Method and apparatus for producing a dry ion exchange resin, and method and apparatus for purifying a liquid to be treated

Abstract

Provided are a dry ion exchange resin manufacturing method and manufacturing device with which it is possible to obtain a dry ion exchange resin having a reduced moisture content and metal content, and a treated liquid purifying method and purifying device employing the dry ion exchange resin. This dry ion exchange resin manufacturing method includes: a purifying step for obtaining a purified cation exchange resin by bringing a cation exchange resin to be purified into contact with a mineral acid solution having a metal impurity content of 1 mg / L or less and a concentration of 5% by weight or more, to purify the cation exchange resin, wherein a total metal impurity elution amount eluted when hydrochloric acid having a concentration of 3% by weight is passed through the purified cation exchange resin with a volume ratio of 25 times is at most equal to 5 μg / mL-R; and a drying step of drying the purified cation exchange resin under reduced pressure at 80°C or lower until the moisture content is at most equal to 5% by weight.

Description

Technical Field

[0001] The present invention relates to a method and apparatus for producing a dry ion exchange resin, and a method and apparatus for purifying a liquid to be treated using the dry ion exchange resin.

Background Art

[0002] In recent years, as a semiconductor manufacturing process, an electrolyte of a lithium ion battery, etc., a non-aqueous solvent from which impurities have been highly removed and purified has been used.

[0003] As a method for purifying a non-aqueous solvent, a distillation method for removing impurities by distillation is known, but there are technical problems such as a large burden on equipment costs, a large amount of energy required for distillation treatment, and difficulty in performing high-level purification.

[0004] Therefore, in recent years, a method for purifying a non-aqueous solvent by an ion exchange method using an ion exchange resin, an ion exchange filter, etc. has been proposed. According to the ion exchange method, it is said that the burden on equipment costs is small, energy is saved, and impurities can be highly purified and removed.

[0005] About 50% of the weight of the ion exchange resin is water, and the water eluted from the ion exchange resin during the purification of the non-aqueous solvent becomes an impurity of the non-aqueous solvent. Therefore, in the purification of a non-aqueous solvent using an ion exchange resin, it is necessary to reduce the water content of the ion exchange resin before purification.

[0006] As a conventional technique for reducing the water eluted from the ion exchange resin before solvent purification, there is a method of drying the ion exchange resin to remove water and bringing the non-aqueous liquid into contact with the dried ion exchange resin to reduce the water (see Patent Documents 1 and 2). A technique of vacuum-drying a strong cation exchange resin at a predetermined range of temperatures has also been reported (see Patent Document 3).

[0007] Regarding dry resins, methods for purifying non-aqueous liquids that reduce the water content to a predetermined value or less and mix with ion-exchange resins in different ionic forms for use have been reported, as well as a purification method in which the ion-exchange resin is dried while filled in a cartridge and then brought into contact with a non-aqueous liquid (see Patent Document 4). A method for purifying a non-aqueous solvent has been reported in which a non-aqueous solvent for dehydration treatment is passed through a packed bed of granular resin having an ion-exchange group before dehydration treatment to remove the water content of the granular resin, and then the non-aqueous solvent to be purified is passed through the packed bed of dehydrated granular resin (see Patent Document 5). As a method for bringing a non-aqueous liquid into contact with an ion-exchange resin, a method in which the non-aqueous liquid is circulated through zeolite and an ion-exchange resin to reduce the water content has been reported (see Patent Document 6).

[0008] For the purification of non-aqueous solvents, particularly hydrolyzable solvents, it is also known to use an H-form cation-exchange resin having a chelating group or a weakly acidic cation-exchange group with a slightly lower acidity instead of the strong cation-exchange resin commonly used for general metal removal (see Patent Document 7). Furthermore, purification methods for chelating resins with a low metal content and purification methods for non-aqueous liquids using such chelating resins have also been reported (see Patent Documents 8 and 9).

[0009] However, there are no reports on cation-exchange resins such as chelating resins with an extremely low water content and a low metal content. Although the effect of chelating resins on the purification of non-aqueous liquids is known, in the semiconductor market and other fields where the demand for high purity is increasing, cation-exchange resins such as chelating resins with a lower water content and higher cleanliness are required.

Prior Art Documents

Patent Documents

[0010]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

[0011] An object of the present invention is to provide a method and an apparatus for producing a dry ion exchange resin capable of obtaining a dry ion exchange resin with reduced water content and metal content, and a method and an apparatus for purifying a liquid to be treated using the dry ion exchange resin. [Means for Solving the Problems]

[0012] The present invention is a purification step of obtaining a purified cation exchange resin by contacting a cation exchange resin to be purified with a mineral acid solution having a content of metal impurities of 1 mg / L or less and a concentration of 5% by weight or more for purification, wherein the total amount of eluted metal impurities eluted when 3% by weight hydrochloric acid is passed through the purified cation exchange resin in a volume ratio of 25 times is 5 μg / mL-R or less, and a drying step of drying the purified cation exchange resin under reduced pressure at 80° C. or lower until the water content is 5% by weight or less. to obtain a dry ion exchange resin and includes wherein the cation exchange resin is a chelating resin or a weak cation exchange resin, and the dry ion exchange resin is for purification to make the metal concentration contained after purification of the hydrolyzable solvent 1 ppb or less for each metal a method for producing a dry ion exchange resin.

[0013] In the method for producing the dry ion exchange resin, the contents of sodium (Na), calcium (Ca), magnesium (Mg), and iron (Fe) in the mineral acid solution used in the purification step may each be 200 μg / L or less.

[0014] In the method for producing the dried ion exchange resin, the drying step in which, by drying under reduced pressure The obtained dried cation exchange resin may be mixed with an anion exchange resin having a water content of 10% by weight or less. to obtain the dry ion exchange resin It may be.

[0015] In the method for producing the dried ion exchange resin, the cation exchange resin may have an aminomethylphosphonic acid group or an iminodiacetic acid group as a chelating group. In the method for producing the dry ion exchange resin, the cation exchange resin is a weak cation exchange resin, and in the drying step, it is preferably dried under reduced pressure so that the exchange capacity after drying exceeds 92.5% of the exchange capacity before drying.

[0016] The dried ion exchange resin obtained by the method for producing the dried ion exchange resin may be stored in a container whose interior in contact with the dried ion exchange resin is covered with a non-metallic material and whose water vapor permeability for 24 hours is 8 g / m 2 or less.

[0017] The present invention is a purification means for obtaining a purified cation exchange resin by contacting a cation exchange resin to be purified with a mineral acid solution having a content of metal impurities of 1 mg / L or less and a concentration of 5% by weight or more, wherein the total amount of eluted metal impurities eluted when 3% by weight hydrochloric acid is passed through the purified cation exchange resin in a volume ratio of 25 times is 5 μg / mL-R or less, and a drying means for drying the purified cation exchange resin under reduced pressure at 80°C or lower to a water content of 5% by weight or less. to obtain a dry ion exchange resin It is provided with wherein the cation exchange resin is a chelating resin or a weak cation exchange resin, and the dry ion exchange resin is for purification to make the metal concentration contained after purification of the hydrolyzable solvent 1 ppb or less for each metal It is a manufacturing apparatus for a dried ion exchange resin.

[0018] In the manufacturing apparatus for the dried ion exchange resin, it is preferable that the drying means includes a heater installed so as to cover at least a part of the outside of a column in which the purified cation exchange resin is stored, and a pump for reducing the pressure inside the column.

[0019] In the manufacturing apparatus for the dried ion exchange resin, it is preferable that the drying means includes a drying device for accommodating and heating the purified cation exchange resin, and a pump for reducing the pressure inside the drying device.

[0020] In the apparatus for producing the dried ion exchange resin, the contents of sodium (Na), calcium (Ca), magnesium (Mg), and iron (Fe) in the mineral acid solution used in the purification means may each be 200 μg / L or less.

[0021] The apparatus for producing the dried ion exchange resin may further include a mixing means for mixing the dried cation exchange resin obtained by the drying means with an anion exchange resin having a water content of 10% by weight or less.

[0022] In the apparatus for producing the dried ion exchange resin, the cation exchange resin may have an aminomethylphosphonic acid group or an iminodiacetic acid group as a chelating group. In the apparatus for producing the dry ion exchange resin, the cation exchange resin is a weak cation exchange resin, and in the drying means, it is preferably dried under reduced pressure so that the exchange capacity after drying exceeds 92.5% of the exchange capacity before drying.

