Sumitomo Seika Chemicals Co., Ltd.

Mikito Chiba

Yuichi Onoda

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.

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Himeji, Japan

Mikito Chiba