Satoru Sakaguchi, Kanonji, Japan.
Assigned to Unicharm Corporation, Ehime, Japan.

Filed: 11/27/13
Issued: 1/29/19

A disposable diaper, comprising: a front waistline region; a back waistline region; and a crotch region positioned between the front waistline region and the back waistline region; a product longitudinal direction oriented from the front waistline region to the back waistline region; a product widthwise direction orthogonal to the product longitudinal direction: an absorber running across the crotch region and extending to at least one of the front waistline region and the back waistline region; a pair of side flaps extending across the front waistline region, the crotch region, and the back waistline region, said pair of side flaps being disposed on opposite sides of the absorber in the product widthwise direction; and a pair of fastening tapes each extending, in the product widthwise direction, in the back waistline region outward of the pair of side flaps, respectively, said pair of fastening tapes being releasably attachable to the front waistline region; wherein each side flap of the pair of side flaps has: a lateral edge including an leg opening unit concave toward a center of the absorber in the product widthwise direction, said leg opening unit having a center in the product longitudinal direction; a leg stretching unit disposed inward of the leg opening unit in the product widthwise direction and stretchable in the product longitudinal direction; and a buttocks part stretching unit running across the crotch region and the back waistline region, and stretchable in the product longitudinal direction; the leg opening unit in said each side flap has: a backside leg opening unit positioned backward of the center of the leg opening unit in the product longitudinal direction; and a foreside leg opening unit positioned forward of the center of the leg opening unit in the product longitudinal direction, wherein an area between the backside leg opening unit and a straight line, which passes through the center of the absorber in the product widthwise direction and which is parallel to the product longitudinal direction, is larger than an area between the foreside leg opening unit and the straight line, and in said each side flap, said buttocks part stretching unit is disposed outward of the leg stretching unit in the product widthwise direction, a front end of the buttocks part stretching unit is positioned backward of the center of the leg opening unit in the product longitudinal direction and reaches the lateral edge of the side flap, and a plurality of convex units convex away from the absorber in the product widthwise direction is formed only in the backside leg opening unit and outward of the front end of the buttocks part stretching unit in the product widthwise direction.