[0023] In the apparatus for producing the dried ion exchange resin, the dried ion exchange resin obtained by the apparatus for producing the dried ion exchange resin is covered with a non-metallic material inside and has a water vapor permeability of 8 g / m for 24 hours. 2 It may be stored in the following container.

[0024] The present invention uses the dried ion exchange resin obtained by the method for producing the dried ion exchange resin to As the hydrolyzable solvent Purify a treatment liquid having an ionic impurity and a water concentration of 1% by weight or less, which is a method for purifying a treatment liquid.

[0026] The present invention uses the dried ion exchange resin obtained by the apparatus for producing the dried ion exchange resin to As the hydrolyzable solvent A treatment liquid purification apparatus including a treatment liquid purification means for purifying a treatment liquid having an ionic impurity and a water concentration of 1% by weight or less.

Advantages of the Invention

[0028] According to the present invention, it is possible to provide a method and an apparatus for producing a dried ion exchange resin capable of obtaining a dried ion exchange resin with a reduced water content and metal content, and a method and an apparatus for purifying a treatment liquid using the dried ion exchange resin.

Brief Description of Drawings

[0029]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0030] Embodiments of the present invention will be described below. This embodiment is an example of carrying out the present invention, and the present invention is not limited to this embodiment.

[0031] <Method for Producing Dry Ion Exchange Resin> The method for producing a dry ion exchange resin according to this embodiment includes a purification step of obtaining a purified cation exchange resin by bringing a cation exchange resin to be purified into contact with a mineral acid solution having a content of metal impurities of 1 mg / L or less and a concentration of 5% by weight or more for purification, and a drying step of subjecting the purified cation exchange resin to reduced pressure drying at 80°C or lower until the water content is 5% by weight or less. In the method for producing a dry ion exchange resin according to this embodiment, the total amount of eluted metal impurities eluted when hydrochloric acid having a concentration of 3% by weight is passed through the purified cation exchange resin obtained in the purification step in an amount 25 times the volume ratio is 5 μg / mL-R or less.

[0032] The inventors considered purifying a cation exchange resin to be purified by bringing it into contact with a mineral acid solution. However, if the mineral acid solution to be brought into contact contains metal impurities, not only can the metal impurities in the cation exchange resin not be reduced, but on the contrary, the cation exchange resin may adsorb and increase the metal impurities in the aqueous mineral acid solution. As a result, when the cation exchange resin after contact with the mineral acid solution is used for purifying a liquid to be treated such as a non-aqueous solvent, a large amount of metal substances and the like are eluted into the liquid to be treated instead. In particular, among metals, sodium (Na), calcium (Ca), magnesium (Mg), and iron (Fe) have a higher content in the cation exchange resin compared to other metals, and it is difficult to reduce their content even by contact with a mineral acid solution.

[0033] Therefore, by bringing a mineral acid solution having a metal impurity content of 1 mg / L or less and a concentration of 5 wt% or more into contact with the cation exchange resin to be purified, the total amount of metal impurities eluted when hydrochloric acid with a concentration of 3 wt% is passed through the obtained purified cation exchange resin in a volume ratio of 25 times is set to 5 μg / mL-R or less. Next, this purified cation exchange resin is dried under reduced pressure at 80°C or lower until the water content is 5 wt% or less. By this method, a dried ion exchange resin with a reduced water content and metal content can be obtained. In particular, it is possible to sufficiently reduce water elution and metal elution from a cation exchange resin for metal removal used for purifying a highly hydrolyzable solvent with a metal concentration of 1 ppb or less for each metal after purification.

[0034] By bringing the cation exchange resin to be purified into contact with a mineral acid solution having a low content of metal impurities and a high acid concentration, conversion of the cation exchange resin into a metal ion form during contact with the mineral acid is suppressed, and the amount of metal impurities in the cation exchange resin can be reliably and effectively reduced, thereby obtaining a purified cation exchange resin with a small amount of eluted metal impurities. Specifically, the total amount of all metal impurities eluted (particularly the amount of eluted metals such as Na, Ca, Mg, Fe, etc.) when hydrochloric acid with a concentration of 3% by weight is passed through at a volume ratio of 25 times can be made 5 μg / mL-R or less. Then, this purified cation exchange resin is dried under reduced pressure at 80°C or lower until the water content is 5% by weight or less. By purifying a liquid to be treated such as a non-aqueous solvent using the dried ion exchange resin thus obtained, elution of moisture can be suppressed, and a high-purity treated liquid such as a non-aqueous solvent with a small amount of contained metal impurities can be obtained.

[0035] Drying under reduced pressure is common and can be carried out at low cost. In drying under reduced pressure, even when heated below the heat-resistant temperature of the cation exchange resin, water can be sufficiently removed. In the case of chelating resins and weak cation exchange resins, the interaction between the functional groups and the bound water is weaker than that of strong cation exchange resins and strong anion exchange resins, so they are easily dried by drying under reduced pressure. On the other hand, strong anion exchange resins have particularly low heat resistance, and the functional groups are degraded by the heat during drying. In the case of strong cation exchange resins, when heated at a high temperature, the functional groups may be desorbed by the heat during drying. In order to suppress the elution of moisture into a liquid to be treated such as a non-aqueous solvent, it is sufficient to reduce the water content to 5% by weight or less, and it may be reduced to 2% by weight or less, or it may be reduced to 1% by weight or less. Incidentally, the dried chelating resin in Patent Document 3 contains 10 to 97% of the saturated water content, and if the chelating resin has a saturated water content of about 60%, the water content is about 6%.

[0036] The cation exchange resins to be refined include strong cation exchange resins, weak cation exchange resins, chelating resins, etc., and may be at least one of chelating resins and weak cation exchange resins. Chelating resins and weak cation exchange resins have a lower affinity for bound water than strong cation exchange resins and strong anion exchange resins, so desorption of functional groups due to drying hardly occurs, and elution from the resin is less.

[0037] A chelating resin is a resin having a functional group capable of forming a chelate (complex) with a metal ion. This functional group may be any functional group capable of forming a chelate (complex) with a metal ion, and there is no particular limitation. For example, in a chelating resin having a cation exchange group, cation exchange groups such as aminomethylphosphonic acid groups, iminodiacetic acid groups, and thiol groups can be mentioned, and in a chelating resin having an anion exchange group, anion exchange groups such as polyamine groups can be mentioned. In particular, the polyamine group is effective not only for removing metal ions but also for removing impurities having aldehyde and ketone groups in water and non-aqueous liquids, and can simplify the pretreatment process when used in a non-aqueous liquid by drying. As the chelating resin, from the viewpoint of selectivity for a plurality of metal species, etc., it may have an aminomethylphosphonic acid group or an iminodiacetic acid group as a chelating group.

[0038] As the chelating resin, for example, AmberSep IRC747UPS (chelating group: aminomethylphosphonic acid group), AmberSep IRC748 (chelating group: iminodiacetic acid group) (both manufactured by DuPont) etc. can be used. The chelating resin may be used after pretreatment such as regeneration treatment as necessary. In addition, as H-form chelating resins, Orlite (registered trademark) DS-21 (trade name, manufactured by Organo Corporation) (chelating group: aminomethylphosphonic acid group), Orlite (registered trademark) DS-22 (trade name, manufactured by Organo Corporation) (chelating group: iminodiacetic acid group) may be used.

[0039] The ionic form of AmberSep IRC747UPS and AmberSep IRC748 is based on the Na form. However, by contacting with a mineral acid solution by the above method, the ionic form is converted from the Na form to the H form.

[0040] Examples of the functional group of the weak cation exchange resin include a carboxyl group and the like.

[0041] Examples of the weak cation exchange resin that can be used include Amberlite IRC76 (functional group: carboxylic acid group) (manufactured by DuPont), Amberlite FPC3500 (functional group: carboxylic acid group) (manufactured by DuPont), and the like. The weak cation exchange resin may be used after pretreatment such as regeneration treatment as necessary.

[0042] Examples of the functional group of the strong cation exchange resin include a sulfonic acid group and the like.

[0043] Examples of the strong cation exchange resin that can be used include Amberlite IR124 (functional group: sulfonic acid group) (manufactured by DuPont), Amberlite 200CT (functional group: sulfonic acid group) (manufactured by DuPont), Orlite (registered trademark) DS-1 (trade name, manufactured by Organo Corporation) (functional group: sulfonic acid group), Orlite (registered trademark) DS-4 (trade name, manufactured by Organo Corporation) (functional group: sulfonic acid group), and the like. The strong cation exchange resin may be used after pretreatment such as regeneration treatment as necessary.

