JP2772010B2 - Method for producing chelating resin adsorbent having iminodiacetic acid group - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a novel adsorbent applicable to removal of metal ions contained in service water in various fields such as precision electronics industry, medicine, pharmaceuticals, and nuclear power generation.

[Prior art] In conventional water treatment technologies, particulate ion exchange resins are widely used, but it is difficult to efficiently adsorb and separate low concentrations of dissolved ions, and a large amount of resin is required. And

In industrial effluents, the outflow of harmful heavy metals is a major social issue, and there is an urgent need to establish a technology for selectively separating and removing trace amounts of heavy metals such as cobalt, nickel, and copper.

[Problems to be Solved by the Invention] An object of the present invention is to provide an adsorbent capable of selectively adsorbing and desorbing a very small amount of heavy metal ions such as cobalt, nickel, and copper in a water treatment technique.

[Means for Solving the Problems] The present inventors have conducted intensive studies on the means for achieving the above object, and as a result, have found that the means can be achieved by the following means.

The base material is subjected to ionizing radiation on a polymer molded article comprising a polymer or copolymer of an olefin or a halogenated olefin, and after graft-polymerizing a polymerizable monomer containing an epoxy group, the graft polymer It has been found that by immobilizing an iminodiacetic acid group on the side chain, trace amounts of heavy metal components in an aqueous solution can be efficiently removed and separated, and a chemically and physically stable adsorbent can be obtained.

Hereinafter, the substrate to be graft-polymerized in the present invention is selected from polyethylene, polypropylene, polysulfone, polytetrafluoroethylene, or homo- or copolymers of ethylene, propylene, butene, hexene, tetrafluoroethylene, and chlorotrifluoroethylene. .

The shape of the polymer molded article used as the base material can be selected from various shapes such as fibers and nonwoven fibers, particles, powders, woven fabrics and sheets. In particular, the method of the present invention is characterized in that iminodiacetic acid groups can be immobilized without being limited to a shape.

The polymerizable monomer to be grafted to the base material is glycidyl methacrylate, glycidyl acrylate, glycidyl sorbate, glycidyl methitaconate, ethyl glycidyl maleate, glycidyl vinyl sulfonate, or the like, and is limited as long as it contains an epoxy group. Although not required, glycidyl methacrylate and glycidyl acrylate are suitable.

The ionizing radiation used in the graft polymerization of the present invention is an α-ray, a β-ray, a γ-ray, an accelerated electron beam, an X-ray, an ultraviolet ray, or the like.

According to the present invention, as a method of graft-polymerizing a polymerizable monomer with a substrate, a simultaneous irradiation method of irradiating radiation in the presence of a substrate and a monomer, and after previously irradiating only the substrate with radiation, Although any of the pre-irradiation methods in which the monomer and the base material are brought into contact with each other are possible, the pre-irradiation method has a feature that a side reaction other than the graft polymerization is hardly generated.

In the graft polymerization, the method of contacting the substrate with the monomer includes a liquid phase polymerization method in which the substrate is brought into direct contact with a liquid monomer or a monomer solution, and a gas phase in which the monomer is brought into contact with a vapor or a vaporized state. There is a graft polymerization method, and any method can be selected according to the purpose.

Hereinafter, the configuration and effects of the present invention will be specifically described with reference to examples, but none of the examples will limit the present invention.

[Examples] Example 1 An electron beam accelerator (acceleration voltage 2M)
After irradiating 200 KGy under a nitrogen atmosphere using eV and an electron beam current of 1 mA), it was brought into contact with glycidyl methacrylate vapor at 40 ° C. for 6 hours under reduced pressure to carry out a gas phase graft polymerization reaction. At this time, the weight increase rate was 130%. Of sodium iminodiacetate adjusted to pH 12 with sodium carbonate
The graft resin was immersed in a 0.4 mol / water solution and reacted at 80 ° C. for 24 hours. As a result, a chelate resin having an iminodiacetic acid group content of 2 mmol per 1 g of the base material was obtained. 1 g of this resin was filled in a 10 mmφ glass column, and 1 ppm of cobalt chloride aqueous solution was added.
SV = 10 hr ^-1 flow through the column, the effluent from the column
As a result of fractionating 50 ml each, the cobalt concentration in the effluent was 0.01 ppm or less even in the 50 fractionation. The chelating resin having an iminodiacetic acid group obtained a clearly superior result with respect to the cobalt ion.

Example 2 Glycidyl methacrylate was grafted on the basis of powdered polyethylene in the same manner as in Example 1 to obtain a graft resin powder having a graft ratio of 100%. An iminodiacetic acid group was immobilized thereon in the same manner as in Example 1 to obtain a chelate resin having an iminodiacetic acid group content of 1.5 mmol per 1 g of the base material. 1 g of this resin was packed in a 10 mmφ glass column, and a 1 ppm aqueous cupric sulfate solution was allowed to flow at a flow rate of SV = 10 hr ⁻¹ . At this time, the copper concentration in the effluent was 0.02 ppm even after 20 hours, indicating high adsorption performance for copper ions.

Example 3 Using a polypropylene filter cloth as a base material, a graft polymerization reaction and immobilization reaction of iminodiacetic acid groups were carried out in the same manner as in Example 1, and as a result, the graft ratio was 110% and the amount of iminodiacetic acid groups was 1.5 g / g of the base material. mmol chelate resin was obtained. Using this as a filter cloth having a diameter of 30 mm, a 1 ppm nickel chloride aqueous solution was added to 1.
(5) The nickel concentration of the permeate after filtration was 0.02 ppm or less, and nickel also exhibited excellent adsorption performance.

[Effects of the Invention] According to the present invention, it is possible to provide a material that exhibits high adsorption performance for heavy metal ions in an aqueous solution and is useful in various fields such as precision electronics, medicine, pharmaceuticals, and nuclear power generation.

Continuation of the front page (56) References JP-A-48-47987 (JP, A) JP-A-48-47985 (JP, A) JP-A-58-205544 (JP, A) JP-A-50-115277 (JP) , A) (58) Field surveyed (Int. Cl. ⁶ , DB name) B01J 20/00-20/34

Claims (3)

(57) [Claims] Claims: 1. A polymer molded article whose base material comprises a polymer or copolymer of an olefin or a halogenated olefin is subjected to ionizing radiation to graft-polymerize a polymerizable monomer containing an epoxy group. Production of chelating resin adsorbents with iminodiacetic acid groups that can remove and separate trace amounts of heavy metal components from aqueous solutions by reacting and immobilizing iminodiacetic acid groups on the epoxy groups of the graft-polymerized monomer side chains Method. 2. The method according to claim 1, wherein glycidyl methacrylate, glycidyl acrylate, glycidyl sorbate, glycidyl methitaconate, ethyl glycidyl maleate or glycidyl vinyl sulfonate is used as the polymerizable monomer having an epoxy group. the method of. 3. The polymer or copolymer of an olefin or a halogenated olefin is polysulfone or a homo- or copolymer of ethylene, propylene, butene, hexene, tetrafluoroethylene or chlorotrifluoroethylene. 2. The method according to 1.