Preparation method for superabsorbent polymer
AssigneeLG Chem, Ltd.
InventorsTae Young Won, Jungmin Sohn, Hyemin Lee, Jihye Ryu
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Abstract
A method of preparing a superabsorbent polymer and the superabsorbent polymer maintaining excellent basic absorption performances such as centrifuge retention capacity, while exhibiting improved gel strength and absorption rate are provided. The nanocellulose fiber is introduced during the preparation of the superabsorbent polymer to improve mechanical strength, to form a porous structure, and to rapidly absorb the surrounding water through capillary action and delivering the water to the inside of the superabsorbent polymer.
Claims16
A method of preparing a superabsorbent polymer, comprising:
- a) mixing a water-soluble ethylene-based unsaturated monomer, an internal crosslinking agent, and a solvent to prepare a first monomer mixture;
- b) introducing a nanocellulose fiber having a width of 3 nm to 50 nm, a length of 1 μm to 5 μm, and a tensile strength of 2,000 MPa or more, and a surfactant while shear mixing the first monomer mixture to prepare a second monomer mixture;
- c) introducing a polymerization initiator to the second monomer mixture to prepare a third monomer mixture;
- d) polymerizing the third monomer mixture to prepare a water-containing gel polymer;
- e) chopping the water-containing gel polymer;
- f) drying, pulverizing, and size-sorting the water-containing gel polymer to prepare a base polymer;
- and
- g) carrying out an additional crosslinking of the surface of the base polymer in the presence of a surface crosslinking agent to form a surface-crosslinked layer and thereby produce the superabsorbent polymer,
- wherein the shear mixing of the first monomer mixture to prepare the second monomer mixture is performed at a shear rate of 6 s−1 or more.
A superabsorbent polymer having a gel strength of 10,000 Pa or more, comprising:
- base polymer particles including a crosslinked polymer which is obtained by crosslinking polymerization of a water-soluble ethylene-based unsaturated monomer in the presence of an internal crosslinking agent;
- a surface-crosslinked layer which is formed on the surface of the base polymer particles and is obtained by additional crosslinking of the crosslinked polymer via a surface crosslinking agent;
- and
- a nanocellulose fiber having a width of 3 nm to 50 nm, a length of 1 μm to 5 μm, and a tensile strength of 2,000 MPa or more, which is incorporated with the base polymer.
Dependencies are inferred from the claim text.