JP2011167661A - Recycling method of thin-type panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recycling method of a thin-type panel which is capable of recycling indium that is valuable and glass that occupies most of the weight of the wasted thin-type panel as a material by safely separating the material with less labor and energy and without a large-scaled installation from the wasted thin-screen panel. <P>SOLUTION: The recycling method of the thin-type panel comprises steps of heating the thin-type panel and stripping a polarizing plate from a panel glass. In the recycling method of the thin-type panel, it is preferable that the method further comprises the step of classifying a mixture of the stripped polarizing plate and the panel glass with the specific gravity separation. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a recycling method for thin panel waste (waste thin panel).

  In recent years, general and industrial waste in general production and consumption activities in society has increased, and global environmental problems such as illegal dumping and landfill tightness have attracted attention. The shift from an economic system to a resource recycling economic system has become an important social issue.

  In response to the situation as described above, for example, the Home Appliance Recycling Law was enforced in April 2001. Under the Home Appliance Recycling Law, as of April 2007, recycling of four home appliances such as air conditioners, televisions, refrigerators, and washing machines is obligatory. The re-commercialization rate of each product is more than 60% for air conditioners, Legal reference values of 55% or more, refrigerator 50% or more, and washing machine 50% or more are set.

  By the way, in recent years, demand for thin televisions equipped with thin panels such as liquid crystal panels, plasma display panels (PDP), organic EL panels, and field emission display panels as display components has been increasing. Due to the characteristics such as being suitable for receiving images, it has been increasing rapidly in conjunction with the recent growing interest in global environmental issues and the digitization of television broadcasting. In particular, the demand for large-screen thin TVs equipped with large thin panels has increased dramatically. Along with this, it is expected that the amount of flat-screen TV disposal will increase rapidly in the future, and in environmental activities such as recycling activities, there is an increasing demand for improving recyclability.

  Currently, flat panel TVs (thin panels) are relatively new products, and the amount of waste may be small. After the products are crushed in a waste treatment facility, a large amount of plastic is used. It is landfilled or incinerated with shredder dust.

  A typical structure of a thin panel provided for the present invention will be described. FIG. 6 is a cross-sectional view schematically showing a typical example of the thin panel 1. FIG. 6 shows a thin panel (liquid crystal panel) 1 including an active element (not shown) such as a TFT (Thin Film Transistor). The thin panel 1 of the example shown in FIG. 6 includes, for example, two panel glasses (color filter side panel glass 2a and TFT side panel glass 2b) having a thickness of about 0.4 to 1.1 mm arranged to face each other. These panel glasses (glass substrates) 2a and 2b are provided with a sealing resin body (seal material) 3 along the peripheral edge on the oppositely disposed side (inner surface side) and bonded together. Further, liquid crystal is sealed in a region sealed by the panel glasses 2a and 2b and the sealing resin body 3, and a liquid crystal layer 4 having a thickness of about 4 to 6 μm is formed.

  Moreover, in the typical thin panel 1, as shown in FIG. 6, thickness 0.2-0.4mm is provided on the opposite side (outer surface side) to the side by which each panel glass 2a, 2b is opposingly arranged. An optical film (such as a polarizing filter and a retardation film when the thin panel is a liquid crystal panel) 5 is attached with an adhesive. Furthermore, a driver IC for driving liquid crystal is connected to the peripheral portion of the thin panel, and the outside of the peripheral portion is covered with bezel plastic (not shown).

  In a typical thin panel 1, as shown in FIG. 6, a color filter 6, an antireflection film 7, a transparent conductive film 8, and an alignment film 9 are formed on the inner surface side of the color filter side panel glass 2a. The color filter 6 is made of a material mainly composed of organic matter. The antireflection film 7 is made of a thin film mainly composed of carbon. The transparent conductive film 8 is made of a thin film containing indium or the like. The alignment film 9 is made of an organic material such as polyimide.

  In the typical thin panel 1, as shown in FIG. 6, the pixel electrode 10, the bus electrode 11, the insulating film 12, the transparent conductive film 8 and the alignment film 9 are formed on the inner surface side of the TFT side panel glass 2b. ing. The transparent conductive film 8 is made of a thin film containing indium or the like. The pixel electrode 10 and the bus electrode 11 are made of a thin film containing a metal such as tantalum, molybdenum, aluminum, or titanium as a main component. The film thickness of the color filter 6, the antireflection film 7, the transparent conductive film 8, the alignment film 9, the pixel electrode 10, the bus electrode 11 and the insulating film 12 is compared with the thickness of the two panel glasses 2a and 2b. Thin enough.

  As a processing method for a liquid crystal display device or a liquid crystal panel contained in a waste product such as a defective waste liquid crystal panel or a home appliance or an information device discharged from a liquid crystal panel manufacturing factory, for example, Japanese Patent Laid-Open No. 2000-84531 (Patent Document) 1) discloses a method in which products are crushed at a liquid crystal panel manufacturing plant or waste disposal facility, and then put into a non-ferrous smelting furnace and treated as an alternative material for silica. . In the method disclosed in Patent Document 1, organic matter is completely burned in a furnace and decomposed into carbon dioxide, hydrogen, and the like.

