WO2012121035A1

WO2012121035A1 - Heat reflecting glass plate

Info

Publication number: WO2012121035A1
Application number: PCT/JP2012/054695
Authority: WO
Inventors: 伊村　正明; 金井　敏正
Original assignee: 日本電気硝子株式会社
Priority date: 2011-03-07
Filing date: 2012-02-27
Publication date: 2012-09-13
Also published as: JP2012184140A

Abstract

Provided is a heat reflecting glass plate having high thermal durability. A heat reflecting glass plate (1) comprises a glass substrate (10), metal films (11), and a transparent conductive film (13). The glass substrate (10) has a first main surface (10a) and a second main surface (10b). The metal films (11) are formed on the first main surface (10a). The metal films (11) are disposed spaced apart from each other. The transparent conductive film (13) is formed on either the first main surface (10a) or the second main surface (10b) so as to overlap with the metal films (11) in a planar view.

Description

Heat ray reflective glass plate

The present invention relates to a heat ray reflective glass plate.

Conventionally, transparent heat ray reflective glass plates that transmit light while reflecting heat rays are used for ovens, stoves, fireplaces, window glasses, and the like. As an example of such a heat ray reflective glass plate, for example, Patent Document 1 below discloses a heat ray reflective glass plate in which a heat ray reflective pattern made of a metal such as Ag is formed on a transparent glass plate. . Since the heat ray reflective pattern which consists of a metal with a high heat ray reflectivity is formed in the heat ray reflective glass plate of patent document 1, a high heat ray reflectivity is obtained. And since the light is permeate | transmitted in the part in which the heat ray reflective pattern is not formed, the other side of a heat ray reflective glass plate is visually recognizable.

JP-A-58-140344

However, the heat ray reflective glass plate described in Patent Document 1 has a problem of low thermal durability.

The present invention has been made in view of such a point, and an object thereof is to provide a heat ray reflective glass plate having high thermal durability.

The heat ray reflective glass plate according to the present invention includes a glass substrate, a plurality of metal films, and a transparent conductive film. The glass substrate has first and second main surfaces. The metal film is formed on the first main surface. The metal films are arranged at a distance from each other. The transparent conductive film is formed on at least one of the first and second main surfaces so as to overlap with the metal film spaced from each other in plan view.

Arranged at intervals from each other is an arrangement including the following first and second modes. First, as a first aspect, in a plan view, the metal film has a straight line, a curve, or a combination of both to form a stripe pattern or a lattice pattern intersecting each other, and the surfaces on which the metal film is not formed are spaced apart. This is the case when it is recognized. Further, as a second aspect, a state is shown in which a plurality of discontinuous metal films are formed in a regular or irregular shape on the main surface in plan view.

However, in the case of the first mode, if attention is not paid to the distance between the metal films when they are arranged at a distance from each other, visual interference fringes (also referred to as moire) are generated and sufficient visibility is obtained. In some cases, the second aspect is preferable from this point of view.

The main surfaces are two surfaces facing each other in the thickness direction of the glass substrate. The two main surfaces do not necessarily have to be parallel. That is, the structure which provided the desired unevenness | corrugation as needed may be sufficient.

In the plan view, it means a view from a direction parallel to the thickness direction of the glass substrate.

“To overlap with metal films spaced apart from each other in plan view” means that there is a portion overlapping with the metal film in plan view.

For example, the following method may be employed to arrange the metal film on the main surface in the first or second mode as described above. There are a method of performing masking of a predetermined shape in advance and removing the masking after the film formation, a method of removing unnecessary portions by etching using a photolithography technique after the film formation, or a method of forming a film by screen printing.

In the heat ray reflective glass plate according to the present invention, the heat ray reflection function is realized by the metal film and the transparent conductive film. For this reason, for example, if the metal film is oxidized or denatured by heat, the heat ray reflection function is deteriorated. However, in the heat ray reflective glass plate according to the present invention, a transparent conductive film is provided. For this reason, the intensity | strength of the heat ray transmitted to a metal film can be reduced by arrange | positioning and using the heat ray reflective glass plate which concerns on this invention so that a transparent conductive film may face the high temperature side. Therefore, the transformation of the metal film can be suppressed. Therefore, in the heat ray reflective glass plate according to the present invention, the heat ray reflection function is not easily lowered due to heat deterioration. That is, the heat ray reflective glass plate according to the present invention has high thermal durability.

