Method for purifying organic solvents

Abstract

The present invention provides a method for purifying an organic solvent, characterized by having a first processing step for bringing an organic solvent to be processed into contact with an H-form cation exchanger (1), and a second processing step for bringing the process liquid of the first processing step into contact with an anion exchanger (2) and an H-form strongly acidic cation exchanger (3). Through the present invention, it is possible to provide a method for purifying an organic solvent having excellent ability to remove metal impurities involving both monovalent and polyvalent metals from an organic solvent, and to provide a device for purifying an organic solvent.

Description

[Technical field]

[0001] The present invention relates to a method for purifying an organic solvent to obtain a high-purity organic solvent having a reduced content of impurity metals. To Regarding. [Background technology]

[0002] In the semiconductor manufacturing process, metal impurities contained in isopropyl alcohol (IPA) used for cleaning are likely to have adverse effects on wafers, so the impurity content in IPA must be reduced to the ppt level.

[0003] Methods for removing metal impurities from organic solvents and purifying the organic solvent include methods using ion exchangers, and it is known that metal impurities in organic solvents can be reduced to the ppt level by using ion exchangers having strongly acidic cation exchange groups, such as ion exchange resins and ion adsorption membranes.

[0004] For example, Patent Document 1 discloses a method for producing high-purity isopropanol having a metal content of less than 1 ppb and a water content of less than 100 ppm, the method comprising the steps of: (a) supplying a feed stream containing at least 99.9% by weight of isopropyl alcohol, containing 200 to 500 ppm of organic impurities and having a water content of 100 ppm or less to a separation tower; (b) separating the feed stream into a top stream collected from an upper portion of the separation tower and containing concentrated components having a boiling point lower than that of isopropyl alcohol, and a bottom stream collected from the bottom of the separation tower and containing concentrated components having a boiling point higher than that of isopropyl alcohol. (c) obtaining the high purity isopropyl alcohol as a vapor side stream at a point: (i) below where the feed stream enters the separation tower and above where the bottoms stream is high purity isopropyl alcohol having a metal content of less than 1 ppb and a water content of less than 100 ppm; or (ii) above where the feed stream enters the separation tower and below where the heads stream is high purity isopropyl alcohol. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 2003-535836 DISCLOSURE OF THEINVENTION [Problem to be solved by the invention]

[0006] However, since the diffusion rate of metal impurities is low in organic solvents and the reaction rate of the ion exchange reaction with ion exchange resins is also low, when removing ionic impurities in organic solvents, the flow rate through the ion exchange resin is set to be lower than when removing ionic impurities in aqueous solutions. For example, when treating with a strongly acidic cation exchange resin, it is difficult to obtain the same metal removal rate at the same flow rate as in water.

[0007] The present inventors have confirmed that it is difficult to reduce all of the metals in a solvent such as IPA using a strongly acidic cation exchanger, and that there are metals such as Cr and As that are particularly poorly removed.

[0008] Therefore, an object of the present invention is to provide a method for purifying an organic solvent, which is excellent in removing metal impurities from both monovalent and polyvalent metal species in the organic solvent. of The purpose is to provide. [Means for solving the problem]

[0009] In light of this technical background, the present inventors have conducted extensive research and have found that (1) the removal rate of divalent or higher metals such as Cr is poor when using a strongly acidic cation exchange resin, and that some of these metals may exist in an anionic form in organic solvents, and that the use of an H-type chelate exchanger is effective for removing these metals; further, when an H-type chelate exchanger is used, a new problem occurs in that trace amounts of mineral acids such as hydrochloric acid present in the H-type chelate exchanger are transferred to the treatment liquid, resulting in the treatment liquid containing mineral acids derived from the H-type chelate exchanger; and In order to solve this problem, the inventors have found that it is effective to treat the treatment solution of an H-type chelate exchanger with an anion exchanger and a strongly acidic ion exchanger, and that (2) after first removing monovalent and divalent or higher metals in an organic solvent with an H-type strongly acidic cation exchanger, further treating the solution with an anion exchanger and an H-type strongly acidic ion exchanger makes it possible to remove metals such as Cr in an anion form with the anion exchanger, and then to bring the solution into contact with a strongly acidic ion exchanger again, thereby effectively removing monovalent and divalent or higher metals that were not completely removed in the previous step. Based on these findings, the inventors have completed the present invention.

[0010] That is, the present invention (1) is The content of each metal impurity in the organic solvent to be treated is 100 mass ppb to 20 mass ppt. a first treatment step in which the organic solvent to be treated is brought into contact with an H-type chelate exchanger; The processing solution of the first processing step, OH type strong basicity a second treatment step in which the eluate is contacted with an anion exchanger (2) and a strongly acidic cation exchanger in the H-form (3); Have the resulting purified organic solvent is used in a semiconductor manufacturing process or for trace metal analysis, and each metal content in the resulting purified organic solvent is 10 ppt by mass or less; The functional group of the H-type chelating exchanger is an iminodiacetic acid group, an aminomethylphosphate group, or an iminopropionic acid group. The present invention provides a method for purifying an organic solvent, comprising the steps of: The present invention (2) also provides The content of each metal impurity in the organic solvent to be treated is 100 mass ppb to 20 mass ppt. a first treatment step in which the organic solvent to be treated is brought into contact with an H-type strongly acidic cation exchanger; The processing solution of the first processing step, OH type strong basicity a second treatment step in which the eluate is contacted with an anion exchanger (2) and a strongly acidic cation exchanger in the H-form (3); Have The resulting purified organic solvent is used in a semiconductor manufacturing process or for trace metal analysis, and each metal content in the resulting purified organic solvent is 10 ppt by mass or less. The present invention provides a method for purifying an organic solvent, comprising the steps of:

[0011] In addition, the present invention (3) is characterized in that the processing solution of the first processing step is OH type strong basicity The present invention provides a method for purifying an organic solvent according to (1) or (2), characterized in that the second treatment step is carried out by passing the organic solvent through a mixed bed of an anion exchanger (2) and the H-type strongly acidic cation exchanger (3).

[0012] In addition, the present invention (4) is a method for preparing a processing solution of the first processing step by OH type strong basicity The present invention provides a method for purifying an organic solvent according to (1) or (2), characterized in that the second treatment step is carried out by contacting the organic solvent with an anion exchanger (2) and then with the H-form strongly acidic cation exchanger (3).

[0017] In addition, the present invention ( 5 ) is the ratio of the volume of the H-type chelating exchanger to the volume of the H-type chelating exchanger. OH type strong basicity The volume ratio of the anion exchanger is 0.1 to 99.0% by volume (1). of A method for purifying an organic solvent is provided.

[0018] The present invention (6) is characterized in that the ratio of the volume of the H-type strongly acidic cation exchanger to the volume of the H-type chelate exchanger is 0.1 to 99.0 volume % (1). Or (5) The present invention provides a method for purifying an organic solvent.

