AU2016283264B2

AU2016283264B2 - Heat-insulating glass

Info

Publication number: AU2016283264B2
Application number: AU2016283264A
Authority: AU
Inventors: Hiroaki Iwaoka; Yuji Matsui
Original assignee: Asahi Glass Co Ltd
Current assignee: AGC Inc
Priority date: 2015-06-26
Filing date: 2016-06-13
Publication date: 2019-12-12
Anticipated expiration: 2036-06-13
Also published as: MY182764A; JP2017014024A; WO2016208444A1; AU2016283264A1

Abstract

In a heat-insulating glass having a glass plate and a heat-insulating coating film provided on a first surface of the glass plate, the heat-insulating coating film is constructed from three or more layers including a conductive tin oxide-containing layer, the heat-insulating glass has suppressed yellowness and redness, and the heat-insulating glass has a maximum of one location where the sign of the first derivative obtained changes from positive to negative when measured in a state in which the heat-insulating coating film side is brought into contact with an integrating sphere detector and the glass plate side is brought into contact with white paper and in a state in which the glass plate side is brought into contact with an integrating sphere detector and the heat-insulating coating film side is brought into contact with white paper and the spectral reflectance spectrum curve is linearly differentiated in the wavelength range of 380-550 nm.

Description

TITLE OF THE INVENTION

HEAT SHIELDING GLASS

BACKGROUND OF THE INVENTION

1. Field of the Invention

The disclosure herein generally relates to a heat shielding glass provided with a heat shielding film.

2. Description of the Related Art

According to the recent increase in awareness of energy saving, there are more and more examples of application of heat shielding glass having a heat shielding property as window glasses of buildings, glass members of vehicles, or the like.

Such a heat shielding glass is configured, for example, by coating a heat shielding film on one surface of a glass plate.

SUMMARY OF THE INVENTION [Technical Problem]

In recent years, demands for heat shielding effects by heat shielding glasses have greatly increased. Thus, further research and development for a heat shielding film provided with a heat shielding property have been promoted.

Typically, in order to enhance a heat shielding performance of a heat shielding film, it is effective to cause the heat shielding film to have a multilayer structure.

However, when the heat shielding film has the multilayer structure, a problem can occur that due to an unfavorable interference action of light between the used glasses and/or respective layers, a color tone is degraded, controlling a color tone becomes difficult, or the like.

‘ί

-2Particularly, recently, in response to increasing recognition of a sense of beauty by viewers, heat shielding glasses have been required to be provided also with a design effect. For example, recently, as a color tone felt from a heat shielding glass, a red-tinged color, a yellow-tinged color or an ambiguous color tone tends to be avoided.

However, in the case of a multilayer structure of three or more layers for a heat shielding film provided on a heat shielding glass, it becomes more difficult to control the color tone, and it becomes difficult to obtain a desired color tone and obtain a desired sense of beauty.

The present invention was made in view of such a problem, and it is an object of the present invention to provide a heat shielding glass having a desirable design effect and an excellent heat shielding property.

[Solution to Problem] .

According to an aspect of the present invention, a heat shielding glass includes a glass plate having a first surface and a second surface opposite to each other; and a heat shielding film provided on the first surface of the glass plate, the heat shielding film being configured of three or more layers including a conductive tin oxide containing layer, both yellowness indices Yl E313 of a reflection color Cf from the heat shielding film side and a reflection color C_g from the glass plate side being less than -5, values of a color coordinate a* of the reflection color Cf from the heat shielding film side and of the reflection color C_g from the glass plate side ‘1

-3expressed by the CIE 1976 L*:a*:b* color coordinate system being negative, at most one location existing where a sign of a first first-order differential value Bl changes from positive to negative, the first first-order differential value Bl being obtained by first-order differentiation of a curve of a first spectroscopic reflection spectrum within a range of a wavelength of 380 nm to 550 nm, the first spectroscopic reflection spectrum being measured in a state where the heat shielding glass is brought into contact with an integrating sphere detector on the heat shielding film side, and brought into contact with a sheet of white paper on the glass plate side, and at most one location existing where a sign of a second first-order differential value B2 changes from positive to negative, the second first-order differential value B2 being obtained by first-order differentiation of a curve of a second spectroscopic reflection spectrum within a range of a wavelength of 380 nm to 550 nm, the second spectroscopic reflection spectrum being measured in a state where the heat shielding glass is brought into contact with the integrating sphere detector on the glass plate side, and brought into contact with the sheet of white paper on the heat shielding film side.

[Advantageous effect of Invention]

According to an aspect of the present invention, a heat shielding glass having a desirable design effect and an excellent heat shielding property can be provided. BRIEF DESCRIPTION OF THE DRAWINGS [FIGURE 1]

FIG. 1 is a diagram schematically depicting a

-4configuration of an apparatus for evaluating a dull effect received from a heat shielding glass.

[FIGURE 2]

FIG. 2 is a diagram schematically depicting an example of an operation of determining a number of peaks included in a spectrum waveform of a reflectance R of the heat shielding glass.

[FIGURE 3]

FIG. 3 is a diagram schematically depicting another example of the operation of determining a number of peaks included in a spectrum waveform of a reflectance R of the heat shielding glass.

[FIGURE 4]

FIG. 4 is a cross-sectional diagram schematically depicting an example of a configuration of a heat shielding glass according to an embodiment of the invention.

[FIGURE 5]

FIG. 5 is a diagram schematically depicting an example of a configuration of a heat shielding film.

[FIGURE 6]

FIG. 6 is a diagram schematically depicting another example of the configuration of the heat shielding film.

[FIGURE 7]

FIG. 7 is a diagram schematically depicting yet another example of the configuration of the heat shielding film.

[FIGURE 8]

FIG. 8 is a diagram schematically depicting still another example of the configuration of the heat shielding film.

[FIGURE 9]

-5FIG. 9 is a diagram depicting an example of a spectrum waveform of a reflected light, obtained in the heat shielding glass according to Example 1.

[FIGURE 10]

FIG. 10 is a diagram depicting an example of a spectrum waveform of a reflected light, obtained in the heat shielding glass according to Example 3.

