US 12,226,752 B2
Method for regenerating highly water-absorbing polymer, method for producing highly water-absorbing recycled polymer, and use of alkali metal ion source
Ryusei Ito, Sapporo (JP); Haruna Onodera, Sapporo (JP); Naoyuki Funamizu, Sapporo (JP); Takayoshi Konishi, Kanonji (JP); and Kouichi Yamaki, Kanonji (JP)
Assigned to UNICHARM CORPORATION, Ehime (JP)
Appl. No. 16/966,884
Filed by Unicharm Corporation, Ehime (JP)
PCT Filed Feb. 5, 2019, PCT No. PCT/JP2019/004116
§ 371(c)(1), (2) Date Aug. 1, 2020,
PCT Pub. No. WO2019/151538, PCT Pub. Date Aug. 8, 2019.
Claims priority of application No. 2018-018664 (JP), filed on Feb. 5, 2018; and application No. 2018-154170 (JP), filed on Aug. 20, 2018.
Prior Publication US 2021/0039072 A1, Feb. 11, 2021
Int. Cl. B01J 20/26 (2006.01); B01J 20/34 (2006.01)
CPC B01J 20/3475 (2013.01) [B01J 20/261 (2013.01); B01J 20/3425 (2013.01); B01J 20/3483 (2013.01)] 7 Claims
 
1. A method of regenerating superabsorbent polymers which have been inactivated by an acid into superabsorbent recycled polymers which have a predetermined absorption property, the method comprising:
a preparation step of preparing the superabsorbent polymers having an acid group and having been inactivated by the acid,
a superabsorbent recycled polymer formation step of forming wet-state superabsorbent recycled polymers from the superabsorbent polymers which have been inactivated by the acid, by adding an alkali metal ion supply source which is capable of supplying an alkali metal ion to an aqueous solution for regeneration which includes the superabsorbent polymers which have been inactivated by the acid, and
a drying step of forming the superabsorbent recycled polymers which have the predetermined absorption property by drying the wet-state superabsorbent recycled polymers, wherein the predetermined absorption property is adjusted by controlling a pH of the aqueous solution for regeneration, wherein the pH of the aqueous solution for regeneration is adjusted to 5.0 to 9.0 at 25° C., and
the predetermined absorption property is any value of an absorption magnification of 100 to 400 times (g/g) with respect to deionization.