JP2792276B2 - Conductive glass - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductive glass, and more particularly to a conductive glass having high strength and high wear resistance.

[0002]

2. Description of the Related Art In recent years, conductive glass has been used in various displays.
・ Electrode such as thin film solar cell, transparent touch sensor,
Applications have been made in various fields such as transparent antistatic bodies and transparent electromagnetic wave shields. Conductive glass is obtained exclusively by coating a transparent conductive coating material on the glass. As this kind of material, an oxide material exhibiting a semimetallic behavior is preferably used, and typical examples thereof include tin oxide, indium tin oxide (hereinafter referred to as ITO), zinc oxide, and cadmium tin oxide. No.

[0003] In some applications, since the conductive glass is usually exposed to the space used, high abrasion resistance and chemical resistance (acid resistance and alkali resistance) are required. Further, in order to ensure safety, the glass itself may be required to have a significantly higher strength than a normal sheet glass. In order to obtain a glass of high strength, usually, a glass heated above the softening point is rapidly cooled from the surface to obtain a compressive stress by means of air-cooling or immersion of the glass in a molten salt containing potassium ions. Then, a means called chemical strengthening for exchanging with sodium ions in the glass and obtaining a surface compressive stress based on the difference in the size of the ions is preferred. In any case, in the step of increasing the strength of the glass, the glass is exposed to a high temperature of about 400 ° C. to 600 ° C.

[0004]

However, it has been difficult to simultaneously satisfy the electrical characteristics of the conductive glass, the mechanical strength of the film, and the glass strength. For example, an ITO film, which is a typical transparent conductive film, exhibits excellent electrical characteristics. However, the abrasion resistance and chemical resistance of the film are weak, and the film is strengthened by air cooling or chemical strengthening to obtain the strength of the glass. In this case, there is a problem that electric characteristics are deteriorated or a film is lost.

On the other hand, the wear resistance of the tin oxide film is superior to that of the ITO film. However, if the strength of the glass is increased by air-cooling, the film often cracks or the glass is significantly deformed due to a rapid temperature change in the process. Therefore, strict temperature control is required in this air cooling strengthening treatment, which impairs productivity.

[0006] Further, it is conceivable to apply a transparent conductive film to glass that has been previously subjected to air cooling and chemical strengthening treatment. In this case, if the film forming treatment temperature is high, the surface compressive stress layer is formed by the movement and diffusion of atoms. Will disappear.

Therefore, as a means for producing a conductive glass having a sufficient glass strength, a method (for example, vacuum evaporation or sputtering) capable of performing a film forming treatment at a low temperature after a strengthening treatment is applied. However, this type of equipment requires a vacuum and the cost of coating is unavoidably high.

An object of the present invention is to solve the above-mentioned conventional problems and to provide a conductive glass having high strength and high wear resistance and a method for producing the same.

[0009]

The conductive glass according to claim 1 is a conductive glass in which a coating containing tin oxide containing potassium as a main component is applied on a glass plate. The thickness of the coating to be formed is in the range of 1 to 100 nm, the concentration of potassium is 0.1 to 10.0% by weight, and the glass surface stress is 20 to 100 kg / mm ² .

According to the present invention, a tin oxide film is formed on a glass plate by one to one.
After forming 100 nm , the glass plate is brought into contact with molten potassium nitrate to contain potassium in the glass plate and the coating, and the potassium concentration in the coating is 0.1 to 10% by weight.
And a glass surface compressive stress of 20 to 100 kg / mm ²
It is manufactured by:

The coating of the present invention containing tin oxide as a main component can be formed by a thermal decomposition method .

[0012]

According to the present invention, if a tin oxide film having an appropriate thickness is formed and then a chemical strengthening method is employed, the glass can be given strength without significantly impairing the electrical characteristics of the film, and By including potassium in the tin oxide film, the wear resistance of the film can be improved.

