JP2002254059A - Material recovery method from liquid crystal display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an easy method to process a waste LCD panel and also a material recovery method from a LCD panel which is suitable for recycle of various components of a LCD panel. SOLUTION: The material recovery method from a LCD panel comprises a substrate split step which splits a pair of substrates into an individual substrate through sending an electric current to the electrodes on the inside surface of the substrates by using an energized electrode while dipping a waste LCD panel in a nonconducting liquid such as water, a liquid crystal separation step which dissolves or disperses a liquid crystal in the liquid by dipping a liquid crystal-adhered substrate in the liquid such as ethanol, and separates the liquid crystal from the substrate, and a resin film separation step which separates a resin film from the substrate by boiling the substrate pasted with a resin film in water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of recovering material from a liquid crystal panel discarded from, for example, a liquid crystal panel manufacturing plant, or a liquid crystal panel used in an information processing apparatus or a video display apparatus discarded in the market. It is about.

[0002]

2. Description of the Related Art In recent years, liquid crystal display devices have been widely used in information processing devices such as personal computers, portable electronic devices such as portable telephones and portable information terminals, and household electric appliances. 3 to 5 are views showing an example of this type of liquid crystal display device, particularly showing an example of a transmission type color liquid crystal panel.
3 is an overall schematic configuration diagram, FIG. 4 is a sectional view taken along line AA in FIG. 3, and FIG. 5 is an enlarged view of a main part in FIG.

As shown in FIG. 3, in this liquid crystal panel 10, polarizing plates 13 and 14 made of a resin film are adhered to the outer surfaces of a pair of substrates 11 and 12 disposed opposite to each other. In addition, as shown in FIG. 4, indium tin oxide (hereinafter, abbreviated as ITO) is provided on the inner surfaces (surfaces facing each other) of each of the pair of substrates 11 and 12.
Transparent electrodes 15 and 16 are formed, and alignment layers 17 and 18 made of a resin such as polyimide are formed thereon. The pair of substrates 11 and 12 is a spacer 1
The substrates 9 and 9 are bonded together with an adhesive 20 therebetween, and a liquid crystal 21 is sealed in a space surrounded by the pair of substrates 11 and 12 and the adhesive 20.

More specifically, as shown in FIG. 5, a pixel electrode (transparent electrode 15) is formed on the inner surface of one of the substrates 11 on which the backlight is disposed, and an alignment layer 17 is formed thereon. ing. On the inner surface of the other substrate 12, a black matrix 22 for shielding light between pixels and R (red), G
(Green) and B (blue) color filters 23
Are formed, and the common electrode (transparent electrode 16) and the alignment layer 18 are formed in this order after being planarized by the overcoat layer 24.

[0005]

By the way, with the expansion of applications of liquid crystal display devices, liquid crystal panels discarded from liquid crystal panel manufacturing factories, and liquid crystals used in electronic devices and electric appliances discarded in the market. Increasing panel waste has become a social issue. However, at present, these waste liquid crystal panels are buried as they are, or only buried after incineration, and it has been difficult to say that sufficient measures are taken from the viewpoint of effective use of resources and lack of disposal sites.

Therefore, as a method of treating a waste liquid crystal panel,
For example, a method has been proposed in which a waste liquid crystal panel is put into a fluidized bed in which a heated solid heat medium is caused to flow to decompose and remove resins such as filters and polarizing plates and collect a glass substrate (Japanese Patent Application Laid-Open No. 2000-2000). -51829). Further, a method has been proposed in which a waste liquid crystal panel is directly sheared and crushed into glass cullet and then decomposed in a high-temperature non-ferrous smelting furnace (see Japanese Patent Application Laid-Open No. 2000-84531). However, in these methods, resins such as polarizing plates and liquid crystals are decomposed, and in the latter technique, a glass substrate is used as a substitute for silica stone. Was not. Also,
These methods use high-temperature processing and require large-scale processing equipment. Therefore, simpler processing methods are required.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is possible to treat a waste liquid crystal panel by a simple method, and at the same time, it is suitable for recycling various constituent materials of the liquid crystal panel. It is an object of the present invention to provide a method for recovering a material from a liquid crystal panel.

