JP2007014832A - Waste liquid crystal panel treatment apparatus, liquid crystal recovery system and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a waste liquid crystal panel treatment apparatus capable of effectively making a resin portion of the waste liquid crystal panel fragile, descending a treatment temperature of reduced pressure heating to a temperature degree at which the liquid crystal is volatilized and efficiently and safely recovering the liquid crystal in a liquid crystal extraction treatment, a liquid crystal recovery system and a method. <P>SOLUTION: A supercritical fluid is produced by feeding a substance for producing a supercritical fluid into a chamber 21 in the state that the waste liquid crystal panel 10 is arranged in the chamber 21 as a reaction vessel and pressurizing and heating it. A seal resin portion of the waste liquid crystal panel 10 is made fragile (destroyed) by production of the supercritical fluid. Further, the liquid crystal vaporized (extracted) from the waste liquid crystal panel in which the seal resin portion is made fragile is recovered by a recovery apparatus 24, i.e., an agglomerating means. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a liquid crystal recovery system and a method thereof, and more particularly, a liquid crystal panel discarded in a liquid crystal panel manufacturing factory or the like, and a reduced pressure from a liquid crystal panel used in a video display device or an information display device discarded in the market. The present invention relates to a waste liquid crystal panel processing apparatus that performs liquid crystal extraction by heating, a liquid crystal recovery system, and a method.

  In recent years, the amount of general waste and industrial waste has been steadily increasing, and the demand for detoxifying waste in order to suppress the increase in these waste and to suppress the deterioration of the environment caused by waste Is growing.

  In order to meet these demands, efforts are being made to reduce the amount of industrial waste discharged from factories and waste of household electrical appliances and information devices that are no longer needed by promoting recycling.

  For example, liquid crystal panels are used in home appliances and information devices, and due to the characteristics of low power drive and space saving, the amount of use is expected to increase rapidly in the future as the advanced information society advances. The

  Generally, this liquid crystal panel is composed of a liquid crystal composed mainly of an organic substance between a pair of glass substrates on which transparent electrodes such as ITO (In-Sn Oxide) are deposited, and then the outer joint surface is epoxy-based. A polarizing plate is adhered to the outer side of the glass substrate, and an organic material such as a color filter is disposed on the inner side.

  For example, in Patent Document 1, a waste liquid crystal panel is placed in a chamber, and the inside of the chamber is decompressed and heated (0 to 40 kPa, 200 to 400 ° C.) to gasify the organic matter constituting the waste liquid crystal panel. The waste liquid crystal panel is placed in the chamber in a state where two glass substrates constituting the panel are crushed. A carrier gas is introduced into the chamber, and the gasified organic matter is discharged out of the chamber. The organic gas discharged out of the chamber is introduced into an organic gas decomposing apparatus and decomposed into inorganic gas and water by this decomposing apparatus. The organic component contained in the decomposed gas of the organic gas is detected by the gas sensor, and when the concentration of the organic component in the gas detected by the gas sensor is equal to or higher than the predetermined value, the decomposed gas is fed back to the organic gas decomposer and re-decomposed. To do.

On the other hand, methods and apparatuses for recovering glass and rare metals from liquid crystal panels have already been proposed. For example, in Patent Document 2, the waste liquid crystal panel is placed in a reaction furnace without being crushed, and the waste liquid crystal panel is heated by depressurizing the inside of the reaction furnace, and the liquid crystal constituting the waste liquid crystal panel and the inner and outer surfaces of the glass substrate are disposed. A processing method and an apparatus for a waste liquid crystal panel that evaporate a part of the arranged solid organic matter and carbonize the remainder of the solid organic matter have been proposed.
JP 2002-23126 A JP 2004230229 A

  However, in Patent Documents 1 and 2, when the waste liquid crystal panel is heated under reduced pressure, it is difficult to raise the temperature because it is in a vacuum state, and it is difficult to heat the treatment panel. In order to extract the liquid crystal from the liquid crystal panel by vacuum heating near vacuum, it is necessary to destroy (weaken) the resin part of the sealing material or sealing material, and the temperature for this is higher than the extraction condition of the liquid crystal. Become. That is, the temperature necessary for volatilizing the liquid crystal under reduced pressure is 150 to 200 ° C., whereas the temperature necessary for weakening the resin portion is 300 ° C. or higher. Must be set above 300 ° C. As a result, when the processing temperature is as high as 300 ° C. or higher, the evaporated liquid crystal may be changed into a harmful substance, which is not suitable for recycling the liquid crystal and is not preferable for safety.

  Therefore, in view of the above problems, the present invention can effectively weaken the resin portion of the waste liquid crystal panel in the liquid crystal extraction process, and can reduce the processing temperature of the reduced pressure heating to the temperature at which the liquid crystal volatilizes. An object of the present invention is to provide a waste liquid crystal panel processing apparatus, a liquid crystal recovery system and a method capable of efficiently and safely recovering liquid crystals.

