KR102557595B1 - absorbent article - Google Patents

Abstract

In the absorbent article 1, it is possible to improve the absorbent performance while improving the tactile feel of the topsheet 2. In an absorbent article (1), a topsheet (2) comprises a first fibrous layer (2a) containing water-retaining fibers, and adjacent to the non-skin side of the first fibrous layer (2a), containing hydrophobic fibers and water-retaining fibers. A second fiber layer 2b is provided. The skin-side surface of the first fiber layer 2a constitutes the skin-side surface of the topsheet 2. The ratio of water-retaining fibers in the fibers constituting the first fibrous layer 2a is greater than the ratio of water-retaining fibers in the fibers constituting the second fibrous layer 2b. The average fiber length of the water-retaining fibers of the second fiber layer 2b is shorter than the average fiber length of the water-retaining fibers of the first fiber layer 2a.

Description

absorbent article

The present invention relates to an absorbent article.

As a surface sheet of an absorbent article, a sheet containing water-retaining fibers that absorb and retain moisture, such as cotton fibers, is known. For example, Patent Literature 1 discloses a fiber sheet containing cotton fibers used as a topsheet. This fiber sheet includes a cotton fiber layer and a synthetic fiber nonwoven fabric, and the cotton fiber layer is formed in a state where a portion of the cotton fiber layer is drawn into the nonwoven fabric.

In general, since water-retaining fibers such as cotton fibers have a good feel, they are suitably used for underwear and the like in contact with the skin. However, since cotton fibers have high water retention properties, when a sheet containing cotton fibers is used as a topsheet of an absorbent article, the topsheet absorbs and retains liquid excretion (liquid excrement) excreted from the wearer, making it damp. There is a possibility of maintaining the state. Then, since the wearer continues to contact the wet and damp topsheet, there is a fear of feeling uncomfortable. That is, when a sheet containing cotton fibers is used for the topsheet, there is a problem of low dryness.

According to the description in Patent Document 1, the fiber sheet containing cotton fibers disclosed in Patent Document 1 has the following characteristics. In the fiber sheet, since the cotton fiber layer is drawn inside the nonwoven fabric in the thickness direction, the amount of fibers gradually increases from the cotton fiber layer to the central portion in the thickness direction of the fiber sheet, that is, the distance between fibers gradually decreases. As a result, the capillary force gradually increases from the cotton fiber layer toward the central portion in the thickness direction of the fiber sheet, and the drawing ability of liquid from the cotton fiber layer to the inside of the sheet increases. Therefore, the dryness of the surface of the fiber sheet can be improved.

Patent Document 1: Japanese Unexamined Patent Publication No. 2004-324038

However, the fiber sheet containing cotton fibers of Patent Document 1 has the following problems. The synthetic fiber layer located on the opposite side to the cotton fiber layer with the central portion in the thickness direction of the fiber sheet interposed therebetween is a layer of only synthetic fibers. Therefore, the amount of fibers gradually decreases, that is, the distance between fibers gradually increases from the central portion in the thickness direction of the fiber sheet to the layer of synthetic fibers. As a result, the capillary force gradually decreases from the central portion in the thickness direction of the fiber sheet to the layer of synthetic fibers. In this case, the fiber sheet can draw the liquid absorbed from the cotton fiber layer side up to the central portion in the thickness direction of the fiber sheet, but it becomes difficult to transfer the liquid to the synthetic fiber layer side. Therefore, when the fiber sheet is used as the topsheet of an absorbent article, the topsheet can draw liquid excretion excreted from the wearer from the cotton fiber layer to the central portion in the thickness direction, but from the central portion in the thickness direction to the synthetic fiber layer. difficult to fulfill That is, it becomes difficult for liquid excretion to migrate from the topsheet to the absorbent body, and there is a risk that the absorbent article's absorbent performance is lowered, for example, the absorbent rate is lowered or the absorbent amount is lowered.

An object of the present invention is to provide an absorbent article capable of improving absorbent performance while improving the tactile feel of the topsheet.

The absorbent article of the present invention is as follows. (1) An absorbent article comprising a topsheet, a backsheet, and an absorbent body positioned between the topsheet and the backsheet, wherein the topsheet includes: a first fiber layer containing water-retaining fibers; a second fibrous layer adjacent to the non-skin side and containing hydrophobic fibers and water-retaining fibers; the skin-side surface of the first fibrous layer constitutes the skin-side surface of the topsheet; The non-skin side surface constitutes the non-skin side surface of the topsheet, and the ratio of the water-retaining fibers in the fibers constituting the first fiber layer is greater than the ratio of the water-retaining fibers in the fibers constituting the second fiber layer. and the average fiber length of the water-retaining fibers of the second fiber layer is shorter than the average fiber length of the water-retaining fibers of the first fiber layer.

In this absorbent article, since the ratio of water-retaining fibers in the first fiber layer located on the skin side of the topsheet is relatively high, the topsheet can feel good to the touch. In addition, since the average fiber length of the water-retaining fibers included in the first fiber layer is relatively long, it is possible to suppress a situation where the average fiber length is too short and the fibers are not entangled with each other and fluffing occurs, thereby improving the feel of the topsheet. decline can be prevented.

At this time, since the average fiber length of the water-retaining fibers included in the second fiber layer is shorter than the average fiber length of the water-retaining fibers included in the first fiber layer, the fibers constituting the second fiber layer can be brought closer to each other. Therefore, since the average distance between fibers of the second fiber layer can be shortened compared to the average distance between fibers of the first fiber layer, capillary action can be more strongly generated in the second fiber layer, and the skin-side surface of the first fiber layer The liquid excretion excreted in can be quickly drawn into the second fibrous layer. And, the liquid excretion entrained in the second fibrous layer can be quickly transferred to the absorber through the second fibrous layer by means of the hydrophobic fibers.

At this time, in the first fibrous layer, the liquid excrement can be drawn into the second fibrous layer while spreading it widely in the plane direction by water-retaining fibers having a relatively long average fiber length. As a result, since the liquid excretion spread widely in the plane direction in the topsheet can be absorbed in a wide area in the plane direction in the absorber, the absorption performance can be improved.

This makes it possible to improve the water absorption performance while improving the touch of the topsheet.

The absorbent article of the present invention comprises (2) a topsheet, a backsheet, and an absorbent body positioned between the topsheet and the backsheet, wherein the topsheet comprises a first water-retaining fiber. a fibrous layer and a second fibrous layer adjacent to the non-skin side of the first fibrous layer and containing hydrophobic fibers and water-retaining fibers, wherein the skin-side surface of the first fibrous layer constitutes the skin-side surface of the topsheet. The non-skin side surface of the second fiber layer constitutes the non-skin side surface of the topsheet, and the ratio of the water-retaining fibers in the fibers constituting the first fiber layer is the ratio of the fibers constituting the second fiber layer. The absorbent article may be an absorbent article in which the ratio of the water-retaining fibers in the water-retaining fibers is higher than that of the first fiber layer and the fiber density of the first fiber layer is smaller than that of the second fiber layer. Here, the fiber density is the density of the number of fibers.

In this absorbent article, since the ratio of water-retaining fibers in the first fiber layer located on the skin side of the topsheet is relatively high, the topsheet can feel good to the touch.

At that time, since the fiber density of the second fiber layer is higher than that of the first fiber layer, the fibers constituting the second fiber layer can be brought closer to each other. Therefore, since the average distance between fibers of the second fiber layer can be shortened compared to the average distance between fibers of the first fiber layer, capillary action can be more strongly generated in the second fiber layer, and the skin-side surface of the first fiber layer The liquid excretion excreted in can be quickly drawn into the second fibrous layer. And, the liquid excretion entrained in the second fibrous layer can be quickly transferred to the absorber through the second fibrous layer by means of the hydrophobic fibers.

At this time, in the first fibrous layer, the liquid excrement can be drawn into the second fibrous layer while being spread widely in the plane direction by the water-retaining fibers. As a result, since the liquid excretion spread widely in the plane direction in the topsheet can be absorbed in a wide area in the plane direction in the absorber, the absorption performance can be improved.

This makes it possible to improve the water absorption performance while improving the touch of the topsheet.

The absorbent article of the present invention may be the absorbent article described in (2) above, wherein (3) an auxiliary sheet having a higher fiber density than that of the second fiber layer is provided between the topsheet and the absorber. .

Since this absorbent article further includes an auxiliary sheet having a fiber density higher than that of the second fiber layer, liquid excrement entrained in the second fiber layer can be stably transferred to the auxiliary sheet by capillarity. Thereby, liquid excretion can be more stably transferred from the topsheet to the absorber through the auxiliary sheet, and thus the topsheet can improve the absorbent performance while improving the tactile feel.

(4) The absorbent article according to any one of (1) to (3) above, wherein the hydrophobic fibers included in the second fiber layer include heat-sealable fibers heat-sealed to each other. It may be an article.

In this absorbent article, the shape of the second fiber layer can be stably maintained by heat-sealable fibers being thermally fused to each other in the second fiber layer. Therefore, even if the average fiber length of the water-retaining fibers included in the second fiber layer is relatively short, the water-retaining fibers can be stably maintained so as not to be concentrated between the hydrophobic fibers. As a result, the liquid excrement entrained in the second fiber layer can be stably transferred to the absorber without being concentrated, and the absorption performance can be improved.

The absorbent article of the present invention may be (5) the absorbent article described in (4) above, wherein at least a part of the heat-sealable fibers of the second fiber layer are exposed on the skin-side surface of the first fiber layer.

In this absorbent article, part of the heat-fusible fibers of the second fiber layer exist in the first fiber layer so as to be exposed on the surface of the first fiber layer, so that the water-retaining fibers of the first fiber layer can be stably maintained between the heat-fusible fibers. there is. Thereby, even if the average distance between the fibers of the first fiber layer is relatively long and the strength of the first fiber layer is relatively weak, it is possible to suppress settling. Further, by holding the water-retaining fibers of the first fiber layer between the heat-fusible fibers, it is also possible to suppress fuzzing. In this way, the feel of the first fiber layer can be improved. In addition, since a part of the heat-fusible fibers that do not have water retention in the second fiber layer exist in the first fiber layer, the transfer of liquid excretion from the first fiber layer to the second fiber layer through the heat-fusible fibers can be promoted. there is. Thereby, liquid excretion can be stably transferred to the absorber.

