JPS62197332A - Treatment of glass substrate stock - Google Patents

Abstract

PURPOSE:To improve the quality and reliability of a glass surface and to obtain a glass substrate stock suitable for a display device by subjecting the glass substrate stock to a heat treatment in an acidic gaseous atmosphere then rinsing the stock and further forming a metallic oxide film thereon. CONSTITUTION:The glass substrate stock is exposed in the acidic gaseous atmosphere and is heat-treated in a 300-530 deg.C, more particularly 400-500 deg.C range to inactivate the surface. The metallic oxide film is formed on the surface of the glass substrate stock after rinsing. For example, a soln. contg. a silanol, the oligomer there of or the precursor thereof is coated on the surface of the glass substrate stock and is subjected to a heat treatment to form a silicon film. The metallic oxide film may be an indium oxide film, tin oxide film, titanium oxide film, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for processing glass substrate materials. More specifically, the present invention relates to a method for treating a T-dyed glass substrate material to improve the quality and reliability of the display device.

Conventional technology Various methods are known for using glass substrates, but
In recent years, solar cells, electroluminescence,
It has also come to be used in electrochromic and fluorescent display tubes. In any case, the surface of the glass substrate must be clean before it is put into use. For example, in the case of glass for liquid crystal display devices, a transparent conductive film is patterned on each of two cleaned glass substrates. Display electrodes are formed between the electrodes, and a liquid crystal is sandwiched between these electrodes and electricity is applied to produce the desired display.

In the early days, materials such as polished borosilicate glass were often used for the glass substrates of liquid crystal display devices. With improvements in stabilizing coating technology, it is replacing soda lime glass. When using soda lime glass as it is as a display substrate,
Alkali metal components in the glass gradually seep out onto the glass surface, adversely affecting the liquid crystal, resulting in deterioration of the liquid crystal display function, decrease in resistance, increased power consumption, and display smearing, which shortens the life of the liquid crystal display element. It has the disadvantage that it is short. For this reason.

When soda lime glass is used as a substrate for a liquid crystal display device, a silica-based or similar coating is formed to stabilize the glass surface and prevent components in the glass from seeping out onto the surface. ing. Prior art examples of such examples are as follows.

(1) Japanese Unexamined Patent Publication No. 53-92813 discloses a method in which a solution of tetrasilicon oxide is applied onto a substrate and fired.

(2) Japanese Unexamined Patent Publication No. 53-82444 discloses a method in which a solution obtained by adding a poron ester solution to a silicon ester solution is applied onto a substrate and then fired.

(3) JP-A-57-2023 discloses a method in which a mixed solution of an organic titanium compound and an organic silicon compound is applied onto a substrate and fired.

(4) JP-A-55-135818 discloses a method of depositing -silicon oxide on a substrate and then oxidizing the silicon monoxide.

All of these methods involve providing some type of coating on the glass surface in order to stabilize the surface, and the coating is generally thin. Therefore, since these prior art techniques do not fundamentally modify the surface of the glass material, it is necessary to thicken the coating to form a coating using these methods. To do this, it takes a long time and the process has to be repeated many times, so the work efficiency is poor. In other words, conventional techniques are not sufficient methods to prevent the components from leaching out of the glass. isn't it.

In addition, in solar cells using glass substrates, α-
The 3T type is often used, but particularly effective as a low-cost transparent electrode is a method in which a tin compound is sprayed onto preheated glass to coat it with 5N02.

However, this method has a problem in that the alkali metal in the glass diffuses into the 5n02 coating and obstructs the inductivity of SnO2, making it impossible to obtain a low resistance value, resulting in a decrease in power generation efficiency.

Problems to be Solved by the Invention Under these circumstances, an object of the present invention is to provide a treatment method for treating contaminated glass substrate materials to improve the quality and reliability of the glass surface. It is in.

Means for Solving the Problems As a result of extensive research, the present inventors have developed a glass substrate characterized in that the glass substrate material is heat treated in an acidic gas atmosphere and then washed with water, after which a metal oxide film is further formed. The inventors have discovered that the above object can be achieved by a method of processing materials, and have completed the present invention based on this knowledge.

The configuration of the present invention will be explained in detail below.

(Type of glass) Examples of the glass in the present invention include borosilicate glass and soda lime glass, but are not limited thereto.

(Ripe treatment) The heat treatment in an acidic gas atmosphere of the present invention refers to sulfur, sulfur dioxide, sulfuric acid, and ammonium sulfate.

Sulfur compounds such as ammonium hydrogen sulfate, beloquine-ammonium sulfate, ammonium beloxon disulfate, double salts of ammonium sulfate and ammonium hydrogen sulfate, and double salts of sulfuric acid and ammonium hydrogen sulfate, chlorine compounds such as hydrogen 11de, aluminum chloride, ammonium chloride, dioxide In an atmosphere of acidic gas generated by heating at least one compound selected from compounds that release active groups when heated, such as carbon, magnesium charcoal, etc.
The process involves exposing the glass substrate material to be treated and inactivating the glass surface.

