JP2008105297A - Heat ray reflective substrate and method for manufacturing it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat ray reflective substrate having both high transparency and excellent heat ray reflective characteristics, and excellent antiweatherability, and also to provide a method for manufacturing it. <P>SOLUTION: The heat ray reflective substrate 10 is formed by arranging a tin-added indium oxide film (heat ray reflective film) 12, a heat-resistant film 13, and a silicon dioxide film (weather-resistant film) 14 successively laminated in this order on a substrate 11. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a heat ray reflective substrate having high transparency and excellent heat ray reflection characteristics, and a method for producing the same.

  Conventionally, as a heat ray reflective glass heat ray reflective base material provided with infrared reflective performance, heat ray reflective glass is mentioned, for example. As this heat ray reflective glass, for example, a metal film such as silver (Ag) or nickel-chromium (Ni-Cr) is formed on a resin film by vapor deposition or the like, and this resin film is attached to a glass substrate. Forms are known.

  The heat ray reflective glass is an energy-saving high-performance glass in which a laminated film or a tempered glass is covered with a heat ray reflective film by bonding the resin film as described above to a glass substrate. When this heat-reflective glass is applied to the window glass of an automobile or a house, the heat-ray reflective film shields the radiant heat (sunlight) of the sun, and greatly reduces the cooling load when using an air conditioner, for example. Can do. Moreover, the heat ray reflective film can reduce local temperature rise and glare, and can create a comfortable interior space for driving in summer. As such a heat ray reflective film, for example, tin-added indium oxide (ITO) is known.

Conventionally, since a heat ray reflective film made of tin-added indium oxide is inferior in weather resistance, it has been provided on the back surface of the glass substrate (the surface on the side where light transmitted through the glass substrate is reflected).
When the heat ray reflective film is provided on the back surface of the glass base material, there is a problem that the glass base material is heated by the heat rays reflected by the heat ray reflective film, and the inside (inside the vehicle or indoors) is warmed by the influence. Therefore, by providing a thin film made of silicon dioxide (SiO ₂ ) on the heat ray reflective film made of tin-added indium oxide and arranging the heat ray reflective film imparted with weather resistance on the back side, the inside (in-car or indoor) ) Has been devised to prevent warming (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 2-901

  By the way, although the heat ray reflective film which consists of tin addition indium oxide shows the outstanding heat ray reflective characteristic, when exposed to high temperature of 300 degreeC or more, it is known that a heat ray reflective characteristic will fall. Therefore, when a thin film of silicon dioxide is provided on a heat ray reflective film made of tin-added indium oxide, there has been a problem that heat ray reflection characteristics are deteriorated.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a heat ray reflective base material having high transparency and excellent heat ray reflection characteristics, and having excellent weather resistance, and a method for producing the same.

  The heat ray reflective substrate according to claim 1 of the present invention is characterized in that a tin-added indium oxide film, a heat-resistant film, and a silicon dioxide film are sequentially stacked on the substrate.

  The heat-warf reflective substrate according to claim 2 of the present invention is characterized in that the heat-resistant film is one selected from the group consisting of a fluorine-added tin oxide film, an antimony-added tin oxide film, and a tin oxide film.

  The heat ray reflective substrate according to claim 3 of the present invention is characterized in that, in claim 1, the thickness of the silicon dioxide film is 10 nm or more and 1000 nm or less.

  The manufacturing method of the heat ray reflective substrate according to claim 4 of the present invention includes a first step of forming a tin-added indium oxide film on the substrate, and a second step of forming a heat-resistant film on the tin-added indium oxide film. A heat ray reflective substrate manufacturing method comprising at least a step and a third step of forming a silicon dioxide film on the heat-resistant film, wherein in the first step and / or the second step, spray pyrolysis It is characterized by using a method.

  In the heat ray reflective substrate of the present invention, since a tin-added indium oxide film, a heat-resistant film, and a silicon dioxide film are sequentially stacked on the substrate, only the tin-added indium oxide film is provided on one surface of the glass substrate. It has high transparency equivalent to that of the obtained heat ray reflective glass and excellent heat ray reflection characteristics, and also has excellent weather resistance.

