CN201029993Y - absorbent article - Google Patents

Abstract

An absorbent article (1) having an absorbent layer (A) formed by laminating a top sheet (2) made of a bulky nonwoven fabric and an absorbent sheet (4) with low compression set, wherein the absorbent layer The side of the skin contacting surface of (A) is provided with an anti-leakage groove (6) extending in a continuous linear shape when viewed from above. The anti-leakage groove (6) is formed by compressing the absorbent layer (A) along the thickness direction so that the front sheet (2) and the absorbent sheet (4) are integrated, and at least the front sheet (2) is depressed. And formed. On the front sheet (2), high compression parts (62) and low compression parts (61) are alternately arranged in the extension direction of the leak-proof groove (6), from the low compression part (61) toward the high compression part (62) ) forms a density gradient. According to the absorbent article of the present invention, since the leak-proof groove is provided on the absorbent layer by compression processing, even when the liquid is repeatedly absorbed and a large amount of liquid is absorbed in a short time, the liquid absorbed in the absorbent layer has excellent Diffusion.

Description

absorbent article

technical field

The utility model relates to absorbent articles such as sanitary napkins for physiological use, underwear linings, sanitary pads, and incontinence pads.

Background technique

As a prior art, it is known to provide anti-leakage grooves by compression processing on the absorbent layer of absorbent articles such as sanitary napkins (laminated body of the front sheet and the absorbent body) (see, for example, Japanese Patent Laid-Open No. 9-108262 Bulletin). In the sanitary napkin described in this gazette, the anti-leakage groove is formed by compressing the absorbent layer in the thickness direction to dent the absorbent body, and the thickness of the top sheet itself is kept substantially uniform. Therefore, in the initial stage of liquid absorption, the liquid enters into the fibrous structure of the absorber or the liquid is absorbed into the water-absorbing polymer in the absorber, whereby the effect of liquid diffusion is exerted.

However, in the sanitary napkin described in JP-A-9-108262, when a liquid is repeatedly absorbed or a large amount of liquid is absorbed in a short period of time, the fibrous structure of the absorbent body is filled with liquid, or the water-absorbent polymer Swelling occurs, and therefore, the space for liquid diffusion disappears, and the liquid diffusibility tends to decrease.

Utility model content

Therefore, it is an object of the present invention to provide an absorbent article in which leak-proof grooves are provided on an absorbent layer by compression processing, wherein even when a liquid is repeatedly absorbed and a large amount of liquid is absorbed in a short period of time, the absorbent layer The absorbed liquid also has excellent diffusivity.

The present invention achieves the above objects by providing an absorbent article which is formed by laminating a front sheet made of a bulky nonwoven fabric and an absorbent sheet with low compression deformation. The absorbent layer is provided with an anti-leakage groove extending in a continuous linear shape in plan view on the side of the skin-contacting surface of the absorbent layer, and the anti-leakage groove is formed by compressing the absorbent layer along the thickness direction so that the The front sheet and the absorbent sheet are integrated and formed by denting at least the front sheet, and on the front sheet, the high compression portion and the low compression portion are located between the leak-proof grooves. Alternately arranged in the extending direction, a density gradient is formed from the low-compression part toward the high-compression part.

According to the absorbent article of the present invention, since the leak-proof groove is provided on the absorbent layer by compression processing, even when the liquid is repeatedly absorbed and a large amount of liquid is absorbed in a short time, the liquid absorbed in the absorbent layer has excellent Diffusion.

Description of drawings

Fig. 1 is a plan view showing a sanitary napkin as one embodiment of the absorbent article of the present invention.

Fig. 2(a) and Fig. 2(b) are II-II sectional views shown in Fig. 1 .

Fig. 3(a) is a longitudinal sectional perspective view showing the top sheet of the sanitary napkin shown in Fig. 1 .

Fig. 3(b) is a B-B sectional view shown in Fig. 3(a).

Fig. 4 is a plan view showing another embodiment of a sanitary napkin.

Detailed ways

Next, a sanitary napkin according to a preferred embodiment will be described with reference to the accompanying drawings to describe the absorbent article of the present invention.

As shown in Fig. 1, Fig. 2(a) and Fig. 2(b), the sanitary napkin 1 of the present embodiment has a front sheet 2 made of a bulky nonwoven fabric and an absorbent sheet with low compression deformation. The absorbent layer A formed by laminating the absorbent layer A, and the back sheet 3 disposed on the non-skin contact surface side of the absorbent layer A.

The front sheet 2 and the back sheet 3 have the same shape when viewed from above, the front and rear edges in the longitudinal direction are semicircular, and the edges on both sides in the width direction are curved inward in the width direction, and the front sheet 2 and the back The sheet 3 is larger than the absorbent sheet 4 in length and width.

