JP2018002564A - Gray color tone low radiation glass - Google Patents

Abstract

An object of the present invention is to obtain a low-emissivity glass exhibiting a gray tone with good appearance quality. A low-emissivity glass having a low-emissivity film exhibiting a gray tone formed on a surface of a glass plate, wherein the low-emissivity film comprises, in order from the surface of the glass plate, a first dielectric layer, a first Ag layer, It has a first barrier layer, a second dielectric layer, a second Ag layer, a second barrier layer, and a third dielectric layer, wherein the first barrier layer has a solar absorptivity of 0 to 6%, a solar absorptance of the second barrier layer of 20-35%, and a glass surface reflectance of said low-emissivity glass of less than 10%. [Selection drawing] Fig. 1

Description

  The present invention relates to a low emission glass having a low emission film on the glass surface, and particularly to a low emission glass exhibiting a gray color tone.

  In recent years, for the purpose of improving cooling and heating efficiency, window glass using low radiation glass in which a low radiation laminated film (hereinafter sometimes referred to as a low radiation film) is formed is becoming widespread. This low-emission glass incorporates visible light into the room and meets the daylighting requirements of window glass, while the low-emission film reflects light from the near-infrared region to the infrared region. Temperature rise can be suppressed. Moreover, in order to interrupt | block the transmission of the heat | fever from the room | chamber interior, the capability to heat-insulate and insulate a room | chamber interior is also high.

  As such a low radiation film, a film using a metal layer mainly composed of Ag is widely used. For example, in Patent Document 1, the total geometric thickness of the second layer and the fourth layer, which is a metal layer mainly composed of Ag, is 22 to 29 nm, and the geometric thickness of the second layer is the geometry of the fourth layer. The total thickness of the first, third, and fifth layers of the dielectric layer is 220 to 380 nm, the third layer has an optical thickness of 140 to 200 nm, and is 0.3 to 0.8 times the thickness. The glass laminated body for windows in which the optical thickness of one layer is 0.4 to 1.5 times the optical thickness of the fifth layer and the reflectance in the near infrared region is improved is disclosed. In the embodiment, the window glass laminate has a visible light transmittance of 70% or more and a solar radiation transmittance of about 33 to 40%.

  As described above, the low-emission film having a visible light transmittance of 70% or more is provided with daylighting properties. On the other hand, for example, office buildings and the like are dazzled by sunlight and reflected light from adjacent buildings. For the purpose of reducing (glare), there is a demand for a window material having a visible light transmittance lower than 70% as described above. used. As a type that attaches importance to heat shielding properties, low radiation glass having a visible light transmittance of less than 70% and a solar radiation transmittance of 40% or less is incorporated in a double-glazed glass, and the solar heat acquisition rate of the double-glazed glass Has been studied.

  For example, in Patent Document 2, an absorption layer that absorbs solar radiation to some extent is provided on a transparent plate, and solar radiation in which a laminated film including a layer mainly composed of Ag as described above and a transparent dielectric layer is formed thereon. A shielding light-transmitting plate is disclosed. In an Example, the solar radiation transmittance | permeability in the single plate | board of the said solar shading translucent board is 21-35% or less, and the solar heat acquisition rate when it is set as a multilayer glass is 0.29-0.40.

  Further, for example, in Patent Document 3, on a substrate, a first dielectric layer, a first Ag layer, a first barrier layer, a first absorption layer, a second dielectric layer, A second Ag layer, a second absorption layer, a third dielectric layer, and optionally a topcoat layer, wherein either the first absorption layer or the second absorption layer is arbitrarily selected A low emissivity coating is disclosed. The low emissivity coating achieves chemical and mechanical durability and attractive appearance quality by providing an absorbing layer on the barrier layer.

  The barrier layer is a layer generally provided on the surface of the Ag layer. When the Ag layer is oxidized, there is a potential problem that it deteriorates as a low radiation film. However, when sputtering is performed using a reactive gas containing oxygen when forming a film above the Ag layer, the lower Ag layer is also oxidized. Therefore, a barrier layer is provided on the surface of the Ag layer using an inert gas, and an upper layer is formed on the barrier layer. Usually, the barrier layer is oxidized by a reactive gas containing oxygen when forming the upper layer.

  As the barrier layer as described above, a Zn film containing Al (hereinafter sometimes referred to as “ZnAl”), Ti film, Cr film, stainless steel (Fe—Ni—Cr alloy) film, Ni and Cr Alloy films and the like are known (for example, Patent Documents 3 to 5).

