TW201529148A - Apparatus and method for recycling polarizing plate manufacturing solution - Google Patents

Abstract

Disclosed is an apparatus and method for recycling a polarizing plate manufacturing solution, which allows simple and effective removal of low-molecular polyvinyl alcohol from a polarizing plate manufacturing solution. The apparatus for recycling a polarizing plate manufacturing solution including boric acid to manufacture a polarizing plate from a polyvinyl alcohol-based film includes a cooling unit configured to receive a part of the manufacturing solution from a treatment bath containing the manufacturing solution and cool the manufacturing solution, a filtering unit configured to filter off particles of a predetermined size or above from the manufacturing solution cooled by the cooling unit, and a heating unit configured to heat the manufacturing solution passing through the filtering unit and discharge the manufacturing solution to the treatment bath.

Description

Apparatus and method for recycling polarizing plate manufacturing solution

The present disclosure relates to a technique for producing an optically functional film, and more particularly to a technique for recovering a manufacturing solution for treating a polyvinyl alcohol when a polarizing plate is produced from a polyvinyl alcohol-based film. Main film.

Korean Patent Application No. 10-2013-0131175 filed on October 31, 2013, and Korean Patent Application No. 10-2014-0149609 filed on October 30, 2014 The present invention is hereby incorporated by reference.

An optically functional film is widely used as part of a display device or a similar device. In particular, a polarizing plate, that is, a polarizing film, plays a role in which light vibrating in all directions allows only one direction of vibration to pass, and thus is widely used in, for example, a display device of a liquid crystal display. Further, if a pair of polarizing plates are placed, it is determined that light is passed or blocked. For this reason, the polarizing plates are used as important parts of various liquid crystal displays such as TVs, monitors, notebook computers, digital cameras, cellular phones, or similar.

The polarizing plate is mainly composed of a polyvinyl alcohol (PVA) as a main film. And the polarizing plate can uniaxially orient the polyvinyl alcohol (PVA) as a main film while dyeing the polyvinyl alcohol (PVA) as a main film by using iodine or a dichroic dye, and then bonding The polyvinyl alcohol is produced as a main film and a protective film such as triacetyl cellulose (TAC).

In the manufacture of such a polarizing plate, the polyvinyl alcohol film can be dyed, crosslinked and extended, and for this purpose, the polyvinyl alcohol film can be immersed in various treatment tanks, for example, dyeing tanks for treatment, Joint groove and extension groove. For example, the polyvinyl alcohol film may be immersed in a dye bath, containing a solution or a similar solution of boric acid (H ₃ BO ₃ ), iodine (I ₂ ), and potassium iodide (KI), and then dyed therefrom. Further, the polyvinyl alcohol film may be immersed in a solution contained in a crosslinking tank containing potassium iodide and boric acid, and then a crosslinking reaction may be initiated therefrom.

As described above, in order to manufacture a polarizing plate, the polyvinyl alcohol film is generally immersed in at least one treatment tank containing a polarizing plate production solution such as boric acid and potassium iodide. However, when the polyvinyl alcohol film is immersed in a manufacturing solution of a treatment tank as described above, low molecular weight polyvinyl alcohol molecules may be released from the polyvinyl alcohol film and present in the production solution. The low molecular weight polyvinyl alcohol molecules can be extracted on a surface of the polyvinyl alcohol film during subsequent cleaning, complementary color or drying procedures, which can result in a poor polarizing plate.

Therefore, a manufacturing solution used to some extent to remove such defective products should be discarded from the treatment tank and replaced with a new manufacturing solution. However, since potassium iodide or boric acid contained in the production solution is relatively expensive, if the production solution is often replaced, the cost for manufacturing a polarizing plate may increase too much.

In order to solve this problem, a technique for recovering potassium iodide from a polarizing plate manufacturing solution has been proposed. However, this uncertainty of high recovery efficiency requires a complex processing procedure and consumes a lot of processing costs. Even if a waste solution processing apparatus is independent of the polarizing plate manufacturing apparatus, a procedure for transporting a wasted solution to the wasted solution processing apparatus should be provided.

The present invention is designed to solve the problems of the prior art, and therefore, the present disclosure is directed to providing an apparatus and method for recovering a polarizing plate manufacturing solution that allows simple and effective removal of low molecules from a polarizing plate manufacturing solution. Polyvinyl alcohol, and a polarizing plate manufacturing processing tank and a polarizing plate manufacturing apparatus contain the same equipment and method.

Other objects and advantages of the present invention will become apparent from the following description and the appended claims. In addition, it is to be understood that the objects and advantages of the present disclosure can be realized by the elements defined in the appended claims or their combinations.

In an aspect of the present disclosure, there is provided an apparatus for recovering a polarizing plate manufacturing solution containing boric acid to produce a polarizing plate from a polyvinyl alcohol-based film, the apparatus comprising: a cooling unit configured to receive from a part of the processing solution containing the manufacturing solution and cooling the manufacturing solution; a filtering unit configured to filter out particles of a predetermined size or more from the manufacturing solution cooled by the cooling unit; and a heating unit Structured to heat the manufacturing solution passing through the filtration unit and discharge the manufacturing solution to the treatment tank.

Preferably, the cooling unit can allow a polyvinyl alcohol molecule And the temperature at which the boric acid cross-linking substance condenses to cool the production solution.

Also preferably, the cooling unit can cool the manufacturing solution at a temperature of 0 ° C to 30 ° C.

