JP2009280464A - Low radiation double glazing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide low radiation double glazing which can effectively reflect or transmit solar energy. <P>SOLUTION: The low radiation double glazing has at least a first glass plate and a second glass plate which are arranged opposite to each other, and on a second-glass-plate-opposing surface of the first glass, a first oxide film, an Ag film, a sacrificial metal film and a second oxide film are laminated in this order from the surface. The thickness of the Ag film is 6 to 10 nm, the thickness of the sacrificial metal film is 0.5 to 2.5 nm. In the first oxide film, a tin oxide film and an Al-doped ZnO film are laminated, and the thickness of the first oxide film is 25 to 30 nm. And in the second oxide film, a tin oxide film and an Al-doped ZnO film are laminated, and the thickness of the second oxide film is >40 to 50 nm. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a multilayer glass on which a low radiation film (Low Emissivity film) which is a low radiation laminate is formed.

  For the purpose of reducing the heating and cooling load in summer and winter, a heat ray low radiation multilayer glass provided with a heat ray shielding laminate (low radiation laminate) in which an Ag film and an oxide film are laminated on the surface of a glass plate, Used for building window openings. The Ag film functions as a heat ray reflective layer.

  For example, the present applicant has proposed a heat ray shielding laminate in Japanese Patent Application Laid-Open No. 2006-159580. In general, a zinc oxide film doped with Al is used instead of the zinc oxide film constituting the heat ray shielding laminate.

Further, the present applicant has proposed a low emission multilayer glass in Japanese Patent Application Laid-Open No. 2007-70146. The thin-film structure (low-emission laminate) provided in the low-emission multilayer glass is formed by laminating the first oxide film / Ag film / metal film / second oxide film in this order. ing. The film thickness ratio between the first oxide film and the second oxide film (the film thickness of the second oxide film / the film thickness of the first oxide film) is 1.0 to 1.3. The thickness of any oxide film is in the range of 30 to 40 nm. The Ag film has a thickness of 8 to 10 nm, and the metal film has a thickness of 1 to 8 nm.
JP 2006-159580 A JP 2007-70146 A

  In such a low radiation laminate, the ability to reflect heat rays has been emphasized. Specifically, in order to effectively reflect heat rays, in the above-mentioned Japanese Patent Laid-Open No. 2006-159580, the thickness of the metal film containing silver as a main component is set to 5 nm to 20 nm, and the above-mentioned Japanese Patent Laid-Open No. 2007-070146 is described. Also in the publication, the thickness of the Ag film is 8 to 10 nm.

  The present inventor has studied diligently about the heat input and output through the low-radiation multilayer glass in consideration of the difference between the south and middle altitudes of the sun in summer and winter. Specifically, we focused on energy consumption throughout the year for low-emission multilayer glass used in areas that require heating in winter. As a result, the present inventor has clarified that not only the heat rays are shielded in winter but rather the heat rays are moderately passed, the energy required for cooling and heating is reduced throughout the year.

  Moreover, as a low radiation | emission multilayer glass used for a building, it is preferable to have a favorable color tone.

  An object of the present invention is to provide a low radiation multilayer glass capable of effectively reflecting (shielding) or transmitting solar energy. Furthermore, the low radiation | emission multilayer glass which has a favorable color tone is provided.

  The low radiation multilayer glass of the present invention reduces the thickness of each of the Ag film and the sacrificial metal film in order to allow heat rays to pass through moderately, and increases the transmittance of sunlight in the winter when the incident angle of sunlight is small. At the same time, each film thickness of the low-emission laminate is adjusted so that the reflectance of sunlight in the summer when the incident angle is large is approximately the same as or slightly reduced from the conventional low-emission laminate. If it carries out like this, in the low radiation | emission multilayer glass, the selectivity which can reflect or permeate | transmit sunlight rays effectively with respect to the incident angle of the sun is improved.