In addition, unless otherwise specified in this specification, the "longitudinal direction" and the "width direction" mean the "longitudinal direction of the absorbent article" and "the widthwise direction of the absorbent article", respectively. When referring to "upper surface" and "lower surface", they mean "skin-contacting surface (side of one side)" and "non-skin-contacting surface (side of one side)" respectively.

The top sheet 2 covers the entire upper surface of the absorbent sheet 4 , and the back sheet 3 covers the entire lower surface of the absorbent sheet 4 . The front sheet 2 and the back sheet 3 protrude from the longitudinal direction front and back edge parts and the width direction both side edge parts of the absorbent sheet 4 in planar view. On the upper surface of the front sheet 2, a pair of side leak preventing members 5 forming side leak preventing walls are provided from the width direction both side edges to the width direction both sides edges of the absorbent sheet 4.

The front sheet 2 and the back sheet 3 protruding from the front and rear edges in the longitudinal direction of the absorbent sheet 4 form end flaps (end flaps) F1, and the end flaps F1 are joined to the front and rear edges in the longitudinal direction, so that A semicircular end seal portion S1 is formed. The front sheet 2 and the back sheet 3 protruding from both side edges in the width direction of the absorbent sheet 4 form side flaps (side flaps) F2, and the side flaps F2 and the side leakage preventing members 5 are joined to each other within the width. The edge portions on both sides in the direction, thereby forming the side seal portion S2 bent toward the inside in the width direction.

The longitudinal direction front and rear edge portions of the side leakage preventing member 5 are joined to the top sheet 2 via the leakage preventing wall seal portion S3 extending in the longitudinal direction. A pocket opening inward in the width direction is formed in the longitudinal central portion of the side leakage preventing member 5 without the leakage preventing wall sealing portion S3 .

An adhesive portion (not shown) for fixing underwear is provided on the lower surface of the back sheet 3 .

The top sheet 2 is made of a bulky nonwoven fabric. As a bulky nonwoven fabric, for example, as shown in FIG. 3( a) and FIG. 3( b ), those made of the first fiber layer 21 on the upper surface side and the second fiber layer 22 on the lower surface side are listed. Embossed sheet. In this concavo-convex sheet, the first fiber layer 21 and the second fiber layer 22 are partially thermally fused to form a thermally fused bonded portion (junction) 23, and in the first fiber layer 21, A large number of convex portions 24 having compressive elasticity are formed in portions other than the portion 23 .

The concave-convex sheet can be obtained by the following method: the first fiber layer 21 and the second fiber layer 22 composed of fiber aggregates are locally thermally melted and bonded according to a prescribed pattern by heat embossing, and then the second fiber layer 22 heat shrinks along the horizontal direction.

Specifically, thermal fusion bonding using thermal embossing is performed, for example, by making an embossed surface (circumferential surface of an embossing roll, etc.) on which a large number of embossing pins are regularly arranged, and the first fiber layer 21 and the second fiber layer. In the laminated body of layers 22, one side of the first fiber layer 21 is pressure-bonded, thereby melting the constituent fibers of the first fiber layer 21 and/or the second fiber layer 22 at the portion heat-pressed by each needle. The thermal shrinkage of the second fiber layer 22 is carried out, for example, as follows: the second fiber layer 22 is made of heat-shrinkable fibers or the second fiber layer 22 contains heat-shrinkable fibers in advance, and the first fiber layer 21 and the second fiber The second fibrous layer 22 is heat-treated while the layers 22 are thermally fusion-bonded or after both are thermally fusion-bonded. A large number of convex portions 24 are generated by thermally shrinking the second fiber layer 22 in the horizontal direction, thereby deforming portions of the first fiber layer 21 other than the heat-melt bonded portion 23 into a convex shape.

A large number of thermal fusion bonding parts 23 are regularly formed in a scattered point shape and a zigzag shape, and the distance between the thermal fusion bonding parts 23 is substantially constant.

Each convex portion 24 is formed in a hemispherical shape, and the inside thereof is filled with fibers constituting the first fiber layer 21 . In addition, the interface between the first fiber layer 21 and the second fiber layer 22 in the portion where each convex portion 24 is formed is not bonded but is in a state of close contact.

The constituent fibers of the first fiber layer 21 are preferably fibers that do not substantially have heat shrinkability, or do not thermally shrink below the heat shrink temperature of the constituent fibers of the second fiber layer 22 described later.

