JPH0793936B2 - Sanitary napkin - Google Patents

Description

TECHNICAL FIELD The present invention relates to a sanitary napkin, and more particularly to a sanitary napkin having reduced absorption characteristics, particularly lateral leakage.

[Conventional technology and problems]

BACKGROUND ART Conventionally, research aimed at improving the absorption characteristics of absorbent articles such as sanitary napkins has been carried out, and many results have been reported. Most of the goals are to improve the absorption rate, prevent the liquid from returning from the absorbing layer after absorbing the liquid to the surface, and reduce the stickiness on the surface.

To give a concrete example, first of all, regarding research on the surface layer, there was stickiness on the surface because rayon staple, which has been generally used conventionally, is a hydrophilic material. It has been proposed to change this to a hydrophobic material such as polypropylene staple or polyester staple to reduce the stickiness of the surface.

Also, as a material for the absorbent layer, the absorbent capacity is improved by applying a polymer absorbent material (super absorbent polymer) which has improved the holding power after absorption of conventional absorbent paper and cotton-like pulp, At the same time, it has been proposed to prevent liquid return to the surface layer after absorption. In fact, these proposals have greatly improved the water absorption capacity itself.

Therefore, it can be said that the problem of leakage due to the shortage of absorption capacity has been considerably solved. Further, since the holding power due to the absorption and swelling of the superabsorbent polymer is overwhelmingly higher than that of the conventional absorbent paper and cotton-like pulp, the effect is great if it is effectively absorbed, and the feeling of use to the user, especially the stickiness ( The liquid return to the surface after absorption is reduced, and its benefit is great.

Therefore, it can be said that the research goal of the sanitary napkin was focused on how to effectively function the superabsorbent polymer. And the result is Japanese Examined Sho 57-5656
No. 1 and Japanese Patent Publication No. 57-6946.

However, the present inventors believe that no matter how effectively these materials such as superabsorbent polymers are made to function, their absorption properties are still insufficient, and the problem of lateral leakage has not been solved. That is, at the time of absorbing menstrual blood, the deformation with respect to the pressure applied at the time of wearing between the groins is large, and as a result, it causes lateral leakage.

This state is apparent from the napkin shape after mounting as shown in Fig. 3, and most of the leaks in the state of being set in this deformation (this is called twisting), especially from the center side. Occupy. In other words, when the sanitary napkin is in a wet state after absorbing blood, the center of the sanitary napkin is twisted due to the pressure between the groins such as its legs closed, walking, etc. It is considered that, as a result, the leakage occurred while leaving the unabsorbed portion.

Therefore, various proposals have been made as means for solving these problems.

In Japanese Utility Model Publication No. 60-24339, "A material consisting of absorbent paper or a combination of this and crushed pulp is arranged in the central region, and crushed pulp or a material mainly composed of this is arranged in both side zones thereof. The napkin is characterized by the fact that it is characterized by the fact that the napkin after absorption as described above and the twist are not solved at all, and a sufficient effect cannot be expected.

Furthermore, a number of napkins having concave cuts on the side of the absorbent layer have been proposed with the idea of improving fit by matching the shape of the crotch when worn and the shape of the absorbent layer as much as possible (Actual publication: Sho 60). -25237, Jitsuho Sho 60-31718, etc.)

However, when a part of the absorption layer is notched in a concave shape, the absorption capacity only lowers the absorption capacity of a necessary portion, which causes lateral leakage.

In addition to the above, a method of forming a core material having a shape-retaining property in the center of the absorbent layer to prevent the absorbent layer from being deformed (Shokai Sho 56-60
No. 99 gazette) has been proposed, but the napkin is most deformed during mounting as shown in FIG. 3 at both ends in the short side direction. The twist of the napkin is increased by constructing the shape retention piece without decreasing, which results in a feeling of discomfort to the user.

[Means for solving problems]

Therefore, in view of the above-mentioned problems, the inventors of the present invention prevent deformation and twist during use without impairing the feeling of use, and
By improving the fit to the pubic area and crotch area,
As a result of intensive research on a sanitary napkin that effectively prevents lateral leakage, the present invention has been achieved.

That is, the present invention provides a substantially rectangular sanitary napkin having a liquid-permeable surface layer, a liquid-impermeable leak-proof layer, and an absorption layer located between the two layers, in the short side direction of the absorption layer. The present invention provides a sanitary napkin characterized in that elastic bodies are provided at both ends.

According to the present invention, it has become possible to remarkably reduce the twist and settling of the sanitary napkin and to exhibit a high leak preventive effect.

The present invention will be described in more detail below with reference to the drawings.

