JP2018164905A - Aminophosphoric acid-type chelate resin and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To develop a chelate resin which can be easily and efficiently produced and has an improved chelating ability for a chelate resin applied to a treatment step of industrial waste water and recovery of valuable metals, and to develop a method for manufacturing the chelate resin.SOLUTION: The use of a chelate rein having an amino phosphate group introduced into primary amino groups of the polyvinylamine crosslinked polymer particles can facilitate efficient adsorption and separation of metal ions in water. The chelate resin can be obtained by a production method in which an N-vinyl carboxylic acid amide is suspension polymerized with a crosslinkable monomer in salt water in the presence of a dispersant to obtain a polyvinyl carboxylic acid amide crosslinked polymer particles, and then the obtained polyvinyl carboxylic acid amide crosslinked polymer is hydrolyzed to introduce an amino phosphate group into primary amino groups of the polyvinylamine crosslinked polymer particles.SELECTED DRAWING: None

Description

The present invention relates to an aminophosphate chelate resin and a method for producing the same.

In the process of industrial wastewater treatment and recovery of valuable metals, the adsorption treatment of dissolved metal using a chelate resin is a widely performed purification process. The chelating resin has functional groups adapted to the type of metal to be treated, such as iminodiacetic acid group, polyamine group, aminophosphate group, isothionium group, dithiocarbamic acid group, glucamine group, etc. Is possible. Particularly, aminophosphate-type chelate resin is a chelate resin that can be suitably used for, for example, purification of salt water used as a raw material for electrolytic caustic soda and can efficiently remove calcium, strontium, and the like, which are impurities in salt water. . In addition, as described in Patent Document 1 and Patent Document 2, aminophosphate-type chelate resins are less likely to undergo volume changes due to metal desorption and pH fluctuations as seen in other functional group resins. It is an excellent resin that can withstand.
One of the factors that determine the chelating ability of the chelating resin is the amount of functional groups per volume and weight. It is theoretically expected that if the amount of functional group is large, the chelating ability is excellent compared to the case of a small amount. In order to increase the amount of the functional group, it is important that the mass of the functional group that can be a reaction point in the polymer constituting the chelate resin is larger than the mass of the other components.

Various ideas have been made so far regarding chelate resins having aminophosphate groups. For example, in Patent Document 3, when a halomethyl group of a polymer having a halomethyl group in an aromatic nucleus is aminated and then further phosphorylated to produce an aminophosphate-type chelate resin, monoamine and polyamine are used. A method for producing an aminophosphate-type chelate resin in which the amination reaction is performed using a mixed amine having a proportion of 20 to 70% by weight is disclosed. In Patent Document 4, in a method for producing an aminophosphate chelate resin by amination of a halomethyl group of a polymer having a halomethyl group in an aromatic ring and then phosphorylation, halogen is selected as a polymer having a halomethyl group. A method for producing an aminophosphate chelate resin using a polymer containing 20% by weight is disclosed. Patent Document 5 discloses a cation exchanger or a chelate-former containing a specific structural unit and a structural unit derived from an unsaturated hydrocarbon group-containing crosslinkable monomer. Is also described. However, the chelating resins currently used widely including these prior arts may not always have a satisfactory adsorption effect. In addition, a simpler method for producing a chelate resin without practical steps is practical. Thus, there is a demand for chelate resins that can be easily and efficiently manufactured, and that can be efficiently adsorbed and separated, compared to conventional chelate resins used for metal ion adsorption.

Japanese Patent Laid-Open No. 51-35684 JP 52-50391 A JP-A-5-32714 JP-A-5-320233 International Publication No. 98/04598

An object of the present invention is to easily and efficiently produce a chelate resin that can be applied to desalted water production and industrial wastewater treatment process, has a functional group density higher than that of existing chelate resins, and has excellent adsorption capacity. It is in providing the chelate resin which has, and its manufacturing method.

