US Patent No.: 8,574,211 B2
Inventor(s): Shinnosuke Morita, Tochigi, Japan; Kenji Ando, Tochigi, Japan; Kenji Ishiguro, Tochigi, Japan; and Manabu Matsui, Tochigi, Japan.
Company: Kao Corporation, Tokyo, Japan.
A stretchable composite sheet comprising a stretch sheet and a nonstretch sheet laminated with the stretch sheet and having a first direction and a second direction perpendicular to the first direction, the stretch sheet having a first zone with elastic stretchability and a second zone with less elastic stretchability than that of the first zone, the first and the second zones extending in the first direction and alternate in the second direction, the stretch sheet and the nonstretch sheet being bonded to each other on their facing sides, the stretchable composite sheet as a whole having stretchability in at least the second direction, and the stretchable composite sheet having, in a natural, relaxed state, a large number of ridges extending in the first direction on the nonstretch sheet side in a portion where the stretch sheet and the nonstretch sheet are bonded to each other over substantially the entire area; wherein a pitch of the ridges is 0.5 to 5 mm and a height of the ridges is 0.5 to 5 mm; wherein the stretch sheet comprises an extensible nonwoven fabric and a large number of elastic filaments bonded to the nonwoven fabric in their substantially nonstretched state over the whole length thereof, the elastic filaments being arranged to extend in the same direction without intersecting with each other, and the stretch sheet having stretchability in the direction in which the elastic filaments extend; wherein the direction in which the elastic filaments extend is perpendicular to the first direction; wherein the stretchable composite sheet has second ridges that protrude on the opposite side of the ridges and on the side that the nonstretch sheet is not bonded; and wherein the second ridges extend in the same direction as the ridges, are formed between the ridges that the second ridges are adjacent to, and are shorter than the height of the ridges.