JP2535350B2 - High transmission solar control glass - Google Patents

Description

TECHNICAL FIELD The present invention relates to a high-transmission solar control glass, particularly a high-transmission solar control glass suitable as a window glass for automobiles and also usable as a single plate.

[Prior Art] Conventionally, by partially cutting off the sunlight that flows into the car through the window glass, reducing the temperature rise inside the car, reducing the cooling load, or reducing the direct light The use of solar control glass has been considered for the purpose of reducing heat and improving comfort. However, in order to ensure visibility from the viewpoint of safety, there is a standard of visible light transmittance of 70% or more in Japan and the United States, and a standard of 75% or more in Europe. As a film that adheres to these standards and that satisfies the required characteristics for solar control glass, the practical upper limit is a three-layer structure of transparent oxide film / Ag film (100 to 200Å) / transparent oxide film. (See Japanese Patent Publication No. 47-6315).
However, the drawback of the system using this Ag film is that the scratch resistance and the chemical durability are extremely poor. Therefore, the solar control glass using this Ag film is
It could only be used in automobiles as laminated glass. However, in recent years, a solar control glass that can be used as a single plate as a side glass and a rear glass for automobiles has been demanded, and development of a solar control film having excellent durability without using an Ag film has been required. . On the other hand, a paper published by a Swedish research group (B. Karlsson, CGRibbing: SPIE
Vol.324 Optical Coatings for Energy Efficiency and
According to Solar Applications (1982) P52-57), TiN,
A thin film of ZrN, HfN is used as a high-refractive-index transparent dielectric (for example, TiO ₂ , Zr
O ₂ , HfO ₂ , Ta ₂ O ₅ , SnO ₂ , ln ₂ O ₃ , ZnO) sandwiched and laminated to obtain a heat ray reflective film that can replace the three-layer heat reaction using a noble metal thin film such as Ag. It has been suggested that there is a possibility that

Therefore, TiN, ZrN, and HfN are TiN, and TiO ₂ and SnO ₂ are high-refractive-index transparent dielectrics. While also it has been most studied because it is excellent in the case of using a sputtering method as a film forming method, TiO ₂
Had a drawback that the film forming speed was slow. Therefore, the heat ray reflective film of three-layered film system using SnO ₂ (SnO ₂ film / TiN film / SnO ₂ film / glass) were considered to be advantageous in view of productivity. However, in this film prepared by sputtering, Sn
The defect that the adhesion between O ₂ and TiN is extremely weak was found experimentally.

[Problems to be Solved by the Invention] An object of the present invention is to solve the above-mentioned drawbacks which the conventional heat ray reflective film having a three-layer structure has.
Improves the adhesion between the SnO ₂ film and the TiN film in the structure of SnO ₂ film / TiN film / SnO ₂ film / glass plate, improves the physical and chemical durability, and further increases the transmittance. Aims to provide solar control glass that can be used as a single plate.

[Means for Solving Problems] The present invention has been made to solve the above problems, and a tin oxide film as a first layer and a second layer as a second layer are formed on a glass plate surface in order from the glass plate side. A highly transparent solar control glass comprising a low light absorption film, a titanium nitride film as a third layer, a low light absorption film as a fourth layer, and a tin oxide film as a fifth layer. Is.

Further, in the above-mentioned high-transmission solar control glass, there is provided a high-transmission solar control glass characterized by being further coated with an overcoat protective film containing silicon oxide or aluminum oxide as a sixth layer. It is a thing.

FIGS. 1 and 2 are partial cross-sectional views of the high transmission solar control glass according to the present invention, wherein 1 and 11 are ordinary flat glass, float glass, blue color made of soda lime silicate glass that is colorless and transparent or colored and transparent, Bronze color,
A glass plate selected from heat-absorbing glass of various colors such as green color, aluminosilicate glass, lithium aluminosilicate glass, borosilicate glass, and various other types of glass, 2 is a tin oxide film as the first layer, and 3 is a second layer Is a low-light-absorbing film, 4 is a titanium nitride film as a third layer, 5 is a low-light-absorbing film as a fourth layer, and 6 is a tin oxide film as a fifth layer. Further, in FIG. 2, 7 indicates an overcoat protective film as the uppermost layer.

