JP3053669B2 - Heat shielding film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-shielding film having excellent durability, especially acid resistance.

[0002]

2. Description of the Related Art An oxide film, an Ag film, a three-layer film in which an oxide film is sequentially laminated on a substrate surface, or an oxide film, Ag
A film composed of (2n + 1) layers (n ≧ 1), such as a film composed of five layers in which a film, an oxide film, an Ag film, and an oxide film are sequentially laminated,
This is a heat ray blocking film called a Low-E (Low-Emissivity) film, and the glass on which the Low-E film is formed is called a Low-E glass.

[0003] This is a functional glass capable of preventing a temperature drop in a room by reflecting heat rays from the room, and is mainly used in cold regions for the purpose of reducing a heating load. It also has the effect of blocking solar heat, so that it is also used in automotive window glass. Since it is transparent and shows conductivity, it is also used as an electromagnetic shielding glass. If an electric heating means such as a bus bar made of a conductive print or the like is provided, it can be used as an electrically heated glass.

[0004] The main Low-E glass is ZnO.
/ Ag / ZnO / those having a membrane structure that a glass can be mentioned <br/> up. However, ZnO has insufficient acid resistance, and there is a concern that it will be degraded by acidic substances in the air.
Further, such a Low-E film lacks durability such as abrasion resistance and chemical stability, so that it cannot be used as a single plate and needs to be laminated glass or double glazing. In particular, there is a problem in moisture resistance, and white spots and white turbidity are generated due to humidity in the air and moisture contained in the interlayer film when the laminated glass is used. For this reason, care has to be taken in storage and handling of veneers.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned drawbacks of the prior art and to provide a heat-ray shielding film having excellent durability, especially moisture resistance and acid resistance. It is.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has a structure in which an oxide film, a metal film, and an oxide film are alternately stacked on a substrate. In the heat ray blocking film composed of (n ≧ 1), the oxide film (B) formed on the opposite side of the metal film (A) farthest from the substrate when viewed from the substrate is a film mainly composed of zinc oxide. and at least one layer, that provides low emissivity film which is a multilayer film having at least one layer of film composed mainly of tin oxide.

FIG. 1 is a sectional view of a typical example of the heat ray blocking film of the present invention. FIG. 1A is a cross-sectional view of a heat ray blocking film having three layers, and FIG. 1B is a cross-sectional view of a heat ray blocking film having (2n + 1) layers. 1 is a substrate, 2 is an oxide film, 3 is a metal film, and 4 is an oxide film (B) which is a multilayer film having a film mainly composed of zinc oxide and a film mainly composed of tin oxide.
As the substrate 1 in the present invention, besides a glass plate, a film or plate of plastic or the like can be used.

The oxide film (B) according to the present invention will be described. When a multilayer film having at least one layer mainly composed of zinc oxide and at least one layer mainly composed of tin oxide is used as the oxide film (B), a heat ray blocking film excellent in acid resistance can be obtained. realizable. Tin oxide has excellent acid resistance and optical properties such as refractive index are almost the same as zinc oxide.Thus, by replacing a part of the conventional zinc oxide film with tin oxide, the optical performance is maintained. Thus, an oxide film (B) having better acid resistance than before can be formed. Meanwhile, when formed by a sputtering method, particularly a DC sputtering method, a zinc film oxidation, since the film can be formed at a higher speed than tin oxide, while considering the above-described acid resistance and the deposition rate, an oxide film (B) It not good is determined the film structure and the film thickness.

[0009] oxide film (B) is a film mainly composed of zinc oxide, but it may also have a film other than film composed mainly of tin oxide. For example, in the case where the heat ray blocking film of the present invention is laminated inside and another substrate is laminated via a plastic intermediate film to form a laminated glass, the adhesive force with the plastic intermediate film is adjusted or the durability is improved. For the purpose of (1), as a layer in contact with the intermediate film (layer farthest from the substrate) , 100
Even if the following oxide film (for example, chromium oxide film) is formed
Not good.