As a means for forming a tin oxide film, a vacuum evaporation method,
There are various methods such as a sputtering method, a spray method, a CVD method, and a dipping method. Among them, a so-called thermal decomposition method such as a spray-CVD method is advantageous from the viewpoint of cost and productivity. In the thermal decomposition method, a tin compound having thermal decomposability is a main raw material, specifically, SnCl ₄ , (C _n H _{2n + 1} ) ₄ Sn
(However, n = 1 to 4), C ₄ H ₉ SnCl ₃ , (CH ₃ )
_It is general to use ₂ SnCl ₂ , (C ₄ H ₉ ) ₂ Sn (OCOCH ₃ ) _{2 and the} like. Fluorine is often added to the film in order to improve the electrical characteristics, and the materials include HF, CCl ₂ F ₂ , CHClF ₂ , and CH ₃ CH.
F ₂ , CF ₃ Br, CF ₃ COOH, NH ₄ F and the like are known. A vapor is obtained by bringing the vapors of these raw materials into contact with heated glass together with an oxidizing gas such as oxygen to obtain a film, or by dissolving in an organic solvent such as alcohol, benzene or toluene and spraying the heated glass to form a film. Get.

The film thickness is preferably thicker from the viewpoint of lowering the electric resistance. However, if it is too thick, transparency is impaired due to light absorption of the film, and ion exchange in the chemical strengthening step becomes difficult. A practical film thickness range is 1 to 100 nm, preferably 5 to 50 nm.

The chemical strengthening is performed by melting a salt containing potassium such as potassium nitrate and immersing the glass for a predetermined time.

The electrical resistance of the conductive glass thus obtained is slightly increased as compared with that before the chemical strengthening treatment, but is not a serious obstacle in practical use.

In order to examine the abrasion resistance performance of this film, the change in electrical resistance was measured using a reciprocating sliding tester. Eventually, the resistance value was reversed and the one that had been chemically strengthened had high durability. Although the detailed cause is unknown, it can be considered that potassium which is almost uniformly distributed in the tin oxide film plays a role as shown in FIG.

The concentration of potassium in the tin oxide film entering in the chemical strengthening step is preferably 0.1 to 10% by weight. If the potassium concentration is lower than 0.1% by weight, the effect of improving the wear resistance performance is diminished. On the other hand, when the content is higher than 10% by weight, adverse effects such as an increase in electric resistance of the film appear.

When the strength of the glass was evaluated by a glass surface stress measuring instrument using a photoelastic method, a glass with a conductive film having a strength comparable to that of a sample without a tin oxide film was obtained.
It is was found. Regarding the validity of chemical strengthening, we looked at the depth concentration profile of potassium on the glass surface,
As shown in FIG. 1, the same profile was obtained regardless of the presence or absence of the film.

The value of the glass surface stress by the chemical strengthening treatment is desirably ^{20 to} 100 kg / mm ² . In surface stress value 100 kg / mm ² or more, fracture stress of the glass Ki close not a (about 200~300kg / mm ^2), a possibility occurs unfavorably becomes self-destructive stress unstable. Further, when the surface stress value is 20 kg / mm ² or less, it does not substantially lead to an increase in the strength of the glass, and the difference from the surface stress on the non-film surface (normally chemically strengthened) increases, thereby causing adverse effects such as warpage. Will occur.

[0021]

Example 1 A 100 mm square float plate glass (5 mm
Thickness) was prepared and used as a substrate. This was coated with a tin oxide film by the following method.

It was produced by a CVD method using a mixed gas consisting of monobutyltin trichloride and water vapor, oxygen gas, 1,1-difluoroethane gas and nitrogen gas. The heating temperature of the glass was 540 ° C. By appropriately changing the flow rate of the tin raw material, three types of films having different thicknesses were obtained. The electrical resistance value (resistance between two terminals at 1 cm intervals) and the C light transmittance of this conductive glass are as described in Table 1. (Below)

Next, these three kinds of conductive glasses were immersed in potassium nitrate (temperature: 470 ° C.) in a molten state for 4.5 hours, pulled up, and then gradually cooled. For comparison, float glass (5 mm thick) without a tin oxide film was immersed at the same time. Thereafter, the film was washed with water, and the electric resistance value and the C light transmittance were measured.

