JPH0986969A - Reclamation of glass base plate for color filter having resin-made light-shading layer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process to reclaim glass base plate from which all thin films are removed from color filters having the deficient resin made light- shading layer. SOLUTION: A defective color filter having the resin made light-shading layer is reclaimed through the following steps: the step (A) wherein the color filter is soaked in a hydrochloric acid aqueous solution, the step (B) wherein the color filter undergone the step (A) is dipped in an amino alcohol or a solution of an amino alcohol in a polar solvent and the step (C) wherein the color filter undergone the steps (A) and (B) is brush-scrubbed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for recycling a glass substrate for a color filter having a resin light shielding layer. More specifically, the present invention provides a workstation,
The present invention relates to a method for recycling a glass substrate from a defective color filter having a resin light-shielding layer used in various color liquid crystal display devices such as displays for personal computers and navigation systems and liquid crystal televisions.

[0002]

2. Description of the Related Art In a pigment dispersion method color filter using a color resist and a resin black resist as a light-shielding layer, a black resist is first patterned on a glass substrate, and red, green and blue color resists are sequentially patterned and baked. After that, it is formed by forming an overcoat layer if necessary and finally forming an indium tin oxide (ITO) layer.

In recent years, a liquid crystal display device is manufactured by stacking glass substrates on which several color filters are formed and glass substrates on which the same number of pixel electrode patterns are formed, through a liquid crystal, from the viewpoint of improving productivity. It became so. Therefore, for example, in the case of four chamfers, the defect rate of the color filter becomes four times as large as that in the previous one chamfering, and the yield is significantly lowered, and a large number of defective color filters can be formed.

[0004]

The defective color filter generated as described above could not be reused by the conventional technique. Therefore, a large amount of expensive glass substrates are discarded as defective color filters, which is a problem from the viewpoint of environmental hygiene and economical efficiency. That is, an object of the present invention is to provide a method for recycling a glass substrate from a defective color filter.

[0005]

In order to solve the above-mentioned problems, the inventors of the present invention have made earnest studies on a method of recycling a glass substrate from a large number of defective color filters, and as a result, arrived at the present invention.

That is, the present invention is characterized in that a defective color filter having a resin light-shielding layer is treated by a method including the following steps (A) to (C). The present invention relates to a method for recycling a glass substrate for a filter. (A) Step of immersing the color filter in an acidic aqueous hydrochloric acid solution (B) Step of immersing the color filter treated in (A) in amino alcohol or a mixed solution of amino alcohol and a polar solvent (C) In the above (B) Brush scrubbing the treated color filter

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Defective products of the color filter used in the present invention include a resin light-shielding layer and red on a glass substrate.
A color filter created by forming pixels consisting of green and blue color resists, in which defects such as defects in the pixels and the light-shielding layer are seen, in which separation between pixels is poor and color bleeding is seen, Insufficient flatness due to poor film formation of the coat layer and interference fringes visible by light, light-shielding film and red,
Defective products such as those in which green and blue are misaligned, those in which ITO does not satisfy the resistance value in a predetermined range, and those in which dust is mixed in the manufacturing process. However, since the glass substrate itself does not include those having scratches or defects, the cause of the defect is investigated and the cause of the glass substrate itself is excluded.

Generally, the uppermost layer of the color filter is IT.
Since the O film is formed, the defective color filter is immersed in a hydrochloric acid acidic solution to remove the ITO layer.

The acidic aqueous hydrochloric acid solution is simply an aqueous solution in which hydrochloric acid is dissolved, an aqueous solution in which hydrochloric acid and other acids such as nitric acid and perchloric acid are dissolved in water, and an oxidizing agent such as hydrochloric acid and ferric chloride in water. It means a liquid used for etching ITO such as a dissolved aqueous solution.

The temperature at the time of immersion is in the range of 0 ° C. to the boiling point of the aqueous solution used. However, if the temperature is too low, the immersion time becomes too long, and if the temperature is too high, a large amount of hydrochloric acid vapor is generated, which is not preferable for safety and hygiene. Immersion at room temperature to 50 ° C. is preferable. The immersion time may be set so that the ITO film is completely removed depending on the concentration of the solute of the hydrochloric acid acidic aqueous solution and the immersion temperature. Under normal conditions, several minutes to several hours are common.

