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:
Jun. 21, 2011
Filed:
Sep. 13, 2010
Stefan Nordhoff, Recklinghausen, DE;
Axel Kobus, Bochum, DE;
Stefan Gross, Langenselbold, DE;
Hans-rolf Lausch, Alzenau, DE;
Torsten Balduf, Marl, DE;
Roland Fornika, Marl, DE;
Guenther Bub, Marl, DE;
Stefan Nordhoff, Recklinghausen, DE;
Axel Kobus, Bochum, DE;
Stefan Gross, Langenselbold, DE;
Hans-Rolf Lausch, Alzenau, DE;
Torsten Balduf, Marl, DE;
Roland Fornika, Marl, DE;
Guenther Bub, Marl, DE;
Evonik Stockhausen GmbH, Krefeld, DE;
Abstract
The invention relates to a superabsorbent polymer that includes a (meth)acrylic acid made by a process that comprises the following process steps: a) (meth)acrylic acid is crystallized out from a mother liquor; b) crystallized (meth)acrylic acid is separated from the mother liquor; c) at least part of the separated (meth)acrylic acid crystals are melted; d) the melted part is at least partially recycled to the step a) or step b). The superabsorbent polymer according to the present invention includes an process to make (meth)acrylic acid, the apparatus suitable for implementing the process, and the use of the apparatus for the production of (meth)acrylic acid characterized by a high purity of the thereby obtainable (meth)acrylic acid as well as by a high efficiency with regard to the achievable yield and necessary energy requirement, thereby providing an improved superabsorbent polymer.