CN114040738B

CN114040738B - Absorbent article

Info

Publication number: CN114040738B
Application number: CN202080046068.7A
Authority: CN
Inventors: 山本成海; 林俊久; 内田祥平; 渡子直纪
Original assignee: Unicharm Corp
Current assignee: Unicharm Corp
Priority date: 2019-06-28
Filing date: 2020-06-24
Publication date: 2023-04-21
Anticipated expiration: 2040-06-24
Also published as: TW202103665A; TWI826699B; KR20220030220A; KR102478357B1; CN114040738A; JP7129382B2; WO2020262415A1; JP2019162526A

Abstract

An absorbent article which suppresses gel blocking and is easily and continuously absorbent of body fluids is provided. The absorbent article (1) has a liquid-permeable top sheet (10), a liquid-impermeable back sheet (20), and an absorber (30) which is disposed between the top sheet and the back sheet and has at least hydrophilic fibers and a superabsorbent polymer. The absorber (30) has: an upper layer absorber (35) having at least hydrophilic fibers; and a lower layer absorber (36) which is arranged on the non-skin-facing surface side of the upper layer absorber. The lower layer absorber has an extension region (R10) extending in the longitudinal direction and the width direction relative to the upper layer absorber. The weight per unit area of the superabsorbent polymer (32) exposed at the skin-facing surface of the upper layer absorber is smaller than the weight per unit area of the superabsorbent polymer (32) exposed at the skin-facing surface of the extension region.

Description

Absorbent article

Technical Field

The present invention relates to an absorbent article to be used by attaching a sanitary pad, a light incontinence pad, or the like to underwear.

Background

Conventionally, an absorbent article attached to underwear and absorbing body fluids such as leucorrhea, sweat, and urine has been used. The absorbent article of patent document 1 has a front sheet, a back sheet, and an absorbent core having a superabsorbent polymer and disposed between the front sheet and the back sheet. The absorbent core of patent document 1 is mainly composed of a superabsorbent polymer, and the superabsorbent polymer is disposed over the entire area of the plane of the absorbent core.

Prior art literature

Patent literature

Patent document 1: japanese patent application laid-open No. 2012-105962

Disclosure of Invention

The absorbent core of patent document 1 is composed mainly of a superabsorbent polymer, and is excellent in retention of body fluid. However, since the superabsorbent polymer is disposed over the entire area of the plane of the absorbent core, the superabsorbent polymer gels upon absorption of body fluid, and gel blocking is likely to occur. If gel blocking occurs, the following may occur: it is difficult to continuously absorb body fluid, leakage occurs, and wearing feeling is deteriorated due to body fluid remaining on the surface.

Thus, an absorbent article that suppresses gel blocking and is easily and continuously absorbent of body fluids is desired.

An absorbent article according to one embodiment includes a front surface sheet having a liquid permeability, a back surface sheet having no liquid permeability, and an absorber disposed between the front surface sheet and the back surface sheet and having at least hydrophilic fibers and a superabsorbent polymer. The absorber has: an upper layer absorber having at least the hydrophilic fibers; and a lower layer absorber disposed on the non-skin-facing surface side of the upper layer absorber. The lower layer absorber has an extension area extending in the longitudinal direction and the width direction with respect to the upper layer absorber. The weight per unit area of the superabsorbent polymer exposed at the skin-facing surface of the upper layer absorbent is smaller than the weight per unit area of the superabsorbent polymer exposed at the skin-facing surface of the extended region.

Drawings

Fig. 1 is a plan view of an absorbent article according to an embodiment, as seen from the skin-facing surface side.

Fig. 2 is a plan view of the absorbent article according to the embodiment, as seen from the non-skin-facing surface side.

Fig. 3 isbase:Sub>A schematic cross-sectional view of the absorbent article shown in fig. 1, taken along sectionbase:Sub>A-base:Sub>A.

Fig. 4 is a schematic cross-sectional view of the absorbent article shown in fig. 1, taken along section B-B.

Fig. 5 is a plan view showing a joint portion between the upper layer absorber and the lower layer absorber.

Detailed Description

(1) Summary of the embodiments

At least the following matters are clarified from the description of the present specification and the drawings.

