JPS6121735A - Phenolic chelating ion exchange resin - Google Patents

Abstract

PURPOSE:To enhance the selective adsorbing catacity to a ferric ion, by constituting a phenolic chelating ion exchange resin by introducing a specific chelate group represented by general formula into the phenol nuclei of phenols. CONSTITUTION:A phenol compound represented by formula (wherein M is an alkali metal or hydrogen and R1 and R2 are hydrogen and an alkyl group), phenols and aldehydes are subjected to condensation reaction in such a state that a preparation mol ratio is adjusted corresponding to a purpose to prepare a phenolic chelating ion exchange resin. As the phenol compound represented by the formula, one having M is the formula substituted with an alkali metal has good dissolvability and easy reactivity. In order to obtain the resin having as uniform a composition as possible in the aforementioned condensation reaction, reaction temp. is controlled to 20-90 deg.C and it is desirable to gradually raise temp.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel phenolic chelating ion exchange resin.

Dowex A-1 (manufactured by Dow Chemical Company), Diaion CR-10゜20 (manufactured by Mitsubishi Kasei Corporation) and Unicelesoc tlR-10,203 are conventionally used as chelating ion exchange resins useful for adsorption removal and recovery of heavy metal ions.
0 (manufactured by Unitika) and others are commercially available and in practical use. Generally, these chelating ion exchange resins are used for adsorption removal and recovery of heavy metals such as copper, nickel, and zinc in aqueous solutions, and their effectiveness has been recognized. Selective adsorption removal of heavy metal ions, especially ferric ions, and low p
It has also been recognized that there are problems with the selective trapping performance of heavy metal ions in l+ aqueous solutions.

However, there are various types of aqueous solutions containing heavy metals, and only ferric ions in aqueous solutions containing a plurality of heavy metals are selectively adsorbed and removed.

In some applications, if the heavy metals contained can be recovered in parts, the treated aqueous solution can be reused as is.

Among the conventionally known chelating ion exchange resins, there is none that exhibits particularly excellent selective trapping ability for ferric ions, and none that exhibits excellent selective adsorption ability in the low pH w4 range. For this reason, research is being continued from various angles on the types of functional groups, etc., in part for the purpose of capturing special heavy metals, but this has not yet been put to practical use.

In view of the current situation, the present inventors have attempted to produce a chelating ion exchange resin that exhibits particularly excellent selective adsorption ability for ferric ions using chemically stable and relatively inexpensive compounds. As a result of intensive research, we found that chelating ion exchange resin, in which a phenol compound with two iminodiacetic acid groups introduced into the side chain of the phenol-aldehyde resin matrix, is an excellent choice for ferric ions in the low pH region. It was discovered that the present invention has adsorption ability.

That is, the present invention provides a phenolic chelating ion exchange resin in which a chelate group is introduced into the phenol nucleus of a phenol, in which the chelate group has the general formula (where 1M represents an alkali metal or hydrogen, and R1R2 represents hydrogen or an alkyl group). This is a phenol-based chelating ion exchange resin characterized by being a phenol compound shown below.

Examples of the phenolic compound represented by the general formula according to the present invention include (1-oxyphenylene-2,6)-bis-methyliminodiacetic acid, and such phenolic compounds include iminodiacetic acid, phenol, and formalin.
1v, Chim, ^cta, 35.1785 (1952
) is synthesized by the method described in . In addition, iminodiacetic acid is synthesized from inexpensive raw materials such as ammonia, hydrogen cyanide, and polymerine, and is an industrially produced low-molecular-weight compound called Kir-7.
Like the chelating agents ethylenediaminetetraacetic acid and nitrotriacetic acid, it has a 1^-CH2COOH4 group, so it has much better chemical stability than other chelating agents.

The chelating ion exchange resin of the present invention is, for example, (I-
Fe with phenolic compounds such as oxyphenylene-2,6)-bis-methyliminodiacetic acid.

It is produced by adjusting the mole ratio of somochi (rice cake) to be prepared according to the purpose, and converting the nols and aldehydes into a resin through a condensation reaction.