At the same time, preferably, the filtering unit filters out the condensed polyvinyl alcohol molecules and the boric acid cross-linking substance.

Also preferably, the filter unit can comprise at least two filters having different filter sizes.

Meanwhile, preferably, the filter unit may include a first filter having a filter size of 10 μm or less and a second filter having a filter size of 5 μm or less, and is configured such that the manufacturing solution sequentially passes through the filter. a first filter and the second filter.

Also preferably, the filter unit can comprise at least two parallel filters having the same filter size and configured to selectively pass the manufacturing solution through one of the at least two filters.

At the same time, preferably, at least one of the cooling unit and the heating unit may have a panel-shaped heat exchanger.

At the same time, preferably, the apparatus may further comprise a temperature control unit configured to receive the manufacturing solution from the processing tank and utilize the heat exchange with the receiving manufacturing solution to control the temperature of the manufacturing solution contained in the processing tank. A predetermined range.

Also preferably, the temperature control unit can be provided in a manufacturing solution circulation path, different from the manufacturing solution circulation path through the cooling unit, the filtration unit, and the heating unit.

At the same time, preferably, the cooling unit, the filtering unit and The manufacturing solution circulation path of the heating unit may have a manufacturing solution circulation amount which is 5% to 20% of a manufacturing solution circulation amount compared to a manufacturing solution circulation path through the temperature control unit.

Also preferably, the apparatus may further comprise a concentration control unit configured to control the concentration of the manufacturing solution contained in the processing tank to a predetermined range.

In another aspect of the present disclosure, there is also provided a processing tank for manufacturing a polarizing plate comprising an apparatus for recovering a polarizing plate manufacturing solution according to the present disclosure.

In another aspect of the present disclosure, there is also provided an apparatus for manufacturing a polarizing plate comprising an apparatus for recovering a polarizing plate manufacturing solution according to the present disclosure.

In another aspect of the present disclosure, there is also provided a method for recovering a polarizing plate manufacturing solution containing boric acid to produce a polarizing plate from a polyvinyl alcohol-based film, the method comprising: self-containing the manufacturing The processing tank of the solution receives a part of the manufacturing solution; cooling the receiving manufacturing solution; filtering out particles of a predetermined size or more from the cooling manufacturing solution; heating the filtering manufacturing solution; and discharging the heated manufacturing solution to the processing tank.

In the viewpoint of the present disclosure, when a polarizing plate is produced by immersing a polyvinyl alcohol film in a production solution containing boric acid, it is possible to simply and efficiently remove the low molecular weight polyvinyl alcohol from the production solution.

Therefore, according to the present disclosure, it is feasible to prevent the low molecular weight polyvinyl alcohol contained in the production solution from deteriorating the quality of the polarizing plate or increasing a defect ratio.

Further, according to the present disclosure, the polarizing plate is recovered and semi-permanently used to manufacture a solution, thereby reducing the cost and procedure required for the polarizing plate manufacturing solution, and particularly reducing the polarizing plate by reducing the amount of the expensive potassium iodide and boric acid used. Manufacturing costs are feasible.

In particular, in the aspect of the present disclosure, since the manufacturing solution in the processing tank of the polarizing plate manufacturing apparatus can be recovered, a polarizing plate is manufactured by immersing a polyvinyl alcohol as a main film in the manufacturing solution of the processing tank. It is also feasible to recover the manufacturing solution at the same time.

Therefore, in the point of view of the present disclosure, it is not necessary to transport a manufacturing solution to another place for recycling, and thus the time and cost for recycling can be reduced.

The drawings illustrate the preferred embodiments of the disclosure and, together with the foregoing disclosure, However, the disclosure does not constitute a limitation of the drawings. In the drawings: FIG. 1 is a block diagram showing the functional architecture of an apparatus for recovering a polarizing plate manufacturing solution according to the present disclosure.

2 is a schematic diagram showing a manufacturing solution recovery apparatus for manufacturing a solution apparatus via the recycled polarizing plate according to an embodiment of the present disclosure.

Fig. 3 is a view schematically showing the degree of condensation of a relatively polyvinyl alcohol molecule with a boric acid cross-linking substance according to the temperature of a polarizing plate production solution.

4 is a view schematically showing an apparatus for recovering a polarizing plate manufacturing solution according to another embodiment of the present disclosure.

FIG. 5 is a schematic diagram showing a recycling process according to another embodiment of the present disclosure. Equipment diagram of a polarizing plate manufacturing solution.

6 is a view schematically showing an apparatus for recovering a polarizing plate manufacturing solution according to another embodiment of the present disclosure.

FIG. 7 is a schematic flow chart illustrating a method for recovering a polarizing plate manufacturing solution according to an embodiment of the present disclosure.

Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Before the description, it should be understood that the terms used in the specification and the appended claims should not be construed as a limitation of the The meaning and concept of the technical point of view of the present disclosure are interpreted.

Therefore, the description herein is for illustrative purposes only, and is not intended to limit the scope of the disclosure, so it should be understood that other equivalents and modifications may be made without departing from the spirit and scope of the disclosure. .

1 is a block diagram showing the functional architecture of an apparatus for recovering a polarizing plate manufacturing solution according to the present disclosure, and FIG. 2 is a schematic diagram showing the manufacturing solution recycling of a device for manufacturing a solution via the recycled polarizing plate according to an embodiment of the present disclosure. Architecture diagram.