In the defective color filter from which the ITO film has been removed as described above, the color resist layer and the resin light shielding layer (and the overcoat layer) are then removed. Color resist and resin shading layer (and overcoat layer)
Since is generally an acrylic resin, it can be removed with amino alcohol or a mixed solution of amino alcohol and a polar solvent if it is just a film-formed product. However, when it is used as a color filter, it is generally subjected to heat treatment after film formation.Therefore, after soaking in aminoalcohol or a mixed solution of aminoalcohol and a polar solvent, brush scrubbing is performed to obtain a color resist. The layer and the light shielding layer (and the overcoat layer) are removed. In addition, you may wash with water before this immersion. By washing with water, it is more preferable that the acidic aqueous hydrochloric acid solution is prevented from mixing into the amino alcohol or the mixed solution, and the life of the amino alcohol or the mixed solution is extended.

The amino alcohols used are monoethanolamine, 1-amino-2-propanol and 2-
Amino-1-propanol, 2-amino-1-butanol, 4-amino-1-butanol and the like can be mentioned. These may be used alone or in combination of two or more. Among them, monoethanolamine is particularly preferable from the industrial viewpoint in consideration of the removal performance of the color resist and the resin light shielding layer (and the overcoat layer) and the price.

Specific examples of the polar solvent in the mixed liquid used include water, N, N-dimethylformamide, dimethyl sulfoxide, N-methyl-2-pyrrolidone, γ-butyrolactone, diethylene glycol monoalkyl ether,
Examples thereof include 3-methyl-3-methoxyethanol, butyrocellosolve, N, N-dimethylacetamide, hexamethylenephosphoramide and propylene carbonate. One kind of these polar solvents may be mixed with the amino alcohol, or two or more kinds of polar solvents may be used.

The mixing ratio of amino alcohol and polar solvent is 10: 0 to 1: 9 by volume ratio of amino alcohol: polar solvent.
The range may be selected according to the type of color resist (and overcoat) to be removed, but is generally in the range of 10: 0 to 1: 4.

The immersion temperature may be in the range of room temperature to the boiling point of the amino alcohol or the mixed solution, but at around room temperature, the penetration of the amino alcohol or the mixed solution into the color resist and the light shielding layer (and the overcoat layer) is slow and the immersion time is long. Is longer, a large amount of solvent vapor is generated near the boiling point, the condenser is large, and the equipment cost increases.
~ 90 ° C is preferred. The immersion time varies depending on the type of amino alcohol or mixed liquid medium used, the types of color resist and light-shielding layer (and overcoat) to be removed, the immersion temperature and the following brush scrub conditions. It may be selected so that the color resist and the light shielding layer (and the overcoat) can be completely removed by immersion in alcohol or a mixed solution and brush scrubbing.

In the brush scrub, the liquid crystal display (LC
D), a large-scale integrated circuit device (LSI), and a brush-equipped washing machine used in the color filter manufacturing process can be used. Since the substrate is glass,
The bristles made of resin such as nylon, polypropylene or acrylic are used for the bristles. Further, at the time of brush scrubbing, it is preferable to pour the mixed solution or water onto the substrate because the scrubbing effect is improved.

Thereafter, the glass substrate from which all thin films have been removed is regenerated by washing with water or the like and further drying.

Although the present invention has been described above according to the steps shown in the claims, for example, the steps (B) and (C) may be carried out together with brush scrubbing in amino alcohol or a mixed solution, or hydrochloric acid may be added. It is generally used in the manufacturing process of color filters, LSIs and LCDs, such as washing with water and / or drying after dipping in an acidic aqueous solution, or washing with a solvent such as isopropyl alcohol before drying to improve drying efficiency. A combination of the above methods can be used as long as they are consistent with the gist of the present invention.

The glass substrate thus obtained is again used for producing a color filter in the color filter production line.