In the present invention, the low light absorbing films of the second layer and the fourth layer are selected from those which improve the adhesion between the tin oxide film and the titanium nitride film and do not increase the light absorbing property. Specifically, it is selected from any one of the group consisting of a titanium oxide (TiO ₂ ) film, an aluminum oxide (Al ₂ O ₃ ) film, a zirconium oxide (ZrO ₂ ) film and a chromium oxide (Cr ₂ O ₃ ) film. Be done. Among them, the titanium oxide film is preferable because it has a high effect of improving the adhesiveness. The low light absorbing films of the second layer and the fourth layer may be made of films made of the same material, or may be made of films made of different materials. In the present invention, the film thickness of each layer is not necessarily limited, but the third layer imparting heat ray reflection performance in order to have a visible light average transmittance of 70% or more and to maintain the function as a solar control film. The thickness of the titanium nitride film of
200Å, preferably 100-150Å is used. The second layer,
The thickness of the low-light-absorbing film of the fourth layer is preferably about 20 to 200Å, and the thickness of the tin oxide films of the first and fifth layers is preferably about 200 to 600Å. Also, from the glass plate side, the sum of the thicknesses of the first layer tin oxide film and the second layer low light absorbing film, and the fourth layer tin oxide film and the fifth layer low light absorbing film. The total thickness of both is 300-700Å, preferably 40
0 to 600Å is preferable. Especially when the low light absorption film is a titanium oxide film, a thickness of 20 Å or more is sufficient for the purpose of improving the adhesive force, and at the same time, a TiO ₂ film having a slow sputtering speed for the purpose of increasing the production speed. Therefore, it is desirable to keep it below 200Å.

Further, as an overcoat protective film formed on the fifth layer tin oxide film for the purpose of improving durability so that it can be used as a single plate, SiO ₂ or SiO ₂ as a main component has a refractive index of 1.4.
A film having a refractive index of 1.6 to 1.7 containing Al ₂ O ₃ as a main component is used. The thickness is not particularly limited, but it is also used in the thin region of 0.01 to 1μ for the purpose of controlling the color tone, or in the range of 1 to 3μ as long as it does not affect the interference effect of the lower 5 layer film. It is also possible to use. Especially, as the uppermost protective film,
In the glass plate, for example, the above-mentioned glass plate, the refractive index is 1.4 to 1.6, so that the refractive index is almost the same,
For example, SiO ₂ or a transparent oxide containing SiO ₂ as a main component is desirable.

In particular, SiO ₂ or a protective film containing SiO ₂ as a main component is transparent, has sufficient physical, chemical, and durability, and has a refractive index almost equal to that of a glass plate. Optical characteristics equivalent to those of a glass plate can be obtained. In particular, the thick oxide film of the uppermost layer is, for example, 1 μm to 3 μm, and since the film thickness is considerably larger than the wavelength in the visible light wavelength region,
Even if the thick film is worn or dirt is attached, the heat-reflecting film having practically excellent mechanical strength can be provided with almost no effect on the spectral characteristics.

The method for producing each film in the present invention is not particularly limited, but as a physical thin film forming method, an electron beam heating vapor deposition method, various ion plating methods, an arc vapor deposition method, a sputtering method and the like can be used. In particular, the sputtering method is currently excellent as a method for forming a thin film on a large area substrate. As a chemical thin film forming method, atmospheric pressure CV is used.
It is also possible to use the D method, the low pressure CVD method, the plasma CVD method, the optical CVD method, or the like. A sol-gel method or the like can be used as the SiO ₂ overcoat layer.

The heat ray reflective film in the present invention utilizes the interference between the titanium nitride film and the tin oxide film. Therefore, by selecting the film thickness constitution, visible light transmittance of 70% or more, solar energy transmittance of 60% or less, and visible light reflectance of 10% or less can be obtained. As an example of the structure of the heat ray reflective film that gives this spectral characteristic, the following structure can be given.

