JP2007125459A - Treatment method and treatment apparatus of liquid crystal panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a treatment method of a liquid crystal panel, which enables the decomposition of organic materials from the liquid crystal panel using little work and energy to recover indium in a transparent conductive film, and at the same time, enables a reuse of glass. <P>SOLUTION: The treatment method of the liquid crystal panel comprises the decomposition and treatment of the organic materials by mixing and heating an oxide semiconductor and the liquid crystal panel. By using an acid aqueous solution dissolving a metal thin film and a metal contained in liquid crystal glass where the organic materials are decomposed, a dissolved metal solution and glass are recovered. Indium is recovered from the dissolved metal solution. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a processing method and a processing apparatus for a liquid crystal panel.

  In recent years, products such as home appliances, personal computers, and portable terminals using liquid crystal panels are rapidly spreading, and the number of waste liquid crystal panels is also rapidly increasing. In the formation of a recycling-oriented society where coexistence with the environment is expected, it is desired to recycle these waste liquid crystal panels and use resources effectively.

  At present, liquid crystal display devices and liquid crystal panels contained in waste such as home appliances and information devices are small in amount of waste. Along with a large amount of shredder dust, it is landfilled or incinerated.

  As a processing method for liquid crystal display devices and liquid crystal panels contained in wastes such as defective liquid crystal panels and home appliances and information devices discharged from liquid crystal panel manufacturing plants, liquid crystal panel manufacturing plants and waste processing facilities Then, after crushing the whole product, a method of putting it in a non-ferrous smelting furnace and treating it as an alternative material for silica stone has been proposed and implemented in part (see Patent Document 1).

  As a method for treating liquid crystal panels, a method has been proposed in which waste liquid crystal panels are brought into contact with a heat medium in an atmosphere below the melting point of the glass and above the decomposition temperature of the liquid crystal compound to decompose the organic matter containing the liquid crystal compound and separate the glass and metal. (See Patent Document 2).

  As a method for recovering the liquid crystal material used in the liquid crystal panel, a method of decomposing the liquid crystal material using a supercritical fluid has been proposed (see Patent Document 3).

Note that the above-described liquid crystal panel is obtained by injecting and enclosing a liquid crystal material inside two bonded glass substrates and attaching a polarizing plate (resin) to the outside of each glass substrate.
JP 2000-84531 A JP 2001-137804 A JP 2002-126688 A

  Since the liquid crystal panel is a display device that can contribute to power saving and resource saving, it is predicted that the production volume will increase rapidly and the display area will increase with the progress of the advanced information society in the future. Along with this, the number and amount of waste liquid crystal panels are expected to increase rapidly in the future.

  Conventionally, an appropriate liquid crystal panel processing method has not been established, and the fact is that technology establishment is delayed compared to CRT (Cathode Ray Tube) and other home appliances and components. Therefore, it is urgently required in the future to establish a processing method for increasing the number of waste liquid crystal panels.

  In some cases, liquid crystal panels are used as non-ferrous smelting furnaces as an alternative material for silica stone. However, in this case, the liquid crystal panels are used only as cement materials because the glass components become slag and are reused as glass materials. Are not reused. Organic matter is completely burned in the furnace. Indium contained in the metal and the metal thin film is not recycled.

  Liquid crystal is a very expensive material, and there is a voice to collect and reuse it, but the amount of liquid crystal used in the liquid crystal panel is very small, and it is difficult to collect it without deterioration, so it is small It is desirable to properly treat the liquid crystal with effort and energy. Furthermore, although it is known that the liquid crystal is so small that its toxicity is not a problem, it is desirable that the liquid crystal is appropriately decomposed because it is a material that is very difficult to decompose naturally.

  A method of decomposing liquid crystal with a supercritical fluid has been proposed, but considering the equipment that embodies it, the initial cost of normal equipment increases due to pressure and corrosion resistance requirements, and the running cost also increases. . Further, since a large amount of energy is used, the amount of carbon dioxide emission increases and the burden on the environment also increases.