The absorbent article of the present invention has (6) a crimped portion in which the topsheet and the absorbent body are compressed in the thickness direction of the absorbent article, and at least a portion of the heat-sealable fibers of the second fiber layer are inside the crimped portion. The absorbent article described in (4) or (5) above, which is exposed on the surface, may be used.

In this absorbent article, part of the heat-fusible fibers of the second fiber layer exist in the first fiber layer so as to be exposed on the inner surface of the crimping part, so that the water-retaining fibers of the first fiber layer in the crimping part are stably interposed between the heat-sealable fibers. can be maintained as As a result, even if the strength of the first fiber layer in the crimping part is relatively weak, it is possible to suppress sinking or fluffing, and the first fiber layer in the crimping part can have a better feel. In addition, since a part of the heat-fusible fibers having no water retention in the second fiber layer is present in the first fiber layer in the compression section, liquid excretion flows from the first fiber layer in the compression section to the second fiber layer through the heat-fusible fibers. can facilitate the implementation of Thereby, liquid excretion can be more stably transferred to the absorber.

In the absorbent article of the present invention, (7) the crimping portion includes a low-density portion having a shallow depth in the thickness direction of the absorbent article and a high-density portion having a depth in the thickness direction of the absorbent article; The absorbent article described in (6) above may be used in which at least a part of the fusible fibers is exposed on the surface of the low-density portion.

In this absorbent article, part of the heat-fusible fibers of the second fiber layer exist in the first fiber layer so as to be exposed on the surface of the low-density portion, thereby stably holding the water-retaining fibers of the first fiber layer in the low-density portion between the heat-fusible fibers. can As a result, even if the strength of the first fiber layer in the low-density portion is relatively weak, it is possible to suppress sinking and fluffing, and the touch of the first fiber layer in the low-density portion can be improved. In addition, since a part of the heat-fusible fibers having no water retention in the second fiber layer exist in the first fiber layer in the low-density part, liquid excretion passes from the first fiber layer in the low-density part to the second fiber layer through the heat-fusible fiber. can facilitate the implementation of As a result, liquid excretion can finally be more stably transferred to the absorber.

In the absorbent article of the present invention, (8) the topsheet comprises: a plurality of convex portions extending along the longitudinal direction of the absorbent article and positioned at intervals in the width direction of the absorbent article; It extends along and has a plurality of concave portions located between adjacent convex portions, and in the topsheet, the fiber density of the top of the convex portion is S1, the fiber density of the bottom portion of the concave portion is S2, and the convex portion is The absorbent article according to any one of (1) to (7) above, wherein S1<S3<S2, when the fiber density in the region between the top of the portion and the bottom of the concave portion is S3, may be used.

In the absorbent article according to claim 8, in the topsheet, from the top of the convex portion having a low fiber density through the region between the top of the convex portion having a medium fiber density and the bottom of the concave portion, the concave portion having a high fiber density Capillarity acts towards the bottom. Therefore, liquid excretion excreted on the most skin-side surface of the topsheet (at or near the top of the convex portion) can be more easily drawn into the bottom of the concave portion located near the non-skin-side surface of the topsheet. can Thereby, liquid excretion can be more stably transferred from the skin-side surface of the topsheet to the absorber through the non-skin-side surface of the topsheet. In addition, it is possible to make it difficult to rewet back liquid excrement once absorbed by the fiber density gradient. In addition, since the fiber density of the convex portion is low, the wearer can feel softness. Therefore, it is possible to improve the water absorption performance while improving the tactile feel of the topsheet.

In the absorbent article of the present invention, (9) the topsheet has a plurality of depressions in which the first fiber layer and the second fiber layer are compressed in the thickness direction of the absorbent article in each of the plurality of depressions. The absorbent article described in (8) above may be used.

In this absorbent article, in the plurality of depressions, the first fiber layer and the second fiber layer are pressed and fixed to each other, so that the water-retaining fibers of the first fiber layer are compressed. Accordingly, it is possible to suppress the occurrence of fluffing of the water-retaining fibers and to keep the topsheet good in touch.

In the absorbent article of the present invention, (10) the hydrophobic fibers of the second fibrous layer have an average fiber length greater than the average fiber length of the water-retaining fibers of the first fibrous layer and the second fibrous layer; ) may be the absorbent article according to any one of the above.

In this absorbent article, the average fiber length of the hydrophobic fibers of the second fibrous layer is longer than the average fiber length of the water-retaining fibers of the first fibrous layer and the second fibrous layer. Therefore, at least a part of the hydrophobic fibers of the second fiber layer can reach the inside of the first fiber layer. Thereby, liquid excretion from the first fiber layer can be more easily transferred to the second fiber layer, and liquid excretion that has migrated to the second fiber layer can be more easily transferred to the absorber.

In the absorbent article of the present invention, (11) the water-retaining fibers included in the topsheet are cellulose fibers, the absorbent body includes cellulose fibers (excluding pulp fibers), and the cellulose fibers included in the topsheet A part of the system fibers may be the absorbent article according to any one of (1) to (10) above, which is in contact with the cellulosic fibers included in the absorber.

In this absorbent article, cellulosic fibers having high liquid diffusivity communicate from the first fibrous layer of the topsheet to the absorbent body through the second fibrous layer. Therefore, liquid excretion can be diffused directly from the topsheet to the absorber by utilizing the liquid diffusion of the liquid excretion by the cellulosic fibers. Thereby, absorption performance can be improved.

In the absorbent article of the present invention, (12) the fibers constituting the topsheet are oriented in the longitudinal direction of the topsheet at both ends in the width direction of the topsheet rather than at the central portion in the width direction of the topsheet. , The absorbent article according to any one of (1) to (11) above may be used.

In this absorbent article, since the fiber orientation of the topsheet is random in the central portion, liquid excretion can be spread over concentric circles without gaps, and the fiber orientation is oriented in the longitudinal direction at both ends, so both ends The liquid excretion that has reached can be spread in the longitudinal direction. That is, the absorbent article can be used as a whole, and the absorbent performance can be improved. In addition, at both ends of the topsheet, since the number of fibers exposed from the edge is reduced, friction against the skin is reduced, and deterioration in tactile sensation can be suppressed.

The absorbent article of the present invention (13) may be the absorbent article according to any one of (1) to (12) above, wherein the water-retaining fibers included in the topsheet are cotton.

In this absorbent article, since the water-retaining fiber is cotton, it is possible to further maintain or improve the water absorption performance while improving the touch of the topsheet.

(14) The absorbent article of the present invention further comprises an auxiliary sheet positioned between the topsheet and the absorber, wherein the topsheet has a dimension smaller than the width direction of the auxiliary sheet; The absorbent article according to any one of (1) to (13) above may be used.

When the edge of the topsheet containing many water-retaining fibers is rubbed, the water-retaining fibers are easily released from the edge and fall off. Therefore, in this absorbent article, the auxiliary sheet has a larger dimension in the width direction than that of the topsheet containing many water-retaining fibers. That is, in plan view, a pair of extensions are formed outside of both end edges in the width direction of the topsheet in the auxiliary sheet. Therefore, the force received by the absorbent article from the thighs of the wearer can be received by the pair of extensions at both ends in the width direction of the auxiliary sheet, and friction between the opposite ends in the width direction of the topsheet and the thighs can be prevented. . As a result, it is possible to prevent friction between both end edges of the topsheet in the width direction and to prevent the water-retaining fibers from unraveling and falling off from both end edges in the width direction of the topsheet, and to suppress deterioration in tactile feel.

ADVANTAGE OF THE INVENTION According to this invention, it is possible to provide an absorbent article capable of improving absorbent performance while improving the tactile feel of the topsheet.

1 is a plan view showing a configuration example of an absorbent article according to an embodiment.
FIG. 2 is a cross-sectional view taken along line II-II of FIG. 1 .
Fig. 3 is a plan view and a sectional view showing a configuration example of a topsheet according to an embodiment.
Fig. 4 is a schematic diagram showing a configuration example of an absorbent article manufacturing apparatus according to an embodiment.
Fig. 5 is a cross-sectional view explaining a manufacturing method of an absorbent article according to an embodiment.

The absorbent article according to the embodiment will be described by taking a sanitary napkin as an example. However, the types and uses of the absorbent article of the present invention are not limited to those examples, and can be applied to other absorbent articles as long as they do not deviate from the scope of the subject matter of the present invention. Other absorbent articles include, for example, panty liners, light incontinence pads, and disposable diapers.

(First Embodiment)

1 and 2 are diagrams showing structural examples of the sanitary napkin 1 according to the embodiment. Fig. 1 is a plan view showing the unfolded state of the sanitary napkin 1, Fig. 2(a) is a cross-sectional view taken along line II-II in Fig. 1, and Fig. 2(b) is Fig. 2(a) ) is a partially enlarged cross-section of The sanitary napkin 1 of this embodiment has a longitudinal direction (L), a width direction (W), and a thickness direction (T) that are orthogonal to each other. In the sanitary napkin 1 drawn in FIG. 1, the upper and lower sides in the drawing are the front and rear sides in the longitudinal direction L, respectively, and the left and right sides are the left and right sides in the width direction W, respectively. The near side and the far side are respectively regarded as the upper side and the lower side in the thickness direction T. The sanitary napkin 1 has a longitudinal center line C L (imaginary line) passing through the center in the width direction W and extending in the longitudinal direction _L , and passing through the center in the longitudinal direction L to form a width It has a width direction centerline C _W (imaginary line) extending in the direction W. The directions and sides toward the longitudinal centerline C _L are inward and inward, respectively, in the width direction W, and the directions and sides away from each other are set as outward and outward in the width direction W, respectively. On the other hand, directions and sides toward the widthwise centerline _CW are inward and inward, respectively, and directions away from each other are made outward and outward in the longitudinal direction L, respectively. Viewing the sanitary napkin 1 placed on a plane including the longitudinal direction (L) and the width direction (W) from the upper side in the thickness direction (T) is called "planar view", and the shape grasped in planar view is "planar It's called "shape." An arbitrary direction in a plane including the longitudinal direction L and the width direction W is referred to as a "planar direction". When the wearer puts on the sanitary napkin 1, the side closer to and farther from the wearer's skin surface in the thickness direction T is referred to as "skin side" and "non-skin side". These definitions are commonly used also for each material of the sanitary napkin 1.

