PROBLEM TO BE SOLVED: To provide an underpants type disposable diaper in which joints at both ends of front and back bodies have high joint strength when a user wears the diaper and can be easily ruptured in the disposal of the diaper.SOLUTION: When both ends of front and back bodies of a diaper are joined together, joint strength of a lower joint area 42, in which a small number of sheet members overlap one another, can be enhanced by: forming the lower joint area and an upper joint area in such a shape that the lower joint area 42, in which the small number of sheet members overlap one another, is wider than an upper joint area 44, in which a large number of sheet members overlap one another and forming each of the upper and lower joint areas 41 and 42 from a plurality of seal part lines like short lines elongated in the horizontal direction of the diaper. In the disposal of the diaper, the joints can be easily ruptured. The underpants type disposable diaper is based on the above findings.COPYRIGHT: (C)2013,JPO&INPIT【課題】前身頃と後身頃の両端を接合部が,おむつの着用時には強固な接合強度を有しており,おむつの廃棄時には簡単に破断させ易くなっているパンツ型の使い捨ておむつを提供する。【解決手段】おむつの前身頃と後身頃の両端を接合するにあたり,重ね合わされたシート部材の数が少ない下部接合領域42の幅を,重ね合わされたシート部材の数が多い上部接合領域44の幅よりも幅広に形成し,しかも,上部接合領域41と下部接合領域42のそれぞれを,おむつの左右方向に延びる短線状の複数のシール部の列によって形成することにより,重ね合わされたシート部材の数が少ない下部接合領域42の接合強度を向上させることができ,かつ,おむつの廃棄時には接合部を破断させ易くなるという知見に基づく。【選択図】図3
