Manufacturing method of super absorbent polymer
The present invention relates to a manufacturing method of a super absorbent polymer. More specifically, the present invention relates to a manufacturing method of a super absorbent polymer capable of reducing energy, reducing a process cost, and reducing a load on a device, at the time of drying due to reduction in an amount of water used during reassembly of fines, while manufacturing a super absorbent polymer exhibiting a reduced generation amount of re-fines and having excellent physical properties.
1. A manufacturing method of a super absorbent polymer comprising:
preparing a hydrogel polymer by performing thermal polymerization or photopolymerization on a monomer composition including a water-soluble ethylenically unsaturated monomer and a polymerization initiator;
drying and pulverizing the hydrogel polymer, and performing classification into fines having a particle diameter of 150 μm or less and normal particles having a particle diameter of more than 150 μm to 850 μm or less;
manufacturing a fine reassembly by mixing the fines with water, followed by reassembling; and
manufacturing an extruded fine reassembly by extruding, pulverizing, and classifying the fine reassembly,
wherein in the manufacturing of the fine reassembly, 1 to 30 parts by weight of water is used based on 100 parts by weight of the fines, and
the manufacturing of the extruded fine reassembly includes extruding the fine reassembly at a temperature of 40 to 105° C.
2. The manufacturing method of claim 1 , wherein:
the extruding is performed in a chopper that extrudes and cuts the fine reassembly.
3. The manufacturing method of claim 1 , wherein:
the manufacturing of the fine reassembly includes mixing the fines and the water in a mixing device capable of applying a shear force.
4. The manufacturing method of claim 3 , wherein:
in the manufacturing of the fine reassembly, the fines and the water are mixed with stirring at 300 to 2000 rpm.
5. The manufacturing method of claim 1 , wherein:
the manufacturing of the extruded fine reassembly is performed in an extruder equipped with a cutter which extrudes and cuts the fine reassembly.
6. The manufacturing method of claim 1 , wherein:
the manufacturing of the extruded fine reassembly further includes drying between the extruding and the pulverizing.
7. The manufacturing method of claim 6 , wherein:
the drying is performed at 120 to 220° C.
8. The manufacturing method of claim 1 , wherein:
the manufacturing of the extruded fine reassembly includes classifying the extruded and pulverized fine reassembly into reassembly fines having a particle diameter of 150 μm or less and reassembly normal particles having a particle diameter of more than 150 μm to 850 μm or less.
9. The manufacturing method of claim 1 , wherein:
in an extruded fine reassembly having a particle diameter of 300 to 600 μm, a centrifugal retention capacity (CRC) measured according to EDANA method WSP 241.3 is 33.0 to 45.0 g/g, and an absorption speed by a vortex method is 50 seconds or less.
10. The manufacturing method of claim 1 , further comprising:
surface cross-linking the extruded fine reassembly.