Polyhydroxy materials containing ionexchange groups and non-ionic substituents and their method of preparation

Claim 1

A METHOD OF PREPARING A WATER INSOLUBLE DERIVATIVE OF A POLYHYDROXY MATERIAL SELECTED FROM THE GROUP CONSISTING OF CELLULOSE, POLYVINYL ALCOHOL AND STARCH, CONTAINING A CELLULOSE, POLYVINYL ALCOHOL AND STARCH, CONTAINING ION-EXCHANGE GROUPS, WHICH METHOD COMPRISES INTRODUCING INTO A POLYHYDROXY MATERIAL ION-EXCHANGE GROUPS WHICH RENDER THE PRODUCT CAPABLE OF UNDERTAKING REVERSIBLE EXCHANGE OF IONS IN AQUEOUS SOLUTION, MIXING WITH THE POLYHYDROXY MATERIAL A MONOFUNCTIONAL REAGENT, CAPABLE OF SUBSTITUTING FOR THE HYDROXYL GROUPS OF THE MATERIAL NONIONIC SUBSTITUENT GROUPS WHICH ARE ATTACHED TO THE POLYHYDROXY MATERIAL BY ONE LINKAGE ONLY, AND OF THEREBY INDUCING SELECTIVE INTERACTION EFFECTS BETWEEN THE THUS MODIFIED MATRIX AND AN EXCHANGING ION, EFFECTING SAID SUBSTITUTION REACTION BETWEEN SAID POLYHYDROXY MATERIAL AND SAID REAGENT AND RECOVERING THE RESULTING PRODUCT, THEREBY PRODUCING A MATERIAL WHOSE ION-EXCHANGE PROPERTIES ARE SUBSTANTIALLY DIFFERENT FROM THOSE OF A CORRESPONDING IONEXCHANGE MAERIAL HAVING NO NON-IONIC SUBSTITUENT GROUPS.