JP2013071095A - Method for recycling glass having film formed thereon - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for recycling a glass having a film formed thereon by separating the film from the glass without environmental load or without needing an extensive facility.SOLUTION: The glass having a film formed thereon is crushed, and an impact is then given to the crushed glass while mixing aliphatic alcohol thereto, whereby the film of the glass having the firm formed thereon is efficiently separated from the glass.

Description

  The present invention relates to a method for recycling glass on which a film is formed, and more particularly to a method for recycling glass in contact with a highly adhesive material such as a liquid crystal panel or an organic EL.

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

  In response to this situation, the Home Appliance Recycling Law was enforced in Japan in April 2001. Under the Home Appliance Recycling Law, as of February 2011, the recycling of 4 items of 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.

  Recycling of these four home appliances has progressed significantly compared to the beginning of the law enforcement, with the utmost efforts of the people concerned. Currently, recycling of plastics is expanding as well as metals such as iron, copper, and aluminum used in four home appliances. In television, a recycling technique for cutting and recycling CRT (Cathode Ray Tube) glass to remove electron guns and phosphors, and then reusing the original CRT glass as a glass cullet has already been put into practical use.

  On the other hand, liquid crystal displays, plasma displays, organic EL displays, inorganic EL displays, and flat panel displays (hereinafter referred to as FPD) such as FED (Field Emission Display) have been installed in personal products. For example, it has been widely used in various fields such as a television, a personal computer, a monitor, a video, a camera, a mobile phone, a car navigation, an information portable terminal, and a small game machine. The market size of FPD is increasing rapidly with the progress of the advanced information society in recent years due to its power saving, space saving and light weight. Along with this, the amount of disposal of these FPDs is expected to increase year by year, and in environmental activities such as recycling activities, there is an increasing demand for improving recyclability.

  However, these FPDs are relatively new products, and the amount of waste is relatively small at present, and appropriate recycling such as the CRT has not been put into practical use. The current situation is that the discarded FPD is crushed in a waste treatment facility and is landfilled or incinerated with shredder dust.

  A glass substrate is often used as the base material of the FPD display unit. Since glass accounts for most of the product weight, it is desirable to recycle from the viewpoint of improving the recycling rate, and it is more desirable to perform high-level recycling, such as recycling again as a glass raw material for the same product. In addition, a transparent conductive film is processed on the base material, and indium tin oxide (hereinafter referred to as ITO) is mostly used. In recent years, development of FPDs such as liquid crystal and organic EL using indium gallium zinc oxide (Indium Gallium Zinc Oxide: hereinafter referred to as IGZO) for thin film transistors has been advanced. Since transparent conductive films such as ITO and IGZO contain indium which is a rare metal, a recycling method is being sought along with glass. For this reason, research and development have been conducted in various companies and research institutes on the techniques used to recover rare metals such as glass used in FPD and indium contained in FPD.

  For example, Japanese Unexamined Patent Application Publication No. 2009-155717 (Patent Document 1) proposes a method of depositing indium by dissolving and neutralizing an ITO film by subjecting a waste liquid crystal panel to an acid treatment.

  However, in the method using a chemical solution as disclosed in Patent Document 1, a treatment facility such as waste acid and waste alkali is required, and there are many environmental loads such as using a large amount of water for cleaning. In addition, strong acids and strong alkalis are often used, and it is necessary to consider the durability of the treatment facility in addition to work safety, which requires a large capital investment.

  In JP 2010-022966 A (Patent Document 2), the pulverized product of the liquid crystal panel is heated at 850 to 1400 ° C. to sublimate the ITO film, and cooled to 850 ° C. or less to condense and filter. The method of collecting by is disclosed.

  However, in the technique as disclosed in Patent Document 2, an exhaust gas treatment facility is required because a large amount of organic gas is generated by high-temperature treatment of the entire treated product. Moreover, since it is a process at high temperature, there is a problem that energy consumption is large.