In the present invention, the “glass substrate” includes a crystallized glass substrate.

The transparent conductive film may be formed on the second main surface. In that case, protective films made of Si oxide, Ti oxide, Zr oxide, Sn oxide, Al oxide or Si nitride are spaced apart from each other on the first main surface. It is preferable that the metal film is formed so as to cover the metal film disposed in the wall. By forming this protective film, it is possible to shut off the metal film and the outside air that are spaced apart from each other. Therefore, the transformation of the metal film can be more effectively suppressed. Therefore, the thermal durability of the heat ray reflective glass plate can be further enhanced.

The transparent conductive film may be formed so as to cover the metal film disposed on the first main surface with a space therebetween. In this case, the transparent conductive film also has a function as a protective film that shields the metal film and the outside air that are spaced from each other. Therefore, even in this configuration, it is possible to more effectively suppress the transformation of the metal films arranged at intervals.

The metal film is preferably made of a material having a high heat ray reflectivity. Specifically, the metal film is preferably made of a metal selected from the group consisting of Al, Cu and Ag, or an alloy containing one or more metals selected from the group consisting of Al, Cu and Ag. By forming the metal film with these materials, the heat ray reflectivity of the heat ray reflective glass plate can be further improved.

The transparent conductive film is also preferably made of a material having a high heat ray reflectivity. Specifically, the transparent conductive film preferably contains indium, tin, or zinc, and more preferably a transparent conductive film containing indium, tin, or zinc as a main component. The main component means that the metal component has a mass content of 60% or more. By forming the transparent conductive film with these materials, the heat ray reflectivity of the heat ray reflective glass plate can be further improved.

In addition, the area occupancy ratio of the metal film in the region where the surface areas of the metal films arranged at intervals from each other are large or the metal films arranged at intervals from each other on the first main surface are provided If it is too high, the visibility through the heat ray reflective glass plate may be lowered.

For this reason, for example, when the metal films arranged at intervals from each other are in the second mode, the metal film is preferably circular or polygonal with a circle-equivalent diameter of 1 mm or less. The area occupation ratio of the metal film in the region where the plurality of metal films on the first main surface is provided is preferably 75% or less. However, if the area occupation ratio of the metal film in the region where the plurality of metal films on the first main surface is provided is too low, the heat ray reflectivity of the heat ray reflective glass plate may be too low. For this reason, it is preferable that the area occupation rate of the metal film in the area | region in which the metal film of the 1st main surface was provided is 20% or more.

According to the present invention, a heat ray reflective glass plate having high thermal durability and visibility can be provided.

FIG. 1 is a schematic plan view of a part of the heat ray reflective glass plate according to the first embodiment. FIG. 2 is a schematic cross-sectional view taken along line II-II in FIG. FIG. 3 is a schematic cross-sectional view of a part of the heat ray reflective glass plate according to the second embodiment. FIG. 4 is a schematic cross-sectional view of a part of the heat ray reflective glass plate according to the third embodiment.

Hereinafter, an example of a preferable embodiment in which the present invention is implemented will be described. However, the following embodiment is merely an example. The present invention is not limited to the following embodiments.

(First embodiment)
FIG. 1 is a schematic plan view of a part of a heat ray reflective glass plate according to the present embodiment. FIG. 2 is a schematic cross-sectional view taken along line II-II in FIG. The heat ray reflective glass plate 1 shown in FIGS. 1 and 2 can be used as a heating device such as a stove or oven, a heating window plate, or a window glass.

As shown in FIG. 2, the heat ray reflective glass plate 1 includes a glass substrate 10. The glass substrate 10 can be formed of, for example, borate glass or heat resistant crystallized glass.

The glass substrate 10 transmits light in the visible wavelength range (400 nm to 700 nm). Here, “transmitting light in the visible wavelength region” means transmitting light in the visible wavelength region to the extent that the other side is visible, and specifically, the average light transmittance in the visible wavelength region is , 25% or more. The glass substrate 10 may be colorless and transparent, or may be colored and transparent.

