阅读说明：本技术 吸收性物品以及其制造方法 (Absorbent article and method for manufacturing same ) 是由 曽我部瑶介 野田祐树 黑田贤一郎 嵯峨知行 细川雅司 东秀树 于 2020-04-20 设计创作，主要内容包括：本发明提供一种吸收性物品,该吸收性物品能够最大限度地使用吸收体的吸收区域并且吸收效率优异。本发明的吸收性物品的特征在于,其具备由无纺布构成的表面片(2)、背面片(3)以及位于这些片材之间的吸收体(4),并且具有使所述表面片(2)与所述吸收体(4)一起朝向所述吸收性物品的非肌肤相对面侧(S2)凹陷的多个凹部(6),而且,所述多个凹部(6)分别由开口部(61)和吸收体侧凹部(62)形成,开口部(61)由所述表面片(2)的连续的切断面形成,吸收体侧凹部(62)位于所述开口部(61)的所述非肌肤相对面侧(S2)且具有周壁部(63)和底部(64),所述底部(64)具有朝向所述吸收性物品的肌肤相对面侧(S1)突出的凸部(65)。(The invention provides an absorbent article which can use the absorption area of an absorber to the maximum extent and has excellent absorption efficiency. The absorbent article is characterized by comprising a front sheet (2) made of nonwoven fabric, a back sheet (3), and an absorbent body (4) positioned between the sheets, and having a plurality of concave sections (6) that recess the front sheet (2) together with the absorbent body (4) toward the non-skin-facing surface side (S2) of the absorbent article, wherein the plurality of concave sections (6) are formed by an opening section (61) and an absorbent body-side concave section (62), the opening section (61) is formed by a continuous cut surface of the front sheet (2), the absorbent body-side concave section (62) is positioned on the non-skin-facing surface side (S2) of the opening section (61) and has a peripheral wall section (63) and a bottom section (64), and the bottom section (64) has a convex section (65) that protrudes toward the skin-facing surface side (S1) of the absorbent article.)

1. An absorbent article comprising a front sheet and a back sheet each comprising a nonwoven fabric, and an absorbent body located between the sheets,

the absorbent article has a plurality of concave portions that are recessed toward the non-skin-facing surface side of the absorbent article together with the absorbent body,

the plurality of concave portions are each formed by an opening portion formed by a continuous cut surface of the top sheet and an absorbent-body-side concave portion located on the non-skin-facing surface side of the opening portion and having a peripheral wall portion and a bottom portion,

the bottom portion has a convex portion that protrudes toward the skin-facing side of the absorbent article.

2. The absorbent article according to claim 1,

at least a part of the plurality of concave portions has a low fiber density portion that extends over the entire circumference of the peripheral wall portion at an end portion of the peripheral wall portion on a side close to the bottom portion and that has a relatively low fiber density.

3. The absorbent article according to claim 2,

the low fiber density portion is a void portion extending in a direction away from the recess.

4. The absorbent article according to any one of claims 1 to 3,

in the recessed portion, an opening area of the opening portion is smaller than an opening area of an end portion of the peripheral wall portion on a side close to the bottom portion.

5. The absorbent article according to any one of claims 1 to 4,

the bottom portion has a bottom central portion located at the center and a bottom peripheral portion adjacent to the periphery of the bottom central portion in a plan view,

the protrusion has a top at the bottom center portion.

6. The absorbent article according to claim 5,

the fiber density of the bottom peripheral portion is greater than the fiber density of the bottom central portion.

7. The absorbent article according to any one of claims 1 to 6,

the absorptive article has a diffusion sheet between the surface sheet and the absorber,

the plurality of concave portions each have a diffusion sheet side opening portion formed by a continuous cut surface of the diffusion sheet between the opening portion and the absorber side concave portion.

8. The absorbent article according to any one of claims 1 to 7,

the absorbent article has an excretory opening corresponding region corresponding to an excretory opening of a wearer when worn in a plan view,

the drain opening corresponding region overlaps with a recess forming region in which the plurality of recesses are formed.

9. The absorbent article of claim 8,

the absorbent article has a plurality of non-skin-facing surface-side concave portions recessed from a surface of the absorbent body on the non-skin-facing surface side at positions corresponding to the plurality of concave portions in the thickness direction.

10. The absorbent article according to claim 8 or 9,

the portion of the absorber overlapping the concave portion forming region in the thickness direction is a middle protrusion portion having a relatively large thickness.

11. The absorbent article according to claim 9 or 10,

the absorbent article has a longitudinal direction and a width direction in a plan view, and has a pair of compressed portions extending in the longitudinal direction on the outer sides of the recess-forming regions in the width direction.

12. A method for manufacturing an absorbent article according to any one of claims 1 to 11, wherein the step of forming the absorbent article is carried out by a method comprising the steps of,

the manufacturing method comprises a step of forming a concave part,

in the concave portion forming step, the plurality of concave portions are formed by pressing a laminate including the top sheet and the absorbent body from the side of the top sheet with a plurality of pins, cutting the top sheet, and compressing the absorbent body in the thickness direction,

the plurality of pins each have a tip end portion having a recess for forming the convex portion on the tip end surface, and a non-tip end portion that is an end portion on the opposite side to the tip end portion.

13. The method of manufacturing an absorbent article according to claim 12,

the tip end portion of each of the plurality of pins has a smaller diameter than the non-tip end portion.

Technical Field

The present invention relates to an absorbent article such as a sanitary napkin and a method for producing the same.

Background

Since absorbent articles such as sanitary napkins and disposable diapers are worn for a long time while being in contact with the crotch of a wearer, various techniques have been studied for rapidly absorbing excrement discharged from the wearer and for preventing the excrement from leaking out so as not to cause discomfort or discomfort to the wearer.

For example, patent document 1 discloses an absorbent body having an air-laid nonwoven fabric and a liquid-permeable sheet disposed on one side of the air-laid nonwoven fabric, wherein the air-laid nonwoven fabric and the liquid-permeable sheet are embossed together to form a plurality of discrete concave portions each independently on one side of the liquid-permeable sheet, and the liquid-permeable sheet is partially opened and partially exposed in the concave portions. With the absorbent disclosed in patent document 1, both low-viscosity loose stool and high-viscosity loose stool can be absorbed or retained, and leakage can be prevented.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2003-204993

Disclosure of Invention

Problems to be solved by the invention

However, the absorbent body disclosed in patent document 1 is configured such that a part of the liquid-permeable sheet (top sheet) is opened in the concave portion and a part of the air-laid nonwoven fabric (sheet-like absorbent material) is exposed, and therefore, in the concave portion, at a portion where the liquid-permeable sheet is opened and the air-laid nonwoven fabric is exposed, excrement such as menstrual blood discharged from the wearer is easily transferred to the air-laid nonwoven fabric, while, at a portion where the liquid-permeable sheet is not opened and the air-laid nonwoven fabric is not exposed, excrement is hardly transferred to the air-laid nonwoven fabric.

Therefore, the absorber disclosed in patent document 1 has the following problems: it is difficult for excrement such as menstrual blood that reaches the inside of the concave portion to uniformly migrate toward the peripheral portion thereof around the concave portion, and it is difficult to uniformly absorb excrement in a wider area of the absorbent body (that is, the absorption area of the absorbent body cannot be used to the maximum extent, and the absorption efficiency is poor).

Accordingly, an object of the present invention is to provide an absorbent article which can use the absorption region of the absorber to the maximum and has excellent absorption efficiency.

Means for solving the problems

One aspect of the present invention (claim 1) is an absorbent article comprising a topsheet and a backsheet each comprising a nonwoven fabric, and an absorbent body located between the sheets,

the absorbent article has a plurality of concave portions that are recessed toward the non-skin-facing surface side of the absorbent article together with the absorbent body,

the plurality of concave portions are each formed by an opening portion formed by a continuous cut surface of the top sheet and an absorbent-body-side concave portion located on the non-skin-facing surface side of the opening portion and having a peripheral wall portion and a bottom portion,

the bottom portion has a convex portion that protrudes toward the skin-facing side of the absorbent article.

In the absorbent article according to the present invention, the plurality of concave portions are each formed by the opening portion formed by the continuous cut surface of the top sheet and the absorbent-side concave portion located on the non-skin-facing surface side of the opening portion and having the peripheral wall portion and the bottom portion, and the top sheet is completely opened in each concave portion and the absorbent body is exposed entirely in the peripheral wall portion, so that excreta such as menstrual blood discharged from the wearer is likely to be transferred uniformly to the peripheral portion of the concave portion via the peripheral wall portion.

