Sumitomo Seika Chemicals Co., Ltd.

Yuichi Onoda

Kenji Tanimura

Mikito Chiba

Masayoshi Handa

Atsushi Heguri

Hiroki Yabuguchi

Seiji Bando

Koji Ueda

Hisaaki Kanda

Masayoshi Miyada

A water-absorbing resin that exhibits excellent absorption performance and a high permeation rate with respect to liquids to be absorbed, and that effectively reduces liquid leakages, even in an absorbent body using a large amount of the water-absorbing resin. The water-absorbing resin is formed from a polymer of a water-soluble ethylenically unsaturated monomer, and when a cross-sectional image of the water-absorbing resin obtained by X-ray computer tomography is observed, the percent area of cavity portions in the cross-sectional image is 2-10%. The liquid flow rate index when a physiological saline liquid column flow rate test is performed on the water-absorbent resin having a particle diameter of 250 to 500 &#x3bc;m at 37&#xb0; C. is 5-20.

Water-absorbing resin

Provided is a water-absorbent resin that quickly absorbs water, even in sandbag in which a large amount of the water-absorbent resin has been used, that does not easily form unswollen lump, and that has a high gel swelling volume when water is used to swell the water-absorbent resin. This water-absorbent resin is configured from a polymer of water-soluble ethylenic unsaturated monomers. The physiological-saline absorption capacity of the water-absorbent resin is 40-60 g/g. When a cross-sectional image of the water-absorbent resin is observed by x-ray computed tomography, the fraction of the area of the cross-sectional image that is hollow portions (the hollow area ratio of the cross-sectional image), as calculated on the basis of formula (I), is no more than 10%. (I) Hollow area ratio [%]={total cross-sectional area (B) of hollow portions of the water-absorbent resin/(total cross-sectional area (A) of resin portions of the water-absorbent resin+total cross-sectional area (B) of hollow portions of the water-absorbent resin)}&#xd7;100%.

Water-absorbent resin, and soil

Provided is a non-destructive method for evaluating the structure of a water-absorbing resin which can be advantageously used for controlling various properties of the water-absorbing resin. This non-destructive method for evaluating the structure of a water-absorbing resin involves non-destructively evaluating the structure of a water-absorbing resin through an X-ray computer tomographic technique, wherein the method comprises a step 1 for installing the water-absorbing resin to be evaluated on a test piece stage of an X-ray computer tomography device, a step 2 for performing X-ray computer tomography on the water-absorbing resin using the X-ray computer tomography device and acquiring tomographic image data of the water-absorbing resin, and a step 3 for analyzing the tomographic image data using image analysis software and obtaining a tomographic image of the water-absorbing resin.

Non-destructive method for evaluating structure of water-absorbing resin

A water-absorbent resin that exhibits a high liquid-retention capacity under a load and a small amount of re-wet, even when it is used in an absorbent material having a low proportion of hydrophilic fibers. The water-absorbent resin includes a polymer of a water-soluble ethylenically unsaturated monomer, wherein when a cross-sectional image of the water-absorbent resin is observed using X-ray computed tomography, the water-absorbent resin has cavity area percentage in the cross-sectional image of 10% or less.

Water-absorbent resin and absorbent article

There is disclosed a method for producing water-absorbent resin particles, comprising a polymerization step that includes mixing an oily liquid comprising a hydrocarbon dispersing medium and a surfactant, and an aqueous liquid comprising an aqueous solvent and a water-soluble ethylenically unsaturated monomer, forming a suspension comprising an oily liquid and an aqueous liquid dispersed in the oily liquid, and polymerizing the water-soluble ethylenically unsaturated monomer in the suspension. The HLB of the surfactant is 6 or greater, and the temperature of the suspension is kept at 35&#xb0; C. or higher during the period from initial mixing of the oily liquid and aqueous liquid until complete mixing of the entire amounts.

Method for producing water absorbent resin particles

Disclosed is a water-absorbent resin particle in which the water-absorption rate of physiological saline is 1 second to 15 seconds, the median particle size is 100 &#x3bc;m to 600 &#x3bc;m, and the residual volatile component content is 1.5% by weight or less.

Water absorbing resin particles, method for manufacturing water absorbing resin particles, absorption body, absorptive article, and water-sealing material

There is disclosed a method for producing water-absorbent resin particles comprising a step that includes reversed-phase suspension polymerization of a water-soluble ethylenically unsaturated monomer in a suspension containing a surfactant that comprises a surfactant that comprises a fatty acid ester of sorbitan or sorbitol, or derivative thereof, and a hydrocarbon dispersion medium. The fatty acid ester includes a lauric acid ester and at least one kind of other ester selected from the group consisting of palmitic acid esters, stearic acid esters and behenic acid esters. The proportion of the peak area for lauric acid ester is 30-60%, based on the total peak area for fatty acid esters in the GPC chromatogram obtained from the fatty acid esters, and the proportion of the total peak area for other ester is 10-50%.

Method for producing water-absorbent resin particles

The present invention provides a method for producing water-absorbent resin particles which show an excellent water absorption rate and high equilibrium swelling capacity and which have an appropriate particle size to be excellent in handleability, and water-absorbent resin particles obtained by the method. The present invention is a method for producing water-absorbent resin particles by reversed phase suspension polymerization of a water-soluble ethylenically unsaturated monomer, the method including the steps of: (A) first reversed phase suspension polymerization of a water-soluble ethylenically unsaturated monomer in a petroleum hydrocarbon dispersion medium using a water-soluble radical polymerization initiator, in the absence of an internal crosslinking agent and in the presence of a surfactant having an HLB of 8 to 12; (B) intermediate crosslinking reaction by adding an intermediate crosslinking agent; (C) second reversed phase suspension polymerization of a water-soluble ethylenically unsaturated monomer added to the petroleum hydrocarbon dispersion medium containing the surfactant dissolved therein using a water-soluble radical polymerization initiator in the absence of an internal crosslinking agent, thereby producing a water-absorbent resin precursor; and (D) post crosslinking reaction of the water-absorbent resin precursor preliminary adjusted to have a moisture content of 30 to 100% by mass relative to a water-soluble ethylenically unsaturated monomer component in the water-absorbent resin precursor.

Method for producing water-absorbent resin particles and water-absorbent resin particles

An object of the present invention is to provide a method for manufacturing a sulfolene compound, the method being capable of inhibiting generation of polymers. Another object of the present invention is to provide a method for manufacturing a sulfolane compound, the method being capable of controlling inhibition of hydrogenation catalyst activity and smoothly hydrogenating a sulfolene compound. The present invention is a method for manufacturing a sulfolene compound represented by a formula (2), which comprises the step of reacting a conjugated diene compound represented by a formula (1) with sulfur dioxide in the presence of a metallocene compound:  

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Himeji, Japan

Yuichi Onoda