JP 2010-195638 A JP-A-11-228185 Special table 2008-540320 gazette JP-A-7-187727 Japanese Patent Laid-Open No. 11-343146

  In recent years, low-emission glass using a low-emission film having two Ag layers as described above has attracted attention as a window material for buildings. Conventionally, in the case of a building using concrete on the wall surface, such as a building, a glass having a transparent color such as blue, green, yellow, etc., and a reflective color such as blue, green, etc., which is low in saturation and low saturation is used. The visible light transmittance was 60% or more, and it had an appropriate daylighting property. In addition, from the design side of the building, in order to give a characteristic to the color of the appearance quality, the color of the reflection color such as blue or green is raised and the reflectance is further increased, in which case A glass having a visible light transmittance of about 50 to 60% and a reflectance of 10 to 20% was used. On the other hand, as a glass seeking a sense of unity with a wall surface, there is an increasing demand for a glass having a transmitted color with reduced saturation and lightness, and a reflectance and reflected color that cannot be overstated.

As one method for obtaining the glass as described above, when the thickness of the glass plate is 3 mm, the visible light transmittance is as low as about 50% or less and the transmitted color is an intermediate color (for example, CIE L ^* a ^* b ^* chromaticity). Examples thereof include gray-tone glass in which a ^* and b ^* of transmitted light in the coordinate diagram are within a range of −5 to +2 respectively. In order to reduce the visible light transmittance, the thickness of the Ag layer may be increased. In this case, however, the reflectivity increases and glare increases, so that the reflection blue or green is more reflective than the transmission gray color. There is a problem in that the appearance quality is impaired because the color tone of the color becomes noticeable or the reflection color when viewed obliquely tends to be reddish.

  Accordingly, an object of the present invention is to obtain a low emission glass exhibiting a gray color tone with good appearance quality.

  As a result of intensive studies on the above problems by the present inventors, the low emission glass having an appropriate daylighting property and having a gray color tone has a potentially high reflectance of the glass surface of the low emission glass. I found out that they tend to end up. Further examination from the obtained knowledge revealed that the barrier layer formed on the outermost Ag layer of the low-emission film has an absorption rate from the visible region to the infrared region (hereinafter referred to as “sunlight absorption rate”). It has been found that the reflectance of the glass surface of the low emission glass can be made less than 10%. Furthermore, when the solar radiation absorptivity of the barrier layer formed on the Ag layer on the glass plate side exceeds a specific amount, it has also been found that the reflectance of the glass surface increases conversely.

  Accordingly, the present invention provides a low radiation glass in which a low radiation film exhibiting a gray color tone is formed on a glass plate surface. The low radiation film comprises, in order from the glass plate surface, a first dielectric layer and a first Ag layer. , The first barrier layer, the second dielectric layer, the second Ag layer, the second barrier layer, and the third dielectric layer, and the first barrier layer has a solar absorptance of 0. It is a gray tone low radiation glass characterized in that the solar radiation absorption rate of the second barrier layer is ˜6% and the glass surface reflectance of the low radiation glass is less than 10%.

  According to the present invention, it is possible to obtain a low emission glass exhibiting a gray color tone with good appearance quality.

It is a cross-sectional schematic diagram showing one Embodiment of the low radiation film | membrane of this invention. It is a cross-sectional schematic diagram showing one Embodiment of the multilayer glass of this invention. It is the figure which showed a ^* and b ^* of the transmitted light of an Example and a comparative example. It is the figure which showed a ^* and b ^* of the reflected light of the glass surface of an Example and a comparative example.

  The present invention relates to a low emission glass in which a low emission film having a gray color tone is formed on a glass plate surface, the low emission film in order from the glass plate surface, a first dielectric layer, a first Ag layer, It has a first barrier layer, a second dielectric layer, a second Ag layer, a second barrier layer, and a third dielectric layer, and the first barrier layer has a solar absorptance of 0 to It is a gray color low radiation glass characterized by 6%, the solar radiation absorption rate of the second barrier layer is 20 to 35%, and the glass surface reflectance of the low radiation glass is less than 10%.

1: Explanation of terms (gray tone)
“Gray color tone” in the present invention means that the visible light transmittance obtained by a method according to JIS R3106 (1998) when the thickness of the glass plate is 3 mm is 50% or less, and conforms to JIS Z8781-4. In the values expressed by CIE L ^* a ^* b ^* chromaticity coordinate diagram for the transmitted color of the low emission glass plate calculated as above, a ^* and b ^* are in the range of -5 to +2, respectively. And

(Solar radiation absorption rate)
The solar radiation absorptivity of the entire low radiation film was calculated by a method based on JIS R3106 (1998). In addition, since it is difficult to measure the solar absorptivity of the barrier layer only from the formed low radiation film, the solar absorptivity of the obtained sample is measured by forming a film with a glass plate / barrier layer / dielectric layer. The solar radiation absorption rate of the barrier layer was determined by removing the solar radiation absorption rate of the glass plate and the dielectric layer from the obtained solar radiation absorption rate. The film formation conditions at this time, the glass plate, the barrier layer, and the dielectric layer to be used were the same as the various conditions of the low radiation film to be produced.

