METHOD FOR PRODUCING WATER-ABSORBING RESIN

Title:

METHOD FOR PRODUCING WATER-ABSORBING RESIN

Document Type and Number:

WIPO Patent Application WO/2012/081355

Kind Code:

A1

Abstract:

The main purpose of the present invention is to provide a method for producing a water-absorbing resin, said water-absorbing resin being slightly colored by a high-temperature treatment, having a small fine powder content and a small coarse powder content, and showing a narrow particle size distribution. The method for producing a water-absorbing resin comprises: (1) step (1) for conducting reversed phase suspension polymerization of a water-soluble ethylenically unsaturated monomer in a petroleum hydrocarbon dispersion medium containing a surfactant dissolved therein to give a slurry in which primary particles are dispersed; and (2) step (2) for cooling the slurry obtained in step (1) to precipitate a portion of the surfactant, and then polymerizing a water-soluble ethylenically unsaturated monomer in said slurry to aggregate the primary particles, thereby giving a water-absorbing resin, wherein said surfactant is a sucrose fatty acid ester comprising 25 mass% or less of a monoester, 10 mass% or more of a tetraester and 30 mass% or less of tetra- and higher esters.

Inventors:

TAKATORI JUNICHI (JP)
ISOKAWA SHO (JP)
ONODA YUICHI (JP)
UEDA KOJI (JP)

Application Number:

PCT/JP2011/076555

Publication Date:

June 21, 2012

Filing Date:

November 17, 2011

Export Citation:

Click for automatic bibliography generation Help

Assignee:

SUMITOMO SEIKA CHEMICALS (JP)
TAKATORI JUNICHI (JP)
ISOKAWA SHO (JP)
ONODA YUICHI (JP)
UEDA KOJI (JP)

International Classes:

C08F2/32; C08F2/18; C08F20/06

Domestic Patent References:

WO2007126003A1	2007-11-08
WO2007123188A1	2007-11-01

Foreign References:

JPS6187702A	1986-05-06
JPH0770245A	1995-03-14
JP2006001976A	2006-01-05
JPH03227301A	1991-10-08

Other References: