JP2011224475A - Method of recycling liquid crystal panel and apparatus for separating and recovering glass - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of recycling a liquid crystal panel, which safely separates materials from a waste liquid crystal panel with less labor and energy without using large equipment and recycles indium being a valuable substance and glass taking a large amount of the weight into materials.SOLUTION: The method of recycling a liquid crystal panel includes: a step of crushing a liquid panel to which a polarizer is adhered, which is a crushing step S4 where the liquid crystal panel is crushed and, at the same time, a panel glass and a polarizer are detached by applying different travel speeds between the panel glass and the polarizer which are components of the liquid crystal panel: and a separation step S5 where the polarizer and the panel glass, which have been detached in the crushing step, are separated.

Description

  The present invention relates to a method for recycling a liquid crystal panel waste (waste liquid crystal panel) and a glass separation and recovery apparatus.

  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 this situation, for example, the Home Appliance Recycling Law was enforced in April 2001. Under the Home Appliance Recycling Law, as of March 2010, the recycling of four home appliances such as air conditioners, televisions, refrigerators, and washing machines is obligatory. Legal reference values are set for 55% or more of type TVs, 50% or more of flat-screen TVs, 60% or more of refrigerators, and 65% or more of washing machines.

  By the way, in recent years, demand for thin TVs 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 flat-screen TVs equipped with large LCD 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.

  At present, flat panel TVs (liquid crystal panels) are relatively new products, and the amount of waste is 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 the liquid crystal panel used in the present invention will be described. FIG. 5 is a cross-sectional view schematically showing a typical example of the liquid crystal panel 1. FIG. 5 shows a liquid crystal panel 1 provided with an active element (not shown) such as a TFT (Thin Film Transistor). The liquid crystal panel 1 of the example shown in FIG. 5 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.

  Further, in a typical liquid crystal panel 1, as shown in FIG. 5, a thickness of about 0.2 to 0.4 mm is provided on the opposite side (outer surface side) of each panel glass 2a, 2b to the oppositely arranged side. A polarizing plate (optical film such as a polarizing filter and a retardation film) 5 is attached with an adhesive. Further, a driver IC for driving liquid crystal is connected to the peripheral portion of the liquid crystal panel, and the outside of the peripheral portion is covered with bezel plastic (not shown).

  In a typical liquid crystal panel 1, as shown in FIG. 5, 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 a typical liquid crystal panel 1, as shown in FIG. 5, a pixel electrode 10, a bus electrode 11, an insulating film 12, a transparent conductive film 8 and an 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 liquid crystal 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 from a liquid crystal panel that is no longer needed in a high yield. 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 liquid crystal panel and reuse them effectively, it is desirable to separate the liquid crystal panel into members. Moreover, in order to recycle the panel glass which occupies most of the weight of the liquid crystal 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 liquid crystal 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 liquid crystal panel.

  As a method of peeling a polarizing plate from a liquid crystal panel, for example, in Japanese Patent Application Laid-Open No. 2002-159955 (Patent Document 2), after a polarizing plate is cut while attached to the panel, the cut polarizing plate is adhered to an adhesive tape and peeled off. A method is disclosed.

  Moreover, as a method for separating laminated glass from laminated glass or the like obtained by bonding a glass plate through a film, for example, Japanese Patent Application Laid-Open No. 2004-181321 (Patent Document 3) discloses a film using a roll crusher. A method is disclosed in which the glass is peeled by applying a tensile strain to the film after primary crushing of the upper glass.

  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 with a polarizing plate attached thereto, for example, in Japanese Patent Application Laid-Open No. 2000-189939 (Patent Document 5), a liquid crystal panel is crushed and a polarizing plate remains attached. A method of separating a panel glass piece into a polarizing plate and a glass substrate using a solvent is disclosed.

JP 2000-84531 A JP 2002-159955 A JP 2004-181321 A JP 2000-51829 A JP 2000-189939 A

  Since the LCD panel is a display device that can contribute to power and resource savings, it is predicted that the production volume will increase rapidly and the display area will increase with the progress of the advanced information society. Along with this, the number of liquid crystal panel wastes (waste liquid crystal panels) is 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 parts. Therefore, in the future, establishment of a processing method in preparation for an increase in the number of waste liquid crystal 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 liquid crystal panel, it is desirable to separate each member constituting the liquid crystal panel and appropriately recycle each material. In order to separate the liquid crystal 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.