[0019] In addition, the present invention ( 7 ) is characterized in that the organic solvent is a polar organic solvent (1) to ( 6 The present invention provides a method for producing any one of the organic solvents described above. Effect of the Invention

[0023] According to the present invention, a purification method excellent in removing metal impurities from both monovalent and polyvalent metal species in an organic solvent is provided. of can be provided. [Brief description of the drawings]

[0024] [Figure 1] FIG. 2 is a schematic flow chart showing a first embodiment of the second treatment step of the method for purifying an organic solvent according to the first or second embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic flow chart showing a second embodiment of the second treatment step in the method for purifying an organic solvent according to the first or second embodiment of the present invention. [Diagram 3] FIG. 2 is a schematic flow chart showing a third embodiment of the second treatment step in the method for purifying an organic solvent according to the first or second embodiment of the present invention. [Figure 4] FIG. 2 is a schematic flow chart showing a fourth embodiment of the second treatment step of the method for purifying an organic solvent according to the first or second embodiment of the present invention. [Diagram 5] FIG. 1 is a schematic flow chart showing a fifth embodiment of the second treatment step of the method for purifying an organic solvent according to the first or second embodiment of the present invention. [Figure 6] FIG. 2 is a schematic flow diagram showing a method for purifying an organic solvent according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] The method for purifying an organic solvent according to the first embodiment of the present invention comprises a first treatment step of contacting the organic solvent to be treated with an H-type chelate exchanger (1a), a second treatment step in which the treated liquid from the first treatment step is contacted with an anion exchanger (2) and an H-type strongly acidic cation exchanger (3); The method for purifying an organic solvent is characterized by comprising the steps of:

[0026] The first treatment step in the method for purifying an organic solvent according to the first embodiment of the present invention is a step of contacting the organic solvent to be treated with an H-type chelate exchanger (1a).

[0027] The organic solvent to be treated in the first embodiment of the method for purifying an organic solvent of the present invention is not particularly limited, and examples thereof include alcohols such as isopropyl alcohol, methanol, and ethanol, ketones such as cyclohexanenone, methyl isobutyl ketone, acetone, and methyl ethyl ketone, alkene-based organic solvents such as 2,4-diphenyl-4-methyl-1-pentene and 2-phenyl-1-propene, N-methylpyrrolidone, and mixed organic solvents thereof. The organic solvent to be treated may be either a polar organic solvent or a non-polar organic solvent, and a polar organic solvent is preferred. The polar organic solvent may be a protic polar organic solvent or an aprotic organic solvent.

[0028] The organic solvent to be treated contains, as metal impurities, both monovalent metals such as Na, K, and Li, and divalent or higher metals such as Cr, As, Ca, Cu, Fe, Mg, Mn, Ni, Pb, and Zn, which are easily removed with a chelating resin.

[0029] The content of each metal impurity in the organic solvent to be treated is not particularly limited, but is usually about 100 ppb by mass to 20 ppt by mass.

[0030] The H-type cation exchanger (1) in the method for purifying an organic solvent according to the first embodiment of the present invention is an H-type chelate exchanger (1a).

[0031] The H-form chelate exchanger (1a) is a chelate exchanger in a metal ion form, such as a Na-form, Ca-form, or Mg-form, which is converted to an H-form by contacting the chelate exchanger with a mineral acid and treating the chelate exchanger with the mineral acid. In other words, the H-form chelate exchanger (1a) is a mineral acid contact treatment product of a metal ion form chelate exchanger.

[0032] The functional group of the H-type chelate exchanger (1a) is not particularly limited as long as it can coordinate to a metal ion to form a chelate, and examples thereof include functional groups having an amino group such as iminodiacetic acid group, aminomethyl phosphate group, iminopropionic acid group, etc., and thiol group, etc. Among these, as the functional group of the chelate exchanger, functional groups having an amino group are preferred in terms of increasing the ability to remove many polyvalent metal ions, and iminodiacetic acid group, aminomethyl phosphate group, and iminopropionic acid group are particularly preferred.

[0033] The H-type chelate exchanger (1a) may be a granular H-type chelate exchange resin. The substrate of the H-type chelate exchange resin may be a styrene-divinylbenzene copolymer. The H-type chelate exchange resin may have any of a gel structure, a macroporous structure, and a porous structure. The exchange capacity of the H-type chelate exchange resin is preferably 0.5 to 2.5 eq / LR, and more preferably 1.0 to 2.5 eq / LR. The average particle size (harmonic mean diameter) of the H-type chelate exchange resin is not particularly limited, but is preferably 300 to 1000 μm, and more preferably 500 to 800 μm. The average particle size of the H-type chelate exchange resin is a value measured by a laser diffraction particle size distribution measuring device.

[0034] The H-type chelate exchanger (1a) may be an H-type organic porous chelate exchanger. The H-type organic porous chelate exchanger is an organic porous material into which a functional group having chelating ability, such as the functional groups having chelating ability listed above, has been introduced. The exchange capacity of the H-type organic porous chelate exchanger is preferably 0.3 to 2 mg equivalent / mL (water-wet state), particularly preferably 1 to 2 mg equivalent / mL (water-wet state).

[0035] The H-form chelate exchanger (1a) can be obtained by contacting a metal ion-form chelate exchanger such as a Na-form, Ca-form, or Mg-form with a mineral acid for acid treatment. Examples of the mineral acid to be contacted with the metal ion-form chelate exchanger include hydrochloric acid, sulfuric acid, and nitric acid. Of these, hydrochloric acid and sulfuric acid are preferred from the viewpoint of safety. In addition, in the case of conversion from a Ca-form, hydrochloric acid is preferred since there is a risk of calcium sulfate precipitation. The concentration of the mineral acid is preferably 0.1 to 6N, particularly preferably 1 to 4N.

[0036] The method for contacting the mineral acid with the metal ion type chelate exchanger is not particularly limited, and the contact mode, contact temperature, contact time, etc. may be appropriately selected.

[0037] After contacting the metal ion chelate exchanger with a mineral acid, the H-type chelate exchanger converted to H-type is washed with water to remove excess mineral acid, but since the functional groups in the chelate exchanger are bonded to the mineral acid by hydrogen bonds, etc., the excess mineral acid cannot be completely removed by washing with water. Therefore, the mineral acid used in the acid treatment remains in the H-type chelate exchanger.

[0038] For example, metal ion type chelate exchange resins include CR-10 and CR-11 manufactured by Mitsubishi Chemical Corporation, Duolite C-467 manufactured by Sumika Chemtex Corporation, MC-700 manufactured by Sumitomo Chemical Co., Ltd., Lewatit TP207, Lewatit TP208, and Lewatit TP260 manufactured by LANXESS AG, S930 and S950 manufactured by Purolite Corporation, and DS-21 and DS-22 manufactured by Organo Corporation.

[0039] In the first treatment step, the organic solvent to be treated is treated with the H-type chelate exchanger (1a) by contacting the organic solvent with the H-type chelate exchanger (1a), thereby removing mainly divalent or higher metals and some of the monovalent metals in the organic solvent to be treated.

[0040] In the first treatment step, the flow rate (SV) of the organic solvent to be treated through the H-type chelate exchanger (1a) is not particularly limited and may be appropriately selected, but is preferably 0.1 to 100 h -1, particularly preferably 2 to 30 hours -1 , more preferably 4 to 25 hours -1 It is.

[0041] In the first treatment step, the temperature at which the organic solvent to be treated is passed through the H-type chelate exchanger (1a) is not particularly limited and may be appropriately selected, but is usually 0 to 50° C. Depending on the type of the organic solvent to be treated, the organic solvent to be treated may be passed through the H-type chelate exchanger (1a) at 0 to 80° C. in the first treatment step.

[0042] The second treatment step in the method for purifying an organic solvent according to the first embodiment of the present invention is a step of contacting the treatment liquid from the first treatment step with an anion exchanger (2) and an H-form strongly acidic cation exchanger (3).

[0043] The anion exchanger (2) in the method for purifying an organic solvent according to the first embodiment of the present invention includes a strongly basic anion exchanger (2a) having a strongly basic anion exchange group as the anion exchange group, and a weakly basic anion exchanger (2b) having a weakly basic anion exchange group as the anion exchange group.

[0044] Examples of the strongly basic anion exchange group of the strongly basic anion exchanger (2a) include OH-type quaternary ammonium groups, etc. Examples of the weakly basic anion exchange group of the weakly basic anion exchanger (2b) include tertiary amino groups, secondary amino groups, primary amino groups, polyamine groups, etc.