[0044] The mineral acid solution used for the purification of the cation exchange resin is a solution of an inorganic acid. Examples of the mineral acid include hydrochloric acid, sulfuric acid, nitric acid, and the like. Examples of the solvent constituting the solution are water such as pure water (specific resistance: about 10 MΩ·cm) and ultrapure water (specific resistance: about 18 MΩ·cm).

[0045] The amount of metal impurities contained in the mineral acid solution used in the purification process is 1 mg / L or less, and the less the better. It may be 0.5 mg / L or less, or may be 0.2 mg / L or less. When the amount of metal impurities contained in the mineral acid solution exceeds 1 mg / L, a sufficient effect of reducing the amount of metal impurities in the cation exchange resin cannot be obtained.

[0046] The concentration of the mineral acid in the mineral acid solution is 5 wt% or more, and may be 10 wt% or more. When the concentration of the mineral acid in the mineral acid solution is less than 5 wt%, a sufficient effect of reducing the amount of metal impurities in the cation exchange resin cannot be obtained. The upper limit of the concentration of the mineral acid in the mineral acid solution is, for example, 37 wt%.

[0047] Here, the concept of metal impurities includes metal impurity ions in addition to metals. Typical examples include sodium (Na), calcium (Ca), magnesium (Mg), and iron (Fe).

[0048] The content of each of sodium (Na), calcium (Ca), magnesium (Mg), and iron (Fe) in the mineral acid solution used in the purification process is the less the better, and may be 200 μg / L or less respectively, or may be 100 μg / L or less respectively. By bringing a mineral acid solution with a low content of these metal impurities into contact with a cation exchange resin, the content of metal impurities such as sodium (Na), calcium (Ca), magnesium (Mg), and iron (Fe) in the cation exchange resin can be reliably and effectively reduced.

[0049] The temperature of the mineral acid solution brought into contact with the cation exchange resin in the purification process is, for example, in the range of 0 to 40 °C.

[0050] In the method for producing a dry ion exchange resin according to this embodiment, in the above purification step, the total metal impurity elution amount eluted when hydrochloric acid with a concentration of 3% by weight is passed through the purified cation exchange resin in a volume ratio of 25 times can be set to 5 μg / mL-R or less. The smaller the total metal impurity elution amount, the better, and it may be 1 μg / mL-R or less. By setting the total metal impurity elution amount to 5 μg / mL-R or less, when the dry ion exchange resin obtained by drying this purified cation exchange resin in the above drying step is used for purifying the liquid to be treated, the elution amount of these metal impurities from the cation exchange resin into the treatment liquid can be reduced.

[0051] The eluted metal impurities may contain at least one metal among sodium (Na), calcium (Ca), magnesium (Mg), or iron (Fe).

[0052] After the purification step, a washing step of washing the purified cation exchange resin contacted with the mineral acid solution with washing water such as pure water or ultrapure water may be included. By washing the purified cation exchange resin with washing water such as pure water or ultrapure water after contacting it with the mineral acid solution, recontamination of metal impurities and the like can be suppressed when removing the mineral acid solution from the purified cation exchange resin.

[0053] Examples of the washing water contacted with the cation exchange resin in the washing step include pure water and ultrapure water, and ultrapure water may be used from the viewpoint of suppressing contamination after purification.

[0054] The temperature of the washing liquid contacted with the cation exchange resin in the washing step is, for example, in the range of 0 to 30°C.

[0055] The drying temperature in the drying step is 80°C or lower, and for example, in the range of 40 to 80°C. The drying time in the drying step may be a time when the water content becomes 5% by weight or less. In the drying step, the absolute pressure during vacuum drying may be set to -0.05 MPa or lower.

[0056] When hydrochloric acid with a concentration of 3% by weight is passed through the dry ion exchange resin in an amount 25 times the volume ratio, the total amount of eluted metal impurities eluted is, for example, 7 μg / mL-R or less, and may be 5 μg / mL-R or less.

[0057] Regarding metal contamination during vacuum drying, usually a part (point) of the resin surface, which is usually spherical, comes into contact with the inside of the dryer. Therefore, the metal contamination from the device is less than that in the purification process of filling the ion exchange resin column with mineral acid. That is, since the metal contamination in the purification process of the cation exchange resin before drying has a greater influence than the metal contamination by drying, it is desirable to control the metal concentration contained in the purified cation exchange resin before drying.

[0058] As the dry ion exchange resin, a dry chelating resin, a dry cation exchange resin, and a dry anion exchange resin may be combined, or it may be combined with an anion exchange resin having a water content of 10% by weight or less, or an anion exchange resin having a water content of 6% by weight or less. In particular, the dry weak anion exchange resin is suitable for dry resins because it has higher heat resistance than strong anion exchange resins. By mixing a dry anion exchange resin with a dry chelating resin and a dry cation exchange resin, it is possible to capture metal in anionic form while reducing acid elution from the dry chelating resin and the dry cation exchange resin.

[0059] Examples of the dry anion exchange resin to be mixed with the dry chelating resin or the dry cation exchange resin include weak anion exchange resins. Examples of the anion exchange group of the weak anion exchange resin include primary to tertiary amino groups and glucamine groups that selectively react with boron. Chelating resins having a polyamine group are also weak anion exchange resins.

[0060] The dry ion exchange resin may be stored in the following gas barrier container whose interior in contact with the dry ion exchange resin is covered with a non-metallic material and whose water vapor permeability is 8 g / m for 24 hours. 2 It may be stored in the following gas barrier container whose water vapor permeability is 6 g / m for 24 hours. 2It may be stored in the following gas-barrier container. Examples of such gas-barrier containers include resin containers such as bags laminated with nylon / polyethylene or the like inside, and metal containers such as aluminum bags. The water vapor transmission rate is, for example, 15 g / m 2 for polyethylene, 0.1 g / m 2 for aluminum, and 6 g / m 2 for the low-barrier bag manufactured by AS ONE (refer to https: / / www.ady-jp.jp / category / 1213991.html). The water vapor transmission rate can be measured by the method of JIS K7129 (the amount of water vapor passing through a test piece of unit area per unit time under predetermined temperature and humidity conditions). When storing in a gas-barrier container, it may be purged with an inert gas such as nitrogen and sealed.

[0061] Specific examples of the method for manufacturing the above-mentioned dry ion exchange resin will be described later.

[0062] <Purification method of the liquid to be treated> The method for purifying the liquid to be treated according to this embodiment is a method of purifying a liquid to be treated containing metal impurities using the dry ion exchange resin obtained by the method for manufacturing the above-mentioned dry ion exchange resin to reduce the amount of contained metal impurities.

[0063] The liquid to be treated to be purified is a liquid purified by an ion exchange resin, such as a liquid for manufacturing, and is used in the manufacture of electronic components such as flat panel displays (FPD) such as semiconductor integrated circuits (IC), liquid crystal displays (LCD), imaging elements (CCD, CMOS), and various recording media such as CD-ROM and DVD-ROM (collectively referred to as electronic industrial products). It includes chemicals, solvents such as dissolution solvents, and electronic materials (including electronic materials themselves, raw materials of electronic materials, and their dissolution solvents).

[0064] The chemical solution contains hydrogen peroxide, hydrochloric acid, sulfuric acid, hydrofluoric acid, phosphoric acid, acetic acid, citric acid, tartaric acid, oxalic acid, lactic acid, malonic acid, tetramethylammonium hydroxide, aqueous ammonium fluoride, etc. This is because even in the purification of an aqueous solution, it is better for the fluctuation of the water concentration in the aqueous solution to be treated to be small due to the introduction of the water content of the resin.

[0065] The solvent contains organic solvents such as acetone, 2-butanone, n-butyl acetate, ethanol, methanol, 2-propanol, toluene, xylene, propylene glycol methyl ether acetate, N-methyl-2-pyrrolidinone, ethyl lactate, phenolic compounds, dimethyl sulfoxide, tetrahydrofuran, γ-butyrolactone, polyethylene glycol monomethyl ether (PGME), polyethylene glycol monomethyl ether acetate (PGMEA). In particular, a dry chelate resin purified by the above method for producing a dry ion exchange resin can be applied to non-aqueous solvents (non-aqueous media) such as polyethylene glycol monomethyl ether (PGME), polyethylene glycol monomethyl ether acetate (PGMEA), and their mixtures.

[0066] As electronic materials, etc., semiconductor-related materials (resists, strippers, antireflection films, interlayer insulation film coating agents, coating agents for buffer coat films, etc.), flat panel display (FPD) materials (photo resists for liquid crystals, materials for color filters, alignment films, sealants, liquid crystal mixtures, polarizing plates, reflectors, overcoat agents, spacers, etc.) are included.

