JPH08301930A - New chelate polymer and its production - Google Patents

Abstract

PURPOSE: To obtain a chelate polymer which can recover vanadium (V), molybdenum (VI), copper (II), iron (III) and valuable rare metals from a solution by selective adsorption. CONSTITUTION: A chelate polymer in which the main chain comprises a saturated aliphatic hydrocarbon, and at least part of the side chains are each represented by formula I or II (wherein R<1> is methyl, (un)substituted phenyl or benzyl; R<2> is hydrogen, methyl or phenyl; and R<3> is hydrogen, methyl or benzyl).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel chelate polymer suitable for selectively adsorbing and recovering valuable rare metals from a solution containing various metals, and a method for producing the same.

[0002]

2. Description of the Related Art In order to selectively adsorb and recover valuable rare metals from a solution containing various metals, it is important that they have a high adsorption capacity and adsorption rate and that they have excellent selective adsorptivity for valuable rare metals. is there. Generally, in an acid-type chelate polymer typified by iminodiacetic acid, acid dissociation occurs in the neutral to alkaline region, and in addition to adsorption of metal by a chelate bond, alkali metal and alkaline earth metal based on ionic bond Adsorption occurs. Also, copper, iron,
It adsorbs well to transition metals such as cobalt, nickel, manganese, and zinc, but its selective adsorption to each metal is poor.

An adsorbent having a Shiff base such as an amidoxime group has been developed as a chelate polymer having a high selective adsorption property to a transition metal, and uranium (VI), copper (I
I), iron (III), vanadium (V), molybdenum (VI)
However, the functional group is poor in stability and deteriorates during repeated adsorption and desorption. On the other hand, the following general formula (4)

[0004]

[Chemical 4]

It is known that the hydroxamic acid compound represented by (1) forms a chelate complex with many transition metal ions, and that the stability as a compound is known to be superior to that of the amidoxime compound. Utilizing this property, it is used for quantification, separation, recovery, etc. of transition metal ions. A large number of polymers introduced with a hydroxamic acid residue have been reported to date. A commercially available styrene-divinylbenzene copolymer resin (XAD4) is carboxylated, then treated with thionyl chloride to form an acid chloride, and the monohydroxamic acid resin obtained by reacting with hydroxylamine in an aqueous sodium carbonate solution is iron, aluminum, It is known to satisfactorily adsorb and collect copper ions [Richar
d G, PhillipsJames S. Fritz Anal.Chim.Acta 139,237
(1982)]. Further, a resin obtained by hydrolyzing an acrylonitrile-divinylbenzene copolymer with sulfuric acid in the presence of hydroxylamine can also collect a large number of ions such as iron, copper, cobalt, nickel, vanadium, uranium, mercury and lead ions. Possible [F.Verson H.Eccles Anal.Chim.Ac
ta82,369 (1976), 83,187 (1986)]. However, the reaction for introducing hydroxamic acid used in these methods does not always proceed in a good yield, and becomes a resin in which unreacted or carboxylic acid residues produced by hydrolysis coexist, and selectively transition metals. It becomes an interfering factor when adsorbing.

As another synthetic method, a malonic acid diester residue is introduced into a polystyrene resin and treated with hydroxylamine to facilitate introduction of a hydroxamic acid residue (JP-A-59-84907). Gazette),
Method for introducing a hydroxamic acid residue by reacting a crosslinked polyethyleneimine-based polymer compound with an allyl acid ester to obtain a polyethyleneimine derivative having a propionate ester residue in a side chain, and then reacting this with hydroxylamine (JP-A-62-48725) has been proposed. However, in the method via malonic acid diester, hydrolysis of the ester takes place in parallel to form a carboxylic acid residue. Further, when a polyethyleneimine derivative is used, polyethyleneimine itself has a strong complex forming ability, and thus the obtained resin has poor transition metal adsorption selectivity. As described above, in order to introduce a hydroxamic acid residue into a polymer, it is necessary to suppress the formation of a carboxylic acid residue that is a by-product and obtain a polymer having only hydroxamic acid as a functional group.

Further, the hydroxamic acid compound has two oxygen atoms as ligands, and usually two or three molecules are coordinated so as to surround the metal to form a complex. When a hydroxamic acid residue is introduced into a polymer, the movement of the molecule is sterically restricted, which hinders the formation of a stable 2- or 3-coordinated complex and needs improvement.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide a chelate polymer suitable for selectively adsorbing and recovering a transition metal contained in a solution, particularly a valuable rare metal.