FIG. 1 is a model cross-sectional view showing various embodiments of the sanitary napkin of the present invention, wherein 1 is a liquid-permeable surface layer, 2 is an absorbent layer, 3 is a liquid-impermeable leak-proof layer, and 4 Is an elastic body. 1 (a) and 1 (b) are examples in which the absorption layer 2 is composed of a single layer, and in FIGS. 1 (c) and 1 (d), the absorption layer is provided on the first absorption layer 2 and its surface layer 1 side. In this example, the second absorption layer 2'is narrower than the first absorption layer.

The elastic body of the present invention is not particularly limited as long as it has a deformation recovery property, and examples of suitably used elastic bodies include flexible and highly recoverable foams such as expanded polyethylene, expanded polyurethane and expanded polybutadiene. In addition to the sheet-like material, a sheet-like material or laminate of rubber, polyolefin, polyurethane, polybutadiene elastomer resin, and a sheet made of synthetic fibers (polyethylene, polypropylene, polyester, composite fiber such as ES fiber, acrylic, etc.) Examples thereof include those having a buckling strength (defined in Example 1 below) of 10 to 300 g.

If the buckling strength is less than 10 g, the compression resistance will be small and the anti-twisting effect will be insufficient, and if it exceeds 300 g, the resistance will be too strong and will give an uncomfortable feeling when mounted, which is not preferable.

FIG. 2 is a plan view showing a preferable position where the elastic body of the sanitary napkin of the present invention is provided, but in the present invention, the elastic body 4 may be provided at any of both ends in the short side direction, There is no restriction in the thickness direction. Particularly, it is preferable that a part of the elastic body 4 is on the center line y in the long side direction. Furthermore, it is desirable that the elastic body is inseparably fixed to the absorbent layer in the structure of the sanitary napkin, and the shape-retaining effect is exhibited by being integrated with the absorbent layer.

In the present invention, the size of the elastic body is not particularly limited, but the length w in the long side direction (x direction in FIG. 2) is 10
mm or more, preferably 30 mm to 160 mm, and the length m in the short side direction (y direction in FIG. 2) is 3 mm or more, preferably 10 mm to 35 mm.

〔Example〕

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

Example 1 A 20 g / m ² polyolefin non-woven fabric (having a polyethylene-polypropylene composite fiber / polyester weight ratio of 70/30) as a liquid-permeable surface layer, and a cotton-like pulp (1
80g / m ² ), absorbent paper (33g / m ² , 3ply) and super absorbent polymer 0.3g, polyethylene laminated paper as liquid impermeable leakproof layer, to which various elastic materials shown in Table-1 are added. , (A) and (c) of FIG. 1, two types of sanitary napkins were obtained, and these were used as test samples.

The dynamic maximum absorption amount and the uncomfortable feeling were measured for these test samples by the following methods.

The results are shown in Table-1.

Dynamic maximum absorption amount As shown in FIG. 4, the test sample 7 was attached to the movable female waist model 5 as shown in FIG. 5, shorts were put on, and running motion was performed at a speed corresponding to 50 m / min. Simultaneously, pseudo blood was injected through the dropping tube 6 and the amount absorbed was measured before the occurrence of sideways leakage.

Discomfort 20 women were asked to wear the test sample, had them do normal activities for 1 hour, and then asked the following to determine the feeling of wearing the test sample.

○: No discomfort △: There is some discomfort, but it does not bother me.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing various embodiments of the sanitary napkin of the present invention, FIG. 2 is a plan view showing a constitutional position of an elastic body in the sanitary napkin of the present invention, and FIG. 3 is a conventional sanitary napkin. FIG. 4 is a perspective view showing a deformed state of both ends in the short side direction at the time of mounting, FIG. 4 is a perspective view of a movable female waist model, and FIG. 5 is a perspective view showing a state in which a test sample is mounted thereon. 1 ... Liquid-permeable surface layer 2 ... Absorption layer 3 ... Liquid-impermeable leak-proof layer 4 ... Elastic body 5 ... Movable female lumbar model 6 ... Liquid injection tube 7 ... Test sample

Claims (3)

[Claims] 1. A substantially rectangular sanitary napkin having a liquid-permeable surface layer, a liquid-impermeable leak-proof layer, and an absorbent layer located between the two layers. A sanitary napkin characterized in that an elastic body is provided in the. 2. The sanitary napkin according to claim 1, wherein the elastic body is provided at the center of the long side. 3. The sanitary product according to claim 1, wherein the absorbent layer comprises a first absorbent layer and a second absorbent layer provided on the surface layer side thereof and narrower than the first absorbent layer. napkin.