  ITO (indium tin oxide) used as a transparent conductive film of a liquid crystal panel contains indium which is a valuable material. Indium is used as an ITO transparent conductive film in thin display devices such as liquid crystal display devices and plasma display panels, and its supply is tight due to the rapid spread of thin televisions in recent years. Therefore, it is desired to recover indium in a high yield from a liquid crystal panel that has become unnecessary from the viewpoint of effective utilization of scarce resources.

  In order to recover indium at a high yield, it is necessary to recover the ITO transparent conductive film after removing the liquid crystal adhering to the ITO transparent conductive film and the organic matter of the alignment film. Although there is a method using an organic solvent as a method for removing organic substances, since a large amount of organic solvent is used, it is difficult to treat the chemical solution.

  As a method for decomposing organic matter, there is a method in which a liquid crystal panel is heated to a temperature equal to or lower than the melting point of glass at a temperature equal to or higher than the decomposition temperature of organic matter, and is decomposed by combustion. As described above, energy consumption is increased due to heating. Carbon dioxide emissions increase and the burden on the environment increases.

  Furthermore, it is desirable to recycle the glass, which accounts for most of the weight of the liquid crystal panel, from the viewpoint of reducing waste and saving resources. In order to recycle glass, it is necessary to remove organic substances, metals and metal thin films adhering to the glass surface.

  The present invention has been made in view of the above-mentioned conventional problems, and its purpose is to decompose organic substances using less labor and energy, recover indium in a transparent conductive film, and reuse glass. It is providing the processing method of the liquid crystal panel which is.

  The present invention provides a method for treating a liquid crystal panel, wherein an oxide semiconductor powder and a liquid crystal panel are mixed and heated to decompose an organic substance contained in the liquid crystal panel.

  According to another aspect of the present invention, there is provided a liquid crystal characterized in that exhaust gas generated by decomposing organic substances contained in the liquid crystal panel is purified by a detoxifying device by mixing and heating the oxide semiconductor powder and the liquid crystal panel. A panel processing method is provided.

  The present invention also provides a method for treating a liquid crystal panel, wherein the oxide semiconductor powder is recovered and reused by separating a mixture of the oxide semiconductor powder and the metal solution after the decomposition treatment.

  In addition, the present invention provides a method for treating a liquid crystal panel, which comprises recovering indium by decomposing an organic substance and then dissolving the metal and the metal thin film attached to the liquid crystal panel using an acidic aqueous solution. .

  In addition, the present invention provides a method for treating a liquid crystal panel, wherein organic substances are decomposed and a glass substrate recovered by removing a metal and a metal thin film is recycled as glass.

  Further, the present invention includes (a) a glass substrate type selection step, (b) a liquid crystal panel crushing step, (c) an organic matter decomposition step, (d) a metal and metal thin film removal step, Provided is a method for treating a liquid crystal panel including a step of mixing and heating an oxide semiconductor powder and a liquid crystal panel.

  The present invention also includes a reaction vessel for mixing and heating oxide semiconductor particles and a liquid crystal panel to decompose organic substances contained on the surface of the liquid crystal panel, an oxygen supply means for introducing oxygen to promote oxidation, a decomposition Exhaust gas exhausting means for exhausting the gas generated by the above, an agitator for uniformly mixing the oxide semiconductor and the liquid crystal panel, a means for heating the oxide semiconductor, and an abatement apparatus for adsorbing harmful components in the exhaust gas A processing apparatus for a liquid crystal panel comprising:

  Moreover, this invention provides the processing apparatus of the said liquid crystal panel provided with the crushing material separation apparatus which isolate | separates and collects glass cullet (glass piece).

  In addition, the present invention provides a processing apparatus for the liquid crystal panel, which includes an apparatus for separating oxide semiconductor powder and metal solution.