  The method for producing a heat ray reflective substrate of the present invention includes a first step of forming a tin-added indium oxide film on the substrate, a second step of forming a heat-resistant film on the tin-added indium oxide film, and the heat-resistant film. A method for producing a heat ray reflective substrate comprising at least a third step of forming a silicon dioxide film on the film, wherein a spray pyrolysis method is used in the first step and / or the second step. It is possible to obtain a heat ray reflective substrate having both high transparency equivalent to that of a heat ray reflective glass in which only a tin-added indium oxide film is provided on one surface of the glass substrate and excellent heat ray reflection characteristics, and excellent weather resistance.

  Hereafter, the heat ray reflective base material which implemented this invention and its manufacturing method are demonstrated in detail.

FIG. 1 is a schematic cross-sectional view showing an embodiment of a heat ray reflective substrate according to the present invention.
The heat ray reflective base material 10 of this embodiment includes a base material 11, a tin-added indium oxide film 12, a heat-resistant film 13, and a silicon dioxide film 14 that are sequentially stacked on one surface 11 a of the base material 11. It is roughly structured.

  Examples of the substrate 11 include transparent resin substrates such as polyethylene terephthalate (PET) and polycarbonate, and glass substrates.

The tin-added indium oxide film (heat ray reflective film) 12 is a transparent and conductive film made of tin-added indium oxide (Indium Tin Oxide, hereinafter abbreviated as ITO).
The thickness of the ITO film 12 is not particularly limited, but is preferably 20 nm or more and 2000 nm or less, and more preferably 100 nm or more and 1000 nm or less.

The heat-resistant film 13 includes fluorine-added tin (Fluorine doped Tin Oxide, hereinafter abbreviated as FTO), antimony-added tin oxide (hereinafter referred to as ATO), tin oxide (Tin Oxide, hereinafter referred to as TO). A transparent and electrically conductive film selected from the group of the abbreviations), and among these, FTO is preferred in terms of heat resistance.
The thickness of the heat-resistant film 13 is not particularly limited, but is preferably 5 nm or more and 300 nm or less, and more preferably 20 nm or more and 150 nm or less.

The silicon dioxide film (weather-resistant film) 14 is a transparent film made of silicon dioxide (SiO ₂ ).
The thickness of the silicon dioxide film 14 is preferably 10 nm or more and 1000 nm or less, and more preferably 50 nm or more and 500 nm or less.
If the thickness of the silicon dioxide film 14 is less than 10 nm, defect sites are generated on the silicon dioxide film, and the weather resistance is lost. On the other hand, when the thickness of the silicon dioxide film 14 exceeds 1000 nm, transparency is impaired.

  In this embodiment, the heat ray reflective base material 10 in which the ITO film 12, the FTO film 13, and the silicon dioxide film 14 are sequentially stacked on the one surface 11a of the base material 11 is exemplified. The reflective substrate is not limited to this. In the heat ray reflective base material of the present invention, an ITO film, an FTO film, and a silicon dioxide film may be sequentially stacked on both surfaces of the base material.

  In the heat ray reflective substrate 10 of this embodiment, since the ITO film 12, the heat-resistant film 13, and the silicon dioxide film 14 are sequentially stacked on the substrate 11, only the ITO film is provided on one surface of the glass substrate. It has high transparency equivalent to that of the obtained heat ray reflective glass and excellent heat ray reflection characteristics, and also has excellent weather resistance. Therefore, since the heat ray reflective substrate 10 can use the surface on which the ITO film 12 and the heat resistant film 13 are provided as the surface, it is more excellent in heat ray reflection characteristics.

Next, the film-forming apparatus used for the manufacturing method of the heat ray reflective base material of this invention is demonstrated.
FIG. 2 is a schematic configuration diagram showing a film forming apparatus using a spray pyrolysis method, which is used in the method for producing a heat ray reflective substrate of the present invention.
The film forming apparatus 20 is a film forming apparatus that forms a thin film on one surface of the object to be processed 23 by spray pyrolysis, and includes, for example, a supporting unit 22 for placing the object to be processed 23 made of a glass substrate. The spraying means 24 for spraying the mist 27 made of the raw material solution of the thin film toward one surface of the object to be processed 23 and the upper and lower sides of the object to be processed 23 or both the upper and lower sides thereof are disposed. One or more heating means 25, 28 (hereinafter also referred to as first heating means 25, second heating means 28) and first heating means 25 (25A, 25B) that are heated by electromagnetic waves are controlled to be processed 23. Control means P1 and P2 that fluctuate the temperature within a predetermined range (periodically).