As a result of diligent studies to solve the above problems, first, polyvinyl carboxylic acid amide crosslinked polymer particles are obtained by suspension polymerization of N-vinylcarboxylic amide in salt water in the presence of a crosslinking monomer and a dispersant. After the salt and the like are removed by washing with water, hydrolysis is carried out to obtain polyvinylamine crosslinked polymer particles. Then, it discovered that the aminophosphate type chelate resin which introduce | transduced the aminophosphate group into the primary amino group which polyvinylamine crosslinked polymer particle has is effective for metal ion adsorption | suction.

That is, in the present invention, N-vinylcarboxylic acid amide and a crosslinkable monomer are suspension-polymerized in salt water in the presence of a dispersant to obtain polyvinylcarboxylic acid amide crosslinked polymer particles, and then the crosslinked polymer is hydrolyzed. The present invention relates to an aminophosphate chelate resin in which an aminophosphate group is introduced into a primary amino group of a polyvinylamine crosslinked polymer particle obtained by decomposition, and a method for producing the same.

According to the present invention, an aminophosphate chelate resin produced by a production method for introducing an aminophosphate group into a primary amino group of a polyvinylamine crosslinked polymer particle obtained easily and efficiently without using an organic solvent is used. By doing so, metal ions in water can be adsorbed efficiently.

Hereinafter, the present invention will be described in detail.

The chelate resin in the present invention is one in which an aminophosphate group is introduced into the primary amino group of the polyvinylamine crosslinked polymer particles. First, a method for producing polyvinylamine crosslinked polymer particles will be described. A suspension polymerization method is applied as a production method. That is, unlike ordinary suspension polymerization, in the present invention, since a specific water-soluble monomer is used, suspension polymerization in high-concentration salt water is performed. Specifically, N-vinylcarboxylic acid amide, a crosslinkable monomer, a monomer that can be copolymerized with N-vinylcarboxylic acid amide as needed, a polymerization initiator, and a dispersing agent are suspended in salt water. The monomer droplets can be generated by stirring at an arbitrary strength and radical polymerization can be performed. The particle size of the monomer droplets is controlled by the dispersant and the stirring strength, but is 0.01 mm to 10 mm, preferably 0.1 mm to 5 mm.

Examples of N-vinylcarboxylic acid amide monomers used in the present invention include N-vinylformamide, N-methyl-N-vinylformamide, N-vinylacetamide, N-methyl-N-vinylacetamide, N-vinylpropion. Examples include amide, N-methyl-N-vinylpropionamide, N-vinylbutyramide, N-vinylisobutyramide, and preferably N-vinylformamide and N-vinylacetamide. In addition to the monomer of N-vinylcarboxylic acid amide, a monomer copolymerizable with N-vinylcarboxylic acid amide may be used. (Meth) acrylonitrile, (meth) acrylamide, N-alkyl (meth) acrylamide, N, N'-dialkyl (meth) acrylamide, N, N'-dialkylaminoalkyl (meth) acrylamide, alkali metal salt or ammonium salt of (meth) acrylamide alkanesulfonic acid, alkali metal salt or ammonium salt of (meth) acrylic acid, Hydroxyalkyl (meth) acrylate, dialkylaminoalkyl (meth) acrylate, (meth) acryloyloxyalkyltrimethylammonium salt, alkali metal salt or ammonium salt of (meth) acryloyloxyalkanesulfonic acid, N-bi Examples include rupyrrolidone, diallyldialkylammonium salt, vinylpyridine, vinylimidazole, vinylpentyltrialkylammonium salt, alkali metal salt or ammonium salt of vinylsulfonic acid, and one of these may be used. More than one species may be combined. Particularly preferred is acrylonitrile.