  The method for treating a liquid crystal panel of the present invention has a configuration in which organic substances such as a polarizing plate, a liquid crystal, and an alignment film are completely decomposed using an oxide semiconductor powder. Thereby, an organic substance is decomposed | disassembled with a process of 400 degrees C or less and little energy, and there exists an effect that metals, such as indium, and a glass substrate can be collect | recovered easily and cheaply.

  The method for treating a liquid crystal panel of the present invention has a configuration in which exhaust gas generated by decomposing an organic substance is absorbed by a scrubber or the like and wastewater treated. Thereby, there exists an effect that it becomes possible to decompose | disassemble organic substance with little effort and energy, and to reduce the load with respect to an environment.

  The processing method of the liquid crystal panel of this invention is a structure which collect | recovers a metal and a metal thin film using acidic aqueous solution. Thereby, there is an effect that indium which is a rare metal can be recovered economically with high purity.

  The method for treating a liquid crystal panel of the present invention is configured to collect and reuse the oxide semiconductor powder by separating a mixture of the oxide semiconductor powder and the metal solution. Thereby, there is an effect that organic matter can be decomposed at a low cost while producing almost no waste.

  And according to said structure, while being able to decompose | disassemble organic substances, such as a polarizing plate, a liquid crystal, and an alignment film, indium which is a rare metal contained in a metal and a metal thin film is recoverable. Glass cullet can also be reused. Therefore, there are various effects that enable an economical waste liquid crystal panel treatment that hardly discharges waste.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
<LCD panel>
An example of a schematic configuration of a liquid crystal panel applicable to the liquid crystal panel processing method of the present invention is shown in FIG. This liquid crystal panel is, for example, a liquid crystal panel that is discarded in a liquid crystal panel manufacturing factory, a liquid crystal panel that is disassembled and discharged from a liquid crystal display apparatus that is discarded in a liquid crystal display assembly factory, or a product that applies liquid crystals. They are a liquid crystal panel that is discharged after disassembling a product discarded in a manufacturing factory, and a liquid crystal panel that is discharged after dismantling an information display device, a video display device, and the like discarded in the market. The illustrated liquid crystal panel includes an active element (not shown) such as a TFT (Thin Film Transistor). Of course, the present invention is also applicable to a duty liquid crystal panel such as a TN (twisted nematic) liquid crystal panel and an STN (super twisted nematic) liquid crystal panel.

  As shown in FIG. 2, the liquid crystal panel has two glass substrates (color filter side glass substrate 1 a and TFT side glass substrate 1 b) having a thickness of about 0.7 to 1.1 mm arranged to face each other. . These glass substrates are bonded between the inner surfaces by a sealing resin body (sealing material) 2 provided along the peripheral edge portions. The region sealed by the color filter side glass substrate 1a / TFT side glass substrate 1b and the sealing resin body 2 is filled (sealed) with a liquid crystal layer 3 having a thickness of about 4 to 6 μm. ing. A polarizing plate 4 having a thickness of about 0.2 to 0.4 mm is attached to the outer surface of each glass substrate with an adhesive. The polarizing plate 4 is a laminate of the polarizing film 11, the reinforcing protective film 12 and the adhesive layer 13 as shown in the configuration of the polarizing plate shown in FIG. 3.

The color filter 5, the antireflection film 6, the transparent electrode 7, and the alignment film 8 are formed on the inner surface of one color filter side glass substrate 1a as in the configuration of the color filter side glass shown in FIG. The color filter 5 is made of a material mainly composed of organic matter. The antireflection film 6 is made of a thin film such as metallic chromium. The transparent electrode 7 is made of a thin film containing indium or the like. The alignment film 8 is made of an organic material. Further, the pixel electrode 9, the bus electrode 10 and the alignment film 8 are formed on the inner surface of the other TFT side glass substrate 1b as in the configuration of the TFT side glass shown in FIG. The pixel electrode 9 is made of a transparent thin film containing indium or the like. The bus electrode 10 is made of any metal thin film such as tantalum, aluminum or titanium. The film thickness of the color filter 5, the antireflection film 6, the transparent electrode 7, the alignment film 8, the pixel electrode 9, and the bus electrode 10 is sufficiently smaller than the thickness of the two glass substrates.
<Liquid crystal panel processing method>
The liquid crystal panel processing method according to the present embodiment includes a glass selection step of selecting a glass substrate according to the type of glass, a step of crushing the liquid crystal panel with a polarizing plate, a polarizing plate included in the liquid crystal panel, and a liquid crystal An organic substance decomposition step for decomposing the alignment film, and a metal and metal thin film peeling step for removing the transparent electrode film included in the liquid crystal panel. Next, a processing method (process) of the liquid crystal panel for recycling will be described below.

