JPH11197641A - Detoxifying treatment of glass surface - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a glass surface detoxifying treatment method comprising a combination of a physical treatment method of sandblasting (grinding removal) and an one-pack chemical treatment using min. acidic or alkaline chemicals in the detoxifying treatment of the liquid crystal flat panel display of a computer. SOLUTION: A physical treatment process consisting of a process 20 crushing a flat display panel and a process 30 mixing crushed glass with a grinding material mutually to strike and rub them mutually in a tank in order to develop sandblasting effect and superposed glass peeling effect to finly grind the glass is combined with a chemical treatment processes 40 immersing the ground glass in various washing agents to chemically wash the same.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to non-polluting treatment of liquid crystal flat panel displays used in electronic devices such as computers, and more particularly to a process of crushing and pulverizing a flat panel display and rubbing and shaving a surface film. The glass is then immersed in a relatively small amount of an acid-based or alkaline-based cleaning agent to remove chemicals with a high environmental risk remaining on the surface of the glass. The present invention relates to a method for detoxifying a glass surface of a liquid crystal display which achieves zero emission without generating pollution.

[0002]

2. Description of the Related Art A cathode ray tube (CRT = CRT) has been used as a display device of electronic equipment such as a computer. However, at present, when one personal computer is required, the length and size of the cathode ray tube occupy the desk, and there is a problem. In order to reduce the size and thickness, a CRT (CRT) is used as a display device. Liquid crystals began to be used. Devices using liquid crystals can reduce the size or thickness of the entire device, and have been devised so that they are easily visible compared to the initial stage of development, and have been used in various small electronic devices and many devices have been developed. A flat panel display used in a display device using this liquid crystal is made of glass, and has a sandwich structure in which a color filter glass substrate and an element glass substrate are bonded together and a liquid crystal is injected therebetween.

On the other hand, when discarding electronic devices equipped with these liquid crystal display devices and when discarding defective products generated in the manufacturing process, the treatment of the glass portion is limited to the number of pieces adhering to the glass surface. The species must be stripped and detoxified. Disposal without treatment merely moves pollution to a disposal site, and incomplete delamination cannot reuse glass, thus wasting resources. The following are the methods for peeling and cleaning the surface adhered film for detoxifying flat panel displays.

[0004] As shown in the experimental result report, (Sample A
-1 to A-8), it is necessary to use three liquids of an acid-based cleaning agent, an alkali-based cleaning agent, and a fluorine-based cleaning agent, which may cause secondary pollution. is there.
Therefore, a physical treatment method of sand blasting the glass surface to remove the adhered film is partially adopted, but in the sand blast grinding and removal method of Sample A-9,
Disassembly is not possible because it takes time and effort to peel off the lamination, because it is necessary to peel off the laminated products and the glass plates that have been stacked and stuck together as a waste, one by one. There is.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to detoxify a flat panel display of a liquid crystal used for electronic equipment such as a computer without causing pollution.
To achieve zero emissions by processing glass materials into a reusable state. Particularly, a physical treatment method represented by sand blasting removal method and a minimum amount of acid chemicals that complement it , Alkaline chemicals,
Another object of the present invention is to provide a glass surface detoxification treatment method in combination with a chemical treatment method that requires only one solution of a fluorine-based chemical at an extremely low concentration.

[0006]

Means for Solving the Problems To achieve the above object, a method for detoxifying a glass surface according to the present invention is a method for forming a film comprising a chemical agent such as chromium adhered to the glass surface of a flat panel display. This is a method of peeling off the material so that the treated glass can be reused as a resource, and a step of crushing a flat panel display made of glass, and producing the same effect as sand blasting and overlapping glass pieces. To get the effect of peeling,
A physical treatment process consisting of mixing crushed glasses with abrasives, colliding and rubbing in a tank and crushing into fine particles, and immersing the crushed glass in various cleaning agents for chemical cleaning treatment This is a configuration composed of a combination of chemical processing steps. Further, the pulverizing step and the chemical treatment step can be performed at the same time, and furthermore, the pulverizing step and the pulverizing step can be performed at the same time. It is also possible to adopt a configuration in which the treatment step and the chemical treatment step can be performed simultaneously.

