Pretreated cation-exchange resin, treation method of the resin, and mixed bed with cation-exchange resin
View Patent ↗The present invention provides cationic exchange resin that maintains a high exchange speed of polyvalent ions in addition to monovalent ions without agglomeration occurring in spite of surface coating even when mixed bed ion-exchange resin is used.
1. A mixed bed ion-exchange resin comprising a cationic exchange resin and an anionic exchange resin, wherein said cationic exchange resin has been treated by a water-soluble cationic polymer electrolyte, and wherein said water-soluble cationic polymer electrolyte contains an intramolecular cyclic quaternary ammonium salt structure.
2. The mixed bed ion-exchange resin of claim 1 in which the surface of the anionic exchange resin is untreated.
3. The mixed bed ion-exchange resin of claim 1 , wherein said water-soluble cationic polymer electrolyte consists of structural units having intramolecular cyclic quaternary ammonium salt structures.
4. The mixed bed ion-exchange resin of claim 1 , wherein said water-soluble cationic polymer electrolyte is a homopolymer selected from the group consisting of polydiallyl dimethyl ammonium chloride, polydiallyl diethyl ammonium chloride, polydiallyl dimethyl ammonium bromide, and polydiallyl dimethyl ammonium hydroxide.
5. The mixed bed ion-exchange resin of claim 1 , wherein said water-soluble cationic polymer electrolyte contains structural units of structure (1):
wherein R1 and R2 are independently alkyl groups having 1 to 10 carbon atoms, and wherein each R3 is an alkylene group having 1 to 5 carbon atoms, and wherein X is selected from the group consisting of chlorine, bromine, iodine, and OH.
6. The mixed bed ion-exchange resin of claim 1 , wherein said water-soluble cationic polymer electrolyte consists of structural units of said structure (1).
7. The mixed bed ion-exchange resin of claim 1 , wherein said cationic exchange resin is a strongly acidic cationic exchange resin.
8. The mixed bed ion-exchange resin of claim 1 , wherein said water-soluble cationic polymer electrolyte is present in an amount of 10 to 500 mg per liter of said cationic exchange resin.
9. The mixed bed ion-exchange resin of claim 1 , wherein said cationic exchange resin is present as polymer beads having a mean volume particle diameter of 0.15 to 1.0 mm.
10. The mixed bed ion-exchange resin of claim 1 , wherein said cationic polymer electrolyte has number average molecular weight of 80,000 to 200,000.