Therefore, in the absorbent article according to the present invention, the convex portion formed in the bottom portion can diffuse the excrement such as menstrual blood flowing into the concave portion in the circumferential direction, and the diffused excrement can be uniformly transferred to the peripheral portion of the concave portion via the peripheral wall portion, and as a result, the excrement can be uniformly absorbed in a wider area of the absorbent body.

Therefore, the absorbent article according to the present invention can utilize the absorption region of the absorber to the maximum extent and can exhibit excellent absorption efficiency.

In addition, in another aspect (aspect 2) of the present invention, the absorbent article according to aspect 1 is characterized in that at least a part of the plurality of concave portions has a low fiber density portion that extends over the entire circumference of the peripheral wall portion at an end portion on the side of the peripheral wall portion closer to the bottom portion and that has a relatively low fiber density.

In the absorbent article according to the present invention, the low fiber density portion of the peripheral wall portion, which extends over the entire periphery of the peripheral wall portion at the end portion on the side closer to the bottom portion, has a relatively low fiber density (i.e., is lower than the other portion of the peripheral wall portion), and the low fiber density portion easily absorbs excrement, so that excrement flowing toward the bottom portion or excrement spreading by the convex portion can be quickly and uniformly transferred into the absorbent body via the low fiber density portion of the peripheral wall portion.

In still another aspect (aspect 3) of the present invention, the absorbent article according to aspect 2 is characterized in that the low fiber density portion is a void portion extending in a direction away from the concave portion.

In the absorbent article according to the present invention, the low fiber density portion is a void portion extending in a direction away from the concave portion, and therefore, the excrement flowing toward the bottom portion or the excrement spreading by the convex portion can be more quickly and uniformly transferred into the absorbent body through the void portion of the peripheral wall portion.

In still another aspect (aspect 4) of the present invention, in the absorbent article according to any one of aspects 1 to 3, an opening area of the opening is smaller in the concave portion than an opening area of an end portion of the peripheral wall portion on a side closer to the bottom portion.

In the absorbent article according to the present invention, since the opening area of the opening of the concave portion is smaller than the opening area of the end portion of the peripheral wall portion on the side closer to the bottom portion, it is easy to uniformly absorb excrement in a wider area of the absorbent body, and it is difficult for the excrement absorbed by the absorbent body to flow back to the skin-facing surface of the absorbent article through the concave portion.

In still another aspect (aspect 5) of the present invention, the absorbent article according to any one of aspects 1 to 4 is characterized in that the bottom portion has a bottom central portion located at the center and a bottom peripheral portion adjacent to the periphery of the bottom central portion in a plan view,

the protrusion has a top at the bottom center portion.

In the absorbent article according to the present invention, the convex portion has a top portion at the central portion of the bottom portion, and the excrement flowing into the concave portion can be spread more uniformly in the peripheral direction at the convex portion, and therefore the excrement can be transferred more uniformly to the peripheral portion of the concave portion.

In still another aspect (aspect 6) of the present invention, the absorbent article according to aspect 5 is characterized in that the fiber density of the bottom peripheral portion is higher than the fiber density of the bottom central portion.

In the absorbent article according to the present invention, the fiber density of the bottom peripheral portion is made higher than the fiber density of the bottom central portion, so that the excrement flowing into the concave portion is easily drawn into the bottom peripheral portion by the capillary phenomenon, and therefore the excrement reaching the convex portion can be more reliably diffused in the peripheral direction.

In still another aspect (aspect 7) of the present invention, the absorbent article according to any one of aspects 1 to 6 is characterized in that the absorbent article has a diffusion sheet between the top sheet and the absorber,

the plurality of concave portions each have a diffusion sheet side opening portion formed by a continuous cut surface of the diffusion sheet between the opening portion and the absorber side concave portion.

In the absorbent article according to the present invention, since the diffusion sheet is provided between the top sheet and the absorber and has the diffusion sheet-side opening portion in the same manner as the top sheet, the excrement supplied between the plurality of concave portions and transmitted through the top sheet can be diffused in the planar direction by the diffusion sheet, or the excrement flowing into the concave portions can be diffused in the planar direction from the diffusion sheet-side opening portion by the diffusion sheet.

Thus, the absorbent article according to the present aspect can uniformly absorb excrement in a wider area of the absorbent body.

In still another aspect (aspect 8) of the present invention, the absorbent article according to any one of aspects 1 to 7 is characterized in that the absorbent article has an excretory opening corresponding region corresponding to an excretory opening of a wearer when worn in a plan view,

the drain opening corresponding region overlaps with a recess forming region in which the plurality of recesses are formed.

In the absorbent article according to the present invention, the excretory opening corresponding region is a region overlapping with the recessed portion formation region, and therefore, excreta discharged from the wearer can flow into the plurality of recessed portions more efficiently.

In still another aspect of the present invention (claim 9), the absorbent article according to claim 8 is characterized in that the absorbent article has a plurality of non-skin facing surface-side concave portions that are recessed from a surface of the absorbent body on the non-skin facing surface side at positions corresponding to the plurality of concave portions in the thickness direction, respectively.

In the absorbent article according to the present invention, since the plurality of non-skin-facing surface-side concave portions are provided at positions corresponding to the plurality of concave portions in the thickness direction, the absorbent article is easily bent with the bottom portion sandwiched between the concave portions and the non-skin-facing surface-side concave portions as a base point, and the concave portion forming region in which the plurality of concave portions are formed is easily deformed in conformity with the shape of the wearer's crotch when the absorbent article is worn.

Thus, the absorbent article according to the present invention can bring the concave portion forming region into contact with the skin of the wearer when worn, and can exhibit more excellent absorption efficiency.

In still another aspect (aspect 10) of the present invention, the absorbent article according to aspect 8 or 9 is characterized in that a portion of the absorber overlapping the concave portion forming region in a thickness direction is a middle protrusion portion having a relatively large thickness.

In the absorbent article according to the present invention, since the portion of the absorbent body overlapping the concave portion forming region is the middle protrusion portion, the concave portion forming region overlapping the middle protrusion portion is easily attached to the crotch portion of the wearer when the absorbent article is worn, and the excrement discharged from the wearer can more reliably flow into the plurality of concave portions.

In still another aspect (aspect 11) of the present invention, the absorbent article according to aspect 9 or 10 is characterized in that the absorbent article has a longitudinal direction and a width direction in a plan view, and has a pair of compressed portions extending in the longitudinal direction on outer sides of the recess forming regions in the width direction.

In the absorbent article according to the present invention, since the pair of compressed portions extending in the longitudinal direction are provided on the outer sides in the width direction of the concave portion forming region, the pair of compressed portions can be deformed so as to form the cross-sectional shape of the absorbent article in the width direction into a substantially W-letter shape, each serving as a bending base point.

In the absorbent article according to the present invention, the pair of compressed portions are formed by compressing the absorbent core in the concave portion forming region, and the pair of compressed portions are formed by compressing the absorbent core in the concave portion forming region.

A further aspect of the present invention (claim 12) is the method of manufacturing an absorbent article according to any one of claims 1 to 11, including a concave portion forming step of pressing a laminate including the top sheet and the absorbent body from a top sheet side with a plurality of pins to cut the top sheet and compress the absorbent body in a thickness direction to form the plurality of concave portions,

the plurality of pins each have a tip end portion having a recess for forming the convex portion on the tip end surface, and a non-tip end portion that is an end portion on the opposite side to the tip end portion.

In the manufacturing method according to the present invention, the plurality of pins having the concave portions for forming the convex portions on the distal end surface are pressed from the surface sheet side to cut the surface sheet and compress the absorbent body in the thickness direction, so that the concave portions having the specific structure of the absorbent article can be easily formed in one step.

Thus, the manufacturing method according to the present invention can efficiently and easily obtain an absorbent article that can use the absorption region of the absorbent body to the maximum extent and can exhibit excellent absorption efficiency.

In still another aspect (aspect 13) of the present invention, the manufacturing method according to aspect 12 is characterized in that the diameter of the distal end portion of each of the plurality of pins is smaller than the diameter of the non-distal end portion.

In the manufacturing method according to the present invention, the diameter of the distal end portion of each of the plurality of pins used in the recess forming step is formed smaller than the diameter of the non-distal end portion, and therefore the recess having the above-described specific structure of the absorbent article can be formed with higher accuracy.

Therefore, the manufacturing method according to the present invention can easily obtain an absorbent article that can use the absorption region of the absorbent body to the maximum extent with higher accuracy and can exhibit excellent absorption efficiency.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, an absorbent article can be provided that can use the absorption region of the absorber to the maximum and has excellent absorption efficiency.