[0067] As the liquid to be treated, it can be applied to all non-aqueous liquids in general. However, for organic solvents such as alcohols, esters, and ketones, especially ester-based organic solvents that are prone to hydrolysis when contacted with cation exchange resins. For example, when purifying polyethylene glycol monomethyl ether (PGME), polyethylene glycol monomethyl ether acetate (PGMEA), or their mixtures, etc., the dried chelating resin purified by the above method for producing a dried ion exchange resin can be applied. By using the dried chelating resin purified by the above method for producing a dried ion exchange resin, the elution of moisture from the dried chelating resin is small, and the decomposition of hydrolyzable solvents such as polyethylene glycol monomethyl ether acetate (PGMEA) hardly occurs.

[0068] Specific examples of the method for purifying the liquid to be treated using the dried ion exchange resin obtained by the above method for producing a dried ion exchange resin will be described later.

[0069] <Examples of the method for producing a dried ion exchange resin and the production apparatus> Hereinafter, the method for producing a dried ion exchange resin (purification method) and the production apparatus (purification apparatus) according to the present embodiment will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram showing the overall configuration of the production apparatus 1 for the dried ion exchange resin. The production apparatus 1 for the dried ion exchange resin shown in FIG. 1 is an apparatus in which a purification apparatus and a drying apparatus are integrated.

[0070] The production apparatus 1 for the dried ion exchange resin in FIG. 1 includes an ion exchange resin column 10 as a purification means for obtaining a purified cation exchange resin by bringing a cation exchange resin to be purified into contact with a mineral acid solution having a content of metal impurities of 1 mg / L or less and a concentration of 5 wt% or more. The production apparatus 1 may include a mineral acid solution tank 12 for storing the mineral acid solution and a drain tank 14 for storing drain liquid and the like.

[0071] In the manufacturing apparatus 1, the outlet of the mineral acid solution tank 12 and the supply port, for example, at the upper part of the ion exchange resin column 10 are connected by a pipe 26 via a pump 16, and the discharge port, for example, at the lower part of the ion exchange resin column 10 and the inlet of the drainage tank 14 are connected by a pipe 28. A pH meter 22 may be installed in the pipe 28 as pH measuring means for measuring the pH of the drainage.

[0072] A pipe 30 is connected to the washing water supply port, for example, at the upper part of the ion exchange resin column 10, and a pipe 32 is connected to the washing drainage discharge port, for example, at the lower part of the ion exchange resin column 10. In the pipe 32 a specific resistance meter (conductivity meter) 24 may be installed as specific resistance / conductivity measuring means for measuring the specific resistance or conductivity of the washing drainage.

[0073] The ion exchange resin column 10 is configured to have a storage chamber. The storage chamber is made of a resin material such as a fluororesin, and has a supply port for supplying the mineral acid solution therein and a discharge port for discharging it to the outside. Inside the storage chamber, a cation exchange resin 36 to be purified is stored and filled on a perforated plate / mesh 40. In the ion exchange resin column 10, the mineral acid solution supplied from the supply port passes through the cation exchange resin 36 and is discharged to the outside from the discharge port, whereby the cation exchange resin 36 is purified. Also, in the ion exchange resin column 10, the washing water supplied from the washing water supply port passes through the cation exchange resin 36 and is discharged to the outside from the washing drainage discharge port, whereby the cation exchange resin 36 is washed.

[0074] The manufacturing apparatus 1 includes a heater 38 and a vacuum pump 20 as drying means for drying the purified cation exchange resin 36 under reduced pressure at 80°C or lower to a moisture content of 5% by weight or less. The heater 38 is installed so as to be able to heat the purified cation exchange resin 36 in the ion exchange resin column 10. For example, it is installed so as to cover at least a part of the outside of the ion exchange resin column 10 in which the purified cation exchange resin 36 is stored. The vacuum pump 20 is a pump for reducing the pressure inside the ion exchange resin column 10, and the suction side of the vacuum pump 20 and the suction port, for example, at the upper part of the ion exchange resin column 10 are connected by a pipe 34 via a moisture trap 18.

[0075] A mineral acid solution is stored in the mineral acid solution tank 12. This mineral acid solution is a mineral acid solution having a content of metal impurities of 1 mg / L or less and a concentration of 5% by weight or more.

[0076] When the pump 16 is driven in the manufacturing apparatus 1, the mineral acid solution in the mineral acid solution tank 12 is supplied through the pipe 26 toward the supply port of the ion exchange resin column 10. A plurality of pumps 16 may be provided in the pipe path according to the flow rate of the mineral acid solution required for purification.

[0077] The mineral acid solution is supplied from the supply port, and the mineral acid solution passes through the cation exchange resin 36, for example, in a downward flow (liquid passing) and is discharged from the discharge port, whereby the mineral acid solution is brought into contact with the cation exchange resin 36 to be purified and purification is performed (purification step). The drained liquid discharged from the discharge port is stored in the drain tank 14 through the pipe 28 as required.

[0078] The total metal impurity elution amount eluted when the purified cation exchange resin 36 purified by this purification treatment (treatment for reducing metal impurities) is passed through hydrochloric acid having a concentration of 3% by weight in a volume ratio of 25 times is 5 μg / mL-R or less. Thereby, a high-quality purified cation exchange resin with a small amount of metal impurities can be obtained.

[0079] In this embodiment, the cation exchange resin 36 is stored and filled in the storage chamber of the ion exchange resin column 10 used in the manufacturing apparatus 1, and the purification treatment (treatment for reducing contained metal impurities) is performed by passing a mineral acid solution through it. However, the purification treatment may also be performed by immersing the cation exchange resin in the mineral acid solution in a storage state.

[0080] In the purification process, the pH of the drained liquid may be measured by the pH meter 22 installed in the pipe 28. Based on the pH of the drained liquid measured by the pH meter 22, it is possible to determine whether to dispose of it as acidic waste liquid.

[0081] After passing the mineral acid solution and reducing the amount of contained metal impurities, the cation exchange resin 36 may be washed with washing water such as ultrapure water. For example, the washing water is supplied through the pipe 30 toward the washing water supply port of the ion exchange resin column 10. The washing water is supplied from the washing water supply port, and the washing water passes through (flows through) the cation exchange resin 36, for example, in a downward flow for washing. Drain By being discharged from the water discharge port, the washing water is brought into contact with the cation exchange resin 36 to be washed, and washing is performed (washing process). In the washing process, the ion exchange resin column 10 functions as a washing means. The washing Drain The washing waste water discharged from the water discharge port is discharged through the pipe 32. A washing liquid such as pure water or ultrapure water may be stored in the mineral acid solution tank 12 or in a separately provided tank, and the washing liquid may be supplied from the tank to the ion exchange resin column 10 by a pump or the like.

[0082] By this washing treatment, a high-quality purified ion exchange resin with an extremely small amount of contained metal impurities can be obtained.

[0083] In this embodiment, the washing treatment is performed by storing and filling the cation exchange resin 36 in the storage chamber of the ion exchange resin column 10 used in the manufacturing apparatus 1 and passing the washing water through it. However, the washing may also be performed by immersing the cation exchange resin in the washing water in a storage state.

[0084] In the cleaning process, the specific resistance or conductivity of the cleaning wastewater may be measured by a specific resistance meter (conductivity meter) 24 installed in the pipe 32. The cleaning with cleaning water may be performed until the specific resistance or conductivity of the cleaning wastewater measured by the specific resistance meter (conductivity meter) 24 becomes less than a predetermined value. In addition to the specific resistance value (conductivity), a TOC meter may be installed as TOC measuring means to measure TOC, and the cleaning with cleaning water may be performed until it becomes less than a predetermined value set in advance.

[0085] After the purification process or the cleaning process is completed, a drying process is performed. For example, the vacuum pump 20 is started, the storage chamber of the ion exchange resin column 10 is depressurized to a vacuum state, and it is heated by the heater 38, and the purified cation exchange resin 36 may be dried under reduced pressure at 80 ° C or lower until the water content becomes 5% by weight or less (drying process). Thereby, a dried ion exchange resin with a reduced water content and metal content can be obtained.

[0086] FIG. 2 shows another example of an apparatus for producing a dried ion exchange resin. The apparatus 3 for producing a dried ion exchange resin shown in FIG. 2 is an apparatus in which a purification apparatus and a drying apparatus are separate bodies.