  For thin panels, ITO (indium tin oxide) containing indium, which is a valuable material, is usually used as a transparent electrode material. Indium is used as an ITO transparent conductive film in liquid crystal panels and plasma display panels. Due to the rapid spread of thin TVs in recent years, the demand is increasing and supply is tight, and securing raw materials is important. . Therefore, from the viewpoint of effective utilization of scarce resources, it is desired that indium is also recovered in a high yield from a thin panel that has become unnecessary. Glass, which accounts for the majority of the weight of the liquid crystal panel, is preferably recycled from the viewpoint of reducing waste and valuing resources. Moreover, ITO is concerned about toxicity in a fine powder state, and it is desirable to collect it appropriately.

  In order to recover resources from the thin panel and reuse them effectively, it is desirable to separate the thin panel for each member. Moreover, in order to recycle the panel glass which occupies most of the weight of a thin panel, it is desired to pulverize the panel glass into an appropriate size to form a cullet or powder. Further, in order to recover indium which is a valuable material, it is desirable to pulverize the panel glass to an appropriate size and to elute ITO from the inner surface of the panel glass using an acidic solution or the like. However, when the thin panel is crushed, if the optical film remains attached to the outer surface of the panel glass, it cannot be efficiently crushed due to the elasticity of the optical film on the outer surface of the panel glass. Therefore, from the above viewpoint, it is desired to peel the optical film from the panel glass in order to effectively recycle the thin panel.

  As a method for separating laminated glass for separating glass from laminated glass obtained by bonding a glass plate through a film, for example, JP 2005-95855 A (Patent Document 2) has a temperature equal to or higher than the temperature at which the film evaporates, And the method of isolate | separating a film from glass by heating to the temperature below the softening point of glass and evaporating a film is disclosed.

  In addition, as a method for peeling a polarizing plate from a liquid crystal panel, for example, in JP-A No. 2002-159955 (Patent Document 3), after the polarizing plate is cut while attached to the panel, the cut polarizing plate is adhered to an adhesive tape. A method of peeling off is disclosed.

  As a method for removing resins such as a polarizing plate, a liquid crystal, and a color filter attached to a liquid crystal panel, for example, JP 2000-51829 A (Patent Document 4) discloses a waste of a liquid crystal display device as a solid heat medium. Discloses a method for recovering highly pure and recyclable glass from the waste of a liquid crystal display device by charging it into a fluidized bed in which the liquid is flowing and heating and flowing with a fluidizing gas that oxidizes resins.

  Moreover, as a method of peeling a polarizing plate from a liquid crystal panel to which a polarizing plate is attached, for example, in Japanese Patent Laid-Open No. 2002-350837 (Patent Document 5), a heated slicer is inserted between the polarizing plate and the liquid crystal panel. And the method of peeling a polarizing plate from a liquid crystal panel by moving a slicer with respect to a liquid crystal panel is disclosed.

JP 2000-84531 A JP 2005-95855 A JP 2002-159955 A JP 2000-51829 A JP 2002-350837 A

  Thin panels such as liquid crystal panels are display devices that can contribute to power and resource savings, so in the future, as the advanced information society progresses, the production volume will increase rapidly and the display area will also increase in size. As a result, the number of thin panel waste (waste thin panel) is expected to increase rapidly in the future.

  Conventionally, an appropriate thin 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, in the future, establishment of a processing method in preparation for an increase in the number of waste thin panels is urgently required.

  However, the method disclosed in Patent Document 1 described above is based on a liquid crystal display device or a liquid crystal panel included in a waste product such as a defective waste liquid crystal panel or a home appliance or an information device discharged from a liquid crystal panel manufacturing factory. After crushing the entire product at a manufacturing plant or waste treatment facility, it is put into a non-ferrous smelting furnace and treated as an alternative material for silica. In the method disclosed in Patent Document 1, organic substances such as an optical film are completely burned in a furnace and decomposed into carbon dioxide, hydrogen, and the like. Moreover, since the glass of a liquid crystal panel becomes slag and is intended to be reused as a cement material, it cannot be recycled as glass itself. Furthermore, indium is contained in the slag and cannot be recycled as an indium material.

  In order to collect and recycle valuable indium and glass from the thin panel, it is desirable to separate each member constituting the thin panel and appropriately recycle each material. In order to separate the thin panel for each member, it is necessary to separate an optical film such as a polarizing plate attached to the outer surface of the panel glass using an adhesive. The optical film is affixed to the panel glass over a wide area with an adhesive, and it is very difficult to separate the optical film by manual work or the like.

