Process for reducing the content of water-soluble salts of aqueous solutions of polymers containing vinylamine groups and use of the desalted polymers in the manufacture of multicomponent superabsorbent gels

摘要

Process for reducing the content of water-soluble salts of aqueous solutions of polymers containing vinylamine groups by ultrafiltration to achieve a residual salt content of 1 to 10% by weight based on total solution solids in the polymer solution comprising feeding an aqueous salt-containing solution of vinylamine group containing polymers at a polymer concentration of at least 7% by weight to an ultrafiltration unit and removing the water-soluble salts with the permeate from the feed solution by adding thereto less than 4 parts by weight of water per one part by weight of the feed solution, and use of the polymer of the aqueous solutions thus purified as basic water-absorbing resin of multicomponent superabsorbent polymers. Preferably vibratory shear membranes in a diafiltration configuration are used.