The film forming apparatus 20 includes openings 21 a and 21 b for carrying in and carrying out the object 23 placed on the support means 22.
In order to prevent adhesion of droplets sprayed from the discharge means 24, an adhesion preventing member 26 made of, for example, a quartz glass plate is disposed below the first heating means 25 and facing the substrate 23. Has been.

  The film formation chamber 21 is installed to stably form a thin film on the object 23 during film formation by the spray pyrolysis method. It is not limited to the configuration of 2. In other words, the film forming chamber 21 maintains the flow and temperature of the droplet 27 sprayed toward the object to be processed 23, and the object to be processed 23 placed on the support means 22 and the droplets attached thereon. This also contributes to temperature maintenance or temperature control of 27 '. Therefore, the material constituting the film forming chamber 21 is not particularly limited, but a material having an excellent heat retaining effect is preferable.

  The support means 22 is, for example, a plate-shaped one whose main component is an infrared absorbing material having a surface on which the object 23 is placed is at least a flat surface and excellent in infrared absorbing ability. As such an infrared absorbing material, one or more selected from the group of carbon, iron, titanium and tungsten are preferable. By adjusting the heat capacity by selecting the material, thickness, volume, and shape of the base plate 2, high-speed heating can be performed while maintaining a uniform temperature distribution.

The 1st heating means 25 (25A, 25B) is for heating the to-be-processed object 23 from the film-forming surface side, For example, an infrared lamp, a far-infrared lamp, heating air, etc. are used suitably.
By selecting the average heating heat amount per unit cross-sectional area and the type of lamp, the average heating heat amount of infrared rays and the type of infrared rays can be controlled widely.
In FIG. 2, the first heating means 25 (25A, 25B) are provided on both sides of the spray nozzle that forms the top plate of the film forming chamber 21 and the tip of the discharge means 24. By selecting, it becomes possible to control the heat convection from the to-be-processed object 23, and can control the flow of the droplet 27 sprayed from a spray nozzle by extension.

Although the example which provided the two 1st heating means 25 (25A, 25B) was shown in FIG. 2, the number is not specifically limited. The first heating means 25 does not have to be the same type of light source, and lamps as described below may be used in combination.
For example, when the average heating heat per unit sectional area of the infrared lamp is ² to 30 W / cm ² , the lamp is a near infrared lamp (wavelength: 2.5 μm or less), a medium wavelength infrared lamp (wavelength: 2.5 to 25 μm). ), A far-infrared lamp (wavelength: 25 μm or more) may be appropriately selected.

  The first heating means 25 (25A and 25B) are connected to power sources P1 and P2 that supply power via lines L1 and L2, respectively. At this time, the lines L1 and L2 are not limited to wires, and may be wireless. The power sources P1 and P2 control the first heating means 25 (25A and 25B) individually or in synchronization, so that the light intensity that the first heating means 25 (25A and 25B) irradiates toward the object 23 is processed. Is changed sequentially. Therefore, the first heating unit 25 (25A, 25B) also functions as a control unit that fluctuates (periodically) the temperature of the object 23 within a predetermined range.

  The second heating means 28 plays a role of heating the support means 22 from the back side and heating and holding the temperature of the object 23 via the support means 22. If the supporting means 22 on which the object 23 is placed is mainly composed of an infrared absorbing material having excellent infrared absorbing ability as described above, the second heating means 28 may be, for example, an infrared heater having a predetermined high temperature. It is suitable for the case. Further, when the temperature is varied, the above-described various types of infrared lamps may be appropriately disposed in the same manner as the first heating means 25. By disposing the second heating unit 28 below the support unit 22, it becomes easy to keep the temperature of the object to be processed 23 in a predetermined temperature range, and the surface temperature distribution can be made more uniform.

