JPS63265844A - Production of bent heat ray reflecting glass - Google Patents

Abstract

PURPOSE:To obtain the title glass without generating a film defect and having an excellent optical characteristic by bending a glass substrate with an absorbing film including a metal nitride coated film on the surface in a nonoxidizing atmosphere. CONSTITUTION:A target 22 of Cr, etc., is fixed to the lower surface of a magnetron cathode 15 at the upper part of a grounded vacuum vessel 11, a target 23 of Ti, etc., is fixed to the lower surface of a magnetron cathode 16, and the glass substrate 26 is placed on the substrate holder 25 on a conveyor belt 21. A variable valve 12 is then opened to depressurize the inside of the vessel 11, N2 is supplied from a gas supply pipe 10, the valve 12 is closed, a negative voltage is impressed on the cathodes 15 and 16, the substrate 26 is moved below the cathode 15 and then below the cathode 16 to form the absorbing layer contg. a metal nitride and having 200-1,000Angstrom thickness on the substrate 26, and the heat ray reflecting glass 39 is obtained. The glass 39 is set on a bending stand 40 in an electric furnace and heated to 600-750 deg.C, gases are supplied from cylinders 33 and 34 to form a nonoxidizing atmosphere, and the glass is bent to obtain the product having 20-70cm radius of curvature.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for manufacturing bent heat ray reflective glass, and more particularly to a method for easily manufacturing bent heat ray reflective glass with high characteristics at low cost.

[Background Art] In recent years, heat-reflecting glass that reflects sunlight has been used for window glasses of buildings, houses, automobiles, etc. Heat-reflecting glass reflects solar heat, prevents indoor temperatures from rising, blocks direct sunlight to prevent glare, protects privacy from outsiders, and has other effects such as adding aesthetic appeal to buildings. It is also attracting attention as a material for various window glass.

BACKGROUND ART Conventionally, heat-reflecting glass generally includes a glass substrate with an absorbing film such as a chromium nitride film formed on the surface of the glass substrate.

[Problems to be Solved by the Invention] Conventionally, all of the heat-reflecting glasses provided are flat, but curved heat-reflecting glass may be required depending on the object of construction.

The following two methods can be considered as methods for manufacturing curved heat ray reflective glass.

■ Forming an absorbing film such as a chromium nitride film on a bent glass substrate.

■ Bending ordinary heat-reflecting glass coated with an absorbing film such as a chromium nitride film.

Method (2) above has already been implemented, but when forming an absorbing film, it is not possible to use a normal film forming apparatus for flat plates, and special measures are required for the apparatus, which increases the equipment cost. , its operation control becomes complicated and productivity deteriorates.

In addition, when cleaning and drying glass substrates as pretreatment for film formation, it is difficult to process curved plates, so sufficient treatment cannot be performed, resulting in deterioration of film quality due to incomplete pretreatment. Specifically, problems such as an increase in pinholes in the film, an increase in color unevenness in the film, an increase in haze, and a decrease in film adhesion tend to occur, and it is originally extremely difficult to form a film on a curved plate. , variations in characteristics may occur on the substrate, making it extremely difficult to manufacture high-quality products.

On the other hand, method (2) does not have the above problems, but when glass with an absorbing film is bent in the same way as ordinary transparent glass, the absorbing film changes color and optical properties such as heat ray reflection performance deteriorate. Therefore, method (2) has not been put into practical use to date.

[Means for Solving the Problems] The present invention can be manufactured efficiently at low cost using a normal film forming apparatus for flat plates, and there is extremely little deterioration in optical properties due to bending, resulting in high quality. Provided is a method for manufacturing bent heat ray reflective glass that can be used as a product, the method comprising forming an absorbing film containing a metal nitride film on the surface of a glass substrate, and then bending the glass in a non-oxidizing atmosphere. The gist of the present invention is a method for manufacturing bent heat ray reflective glass characterized by the following.

Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a sectional view showing one embodiment of the bent heat ray reflective glass manufactured by the present invention.