  That is, the low radiation multilayer glass of the present invention is a multilayer glass in which at least a first glass plate and a second glass plate are arranged to face each other, and is opposed to the second glass plate in the first glass plate. A low-emission laminate in which a first oxide film, an Ag film, a sacrificial metal film, and a second oxide film are laminated in this order from the surface side of the first glass plate, The Ag film has a thickness of 6 nm to 10 nm, the sacrificial metal film has a thickness of 0.5 nm to 2.5 nm, and the first oxide film includes a tin oxide film and Al-doped ZnO. The first oxide layer has a thickness of 25 nm or more and 30 nm or less, and the second oxide film is a stack of a tin oxide film and an Al-doped ZnO film. And the second oxide is formed The thickness of the is less than or equal to 40nm ultra-50nm.

  With the above-described configuration, the low radiation multilayer glass of the present invention reflects sunlight well in summer when the incident angle of sunlight is large, and moderately transmits sunlight in winter when the incident angle is small. For this reason, it is possible to reduce the cooling load in summer and further reduce the heating load in winter. As a result, the energy required for cooling and heating can be reduced throughout the year as compared with the low-radiation multilayer glass using the conventional low-radiation laminate. The effect is particularly great when the direct solar radiation component from the sun to the window is large, such as on a high floor of a building.

  In the low emission double-layer glass of the present invention, the materials of the respective films constituting the low emission laminate are preferably combined, and the film thicknesses thereof are also preferably adjusted. For this reason, it is a low radiation multilayer glass having a good color tone.

  Furthermore, in the low radiation multilayer glass of the present invention, the thickness of the Ag film in the low radiation laminated body is thin, and the precious metal material can be saved. Further, the sacrificial metal film is thin, and an expensive metal material can be saved.

  Hereinafter, embodiments of the present invention will be described.

  A cross-sectional view of the low-emission multilayer glass of this embodiment is shown in FIG. The low radiation multilayer glass 1 of the present embodiment is arranged by arranging a first glass plate 11 arranged on the outdoor side and a second glass plate 12 arranged on the indoor side so as to be opposed to each other by providing a space layer 13. Multi-layer glass. The low radiation laminated body 14 is arrange | positioned on the surface (space layer side surface) 11a which opposes the 2nd glass plate 12 in the 1st glass plate 11. FIG. The low radiation laminate 14 is formed by laminating a first oxide film 15, an Ag film 16, a sacrificial metal film 17 and a second oxide film 18 in this order from the surface 11a side of the first glass plate 11. Yes.

  When this low radiation multilayer glass 1 is used for a building, it shall be constructed so that the glass plate surface may be perpendicular to the horizontal direction. Here, the angle of sunlight incident perpendicularly to the glass plate surface of the low emission multilayer glass 1 is defined as 0 degree, and the angle of sunlight incident on the glass sheet surface from the zenith is defined as 90 degrees. The relationship between the low radiation multilayer glass 1 and the incident angle of the sunlight will be described.

  The low radiation multilayer glass 1 of the present embodiment realizes a high reflectance for light incident from an angle close to the zenith (for example, an incident angle of about 70 to 80 degrees), and is perpendicular to the glass plate surface. A high transmittance is realized for light incident from a close angle (for example, an incident angle of about 20 to 40 degrees). In the low radiation multi-layer glass 1, each film constituting the low radiation laminated body 14 is made of a film thickness and a material as will be described later. Therefore, it is possible to realize selectivity that is resistant to reflection and transmission of heat rays depending on the incident angle.

  For example, considering Japan, it is assumed to be used from 26 degrees north latitude (Naha) to 43 degrees north latitude (Sapporo). The height of the sun during the summer solstice ranges from about 82 degrees (Naha) to about 70 degrees (Sapporo). In addition, the altitude of the sun in the winter solstice is in the range of about 40 degrees (Naha) to about 23 degrees (Sapporo).

  When assumed to be used at such mid-latitudes, the low-radiation laminate 14 provided in the low-radiation multilayer glass 1 of the present embodiment reflects well the direct solar radiation component from the sun in the midsummer, and the midwinter. The direct solar radiation component from the sun at the time can be permeated appropriately. Thereby, according to the low radiation | emission multilayer glass 1, the energy required for air conditioning can be decreased throughout the year.