  Further, the adhesive for the optical film of the liquid crystal panel used as the final product is deteriorated by heat and light during use as a product and is cured. Moreover, the optical film itself is also deteriorated by heat and light, and is easy to tear when force is applied. As a result, it becomes more difficult to peel off the optical film of the liquid crystal panel used as the final product and separate it from the panel glass, and the peeling work becomes dangerous.

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

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

  Here, the method disclosed in Patent Document 2 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 2 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.

  Also in the method disclosed in Patent Document 3 described above, the optical film itself is deteriorated by heat and light, and is easily torn when a force is applied. When tensile strain is applied to the optical film after the primary crushing, it is difficult to give a desired tensile strain due to tearing or breakage of the optical film itself, and it can be applied even when the panel glass is damaged. Have difficulty.

  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.

  Furthermore, the method disclosed in Patent Document 5 described above is a method of crushing a liquid crystal panel and separating a panel glass piece with a polarizing plate on a polarizing plate and a glass substrate using a solvent. Operation in a recycling plant is difficult from the viewpoint of safety because of processing costs and the use of solvents that are harmful to the human body.

  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 liquid crystal panels with little effort and energy, without using large-scale equipment. Another object of the present invention is to provide a method for recycling a liquid crystal panel, which can recycle and recycle valuable indium and glass occupying most of the weight as materials, and an apparatus that can be suitably used for the method.

  The method for recycling a liquid crystal panel of the present invention is a step of crushing a liquid crystal panel with a polarizing plate attached thereto, and by providing different moving speeds to the panel glass and the polarizing plate constituting the liquid crystal panel, It includes a crushing step of peeling the panel glass and the polarizing plate simultaneously with the crushing of the panel, and a specific gravity separation step of separating the specific gravity of the polarizing plate and the panel glass peeled by the crushing step.

  In the method for recycling a liquid crystal panel according to the present invention, it is preferable that the polarizing plate and the panel glass are separated by specific gravity using a cyclone or thin flow sorting in the specific gravity separation step.

  The present invention is also an apparatus used for the crushing step in the above-described liquid crystal panel recycling method of the present invention, which has a pair of two rolls and has a large-diameter projection array in the circumferential direction of one roll surface. And a small-diameter projection row is formed in the circumferential direction so as not to interfere with the large-diameter projection row on one roll surface, and the large-diameter projection row and the small-diameter projection row are staggered. The present invention also provides a glass separation and recovery apparatus having means for shifting and combining the rolls on the surface of each roll in the axial direction, and further providing means for giving a peripheral speed difference between the rolls.

  In the glass separation and recovery apparatus of the present invention, it is preferable that the peripheral speed difference is in a range of 1.5 to 10 times.

  The glass separation / recovery device of the present invention preferably further comprises means for heating the liquid crystal panel. In this case, the temperature for heating the liquid crystal panel by the means is preferably in the range of 60 to 150 ° C.

  According to the present invention, it is possible to separate a liquid crystal panel for each material, which does not consume a great deal of energy and can be applied to a damaged liquid crystal panel. In addition, it is possible to provide a method for recycling a liquid crystal panel that allows each material to be recycled. The present invention also provides a glass separation / recovery device suitably used in the crushing step in the liquid crystal panel recycling method of the present invention described above. According to such a glass separation and recovery apparatus of the present invention, the panel glass and the polarizing plate of the liquid crystal panel can be safely separated.

It is a flowchart which shows typically a preferable example of the recycling method of the liquid crystal panel of this invention. It is a figure which shows typically the glass separation collection | recovery apparatus used suitably for the crushing process in the recycling method of the liquid crystal panel of this invention, Fig.2 (a) is a perspective view, FIG.2 (b) is a top view, FIG. 2 (c) is a top view showing a state in which the panel glass is crushed. 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 cyclone type | mold separation apparatus 51 used suitably for the specific gravity separation process in this invention, Fig.4 (a) is a schematic top view, FIG.4 (b) is a schematic cross section. It is sectional drawing which shows typically the liquid crystal panel 1 of a typical example.

