Purifying agent and method for producing the same

Abstract

To provide a purifying agent having high ion-trapping capability.SOLUTION: A purifying agent comprises a polymer of a chelating agent bonded to the surface of carbon.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to the configuration of a purifying agent for removing harmful compounds and reaction-inhibiting components obtained by introducing a chelating agent capable of removing specific components onto carbon.

Background Art

[0002] Removing components that have an adverse effect on the living environment and reaction-inhibiting components that cause a decrease in reactions are important means as chemical methods. A so-called purifying agent that is put into environmental water, reaction solutions, etc., binds to unnecessary components, and is then recovered and removed as it is, is widely used. Examples of unnecessary components include metals and hydrophobic compounds. Chelating agents that introduce ligands that form chelate complexes, collect metals, and perform removal have been variously studied and are commercially available. For removing metals from wastewater in the neutral range, chelating agents using inexpensive and physically stable inorganic substances such as silica gel, alumina, and diatomaceous earth as carriers are commercially available. However, they are unstable in solutions such as alkaline and acidic solutions, and a neutralization step etc. becomes necessary, increasing the labor. Also, due to the influence of non-specific adsorption, the range of use is limited. Therefore, devices such as forming a resin film such as a styrene-divinylbenzene resin or a methacrylate resin on the silica gel surface to suppress non-specific adsorption of metals and introducing a chelating agent have been made. It is also applied to cartridges for solid-phase extraction (Patent Document 1). Ligand introduction methods using polymer resins with higher chemical stability, such as polystyrene resin and methacrylate resin, as carriers have also been variously studied, and polymer-based chelating agents are widely used (Patent Documents 2 to 4). Furthermore, a chelating agent in which a ligand is introduced using a composite of silica gel with high physical stability and a polymer with strong chemical properties as a carrier has also been proposed (Patent Document 5). However, polymers have low heat resistance and swell when the temperature rises, becoming unusable. Among porous polymers generally effective as purifying agents, some break at 60°C, and the temperature at which they can be used with confidence is less than 60°C. Therefore, it could not be used for the direct purification of hot water at 60°C or higher, such as hot spring sources and cooling wastewater. In addition, when organic solvents are mixed, there is a problem that swelling and shrinkage occur, the effect of the introduced ligand changes, and it cannot be recovered, so it could not be used for the purification of solutions containing organic solvents. Therefore, the conditions under which conventional composites with polymers and inorganic substances can be used are limited. There is a need for a new purifying agent that does not swell even in organic solvents or at temperatures from 60°C to 120°C and can be used stably.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Patent Document 7

Patent Document 8

Patent Document 9

Patent Document 10

Patent Document 11

Summary of the Invention

Problems to be Solved by the Invention

[0004] In order to solve these problems, it is necessary to use a carrier that does not swell in an organic solvent, does not swell or shrink even at a temperature of 70 °C or higher, and does not cause non-specific adsorption of metals. Solid carbon materials mainly composed of carbon are chemically inert, have no non-specific adsorption, and are suitable as carriers. Conventionally, this solid carbon material has been widely used for catalysts and the like, and various surface treatments have been studied. There have been disclosed a carrier for a platinum catalyst (Patent Document 6), a composite in which carbon is embedded in a porous resin (Patent Document 7), a hydrophilized adsorbent in which hydrophilic-treated silica is attached to activated carbon (Patent Document 8), a hydrophobized adsorbent in which hydrophobic-treated silica is attached to activated carbon (Patent Document 9), a material having an ion-exchange ability in which an ion-exchange group is directly introduced onto the surface of a carbon material (Patent Document 10), and the like. Research has also been conducted on graphene oxide obtained by oxidizing carbon nanotubes and introducing iminodiacetic acid, and there are reports as a chelating agent. However, the purposes of these carbon materials are catalysts, adsorbents, ion-exchange materials, etc., and for the removal of harmful compounds and unnecessary components, the loading amount is small and they are not satisfactory as purifying agents. When attaching surface-treated silica to carbon to increase the loading amount, non-specific adsorption due to the silanol activity of silica occurs, and affected by the adsorptive matrix, unnecessary components cannot be collected with good reproducibility. Even if they can be collected, they are strongly adsorbed and cannot be easily washed away. Regeneration is also impossible. In the case of a material in which an ion-exchange group is directly introduced into carbon, ionic compounds can be collected, but hydrophobic compounds cannot be collected. The hydrophobic retention characteristics of carbon cannot be utilized, and the introduction amount of the ion-exchange phase is also limited by the physical properties such as the surface area of carbon, so the component loading amount is reduced. In a situation where various matrices are mixed, it is affected and unnecessary components cannot be adsorbed and removed. Research has also been conducted on functional carbon materials obtained by introducing ion-exchange groups into multilayered graphene and functional carbon materials obtained by polymerizing polyamine on the surface of carbon nanotubes. However, they are difficult to handle and synthesize inexpensively in large quantities. There is still a long way to go before they can be put into practical use as purified materials. In addition, a method for producing a composite in which a metal oxide is immobilized on a carbon substrate has been proposed, in which a metal chelate solution containing a metal component constituting the metal oxide and an organic chelating agent is applied to the carbon substrate and heat-treated (Patent Document 11). However, the above technique only adds a metal oxide on the carbon substrate, and a chelating material chemically bonded to carbon is required.