The thickness of the glass substrate 10 is not particularly limited as long as it is a thickness that can sufficiently ensure the mechanical strength of the heat ray reflective glass plate 1. The thickness of the glass substrate 10 can be about 0.5 mm to 10 mm, for example.

The glass substrate 10 has first and second

main surfaces

10a and 10b. The heat ray reflective glass plate 1 of the present embodiment is used by being arranged such that the second main surface 10b side faces the heat source side, that is, the high temperature side.

A plurality of metal films 11 are formed on the first main surface 10a. The plurality of metal films 11 are arranged at intervals. The arrangement of the metal film 11 may be regular or irregular. By using an irregular arrangement, not only the heat source side such as a heating device can be visually observed, but also the glass substrate can be easily provided with various shaded and decorative patterns. Specifically, various abstract designs or concrete painting-like designs such as landscapes, animals and plants, buildings, or human figures can be applied. However, considering the labor required for production, economic efficiency, etc., a regular arrangement is preferable. Moreover, as a regular arrangement | sequence, it is preferable that it shall arrange in a matrix form, for example. In the present invention, the matrix shape is sufficient if a plurality of metal films are regularly arranged, rows and columns may be arranged in a straight line, or may be arranged in a staggered manner. . In the present embodiment, each of the plurality of metal films 11 is circular or polygonal. The circle equivalent diameter of each metal film 11 is 1 mm or less. Incidentally, the equivalent circle diameter is the diameter of a circle having the same area. Further, the area occupation ratio of the metal film in the region where the plurality of metal films 11 is provided on the first main surface 10a is 75% or less. For example, the thickness of the metal film 11 is preferably 50 nm or more, and more preferably 200 nm or more. The thickness of the metal film 11 is preferably 20 μm or less, for example.

The plurality of metal films 11 are main members responsible for the heat ray reflectivity of the heat ray reflective glass plate 1. For this reason, the metal film 11 is preferably made of a material having a high heat ray reflectivity. Specifically, the metal film 11 is preferably made of a metal selected from the group consisting of Al, Cu and Ag, or an alloy containing one or more metals selected from the group consisting of Al, Cu and Ag.

The thickness of the metal film 11 is not particularly limited, but can be, for example, about 200 nm to 20 μm (= 2 × 104 nm).

A protective film 12 is formed on the first main surface 10 a so as to cover the plurality of metal films 11. The protective film 12 is preferably excellent in heat resistance and low in gas permeability. Moreover, it is preferable that this protective film 12 also transmits light in the visible wavelength region. Therefore, the protective film 12 is preferably made of an oxide of Si, an oxide of Ti, an oxide of Zr, an oxide of Sn, an oxide of Al or a nitride of Si.

The thickness of the protective film 12 is not particularly limited, but can be, for example, about 50 nm to 500 nm.

On the other hand, a transparent conductive film 13 that transmits light in the visible wavelength region is formed on the second main surface 10b. The transparent conductive film 13 substantially covers the entire second main surface 10b. For this reason, in this embodiment, the transparent conductive film 13 is disposed so as to overlap the plurality of metal films 11 in plan view. This transparent conductive film 13 has heat ray reflectivity. The transparent conductive film 13 can be formed of, for example, ITO (Indium Tin Oxide), ATO (Antimony Tin Oxide), FTO (Fluorine-Doped SnO2), or the like.

The thickness of the transparent conductive film 13 is preferably 25 nm or more, and more preferably 200 nm or more. The thickness of the transparent conductive film 13 is preferably 1 μm (= 1000 nm) or less.

As described above, in the heat ray reflective glass plate 1, the metal film 11 mainly bears the heat ray reflectivity. For this reason, for example, if the metal film 11 is transformed due to oxidation or the like, the heat ray reflectivity of the heat ray reflective glass plate 1 is greatly reduced.