[FIGURE 11]

FIG. 11 is a diagram depicting an example of a spectrum waveform of a reflected light, obtained in the heat shielding glass according to Example 8.

[FIGURE 12]

FIG. 12 is a diagram depicting an example of a spectrum waveform of a reflected light, obtained in the heat shielding glass according to Example 10.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the following, with reference to drawings, an embodiment of the present invention will be described.

In the present invention, a heat shielding glass including a glass plate having a first surface and a second surface opposite to each other; and a heat shielding film provided on the first surface of the glass plate, the heat shielding film being configured of three or more layers including a conductive tin oxide containing layer, both yellowness indices Yl E313 of a reflection color C_f from the heat shielding film side and of a reflection color C_g from the glass plate side being less than -5, values of a color coordinate a* of the

-6reflection color C_f from the heat shielding film side and of the reflection color C_g from the glass plate side expressed by the CIE 1976 L*:a*:b* color coordinate system being negative, at most one location existing where a sign of a first first-order differential value Bl changes from positive to negative, the first first-order differential value Bl being obtained by first-order differentiation of a curve of a first spectroscopic reflection spectrum within a range of a wavelength of 380 nm to 550 nm, the first spectroscopic reflection spectrum being measured in a state where the heat shielding glass is brought into contact with an integrating sphere detector on the heat shielding film side, and brought into contact with a sheet of white paper on the glass plate side, and at most one location existing where a sign of a second first-order differential value B2 changes from positive to negative, the second first-order differential value B2 being obtained by first-order differentiation of a curve of a second spectroscopic reflection spectrum within a range of a wavelength of 380 nm to 550 nm, the second spectroscopic reflection spectrum being measured in a state where the heat shielding glass is brought into contact with the integrating sphere detector on the glass plate side, and brought into contact with the sheet of white paper on the heat shielding film side, is provided.

As described above, in a heat shielding glass configured by coating a heat shielding film on a glass plate, in the case where the heat shielding film has a multilayer structure, a problem often occurs that due to an unfavorable interference action of light between the used glasses and/or respective layers configuring the heat shielding film, a color tone is degraded or controlling a

WWXWU

-7color tone becomes difficult. With the continuing increase in sensitivity to design effects, such a problem can become more prominent hereinafter.

However, with respect to the heat shielding glass according to the present invention, an excellent color tone and a clean impression can be provided, despite the heat shielding film being configured of three or more layers. More specifically, in the heat shielding glass according to the invention, redness or yellowness included in a reflected light is significantly controlled. Because a viewer is not liable to feel a sense of discomfort and a mixing of a plurality of colors is significantly controlled, a clear impression can be provided without a dull effect.

In the· present application, in order to evaluate quantitatively the redness and yellowness contained in a reflected light from the heat shielding glass, and a dull effect (index opposite to clear effect) received from the heat shielding glass, the following indices will be employed.

(Redness of color contained in reflected light) A redness of color contained in a reflection color from the heat shielding glass can be evaluated by measuring a reflection color of the heat shielding glass using a typical spectrometer. More specifically, the redness of color can be evaluated by calculating the CIE 1976 L*:a*:b* color coordinate system based on a spectroscopic spectrum measured by a measuring apparatus having an integrating sphere detector. With respect to a method of measuring, the heat shielding glass is arranged for the measuring apparatus so that the heat shielding film of the heat shielding glass is on the integrating · sphere detector side, and the reflection spectrum is

-8measured. Alternatively, the heat shielding glass is arranged for the measuring apparatus so that the glass surface of the heat shielding glass is on the integrating sphere detector side, and the reflection spectrum is measured.

Based on the measured reflection spectrum, the CIE 1976 L*:a*:b* color coordinate system will be calculated. In the color coordinate system, when the color coordinate of reflection color is a*>0, the reflection color from the heat shielding glass is determined to have redness. When the color coordinate is a*<0, the reflection color from the heat shielding glass is determined not to have redness.

(Yellowness of color contained in reflected light)

A yellowness of color contained in a reflection color from the heat shielding glass can be evaluated as a yellowness index Yl E313 in conformity with ASTM E131 standards from chromaticity in conformity with JIS Z7701:1990. The evaluation is performed by calculating the yellowness index Yl E313 for both the reflection color obtained from the heat shielding film side of the heat shielding glass (referred to as a reflection color C_f) and the reflection color obtained from the glass plate side of the heat shielding glass (referred to as a reflection color C_g) .

As a result, for both of C_f and C_g, when the yellowness index Yl E313 is less than -5, the reflection color from the heat shielding glass is determined not to have yellowness. Moreover, in at least one of C_f and C_g, when the yellowness index Yl E313 is greater than or equal to -5, the reflection color from the heat shielding glass is determined to have yellowness.

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-9(Dull effect of heat shielding glass)

In determining a color tone of a heat shielding glass, in many cases, the glass is placed on a sheet of white paper and an observer views the glass from the front.

A light viewed in this observation method is a superposition of a component of an incident light going through the glass that is reflected at a surface of a sheet of paper, and components reflected at a front surface and a rear surface of the glass including the coating. The inventors of the present application have invented a method of evaluating a dull effect by using a measurement spectrum of reflectance based on the abovedescribed observation method.

The dull effect received from the heat shielding glass will be evaluated using the reflection spectrum contained in the reflected light from the heat shielding glass, as follows:

FIG. 1 schematically illustrates a configuration of an apparatus for evaluating a dull effect received from 20 the heat shielding glass.

As illustrated in FIG. 1, the apparatus 1 includes an integrating sphere detector 5 and a sheet of white paper 30. For the white paper 30, a high quality paper having a reflectance of about 80% (e.g. Multi Cut

Paper White PPCA4XW by TOPPAN FORMS Co., Ltd.) is used.

When a dull effect of the heat shielding glass is measured, a sample 10 of the heat shielding glass that will be evaluated is arranged in an apparatus 1.

In the first evaluation, as illustrated in FIG.

1, the sample 10 is arranged so that the glass plate 12 is on the paper 30 side, and the heat shielding film 15 is on the integration sphere detector 5 side.

