Patent ID: 9233186
Filing Date: 2016-01-12
CPC Classification: A61L,B01J,C08F,C08J

Claim Text:
1. A process for producing a water-absorbing resin comprising a polymerization step of polymerizing an aqueous unsaturated monomer solution, a drying step of drying a particulated water-containing gel-like crosslinked polymer obtained in a finely crushing step during the polymerization or after the polymerization, a pulverizing step after the drying, a classification step after the drying, and a surface treatment step for the water-absorbing resin powder after the classification step, wherein the surface treatment step is a heating treatment step by using a heating treatment apparatus, and where the surface treatment step is continuous treatment where the water-absorbing resin is continuously charged to and continuously discharged out of the heating treatment apparatus and an operation time of the continuous treatment step is not shorter than 24 hours, the surface treatment step is interrupted while the heating treatment apparatus is kept in a heated state and thereafter the surface treatment step is restarted, and the interruption time of the surface treatment step is not shorter than 0.5 hours and within 100 days, the interruption of the surface treatment step means a state where the water-absorbing resin powder is absent in the heating treatment apparatus, or not charged to or not discharged out of the heating treatment apparatus in the surface treatment, and a state not charged to or not discharged out of an apparatus means a state where a water-absorbing resin powder is stopped in an apparatus and a state where the apparatus is stopped.