Referring to FIGS. 1 and 2 , the apparatus for recovering a polarizing plate manufacturing solution according to the present disclosure includes a cooling unit 110 , a filtering unit 120 , and a heating unit 130 .

The cooling unit 110 receives a portion of the manufacturing solution from a processing tank 10 containing the manufacturing solution. To this end, the cooling unit 110 has There is a cartridge, and the manufacturing solution contained in the processing tank 10 can be supplied to the cooling unit 110 by the cartridge.

Here, the treatment tank 10 means a bath, and a polyvinyl alcohol (PVA)-based film is immersed therein for processing during a polarizing plate manufacturing process. The processing tank 10 can include a wide variety of processing tanks used to fabricate a polarizing plate. Typically, the treatment tank 10 applied according to the apparatus for recovering a polarizing plate manufacturing solution according to the present disclosure may comprise a dyeing tank for dyeing a polyvinyl alcohol film for initiating a cross-linking in the polyvinyl alcohol film. At least one of a crosslinking tank of the reaction and an extending groove for extending the polyvinyl alcohol film. For example, an apparatus for recovering a polarizing plate manufacturing solution according to the present disclosure may be provided to all of the dyeing tank, the crosslinking tank, and the extending tank, or any of the processing tanks 10 therebetween. Even if the dyeing, crosslinking, and stretching procedures are performed in a single processing tank 10, the present disclosure can also be applied to the processing tank 10.

Further, the treatment tank 10 to which the apparatus for recovering a polarizing plate production solution according to the present disclosure is applied may include boric acid as a polarizing plate production solution. While the polyvinyl alcohol film is being stretched, the boric acid can be imparted to a certain degree of strength by a crosslinking reaction. Preferably, the treatment tank 10 may further comprise at least one of potassium iodide and iodine in addition to the boric acid. In particular, the potassium iodide allows the iodide ions in the polyvinyl alcohol film to be uniformly distributed.

After receiving at least a portion of the manufacturing solution from the processing tank 10, the cooling unit 110 cools the receiving manufacturing solution. Here, the cooling means that the manufacturing solution is maintained in a state of being contained in the processing tank 10. Compared to the temperature.

The cooling unit 110 may use cooling water to cool the manufacturing solution, but the disclosure is not limited thereto, and the cooling unit 110 may cool the manufacturing solution in various ways.

Further, the cooling unit 110 may include a panel heat exchanger to cool the manufacturing solution. In this embodiment, the temperature of the manufacturing solution can be lowered in a short time, and the cooling unit 110 can have an unoversized volume. However, the present disclosure is not limited thereto, and the cooling unit 110 may have heat exchangers of various shapes.

Preferably, the cooling unit 110 cools the manufacturing solution to a temperature at which a polyvinyl alcohol molecule and a boric acid cross-linking substance can be coagulated (or gelled). As described above, the production solution in which the polyvinyl alcohol film is immersed may contain a low molecular weight polyvinyl alcohol separated from the polyvinyl alcohol film. Further, the production solution may contain boric acid. Therefore, if the cooling unit 110 cools the manufacturing solution below a predetermined temperature, the polyvinyl alcohol molecules and the boric acid cross-linking substance contained in the manufacturing solution may be gelled to form a coagulum.

The filter unit 120 is located at the rear end of the cooling unit 110 to filter out a predetermined size of particles in the manufacturing solution cooled by the cooling unit 110. To this end, the filter unit 120 may include at least one filter through which particles of a predetermined size or more cannot pass.

Preferably, the filtering unit 120 filters out the condensation of the polyvinyl alcohol molecules with the boric acid crosslinking material. In other words, if the cooling unit 110 cools the manufacturing solution such that a polyvinyl alcohol molecule contained in the manufacturing solution is condensed with a boric acid crosslinking substance, the filtering unit 120 can be filtered out as An impurity particle condenses the cross-linking substance and removes the coagulated cross-linking substance from the manufacturing solution. Therefore, when the production solution passes through the filtration unit 120, the polyvinyl alcohol molecules and the boric acid can be simultaneously removed.

For example, the filter unit can have a filter size of from 0.1 μm to 10 μm. In other words, the filter unit can be configured to filter out a condensed crosslinked material having an average diameter of from 0.1 μm to 10 μm. In another example, the filter unit can also be constructed to have a filter size of 1 μm to 5 μm. For example, the filtration unit can be constructed to have a filtration size of 3 [mu]m to filter out particles of coagulated cross-linking material above 3 [mu]m.

At the same time, the filter unit 120 can be configured to have a predetermined slope with respect to a direction perpendicular to the flow direction of the manufacturing solution. For example, if the manufacturing solution is moved from the left to the right, the filter unit 120 can be structured such that its lower portion is on the left and its upper portion is on the right. In particular, the filter unit 120 of the present disclosure can be configured to filter out a colloid, and because of the pressure, the gel can pass through a filter regardless of its size. Therefore, if the filter unit 120 is inclined as in the present embodiment, a colloidal impurity particle can be moved to the upper or lower portion of the filter unit 120, and thus the colloidal impurity particles can be prevented from passing through the filter.