[0087] The apparatus 3 for producing a dried ion exchange resin in FIG. 2 includes an ion exchange resin column 10 as purification means for obtaining a purified cation exchange resin by bringing a mineral acid solution having a content of metal impurities of 1 mg / L or less and a concentration of 5% by weight or more into contact with the cation exchange resin to be purified. The production apparatus 3 may include a mineral acid solution tank 12 for storing the mineral acid solution and a drain tank 14 for storing drain liquid and the like.

[0088] In the production apparatus 3, the outlet of the mineral acid solution tank 12 and, for example, the upper supply port of the ion exchange resin column 10 are connected by a pipe 26 via a pump 16, and the lower discharge port of the ion exchange resin column 10 and the inlet of the drain tank 14 are connected by a pipe 28. A pH meter 22 may be installed in the pipe 28 as pH measuring means for measuring the pH of the drain liquid.

[0089] For example, a pipe 30 is connected to the upper cleaning water supply port of the ion exchange resin column 10, and a pipe 32 is connected to the lower cleaning drainage outlet of the ion exchange resin column 10. In the pipe 32 a resistivity / conductivity meter 24 may be installed as resistivity or conductivity measuring means for measuring the resistivity or conductivity of the cleaning drainage.

[0090] The ion exchange resin column 10 is configured to have a storage chamber, and has a supply port for supplying a mineral acid solution therein and a discharge port for discharging to the outside. Inside the storage chamber, a cation exchange resin 36 to be purified is stored and filled on a mesh plate / mesh 40.

[0091] The manufacturing apparatus 3 includes a drying apparatus 42 and a vacuum pump 20 as drying means for drying the purified cation exchange resin under reduced pressure at 80°C or lower to a water content of 5% by weight or less. The drying apparatus 42 is an apparatus capable of accommodating and heating the purified cation exchange resin taken out from the ion exchange resin column 10. The drying apparatus 42 may be, for example, an apparatus that accommodates the purified cation exchange resin taken out from the ion exchange resin column 10 and heats it through a heat medium from outside the container. The vacuum pump 20 is a pump for reducing the pressure inside the drying apparatus 42, and the suction side of the vacuum pump 20 and, for example, the upper suction port of the drying apparatus 42 are connected by a pipe 44 via a moisture trap 18.

[0092] A mineral acid solution is stored in the mineral acid solution tank 12. This mineral acid solution is a mineral acid solution having a content of metal impurities of 1 mg / L or less and a concentration of 5% by weight or more.

[0093] When the pump 16 is driven in the manufacturing apparatus 3, the mineral acid solution in the mineral acid solution tank 12 is supplied through the pipe 26 toward the supply port of the ion exchange resin column 10. A plurality of pumps 16 may be provided in the pipe path according to the flow rate of the mineral acid solution required for purification.

[0094] A mineral acid solution is supplied from a supply port, and the mineral acid solution passes through (flows through) the cation exchange resin 36, for example, in a downward flow and is discharged from a discharge port, whereby the mineral acid solution is brought into contact with the cation exchange resin 36 to be purified, and purification is performed (purification step). The drainage discharged from the discharge port is stored in the drainage tank 14 through the pipe 28 as necessary.

[0095] The cation exchange resin 36 purified by this purification treatment (treatment for reducing metal impurities) has a total metal impurity elution amount of 5 μg / mL-R or less when eluted when hydrochloric acid with a concentration of 3% by weight is passed through in a volume ratio of 25 times. As a result, a high-quality purified cation exchange resin with a small amount of metal impurities can be obtained.

[0096] In the present embodiment, the purification treatment (treatment for reducing metal impurities) is performed by storing and filling the cation exchange resin 36 in the storage chamber of the ion exchange resin column 10 used in the manufacturing apparatus 3 and passing a mineral acid solution through it. However, the purification treatment may be performed by immersing the cation exchange resin in a mineral acid solution in a storage state.

[0097] In the purification step, the pH of the drainage may be measured by the pH meter 22 installed in the pipe 28. Based on the pH of the drainage measured by the pH meter 22, it is possible to determine whether to dispose of it as acid waste liquid.

[0098] After passing the mineral acid solution and reducing the amount of metal impurities contained, the cation exchange resin 36 may be washed with washing water such as ultrapure water. For example, the washing water is supplied through the pipe 30 toward the washing water supply port of the ion exchange resin column 10. Washing water is supplied from the washing water supply port, and the washing water passes through (flows through) the cation exchange resin 36, for example, in a downward flow for washing Drain and is discharged from the washing water discharge port, whereby the washing water is brought into contact with the cation exchange resin 36 to be washed, and washing is performed (washing step). In the washing step, the ion exchange resin column 10 functions as a washing means. Washing DrainThe cleaning wastewater discharged from the water discharge port is discharged through the pipe 32. Cleaning liquid such as pure water or ultrapure water may be stored in the mineral acid solution tank 12 or in a separately provided tank, and the cleaning liquid may be supplied from the tank to the ion exchange resin column 10 by a pump or the like.

[0099] By this cleaning treatment, a high-quality purified ion exchange resin with an extremely small amount of contained metal impurities can be obtained.

[0100] In addition, in the present embodiment, the cation exchange resin 36 is stored and filled in the storage chamber of the ion exchange resin column 10 used in the manufacturing apparatus 3, and the cleaning treatment is performed by passing cleaning water through it. However, the cleaning may be performed by immersing the cation exchange resin in the cleaning water in a storage state.

[0101] In the cleaning process, the specific resistance or conductivity of the cleaning wastewater may be measured by the specific resistance meter (conductivity meter) 24 installed in the pipe 32. The cleaning with cleaning water may be performed until the specific resistance or conductivity of the cleaning wastewater measured by the specific resistance meter (conductivity meter) 24 becomes less than a predetermined value. In addition to the specific resistance value (conductivity), a TOC meter may be installed as TOC measuring means to measure TOC, and the cleaning with cleaning water may be performed until it becomes less than a predetermined value set in advance.

[0102] After the completion of the purification process or the cleaning process, a drying process is performed. For example, the purified cation exchange resin taken out from the ion exchange resin column 10 is accommodated in the drying device 42. The vacuum pump 20 is started, the inside of the drying device 42 is depressurized to a vacuum state, and heated, and the purified cation exchange resin may be dried under reduced pressure at 80 °C or lower to a moisture content of 5% by weight or less (drying process). Thereby, a dried ion exchange resin with a reduced moisture content and metal content can be obtained.

[0103] In the manufacturing apparatuses 1 and 3, the liquid contact parts (for example, the internal flow path of the pump 16, the inner walls of the pipes 26 and 28, the liquid contact parts such as the inner wall of the storage chamber of the ion exchange resin column 10, the inside of the mineral acid solution tank 12 and the drain tank 14, etc.) that come into contact with the mineral acid solution may be formed or coated with a material that is inert to the mineral acid solution. Thereby, the liquid contact parts are inert to the mineral acid solution, and it is possible to reduce the influence such as elution of metal impurities from the liquid contact parts to the cation exchange resin.

[0104] Examples of the material that is inert to the mineral acid solution and is used for the liquid contact parts include fluororesins, polypropylene resins, polyethylene resins, etc., and fluororesins can be mentioned from the viewpoint of metal elution and the like. Examples of fluororesins include PTFE (tetrafluoroethylene resin), PFA (tetrafluoroethylene-perfluoroalkoxyethylene copolymer resin), ETFE (tetrafluoroethylene-ethylene copolymer resin), FEP (tetrafluoroethylene-hexafluoropropylene copolymer resin), PVDF (vinylidene fluoride resin), ECTFE (ethylene-chlorotrifluoroethylene resin), PCTFEP (chlorotrifluoroethylene resin), PVF (vinyl fluoride resin), etc.

[0105] <Examples of the method for purifying the liquid to be treated and the purification apparatus> Hereinafter, the method for purifying the liquid to be treated and the purification apparatus according to this embodiment will be described with reference to the drawings. FIG. 3 is a schematic configuration diagram showing the overall configuration of the purification apparatus 5 for the liquid to be treated.

[0106] The purification apparatus 5 for the liquid to be treated in FIG. 3 includes an ion exchange resin column 50 as a liquid to be treated purification means for bringing the liquid to be treated to be purified into contact with the dried ion exchange resin obtained as described above for purification. The purification apparatus 5 may include a liquid to be treated tank 52 for storing the liquid to be treated and a treated liquid tank 58 for storing the treated liquid. The purification apparatus 5 may further include a pretreatment liquid tank 54 for storing the pretreatment liquid and a drain tank 56 for storing the drain liquid.

