Akinori Fukae, Ehime, Japan; Yosuke Mori, Ehime, Japan; and Aya Ide, Ehime, Japan.
Assigned to Daio Paper Corporation, Ehime, Japan.

Filed: 5/11/17
Issued: 2/14/23

An underpants-type disposable diaper, in which a front side outer member disposed in a front body and a back side outer member disposed in a back body are separately provided, the front side outer member and the back side outer member are spaced apart in a front- back direction at a middle in the front-back direction, an inner member, which has a liquid pervious top sheet positioned on a front surface side thereof, a liquid impervious sheet positioned on a back surface side thereof, and an absorber interposed therebetween, extends in the front-back direction from the front side outer member to the back side outer member, and is joined to the front side outer member and to the back side outer member, a first side gather and a second side gather extending from both sides of the inner member so as to be in contact with the legs of a wearer are included, each of the first side gather and the second side gather includes a root portion on a side portion on a back surface side of the liquid impervious sheet in the inner member and includes a gather nonwoven fabric forming an outer surface at least from the root portion to a tip end, a cover nonwoven fabric, which covers a back surface of the inner member, is provided from between the front side outer member and the inner member to between the back side outer member and the inner member, the cover nonwoven fabric extends at least from a back surface side of the root portion of the first side gather to a back surface side of the root portion of the second side gather, both sides of the front side outer member and both sides of the back side outer member are joined, respectively, a waist opening and a pair of right and left leg openings are included, and elastic members are incorporated in the front side outer member and the back side outer member, wherein the absorber has a front end portion, a back end portion, and a narrowed portion positioned between the front end portion and the back end portion and having a narrower width than that of the front end portion and that of the back end portion, wherein the cover nonwoven fabric is a perforated nonwoven fabric in which a plurality of holes penetrating a front surface and a back surface of the cover nonwoven fabric are provided at intervals entirely in the front-back direction and a width direction, wherein opposed side edges of the cover nonwoven fabric extend in the front-back direction and are located either coincident with or between opposed side edges of a narrowest part of the narrowed portion; and wherein side edge areas opposed in the width direction of the cover nonwoven fabric are non- fixed portions not fixed to the inner member, the first side gather, or the second side gather, and the portion between the non-fixed portions of the cover nonwoven fabric is a fixed portion fixed to the inner member.