  The waste liquid crystal panel processing apparatus according to the present invention includes a supply source for supplying a substance for generating a supercritical fluid, a reaction vessel capable of disposing a waste liquid crystal panel therein, and the supply source supplied into the reaction vessel. And a supercritical fluid generating means for generating a supercritical fluid from the substance, wherein the liquid crystal is extracted by weakening the resin portion of the waste liquid crystal panel with the supercritical fluid.

  According to such a configuration of the present invention, in a state where the waste liquid crystal panel is disposed in the reaction vessel, the supercritical fluid is supplied by pressurizing and heating the material for generating the supercritical fluid into the reaction vessel. Generate. Generation of this supercritical fluid weakens (breaks) the sealing resin portion of the waste liquid crystal panel.

  In the apparatus of the present invention, the supercritical fluid generating substance is preferably carbon dioxide, ethylene or nitrous oxide.

  According to such a configuration, carbon dioxide, ethylene, or nitrous oxide is a substance that has a supercritical critical point (temperature, pressure) that is relatively close to normal temperature and normal pressure, and easily generates a supercritical state. . Among these, carbon dioxide is optimal because it is present in normal air, is nonflammable and easy to handle, and can be manufactured at low cost.

  The waste liquid crystal panel processing apparatus according to the present invention includes a supply source for supplying a substance for generating a supercritical fluid, a reaction vessel capable of disposing a waste liquid crystal panel therein, and the supply source supplied into the reaction vessel. Supercritical fluid generating means for generating a supercritical fluid from the substance, and aggregating means for aggregating the liquid crystal extracted from the waste liquid crystal panel, the resin portion of the waste liquid crystal panel is weakened by the supercritical fluid The liquid crystal is extracted.

  According to such a configuration of the present invention, in a state where the waste liquid crystal panel is disposed in the reaction vessel, the supercritical fluid is supplied by pressurizing and heating the material for generating the supercritical fluid into the reaction vessel. Generate. The generation of this supercritical fluid weakens (breaks) the sealing resin portion of the waste liquid crystal panel, and then the liquid crystal extracted from the waste liquid crystal panel is collected by aggregating means.

  The liquid crystal recovery system of the present invention includes a supply source for supplying a material for generating a supercritical fluid, a waste liquid crystal panel that can be disposed therein, a reaction vessel having a means for heating the inside, and an inside of the reaction vessel. Supercritical fluid generating means for generating a supercritical fluid from the substance supplied into the reaction vessel from the supply source by increasing the pressure and temperature, and the waste liquid crystal panel in the reaction vessel Pressure releasing means for releasing the pressure in the reaction vessel in a state placed therein, and reduced pressure heating means for heating the reaction vessel to a predetermined reduced pressure after releasing the pressure in the reaction vessel; Aggregating means for aggregating the liquid crystal extracted from the waste liquid crystal panel by the reduced pressure heating.

  According to such a configuration of the present invention, in a state where the waste liquid crystal panel is disposed in the reaction vessel, the supercritical fluid is supplied by pressurizing and heating the material for generating the supercritical fluid into the reaction vessel. After the generated supercritical fluid is dissolved in the seal resin portion, the pressure in the reaction vessel is released to weaken (break) the seal resin of the waste liquid crystal panel. Thereafter, the liquid crystal is vaporized and extracted from the waste liquid crystal panel by performing a heat treatment under reduced pressure, and the vaporized liquid crystal can be collected by the aggregating means. A series of these operations can be performed automatically. Therefore, the resin part of the waste liquid crystal panel can be effectively weakened, and the processing temperature of the reduced pressure heating can be lowered to the temperature at which the liquid crystal is volatilized. It becomes possible to collect.

  In the apparatus of the present invention, before performing the heating under reduced pressure in the reaction vessel, the apparatus has second pressure release means for releasing the pressure of the supercritical fluid in the reaction vessel to normal pressure, and when the pressure is released, It is preferable to further comprise a recycle system for aggregating and recovering the supercritical fluid generating substance from the supercritical fluid flowing out of the reaction vessel.

  According to such a configuration, the pressure is released by the pressure release means described above, and at the same time, the pressure is released to atmospheric pressure by the second pressure release means. A recycling system that aggregates and recovers substances for generating critical fluids is provided, so that liquid crystals can be recovered from the liquid crystal panel that is the object to be processed, and materials for generating supercritical fluids used to weaken resin parts are also recovered. It becomes possible to do.

  In the liquid crystal recovery method of the present invention, the waste liquid crystal panel is released in a state where the waste liquid crystal panel is placed in a supercritical fluid generated by pressurizing and heating in the reaction container. The liquid crystal is extracted and recovered by heating under reduced pressure.

  The liquid crystal recovery method of the present invention includes a step of supplying a substance for generating a supercritical fluid to a reaction vessel having heating means and a waste liquid crystal panel disposed therein, and increasing the pressure and temperature inside the reaction vessel. A supercritical fluid generating step for generating a supercritical fluid of the substance, and a pressure for releasing the pressure in the reaction vessel in a state where the waste liquid crystal panel is placed in the supercritical fluid in the reaction vessel. An opening step, a pressure reducing heating step in which the inside of the reaction vessel is heated to a predetermined reduced pressure after releasing the pressure in the reaction vessel, and an aggregation for aggregating liquid crystals extracted from the waste liquid crystal panel by the reduced pressure heating step A process.

