Process for producing water-absorbing resin

摘要

The disclosed process for producing a water-absorbing resin comprising: a polymerization step of polymerizing an aqueous unsaturated monomer; and a drying step of drying a particulated water-containing gel-liked crosslinked polymer, obtained in a finely crushing step during the polymerization or after the polymerization. In the process, the drying step is interrupted with a dryer kept in a heated state and thereafter the drying step is restarted.

主权项

1. A process for producing a water-absorbing resin, comprising a polymerization step of polymerizing an aqueous unsaturated monomer solution and 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, wherein
the drying step is carried out by supplying the particulate water-containing gel-like crosslinked polymer to an air ventilating band type continuous dryer and removing the resulting dried polymer from the dryer, the drying step is interrupted with the dryer kept in a heated state and thereafter the drying step is restarted, and the particulated water-containing gel-like crosslinked polymer is supplied to the dryer after the interruption, the temperature of the dryer during the interruption time of the drying step is 80 to 140° C., and the interruption of the drying step means a state where the particulated water-containing gel-like crosslinked polymer or a dried material thereof is taken out of the dryer in an amount of not less than 95 mass % based on the entire retention capacity of the dryer, or not charged to or not discharged out of the dryer in the continuous drying during the interruption.