Nippon Shokubai Co., Ltd.

The Procter Gamble Company

Hiroyuki Ikeuchi

Sayaka Machida

Kazushi Torii

Shigeru Sakamoto

Katsuyuki Wada

Taku Iwamura

Makoto Nagasawa

Takahiro Kitano

Taishi Kobayashi

Mariko Tamaki

Manabu Ueda

Yoko Shirai

Kunihiko Ishizaki

Hirotama Fujimaru

Yoshifumi Adachi

Yasuhisa Nakashima

Toshiaki Matsunaga

Taketo Toba

Fumihide Tamura

Kazuo Takei

Koji Tachi

Yoshio Irie

Yusuke Watanabe

Toshimasa Kitayama

Reiko Nakatsuru

Yoshitaka Ikeuchi

Ryoko Tahara

Mattias Schmidt

Kazuhiko Sakamoto

Holger Beruda

Yorimichi Dairoku

Nobuyuki Harada

Makoto Matsumoto

Takumi Hatsuda

Shinichi Fujino

Koji Miyake

Yasuhiro Fujita

Kazuki Kimura

Yoshiro Mitsukami

Masatoshi Nakamura

Juliane Kamphus

Yoshihiko Masuda

Hiroko Ueda

Kazuhisa Hitomi

Yasue Nakagawa

Daisuke Takagi

Taku Fujimoto

Hironori Sato

Hiroko Okochi

Hiroki Kawada

Yasuhisa Nakajima

Eri Nagasawa

Tatsushi Hirauchi

Yuichiro Horimoto

Kunihiki Ishizaki

Hiroyuki Goto

Yuika Noda

Yuka Fujii

Ryuichi Hiraoka

Kazushi Horie

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 present invention provides a contraction agent for a water-absorbing resin that is used as a proppant in stratum hydraulic fracturing, the contraction agent containing: a metal ion-containing substance and a breaking agent for water-absorbing resins used in stratum hydraulic fracturing; and an iron ion-containing substance and/or ascorbic acid, and/or a persulfate. Also provided is a kit for use in stratum hydraulic fracturing, the kit provided with a swelling agent containing a water-absorbing resin, an iron ion-containing substance, and ascorbic acid, the kit being for stratum hydraulic fracturing, wherein the kit consists of A) a proppant containing a water-absorbing resin, and B) a contraction agent for the water-absorbing resin containing a metal ion-containing substance.

Methods of liquefying and shrinking water-absorbable resins in a water-containing state

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 (water absorbing agent) and method for producing it are provided which improve, in a water absorbent article (in particular, a diaper) including a water absorbent resin as a water absorbing agent, the absolute absorption amount (g), liquid absorbing times (in particular, liquid absorbing times at the second instance and later), re-wet (g), and diffusion distance (%) of the water absorbent article. A particulate water absorbing agent of the present invention has a CRC, a proportion of particles with sizes of 600 &#x3bc;m to 150 &#x3bc;m as defined through a standard-sieve classification, an SST, and the value of the difference between an FST and the SST each within a predetermined range.

Particulate water absorbing agent and water absorbent article

An object of the present invention is to provide a method for producing water absorbent resin powder in which permeability potential (SFC) is improved while a water absorbing rate (FSR) is being kept. The method is a method for producing water absorbent polyacrylic acid (salt) resin powder including the steps of: (i) polymerizing an acrylic acid (salt) monomer aqueous solution; (ii) during or after the step of (i), performing gel grinding of a hydrogel crosslinked polymer obtained by the polymerization, wherein the hydrogel crosslinked polymer has resin solid content of 10 wt % to 80 wt %, and the gel grinding is carried out with gel grinding energy (GGE) of 18 [J/g] to 60 [J/g]; (iii) drying a particulate hydrogel crosslinked polymer obtained by the gel grinding, wherein the drying is performed at 150&#xb0; C. to 250&#xb0; C.; and (iv) carrying out a surface treatment to the particulate hydrogel crosslinked polymer thus dried.