[0005] The present disclosure has been made in view of the above circumstances, and the main object thereof is to provide a purifying agent having high ion-trapping performance.

Means for Solving the Problems

[0006] That is, the present disclosure includes the following aspects. <1> A purifying agent in which a polymer of a chelating agent is bonded to the surface of carbon.

[0007] <2> A method for producing a purifying agent, in which a chelating agent is introduced onto the surface of carbon, and the chelating agent is polymerized.

[0008] <3> A method for producing a purifying agent, in which the surface of carbon is hydrophilized, a reactive functional group is introduced into a chelating agent, and the chelating agent having the reactive functional group introduced therein is polymerized on the hydrophilized surface of the carbon to bond the chelating agent to the surface of the carbon.

[0009] <4> A method for producing a purifying agent, in which the surface of carbon is hydrophilized, a reactive functional group is introduced into a chelating agent, the chelating agent having the reactive functional group introduced therein is polymerized, A method for producing a purifying agent, which comprises introducing the polymerized chelating agent onto the surface of the hydrophilically treated carbon and binding the chelating agent to the surface of the carbon.

[0010] <5> The hydrophilization treatment is to introduce a hydrophilic group onto the surface of the carbon and polymerize the carbon onto which the hydrophilic group has been introduced, thereby forming a hydrophilic film on the surface of the carbon. The method for producing a purifying agent according to <3> or <4> above.

Advantages of the Invention

[0011] The purifying agent of the present disclosure has high ion-trapping performance.

Brief Description of the Drawings

[0012]

Figure 1

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Figure 8

Embodiments for Carrying Out the Invention

[0013] Hereinafter, embodiments according to the present disclosure will be described. Matters other than those specifically mentioned in this specification and necessary for the implementation of the present disclosure (for example, general configurations and manufacturing processes of purifying agents that do not characterize the present disclosure) can be grasped as design matters of those skilled in the art based on the prior art in the relevant field. The present disclosure can be implemented based on the content disclosed in this specification and common general knowledge in the relevant field.

[0014] In the present disclosure, a purifying agent is provided in which a polymer of a chelating agent is bonded to the surface of carbon. The surface of the carbon may be hydrophilized and a hydrophilic film may be formed.

[0015] In the present disclosure, by using chemically stable carbon as a carrier, a hydrophilic film (hydrophilic resin) phase that does not deteriorate, swell, or shrink even in an environment of 60°C or higher or in an organic solvent is formed, and chelation is performed, so that a purifying agent that can be stably used can be provided. By using carbon as a carrier, it is also possible to expect an effect that unnecessary hydrophobic components can be removed, and the range of applications other than for metals is also expanded.

