Super absorbent polymer and method for producing same

A super absorbent polymer comprising:

• a base polymer powder including a first crosslinked polymer of a water-soluble ethylenically unsaturated monomer having at least partially neutralized acidic groups;
• and
• a surface crosslinked layer formed on the base polymer powder and including a second crosslinked polymer in which the first crosslinked polymer is further crosslinked via a surface crosslinking agent,
• wherein the super absorbent polymer has the following features:
• a fixed height absorption (FHA) (20 cm) for a physiological saline solution (0.9 wt % aqueous sodium chloride solution) of 22.5 g/g to 29 g/g,
• a centrifuge retention capacity (CRC) for a physiological saline solution (0.9 wt % aqueous sodium chloride solution) for 30 minutes of 26 g/g to 34 g/g,
• a saline flow conductivity (SFC) for a physiological saline solution (0.685 wt % aqueous sodium chloride solution) of 35 (·10−7 cm3·s/g) or more, and
• a free swell rate (FSR) of 0.25 g/g/s to 0.40 g/g/s when 1 g of the super absorbent polymer absorbs 20 g of a 0.9 wt % aqueous sodium chloride solution,
• wherein the first crosslinked polymer includes a polymer in which the water-soluble ethylenically unsaturated monomer is crosslinked in the presence of an internal crosslinking agent,
• the internal crosslinking agent includes a polyolpoly(meth)acrylate-based first internal crosslinking agent, and an allyl(meth)acrylate-based second internal crosslinking agent,
• the polyolpoly(meth)acrylate-based first internal crosslinking agent is included in an amount of 0.4 to 1 parts, and the allyl(meth)acrylate-based second internal crosslinking agent is included in an amount of 0.008 to 0.5 parts, by weight based on 100 parts by weight of a monomer composition including the internal crosslinking agent and the water-soluble ethylenically unsaturated monomer, and
• the allyl(meth)acrylate-based second internal crosslinking agent is allyl acrylate or allyl (meth)acrylate.