(Glass surface reflectance)
The reflectance of the glass surface of the low radiation film (hereinafter sometimes referred to as “glass surface reflectance”) was calculated by a method based on JIS R3106 (1998).

(Physical film thickness)
The physical film thickness means the same as a generally used film thickness, and is simply a thin film thickness. In this specification, the film-forming speed at the time of producing the single-layer film is calculated from the product of the film thickness of the single-layer film produced under the same film-forming conditions as in the production of the low-emission film and the conveyance speed of the substrate. This is a value obtained by calculating the film thickness of the corresponding layer of the low emission film using the film formation rate.

(Optical film thickness)
The optical film thickness is a value represented by the product of the physical film thickness and the refractive index. In this specification, the refractive index at a wavelength of 550 nm of a single-layer film manufactured under the same film forming conditions as in the low-emission film manufacturing. And a value calculated from the product of the film thickness. The refractive index in the present invention is determined by measuring the transmittance and reflectance of a single layer film with a spectrophotometer (U-4000, manufactured by Hitachi, Ltd.) and calculating the refractive index from the obtained value by an optical simulation (Reflectance-transmittance method). did.

(Description of membrane)
In this specification, “ZnAl” refers to a film in which Al is mixed with Zn, and does not indicate that Zn and Al are mixed at 1: 1. Although content of Al is selected suitably, it is good also as 1-10 wt%, for example. A film in which ZnAl is oxidized is described as “AZO”, but this does not indicate that Zn: Al: O is 1: 1: 1.

  Further, “NiCr” indicates an alloy film mainly containing Ni and Cr, and does not indicate that Ni and Cr are mixed at 1: 1. The content of the above components may be selected as appropriate. For example, the Ni content may be 55 to 85 wt%, and the Cr content may be 10 to 25 wt%. Further, other elements such as Fe may be included.

  Further, “stainless steel” particularly refers to a mixture of Fe, Cr, and Ni, and may be referred to as “SUS” hereinafter. The content of the above three components may be selected as appropriate. For example, the content of Fe may be 50 to 80 wt%, Cr may be 10 to 25 wt%, and Ni may be 0 to 20 wt%. Further, other elements such as Mn and Mo may be included.

  “ZnSn” indicates a film in which Sn is mixed with Sn, and does not indicate that Zn and Sn are mixed at 1: 1. The content of Sn is selected as appropriate, but may be, for example, 30 to 70 wt%. A film in which ZnSn is oxidized is described as “ZnSnO”, but this does not indicate that Zn: Sn: O is 1: 1: 1.

2: Low emission glass A preferred embodiment of the low emission film of the present invention is shown in FIG. The low radiation film 2 is formed on the glass plate 1 and may have any emissivity lower than that of the normal glass plate 1. For example, the low radiation glass 3 on which the low radiation film 2 is formed may have a vertical radiation rate measured in accordance with JIS R3106 of 0.3 or less as a “low radiation film”. Further, an arbitrary layer may be formed between the low emission film and the glass plate or on the surface of the uppermost layer of the low emission film.

  Moreover, the gray tone low radiation glass 3 of this invention can make the glass surface reflectance of the low radiation glass 3 less than 10%. Usually, the low emission glass 3 is used as a double-layer glass, but the low emission film 2 of the low emission glass 3 is arranged so as not to be in direct contact with the outdoors or indoors. That is, since the low radiation glass 3 is in contact with the outdoors or indoors on the glass surface, glare can be suppressed by reducing the reflectance of the glass surface.

  The low radiation glass of the present invention may have a low reflectance, and when viewed in a general construction environment, the transmitted color and the reflected color of the glass surface are easily recognized. Here, in general, green is known as a color with high relative visibility. When the reflected color is actually green, the green color is strongly visible, and the overall color is green with the transmitted color. It has been newly found that it is easy to look like a grayish tone. Moreover, when the reflected color is tinged with red, it often becomes a heterogeneous color in the construction environment, and the color becomes noticeable, making it difficult to achieve harmony with the environment. Further, when the reflected color is yellowish, yellow has a complementary color relationship with blue, and is likely to appear clearly conspicuous with respect to the sky blue. As a result of investigations by the inventors with respect to the above problem, it is found that, particularly when the reflection color is in a range showing a light blue color, it is not conspicuous even when combined with the gray color of the transmission color, and exhibits a gray tone as a whole. It was.