[0016] The carbon used for the retention body is not particularly limited as long as it is a solid such as non-swelling particles, films, or monoliths having chemical resistance, thermal stability, and conductivity. Carbon produced by an activation method that controls the surface area, etc. according to the firing temperature of the carbon material, carbon obtained by putting a carbon material in a mold and removing the mold, carbon obtained by granulating a fine carbon body, carbon nanotubes produced by chemical vapor deposition, carbon monoliths obtained by firing a polymer porous body, carbon black obtained by burning oil or hydrocarbons, activated carbon obtained by high-temperature carbonization of plants, etc., graphite carbon obtained by crystallization by high-temperature treatment, etc. can be used. In the method of directly bonding an ion exchange group to the carbon surface polar group, the amount of component collected increases as the surface area of the carbon increases. However, when the surface area increases, the physical strength decreases and it becomes difficult to use. As commercially available products, 2000 m 2 / g is the limit, and there are often various matrices. As a purifying agent, the loading amount is too small. In the present disclosure, as will be described later, surface polymerization hydrophilic treatment (sometimes referred to as hydrophilic treatment) is performed so as not to receive physical adsorption of carbon. Therefore, unlike conventional ion exchange materials, it is less likely to be affected by the physical properties of carbon. As the surface area, carbon having a value greater than 0 and less than or equal to 2000 m 2 / g that is sold as a commercially available product can be used. As long as it is a recoverable solid, the shape is not particularly limited. If it is a film-like carbon nanotube, it can be passed through a liquid, attached to the inner surface of a container, or if it is solid, it can be mixed in a solution. It may be in the form of a film or a cylinder, but considering the dispersion reproducibility, particulate form is easy to use. Particulate carbon in the range of about 1 nm to 1 mm that is easy to recover is suitable.

[0017] Examples of conventional commercially available products are shown below, but are not limited thereto. Commercially available products such as Denka Black series of Denka Co., Ltd., UF series of Resonac Co., Ltd., Triporus of Sony Corporation, Carbon Black series of Mitsubishi Chemical Corporation, and Nobel series of Toyo Tanso Co., Ltd. can be applied.

[0018] In the method for producing the purifying agent of the present disclosure, a chelating agent may be introduced onto the surface of carbon and the chelating agent may be polymerized. Examples of the reaction form of the hydrophilic treatment of the carbon surface are shown below. The formation of the resin phase (hydrophilic film) may be carried out with any reactive hydrophilic reagent as long as the reaction can be stably controlled, and is not limited to the following examples. Figure 1 is a reaction diagram showing the direct introduction of N-(3-Aminopropyl)methacrylamide (aminopropyl methacrylamide) as a chelating agent onto carbon to form a hydrophilic film and chelation. The detailed synthesis conditions are shown in Example 1. Since the chelating agent can be freely introduced onto the carbon, a purifying agent having sufficient chelating ability is obtained. In this way, by introducing a chelating agent and polymerizing it on a carbon carrier, a purifying agent having sufficient chelating ability and capable of being stably used is obtained.

[0019] In the method for producing the purifying agent of the present disclosure, the surface of carbon may be hydrophilically treated, a reactive functional group may be introduced into the chelating agent, the chelating agent having the reactive functional group introduced therein may be polymerized on the hydrophilically treated surface of the carbon, and the chelating agent may be bonded to the surface of the carbon. For example, first, a hydrophilic film may be formed on the carbon, and then a chelating agent may be introduced to obtain a purifying agent. Since it can be introduced in two steps, it can be controlled more finely than the direct introduction process in Figure 1. In the present disclosure, since the purpose is purification, a monomer having a reactive functional group such as a vinyl group may be introduced in the first step, and the carbon may be hydrophilically resinized so as not to swell even at high temperatures. Figure 2 is a reaction diagram showing the introduction of acryloyl chloride into the hydroxy group of carbon as the first step. The detailed synthesis of Figure 2 is described in Example 2. Figure 3 is a reaction diagram showing the introduction of epichlorohydrin into the hydroxy group of carbon in the first step. Any method may be used as long as it can form a hydrophilic phase, and it is not limited to these examples. The synthesis details of Figure 3 are described in Example 3.

