Nippon Shokubai Co., Ltd.

The Procter Gamble Company

Taku Fujimoto

Kazushi Torii

Kenji Kadonaga

Sayaka Machida

Kazuki Kimura

Taku Iwamura

Yoshiro Mitsukami

Yusuke Watanabe

Hiroki Kawada

Erina Minami

Kazuyuki Oshima

Yasuhisa Nakajima

Hiroyuki Ikeuchi

Peter Dziezok

Takahiro Kitano

Taishi Kobayashi

Marion Lutsche

Daisuke Takagi

Hidenori Wada

Mariko Tamaki

Gabriela Schaefer

Hiroyuki Goto

Yuichiro Horimoto

To provide a water-absorbing resin composition having both a high centrifuge retention capacity (CRC) and a sufficient urine resistance and a method for producing such a water-absorbing resin composition, an aspect of the present invention is a water-absorbing resin composition having the following properties: (1) A centrifuge retention capacity (CRC) being not less than 35 g/g; (2) A post-degradation-test one-hour eluted soluble component being not more than 19% by mass; (3) An absorbency against pressure 0.7 psi (AAP0.7) being not less than 10 g/g; and (4) A content of a water-absorbing resin in dust being not more than 300 ppm with respect to a total mass of the water-absorbing resin composition.

Water-absorbing resin composition

A water-absorbing resin having a high swollen gel elastic modulus, a high swelling capacity and a method for producing the same are provided where the water-absorbing resin includes a water soluble unsaturated monomer having a dissociable group, an internal crosslinked structure index expressed by the following numerical formula of 14 or more, a weight average molecular weight (Mw) after a hydrolysis treatment of 220,000 or less, and a molecular weight distribution (Mw/Mn) after a hydrolysis treatment of 3.40 or less: Crosslinked structure index=(Equilibrium swelling capacity with respect to 0.9 wt % physiological saline solution/(Weight average molecular weight (Mw) after hydrolysis treatment)&#xd7;1000000; where the hydrolysis treatment leaves 50 mg of the water-absorbing resin as a solids content to stand still in 10 g of a 0.1 mol/l aqueous sodium hydroxide solution for 3 weeks at 80&#xb0; C., and the weight average molecular weight (Mw) is measured after the treatment.

Absorbent resin and method for producing the same

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

Absorbing articles comprises water absorbing resin including a water-soluble unsaturated monomer, having a dissociable group, as a main component in a repeating unit of a main chain and an internal cross-linked structure, in which a cross-linked structure index represented by the formula [Cross-linked structure index=(Equilibrium swelling capacity with respect to 0.9% by weight of brine)/(Weight average molecular weight after hydrolysis treatment)&#xd7;1,000,000] is 14 or more, a weight average molecular weight after hydrolysis treatment is 220,000 or less, and a molecular weight distribution after hydrolysis treatment is 3.40 or less, and a method for producing the same.

Absorbing articles comprising water absorbing resin and method for producing the same

The present invention relates to an absorbent suitable for use in a thin sanitary material/absorbent article having a high absorbent content and not prone to gel blocking, the absorbent having excellent liquid diffusibility (e.g. SFC) and minimal decrease in absorption ratio under pressure (e.g., AAP or PUP) even when a liquid permeation enhancer is added, and to a method for manufacturing the high-performance absorbent stably during actual production. The method is a method for manufacturing a polyacrylic acid (salt)-based absorbent, having a surface-crosslinking agent addition step for adding a solution of a surface-crosslinking agent, and a liquid permeation enhancer addition step for adding a liquid permeation enhancer, the liquid permeation enhancer addition step being performed after and/or at the same time as the surface-crosslinking agent addition step, the method characterized in that a surface crosslinking step for performing heat treatment in an atmosphere having a dew point of 45&#xb0; C. to 100&#xb0; C. is performed after or at the same time as the surface-crosslinking agent addition step.

Method for producing polyacrylic acid (salt)-based water absorbing agent, and water absorbing agent

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Himeji, Japan

Taku Fujimoto