Method for producing water-absorbent resin powder and production apparatus therefor
US11465126B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 16, 2017 |
| Grant date | Oct 11, 2022 |
| Priority date | — |
| Expiry date | May 8, 2039 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F2810/20
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
The production method includes: a gel-crushing step of grinding a crosslinked hydrogel polymer to obtain a particulate crosslinked hydrogel polymer; a heating drying step of obtaining dried particles from the particulate crosslinked hydrogel polymer by using a continuous stirring drying machine; a post-crosslinking step of post-crosslinking the particulate crosslinked hydrogel polymer or the dried particles; and a sizing step of adjusting a particle size of the dried particles or the post-crosslinked dried particles to obtain water-absorbent resin powder. The particulate crosslinked hydrogel polymer contains a gel fluidizer. A gel temperature of the particulate crosslinked hydrogel polymer containing the gel fluidizer, the gel temperature being measured by a contact thermometer, is not lower than 50° C. In the production method, the dried particles or the post-crosslinked dried particles is forcedly cooled before the sizing step.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.