KR102109403B1 - Purification method of thinner waste and Thinner composition manufactured therefrom) - Google Patents

Abstract

The present invention relates to a purification method of a thinner waste liquid which purifies the waste liquid of a thinner used in a rinse process to clean a photoresist during a semiconductor manufacturing process through a reduction step, and to a thinner composition obtained therefrom. The purification method of thinner waste liquid according to the present invention recovers the waste liquid of the thinner used in the rinsing process for cleaning the photoresist during the semiconductor manufacturing process to remove cyclohexanone and methyl amyl ketone (MAK), thereby providing a reusable thinner composition.

Description

Purification method of thinner waste and thinner composition manufactured therefrom)

The present invention relates to a method for purifying thinner waste liquid and a thinner composition obtained therefrom, and more specifically, purification of thinner waste liquid to purify the waste liquid of thinner used in a rinse process for cleaning photoresist during a semiconductor manufacturing process through a reduction step. It relates to a method and a thinner composition obtained therefrom.

The thinner for photoresist cleaning is used in a rinsing process for cleaning the photoresist remaining after the photolithography and etching process in the semiconductor or display manufacturing process. It is mixed and manufactured in various ways, but in the rinse process of the display manufacturing process, representatively 70% by weight of PGME (Propylene Glycol Methyl Ether, 1-Methoxy-2-Propanol) and PGMEA (Propylene Glycol Methyl Ether Acetate, 1-Methoxy-2-Propanol) Acetate) Thinner composed of 30% by weight is used.

The waste liquid of the thinner for semiconductors is being discharged enormously from the semiconductor industry, and when the waste liquid of the thinner is discarded, it pollutes the environment and has an uneconomical problem.

On the other hand, such waste liquids of thinner, as well as the above-mentioned PGME and PGMEA, 2-Hydroxyisobutyric acid methyl ester (HBM), Ethyl lactate (EL), Methyl Amyl Ketone (MAK), Cyclohexanone (GBL), γ-Butyrolactone GBL ), EEP (Ethyl 3-ethoxypropionate), DPE (Diisopentyl Ether), and water.

In order to recover the thinner components contained in the thinner waste liquid, Korean Patent Registration No. 10-1939811 (registered on January 11, 2019) discloses a method for purifying thinner waste liquid, but the cyclohexanone (Cyclohexanone) ) Was not removed at all.

Republic of Korea Registered Patent No. 10-1939811 (Jan. 2019.

In one aspect, the present invention is to provide a method for purifying a thinner waste liquid to remove cyclohexanone (MAC) and methyl amyl ketone (MAK) from thinner waste liquid used in a rinse process for cleaning a photoresist during a semiconductor manufacturing process in one aspect. .

In another aspect, the present invention is to provide a thinner composition obtained from the method for purifying thinner waste liquid according to the present invention.

In one embodiment of the present invention, a) a reduction step of reducing the ketone compound contained in the thinner waste solution to an alcohol compound by reacting the thinner waste solution with a reducing agent; b) The thinner waste liquid obtained in the reduction step is introduced into a primary distillation column to remove high boiling point impurities and nonvolatile ionic impurities having a higher boiling point than the thinner compound to the lower portion of the primary distillation column, and distillate of the remaining components is A primary recovery step of recovering to the top of the primary distillation column; c) The distillate recovered in the first recovery step is introduced into a second distillation column in a continuous process to remove low-boiling impurities having a lower boiling point than the compound for thinner to the upper portion of the second distillation column, and the organic solvent mixture of the remaining components is added to the second. A second recovery step of recovering to the bottom of the secondary distillation column; And d) the organic solvent mixture recovered in the second recovery step is introduced into a tertiary distillation column in a continuous process to remove residual high boiling point impurities having a higher boiling point than the compound for thinner and lower the third distillation column and thinner of the remaining components. It may provide a method for purifying the thinner waste solution comprising a third recovery step of recovering the thinner composition containing the solvent compound to the upper portion of the third distillation column.

In the method for purifying thinner waste liquid according to another embodiment of one aspect of the present invention, the reducing agent in the reduction step a) may be SBH (Sodium borohydride, NaBH ₄ ).