In the first evaluation, the sample 10 is

-10irradiated with light emitted from an incident port 6 of the integration sphere detector 5 with a range of angle of 8°, and the reflectance Rf of the sample 10 is measured.

From a waveform of the reflectance R_f, obtained as above, a dull effect is evaluated. Specifically, in the spectrum waveform of the reflectance R_f in a range of wavelength of 380 nm to 540 nm, when at most only one peak exists, the sample 10 viewed from the heat shielding film 15 is determined not to have a dull effect. When two or more peaks exist, the sample 10 viewed from the heat shielding film 15 is determined to have a dull effect.

Ά dull effect is determined in this way based on the tendency that human eyes feel a dull effect more in the case where two or more colors are mixed in a spectroscopic waveform as compared with a monochromatic light.

Next, a second evaluation is performed. In the second evaluation, the sample 10 is arranged in the apparatus 1, with the front surface and rear surface of the sample 10 being reversed. That is, the sample 10 is arranged so that the glass plate 12 is on the integration sphere detector 5 side, and the heat shielding film 15 is on the sheet of paper 30 side.

In the second evaluation, the same measurement is performed as the first evaluation, i.e. reflectance Rg of the sample 10 is measured. In the spectrum waveform of the reflectance obtained as above, when at most only one peak exists, the sample 10 viewed from the glass plate 12 is determined not to have a dull effect. When two or more peaks exist, the sample 10 viewed from the glass plate 12 is determined to have a dull effect.

As a result, in the first evaluation and the second evaluation, when at most only one peak exists, the

-11sample 10 is determined not to have a dull effect (i.e.

determined to have a clear effect).

Note that because various forms exist for the spectrum waveforms of the reflectance R_f and R_g, obtained by the above measurement, it may be often difficult to determine the number of peaks. In the present application, the number of peaks will be determined based on a change in a first-order differential value of the spectrum waveform of the measured reflectance R_f and Rg. In the following, the operation will be described with reference to FIG. 2 and FIG. 3.

FIG. 2 and FIG. 3 illustrate an example of an operation of determining a number of peaks contained in a spectrum waveform of a reflectance R.

As illustrated in a part (a) in FIG. 2, the spectrum waveform S of the reflectance R is assumed to have a single peak Pl. In this case, a first-order differential value B of the spectrum waveform S has a waveform as approximately illustrated in a part (b) in FIG.

2.

That is, the first-order differential value B shows behaviors illustrated in region (i) to region- (iii), from the small wavelength λ side. In the first region (i), the first-order differential value B monotonically increases with the wavelength λ. In the next region (ii), the first-order differential value B monotonically decreases with the wavelength λ, and changes from a positive value to a negative value. In the next region (iii), the first-order differential value suddenly changes to monotonically increasing with the wavelength λ. In this case, only one location Q exists where the firstorder differential value B changes from a positive value to a negative value (a location where B varies from B>0 to

-12Β<0 through the point Β=0).

Next, as illustrated in a part (a) in FIG. 3, the spectrum waveform S of the reflectance R is assumed to have two peaks Pl and P2. In this case, a first-order differential value B of the spectrum waveform S has a waveform as approximately illustrated in a part (b) in FIG. 3.

That is, the first-order differential value B shows behaviors illustrated in region (i) to region (v), from the small wavelength λ side. In the first region (i), the first-order differential value B monotonically increases with the wavelength λ. In the next region (ii) , the first-order differential value B monotonically decreases with the wavelength λ, and changes from a positive value to a negative value. In the next region (iii), the first-order differential value suddenly changes to monotonically increasing with the wavelength λ. In the next region (iv), the first-order differential value monotonically decreases again with the wavelength λ, and changes from a positive value to a negative value. In the next region (v), the first-order differential value begins to monotonically increase with the wavelength λ again. In this case, two locations Q exist where the first-order differential value B changes from a positive value to a negative value (a location where B varies from B>0 to B<0 through the point B=0).

In this way, it is found that the number of peaks contained in the spectrum waveform S of the reflectance R can be determined by the number of locations Q where the first-order differential value B changes from a positive value to a negative value.

In addition, in the above-described operation, in order to exclude small fluctuations in the first-order

-13differential values B due to errors, the minimum pitch of the wavelength λ is set to 5 nm.

In the present application, in the respective spectrum waveforms of the reflectance Rf and R_g obtained by the above-described apparatus 1 for measuring a dull effect, in the case where the number of locations Q where the first-order differential value B changes from a positive value to a negative value is less than or equal to one, the spectrum waveform is determined not to include a peak or to include only one peak, and the heat shielding glass is determined not to have a dull effect. In the case where the number of locations Q where the first-order differential value B changes from a positive value to a negative value is greater than or equal to two, the spectrum waveform is determined to include two or more peaks, and the heat shielding glass is determined to have a dull effect.

According to the above-described method, a dull effect in the heat shielding glass can be determined quantitatively.

(Heat shielding glass according to embodiment)

Next, with reference to FIG. 4, an example of a configuration of the heat shielding glass according to the embodiment of the present invention will be specifically described.

FIG. 4 specifically illustrates a cross-section of the heat shielding glass according to the embodiment (in the following, referred to as a first heat shielding glass).

. As illustrated in FIG. 4, the first heat shielding glass 100 includes a glass plate 110, and a heat shielding film 130. The glass plate 110 has a first surface 112 and a second surface 114. The heat shielding

-14film 130 is arranged on the first surface 112 side of the glass plate 110.

The heat shielding film 130 is configured of at least three layers including a conductive tin oxide containing layer. For example, FIG. 4 illustrates the heat shielding film 130 having three layers, from a first layer 140 to a third layer 150. A conductive tin oxide containing layer is formed as a second layer 145.

The conductive tin oxide containing layer refers to a conductive layer including tin oxide of 50 wt% or more.

The first heat shielding glass 100 has the above-described feature, i.e.

both of the yellowness index Yl E313 of the reflection color C_f from the heat shielding film 130 side and of the reflection color C_g from the glass plate 110 side are less than -5, color coordinates of the reflection color Cf from the heat shielding film 130 side and of the reflection color C_g from the glass substrate 110 side, indicated by the CIE 1976 L*:a*:b* color coordinate system are a*<0, and at most one location exists where a sign of a first-order differential value B changes from positive to negative, in both of spectroscopic reflection spectrum curves within a range of a wavelength of 380 nm to 550 nm, measured from the glass plate 110 side and from the heat shielding coating layer 130 side.

