CATION EXCHANGE RESIN AND USE THEREOF

摘要

PURPOSE:To stably capture various cations by forming a cation exchange resin consisting of polyamido-carboxylic acid units represented by a specified general formula and polyimido units represented by a specified general formula. CONSTITUTION:A cation exchange resin proof against org. solvents is formed with a polyimide type resin consisting of polyamido-carboxylic acid units acting as ion exchange moieties and represented by formula I (where R<1> is a quatervalent org. group and R<2> is a bivalent org. group) and polyimido units represented by formula Il (where R<1> and R<2> are R<1> and R<2> in the formula I). The cation exchange resin is obtd. by dissolving nearly equimolar amts. of tetracarboxylic acid anhydride and diamine in a polar solvent, allowing them to react with each other at 20-100 deg.C for 30min-4hr, applying the resulting polyamido-carboxylic acid soln. and heating the applied soln. at a high temp.