[0045] The anion exchanger (2) in the method for purifying an organic solvent according to the first embodiment of the present invention may be a granular anion exchange resin. The substrate of the anion exchange resin is a styrene-divinylbenzene copolymer. The anion exchange resin may have any of a gel structure, a macroporous structure, and a porous structure. The ion exchange capacity of the anion exchange resin in a wet state is preferably 0.5 to 2 (eq / LR), particularly preferably 0.9 to 2 (eq / LR). The harmonic mean diameter of the anion exchange resin is preferably 400 to 900 μm, particularly preferably 500 to 800 μm. Examples of anion exchange resins include Amberlite IRA900, 402, 96SB, 98, Amberjet 4400, 4002, and 4010 manufactured by The Dow Chemical Company; Diaion UBA120, PA306S, PA308, PA312, PA316, PA318L, WA21J, and WA30 manufactured by Mitsubishi Chemical Corporation; DS-2, DS-5, and DS-6 manufactured by Organo Corporation; A400, A600, SGA550, A500, A501P, A502PS, A503, A100, A103S, A110, A111S, and A133S manufactured by Purolite Corporation; and Monoplus M500, M800, MP62WS, and MP64 manufactured by Lewatit.

[0046] The anion exchanger (2) may be an organic porous anion exchanger. The organic porous anion exchanger is an organic porous material into which an anion exchange group, such as the above-mentioned strongly basic anion exchange group or weakly basic anion exchange group, has been introduced. The exchange capacity of the organic porous anion exchanger is preferably 1 to 6 mg equivalent / mL (dry state), particularly preferably 2 to 5 mg equivalent / mL (dry state).

[0047] The H-form strongly acidic cation exchanger (3) in the method for purifying an organic solvent according to the first embodiment of the present invention is one in which strongly acidic cation exchange groups such as sulfonic acid groups have been converted to the H-form.

[0048] The H-type strongly acidic cation exchanger (3) may be a granular strongly acidic cation exchange resin. The substrate of the H-type strongly acidic cation exchange resin is a styrene-divinylbenzene copolymer. The H-type strongly acidic cation exchange resin may have any of a gel structure, a macroporous structure, and a porous structure. The ion exchange capacity of the H-type strongly acidic cation exchange resin in a wet state is preferably 1.5 to 3.0 (eq / LR), particularly preferably 1.7 to 2.7 (eq / LR). The harmonic mean diameter of the H-type strongly acidic cation exchange resin is preferably 400 to 900 μm, particularly preferably 500 to 800 μm. Examples of H-type strong acid cation exchange resins include Amberlite IR120B, IR124, 200CT252, Amberjet 1020, 1024, 1060, and 1220 manufactured by Dow Chemical Company; Diaion SK104, SK1B, SK110, SK112, PK208, PK212L, PK216, PK218, PK220, PK228, UBK08, UBK10, and UBK12 manufactured by Mitsubishi Chemical Corporation; DS-1 and DS-4 manufactured by Organo; C100, C100E, C120E, C100x10, C100x12MB, C150, C160, and SGC650 manufactured by Purolite Corporation; and Monoplus S108H, SP112, and S1668 manufactured by Lewatit Corporation.

[0049] The H-type strongly acidic cation exchanger (3) may be an H-type organic porous strongly acidic cation exchanger. The H-type organic porous strongly acidic cation exchanger is an organic porous material into which a strongly acidic cation exchange group, such as the strongly acidic cation exchange group listed above, has been introduced. The exchange capacity of the H-type organic porous strongly acidic cation exchanger is preferably 1 to 3 mg equivalent / mL (dry state), particularly preferably 1.5 to 3 mg equivalent / mL (dry state).

[0050] In the second treatment step, the treated liquid from the first treatment step is brought into contact with an anion exchanger (2) and an H-type strongly acidic cation exchanger (3) to treat the organic solvent to be treated with the anion exchanger (2) and the H-type strongly acidic cation exchanger (3), and the remainder of the monovalent metal that was not completely removed by the H-type chelate exchanger (1a) in the first treatment step and the mineral acid released from the H-type chelate exchanger (1a) are removed. In addition, NaOH is used as a regenerant to regenerate the anion exchanger, and if the anion exchanger is thoroughly washed after regeneration, NaOH hardly remains in the anion exchanger. In the second treatment step, even if the washing after regeneration of the anion exchanger (2) is poor and the residue of NaOH used as the regenerant is eluted from the anion exchanger (2), the H-type strongly acidic cation exchanger (3) in the second treatment step can remove Na. As the anion exchanger (2) and the H-type strongly acidic cation exchanger (3) to be contacted with the liquid to be treated in the second treatment step, the above-mentioned cation exchangers and anion exchangers may be mixed in any ratio, or an ion exchanger sold as a mixture of anion exchanger (2) and H-type strongly acidic cation exchanger (3) may be used. Examples of the mixture of anion exchanger (2) and H-type strongly acidic cation exchanger (3) include DS-3, DS-7, MSPS2-1·DRY, EG-4A-HG, EG-5A-HG, ESP-1, and ESP-2 manufactured by Organo, AmberTec UP6040 manufactured by DUPONT, and MB378, MB378LT, MB400, MB424, MB46, MB47 / 4914, and MB478 manufactured by Purolite.

[0051] In the second treatment step, the liquid passing speed (SV) when the treatment liquid of the first treatment step is passed through the anion exchanger (2) and the H-type strongly acidic cation exchanger (3) is not particularly limited and can be appropriately selected, but is preferably 0.1 to 100 h -1 , particularly preferably 2 to 50 hours -1 It is.

[0052] In the second treatment step, the temperature at which the treatment liquid from the first treatment step is passed through the anion exchanger (2) and the H-type strongly acidic cation exchanger (3) is not particularly limited and may be appropriately selected, but is usually 0 to 50° C. Depending on the type of organic solvent to be treated, the treatment liquid from the first treatment step may be passed through the anion exchanger (2) and the H-type strongly acidic cation exchanger (3) at 0 to 80° C. in the second treatment step. When the treatment liquid from the first treatment step is passed through the anion exchanger (2) and the H-type strongly acidic cation exchanger (3) at 60 to 80° C. in the second treatment step, if a strongly basic anion exchanger (2a) is used as the anion exchanger (2), the strongly basic anion exchanger (2a) is easily decomposed, so a weakly basic anion exchanger (2b) is used as the anion exchanger (2).

[0053] The method for purifying an organic solvent according to the second embodiment of the present invention comprises a first treatment step of contacting the organic solvent to be treated with an H-type strongly acidic cation exchanger (1b), a second treatment step in which the treated liquid from the first treatment step is contacted with an anion exchanger (2) and an H-type strongly acidic cation exchanger (3); The method for purifying an organic solvent is characterized by comprising the steps of:

[0054] The first treatment step in the method for purifying an organic solvent according to the second embodiment of the present invention is a step of contacting the organic solvent to be treated with a H-form strongly acidic cation exchanger (1b).

[0055] The organic solvent to be treated in the method for purifying an organic solvent of the second embodiment of the present invention is the same as the organic solvent to be treated in the method for purifying an organic solvent of the first embodiment of the present invention.

[0056] The H-form cation exchanger (1) in the method for purifying an organic solvent according to the second embodiment of the present invention is the H-form strongly acidic cation exchanger (1b). The H-form strongly acidic cation exchanger (1b) in the method for purifying an organic solvent according to the second embodiment of the present invention is the same as the H-form strongly acidic cation exchanger (3) in the method for purifying an organic solvent according to the first embodiment of the present invention.

[0057] In the first treatment step, the organic solvent to be treated is treated with an H-type strongly acidic cation exchanger (1b) by contacting the organic solvent with the H-type strongly acidic cation exchanger (1b) to remove a portion of the divalent or higher metals and a portion of the monovalent metals in the organic solvent to be treated.

