Water absorbent material, method for production of surface cross-linked water absorbent resin, and method for evaluation of water absorbent material
US8501873B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 31, 2005 |
| Grant date | Aug 6, 2013 |
| Priority date | — |
| Expiry date | Apr 25, 2027 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2982
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A homogeneously surface cross-linked water absorbent resin and a method for the production thereof are provided.The water absorbent material is formed of a surface cross-linked water absorbent resin resulting from granular irregularly pulverized shaped surface cross-linking the product of partial neutralization or whole neutralization of a water absorbent resin having acrylic acid or a metal salt thereof as a main component, which water absorbent material shows a metal atom concentration on the surface of the water absorbent material in the range of 0-10% within 0 second of polishing and 2-35% at 10 seconds value of polishing as determined by subjecting the water absorbent material to Ar ion discharge polishing under a voltage of 500 Å. The surface cross-linked water absorbent resin to be used herein can be produced by surface cross-linking a water absorbent resin having a specific particle diameter with a surface cross-linking agent having a water concentration in a specific range.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.