  FIG. 1 is a flowchart schematically showing a preferred example of a method for recycling a liquid crystal panel according to the present invention. The present invention is a step of crushing a liquid crystal panel in a state where a polarizing plate is attached, and by giving different movement speeds to the panel glass and the polarizing plate constituting the liquid crystal panel, It includes a crushing step for peeling the polarizing plate, and a specific gravity separation step for separating the polarizing plate and the panel glass separated by the crushing step. According to the method for recycling a liquid crystal panel according to the present invention, it is possible to separate the members of the liquid crystal panel for each material, and it is possible to provide a processing method that can be used effectively as a resource.

  The liquid crystal panel recycling method of the present invention includes a conventionally known appropriate structure such as the 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. 5, a duty liquid crystal panel such as a TN (Twisted Nematic) liquid crystal panel or STN (Super Twisted Nematic) liquid crystal panel is also applicable. Is possible. Moreover, a plasma display panel (PDP) and an organic EL panel are also applicable. Hereinafter, with reference to FIG. 1, each step of the method for recycling a liquid crystal panel according to the present invention will be described in detail, taking as an example the case of providing the liquid crystal panel having the structure shown in FIG.

  The liquid crystal panel recycling method of the present invention includes a crushing step (step S4) for crushing a liquid crystal panel with a polarizing plate attached to a waste liquid crystal panel, as in the example shown in FIG. A specific gravity separation step (step S5) for separating the peeled polarizing plate and the panel glass by specific gravity is basically included. Further, as in the example shown in FIG. 1, before the crushing step (step S <b> 4), the glass type selection step (step S <b> 1) for selecting the liquid crystal panel according to the type of panel glass and the liquid crystal panel panel glass are bonded 2 It is preferable to further include a glass substrate separating step (step S2) for separating the glass substrates and a liquid crystal collecting step (step S3) for collecting the exposed liquid crystal. Moreover, it is preferable to further include a panel glass processing step (step S6) for separating and collecting indium from the panel glass after the specific gravity separation step (step S5) as in the example shown in FIG.

  As described above, the procedure is not limited to the procedure shown in FIG. 1, and the order may be changed even if a part is omitted, and other appropriate steps are added as long as the effects of the present invention are not impaired. Although it may be carried out, it is preferably performed according to the procedure shown in FIG. Hereinafter, each step shown in FIG. 1 will be described in detail.

[1] Glass type selection step In the example shown in FIG. 1, first, as a glass type selection step, liquid crystal panels are selected according to the type (type) of the 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, the panel glass of the liquid crystal panel may be sorted by type using a fluorescent X-ray apparatus. In this case, specifically, the liquid crystal panel is directly irradiated 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 panel glass of the liquid crystal 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 liquid crystal 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 the liquid crystal panel, the panel glass can be obtained for each glass product type quickly, reliably and economically. Can be selected automatically. Further, the display of the glass type may be provided in advance on the panel glass of the liquid crystal 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] Glass Substrate Separation Step Next, the bonded glass substrates 2a and 2b are separated into two (step S2). Examples of the separation method include a method of heating the sealing resin body 3 and a method of cutting the peripheral portions of the glass substrates 2a and 2b. When the glass substrates 2a and 2b are separated, the liquid crystal layer 4 sealed in the gap between the glass substrates 2a and 2b is exposed to the surface.

  In the method in which the sealing resin body 3 is heated and separated, the sealing resin body 3 is heated to separate it by reducing the strength of the sealing resin body 3. As described above, the glass substrates 2a and 2b are usually provided with the sealing resin body 3 provided on the opposite side (inner surface side) along the peripheral edge and bonded together. As the sealing resin body 3, an epoxy resin or the like is usually used, and the strength of the sealing resin body 3 can be reduced by heating. The heating temperature of the sealing resin body 3 can be appropriately selected according to the forming material of the sealing resin body 3, and is not particularly limited. For example, in the case of the epoxy resin sealing resin body 3, 300 degreeC or more is desirable and 400 degreeC or more is more desirable. Examples of the heating method include lamp heating, infrared heating, and heat press. By reducing the strength of the sealing resin body 3 by heating, the glass substrates 2a and 2b can be easily separated manually.