In the method for purifying thinner waste liquid according to another embodiment of one aspect of the present invention, the first recovery step b) is carried out in the primary distillation column at a pressure of 60 to 160 mmHg, and the distillate having a boiling point of 40 to 100 ° C at the top of the distillation column It may be a step of recovering.

In the method for purifying thinner waste liquid according to another embodiment of one aspect of the present invention, the second recovery step c) is performed in the second distillation column at a pressure of 60 to 160 mmHg, and a low boiling point impurity having a boiling point of 40 to 65 ° C. to the top of the distillation column. And removing the organic solvent mixture of the remaining components to the bottom of the second distillation column.

In the method for purifying thinner waste liquid according to another embodiment of one aspect of the present invention, the third recovery step d) is performed in the third distillation column at a pressure of 60 to 160 mmHg, for thinner having a boiling point of 60 to 90 ° C. to the top of the distillation column. It may be a step of recovering the thinner composition comprising the compound.

In a method of purifying thinner waste according to another embodiment of one aspect of the present invention, the thinner waste is PGME (Propylene Glycol Methyl Ether, 1-Methoxy-2-Propanol), HBM (2-Hydroxyisobutyric Acid Methyl Ester), PGMEA (Propylene Glycol Methyl Ether Acetate, 1-Methoxy-2-Propanol Acetate), EL (Ethyl Lactate), MAK (Methyl Amyl Ketone), Cyclohexanone, GBL (γ-Butyrolactone), EEP (Ethyl 3-Ethoxypropionate) ), DPE (Diisopentyl Ether) and other indivisible impurities.

In a method for purifying thinner waste liquid according to another embodiment of one aspect of the present invention, the thinner composition may be characterized by not containing MAK (Methyl Amyl Ketone) and cyclohexanone.

In a method for purifying thinner waste according to another embodiment of one aspect of the present invention, the thinner composition is PGME (Propylene Glycol Methyl Ether, 1-Methoxy-2-Propanol), HBM (2-Hydroxyisobutyric Acid Methyl Ester), PGMEA (Propylene Glycol Methyl Ether Acetate, 1-Methoxy-2-Propanol Acetate) and EL (Ethyl Lactate).

In the method for purifying thinner waste liquid according to another embodiment of one aspect of the present invention, the thinner waste liquid may be characterized in that waste liquid of thinner used in a rinse process for cleaning photoresist during a semiconductor manufacturing process is used.

The present invention may include a thinner composition obtained from a method for purifying thinner waste liquid according to any one embodiment of the present invention in one embodiment of another aspect.

The method for purifying the thinner waste liquid according to the present invention can be reused by recovering the waste liquid of the thinner used in the rinsing process to clean the photoresist during the semiconductor manufacturing process and removing cyclohexanone (MAC) and methyl amyl ketone (MAK) therefrom. A thinner composition can be provided.

1 is a schematic diagram of a process used in a method for purifying thinner waste liquid according to one aspect of the present invention.
Figure 2 is a GC analysis results for confirming the composition of the thinner waste liquid used in the method of purifying thinner waste liquid according to one aspect of the present invention.
3 is a GC analysis result for confirming the composition of the thinner waste solution after removing cyclohexanone and MAK by adding SBH to the thinner waste solution according to one embodiment of the present invention.
4 is a GC analysis result of the thinner composition obtained from the upper portion of the third distillation column by continuously operating three distillation columns after removing cyclohexanone and MAK from the thinner waste solution according to one embodiment of the present invention.
5 is a GC analysis result of the thinner composition obtained from the upper portion of the third distillation column by continuously operating three distillation columns without thinner waste SBH treatment.

The present invention relates to a thinner waste liquid purification method for purifying a thinner waste liquid used in a rinsing process for cleaning a photoresist during a semiconductor manufacturing process through a reduction step, and a thinner composition obtained therefrom.

Hereinafter, a method for purifying thinner waste liquid according to the present invention and a thinner composition obtained therefrom will be described in detail with reference to the accompanying drawings. Unless otherwise specified, all terms in this specification are the same as the general meaning of the term understood by a person skilled in the art to which the present invention belongs, and if there is a conflict with the meaning of the term used in the present specification, It follows the definition used in the specification. Throughout the specification, when a part “includes” a certain component, it means that the component may further include other components, not to exclude other components, unless otherwise stated.