As shown in the figure, bent heat ray reflective glass 1 manufactured according to the present invention
In this example, a metal nitride film (hereinafter sometimes referred to as "first film") 3 is formed on the surface of a glass substrate 2. As the metal nitride for the first film, chromium nitride (cr XX ), titanium nitride (TiNx), or titanium aluminum nitride (T i AuNX) is suitable.

In the present invention, the thickness of the metal nitride coating 3 is appropriately determined so as to obtain the desired heat reflecting ability.
Generally, the number of participants is about 200 to 1,000. In particular, when forming a chromium nitride film as the metal nitride film 3,
00 to 800 people, 3 when forming a titanium nitride film
It is best to have a thickness of about 00 to 1000 people.

In the present invention, as shown in FIG. 2, an overcoat layer (hereinafter sometimes referred to as a "second coating") of a metal oxide coating 4 is optionally provided on the metal nitride coating 3. .) may be formed. In this case, titanium oxide or tin oxide is suitable as the metal oxide.

Such a metal oxide coating improves the durability, optical properties, etc. of the obtained bent heat ray reflective glass. Therefore, the thickness is determined depending on the required characteristics, but is generally about 10 to 500 people.

In order to manufacture such bent heat ray reflective glass by the method of the present invention, first, a flat glass substrate is used, and a metal nitride film, which is the first film, is formed on the surface of the glass substrate by a conventional method.
If necessary, a second metal oxide film is further formed thereon.

Vacuum deposition method, sputtering method, etc. can be adopted as a method for forming the film, but for example, it is preferable to form the first and second films continuously using a sputtering apparatus as shown in FIG. It's advantageous.

The sputtering apparatus shown in FIG. 3 has an exhaust port 1 provided with a barrier pull valve 12 in a part of a grounded vacuum chamber 11.
3 and is connected to a vacuum pump 14 via this exhaust port 13 to reduce the pressure inside the vacuum chamber 11. In addition, a magnetron cathode 1 is placed at the top of the vacuum chamber 11.
5, 16° 17 are provided, and these are connected to a DC power source 18. Further, a gas supply pipe 20 equipped with a valve 19 is provided between the magnetron cathodes 15 and 16.
It is configured to supply gas into the vacuum chamber 11.

Furthermore, a reciprocating conveyor belt 21 is disposed below each cathode 15, 16, 17.

To form a film using a sputtering apparatus having such a configuration, for example, the following method is used.

A target 22 (for example, Cr) for forming a first film is attached to the lower surface of the cathode 15, and a target 23 (for example, Ti) for forming a second film is attached to the lower surface of the cathode 16. On the other hand, a glass substrate 26 is placed on the substrate holder 25 on the transport heald 21.

Next, the barrier pull valve 12 is opened to reduce the pressure inside the vacuum chamber 11, and after nitrogen is supplied from the gas supply pipe 10, the barrier pull valve 12 is closed and the pressure inside the vacuum chamber 11 is set to a predetermined nitrogen atmosphere.

Next, a negative voltage is applied to the cathode 15 and the glass substrate 26 is
is moved under the cathode 15 six times to form a metal nitride film. Similarly, a negative voltage is applied to the cathode 16 and the glass substrate 26 is moved six times to form a second coating.

The heat-reflecting glass on which the first coating and, if necessary, the second coating have been formed in this way is then bent in a non-oxidizing atmosphere.

Although there are no particular limitations on the bending method, the bending process can be performed by heating, for example, using an electric furnace as shown in FIG.

The electric furnace shown in FIG. 4 is heated by a heater 30, and the temperature inside the furnace is adjusted from the temperature measured by a thermocouple 31 by a temperature coat roller 32.

Also, the gas is supplied to the valve 35 of the gas cylinder 33 or 34.
．． 36 is adjusted to a predetermined flow rate based on the value of a flow meter 37, and the gas is introduced into the furnace through a gas supply pipe 38.

To bend heat-reflective glass using such an electric furnace, heat the electric furnace to about 600 to 750°C, supply atmospheric gas into the furnace from the cylinders 33 and/or 34, and bend the heat-reflective glass 39. It is set on the bending table 40 and held for a predetermined time. Thereafter, the heat ray reflective glass 39 is taken out and left to cool.