Here, for example, when a transparent conductive film is not provided as in the heat ray reflective glass plate described in Patent Document 1, strong heat rays are applied to the metal film. For this reason, the metal film is easily transformed by oxidation. Therefore, it is difficult to realize sufficiently excellent thermal durability.

On the other hand, in the heat ray reflective glass plate 1 of the present embodiment, the transparent conductive film 13 is provided so as to overlap the plurality of metal films 11 in plan view. For this reason, a part of the heat ray from the heat source is reflected by the transparent conductive film 13. Therefore, the intensity of the heat rays applied to the metal film 11 can be reduced. Therefore, since thermal transformation of the metal film 11 can be suppressed, excellent thermal durability can be realized.

Furthermore, in this embodiment, the metal film 11 is covered with the protective film 12. For this reason, the contact between the metal film 11 and the outside air is regulated. Therefore, thermal transformation of the metal film 11 is more effectively suppressed. Therefore, more excellent thermal durability can be realized.

Moreover, in this embodiment, since the transparent conductive film 13 also has heat ray reflectivity, the heat ray reflectivity required for the plurality of metal films 11 is low. Therefore, the area occupation ratio of the plurality of metal films 11 can be reduced, or the metal film 11 can be thinned. Therefore, the visibility through the heat ray reflective glass plate 1 can be further enhanced.

In particular, in this embodiment, the circle equivalent diameter of each metal film 11 is 1 mm or less, and the area occupation ratio of the metal film in the region where the plurality of metal films 11 is provided on the first main surface 10a is 75. % Or less. Therefore, the visibility through the heat ray reflective glass plate 1 is further enhanced. From the viewpoint of further improving the visibility, each metal film 11 preferably has a diameter of 0.5 mm or less. Moreover, it is preferable that the area occupation rate of the metal film 11 in the area | region in which the some metal film 11 of the 1st main surface 10a was provided is 75% or less. However, if the area occupancy of the metal film 11 in the region where the plurality of metal films 11 is provided on the first main surface 10a is too low, the heat ray reflectivity of the heat ray reflective glass plate 1 may be too low. For this reason, it is preferable that the area occupation rate of the metal film 11 in the area | region in which the some metal film 11 of the 1st main surface 10a was provided is 20% or more.

Hereinafter, other examples of preferred embodiments in which the present invention is implemented will be described. In the following description, members having substantially the same functions as those of the first embodiment are referred to by the same reference numerals, and description thereof is omitted.

(Second Embodiment)
FIG. 3 is a schematic cross-sectional view of a part of the heat ray reflective glass plate according to the second embodiment. As shown in FIG. 3, in the heat ray reflective glass plate 2 of this embodiment, the transparent conductive film 13 is not provided on the second main surface 10b, and the protective film is formed on the first main surface 10a. Instead of 12, a transparent conductive film 13 is formed. This heat ray reflective glass plate 2 is arranged and used such that the first main surface 10a side faces the heat source side.

Also in the heat ray reflective glass plate 2 of the present embodiment, the intensity of the heat rays applied to the metal film 11 by the transparent conductive film 13 is reduced. Further, the metal film 11 is isolated from the outside air by the transparent conductive film 13. Therefore, the heat ray reflective glass plate 2 of the present embodiment has excellent thermal durability like the heat ray reflective glass plate 1 of the first embodiment.

(Third embodiment)
FIG. 4 is a schematic cross-sectional view of a part of the heat ray reflective glass plate according to the third embodiment. As shown in FIG. 4, in the heat ray reflective glass plate 3 of this embodiment, transparent

conductive films

13a and 13b are formed on the first and second

main surfaces

10a and 10b of the glass substrate 10, respectively. For this reason, the heat ray reflective glass plate 3 of the present embodiment suppresses the thermal deterioration of the metal film 11 even when the first and second

main surfaces

10a and 10b are arranged so that either side faces the heat source side. can do.

The following evaluation was performed to confirm the performance of the first embodiment of the present invention.

(Experimental example 1)
A glass substrate made of crystallized glass that transmits visible light having a vertical and horizontal dimension of 30 mm and a thickness of 2.0 mm was prepared. In Example 1, a plurality of circular Al metal films having a thickness of 0.5 mm as shown in Table 1 are formed in a matrix arrangement on the first main surface of the glass plate, and the second ITO was formed on the main surface to prepare a test piece. In Comparative Example 1, a test piece was prepared in the same manner as in Example 1 except that the ITO film was not formed.