An absorbent article according to one embodiment includes a front surface sheet having a liquid permeability, a back surface sheet having no liquid permeability, and an absorber disposed between the front surface sheet and the back surface sheet and having at least hydrophilic fibers and a superabsorbent polymer. The absorber has: an upper layer absorber having at least the hydrophilic fibers; and a lower layer absorber disposed on the non-skin-facing surface side of the upper layer absorber. The lower layer absorber has an extension area extending in the longitudinal direction and the width direction with respect to the upper layer absorber. The weight per unit area of the superabsorbent polymer exposed at the skin-facing surface of the upper layer absorbent is smaller than the weight per unit area of the superabsorbent polymer exposed at the skin-facing surface of the extended region. According to this aspect, the upper layer absorber has hydrophilic fibers, and body fluid can be rapidly introduced using the hydrophilic fibers. The body fluid introduced from the upper layer absorber diffuses in the upper layer absorber and is guided toward the lower layer absorber. In this case, since the weight per unit area of the superabsorbent polymer exposed on the skin-facing surface of the upper layer absorber is relatively small, gel blocking at the skin-facing surface of the upper layer absorber can be suppressed, and body fluid can be continuously introduced into the upper layer absorber. In addition, the weight per unit area of the superabsorbent polymer in the extension region of the lower layer absorber is relatively large, and the superabsorbent polymer in the extension region retains the body fluid exuded laterally from the upper layer absorber, thereby suppressing side leakage. The extended region is offset outside the center of the absorbent article from which body fluid is discharged. Therefore, even if gel blocking occurs due to the superabsorbent polymer in the protruding region, body fluid can be continuously held.

According to a preferred embodiment, the upper layer absorber may be an airlaid nonwoven fabric comprising the hydrophilic fibers and the superabsorbent polymer. The air-laid nonwoven fabric has a higher liquid introduction property and a higher release property of the liquid introduced. Therefore, the body fluid discharged onto the upper layer absorber can be promptly introduced, and the body fluid can be promptly guided to the lower layer absorber. Further, the air-laid nonwoven fabric has high diffusibility in the plane direction, and therefore, body fluid introduced into the upper layer absorber can be diffused over a wide range. This makes it possible to hold the body fluid over a large area of the upper layer absorber, and also to easily guide the body fluid to the protruding region of the lower layer absorber. This can suppress gel blocking due to local absorption of body fluid by the upper layer absorber.

In a preferred embodiment, in the upper layer absorber, the hydrophilic fibers are disposed at least on the surface of the lower layer absorber, and the superabsorbent polymer is disposed at least on the skin-facing surface side of the hydrophilic fibers disposed on the surface of the lower layer absorber. According to this aspect, the body fluid which is not completely absorbed in the superabsorbent polymer of the upper layer absorbent body can be introduced by the hydrophilic fiber located on the non-skin-facing side of the superabsorbent polymer. By introducing the body fluid into the upper layer absorber toward the non-skin-facing surface side, the body fluid can be smoothly guided toward the lower layer absorber.

According to a preferred embodiment, the absorber may have heat-fusible fibers, and the heat-fusible fibers may be disposed only in the lower absorber out of the upper absorber and the lower absorber. The heat-fusible fibers are heated during the manufacturing process, thereby forming heat-fused portions. By forming the heat-welded portion in the lower layer absorber, the bonding force between the fibers becomes strong, and the lower layer absorber is less likely to twist. As a result, the absorbent article as a whole is less likely to twist, and can be properly disposed continuously opposite to the body, thereby suppressing leakage and suppressing discomfort. Further, the heat-fusible fibers are not disposed in the upper layer absorber, and therefore, the heat-fusible portions are not formed in the upper layer absorber. The swelling of the super absorbent polymer is not hindered by the strong bonding force between the fibers, and the super absorbent polymer is easily swelled, so that the absorption performance can be maintained.

According to a preferred embodiment, the extension region includes a 1 st region disposed on the upper layer absorber side and a 2 nd region disposed on the outer edge side of the absorbent article, and the weight per unit area of the superabsorbent polymer exposed on the skin facing surface of the 1 st region is greater than the weight per unit area of the superabsorbent polymer exposed on the skin facing surface of the 2 nd region. According to this aspect, since the superabsorbent polymer in the 1 st region has a large weight per unit area, the body fluid can be further retained in the 1 st region located inside the absorbent article in a plan view. The body fluid is less likely to reach the outer edge of the absorbent article, and side leakage can be suppressed.

According to a preferred embodiment, the absorbent assembly may further include an absorbent joint portion provided with an adhesive material for joining the upper layer absorbent body and the lower layer absorbent body, the absorbent joint portion extending in one of the longitudinal direction and the width direction and being provided in plurality at intervals in the other of the longitudinal direction and the width direction. The absorbent joint provided with the adhesive is not easily permeable to body fluid, and the non-absorbent joint not provided with the adhesive is easily permeable to body fluid. According to this aspect, the body fluid absorbed by the upper layer absorber can be diffused in one direction at the non-absorbent joined portion which is the interval between the absorbent joined portions, and the body fluid can be absorbed in a large area. The non-absorbent joining portion can diffuse body fluid, and the absorbent joining portions disposed on both sides of the non-absorbent joining portion can suppress diffusion in the other direction. The liquid accumulation at the separation portion of the upper layer absorber and the lower layer absorber due to excessive diffusion of the body fluid between the upper layer absorber and the lower layer absorber can be suppressed, and the body fluid can be continuously introduced to the lower layer absorber side.