The thickness of the oxide film (B) is not particularly limited, but is preferably 200 to 700 ° in consideration of the color tone and the visible light transmittance of the entire heat ray blocking film. The film thickness of the lamination number and one layer is not particularly limited Ku yo be selected depending on the device. In addition, the film thickness of each layer but it may also be different from each other.

Zinc oxide is divided into thin films, and zinc oxide 1
The thinner the layer, the easier it is to resist the influence of acid from the periphery of the film. Therefore, as a specific film configuration, Z
nO / SnO ₂ / ZnO, SnO ₂ / ZnO / SnO
₂ or a three-layer system such as ZnO / SnO ₂ / ZnO / Sn
O ₂ / ZnO, SnO ₂ / ZnO / SnO ₂ / ZnO
/ SnO ₂ , a similarly stacked seven-layer system, a nine-layer system, etc., so that the thickness of one zinc oxide layer is 200 ° or less, preferably 180 ° or less. <br/> physician. It is particularly preferable that the temperature is set to 100 ° or less and the above-mentioned five-layer system is used. In consideration of productivity at the time of film formation, the film thickness is adjusted to be proportional to the film formation rate of each layer, and a total of 450
The above-mentioned five-layer laminated film is preferable.

When the oxide film (B) is formed by reactive sputtering in an oxygen-containing atmosphere, the metal film (A)
In order to prevent oxidation of the metal film, it is desirable to first form a thin metal film or a metal oxide film with insufficient oxidation on the metal film (A) in an atmosphere containing less oxygen. This thin metal film is oxidized during the formation of the oxide film (B) to become an oxide film. did
There I preferred thickness of the oxide film of the above (B) is such a thin metal film is a film the film thickness including the thickness of the oxide film Deki oxidized. In this specification, the same applies to an oxide film formed on the metal film 3.

Depending on the film forming conditions, the tin oxide film is relatively
It is easy to form a film having low internal stress, particularly low internal stress of 7.0 × 10 ⁹ dyn / cm ² or less. Although the zinc oxide film also depends on the film forming conditions, a film having a relatively high internal stress is easily formed. Then, as in the present invention , the oxide film (B)
Is composed of a combination of these, a film having low internal stress can be easily obtained as the oxide film (B) as a whole.

If the internal stress of the oxide film (B) is high, the oxide film (B) is included in the interlayer in the case of a humidity in air or a laminated glass due to breakage of the film due to relaxation of the film strain of the oxide film or peeling of the film. Deterioration of the metal film (A), specifically, white turbidity and spots are likely to occur due to the water content. However, if the internal stress is low, such deterioration can be prevented, and the moisture resistance of the film is greatly improved. . Specifically, the internal stress of the entire multi-layer oxide film (B) is 1.1 × 10 ¹⁰ dyn / cm.
^{A value of 2} or less is preferable because it has a great effect on improving the moisture resistance.

In particular, if the internal stress of zinc oxide is low, the film is difficult to peel off due to the influence of acid from the periphery of the film. Therefore, from the viewpoint of acid resistance and the above-mentioned moisture resistance, the internal stress of zinc oxide is low. Preferably it is low. The film containing zinc oxide as a main component is hexagonal, and the internal stress of such a film and Cu
The hexagonal zinc oxide (0
02) The diffraction angle 2θ (the position of the center of gravity) of the diffraction line substantially corresponds to the diffraction angle 2θ (the position of the center of gravity) is 33.88 °.
Value between at 35.00 ° between, in particular, if the value of up to 34.88 ° from 34.00 °, further preferred. Diffraction angle 2θ is 34.44 ° or less values compressive stress, 34.44
° or more values indicate tensile stress, the.