In the first heat shielding glass 100, redness and yellowness of color contained in the reflection color are controlled against and a dull effect can be controlled against. For the first heat shielding glass 100, a viewer is not liable to feel a sense of discomfort, and a clear

-15impression can be provided without a dull effect.

Moreover, in the first heat shielding glass 100, the heat shielding film 130 is configured of at least three layers including a conductive tin oxide containing layer 145. Thus, the first heat shielding glass 100 can exert an excellent heat shielding performance and an excellent durability performance.

(Heat shielding performance of heat shielding glass)

Typically, the heat shielding performance of a heat shielding glass can be expressed by the following formula (1):

SC = g-value / 0.88. formula (1)

In the formula (1), g-value is a solar radiation heat reception rate, which is expressed as a percentage, with respect to an entirety of solar heat incident from one side of the heat shielding glass (first side), of a sum of heat directly transmitted to the other side (second side) (transmission heat) and of heat absorbed inside the heat shielding glass and afterwards emitted to the second side. Moreover, SC is a shielding coefficient. The gvalue can be measured in conformity with ISO 9050: 2003.

In the first heat shielding glass 100, the shielding coefficient SC is more preferably less than 0.7, and particularly preferably, the SC is less than 0.6.

(Respective members configuring heat shielding glass)

Next, respective members configuring the first heat shielding glass 100 having the above-described features will be described in detail. In the following descriptions, when indicating the respective members, for

-16clarification, the reference numerals used in FIG. 4 will be used.

(Glass plate 110)

A glass plate 110 may be, for example, configured of a soda lime glass, a borosilicate glass, an alkali-free glass, or an aluminosilicate glass.

Moreover, the glass plate 110 may be transparent or may be colored. A color of the glass plate 110 is not particularly limited. The glass plate 110 may be green or blue, for example.

A thickness of the glass plate 110 is not particularly limited. The thickness falls, for example, within a range of 2 mm to 12 mm. When the glass plate 110 is a strengthened glass, particularly a chemically strengthened glass, a plate thickness can be made smaller, and it is preferable.

(Heat shielding film 130)

A heat shielding film 130 is configured of three or more layers including a conductive tin oxide containing layer.

In the following, with reference to FIGS. 5 to 8, some configuration examples of the heat shielding film 130 will be described. However, they are merely examples, and the heat shielding film 130 may have another configuration.

(Configuration example 1 of heat shielding film: first heat shielding film)

FIG. 5 schematically illustrates a first configuration example of a heat shielding film.

As illustrated in FIG. 5, in the configuration, the first heat shielding film 530 is configured of three layers: an undercoat layer 540, a conductive tin oxide containing layer 545 and a high refractive index layer 550. The high refractive index layer collectively means a .8H&aai£i»>tauadaai^^

-17layer with a refractive index greater than two.

The undercoat layer 540 has a role of preventing specified elements from diffusing to each other between the glass plate 110 and the conductive tin oxide containing layer 545. Moreover, the undercoat layer 540 reduces an incident light reflection at an interface between the undercoat layer 540 and the conductive tin oxide containing layer 545. According to the abovedescribed feature, it is possible to control an in-plane distribution of a reflection color caused by a film thickness distribution of the conductive tin oxide containing layer. The undercoat layer 540 is configured of, for example, a material mainly including silica or a material mainly including tin oxide. In the present application, the phrase layer mainly includes material Ά' means that the intended layer includes a material Ά' of 50 mass% or more.

The undercoat layer 540 may be a silicon oxide (SiO_x) .

A thickness of the undercoat layer 540 falls within a range of 10 nm to 100 nm, for example.

The conductive tin oxide containing layer 545 may be configured of tin oxide in which antimony or fluorine is doped. With respect to a doping amount of antimony, a ratio by weight of antimony to tin, Sb/Sn, measured by, for example, an X-ray fluorescence analysis (XRF) preferably falls within a range of 0.0 to 0.1, more preferably within a range of 0.02 to 0.06, and further preferably within a range of 0.03 to 0.05.

A thickness of the conductive tin oxide containing layer 545 falls preferably, for example, within a range of 50 nm to 500 nm, more preferably within a range of 150 nm to 350 nm, and further preferably within a range

-18of 200 nm to 280 nm.

The high refractive index layer 550 has a role of adjusting a reflection characteristic of light entering the heat shielding film 530. The high refractive index layer 550 may be configured of, for example, titanium oxide.

A thickness of the high refractive index layer falls preferably, for example, within a range of 10 nm to 70 nm, more preferably within a range of 20 nm to 50 nm, and further preferably within a range of 35 nm to 45 nm.

A total thickness of the first heat shielding film 530 falls, for example, within a range of 70 nm to 670 nm, preferably within a range of 100 nm to 500 nm, more preferably within a range of 200 nm to 450 nm, and further preferably within a range of 300 nm to 400 nm.

A method of forming the first heat shielding film 530 is not particularly limited. The first heat shielding film 530 is configured, for example, by serially depositing the respective layers using a method selected from a physical deposition method (e.g. a vacuum deposition method, an ion plating method, and a sputtering method), a chemical deposition method (e.g. thermal CVD method, a plasma CVD method, and an optical CVD method), and an ion beam sputtering method.

Alternatively, the first heat shielding film 530 may be formed, for example, using an online CVD method.

The term online (deposition method) means a method in which a film is deposited on a surface of a glass during a manufacturing process of the glass. More specifically, upon manufacturing the glass, a glass ribbon moves on a molten tin bath and is slowly cooled, and thereby glass is continuously manufactured. In the online (deposition method), while a glass ribbon is

-19moving, a film is deposited on an upper surface of the glass ribbon. That is, in the online (deposition method), the manufacturing process of glass and the deposition process of film are performed consecutively.

In the case where the first heat shielding film 530 is formed using the online CVD method, a manufacturing cost can be reduced and it is preferable.