[0058] In the first treatment step, the flow rate (SV) at which the organic solvent to be treated is passed through the H-type strongly acidic cation exchanger (1b) is not particularly limited and may be appropriately selected, but is preferably 0.1 to 100 h -1 , particularly preferably 2 to 30 hours -1 It is.

[0059] In the first treatment step, the temperature at which the organic solvent to be treated is passed through the H-type strongly acidic cation exchanger (1b) is not particularly limited and may be appropriately selected, but is usually 0 to 50° C. Depending on the type of the organic solvent to be treated, the organic solvent to be treated may be passed through the H-type strongly acidic cation exchanger (1b) at 0 to 80° C. in the first treatment step.

[0060] The second treatment step in the method for purifying an organic solvent according to the second embodiment of the present invention is a step in which the treatment liquid from the first treatment step is contacted with an anion exchanger (2) and an H-form strongly acidic cation exchanger (3).

[0061] The anion exchanger (2) used in the method for purifying an organic solvent according to the second embodiment of the present invention is the same as the anion exchanger (2) used in the method for purifying an organic solvent according to the first embodiment of the present invention, and the H-form strongly acidic cation exchanger (3) used in the method for purifying an organic solvent according to the second embodiment of the present invention is the same as the H-form strongly acidic cation exchanger (3) used in the method for purifying an organic solvent according to the first embodiment of the present invention.

[0062] In the second embodiment of the method for purifying an organic solvent of the present invention, the H-form strongly acidic cation exchanger (1b) used in the first treatment step and the H-form strongly acidic cation exchanger (3) used in the second treatment step may be the same H-form strongly acidic cation exchanger or different H-form strongly acidic cation exchangers.

[0063] In the second treatment step, the treatment liquid from the first treatment step is brought into contact with an anion exchanger (2) and an H-type strongly acidic cation exchanger (3) to treat the organic solvent to be treated with the anion exchanger (2) and the H-type strongly acidic cation exchanger (3), thereby removing the remainders of divalent or higher metals and monovalent metals that could not be completely removed by the H-type strongly acidic cation exchanger (1b) in the first treatment step. In the second treatment step, the anion exchanger removes metals that may have metal ions in the anionic form, such as Cr and As, and acids such as mineral acids and organic acids.

[0064] In the second embodiment of the method for purifying an organic solvent of the present invention, the organic solvent to be treated is first contacted with an H-type strongly acidic cation exchanger and then contacted again with an H-type strongly acidic cation exchanger, thereby performing two or more contact steps, thereby increasing the removal rate of divalent or higher metals compared to the case where the organic solvent to be treated is contacted with the same amount of H-type strongly acidic cation exchanger.

[0065] In the second treatment step, the liquid passing speed (SV) when the treatment liquid of the first treatment step is passed through the anion exchanger (2) and the H-type strongly acidic cation exchanger (3) is not particularly limited and can be appropriately selected, but is preferably 0.1 to 100 h -1 , particularly preferably 2 to 30 hours -1 It is.

[0066] In the second treatment step, the temperature at which the treatment liquid from the first treatment step is passed through the anion exchanger (2) and the H-type strongly acidic cation exchanger (3) is not particularly limited and may be appropriately selected, but is usually 0 to 50° C. Depending on the type of organic solvent to be treated, the treatment liquid from the first treatment step may be passed through the anion exchanger (2) and the H-type strongly acidic cation exchanger (3) at 0 to 80° C. in the second treatment step. When the treatment liquid from the first treatment step is passed through the anion exchanger (2) and the H-type strongly acidic cation exchanger (3) at 0 to 80° C. in the second treatment step, if a strongly basic anion exchanger (2a) is used as the anion exchanger (2), the strongly basic anion exchanger (2a) is easily decomposed, so a weakly basic anion exchanger (2b) is used as the anion exchanger (2).

[0067] Examples of the second treatment step in the method for purifying an organic solvent according to the first embodiment of the present invention and the second treatment step in the method for purifying an organic solvent according to the second embodiment of the present invention are as follows.

[0068] In the first embodiment of the second treatment step, the treatment liquid from the first treatment step is passed through a mixed bed of anion exchanger (2) and H-type strongly acidic cation exchanger (3) to perform the second treatment step. The mixed bed of anion exchanger (2) and H-type strongly acidic cation exchanger (3) is composed of a mixture of anion exchanger (2) and H-type strongly acidic cation exchanger (3). When the anion exchanger (2) is an organic porous anion exchanger, an organic porous anion exchanger cut to a desired size, for example, a cubic shape with one side of about 3 mm to about 10 mm, is used. When the H-type strongly acidic cation exchanger (3) is an organic porous strongly acidic cation exchanger, an organic porous strongly acidic cation exchanger cut to a desired size, for example, a cubic shape with one side of about 3 mm to about 10 mm, is used.

[0069] An example of the first embodiment of the method for purifying an organic solvent of the present invention or the second embodiment of the method for purifying an organic solvent of the present invention in which the second treatment step is the first embodiment is, for example, a method in which an organic solvent 20 to be treated is first passed through an H-type cation exchanger packed column 1 packed with an H-type cation exchanger (H-type chelate exchanger (1a) or H-type strongly acidic cation exchanger (1b)) as shown in Fig. 1, and then the treated liquid treated in the H-type cation exchanger packed column 1 is passed through a mixed-bed packed column 2 packed with a mixture of anion exchange resin (2) and strongly acidic cation exchange resin (3) to obtain a purified organic solvent 23. In the embodiment shown in Fig. 1, the area indicated by reference numeral 21 corresponds to the first treatment step, and the area indicated by reference numeral 22 corresponds to the second treatment step.

[0070] In the second form of the second treatment step, the treatment liquid from the first treatment step is passed through a single bed of anion exchanger (2) in the front stage and then through a single bed of H-type strongly acidic cation exchanger (3) in the rear stage, thereby carrying out the second treatment step.

[0071] An example of the second treatment step of the method for purifying an organic solvent according to the first embodiment of the present invention or the method for purifying an organic solvent according to the second embodiment of the present invention is the second embodiment, for example, as shown in Fig. 2, in which an organic solvent 20 to be treated is first passed through an H-type cation exchanger packed column 1 packed with an H-type cation exchanger (H-type chelate exchanger (1a) or H-type strongly acidic cation exchanger (1b)), the treatment liquid treated in the H-type cation exchanger packed column 1 is passed through an anion exchanger packed column 3 packed with anion exchanger (2), and the treatment liquid treated in the anion exchanger packed column 3 is passed through a strongly acidic cation exchanger packed column 4 packed with strongly acidic cation exchanger (3), to obtain a purified organic solvent 23. In the embodiment shown in Fig. 2, the area indicated by reference numeral 21 corresponds to the first treatment step, and the area indicated by reference numeral 22 corresponds to the second treatment step.

[0072] In the third embodiment of the second treatment step, the treatment liquid from the first treatment step is passed through a double bed consisting of a layer of an anion exchanger (2) in the front stage and a layer of a H-type strongly acidic cation exchanger (3) in the rear stage, thereby carrying out the second treatment step. When the anion exchanger (2) is an organic porous anion exchanger, the organic porous anion exchanger cut to a desired thickness to fit the inner diameter of the packed container or column is packed into the packed container or column. When the H-type strongly acidic cation exchanger (3) is an H-type organic porous cation exchanger, the H-type organic porous cation exchanger cut to a desired thickness to fit the inner diameter of the packed container or column is packed into the packed container or column.