  Moreover, the adhesive of the optical film of the thin panel used as final products, such as a thin television, has deteriorated and hardened | cured by the heat | fever and light during use as a product. Moreover, the optical film itself is also deteriorated by heat and light, and is easy to tear when force is applied. Accordingly, it becomes more difficult to peel off the optical film of the thin panel used as the final product and separate it from the panel glass, and the peeling work becomes dangerous.

  Some thin panels such as liquid crystal panels that are once used as a final product and are no longer needed, or defective products that are discharged in the manufacturing process, have broken panel glass. Therefore, in order to recycle the thin panel that has become unnecessary, it is also desired to separate the optical film from the thin panel in which the panel glass is damaged.

  As described above, by separating the optical film from the thin panel, indium and glass can be effectively used as resources. Further, by separating the optical film from the thin panel in which the panel glass is damaged, it becomes possible to recycle a liquid crystal panel such as a defective product in which the panel glass discharged in the manufacturing process is damaged.

  Here, the method disclosed in Patent Document 2 described above is a method of separating a film from glass by heating the film to a temperature not lower than the temperature at which the film evaporates and not higher than the softening point of the glass and evaporating the film. It is. However, since the method disclosed in Patent Document 2 heats the film to the evaporation temperature or higher, it needs to have a high temperature and consumes energy. Moreover, the installation for detoxifying the decomposition gas of a film is required and an installation cost becomes high.

  The method disclosed in Patent Document 3 described above is a method in which an optical film attached to a liquid crystal panel is cut while attached to the panel glass, and then the cut optical film is adhered to an adhesive tape and peeled off. However, since the method disclosed in Patent Document 3 is cut while the optical film is attached to the panel glass, it is difficult to apply the method to a liquid crystal panel in which the panel glass is damaged. Furthermore, when it is applied to a liquid crystal panel used as a final product, there is a risk that the optical film will tear during peeling due to deterioration of the polarizing plate. In addition, it is necessary to process the liquid crystal panels one by one, and many liquid crystal panels cannot be processed at one time, so there is a problem in terms of cost.

  In addition, the method disclosed in Patent Document 4 described above is configured such that the waste of the liquid crystal display device is charged into a fluidized bed in which a solid heat medium is flowing, and heated and fluidized with a fluidizing gas that oxidizes resins. This is a method for recovering highly pure and recyclable glass from waste liquid crystal display devices. However, the method disclosed in Patent Document 4 consumes a great deal of energy because the heating medium is heated to a temperature at which resins such as optical films are thermally decomposed or oxidized. In addition, it is difficult to operate in a recycling plant for safety reasons.

  Furthermore, Patent Document 5 described above discloses a method of peeling an optical film from a liquid crystal panel by inserting a heated slicer between the optical film and the liquid crystal panel and moving the slicer relative to the liquid crystal panel. ing. However, the method disclosed in Patent Document 5 is difficult to apply to a damaged liquid crystal panel because a slicer is inserted between the optical film and the liquid crystal panel. Moreover, it is necessary to process each liquid crystal panel, and there is a problem in terms of cost.

  The present invention has been made to solve the above-mentioned problems, and the object of the present invention is to safely separate materials from waste thin panels with less labor and energy, without using large-scale equipment. Another object of the present invention is to provide a method for recycling a thin panel, which can be recycled as a raw material of indium which is a valuable material and glass occupying most of the weight.

  The thin panel recycling method of the present invention includes a step of heating the thin panel and peeling the polarizing plate from the panel glass.

The thin panel in the present invention is preferably a liquid crystal panel.
The thin panel recycling method of the present invention preferably peels the polarizing plate from the panel glass by heating the thin panel and applying a stress between the polarizing plate and the panel glass.

  In the thin panel recycling method of the present invention, the heating temperature of the thin panel is preferably 40 ° C to 150 ° C.

  The thin panel recycling method of the present invention preferably heats the thin panel by immersing the thin panel in a heated liquid. In this case, the liquid is preferably water.

  The thin panel recycling method of the present invention may heat the thin panel by using superheated steam.

  The thin panel recycling method of the present invention preferably adds stress between the polarizing plate and the panel glass by putting the crushed thin panel into a container and stirring the container. In this case, it is more preferable to stir the thin panel crushed in the liquid accommodated in the container, and it is more preferable that the liquid is water.

  The thin panel recycling method of the present invention preferably applies stress between the polarizing plate and the panel glass by bringing the thin panel into contact with a plurality of rotating rolls.

  In the method for recycling a thin panel according to the present invention, it is preferable to apply stress between the polarizing plate and the panel glass by hitting the thin panel with a hammer.

  The method for recycling a thin panel of the present invention preferably further includes a step of separating the peeled polarizing plate and panel glass mixture by specific gravity separation.

  In the thin panel recycling method of the present invention, it is preferable to separate the mixture of the polarizing plate and the panel glass separated by using a cyclone with specific gravity.

  In the thin panel recycling method of the present invention, it is preferable to separate the mixture of the polarizing plate and the panel glass separated by using thin flow sorting.

