JP4449068B2 - Electrodialyzer for recycling developer waste - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electrodialysis apparatus for regenerating development waste liquid generated in the manufacture of electronic devices such as semiconductor devices (LSIs, etc.), liquid crystal display panels (LCDs), color filters, and printed circuit boards.
[0002]
[Prior art]
In the development process of LSI, LCD, printed circuit boards, color filters, etc., a photosensitive resin called a photoresist is applied onto a substrate such as a wafer or glass plate, for example, through a mask on which a development pattern is drawn. A photolithographic method is used in which a resist is exposed to photoreact and a development pattern is formed by etching (dissolving) the photoresist with a developer. There are two types of photoresists: positive photoresists in which the exposed part is soluble (etched) in the developer and negative photoresists in which the exposed part is insoluble in the developer. Alkaline developer is mainly used, and there are also those that use an alkaline developer although the latter development is small. In recent electronic industry fields such as LSI and LCD, metal components are extremely disliked, so tetramethylammonium hydroxide (hereinafter sometimes abbreviated as “TMAH”) or tetraalkylammonium hydroxide such as choline is used as such an alkaline developer. It is common to use an aqueous solution (hereinafter referred to as “TAAH”) in water (organic alkaline aqueous solution). Accordingly, in this case, the development waste liquid generated in the development process in the electronic industry such as LSI and LCD mainly includes TAAH (particularly TMAH) and dissolved photoresist.
[0003]
In recent years, attempts have been made to concentrate and recover TAAH contained in a developing waste solution, and an electrodialysis apparatus is also used as one of the apparatuses. The principle and usage of electrodialysis are described, for example, in JP-A-7-328642. In the electrodialysis apparatus, a plurality of cells are configured by alternately arranging a cation exchange membrane and an anion exchange membrane between a cathode and an anode. The cell having the anion exchange membrane on the side facing the cathode functions as a concentrate chamber, where TAAH is concentrated to become a concentrate, and the cell having the anion exchange membrane on the side facing the anode functions as a desalting solution chamber. In this case, TAAH is reduced to a desalted solution.
[0004]
As an electrode solution chamber of an electrodialysis apparatus, there are an anolyte chamber in contact with the anode and a catholyte chamber in contact with the cathode. When the anolyte and the catholyte are passed through the anolyte chamber and the catholyte chamber as separate electrode solutions, respectively (FIG. 10). Or a common electrode solution may be passed through both the anolyte chamber and the catholyte chamber (see FIG. 11).
[0005]
In either case, an aqueous solution of TAAH of the same type as TAAH contained in the development waste solution is used for the electrode solution (anolyte / catholyte) in order to reduce the contamination of impurities into the concentrated solution that becomes the recovered and regenerated TAAH solution. Yes.
[0006]
Next to the electrode solution chamber is a desalting solution chamber (TAAH is reduced to become desalted waste solution) through which the developing waste solution passes, or a concentrated solution chamber (TAAH is increased to become concentrated solution) through which pure water or a TAAH aqueous solution is passed. is there. However, as disclosed in JP-A-7-328642, JP-A-11-190907, JP-A-11-192481, etc., in some cases, the development waste liquid or the TAAH-containing treatment liquid is used as the TAAH aqueous solution. Sometimes used. In order to minimize the influence of impurities from the electrode liquid chamber (solute materials from electrode materials, products generated by electrode reaction, generated gas, etc.) into the recovered and regenerated TAAH solution, the electrode liquid chamber and the concentrated liquid chamber should be separated. In some cases, the desalting solution chamber may be adjacent to the electrode solution chamber (see the cell stack structure in FIGS. 12 and 13), but is not limited to this (see the cell stack structure in FIGS. 14 and 15).