  The present inventor has found that the difference in solar radiation transmittance due to the difference in the incident angle of sunlight in summer and winter is related to the respective film thicknesses of the Ag film 16 and the sacrificial metal film 17, and completed the present invention. I let you. In order to realize the low radiation laminated body 14 having strong selectivity to reflection and transmission of heat rays depending on the incident angle, first, in the present invention, the Ag film 16 that reflects sunlight radiation is formed as thin as possible.

  Specifically, the thickness of the Ag film 16 is 6 nm or more and 10 nm or less. In order to sufficiently reflect sunlight at an incident angle in summer, the lower limit of the thickness of the Ag film 16 is set to 6 nm or more. Moreover, in order to improve the selectivity of transmission and reflection of sunlight with respect to the incident angle of the sun and to ensure good color tone, the upper limit of the thickness of the Ag film is preferably 10 nm or less and preferably less than 8 nm.

  Further, not only the Ag film 16 but also the sacrificial metal film 17 is made as thin as possible. Specifically, the thickness of the sacrificial metal film 17 is set to 0.5 nm to 2.5 nm. In order to ensure the effect of the sacrificial metal film 17, the lower limit of the thickness of the sacrificial metal film is 0.5 nm or more. On the other hand, the upper limit of the thickness of the sacrificial metal film is set to 2.5 nm in order to ensure the effect of saving the expensive metal material constituting the sacrificial metal film.

  As the sacrificial metal film 17, it is preferable to use any one of a Ti film, a Zn—Al alloy film, and a Ni—Cr alloy film.

  With such a configuration, the low radiation multilayer glass 1 can be given high selectivity to the reflection and transmission of heat rays depending on the incident angle.

  When only the thickness of the Ag film is reduced, the color tone of the low radiation multilayer glass 1 changes, so that not only the thickness of the Ag film is reduced, but also the thicknesses of the first oxide film 15 and the second oxide film 18. Need to be optimized. Specifically, the thickness of the first oxide film 15 is 25 nm or more and 30 nm or less, and the thickness of the second oxide film 18 is more than 40 nm and 50 nm or less.

  The first oxide film 15 is formed by laminating a tin oxide film and an Al-doped ZnO film in this order. The second oxide film 18 is formed by laminating an Al-doped ZnO film and a tin oxide film in this order.

  The low radiation multilayer glass 1 can realize a multilayer glass capable of effectively reflecting or transmitting solar energy by including the low radiation laminated body 14 having the above film configuration. Also, the reflection color tone and the transmission color tone are good.

  Furthermore, it is desirable that the thickness of each film constituting the low radiation laminate 14 is appropriately adjusted within the above range to have the following optical characteristics. This optical characteristic is a visible light transmittance, solar transmittance, visible light reflectance, and solar reflectance defined by JIS R 3106. In the low radiation laminate 14, the visible light transmittance and the solar radiation transmittance are at least 57% and 43%, respectively, and the incident angle is 70 degrees to 70 degrees in the range where the incident angle of sunlight is 20 degrees to 40 degrees. It is desirable that both the visible light reflectance and the solar reflectance in the range of 80 degrees are at least 32%.

  By realizing such optical characteristics, energy consumption throughout the year can be reduced more effectively.

As described above, the low radiation multilayer glass 1 of the present embodiment can realize a good color tone. For example, the reflection color tone expressed in the L ^* a ^* b ^* color system viewed from the outdoor side and the indoor side when the low radiation multilayer glass 1 is installed at the boundary between the indoor and the outdoor is a ^* <0, and b ^* <0 is satisfied. In addition, the transmission color tone represented by the L ^* a ^* b ^* color system viewed from the indoor side when the low radiation multilayer glass 1 is installed at the boundary between the outside and the interior is −4.5 <a ^* <3, And -3 <b ^* ≦ 3.