  When the glass substrates 2a and 2b are separated by cutting the peripheral portions of the glass substrates 2a and 2b, the glass is cut out one by one by cutting the four sides inside the glass substrates 2a and 2b. You can do it. For cutting the glass substrates 2a and 2b, for example, a glass cutter, a diamond saw, a scriber, or the like can be used.

  At the same time as the separation of the glass substrate, the driver IC connected to the liquid crystal panel is removed. The driver IC is usually connected to the peripheral portion of the liquid crystal panel using a conductive adhesive. As a method of removal, the driver IC is peeled off manually. Since the adhesive force of the conductive adhesive is weak, the connection portion can be easily peeled off by applying an external force. Moreover, a connection part can also be cut | disconnected with a cutter, such as a cutter knife. The removed driver IC can recover the contained metal by performing an appropriate treatment at a non-ferrous smelter or the like. Since the driver IC can be easily removed manually, the driver IC may be removed at any step before the crushing step (step S4). When the glass substrates 2a and 2b are separated by cutting the peripheral portions of the glass substrates 2a and 2b, the driver IC is also removed at the same time.

[3] Liquid Crystal Recovery Step Next, the liquid crystal exposed on the glass substrates 2a and 2b separated as described above is recovered (step S3). The liquid crystal can be recovered, for example, by scraping the surfaces of the glass substrates 2a and 2b using a scraper for recovering liquid crystal. As the scraper for recovering the liquid crystal, a scraper formed of polypropylene rubber, polyethylene rubber or the like that is softer than the alignment film 9 formed on the glass substrates 2a and 2b can be suitably used. Further, by using a rubber squeegee, only the liquid crystal can be recovered without scraping off the alignment film 9.

[4] Crushing Step In the example shown in FIG. 1, in the subsequent crushing step, the liquid crystal panel is crushed and the glass and the polarizing plate are peeled off simultaneously (step S4). When the crushing step is performed after the glass type selection step (step S1) as in the example shown in FIG. 1, each liquid crystal panel using a single type of panel glass selected as described above. To do. Each of the color filter side panel glass and the TFT side panel glass with the polarizing plate (optical film) 5 is crushed.

  In the said crushing process, the difference of a moving speed is given between a polarizing plate and glass, and a polarizing plate and panel glass are peeled. This makes it possible to separate and collect the polarizing plate and the panel glass for each material. In addition, by separating the elastic polarizing plate from the panel glass, the panel glass can be easily pulverized when recycled.

  Here, FIG. 2 is a diagram schematically showing a glass separation / recovery device 21 preferably used in the crushing step in the present invention, FIG. 2 (a) is a perspective view, FIG. 2 (b) is a top view, and FIG. (C) is a top view which shows the state which crushes a panel glass. Thus, the present invention also provides a glass separation and recovery device that can be suitably used in the crushing step in the method for recycling a liquid crystal panel of the present invention.

  As shown in FIG. 2 (b), the glass separation / recovery device 21 of the present invention has a large-diameter projection row 22b formed in the circumferential direction of the surface of one roll 22a, and one of the surfaces of the other roll 23a facing each other. A small-diameter projection row 23c is formed in the circumferential direction so as not to interfere with the large-diameter projection row 22b on the surface of the roll 22a. Further, on the roll 22a, large-diameter projection rows 22b and small-diameter projection rows 22c are alternately arranged in the axial direction, and on the opposite roll 23a, small-diameter projection rows 23c and large-diameter projection rows 23b are alternately arranged in the axial direction. The respective protrusion rows (large-diameter protrusion rows 22b and 23b, small-diameter protrusion rows 22c and 23c) are disposed at intervals that do not interfere with each other. Furthermore, the glass separation and recovery device 21 of the present invention has means (not shown) for giving different peripheral speed differences to the rolls 22a and 23a.