[0007]
An electrodialysis apparatus is often operated by circulating an electrode solution. If such a circulation operation is continued, the amount of impurities in the electrode solution flowing through the electrode solution chamber increases. In particular, when the electrode chamber is adjacent to the concentrate chamber, impurities are mixed into the concentrate (recovered and regenerated TAAH solution) flowing through the concentrate chamber, and therefore it is necessary to periodically replace the electrode solution. If the desalting chamber is next to the electrode chamber, impurities can be mixed into the concentrate via the desalting chamber, although the degree can be reduced. It is. In addition, since the electrode liquid chamber functions in the same manner as the desalting liquid chamber or the concentrated liquid chamber depending on its configuration, the concentration (TAAH) concentration of the electrode liquid may increase or decrease with the operation of the apparatus depending on the configuration mode. Therefore, in order to keep the conductivity within a desired range, when the component concentration increases, it is diluted with pure water, and when the component concentration decreases, the electrode solution component (TAAH) is added. In some cases, the concentration of the components is constantly, regularly or irregularly adjusted so as to be within a certain range.
[0008]
[Problems to be solved by the invention]
In particular, TAAH is oxidized at the anode to become an oxidative decomposition product that emits a strong amine odor, and this becomes a main impurity. Therefore, when the anolyte and the catholyte are used as separate electrode liquids, the anode flowing in the anolyte chamber is used. Impurities increase in the liquid, and even when one common electrode solution is passed through the anolyte chamber and the catholyte chamber, the impurity concentration in the common electrode solution increases. Although the identification of the oxidative decomposition product has not yet been made, it can be distinguished because it has a strong odor.
[0009]
Therefore, according to the present invention, the contamination of the concentrated liquid due to the increase in the amount of impurities in the electrode liquid is reduced as much as possible, and in the case of using the electrode liquid circulation, the frequency of electrode liquid replacement can be reduced. It is intended to provide an electrodialysis apparatus for developing waste liquid regeneration.
[0010]
[Means for Solving the Problems]
The present invention relates to an electrodialysis apparatus for recovering tetraalkylammonium hydroxide from a developing waste liquid, wherein a separate liquid chamber other than a desalting liquid chamber, a concentrated liquid chamber, and an electrode liquid chamber is used as two electrodes of an anolyte chamber and a catholyte chamber An electrodialyzer for developing waste liquid regeneration, which is arranged next to both of the liquid chambers or only next to the anolyte chamber and configured to pass a tetraalkylammonium hydroxide-containing aqueous solution through the separate liquid chamber. Is to provide.
[0011]
One main component contained in the developing waste liquid is a component of the developing solution. As described above, in the electronic industry such as LSI and LCD, this component is usually TAAH. Examples of such TAAH include tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, methyltriethylammonium hydroxide, trimethylethylammonium hydroxide, dimethyldiethylammonium hydroxide. , Trimethyl (2-hydroxyethyl) ammonium hydroxide (ie, choline), triethyl (2-hydroxyethyl) ammonium hydroxide, dimethyldi (2-hydroxyethyl) ammonium hydroxide, diethyldi (2-hydroxyethyl) ammonium hydroxide, Methyl tri (2-hydroxyethyl) ammonium hydroxide, ethyl tri (2-hydroxyethyl) ammonium hydroxide, tetra (2-hydroxyethyl) ammonium hydroxide It can be mentioned beam, such as the (especially TMAH).
[0012]
Tetraalkylammonium (TAA) ions (TAA) in developer wastewater ⁺ ) Is a hydroxide ion (OH ⁻ )) Is usually included as TAAH. However, the developer may have a certain degree of buffering function, or depending on the factory, the developer wastewater may be mixed or neutralized with other wastewater. Inorganic anions such as fluoride ion, chloride ion, bromide ion, carbonate ion, bicarbonate ion, sulfate ion, hydrogen sulfate ion, nitrate ion, phosphate ion, hydrogen phosphate ion, dihydrogen phosphate ion, formate ion, acetic acid In general, at least one ion selected from organic anions such as ions and oxalate ions is at least part of the counter ions of the TAA ions. In particular, carbonate ions and hydrogen carbonate ions are often present in a small amount as carbon dioxide in the air dissolves in the developing waste solution. However, in this specification, in order to simplify the description, it is assumed that the developing waste solution contains “TAAH”, and TMAH is often used. In addition to the case where the development waste liquid itself is directly fed to the electrodialysis apparatus of the present invention, at least one treatment of various treatments such as reverse osmosis membrane treatment, evaporation treatment, nanofiltration membrane treatment, ion exchange treatment, etc. The electrodialyzer of the present invention is prepared by subjecting a TAAH-containing treatment solution obtained by carrying out the treatment to a developing waste solution (for example, see JP-A-11-190907, JP-A-11-192481, JP-A-10-85741). There is also a case where the liquid is sent to the liquid, and this case is also indirect, but the development waste liquid is regenerated using an electrodialyzer and is included in the scope of the present invention. Therefore, the former case will be mainly described.