  Moreover, it is desirable for the low radiation multilayer glass 1 of the present embodiment to have a visible light transmittance of 58 to 78% at normal incidence as defined by JIS R 3106.

  In the present embodiment, the glass plate disposed on the outdoor side is the first glass plate in the present invention, and the glass plate disposed on the indoor side is the second glass plate in the present invention. Also good. That is, the low radiation laminated body may be arrange | positioned on the space layer side surface of the glass plate of an indoor side. Moreover, it is also possible to dispose the low-radiation laminate on the space layer side surfaces of both glass plates by regarding both the indoor and outdoor glass plates as the first glass plate.

  Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples.

Example 1
In Example 1, the annual energy consumption when the sunlight incident angle was considered was confirmed about the low radiation | emission multilayer glass of this invention.

First, as Example 1-1, the low radiation multilayer glass of the present invention was produced. Example 1-1 shall have the same structure as the low radiation multilayer glass 1 shown in FIG. 1, and is a first glass plate (hereinafter, for convenience, on the surface of the glass plate) on which a low radiation laminated body is formed. Prepared with a low-emission laminate is referred to as a “low-emission glass plate”). The low radiation laminate used in Example 1-1 was SnO ₂ film (thickness 25.0 nm) / Al-doped ZnO film (thickness 5.0 nm) / Ag from the surface side of a 3 mm thick float glass plate. Film (thickness 7.0 nm) / Zn-Al alloy film (thickness 1.25 nm) / Al-doped ZnO film (thickness 20.0 nm) / SnO ₂ film (thickness 30 nm) formed in this order It is. The SnO ₂ film / Al-doped ZnO film is the first oxide film, and the Al-doped ZnO film / SnO ₂ film is the second oxide film. Each film of the low emission laminate was produced by sputtering. This is specifically shown below.

The float glass plate is placed in an in-line type sputtering apparatus and evacuated until the degree of vacuum is 5 × 10 ⁻⁴ Pa or less. Under the conditions shown in Table 1, the first to sixth layers are formed on the float glass plate surface. A low-emission laminated body that was sequentially laminated was formed. The degree of vacuum after introducing the atmospheric gas was 0.67 Pa in any of the layers. In addition, a stainless steel shield plate having a slit having a width of 1 cm was provided in front of the Zn—Al target for forming the sacrificial metal film in order to limit the film formation rate. The distance between the glass plate and the target was about 65 mm. Regarding the gas flow rate in Table 1, it is 169 × 10 ⁻⁴ Pa · m ³ / s = 1 sccm. In Table 1, a Zn target doped with 11.6% Al by atomic ratio is denoted as Zn-11.6 (at%) Al. In Table 1, Zn-1.33 (at%) Al also has the same meaning.

  The low emission glass plate produced in this way and the 3 mm thick float glass plate are arranged so as to face each other with a 12 mm thick space layer, and the low emission double layer glass of Example 1-1 did.

  In each of the low-radiation multilayer glasses described below, the low-radiation glass plates are arranged in such a direction that the low-radiation laminate is on the space layer side. Furthermore, the multilayer glass described below was configured so that the air layer was 12 mm.

(Comparative Example 1)
Moreover, Comparative Examples 1-1 to 1-4 were produced for comparison.

  As Comparative Example 1-1, a transparent single glass plate was prepared. Specifically, a float glass plate having a thickness of 3 mm was used.

  As Comparative Example 1-2, a transparent multilayer glass was prepared. Specifically, two float glass plates having a thickness of 3 mm were prepared to form a multilayer glass.

As Comparative Example 1-3, a multi-layer glass including a low-emission laminate having a film configuration different from that of the low-emission multilayer glass of the present invention was prepared. Specifically, SnO ₂ film (thickness 18.4 nm) / Al-doped ZnO film (thickness 7.3 nm) / Ag film (thickness 12 nm) is formed on the surface of a float glass plate having a thickness of 3 mm by sputtering. / Zn-Al alloy film (thickness 2.5 nm) / Al-doped ZnO film (thickness 16.6 nm) / SnO ₂ film (60 nm) / Al-doped ZnO film (thickness 7.3 nm) / Ag film (thickness) 12 nm) / Zn—Al alloy film (thickness 2.5 nm) / Al-doped ZnO film (thickness 9.6 nm) / SnO ₂ film (thickness 24 nm) provided in this order is a low-emission laminate. A low emission glass plate was produced. That is, this Ag layer is provided with two Ag films. Using this low radiation glass plate, a low radiation multilayer glass was constructed.