(Configuration example 2 of heat shielding film: second heat shielding film)

FIG. 6 schematically illustrates a second configuration example of a heat shielding film.

As illustrated in FIG. 6, in the configuration, the second heat shielding film 630 is configured of four layers: a first undercoat layer 640, a second undercoat layer 641, a conductive tin oxide containing layer 645 and a high refractive index layer 650.

When such a plurality of uhdercoat layers 640, 641 are applied to the second heat shielding film 630, it is possible to reduce a reflection of incident light at an interface between the undercoat layer 641 and the conductive tin oxide containing layer 645. According to the above-described feature, it is possible to control an in-plane distribution of a reflection color caused by a film thickness distribution of the conductive tin oxide containing layer.

For the first undercoat layer 640 and the second undercoat layer 641, a tin oxide containing layer and a silicon oxide (SiC>2) layer can be used, respectively. Moreover, a thickness of the first undercoat layer 640 falls, for example, within a range of 10 nm to 50 nm. A thickness of the second undercoat layer 641 falls, for example, within a range of 25 nm to 50 nm.

Note that in the second heat shielding film 630,

-20with respect to the configurations of the conductive tin oxide containing layer 645 and the high refractive index layer 650, the descriptions regarding the above-described first heat shielding film 530 can be referred, and descriptions regarding the configurations of the conductive tin oxide containing layer and the high refractive index layer will be omitted.

(Configuration example 3 of heat shielding film: third heat shielding film)

FIG. 7 schematically illustrates a third configuration example of a heat shielding film.

As illustrated in FIG. 7, in the configuration, the third heat shielding film 730 is configured of four layers: a first undercoat layer 740, a second undercoat layer 741, a first conductive tin oxide containing layer 745 and a second conductive tin oxide containing layer 746.

For the first conductive tin oxide containing layer 745 and the second conductive tin oxide containing layer 746, the same material as the conductive tin oxide containing layer 545 of the first heat shielding film 530 can be used. For example, the first conductive tin oxide containing layer 745 may be configured of antimony doped tin oxide and the second conductive tin oxide containing layer 746 may be configured of fluorine doped tin oxide. Alternatively, the first conductive tin oxide containing layer 745 may be configured of fluorine doped tin oxide and the second conductive tin oxide containing layer 746 may be configured of antimony doped tin oxide.

Moreover, a thickness of the first conductive tin oxide containing layer 745 falls within, for example, a range of 110 nm to 210 nm, and a thickness of the second conductive tin oxide containing layer 746 falls within, for example, a range of 160 nm to 300 nm. In the case

-21where the first conductive tin oxide containing layer 745 is antimony doped tin oxide and the second conductive tin oxide containing layer 746 is fluorine doped tin oxide, a boundary between the layers may not be clearly identifiable merely because the doped element is different. In this case, a layer including a layer in which antimony is doped and a layer in which fluorine is doped and with a total thickness falling within a range of 270 nm to 510 nm can be regarded as laminated layers of a layer of antimony doped tin oxide and a layer of fluorine doped tin oxide.

Note that in the third heat shielding film 730, for configurations of the first undercoat layer 740 and the second undercoat layer 741, the description regarding the second heat shielding film 630 can be referred to. A tin oxide containing layer and a silicon oxide (S1O2) containing layer can be used for the first and second undercoat layers 740, 741, respectively. A thickness of the first undercoat layer 740 falls within, for example, a range of 10 nm to 50 nm, and a thickness of the second undercoat layer 741 falls within, for example, a range of 25 nm to 50 nm.

(Configuration example 4 of heat shielding film: fourth heat shielding film)

FIG. 8 schematically illustrates a fourth configuration example of a heat shielding film.

As illustrated in FIG. 8, in the configuration, the fourth heat shielding film 830 is configured of three layers of an undercoat layer 840, a first conductive tin oxide containing layer 845 and a second conductive tin oxide containing layer 846.

For a configuration of the undercoat layer 840, the description regarding the first heat shielding film 530 can be referred to. Moreover, for configurations of

-22the first conductive tin oxide containing layer 845 and the second conductive tin oxide containing layer 846, the description regarding the third heat shielding film 730 can be referred to.

In this way, the heat shielding film 130 can be implemented combining various configurations, such as a three layer configuration or a four layer configuration.

Note that, the heat shielding glass according to the embodiment preferably has a haze value of less than 0.8%. It is considered to be important to enhance a flatness of a surface of the conductive tin oxide layer in order to reduce the haze value. A method of enhancing the flatness of the surface of the conductive tin oxide layer is, for example, maintaining a deposition temperature for the conductive tin oxide layer low as possible so as to prevent crystal grains of conductive tin oxide from becoming enlarged, to configure the conductive tin oxide layer of uniform and fine grains.

EXAMPLE

In the following, practical examples of the present invention will be described. Note that, in the following descriptions, Examples 1 to 6 are practical examples, and Examples 7 to 14 are comparative examples.

(Example 1)

According to the following method, a heat shielding glass was manufactured.

First, using a CVD method under atmospheric pressure, on a surface of a glass plate, a heat shielding film was formed.

A configuration of the heat shielding film was the three layer structure as illustrated in FIG. 5. The undercoat layer was a SiO_x layer (target thickness was 55 ;'A

-23nm) . The conductive tin oxide containing layer was an antimony doped tin oxide layer (target thickness was 260 nm) . The high refractive index layer was a titanium oxide layer (target thickness was 40 nm).

A temperature of a glass plate upon depositing the SiO_x layer was about 670 °C. Moreover, the antimony doped tin oxide layer was deposited at about 590 °C, using a raw material gas obtained by diluting with air a mixed gas that was obtained by evaporating raw materials of monobutyl tin chloride (MBTC), water and antimony trichloride (SbCl₃) . Furthermore, the titanium oxide layer was deposited at about 540 °C, using a raw material obtained by diluting with nitrogen a mixed gas that was obtained by evaporating raw materials of titanium tetra isopropoxide (TTIP) and MBTC.