JP 2009-155717 A JP 2010-022966 A

  As described above, in the methods of Patent Document 1 and Patent Document 2, enormous energy and large-scale equipment are required to regenerate materials such as glass and indium from waste FPD recovered from the market, and wet processing is also required. Despite the strong desire to develop rare metal recovery by a waste FPD recycling method that does not use a process, an effective dry process recycling method is not yet known.

  In addition, when recovering rare metal from a glass, plastic substrate, or the like on which a rare metal film used for a liquid crystal panel or an organic EL panel is formed by a dry process, the present inventors have a gap between opposing substrates forming the panel. It was found that the inserted liquid crystal material and organic EL material with high adhesiveness play a role of “connecting” to bond the substrate and the rare metal film. For this reason, it is difficult to peel the film from the glass, or the peeled film adheres to the glass piece again due to the adhesiveness of the liquid crystal or the organic EL, thereby efficiently separating the film.

  FIG. 2 is a cross-sectional view schematically showing a typical liquid crystal panel 1. The liquid crystal panel 1 includes two glass substrates (a color filter side glass substrate 2a and a TFT side glass substrate 2b) arranged to face each other. The liquid crystal layer 4 is formed between the opposed substrates.

  Further, a transparent conductive film 8 and an alignment film 9 containing a rare metal such as indium are formed on the inner surface side of the color filter side glass substrate 2a. In addition, a pixel electrode 10, a bus electrode 11, an insulating film 12, a transparent conductive film 8 containing a rare metal such as indium, and an alignment film 9 are formed on the inner surface side of the TFT side glass substrate 2b.

  For example, when the transparent conductive film formed on the glass substrate shown in FIG. 2 is peeled from the glass substrate, an adhesive liquid crystal material adheres between the opposing glass substrate and the transparent conductive film. It played the role of "tethering" to adhere the transparent conductive film and glass, hindering peeling or separation, and reducing the recovery rate of rare metals and glass.

  The present invention has been made in view of the above-mentioned problems, and its object is to provide a method for separating a film formed on glass from glass without imposing an environmental burden and without requiring extensive facilities. That is.

  The method of separating and recycling a glass film on which a film according to the present invention is formed includes a crushing step of crushing the glass on which the film is formed, and an impact on the crushed glass. And an exfoliation step for exfoliating the exfoliated material, and in the exfoliation step, aliphatic alcohol is mixed with the crushed glass.

  Moreover, it is preferable to peel in a peeling process by throwing the glass in which the film | membrane was formed into the container comprised so that it might rotate, and rotating a container.

  Moreover, it is preferable that a peeling process is performed in an aliphatic alcohol atmosphere.

  According to the present invention, the film formed on the glass can be separated from the glass without applying an environmental load and without requiring a large-scale facility.

It is a flowchart which shows the concept of the recycling method of the glass of this invention. It is sectional drawing which shows typically the liquid crystal panel 1 of a typical example with which the glass recycling method of this invention is provided. It is sectional drawing of the TFT element in which the transparent oxide semiconductor provided for the recycling method of the glass of this invention was formed. It is a flowchart which shows an example at the time of applying the glass recycling method of this invention to the liquid crystal panel 1 shown in FIG. It is a perspective view which shows schematic structure of the peeling apparatus 51 used suitably in the peeling process of this invention. It is an experimental result figure which shows the indium density | concentration and recovery rate which compared the glass recycling method of this invention.

  FIG. 1 is a flowchart showing the concept of the glass recycling method of the present invention. As shown in FIG. 1, the glass recycling method of the present invention includes a crushing step for crushing a glass on which a film is formed, a peeling step for peeling the film from the glass, and a processed product obtained by the peeling step. It basically includes a separation material separation step for separating glass and a separation material. In the glass recycling method of the present invention, when the thickness of the glass (glass thickness) is T, it is separated as 0.7 or less times the glass thickness by classification at 0.7 T in the peeled material separation step. Can be separated into glass as a product exceeding 0.7 times the glass thickness, and useful materials in the peeled material and glass can be effectively used as resources.

  The glass recycling method of the present invention can be suitably applied to the recycling of products having a film formed on the glass, such as FPDs, solar cells, touch panels, and products having structures similar to these. Hereinafter, a liquid crystal panel will be described as an example.