As Comparative Example 1-4, a multi-layer glass provided with a low-emission laminate of the low-emission multilayer glass of the present invention having a low-emission laminate having different film thicknesses was prepared. Specifically, a SnO ₂ film (thickness 25.0 nm) / Al-doped ZnO film (thickness 5.0 nm) / Ag film (thickness 13.) is formed on the surface of a 3 mm thick float glass plate by sputtering. 0 nm) / Zn—Al alloy film (thickness 2.5 nm) / Al-doped ZnO film (thickness 20.0 nm) / SnO ₂ film (thickness 30 nm) is provided in this order, A low emission glass plate was produced. Using this low radiation glass plate, a low radiation multilayer glass was constructed.

  In order to confirm the influence on the amount of energy required for cooling and heating throughout the year when each sample of Example 1-1 and Comparative Examples 1-1 to 1-4 produced as described above is a window glass, The heat load was calculated. Heating load energy (annual heating load) and cooling load energy (annual cooling load) necessary for one year of the house were calculated using a residential heat load calculation program “SMASH for Windows (registered trademark) ver 2.0”. Details of the calculation conditions will be described below.

Detached housing according to the Architectural Institute of Japan standard issue ("Udagawa, Proposal of standard issue Residential standard issue (The 15th Thermal Symposium of the Environmental Engineering Committee of the Architectural Institute of Japan)" (reference material 1)) Calculations were made using the model. In addition, for details such as part specifications of a detached house model, insulation thickness, air conditioning operation method, indoor heat generation schedule, ventilation, etc. ("Energy saving effect by insulation of residential windows-CO by Low-E multi-layer glass" ₂ ) Reduction of emissions-(Results of simulation calculation by SMASH) (Reference material 2)), the weather data of the city where the heat load calculation is performed is “SMASH” issued by the Housing and Building Energy Conservation Organization. From “For Windows (registered trademark) weather data”, the region: IV and the city: Tokyo were selected and calculated.

  For Comparative Examples 1-1 and 1-2, the heat load was calculated when the incident angle of sunlight was 0 degrees. Moreover, about Example 1-1 and Comparative Examples 1-3 and 1-4, the heat load was calculated for two types of incident angles of sunlight of 40 degrees and 75 degrees.

  Moreover, about each sample, the emissivity ((epsilon)) was computed based on JISR3106 using the Fourier-transform infrared spectrophotometer (the JASCO make, Jasco350), and the spectrophotometer (the Hitachi High-Technologies Corporation make, U4100) was used to calculate solar radiation transmittance (τ) and summer and winter solar heat gain (η) based on JIS R 3106.

  Further, the heat transmissivity (U value and K value) was calculated by a method defined in JIS R 3107 using the values such as emissivity calculated above. In addition, for the solar shading coefficient (SCR, SCC), the following calculation formula is used as a value obtained by dividing the radiation component and the convection component of the solar heat acquisition rate by 0.88 which is the solar heat acquisition rate of 3 mm flat glass. Used to calculate. As for the calculation formula, the outdoor / indoor surface heat transfer coefficient described in JIS R 3106 and the corrected emissivity of the plate glass described in JIS R 3107 were used to derive each case in summer and winter.

SCR (summer) = (0.58 × η (summer) + 0.42 × τ) /0.88
SCR (winter) = (0.59 × η (winter) + 0.41 × τ) /0.88
SCC (summer) = 0.42 × (η (summer) −τ) /0.88
SCC (winter) = 0.41 × (η (winter) −τ) /0.88

  Table 2 shows a list of photothermal data acquired to calculate the heat load, and Table 3 shows the result of calculating the heat load.

