Disposable diaper

A disposable diaper, comprising a liquid-permeable topsheet, a liquid-impermeable backsheet and a liquid-absorbent core disposed therebetween so as to form a front waist region, a rear waist region and a crotch region extending therebetween, and further comprising longitudinally opposite front and rear end flaps and transversely opposite side flaps which are formed by said topsheet and said backsheet extending outward from peripheral edges of said absorbent core,

• a pair of barrier cuffs being elastically extendable in a longitudinal direction of said diaper and being bonded, in an extended condition, to an inner surface of an associated one of said side flaps;
• each of said barrier cuffs having longitudinally opposite front and rear ends, and inner and outer side edges extending in parallel to each other between said front and rear ends;
• said front and rear ends of each of said barrier cuffs being respectively bonded to said front and rear end flaps;
• each of said barrier cuffs has, in said crotch region, said outer side edge bonded to said associated side flap and said inner side edge bonded to said associated side flap along a line defined between said outer side edge and an associated edge of said absorbent core;
• each of said barrier cuffs has, in a transverse cross-sectional view and in the crotch region,
• a first wall section formed with a plurality of elastic members and which first wall section extends inwardly from the outer side edge of said barrier cuff, an outermost one of said elastic members being spaced and distinct from said bonding of the outer side edge of said barrier cuff and the associated side flap, and
• a second wall section intersecting the first wall section inwardly of an innermost one of said elastic members and extending downward to the inner side edge of said barrier cuff,
• wherein a dimension of said first wall section in a transverse direction thereof is larger than that of said second wall section in said transverse direction, and
• said first and second wall sections, together with a portion of said associated side flap defined between said outer and inner side edges, describe a hollow space of a substantially triangular shape, under contraction of said barrier cuff in the longitudinal direction;
• and
• portions of said barrier cuffs and said side flaps participating in the formation of said triangular hollow spaces are air-permeable;
• wherein
• a sum of the transversely extending dimensions of said first and second wall sections is greater than a dimension of a portion of the associated side flap defined between the inner and outer edges of the associated barrier cuff;
• and
• said plurality of elastic members include at least three elastic members, the innermost elastic member has an extension stress less than an extension stress of the outermost elastic member, and an extension stress of the elastic member or members disposed between the innermost and outermost elastic members is less than the extension stress of the innermost elastic member.