Method for producing a water-absorbent resin
US8883944B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 20, 2011 |
| Grant date | Nov 11, 2014 |
| Priority date | — |
| Expiry date | Jul 20, 2031 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F220/56
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A method for producing a water-absorbent resin by performing a reversed-phase suspension polymerization of a water-soluble ethylenically unsaturated monomer in a petroleum hydrocarbon dispersion medium, comprising the following steps of: (A) performing a primary dispersion in the absence of surfactants by adding an aqueous solution of a water-soluble ethylenically unsaturated monomer containing a hydrophilic polymeric dispersion agent to a petroleum hydrocarbon dispersion medium in which a hydrophobic polymeric dispersion agent was heat-dispersed or heat-dissolved, under stirring; (B) further performing a secondary dispersion by adding a surfactant to a dispersion liquid obtained after the primary dispersion; and (C) performing the reversed-phase suspension polymerization by using a radical polymerization initiator; and the water-absorbent resin obtained by the method.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.