As described above, the waste liquid of thinner is not only PGME (boiling point 120 ° C) and PGMEA (boiling point 146 ° C), but also HBM (2-Hydroxyisobutyric acid methyl ester, boiling point 137 ° C), EL (Ethyl lactate, boiling point 154 ° C), MAK (Methylethyl) Amyl Ketone, boiling point 149 ℃), cyclohexanone (Cyclohexanone, boiling point 155 ℃), GBL (γ-Butyrolactone, boiling point 204 ℃), EEP (Ethyl 3-ethoxypropionate, boiling point 170 ℃), DPE (Diisopentyl Ether, 173 ℃) And water (boiling point 100 ° C) and the like (where all the boiling points are 1 atm, boiling point at 760 mmHg).

PGME

PGMEA

HBM

EL

Cyclohexanone

GBL

EEP

DPE

In this way, the waste liquid composition of the thinner generated in the rinsing process for cleaning the photoresist during the semiconductor manufacturing process contains cyclohexanone and MAK, which are controlled substances, so that these compounds can be removed and recycled in the rinse process of the display manufacturing process. When fractional distillation using a difference in boiling point is applied to recover PGME, HBM, PGMEA, and EL that can be used in a thinner composition with high purity, there is a problem that it is difficult to remove cyclohexanone and MAK.

In order to solve this problem, a method for purifying thinner waste liquid according to one embodiment of one aspect of the present invention comprises: a) reducing the ketone compound contained in the thinner waste liquid with an alcohol compound by reacting the thinner waste liquid with a reducing agent. step; b) The thinner waste liquid obtained in the reduction step is introduced into a primary distillation column to remove high boiling point impurities and nonvolatile ionic impurities having a higher boiling point than the thinner compound to the lower portion of the primary distillation column, and distillate of the remaining components is A primary recovery step of recovering to the top of the primary distillation column; c) The distillate recovered in the first recovery step is introduced into a second distillation column in a continuous process to remove low-boiling impurities having a lower boiling point than the compound for thinner to the upper portion of the second distillation column, and the organic solvent mixture of the remaining components is added to the second. A second recovery step of recovering to the bottom of the secondary distillation column; And d) the organic solvent mixture recovered in the second recovery step is introduced into a tertiary distillation column in a continuous process to remove residual high boiling point impurities having a higher boiling point than the compound for thinner and lower the third distillation column and thinner of the remaining components. It may include; a third recovery step of recovering the thinner composition containing the molten compound to the upper portion of the third distillation column.

The method for purifying thinner waste liquid according to one embodiment of the present invention may include a) reducing a ketone compound contained in thinner waste liquid with an alcohol compound by reacting thinner waste liquid with a reducing agent.

As described above, the waste liquid of thinner is not only PGME (boiling point 120 ° C) and PGMEA (boiling point 146 ° C), but also HBM (2-Hydroxyisobutyric acid methyl ester, boiling point 137 ° C), EL (Ethyl lactate, boiling point 154 ° C), MAK (Methylethyl) Amyl Ketone, boiling point 149 ℃), cyclohexanone (Cyclohexanone, boiling point 155 ℃), GBL (γ-Butyrolactone, boiling point 204 ℃), EEP (Ethyl 3-ethoxypropionate, boiling point 170 ℃), DPE (Diisopentyl Ether, 173 ℃) And water (boiling point 100 ° C) and the like (where all the boiling points are 1 atm, boiling point at 760 mmHg). Therefore, when fractional distillation to be separated using a difference in boiling point is applied, the compound to be removed is PGMEA (a compound to be recovered for the boiling points of MAK (Methyl Amyl Ketone, boiling point 149 ° C) and cyclohexanone (Cyclohexanone, boiling point 155 ° C), which are compounds to be removed. The boiling point is similar to the boiling point of 146 ° C) and EL (Ethyl lactate, boiling point 154 ° C), and there is a problem that they are not separated.