Among general phenolic resins, resol resins that harden only by heat treatment, and novolac resins that require the addition of aldehydes, etc., are well known. and phenols (hereinafter abbreviated as F/P)
Moreover, resol type or novolac type resins can be produced by the curvature of . ' In other words, in order to obtain a resol-type phenolic resin that cures only by heat treatment, the F/P should be in the range of 1.1 to 1.5, and a novolac-type phenolic chelating ion exchange resin that requires crosslinking treatment other than heat treatment. In this case, it is desirable to set F/P to 0.7 to 1.1. Therefore, P/P under general phenolic resin production conditions and F/P above have the same meaning.

When producing the chelating ion exchange resin of the present invention from phenols, aldehydes and (1-oxyphenylene-2,6)-bis-methyliminodiacetic acid, (1-oxyphenylene-2,6)'-bis-methyliminodiacetic acid It goes without saying that an equimolar amount of aldehyde must be used in excess as acetic acid.

To produce the chelating ion exchange resin of the present invention from phenols/aldehydes and (1-oxyphenylene-2,6)-bis-methyliminodiacetic acid, 1 For example,
Phenols and aldehydes or aldehydes may be added to perform a condensation reaction. In the condensation reaction, the reaction temperature is 20 to 90℃ in order to obtain a resin with as uniform a composition as possible.
It is desirable to control the temperature at ℃ and gradually increase the temperature. Finally, the temperature was kept at 90-111"C and the reaction proceeded under reflux.
Once the desired condensation stage is reached, the resin composition can be dehydrated by heating under reduced pressure or normal pressure to obtain a highly active resin composition. At this time, if necessary, fresh water can be added to wash the resin composition.

When producing the chelating ion exchange resin of the present invention, phenolic compounds in which M in the general formula is substituted with an alkali metal have good solubility and are easy to react with, for example (1-oxyphenylene-2,6 )-bis-methyliminodiacetic acid is reacted with an alkali metal such as sodium hydroxide to replace the terminal end of the acetic acid group with the alkali metal, and then the polycondensation reaction is preferably carried out. In addition, the mixing amount of the phenol compound and phenols affects the chelating performance and the durability of the resin, and if the molar ratio of the phenol compound to the total phenol is less than 0.1, the chelate
・Performance will be insufficient, and if it exceeds 0.5, three-dimensional crosslinking will not progress sufficiently and it will be difficult to obtain a resin that can withstand practical use, so it is recommended to mix so that the molar ratio is within the range of 0.1 to 0.5. desirable. Examples of phenols used in the present invention include compounds with phenolic hydroxyl groups such as phenol, alkyl-substituted phenols such as cresol and xylenol, polyhydric phenols such as resorcinol and catechol, and α-naphthol; Alternatively, they can be used in combination.

Examples of aldehydes include aldehyde derivatives such as formaldehyde, paraformaldehyde, and hexamethylenetetramine, aliphatic aldehydes such as acetaldehyde and propionaldehyde, aromatic aldehydes such as benzaldehyde, and heterocyclic aldehydes such as furfural. These may be used alone or in combination.

9 As a reaction accelerator when carrying out a condensation reaction.

Mineral acids such as hydrochloric acid and sulfuric acid, and organic acids such as formic acid and oxalic acid.

Aromatic sulfonic acids such as Hensensulfonic acid, or metal hydroxides such as sodium hydroxide, potassium hydroxide,
Amines such as ammonia, trimethylamine, and triethylamine, and nitrogen-containing basic compounds such as pyridine can be used alone or in combination.

The novolac-based chelating ion exchange resin of the present invention is
Utilizing its thermoplasticity, it can be processed into various shapes and then cured by a crosslinking reaction, so it has a wide range of uses.

In that case, if the crosslinking reaction is carried out by immersion in an aqueous aldehyde solution, it is preferable to add an acid such as hydrochloric acid or oxalic acid as a catalyst or to heat it to increase the crosslinking rate.

Also.

Pulverized novolak chelating ion exchange resin.

It can also be made into a molding material by mixing a crosslinking agent such as hexamine, and crosslinked by heating.

On the other hand, the resol type chelating ion exchange resin of the present invention can be easily cured by dissolving it in water or an organic solvent, processing it into various shapes, and then heating it. Of course, it is possible to simultaneously perform granulation and crosslinking in an insoluble solvent to form a small spherical chelating ion exchange resin.