[0008]

In order to achieve the above object, a method of recovering material from a liquid crystal panel according to the present invention is characterized in that a liquid crystal is sandwiched between the inner surfaces of a pair of substrates arranged opposite to each other and at least one of the substrates is sandwiched between the substrates. A method for recovering material from a liquid crystal panel having a resin film adhered to an outer surface of a substrate, comprising: a substrate dividing step of dividing a pair of substrates into individual substrates (hereinafter, referred to as an A step); Liquid crystal separation step of separating liquid crystal and substrate from the liquid crystal (herein referred to as B step)
And a resin film separating step of separating the resin film and the substrate from the substrate to which the resin film is attached (hereinafter, referred to as a C step) in this order. Here, the “resin film” refers to, for example, a film used for a polarizing plate, a retardation plate, or the like.

According to the method for recovering material from a liquid crystal panel of the present invention, first, a pair of substrates is divided into two substrates in a substrate dividing step. Here, since the liquid crystal is exposed on the substrate, the liquid crystal and the substrate are separated in the next liquid crystal separation step. Next, the resin film stuck to the substrate with an adhesive or the like can be peeled off from the substrate. Through the above steps, at least the substrate, the liquid crystal, and the resin film can be separated. Therefore, in the case of the material recovery method of the present invention, since the liquid crystal, the substrate, and the resin film can be recovered as a material, these members can be easily recycled.

In the above description, three steps of a substrate dividing step (Step A), a liquid crystal separating step (Step B), and a resin film separating step (Step C) are provided in this order, but the technical scope of the present invention is as follows. It is not always necessary to provide all of these three steps, and it is also possible to provide only two of these steps depending on the member to be preferentially collected and in consideration of easiness of operation.

In this case, the method for recovering materials from a liquid crystal panel according to the present invention includes a substrate dividing step (A step) of dividing a pair of substrates into individual substrates, and separating the liquid crystal and the substrate from the substrate to which the liquid crystal has adhered. And a liquid crystal separation step (step B).

Alternatively, a liquid crystal separation step (step B) for separating the liquid crystal and the substrate from the liquid crystal-attached substrate, and a resin film separation step (step C) for separating the resin film and the substrate from the substrate to which the resin film is attached ) Are provided in this order.

[0013] Alternatively, a substrate dividing step (step A) of dividing a pair of substrates into individual substrates and a resin film separating step (step C) of separating the resin film and the substrate from the substrate to which the resin film is adhered. It is characterized by being provided in this order.

The resin film separating step (step C) does not necessarily have to be performed after the substrate dividing step (step A) or the liquid crystal separating step (step B), but must be performed prior to these two steps. Is also good. That is, the resin film may be peeled first from the state of the liquid crystal panel. Also in this case, similarly to the above, all of the above three steps may be provided, or only two of them may be provided.

In this case, the method for recovering material from a liquid crystal panel according to the present invention comprises a resin film separating step (step C) for separating the resin film and the substrate from the substrate to which the resin film is attached, and The method is characterized in that a substrate dividing step (step A) for dividing the substrate into substrates and a liquid crystal separating step (step B) for separating the liquid crystal and the substrate from the substrate to which the liquid crystal is attached are provided in this order.

Alternatively, a resin film separating step (step C) for separating the resin film and the substrate from the substrate to which the resin film is attached, and a substrate dividing step (step A) for dividing a pair of substrates into individual substrates. It is characterized by being provided in this order.

Alternatively, a resin film separating step (step C) for separating the resin film and the substrate from the substrate to which the resin film is attached, and a liquid crystal separating step (step B) for separating the liquid crystal and the substrate from the substrate having the liquid crystal attached ) Are provided in this order.

In the material recovery method of the present invention described above, since a pair of substrates is divided into individual substrates in the substrate dividing step, the substrate is substantially kept in its original shape even though cracks may occur. It can be recovered as it is. However, if it is not necessary to collect the substrates while keeping the original pattern, instead of dividing a pair of substrates into individual substrates,
The entire pair of substrates may be crushed.

In this case, the method for recovering materials from a liquid crystal panel according to the present invention includes a resin film separating step (step C) for separating the resin film and the substrate from the substrate to which the resin film is attached, and crushing the pair of substrates. And a liquid crystal separation step (step B) for separating the liquid crystal and the substrate piece from the substrate piece to which the liquid crystal has adhered. Features.

Alternatively, a substrate crushing step (A 'step) in which a pair of substrates are crushed to form a plurality of substrate pieces, and a liquid crystal separation step (B step) in which liquid crystal and substrate pieces are separated from the substrate piece to which liquid crystal has adhered. Are provided in this order.