The heating unit 130 heats the manufacturing solution and discharges the manufacturing solution to the processing tank 10. In other words, the heating unit 130 is located at the rear end of the filtering unit 120, and the polyvinyl alcohol molecule and the boric acid are removed via the filtering unit to a certain degree of the production solution, and then the heating manufacturing solution is supplied to the processing tank 10. Since the manufacturing solution passed through the filtering unit 120 has been cooled by the cooling unit 110, if the heating unit 130 is not heated, it is discharged. Up to the treatment tank 10, the temperature of the production solution contained in the treatment tank 10 is lowered. Further, such a temperature drop causes the polyvinyl alcohol molecules to condense with boric acid in the production solution contained in the treatment tank 10, which deteriorates the quality of the polarizing plate. Therefore, the heating unit 130 can heat the manufacturing solution passing through the cooling unit 110 and the filtering unit 120 before being supplied to the processing tank 10 such that the temperature thereof conforms to the temperature of the manufacturing solution contained in the processing tank 10. Thereby, the manufacturing solution contained in the treatment tank 10 is prevented from being cooled.

Here, the heating unit 130 may include a panel heat exchanger to heat the manufacturing solution. In the present embodiment, the temperature of the manufacturing solution can be raised in a short time, and it can prevent the heating unit 130 from having an excessive volume. However, the present disclosure is not limited thereto, and the heating unit 130 may have heat exchangers of various shapes.

Preferably, in the apparatus for recovering a polarizing plate manufacturing solution according to the present disclosure, the cooling unit 110 may cool the manufacturing solution to a temperature of 0 ° ° C to 30 ° C ° . In the case of a manufacturing solution generally used for the production of a polarizing plate, a significant amount of polyvinyl alcohol and boric acid can be rapidly condensed, that is, concentrated in this temperature range. This will be described in more detail with reference to FIG.

Fig. 3 is a view schematically showing the degree of condensation of relative polyvinyl alcohol molecules and boric acid according to the temperature of the solution for producing a polarizing plate.

Here, the polarizing plate production solution used in FIG. 3 has the composition shown in Table 1 below.

In Table 1, potassium iodide (KI) and boric acid (H ₃ BO ₃ ) are expressed in % by weight based on the entire solution, and polyvinyl alcohol (PVA) and iodine (I ₂ ) are expressed in ppm. In addition, most of the other constituents than those described in Table 1 are water as a solvent.

Referring to Figure 3, it can be seen that if the temperature is lowered, the polyvinyl alcohol molecules and the boric acid are coagulated at 30 ° C at the earliest. Therefore, as in the present embodiment, it is understood that the cooling unit 110 preferably cools the manufacturing solution to a temperature of 0 ° C to 30 ° C.

In particular, in the graph of Fig. 3, it can be found that even if the temperature is lowered, the degree of condensation of polyvinyl alcohol molecules with boric acid gradually increases at a temperature of 30 ° C or lower, but the degree of condensation is at a temperature from 5 ° C to 10 ° C and Not greatly increased, even if the temperature drops. Therefore, in order to ensure effective coagulation of the polyvinyl alcohol molecules with boric acid, the cooling unit 110 can cool the manufacturing solution to a temperature of 5 ° C to 10 ° C. If the temperature of the manufacturing solution lowered by the cooling unit 110 is greater than necessary, the cost and time required to heat the manufacturing solution via the heating unit 130 may increase, and a heat exchange area in the cooling unit 110 may increase. Therefore, if the cooling unit 110 cools the manufacturing solution to a temperature of 5 ° C to 10 ° C as in the present embodiment, the manufacturing solution can be cooled by the maximum condensation efficiency, and at the same time, the cooling and installation space of the cooling unit 110 can be minimized. Time and cost are required.

Preferably, the filter unit 120 can comprise at least two filters having different filter sizes. This will be described in more detail with reference to FIG.

4 is a view schematically showing an apparatus for recovering a polarizing plate manufacturing solution according to another embodiment of the present disclosure. However, the following instructions will focus Any architecture that is different from the architecture of FIG. 2 and that can be applied in the same manner as in FIG. 2 will not be described in detail.

Referring to FIG. 4, the filter unit 120 can include two filters, namely a first filter 121 and a second filter 122. In addition, the first filter 121 and the second filter 122 may be in a serial configuration such that the manufacturing solution can sequentially pass through the first filter 121 and the second filter 122. At this time, the first filter 121 can be constructed using a filter having a relatively low filtration execution efficiency compared to the second filter 122, that is, filtering out relatively large particles.

In particular, the first filter 121 may have a filter size of 10 μm or less, and the second filter 122 may have a filter size of 5 μm or less.

For example, the first filter 121 can have a filter size of 5 μm to 10 μm, and the second filter 122 can have a smaller filter size of 0.1 μm to 5 μm. In more detail, the first filter 121 may have a 10 μm filter size such that at least about 99% of the particles having a size greater than 10 μm are filtered out, and the second filter 122 may have a 5 μm filter size such that At least about 99% of the particles larger than 5 [mu]m are filtered out.

If the particles in the mash solution are filtered through at least two filters arranged in series in this embodiment, it is often possible to prevent the filter from being replaced due to an increase in differential pressure for a short period of time. In other words, if a filter having a small filter size is used first to crosslink the particles contained in the manufacturing solution, especially polyvinyl alcohol and boric acid, to remove the coagulated condensate in the colloidal state, then in the phase The differential pressure at the corresponding filter is It increases in a short time, so the filter should be replaced frequently. However, this will result in increased losses and increased costs. In particular, because of the nature of the colloid, a colloid cannot pass through a filter through pressure independent of the actual size of the colloid, and thus the pressure increase of the colloid through the filter is not good. However, if the manufacturing solution sequentially passes through a filter having a larger filter size and a filter having a smaller filter size as in the present embodiment, the front filter filters out particles having a relatively large size, and The rear filter filters out particles having a relatively small size. This differential pressure that relieves the filter is increased so that the filters are not often replaced.