  FIG. 1 is a flowchart showing the steps of the liquid crystal panel processing of the present invention. First, the outline of the processing method will be described based on this. In the processing method of a liquid crystal panel (liquid crystal panel with a polarizing plate), first, the glass of the glass substrate is sorted by product type (type) (glass substrate type sorting step). After that, the liquid crystal panel is crushed according to the glass type (liquid crystal panel crushing step). As a result, the liquid crystal 3 and the alignment film 8 sealed in the liquid crystal panel are exposed and become a crushed material. A specific method for sorting the glass and crushing the liquid crystal panel will be described later.

  Next, the crushed material is mixed with the oxide semiconductor powder and heated to decompose organic matter such as a polarizing plate, a liquid crystal, and an alignment film contained in the crushed material (S1, organic matter decomposition step). Thereafter, the metal and the metal thin film remaining on the crushed material, that is, the transparent electrode 7, the pixel electrode 9, and the bus electrode 10 are removed by immersing them in an acidic aqueous solution (S2, metal and metal thin film peeling step). The mixture of the glass cullet, the metal solution and the oxide semiconductor powder is sieved to separate and collect the glass cullet (S3, glass cullet separation step). Glass cullet is reused as glass. Thereafter, the metal solution and the oxide semiconductor powder are separated from the mixture (S4, oxide semiconductor powder separation step). The separated oxide semiconductor powder is reused. Indium, a rare metal, is recovered from the metal solution.

≪Glass substrate sorting process≫
In the sorting step, the glasses of the glass substrates (color filter side glass substrate 1a and TFT side glass substrate 1b in FIG. 2 as an example) are sorted by type. The composition of glass varies depending on the glass manufacturer, glass type, product number, and the like. Therefore, in order to reuse the collected glass as a material for, for example, a glass substrate, it is necessary to sort a wide variety of glasses by type. Further, even when the collected glass is reused as a material for general glass, for example, it may be required to sort the glass by type to some extent.

  As a specific method for selecting the glass of the glass substrate of the liquid crystal panel according to the type, a display of the glass type is provided on the liquid crystal panel, or a fluorescent X-ray apparatus is used. Thereby, a glass kind can be selected reliably and economically in a short time.

  As shown in FIG. 6 which is a schematic perspective view showing a label of a glass type, the glass type display method is affixing a glass type display 21 such as a seal on which a glass type is printed on the liquid crystal panel 22, or What is necessary is just printing or engraving of characters, symbols, barcodes, etc., or surface processing. By identifying this display, it is possible to reliably and economically sort the glass substrates by type in a short time.

  A specific method for selecting a glass type using an X-ray fluorescence analyzer is to directly irradiate a glass substrate with soft X-rays using an energy dispersive X-ray fluorescence analyzer. Thereby, fluorescent X-rays having energy peculiar to each element contained in the glass substrate are emitted. The fluorescent X-rays are counted (analyzed) by counting what energy is contained in the glass substrate by counting each energy with a fluorescent X-ray sensor. By checking the chemical composition of each glass in advance and comparing these values with the measured values of the glass substrate, the glass substrate should be selected reliably and economically in a short time by glass type. Can do.