[0009]

In view of the above-mentioned problems, the present inventor has noticed that the hydroxamic acid compound exists relatively stably with almost no adsorption of a metal derived from an ion exchange reaction. By introducing two molecules of the residue into one repeating unit of the polymer and making the polymer capable of capturing one metal ion by the one repeating unit, the steric complex formation inhibiting effect can be eliminated. ,
Furthermore, the present inventors have completed the present invention by finding out as a result of earnest research that the selective adsorption property to a specific valuable rare metal can be improved because the size of the adsorption site becomes constant. In addition, when introducing a hydroxamic acid residue into the polymer,
By converting the carboxylic acid in the iminodiacetic acid residue possessed by the polymer into an acid chloride using a phase transfer catalyst,
The present invention has been completed by finding that a by-product of a carboxylic acid residue can be suppressed and a hydroxamic acid residue can be introduced into a polymer in a high yield. That is, the present invention, the main chain is composed of a saturated aliphatic hydrocarbon, a part or all of the side chain is represented by the following formula (1) or
It is a chelate polymer characterized by being represented by (2).

[0010]

Embedded image

(Wherein R ¹ represents a methyl group, a phenyl group with or without a substituent, or a benzyl group, R ² represents hydrogen, a methyl group or a phenyl group, and R 2
³ represents hydrogen, a methyl group or a benzyl group. )

[0012]

[Chemical 6]

(In the formula, R ² represents hydrogen, a methyl group or a phenyl group, and R ³ represents a hydrogen, a methyl group or a benzyl group.) Further, the present invention has an iminodiacetic acid residue as a functional group. In the polymer, the carboxylic acid in the iminodiacetic acid residue is converted to an acid chloride in the presence of a phase transfer catalyst, and then reacted with hydroxylamine to convert the iminodiacetic acid residue into N, N-diacethydroxamic acid. A method for producing a chelate polymer, which is characterized by using a residue.

The present invention will be described in detail below. The chelate polymer of the present invention has a main chain of a saturated aliphatic hydrocarbon. Here, "the main chain is composed of a saturated aliphatic hydrocarbon" means that the main chain portion is a saturated aliphatic hydrocarbon, and the side chain may have any functional group.
For example, polystyrene having a phenyl group in the side chain and polyvinyl alcohol having a hydroxyl group in the side chain are polymers in which the main chain in the present invention is a saturated aliphatic hydrocarbon. Further, the chelate polymer of the present invention is a polymer having an N, N-diacethydroxamic acid residue represented by the following formula (1) or formula (2) in a part or all of its side chain. .

[0015]

[Chemical 7]

(Wherein R ¹ represents a methyl group, a phenyl group with or without a substituent, or a benzyl group, R ² represents hydrogen, a methyl group or a phenyl group, and R 2
³ represents hydrogen, a methyl group or a benzyl group. )

[0017]

Embedded image

(In the formula, R ² represents hydrogen, a methyl group or a phenyl group, and R ³ represents hydrogen, a methyl group or a benzyl group.) In the present invention, R ¹ in the formula (1) is particularly preferably A methyl group or a benzyl group is preferable, and a group represented by the following formula (3) is particularly preferable.

[0019]

[Chemical 9]

The chelate polymer of the present invention may be a polymer having a relatively low degree of polymerization called an oligomer, but a polymer having a high degree of polymerization is preferable in view of the usage as an adsorbent, and a polymer having a degree of crosslinking is preferable. Particularly preferred. In this case, the degree of crosslinking is preferably 20 to 30%. The chelate polymer of the present invention has 4 atoms of oxygen and 1 atom of nitrogen as a ligand. Therefore, it is possible to capture one metal with one repeating unit on the polymer, and therefore it is possible to eliminate the steric constraint that occurs when a hydroxamic acid residue is introduced into the polymer, and to stabilize the stability. It is possible to form various metal complexes.

Here, the coordination field in the present chelate polymer is shown in FIG. As shown in FIG. 1, the bond distance between the ligand and the metal in the coordination field is restricted, and the structure is restricted. Therefore, depending on the size of the coordinating metal, a stable metal complex can be obtained. Some of the elements are not capable of forming a metal, and the polymer is more excellent in selective adsorption to metal than the conventional hydroxamic acid polymer.