The area occupation ratio of the circular Al metal film to the first main surface of the glass substrate was 50%.

Next, a hot plate set to 380 ° C. was prepared as a heat source. The sample was held for 5 minutes in a state of being placed so that the first main surface side of the test piece was in contact with the surface of the hot plate. Thereafter, the surface temperature of the surface not in contact with the hot plate (hereinafter referred to as the back surface) with respect to the surface in contact with the hot plate (hereinafter referred to as the surface) was measured with a thermocouple. The results are shown in Table 1 below.

In the test piece of Comparative Example 1, an Al metal film having a thickness of 250 nm was formed as a metal film on the back surface of the glass substrate with respect to the heat source, and the temperature of the surface of the Al metal film was 320 ° C.

On the other hand, in Example 1, an ITO film having a thickness of 250 nm was formed on the surface of the glass substrate so as to overlap the Al metal film. The temperature of the surface of the Al metal film was 310 ° C., which was higher than that of Comparative Example 1. It was low. That is, the temperature was lower in Example 1 than in Comparative Example 1 by forming the ITO film. From this result, it is understood that heat can be effectively shielded by providing the ITO film.

On the other hand, in Comparative Example 1, the temperature of the surface of the Al film was higher than that in Example 1 even when held for only 5 minutes, and there was a risk of causing trouble in thermal durability when held for a long period of time. .

(Experimental example 2)
About the test piece of Comparative Example 2 having the film structure shown in Table 2 and each sample piece of Example 2, crystallized glass installed in an electric furnace set in advance at 475 ° C. (Neoceram manufactured by Nippon Electric Glass)
After placing the top and bottom of the film structure on the plate in the direction shown in Table 2 and holding for 24 hours, the appearance was visually observed.

In Comparative Example 2, a test piece having the same film configuration as Comparative Example 1 was used. In Comparative Example 2, since the test piece was heated for a long time, it was found that the Al metal film lost the metallic luster and was thermally deteriorated by visual observation and became white turbid (whitened).

On the other hand, in Example 2, in addition to the film configuration of the test piece of Example 1, a SiN (silicon nitride) film having a thickness of 100 nm was further formed on the Al metal film as a protective film. In the test piece of Example 2, the metallic luster of the Al metal film was not lost even after the test, and no change was observed.

DESCRIPTION OF SYMBOLS 1-3 ... Heat ray reflective glass plate 10 ... Glass substrate 10a ... 1st main surface 10b ... 2nd main surface 11 ... Metal film 12 ...

Protective film

13, 13a, 13b ... Transparent electrically conductive film

Claims

A glass substrate having first and second main surfaces;
A metal film formed on the first main surface and spaced from each other;
A transparent conductive film formed on at least one of the first and second main surfaces so as to overlap the metal film in plan view;
A heat ray reflective glass plate.
The transparent conductive film is formed on the second main surface,
Si oxide, Ti oxide, Zr oxide, Sn oxide, Al oxide or Si nitride formed on the first main surface so as to cover the metal film The heat ray reflective glass plate according to claim 1, further comprising a protective film comprising:
The heat ray reflective glass plate according to claim 1, wherein the transparent conductive film is formed on the first main surface so as to cover the metal film.
4. The metal film according to claim 1, wherein the metal film is made of a metal selected from the group consisting of Al, Cu, and Ag, or an alloy containing one or more metals selected from the group consisting of Al, Cu, and Ag. The heat ray reflective glass plate according to one item.
The heat ray reflective glass plate according to any one of claims 1 to 4, wherein the transparent conductive film contains indium, tin, or zinc.
The heat ray reflective glass plate according to any one of claims 1 to 5, wherein the metal film has a circular or polygonal shape having an equivalent circle diameter of 1 mm or less.
The heat ray reflective glass plate according to any one of claims 1 to 6, wherein an area occupancy of the metal film in a region where the metal film is provided on the first main surface is 75% or less.