  The glass separation and recovery apparatus 21 of the present invention sandwiches both sides of the liquid crystal panel 24 and gives a difference in moving speed between the panel glass 26 and the polarizing plate 25, thereby peeling the panel glass 26 and the polarizing plate 25 simultaneously with crushing the liquid crystal panel. To do. This mechanism will be described with reference to the schematic diagram of FIG. In FIG. 2C, by rotating the roll 22a and the roll 23a and passing the liquid crystal panel 24 between the roll 22a and the roll 23a, the liquid crystal panel 24 has a large diameter while being wound around the roll 22a and the roll 23a. It is sandwiched between the projection row 22b and the large-diameter projection row 23b and is crushed by a shearing force. Most of the crushed panel glass 26 is attached to the polarizing plate 25 due to the shearing force. Further, since different peripheral speed differences are already given to the roll 22a and the roll 23a, for example, if the roll 23a has a higher peripheral speed than the roll 22a, the large-diameter projection row 22b and the small-diameter projection row on the roll 22a. The moving speed of the panel glass 26 in contact with the large-diameter projection row 23b and the small-diameter projection row 23c on the roll 23a is larger than the moving speed of the polarizing plate 25 in contact with 22c, and adheres to the polarizing plate 25. The panel glass 26 in the state receives a force in the rotating direction of the roll 23a, and the polarizing plate 25 and the panel glass 26 are peeled off. Both the peeled polarizing plate 25 and the panel glass 26 can be collected in a collecting container 27 installed below.

  The process has the effect of efficiently applying large stress to the panel glass and the polarizing plate by simultaneously applying shear stress due to being sandwiched between the protrusion rows and moving speed difference, and separating them in a short time. Can do.

  In the method for recycling the liquid crystal panel of the present invention, the crushing step can be performed a plurality of times using such a glass separation and recovery device 21. At this time, the height, density, width, and inter-roll distance of the large diameter protrusion row and the small diameter protrusion row are set so as not to cut the polarizing plate completely. When the polarizing plate is not cut, the polarizing plate can be taken out in a large size, and the specific gravity separation step (step S5) described later can be omitted.

  The number of rotations of the roll 22a and the roll 23a is preferably within a range of 5 to 100 rpm, and more preferably within a range of 10 to 80 rpm. This is because the processing time tends to be longer when the rotation speed of the roll 22a and the roll 23a is less than 5 rpm, and when the rotation speed of the roll 22a and the roll 23a exceeds 100 rpm, the passing time between the rolls. This is because of a tendency that the stress becomes short and sufficient stress is not applied.

  Further, the peripheral speed difference between the roll 22a and the roll 23a is preferably in the range of 1.5 to 10 times, and more preferably in the range of 2 to 8 times. If a circumferential speed difference exceeding 10 times is provided, the slip between the projection row and the liquid crystal panel becomes remarkable, and there is a possibility that the frictional force is reduced and sufficient stress is not applied. By setting the peripheral speed difference in a range where the frictional force between the protrusion row and the panel glass and between the protrusion row and the polarizing plate is sufficiently large, it is possible to give a difference in moving speed between the panel glass and the polarizing plate, Separation of the polarizing plate and the panel glass can be facilitated.

  In addition, the shape of the protrusion row is not particularly limited, and includes, for example, a chevron protrusion shape, a gear concave-convex shape, etc., and one and the other roll are different so that the frictional force between the panel glass and the polarizing plate can be obtained to the maximum A protruding row shape may be used.

  Moreover, in the crushing process in this invention, you may use the roll without protrusions, such as an unevenness | corrugation, on the surface, without using the glass separation collection | recovery apparatus 21 mentioned above. In this case, since a roll having no projections such as irregularities has no projections on the surface and is difficult to crush, it is preferable to roughly crush the liquid crystal panel in advance. The size of the rough crushing of the liquid crystal panel is preferably 1 to 10 mm. If the size of the rough crushing of the liquid crystal panel is less than 1 mm, the contact area between the roll and the liquid crystal panel may be reduced and slippage may occur and sufficient stress may not be applied. Moreover, when the size of the rough crushing of a liquid crystal panel exceeds 10 mm, since the adhesion area of panel glass and a polarizing plate is large, it exists in the tendency which becomes difficult to peel.

