KR0159977B1 - Process for preparing amidoxime chelate resin - Google Patents

Abstract

The present invention relates to a method for preparing an amidoximyl chelate resin, using an acrylonitrile monomer and tetraethylene glycol diacrylate as a crosslinking agent and suspending polymerization by adding a diluent to prepare a crosslinked polyacrylonitrile resin matrix. The polyacrylonitrile resin matrix is prepared by amidoximation with an NH ₂ OH aqueous solution or an NH ₂ OH-methanol solution to provide an amidoxime chelate resin having excellent adsorption capacity to metal ions.

Description

Manufacturing method of amidoxime chelate resin

The present invention relates to a method for preparing an amidoximyl chelate resin, and more particularly, to amidoxime chelate resin having excellent selective adsorption capacity to metal ions using tetraethyleneglycol diacrylate (TGDA) as a crosslinking agent. It relates to a manufacturing method.

Although the decisive disadvantage of chelate resins is that the adsorption rate of metal ions is lower than that of ion exchange resins, it has been pointed out that since it can express selective adsorption capacity for metal ions, continuous research and development has been made. In the case of chelate resins, crosslinked polystyrene (PS) is mainly used as a resin matrix constituting the chelate resin, and divinylbenzene (DVB) is used as a crosslinking agent.

However, DVB-crosslinked PS-based chelate resins have excellent physical durability, but since the resin matrix itself is extremely non-hydrophilic, metal ion adsorption capacity and adsorption rate are significantly reduced, and the introduction of chloromethylation process causes pollution and increases manufacturing cost. .

Therefore, in order to solve the drawbacks of the DVB crosslinked PS-based chelate resin, polyacrylonitrile (PAN) has recently begun to be tensioned. From PAN, a simple one-step reaction with NH ₂ OH solution can easily prepare an amidoxime chelate resin having excellent adsorption capacity for general heavy metal ions.

However, even in the amidoxime chelate resin derived from the crosslinked PAN resin matrix, when DVB is used as the crosslinking agent, it is difficult to obtain a chelate resin having excellent metal ion absolute adsorption capacity and adsorption rate unless special post-treatment processing is introduced. Thus, instead of DVB, an acrylate crosslinking agent such as ethylene glycol mid methacrylate (EGD), butanediol dimethacrylate (BDD), triethylene glycol methacrylate (TGD ₃ ), and tetraethylene glycol dimethacrylate (TGD) Is used and the related arts are as follows.

JP Publication No. 60-260423 aims to provide a method for effectively recovering Ga from an aqueous solution containing Ga using EGD and TGD as cross-linking agents when preparing a cross-linked PAN resin matrix, but depending on the shape of the chelate resin matrix Absolute adsorption capacity and adsorption rate vary so that the results of adsorption characteristics can vary.

JP Publication No. 62-182118 aims to provide a method for efficiently desorbing and recovering uranium ions adsorbed on a chelate resin having a dithiocarboxylic acid group using a TGD crosslinked PAN chelate resin. However, the TGD crosslinked chelate resin obtained in the above patent has a disadvantage in that the swelling becomes too large in an aqueous solution so that practical use is impossible.

JP Publication No. 58-49620 discloses a chelate resin that can efficiently recover Ga from Bayer's Solution, which is obtained as a by-product from an Al manufacturing process by obtaining an amidoxime chelate resin from a TGD or EGD crosslinked PAN resin matrix. It aims at providing a manufacturing method. However, when the adsorption results for Ga are compared with those of amidoxyl chelate resins prepared from DVB crosslinked PAN resin matrix, the synergistic effect of adsorption is hardly observed.

Therefore, the present invention solves the above problems by using TGDA as an acrylate-based crosslinking agent other than TGD and EGD, amidoxyl chelate resins that have significantly increased the absolute adsorption capacity and adsorption rate for metal ions such as Cd, Cr or Cu. An object of the present invention is to provide a manufacturing method.

Hereinafter, the present invention will be described in more detail.

In the present invention, a crosslinked PAN resin matrix is prepared by using TGDA as a crosslinking agent in preparing a crosslinked PAN resin matrix. When the degree of crosslinking is defined as the molar ratio (%) of TGDA to the total number of moles of acrylonitrile and TGDA, metal ion adsorption capacity is best when the degree of crosslinking of the resin matrix is changed by 5 to 20% by TGDA.

Since the PAN resin matrix has a difference in absolute adsorption capacity and adsorption rate of metal ions depending on appearance, in the present invention, a diluent is added to 30 to 200% (v / v) with respect to the mixed liquid volume of monomer and TGDA when preparing the resin matrix. A rough resin matrix is produced. It is preferable to use toluene as the diluent according to the present invention.

The resulting crosslinked PAN resin matrix is amidoxized to prepare an amidoxime type TGDA crosslinked PAN chelate resin. In the amidification process, the reaction is carried out at 50 to 90 ° C., preferably at 60 to 70 ° C. for 1 to 6 hours, preferably 3 to 5 hours, using NH ₂ OH aqueous solution or NH ₂ OH-methanol solution. At this time, the ratio of NH ₂ OH is used in the range of 1 to 4 mol, preferably 2 to 3 mol, based on the number of moles of acrylonitrile monomer constituting the polyacrylonitrile resin matrix. Methanol or water is used as the amidoxidization reaction solvent, and NH ₂ OH-methanol or NH ₂ OH aqueous solution is preferably added in the range of 100 to 500 ml with respect to 10 g of the polyacrylonitrile resin matrix to limit its use concentration. Do.

