Particulate water absorbent agent and production method thereof, and water absorbent article
US7473739B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 4, 2005 |
| Grant date | Jan 6, 2009 |
| Priority date | — |
| Expiry date | Nov 3, 2025 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08J2300/102
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A particulate water absorbing agent of the present invention includes a water absorbent resin, having a cross-linking structure, whose surface has been cross-linked by adding a surface treatment agent, wherein: (i) a mass average particle diameter (D50) ranges from 200 to 600 μm and 95 to 100 wt % of a particulate water absorbing agent whose particle diameter ranges from less than 850 μm to not less than 150 μm is contained with respect to 100 wt % of whole the particulate water absorbing agent, and (ii) a logarithmic standard deviation (σζ) of particle size distribution ranges from 0.25 to 0.45, and (iii) a compressibility rate defined by a following equation ranges from 0 to 18%, and (iv) a surface tension of a supernatant liquid obtained in 4 minutes after dispersing 0.5 g of the particulate water absorbing agent in 50 ml of physiological saline whose temperature is 20° C. is 55 mN/m or more,the compressibility rate (%)=(P−A)/P×100where P represents a tapped bulk density of the particulate water absorbing agent and A represents a loose bulk density of the particulate water absorbing agent.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.