The invention provides a method for producing a water-absorbent resin, and a water-absorbent resin obtained by this method, more particularly, this invention provides a method for producing a water-absorbent resin by a reverse phase suspension polymerizing process. The water-absorbent resin produced by this invention produces less odd smell originated from raw material components, more particularly from petrol hydrocarbon dispersion catalyst, than that is available from conventional techniques. More specifically, the method of this invention is a method for making a water-absorbent resin by reverse phase suspension polymerizing a water soluble ethylenic unsaturated monomer in a petrol hydrocarbon dispersion catalyst under the presence of a surfactant by adding an aqueous solution of a water soluble ethylenic unsaturated monomer, which contains a hydrophilic polymeric dispersion agent, in a petrol hydrocarbon dispersion catalyst and dispersing the water soluble ethylenic unsaturated monomer, and thereafter, performing the reverse phase suspension polymerizing by using a radical polymerizing initiator.本申請案係提供吸水性樹脂的製造方法及藉由該方法所得之吸水性樹脂,更詳細而言,藉由逆相懸浮聚合法製造吸水性樹脂之方法,其中原料成分,尤其是源自石油系烴分散媒之臭味與藉由以往技術所得之吸水性樹脂相比較為減少之吸水性樹脂的製造方法及藉由該方法所得之吸水性樹脂。更詳細而言,本申請案係提供將水溶性烯性不飽和單體於石油系烴分散媒中進行逆相懸浮聚合而製造吸水性樹脂之方法,對於石油系烴分散媒,在界面活性劑存在下,攪拌下添加含有親水性高分子系分散劑之水溶性烯性不飽和單體水溶液而分散後,使用自由基聚合起始劑進行逆相懸浮聚合之吸水性樹脂的製造方法及藉由該方法所得之吸水性樹脂。