  According to such a method of the present invention, a supercritical fluid is produced by supplying a substance for generating a supercritical fluid into the reaction vessel, pressurizing and heating the waste liquid crystal panel in the reaction vessel. After the generated supercritical fluid is dissolved in the seal resin portion, the pressure in the reaction vessel is released to weaken (break) the seal resin of the waste liquid crystal panel. Thereafter, the liquid crystal is vaporized and extracted from the waste liquid crystal panel by performing a heat treatment under reduced pressure, and the vaporized liquid crystal can be collected by the aggregating means. Therefore, the resin part of the waste liquid crystal panel can be effectively weakened, and the processing temperature of the reduced pressure heating can be lowered to the temperature at which the liquid crystal is volatilized. It becomes possible to collect.

Embodiments of the invention will be described with reference to the drawings.
Before describing the embodiment of the present invention with reference to FIG. 1 and FIG. 2, first, the structure of a general waste liquid crystal panel in which liquid crystal is recovered according to the present embodiment will be described with reference to FIG. 3 and FIG. 4. To do.

  FIG. 5 is a longitudinal sectional view schematically showing a general waste liquid crystal panel. The waste liquid crystal panel 10 is discharged from a liquid crystal panel manufacturing factory or taken out of an information display device or a video display device that has been used in the market. In addition, the waste liquid crystal panel 10 described here is one in which polarizing plates 2 and 2 are provided on the outer surfaces of two glass substrates 1a and 1b, respectively. A waste liquid crystal panel 10 shown in FIG. 5 is an active liquid crystal panel such as a TFT liquid crystal panel. However, the same processing can be performed with a passive liquid crystal panel. The waste liquid crystal panel 10 has two glass substrates 1a and 1b arranged to face each other at a predetermined interval. These glass substrates 1a and 1b are bonded between the inner surfaces by a sealing material 7 such as an epoxy resin provided along the peripheral edge portion.

The regions sealed by the glass substrates 1a and 1b and the sealing material 7 are maintained at a predetermined interval by the spacers 8 and are filled with the liquid crystal 9 made of an organic material to form a liquid crystal layer. A polarizing plate 2 is adhered to the outer surface of each glass substrate 1a, 1b with an adhesive material. One glass substrate 1a has a polarizing plate 2 on the outside and a color filter 3, an overcoat 4 on which a transparent conductive film 6 is formed, and an alignment film 5, and the other glass substrate 1b has an outside. The polarizing plate 2 is disposed on the inner side, and the transparent conductive film 6 and the alignment film 5 are disposed on the inner side.
The polarizing plate 2, the color filter 3, and the alignment film 5 are made of a material mainly composed of an organic substance, and the transparent conductive film 6 is made of a film containing indium or the like. Reference numeral 11 in the figure denotes a switch element made of a metal.

  FIG. 6A shows two glass substrates 1a and 1b constituting the main part of the waste liquid crystal panel 10 shown in FIG. 5, and a sealing material for holding the liquid crystal 9 between the glass substrates 1a and 1b. 7 and a sealing material 7b for sealing the sealing portion 7a formed in a part of the sealing material 7. FIG. 6B shows a cross-sectional view taken along line AA of FIG. When the thickness of the glass substrate 1a or 1b is L1 and the distance between the glass substrates 1a and 1b is L2, for example, L1 = 0.5 mm and L2 = 5 to 10 μm.

(First embodiment)
FIG. 1 is a diagram schematically showing a configuration of a liquid crystal recovery system according to a first embodiment of the present invention.
In FIG. 1, a liquid crystal recovery system 20 includes a chamber 21 that is a reaction vessel, a gas cylinder 22 that is a supply source of a substance G for generating a supercritical fluid, a pressurizing pump P1, a check valve V1, and a pressure release. And a recovery device 24, a decompression pump P2, an activated carbon filter 25, and a control device 30.
The chamber 21 has an internal space for storing the waste liquid crystal panel 10 and has a heater 23 as a heating means for heating the internal space. The chamber 21 is configured in a substantially rectangular parallelepiped or cubic box shape, and has a door (not shown) that can be opened and closed and sealed on the front surface. A heat-resistant glass is attached to the door so that the internal space can be observed.

  In the chamber 21, the pressure and temperature of the internal space can be controlled by an external pump or heater, and the supercritical fluid (for example, supercritical carbon dioxide) is generated in the internal space by increasing the pressure and temperature. After being dissolved in the sealing resin of the liquid crystal panel 10, the pressure is released by the valve V2 to weaken (break) the resin, and the liquid crystal 9 is volatilized from the waste liquid crystal panel 10 by heating the internal space under reduced pressure in that state. And function as a reaction vessel for extraction.

