Nippon Shokubai Co., Ltd.

Sumito Kumagai

Kunihiko Ishizaki

Kozo Nogi

Shigeru Sakamoto

Satoshi Matsumoto

Yoshifumi Adachi

Ryota Wakabayashi

Yoshihiro Shobo

Mai Sato

Shin-ya Katsube

Tsuyoshi Yorino

Tomoyuki Arake

Sachie Kitabata

Hiroki Hayashi

Naoki Katakura

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

An object of the present invention is to provide a water absorbent resin powder for a heat-generating element composition, which suppresses the generation of the aggregates derived from the water absorbent resin and the adhesion of the water absorbent resin in the production of a heat-generating element composition. A present inventive water absorbent resin powder for a heat-generating element composition includes polyacrylic acid (salt)-based water absorbent resin powder which have a bulk specific gravity (specified by JIS K3362) of 0.630 g/cmor less, fluid retention capacity without load (CRC) for a 0.9% by weight aqueous solution of sodium chloride (specified by ERT441.01-2) of 32.0 g/g or less, a weight-average particle diameter (specified by sieve classification) of 250 μm or more, and an amount of a residual glycidyl-based crosslinking agent of 10 ppm or less.

Water absorbent resin powder for heat-generating element composition, and heat-generating element composition

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Himeji, Japan

Sumito Kumagai