  FIG. 2 is a cross-sectional view schematically showing a typical example of the liquid crystal panel 1 used in the glass recycling method of the present invention. In the present invention, a conventionally known liquid crystal panel having an appropriate structure can be provided without any particular limitation. FIG. 2 shows, as an example, a liquid crystal panel 1 including an active element (not shown) such as a thin film transistor (hereinafter referred to as TFT). In the present invention, TN (Twisted Nematic) is shown. ) Duty liquid crystal panels such as liquid crystal panels and STN (Super Twisted Nematic) liquid crystal panels are also applicable.

  The liquid crystal panel 1 of the example shown in FIG. 2 includes, for example, two glass substrates (a color filter side glass substrate 2a and a TFT side glass substrate 2b) having a thickness of about 0.4 to 1.1 mm arranged to face each other. These glass substrates 2a and 2b are provided with a sealing resin body (seal material) 3 along the peripheral edge on the oppositely arranged side (inner surface side) and bonded together. Further, liquid crystal is sealed in a region sealed by the glass substrates 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. A polarizing plate 5 having a thickness of about 0.2 to 0.4 mm is attached to the opposite side (outer surface side) of each glass substrate 2a, 2b with the 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. 2, 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 glass substrate 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. 2, 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 glass substrate 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 glass substrates 2a and 2b. Thin enough.

  In addition, TFT elements such as liquid crystal panels and organic EL are formed on a substrate using an oxide semiconductor such as IGZO (Indium Gallium Zinc Oxide), IZO (Indium Zinc Oxide), or ITZO (Indium Tin Zinc Oxide). From these TFT elements, rare metals such as indium may be recovered.

  FIG. 3 is a cross-sectional view of an embodiment of a TFT element formed using an oxide semiconductor in a TFT channel formation region. The TFT element of FIG. 3 includes a gate wiring 32, a gate insulating film 33, a channel layer 34 of a TFT element in which an oxide semiconductor such as IGZO is formed on a glass substrate 31, and an insulating film 35. Further, a source wiring 36, a drain electrode 37, and an insulating film 38 are formed on the upper side. The gate wiring 32, the insulating film 33, the source wiring 36, the drain electrode 37, and the insulating film 38 can be formed of a material constituting a general TFT.

The insulating film 38 is provided in the TFT manufacturing process in order to protect damage caused by etching of the channel layer when the source / drain electrodes are formed. However, the insulating film 38 is not necessarily provided.

  In addition, it is possible to recover a rare metal such as indium having a higher concentration from a liquid crystal panel glass or an organic EL glass including a TFT element in which an oxide semiconductor is formed in a channel layer.

  Note that although a bottom gate type TFT is used in FIG. 3, a top gate type TFT may be used, and any structure may be used as long as a transparent oxide semiconductor is formed.

  FIG. 4 is a flowchart showing an example in which the glass recycling method of the present invention is applied to the liquid crystal panel 1 shown in FIG. Hereinafter, the case where the glass recycling method of the present invention is applied to the liquid crystal panel 1 shown in FIG. 2 will be described in detail with reference to FIG.

[1] Liquid Crystal Panel Removal Step In the example shown in FIG. 4, first, a liquid crystal television set discarded from, for example, a home or a manufacturing factory is collected, and the liquid crystal panel is taken out (step S1). Although FIG. 4 shows an example of a liquid crystal television, the present invention is not limited to this. The collected liquid crystal television is disassembled (for example, manually disassembled) by a conventionally known method, and disassembled into metal parts such as shield cases and steel plates, plastic parts such as printed boards, cases and stands, and fluorescent tubes. And take out the LCD panel.

  It should be noted that the liquid crystal panel take-out step can be omitted when using a liquid crystal panel obtained from a production factory or the like.

[2] Glass Type Sorting Step In the example shown in FIG. 4, in the subsequent glass type sorting step, the liquid crystal panel is sorted by glass type (type) (step S2). The composition of glass varies depending on the glass manufacturer, glass type, product number, and the like. Therefore, in order to reuse the collected glass as a material for, for example, a glass substrate, it is necessary to sort a wide variety of glasses by type. Further, even when the collected glass is reused as a material for general glass, for example, it may be required to sort the glass by type to some extent.

