While having a high equilibrium swelling performance and and combines the initial swelling performance and fast absorption rate excellent method for producing a water-absorbent resin particles handling is good particle size is moderate, the present invention is obtained by that to provide an absorbent article and water sealing material using water-absorbing resin particles, the water-absorbing resin particles. Absence of internal crosslinking agent, the present invention, the water by the presence of a surfactant 8~12, HLB in the reverse phase suspension polymerization in a hydrocarbon solvent, a water-soluble ethylenically unsaturated monomer preparing a gel-like polymer, and, in 30 to 110% by mass relative to the water-soluble ethylenically unsaturated monomer component constituting the hydrogel polymer, the moisture content of the hydrogel polymer After the adjustment, the method including the water-absorbent resin particles having the step of post-crosslinking reaction.本発明は、高い平衡膨潤性能を有しながら、優れた吸水速度及び速い初期膨潤性能を併せ持ち、かつ、粒径が適度でハンドリング性が良好である吸水性樹脂粒子の製造方法、それにより得られる吸水性樹脂粒子、該吸水性樹脂粒子を用いた止水材及び吸収性物品を提供する。本発明は、水溶性エチレン性不飽和単量体を、内部架橋剤の非存在下、HLBが8~12の界面活性剤の存在下、炭化水素溶媒中で逆相懸濁重合することにより含水ゲル状重合体を調製する工程、及び、前記含水ゲル状重合体の水分率を、前記含水ゲル状重合体を構成する水溶性エチレン性不飽和単量体成分に対して30~110質量%に調整した後、後架橋反応させる工程を有する吸水性樹脂粒子の製造方法である。
