GB767821A - Improvements in and relating to ion-exchange resins - Google Patents

Abstract

An insoluble ion-exchange resin derived from a copolymer of an aromatic monovinyl hydrocarbon, e.g. styrene, and an aromatic divinyl hydrocarbon, e.g. divinyl benzene, contains both organic acid groups and basic nitrogen groups attached to the same resin matrix. The organic acid group is preferably derived from acetic or diacetyl acetic acid. The resin may be produced by (1) condensing an amine derivative of the copolymer with a halogenated organic acid, e.g. chloracetic acid, or salt thereof to give a product containing imino groups, or (2) condensing such a copolymer containing reactive halogen groups with an acid containing imino groups, e.g. imino-diacetic acid, or with a derivative thereof, e.g. the dinitrile of iminodiacetic acid, followed by hydrolysis to liberate the acid groups, which results in a product containing t-amine groups. The halogen groups may be introduced into the copolymer as described in Specifications 654,706, 670,348 and 679,850-3, and for use in method (1) a resin containing halo-alkyl groups thus produced may then be aminated by reacting with (a) ammonia, an arylamine, an alkylamine, e.g. methylamine, ethylene diamine or a poly-primary amine, or (b) potassium phthalimide or a monophthalimido derivative of a diprimary amine, such as ethylene diamine, followed by hydrolysing off the phthalic acid structure. Additional basic nitrogen groups may then be introduced into the aminated copolymer by condensation with ethylene or polyethylene imine. The products serve either as cation- or anion-exchange resins and when the acidic and basic groups are separated by one or two carbon atoms they will form complexes with particular metallic ions, e.g. those of copper, nickel, cobalt, chromium or manganese. In examples, the copolymer of styrene and divinyl benzene is produced by heating with benzoyl peroxide catalyst in aqueous suspension using a cellulose derivative as stabilizer.