Process for producing water-absorbing resin powder
US9976001B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 10, 2011 |
| Grant date | May 22, 2018 |
| Priority date | — |
| Expiry date | Feb 10, 2031 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08J2300/14
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Provided is a process for producing a water-absorbing resin powder which contains a given amount of water added thereto, has a low dust content, and has high material properties. When a water-absorbing resin powder which has undergone surface crosslinking is produced on an industrial scale, various problems concerning production are eliminated and a long-term stable operation is possible without causing a deterioration in the material properties of the resin. Even when the process is continued over a long period, the material properties are stabilized (decrease in standard deviation) or improved (improvement in AAP). The process for producing a water-absorbing resin comprises, in the following order, a first classification step for classifying a water-absorbing resin, a surface crosslinking step after the classification, a water addition step for adding water to the water-absorbing resin powder after or during the surface crosslinking, a second classification step, and a conveying step.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.