Patent ID: 9012356
Filing Date: 2015-04-21
Classification: A61L,C08F,C08J,C08L

Abstract:
1. A method for producing a polyacrylic acid (salt)-based water absorbent resin, the method comprising a polymerization step of supplying as a base material an aqueous solution containing an acrylic acid and/or an acrylic acid salt as a monomer component and polymerizing the monomer in the presence of a polymerization initiator, wherein in the polymerization step, there is used a polymerization apparatus which comprises a polymerization part covered with a case, said polymerization part comprising at least a supply line for supplying the aqueous solution, an external gas supply port, and a gas discharge port, and has a structure that a liquid contact part in contact with the aqueous solution and a gas supplied from the outside of the polymerization apparatus are brought into contact with the aqueous solution during a polymerization, and wherein a controlled temperature of the liquid contact part is set as TS, a temperature of the gas is set as TG, and TT is (TS+TG)/2, the polymerization is carried out under temperature conditions satisfying the following Equations 1 to 3