[0013]
The ion exchange membrane used in the electrodialyzer is not particularly limited as long as it can selectively separate cations and anions. For example, Aciplex [Asahi Kasei Kogyo Co., Ltd.], Ceremon [Asahi Glass] Co., Ltd.], Neoceptor [Tokuyama Soda Co., Ltd.], ion clad EDS membrane [Pole Co., Ltd.], Nafion (DuPont), and the like. Further, the characteristics of the ion exchange membrane may be general.
[0014]
The general structure of the electrodialyzer is not particularly limited. For example, the cation exchange membrane and the anion exchange membrane are divided into an inflow hole and an outflow hole for liquid to be desalted, and an inflow hole and an outflow hole for liquid to be concentrated. A plurality of cells may be stacked alternately with appropriate intervals at a provided gasket to form a stack of cells, and both ends may be sandwiched between a pair of electrodes, but in the electrodialysis apparatus of the present invention, It is characterized in that a separate liquid chamber is provided. The number of membrane pairs placed between a pair of electrodes is not particularly limited, but is usually 10 to 100. Here, the “separate liquid chamber” means that the liquid passed through it is treated separately from the electrode liquid, concentrated liquid, and desalted liquid. Prepared separately from the liquid and desalting solution.
[0015]
Here, instead of the anion exchange membrane, a neutral membrane such as polyvinyl alcohol having alkali resistance superior to that of the anion exchange membrane may be used. Neutral membranes are simply polymer membranes without ionic functional groups, but they can pass TAA ions, but their permeability is lower than that of cation exchange membranes. Thus, concentration by electrodialysis can be performed. However, when a neutral membrane is used instead of an anion exchange membrane, the current efficiency is worse than in the case of an anion exchange membrane.
[0016]
Such an electrodialysis apparatus may be a single-pass system (one-pass). For example, a circulation processing system or a multi-stage processing system as disclosed in JP-A-7-328642 can be adopted. It may be a formula, a semi-batch type, or a continuous type.
[0017]
Here, “concentrated solution” and “desalted solution” are terms that are selectively used depending on whether the TAAH content increases or decreases, and do not indicate which TAAH concentration is higher or lower.
[0018]
By providing a separate liquid chamber and allowing the TAAH aqueous solution to pass through the separate liquid chamber as a separate liquid, it is possible to prevent the impurities of the electrode liquid (particularly the anolyte) from entering the concentrated liquid and obtain a high-purity concentrated liquid. . In addition, when the electrode solution is used in circulation, the replacement frequency of the electrode solution can be reduced, so that there is an advantage that the amount of TAAH aqueous solution used as the electrode solution and the amount of drainage can be reduced.
[0019]
When a TAAH aqueous solution is used as the anolyte, TAAH is oxidized at the anode, and its oxidative decomposition products are generated as main impurities in the anolyte chamber. Therefore, when anolyte and catholyte are used as separate electrode solutions, a separate solution chamber is provided at least next to the anolyte chamber. In this case, since the concentration of impurities in the catholyte (such as solutes from the electrode material) increases during long-term circulation operation, another liquid chamber may be provided next to the catholyte chamber. Of course, in the catholyte chamber, no decomposition product of TAAH is produced, so there is little need for it, and the catholyte may be handled as a concentrate. When one common electrode solution is used as the anolyte and the catholyte, impurities such as oxidative decomposition products of TAAH produced at the anode also enter the catholyte chamber, so another liquid chamber is provided next to the catholyte chamber. The separate liquid chamber may be a single chamber system in which only one chamber is provided next to (each) the anolyte chamber (and the catholyte chamber), or may be a multi-chamber system in which two or more chambers are provided. In the latter case, the apparatus configuration is complicated, but it is possible to more strongly prevent impurities from the electrode solution from being mixed into the concentrated solution.