  According to the present invention, it is possible to separate a thin panel for each material without consuming a great deal of energy and applicable to a damaged thin panel, such as indium which is a valuable material and glass occupying most of the weight. In addition, it is possible to provide a thin panel processing method in which each material can be recycled.

It is a flowchart which shows typically a preferable example of the recycling method of the thin panel of this invention. It is a figure which shows typically the stirring apparatus 21 used suitably for the stress addition process in this invention. It is a figure which shows typically the roll 31 used suitably for the stress addition process in this invention. It is a figure which shows typically the thin flow selection method which can be employ | adopted suitably for the specific gravity separation process in this invention. It is a figure which shows the cyclonic separator 51 used suitably for the specific gravity separation process in this invention, Fig.5 (a) is a model top view, FIG.5 (b) is a schematic cross section. It is sectional drawing which shows typically the thin panel 1 of a typical example. It is an example of the result of having measured the relationship between the temperature of a thin panel, and 180 degreeC peeling strength of a polarizing plate.

  FIG. 1 is a flowchart schematically showing a preferred example of the thin panel recycling method of the present invention. The thin panel recycling method of the present invention includes a step of peeling the polarizing plate from the panel glass after heating the waste of the thin panel (waste thin panel). According to the thin panel recycling method of the present invention, it is possible to separate the members of the thin panel for each material, and it is possible to provide a processing method that can be used effectively as a resource.

  The thin panel recycling method of the present invention is conventionally known as a thin panel (liquid crystal panel) 1 having an active element (not shown) such as the TFT (Thin Film Transistor) shown in FIG. In addition to the example shown in FIG. 6, a thin panel having an appropriate structure can be provided without any particular limitation, and in addition to the example shown in FIG. Of course, panels are also applicable. Moreover, a plasma display panel (PDP) and an organic EL panel are also applicable. Hereinafter, taking the case of providing a thin panel having the structure shown in FIG. 6 as an example, each step of the thin panel recycling method of the present invention will be described in detail with reference to FIG.

  As shown in the example shown in FIG. 1, the thin panel recycling method of the present invention applies a stress between the heating process (step S3) for heating the waste thin panel and the optical film and the panel glass of the heated thin panel. It is preferable to basically include a stress applying step (step S4) for adding and separating the optical film and the panel glass. The thin panel recycling method of the present invention may further include a specific gravity separation step (step S5) of separating the mixture of the separated polarizing plate and the panel glass by specific gravity separation, as in the example shown in FIG. preferable. Further, as in the example shown in FIG. 1, before the heating step (step S3), a glass type selection step (step S1) for selecting a thin panel for each type of panel glass and a rough crushing step for roughly crushing the panel glass. It is preferable to further include (Step S2).

[1] Glass type selection step In the example shown in FIG. 1, first, as a glass type selection step, thin panels are selected according to the type (type) of panel glass used (step S1). The composition of the panel glass differs depending on the glass manufacturer, or the glass type and product number. Therefore, in order to reuse the collected glass as a material for panel glass, for example, 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.

  In the present invention, thin glass panel glass may be sorted by type using a fluorescent X-ray apparatus. In this case, specifically, soft X-rays are directly irradiated onto a thin panel using an energy dispersive X-ray fluorescence analyzer. Thereby, fluorescent X-rays having energy peculiar to each element contained in the panel glass of the thin panel are emitted. By counting this fluorescent X-ray for each energy with a fluorescent X-ray sensor, it is measured (analyzed) what element is contained in what proportion in the panel glass of the thin panel. By examining the chemical composition of the panel glass in advance for each product type and comparing these values with the measured values for the panel glass of a thin panel, the panel glass can be obtained in a short time, reliably and economically for each glass product type. Can be selected automatically. Moreover, the display of the glass type may be provided in advance on the panel glass of the thin panel.

  In the case where the panel glass is recycled for use where there is no problem even if a plurality of types of panel glass are mixed, the glass type selection step may be omitted.

[2] Rough crushing step In the example shown in FIG. 1, the thin panel is roughly crushed in the subsequent rough crushing step (step S2). When the rough crushing step is performed after the glass type selection step (step S1) as in the example shown in FIG. 1, a thin panel using a single type of panel glass selected as described above. Do it every time. Each of the color filter side panel glass and the TFT side panel glass with the optical film is crushed.

  Various types of commercially available crushers can be used for crushing thin panels, and the type of crusher is not particularly limited, but it can be easily crushed with less dust generation, which adversely affects the environment. From the standpoint that the running cost is low and the running cost is low, a biaxial shearing type crusher is more preferable. In addition, the biaxial shearing type crusher has advantages such that it is easy to obtain crushed pieces of uniform size, the generation ratio of fine powder is small, and the crushed pieces are finally easily reused as glass cullet. ing. Although the size of the crushed pieces is not particularly limited, 1 to 100 mm is preferable from the viewpoint of efficiency in the stress applying step (step S4) described later.