  In the crushing step in the present invention, it is preferable to heat the liquid crystal panel 24. By heating, the adhesive force between the polarizing plate 25 and the panel glass 26 is weakened, and the peeling can be efficiently performed in the crushing step. The polarizing plate is affixed on the panel glass surface using, for example, an acrylic adhesive. By heating the acrylic adhesive to 40 to 150 ° C., it is possible to soften the polarizing plate and weaken the backing force, and further improve the adhesion and frictional force with the projection row on the roll, and the moving speed By efficiently transmitting the difference, the polarizing plate and the panel glass can be easily separated.

  When using the glass separation and recovery apparatus 21 of the present invention described above, the apparatus may further include means (not shown) for heating the liquid crystal panel. As a means for heating, for example, a hot plate can be suitably used. As heating temperature, 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 polarizing plate, the polarizing plate is damaged, and the frictional force between the projection row and the polarizing plate is reduced in the crushing process, so that sufficient stress is not applied.

  After passing through the crushing step, a mixture of the polarizing plate and the crushed panel glass is obtained from the liquid crystal panel. Since the panel glass is peeled off from the polarizing plate and crushed, when eluting indium with hydrochloric acid or the like in the panel glass processing step (step S6) described later, hydrochloric acid is easy to penetrate 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 polarizing plate and the liquid crystal panel glass is separated into the polarizing plate and the panel glass in a specific gravity separation step (step S5) to be described later, collected for each material, and appropriately recycled for each material. Can do.

[5] Specific Gravity Separation Step In the example shown in FIG. 1, in the subsequent specific gravity separation step, the mixture of the polarizing plate and the panel glass obtained in the crushing step (step S4) is separated into the polarizing plate and the panel glass (step S5). ). As for a polarizing plate, a base material consists of a TAC (triacetylcellulose) film etc., and specific gravity is 1.2-1.4. Therefore, since it is small compared with the specific gravity 2.3-2.6 of panel glass, a polarizing plate and panel glass can be isolate | separated by using a specific gravity difference. Specific examples of the specific gravity separation include conventionally known techniques such as cyclone and floating sorting.

  FIG. 3 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 a polarizing plate and a panel glass is poured into water flowing along the table surface on the tilted vibration table 31. In such a method, the light specific gravity particles, that is, the polarizing plate, flow farther in a thin stream, and therefore can be separated from the heavy specific gravity particles, that is, the panel glass. It is also possible to use a method in which heavy specific gravity particles settle in the gaps of the crosspieces by using a Wilfrey table as shown in FIG. 3 in which a plurality of crosspieces 32 are provided in parallel on the vibration table.

  When thin-flow sorting is performed using a Wilfrey table as in the example shown in FIG. 3, the vibration table 31 has a table surface (upper surface) 3 to 3 from the upper side to the lower side as it goes from the right side to the left side in FIG. 3. It is inclined by 5 ° and is configured such that water supplied from above flows downward. Further, the vibration table is provided with a plurality of low bars 32 arranged in the horizontal direction, and for supplying a mixture of the polarizing plate and the panel glass above the right part of the vibration table in FIG. A supply port 33 is provided.

  In the thin flow sorting using such a Wilfrey table, the panel glass of the supplied mixture of the polarizing plate and the panel glass settles into the gap between the bars. The panel glass that has settled in the gap between the crosspieces moves to the left by inertial force because the swinging speed of the left and right of the vibration table 31 moves fast to the left and slowly to the right. On the other hand, the polarizing plate does not settle and rides in a thin stream and flows downward with water. In this manner, the vibration table is separated from the panel glass on the left side of FIG. 3 and the polarizing plate below.

  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. 4 is a diagram showing a cyclonic separation device 41 preferably used in the specific gravity separation step in the present invention, FIG. 4 (a) is a schematic top view, and FIG. 4 (b) is a schematic cross-sectional view. . As shown in FIG. 4, the airflow including the mixture of the polarizing plate and the panel glass introduced from the powder introduction port 41 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 in the same direction in the center and is discharged from the discharge port 42. 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 42. The polarizing plate having a small specific gravity rises with the air flow and is discharged from the exhaust port 43.

  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 way, the mixture of the polarizing plate and the panel glass obtained in the crushing step (step S4) can be divided into the polarizing plate and the panel glass by a separation method using a specific gravity difference. The separated polarizing plate can be separated and recycled for each material. In addition, the polarizing plate can be recovered by heat. 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.

