Method for Producing Water-Absorbing Polymer Particles by Suspension Polymerization

摘要

A process for producing water-absorbing polymer particles by suspension polymerization and thermal surface postcrosslinking, wherein the base polymer obtained by suspension polymerization has a centrifuge retention capacity of at least 37 g/g and the thermal surface postcrosslinking is conducted at 100 to 190° C.

主权项

1. A process for producing water-absorbing polymer particles by polymerizing a monomer solution comprising
a) at least one ethylenically unsaturated monomer which bears an acid group and optionally at least partly neutralized, b) optionally one or more crosslinker, c) at least one initiator, d) optionally one or more ethylenically unsaturated monomer copolymerizable with the monomer mentioned under a) and e) optionally one or more water-soluble polymer, the monomer solution being suspended in a hydrophobic organic solvent during the polymerization, and thermally surface postcrosslinking the resultant polymer particles using an organic surface postcrosslinker, wherein the amount of crosslinker b) is selected such that the polymer particles before the surface postcrosslinking have a centrifuge retention capacity of at least 37 g/g and the thermal surface postcrosslinking is conducted at 100 to 190° C.