Method for manufacturing water absorbing agent
US11224857B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 28, 2017 |
| Grant date | Jan 18, 2022 |
| Priority date | — |
| Expiry date | Apr 6, 2038 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08L33/02
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A water absorbent agent having a high water absorption multiplying factor where stickiness after absorbing liquid can be reduced when used as a hygienic material is produce by a method for manufacturing the water absorbing agent. The method for manufacturing a water absorbent agent having a centrifuge retention capacity (CRC) of 30 g/g or greater, includes subjecting an aqueous solution of a monomer that includes an acrylic acid (salt) to a polymerization step, a drying step, and a surface cross-linking step, and a step for adding α-hydroxycarboxylic acid (salt) before the drying step. The atomic weight of the soluble portion eluted when the water absorbent agent absorbs liquid and swells can be reduced by the α-hydroxycarboxylic acid (salt) before the drying step to reduce the stickiness of the water absorbent agent after absorption of liquid, which leads to discomfort during use of disposable diapers and the like.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.