By cooling and cutting the glass plate after depositing the heat shielding film, a heat shielding glass including a glass plate (transparent color) having a dimension of 300 mm (vertical) x 300 mm (horizontal) x 5 mm (thickness) was manufactured (in the following, referred to as a heat shielding glass according to Example 1) · (Examples 2 to 6)

Using the same method as Example 1, heat shielding glasses (in the following, referred to as heat shielding glasses according to Examples 2 to 6) were manufactured. In Examples 2 to 6, a different type (color) of glass plate from Example 1 was used. Moreover, a thickness of the glass plate was changed from that of Example 1.

(Example 7)

Using the same method as Example 1, a heat shielding glass (in the following, referred to as a heat

-24shielding glass according to Example 7) was manufactured. In Example 7, for the heat shielding film, a film of a four layer configuration illustrated in FIG. 7 was used. The first undercoat layer was a SnO₂ layer with a thickness of 19 nm, and the second undercoat layer was a SiO₂ layer with a thickness of 38 nm. Moreover, the first conductive tin oxide containing layer was an antimony doped tin oxide layer with a thickness of 162 nm, and the second conductive tin oxide containing layer was a fluorine doped tin oxide layer with a thickness of 230 nm.

Moreover, in Example 7, for the glass plate a transparent sheet glass with a thickness of 6 mm was used.

(Examples 8 to 10)

Using the same method as Example 7, heat shielding glasses (in the following, referred to as heat shielding glasses according to Examples 8 to 10) were manufactured. In Examples 8 to 10, a different type (color) of glass plate from Example 7 was used. Moreover, a thickness of the glass plate was changed from that of Example 7.

(Example 11)

Using the same method as Example 1, a heat shielding glass (in the following, referred to as a heat shielding glass according to Example 11) was manufactured. In Example 11, for the heat shielding film, a film of a four layer configuration illustrated in FIG. 6 was used. The first undercoat layer was a SnO₂ layer with a thickness of 19 nm, and the second undercoat layer was a SiO₂ layer with a thickness of 38 nm. The conductive tin oxide containing layer was a fluorine doped tin oxide layer with a thickness of 260 nm. The high refractive index layer was a titanium oxide layer with a thickness of 37 nm.

-25(Example 12)

Using the same method as Example 11, a heat shielding glass (in the following, referred to as a heat shielding glass according to Example 12) was manufactured. In Example 12, for the glass plate, a glass colored green with a thickness of 6 mm (Green glass with high heat shielding performance) was used.

(Example 13)

Using the same method as Example 1, a heat shielding glass (in the following, referred to as a heat shielding glass according to Example 13) was manufactured. In Example 13, for the heat shielding film, a film of a three layer configuration illustrated in FIG. 5 was used. The undercoat layer was a SnC>2 layer with a thickness of 55 nm. The conductive tin oxide containing layer was an antimony doped tin oxide layer with a thickness of 310 nm. The high refractive index layer was a titanium oxide layer with a thickness of 40 nm.

(Example 14)

Using the same method as Example 13, a heat shielding glass (in the following, referred to as a heat shielding glass according to Example 14) was manufactured. In Example 14, for the glass plate, a glass colored bluegreen with a thickness of 6 mm (BNFL) was used.

TABLE 1, in the following, shows the configurations of the heat shielding glasses according to Examples 1 to 14 as a whole.

[TABLE 1]

Exam pie	glass plate (thickness)	configuration of heat shielding coating layer
1	clear colorless (5 mm)	SiO_x layer (55 nm) + Sb doped tin oxide layer (260 nm) + titania layer (40 nm)

2	green (6 mm)	SiO_x layer (55 nm) + Sb doped tin oxide layer (260 nm) + titania layer (40 nm)
		SiOx layer (55 nm) + Sb doped tin oxide layer (260 nm)
3	green (8 mm)	+titania layer (40 nm)
4	blue-green (8 mm)	SiO_x layer (55 nm) + Sb doped tin oxide layer (260 nm) + titania layer (40 nm)
5	gray (8 mm)	SiO_x layer (55 nm) + Sb doped tin oxide layer (260 nm) + titania layer (40 nm)
6	rich blue (8 mm)	SiO_x layer (55 nm) + Sb doped tin oxide layer (260 nm) + titania layer (40 nm)
7	clear colorless (6 mm)	SnO₂ layer (19 nm) + SiO₂ layer (38 nm) + Sb doped tin oxide layer (162 nm) + F doped tin oxide layer (230 nm)
8	green (6 mm)	SnOz layer (19 nm) + SiO₂ layer (38 nm) + Sb doped tin oxide layer (162 nm) + F doped tin oxide layer (230 nm)
9	clear colorless (6 mm)	SnO2 layer (19 nm) + SiO₂ layer (38 nm) + Sb doped tin oxide layer (162 nm) + F doped tin oxide layer (230 nm)
10	clear colorless (6 mm)	SnO2 layer (19 nm) + SiO₂ layer (38 nm) + Sb doped tin oxide layer (162 nm) + F doped tin oxide layer (230 nm)
11	clear colorless (6 mm)	SnOz layer (19 nm) + SiO₂ layer (38 nm) + F doped tin oxide layer (260 nm) + titania layer (37 nm)
12	green (6 mm)	SnO₂ layer (19 nm) + SiO₂ layer (38 nm) + F doped tin oxide layer (260 nm) + titania layer (37 nm)
13	clear colorless (5 mm)	SnO₂ layer (55 nm) + Sb doped tin oxide layer (310 nm) + titania layer (40 nm)
14	blue-green (6 mm)	SnCh layer (55 nm) + Sb doped tin oxide layer (310 nm) + titania layer (40 nm)

(Evaluation)

Using the respective heat shielding glasses, described as above, the following evaluation was performed.

(Evaluation of heat shielding performance)

For the respective heat shielding glasses, a spectroscopic measurement was performed using a spectral photometer Lambda 950 by Perkin Elmer Co., Ltd., and a shielding coefficient was calculated using a method in 10 conformity with ISO 9050:2003.

Note that this measurement was performed by irradiating the heat shielding glass with light emitted from the glass plate side of the heat shielding glass (i.e. a side opposite to the heat shielding film) .