(1) Film composition: SnO ₂ film / TiO ₂ film / TiN film / TiO ₂ film / SnO ₂ film / glass plate Film thickness: 400Å / 100Å / 100Å / 100Å / 400Å / 3mm (2) Film composition: SnO ₂ film / Al ₂ O ₃ film / TiN film / Al ₂ O ₃ film / SnO ₂ film /
Glass plate Film thickness: 400Å / 100Å / 100Å / 100Å / 400Å / 4mm Further, as a 6-layer heat ray reflective film constitution, the following constitution can be mentioned.

Film composition: SiO ₂ film / SnO ₂ film / TiO ₂ film / TiN film / TiO ₂ film / SnO ₂ film /
Glass plate film thickness: 2 μm / 400Å / 100Å / 100Å / 100Å / 400Å / 3 mm In the present invention, the heat ray reflective film having a five-layer structure or a six-layer structure as described above is formed on the glass plate. Therefore, in some cases, an alkali component elution preventing film from glass or a plurality of layers of glass, an adhesion improving film and other various functional films may be formed between the glass plate and the heat ray reflective film.

[Operation] It is not clear why the SnO ₂ film and the TiN film have extremely weak adhesion, but in the present invention, the TiO ₂ film and the Al ₂ O ₃ film
The adhesion is improved by inserting the film, the ZrO ₂ film, or the Cr ₂ O ₃ film between the SnO ₂ film and the TiN film. In particular, when interposing a TiO ₂ film, the TiO ₂ and TiN films are the same Ti compound,
It is considered that strong adhesion can be obtained as long as the film is continuously formed in the vacuum chamber. Further, TiO ₂ and SnO ₂ are the same oxide, and it is considered that strong adhesion can be obtained as long as they are continuously formed into a film in a vacuum chamber. Therefore, it is considered that a film having excellent adhesion, that is, excellent durability is formed with the TiO ₂ film interposed.

[Example] Example 1 Metal titanium and metal tin were set as targets in a high frequency magnetron sputtering apparatus. A clean and dried clean soda lime glass plate (plate thickness: 3 mm) was placed in a vacuum chamber and evacuated to 1.0 × 10 ⁻⁵ Torr or less by an oil diffusion pump. First, a mixed gas of Ar: O ₂ = 4: 5 was introduced into the vacuum chamber so that the pressure became 3 × 10 ^-3 Torr, 1.7 W / cm ² power was applied to the Sn target, and SnO was added. ₂ was deposited to 400 Å.
Next, a mixed gas of Ar: O ₂ 4: 6 was introduced, and the pressure was 3 × 10 ^-3.
A power of 5.1 W / cm ² was applied to the Ti target so as to be Torr, and 100 Å of TiO ₂ was deposited. Next, the atmosphere in the vacuum chamber was completely replaced with a mixed gas of Ar: N ₂ = 82.5: 17.5, the pressure was adjusted to 1.2 × 10 ^-3 Torr, and the Ti target was 4.6 W / cm ²
Was applied, and TiN was formed into a 100 Å film. Then, the atmosphere was returned to the mixed gas of Ar: O ₂ = 4: 6 to form 100 Å film of TiO ₂ , and further 400 Å film of SnO ₂ was formed with the mixed gas of Ar: O ₂ = 4: 5. When the spectral characteristics of this five-layer film were measured, its visible light transmittance was 71% and sunlight transmittance was 52%. No film peeling occurred even in the peeling test by the Cellotape test, and the sand eraser test The evaluation of scratch resistance by means of TiO ₂ film (500 Å) / TiN film (100 Å) / TiO ₂ film (500 Å) / glass plate showed better performance than solar control glass.