In this embodiment, the sanitary napkin 1 (excluding the wings) has a substantially rectangular shape that is long in the longitudinal direction L and short in the width direction W in plan view, and has both ends in the longitudinal direction L. The edge has an approximately semicircular shape. However, the shape is not particularly limited as long as it is long in the longitudinal direction (L) and short in the width direction (W), and examples thereof include rounded rectangles, ovals, hourglasses, or shapes similar thereto. The sanitary napkin 1 has a wing portion 9 extending outward in the width direction W from a substantially rectangular portion, and the wing portion 9 has a substantially trapezoidal shape. However, the shape of the wing part 9 may be semicircular or semielliptical, for example.

In the present embodiment, the sanitary napkin 1 comprises a topsheet 2 constituting the skin-side surface of the sanitary napkin 1 and a non-skin-side surface of the sanitary napkin 1. A back sheet (3) and an absorber (4) disposed between the top sheet (2) and the back sheet (3) are provided. In this embodiment, the sanitary napkin 1 further includes an auxiliary sheet 5 and a pair of side sheets 6, 6. The auxiliary sheet 5 is arranged so as to overlap the non-skin side of the topsheet 2 . Each of the pair of side sheets 6, 6 is bonded to each of both ends in the width direction W on the non-skin side of the auxiliary sheet 5 so that the inner end in the width direction W overlaps. , and extends outward in the width direction W. Therefore, in this embodiment, the absorber 4 is positioned between the top sheet 2, the auxiliary sheet 5, and the pair of side sheets 6, 6 and the back sheet 3. However, an exterior sheet may be provided on the non-skin side of the back sheet 3.

The topsheet 2 is a liquid-permeable sheet, and includes a first fibrous layer 2a and a second fibrous layer 2b. The skin-side surface of the first fiber layer 2a constitutes the skin-side surface of the topsheet 2. The second fibrous layer 2b is adjacent to the non-skin side of the first fibrous layer 2a. In this embodiment, the non-skin side surface of the second fiber layer 2b constitutes the non-skin side surface of the topsheet 2, so the topsheet 2 has a two-layer structure. However, the second fibrous layer 2b may contain one or more fibrous layers on the non-skin side, and therefore the topsheet 2 may have a three-layer or multi-layer structure as a whole.

The first fibrous layer 2a contains water-retaining fibers.

The water-retaining fiber is not particularly limited as long as it has a property of absorbing and retaining moisture (water-retaining property). Examples of water-retaining fibers include cellulosic fibers. The cellulosic fiber is not particularly limited as long as it is a fiber containing cellulose, and examples thereof include natural cellulose fiber, regenerated cellulose fiber, purified cellulose fiber, and semi-synthetic cellulose fiber. Natural cellulose fibers include plant fibers such as seed hair fibers (eg cotton), bast fibers (eg hemp), leaf vein fibers (eg abaca hemp), and fruit fibers (eg palm). Examples of the cotton include Hirsutum cotton (eg, Upland cotton), Barbadense cotton, Arboreum cotton, and Herbaceum cotton. Moreover, as cotton, organic cotton and pre-organic cotton (trademark) may be sufficient. However, organic cotton means cotton certified by GOTS (Global Organic Textile Standard). Regenerated cellulose fibers include fibers such as rayon, for example, viscose rayon obtained from viscose, polynosic and modal, copper ammonia rayon obtained from a copper ammonia salt solution of cellulose (also referred to as “cufra”), and the like. As purified cellulose fiber, lyocell, specifically, pulp, is dissolved in an aqueous solution of N-methylmorpholine N-oxide to make a spinning dope (doping), and extruded in a dilute solution of N-methylmorpholine N-oxide to obtain What was made of fiber is mentioned. Purified cellulose is commercially available, for example, as Tencel (trademark). Semisynthetic cellulose fibers include fibers such as semisynthetic cellulose such as acetate fibers such as triacetate and diacetate. Among them, from the viewpoints of water retention and touch, natural cellulose fibers are preferred, cotton is more preferred, and Hirsutum cotton is still more preferred. In this embodiment, the water-retaining fiber is Hirsutum cotton (hereinafter, simply referred to as "cotton").

The second fibrous layer 2b contains hydrophobic fibers and water-retaining fibers.

The hydrophobic fiber is not particularly limited as long as it is a fiber having hydrophobicity. Examples of hydrophobic fibers include thermoplastic resin fibers. The thermoplastic resin fiber is not particularly limited as long as it is a fiber containing a thermoplastic resin. Examples of the thermoplastic resin include olefin resins such as polyethylene (PE), polypropylene (PP), and ethylene-vinyl acetate copolymer (EVA), and polyesters such as polyethylene terephthalate (PET) and polylactic acid (PLA). Known resins, such as resin and polyamide-type resins, such as 6-nylon, are mentioned, These resin may be used independently, and may use two or more types of resin together. In addition, the structure of the fibers made of these thermoplastic resins is not particularly limited, and examples thereof include composite fibers such as core-sheath type fibers, side-by-side types of fibers, and island/sea type fibers; hollow type fibers; irregular cross-section fibers such as flat, Y-shaped, and C-shaped fibers; stereocrimp fibers of latent crimp or current crimp; split fibers that are split by physical loads such as water flow, heat, and embossing; and the like. Fibers having such a structure may be used alone or two or more types of fibers may be used in combination. In this embodiment, the hydrophobic fiber is a PET/PE core-sheath type composite fiber. The water-retaining fibers are the same as the water-retaining fibers of the first fibrous layer 2a. In addition, "hydrophobicity" refers to a property that is difficult to mix with water or difficult to retain moisture. say

In the first fibrous layer 2a and the second fibrous layer 2b, the ratio of water-retaining fibers in the fibers constituting the first fibrous layer 2a is greater than the ratio of water-retaining fibers in the fibers constituting the second fibrous layer 2b. Thereby, at least the topsheet 2 can have a good feel. Further, in the first fiber layer 2a and the second fiber layer 2b, the average fiber length of the water-retaining fibers of the second fiber layer 2b is shorter than the average fiber length of the water-retaining fibers of the first fiber layer 2a. As a result, the fibers constituting at least the second fibrous layer 2b are brought closer to each other, that is, the distance between the fibers is shortened, so that the capillary action is more strongly generated and liquid excrement can be drawn in more strongly. Specifically, it is as showing below, for example.

The ratio of water-retaining fibers in the fibers constituting the first fiber layer 2a is preferably 70 to 100% by mass, more preferably 80 to 100% by mass, and preferably 90 to 100% by mass, from the viewpoint of enhancing the feel of the topsheet 2. 100% by mass is more preferred. By setting it to 70% by mass or more, it becomes easy for the wearer to recognize the first fiber layer 2a as a water-retaining fiber, so that a good feeling can be ensured. Among the fibers constituting the first fiber layer 2a, fibers other than water-retaining fibers are not particularly limited as long as they can form a liquid-permeable layer, and examples thereof include thermoplastic resin fibers. In this embodiment, the ratio of water-retaining fibers is 100% by mass.

The fineness of the water-retaining fibers of the first fiber layer 2a is not particularly limited, and examples thereof include 0.8 to 15 dtex. The fiber length of the water-retaining fibers of the first fiber layer 2a is, for example, 10 to 80 mm. In the case of less than 10 mm, the fiber length is too short, making it difficult to entangle the fibers, and there is a risk that sufficient strength may not be obtained. When the length exceeds 80 mm, several strands of such fibers extend in the width direction (W), and there is a possibility that the fibers extend from the edge of the wearer's thigh to the edge of the other thigh. In that case, water-retaining fibers Liquid excretion adhering to the central portion in the width direction W of the sanitary napkin 1 is diffused to both thighs due to the liquid diffusion effect, which may cause discomfort to the wearer. The fiber length is preferably 15 to 60 mm, and more preferably 20 to 40 mm. Correspondingly, the average fiber length of the water-retaining fibers of the first fiber layer 2a is, for example, 15 to 50 mm, preferably 20 to 45 mm, and more preferably 25 to 40 mm.

Further, the latitude, fiber length, and average fiber length of the fibers other than the water-retaining fibers in the first fiber layer 2a are similar to those of the water-retaining fibers (0.5 to 2 times greater) from the viewpoint of not adversely affecting the feel of the water-retaining fibers. range) is preferred. However, in this embodiment, fibers other than water-retaining fibers are not used.

The ratio of water-retaining fibers in the fibers constituting the second fibrous layer 2b is not particularly limited as long as it is smaller than the ratio of water-retaining fibers in the first fibrous layer 2a. As a ratio of water-retaining fiber, 50-90 mass % is mentioned, for example. If it is less than 50% by mass, there is a possibility that the touch in a state where pressure is applied in the thickness direction is reduced. When it exceeds 90% by mass, there is a fear that the effect of preventing fuzzing by hydrophobic fibers may decrease. The ratio of water-retaining fibers is preferably 60 to 85% by mass, and more preferably 70 to 80% by mass. Correspondingly, the ratio of hydrophobic fibers in the second fiber layer 2b is, for example, 10 to 50% by mass, preferably 15 to 40% by mass, and more preferably 20 to 30% by mass. Further, the second fiber layer 2b may contain third fibers in addition to water-retaining fibers and hydrophobic fibers.