[0020] The hydrophilic treatment may form a hydrophilic film on the surface of the carbon by introducing a hydrophilic group onto the surface of the carbon and polymerizing the carbon onto which the hydrophilic group has been introduced. As the hydrophilic treatment (surface polymerization hydrophilic treatment), coating with a hydrophilic polymer such as polyacrylamide, polyepoxy, or polyvinyl alcohol may be used. However, hydrophilization by polymerization of hydrophilic monomers, epoxy acrylate, acrylamide, hydroxymethacrylate, acrylyl chloride, acrylic acid, methacrylic acid, 2,3-dihydroxypropyl methacrylate, 2-hydroxyethyl acrylate, hydroxypropyl methacrylate, N-(2-hydroxypropyl) methacrylamide, 2-hydroxy-3-phenoxypropyl methacrylate, etc. can also be applied. When the thickness of the hydrophilic film is reduced, hydrophobic reaction inhibitors such as polycyclic aromatics can be adsorbed and removed due to the hydrophobicity and stereoselectivity of the carbon itself. Conversely, when it is desired to enhance the chelating ability, the thickness of this hydrophilic film may be increased to enhance the chelating effect. After the hydrophilic film is formed, a chelating agent is introduced. Also, by controlling the hydrophilic phase, the swelling property and temperature durability in the solvent can be adjusted. In the present disclosure, it may be adjusted so as not to deteriorate by swelling at 60°C to 120°C.

[0021] Next, a chelating agent is introduced. As an example, a method of introducing a reactive functional group such as a vinyl group into a chelating agent that does not have a reactive functional group such as a vinyl group and then bonding it to the hydrophilic-treated carbon will be described. There are many chelating agents that do not have a reactive functional group, but a vinyl group can be easily introduced. Figure 4 is a reaction diagram showing the introduction of acryloyl chloride into the chelating agent diethylenetriamine as the second step. The synthesis details are described in Example 2. Any method can be used as long as a reactive functional group such as a vinyl group can be introduced. Any compound with a chelating effect can be used. Commercially available compounds as follows can be used. Examples of compounds with a chelating effect include the following. Complexants: IDA (iminodiacetic acid), NTA (nitrilotriacetic acid), EDTA (ethylenediaminetetraacetic acid), CyDTA (t-1,2-Cyclohexanediaminetetraacetic Acid), DTPA (Diethylenetriamine-N,N,N’,N’’,N’’-pentaacetic acid), GEDTA (O,O’-Bis(2-aminoethyl) ethyleneglycol-N,N,N’,N’ -tetraacetic acid). Ethylenediamines: EDA (ethylenediamine), DETA (diethylenetriamine), TETA (triethylenetetramine), TEPA (tetraethylenepentamine), Carboxylic acid monomers: Acrylic acid, methacrylic acid, fumaric acid, maleic acid. Amine monomers: Allylamine, N-Allylmethylamine, N,N-Dimethylallylamine, Allylurea, N,N-Diethylallylamine, N-[2-(Dimethylamino)ethyl]acrylamide, N-(3-Dimethylaminopropyl)methacrylamide, N-[3-(Dimethylamino)propyl]acrylamide, N-[2-(Diethylamino)ethyl]acrylamide, N-[2-(Dimethylamino)ethyl]methacrylamide, N-(3-Aminopropyl)methacrylamide, N-(2-Aminoethyl)methacrylamide. Ion exchange CX series: Styrenesulfonic acid, Vinylsulfonic acid, 2-Acrylamido-2-methylpropane-1-sulfonate. Ion exchange AX series: (3-Acrylamidopropyl)trimethylammonium.

[0022] Figure 5 shows an example of a reaction in which, in the first-stage reaction shown in Figure 2, diethylenetriamine having a vinyl group introduced therein is introduced as the second stage into carbon into which a reactive functional group such as a vinyl group has been introduced. The detailed reaction conditions are described in Example 2.

[0023] Figure 6 shows an example of a reaction in which, in the first-stage reaction shown in Figure 3, a chelating agent is introduced as the second stage into carbon into which an epoxy group has been introduced. As shown in Figure 6, the chelating agent may be introduced after the introduction of the epoxy group in Figure 3.

