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:
May. 21, 2019
Filed:
Sep. 30, 2010
Satoshi Matsumoto, Hyogo, JP;
Kunihiko Ishizaki, Hyogo, JP;
Kazushi Torii, Hyogo, JP;
Shin-ichi Fujino, Hyogo, JP;
Kazuhiko Sakamoto, Hyogo, JP;
Satoshi Matsumoto, Hyogo, JP;
Kunihiko Ishizaki, Hyogo, JP;
Kazushi Torii, Hyogo, JP;
Shin-ichi Fujino, Hyogo, JP;
Kazuhiko Sakamoto, Hyogo, JP;
NIPPON SHOKUBAI CO., LTD., Osaka, JP;
Abstract
A method for producing a polyacrylic acid (salt)-based water absorbent resin, sequentially including the steps of: storing or producing acrylic acid; mixing acrylic acid containing a polymerization inhibitor with water, a crosslinking agent, and optionally, a basic composition, and/or neutralizing them, to prepare an aqueous monomer solution; polymerizing the aqueous monomer solution; drying an obtained water-containing gel-like crosslinked polymer; and optionally carrying out surface crosslinking, wherein the acrylic acid containing the polymerization inhibitor has a water content of not higher than 1,000 ppm (by mass; the same applies hereinafter), and/or the aqueous monomer solution has a formic acid content of 1 to 700 ppm, relative to the monomer.