 9.7.
%. As described above, the heat ray-shielding glass according to the present invention can also utilize the above-mentioned characteristics of soda lime silica glass having a thickness of a certain value or more.

Further, the heat ray-shielding glass according to the present invention is often required for a building or the like having heat insulating property, safety, soundproofing property, and ultraviolet ray shielding property by utilizing it as so-called double glazing or laminated glass. It can also have various functions.

In the so-called glass composites such as these double glazings, two or more glass plates constituting the glass composites are provided under the condition that the solar radiation acquisition rate of the glass substrate of the present invention is 15% or more. Should meet this condition together. For example, as shown in FIG. 3, two glass plates 1
The coating 2 having the above-mentioned low emissivity is formed on one outermost main surface 14 of the double glazing composed of a, 1b, the spacer 8 and the sealant 9, and the outermost main surface on which the coating is formed is formed into a chamber. When used on the inside, the solar energy incident from the outside reaches the coating film 2 through the two glass plates 1a and 1b.
If the total solar absorptance of a and 1b is 15% or more, this double glazing can exert the above-mentioned effect of the present invention. Therefore, when colorless soda lime silica glass is used for the heat ray-shielding glass composite according to the present invention, it is not necessarily a condition that the glass composite having a thickness of 8 mm or more is used in combination.

[0019]

EXAMPLES The present invention will be described in detail below with reference to examples and comparative examples. Example 1 A base dielectric film, an Ag alloy film or an Ag film, and a protective dielectric film were formed in this order on a colorless soda lime silica glass manufactured by a float manufacturing method with a thickness of 15 mm by using a DC magnetron sputtering method. Formed. ITO was used as the base dielectric, an oxide sintered target was used for the film formation, and the film was formed in an Ar atmosphere containing oxygen. The Ag alloy film was formed by using an alloy target containing 15 mol% of Pd or a target of Ag alone. As the protective dielectric film, reactive sputtering with oxygen was performed using a Sn metal target to form a tin oxide film. The film thickness of each coating is, as shown in Table 2, roughly, AgP
The d film or the Ag film had a thickness of 3 to 20 nm, and the ITO film and the tin oxide film had a thickness of 10 to 60 nm. The spectral transmittance and the spectral reflectance of the formed sample were measured, and the solar transmittance, the solar absorptivity, etc. were calculated from them. In addition, the infrared spectral reflectance was measured to calculate the hemispherical emissivity. The results are summarized in Table 2 (Examples 1-1 to 1-9).

[0020]

[Table 2]

(Comparative Example) The same thickness as the above-mentioned Example 15 mm
The metal (Cr, SU) usually used as a material with high reflectance on the surface of colorless soda lime silica glass
A thin film containing S) and a metal (Ti) nitride was formed by a DC magnetron sputtering method. The film thickness of each layer was adjusted so that the visible light transmittance was 60% to 70%. The spectral transmittance and the spectral reflectance of the obtained sample were measured, and the solar transmittance, the solar absorptivity, etc. were calculated from them. In addition, the infrared spectral reflectance was measured to calculate the hemispherical emissivity. The results are summarized in Table 2 (Comparative Examples 1 to 4). The measured values in the above-mentioned Examples and Comparative Examples relate to the characteristics with respect to the incidence of visible light or solar radiation from the outside of the room, with the main surface on which the film is formed as the indoor side.

In Table 2, when the characteristics are compared between the example and the comparative example having the same visible light transmittance, the measured value of the solar heat gain rate in the example is reduced by about 10%.

In Table 2, the visible light transmittance is 50% or more and the solar heat gain coefficient is 70% or less (60% or less except for Examples 1-8) in all Examples, and the visible light transmission is The rate is higher than the solar heat gain rate. Moreover, about Example 1-1-Example 1-5, a solar radiation heat acquisition rate is 55.
% Or less, and in Examples 1-6 to 1-9, the visible light transmittance is 65% or more.