Below, the film-forming method which forms a thin film on one surface of the to-be-processed object 23 (base material 11) by the spray pyrolysis method using the film-forming apparatus 20 mentioned above is demonstrated.
First, the target object 23 made of a glass substrate having a clean surface is placed on the support means 22, and this target object 23 is carried together with the support means 22 from the opening 21 a into the film forming chamber 21. , Hold in place.
Subsequently, the to-be-processed object 23 is heated from upper direction (film-forming surface side) using the 1st heating means 25, and the surface temperature of the to-be-processed object 23 is hold | maintained in the temperature range required for film-forming.
At that time, since the support means 22 is also irradiated with infrared rays by the first heating means 25, the infrared rays are absorbed with high efficiency to generate heat, and the workpiece 23 is heated from below.
Along with the heating by the first heating means 25, the support means 22 is also heated by the second heating means 28 from below (the back side).

  Thus, since the to-be-processed object 23 which consists of a glass base material is heated from the up-and-down both directions substantially simultaneously, the surface temperature of the to-be-processed object 23 will rise rapidly until it becomes a predetermined temperature range. Further, as described above, the first heating means 25 (25A, 25B) sequentially changes the light intensity applied to the object to be processed 23, whereby the object to be processed 23 falls within a predetermined range ( Periodically).

  Next, a solution that is a raw material of the film is sprayed as droplets 27 from the spray nozzle of the discharge means 24 onto the object to be processed 23, and the droplets 27 ′ are adhered to the object to be processed 23. A thin film is formed on the target object 23 by being heat-treated from the target object 23 heated to a predetermined temperature.

Next, the manufacturing method of the heat ray reflective base material of this invention is demonstrated.
First, the ITO film 12 is formed on the base material 11 described above by the spray pyrolysis method using the film forming apparatus 20 described above (first step).
In the first step, a solution containing a component that becomes a conductive metal oxide of ITO by heating is used as the raw material solution.
As this solution, for example, a solution in which indium (III) chloride tetrahydrate (InCl ₃ .4H ₂ O) and tin (II) chloride hydrate (SnCl ₂ .2H ₂ O) are dissolved in ethanol is used. Preferably used.

  The solution as a raw material of the ITO film 12 is rapidly heated by the first heating means 25 while being sprayed as the droplets 27, and the heated droplets 27 are heated to a predetermined temperature. By adhering to the surface of the object to be processed 23 (base material 11), the solvent in the droplet 27 rapidly evaporates, and the remaining solute rapidly undergoes a chemical reaction to change into a conductive metal oxide of ITO. To do. Thereby, the crystal | crystallization which consists of an electroconductive metal oxide produces | generates rapidly on the surface of the to-be-processed object 23 (base material 11), and the ITO film | membrane 12 will be formed in a short time.

  At this time, when the ITO film 12 is formed on the target object 23 (base material 11) while the surface of the target object 23 (base material 11) is fluctuated (periodically) within a predetermined temperature range, the target object 23 (base material 11) is changed. The ITO film 12 is formed on the surface of the treatment body 23 (base material 11) in a short time. In other words, when the droplet 27 made of the raw material solution of the ITO film 12 is sprayed from the ejection unit 24 toward one surface of the target object 23 (base material 11) placed on the support means 22, the target object The ITO film 12 is formed on the object to be processed 23 (base material 11) while changing the base material 11 (base material 11) within a predetermined temperature range (periodically).

  Moreover, when forming the ITO film | membrane 12, as a temperature range of the fluctuation | variation of the to-be-processed object 23 (base material 11), 240-450 degreeC is preferable, More preferably, it is 280-420 degreeC, Optimally 300-410 degreeC. is there. The period range of temperature fluctuation is preferably 2 to 200 seconds / cycle, more preferably 2 to 100 seconds / cycle, and most preferably 2 to 40 seconds / cycle.

Next, the heat-resistant film 13 is formed on the ITO film 12 formed on the substrate 11 by the spray pyrolysis method using the film forming apparatus 20 described above (second step).
In the second step, a solution containing a component that becomes a conductive metal oxide such as FTO, ATO, or TO by heating is used as a solution that is a raw material.
Examples of the solution include an aqueous solution containing 0.2 mol / liter of tin chloride pentahydrate, or an ethanol solution, and further an aqueous solution containing 1.2 mol / liter of ammonium fluoride with respect to the ethanol-water mixed solution. Alternatively, a mixed solution obtained by adding an ethanol solution or an ethanol-water mixed solution is preferably used.

