PROBLEM TO BE SOLVED: To provide an underpants type absorbent article which has an outerwrap material split into abdominal-side and back-side sheet members and which enables easy discrimination between front and rear sides of a diaper while being the efficiently manufacturable underpants type absorbent article.SOLUTION: The underpants type absorbent article 1 includes the abdominal-side and back-side sheet members 2A and 2B, and a longitudinally long absorbent body 3. Side edges of both the sheet members 2A and 2B are provided with joint portions 2a and 2b which form side seal portions, and non-joint portions 2a" and 2b" which are positioned on lower extensions thereof. The absorbent body 3 includes an absorber 33 and a lateral sheet portion 34, and the lateral sheet portion 34 has an expansion/contraction area 34c which is expanded/contracted by an elastic member 36. Both the sheet members 2A and 2B comprise abdominal-side and back-side expansion/contraction portions 36a and 36b which are joined to the expansion/contraction area 34c and expanded/contracted together with the expansion/contraction area 34c. A length L1, along the longitudinal direction of the absorbent body 3, of the abdominal-side expansion/contraction portion 36a is longer than a length L2, along the longitudinal direction of the absorbent body 3, of the back-side expansion/contraction portion 36b.COPYRIGHT: (C)2012,JPO&INPIT【課題】外包材が腹側シート部材と背側シート部材とに分割され、効率的に製造可能なパンツ型吸収性物品でありながら、おむつの前後を容易に判別することのできるパンツ型吸収性物品を提供すること。【解決手段】パンツ型吸収性物品1は、腹側シート部材2A、背側シート部材2B及び縦長の吸収性本体3を具備し、両シート部材2A,2Bは、それぞれの側縁部に、サイドシール部を形成している接合部2a’,2b’と、その下方延長線上に位置する非接合部2a”,2b”とを有する。吸収性本体3は、吸収体33及び側部シート部34を有し、側部シート部34は、弾性部材36により伸縮する伸縮領域34cを有している。両シート部材2A,2Bは、伸縮領域34cが接合されて伸縮領域34cと共に伸縮する腹側及び背側伸縮部36a,36bを有し、腹側伸縮部36aは、吸収性本体3の長手方向に沿う長さL1が背側伸縮部36bの同長さL2より長い。【選択図】図2
