Surgery – Means and methods for collecting body fluids or waste material – Absorbent pad for external or internal application and...
Reexamination Certificate
2001-06-19
2003-03-04
Ruhl, Dennis (Department: 3761)
Surgery
Means and methods for collecting body fluids or waste material
Absorbent pad for external or internal application and...
C604S372000
Reexamination Certificate
active
06528698
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to an absorbent article for absorbing and keeping a liquid waste such as menstrual blood and, more particularly, to an absorbent article having both functions to permeate the liquid and to prevent the liquid return, and having a high concealing (hiding) property of the menstrual blood absorbed by an absorbent layer.
2. Related Art
Conventionally, an absorbent article such as a sanitary napkin and a pantiliner is constructed to include a liquid-impermeable back sheet, a liquid-permeable top sheet and an absorbent layer sandwiched between the back sheet and the top sheet.
The liquid-permeable top sheet has used a nonwoven fabric formed of hydrophobic fibers or has been provided in a resin film with a plurality of holes for infiltrating the liquid. Alternatively, in Japanese Unexamined Patent Publication (Kokai) No. Heisei 7-328061, there is disclosed a top sheet in which the resin layer (i.e., a plastic film) is formed in a plurality of band-shaped rows in parallel at an interval on the liquid receiving side surface of a nonwoven fabric containing hydrophobic fibers.
The aforementioned structure, in which the top sheet is formed of the nonwoven fabric of the hydrophobic fibers, is excellent in that it can introduce a liquid even in a high quantity promptly into the absorbent layer. However, this structure is defective in that the top sheet tends to infiltrate the liquid having been absorbed in the absorbent layer therethrough to return it to the skin of the wearer, when the body pressure is applied to the top sheet.
On the other hand, in the structure in which the top sheet is formed of a resin film having holes, the liquid absorbed in the absorbent layer hardly returns to the skin of the wearer, and it is possible to enhance the concealing (hiding) property of making the liquid absorbed in the absorbent layer invisible from the liquid receiving side by whitening the film. However, the top sheet of the resin film tends to closely contact with the wearer's skin, thereby to provide uncomfortable feeling and make the wearer feel wet to cause the stuffiness.
If the top sheet having a resin layer, which is applied to the surface of a nonwoven fabric in a plurality of band-shaped rows is used as described in Japanese Unexamined Patent Publication (Kokai) No. Heisei 7-328061, the return of the liquid from the absorbent layer can be prevented by the band-shaped rows formed in parallel, and both the band-shaped rows of the resin layer and the nonwoven fabric can abut against the wearer's skin to reduce feeling of closely contact.
However, in order to enhance the return preventing effect of the liquid from the absorbent layer and the concealing effect of the blood absorbed in the absorbent layer, it is necessary to narrow the interval of the band-shaped rows and increase the occupied area of the band-shaped rows of the resin layer in the top sheet. However, if the interval of the band-shaped rows is excessively narrowed, the ability of the top sheet to infiltrate the liquid is degraded to avoid passing the liquid promptly.
On the other hand, the structure having the continuous band-shaped rows is inferior in the softness of the top sheet so that the top sheet provides a stiff or hard feel. Furthermore, it encounters the problem that the top sheet is hardly deformed along the protrusion of the central region covering the absorbent layer, when the central region of the absorbent article (i.e., the region covering the absorbent layer) is shaped to protrude toward the wearer's skin.
SUMMARY OF THE INVENTION
An object of the invention is to provide an absorbent article which is enabled to suppress the return of a liquid from an absorbent layer by band-shaped rows of a resin layer, which can improve the concealment of menstrual blood absorbed by the absorbent layer, which is excellent in a liquid infiltration as the entire top sheet and which can provide softness of the top sheet.
According to an aspect of the invention, an absorbent article may comprise: a back sheet; an absorbent layer; and a top sheet covering at least the absorbent layer,
wherein the top sheet includes a fiber layer, and a resin layer which is applied to the surface of the fiber layer in a plurality of band-shaped rows, at least one of the rows being a discontinuous row composed of discontinuous band-shaped portions arranged at a spacing in the axial direction of the row, and the area not having the resin layer between adjacent discontinuous band-shaped portions in the axial direction of the row is located at least in the region covering the absorbent layer, so that the top sheet is liquid-permeable between the adjacent rows and in the area not having the resin layer between adjacent discontinuous band-shaped portions in the axial direction of the row.
On the other hand, some of the band-shaped rows, other than the discontinuous rows may extend continuously in the axial direction as continuous rows.
In this case, it is preferable that the continuous rows are disposed in two side regions of the absorbent article, which lie opposite one another in the transverse direction, and the discontinuous rows are disposed in a central region sandwiched between the two side regions.
On the other hand, at least one of the continuous rows may be formed between adjacent discontinuous rows.
Alternatively, only the discontinuous row may be formed on the top sheet.
In the invention having the band-shaped rows of the resin layer, it is possible to prevent the liquid having been absorbed by the absorbent layer from returning and to enhance the visual concealment of the liquid having been absorbed by the absorbent layer. Furthermore, by providing the discontinuous rows composed of the discontinuous band-shaped portions, it is possible to enhance the infiltration of the liquid thereby to infiltrate the liquid promptly. With these discontinuous band-shaped portions, the top sheet is made soft to give a smooth feel to the skin. On the other hand, the top sheet can be readily deformed along the protrusion of the central region covering the absorbent layer, when the central region of the absorbent article (i.e., the region covering the absorbent layer) is shaped to protrude toward the wearer's skin.
On the other hand, it is preferable that a hole passing through the fiber layer forming the top sheet is formed between adjacent discontinuous band-shaped portions in the axial direction of the row. With these holes being formed, it is possible to enhance the liquid infiltration function of the top sheet.
On the other hand, it is preferable that the holes have a diameter larger than the width of the discontinuous rows, and that the holes have a diameter larger than the array pitch of the discontinuous rows.
If the relation between the diameter of the holes and the width of the discontinuous rows is thus set, a part (an end) of the discontinuous band-shaped portion is extended into the inner wall portion.
When a part of the discontinuous band-shaped portion is extended into the inner wall portion of the hole, the liquid fed to the surface of the top sheet is easily introduced along the surface of the discontinuous band-shaped portions into the holes so that it can be less left on the surfaces of the band-shaped rows.
On the other hand, it is preferable that the top sheet has a portion protruding toward the absorbent layer around the edge of each hole, and a part of the discontinuous band-shaped portion is extended and fused to the fiber layer at the tip of the protruding portion.
With this construction, it is possible to increase the force of retaining the shape of the holes so that the holes are hardly crushed to be closed.
On the other hand, at least one of the discontinuous row and the continuous row has an irregular surface. In such a construction, the substantially contact area with the skin of the wearer can be reduced to avoid closely contact with the skin. On the other hand, the irregular light reflection may be caused on the surface o
Mizutani Satoshi
Ota Akiko
Tamura Tatsuya
Anderson C L.
Darby & Darby
Ruhl Dennis
Uni-Charm Corporation
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