The internal stress of a film greatly varies depending on the film forming conditions. When a film having a low internal stress is formed, it is necessary to precisely control the film forming conditions. Methods that tend to reduce the internal stress of the film include methods such as increasing the pressure (sputter pressure) of the film formation atmosphere during film formation (particularly in the case of using a sputtering method) and performing substrate heating during film formation. A method of changing film conditions, a method of performing heat treatment after film formation, and the like are given. Each specific condition may be selected according to the film forming apparatus, and is not particularly limited.

If another element having an ionic radius smaller than that of Zn ²⁺ is added to the zinc oxide film in an oxidized state, the internal stress of the film tends to be reduced although there is considerable variation depending on the film forming conditions . For even acid Kasuzumaku, there is a similar trend.

In the case where another element having an ion radius smaller than that of Zn ²⁺ is added (doped) to the ZnO film in an oxidized state, the added elements are Al, Si, B, Ti, Sn, Mg,
Cr and the like. Film also, Z which was although mainly composed of ZnO doped with at least one from among these I
It can be used similarly to the nO film. The doping amount is Al, Si,
B, Ti, Sn, Mg, at least one of Cr,
Even if the atomic ratio is set to 10% or more with respect to the total amount of Zn, the internal stress reduction effect often remains unchanged.
About 0% or less is sufficient. Such a ZnO film doped with another element is also made of (00) of hexagonal zinc oxide.
2) Regarding the diffraction angle 2θ (center of gravity position) of the diffraction line, ZnO
The same can be said for the membrane.

The material of the oxide film 2 other than the oxide film (B) is not particularly limited. ZnO, SnO ₂ , TiO ₂ ,
These laminated films comprising two or more, these were added to the other elements films and the like can be used, further, in consideration of the productivity, ZnO film, two-layer SnO ₂ film, ZnO and the SnO ₂ alternately Films laminated above, Al, Si, B, Ti, S
A ZnO film in which at least one of n, Mg, and Cr is added in a total amount of 10 atomic% or less based on the total amount with Zn is preferable.

In consideration of color tone and visible light transmittance, it is desirable that the oxide film 2 has a thickness of 200 to 700 °. In the case of a laminated film, the total thickness may be 200 to 700 °, and the thickness of each layer is not limited.

In particular, in the case of a heat ray blocking film having a five-layer structure of an oxide film, a metal film, an oxide film, a metal film, and an oxide film, or a film structure of five or more layers, the outermost oxide film (B The oxide film 2 other than the above) also has an internal stress of 1.1 × 10 ¹⁰ dyn / cm.
It is desirable to use ^two or less films.

In the present invention, the metal film 3 is made of Ag.
A film having a heat ray blocking performance such as a film or a film mainly containing Ag containing at least one of Au, Cu, and Pd can be used. The metal film 3 may have a metal layer having various functions in addition to the metal film having the heat ray blocking performance. For example, it has a metal layer that adjusts the adhesive force between the metal film having the heat ray blocking performance and the oxide film (B) or the oxide film 2, or has a function of preventing metal diffusion from the metal film having the heat ray blocking performance. Examples include a metal layer. Examples of the metal constituting the metal layer having these functions include Zn,
Examples include Al, Cr, W, Ni, Ti, and alloys of two or more of these metals.

The thickness of the entire metal film 3 including these metal layers is suitably 50 to 150 °, particularly about 100 °, in consideration of the balance between heat ray blocking performance and visible light transmittance.

[0024]

The acid resistance is greatly improved by introducing a film containing tin oxide as a main component into the oxide film (B). By introducing a film containing tin oxide as a main component, which easily forms a film having a relatively low internal stress, a film having a low internal stress of 1.1 × 10 ¹⁰ dyn / cm ² or less as a whole oxide film (B). , And the moisture resistance is remarkably improved as compared with the conventional heat ray shielding film. It is considered that this is because the oxide film is less likely to be damaged due to the lower internal stress of the oxide film, and deterioration due to moisture is suppressed.