Therefore, gray tone low emissivity glass 3 of the present invention, the CIE ^L * ^a * ^{b *} chromaticity coordinates diagram the reflection color of the glass surface, the ^{a *} -5 to 0, and -12 5 ^{b *} Is preferred. It is preferable to set a ^* within a range of −5 to 0 because it is possible to suppress the reflected color of the glass surface from being red or green. Further, b ^* is preferably in the range of -12 to -5. In general, b ^* becomes more negative as b ^* is larger, but when b ^* is less than -12, the blueness of reflection is recognized strongly, and when viewed in the construction environment, the impression of blue rather than gray May become stronger. Since blue has a low specific luminous sensitivity, the blue color of the reflected color is not noticeable within the above range, and the entire low-emission glass can exhibit a gray color tone. Preferably, b ^* may be -10 to -5. The upper limit value of b ^* is set to -5. This is to prevent the green and red colors from appearing stronger than blue due to the balance with a ^*, and the absolute value of a ^* is sufficiently high. If it is small (a ^* is close to 0), it may exceed -5 as long as it is not yellowish.

(Glass plate)
Although the glass plate 1 to be used is not particularly limited, for example, commonly used soda lime glass, alkali-free glass, high-permeability glass, air-cooled tempered glass, chemically tempered glass, meshed glass, and lined glass Borosilicate glass, low expansion glass, zero expansion glass, low expansion crystallized glass, zero expansion crystallized glass, and the like can be used.

  In addition to the glass plate 1, a transparent substrate such as a resin may be used. Examples thereof include polyethylene terephthalate resin, polyethylene naphthalate resin, polyethersulfone resin, polycarbonate resin, and polyvinyl chloride resin.

  Although the thickness of the glass plate 1 is not specifically limited, It is good also as 3-19 mm generally used as architectural glass. Visible light transmittance and solar radiation transmittance may be affected by the thickness of the substrate, and the transmittance tends to decrease as the substrate becomes thicker. For example, when a 3 mm glass substrate and a 6 mm glass substrate used as the building glass are compared, the 3 mm glass substrate has a higher visible light transmittance of about 0.5 to 1.5%.

(Dielectric layer)
The dielectric layers 11a, 11b, 11c are transparent thin films of oxide, nitride, or oxynitride containing at least one selected from the group consisting of Al, Si, Ti, Zn, In, and Sn. preferable. The first layer 11a, the second layer 11b, and the third layer 11c of the dielectric layer are for adjusting the reflection color of the low radiation film, and each film thickness may be appropriately adjusted according to desired characteristics. Each layer may be a laminate of two or more types of films. Note that it is preferable to dispose a film having a zinc oxide structure at a position in contact with the Ag layer because the crystallinity of the Ag layer is improved.

  In order for the low emission glass to have a gray color tone, the first dielectric layer 11a has a thickness of 60 to 120 nm, the second dielectric layer 11b has a thickness of 160 to 240 nm, and the third dielectric layer 11c has a thickness of 25. It is preferable to be set to ˜65 nm. More preferably, the first dielectric layer 11a may be 80 to 100 nm, the second dielectric layer 11b may be 180 to 210 nm, and the third dielectric layer 11c may be 30 to 50 nm.

The first dielectric layer 11a acts as an underlayer for the first Ag layer 12a, and improves the adhesion between the first Ag layer 12a and the glass plate 1. It is preferable to use ZnO, SnO ₂ , ZnSnO, Si ₃ N ₄ and TiO ₂ . Each of ZnO, SnO ₂ , ZnSnO, and TiO ₂ may be an oxide film or an alloy oxide film containing an optional third component. Si ₃ N ₄ may be a nitride film or an alloy nitride film containing an optional third component.

The second dielectric layer 11b is formed on the first barrier layer 13a, and is a layer that greatly affects the reflection color and solar transmittance of the low radiation film 2. The second dielectric layer 11b has an oxide dielectric. For example, _ZnO, SnO 2, ZnSnO and TiO ₂ and the like. When forming the second dielectric layer 11b, it is possible to oxidize the lower first barrier layer 13a simultaneously by forming the film in a reactive gas atmosphere containing oxygen.

The third dielectric layer 11c is formed on the second barrier layer 13b and interacts with other dielectric layers to adjust the reflection color and solar transmittance. As the first dielectric layer 11a, the third dielectric layer 11c is preferably made of ZnO, SnO ₂ , ZnSnO, Si ₃ N ₄ and TiO ₂ . The third dielectric layer 11c is preferably two or more layers, and the uppermost layer 14 formed on the most surface side is desirably a film that improves the moisture resistance and durability of the low radiation film 2. For example, a transparent thin film of an oxide, nitride, or oxynitride containing at least one selected from the group consisting of Al, Si, and Ti can be given. Moreover, it is preferable to set the physical film thickness to 3 to 20 nm because moisture resistance and durability are improved.

(Ag layer)
The Ag layer is a layer having a function of reflecting infrared rays. Further, it is a layer containing Ag as a main component, and is an Ag film or an Ag alloy film containing Ag as a main component. The Ag alloy film may contain, for example, metals such as palladium, gold, platinum, nickel and copper within a range of 5 wt% or less. Further, the “main component” refers to containing 90 wt% or more of Ag.