A small piece of 50 × 70 mm was cut out from the sample, and a change in electric resistance was measured using a reciprocating sliding tester to examine the wear resistance of the film. The result is shown in FIG.

Next, a small piece of 30 mm square was cut out from the glass sample, and the surface stress of the glass subjected to the tempering treatment was measured by a glass surface stress measuring device manufactured by Toshiba Glass. These results are also shown in Table 1.

An EPMA (Electron Beam Microanalyzer) is used to confirm whether or not ion exchange is being performed.
, The concentration profile of potassium ions in the depth direction was observed from the glass film surface. The results are shown in FIG.

Further, in order to grasp the influence of the chemical strengthening process on the tin oxide film, Sn, K,
FIG. 2 shows the results of observing the concentration profiles of Na, Si, and atoms in the depth direction.

Example 2 A 100 mm square float glass plate (5 mm
Thickness) was prepared and used as a substrate. This was coated with a tin oxide film by the following method.

9. Dibutyltin diacetate, trifluoroacetate and isopropanol are mixed in the following ratio, and this solution is sprayed on glass heated to 600 ° C. to form a tin oxide film on dibutyltin diacetate. 0 g trifluoroacetate 1.6 g 200 g of isopropanol was prepared. By changing the spray time, three types of films having different film thicknesses were obtained. The electrical resistance (resistance between two terminals at 1 cm intervals) and the C light transmittance of this conductive glass are as shown in Table 2.

Next, the four types of conductive glasses were immersed in potassium nitrate (temperature: 470 ° C.) in a molten state for 4.5 hours, then pulled up, and then gradually cooled. For comparison, float glass (5 mm thick) without a tin oxide film was immersed at the same time. Thereafter, the film was washed with water, and the electric resistance value and the C light transmittance were measured.

Next, a small piece of 30 mm square was cut out from the glass sample, and the surface stress of the glass subjected to the tempering treatment was measured by a glass surface stress measuring device manufactured by Toshiba Glass. These results are also shown in Table 2.

A small piece of 50 × 70 mm was cut out from the remaining sample, and the change in electric resistance was measured using a reciprocating sliding tester to examine the wear resistance of the film. The results were the same as in Example 1.

[0033]

As described above, according to the present invention, the tin oxide film
Sodium ions in the glass through the potassium ion
When a compressive stress layer is formed on the glass surface.
Sometimes the tin oxide film contains potassium
It was found that a glass plate having high mechanical strength was obtained, and at the same time, the abrasion resistance of the film was significantly increased.

[Brief description of the drawings]

FIG. 1 is a depth profile of Na and K ions of a glass provided with a tin oxide film after a chemical strengthening treatment in an example of the present invention.

FIG. 2 is a graph showing Sn, in a tin oxide film-coated glass according to an embodiment of the present invention, in a film after a chemical strengthening treatment, and on a glass surface.
It is a depth direction profile of Si, Na, and K.

FIG. 3 shows the results of abrasion resistance test of a tin oxide film-coated glass according to an example of the present invention before and after a chemical strengthening treatment.

──────────────────────────────────────────────────の Continuation of the front page (56) References JP-A-61-227946 (JP, A) JP-B-53-38727 (JP, B2) JP-B-54-8492 (JP, B2) JP-B-63 2906 (JP, B2) (58) Fields investigated (Int. Cl. ⁶ , DB name) C03C 15/00-23/00

Claims (1)

(57) [Claims] 1. A glass plate which has been subjected to a chemical strengthening treatment for replacing sodium ions in a glass with potassium ions,
Coated with tin oxide containing potassium as the main component
A transparent antistatic body , wherein the chemical strengthening treatment is performed after the coating of the coating, and the thickness of the coating containing tin oxide as a main component is 1 to 100 n.
m, and the potassium concentration in the tin oxide-based coating is
0.1 to 10.0% by weight; the surface stress of the glass is 20 to 100 kg / cm ² ; and the resistance between two terminals of the coating containing tin oxide as a main component at intervals of 1 cm is 5.05 × 10 5. Less than ⁷ Ω
Transparent antistatic body .