[0025]

EXAMPLES (Example 1) Using metal targets of Zn, Sn, and Ag, respectively,
The Ag film is formed by a DC sputtering method in an Ar atmosphere.
The SnO ₂ film and the ZnO film were formed by a reactive DC sputtering method in an oxygen-containing atmosphere by ZnO / SnO ₂ / ZnO /
SnO ₂ / ZnO / Ag / ZnO / SnO ₂ / ZnO /
A heat ray shielding film having a film configuration of SnO ₂ / ZnO / glass was produced. Ag was 100 °, and ZnO and SnO ₂ were all 90 ° in one layer. The visible light transmittance of the glass with the heat ray blocking film was 86%, and the emissivity was 0.06.

An acid resistance test was performed by dipping the glass with the heat ray blocking film in 1N hydrochloric acid. No change was observed until 2 minutes after the immersion, but after 3 minutes, the edge of the film began to turn partially brownish, and after 5 minutes, a part of the film was peeled off.

(Comparative Example 1) Using a metal target of Zn and Ag, respectively, an Ag film was formed by Zn sputtering using a DC sputtering method in an Ar atmosphere.
As the film, a heat ray shielding film having a film configuration of ZnO / Ag / ZnO / glass was produced by a reactive DC sputtering method in an oxygen-containing atmosphere. Ag is 100 °, ZnO is 450
Was Å. The visible light transmittance of the glass with the heat ray blocking film was 86%, and the emissivity was 0.06.

An acid resistance test was conducted by immersing the glass with the heat ray blocking film in 1N hydrochloric acid. Immediately after immersion, the film began to peel off, and after 5 minutes, the heat ray shielding film was completely peeled off from the glass and disappeared.

Example 2 ZnO / Sn was formed by RF (high frequency) sputtering.
A Low-E film having a film configuration of O ₂ / ZnO / SnO ₂ / ZnO / Ag / ZnO / glass was produced. Ag is 10
0 °, ZnO between Ag and glass was 450 °, and ZnO and SnO ₂ films on Ag were all 90 ° in one layer. For ZnO and Ag, ZnO and Ag targets are Ar
Gas was sputtered, and SnO ₂ was obtained by sputtering a SnO ₂ target with a mixed gas of Ar and O ₂ . The sputtering pressure, the substrate temperature, and the sputtering power at the time of ZnO and Ag film formation are the same as those in the above embodiment. At the time of SnO ₂ film formation, the sputtering power density is 1 W / cm ² , and Ar: O ₂
The gas flow ratio was 8: 2.

The ZnO / S fabricated under the same conditions as above
The internal stress of the nO ₂ / ZnO / SnO ₂ / ZnO film is 9.
It was 2 × 10 ⁹ dyn / cm ² .

[0031] For such a heat ray shielding film was performed 50 ° C., a moisture resistance test that for 6 days in an atmosphere of 95% relative humidity. The appearance after the moisture resistance test was good, although very fine spots were observed, but no noticeable white spots and white turbidity were observed. In the SEM photograph of the film surface after the moisture resistance test, cracks, wrinkles and peeling were hardly observed on the film surface.

The glass on which the above-mentioned heat ray blocking film was formed was laminated with another glass plate via a plastic intermediate film, with the film inside, to obtain a laminated glass. The same moisture resistance test was performed on the laminated glass. Moisture resistance test 14
Even on the day, no cloudiness or spots occurred.

Example 3 In the same manner as in Example 2 above, ZnO / SnO ₂ /
ZnO / SnO ₂ / ZnO / Ag / ZnO / SnO ₂ /
A heat ray blocking film having a film configuration of ZnO / SnO ₂ / ZnO / glass was produced. Ag is 100 °, ZnO and Sn
Each of the O ₂ films was 90 ° in one layer. The target, sputtering gas, sputtering pressure, substrate temperature, and power density were the same as in Example 2.

The ZnO / SnO ₂ /
The internal stress of the ZnO / SnO ₂ / ZnO film is 9.2 × 10
^{It was 9} dyn / cm ² . The moisture resistance of the obtained heat ray blocking film was as good as in Example 2 above.

