JPS63242948A - heat reflective glass - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention provides a heat-reflecting glass that can reduce the visible light reflectance on the film lamination side and set the visible light transmittance to an arbitrary value, especially from the film lamination side. The present invention relates to a low-reflectivity, heat-reflecting glass having a visible light reflectance of 20% or less.

[Prior art 1] In recent years, the openings of architectural window glasses have tended to be enlarged for design and comfort. Along with this, the amount of sunlight entering has increased, and the indoor cooling load has increased. In order to reduce this load, heat-reflecting glass is increasingly being used. A single metal is used as heat-reflecting glass.

Various nitride films, carbide films, oxide films, and certain combinations thereof are known, and their visible light reflectance is also high in correspondence with their heat ray reflection performance. For example, when glass is coated with a translucent chromium film to provide heat ray reflection performance, visible light is also reflected, and the same degree of reflection occurs on both sides of the glass substrate. Therefore, with conventional heat-reflecting films, as the heat-reflecting performance improves, the reflection increases on both sides of the glass substrate, and when seen indoors at night, the glass becomes mirror-like and objects inside the room are reflected. Ta.

Furthermore, titanium nitride is highly durable and has high heat ray reflection performance, making it suitable as a heat ray reflective film for heat ray reflective glass. Although it is necessary to increase the film thickness,
The visible light reflectance also increases at the same time, and internal stress also increases, resulting in a decrease in durability.

[Problems to be solved by the invention] Single chromium, known as conventional heat ray reflective glass,
Titanium nitride single-layer films have improved heat ray reflection performance and high visible light reflectance on the indoor side (film side), for example 30%.
As described above, when there is no sunlight at night, objects in the room are reflected by the heat-reflecting glass due to the light from the indoor lamp, resulting in poor livability. Further, although heat ray reflection performance can be achieved by increasing the thickness of the film, it also has the drawback of increasing the internal stress of the film and reducing durability.

[Means for Solving the Problems] The present invention has been made to solve the above-mentioned problems, and has a three-layer film structure for a heat ray reflective film formed on a glass substrate, and a metal film is formed from the substrate side. By sequentially laminating , nitride film, and oxide film, it is possible to reduce the average reflectance of visible light on the film side to 20% or less while maintaining heat ray reflection performance, and to improve durability. This is what I did.

The structure of the heat ray reflective glass of the present invention is as shown in FIG. 1, in which three layers are laminated on a glass substrate 11 from the substrate 11 side: a metal film 12, a nitride film 13, and an oxide film 14. . The feature of the present invention is the three-layer structure described above, but in some cases, a film having one or more layers of various mechanical parts may be formed as an upper layer or a lower layer of this three-layer film. good.

As the glass substrate used in the present invention, substrates made of various types of glass are used, but usually they are ordinary plate glass made of soda lime silicate glass or float plate glass, and may be colorless and transparent or colored and transparent. good.

The metal film as the first layer contains Cr, Ti, Zr, Hf.
.

Made of Ta, old, No, Nb, W, Si or an alloy thereof, or stainless steel (SUS),
The thickness depends on the respective materials and the required visible light transmittance, heat ray reflection performance, etc., but is usually in the range of 20 to 100. Among them, chromium and stainless steel are optimal because they have good adhesion to the glass substrate and the second layer nitride film, and provide a highly durable film. Cost reduction can be achieved by using a stainless steel membrane.

The nitride film as the second layer has the role of maintaining heat ray reflection performance and film hardness, and the film material is Ti,
Nitrides of Zr, Ta, Ni, Or, or composite nitrides of these are used. The film thickness depends on the required heat ray reflection performance and visible light transmittance, but is usually 20
A range of 0 to 550 people is appropriate. Among these, titanium nitride or dirco nitride is most suitable as the nitride film from the viewpoint of ease of film formation, durability, heat resistance performance, etc.

The oxide film as the third layer functions as a protective film that improves the durability of heat ray reflection performance and as a film that reduces the visible light reflectance to 20% or less.The film material is Ti. , Or.

Oxides of Zr, Si, AI, Ni, Ta, Nb, etc. or composite oxides of these are used. The optimum thickness of the film is 100 to 500 to provide sufficient protection and a visible light reflectance reduction effect. Among these, oxide films are easy to form, durable,
Titanium oxide is most suitable from the viewpoint of anti-reflection performance. By changing the thickness of this oxide film, it is possible to change the extent to which the reflectance is reduced, for example, in the range of 10 to 20%. I will give an example of this.

(1) Titanium oxide/titanium nitride/chromium/glass plate thickness 120 people) (510 people) (100 people) (
3m layer) (2) Titanium oxide/Titanium nitride/Stainless steel/
Glass plate thickness 150 people) (550 people) (80 people) (
3a+m) (3) Titanium oxide/titanium nitride/stainless steel/glass plate thickness 450 people) (250 people) (20 people) (3+sm
) In the present invention, a physical vapor deposition method such as a sputtering method, a vacuum evaporation method, or an ion blating method is employed as a method for forming a metal film, a nitride film, and an oxide film.