In the present invention, the degree of bending varies depending on the size and thickness of the glass, the type and thickness of the coating, etc., but generally the radius of curvature is about 20 to 70 cm.

In the present invention, the non-oxidizing atmosphere in the furnace during such bending is, for example, N2. N2 and A
It is preferable to use an atmosphere consisting of one or more inert gases such as r.

[Function] Non-oxidizing heat-reflecting glass with a metal nitride absorption film: By bending it in an atmosphere, optical properties such as distortion during bending, changes in film color, and heat-reflection performance can be improved. This will improve the reduction in

Therefore, according to the present invention, it is possible to perform bending by heating without adversely affecting the quality of the heat-reflecting glass, so that a step of bending can be performed after film formation. Therefore, the film can be formed efficiently and inexpensively using a conventional film forming apparatus for flat plates, and the cost of the bent heat ray reflective glass can be reduced.

[Example] Examples and comparative examples will be described below.

Example 1 A bent heat-reflecting glass 1 shown in FIG. 1 was manufactured according to the method of the present invention.

First, using the sputtering equipment shown in Fig. 3, the following
The first and second coatings were formed in the steps of ~■.

(2) A Cr target 22 was attached to the lower surface of the cathode 15, and a cleaned glass substrate 26 was placed on the substrate holder 25 on the conveyor belt 21.

■ Open the barrier pull valve 12 and move the inside of the vacuum chamber 11 5X.
Reduce the pressure until it becomes 10-'Torr or less, and then connect the gas supply pipe 2.
Supply nitrogen from 0, close the barrier pull valve 12,
The pressure inside the vacuum chamber 11 was set to 2xto-''rorr.

■Next, by applying a negative voltage of 500μ to the cathode 15 and moving the glass substrate 26 under the cathode 15, a 500μ thick chromium nitride film, that is, the first film 3, is formed on the surface of the glass substrate 26. did.

Next, using the electric furnace shown in FIG. 4, bending was performed according to the following steps (1) to (2).

■ After heating the electric furnace to approximately 650℃, cylinder 3
Nitrogen gas was supplied from 3 and introduced into the furnace through a gas supply pipe 38.

(2) After the nitrogen gas is uniformly distributed in the furnace, the heat ray reflective glass 39 prepared above is set on the bending table 40.

■ Hold at approximately 630℃ for 3 minutes.

■ Take the glass 39 out of the electric furnace and let it cool down to a natural number.

The transmission spectrum of the obtained bent heat-reflecting glass (degree of bending: 2 curvature radius: 42 cm) is shown in FIG. Also,
Table 1 shows the visible light transmittance before and after bending. For comparison, the transmission spectrum of the sample before bending is also shown in FIG.

Comparative Example 1 A bent heat ray reflective glass was produced in the same manner as in Example 1 except that the bending process was performed in an air atmosphere.

The transmission spectrum of the obtained bent heat-reflecting glass is shown in FIG. Table 1 also shows the visible light transmittance before and after bending.

Example 2 In Example 1, Ti is attached as a target 23 on the lower surface of the cathode 16, and in step (2) of the film forming process, a negative voltage of 550 mm is applied to the cathode 16, and the glass substrate 26 is moved. Thus, a bent heat ray reflective glass 1 was manufactured in the same manner as in Example 1, except that a titanium nitride coating having a thickness of 800 mm was formed.

The transmission spectrum of the obtained bent heat-reflecting glass is shown in FIG. Table 1 also shows the visible light transmittance before and after bending. For comparison, the transmission spectrum of the sample before bending is also shown in FIG.

Comparative Example 2 A bent heat-reflecting glass was produced in the same manner as in Example 2, except that the bending process was performed in an air atmosphere.

The transmission spectrum of the obtained bent heat-reflecting glass is shown in FIG. Table 1 also shows the visible light transmittance before and after bending.

Example 3 In Example 1, Cr was attached to the lower surface of the cathode 15 as a target 22, and Ti was attached to the lower surface of the cathode 16 as a target 23, and following the film forming steps ① to ＠,
A bent heat ray reflective glass 1 having a titanium oxide coating as a second coating as shown in FIG. 2 was produced in the same manner as shown in FIG. 2, except that the film was formed through the steps (1) and (2) below.