A gas cylinder 22 as a supply source stores a substance G for generating a supercritical fluid, for example, carbon dioxide (CO2), and the stored carbon dioxide is pressurized by using a pressurizing pump P1 and a valve V1 and the chamber. 21 can be supplied.
The pressurizing pump P1 and the heater 23 constitute supercritical fluid generating means. The substance G is supplied from the gas cylinder 22 into the chamber 21, and the pressure and temperature inside the chamber 21 are increased to generate a supercritical fluid. .
The heater 23 functions as a heating device that heats the inside of the chamber 21 when supercritical carbon dioxide is generated or heated under reduced pressure.

  The valve V2 weakens (breaks) the sealing resin of the waste liquid crystal panel 10 by releasing the pressure in the chamber 21 while the waste liquid crystal panel 10 is placed in the supercritical fluid in the chamber 21. It functions as a first pressure release means that releases the pressure of the supercritical carbon dioxide in the chamber 21 to normal pressure before performing vacuum heating in the chamber 21.

  The decompression pump P2 and the heater 23 constitute decompression heating means, and after the pressure in the chamber 21 is opened by the valve V2, a decompression heating process is performed in which the interior of the chamber 21 is heated to a predetermined reduced pressure state. At the time of heating under reduced pressure, the pressure in the internal space of the chamber 21 is reduced to 0.01 to 10 kPa, and the liquid crystal volatilization temperature is about 150 ° C.

The recovery device 24 has a cooler and agglomerates the liquid crystal evaporated (extracted) from the waste liquid crystal panel 10 by the reduced pressure heating process. After the pressure is released by the valve V2, the reduced pressure heating is performed using the reduced pressure pump P2. Sometimes, the liquid crystal 9 vaporized and extracted from the waste liquid crystal panel 10 in which the sealing resin is weakened in the chamber 21 functions as an aggregating means for cooling and aggregating and separating and recovering from other gases.
The activated carbon filter 25 has a function of purifying (detoxifying) the residual gas after the liquid crystal is aggregated and separated by the recovery device 24 and discharging it to the atmosphere.

Further, the liquid crystal recovery system 20 receives measurement data from various sensors (not shown) such as temperature and pressure, on / off control of the pressure pump P1 and pressure reduction pump P2, a check valve V1 and pressure release. And a control device 30 for controlling on / off (opening / closing) of the valve V2 and temperature control of the heater 23.
The temperature T and pressure P in the chamber 21 are measured by a thermometer and a pressure gauge (not shown), and the measurement data is input to the control device 30. The control device 30 controls the temperature of the heater 23 and the valve based on the measurement data. The pressure adjustment control of V1 and V2 is performed.

  In the above description, the supercritical state means that when the temperature and pressure of a substance are increased, the boundary line between the liquid and the gas is exceeded above the condition (critical point) that combines the temperature and pressure inherent to the substance. Is a state where the liquid and gas cannot be distinguished from each other. In addition, since the fluid in the supercritical state has a density close to that of a liquid, its dissolving power is several hundred times greater than that of a gas and has a diffusivity close to that of a gas. The permeation into the solute molecules proceeds several hundred times faster than the gas. The carbon dioxide in the supercritical state acts on the sealing material such as the epoxy resin of the waste liquid crystal panel 10 and dissolves in the resin. After that, when the pressure in the chamber 21 is released, the carbon dioxide escapes from the resin and removes the resin. Can be weakened (destroyed).

  As the substance G for generating a supercritical fluid, ethylene or nitrous oxide can be used in addition to carbon dioxide. Regarding carbon dioxide, as shown in FIG. 3, the supercritical critical point (temperature, pressure) of carbon dioxide is 31.1 ° C. and 7.38 MPa, and the region beyond this becomes the supercritical region. In the present invention, the weakening treatment is preferably performed in the supercritical region. However, a subcritical region (not shown) exists on the left side of the supercritical region, and the physical property in the subcritical region is the same as the physical property in the supercritical region. It is an approximation. Therefore, even carbon dioxide in the subcritical region can be dissolved in the resin and weakened (broken). The supercritical critical point of ethylene is 9.2 ° C. and 5.0 MPa, and the supercritical critical point of nitrous oxide is 36.4 ° C. and 7.24 MPa. Of the carbon dioxide, ethylene, and nitrous oxide materials, carbon dioxide is the most appropriate in view of the critical point temperature and pressure. That is, carbon dioxide can be easily changed to a supercritical state because of its low critical point for transition to the supercritical state, and carbon dioxide is present in ordinary air, is nonflammable and easy to handle, and has a low Since it can be manufactured at a low cost, it is adopted as the optimum in this embodiment.

Next, an example of a liquid crystal recovery process using the liquid crystal recovery system of FIG. 1 described above will be described with reference to FIGS.
(1) First, the waste liquid crystal panel 10 is disposed in the internal space of the chamber 21.
(2) Next, the pressure release valve V2 is turned off (closed).
(3) Then, the pressure pump P1 is turned on, the check valve V1 is turned on, and carbon dioxide (CO2) is injected from the gas cylinder 22 into the internal space of the chamber 21 by the pressure pump P1.