  In addition, the total value of the heating and cooling loads in summer (June-September) and winter (December-March), where air conditioning is indispensable, is shown in the rightmost column of Table 3. However, about Example 1-1 and Comparative Examples 1-3 and 1-4, the value of 75 degree | times incident in the summer (June-September), the value of 40 degree | times incidence in the winter (December-March), Calculated using each.

  From the results, by using the low radiation multilayer glass of the present invention (Example 1-1), the energy consumption throughout the year is smaller than when Comparative Examples 1-4 is used. That is, it was found that the window opening with the lowest cooling / heating load can be realized.

  Furthermore, the low radiation multilayer glass of the present invention has a simpler film structure than Comparative Example 1-3, and the total film thickness is thinner, and the Ag film and the sacrificial metal film of the low radiation laminate than Comparative Example 1-4. This is a thin configuration. From this, it was found that precious metal materials can be saved.

  From the above results, it was possible to reduce the annual energy consumption by setting each film thickness of the low emission laminate within the film thickness range that is a feature of the present invention.

(Example 2)
In Example 2, a Zn—Al alloy film is used as the sacrificial metal film, and the thickness of the Ag film and the thickness of each of the sacrificial metal film, the first oxide layer, and the second oxide layer are according to the same method as in Example 1. A plurality of samples having different lengths were prepared, and the optical characteristics and color tone of each sample were measured.

  Examples 2-1 to 2-5 and Comparative Examples 2-1 and 2-2 had the same configuration as the low radiation multilayer glass 1 shown in FIG.

  Table 4 shows each film thickness and materials of each film in Examples 2-1 to 2-5 and Comparative Examples 2-1 and 2-2. In addition, Example 2-3 is the same structure as Example 1-1 of Example 1, and Comparative Example 2-2 is the same structure as Comparative Example 1-4 of Example 1.

About each sample, the optical characteristic of the transmittance | permeability, the glass surface reflectance, and the film surface reflectance was measured using the spectrophotometer (Hitachi High-Technologies Corporation make, U4100). From these measurement results, the visible light transmittance and the solar radiation transmittance are calculated based on JIS R 3106, and further, the transmission color tone, film surface reflection color tone and glass surface reflection in the L ^* a ^* b ^* color system based on JIS Z 8722. The color tone was calculated. These results are shown in Table 4.

When the calculation was performed by changing the incident angle every 10 degrees between 0 degrees and 80 degrees, the solar radiation transmittance and the glass surface reflection color tone (a ^* , b ^* ) almost changed in the range of 0 degrees to 40 degrees. However, the value changed when the incident angle exceeded 50 degrees. Table 4 also shows the result of calculating the difference in solar transmittance at an incident angle of 40 degrees and 80 degrees. In Tables 4 to 8, the notation “ZnO: Al” means ZnO doped with Al.

A preferable color tone standard is that the transmitted color tone expressed in the L ^* a ^* b ^* color system is −4.5 <a ^* <3 and −3 <b ^* ≦ 3, and reflection from the outdoor side ( Glass surface reflection) color tone and reflection (film surface reflection) color tone viewed from the indoor side are a ^* <0 and b ^* <0.

  From the results shown in Table 4, the low emission multilayer glass of Examples 2-1 to 2-5, in which the thickness of each film in the low emission laminate matches the range of the characteristics of the present invention, has good optical properties. And tones.

  In these samples, the difference in the solar transmittance at the incident angles of 40 degrees and 80 degrees increases as the thickness of the Ag film and the sacrificial metal film decreases. As a result, it has been found that the selectivity with which sunlight rays can be effectively transmitted and reflected with respect to the incident angle of the sun is enhanced.

