Patent ID: 8445617

Claim:
A superabsorbent polymer made by the process comprising the steps of: I. a) producing crude (meth)acrylic acid phase wherein crude (meth)acrylic acid comprises from about 1 to about 80 wt % of (meth)acrylic acid; wherein said producing crude (meth)acrylic acid phase is selected from the group consisting of gas phase oxidation, and dehydration of an organic molecule having at least one OH-group wherein the organic molecule is selected from the group consisting of glycerine, lactic acid and β-hydroxypropionic acid; b) distilling the (meth)acrylic acid phase of a) to obtain a (meth)acrylic acid phase, and a dimer phase comprising (meth)acrylic acid dimers or (meth)acrylic acid oligomers or both; 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 low boiling phase, and a high boiling phase comprising less (meth)acrylic acid than the low boiling phase, wherein said high boiling phase is discarded; d) separating at least a part of the (meth)acrylic acid from the low boiling phase by forming one or more crystals to obtain a pure (meth)acrylic acid and a residue; II. polymerizing the pure (meth)acrylic acid in the presence of a cross linker to obtain a superabsorber polymer phase; and III. working-up the polymer phase to obtain the superabsorber polymer.