[0073] An example of the third embodiment of the second treatment step of the method for purifying an organic solvent according to the first embodiment of the present invention or the method for purifying an organic solvent according to the second embodiment of the present invention is, for example, a method in which an organic solvent 20 to be treated is first passed through an H-type cation exchanger packed column 1 packed with an H-type cation exchanger (H-type chelate exchanger (1a) or H-type strongly acidic cation exchanger (1b)) as shown in Fig. 3, and then the treated liquid treated in the H-type cation exchanger packed column 1 is passed through a multi-bed packed column 7 packed with a multi-bed 7 consisting of a layer 5 of an anion exchanger (2) in the front stage and a layer 6 of an H-type strongly acidic cation exchanger (3) in the rear stage, to obtain a purified organic solvent 23. In the embodiment shown in Fig. 3, the area indicated by reference numeral 21 corresponds to the first treatment step, and the area indicated by reference numeral 22 corresponds to the second treatment step.

[0074] In the fourth form of the second treatment step, the second treatment step is carried out by passing the treated liquid from the first treatment step through a multiple bed in which a single bed of an anion exchanger (2) in the front stage and a single bed of an H-type strongly acidic cation exchanger (3) in the rear stage are repeated in two or more sets of repeating units.

[0075] An example of the fourth embodiment of the second treatment step of the method for purifying an organic solvent according to the first embodiment of the present invention or the method for purifying an organic solvent according to the second embodiment of the present invention is, for example, a method in which the organic solvent 20 to be treated is first passed through a packed tower 1 filled with an H-type cation exchanger (H-type chelate exchanger (1a) or H-type strongly acidic cation exchanger (1b)) as shown in Fig. 4, and then the treated liquid treated in the packed tower 1 filled with the H-type cation exchanger is passed through a first repeating unit 10a consisting of a packed tower 8a containing an anion exchanger (2) in the front stage and a packed tower 9a containing a strongly acidic cation exchanger (3) in the rear stage, and a second repeating unit 10b consisting of a packed tower 8b containing an anion exchanger (2) in the front stage and a packed tower 9b containing a strongly acidic cation exchanger (3) in the rear stage in this order to obtain a purified organic solvent 23. In the embodiment shown in Fig. 4, the area indicated by the reference numeral 21 corresponds to the first treatment step, and the area indicated by the reference numeral 22 corresponds to the second treatment step. In the embodiment shown in FIG. 4, two repeating units each consisting of a packed tower of an anion exchanger (2) in the front stage and a packed tower of a H-type strongly acidic cation exchanger (3) in the rear stage are repeated, but the number of repeating units each consisting of a packed tower of an anion exchanger (2) in the front stage and a packed tower of a H-type strongly acidic cation exchanger (3) in the rear stage may be three or more.

[0076] In the fifth embodiment of the second treatment step, the treated liquid from the first treatment step is passed through a double bed in which two or more sets of repeating units of a layer of the anion exchanger (2) in the front stage and a layer of the H-type strongly acidic cation exchanger (3) in the rear stage are stacked, thereby carrying out the second treatment step.

[0077] An example of the fifth embodiment in the second treatment step of the method for purifying an organic solvent according to the first embodiment of the present invention or the method for purifying an organic solvent according to the second embodiment of the present invention is, for example, a method in which, as shown in FIG. 5 , an organic solvent 20 to be treated is first passed through an H-type cation exchanger packed column 1 packed with an H-type cation exchanger (H-type chelate exchanger (1a) or H-type strongly acidic cation exchanger (1b)), and then the treated liquid treated in the H-type cation exchanger packed column 1 is passed through a multi-bed packed column 14 packed with a "first repeating unit 13a consisting of a layer 11a of an anion exchanger (2) in the front stage and a layer 12a of an H-type strongly acidic cation exchanger (3) in the rear stage" and a "second repeating unit 13b consisting of a layer 11b of an anion exchanger (2) in the front stage and a layer 12b of an H-type strongly acidic cation exchanger (3) in the rear stage" in order to obtain a purified organic solvent 23. In the embodiment shown in Fig. 5, the area indicated by the reference numeral 21 is the first treatment step, and the area indicated by the reference numeral 22 is the second treatment step. In the embodiment shown in Fig. 5, an example is shown in which two repeating units each consisting of a layer of an anion exchanger (2) in the front stage and a layer of a H-type strongly acidic cation exchanger (3) in the rear stage are repeated, but the number of repeating units each consisting of a layer of an anion exchanger (2) in the front stage and a layer of a H-type strongly acidic cation exchanger (3) in the rear stage may be three or more.

[0078] The third embodiment of the method for purifying an organic solvent of the present invention is a method for purifying an organic solvent, which comprises a treatment step (3) of contacting the organic solvent to be treated with a mixed bed of an H-type chelate exchanger (1a), an anion exchanger (2) and an H-type strongly acidic cation exchanger (3).

[0079] The treatment step (3) in the method for purifying an organic solvent according to the third embodiment of the present invention is a step of contacting the organic solvent to be treated with a mixed bed of an H-type chelate exchanger (1a), an anion exchanger (2) and an H-type strongly acidic cation exchanger (3).

[0080] The organic solvent to be treated, the H-type chelate exchanger (1a), the anion exchanger (2) and the H-type strongly acidic cation exchanger (3) in the method for purifying an organic solvent of the third embodiment of the present invention are the same as the organic solvent to be treated, the H-type chelate exchanger (1a), the anion exchanger (2) and the H-type strongly acidic cation exchanger (3) in the method for purifying an organic solvent of the first embodiment of the present invention.

[0081] The mixed bed of the H-type chelate exchanger (1a), anion exchanger (2) and H-type strongly acidic cation exchanger (3) in the method for purifying an organic solvent according to the third embodiment of the present invention is composed of a mixture of the H-type chelate exchanger (1a), anion exchanger (2) and H-type strongly acidic cation exchanger (3). When the H-type chelate exchanger (1a) is an organic porous chelate exchanger of H-type, an organic porous strongly acidic chelate exchanger of H-type cut into any size, for example, a cubic shape of about 3 mm to about 10 mm on a side, is used. When the anion exchanger (2) is an organic porous anion exchanger, an organic porous anion exchanger of H-type cut into any size, for example, a cubic shape of about 3 mm to about 10 mm on a side, is used. When the H-type strongly acidic cation exchanger (3) is an organic porous strongly acidic cation exchanger, an organic porous strongly acidic cation exchanger of H-type cut into any size, for example, a cubic shape of about 3 mm to about 10 mm on a side, is used.

[0082] In the treatment step (3), the organic solvent to be treated is treated with a mixed bed of H-type chelate exchanger (1a), anion exchanger (2) and H-type strongly acidic cation exchanger (3) by contacting the organic solvent with the mixed bed of H-type chelate exchanger (1a), anion exchanger (2) and H-type strongly acidic cation exchanger (3), thereby removing divalent or higher metals and monovalent metals in the organic solvent to be treated. In the treatment step (3), the anion exchanger (2) removes mineral acids released from the H-type chelate exchanger (1a) into the organic solvent to be treated.

[0083] In the treatment step (3), the flow rate (SV) at which the organic solvent to be treated is passed through the mixed bed of the H-type chelate exchanger (1a), the anion exchanger (2) and the H-type strongly acidic cation exchanger (3) is not particularly limited and is appropriately selected, but is preferably 0.1 to 100 h -1 , particularly preferably 2 to 30 hours -1 , more preferably 4 to 25 hours -1 It is.