According to a preferred aspect, the absorbent article may be folded about a pair of folding lines extending in the width direction as a base point, the upper layer absorber may have an outer region disposed at a position outside the folding lines in the longitudinal direction, and the absorbent joint may be provided in a region not overlapping the outer region. The outer region of the upper layer absorber is not joined to the lower layer absorber, and is easily moved during folding in the manufacturing process and unfolding in the wearing process. As the outer region moves, the superabsorbent polymer in the upper layer absorber becomes easier to diffuse, and body fluid can be retained in a larger area of the absorber.

According to a preferred embodiment, the absorbent joint may be provided in a region not overlapping the pair of folding lines. If the absorbent joint and the fold line overlap, a more severe crease is formed, and the rigidity of the upper layer absorbent body in the region overlapping the fold line becomes high. However, since the absorbent joined portion and the fold line do not overlap, it is possible to suppress a local increase in the rigidity of the upper layer absorbent body. The super absorbent polymer is not hindered from swelling by local increase of the rigidity of the upper layer absorber, and the super absorbent polymer is easily swelled, so that the absorption performance can be maintained.

According to a preferred embodiment, the present invention may include: an absorption joint part formed by joining the upper layer absorber and the lower layer absorber by using an adhesive material; and an adhesive portion provided with an adhesive for joining the non-skin-facing surface of the absorbent article to the wearing article, and provided with a non-overlapping portion that does not overlap with both the absorbent joining portion and the adhesive portion in the thickness direction. The non-overlapping portion is not overlapped with the absorbent joined portion and the adhesive portion, and air permeability and dryness can be ensured. By providing the non-overlapping portion, the overall stuffiness of the absorbent article can be reduced, and the wearing sensation can be improved.

(2) Overall outline structure of absorbent article

Hereinafter, an absorbent article according to an embodiment will be described with reference to the drawings. In the description of the drawings below, the same or similar parts are denoted by the same or similar reference numerals. It should be noted, however, that the drawings are schematic drawings, the proportion of each dimension, etc. are different from actual ones. Thus, specific dimensions and the like should be judged with reference to the following description. In addition, the drawings may include portions having different dimensional relationships and ratios from each other.

The absorbent article is a sanitary pad. The absorbent article of the present invention may be an absorbent article to be attached to underwear for use, and may be, for example, a light incontinence pad. Fig. 1 is a plan view of the absorbent article 1 according to the present embodiment, as seen from the skin-facing surface side. Fig. 2 is a plan view of the absorbent article shown in fig. 1, as seen from the non-skin-facing surface side. Fig. 3 isbase:Sub>A schematic cross-sectional view of the absorbent article shown in fig. 1, taken along sectionbase:Sub>A-base:Sub>A. Fig. 4 is a schematic cross-sectional view of the absorbent article shown in fig. 1, taken along section B-B.

The absorbent article 1 has a longitudinal direction L and a width direction W orthogonal to each other. The longitudinal direction L is defined by the direction extending toward the front and back sides of the body. In other words, the longitudinal direction L is a direction extending in the front-rear direction in the developed absorbent article 1. The absorbent article 1 has a thickness direction T orthogonal to both the longitudinal direction L and the width direction W. The thickness direction T extends toward the skin-facing surface side T1 facing the wearer side and the non-skin-facing surface side T2 on the opposite side to the skin-facing surface side T1.

The absorbent article 1 has at least a front sheet 10, a back sheet 20, and an absorber 30. The surface sheet 10 may be made of a liquid-permeable sheet such as a nonwoven fabric or an apertured plastic film. The front sheet 10 may be formed by stacking a plurality of sheets, or may have a second sheet. For example, the surface sheet 10 may be constituted by a laminate of a cotton sheet including cotton fibers and a sheet including rayon and polyethylene, or the surface sheet 10 may be constituted by a laminate and a second sheet formed of a hot air nonwoven fabric. The surface sheet 10 of the present embodiment is made of a hot air nonwoven fabric. Further, the nonwoven fabric may have a cotton sheet at a position closer to the skin-facing surface side T1 than the hot air nonwoven fabric. The cotton sheet contacts the skin of the wearer, and thus the touch feeling of the skin can be improved.

The back sheet 20 may be constituted of a liquid impermeable sheet such as a plastic film. The back sheet 20 may also have breathability. By the back sheet 20 having breathability, it is easy to discharge moisture out of the absorbent article through the back sheet 20 when absorbing urine or sweat. Therefore, the stuffiness can be reduced and the wearing feeling can be improved. The front sheet 10 and the back sheet 20 reach the outer edge 1E of the absorbent article 1. In the present embodiment, the outer edge is an outer end in the width direction W, the front edge is a front edge, and the rear edge is a rear edge. The outer edge is an edge including an outer edge, a front edge, and an entire outer periphery of the rear edge.