(Example 3)
In Example 3, a Ti film is used as the sacrificial metal film, and a plurality of samples having different thicknesses of the Ag film, the sacrificial metal film, and the second oxide layer are prepared, and the optical characteristics and tone of each sample are prepared. Etc. were measured. Examples 3-1 to 3-4 having the same structure as the low-emission multilayer glass of each sample produced in Example 2 except that the film configuration of the low-emission laminate is as shown in Table 5 Comparative Example 3-1 was produced. For each sample, the visible light transmittance, solar transmittance, transmission color tone, film surface reflection color tone, and glass surface reflection color tone were determined in the same manner as in Example 2. These results are also shown in Table 5.

  From the results shown in Table 5, the low emission multilayer glass of Examples 3-1 to 3-4 in which the thickness of each film in the low emission laminate matches the range of the characteristics of the present invention has good optical characteristics. And tones. Further, the relationship between the thicknesses of the Ag film and the sacrificial metal film and the difference in solar transmittance at the incident angles of 40 degrees and 80 degrees was the same tendency as in Example 2.

Example 4
In Example 4, a Ni—Cr alloy film is used as the sacrificial metal film, and a plurality of samples having different thicknesses of the Ag film, the sacrificial metal film, and the second oxide layer are prepared. Characteristics and color tone were measured. Examples 4-1 to 4-4 having the same structure as the low-emission multilayer glass of each sample produced in Example 2 except that the film configuration of the low-emission laminate is as shown in Table 6. Comparative Example 4-1 was produced. For each sample, the visible light transmittance, solar transmittance, transmission color tone, film surface reflection color tone, and glass surface reflection color tone were determined in the same manner as in Example 2. These results are also shown in Table 6.

  From the results shown in Table 6, the low radiation multilayer glass of Examples 4-1 to 4-4 in which the thickness of each film in the low radiation laminate matches the range of the characteristics of the present invention has good optical properties. And tones. Further, the relationship between the thicknesses of the Ag film and the sacrificial metal film and the difference in solar transmittance when the incident angle was 80 degrees and 40 degrees was the same tendency as in Example 2.

(Example 5)
In Example 5, a plurality of samples having different thicknesses of the second oxide film were prepared using a Ti film as the sacrificial metal film of the low radiation stack, and the optical characteristics and color tone of each sample were measured. Examples 5-1 and 5-2 having the same structure as the low-emission multilayer glass of each sample prepared in Example 2, except that the film configuration of the low-emission laminate is as shown in Table 7, and comparison Examples 5-1 to 5-5 were prepared. For each sample, the visible light transmittance, transmission color tone, film surface reflection color tone, and glass surface reflection color tone were determined in the same manner as in Example 2. These results are also shown in Table 7.

When the film thickness of the second oxide film is changed in the range of 35 nm to 65 nm with the film thickness other than the second oxide film fixed, the film thickness is in the range of more than 40 nm and less than 50 nm. Example 5-1) and good optical characteristics and color tone at 50 nm (Example 5-2) (transmission color tone: −4.5 <a ^* <3 and -3 <b ^* ≦ 3, reflection color tone ( Film surface reflection color tone and glass surface reflection color tone): a ^* <0 and b ^* <0).

(Example 6)
In Example 6, a plurality of samples having different thicknesses of the first oxide film were prepared using a Ti film as the sacrificial metal film of the low radiation stack, and the optical characteristics, color tone, and the like of each sample were measured. Examples 6-1 and 6-2 having a structure similar to that of the low-emission multilayer glass of each sample prepared in Example 2 except that the film configuration of the low-emission laminate is as shown in Table 8 and comparison Examples 6-1 to 6-4 were prepared. For each sample, the visible light transmittance, transmission color tone, film surface reflection color tone, and glass surface reflection color tone were determined in the same manner as in Example 2. These results are also shown in Table 8.

When the film thickness of the first oxide film is changed in the range of 15 nm to 40 nm with the film thickness other than the first oxide film fixed, the film thickness is in the range of 25 nm or more and 30 nm or less. Example 6-1) and good optical characteristics and color tone at 30 nm (Example 6-2) (transmission color tone: −4.5 <a ^* <3 and -3 <b ^* ≦ 3, reflection color tone ( Film surface reflection color tone and glass surface reflection color tone): a ^* <0 and b ^* <0).