[0024] The method for producing the purifying agent of the present disclosure hydrophilizes the surface of carbon, introduces a reactive functional group into a chelating agent, polymerizes the chelating agent into which the reactive functional group has been introduced, introduces the polymerized chelating agent onto the surface of the hydrophilized carbon, and may bond the chelating agent to the surface of the carbon. Alternatively, a chelating agent may be polymerized in advance to form a prepolymer, and the compound may be polymerized while being introduced into hydrophilized carbon. Without being affected by the physical properties of carbon, a large amount of chelating agent can be introduced, and the removal ability of unnecessary components can be enhanced. However, it is essential to control the reaction conditions so that it does not swell even at 70 to 120°C. Figure 7 shows, as the second step, a reaction example in which a reagent having a vinyl group introduced into diethylenetriamine is polymerized, and the polymer is introduced into carbon hydrophilized in the first-step reaction. Detailed conditions are described in Example 4. With a reaction initiator, polymerization can be carried out to increase the introduction amount of the chelating agent.

[0025] Figure 8 shows a reaction example in which a hydrophilic film is formed on carbon into which reactive functional groups such as vinyl groups are introduced by polymerization of an epoxy monomer, and a chelating agent is introduced onto the surface. As shown in Figure 8, a hydrophilic film may be formed on carbon into which reactive functional groups such as vinyl groups are introduced by polymerization of an epoxy monomer, and a chelating agent may be introduced onto the surface. The synthesis conditions are described in Example 3.

[0026] In the first step, if a reaction method can introduce a hydrophilic film (hydrophilic resin) into carbon and it is confirmed that it does not swell even at 60 to 120°C, and subsequently a chelating agent can be introduced, any method can be used.

[0027] [Application to the conductive material of a lithium-ion secondary battery] In a lithium-ion secondary battery, there is a possibility of battery short circuit caused by foreign substances in the cell, and foreign substance reduction during battery manufacturing and foreign substance dissolution treatment in the activation process after cell manufacturing are carried out. Although these measures suppress the outflow of defective batteries, when foreign substances that dissolve and precipitate during charge and discharge are encapsulated in the materials in the electrode, or when a positive electrode potential higher than the foreign substance dissolution treatment is locally applied to a deteriorated battery, there is a possibility that a phenomenon such as short circuit may occur with a delay after battery manufacturing depending on the type of battery and the form of existence of foreign substances. In the present disclosure, in addition to the prevention of foreign matter from entering the battery and the promotion of dissolution (i.e., detection of defective cells) in the activation process after the entry, the purification agent of the present disclosure is applied as a foreign matter trap in the electrode as a countermeasure against foreign matter that may remain slightly in the battery. This can adsorb metal ions such as Fe ions and Cu ions and trap impurities that can cause battery short circuits. In the present disclosure, as a means to reduce the influence on battery reactions and electrode strength (peeling strength, flexibility), the purification agent of the present disclosure can be applied as a conductive material in the electrodes of lithium-ion secondary batteries. In the present disclosure, a battery provided with the purification agent of the present disclosure in the positive electrode, negative electrode, or both of a lithium-ion secondary battery can be provided.

Examples

[0028] (Example 1) Direct introduction of a reactive chelating agent into carbon black #2650 and polymerization: 20 g of a carbon support (carbon black #2650, surface area 370 m 2 / g, average particle size 13 nm, manufactured by Mitsubishi Chemical) was placed in a three-necked flask, 500 mL of acetonitrile was added, and the mixture was stirred and dispersed. Next, 0.5 g of benzoyl peroxide and 10 g of N-(3-Aminopropyl)methacrylamide were weighed in, and the mixture was stirred and reacted at room temperature for 12 h under nitrogen purge. After the reaction, unreacted reagents were removed by filtration to obtain hydrophilized carbon. Furthermore, the hydrophilized carbon was ultrasonically washed in 500 mL of methanol for 15 minutes and then filtered and washed. The same washing operation was performed three times, and the washed hydrophilized carbon was dried under reduced pressure at 80 °C. Thereby, a purification agent was obtained.