[0020]
Conventionally, a TAAH aqueous solution has been used as the electrode solution. However, in the electrodialysis apparatus of the present invention in which a separate liquid chamber is provided next to the electrode solution chamber, other aqueous solutions can be used as the electrode solution. . For example, when using an anolyte and a catholyte as separate electrode solutions, an aqueous solution such as sulfuric acid or nitric acid may be used as the anolyte, and the impurities ( In this example, there is almost no mixing of sulfate ion, nitrate ion, etc.). In this case, TAAH is not used, so there is no oxidative decomposition product of TAAH, and a strong amine odor does not occur. In this case, the membrane forming the anolyte chamber (the membrane adjacent to the anode) is used to reduce the amount of anion components such as sulfate ions and nitrate ions mixed into the desalting solution and concentrated solution (via another solution). Further, a cation exchange membrane is preferable. Since TAAH does not decompose in the catholyte chamber, there is no merit of using other aqueous solutions such as sulfuric acid and nitric acid as the catholyte.
[0021]
The separate liquid passed through the separate liquid chamber is an aqueous solution of TAAH. It goes without saying that a new TAAH aqueous solution or a recovered and regenerated TAAH aqueous solution can be used, but a development waste solution or a TAAH-containing treatment solution derived therefrom may be used. Moreover, you may use the desalination waste liquid obtained from the electrodialysis apparatus of this invention as another liquid. This desalted waste liquid is a liquid that has been passed through the desalted liquid chamber, and although the TAAH concentration has decreased, there is almost no increase in impurity concentration, so there is no problem in purity, and this is not directly discharged out of the system. Further, by passing it through a separate liquid chamber before discharge, it is possible to obtain advantages such as an improvement in the TAAH recovery rate and a reduction in the total amount of drainage. When this desalted waste liquid is used as a separate liquid to be passed through the separate liquid chamber, its TAAH concentration is generally in the range of 0.01 to 1% by weight. The concentration is determined by various conditions such as the TAAH concentration of the developing waste liquid, the desired TAAH concentration of the recovered and regenerated TAAH solution (concentrated liquid), the TAAH recovery rate, and the like.
[0022]
Impurities from the electrode liquid gradually migrate to the separate liquid that passes through the separate liquid chamber. Therefore, the separate liquid is always one-pass (single-flow liquid), or is used periodically or partly or periodically. It is necessary to discharge irregularly. When circulating, the concentration of impurities derived from the electrode solution in the separate solution is sufficiently low compared to the electrode solution, so the amount of the separate solution that is discharged regularly or partly regularly or irregularly outside the system And the frequency of the exchange is low. As described above, the separate liquid chamber may be provided in a multi-chamber system.
[0023]
The separate liquid used in the separate liquid chamber only needs to have conductivity that does not greatly increase the electric resistance of the electrodialysis tank, and the conductivity is in the range of 1 to 50 mS / cm, but is not limited thereto. The conductivity may be below this range or above this range. However, if the conductivity is too low, the electrical resistance of the electrodialysis tank will increase. On the other hand, if the conductivity is too high, the TAAH that is clogged due to the high TAAH concentration is wasted.