  The solution as a raw material of the heat-resistant film 13 is rapidly heated by the first heating means 25 while being sprayed as the droplets 27, and the target object in which the heated droplets 27 are heated to a predetermined temperature. By adhering to the surface of the ITO film 12 formed on the surface 23, the solvent in the droplet 27 rapidly evaporates, and the remaining solute rapidly reacts and changes into a conductive metal oxide of FTO. As a result, crystals made of a conductive metal oxide are quickly generated on the surface of the ITO film 12 formed on the object 23, and the heat-resistant film 13 is formed in a short time.

  At that time, when the heat-resistant film 13 is formed on the ITO film 12 while the surface of the ITO film 12 formed on the object to be processed 23 is fluctuated (periodically) within a predetermined temperature range, The FTO film 12 having excellent heat ray reflection performance with respect to near infrared rays can be formed on the surface in a short time. In other words, when the droplets 27 made of the raw material solution of the heat-resistant film 13 are sprayed from the ejection unit 24 toward one surface of the ITO film 12 formed on the target object 23 placed on the support unit 22, The heat-resistant film 13 is formed on the ITO film 12 formed on the target object 23 while the target object 23 (base material 11) is changed (periodically) within a predetermined temperature range.

Moreover, when forming the heat-resistant film | membrane 13, as a temperature range of the fluctuation | variation of the to-be-processed object 23 (base material 11), 240-450 degreeC is preferable, More preferably, it is 270-420 degreeC, Optimally 280-410 degreeC. is there. As the latter temperature range is selected, the heat resistant film 13 having a higher reflectance in the near infrared ray having a wavelength of 2000 nm is obtained.
The period range of temperature fluctuation is preferably 2 to 200 seconds / cycle, more preferably 2 to 100 seconds / cycle, and most preferably 2 to 40 seconds / cycle. As the latter periodic range is selected, the heat-resistant film 13 having excellent reflection characteristics in the wavelength range of 1500 to 5000 nm tends to be formed.

  In addition, the to-be-processed object 23 (base material 11) which consists of a glass base material with which the ITO film | membrane 12 and the heat-resistant film | membrane 13 were formed into a film is conveyed to the exterior of the film-forming chamber 21 from the opening part 21b with every support means 22, and predetermined Stored in position.

Next, a silicon dioxide film 14 is formed on the heat-resistant film 13 formed on the ITO film 12 by a dip coating method that is one of sol-gel methods (third step).
In this third step, tetraethoxysilane (Si (OC ₂ H ₅ ) ₄ ), ethanol, and water (pH adjusted with hydrogen chloride) are refluxed at 60 to 90 ° C. for 12 to 24 hours, A raw material solution is prepared.
And the base material 11 in which the ITO film | membrane 12 and the heat-resistant film | membrane 13 were provided is immersed in the obtained raw material solution, and it coats on the surface of the base material 11 at normal temperature (20-25 degreeC) and relative humidity about 50% environment. The silicon dioxide film 14 is formed on the heat-resistant film 13 by naturally drying to form a gel film and heating at 400 to 500 ° C. for 0.5 to 1 hour.

  In this embodiment, the spray pyrolysis method is used to form the ITO film 12 and the heat-resistant film 13, but the method for manufacturing the heat ray reflective substrate of the present invention is not limited to this. In the method for producing a heat ray reflective substrate of the present invention, either the formation of the ITO film 12 or the formation of the heat resistant film 13 is performed only by using the spray pyrolysis method, and the heat ray reflective substrate having excellent heat ray reflection characteristics. A material can be produced.

  The manufacturing method of the heat ray reflective substrate of this embodiment includes the first step of forming the ITO film 12 on the substrate 11, the second step of forming the heat resistant film 13 on the ITO film 12, A method for producing a heat ray reflective substrate 10 comprising at least a third step of forming a silicon dioxide film 14 thereon, wherein a spray pyrolysis method is used in the first step and / or the second step. A heat ray reflective substrate 10 having both high transparency equivalent to that of a heat ray reflective glass in which only a tin-added indium oxide film is provided on one surface of the material and excellent heat ray reflection characteristics and excellent weather resistance can be produced.