Examples of the crosslinkable monomer include aromatic polyvinyl compounds such as divinylbenzene, trivinylbenzene, and divinyltoluene, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, glycerol di (meth) acrylate, and trimethylolpropane tri Poly (meth) acrylates such as (meth) acrylate, methylenebisacrylamide, and the like can also be used. However, since poly (meth) acrylate, methylenebisacrylamide and the like are easily hydrolyzed, it is preferable to use an aromatic divinyl compound. Most preferred is divinylbenzene. In addition, allyl ethers such as triallyl cyanurate, triallyl isocyanurate, triallyl phosphate, triallylamine, tetraallyloxyethane, pentaerythritol diallyl ether, pentaerythritol triallyl ether, and pentaerythritol tetraallyl ether, poly ( Use may also be made of (meth) allyloxyalkanes. Among these, allyl ethers can be preferably used. The addition rate is in the range of 0.1 to 50% by mass with respect to the monomer, and preferably in the range of 0.1 to 20% by mass. If it exceeds 5% by mass, it is difficult to obtain spherical particles with N-vinylcarboxylic acid amide alone, so it is preferable to use a monomer that can be copolymerized with N-vinylcarboxylic acid amide. The addition ratio of the monomer capable of copolymerization is used in the range of 0.1 to 50% by mass with respect to all monomers. In particular, acrylonitrile is preferably used.

As the polymerization initiator, an azo- or peroxide-based polymerization initiator such as 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (4-methoxy-2,4-dimethyl) is used. Valeronitrile), 2,2′-azobis (2-methylpropionitrile), 2,2′-azobis-2-amidinopropane hydrochloride, 4,4′-azobis-4-cyanovaleric acid, 2,2′- Azobis [2- (5-methyl-imidazolin-2-yl) propane] hydrochloride, 2,2′-azobis [2- (2-imidazolin-2-yl) propane] hydrochloride, ammonium peroxodisulfate or potassium, Hydrogen peroxide, benzoyl peroxide, lauroyl peroxide, octanoyl peroxide, succinic peroxide, t-butylperoxy- - ethyl hexanoate, and the like. Of these, oil-soluble initiators such as 2,2'-azobis (2,4-dimethylvaleronitrile) and 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile) are preferred. Further, two or more initiators may be used in combination. The addition rate is usually 0.02 to 5% by mass, preferably 0.05 to 2% by mass, based on the monomer.

  Examples of the salt include ammonium sulfate, sodium sulfate, ammonium chloride, sodium chloride, calcium chloride and the like, and among these, ammonium sulfate is particularly preferable. These may be used alone or in combination. The addition rate is in the range of 30 to 100% by mass with respect to water, and if it is less than 30% by mass, the N-vinylcarboxylic acid amide is not separated into two phases, and the effect of the salt is sufficiently obtained at 100% by mass, It is not economical to add over 100% by mass. Preferably it is 50-90 mass%, More preferably, it is 60-90 mass%.

As the dispersant, a polymer dispersant is preferable. The polymer dispersant can be used either ionic or nonionic, but is preferably ionic. Examples of the ionic polymer include polyacryloyloxyethyltrimethylammonium chloride and polydimethyldiallylammonium chloride obtained by homopolymerizing the cationic monomer (meth) acryloyloxyethyltrimethylammonium chloride, dimethyldiallylammonium chloride, and the like. However, copolymers of these cationic monomers and nonionic monomers can also be used. Examples of nonionic monomers include acrylamide, N-vinylformamide, N-vinylacetamide, N-vinylpyrrolidone, N, N′-dimethylacrylamide, acrylonitrile, diacetone acrylamide, 2-hydroxyethyl (meth) acrylate, and the like. Can be mentioned. Examples of the nonionic polymer dispersant include polyvinyl alcohol and polyethylene glycol polyacrylamide. The weight average molecular weight of the ionic polymer dispersant is 5,000 to 5,000,000, preferably 50,000 to 3,000,000. Moreover, as a weight average molecular weight of a nonionic polymer dispersing agent, it is 1000-100,000, Preferably it is 1000-50,000. The addition rate is usually 0.05 to 5% by mass, preferably 0.1 to 2% by mass, based on water.

The polymerization reaction is usually performed at a temperature of 30 ° C. to 100 ° C. and for a time of 1 hour to 15 hours.

After the polymerization, salt, dispersant, unreacted monomer and the like can be removed by washing with water.