The fibers constituting the second fiber layer 22 are preferably fibers made of a thermoplastic polymer material and having heat shrinkability. Furthermore, the constituent fibers preferably also exhibit elastomeric behavior after shrinkage. Examples of the aforementioned fibers include latent crimped fibers. It is preferable that the content rate of the latent crimping fiber in the 2nd fiber layer 22 is 40 to 100 weight%. The latently crimped fiber is a fiber that can be treated in the same way as conventional nonwoven fabric fibers before being heated, and exhibits a spiral crimp when heated at a predetermined temperature, thereby exhibiting shrinkage properties. By using latently crimpable fibers, it is possible to simultaneously exhibit both thermal shrinkage and elastomeric behavior.

The latently crimped fiber is composed of, for example, an eccentric core-sheath type or a side-by-side type composite fiber composed of two types of thermoplastic polymer materials having different shrinkage rates. Examples thereof include fibers described in JP-A-9-292325 and Japanese Patent No. 2759331. The second fiber layer 22 contains, for example, the latently crimped fibers as described above, and at the same time as or after thermal fusion bonding with the first fiber layer 21, the curl of the fibers is expressed by heating to generate shrink. In this way, a part of constituent fibers of the top sheet 2 may also be formed using latent crimped fibers.

In order to form the anti-leak groove 6 of sufficient depth (detailed later), to form the height difference and density gradient between the apexes of the low compression portion 61 and the high compression portion 62 in the anti-leak groove 6, the thickness of the front sheet 2 It preferably has an appropriate thickness, specifically, preferably 0.5 mm or more, and more preferably 0.5 to 2.0 mm.

Although the absorbent sheet 4 has absorbency, it is thin and has extremely low compression deformability against compression in the thickness direction (hardly deformed even when compressed). In addition, the absorbent sheet 4 is a sheet having rigidity such that if a large compressive force is applied, it will dent even a little bit, but the degree of dent will not be large, and it will be deformed by bending and perforated before then. .

Examples of such sheets include absorbent sheets in which water-absorbing polymer particles are dispersed and arranged in a sheet of paper (see, for example, JP-A-8-246395). Such an absorbent sheet can be obtained, for example, by dispersing water-absorbing polymer particles on a wet fiber web produced by a wet process, superimposing paper thereon, drying and integrating them.

In addition, as the absorbent sheet 4, an absorbent sheet obtained by compounding constituent fibers and a polymerizable water-absorbent polymer by polymerization (see, for example, JP-A-11-93073) can be mentioned. Such an absorbent sheet can be obtained, for example, by attaching a liquid substance containing a polymerizable water-absorbing polymer to non-shaped fibers and polymerizing them.

In addition, the absorbent sheet 4 can also be formed by sandwiching a water-absorbent polymer between two sheets of paper or nonwoven fabrics or between folded paper or nonwoven fabrics, and then pressing the whole to form Integrate.

As the water-absorbent polymer, various water-absorbent polymers suitable for the formation method of the absorbent sheet 4 can be used.

The content of the water-absorbent polymer in the absorbent sheet 4 below the leak-proof groove 6 (described in detail later) is preferably 25% or more, more preferably 30% or more. The content is based on mass. When the content of the water-absorbent polymer is high, it is preferable from the viewpoint that the compression deformation property of the entire absorbent sheet 4 decreases.

The back sheet 3 is not particularly limited, but a leak-proof film sheet is used in this embodiment. As the side leak-proof member 5, non-woven fabrics, film sheets, paper, etc. can be cited, and from the viewpoint of leak-proof properties, it is preferable to use liquid-impermeable or impermeable hydrophobic non-woven fabrics, leak-proof fabrics, etc. For non-volatile film sheets, etc., hydrophobic non-woven fabrics are used in this embodiment.

As shown in FIG. 1 , on the side of the skin-contacting surface of the absorbent layer A, there is provided an anti-leakage groove 6 extending in a continuous linear shape in plan view. The top view shape of the anti-leakage groove 6 in this embodiment is a ring shape, specifically a track shape (a ring shape formed by connecting a semicircular arc curve and a pair of parallel straight lines). The position of the leak-proof groove 6 in this embodiment is at the center in the longitudinal direction of the region between the pair of side leak-proof members 5 , 5 . The width of the anti-leakage groove 6 is preferably 0.5-5.0 mm.

As shown in FIG. 2( a ) and FIG. 2( b ), the front sheet 2 and the absorbent sheet 4 are joined by the leak-proof groove 6 . Specifically, the anti-leakage groove 6 is formed by compressing the absorbent layer A in the thickness direction to integrate the top sheet 2 and the absorbent sheet 4, and at least the top sheet 2 is dented. Moreover, on the front sheet 2 , the high compression portions 62 and the low compression portions 61 are arranged alternately in the extending direction of the leak-proof groove 6 , forming a density gradient from the low compression portions 61 to the high compression portions 62 .