  (4) The pressure P in the chamber 21 is measured by a pressure gauge (not shown), and the measurement data is input to the control device 30. When the pressure P in the chamber 21 is equal to or higher than the critical point pressure of carbon dioxide of 7.38 MPa, that is, P ≧ 7.38 MPa, the control device 30 turns off the pressurizing pump P1 and turns off the check valve V1.

(5) Subsequently, the chamber heating heater 23 is turned on to heat the pressurized internal space of the chamber 21.
(6) At that time, the temperature T in the chamber 21 is measured by a thermometer (not shown), and the measurement data is input to the control device 30. The controller 30 turns off the heater 23 when the temperature T in the chamber 21 is 31.1 ° C. or higher, that is, T ≧ 31.1 ° C., which is the critical point of carbon dioxide. The state in the chamber 21 at this time is a supercritical fluid state of carbon dioxide.

(7) Then, a predetermined time (0 to 20 minutes) is waited in the supercritical fluid state generated in (6). This waits for the carbon dioxide in the supercritical fluid state to dissolve in the sealing resin of the waste liquid crystal panel 10.
(8) After a predetermined time, the pressure release valve V2 is turned on (opened), and the inside of the chamber 21 is opened to normal pressure, that is, atmospheric pressure. As a result, carbon dioxide dissolved in the sealing resin of the waste liquid crystal panel 10 escapes, and the sealing material 7 becomes weak (broken). As a result, a through hole 7c is formed in the sealing material 7 as shown in FIG.
(9) Next, the decompression pump P2 is turned on, and the pressure is reduced to a predetermined pressure (0.01 to 10 kPa).

(10) Further, the heater 23 for heating the chamber is turned on to heat the decompressed space of the chamber 21 to a predetermined temperature, for example, 200 ° C. Thereby, the liquid crystal (LC) in the waste liquid crystal panel 10 is vaporized and discharged from the chamber 21 through the through hole 7c of the sealing resin of the waste liquid crystal panel 10 as shown in FIG. The vaporized liquid crystal is recovered by cooling and aggregating through a valve V2 by a recovery device 24 that is an aggregating means. The heating in the reduced pressure state is performed for a predetermined time obtained experimentally.
During this period, at the same time, the gas after the liquid crystal is condensed and separated is cleaned (detoxified) by the activated carbon filter 25 and discharged into the atmosphere.

(11) Then, the decompression pump P2 is turned off, the heater 23 is turned off, and the liquid crystal extraction / recovery is terminated.
(12) Thereafter, the waste panel without liquid crystal is taken out from the chamber 21.

  According to the first embodiment of the present invention, with the waste liquid crystal panel disposed in the reaction vessel, the supercritical fluid is generated by supplying the material for generating the supercritical fluid into the reaction vessel and pressurizing and heating it. After the supercritical fluid is dissolved in the seal resin portion, the pressure in the reaction vessel is released to weaken (break) the seal resin of the waste liquid crystal panel. Thereafter, the liquid crystal is vaporized and extracted from the waste liquid crystal panel by performing a heat treatment under reduced pressure, and the vaporized liquid crystal can be collected by the aggregating means. A series of these operations can be automatically performed under the control of the control device 30. Therefore, the resin part of the waste liquid crystal panel can be effectively weakened, and the processing temperature of the reduced pressure heating can be lowered to the temperature at which the liquid crystal volatilizes, and the liquid crystal can be efficiently and safely changed to a harmful substance. It becomes possible to collect.

(Second Embodiment)
FIG. 7 is a diagram schematically showing the configuration of the liquid crystal recovery system according to the second embodiment of the present invention.
A liquid crystal recovery system 20A shown in FIG. 7 includes the pressure release valve V3 as a second pressure release means, a decompression pump P3, and a liquefaction device 27 in the liquid crystal recovery system of the first embodiment. This is a system with an added recycling system that collects and reuses carbon dioxide.

  That is, when a pressure relief valve V3 is provided by connecting a pipe to the chamber 21, and the supercritical carbon dioxide in the chamber 21 is released to atmospheric pressure by turning on the pressure relief valve V3 and turning on the pressure reducing pump P3. The liquid crystal contained in carbon dioxide diffuses and is recovered (removed) by cooling with the recovery device 26, while the carbon dioxide guided by the release of the atmospheric pressure is liquefied and recovered by applying pressure with the liquefier 27, The gas cylinder 22 is provided with a recycle system for re-storage.

  As in the case of the first embodiment, the control device 30A receives measurement data from various sensors (not shown) such as temperature and pressure, and on / off control of the pressure pump P1 and the pressure reduction pump P2. On-off (open / close) control of the check valve V1 and pressure release valve V2 and temperature control of the heater 23, while on / off (open / close) control of the pressure release valve V3 and on / off control of the decompression pump P3 are performed. It is provided.

