PROCESS FOR PRODUCTION OF WATER-ABSORBABLE RESIN

摘要

The present application provides: a process for producing a water-absorbable resin by a reversed-phase suspension polymerization method comprising at least two stages, whereby the odor originated from a raw material component, particularly a petroleum hydrocarbon dispersion medium, in the resin can be further reduced compared with those in water-absorbable resins produced by conventional techniques; and a water-absorbable resin produced by the process. More specifically, the present application provides: a process for producing a water-absorbable resin by a reversed-phase suspension polymerization method comprising at least two stages, which is characterized in that a first polymerization stage in the reversed-phase suspension polymerization comprising the at least two stages comprises (A) agitating/mixing an aqueous water-soluble ethylenically unsaturated monomer solution containing a hydrophilic polymeric dispersant with a petroleum hydrocarbon dispersion medium having a hydrophobic polymeric dispersant dissolved or dispersed therein in the absence of any surfactant to cause primary dispersion, (B) adding a surfactant to the resulting dispersion to cause secondary dispersion, and (C) carrying out polymerization using a water-soluble radical polymerization initiator to yield the water-soluble resin in the form of particles of a hydrogel dispersed in the petroleum hydrocarbon dispersion medium; and a water-absorbable resin produced by the process.