Application of diphosphonic derivatives to cation exchange, new diphosphonic derivatives, and production process therefor

摘要

A water insoluble ion exchange resin having a crosslinked, three dimensional resin skeleton and an active group of the formula: ##STR1## wherein R is selected from the group consisting of hydrogen and an alkyl radical having 1-15 carbon atoms and having at most two branchings in the alkyl group, and A is a mono-, di-, or tri-substituted ethylene radical or mono- or di-substituted methylene radical, wherein the substituents are selected from the group consisting of an alkyl group having at most two branchings, hydroxy, an amino group and hydrogen and wherein A provides a link binding the active group to the resin skeleton.