[0029] (Example 2) Introduction of a vinylated chelate monomer prepared in Triporus WP-001 two-step reaction AC carbon and polymerization: [First step] AC carbon 100 g of a carbon support (Triporus WP-001, average particle size 10 μm, manufactured by Sony) was placed in a stirring reaction tank, and 1 L of acetonitrile was added and stirred to disperse it. Next, 10 g of acryloyl chloride (AC) was weighed out and stirred at room temperature for 12 h to cause a reaction. After the reaction, unreacted acryloyl chloride was removed by filtration to obtain AC-carbon. Further, the AC-carbon was ultrasonically washed in 1 L of methanol for 15 minutes and then filtered and washed. The same washing operation was performed three times, and the washed AC-carbon was dried under reduced pressure at 100 °C. A part was sampled and it was confirmed by microscope that it was not broken. [Second stage] Chelation (introduction of vinylated chelate monomer and polymerization) Chelation was carried out using a radical polymerization method. 500 mL of acetonitrile was placed in a stirring reaction tank, and then 50 mL of diethylenetriamine was added and stirred. Next, 50 mL of acryloyl chloride was added dropwise over 1 hour, and a triethylenetetramine (TETA)-modified monomer was prepared by stirring and reacting at room temperature under nitrogen. Next, 100 g of AC-carbon and 1 g of AIBN (azoisobutyronitrile) were each placed in 500 mL of acetonitrile and added to the reaction tank. After the addition, it was heated to reflux at about 80 °C and reacted for 5 hours to obtain a carbon chelate resin. Next, it was filtered and washed to remove unreacted substances. It was ultrasonically washed in 1 L of methanol for 15 minutes and then filtered. Using the same washing method, it was washed again twice with methanol, and then in the order of tetrahydrofuran, acetone, and methanol. The washed carbon chelate was dried under reduced pressure at 100 °C for 15 h. Thus, a purifying agent was obtained.

[0030] (Example 3) After the epoxy reaction of Denka Black Li-100 three-stage reaction AC-carbon, hydrolysis chelation: [First stage] AC-carbon black 50 g of carbon black carrier (Denka Black Li-100, surface area 68 m 2 / g, average particle size of several tens of nm, manufactured by Denka) was taken and 1 L of acetonitrile was added and stirred to disperse. Next, 10 g of acryloyl chloride (AC) was weighed and placed in the above stirring reaction tank and stirred at room temperature (about 20 °C) for 12 hours to react. After the reaction, unreacted acryloyl chloride was removed by filtration, and the AC-treated carbon black of the filtrate was ultrasonically washed with 2 L of methanol for 15 minutes and then filtered. The same operation was performed three times, and the washed AC-treated carbon black was dried under reduced pressure at 100 °C. A part was collected and it was confirmed by microscope that it was not broken. [Second stage] Epoxidized carbon black Next, 20 g of AC-treated carbon black was taken in a three-necked flask, 500 mL of acetonitrile was added and stirred. Then, 10 mL of glycidyl methacrylate (GMA) and 0.1 g of AIBN were added, and the mixture was heated to reflux at about 80 °C and reacted for 5 h to obtain an epoxidized carbon black resin. After the reaction, unreacted substances were removed by filtration with a Buchner funnel. The epoxidized carbon black resin of the filtrate was transferred to a beaker and ultrasonically washed with 1 L of methanol for 15 minutes and then filtered with a Buchner funnel. The same operation was performed three times, and the same washing was also performed once each with tetrahydrofuran and acetone. The washed epoxidized carbon black was dried under reduced pressure at 80 °C. [Third stage] Chelation Iminodiacetic acid was used as a chelating agent for the chelation of epoxidized carbon black resin. 4 g of iminodiacetic acid was weighed into a 250 mL stoppered bottle, and 50 mL of 0.2 mol / L sodium hydroxide aqueous solution and 50 mL of methanol were added and dissolved. Next, 5 g of epoxidized carbon black resin was added, and the reaction was carried out by stirring at 60 °C for 15 h. After the reaction, unreacted substances were removed by filtration with a Buchner funnel. The carbon black chelate resin of the filtrate was transferred to a hollow beaker, ultrasonically washed with 200 mL of water for 15 minutes, and filtered with a Buchner funnel. The same operation was performed twice, and washing was also performed once each with methanol and acetone. The washed carbon black chelate resin was dried under reduced pressure at 80 °C. Thus, a purifying agent was obtained.