It can be used in exactly the same manner as conventionally known small spherical chelating ion exchange resins. In particular, the chelating ion exchange resin of the present invention is characterized by its excellent processability during production.

The selective adsorption of heavy metal ions of the phenolic chelating ion exchange resin of the present invention varies depending on the PLL of the mold metal ion aqueous solution, temperature, type and concentration of coexisting ions, etc., but generally ferric, copper, nickel, and aluminum. 〉Zinc〉Cobalt〉Manganese〉Calcium〉Magnesium〉Barium) Sodium has the highest selectivity for ferric iron, and in particular, its adsorption performance for ferric ions in low-pi aqueous solutions is very high compared to other metals. good. For example, by adjusting the pH and temperature of the aqueous solution, the chelating ion exchange resin of the present invention can reduce the ion concentration of calcium and zinc' when treating an aqueous solution containing the same concentrations of three metal ions: calcium, zinc, and ferric iron. It exhibits such good selectivity for ferric ions that it selectively adsorbs only ferric ions with almost no change. Furthermore, the same results in heavy metal ion adsorption ability and selectivity can be obtained with either novolac type or resol type phenolic chelating ion exchange resins.

The phenol-based chelating ion exchange resin of the present invention has different adsorption ability for heavy metal ions depending on its manufacturing conditions.
-0.5 to 1 per equivalent of bis-methyliminodiacetic acid group
．． Zero equivalents of heavy metal ions form a chelate.

In an aqueous solution containing ferric ions, iron ions form hydroxides and some of them dissolve.

When the pH of the aqueous solution becomes 3 or less, most of the iron is ionized. Therefore, when adsorbing and removing ferric ions, the pH
It is desirable to treat an acidic aqueous solution with a pH of 3 or less with a chelating ion exchange resin, but the heavy metal adsorption capacity of conventionally known chelating ion exchange resins decreases in strong acidity of pH 3 or less, especially pH 2 or less. Do2-10. Preferably, it is used in the range of 3 to 9. However, the chelating ion exchange resin of the present invention exhibits a strong selective adsorption ability for ferric ions even under strong acidification of pH 3 or lower, especially pH 2 or lower, so that ferric ions in a strongly acidic aqueous solution can be adsorbed and removed. Of course, an aqueous solution containing multiple heavy metals is
By treating it as a strong acid of H2 or less, only ferric ions can be selectively adsorbed.

Heavy metal ions are adsorbed onto the chelating ion exchange resin of the present invention, and when the adsorption capacity becomes saturated, the double metal ions can be easily desorbed from the resin by treatment with an aqueous mineral acid solution such as hydrochloric acid or sulfuric acid. and elutes in mineral acid aqueous solution. The resin from which the heavy metal ions have been eluted can be used again as is, but it is preferably treated with an alkaline aqueous solution such as sodium hydroxide or potassium hydroxide, or washed with water and reused. There is hardly any decrease in heavy metal ion adsorption capacity or selectivity due to this reuse.

The phenolic chelating ion exchange resin of the present invention can be obtained by a simple manufacturing method as detailed above, and exhibits special heavy metal scavenging effects, particularly excellent ferric iron scavenging effects. Moreover, it is practical because it can be recycled and reused any number of times by simple acid treatment, and it is a new ion exchange resin that can be used for new purposes different from conventional phenolic chelating ion exchange resins.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Parts and percentages in the examples represent weight.

Example 1 227.3 parts of 22% sodium hydroxide was slowly added to 96 parts of (1-oxyphenylene-2゜6)-bis-methyliminodiacetic acid while cooling to form a homogeneous aqueous solution, and 20.3 parts of 37χ formalin was added. The reaction was carried out for 3 hours while maintaining the temperature at 65 to 70°C. After the reaction was completed, the reaction solution was cooled and 23.5 parts of phenol was added while stirring, and the reaction was continued at 85 to 90° C. for 4 hours. The obtained reaction solution was cooled, and 37
Add 80.5 parts of % formalin.

Suspension polycondensation was carried out to obtain 175 parts of a cured resin.