Drawings

Fig. 1 is a plan view of a sanitary napkin 1 according to an embodiment of the present invention, as viewed from a topsheet 2 side in a thickness direction T in an unfolded state.

Fig. 2 is a sectional view taken along line II-II of the sanitary napkin 1 of fig. 1.

Fig. 3 is an enlarged schematic view of a main part of the concave portion 6 of the sanitary napkin 1.

Fig. 4 is an enlarged schematic view of a main part of the sanitary napkin 1 in a case where the shape of the concave portion on the non-skin-facing surface side is different.

Fig. 5 is an enlarged schematic view of a main part of the concave portion 6 'of the sanitary napkin 1' according to another embodiment of the present invention.

Fig. 6 is a sectional view of a sanitary napkin 1 ″ according to still another embodiment of the present invention, corresponding to fig. 2.

Fig. 7 is a schematic view showing the cross-sectional shape of a pin used in the production of the absorbent article of the present invention.

Detailed Description

Hereinafter, preferred embodiments of the absorbent article of the present invention will be described in detail with reference to the drawings. In the present specification, unless otherwise specified, "a case where an object (for example, a sanitary napkin or the like) placed on a horizontal plane in a spread state is viewed from above in the vertical direction along the thickness direction of the object" is simply referred to as "in plan view".

(definitions of each)

As shown in fig. 1 and 2, a sanitary napkin 1 as one embodiment of an absorbent article of the present invention has a longitudinal direction L, a width direction W, and a thickness direction T that are orthogonal to each other, and further has a longitudinal center line C that passes through the center of the width direction W and extends in the longitudinal direction L_L(virtual line) and a width-direction center line C passing through the center of the longitudinal direction L and extending in the width direction W_W(phantom line).

In the present specification, the longitudinal direction L of the sanitary napkin 1 is relatively close to the width direction center line C_WIs referred to as the inner side in the longitudinal direction L, and is relatively distant from the center line C in the width direction_WThe one side of (b) is referred to as an outer side in the longitudinal direction L. Similarly, the center line C in the longitudinal direction is relatively close to the center line W in the width direction W of the sanitary napkin 1_LIs referred to as the inner side in the width direction W, and is relatively distant from the longitudinal center line C_LThe one side is referred to as an outer side in the width direction W.

In the present specification, any direction in a plane including the longitudinal direction L and the width direction W, which is perpendicular to the thickness direction T of the sanitary napkin 1 or a constituent member thereof (for example, a topsheet, a diffusion sheet, or the like), is referred to as a plane direction.

In the present specification, in the thickness direction T of the sanitary napkin 1, the side relatively close to the skin surface of the wearer when the sanitary napkin 1 is worn is referred to as the skin-facing surface side S1, and the side relatively distant from the skin surface of the wearer when the sanitary napkin 1 is worn is referred to as the non-skin-facing surface side S2.

The definitions of these terms are similarly applied to the constituent members of the sanitary napkin 1, the absorbent articles other than the sanitary napkin 1, and the constituent members thereof.

[ sanitary napkin for physiology ]

As shown in fig. 1, a sanitary napkin 1, which is one embodiment of the absorbent article of the present invention, has a vertically long shape that is long in the longitudinal direction L and short in the width direction W in a plan view, and is a predetermined vertically long shape in which both end edges in the longitudinal direction L protrude so as to draw a circular arc toward the outside in the longitudinal direction L.

The sanitary napkin 1 has a pair of wing portions FL and FL at the center in the longitudinal direction L, both ends in the width direction W of which protrude so as to form a substantially trapezoidal shape outward in the width direction W.

The shape of the sanitary napkin 1 is not limited to this shape, and may be a long shape having a length in the longitudinal direction L longer than a length in the width direction W, and may be any shape (for example, a rectangle, an ellipse, an hourglass shape, etc.) according to the state of use. The shape of the wing FL is not limited to the above-described substantially trapezoidal shape, and may be, for example, a semicircular shape or a semielliptical shape. The sanitary napkin 1 may not have such flaps FL.

As shown in fig. 2, the sanitary napkin 1 has, as a basic structure, a front sheet 2 made of nonwoven fabric forming the front surface of the skin-facing surface side S1 of the sanitary napkin 1, a back sheet 3 forming the front surface of the non-skin-facing surface side S2 of the sanitary napkin 1, and an absorbent member 4 positioned between the sheets in the thickness direction T.

As shown in fig. 1 and 2, the sanitary napkin 1 further includes: a diffusion sheet 5 disposed between the top sheet 2 and the absorber 4 in the thickness direction T; a pair of side sheets 9, 9 disposed at both ends in the width direction W of the sanitary napkin 1; and a plurality of adhesive sections AD arranged on the surface of the back sheet 3 on the non-skin-facing surface side S2 for fixing the sanitary napkin 1 to clothing (e.g., underwear) of a wearer.

The necessity or non-necessity of the constituent members such as the diffusion sheet, the pair of side sheets, and the adhesive section is determined according to the type, application, and the like of the absorbent article, and therefore, the absorbent article of the present invention is not necessarily provided with these constituent members.

In the sanitary napkin 1, as shown in fig. 2, both end portions in the width direction W of the front sheet 2 have a pair of loop portions each folded back in a loop shape toward the non-skin-facing surface side S2, and the inner end portions in the width direction W of each of the pair of side sheets 9, 9 are joined to the surface of the non-skin-facing surface side S2 of the loop portion.

As shown in fig. 1 to 3, the sanitary napkin 1 has a plurality of concave portions 6 in which the top sheet 2, the diffusion sheet 5, and the absorbent body 4 are all depressed toward the non-skin-facing surface side S2.

As shown in fig. 3, each of the plurality of concave portions 6 includes: an opening 61 formed by continuous cut surfaces of the front sheet 2; a diffusion sheet side opening 66 located on the non-skin-facing surface side S2 of the opening 61 and formed by continuous cut surfaces of the diffusion sheet 5; and an absorbent-side concave portion 62 which is located on the non-skin-facing surface side S2 of the diffuser-side opening 66, has a peripheral wall portion 63 and a bottom portion 64, and the bottom portion 64 has a convex portion 65 which protrudes toward the skin-facing surface side S1 of the sanitary napkin 1.

As described above, the plurality of concave portions 6 of the sanitary napkin 1 are each composed of at least the opening 61 and the absorbent-side concave portion 62, the opening 61 is formed by a continuous cut surface of the topsheet 2, and the absorbent-side concave portion 62 is positioned on the non-skin-facing surface side S2 of the opening 61 and has the peripheral wall portion 63 and the bottom portion 64, so that the topsheet 2 is completely opened in each concave portion 6 and the absorbent body 4 is exposed to the entire peripheral wall portion 63, and therefore, the excreta such as menstrual blood discharged from the wearer is likely to be uniformly transferred to the peripheral portion of the concave portion 6 via the peripheral wall portion 63.

Therefore, the sanitary napkin 1 can diffuse the excrement such as menstrual blood flowing into the concave portion 6 in the circumferential direction by the convex portion 65 formed in the bottom portion 64, and the diffused excrement can be uniformly transferred to the peripheral portion of the concave portion 6 via the peripheral wall portion 63, and as a result, the excrement can be uniformly absorbed in a wider area of the absorbent body 4.

Therefore, the sanitary napkin 1 can use the absorption region of the absorbent member 4 to the maximum extent, and can exhibit excellent absorption efficiency.

Further, since the diffusion sheet 5 is not an essential feature as described above, when the sanitary napkin 1 does not include the diffusion sheet 5, the concave portions 6 are formed by the opening 61 of the front sheet 2 and the absorber-side concave portions 62 located on the non-skin-facing surface side S2 of the opening 61.

Although not shown in fig. 3, in each concave portion 6, the front sheet 2 and the diffusion sheet 5 are cut continuously while slightly depressed toward the non-skin-facing surface side S2, and the opening 61 and the diffusion sheet side opening 66 are formed by the continuous cut surface.

Hereinafter, the various members constituting the sanitary napkin 1 will be described in more detail.

[ surface sheet ]

In the sanitary napkin 1 described above, as shown in fig. 1, the topsheet 2 has a vertically long shape extending in the longitudinal direction L in a range from the front longitudinal end to the rear longitudinal end of the sanitary napkin 1 in a plan view. As shown in fig. 2, the top sheet 2 is formed of a liquid-permeable nonwoven fabric that is disposed at a position on the skin-facing surface side S1 in the thickness direction T of the sanitary napkin 1 and forms a contact surface that can come into contact with the skin of the wearer (i.e., the surface of the skin-facing surface side S1 of the sanitary napkin 1).