[0031] (Example 4) Introduction of vinylated chelate polymer prepared on graphite carbon UF-G30 two-stage reaction AC graphite carbon: [First stage] AC graphite carbon 50 g of a graphite carbon carrier (graphite carbon UF-G30, surface area 15 m 2 / g, average particle size 10 μm, manufactured by Resonac) was placed in a stirring reaction tank, and 500 mL of acetonitrile was added and stirred for dispersion. Next, 5 g of acryloyl chloride (AC) was weighed and stirred at room temperature for 12 h for reaction. After the reaction, unreacted acryloyl chloride was removed by filtration to obtain AC graphite carbon. Further, the AC graphite carbon was ultrasonically washed in 1 L of methanol for 15 minutes and subjected to filtration washing. The same washing operation was performed 3 times, and the washed AC graphite carbon was dried under reduced pressure at 120 °C. A part was sampled and confirmed with a microscope that it was not broken. [Second stage] Chelation (introduction of vinylated chelate polymer) 500 mL of acetonitrile was placed in a stirring reaction tank, and then 20 mL of diethylenetriamine and 0.1 g of AIBN (azoisobutyronitrile) were added and stirred. Next, 10 mL of acryloyl chloride was added dropwise over 1 hour, and after the addition, the mixture was stirred and reacted at 40 °C under nitrogen to prepare a TETA polymer solution. 50 g of AC-graphite carbon and 0.5 g of AIBN (azoisobutyronitrile) were each placed in 500 mL of acetonitrile and put into a reaction vessel. 500 mL of the previously prepared TETA polymer solution was added, and after stirring at room temperature for 1 hour, the mixture was heated to reflux at about 80 °C and reacted for 5 hours to obtain a carbon chelate resin. Next, it was filtered and washed to remove unreacted substances. It was ultrasonically washed with 1 L of methanol for 15 minutes and then filtered. Using the same washing method, it was washed again twice with methanol, followed by tetrahydrofuran, acetone, and methanol in that order. The washed carbon chelate was dried under reduced pressure at 100 °C for 15 h. Thereby, a purifying agent was obtained.

[0032] (Example 5) The removal performance of the purifying agents prepared in Examples 1 to 4 (sometimes referred to as Examples 1 to 4) was confirmed. Concentration 1×10 -4 M of Cu 2+ To 10 mL of a solution (about pH 5), 0.1 g or 0.01 g of each purifying agent from Examples 1 to 4 was added and shaken. The solution was collected with a disposable filter. 3 mL of the collected solution was taken, and 3 mL of 2-(5-bromo-2-pyridylazo)-5-[N-n-propyl-N-(3-sulfopropyl)amino]phenol (5-Br-PAPS) with a concentration of 1×10 -4 M was added and measured with a spectrophotometer. The maximum concentration of the complex at this time was 5×10 -5 M. The results are shown in Table 1.

[0033]

Table 1

[0034] From Example 1 to Example 4, all were 1×10 -4mol / L × 0.01L / 0.1g = 1×10 -5 mol / g = 10 μmol / g or higher, indicating sufficient scavenging ability and sufficient removal capacity as a purifying agent for reaction inhibitors was confirmed. In the case of 0.01 g, since the recovery rate is around 70%, 1×10 -4 mol / L × 0.01L / 0.01g × 0.7 = 7×10 -5 mol / g = 70 μmol / g. The maximum adsorption capacity is 70 μmol / g, confirming high removal capacity. For all the purifying agents, it was demonstrated that the liquid permeability was not deteriorated, there was no swelling or shrinkage against temperature and organic solvents, and they were not broken. Therefore, the purifying agent of the present disclosure has sufficient performance for removing unnecessary components.