[0007]

The method for detoxifying a glass surface according to the present invention comprises the steps described in detail above, and firstly crushes a flat panel display made of glass appropriately. In this crushing step, the effect of peeling off the glass superimposed on the expected sandblasting effect cannot be obtained sufficiently. A pulverization step in which an abrasive is mixed is performed to obtain a sufficient amount, and the mixture is pulverized into fine particles. As a result, the glass pieces become considerably smaller, and the adhered film on the surface is also considerably peeled off. Next, it is immersed in a cleaning agent to perform a chemical cleaning process. In cleaning, most of the coating film has been peeled off in the physical treatment process, so there is no need to use dangerous fluorine-based cleaning agents except in rare cases, and a small amount of acid-based cleaning. Only one solution of the cleaning agent or the alkaline cleaning agent is used, and a pollution-free treatment better than the conventional example can be realized.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a flowchart A to D of the present invention, FIG. 2 is a cross-sectional view showing the structure of the surface of the liquid crystal flat panel display, and FIG. 3 is an enlarged view of the surface of the liquid crystal flat panel display. The method 10 for detoxifying a glass surface according to the present invention includes: A) a step 20 of crushing a flat panel display made of glass; mixing the crushed glass with an abrasive; The method includes a step 30 and a step 40 of immersing the crushed glass in various cleaning agents to perform a chemical cleaning treatment. Method 1 for detoxifying glass surface according to the present invention
Another embodiment of 0 comprises B) a step 50 of simultaneously performing the crushing step 30 and the cleaning step 40. Still another embodiment includes C) a step 60 of simultaneously performing the crushing step 20 and the crushing step 30, and a cleaning step 40. Still another embodiment comprises D) a step 70 of simultaneously performing the crushing step 20, the crushing step 30, and the cleaning step 40.

FIG. 2 shows an example of a structure composed of glass parts, which is the center of a liquid crystal flat panel display. The color filter 11 is made of chrome (C
r) or a black matrix (BM) 13 made of carbon black and a colored layer 14 made of red, green and blue photosensitive materials
And a plastic coat 15 coated thereon, and a transparent electrode (IT
O) An element glass substrate 18 with a liquid crystal 17 interposed therebetween
It is composed of The element glass substrate 18 includes a pixel electrode 19 made of ITO on a glass substrate, source and gate electrodes made of Cr, Al or Ti, and
The passivation film is made of N.

FIG. 3 is a structural diagram of a typical TFT element 21 as an element. The TFT element 21 has a gate electrode 22 made of Cr or Al on a glass substrate 18, an insulating film 23 made of SiN thereon, and an IT
O to the pixel electrode 19 and the amorphous Si 24
There is a source electrode 25 made of Cr or Ti, on which a
This is a configuration coated with a passivation film 26 made of SiN.

The step 20 of crushing the flat panel display made of glass is a step of physically crushing the glass. Usually, a glass crusher is used, but the means for crushing is not particularly limited. However, it is not efficient to crush the glass into fine pieces (fine particles) in this step. That is, it is necessary to repeat the crash operation for a long time to crush the particles until they become fine pieces (granular), and even if it takes time, the expected sand blast effect of peeling off the adhered film cannot be sufficiently obtained.

A step 30 of mixing the crushed glass and the abrasive and crushing and crushing them into fine pieces while rubbing each other.
Is a process of mixing a physically crushed glass and an abrasive and bumping them in a container, and rubbing to remove a film adhering to the glass surface, thereby producing a sand blast effect. Each time the glass surface is divided into small pieces, the glass surface peels off due to the impact, exposing the surface of the glass coating film, and reducing the remaining peeling. In addition, in this step, the coating film such as carbon black is almost completely peeled off. This is an important point of the present invention. The abrasive and the container used in this step are not particularly limited.