  The low radiation multilayer glass of the present invention can effectively reflect or transmit solar energy. That is, it transmits a sufficient amount of sunlight when it is cold in winter, and efficiently reflects sunlight with a large incident angle when it is hot in summer. Compared with conventional low-radiation multilayer glass, the cost required for cooling and heating can be reduced throughout the year. For this reason, the low radiation | emission multilayer glass of this invention is used suitably for the window opening part etc. of the high-rise floor of a building where the influence of the direct solar radiation component from the sun to a window is large.

It is sectional drawing which shows an example of a structure of the low radiation | emission multilayer glass of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Low radiation multilayer glass 11 1st glass plate 12 2nd glass plate 13 Spatial layer 14 Low radiation laminated body 15 1st oxide film 16 Ag film 17 Sacrificial metal film 18 2nd oxide film

Claims (9)

A multi-layer glass in which at least the first glass plate and the second glass plate are arranged to face each other,
A low radiation stack in which a first oxide film, an Ag film, a sacrificial metal film, and a second oxide film are stacked in this order from the surface side on the surface of the first glass plate facing the second glass plate. The body is placed,
The thickness of the Ag film is 6 nm or more and 10 nm or less,
The sacrificial metal film has a thickness of 0.5 nm to 2.5 nm,
The first oxide film is formed by laminating a tin oxide film and an Al-doped ZnO film, and the thickness of the first oxide film is 25 nm or more and 30 nm or less,
The second oxide film is formed by laminating a tin oxide film and an Al-doped ZnO film, and the thickness of the second oxide film is more than 40 nm and 50 nm or less.
Low-emission multilayer glass.   The low radiation multilayer glass according to claim 1, wherein the sacrificial metal film is a Ti film, a Zn-Al alloy film, or a Ni-Cr alloy film.   The low emission multilayer glass according to claim 1 or 2, wherein the thickness of the Ag film is 6 nm or more and less than 8 nm. When the incident angle of sunlight incident perpendicularly to the surface of the low radiation laminate is 0 degree,
In the range of the incident angle of 20 degrees to 40 degrees, the solar radiation transmittance specified by JIS R 3106 is at least 43%,
And,
When the incident angle is in the range of 70 degrees to 80 degrees, the solar reflectance defined by JIS R 3106 viewed from the outdoor side when the low-radiation multilayer glass is installed at the indoor / outdoor boundary is at least 32%.
The low radiation multilayer glass of any one of Claims 1-3. When the incident angle of sunlight incident perpendicularly to the surface of the low radiation laminate is 0 degree,
When the incident angle is in the range of 20 degrees to 40 degrees, the visible light transmittance defined by JIS R 3106 is at least 57%,
And,
When the incident angle is in the range of 70 degrees to 80 degrees, the visible light reflectance defined by JIS R 3106 when viewed from the outdoor side when the low radiation multilayer glass is installed at the boundary between the indoor and the outdoor is at least 32%.
The low radiation multilayer glass of any one of Claims 1-4. The reflection color tone represented by the L ^* a ^* b ^* color system viewed from the outdoor side when the low-radiation multilayer glass is installed at the boundary between the outside and the interior is a ^* <0 and b ^* <0. The low radiation multilayer glass according to any one of claims 1 to 5. The reflection color tone represented by the L ^* a ^* b ^* color system when viewed from the indoor side when the low-radiation multilayer glass is installed at the boundary between the outside and the interior is a ^* <0 and b ^* <0. The low radiation multilayer glass according to any one of claims 1 to 6. The transmission color tone represented by the L ^* a ^* b ^* color system viewed from the indoor side when the low-radiation multilayer glass is installed at the boundary between the outside and the interior is −4.5 <a ^* <3, and The low radiation multilayer glass according to claim 1, wherein −3 <b ^* ≦ 3.   The low radiation multilayer glass according to any one of claims 1 to 8, which has a visible light transmittance of 58 to 78% at a normal incidence, as defined by JIS R 3106.

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