Patent ID: 11498050

Abstract:
A method of preparing a superabsorbent polymer, which enables the preparation of the superabsorbent polymer exhibiting an improved absorption rate while maintaining excellent absorption performances is provided. The method of preparing the superabsorbent polymer includes carrying out a crosslinking polymerization of a water-soluble ethylene-based unsaturated monomer having acidic groups which are at least partially neutralized, in the presence of an internal crosslinking agent having a predetermined chemical structure to form a water-containing gel polymer, gel-pulverizing the water-containing gel polymer, drying, pulverizing, and size-sorting the gel-pulverized water-containing gel polymer to form a base polymer powder, and carrying out a surface crosslinking of the base polymer powder by a heat treatment in the presence of a surface crosslinking agent, wherein the gel-pulverizing is carried out by extruding the water-containing gel polymer through a porous plate having a plurality of holes using a screw extruder mounted inside a cylindrical pulverizer under a condition that a chopping index is 28 (/s) or more.