As described above, TGDA crosslinked PAN chelate resin obtained by amidoximating the resin matrix prepared using TGDA as a crosslinking agent was found to have excellent performance compared to conventional PAN chelate resins by examining metal ion adsorption capacity by metal ion adsorption experiment. .

Hereinafter, the present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the following examples.

Example 1

Step 1) Polymerization of TGDA Crosslinked PAN Resin Matrix

In a 1 L three-necked flask equipped with a mechanical stirrer, 400 ml of deionized water, 40 ml of 2% gelatin solution, 30 g of Na ₂ SO ₄ , and 5 g of CaCo ₃ were mixed and dispersed as a suspension dispersion, followed by acrylonitrile monomer, TGDA, toluene and A solution in which benzoyl peroxide (BPO) was mixed as an initiator was added and stirred at room temperature for 30 minutes. When the size of the monomer particles became uniform, the temperature inside the flask was increased to 70 ° C. to polymerize for 3 hours, and the temperature was further increased to 90 ° C. to further react for 1 hour to complete the polymerization. The total weight of the monomer and TGDA mixture was maintained at 40 g for 400 ml of suspension dispersion. The crosslinking degree of TGDA was 5%, and 5 mol of TGDA was added to 95 mol of monomers. Toluene was diluted to 120%, and the polymerized PAN resin matrix was washed several times with deionized water, filtered, and dried after soxhlet treatment with acetone as a solvent for 12 hours.

Step 2) Amidification of Crosslinked PAN Resin Matrix

300 mL of NH ₂ OH-methanol solution was added so that the ratio of -CN / NH ₂ OH was 1/2 to 10 g of PAN resin. NH ₂ OH- methanol solution is NH ₂ OH · H ⁺ Cl in 3ℓ of ^methanol-KOH was added to 230g, while it is gradually cooled below 10 ℃ then dissolving ^{_{285g NH 2 OH · H + Cl}} - and destroy the yeomsangtae The precipitated KCl salt was prepared by filtration. The resulting NH ₂ OH-methanol solution was used while preserving at 5 ° C. or lower. When the crosslinked PAN resin was reacted at 60 ° C. for 4 hours and amiddification was completed, it was washed several times with deionized water and then dried in a vacuum oven.

Step 3) Measurement of metal ion adsorption capacity

0.1 g of the chelating resin was added to a 20 ml vial, and 20 ml of a 100 ppm Cu ⁺² metal ion solution with the liquidity adjusted to pH 4 was added, followed by stirring with a shaker (3 cm oscillation left and right, frequency 120 times / min). After 1,2,3,4,5,6 and 24 hours of chelating resin immersion, the metal ion solution was collected and the concentration of metal ions remaining in the solution was measured by atomic absorption spectrophotometer. . In this way, the rate of metal ion adsorption recovery ratio (percent recovery ratio) was measured as the immersion time of the amidoxime-type chelate resin was as shown in Table 1 below.

EXAMPLES 2-7

Except that the degree of crosslinking and dilution in Example 1 was changed as shown in Table 1 below, the results in Table 1 were obtained.

[Examples 8-11]

In Example 1, the degree of crosslinking and dilution were changed as shown in Table 2 below, and NHOH · H was added to 3 L of water. Cl 285 g was dissolved first, then 160 g of NaOH was slowly added while cooling to 10 ° C. or lower. Cl Except for using NHOH aqueous solution prepared by breaking the salt state of the same as in Table 2 to obtain the results.

[Examples 12 and 13]

In Example 1, the degree of crosslinking and dilution were changed as shown in Table 3 below, and the Cu concentration of 200 ppm in the metal ion adsorption performance experiment Except that the ionic solution was used, the same results as in Table 3 were obtained.

[Examples 14 to 16]

In Example 8, the degree of crosslinking and dilution were changed as shown in Table 4 below, and the Cu concentration of 200 ppm in the metal ion adsorption capacity experiment. Except that the ionic solution was used, the same results as in Table 4 were obtained.

Claims (6)

Tetraethylene glycol diacrylate as a crosslinking agent is mixed with the acrylonitrile monomer, and a diluent is added thereto, followed by suspension polymerization to prepare a crosslinked polyacrylonitrile resin matrix having a crosslinking degree in a range of 5 to 20%. A method for producing an amidoxime chelate resin, wherein the polyacrylonitrile resin matrix is amidoximated with NH ₂ OH. The method for producing amidoxime chelate resin according to claim 1, wherein the diluent is toluene. The method for producing amidoxime chelate resin according to claim 1 or 2, wherein the diluent is used in a dilution range of 30 to 200% (volume ratio to the sum of the monomer and tetraethylene glycol diacrylate). The method of claim 1, wherein the amidoxification reaction is a reaction method for producing amidoxime chelate resin, characterized in that for 1 to 6 hours at a temperature of 50 ~ 90 ℃. The method according to claim 1, wherein the NH ₂ OH is used in an amount of 1 to 4 moles based on the number of moles of the acrylonitrile monomer constituting the polyacrylonitrile resin matrix. The method of claim 1, wherein the NH ₂ OH is used in the form of NH ₂ OH-methanol or NH ₂ OH in an amount of 100 to 500 ml based on 10 g of the polyacrylonitrile resin matrix. .