  In the glass substrate recycling method of 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, direct irradiation of soft X-rays to the liquid crystal panel using an energy dispersive X-ray fluorescence analyzer can be mentioned. 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 addition, although the case where this glass kind selection process (step S2) is performed before a polarizing plate peeling process (step S3) is illustrated in the flowchart shown in FIG. 4, it is not limited to this order.

  When 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 can be omitted.

[3] Polarizing plate peeling step As shown in FIG. 2, in the case of a liquid crystal panel unit in which a polarizing plate is adhered to the outer surface side of each glass substrate, the polarizing plate is peeled off as in the example shown in FIG. It is preferable to include a polarizing plate peeling step (step S3). In the case of a liquid crystal panel unit having no polarizing plate, this polarizing plate peeling step may be omitted.

  Peeling of the polarizing plate may be performed using subcritical water or by applying stress to the polarizing plate. For example, the separation may be performed by applying a stress such as a commercially available polarizing plate separation device or a crusher, or may be performed manually.

  In addition, when the polarizing plate member may be mixed or when the purpose is not to collect the polarizing plate member, the polarizing plate peeling step can be appropriately omitted.

[4] Panel Disassembly Process In the example shown in FIG. 4, in the subsequent panel disassembly process, the driver IC connected to the liquid crystal panel unit is removed (step S4). The driver IC is usually connected to the peripheral portion of the liquid crystal panel unit using a conductive adhesive. As a removal method, the driver IC is usually 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 in any process until the glass is collected. When the glass substrate is separated by cutting the peripheral edge of the glass substrate, the driver IC is also removed at the same time. The panel disassembly process is not necessarily provided and may be omitted as appropriate.

  Moreover, you may isolate | separate the bonded glass substrate into two sheets in a panel dismantling process. Examples of the separation method include a method of heating the sealing resin body and a method of cutting the peripheral edge of the glass substrate. When the glass substrate is separated, the liquid crystal layer sealed in the gap between the glass substrates is exposed on the surface.

  In the method of separating by heating the sealing resin body, the sealing resin body is heated to reduce the strength of the sealing resin body. As described above, the two glass substrates are usually bonded to each other, with the sealing resin bodies provided on the side (inner surface side) facing each other along the peripheral edge. As the seal resin body, an epoxy resin or the like is usually used, and the strength of the seal resin body can be reduced by heating. The heating temperature of the sealing resin body can be appropriately selected according to the forming material of the sealing resin body, and is not particularly limited. For example, in the case of an epoxy resin sealing resin body, 300 ° C. or higher. Is desirable, and 400 ° C. or higher 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 by heating, the glass substrate can be easily separated manually.

  When the glass substrate is separated by cutting the peripheral edge of the glass substrate, the glass may be cut out one by one by cutting the four sides inside the glass substrate. For cutting the glass substrate, for example, a glass cutter, a diamond saw, a scriber, or the like can be used.

  The panel disassembly process is not necessarily provided and may be omitted as appropriate.

[5] Crushing Step In the example shown in FIG. 4, in the subsequent crushing step, the liquid crystal panel or the separated glass substrate (color filter side glass substrate and TFT side glass substrate) is crushed (step S5).

  The crushing step is performed for each liquid crystal panel or glass substrate that uses the single type of panel glass selected in the glass type selection step (step S2). However, when the glass piece is used for an application that does not need to be divided, the glass substrate can be crushed in a mixed state.

  Various types of commercially available crushers can be used for crushing the glass, and the type of crusher is not particularly limited, but it can be easily crushed with less dust generation, which has an adverse effect on the environment. In view of the low running cost and the like, 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. In addition, a commercially available hammer crusher, roll mill, jaw crusher, or the like can be used.

  The crushing size is preferably crushed so that the size of the glass piece is 100 mm or less. When the size of the glass piece exceeds 100 mm, the movement of the glass piece in the container is limited in the peeling step described later, and the possibility of the glass piece colliding and causing friction is reduced.