Therefore, in the purification method of the thinner waste liquid according to the present invention, a reduction step of reducing the ketone compound contained in the thinner waste liquid to an alcohol compound by reacting the thinner waste liquid and a reducing agent may be performed. For example, reducing MAK (Methyl Amyl Ketone, boiling point 149 ℃) using a reducing agent results in 2-heptanol (2-Heptanol, boiling point 159 ℃) and reducing cyclohexanone (Cyclohexanone, boiling point 155 ℃) using a reducing agent. This gives cyclohexanol (boiling point 162 ° C) (both boiling point is 1 atm and boiling point at 760 mmHg). When the ketone compound contained in the waste solution is reduced to an alcohol compound having a higher boiling point using a reducing agent in this way, the difference in boiling point from the compound for thinner to be recovered is large, so that it can be separated using fractional distillation.

2-heptanol

Cyclohexanol

In general, the reaction for reducing a ketone compound to an alcohol compound using a reducing agent is shown in Reaction Scheme 1 below.

[Scheme 1]

(Where R ¹ and R ² are each C ₁ to C ₁₀ alkyl or R ¹ and R ² are alkylene structures connected to each other)

Meanwhile, in another embodiment of the present invention, SBH (Sodium borohydride, NaBH ₄ ) may be used as the reducing agent in the reduction step a).

Reducing agent commonly used may include _{LAH (Lithium aluminium hydride, LiAlH 4} ) and _{SBH (Sodium borohydride, NaBH 4)} . LAH is a very powerful reducing agent and is difficult to handle and has a wide reaction range, so it can reduce various functional groups. On the other hand, SBH, which is less reactive, is a reducing agent that is convenient to use and has high selectivity. Comparing SBH and LAH can be shown in Table 1 below.

[Table 1] Comparison of reduction reaction by SBH and LAH

Therefore, when LAH is used as the reducing agent in the present invention, even the ester compound can be reduced to alcohol, so in the present invention, SBH is used as the reducing agent.

The SBH used in one embodiment of the present invention may be 0.05 to 1.0% by weight, preferably 0.3 to 0.5% by weight, based on the total weight of the thinner waste liquid.

Meanwhile, the reaction according to Reaction Scheme 1 may be performed at a temperature of 5 to 100 ° C, preferably at a temperature of 25 to 100 ° C.

In addition, the reaction according to Reaction Scheme 1 may be carried out for a reaction time of 1 to 60 minutes, preferably 10 to 30 minutes.

The method for purifying the thinner waste liquid according to one embodiment of the present invention also b) the thinner waste liquid obtained in the reduction step is introduced into the primary distillation column to have high boiling point impurities and non-volatile ionics having a higher boiling point than the thinner compound. A first recovery step of removing impurities to the bottom of the primary distillation column and recovering distillates of the remaining components to the upper portion of the primary distillation column; c) The distillate recovered in the first recovery step is introduced into a second distillation column in a continuous process to remove low-boiling impurities having a lower boiling point than the compound for thinner to the upper portion of the second distillation column, and the organic solvent mixture of the remaining components is added to the second. A second recovery step of recovering to the bottom of the secondary distillation column; And d) the organic solvent mixture recovered in the second recovery step is introduced into a tertiary distillation column in a continuous process to remove residual high boiling point impurities having a higher boiling point than the compound for thinner and lower the third distillation column and thinner of the remaining components. It may include a third recovery step of recovering the thinner composition containing the molten compound to the top of the third distillation column.

This will be described in more detail with reference to FIG. 1.

1 is a schematic diagram of a process used in a method for purifying thinner waste liquid according to one aspect of the present invention.

Referring to Figure 1, the method of purifying the thinner waste liquid according to an embodiment of the present invention is a thinner waste solution obtained by reducing the ketone compound to an alcohol compound in the reduction step to the primary distillation column 101 to have a higher boiling point than the thinner compound. The branch may include a primary recovery step of removing high boiling point impurities and nonvolatile ionic impurities to the lower portion of the primary distillation column 101 and recovering distillates of the remaining components to the upper portion of the primary distillation column 101. In this case, the first recovery step may be a step of recovering distillate having a boiling point of 40 to 100 ° C at the top of the distillation column, performed in the primary distillation column at a pressure of 60 to 160 mmHg. Here, since the thinner waste liquid is fractionally distilled while maintaining the pressure of the primary distillation column 101 at 60 to 160 mmHg, distillate having a boiling point of 40 to 100 ° C can be recovered to the top of the distillation column.