More preferably, the first filter 121 may have a filter size of 3 μm or less, and the second filter 122 may have a filter size of 1 μm or less. For example, the first filter 121 can have a 3 [mu]m filter size and the second filter 122 can have a smaller filter size of 1 [mu]m. In this example, the manufacturing solution cooled by the cooling unit 110 can sequentially pass through the first and second filters. Further, among the particles contained in the production solution, particles having a size larger than 3 μm may be filtered by the first filter 121, and particles having a size of 1 μm to 3 μm may be filtered by the second filter 122. In embodiments of the present disclosure, polyvinyl alcohol molecules and boric acid coagulum can be filtered and removed more efficiently and safely via the filtration unit 120.

FIG. 5 is a view schematically showing an apparatus for recovering a polarizing plate manufacturing solution according to another embodiment of the present disclosure. However, the following description will focus on an architecture other than that of Figures 2 and 4, and any architecture that can be applied in the same manner as in Figures 2 and 4 will not be described in detail.

Referring to FIG. 5, the filtering unit 120 may include the same Filter at least two filters of size, which are configured in parallel. In other words, in FIG. 5, the first filter 121 and the third filter 123 may have the same filter size and are configured in parallel. Therefore, the manufacturing solution cooled by the cooling unit 110 can be filtered through the first filter 121 or the third filter 123.

In the disclosed architecture, it is feasible to relieve the differential pressure increase of the filter, and it is feasible to prevent the filter unit 120 from stopping its operation even if any filter fails to operate normally. For example, in the architecture of FIG. 5, the manufacturing solution can be filtered through the third filter 123 even if the first filter 121 must be replaced. Therefore, in this example, the operation time of the recycling apparatus according to the present disclosure can be extended.

Meanwhile, in the present embodiment in which at least two filters having the same filter size are arranged in parallel, each filter and another filter may be in a serial configuration. For example, as shown in FIG. 5, the first filter 121 and the third filter 123 arranged in parallel with each other may also be arranged in series with other filters, that is, a second filter 122 and a fourth filter 124. . In this example, the second filter 122 and the fourth filter 124 may have the same filter size, so that the filter path including the first filter 121 and the second filter 122 and the third filter 123 are included. And the filtration path of the fourth filter 124 may have the same filtration execution efficiency. For example, the first filter 121 and the third filter 123 may have a filter size of less than 10 μm, and the second filter 122 and the fourth filter 124 may have a filter size of less than 5 μm.

Further, even though FIG. 5 shows that two filtering paths are provided, the present disclosure is not limited thereto. In other words, for use in accordance with an embodiment of the present disclosure The apparatus for recovering the polarizing plate manufacturing solution may include three or more filtration paths. For example, in addition to the first filter path including the first filter and the second filter and the second filter path including the third filter and the fourth filter, a third filter path may be parallel to the The first filter path and the second filter path are provided. At this time, the third filter path may include a fifth filter having the same filter execution efficiency as the first filter and the third filter, and a filter having the same filter as the second filter and the fourth filter. A sixth filter that performs efficiency.

6 is a view schematically showing an apparatus for recovering a polarizing plate manufacturing solution according to another embodiment of the present disclosure. In Figure 6, the following description will also focus on a different architecture than the previous embodiment architecture.

Referring to FIGS. 1 and 6, the apparatus for recovering a polarizing plate manufacturing solution according to the present disclosure may further include a temperature control unit 140.

The temperature control unit 140 controls the temperature of the manufacturing solution contained in the processing tank 10 within a predetermined range. To this end, the temperature control unit 140 can take a manufacturing solution from the processing tank 10 and perform heat exchange with the receiving manufacturing solution.

In particular, the temperature control unit 140 can take a manufacturing solution and heat the receiving manufacturing solution. If the temperature of the manufacturing solution contained in the treatment tank 10 is lowered from a suitable temperature, the polyvinyl alcohol and the boric acid can be coagulated. However, with the heating of the temperature control unit 140, such condensation in the treatment tank 10 is prevented from being feasible. Further, if an apparatus for recovering a polarizing plate manufacturing solution according to the present disclosure is provided, the manufacturing solution can be cooled by the cooling unit 110. Here, if the internal temperature of the treatment tank 10 is as follows In the present embodiment, controlled by the temperature control unit 140, condensation can be prevented even if the heating unit 130 does not normally perform its heating operation. Therefore, in the present embodiment, the temperature of the manufacturing solution contained in the treatment tank 10 can be controlled more stably and more efficiently.

Preferably, the temperature control unit 140 can control the temperature of the manufacturing solution contained in the processing tank 10 within a range of 25 ° C to 65 ° C.

Meanwhile, preferably, as shown in FIG. 6, the temperature control unit 140 may be provided in a manufacturing solution circulation path, different from the manufacturing solution circulation through the cooling unit 110, the filtration unit 120, and the heating unit 130. path. In other words, the apparatus for recovering a polarizing plate manufacturing solution according to the present disclosure may include a first circulation path C1 passing through the cooling unit 110, the filtration unit 120 and the heating unit 130, and a second circulation passing through the temperature control unit 140. Path C2. In the present architecture, even if the recovery system through the cooling unit 110, the filtration unit 120, and the heating unit 130 is not operated, the temperature drop of the manufacturing solution can be prevented and thus the reaction between boric acid and polyvinyl alcohol can be prevented. Condensation.