  In the present invention, the total physical film thickness of the first Ag layer 12a and the second Ag layer 12b is preferably in the range of 12 to 22 nm. More preferably, it may be 13 nm to 19 nm. By setting the thickness of the Ag film within the above range, it is possible to have both a good appearance and a low radiation function. In addition, by setting the film thickness of the second Ag layer 12b ≧ the film thickness of the first Ag layer 12a, the reflection color of the glass surface is suppressed from being reddish, and the saturation of the reflection color is suppressed. Is possible.

(Barrier layer)
The first Ag layer 12a and the second Ag layer 12b form a barrier layer on each layer for the purpose of preventing Ag from deteriorating during the manufacturing process. In the present invention, a gray color tone and good appearance quality are obtained by using a layer having a solar radiation absorption rate of 20 to 35% as the second barrier layer. Further, if necessary, both the first barrier layer 13a and the second barrier layer 13b may be formed by laminating a plurality of films, or two or more kinds of metal components may be mixed in one film.

  The first barrier layer 13a preferably contains at least one selected from the group consisting of oxidized ZnAl, Ti, NiCr, Nb and stainless steel as a component. The first barrier layer 13a is oxidized when the second dielectric layer 11b is formed, and the solar radiation absorption rate is lowered. At this time, it is only necessary that the solar radiation absorption rate is 6% or less, and it is not necessary to be completely oxidized.

  The film thickness of the first barrier layer 13a may be set to a thickness that allows oxidation, nitridation, and oxynitridation, and may be appropriately selected according to the components and apparatus to be used. For example, in the examples of the present specification, the physical film thickness is set to 7.7 nm or less when a ZnAl film is used as the first barrier layer 13a, and the thickness is set to about 2.6 nm or less when a Ti film is used. The appropriate film thickness range varies depending on the apparatus and film forming conditions.

  The second barrier layer 13b preferably has one selected from the group consisting of Ti, NiCr, Nb, and stainless steel that are not oxidized or nitrided. Moreover, as long as the solar radiation absorption rate falls within the range of 20 to 35%, it may be partially oxidized or nitrided. If a reactive gas is used when forming the third dielectric layer 11c, the third dielectric layer 11c side of the second barrier layer 13b may be oxidized or nitrided by the reactive gas. However, as a result of investigations by the inventors, it is found that the thickness at which the second barrier layer 13b is oxidized or nitrided has an upper limit, and if the thickness is larger than the upper limit, the solar radiation absorption rate is increased. It becomes possible. The optimum film thickness of the second barrier layer 13b varies depending on the device and the type of film. For example, in the examples of the present specification, when using a Ti film, the physical film thickness is set to about 5 to 6 nm.

The sum of the optical thicknesses of the first, second, and third dielectric layers is 300 to 340 nm, the physical thickness of the first Ag layer is 6 to 10 nm, and the physical thickness of the second Ag layer is The thickness is preferably 8 to 10 nm. By making each film thickness within the above range, the b ^* of the reflected color of the glass surface can be set within the range of -12 to -5.

3: Manufacturing method of low emission film | membrane Below, the manufacturing method of the low emission glass of this invention is demonstrated.

  The low radiation transmissive glass of the present invention is preferably formed by a sputtering method, an electron beam vapor deposition method, an ion plating method, or the like, but the sputtering method is suitable because it is easy to ensure productivity and uniformity.

  The formation of the low radiation film by the sputtering method is performed while the glass plate 1 is transported in an apparatus in which a sputtering target as a material of each layer is installed. At this time, an atmospheric gas used for sputtering is introduced into the vacuum chamber for film formation provided in the apparatus, and a negative potential is applied to the target to generate plasma in the apparatus for sputtering. Do.

  In addition, a method for obtaining a desired film thickness is not particularly limited because it varies depending on the type of the sputtering apparatus, but a method for controlling the film thickness by changing the film formation rate by adjusting the power input to the target or the introduction gas condition, A method of controlling the film thickness by adjusting the substrate conveyance speed is widely used.

When forming each dielectric layer, the target to be used may be either a ceramic target or a metal target. In any case, the gas conditions of the atmospheric gas to be used are not particularly limited. For example, the gas type and the mixing ratio may be appropriately determined according to the target film from Ar gas, O ₂ gas, N ₂ gas, or the like. Further, as the gas to be introduced into the vacuum chamber, Ar gas, O ₂ gas, may include any third component other than N ₂ gas.

Further, when the second dielectric layer 11b is formed, in a reactive gas atmosphere such as O ₂ gas, N ₂ gas, and CO ₂ gas so that the first barrier layer 13a can be oxidized or oxynitrided. It is preferable to form a film.