The fineness of the water-retaining fibers of the second fiber layer 2b is not particularly limited, and examples thereof include 0.8 to 15 dtex. The fiber length of the water-retaining fibers of the second fiber layer 2b is not particularly limited as long as the average fiber length is shorter than the average fiber length of the water-retaining fibers of the first fiber layer 2a, and examples thereof include 3 to 40 mm. In the case of less than 3 mm, the fiber length is too short, making it difficult to entangle the fibers, and sufficient strength cannot be obtained. When it exceeds 40 mm, the dynamic freedom of the fibers in the web state during the manufacture of the second fibrous layer 2b is low, and water-retaining fibers cannot enter the gaps between the hydrophobic fibers, and as a result, the second fibrous layer 2b It becomes difficult to shorten the distance between fibers in , and furthermore, it becomes difficult to increase the fiber density. The fiber length of the water-retaining fibers of the second fiber layer 2b is preferably 5 to 35 mm, more preferably 10 to 35 mm. Correspondingly, the average fiber length of the water-retaining fibers of the second fiber layer 2b is, for example, 5 to 30 mm, preferably 10 to 25 mm, and more preferably 15 to 20 mm.

In addition, water-retaining fibers having a fiber length within the above range, and mixed water-retaining fibers obtained by mixing at least two types of water-retaining fibers having a long fiber length and water-retaining fibers having a short fiber length may be used. As an example, a water-retaining fiber with a long fiber length is, for example, 15 to 40 mm (preferably 20 to 35 mm), and a water-retaining fiber with a short fiber length is, for example, 3 to 25 mm (preferably 5 to 35 mm). 20 mm) of fiber length. In this case, the distance between the fibers of the second fiber layer 2b can be increased with the water-retaining fibers having a short fiber length, while the water-retaining properties and feel of the second fiber layer 2b are improved with the water-retaining fibers with a long fiber length.

The latitude of the hydrophobic fibers of the second fiber layer 2b is not particularly limited, and examples thereof include 1.1 to 8.8 dtex. However, the ease of intertwining between the hydrophobic fibers of the second fibrous layer 2b and the water-retaining fibers, which are the main fibers of the first fibrous layer 2a, that is, the ease of transfer of liquid excrement from the first fibrous layer 2a, (2a) From the standpoint of preventing peeling between the second fibrous layer 2b, the latitude of the hydrophobic fibers in the second fibrous layer 2b is smaller than the fineness of the water-retaining fibers in the first fibrous layer 2a (fine fiber diameter). ) is preferred.

In addition, the fiber length of the hydrophobic fibers of the second fiber layer 2b is not particularly limited, and examples thereof include 10 to 80 mm. However, the ease of intertwining between the hydrophobic fibers of the second fibrous layer 2b and the water-retaining fibers, which are the main fibers of the first fibrous layer 2a, that is, the ease of transfer of liquid excrement from the first fibrous layer 2a, (2a) From the standpoint of preventing peeling between the second fibrous layer 2b, the fiber length of the hydrophobic fibers of the second fibrous layer 2b is the fiber length of the water-retaining fibers of the first fibrous layer 2a and the second fibrous layer 2b. It is preferably long compared to the length. The average fiber length of the hydrophobic fibers of the second fiber layer 2b is, for example, 15 to 50 mm.

The thickness of each of the first fiber layer 2a and the second fiber layer 2b is not particularly limited, and is, for example, 0.05 to 4 mm, preferably 0.1 to 3 mm, and more preferably 0.2 to 2 mm. However, from the viewpoint of improving the tactile feel of the first fiber layer 2a and suppressing rewet-back to the wearer's skin, the thickness of the first fiber layer 2a is relatively thick, and the second fiber layer 2b It is preferable that the thickness of is relatively thin. Also, the thickness of the topsheet 2 is not particularly limited, and is, for example, 0.1 to 5 mm, preferably 0.4 to 4 mm, and more preferably 0.8 to 3 mm.

However, the ratio of types of fibers in a sheet such as a fiber layer is measured as follows.

That is, by coloring the water-retaining fiber and the hydrophobic fiber in different colors, respectively, the ratio of the types of fibers is measured. (1) The topsheet 2 is cut into a size of 70 mm x 70 mm and used as a sample. (2) By performing a coloring treatment with the reagent KayastainQ (Shikisen Co., Ltd.), only water-retaining fibers are dyed blue, and only hydrophobic fibers are colored yellow. (3) With a digital microscope VHX-100 manufactured by Keyence Corporation, the ratio of blue to yellow when viewed from the skin side of the sample (first fiber layer 2a) was measured in a range of 50 mm × 50 mm, and the first fiber layer was measured. It is set as the ratio of the kind of fiber in (2a). On the other hand, by measuring the ratio of blue to yellow when viewed from the non-skin surface (second fiber layer 2b) in the range of 50 mm × 50 mm, it is taken as the ratio of the types of fibers in the second fiber layer 2b.

In addition, the distance between fibers in a sheet such as a fiber layer is measured according to the following measuring method. (1) The topsheet 2 is cut into a size of 10 mm x 10 mm and used as a sample. (2) A digital microscope VHX-100 manufactured by Keyence Corporation (lens VH-Z20R + variable illumination attachment VH-K20) was used, photographing magnification: 200 times, measurement area: 1300 μm long × 1735 μm wide, and a surface sheet (2 An image is taken from each of the front surface (first fiber layer 2a) and the back surface (second fiber layer 2b) of . At that time, a total of 5 images are taken for each depth of 20 μm in the range of 0 to 100 μm in depth for each of the front and back surfaces. (3) From each obtained image, the area of the site|part where a fiber does not exist is calculated|required. At this time, the presence or absence of fibers in the pixels is determined according to whether the luminance of each pixel in each obtained image is lower than or higher than a predetermined luminance (threshold), and the presence or absence of fibers in the imaging area of each image is determined. . However, light is transmitted only to a region where no fiber exists, so that the light is bright, that is, the luminance is high. Thereby, the area of the region where no fibers exist in the imaging area is obtained. (4) Calculate the porosity by subtracting the area of the area where the obtained fiber does not exist from the area of the imaging area (measurement area) and dividing by the area of the imaging area (measurement area). The calculation is performed on images at every depth of 20 μm to calculate five porosity. (5) By calculating the average of the five porosity values, the porosity of each of the front surface (first fiber layer 2a) and back surface (second fiber layer 2b) of the topsheet 2 is determined. The size of the distance between fibers can be judged by comparing the size of the porosity. That is, when the porosity is large, it can be considered that the distance between fibers is large. For example, the porosity is 25.4% on the surface of the topsheet 2, that is, on the skin side (first fiber layer 2a: for example, 100% cotton), and on the back side, that is, on the non-skin side (second fiber layer 2b: for example, cotton). 60% + cotton of 40% synthetic fiber), the porosity was 24.5%.

In addition, the fiber length and average fiber length of fibers of a sheet such as a fiber layer are measured according to “A7.1.1A method (standard method) of “A7.1 Measurement of fiber length” in Annex A of JIS L 1015: 2010 on a glass plate with a scale. Method for measuring the length of individual fibers”. In addition, the above method is a test method corresponding to ISO 6989 issued in 1981.

In addition, the basis weight of a sheet such as a fibrous layer is measured according to the following measuring method. One fibrous layer is produced, and the fibrous layer is cut into a size of 5 cm × 5 cm as a sample, dried in an atmosphere of 100 ° C. or higher, and then the mass is measured. Next, the basis weight of the sample is calculated by dividing the measured mass by the area of the sample. A value obtained by averaging the basis weights of 10 samples is taken as the basis weight of the sheet.

In addition, the thickness of a sheet such as a fibrous layer is measured according to the following measuring method. Using a digital microscope VHX-100 manufactured by Keyence Corporation, an enlarged image from a direction perpendicular to the cut surface of the topsheet 2 is photographed. The enlarged image is an image enlarged at a magnification at which the entire thickness direction T of the topsheet 2 can be photographed, and the magnification is, for example, 20 to 50 times. The thickness of each fiber layer is measured in the 2D image converted from the obtained 3D image. The average value of the thicknesses measured at three separate cut surfaces is taken as the thickness of the topsheet 2.

As described above, in the sanitary napkin 1, since the ratio of water-retaining fibers in the first fibrous layer 2a located on the skin side of the topsheet 2 is relatively high, the topsheet 2 has a good feel to the touch. can do In addition, since the average fiber length of the water-retaining fibers included in the first fiber layer 2a is relatively long, it is possible to suppress a situation in which the average fiber length is too short and the fibers are not entangled with each other and fuzzing occurs, and the topsheet (2) The fall of the touch can be suppressed.

At that time, since the average fiber length of the water-retaining fibers included in the second fiber layer 2b is shorter than the average fiber length of the water-retaining fibers included in the first fiber layer 2a, the fibers constituting the second fiber layer 2b closer to each other. Therefore, since the average distance between fibers of the second fiber layer 2b can be shortened compared to the average distance between fibers of the first fiber layer 2a, capillarity can be more strongly generated in the second fiber layer 2b. , liquid excretion excreted on the skin-side surface of the first fibrous layer 2a can be quickly drawn into the second fibrous layer 2b. Then, the liquid excretion entrained in the second fibrous layer 2b can be rapidly transferred to the absorber 4 through the second fibrous layer 2b by means of hydrophobic fibers.

At this time, in the first fibrous layer 2a, the liquid excrement can be drawn into the 2nd fibrous layer 2b while spreading it widely in the plane direction by water-retaining fibers having a relatively long average fiber length. As a result, since the liquid excretion diffused widely in the planar direction in the topsheet 2 can be absorbed in a wide area in the planar direction in the absorber 4, the absorption performance can be improved.

In this way, the water absorption performance of the sanitary napkin 1 can be improved while the touch of the topsheet 2 is improved.

Further, in the case where the second fibrous layer 2b includes one or more fibrous layers on the non-skin side, that is, in the case where the topsheet 2 has a three-layer or multi-layer structure as a whole, from the viewpoint of further enhancing liquid permeability, In the fibrous layer closer to the surface of the non-skin side of the topsheet 2, it is preferable that the proportion of water-retaining fibers is relatively low and the average fiber length of water-retaining fibers is short.

