PREPARATION OF ION EXCHANGE RESIN

摘要

The invention relates to a process for the manufacture of ion exchange resins containing aminomethylenephosphonic acid groups by reacting macroporous aminomethylated crosslinked vinylaromatic resins with formaldehyde and phosphorus(III) compounds in aqueous mineral acids; it is characterised in that sulphuric acid is used as mineral acid and the latter is employed in an amount such that its concentration is at least 20% by weight based on the weight of the liquid phase of the reaction mixture.