JP2024088554A - Absorbent article - Google Patents

Abstract

To provide an absorbent article in which wrinkles are unlikely to occur to a skin side surface.SOLUTION: An absorbent article (1) has a longitudinal direction, a width direction and a thickness direction in an unfolded state, and has in a central part in the width direction: a skin side layer (2) provided nearest on the skin side; a non-skin side layer (3) provided on the non-skin side of the skin side layer (2); and a liquid-impermeable outer layer (4) provided on the non-skin side of the non-skin side layer (3). The skin side layer (2) and the non-skin side layer (3) have a plurality of fibers including latently crimpable fibers, respectively. In the skin side layer (2) and the non-skin side layer (3), the plurality of fibers are not fused to one another.SELECTED DRAWING: Figure 3

Description

The present invention relates to an absorbent article.

Conventionally, absorbent articles such as sanitary napkins, disposable diapers, and absorbent pads are known. For example, Patent Document 1 discloses a sanitary napkin having a top sheet arranged on the skin contact side, a back sheet arranged on the non-skin contact side, and an absorbent body arranged between the top sheet and the back sheet. The absorbent body in Patent Document 1 is made of pulp fibers, etc.

JP 2013-176412 A

Absorbent articles such as sanitary napkins in Patent Document 1 and the like develop wrinkles and creases on the skin side of the absorbent article due to the shape of the wearer's body when worn and the wearer's movements, etc. These wrinkles and creases can mar the aesthetic appearance of the absorbent article, cause discomfort to the wearer's skin due to the stiffness of the wrinkled areas, and there is a risk that excrement will leak out of the absorbent article by running down the wrinkles.

The present invention was made in consideration of the above problems, and its purpose is to provide an absorbent article that is less likely to wrinkle on the skin side.

The main invention for achieving the above-mentioned object is an absorbent article which, in an unfolded state, has a longitudinal direction, a width direction and a thickness direction, and in the central part in the width direction, has a skin side layer provided closest to the skin, a non-skin side layer provided further from the skin side layer, and a liquid-impermeable outer layer provided further from the non-skin side layer, wherein the skin side layer and the non-skin side layer each have a plurality of fibers including latent crimp fibers, and wherein the plurality of fibers are not fused to each other in the skin side layer and the non-skin side layer.
Other features of the present invention will become apparent from the following detailed description of the present invention and the accompanying drawings.

The present invention makes it possible to prevent wrinkles from forming on the skin side of an absorbent article.

FIG. 2 is a plan view of the sanitary napkin 1 as seen from the skin side. 2 is a schematic cross-sectional view of the napkin 1 taken along the line AA. 1A and 1B are diagrams illustrating the configuration of a napkin 1. 1 is a diagram illustrating an absorbent layer 10 of a napkin 1. FIG. Fig. 5A is a diagram showing a schematic cross section of the skin side layer 2. Fig. 5B is a diagram showing a schematic cross section of the non-skin side layer 3. FIG. 5 is an enlarged view of a portion X in FIG. 4 . 7 is a schematic cross-sectional view taken along the line BB in FIG. 6. FIG. 2 is a diagram illustrating the napkin 1 30 minutes after horse blood is dripped onto it. FIG. 4 is a diagram illustrating a measurement region Y. FIG. 13 is a diagram for explaining an overview of a method for evaluating the narrowness of a gap Z. FIG. 1 is a diagram showing the results of a narrowness evaluation test and a void ratio evaluation test. Fig. 12A is a diagram showing the measurement results of the bending property of the absorbent layer 10 by the KES method. Fig. 12B is a diagram showing the measurement results of the compression property of the absorbent layer 10 by the KES method. 1 is a diagram showing the measurement results of an elongation test of the absorbent layer 10. FIG. 11A and 11B are diagrams illustrating a modified example of a napkin 100 according to the present embodiment.

At least the following points will become apparent from the description of this specification and the accompanying drawings.
(Aspect 1)
The absorbent article has, in an unfolded state, a longitudinal direction, a width direction, and a thickness direction, and in a central portion in the width direction, a skin-side layer provided closest to the skin, a non-skin-side layer provided further from the skin-side layer, and a liquid-impermeable outer layer provided further from the non-skin-side layer, wherein the skin-side layer and the non-skin-side layer each have a plurality of fibers including latent crimped fibers, and the plurality of fibers are not fused to each other in the skin-side layer and the non-skin-side layer.

According to the absorbent article of aspect 1, since the fibers in the skin side layer and the non-skin side layer are not fused to each other, it is possible to reduce the decrease in the absorbency of the skin side layer and the non-skin side layer, and to reduce the risk of the skin side layer and the non-skin side layer becoming hard. Furthermore, since the skin side layer and the non-skin side layer have latent crimped fibers, it is possible to reduce the risk of the skin side layer and the non-skin side layer becoming excessively hard, and to make it difficult for wrinkles to form on the skin side of the absorbent article even when the absorbent article is folded or compressed in a packaged state, or when force is applied to the absorbent article when worn, etc.

(Aspect 2)
Aspect 2 is an absorbent article according to aspect 1, wherein the non-skin side layer has a linear high density portion in which the density of the fibers is higher than that of the surrounding area.

According to the absorbent article of aspect 2, since it is possible to provide linear portions with narrow gaps between the fibers, it becomes easier to promote the diffusion of absorbed excrement in the non-skin side layer by capillary action. In addition, since the fiber density around the high density portion is lower than that of the high density portion, the area around the high density portion is softer than the high density portion, so that the area around the high density portion in the non-skin side layer can easily cushion the force applied to the absorbent article, and it becomes easier to prevent the force applied to the absorbent article from causing wrinkles on the skin side of the absorbent article.

(Aspect 3)
The absorbent article according to aspect 1 or 2, wherein the non-skin side layer has a recess that is recessed in the thickness direction on the skin side surface.

According to the absorbent article of aspect 3, the recess is a portion separated from the skin side layer, so that the risk of excrement absorbed by the non-skin side layer returning to the skin side layer can be reduced. In addition, by having a recess on the skin side of the non-skin side layer, the non-skin side layer is more likely to deform than if the skin side of the non-skin side layer were flat, so that the non-skin side layer can more easily cushion the force applied to the absorbent article, and wrinkles are less likely to form on the skin side of the skin side layer of the absorbent article.

(Aspect 4)
Aspect 4. The absorbent article according to any one of Aspects 1 to 3, wherein no adhesive is provided between the skin side layer and the non-skin side layer in the central portion in the width direction.

According to the absorbent article of aspect 4, it is possible to reduce the risk that the adhesive will hinder the absorption of excrement. In addition, by not providing an adhesive between the skin side layer and the non-skin side layer and not fixing the fibers of the skin side layer and the fibers of the non-skin side layer with an adhesive, it is possible to reduce the risk that the deformation of the fibers of the skin side layer and the non-skin side layer will be restricted and to prevent the parts fixed with the adhesive from becoming hard, thereby reducing the risk that the force applied to the absorbent article will be concentrated in the parts where the skin side layer and the non-skin side layer are fixed with the adhesive.

(Aspect 5)
Aspect 5 is the absorbent article according to any one of aspects 1 to 4, wherein the skin side layer has a thickness greater than a thickness of the non-skin side layer.

According to the absorbent article of aspect 5, the non-skin side layer can be placed farther away from the wearer's skin than when the thickness of the skin side layer is thinner than the thickness of the non-skin side layer, thereby improving the feel of the absorbent article against the wearer's skin while reducing the risk of excrement once absorbed by the non-skin side layer returning to the skin side of the skin side layer. In addition, the skin side layer is less likely to be folded than when the thickness of the skin side layer is thinner than the thickness of the non-skin side layer, making it easier to prevent wrinkles from forming on the skin side of the absorbent article.

(Aspect 6)
The absorbent article of any one of aspects 1 to 5, wherein the skin side layer has gaps formed by the plurality of fibers, and when the skin side layer is divided into thirds in the thickness direction, with the region closest to the skin being the skin side region, the region closest to the skin being the non-skin side region, and the region between the skin side region and the non-skin side region being the intermediate region, the average narrowness of the non-skin side regions in a narrowness evaluation test for quantitatively evaluating the narrowness of the gaps is smaller than the average narrowness of the skin side regions in the narrowness evaluation test.

According to the absorbent article of aspect 6, the capillary phenomenon makes it easier to draw excrement from the skin side region to the non-skin side region, and the excrement absorbed from the skin side of the skin side layer is more easily diffused to the non-skin side, which makes it easier to promote the diffusion of excrement from the skin side layer to the non-skin side layer, and reduces the risk of excrement remaining on the surface of the skin side layer. In addition, the narrower the gaps caused by the fibers, the denser the fiber structure becomes, making it more difficult for the fibers to move, and the easier it is for the fibers to recover their shape when force is applied to them. Therefore, by making the average narrowness of the skin side region larger than the average narrowness of the non-skin side region, the fiber structure of the skin side region is less dense and the fibers are more easily moved, which makes the fibers more easily recover when force is applied to them, and therefore reduces the risk of wrinkles and creases being formed in the skin side region compared to the non-skin side region, making it easier to reduce wrinkles and creases that occur on the skin side of the absorbent article.

(Aspect 7)
The skin side layer has voids formed by the plurality of fibers, and when the skin side layer is divided into thirds in the thickness direction, with the region closest to the skin side being the skin side region, the region closest to the skin side being the non-skin side region, and the region between the skin side region and the non-skin side region being an intermediate region, the void ratio of the non-skin side region in a void ratio evaluation test for quantitatively evaluating the ratio of the voids in a specified region is smaller than the void ratio of the skin side region in the void ratio evaluation test.This is an absorbent article described in any of aspects 1 to 6.

According to the absorbent article of aspect 7, the capillary phenomenon makes it easier to draw excrement into the non-skin side region than into the skin side region, and excrement absorbed from the skin side of the skin side layer is more easily diffused into the non-skin side layer, which makes it easier to promote the diffusion of excrement from the skin side layer to the non-skin side layer, thereby reducing the risk of excrement remaining on the surface of the skin side layer. In addition, the smaller the ratio of voids in the fibers, the denser the fiber structure becomes, making it more difficult for the fibers to move, and the lower the recovery of the fiber shape when force is applied to the fibers. Therefore, by making the void ratio in the skin side region larger than the void ratio in the non-skin side region, the fiber structure in the skin side region is less dense than when the void ratio in the skin side region is smaller than the void ratio in the non-skin side region, making the fiber structure more difficult to become dense and easier to move, which improves the recovery when force is applied to the fibers, thereby reducing the risk of wrinkles and creases being formed in the skin side region than in the non-skin side region, which makes it easier to reduce wrinkles and creases that occur on the skin side of the absorbent article.

(Aspect 8)
Aspect 8 is the absorbent article according to any one of aspects 1 to 7, wherein the hydrophilicity of the skin side layer is lower than the hydrophilicity of the non-skin side layer.

The absorbent article of aspect 8 is more likely to promote the diffusion of excrement absorbed by the skin-side layer to the non-skin-side layer, reducing the risk of excrement remaining on the surface of the skin-side layer and reducing the risk of excrement leaking from the absorbent article.

(Aspect 9)
The skin side layer has voids formed by the plurality of fibers, and when the skin side layer is divided into three equal parts in the thickness direction, with the region closest to the skin side being the upper region, the region closest to the skin side being the lower region, and the region between the skin side region and the non-skin side region being the intermediate region, at least a portion of the fibers in the non-skin side region are more hydrophilic than the fibers in the skin side region, and a portion of the fibers in the non-skin side region are exposed on the skin side surface of the skin side region, this is an absorbent article described in any of aspects 1 to 8.

According to the absorbent article of aspect 9, the exposed fibers of the non-skin side region tend to draw the excrement absorbed from the skin side toward the non-skin side region, facilitating the diffusion of the excrement within the non-skin side region and facilitating the diffusion of the excrement from the skin side layer to the non-skin side layer, thereby reducing the risk of excrement remaining on the surface of the skin side region.

(Aspect 10)
Aspect 10 is the absorbent article according to any one of aspects 1 to 9, wherein a maximum fiber thickness of the skin side layer is greater than a maximum fiber thickness of the non-skin side layer.

According to the absorbent article of aspect 10, the thicker the fibers are, the larger the gaps formed by the fibers, and therefore the gaps formed by the fibers of the non-skin side layer are easier to narrow than the gaps formed by the fibers of the skin side layer, and therefore the capillary phenomenon makes it easier to draw excrement from the skin side layer to the non-skin side layer, and the diffusion in the non-skin side layer is easier to improve. In addition, the thinner the fibers are, the narrower the gaps formed by the fibers are, and the denser the fiber structure is, the harder the fibers are to move, and the easier it is to reduce the recovery of the fiber shape when force is applied to the fibers. Therefore, by making the fiber thickness of the skin side region thicker than that of the non-skin side region, the fiber structure of the skin side region is less dense than when the fiber thickness of the skin side region is thinner than that of the non-skin side region, and the fiber structure is easier to move, and the fiber has better recovery when force is applied, and therefore the risk of wrinkles and creases being formed in the skin side region is reduced compared to when the fiber thickness of the skin side region is thinner than that of the non-skin side region, and therefore it is easier to reduce wrinkles and creases that occur on the skin side of the absorbent article.