  Next, an example of a liquid crystal recovery process using the liquid crystal recovery system of FIG. 7 described above will be described with reference to FIGS. 8 (1) to (12), (8 ′), and (8 ″).

(1) First, the waste liquid crystal panel 10 is disposed in the internal space of the chamber 21.
(2) Next, the pressure release valves V2 and V3 are turned off (closed).
(3) Then, the pressure pump P1 is turned on, the check valve V1 is turned on, and carbon dioxide (CO2) is injected from the gas cylinder 22 into the internal space of the chamber 21 by the pressure pump P1.

(4) The pressure P in the chamber 21 is measured by a pressure gauge (not shown), and the measurement data is input to the control device 30A. The control device 30A turns off the pressurizing pump P1 and turns off the check valve V1 when the pressure P in the chamber 21 is 7.38 MPa or more at the critical point of carbon dioxide, that is, P ≧ 7.38 MPa.
(5) Subsequently, the chamber heating heater 23 is turned on to heat the pressurized internal space of the chamber 21.

(6) At that time, the temperature T in the chamber 21 is measured by a thermometer (not shown), and the measurement data is input to the control device 30A. The controller 30A turns off the heater 23 when the temperature T in the chamber 21 is 31.1 ° C. or higher, that is, T ≧ 31.1 ° C., which is the critical point of carbon dioxide. The state in the chamber 21 at this time is a supercritical fluid state of carbon dioxide.
(7) Then, a predetermined time (0 to 20 minutes) is waited in the supercritical fluid state generated in (6). This waits for the carbon dioxide in the supercritical fluid state to dissolve in the sealing resin of the waste liquid crystal panel 10.

  (8) After a predetermined time, the pressure release valve V3 is turned on (opened), and the inside of the chamber 21 is opened to normal pressure, that is, atmospheric pressure. As a result, carbon dioxide dissolved in the sealing resin of the waste liquid crystal panel 10 escapes, and the sealing material 7 becomes weak (broken). As a result, a through-hole 7c is formed in the sealing material 7 as shown in FIG.

  (8 ') At the same time as the pressure release valve V3 is turned on (opened), the pressure in the chamber 21 is released and the pressure reducing pump P3 is turned on to reduce the pressure to atmospheric pressure at once. The carbon dioxide led by the pressure release and the suction under reduced pressure is led to the liquefaction device 27 to be liquefied and recovered, fed back to the gas cylinder 22 as a supply source, re-stored, and reused (recycled). At this time, if there is liquid crystal dissolved in carbon dioxide, it can be recovered by cooling and aggregating with the recovery device 26.

  (8 ″) After recovering carbon dioxide, the pressure release valve V3 is turned off (closed), and the pressure reducing pump P3 is turned off.

  (9) Next, simultaneously with turning on (opening) the pressure release valve V2, the decompression pump P2 is turned on and the pressure is reduced to a predetermined pressure (0.01 to 10 kPa).

(10) Further, the heater 23 for heating the chamber is turned on to heat the decompressed space of the chamber 21 to a predetermined temperature, for example, 200 ° C. Thereby, the liquid crystal (LC) in the waste liquid crystal panel 10 is vaporized and discharged from the chamber 21 through the through hole 7c of the sealing resin of the waste liquid crystal panel 10 as shown in FIG. The vaporized liquid crystal is recovered by cooling and aggregating through a valve V2 by a recovery device 24 that is an aggregating means. The heating in the reduced pressure state is performed for a predetermined time obtained experimentally.
During this period, at the same time, the gas after the liquid crystal is condensed and separated is cleaned (detoxified) by the activated carbon filter 25 and discharged into the atmosphere.

(11) Then, the decompression pump P2 is turned off, the heater 23 is turned off, and the liquid crystal extraction / recovery is terminated.
(12) Thereafter, the waste panel without liquid crystal is taken out from the chamber 21.
According to the second embodiment of the present invention, the same effect as the first embodiment is obtained, and at the same time the second pressure is released by the first pressure release means in the first embodiment. Since the pressure is released to atmospheric pressure by the opening means, and the supercritical fluid generating substance is agglomerated and collected from the supercritical fluid flowing out from the reaction vessel at that time, it is configured to be reused (recycled). While the liquid crystal can be recovered from the waste liquid crystal panel, which is a waste, it is also possible to recover and reuse the supercritical fluid generating material used to weaken the resin part.

(Third embodiment)
FIG. 9 is a diagram schematically showing a configuration of a liquid crystal recovery system according to the third embodiment of the present invention.
A liquid crystal recovery system 20B shown in FIG. 9 is a system in which a recycling system for recovering and reusing carbon dioxide, which includes a decompression pump P3 and a liquefaction device 27, is added to the liquid crystal recovery system of the first embodiment. It is what.

  That is, a pipe is connected to the chamber 21 and a pressure release valve V3 is provided. The supercritical carbon dioxide in the chamber 21 is released to the atmospheric pressure by turning on the pressure release valve V2 and turning on the decompression pump P3. At this time, carbon dioxide led by the pressure release and vacuum suction is led to the liquefaction device 27 via the recovery device 24 to be liquefied and recovered by applying pressure, and a recycling system is provided for re-reserving in the gas cylinder 22. is there.