Among these, reactive sputtering is the most suitable method for forming nitride films due to the film formation rate and stability of film quality.

[Function] The structure of the present invention is characterized in that by giving each layer a different role in this way, visible light reflectance is reduced while maintaining heat ray reflective performance, and durability is further improved. do. In addition, in this case, by changing the thickness and material of the second nitride film and the third oxide film, the spectral characteristics can be changed without changing the visible light reflectance of the film side surface. By giving the product a visually pleasing color, it is possible to increase the added value.

[Example] Examples of the present invention will be described below.

Example 1 A 30 cm square float glass substrate (soda lime silicate glass) with a plate thickness of 3 m was prepared, thoroughly washed and dried, and then placed in the vacuum chamber of an RF magnetron sputtering device, and the vacuum chamber was heated to IX. 1O-5 Torr
After reducing the pressure to 2X 1O, introduce argon gas.
-3 Torr, RF sputtering was performed using Cr as a target in this argon atmosphere at a target voltage of 2 KV to form a first layer of 20 ± 5 mm on the glass plate.
% film H was formed. Then inside this vacuum chamber
After reducing the pressure to 1X10-5 Torr, N2 gas was introduced to make it 2X 1O-3 Torr, and R was applied at a target voltage of 3KV using Ti as a target in this N2 gas atmosphere.
A titanium nitride film having a thickness of 230±5% was formed as a second layer on the chromium film by F sputtering. Then, after reducing the pressure in this vacuum chamber to LX 1O-5 Torr, 02 gas was introduced to make the pressure 2X 1O-3 Torr, and Ti was targeted at 3K in this 02 gas atmosphere.
RF sputtering was performed at a target voltage of V to form a titanium oxide film having a thickness of 500±5% as a third layer on the titanium nitride film. Note that the glass substrate was not heated when forming the chromium film, titanium nitride film, and titanium oxide film. The average visible light transmittance of the thus obtained heat-reflecting glass with the three-layer film formed was 40% and the average visible light reflectance was 8%, and its spectral characteristics (characteristics of reflectance with respect to wavelength) were measured. The results are shown in curve A (visible light reflectance curve) in FIG.

Curve B (visible light transmittance curve l1a) in FIG. 2 is obtained by sequentially applying an 80 mm thick chromium film, a 480 mm thick titanium nitride film, and a 140 mm thick titanium oxide film to the same glass substrate using the same method as above. The spectral characteristics of the heat-reflecting glass formed in the above are measured.

The visible light transmittance can be set to any value from 10% to 40% even if the film thickness of each layer is calculated using a computer simulation based on the actually measured refractive index of the heat ray reflective film as described above. It is recognized that The third layer oxide film has the role of a protective film against incident light from the film surface side as well as the role of reducing visible light reflection, so by changing the thickness of this film, the visible light reflectance can be increased. 1 as needed
It can range from 0% to 20%.

Example 2 A 30cm square float glass substrate (soda lime silicate glass) with a thickness of 3cm was prepared, thoroughly washed and dried, and then placed in the vacuum chamber of an RF magnetron sputtering device, and the vacuum chamber was heated to After reducing the pressure to 1O-5 Torr, argon gas was introduced and 2 x 1O-
3 Torr, RF sputtering was performed using SuS as a target at a target voltage of 2.4 KV in this argon atmosphere to form a stainless steel film with a thickness of 20 ± 5% as a first layer on the glass plate. After reducing the pressure in this vacuum chamber to IX 1O-5Tarr, N
2 gas was introduced to make the pressure 2X 101 Torr, and in this N2 gas atmosphere, Ti was used as a target and RF spar two was performed at a target voltage of 3 KV to form a second layer on the stainless steel film with a thickness of 250 ± 5%. A titanium film was formed. After that, inside this vacuum chamber, l x 1O-
After reducing the pressure to 5 Torr, 02 gas was introduced and 2X
RF was conducted at a target voltage of -3K V with Ti as a target in this 02 gas atmosphere at 1G-3 Torr.
A titanium oxide film having a thickness of 450±5% was formed as a third layer on the titanium nitride film by sputtering. Note that the glass substrate was not heated when forming the stainless steel film, titanium nitride film, and titanium oxide film.

The average visible light transmittance of the heat-reflecting glass with the three-layer film thus obtained is 10%, and the average visible light reflectance is 1.
Curve C (visible light reflectance curve) in FIG. 2 shows the results of measuring the spectral characteristics (characteristics of reflectance with respect to wavelength) at 3%.

Curve D (visible light reflectance curve) in Fig. 2 shows that an 80 mm thick stainless steel film, a 500 mm thick titanium nitride film, and a 150 mm thick titanium oxide film were sequentially applied to the same glass substrate using the same method. The spectral characteristics of the formed heat ray reflective glass were measured.