In the present specification, in the longitudinal direction L of the sanitary napkin 1, the side which becomes the side relatively close to the abdomen of the wearer when the sanitary napkin 1 is worn is referred to as the front side, and the other side which becomes the side relatively distant from the abdomen of the wearer is referred to as the rear side. In association with this, as shown in fig. 1, the sanitary napkin 1 has a front side region a in the longitudinal direction L_FCentral area A_CAnd a posterior region A_B。

As shown in fig. 2, the front sheet 2 has a slightly larger shape in the width direction W than the diffusion sheet 5 and the absorber 4 positioned on the non-skin-facing surface side S2 of the front sheet 2, and the front sheet 2 has a pair of loop portions formed by folding back toward the non-skin-facing surface side S2 at both ends in the width direction W. Both end portions of the folded-back front sheet 2 are sandwiched between the diffusion sheet 5 and the pair of side sheets 9, and are joined to a pair of inner end portions of the pair of side sheets 9, 9 facing each other via a pair of adhesive portions (not shown) intermittently or continuously extending in the longitudinal direction L.

As shown in fig. 2, both ends of the diffusion sheet 5 in the width direction W, which are disposed on the non-skin-facing surface side S2 of the front sheet 2, are located inside the loop portion of the front sheet 2.

The nonwoven fabric used as the top sheet is not particularly limited as long as it has various properties (for example, liquid permeability, skin touch, flexibility, strength, and the like) that can be used as the top sheet of the sanitary napkin, and any nonwoven fabric such as a hot air nonwoven fabric, a spunlace nonwoven fabric, a spunbond nonwoven fabric, and a point-bond nonwoven fabric can be used.

The type of fibers constituting the nonwoven fabric is not particularly limited, and examples thereof include cellulose fibers; hydrophilic fibers such as thermoplastic resin fibers, e.g., olefin-based resins and polyester-based resins, which have been subjected to hydrophilization treatment, may be used alone or in combination of two or more types.

Examples of the cellulose fibers that can be used as the constituent fibers of the nonwoven fabric include natural cellulose fibers (plant fibers such as cotton), regenerated cellulose fibers, purified cellulose fibers, and semi-synthetic cellulose fibers.

On the other hand, as the thermoplastic resin fibers that can be used as the constituent fibers of the nonwoven fabric, there can be mentioned, for example, fibers made of known thermoplastic resins such as olefin resins such as Polyethylene (PE) and polypropylene (PP), polyester resins such as polyethylene terephthalate (PET), and polyamide resins such as 6-nylon, and these resins can be used alone or in combination of two or more kinds of resins. If the nonwoven fabric contains such thermoplastic resin fibers, the strength of the topsheet is high, and therefore, even when the topsheet is subjected to physical pressure of the wearer or the like, the openings are less likely to be crushed, and the functional effect of the depressions can be more reliably exhibited.

The form of the thermoplastic resin fiber is not particularly limited, and examples thereof include sheath-core type composite fibers such as PET (core)/PE (sheath), PP (core)/PE (sheath), side-by-side type composite fibers, sea-island type composite fibers, and the like; flat, letter-Y-shaped, letter-C-shaped, and the like; a latent crimp or visually crimped three-dimensional crimped fiber; split fibers that are split by physical load such as water flow, heat, embossing, and the like may be used alone or two or more types of fibers may be used together.

Among the above-mentioned various fibers, the constituent fibers of the nonwoven fabric used as the surface sheet are preferably water-retentive fibers such as natural cellulose fibers, and more preferably cotton. Since water-retentive fibers such as cotton easily absorb and retain liquid such as water and the fiber length is relatively long, if such fibers are used as the constituent fibers of a nonwoven fabric, the water-retentive fibers are arranged so as to span between adjacent concave portions, the liquid transferability between the concave portions is improved, and the liquid diffusibility in the surface direction of the top sheet is improved, so that it is possible to uniformly absorb excrement in a wider area of the absorbent body as a result.

The specific average fiber length of the water-retentive fibers is not particularly limited, and is, for example, in the range of 5mm to 80mm, preferably in the range of 10mm to 60 mm.

Further, if the constituent fibers of the nonwoven fabric are organic cotton having excellent flexibility, texture, and the like, the nonwoven fabric has the following advantages: the top sheet can easily ensure good flexibility, texture, and the like, can realize more excellent skin touch, and can create a feeling of reassurance for the wearer by using natural materials for the top sheet.

The Organic cotton is certified by gots (global Organic Textile standard).

The various fibers described above that can be used as the constituent fibers of the nonwoven fabric may be used individually or in combination of two or more types.

The structure of the nonwoven fabric used as the top sheet is not particularly limited as long as it has the opening of the above-described concave portion, and may have a flat sheet-like structure or a predetermined uneven structure (for example, an uneven structure having a waveform in cross section or a ridge-and-furrow structure) that can achieve liquid diffusion in addition to the opening of the above-described concave portion. When the nonwoven fabric has such a concavo-convex structure, the plurality of convex portions in the concavo-convex structure may have a solid internal structure or may have a hollow internal structure.

The shape, various dimensions, basis weight, and the like of the top sheet are not particularly limited as long as the top sheet can be used as an absorbent article, and any shape, various dimensions, basis weight, and the like can be adopted according to the desired liquid permeability, skin touch, flexibility, strength, and the like. For example, the thickness of the surface sheet is in the range of 0.001mm to 5.0mm, preferably in the range of 0.01mm to 3.0mm, and the weight per unit area of the surface sheet is 5g/m²～100g/m²In the range of (1), preferably 6g/m²～50g/m²Weight per unit area in the range of (a).

The top sheet may be composed of a single-layer nonwoven fabric, or may be composed of two or more layers of a multilayer nonwoven fabric.

In the sanitary napkin 1, the front sheet 2 is bonded to the diffusion sheet 5 with an adhesive such as a hot-melt adhesive, and the diffusion sheet 5 and the portions of the pair of side sheets 9 and 9 that face the absorbent body 4 are bonded to the absorbent body 4 with an adhesive. The portions of the pair of side sheets 9 and the absorbent body 4 facing the back sheet 3 are joined to the back sheet 3 with an adhesive.

Further, the surface sheet may not have the pair of ring portions described above, but if the surface sheet has such a pair of ring portions, there are advantages as follows: the absorbent article can flexibly receive the force received from the wearer's thighs by the cushioning effect of the pair of loop portions, and therefore can make the feel to the wearer more favorable.

[ Back sheet ]

In the sanitary napkin 1 described above, the back sheet 3 has a vertically long shape extending in the longitudinal direction L in a range from the front longitudinal end to the rear longitudinal end of the sanitary napkin 1 in a plan view and extending in the width direction W in a range from one width end to the other width end in the width direction W of the sanitary napkin 1. As shown in fig. 2, the back sheet 3 is disposed at a position on the non-skin-facing surface side S2 in the thickness direction T of the sanitary napkin 1, and is formed of a liquid-impermeable sheet-like member that prevents excreta such as menstrual blood that has passed through the absorbent body 4 from leaking to the outside of the sanitary napkin 1.

The liquid-impermeable sheet-like member used as the back sheet is not particularly limited as long as it can prevent permeation of excreta such as menstrual blood discharged from the wearer, and for example, a hydrophobic nonwoven fabric formed of hydrophobic thermoplastic resin fibers (for example, various conjugate fibers such as polyolefin resin fibers, polyester resin fibers, sheath-core conjugate fibers, and the like) can be used; a porous or nonporous resin film formed of a hydrophobic thermoplastic resin such as PE or PP; a laminate obtained by bonding a nonwoven fabric to the resin film; a known liquid impermeable sheet member such as an SMS nonwoven fabric is laminated.

The shape, various sizes, weight per unit area, and the like of the back sheet are not particularly limited as long as the back sheet can be used as a back sheet of an absorbent article, and any shape, various sizes, weight per unit area, and the like can be adopted according to the desired leakage-proof performance, air permeability, strength, and the like.

[ absorbent body ]

In the sanitary napkin 1, as shown in fig. 1, the absorbent body 4 has a longitudinal shape in plan view as follows: which extend over a wide range in the longitudinal direction L and the width direction W, respectively, so as to straddle the longitudinal center line C of the sanitary napkin 1_LAnd a width direction center line C_WAnd the longitudinal ends of both the front and rear sides thereof are projected so as to draw an arc toward the outer side in the longitudinal direction L. As shown in fig. 2, the absorbent member 4 is disposed between the front sheet 2 and the back sheet 3 (more specifically, between the diffusion sheet 5 and the back sheet 3) in the thickness direction T of the sanitary napkin 1, and is capable of absorbing and retaining the light transmitted through the front sheet 2 and the back sheet 3A predetermined water-absorbing member for excreta such as the sheet 2.