[0024]
As described above, the separate liquid used in the separate liquid chamber is an aqueous solution of TAAH, and a new TAAH aqueous solution or a recovered and regenerated TAAH solution may be used or may be prepared. The contained treatment liquid, the desalted waste liquid obtained from the electrodialysis apparatus of the present invention, or the like may be used or prepared with this. However, considering the fact that new TAAH and recovered TAAH solution can be used as a developer as they are, development waste solution and TAAH-containing processing solution derived from it can be used as raw materials for recovered and recovered TAAH solution. Therefore, it is particularly preferable to use the desalted waste liquid as a separate liquid. Further, a concentrated liquid obtained by the above-described nanofiltration membrane treatment can be used as a separate liquid.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited thereto. In each of the drawings including FIGS. 10 to 15 conceptually showing the flow of the electrode solution and the cell stack structure of the electrodialysis tank of the conventional electrodialysis apparatus, E is an electrode solution chamber, Ea is an anolyte chamber, and Ec is a cathode. Liquid chamber, O is a separate liquid chamber, D is a desalted liquid chamber, C is a concentrated liquid chamber, A is an anion exchange membrane, K is a cation exchange membrane, N is a neutral membrane, E solution is an electrode solution, and C solution is concentrated Liquid, liquid D represents a desalted liquid, liquid O represents a separate liquid flowing in a separate liquid chamber, (C) indicates that it can function in the same manner as the concentrated liquid chamber, and (D) represents the same as the desalted liquid chamber. (N) indicates that the neutral membrane N may be used in place of the anion exchange membrane, and “C / D” indicates a stacked cell stack of the concentrate chamber and the desalting chamber. Indicates the state.
[0026]
As the cell stack structure of the electrodialysis tank of the electrodialysis apparatus of the present invention, various systems as shown in FIGS. 1 to 6 can be adopted.
[0027]
FIG. 1 is a schematic explanatory view conceptually showing an example of a cell stack structure of an electrodialysis tank of the electrodialysis apparatus of the present invention. Since the separate liquid chamber O adjacent to the anolyte chamber Ea has an anion exchange membrane facing the anode, the movement of TAA ions in the anolyte to the separate liquid chamber is almost prevented, but in the separate liquid The hydroxide ions move through the anion exchange membrane to the anolyte chamber. Further, since the separate liquid chamber faces the cathode and has a cation exchange membrane, TAA ions in the separate liquid move to the adjacent concentrated liquid chamber C. On the other hand, since the separate liquid chamber O adjacent to the catholyte chamber Ec has a cation exchange membrane facing the cathode, TAA ions in the separate liquid move to the catholyte chamber through the cation exchange membrane. . Further, since this separate liquid chamber has an anion exchange membrane facing the anode, the hydroxide ions in the separate liquid move to the adjacent concentrated liquid chamber C. Therefore, these separate liquid chambers function similarly to the desalting liquid chamber. When one common electrode solution is used as the anolyte and the catholyte, the anolyte chamber and the catholyte chamber can function in the same way as the concentrate chamber. At the anode, hydroxide ions emit electrons to generate water and oxygen gas, and at the cathode, hydrogen ions receive electrons to generate hydrogen gas and hydroxide ions, and the ion balance in the anolyte and catholyte Is maintained.
[0028]
The desalting solution chamber D is a cell having an anion exchange membrane facing the anode and a cation exchange membrane facing the cathode, and TAAH hydroxide ions pass through the anion exchange membrane to the anode side. While moving, TAA ions of TAAH move to the cathode side through the cation exchange membrane. The transferred hydroxide ions are almost blocked by the next cation exchange membrane, and the transferred TAA ions are almost blocked by the next anion exchange membrane. The concentrated liquid chamber C is a cell having a cation exchange membrane facing the anode and an anion exchange membrane facing the cathode, and hydroxide ions moving from the desalting liquid chambers on both sides of the cell. TAAH is concentrated by TAA ions. Although the dissolved photoresist has ionized carboxylic acid groups, phenolic hydroxyl groups, etc., the dissolved photoresist hardly moves through the anion exchange membrane because it is a polymer substance, and its concentration changes little in each solution. do not do.
[0029]
2 to 6 are schematic explanatory views conceptually showing other examples of the cell stack structure of the electrodialysis tank of the electrodialysis apparatus of the present invention. Also in these cell stack structures, the function of each chamber can be considered in the same manner as described for the cell stack structure in FIG. 1 from the relationship between both ion exchange membranes, the anode and the cathode.