  In addition, in the flowchart shown in FIG. 1, although the case where a glass kind selection process (step S1) is performed before this rough crushing process (step S2) is illustrated, it is not limited to this order, rough crushing After performing the process, the glass type selection process may be performed, or the rough crushing process may be performed without performing the glass type selection process.

[3] Heating Step In the example shown in FIG. 1, in the subsequent heating step, the thin panel is heated (step S3). Since the optical film is attached to the surface of the thin panel as shown in FIG. 6, in the recycling method of the thin panel of the present invention, first, in the heating step, first, the adhesive force between the optical film and the panel glass is increased. Weaken and separate efficiently in the stress applying process described later. By separating the optical film from the panel glass, the optical film and the panel glass can be separated and recovered for each material. Moreover, by separating the elastic optical film from the panel glass, it becomes possible to easily pulverize the panel glass when it is recycled.

  The optical film is affixed on the panel glass surface using, for example, an acrylic adhesive. By heating the acrylic adhesive to 40 to 150 ° C., the optical film can be softened and the adhesive force can be weakened, and the optical film and the panel glass can be easily separated.

  As a specific heating method, for example, a thin panel is immersed in a liquid. As temperature of a liquid, 40-150 degreeC is preferable and 70-120 degreeC is more preferable. If the heating temperature is less than 40 ° C., the adhesive may not be sufficiently softened. When the heating temperature exceeds 150 ° C., it reaches near the heat-resistant temperature of the optical film and the strength of the optical film is deteriorated. In the stress applying step (step S4) and the specific gravity separation step (step S5) described later, the optical film May be damaged and a sufficient separation effect may not be obtained.

  The liquid for immersing the thin panel for heating is not particularly limited, and examples thereof include water, a hydrocarbon-based organic solvent, an alcohol-based organic solvent, and the like. It is preferable to use water because it can be heated without causing problems.

  The heating time is preferably 10 seconds to 600 seconds, and more preferably 60 seconds to 300 seconds. If the heating time is less than 10 seconds, a sufficient heating effect may not be obtained, and if the heating time exceeds 600 seconds, the effect tends to decrease with respect to time. By immersing in hot water, heating can be performed without taking time.

  Moreover, in the said heating process (step S3), you may employ | adopt the method of spraying superheated steam as another heating method, for example. In this case, the temperature of the superheated steam to be sprayed is preferably 150 ° C. or less, and more preferably in the range of 100 to 120 ° C. When the temperature of the superheated steam to be sprayed exceeds 150 ° C., the strength of the optical film is deteriorated because it reaches the heat resistance temperature of the optical film, and a stress applying step (step S4) and a specific gravity separation step (step S5) described later are performed. As a result, the optical film may be damaged, and a sufficient separation effect may not be obtained. The heating time is preferably 1 second to 600 seconds, and more preferably 5 seconds to 30 seconds. Specifically, there is a method in which a thin panel is placed in an oven or the like equipped with a heated water vapor generating mechanism and left standing in a state where superheated water vapor is generated. By using superheated steam, heat conduction is promoted and heating can be performed quickly.

  Thus, by heating the thin panel, the strength of the adhesive that bonds the optical film and the panel glass is reduced by the heat energy. The panel glass and optical film base material hardly lose strength at 150 ° C, so the strength of only the bonded part will decrease, and the optical film and panel glass will remain as they are, and they will be easily separated in the stress application process described later. Is possible.

  In the present invention, the heating step (step S3) is not performed as an independent step, but it is of course possible to apply stress simultaneously with heating in the stress applying step (step S4) described later. For example, as will be described later, heating can be performed while applying stress between the polarizing plate and the panel glass by stirring in hot water. At that time, as described above, the heating temperature is preferably 40 to 150 ° C., and the heating time is preferably 10 seconds to 600 seconds. Moreover, in the said heating process, as long as heating temperature can be made into the suitable range of 40-150 degreeC, you may make it utilize the waste heat of a boiler, etc.

  In addition, although the case where this heating process (step S3) is performed before a stress addition process (step S4) is illustrated in the flowchart shown in FIG. 1, it is not limited to this order. Further, when the thin panel is crushed, it can be heated at the same time.

[4] Stress Application Step In the example shown in FIG. 1, in the subsequent stress application step, a stress is applied between the optical film and the panel glass to separate the optical film and the glass (step S4). In the thin panel recycling method of the present invention, it is preferable that stress is applied between the polarizing plate and the panel glass by putting the crushed thin panel into a container and stirring it.

  Here, FIG. 2 is a diagram schematically showing the stirring device 21 that is preferably used in the stress applying step in the present invention. The stirring device 21 in the example illustrated in FIG. 2 includes a container 22 and a rotating body 23 installed in the container 22. When the thin panel is put into such a stirrer 21, the thin panel receives stress from the rotating body 23 in the stirrer 21, moves in the container 22, and collides with each other. When thin panels collide with each other, stress is also applied between the optical film and the panel glass, and the optical film and the panel glass are peeled off at the bonded portion where the adhesive force is weakened. According to this method, since the stress is applied by the collision of the thin panels, there is an advantage that the wear of the blade and the wear deterioration of the container hardly occur.