(Aspect 11)
Aspect 11 is an absorbent article according to any one of aspects 1 to 10, wherein the latently crimped fibers of the skin side layer and the non-skin side layer are fibers made of a resin having a single composition.

According to the absorbent article of aspect 11, the skin side layer and non-skin side layer using latent crimped fibers made of a single-component resin tend to have uniform physical properties, making it possible to reduce the occurrence of wrinkles on the skin side of the absorbent article. In addition, by using a single-component resin for the skin side layer and non-skin side layer, the number of parts required for manufacturing the absorbent article can be reduced, reducing the manufacturing cost of the absorbent article and improving the workability of manufacturing and recycling.

(Aspect 12)
12. The absorbent article according to any one of Aspects 1 to 11, wherein the latently crimped fibers of the skin side layer and the non-skin side layer are each made of polyethylene terephthalate.

According to the absorbent article of aspect 12, the skin side layer and non-skin side layer using latent crimped fibers made of polyethylene terephthalate tend to have uniform physical properties, making it possible to make the skin side of the absorbent article less prone to wrinkles. In addition, by using polyethylene terephthalate for the skin side layer and non-skin side layer, the number of parts required for manufacturing the absorbent article can be reduced, reducing the manufacturing cost of the absorbent article and improving the workability of manufacturing and recycling.

(Aspect 13)
The absorbent article is described in any one of aspects 1 to 12, wherein, when the skin side layer and the non-skin side layer are stacked, the bending rigidity B of the central portion in the longitudinal direction and the central portion in the width direction of the skin side layer and the non-skin side layer, as measured by the KES method, is 1.2 gf· ^cm2 /cm or less.

According to the absorbent article of aspect 13, the absorbent article can be made more flexible than when the bending rigidity B of the skin side layer and the non-skin side layer is greater than 1.2 gf· ^cm2 /cm, thereby reducing the risk of wrinkles forming in the absorbent article.

(Aspect 14)
The absorbent article is described in any one of aspects 1 to 13, wherein, when the skin side layer and the non-skin side layer are stacked, the bending hysteresis 2HB of the skin side layer and the non-skin side layer in the longitudinal center and the width direction center is 0.93 gf· ^cm2 /cm or less, as measured by the KES method.

According to the absorbent article of aspect 14, the skin side layer and non-skin side layer that have been deformed when worn can more easily return to their original shape than when the bending hysteresis 2HB of the skin side layer and non-skin side layer is greater than 0.93 gf・^cm2 /cm, thereby reducing the risk of wrinkles forming in the absorbent article.

(Aspect 15)
The absorbent article is described in any one of aspects 1 to 14, wherein, when the skin side layer and the non-skin side layer are stacked together, the linearity LC of the compression characteristics in the central portion in the longitudinal direction and the central portion in the width direction of the skin side layer and the non-skin side layer, as determined by the KES method, is 0.6 or more.

According to the absorbent article of aspect 15, the skin side layer and the non-skin side layer can be made more compressively rigid than when the linearity LC of the compression characteristics of the skin side layer and the non-skin side layer is less than 0.6, so that deformation of the skin side layer and the non-skin side layer can be reduced, thereby reducing the risk of wrinkles forming in the absorbent article.

(Aspect 16)
The absorbent article is described in any one of aspects 1 to 15, wherein, when the skin side layer and the non-skin side layer are stacked together, the compression resilience RC of the central portion in the longitudinal direction and the central portion in the width direction of the skin side layer and the non-skin side layer, as measured by the KES method, is 38.0% or more.

According to the absorbent article of aspect 16, the shape of the skin-side layer and the non-skin-side layer when worn can be restored more easily than when the compression resilience of the skin-side layer and the non-skin-side layer is less than 38%, so the risk of wrinkles forming in the absorbent article can be reduced.

(Aspect 17)
17. The absorbent article according to any one of aspects 1 to 16, wherein, when the skin side layer and the non-skin side layer are overlapped with each other, a compression work WC of the central portion in the longitudinal direction and the central portion in the width direction of the skin side layer and the non-skin side layer, as measured by the KES method, is 1.3 gf cm/ ^cm2 or more.

According to the absorbent article of aspect 17, the skin side layer and the non-skin side layer are more easily compressed and have good compression recovery properties than when the compression work load in the longitudinal center and width center of the skin side layer and the non-skin side layer is less than 1.3 gf·cm/ ^cm2 , so that the skin side layer and the non-skin side layer can be more easily restored to their original shapes, thereby reducing the risk of wrinkles forming in the absorbent article.

(Aspect 18)
18. An absorbent article according to any one of aspects 1 to 17, wherein, when viewed in the thickness direction, the predetermined region is the center of the longitudinal direction and the center of the width direction of the absorbent article, the weight of the predetermined region before it absorbs distilled water is the pre-absorption weight, the weight of the predetermined region after it is immersed in distilled water for 60 seconds and then pulled out of the distilled water and hung for 90 seconds is the post-absorption weight, and the absorption weight of the distilled water is determined by subtracting the pre-absorption weight from the post-absorption weight, and the value obtained by dividing the absorption weight by the pre-absorption weight is 5 or more.

According to the absorbent article of aspect 18, the risk of wrinkles forming in the absorbent article can be reduced while still maintaining the liquid absorption function, compared to when the value obtained by dividing the absorbed weight by the weight before absorption is less than 5.

(Aspect 19)
19. The absorbent article of any one of aspects 1 to 18, wherein in an elongation test measuring the magnitude of force required to elongate the longitudinal length of the skin side layer and the non-skin side layer while the skin side layer and the non-skin side layer are stacked together to a length that is 1.3 times the longitudinal length of the skin side layer and the non-skin side layer, the value obtained by dividing the magnitude of force measured in a 10th measurement of the elongation test of the skin side layer and the non-skin side layer by the magnitude of force measured in a first measurement of the elongation test of the skin side layer and the non-skin side layer is 50% or more.

According to the absorbent article of aspect 19, when the value obtained by dividing the force magnitude value from the 10th measurement in the elongation test by the force magnitude value from the first measurement is 50% or more, the absorbent article can be made to be more likely to follow the shape and movement of the wearer's body while reducing damage to the skin-side layer and non-skin-side layer even when worn, compared to when the value obtained by dividing the force magnitude value from the 10th measurement in the elongation test by the force magnitude value from the first measurement is less than 50%.

(Aspect 20)
20. The absorbent article according to any one of aspects 1 to 19, wherein an airflow resistance value in a state in which the skin side layer and the non-skin side layer are stacked together is 0.32 kpa·s/m or less.

According to the absorbent article of aspect 20, the breathability of the absorbent article can be improved compared to when the airflow resistance value in the state where the skin side layer and the non-skin side layer are overlapped is greater than 0.32 kpa·s/m, thereby reducing discomfort for the wearer of the absorbent article.

====Embodiment===
An embodiment of the absorbent article according to the present invention will be described taking a sanitary napkin 1 (hereinafter also referred to as "napkin 1") as an example of the absorbent article according to the present invention. However, the absorbent article according to the present invention may be a pants-type disposable diaper or a tape-type disposable diaper for adults or infants, sanitary shorts, sanitary napkin, light incontinence pad, absorbent pad, disposable diaper or absorbent sheet for animals, drip sheet, etc. In the case of a drip sheet or the like, the "wearing state" in the following embodiment becomes a "use state" and the wearer becomes a "user, etc." Hereinafter, the wearing state is also referred to as a "use state" and the wearer is also referred to as a "user, etc."

<<<<Configuration of sanitary napkin 1>>>
FIG. 1 is a plan view of a sanitary napkin 1 (hereinafter also referred to as "napkin") as seen from the skin side. FIG. 2 is a schematic cross-sectional view of the napkin 1 taken along the line A-A. FIG. 3 is a diagram for explaining the configuration of the napkin 1. The napkin 1 has a longitudinal direction, a width direction, and a thickness direction which are perpendicular to one another. In the thickness direction, the side that contacts the wearer's skin is the skin side, and the opposite side is the non-skin side. The skin side in the thickness direction is the side that receives excrement (liquid) when worn, and is also referred to as the "absorbent side". The non-skin side in the thickness direction is the side opposite to the absorbent side, and is also referred to as the "non-absorbent side". The center line C-C shown in FIG. 1 etc. indicates the center (central position) of the napkin 1 in the width direction.

The napkin 1 has a skin-side layer 2, a non-skin-side layer 3, a back sheet (outer layer) 4, and a side sheet 5. As shown in FIG. 3 etc., the napkin 1 is layered in the thickness direction in the following order from the skin side: side sheet 5, skin-side layer 2, non-skin-side layer 3, and back sheet 4. Each member layered in the thickness direction is fixed together with an adhesive such as a hot melt adhesive.

The skin-side layer 2 is the skin-side sheet located closest to the skin in the center of the width of the napkin 1, and is an absorbent member that abuts against the excretory opening when worn and receives excrement discharged from the excretory opening. The skin-side layer 2 is substantially rectangular in shape and is long in the longitudinal direction, with the longitudinal length L2 being longer than the width length W2. By providing the skin-side layer 2 at the crotch position of the wearer when the napkin 1 is worn, when the napkin 1 absorbs excrement, the skin-side layer 2 can absorb the excrement and diffuse the absorbed excrement toward the non-skin-side layer 3. This can reduce discomfort to the wearer caused by excrement leaking from the napkin 1 or excrement remaining locally on the surface of the skin-side layer 2, etc.

The non-skin-side layer 3 is a non-skin-side sheet provided between the skin-side layer 2 and the back sheet 4 in the thickness direction, and the non-skin-side layer 3 is slightly smaller than the skin-side layer 2 in a plan view. The non-skin-side layer 3 is substantially rectangular in shape and has a longitudinal length L3 longer than a widthwise length W3. The non-skin-side layer 3 is an absorbent member that absorbs the excrement absorbed by the skin-side layer 2 and retains the excrement. By providing the non-skin-side layer 3 at the crotch position of the wearer when the napkin 1 is worn, when the napkin 1 absorbs excrement, the non-skin-side layer 3 can absorb the excrement and disperse the excrement within the non-skin-side layer 3. This can reduce discomfort to the wearer caused by excrement leaking from the napkin 1 or excrement staying locally on the surface of the skin-side layer 2, etc.

The skin-side layer 2 and the non-skin-side layer 3 are nonwoven fabrics (nonwoven fabric sheets) made of latent crimped fibers 2f and latent crimped fibers 3f (see FIG. 5), respectively. In this embodiment, the skin-side layer 2 and the non-skin-side layer 3 are nonwoven fabrics made of only latent crimped fibers (latent crimped fibers are 100%). However, the layers (nonwoven fabrics) constituting the skin-side layer 2 and the non-skin-side layer 3 may use, in addition to latent crimped fibers, fibers made of polyolefins such as polyethylene (PE) and polypropylene (PP), polyesters (PET and PBT), polyamides, etc., and composite fibers of these, as well as hydrophilic fibers such as rayon, pulp, and cotton. Hereinafter, the latent crimped fibers 2f and the latent crimped fibers 3f are also simply referred to as "fibers 2f" and "fibers 3f".

"Nonwoven fabric" refers to a fiber sheet, web, or batt in which the fibers are oriented in one direction or randomly and are bonded by entanglement and/or fusion and/or adhesion (JIS L0222:2001 Nonwoven fabrics terminology 101). In other words, nonwoven fabrics are fabrics in which the fibers are integrated without being woven, and are sheets with a breaking strength of 5 [N]/25 mm or more. The breaking strength can be measured by a well-known method, for example, by the following method. A tensile tester (Shimadzu Corporation: Autograph, AGS-1kNG) equipped with a load cell with a maximum load capacity of 50 N is used. When measuring the separation strength of a nonwoven fabric sheet, one chuck grips the tip of one side of the nonwoven fabric sheet in the longitudinal or transverse direction, and the other chuck grips the other side of the nonwoven fabric sheet. Using a tensile tester, the two chucks are pulled at a constant speed (e.g., 100 mm/min) so that the distance between them increases, while the load applied to the two chucks is measured. The load at which the nonwoven fabric sheet breaks is the breaking strength.