  When forming an Ag layer, an Ag target or an Ag alloy target is used as a target to be used. Ar gas is preferably used as the atmospheric gas introduced at this time, but different types of gases may be mixed as long as the optical properties of the Ag film are not impaired.

  When the first barrier layer 13a is formed, a target to be used may be selected as appropriate, and an inert gas such as Ar may be used as the introduced atmospheric gas. At this time, the first barrier layer 13a is formed to a thickness that allows oxidation or nitridation in a later step as in the conventional case.

  When the second barrier layer 13b is formed, one layer selected from the group consisting of Ti, NiCr, Nb, and SUS is formed in an inert gas atmosphere. The second barrier layer 13b is not completely oxidized even after the upper dielectric film is formed, and it is preferable to increase the film thickness in order to leave a portion that exists as a metal component. When an inert gas is used at the time of forming the body layer 11c, the thickness may be set so that the solar radiation absorption rate is 20 to 35%.

  A DC power source, an AC power source, and a power source in which AC and DC are superimposed can be used as the plasma generation source. If abnormal discharge is likely to occur when forming a dielectric layer, a pulse is applied to the DC power source. It is preferable to use a power source or an AC power source.

4: Multi-layer glass In the present invention, the low-emission glass 3 may be used as a single plate or laminated glass, but when used as a multi-layer glass as shown in FIG. 2, the low-emission film 2 can be protected. This is preferable because it is possible. That is, the present invention is a multi-layer glass in which the above-described gray tone low emission glass and a glass plate are integrated via a spacer, and the surface on which the low emission film of the low emission glass is formed is on the spacer side. It is a double glazing characterized by being in.

When used as a multi-layer glass, the surface of the low emission glass 3 on which the low emission film 2 is formed is opposed to another glass plate 1 with a predetermined interval so as to form a hollow layer 23, and the peripheral portion is a spacer 21 or a seal. Seal with material 22. The hollow layer 23 is filled with an inert gas such as Ar, He, Ne, Kr, or Xe, dry air, N ₂ or the like, and normally uses dry air, but further improves heat insulation performance and sound insulation performance. Ar gas, Ne gas, or the like may be used for the purpose.

  The spacer 21 has a desiccant inside, and is fixed between at least two glass plates via a sealing material (not shown) such as butyl rubber or silicone, and a lightweight aluminum material or resin material is used. It is done. A portion surrounded by the spacer 21, the low radiation glass 3, and the glass plate 1 is a hollow layer 23, and the heat insulating property of the multilayer glass can be changed depending on the thickness of the hollow layer 23 and the kind of gas to be enclosed. Is possible.

  Examples of the present invention and comparative examples are shown below. Table 1 shows the structures of the low-emission films of Examples and Comparative Examples. In addition, the notation of the barrier layer describes the type and film thickness of the film immediately after the barrier layer is formed. Actually, when the upper dielectric film is formed, part or all of the film from the interface on the dielectric layer side is described. It is in an oxidized state.

  In all Examples and Comparative Examples, a film was formed on soda lime glass having a thickness of 3 mm using a magnetron sputtering apparatus. Further, in any of the examples and comparative examples, the glass plate and the film were not heated, and heating was not particularly performed except when the glass plate temperature increased due to sputtering during film formation.

  Each layer obtained the film thickness described in Table 1 by adjusting the conveyance speed of a glass plate. Moreover, the said conveyance speed used the speed | rate calculated for every kind of film | membrane previously forming the single layer film | membrane.

(Examples 1 to 4, Comparative Examples 1 and 3)
First, the glass plate 1 was held on a base material holder, and a desired target was placed in each vacuum chamber. The target has a magnet disposed on the back side. Next, the inside of the vacuum chamber was evacuated by a vacuum pump.

  Next, the first dielectric layer 11 a was formed on the glass plate 1. A Zn target to which 2 wt% Al was added (hereinafter also referred to as “ZnAl”) was used as a target, and 1100 W of electric power was supplied to the ZnAl target from a DC power source through a power cable. At this time, while continuously operating the vacuum pump, argon gas was introduced into the vacuum chamber at 20 sccm and oxygen gas was introduced at 40 sccm, and the pressure was adjusted to 0.4 Pa. Thus, a ZnAlO film was obtained.

  Next, a first Ag layer 12a was formed on the ZnAlO film. The target was an Ag target, the atmosphere gas in the vacuum chamber was argon gas introduced at 45 sccm, and the pressure was adjusted to 0.3 Pa. The power supplied from the DC power source was 300W. As described above, an Ag film was obtained.

  Next, a first barrier layer 13a was formed on the Ag film. A ZnAl target in which 4 wt% of Al was added to the target, and the atmosphere gas in the vacuum chamber was introduced with argon gas at 100 sccm, and the pressure was adjusted to 0.7 Pa. The power input from the DC power source was 180 W. Thus, a ZnAl film was obtained.