After washing this resin with water, it was neutralized with mineral acid to obtain an orange-yellow resin.

This resin was poured into a ferric aqueous solution previously adjusted to pH 2.0, shaken, and its adsorption capacity was measured. As a result, the adsorption capacity was 1.5 milliequivalents/g resin. Further, after adsorption, when this resin was subjected to desorption of ferric iron using mineral acid, ferric ions were easily eluted, and there was almost no decrease in the adsorption ability. Moreover, this adsorption capacity was almost not different from that measured with a ferric aqueous solution at pH 4.0.

Example 2 227.3 parts of 22% sodium hydroxide was slowly added to 96 parts of (1-oxyphenylene-2,6)-bis-methyliminodiacetic acid while cooling to form a homogeneous aqueous solution.

Next, add 20.3 parts of 37% formalin and lower the temperature to 65%.
The temperature was maintained at ~70°C and three poetic reactions were performed. After the reaction was completed, 27.5 parts of resorcinol was added to the reaction solution while cooling and stirring, and the reaction was continued at 25 to 50° C. for 2 hours. The resulting reaction solution was cooled, 80.5 parts of 37% Polmarine was added, and suspension polycondensation was carried out to obtain 160 parts of cured resin.

This resin was treated in the same manner as in Example 1, and the adsorption performance of the resin obtained was measured, and the result was 1.2 milliequivalent of 7 g resin.

This resin is packed into a column to extract calcium ions.

When an aqueous solution of pH 1.5 containing equal amounts of zinc ions and ferric ions was treated, most of the ferric ions were adsorbed, but most of the calcium ions and zinc ions leaked out.

Example 3 96 parts of (1-oxyphenylene-2,6)-bis-methyliminodiacetic acid, 227.3 parts of 22x hydric soda and 37 parts of
Add 20.3 parts of % formalin and reduce the temperature to 65-70”
The reaction was continued for 3 hours while maintaining the temperature at c. Furthermore, phenol 23.
5 parts were added and the reaction was continued at 85-90°C for 4 hours.

When 80.5 parts of 37% formalin was added to the resulting reaction solution and suspension polycondensation was carried out, 170 parts of cured resin was obtained.

This resin was treated in the same manner as in Example 1, and the adsorption performance of the resin was measured, and the result was 1.7 milliequivalents/g resin.

This resin was packed into a column and the pH was 1.5 to 500 pp'm each containing aluminum ions and ferric ions.
When an aqueous solution of was treated, most of the ferric ions were adsorbed, but most of the aluminum ions leaked out.

Example 4 96 parts of (1-oxyphenylene-2,6)-bis-methyliminodiacetic acid, 227.3 parts of 22% sodium hydroxide and 37
Add 20.3 parts of formalin and bring the temperature to 65-70℃
The reaction was carried out for 3 hours while maintaining the temperature. Furthermore, 15 parts of resorcin was added and the reaction was continued at 25 to 50°C for 2 hours, and after one reaction was completed, the reaction mixture was neutralized with hydrochloric acid.

It was heated and dehydrated at 100 to 110°C. The resulting resin was crushed and immersed in a 1:1 mixture of 35% hydrochloric acid and 37% formalin overnight, followed by heating and mixing at 90°C for 2 hours, and then heating the resin at 120°C for 2 hours.

This resin was treated in the same manner as in Example 1, and the adsorption capacity of the resin was measured, and it was found to be 1.1 milliequivalent of 7 g resin.

Example 5 227.3 parts of 22% sodium hydroxide was slowly added to 96 parts of (1-oxyphenylene-2,6)-bis-methyliminodiacetic acid while cooling to form a homogeneous aqueous solution.
Add 16.4 parts of para-formaldehyde and bring the temperature to 6.
The reaction was kept at 5-70°C for 3 hours. After the reaction was completed, the reaction solution was cooled, 47 parts of phenol was added while stirring, and the reaction was continued at 85 to 90° C. for 4 hours. 92% paraformaldehyde 7!1. ．． When 2 parts were added and suspension polycondensation was carried out, 250 parts of cured resin was obtained.