In this embodiment, the fiber density of the first fiber layer 2a is smaller than that of the second fiber layer 2b. That is, a fiber density gradient exists such that the fiber density increases from the first fiber layer 2a to the second fiber layer 2b.

In the sanitary napkin 1 having such a configuration, first, the liquid excretion excreted on the skin-side surface of the topsheet 2 when worn, that is, the surface of the first fibrous layer 2a, is passed through the first fibrous layer 2a. ) can be entered. After that, the liquid excretion entrained in the first fibrous layer 2a can be stably transferred to the second fibrous layer 2b by the fiber density gradient. As a result, the layer in contact with the non-skin side of the second fibrous layer 2b ( Example: Auxiliary sheet, absorber (4)) can stably transfer liquid excrement. Therefore, it is possible to improve the water absorption performance while improving the tactile feel of the topsheet 2. In addition, the topsheet 2 of the sanitary napkin 1 need not have such a fiber density gradient.

However, when one or more fibrous layers are further provided on the surface of the non-skin side of the second fibrous layer 2b, that is, when the topsheet 2 has a three-layer or multi-layer structure, the ratio of the topsheet 2 It is preferable that the fiber layer closer to the skin-side surface has a relatively high fiber density. As a result, liquid permeability from the skin-side fibrous layer to the non-skin-side fibrous layer can be further improved, and liquid excretion can be more stably transferred to the auxiliary sheet or absorber 4.

However, when the second fibrous layer 2b includes one or a plurality of fibrous layers on the non-skin side, that is, when the topsheet 2 has a three-layer or multi-layer structure as a whole, the topsheet 2 has a non-skin layer. It is preferable that the fiber layer closer to the surface of the side has a relatively high fiber density. As a result, liquid permeability from the skin-side fibrous layer to the non-skin-side fibrous layer can be further improved, and liquid excretion can be more stably transferred to the auxiliary sheet or absorber 4.

In addition, the fiber density of a sheet like a fiber layer is measured, for example, by the following measuring method.

(1) The topsheet 2 is cut into a size of 10 mm x 10 mm and used as a sample. (2) A cut surface parallel to the thickness direction T of the sample is magnified and observed using a scanning electron microscope (JCM-5100 manufactured by Nippon Electronics Co., Ltd.). The magnification is a magnification that can measure the cross section of 30 to 60 fibers in one screen (eg, 150 to 500 times). (3) The observation area is divided into three parts in the thickness direction T into a skin-side layer, an intermediate layer, and a non-skin-side layer, the skin-side layer being the first fiber layer 2a, and the non-skin-side layer being the second. After forming the fiber layer 2b, the number of cross sections of fibers in each fiber layer is measured. That is, in a cut surface of a predetermined area, the number of cut fiber cross sections is counted. (4) The number of cross-sections of the obtained fiber is converted into the number of cross-sections of the fiber per 1 mm 2 , and this is taken as the fiber density (piece/mm 2 ). The measurement is performed at three locations, and the average value of the measured values is taken as the fiber density of the sample. That is, the density of the number of fibers is used as the fiber density. In other words, as the fiber density, the number of fibers per unit area in a cross section parallel to the thickness direction (T) is used. Also, as the fiber density, the number of fibers per unit volume may be used. The number of fibers per unit volume can be determined by, for example, X-ray CT analysis. The fiber density per unit area and the fiber density per unit volume are different in numerical value, but they are the same in a relative comparison of fiber densities between fiber layers (for example, comparison of size).

In this embodiment, the hydrophobic fibers included in the second fiber layer 2b include heat-sealable fibers that are heat-sealed to each other. That is, the heat-fusible fibers included in the hydrophobic fibers have junctions (fusion points) where the heat-fusible fibers are joined to each other by thermal fusion at the location where they come into contact with each other. It can be seen that these mutually bonded heat-fusible fibers form a kind of matrix of thermoplastic resin fibers in the second fiber layer 2b.

In the sanitary napkin 1 having such a configuration, the shape of the second fiber layer 2b can be stably maintained by the heat-sealable fibers heat-sealed to each other in the second fiber layer 2b. Therefore, even if the average fiber length of the water-retaining fibers included in the second fiber layer 2b is relatively short, the water-retaining fibers can be stably maintained so as not to be concentrated between (in the matrix of) the heat-sealable fibers. As a result, the liquid excrement drawn into the second fibrous layer 2b can be stably transferred to the absorber 4 (and auxiliary sheet 5) without being concentrated, and the absorption performance can be improved. Further, the hydrophobic fibers of the sanitary napkin 1 need not contain such heat-sealable fibers heat-sealed to each other.

In this embodiment, at least a part of the thermally fusible fibers of the second fiber layer 2b are exposed on the skin-side surface of the first fiber layer 2a. That is, at least a part of the thermally fusible fibers of the second fiber layer 2b are continuously drawn into the first fiber layer 2a from the second fiber layer 2b while stably maintaining the shape of the second fiber layer 2b. Furthermore, they reach the skin-side surface of the first fiber layer 2a.

In the sanitary napkin 1 having such a configuration, the heat-fusible fibers of the second fibrous layer 2b extend continuously into the first fibrous layer 2a, thereby retaining the water-retaining fibers of the first fibrous layer 2a. can be stably maintained between the heat-sealable fibers. Accordingly, even if the average distance between the fibers of the first fiber layer 2a is relatively long and the strength of the first fiber layer 2a is relatively weak, it is possible to suppress settling. In addition, by holding the water-retaining fibers of the first fiber layer 2a between the heat-fusible fibers, it is also possible to suppress the formation of fuzz. In this way, the tactile feel of the first fiber layer 2a can be improved. In addition, since a part of the heat-fusible fibers having no water retention in the second fibrous layer 2b exists in the first fibrous layer 2a, the second fibrous layer 2b is formed from the first fibrous layer 2a through the heat-fusible fibers. can promote the passage of liquid excreta into Thereby, liquid excretion can be stably transferred to the absorber 4 (and the auxiliary sheet 5). Further, the heat-fusible fibers of the second fibrous layer 2b of the sanitary napkin 1 need not be exposed to the surface of the first fibrous layer 2a.

In this embodiment, the fibers constituting the topsheet 2 are located at both ends in the width direction W of the topsheet 2 than at the center of the topsheet 2 in the width direction W. 2) is oriented in the longitudinal direction (L). That is, in the width direction W, in the topsheet 2, the fibers at the center have a relatively small orientation in the longitudinal direction L, and the fibers at both ends have a relatively large orientation in the longitudinal direction L.

In the sanitary napkin 1 having such a configuration, since the fiber orientation of the topsheet 2 is relatively random in the central portion, liquid excretion can be spread substantially concentrically, and the fiber orientation is longitudinal at both ends ( L), it is possible to spread liquid excrement reaching both ends in the longitudinal direction (L). That is, the sanitary napkin 1 can be used as a whole, and the absorption performance can be improved. In addition, at both ends of the topsheet 2 in the width direction W, since the number of fibers exposed from the edge is reduced, friction against the skin is reduced, and deterioration in tactile sensation can be suppressed. Further, the orientation of the fibers of the topsheet 2 of the sanitary napkin 1 need not be relatively large in the longitudinal direction L at both ends in the width direction W.

In the sanitary napkin 1, the excretory contact area XA is set at the center in the width direction W near the center slightly forward in the longitudinal direction L in plan view. The excretory port contact area XA is an area that faces or contacts the excretory port of the wearer when the sanitary napkin 1 is worn. The excretory contact area XA is set according to the type or use of the absorbent article. The excretory contact area XA is, for example, near the center slightly forward of the absorber 4 in the longitudinal direction L, about 1/4 to 1/2 of the total length of the absorber 4 in the longitudinal direction L. In this case, it is set approximately at the center of the absorber 4 in the width direction W at a width of about 1/2 to 1/3 of the total length of the absorber 4 in the width direction W.

In this embodiment, the sanitary napkin 1 is provided with a pair of pressing portions (compression grooves) 12, 12 continuously or intermittently located on both outer sides of the excretory contact area XA in the width direction W. do. In this embodiment, the sanitary napkin 1 further includes a pair of crimping parts (pressing grooves) 13, 13 at the rear of the pair of crimping parts 12, 12 in the longitudinal direction L, and Provided with crimping parts (compression grooves) 11 and 14 at the front and rear of the contact area XA in the longitudinal direction L, respectively, and a plurality of point-shaped crimping parts 15 in the excretory contact area XA do. These crimping portions 11 to 15 are formed by compressing the topsheet 2 and the absorber 4 in the thickness direction T. That is, the top sheet 2, the auxiliary sheet 5, and the absorbent body 4 (skin-side core wrap 4b and absorbent core 4a) are formed by being compressed in the thickness direction T. At that time, each crimping part includes a low density part (LPA) that is weakly compressed and formed at a shallow position and has a relatively low fiber density, and a high density part (HPA) that is strongly compressed and formed at a deep position and has a relatively high fiber density. have However, the criterion for "shallow" and "deep" is the surface of the topsheet 2 on the skin side. The low-density part LPA and the high-density part HPA can be referred to as a bottom part at a shallow position and a bottom part at a deep position in each compression section. The low-density part (LPA) and high-density part (HPA) of the crimping parts 11 to 15 are located in the absorbent core 4a. However, the high-density part HPA may reach the core wrap 4b on the non-skin side. Moreover, the shape of the crimping|compression-bonding parts 11-15 is arbitrary. In addition, the sanitary napkin 1 may not include at least one of the crimping portions 11 to 15 .

In this embodiment, at least a part of the heat-sealable fibers of the second fiber layer 2b are exposed on the inner surface of the crimping part in at least one of the crimping parts 11 to 15.

