Sanitary napkin with compressed grooves

• US 7,196,241 B2
• Filed: 05/07/2004
• Issued: 03/27/2007
• Est. Priority Date: 05/29/2003
• Status: Active Grant

• Current Assignee: Unicharm Corporation
• Original Assignee: Unicharm Corporation
• Inventors: Nishitani, Kazuya, Tanio, Toshiyuki, Sakai, Akane, Kinoshita, Masataka
• Primary Examiner(s): Zalukaeva; Tatyana
• Assistant Examiner(s): Bogart; Michael G.
• Application Number:
  US10/841,386
• Publication Number:
  US 20040243082A1
• Time in Patent Office: 1,054 Days
• Field of Search: 604/379, 604/380, 604/385.01, 604/385.03, 604/385.24, 604/386, 604/387
• US Class Current: 604/380
• CPC Class Codes: A61F 13/4704 having preferential bending zones, e.g. fold lines or grooves
• CPC Class Codes: A61F 13/47245 with asymmetry around the x or y axis
• CPC Class Codes: A61F 13/4752 the means being an upstanding barrier
• CPC Class Codes: A61F 13/4756 the means consisting of grooves, e.g. channels, depressions or embossments, resulting in a heterogeneous surface level
• CPC Class Codes: A61F 13/476 characterised by encircling the crotch region of the undergarment

Abstract

A sanitary napkin in which diffusing liquid hardly reaches a rear end edge is adapted to make a liquid absorbent layer less deformable in a rear region so that it can easily be kept in close contact with the wearer'"'"'s buttocks. The sanitary napkin has an elongated main absorbent region surrounded by compressed grooves that are formed in a skin-side surface. Since a rear end of the main absorbent region is far away from a rear end edge of the napkin to provide a relatively large rear region, worries about rearward leakage may be relieved. Furthermore, since auxiliary longitudinal grooves are provided in the rear region, a liquid absorbent layer may hardly be twisted.

Claims

1. A sanitary napkin comprising:

an elongated main body having a skin-side surface and a garment-side surface and including a liquid-permeable topsheet appearing on the skin-side surface, a backsheet appearing on the garment-side surface, and a liquid absorbent layer disposed between the topsheet and the backsheet;

leakage preventing walls disposed at substantially equal distances on each side of a longitudinal centerline of the main body and extending longitudinally of the main body, the leakage preventing walls exhibiting an elastic contractive force so as to rise from the skin-side surface; and

compressed grooves, where the liquid absorbent layer is compressed together with the topsheet, being formed in a region of the main body between the leakage preventing walls, the compressed grooves comprising;

primary longitudinal grooves disposed at substantially equal distances on each side of the longitudinal centerline of the main body, the primary longitudinal grooves extending longitudinally of the main body and defining a main absorbent region therebetween;

a primary transverse groove disposed between rear portions of the primary longitudinal grooves, the primary transverse groove extending transversely of the main body and defining a rear end of the main absorbent region; and

auxiliary longitudinal grooves disposed at substantially equal distances on each side of the longitudinal centerline of the main body, wherein

the liquid absorbent layer has a rear end edge in a rear region that extends rearward from the rear end of the main absorbent region to a rear end edge of the main body, and the auxiliary longitudinal grooves extend longitudinally of the main body from regions transversely adjacent the main absorbent region to the rear region so that the auxiliary longitudinal grooves in the rear region are transversely spaced more than the primary longitudinal grooves,

the compressed grooves further comprise an auxiliary transverse groove disposed rearward of the primary transverse groove and between the auxiliary longitudinal grooves, wherein a rearward diffusion suppressing region rearward of the rear end of the main absorbent region is defined between the primary transverse groove and the auxiliary transverse groove, and the auxiliary longitudinal grooves have rear ends rearward of a rear end of the rearward diffusion suppressing region.

2. A sanitary napkin according to claim 1, wherein the individual auxiliary longitudinal grooves in the rear region extend parallel to the longitudinal centerline.

3. A sanitary napkin according to claim 1, wherein rear ends of the leakage preventing walls are located at substantially the same longitudinal position as or forward of the rear end of the main absorbent region.

4. A sanitary napkin according to claim 1, wherein rear ends of the leakage preventing walls are located at substantially the same longitudinal position as or forward of the rear end of the rearward diffusion suppressing region.

5. A sanitary napkin according to claim 1, further comprising:

fold-back flaps projecting outward from transversely opposite sides of the main body and configured to be folded back against and fixed to an outer surface of an undergarment at a crotch part thereof; and

rear flaps located rearward of the fold-back flaps, projecting outward from the transversely opposite sides of the main body to be placed on an inner surface of the undergarment in an unfolded state, wherein

the rear flaps are located outside the auxiliary longitudinal grooves.

6. A sanitary napkin according to claim 1, wherein L1/L0 is at least ⅔

, where L0 represents a length from the rear end of the main absorbent region to the rear end edge of the liquid absorbent layer while L1 represents a length from the rear end of the main absorbent region to the rear ends of the auxiliary longitudinal grooves.

7. A sanitary napkin according to claim 6, wherein L0 is equal to or greater than 50 mm.