[0107] In the purification device 5, the outlet of the liquid to be treated tank 52 and the liquid to be treated supply port, for example, at the upper part of the ion exchange resin column 50 are connected by a pipe 66 via a pump 60, and the treated liquid discharge port, for example, at the lower part of the ion exchange resin column 50 and the inlet of the treated liquid tank 58 are connected by a pipe 74.

[0108] The outlet of the pretreatment liquid tank 54 and the pretreatment liquid supply port, for example, at the upper part of the ion exchange resin column 50 are connected by a pipe 68 via a pump 62, and the drain discharge port, for example, at the lower part of the ion exchange resin column 50 and the inlet of the drain tank 56 are connected by a pipe 70.

[0109] A pipe 72 is connected to the cleaning water supply port, for example, at the upper part of the ion exchange resin column 50, and a pipe 76 is connected to the cleaning drainage discharge port, for example, at the lower part of the ion exchange resin column 50. A resistivity meter (conductivity meter) 64 may be installed in the pipe 76 as resistivity / conductivity measuring means for measuring the resistivity or conductivity of the cleaning drainage.

[0110] The liquid to be treated, which is the object to be purified, is stored in the liquid to be treated tank 52.

[0111] The ion exchange resin column 50 is configured to have a storage chamber. The storage chamber is made of a resin material such as a fluororesin, etc., and has a supply port for supplying the liquid to be treated inside and a discharge port for discharging to the outside. Inside the storage chamber, the dried ion exchange resin 78 obtained as described above is stored and filled on the mesh plate / mesh 80. The ion exchange resin column 50 is arranged such that the liquid to be treated supplied from the supply port passes through the dried ion exchange resin 78 and is discharged to the outside from the discharge port, thereby purifying the liquid to be treated. The dried ion exchange resin 78 is obtained by the above-described method and apparatus for producing dried ion exchange resin, and the total amount of eluted metal impurities eluted when hydrochloric acid with a concentration of 3% by weight is passed through in a volume ratio of 25 times is 5 μg / mL-R or less, and the content of metal impurities inside has been reduced in advance by a treatment so that the amount of contained metal impurities is extremely small.

[0112] When the pump 60 is driven in the purification device 5, the liquid to be treated in the liquid to be treated tank 52 is supplied through the pipe 66 toward the supply port of the ion exchange resin column 50. A plurality of pumps 60 may be provided in the pipe path according to the flow rate of the liquid to be treated required for purification.

[0113] The liquid to be treated is supplied from the supply port, and the liquid to be treated passes (flows through) the dry ion exchange resin 78, for example, in a downward flow and is discharged from the discharge port, whereby the liquid to be treated to be purified is brought into contact with the dry ion exchange resin 78 for purification (liquid to be treated purification step). The supply port is provided at the lower part of the storage chamber of the ion exchange resin column 50, and the storage chamber is filled with the liquid to be treated or a solution having the same composition as the liquid to be treated, or a solution that can be quickly replaced with the liquid to be treated, in an upward flow, and after the air bubbles inside the resin are pushed out of the storage chamber, it passes (flows through) in a downward flow and is discharged from the discharge port, whereby the liquid to be treated to be purified may be brought into contact with the dry ion exchange resin 78 for purification. The treated liquid discharged from the discharge port is stored in the treatment liquid tank 58 through the pipe 74 as necessary. The treatment liquid before reaching the target moisture content, the mixed liquid of the pretreatment liquid described below and the liquid to be treated, etc. may be stored in the drain tank 56 through the pipe 70 as necessary.

[0114] By this purification treatment (treatment for reducing metal impurities contained), the amount of metal impurities contained in the treatment liquid (for example, the content of each metal element is 1000 μg / L or less) is, for example, 10 μg / L or less. Further, the moisture content of the obtained treatment liquid is, for example, 100 ppm or less. Thereby, a high-quality treatment liquid with a low moisture content and a low amount of metal impurities contained can be obtained.

[0115] By bringing it into contact with a mineral acid solution having an extremely low content of metal impurities and further drying it under reduced pressure, an ion exchange resin column is constructed using a dried ion exchange resin with reduced water content and internal metal impurity content. In the purification treatment (treatment for reducing metal impurities) of the liquid to be treated using this ion exchange resin column, elution of water and metal impurities into the treatment liquid can be reduced. Thereby, a high-purity treatment liquid with a low water content and a low content of metal impurities can be obtained.

[0116] In the present embodiment, purification treatment (treatment for reducing metal impurities) is performed by storing and filling the dried ion exchange resin 78 in the storage chamber of the ion exchange resin column 50 used in the purification apparatus 5 and passing the liquid to be treated through it. However, the purification treatment may be performed by immersing the dried ion exchange resin in the liquid to be treated in a storage state.

[0117] When using a liquid to be treated with low affinity for water, a pretreatment liquid with higher affinity for water than the liquid to be treated may be used. When the pump 62 is driven in the purification apparatus 5, the pretreatment liquid in the pretreatment liquid tank 54 is supplied through the pipe 68 toward the supply port of the ion exchange resin column 50.

[0118] The pretreatment liquid is supplied from the supply port, and the pretreatment liquid passes through (flows through) the dried ion exchange resin 78, for example, in a downward flow and is discharged from the discharge port, thereby bringing the pretreatment liquid into contact with the dried ion exchange resin 78 to perform pretreatment (pretreatment step). The pretreated drainage discharged from the discharge port is stored in the drainage tank 56 through the pipe 70 as necessary.

[0119] By this pretreatment, the liquid to be treated and the dried ion exchange resin become more compatible, and ionic impurities are more likely to diffuse into the ion exchange resin. Also, when using a liquid to be treated with low affinity for water, by using a pretreatment liquid with higher affinity for water than the liquid to be treated, it becomes easier to replace the slightly remaining water inside the resin with the pretreatment liquid.

[0120] When the liquid to be treated is a non-aqueous liquid and it is to be used again after being converted back to the H form, the dry ion exchange resin 78 immersed in the liquid to be treated may be washed with washing water such as ultrapure water and then regenerated to the H form with a mineral acid or the like. For example, the washing water is supplied through the pipe 72 toward the washing water supply port of the ion exchange resin column 50. The washing water is supplied from the washing water supply port, and the washing water passes through (flows through) the dry ion exchange resin 78, for example, in a downward flow for washing. Drain By being discharged from the water discharge port, the washing water is brought into contact with the dry ion exchange resin 78 to be washed, and washing is performed (washing step). In the washing step, the ion exchange resin column 50 functions as a washing means. Washing Drain The washing waste water discharged from the water discharge port is discharged through the pipe 76.

[0121] By this washing treatment, it can be regenerated to the H form again. It may also be used in a disposable manner without regeneration.

[0122] The liquid contact parts (for example, the internal flow path of the pump 60, the inner walls of the pipes 66, 74, the inner walls of the storage chambers of the ion exchange resin column 50, etc., the inside of the liquid to be treated tank 52 and the treated liquid tank 58, etc.) where the purification device 5 comes into contact with the liquid to be treated or the treated liquid may be formed or coated with a material that is inert to the liquid to be treated. Thereby, the liquid contact parts are inert to the liquid to be treated, and the influence such as elution of metal impurities from the liquid contact parts into the liquid to be treated can be reduced.

[0123] Examples of the material that is inert to the liquid to be treated and used for the liquid contact parts include fluororesins, polypropylene resins, polyethylene resins, etc. From the viewpoint of metal elution and the like, fluororesins can be mentioned. Examples of fluororesins include PTFE (tetrafluoroethylene resin), PFA (tetrafluoroethylene-perfluoroalkoxyethylene copolymer resin), ETFE (tetrafluoroethylene-ethylene copolymer resin), FEP (tetrafluoroethylene-hexafluoropropylene copolymer resin), PVDF (vinylidene fluoride resin), ECTFE (ethylene-chlorotrifluoroethylene resin), PCTFEP (chlorotrifluoroethylene resin), PVF (vinyl fluoride resin), etc.

[0124] When the purification device 5 further has a filtering means such as a filter for removing impurity fine particles contained in the processing liquid in at least one of the front stage and the rear stage of the ion exchange resin column 50, not only the eluted metal impurities in the processing liquid but also the impurity fine particles can be reduced, and a higher purity processing liquid can be obtained. The processing liquid processed using the purification device 5 may be further distilled, or the distilled liquid obtained by distillation may be further processed using the purification device 5.

Example

[0125] Hereinafter, examples and comparative examples will be given to explain the present invention more specifically and in detail, but the present invention is not limited to the following examples.

[0126] <Analysis method> [Analysis of moisture concentration] The amount of moisture (mass ppm) in the non-aqueous solvent means the value measured by the Karl Fischer method using a Karl Fischer volumetric moisture meter (manufactured by Hiranuma Sangyo Co., Ltd., Aquacounter AQ-2200). ppm indicates the mass ratio of water to the target solution.