-27In the shielding coefficient SC column in

TABLE 2, values of the shielding coefficient SC obtained for the respective heat shielding glasses are shown as a whole.

[TABLE 2]

Exam pie	shielding coefficient SC	number of peaks	duh effect	redness in reflection color a*	redness	YIE313	yellown ess	overall determin ation
Rq	R_f	c.	c_f	Cg	c_f
1	0.55	1	1	no	-0.9	-0.2	no	-9.0	-11.3	no	OK
2	0.38	1	1	no	-8.8	-3.1	no	-13.2	-13.2	no	OK
3	0.36	1	1	no	-8.8	-2.2	no	-12.5	-12.9	no	OK
4	0.35	1	1	no	-6.4	-1.8	no	-30.4	-11.9	no	OK
5	0.34	1	1	no	-0.9	-2.1	no	-7.8	-13.2	no	OK
6	0.37	1	1	no	-3.8	-2.5	no	-52.6	-17.1	no	OK
7	0.61	2	2	yes	-3.6	-0.8	no	-8.8	13.2	yes	NG
8	0.38	1	2	yes	-4.1	-3.7	no	-1.9	8.7	yes	NG
9	0.61	2	2	yes	-3.7	-2.7	no	-17.4	1.1	yes	NG
10	0.56	2	2	yes	-7.9	-11.3	no	-23.3	-4.6	yes	NG
11	0.72	1	1	no	-3.2	-1.7	no	-3.7	-12.5	yes	NG
12	0.40	1	1	no	-10.5	-2.6	no	-0.1	-6.3	yes	NG
13	0.61	2	2	yes	1.4	3.9	yes	10.4	-0.9	yes	NG
14	0.40	2	2	yes	-5.5	0.5	yes	-19.4	-9.7	no	NG

From the results, it was found that in the heat shielding glasses according to Examples 1 to 6, the values of the shielding coefficient were less than 0.6, and the heat shielding glasses had an excellent heat shielding performance.

(Evaluation of redness in reflection color)

For each heat shielding glass, the redness of color contained in the reflection colors Cf and C_g from the heat shielding glass was evaluated using the abovedescribed method.

In the color coordinates of reflection color column (redness in reflection color a*) in TABLE 2, a* values of color coordinates in the CIE 1976 L*:a*:b* color

-28coordinate system of the reflection colors Cf and C_g, which were measured in the respective heat shielding glasses, are shown.

From the results, it was found that in the heat shielding glasses according to Examples 1 to 6, all the a* values were negative (a* < 0), and the reflection colors C_f and C_g included almost no redness.

(Evaluation of yellowness in reflection color)

For each heat shielding glass, the yellowness of color contained in the reflection colors Cf and C_g from the heat shielding glass was evaluated using the abovedescribed method.

In the Yl E313 column in TABLE 2, values of the Yl E313 for the reflection colors C_f and C_g, which were measured in the respective heat shielding glasses, are shown.

From the results, it was found that in the heat shielding glasses according to Examples 1 to 6, values of Yl E313 for C_f and C_g were less than -5 (Yl E313 < -5) , and the reflection colors included almost no yellowness.

. (Evaluation of dull effect in heat shielding glass)

For each heat shielding glass, the dull effect was evaluated using the above-described method.

FIGS. 9 to 12 illustrate examples of a spectrum waveform of reflected light obtained for some of the heat shielding glasses. FIG. 9 illustrates a result obtained in the heat shielding glass according to Example 1. FIG. 10 illustrates a result obtained in the heat shielding glass according to Example 3. FIG. 11 illustrates a result obtained in the heat shielding glass according to Example 8. FIG. 12 illustrates a result obtained in the heat shielding glass according to Example 10.

“ί

-29Note that in each drawing, spectrum waveforms of the reflectance R_f (i.e. result on the heat shielding film side) and the reflectance Rg (i.e. result on the glass plate side) are shown, respectively.

From the above-described results, it was found, for example, that in the case of the heat shielding glass according to Example 1, as illustrated in FIG. 9, for both of the reflectance R_f and the reflectance R_g, in the range of the wavelength of 380 nm to 540 nm, at most one peak existed. As illustrated in FIG. 10, the same applies to the heat shielding glass according to Example 3 also.

In the case of the heat shielding glass according to Example 8, as illustrated in FIG. 11, in the spectrum waveform of the reflectance Rf, two distinct peaks can be observed (peak wavelengths are about 420 nm and 520 nm). Note that for the spectrum waveform of the reflectance R_g, in a small wavelength region of a wavelength of 400 nm to 440 nm, a shoulder part is present; therefore, it is seemingly difficult to determine whether the number of peaks is one or two. According to the above-described decision criterion by the number of locations where a first-order differential value changes from positive to negative, the shoulder part is not regarded as a peak. Thus, the number of peaks in the spectrum waveform of the reflectance R_g is one.

As a result, it is determined that for the heat shielding glass according to Example 8, although the spectrum waveform of the reflectance R_g includes only one peak, because two peaks exist in the spectrum waveform of the reflectance R_f, a dull effect is present (i.e. a clear impression cannot be obtained).

Furthermore, in the case of the heat shielding glass according to Example 10, as illustrated in FIG. 12,

Ί

-30in the spectrum waveform of the reflectance Rf, two distinct peaks are observed (peak wavelengths are about 420 nm and 520 nm). Similarly, in the spectrum waveform of the reflectance R_g, two distinct peaks are observed (peak wavelengths are about 420 nm and 520 nm).

It is determined that for the heat shielding glass according to Example 10, because two peaks exist in both of the spectrum waveform of the reflectance R_g and the spectrum waveform of the reflectance Rf, a dull effect is present (i.e. a clear impression cannot be obtained).

In the number of peaks column in TABLE 2, the number of peaks found in the spectrum waveforms of the reflectance Rg and the reflectance R_f for the respective heat shielding glasses, are shown.

From the results, it was found that in the heat shielding glasses according to Examples 1 to 6, each of the spectrum waveforms of the reflectance R_g and the reflectance Rf includes only one peak. Thus, for the heat shielding glasses according to Examples 1 to 6, it was found that a clear impression can be obtained in either case of viewing from the heat shielding film side or from the glass plate side.