Examples of nonwoven fabrics include nonwoven fabrics obtained by the meltblown method (meltblown nonwoven fabric), nonwoven fabrics obtained by the electrospinning method (electrospinning nonwoven fabric), nonwoven fabrics obtained by the spunbond method (spunbond nonwoven fabric), nonwoven fabrics produced by the air-through method (air-through nonwoven fabric), nonwoven fabrics produced by the spunlace method (spunlace nonwoven fabric), nonwoven fabrics produced by the needlepunch method (needlepunch nonwoven fabric), or laminates of two or more of these nonwoven fabrics, or laminates of these nonwoven fabrics with other nonwoven fabrics or other materials. The skin-side layer 2 and the non-skin-side layer 3 of this embodiment are spunlace nonwoven fabrics in which no adhesive is used and the fibers are entangled by a water flow.

The nonwoven fabric sheet of the skin side layer 2 of the napkin 1 of this embodiment is formed by the spunlace method through the following steps.
(a) First, hydrophilic fibers 2fb (fibers 2f forming at least a part of the non-skin side region Rd described below) are processed by a carding machine or the like to form a non-skin side fiber web having a form such as a carded web.
(b) Next, the hydrophobic fibers 2fa are processed using a carding machine or the like to produce a skin-side fiber web having the form of a carded web or the like, which is then fed onto the non-skin-side fiber web while the non-skin-side fiber web is being transported, and laminated to obtain a laminated web.
(c) A high-pressure water jet treatment such as a water jet is applied from the skin side to the non-skin side in the thickness direction of the laminated web to entangle the fibers between each fiber layer and the fibers between each web, thereby obtaining a laminate.
(d) Finally, the laminate is placed in a dryer and heated to a temperature at which the latent crimpable fibers can shrink, thereby obtaining an integrated nonwoven fabric sheet (skin side layer 2). This nonwoven fabric sheet has voids formed by the plurality of fibers 2f.

The nonwoven fabric sheet of the non-skin side layer 3 of the napkin 1 of this embodiment is formed in the same manner as the nonwoven fabric sheet of the skin side layer 2. However, the nonwoven fabric sheet of the non-skin side layer 3 differs from the skin side layer 2 in that it does not use hydrophobic fibers, but is made by laminating only a web of hydrophilic fibers 3f.

Latent crimp fibers 2f and 3f are fibers that shrink when heated to develop a helical shape. Examples of latent crimp fibers include side-by-side composite fibers in which high and low shrinkage components are arranged in parallel, and eccentric core-sheath composite fibers in which the high shrinkage component is the core and the low shrinkage component is the sheath, with the centers of gravity of both components not overlapping at a single point. When the crimp of the latent crimp fiber is developed, the latent crimp fiber shrinks, for example, into a coil shape.

As the multiple resins with different thermal shrinkage rates or thermal expansion rates that form the latent crimped fibers 2f and 3f, any combination of resins with different thermal shrinkage rates or thermal expansion rates can be used without any particular limitations, and may be a combination of the same or a single resin, or a combination of different resins. Specific examples of combinations of resins with different thermal shrinkage rates or thermal expansion rates that form the latent crimped fibers include combinations of polyester resins and combinations of polyamide resins.

The nonwoven fabric of the skin side layer 2 and the non-skin side layer 3 of this embodiment is a combination of polyester resins (single component resins), specifically, a latent shrink fiber of a combination of polyethylene terephthalate (PET) and modified PET is used. The modified PET is a PET modified by copolymerizing ethylene glycol and terephthalic acid, which are the components of PET, with a diol component other than ethylene glycol or a dicarboxylic acid component other than terephthalic acid as a minor component. Specific examples of diol components other than ethylene glycol include, for example, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, cyclohexanedimethanol, diethylene glycol, triethylene glycol, polyethylene glycol, polytetramethylene glycol, etc. Specific examples of dicarboxylic acid components other than terephthalic acid include, for example, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, cyclohexanedicarboxylic acid, adipic acid, sebacic acid, etc. Then, a web made of latently crimpable fibers of a combination of PET and modified PET is formed using a web forming means such as a carding machine, the fibers of this web are entangled by the spunlace method to form a nonwoven fabric, and this is heated to a predetermined temperature to cause the latently crimpable fibers to crimp, thereby producing the nonwoven fabric of the skin side layer 2 and the non-skin side layer 3. As a result, the basis weight of the latently crimped fibers in the nonwoven fabric after heating is greater than the basis weight of the latently crimpable fibers in the nonwoven fabric before heating. In other words, the nonwoven fabric shrinks due to the crimping of the latently crimpable fibers, and the basis weight of the fibers increases.

The skin-side layer 2 and the non-skin-side layer 3 are each an absorbent layer 10 having a predetermined thickness that is liquid-permeable and has the functions of absorbing and retaining liquid. Figure 4 is a diagram explaining the absorbent layer 10 of the napkin 1. In the napkin 1, the skin-side layer 2 is a skin-side sheet that contacts the wearer's skin, and is a member that first receives excrement when worn, absorbs the received excrement within the skin-side layer 2, and then allows it to permeate toward the non-skin side. The non-skin-side layer 3 is a member that absorbs and retains the excrement that has permeated from the skin-side layer 2.

As shown in FIG. 5, the skin side layer 2 and the non-skin side layer 3 each have a void formed by a plurality of fibers (latently crimped fibers) 2f, 3f. FIG. 5A is a schematic diagram of the cross section of the skin side layer 2, and FIG. 5B is a schematic diagram of the cross section of the non-skin side layer 3, and the dimensions are not necessarily accurate. The voids in the skin side layer 2 and the non-skin side layer 3 may be voids between discontinuous fibers (a plurality of fibers), voids formed by a single continuous fiber being curved or spiral, or voids formed by a combination of these. The voids formed by a plurality of fibers 2f, 3f refer to spaces/areas in the skin side layer 2 and the non-skin side layer 3 where a plurality of fibers 2f, 3f are not provided. The voids may be not only spaces surrounded by the fibers 2f, 3f or spaces closed by the fibers, but also spaces that are at least partially open in the voids formed by the fibers 2f, 3f.

The skin-side layer 2 and the non-skin-side layer 3 each contain latent crimped fibers 2f and 3f, and thus form a spiral shape in which the fibers 2f and 3f and the fibers 2f and 3f are entangled as they are crimped. For example, the distance between the fibers 2f and 3f and the fibers 2f and 3f is shortened by crimping, and another fiber is inserted between the shortened fibers 2f and 3f and the fibers 2f and 3f, further reducing the gap between the fibers 2f and 3f and the fibers 2f and 3f. Therefore, the gap formed by the fibers 2f and 3f containing latent crimped fibers is smaller than the gap formed by multiple fibers in a general nonwoven fabric formed from non-crimped fibers.

In addition, the latent crimped fibers 2f, 3f provided in the skin side layer 2 and the non-skin side layer 3, respectively, are not likely to absorb liquid into the fibers themselves. For example, fibers such as pulp fibers absorb liquid (excrement) and become thicker, but the latent crimped fibers 2f, 3f of the skin side layer 2 and the non-skin side layer 3 are not likely to absorb liquid into the inside of the fibers even when they come into contact with liquid. Therefore, in the skin side layer 2 and the non-skin side layer 3, even when the napkin 1 absorbs excrement when worn, the latent crimped fibers 2f, 3f of the skin side layer 2 and the non-skin side layer 3 are not likely to become thicker. Because the fibers themselves are not likely to become thicker, the size of the voids formed by the fibers 2f, 3f is not likely to become smaller, and the voids are not likely to be crushed. For this reason, the skin side layer 2 and the non-skin side layer 3 can retain liquid (excrement) in the voids formed by the fibers 2f and 3f, and therefore the skin side layer 2 and the non-skin side layer 3 are layers that are permeable to liquid and can absorb and retain liquid. In addition, the skin side layer 2 and the non-skin side layer 3 are nonwoven fabric sheets formed by the fibers 2f and 3f, respectively, and have excellent breathability due to the voids formed by the fibers 2f and 3f, and can reduce stuffiness and rough skin caused to the wearer when worn, improving comfort when worn.

As described above, the latent crimp fiber 2f in the skin side layer 2 is a latent crimp fiber that is a combination of PET and modified PET, and the same fiber thickness is used throughout the entire area. In this embodiment, the latent crimp fiber 2fa has a thickness of 2.2 dtex. The average narrowness of the gaps in the skin side layer 2 is 104 μm. The proportion of gaps in the skin side layer 2 (the proportion of the area of the skin side layer 2 where the fiber 2f is not provided) is 94%. The basis weight of the skin side layer 2 is approximately 170 gsm. It is preferable to use hydrophobic fibers on the skin side and hydrophilic fibers on the non-skin side in the skin side layer 2.

The latently crimped fibers 3f in the non-skin side layer 3 are all latently crimpable fibers that are a combination of PET and modified PET, and fibers of the same thickness are used throughout the thickness direction. The thickness of the latently crimped fibers 3f in the non-skin side layer 3 of this embodiment is 2.2 dtex. The basis weight of the non-skin side layer 3 is approximately 120 gsm. The basis weight of the fibers 3f in the non-skin side layer 3 is preferably 80 gsm or more and 200 gsm or less.

The non-skin side layer 3 has linear high density parts DH where the density of the fibers 3f is higher than the surrounding area (low density parts DL), and low density parts DL where the density of the fibers 3f is lower than the high density parts DH. The high density parts DH are thinner than the surrounding area (low density parts DL) and the fibers are not fused to each other.

The back sheet 4 is a liquid-impermeable sheet (outer layer) arranged on the non-skin side of the non-skin side layer 3. An example of a liquid-impermeable sheet is a polyethylene (PE) resin film. The side sheet 5 is a sheet that extends outward from both sides in the width direction of the skin side of the skin side layer 2. An example of the side sheet 5 is a hydrophobic air-through nonwoven fabric or a hydrophobic spunbond nonwoven fabric.

The napkin 1 also has a pair of wing portions 1w extending outward in the width direction at approximately the center in the longitudinal direction. The wing portions 1w are formed by the side sheets 5 and the back sheet 4. Note that the napkin 1 does not necessarily have to have the wing portions 1w. If the napkin 1 does not have the wing portions 1w, it may or may not have the side sheets 5.

The napkin 1 also has a compressed portion 20 where the skin side layer 2 and the non-skin side layer 3 are recessed in the thickness direction. The compressed portion 20 can fix the positions of the skin side layer 2 and the non-skin side layer 3 and improve the liquid diffusion properties of the napkin 1.

In the compressed portion 20, the thickness of the napkin 1 is thinner than the surrounding area, and the fiber density of the napkin 1 (skin side layer 2 and non-skin side layer 3) is higher. These comparisons may be made by known methods. Examples of the comparison of the thickness of the napkin 1 include a visual comparison method, and a method in which a dial thickness gauge ID-C1012C manufactured by Mitutoyo Corporation or an equivalent is used to obtain and compare values measured by applying a pressure of, for example, 3.0 gf/cm ² to a target area. Examples of the comparison of the density of the napkin 1 include a comparison method based on an image of a cross section of the napkin 1 cut in the thickness direction and enlarged by an electron microscope or the like. The shape of the compressed portion 20 is not limited to that shown in FIG. 1. For example, a plurality of dot-like compressed portions may be arranged discretely.

<<<About the Absorbing Layer 10>>>
As described above, the napkin 1 has an absorbent layer 10 (skin side layer 2, non-skin side layer 3), a back sheet 4, and a side sheet 5 (see FIG. 3, etc.). In the center in the width direction, the napkin has the skin side layer 2 provided closest to the skin, the non-skin side layer 3 provided closer to the skin than the skin side layer 2, and a liquid-impermeable back sheet (outer layer) 4 provided closer to the skin than the non-skin side layer 3. The skin side layer 2 has a plurality of fibers 2f including latently crimped fibers, and the non-skin side layer 3 has a plurality of fibers 3f including latently crimped fibers. In the skin side layer 2 and the non-skin side layer 3, the plurality of fibers 2f and fibers 3f are not fused to each other. In other words, the fibers 2f of the skin side layer 2 and the fibers 3f of the non-skin side layer 3 are not fused by melting the fibers 2f, 3f, and the skin side layer 2 and the non-skin side layer 3 are nonwoven fabric sheets formed by closely intertwining each of the independent fibers 2f, 3f. The skin side layer 2 and the non-skin side layer 3 can hold excrement (liquid) in the gaps formed by the multiple fibers 2f, 3f, respectively, and therefore the skin side layer 2 and the non-skin side layer 3 are absorbents (absorbent layers) capable of absorbing excrement.

