Patent ID: 11969707
Assignee: LG CHEM, LTD.
Field: Other special machines (Mechanical engineering)
Classification: CPC B  C | IPC B  C

Claim 0:
1. A method for preparing a super absorbent polymer comprising:
performing crosslinking polymerization of a water-soluble ethylenically unsaturated monomer having an acidic group of which at least a part is neutralized, in the presence of an internal crosslinking agent and a polymerization initiator to form a hydrogel polymer containing a first erosslinked polymer;
drying the hydrogel polymer so that a water content of the polymer is 2 to 10 wt %; and
pulverizing the dried polymer to prepare particles,
wherein the internal crosslinking agent is used in an amount of 500 to 2500 ppmw based on a weight of the water-soluble ethylenically unsaturated monomer having an acidic group of which at least a part is neutralized,
wherein the crosslinking polymerization is performed in the presence of a foaming agent, and
wherein the foaming agent is an encapsulated foaming agent, which has a structure including a core containing hydrocarbon and a shell surrounding the core and formed of a thermoplastic resin.