| 主权项 |
1. A process for producing water-absorbing polymer particles by polymerising a foamed aqueous monomer solution or suspension comprising
a) at least one ethylenically unsaturated monomer which bears an acid group and has been neutralised to an extent of 25 to 95 mol %, b) at least one crosslinker, c) at least one initiator, d) optionally at least one surfactant, e) optionally one or more ethylenically unsaturated monomer copolymerisable with the monomer mentioned under a), f) optionally a solubiliser, and g) optionally thickeners, foam stabilisers, polymerisation regulators, fillers, fibres and/or cell nucleators, the monomer solution or suspension being polymerised to a polymeric foam that is dried, subsequently ground and classified, the process further comprising i) spray-coating the water-absorbing polymeric particles with an elastic film-forming polymer in a fluidised bed reactor in the range from 0° C. to 50° C., and ii) heat-treating the coated particles at a temperature above 50° C. |