  The thin panel may be put into the stirring device 21 while being taken out from the product, or the thin panel taken out from the product may be roughly crushed and then put into the stirring device 21. When the thin panel is put into the stirring device 21 in the state of being taken out from the product, the thin panel is crushed in the stirring device 21 and stress is applied between the optical film and the panel glass. The glass is separated.

  Moreover, when the thing taken out from the product is roughly crushed and then put into the stirring device 21, the energy is consumed for the crushing and the energy is consumed for peeling the optical film, so that the efficiency is improved. In this case, the size of rough crushing is preferably 1 to 100 mm as described above. By roughly crushing the thin panel to a size of 50 mm or less, it becomes easy to put into the stirring device 21 and to easily apply a shear stress by stirring. Further, when the thin panel is roughly crushed to 1 mm or less, the stress between the optical film and the panel glass generated when the thin panel collides is reduced, and the optical film and the panel glass are hardly separated.

  As a rotation speed of the rotary body 23 of the stirring apparatus 21, 20000 rpm or less is preferable. When the rotational speed is 20000 rpm or more, the efficiency is low with respect to energy consumption. Further, in order to sufficiently apply stress and process in a short time, the rotational speed of the rotating body 23 is preferably 1000 rpm or more.

  Moreover, in this invention, you may make it stir the said thin panel crushed in the liquid accommodated in the container. Thereby, fine powder is not scattered and the working environment is not deteriorated. Further, the ITO fine powder used as a material for the liquid crystal panel is concerned about toxicity, and the dispersion of the fine powder of the liquid crystal panel can be prevented by stirring in the liquid. Further, by storing the heated liquid in the container and stirring the thin panel therein, the liquid is stirred while weakening the adhesive strength of the adhesive, and the separation efficiency of the optical filter is improved. In addition, although it does not restrict | limit especially as a liquid, Since stirring work is safe and the process after use is easy, water is used suitably.

  Moreover, FIG. 3 is a figure which shows typically the roll 31 used suitably for the stress addition process in this invention. In the stress applying step in the present invention, stress may be applied between the polarizing plate and the panel glass by bringing the thin panel into contact with a plurality of rotating rolls. In this case, instead of the stirring device 21 as shown in FIG. 2 described above, the thin panel 1 is passed through the gaps between the rotating rolls 31 as shown in FIG. When using such a some roll 31, it is more preferable that the rotational speed of the some roll 31 to rotate differs from each other. Thereby, a shear stress is added to a thin panel and an optical film and panel glass are isolate | separated. The rotation speed of the roll 31 is preferably 10 to 1000 rpm. This is because when the number of rotations of the roll 31 is less than 10 rpm, the processing time tends to be long, and when the number of rotations of the roll 31 exceeds 1000 rpm, the passing time between the rolls is sufficiently short. This is because the stress tends not to be applied.

  When the roll 31 as shown in FIG. 3 is used in the stress applying step, the thin panel is preferably put into the gap of the roll 31 while being taken out from the product. Thereby, the contact area of the roll 31 and a thin panel becomes large, and a shear stress becomes large. Needless to say, the thin panel in a broken state or the thinly crushed thin panel may be put into the gap of the roll 31.

  It is preferable to use a roll 31 having a protrusion 32 formed on the surface. Since the protrusion 32 is formed on the roll surface, the frictional force with the thin panel is increased, and the shear stress applied between the optical film and the panel glass can be increased.

  Further, in the stress applying step in the present invention, the thin panel is struck with a hammer without using the above-described stirring device 21 (FIG. 2) and the plurality of rolls 31, so that the polarizing plate and the panel glass are placed between each other. You may make it add stress. In this case, there is an advantage that a large stress can be applied in a short time. Any conventionally known appropriate hammer can be used without any particular limitation. In this case, the operator may hit the thin panel with a hammer, or a commercially available device equipped with a hammer may be used.

  After passing through the stress applying step, a mixture of the optical film and the panel glass is obtained from the thin panel. The optical film is separated from the outer surface of the panel glass, and the glass is also crushed because the elasticity of the optical film does not hinder the crushing unlike the liquid crystal panel to which the optical film is attached. Therefore, when eluting indium with hydrochloric acid or the like in the panel glass processing step (step S6) described later, hydrochloric acid is easy to permeate and high elution efficiency is obtained. Moreover, it classify | categorizes according to a crushing piece size, It can recycle | reuse for the recycle use of various glass according to a particle size. For example, a crushed piece having a relatively large particle size can be put into a melting furnace as it is, and can be used for remelting glass. In addition, the fine powder can be recycled for cement materials and building materials.