[6] Peeling Step In the example shown in FIG. 4, in a subsequent peeling step, a film such as a transparent conductive film is peeled from the glass piece (step S6). Here, FIG. 5 is a perspective view showing a schematic configuration of a peeling apparatus 51 suitably used in the peeling process of the present invention. The peeling device 51 of the example shown in FIG. 5 includes a cylindrical container 52, and the container 52 is configured to rotate around a rotation shaft 53. The peeling device 51 includes a lid 54 for closing an opening for putting the glass piece 55 in the container 52. In FIG. 5, the glass piece 55 and the abrasive grains 56 obtained in the crushing process described above are placed in the container 52. And the lid 54 is fixed. In the peeling step of the glass recycling method of the present invention, it is preferable to peel the film from the glass using a container 52 configured to rotate as shown in FIG.

  In the peeling step, for example, an aliphatic alcohol such as ethanol is mixed in the peeling device 51 shown in FIG. 5 in addition to the glass piece 55 and the abrasive grains 56, and the container 52 is rotated for a predetermined time. In the peeling process, the glass pieces 55, the abrasive grains 56 and the mixed aliphatic alcohol move in the container 52. The transparent conductive film can be peeled from the glass pieces 55 by causing the glass pieces 55 or the glass pieces 55 and the abrasive grains 56 to collide and cause friction.

  Although details will be described in Examples below, the glass peeled off in the peeling step and the transparent conductive film are stuck to each other by a highly adhesive liquid crystal material and are in a state that is difficult to peel or separate easily. . However, by causing the peeling device 51 to operate by mixing an aliphatic alcohol in addition to the glass piece 55 and the abrasive grains 56, the adhesive force of the liquid crystal material that adheres the glass and the transparent conductive film is reduced, and the glass and the transparent conductive film are reduced. Can be easily peeled off.

  In addition, although the case where the peeling apparatus 51 is provided with the cylindrical container 52 was illustrated in FIG. 5, the shape of a container is not limited to this, Polygonal column shape, such as a quadratic prism type and a hexagonal column type But you can.

  Moreover, the magnitude | size of the container 52 in the peeling apparatus 51 should just be what the glass piece 55 enters. The amount of the glass piece 55 put in the container 52 is preferably 30% or less of the volume of the container 52. When a glass piece 55 having an amount exceeding 30% of the volume of the container 52 is placed in the container 52, the movement of the glass piece 55 in the container 52 is limited, so that the number of times the glass piece 55 is rubbed and collided decreases. And the effect which peels a transparent conductive film from the glass piece 55 falls.

  Moreover, in the peeling process using the peeling apparatus 51, it is possible to peel the transparent conductive film from the glass piece 55 even when the abrasive grains 56 are not used, but it is preferable to use the abrasive grains 56. Compared with the case where the glass pieces 55 are rubbed together, the number of contact of the glass pieces 55 is increased by inserting the abrasive grains 56, and the transparent conductive film can be uniformly peeled in a short time.

In the glass recycling method of the present invention, the density of the abrasive grains 56 is preferably 2.0 to 4.0 g / cm ³ . When the density of the abrasive grains is less than 2.0 g / cm ³ , the weight of the abrasive grains is insufficient, so that the effect of peeling the transparent conductive film may be reduced. On the other hand, when the density of the abrasive grains exceeds 4.0 g / cm ³ , the rate at which the glass pieces are crushed increases, so that it may be difficult to separate the exfoliated material from the fine glass powder.

  The abrasive grains 56 may be one type or a combination of a plurality of types. Moreover, it is preferable that the magnitude | size of the abrasive grain 56 is 10-25 mm. When abrasive grains having a size exceeding 25 mm are used, the possibility of crushing the glass pieces increases, so that it may be difficult to separate the exfoliated material from the fine glass powder. On the other hand, when abrasive grains having a size of less than 10 mm are used, the weight of the abrasive grains is insufficient, so that the effect of peeling the transparent conductive film may be reduced.

