Method for producing water-absorbing agent
US11806692B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 20, 2017 |
| Grant date | Nov 7, 2023 |
| Priority date | — |
| Expiry date | Jul 17, 2038 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08K5/19
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
[Object] To provide a method for efficiently producing a water-absorbing agent having excellent physical properties.[Solution] The method for producing a water-absorbing agent includes a drying step of drying a particulate crosslinked hydrogel polymer containing a drying aid. The drying aid is (a) a compound having a betaine structure and having a long-chain alkyl group having 8 or more carbon atoms, one quaternary nitrogen, and one acid group within a molecule thereof and/or (b) a compound having a long-chain alkyl group having 8 or more carbon atoms, one tertiary nitrogen, and one or more acid groups within a molecule thereof. An addition amount of the drying aid with respect to a gel solid content of the particulate crosslinked hydrogel polymer is 0.001% by mass to 0.5% by mass. In this production method, surface-crosslinking is performed on water-absorbent resin powder obtained through the drying step.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.