On the other hand, in Comparative Examples 1 to 4, the visible light transmittance was lower than the solar heat gain coefficient, and only the glass substrate (colorless soda lime silica glass having a thickness of 15 mm) was used as a comparative example. In No. 5, the solar heat gain rate exceeds 70%.

The solar heat gain rate η, which indicates the degree of penetration of solar energy into the room, can be evaluated by the following formula defined in JISR 3106.

[0026]

[Formula 1]

Here, the hemispherical emissivity of the glass surface is about 0.8.
It is 4. On the coated surface, the vertical emissivity is almost equal to the hemispherical emissivity, and the vertical emissivity on the glass surface is about 0.8.
It is 9.

As described above, the film that can be used in the present invention may have a surface resistance of about 40 Ω / square or less.
In addition to those shown in the above-mentioned examples, for example, a coating film containing tin oxide as a main component and having a thickness of about several hundreds nm may be used. This coating can be continuously formed by the so-called thermal CVD method on the glass manufacturing line by the float method,
It is also preferable in terms of productivity and excellent in durability. Even if the film is mainly composed of zinc oxide or ITO, the surface resistance value is 4
It can be set to 0 Ω / square or less.

Regarding the film durability, in Examples 1-1 to 1-8 of Example 1 described above, Pd was added to the Ag film to improve the durability of the Ag film, and the glass single film to which the film was exposed was exposed. It will be prepared for use as a board.

The element added to the Ag film for improving the film durability is not limited to Pd, but Pt, Sn, Zn, In, Cr,
Ti, Si, Zr, Nb, Ta, etc. can be used. That is, Pd, Pt, Sn, Zn, In, Cr,
By adding at least one element from the group consisting of Ti, Si, Zr, Nb, and Ta in a molar ratio of 5 to 20% to form an alloy, the aggregation of Ag is suppressed and the continuity of the Ag film is maintained. The coating durability is improved.

Further, from the viewpoint of improving the film durability, the underlying dielectric film is preferably a polycrystalline film. Specifically, besides ITO, ZnO, In ₂ O ₃ , Y ₂ O ₃ etc. Can be used. Further, from the same viewpoint, the protective dielectric film is preferably an amorphous body, and specifically,
_{SnO X, TaO X, TiO X} , ZrB X O Y, SiO
_X , SiN _X , SiN _X O _Y (where _XY indicates that the case of a non-stoichiometric ratio is included) and the like can be used.

By the way, with respect to the heat ray reflective glass having the glass surface coated with a film having a high reflectance, the sunlight reflected in the daytime may cause a reflected light obstacle in the vicinity of the building, so that the interior lighting at night. Therefore, there is also a problem that the glass acts like a mirror and tends to cause discomfort.

In this respect, the coating used in the present invention does not need to have a high reflectance in the visible light region or the near-infrared region, and a low emissivity is sufficient, so that the reflectance of the main surface on which the coating is formed is reduced. It is possible to keep it low. For example, in Example 1-2 and Examples 1-4 to 1-9, the reflectance of the glass surface on which the coating is formed (the visible light reflectance on the indoor side) is suppressed to 10% or less. Furthermore, in Example 1-2 and Example 1-4 to Example 1-9, the reflectance of the glass surface on which the coating was formed (visible light reflectance on the indoor side) was suppressed to 6% or less. It is lower than the reflectance of the plate alone, and has a so-called antireflection effect.

In the first embodiment, the outdoor visible light reflectance (visible light reflectance on the main surface side on which no coating is formed)
Is also 12% or less, which is suppressed to such an extent that no trouble is caused by reflected light.

Example 2 A 200 nm thick tin oxide film doped with fluorine was formed on a colorless float glass having a plate thickness of 15 mm by a thermal CVD method through a thin underlayer. The value of the sheet resistance of the film was about 20 Ω / square. The visible light transmittance and solar heat gain of this glass were measured in the same manner as in Example 1, and were 75.9% and 64.2%, respectively.
In the same manner as in Example 1, the visible light transmittance is 50% or more,
The solar heat gain rate was 70% or less and the visible light transmittance was higher than the solar heat gain rate.

