Continuous process for the production of a superabsorbent polymer

US8357766B2 · kind B2 · utility

Assignee

• Evonik Stockhausen GmbH · US

Inventors

• Daniel Fricker · Rœschwoog, FR
• Herbert Gartner · Baden-Baden, DE
• Marc Hager · Bischwiller, FR
• Jorg Harren · Baesweiler, DE
• Hans-Peter Kohler · Bühlertal, DE
• Harald Plochinger · Bühl, DE

Key dates

• Filing date: Oct 7, 2009
• Grant date: Jan 22, 2013
• Expiry date: Jul 23, 2031

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08F2/16
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

The present invention relates to a continuous process for the production of a superabsorbent polymer comprising providing an acidic liquid aqueous monomer mixture containing dissolved oxygen; continuously feeding the aqueous monomer mixture to a reactor; introducing a source of carbonate or hydrogen carbonate into the aqueous monomer mixture prior to entry into the reactor thereby forming a gas phase comprising carbon dioxide and at least a part of the dissolved oxygen, the gas phase being dispersed in the liquid phase; subjecting the gas/liquid mixture to at least partial phase separation immediately prior to or after entry into the reactor and at least partially removing the separated gaseous phase; subjecting the liquid phase in the reactor to free-radical polymerization to obtain the superabsorbent polymer, and continuously removing the superabsorbent polymer from the reactor.