As shown in fig. 2, an adhesive portion 50 for joining the absorbent article 1 to the undergarment is disposed on the non-skin-facing surface of the back sheet 20. The adhesive portion 50 is a portion provided with an adhesive material for joining the absorbent article 1 to the undergarment. The adhesive portion 50 extends in the width direction W and is provided in plurality at intervals in the longitudinal direction L. The adhesive portion 50 may not reach the outer edge joint portion 40 described later. That is, the adhesive portion 50 and the outer edge joining portion 40 may be separated from each other in a plan view. A portion that is not joined to the wearing article (does not overlap the adhesive portion) and where the sheets are not joined to each other (does not overlap the outer edge joining portion 40) is provided between the adhesive portion 50 and the outer edge joining portion 40. The thickness of the portion between the bonded portion 50 and the outer edge joining portion 40 tends to become thicker when the superabsorbent polymer 32 expands. The swelling of the super absorbent polymer is not hindered, and the super absorbent polymer is easily swelled, and the absorption performance can be maintained.

The outer edge joint 40 may be grasped by a user when wearing the absorbent article 1. The adhesive portion 50 does not reach the outer edge joining portion 40, and therefore, even if the outer edge joining portion 40 is gripped during wearing, the adhesive portion 50 does not come into contact with the adhesive portion, and the adhesive portion is easily attached to and detached from the wearing article. Further, when worn, the outer edge in the width direction of the absorbent article 1 is disposed in the vicinity of the seam of the crotch portion of the wearing article, and is likely to be deformed by the action of the wearer. The adhesive portion 50 does not reach the outer edge joining portion 40, so that the side edge of the absorbent article does not directly follow the action of wearing the article, and deformation of the absorbent article can be suppressed. The adhesive portion 50 may be covered with a wrapping sheet, not shown, before the absorbent article is used. In the modification, the adhesive portion 50 may extend in the longitudinal direction L and may be provided in plural at intervals in the width direction W, or may reach the outer edge joining portion 40.

The absorber 30 is disposed between the front sheet 10 and the back sheet 20. The absorbent body 30 has at least hydrophilic fibers 31 and a superabsorbent polymer (SAP) 32. The absorbent article 1 of the present embodiment is used for a long period of time as a sanitary pad. Body fluids resulting from light incontinence can be absorbed by the fibers, such as white bands, sweat, etc., and also by the superabsorbent polymer 32. The absorber 30 will be described in detail later.

The absorbent article 1 can be folded about a pair of folding lines FL extending in the width direction W as a base point before use. The pair of folding lines FL has a 1 st folding line FL and a 2 nd folding line FL2 arranged at a distance from the 1 st folding line FL1 in the longitudinal direction L.

At least the outer edge joining portion 40 formed by joining the front sheet 10 and the back sheet 20 may be provided along the outer edge 1E of the absorbent article 1. At least the front sheet 10 and the back sheet 20 may be joined to each other at the outer edge joining portion 40, or the absorber 30 may be joined to each other. The outer edge joining portion 40 may reach the outer edge 1E of the absorbent article 1. The outer edge joint 40 may be formed by any one of thermal welding, ultrasonic welding, and embossing. The outer edge joining portion 40 of the present embodiment is formed by joining the front sheet 10, the back sheet 20, and the lower absorbent layer 36 described later by embossing. The outer edge joint 40 formed by embossing is provided on the outer edge 1E of the absorbent article 1, so that even if body fluid reaches the outer edge of the absorbent article 1, the body fluid can be held in the outer edge joint 40 having a high density, and side leakage can be suppressed. In addition, when the outer edge of the outer edge joining portion 40 coincides with the outer edge of the absorbent article 1, a region (region where the sheets and the lower absorbent body are not joined) on the inner side of the outer edge joining portion 40 can be ensured to be large, and therefore, the swelling of the superabsorbent polymer 32 can be suppressed from being inhibited. The outer edge joint portion 40 is shown in fig. 1 and 2, and is omitted in the cross-sectional views of fig. 3 and 4 for convenience of illustration.

Next, the absorber 30 will be described in detail. The absorber 30 includes an upper layer absorber 35 and a lower layer absorber 36 disposed on the non-skin-facing surface side T2 of the upper layer absorber 35. The area of the lower layer absorber 36 is larger than the area of the upper layer absorber 35. The lower layer absorber 36 has an extension region R10 extending with respect to the upper layer absorber 35 in plan view. The extension region R10 is a region marked with oblique lines in fig. 5. The lower layer absorber 36 is disposed on the entire absorbent article 1, and the outer edge of the lower layer absorber 36 coincides with the outer edge of the absorbent article. The upper layer absorber 35 is rectangular in plan view, and spans the center in the width direction W and the center in the longitudinal direction L of the absorbent article 1. The outer edge of the upper layer absorber 35 is located further inward in the width direction W than the outer edge of the absorbent article 1. The outer edge of the upper layer absorber 35 is located inside the outer edge of the absorbent article 1 in the longitudinal direction L. Thus, the extension region R10 is provided at a position outside the upper layer absorber 35 in the longitudinal direction L and a position outside the upper layer absorber 35 in the width direction W, respectively. The extension region R10 is a region between the outer edge of the upper layer absorber 35 and the outer edge 1E of the absorbent article.