In addition, the method of purifying the thinner waste liquid according to the embodiment of the present invention, the distillate recovered in the first recovery step is introduced into the secondary distillation column 102 in a continuous process to remove low-boiling impurities having a lower boiling point than the thinner compound. A second recovery step of removing the upper portion of the secondary distillation column 102 and recovering the organic solvent mixture of the remaining components to the lower portion of the secondary distillation column 102 may be included. At this time, the second recovery step is performed in the second distillation column at a pressure of 60 to 160 mmHg to remove low-boiling impurities having a boiling point of 40 to 65 ° C to the top of the distillation column and recovering the organic solvent mixture of the remaining components to the bottom of the second distillation column. Can be. Here, since the thinner waste liquid is fractionally distilled while maintaining the pressure of the secondary distillation column 102 at 60 to 160 mmHg, low boiling point impurities having a boiling point of 40 to 65 ° C can be removed to the upper portion of the distillation column.

In addition, the method of purifying the thinner waste liquid according to the embodiment of the present invention, the organic solvent mixture recovered in the second recovery step is introduced into the tertiary distillation column 103 in a continuous process to have a higher boiling point than the compound for thinner, and a high boiling point remaining It may include a third recovery step of removing the impurities to the lower portion of the third distillation column (103) and recovering the thinner composition containing the compound for thinner of the remaining components to the upper portion of the third distillation column (103). In this case, the third recovery step may be a step of recovering a thinner composition containing a compound for thinner having a boiling point of 60 to 90 ° C., performed in the third distillation column at a pressure of 60 to 160 mmHg. Here, since the thinner waste liquid is fractionally distilled while maintaining the pressure of the third distillation column 103 at 60 to 160 mmHg, a thinner composition containing a compound for thinner having a boiling point of 60 to 90 ° C can be recovered to the top of the distillation column. By performing the third recovery step, it is possible to remove high boiling point impurities remaining in the thinner waste liquid after the first recovery step.

In another embodiment of the present invention, the thinner waste liquid used in the method for purifying thinner waste liquid is PGME (Propylene Glycol Methyl Ether, 1-Methoxy-2-Propanol), HBM (2-Hydroxyisobutyric Acid Methyl Ester), PGMEA (Propylene Glycol) Methyl Ether Acetate, 1-Methoxy-2-Propanol Acetate), EL (Ethyl Lactate), MAK (Methyl Amyl Ketone), Cyclohexanone (GBL), γ-Butyrolactone (GBL), Ethyl 3-Ethoxypropionate (EPE), DPE (Diisopentyl Ether) and other indivisible impurities.

In another embodiment of the present invention, the thinner composition recovered in the third recovery step may be characterized in that it does not include MAK (Methyl Amyl Ketone) and cyclohexanone (Cyclohexanone). As described above, the method for purifying the thinner waste liquid according to the present invention converts the ketone compound contained in the thinner waste liquid into alcohol using a reducing agent and then removes the used substances, thereby limiting the use of MAK (Methyl Amyl Ketone) and cyclohexanone ( The thinner composition for reuse, which is finally recovered by removing cyclohexanone), may not include Methyl Amyl Ketone (MAK) and Cyclohexanone.

In another embodiment of the present invention, the thinner composition recovered in the third recovery step is PGME (Propylene Glycol Methyl Ether, 1-Methoxy-2-Propanol), HBM (2-Hydroxyisobutyric Acid Methyl Ester), PGMEA (Propylene Glycol) Methyl Ether Acetate, 1-Methoxy-2-Propanol Acetate) and EL (Ethyl Lactate). In the method for purifying thinner waste liquid according to the present invention, the thinner waste liquid used in the semiconductor manufacturing process is purified, and the compound for thinner contained in the thinner waste liquid is recovered and reused. In the method for purifying thinner waste liquid according to the present invention, The thinner composition that is finally recovered includes the recyclable compound for thinner, PGME (Propylene Glycol Methyl Ether, 1-Methoxy-2-Propanol), HBM (2-Hydroxyisobutyric Acid Methyl Ester), PGMEA (Propylene Glycol Methyl Ether Acetate, 1- Methoxy-2-Propanol Acetate) and EL (Ethyl Lactate).

