Method for producing polyacrylic acid (salt)-based water absorbent resin
US11459431B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 17, 2020 |
| Grant date | Oct 4, 2022 |
| Priority date | — |
| Expiry date | Jul 18, 2040 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08J2333/02
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
As a method for producing a polyacrylic acid (salt)-based water absorbent resin particle which less generates fine powder and has an excellent impact resistance and a high moisture content even in a case where the polyacrylic acid (salt)-based water absorbent resin particle is produced on a large scale, employed is a production method including the steps of: (a) adding a surface crosslinking agent solution to water absorbent resin powder to obtain a mixture; (b) reacting the mixture; and, thereafter (c) adding an aqueous liquid to at least one selected from the group consisting of (i) the water absorbent resin powder during the step (b) and (ii) the water absorbent resin powder after the step (b), an atmospheric dew point being not lower than 20° C. in the step (c), and a temperature of the water absorbent resin powder being higher than the atmospheric dew point in the step (c).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.