[0030]
In the cell stack structure of FIG. 2, in contrast to the case of FIG. 1, the separate liquid chamber O functions similarly to the concentrated liquid chamber. In this case, both the electrode liquid chambers Ea and Ec are the same as the desalted liquid chamber. Can function.
[0031]
In the cell stack structure of FIG. 3, the separate liquid chamber O adjacent to the anolyte chamber Ea functions in the same manner as the concentrated liquid chamber, and the separate liquid chamber O adjacent to the catholyte chamber Ec functions in the same manner as the desalted liquid chamber. . Therefore, in this case, when the separate liquids in both separate liquid chambers are joined and circulated, the TAAH concentration does not substantially change. In addition, the anolyte chamber Ea functions in the same manner as the desalting solution chamber, and the catholyte chamber Ec functions in the same manner as the concentrated solution chamber. Therefore, when the two electrode solutions are combined and used as a common electrode solution, The TAAH concentration hardly changes.
[0032]
The cell stack structure of FIG. 4 is similar to the cell stack structure of FIG. 3 except that the separate liquid chamber O adjacent to the anolyte chamber Ea is a cell composed of two cation exchange membranes. TAA ions move from the anolyte chamber Ea to this separate liquid chamber, but TAA ions move from this separate liquid chamber to the concentrated liquid chamber C adjacent to this separate liquid chamber. Although it does not change, the TAAH concentration decreases when combined with another liquid in the separate liquid chamber O next to the catholyte chamber Ec (functioning in the same manner as the desalting liquid chamber), so the separate liquid chamber O next to the anolyte chamber Ea. Also, “(D)” is displayed for convenience.
[0033]
In the cell stack structure of FIG. 5, the separate liquid chamber O adjacent to the anolyte chamber Ea is a cell composed of two anion exchange membranes, and this separate liquid chamber is hydroxylated from the adjacent desalted liquid chamber D. Although the substance ions move, hydroxide ions move from the separate liquid chamber to the anolyte chamber Ea. In this cell stack structure, the separate liquid chamber O adjacent to the catholyte chamber Ec is a cell composed of two cation exchange membranes, and TAA ions move from the separate liquid chamber to the catholyte chamber Ec. However, TAA ions move from the desalting solution chamber D adjacent to the separate liquid chamber to the separate liquid chamber. Therefore, the TAAH concentration of the separate liquid is not substantially changed in both separate liquid chambers.
[0034]
In the cell stack structure of FIG. 6, the separate liquid chamber O adjacent to the anolyte chamber Ea is a cell composed of two cation exchange membranes, and TAA ions move from the anolyte chamber Ea to this separate liquid chamber. However, TAA ions move from the separate liquid chamber to the concentrated liquid chamber C adjacent to the separate liquid chamber. The separate liquid chamber O adjacent to the catholyte chamber Ec is a cell composed of two anion exchange membranes, and hydroxide ions move from the separate liquid chamber to the concentrated liquid chamber C adjacent thereto. However, hydroxide ions move from the catholyte chamber Ec to this separate chamber. Therefore, the TAAH concentration of the separate liquid is not substantially changed in both separate liquid chambers.
[0035]
As described above, the cell stack structure of the electrodialysis tank that can be used in the present invention has been briefly described. However, when the desalted waste liquid from the desalted liquid chamber is used as a separate liquid, the residual TAAH in the desalted waste liquid is more efficiently used. The cell stack structure of FIG. 1 is preferable in that it is taken into the concentrated liquid, and the cell stack structure of FIG. 3 is preferable in that the electrode liquid and the separate liquid can be circulated for a long period of time. Further, the cell stack structure shown in FIGS. 2 and 5 is preferable in that the electrode liquid chamber and the concentrated liquid chamber are separated from each other.