Alternatively, a resin film separating step (C step) for separating the resin film and the substrate from the substrate to which the resin film is attached, and a substrate crushing step (A ′) of crushing a pair of substrates to form a plurality of substrate pieces. Step) are provided in this order.

Further, it is also possible to adopt a procedure in which the substrate piece and the resin film are separated after crushing the pair of substrates together. However, since the resin film and the substrate piece are finely mixed, a separation operation such as specific gravity selection is required thereafter.

In this case, a substrate crushing step (A ′ step) in which a pair of substrates are crushed to form a plurality of substrate pieces, and a liquid crystal separation step (B step) in which liquid crystal and substrate pieces are separated from the substrate pieces to which liquid crystal has adhered ) And a resin film separation step (step C) for separating the resin film and the substrate piece from the resin film to which the substrate piece has adhered.

Alternatively, a substrate crushing step (A ′ step) of crushing a pair of substrates to form a plurality of substrate pieces, and a resin film separating step of separating the resin film and the substrate pieces from the resin film to which the substrate pieces are attached ( C step) in this order.

Next, as an example of specific processing in each step, in the substrate dividing step (step A), the inner surface of a pair of substrates constituting the liquid crystal panel is immersed in a liquid. A pair of substrates can be divided into individual substrates by passing a current through the electrodes provided in the substrate. In this case, it is desirable to use a non-conductive liquid as the liquid.
By applying a current to the electrodes on the inner surface side of the pair of substrates in the non-conductive liquid, an expansion force acts on the inner surface side of the substrates, and a force is applied in a direction in which the peripheral portions of the pair of substrates open outward. Is destroyed, and the pair of substrates can be divided into two substrates. The term "non-conductive liquid" as used herein refers to a liquid that does not have conductivity enough to allow a current to flow sufficiently through the electrodes when a certain voltage is applied to the electrodes in the liquid and to divide the pair of substrates. Say that.

There are two examples of the liquid crystal separation step (step B). First, the liquid crystal is eluted into the solvent by immersing the substrate with the liquid crystal in a solvent capable of dissolving the liquid crystal, and then the liquid crystal and the substrate are separated by separating the solution from the substrate. it can. In another method, the liquid crystal is dispersed in the liquid by immersing the substrate with the liquid crystal in the liquid, and the liquid crystal and the substrate can be separated by separating the liquid in which the liquid crystal is dispersed from the substrate. In both cases, it is preferable to apply ultrasonic waves to the solvent or the liquid or to agitate the liquid when the substrate to which the liquid crystal is attached is immersed in the solvent or the liquid, because the dissolution or dispersion of the liquid crystal is promoted.

Further, by subjecting the solution produced in the liquid crystal separation step or the liquid in which the liquid crystal is dispersed to a distillation operation, the liquid crystal and the solvent or the liquid crystal and the liquid can be further separated. According to this configuration, not only the substrate and the liquid crystal are simply separated, but also the liquid crystal can be collected, so that the liquid crystal can be recycled. Among the constituent materials of the liquid crystal panel, the liquid crystal itself is a considerably expensive material, and is therefore preferable in terms of effective use of resources and cost reduction.

In the resin film separating step (step C), the resin film and the substrate can be separated by boiling the substrate to which the resin film is attached in a liquid. Usually, since the resin film is attached to the substrate with an adhesive or the like, the resin film can be separated from the substrate by boiling in a liquid.

As described above, according to the material recovery method of the present invention,
The waste liquid crystal panel can be processed by a simpler method without using a fluidized bed or a large-scale processing facility unlike a conventional processing method using a shear crusher or a non-ferrous smelting furnace. .

Further, after the inner surface of the substrate is exposed through an optional step, an indium extraction step of dissolving an electrode made of an indium compound such as ITO in a solvent and extracting indium from the solution may be further provided. According to this configuration, indium can be recovered from the indium compound that is a constituent material of the electrode.

[0031]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a flowchart showing an operation procedure of a method for collecting materials from a liquid crystal panel according to the present embodiment. For example, a method of collecting a material from a liquid crystal panel as shown in FIGS. 3 to 5 will be described with reference to this flowchart. Here, the liquid crystal panel to be processed includes driver LSIs for driving and control, FP
A liquid crystal is sealed between a pair of glass substrates, and a resin film such as a polarizing plate or a retardation plate is attached to an outer surface of each of the substrates after removing a mounting component such as C.

