Provided are a water-absorbent resin easily separable from a recyclable resource in recovering the recyclable resource, and an absorbent article containing an absorbent material containing the water-absorbent resin. The water-absorbent resin according to the present invention has such a structure that a polymer formed from a water-soluble ethylenically unsaturated monomer is crosslinked by using a post-crosslinking agent. The water-absorbent resin has (1) a water-retention capacity for physiological saline of 35 g/g or more, (2) a water-absorption capacity for physiological saline under a load of 4.14 kPa of 10 mL/g or more, (3) an initial gel viscosity of 3000 mPa.Math.s or more, and (4) a gel decomposition index of 0.60 or less: gel decomposition index=B/A wherein A represents an initial gel viscosity (mPa.Math.s), and B represents a gel viscosity after one day (mPa.Math.s).

Disclosed is an absorbent article with biocompostable properties, such as a baby diaper, adult incontinence product, or a feminine hygiene pad. Particularly, the present invention is directed to a biocompostable absorbent sanitary article with a high degree of biocompostability. The sanitary article comprises, in one embodiment, at least a top layer, a back layer, and absorbent core, wherein the absorbent core includes a superabsorbent polymer, and wherein at least the superabsorbent polymer is biocompostable.

An AHP is disclosed having a topsheet, a backsheet joined with the topsheet, an absorbent core, disposed between the topsheet and the backsheet, and a poly(acrylic acid)-based superabsorbent polymer (SAP), partly derived from recycled resources. The SAP exhibits defined Saline Flow Conductivity and Absorption Against Pressure values. Methods for making the aforementioned AHP are also disclosed.

Disclosed is water-absorbent resin particles, in which a value of non-pressurization DW after 3 minutes is 14 ml/g or more, and a value of liquid suction power after 3 minutes measured by the following method is 11 ml/g or more. A liquid suction power measurement method: 0.3 g of the water-absorbent resin particles is uniformly dispersed in a cylindrical container having a mesh-like bottom and having an inner diameter of 26 mm; the cylindrical container is placed in a container containing 40 g of a physiological saline solution, the water-absorbent resin particles are caused to absorb the physiological saline solution for 30 minutes from the bottom of the cylindrical container, and thereby a swollen gel is obtained; and non-pressurization DW, which is measured in a state where another 0.3 g of the water-absorbent resin particles is uniformly dispersed on the swollen gel in the cylindrical container, is defined as liquid suction power.