The copolymer particles are purified by the method described above and then subjected to hydrolysis. Hydrolysis of N-vinylcarboxylic acid amide crosslinked polymer particles can be carried out under basic and acidic conditions. To obtain free polyvinylamine crosslinked polymer particles, hydrolysis must be carried out under basic conditions. Is preferred. In order to obtain salt-type polyvinylamine crosslinked polymer particles, it is preferable to hydrolyze under acidic conditions.

A suitable base for hydrolysis is not particularly limited as long as the pH can be adjusted to a range of 8 to 14 during hydrolysis, and an aqueous solution of sodium hydroxide, potassium hydroxide or ammonia is most preferably used. The addition rate is preferably 0.05 to 2.0, more preferably 0.4 to 1.2 equivalents relative to the formyl group of the polymer.

The acid suitable for the hydrolysis is not particularly limited as long as the pH can be adjusted to a range of 0 to 5 during the hydrolysis, and includes inorganic acids such as hydrohalic acid, sulfuric acid, nitric acid and phosphoric acid, and one carbon atom. Examples thereof include organic acids such as mono- and dicarboxylic acids, sulfonic acids, benzenesulfonic acids, and toluenesulfonic acids in the range of ˜5, and it is particularly preferable to use hydrohalic acid and hydrogen halide gas, and use hydrohalic acid. Most preferred. The addition rate is preferably 0.05 to 2.0, more preferably 0.4 to 1.2 equivalents relative to the formyl group of the polymer.

  Polyvinylamine crosslinked polymer particles can be obtained by washing with water after hydrolysis. In the case of base hydrolysis, free-type purified polyvinylamine crosslinked polymer particles are obtained, and in the case of acid hydrolysis, salt-type purified polyvinylamine crosslinked polymer particles are obtained.

  Next, introduction of an aminophosphate group will be described. The aminophosphate-type chelate resin having an aminophosphate group introduced therein can be obtained by reacting one equivalent of formaldehyde and phosphonic acid under acid or alkaline conditions with the amino group in the polyvinylamine crosslinked polymer particles prepared in advance. This reaction introduces an aminophosphate group into the primary amino group. When the aminophosphate group is introduced in an amount of 25% by mass or more based on the dry mass after introduction, the effect as a chelate resin is remarkable, and 30% by mass or more is preferable.

  Although acidic conditions have already been achieved by using phosphonic acid, a reagent capable of supplying protons such as hydrochloric acid, phosphoric acid, sulfuric acid, etc. may be added.

Alkaline conditions are achieved by using a reagent capable of supplying hydroxide ions, carbonate ions and the like. It is necessary to use one or more equivalents of these with respect to phosphonic acid.

As the formaldehyde, either a liquid such as formalin or a solid such as paraformaldehyde may be used. The addition amount is preferably 0.05 to 5.0, more preferably 0.4 to 1.2 equivalents relative to the amino group of the polymer.

The phosphonic acid is preferably added in an amount of 0.05 to 5.0, more preferably 0.4 to 1.2 equivalents relative to the amino group of the polymer.

  The reaction temperature can be in the range of 20 to 100 ° C. When it is 20 ° C., the reaction rate is slow, and when it is 100 ° C., it is necessary to use a reflux apparatus. 40-95 degreeC is preferable and 60-95 degreeC is still more preferable.

The reaction time is 2 to 96 hours, but depending on the conditions, the reaction may proceed even after 96 hours.

  Next, a method for adsorbing and separating metal ions with a chelate resin in the present invention will be described. The chelate resin in the present invention is applied to a general water treatment application as a chelate resin. In general, a column is filled and drainage is passed to adsorb metal ions. In addition, after adding to a target liquid, it mixes by arbitrary stirring conditions, such as a turbulent flow and a laminar flow, and adsorb | sucks a target object. That is, it exhibits high adsorption capacity for metal ions in various industrial and process wastewaters. In addition, the crosslinked polymer particles in the present invention are preferably spherical, and the spherical polymer tends to have a high ability to adsorb metal ions, and when used in a column as an adsorbent, the packing efficiency is high and the flow path is high. There are advantages such as stability, separation efficiency is increased, and processing capacity is improved.