(Experimental example)
Hereinafter, although the result of having produced a heat ray reflective base material by the manufacturing method of the heat ray reflective base material mentioned above and evaluating the various characteristics is explained, these experiment examples are made concretely in order to understand the present invention more. However, the present invention is not limited to these experimental examples.

First, in order to form an ITO film, an FTO film, and a silicon dioxide film on a substrate made of a glass member, a raw material solution was prepared as follows.
<Preparation of ITO raw material solution>
The solution used as the raw material for the ITO film was 16.7 g of indium chloride (III) tetrahydrate (InCl ₃ .4H ₂ O, molecular weight: 293.24) and tin (II) chloride hydrate (SnCl ₂ .2H). ₂ O, molecular weight: 225.65) was prepared by the 1.05g dissolved in ethanol 300 ml.
<Preparation of FTO raw material solution>
The solution used as the raw material of the FTO film was dissolved in a ratio of 60 ml of ethanol aqueous solution to 4.21 g of tin (IV) chloride pentahydrate (SnCl ₄ .5H ₂ O, molecular weight: 350.60). Prepared by adding 3.55 g of saturated aqueous solution of ammonium chloride (NH ₄ F, molecular weight: 37.04) and dissolving this mixture with ultrasound over about 20 minutes.
<Preparation of silicon dioxide raw material solution>
The solution used as the raw material for the silicon dioxide film was 20 g of tetraethoxysilane (Si (OC ₂ H ₅ ) ₄ ) 16 g, ethanol 8.5 g, and water (pH adjusted with hydrogen chloride) 5.5 g at 80 ° C. After refluxing for an hour, 78 g of isopropyl alcohol was added thereto, and the mixture was further stirred at room temperature for 8 hours.

(Experimental example 1)
Using a heat-resistant glass substrate as the object to be processed 23, the surface temperature of the object to be processed 23 at the time of film formation is controlled so as to fluctuate in a temperature range of 320 ° C. to 380 ° C. with 350 ° C. being the central temperature, A heat ray reflective glass (sample A) provided on the object to be processed was prepared.
At that time, an infrared lamp was used as the first heating means 25 (25A, 25B), and the workpiece 23 was heated from above. In addition, the temperature fluctuation is caused by supplying power P1 and P2 for supplying power to the first heating means 25 (25A and 25B) via the lines L1 and L2, respectively, while keeping the temperature of the object 23 within a predetermined range ( Used as a control means to change periodically). Further, as the second heating means 28, a hot plate (HP) is provided, and the object 23 is indirectly heated by the hot plate (HP) via the support means 22.
In addition, as the to-be-processed object 23, the 300 mm square and 1.1 mm-thick heat resistant glass substrate was used.
As the infrared lamp that constitutes the first heating means 25, eight medium-wavelength infrared lamps (wavelength: 2.5 to 25 μm, lamp length: 600 mm) of three phases and 5 kW arranged in parallel with each other are used as the second heating means. As the 28 hot plates (HP), 200V3 phase 5.5 kW and 400 mm square plates were used.

(Experimental example 2)
The heat-resistant glass substrate similar to Experimental Example 1 is used as the object to be processed 23, and the surface temperature of the object to be processed 23 at the time of film formation varies in a temperature range of 380 ° C. to 420 ° C. with 400 ° C. as the central temperature. Except for control, a heat ray reflective glass (sample B) in which an FTO film was provided on an object to be processed was prepared in the same manner as in Experimental Example 1.

(Experimental example 3)
As the object to be processed 23, the heat ray reflective glass A obtained in Experimental Example 1 is used, and the surface temperature of the object to be processed 23 at the time of film formation varies in a temperature range of 380 ° C. to 420 ° C. with 400 ° C. as the central temperature. A heat ray reflective glass (sample C) in which an FTO film was provided on an object to be processed was prepared in the same manner as in Experimental Example 1 except that the control was performed as described above.

(Experimental example 4)
As the object to be processed 23, the heat ray reflective glass A obtained in Experimental Example 1 is used. The heat ray reflective glass A is immersed in a silicon dioxide raw material solution, coated on the surface of the thermal warfare reflective glass A, and naturally dried. After forming the gel film, the film was heated at 480 ° C. for 1 hour to produce a heat ray reflective glass (sample D) in which a silicon dioxide film was provided on the object to be processed.

