Nippon Shokubai Co., Ltd.

The Procter Gamble Company

Nippon Shokubai Kagaku Kogyo Co., Ltd.

Taku Iwamura

Kazushi Torii

Yoshiro Mitsukami

Sayaka Machida

Hiroyuki Ikeuchi

Kozo Nogi

Makoto Matsumoto

Koji Miyake

Motohiro Imura

Katsuyuki Wada

Shigeru Sakamoto

Masatoshi Nakamura

Hirofumi Shibata

Taishi Kobayashi

Hiroki Kawada

Yoshio Irie

Yorimichi Dairoku

Kenji Kadonaga

Yusuke Watanabe

Hiroko Ueda

Takahiro Kitano

Koji Honda

Taku Fujimoto

Masato Abe

Yasuhisa Nakajima

Mattias Schmidt

Holger Beruda

Shinichi Fujino

Yoshifumi Adachi

Kazuki Kimura

Hiroki Inoue

Toshimasa Kitayama

Yasuhisa Nakashima

Yoshihiro Shobo

Yasue Nakagawa

Daisuke Takagi

Hidenori Wada

Hiroko Okochi

Koji Tachi

Yukihiro Kasano

Mariko Tamaki

Hiroyasu Watabe

Makiko Masuda

Hiroyuki Goto

Shin-ichi Fujino

Yuichiro Horimoto

Yoshiro c/o Nippon Shokubai Coltd Mitsukami

Provided is a water-absorbing agent that causes no or little fluctuation of feed rate when fed with use of a feeder. A water-absorbing agent containing a water-absorbing resin as a main component, the water-absorbing agent satisfying the following (a) and (b): (a) K-index is 70 or more; and (b) Moisture absorption blocking ratio, after 30 minutes of standing at a temperature of 25&#xb0; C. and a relative humidity of 80% RH, is 70 weight % or less, the K-index being defined by the following equation: K-index=100&#x2212;(&#x2212;438+3.6&#xd7;angle of repose+3.5&#xd7;angle of difference+7.9&#xd7;compressibility rate+290&#xd7;bulk density (EDANA method)).

Absorption agent and absorbent article

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

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

A water-absorbent resin composition is provided which shows only small reduction in liquid permeability and limited coloring over time or in relation to another factor. The water-absorbent resin composition (particulate absorbent agent) of the present invention contains: a polycarboxylate-based water-absorbent resin as a primary component, the resin having a crosslinked structure formed by polymerization of an acid group-containing unsaturated monomer; and multivalent metal cations (preferably, on surfaces of particles (i.e., the water-absorbent resin composition)) wherein: the multivalent metal cations other than Fe cations account for 0.001 to 1 mass % of the water-absorbent resin; and the ratio of the Fe cations to the multivalent metal cations other than the Fe cations is less than or equal to 5.00 mass %.

Water-absorbent resin composition, method of manufacturing the same, and absorbent article

A water-absorbent resin composition is provided which shows only small reduction in liquid permeability and limited coloring over time or in relation to another factor. The water-absorbent resin composition (particulate absorbent agent) of the present invention contains: a polycarboxylate-based water-absorbent resin as a primary component, the resin having a crosslinked structure formed by polymerization of an acid group-containing unsaturated monomer; and multivalent metal cations (preferably, on surfaces of particles (i.e., the water-absorbent resin composition)) wherein: the multivalent metal cations other than Fe cations account for 0.001 to 1 mass % of the water-absorbent resin; and the ratio (in terms of percentage) of the Fe cations to the multivalent metal cations other than the Fe cations is less than or equal to 5.00 mass %.

A particulate water absorbing agent of the present invention is a water absorbing agent containing a water absorbing resin as a main component, the particulate water absorbing agent containing a polyvalent metal cation and satisfying: (1) the polyvalent metal cation is contained in an amount between 0.001 wt % and 5 wt % relative to the amount of the water absorbing agent; (2) an absorbency without pressure (CRC) is not less than 28 (g/g) and an absorbency against pressure (AAP 4.83 kPa) is not less than 10 (g/g); (3) the absorbency against pressure and the absorbency without pressure satisfy 77 &#x2266;AAP (4.83 kPa)+1.8&#xd7;CRC&#x2266;100; and (4) a moisture content of the water absorbing agent is between 5 wt % and 20 wt %. This provides a water absorbing agent which has blocking resistance after moisture absorption, is excellent in stability to shock and suppresses Re-Wet when used in a diaper.

Particulate water absorbent and process for production thereof

Provided is a surface treatment method for a water-absorbent resin having excellent production efficiency, absorption capacity against pressure, fluid permeability or the like. Provided is a method for the surface treatment of a water-absorbent resin which comprises a) a step for mixing 0.1 to 20 parts by weight of an acid group-containing radically polymerizable compound and 5 to 20 parts by weight of water, relative to 100 parts by weight of a water-absorbent resin; and b) a step for polymerizing the acid group-containing radically polymerizable compound, wherein neutralization ratio of the acid group-containing radically polymerizable compound is 0 to 60% by mol, and is lower than neutralization ratio of the water-absorbent resin.

Surface treatment method for water-absorbent resin

A particulate water absorbing agent of the present invention is a water absorbing agent containing a water absorbing resin as a main component, the particulate water absorbing agent containing a polyvalent metal cation and satisfying: (1) the polyvalent metal cation is contained in an amount between 0.001 wt % and 5 wt % relative to the amount of the water absorbing agent; (2) an absorbency without pressure (CRC) is not less than 28 (g/g) and an absorbency against pressure (AAP 4.83 kPa) is not less than 10 (g/g); (3) the absorbency against pressure and the absorbency without pressure satisfy 77&#x2266;AAP (4.83 kPa)+1.8&#xd7;CRC&#x2266;100; and (4) a moisture content of the water absorbing agent is between 5 wt % and 20 wt %. This provides a water absorbing agent which has blocking resistance after moisture absorption, is excellent in stability to shock and suppresses Re-Wet when used in a diaper.

