Process for the preparation of carboxyl-containing polymers in an anionic form in the dry state; interpolymers thus obtained.

摘要

Carboxyl containing polymers in the neutralized ionic form, of acrylic, methacrylic or maleic acid anhydrides, usually copolymerized with esters, amides or nitriles, and optionally with cross-linking agents, are polymerized in non-aqueous systems in solvents for the monomers which are non-solvents for the resulting copolymers and the acid containing hydrophilic polymers thus obtained are neutralized to form an ionic salt, as with an alkali base such as NaOH dissolved or suspended in aliphatic alcohols containing less than 5 carbon atoms. By this technique the neutralization is conducted in the polymerization medium without isolating the free acid copolymers and a resulting slurry of uniform fine powder particles which are readily separated is obtained.