  Next, a ZnAlO film was formed as the second dielectric layer 11b on the first barrier layer 13a. The film forming conditions were the same as those for the first dielectric layer 11a except that the conveyance speed was adjusted to obtain a desired film thickness.

  Next, a second Ag layer 12b was formed on the ZnAlO film. The film forming conditions were the same as those of the first Ag layer 12a except that the conveyance speed was adjusted to obtain a desired film thickness.

  Next, a Ti film was formed as a second barrier layer 13b on the Ag film. Ti target was introduced into the target, and argon gas was introduced at 80 sccm as the atmospheric gas in the vacuum chamber, and the pressure was adjusted to 0.6 Pa. The power input from the DC power source was 330 W. Thus, a Ti film was obtained.

  Next, a ZnSnO film was first formed as the third dielectric layer 11c on the second barrier layer 13b. A ZnSn target in which 50 wt% of Sn was added to the target, the atmosphere gas in the vacuum chamber was introduced with 10 sccm of argon gas and 50 sccm of oxygen gas, and the pressure was adjusted to 0.4 Pa. Moreover, the electric power input with DC power supply was 1100W. As a result, a ZnSnO film was obtained.

Next, a TiO ₂ film was formed as a top layer 14 on the ZnSnO film. The target was a Ti target, and the atmospheric gas in the vacuum chamber was introduced with argon gas at 40 sccm and oxygen gas at 40 sccm, and the pressure was adjusted to 0.5 Pa. Moreover, the electric power input with DC power supply was 3050W. From the above, a TiO ₂ film was obtained.

(Example 5, Comparative Example 4)
A low-emission film was obtained in the same manner as in Example 1 except that Ti was used for the first barrier layer 13a and the conveyance speed was adjusted to obtain the film thickness as shown in Table 1. The first barrier layer 13a was formed by introducing a Ti target into the target, introducing argon gas at 80 sccm as the atmospheric gas in the vacuum chamber, and adjusting the pressure to 0.6 Pa. The power input from the DC power source was 330 W.

(Comparative Example 2)
A low emission film was obtained in the same manner as in Example 1 except that ZnAl was used for the second barrier layer 13b and the conveyance speed was adjusted to obtain the film thickness as shown in Table 1. The second barrier layer 13b was formed by using a ZnAl target in which 4 wt% of Al was added to the target, argon gas was introduced at 80 sccm as the atmospheric gas in the vacuum chamber, and the pressure was adjusted to 0.7 Pa. The power input from the DC power source was 180 W.

(Optical characteristics of low emission glass)
The optical characteristics of the low emission glass obtained in the above examples and comparative examples were measured using a self-recording spectrophotometer (manufactured by Hitachi, Ltd., U-4000). The visible light transmittance, the visible light reflectance of the glass surface, and the solar absorptivity were calculated according to JIS R3106 (1998). Further, the transmission color of the low emission glass and the reflection color of the glass surface were calculated according to JIS Z8781-4. The results obtained are shown in Table 2. In addition, FIG. 3 shows the transmitted colors a ^* and b ^* of Examples and Comparative Examples, and FIG. 4 shows the reflected colors a ^* and b ^* of the glass surface.

(Evaluation of solar radiation absorption rate of the barrier layer)
Since it is difficult to calculate the solar absorptance of only the barrier layer portion by evaluating the solar absorptance of the low radiation glass, the solar absorptivity of the barrier layer was measured by the following method.

  First, a barrier layer was formed on soda lime glass having a thickness of 3 mm in the same manner as in Examples and Comparative Examples, and a dielectric layer was formed on the barrier layer to prepare a measurement sample. That is, a laminated body of glass / first barrier layer 13a / second dielectric layer 11b and glass / second barrier layer 13b / third dielectric layer 11c is prepared, and the film of each barrier layer is formed. The type and film thickness were the same as in the examples and comparative examples.

  In addition, with regard to AZO and ZnSnO used in this example and the comparative example, in the range where the physical film thickness is 10 nm or more, the influence on the solar radiation absorption rate of the barrier layer is small even when the film thickness of the dielectric layer increases. I understood it. Therefore, the physical film thickness of the second dielectric layer 11b and the third dielectric layer 11c is set to 20 nm, respectively. The third dielectric layer 11c was not formed as the outermost layer.

  Next, the solar absorptivity of the obtained measurement sample was measured, and the value obtained by subtracting the solar absorptivity of the glass and the dielectric layer from the measured value was taken as the solar absorptivity of the barrier layer. In addition, the solar radiation absorptivity of glass and a dielectric material layer is described in the reference example 1 mentioned later. The obtained solar absorptance is shown in Table 3.

