US 9,808,787 B2
Super absorbent polymer and preparation method thereof
Chul Hee Ryu, Daejeon (KR); and Hyemin Lee, Daejeon (KR)
Assigned to LG Chem, Ltd., (KR)
Filed by LG Chem, Ltd., Seoul (KR)
Filed on Oct. 6, 2016, as Appl. No. 15/286,764.
Application 15/286,764 is a division of application No. 14/879,304, filed on Oct. 9, 2015, granted, now 9,486,778.
Application 14/879,304 is a continuation in part of application No. PCT/KR2014/009117, filed on Sep. 29, 2014.
Claims priority of application No. 10-2013-0116682 (KR), filed on Sep. 30, 2013.
Prior Publication US 2017/0021334 A1, Jan. 26, 2017
Int. Cl. C08F 2/46 (2006.01); C08F 2/50 (2006.01); C08G 61/04 (2006.01); B01J 20/30 (2006.01); C08F 2/10 (2006.01); C08J 3/075 (2006.01); A61L 15/60 (2006.01); A61L 15/24 (2006.01); B01J 20/26 (2006.01); C08J 3/24 (2006.01); B01J 20/28 (2006.01); C08F 120/06 (2006.01); C08L 101/14 (2006.01)
CPC B01J 20/3085 (2013.01) [A61L 15/24 (2013.01); A61L 15/60 (2013.01); B01J 20/267 (2013.01); B01J 20/28016 (2013.01); B01J 20/30 (2013.01); B01J 20/3021 (2013.01); B01J 20/3028 (2013.01); B01J 20/3078 (2013.01); C08F 2/10 (2013.01); C08F 120/06 (2013.01); C08J 3/075 (2013.01); C08J 3/245 (2013.01); B01J 2220/68 (2013.01); C08J 2333/02 (2013.01); C08L 101/14 (2013.01)] 3 Claims
 
1. A preparation method of a super absorbent polymer, comprising:
heating or irradiating a monomer composition to form a hydrogel polymer by polymerization, wherein the monomer composition contains water-soluble ethylene-based unsaturated monomers and a polymerization initiator;
drying the hydrogel polymer;
pulverizing the dried polymer to form particles; and
heating a mixture of the particles and a surface crosslinking solution at a temperature ranging from about 180 to about 200° C. to form surface crosslinked polymer particles of the super absorbent polymer,
wherein the surface crosslinking solution contains a surface crosslinking agent and water,
wherein the super absorbent polymer includes a water-soluble component having a ratio (dwt/d(log M)) of 0.86 or less over an entire range of molecular weight ranging from 100,000 to 300,000 when measured from an eluted solution after swelling 1 g of the super absorbent polymer in 200 ml of 0.9% NaCl solution at 25° C. for 1 hour, and
wherein the water-soluble component is present in an amount of 5% by weight or less, based on the total weight of the super absorbent polymer, when measured from an eluted solution after swelling 1 g of the super absorbent polymer in 200 ml of 0.9% NaCl solution at 25° C. for 1 hour.