In the sanitary napkin 1 having such a configuration, the heat-sealable fibers are present in the first fibrous layer 2a so as to be exposed on the inner surface of the crimping part, so that even in the crimping part, the water-retaining fibers of the first fibrous layer 2a can be stably maintained between the heat-sealable fibers. As a result, even in the crimping part, even if the strength of the first fiber layer 2a is relatively weak, it is possible to suppress sinking and fluffing, and the tactile feel of the first fiber layer 2a in the crimping part can be improved. In addition, since a part of the heat-fusible fibers having no water retention in the second fiber layer 2b exist in the first fiber layer 2a in the crimping part, the first fibrous layer 2a in the crimping part passes through the heat-sealable fibers. ) to the second fibrous layer (2b) can promote the transfer of liquid excretion. Thereby, liquid excretion can be more stably transferred to the absorber 4 (and auxiliary sheet 5). Also, in the sanitary napkin 1, the heat-sealable fiber does not need to be exposed on the inner surface of the crimping portion.

In this embodiment, at least a part of the heat-sealable fibers of the second fiber layer 2b are exposed on the surface of the low density part (LPA) of the crimping part in at least one of the crimping parts 11 to 15.

In the sanitary napkin 1 having such a configuration, the heat-sealable fibers are present in the first fibrous layer 2a so as to be exposed on the surface of the low-density portion LPA, thereby forming the first fibrous layer 2a in the low-density portion LPA. of water-retaining fibers can be stably maintained between heat-sealable fibers. As a result, even if the strength of the first fiber layer 2a in the low-density portion LPA is relatively weak, it is possible to suppress sinking or fluffing, and to improve the feel of the first fiber layer 2a in the low-density portion LPA. can do good In addition, since a part of the heat-fusible fibers having no water retention in the second fibrous layer 2b is present in the first fibrous layer 2a in the low-density portion LPA, the heat-fusible fibers pass through the low-density portion LPA. The transfer of liquid excretion from the first fibrous layer 2a to the second fibrous layer 2b can be promoted. Thereby, liquid excretion can finally be more stably transferred to the absorber 4 (and auxiliary sheet 5). In addition, in the sanitary napkin 1, the heat-sealable fibers do not need to be exposed on the surface of the low-density portion LPA.

In this embodiment, the topsheet 2 has a concavo-convex structure. Fig. 3 shows a configuration example of a topsheet 2 according to the embodiment, Fig. 3 (a) is a plan view of the topsheet 2, and Fig. 3 (b) is IIb- of Fig. 3 (a) It is a cross section along line IIb. The first fiber layer 2a has an upper first upper surface 2aE and a lower first lower surface 2aF in the thickness direction T, and the second fiber layer 2b has a second upper surface in the thickness direction T. It has an upper surface 2bE and a lower second lower surface 2bF. Although the first lower surface 2aF and the second upper surface 2bE are imaginary boundaries between both fiber layers, they are not strict boundaries because some of the fibers of both fiber layers are drawn into different fiber layers by interlacing. The first fiber layer 2a includes a plurality of convex portions 21 continuously extending along the longitudinal direction L and positioned at intervals in the width direction W on the first upper surface 2aE, and the longitudinal direction. It extends continuously along (L) and has a plurality of concave portions 22 located between the convex portions 21 adjacent to each other. In this embodiment, each of the plurality of convex portions 21 is formed to be filled. In this way, since each of the plurality of convex portions 21 is formed in a hollow manner, each convex portion 21 becomes difficult to collapse, and the absorber 4 is removed from each convex portion 21 that is easy to come into contact with the wearer's body. ), the dryness of the surface of each convex portion 21 can be improved.

The second fiber layer 2b has a substantially flat shape except for the depressions 23 (described later) formed by compression. However, the second upper surface 2bE may rise slightly upward in the thickness direction T at a position corresponding to the convex portion 21 . Further, the second fiber layer 2b extends continuously along the longitudinal direction L to the second lower surface 2bF similarly to the first fiber layer 2a (but in a direction opposite to the thickness direction T), You may have a plurality of convex portions positioned at intervals in the direction W and a plurality of concave portions positioned between convex portions continuously extending along the longitudinal direction L and adjacent to each other. In that case, it is preferable that the position of the convex part 21 and the concave part 22 of the first fiber layer 2a and the position of the convex part and the concave part of the second fiber layer 2b are the same in plan view.

The first fibrous layer 2a and the second fibrous layer 2b are bonded to each other by interlacing. Examples of the entanglement method include a spunlace method and a water jet method. However, the bridging method is not limited to this example, and other bridging methods, such as an air-through method, may be used.

In this embodiment, the fiber density of the top part 21T of the convex part 21 is S1, the fiber density of the bottom part 22B of the concave part 22 is S2, and the top part of the convex part 21 ( 21T) and the region MP between the bottom portion 22B of the concave portion 22, when S3 is the fiber density, S1<S3<S2.

In the sanitary napkin 1 having such a configuration, in the topsheet, from the top portion 21T of the convex portion 21 having the low fiber density S1 through the region MP having the medium fiber density S3. , capillarity acts toward the bottom portion 22B of the concave portion 22 having a high fiber density S2. Therefore, the liquid excretion excreted on the most skin-side surface of the topsheet 2 (at or near the top 21T of the convex portion 21) is transferred to the non-skin-side surface of the topsheet 2. It can be made more easy to retract into the bottom part 22B of the recessed part 22 located in the vicinity of . Thereby, liquid excretion can be more stably transferred from the skin-side surface of the topsheet 2 to the absorber 4 (and auxiliary sheet 5) through the non-skin-side surface of the topsheet 2. . In addition, the fiber density gradient (S1<S3<S2) makes it difficult to rewet back liquid excrement once absorbed. In addition, since the fiber density of the convex portion 21 is low, the wearer can feel softness. Therefore, it is possible to improve the water absorption performance while improving the tactile feel of the topsheet. In the sanitary napkin 1, the topsheet 2 need not have the above concavo-convex structure and the above fiber density gradient.

In this embodiment, the topsheet 2 has a plurality of depressions in which the first fiber layer 2a and the second fiber layer 2b are compressed in the thickness direction T in each of the plurality of recesses 22. (23). The plurality of depressions 23 are intermittently arranged along the longitudinal direction L in each recess 22 and at equal or non-equal intervals. In the concave part 22 adjacent to the width direction W, the recessed part 23 may be the same position in the longitudinal direction L, and may not be the same position. In this embodiment, the concave portion 22 is arranged in a checkered pattern. In addition, the shape of the depression 23 in plan view is arbitrary, such as an ellipse.

In the sanitary napkin 1 having such a configuration, the first fibrous layer 2a and the second fibrous layer 2b are fixed by compression in the thickness direction T at the plurality of depressions 23, and thus , the water-retaining fibers of the first fiber layer are compressed. Accordingly, it is possible to suppress the occurrence of fluffing of the water-retaining fibers and to keep the topsheet good in touch. In addition, in the sanitary napkin 1, the topsheet 2 does not need to have the concave portion 23.

In this embodiment, the auxiliary sheet 5 is a liquid permeable sheet. Examples of the auxiliary sheet 5 include a liquid-permeable nonwoven fabric, a woven fabric, and a composite sheet thereof. The auxiliary sheet 5 has a slightly larger shape in the width direction W compared to the topsheet 2 . The auxiliary sheet 5 has a pair of loop portions 5L and 5L at both ends in the width direction W. The pair of loop portions 5L and 5L have both side portions in the width direction W of the auxiliary sheet 5, respectively, on the inner side of the auxiliary sheet 5 in the width direction W and on the non-skin side (thickness direction ( The lower side of T) is formed by folding in a loop shape. The ends of both side portions of the folded auxiliary sheet 5 are intermittently or continuously extended along the longitudinal direction L to the inner ends of the pair of facing the pair of side sheets 6, 6, and a pair of adhesive portions (not shown). not) are connected to each other. The loop portion 5L does not contain an elastic member. Further, the ends of both sides of the folded auxiliary sheet 5 are bonded to the non-skin side surface of the auxiliary sheet 5 with a pair of adhesive portions extending intermittently or continuously along the longitudinal direction L.

In the topsheet 2 containing a large amount of water-retaining fibers of the present embodiment, when the edges of the topsheet are rubbed, the water-retaining fibers are easily released from the edges and fall off. Here, in this embodiment, the dimension of the auxiliary sheet 5 in the width direction W is larger than the dimension of the topsheet 2 in the width direction W. That is, in a planar view, a portion outside of both end edges of the topsheet 2 in the width direction W of the auxiliary sheet 5 extends outward in the width direction W to form a pair of extensions. there is. In this embodiment, as the pair of extensions, a pair of loop portions 5L and 5L are formed at both ends of the auxiliary sheet 5 in the width direction W. Thereby, the force applied to the sanitary napkin 1 from the thighs of the wearer can be received by the pair of loop portions 5L and 5L (a pair of extension portions), and the topsheet 2 in the width direction W It can make it difficult for both end edges and the thigh to rub against each other. As a result, it is possible to suppress that both end edges of the topsheet 2 in the width direction W rub against each other and the water-retaining fibers unravel and fall off from both end edges of the topsheet 2 in the width direction W. decline can be suppressed. In particular, when the pair of loop portions 5L and 5L are used as the pair of extension portions, the force received by the sanitary napkin 1 from the thigh of the wearer is softened by the cushion action of the pair of loop portions 5L and 5L. It can be received, and the tactile sensation felt by the wearer can be improved. In particular, when the water-retaining fiber is cotton, this effect is remarkable.

In this embodiment, the auxiliary sheet 5 has a higher fiber density than the fiber density of the second fiber layer 2b. In the sanitary napkin 1 having such a configuration, the liquid excretion entrained in the second fibrous layer 2b can be more stably transferred to the auxiliary sheet 5 by capillary action. Thereby, liquid excrement can be more stably transferred from the topsheet 2 to the absorber 4 through the auxiliary sheet 5, and the absorbency performance can be improved while improving the touch of the topsheet 2. there is. Further, when the fiber density of the first fibrous layer 2a < the fiber density of the second fibrous layer 2b < the fiber density of the auxiliary sheet 5, liquid excrement is transferred to the auxiliary sheet 5 by capillarity. It is preferable because it can transfer more stably. In addition, the sanitary napkin 1 does not need to include the auxiliary sheet 5 or the loop portion 5L.