The heating temperature at this time is 300-530℃, especially 400-530℃
It is preferable to conduct the heating in a temperature range of 500°C. A high heating temperature is better, but if the heating temperature is too high, the phenomenon of warping will occur in the glass substrate material, so it is not preferable. Since distortion occurs, it is necessary to control the heating temperature so that it does not exceed this temperature.

When performing heat treatment, the combination of the type and quality of the glass to be treated, the acidic gas source used, the heating temperature, and the treatment time can be selected as appropriate.These conditions can be determined in advance by conducting a simple preliminary experiment. This is convenient because the settings can be made by

(Formation of Metal Oxide Film) Next, a metal oxide film is applied to the glass substrate material which has been heat treated in an acidic gas atmosphere and washed with water. Among metal oxide films, silicon-based films are particularly effective because they can be used in a wide range of ways. JP-A-53-82444, JP-A-57-202
No. 3, Japanese Patent Application Laid-open No. 55-135818, etc., so it can be applied according to these methods.
Preferably, a simple method is to apply a solution containing silanol, its oligomers, or their precursors onto a substrate and heat-treat the solution to obtain a silicon-based film. Other methods include chemical vapor deposition (CVD);
There are methods such as a method in which silicon oxide is deposited and then oxidized, and a sputtering method. All of these are known techniques.

As a specific example, a method of applying a solution is shown. A coating liquid is prepared by adjusting the viscosity of a composition consisting of tetrahydroxy silicone, a carboxylic acid ester, and alcohol with an organic solvent as necessary. A silicon-based coating can be obtained by applying the thus obtained coating liquid onto a substrate material by a method such as a dipping method or a spraying method and drying it. If you want to quickly obtain a silicon-based coating, it is best to heat it appropriately.The heating temperature at that time is preferably 100°C or higher.If there is a concern about thermal deformation of the glass substrate material, which is the object to be treated, it is recommended to heat it appropriately. The upper limit value of the heating temperature may be determined in consideration of the temperature.

Regarding other metal oxides, films can be formed by replacing the silicon compound with other metal atoms in the above-mentioned method for forming a silicon-based film, but there are other methods, such as a) When forming an indium oxide film, a solution consisting of a reaction product of indium nitrate and β-diketone or a mixture of indium nitrate, β-diketone, and an organic solvent; b) When forming a tin oxide film C) When forming a titanium oxide film, a solution of tetraalkoxytin dissolved in one of the group consisting of alcohols, esters, ketones and ethers; A mixed solution of the product reacted with alcohol, d) when forming an aluminum oxide film.

A reaction mixture solution obtained by reacting aluminum alcoholade with fatty acid or fatty acid anhydride and alcohol in the presence of a reaction accelerator; e) When forming a cerium oxide film, cerium nitrate and butyral resin are mixed with methanol and ethanol. , methyl acetate, ethylene glycol monoethyl ether, etc.

f) When forming a zirconium oxide film.

g) A reaction product mixture solution obtained by reacting zirconium alcoholade and fatty acid anhydride in the presence of nitric acid in an alcoholic solvent; Reaction product mixed solution.

h) In the case of forming a tungsten oxide film, a mixed solution is prepared by dissolving phosphotungstic acid in a7ton, and adding thereto an ethanol solution of polyvinyl butyral and ethylene glycol monomethyl ether.

i) In the case of forming a molybdenum oxide film, a mixed solution is prepared by dissolving phosphomolybdic acid in a7ton, and adding an ethanol solution of polyvinyl butyral and ethylene glycol monomethyl ether.

j) When forming a zinc oxide film, zinc acetylacetonate is mixed with acetic acid ethyl ester, methanol or β
- A solution prepared by dissolving and mixing a ketone resin in a diketone as a solvent.

k) butanol solution of iron naphthenate when forming an iron shell in acid 1;

By coating the solution on a glass substrate and baking with Z7 heat, the metal compound in the solution is decomposed and changed into a metal oxide, so the metal compound may be selected and used with reference to these specific examples.

These gold Ji! When choosing an oxide film.

For example, aluminum oxide is used for fluorescent tubes, magnesium oxide is used for plasma display panels, titanium or zirconium oxide is used for adjusting the refractive index, and coloring is used for adjusting the refractive index. When U is used, iron oxide is effective.

(Preferred Embodiment) According to a preferred embodiment of the method of the present invention, first, a glass substrate material such as soda lime glass is exposed to the above-described acidic gas atmosphere to inactivate the surface of the glass substrate material. Through this treatment, the sodium and potassium ions in the glass substrate material, especially in the surface layer, are chemically changed into sulfur salts, carbonates, etc. due to the action of acidic gas, and become water-soluble. The above-mentioned sodium ions and potassium ions are removed from the glass to make it porous, but as a result, the concentration of active ions on the glass surface decreases and the glass surface becomes inactive.

EXAMPLES Next, the method of the present invention will be explained in more detail with reference to Examples.

