KR100290540B1 - Specific heavy metal ion adsorption chelate resin - Google Patents

Abstract

The present invention relates to a chelate resin for adsorption of specific heavy metal ions, and more particularly, a copolymer having a structure capable of converting a carboxyl group to a main chain side and sylene, but having divinylbenzene as a crosslinking agent. After synthesizing the copolymers, by adding carboxyl groups to the phenyl groups of these copolymers, the basic skeleton of the chelate functional groups of the copolymer resin is uneven with benzene as a spacer. The present invention relates to a chelating resin for adsorption of a specific heavy metal ion containing only a carboxyl group represented by the formula (1) and then selectively strengthening the chelate formation ability for the specific heavy metal ions.

In Formula 1, A represents a hydrogen atom or a sodium atom; If Z = 0 then X = Y = 1 and if Z = 1 then X = 0 and Y = 1.

Description

Chelating resin for adsorption of certain heavy metal ions

The present invention relates to a chelate resin for adsorption of specific heavy metal ions, and more particularly, copolymerizes styrene and a monomer having a structure which can be converted into a carboxyl group on the main chain side, and divinylbenzene is used as a crosslinking agent. After synthesizing the copolymer, by adding carboxyl groups to the phenyl group of these copolymers, the basic skeleton of the chelate functional groups of the copolymer resin is uneven with benzene as a spacer. The present invention relates to a chelate resin for adsorption of a specific heavy metal ion containing only a carboxyl group represented by Formula 1, after which the chelate formation ability for specific heavy metal ions is further enhanced.

Formula 1

In Formula 1, A represents a hydrogen atom or a sodium atom; If Z = 0 then X = Y = 1 and if Z = 1 then X = 0 and Y = 1.

According to the results studied so far, chelate resins having a carboxyl group as a functional group have been reported to be effective for chelation of Ca + ² or Fe ^{+ 3} ions [J. Colloid Interface Sci., 161, 455 (1993), Biophys, Chem., 57, 133 (1996), Zhongguo Fangzhi Daxue Xuebao 17, 57 (1991), Japanese Patent Laid-Open No. 3-124,711, Japanese Patent Laid-Open No. 5- 138,046 and Japanese Patent Laid-Open No. 8-010,763. In addition, chelate resins having a carboxyl group, a sulfonic group and a phosphono group together prepared by copolymerization of tetraethyl ester of vinylidene diphosphonic acid, butyl acrylate, styrene and divinylbenzene and undergoing partial hydrolysis and sulfonation (Macromolecules, 29, 1021 (1996)] is effective for the adsorption of Eu + 3 ions, but has a low copolymerization yield and is obtained in the form of a mixture of spherical and powder.

In addition, examples of the chelating agent and the related resins made by mixing a carboxyl group with another chelate functional group as a functional group are as follows. Phosphoric acid group, amine group and carboxyl group were used together as a dispersant to suppress scale (US Pat. No. 5,534,611). The amine group and carboxyl group were applied together to impart bleaching function through the formation of iron salt or oxidation of silver (Ag) (German Patent No. 3,621,025 (1987)).

In the present invention, if the carboxyl groups are arranged in the main chain and the side chain of the copolymer while having a basic skeleton structure similar to that of US Patent No. 5,457,163, unlike the conventional chelate resin, the adsorption capacity for a particular heavy metal ion that can be chelated only by the carboxyl group is significantly increased. The present invention has been completed by knowing that it can.

Therefore, in the present invention, in order to make a basic skeleton structure similar to US Patent No. 5,457,163, a carboxyl group structure capable of chelate formation is introduced in the main chain, which is a basic skeleton of the copolymer resin, and again a chelate is formed in the chloromethyl group, which is a side chain of the copolymer resin. By introducing a carboxyl group for the carboxyl groups introduced into the side chain chloromethyl group in the backbone of the copolymer resin, the carboxyl groups arranged in the main chain with each other uneven Characterized by the chelate resin for adsorption of a specific heavy metal ion represented by the following formula (1) having a structure.

Formula 1

In Formula 1, A represents a hydrogen atom or a sodium atom; If Z = 0 then X = Y = 1 and if Z = 1 then X = 0 and Y = 1.

Referring to the present invention in more detail as follows.

