GB1055188A - Preparation of ion exchange resins - Google Patents

Abstract

Ion exchange resins are produced by chemically bonding ion active groups to the aromatic nuclei of a cross-linked vinyl aromatic polymer by contacting the polymer, which contains 0.5-1.25 substituent groups per aromatic nucleus consisting of 0.05-0.45 quaternary ammonium, sulphonium, sulphonic or phosphonic groups and 0.45-1.20 halomethyl groups, with a reagent to replace halogen atoms in all the halomethyl groups with ion active groups, the reagent being sodium or potassium cyanide, potassium thiocyanate, ammonium or sodium sulphite, sodium acetoacetate or malononitrile, primary and secondary organic amines, amino acids and their water-soluble salts, e.g. sodium imino diacetate, thioacids, e.g. mercapto succinic acid, and their water-soluble salts, amino-nitriles or tertiary amines, e.g. diethylene triamine. The resin may be produced by halomethylating the cross-linked polymer which contains the quaternary ammonium, sulphonium, sulphonic or phosphonic acid groups and then contacting the polymer with the above halogen-displacing reagent in the presence of a solvent, e.g. water, a C1- 8 alcohol, a C4- 10 polymeric ethylene or propylene glycol or a C1- 3 mono-alkyl ester of a C2- 8 polyhydric alcohol. In Examples (1) a styrene-divinylbenzene polymer is chloromethylated with chloromethyl ether, quaternized with dimethylamino-ethanol and aminated with sodium imino-diacetate; (2) the foregoing quaternary ammonium polymer is treated with the above halogen-displacing reagents; (3) the foregoing chloromethylated polymer is (A) treated with dimethyl sulphide and then sodium imino-diacetate to produce a sulphonium polymer; or (B) quaternized with trimethylamine and then treated with sodium imino-diacetate; (4) a styrene-divinylbenzene polymer is treated with chlorosulphonic acid, then with chloromethyl methyl ether and zinc chloride, and then sodium imino-diacetate to produce a sulphonic acid polymer.