As shown in fig. 1, the sanitary napkin 1 has an excretory opening corresponding region XA located at a position slightly forward of the center portion in the longitudinal direction L and at a position in the center portion in the width direction W, which is opposite to or in contact with the excretory opening of the wearer, in a plan view, and the absorbent body 4 is disposed at least in a region covering a wide range of the excretory opening corresponding region XA.

Here, the excretory opening corresponding region refers to a region that faces or comes into contact with the excretory opening of the wearer when the absorbent article is worn, and is generally set according to the type and use of the absorbent article. The excretory opening corresponding region is set to have a length of about 1/4 to 1/2 of the total length of the absorbent body in the longitudinal direction at a position slightly forward of the center portion in the longitudinal direction of the absorbent body, and to have a width of about 1/2 to 1/3 of the total length of the absorbent body in the width direction at a position substantially in the center portion in the width direction of the absorbent body. In addition, when the wing portions are provided as in a sanitary napkin for personal use, the region corresponding to the excretion portion is generally set so as to overlap with the wing portions in the width direction, and for example, the region corresponding to the excretion portion is set so that the center position in the longitudinal direction of the region corresponding to the excretion portion substantially overlaps with the center position in the longitudinal direction of the wing portions in the width direction.

The water-absorbent member used as the absorbent body is not particularly limited as long as it can absorb and hold at least excreta such as menstrual blood, and any water-absorbent member known in the art can be used. As an example of such a water-absorbent member, there is a member in which at least one absorbent core made of a predetermined water-absorbent material is covered with a core wrap sheet such as a hydrophilic tissue paper. Examples of the water-absorbent material constituting the absorbent core include hydrophilic fibers, high-absorbent polymers, and the like, and more specifically, cellulose fibers such as ground pulp, cotton, rayon, and acetate fibers; a granular material comprising a high-absorbency polymer such as a sodium acrylate copolymer; and a mixture obtained by arbitrarily combining these.

In the sanitary napkin 1, the absorbent core 4 is composed of an absorbent core (not shown) and a core wrap sheet (not shown) covering the absorbent core, and the absorbent core is composed of a water-absorbent material.

When the nonwoven fabric forming the top sheet contains a cellulose fiber (preferably cotton), the absorbent body also preferably contains a cellulose fiber (preferably cotton). In this case, it is preferable that a part of the cellulose-based fibers contained in the topsheet and the cellulose-based fibers contained in the absorbent body are in direct or indirect communication. If the absorbent article has such a structure, the cellulose-based fibers having high liquid diffusibility are easily communicated through the topsheet (and further through the diffusion sheet depending on the case) to the absorbent body, and therefore, the liquid diffusion of the excrement by the cellulose-based fibers can be utilized to easily transfer the excrement from the topsheet to the absorbent body, and as a result, the absorption performance can be further improved.

The absorbent material may contain synthetic fibers such as thermoplastic resin fibers as long as the absorption performance is not impaired. If the absorbent body contains such synthetic fibers, the strength of the absorbent body can be increased by the construction of the fiber network structure by the synthetic fibers, and therefore, even when the body pressure of the wearer or the like is applied to the absorbent body, the absorbent body-side concave portions are not easily deformed by pressure, and the operational effects of the concave portions can be more reliably exhibited.

The shape, various sizes, basis weight, and the like of the absorbent body are not particularly limited as long as the absorbent body can be used as an absorbent body of an absorbent article, and any shape (for example, a rectangular shape, an oval shape, an hourglass shape, and the like), various sizes, basis weight, and the like can be adopted according to desired absorption performance, flexibility, strength, and the like.

[ diffusion sheet ]

In the sanitary napkin 1 described above, the diffusion sheet 5 has a vertically long shape extending in the longitudinal direction L in a range from the front longitudinal end to the rear longitudinal end of the sanitary napkin 1 in a plan view. As shown in fig. 2, the diffusion sheet 5 is disposed between the top sheet 2 and the absorbent body 4 in the thickness direction T of the sanitary napkin 1, and is composed of a sheet-like member having predetermined liquid diffusibility and liquid permeability, which is capable of diffusing excrement that has passed through the top sheet 2 in the planar direction and transferring the excrement to the absorbent body 4 on the non-skin-facing surface side S2.

The sheet-like member used as the diffusion sheet is not particularly limited as long as it has predetermined liquid diffusibility and liquid permeability, and examples thereof include known nonwoven fabrics and woven fabrics having liquid diffusibility and liquid permeability, and composite sheets obtained by laminating them.

In the sanitary napkin 1, as shown in fig. 2, the diffusion sheet 5 has a slightly smaller shape in the width direction W than the front sheet 2, and both ends in the width direction W are sandwiched between both ends of the front sheet 2 folded back in the thickness direction T in the ring portion of the front sheet 2.

When the surface sheet contains cellulose fibers (preferably, cotton fibers), the diffusion sheet also preferably contains cellulose fibers (preferably, cotton fibers). In this case, it is preferable that a part of the cellulose-based fibers contained in the surface sheet and the cellulose-based fibers contained in the diffusion sheet are directly or indirectly in communication, and it is more preferable that a part of the cellulose-based fibers contained in the diffusion sheet and the cellulose-based fibers contained in the absorbent body are directly or indirectly in communication. If the absorbent article has such a structure, the cellulose-based fibers having high liquid diffusibility are easily communicated from the topsheet to the absorbent body through the diffusion sheet, and therefore, the liquid diffusion of the excrement by the cellulose-based fibers can be utilized to easily transfer the excrement from the topsheet to the absorbent body through the diffusion sheet, and as a result, the absorption performance can be further improved.

In this case, for example, a nonwoven fabric or the like made of thermoplastic resin fibers can be used as the diffusion sheet.

The diffusion sheet may have a fiber density higher than that of the surface sheet. If the diffusion sheet and the surface sheet have such a relationship in fiber density, the excrement that has passed through the surface sheet is easily transferred to the diffusion sheet by the capillary phenomenon, and therefore, the absorption performance can be further improved.

The shape, various sizes, unit area weight, and the like of the diffusion sheet 5 are not particularly limited as long as they have predetermined liquid diffusibility and liquid permeability, and any shape, various sizes, unit area weight, and the like can be adopted according to desired absorption performance, flexibility, and the like.

[ side sheet ]

In the sanitary napkin 1 described above, as shown in fig. 1, the pair of side sheets 9, 9 have a pair of strip-like shapes extending in the longitudinal direction L at both end portions in the width direction W of the sanitary napkin 1 in a plan view. The pair of side sheets 9, 9 are positioned on the non-skin-facing surface side S2 of the top sheet 2 at both ends in the width direction W of the sanitary napkin 1, and are formed of hydrophilic or water-repellent sheet-like members that function as follows: the menstrual blood and other excrement supplied to the surface of the skin-facing surface side S1 of the topsheet 2 is prevented from leaking to the outside in the width direction W of the sanitary napkin 1 and is spread in the longitudinal direction L by being blocked.

The arrangement form of the pair of side sheets 9, 9 is not particularly limited, and for example, both end portions of the pair of side sheets 9, 9 in the width direction W of the sanitary napkin 1 may be positioned on the skin-facing surface side S1 of the top sheet 2.

The hydrophilic or water-repellent sheet-like member used as the side sheet is not particularly limited as long as it can function as a side sheet of the absorbent article, and examples thereof include a nonwoven fabric made of hydrophilic or water-repellent fibers, a nonwoven fabric subjected to hydrophilization treatment or water-repellent treatment, and a synthetic resin film having air permeability.

The shape, the various sizes, the weight per unit area, and the like of each of the pair of side sheets may be used as the side sheet of the absorbent article, and any shape, various sizes, the weight per unit area, and the like according to the desired leakage preventing performance, absorption performance, and the like may be used without particular limitation.

[ concave part ]

In the sanitary napkin 1 described above, as shown in fig. 1, the plurality of concave portions 6 are disposed at positions slightly forward of the central portion in the longitudinal direction L of the sanitary napkin 1 and at positions of the central portion in the width direction W in a plan view. An area where the plurality of recesses 6 are formed is referred to as a recess forming area XB.

Further, as shown in fig. 1, the recess forming region XB means a rectangular region surrounded by two imaginary lines passing through the lengthwise direction outer end edges of the recesses located on the foremost side and the rearmost side in the lengthwise direction L and extending in the widthwise direction W, and two imaginary lines passing through the widthwise direction outer end edges of the recesses located on the one side outermost end side and the other side outermost end side in the widthwise direction W and extending in the lengthwise direction L.