Method for producing water absorbent polyacrylic acid (salt) resin powder, and water absorbent polyacrylic acid (salt) resin powder

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

An object of the present invention is to provide (i) a water absorbent agent composition which has an excellent additional function (a deodorizing function in particular), which stably carries out the additional function even after being stored for a long term, and which is less stressful to skin when used as an absorbent article, (ii) a method for producing the water absorbent agent composition, and (iii) an absorbent core and an absorbent article. The water absorbent agent composition contains: a polycarboxylic acid (salt)-based water absorbent resin as a main component; a natural ingredient; and a temporal deterioration preventing agent. Further, a water absorbent agent composition is produced by simultaneously or separately mixing a natural ingredient and a temporal deterioration preventing agent with a water absorbent resin which is a crosslinked polymer of unsaturated monomers having carboxylic acid and/or a salt thereof.

Water absorbent agent composition and method for producing same, as well as storage and stocking method for same

The present invention (a) provides, at low cost, a water absorbing agent (i) that has a suppressed amount of generated dust and a suppressed amount of dust that increases over time and (ii) that also has a high absorption capacity without load, a high absorption capacity under load, a high vertical diffusion absorbency under load, and a high absorbency in a short period of time, and (b) also provides a method for evaluating, in a short period of time, an amount of dust that increases over time. A particulate water absorbing agent of the present invention includes: a surface crosslinked polyacrylic acid (salt)-based water absorbent resin as a main component; a hydrophilic polymer compound; and a stabilizing agent.

Particulate water absorbing agent and process for producing same

Particulate water absorbing agent and method for manufacturing same

[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

The present invention provides a method for producing a water absorbent resin particle, in high productivity, not only in a controlled manner of particle size but also enhancing fundamental property (absorption capacity or absorption capacity against pressure) of a water absorbent resin. A method for producing a water absorbent resin particle having the cross-linking polymerization step for an aqueous solution of an unsaturated monomer; the grain refining step for water-swellable, water-containing gel-like cross-linked polymer (a) obtained in the cross-linking polymerization step; the drying step for grain refined gel; and the crushing step for a dried substance, wherein, in the grain refining step for the water-swellable, water-containing gel-like cross-linked polymer (a), water-swellable, water-containing gel-like cross-linked polymer (b), having solid content or centrifuge retention capacity different from solid content or centrifuge retention capacity of the cross-linked polymer (a) by equal to or larger than 1%, is subjected to coexistence.

Method for producing water absorbent resin particle

The present invention provides a water-absorbing agent that includes water-absorbent resin particles as essential components and is suitable for a sanitary material. A water-absorbing agent of the present invention includes water-absorbent resin particles obtained by polymerizing an unsaturated monomer having an acid group. The water-absorbing agent has centrifuge retention capacity (CRC) of 5 to 20 g/g and includes: a compound with a structure unit derived from polyalkyleneglycol other than the unsaturated monomer; and a multivalent metal salt, and accordingly the water-absorbing agent has high saline flow conductivity (SFC) in a range of the above centrifuge retention capacity (CRC).

Water-absorbing agent and method for producing the same

To provide (i) a water-absorbing agent, having a water-absorbent resin as a main component, whose absorbency is high and liquid permeability is enhanced and (ii) a production method thereof. The water-absorbing agent of the present invention includes a water-absorbent resin obtained by polymerizing an unsaturated monomer having a carboxyl group and included in an aqueous monomer solution in the presence of at least a non high molecular compound having four or more functional groups each capable of forming a covalent bond with a carboxyl group.

Water-absorbing agent having water-absorbent resin as a main component and production method of the water-absorbing agent

An object of the present invention is to provide a particle-shaped water absorbing agent having a remarkably improved surface color and excellent water-absorbing properties (better water absorption capacity, and lower water soluble content and residual monomer content) at the same time. In order to attain the object, a particle-shaped water absorbing agent according to the present invention is a particle-shaped water absorbing agent whose main component is a polyacrylic acid and/or a salt thereof, the particle-shaped water absorbing agent having a surface color of Hunter b value in a range of &#x2212;5 to 10, and having a cross-linking absorption property index (CPI) in a range of 1 to 100, the CPI defined by the following two equations:=(+17)/Ln (water soluble content);&#x2003;&#x2003;Equation 1:=(/residual monomer content)&#xd7;100&#x2003;&#x2003;Equation 3:

Particle-shaped water absorbing agent and method for producing the same

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Himeji, Japan

Hiroyuki Ikeuchi