Meanwhile, a manufacturing solution circulation path through the temperature control unit 140 is independently formed, and another filtration unit 120 may be further provided under the circulation path. In other words, in the architecture of FIG. 2, the second loop path C2 may be additionally formed independently of the first loop path C1, and the second loop path C2 may include a second filter unit along with the temperature control unit 140. 160. At this time, the second filter unit 160 may filter a predetermined size of particles from the manufacturing solution passing through the second circulation path C2. In the disclosed architecture, since another filtering unit 120 is independent of the first circulation path The filter unit 120 of the diameter C1 is provided to the second circulation path C2, and it is possible to more effectively remove impurities such as deposits or condensates in the production solution.

Here, the circulation amount of the manufacturing solution that passes through the first circulation path C1 of the cooling unit 110, the filtration unit 120, and the heating unit 130 may be a circulation amount of the second circulation path C2 that passes through the temperature control unit 140. 5% to 20%. The temperature of the manufacturing solution contained in the processing tank 10 is controlled according to the circulation amount passing through the second circulation path C2, and the circulation amount of the first circulation path C1 including the cooling unit 110 and the same is increased by more than one predetermined period. At the time of registration, the temperature or concentration of the manufacturing solution contained in the treatment tank 10 can be rapidly changed. However, in the present embodiment, this problem can be prevented.

Meanwhile, in the architecture in which the temperature control unit 140 is located in the second circulation path C2, the inlet of the second circulation path C2 may be provided in the lower portion of the processing tank 10. Here, the inlet of the second circulation path C2 may mean a passage inlet through which the manufacturing solution is led to the second circulation path C2. Further, the lower portion of the treatment tank 10 may mean a portion of the treatment tank 10 in accordance with the intermediate horizontal line of the treatment tank 10. For example, the inlet of the second circulation path C2 may be in contact with or approach the bottom of the treatment tank 10.

In embodiments of the present disclosure, the temperature of the processing tank 10 may be more efficiently controlled by the temperature control unit 140. In particular, the temperature control unit 140 can be configured to raise the temperature of the manufacturing solution contained within the processing tank 10. At this time, in the manufacturing solution contained in the treatment tank 10, a low temperature The manufacturing solution is mainly located in the lower portion of the processing tank 10. If the inlet of the second circulation path C2 is located in the lower portion of the treatment tank 10 as in the present embodiment, the manufacturing solution having a low temperature can be preferentially heated. Therefore, in the embodiment of the present disclosure, the temperature of the manufacturing solution contained in the treatment tank 10 can be easily increased, and the temperature can be uniformly controlled. Meanwhile, the outlet of the first circulation path C1 as the discharge outlet of the manufacturing solution passing through the first circulation path C1 may be located at the lower portion of the treatment tank 10.

When the temperature of the manufacturing solution passes through the first circulation path C1, it may be somewhat lowered compared to the processing tank 10. Therefore, the manufacturing solution having the descending temperature discharged from the first circulation path C1 is preferably discharged directly to the lower portion of the treatment tank 10 instead of the upper portion thereof. If the manufacturing solution having the falling temperature is discharged to the upper portion of the processing tank 10, the manufacturing solution having the falling temperature can be lowered to the existing one contained in the processing tank 10 when moving to the lower portion of the processing tank 10. Make solution temperature. However, in the present embodiment, the problem can be prevented.

In addition, if the inlet of the second circulation path C2 is located in the lower portion of the processing tank 10, if the outlet of the first circulation path C1 is located in the lower portion of the processing tank 10, it is discharged from the first circulation path C1. The low temperature manufacturing solution can directly flow into the second circulation path C1 and raise the temperature. Therefore, in the disclosed embodiment, the temperature of the manufacturing solution contained in the treatment tank 10 can be more efficiently controlled.

Meanwhile, the exit of the first circulation path C1 may be located on the opposite side of the entrance of the second circulation path C2. For example, the exit of the first circulation path C1 may be located at the lower right portion of the processing tank 10, and the second circulation path C2 The inlet can be located in the lower left portion of the processing tank 20. In particular, the outlet of the first circulation path C1 and the inlet of the second circulation path C2 may be formed at the same horizon of the processing tank 10. In the disclosed embodiment, the manufacturing solution discharged from the first circulation path C1 can be horizontally moved and flow into the second circulation path C2, and thus the low temperature manufacturing solution discharged from the first circulation path C1 can quickly flow into the first The second loop path C2, thereby ensuring easier temperature control.

Meanwhile, preferably, the apparatus for recovering a polarizing plate manufacturing solution according to the present disclosure may further include a concentration control unit 150 as shown in FIG.

The concentration control unit 150 can control the concentration of the manufacturing solution contained in the processing tank 10 within a predetermined range. By treating the polyvinyl alcohol film and operating the filtration unit 120, for example, the boric acid and potassium iodide components contained in the production solution of the treatment tank 10 can be gradually lowered, and thus the concentration of the production solution can be changed. However, if the concentration control unit 150 is provided as in the present embodiment, the concentration control unit 150 maintains the concentration of the manufacturing solution within a predetermined range, and thus the execution efficiency of the polyvinyl alcohol film treatment is not caused by the manufacturing The solution deteriorates.