  The shape of the abrasive grains 56 is preferably spherical, but abrasive grains having a cylindrical shape, a cone shape, a triangular prism shape, a quadrangular prism shape, a rhombus shape, or the like can also be used. Moreover, it is preferable that the input amount of the abrasive grains 56 is 15% or less of the volume of the container 52. When an amount of abrasive grains exceeding 15% of the volume of the container 52 is put in the container, the movement of the glass pieces and the abrasive grains in the container is restricted, so that the peeling effect of the transparent conductive film may be reduced.

  In the glass recycling method of the present invention, the container 52 is preferably rotated at a peripheral speed of 0.6 to 1.0 m / s. When the peripheral speed of a container exceeds 1.0 m / s, there exists a possibility that the frequency | count of contact of a glass piece may reduce because the movement of the glass piece and an abrasive grain in a container is restrict | limited by centrifugal force. Moreover, since the frequency | count of contact with glass pieces or between a glass piece and an abrasive grain reduces when a peripheral speed is less than 0.6 m / s, the effect which peels a transparent conductive film is reduced.

[7] Separation Product Separation Step In the example shown in FIG. 4, in the subsequent separation product separation step, the separation product obtained in the separation step, the glass piece, and the abrasive grains are separated (step S7). The exfoliation exists in a particle size of 0.7 times or less the glass thickness. Therefore, the separated product can be efficiently separated and collected by classifying the processed product obtained in the peeling step with a size of 0.7 times the glass thickness. The classification method is not particularly limited, and a known cyclone method or a vibration sieving classifier can be used. In addition, when using a vibration-type sieving classifier for the classification method, in addition to the sieve having an opening of 0.7 times the glass thickness, the opening of the glass piece obtained in the crushing process is 0.7 times the glass thickness. By using a sieve having a size not larger than the maximum size, the peeled material can be efficiently separated and collected. Moreover, about a glass piece and an abrasive grain, both can be isolate | separated by sieving.

  By removing impurities from the collected exfoliated material, useful materials in the exfoliated material can be recycled as materials again. Further, the glass piece can be used as a raw material for building materials such as bricks and tiles by adjusting to an appropriate particle size.

  Although the liquid crystal panel has been described in the present embodiment, the application target of the glass recycling method in the present invention is not limited to the liquid crystal panel, and the glass on which a film is formed, particularly liquid crystal or organic It can be applied to glass on which a highly adhesive substance such as EL is contained and a film is formed.

  Further, the treatment process is not limited to the flow shown in FIG. 4, and may include a crushing process (Step S <b> 5), a peeling process (Step S <b> 6), and a peeled material separating process (Step S <b> 7).

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

<Example 1>
In this example, the polarizing plate was manually peeled from the liquid crystal panel having an indium concentration of 200 ppm in the liquid crystal panel and a glass thickness of 0.7 mm. Thereafter, the glass substrate was crushed with a hammer to a size of 100 mm or less. After using a peeling device 51 as shown in FIG. 5 provided with a cylindrical container 52 having a volume of 5 L and a diameter of 0.25 m, a glass piece is put in the container 52, and an amount of 15% of the volume of the container 52 is put. Spherical abrasive grains having a diameter of 15 mm and a density of 3.6 g / cm ³ were added in an amount of 10% of the volume of the container 52. Thereafter, 0.15 g of ethanol was added to the container, and the container lid was closed. And this container was rotated for 40 minutes by the peripheral speed of 0.9 m / s centering on the autorotation axis on the temperature conditions of 20 degreeC of room temperature. Thereafter, the peeled material, glass pieces, and abrasive grains were taken out of the container. After removing the abrasive grains manually, the peeled material and the glass piece were classified using a sieve having an opening of 0.5 mm, and the particle size distribution was measured by measuring each mass. After classification, indium was eluted by immersing the peeled pieces and glass pieces of each particle size in 7% hydrochloric acid. Then, the indium concentration in each particle size was examined by measuring the indium concentration in each solution by ICP-AES. Further, the yield of indium was calculated from the mass and concentration. The results are shown in Table 1. The method for calculating the yield of indium can be obtained by dividing the product of the mass ratio (%) and the indium concentration at each particle size by the product of the indium concentration of the entire glass and the mass ratio (%) of the entire glass. As a result, the indium concentration in the glass at a particle size of 0.5 mm or less was 5500 ppm, and the indium yield was 42%. The results are shown in Table 1.