Hereinafter, one example of the method for producing the chelate polymer of the present invention will be described, but it goes without saying that the method for introducing the N, N-diacethydroxamic acid residue into the polymer is not limited to the following method. That is. For producing the chelate polymer of the present invention, a chelate polymer having an iminodiacetic acid residue as a functional group can be used as a raw material. The iminodiacetic acid residue has the following chemical formula (5)

[0023]

[Chemical 10]

Examples include those represented by: The chemical structure of the part other than the functional group in this precursor is preferably one that is stable to a strong acid such as thionyl chloride used in the reaction process and is not chemically changed, and its main chain is a saturated aliphatic hydrocarbon. Any material such as polystyrene and polyethylene can be freely selected, but polystyrene is preferable. Further, as the type of the cross-linking agent, any substance that is chemically stable to an acid can be used as well, and the physical properties of the polymer can be adjusted. The polymer compound having iminodiacetic acid as a functional group can be used in any shape such as bead shape, fiber shape, powder shape, and film shape, and can be shaped according to the purpose.

To produce the chelate polymer of the present invention,
First, the carboxylic acid in the iminodiacetic acid is converted into acid chloride. It is relatively easy to directly convert carboxylic acid to hydroxamic acid in low molecular weight compounds,
A water-insoluble polymer causes a marked decrease in reactivity. Therefore, it is necessary to increase the electrophilicity of carbonyl of carboxylic acid, and conversion to acid chloride is performed.

Thionyl chloride, phosphorus pentachloride, dichlorotriphenylphosphorane and the like can be used as reagents for acid chloride formation, but thionyl chloride having a low boiling point and easy to handle is preferable. Since thionyl chloride itself is a liquid as a reaction solvent, it can be used directly. Further, it is possible to freely select and use an organic solvent which does not directly react with carboxylic acid and thionyl chloride and can be mixed with thionyl chloride in an arbitrary ratio, but the hydrophilicity of the product It is preferable to use 1,2-dichloroethane, dichloromethane or the like, which has a high dielectric constant, in order to increase the temperature.

When the polymer is insoluble in the organic solvent used in the reaction, the acid chloride formation reaction does not proceed under normal conditions. It is known that the addition of a phase transfer catalyst to carboxylic acids, which have very low solubility in organic solvents in low molecular weight compounds, significantly improves the rate of acid chloride formation [KA Burdett Synthesis 441 (1991)],
In the present invention, it was found that this method is also effective in the reaction on the polymer, and it was possible for the first time to advance the reaction in a high yield by adding a catalytic amount of a phase transfer catalyst. Such phase transfer catalysts include alkylbenzyl 4 such as benzyltriethylammonium chloride.
Examples thereof include primary ammonium salts, and among them, benzyltriethylammonium chloride is preferably used.

The reaction temperature depends on the type of solvent used,
It is usually 60 to 100 ° C., and the reaction time is usually in the range of 5 to 20 hours, though it depends on the reaction temperature. Desirably, all operations are carried out in a stream of dry nitrogen, as the presence of water in the air causes hydrolysis to produce carboxylic acid by-products. The obtained polymer compound is washed with the organic solvent used as the reaction solvent and stored in the solvent at ice temperature.

Next, the thus obtained polymer compound having a residue converted to iminodiacetic acid chloride is reacted with hydroxylamine to convert it into a chelate polymer having an N, N-diacethydroxamic acid residue. To do. The synthesis conditions for the conversion may be based on conventional methods, but it is preferable to avoid contact with water as much as possible. Examples of hydroxylamine used in the method for producing the chelate polymer of the present invention include hydroxylamine hydrochloride, N-methylhydroxylamine hydrochloride, N-phenylhydroxylamine hydrochloride, O-methylhydroxylamine hydrochloride and O-benzylhydroxylamine. Hydrochloride, N, O-dimethylhydroxylamine hydrochloride and the like can be mentioned, with hydroxylamine hydrochloride being preferred.

When hydroxylamine hydrochloride is used, it is prepared by dissolving hydroxylamine hydrochloride in methanol or ethanol in advance, neutralizing it with the corresponding sodium alkoxide at ice temperature, and removing the formed sodium chloride precipitate by filtration. It is preferably used. Hydroxylamine is slowly added to an organic solvent in which a polymer compound converted into an acid chloride is suspended at an ice temperature and gradually heated to react. The reaction temperature is usually 40 to 80 ° C., and the reaction time is appropriately 1 to 3 days, depending on the temperature.
After the reaction, the resin is preferably thoroughly washed with water and then washed with methanol using a Soxhlet extractor for about 48 hours.