An absorbent article that has a thin, conformable absorbent core where the core has at least two layers, both of which are substantially free of cellulosic fibers is described. The first layer is intended to provide storage for the majority of acquired fluids and has an AAP of at least about 20 g/g and the second layer, which provides temporary capacity for the bulk of the acquired fluid and permanent storage for at least a portion thereof, comprises a second absorbent polymer material which has a Wet Permeability of at least about 400&#xd7;10(cmseconds)/g a ratio of Wet Permeability to SFC of at least about 1.5:1 with respect to the first absorbent polymer material.

Diaper with improved body fit

An object of the present invention is to provide a water absorbent having excellent gel properties and showing excellent properties when used in a water-absorbing material of a sanitary/hygienic material such as paper diaper. Moreover, another object of the present invention is to provide a water absorbent which is safe and excellent in liquid permeability, and in which an amount of liquid permeability improver for improving the liquid permeability is reduced. The water absorbent is made from a water-absorbing resin prepared by a specific polymerization method and having a high degree of cross-linking, a high liquid holding property and a high gel strength (its swelling pressure of gel layer of is 35 kdyne/cm2 or more). This water absorbent is further processed to have a particular particle size distribution (95 wt % or more of its particles are less than 850&fnof;&#xca;m but not less than 106&fnof;&#xca;m, and logarithmic standard deviation (&fnof;&Dstrok;&fnof;&#xc4;) is in a range of 0.25 to 0.45) and then surface cross-linked. After that, a liquid permeability improver is added therein.

Water absorbent and producing method of same

There are disclosed a water-absorbent resin composition and its production process, wherein the water-absorbent resin composition causes little gel-blocking and is excellent in the liquid permeability and liquid diffusibility and is high also in the absorption performances and further is strong also against the physical damage; and there are further disclosed a water-absorbent resin composition and its production process, wherein the water-absorbent resin composition has the following further advantages, in addition to the above, of involving little segregation of the metal compound and further having a dust prevention effect. One of water-absorbent resin compositions according to the present invention is a water-absorbent resin composition comprising water-absorbent resin particles obtained by polymerizing a monomer including acrylic acid and/or its salt, with the composition having a mass-average particle diameter of 100 to 600 &#x3bc;m and comprising water-soluble polyvalent metal salt particles and the water-absorbent resin particles that have been surface-crosslinked.

Water-absorbent resin composition and its production process

An object of the present invention is to provide an aqueous-liquid-absorbing agent which comprises water-absorbent resin particles as essential components and is suitable for uses in sanitary materials. As a means of achieving this object, an aqueous-liquid-absorbing agent according to the present invention is an aqueous-liquid-absorbing agent comprising water-absorbent resin particles as essential components, wherein the water-absorbent resin particles are obtained by a process including the step of polymerizing a water-soluble ethylenically unsaturated monomer and have a crosslinked structure in their inside; with the aqueous-liquid-absorbing agent exhibiting an absorption rate (FSR) of not less than 0.2 g/g/s, a water absorption capacity (CRC) of 5 to 25 g/g, a saline flow conductivity (SFC) of not less than 400&#xd7;10cm&#xb7;s/g, and a wet porosity of not less than 20%.

Aqueous-liquid-absorbing agent and its production process

The production method of a water absorbent resin composition including a particulate water absorbent resin, wherein: 95 wt % or more of particles whose particle diameter is less than 850 &#x3bc;m and not less, than 106 &#x3bc;m are contained, and a weight average particle diameter of the particles is less than 500 &#x3bc;m and not less than 300 &#x3bc;m and a logarithmic standard deviation (&#x3c3;&#x3be;) of a particle size distribution is 0.45 or less, and a water-soluble component of the water absorbent composition is 35 wt % or less, and a multivalent metal component is contained, and an extraction rate of the multivalent metal component is 5.0 wt % or more and less than 100 wt %, thereby providing the water absorbent resin composition, free from any coagulation of particles in high humidity, which has superior absorbent property in terms of an absorbency and a diffusing absorbency under pressure.

Water absorbent resin composition and production method thereof

This invention is to provide a method for surface-treatment of a water absorbent resin excelling in water absorption properties. This invention relates to a method for the surface-treatment of a water absorbent resin, which comprises: a) mixing 100 parts by weight of a water absorbent resin, 0.01-20 parts by weight of at least one radical polymerization initiator selected from the group consisting of persulfates, hydrogen peroxide, and azo compounds, and a radically polymerizing compound and b) irradiating the resultant mixture with active energy rays. The treatment particularly exalts the absorption ratio against pressure and the saline flow conductivity.

Method for surface-treatment of water absorbent resin

An absorbent member and a method for making such an absorbent member. The absorbent member includes a modified water absorbent resin having good production efficiency, absorbency against pressure, absorption speed, gel strength, and liquid permeability. The modified water absorbent resin may be made by mixing a water absorbent resin, water, and a water-soluble radical polymerization initiator without addition of an ethylenically unsaturated monomer to obtain a water absorbent resin composition, and irradiating the water absorbent resin composition with active energy rays. During irradiation, the surface water content of the water absorbent resin is at least 3.0 wt %.

Absorbent article comprising a modified water absorbent resin

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Himeji, Japan

Taku Iwamura