If the fibers 2f of the skin-side layer 2 or the fibers 3f of the non-skin-side layer 3 are fused, the fused portions will have collapsed voids, which may reduce the absorption function, or the fusion of the fibers 2f and 3f may cause the skin-side layer 2 and the non-skin-side layer 3 to become hard. Furthermore, if the skin-side layer 2 and the non-skin-side layer 3 become hard, wrinkles are more likely to form on the skin-side surface of the absorbent article when the absorbent article is folded or compressed during packaging, or when the absorbent article is worn and a force is applied to the absorbent article due to the wearer's weight or movement. If wrinkles are formed on the skin-side surface of the absorbent article, not only will the aesthetic appearance of the absorbent article be diminished, but there is also a risk that excrement will flow along the wrinkles or the absorbent article will bend in an unintended portion during wearing, causing excrement to leak from the absorbent article.

In contrast, in the napkin 1, the multiple fibers 2f, 3f are not highly fused in the skin side layer 2 and the non-skin side layer 3, so that the decrease in the absorption function (absorption capacity) of the skin side layer 2 and the non-skin side layer 3 can be reduced. In addition, the risk that the skin side layer 2 and the non-skin side layer 3 will become hard due to the fusion of the fibers 2f, 3f can be reduced. Furthermore, since the skin side layer 2 is formed of the fibers 2f containing latent crimped fibers and the non-skin side layer 3 is formed of the fibers 3f containing latent crimped fibers, the flexibility of the fibers 2f, 3f can reduce the risk that the absorbent layer 10 will become excessively hard. Since the skin side layer 2 located closest to the skin has the fibers 2f containing latent crimped fibers, the fibers 2f can make it difficult for wrinkles to form on the skin side of the skin side layer 2. In other words, the fibers 2f containing latent crimped fibers have spiral (coil) fibers, so that the skin side layer 2 is easily made soft and supple. Therefore, the skin-side layer 2 is more elastic than a sheet or layer that does not contain latent crimp fibers, and the skin-side layer 2 is less likely to wrinkle or crease. Also, in the non-skin-side layer 3, the fibers 3f containing latent crimp fibers are spiral (coil) fibers, which makes the non-skin-side layer 3 soft and supple. The napkin 1 having the skin-side layer 2 and the non-skin-side layer 3 can be easily absorbed by the fibers 2f and 3f even when the napkin 1 is folded (folded) in a packaged state or compressed, or when a force is applied to the napkin 1 due to the wearer's body shape or weight when worn, so that the napkin 1 is less likely to wrinkle on the skin-side surface. By making the napkin 1 less likely to wrinkle, the appearance of the napkin 1 can be improved and the risk of excrement leaking from the napkin 1 can be reduced. Furthermore, when worn, wrinkles in the napkin 1 can become folding starting points, reducing the risk of the napkin 1 folding in a position contrary to the wearer's intention, causing discomfort to the wearer.

In addition, the skin-side layer 2 is provided closest to the skin in the center of the width of the napkin 1, and it is preferable that no sheet member or the like is provided on the skin side of the skin-side layer 2 in the center of the width of the napkin 1. However, a sheet member that is clearly thinner than the thickness of the absorbent layer 10 (skin-side layer 2 and non-skin-side layer 3) may be placed on the skin side of the skin-side layer 2 in the center of the width. As a sheet member that is clearly thinner than the absorbent layer 10, it is sufficient that the sheet member has a basis weight of 1/10 or less of the basis weight of the absorbent layer 10 (skin-side layer 2 and non-skin-side layer 3). If such a sheet member is clearly thinner than the absorbent layer 10, wrinkles and folds are unlikely to form in the thin sheet member located on the skin side of the skin-side layer 2 even if force is applied to the napkin 1 in the worn or packaged state. Therefore, in the center of the width of the napkin 1, if a sheet member having a basis weight of 1/10 or less of the basis weight of the fibers 2f, 3f of the absorbent layer 10 (skin side layer 2 and non-skin side layer 3) is provided closer to the skin than the skin side layer 2, the skin side layer 2 is considered to be "provided closest to the skin."

It is preferable that the latent crimp fibers 2f, 3f of the skin side layer 2 and the non-skin side layer 3 are fibers made of a single resin composition. In particular, it is more preferable that the latent crimp fibers 2f, 3f are fibers made of polyethylene terephthalate (PET).

The skin side layer 2 and non-skin side layer 3, which use latent crimped fibers 2f, 3f made of a single-component resin, particularly polyethylene terephthalate (PET), tend to have uniform physical properties. This makes it easier to make the nonwoven fabrics of the skin side layer 2 and non-skin side layer 3 into sheet members with approximately uniform properties, making it less likely for wrinkles to form on the skin side of the napkin 1. In addition, by using a single-component resin (e.g., polyethylene terephthalate) for the skin side layer 2 and non-skin side layer 3, the number of parts required for manufacturing the napkin 1 can be reduced, reducing the manufacturing costs of the napkin 1 and improving the workability of manufacturing and recycling.

The non-skin side layer 3 preferably has a linear high density portion DH where the density of the fibers 3f is higher than the surrounding area. It also has a low density portion DL where the density of the fibers 3f is lower than the high density portion DH. As described above, in the non-skin side layer 3, the fibers 3f are not fused to each other and are thinner than the surrounding area (low density portion DL). Figure 6 is an enlarged view of portion X in Figure 4. Figure 7 is a schematic cross-sectional view taken along the arrows B-B in Figure 6.

The narrower the gap between the fibers, the easier it is for the excrement (liquid) to diffuse. Therefore, in the high density portion DH, the fibers 3f are not fused to each other, which reduces the risk of impeding the diffusion of the absorbed liquid (excrement) compared to when the fibers are fused to each other. In addition, since the non-skin side layer 3 is an absorbent formed of a nonwoven fabric with latent crimped fibers, the shape of the multiple fibers is maintained by intertwining, making it easier to maintain the shape of the gaps formed by the multiple fibers. In addition, it is possible to reduce the risk of the non-skin side layer 3 absorbing liquid and expanding like pulp fibers, thereby crushing the gaps formed by the fibers 3f. Therefore, after absorbing the liquid (excrement), the non-skin side layer 3 maintains the gaps between the fibers 3f, and the capillary phenomenon caused by the high density portion DH makes it easier to draw the liquid into the high density portion DH, making it easier to diffuse the absorbed liquid within the non-skin side layer 3. Furthermore, by facilitating diffusion within the non-skin side layer 3, the risk of excrement absorbed by the napkin 1 remaining in the skin side layer 2 or excrement that has once reached the non-skin side layer 3 returning to the skin side layer 2 during wear can be reduced, which may cause discomfort to the wearer. In addition, the high density portion DH is surrounded by a low density portion DL having a lower fiber density than the high density portion. The low density portion DL is softer than the high density portion DH. In addition, in this embodiment, it is thicker than the high density portion DH. That is, as shown in FIG. 7, the thickness direction length H3 of the low density portion DL is longer than the thickness direction length Hdh of the high density portion DH (Hdh<H3). Therefore, the force applied to the napkin 1 can be easily buffered by the low density portion DL provided around the high density portion DL in the non-skin side layer 3. This reduces the risk that the force applied to the napkin 1 will concentrate on the skin side of the napkin 1, making it easier to prevent wrinkles from occurring.

A "linear" high density portion DH is not limited to a portion in which portions with a higher density than the surrounding area are connected in a linear fashion. When multiple high density portions are arranged intermittently in a linear or dotted fashion, the linear high density portion DH includes the areas between the multiple adjacent high density portions. Although the areas between adjacent high density portions that are close to each other have a lower fiber density than the portions formed as high density portions, they are areas with a higher fiber density than the surrounding area, and therefore form a linear high density portion as a whole.

The high density portion DH of the napkin 1 of this embodiment is a plurality of high density portions DL arranged at a predetermined interval in the width direction, each of which is continuous in the longitudinal direction from the upper end to the lower end of the non-skin side layer 3. The high density portions DL continuous in the longitudinal direction have a wave-like shape with alternating concave and convex portions on both sides in the width direction. As shown in FIG. 7, in the napkin 1 of this embodiment, the length in the thickness direction of the low density portion DL is the length H3 in the thickness direction of the non-skin side layer 3, and the length Hdh in the thickness direction of the high density portion DH is shorter than the length H3 in the thickness direction of the low density portion DL (Hdh<H3). The thicknesses of the high density portion DH and the low density portion DL of the non-skin side layer 3 can be compared by a known method, and can be measured, for example, by the method described above.

The high density portion DL can be formed, for example, during the manufacturing process of the non-skin side layer 3, by sandwiching and transporting a nonwoven fabric sheet having a substantially uniform thickness between a pair of rolls. One of the pair of rolls is a heat embossing roll having a convex portion on its outer peripheral surface, and the other roll is an anvil roll having a smooth outer peripheral surface. By setting the heating temperature of the fibers 3f by the heat embossing roll to a temperature higher than the softening point and lower than the melting point of the latent crimped fibers of the fibers 3f of the non-skin side layer 3, it becomes easier to maintain a form thinner than the low density portion DL in the high density portion DH without fusing the fibers 3f in the high density portion DH.

It is also preferable that the skin side of the non-skin side layer 3 has a recess DH recessed in the thickness direction. In the napkin 1 of this embodiment, the high density portion DH is the recess DH. The recess DH of the non-skin side layer 3 can provide a portion separated from the skin side layer 2, so that the risk of excrement once absorbed by the non-skin side layer 3 returning to the skin side layer 2 can be reduced. This reduces the discomfort felt by the wearer's skin. In addition, by having the recess DH on the skin side of the non-skin side layer 3, when force is applied to the napkin 1, the non-skin side layer 3 is more likely to deform due to the difference in rigidity between the recess DH of the non-skin side layer 3 and the low density portion DL than when the skin side of the non-skin side layer 3 is flat. Therefore, the force applied to the napkin 1 is more easily buffered by the non-skin side layer 3, which reduces the risk of force concentrating on the skin side layer 2 of the napkin 1, making it easier to prevent wrinkles from occurring on the skin side of the napkin 1.

The non-skin side layer 3 of the napkin 1 has a recess on the skin side that is recessed toward the non-skin side, and the non-skin side has a flat surface, but this is not limited to this. The non-skin side layer 3 may have recesses on both the skin side and the non-skin side. Also, when viewed in the thickness direction, the recess on the skin side and the recess on the non-skin side may be located in the same position or in different positions. Furthermore, the recess DH of the non-skin side layer 3 of the napkin 1 is the high density portion DH, but this is not limited to this. For example, the recess DH may be a portion having the same fiber density as the low density portion DL.

The napkin 1 is superimposed with the skin-side layer 2 and the non-skin-side layer 3 in contact with each other. The skin-side layer 2 and the non-skin-side layer 3 may be fixed with an adhesive such as a hot melt adhesive, or may not be provided with an adhesive. In particular, by not providing an adhesive between the skin-side layer 2 and the non-skin-side layer 3 in the center of the width direction when viewed in the thickness direction of the napkin 1, it is possible to reduce the risk that the adhesive will hinder the absorption of excrement when worn. In addition, if an adhesive is provided between the skin-side layer 2 and the non-skin-side layer 3, the fibers of the skin-side layer 2 and the fibers of the non-skin-side layer 3 are fixed with the adhesive, so that the fibers 2f of the skin-side layer 2 and the fibers 3f of the non-skin-side layer 3 are restricted in movement and deformation. In addition, the part fixed with the adhesive is likely to have increased rigidity. Therefore, if an adhesive is provided between the skin side layer 2 and the non-skin side layer 3, the force applied to the napkin 1 tends to concentrate on the part where the skin side layer 2 and the non-skin side layer 3 are fixed with the adhesive, and the locally concentrated force tends to cause wrinkles on the skin side of the napkin 1. In contrast, if no adhesive is provided between the skin side layer 2 and the non-skin side layer 3, the fibers of the skin side layer 2 and the fibers of the non-skin side layer 3 are not fixed with the adhesive, so that the fibers 2f of the skin side layer 2 and the fibers 3f of the non-skin side layer 3 can be prevented from being restricted in movement or deformation. The rigidity of the fibers 2f of the skin side layer 2 and the fibers 3f of the non-skin side layer 3 is prevented from increasing due to the adhesive. In this way, by not providing an adhesive between the skin side layer 2 and the non-skin side layer 3, the risk of wrinkles occurring on the skin side of the napkin 1 due to the locally concentrated force at the fixed part between the skin side layer 2 and the non-skin side layer 3 can be reduced.

As shown in FIG. 5 and the like, it is preferable that the thickness H2 of the skin-side layer 2 is thicker than the thickness H3 of the non-skin-side layer 3 (H2>H3). By making the thickness H2 of the skin-side layer 2 thicker than the thickness H3 of the non-skin-side layer 3, the non-skin-side layer 3 can be kept farther away from the wearer's skin when worn than when the thickness H2 of the skin-side layer 2 is thinner than the thickness H3 of the non-skin-side layer 3. This reduces the risk that excrement once absorbed by the non-skin-side layer 3 will return to the skin-side surface of the skin-side layer 2. In addition, the thickness of the skin-side layer 2 that contacts the wearer's skin is thick, which improves the skin contact of the napkin 1 when worn. In addition, by making the thickness H2 of the skin-side layer 2 thicker than the thickness H3 of the non-skin-side layer 3, it is more difficult to fold the skin-side layer 2 than when the thickness H2 of the skin-side layer 2 is thinner than the thickness H3 of the non-skin-side layer 3, making it easier to prevent wrinkles from forming on the skin-side surface of the napkin 1.