Comparative Example 1 A 30 cm square float glass substrate (soda lime silicate glass) with a board thickness of 3 cm was prepared, and after thoroughly cleaning and drying it, it was placed in the vacuum chamber of an RF magnetron sputtering device, and the inside of the vacuum chamber was IX 1O-5Tor
After reducing the pressure to r, Ar gas was introduced and 2X 1O-
A chromium film having a thickness of 150 ± 5% was formed on the glass substrate by performing RF sputtering at a target voltage of 2 KV using Gr as a target in the Ar gas atmosphere at 3 Torr. Note that the glass substrate was not heated when forming the chromium film.

The results of measuring the spectral characteristics (characteristics of reflectance with respect to wavelength) of the heat-ray reflective glass on which the single-layer heat-ray reflective film obtained in this way was formed are shown in curve E (visible light reflectance curve) in Figure 3. .

Note that the curve F (visible light reflectance direction m) in FIG. 3 is obtained by measuring the spectral characteristics of a heat-reflecting glass in which an 80% chromium film is formed on the same glass substrate by the above method.

Comparative Example 2 A 30 cm square float glass substrate (soda lime silicate glass) with a plate thickness of 3 mm was prepared, thoroughly washed and dried, and then placed in a vacuum chamber of an RF magnetron sputtering device, and the vacuum chamber was heated to IX 1O. -5 Torr
After reducing the pressure to
Torr, and in this N2 gas atmosphere, RF sputtering was performed using Ti as a target at a target voltage of 3 KV to form a titanium nitride film with a thickness of 750 ± 5% on the glass substrate. In addition, when forming the titanium nitride film,
The glass substrate was not heated.

Curve G (visible light reflectance curve) in FIG. 3 shows the results of measuring the spectral characteristics (characteristics of reflectance versus wavelength) of the thus obtained single-layer heat ray reflective glass.

Curve H (visible light reflectance curve) in FIG. 3 is obtained by measuring the spectral characteristics of a heat-reflecting glass in which a 180-layer-thick titanium nitride film is formed on the same glass substrate using the same method.

As can be seen from the above-mentioned Examples and Comparative Examples, in conventional heat-reflecting glass having similar visible light transmittance, when a translucent metal film made of chromium is used as shown in Comparative Example 1, for example, As shown in curves E and F, it can be seen that the heat ray reflection characteristics are somewhat low and the visible light reflectance is high. In this case, the visible light reflection is high during the day, but at night the reflection due to mirroring becomes extremely high and becomes a nuisance. Also,
As shown in curves G and H in Fig. 3 for Comparative Example 2, even in the case of the titanium nitride single layer film, it gradually decreases from the near-infrared region to the visible light region, but it is still high, and the nighttime Mirroring occurs, causing discomfort indoors. In contrast, the heat ray reflective glass of the present invention
As is clear from the spectral characteristics shown in the figure, 350 to 750n
The indoor reflectance in the visible range of m is small, and mirror 7 formation at night is sufficiently suppressed. Furthermore, with this configuration, it is possible to arbitrarily change the visible light transmittance by mainly adjusting the metal film thickness.

[Effects of the Invention] According to the present invention, the visible light reflectance on the indoor side is suppressed to a range of 10 to 20% by the structure in which a metal film, a nitride film, and an oxide film are sequentially laminated on a float glass substrate. This can reduce the need for mirrors on window glass at night and improve livability. Further, according to the present invention, by mainly changing the thickness of the metal film, it is possible to obtain any visible light transmittance depending on the application and purpose without impairing the heat ray reflection performance. Furthermore, the structure in which an oxide film is laminated on the outermost surface makes it possible to improve durability.

11 glass substrate, 12: metal film, 13: nitride film, 1
4 dioxide film

[Brief explanation of drawings]

FIG. 1 is a sectional view of the heat ray reflective glass of the present invention. FIG. 2 is a drawing showing the spectral characteristics of the heat ray reflective glass of Example 1.2 of the present invention. FIG. 3 is a drawing showing the spectral characteristics of the heat ray reflective glass of Comparative Example 1.2. Figure 3 - Table X fL starvation

Claims (6)

[Claims] (1) A heat ray reflective glass having a visible light reflectance of 20% or less on the film side surface, which is formed by laminating a metal film, a nitride film, and an oxide film in order from the substrate side on the surface of a glass substrate. (2) The material of the metal film is Cr, Ti, Zr, Hf, Ta,
The heat ray reflective glass according to claim 1, characterized in that the glass is selected from the group consisting of Ni, Mo, Nb, W, Si, alloys thereof, and stainless steel. (3) The material of the nitride film is Ti, Zr, Ta, Ni, Cr
The heat ray reflective glass according to claim 1, characterized in that the glass is selected from the group consisting of nitrides and composite nitrides thereof. (4) The material of the oxide film is Ti, Cr, Zr, Si, Al
, Hf, Ta, Nb oxides, and composite oxides thereof. (5) The heat ray reflective glass according to claim 1, wherein a chromium film, a titanium nitride film, and a titanium oxide film are sequentially laminated on the surface of a glass substrate. (6) The heat ray reflective glass according to claim 1, wherein a stainless steel film, a titanium nitride film, and a titanium oxide film are sequentially laminated on the surface of a glass substrate.