In the present invention, in preparing a resin that effectively chelates certain heavy metal ions, a carboxylic acid ester (dibutyl maleate, dibutyl fumarate, itaconic acid dibutyl ester) as a monomer having a structure that can be converted to a carboxyl group And copolymerize vinyl monomers such as chloromethylated styrene and divinylbenzene, and then hydrolyze to form a carboxyl group structure capable of chelate in the basic skeleton of the copolymer resin, and again, the chloromethyl group, the side chain of the copolymer basic skeleton, in ethanol solvent. Nucleophilic substitution was carried out by caustic carry, and chlorine was converted to a hydroxyl group, and the hydroxyl group was oxidized to concentrated nitric acid to convert to a carboxyl group.

The chelating resin prepared by the production method according to the present invention has a carboxyl group of a carboxyl group in both the main chain and the side chain of the basic skeleton, and the carboxyl group introduced into the phenyl, which is the side chain, has a peak and the carboxyl groups of the main chain and the carboxyl group of the side chain. Irregularities in between By making the structure, the ability to chelate for a particular heavy metal ion is improved.

In addition, the chelate resin of the present invention has a structure directly bonded to the carbon atoms of the chelate functional groups, so that the structure of each functional group is desorbed by hydrolysis in the presence of an acid or alkaline solution during regeneration in which the adsorption-desorption process is repeated. Iii) it does not contaminate the solution and has good chelate formation as well as durability that can be reused.

Schematically illustrating the manufacturing process of the chelate resin according to the present invention can be represented by the following scheme 1.

In Scheme 1, when Z = 0, X = Y = 1, and when Z = 1, X = 0 and Y = 1.

The chelate resin preparation method of the present invention according to Scheme 1 will be described in more detail. First, toluene is added as a diluent to monomers such as chloromethylated styrene, divinylbenzene, and dibutyl maleate, and a radical initiator is added thereto. Suspension polymerization at 2 ℃ for 50 hours to prepare a copolymer represented by the formula (2). When the copolymer represented by Chemical Formula 2 is hydrolyzed at 40 to 100 ° C. for 1 to 60 hours in the presence of an acid catalyst, a copolymer containing a carboxyl group is prepared in the main chain represented by Chemical Formula 3. Here, the copolymerization between dibutyl maleate, a hydrophilic carboxylic acid ester, and monomers, such as relatively lipophilic styrene and divinylbenzene, is a suspension polymerization method. Is formed in a spherical shape, the inside of the sphere contains a lot of the structure of the lipophilic styrene and divinylbenzene, the outside of the sphere is arranged a lot of dibutyl maleate structure of high hydrophilicity.

Then, the chloromethyl group, which is the side chain of the basic skeleton of the copolymer represented by Chemical Formula 3, was nucleophilic for 0.5 to 5 parts by weight in a ethanol solvent of 5 to 20 parts by weight in an ethanol solvent at 5 to 20 parts by weight at 50 to 80 ° C. for 10 to 50 hours. Substitution reaction is hydroxylated chlorine of the chloromethyl group to prepare a hydroxylated copolymer represented by the formula (4). Subsequently, 5-30 weight percent concentrated nitric acid per weight of the copolymer dried by hydroxylation at 20-60 ° C., oxidized for 5-50 hours, washed and dried to have a double functional group represented by Chemical Formula 1a. A type chelate resin is prepared.

In addition, the Na-type chelate resin represented by Chemical Formula 1b is prepared by neutralizing the H-type chelate resin represented by Chemical Formula 1a to increase hydrophilicity and to improve adsorption capacity.

The chelating resin according to the present invention is a carboxyl group introduced into the phenyl group, which is the side chain of the basic skeleton of the copolymer, with the carboxyl group and the unevenness in the main chain of the basic skeleton. By the arrangement of states, having a new molecular arrangement by only carboxyl groups, it is possible to expect selective chelate formation ability for specific heavy metal ions.

On the other hand, the carboxylic acid ester represented by dibutyl maleate in Scheme 1 is preferably used within 0.60 mol% (maximum in solution polymerization) in the total composition of the copolymer, if the content of the carboxylic acid ester is 0.60 mol If it exceeds%, a copolymer having a spherical shape is obtained, which is not preferable because the specific surface area of the chelating resin is significantly lowered.

In addition, the divinylbenzene used as a crosslinking agent in the copolymerization in the present invention is preferably used within the range of 2.0 to 30% by weight based on the total amount of the monomers used. In other words, divinylbenzene is a crosslinking agent that gives mechanical strength to the styrene-based spheroidal copolymer and acts as a ladder of the network structure through which heavy metal ions can enter. It is not good and if too large, the surface area becomes small due to the increase in the degree of crosslinking and the adsorption effect is reduced, which is not good.