<Example 2>
In this example, the amount of ethanol added was 0.45 g, and the other conditions were the same as in Example 1. As a result, the indium concentration in the glass at a particle size of 0.5 mm or less was 5100 ppm, and the indium yield was 63%. The results are shown in Table 2.

<Example 3>
In this example, the amount of ethanol added was 0.75 g, and the other conditions were the same as in Example 1. As a result, the indium concentration in the glass at a particle size of 0.5 mm or less was 5600 ppm, the indium yield was 76%, and the indium yield exceeded 70%. The results are shown in Table 3.

<Example 4>
In this example, the treatment was performed under the same conditions as in Example 1 except that the amount of ethanol added was 1.5 g. As a result, the indium concentration in the glass at a particle size of 0.5 mm or less was 5000 ppm, the indium yield was 72%, and the indium yield exceeded 70%. The results are shown in Table 4.

<Example 5>
In this example, the treatment was performed under the same conditions as in Example 1 except that the amount of ethanol added was 4.5 g. As a result, the indium concentration in the glass at a particle size of 0.5 mm or less was 5200 ppm, the indium yield was 70%, and the indium yield exceeded 70%. The results are shown in Table 5.

<Example 6>
In this example, the treatment was performed under the same conditions as in Example 1 except that the amount of ethanol added was 6.0 g. As a result, the indium concentration in the glass at a particle size of 0.5 mm or less was 4900 ppm, the indium yield was 72%, and the indium yield exceeded 70%. The results are shown in Table 6.

<Example 7>
In this example, the treatment was performed under the same conditions as in Example 1 except that the amount of ethanol added was 7.5 g. As a result, the indium concentration in the glass at a particle size of 0.5 mm or less was 2700 ppm, and the yield of indium was 39%. The results are shown in Table 7.

<Comparative Example 1>
In Comparative Example 1, the treatment was performed under the same conditions as in Example 1 except that the amount of ethanol added was 0 g. As a result, the indium concentration in the glass at a particle size of 0.5 mm or less was 5100 ppm, and the indium yield was 35%. The results are shown in Table 8.

  It can be seen that the yield of indium is lower than the results obtained in Examples 1 to 7. For this reason, in order to collect rare metals such as indium at a high concentration, it is effective to add an aliphatic alcohol such as ethanol.

<Comparative example 2>
In Comparative Example 2, the treatment was performed under the same conditions as in Example 1 except that the amount of water added was 1.5 g instead of adding ethanol. As a result, the indium concentration in the glass at a particle size of 0.5 mm or less was 5100 ppm, and the indium yield was 58%. The results are shown in Table 9.

  In this comparative example 2, it turns out that the yield of indium is falling compared with Example 4 which added ethanol of the same amount as the addition amount of water. For this reason, in order to collect rare metals such as indium at a high concentration, it is effective to add an aliphatic alcohol such as ethanol.

  Next, FIG. 6 shows experimental results comparing the indium concentration and the recovery rate according to the glass recycling method of the present invention from the above Examples and Comparative Examples. As a result, it can be seen that in order to recover a rare metal such as indium at a high concentration and high yield, it is effective to vaporize the added alcohol such as ethanol in the container 52 and perform the treatment in an alcohol atmosphere. By creating an alcohol atmosphere in the container 52, the adhesive strength of the liquid crystal with high tackiness is reduced, and the glass and the rare metal adhered by the liquid crystal material can be easily peeled off.

  The vapor pressure at which the ethanol added in Example 1 and Example 2 vaporized is lower than the saturated vapor pressure in the container 52.