The extension region R10 may have a 1 st region R11 disposed on the upper layer absorber 35 side and a 2 nd region R12 disposed on the outer edge side of the absorbent article. The 1 st region R11 is a region disposed on the upper layer absorber 35 side, of the regions bisecting the extension region R10 in the longitudinal direction L or the width direction W. In fig. 5, the boundary between the 1 st region R11 and the 2 nd region R12 is indicated by a single-dot chain line. The boundary between the 1 st region R11 and the 2 nd region R12 of the present embodiment is a line connecting the outer edge of the upper layer absorber 35 and the intermediate point of the outer edge of the absorbent article 1.

The upper layer absorber 35 has at least hydrophilic fibers 31. The weight per unit area of the superabsorbent polymer 32 exposed at the skin-facing surface of the upper layer absorber 35 is smaller than the weight per unit area of the superabsorbent polymer 32 exposed at the skin-facing surface of the extension region R10 of the lower layer absorber 36. The skin-facing surface of the upper layer absorber 35 and the skin-facing surface of the lower layer absorber 36 are the surfaces of the respective absorbers on the skin-facing surface side T1, and are the surfaces facing the topsheet. The superabsorbent polymer 32 exposed on the skin-facing surface of the extension region R10 of the lower absorbent member 36 may be disposed more than the superabsorbent polymer 32 exposed on the skin-facing surface of the upper absorbent member 35, or the superabsorbent polymer 32 exposed on the skin-facing surface of the upper absorbent member 35 may be absent. The superabsorbent polymer 32 may not be disposed in the upper layer absorber 35 and the lower layer absorber 36, and the superabsorbent polymer 32 may be disposed on the skin-facing surface of the upper layer absorber 35 and the skin-facing surface of the lower layer absorber 36. In the present embodiment, the superabsorbent polymer 32 is disposed in the upper layer absorber 35, and a part of the superabsorbent polymer 32 is exposed on the skin facing surface of the upper layer absorber 35. The superabsorbent polymer 32 is not disposed in the lower absorbent layer 36, and the superabsorbent polymer 32 leaking from the upper absorbent layer 35 is exposed in the extension region R10 of the lower absorbent layer 36. In the case where the lower absorbent member 36 extends to the outer edge 30 of the absorbent article, it is preferable that the superabsorbent polymer 32 is not disposed on the side edge portion of the absorbent member in order to prevent the superabsorbent polymer 32 from leaking out from the outer edge 1E of the absorbent article 1, and more preferable that the superabsorbent polymer 32 is not disposed in the lower absorbent member 36. In the case where the superabsorbent polymer 32 is not disposed at the outer edge portion of the absorbent body 30 (the superabsorbent polymer 32 is disposed only at the central portion of the absorbent body), the superabsorbent polymer 32 may be disposed in the lower absorbent layer 36 in order to ensure the water retention capacity of the entire absorbent article. In the present embodiment, the mass of the super absorbent polymer 32 of the lower absorbent body 36 may be lower than the mass of the super absorbent polymer 32 of the upper absorbent body 35.

In comparison of the weight per unit area of the superabsorbent polymer 32, colored water was dropped, and the difference in color was visually confirmed in a state where the superabsorbent polymer 32 of the upper layer absorber 35 and the superabsorbent polymer 32 of the extension region R10 absorbed water. The region where the color per unit area is thicker or the region where the area where the color change per unit area is larger is set as the region where the weight per unit area of the superabsorbent polymer 32 is larger. As another method for comparing the weight per unit area of the superabsorbent polymer 32, the number of superabsorbent polymers 32 that swell by absorbing colored water can be measured by immersing in colored water for about 30 minutes, and the weight per unit area of the superabsorbent polymer 32 can be compared. In addition, the weight per unit area of the superabsorbent polymer 32 exposed on the skin-facing surface of the upper layer absorber 35 does not include the weight per unit area of the superabsorbent polymer 32 of the entire superabsorbent polymer 32 of the upper layer absorber 35, but does not include the weight per unit area of the superabsorbent polymer 32 not exposed on the skin-facing surface of the upper layer absorber 35 but only exposed on the skin-facing surface of the upper layer absorber 35. Similarly, the weight per unit area of the superabsorbent polymer 32 exposed at the skin-facing surface of the extension region R10 of the lower absorbent body 36 is the weight per unit area of the superabsorbent polymer 32 exposed only at the skin-facing surface of the lower absorbent body 36 excluding the superabsorbent polymer 32 not exposed at the skin-facing surface of the lower absorbent body 36.

