Nippon Shokubai Co., Ltd.

Tsuyoshi Yorino

Yoshifumi Adachi

Ryota Wakabayashi

Yoshihiro Shobo

Shigeru Sakamoto

Daisuke Takagi

Yoshitaka Ikeuchi

Mai Sato

Shin-ya Katsube

Daisuke Takeda

Tomoyuki Arake

Sachie Kitabata

Hiroki Hayashi

Naoki Katakura

Kunihiko Ishizaki

Satoshi Matsumoto

Motohiro Imura

Shin-Ichi Fujino

Koji Honda

Tokio Shuto

Masafumi Inoue

Hiroyasu Watabe

Sumito Kumagai

Masahumi Inoue

The present invention addresses the problem of providing; a water absorbent resin powder having a reduced amount of fine powder generated and a reduced amount of fine powder recovered; and a production method for the water absorbent resin. The production method of the present invention includes a drying step and a fine powder granulation step. The drying step is for obtaining a dried polymer by drying a particulate water-containing gel crosslinked polymer which is obtained using an acid group-containing unsaturated monomer as a main component. The fine powder granulation step is for obtaining a fine powder granulated product by adding a binder and an adhesion control agent to a fine powder made of a water absorbent resin. In this production method, the obtained fine powder granulated product is recovered in the drying step or in any step before the drying step.

Water-absorbent resin powder and production method thereof

To provide a disposable diaper enabling reduction in re-wet amount and having an excellent speed of incorporating liquid regardless of concentration and configuration of a water-absorbing agent in an absorbent material. A water-absorbing agent having excellent Gel Capillary Absorption (GCA) and Free Gel Bed Permeability (FGBP) is obtained by crushing a crosslinked hydrogel polymer obtained in a polymerization step to have a specific weight average particle diameter while fluid retention capacity and a surface tension of a water-absorbing agent are adjusted in a specific range, drying the crushed crosslinked hydrogel polymer, and then adding a liquid permeability enhancer thereto during surface crosslinking or after surface crosslinking.

Poly (meth) acrylic acid (salt)-based particulate water-absorbing agent and production method therefor

The production method includes: a gel-crushing step of grinding a crosslinked hydrogel polymer to obtain a particulate crosslinked hydrogel polymer; a heating drying step of obtaining dried particles from the particulate crosslinked hydrogel polymer by using a continuous stirring drying machine; a post-crosslinking step of post-crosslinking the particulate crosslinked hydrogel polymer or the dried particles; and a sizing step of adjusting a particle size of the dried particles or the post-crosslinked dried particles to obtain water-absorbent resin powder. The particulate crosslinked hydrogel polymer contains a gel fluidizer. A gel temperature of the particulate crosslinked hydrogel polymer containing the gel fluidizer, the gel temperature being measured by a contact thermometer, is not lower than 50&#xb0; C. In the production method, the dried particles or the post-crosslinked dried particles is forcedly cooled before the sizing step.

Method for producing water-absorbent resin powder and production apparatus therefor

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Himeji, Japan

Tsuyoshi Yorino