≪LCD panel crushing process≫
The panel crushing step is performed for each glass substrate of a single variety. Specifically, the crushing is performed on the color filter side glass substrate 1a and the TFT side glass substrate 1b having the polarizing plate 4 shown in FIG. In the crushing process of the liquid crystal panel, commercially available various types of crushers can be used. The type of crusher is not particularly limited, but it is biaxial shearing from the viewpoints that it can be easily crushed with less dust generation, does not adversely affect the environment, and the running cost is low. A type of crusher is more preferable. The crusher also has advantages such that it is easy to obtain a crushed product of uniform size, the generation ratio of fine powder is small, and the crushed product is finally easily reused as a glass cullet. Although the size of crushing is arbitrary, 15 mm or less is preferable.

≪Organic substance decomposition process≫
In the organic matter decomposition step of S1 shown in FIG. 1, organic matters such as a sealing resin body, a polarizing plate, a liquid crystal, and an alignment film adhering to the crushed material are efficiently decomposed using an oxide semiconductor powder. Thereby, the organic matter can be completely decomposed and removed without using a great deal of energy and organic solvent, and discharge of solid waste can be prevented.

  As the oxide semiconductor powder, anatase, rutile, brookite type titanium oxide can be used. Although the size of the powder is arbitrary, for example, the particle diameter is in the range of 10 to 50 nm, and the smaller the better, the better the decomposition efficiency. Examples of the titanium oxide powder include ST01 manufactured by Ishihara Sangyo. The mixing ratio between the oxide semiconductor and the crushed material is a mixing ratio at which the oxide semiconductor sufficiently covers the surface of the crushed material. For example, the weight ratio of the oxide semiconductor to the crushed material is preferably 1: 1. As a specific method for decomposing the organic substance, a method is used in which the crushed material with the polarizing plate, the liquid crystal, and the alignment film adhered thereto and titanium oxide are mixed, and stirred and heated while supplying oxygen to oxidatively decompose the organic substance. .

  When heated, the oxide semiconductor powder generates thermal equilibrium carriers and oxidizes and decomposes nearby molecules. When mixed with liquid crystal, the oxide semiconductor powder is dispersed in the liquid crystal, and further heated, the liquid crystal is decomposed by the oxidative decomposition action of the oxide semiconductor powder. The heating temperature is preferably 350 to 400 ° C. The reason is that sufficient carriers are generated for the decomposition of the organic matter, and no combustion reaction occurs and the decomposition efficiency is maximized. The thermoplastic resin used for a polarizing plate etc. among organic substances will be in a molten state by heating. A decomposition reaction at the solid / liquid interface occurs between the molten resin and the oxide semiconductor powder, and the decomposition reaction is accelerated. Thermosetting resins such as alignment films and seal resin bodies are decomposed into gases by the action of the oxide semiconductor powder decomposing and oxidizing nearby molecules by the decomposition reaction at the solid / solid interface.

  In addition, as a method of decomposing organic matter, there is a method of decomposing organic matter by mixing titanium oxide as a photocatalyst with organic matter and irradiating with ultraviolet rays, but in this case, the reaction does not proceed in the part where light does not reach, so decomposition There is a problem that the efficiency is low and the running cost of the light source lamp is high. In contrast, the organic matter decomposition process of the present invention excites the carrier by heating, so that the reaction proceeds if the temperature rises even in the part that is not irradiated with light, so that the decomposition efficiency is increased and the light source lamp is not used. There is no cost.

≪Purification of exhaust gas≫
The gas (exhaust gas) generated by the decomposition is water, carbon dioxide gas, nitrogen gas, fluorine gas, or the like. First, dust is separated from exhaust gas by a dust collector. Examples of the dust collector include a cyclone and a bag filter, but are not particularly limited. The separated dust component consists of a glass component and a resin component, and returns to the organic matter decomposition step again. The gas that has passed through the dust collector is purified by the abatement device. Examples of the abatement apparatus include a scrubber, but are not particularly limited.

