Method for improved removal of cations using chelate resins

摘要

Preparing monodispersed ion exchanger (having chelating [(benzyl-phosphonomethyl-amino)-methyl]-phosphonic acid functional groups (I)) comprises: (a) converting monomer droplets of e.g. at least one monovinyl aromatic compounds, at least one polyvinylaromatic compounds, at least one porogen and at least one initiator to monodispersed crosslinked bead polymer; (b) phthalimidomethylating the polymer with phthalimide derivative; (c) converting phthalimidomethylated bead polymer to aminomethylated bead polymer; and (d) reacting aminomethylated bead polymer ion exchanger with chelating groups. Preparing monodispersed ion exchanger (having chelating [(benzyl-phosphonomethyl-amino)-methyl]-phosphonic acid functional groups of formula (I)) comprises: (a) converting monomer droplets of at least one monovinyl aromatic compounds, at least one polyvinylaromatic compounds, at least one porogen and at least one initiator or an initiator combination to a monodispersed crosslinked bead polymer according to jetting principle or seed-feed principle; (b) phthalimidomethylating the monodispersed crosslinked bead polymer with phthalimide derivative in which 1-15 wt.% of bead polymer is added to the sulfur trioxide adduct of the phthalimide derivative present in an inert solvent and stirring at a temperature of = 35[deg] C for 1-15 hours, where the amount of free sulfur trioxide is 0.28-0.5 mol relative to 1 mol of phthalimide and the balance amount of the bead polymer to the sulfur trioxide adduct of phthalimide derivative present in the inert solvent is added at 50-75[deg] C; (c) converting phthalimidomethylated bead polymer to aminomethylated bead polymer; and (d) reacting the aminomethylated bead polymer ion exchanger with chelating groups. A : polymer backbone. An independent claim is included for the above monodispersed ion exchanger whose total capacity is 3.1-3.9 mol/l and an average pore diameter of 70-85 nm. [Image].