As shown in FIG. 5A, when the skin side layer 2 is divided into three equal parts in the thickness direction, with the region closest to the skin being the skin side region Ru, the region closest to the skin being the non-skin side region Rd, and the region between the skin side region Ru and the non-skin side region Rd being the intermediate region Rm, the average narrowness of the non-skin side region Rd in a narrowness evaluation test for quantitatively evaluating the narrowness of the gaps formed by the fibers 2f is narrower than the average narrowness of the skin side region Ru in a narrowness evaluation test. As a result, the non-skin side region Rd is more likely to draw in liquid due to capillary action than the skin side region Ru.

The latent crimped fibers in the skin-side layer 2 of the napkin 1 have a property that the fibers 2f themselves are less likely to absorb liquid (excrement) than liquid-absorbent fibers such as pulp fibers. Therefore, by having the fibers 2f with latent crimped fibers in the skin-side layer 2, even if the napkin absorbs excrement while being worn, the fibers 2f themselves are less likely to thicken and the gaps formed by the fibers 2f can be maintained even if the napkin absorbs excrement while being worn. Furthermore, since the average narrowness of the non-skin-side region Rd in the narrowness evaluation test is narrower than the average narrowness of the skin-side region Ru in the narrowness evaluation test, the excrement received on the skin side of the skin-side region Ru while being worn is more likely to be drawn toward the non-skin-side region Rd by capillary action. Also, the excrement drawn into the non-skin-side region Rd is more likely to be diffused over a wide area within the non-skin-side region Rd. This reduces the risk of the excrement being in contact with the wearer's skin, causing discomfort to the wearer, and causing rough skin, when the excrement absorbed from the skin side of the skin side region Ru remains on the skin side of the skin side region Ru or within the skin side region Ru when worn. In addition, even if a large amount of excrement is discharged at once, the excrement is more likely to be diffused from the skin side region Ru toward the non-skin side region Rd, reducing the risk of excrement leaking from the napkin 1 along the surface of the skin side region Ru. Furthermore, the average narrowness of the non-skin side region Rd in the narrowness evaluation test is narrower than the average narrowness of the skin side region Ru in the narrowness evaluation test, making it easier to diffuse excrement from the skin side to the non-skin side within the skin side layer 2, and easier to diffuse excrement from the skin side layer 2 toward the non-skin side layer 3, reducing the amount of excrement remaining on the skin side of the skin side layer 2 and improving comfort for the wearer when worn.

In addition, in the skin-side layer 2, the average narrowness of the non-skin-side region Rd in the narrowness evaluation test is made narrower than the average narrowness of the skin-side region Ru in the narrowness evaluation test to promote diffusion from the skin-side region Ru to the non-skin-side region Rd, thereby narrowing the diffusion area of excrement in the skin-side region Ru and widening the diffusion area of excrement in the non-skin-side region Rd compared to when the average narrowness of the non-skin-side region Rd in the narrowness evaluation test is wider than the average narrowness of the skin-side region Ru in the narrowness evaluation test. This makes it easier to promote diffusion of excrement from the skin-side layer 2 to the non-skin-side layer 3, and easier to promote diffusion of excrement in the non-skin-side layer 3, so that as shown in Figure 8, it is easier to make the diffusion area B3 of excrement in the non-skin-side layer 3 wider than the diffusion area B2 of excrement in the skin-side layer 2. Figure 8 is a diagram illustrating the napkin 1 30 minutes after horse blood is dripped. Figure 8 is a diagram explaining the state of the napkin 1 after 30 minutes have passed since 6 mm of horse blood was dropped onto the center of the length and width of the napkin 1. In this way, the area of the excrement diffusion area B3 in the non-skin side layer 3 is larger than the area of the excrement diffusion area B2 in the skin side layer 2, which makes it easier to give the impression to the user that the napkin 1 has excellent absorbency.

Furthermore, generally, the narrower the gaps formed by the fibers 2f, the denser the fiber structure becomes, making it more difficult for the fibers 2f to move, and the easier it is for the fibers 2f (skin-side layer 2) to recover from the shape of the fibers when force is applied to them. The skin-side layer 2 is a nonwoven fabric sheet, and since the fibers 2f are entangled with each other to form a sheet, the denser the fiber structure, the more restricted the movement of the entangled fibers 2f becomes, and when force is applied to the skin-side layer 2 from the outside, the degree of freedom of the fibers 2f decreases, making it more difficult for the fibers 2f to recover from the original shape. In contrast, by making the average narrowness of the skin-side region Ru larger than the average narrowness of the non-skin-side region Rd, the fiber structure of the skin-side region Ru is less dense and the fibers are more easily moved, which improves the recovery of the fibers 2f when force is applied to the fibers 2f. This reduces the risk of wrinkles and creases forming in the skin-side region Ru compared to the non-skin-side region Rd, making it easier to reduce wrinkles and creases that occur on the skin-side surface of the napkin 1.

As described above, in the napkin 1 of this embodiment, the nonwoven fabric sheet of the skin side layer 2 is formed by the spunlace method, and by applying a water flow from the skin side to the non-skin side, the fibers 2f are easily pushed from the skin side to the non-skin side, and the average narrowness of the non-skin side region Rd in the narrowness evaluation test becomes narrower than the average narrowness of the skin side region Ru in the narrowness evaluation test. Note that the method of making the average narrowness of the non-skin side region Rd in the narrowness evaluation test narrower than the average narrowness of the skin side region Ru in the narrowness evaluation test is not limited to this. For example, the thickness (fiber diameter) of the fibers 2f in the non-skin side region Rd may be made thinner than the thickness (fiber diameter) of the fibers 2f in the skin side region Ru. In addition, the fibers 2f used in the non-skin side region Rd may be latent crimp fibers that have a stronger crimping property than the fibers 2f used in the skin side region Ru, so that the average narrowness of the non-skin side region Rd in the narrowness evaluation test may be narrower than the average narrowness of the skin side region Ru in the narrowness evaluation test.

It is preferable that the ratio of voids in the non-skin side region Rd in the void ratio evaluation test for quantitatively evaluating the ratio of voids in the measurement region Y is smaller than the ratio of voids in the skin side region Ru in the void ratio evaluation test. The void ratio evaluation test can be performed by the method described below. As a result, when the napkin 1 (skin side layer 2) absorbs excrement, it becomes easier to draw the excrement from the skin side region Ru to the non-skin side region Rd, which has a smaller ratio of voids, by capillary action, and it becomes easier to promote the diffusion of excrement from the skin side region Ru to the non-skin side region Rd. It also becomes easier to promote the diffusion of excrement in the non-skin side region Rd. As a result, it becomes easier to reduce the amount of excrement remaining in the skin side region Ru when worn, and it is possible to reduce the discomfort caused by excrement contacting the wearer's skin. In general, the smaller the void ratio of the fibers 2f, the denser the fiber structure becomes, making the fibers 2f less likely to move, and the fiber shape recovery when force is applied to the fibers 2f (skin side layer 2) is likely to be reduced. On the other hand, by making the void ratio of the skin side region Ru larger than the void ratio of the non-skin side region Rd, the fiber structure of the skin side region Ru is less likely to become dense and the fibers are more likely to move, improving the recovery of the fibers 2f when force is applied to the fibers 2f, compared to when the void ratio of the skin side region Ru is smaller than the void ratio of the non-skin side region Rd. This reduces the risk of wrinkles and creases forming in the skin side region Ru compared to the non-skin side region Rd, making it easier to reduce wrinkles and creases that occur on the skin side of the napkin 1.

In the napkin 1 of this embodiment, as described above, the nonwoven fabric sheet of the skin side layer 2 is formed by the spunlace method, and by applying a water flow from the skin side to the non-skin side, the fibers 2f are pushed from the skin side to the non-skin side, so that the void ratio of the non-skin side region Rd in the void ratio evaluation test is smaller than the void ratio of the skin side region Ru in the void ratio evaluation test. Note that the method of making the void ratio of the non-skin side region Rd in the void ratio evaluation test smaller than the void ratio of the skin side region Ru in the void ratio evaluation test is not limited to this. For example, the thickness (fiber diameter) of the fibers 2f in the non-skin side region Rd may be made thinner than the thickness (fiber diameter) of the fibers 2f in the skin side region Ru. In addition, by using a latent crimp fiber that has a stronger shrinkage property than the fiber 2f used in the skin side region Ru for the fiber 2f used in the non-skin side region Rd, the void ratio of the non-skin side region Rd in the void ratio evaluation test may be made smaller than the void ratio of the skin side region Ru in the void ratio evaluation test.

<Narrowness evaluation test method and void ratio evaluation test method>
The narrowness evaluation test and void ratio evaluation test (described later) of the skin side layer 2 of the napkin 1 of this embodiment were carried out by Toray Research Center, Inc.
The narrowness evaluation test and the void ratio evaluation test can be carried out, for example, by the following method.

First, X-ray CT measurement is performed on the skin side layer 2. Non-destructive tomography (CT measurement) is performed under the following conditions using a high-resolution 3D X-ray microscope nano3DX manufactured by Rigaku Corporation.
X-ray source: Cu
Tube voltage-tube current: 40kV-30mA
Detector: sCMOS camera (lens: 1080)
Resolution: 2.51 μm/voxel

A measurement area (predetermined area) Y of the skin-side layer 2 is randomly extracted from the three-dimensional data obtained by photography, and the voids are analyzed. The measurement area Y for this analysis is a rectangular parallelepiped (or cube) whose length in the thickness direction is the thickness H2 of the skin-side layer 2, within any range in the surface direction of the skin-side layer 2.

In this embodiment, as shown in FIG. 9, when the measurement area Y is divided into three equal parts in the thickness direction, the lowest part is the first area Y1, the highest part is the third area Y3, and the part between the first area Y1 and the third area Y3 is the second area Y2. FIG. 9 is a diagram explaining the measurement area Y, in which the fibers 2f are the colored (gray) parts, the voids are the colored (white) parts, and the lattice part shows the range of the measurement area randomly extracted from the skin side layer 2. The first area Y1 is the skin side area Ru of the skin side layer 2 (a part of the skin side area Ru when viewed in the thickness direction), the second area Y2 is the middle area Rm of the skin side layer 2 (a part of the middle area Rm when viewed in the thickness direction), and the third area Y3 is the non-skin side area Rd of the skin side layer 2 (a part of the non-skin side area Rd when viewed in the thickness direction).

In the cross-sectional image obtained by X-ray CT, low-density (void) components that easily transmit X-rays are displayed in black, and high-density (fiber) components that easily absorb X-rays are displayed in white. From this image, the void ratio and average void narrowness of each region Y1 to Y3 are calculated.

The void ratio of each of the regions Y1 to Y3 can be calculated by obtaining the volume of the void in each of the regions Y1 to Y3 and the volume of the measurement region Y from a tomographic image obtained by X-ray CT. For example, the void ratio of the first region Y1 is as follows.
Void ratio of first region Y1=(volume of void in first region Y1)/(volume of first region Y1)
The volume of the first region Y1 is the sum of the volume of the fibers in the first region Y1 and the volume of the voids in the first region Y1.

The narrowness of the gaps in each of the regions Y1 to Y3 is calculated by applying the thickness of "A new method for the model-independent assessment of thickness in three-dimensional images" (T. HILDEBRANDO & P. RUEGSEGGER, Journal of Microscopy, Vol. 185, Pt1, January 1997, pp. 67-75) to the spatial portion, and the distribution of gap narrowness and the average gap narrowness are calculated based on the results of the partial narrowness of the volume (gap). In other words, the "thickness" in the definition in the above-mentioned document corresponds to the "narrowness of the voids" in the skin-side layer 2 (each of the regions Y1 to Y3), and by identifying the narrowness in each part of the volume portion that corresponds to the voids in the tomographic image obtained by X-ray CT, the distribution of the narrowness of the voids and the average narrowness of the voids can be obtained.

The following describes an outline of a quantitative evaluation method for the narrowness of a gap (for example, gap Z) inside each of the regions Y1 to Y3 to be analyzed. FIG. 10 is a diagram for explaining an outline of a method for evaluating the narrowness of gap Z. For example, as shown in FIG. 10, at any points P1 to P4 inside gap Z, the largest sphere in the region including each point is assumed, and a process is performed to obtain the diameters D1 to D4 of each sphere. Note that the process of obtaining the diameters D1 to D4 of the spheres at four points (points P1 to P4) was described using FIG. 10, but in an actual quantitative evaluation of the narrowness of a gap, a process is performed to obtain the diameters D of the spheres at multiple points P inside gap Z. This process is performed at all points in each of the regions Y1 to Y3, the distribution of the obtained diameters is calculated, and the average value is obtained, so that the average narrowness of the gaps in each of the regions Y1 to Y3 can be quantitatively evaluated.