  The chelate resin in the present invention has a high ability to adsorb metal ions, but among metal ions, it exhibits a higher ability to adsorb alkaline earth metal ions such as calcium ions and strontium ions.

   EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not restrict | limited to a following example, unless the summary is exceeded. First, polyvinylamine crosslinked polymer particles were produced, and then an aminophosphate group was introduced to produce a chelate resin in the present invention. Moreover, the adsorption ability of the metal ion of the chelate resin in the present invention was evaluated.

(Production Example 1 of Polyvinylamine Crosslinked Polymer Particles)
A 500 mL four-necked flask was charged with 100 g of demineralized water, 64.0 g of ammonium sulfate, and 1.00 g of a polyacryloyloxyethyltrimethylammonium chloride aqueous solution (polymer concentration 20% by mass, weight average molecular weight 800,000), stirred and dissolved. A polymerization bath was used. N-vinylformamide 33.4 g, divinylbenzene 2.80 g, acrylonitrile 4.00 g, azo polymerization initiator 2, 2′-azobis (4-methoxy-2,4-dimethylvaleronitrile) (V-70, Wako Pure) 0.12 g (manufactured by Yakuhin Kogyo Co., Ltd.) was mixed to prepare a monomer solution. The monomer solution and the polymerization bath were mixed and stirred at 180 rpm while replacing the inside of the flask with nitrogen. After 30 minutes, the temperature was raised, and polymerization was carried out at 45 ° C. for 3 hours and then at 60 ° C. for 2 hours. After the polymerization, filtration, washing with water and filtration were carried out to obtain 88.9 g of water-containing polymer spherical particles. The solid content was 38.8%. 51.6 g of the reaction product thus obtained was placed in a four-necked flask, 46.8 g of a 48% by mass aqueous sodium hydroxide solution was added, and the mixture was hydrolyzed at 80 ° C. for 7 hours with stirring. Washing with water and filtration yielded 19.7 g of polyvinylamine spherical particles containing water. As a result of microscopic observation, spherical particles of 50 μm to 2 mm were observed. The polymer particles thus obtained are referred to as polyvinylamine crosslinked polymer particles 1.

(Production Example 2 of Polyvinylamine Crosslinked Polymer Particles)
961 g of demineralized water, 640 g of ammonium sulfate, and 4.0 g of polyacryloyloxyethyltrimethylammonium chloride aqueous solution (polymer concentration 20 mass%, weight average molecular weight 800,000) are charged into a 3000 mL four-necked flask, stirred, dissolved and polymerized. It was a bath. N-vinylformamide 360 g, divinylbenzene 20.0 g, acrylonitrile 20.0 g, azo polymerization initiator 2, 2′-azobis (4-methoxy-2,4-dimethylvaleronitrile) (V-70, Wako Pure Chemical Industries, Ltd.) 1.2 g) was mixed to make a monomer solution. The monomer solution and the polymerization bath were mixed and stirred at 110 rpm while replacing the inside of the flask with nitrogen. After 30 minutes, the temperature was raised, and polymerization was carried out at 50 ° C. for 3 hours and then at 60 ° C. for 1 hour. After the polymerization, filtration, washing with water and filtration were carried out to obtain 1107 g of polymer spherical particles containing water. The solid content was 31.0%. 645 g of the reaction product thus obtained was placed in a four-necked flask, 468 g of a 48% by mass aqueous sodium hydroxide solution was added, and the mixture was hydrolyzed at 80 ° C. for 6 hours with stirring. Washing with water and filtration yielded 689 g of water-containing polyvinylamine spherical particles. As a result of microscopic observation, spherical particles of 50 μm to 2 mm were observed. The polymer particles thus obtained are referred to as polyvinylamine crosslinked polymer particles 2.

