Patent ID: 8357766

Claim:
A continuous process for the production of a superabsorbent polymer comprising: (a) providing an acidic liquid aqueous monomer mixture containing dissolved oxygen, whereby the monomers are selected to provide after polymerization a superabsorbent polymer, (b) continuously feeding said aqueous monomer mixture to a reactor, (c) introducing a source of carbonate or hydrogen carbonate into said aqueous monomer mixture prior to entry into the reactor thereby forming a dispersed gas phase comprising carbon dioxide and at least a part of said dissolved oxygen, said dispersed gas phase being dispersed in said aqueous monomer mixture wherein the source of carbonate or hydrogen carbonate is introduced in an amount to provide about 1 to about 15% of the total neutralization of the acidic functionality of the resultant superabsorbent polymer wherein the total neutralization is between about 50% and about 85%, (d) at least partially separating said dispersed gas phase from the aqueous monomer mixture to create a separated gas phase and a liquid phase immediately prior to or after entry into the reactor and at least partially removing the separated gas phase, (e) subjecting the liquid phase in the reactor to free-radical polymerization to obtain the superabsorbent polymer, and (f) continuously removing the superabsorbent polymer from the reactor.