Patent ID: 8513364
Filing Date: 2013-08-20
Classification: B01J,C08F

Abstract:
1. A production method of a water-absorbent resin, including the steps of: obtaining a hydrogel by supplying monomer liquid to a reaction device so that the monomer liquid is polymerized; and detaching the hydrogel from the reaction device, said method comprising the step of using, as the reaction device, a device whose surface in contact with the monomer liquid at a position where polymerization occurs is made of a fluororesin having a melt viscosity of 1×10 2 poise to 1×10 5 poise at 380° C., wherein said fluororesin is selected from the group consisting of a tetrafluoroethylene / perfluoroalkylvinylether copolymer (PFA), tetrafluoroethylene/hexafluoropropylene copolymer (FEP), tetrafluoroethylene ethylene copolymer (ETFE), polychlorotrifluoroethylene (PCTFE), chlorotrifluoroethylendethylene copolymer (ECTFE), polyvinylidenfluoride (PVDF), and polyvinylfluoride (PVF), wherein a roughness of the surface in contact with the monomer liquid is Rz 1.0 μm[□m] or less, and wherein an oxygen content in the reaction device at the time of polymerization of the monomer liquid, ranges from 5.0% by volume to an atmospheric concentration.