| abstract |
The invention relates to a process for preparing anion exchangers based on crosslinked, water-insoluble organic polymers containing aromatic nuclei, in which, in the first step, N-hydroxymethylphthalimide is produced by reaction of phthalimide with aqueous formaldehyde solution in swelling agents in the presence of bases; if desired, this N-hydroxymethylphthalimide is converted in a 2nd step to the bis)phthalimidomethyl)ether or an ester of N-hydroxymethylphthalimide; said polymers are aminomethylated wtih N-hydroxy-methylphthalimide, bis)phthalimidomethyl) ether or an ester of N-hydroxymethylphthalimide in the presence of Friedel-Craft catalysts and swelling agents and the amidomethylated polymers are finally saponified to form the aminomethylated polymers, wherein, in the first reaction step, the base used for producing N-hy-droxymethylphthalimide is sodium hydroxide solution and this sodium hydroxide solution is added in such an amount and at such a rate that the reaction of phthalimide with formaldehyde takes place in the pH range of 5 to 6. |