JPS6125133B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a panel glass constituting a cell in a liquid crystal display panel.

The purpose of the present invention is to surface-treat soda glass, etc., which has poor chemical durability, to improve its chemical durability to the same level as that of Pyrex glass, or even more so, to create a liquid crystal display panel made of soda glass, etc. This is aimed at reducing costs.

A conventional liquid crystal display panel has a structure as shown in FIG. Transparent electrodes are formed inside the upper and lower panel glasses, and in order to orient the liquid crystal, alignment treatments such as wrapping and oblique vapor deposition are applied to the upper and lower panel glasses so that the molecular axes of the liquid crystal are twisted. Align them, insert spacers to maintain even spacing, and secure with adhesive. Liquid crystal is sealed in this cell and it becomes a liquid crystal display panel. Generally, HIREX, which has strong chemical durability, is widely used as the material for the upper and lower panel glass. However, it has the drawback of being expensive and not economical.

Therefore, it would be better to use inexpensive soda glass, but the life of the display panel will be significantly shortened due to the leaching of alkali metals and the like contained in the soda glass. Therefore, it is impossible to use soda glass directly in liquid crystal cells, and it is necessary to perform appropriate surface treatment to improve chemical durability.

Conventional surface treatment methods for soda glass include sputter deposition.
There is a method to form Sio ₂ film. However, this method is not suitable for mass production because continuous film formation is impossible and there is a risk of trouble occurring in the sputter deposition equipment. There is also a method for surface treatment of soda glass using a commercially available Sio ₂ film forming agent. In this method, the treatment agent is a liquid, so it is applied by dipping the glass and rotating it, then drying and baking to coat the surface of the soda glass with Sio ₂ .
It forms a film. Although this method allows sufficient mass production, the selling price of the processing agent is high and it is not economical. Therefore, treated soda glass becomes more expensive than pyrex, and there is no advantage to using soda glass. In addition, silicon hydrides (collectively called silanes) are used to
There is Sio ₂ film formation due to CVD treatment. However, this method cannot form a film on both sides, and warpage occurs on small panel glass such as liquid crystal panels for watches, making it unapplicable.

The present invention aims to overcome the above-mentioned conventional drawbacks, and the present method uses an alkoxysilicate as a main ingredient, an alcohol (for example, methyl alcohol, ethyl alcohol, propanol, n-butyl alcohol, isopropyl alcohol) and an acid ( (e.g. acetic acid, hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, butyric acid)
Alternatively, use a treatment agent dissolved in a mixed solvent of water. As a treatment method, first, the soda glass is coated with a spinner method, a spraying method, a dipping method, a brush coating method, or the like. Next, dry with alcohol at a suitable temperature in the range of 100-200°C. This condition allows the final treatment film thickness to be controlled.

Furthermore, the temperature is 500℃, which is just before the softening point of soda glass.
Bake for 2 to 3 hours. By this firing, sufficient mechanical film strength can be obtained. However, with a treatment agent containing only alkoxysilicate, the film obtained is almost always a silica-based film, and a complete continuous layer of silica-based glass cannot be obtained by firing at 500°C, resulting in a lack of chemical durability. Since the firing temperature cannot be raised above 500℃ due to the softening point of soda glass, there is an urgent need to consider a processing solution that can form a film with the same chemical durability as Pyrex when fired at 500℃. It became.

Therefore, in the treatment solvent of alcohol and acid for the alkoxysilicate described above, organic metal compounds such as organic boron compounds, organic aluminum compounds, organic lead compounds, organic titanium compounds, organic phosphorus compounds, etc.
Or the metals mentioned above (aluminum, lead, titanium,
Zinc), inorganic acid salts such as hydrochlorides, nitrates, and sulfates of calcium, phosphorus, barium, potassium, and sodium, or organic acid salts of the above substances such as phosphoric acid and acetic acid, alone or in appropriate proportions. Several substances are adjusted in the range of 0.1-30%. This solvent is applied by a spinner spraying method, dipping method, brush coating method, etc., and dried at a temperature of 100 to 300°C for an appropriate period of 10 to 60 minutes. Furthermore, 2 in the range of 400℃~500℃
Bake for ~3 hours. The resulting coating was able to significantly increase its chemical durability.

According to the present invention, the film thickness can be freely controlled from 500 Å to 2000 Å, and various types of glass films can be formed by blending various compounds in appropriate proportions, and chemical durability is comparable to that of Pyrex. The same or better effect was obtained. Further, the film forming operation is simple and can be applied economically, and the present invention can be similarly applied as a surface protective film or a surface stabilizing film in the future. The above thin film
If it is less than 500 Å, the alkali metal elution cannot be prevented, and if it exceeds 2000 Å, cracks are likely to occur.

Next, the present invention will be explained by examples.

Example 1 Tetramethoxysilane: Trimethoxyphorone:
Adjust the ratio of trimethoxyaluminum: sodium acetate, lead acetate = 68.4%: 19.5%: 4.5%: 3.8%: 3.8%, dilute this mixed solvent with methyl alcohol acetic acid to about 10% and use Sio ₂ film forming agent. shall be. Soda glass is immersed in this solvent and spun off with a spinner to obtain a uniform coating. After that, dry thoroughly with alcohol in a constant temperature bath at 150°C for about 30 minutes, and then bake at 500°C for 2 hours.

In the formed film, each metal oxide was uniformly distributed in Sio ₂ , and the chemical durability was almost the same as, or even better than, Pyrex glass. FIG. 2 shows a cross-sectional view of a liquid crystal display panel constructed from panel glass subjected to this treatment.

1... Panel glass, 2... Transparent electrode, 3... Liquid crystal,
4...Spacer, 5...Surface treatment film.

As described above, according to the present invention, glass with weak chemical durability such as soda glass can be surface-treated with extremely simple operations and economically, and in the future it will be possible to use an economical glass surface treatment method for liquid crystal display panels. It will be applied to a wide range of other areas as well.

[Brief explanation of the drawing]

FIG. 1 shows a conventional liquid crystal panel. FIG. 2 shows a liquid crystal panel according to the invention.

Claims (1)

[Claims] 1 The panel glass constituting the cell of a liquid crystal display panel that uses liquid crystal molecules as light pulp to display images controlled by an electric field effect or controlled by an electric current effect, is prepared by using an organic silicon compound as a main component in a solvent. , boron, aluminum, sodium, barium, magnesium, fluorine, lead, titanium, zinc, potassium, or inorganic acid salts of the above substances such as hydrochloride, nitrate, sulfate, or formate of the above substances, acetic acid. A method for manufacturing a liquid crystal panel in which a thin film of 500 to 2000 Å is formed by coating an organic acid salt such as a salt alone or with a treatment solution containing several of the above substances and then firing at a temperature below the softening point of the panel glass. .