  As in the case of the first embodiment, the control device 30B receives measurement data from various sensors (not shown) such as temperature and pressure, and on / off control of the pressure pump P1 and the pressure reduction pump P2. It has a function of performing on / off control of the non-return valve V1 and pressure release valve V2 and temperature control of the heater 23, and on / off control of the decompression pump P3.

  Next, an example of a liquid crystal recovery process using the liquid crystal recovery system of FIG. 9 described above will be described with reference to FIGS. 10 (1) to (12), (8 '), and (8' ').

(1) First, the waste liquid crystal panel 10 is disposed in the internal space of the chamber 21.
(2) Next, the pressure release valve V2 is turned off (closed).
(3) Then, the pressure pump P1 is turned on, the check valve V1 is turned on, and carbon dioxide (CO2) is injected from the gas cylinder 22 into the internal space of the chamber 21 by the pressure pump P1.

(4) The pressure P in the chamber 21 is measured by a pressure gauge (not shown), and the measurement data is input to the control device 30B. The control device 30B turns off the pressurizing pump P1 and turns off the check valve V1 when the pressure P in the chamber 21 is equal to or higher than the pressure 7.38 MPa at the critical point of carbon dioxide, that is, P ≧ 7.38 MPa.
(5) Subsequently, the chamber heating heater 23 is turned on to heat the pressurized internal space of the chamber 21.

(6) At that time, the temperature T in the chamber 21 is measured by a thermometer (not shown), and the measurement data is input to the control device 30B. The control device 30B turns off the heater 23 when the temperature T in the chamber 21 is 31.1 ° C. or higher, ie, T ≧ 31.1 ° C., which is the critical point temperature of carbon dioxide. The state in the chamber 21 at this time is a supercritical fluid state of carbon dioxide.
(7) Then, a predetermined time (0 to 20 minutes) is waited in the supercritical fluid state generated in (6). This waits for the carbon dioxide in the supercritical fluid state to dissolve in the sealing resin of the waste liquid crystal panel 10.

  (8) After a predetermined time, the pressure release valve V2 is turned on (opened), and the inside of the chamber 21 is opened to normal pressure, that is, atmospheric pressure. As a result, carbon dioxide dissolved in the sealing resin of the waste liquid crystal panel 10 escapes, and the sealing material 7 becomes weak (broken). As a result, a through-hole 7c is formed in the sealing material 7 as shown in FIG.

  (8 ') At the same time that the pressure release valve V2 is turned on (opened), the pressure in the chamber 21 is released and the pressure reducing pump P3 is turned on to reduce the pressure to atmospheric pressure at once. The carbon dioxide led by this pressure release and vacuum suction is led to the liquefaction device 27 via the recovery device 24, liquefied and recovered by applying pressure, fed back to the gas cylinder 22 as a supply source, and re-stored. Use (recycle). At this time, if there is liquid crystal dissolved in carbon dioxide, it can be recovered by cooling and aggregating with the recovery device 24.

  (8 ″) After recovering the carbon dioxide, the decompression pump P3 is turned off.

  (9) Next, the decompression pump P2 is turned on and the pressure is reduced to a predetermined pressure (0.01 to 10 kPa).

(10) Further, the heater 23 for heating the chamber is turned on to heat the decompressed space of the chamber 21 to a predetermined temperature, for example, 200 ° C. Thereby, the liquid crystal (LC) in the waste liquid crystal panel 10 is vaporized and discharged from the chamber 21 through the through hole 7c of the sealing resin of the waste liquid crystal panel 10 as shown in FIG. The vaporized liquid crystal is recovered by cooling and aggregating through a valve V2 by a recovery device 24 that is an aggregating means. The heating in the reduced pressure state is performed for a predetermined time obtained experimentally.
During this period, at the same time, the gas after the liquid crystal is condensed and separated is cleaned (detoxified) by the activated carbon filter 25 and discharged into the atmosphere.

(11) Then, the decompression pump P2 is turned off, the heater 23 is turned off, and the liquid crystal extraction / recovery is terminated.
(12) Thereafter, the waste panel without liquid crystal is taken out from the chamber 21.
According to the third embodiment of the present invention, the same effect as the first embodiment is obtained, and at the same time the pressure is released by the first pressure release means in the first embodiment, and at the same time, the reaction vessel The supercritical fluid generation substance is aggregated, recovered, and reused (recycled) from the flowing supercritical fluid, so that liquid crystal can be recovered from the waste liquid crystal panel that is the object to be processed, while the resin part is weakened. It is also possible to recover and reuse the supercritical fluid generating material used in the process.

  In the present invention, for products using liquid crystal panels with or without a sealing port, the liquid crystal can be used as it is without changing to a hazardous material in a state where no harmful substances are generated. It is possible to extract and collect, and it is possible to improve the safety and quality at the time of liquid crystal recovery, or to realize a recovery system with increased safety in detoxifying the liquid crystal.