The chelate polymer having an N, N-diacethydroxamic acid residue as a functional group obtained as described above is a transition metal, particularly molybdenum (VI), iron (III), vanadium (V) and copper. It has an excellent adsorptivity for (II) and no adsorptivity for alkali metals such as sodium, potassium, magnesium and calcium, and alkaline earth metals. Among the transition metals, cobalt (II), nickel (II), manganese (II), zinc (I
It is a highly selective adsorbent that hardly adsorbs ions such as I) and these metals can be easily separated and recovered by changing the pH. It is a very useful chelate polymer as an adsorbent for recovery.

[0032]

The present invention will be described in more detail below with reference to examples, but these examples do not limit the scope of the present invention. (Example 1) Commercially available iminodiacetic acid type chelate resin DIAION CR10 <Na type> (manufactured by Mitsubishi Kasei Co., degree of crosslinking: about 25%)
Is treated with 1N hydrochloric acid to produce an acid type (Diaion CR10 <H type>)
After that, washing with water was repeated until precipitation with silver nitrate stopped, and this was vacuum dried at 40 ° C. for 48 hours.

This dried DIAION CR10 <H type>
5 g, 1,2-dichloroethane (20 cm ³⁾ and benzyltriethylammonium chloride (100 mg) were added to a 50 cm ^{3 three-} necked flask and left for 30 minutes. This was ice-cooled, thionyl chloride (5 cm ³⁾ was slowly added, and the mixture was allowed to stand for another 30 minutes, then at 90 ° C, 8
Heated to reflux for hours. The reaction product was filtered through a glass filter and washed with 1,2-dichloroethane. This acid chloride converted CR10 is hereinafter referred to as CR10COCl. CR10COCl was transferred to a 200 cm ^{3 three-} necked flask containing 50 cm ³ of 1,2-dichloroethane and cooled with ice.

Separately, 6.95 g of hydroxylamine hydrochloride was stirred and suspended in 100 cm ³ of ethanol and kept under ice temperature.
A 20% sodium ethoxide ethanol solution was added in a neutralized amount, the mixture was stirred for 30 minutes and then filtered, and the filtrate was concentrated to about 50 cm ³ using a rotary evaporator. This hydroxylamine ethanol solution was slowly added dropwise to the above three-necked flask containing CR10COCl, and allowed to stand for 30 minutes, then at 70 ° C.
And refluxed for 48 hours.

After completion of the reaction, the produced N, N-diacethydroxamic acid type chelate resin was collected by filtration with a glass filter,
Methanol and water were washed in that order, and further washed with methanol using a Soxhlet extractor for 48 hours. This CR10 reformer
N, N-Diacetohydroxamic acid type chelate resin
Expressed as 10HX. On the other hand, as the iminodiacetic acid type chelate fiber, polystyrene-based IDA-Na (manufactured by Toray Industries) cut fiber is used as the starting material, and by the same operation as Diaion CR10, conditioning, synthesis and washing are performed, and N, N-diacethydroxam An acid type chelate fiber was obtained. This N, N-
The diacetohydroxamic acid type chelate fiber is referred to as IDAHX-
Expressed as F.

(Example 2) CR10COCl obtained in Example 1 and
CR10HX and CR10 used as the raw materials for each of them are reduced under reduced pressure.
It was dried at ° C to obtain a powder. Using this powder as a sample, it was mixed with potassium bromide in an agate mortar and the infrared absorption spectrum was observed using the diffuse reflection method. The results are shown in Figure 2.

As is clear from FIG. 2, in CR10, the absorption of C═O stretching vibration peculiar to dicarboxylic acid is 1730 cm ⁻¹ and 1630.
Although it is split into cm ⁻¹ , two absorptions in CR10COCl become one and shift to the higher wave number side due to the effect of chlorine substitution (1749 cm ⁻¹ ). Further absorption around 3230Cm ^-1 attributed to absorption and NH stretching vibration attributed to C = O stretching vibration in the vicinity of ^-1 characteristic 1670cm appeared in the hydroxamic acid CR10HX, N, N- di acetohydroxamic acid residue It was shown that the group was introduced.

Example 3 Measurement of Functional Group Conversion Rate by Elemental Analysis CR10HX synthesized in Example 1 and used as a starting material
CR10 was crushed in an agate mortar and dried in vacuum, and the C, H, and N element contents in the polymer were determined using a CHN element analyzer. The conversion rate from carboxylic acid to hydroxamic acid was calculated from the C / N ratio in the polymer. The results are shown in Table 1.