INDUSTRIAL APPLICABILITY

The present invention can be preferably applied to a heat shielding glass or the like.

The present application is based on and claims the benefit of priority of Japanese Priority Application No. 2015-128764 filed on June 26, 2015, the entire contents of which are hereby incorporated by reference.

REFERENCE SIGNS LIST apparatus

-31WWW

5	integrating sphere detector
10	sample
12	glass plate
15	heat shielding film
30	sheet of white paper
100	heat shielding glass
110	glass plate
112	first surface
114	second surface
130	heat shielding film
140	first layer
145	second layer (conductive tin oxide containing layer
150	third layer
530	first heat shielding film
540	undercoat layer
545	conductive tin oxide containing layer
550	high refractive index layer
630	second heat shielding film
640	first undercoat layer
641	second undercoat layer
645	conductive tin oxide containing layer
730	third heat shielding film
740	first undercoat layer
741	second undercoat layer
745	first conductive tin oxide containing layer
746	second conductive tin oxide containing layer
830	fourth heat shielding film
840	first undercoat layer
841	second undercoat layer
845	first conductive tin oxide containing layer

second conductive tin oxide containing layer

846

2016283264 14 Aug 2019

Claims

1. A heat shielding glass comprising:

a glass plate having a first surface and a second surface opposite to each other; and a heat shielding film provided on the first surface of the glass plate, wherein the heat shielding film is configured of three or more layers including a conductive tin oxide containing layer, wherein both yellowness indices Yl E313 of a reflection color Cf from the heat shielding film side and a reflection color C_gfrom the glass plate side are less than -5, wherein values of a color coordinate a* of the reflection color Cf from the heat shielding film side and of the reflection color C_g from the glass plate side expressed by the CIE 1976 L*:a*:b* color coordinate system are negative, wherein at most one location exists where a sign of a first first-order differential value Bl changes from positive to negative, the first first-order differential value Bl being obtained by first-order differentiation of a curve of a first spectroscopic reflection spectrum within a range of a wavelength of 380 nm to 550 nm, the first spectroscopic reflection spectrum being measured in a state where the heat shielding glass is brought into contact with an integrating sphere detector on the heat shielding film side, and brought into contact with a sheet of white paper on the glass plate side, and wherein at most one location exists where a sign of a second first-order differential value B2 changes from positive to negative, the second first-order differential value B2 being obtained by first-order differentiation of a curve of a second spectroscopic reflection spectrum within a range of a wavelength of 380 nm to 550 nm, the second spectroscopic reflection spectrum being measured in a state where the heat shielding glass is brought into contact with the integrating sphere detector on the glass plate side, and brought into contact with

AH26(23212150_l):RTK

2016283264 14 Aug 2019 the sheet of white paper on the heat shielding film side.

2. The heat shielding glass according to claim 1, wherein a shielding coefficient represented as SC that is obtained by formula (1)

SC = g-value / 0.88, (formula (1)) where a solar radiation heat reception rate is represented as a g-value, is less than 0.7.

3. The heat shielding glass according to claim 1 or 2, wherein the conductive tin oxide containing layer includes antimony doped tin oxide or fluorine doped tin oxide.

4. The heat shielding glass according to any one of claims 1 to

3, wherein the heat shielding film includes a titanium oxide layer on the conductive tin oxide containing layer.

5. The heat shielding glass according to any one of claims 1 to

4, wherein the heat shielding film includes an undercoat layer having a silicon oxide layer and/or a tin oxide layer.

6. The heat shielding glass according to claim 5, wherein the undercoat layer is configured of two layers.

7. The heat shielding glass according to any one of claims 1 to 6, wherein the conductive tin oxide containing layer has a two layer structure of an antimony doped tin oxide layer and a fluorine doped tin oxide layer.

8. The heat shielding glass of claim 1 or 2, wherein the heat shielding film includes:

an undercoat layer;

AH26(23212150_l):RTK

2016283264 14 Aug 2019 a conductive tin oxide containing layer; and a high refractive index layer with a refractive index of greater than two;

wherein the undercoat layer includes silica or tin oxide of 50 mass% or more, and has a thickness that falls within a range of 10 nm to 100 nm;

the conductive tin oxide containing layer includes tin oxide in which at least antimony is doped, and has a thickness that falls within a range of 50 nm to 280 nm; and the high refractive index layer includes titanium oxide, and has a thickness that falls within a range of 10 nm to 70 nm.

9. The heat shielding glass according to claim 1 or 2, wherein the heat shielding film includes:

a first undercoat layer;

a second undercoat layer;

a conductive tin oxide containing layer; and a high refractive index layer with a refractive index of greater than two;

wherein the first undercoat layer includes tin oxide, and has a thickness that falls within a range of 10 nm to 50 nm;

the second undercoat layer includes silicon oxide, and has a thickness of 25 nm to 50 nm;

10. The heat shielding glass according to claim 1 or 2, wherein the heat shielding film includes:

a first undercoat layer;

a second undercoat layer;

AH26(23212150_l):RTK

2016283264 14 Aug 2019 a first conductive tin oxide containing layer; and a second conductive tin oxide containing layer;

the second undercoat layer includes silicon oxide, and has a thickness of 25 nm to 50 nm; and the first conductive tin oxide containing layer and the second conductive tin oxide containing layer include tin oxide in which at least antimony is doped, and have a total thickness that falls within a range of 270 nm to 510 nm.

11. The heat shielding glass according to claim 10, wherein a thickness of the first conductive tin oxide containing layer falls within a range of 110 nm to 210 nm, and a thickness of the second conductive tin oxide containing layer falls within a range of 160 nm to 300 nm.

12. The heat shielding glass according to claim 1 or 2, wherein the heat shielding film includes:

an undercoat layer;

a first conductive tin oxide containing layer; and a second conductive tin oxide containing layer;

wherein the undercoat layer includes silica or tin oxide of 50 mass% or more, and has a thickness that falls within a range of 10 nm to 100 nm; and the first conductive tin oxide containing layer and the second conductive tin oxide containing layer include tin oxide in which at least antimony is doped, and has a total thickness that falls within a range of 270 nm to 510 nm.