The figure which shows schematically the structure of the liquid-crystal collection | recovery system of the 1st Embodiment of this invention. Explanatory drawing explaining the sealing resin weakening before liquid crystal collection | recovery, and liquid crystal extraction. The state diagram which shows the critical point of a carbon dioxide. The figure which shows the liquid-crystal collection | recovery process using the liquid-crystal collection | recovery system of 1st Embodiment. The longitudinal cross-sectional view of a general waste liquid crystal panel. The figure which shows a sealing type liquid crystal panel. The figure which shows schematically the structure of the liquid-crystal collection | recovery system of the 2nd Embodiment of this invention. The figure which shows the liquid-crystal collection | recovery process using the liquid-crystal collection | recovery system of 2nd Embodiment. The figure which shows schematically the structure of the liquid-crystal collection | recovery system of the 3rd Embodiment of this invention. The figure which shows the liquid-crystal collection | recovery process using the liquid-crystal collection | recovery system of 3rd Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Waste liquid crystal panel, 20 ... Liquid crystal recovery system, 21 ... Chamber (reaction vessel), 22 ... Gas cylinder, 23 ... Heater (heating means), 24 ... Recovery device (aggregation means), 27 ... Liquefaction device, P1 ... Pressurization Pump, P2 ... decompression pump, V1 ... check valve, V2 ... pressure release valve (first pressure release means), V3 ... pressure release valve (second pressure release means), P3 ... pressure reduction pump.

Claims (10)

A source for supplying a material for generating a supercritical fluid;
A reaction vessel capable of disposing a waste liquid crystal panel inside;
A supercritical fluid generating means for generating a supercritical fluid from the substance supplied into the reaction vessel from the supply source,
A waste liquid crystal panel processing apparatus for extracting liquid crystal by weakening a resin portion of the waste liquid crystal panel with the supercritical fluid.   The waste liquid crystal panel processing apparatus according to claim 1, wherein the supercritical fluid generating substance is carbon dioxide, ethylene, or nitrous oxide. A source for supplying a material for generating a supercritical fluid;
A reaction vessel capable of disposing a waste liquid crystal panel inside;
Supercritical fluid generating means for generating a supercritical fluid from the substance supplied into the reaction vessel from the supply source;
Aggregating means for aggregating the liquid crystal extracted from the waste liquid crystal panel,
A liquid crystal recovery system, wherein the liquid crystal is extracted by weakening a resin portion of the waste liquid crystal panel with the supercritical fluid. A source for supplying a material for generating a supercritical fluid;
A reaction vessel having a means for heating the interior, wherein a waste liquid crystal panel can be disposed inside;
A supercritical fluid generating means for increasing the pressure and temperature inside the reaction container to generate a supercritical fluid from the substance supplied into the reaction container from the supply source;
Pressure release means for releasing the pressure in the reaction vessel in a state where the waste liquid crystal panel is placed in the supercritical fluid in the reaction vessel;
Reduced pressure heating means for heating the reaction container to a predetermined reduced pressure after releasing the pressure in the reaction container;
Aggregating means for aggregating the liquid crystal extracted from the waste liquid crystal panel by the reduced pressure heating;
A liquid crystal recovery system comprising:   5. The liquid crystal recovery system according to claim 3, wherein liquid crystal is extracted by weakening a resin portion of the waste liquid crystal panel with the supercritical fluid.   6. The liquid crystal recovery system according to claim 3, wherein the substance for generating a supercritical fluid is carbon dioxide, ethylene, or nitrous oxide.   Before carrying out the reduced pressure heating in the reaction vessel, it has a second pressure release means for releasing the pressure of the supercritical fluid in the reaction vessel to normal pressure, and when the pressure is released, it flows out of the reaction vessel 7. The liquid crystal recovery system according to claim 4, further comprising a recycle system for aggregating and recovering the supercritical fluid generating substance from the supercritical fluid.   With the waste liquid crystal panel placed in the supercritical fluid generated by pressurizing and heating in the reaction vessel, the pressure in the reaction vessel is released, and the waste liquid crystal panel is heated under reduced pressure to extract the liquid crystal. And collecting the liquid crystal. Supplying a material for generating a supercritical fluid to a reaction vessel having a heating means and having a waste liquid crystal panel disposed therein;
A supercritical fluid generating step of increasing the pressure and temperature inside the reaction vessel to generate a supercritical fluid of the substance;
A pressure release step of releasing the pressure in the reaction vessel in a state where the waste liquid crystal panel is placed in the supercritical fluid in the reaction vessel;
A reduced pressure heating step of heating the reaction vessel to a predetermined reduced pressure after releasing the pressure in the reaction vessel; and
An aggregation step of aggregating the liquid crystal extracted from the waste liquid crystal panel by the reduced pressure heating step;
A liquid crystal recovery method comprising: 10. The liquid crystal recovery method according to claim 8, wherein the liquid crystal is extracted by weakening a resin portion of the waste liquid crystal panel with the supercritical fluid.

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