Patent ID: 8829107

Claim:
A method for the production of a superabsorbent composition comprising the process steps: i. producing a hydrogel by radical polymerization of an aqueous monomer solution containing an ethylenically unsaturated acid-group-containing monomer including acrylic acid and methacrylic acid and a crosslinking agent, wherein the monomer solution has a monomer content in the range from 20 to 30%; ii. drying the hydrogel to obtain a water-absorbing polymer structure; iii. surface post-crosslinking of the water-absorbing polymer structure with a post-crosslinking agent to obtain a surface-crosslinked water-absorbing polymer structure; iv. incorporating from about 5 wt % to 20 wt % of a water-soluble powder starch compound based on the weight of the superabsorbent composition wherein the powder starch compound is water-soluble if at least about 30 g of powder starch compound may be dissolved in a liter of deionized water at a temperature of 20° C., in at least two of the following variants V2. after process step i. and prior to process step ii. into the hydrogel V3. in process step ii V5. in process step iii wherein the starch compound comprises less than about 20% amylose and is more than about 75% carboxymethylated, and wherein the starch compound has a weight average particle size from 20 to 80 μm, and less than 10 wt % of the particles having a particle size of less than about 5 μm and less than 10 wt % of the particles having a particle size of more than about 90 μm wherein the superabsorbent composition has the following properties: Z1 a retention (CRC) of from about 25 g/g to 35.1 g/g, Z2 an absorption at pressure (AAP 0.7 ) of from about 15 g/g to 25.3 g/g, Z3 a permeability (SFC) of from about 20×10 −7 cm 3 sec/g to 29.2×10 −7 cm 3 sec/g, and Z4 a biodegradability determined according to the method described herein after 28 days of from about 25% to 39%.