The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 23, 2015
Filed:
Jan. 23, 2012
Masayoshi Handa, Himeji, JP;
Koji Ueda, Himeji, JP;
Kimihiko Kondo, Himeji, JP;
SUMITOMO SEIKA CHEMICALS CO., LTD., Kako-Gun, JP;
Abstract
A method for producing a water-absorbent resin by a reversed-phase suspension polymerization method, includes step 1 of dispersing a first aqueous solution containing a partially neutralized product (A) of a water-soluble ethylenically unsaturated monomer having acid groups in the molecule in a petroleum-type hydrocarbon dispersion medium in the presence of a dispersing agent, and then polymerizing the resulting dispersion to obtain a slurry containing primary particles of a polymer, and step 2 of adding a second aqueous solution containing a partially neutralized product (B) of a water-soluble ethylenically unsaturated monomer having acid groups in the molecule to the slurry obtained in step 1, and then polymerizing the mixture to obtain a slurry in which the primary particles are agglomerated. In the method, a molar neutralization degree X of the partially neutralized product (A) and a molar neutralization degree Y of the partially neutralized product (B) are defined.