[0036]
FIG. 7 is a schematic flow diagram conceptually showing an example of the electrodialysis apparatus of the present invention. Electrode solution (E solution), concentrated solution (C solution), desalted solution (D solution), and separate solution (O solution) are sent from each water tank to the electrodialysis tank and subjected to electrodialysis treatment. A line (pipe) for circulation is provided so as to be returned to the water tank. In this example, as necessary, the desalting solution tank is replenished with development waste liquid, the concentrated liquid tank is replenished with pure water, and the electrode liquid tank and the separate liquid chamber are replenished with TMAH and pure water. Further, as required, liquid is blown from the electrode liquid tank and the separate liquid chamber. The separate liquid (O liquid) may be partly blown constantly even as a single pass.
[0037]
FIG. 8 is a schematic flow diagram conceptually showing another example of the electrodialysis apparatus of the present invention. This example is substantially the same as the example of FIG. 7 except that the desalted waste liquid obtained by electrodialysis is used as a separate liquid (O liquid). Therefore, the apparatus of FIG. A line (pipe) is provided from one to another liquid tank. Others are the same as in FIG. In Example 1 below, such an apparatus was used in a batch processing system.
[0038]
FIG. 9 is a schematic flow diagram conceptually showing an example of a conventional electrodialysis apparatus. Unlike the apparatus of FIG. 7 and FIG. 8, a separate liquid chamber and a separate liquid tank are not provided. In Comparative Example 1 below, such an apparatus was used in a batch processing system.
[0039]
【Example】
EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. The photoresist concentration was expressed by the absorbance at 290 nm (Abs 290 nm) itself derived from the photoresist.
[0040]
Example 1
Desalination solution using a batch processing type electrodialyzer as shown in FIG. 8 using the development waste solution [TMAH = 2.1 wt%, photoresist concentration (Abs 290 nm) = 3.0] discharged from the liquid crystal factory as a raw material. TMAH was concentrated and recovered under the conditions of an end point TMAH concentration of 0.1% by weight and a concentrated liquid end point TMAH concentration of 2.4% by weight. Here, the batch processing method means that the desalted solution or concentrated solution is renewed when the above end point condition is satisfied, and the desalted waste solution is taken out from the desalted solution tank and used instead of the developing waste solution. It was renewed by taking out the concentrate from the concentrate tank and adding pure water instead. In addition, the electrode solution is circulated and used without being renewed, and as a separate solution to be passed through a separate solution chamber, a desalted waste solution (a waste solution having a desalted solution end point TMAH concentration of 0.1% by weight through the desalted solution chamber) In the past, it was updated once a day using what was previously discarded. The electrodialysis tank is composed of a cation exchange membrane (Asaplex K-501 manufactured by Asahi Kasei Kogyo Co., Ltd.) and a neutral membrane (Aciplex PVA # 100 manufactured by Asahi Kasei Kogyo Co., Ltd.) as a cell stack structure as shown in FIG. It is configured. The electrode solution was passed through an anolyte chamber and a catholyte chamber using a 40 mS / cm TMAH aqueous solution as a common electrode solution. The separate liquid was a desalted waste liquid having a conductivity of 2.5 mS / cm, and was circulated and supplied to the separate liquid chamber except at the time of renewal. As the first separate liquid, a TMAH new liquid adjusted to a conductivity of 2.5 mS / cm using pure water was used.
[0041]
The apparatus was operated for 15 days at an operation rate of 8 hours per day. The electrode solution after 15 days had a strong amine odor, and the other solution also had a slightly strong amine odor. However, with respect to the concentrated solution, none of the concentrated solutions of all batches obtained on the 15th day from the beginning of the test had a strong amine odor.
[0042]
Comparative Example 1
A test was performed in substantially the same manner as in Example 1 except that the apparatus shown in FIG. 9 without a separate liquid chamber was used and no separate liquid was used. The electrodialysis tank has a cell stack structure as shown in FIG. 15 with a cation exchange membrane (Aciplex K-501 manufactured by Asahi Kasei Co., Ltd.) and a neutral membrane (Aciplex PVA # 100 manufactured by Asahi Kasei Co., Ltd.). It is a thing. The electrode solution after 15 days had a strong amine odor, and the concentrated solution on the 15th day had a slightly stronger amine odor than the initial test. From this, it was found that the TMAH oxidative decomposition product of the electrode liquid (particularly generated by the oxidation reaction of the anode) was mixed in the concentrate as an impurity.
[0043]
【The invention's effect】
In the electrodialysis apparatus for developing waste liquid regeneration according to the present invention, since a separate liquid chamber is provided, it is possible to reduce the contamination of impurities into the concentrated liquid due to an increase in the amount of impurities in the electrode liquid as much as possible. In the case of using the electrode solution circulation, it is possible to reduce the exchange frequency of the electrode solution.
[Brief description of the drawings]
FIG. 1 is a schematic explanatory view conceptually showing an example of a cell stack structure of an electrodialysis tank of an electrodialysis apparatus of the present invention.
FIG. 2 is a schematic explanatory view conceptually showing another example of the cell stack structure of the electrodialysis tank of the electrodialysis apparatus of the present invention.
FIG. 3 is a schematic explanatory view conceptually showing still another example of the cell stack structure of the electrodialysis tank of the electrodialysis apparatus of the present invention.
FIG. 4 is a schematic explanatory view conceptually showing still another example of the cell stack structure of the electrodialysis tank of the electrodialysis apparatus of the present invention.
FIG. 5 is a schematic explanatory view conceptually showing still another example of the cell stack structure of the electrodialysis tank of the electrodialysis apparatus of the present invention.
FIG. 6 is a schematic explanatory view conceptually showing still another example of the cell stack structure of the electrodialysis tank of the electrodialysis apparatus of the present invention.
FIG. 7 is a schematic flow diagram conceptually showing an example of the electrodialysis apparatus of the present invention.
FIG. 8 is a schematic flow diagram conceptually showing another example of the electrodialysis apparatus of the present invention.
FIG. 9 is a schematic flow diagram conceptually showing an example of a conventional electrodialysis apparatus.
FIG. 10 is a schematic explanatory view conceptually showing a conventional electrodialysis system in which an anolyte and a catholyte are passed as separate electrode solutions through an anolyte chamber and a catholyte chamber, respectively.
FIG. 11 is a schematic explanatory view conceptually showing a conventional electrodialysis system in which one common electrode solution is passed through electrode solution chambers of both an anolyte chamber and a catholyte chamber.
FIG. 12 is a schematic explanatory view conceptually showing an example of a cell stack structure of a conventional electrodialysis apparatus.
FIG. 13 is a schematic explanatory view conceptually showing another example of a cell stack structure of a conventional electrodialysis apparatus.
FIG. 14 is a schematic explanatory view conceptually showing still another example of a cell stack structure of a conventional electrodialysis apparatus.
FIG. 15 is a schematic explanatory view conceptually showing still another example of a cell stack structure of a conventional electrodialysis apparatus.
[Explanation of symbols]
E Electrolyte chamber
Ea anolyte chamber
Ec Catholyte compartment
O Separate liquid chamber
C Concentrate chamber
D Desalination chamber
A Anion exchange membrane
K cation exchange membrane
N Neutral membrane
E liquid Electrode liquid
C liquid concentrate
D liquid Demineralized liquid
O solution Separate solution
P pump

Claims (2)

An electrodialysis apparatus for recovering tetraalkylammonium hydroxide from a developing waste liquid, wherein a separate liquid chamber other than a desalting liquid chamber, a concentrated liquid chamber, and an electrode liquid chamber is provided as both an anolyte chamber and a catholyte chamber. An electrodialyzer for regenerating a developing waste liquid, wherein the electrodialyzer is configured to be disposed next to the anolyte chamber or only next to the anolyte chamber and to pass the tetraalkylammonium hydroxide-containing aqueous solution through the separate chamber. The electrodialysis apparatus for regenerating a development waste liquid according to claim 1, wherein the tetraalkylammonium hydroxide-containing aqueous solution is an aqueous solution further containing a photoresist.

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