(Comparative Example 2) In the same manner as in the above embodiment, ZnO was formed on a glass substrate.
The film, the Ag film, and the ZnO film are each 450 °, 100 °,
The layers were sequentially laminated at a film thickness of 450 °. The target is Z
nO, using Ag, sputtering was Tsu row <br/> by Ar gas. The sputtering pressure, substrate temperature, and sputtering power density are the same as in the second embodiment.

When the obtained heat ray shielding film was examined by an X-ray diffraction method, the diffraction angle 2θ (center of gravity) of the ZnO (002) diffraction line was 33.78 °. Zn produced under these conditions
The internal stress of the O film was 1.5 × 10 ¹⁰ dyn / cm ² .

After the moisture resistance test, the heat-ray shielding film was slightly cloudy on the entire surface, and considerable white spots having a diameter of 1 mm or more were considerably observed. According to the SEM photograph after the moisture resistance test,
The cracks spread over the entire surface of the film, indicating that the film was significantly damaged.

The glass on which the above-mentioned heat ray shielding film was formed was laminated with another glass plate through a plastic intermediate film with the film inside, to obtain a laminated glass. The same moisture resistance test was performed on the laminated glass. Moisture resistance test 14
On the day, cloudiness and spots were clearly observed.

[0039]

The heat ray shielding film according to the present invention has greatly improved acid resistance and moisture resistance. For this reason, it is considered that handling with a single plate becomes easy. In addition, the indoor long-term storage of a single plate is capable of ing. Furthermore, it leads to improvement in reliability of heat ray shielding glass for automobiles and buildings. In addition, even when the laminated glass is used, it is not deteriorated by the moisture contained in the interlayer film, so that the durability of the laminated glass for automobiles and buildings is improved.

Since the heat ray blocking film of the present invention has a metal film, it has conductivity as well as heat ray blocking performance. The Te but Tsu <br/>, low emissivity film of the present invention utilizes the conductive property can be used in various technical fields. For example, in the field of electronics, it can be used as an electrode (which can also be used as an electrode of a solar cell), as a heating element in an electrically heated window, as an electromagnetic wave shielding film in windows and electronic components,
Can be used. In some cases, the heat ray shielding film of the present invention comprises:
It can also be formed on a substrate through films having various functions. In such a case, such as by selecting the optimum thickness of each layer of the heat ray shielding film of the present invention, depending on the application, cut with the optical performance regulatory.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an example of a heat ray shielding glass in which a heat ray shielding film according to the present invention is formed on glass.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Oxide film 3 Metal film 4 Oxide film (B)

Claims (5)

(57) [Claims] 1. A heat ray blocking film composed of (2n + 1) layers (n ≧ 1) alternately laminated with an oxide film, a metal film, and an oxide film on a substrate, when viewed from the substrate, is farthest from the substrate. The oxide film (B) formed on the opposite side of the metal film (A)
A heat ray blocking film characterized by being a multilayer film having at least one film mainly composed of zinc oxide and at least one film mainly composed of tin oxide. 2. The method according to claim 1, wherein the oxide film (B) has a multilayer film composed of three or more layers in which a film mainly composed of zinc oxide and a film mainly composed of tin oxide are alternately laminated. The heat ray shielding film according to claim 1, wherein: 3. The oxide film (B) has three layers alternately laminated with a film mainly composed of zinc oxide, a film mainly composed of tin oxide, and a film mainly composed of zinc oxide. The heat ray shielding film according to claim 2, comprising a multilayer film composed of five, seven, or nine layers. 4. The oxide film (B) has three layers alternately stacked with a film mainly composed of tin oxide, a film mainly composed of zinc oxide, and a film mainly composed of tin oxide. 5 layers, 7 layers, or characterized by having a multi-layer film composed of <br/> 9 layers claim 2
The heat ray shielding film according to the above. Wherein said metal film (A) is according to claim 1, characterized in that a metal film mainly composed of Ag, 2,3 or 4
The heat ray shielding film according to the above.