At this time, if boric acid, potassium iodide, and/or iodine are contained in the production solution, the concentration control unit 150 may control the concentration of the production solution such that the total weight of the production solution contained in the treatment tank 10 is compared. Boric acid has a concentration of from 0.1% to 10%, potassium iodide has a concentration of less than 10% and/or iodine has a concentration of less than 1%.

The processing tank 10 for manufacturing a polarizing plate according to the present disclosure may include the above-described apparatus for recovering a polarizing plate manufacturing solution. In other words, the above An apparatus for recovering a polarizing plate manufacturing solution can be applied to the processing tank 10 to manufacture a polarizing plate. At this time, the treatment tank 10 for manufacturing the polarizing plate may include a dyeing tank for dyeing a polyvinyl alcohol film, a crosslinking groove for crosslinking the polyvinyl alcohol film, and a film for extending the polyvinyl alcohol film. An extension slot. Therefore, the apparatus for recovering the polarizing plate manufacturing solution can be installed in the dyeing tank, the crosslinking tank, and/or the extending tank.

The polarizing plate manufacturing apparatus according to the present disclosure may include the above-described apparatus for recovering a polarizing plate manufacturing solution. Further, in addition to the above apparatus for recovering a polarizing plate manufacturing solution, the polarizing plate manufacturing apparatus may further include a method for manufacturing a polyvinyl alcohol film and supplying the polyvinyl alcohol film to the processing tank 10 to manufacture a polarizing plate. s installation.

FIG. 7 is a schematic flow chart illustrating a method for recovering a polarizing plate manufacturing solution according to an embodiment of the present disclosure. Here, the subject matter for performing each of the steps in FIG. 7 can be regarded as each element of the apparatus for recovering a polarizing plate manufacturing solution according to the present disclosure.

As shown in FIG. 7, in the method for recovering a polarizing plate manufacturing solution according to the present disclosure, a part of the manufacturing solution is taken up (S110) from the processing tank 10 containing a manufacturing solution. Next, the receiving manufacturing solution is cooled (S120), and then, a particle of a predetermined size or more is filtered out from the cooling manufacturing solution (S130). Thereafter, the production solution from which the predetermined fine particles are filtered is heated (S140), and then, the heated production solution is discharged to the treatment tank 10 (S150).

Preferably, in step S120, the manufacturing solution may be heated such that a polyvinyl alcohol molecule and a boric acid cross-linking substance may be gelatinized. E.g, In step S120, the manufacturing solution may be cooled to a temperature of 0 ° C to 30 ° C, preferably to a temperature of 5 ° C to 10 ° C.

Preferably, in step S130, the polyvinyl alcohol molecules and the boric acid cross-linking substance formed in step S130 can be filtered off.

Preferably, the method for recovering a polarizing plate manufacturing solution according to the present disclosure may further include controlling the temperature of the manufacturing solution contained in the processing tank 10 within a predetermined range.

Meanwhile, preferably, the method for recovering a polarizing plate manufacturing solution according to the present disclosure may further include controlling the concentration of the manufacturing solution contained in the processing tank 10 within a predetermined range.

Hereinafter, the disclosure will be described in detail by way of examples and comparative examples. However, the examples of the disclosure may take some other forms, and the scope of the disclosure should not be construed as limiting the following examples. The disclosure is provided to more fully illustrate the disclosure of those skilled in the art.

As another embodiment of the present disclosure, the apparatus for recovering a polarizing plate manufacturing solution is constructed as shown in FIG. 6, and the apparatus is installed in a processing tank (an extending groove) containing a polarizing plate manufacturing solution. . At this time, the polarizing plate production solution used water as a solvent and contained potassium iodide and boric acid in the amounts listed in Table 1.

In addition, the temperature of the manufacturing solution contained in the processing tank 10 is maintained at 56 ° C by the temperature control unit 140, and the circulation amount of the first circulation path C1 passing through the cooling unit 110, the filtering unit 120, and the heating unit 130 Is set to pass the second circulation path C2 of the temperature control unit 140 10% of the amount of circulation.

In addition, the cooling unit 110 has a panel heat exchanger and cools the manufacturing solution to a temperature of 7 ° C to 8 ° C, and the filter unit 120 has a filter of 3 μm filter size and a filter of 1 μm filter size. These filters are arranged in series and in parallel as shown in FIG. Further, the heating unit 130 has a panel-shaped heat exchanger to reheat the manufacturing solution passing through the filtering unit 120 to 56 ° C and supply the manufacturing solution to the processing tank 10.

Further, although not shown in FIG. 6, the concentration control unit 150 is installed in the treatment tank 10 to maintain the manufacture contained in the treatment tank 10 by dropping a 6% boric acid solution and a 12% potassium iodide solution. Solution concentration.

Further, after the above circulation system was constructed, a polyvinyl alcohol film was immersed in the production solution contained in the treatment tank 10 for 24 hours, and then, the concentration of the production solution contained in the treatment tank 10 was analyzed. The results of this analysis are shown in Table 2 below.