[0127] [Analysis of trace metals] Each metal concentration was analyzed using an Agilent 8900 triple quadrupole ICP-MS (trade name, manufactured by Agilent Technologies, Inc.).

[0128] [Analysis of acetic acid] The acetic acid concentration (ppm) in PGMEA was measured using a capillary electrophoresis system Agilent 7100 (trade name, manufactured by Agilent Technologies, Inc.).

[0129] <Ion exchange resin> The ion exchange resin used is as follows. ·DS-2: Gel type strong basic anion exchange resin, manufactured by Organo Corporation (Aurite), resin material: styrene-divinylbenzene copolymer, type of ion exchange group: quaternary amine group ·DS-4: Macroporous strongly acidic cation exchange resin, manufactured by Organo Corporation (Aurolite), resin material: styrene-divinylbenzene copolymer, type of ion exchange group: sulfonic acid group ·DS-21: Macroporous chelating resin, manufactured by Organo Corporation (Aurolite), resin material: styrene-divinylbenzene copolymer, type of ion exchange group (chelating group): aminophosphonic acid group ·DS-22: Macroporous chelating resin, manufactured by Organo Corporation (Aurolite), resin material: styrene-divinylbenzene copolymer, type of ion exchange group (chelating group): iminodiacetic acid group ·IRA96SB: Macroporous weakly basic anion exchange resin, manufactured by Organo Corporation (AMBERLITE (trademark)), resin material: styrene-divinylbenzene copolymer, type of ion exchange group: tertiary amino group ·IRC76: Macroporous weakly acidic cation exchange resin, manufactured by Organo Corporation (Amberlite (trademark) series), resin material: acrylic resin, type of ion exchange group: carboxyl group

[0130] <Example 1: Solvent replacement amounts of strongly acidic cation exchange resin, strongly basic anion exchange resin, and chelating resin> A PFA column was filled with 50 mL each of chelating resin DS-21, strongly acidic cation exchange resin DS-4, and strongly basic anion exchange resin DS-2 in a water-wet state, and isopropyl alcohol (IPA) (manufactured by Tokuyama, Toxo IPA SE grade) with a water concentration of 30 ppm was supplied at SV = 5 h -1 until the bed volume (BV) (L / L-R) reached 30. The water concentration (ppm) in the IPA at the column outlet was analyzed to confirm the effect of solvent replacement. The results are shown in Table 1 and Figure 4.

[0131]

Table 1

[0132] The strong cation exchange resin DS-4 and the strong anion exchange resin DS-2 showed 205 ppm and 332 ppm respectively at 20 BV, and the water concentration was not reduced to the same level as the stock solution. On the other hand, the chelating resin DS-21 with a weakly acidic cation group reduced the water concentration to the same level as the stock solution at 15 BV. It was confirmed that the bound water bound to the functional group interacted more strongly with the strong cation exchange group and the strong anion exchange group.

[0133] <Example 2: Solvent replacement amount of chelating resin and dry chelating resin> The chelating resin DS-21 was contacted with 5 wt% hydrochloric acid having a metal concentration of 1 mg / L or less as a mineral acid solution to purify the H-form chelating resin, and the resulting resin was used as the wet resin. A part of this wet resin was dried under reduced pressure at 80 °C for 24 hours or more to obtain a dry chelating resin with a water content of 2 wt% or less.

[0134] The obtained wet resin and dry resin were packed into a PFA column in the same manner as in Example 1, and PGMEA (manufactured by Tokyo Ohka Kogyo Co., Ltd.) with a water concentration of 50 ppm was supplied at SV = 5 h -1 and the supply was continued until the bed volume (BV) (L / L-R) reached 10. The water concentration (ppm) in the PGMEA at the column outlet was analyzed to confirm the effect of solvent replacement. The results are shown in Fig. 5.

[0135] As a result, the largest difference was observed in the water concentration in the PGMEA immediately after the liquid passage (5 BV), and it was confirmed that the resin elution water concentration was significantly reduced by drying.

[0136] <Example 3: Exchange capacity before and after drying (chelating resin, weak cation exchange resin, weak anion exchange resin), vacuum drying at 80 °C> Wet resins and dry resins of H-form chelating resin DS-21, H-form chelating resin DS-22, H-form and weak cation exchange resin IRC76, and weak anion exchange resin IRA96SB were obtained in the same manner as in Example 2. The water content of the dry resins was 2% or less for the chelating resin and the weak cation exchange resin, and 10% or less for the weak anion exchange resin.

[0137] The exchange capacities of the obtained wet resin and dry resin were measured. The exchange capacity was measured by adding an H-form chelating resin to an aqueous sodium hydroxide solution, immersing it at 25 °C overnight (18 hours), and titrating the OH consumption with that without the chelating resin added. The exchange capacity of the dry resin was measured after immersing the dried product in pure water at 25 °C overnight (18 hours). IRA96SB in the free base form was dried under the same conditions as above and the exchange capacity was calculated by titration. The results are shown in Table 2.

[0138]

Table 2

[0139] As a result, for all resins, the functional groups were maintained during drying under reduced pressure at 80 °C, and almost no decrease in the exchange capacity due to heating was observed.

[0140] <Comparative Example 1: Exchange capacities before and after drying (weak cation exchange resin, weak anion exchange resin), drying under reduced pressure at 180 °C> A weak cation exchange resin IRC76 and a weak anion exchange resin IRA96SB similar to those in Example 3 were dried at 180 °C for 18 hours, and the exchange capacity of the obtained dried product was evaluated by the same method as in Example 3. The results are shown in Table 3.

[0141]

Table 3

[0142] As a result, it was confirmed that the exchange capacity of the sample resin decreased due to drying at a temperature exceeding the maximum operating temperature.

[0143] <Example 4: Metal contents before and after drying of clean chelating resin> The H-shaped chelating resin was purified by contacting it with 5 wt% hydrochloric acid containing a metal concentration of 1 mg / L or less. When hydrochloric acid with a concentration of 3 wt% was passed through the purified chelating resin in an amount 25 times the volume ratio, the amount of eluted metal impurities was measured using ICP-MS (inductively coupled plasma mass spectrometer, manufactured by Agilent Technologies), and the metal content was analyzed. The metal content of the wet product immediately after purification and its dried product was analyzed. The dried product was obtained by allowing the wet resin to stand in a vacuum dryer and then performing vacuum drying at 80 °C for 24 hours under a pressure of 0 kPa to obtain a dried chelating resin with a water content of 2 wt% or less. The results are shown in Table 4.

[0144]

Table 4

[0145] As a result of analyzing the metal content, no metal was found to increase extremely after drying. Therefore, it can be said that the dried chelating resin obtained in this test is a dried chelating resin with a high degree of cleanliness.

[0146] <Example 5, Comparative Example 2: Purification of a non-aqueous solvent using a dried chelating resin> A PFA resin column (inner diameter: 16 mm, height: 30 mm) was filled with 36 mL of the wet chelating resin (Comparative Example 2) and the dried chelating resin (Example 5) described in Example 3. The dried chelating resin had its dry weight of 36 mL measured in advance when immersed in PGMEA, and the dried resin was made into a slurry using 1 BV of PGMEA (trade name: PM thinner, manufactured by Tokyo Ohka Kogyo Co., Ltd.) and filled into the PFA column.

[0147] There, the pre-adjusted PGMEA simulation solution was brought into contact from the upper part of the column. The simulation solution was adjusted by adding a standard solution for ICP-MS (manufactured by SPEX) to PGMEA (trade name: PM thinner, manufactured by Tokyo Ohka Kogyo Co., Ltd.). Then, the adjusted simulation solution was brought into contact with the resin at SV5, and the moisture concentration and metal concentration in the PGMEA obtained from the column outlet after 1 hour (BV5) were analyzed. The obtained results were compared with the moisture concentration and metal concentration in the PGMEA before purification (stock solution), and the moisture elution concentration and metal removal amount were compared. The results are shown in Table 5.

[0148]

Table 5

[0149] When the dry chelating resin (Example 5) was used, the moisture elution concentration was low.