Figure 11 shows the results of the narrowness evaluation test and the void ratio evaluation test. Figure 11 shows the average gap narrowness (μm), minimum gap narrowness (μm), maximum gap narrowness (μm), standard deviation, and void ratio (%) in each of the measurement area Y, the first area Y1, the second area Y2, and the third area Y3 obtained by the above-mentioned measurement. In this embodiment, the average gap narrowness of the first area Y1 of the measurement area Y is 117 μm, and the average gap narrowness of the third area Y3 is 91 μm, so it is clear that the average gap narrowness of the third area Y3 is narrower than the average gap narrowness of the first area Y1. From this result, it can be seen that the average narrowness of the non-skin side area Rd in the narrowness evaluation test is narrower than the average narrowness of the skin side area Ru in the narrowness evaluation test.

For the skin-side layer 2, when at least a part of the fibers 2f in the non-skin-side region Rd is more hydrophilic than the fibers 2f in the skin-side region Ru, it is preferable that a part of the fibers 2f in the non-skin-side region Rd is exposed on the skin-side surface of the skin-side layer 2. Specifically, as shown in FIG. 5A, it is preferable that the skin-side layer 2 has hydrophilic fibers 2fb in the non-skin-side region that are more hydrophilic than the fibers 2f in the skin-side region Ru, and has hydrophilic fibers 2fb exposed on the skin-side surface of the skin-side layer 2. The hydrophilicity of each region is determined based on the contact angle with water. The measurement of the contact angle between each region and water will be described later. The hydrophilic fibers 2fb exposed on the skin-side surface of the skin-side layer 2 are more likely to draw in the excrement absorbed from the skin-side toward the non-skin-side region Rd. This makes it easier to promote the diffusion of excrement from the skin side to the non-skin side in the skin side layer 2, and also makes it easier to promote the diffusion of liquid in the non-skin side region Rd, reducing the risk of excrement remaining on the skin side (surface) of the skin side region Rd, reducing the discomfort caused by excrement continuing to come into contact with the wearer's skin, and improving comfort when worn.

In the process of forming the nonwoven fabric sheet, the skin-side layer 2 of this embodiment is formed by subjecting the hydrophobic fibers 2fa of the skin-side region Ru and the hydrophilic fibers 2fb of the non-skin-side region Rd to a high-pressure water jet treatment, etc., in a laminated state, to entangle the fibers between the fiber layers and the fibers between the webs (step (d) of forming a nonwoven fabric by the spunlace method described above). At this time, the water flow that passes through the hydrophobic fibers 2fa and the hydrophilic fibers 2fb in that order is reflected by the conveyor belt and moves toward the skin side in the order of the hydrophilic fibers 2fb and the hydrophobic fibers 2fa, so that the hydrophilic fibers 2fb are pulled up toward the skin-side region Ru. This provides the hydrophilic fibers 2fb exposed on the skin-facing surface of the skin-side layer 2.

The method of providing the hydrophilic fibers 2fb exposed on the skin-facing surface of the skin-side layer 2 is not limited to this. Any well-known method can be used. For example, the fibers 2f may be intertwined with each other by the spunlace method, and then the hydrophilic fibers 2fb may be exposed on the skin-facing surface of the skin-side layer 2 by the needle punch method.

It is also preferable that the hydrophilicity of the skin side layer 2 is lower than that of the non-skin side layer 3. As shown in FIG. 5A, the skin side layer 2 of this embodiment includes an upper layer 2A formed mostly of hydrophobic fiber 2fa and a lower layer 2B formed mostly of hydrophilic fiber 2fb. The fiber 2fb has a higher hydrophilicity than the fiber 2fa. The hydrophobic fiber 2fa is provided on the skin side, and the hydrophilic fiber 2fb is provided on the non-skin side. The non-skin side layer 3 is formed of hydrophilic fiber 3f (FIG. 5B). The skin side layer 2 has a higher hydrophobicity, and the non-skin side layer 3 has a higher hydrophilicity than the skin side layer 2. This reduces the retention of excrement absorbed by the skin side layer 2 in the worn state, and makes it easier to draw it toward the non-skin side layer 3. In addition, excrement that reaches the non-skin side layer 3 can be easily diffused within the non-skin side layer 3, reducing the risk of excrement returning from the non-skin side layer 3 to the skin side layer 2. This reduces the risk of excrement remaining in contact with the wearer's skin.

The hydrophilicity of each layer is judged based on the contact angle with water. The contact angle between each layer and water can be measured by the following method.
First, a rectangular shape in plan view with a length of 150 mm and a width of 70 mm is cut out from each region (layer) to be measured to obtain a measurement sample (if it is difficult to cut out, the maximum length and maximum width are not limited to the example values as long as they are within the range that can be measured). Then, a droplet of ion-exchanged water is attached to the surface to be measured for the contact angle of each measurement sample, the droplet is recorded, and the contact angle is measured based on the recorded image. More specifically, a microscope VHX-1000 manufactured by Keyence Corporation is used as the measurement device, and a medium-magnification zoom lens is attached to it in a state in which it is tilted at 90°. Each measurement sample is set on the measurement stage of the measurement device so that the surface to be measured faces upward and can be observed from the width direction of each measurement sample. Then, a droplet of 3 μL of ion-exchanged water is attached to the surface to be measured of each measurement sample set on the measurement stage, and an image of the droplet is recorded and taken into the measurement device. From the recorded images, 10 images in which both ends or one end of the droplet in the width direction are clear are selected, the contact angle of the droplet is measured for each of the 10 images, and the average of the contact angles is taken as the contact angle of the measurement target area (fiber layer). The measurement environment is 20°C/50% RH.

The smaller the contact angle with water measured by the above method, the higher the hydrophilicity (lower hydrophobicity), and the larger the contact angle, the lower the hydrophilicity (higher hydrophobicity). If the contact angle is less than 90 degrees, it is hydrophilic, and if it is 90 degrees or more, it is hydrophobic. In other words, the contact angle with the skin-side layer 2 is greater than the contact angle with water of the non-skin-side layer 3.

In this embodiment, the skin side layer 2 has hydrophobic fiber 2fa on the skin side in the thickness direction and hydrophilic fiber 2fb on the non-skin side, while the non-skin side layer 3 has hydrophilic fiber 3f, making the hydrophilicity of the skin side layer 2 lower than that of the non-skin side layer 3, but this is not limited to the above. For example, the entire area of each nonwoven fabric sheet of the skin side layer 2 and the non-skin side layer 3 may be formed of fibers 2f and 3f with a constant hydrophilicity, and the skin side layer 2 may be processed to apply a hydrophobic agent, and the non-skin side layer 3 may be processed to apply a hydrophilic agent.

The napkin 1 has a desired absorbency. The absorbency of the napkin 1 can be measured by the following absorption test.
<Method of measuring absorption function>
(1) First, prepare a napkin 1.
(2) Next, when viewed in the thickness direction of the napkin 1, a predetermined region is defined as a central portion in the longitudinal direction and a central portion in the width direction, and this predetermined region is cut out as a sample. In the napkin 1 of this embodiment, the sample has a size of 70 mm x 70 mm.
(3) Then, the weight of this sample, i.e., pre-absorption weight a, is measured using a balance with a sensitivity of 0.01 g. Pre-absorption weight a is the weight of the sample before it absorbs distilled water.
(4) Next, one end of the sample is clamped with a clip so that the tip of the clip and the sample are perpendicular to the vertical direction.
The sample, together with the clip, is immersed in a water tank containing distilled water (or deionized water) at 23±1° C., with the skin side of the absorbent layer 10 facing up. The sample is gently pressed into the water, and the state in which the entire sample is completely immersed in the distilled water is maintained for 60 seconds.
(5) Thereafter, the clip is pulled up, the sample is pulled out of the distilled water, and the sample is clamped with the clip while being completely removed from the water surface of the tank, and the sample is left hanging from the clip for 90 seconds.
(6) Then, the mass of the sample excluding the clip is weighed to obtain the post-absorption weight A, which is the weight of the sample after absorption.
(7) The absorbed weight b is calculated by subtracting the weight a before absorption from the weight A after absorption.
(Absorption weight b) = (Weight after absorption A) - (Weight before absorption a)
It is preferable that the value obtained by dividing the obtained absorption weight b by the weight a before absorption is 5 or more.
Absorption weight b÷weight before absorption a≧5
The above steps (1) to (7) are carried out for each of the five samples, and the average value of the results for the five samples is regarded as the measurement result.

The larger the value obtained by dividing the absorption weight b by the weight before absorption a, the more distilled water the napkin 1 can absorb, and therefore the more excrement it can absorb. By making the value obtained by dividing the absorption weight b by the weight before absorption a 5 or more, the napkin 1 can fully ensure its function for absorbing liquid, compared to when the value obtained by dividing the absorption weight b by the weight before absorption a is less than 5. In other words, the napkin 1 can retain the absorbed liquid within the napkin 1 while reducing the risk of wrinkles and creases on the skin side. In this way, the napkin 1 has a sufficient absorption function for absorbing excrement while making it difficult for wrinkles and creases to form on the skin side, and it is possible to diffuse and retain the absorbed excrement within the napkin 1.

The bending stiffness B of the absorbent layer 10 in the longitudinal center and width center in the state where the skin side layer 2 and the non-skin side layer 3 of the napkin 1 are overlapped is preferably 1.2 gf·cm ² /cm or less as measured by the KES method. In this embodiment, the longitudinal center of the absorbent layer 10 is the crotch region, and the longitudinal center and width center are also the excretory opening contact region when worn. Generally, the greater the value of the bending stiffness B, the greater the bending stiffness. By setting the bending stiffness B of the absorbent layer 10 in the longitudinal center and width center to 1.2 gf·cm ² /cm or less as measured by the KES method, the absorbent layer 10 can be made more flexible than when the bending stiffness B of the absorbent layer 10 in the longitudinal center and width center is greater than 1.2 gf·cm ² /cm, and the napkin 1 using the absorbent layer 10 can be made more flexible. Therefore, even when force is applied to the napkin 1, wrinkles are less likely to form on the skin-side surface of the napkin 1. Furthermore, when worn, the napkin 1 is more likely to follow the shape and movements of the wearer's body, reducing discomfort to the wearer and improving comfort when worn.

<Method for measuring bending rigidity B>
The bending stiffness B (gf·cm ² /cm) at the center of the length and width of the absorbent layer 10 can be measured by a known method. For example, the value of bending stiffness B (gf·cm ² /cm) can be measured using a large bending tester KES-FB2-L manufactured by Kato Tech Co., Ltd. First, the absorbent layer 10 (skin side layer 2 and non-skin side layer 3 are overlapped) is removed from the napkin 1, and a portion of 50 mm×50 mm in the center of the length and width of the absorbent layer 10 is cut out as a sample. This sample is fixed between the chucks of the tester so that it can be measured by bending it along the length of the absorbent layer 10. The measurement is performed by bending it to the front side to a maximum curvature of +0.5 cm ⁻¹ , then bending it to the back side to a maximum curvature of −0.5 cm ⁻¹ , and then returning it to its original state. The bending stiffness value B (gf·cm ² /cm) is calculated from the average value of the gradient of the bending moment for a curvature of 0.1 to 0.3 when bent to the front side and the gradient of the curvature of -0.1 to -0.3 when bent to the back side.

Figure 12A shows the results of measuring the bending properties using the KES method. Figure 12A shows the results of measuring the bending properties using the KES method for the absorbent layer 10 of the napkin 1 of this embodiment and the absorbent body (absorbent layer) of the comparative product X, which is an existing sanitary napkin.

Comparative product X is a sanitary napkin having a conventionally well-known configuration, which is configured from the skin side to the top sheet, absorbent, and back sheet. The top sheet of comparative product X is a sheet member that has excellent liquid permeability but has difficulty absorbing or retaining liquid. The absorbent of comparative product X is a polymer foam structure that can absorb and retain liquid. The back sheet of comparative product X is a liquid-impermeable sheet member. Since the top sheet of comparative product X allows liquid to pass through but has difficulty absorbing or retaining liquid, it was determined that the absorbent layer of comparative product X is only the absorbent, and the absorbent was removed from comparative product X and the bending properties were measured using the above-mentioned KES method at the longitudinal center and width center of comparative product X, in the same manner as napkin 1.