  On the other hand, the vapor pressure of the vaporized ethanol added in Example 7 exceeded the saturated vapor pressure in the container 52, and the ethanol was not completely vaporized and remained in a liquid state. For this reason, in order to recover rare metals such as indium at a higher concentration and higher yield, the added ethanol is vaporized and the amount of addition in Examples 3 to 6 near the saturated vapor pressure in the container 52 is increased. It is preferred to add ethanol.

  For example, using a peeling device 51 having a container 52 having a volume of 5 L as in the embodiment, a glass piece having a volume of about 15% of the volume of the container 52 is placed in the container 52, and about 10% of the volume of the container 52 is placed. In order to put in a volume of abrasive grains and recover indium at a high concentration and high yield, it is preferable to add 0.75 to 6.0 g of ethanol to recover indium.

  Here, the ratio between the volume of the container and the addition amount of ethanol is obtained by changing the addition amount of an aliphatic alcohol such as ethanol according to the volume when the peeling device 51 including the container 52 having a large volume is used. Similarly, the yield of indium can be improved.

  In the present embodiment, the example in which ethanol is added has been described. However, the type of alcohol is not limited to ethanol, and the same effect can be obtained by adding another alcohol. Moreover, in order to vaporize the added alcohol easily, it is preferable to add aliphatic alcohol with a comparatively low boiling point, such as methanol and 2-propanol, for example.

  For example, L (L) is the space volume after the liquid crystal panel and abrasive grains are put into the container, M (g) is the molecular weight of the aliphatic alcohol, and the addition amount when the aliphatic alcohol added to the container is completely vaporized. In the case of X (g), the optimum upper limit value of the alcohol addition amount is preferably set so as to satisfy the following relational expression.

  This can be calculated from the following equation when the maximum addition amount when the total amount of the aliphatic alcohol added to the container is vaporized under the conditions of 1 atm and temperature T is Xmax (g). . From the relational expression (22.4 × (273 + 20) / 273): L = M: X, Xmax = LM / 24.

  Moreover, it is preferable to set the optimal lower limit of the alcohol addition amount so as to satisfy the following relational expression.

  It can be seen from Example 3 that the lower limit value of the alcohol addition amount is optimally set as a value that is 0.1 times the maximum alcohol addition amount.

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

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, 31 glass substrate, 32 gate wiring, 33 gate insulating film, 34 channel layer, 35 insulating film, 36 source wiring, 37 drain electrode, 38 insulating film, 51 peeling device, 52 container, 53 Rotating shaft, 54 Lid, 55 Glass piece, 56 Abrasive grain

Claims (7)

A method of separating and recycling the film of the glass on which the film is formed,
A crushing step of crushing the glass on which the film is formed;
Including an exfoliation process that impacts the crushed glass and exfoliates the glass and exfoliated material,
In the peeling step, a glass recycling method for forming a film, wherein an aliphatic alcohol is mixed with the crushed glass. 2. The glass recycling method according to claim 1, wherein the glass on which the film is formed is a liquid crystal panel.   3. The film according to claim 1, wherein in the peeling step, the glass formed with a film is put in a container configured to rotate and the container is rotated to peel the film. Recycling method for glass.   The method of recycling glass having a film formed thereon according to any one of claims 1 to 3, wherein the peeling step is performed in an aliphatic alcohol atmosphere. The method for recycling a glass having a film formed thereon according to claim 3, wherein the addition amount X of the aliphatic alcohol in the peeling step satisfies the following conditional expression (1).

(Wherein, X is the amount of alcohol added (g), T is the temperature in the container (° C.), L is the space volume (L) in the container when the liquid crystal panel and abrasive grains are placed in the container, and M is alcohol. (Molecular weight.) The method for recycling a glass having a film formed thereon according to claim 3, wherein the addition amount X of the aliphatic alcohol in the peeling step satisfies the following conditional expression 2.

(Wherein, X is the amount of alcohol added (g), T is the temperature in the container (° C.), L is the space volume (L) in the container when the liquid crystal panel and abrasive grains are placed in the container, and M is alcohol. (Molecular weight.) 7. The glass recycling method according to claim 1, wherein the aliphatic alcohol mixed in the peeling step is ethanol.