[0084] In the treatment step (3), the temperature at which the organic solvent to be treated is passed through the mixed bed (3) of the H-type chelate exchanger (1a), the anion exchanger (2) and the H-type strongly acidic cation exchanger (3) is not particularly limited and may be appropriately selected, but is usually 0 to 50° C. Depending on the type of the organic solvent to be treated, the organic solvent to be treated may be passed through the mixed bed of the H-type chelate exchanger (1a), the anion exchanger (2) and the H-type strongly acidic cation exchanger (3) at 0 to 80° C. in the treatment step (3). In the treatment step (3), when the organic solvent to be treated is passed through a mixed bed of the H-type chelate exchanger (1a), the anion exchanger (2) and the H-type strongly acidic cation exchanger (3) at 0 to 80°C, a weakly basic anion exchanger (2b) is used as the anion exchanger (2) since the strongly basic anion exchanger (2a) is easily decomposed when the strongly basic anion exchanger (2a) is used as the anion exchanger (2).

[0085] As an example of the method for purifying an organic solvent according to the third embodiment of the present invention, as shown in Fig. 6, an organic solvent 20 to be treated is passed through a mixed-bed packed column 24 packed with a mixture of an H-type chelate exchanger (1a), an anion exchanger (2) and an H-type strongly acidic cation exchanger (3) to obtain a purified organic solvent 23. In the embodiment shown in Fig. 6, the area indicated by reference numeral 25 corresponds to the treatment step (3).

[0086] In the method for purifying an organic solvent according to the first embodiment of the present invention or the method for purifying an organic solvent according to the third embodiment of the present invention, the ratio of the volume of the anion exchanger (2) to the volume of the H-type chelate exchanger (1a) ((volume of anion exchanger (2) / volume of H-type chelate exchanger (1a)) × 100) is preferably 0.1 to 99.0 vol%, more preferably 0.1 to 70.0 vol%, and particularly preferably 0.1 to 50.0 vol%.

[0087] In the method for purifying an organic solvent according to the first embodiment of the present invention or the method for purifying an organic solvent according to the third embodiment of the present invention, the ratio of the volume of the strongly acidic cation exchanger (3) to the volume of the H-type chelate exchanger (1a) ((volume of strongly acidic cation exchanger (3) / volume of H-type chelate exchanger (1a)) × 100) is preferably 0.1 to 99.0 vol%, more preferably 0.1 to 70.0 vol%, particularly preferably 0.1 to 50.0 vol%.

[0088] In the H-type cation exchangers (H-type chelate exchanger (1a), strongly acidic cation exchanger (1b)), anion exchanger (2) and H-type strongly acidic cation exchanger (3), the substrate to which the ion exchange groups are introduced may be an organic porous material. The organic porous material according to the present invention is described below.

[0089] An H-type chelate exchange group, a strongly acidic cation group or an anion exchange group is introduced into the organic porous ion exchanger. That is, an organic porous ion exchanger in which an H-type chelate exchange group is introduced is an H-type organic porous chelate exchanger (1a), an organic porous ion exchanger in which an H-type strongly acidic cation exchange group is introduced is an H-type organic porous strongly acidic cation exchanger (1b) or (3), and an organic porous ion exchanger in which an anion exchange group is introduced is an organic porous anion exchanger. The functional groups introduced into the organic porous ion exchanger are the same as those introduced into the above-mentioned (H-type chelate exchanger (1a), strongly acidic cation exchanger (1b)), anion exchanger (2) or H-type strongly acidic cation exchanger (3).

[0090] Examples of the organic porous ion exchanger include an organic porous ion exchanger (hereinafter also referred to as a first type of organic porous ion exchanger) which is composed of a continuous skeleton phase and a continuous pore phase, in which the thickness of the continuous skeleton is 1 to 100 μm, the average diameter of the continuous pores is 1 to 1000 μm, the total pore volume is 0.5 to 50 mL / g, in which ion exchange groups (chelate exchange groups, H-type strongly acidic cation exchange groups or anion exchange groups) have been introduced, the ion exchange capacity per weight in a dry state is 1 to 6 mg equivalents / g, and the ion exchange groups are uniformly distributed in the organic porous ion exchanger.

[0091] An example of a first type of organic porous ion exchanger is an organic porous ion exchanger having an open-cell structure in which bubble-like macropores overlap each other and the overlapping portions form openings with an average diameter of 1 to 1000 μm, a total pore volume of 1 to 50 mL / g, ion exchange groups introduced therein, an ion exchange capacity per weight in a dry state of 1 to 6 mg equivalents / g, and the ion exchange groups uniformly distributed throughout the organic porous ion exchanger.

[0092] An example of a first type of organic porous ion exchanger is an organic porous ion exchanger having a continuous macropore structure in which bubble-like macropores overlap each other and the overlapping portions form openings with an average diameter of 30 to 300 μm, a total pore volume of 0.5 to 10 ml / g, cation exchange groups or anion exchange groups introduced therein, an ion exchange capacity per weight in a dry state of 1 to 6 mg equivalents / g, the ion exchange groups uniformly distributed in the organic porous ion exchanger, and in an SEM image of a cut surface of the continuous macropore structure (dried body), the area of ​​the framework appearing in the cross section is 25 to 50% of the image area.

[0093] An example of a first type of organic porous ion exchanger is an organic porous ion exchanger having a bicontinuous structure composed of a three-dimensionally continuous skeleton having an average thickness of 1 to 60 μm and made of an aromatic vinyl polymer containing 0.1 to 5.0 mol % of crosslinked structural units among all structural units having ion exchange groups (chelate exchange groups, H-type strongly acidic cation exchange groups or anion exchange groups) introduced therein, and three-dimensionally continuous pores having an average diameter of 10 to 200 μm between the skeletons, a total pore volume of 0.5 to 10 mL / g, cation exchange groups introduced therein, an ion exchange capacity per weight in a dry state of 1 to 6 mg equivalents / g, and the ion exchange groups uniformly distributed in the organic porous ion exchanger.

[0094] The content of each metal in the purified organic solvent obtained by carrying out the method for purifying an organic solvent in the first embodiment of the present invention, the method for purifying an organic solvent in the second embodiment of the present invention, and the method for purifying an organic solvent in the third embodiment of the present invention is appropriately selected depending on the use of the organic solvent after purification, and preferably all of them are 10 mass ppt or less. That is, the content of each divalent or more metal in the purified organic solvent obtained by carrying out the method for purifying an organic solvent in the first embodiment of the present invention, the method for purifying an organic solvent in the second embodiment of the present invention, and the method for purifying an organic solvent in the third embodiment of the present invention is appropriately selected depending on the use of the organic solvent after purification, and preferably all of them are 10 mass ppt or less, and the content of a monovalent metal is appropriately selected depending on the use of the organic solvent after purification, and preferably all of them are 10 mass ppt or less. Examples of the use of the purified organic solvent obtained by carrying out the method for purifying an organic solvent in the first embodiment of the present invention, the method for purifying an organic solvent in the second embodiment of the present invention, and the method for purifying an organic solvent in the third embodiment of the present invention include a dilution solvent, a dissolution solvent, a cleaning solvent, a drying solvent, etc. in the semiconductor manufacturing process. Furthermore, according to the method for purifying an organic solvent in the first embodiment of the present invention, the method for purifying an organic solvent in the second embodiment of the present invention, and the method for purifying an organic solvent in the third embodiment of the present invention, purification to an impurity level of 1 ppt by mass or less is possible, and therefore the purified organic solvent obtained by carrying out the method for purifying an organic solvent in the first embodiment of the present invention, the method for purifying an organic solvent in the second embodiment of the present invention, and the method for purifying an organic solvent in the third embodiment of the present invention is suitably used as a dilution solvent for a standard solution used for preparing a calibration curve for trace metal analysis (a blank solution for a calibration curve), a dilution solvent for samples, and a cleaning solvent for instruments and analytical devices.

[0095] The first embodiment of the organic solvent purification apparatus of the present invention is an organic solvent purification apparatus characterized by having a single bed of H-type cation exchanger (1) through which the organic solvent to be treated is passed, and a mixed bed of anion exchanger (2) and H-type strongly acidic cation exchanger (3) through which the treatment liquid from the single bed of the H-type cation exchanger (1) is passed.