In the sanitary napkin 1, as shown in fig. 1, the excretion portion corresponding region XA overlaps the concave portion formation region XB in a plan view. If the excretory opening corresponding region XA and the recessed portion formation region XB are overlapped in this manner, the excretory substance discharged from the wearer can flow into the plurality of recessed portions 6 more efficiently.

In the sanitary napkin 1, the plurality of concave portions 6 are arranged in the concave portion forming region XB in a staggered manner (staggered arrangement) so that the concave portions 6 are not adjacent to each other in the longitudinal direction L and the width direction W, but the arrangement form of the plurality of concave portions is not particularly limited in the present invention, and for example, the plurality of concave portions may be arranged in any form such as a lattice-like arrangement form in which the concave portions are uniformly arranged in the longitudinal direction and the width direction, an arrangement form in which a predetermined pattern or the like (for example, a circular shape, a heart shape, or the like) is formed as a whole, or a random (irregular) arrangement form.

The arrangement interval of the plurality of concave portions is not particularly limited, and for example, an arrangement interval in the range of 1mm to 30mm can be adopted as the arrangement interval in each of the longitudinal direction and the width direction. The arrangement interval may be the same or different in the longitudinal direction and the width direction.

In addition, in the sanitary napkin 1 described above, each of the plurality of concave portions 6 is formed so as to recess the front sheet 2, the diffusion sheet 5, and the absorbent body 4 toward the non-skin-facing surface side S2, and includes: an opening 61 formed by continuous cut surfaces of the front sheet 2; a diffusion sheet side opening 66 located on the non-skin-facing surface side S2 of the opening 61 and formed by continuous cut surfaces of the diffusion sheet 5; and an absorbent body side concave portion 62 which is located on the non-skin-facing surface side S2 of the diffuser side opening portion 66 and has a peripheral wall portion 63 and a bottom portion 64.

The bottom portion 64 is formed with a convex portion 65 that protrudes toward the skin-facing surface side S1 of the sanitary napkin 1.

(opening part)

In the sanitary napkin 1 described above, the opening 61 of the concave portion 6 is formed by a cut surface obtained by slightly recessing the topsheet 2 toward the non-skin-facing surface side S2 and continuously cutting the same.

The diffusion sheet side opening 66 is also formed by a cut surface obtained by slightly recessing the diffusion sheet 5 toward the non-skin-facing surface side S2 and continuously cutting the same.

If the configuration is such that the topsheet 2 and the diffusion sheet 5 are completely opened and the absorbent body 4 is exposed to the entire peripheral wall portion 63, the excreta such as menstrual blood discharged from the wearer is likely to be uniformly transferred to the peripheral portion of the concave portion 6 via the peripheral wall portion 63.

In particular, in the sanitary napkin 1 described above, since the diffusion sheet 5 is provided between the topsheet 2 and the absorbent body 4 and the plurality of concave portions 6 each have the diffusion sheet side opening 66 formed by a continuous cut surface of the diffusion sheet 5 between the opening 61 formed by the topsheet 2 and the absorbent body side concave portion 62, the excrement supplied between the plurality of concave portions 6 and having passed through the topsheet 2 can be diffused in the planar direction by the diffusion sheet 5 or the excrement flowing into the concave portions 6 can be diffused in the planar direction from the diffusion sheet side opening 66 by the diffusion sheet 5. Thus, the sanitary napkin 1 can uniformly absorb excrement in a wider area of the absorbent body 4.

In the absorbent article of the present invention, since the diffusion sheet is not an essential feature, when the absorbent article does not include the diffusion sheet, the plurality of concave portions do not have the diffusion sheet side opening portions.

In the sanitary napkin 1 described above, the openings 61 of the plurality of concave portions 6 have a circular shape in plan view, but the shape of the openings of the concave portions in the present invention is not particularly limited, and any planar shape such as a circle, an ellipse, a polygon having a triangle or more, a star, a heart, or the like can be used. Further, if the shape of the opening of the concave portion is a shape having a design feeling such as a star shape or a heart shape, it is possible to make uneasy feeling or the like caused by the case where a plurality of concave portions are formed in the absorbent article difficult to occur, and it is also possible to create a design having an integrated feeling together with the shape of a compressed portion formed by embossing or the like described later.

(concave part of absorber side)

In the sanitary napkin 1, as shown in fig. 3, the absorbent-side concave portion 62 of the concave portion 6 is a bottomed concave portion formed by recessing the surface of the skin-facing surface side S1 of the absorbent body 4 toward the non-skin-facing surface side S2 at the opening 61 of the topsheet 2 and the non-skin-facing surface side S2 of the diffuser-side opening 66, and has a peripheral wall portion 63 connected to the diffuser-side opening 66 and a bottom portion 64 connected to the non-skin-facing surface side S2 of the peripheral wall portion 63.

In addition, the bottom 64 of the absorbent-body-side concave portion 62 is formed with a convex portion 65 protruding toward the skin-facing surface side S1 of the sanitary napkin 1, and the convex portion 65 can diffuse the excreta such as menstrual blood that has flowed into the concave portion 6 in the circumferential direction. The excrement diffused in this way is uniformly transferred to the peripheral portion of the concave portion 6 via the peripheral wall portion 63, and as a result, the excrement can be uniformly absorbed in a wider area of the absorbent body 4.

The peripheral wall 63, the bottom 64, and the projections 65 of the absorbent body-side concave portion 62 are all formed by the absorbent body 4, and therefore have predetermined absorption performance.

In the sanitary napkin 1, at least some of the plurality of concave portions 6 have the void portions 7, which are low fiber density portions having a relatively low fiber density, and the void portions 7 extend over the entire circumference of the peripheral wall portion 63 at the end portion of the peripheral wall portion 63 on the side closer to the bottom portion 64. Such a low fiber density portion has a relatively low fiber density (i.e., smaller than the other portions of the peripheral wall portion 63) and absorbs excrement relatively easily, and therefore excrement flowing down toward the bottom portion 64 or excrement spreading by the convex portions 65 can be quickly and uniformly transferred into the absorbent body 4 via the low fiber density portion of the peripheral wall portion 63.

In the sanitary napkin 1, as shown in fig. 3, the low fiber density portion is formed by the void portion 7 extending in the direction away from the recessed portion 6, and therefore, the following advantages are obtained: the excrement flowing down toward the bottom portion 64 or the excrement spreading by the convex portion 65 can be more quickly and uniformly transferred into the absorbent body 4 through the void portion 7 of the peripheral wall portion 63.

In the sanitary napkin 1, as shown in fig. 3, the bottom portion 64 of the concave portion 6 has a central bottom central portion 64C and a peripheral bottom portion 64S adjacent to the periphery of the central bottom portion 64C in a plan view, and the convex portion 65 has a top portion 65T in the central bottom portion 64C. If the top portion 65T of the convex portion 65 is positioned at the bottom center portion 64C in this manner, the excrement flowing into the concave portion 6 can be spread more uniformly in the circumferential direction at the convex portion 65, and thus the excrement can be transferred more uniformly to the peripheral portion of the concave portion 6.

The position of the top portion 65T of the convex portion 65 is not limited to the bottom central portion 64C, and the top portion 65T of the convex portion 65 may be located in the bottom peripheral portion 64S, for example, when the direction of diffusion of excrement is shifted.

The shape of the convex portion 65 is not particularly limited, and the convex portion 65 may have any shape such as a substantially conical shape, a substantially hemispherical shape, a substantially pyramid shape, or a substantially truncated cone shape.

In the sanitary napkin 1, as shown in fig. 3, the fiber density of the bottom peripheral portion 64S is higher than that of the bottom central portion 64C. If the fiber density of the bottom peripheral portion 64S is made higher than the fiber density of the bottom central portion 64C in this manner, the excrement flowing into the concave portion 6 is easily drawn into the bottom peripheral portion 64S by the capillary phenomenon, and therefore the excrement reaching the convex portion 65 can be diffused more reliably in the peripheral direction.

In the present specification, the fiber density (for example, the fiber density of the low fiber density portion of the peripheral wall portion, the fiber density of each portion of the bottom portion, and the like) can be measured by the following measurement method.

(1) The sample such as an absorber is completely frozen by liquid nitrogen, and the sample is cut in the thickness direction so as to include a measurement target portion of the fiber density.

(2) The cut surface parallel to the thickness direction of the sample was observed under magnification using a scanning electron microscope (JCM-5100, manufactured by Nippon electronics Co., Ltd.). The observation magnification is a magnification (for example, 50 to 500 times) at which the cut surface of 30 to 60 fibers can be measured in one screen.