  The obtained mixture of the optical filter and the thin panel glass is separated into an optical film and a panel glass in a specific gravity separation step (step S5), which will be described later, and can be collected for each material and appropriately recycled for each material. it can.

[5] Specific Gravity Separation Step In the example shown in FIG. 1, in the subsequent specific gravity separation step, the optical film and the panel glass are separated by specific gravity separation from the mixture of the optical film and the panel glass obtained in the stress applying step (step S4). Separate (step S5). The optical film has a base material made of TAC or the like and a specific gravity of 1.2 to 1.4. Therefore, since it is small compared with the specific gravity 2.3-2.6 of panel glass, it can isolate | separate into an optical film and panel glass by using a specific gravity difference. Specific examples of the specific gravity separation include conventionally known techniques such as cyclone and floating sorting.

  FIG. 4 is a diagram schematically showing a thin flow sorting method that can be suitably employed in the specific gravity separation step in the present invention. As a separation method using the specific gravity difference, for example, a thin flow sorting method can be used. There is a method in which a mixture of the optical film and the panel glass is put into water flowing along the table surface on the inclined vibration table 41. In such a method, the light specific gravity particles, that is, the optical film, flow in a thin stream and travel farther, so that they can be separated from the heavy specific gravity particles, that is, the panel glass. It is also possible to use a method in which the heavy specific gravity particles settle in the gaps of the crosspieces by using a Wilfrey table as shown in FIG. 4 in which a plurality of crosspieces 42 are provided in parallel on the vibration table.

  When performing thin flow sorting using a Wilfrey table as in the example shown in FIG. 4, the table 41 has a table surface (upper surface) of 3 to 5 from the top to the bottom as it goes from the right side to the left side in FIG. It is inclined so that water supplied from above flows downward. Further, the table is provided with a plurality of low bars 42 arranged in the horizontal direction, and a supply port for supplying a mixture of the optical film and the panel glass above the right part of the table in FIG. 43 is provided.

  In the thin flow sorting using such a Wilfrey table, the panel glass of the supplied mixture of the optical film and the panel glass settles into a gap between the bars. The panel glass that has settled in the gap between the crosspieces moves fast to the left and slowly to the right, and moves to the left due to inertial force. On the other hand, the optical film does not settle but rides in a thin stream and flows downward with water. Thus, the panel glass is separated on the left side of the table in FIG. 4 and the optical film is separated on the lower side.

  Further, in the specific gravity separation step in the present invention, a cyclone may be used instead of the thin flow sorting method shown in FIG. Here, FIG. 5 is a diagram showing a cyclonic separation device 51 preferably used in the specific gravity separation step in the present invention, FIG. 5 (a) is a schematic top view, and FIG. 5 (b) is a schematic cross-sectional view. . As shown in FIG. 5, the air flow including the mixture of the optical film and the panel glass introduced from the powder introduction port 51 flows downward while turning along the side surface of the inner surface of the device, and is accelerated at the conical portion at the lower portion of the device. Is done. The accelerated airflow reaches the lower end of the device and rises upside down. The airflow that has risen swirls around the center in the same direction and is discharged from the discharge port 52. At this time, the panel glass having a large specific gravity is separated by centrifugal force, falls along the side surface, and settles. The settled panel glass is discharged from the discharge port 52. The optical film having a small specific gravity rises with the air flow and is discharged from the exhaust port 53.

  Moreover, in the specific gravity separation process in the present invention, for example, a jig sorter, an air table, or the like may be used as a separation method using the specific gravity difference.

  In this manner, the mixture of the optical film and the panel glass obtained in the stress applying step (step S4) can be divided into the optical film and the panel glass by a separation method using a specific gravity difference. The separated optical film can be separated and recycled for each material. The optical film can also be heat recovered. Panel glass can collect rare metals and collect glass in the panel glass processing step described later.

[6] Panel Glass Processing Step FIG. 1 further shows a panel glass processing step (step S6) for processing the panel glass separated and recovered in the above-described specific gravity separation step (step S5) and separating and recovering indium from the panel glass. Examples including are shown. The panel glass separated and recovered in the specific gravity separation step (step S5) is attached with indium tin oxide (ITO) containing rare metal indium as a transparent electrode. For this reason, it can be recovered as indium hydroxide, for example, by immersing in hydrochloric acid to dissolve ITO and neutralizing the indium-containing hydrochloric acid solution. By obtaining an indium-containing hydrochloric acid solution, it becomes possible to concentrate and recover indium by a method using an anion exchange resin or the like.

  In the case where the above-described glass type selection process (step S1) is performed, the panel glass after collecting indium has already been selected according to the glass type in the process. Therefore, the collected panel glass is a single type of glass, and can be reused (material recycling) by adding and mixing the panel glass to the raw glass or replacing the raw glass with the raw glass. That is, it can be classified according to the size of the crushed pieces and recycled for various glass recycling applications according to the particle size. For example, a crushed piece having a relatively large particle size can be put into a melting furnace as it is, and the glass can be remelted and used for applications such as plate glass. In addition, the fine powder can be recycled for cement materials and building materials.