[0096] An example of the flow of the organic solvent purification apparatus according to the first embodiment of the present invention is shown in FIG.

[0097] The second embodiment of the organic solvent purification apparatus of the present invention is an organic solvent purification apparatus characterized by having a single bed of H-type cation exchanger (1) through which the organic solvent to be treated is passed, a single bed of anion exchanger (2) through which the treatment liquid from the single bed of H-type cation exchanger (1) is passed, and a single bed of H-type strongly acidic cation exchanger (3) through which the treatment liquid from the single bed of anion exchanger (2) is passed.

[0098] An example of the flow of the organic solvent purification apparatus according to the second embodiment of the present invention is shown in FIG.

[0099] The third embodiment of the organic solvent purification apparatus of the present invention is an organic solvent purification apparatus characterized by having a single bed of H-type cation exchanger (1) through which the organic solvent to be treated is passed, and a double bed through which the treatment liquid of the single bed of the H-type cation exchanger (1) is passed, the double bed being composed of a layer of anion exchanger (2) in the front stage and a layer of H-type strongly acidic cation exchanger (3) in the rear stage.

[0100] An example of the flow of the organic solvent purification apparatus according to the third embodiment of the present invention is shown in FIG.

[0101] The organic solvent purification apparatus according to the first to third embodiments of the present invention may be an organic solvent purification apparatus in which the H-type cation exchanger (1) is an H-type chelate exchanger. Also, the organic solvent purification apparatus according to the first to third embodiments of the present invention may be an organic solvent purification apparatus in which the H-type cation exchanger (1) is an H-type strongly acidic cation exchanger.

[0102] The fourth embodiment of the organic solvent purification apparatus of the present invention is an organic solvent purification apparatus characterized by having a mixed bed of an H-type chelate exchanger, an anion exchanger (2) and an H-type strongly acidic cation exchanger (3) through which the organic solvent to be treated is passed.

[0103] An example of the flow of the organic solvent purification apparatus according to the fourth embodiment of the present invention is shown in FIG.

[0104] The fourth embodiment of the organic solvent purification apparatus of the present invention includes an organic solvent purification apparatus in which the H-type cation exchanger (1) is an H-type chelate exchanger.

[0105] The H-type cation exchanger (1), the anion exchanger (2) and the H-type strongly acidic cation exchanger (3) in the organic solvent purification apparatus of the first to fourth embodiments of the present invention are the same as the H-type cation exchanger (1), the anion exchanger (2) and the H-type strongly acidic cation exchanger (3) in the organic solvent purification method of the first to third embodiments of the present invention.

[0106] In the first to fourth embodiments of the organic solvent purification apparatus of the present invention, when the H-type cation exchanger (1) is an H-type chelate exchanger, the ratio of the volume of the anion exchanger (2) to the volume of the H-type chelate exchanger (1a) ((volume of anion exchanger (2) / volume of H-type chelate exchanger (1a)) × 100) is preferably 0.1 to 99.0 vol%, more preferably 0.1 to 70.0 vol%, and particularly preferably 0.1 to 50.0 vol%.

[0107] In the first to fourth embodiments of the organic solvent purification apparatus of the present invention, when the H-type cation exchanger (1) is an H-type chelate exchanger, the ratio of the volume of the strongly acidic cation exchanger (3) to the volume of the H-type chelate exchanger (1a) ((volume of strongly acidic cation exchanger (3) / volume of H-type chelate exchanger (1a)) × 100) is preferably 0.1 to 99.0 vol%, more preferably 0.1 to 70.0 vol%, and particularly preferably 0.1 to 50.0 vol%.

[0108] Although the embodiments of the invention have been described above, the present invention is not limited to these, and various modifications and additions are possible within the scope of the invention. For example, in Figs. 1 to 5, the first and second treatment steps are carried out using two or more connected packed towers, but the first and second treatment steps may be carried out using one packed tower by forming a multiple bed in which a bed for carrying out the first treatment step is packed in the front stage and a bed for carrying out the second treatment step is packed in the rear stage. For example, there is an example of a multiple bed configuration in which a bed of H-type chelate exchanger (1a) is packed in the front stage of one packed tower and a mixed bed of anion exchanger (2) and H-type strongly acidic cation exchanger (3) is packed in the rear stage. In this case, the first treatment step is carried out in the bed of H-type chelate exchanger (1a) in the front stage, and the second treatment step is carried out in the mixed bed of anion exchanger (2) and H-type strongly acidic cation exchanger (3) in the rear stage. EXAMPLES

[0109] The present invention will be described in detail below with reference to examples, although the present invention is not limited to the following examples.

[0110] (Reference example 1) A column with an inner diameter of 16 mm and a height of 300 mm was filled with 50 mL of H-type chelate exchange resin (DS-21). Next, isopropyl alcohol (IPA) with a water content of 20 mass ppm or less was passed from the top to the bottom of the column, and the liquid was continued to pass through until the water content at the outlet fell to 30 mass ppm or less, replacing the water inside the resin with IPA. Next, IPA simulant 1 was added to the column for SV5h. -1 The liquid was passed through the column at 20 BV (20 times the resin volume), and the treated liquid was sampled. The metal content of the resulting treatment liquid was then measured using an Agilent 8900 ICP-QQQ (Agilent Corp.). The results are shown in Table 2. The water content of the IPA simulation liquid and the treatment liquid was also measured, and it was confirmed that both were 30 mass ppm or less. Similarly, the IPA simulant liquid 2 was passed through the filter. The results are shown in Table 2.

[0111] · H-shaped chelating exchange resin: H-shaped amino acid chelating resin (manufactured by Organo Corporation, Orlite DS-21 (cation exchange capacity 1.8 eq / L - resin, harmonic mean diameter 500 μm))

[0112] <IPA simulated solution> To IPA XE (manufactured by Tokuyama Corporation), a paraffin oil-based organometallic standard solution Conostan (manufactured by CONOSTAN) was added with a standard solution for ICP-AES / ICP-MS to prepare 1000 mass ppt of IPA simulated solution 1. Similarly, 100 mass ppt of IPA simulated solution 2 was prepared. The metal contents in the IPA simulated solutions are shown in Table 1.

[0113]

Table 1

[0114] <Moisture measurement> The moisture content was measured using Aquacounter AQ-2200 (manufactured by Hiranuma Sangyo Co., Ltd.).

[0115]

Table 2

[0116] (Example 1) 50 mL of a mixture obtained by mixing H-shaped chelating exchange resin (DS-21), OH-shaped strong basic anion exchange resin (DS-2), and H-shaped strong acidic cation exchange resin (DS-1) in a volume ratio of 3:1:1 was filled into a column with an inner diameter of 16 mm and a height of 300 mm (H-shaped C / OH-shaped A / H-type K mixed bed 1). Next, IPA simulated solution 2 was passed through H-shaped C / OH-shaped A / H-type K mixed bed 1 at SV 5 h -1 and when 20 BV (20 times the resin volume) of liquid was passed through, the treated liquid was sampled. Next, the metal content of the obtained treated liquid was measured. The results are shown in Table 3.