From the results in Table 2, it was found that the contents of potassium iodide (KI) and boric acid (H ₃ BO ₃ ) were in fact maintained constant compared to the results of Table 1, but the polyvinyl alcohol molecules were greatly reduced from 15 ppm to 0.5 ppm. In other words, it can be understood that the polyvinyl alcohol molecules in the production solution are not increased but decreased, even if the polyvinyl alcohol film is continuously immersed in the polarizing plate production solution. Therefore, in the present disclosure, the problem that the polyvinyl alcohol molecules are gradually increased in the polarizing plate production solution to waste the solution can be truly solved, and thus the manufacturing cost or the difference of the polarizing plate can be effectively reduced.

This disclosure has been described in detail. It should be understood, however, that the description of the preferred embodiments of the invention, The detailed description becomes apparent.

Claims (19)

An apparatus for recovering a polarizing plate manufacturing solution, the polarizing plate manufacturing solution containing boric acid to manufacture a polarizing plate from a polyvinyl alcohol-based film, the device comprising: a cooling unit configured to receive the manufacturing solution from the inside a part of a treatment tank for producing a solution and cooling the production solution; a filtration unit configured to filter particles of a predetermined size or more from the production solution cooled by the cooling unit; and a heating unit, the structure is heated The manufacturing solution of the filtration unit is passed through and the production solution is discharged to the treatment tank. An apparatus for recovering a polarizing plate manufacturing solution according to claim 1, wherein the cooling unit cools the manufacturing solution at a temperature that allows a polyvinyl alcohol molecule and a cross-linking substance of boric acid to coagulate. An apparatus for recovering a polarizing plate production solution according to the second aspect of the patent application, wherein the cooling unit cools the production solution at a temperature of 0 ° C to 30 ° C. An apparatus for recovering a polarizing plate production solution according to the third aspect of the patent application, wherein the cooling unit cools the production solution at a temperature of 5 ° C to 10 ° C. The apparatus for recovering a polarizing plate manufacturing solution according to the second aspect of the patent application, wherein the filtering unit filters out the condensed polyvinyl alcohol molecule and the cross-linking substance of boric acid. An apparatus for recovering a polarizing plate manufacturing solution according to the first aspect of the patent application, wherein the filtering unit comprises at least two filters having different filter sizes. The apparatus for recovering a polarizing plate manufacturing solution according to claim 6, wherein the filtering unit comprises a first filter having a filter size of 10 μm or less and a second filter having a filter size of 5 μm or less. And being structured such that the manufacturing solution sequentially passes through the first filter and the second filter. The apparatus for recovering a polarizing plate manufacturing solution according to claim 6, wherein the filter unit comprises a first filter having a filter size of 3 μm or less and a second filter having a filter size of 1 μm or less. And being structured such that the manufacturing solution sequentially passes through the first filter and the second filter. The apparatus for recovering a polarizing plate manufacturing solution according to claim 1, wherein the filtering unit may include at least two parallel filters having the same filter size, and is configured such that the manufacturing solution selectively passes the at least One of the two filters. An apparatus for recovering a polarizing plate manufacturing solution according to the first aspect of the invention, wherein at least one of the cooling unit and the heating unit has a panel-shaped heat exchanger. The apparatus for recovering a polarizing plate manufacturing solution according to the scope of claim 1 of the patent application further includes: A temperature control unit is configured to receive the manufacturing solution from the processing tank and to control the temperature of the manufacturing solution contained in the processing tank to a predetermined range by heat exchange with the receiving manufacturing solution. The apparatus for recovering a polarizing plate manufacturing solution according to claim 11 , wherein the temperature control unit is provided in a manufacturing solution circulation path, different from a cooling unit, the filtering unit, and the heating unit Make a solution circulation path. The apparatus for recovering a polarizing plate manufacturing solution according to claim 12, wherein the manufacturing solution circulation path through the cooling unit, the filtering unit, and the heating unit has a manufacturing solution circulation amount, which is compared with The manufacturing solution circulation path through the temperature control unit is 5% to 20% of the throughput of the manufacturing solution. The apparatus for recovering a polarizing plate manufacturing solution according to claim 11, wherein the temperature control unit controls the temperature of the manufacturing solution contained in the processing tank to a range of 25 ° C to 65 ° C. The apparatus for recovering a polarizing plate manufacturing solution according to claim 1 of the patent application, further comprising: a concentration control unit configured to control a concentration of the manufacturing solution contained in the processing tank to a predetermined range. An apparatus for recovering a polarizing plate manufacturing solution according to the fifteenth aspect of the patent application, wherein the manufacturing solution further comprises at least one of potassium iodide and iodine in addition to the boric acid, and wherein the concentration control unit controls the inclusion in The concentration of the manufacturing solution of the treatment tank is such that the boric acid has a concentration of 0.1% to 10% compared to the total weight of the production solution contained in the treatment tank. The potassium iodide has a concentration of less than 10%, and the iodine has a concentration of less than 1%. A processing tank for manufacturing a polarizing plate, comprising the apparatus for recovering a polarizing plate manufacturing solution as defined in any one of claims 1 to 16. An apparatus for manufacturing a polarizing plate, comprising the apparatus for recovering a polarizing plate manufacturing solution as defined in any one of claims 1 to 16. A method for recovering a polarizing plate manufacturing solution, the polarizing plate manufacturing solution containing boric acid to produce a polarizing plate from a polyvinyl alcohol-based film, the method comprising: receiving a part from a processing tank containing the manufacturing solution Manufacturing a solution; cooling the supported manufacturing solution; filtering out particles of a predetermined size or more from the cooled manufacturing solution; heating the filtered manufacturing solution; and discharging the heated manufacturing solution to the processing tank.