[0039]

[Table 1]

The IDAHX-F was also examined in the same manner, and as a result, the conversion rate was 17.6%. When only the reaction of -COOH → -CONHOH is occurring, the C content should not change and only the N, H content should increase, but the result is that the C, N content increases and the ester reaction as a side reaction. Is expected to be generated.

(Example 4) of a polymer treated with NaOH
IR spectrum CR10HX obtained in Example 1, CR10 used as a raw material thereof, and a chelate resin CR having an amidoxime group as a comparative resin
50 (manufactured by Mitsubishi Kasei Co., Ltd.) was immersed in 1N NaOH for 24 hours, and the presence or absence of change in the structure of the chelate resin before and after was confirmed by IR spectrum. The results for CR10 are shown in FIG. 3, the results for CR50 are shown in FIG. 4, and the results for CR10HX are shown in FIG.

As is clear from FIG. 3, in CR10, NaOH
The absorption derived from the dicarboxylic acid at 1735 and 1683 cm ^-1 observed before the treatment became one absorption at 1638 cm ^-1 by the NaOH treatment, and it was changed to the sodium salt of carboxylic acid because it was shifted to the low wave number side. I understand. Further, as is clear from FIG. 4, in CR50, the absorption at 1653 cm ⁻¹ derived from the C═N bond was split into two absorptions at 1655 and 1560 cm ⁻¹ by the NaOH treatment, resulting in a change in chemical structure. On the other hand, as is clear from FIG. 5, no structural change was observed in CR10HX before and after the NaOH treatment, and it was found that sodium is less likely to be adsorbed by ion exchange and that the resin is chemically stable.

Example 5 The sample obtained by treating CR10HX obtained in Example 1 with 1N hydrochloric acid, washing with water, and suction filtration was subjected to an adsorption test. In order to evaluate the selective adsorption properties of CR10HX resin for metals, magnesium (II), calcium (II), vanadium (V), manganese (II), iron (III), cobalt (II), nickel (II), copper ( II), zinc (II), and molybdenum (VI) each containing 0.2 mM of McIlvaine buffer (0.2 M disodium hydrogen phosphate-0.1 M citric acid), pH 2, 4,
Adsorption solutions of 6 and 8 were prepared. Adsorption test is CR10HX 100mg
(Dry weight) 100 ml of the adsorbent was added, and the mixture was shaken at 100 rpm at 25 ° C. for 5 days, and the metal concentration in the solution before and after the adsorption was quantified by ICP (Induced Coupling Plasma) luminescence method. . FIG. 6 shows the results. The ordinate represents the distribution coefficient Kd as a scale showing the metal adsorption capacity of the resin, and was calculated by the following equation.

[0044]

[Equation 1]

From the results of this experiment, the following was clarified. CR10HX does not adsorb alkaline earth metals such as magnesium and calcium contained in the solution, and exhibits almost no adsorptivity for transition metals such as cobalt and nickel. On the other hand, for molybdenum and iron
It exhibits strong adsorptivity in the weakly acidic region around pH 2, and does not show any adsorptivity for molybdenum at around pH 8. In addition, vanadium and copper have a characteristic of exhibiting strong adsorption ability in a weak alkaline region around pH 8. By applying this property, vanadium and molybdenum contained in the solution can be separated and recovered.

(Example 6) The IDAHX-F obtained in Example 1 was treated with 1N.
The sample treated with hydrochloric acid, washed with water, and suction filtered was subjected to an adsorption test. In order to investigate the optimum pH of adsorption of vanadium and molybdenum on IDAHX-F, an aqueous solution containing vanadium (V) and molybdenum (VI) 0.2 mM at pH 0.7 to 14 and 0.5 M sodium chloride solution were prepared. Hydrochloric acid or sodium hydroxide was used for pH adjustment, and the pH of the adsorbed liquid and the vanadium and molybdenum concentrations before and after the adsorption test were measured. The adsorption test was carried out by adding 100 ml of the adsorbent to 50 mg (dry weight) of IDAHX-F and shaking at 100 rpm for 24 hours at 25 ° C. Similar to Example 3, the metal adsorption capacity of the chelate fiber was expressed as a distribution coefficient (Kd). FIG. 7 shows the results. The pH of the solution did not change before and after adsorption.