12A, the bending stiffness B (gf· ^cm2 /cm) at the longitudinal center and width center of the absorbent layer 10 of the napkin 1 of this embodiment is 0.1008 to 1.1017 gf· ^cm2 /cm, which is less than 1.2 gf· ^cm2 /cm. In contrast, the bending stiffness B (gf· ^cm2 /cm) at the longitudinal center and width center of the absorbent body of the comparative product X is 0.5493 to 6.1168 gf· ^cm2 /cm. Furthermore, the average value of the measurement results of the bending stiffness B of the absorbent layer 10 of the napkin 1 (0.5390 gf· ^cm2 /cm) is smaller than the average value of the measurement results of the bending stiffness B of the absorbent body of the comparative product X (2.5294 gf· ^cm2 /cm). From these results, it can be seen that the absorbent layer 10 of the napkin 1 is softer than the absorbent body of the comparative product X, and therefore the napkin 1 can be made softer than the comparative product X, and therefore wrinkles are less likely to form in the napkin 1 than in the comparative product X. Furthermore, when worn, the napkin 1 is more likely to conform to the shape and movements of the wearer's body than the comparative product X, thereby reducing the discomfort felt by the wearer and improving comfort when worn.

The bending hysteresis 2HB of the absorbent layer 10 in the napkin 1 at the longitudinal center and the width center is preferably 0.93 gf·cm ² /cm or less as measured by the KES method. The 2HB value indicates bending recovery, and the larger the value of the bending hysteresis 2HB, the worse the recovery. By setting the bending hysteresis 2HB at the longitudinal center and the width center of the absorbent layer 10 at 0.93 gf·cm ² /cm or less as measured by the KES method, the absorbent layer 10 deformed by an external force or the like when worn can be easily restored to its original shape, compared to when the bending hysteresis 2HB at the longitudinal center and the width center of the absorbent layer 10 is greater than ^0.93 gf·cm 2 /cm as measured by the KES method. Therefore, even if force is applied to the napkin 1, the risk of wrinkles being formed on the skin side of the napkin 1 can be reduced. In addition, the sense of incongruity and discomfort felt by the wearer due to deformation of the absorbent layer 10 can be reduced.

<Method of measuring bending hysteresis 2HB>
The bending hysteresis 2HB (bending recovery) can be measured by a known method, for example, using an automated bending tester (KES-FB2-L) manufactured by Kato Tech Co., Ltd.
First, the absorbent layer 10 (the skin side layer 2 and the non-skin side layer 3 overlapped) is removed from the napkin 1, and a portion measuring 50 mm x 50 mm is cut out as a sample from the longitudinal center and width center of the absorbent layer 10.
Next, both ends of the sample in the longitudinal direction are held by chucks. The sample is then bent in both positive and negative directions at a curvature change rate of 0.1 cm-1/min, with a curvature of 0.5 cm-1 on the positive side and 0.5 cm-1 on the negative side, to obtain a hysteresis curve of the bending moment required for bending in each direction. The amount of hysteresis of the bending moment when the curvature is 0.1 cm-1 is defined as the bending hysteresis 2HB.

Similar to the bending rigidity B, Figure 12A shows the measurement results of bending hysteresis 2HB (gf· ^cm2 /cm) by the KES method at the longitudinal center and width center of the absorbent layer 10 of the napkin 1 of this embodiment, and the measurement results of bending hysteresis 2HB (gf· ^cm2 /cm) by the KES method at the longitudinal center and width center of the absorbent body of comparison product X.

12A, the bending hysteresis 2HB (gf· ^cm2 /cm) at the longitudinal center and width center of the absorbent layer 10 of the napkin 1 of this embodiment is 0.8204-0.9253 gf· ^cm2 /cm, which is less than 0.93 gf· ^cm2 /cm. In contrast, the bending hysteresis 2HB (gf· ^cm2 /cm) at the longitudinal center and width center of the absorbent core of comparative product X is 4.0183-4.8341 gf· ^cm2 /cm, which is clearly greater than 0.93 gf· ^cm2 /cm. From these results, the napkin 1 is more likely to return the absorbent layer 10 to its original shape when worn, even when the absorbent layer 10 is deformed by external forces such as the wearer's body shape or the wearer's movements, and is less likely to wrinkle when force is applied to the napkin 1, compared to the comparative product X. Furthermore, the discomfort and strange feeling caused to the wearer by the deformation of the absorbent layer 10 can be reduced, compared to the comparative product X.

It is preferable that the linearity LC (compression hardness) of the compression characteristics of the absorbent layer 10 of the napkin 1 at the center of the longitudinal direction and the center of the width direction is 0.6 or more by the KES method. The larger the value of the linearity LC (compression hardness) of the compression characteristics, the stiffer the compression is. By making the linearity LC (compression hardness) of the compression characteristics 0.6 or more, the deformation of the absorbent layer 10 can be reduced more than when the linearity LC (compression hardness) of the compression characteristics is less than 0.6. Therefore, even if force is applied to the napkin 1, the risk of wrinkles being formed on the skin side of the napkin 1 can be reduced. In addition, the discomfort caused by the deformation of the absorbent layer 10 when worn by the wearer can be reduced. In addition, the risk of excrement leaking from the absorbent layer 10 due to the deformation of the absorbent layer 10 can be reduced.

In addition, the compression resilience RC (compression recovery) of the absorbent layer 10 in the napkin 1 at the center of the longitudinal direction and the center of the width direction is preferably 38.0% or more. The closer the compression resilience RC (compression recovery) value is to 100%, the higher the recovery. Even if the absorbent layer 10 is deformed by the application of force to the napkin 1 in the worn state, by setting the compression resilience RC (compression recovery) of the absorbent layer 10 at the center of the longitudinal direction and the center of the width direction to 38.0% or more, the shape of the absorbent layer 10 can be easily restored to its original state compared to when the compression resilience RC (compression recovery) of the absorbent layer 10 at the center of the longitudinal direction and the center of the width direction is less than 38.0%, so that even if force is applied to the napkin 1, the risk of wrinkles being formed on the skin side of the napkin 1 can be reduced. In addition, the discomfort caused by the deformation of the absorbent layer 10 when worn can be reduced.

In addition, the compression work WC by the KES method at the longitudinal center and width center of the absorbent layer 10 in the napkin 1 is preferably 1.3 gf·cm/ ^cm2 or more. The larger the value of the compression work WC, the easier it is to compress. Therefore, by setting the compression work WC by the KES method at the longitudinal center and width center of the absorbent layer 10 to 1.3 gf·cm/ ^cm2 or more, the absorbent layer 10 is more easily compressed and wrinkles are less likely to form than when the compression work WC is less than 1.3 gf·cm/ ^cm2 . In addition, the shape of the absorbent layer 10 is more easily restored than when the compression work WC is less than 1.3 gf·cm/ ^cm2 , so the risk of wrinkles occurring on the skin side of the napkin 1 can be reduced. Furthermore, the discomfort caused by the deformation of the absorbent layer 10 when worn by the wearer can be reduced.

<Method of measuring compression resilience LC, compression resilience RC, and compression work WC>
The compression resilience LC (compression hardness) and the compression resilience RC (compression recovery) can be measured by a known method, for example, using an automated compression tester KES-FB3 AUTO-A manufactured by Kato Tech Co., Ltd.
First, the absorbent layer 10 (the skin side layer 2 and the non-skin side layer 3 overlapped) is removed from the napkin 1, and a portion measuring 50 mm x 50 mm is cut out as a sample from the longitudinal center and width center of the absorbent layer 10.
Each sample is compressed in a predetermined area between steel plates having a circular, flat terminal with an area of 200 mm ² at a compression speed of 50 sec/mm and a maximum compression load of 50 gf/cm ² to measure the compression characteristics of the sample.
The compression characteristics are also measured at the same speed during the recovery process, and the linearity LC of the compression characteristic curve obtained from the measurements, the compression recovery rate RC [%], and the compression work load WC [gf·cm/cm ² ] are calculated.

Figure 11B shows the results of measuring the compression characteristics using the KES method. Figure 11B shows the results of measuring the compression characteristics using the KES method for the absorbent layer 10 of the napkin 1 of this embodiment and the absorbent body (absorbent layer) of comparative product X, which is an existing sanitary napkin. Note that comparative product X is the same as the one whose bending characteristics were measured using the KES method described above.

As shown in FIG. 11B, the linearity LC of the compression characteristics at the longitudinal center and width center of the absorbent layer 10 of the napkin 1 of this embodiment is 0.609 to 0.653, which is 0.6 or more. In contrast, the linearity LC of the compression characteristics at the longitudinal center and width center of the absorbent body of the comparative product X is 0.365 to 0.757. In addition, the average value of the linearity LC of the compression characteristics at the longitudinal center and width center of the absorbent layer 10 of the napkin 1 of this embodiment is 0.632, while the linearity LC of the compression characteristics at the longitudinal center and width center of the absorbent body of the comparative product X is 0.575. From this result, the absorbent layer 10 of the napkin 1 can reduce deformation more than the absorbent body of the comparative product X. Therefore, the risk of wrinkles being formed on the skin side of the napkin 1 can be reduced more than the comparative product X even when force is applied to the napkin 1. In addition, it is possible to reduce the discomfort felt by the wearer due to deformation of the absorbent layer 10 when worn, and the absorbent layer 10 of napkin 1 can reduce leakage of excrement due to deformation of the absorbent layer 10 more than the absorbent body of comparative product X.

As for the compression resilience RC, as shown in FIG. 11B, the compression resilience RC at the longitudinal center and width center of the absorbent layer 10 of the napkin 1 of this embodiment is 38.80-40.18%, which is clearly greater than 38%. In contrast, the compression resilience RC at the longitudinal center and width center of the absorbent body of the comparative product X is 41.50-59.216%. In other words, the absorbent layer 10 of the napkin 1 of this embodiment has the same compression resilience RC characteristics as the comparative product X, making it easier to return the shape of the absorbent layer 10 to its original state and reducing the risk of wrinkles forming on the skin side of the napkin 1. In addition, the discomfort caused by deformation of the absorbent layer 10 when worn can be reduced while improving breathability, thereby improving comfort when worn.

11B, the compression work WC at the longitudinal center and width center of the absorbent layer 10 of the napkin 1 of this embodiment is 1.365 to 1.646 gf·cm/cm ² , which is 1.3 gf·cm/cm 2 or more. In contrast, the compression work WC at the longitudinal center and width center of the absorbent body of the comparative product X is 0.673 to 1.287 gf·cm/cm ² , which is less than 1.3 gf·cm/ ^{cm 2. From} this value of compression work WC, the absorbent layer 10 of the napkin 1 is more easily compressed than the comparative product X and has good recovery properties, so wrinkles are less likely to form on the skin side of the napkin 1 than on the skin side of the comparative product X. Furthermore, the napkin 1 is less likely to cause discomfort due to deformation of the absorbent layer 10 (absorbent body) than the comparative product X.

Furthermore, in an elongation test for measuring the magnitude of force required to elongate the absorbent layer 10 (skin-side layer 2 and non-skin-side layer 3 stacked together) to a predetermined length, it is preferable that the value obtained by dividing the value of the force magnitude in the 10th measurement of the elongation test of the absorbent layer 10 by the value of the force magnitude in the first measurement of the elongation test of the absorbent layer 10 is 50% or more. By dividing the value of the force magnitude in the 10th measurement of the elongation test by the value of the force magnitude in the first measurement being 50% or more, damage to the absorbent layer 10 can be reduced even when the absorbent layer 10 is worn, and a predetermined stress can be maintained even when the absorbent layer 10 is repeatedly subjected to force and elongated, compared to when the value of the force magnitude in the 10th measurement of the elongation test divided by the value of the force magnitude in the first measurement is less than 50%, so that the napkin 1 equipped with the absorbent layer 10 can easily follow the shape and movement of the wearer's body. In other words, a napkin 1 equipped with such an absorbent layer 10 can be made to be a napkin 1 in which the absorbent layer 10 is less likely to break when external force is applied to the absorbent layer 10 while it is being worn, and in which the absorbent layer 10 easily adapts to the shape and movements of the wearer's body.

<Measurement method for elongation test>
The elongation test can be performed by a cycle test using an autograph tensile tester, for example, model AG-1KNI, manufactured by Shimadzu Corporation. The specific measurement method is as follows.
First, the absorbent layer 10 (skin side layer 2 and non-skin side layer 3 overlapped) is taken out from the napkin 1 to be measured, and a sample is prepared. The cut-out sample is fixed to the chuck of the tester with the chuck distance set to 100 mm. The sample is then stretched in the longitudinal direction at a speed of 100 mm/min to 130% of the chuck distance of 100 mm, i.e., to a chuck distance of 130 mm, and then returned to the position of the chuck distance of 100 mm at a speed of 100 mm/min. The maximum value of the force magnitude (N) at this time is taken as the measurement result value of the first stretching test (the force magnitude value from the first measurement).
Next, the sample with the chuck distance of 100 mm is stretched in the longitudinal direction at a speed of 100 mm/min to 130% of the chuck distance of 100 mm, i.e., to a chuck distance of 130 mm, and then returned to the chuck distance of 100 mm at a speed of 100 mm/min. The maximum force magnitude (N) at this time is taken as the measurement result value of the second stretch test (the force magnitude value from the second measurement). The stretch test is repeated in the same manner to obtain the measurement result values of the third to tenth tests.
Then, a value is calculated by dividing the tenth measurement result value (the value of the magnitude of the force from the tenth measurement) by the first measurement result value (the value of the magnitude of the force from the first measurement).

