Nippon Shokubai Co., Ltd.

Yoshiki Katada

Kunihiko Ishizaki

Kozo Nogi

Kenji Kadonaga

Motohiro Imura

Shin-Ichi Fujino

Makoto Nagasawa

Ryota Wakabayashi

Koji Honda

Jiro Sano

[Object] To provide a method for stably producing a water-absorbent resin in powder form or particle form, which has excellent physical properties such as water absorption performance and the like, without any production trouble. [Solution] A method for producing a water-absorbent resin includes mixing a monomer composition, which contains at least a monomer and a pyrolytic polymerization initiator, with an organic solvent, a temperature of the organic solvent is not lower than 70&#xb0; C. at time of mixing, and when a mass per unit time of the monomer in the monomer composition to be mixed with the organic solvent is expressed as an amount per unit volume of the organic solvent, a lower limit is 0.01 g/ml/min, and an upper limit is 0.2 g/ml/min.

Method for producing water-absorbent resin

The purpose of the present invention is to provide a process for stably and continuously producing a water-absorbing resin, specifically, a process for stably and continuously producing a water-absorbing resin, the process including a gas absorbing step in which a gas discharged from a step of producing a water-absorbing resin is efficiently and persistently absorbed. A main point of this process for producing a water-absorbing polyacrylic acid (salt) resin further including a step of absorbing a gas discharged from a production step of the water-absorbing polyacrylic acid (salt) resin in water having a pH of 7 to 11 and a polyvalent metal ion content of 100 ppm or less or a step of absorbing the gas in water having a pH of 7 to 11, the pH of the water having been adjusted by mixing a water having an electric conductivity of 500 (&#x3bc;S/cm) or less at 25&#xb0; C. with an alkali compound.

Process for producing water-absorbing polyacrylic acid (salt) resin

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Himeji, Japan

Yoshiki Katada