In this embodiment, the auxiliary sheet 5 contains water-retaining fibers corresponding to the topsheet 2, and when the topsheet 2 contains cellulose fibers (preferably cotton), cellulose fibers. (preferably cotton). In the sanitary napkin 1 having such a configuration, a water-retaining fiber having high liquid diffusivity, preferably a cellulosic fiber, more preferably cotton, is assisted from the first fibrous layer of the topsheet 2 through the second fibrous layer. It communicates with the seat 5. Therefore, by using the liquid diffusion of the liquid excrement by these fibers, the liquid excretion can be more stably transferred from the topsheet 2 to the absorber 4 via the auxiliary sheet 5, and the topsheet 2 It is possible to improve absorption performance while improving the tactile feel. In the sanitary napkin 1, the auxiliary sheet 5 may not contain water-retaining fibers, cellulose fibers or cotton. In that case, examples of the auxiliary sheet 5 include nonwoven fabrics of hydrophobic fibers, among which nonwoven fabrics of thermoplastic resin fibers are publicly used.

The absorber 4 is a layer having liquid absorption performance and liquid retention performance. In this embodiment, it is long in the longitudinal direction L in plan view, and both ends in the longitudinal direction L have a substantially semicircular shape. In this embodiment, the absorbent body 4 includes an absorbent core 4a and a core wrap 4b covering the absorbent core 4a. Examples of the absorbent core 4a include liquid-retaining substances containing absorbent fibers such as pulp fibers, and absorbent materials such as superabsorbent polymers (SAP). As the core wrap 4b, for example, a liquid-permeable sheet made of a hydrophilic nonwoven fabric such as a tissue may be used.

In the present embodiment, when the topsheet 2 contains cellulosic fibers (preferably cotton), the absorbent body 4 contains cellulosic fibers (preferably cotton) corresponding to the topsheet 2. It is preferable to include In that case, it is preferable that some of the cellulose fibers included in the topsheet 2 are in contact with the cellulose fibers included in the absorber 4 .

In the sanitary napkin 1 having such a configuration, cellulosic fibers having high liquid diffusivity pass from the first fibrous layer 2a to the second fibrous layer 2b of the topsheet 2 (in some cases, the auxiliary sheet It communicates to the absorber 4 via (5). Therefore, liquid excretion can be diffused directly from the topsheet 2 to the absorber 4 by utilizing liquid excretion by the cellulose fibers. Thereby, absorption performance can be improved. In the sanitary napkin 1, the absorber 4 may not contain cellulose fibers or cotton.

In this embodiment, the side sheet 6 is a water repellent sheet. As the side sheet 6, for example, a nonwoven fabric treated with water repellency or a synthetic resin film having air permeability is exemplified. In this embodiment, the back sheet 3 is a liquid impervious sheet. Examples of the back sheet 3 include a liquid impervious nonwoven fabric, a synthetic resin film, and a composite sheet thereof. In this embodiment, the wing part 9 is formed from the side sheet 6 and the back sheet 3.

In the sanitary napkin 1 of the present embodiment, the topsheet 2 is bonded to the auxiliary sheet 5 with an adhesive (eg, hot melt adhesive), and the auxiliary sheet 5 and the pair of side sheets 6, 6 The portion facing the absorber 4 in is bonded to the absorber 4 with an adhesive. A portion of the pair of side sheets 6, 6 and the absorber 4 facing the back sheet 3 is bonded to the back sheet 3 with an adhesive or the like.

In this embodiment, the sanitary napkin 1 further includes a plurality of adhesive portions 7 and a pair of adhesive portions 8 and 8 . The plurality of adhesive portions 7 have, for example, a substantially rectangular shape, are arranged on the non-skin side surface of the backsheet 3 so as to overlap with the absorbent body 4 in plan view, and extend continuously in the longitudinal direction L. and intermittently arranged in the width direction (W). The pair of adhesive portions 8 and 8 have, for example, a substantially rectangular shape, and are arranged on the surface on the non-skin side of the backsheet 3 so as to overlap the pair of wing portions 9 and 9 in a plan view, in the longitudinal direction ( L) is continuously extended. Examples of the adhesive portions 7 and 8 include hot melt adhesives.

Next, an example of a method for manufacturing the sanitary napkin 1 according to the present embodiment will be described.

4 is a schematic diagram showing a configuration example of a manufacturing apparatus 300 for the sanitary napkin 1. As shown in FIG. 5 is a diagram schematically illustrating a method for manufacturing the sanitary napkin 1. As shown in FIG. The manufacturing apparatus 300 has a conveyance direction (MD), a transverse direction (CD), and a vertical direction (TD) regarding conveyance of materials such as sheets and semi-finished products. In this embodiment, the longitudinal direction, the width direction, and the thickness direction of the material or semi-finished product are all the same as the transport direction (MD), the transverse direction (CD), and the vertical direction (TD).

First, the second fiber web P11 corresponding to the second fiber layer 2b is formed by the first carding machine 110. The first carding machine 110 is a dry type roller card using a single card or double card generally used for forming a fiber web. The second fibrous web P11 includes water-retaining fibers and hydrophobic fibers. The second fibrous web P11 is conveyed in the conveying direction MD by a conveying device (not shown).

Next, the first fiber web P12 corresponding to the first fiber layer 2a is formed by the second carding machine 120. The second carding machine 120 is also the same dry roller card as the first carding machine 110 . The first fibrous web P12 contains water-retaining fibers. The first fiber web P12 is laminated on the second fiber web P11 being conveyed by the conveying device. As a result, a composite fiber web P13 having a two-layer structure in which the first fiber web P12 and the second fiber web P11 are laminated is formed, and is conveyed in the conveying direction (MD) by the conveying device. In addition, the ratio of each fiber in each fiber web can be controlled by the ratio of the raw material fibers supplied to each carding machine.

Next, the composite fiber web P13 having a two-layer structure is subjected to a water jet treatment by the water jet treatment machine 130, and the fibers are entangled with each other. As a result, a first continuous sheet (spunlace nonwoven fabric) P14 is formed. Here, in the water jet treatment, the composite fiber web P13 is placed on a continuously moving mesh belt, and a high-pressure water jet is jetted from the upper surface side of the composite fiber web P13 to entangle the fibers. The properties of the first continuous sheet P14 obtained by the water jet treatment are appropriately adjusted or changed depending on the mass of each fiber web, the hole diameter of the spray nozzle, the number of holes (pitch) of the spray nozzle, the passing speed of the fiber web, and the like. can After that, the first continuous sheet P14 passed through the water jet treatment machine 130 is dried by the dryer 140 . The dried 1st continuous sheet|seat P15 is conveyed by the conveyance apparatus in the conveyance direction MD.

Further, the method of forming the fibrous web corresponding to each fibrous layer is not limited to the above method, and for example, a wet method or the like may be employed. In addition, the method of joining the web is not limited to the method described above, and for example, a water current entanglement method or a needle punch method may be employed. In addition, the first continuous sheet P15 is manufactured in a manufacturing factory separate from the manufacturing factory of the sanitary napkin 1, wound into a roll, and then sent to the manufacturing factory of the sanitary napkin 1 in the form of a roll. may be supplied.

Next, the first continuous sheet P16, which is the first continuous sheet P15 conveyed by a conveying device (not shown) or unwound from a roll (not shown), is conveyed in the conveying direction MD while being conveyed to the shaping device. (210). Here, the shaping device 210 includes shaping rolls 210a and 210b extending in the circumferential direction on an outer circumferential surface and having concavo-convex portions that engage with each other. Then, the first continuous sheet P16 is sandwiched between the concavo-convex portions of the shaping rolls 210a and 210b, and the concavo-convex structure extending in the transport direction MD is shaped. After that, the first continuous sheet P16 is conveyed in the conveyance direction MD. Thereby, a continuous topsheet P16 for the topsheet 2 is formed.

Next, the continuous auxiliary sheet AS for the auxiliary sheet 5 unwound from the material roll WR3 is supplied to the heating device 220 while being conveyed in the conveying direction MD. Subsequently, the continuous auxiliary sheet AS is supplied to the application device 302 after being subjected to heat treatment to recover its volume. In addition, an adhesive (eg, hot melt adhesive) is applied to one side of the continuous auxiliary sheet AS in a predetermined pattern (eg, a spiral pattern). Thereafter, the continuous auxiliary sheet AS and the continuous topsheet P16 are supplied to the bonding device 230 while being conveyed in the conveying direction MD, and the pair of bonding rolls 230a and 230b of the bonding apparatus 230 interposed and bonded. As a result, as shown in Fig. 5(a), a continuous topsheet P17 is formed.

Next, the continuous topsheet P17 is supplied to the coating device 303 while being conveyed in the conveyance direction MD. And the continuous topsheet P17 is the lower surface of the continuous topsheet P17 (continuous auxiliary sheet AS) in the vertical direction TD and the end in the transverse direction CD, in the transport direction MD. An adhesive (eg, hot melt adhesive) is applied in a predetermined pattern along the . Next, the continuous topsheet P17 is supplied to the loop forming apparatus 240 while being conveyed in the conveying direction MD. Then, both end portions of the continuous auxiliary sheet AS of the continuous surface sheet P17 in the transverse direction CD are folded toward the central portion in a loop shape by a folding jig such as a sailor of the loop forming device 240. . As a result, a pair of side portions ASL and ASL corresponding to the pair of loop portions 5L and 5L are formed on both sides of the continuous topsheet P17 in the transverse direction CD. Thereby, as shown in Fig. 5(b), a continuous topsheet P18 is formed.

Next, the continuous side sheet SS for the side sheet 6 unwound from the material roll WR4 is supplied to the cutting device 250 while being conveyed in the conveying direction MD. Then, the continuous side sheet SS is cut into two halves in the transverse direction CD along the conveying direction MD at a position at the center of the transverse direction CD, and a pair of continuous side sheets adjacent to the transverse direction CD. Side sheets SSa and SSb are formed. After that, the pair of continuous side sheets SSa and SSb are supplied to the pair of applicators 303a and 303b. An adhesive (eg, hot melt adhesive) is applied in a predetermined pattern (eg, a stripe pattern) to an inner end of each of the pair of continuous side sheets SSa and SSb in the transverse direction CD. Next, the pair of continuous side sheets SSa and SSb and the continuous topsheet P8 are supplied to the bonding device 260 while being conveyed in the conveyance direction MD, and the pair of bonding rolls 260a of the bonding apparatus 260 , 260b) are sandwiched between and joined. Thereby, the pair of side parts ASL and ASL and the pair of continuous side sheets SSa and SSb in the continuous topsheet P18 are bonded, respectively. Thereby, as shown in Fig. 5(c), the continuous topsheet P2 is formed.