[0035] (Example 6) The removal performance of the purifying agents prepared in Examples 1 to 4 was confirmed. [Test method] A glass syringe was filled with 0.5 g each of the purifying agents of Examples 1 to 4 and untreated Triporous WP - 001S - 10μm (Comparative Example 1), UF - G30 (Comparative Example 2) for comparison, and 5 mL of electrolyte was passed through for conditioning. Subsequently, 10 mL of the test solution was passed through, and the filtrate * was collected for ICP measurement. ICP - MS: 7700x manufactured by Agilent Technologies The test solution used was Fe 4.4 mg / L and Cu 6.1 mg / L. *Filtrate: 1 mL of the filtrate immediately after passing the test solution was discarded, and the remaining liquid was collected. The quotient obtained by dividing the concentration of the eluate by the sample concentration is the removal rate. The results are shown in Table 2. With untreated carbon, removal may not be possible, but with the purifying agent of the present disclosure, removal of 95% or more was achieved. Also, since there were no problems with passing the liquid and there was no coloring such as turbidity in the eluate, it can be seen that deterioration due to drying did not occur. It was demonstrated that the purifying agents of Examples 1 to 4 all have sufficient removal ability for metals.

[0036]

Table 2

[0037] (Example 7) The removal performance of the purifying agents prepared in Examples 1 to 4 was confirmed. [Test method] A glass syringe was filled with 0.1 g each of the purifying agents of Examples 1 to 4 and Triporous WP-001S-10μm (Comparative Example 1) and UF-G30 (Comparative Example 2) that had not been treated for comparison, and conditioned by passing 5 mL of 100% methanol through it. As the test solution, a solution prepared by accurately weighing 0.2 g each of uracil and naphthalene and dissolving them in 100 mL of methanol was used. Thereafter, 10 mL of 100% test solution was passed through, the filtrate* was collected and subjected to HPLC analysis to obtain the sample concentration of the eluate. *Filtrate: 1 mL of the filtrate immediately after passing the test solution was discarded, and the remaining solution was collected. The quotient obtained by dividing the eluate concentration by the sample concentration is the removal rate. The results are shown in Table 3. Since uracil was not adsorbed and was eluted, it can be seen that physical adsorption due to gel breakage did not occur. On the other hand, naphthalene, which is an organic substance, could be removed by 95% or more. With the untreated carbon, the organic substances could not be removed and the eluate turned orange. Also, it was confirmed that it was possible to pass 100% methanol through, and it was demonstrated that the purifying agent of the present disclosure does not swell in organic solvents.

[0038]

Table 3

[0039] Since the purifying agent using the carbon of the present disclosure as a carrier does not swell even in an organic solvent, the durability, which has been a problem conventionally, is improved, and metal collection can be easily performed with good reproducibility. In addition, due to the hydrophobic effect of carbon, hydrophobic reaction-inhibiting components can also be removed. The removal effect of these reactive-inhibiting components can be easily adjusted by controlling the thickness of the hydrophilic film. Moreover, since carbon has high heat resistance, it becomes a purifying agent that can be used even in a reaction field at 100°C.

Claims

1. A purifying agent in which a polymer of a chelating agent is bonded to the surface of carbon.

2. A method for producing a purifying agent, comprising introducing a chelating agent onto the surface of carbon and polymerizing the chelating agent.

3. subjecting the surface of carbon to a hydrophilic treatment, introducing a reactive functional group into the chelating agent, and polymerizing the chelating agent having the reactive functional group introduced thereon on the surface of the hydrophilic-treated carbon to bond the chelating agent to the surface of the carbon.

4. subjecting the surface of carbon to a hydrophilic treatment, introducing a reactive functional group into the chelating agent, polymerizing the chelating agent having the reactive functional group introduced thereon, and introducing the polymerized chelating agent onto the surface of the hydrophilic-treated carbon to bond the chelating agent to the surface of the carbon.

5. The method for producing a purifying agent according to claim 3 or 4, wherein the hydrophilic treatment comprises introducing a hydrophilic group onto the surface of the carbon and polymerizing the carbon having the hydrophilic group introduced thereon to form a hydrophilic film on the surface of the carbon.

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