[Electro-Crushing in Liquid (Substrate Splitting Step)] A liquid crystal panel is constructed by instantaneously applying a high-voltage current from a pair of energizing electrodes provided at both ends of the liquid crystal panel in a non-conductive liquid. The connecting portion (the portion connected by the adhesive) between the two glass substrates to be broken is broken and divided into two, and the inner surface (the surface to which the transparent electrode, the alignment film, the liquid crystal, etc. are attached)
Exposure of the side facilitates subsequent processing such as liquid crystal recovery and indium recovery (step S in FIG. 1).
1).

More specifically, as shown in FIG. 2, the inside of a container 2 provided with a flat conducting electrode 1 at the bottom is filled with a non-conductive liquid L such as water, oleic acid or kerosene. The liquid crystal panel 10 is fixed upright on the current-carrying electrode 1. On the other hand, a rod-shaped current-carrying electrode 3 that is paired with the current-carrying electrode 1 at the bottom is fixed to the center of the upper part of the liquid crystal panel 10. At this time, the non-conductive liquid L is placed in the container 2 in such an amount that the liquid crystal panel 10 is completely immersed and at least the tip of the rod-shaped energizing electrode 3 is immersed. The electrodes 1 and 3 for energization may be fixed to the liquid crystal panel 10 by any method, but it is necessary that the electrodes 1 and 3 are brought into contact with or close to at least the transparent electrode on the inner surface of the glass substrate.

When a high-voltage DC current (for example, about several tens of kV for a liquid crystal panel of about 5 to 6 inches, several tens of A to 500 A at about 1 μS) is applied to the current-carrying electrodes 1 and 3, the current is increased. 10 flows instantaneously through the transparent electrodes exposed at both ends. At that time, an expansion force acts on the inner surface side of the glass substrate, and a force is applied in a direction in which the peripheral portions of the pair of glass substrates open outward, so that the connection portion fixed with the adhesive is broken, and the two glass substrates are broken. Divided. Note that the polarity of the high voltage applied to the energizing electrodes 1 and 3 may be either positive or negative. In addition, it is desirable to pass current to the transparent electrodes on both glass substrates at the same time, but it is necessary to pass current to at least the transparent electrodes on one of the glass substrates. As for the non-conductive liquid L, it is desirable to use oils (such as oleic acid and kerosene) from which a current hardly escapes from the viewpoint of dividing the liquid crystal panel 10. Considering this, it is desirable to use water.

[Step of recovering liquid crystal from panel (liquid crystal separation step)] Next, the liquid crystal adhering to the liquid crystal panel is eluted into a solvent to separate the liquid crystal from the substrate. The liquid crystal is recovered by performing a distillation operation (step S2 in FIG. 1). Or,
The liquid crystal may be separated from the substrate by dispersing the liquid crystal in the liquid, and then the liquid crystal alone may be separated and recovered from the liquid in which the liquid crystal is dispersed.

More specifically, the liquid crystal panel in which the liquid crystal is exposed by electrofracturing and divided into two parts is immersed in a solvent, and the liquid crystal attached to the liquid crystal panel is eluted in the solvent. Examples of the solvent include pentane, hexane, benzene, hydrocarbons such as toluene, alcohols such as methanol, ethanol, propanol and butanol, ethers such as diethyl ether and diisopropyl ether,
Any solvent having solubility in liquid crystals, such as an organic solvent such as ketones such as acetone, can be used. The solvent is preferably one having a relatively low boiling point so as not to raise the distillation temperature so much, and ethanol is desirable in view of the solubility, properties and cost of the liquid crystal. At this time, dissolution of the liquid crystal in the solvent can be promoted by applying ultrasonic waves or stirring the solvent.

After the solvent from which the liquid crystal has sufficiently eluted is separated from the substrate, the solvent is heated under normal pressure or reduced pressure, and the solvent is distilled off to remove the solvent as the distillate and the liquid crystal as the residue. Can be separated. The liquid crystal separated and recovered by this operation can be reused through post-treatments such as impurity removal and rectification. Alternatively, processing such as decomposition can be performed. On the other hand, the solvent can be reused as it is when recovering the liquid crystal in this step.

