| 主权项 |
1. A method for preparing a superabsorbent polymer resin, comprising:
a) preparing a hydrogel phase polymer by thermal- or photo-polymerizing a composition comprising a water-soluble ethylene-based unsaturated monomer and a polymerization initiator; b) drying the hydrogel phase polymer; c) milling the dried polymer; d) classifying the milled hydrogel phase polymer by particle size into particles with sizes of less than 150 μm, from 150 μm to less than 300 μm, from 300 μm to less than 450 μm, from 450 μm to less than 600 μm, and from 600 μm to 850 μm; e) blending normal particles which is mixed with particles with sizes of from 600 μm to 850 μm, from 300 μm to less than 600 μm, and from 150 μm to less than 300 μm with agglomerated particles with a size of 450 μm or less; f) adding a surface crosslinking agent to the blended hydrogel phase polymers; and g) performing a surface cross-linking reaction on the hydrogel phase polymers, the particle blend of step e) containing particles with a size of 600˜850 μm in an amount of 0.01˜3 wt %, particles with a size of 300˜600 μm in an amount of 50˜80 wt %, and particles with a size of 150˜300 μm in an amount of 1˜25 wt %, and the agglomerated particles with a size of 450 μm or less in an amount of 15˜30 wt %, based on the total weight of the normal particles and the agglomerated particles. |