According to this structure, the hydrophilic fibers 31 of the upper layer absorber 35 can be used to rapidly introduce body fluid. The body fluid introduced by the upper layer absorber 35 diffuses in the upper layer absorber 35 and is guided to the lower layer absorber 36. At this time, since the weight per unit area of the superabsorbent polymer 32 exposed on the skin-facing surface of the upper layer absorber 35 is relatively small, gel blocking at the skin-facing surface of the upper layer absorber 35 can be suppressed, and body fluid can be continuously introduced into the upper layer absorber 35. If the weight per unit area of the superabsorbent polymer 32 exposed on the skin-facing surface of the upper layer absorber 35 is relatively large, there is a risk that transfer of body fluid from the skin-facing surface of the upper layer absorber 35 to the non-skin-facing side is hindered. However, since the weight per unit area of the superabsorbent polymer 32 exposed on the skin-facing surface of the upper layer absorber 35 is relatively small, the body fluid can be continuously introduced into the upper layer absorber 35, and the uncomfortable feeling and foreign body sensation caused by the body fluid remaining on the upper layer absorber 35 can be suppressed. In addition, the weight per unit area of the superabsorbent polymer 32 in the extension region R10 of the lower absorbent layer 36 is relatively large, and the superabsorbent polymer 32 in the extension region R10 retains the body fluid exuded laterally from the upper absorbent layer 35, thereby suppressing side leakage. The extension region R10 is offset to the outside of the center of the absorbent article 1 from which body fluid is discharged. Therefore, even if gel blocking occurs due to the superabsorbent polymer 32 of the extension region R10, body fluid can be continuously held.

The weight per unit area of the superabsorbent polymer 32 exposed at the skin-facing surface of the 1 st region R11 of the extension region R10 may be larger than the weight per unit area of the superabsorbent polymer 32 exposed at the skin-facing surface of the 2 nd region R12. Since the superabsorbent polymer 32 in the 1 st region R11 has a relatively large weight per unit area, the body fluid can be further retained by the 1 st region R11 on the inner side of the absorbent article 1 in a plan view. The body fluid is less likely to reach the outer edge 1E of the absorbent article 1, and side leakage can be suppressed. The 2 nd region R12 is in contact with a region away from the excretory part where sweat is likely to be generated. Sweat which is less discharged than excreted water can be reliably absorbed by the 2 nd region R12. Further, since the superabsorbent polymer 32 in the 2 nd region R12 has a low weight per unit area, discomfort to the skin due to irregularities caused when the superabsorbent polymer 32 swells can be reduced.

The upper layer absorber 35 may be an airlaid nonwoven fabric comprising hydrophilic fibers 31 and superabsorbent polymer 32. The air-laid nonwoven fabric has a higher liquid introduction property and a higher release property of the liquid introduced. Therefore, the body fluid discharged onto the upper layer absorber 35 can be promptly introduced, and the body fluid can be promptly guided toward the lower layer absorber 36. Further, since the air-laid nonwoven fabric has high diffusibility in the plane direction, the body fluid introduced into the upper layer absorber 35 can be diffused over a wide range. This makes it possible to hold the body fluid over a large area of the upper layer absorber 35 and also to easily guide the body fluid toward the extension region R10 of the lower layer absorber 36. This can suppress gel blocking of the upper layer absorber 35 due to absorption of body fluid.

The outer edge of the lower absorbent 36 may be aligned with the outer edge of the absorbent article 1. The area of the lower absorbent 36 is set large, and the absorption capacity can be ensured. In addition, the superabsorbent polymer 32 exposed in the extension region R10 retains the body fluid, and it is possible to suppress the body fluid from reaching the outer edge 1E of the absorbent article 1. That is, the absorption capacity of the lower absorbent member 36 can be ensured, and the side leakage from the outer edge 1E of the absorbent article can be suppressed.

In the upper layer absorber 35, the hydrophilic fibers 31 are disposed at least on the surface of the lower layer absorber 36 side, and the superabsorbent polymer 32 is disposed at least on the skin-facing surface side T1 of the hydrophilic fibers 31 disposed on the surface of the lower layer absorber 36 side. By the hydrophilic fibers 31 positioned on the non-skin-facing side T2 of the high-absorbency polymer 32, body fluid that has not been completely absorbed by the high-absorbency polymer 32 of the upper absorbent member 35 can be introduced and absorbed. By introducing the body fluid into the upper layer absorber 35 toward the non-skin-facing surface side T2, the body fluid can be smoothly guided to the lower layer absorber 36.

The density of the superabsorbent polymer 32 within the absorbent body 30 may be constant or may be different. As shown in fig. 3, the upper layer absorber 35 has a central region 35RC including the center in the thickness direction of the upper layer absorber 35 and a surface side region 35RS located outside the central region 35RC in the thickness direction. The boundary between the central region 35RC and the surface side region 35RS is a boundary that trisects the upper layer absorber 35 in the thickness direction. The density of the superabsorbent polymer 32 in the central region 35RC may be higher than the density of the superabsorbent polymer 32 in the surface side region 35RS. Because of the relatively high density of the superabsorbent polymer 32 in the central region 35RC, the central region 35RC tends to expand upon absorption of bodily fluids. This ensures the absorption capacity of the body fluid. In addition, the density of the superabsorbent polymer 32 in the surface-side region 35RS is low, and gel blocking is less likely to occur when absorbing body fluid, so that the introduction of body fluid can be maintained. As a method for measuring the density, the absorber may be sectioned into sections along the thickness direction, the sections may be photographed by an electron microscope, and the number of superabsorbent polymers 32 contained in the same area in each region may be measured so that the density increases as the number increases. As another method for measuring the number of superabsorbent polymers 32, the number of superabsorbent polymers 32 that swell by absorbing colored water can be measured by immersing in colored water for about 30 minutes, and the density can be increased as the number increases.