Alternatively, when a liquid that hardly dissolves liquid crystal, such as water, is used, the liquid crystal panel that has been exposed to liquid crystal after being divided into two parts by electrocrushing is immersed in water, and the liquid crystal attached to the liquid crystal panel is dispersed in water. Let it. At this time, if the liquid crystal panel is simply immersed in water, a small amount of liquid crystal is dispersed and floats like an oil on the surface of water, and most of the remaining liquid crystal remains on the substrate. Therefore, if ultrasonic treatment or stirring is performed using an ultrasonic cleaner to promote the dispersion of the liquid crystal in water, the liquid crystal is dispersed in water to form an emulsion state and become emulsified. In this way, the liquid crystal is removed from the substrate.

When the above separation method using water is performed,
For the recovery of liquid crystal from a liquid mixture of water and liquid crystal, in addition to the method using distillation, the air separation method that blows air from under the container and selectively floats only the liquid crystal using the difference in wettability is also applied. It is possible. Therefore, ethanol or water is optimal as the liquid used in this step.

Although most of the liquid crystal is recovered in this step, the liquid crystal panel is divided into two in the previous electrocrushing step, and when the non-conductive liquid and the liquid crystal come into contact with each other, depending on the type of the non-conductive liquid. In some cases, the liquid crystal may be eluted or dispersed in the non-conductive liquid. In such a case, the non-conductive liquid may be recovered, and a distillation operation may be performed in the same manner as in this step to recover the liquid crystal from the non-conductive liquid. Thereby, the recovery rate of the liquid crystal can be improved.

[Removing Step of Film from Liquid Crystal-Removed Substrate (Resin Film Separating Step)] A liquid crystal panel having a resin film such as a polarizing plate or a retardation plate adhered to its surface is boiled in a liquid such as water. Thereby, the resin film and the glass substrate are separated (Step S3 in FIG. 1).

The resin film used for the polarizing plate, the retardation plate, etc. is made of polyvinyl alcohol (PVA), triacetyl cellulose (TAC), polycarbonate (PC).
, And one side thereof is coated with an adhesive, and is attached to a glass substrate. Therefore, the glass substrate in a state where the liquid crystal on the inner surface side is removed and the resin film is stuck on the outer surface side is immersed in water, and this is heated to perform a boiling treatment. By this processing, the resin film is peeled off from the glass substrate, and each can be collected.

Further, by adding a surfactant to water used for the boiling treatment, the resin film can be surely peeled off in a shorter time. As this surfactant,
A cationic surfactant such as dodecyl ammonium acetate (DAA), an anionic surfactant such as sodium dodecyl sulfate (SDS), or a nonionic surfactant can be used. As the liquid used for the boiling treatment, in addition to water, an alcohol or a hydrocarbon that can dissolve the adhesive can be used, but water is considered to be the easiest to handle.

[Step of Dissolving ITO from Substrate (Indium Extraction Step)] As described above, IT
A transparent electrode made of an O film is formed, and the ITO film is dissolved using an acid to separate the solution from the glass substrate (Step S4 in FIG. 1). As shown in FIGS. 4 and 5, the transparent electrode is covered with an alignment layer, but the alignment layer can be removed simultaneously with the peeling of the resin film in the [resin film peeling step] of the previous step. There is. In that case, since the transparent electrode is exposed, dissolution starts from the surface of the ITO film. Alternatively, even if the alignment layer is not successfully removed in the resin film peeling step in the previous step, a large number of cracks are generated on the glass substrate in the [electrolyte crushing step]. It is exposed and dissolution starts from this part.

Then, the obtained acidic solution is sampled, and the acidic solution in the ITO is contacted with a cation-exchange-type extractant containing a phosphate group or a mixed solution further added with a hydrophobic organic solvent. Indium can be extracted. This method is disclosed in Japanese Patent Application Laid-Open No. 2000-128531, and the like. Through the above steps, various materials can be collected from the liquid crystal panel.

When this method is applied to the color liquid crystal panel shown in FIG. 5, the glass substrate on the backlight side is almost recovered as a single unit, but the other glass substrate has undergone the above steps. Alone, the color filters and the like still remain on the glass substrate. The amount of color filters etc. is very small and does not pose a major problem in the reuse of glass, but if removal is necessary, polishing,
It can be removed by a method such as chemical treatment.