A thin film of metal Cr or SUS was formed on the tin oxide film by the DC magnetron sputtering method, and a tin oxide thin film was formed thereon by the DC magnetron sputtering method. The film thickness of each layer was adjusted so that the visible light transmittance was 60% to 70%. When the visible light transmittance and the solar heat gain of the obtained sample were measured,
The difference between the visible light transmittance and the solar heat gain was further widened.

Example 3 Several kinds of multilayer films including a film of Ag alone were formed on a colorless soda lime silica glass having a thickness of 15 mm by the DC magnetron sputtering method. Table 3 shows an example of the structure of the formed multilayer film. The zinc oxide layer, which is the underlying dielectric layer, was formed by using a metallic Zn target and using a reactive DC magnetron sputtering method in an atmosphere of 100% oxygen. Next, after changing the atmosphere to 100% Ar gas, an Ag film was formed to a thickness of 10 nm by a DC magnetron sputtering method using an Ag metal target, and metal Zn was continuously formed.
Was formed into a thin film having a thickness that does not affect the optical characteristics. The thin metal layer (Zn) has an effect of suppressing deterioration of the Ag layer due to the zinc oxide film further formed on the thin metal layer (Zn). Next, a ZnO layer was formed again in the atmosphere of 100% oxygen by the same DC magnetron sputtering method as the first layer. In addition, although the film thickness of each layer (ZnO, Ag, Zn) of the film of the veneer plate 3-2 used in Example 3-2 in Table 3 is different from the method described for the veneer plate 3-1. The films were sequentially formed by the same method. The spectral transmittance, the spectral reflectance and the infrared reflection characteristic of the glass single plate on which the coating film containing the Ag simple substance film was formed were measured. The results are shown in Table 3.

[0038]

[Table 3]

Further, since the coating including the Ag single plate film lacks the durability enough to be used as a single plate, the main surface on which the film is formed faces the room to form the outdoor glass 11, and the thickness is 3 mm.
The colorless soda lime silica glass of the indoor glass 12
As a result, a multi-layer glass 13 having a thickness of 12 mm and a layer of dry air sealed therein was produced. The optical characteristics and solar heat gain of this double glazing were also measured. The results are also shown in Table 3.

Table 3 shows a heat ray-shielding glass obtained by coating a tin oxide film doped with fluorine by a thermal CVD method on a colorless float glass having a thickness of 15 mm according to Example 2 and the heat ray-shielding glass as shown in FIG. It also shows the properties of the laminated glass.

In Table 3, for example, the multilayer 3-2 has a visible light transmittance of 10% lower than that of the multilayer glass of Comparative Example 5, but the solar heat gain coefficient is 24% lower. The rightmost column of Table 3 is a numerical value indicating the ratio of the solar energy absorbed by the glass taken into the room. The comparison of these numerical values also reveals that the effects of the present invention are remarkably exhibited in each of the examples.

[0042]

EFFECTS OF THE INVENTION According to the present invention, it is possible to provide a glass having a low solar heat gain rate without deteriorating the visible light transmittance so as to cause a practical problem.

Heat-shielding glass is often used in building structures, but glass used in high places has a thickness required for wind pressure resistance. Generally, for example, the height above ground is 3
For a 0 m window, a glass window of 3 m ² or more has a thickness of 8
Glass with a thickness of mm or more, and a glass window with a thickness of 7 m ² or more has a thickness of 1
A glass of 5 mm or more is required. Therefore, the heat ray-shielding glass according to the present invention has a solar radiation shielding effect and the like while also having the wind pressure resistance performance required when used at a high place.

[0044]

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of one embodiment of a heat ray shielding glass according to the present invention.

FIG. 2 is a diagram showing an example of a film of a heat ray shielding glass according to the present invention.