[0117] ·OH type strong basic anion exchange resin (DS-2): Organo Corporation (anion exchange capacity 1.0eq / L-resin) H-type strong acid cation exchange resin (DS-1): Organo Corporation (cation exchange capacity 2.0eq / L-resin)

[0118] Example 2 30 mL of H-type chelate exchange resin (DS-21) was packed in a column with an inner diameter of 16 mm and a height of 300 mm (H-type C single bed 1). In addition, a column with an inner diameter of 16 mm and a height of 300 mm was packed with OH-type strongly basic anion exchange resin (DS-2) in the front stage and H-type strongly acidic cation exchange resin (DS-1) in the rear stage with a layer thickness ratio of 1:1, for a total of 20 mL (OH-type A / H-type K double bed 1). Next, the H-type C single bed 1 in the front stage and the OH-type A / H-type K double bed 1 in the rear stage were connected. Next, IPA simulant solution 2 was poured into H-type C single bed 1 in the front stage and OH-type A / H-type K double bed 1 in the rear stage for 5 h. -1 The liquid was passed through the column at 20 BV (20 times the resin volume), and the treated liquid was sampled. The metal content of the resulting treatment solution was then measured, and the results are shown in Table 3.

[0119] Comparative Example 1 50 mL of H-type strongly acidic cation exchange resin (DS-1) was packed into a column having an inner diameter of 16 mm and a height of 300 mm (H-type K single bed 1). Next, IPA simulant solution 1 was poured into H-type K single bed 1 for 5 h. -1 The liquid was passed through the column at 20 BV (20 times the resin volume), and the treated liquid was sampled. The metal content of the resulting treatment solution was then measured, and the results are shown in Table 3.

[0120] Comparative Example 2 A 50 mL mixture of OH-type strongly basic anion exchange resin (DS-2) and H-type strongly acidic cation exchange resin (DS-1) mixed in a volume ratio of 1:1 was packed into a column with an inner diameter of 16 mm and a height of 300 mm (OH-type A / H-type K mixed bed 1). Next, IPA simulant solution 1 was added to OH type A / H type K mixed bed 1 for SV5h. -1The liquid was passed through the column at 20 BV (20 times the resin volume), and the treated liquid was sampled. The metal content of the resulting treatment solution was then measured, and the results are shown in Table 3.

[0121] Comparative Example 3 30 mL of H-type chelate exchange resin (DS-21) was packed into a column with an inner diameter of 16 mm and a height of 300 mm (H-type C single bed 1). Also, 20 mL of OH-type strong basic anion exchange resin (DS-2) was packed into a column with an inner diameter of 16 mm and a height of 300 mm (OH-type A single bed 1). Next, the front-stage H-type C single bed 1 and the rear-stage OH-type A single bed 1 were connected. Next, IPA simulant solution 2 was poured into the H-type C single bed 1 in the front stage and the OH-type A single bed 1 in the rear stage for 5 h. -1 The liquid was passed through the column at 20 BV (20 times the resin volume), and the treated liquid was sampled. The metal content of the resulting treatment solution was then measured, and the results are shown in Table 3.

[0122] Comparative Example 4 50 mL of OH-form strongly basic anion exchange resin (DS-2) was packed into a column having an inner diameter of 16 mm and a height of 300 mm (OH-form A single bed 1). Next, IPA simulant solution 1 was poured into OH type A single bed 1 for SV5h. -1 The liquid was passed through the column at 20 BV (20 times the resin volume), and the treated liquid was sampled. The metal content of the resulting treatment solution was then measured, and the results are shown in Table 3.

[0123] [Table 3] (Examples 3 to 6) SV5h -1 The same procedure as in Example 1 was carried out, except that instead of passing the solution at SV shown in Table 4, the solution was passed at SV shown in Table 4. The results are shown in Table 4.

[0124] [Table 4]

[0125] Comparative Example 5 36 mL of H-type strong acid cation exchange resin (DS-1) was packed in a column with an inner diameter of 16 mm and a height of 300 mm (H-type K single bed 1). Then, IPA simulant solution 3 (shown in Table 5) was added to the column for 5 h. -1 The liquid was passed through the column at 20 BV (20 times the resin volume), and the treated liquid was sampled. The metal content of the resulting treatment solution was then measured, and the results are shown in Table 6.

[0126] Example 7 A column with an inner diameter of 16 mm and a height of 300 mm was packed with 18 mL of H-type strongly acidic cation exchange resin (DS-1) in the front stage and 18 mL of a mixed bed of 9 mL of H-type strongly acidic cation exchange resin (DS-1) and 9 mL of a mixed resin of OH-type strongly basic anion exchange resin (DS-2) in the rear stage, with a layer thickness ratio of 1:1, for a total of 36 mL (H-type K / H-type, OH-type mixed bed 1). Next, IPA simulation liquid 4 (shown in Table 5) was added to the H-type K / H-type and OH-type mixed bed 1 for SV5h. -1 The liquid was passed through the column at 20 BV (20 times the resin volume), and the treated liquid was sampled. The metal content of the resulting treatment solution was then measured, and the results are shown in Table 6. H-type strong acid cation exchange resin (DS-1): Organo Corporation (cation exchange capacity ≧ 2.1eq / L-resin) ·OH type strong basic anion exchange resin (DS-2): Organo Corporation (anion exchange capacity ≧ 1.0eq / L-resin)

[0127] [Table 5]

[0128] [Table 6] [Explanation of symbols]

[0129] 1. H-type cation exchanger packed column 2, 24 mixed bed packed column 3, 8a, 8b Anion exchange packed columns 4, 9a, 9b Strongly acidic cation exchanger packed column 5, 11a, 11b Anion exchanger layers 6, 12a, 12b Layers of H-type strongly acidic cation exchangers 7, 14 Multi-bed packed column 10a, 10b, 13a, 13b repeat units 20 Organic solvent to be treated 21 First treatment process 22 Second treatment process 23 Processing liquid 25 Processing Steps (3)

Claims

1. A first treatment step in which an organic solvent to be treated, the organic solvent having a content of each metal impurity in the organic solvent of 100 mass ppb to 20 mass ppt, is contacted with an H-type chelate exchanger; a second treatment step in which the treatment liquid from the first treatment step is contacted with an OH-type strongly basic anion exchanger (2) and an H-type strongly acidic cation exchanger (3); the resulting purified organic solvent is used in a semiconductor manufacturing process or for trace metal analysis, and each metal content in the resulting purified organic solvent is 10 ppt by mass or less; A method for purifying an organic solvent, characterized in that the functional group of the H-type chelate exchanger is an iminodiacetic acid group, an aminomethylphosphate group or an iminopropionic acid group.

2. A first treatment step of contacting an organic solvent to be treated, the organic solvent having a content of each metal impurity in the organic solvent of 100 mass ppb to 20 mass ppt, with an H-type strongly acidic cation exchanger; a second treatment step in which the treatment liquid from the first treatment step is contacted with an OH-type strongly basic anion exchanger (2) and an H-type strongly acidic cation exchanger (3); the resulting purified organic solvent is used in a semiconductor manufacturing process or for trace metal analysis, and each metal content in the resulting purified organic solvent is 10 ppt by mass or less.

3. 3. The method for purifying an organic solvent according to claim 1, wherein the second treatment step is carried out by passing the treatment liquid from the first treatment step through a mixed bed of the strongly basic OH-type anion exchanger (2) and the strongly acidic H-type cation exchanger (3).

4. 3. The method for purifying an organic solvent according to claim 1, wherein the second treatment step is carried out by first contacting the treatment liquid from the first treatment step with the strongly basic OH-type anion exchanger (2) and then with the strongly acidic H-type cation exchanger (3).

5. 2. The method for purifying an organic solvent according to claim 1, wherein the ratio of the volume of said OH-type strong basic anion exchanger to the volume of said H-type chelate exchanger is 0.1 to 99.0% by volume.

6. 6. The method for purifying an organic solvent according to claim 1, wherein the ratio of the volume of the H-type strongly acidic cation exchanger to the volume of the H-type chelate exchanger is 0.1 to 99.0% by volume.

7. 7. The method for purifying an organic solvent according to claim 1, wherein the organic solvent is a polar organic solvent.

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