(Experimental example 5)
As the object to be processed 23, the heat ray reflective glass B obtained in Experimental Example 2 was used. The heat ray reflective glass B was immersed in a silicon dioxide raw material solution and heated at 480 ° C. for 1 hour to cover the silicon dioxide film. A heat ray reflective glass (sample E) provided on the treated body was produced.

(Experimental example 6)
As the object to be processed 23, the heat ray reflective glass C obtained in Experimental Example 3 was used. The heat ray reflective glass C was immersed in a silicon dioxide raw material solution and heated at 480 ° C. for 1 hour to cover the silicon dioxide film. A heat ray reflective glass (sample F) provided on the treated body was produced.

For samples A to F, sheet resistance (Ω / □), film thickness (nm), specific resistance (Ω · cm), and total light transmittance (%) were measured.
The four-terminal method was used for measurement of sheet resistance and specific resistance.
The total light transmittance was measured using an ultraviolet-visible spectrophotometer.
The film thickness was measured by direct measurement by cross-sectional observation of a scanning electron microscope (SEM) image.
The results are shown in Table 1.

Moreover, the result of having investigated the light reflection characteristic in the wavelength range of 200-2400 nm about sample A-F is shown in FIG.3, FIG.4, FIG.5.
From the results shown in FIG. 3, it was confirmed that in the sample D in which the silicon dioxide film was directly formed on the ITO film, the light reflection characteristics were remarkably deteriorated.
However, from the result of FIG. 4, it was confirmed that the sample F in which the silicon dioxide film was formed on the ITO film via the FTO film showed the same light reflection characteristics as the sample A in which only the ITO film was formed. Moreover, from the result of FIG. 4, the sample C and the sample F showed the reflection characteristic of the substantially same light, and the result of Table 1 confirmed that the total light transmittance of the sample F was 80% or more.
From the result of FIG. 5, the sample B in which only the FTO film is formed and the sample E in which the silicon dioxide film is formed on the FTO film cannot obtain satisfactory reflection characteristics.

  According to the present invention, a heat ray reflective base material having high transparency and excellent heat ray reflection characteristics can be obtained. Such a heat ray reflective base material is used for, for example, a viewing window such as a microwave oven and a microwave oven, a fire spread prevention glass application, an infrared reflection glass (security) application, etc. Widely applicable to.

It is a schematic sectional drawing which shows one Embodiment of the heat ray reflective base material which concerns on this invention. It is a schematic block diagram which shows the film-forming apparatus by the spray pyrolysis method used for the manufacturing method of the heat ray reflective base material of this invention. It is a graph which shows the result of having investigated the light reflection characteristic in the wavelength range of 200-2400 nm about the heat ray reflective glass produced in Experimental example 1 and 4. FIG. It is a graph which shows the result of having investigated the light reflection characteristic in the wavelength range of 200-2400 nm about the heat ray reflective glass produced in Experimental example 3 and 6. FIG. It is a graph which shows the result of having investigated the light reflection characteristic in the wavelength range of 200-2400 nm about the heat ray reflective glass produced in Experimental example 2 and 5. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Heat ray reflective base material, 11 ... Base material, 12 ... Tin addition indium oxide film, 13 ... Heat-resistant film, 14 ... Silicon dioxide film.

Claims (4)

  A heat ray reflective base material, wherein a tin-added indium oxide film, a heat-resistant film, and a silicon dioxide film are sequentially stacked on the base material.   2. The heat ray reflective substrate according to claim 1, wherein the heat-resistant film is one selected from the group consisting of a fluorine-added tin oxide film, an antimony-added tin oxide film, and a tin oxide film.   2. The heat ray reflective substrate according to claim 1, wherein the silicon dioxide film has a thickness of 10 nm or more and 1000 nm or less. A first step of forming a tin-added indium oxide film on the substrate; a second step of forming a heat-resistant film on the tin-added indium oxide film; and a third step of forming a silicon dioxide film on the heat-resistant film. A method of manufacturing a heat ray reflective substrate comprising at least a process,
In the first step and / or the second step, a spray pyrolysis method is used.

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