In the method for recovering materials from a liquid crystal panel according to the present embodiment, the liquid crystal panel can be divided into two substrates by electro-in-liquid crushing. The liquid crystal can be recovered by the above process, the resin film can be peeled off from the substrate in the next boiling treatment, and indium, which is one component of the ITO film, can be recovered by acid treatment and solvent extraction. Therefore, in the present method, since a resin film such as a liquid crystal, a glass substrate, a polarizing plate, and a retardation plate can be collected as a material, these members can be easily recycled. In addition, large-scale processing equipment such as a conventional processing method using a fluidized bed or using a shear crusher or a non-ferrous smelting furnace is not required, and processing can be performed by a simpler method.

The technical scope of the present invention is not limited to the above embodiment, and various changes can be made without departing from the spirit of the present invention. For example, in the above embodiment, the substrate dividing step, the liquid crystal separating step,
Although the four steps of the resin film separation step and the indium extraction step were provided in this order, the technical scope of the present invention does not necessarily have to have all of these four steps, and some of them are appropriately provided. May be used. Further, the resin film separating step does not necessarily have to be performed after the substrate dividing step and the liquid crystal separating step, and may be performed prior to these two steps. Further, in this embodiment, in the substrate dividing step, a pair of substrates is divided into individual substrates by using an electro-crushing method.
Even if cracks may occur, the substrate can be recovered with the prototype kept almost unchanged, but if it is not necessary to recover the substrate with the prototype retained, a mechanical shock etc. may be applied. May be crushed together with the glass substrate. Then, after crushing, the resin film may be separated.

The shape and arrangement of the electrodes in the electrocrushing step, the materials of various solvents (liquids) used in the processing in each step,
The processing conditions and the like are not limited to the above embodiment, and can be appropriately selected. Also, the form of the liquid crystal panel to be processed is shown in FIG.
To color / black and white, transmission type /
Various liquid crystal panels can be processed irrespective of the reflection type, passive matrix type / active matrix type, and the like.

[0050]

EXAMPLES The present inventors tried to actually recover materials from a liquid crystal panel using the method of the above embodiment. We report on the results. First, the notebook computer was disassembled and a liquid crystal display section having a size of about 6 inches was taken out. Further, components for driving and control were removed, and only the liquid crystal panel with the polarizing film attached was taken out.

Next, a container having a disc-shaped copper energizing electrode provided at the bottom is prepared, and a liquid crystal panel is supported on several vinyl wires on the energizing electrode, and is vertically set between the wires. At the same time, the rod-shaped iron current-carrying electrode was fixed almost in contact with the upper end of the liquid crystal panel. Then, the container was filled with water to such an extent that the tip of the rod-shaped electrode was immersed. Then, when a high voltage of about 48 kV was instantaneously applied between the pair of energizing electrodes, the liquid crystal panel was divided into two substrates.

Next, each substrate divided into two by the above-mentioned electro-crushing is immersed in a container filled with ethanol, and the container is subjected to ultrasonic treatment with an ultrasonic cleaner to remove the liquid crystal adhered to each substrate in ethanol. Eluted. Next, after separating the ethanol solution from the substrate, the ethanol solution is heated above the boiling point of ethanol by a reduced-pressure evaporator, and ethanol is distilled out by distillation, while the liquid crystal remains, and the ethanol and the liquid crystal are separated. I was able to. Further, since a small amount of liquid crystal was also eluted in the water used in the electrolysis, water was distilled off by distilling the solution, but the liquid crystal remained, and the liquid crystal could be recovered.

When each of the two divided substrates was immersed in a container filled with water and subjected to ultrasonic treatment with an ultrasonic cleaner, the liquid crystal was dispersed in water to be emulsified and emulsified. A mixed liquid was obtained. After the mixture was separated from the substrate, the mixture was heated to a temperature equal to or higher than the boiling point of water by a reduced-pressure evaporator and distilled. As a result, water was distilled out, while liquid crystals remained, and water and liquid crystals could be separated.

Next, each substrate which had been divided into two by electro-crushing and from which liquid crystal had been recovered with ethanol was placed in a container filled with water, which was heated to boil the water. Then
After about 30 minutes, the polarizing film attached to the substrate was peeled off and separated from the glass substrate, and each could be recovered. In addition, when a surfactant of dodecyl ammonium acetate was added to the boiling water, it was confirmed that the polarizing film was peeled off in about 5 minutes in a shorter time than when no surfactant was added.

