Method of producing ion exchange resins having a sponge structure

Ion exchange resins having a sponge structure are produced by a method wherein one or more monovinyl aromatic compounds and one or more polyvinyl compounds are copolymerized in the presence of substances which dissolve in the monomer mixture but in which the resulting aromatic vinyl polymers are practically neither soluble nor swellable, and in the presence of 0.1% to 20% by weight referred to the monomer mixture, of one or more polar compounds containing vinyl and/or epoxy groups, followed by the subsequent introduction of groups having ion exchange activity. As monovinyl aromatic substances there may be used styrene, vinyl toluene, vinyl ethyl benzene, vinyl anisole, acenaphthylene and vinyl napthalene. Examples of polyvinyl compounds are divinyl benzene, divinyl ethyl benzene, trivinylbenzene, divinyl acetylene, butadiene, ethylene glycol dimethacrylate, divinyl ketone, divinyl sulphone, oxalic acid divinyl ester, divinyl ether and methacrylic acid vinyl ester. Suitable non-solvents are benzine (b.p. 100-140 DEG C.), white spirit (bp. 160-190 DEG C.), titralin, decalin, cyclohexane, butanol, amyl alcohol, dodecanol, cyclohexanol, diphenyl ether, dihexyl ether, 2-ethylhexyl acetate, dodecylpropionate, nitromethane, linear polystyrene and linear polyvinyltoluene. Polar compounds containing vinyl groups may be acrylic acid and its derivatives, methacrylic acid and its derivatives, methyl vinyl ketone, vinyl halides, vinyl benzyl halides, methyl vinyl ether, vinyl pyridine, esters of vinyl alcohol such as vinyl acetate and vinyl propionate and maleic acid and its derivatives. Those containing epoxy groups may be styrene oxide, vinyl toluene oxide, ethyl styrene oxide, phenyl glycide ether, divinyl benzene dioxide and epichlorohydrin. The introduction of groups having ion exchange activity may be effected by halogen alkylation and amination, nitration and reduction, sulphonation, halogenation with a phosphorus halide followed by saponification and oxidation, halogen alkylation followed by reaction with trialkyl phosphites and saponification.