(Reference Example 1)
In order to obtain the solar radiation absorptivity of only the glass plate and the dielectric layer, a sample was prepared in which the dielectric layer was directly formed on the glass plate of soda lime glass under the same conditions as in Examples and Comparative Examples. When the physical film thickness of the dielectric layer was 20 nm, the solar absorptivity of the glass plate and the dielectric layer was 6.0% for AZO and 5.9% for ZnSnO. These values were used when calculating the solar radiation absorption rate of the barrier layer.

(Reference Example 2)
The influence of the film thickness of the dielectric layer on the solar absorptance of the barrier layer was examined by the same method as the above solar radiation absorptivity measuring method. For the measurement sample, a 2.4-nm Ti film was formed as a barrier layer on soda-lime glass with a thickness of 3 mm, and a ZnSnO film was formed as a dielectric layer on the TiN film with a thickness of 10 nm, 20 nm, and 30 nm. Three types were prepared. The solar radiation absorption rate of the barrier layer of the obtained sample was 4.1 to 4.6%, which was not significantly different.

  From the above, in the range where the Ti film is 2.4 nm and the dielectric layer is 10 to 30 nm, the barrier layer is not completely oxidized even if the thickness of the dielectric layer is changed, and in all cases the same degree of solar radiation absorption It was found to show the rate. Accordingly, it is presumed that even if the thickness of the dielectric layer is further increased, the oxidation state of the barrier layer is not greatly affected. This is because when the dielectric layer is formed on the barrier layer, the surface of the barrier layer is oxidized immediately after the start of film formation, so there is no significant difference even if the film formation time is extended. It is done.

From the above, in all of the examples, the visible light transmittance was 50% or less, and the transmitted light became an intermediate color. Moreover, the reflectance of the glass surface was less than 10%, and it had the favorable external appearance quality which suppressed glare. Furthermore, a ^* of the reflected light on the glass surface was in the range of −3 to −1.5, and redness and strong greenness were suppressed. In addition, b ^* is suppressed in a conspicuous color within a range of -10 to -6, and even if the reflected light of the glass surface is mixed with the intermediate color of the transmitted light, it exhibits a gray tone as viewed from the viewer. .

  On the other hand, the solar radiation absorptance of the first barrier layer is about 21%, and the solar barrier absorptivity of the second barrier layer is smaller than the range of claim 1. %, Which is not the object of the present invention. Further, in Comparative Examples 3 and 4 in which the second barrier layer is within the range of claim 1 and the solar radiation absorption rate of the first barrier layer exceeds 6%, the reflectance of the glass surface is somewhat suppressed to about 10%. However, the reflectance was higher than that of the example of the present invention. 3 and 4, there was no comparative example in which both the transmitted color and the reflected color on the glass surface were in the same range as the example.

1: glass plate, 2: low emission film, 3: low emission glass plate, 11a: first dielectric layer, 11b: second dielectric layer, 11c: third dielectric layer, 12a: first Ag layer, 12b: second Ag layer, 13a: first barrier layer, 13b: second barrier layer, 14: uppermost layer, 21: spacer, 22, sealing material, 23: hollow layer

Claims (5)

In the low emission glass in which a low emission film having a gray color tone is formed on the surface of the glass plate, the low emission film includes, in order from the glass plate surface, the first dielectric layer, the first Ag layer, and the first barrier. A layer, a second dielectric layer, a second Ag layer, a second barrier layer, and a third dielectric layer,
The solar absorptivity of the first barrier layer is 0 to 6%, the solar absorptivity of the second barrier layer is 20 to 35%,
A gray tone low emission glass characterized in that the glass surface reflectance of the low emission glass is less than 10%. The low radiation film is an optical film thickness,
The first dielectric layer is 60-120 nm,
The second dielectric layer is 160-240 nm,
The third dielectric layer is 25-65 nm,
The total thickness of the first Ag layer and the second Ag layer is 12 to 22 nm.
The thickness of the second Ag layer is equal to or greater than the thickness of the first Ag layer. 3. The gray according to claim 1, wherein the second barrier layer has at least one selected from the group consisting of Ti, NiCr, Nb, and stainless steel that are not oxidized or nitrided. 4. Color tone low emission glass. The reflection color of the glass surface of the low emission glass when the thickness of the glass plate is 3 mm is as follows. In the CIE L ^* a ^* b ^* chromaticity coordinate diagram, a ^* is −5 to 0, and b ^* is −12 to − 5. The gray tone low emission glass according to claim 1, wherein the gray tone low emission glass is 5. A multi-layer glass in which the gray tone low emission glass according to any one of claims 1 to 4 and a glass plate are integrated via a spacer, and a low emission film of the low emission glass is formed. Multilayer glass characterized in that the surface is on the spacer side.

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