[0055]

As described above in detail, according to the method for recovering material from a liquid crystal panel of the present invention, liquid crystal, a resin film such as a substrate, a polarizing plate or a retardation plate can be recovered as a material. This is a preferable method from the viewpoint of recycling these members. In addition, the present method does not require a large-scale treatment facility as in a conventional treatment method using a fluidized bed or a shear crusher or a non-ferrous smelting furnace, and can perform treatment with a simpler method. .

[Brief description of the drawings]

FIG. 1 is a flowchart showing a procedure of an operation of a method for collecting materials from a waste liquid crystal panel according to an embodiment of the present invention.

FIG. 2 is a view showing a state of electro-crushing, which is one step of the material recovery method.

FIG. 3 is a perspective view illustrating an example of a liquid crystal display device (an example of a transmissive color liquid crystal panel).

FIG. 4 is a sectional view taken along the line AA in FIG. 3;

FIG. 5 is an enlarged view of a main part of FIG.

[Explanation of symbols]

 1,3 energizing electrode 2 container 10 liquid crystal panel 11,12 substrate 13,14 polarizing plate 15,16 transparent electrode 21 liquid crystal L non-conductive liquid

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08J 11/08 G02F 1/1333 500 4F301 G02F 1/13 101 B09B 5/00 ZABC 1/1333 500 3/00 ZF term (reference) 2H088 FA07 HA01 HA12 HA14 HA16 HA18 HA28 MA20 2H090 HB08Y JC13 JC19 JC20 LA06 LA09 LA16 4D004 AA22 AA50 CA04 CA07 CA34 CA41 CA44 CA50 CB13 CC12 CC15 4D056 AB07 AC01 AC25 CA39 4D0BF BFA BF31 BF01 BF30 BF01 CA08 CA14 CA32 CA43 CA71

Claims (19)