■ Turn off the power of cathode 15 and reconnect to 5×10-”T.
After creating a vacuum below o r r, oxygen is introduced from the gas supply pipe 20, and the pressure inside the vacuum chamber 11 is reduced to 2X10-'T.
I made it so that it becomes orr.

■ Next, by applying a negative voltage of 450 V to the cathode 16 and moving the glass substrate 26 under the cathode 16, a titanium oxide film was formed as the second film 4 on the chromium nitride film 3 to a thickness of 60 mm. .

The transmission spectrum of the obtained bent heat-reflecting glass is shown in FIG. Table 1 also shows the visible light transmittance before and after bending. For comparison, the transmission spectrum of the sample before bending is also shown in FIG.

Comparative Example 3 A bent heat ray reflective glass was produced in the same manner as in Example 3 except that the bending process was performed in an air atmosphere.

The transmission spectrum of the obtained bent heat-reflecting glass is shown in FIG. Table 1 also shows the visible light transmittance before and after bending.

Example 4 A bent heat ray reflective glass 1 was manufactured in the same manner as in Example 3, except that Sn was attached as the target 23 to the lower surface of the cathode 16 and a tin oxide film was formed as the second film.

Table 1 shows the visible light transmittance of the obtained bent heat ray reflective glass before and after bending.

Comparative Example 4 A bent heat-reflecting glass was produced in the same manner as in Example 4, except that the bending process was performed in an air atmosphere.

Table 1 shows the visible light transmittance of the obtained bent heat ray reflective glass before and after bending.

Table 1 From Figures 5 to 7 and Table 1, it is clear that according to the method of the present invention, changes in visible light transmittance due to bending are small and good heat ray reflection performance is maintained. .

[Effects of the Invention] As detailed above, the method for manufacturing bent heat ray reflective glass of the present invention involves forming an absorbing film containing a metal nitride film on the surface of a glass substrate, and then bending the glass in a non-oxidizing atmosphere. It is characterized by the following: ■ Absorbing film can be formed using ordinary flat plate film forming equipment, equipment cost is low, control work is easy, and film can be formed in a short time. can.

■ Since the film is formed on flat glass, the possibility of film defects occurring is extremely low.

■ There is no distortion or change in color tone due to bending, and the deterioration of optical properties is extremely small.

It has excellent effects such as

Therefore, according to the present invention, it is possible to provide a high-performance bent heat ray reflective glass at low cost and high productivity.
The industrial utility of the present invention is extremely high.

[Brief explanation of drawings]

FIG. 1 and FIG. 2 are sectional views each showing an embodiment of the bent heat ray reflective glass manufactured by the present invention. FIG. 3 is a schematic diagram showing the configuration of a sputtering apparatus suitable for implementing the method of the present invention, and FIG. 4 is a schematic diagram showing the configuration of an electric furnace suitable for implementing the present invention. Fig. 5 is a graph showing the results of Example 1 and Comparative Example 1, Fig. 6 is a graph showing the results of Example 2 and Comparative Example 2, and Fig. 7 is a graph showing the results of Example 3 and Comparative Example 3. It is. DESCRIPTION OF SYMBOLS 1...Bent heat ray reflective glass, 2...Glass substrate, 3...Metal nitride coating, 4...Metal oxide coating. Agent Patent Attorney Tsuyoshi Shigeno Figure 3 Figure 4 Wavelength (nm) Wavelength (nm)

Claims (5)

[Claims] (1) A method for producing bent heat-reflective glass, which comprises forming an absorbing film containing a metal nitride film on the surface of a glass substrate, and then bending the glass in a non-oxidizing atmosphere. (2) The method according to claim 1, wherein the non-oxidizing atmosphere is an atmosphere consisting of one or more selected from the group consisting of N_2, Ar, and H_2. (3) The method according to claim 1 or 2, wherein the metal nitride is chromium nitride, titanium nitride, or titanium aluminum nitride. (4) The method according to any one of claims 1 to 3, wherein the absorbing film comprises a metal nitride film and a metal oxide film formed thereon. (5) The method according to any one of claims 1 to 4, wherein the metal oxide is titanium oxide or tin oxide.