Nippon Shokubai Co., Ltd.

Mariko Tamaki

Hiroyuki Ikeuchi

Taishi Kobayashi

Kazushi Torii

Sayaka Machida

Taku Iwamura

Takahiro Kitano

Daisuke Takagi

Taku Fujimoto

Hiroki Kawada

Yasuhisa Nakajima

Hiroyuki Goto

Yuichiro Horimoto

A water absorbent agent having a high water absorption multiplying factor where stickiness after absorbing liquid can be reduced when used as a hygienic material is produce by a method for manufacturing the water absorbing agent. The method for manufacturing a water absorbent agent having a centrifuge retention capacity (CRC) of 30 g/g or greater, includes subjecting an aqueous solution of a monomer that includes an acrylic acid (salt) to a polymerization step, a drying step, and a surface cross-linking step, and a step for adding &#x3b1;-hydroxycarboxylic acid (salt) before the drying step. The atomic weight of the soluble portion eluted when the water absorbent agent absorbs liquid and swells can be reduced by the &#x3b1;-hydroxycarboxylic acid (salt) before the drying step to reduce the stickiness of the water absorbent agent after absorption of liquid, which leads to discomfort during use of disposable diapers and the like.

Method for manufacturing water absorbing agent

The purpose of the present invention is to provide a particulate water absorbing agent having both a high water absorption multiplying factor and a high water absorption rate and a method for manufacturing the same. The present invention is a particulate water absorbing agent for which CRC is 30 to 50 g/g, wherein the weight average particulate diameter (D50) is 200-600 &#x3bc;m, and the DRC index given by the following formula is a specific value (for example, 43, 30, or 20) or less: DRC index=(49&#x2212;DRC5min [g/g])/(D50 [&#x3bc;m]/1000).

Particulate water absorbing agent

It is an object to provide a particulate water-absorbing agent having a high fluid retention capacity under pressure and reduced moisture absorption blocking properties, and a method for producing the same. A particulate water-absorbing agent including a water-insoluble metal phosphate including an anion of a phosphoric acid compound and a divalent or trivalent metal cation, the water-insoluble metal phosphate having a crystallite size of less than 0.15 &#x3bc;m, wherein the particulate water-absorbing agent has a fluid retention capacity under pressure of 2.06 kpa of 20 g/g or more.

Particulate water-absorbing agent

[Problem] To provide a dust reducer which suppresses blocking against moisture absorption and has a reduced amount of dust generation, without impairing the water absorption physical properties that are required from a water absorbing agent, such as water absorption capacity under load; a method for producing a water absorbing agent using the dust reducer; and a water absorbing agent in which blocking against moisture absorption is suppressed and which has a reduced amount of dust generation. [Solution] A dust reducer for a water absorbing agent containing a surface crosslinked polyacrylic acid (salt)-based water absorbent resin as a main component, wherein the dust reducer is a multi-component metal compound which has a hydrotalcite structure and contains a hydroxyl group and two kinds of metal cations that are divalent and trivalent.

Dust reducer consisting of multi-component metal compound, water absorbing agent containing multi-component metal compound, and method for producing the same

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Himeji, Japan

Mariko Tamaki