In addition, a small amount of organic diluents such as toluene, cyclohexane, etc. which can be used in the copolymerization in the present invention is used at a ratio of 2.0 to 20% by weight based on the total amount of the monomers used, and these are used as precipitants on the surface of the spherical copolymer. Physical irregularities It is used to make the structure, and after the reaction, it is physically mixed in the spherical copolymer, and by drying them, the specific surface area of the spherical copolymer is increased.

In the present invention, a radical polymerization method is used, wherein as the radical initiator, benzoyl peroxide, p, p'-dichlorobenzoyl peroxide, methyl ethyl ketone peroxide, cumene hydroperoxide and di-t-butyl peroxide And peroxide initiators such as potassium persulfate or ammonium photosulphate, and azo radical initiators such as bisazisoisobutylonitrile.

In addition, the copolymerization method of the present invention uses a radical suspension polymerization method, wherein the suspending agent is methyl cellulose, partially hydrolyzed polyvinyl alcohol, polyvinylpyrrolidone or a mixture thereof. Here, the amount of the suspending agent is 0.01 to 4.0% by weight, preferably 0.1 to 2.0% by weight relative to the total amount of the monomer used.

In general, such suspension polymerization is carried out in an aqueous dispersion (aqueous dispersion), the radical polymerization occurs in the aqueous dispersion even in the copolymerization method of the present invention, wherein the weight ratio of water to organic monomers is 0.5 to 15 weight ratio is good. If less 0.5 weight ratio of water is added, the viscosity becomes so large that it is difficult to obtain a uniform aqueous dispersion, whereas if less than 15 weight ratio is added, the viscosity becomes too large to obtain a uniform aqueous dispersion, whereas more than 15 weight ratio is added. This leads to low productivity and a large amount of water, which leads to high energy consumption, which is not good.

According to the present invention, the particle size of the spherical copolymer is controlled from the amount of the suspending agent and the weight ratio between the water and the organic monomers in the aqueous phase.

On the other hand, the hydrolysis according to the present invention is added to the ethanol and 1 ~ 20 times the ratio of concentrated hydrochloric acid in the ratio of 2 to 10 times by weight per dry copolymer weight and maintained at 40 to 100 ℃ for 1 to 60 hours, and then purified The volatiles can be blown off, the residue washed with water and methanol and dried.

On the other hand, the kinetic reaction of the carboxyl group with respect to the chloromethyl group which is a copolymer side chain obtained by the use of chloromethylated styrene in the present invention is 0.5 to 5 weight ratio of caustic carry under 5 to 20 weight ratio ethanol solvent per copolymer weight at 50 to 80 ° C. Nucleophilic substitution reaction for 10 to 50 hours to hydroxylate the chloromethyl group chlorine, filtered, washed, dried and then hydroxylated at 20 ~ 60 ℃ to add 5 to 30 parts by weight of concentrated nitric acid per weight of dried resin After 5 to 50 hours of oxidation, the reaction was separated by filtration, washed with distilled water and methanol and dried. Where the reaction temperature of the nucleophilic substitution is less than 50 ℃ or less than 10 hours, the conversion to the hydroxyl group was very low, the reaction for more than 50 hours did not help the conversion rate. On the other hand, in the case of the oxidation reaction for forming a carboxyl group, if the reaction temperature is too low, the conversion rate is very low, and if it is too high, oxidation is performed even in the minutes other than the hydroxyl group.

In addition, the neutralization in the present invention is a weight ratio of 5 to 15 times the weight of the copolymer at 30 ~ 90 ℃, stirred for 10 minutes to 3 hours using a caustic soda of 1 to 5 normal concentration, washed with distilled water, dried Just do it.

The chelating resin of the present invention prepared by the above production method is such that the molecular arrangement for the carboxyl functional groups form a selective chelate for some specific heavy metal ions, wherein the influence of the carboxyl group content on the main chain and side chain of the copolymers, crosslinking agent content and By considering the influence of the specific surface area, the reusability from adsorption-desorption, etc., it is possible to improve the selective adsorption and reusability compared to conventional carboxyl group-containing chelate resins.

Such a present invention will be described in more detail based on the following examples, but the present invention is not limited thereto.

Examples 1 to 24

Chloromethylated styrene, divinylbenzene, dibutylmaleate, and toluene were added to a reactor with a stirrer, and as a polymerization initiator, benzoyl peroxide was used in an amount of 0.2% by weight based on monomers. C) to 2.5 and a 1% aqueous solution of methyl cellulose was used as a dispersant.

The suspension polymerization was maintained at 70 ° C. for 25 hours, and the resulting polymerization product was filtered and washed with water, which was dried for 48 hours in a vacuum dryer maintained at 60 ° C. and then filtered through a 60/80 mesh sieve.