Figure 13 shows the measurement results of the elongation test of the absorbent layer 10. Figure 13 shows the measurement results of the elongation test of the absorbent layer 10 of the napkin 1 of this embodiment and the absorbent body (absorbent layer) of the comparative product X, which is an existing sanitary napkin. Note that the comparative product X is the same as the one whose bending properties were measured using the KES method described above.

The measurement result (magnitude of force) of the absorbent layer 10 of the napkin 1 in the extension test is as shown in FIG. 13. The measurement result (magnitude of force) of the absorbent layer 10 of the napkin 1 in the 10th extension test is 15.270 N. The value obtained by dividing the force magnitude value (15.270 [N]) from the 10th measurement of the extension test by the force magnitude value (20.967 [N]) from the first measurement is 15.270 [N] / 20.967 [N] = 0.7283, which is clearly 50% or more. In contrast, in the comparative product X, the absorbent body broke in the second extension test, and the measurement result of the 10th extension test could not be obtained. In other words, it is 0 N. The absorbent layer 10 of the napkin 1 has a value greater than 0N even in the tenth measurement, which reduces damage or breakage of the absorbent layer 10 when an external force is applied while the napkin is being worn. Therefore, the absorbent layer 10 of the napkin 1 of this embodiment is less likely to break or break while the napkin is being worn than the absorbent body of the comparative product X. This also makes it easier for the absorbent layer 10 to adapt to the wearer's body and movements, and makes it easier for the wearer to feel comfortable when wearing the napkin, compared to when the value obtained by dividing the value of the magnitude of force from the tenth measurement of the elongation test by the value of the magnitude of force from the first measurement is less than 50%.

It is also preferable that the airflow resistance of the absorbent layer 10 (skin side layer 2 and non-skin side layer 3 stacked together) is 0.32 kpa·s/m or less. By making the airflow resistance of the absorbent layer 10 0.32 kpa·s/m or less, the breathability of the napkin 1 can be improved more than when the airflow resistance is greater than 0.32 kpa·s/m. This can reduce discomfort such as stuffiness felt by the wearer of the napkin 1.

The airflow resistance of the absorbent layer 10 can be measured by a known method. For example, the absorbent layer 10 is cut into a circular sample of a given size (e.g., 70 mm diameter x 70 mm diameter). Then, using a Kato Tech Co., Ltd. air permeability tester (KES-F8) or an equivalent air permeability tester, the standard air flow rate is set to 2 cm/s and the air permeability of the sample is measured. This measurement is performed multiple times (e.g., 5 times), and the average value can be used as the air permeability of the absorbent layer 10.

In the above embodiment, the fibers (latent shrink fibers) 2f constituting the skin side layer 2 and the fibers (latent shrink fibers) 3f constituting the non-skin side layer 3 have the same thickness (2.2 dtex), but this is not limited to this. The thickness (fiber diameter) of the fibers 2f in the skin side layer 2 and the thickness (fiber diameter) of the fibers 3f in the non-skin side layer 3 can be selected arbitrarily. For example, the maximum value of the fiber thickness of the skin side layer 2 may be larger than the maximum value of the fiber thickness of the non-skin side layer 3. In general nonwoven fabrics, the thicker the fibers are, the larger the gaps formed by the multiple fibers are likely to be. Therefore, by making the maximum value of the fiber thickness of the skin side layer 2 larger than the maximum value of the fiber thickness of the non-skin side layer 3, it becomes easier to draw excrement into the non-skin side layer 3 than into the skin side layer 2 by capillary action, and it becomes easier to diffuse excrement within the non-skin side layer 3. This reduces the risk of excrement coming into contact with the wearer's skin when worn, improving comfort during wear. In addition, generally, the thinner the fiber 2f, the denser the fiber structure becomes, making the fiber 2f less likely to move, and the fiber shape recovery when force is applied to the fiber 2f (skin side layer 2) is likely to decrease. In contrast, by making the fiber 2f in the skin side region Ru thicker than the fiber 2f in the non-skin side region Rd, the fiber structure in the skin side region Ru is less likely to become dense, making the fiber easier to move, and improving the recovery of the fiber 2f when force is applied to the fiber 2f. This reduces the risk of wrinkles and creases forming in the skin side region Ru compared to the non-skin side region Rd, making it easier to reduce wrinkles and creases occurring on the skin side of the napkin 1.

In the above embodiment, the absorbent layer 10 is formed by overlapping the skin-side layer 2, which is a nonwoven fabric sheet, and the non-skin-side layer 3, which is a nonwoven fabric sheet, in a state of being in contact with each other, but this is not limited to this. FIG. 14 is a diagram illustrating a napkin 100 of a modified embodiment of this embodiment. As in the napkin 100 shown in FIG. 14, the skin-side layer 2 and the non-skin-side layer 3, which are the absorbent layer 10, may be joined, and the absorbent layer 10 may be composed of one member. As in the napkin 100, the absorbent article may be composed of two members, the absorbent layer 10 and the back sheet 4. Note that, unlike the napkin 100, the side sheet 5 does not necessarily have to be provided. Furthermore, another member such as a sheet member may be provided between the absorbent layer 10 and the back sheet 4.

===Other embodiments===
The above-described embodiment is intended to facilitate understanding of the present invention, and is not intended to limit the present invention. The present invention can be modified or improved without departing from the spirit of the present invention, and it goes without saying that the present invention includes equivalents thereof.

1. Napkins (sanitary napkins, absorbent articles),
1w wing part,
2 Skin side layer (absorbent member),
2f latent crimp fiber (fiber),
3. Non-skin side layer,
3f latent crimp fiber (fiber),
4 Back sheet (outer layer),
5 side seats,
10 Absorption layer,
20 Compression section,
DH High density part, concave part,
DL low density part,
Ru skin side region,
Rm intermediate region;
Rd Non-skin side area

Claims (20)

In a deployed state, the device has a longitudinal direction, a width direction, and a thickness direction,
a skin side layer provided closest to the skin side in a central portion in the width direction;
a non-skin side layer provided on the non-skin side of the skin side layer;
a liquid-impermeable outer layer provided on the non-skin side of the non-skin side layer;
The skin side layer and the non-skin side layer each have a plurality of fibers including latently crimped fibers,
The absorbent article, characterized in that the plurality of fibers are not fused to each other in the skin side layer and the non-skin side layer. The absorbent article according to claim 1,
The non-skin side layer has a linear high density portion in which the density of the fibers is higher than that of the surrounding area. The absorbent article according to claim 1 or 2,
An absorbent article, comprising a recess that is recessed in the thickness direction on the skin side of the non-skin side layer. The absorbent article according to claim 1 or 2,
An absorbent article, characterized in that no adhesive is provided between the skin side layer and the non-skin side layer in the central portion in the width direction. The absorbent article according to claim 1 or 2,
The absorbent article is characterized in that the thickness of the skin side layer is greater than the thickness of the non-skin side layer. The absorbent article according to claim 1 or 2,
the skin side layer has voids formed by the plurality of fibers,
When the skin side layer is divided into three equal parts in the thickness direction, the region closest to the skin side is defined as the skin side region, the region closest to the skin side is defined as the non-skin side region, and the region between the skin side region and the non-skin side region is defined as an intermediate region,
The average narrowness of the non-skin side region in a narrowness evaluation test for quantitatively evaluating the narrowness of the gap is
An absorbent article characterized in that the narrowness is smaller than the average narrowness of the skin side region in the narrowness evaluation test. The absorbent article according to claim 1 or 2,
the skin side layer has voids formed by the plurality of fibers,
When the skin side layer is divided into three equal parts in the thickness direction, the region closest to the skin side is defined as the skin side region, the region closest to the skin side is defined as the non-skin side region, and the region between the skin side region and the non-skin side region is defined as an intermediate region,
The void ratio of the non-skin side region in a void ratio evaluation test for quantitatively evaluating the ratio of the voids in a predetermined region is
An absorbent article characterized in that the void ratio is smaller than that of the skin side region in the void ratio evaluation test. The absorbent article according to claim 1 or 2,
An absorbent article, characterized in that the hydrophilicity of the skin side layer is lower than the hydrophilicity of the non-skin side layer. The absorbent article according to claim 1 or 2,
the skin side layer has voids formed by the plurality of fibers,
When the skin side layer is divided into three equal parts in the thickness direction, the region closest to the skin side is defined as an upper region, the region closest to the non-skin side is defined as a lower region, and the region between the skin side region and the non-skin side region is defined as an intermediate region,
At least a portion of the fibers in the non-skin side region have a higher hydrophilicity than the fibers in the skin side region;
An absorbent article, characterized in that a portion of the fibers in the non-skin side region is exposed to the skin side surface of the skin side region. The absorbent article according to claim 1 or 2,
An absorbent article, characterized in that the maximum fiber thickness of the skin side layer is greater than the maximum fiber thickness of the non-skin side layer. The absorbent article according to claim 1 or 2,
The absorbent article is characterized in that the latent crimp fibers of the skin side layer and the non-skin side layer are fibers made of a resin of a single composition. The absorbent article according to claim 1 or 2,
An absorbent article, characterized in that the latent crimp fibers of the skin side layer and the non-skin side layer are each fibers made of polyethylene terephthalate. The absorbent article according to claim 1 or 2,
An absorbent article characterized in that, when the skin side layer and the non-skin side layer are stacked together, the bending rigidity B of the central portion in the longitudinal direction and the central portion in the width direction of the skin side layer and the non-skin side layer, as measured by the KES method, is 1.2 gf· ^cm2 /cm or less. The absorbent article according to claim 1 or 2,
An absorbent article characterized in that, when the skin side layer and the non-skin side layer are overlapped, the bending hysteresis 2HB of the skin side layer and the non-skin side layer in the longitudinal center and the width direction center is 0.93 gf· ^cm2 /cm or less as measured by the KES method. The absorbent article according to claim 1 or 2,
An absorbent article characterized in that, when the skin side layer and the non-skin side layer are stacked together, the linearity LC of the compression characteristics in the longitudinal center and the width center of the skin side layer and the non-skin side layer, as measured by the KES method, is 0.6 or more. The absorbent article according to claim 1 or 2,
An absorbent article characterized in that, when the skin side layer and the non-skin side layer are stacked together, the compression resilience RC of the longitudinal center portion and the width center portion of the skin side layer and the non-skin side layer, as measured by the KES method, is 38.0% or more. The absorbent article according to claim 1 or 2,
an absorbent article characterized in that, when the skin side layer and the non-skin side layer are overlapped, a compression work WC of the center portion in the longitudinal direction and the center portion in the width direction of the skin side layer and the non-skin side layer, as measured by the KES method, is 1.3 gf cm/ ^cm2 or more. The absorbent article according to claim 1 or 2,
When viewed in the thickness direction, a central portion in the longitudinal direction and a central portion in the width direction of the absorbent article are defined as a predetermined region,
The weight of the predetermined area before absorbing distilled water is defined as a pre-absorption weight,
The weight of the predetermined area after immersing the predetermined area in distilled water for 60 seconds and then lifting it out of the distilled water and hanging it for 90 seconds is defined as the post-absorption weight.
When the value obtained by subtracting the weight before absorption from the weight after absorption is defined as the absorption weight of the distilled water,
An absorbent article, characterized in that a value obtained by dividing the absorption weight by the weight before absorption is 5 or more. The absorbent article according to claim 1 or 2,
In an elongation test for measuring the magnitude of a force required to elongate the longitudinal length of the skin side layer and the non-skin side layer in a state in which the skin side layer and the non-skin side layer are stacked together until the longitudinal length of the skin side layer and the non-skin side layer becomes 1.3 times the longitudinal length of the skin side layer and the non-skin side layer,
An absorbent article characterized in that the value of the force magnitude obtained by measuring the tenth measurement of the elongation test of the skin side layer and the non-skin side layer divided by the value of the force magnitude obtained by measuring the first measurement of the elongation test of the skin side layer and the non-skin side layer is 50% or more. The absorbent article according to claim 1 or 2,
An absorbent article, characterized in that an air flow resistance value in a state in which the skin side layer and the non-skin side layer are overlapped is 0.32 kpa·s/m or less.

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