This resin was treated in the same manner as in Example 1, and the adsorption capacity of the resin was measured, and the result was 0.8 meq/g resin.

Example 6 96 parts of (1-oxyphenylene-2,6)-bis-methyliminodiacetic acid, 25 parts of sulfuric acid and 20 parts of 37% Polmarin.
3 parts were added and the reaction was continued for 5 hours while keeping the temperature at 65-70°C. Furthermore, 23.5 parts of phenol was added, and 85~
The reaction was continued at 90°C for 4 hours, and the resulting reaction solution contained 37%
When 80.5 parts of formalin was added and suspension polycondensation was carried out, 150 parts of hardened resin was obtained.

This was treated in the same manner as in Example 1, and the adsorption performance of the resulting resin was measured. As a result, the adsorption capacity was 1.3 milliequivalents/g resin.

Example 7 227.3 parts of 22% sodium hydroxide was slowly added to 96 parts of (l-oxyphenylene-2,6)-bis-methyliminodiacetic acid while cooling, and the mixture was first mixed with 20.3 parts of 37% formalin.
The reaction was carried out by stirring for 3 hours while maintaining the temperature at 65 to 70°C. Cool after the reaction is complete.

While stirring, add 27 parts of m-cresol and raise the temperature to 85.
The reaction was continued for an additional 5 hours at ~90°C.

After the reaction was completed, 80.5 parts of 37% formalin was added,
Stirring was performed at room temperature. Using the obtained reaction solution.

Suspension polycondensation yielded 155 parts of resin.

This was treated in the same manner as in Example 1, and as a result, the adsorption performance of the resin was 1.25 milliequivalents/g resin.

Example 8 The orange-yellow resin obtained in Example 1 was pre-treated with pt+
The adsorption capacity was measured by pouring it into a ferric aqueous solution adjusted to 2.0 and shaking, and the adsorption capacity was found to be 1.6 milliequivalents of 7g resin.

In addition, this resin is packed into a column to create a pH 1 solution containing equal amounts of magnesium ions, nickel ions, and cupric ions.
, 5 was treated, most of the cupric ions were adsorbed, but most of the magnesium ions and nickel ions leaked out.

Comparative Example I 26.6 parts of iminodiacetic acid, 18.8 parts of phenol, 37
% formalin and 4.7 parts of water at 70°C.
The mixture was stirred for 2 hours. As the reaction progressed, the system became non-uniform, and a white precipitate was formed at the end of one reaction.

After the reaction was completed, this white precipitate was collected, washed with water, and dried to obtain 43 parts of a reaction intermediate into which iminodiacetic acid groups were introduced.

The reaction intermediate thus obtained was subjected to elemental analysis. The results are shown in Table 1.

Note that the theoretical value is the value of hydroxybenzyliminodiacetic acid CI+ H+ :+ Os N, which is a compound when one iminodiacetic acid is included in the phenol nucleus.

Table 1 From the results in Table 1, the experimental values and the theoretical values agree well, and it is clear that the number of iminodiacetic acids introduced into the phenol nucleus is one (two iminodiacetic acids are introduced into the phenol nucleus). The theoretical value of N is 7.29%, which does not match the experimental results). .

Further, 2.39 g of the reaction intermediate was dissolved in 100 g of water.

0.0% under stirring. I N -NaOH (f=0.998
) is added dropwise until the inflection point (pH 5,
0), the 0, I N, -Na011 required to (
f=0.998) to determine the titration volume (number of ml).

The results are shown in Table 2. The theoretical value is this inflection point (
Since the amount of NaOH required to reach pH 5.0 is equimolar to that of iminodiacetic acid, the amount of NaOH consumed by the compound when one iminodiacetic acid is introduced into the phenol nucleus is 0,1N-
The amount of NaOH (f=0.998).

From the results in Table 2, the experimental values and theoretical values are in good agreement (
If two iminodiacetic acids are introduced into the phenol nucleus, 124.2 ml of 0. I N -Na0II will be consumed). ' Table 2 Next, 41.7 parts of 35% hydrochloric acid was added to the reaction intermediate obtained above, and while stirring, 81.0 parts of 37% formalin, 28.8 parts of phenol, and 4.7 parts of water were added at 50'c. After heating and stirring for 1 hour, the mixture was cooled to room temperature.