In another embodiment of the present invention, the thinner waste liquid used in the method of purifying the thinner waste liquid according to the present invention may be used as a thinner waste liquid used in a rinsing process for cleaning a photoresist during a semiconductor manufacturing process. As described above, these thinner waste liquids include PGME (Propylene Glycol Methyl Ether, 1-Methoxy-2-Propanol), HBM (2-Hydroxyisobutyric Acid Methyl Ester), PGMEA (Propylene Glycol Methyl Ether Acetate, 1-Methoxy-2-Propanol) Contains Acetate), EL (Ethyl Lactate), MAK (Methyl Amyl Ketone), Cyclohexanone (GBL), γ-Butyrolactone (GBL), Ethyl 3-Ethoxypropionate (EEP), Diisopentyl Ether (DPE) and other indivisible impurities can do.

The present invention may provide a thinner composition obtained from the method for purifying thinner waste liquid according to the present invention in one embodiment of another aspect. The thinner composition according to another aspect of the present invention does not include Methyl Amyl Ketone (MAK) and Cyclohexanone, and PGME (Propylene Glycol Methyl Ether, 1-Methoxy-2-Propanol), HBM (2- Hydroxyisobutyric Acid Methyl Ester), PGMEA (Propylene Glycol Methyl Ether Acetate, 1-Methoxy-2-Propanol Acetate) and EL (Ethyl Lactate).

Hereinafter, the present invention will be described in more detail through examples. However, these are only for explaining the present invention in more detail, and the scope of the present invention is not limited thereto.

Example

<Examples 1 to 6>

1) reduction step of ketone compound

Cyclohexanone and MAK were converted to cyclohexanol and 2-heptanol in the following manner by adding SBH to the waste solution of the thinner used in the semiconductor manufacturing process as in the following example.

200 g of thinner waste liquid was added to a 500 mL round-bottom flask, and while stirring at 200 to 250 rpm at 25 to 100 ° C, SBH was temporarily added to the thinner waste liquid, stirred for 10 to 30 minutes, and the degree of completion of the reaction was GC (Gas Chromatography). ) Analysis.

The composition of the thinner waste solution and the thinner waste solution after the reaction are shown in Table 2 below.

[Table 2]

According to Table 2, it can be confirmed that MAK and cyclohexanone contained in the thinner waste liquid were converted to 2-heptanol and cyclohexanol, respectively, by reaction with SBH.

2) distillation column

As described above, the thinner waste solution reduced using SBH was purified using a distillation column.

Specifically, first, the thinner waste solution reduced using SBH in Example 2 was introduced into the primary distillation column at a pressure of 60 to 160 mmHg, and the distillate was recovered from the upper portion of the primary distillation column when the temperature reached 40 ° C. Distillate was recovered until it reached 100 ° C.

Thereafter, the distillate recovered from the upper portion of the primary distillation column was introduced into the secondary distillation column at a pressure of 60 to 160 mmHg in a continuous process, and the distillate was discharged from the upper portion of the secondary distillation column at a temperature of 40 ° C. The distillate was discharged until.

Thereafter, the organic solvent mixture recovered from the lower portion of the secondary distillation column was introduced into the tertiary distillation column at a pressure of 60 to 160 mmHg in a continuous process, and the distillate was recovered from the upper portion of the tertiary distillation column at a temperature of 60 ° C. The distillate was recovered until it reached ℃.

The composition of the components in the thinner waste liquid that has been subjected to the distillation step in each distillation column is shown in Table 3 below.

[Table 3]

According to Table 3, it can be seen that the thinner composition finally obtained to the top of the third distillation column contains PGME, HBM, EL, and PGMEA and contains a small amount of DPE, while MAK and cyclohexanone, and each of them It can be seen that the converted 2-heptanol and cyclohexanol are not included.

Comparative example

Table 4 below shows the results of fractional distillation using a distillation column without applying the reduction reaction of ketone using SBH to the waste liquid of the thinner used in the semiconductor manufacturing process.