Example 2 Metal titanium and metal tin were set as targets in a high frequency magnetron sputtering apparatus. A clean soda lime glass substrate that had been washed and dried was placed in a vacuum layer and evacuated to 1.0 × 10 ⁻⁵ Torr or less by an oil diffusion pump. First Ar:
A mixed gas of O ₂ = 4: 5 was introduced into the vacuum chamber and the pressure was 3
A power of 1.7 W / cm ² was applied to the Sn target at a pressure of × 10 ^-3 Torr, and 400 Å of SnO ₂ was deposited. Then Ar: O ₂ = 4:
The mixed gas of 6 was introduced, the pressure was adjusted to 3 × 10 ^-3 Ton, and the power of 5.1 W / cm ² was applied to the Ti target.
O ₂ was deposited to 100 Å. Next, the atmosphere in the vacuum is Ar: N ₂ = 82.
Completely replace the gas mixture with 5: 17.5 and adjust the pressure to 1.2 × 10 ^-3 Tor.
After adjusting to r, a power of 4.6 W / cm ² was applied to the Ti target, and TiN was deposited to 100 Å. Then change the atmosphere again to Ar: O ₂ = 4: 6
Return to the mixed gas of TiO ₂ and form a 100 Å film of TiO _2.
A 400Å SnO ₂ film was formed with a mixed gas of O ₂ = 4: 5. Furthermore, the atmosphere in the vacuum chamber was set to 100% Ar and the sputtering pressure was 2.5 × 10 ^-3.
Was adjusted to Torr, the SiO ₂ was 2μm deposited by sputtering for 75 minutes by applying a power of 3.1 W / cm ² to SiO ₂ target. When the spectral characteristics of the thus obtained 6-layer film were measured, the visible light transmittance was 71% and the sunlight transmittance was 58%.
The peeling test by the cellophane test did not cause the film peeling, and the abrasion resistance evaluation by the sand eraser test also showed that the SiO ₂ film (2 μm) / TiO ₂ film (500 Å) / TiN film (100
Å) / TiO ₂ film (500 Å) / glass plate showed the same performance as solar control glass.

Comparative Example Under the conditions shown in Examples 1 and ₂ , SnO ₂ film (500Å) / Ti
A solar control glass having a structure of N film (100 Å) / SnO ₂ film (500 Å) / glass plate was created. In the peeling test by the cellotape test for this sample, film peeling occurred between the first layer SnO ₂ and the second layer TiN.

EFFECTS OF THE INVENTION According to the present invention, by interposing a low light-absorbing film such as a titanium oxide film between a tin oxide film and a titanium nitride film, it is possible to increase the adhesive force between the two, which is high. It is possible to obtain a solar control glass having heat ray reflection performance, high transparency, and high durability. Therefore, the solar control glass of the present invention can be used as a single plate, and is suitable as a glass plate for side windows of automobiles, rear windows, and the like. Furthermore, by forming an overcoat protective film on the uppermost layer of the heat ray reflective film of the solar control glass of the present invention, the durability can be further improved, and it is even more preferable when used as a single plate.

[Brief description of drawings]

1 and 2 are partial cross-sectional views showing a film structure of a solar control glass according to a specific example of the present invention. 1 ... Glass plate 2,6 ... Tin oxide film 3,5 ... Low light absorption film 4 ... Titanium nitride film 5 ... Protective film

Claims (8)

(57) [Claims] 1. A tin oxide film as a first layer, a low light absorption film as a second layer, a titanium nitride film as a third layer, and a low light absorption film as a fourth layer on a glass plate surface in order from the glass plate side. , Fifth
Highly transparent solar control glass, characterized in that a tin oxide film is laminated as a layer. 2. The low light-absorbing film is any one of the group consisting of a titanium oxide film, an aluminum oxide film, a zirconium oxide film, and a chromium oxide film. Highly transparent solar control glass. 3. The high transmission solar control glass according to claim 1, which has an average visible light transmittance of 70% or more. 4. The high transmission solar control glass according to claim 1, wherein the tin oxide film has a thickness of 200 to 600 liters. 5. The high transmission control glass according to claim 1, wherein the titanium nitride film has a film thickness of 50 to 200Å. 6. The high transmission control glass according to claim 1, wherein the low light absorbing film has a thickness of 20 to 200 liters. 7. A tin oxide film as a first layer has a thickness of 200 to 600Å,
The low light absorbing film as the second layer is 20 to 200Å, the titanium nitride film as the third layer is 50 to 200Å, the low light absorbing film as the fourth layer is 20 to 200Å, and the tin oxide as the fifth layer. Membrane is 200 ~
Highly transparent solar control glass according to claim 1, characterized in that it is 600Å. 8. A fifth layer of tin oxide film is covered with a sixth layer of a silicon oxide film or an overcoat protective film containing an aluminum oxide film as a main component. The highly transparent solar control glass according to item 1.