Diaper closure utilizing pressure-sensitive adhesive tape having textured foil backing

In the combination of a diaper and, adhered to one exterior surface thereof, at least one closure tab comprising a strip of sheet material having a coating of normally tacky and pressure-sensitive adhesive firmly bonded to one face thereof,

• the improvement comprising said sheet material's being a substantially untensilized, tough, ductile foil of crystalline polypropylene or linear polyethylene having a fine grain crystal structure and a calipered thickness of about 100-500 micrometers, said foil having one smooth face and one textured face, the textured face having a pattern of ridges separated by valleys,
• (a) the average distance between the crests of adjacent ridges being about 250-1,500 micrometers,
• (b) none of said crests being more than either
• (1) 100 micrometers or
• (2) 2/3 the calipered thickness of the foil below the highest crest,
• (c) the thickness of the foil between the bottom of the valleys and said smooth face being at least about 25 micrometers but not more than about 2/3 the calipered thickness,
• (d) the void volume included on the textured face of said foil constituting about 10-60% of the apparent volume of said foil,
• at least some of the ridges extending at an angle of 60.degree. or less to the lateral edge of the closure tab and having a length significantly greater than any valleys they block,
• said tab being further characterized by having a tensile strength at yield of 2.5 kg/cm width, a stiffness value of no more than about 3 gm-cm perpendicular to its long dimension and no more than about 5 gm-cm parallel to its long dimension so that it is readily conformable, and a tear propagation value perpendicular to its long dimension of at least 100 grams so that it resists inadvertent edge tear resulting from tensile forces even when nicked.