[0150] <Example 6: Moisture and acetic acid concentrations in the PGMEA solution> To confirm the influence of the moisture eluted from the resin on PGMEA, which is a hydrolyzable solvent, PGMEA (trade name: PM thinner, manufactured by Tokyo Ohka Kogyo Co., Ltd.) was brought into contact with the H-form chelating resin DS-22, which is a wet chelating resin prepared by the method described in Example 2, to obtain a resin treatment solution. PGMEA (Comparative Example 3) containing 0.6% by weight of moisture at the initial stage of liquid passing was further passed through, and resin-treated PGMEA containing 0.05% by weight of moisture was obtained with the reduction of the moisture elution amount. These resin treatment solutions were stored at room temperature (20 ± 5°C) for 14 days, and the acetic acid concentration after storage was measured. The results are shown in Table 6.

[0151]

Table 6

[0152] As a result, it was confirmed that the lower the moisture concentration, the less acetic acid was generated, and it was confirmed that using the dry chelating resin has the effect of suppressing the increase in the acetic acid concentration in PGMEA during storage due to the moisture eluted from the resin.

[0153] <Examples 7 and 8: Moisture Content and Metal Elution Amount (Gas-Barrier Bag, PE Bag)> A dry resin of chelating resin DS-21 H form was obtained in the same manner as in Example 2. The moisture content was 1% by weight. As a gas-barrier container, 30 g of the obtained dry resin was filled into a Lamidip LZ-10 (manufactured by Seiniichi) with the inner material being nylon / polyethylene laminate (water vapor permeability: 3 - 5 g / m 2 ·24 hours), sealed with a heat sealer, then transferred into an aluminum bag with a humidity of 90% or more, and left standing in a thermostat at 40°C for 10 days. A moist towel was placed in the aluminum bag, and the resin-filled container was placed on a stand above the towel so that the resin-filled container did not contact the towel. As Example 8, 30 g of the obtained dry resin was filled into a Unipack (manufactured by Seiniichi) made of polyethylene (PE), put into the said aluminum bag, and stored under the same conditions. The moisture content of the resin after 10 days of storage was measured. It was heated at 105°C overnight, and the moisture content was calculated from the mass before and after drying. The results are shown in Table 7. The exact water vapor permeability of the PE container described in Example 8 is unknown, but there is a literature stating that the water vapor permeability of PE is 15.2 g / m 2 ·24 hours (https: / / www.ady-jp.jp / category / 1213991.html).

[0154] <Comparative Example 4> As Comparative Example 4, a dry resin of chelating resin DS-21 H form was obtained in the same manner as in Example 2. The moisture content was 1% by weight. 30 g of the said dry resin was placed on a petri dish, left standing in an aluminum bag with a humidity of 90% or more in the same manner as in Examples 7 and 8, the aluminum bag was sealed, and left standing in a thermostat at 40°C for 10 days. The moisture content of the resin after 10 days of storage was measured. It was heated at 105°C overnight, and the moisture content was calculated from the mass before and after drying. The results are shown in Table 7.

[0155]

Table 7

[0156] When stored under conditions of higher temperature and higher humidity than in a general laboratory, Example 7 had a smaller increase in moisture content than Example 8, and the effect of using a gas barrier container was obtained. Conversely, Comparative Example 4, which was stored without using a gas barrier container under high humidity conditions, had a significantly increased water content.

[0157] As described above, it was possible to obtain a dried ion exchange resin with reduced moisture content and metal content. Further, by purifying a non-aqueous solvent, which is a liquid to be treated, using the dried ion exchange resin obtained in the examples, it was possible to obtain a high-quality treated liquid with a low moisture content and a small amount of metal impurities contained therein.

Explanation of Signs

[0158] 1,3 Production apparatus, 5 Purification apparatus, 10,50 Ion exchange resin column, 12 Mineral acid solution tank, 14,56 Drain tank, 16,60,62 Pump, 18 Moisture trap, 20 Vacuum pump, 22 pH meter, 24,64 Resistivity meter (conductivity meter), 26,28,30,32,34,44,66,68,70,72,74,76 Pipe, 36 Cation exchange resin, 38 Heater, 40,80 Mesh / plate, 42 Drying apparatus, 52 Liquid to be treated tank, 54 Pretreatment liquid tank, 58 Treated liquid tank, 78 Dried ion exchange resin.

Claims

1. A purification step of obtaining a purified cation exchange resin by contacting a cation exchange resin to be purified with a mineral acid solution having a content of contained metal impurities of 1 mg / L or less and a concentration of 5% by weight or more, wherein the total amount of eluted metal impurities eluted when hydrochloric acid having a concentration of 3% by weight is passed through the purified cation exchange resin in an amount 25 times the volume ratio is 5 μg / mL-R or less; and A drying step of obtaining a dried ion exchange resin by drying the purified cation exchange resin under reduced pressure at 80° C. or lower to a water content of 5% by weight or less; comprising The cation exchange resin is a chelating resin or a weak cation exchange resin; The dried ion exchange resin is for purification such that the content of each metal after purification of the hydrolyzable solvent is 1 ppb or less for each metal. A method for producing a dried ion exchange resin characterized by this.

2. A method for producing a dried ion exchange resin according to claim 1, wherein the contents of sodium (Na), calcium (Ca), magnesium (Mg), and iron (Fe) in the mineral acid solution used in the purification step are each 200 μg / L or less. A method for producing a dried ion exchange resin characterized by this.

3. A method for producing a dried ion exchange resin according to claim 1 or 2, wherein in the drying step, the dried cation exchange resin obtained by drying under reduced pressure is mixed with an anion exchange resin having a water content of 10% by weight or less to obtain the dried ion exchange resin. A method for producing a dried ion exchange resin characterized by this.

4. A method for producing a dried ion exchange resin according to any one of claims 1 to 3, wherein the cation exchange resin has an aminomethylphosphonic acid group or an iminodiacetic acid group as a chelating group. A method for producing a dried ion exchange resin characterized by this.

5. A method for producing a dried ion exchange resin according to any one of claims 1 to 4, wherein the cation exchange resin is a weak cation exchange resin, and in the drying step, drying is performed under reduced pressure such that the exchange capacity after drying exceeds 92.5% of the exchange capacity before drying. A method for producing a dried ion exchange resin characterized by this.

6. The dry ion exchange resin obtained by the method for producing a dry ion exchange resin according to any one of claims 1 to 5 is placed in a container whose interior in contact with the dry ion exchange resin is covered with a non-metallic material and whose water vapor permeability for 24 hours is 8 g / m ２ The method for producing a dry ion exchange resin, characterized by storing it in the following container.

7. A purification means for obtaining a purified cation exchange resin by bringing a cation exchange resin to be purified into contact with a mineral acid solution having a content of metal impurities of 1 mg / L or less and a concentration of 5% by weight or more, wherein the total amount of eluted metal impurities eluted when hydrochloric acid having a concentration of 3% by weight is passed through the purified cation exchange resin in an amount 25 times the volume ratio is 5 μg / mL-R or less. A drying means for obtaining a dried ion exchange resin by subjecting the purified cation exchange resin to reduced-pressure drying at 80°C or lower until the water content is 5% by weight or less. Comprising The cation exchange resin is a chelating resin or a weak cation exchange resin. The dried ion exchange resin is for purification such that the metal concentration after purification of the hydrolyzable solvent is 1 ppb or less for each metal. A manufacturing apparatus for a dried ion exchange resin characterized by this.

8. A manufacturing apparatus for a dried ion exchange resin according to claim 7, The drying means includes a heater installed so as to cover at least a part of the outside of a column in which the purified cation exchange resin is stored, and a pump for reducing the pressure inside the column. A manufacturing apparatus for a dried ion exchange resin characterized by this.

9. A manufacturing apparatus for a dried ion exchange resin according to claim 7, The drying means includes a drying device for accommodating and heating the purified cation exchange resin, and a pump for reducing the pressure inside the drying device. A manufacturing apparatus for a dried ion exchange resin characterized by this.

10. A manufacturing apparatus for a dried ion exchange resin according to any one of claims 7 to 9, The cation exchange resin is a weak cation exchange resin, and in the drying means, reduced-pressure drying is performed so that the exchange capacity after drying exceeds 92.5% of the exchange capacity before drying. A manufacturing apparatus for a dried ion exchange resin characterized by this.

11. Using the dried ion exchange resin obtained by the method for manufacturing a dried ion exchange resin according to any one of claims 1 to 6, as the hydrolyzable solvent, a method for purifying a liquid to be treated having a water concentration of 1% by weight or less and having ionic impurities.

12. A liquid to be treated purification apparatus comprising a liquid to be treated purification means for purifying a liquid to be treated having a water concentration of 1% by weight or less and having ionic impurities as the hydrolyzable solvent, using the dried ion exchange resin obtained by the manufacturing apparatus for a dried ion exchange resin according to any one of claims 7 to 10.

Images