Example 1 A batch furnace with contents 11401 was kept at 450°C, and 1
, IX 200 x 20 Omm size soda lime glass plates were arranged vertically at 10 mm intervals, each treatment agent shown in Table 1 was added, heat treated at 450° C. for 30 minutes, and then cooled to room temperature over 30 minutes.

Next, the glass plate was washed in the order of detergent solution, tap water, and pure water, and immersed in pure water maintained at 95°C for 24 hours.The concentration of sodium atoms leached from the glass was measured by atomic absorption spectrophotometry. The quantitative results are also shown in Table 1.

Table 1 (Part 1) Table 1 (Part 2) Table 1 (Part 3) Table 1 (Part 4) Table 1 (Part 5) From these results, it is clear that the heat treatment in an acidic gas atmosphere according to the present invention It can be understood that the glass surface is made inert.

Table 2 shows the concentration of sodium atoms exuded from the glass by using ammonium sulfate as another treatment agent and varying the treatment temperature.

Table 2 (Part 1) Table 2 (Part 2) Table 2 (Part 3) These results show that sodium ion leaching in the glass substrate can be prevented by heat treating the glass substrate in an acidic gas atmosphere.

Separately from the above, a batch furnace with contents A401 was kept at 450°C, soda lime glass plates of 1 x 200 x 200 mm were lined up at 10 mm intervals, 10 g of ammonium hydrogen sulfate was added as a processing agent, and heated to 450°C for 30 minutes.
After heating for 30 minutes, it was cooled to room temperature.
Next, when the glass plate was washed with an aqueous detergent solution, tap water, and pure water in that order, a white film was deposited on the entire surface of the glass plate. After cleaning the glass plate using an ultrasonic cleaner, the glass was treated with a coating solution made of tetrahydroxysilane (a product of Tokyo Ohka Kogyo Co., Ltd., trade name: rOcDJ). i, o on the board
Coat it to a thickness of oo angstroms and heat it at 500℃ for 3
Firing was performed for 0 minutes. When a transparent conductor of tin oxide (IV2) was formed on this layer using an atmospheric pressure CVD device, the film thickness was 350 angstroms and the resistance value was 760 Ω1.
A good coating of 0 was obtained. On the other hand, the resistance value of the untreated glass plate was 1520 Ω/hole, and a liquid crystal display element using this glass plate generated noise. In addition, a sodium ion leaching test was conducted as described above, and when immersed in pure water maintained at 95°C for one week, the sodium atomic concentration was 0.005 #Lg/crn', indicating that a silicon-based coating was further provided. The effect was significant.

Thus, it can be seen that the method of the present invention not only deactivates the surface of the glass substrate but also has the effect of lowering the resistance value.

Usage Example Using the glass substrate provided with the transparent conductive film obtained in Example 1, an FE-TN type liquid crystal display element was created, and display unevenness was observed over 300 hours at a temperature of 85°C and a humidity of 95%. When we investigated whether or not this occurred, we found that there was no smearing of the displayed characters, no abnormalities in the electrical characteristics, and a slight increase in power consumption.

Comparative Example On the other hand, using a glass substrate treated in the same manner as in Example 1 except that the heat treatment in the acidic gas atmosphere in Example 1 was omitted, a liquid crystal display element similar to that in the usage example was used to prevent display unevenness. When we investigated the presence of the problem, we found that the displayed characters were bleeding after 250 hours.

Example 3 In the same manner as in Example 1, it was coated on soda lime glass to a thickness of 120 nm using OCD manufactured by Tokyo Ohka Kogyo Co., Ltd., dried at 130°C for 15 minutes, and then dried on a conveyor set at 480°C. It was placed in a furnace, sprayed with the following tin compound solution, kept at the same temperature for 10 minutes, and then taken out.

5nC1a *5H20100g Ethyl alcohol 50m water exchange
50m sentence HC sentence
10m sentence sbc sentence 3 0.8g The sheet resistance value of the glass substrate treated in this way is 48Ω/mouth,
It! 2 thickness was 310 nm.

By the way, borosilicate glass (#705 manufactured by Corning)
The sheet resistance values of 9) and untreated soda lime glass plates to which tin oxide was similarly applied were 85Ω/hole and 270Ω/hole, respectively. In addition, regarding the untreated board, the surface was particularly cloudy.
Next, regarding this treated substrate, glass/ZnO2/α-
When an S i (p −1-n) /A main electrode amorphous solar cell was produced, its energy conversion efficiency was 6.2%. From this result, the treatment method of the present invention is advantageous because the power loss due to the resistance of the electrode is extremely small.

Effects of the Invention According to the method of the present invention, it is possible to prevent the glass components from seeping out from the glass substrate, and the surface of the glass substrate is covered with a film, which prevents the surface of the glass substrate from becoming rough. When used for display waves,
A highly reliable display device can be provided.

Claims (1)

[Claims] A method for processing a glass substrate material, which comprises heat-treating the glass substrate material in an acidic gas atmosphere, washing it with water, and then further forming a metal oxide film.