  As described above, the liquid crystal panel recycling method of the present invention only needs to include at least a crushing step (step S4) and a specific gravity separation step (step S5), and the procedure shown in the flowchart of FIG. The steps shown in FIG. 1 may be partly deleted or replaced, and steps not shown in FIG. 1 may be added as necessary.

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

<Example 1>
The glass separation and recovery apparatus of the present invention having two roll diameters of 63 mm, a large-diameter projection row of 5 mm in height, a width of 3 mm, and a small-diameter projection row of 4 mm in height, 3 mm in width, and a distance between rolls of 0.3 mm is 100 mm × 100 mm. A liquid crystal panel having a panel glass thickness of 0.7 mm and a polarizing plate thickness of 0.2 mm was introduced. The shape of the projection row was a chevron shape. One of the two roll rotational speeds was 6 rpm, and the rotational speed ratio of the other roll was changed by 1, 3, and 5. After crushing, the obtained polarizing plate and panel glass mixture was separated and the glass yield was determined. As a result, they were 60%, 72%, and 88%, respectively.

<Example 2>
In Example 1, since the polarizing plate itself was not cut and could be crushed again, the crushing process was performed for the second time under the same conditions as the first time. After crushing, the obtained polarizing plate and panel glass mixture was separated and the glass yield was determined. As a result, the yields were improved to 65%, 75% and 90%, respectively.

<Example 3>
A liquid crystal panel having the same configuration as that of Example 1, with two rolls rotating at 6 rpm and one rotating at 30 rpm, 100 mm × 100 mm panel glass thickness 0.7 mm, and polarizing plate thickness 0.2 mm Was heated to 80 ° C. and then charged. After crushing, the resulting polarizing plate and panel glass mixture was separated and the glass yield was determined.

  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 Liquid crystal panel, 2a Color filter side panel glass, 2b TFT side panel glass, 3 Seal resin body, 4 Liquid crystal layer, 5 Polarizing plate, 6 Color filter, 7 Antireflection film, 8 Transparent conductive film, 9 Orientation film, 10 pixels Electrode, 11 Bus electrode, 12 Insulating film, 21 Glass separation and recovery device, 22a roll, 22b Large diameter projection row, 22c Small diameter projection row, 23a Roll, 23b Large diameter projection row, 23c Small diameter projection row, 24 Liquid crystal panel, 25 Polarization Plate, 26 Panel glass, 27 Collection container, 31 Vibrating table, 32 Cross, 33 Supply port, 41 Cyclone separation device, 42 Discharge port, 43 Exhaust port.

Claims (7)

A process of crushing a liquid crystal panel with a polarizing plate attached thereto, and by giving different movement speeds to the panel glass and the polarizing plate constituting the liquid crystal panel, Crushing process to peel off,
A method for recycling a liquid crystal panel, comprising a specific gravity separation step of separating a polarizing plate and a panel glass separated by a crushing step.   2. The method for recycling a liquid crystal panel according to claim 1, wherein in the specific gravity separation step, the polarizing plate and the panel glass are separated by specific gravity using a cyclone.   The method for recycling a liquid crystal panel according to claim 1, wherein in the specific gravity separation step, specific gravity separation is performed on the polarizing plate and the panel glass using thin flow sorting. It is an apparatus used for the crushing process in the recycling method of the liquid crystal panel in any one of Claims 1-3,
A pair of two rolls, a large-diameter projection row is formed in the circumferential direction of one roll surface, and the circumferential direction so as not to interfere with the large-diameter projection row of one roll surface on the other opposite roll surface Means for forming a small-diameter projection row on the surface of each of the rolls so that the large-diameter projection row and the small-diameter projection row are staggered and arranged in an axial direction, and further providing a peripheral speed difference between the rolls. A glass separation and recovery device.   The glass separation and recovery device according to claim 4, wherein the peripheral speed difference is in a range of 1.5 to 10 times.   The glass separation and recovery device according to claim 4, further comprising means for heating the liquid crystal panel.   The glass separation and recovery device according to claim 6, wherein a temperature at which the liquid crystal panel is heated by the means is in a range of 60 to 150 ° C.

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