FIG. 3 is a schematic cross-sectional view of an example of the heat ray-shielding double-layer glass according to the present invention.

FIG. 4 is a schematic cross-sectional view of another embodiment of the heat ray-shielding double glazing according to the present invention.

FIG. 5 is a schematic cross-sectional view of an embodiment of a heat ray-shielding laminated glass according to the present invention.

FIG. 6 is a diagram showing spectral transmission characteristics of soda lime silica glass.

[Simple explanation of symbols]

1, 1a, 1b: glass substrate, 2: coating film, 3, 4, 1
4, 24, 34: main surface of glass substrate, 5: base dielectric film, 6: Ag film, 7: protective dielectric film, 8: spacer,
9: Sealant, 10: Intermediate film

Front page continuation (72) Inventor Kenji Murata 3-5-11 Doshumachi, Chuo-ku, Osaka City Japan Sheet Glass Co., Ltd.

Claims (8)

[Claims] 1. A glass substrate and a coating film formed on one of its main surfaces, the glass substrate having a visible light transmittance of 5
When the visible light transmittance is 5% or more, the solar radiation absorptivity is 15% or more, and the vertical emissivity of the coating is 0.3 or less.
A heat ray-shielding glass which is 0% or more and has a solar radiation heat gain rate of not less than 70% for incident from a main surface opposite to the main surface on which the coating is formed. . 2. The heat ray shielding glass according to claim 1, wherein the glass substrate is made of soda lime silica glass having a thickness of 8 mm or more. 3. The heat ray shielding glass according to claim 1, wherein the glass substrate is made of soda lime silica glass to which a trace coloring component is added as a solar radiation absorbing component. 4. The heat ray-shielding glass according to claim 1, wherein the coating film has a surface resistance value of 40 Ω / square or less. 5. The coating film is a multilayer film including a conductive coating film containing at least one of Ag, Au, Cu, and Al as a main component, a single layer film containing a conductive oxide as a main component, or a single layer film containing a conductive oxide. The heat ray-shielding glass according to claim 1, wherein the heat ray-shielding glass comprises a multilayer film including a layer film. 6. The visible light reflectance on the main surface side on which the coating is formed is 10% or less.
The heat ray shielding glass according to any one of 5 above. 7. A multi-layer glass in which a plurality of glass plates are adjacent to each other and are airtightly sealed and adhered integrally with each other in a state where they are separated from each other, or a plurality of glass plates A glass composite consisting of laminated glass adhered and integrated by a plastic intermediate film arranged on the bonding surface of the glass plates, wherein at least one of the plurality of glass plates comprises a glass substrate and its main surface. The visible light transmittance of the glass substrate is 55% or more, the solar absorptivity is 15% or more, and the vertical emissivity of the film is 0.3 or less, and the visible light transmittance is 50%. The heat ray-shielding glass having the above solar radiation heat gain rate of 70% or less and the solar radiation heat gain rate of incidence from the side opposite to the main surface on which the coating is formed is specified. Heat-shielding glass composite to be used. 8. A multi-layer glass, or a plurality of glass plates, in which a plurality of glass plates are adjacent to each other and are airtightly sealed and adhered integrally with each other in a state in which adjacent glass plates are separated from each other. A glass composite consisting of laminated glass adhered and integrated by a plastic interlayer disposed on the bonding surface of the glass plates, wherein the vertical emissivity is present on at least one of the main surfaces of the plurality of glass plates. Forming a film of 0.3 or less,
In the state where the solar energy incident from any one of the outermost main surfaces of this glass composite is absorbed by 15% or more before reaching any one of the main surfaces on which the coating film is formed, the solar energy is not formed. When the visible light transmittance of the glass composite is 55% or more, the visible light transmittance is 50%.
The solar heat energy acquisition rate is equal to or more than the solar heat energy acquisition rate for the incident from the same direction as the solar energy and is 7 or more.
A heat ray-shielding glass composite characterized by being 0% or less.