Method of preparing superabsorbent polymer
AssigneeLG Chem, Ltd.
InventorsJinuk Choi, Yesol Yang, Sanghwa Lee, Gicheul Kim, Ki Hyun Kim, Seul Ah Lee
Life of this patent
Estimating the term…
Abstract
A method of preparing a superabsorbent polymer having a rapid absorption rate and an improved water retention capacity by additional heat treatment while using a thermally degradable internal crosslinking agent and an encapsulated foaming agent at the same time during polymerization. A superabsorbent polymer prepared by this method is also provided, the superabsorbent polymer having a centrifuge retention capacity (CRC) of 40 g/g to 55 g/g, as measured according to EDANA method WSP 241.3, and an absorption rate of 48 sec or less, as measured by a vortex method.
Claims11
A method of preparing a superabsorbent polymer, the method comprising:
- forming a water-containing gel polymer by performing crosslinking polymerization of water-soluble ethylenically unsaturated monomers having acidic groups, of which at least part is neutralized, in the presence of an internal crosslinking agent including a compound represented by the following Chemical Formula 1, an encapsulated foaming agent, and a polymerization initiator;
- forming a base polymer in the form of powder by drying and pulverizing the water-containing gel polymer;
- and
- performing heat-treatment of only the base polymer,
- wherein the encapsulated foaming agent is used in an amount of 0.1 part by weight to 0.4 parts by weight with respect to 100 parts by weight of the water-soluble ethylenically unsaturated monomer:
- in Chemical Formula 1, R1 is a divalent organic group derived from alkane having 1 to 10 carbon atoms, and R2 is hydrogen or a methyl group.
Dependencies are inferred from the claim text.