Step 40 is a step of immersing the crushed glass in various cleaning agents to perform a chemical cleaning treatment. In the normal case, to remove the adhered film on the glass surface cleanly,

As described in the experimental result report, three types of cleaning agents, that is, acid type, alkali type and fluorine type, had to be used. In the pulverizing step of the present invention, the adhered film on the glass surface is largely peeled off, and in particular, the carbon black-based film is almost completely peeled off, and furthermore, since it is a fine piece, the contact area with the cleaning agent becomes large. Since the cleaning effect is remarkably improved, only a small amount of one solution of an acid-based or alkali-based cleaning agent needs to be used except in extremely rare cases. This is also a major point of the present invention. In addition to using a small amount of acid-based or alkaline-based cleaning agents, it is possible to avoid the use of dangerous fluorine-based cleaning agents except in extremely rare cases.
This is a cleaning method that suppresses the occurrence of secondary pollution and greatly contributes to achieving zero emissions.

Steps 50, 60 and 70 are methods for detoxifying the glass surface by eliminating the steps of the embodiment A) to the extent technically possible based on the embodiment A) and achieving cost reduction. .

According to Denki Engineering Co., Ltd. (4-1-2 Kawaguchi, Kazo-shi, Saitama), “Report on AX Glass Peeling and Recycling Process,” dated July 15, 1997: Purpose: Removal of deposits on the surface of liquid crystal display glass. Test date: July 10, 1997 3. Deposits: A type (composite deposits Cr, ITO, Al, SiN, alkali resin, etc.) B type (carbon black or Cr, Red, Green, Blue dye, 3. ITO, plastic, etc.) Test result A type Sample processing method and chemical system Temperature Time Result Name of chemical used A-1 Chemical treatment DEC (MB) Acid system 70 ° C 30 minutes Non-peelable A-2 Chemical treatment DEC (MB) Acid system 70 ° C 30 minutes DEC (BM) Acid system Room temperature 15 minutes Non-peelable Sample processing method and chemical system Temperature Time Result Chemical name used A-3 Chemical treatment DEC (MB) Acid system 70 ° C 20 minutes + DEC (Clean) Alkaline 80 ° C 10 minutes + DEC (BM) Acid system Room temperature 15 minutes Non-peelable A-4 Chemical treatment DEC (MB) Acid system 70 ° C 20 minutes + DEC (Clean) Alkaline 80 ° C 10 minutes + DEC (BM) Acid system room temperature 15 minutes + DEC (F2) Fluorine room temperature 2-3 minutes Peelable A-5 Chemical treatment DEC (MB) Acid system 70 ° C 30 minutes + DEC (F2) Nitrogen-based room temperature 2-3 minutes Peelable A-6 Chemical treatment DEC (MB) Acid system 70 ° C 20 minutes + DEC (F2) Fluorine room temperature 2-3 minutes + DEC (clean) alkaline system 80 ° C 15 Min. Peelable A-7 Chemical treatment DEC (MB) Acid 70 ° C 20 min + DEC (F2) Fluorine Normal temperature 2-3 min + DEC (MB) Acid 70 ° C 15 min Non-peelable A-8 Chemical Treatment DEC (F2) Fluorine-based room temperature 2-3 minutes + DEC (clean) alkali-based 80 ° C 10 minutes Peelable A-9 Physical treatment Blasting Blasting may cause processing blemishes and remaining film material Sample treatment method and chemical system Temperature Time Result Chemical name used A-10 Physical treatment plus Chemical treatment Blast DEC (MB) Acid system 70 ° C 20 minutes Peelable B type Sample treatment method Fine chemicals lineage Temperature Time Results Using Product name B-1 chemical treatment DEC (clean) alkaline 80 ° C 10 minutes peelable 5. Conclusions Regarding the A type, the treatment method of A-10 is optimal as a result of considering the risk of secondary pollution and the cost. For the B type, since the target release film is only carbon black, it can be easily removed with an alkaline one-solution.