(Production Example 3 of Polyvinylamine Crosslinked Polymer Particles)
A 300 mL four-necked flask was charged with 99.1 g of demineralized water, 64.2 g of ammonium sulfate, and 1.1 g of a polyacryloyloxyethyltrimethylammonium chloride aqueous solution (polymer concentration 20% by mass, weight average molecular weight 800,000), stirred, Dissolved to form a polymerization bath. N-vinylformamide 35.2 g, divinylbenzene 2.41 g, acrylonitrile 2.41 g, azo polymerization initiator 2, 2′-azobis (4-methoxy-2,4-dimethylvaleronitrile) (V-70, Wako Pure) 0.12 g (manufactured by Yakuhin Kogyo Co., Ltd.) was mixed to prepare a monomer solution. The monomer solution and the polymerization bath were mixed and stirred at 180 rpm while replacing the inside of the flask with nitrogen. After 30 minutes, the temperature was raised, and polymerization was carried out at 45 ° C. for 3 hours and then at 60 ° C. for 2 hours. After the polymerization, filtration, washing with water and filtration were carried out to obtain 97.3 g of polymer spherical particles containing water. The solid content rate was 35.3%. 56.7 g of the reaction product thus obtained was placed in a four-necked flask, 46.8 g of a 48% by mass aqueous sodium hydroxide solution was added, and the mixture was hydrolyzed at 80 ° C. for 6 hours with stirring. After washing with water and filtering, 55.4 g of water-containing polyvinylamine spherical particles were obtained. As a result of microscopic observation, spherical particles of 50 μm to 2 mm were observed. The polymer particles thus obtained are referred to as polyvinylamine crosslinked polymer particles 3.

(Production Example 4 of Polyvinylamine Crosslinked Polymer Particles)
A 500 mL four-necked flask was charged with 100 g of demineralized water, 64.0 g of ammonium sulfate, and 1.00 g of a polyacryloyloxyethyltrimethylammonium chloride aqueous solution (polymer concentration 20% by mass, weight average molecular weight 800,000), stirred and dissolved. A polymerization bath was used. N-vinylformamide 33.4 g, pentaerythritol triallyl ether (Neoallyl P-30, manufactured by Daiso Corporation) 1.00 g, acrylonitrile 1.00 g, azo polymerization initiator 2, 2′-azobis (4-methoxy- 2,4-dimethylvaleronitrile) (V-70, manufactured by Wako Pure Chemical Industries, Ltd.) 0.12 g was mixed to prepare a monomer solution. The monomer solution and the polymerization bath were mixed and stirred at 180 rpm while replacing the inside of the flask with nitrogen. After 30 minutes, the temperature was raised, and polymerization was carried out at 40 ° C. for 3 hours and then at 70 ° C. for 2 hours. After the polymerization, filtration, washing and filtration were performed to obtain 210 g of polymer spherical particles containing water. The solid content was 15.7%. 150 g of the reaction product thus obtained was placed in a four-necked flask, 14.0 g of a 48% by mass aqueous sodium hydroxide solution was added, and the mixture was hydrolyzed at 80 ° C. for 5 hours with stirring. Washed with water and filtered to obtain 253 g of polyvinylamine spherical particles containing water. As a result of microscopic observation, spherical particles of 50 μm to 2 mm were observed. The polymer particles thus obtained are referred to as polyvinylamine crosslinked polymer particles 4.

(Aminophosphate-type chelate resin production example 1)
500 mL separable polyvinylamine crosslinked polymer particles 1 50.0 g (dry weight 12.7 g), deionized water 40.0 g, 48% sodium hydroxide 29.5 g, paraformaldehyde 20.0 g, phosphonic acid 36.3 g The mixture was added to the flask, heated to 80 ° C. with stirring, and reacted for 4 hours with stirring. After standing to cool, 55.8 g (dry mass 24.3 g) of aminophosphate-type chelate resin was obtained by filtration. 1.9 g of aminophosphate groups were introduced with respect to 1 g of polyvinylamine crosslinked polymer particles (dry mass). That is, 50 mass% of aminophosphate groups were introduced with respect to the dry mass after introduction. This chelate resin is referred to as Production Example 1.

