US 12,187,860 B2
Water-absorbent resin powder and production method thereof
Tsuyoshi Yorino, Himeji (JP); Naoki Katakura, Suita (JP); Hiroki Hayashi, Himeji (JP); Sumito Kumagai, Himeji (JP); Masahumi Inoue, Himeji (JP); Tomoyuki Arake, Himeji (JP); Mai Sato, Himeji (JP); Ryota Wakabayashi, Himeji (JP); Yoshihiro Shobo, Suita (JP); Shin-ya Katsube, Himeji (JP); Yoshifumi Adachi, Himeji (JP); and Satoshi Matsumoto, Himeji (JP)
Assigned to NIPPON SHOKUBAI CO., LTD., Osaka (JP)
Appl. No. 17/055,153
Filed by NIPPON SHOKUBAI CO., LTD., Osaka (JP)
PCT Filed May 16, 2019, PCT No. PCT/JP2019/019518
§ 371(c)(1), (2) Date Nov. 13, 2020,
PCT Pub. No. WO2019/221236, PCT Pub. Date Nov. 21, 2019.
Claims priority of application No. 2018-094788 (JP), filed on May 16, 2018; and application No. 2018-210731 (JP), filed on Nov. 8, 2018.
Prior Publication US 2021/0115198 A1, Apr. 22, 2021
Int. Cl. C08J 3/12 (2006.01); C08F 20/06 (2006.01); C08J 3/075 (2006.01); C08J 3/20 (2006.01); C08J 3/24 (2006.01)
CPC C08J 3/12 (2013.01) [C08F 20/06 (2013.01); C08J 3/075 (2013.01); C08J 3/20 (2013.01); C08J 3/203 (2013.01); C08J 3/245 (2013.01); C08J 2300/14 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A method of producing a water-absorbent resin powder, the method comprising:
a drying step of drying a particulate hydrogel crosslinked polymer which is obtained using an acid group-containing unsaturated monomer as a main component to obtain a dried polymer, and
a fine powder granulation step of adding a binder and an adhesion controlling agent to fine powder formed of a water-absorbent resin to obtain a fine powder granulated product,
wherein the fine powder granulated product is recovered after the gel crushing step and before the drying step, or during the drying step;
wherein the adhesion controlling agent is added in a form of aqueous solution; and
an added amount of the adhesion controlling agent is from 0.02 mass % to 1.0 mass % relative to the solid content of the fine powder formed of the water-absorbent resin;
wherein a stirring dryer having one or more of heating means selected from a group of a ventilation heating type, an outer wall heating type and a tubular heating type in the drying step;
wherein a temperature of the fine powder granulated product and the particulate hydrogel cross-linked polymer is in a range of 50° C. or more to 100° C. or less; and
a temperature difference between the fine powder granulated product and the particulate hydrogel cross-linked polymer is within 30° C.