[0017]

The method for detoxifying a glass surface according to the present invention has the following effects because it has the above-described configuration. (1) The crushed flat panel display is further mixed with an abrasive and crushed, and the glass that has overlapped in the process of being crushed into fine pieces is peeled off, and the chromium and the chromium attached to the glass surface of the display are removed. Most of the chemical agents such as liquid crystal material are peeled off, and the glass of the display is finely divided. Compared with the above method, the cost can be significantly reduced. (2) Avoid the use of high-concentration fluorine-based and environmentally hazardous high-concentration fluorine-based and large-volume acid- and alkali-based cleaning agents, and use only small amounts of acid-based or alkali-based or rarely special cases in 3 to 5%. Since it is sufficient to use a fluorine-based cleaning agent having an extremely low concentration, the occurrence of secondary pollution can be easily prevented. (3) The detoxified glass fine pieces (fine grains) can be reused as a high quality glass raw material, which greatly contributes to resource saving and zero emission. (4) The coating is not limited to the color-like flat panel display, and the coatings attached to the glass surfaces of all the flat panel displays can be peeled off and made harmless.

[Brief description of the drawings]

FIG. 1 is a flowchart of a method for detoxifying a glass surface according to the present invention.

FIG. 2 is a sectional view showing a structure of a central portion of a flat panel display.

FIG. 3 is an enlarged view of a TFT element of a flat panel display.

[Explanation of symbols]

 Reference Signs List 10 Detoxification method of glass surface 11 Color filter 12 Glass substrate 13 Black matrix (BM) 14 Colored layer 15 Plastic coat 16 Transparent electrode 17 Liquid crystal 18 Element glass substrate 19 Pixel electrode 21 TFT element 22 Gate electrode 23 Insulating film 24 Amorphous Si 25 Source electrode 26 Passivation film 20 Crushing step 30 Crushing step 40 Chemical cleaning treatment step 50 Simultaneous crushing / cleaning step 60 Simultaneous crushing / crushing step 70 Simultaneous crushing / crushing / washing step

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazuhisa Kuroda 4-1-2, Kawaguchi, Kazo City, Saitama Prefecture Inside Nitta Engineering Co., Ltd. (72) Inventor Hideki Nishida 3300 Hayano, Mobara City, Chiba Prefecture Hitachi, Ltd. Electronic Devices Division (72) Inventor Takeo Sawaguchi 3300 Hayano, Mobara-shi, Chiba Electronic Devices Division, Hitachi, Ltd. (72) Inventor Toshihiko Tojo 3300 Hayano, Mobara-shi, Chiba Hitachi, Ltd. Electronic Devices Division

Claims (4)

[Claims] 1. A method in which a film-forming material made of a chemical agent such as chromium or the like and a chemical agent such as a liquid crystal attached to a glass surface of a flat panel display is subjected to a peeling treatment so that the treated glass can be used as a resource. Then, in order to obtain the same effect as sandblasting and to remove the overlapping pieces of glass, mix the crushed glass with the abrasive in the tank to obtain the same effect as crushing the flat panel display made of glass. A glass comprising a combination of a physical treatment step comprising a step of crushing and crushing into fine particles and a chemical treatment step of immersing the crushed glass in various cleaning agents for chemical cleaning treatment. Surface detoxification treatment method 2. The method for detoxifying a glass surface, wherein the step of pulverizing and the step of chemical treatment can be performed simultaneously. 3. The method for detoxifying a glass surface, wherein the step of crushing and the step of crushing can be performed simultaneously. 4. The method for detoxifying a glass surface, wherein the method for detoxifying a glass surface includes simultaneously performing a physical treatment step including a crushing step and a pulverizing step and a chemical treatment step.