(Aminophosphate-type chelate resin production example 2)
50.0 g (dry weight 12.7 g) of polyvinylamine crosslinked polymer particles 1, 40.0 g of deionized water, 35.9 g of 35% hydrochloric acid, 20.0 g of paraformaldehyde, and 36.3 g of phosphonic acid in a 500 mL separable flask. In addition, the mixture was heated to 80 ° C. with stirring, and reacted for 4 hours with stirring. After allowing to cool, 48.5 g of aminophosphate-type chelate resin (dry mass 20.6 g) was obtained by filtration. 1.6 g of aminophosphate groups were introduced per 1 g (dry mass) of the polyvinylamine crosslinked polymer particles. That is, 34 mass% of aminophosphate groups were introduced with respect to the dry mass after introduction. This chelate resin is referred to as Production Example 2.

(Aminophosphate-type chelate resin production example 3)
50.0 g (dry weight 13.5 g) of polyvinylamine cross-linked polymer particles 2, 30.0 g of deionized water, 21.9 g of paraformaldehyde, and 39.9 g of phosphonic acid were added to a 500 mL separable flask and stirred at 100 ° C. And allowed to react for 20 hours with stirring. After allowing to cool, 63.7 g (dry mass 29.7 g) of aminophosphate chelate resin was obtained by filtration. 2.2 g of aminophosphate groups were introduced per 1 g of polyvinylamine crosslinked polymer particles (dry mass). That is, 62 mass% of amino phosphate groups were introduced with respect to the dry mass after introduction. This chelate resin is referred to as Production Example 3.

(Test Example 1) Calcium ion adsorption test Calcium chloride dihydrate was dissolved in ion-exchanged water to prepare 1000 mL of a 100 ppm calcium ion solution. 100 mg of the aminophosphate-type chelate resin of Production Example 3 wet in water was added to 200 g of the calcium ion solution, and the mixture was stirred at 40 rpm using a stirrer. Supernatant liquid was sampled 24 hours after the start of stirring, filtered through a 0.2 μm filter, and the remaining amount of calcium ions in the obtained liquid was measured with an atomic absorption spectrophotometer (AA-6800, manufactured by Shimadzu Corporation). did. From the measured value, the adsorption amount (g) with respect to 1 g of the chelate resin wet mass was determined.

(Test Comparative Example 1) Calcium ion adsorption test Calcium chloride dihydrate was dissolved in ion-exchanged water to prepare 1000 mL of a 100 ppm calcium ion solution. As a comparative product, Diaion CR20 (polyamine type chelate resin), which is a general-purpose product as a commercially available chelate resin, was wetted with water, and 100 mg was added to 200 g of the calcium ion solution. The mixture was stirred at 40 rpm using a stirrer, and the supernatant was sampled 24 hours after the start of stirring, and filtered with a 0.2 μm filter. Measured by Shimadzu Corporation). From the measured value, the adsorption amount (g) with respect to 1 g of the chelate resin wet mass was determined. The results are shown in Table 1.

(Table 1)

When the aminophosphate chelate resin in the present invention was added, it was confirmed that the adsorption performance of calcium ions was higher than that of the chelate resin which is a general-purpose product.

Claims (3)

A chelate resin comprising 25 mass% or more of an aminophosphate group introduced into a primary amino group of a polyvinylamine crosslinked polymer particle, based on a dry mass after introduction. After hydrolyzing the crosslinked polymer particles obtained by suspension polymerization in the presence of a dispersant in salt water containing N-vinylcarboxylic acid amide and a crosslinking monomer to obtain polyvinylamine crosslinked polymer particles, A method for producing a chelate resin, wherein an aminophosphate group is introduced into a primary amino group of a polyvinylamine crosslinked polymer particle. The method for producing a chelate resin according to claim 2, wherein 25 mass% or more of an aminophosphate group is introduced into the primary amino group of the polyvinylamine crosslinked polymer particles based on the dry mass after introduction.