Introduction of the carboxyl group to the main chain of the copolymer is achieved by hydrolysis by refluxing at 90 ° C. for 42 hours, adding 4 parts by weight of methanol and 3 parts by weight of concentrated hydrochloric acid per weight of the dried resin obtained by copolymerizing the dibutyl maleate monomer. Its tablets blew away volatiles, washed the residue with distilled water and dried.

Subsequently, in order to introduce a carboxyl group to the chloromethyl group, which is a side chain of the main skeleton of the copolymer, nucleophilic substitution reaction with 2 parts by weight of caustic carbonate for 20 hours was carried out at 60 ° C. under an ethanol solvent of 10 parts by weight of the copolymer for 20 hours. The reaction mixture was filtered, washed, dried, and then oxidized at 40 ° C. to 10% by weight of concentrated nitric acid per weight of the dried resin, oxidized for 30 hours, and then the reaction product was filtered off, washed with distilled water and methanol, and 60 It dried under vacuum at 48 degreeC for 48 hours, and produced the yellow spherical chelating resin [H-type functional group].

The composition, the content of each functional group and the adsorption amount of heavy metal ions of the obtained chelate resin are as described in Table 1 (Examples 1 to 8).

In addition, the same composition as in Table 1, each functional group content by using a chelate resin having the adsorption / desorption of the corresponding heavy metal ions (desorption of ions with 1M hydrochloric acid at room temperature for 24 hours, neutralized, washed with 1M of soda) ) Was repeated four times, and then the adsorption amount of each ion was measured and described in the following Table 2 (Examples 9 to 16).

In addition, the same composition as in Table 1, each functional group content of the chelating resin having a 1 mol of home soda solution at room temperature, stirred for 3 hours, filtered, washed, and dried to remove the functional groups of the carboxyl group or the sulfonic group in the chelate resin The sodium salt type (Na type) was changed, and the adsorption amount of each ion was measured and described in the following Table 3 (Examples 17 to 24).

Comparative Examples 1 to 7

Chloromethylated styrene, butyl acrylate, divinylbenzene and toluene were added to a reactor with a stirrer, and as a polymerization initiator, benzoyl peroxide was used in an amount of 0.2% by weight based on monomers. C) to 2.5 and a 1% aqueous solution of methyl cellulose was used as a dispersant.

In this case, the suspension polymerization was maintained at 70 ° C. for 25 hours, and the resultant polymerization reaction was filtered and washed with water, and dried in a vacuum dryer maintained at 60 ° C. for 48 hours, and then filtered through a 60/80 mesh sieve. .

Introduction of the carboxyl group to the main chain of the copolymer was carried out by refluxing the mixture at 90 ° C. for 42 hours and adding methanol 4 weight ratio to 3 weight ratio of concentrated hydrochloric acid per weight of the dried resin obtained by copolymerizing the butyl acrylate monomer as described above. This was achieved by decomposition, and its purification was blown off volatiles, the residue was washed with distilled water and dried.

Thereafter, in the present invention, a method of introducing a carboxyl group into a chloromethyl group, which is a copolymer side chain obtained by using chloromethylated styrene, uses tetrabutylammonium bromide in a 1 weight ratio as a phase transfer catalyst per weight of copolymer resin at a reaction temperature of 60 ° C. After 6 hours of reaction with sodium nitrite for 7 hours, the reaction mixture was filtered off, washed with distilled water and methanol, and dried under vacuum at 60 ° C. for 48 hours to obtain a yellow spherical chelating resin [H-type functional group]. Prepared. The composition, the content of each functional group, and the heavy metal ion adsorption amount of the obtained chelate resin are as shown in Table 4 below.

Table 4

[Table 2]

Table 3

Table 4

As described above, the chelate resin of the present invention has a carbosyl group introduced as a chelating functional group in the main chain and the side chain of the basic skeleton, and forms a concave-convex structure between the carboxyl group introduced into the side chain and the carboxyl groups introduced into the main chain. Has the effect of significantly improved chelate formation ability.

Claims (1)

A carboxyl group is introduced into the main chain and the side chain of the basic skeleton, and the carboxyl group introduced into the phenyl group, which is a side chain, is at its peak, and the carboxyl functional groups and unevenness of the main chain are Chelating resin for a specific heavy metal ion adsorption represented by the following formula (1), characterized in that the structure. Formula 1 In Formula 1, A represents a hydrogen atom or a sodium atom; If Z = 0 then X = Y = 1 and if Z = 1 then X = 0 and Y = 1.