Next, the continuous surface sheet P2 is supplied to the application device 305, and an adhesive (e.g., hot melt adhesive) is applied in a predetermined pattern to the side closer to the pair of continuous side sheets SSa and SSb. Next, the continuous topsheet P2 and the absorber P3 lined up in the conveying direction MD at predetermined intervals are supplied to the bonding device 270 while being conveyed in the conveying direction MD. Then, the continuous topsheet P2 and the absorber P3 are bonded by being sandwiched between a pair of bonding rolls 270a and 270b of the bonding device 270 . A semi-finished product P4 is thereby formed. Subsequently, the semifinished product P4 is supplied to the crimping device 280 while being conveyed in the conveyance direction MD. In the crimping device 280, an embossing roll 280a having a convex portion for crimping on an outer circumferential surface and an anvil roll 280b are disposed facing each other. Then, the semi-finished product P4 is pressed between the emboss roll 280a and the anvil roll 280b. As a result, crimping portions 11 to 15 extending from the continuous topsheet P2 to the absorber P3 in the vertical direction TD are formed, thereby forming the semifinished product P5. In addition, each crimping part may be crimped with a different crimping device. Next, the continuous back sheet BS for the back sheet 3 is supplied to the bonding device 290 from the fourth material roll WR4 while being conveyed in the conveying direction MD. An adhesive (eg, hot melt adhesive) is applied to one side of the continuous back sheet BS by an application device 306 . On the other hand, half-finished product P5 is supplied to the bonding apparatus 290, being conveyed in the conveyance direction MD. Then, the continuous backsheet BS and the semifinished product P5 are bonded by being sandwiched between a pair of bonding rolls 290a and 290b of the bonding device 290 . As a result, as shown in FIG. 5(d), a semifinished product P6 in which the continuous backsheet BS and the semifinished product P5 are laminated in the vertical direction TD is formed. Thereafter, the release sheet CT (adhesive portions 7, 8) with the adhesive is bonded to the semifinished product P6, and the peripheral portion of the semifinished product P6 bonded with the release sheet CT is the sanitary napkin 1 ), the sanitary napkin 1 is formed.

In the above manner, the sanitary napkin 1 is manufactured.

However, as a method of intertwining the composite fiber web P13 having a two-layer structure, an air through method may be used. That is, it is a method in which the composite fiber web P13 is conveyed to a heating device, and the fibers of the composite fiber web P13 are entangled with each other by heating air in the heating device.

(Second Embodiment)

Hereinafter, the difference between the sanitary napkin 1 of the second embodiment and the sanitary napkin 1 of the first embodiment will be mainly described. The sanitary napkin 1 of the present embodiment differs from the sanitary napkin 1 of the first embodiment in that the fiber density of the first fibrous layer 2a is smaller than that of the second fibrous layer 2b. . That is, in the sanitary napkin 1 of this embodiment, a fiber density gradient exists such that the fiber density increases from the first fiber layer 2a to the second fiber layer 2b. Here, the fiber density is the density of the number of fibers.

In the sanitary napkin 1 having such a configuration, since the fiber density of the second fibrous layer 2b is higher than that of the first fibrous layer 2a, the fibers constituting the second fibrous layer 2b are further separated from each other. can approach Therefore, since the average distance between fibers of the second fiber layer 2b can be shortened compared to the average distance between fibers of the first fiber layer 2a, capillarity can be more strongly generated in the second fiber layer 2b. When worn, liquid excrement excreted on the skin-side surface of the topsheet 2, that is, on the surface of the first fibrous layer 2a, can be drawn into the first fibrous layer 2a. Then, the liquid excretion entrained in the second fibrous layer 2b can be rapidly transferred to the absorber 4 through the second fibrous layer 2b by means of hydrophobic fibers. As a result, the layer in contact with the non-skin side of the second fibrous layer 2b ( Example: Auxiliary sheet, absorber (4)) can stably transfer liquid excrement.

At this time, in the first fibrous layer 2a, the liquid excrement can be drawn into the second fibrous layer 2b while being spread widely in the plane direction by the water-retaining fibers. As a result, since the liquid excretion diffused widely in the planar direction in the topsheet 2 can be absorbed in a wide area in the planar direction in the absorber 4, the absorption performance can be improved.

Therefore, it is possible to improve the water absorption performance while improving the tactile feel of the topsheet 2.

In the present embodiment, as in the first embodiment, the average fiber length of the water-retaining fibers of the second fiber layer 2b may be shorter than the average fiber length of the water-retaining fibers of the first fiber layer 2a, but it does not have to be shorter. When it is short, the same effect as in the case where the fiber density of the first fiber layer 2a is smaller than the fiber density of the second fiber layer 2b in the first embodiment can be exhibited.

On the other hand, if it is not short, the fiber length of the water-retaining fibers of the second fiber layer 2b is not particularly limited, and may take the same value as that of the first fiber layer 2a, for example, 10 to 80 mm. there is.

The absorbent article of the present invention is not limited to each of the above-described embodiments, and can be appropriately combined or modified without departing from the purpose or spirit of the present invention.

1: Sanitary napkin (absorbent article)
2: surface sheet
2a: first fiber layer
2b: second fiber layer

Claims (14)

An absorbent article comprising a topsheet, a backsheet, and an absorbent body positioned between the topsheet and the backsheet, comprising:
The surface sheet,
A first fiber layer containing water-retaining fibers;
A second fibrous layer adjacent to the non-skin side of the first fibrous layer and containing hydrophobic fibers and water-retaining fibers
to provide,
The skin-side surface of the first fiber layer constitutes the skin-side surface of the topsheet;
the non-skin side surface of the second fiber layer constitutes the non-skin side surface of the topsheet;
The ratio of the water-retaining fibers in the fibers constituting the first fiber layer is greater than the ratio of the water-retaining fibers in the fibers constituting the second fiber layer;
The absorbent article, wherein the average distance between fibers of the second fibrous layer is shorter than the average distance between fibers of the first fibrous layer. An absorbent article comprising a topsheet, a backsheet, and an absorbent body positioned between the topsheet and the backsheet, comprising:
The surface sheet,
A first fibrous layer containing water-retaining fibers;
A second fibrous layer adjacent to the non-skin side of the first fibrous layer and containing hydrophobic fibers and water-retaining fibers
to provide,
The skin-side surface of the first fiber layer constitutes the skin-side surface of the topsheet;
the non-skin side surface of the second fiber layer constitutes the non-skin side surface of the topsheet;
The ratio of the water-retaining fibers in the fibers constituting the first fiber layer is greater than the ratio of the water-retaining fibers in the fibers constituting the second fiber layer;
The absorbent article of claim 1, wherein the fiber density of the first fibrous layer is smaller than that of the second fibrous layer. According to claim 2,
The absorbent article further comprises an auxiliary sheet having a higher fiber density than that of the second fiber layer, between the topsheet and the absorbent body. According to any one of claims 1 to 3,
The absorbent article, wherein the hydrophobic fibers included in the second fiber layer include heat-sealable fibers heat-sealed to each other. According to claim 4,
The absorbent article, wherein at least a part of the heat-sealable fibers of the second fiber layer are exposed on the skin-side surface of the first fiber layer. According to claim 4,
in the thickness direction of the absorbent article, a compression portion in which the topsheet and the absorbent body are compressed;
The absorbent article according to claim 1 , wherein at least a portion of the heat-sealable fibers of the second fiber layer are exposed on an inner surface of the crimping portion. According to claim 6,
The compression part,
a low-density portion having a shallow depth in the thickness direction of the absorbent article;
The high-density portion with a deep depth in the thickness direction of the absorbent article
including,
The absorbent article, wherein at least a part of the heat-sealable fibers of the second fiber layer are exposed on the surface of the low-density portion. According to any one of claims 1 to 3,
The surface sheet,
a plurality of convex portions extending along the longitudinal direction of the absorbent article and positioned at intervals in the width direction of the absorbent article;
A plurality of concave portions extending along the longitudinal direction of the absorbent article and located between convex portions adjacent to each other.
has,
In the topsheet, when the fiber density of the top of the convex portion is S1, the fiber density of the bottom of the concave portion is S2, and the fiber density of the region between the top of the convex portion and the bottom of the concave portion is S3 An absorbent article where S1<S3<S2. According to claim 8,
The absorbent article is characterized in that the topsheet has a plurality of recesses compressed from the first fiber layer to the second fiber layer in the thickness direction of the absorbent article, in each of the plurality of recesses. According to any one of claims 1 to 3,
An average fiber length of the hydrophobic fibers of the second fibrous layer is longer than an average fiber length of the water-retaining fibers of the first fibrous layer and the second fibrous layer. According to any one of claims 1 to 3,
The water-retaining fibers included in the topsheet are cellulose-based fibers,
The absorbent body includes cellulosic fibers,
The absorbent article according to claim 1 , wherein a part of the cellulose-based fibers included in the topsheet is in contact with the cellulose-based fibers included in the absorber. According to any one of claims 1 to 3,
The absorbent article according to claim 1 , wherein the fibers constituting the topsheet are oriented in the longitudinal direction of the topsheet at both ends in the width direction of the topsheet, rather than at a central portion in the width direction of the topsheet. According to any one of claims 1 to 3,
The absorbent article of claim 1 , wherein the water-retaining fiber included in the topsheet is cotton. According to any one of claims 1 to 3,
Further comprising an auxiliary sheet positioned between the topsheet and the absorber,
The absorbent article according to claim 1 , wherein a dimension of the topsheet in the width direction is smaller than a dimension of the auxiliary sheet in the width direction.