From the results of this experiment, the following was clarified. The optimum pH of IDAHX-F for adsorption of vanadium and molybdenum in dilute solution is 4 ~ for vanadium.
The pH for molybdenum 9 and molybdenum is 3 to 5, but the adsorption capacity is exhibited even in a region outside this pH region. Especially for molybdenum, even in a strongly acidic region such as 3N hydrochloric acid solution, Kd
Is around 100, and does not stop adsorbing at all. Also, due to the difference between the aqueous solution and the 0.5M sodium chloride solution,
Adsorption amount of vanadium and molybdenum changes, but optimum pH
Does not change.

(Example 7) CR10HX and ID obtained in Example 1
AHX-F was subjected to adsorption test. To investigate the effect of coexisting ions on the adsorption of vanadium on CR10HX and IDAHX-F.
An adsorbent having a pH of 8 containing 2 mM vanadium and 0, 0.5, 1.0, 5.0 M sodium chloride as coexisting ions was prepared. Sodium hydroxide was used for pH adjustment. The adsorption test was carried out by adding 100 ml of the adsorbing solution to 100 mg (dry weight) of CR10HX and IDAHX-F and shaking at 25 ° C. and 100 rpm. Adsorption time is 5 days for CR10HX and 24 for IDAHX-F
It was time. The results are shown in Fig. 8.

From the results of this experiment, both CR10HX and IDAHX-F were affected by the coexisting sodium chloride in the solution, the concentration of sodium chloride was increased, and the adsorption of vanadium was inhibited. In particular, the degree of inhibition of IDAHX-F was It turned out to be great. As described above, as shown in Examples 5, 6 and 7, the adsorption characteristics of the polymer of the present invention are changed by the influence of coexisting ions contained in the solution. It is possible to separate and collect the metal.

[0050]

According to the present invention, vanadium (V), molybdenum (VI), copper (II), iron (III) contained in the solution
Alternatively, a chelate polymer capable of selectively adsorbing and recovering valuable rare metals can be obtained.

[Brief description of drawings]

FIG. 1 is a diagram showing a coordination field in a chelate polymer of the present invention.

FIG. 2 is a chart showing IR spectra of CR10, CR10COCl and CR10HX.

FIG. 3 is a chart showing IR spectra of CR10 and NaOH-treated CR10.

FIG. 4 is a chart showing IR spectra of CR50 and CR50 treated with NaOH.

FIG. 5 is a chart showing IR spectra of CR10HX and CR10HX treated with NaOH.

FIG. 6 is a graph showing the relationship between pH and metal adsorption capacity of CR10HX.

FIG. 7 is a graph showing the relationship between pH and V (V), Mo (VI) adsorption capacity of IDAHX-F (in an aqueous solution and a 0.5 M NaCl solution).

FIG. 8 is a graph showing the relationship between NaCl concentration and V (V) adsorption capacity of CR10HX and IDAHX-F.

Claims (7)

[Claims] 1. A chelate polymer having a main chain of a saturated aliphatic hydrocarbon, and a part or all of a side chain thereof is represented by the following formula (1) or (2). Embedded image (In the formula, R ¹ represents a methyl group, a phenyl group with or without a substituent, or a benzyl group, R ² represents hydrogen, a methyl group or a phenyl group, and R ³ represents hydrogen, a methyl group or Represents a benzyl group.) (In the formula, R ² represents hydrogen, a methyl group or a phenyl group, and R ³ represents hydrogen, a methyl group or a benzyl group.) 2. The chelate polymer according to claim 1, wherein the side chain is represented by the following formula (3). Embedded image 3. The chelate polymer according to claim 1, wherein the main chain has a crosslink. 4. A polymer having an iminodiacetic acid residue as a functional group, wherein the carboxylic acid in the iminodiacetic acid residue is converted into an acid chloride in the presence of a phase transfer catalyst, and then reacted with hydroxylamine, A method for producing a chelate polymer, wherein the iminodiacetic acid residue is an N, N-diacethydroxamic acid residue. 5. The method for producing a chelate polymer according to claim 4, wherein the phase transfer catalyst is benzyltriethylammonium chloride. 6. The method for producing a chelate polymer according to claim 4, wherein the hydroxylamine is hydroxylamine hydrochloride. 7. The chelate polymer according to claim 4, wherein the polymer having an iminodiacetic acid residue as a functional group is a polymer having an iminodiacetic acid residue as a functional group in a phenyl group of polystyrene. Production method.