The form of integration of the top sheet 2 and the absorbent sheet 4 varies depending on their materials, integration methods, etc., and includes, for example, fusion bonding, pressure bonding, and fiber interweaving.

The low compression portion 61 is a portion subjected to compression processing under low stress, and the high compression portion 62 is a portion subjected to compression processing under high stress. Therefore, the height of the apex of the low compression portion 61 is higher than that of the high compression portion 62 , and unevenness is formed on the bottom of the leak prevention groove 6 along the extending direction of the leakage prevention groove 6 . In addition, the fiber density of the low-compression part 61 is sparser (lower) than that of the high-compression part 62 , and a density gradient is formed from the low-compression part 61 toward the high-compression part 62 . The fiber density of the high compression portion 62 is 1.5 times or more, preferably 2.0 times or more, the fiber density of the low compression portion 61 .

When the absorbent layer A is compressed in the thickness direction, the top sheet 2 made of a bulky nonwoven fabric is likely to be dented and plastically deformed in this state. On the other hand, the absorbent sheet 4 with low compression deformability is not substantially dented, or the portion located below the high compression portion 62 is discontinuously (intermittently) dented in the extending direction of the leak-proof groove 6 to generate plasticity. out of shape.

Specifically, the anti-leakage groove 6 has a form in which only the front sheet 2 is recessed as shown in FIG. 2( a ), and both the front sheet 2 and the absorbent sheet 4 as shown in FIG. Formed by depressions.

In the anti-leakage groove 6 formed only by the depression of the front sheet 2 as shown in FIG. . In addition, the top sheet 2 is less likely to be thinned during compression processing.

In the anti-leakage groove 6 that both the front sheet 2 and the absorbent sheet 4 are sunken as shown in Figure 2 (b), the front sheet 2 that forms the highly compressed portion 62 of the anti-leakage groove 6 is It is compressed under high stress, so thinning may occur. In this case, the liquid flowing into the high compression part 62 is absorbed by the absorbent sheet 4 via the low compression part 61 .

In the entire absorbent article, the anti-leakage groove 6 may be formed only in the form shown in FIG. 2( a ) or only in the form shown in FIG. 2( b ), or may be formed by mixing the two forms.

The depth H1 of the anti-leakage groove 6 (the height difference between the vertex of the surface sheet 2 and the vertex of the highly compressed part 62) is preferably 0.5-5.0 mm, more preferably 1.0-4.0 mm.

The height difference H2 between the top of the low compression portion 61 and the top of the high compression portion 62 is preferably 0.25 to 2.5 mm, more preferably 0.5 to 2.0 mm.

The method of forming the above-mentioned "the surface sheet 2 must be depressed, while the absorbent sheet 4 is substantially not depressed or the absorbent sheet 4 is depressed discontinuously in the direction in which the leakage-proof groove 6 extends" It is not particularly limited, and examples include the following methods.

A squeeze roll (not shown) provided with a squeeze portion having a concavo-convex shape corresponding to the shapes of the low compression portion 61 and the high compression portion 62 of the leak prevention groove 6 is used. The front side of the absorbent layer A on which the leak-proof groove 6 is not formed is squeezed with the squeeze roll, and heat-sealing is performed. Here, in order to form the leak-preventing groove 6 in which the high compression portions 62 and the low compression portions 61 are alternately arranged on the top sheet 2, processing conditions must be appropriately set. Particularly important conditions are the shape (height, width, concave-convex shape, etc.), extrusion pressure, heating temperature (heat sealing temperature), and extrusion time of the extrusion portion.

In the sanitary napkin 1 of this embodiment, the absorbent layer A is formed by laminating the top sheet 2 made of a bulky nonwoven fabric and the absorbent sheet 4 with low compression deformation. Therefore, when the absorbent layer A is compressed in the thickness direction to integrate the surface sheet 2 and the absorbent sheet 4, the surface sheet 2 is likely to be dented and plastically deformed to form all of the continuous linear leak-proof grooves 6. (form shown in FIG. 2( a )) or a part (form shown in FIG. 2( b )). On the other hand, since the absorbent sheet 4 has low compression deformability, when the absorbent layer A is compressed, the absorbent sheet 4 does not substantially dent even if the surface sheet 2 tends to dent (Fig. 2(a) shown), or discontinuously (intermittently) recessed in the extending direction of the leak-proof groove 6 to cause plastic deformation (the form shown in FIG. 2( b )).

