The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 21, 2013
Filed:
Nov. 05, 2012
Torsten Balduf, Pfungstadt, DE;
Gunther Bub, Marl, DE;
Jurgen Mosler, Castrop-Rauxel, DE;
Andreas Sabbagh, Dulmen, DE;
Jurgen Kohn, Rheinberg, DE;
Arndt Selbach, Dirmstein, DE;
Torsten Balduf, Pfungstadt, DE;
Gunther Bub, Marl, DE;
Jurgen Mosler, Castrop-Rauxel, DE;
Andreas Sabbagh, Dulmen, DE;
Jurgen Kohn, Rheinberg, DE;
Arndt Selbach, Dirmstein, DE;
Evonik Degussa GmbH, Essen, DE;
Abstract
The invention relates to producing a superabsorbent polymer comprising (I) producing a (meth)acrylic acid comprising the steps of (a) synthesizing a crude (meth)acrylic acid phase; (b) distillatively working-up the crude (meth)acrylic acid phase to obtain a (meth)acrylic acid phase and a dimer phase comprising (meth)acrylic acid dimers and/or (meth)acrylic acid oligomers; (c) splitting at least a part of the (meth)acrylic acid dimers or of the (meth)acrylic acid oligomers or both from the dimer phase to obtain a (meth)acrylic acid-comprising a low boiling phase and a high boiling phase comprising less (meth)acrylic acid than the low boiling phase; (d) separating at least a part of the (meth)acrylic acid from the low boiling phase by forming crystals to obtain a pure (meth)acrylic acid, and a residue; (II) polymerizing a monomer phase comprising the pure (meth)acrylic acid to obtain a polymer phase; and (III) working-up the polymer phase to obtain the polymer.