The absorber 30 may have heat-fusible fibers 33. The heat-fusible fibers 33 may be disposed only in the lower absorber 36 out of the upper absorber 35 and the lower absorber 36. That is, the heat-fusible fibers 33 may not be disposed in the upper layer absorber 35. The heat-fusible fibers 33 are heated during the manufacturing process, thereby forming heat-fused portions. By forming the heat-welded portion in the lower absorber 36, the bonding force between the fibers is enhanced, and the lower absorber 36 is less likely to twist. As a result, the absorbent article as a whole is less likely to twist, and can be properly disposed continuously opposite to the body, thereby suppressing leakage and suppressing discomfort. Further, the heat-fusible fibers 33 are not disposed in the upper layer absorber 35, and therefore, no heat-fusible portion is formed in the upper layer absorber 35. The swelling of the superabsorbent polymer 32 is not hindered by the strong bonding force between the fibers, and the superabsorbent polymer 32 is easily swelled, so that the absorbency can be maintained.

The upper layer absorber 35 of the present embodiment is an air-laid nonwoven fabric having hydrophilic fibers 31, a binder (bonding material), a hydrophilic agent, and a superabsorbent polymer 32, and the lower layer absorber 36 is an air-laid nonwoven fabric having a binder (bonding material), a hydrophilic agent, and heat-fusible fibers 33. The air-laid nonwoven fabric of the lower absorbent 36 does not have the superabsorbent polymer 32, and the superabsorbent polymer 32 is disposed on the air-laid nonwoven fabric.

The absorbent article 1 has an absorbent joined portion 70 formed by joining the upper layer absorbent body 35 and the lower layer absorbent body 36. Fig. 5 is a plan view showing the absorption joint 70 of the upper layer absorber 35 and the lower layer absorber 36. The absorbent joint 70 may extend in one of the longitudinal direction L and the width direction W, and may be provided in plurality at intervals in the other of the longitudinal direction L and the width direction W. The absorbent joint 70 of the present embodiment may extend in the width direction W, and a plurality of absorbent joints may be provided at intervals in the longitudinal direction L. In the modification, a plurality of the absorption joining portions 70 may be provided at intervals in the width direction W, extending along the longitudinal direction L. The absorbent joint 70 may extend in the same direction as the adhesive portion 50 and may be disposed at intervals in the same direction as the adhesive portion 50.

The absorbent joint 70 provided with the adhesive is not easily permeable to body fluid, and the non-absorbent joint not provided with the adhesive is easily permeable to body fluid. The non-absorbent joint is a portion other than the absorbent joint 70. According to this embodiment, the body fluid absorbed by the upper layer absorber 35 can be diffused in one direction at the non-absorbent joined portions of the interval between the absorbent joined portions 70, and the body fluid can be absorbed in a large area. The body fluid can be spread in the width direction W by the non-absorbent joining portions, and the spread can be suppressed by the absorbent joining portions 70 disposed on both sides in the longitudinal direction L with respect to the non-absorbent joining portions. The liquid accumulation at the peeled portion of the upper layer absorber 35 and the lower layer absorber 36 due to excessive diffusion of the body fluid between the upper layer absorber 35 and the lower layer absorber 36 can be suppressed, and the body fluid can be continuously introduced to the lower layer absorber 36 side.

The absorbent joint 70 may be provided in a region of the absorbent article 1 that does not overlap the pair of folding lines FL. If the absorbent joint 70 overlaps the folding line FL, a more severe crease is formed, and the rigidity of the region of the upper layer absorbent body 35 overlapping the folding line FL becomes high. However, since the absorbent joint 70 does not overlap the fold line FL, it is possible to suppress a local increase in the rigidity of the upper layer absorbent 35. The super absorbent polymer 32 is not hindered from swelling by the local increase in rigidity of the upper absorbent 35, and the super absorbent polymer 32 is easily swelled, so that the absorption performance can be maintained.

The upper layer absorber 35 may overlap at least one of the pair of folding lines FL. As shown in fig. 5, the upper layer absorbent 35 has an outer region R15 disposed outside the folding line FL in the longitudinal direction L. In the present embodiment, one end in the longitudinal direction L of the upper layer absorber 35 is located outside the 1 st folding line FL1 in the longitudinal direction L, and the other end in the longitudinal direction L of the upper layer absorber 35 coincides with the 2 nd folding line FL2. Thus, the outer region R15 of the upper layer absorber 35 is provided outside the 1 st folding line FL1 in the longitudinal direction L. The outer region R15 is not joined to the lower absorbent layer 36, and is easily moved during folding in the manufacturing process and unfolding in the wearing process. As the outer region R15 moves, the superabsorbent polymer 32 in the upper layer absorber 35 becomes easy to diffuse, and body fluid can be retained in a wide range of the absorber.