≪Metal and metal thin film peeling process≫
In the metal and metal thin film peeling step of S2 shown in FIG. 1, an antireflective film, a transparent electrode, a pixel electrode, a bus remaining on the crushed material are obtained by immersing the crushed material of the liquid crystal panel in which the organic material is decomposed in an acidic aqueous solution. It peels by dissolving the electrode thin film. In this step, the acidic aqueous solution becomes a metal solution, and the crushed material becomes glass cullet. For example, hydrochloric acid, sulfuric acid, nitric acid, or aqua regia is used as the acidic aqueous solution. In particular, hydrochloric acid having the fastest dissolution rate is desirable.

  The higher the temperature of the acidic aqueous solution, the faster the dissolution rate and the shorter the processing time becomes. On the other hand, the danger of handling increases, and the problems such as corrosion of various devices due to the generated acid vapor and deterioration of the working environment. Will be even bigger. Accordingly, the heating temperature is preferably 40 ° C. or lower, and more preferably room temperature. The dissolution time is not limited because it depends on the temperature, but it is 1 hour or longer, preferably 4 hours or longer. Dissolution is carried out with stirring.

  The stirring method is not particularly limited, and there is a method of vibrating or rotating in the vertical and horizontal directions.

≪Glass cullet separation process≫
In the glass cullet separation step of S3 shown in FIG. 1, the mixture in the metal and metal thin film peeling step is sieved to separate into a glass cullet and a mixture of oxide semiconductor powder and metal solution. The separated glass cullet is reused. The sieve mesh is preferably 100 μm.

  The collected glass cullet has already been sorted by glass type in the sorting step. That is, the glass cullet is a single type of glass and has a chemical composition that is the same as that of the raw glass for the glass substrate. Therefore, the glass cullet can be reused (material recycling) by being added to and mixed with the raw material glass or replaced with the raw material glass. When reusing, for example, the glass cullet may be melted together with the raw glass in a melting furnace. Furthermore, the recovered glass cullet can be reused as a material for general glass, for example. Since the glass substrate of the liquid crystal panel is collected in a glass cullet state, the space required for storage, transportation and reprocessing can be reduced, and storage and transportation can be easily performed. it can.

≪Oxide semiconductor powder separation process≫
In the oxide semiconductor powder (titanium oxide) separation step S4 shown in FIG. 1, the mixture of the oxide semiconductor powder and the metal solution is separated into the oxide semiconductor powder and the metal solution. Examples of the separation method include filtration. The separated oxide semiconductor powder is reused. Although fine powder of crushed material may be mixed into the oxide semiconductor powder, it can be used as it is because the decomposition performance of the organic substance does not change.

≪Indium recovery≫
By this method, the metal and the metal thin film adhering to the liquid crystal panel are completely removed. As a method for recovering indium from the obtained metal solution, for example, sodium hydroxide is added to the metal solution for neutralization to precipitate and remove tin hydroxide. Further, there is a method of recovering indium as a metal by electrolytically collecting an indium solution from which tin is removed. Thus, indium, which is a rare metal that has formed a thin film, can be recovered and regenerated economically with high purity.
<Processing device>
≪Decomposition of organic substances≫
FIG. 7 shows an organic matter decomposition apparatus. This is one form of the processing device of the liquid crystal panel in the present invention. The reaction vessel 31 has an inlet 36 for crushed material and oxide semiconductor powder, a discharge port 38 for crushed material and oxide semiconductor powder, an oxygen supply port 35 as oxygen supply means, and an exhaust port as exhaust gas exhaust means. 37 is provided. The container is placed on the vibration device 32. A heater 33 as a heating means for the reaction vessel 31 is installed at the lower part of the cylindrical vessel, and the temperature is controlled by a thermostat. A side of the reaction vessel 31 includes a dust collector 39 that separates dust from the exhaust gas, and a detoxifier 34 that adsorbs harmful components from the gas that has passed through the dust collector 39. Moreover, the glass outlet 41 is provided with the glass separation apparatus 41, and isolate | separates glass and a metal solution with a sieve. Furthermore, an oxide semiconductor powder separation device 42 for separating the oxide semiconductor powder from the metal solution is provided.