(3) The number of cut sections of the fibers in the observation area is measured. That is, the number of cut sections of the cut fiber corresponding to a predetermined area of the cut section of the sample is counted.

(4) The number of cut surfaces of the obtained fibers was converted to 1mm per unit²The number of cut surfaces of the fibers (2) and the fiber density (root/mm) of the fibers (3)²). Further, measurement was performed at any three positions, and the average of the measured values was 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, the number of fibers per unit area on a cut surface parallel to the thickness direction is used as the fiber density.

In addition, 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 X-ray CT analysis, for example. The values of fiber density differ for fiber density per unit area and fiber density per unit volume, but are the same in the relative comparisons of fiber density (e.g., comparison of size) between various sections.

In the sanitary napkin 1 described above, as shown in fig. 3, the surface of the skin-facing surface side S1 of the bottom 64 of the concave portion 6 is formed by the compressed matter 67 of the surface sheet 2 which is cut out from the surface sheet 2 and compressed in the thickness direction T when the concave portion 6 is formed, and the non-skin-facing surface side S2 of the compressed matter 67 of the surface sheet 2 includes the compressed matter 68 of the diffusion sheet 5 which is cut out from the diffusion sheet 5 and compressed in the thickness direction T when the concave portion 6 is formed, a compressed matter (not shown) of the core wrap sheet surrounding the absorbent core of the absorbent body 4, and a compressed matter (not shown) of the absorbent core.

In the sanitary napkin 1, the diffusion sheet 5 and the core wrap sheet may be colored separately, or only the peripheral edge portion of the bottom portion 64, the opening portion 61, and the diffusion sheet side opening portion 66 may be colored, or these portions may be colored relatively more heavily than other portions. If the constituent members and various portions of the recessed portion 6 are colored in this way, the wearer can easily recognize the presence of the recessed portion 6, and therefore, the following advantages are obtained: when the sanitary napkin 1 is worn by a wearer, the concave portion forming region XB in which the plurality of concave portions 6 are formed can be located at an appropriate position and can be easily worn.

The sanitary napkin 1 may contain any functional agent such as a blood viscosity reducing agent and a hydrophilic oil agent on the inner surface of the concave portion 6 (for example, the surfaces of the opening 61, the diffusion sheet side opening 66, the peripheral wall 63, and the bottom portion 64).

In particular, in the present invention, it is preferable that a hydrophilic oil agent different from the hydrophilic oil agent used for the nonwoven fabric (for example, spunbond nonwoven fabric, through-air nonwoven fabric, etc.) forming the surface sheet is adhered to the inner surface of the concave portion. That is, the inner surface of the recess is preferably relatively more hydrophilic than the peripheral portion of the recess.

Since the hydrophilicity of the peripheral portion of the concave portion is relatively low, the excrement in the peripheral portion easily flows down into the concave portion (that is, the slipping-off property of the excrement into the concave portion becomes high), and since the hydrophilicity of the inner surface of the concave portion is relatively high, the excrement flowing down into the concave portion easily migrates to the absorbent body (that is, the drawing-in property into the absorbent body becomes high).

In addition, in order to achieve such an effect, the same effect as that obtained when the same hydrophilic oil agent as that used for the nonwoven fabric forming the surface sheet is attached to the inner surface of the recessed portion at a higher concentration than the surface sheet can be obtained.

In addition, in the case where a hydrophilic oil agent is not used for the nonwoven fabric forming the surface sheet, the same effect as described above can be obtained by adhering the hydrophilic oil agent to the inner surface of the concave portion.

The method of adhering the hydrophilic oil agent to the inner surface of the concave portion is not particularly limited, and for example, the hydrophilic oil agent may be applied to the inner surface of the concave portion after the concave portion is formed, or a pin for forming the concave portion having the hydrophilic oil agent adhered at least to the tip portion may be used when the concave portion is formed.

When the hydrophilic oil agent is attached to the inner surface of the concave portion, it is preferable that the hydrophilic oil agent is attached to a position closer to the bottom peripheral portion than the bottom center portion of the concave portion. By attaching the hydrophilic oil agent in this manner, the above-described effect by the capillary phenomenon at the bottom peripheral portion can be more easily obtained.

As shown in fig. 3, the sanitary napkin 1 has a plurality of non-skin-facing surface-side concave portions 8 that are recessed from the surface of the non-skin-facing surface side S2 of the absorbent body 4 toward the skin-facing surface side S1 at positions corresponding to the plurality of concave portions 6 in the thickness direction T. By providing the plurality of non-skin-facing side depressed portions 8, the sanitary napkin 1 described above can be easily folded with the bottom portion 64 sandwiched between the depressed portions 6 and the non-skin-facing side depressed portions 8 as a base point, and the depressed portion forming region XB in which the plurality of depressed portions 6 are formed can be easily deformed to conform to the shape of the wearer's crotch when worn. Thus, the sanitary napkin 1 described above can easily bring the concave portion forming region XB into contact with the skin of the wearer when worn, and can exhibit more excellent absorption efficiency.

In the sanitary napkin 1 described above, the non-skin-facing surface-side concave portion 8 has a substantially flat structure as shown in fig. 3, but the structure of the non-skin-facing surface-side concave portion in the present invention is not limited to such a configuration, and the non-skin-facing surface-side concave portion may have a convex structure in which the surface of the non-skin-facing surface side S2 of the bottom center portion 64C protrudes toward the non-skin-facing surface side S2, for example, as in the non-skin-facing surface-side concave portion 8' shown in fig. 4. If the non-skin-facing surface side recessed portion 8' has such a convex structure, it is easy to bend the bottom portion 64 from the bottom portion peripheral portion 64S of the bottom portion 64, and therefore, the following advantages are obtained: when worn, the recessed portion forming region XB in which the plurality of recessed portions 6 are formed is easily deformed to match the shape of the wearer's crotch, and the structure of the raised portions 65 at the bottom portion 64 described above is easily maintained (i.e., the effect of the raised portions 65 can be more reliably exhibited).

In the sanitary napkin 1 described above, the plurality of concave portions 6 each have a structure in which the opening area from the opening 61 to the bottom 64 is substantially constant, but the structure of the concave portions is not limited to the above-described one in the present invention, and the opening area of the opening 61 ' of the top sheet 2 may be formed smaller than the opening area of the end 63T ' on the side closer to the bottom 64 ' of the peripheral wall 63 ' of the absorbent-side concave portion 62 ', for example, as in the concave portion 6 ' of the sanitary napkin 1 ' according to another embodiment of the present invention shown in fig. 5.

In the sanitary napkin 1 ', as shown in fig. 5, the opening area of the opening 61 ' of the topsheet 2 is smaller than the opening area of the diffuser-side opening 66 ', and the opening area of the diffuser-side opening 66 ' is smaller than the opening area of the end 63T ' of the peripheral wall 63 ' on the side closer to the bottom 64 '.

In the sanitary napkin 1 ', the opening area of the opening 61' of the concave portion 6 'is formed smaller than the opening area of the end portion 63T' of the side of the peripheral wall portion 63 'closer to the bottom portion 64', and therefore, the excrement can be easily and uniformly absorbed in a wider area of the absorbent body 4, and the excrement absorbed by the absorbent body 4 can be less likely to flow back to the surface of the skin-facing surface side S1 of the sanitary napkin 1 'through the concave portion 6'.

In the sanitary napkin 1 ″ according to the further embodiment of the present invention, as shown in fig. 6, the absorbent body 4 'has the central protrusion 4H' having a relatively large thickness at the portion overlapping the concave portion forming region XB in the thickness direction T. If the central protrusion 4H ' is formed in the portion of the absorbent body 4 ' overlapping the concave portion forming region XB in this manner, the concave portion forming region XB overlapping the central protrusion 4H ' is easily attached to the crotch of the wearer during wearing, and the excrement discharged from the wearer can more reliably flow into the plurality of concave portions 6.

(compressing section)

The absorbent article of the present invention may have one or more compressed parts depressed in the thickness direction from the surface of the skin-facing surface side of the topsheet for the purpose of diffusing excrement supplied to the topsheet in a predetermined direction (for example, the longitudinal direction) or easily bending the absorbent article into a predetermined shape.