As shown in fig. 4, the absorbent article 1 is provided with a non-overlapping portion R20 which does not overlap with both the absorbent joined portion 70 and the adhesive portion 50 in the thickness direction T. The non-overlapping portion R20 does not overlap with the absorbent joint 70 and the adhesive portion 50, and air permeability and dryness can be ensured. The stuffiness of the whole absorbent article can be reduced, and the wearing feeling can be improved.

The present invention has been described in detail using the above embodiments, but it is obvious to those skilled in the art that the present invention is not limited to the embodiments described in the present specification. The present invention can be implemented as modifications and variations without departing from the spirit and scope of the present invention as defined in the appended claims. Accordingly, the description of the present invention is intended to be illustrative, and not restrictive.

The entire contents of Japanese patent application No. 2019-121743 filed on 28 of 6 th 2019 are incorporated herein by reference.

Industrial applicability

According to the present invention, an absorbent article that suppresses gel blocking and is easy to continuously absorb body fluid can be provided.

Description of the reference numerals

1. An absorbent article; 1E, the outer edge; 10. a surface sheet; 20. a back sheet; 30. an absorber; 31. hydrophilic fibers; 32. a superabsorbent polymer; 33. a heat-fusible fiber; 35. an upper layer absorber; 36. a lower layer absorber; 50. an adhesive portion; 70. an absorbent joint; l, length direction; t, thickness direction; t1, the skin opposite side; t2, non-skin facing side; w, width direction.

Claims

1. An absorbent article comprising a liquid-permeable front sheet, a liquid-impermeable back sheet, and an absorber which is disposed between the front sheet and the back sheet and has at least hydrophilic fibers and a superabsorbent polymer,

the absorber has: an upper layer absorber having at least the hydrophilic fibers; and a lower layer absorber disposed on the non-skin-facing surface side of the upper layer absorber,

the lower layer absorber has an extension area extending in the length direction and the width direction with respect to the upper layer absorber,

the weight per unit area of the superabsorbent polymer exposed at the skin-facing surface of the upper layer absorbent is smaller than the weight per unit area of the superabsorbent polymer exposed at the skin-facing surface of the extended region,

the absorbent article has an absorption joint part formed by joining the upper layer absorber and the lower layer absorber by using an adhesive material,

the absorbent article is folded with a pair of folding lines extending in the width direction as a base point,

the upper layer absorber has an outer region disposed at a position outside the folding line in the longitudinal direction,

the absorption joint is provided in a region that does not overlap with the outer region.

2. The absorbent article of claim 1, wherein,

the absorbent joint is provided in a region that does not overlap the pair of fold lines.

3. An absorbent article comprising a liquid-permeable front sheet, a liquid-impermeable back sheet, and an absorber which is disposed between the front sheet and the back sheet and has at least hydrophilic fibers and a superabsorbent polymer,

the absorbent article comprises: an absorption joint part formed by joining the upper layer absorber and the lower layer absorber by using an adhesive material; and an adhesive part provided with an adhesive for bonding the non-skin-facing surface of the absorbent article to the wearing article,

the absorbent article is provided with a non-overlapping portion that does not overlap with both the absorbent joint portion and the adhesive portion in the thickness direction.

4. An absorbent article comprising a liquid-permeable front sheet, a liquid-impermeable back sheet, and an absorber which is disposed between the front sheet and the back sheet and has at least hydrophilic fibers and a superabsorbent polymer,

the super absorbent polymer is disposed not in the lower layer absorber but in the upper layer absorber,

the superabsorbent polymer leaking from the upper layer absorber is disposed on the skin-facing surface of the protruding region.

5. An absorbent article comprising a liquid-permeable front sheet, a liquid-impermeable back sheet, and an absorber which is disposed between the front sheet and the back sheet and has at least hydrophilic fibers and a superabsorbent polymer,

the extension region has a 1 st region disposed on the upper layer absorber side and a 2 nd region disposed on the outer edge side of the absorbent article,

the weight per unit area of the superabsorbent polymer exposed at the skin-facing surface of the 1 st region is greater than the weight per unit area of the superabsorbent polymer exposed at the skin-facing surface of the 2 nd region.

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

the absorber has heat-fusible fibers,

the heat-fusible fibers are disposed only in the lower layer absorber out of the upper layer absorber and the lower layer absorber.

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

the upper layer absorbent is an airlaid nonwoven comprising the hydrophilic fibers and the superabsorbent polymer.

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

in the upper layer absorber, the hydrophilic fibers are disposed at least on the surface of the lower layer absorber, and the superabsorbent polymer is disposed at least on the skin-facing surface side of the hydrophilic fibers disposed on the surface of the lower layer absorber.

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

the absorption joint portion extends along one of the longitudinal direction and the width direction, and is provided in plurality at intervals in the other of the longitudinal direction and the width direction.