| abstract |
SUBSTANCE: invention relates to powdered, crosslinked, water-absorbing and aqueous liquids, called superabsorbers, polymers. A powdery, insoluble, water-swellable, crosslinked, water-absorbing, aqueous or serous liquid polymerizate, formed from: a) 55-99.9 wt. % polymerized, unsaturated, containing acidic groups, polymerizable monomers, which are at least 25 mol. % neutralized; b) up to 40 wt. % polymerized, unsaturated, copolymerizable with a) monomers; s) 0.1-5.0 wt. % crosslinking agent and e) up to 30 wt. % of a water-soluble polymer, while the weight amounts from a) to e) are given in terms of the anhydrous polymer and the polymer powder is heated to 150-250 ° C, with at least one compound with two functional groups reactive towards acid groups monomers, while surface crosslinking occurs. The polymerizate powder is once again processed and crosslinked at a temperature of 150-250 ° C with 0.1-5.0 wt. % of a compound with at least two functional groups reactive towards acidic groups. |