[Table 4]

As shown in Table 4, it can be confirmed that MAK and cyclohexanone were not removed from the distillate finally recovered to the top of the third distillation column.

The above description is merely illustrative of the present invention, and those skilled in the art to which the present invention pertains will be capable of various modifications without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed herein are not intended to limit the present invention, but to explain the present invention, and the spirit and scope of the present invention are not limited by these embodiments. The scope of protection of the present invention should be interpreted by the claims below, and all technologies within the equivalent range should be interpreted as being included in the scope of the present invention.

Claims (10)

a) a reduction step of reducing the ketone compound contained in the thinner waste solution to an alcohol compound by reacting the thinner waste solution with NaBH ₄ (Sodium borohydride, hereinafter referred to as 'SBH');
The thinner waste is 2-Hydroxyisobutyric Acid Methyl Ester (hereinafter referred to as 'HBM'), Propylene Glycol Methyl Ether Acetate (hereinafter referred to as 'PGMEA'), Ethyl Lactate (hereinafter referred to as 'EL'), Methyl Amyl Ketone (hereinafter referred to as 'MAK') ') And cyclohexanone,
Cyclohexanone in the thinner waste solution is reacted with SBH to convert to cyclohexanol, and MAK is reacted with SBH to convert to 2-heptanol;
b) a first recovery step of recovering distillate to the top of the primary distillation column by introducing the thinner waste liquid obtained in the reduction step to the primary distillation column, wherein the distillate is HBM, PGMEA, EL, 2-heptanol and Cyclohexanol;
c) a second recovery step of recovering the organic solvent mixture to the bottom of the secondary distillation column by introducing distillate recovered to the upper portion of the primary distillation column into a secondary distillation column in a continuous process, wherein the organic solvent mixture is HBM, PGMEA, EL, 2-heptanol and cyclohexanol; And
d) a third recovery step of recovering the thinner composition to the top of the third distillation column by introducing the organic solvent mixture recovered from the bottom of the second distillation column into the third distillation column in a continuous process, wherein the thinner composition comprises HBM, PGMEA and EL. Included, 2-heptanol and cyclohexanol are removed to the bottom of the third distillation column,
The thinner composition is a method for purifying thinner waste liquid, characterized in that it does not contain MAK and cyclohexanone. According to claim 1,
The primary recovery step b) is a purification method of thinner waste liquid, characterized in that it is carried out in the primary distillation column having a pressure of 60 to 160 mmHg to recover distillate having a boiling point of 40 to 100 ° C to the top of the distillation column. According to claim 1,
The second recovery step c) is performed in the secondary distillation column at a pressure of 60 to 160 mmHg to remove impurities having a boiling point of 40 to 65 ° C. to the top of the distillation column and recover the organic solvent mixture of the remaining components to the lower portion of the secondary distillation column. Characterized by a method for purifying thinner waste liquid. According to claim 1,
The third recovery step d) is performed in the third distillation column at a pressure of 60 to 160 mmHg to recover the thinner composition having a boiling point of 60 to 90 ° C. to the top of the distillation column. According to claim 1,
The thinner waste liquid of step a) further includes γ-Butyrolactone (hereinafter referred to as 'GBL') and Ethyl 3-ethoxypropionate (hereinafter referred to as 'EEP'),
The GBL and EEP method of purifying thinner waste liquid, characterized in that is removed to the bottom of the third distillation column. According to claim 1,
The amount of SBH used in the reduction step is a method of purifying thinner waste liquid, characterized in that 0.05 to 1.0% by weight based on the weight of the thinner waste liquid as a reactant. According to claim 1,
The reaction in the reduction step is a method of purifying thinner waste liquid, characterized in that is carried out at 5 ~ 100 ℃. According to claim 1,
The reaction in the reduction step is a method for purifying thinner waste liquid, characterized in that is carried out for a reaction time of 1 to 60 minutes. According to claim 1,
The thinner waste liquid is a thinner waste liquid purification method used in the rinsing process for cleaning the photoresist during the semiconductor manufacturing process. The thinner composition obtained from the method for purifying the thinner waste solution according to any one of claims 1 to 9.

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