  According to this method, energy is not consumed as in combustion, and chemicals that are difficult to process such as strong acids and strong alkalis are not used. Therefore, this method has a low environmental impact and can be implemented in home appliance recycling plants. And efficient separation is possible. In addition, valuable materials such as indium and glass can be efficiently recovered, and resources can be used effectively.

  The thin panel recycling method of the present invention only needs to include at least the heating step (step S3) (preferably the heating step (step S3) and the stress applying step (step S4)) as described above. It is not limited to the procedure shown in the flowchart of FIG. 1, some of the steps shown in FIG. 1 may be deleted or replaced, and steps not shown in FIG. 1 are added as necessary. May be.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these.

<Example 1>
The temperature dependence of the polarizing plate peel strength of the thin panel was measured. A liquid crystal panel taken out from a commercially available liquid crystal television was separated into a color filter side panel glass and a TFT side panel glass, and the color filter side panel glass cut into a size of 10 mm × 50 mm was used as a sample. The peel strength of the polarizing plate when the sample temperature was 20 ° C., 60 ° C., and 80 ° C. was evaluated by a 180 ° C. peeling test using an autograph AG-I manufactured by Shimadzu Corporation. The 180 ° C. peeling test was performed according to JIS Z0237. The peeling speed was 0.2 mm / min.

  FIG. 7 is a graph showing the measurement result of the temperature dependence of the polarizing plate peeling strength, and shows an example of the result of measuring the relationship between the temperature of the thin panel and the 180 ° C. peeling strength of the polarizing plate. Based on the peel strength at 20 ° C, the retention rate is 57% at 60 ° C and 43% at 80 ° C, and the peel strength of the polarizing plate is reduced by heating. It was confirmed that the polarizing plate and the panel glass were easily separated.

<Example 2>
The thin panel was roughly crushed to 50 mm, immersed in hot water having the temperature shown in Table 1 for 60 seconds, and heated. Then, the thin panel stirring was performed using the stirring apparatus provided with the rotary body as shown in FIG. The container capacity of the stirring device was 200 mL. The rotation speed of the stirring device was varied between 2000 and 10000 rpm. The stirring time was 60 seconds. Table 1 shows the remaining ratio (%) of the panel glass on the optical film.

  It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. 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.

  DESCRIPTION OF SYMBOLS 1 Thin panel, 2a Color filter side panel glass, 2b TFT side panel glass, 3 Seal resin body, 4 Liquid crystal layer, 5 Optical film, 6 Color filter, 7 Antireflection film, 8 Transparent conductive film, 9 Orientation film, 10 pixels Electrode, 11 Bus electrode, 12 Insulating film, 21 Stirrer, 22 Container, 23 Rotating body, 31 Roll, 32 Protrusion, 41 Table, 42 Bar, 43 Supply port, 51 Cyclone separator, 52 Discharge port, 53 Exhaust port .

Claims (15)

  A method for recycling a thin panel, comprising a step of heating the thin panel and peeling the polarizing plate from the panel glass.   2. The thin panel recycling method according to claim 1, wherein the thin panel is a liquid crystal panel.   The method for recycling a thin panel according to claim 1 or 2, wherein the thin panel is heated to peel the polarizing plate from the panel glass by applying a stress between the polarizing plate and the panel glass.   The method for recycling a thin panel according to any one of claims 1 to 3, wherein the heating temperature of the thin panel is 40 to 150 ° C.   The method for recycling a thin panel according to any one of claims 1 to 4, wherein the thin panel is heated by immersing the thin panel in a heated liquid.   6. The thin panel recycling method according to claim 5, wherein the liquid is water.   The method for recycling a thin panel according to any one of claims 1 to 4, wherein the thin panel is heated by using superheated steam.   The thin panel recycling method according to claim 3, wherein stress is applied between the polarizing plate and the panel glass by putting the crushed thin panel into a container and stirring the container.   The method of recycling a thin panel according to claim 8, wherein the thin panel crushed in a liquid contained in a container is stirred.   The method for recycling thin panels according to claim 9, wherein the liquid is water.   The method for recycling a thin panel according to claim 3, wherein stress is applied between the polarizing plate and the panel glass by bringing the thin panel into contact with a plurality of rotating rolls.   The method of recycling a thin panel according to claim 3, wherein stress is applied between the polarizing plate and the panel glass by hitting the thin panel with a hammer.   The method for recycling a thin panel according to any one of claims 1 to 12, further comprising a step of separating the separated polarizing plate and panel glass mixture by specific gravity separation.   The method for recycling a thin panel according to claim 13, wherein the mixture of the polarizing plate and the panel glass separated by using a cyclone is separated by specific gravity.   14. The thin panel recycling method according to claim 13, wherein a specific gravity separation is performed on the peeled polarizing plate and panel glass mixture by using thin flow sorting.

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