Disposable diaper

A disposable diaper comprising:

• (A) an outer member having front and back waist sections located at the front and back end portions of the outer member and a pair of crotch sections each having an inwardly indented portion by which a crotch opening is formed when side edge portions of the front waist section are connected to side edge portions of the back waist sections, and comprising (a) an outermost sheet layer capable of elongation in a transverse direction of the diaper and (b) a pair of side liner sheet layers covering both side portions of the outermost sheet layer and extending along a longitudinal direction of the diaper;
• and
• (B) a liquid absorbent member arranged on a middle portion of the outer member, extending along the longitudinal direction of the diaper, and comprising (c) a liquid non-permeable back sheet layer located on a middle portion of the outermost sheet layer (a), (d) a liquid permeable top sheet layer superposed on the liquid non-permeable back sheet layer (c), and (e) a liquid absorbent pad layer interposed between the liquid non-permeable back sheet layer (c) and the liquid permeable top sheet layer (d),
• wherein
• each of the side liner sheet layers (b) consists of a composite sheet which consists of (i) an elastic sheet ply capable of expansion and contraction in the transverse direction of the diaper and (ii) at least one non-elastic sheet ply laminated on at least one surface of the elastic sheet ply (i) and capable of elongation in the transverse direction of the diaper,
• the composite sheet for the side liner sheet layers (b) exhibits an elastic stress of 300 g/25 mm or less under an elongation of 50% in a direction in which the elastic sheet ply is capable of expansion and contraction, and a recovery of 80% or more from the elongation when the elastic stress is released,
• the elastic sheet ply (i) of the composite sheet consists of an elastic, non-porous polyurethane resin film having a moisture-permeability of 2000 to 6000 g/m.sup.2 .multidot.24 hr, and the non-elastic sheet ply (ii) consists of a nonwoven fabric, and
• a non-elastic intermediate sheet layer is interposed between a middle portion of the outermost sheet layer (a) and the liquid absorbent member (B) and connected to the side liner sheet layers (b).