  The crushed material and the oxide semiconductor powder are supplied to the reaction vessel 31 from the inlet 36. The order of adding the crushed material and the oxide semiconductor powder powder is not particularly limited. After charging the crushed material and the oxide semiconductor powder, the container is vibrated up and down, left and right, or rotated to uniformly disperse the oxide semiconductor powder and the crushed material.

  The heater 33 is a means for heating the reaction vessel 31. Any heating method such as an electric heater method or a flame method may be used. It is even better to use infrared rays or electromagnetic induction that emit less carbon dioxide. Moreover, what can control temperature is good. The heating temperature is preferably 350 to 400 ° C. at which sufficient carriers are generated.

  The organic matter adhered to the crushed material in the reaction vessel 31, that is, the polarizing plate, the liquid crystal, the alignment film, and the oxide semiconductor powder react to decompose the organic matter and generate gas. The generated gas (exhaust gas) is exhausted from an exhaust port 37 which is an exhaust means. The exhaust gas is water, carbon dioxide gas, nitrogen gas, fluorine gas or the like. The exhaust gas separates dust by the dust collector 39. Examples of the dust collector include a cyclone and a bag filter, but are not particularly limited. The separated dust component is composed of a glass component and a resin component, opens the valve 43, passes through the re-injection port 40, and is again input into the organic matter decomposition apparatus. The gas that has passed through the dust collector is purified by the abatement device 34. Examples of the abatement apparatus include a scrubber, but are not particularly limited.

  During the decomposition treatment, the reaction vessel is heated while supplying oxygen through the oxygen supply port 35. Thereby, the low molecular weight fragment undergoes a combustion reaction with oxygen and is completely decomposed. Air may be simply supplied.

≪Metal and metal thin film peeling and glass cullet separation≫
An acidic aqueous solution is introduced from the inlet 36 into the reaction vessel 31 containing the crushed material after decomposition of organic matter and the oxide semiconductor powder, and immersed for a predetermined time. Thereafter, the valve 44 is opened, the mixture of the metal solution, glass cullet, and oxide semiconductor powder is taken out from the discharge port 38 and sieved by the glass separation device 41, whereby the glass cullet, the metal solution, and the oxide semiconductor are collected. Separate into powder mixture. The sieve mesh is preferably 100 μm. For example, hydrochloric acid, sulfuric acid, nitric acid, or aqua regia is used as the acidic aqueous solution. Hydrochloric acid with the fastest dissolution rate is desirable.

  As a dissolution method, an acidic aqueous solution is introduced into the reaction vessel 31 containing the crushed material from which organic substances have been removed. As heating temperature, 40 degrees C or less is desirable. Room temperature is more desirable. The dissolution time is not limited because it depends on the temperature, but it is 1 hour or longer, preferably 4 hours or longer. Dissolution is carried out with stirring. The stirring method is not particularly limited, and there is a method of vibrating or rotating in the vertical and horizontal directions.

The separated glass cullet is reused.
≪Separation process of oxide semiconductor powder and metal solution≫
Thereafter, the mixture of the oxide semiconductor powder and the metal solution is separated into the oxide semiconductor powder and the metal solution in the oxide semiconductor powder separator 42. The separated oxide semiconductor powder is reused. Indium is recovered from the metal solution. As a method, for example, sodium hydroxide is added to the metal solution to neutralize, and tin hydroxide is precipitated and removed. Further, there is a method of recovering indium as a metal by electrolytically collecting a metal solution from which tin has been removed.