Carbon tetrachloride, monochlorohensen mixed medium and the above resin liquid to capacity II! , and stir while rotating for 120 minutes.
Suspension polycondensation was continued for 3 hours while removing water at °C to obtain a resin.

The adsorption capacity of this resin was measured in the same manner as in Example (1), and it was found to be 0.30 milliequivalent/g resin.

Comparative Example 2 13.5 parts of hydrocyanic acid was collected into an injection tube, and 3a, 5iap
Place 37% formalin in a three-way flask and heat at 0-5°C.
6N while cooling.
Sulfuric acid was added to bring the pH to 1. After keeping the temperature at 0 to 5°C for a while, this mixture was gradually added to an aqueous solution of 4.3 parts dissolved in 120 parts of aqueous ammonia in another three-bottle flask with stirring, and the reaction was continued for 3 hours. 37% of the second part
After adding formalin, the reaction was further carried out for 0.5 to 1 hour. The temperature was lowered to room temperature, 47 parts of phenol and 20 parts of 37% formalin were added, and the mixture was gradually heated to 70° C. with stirring to perform a Manninh reaction for 3 hours. After the Mannich reaction was completed, the temperature was lowered to below 50"C, and an aqueous solution of 20 parts of caustic soda dissolved in 20 parts of water was gradually added.
The mixture was heated and stirred at 00°C until the generation of ammonia stopped. The temperature of the reaction mixture was cooled to 20° C. and hydrochloric acid was gradually added to bring the temperature to below p)II, and a white precipitate was deposited.

This white precipitate was collected, washed with water and dried to obtain 47.8 parts of a reaction intermediate.

The reaction intermediate thus obtained was subjected to elemental analysis. The results are shown in Table 3. As in Comparative Example 1, the experimental values and theoretical values are in good agreement, and it is clear that in Comparative Example 2 as well, the number of iminodiacetic acids introduced into the phenol nucleus is one.

Table 3 Also, in the same manner as in Comparative Example 1, 2.39 g of the reaction intermediate obtained above was dissolved in 100 g of water, and 0.0 g of the reaction intermediate obtained above was dissolved in 100 g of water with stirring.
The 0, l required to reach the inflection point (pH 5,0) where the pH suddenly rises after dropping lN-NaOH (f = 0.998)
The titration volume (number of ml) of N-NaOH was determined. The results are shown in Table 4.

Table 4 As is clear from the results, almost the same results as Comparative Example 1 were obtained, and the reaction intermediate obtained in Comparative Example 2 was
It has the same structure as the reaction intermediate obtained in , and the number of iminodiacetic acids introduced into the phenol nucleus is one.

Next, hydrochloric acid was added to the reaction intermediate obtained above, and further 37
Add 40.5 parts of % formalin and raise the temperature to 90-95°C.
The reaction was continued for 3 hours. Next, after neutralizing the hydrochloric acid and washing with water, the reaction system was reduced in pressure and dehydrated to obtain a resin. The powdered resin obtained by pulverizing this was cured for 2 hours in a hot air dryer at 120°C.

When the adsorption capacity of this resin was measured in the same manner as in Example 1, it was found to be 0.28 meq/g resin.

Claims (5)

[Claims] (1) In a phenolic chelating ion exchange resin in which a chelate group is introduced into the phenol nucleus of phenols,
The chelate group has a general formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (However, M is an alkali metal or hydrogen, R_1, R_
2 represents hydrogen or an alkyl group. ) A phenolic chelating ion exchange resin characterized by being a phenolic compound represented by: (2) The ion exchange resin according to claim 1, wherein M in the general formula is an alkali metal. (3) The ion exchange resin according to claim 1 or 2, wherein the phenol compound has a molar ratio of 0.1 to 0.5 with respect to the total phenol. (4) The ion exchange resin according to any one of claims 1 to 3, wherein the phenolic chelating ion exchange resin has a small spherical shape. (5) Phenolic chelating ion exchange resin has a pH of 2
The ion exchange resin according to any one of claims 1 to 4, which hardly reduces the adsorption capacity for ferric ions in the following low pH range.