As a result, on the front sheet 2, "the front sheet 2 must be sunken, and the absorbent sheet 4 is not sunk substantially or the absorbent sheet 4 is sunken discontinuously in the extending direction of the leak-proof groove 6." Leak-proof groove 6". From another point of view, "the leak-proof groove 6 in which the high-compression parts 62 and the low-compression parts 61 are alternately arranged and a density gradient is formed from the low-compression parts 61 toward the high-compression parts 62" is formed.

According to the sanitary napkin 1 of the present embodiment of the structure as described above, on the front sheet 2, the high compression portions 62 and the low compression portions 61 are alternately arranged in the extending direction of the leak-proof groove 6, from the low compression portions 61 toward the The high compression portion 62 forms a density gradient. Therefore, the liquid flowing into the leak-proof groove 6 moves from the low-compression part 61 toward the high-compression part 62 by the capillary force generated by the density gradient between the low-compression part 61 and the high-compression part 62, thereby being highly compressed. Efficiently introduced into the absorbent sheet 4 .

Therefore, it is possible to reduce the moist feeling on the wearer's skin and maintain a comfortable feeling of use for a long time. Therefore, even in the case of repeated absorption of liquid and absorption of a large amount of liquid in a short time, the liquid absorbed in the absorbent layer has excellent diffusibility.

In addition, since the flow of the liquid is directional along the extending direction of the anti-leakage groove 6 , the liquid is less likely to leak outside the annular anti-leakage groove 6 .

As the front sheet 2, when using the concave-convex sheet shown in Figure 3 (a) and Figure 3 (b), the contact layer with the absorbent sheet 4, that is, the second fiber layer 22 of the lower layer is not easy to contact with the absorbent sheet. 4 fusion bonding. Therefore, since the diffusion path exists in the lower layer (second fiber layer 22) of the surface sheet 2, the diffusibility of the liquid in the surface direction (direction perpendicular to the thickness direction) is high.

The absorbent article of this invention is not limited to the said embodiment, Unless it deviates from the summary of this invention, it can change suitably.

For example, as shown in FIG. 4 , it is also possible to arrange a plurality of leak-proof grooves 6 along the width direction of the absorbent article 1 along the length of the absorbent article (sanitary napkin) 1 on the inner side of the annular leak-proof groove 6 . Another anti-leakage groove 6' extending in the direction. In the embodiment shown in Fig. 4, two anti-leakage grooves 6' extending linearly in the longitudinal direction of the sanitary napkin 1 are provided. According to the form of the leak-proof groove 6' extending in the longitudinal direction provided on the inside of the annular leak-proof groove 6 as described above, the inside of the ring-shaped leak-proof groove 6, the diffusion of the liquid along the longitudinal direction The performance is further improved, which is preferable from this point of view.

The top view shape of the leak-proof groove is not limited to a ring shape, and may be a linear or curved shape extending in the longitudinal direction of the absorbent article, or a linear or curved shape extending in the width direction of the absorbent article.

The absorbent article of the present invention is not only applicable to sanitary napkins, but also applicable to underwear linings, sanitary pads, incontinence pads, and the like.

According to the absorbent article of the present invention, since the leak-proof groove is provided on the absorbent layer by compression processing, even when the liquid is repeatedly absorbed and a large amount of liquid is absorbed in a short time, the liquid absorbed in the absorbent layer has excellent Diffusion.

Claims (5)

1. An absorbent article comprising an absorbent layer formed by laminating a top sheet made of a bulky nonwoven fabric and an absorbent sheet with low compression set, wherein on the skin-contacting surface of the absorbent layer One side is provided with an anti-leakage groove extending in a continuous linear shape when viewed from above; the anti-leakage groove is formed by compressing the absorbent layer along the thickness direction so that the front sheet and the absorbent sheet are integrated At the same time, it is formed by denting at least the front sheet; on the front sheet, high compression parts and low compression parts are alternately arranged in the extending direction of the leak-proof groove, from the low compression part toward A density gradient is formed along the high compression portion. 2. The absorbent article according to claim 1, wherein the content of the water-absorbing polymer in the absorbent sheet below the leak-proof groove is 25% or more. 3. The absorbent article according to claim 1 or 2, wherein the thickness of the top sheet is 0.5 mm or more. 4. The absorbent article according to claim 1 or 2, wherein the leak-proof groove has an annular planar shape. 5. The absorbent article according to claim 4, characterized in that, inside the annular said leak-proof groove, a plurality of other said anti-leakage grooves are provided at a distance from each other along the width direction of the absorbent article. A gutter, the other said leak-proof groove extends in the lengthwise direction of the absorbent article.

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