[0020]

The present invention will be described in more detail with reference to the following examples. Example 1 A defective glass filter having a resin light-shielding layer was selected as a glass substrate having no problem. The defective product is first 20
% Hydrochloric acid aqueous solution at 30 ° C. for 1 hour and then washed with water. Next, it was immersed in a mixed solvent of monoethanolamine + dimethylformamide + diethylene glycol monobutyl ether (volume ratio 3: 6: 1) at 80 ° C. for 2 hours.
After the immersion, the material was passed through a brushing machine equipped with an acrylic brush, and brush scrubbing was performed while applying warm water of 60 ° C. Then, the glass substrate was washed with water at 25 ° C. and then dried at 100 ° C. for 2 hours to obtain a glass substrate from which all thin films were removed.
When the regenerated glass substrate was observed visually and by an optical microscope, no defects such as scratches and chips were found on the glass.

The recycled glass substrate obtained by the above method was flowed to a color filter production line to produce a color filter. The color filter produced was different from the color filter produced using a new glass substrate. It was not there. As a reliability test, heat resistance, solvent resistance, light resistance, etc. were checked, but no difference was observed between the color filter using the recycled substrate and the color filter using the new substrate.

Example 2 A defective color filter having no problem on the same glass substrate as in Example 1 was first immersed in an aqueous solution containing 5% hydrochloric acid and 32% ferric chloride at 30 ° C. for 1 hour, and then, It was washed with water.
Next, it was immersed in a mixed solution of monoethanolamine + dimethylsulfoxide (volume ratio 7: 3) at 80 ° C. for 2 hours.
After immersion, pass through a brushing machine with a nylon brush,
Brush scrubbing was performed while applying warm water of 50 ° C. Then, the glass substrate was washed with water at 25 ° C. and then dried at 100 ° C. for 2 hours to obtain a glass substrate from which all thin films were removed. When the regenerated glass substrate was observed visually and by an optical microscope, no defects such as scratches and chips were found on the glass.

When the regenerated glass substrate was poured into a color filter production line to produce a color filter, the color filter produced was not different from the color filter produced using a new glass substrate. . As a reliability test, heat resistance, solvent resistance, light resistance, etc. were checked, but no difference was observed between the color filter using the recycled substrate and the color filter using the new substrate.

Example-3 The same as Example-2 except that monoethanolamine was used as an immersion solvent for removing the color resist, the resin light-shielding layer and the overcoat layer, and the immersion was carried out at 70 ° C. for 3 hours. Processed.

When the regenerated glass substrate was poured into a color filter production line to produce a color filter, the color filter produced was not different from the color filter produced using a new glass substrate. . As a reliability test, heat resistance, solvent resistance, light resistance, etc. were checked, but no difference was observed between the color filter using the recycled substrate and the color filter using the new substrate.

[0026]

As described above, according to the present invention, it is possible to provide a method capable of reproducing a reusable glass substrate from a color filter having a defective resin light-shielding layer in a state where all thin films are removed. .

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yosuke Nakamura 5-1 Sokai-cho, Niihama-shi, Ehime Sumitomo Chemical Co., Ltd.

Claims (3)

[Claims] 1. A glass substrate for a color filter having a resin light-shielding layer, characterized in that a defective color filter having a resin light-shielding layer is treated by a method including the following steps (A) to (C). How to play. (A) Step of immersing the color filter in an acidic aqueous hydrochloric acid solution (B) Step of immersing the color filter treated in (A) in amino alcohol or a mixed solution of amino alcohol and a polar solvent (C) In the above (B) Brush scrubbing the treated color filter 2. The method for recycling a glass substrate for a color filter having a resin light-shielding layer according to claim 1, wherein the amino alcohol used in step (B) is monoethanolamine. 3. The polar solvent used in step (B) is
N, N-dimethylformamide, dimethyl sulfoxide, N-methyl-2-pyrrolidone, γ-butyrolactone, diethylene glycol monoalkyl ether, 3-
The method for recycling a glass substrate for a color filter having a resin light-shielding layer according to claim 1, which is at least one selected from methyl-3-methoxyethanol.