[Claims] 1. A method for recovering material from a liquid crystal panel in which a liquid crystal is sandwiched between inner surfaces of a pair of substrates arranged opposite to each other and a resin film is attached to an outer surface of at least one of the substrates. A substrate dividing step of dividing the substrate into individual substrates; a liquid crystal separating step of separating the liquid crystal and the substrate from the substrate to which the liquid crystal is attached; and the resin film and the substrate from the substrate to which the resin film is attached. And a resin film separating step of separating the material from the liquid crystal panel in this order. 2. A method for recovering material from a liquid crystal panel in which liquid crystal is sandwiched between inner surfaces of a pair of substrates arranged opposite to each other, comprising: a substrate dividing step of dividing the pair of substrates into individual substrates; A liquid crystal separating step of separating the liquid crystal and the substrate from the substrate to which the liquid crystal is adhered in this order. 3. A method for recovering material from a liquid crystal panel in which a liquid crystal is sandwiched between inner surfaces of a pair of substrates arranged opposite to each other and a resin film is attached to an outer surface of at least one of the substrates. A liquid crystal separation step of separating the liquid crystal and the substrate from the attached substrate; and a resin film separation step of separating the resin film and the substrate from the substrate to which the resin film is attached. Material collection method from liquid crystal panel. 4. A method for recovering material from a liquid crystal panel in which a liquid crystal is sandwiched between inner surfaces of a pair of substrates arranged opposite to each other and a resin film is adhered to an outer surface of at least one of the substrates. A liquid crystal panel comprising: a substrate dividing step of dividing a substrate into individual substrates; and a resin film separating step of separating the resin film and the substrate from the substrate to which the resin film is attached. Material recovery method. 5. A method for recovering material from a liquid crystal panel in which a liquid crystal is sandwiched between inner surfaces of a pair of substrates arranged opposite to each other and a resin film is attached to an outer surface of at least one of the substrates. A resin film separating step of separating the resin film and the substrate from the substrate to which is attached, a substrate dividing step of dividing the pair of substrates into individual substrates, and the liquid crystal and the substrate from the substrate on which the liquid crystal is attached. And a liquid crystal separation step of separating the material from the liquid crystal panel in this order. 6. A method for recovering material from a liquid crystal panel in which a liquid crystal is sandwiched between inner surfaces of a pair of substrates arranged opposite to each other and a resin film is attached to an outer surface of at least one of the substrates. A resin film separating step of separating the resin film and the substrate from the substrate to which is attached, and a substrate dividing step of dividing the pair of substrates into individual substrates in this order. Material recovery method. 7. A method for recovering material from a liquid crystal panel in which a liquid crystal is sandwiched between inner surfaces of a pair of substrates arranged opposite to each other and a resin film is attached to an outer surface of at least one of the substrates, A resin film separating step of separating the resin film and the substrate from the substrate to which the liquid crystal is attached, and a liquid crystal separating step of separating the liquid crystal and the substrate from the substrate to which the liquid crystal is attached. Material collection method from liquid crystal panel. 8. A method for recovering material from a liquid crystal panel in which a liquid crystal is sandwiched between inner surfaces of a pair of substrates arranged opposite to each other and a resin film is attached to an outer surface of at least one of the substrates. A substrate crushing step of crushing the substrate to form a plurality of substrate pieces, a liquid crystal separation step of separating the liquid crystal and the substrate piece from the substrate piece to which the liquid crystal is attached, and a resin film from the resin film to which the substrate piece is attached. A method for recovering materials from a liquid crystal panel, comprising a resin film separating step of separating a film and the substrate piece in this order. 9. A method for recovering material from a liquid crystal panel in which liquid crystal is sandwiched between inner surfaces of a pair of substrates disposed opposite to each other, comprising: a substrate crushing step of crushing the pair of substrates to form a plurality of substrate pieces. And a liquid crystal separation step of separating the liquid crystal and the substrate piece from the substrate piece to which the liquid crystal adheres, in this order. 10. A method for recovering material from a liquid crystal panel in which a liquid crystal is sandwiched between inner surfaces of a pair of substrates arranged opposite to each other and a resin film is attached to an outer surface of at least one of the substrates. A substrate crushing step of crushing the substrate to form a plurality of substrate pieces, and a resin film separation step of separating the resin film and the substrate pieces from the resin film to which the substrate pieces are attached, in this order, To recover materials from liquid crystal panels. 11. A method for recovering material from a liquid crystal panel in which a liquid crystal is sandwiched between inner surfaces of a pair of substrates arranged opposite to each other and a resin film is attached to an outer surface of at least one of the substrates. A resin film separating step of separating the resin film and the substrate from the substrate to which is attached, a substrate crushing step of crushing the pair of substrates to form a plurality of substrate pieces, and A method for recovering material from a liquid crystal panel, comprising a liquid crystal separation step of separating liquid crystal and the substrate piece in this order. 12. In the substrate dividing step, a current is applied to electrodes provided on inner surfaces of a pair of substrates constituting the liquid crystal panel while the liquid crystal panel is immersed in a liquid, so that the pair of substrates is immersed in the liquid. The method for recovering materials from a liquid crystal panel according to any one of claims 1, 2, 4, 5, and 6, wherein the substrate is divided into individual substrates. 13. In the liquid crystal separation step, the liquid crystal is eluted into the solvent by immersing the substrate on which the liquid crystal is attached in a solvent capable of dissolving the liquid crystal, and then, the solution is mixed with the substrate. 3. The liquid crystal and the substrate are separated by separating the liquid crystal from the substrate.
12. The method for recovering materials from a liquid crystal panel according to any one of 3, 5, 7, 8, 9, and 11. 14. In the liquid crystal separating step, the liquid crystal is dispersed in the liquid by immersing the substrate with the liquid crystal in the liquid, and the liquid in which the liquid crystal is dispersed is separated from the substrate. Wherein the liquid crystal and the substrate are separated from each other.
12. The method for recovering materials from a liquid crystal panel according to any one of 8, 9, and 11. 15. The method for recovering materials from a liquid crystal panel according to claim 13, wherein ultrasonic waves are applied to the liquid when the substrate to which the liquid crystal is attached is immersed in the liquid. 16. The method for recovering material from a liquid crystal panel according to claim 13, wherein the liquid is agitated when the substrate to which the liquid crystal is attached is immersed in the liquid. . 17. The liquid crystal separated from the solvent or the liquid by subjecting the solution generated in the liquid crystal separation step or the liquid in which the liquid crystal is dispersed to a distillation operation. 17. The method for recovering a material from a liquid crystal panel according to any one of items 16 to 16. 18. The resin film separating step, wherein the resin film and the substrate are separated by boiling the substrate to which the resin film is attached in a liquid. 4,5,6,7,
12. The method for recovering a material from a liquid crystal panel according to any one of 8, 10, and 11. 19. The method according to claim 1, further comprising an indium extraction step of dissolving the electrode made of an indium compound on the substrate in a solvent and extracting indium from the solution. 3. The method for recovering materials from a liquid crystal panel according to item 1.