  In the process of the liquid crystal panel as described above, after sorting by glass type, the liquid crystal panel is crushed with a polarizing plate. The organic matter of the polarizing plate, liquid crystal, and alignment film attached to the crushed material is decomposed using the oxide semiconductor powder, and the metal and the metal thin film are recovered using an acidic aqueous solution. The glass cullet obtained by decomposing the residual organic substance adhering to the crushed material from which the metal and the metal thin film have been removed using the oxide semiconductor powder can be subjected to material recycling. In this way, a method for treating a liquid crystal panel that hardly generates waste can be achieved.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  It is possible to provide a method for treating a liquid crystal panel that can suppress the amount of waste liquid crystal panel dumped to a landfill as much as possible and can effectively use resources.

It is a flowchart which shows the general | schematic process of the processing method of the liquid crystal panel in one Embodiment of this invention. It is sectional drawing which shows the outline of a structure of the liquid crystal panel processed with the processing method of this invention. It is sectional drawing which shows the structure of the polarizing plate of the liquid crystal panel processed with the processing method of this invention. It is sectional drawing which shows the structure of the color filter side glass of the liquid crystal panel processed with the processing method of this invention. It is sectional drawing which shows the structure of the TFT side glass of the liquid crystal panel processed with the processing method of this invention. It is a schematic perspective view which shows the label of the glass kind used for the glass selection process in the processing method of this invention. It is general | schematic sectional drawing which shows the structure of the organic substance decomposition | disassembly apparatus in the processing method of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1a Color filter side glass substrate, 1b TFT side glass substrate, 2 Seal resin body, 3 Liquid crystal layer, 4 Polarizing plate, 5 Color filter, 6 Antireflection film, 7 Transparent electrode, 8 Orientation film, 9 Pixel electrode, 10 Bus electrode , 11 Polarizing film, 12 Reinforcement protective film, 13 Adhesive layer, 21 Glass type display, 22 Liquid crystal panel, 31 Reaction vessel, 32 Vibrating device, 33 Heater, 34 Detoxifying device, 35 Oxygen supply port, 36 Inlet port, 37 Exhaust Mouth, 38 outlet, 39 dust collector, 40 re-inlet, 41 glass separator, 42 oxide semiconductor powder separator, 43, 44 valve.

Claims (9)

  A method for treating a liquid crystal panel, comprising decomposing an organic substance contained in the liquid crystal panel by mixing and heating the oxide semiconductor powder and the liquid crystal panel.   A treatment method for a liquid crystal panel, wherein exhaust gas generated by decomposing organic substances contained in the liquid crystal panel is purified by a detoxifying device by mixing and heating the oxide semiconductor powder and the liquid crystal panel.   A method for treating a liquid crystal panel, wherein the oxide semiconductor powder is recovered and reused by separating the mixture of the oxide semiconductor powder and the metal solution after the decomposition treatment according to claim 1.   2. The method for treating a liquid crystal panel according to claim 1, wherein after the organic substance is decomposed, indium is recovered by dissolving the metal and the metal thin film attached to the liquid crystal panel using an acidic aqueous solution.   5. The method for treating a liquid crystal panel according to claim 4, wherein the glass substrate recovered by decomposing the organic matter and further removing the metal and the metal thin film is recycled as glass. (A) Glass substrate type sorting step,
(B) Liquid crystal panel crushing process,
(C) organic matter decomposition step,
(D) metal and metal thin film peeling step,
(C) is a processing method of a liquid crystal panel using the processing method according to claim 1. A reaction vessel in which oxide semiconductor particles and a liquid crystal panel are mixed and heated to decompose organic substances contained on the surface of the liquid crystal panel;
Oxygen supply means for introducing oxygen to promote oxidation;
Exhaust gas exhaust means for exhausting the gas generated by the decomposition,
A stirring device for uniformly mixing the oxide semiconductor and the liquid crystal panel;
Means for heating the oxide semiconductor;
A detoxification device that adsorbs harmful components in the exhaust gas;
Liquid crystal panel processing apparatus.   The processing apparatus of the liquid crystal panel of Claim 7 provided with the crushed material separator which isolate | separates and collects glass cullet.   The processing apparatus of the liquid crystal panel of Claim 7 provided with the apparatus which isolate | separates oxide semiconductor powder and a metal solution.

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