For example, the sanitary napkin 1 described above, as shown in fig. 1, has, in plan view: a pair of compressed parts 12, 12 located on both outer sides in the width direction W with respect to the drain opening corresponding region XA (i.e., with respect to the recess forming region XB) and extending continuously or intermittently in the length direction L; a pair of compressing portions 13, 13 located on the rear side in the longitudinal direction L of each of the pair of compressing portions 12, 12 and extending in the longitudinal direction L; and compression portions 11, 14 located respectively on the front side and the rear side in the longitudinal direction L with respect to the excretion portion corresponding region XA and having a heart-shaped annular shape.

The compressed parts 11 to 14 are formed by compressing the topsheet 2, the diffusion sheet 5, and the absorbent member 4 together in the thickness direction T by a processing method such as embossing. Therefore, the front sheet 2, the diffusion sheet 5, and the absorber 4 are compressed in the thickness direction T to form the bottoms of the compressed parts 11 to 14.

Further, as shown in fig. 2, the compression units 11 to 14 include: a low-density portion that is less compressed, and thus has a relatively low fiber density and a shallow depth from the surface of the skin-facing surface side S1 of the surface sheet 2; and a high-density portion that is compressed strongly, so that the surface of the skin-facing surface side S1 of the top sheet 2 has a relatively high fiber density and a deep depth. As shown in fig. 2, the low-density portion and the high-density portion form a bottom portion at a shallow depth position and a bottom portion at a deep depth position of each of the compressed portions 11 to 14.

In the present invention, the shape of the compressed portion in a plan view is not particularly limited, and any shape (for example, a curved shape, a linear shape, a predetermined design shape, or the like) corresponding to desired liquid diffusibility, deformation conductivity, strength, or the like can be adopted.

In the present invention, the absorbent article does not necessarily have such a compressed portion, but preferably has a pair of compressed portions extending in the longitudinal direction at least on the outer sides in the width direction of the concave portion forming region. In the sanitary napkin 1 described above, since the pair of compressed portions 12, 12 extending in the longitudinal direction L are provided on the outer side in the width direction W of the recessed portion forming region XB, the pair of compressed portions 12, 12 serve as bending base points, and are easily deformed so that the cross-sectional shape of the sanitary napkin 1 in the width direction W becomes substantially a letter W. Thus, when the sanitary napkin 1 is worn, the depressed portion forming region XB located between the pair of compressed portions 12, 12 is easily brought into contact with the crotch of the wearer, and the excrement discharged from the wearer can more reliably flow into the plurality of depressed portions 6.

[ production method ]

Next, a method for manufacturing an absorbent article of the present invention will be described by way of example using the method for manufacturing a sanitary napkin 1 described above.

The sanitary napkin 1 can be obtained by the same production method as the conventional sanitary napkin except for the step of forming the plurality of concave portions 6 (concave portion forming step).

That is, the sanitary napkin 1 can be obtained by a manufacturing method including at least the following steps:

(1) a first laminating step of bonding a nonwoven fabric for a surface sheet and a sheet-like member for a diffusion sheet with a hot-melt adhesive;

(2) a loop forming step of forming a pair of loops at both end portions in the width direction (CD direction) of the laminated sheet obtained in the 1 st laminating step using a predetermined folding tool (e.g., a guide plate (gauge; japanese: セーラー), etc.);

(3) a 2 nd laminating step of bonding the laminated sheet having the pair of loop portions formed thereon, the pair of continuous sheets for the side sheets, and the absorbent body 4 with a hot-melt adhesive;

(4) a compressed part forming step of feeding the laminate obtained in the 2 nd laminating step to a compressing device in which an embossing roll having a predetermined convex part and an anvil roll are arranged to face each other, compressing the laminate from the surface sheet nonwoven fabric side, and forming predetermined compressed parts 11 to 14 in the laminate;

(5) a recess forming step of supplying the laminate to a recess forming processing device in which a processing roll having a plurality of pins is disposed to face a anvil roll, pressing the plurality of pins from a surface sheet side (that is, a surface sheet nonwoven fabric side), cutting the surface sheet nonwoven fabric and the sheet-like member for diffusion sheet, and compressing the absorber 4 in a thickness direction, thereby forming a plurality of recesses 6 in the laminate;

(6) a 3 rd laminating step of bonding the laminate after the recess forming step to the sheet member for back sheet with a hot-melt adhesive; and

(7) and a bonded portion forming step of disposing a plurality of bonded portions AD on the surface of the laminate obtained in the 3 rd lamination step on the back sheet member side.

In the above-described manufacturing method, the steps other than the recess forming step are selected depending on the type, structure, and the like of the absorbent article, and the order of the steps can be changed.

The material used in the above-described production method (for example, nonwoven fabric for front sheet, sheet-like member for diffusion sheet, absorber, sheet-like member for back sheet, etc.) is not particularly limited, and various materials can be produced by additional other steps or commercially available materials can be used. For example, in the method for manufacturing the sanitary napkin 1, the absorbent body 4 is manufactured by a pulp crushing step.

In the above-described method for manufacturing the sanitary napkin 1, the pins 100 having a specific structure as shown in fig. 7 (a) can be used as the plurality of pins of the processing roll used in the recess forming step. As shown in fig. 7 (a), the pin 100 has a specific structure having: a tip 110 having a recess 105 on a tip surface thereof for forming the projection 65 of the bottom 64 of the recess 6; and a non-distal end portion 120 which is an end portion on the opposite side to the distal end portion 110. In the concave portion forming step, if the plurality of pins 100 having such a specific structure are used, the plurality of concave portions 6 of the sanitary napkin 1 (more specifically, the plurality of concave portions 6 having the convex portions 65 formed on the bottom portion 64) can be easily formed in one step, and therefore the sanitary napkin 1 can be efficiently and easily obtained.

As shown in fig. 7 (a), diameter P1 of tip portion 110 of each of the plurality of pins 100 is formed smaller than diameter P2 of non-tip portion 120. If the plurality of pins 100 used in the concave portion forming step are formed in this manner, the plurality of concave portions 6 of the sanitary napkin 1 can be formed with higher accuracy, and as a result, the sanitary napkin 1 can be obtained with higher accuracy and with ease.

In the present invention, the structure of the plurality of pins used in the recess forming step is not particularly limited as long as the plurality of recesses of the absorbent article can be formed, and for example, a pin 150 having a structure shown in fig. 7 (b) may be used. The pin 150 also has a specific structure having: a tip 160 having a recess 155 on a tip surface thereof for forming the projection 65 of the bottom 64 of the recess 6; and a non-distal end portion 170 which is an end portion on the opposite side to the distal end portion 160, and in the pin 150, although the diameter P1 of the distal end portion 160 is constant as it goes to the non-distal end portion 170 side, since the diameter P1 of the distal end portion 160 is formed smaller than the diameter P2 of the non-distal end portion 170, the same effect as that of the pin 100 shown in fig. 7 (a) described above can be obtained.

In the present invention, a hydrophilic oil may be adhered to the distal end portions of the plurality of pins used in the recess forming step. By using such a pin, the hydrophilic oil agent can be attached to the inner surface of the concave portion simultaneously with the formation of the concave portion, and therefore, the absorbent article having excellent sliding properties of excrement into the concave portion and excellent drawing properties into the absorbent body can be manufactured more efficiently.

In the present invention, the structure of the roll peripheral surface of the anvil roll used in the recess forming step may be any structure capable of forming the above-described recesses, and the roll peripheral surface may have, for example, a smooth structure without recesses and projections, or may have a plurality of recessed portions corresponding to a plurality of pins of the processing roll. Further, if the roll peripheral surface of the anvil roll has a configuration like the latter, there are advantages that the plurality of pins of the processing roll are not easily worn and the absorbent article of the present invention can be manufactured with higher accuracy.

The present invention can be applied to various absorbent articles such as a panty liner, (light) incontinence pad, disposable diaper, and the like, in addition to the sanitary napkin of the above-described embodiment. The absorbent article of the present invention is not limited to the above-described embodiments, and the like, and can be appropriately combined, substituted, modified, and the like without departing from the object and spirit of the present invention. In the present specification, the numbers "1 st", "2 nd", etc. are used to distinguish the items to which the numbers are added, and do not mean the order, priority, importance, etc. of the items.

Description of the reference numerals

1. A sanitary napkin; 2. a surface sheet; 3. a back sheet; 4. an absorbent body; 5. a diffusion sheet; 6. a recess; 61. an opening part; 62. an absorber side concave portion; 63. a peripheral wall portion; 64. a bottom; 64C, bottom center; 64S, the periphery of the bottom; 65. a convex portion; 65T, top; 66. a diffusion sheet side opening; 67. a compressed matter of the surface sheet 2; 68. a compressed product of the diffusion sheet 5; 7. a void portion; 8. a recess on the non-skin-facing surface side; 9. a side panel; 11 to 14, a compression section.